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Yao J, Chen SRW. RyR2-dependent modulation of neuronal hyperactivity: A potential therapeutic target for treating Alzheimer's disease. J Physiol 2024; 602:1509-1518. [PMID: 36866974 DOI: 10.1113/jp283824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 02/27/2023] [Indexed: 03/04/2023] Open
Abstract
Increasing evidence suggests that simply reducing β-amyloid (Aβ) plaques may not significantly affect the progression of Alzheimer's disease (AD). There is also increasing evidence indicating that AD progression is driven by a vicious cycle of soluble Aβ-induced neuronal hyperactivity. In support of this, it has recently been shown that genetically and pharmacologically limiting ryanodine receptor 2 (RyR2) open time prevents neuronal hyperactivity, memory impairment, dendritic spine loss and neuronal cell death in AD mouse models. By contrast, increased RyR2 open probability (Po) exacerbates the onset of familial AD-associated neuronal dysfunction and induces AD-like defects in the absence of AD-causing gene mutations. Thus, RyR2-dependent modulation of neuronal hyperactivity represents a promising new target for combating AD.
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Affiliation(s)
- Jinjing Yao
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - S R Wayne Chen
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
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2
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Shahid A, Wang J, Andresen BT, Chen SRW, Huang Y. Editorial: Repurposing β-blockers for non-cardiovascular diseases. Front Pharmacol 2024; 15:1372317. [PMID: 38405668 PMCID: PMC10884952 DOI: 10.3389/fphar.2024.1372317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 01/23/2024] [Indexed: 02/27/2024] Open
Affiliation(s)
- Ayaz Shahid
- Department of Biotechnology and Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA, United States
| | - Jeffrey Wang
- Department of Biotechnology and Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA, United States
| | - Bradley T. Andresen
- Department of Biotechnology and Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA, United States
| | - S. R. Wayne Chen
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB, Canada
| | - Ying Huang
- Department of Biotechnology and Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA, United States
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Tian S, Zhong X, Wang H, Wei J, Guo W, Wang R, Paul Estillore J, Napolitano C, Duff HH, Ilhan E, Knight LM, Lloyd MS, Roberts JD, Priori SG, Chen SRW. RyR2 C-terminal truncating variants identified in patients with arrhythmic phenotypes exert a dominant negative effect through formation of wildtype-truncation heteromers. Biochem J 2023; 480:1379-1395. [PMID: 37492947 DOI: 10.1042/bcj20230254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 07/19/2023] [Accepted: 07/25/2023] [Indexed: 07/27/2023]
Abstract
Gain-of-function missense variants in the cardiac ryanodine receptor (RyR2) are linked to catecholaminergic polymorphic ventricular tachycardia (CPVT), whereas RyR2 loss-of-function missense variants cause Ca2+ release deficiency syndrome (CRDS). Recently, truncating variants in RyR2 have also been associated with ventricular arrhythmias (VAs) and sudden cardiac death. However, there are limited insights into the potential clinical relevance and in vitro functional impact of RyR2 truncating variants. We performed genetic screening of patients presenting with syncope, VAs, or unexplained sudden death and in vitro characterization of the expression and function of RyR2 truncating variants in HEK293 cells. We identified two previously unknown RyR2 truncating variants (Y4591Ter and R4663Ter) and one splice site variant predicted to result in a frameshift and premature termination (N4717 + 15Ter). These 3 new RyR2 truncating variants and a recently reported RyR2 truncating variant, R4790Ter, were generated and functionally characterized in vitro. Immunoprecipitation and immunoblotting analyses showed that all 4 RyR2 truncating variants formed heteromers with the RyR2-wildtype (WT) protein. Each of these C-terminal RyR2 truncations was non-functional and suppressed [3H]ryanodine binding to RyR2-WT and RyR2-WT mediated store overload induced spontaneous Ca2+ release activity in HEK293 cells. The expression of these RyR2 truncating variants in HEK293 cells was markedly reduced compared with that of the full-length RyR2 WT protein. Our data indicate that C-terminal RyR2 truncating variants are non-functional and can exert a dominant negative impact on the function of the RyR2 WT protein through formation of heteromeric WT/truncation complex.
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Affiliation(s)
- Shanshan Tian
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Xiaowei Zhong
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Hui Wang
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Jinhong Wei
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
- School of Medicine, Northwest University, Xi'an 710069, China
| | - Wenting Guo
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Ruiwu Wang
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - John Paul Estillore
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Carlo Napolitano
- European Reference Network 'ERN GUARD-Heart', Amsterdam, Netherlands
- Division of Cardiology and Molecular Cardiology, IRCCS Maugeri Foundation-University of Pavia, 27100 Pavia, Italy
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
| | - Henry H Duff
- Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Erkan Ilhan
- Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Linda M Knight
- Children's Healthcare of Atlanta Cardiology, Atlanta, Georgia, U.S.A
| | - Michael S Lloyd
- Emory University School of Medicine, Atlanta, Georgia, U.S.A
| | - Jason D Roberts
- Population Health Research Institute, McMaster University, and Hamilton Health Sciences, Hamilton, Ontario, Canada
| | - Silvia G Priori
- European Reference Network 'ERN GUARD-Heart', Amsterdam, Netherlands
- Division of Cardiology and Molecular Cardiology, IRCCS Maugeri Foundation-University of Pavia, 27100 Pavia, Italy
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
- Molecular Cardiology Laboratory, Centro de Investigaciones Cardiovasculares Carlos III, 28029 Madrid, Spain
| | - S R Wayne Chen
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
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Ni M, Li Y, Wei J, Song Z, Wang H, Yao J, Chen YX, Belke D, Estillore JP, Wang R, Vallmitjana A, Benitez R, Hove-Madsen L, Feng W, Chen J, Roston TM, Sanatani S, Lehman A, Chen SRW. Increased Ca 2+ Transient Underlies RyR2-Related Left Ventricular Noncompaction. Circ Res 2023; 133:177-192. [PMID: 37325910 DOI: 10.1161/circresaha.123.322504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 06/07/2023] [Indexed: 06/17/2023]
Abstract
BACKGROUND A loss-of-function cardiac ryanodine receptor (RyR2) mutation, I4855M+/-, has recently been linked to a new cardiac disorder termed RyR2 Ca2+ release deficiency syndrome (CRDS) as well as left ventricular noncompaction (LVNC). The mechanism by which RyR2 loss-of-function causes CRDS has been extensively studied, but the mechanism underlying RyR2 loss-of-function-associated LVNC is unknown. Here, we determined the impact of a CRDS-LVNC-associated RyR2-I4855M+/- loss-of-function mutation on cardiac structure and function. METHODS We generated a mouse model expressing the CRDS-LVNC-associated RyR2-I4855M+/- mutation. Histological analysis, echocardiography, ECG recording, and intact heart Ca2+ imaging were performed to characterize the structural and functional consequences of the RyR2-I4855M+/- mutation. RESULTS As in humans, RyR2-I4855M+/- mice displayed LVNC characterized by cardiac hypertrabeculation and noncompaction. RyR2-I4855M+/- mice were highly susceptible to electrical stimulation-induced ventricular arrhythmias but protected from stress-induced ventricular arrhythmias. Unexpectedly, the RyR2-I4855M+/- mutation increased the peak Ca2+ transient but did not alter the L-type Ca2+ current, suggesting an increase in Ca2+-induced Ca2+ release gain. The RyR2-I4855M+/- mutation abolished sarcoplasmic reticulum store overload-induced Ca2+ release or Ca2+ leak, elevated sarcoplasmic reticulum Ca2+ load, prolonged Ca2+ transient decay, and elevated end-diastolic Ca2+ level upon rapid pacing. Immunoblotting revealed increased level of phosphorylated CaMKII (Ca2+-calmodulin dependent protein kinases II) but unchanged levels of CaMKII, calcineurin, and other Ca2+ handling proteins in the RyR2-I4855M+/- mutant compared with wild type. CONCLUSIONS The RyR2-I4855M+/- mutant mice represent the first RyR2-associated LVNC animal model that recapitulates the CRDS-LVNC overlapping phenotype in humans. The RyR2-I4855M+/- mutation increases the peak Ca2+ transient by increasing the Ca2+-induced Ca2+ release gain and the end-diastolic Ca2+ level by prolonging Ca2+ transient decay. Our data suggest that the increased peak-systolic and end-diastolic Ca2+ levels may underlie RyR2-associated LVNC.
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Affiliation(s)
- Mingke Ni
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (M.N., Y.L., J.W., Z.S., H.W., J.Y., Y.-X.C., D.B., J.P.E., R.W., S.R.W.C.)
| | - Yanhui Li
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (M.N., Y.L., J.W., Z.S., H.W., J.Y., Y.-X.C., D.B., J.P.E., R.W., S.R.W.C.)
| | - Jinhong Wei
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (M.N., Y.L., J.W., Z.S., H.W., J.Y., Y.-X.C., D.B., J.P.E., R.W., S.R.W.C.)
- School of Medicine, Northwest University, Xi 'an, China (J.W.)
| | - Zhenpeng Song
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (M.N., Y.L., J.W., Z.S., H.W., J.Y., Y.-X.C., D.B., J.P.E., R.W., S.R.W.C.)
| | - Hui Wang
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (M.N., Y.L., J.W., Z.S., H.W., J.Y., Y.-X.C., D.B., J.P.E., R.W., S.R.W.C.)
| | - Jinjing Yao
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (M.N., Y.L., J.W., Z.S., H.W., J.Y., Y.-X.C., D.B., J.P.E., R.W., S.R.W.C.)
| | - Yong-Xiang Chen
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (M.N., Y.L., J.W., Z.S., H.W., J.Y., Y.-X.C., D.B., J.P.E., R.W., S.R.W.C.)
| | - Darrell Belke
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (M.N., Y.L., J.W., Z.S., H.W., J.Y., Y.-X.C., D.B., J.P.E., R.W., S.R.W.C.)
| | - John Paul Estillore
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (M.N., Y.L., J.W., Z.S., H.W., J.Y., Y.-X.C., D.B., J.P.E., R.W., S.R.W.C.)
| | - Ruiwu Wang
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (M.N., Y.L., J.W., Z.S., H.W., J.Y., Y.-X.C., D.B., J.P.E., R.W., S.R.W.C.)
| | - Alexander Vallmitjana
- Department of Automatic Control, Universitat Politècnica de Catalunya, Barcelona, Spain (A.V., R.B.)
| | - Raul Benitez
- Department of Automatic Control, Universitat Politècnica de Catalunya, Barcelona, Spain (A.V., R.B.)
- Institut de Recerca Sant Joan de Déu (IRSJD), Barcelona, Spain (R.B.)
| | - Leif Hove-Madsen
- Biomedical Research Institute Barcelona IIBB-CSIC, IIB Sant Pau and CIBERCV, Hospital de Sant Pau, Barcelona, Spain (L.H.-M.)
| | - Wei Feng
- Department of Medicine, School of Medicine, University of California, San Diego, La Jolla (W.F., J.C.)
| | - Ju Chen
- Department of Medicine, School of Medicine, University of California, San Diego, La Jolla (W.F., J.C.)
| | - Thomas M Roston
- Division of Pediatric Cardiology, Department of Pediatrics (T.M.R., S.S.), University of British Columbia, Vancouver, Canada
| | - Shubhayan Sanatani
- Division of Pediatric Cardiology, Department of Pediatrics (T.M.R., S.S.), University of British Columbia, Vancouver, Canada
| | - Anna Lehman
- Department of Medical Genetics (A.L.), University of British Columbia, Vancouver, Canada
| | - S R Wayne Chen
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (M.N., Y.L., J.W., Z.S., H.W., J.Y., Y.-X.C., D.B., J.P.E., R.W., S.R.W.C.)
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5
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Steinberg C, Roston TM, van der Werf C, Sanatani S, Chen SRW, Wilde AAM, Krahn AD. RYR2-ryanodinopathies: from calcium overload to calcium deficiency. Europace 2023; 25:euad156. [PMID: 37387319 PMCID: PMC10311407 DOI: 10.1093/europace/euad156] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Accepted: 05/02/2023] [Indexed: 07/01/2023] Open
Abstract
The sarcoplasmatic reticulum (SR) cardiac ryanodine receptor/calcium release channel RyR2 is an essential regulator of cardiac excitation-contraction coupling and intracellular calcium homeostasis. Mutations of the RYR2 are the cause of rare, potentially lethal inherited arrhythmia disorders. Catecholaminergic polymorphic ventricular tachycardia (CPVT) was first described more than 20 years ago and is the most common and most extensively studied cardiac ryanodinopathy. Over time, other distinct inherited arrhythmia syndromes have been related to abnormal RyR2 function. In addition to CPVT, there are at least two other distinct RYR2-ryanodinopathies that differ mechanistically and phenotypically from CPVT: RYR2 exon-3 deletion syndrome and the recently identified calcium release deficiency syndrome (CRDS). The pathophysiology of the different cardiac ryanodinopathies is characterized by complex mechanisms resulting in excessive spontaneous SR calcium release or SR calcium release deficiency. While the vast majority of CPVT cases are related to gain-of-function variants of the RyR2 protein, the recently identified CRDS is linked to RyR2 loss-of-function variants. The increasing number of these cardiac 'ryanodinopathies' reflects the complexity of RYR2-related cardiogenetic disorders and represents an ongoing challenge for clinicians. This state-of-the-art review summarizes our contemporary understanding of RYR2-related inherited arrhythmia disorders and provides a systematic and comprehensive description of the distinct cardiac ryanodinopathies discussing clinical aspects and molecular insights. Accurate identification of the underlying type of cardiac ryanodinopathy is essential for the clinical management of affected patients and their families.
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Affiliation(s)
- Christian Steinberg
- Institut universitaire de cardiologie et pneumologie de Québec, Laval University, 2725, Chemin Ste-Foy, Quebec G1V 4G5, Canada
| | - Thomas M Roston
- Centre for Cardiovascular Innovation, Division of Cardiology, St. Paul’s Hospital, University of British Columbia, 211-1033 Davie Street, Vancouver, BC, V6E 1M7, Canada
| | - Christian van der Werf
- Amsterdam UMC, Department of Clinical and Experimental Cardiology, University of Amsterdam, Heart Centre, Amsterdam Cardiovascular Sciences, Amsterdam, the Netherlands
| | - Shubhayan Sanatani
- Division of Cardiology, Department of Pediatrics, BC Children’s Hospital, University of British Columbia, Vancouver, Canada
| | - S R Wayne Chen
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Calgary, Canada
| | - Arthur A M Wilde
- Amsterdam UMC, Department of Clinical and Experimental Cardiology, University of Amsterdam, Heart Centre, Amsterdam Cardiovascular Sciences, Amsterdam, the Netherlands
| | - Andrew D Krahn
- Centre for Cardiovascular Innovation, Division of Cardiology, St. Paul’s Hospital, University of British Columbia, 211-1033 Davie Street, Vancouver, BC, V6E 1M7, Canada
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Yao J, Ni M, Tian S, Sun B, Wang R, Paul Estillore J, Back TG, Wayne Chen SR. A Gain-of-function Mutation in the Gating Domain of ITPR1 Impairs Motor Movement and Increases Thermal and Mechanical Sensitivity. Neuroscience 2023; 522:11-22. [PMID: 37164302 DOI: 10.1016/j.neuroscience.2023.04.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 04/14/2023] [Accepted: 04/30/2023] [Indexed: 05/12/2023]
Abstract
Inositol 1,4,5-trisphosphate receptor type 1 (ITPR1) is an intracellular Ca2+ release channel important for a number of fundamental cellular functions. Consistent with its critical physiological significance, mutations in ITPR1 are associated with disease. Surprisingly, nearly all the disease-associated ITPR1 mutations characterized to date are loss of function. Despite the paucity of ITPR1 gain-of-function (GOF) mutations, enhanced ITPR1 function as a result of dysregulation by ITPR1 interacting proteins is thought to be associated with ataxia, learning and memory impairments, Alzheimer's disease (AD) progression, and chronic pain. However, direct evidence for the role of ITPR1 GOF in disease is lacking. To determine whether GOF in ITPR1 itself has pathological ramifications, we employed a newly developed mouse model expressing an ITPR1 mutation in the gating domain of the channel, D2594K, that markedly increased the channel's sensitivity to activation by IP3. Behavioral studies showed that the ITPR1-D2594K+/- mutant mice displayed motor deficits and reduced muscle strength. However, the ITPR1-D2594K+/- mutation did not significantly alter hippocampal learning and memory and did not change learning and memory impairments when crossed with the 5xFAD AD model mice. On the other hand, ITPR1-D2594K+/- mice exhibited increased sensitivity to thermal and mechanical stimulation compared to WT. Interestingly, R-carvedilol treatment attenuated the enhanced thermal and mechanical nociception in ITPR1-D2594K+/- mice. Thus, the ITPR1-D2594K+/- mutation in the channel's gating domain has a marked impact on motor movements and pain perception, but little effect on hippocampal learning and memory.
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Affiliation(s)
- Jinjing Yao
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada; Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1, Canada
| | - Mingke Ni
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Shanshan Tian
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Bo Sun
- Medical School, Kunming University of Science and Technology, Kunming, China
| | - Ruiwu Wang
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - John Paul Estillore
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Thomas G Back
- Department of Chemistry, University of Calgary, Calgary, AB, Canada, T2N 1N4
| | - S R Wayne Chen
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada; Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1, Canada.
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Tambeaux A, Aguilar-Sánchez Y, Santiago DJ, Mascitti M, DiNovo KM, Mejía-Alvarez R, Fill M, Wayne Chen SR, Ramos-Franco J. Ligand sensitivity of type-1 inositol 1,4,5-trisphosphate receptor is enhanced by the D2594K mutation. Pflugers Arch 2023; 475:569-581. [PMID: 36881190 PMCID: PMC10105685 DOI: 10.1007/s00424-023-02796-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 02/06/2023] [Accepted: 02/12/2023] [Indexed: 03/08/2023]
Abstract
Inositol 1,4,5-trisphosphate receptor (IP3R) and ryanodine receptor (RyR) are homologous cation channels that mediate release of Ca2+ from the endoplasmic/sarcoplasmic reticulum (ER/SR) and thereby are involved in many physiological processes. In previous studies, we determined that when the D2594 residue, located at or near the gate of the IP3R type 1, was replaced by lysine (D2594K), a gain of function was obtained. This mutant phenotype was characterized by increased IP3 sensitivity. We hypothesized the IP3R1-D2594 determines the ligand sensitivity of the channel by electrostatically affecting the stability of the closed and open states. To test this possibility, the relationship between the D2594 site and IP3R1 regulation by IP3, cytosolic, and luminal Ca2+ was determined at the cellular, subcellular, and single-channel levels using fluorescence Ca2+ imaging and single-channel reconstitution. We found that in cells, D2594K mutation enhances the IP3 ligand sensitivity. Single-channel IP3R1 studies revealed that the conductance of IP3R1-WT and -D2594K channels is similar. However, IP3R1-D2594K channels exhibit higher IP3 sensitivity, with substantially greater efficacy. In addition, like its wild type (WT) counterpart, IP3R1-D2594K showed a bell-shape cytosolic Ca2+-dependency, but D2594K had greater activity at each tested cytosolic free Ca2+ concentration. The IP3R1-D2594K also had altered luminal Ca2+ sensitivity. Unlike IP3R1-WT, D2594K channel activity did not decrease at low luminal Ca2+ levels. Taken together, our functional studies indicate that the substitution of a negatively charged residue by a positive one at the channels' pore cytosolic exit affects the channel's gating behavior thereby explaining the enhanced ligand-channel's sensitivity.
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Affiliation(s)
- Allison Tambeaux
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, IL, USA
| | - Yuriana Aguilar-Sánchez
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, IL, USA.,Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX, USA
| | - Demetrio J Santiago
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, IL, USA.,Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
| | | | - Karyn M DiNovo
- Department of Physiology, Midwestern University, Downers Grove, IL, USA
| | | | - Michael Fill
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, IL, USA
| | - S R Wayne Chen
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, IL, USA.,Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada
| | - Josefina Ramos-Franco
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, IL, USA.
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8
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Zhang H, Knight C, Chen SRW, Bezprozvanny I. A Gating Mutation in Ryanodine Receptor Type 2 Rescues Phenotypes of Alzheimer's Disease Mouse Models by Upregulating Neuronal Autophagy. J Neurosci 2023; 43:1441-1454. [PMID: 36627208 PMCID: PMC9987572 DOI: 10.1523/jneurosci.1820-22.2022] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 11/26/2022] [Accepted: 12/19/2022] [Indexed: 01/12/2023] Open
Abstract
It is well established that ryanodine receptors (RyanRs) are overactive in Alzheimer's disease (AD), and it has been suggested that inhibition of RyanR is potentially beneficial for AD treatment. In the present study, we explored a potential connection between basal RyanR activity and autophagy in neurons. Autophagy plays an important role in clearing damaged organelles and long-lived protein aggregates, and autophagy dysregulation occurs in both AD patients and AD animal models. Autophagy is known to be regulated by intracellular calcium (Ca2+) signals, and our results indicated that basal RyanR2 activity in hippocampal neurons inhibited autophagy through activation of calcineurin and the resulting inhibition of the AMPK (AMP-activated protein kinase)-ULK1 (unc-51-like autophagy-activating kinase 1) pathway. Thus, we hypothesized that increased basal RyanR2 activity in AD may lead to the inhibition of neuronal autophagy and accumulation of β-amyloid. To test this hypothesis, we took advantage of the RyanR2-E4872Q knock-in mouse model (EQ) in which basal RyanR2 activity is reduced because of shortened channel open time. We discovered that crossing EQ mice with the APPKI and APPPS1 mouse models of AD (both males and females) rescued amyloid accumulation and LTP impairment in these mice. Our results revealed that reduced basal activity of RyanR2-EQ channels disinhibited the autophagic pathway and led to increased amyloid clearance in these models. These data indicated a potential pathogenic outcome of RyanR2 overactivation in AD and also provided additional targets for therapeutic intervention in AD. Basal activity of ryanodine receptors controls neuronal autophagy and contributes to development of the AD phenotype.SIGNIFICANCE STATEMENT It is well established that neuronal autophagy is impaired in Alzheimer's disease (AD). Our results suggest that supranormal calcium (Ca2+) release from endoplasmic reticulum contributes to the inhibition of autophagy in AD and that reduction in basal activity of type 2 ryanodine receptors disinhibits the neuronal autophagic pathway and leads to increased amyloid clearance in AD models. Our findings directly link neuronal Ca2+ dysregulation with autophagy dysfunction in AD and point to additional targets for therapeutic intervention.
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Affiliation(s)
- Hua Zhang
- Department of Physiology, UT Southwestern Medical Center, Dallas, Texas 75390
| | - Caitlynn Knight
- Department of Physiology, UT Southwestern Medical Center, Dallas, Texas 75390
| | - S R Wayne Chen
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Ilya Bezprozvanny
- Department of Physiology, UT Southwestern Medical Center, Dallas, Texas 75390
- Laboratory of Molecular Neurodegeneration, St. Petersburg State Polytechnical Universty, St. Petersburg 195251, Russian Federation
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Jiménez-Sábado V, Casabella-Ramón S, Llach A, Gich I, Casellas S, Ciruela F, Chen SRW, Guerra JM, Ginel A, Benítez R, Cinca J, Tarifa C, Hove-Madsen L. Beta-blocker treatment of patients with atrial fibrillation attenuates spontaneous calcium release-induced electrical activity. Biomed Pharmacother 2023; 158:114169. [PMID: 36592495 DOI: 10.1016/j.biopha.2022.114169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 12/21/2022] [Accepted: 12/28/2022] [Indexed: 01/01/2023] Open
Abstract
AIMS Atrial fibrillation (AF) has been associated with excessive spontaneous calcium release, linked to cyclic AMP (cAMP)-dependent phosphorylation of calcium regulatory proteins. Because β-blockers are expected to attenuate cAMP-dependent signaling, we aimed to examine whether the treatment of patients with β-blockers affected the incidence of spontaneous calcium release events or transient inward currents (ITI). METHODS The impact of treatment with commonly used β-blockers was analyzed in human atrial myocytes from 371 patients using patch-clamp technique, confocal calcium imaging or immunofluorescent labeling. Data were analyzed using multivariate regression analysis taking into account potentially confounding effects of relevant clinical factors RESULTS: The L-type calcium current (ICa) density was diminished significantly in patients with chronic but not paroxysmal AF and the treatment of patients with β-blockers did not affect ICa density in any group. By contrast, the ITI frequency was elevated in patients with either paroxysmal or chronic AF that did not receive treatment, and β-blocker treatment reduced the frequency to levels observed in patients without AF. Confocal calcium imaging showed that β-blocker treatment also reduced the calcium spark frequency in patients with AF to levels observed in those without AF. Furthermore, phosphorylation of the ryanodine receptor (RyR2) at Ser-2808 and phospholamban at Ser-16 was significantly lower in patients with AF that received β-blockers. CONCLUSION Together, our findings demonstrate that β-blocker treatment may be of therapeutic utility to prevent spontaneous calcium release-induced atrial electrical activity; especially in patients with a history of paroxysmal AF displaying preserved ICa density.
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Affiliation(s)
- Verónica Jiménez-Sábado
- CIBER Enfermedades Cardiovasculares (CIBERCV), Instituto de Salud Carlos III, Madrid, Spain; IIB Sant Pau, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Sergi Casabella-Ramón
- IIB Sant Pau, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Instituto de Investigaciones Biomédicas de Barcelona (IIBB-CSIC), Barcelona, Spain; Department of Cell Biology, Physiology and Immunology and Neuroscience Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Anna Llach
- IIB Sant Pau, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Ignasi Gich
- IIB Sant Pau, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; CIBER Epidemiología y Salud Pública (CIBERESP), Instituto de Salud Carlos III, Madrid, Spain
| | - Sandra Casellas
- Servicio de Cirugía Cardíaca, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Francisco Ciruela
- Pharmacology Unit, Dept. Pathology and Experimental Therapeutics, School of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, L'Hospitalet de Llobregat, Spain; Neuropharmacology and Pain Group, Neuroscience Program, Institut d'Investigació Biomèdica de Bellvitge, IDIBELL, L'Hospitalet de Llobregat, Spain
| | - S R Wayne Chen
- Department of Physiology and Pharmacology, The Libin Cardiovascular Institute, University of Calgary, Canada
| | - José M Guerra
- CIBER Enfermedades Cardiovasculares (CIBERCV), Instituto de Salud Carlos III, Madrid, Spain; IIB Sant Pau, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Servicio de Cardiología and Univ. Autònoma de Barcelona, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Antonino Ginel
- Servicio de Cirugía Cardíaca, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Raúl Benítez
- Dept. d'Enginyeria de Sistemes, Automàtica i Informàtica Industrial, Univ. Politècnica de Catalunya, Barcelona, Spain
| | - Juan Cinca
- Servicio de Cardiología and Univ. Autònoma de Barcelona, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Carmen Tarifa
- IIB Sant Pau, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Instituto de Investigaciones Biomédicas de Barcelona (IIBB-CSIC), Barcelona, Spain
| | - Leif Hove-Madsen
- CIBER Enfermedades Cardiovasculares (CIBERCV), Instituto de Salud Carlos III, Madrid, Spain; IIB Sant Pau, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Instituto de Investigaciones Biomédicas de Barcelona (IIBB-CSIC), Barcelona, Spain.
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10
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Wei J, Guo W, Wang R, Paul Estillore J, Belke D, Chen YX, Vallmitjana A, Benitez R, Hove-Madsen L, Chen SRW. RyR2 Serine-2030 PKA Site Governs Ca 2+ Release Termination and Ca 2+ Alternans. Circ Res 2023; 132:e59-e77. [PMID: 36583384 DOI: 10.1161/circresaha.122.321177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND PKA (protein kinase A)-mediated phosphorylation of cardiac RyR2 (ryanodine receptor 2) has been extensively studied for decades, but the physiological significance of PKA phosphorylation of RyR2 remains poorly understood. Recent determination of high-resolution 3-dimensional structure of RyR2 in complex with CaM (calmodulin) reveals that the major PKA phosphorylation site in RyR2, serine-2030 (S2030), is located within a structural pathway of CaM-dependent inactivation of RyR2. This novel structural insight points to a possible role of PKA phosphorylation of RyR2 in CaM-dependent inactivation of RyR2, which underlies the termination of Ca2+ release and induction of cardiac Ca2+ alternans. METHODS We performed single-cell endoplasmic reticulum Ca2+ imaging to assess the impact of S2030 mutations on Ca2+ release termination in human embryonic kidney 293 cells. Here we determined the role of the PKA site RyR2-S2030 in a physiological setting, we generated a novel mouse model harboring the S2030L mutation and carried out confocal Ca2+ imaging. RESULTS We found that mutations, S2030D, S2030G, S2030L, S2030V, and S2030W reduced the endoplasmic reticulum luminal Ca2+ level at which Ca2+ release terminates (the termination threshold), whereas S2030P and S2030R increased the termination threshold. S2030A and S2030T had no significant impact on release termination. Furthermore, CaM-wild-type increased, whereas Ca2+ binding deficient CaM mutant (CaM-M [a loss-of-function CaM mutation with all 4 EF-hand motifs mutated]), PKA, and Ca2+/CaMKII (CaM-dependent protein kinase II) reduced the termination threshold. The S2030L mutation abolished the actions of CaM-wild-type, CaM-M, and PKA, but not CaMKII, in Ca2+ release termination. Moreover, we showed that isoproterenol and CaM-M suppressed pacing-induced Ca2+ alternans and accelerated Ca2+ transient recovery in intact working hearts, whereas CaM-wild-type exerted an opposite effect. The impact of isoproterenol was partially and fully reversed by the PKA inhibitor N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinoline-sulfonamide and the CaMKII inhibitor N-[2-[N-(4-chlorocinnamyl)-N-methylaminomethyl]phenyl]-N-(2-hydroxyethyl)-4-methoxybenzenesulfonamide individually and together, respectively. S2030L abolished the impact of CaM-wild-type, CaM-M, and N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinoline-sulfonamide-sensitive component, but not the N-[2-[N-(4-chlorocinnamyl)-N-methylaminomethyl]phenyl]-N-(2-hydroxyethyl)-4-methoxybenzenesulfonamide-sensitive component, of isoproterenol.
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Affiliation(s)
- Jinhong Wei
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta T2N 4N1, Canada (J.W., W.G., R.W., J.P.E., D.B., Y.-X.C., S.R.W.C.).,School of Medicine, Northwest University, Xi 'an, China (J.W.)
| | - Wenting Guo
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta T2N 4N1, Canada (J.W., W.G., R.W., J.P.E., D.B., Y.-X.C., S.R.W.C.)
| | - Ruiwu Wang
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta T2N 4N1, Canada (J.W., W.G., R.W., J.P.E., D.B., Y.-X.C., S.R.W.C.)
| | - John Paul Estillore
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta T2N 4N1, Canada (J.W., W.G., R.W., J.P.E., D.B., Y.-X.C., S.R.W.C.)
| | - Darrell Belke
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta T2N 4N1, Canada (J.W., W.G., R.W., J.P.E., D.B., Y.-X.C., S.R.W.C.)
| | - Yong-Xiang Chen
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta T2N 4N1, Canada (J.W., W.G., R.W., J.P.E., D.B., Y.-X.C., S.R.W.C.)
| | | | - Raul Benitez
- Department of Automatic Control, Universitat Politècnica de Catalunya, 08034 Barcelona, Spain (A.V., R.B.)
| | - Leif Hove-Madsen
- Biomedical Research Institute Barcelona IIBB-CSIC, IIB Sant Pau and CIBERCV, Hospital de Sant Pau, 08025, Barcelona, Spain (L.H.-M.)
| | - S R Wayne Chen
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta T2N 4N1, Canada (J.W., W.G., R.W., J.P.E., D.B., Y.-X.C., S.R.W.C.)
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11
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Yao J, Chen SRW. Corrigendum: R-carvedilol, a potential new therapy for Alzheimer's disease. Front Pharmacol 2023; 13:1125890. [PMID: 36712655 PMCID: PMC9878683 DOI: 10.3389/fphar.2022.1125890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 12/20/2022] [Indexed: 01/13/2023] Open
Abstract
[This corrects the article DOI: 10.3389/fphar.2022.1062495.].
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Affiliation(s)
- Jinjing Yao
- Department of Physiology and Pharmacology, Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada,Department of Physiology and Pharmacology, Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada,*Correspondence: Jinjing Yao, ; S. R. Wayne Chen,
| | - S. R. Wayne Chen
- Department of Physiology and Pharmacology, Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada,Department of Physiology and Pharmacology, Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada,*Correspondence: Jinjing Yao, ; S. R. Wayne Chen,
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12
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Yao J, Chen SRW. R-carvedilol, a potential new therapy for Alzheimer's disease. Front Pharmacol 2022; 13:1062495. [PMID: 36532759 PMCID: PMC9756136 DOI: 10.3389/fphar.2022.1062495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 11/15/2022] [Indexed: 11/25/2022] Open
Abstract
For decades, the amyloid cascade hypothesis has been the leading hypothesis in studying Alzheimer's disease (AD) pathology and drug development. However, a growing body of evidence indicates that simply removing amyloid plaques may not significantly affect AD progression. Alternatively, it has been proposed that AD progression is driven by increased neuronal excitability. Consistent with this alternative hypothesis, recent studies showed that pharmacologically limiting ryanodine receptor 2 (RyR2) open time with the R-carvedilol enantiomer prevented and reversed neuronal hyperactivity, memory impairment, and neuron loss in AD mouse models without affecting the accumulation of ß-amyloid (Aβ). These data indicate that R-carvedilol could be a potential new therapy for AD.
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Affiliation(s)
- Jinjing Yao
- Department of Physiology and Pharmacology, Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada,Department of Physiology and Pharmacology, Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada,*Correspondence: Jinjing Yao, ; S. R. Wayne Chen,
| | - S. R. Wayne Chen
- Department of Physiology and Pharmacology, Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada,Department of Physiology and Pharmacology, Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada,*Correspondence: Jinjing Yao, ; S. R. Wayne Chen,
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13
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Yao J, Liu Y, Sun B, Zhan X, Estillore JP, Turner RW, Chen SRW. Increased RyR2 open probability induces neuronal hyperactivity and memory loss with or without Alzheimer's disease-causing gene mutations. Alzheimers Dement 2022; 18:2088-2098. [PMID: 34985200 DOI: 10.1002/alz.12543] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 10/01/2021] [Accepted: 10/25/2021] [Indexed: 01/31/2023]
Abstract
INTRODUCTION Neuronal hyperactivity is an early neuronal defect commonly observed in familial and sporadic Alzheimer's disease (AD), but the underlying mechanisms are unclear. METHODS We employed a ryanodine receptor 2 (RyR2) mutant mouse model harboring the R4496C+/- mutation that markedly increases the channel's open probability (Po) to determine the impact of increased RyR2 activity in neuronal function without AD gene mutations. RESULTS Genetically increasing RyR2 Po induced neuronal hyperactivity in vivo in anesthetized and awake mice. Increased RyR2 Po induced hyperactive behaviors, impaired learning and memory, defective dendritic spines, and neuronal cell death. Increased RyR2 Po exacerbated the onset of neuronal hyperexcitability and learning and memory impairments in 5xFAD mice. DISCUSSION Increased RyR2 Po exacerbates the onset of familial AD-associated neuronal dysfunction, and induces AD-like defects in the absence of AD-causing gene mutations, suggesting that RyR2-associated neuronal hyperactivity represents a common target for combating AD with or without AD gene mutations.
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Affiliation(s)
- Jinjing Yao
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Yajing Liu
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, China
| | - Bo Sun
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Medical School, Kunming University of Science and Technology, Kunming, China
| | - Xiaoqin Zhan
- Hotchkiss Brain Institute, Department of Cell Biology and Anatomy, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - John Paul Estillore
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Ray W Turner
- Hotchkiss Brain Institute, Department of Cell Biology and Anatomy, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - S R Wayne Chen
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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14
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Nolla‐Colomer C, Casabella‐Ramon S, Jimenez‐Sabado V, Vallmitjana A, Tarifa C, Herraiz‐Martínez A, Llach A, Tauron M, Montiel J, Cinca J, Chen SRW, Benitez R, Hove‐Madsen L. β2-adrenergic stimulation potentiates spontaneous calcium release by increasing signal mass and co-activation of ryanodine receptor clusters. Acta Physiol (Oxf) 2022; 234:e13736. [PMID: 34709723 DOI: 10.1111/apha.13736] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 10/20/2021] [Accepted: 10/25/2021] [Indexed: 01/18/2023]
Abstract
AIMS It is unknown how β-adrenergic stimulation affects calcium dynamics in individual RyR2 clusters and leads to the induction of spontaneous calcium waves. To address this, we analysed spontaneous calcium release events in green fluorescent protein (GFP)-tagged RyR2 clusters. METHODS Cardiomyocytes from mice with GFP-tagged RyR2 or human right atrial tissue were subjected to immunofluorescent labelling or confocal calcium imaging. RESULTS Spontaneous calcium release from single RyR2 clusters induced 91.4% ± 2.0% of all calcium sparks while 8.0% ± 1.6% were caused by release from two neighbouring clusters. Sparks with two RyR2 clusters had 40% bigger amplitude, were 26% wider, and lasted 35% longer at half maximum. Consequently, the spark mass was larger in two- than one-cluster sparks with a median and interquartile range for the cumulative distribution of 15.7 ± 20.1 vs 7.6 ± 5.7 a.u. (P < .01). β2-adrenergic stimulation increased RyR2 phosphorylation at s2809 and s2815, tripled the fraction of two- and three-cluster sparks, and significantly increased the spark mass. Interestingly, the amplitude and mass of the calcium released from a RyR2 cluster were proportional to the SR calcium load, but the firing rate was not. The spark mass was also higher in 33 patients with atrial fibrillation than in 36 without (22.9 ± 23.4 a.u. vs 10.7 ± 10.9; P = .015). CONCLUSIONS Most sparks are caused by activation of a single RyR2 cluster at baseline while β-adrenergic stimulation doubles the mass and the number of clusters per spark. This mimics the shift in the cumulative spark mass distribution observed in myocytes from patients with atrial fibrillation.
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Affiliation(s)
| | - Sergi Casabella‐Ramon
- Biomedical Research Institute Barcelona, IIBB‐CSIC Barcelona Spain
- IIB Sant Pau Barcelona Spain
| | | | | | - Carmen Tarifa
- Biomedical Research Institute Barcelona, IIBB‐CSIC Barcelona Spain
- IIB Sant Pau Barcelona Spain
| | - Adela Herraiz‐Martínez
- Biomedical Research Institute Barcelona, IIBB‐CSIC Barcelona Spain
- IIB Sant Pau Barcelona Spain
| | | | - Manel Tauron
- Department of Cardiac Surgery Hospital de la Santa Creu i Sant Pau Barcelona Spain
| | - Jose Montiel
- Department of Cardiac Surgery Hospital de la Santa Creu i Sant Pau Barcelona Spain
| | - Juan Cinca
- IIB Sant Pau Barcelona Spain
- Universitat Autònoma de Barcelona Barcelona Spain
| | - S. R. Wayne Chen
- Department of Physiology and Pharmacology University of Calgary Alberta Canada
| | - Raul Benitez
- Department Automatic Control Univ. Politècnica de Catalunya Barcelona Spain
| | - Leif Hove‐Madsen
- Biomedical Research Institute Barcelona, IIBB‐CSIC Barcelona Spain
- IIB Sant Pau Barcelona Spain
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15
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Hiess F, Yao J, Song Z, Sun B, Zhang Z, Huang J, Chen L, Institoris A, Estillore JP, Wang R, Ter Keurs HEDJ, Stys PK, Gordon GR, Zamponi GW, Ganguly A, Chen SRW. Subcellular localization of hippocampal ryanodine receptor 2 and its role in neuronal excitability and memory. Commun Biol 2022; 5:183. [PMID: 35233070 PMCID: PMC8888588 DOI: 10.1038/s42003-022-03124-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 02/01/2022] [Indexed: 11/09/2022] Open
Abstract
Ryanodine receptor 2 (RyR2) is abundantly expressed in the heart and brain. Mutations in RyR2 are associated with both cardiac arrhythmias and intellectual disability. While the mechanisms of RyR2-linked arrhythmias are well characterized, little is known about the mechanism underlying RyR2-associated intellectual disability. Here, we employed a mouse model expressing a green fluorescent protein (GFP)-tagged RyR2 and a specific GFP probe to determine the subcellular localization of RyR2 in hippocampus. GFP-RyR2 was predominantly detected in the soma and dendrites, but not the dendritic spines of CA1 pyramidal neurons or dentate gyrus granular neurons. GFP-RyR2 was also detected within the mossy fibers in the stratum lucidum of CA3, but not in the presynaptic terminals of CA1 neurons. An arrhythmogenic RyR2-R4496C+/− mutation downregulated the A-type K+ current and increased membrane excitability, but had little effect on the afterhyperpolarization current or presynaptic facilitation of CA1 neurons. The RyR2-R4496C+/− mutation also impaired hippocampal long-term potentiation, learning, and memory. These data reveal the precise subcellular distribution of hippocampal RyR2 and its important role in neuronal excitability, learning, and memory. A mouse model containing a GFP-tagged ryanodine receptor 2 (RyR2) has shed light on the precise subcellular localization of hippocampal RyR2 and mechanisms underlying neuronal excitability, learning, and memory.
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Affiliation(s)
- Florian Hiess
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Jinjing Yao
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Zhenpeng Song
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Bo Sun
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Zizhen Zhang
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Junting Huang
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Lina Chen
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Adam Institoris
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - John Paul Estillore
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Ruiwu Wang
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Henk E D J Ter Keurs
- Libin Cardiovascular Institute, Department of Cardiovascular Science, Department of Medicine, University of Calgary, Calgary, AB, Canada
| | - Peter K Stys
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada.,Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada
| | - Grant R Gordon
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Gerald W Zamponi
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Anutosh Ganguly
- Department of Microbiology, Immunology, and Infectious Diseases, University of Calgary, Calgary, AB, Canada
| | - S R Wayne Chen
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, T2N 4N1, Canada. .,Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada.
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16
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Lebeau PF, Byun JH, Platko K, Saliba P, Sguazzin M, MacDonald ME, Paré G, Steinberg GR, Janssen LJ, Igdoura SA, Tarnopolsky MA, Wayne Chen SR, Seidah NG, Magolan J, Austin RC. Caffeine blocks SREBP2-induced hepatic PCSK9 expression to enhance LDLR-mediated cholesterol clearance. Nat Commun 2022; 13:770. [PMID: 35140212 PMCID: PMC8828868 DOI: 10.1038/s41467-022-28240-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 01/05/2022] [Indexed: 01/06/2023] Open
Abstract
Evidence suggests that caffeine (CF) reduces cardiovascular disease (CVD) risk. However, the mechanism by which this occurs has not yet been uncovered. Here, we investigated the effect of CF on the expression of two bona fide regulators of circulating low-density lipoprotein cholesterol (LDLc) levels; the proprotein convertase subtilisin/kexin type 9 (PCSK9) and the low-density lipoprotein receptor (LDLR). Following the observation that CF reduced circulating PCSK9 levels and increased hepatic LDLR expression, additional CF-derived analogs with increased potency for PCSK9 inhibition compared to CF itself were developed. The PCSK9-lowering effect of CF was subsequently confirmed in a cohort of healthy volunteers. Mechanistically, we demonstrate that CF increases hepatic endoplasmic reticulum (ER) Ca2+ levels to block transcriptional activation of the sterol regulatory element-binding protein 2 (SREBP2) responsible for the regulation of PCSK9, thereby increasing the expression of the LDLR and clearance of LDLc. Our findings highlight ER Ca2+ as a master regulator of cholesterol metabolism and identify a mechanism by which CF may protect against CVD.
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Affiliation(s)
- Paul F Lebeau
- Department of Medicine, Division of Nephrology, McMaster University, The Research Institute of St. Joe's Hamilton and the Hamilton Center for Kidney Research, Hamilton, ON, L8N 4A6, Canada
| | - Jae Hyun Byun
- Department of Medicine, Division of Nephrology, McMaster University, The Research Institute of St. Joe's Hamilton and the Hamilton Center for Kidney Research, Hamilton, ON, L8N 4A6, Canada
| | - Khrystyna Platko
- Department of Medicine, Division of Nephrology, McMaster University, The Research Institute of St. Joe's Hamilton and the Hamilton Center for Kidney Research, Hamilton, ON, L8N 4A6, Canada
| | - Paul Saliba
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, L8S 4L8, Canada
| | - Matthew Sguazzin
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, L8S 4L8, Canada
| | - Melissa E MacDonald
- Department of Medicine, Division of Nephrology, McMaster University, The Research Institute of St. Joe's Hamilton and the Hamilton Center for Kidney Research, Hamilton, ON, L8N 4A6, Canada
| | - Guillaume Paré
- Population Health Research Institute, McMaster University, Hamilton, ON, L8L 2X2, Canada.,The Departments of Medicine, Epidemiology and Pathology, McMaster University, Hamilton, ON, L8L 2X2, Canada.,The Thrombosis and Atherosclerosis Research Institute (TaARI), Department of Medicine, David Braley Research Institute, McMaster University, Hamilton, L8L 2X2, Canada
| | - Gregory R Steinberg
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, L8S 4L8, Canada.,Centre for Metabolism, Obesity and Diabetes Research, Department of Medicine, McMaster University, Hamilton, ON, L8S 4L8, Canada
| | - Luke J Janssen
- Firestone Institute for Respiratory Health, St. Joseph's Hospital, Hamilton, ON, L8S 4K1, Canada
| | - Suleiman A Igdoura
- Department of Biology and Pathology, McMaster University, Hamilton, ON, L8S 4K1, Canada
| | - Mark A Tarnopolsky
- Department of Medicine/Neurology, McMaster University, Hamilton, ON, L8N 3Z5, Canada.,Department of Pediatrics, McMaster University, Hamilton, ON, L8S 4K1, Canada
| | - S R Wayne Chen
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, T2N 2T9, Canada
| | - Nabil G Seidah
- Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, affiliated to the University of Montreal, Montreal, QC, H2W 1R7, Canada
| | - Jakob Magolan
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, L8S 4L8, Canada
| | - Richard C Austin
- Department of Medicine, Division of Nephrology, McMaster University, The Research Institute of St. Joe's Hamilton and the Hamilton Center for Kidney Research, Hamilton, ON, L8N 4A6, Canada. .,The Thrombosis and Atherosclerosis Research Institute (TaARI), Department of Medicine, David Braley Research Institute, McMaster University, Hamilton, L8L 2X2, Canada.
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17
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Ormerod JOM, Ormondroyd E, Li Y, Taylor J, Wei J, Guo W, Wang R, Sarton CNS, McGuire K, Dreau HMP, Taylor JC, Ginks MR, Rajappan K, Chen SRW, Watkins H. Provocation Testing and Therapeutic Response in a Newly Described Channelopathy: RyR2 Calcium Release Deficiency Syndrome. Circ Genom Precis Med 2022; 15:e003589. [PMID: 34949103 DOI: 10.1161/circgen.121.003589] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND A novel familial arrhythmia syndrome, cardiac ryanodine receptor (RyR2) calcium release deficiency syndrome (CRDS), has recently been described. We evaluated a large and well characterized family to assess provocation testing, risk factor stratification and response to therapy in CRDS. METHODS We present a family with multiple unheralded sudden cardiac deaths and aborted cardiac arrests, primarily in children and young adults, with no clear phenotype on standard clinical testing. RESULTS Genetic analysis, including whole genome sequencing, firmly established that a missense mutation in RYR2, Ala4142Thr, was the underlying cause of disease in the family. Functional study of the variant in a cell model showed RyR2 loss-of-function, indicating that the family was affected by CRDS. EPS (Electrophysiological Study) was undertaken in 9 subjects known to carry the mutation, including a survivor of aborted sudden cardiac death, and the effects of flecainide alone and in combination with metoprolol were tested. There was a clear gradation in inducibility of nonsustained and sustained ventricular arrhythmia between subjects at EPS, with the survivor of aborted sudden cardiac death being the most inducible subject. Administration of flecainide substantially reduced arrhythmia inducibility in this subject and abolished arrhythmia in all others. Finally, the effects of additional metoprolol were tested; it increased inducibility in 4/9 subjects. CONCLUSIONS The Ala4142Thr mutation of RYR2 causes the novel heritable arrhythmia syndrome CRDS, which is characterized by familial sudden death in the absence of prior symptoms or a recognizable phenotype on ambulatory monitoring or exercise stress testing. We increase the experience of a specific EPS protocol in human subjects and show that it is helpful in establishing the clinical status of gene carriers, with potential utility for risk stratification. Our data provide evidence that flecainide is protective in human subjects with CRDS, consistent with the effect previously shown in a mouse model.
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Affiliation(s)
- Julian O M Ormerod
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine (J.O.M.O., E.O., H.W.), University of Oxford, United Kingdom.,Cardiac Rhythm Management Service, Oxford Heart Centre, John Radcliffe Hospital, United Kingdom (J.O.M.O., M.R.G., K.R.)
| | - Elizabeth Ormondroyd
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine (J.O.M.O., E.O., H.W.), University of Oxford, United Kingdom
| | - Yanhui Li
- Department of Physiology and Pharmacology, The Libin Cardiovascular Institute, University of Calgary, AB, Canada (Y.L., J.W., W.G., R.W., S.R.W.C.).,Department of Internal Medicine, Institute of Hypertension, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China (Y.L.)
| | - John Taylor
- Oxford Medical Genetics Laboratories, Cardiac Service, Oxford University Hospitals NHS Trust, The Churchill Hospital, United Kingdom (J.T., C.N.S.S., K.M., J.C.T.)
| | - Jinhong Wei
- Department of Physiology and Pharmacology, The Libin Cardiovascular Institute, University of Calgary, AB, Canada (Y.L., J.W., W.G., R.W., S.R.W.C.)
| | - Wenting Guo
- Department of Physiology and Pharmacology, The Libin Cardiovascular Institute, University of Calgary, AB, Canada (Y.L., J.W., W.G., R.W., S.R.W.C.)
| | - Ruiwu Wang
- Department of Physiology and Pharmacology, The Libin Cardiovascular Institute, University of Calgary, AB, Canada (Y.L., J.W., W.G., R.W., S.R.W.C.)
| | - Caroline N S Sarton
- Oxford Medical Genetics Laboratories, Cardiac Service, Oxford University Hospitals NHS Trust, The Churchill Hospital, United Kingdom (J.T., C.N.S.S., K.M., J.C.T.)
| | - Karen McGuire
- Oxford Medical Genetics Laboratories, Cardiac Service, Oxford University Hospitals NHS Trust, The Churchill Hospital, United Kingdom (J.T., C.N.S.S., K.M., J.C.T.)
| | - Helene M P Dreau
- Molecular Diagnostic Centre, Department of Oncology (H.M.P.D.), University of Oxford, United Kingdom
| | - Jenny C Taylor
- Oxford Biomedical Research Centre and Wellcome Centre for Human Genetics (J.C.T., H.W.), University of Oxford, United Kingdom.,Oxford Medical Genetics Laboratories, Cardiac Service, Oxford University Hospitals NHS Trust, The Churchill Hospital, United Kingdom (J.T., C.N.S.S., K.M., J.C.T.)
| | - Matthew R Ginks
- Cardiac Rhythm Management Service, Oxford Heart Centre, John Radcliffe Hospital, United Kingdom (J.O.M.O., M.R.G., K.R.)
| | - Kim Rajappan
- Cardiac Rhythm Management Service, Oxford Heart Centre, John Radcliffe Hospital, United Kingdom (J.O.M.O., M.R.G., K.R.)
| | - S R Wayne Chen
- Department of Physiology and Pharmacology, The Libin Cardiovascular Institute, University of Calgary, AB, Canada (Y.L., J.W., W.G., R.W., S.R.W.C.)
| | - Hugh Watkins
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine (J.O.M.O., E.O., H.W.), University of Oxford, United Kingdom.,Oxford Biomedical Research Centre and Wellcome Centre for Human Genetics (J.C.T., H.W.), University of Oxford, United Kingdom
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18
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Arslanova A, Shafaattalab S, Ye K, Asghari P, Lin L, Kim B, Roston TM, Hove-Madsen L, Van Petegem F, Sanatani S, Moore E, Lynn F, Søndergaard M, Luo Y, Chen SRW, Tibbits GF. Using hiPSC-CMs to Examine Mechanisms of Catecholaminergic Polymorphic Ventricular Tachycardia. Curr Protoc 2021; 1:e320. [PMID: 34958715 DOI: 10.1002/cpz1.320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a potentially lethal inherited cardiac arrhythmia condition, triggered by physical or acute emotional stress, that predominantly expresses early in life. Gain-of-function mutations in the cardiac ryanodine receptor gene (RYR2) account for the majority of CPVT cases, causing substantial disruption of intracellular calcium (Ca2+ ) homeostasis particularly during the periods of β-adrenergic receptor stimulation. However, the highly variable penetrance, patient outcomes, and drug responses observed in clinical practice remain unexplained, even for patients with well-established founder RyR2 mutations. Therefore, investigation of the electrophysiological consequences of CPVT-causing RyR2 mutations is crucial to better understand the pathophysiology of the disease. The development of strategies for reprogramming human somatic cells to human induced pluripotent stem cells (hiPSCs) has provided a unique opportunity to study inherited arrhythmias, due to the ability of hiPSCs to differentiate down a cardiac lineage. Employment of genome editing enables generation of disease-specific cell lines from healthy and diseased patient-derived hiPSCs, which subsequently can be differentiated into cardiomyocytes. This paper describes the means for establishing an hiPSC-based model of CPVT in order to recapitulate the disease phenotype in vitro and investigate underlying pathophysiological mechanisms. The framework of this approach has the potential to contribute to disease modeling and personalized medicine using hiPSC-derived cardiomyocytes. © 2021 Wiley Periodicals LLC.
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Affiliation(s)
- Alia Arslanova
- Cellular and Regenerative Medicine Centre, British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada.,Molecular Cardiac Physiology Group, Departments of Biomedical Physiology and Kinesiology and Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Sanam Shafaattalab
- Cellular and Regenerative Medicine Centre, British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada.,Molecular Cardiac Physiology Group, Departments of Biomedical Physiology and Kinesiology and Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Kevin Ye
- Cellular and Regenerative Medicine Centre, British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada.,Molecular Cardiac Physiology Group, Departments of Biomedical Physiology and Kinesiology and Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Parisa Asghari
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lisa Lin
- Cellular and Regenerative Medicine Centre, British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada.,Molecular Cardiac Physiology Group, Departments of Biomedical Physiology and Kinesiology and Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - BaRun Kim
- Molecular Cardiac Physiology Group, Departments of Biomedical Physiology and Kinesiology and Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Thomas M Roston
- British Columbia Children's Hospital Heart Center, Vancouver, British Columbia, Canada
| | - Leif Hove-Madsen
- Cardiac Rhythm and Contraction Group, IIBB-CSIC, CIBERCV, IIB Sant Pau, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Shubhayan Sanatani
- British Columbia Children's Hospital Heart Center, Vancouver, British Columbia, Canada
| | - Edwin Moore
- Cardiac Rhythm and Contraction Group, IIBB-CSIC, CIBERCV, IIB Sant Pau, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Francis Lynn
- Cellular and Regenerative Medicine Centre, British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada
| | | | - Yonglun Luo
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - S R Wayne Chen
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada
| | - Glen F Tibbits
- Cellular and Regenerative Medicine Centre, British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada.,Molecular Cardiac Physiology Group, Departments of Biomedical Physiology and Kinesiology and Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada.,School of Biomedical Engineering, University of British Columbia, Vancouver, British Columbia, Canada
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19
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Roston TM, Wei J, Guo W, Li Y, Zhong X, Wang R, Estillore JP, Peltenburg PJ, Noguer FRI, Till J, Eckhardt LL, Orland KM, Hamilton R, LaPage MJ, Krahn AD, Tadros R, Vinocur JM, Kallas D, Franciosi S, Roberts JD, Wilde AAM, Jensen HK, Sanatani S, Chen SRW. Clinical and Functional Characterization of Ryanodine Receptor 2 Variants Implicated in Calcium-Release Deficiency Syndrome. JAMA Cardiol 2021; 7:84-92. [PMID: 34730774 DOI: 10.1001/jamacardio.2021.4458] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Importance Calcium-release deficiency syndrome (CRDS), which is caused by loss-of-function variants in cardiac ryanodine receptor 2 (RyR2), is an emerging cause of ventricular fibrillation. However, the lack of complex polymorphic/bidirectional ventricular tachyarrhythmias during exercise stress testing (EST) may distinguish it from catecholaminergic polymorphic ventricular tachycardia (CPVT). Recently, in the first clinical series describing the condition, mouse and human studies showed that the long-burst, long-pause, short-coupled ventricular extra stimulus (LBLPS) electrophysiology protocol reliably induced CRDS ventricular arrhythmias. Data from larger populations with CRDS and its associated spectrum of disease are lacking. Objective To further insight into CRDS through international collaboration. Design, Setting, and Participants In this multicenter observational cohort study, probands with unexplained life-threatening arrhythmic events and an ultrarare RyR2 variant were identified. Variants were expressed in HEK293 cells and subjected to caffeine stimulation to determine their functional impact. Data were collected from September 1, 2012, to March 6, 2021, and analyzed from August 9, 2015, to March 6, 2021. Main Outcomes and Measures The functional association of RyR2 variants found in putative cases of CRDS and the associated clinical phenotype(s). Results Of 10 RyR2 variants found in 10 probands, 6 were loss-of-function, consistent with CRDS (p.E4451del, p.F4499C, p.V4606E, p.R4608Q, p.R4608W, and p.Q2275H) (in 4 [67%] male and 2 [33%] female probands; median age at presentation, 22 [IQR, 8-34] years). In 5 probands with a documented trigger, 3 were catecholamine driven. During EST, 3 probands with CRDS had no arrhythmias, 1 had a monomorphic couplet, and 2 could not undergo EST (deceased). Relatives of the decedents carrying the RyR2 variant did not have EST results consistent with CPVT. After screening 3 families, 13 relatives were diagnosed with CRDS, including 3 with previous arrhythmic events (23%). None had complex ventricular tachyarrhythmias during EST. Among the 19 confirmed cases with CRDS, 10 had at least 1 life-threatening event at presentation and/or during a median follow-up of 7 (IQR, 6-18) years. Two of the 3 device-detected ventricular fibrillation episodes were induced by a spontaneous LBLPS-like sequence. β-Blockers were used in 16 of 17 surviving patients (94%). Three of 16 individuals who were reportedly adherent to β-blocker therapy (19%) had breakthrough events. Conclusions and Relevance The results of this study suggest that calcium-release deficiency syndrome due to RyR2 loss-of-function variants mechanistically and phenotypically differs from CPVT. Ventricular fibrillation may be precipitated by a spontaneous LBLPS-like sequence of ectopy; however, CRDS remains difficult to recognize clinically. These data highlight the need for better diagnostic tools and treatments for this emerging condition.
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Affiliation(s)
- Thomas M Roston
- Division of Cardiology, Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada.,Centre for Cardiovascular Innovation, Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jinhong Wei
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Wenting Guo
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Yanhui Li
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Xiaowei Zhong
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Ruiwu Wang
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - John Paul Estillore
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Puck J Peltenburg
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam University Medical Centre, Amsterdam, the Netherlands
| | | | - Jan Till
- Department of Cardiology, Royal Brompton Hospital, London, United Kingdom
| | - Lee L Eckhardt
- Division of Cardiovascular Medicine, University of Wisconsin, Madison
| | - Kate M Orland
- Division of Cardiovascular Medicine, University of Wisconsin, Madison
| | - Robert Hamilton
- Division of Cardiology, Department of Pediatrics, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Martin J LaPage
- Division of Cardiology, Department of Pediatrics, University of Michigan, Ann Arbor
| | - Andrew D Krahn
- Centre for Cardiovascular Innovation, Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Rafik Tadros
- Division of Cardiology, Montreal Heart Institute, University of Montreal, Montreal, Québec, Canada
| | - Jeffrey M Vinocur
- Department of Pediatrics, Hospital for Sick Children, Toronto, Ontario, Canada.,currently affiliated with Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut
| | - Dania Kallas
- Children's Heart Centre, Division of Cardiology, Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Sonia Franciosi
- Children's Heart Centre, Division of Cardiology, Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jason D Roberts
- Section of Cardiac Electrophysiology, Division of Cardiology, Western University, London, Ontario, Canada.,now affiliated with Population Health Research Institute, McMaster University and Hamilton Health Sciences, Hamilton, Ontario, Canada
| | - Arthur A M Wilde
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam University Medical Centre, Amsterdam, the Netherlands.,Member of the European Reference Network ERN GUARD-Heart
| | - Henrik K Jensen
- Department of Cardiology, Aarhus University Hospital, Aarhus, Denmark.,Department of Medicine, Aarhus University, Aarhus, Denmark
| | - Shubhayan Sanatani
- Children's Heart Centre, Division of Cardiology, Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada
| | - S R Wayne Chen
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
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20
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Li Y, Wei J, Guo W, Sun B, Estillore JP, Wang R, Yoruk A, Roston TM, Sanatani S, Wilde AAM, Gollob MH, Roberts JD, Tseng ZH, Jensen HK, Chen SRW. Human RyR2 (Ryanodine Receptor 2) Loss-of-Function Mutations: Clinical Phenotypes and In Vitro Characterization. Circ Arrhythm Electrophysiol 2021; 14:e010013. [PMID: 34546788 DOI: 10.1161/circep.121.010013] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Yanhui Li
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, AB, Canada (Y.L., J.W., W.G., B.S., J.P.E., R.W., S.R.W.C.).,Department of Internal Medicine, Institute of Hypertension, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China (Y.L.)
| | - Jinhong Wei
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, AB, Canada (Y.L., J.W., W.G., B.S., J.P.E., R.W., S.R.W.C.)
| | - Wenting Guo
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, AB, Canada (Y.L., J.W., W.G., B.S., J.P.E., R.W., S.R.W.C.)
| | - Bo Sun
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, AB, Canada (Y.L., J.W., W.G., B.S., J.P.E., R.W., S.R.W.C.).,Medical School, Kunming University of Science and Technology, China (B.S.)
| | - John Paul Estillore
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, AB, Canada (Y.L., J.W., W.G., B.S., J.P.E., R.W., S.R.W.C.)
| | - Ruiwu Wang
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, AB, Canada (Y.L., J.W., W.G., B.S., J.P.E., R.W., S.R.W.C.)
| | - Ayhan Yoruk
- Cardiac Electrophysiology Section, Division of Cardiology, Department of Medicine, University of California, San Francisco (A.Y., Z.H.T.)
| | - Thomas M Roston
- Division of Cardiology, Department of Medicine (T.M.R.), University of British Columbia, Vancouver, Canada
| | - Shubhayan Sanatani
- Child and Family Research Institute, Department of Pediatrics (S.S.), University of British Columbia, Vancouver, Canada
| | - Arthur A M Wilde
- Heart Center, Department of Clinical and Experimental Cardiology, Amsterdam University Medical Centre, location AMC, the Netherlands (A.A.M.W.).,Member of the European Reference Network 'ERN GUARD-Heart' (A.A.M.W.)
| | - Michael H Gollob
- Inherited Arrhythmia and Cardiomyopathy Program, Arrhythmia Service, Division of Cardiology, Toronto General Hospital (M.H.G.), University of Toronto, ON, Canada.,Department of Physiology (M.H.G.), University of Toronto, ON, Canada
| | - Jason D Roberts
- Population Health Research Institute, McMaster University and Hamilton Health Sciences, Hamilton, ON, Canada (J.D.R.)
| | - Zian H Tseng
- Cardiac Electrophysiology Section, Division of Cardiology, Department of Medicine, University of California, San Francisco (A.Y., Z.H.T.)
| | - Henrik K Jensen
- Department of Cardiology, Aarhus University Hospital and Department of Clinical Medicine, Health, Aarhus University, Denmark (H.K.J.)
| | - S R Wayne Chen
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, AB, Canada (Y.L., J.W., W.G., B.S., J.P.E., R.W., S.R.W.C.)
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21
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Liu Y, Yao J, Song Z, Guo W, Sun B, Wei J, Estillore JP, Back TG, Chen SRW. Limiting RyR2 open time prevents Alzheimer's disease-related deficits in the 3xTG-AD mouse model. J Neurosci Res 2021; 99:2906-2921. [PMID: 34352124 DOI: 10.1002/jnr.24936] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 06/11/2021] [Accepted: 07/14/2021] [Indexed: 12/24/2022]
Abstract
Increasing evidence suggests that Alzheimer's disease (AD) progression is driven by a vicious cycle of soluble β-amyloid (Aβ)-induced neuronal hyperactivity. Thus, breaking this vicious cycle by suppressing neuronal hyperactivity may represent a logical approach to stopping AD progression. In support of this, we have recently shown that genetically and pharmacologically limiting ryanodine receptor 2 (RyR2) open time prevented neuronal hyperactivity, memory impairment, dendritic spine loss, and neuronal cell death in a rapid, early onset AD mouse model (5xFAD). Here, we assessed the impact of limiting RyR2 open time on AD-related deficits in a relatively late occurring, slow developing AD mouse model (3xTG-AD) that bears more resemblance (compared to 5xFAD) to that of human AD. Using behavioral tests, long-term potentiation recordings, and Golgi and Nissl staining, we found that the RyR2-E4872Q mutation, which markedly shortens the open duration of the RyR2 channel, prevented learning and memory impairment, defective long-term potentiation, dendritic spine loss, and neuronal cell death in the 3xTG-AD mice. Furthermore, pharmacologically shortening the RyR2 open time with R-carvedilol rescued these AD-related deficits in 3xTG mice. Therefore, limiting RyR2 open time may offer a promising, neuronal hyperactivity-targeted anti-AD strategy.
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Affiliation(s)
- Yajing Liu
- Department of Physiology and Pharmacology, Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada.,Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, China
| | - Jinjing Yao
- Department of Physiology and Pharmacology, Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada
| | - Zhenpeng Song
- Department of Physiology and Pharmacology, Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada
| | - Wenting Guo
- Department of Physiology and Pharmacology, Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada
| | - Bo Sun
- Department of Physiology and Pharmacology, Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada.,Medical School, Kunming University of Science and Technology, Kunming, China
| | - Jinhong Wei
- Department of Physiology and Pharmacology, Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada
| | - John Paul Estillore
- Department of Physiology and Pharmacology, Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada
| | - Thomas G Back
- Department of Chemistry, University of Calgary, Calgary, AB, Canada
| | - S R Wayne Chen
- Department of Physiology and Pharmacology, Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
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22
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Sun B, Yao J, Ni M, Wei J, Zhong X, Guo W, Zhang L, Wang R, Belke D, Chen YX, Lieve KVV, Broendberg AK, Roston TM, Blankoff I, Kammeraad JA, von Alvensleben JC, Lazarte J, Vallmitjana A, Bohne LJ, Rose RA, Benitez R, Hove-Madsen L, Napolitano C, Hegele RA, Fill M, Sanatani S, Wilde AAM, Roberts JD, Priori SG, Jensen HK, Chen SRW. Cardiac ryanodine receptor calcium release deficiency syndrome. Sci Transl Med 2021; 13:13/579/eaba7287. [PMID: 33536282 DOI: 10.1126/scitranslmed.aba7287] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 12/07/2020] [Indexed: 11/02/2022]
Abstract
Cardiac ryanodine receptor (RyR2) gain-of-function mutations cause catecholaminergic polymorphic ventricular tachycardia, a condition characterized by prominent ventricular ectopy in response to catecholamine stress, which can be reproduced on exercise stress testing (EST). However, reports of sudden cardiac death (SCD) have emerged in EST-negative individuals who have loss-of-function (LOF) RyR2 mutations. The clinical relevance of RyR2 LOF mutations including their pathogenic mechanism, diagnosis, and treatment are all unknowns. Here, we performed clinical and genetic evaluations of individuals who suffered from SCD and harbored an LOF RyR2 mutation. We carried out electrophysiological studies using a programed electrical stimulation protocol consisting of a long-burst, long-pause, and short-coupled (LBLPS) ventricular extra-stimulus. Linkage analysis of RyR2 LOF mutations in six families revealed a combined logarithm of the odds ratio for linkage score of 11.479 for a condition associated with SCD with negative EST. A RyR2 LOF mouse model exhibited no catecholamine-provoked ventricular arrhythmias as in humans but did have substantial cardiac electrophysiological remodeling and an increased propensity for early afterdepolarizations. The LBLPS pacing protocol reliably induced ventricular arrhythmias in mice and humans having RyR2 LOF mutations, whose phenotype is otherwise concealed before SCD. Furthermore, treatment with quinidine and flecainide abolished LBLPS-induced ventricular arrhythmias in model mice. Thus, RyR2 LOF mutations underlie a previously unknown disease entity characterized by SCD with normal EST that we have termed RyR2 Ca2+ release deficiency syndrome (CRDS). Our study provides insights into the mechanism of CRDS, reports a specific CRDS diagnostic test, and identifies potentially efficacious anti-CRDS therapies.
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Affiliation(s)
- Bo Sun
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB T2N 4Z6, Canada.,Medical School, Kunming University of Science and Technology, Kunming 650504, China
| | - Jinjing Yao
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Mingke Ni
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Jinhong Wei
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Xiaowei Zhong
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Wenting Guo
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Lin Zhang
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Ruiwu Wang
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Darrell Belke
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Yong-Xiang Chen
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Krystien V V Lieve
- Amsterdam University Medical Centre, location AMC, Heart Center, Department of Clinical and Experimental Cardiology, Amsterdam 1105AZ, Netherlands.,European Reference Network 'ERN GUARD-Heart', Amsterdam, Netherlands
| | - Anders K Broendberg
- Department of Cardiology, Aarhus University Hospital, and Department of Clinical Medicine, Health, Aarhus University, Palle Juul-Jensens Blv 99, DK-8200 Aarhus N, Denmark
| | - Thomas M Roston
- Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, BC V5Z 1M9, Canada
| | - Ivan Blankoff
- C.H.U. Charleroi, Hôpital Civil Marie Curie Chaussée de Bruxelles 140 6042 Charleroi, Belgium
| | - Janneke A Kammeraad
- Department of Pediatric Cardiology, Sophia Children's Hospital, Erasmus University Medical Centre, Doctor Molewaterplein 40, 3015 GD Rotterdam, Netherlands
| | - Johannes C von Alvensleben
- Division of Cardiology, Heart Institute, Children's Hospital Colorado, University of Colorado, Aurora, CO 80045, USA
| | - Julieta Lazarte
- Department of Medicine and Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5B7, Canada
| | - Alexander Vallmitjana
- Department of Automatic Control, Universitat Politècnica de Catalunya, 08034 Barcelona, Spain
| | - Loryn J Bohne
- Departments of Cardiac Sciences and Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Robert A Rose
- Departments of Cardiac Sciences and Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Raul Benitez
- Department of Automatic Control, Universitat Politècnica de Catalunya, 08034 Barcelona, Spain
| | - Leif Hove-Madsen
- Biomedical Research Institute Barcelona (IIBB-CSIC) and IIB Sant Pau, Hospital de Sant Pau, Barcelona 08025, Spain
| | - Carlo Napolitano
- European Reference Network 'ERN GUARD-Heart', Amsterdam, Netherlands.,Division of Cardiology and Molecular Cardiology, IRCCS Maugeri Foundation-University of Pavia, 27100 Pavia, Italy.,Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
| | - Robert A Hegele
- Department of Medicine and Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 5B7, Canada
| | - Michael Fill
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, IL 60612, USA
| | - Shubhayan Sanatani
- Child and Family Research Institute, Department of Pediatrics, University of British Columbia, Vancouver, BC V6H 3V4, Canada.
| | - Arthur A M Wilde
- Amsterdam University Medical Centre, location AMC, Heart Center, Department of Clinical and Experimental Cardiology, Amsterdam 1105AZ, Netherlands. .,European Reference Network 'ERN GUARD-Heart', Amsterdam, Netherlands
| | - Jason D Roberts
- Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, ON N6A 5A5, Canada.
| | - Silvia G Priori
- European Reference Network 'ERN GUARD-Heart', Amsterdam, Netherlands. .,Division of Cardiology and Molecular Cardiology, IRCCS Maugeri Foundation-University of Pavia, 27100 Pavia, Italy.,Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy.,Molecular Cardiology Laboratory, Centro de Investigaciones Cardiovasculares Carlos III, 28029 Madrid, Spain
| | - Henrik K Jensen
- Department of Cardiology, Aarhus University Hospital, and Department of Clinical Medicine, Health, Aarhus University, Palle Juul-Jensens Blv 99, DK-8200 Aarhus N, Denmark.
| | - S R Wayne Chen
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB T2N 4Z6, Canada. .,Department of Physiology and Biophysics, Rush University Medical Center, Chicago, IL 60612, USA
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23
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Sun B, Yao J, Chen AW, Estillore JP, Wang R, Back TG, Chen SRW. Genetically and pharmacologically limiting RyR2 open time prevents neuronal hyperactivity of hippocampal CA1 neurons in brain slices of 5xFAD mice. Neurosci Lett 2021; 758:136011. [PMID: 34090936 DOI: 10.1016/j.neulet.2021.136011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 03/19/2021] [Accepted: 05/28/2021] [Indexed: 12/11/2022]
Abstract
Neuronal hyperactivity is an early, common manifestation of Alzheimer's disease (AD), and is believed to drive AD progression. Neuronal hyperactivity in the form of baseline activity (or spontaneous Ca2+ transients) has consistently been demonstrated in mouse models of AD using two-photon in vivo Ca2+ imaging of cortical or hippocampal neurons in anesthetized animals. Notably, these AD-related spontaneous Ca2+ transients were hardly detected in acute hippocampal slices, probably due to neuronal damage during brain slicing. To better preserve neuronal activity, we employed the N-methyl-D-glucamine (NMDG) protective brain slicing protocol. We performed confocal in vitro Ca2+ imaging of hippocampal CA1 neurons in optimized hippocampal slices. Consistent with previous in vivo studies, our in vitro studies using optimized brain slices also showed that limiting the open duration of the ryanodine receptor 2 (RyR2) by the RyR2 mutation E4872Q or by the R-carvedilol enantiomer prevented and rescued neuronal hyperactivity of hippocampal CA1 neurons from 5xFAD mice. Thus, genetically and pharmacologically limiting RyR2 open time prevented and rescued AD-related neuronal hyperactivity in vitro in optimized brain slices in the absence of anesthetics' influence. Our data also suggest that the NMDG protective brain slicing preparation offers an alternative means to study neuronal hyperactivity of various cell types in different brain regions, especially in regions that are not readily accessible to two-photon in vivo Ca2+ imaging.
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Affiliation(s)
- Bo Sun
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Jinjing Yao
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Alexander W Chen
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - John Paul Estillore
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Ruiwu Wang
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Thomas G Back
- Department of Chemistry, University of Calgary, Calgary, AB, Canada
| | - S R Wayne Chen
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.
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24
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Guo W, Wei J, Estillore JP, Zhang L, Wang R, Sun B, Chen SRW. RyR2 disease mutations at the C-terminal domain intersubunit interface alter closed-state stability and channel activation. J Biol Chem 2021; 297:100808. [PMID: 34022226 PMCID: PMC8214192 DOI: 10.1016/j.jbc.2021.100808] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 05/14/2021] [Accepted: 05/18/2021] [Indexed: 11/19/2022] Open
Abstract
Ryanodine receptors (RyRs) are ion channels that mediate the release of Ca2+ from the sarcoplasmic reticulum/endoplasmic reticulum, mutations of which are implicated in a number of human diseases. The adjacent C-terminal domains (CTDs) of cardiac RyR (RyR2) interact with each other to form a ring-like tetrameric structure with the intersubunit interface undergoing dynamic changes during channel gating. This mobile CTD intersubunit interface harbors many disease-associated mutations. However, the mechanisms of action of these mutations and the role of CTD in channel function are not well understood. Here, we assessed the impact of CTD disease-associated mutations P4902S, P4902L, E4950K, and G4955E on Ca2+− and caffeine-mediated activation of RyR2. The G4955E mutation dramatically increased both the Ca2+-independent basal activity and Ca2+-dependent activation of [3H]ryanodine binding to RyR2. The P4902S and E4950K mutations also increased Ca2+ activation but had no effect on the basal activity of RyR2. All four disease mutations increased caffeine-mediated activation of RyR2 and reduced the threshold for activation and termination of spontaneous Ca2+ release. G4955D dramatically increased the basal activity of RyR2, whereas G4955K mutation markedly suppressed channel activity. Similarly, substitution of P4902 with a negatively charged residue (P4902D), but not a positively charged residue (P4902K), also dramatically increased the basal activity of RyR2. These data suggest that electrostatic interactions are involved in stabilizing the CTD intersubunit interface and that the G4955E disease mutation disrupts this interface, and thus the stability of the closed state. Our studies shed new insights into the mechanisms of action of RyR2 CTD disease mutations.
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Affiliation(s)
- Wenting Guo
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Jinhong Wei
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - John Paul Estillore
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Lin Zhang
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Ruiwu Wang
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Bo Sun
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada; Medical School, Kunming University of Science and Technology, Kunming, China.
| | - S R Wayne Chen
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.
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25
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Yao J, Sun B, Institoris A, Zhan X, Guo W, Song Z, Liu Y, Hiess F, Boyce AKJ, Ni M, Wang R, Ter Keurs H, Back TG, Fill M, Thompson RJ, Turner RW, Gordon GR, Chen SRW. Limiting RyR2 Open Time Prevents Alzheimer's Disease-Related Neuronal Hyperactivity and Memory Loss but Not β-Amyloid Accumulation. Cell Rep 2021; 32:108169. [PMID: 32966798 PMCID: PMC7532726 DOI: 10.1016/j.celrep.2020.108169] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 07/23/2020] [Accepted: 08/27/2020] [Indexed: 12/31/2022] Open
Abstract
Neuronal hyperactivity is an early primary dysfunction in Alzheimer’s disease (AD) in humans and animal models, but effective neuronal hyperactivity-directed anti-AD therapeutic agents are lacking. Here we define a previously unknown mode of ryanodine receptor 2 (RyR2) control of neuronal hyperactivity and AD progression. We show that a single RyR2 point mutation, E4872Q, which reduces RyR2 open time, prevents hyperexcitability, hyperactivity, memory impairment, neuronal cell death, and dendritic spine loss in a severe early-onset AD mouse model (5xFAD). The RyR2-E4872Q mutation upregulates hippocampal CA1-pyramidal cell A-type K+ current, a well-known neuronal excitability control that is downregulated in AD. Pharmacologically limiting RyR2 open time with the R-carvedilol enantiomer (but not racemic carvedilol) prevents and rescues neuronal hyperactivity, memory impairment, and neuron loss even in late stages of AD. These AD-related deficits are prevented even with continued β-amyloid accumulation. Thus, limiting RyR2 open time may be a hyperactivity-directed, non-β-amyloid-targeted anti-AD strategy. Yao et al. show that genetically or pharmacologically limiting the open duration of ryanodine receptor 2 upregulates the A-type potassium current and prevents neuronal hyperexcitability and hyperactivity, memory impairment, neuronal cell death, and dendritic spine loss in a severe early-onset Alzheimer’s disease mouse model, even with continued accumulation of β-amyloid.
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Affiliation(s)
- Jinjing Yao
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Bo Sun
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada; Medical School, Kunming University of Science and Technology, Kunming 650504, China
| | - Adam Institoris
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Xiaoqin Zhan
- Hotchkiss Brain Institute, Department of Cell Biology and Anatomy, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Wenting Guo
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Zhenpeng Song
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Yajing Liu
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Florian Hiess
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Andrew K J Boyce
- Hotchkiss Brain Institute, Department of Cell Biology and Anatomy, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Mingke Ni
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Ruiwu Wang
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Henk Ter Keurs
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Thomas G Back
- Department of Chemistry, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Michael Fill
- Department of Physiology & Biophysics, Rush University Medical Center, Chicago, IL 60612, USA
| | - Roger J Thompson
- Hotchkiss Brain Institute, Department of Cell Biology and Anatomy, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Ray W Turner
- Hotchkiss Brain Institute, Department of Cell Biology and Anatomy, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Grant R Gordon
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - S R Wayne Chen
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada; Department of Physiology & Biophysics, Rush University Medical Center, Chicago, IL 60612, USA.
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26
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Shauer A, Shor O, Wei J, Elitzur Y, Kucherenko N, Wang R, Chen SRW, Einav Y, Luria D. Novel RyR2 Mutation (G3118R) Is Associated With Autosomal Recessive Ventricular Fibrillation and Sudden Death: Clinical, Functional, and Computational Analysis. J Am Heart Assoc 2021; 10:e017128. [PMID: 33686871 PMCID: PMC8174198 DOI: 10.1161/jaha.120.017128] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Background The cardiac ryanodine receptor type 2 (RyR2) is a large homotetramer, located in the sarcoplasmic reticulum (SR), which releases Ca2+ from the SR during systole. The molecular mechanism underlying Ca2+ sensing and gating of the RyR2 channel in health and disease is only partially elucidated. Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT1) is the most prevalent syndrome caused by RyR2 mutations. Methods and Results This study involves investigation of a family with 4 cases of ventricular fibrillation and sudden death and physiological tests in HEK 293 cells and normal mode analysis (NMA) computation. We found 4 clinically affected members who were homozygous for a novel RyR2 mutation, G3118R, whereas their heterozygous relatives are asymptomatic. G3118R is located in the periphery of the protein, far from the mutation hotspot regions. HEK293 cells harboring G3118R mutation inhibited Ca2+ release in response to increasing doses of caffeine, but decreased the termination threshold for store‐overload‐induced Ca2+ release, thus increasing the fractional Ca2+ release in response to increasing extracellular Ca2+. NMA showed that G3118 affects RyR2 tetramer in a dose‐dependent manner, whereas in the model of homozygous mutant RyR2, the highest entropic values are assigned to the pore and the central regions of the protein. Conclusions RyR2 G3118R is related to ventricular fibrillation and sudden death in recessive mode of inheritance and has an effect of gain of function on the protein. Despite a peripheral location, it has an allosteric effect on the stability of central and pore regions in a dose‐effect manner.
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Affiliation(s)
- Ayelet Shauer
- Heart Institute Hadassah-Hebrew University Medical Center Jerusalem Israel
| | - Oded Shor
- Heart Institute Hadassah-Hebrew University Medical Center Jerusalem Israel
| | - Jinhong Wei
- Department of Physiology and Pharmacology The Libin Cardiovascular Institute of AlbertaUniversity of Calgary Alberta Canada
| | - Yair Elitzur
- Heart Institute Hadassah-Hebrew University Medical Center Jerusalem Israel
| | - Nataly Kucherenko
- Biochemistry and Molecular Biology Tel Aviv University Tel Aviv Israel
| | - Ruiwu Wang
- Department of Physiology and Pharmacology The Libin Cardiovascular Institute of AlbertaUniversity of Calgary Alberta Canada
| | - S R Wayne Chen
- Department of Physiology and Pharmacology The Libin Cardiovascular Institute of AlbertaUniversity of Calgary Alberta Canada
| | - Yulia Einav
- Faculty of Engineering Holon Institute of Technology Holon Israel
| | - David Luria
- Heart Institute Hadassah-Hebrew University Medical Center Jerusalem Israel
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27
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Wei J, Yao J, Belke D, Guo W, Zhong X, Sun B, Wang R, Paul Estillore J, Vallmitjana A, Benitez R, Hove-Madsen L, Alvarez-Lacalle E, Echebarria B, Chen SRW. Ca 2+-CaM Dependent Inactivation of RyR2 Underlies Ca 2+ Alternans in Intact Heart. Circ Res 2020; 128:e63-e83. [PMID: 33375811 DOI: 10.1161/circresaha.120.318429] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
RATIONALE Ca2+ alternans plays an essential role in cardiac alternans that can lead to ventricular fibrillation, but the mechanism underlying Ca2+ alternans remains undefined. Increasing evidence suggests that Ca2+ alternans results from alternations in the inactivation of cardiac RyR2 (ryanodine receptor 2). However, what inactivates RyR2 and how RyR2 inactivation leads to Ca2+ alternans are unknown. OBJECTIVE To determine the role of CaM (calmodulin) on Ca2+ alternans in intact working mouse hearts. METHODS AND RESULTS We used an in vivo local gene delivery approach to alter CaM function by directly injecting adenoviruses expressing CaM-wild type, a loss-of-function CaM mutation, CaM (1-4), and a gain-of-function mutation, CaM-M37Q, into the anterior wall of the left ventricle of RyR2 wild type or mutant mouse hearts. We monitored Ca2+ transients in ventricular myocytes near the adenovirus-injection sites in Langendorff-perfused intact working hearts using confocal Ca2+ imaging. We found that CaM-wild type and CaM-M37Q promoted Ca2+ alternans and prolonged Ca2+ transient recovery in intact RyR2 wild type and mutant hearts, whereas CaM (1-4) exerted opposite effects. Altered CaM function also affected the recovery from inactivation of the L-type Ca2+ current but had no significant impact on sarcoplasmic reticulum Ca2+ content. Furthermore, we developed a novel numerical myocyte model of Ca2+ alternans that incorporates Ca2+-CaM-dependent regulation of RyR2 and the L-type Ca2+ channel. Remarkably, the new model recapitulates the impact on Ca2+ alternans of altered CaM and RyR2 functions under 9 different experimental conditions. Our simulations reveal that diastolic cytosolic Ca2+ elevation as a result of rapid pacing triggers Ca2+-CaM dependent inactivation of RyR2. The resultant RyR2 inactivation diminishes sarcoplasmic reticulum Ca2+ release, which, in turn, reduces diastolic cytosolic Ca2+, leading to alternations in diastolic cytosolic Ca2+, RyR2 inactivation, and sarcoplasmic reticulum Ca2+ release (ie, Ca2+ alternans). CONCLUSIONS Our results demonstrate that inactivation of RyR2 by Ca2+-CaM is a major determinant of Ca2+ alternans, making Ca2+-CaM dependent regulation of RyR2 an important therapeutic target for cardiac alternans.
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Affiliation(s)
- Jinhong Wei
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (J.W., J.Y., D.B., W.G., X.Z., B.S., R.W., J.P.E., S.R.W.C.)
| | - Jinjing Yao
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (J.W., J.Y., D.B., W.G., X.Z., B.S., R.W., J.P.E., S.R.W.C.)
| | - Darrell Belke
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (J.W., J.Y., D.B., W.G., X.Z., B.S., R.W., J.P.E., S.R.W.C.)
| | - Wenting Guo
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (J.W., J.Y., D.B., W.G., X.Z., B.S., R.W., J.P.E., S.R.W.C.)
| | - Xiaowei Zhong
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (J.W., J.Y., D.B., W.G., X.Z., B.S., R.W., J.P.E., S.R.W.C.)
| | - Bo Sun
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (J.W., J.Y., D.B., W.G., X.Z., B.S., R.W., J.P.E., S.R.W.C.)
| | - Ruiwu Wang
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (J.W., J.Y., D.B., W.G., X.Z., B.S., R.W., J.P.E., S.R.W.C.)
| | - John Paul Estillore
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (J.W., J.Y., D.B., W.G., X.Z., B.S., R.W., J.P.E., S.R.W.C.)
| | - Alexander Vallmitjana
- Department of Automatic Control, Universitat Politècnica de Catalunya, Barcelona, Spain (A.V., R.B.)
| | - Raul Benitez
- Department of Automatic Control, Universitat Politècnica de Catalunya, Barcelona, Spain (A.V., R.B.).,Institut de Recerca Sant Joan de Déu (IRSJD), Barcelona, Spain (R.B.)
| | - Leif Hove-Madsen
- Biomedical Research Institute Barcelona IIBB-CSIC, CIBERCV and IIB Sant Pau, Hospital de Sant Pau, Barcelona, Spain (L.H.-M.)
| | - Enrique Alvarez-Lacalle
- Department of Physics, Universitat Politècnica de Catalunya, Barcelona, Spain (E.A.-L., B.E.)
| | - Blas Echebarria
- Department of Physics, Universitat Politècnica de Catalunya, Barcelona, Spain (E.A.-L., B.E.)
| | - S R Wayne Chen
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (J.W., J.Y., D.B., W.G., X.Z., B.S., R.W., J.P.E., S.R.W.C.)
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28
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Guo W, Sun B, Estillore JP, Wang R, Chen SRW. The central domain of cardiac ryanodine receptor governs channel activation, regulation, and stability. J Biol Chem 2020; 295:15622-15635. [PMID: 32878990 DOI: 10.1074/jbc.ra120.013512] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 08/25/2020] [Indexed: 11/06/2022] Open
Abstract
Structural analyses identified the central domain of ryanodine receptor (RyR) as a transducer converting conformational changes in the cytoplasmic platform to the RyR gate. The central domain is also a regulatory hub encompassing the Ca2+-, ATP-, and caffeine-binding sites. However, the role of the central domain in RyR activation and regulation has yet to be defined. Here, we mutated five residues that form the Ca2+ activation site and 10 residues with negatively charged or oxygen-containing side chains near the Ca2+ activation site. We also generated eight disease-associated mutations within the central domain of RyR2. We determined the effect of these mutations on Ca2+, ATP, and caffeine activation and Mg2+ inhibition of RyR2. Mutating the Ca2+ activation site markedly reduced the sensitivity of RyR2 to Ca2+ and caffeine activation. Unexpectedly, Ca2+ activation site mutation E3848A substantially enhanced the Ca2+-independent basal activity of RyR2, suggesting that E3848A may also affect the stability of the closed state of RyR2. Mutations in the Ca2+ activation site also abolished the effect of ATP/caffeine on the Ca2+-independent basal activity, suggesting that the Ca2+ activation site is also a critical determinant of ATP/caffeine action. Mutating residues with negatively charged or oxygen-containing side chains near the Ca2+ activation site significantly altered Ca2+ and caffeine activation and reduced Mg2+ inhibition. Furthermore, disease-associated RyR2 mutations within the central domain significantly enhanced Ca2+ and caffeine activation and reduced Mg2+ inhibition. Our data demonstrate that the central domain plays an important role in channel activation, channel regulation, and closed state stability.
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Affiliation(s)
- Wenting Guo
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada; Department of Biochemistry and Molecular Biology, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada
| | - Bo Sun
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada; Department of Biochemistry and Molecular Biology, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada; Medical School, Kunming University of Science and Technology, Kunming, China
| | - John Paul Estillore
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada; Department of Biochemistry and Molecular Biology, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada
| | - Ruiwu Wang
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada; Department of Biochemistry and Molecular Biology, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada
| | - S R Wayne Chen
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada; Department of Biochemistry and Molecular Biology, Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada.
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29
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Søndergaard MT, Liu Y, Guo W, Wei J, Wang R, Brohus M, Overgaard MT, Chen SRW. Role of cardiac ryanodine receptor calmodulin-binding domains in mediating the action of arrhythmogenic calmodulin N-domain mutation N54I. FEBS J 2019; 287:2256-2280. [PMID: 31763755 DOI: 10.1111/febs.15147] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 09/12/2019] [Accepted: 11/19/2019] [Indexed: 11/27/2022]
Abstract
The Ca2+ -sensing protein calmodulin (CaM) inhibits cardiac ryanodine receptor (RyR2)-mediated Ca2+ release. CaM mutations associated with arrhythmias and sudden cardiac death have been shown to diminish CaM-dependent inhibition of RyR2, but the underlying mechanisms are not well understood. Nearly all arrhythmogenic CaM mutations identified are located in the C-domain of CaM and exert marked effects on Ca2+ binding to CaM and on the CaM C-domain interaction with the CaM-binding domain 2 (CaMBD2) in RyR2. Interestingly, the arrhythmogenic N-domain mutation CaM-N54I has little or no effect on Ca2+ binding to CaM or the CaM C-domain-RyR2 CaMBD2 interaction, unlike all CaM C-domain mutations. This suggests that CaM-N54I may diminish CaM-dependent RyR2 inhibition by affecting CaM N-domain interactions with RyR2 CaMBDs other than CaMBD2. To explore this possibility, we assessed the effects of deleting each of the four known CaMBDs in RyR2 (CaMBD1a, -1b, -2, or -3) on the CaM-dependent inhibition of RyR2-mediated Ca2+ release in HEK293 cells. We found that removing CaMBD1a, CaMBD1b, or CaMBD3 did not alter the effects of CaM-N54I or CaM-WT on RyR2 inhibition. On the other hand, deleting RyR2-CaMBD2 abolished the effects of both CaM-N54I and CaM-WT. Our results support that CaM-N54I causes aberrant RyR2 regulation via an uncharacterized CaMBD or less likely CaMBD2, and that RyR2 CaMBD2 is required for the actions of both N- and C-domain CaM mutations. Moreover, our results show that CaMBD1a is central to RyR2 regulation, but CaMBD1a, CaMBD1b, and CaMBD3 are not required for CaM-dependent inhibition of RyR2 in HEK293 cells.
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Affiliation(s)
- Mads T Søndergaard
- Department of Chemistry and Bioscience, Aalborg University, Denmark.,Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, AB, Canada
| | - Yingjie Liu
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, AB, Canada
| | - Wenting Guo
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, AB, Canada
| | - Jinhong Wei
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, AB, Canada
| | - Ruiwu Wang
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, AB, Canada
| | - Malene Brohus
- Department of Chemistry and Bioscience, Aalborg University, Denmark
| | | | - S R Wayne Chen
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, AB, Canada
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Wang Q, Groenendyk J, Paskevicius T, Qin W, Kor KC, Liu Y, Hiess F, Knollmann BC, Chen SRW, Tang J, Chen XZ, Agellon LB, Michalak M. Two pools of IRE1α in cardiac and skeletal muscle cells. FASEB J 2019; 33:8892-8904. [PMID: 31051095 PMCID: PMC6662970 DOI: 10.1096/fj.201802626r] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 04/08/2019] [Indexed: 12/23/2022]
Abstract
The endoplasmic reticulum (ER) plays a central role in cellular stress responses via mobilization of ER stress coping responses, such as the unfolded protein response (UPR). The inositol-requiring 1α (IRE1α) is an ER stress sensor and component of the UPR. Muscle cells also have a well-developed and highly subspecialized membrane network of smooth ER called the sarcoplasmic reticulum (SR) surrounding myofibrils and specialized for Ca2+ storage, release, and uptake to control muscle excitation-contraction coupling. Here, we describe 2 distinct pools of IRE1α in cardiac and skeletal muscle cells, one localized at the perinuclear ER and the other at the junctional SR. We discovered that, at the junctional SR, calsequestrin binds to the ER luminal domain of IRE1α, inhibiting its dimerization. This novel interaction of IRE1α with calsequestrin, one of the highly abundant Ca2+ handling proteins at the junctional SR, provides new insights into the regulation of stress coping responses in muscle cells.-Wang, Q., Groenendyk, J., Paskevicius, T., Qin, W., Kor, K. C., Liu, Y., Hiess, F., Knollmann, B. C., Chen, S. R. W., Tang, J., Chen, X.-Z., Agellon, L. B., Michalak, M. Two pools of IRE1α in cardiac and skeletal muscle cells.
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Affiliation(s)
- Qian Wang
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Jody Groenendyk
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | | | - Wenying Qin
- National “111” Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, China
| | - Kaylen C. Kor
- Division of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Yingjie Liu
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Florian Hiess
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Bjorn C. Knollmann
- Division of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - S. R. Wayne Chen
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Jingfeng Tang
- National “111” Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, China
| | - Xing-Zhen Chen
- National “111” Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, China
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada; and
| | - Luis B. Agellon
- School of Human Nutrition, McGill University, Ste. Anne de Bellevue, Quebec, Canada
| | - Marek Michalak
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
- National “111” Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, China
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Søndergaard MT, Liu Y, Brohus M, Guo W, Nani A, Carvajal C, Fill M, Overgaard MT, Chen SRW. Diminished inhibition and facilitated activation of RyR2-mediated Ca 2+ release is a common defect of arrhythmogenic calmodulin mutations. FEBS J 2019; 286:4554-4578. [PMID: 31230402 DOI: 10.1111/febs.14969] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 04/23/2019] [Accepted: 06/20/2019] [Indexed: 02/06/2023]
Abstract
A number of calmodulin (CaM) mutations cause severe cardiac arrhythmias, but their arrhythmogenic mechanisms are unclear. While some of the arrhythmogenic CaM mutations have been shown to impair CaM-dependent inhibition of intracellular Ca2+ release through the ryanodine receptor type 2 (RyR2), the impact of a majority of these mutations on RyR2 function is unknown. Here, we investigated the effect of 14 arrhythmogenic CaM mutations on the CaM-dependent RyR2 inhibition. We found that all the arrhythmogenic CaM mutations tested diminished CaM-dependent inhibition of RyR2-mediated Ca2+ release and increased store-overload induced Ca2+ release (SOICR) in HEK293 cells. Moreover, all the arrhythmogenic CaM mutations tested either failed to inhibit or even promoted RyR2-mediated Ca2+ release in permeabilized HEK293 cells with elevated cytosolic Ca2+ , which was markedly different from the inhibitory action of CaM wild-type. The CaM mutations also altered the Ca2+ -dependency of CaM binding to the RyR2 CaM-binding domain. These results demonstrate that diminished inhibition, and even facilitated activation, of RyR2-mediated Ca2+ release is a common defect of arrhythmogenic CaM mutations.
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Affiliation(s)
- Mads T Søndergaard
- Department of Chemistry and Bioscience, Aalborg University, Denmark.,Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, Alberta, Canada
| | - Yingjie Liu
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, Alberta, Canada
| | - Malene Brohus
- Department of Chemistry and Bioscience, Aalborg University, Denmark
| | - Wenting Guo
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, Alberta, Canada
| | - Alma Nani
- Department of Molecular Biophysics and Physiology, Rush University Medical Center, Chicago, IL, USA
| | - Catherine Carvajal
- Department of Molecular Biophysics and Physiology, Rush University Medical Center, Chicago, IL, USA
| | - Michael Fill
- Department of Molecular Biophysics and Physiology, Rush University Medical Center, Chicago, IL, USA
| | | | - S R Wayne Chen
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, Department of Biochemistry and Molecular Biology, University of Calgary, Alberta, Canada.,Department of Molecular Biophysics and Physiology, Rush University Medical Center, Chicago, IL, USA
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Hiess F, Detampel P, Nolla-Colomer C, Vallmitjana A, Ganguly A, Amrein M, Ter Keurs HEDJ, Benítez R, Hove-Madsen L, Chen SRW. Dynamic and Irregular Distribution of RyR2 Clusters in the Periphery of Live Ventricular Myocytes. Biophys J 2019; 114:343-354. [PMID: 29401432 DOI: 10.1016/j.bpj.2017.11.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 10/01/2017] [Accepted: 11/03/2017] [Indexed: 10/18/2022] Open
Abstract
Cardiac ryanodine receptors (RyR2s) are Ca2+ release channels clustering in the sarcoplasmic reticulum membrane. These clusters are believed to be the elementary units of Ca2+ release. The distribution of these Ca2+ release units plays a critical role in determining the spatio-temporal profile and stability of sarcoplasmic reticulum Ca2+ release. RyR2 clusters located in the interior of cardiomyocytes are arranged in highly ordered arrays. However, little is known about the distribution and function of RyR2 clusters in the periphery of cardiomyocytes. Here, we used a knock-in mouse model expressing a green fluorescence protein (GFP)-tagged RyR2 to localize RyR2 clusters in live ventricular myocytes by virtue of their GFP fluorescence. Confocal imaging and total internal reflection fluorescence microscopy was employed to determine and compare the distribution of GFP-RyR2 in the interior and periphery of isolated live ventricular myocytes and in intact hearts. We found tightly ordered arrays of GFP-RyR2 clusters in the interior, as previously described. In contrast, irregular distribution of GFP-RyR2 clusters was observed in the periphery. Time-lapse total internal reflection fluorescence imaging revealed dynamic movements of GFP-RyR2 clusters in the periphery, which were affected by external Ca2+ and RyR2 activator (caffeine) and inhibitor (tetracaine), but little detectable movement of GFP-RyR2 clusters in the interior. Furthermore, simultaneous Ca2+- and GFP-imaging demonstrated that peripheral RyR2 clusters with an irregular distribution pattern are functional with a Ca2+ release profile similar to that in the interior. These results indicate that the distribution of RyR2 clusters in the periphery of live ventricular myocytes is irregular and dynamic, which is different from that of RyR2 clusters in the interior.
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Affiliation(s)
- Florian Hiess
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Pascal Detampel
- Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland
| | - Carme Nolla-Colomer
- Automatic Control Department, Universitat Politècnica de Catalunya-Barcelona Tech, Barcelona, Spain
| | - Alex Vallmitjana
- Automatic Control Department, Universitat Politècnica de Catalunya-Barcelona Tech, Barcelona, Spain
| | - Anutosh Ganguly
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Matthias Amrein
- Department of Biology and Anatomy, University of Calgary, Calgary, Alberta, Canada
| | - Henk E D J Ter Keurs
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Raul Benítez
- Automatic Control Department, Universitat Politècnica de Catalunya-Barcelona Tech, Barcelona, Spain
| | - Leif Hove-Madsen
- Biomedical Research Institute Barcelona CSIC-IIBB, Sant Pau, Hospital de Sant Pau, Barcelona, Spain
| | - S R Wayne Chen
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.
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Gonano LA, Sepúlveda M, Morell M, Toteff T, Racioppi MF, Lascano E, Negroni J, Fernández Ruocco MJ, Medei E, Neiman G, Miriuka SG, Back TG, Chen SRW, Mattiazzi A, Vila Petroff M. Non-β-Blocking Carvedilol Analog, VK-II-86, Prevents Ouabain-Induced Cardiotoxicity. Circ J 2018; 83:41-51. [DOI: 10.1253/circj.cj-18-0247] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Luis A. Gonano
- Centro de Investigaciones Cardiovasculares, CONICET La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata
| | - Marisa Sepúlveda
- Centro de Investigaciones Cardiovasculares, CONICET La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata
| | - Malena Morell
- Centro de Investigaciones Cardiovasculares, CONICET La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata
| | - Tamara Toteff
- Centro de Investigaciones Cardiovasculares, CONICET La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata
| | - María Florencia Racioppi
- Centro de Investigaciones Cardiovasculares, CONICET La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata
| | - Elena Lascano
- Instituto de Medicina Translacional, Transplante y Bioingeniería, Universidad Favaloro, CONICET
| | - Jorge Negroni
- Instituto de Medicina Translacional, Transplante y Bioingeniería, Universidad Favaloro, CONICET
| | - María Julieta Fernández Ruocco
- Centro de Investigaciones Cardiovasculares, CONICET La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro
| | - Emiliano Medei
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro
| | | | | | | | - S. R. Wayne Chen
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary
| | - Alicia Mattiazzi
- Centro de Investigaciones Cardiovasculares, CONICET La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata
| | - Martin Vila Petroff
- Centro de Investigaciones Cardiovasculares, CONICET La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata
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Lieve KVV, Verhagen JMA, Wei J, Bos JM, van der Werf C, Rosés I Noguer F, Mancini GMS, Guo W, Wang R, van den Heuvel F, Frohn-Mulder IME, Shimizu W, Nogami A, Horigome H, Roberts JD, Leenhardt A, Crijns HJG, Blank AC, Aiba T, Wiesfeld ACP, Blom NA, Sumitomo N, Till J, Ackerman MJ, Chen SRW, van de Laar IMBH, Wilde AAM. Linking the heart and the brain: Neurodevelopmental disorders in patients with catecholaminergic polymorphic ventricular tachycardia. Heart Rhythm 2018; 16:220-228. [PMID: 30170228 DOI: 10.1016/j.hrthm.2018.08.025] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Indexed: 11/25/2022]
Abstract
BACKGROUND Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an uncommon inherited arrhythmia disorder characterized by adrenergically evoked ventricular arrhythmias. Mutations in the cardiac calcium release channel/ryanodine receptor gene (RYR2) are identified in the majority of patients with CPVT. RyR2 is also the major RyR isoform expressed in the brain. OBJECTIVE The purpose of this study was to estimate the prevalence of intellectual disability (ID) and other neurodevelopmental disorders (NDDs) in RYR2-associated CPVT (CPVT1) and to study the characteristics of these patients. METHODS We reviewed the medical records of all CPVT1 patients from 12 international centers and analyzed the characteristics of all CPVT1 patients with concomitant NDDs. We functionally characterized the mutations to assess their response to caffeine activation. We did not correct for potential confounders. RESULTS Among 421 CPVT1 patients, we identified 34 patients with ID (8%; 95% confidence interval 6%-11%). Median age at diagnosis was 9.3 years (interquartile range 7.0-14.5). Parents for 24 of 34 patients were available for genetic testing, and 13 of 24 (54%) had a de novo mutation. Severity of ID ranged from mild to severe and was accompanied by other NDDs in 9 patients (26%). Functionally, the ID-associated mutations showed a markedly enhanced response of RyR2 to activation by caffeine. Seventeen patients (50%) also had supraventricular arrhythmias. During median follow-up of 8.4 years (interquartile range 1.8-12.4), 15 patients (45%) experienced an arrhythmic event despite adequate therapy. CONCLUSION Our study indicates that ID is more prevalent among CPVT1 patients (8%) than in the general population (1%-3%). This subgroup of CPVT1 patients reveals a malignant cardiac phenotype with marked supraventricular and ventricular arrhythmias.
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Affiliation(s)
- Krystien V V Lieve
- AMC Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands
| | - Judith M A Verhagen
- Department of Clinical Genetics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Jinhong Wei
- The Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - J Martijn Bos
- Department of Cardiovascular Diseases, Division of Heart Rhythm Services, Mayo Clinic, Rochester, Minnesota, Department of Pediatric and Adolescent Medicine, Division of Pediatric Cardiology, Mayo Clinic, Rochester, Minnesota, and Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota
| | - Christian van der Werf
- AMC Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands
| | | | - Grazia M S Mancini
- Department of Clinical Genetics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Wenting Guo
- The Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Ruiwu Wang
- The Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Freek van den Heuvel
- Department of Pediatric Cardiology, Beatrix Children's Hospital, University Medical Center Groningen, Groningen, The Netherlands
| | - Ingrid M E Frohn-Mulder
- Department of Pediatric Cardiology, Sophia Children's Hospital, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Wataru Shimizu
- Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan; Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Akihiko Nogami
- Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Hitoshi Horigome
- Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Jason D Roberts
- Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Western University, London, Ontario, Canada
| | - Antoine Leenhardt
- CNMR Maladies Cardiaques Héréditaires Rares, Hôpital Bichat, Université Paris Diderot, Sorbonne Paris Cité, Paris, France, and AP-HP, Service de Cardiologie, Hôpital Bichat, Paris, France
| | - Harry J G Crijns
- Department of Cardiology, CARIM School for Cardiovascular Diseases, Faculty of Health, Medicine, and Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - Andreas C Blank
- Department of Pediatric Cardiology, Wilhelmina Children's Hospital, University Medical Center, Utrecht, The Netherlands
| | - Takeshi Aiba
- Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Ans C P Wiesfeld
- Department of Cardiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Nico A Blom
- AMC Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands; Department of Pediatric Cardiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Naokata Sumitomo
- Department of Pediatric Cardiology, Saitama Medical University International Medical Center, Saitama, Japan
| | - Jan Till
- Department of Cardiology, Royal Brompton Hospital, London, United Kingdom
| | - Michael J Ackerman
- Department of Cardiovascular Diseases, Division of Heart Rhythm Services, Mayo Clinic, Rochester, Minnesota, Department of Pediatric and Adolescent Medicine, Division of Pediatric Cardiology, Mayo Clinic, Rochester, Minnesota, and Department of Molecular Pharmacology & Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota
| | - S R Wayne Chen
- The Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Ingrid M B H van de Laar
- Department of Clinical Genetics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Arthur A M Wilde
- AMC Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Amsterdam, The Netherlands; Princess Al-Jawhara Al-Brahim Centre of Excellence in Research of Hereditary Disorders, Jeddah, Kingdom of Saudi Arabia.
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Sun B, Wei J, Zhong X, Guo W, Yao J, Wang R, Vallmitjana A, Benitez R, Hove-Madsen L, Chen SRW. The cardiac ryanodine receptor, but not sarcoplasmic reticulum Ca 2+-ATPase, is a major determinant of Ca 2+ alternans in intact mouse hearts. J Biol Chem 2018; 293:13650-13661. [PMID: 29986885 DOI: 10.1074/jbc.ra118.003760] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 07/06/2018] [Indexed: 11/06/2022] Open
Abstract
Sarcoplasmic reticulum (SR) Ca2+ cycling is governed by the cardiac ryanodine receptor (RyR2) and SR Ca2+-ATPase (SERCA2a). Abnormal SR Ca2+ cycling is thought to be the primary cause of Ca2+ alternans that can elicit ventricular arrhythmias and sudden cardiac arrest. Although alterations in either RyR2 or SERCA2a function are expected to affect SR Ca2+ cycling, whether and to what extent altered RyR2 or SERCA2a function affects Ca2+ alternans is unclear. Here, we employed a gain-of-function RyR2 variant (R4496C) and the phospholamban-knockout (PLB-KO) mouse model to assess the effect of genetically enhanced RyR2 or SERCA2a function on Ca2+ alternans. Confocal Ca2+ imaging revealed that RyR2-R4496C shortened SR Ca2+ release refractoriness and markedly suppressed rapid pacing-induced Ca2+ alternans. Interestingly, despite enhancing RyR2 function, intact RyR2-R4496C hearts exhibited no detectable spontaneous SR Ca2+ release events during pacing. Unlike for RyR2, enhancing SERCA2a function by ablating PLB exerted a relatively minor effect on Ca2+ alternans in intact hearts expressing RyR2 WT or a loss-of-function RyR2 variant, E4872Q, that promotes Ca2+ alternans. Furthermore, partial SERCA2a inhibition with 3 μm 2,5-di-tert-butylhydroquinone (tBHQ) also had little impact on Ca2+ alternans, whereas strong SERCA2a inhibition with 10 μm tBHQ markedly reduced the amplitude of Ca2+ transients and suppressed Ca2+ alternans in intact hearts. Our results demonstrate that enhanced RyR2 function suppresses Ca2+ alternans in the absence of spontaneous Ca2+ release and that RyR2, but not SERCA2a, is a key determinant of Ca2+ alternans in intact working hearts, making RyR2 an important therapeutic target for cardiac alternans.
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Affiliation(s)
- Bo Sun
- From the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Jinhong Wei
- From the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Xiaowei Zhong
- From the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Wenting Guo
- From the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Jinjing Yao
- From the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Ruiwu Wang
- From the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Alexander Vallmitjana
- the Department of Automatic Control, Universitat Politècnica de Catalunya, Barcelona 08034, Spain, and
| | - Raul Benitez
- the Department of Automatic Control, Universitat Politècnica de Catalunya, Barcelona 08034, Spain, and
| | - Leif Hove-Madsen
- the Biomedical Research Institute of Barcelona (IIBB), CSIC, Sant Pau, Hospital de Sant Pau, Barcelona 08025, Spain
| | - S R Wayne Chen
- From the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada,
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Miranda WE, Ngo VA, Wang R, Zhang L, Chen SRW, Noskov SY. Molecular Mechanism of Conductance Enhancement in Narrow Cation-Selective Membrane Channels. J Phys Chem Lett 2018; 9:3497-3502. [PMID: 29886737 DOI: 10.1021/acs.jpclett.8b01005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Membrane proteins known as ryanodine receptors (RyRs) display large conductance of ∼1 nS and nearly ideal charge selectivity. Both properties are inversely correlated in other large-conductance but nonselective biological nanopores (i.e., α-hemolysin) used as industrial biosensors. Although recent cryo-electron microscopy structures of RyR2 show similarities to K+- and Na+-selective channels, it remains unclear whether similar ion conduction mechanisms occur in RyR2. Here, we combine microseconds of all-atom molecular dynamics (MD) simulations with mutagenesis and electrophysiology experiments to investigate large K+ conductance and charge selectivity (cation vs anion) in an open-state structure of RyR2. Our results show that a water-mediated knock-on mechanism enhances the cation permeation. The polar Q4863 ring may function as a confinement zone amplifying charge selectivity, while the cytoplasmic vestibule can contribute to the efficiency of the cation attraction. We also provide direct evidence that the rings of acidic residues at the channel vestibules are critical for both conductance and charge discrimination in RyRs.
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Affiliation(s)
- Williams E Miranda
- Centre for Molecular Simulations and Department of Biological Sciences , University of Calgary , Alberta T2N 1N4 , Canada
| | - Van A Ngo
- Centre for Molecular Simulations and Department of Biological Sciences , University of Calgary , Alberta T2N 1N4 , Canada
| | - Ruiwu Wang
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta , University of Calgary , Alberta T2N 1N4 , Canada
| | - Lin Zhang
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta , University of Calgary , Alberta T2N 1N4 , Canada
| | - S R Wayne Chen
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta , University of Calgary , Alberta T2N 1N4 , Canada
| | - Sergei Yu Noskov
- Centre for Molecular Simulations and Department of Biological Sciences , University of Calgary , Alberta T2N 1N4 , Canada
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Liu Y, Wei J, Wong King Yuen SM, Sun B, Tang Y, Wang R, Van Petegem F, Chen SRW. CPVT-associated cardiac ryanodine receptor mutation G357S with reduced penetrance impairs Ca2+ release termination and diminishes protein expression. PLoS One 2017; 12:e0184177. [PMID: 28961276 PMCID: PMC5621672 DOI: 10.1371/journal.pone.0184177] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 08/18/2017] [Indexed: 11/18/2022] Open
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is one of the most lethal inherited cardiac arrhythmias mostly linked to cardiac ryanodine receptor (RyR2) mutations with high disease penetrance. Interestingly, a novel RyR2 mutation G357S discovered in a large family of more than 1400 individuals has reduced penetrance. The molecular basis for the incomplete disease penetrance in this family is unknown. To gain insights into the variable disease expression in this family, we determined the impact of the G357S mutation on RyR2 function and expression. We assessed spontaneous Ca2+ release in HEK293 cells expressing RyR2 wildtype and the G357S mutant during store Ca2+ overload, also known as store overload induced Ca2+ release (SOICR). We found that the G357S mutation reduced the percentage of RyR2-expressing cells that showed SOICR. However, in cells that displayed SOICR, G357S reduced the thresholds for the activation and termination of SOICR. Furthermore, G357S decreased the thermal stability of the N-terminal domain of RyR2, and markedly reduced the protein expression of the full-length RyR2. On the other hand, the G357S mutation did not alter the Ca2+ activation of [3H]ryanodine binding or the Ca2+ induced release of Ca2+ from the intracellular stores in HEK293 cells. These data indicate that the CPVT-associated G357S mutation enhances the arrhythmogenic SOICR and reduces RyR2 protein expression, which may be attributable to the incomplete penetrance of CPVT in this family.
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Affiliation(s)
- Yingjie Liu
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Jinhong Wei
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Siobhan M Wong King Yuen
- Department of Biochemistry and Molecular Biology, University of British Columbia, 2350 Health Sciences Mall, Vancouver, Canada
| | - Bo Sun
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Yijun Tang
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Ruiwu Wang
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, University of British Columbia, 2350 Health Sciences Mall, Vancouver, Canada
| | - S R Wayne Chen
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
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38
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Jones PP, Guo W, Chen SRW. Control of cardiac ryanodine receptor by sarcoplasmic reticulum luminal Ca 2. J Gen Physiol 2017; 149:867-875. [PMID: 28798281 PMCID: PMC5583710 DOI: 10.1085/jgp.201711805] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 06/25/2017] [Accepted: 07/18/2017] [Indexed: 12/22/2022] Open
Abstract
Jones et al. propose that SR luminal Ca2+ regulates RyR2 activity via a luminal Ca2+ sensor distinct from the cytosolic Ca2+ sensor.
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Affiliation(s)
- Peter P Jones
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, Otago, New Zealand .,HeartOtago, University of Otago, Dunedin, Otago, New Zealand
| | - Wenting Guo
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - S R Wayne Chen
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
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39
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Kim DY, Zhang FX, Nakanishi ST, Mettler T, Cho IH, Ahn Y, Hiess F, Chen L, Sullivan PG, Chen SRW, Zamponi GW, Rho JM. Carisbamate blockade of T-type voltage-gated calcium channels. Epilepsia 2017; 58:617-626. [PMID: 28230232 DOI: 10.1111/epi.13710] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/25/2017] [Indexed: 01/23/2023]
Abstract
OBJECTIVES Carisbamate (CRS) is a novel monocarbamate compound that possesses antiseizure and neuroprotective properties. However, the mechanisms underlying these actions remain unclear. Here, we tested both direct and indirect effects of CRS on several cellular systems that regulate intracellular calcium concentration [Ca2+ ]i . METHODS We used a combination of cellular electrophysiologic techniques, as well as cell viability, Store Overload-Induced Calcium Release (SOICR), and mitochondrial functional assays to determine whether CRS might affect [Ca2+ ]i levels through actions on the endoplasmic reticulum (ER), mitochondria, and/or T-type voltage-gated Ca2+ channels. RESULTS In CA3 pyramidal neurons, kainic acid induced significant elevations in [Ca2+ ]i and long-lasting neuronal hyperexcitability, both of which were reversed in a dose-dependent manner by CRS. Similarly, CRS suppressed spontaneous rhythmic epileptiform activity in hippocampal slices exposed to zero-Mg2+ or 4-aminopyridine. Treatment with CRS also protected murine hippocampal HT-22 cells against excitotoxic injury with glutamate, and this was accompanied by a reduction in [Ca2+ ]i . Neither kainic acid nor CRS alone altered the mitochondrial membrane potential (ΔΨ) in intact, acutely isolated mitochondria. In addition, CRS did not affect mitochondrial respiratory chain activity, Ca2+ -induced mitochondrial permeability transition, and Ca2+ release from the ER. However, CRS significantly decreased Ca2+ flux in human embryonic kidney tsA-201 cells transfected with Cav 3.1 (voltage-dependent T-type Ca2+ ) channels. SIGNIFICANCE Our data indicate that the neuroprotective and antiseizure activity of CRS likely results in part from decreased [Ca2+ ]i accumulation through blockade of T-type Ca2+ channels.
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Affiliation(s)
- Do Young Kim
- Departments of Neurology and Neurobiology, Barrow Neurological Institute, St. Joseph's Hospital & Medical Center, Phoenix, Arizona, U.S.A
| | - Fang-Xiong Zhang
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Stan T Nakanishi
- Department of Biology, University of Hawaii at Hilo, Hilo, Hawaii, U.S.A
| | - Timothy Mettler
- Departments of Neurology and Neurobiology, Barrow Neurological Institute, St. Joseph's Hospital & Medical Center, Phoenix, Arizona, U.S.A
| | - Ik-Hyun Cho
- Departments of Neurology and Neurobiology, Barrow Neurological Institute, St. Joseph's Hospital & Medical Center, Phoenix, Arizona, U.S.A
| | - Younghee Ahn
- Department of Pediatrics, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Florian Hiess
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Lina Chen
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Patrick G Sullivan
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky, U.S.A
| | - S R Wayne Chen
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Gerald W Zamponi
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Jong M Rho
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Department of Pediatrics, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada.,Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
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40
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Søndergaard MT, Liu Y, Larsen KT, Nani A, Tian X, Holt C, Wang R, Wimmer R, Van Petegem F, Fill M, Chen SRW, Overgaard MT. The Arrhythmogenic Calmodulin p.Phe142Leu Mutation Impairs C-domain Ca2+ Binding but Not Calmodulin-dependent Inhibition of the Cardiac Ryanodine Receptor. J Biol Chem 2016; 292:1385-1395. [PMID: 27927985 PMCID: PMC5270481 DOI: 10.1074/jbc.m116.766253] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 11/30/2016] [Indexed: 11/29/2022] Open
Abstract
A number of point mutations in the intracellular Ca2+-sensing protein calmodulin (CaM) are arrhythmogenic, yet their underlying mechanisms are not clear. These mutations generally decrease Ca2+ binding to CaM and impair inhibition of CaM-regulated Ca2+ channels like the cardiac Ca2+ release channel (ryanodine receptor, RyR2), and it appears that attenuated CaM Ca2+ binding correlates with impaired CaM-dependent RyR2 inhibition. Here, we investigated the RyR2 inhibitory action of the CaM p.Phe142Leu mutation (F142L; numbered including the start-Met), which markedly reduces CaM Ca2+ binding. Surprisingly, CaM-F142L had little to no aberrant effect on RyR2-mediated store overload-induced Ca2+ release in HEK293 cells compared with CaM-WT. Furthermore, CaM-F142L enhanced CaM-dependent RyR2 inhibition at the single channel level compared with CaM-WT. This is in stark contrast to the actions of arrhythmogenic CaM mutations N54I, D96V, N98S, and D130G, which all diminish CaM-dependent RyR2 inhibition. Thermodynamic analysis showed that apoCaM-F142L converts an endothermal interaction between CaM and the CaM-binding domain (CaMBD) of RyR2 into an exothermal one. Moreover, NMR spectra revealed that the CaM-F142L-CaMBD interaction is structurally different from that of CaM-WT at low Ca2+. These data indicate a distinct interaction between CaM-F142L and the RyR2 CaMBD, which may explain the stronger CaM-dependent RyR2 inhibition by CaM-F142L, despite its reduced Ca2+ binding. Collectively, these results add to our understanding of CaM-dependent regulation of RyR2 as well as the mechanistic effects of arrhythmogenic CaM mutations. The unique properties of the CaM-F142L mutation may provide novel clues on how to suppress excessive RyR2 Ca2+ release by manipulating the CaM-RyR2 interaction.
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Affiliation(s)
- Mads Toft Søndergaard
- From the Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg, Denmark.,the Libin Cardiovascular Institute of Alberta, the Department of Physiology and Pharmacology and the Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Yingjie Liu
- the Libin Cardiovascular Institute of Alberta, the Department of Physiology and Pharmacology and the Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Kamilla Taunsig Larsen
- From the Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg, Denmark
| | - Alma Nani
- the Department of Molecular Biophysics and Physiology, Rush University Medical Center, Chicago, Illinois 60612
| | - Xixi Tian
- the Libin Cardiovascular Institute of Alberta, the Department of Physiology and Pharmacology and the Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Christian Holt
- From the Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg, Denmark
| | - Ruiwu Wang
- the Libin Cardiovascular Institute of Alberta, the Department of Physiology and Pharmacology and the Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Reinhard Wimmer
- From the Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg, Denmark
| | - Filip Van Petegem
- the Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada, and
| | - Michael Fill
- the Department of Molecular Biophysics and Physiology, Rush University Medical Center, Chicago, Illinois 60612
| | - S R Wayne Chen
- the Libin Cardiovascular Institute of Alberta, the Department of Physiology and Pharmacology and the Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 1N4, Canada.,the Department of Molecular Biophysics and Physiology, Rush University Medical Center, Chicago, Illinois 60612
| | - Michael Toft Overgaard
- From the Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg, Denmark,
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41
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Lebeau P, Al-Hashimi A, Sood S, Lhoták Š, Yu P, Gyulay G, Paré G, Chen SRW, Trigatti B, Prat A, Seidah NG, Austin RC. Endoplasmic Reticulum Stress and Ca2+ Depletion Differentially Modulate the Sterol Regulatory Protein PCSK9 to Control Lipid Metabolism. J Biol Chem 2016; 292:1510-1523. [PMID: 27909053 DOI: 10.1074/jbc.m116.744235] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 11/08/2016] [Indexed: 12/13/2022] Open
Abstract
Accumulating evidence implicates endoplasmic reticulum (ER) stress as a mediator of impaired lipid metabolism, thereby contributing to fatty liver disease and atherosclerosis. Previous studies demonstrated that ER stress can activate the sterol regulatory element-binding protein-2 (SREBP2), an ER-localized transcription factor that directly up-regulates sterol regulatory genes, including PCSK9 Given that PCSK9 contributes to atherosclerosis by targeting low density lipoprotein (LDL) receptor (LDLR) degradation, this study investigates a novel mechanism by which ER stress plays a role in lipid metabolism by examining its ability to modulate PCSK9 expression. Herein, we demonstrate the existence of two independent effects of ER stress on PCSK9 expression and secretion. In cultured HuH7 and HepG2 cells, agents or conditions that cause ER Ca2+ depletion, including thapsigargin, induced SREBP2-dependent up-regulation of PCSK9 expression. In contrast, a significant reduction in the secreted form of PCSK9 protein was observed in the media from both thapsigargin- and tunicamycin (TM)-treated HuH7 cells, mouse primary hepatocytes, and in the plasma of TM-treated C57BL/6 mice. Furthermore, TM significantly increased hepatic LDLR expression and reduced plasma LDL concentrations in mice. Based on these findings, we propose a model in which ER Ca2+ depletion promotes the activation of SREBP2 and subsequent transcription of PCSK9. However, conditions that cause ER stress regardless of their ability to dysregulate ER Ca2+ inhibit PCSK9 secretion, thereby reducing PCSK9-mediated LDLR degradation and promoting LDLR-dependent hepatic cholesterol uptake. Taken together, our studies provide evidence that the retention of PCSK9 in the ER may serve as a potential strategy for lowering LDL cholesterol levels.
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Affiliation(s)
- Paul Lebeau
- From the Department of Medicine, Division of Nephrology, McMaster University and St. Joseph's Hamilton Healthcare and Hamilton Centre for Kidney Research, Hamilton, Ontario L8N 4A6
| | - Ali Al-Hashimi
- From the Department of Medicine, Division of Nephrology, McMaster University and St. Joseph's Hamilton Healthcare and Hamilton Centre for Kidney Research, Hamilton, Ontario L8N 4A6
| | - Sudesh Sood
- From the Department of Medicine, Division of Nephrology, McMaster University and St. Joseph's Hamilton Healthcare and Hamilton Centre for Kidney Research, Hamilton, Ontario L8N 4A6
| | - Šárka Lhoták
- From the Department of Medicine, Division of Nephrology, McMaster University and St. Joseph's Hamilton Healthcare and Hamilton Centre for Kidney Research, Hamilton, Ontario L8N 4A6
| | - Pei Yu
- the Thrombosis and Atherosclerosis Research Institute, Hamilton Health Sciences and McMaster University, Hamilton, Ontario L8L 2X2.,the Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8S 4L8
| | - Gabriel Gyulay
- From the Department of Medicine, Division of Nephrology, McMaster University and St. Joseph's Hamilton Healthcare and Hamilton Centre for Kidney Research, Hamilton, Ontario L8N 4A6
| | - Guillaume Paré
- the Population Health Research Institute and the Departments of Medicine, Epidemiology and Pathology, McMaster University, Hamilton, Ontario L8L 2X2
| | - S R Wayne Chen
- the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 2T9, and
| | - Bernardo Trigatti
- the Thrombosis and Atherosclerosis Research Institute, Hamilton Health Sciences and McMaster University, Hamilton, Ontario L8L 2X2.,the Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8S 4L8
| | - Annik Prat
- the Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, affiliated with the University of Montreal, Montreal, Quebec H2W 1R7, Canada
| | - Nabil G Seidah
- the Laboratory of Biochemical Neuroendocrinology, Clinical Research Institute of Montreal, affiliated with the University of Montreal, Montreal, Quebec H2W 1R7, Canada
| | - Richard C Austin
- From the Department of Medicine, Division of Nephrology, McMaster University and St. Joseph's Hamilton Healthcare and Hamilton Centre for Kidney Research, Hamilton, Ontario L8N 4A6, .,the Thrombosis and Atherosclerosis Research Institute, Hamilton Health Sciences and McMaster University, Hamilton, Ontario L8L 2X2
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42
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Sun B, Guo W, Tian X, Yao J, Zhang L, Wang R, Chen SRW. The Cytoplasmic Region of Inner Helix S6 Is an Important Determinant of Cardiac Ryanodine Receptor Channel Gating. J Biol Chem 2016; 291:26024-26034. [PMID: 27789712 DOI: 10.1074/jbc.m116.758821] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 10/18/2016] [Indexed: 11/06/2022] Open
Abstract
The ryanodine receptor (RyR) channel pore is formed by four S6 inner helices, with its intracellular gate located at the S6 helix bundle crossing region. The cytoplasmic region of the extended S6 helix is held by the U motif of the central domain and is thought to control the opening and closing of the S6 helix bundle. However, the functional significance of the S6 cytoplasmic region in channel gating is unknown. Here we assessed the role of the S6 cytoplasmic region in the function of cardiac RyR (RyR2) via structure-guided site-directed mutagenesis. We mutated each residue in the S6 cytoplasmic region of the mouse RyR2 (4876QQEQVKEDM4884) and characterized their functional impact. We found that mutations Q4876A, V4880A, K4881A, and M4884A, located mainly on one side of the S6 helix that faces the U motif, enhanced basal channel activity and the sensitivity to Ca2+ or caffeine activation, whereas mutations Q4877A, E4878A, Q4879A, and D4883A, located largely on the opposite side of S6, suppressed channel activity. Furthermore, V4880A, a cardiac arrhythmia-associated mutation, markedly enhanced the frequency of spontaneous openings and the sensitivity to cytosolic and luminal Ca2+ activation of single RyR2 channels. V4880A also increased the propensity and reduced the threshold for arrhythmogenic spontaneous Ca2+ release in HEK293 cells. Collectively, our data suggest that interactions between the cytoplasmic region of S6 and the U motif of RyR2 are important for stabilizing the closed state of the channel. Mutations in the S6/U motif domain interface likely destabilize the closed state of RyR2, resulting in enhanced basal channel activity and sensitivity to activation and increased propensity for spontaneous Ca2+ release and cardiac arrhythmias.
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Affiliation(s)
- Bo Sun
- From the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Wenting Guo
- From the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Xixi Tian
- From the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Jinjing Yao
- From the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Lin Zhang
- From the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Ruiwu Wang
- From the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - S R Wayne Chen
- From the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
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43
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Xiao Z, Guo W, Sun B, Hunt DJ, Wei J, Liu Y, Wang Y, Wang R, Jones PP, Back TG, Chen SRW. Enhanced Cytosolic Ca2+ Activation Underlies a Common Defect of Central Domain Cardiac Ryanodine Receptor Mutations Linked to Arrhythmias. J Biol Chem 2016; 291:24528-24537. [PMID: 27733687 DOI: 10.1074/jbc.m116.756528] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/02/2016] [Indexed: 01/21/2023] Open
Abstract
Recent three-dimensional structural studies reveal that the central domain of ryanodine receptor (RyR) serves as a transducer that converts long-range conformational changes into the gating of the channel pore. Interestingly, the central domain encompasses one of the mutation hotspots (corresponding to amino acid residues 3778-4201) that contains a number of cardiac RyR (RyR2) mutations associated with catecholaminergic polymorphic ventricular tachycardia (CPVT) and atrial fibrillation (AF). However, the functional consequences of these central domain RyR2 mutations are not well understood. To gain insights into the impact of the mutation and the role of the central domain in channel function, we generated and characterized eight disease-associated RyR2 mutations in the central domain. We found that all eight central domain RyR2 mutations enhanced the Ca2+-dependent activation of [3H]ryanodine binding, increased cytosolic Ca2+-induced fractional Ca2+ release, and reduced the activation and termination thresholds for spontaneous Ca2+ release in HEK293 cells. We also showed that racemic carvedilol and the non-beta-blocking carvedilol enantiomer, (R)-carvedilol, suppressed spontaneous Ca2+ oscillations in HEK293 cells expressing the central domain RyR2 mutations associated with CPVT and AF. These data indicate that the central domain is an important determinant of cytosolic Ca2+ activation of RyR2. These results also suggest that altered cytosolic Ca2+ activation of RyR2 represents a common defect of RyR2 mutations associated with CPVT and AF, which could potentially be suppressed by carvedilol or (R)-carvedilol.
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Affiliation(s)
- Zhichao Xiao
- From the the Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Wenting Guo
- From the the Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Bo Sun
- From the the Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Donald J Hunt
- From the the Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Jinhong Wei
- From the the Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Yingjie Liu
- From the the Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Yundi Wang
- From the the Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Ruiwu Wang
- From the the Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Peter P Jones
- the Department of Physiology, Otago School of Medical Sciences and HeartOtago, University of Otago, Dunedin 9054, New Zealand, and
| | - Thomas G Back
- the Department of Chemistry, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - S R Wayne Chen
- From the the Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta T2N 4N1, Canada,.
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Peng W, Shen H, Wu J, Guo W, Pan X, Wang R, Chen SRW, Yan N. Structural basis for the gating mechanism of the type 2 ryanodine receptor RyR2. Science 2016; 354:science.aah5324. [PMID: 27708056 DOI: 10.1126/science.aah5324] [Citation(s) in RCA: 187] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 09/14/2016] [Indexed: 01/10/2023]
Abstract
RyR2 is a high-conductance intracellular calcium (Ca2+) channel that controls the release of Ca2+ from the sarco(endo)plasmic reticulum of a variety of cells. Here, we report the structures of RyR2 from porcine heart in both the open and closed states at near-atomic resolutions determined using single-particle electron cryomicroscopy. Structural comparison reveals a breathing motion of the overall cytoplasmic region resulted from the interdomain movements of amino-terminal domains (NTDs), Helical domains, and Handle domains, whereas almost no intradomain shifts are observed in these armadillo repeats-containing domains. Outward rotations of the Central domains, which integrate the conformational changes of the cytoplasmic region, lead to the dilation of the cytoplasmic gate through coupled motions. Our structural and mutational characterizations provide important insights into the gating and disease mechanism of RyRs.
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Affiliation(s)
- Wei Peng
- State Key Laboratory of Membrane Biology, Tsinghua University, Beijing 100084, China.,Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing 100084, China
| | - Huaizong Shen
- State Key Laboratory of Membrane Biology, Tsinghua University, Beijing 100084, China.,Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing 100084, China.,Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Jianping Wu
- State Key Laboratory of Membrane Biology, Tsinghua University, Beijing 100084, China.,Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing 100084, China.,Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
| | - Wenting Guo
- The Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada, T2N 4N1
| | - Xiaojing Pan
- State Key Laboratory of Membrane Biology, Tsinghua University, Beijing 100084, China.,Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing 100084, China
| | - Ruiwu Wang
- The Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada, T2N 4N1
| | - S R Wayne Chen
- The Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada, T2N 4N1.
| | - Nieng Yan
- State Key Laboratory of Membrane Biology, Tsinghua University, Beijing 100084, China. .,Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, Beijing 100084, China.,Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China
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45
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Bround MJ, Wambolt R, Cen H, Asghari P, Albu RF, Han J, McAfee D, Pourrier M, Scott NE, Bohunek L, Kulpa JE, Chen SRW, Fedida D, Brownsey RW, Borchers CH, Foster LJ, Mayor T, Moore EDW, Allard MF, Johnson JD. Cardiac Ryanodine Receptor (Ryr2)-mediated Calcium Signals Specifically Promote Glucose Oxidation via Pyruvate Dehydrogenase. J Biol Chem 2016; 291:23490-23505. [PMID: 27621312 DOI: 10.1074/jbc.m116.756973] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Indexed: 11/06/2022] Open
Abstract
Cardiac ryanodine receptor (Ryr2) Ca2+ release channels and cellular metabolism are both disrupted in heart disease. Recently, we demonstrated that total loss of Ryr2 leads to cardiomyocyte contractile dysfunction, arrhythmia, and reduced heart rate. Acute total Ryr2 ablation also impaired metabolism, but it was not clear whether this was a cause or consequence of heart failure. Previous in vitro studies revealed that Ca2+ flux into the mitochondria helps pace oxidative metabolism, but there is limited in vivo evidence supporting this concept. Here, we studied heart-specific, inducible Ryr2 haploinsufficient (cRyr2Δ50) mice with a stable 50% reduction in Ryr2 protein. This manipulation decreased the amplitude and frequency of cytosolic and mitochondrial Ca2+ signals in isolated cardiomyocytes, without changes in cardiomyocyte contraction. Remarkably, in the context of well preserved contractile function in perfused hearts, we observed decreased glucose oxidation, but not fat oxidation, with increased glycolysis. cRyr2Δ50 hearts exhibited hyperphosphorylation and inhibition of pyruvate dehydrogenase, the key Ca2+-sensitive gatekeeper to glucose oxidation. Metabolomic, proteomic, and transcriptomic analyses revealed additional functional networks associated with altered metabolism in this model. These results demonstrate that Ryr2 controls mitochondrial Ca2+ dynamics and plays a specific, critical role in promoting glucose oxidation in cardiomyocytes. Our findings indicate that partial RYR2 loss is sufficient to cause metabolic abnormalities seen in heart disease.
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Affiliation(s)
- Michael J Bround
- From the Cardiovascular Research Group, Life Sciences Institute and.,Departments of Cellular and Physiological Sciences
| | - Rich Wambolt
- From the Cardiovascular Research Group, Life Sciences Institute and.,the Department of Pathology and Laboratory Medicine, University of British Columbia and the Centre for Heart and Lung Innovation, St. Paul's Hospital, Vancouver, British Columbia V6Z 1Y6
| | - Haoning Cen
- From the Cardiovascular Research Group, Life Sciences Institute and.,Departments of Cellular and Physiological Sciences
| | - Parisa Asghari
- From the Cardiovascular Research Group, Life Sciences Institute and.,Departments of Cellular and Physiological Sciences
| | - Razvan F Albu
- Biochemistry and Molecular Biology, and.,the Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia V6T 1Z4
| | - Jun Han
- the University of Victoria-Genome British Columbia Proteomics Centre, Victoria, British Columbia V8Z 7X8, and
| | - Donald McAfee
- From the Cardiovascular Research Group, Life Sciences Institute and.,Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, British Columbia V6T 1Z3
| | - Marc Pourrier
- From the Cardiovascular Research Group, Life Sciences Institute and.,Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, British Columbia V6T 1Z3
| | - Nichollas E Scott
- Biochemistry and Molecular Biology, and.,the Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia V6T 1Z4
| | - Lubos Bohunek
- the Department of Pathology and Laboratory Medicine, University of British Columbia and the Centre for Heart and Lung Innovation, St. Paul's Hospital, Vancouver, British Columbia V6Z 1Y6
| | | | - S R Wayne Chen
- the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 2T9, Canada
| | - David Fedida
- From the Cardiovascular Research Group, Life Sciences Institute and.,Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, British Columbia V6T 1Z3
| | | | - Christoph H Borchers
- the University of Victoria-Genome British Columbia Proteomics Centre, Victoria, British Columbia V8Z 7X8, and
| | - Leonard J Foster
- Biochemistry and Molecular Biology, and.,the Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia V6T 1Z4
| | - Thibault Mayor
- Biochemistry and Molecular Biology, and.,the Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia V6T 1Z4
| | - Edwin D W Moore
- From the Cardiovascular Research Group, Life Sciences Institute and.,Departments of Cellular and Physiological Sciences
| | - Michael F Allard
- From the Cardiovascular Research Group, Life Sciences Institute and.,the Department of Pathology and Laboratory Medicine, University of British Columbia and the Centre for Heart and Lung Innovation, St. Paul's Hospital, Vancouver, British Columbia V6Z 1Y6
| | - James D Johnson
- From the Cardiovascular Research Group, Life Sciences Institute and .,Departments of Cellular and Physiological Sciences
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46
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Roston TM, Guo W, Krahn AD, Wang R, Van Petegem F, Sanatani S, Chen SRW, Lehman A. A novel RYR2 loss-of-function mutation (I4855M) is associated with left ventricular non-compaction and atypical catecholaminergic polymorphic ventricular tachycardia. J Electrocardiol 2016; 50:227-233. [PMID: 27646203 DOI: 10.1016/j.jelectrocard.2016.09.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Indexed: 12/21/2022]
Abstract
BACKGROUND Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an ion channelopathy usually caused by gain-of-function mutations ryanodine receptor type-2 (RyR2). Left ventricular non-compaction (LVNC) is an often genetic cardiomyopathy. A rare LVNC-CPVT overlap syndrome may be caused by exon 3 deletion in RyR2. We sought to characterize the phenotypic spectrum and molecular basis of a novel RyR2 mutation identified in a family with both conditions. METHODS Several members of an affected family underwent clinical and genetic assessments. A homology model of the RyR2 pore-region was generated to predict the location and potential impact of their RyR2 mutation. Ca2+-release assays were performed to characterize the functional impact of the RyR2 mutant expressed in HEK293 cells. RESULTS A multigenerational family presented with a history of sudden death and a phenotype of atypical CPVT and LVNC. Genetic testing revealed a RYR2 mutation (I4855M) in two affected individuals. A homology model of the RyR2 pore-region showed that the I4855M mutant reside is located in the highly conserved 'inner vestibule', a water-filled cavity. I4855M may interfere with Ca2+ permeation and affect interactions between RyR2 pore subunits, and is thus predicted in silico to be damaging. Expression and functional studies in HEK293 cells revealed that I4855M inhibited caffeine-induced Ca2+ release and exerted a dominant-negative impact on wild type RyR2. CONCLUSIONS This study identifies a potentially lethal overlapping syndrome of LVNC and atypical CPVT related to a novel RYR2 variant. Structural and functional studies suggest that this is a loss-of-function mutation, which exerts a dominant-negative effect on wild type RyR2.
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Affiliation(s)
- Thomas M Roston
- BC Inherited Arrhythmia Program, Vancouver, BC, Canada; Department of Medicine, University of British Columbia, Vancouver, BC, Canada; Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Wenting Guo
- Libin Cardiovascular Institute of Alberta, Department of Physiology & Pharmacology and Department Biochemistry & Molecular Biology, University of Calgary, Calgary, AB, Canada
| | - Andrew D Krahn
- BC Inherited Arrhythmia Program, Vancouver, BC, Canada; Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Ruiwu Wang
- Libin Cardiovascular Institute of Alberta, Department of Physiology & Pharmacology and Department Biochemistry & Molecular Biology, University of Calgary, Calgary, AB, Canada
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada
| | - Shubhayan Sanatani
- BC Inherited Arrhythmia Program, Vancouver, BC, Canada; Child and Family Research Institute, Vancouver, BC, Canada; Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
| | - S R Wayne Chen
- Libin Cardiovascular Institute of Alberta, Department of Physiology & Pharmacology and Department Biochemistry & Molecular Biology, University of Calgary, Calgary, AB, Canada
| | - Anna Lehman
- BC Inherited Arrhythmia Program, Vancouver, BC, Canada; Child and Family Research Institute, Vancouver, BC, Canada; Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada.
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47
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Abstract
Spontaneous Ca2+ waves, also termed store-overload-induced Ca2+ release (SOICR), in cardiac cells can trigger ventricular arrhythmias especially in failing hearts. SOICR occurs when RyRs are activated by an increase in sarcoplasmic reticulum (SR) luminal Ca2+. Carvedilol is one of the most effective drugs for preventing arrhythmias in patients with heart failure. Furthermore, carvedilol analogues with minimal β-blocking activity also block SOICR showing that SOICR-inhibiting activity is distinct from that for β-block. We show here that carvedilol is a potent inhibitor of cADPR-induced Ca2+ release in sea urchin egg homogenate. In addition, the carvedilol analog VK-II-86 with minimal β-blocking activity also suppresses cADPR-induced Ca2+ release. Carvedilol appeared to be a non-competitive antagonist of cADPR and could also suppress Ca2+ release by caffeine. These results are consistent with cADPR releasing Ca2+ in sea urchin eggs by sensitizing RyRs to Ca2+ involving a luminal Ca2+ activation mechanism. In addition to action on the RyR, we also observed inhibition of inositol 1,4,5-trisphosphate (IP3)-induced Ca2+ release by carvedilol suggesting a common mechanism between these evolutionarily related and conserved Ca2+ release channels.
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Affiliation(s)
- Anthony J Morgan
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
| | - Konstantina Bampali
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
| | - Margarida Ruas
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
| | - Cailley Factor
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
| | - Thomas G Back
- Department of Chemistry, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - S R Wayne Chen
- The Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Antony Galione
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
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48
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Guo W, Sun B, Xiao Z, Liu Y, Wang Y, Zhang L, Wang R, Chen SRW. The EF-hand Ca2+ Binding Domain Is Not Required for Cytosolic Ca2+ Activation of the Cardiac Ryanodine Receptor. J Biol Chem 2015; 291:2150-60. [PMID: 26663082 DOI: 10.1074/jbc.m115.693325] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Indexed: 11/06/2022] Open
Abstract
Activation of the cardiac ryanodine receptor (RyR2) by elevating cytosolic Ca(2+) is a central step in the process of Ca(2+)-induced Ca(2+) release, but the molecular basis of RyR2 activation by cytosolic Ca(2+) is poorly defined. It has been proposed recently that the putative Ca(2+) binding domain encompassing a pair of EF-hand motifs (EF1 and EF2) in the skeletal muscle ryanodine receptor (RyR1) functions as a Ca(2+) sensor that regulates the gating of RyR1. Although the role of the EF-hand domain in RyR1 function has been studied extensively, little is known about the functional significance of the corresponding EF-hand domain in RyR2. Here we investigate the effect of mutations in the EF-hand motifs on the Ca(2+) activation of RyR2. We found that mutations in the EF-hand motifs or deletion of the entire EF-hand domain did not affect the Ca(2+)-dependent activation of [(3)H]ryanodine binding or the cytosolic Ca(2+) activation of RyR2. On the other hand, deletion of the EF-hand domain markedly suppressed the luminal Ca(2+) activation of RyR2 and spontaneous Ca(2+) release in HEK293 cells during store Ca(2+) overload or store overload-induced Ca(2+) release (SOICR). Furthermore, mutations in the EF2 motif, but not EF1 motif, of RyR2 raised the threshold for SOICR termination, whereas deletion of the EF-hand domain of RyR2 increased both the activation and termination thresholds for SOICR. These results indicate that, although the EF-hand domain is not required for RyR2 activation by cytosolic Ca(2+), it plays an important role in luminal Ca(2+) activation and SOICR.
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Affiliation(s)
- Wenting Guo
- From the Libin Cardiovascular Institute of Alberta, Departments of Physiology and Pharmacology and Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Bo Sun
- From the Libin Cardiovascular Institute of Alberta, Departments of Physiology and Pharmacology and Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Zhichao Xiao
- From the Libin Cardiovascular Institute of Alberta, Departments of Physiology and Pharmacology and Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Yingjie Liu
- From the Libin Cardiovascular Institute of Alberta, Departments of Physiology and Pharmacology and Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Yundi Wang
- From the Libin Cardiovascular Institute of Alberta, Departments of Physiology and Pharmacology and Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Lin Zhang
- From the Libin Cardiovascular Institute of Alberta, Departments of Physiology and Pharmacology and Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Ruiwu Wang
- From the Libin Cardiovascular Institute of Alberta, Departments of Physiology and Pharmacology and Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - S R Wayne Chen
- From the Libin Cardiovascular Institute of Alberta, Departments of Physiology and Pharmacology and Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
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49
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Xiao Z, Guo W, Yuen SMWK, Wang R, Zhang L, Van Petegem F, Chen SRW. The H29D Mutation Does Not Enhance Cytosolic Ca2+ Activation of the Cardiac Ryanodine Receptor. PLoS One 2015; 10:e0139058. [PMID: 26405799 PMCID: PMC4583508 DOI: 10.1371/journal.pone.0139058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 09/07/2015] [Indexed: 11/25/2022] Open
Abstract
The N-terminal domain of the cardiac ryanodine receptor (RyR2) harbors a large number of naturally occurring mutations that are associated with stress-induced ventricular tachyarrhythmia and sudden death. Nearly all these disease-associated N-terminal mutations are located at domain interfaces or buried within domains. Mutations at these locations would alter domain-domain interactions or the stability/folding of domains. Recently, a novel RyR2 mutation H29D associated with ventricular arrhythmia at rest was found to enhance the activation of single RyR2 channels by diastolic levels of cytosolic Ca2+. Unlike other N-terminal disease-associated mutations, the H29D mutation is located on the surface of the N-terminal domain. It is unclear how this surface-exposed H29D mutation that does not appear to interact with other parts of the RyR2 structure could alter the intrinsic properties of the channel. Here we carried out detailed functional characterization of the RyR2-H29D mutant at the molecular and cellular levels. We found that the H29D mutation has no effect on the basal level or the Ca2+ dependent activation of [3H]ryanodine binding to RyR2, the cytosolic Ca2+ activation of single RyR2 channels, or the cytosolic Ca2+- or caffeine-induced Ca2+ release in HEK293 cells. In addition, the H29D mutation does not alter the propensity for spontaneous Ca2+ release or the thresholds for Ca2+ release activation or termination. Furthermore, the H29D mutation does not have significant impact on the thermal stability of the N-terminal region (residues 1–547) of RyR2. Collectively, our data show that the H29D mutation exerts little or no effect on the function of RyR2 or on the folding stability of the N-terminal region. Thus, our results provide no evidence that the H29D mutation enhances the cytosolic Ca2+ activation of RyR2.
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Affiliation(s)
- Zhichao Xiao
- Libin Cardiovascular Institute of Alberta, Department of Physiology & Pharmacology, University of Calgary, Calgary, Alberta, Canada T2N 4N1
- Libin Cardiovascular Institute of Alberta, Department of Biochemistry & Molecular Biology, University of Calgary, Calgary, Alberta, Canada T2N 4N1
| | - Wenting Guo
- Libin Cardiovascular Institute of Alberta, Department of Physiology & Pharmacology, University of Calgary, Calgary, Alberta, Canada T2N 4N1
- Libin Cardiovascular Institute of Alberta, Department of Biochemistry & Molecular Biology, University of Calgary, Calgary, Alberta, Canada T2N 4N1
| | - Siobhan M. Wong King Yuen
- Department of Biochemistry and Molecular Biology, University of British Columbia, 2350 Health Sciences Mall, Vancouver, Canada V6T 1Z3
| | - Ruiwu Wang
- Libin Cardiovascular Institute of Alberta, Department of Physiology & Pharmacology, University of Calgary, Calgary, Alberta, Canada T2N 4N1
- Libin Cardiovascular Institute of Alberta, Department of Biochemistry & Molecular Biology, University of Calgary, Calgary, Alberta, Canada T2N 4N1
| | - Lin Zhang
- Libin Cardiovascular Institute of Alberta, Department of Physiology & Pharmacology, University of Calgary, Calgary, Alberta, Canada T2N 4N1
- Libin Cardiovascular Institute of Alberta, Department of Biochemistry & Molecular Biology, University of Calgary, Calgary, Alberta, Canada T2N 4N1
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, University of British Columbia, 2350 Health Sciences Mall, Vancouver, Canada V6T 1Z3
| | - S. R. Wayne Chen
- Libin Cardiovascular Institute of Alberta, Department of Physiology & Pharmacology, University of Calgary, Calgary, Alberta, Canada T2N 4N1
- Libin Cardiovascular Institute of Alberta, Department of Biochemistry & Molecular Biology, University of Calgary, Calgary, Alberta, Canada T2N 4N1
- * E-mail:
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50
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Søndergaard MT, Tian X, Liu Y, Wang R, Chazin WJ, Chen SRW, Overgaard MT. Arrhythmogenic Calmodulin Mutations Affect the Activation and Termination of Cardiac Ryanodine Receptor-mediated Ca2+ Release. J Biol Chem 2015; 290:26151-62. [PMID: 26309258 DOI: 10.1074/jbc.m115.676627] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Indexed: 11/06/2022] Open
Abstract
The intracellular Ca(2+) sensor calmodulin (CaM) regulates the cardiac Ca(2+) release channel/ryanodine receptor 2 (RyR2), and mutations in CaM cause arrhythmias such as catecholaminergic polymorphic ventricular tachycardia (CPVT) and long QT syndrome. Here, we investigated the effect of CaM mutations causing CPVT (N53I), long QT syndrome (D95V and D129G), or both (CaM N97S) on RyR2-mediated Ca(2+) release. All mutations increased Ca(2+) release and rendered RyR2 more susceptible to store overload-induced Ca(2+) release (SOICR) by lowering the threshold of store Ca(2+) content at which SOICR occurred and the threshold at which SOICR terminated. To obtain mechanistic insights, we investigated the Ca(2+) binding of the N- and C-terminal domains (N- and C-domain) of CaM in the presence of a peptide corresponding to the CaM-binding domain of RyR2. The N53I mutation decreased the affinity of Ca(2+) binding to the N-domain of CaM, relative to CaM WT, but did not affect the C-domain. Conversely, mutations N97S, D95V, and D129G had little or no effect on Ca(2+) binding to the N-domain but markedly decreased the affinity of the C-domain for Ca(2+). These results suggest that mutations D95V, N97S, and D129G alter the interaction between CaM and the CaMBD and thus RyR2 regulation. Because the N53I mutation minimally affected Ca(2+) binding to the C-domain, it must cause aberrant regulation via a different mechanism. These results support aberrant RyR2 regulation as the disease mechanism for CPVT associated with CaM mutations and shows that CaM mutations not associated with CPVT can also affect RyR2. A model for the CaM-RyR2 interaction, where the Ca(2+)-saturated C-domain is constitutively bound to RyR2 and the N-domain senses increases in Ca(2+) concentration, is proposed.
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Affiliation(s)
- Mads T Søndergaard
- From the Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg, Denmark, the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology and Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 1N4, Canada, and
| | - Xixi Tian
- the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology and Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 1N4, Canada, and
| | - Yingjie Liu
- the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology and Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 1N4, Canada, and
| | - Ruiwu Wang
- the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology and Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 1N4, Canada, and
| | - Walter J Chazin
- the Departments of Biochemistry and Chemistry, Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37235
| | - S R Wayne Chen
- the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology and Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 1N4, Canada, and
| | - Michael T Overgaard
- From the Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg, Denmark,
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