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Liu YB, Wang Q, Song YL, Song XM, Fan YC, Kong L, Zhang JS, Li S, Lv YJ, Li ZY, Dai JY, Qiu ZK. Abnormal phosphorylation / dephosphorylation and Ca 2+ dysfunction in heart failure. Heart Fail Rev 2024; 29:751-768. [PMID: 38498262 DOI: 10.1007/s10741-024-10395-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/01/2024] [Indexed: 03/20/2024]
Abstract
Heart failure (HF) can be caused by a variety of causes characterized by abnormal myocardial systole and diastole. Ca2+ current through the L-type calcium channel (LTCC) on the membrane is the initial trigger signal for a cardiac cycle. Declined systole and diastole in HF are associated with dysfunction of myocardial Ca2+ function. This disorder can be correlated with unbalanced levels of phosphorylation / dephosphorylation of LTCC, endoplasmic reticulum (ER), and myofilament. Kinase and phosphatase activity changes along with HF progress, resulting in phased changes in the degree of phosphorylation / dephosphorylation. It is important to realize the phosphorylation / dephosphorylation differences between a normal and a failing heart. This review focuses on phosphorylation / dephosphorylation changes in the progression of HF and summarizes the effects of phosphorylation / dephosphorylation of LTCC, ER function, and myofilament function in normal conditions and HF based on previous experiments and clinical research. Also, we summarize current therapeutic methods based on abnormal phosphorylation / dephosphorylation and clarify potential therapeutic directions.
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Affiliation(s)
- Yan-Bing Liu
- Interventional Medical Center, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao, 266003, Shandong Province, China
- Medical College, Qingdao University, Qingdao, China
| | - Qian Wang
- Medical College, Qingdao University, Qingdao, China
| | - Yu-Ling Song
- Department of Pediatrics, Huantai County Hospital of Traditional Chinese Medicine, Zibo, China
| | | | - Yu-Chen Fan
- Medical College, Qingdao University, Qingdao, China
| | - Lin Kong
- Medical College, Qingdao University, Qingdao, China
| | | | - Sheng Li
- Medical College, Qingdao University, Qingdao, China
| | - Yi-Ju Lv
- Medical College, Qingdao University, Qingdao, China
| | - Ze-Yang Li
- Medical College, Qingdao University, Qingdao, China
| | - Jing-Yu Dai
- Department of Oncology, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao, 266003, Shandong Province, China.
| | - Zhen-Kang Qiu
- Interventional Medical Center, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao, 266003, Shandong Province, China.
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2
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Hagio H, Koyama W, Hosaka S, Song AD, Narantsatsral J, Matsuda K, Shimizu T, Hososhima S, Tsunoda SP, Kandori H, Hibi M. Optogenetic manipulation of neuronal and cardiomyocyte functions in zebrafish using microbial rhodopsins and adenylyl cyclases. eLife 2023; 12:e83975. [PMID: 37589546 PMCID: PMC10435232 DOI: 10.7554/elife.83975] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 07/25/2023] [Indexed: 08/18/2023] Open
Abstract
Even though microbial photosensitive proteins have been used for optogenetics, their use should be optimized to precisely control cell and tissue functions in vivo. We exploited GtCCR4 and KnChR, cation channelrhodopsins from algae, BeGC1, a guanylyl cyclase rhodopsin from a fungus, and photoactivated adenylyl cyclases (PACs) from cyanobacteria (OaPAC) or bacteria (bPAC), to control cell functions in zebrafish. Optical activation of GtCCR4 and KnChR in the hindbrain reticulospinal V2a neurons, which are involved in locomotion, induced swimming behavior at relatively short latencies, whereas activation of BeGC1 or PACs achieved it at long latencies. Activation of GtCCR4 and KnChR in cardiomyocytes induced cardiac arrest, whereas activation of bPAC gradually induced bradycardia. KnChR activation led to an increase in intracellular Ca2+ in the heart, suggesting that depolarization caused cardiac arrest. These data suggest that these optogenetic tools can be used to reveal the function and regulation of zebrafish neurons and cardiomyocytes.
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Affiliation(s)
- Hanako Hagio
- Graduate School of Science, Nagoya University, JapanNagoyaJapan
- Graduate School of Bioagricultural Sciences, Nagoya UniversityNagoyaJapan
- Institute for Advanced Research, Nagoya UniversityNagoyaJapan
| | - Wataru Koyama
- Graduate School of Science, Nagoya University, JapanNagoyaJapan
| | - Shiori Hosaka
- Graduate School of Science, Nagoya University, JapanNagoyaJapan
| | | | | | - Koji Matsuda
- Graduate School of Science, Nagoya University, JapanNagoyaJapan
| | - Takashi Shimizu
- Graduate School of Science, Nagoya University, JapanNagoyaJapan
| | - Shoko Hososhima
- Department of Life Science and Applied Chemistry, Nagoya Institute of TechnologyNagoyaJapan
| | - Satoshi P Tsunoda
- Department of Life Science and Applied Chemistry, Nagoya Institute of TechnologyNagoyaJapan
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry, Nagoya Institute of TechnologyNagoyaJapan
| | - Masahiko Hibi
- Graduate School of Science, Nagoya University, JapanNagoyaJapan
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Dayer N, Ltaief Z, Liaudet L, Lechartier B, Aubert JD, Yerly P. Pressure Overload and Right Ventricular Failure: From Pathophysiology to Treatment. J Clin Med 2023; 12:4722. [PMID: 37510837 PMCID: PMC10380537 DOI: 10.3390/jcm12144722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 07/01/2023] [Accepted: 07/13/2023] [Indexed: 07/30/2023] Open
Abstract
Right ventricular failure (RVF) is often caused by increased afterload and disrupted coupling between the right ventricle (RV) and the pulmonary arteries (PAs). After a phase of adaptive hypertrophy, pressure-overloaded RVs evolve towards maladaptive hypertrophy and finally ventricular dilatation, with reduced stroke volume and systemic congestion. In this article, we review the concept of RV-PA coupling, which depicts the interaction between RV contractility and afterload, as well as the invasive and non-invasive techniques for its assessment. The current principles of RVF management based on pathophysiology and underlying etiology are subsequently discussed. Treatment strategies remain a challenge and range from fluid management and afterload reduction in moderate RVF to vasopressor therapy, inotropic support and, occasionally, mechanical circulatory support in severe RVF.
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Affiliation(s)
- Nicolas Dayer
- Department of Cardiology, Lausanne University Hospital and Lausanne University, 1011 Lausanne, Switzerland;
| | - Zied Ltaief
- Department of Adult Intensive Care Medicine, Lausanne University Hospital and Lausanne University, 1011 Lausanne, Switzerland; (Z.L.); (L.L.)
| | - Lucas Liaudet
- Department of Adult Intensive Care Medicine, Lausanne University Hospital and Lausanne University, 1011 Lausanne, Switzerland; (Z.L.); (L.L.)
| | - Benoit Lechartier
- Department of Respiratory Medicine, Lausanne University Hospital and Lausanne University, 1011 Lausanne, Switzerland; (B.L.); (J.-D.A.)
| | - John-David Aubert
- Department of Respiratory Medicine, Lausanne University Hospital and Lausanne University, 1011 Lausanne, Switzerland; (B.L.); (J.-D.A.)
| | - Patrick Yerly
- Department of Cardiology, Lausanne University Hospital and Lausanne University, 1011 Lausanne, Switzerland;
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4
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Collins KB, Scott JD. Phosphorylation, compartmentalization, and cardiac function. IUBMB Life 2023; 75:353-369. [PMID: 36177749 PMCID: PMC10049969 DOI: 10.1002/iub.2677] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 09/15/2022] [Indexed: 11/08/2022]
Abstract
Protein phosphorylation is a fundamental element of cell signaling. First discovered as a biochemical switch in glycogen metabolism, we now know that this posttranslational modification permeates all aspects of cellular behavior. In humans, over 540 protein kinases attach phosphate to acceptor amino acids, whereas around 160 phosphoprotein phosphatases remove phosphate to terminate signaling. Aberrant phosphorylation underlies disease, and kinase inhibitor drugs are increasingly used clinically as targeted therapies. Specificity in protein phosphorylation is achieved in part because kinases and phosphatases are spatially organized inside cells. A prototypic example is compartmentalization of the cyclic adenosine 3',5'-monophosphate (cAMP)-dependent protein kinase A through association with A-kinase anchoring proteins. This configuration creates autonomous signaling islands where the anchored kinase is constrained in proximity to activators, effectors, and selected substates. This article primarily focuses on A kinase anchoring protein (AKAP) signaling in the heart with an emphasis on anchoring proteins that spatiotemporally coordinate excitation-contraction coupling and hypertrophic responses.
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Affiliation(s)
- Kerrie B. Collins
- Department of Pharmacology, University of Washington, School of Medicine, 1959 NE Pacific Ave, Seattle WA, 98195
| | - John D. Scott
- Department of Pharmacology, University of Washington, School of Medicine, 1959 NE Pacific Ave, Seattle WA, 98195
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Hovey L, Guo X, Chen Y, Liu Q, Catterall WA. Impairment of β-adrenergic regulation and exacerbation of pressure-induced heart failure in mice with mutations in phosphoregulatory sites in the cardiac Ca V1.2 calcium channel. Front Physiol 2023; 14:1049611. [PMID: 36846334 PMCID: PMC9944942 DOI: 10.3389/fphys.2023.1049611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 01/10/2023] [Indexed: 02/10/2023] Open
Abstract
The cardiac calcium channel CaV1.2 conducts L-type calcium currents that initiate excitation-contraction coupling and serves as a crucial mediator of β-adrenergic regulation of the heart. We evaluated the inotropic response of mice with mutations in C-terminal phosphoregulatory sites under physiological levels of β-adrenergic stimulation in vivo, and we assessed the impact of combining mutations of C-terminal phosphoregulatory sites with chronic pressure-overload stress. Mice with Ser1700Ala (S1700A), Ser1700Ala/Thr1704Ala (STAA), and Ser1928Ala (S1928A) mutations had impaired baseline regulation of ventricular contractility and exhibited decreased inotropic response to low doses of β-adrenergic agonist. In contrast, treatment with supraphysiogical doses of agonist revealed substantial inotropic reserve that compensated for these deficits. Hypertrophy and heart failure in response to transverse aortic constriction (TAC) were exacerbated in S1700A, STAA, and S1928A mice whose β-adrenergic regulation of CaV1.2 channels was blunted. These findings further elucidate the role of phosphorylation of CaV1.2 at regulatory sites in the C-terminal domain for maintaining normal cardiac homeostasis, responding to physiological levels of β-adrenergic stimulation in the fight-or-flight response, and adapting to pressure-overload stress.
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Affiliation(s)
- Liam Hovey
- Department of Pharmacology, School of Medicine, University of Washington, Seattle, WA, United States
- Medical Scientist Training Program, School of Medicine, University of Washington, Seattle, WA, United States
| | - Xiaoyun Guo
- Department of Physiology and Biophysics, School of Medicine, University of Washington, Seattle, WA, United States
| | - Yi Chen
- Department of Physiology and Biophysics, School of Medicine, University of Washington, Seattle, WA, United States
| | - Qinghang Liu
- Department of Physiology and Biophysics, School of Medicine, University of Washington, Seattle, WA, United States
| | - William A. Catterall
- Medical Scientist Training Program, School of Medicine, University of Washington, Seattle, WA, United States
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Johri N, Matreja PS, Maurya A, Varshney S, Smritigandha. Role of β-blockers in Preventing Heart Failure and Major Adverse Cardiac Events Post Myocardial Infarction. Curr Cardiol Rev 2023; 19:e110123212591. [PMID: 36635926 PMCID: PMC10494272 DOI: 10.2174/1573403x19666230111143901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 10/26/2022] [Accepted: 10/31/2022] [Indexed: 01/14/2023] Open
Abstract
β-blockers have been widely utilized as a part of acute myocardial infarction (AMI) treatment for the past 40 years. Patients receiving β-adrenergic blockers for an extended period following myocardial infarction have a higher chance of surviving. Although many patients benefited from β-blockers, many do not, including those with myocardial infarction, left ventricle dysfunction, chronic pulmonary disease, and elderly people. In individuals with the post-acute coronary syndrome and normal left ventricular ejection fraction (LVEF), the appropriate duration of betablocker therapy is still unknown. There is also no time limit for those without angina and those who do not need β-blockers for arrhythmia or hypertension. Interestingly, β-blockers have been prescribed for more than four decades. The novel mechanism of action on cellular compartments has been found continually, which opens a new way for their potential application in cardiac failure and other cardiac events like post-myocardial infarction. Here, in this review, we studied β-blocker usage in these circumstances and the current recommendations for β-blocker use from clinical practice guidelines.
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Affiliation(s)
- Nishant Johri
- Department of Pharmacy Practice, Teerthanker Mahaveer College of Pharmacy, Moradabad, Uttar Pradesh, India
| | - Prithpal S. Matreja
- Department of Pharmacology, Teerthanker Mahaveer Medical College and Research Centre, Moradabad, Uttar Pradesh, India
| | - Aditya Maurya
- Department of Pharmacy Practice, Teerthanker Mahaveer College of Pharmacy, Moradabad, Uttar Pradesh, India
| | - Shivani Varshney
- Department of Pharmacy Practice, Teerthanker Mahaveer College of Pharmacy, Moradabad, Uttar Pradesh, India
| | - Smritigandha
- Department of Pharmacy Practice, Teerthanker Mahaveer College of Pharmacy, Moradabad, Uttar Pradesh, India
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7
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Martín-Aragón Baudel M, Flores-Tamez VA, Hong J, Reddy GR, Maillard P, Burns AE, Man KNM, Sasse KC, Ward SM, Catterall WA, Bers DM, Hell JW, Nieves-Cintrón M, Navedo MF. Spatiotemporal Control of Vascular Ca V1.2 by α1 C S1928 Phosphorylation. Circ Res 2022; 131:1018-1033. [PMID: 36345826 PMCID: PMC9722584 DOI: 10.1161/circresaha.122.321479] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 10/13/2022] [Accepted: 10/27/2022] [Indexed: 11/10/2022]
Abstract
BACKGROUND L-type CaV1.2 channels undergo cooperative gating to regulate cell function, although mechanisms are unclear. This study tests the hypothesis that phosphorylation of the CaV1.2 pore-forming subunit α1C at S1928 mediates vascular CaV1.2 cooperativity during diabetic hyperglycemia. METHODS A multiscale approach including patch-clamp electrophysiology, super-resolution nanoscopy, proximity ligation assay, calcium imaging' pressure myography, and Laser Speckle imaging was implemented to examine CaV1.2 cooperativity, α1C clustering, myogenic tone, and blood flow in human and mouse arterial myocytes/vessels. RESULTS CaV1.2 activity and cooperative gating increase in arterial myocytes from patients with type 2 diabetes and type 1 diabetic mice, and in wild-type mouse arterial myocytes after elevating extracellular glucose. These changes were prevented in wild-type cells pre-exposed to a PKA inhibitor or cells from knock-in S1928A but not S1700A mice. In addition, α1C clustering at the surface membrane of wild-type, but not wild-type cells pre-exposed to PKA or P2Y11 inhibitors and S1928A arterial myocytes, was elevated upon hyperglycemia and diabetes. CaV1.2 spatial and gating remodeling correlated with enhanced arterial myocyte Ca2+ influx and contractility and in vivo reduction in arterial diameter and blood flow upon hyperglycemia and diabetes in wild-type but not S1928A cells/mice. CONCLUSIONS These results suggest that PKA-dependent S1928 phosphorylation promotes the spatial reorganization of vascular α1C into "superclusters" upon hyperglycemia and diabetes. This triggers CaV1.2 activity and cooperativity, directly impacting vascular reactivity. The results may lay the foundation for developing therapeutics to correct CaV1.2 and arterial function during diabetic hyperglycemia.
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Affiliation(s)
- Miguel Martín-Aragón Baudel
- Department of Pharmacology, University of California Davis, Davis, CA (M.M.-A.B., V.A.F.-T., J.H., G.R.R., A.E.B., K.N.M.M., D.M.B., J.W.H., M.N.-C., M.F.N.)
| | - Victor A. Flores-Tamez
- Department of Pharmacology, University of California Davis, Davis, CA (M.M.-A.B., V.A.F.-T., J.H., G.R.R., A.E.B., K.N.M.M., D.M.B., J.W.H., M.N.-C., M.F.N.)
| | - Junyoung Hong
- Department of Pharmacology, University of California Davis, Davis, CA (M.M.-A.B., V.A.F.-T., J.H., G.R.R., A.E.B., K.N.M.M., D.M.B., J.W.H., M.N.-C., M.F.N.)
| | - Gopyreddy R. Reddy
- Department of Pharmacology, University of California Davis, Davis, CA (M.M.-A.B., V.A.F.-T., J.H., G.R.R., A.E.B., K.N.M.M., D.M.B., J.W.H., M.N.-C., M.F.N.)
| | - Pauline Maillard
- Department of Neurology, University of California Davis, Davis, CA (P.M.)
| | - Abby E. Burns
- Department of Pharmacology, University of California Davis, Davis, CA (M.M.-A.B., V.A.F.-T., J.H., G.R.R., A.E.B., K.N.M.M., D.M.B., J.W.H., M.N.-C., M.F.N.)
| | - Kwun Nok Mimi Man
- Department of Pharmacology, University of California Davis, Davis, CA (M.M.-A.B., V.A.F.-T., J.H., G.R.R., A.E.B., K.N.M.M., D.M.B., J.W.H., M.N.-C., M.F.N.)
| | | | - Sean M. Ward
- Department of Physiology and Cell Biology, University of Nevada Reno, Reno, NV (S.M.W.)
| | | | - Donald M. Bers
- Department of Pharmacology, University of California Davis, Davis, CA (M.M.-A.B., V.A.F.-T., J.H., G.R.R., A.E.B., K.N.M.M., D.M.B., J.W.H., M.N.-C., M.F.N.)
| | - Johannes W. Hell
- Department of Pharmacology, University of California Davis, Davis, CA (M.M.-A.B., V.A.F.-T., J.H., G.R.R., A.E.B., K.N.M.M., D.M.B., J.W.H., M.N.-C., M.F.N.)
| | - Madeline Nieves-Cintrón
- Department of Pharmacology, University of California Davis, Davis, CA (M.M.-A.B., V.A.F.-T., J.H., G.R.R., A.E.B., K.N.M.M., D.M.B., J.W.H., M.N.-C., M.F.N.)
| | - Manuel F. Navedo
- Department of Pharmacology, University of California Davis, Davis, CA (M.M.-A.B., V.A.F.-T., J.H., G.R.R., A.E.B., K.N.M.M., D.M.B., J.W.H., M.N.-C., M.F.N.)
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8
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Convergent regulation of Ca V1.2 channels by direct phosphorylation and by the small GTPase RAD in the cardiac fight-or-flight response. Proc Natl Acad Sci U S A 2022; 119:e2208533119. [PMID: 36215501 PMCID: PMC9586275 DOI: 10.1073/pnas.2208533119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The L-type calcium currents conducted by the cardiac CaV1.2 calcium channel initiate excitation-contraction coupling and serve as a key regulator of heart rate, rhythm, and force of contraction. CaV1.2 is regulated by β-adrenergic/protein kinase A (PKA)-mediated protein phosphorylation, proteolytic processing, and autoinhibition by its carboxyl-terminal domain (CT). The small guanosine triphosphatase (GTPase) RAD (Ras associated with diabetes) has emerged as a potent inhibitor of CaV1.2, and accumulating evidence suggests a key role for RAD in mediating β-adrenergic/PKA upregulation of channel activity. However, the relative roles of direct phosphorylation of CaV1.2 channels and phosphorylation of RAD in channel regulation remain uncertain. Here, we investigated the hypothesis that these two mechanisms converge to regulate CaV1.2 channels. Both RAD and the proteolytically processed distal CT (dCT) strongly reduced CaV1.2 activity. PKA phosphorylation of RAD and phosphorylation of Ser-1700 in the proximal CT (pCT) synergistically reversed this inhibition and increased CaV1.2 currents. Our findings reveal that the proteolytically processed form of CaV1.2 undergoes convergent regulation by direct phosphorylation of the CT and by phosphorylation of RAD. These parallel regulatory pathways provide a flexible mechanism for upregulation of the activity of CaV1.2 channels in the fight-or-flight response.
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9
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Choi S, Vivas O, Baudot M, Moreno CM. Aging Alters the Formation and Functionality of Signaling Microdomains Between L-type Calcium Channels and β2-Adrenergic Receptors in Cardiac Pacemaker Cells. Front Physiol 2022; 13:805909. [PMID: 35514336 PMCID: PMC9065441 DOI: 10.3389/fphys.2022.805909] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 03/03/2022] [Indexed: 12/19/2022] Open
Abstract
Heart rate is accelerated to match physiological demands through the action of noradrenaline on the cardiac pacemaker. Noradrenaline is released from sympathetic terminals and activates β1-and β2-adrenergic receptors (ΑRs) located at the plasma membrane of pacemaker cells. L-type calcium channels are one of the main downstream targets potentiated by the activation of β-ARs. For this signaling to occur, L-type calcium channels need to be located in close proximity to β-ARs inside caveolae. Although it is known that aging causes a slowdown of the pacemaker rate and a reduction in the response of pacemaker cells to noradrenaline, there is a lack of in-depth mechanistic insights into these age-associated changes. Here, we show that aging affects the formation and function of adrenergic signaling microdomains inside caveolae. By evaluating the β1 and β2 components of the adrenergic regulation of the L-type calcium current, we show that aging does not alter the regulation mediated by β1-ARs but drastically impairs that mediated by β2-ARs. We studied the integrity of the signaling microdomains formed between L-type calcium channels and β-ARs by combining high-resolution microscopy and proximity ligation assays. We show that consistent with the electrophysiological data, aging decreases the physical association between β2-ARs and L-type calcium channels. Interestingly, this reduction is associated with a decrease in the association of L-type calcium channels with the scaffolding protein AKAP150. Old pacemaker cells also have a reduction in caveolae density and in the association of L-type calcium channels with caveolin-3. Together the age-dependent alterations in caveolar formation and the nano-organization of β2-ARs and L-type calcium channels result in a reduced sensitivity of the channels to β2 adrenergic modulation. Our results highlight the importance of these signaling microdomains in maintaining the chronotropic modulation of the heart and also pinpoint the direct impact that aging has on their function.
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Affiliation(s)
- Sabrina Choi
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, United States
| | - Oscar Vivas
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, United States
| | - Matthias Baudot
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, United States
| | - Claudia M Moreno
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, United States
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10
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Abstract
Each heartbeat is initiated by the action potential, an electrical signal that depolarizes the plasma membrane and activates a cycle of calcium influx via voltage-gated calcium channels, calcium release via ryanodine receptors, and calcium reuptake and efflux via calcium-ATPase pumps and sodium-calcium exchangers. Agonists of the sympathetic nervous system bind to adrenergic receptors in cardiomyocytes, which, via cascading signal transduction pathways and protein kinase A (PKA), increase the heart rate (chronotropy), the strength of myocardial contraction (inotropy), and the rate of myocardial relaxation (lusitropy). These effects correlate with increased intracellular concentration of calcium, which is required for the augmentation of cardiomyocyte contraction. Despite extensive investigations, the molecular mechanisms underlying sympathetic nervous system regulation of calcium influx in cardiomyocytes have remained elusive over the last 40 years. Recent studies have uncovered the mechanisms underlying this fundamental biologic process, namely that PKA phosphorylates a calcium channel inhibitor, Rad, thereby releasing inhibition and increasing calcium influx. Here, we describe an updated model for how signals from adrenergic agonists are transduced to stimulate calcium influx and contractility in the heart.
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Affiliation(s)
- Arianne Papa
- Department of Physiology and Cellular Biophysics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Jared Kushner
- Division of Cardiology, Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA;
| | - Steven O Marx
- Division of Cardiology, Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA;
- Department of Molecular Pharmacology and Therapeutics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
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11
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Al Katat A, Zhao J, Calderone A, Parent L. Sympathetic Stimulation Upregulates the Ca 2+ Channel Subunit, Ca Vα2δ1, via the β1 and ERK 1/2 Pathway in Neonatal Ventricular Cardiomyocytes. Cells 2022; 11:188. [PMID: 35053304 PMCID: PMC8774121 DOI: 10.3390/cells11020188] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Revised: 12/29/2021] [Accepted: 01/03/2022] [Indexed: 02/04/2023] Open
Abstract
Intracellular Ca2+ overload secondary to chronic hemodynamic stimuli promotes the recruitment of Ca2+-dependent signaling implicated in cardiomyocyte hypertrophy. The present study tested the hypothesis that sympathetic-mediated hypertrophy of neonatal rat ventricular cardiomyocytes (NRVMs) translated to an increase in calcium influx secondary to the upregulation of CaV1.2 channel subunits. Confocal imaging of norepinephrine (NE)-treated NRVMs revealed a hypertrophic response compared to untreated NRVMs. L-type CaV1.2 peak current density was increased 4-fold following a 24-h stimulation with NE. NE-treated NRVMs exhibited a significant upregulation of CaVα2δ1 and CaVβ3 protein levels without significant changes of CaVα1C and CaVβ2 protein levels. Pre-treatment with the β1-blocker metoprolol failed to inhibit hypertrophy or CaVβ3 upregulation whereas CaVα2δ1 protein levels were significantly reduced. NE promoted the phosphorylation of ERK 1/2, and the response was attenuated by the β1-blocker. U0126 pre-treatment suppressed NE-induced ERK1/2 phosphorylation but failed to attenuate hypertrophy. U0126 inhibition of ERK1/2 phosphorylation prevented NE-mediated upregulation of CaVα2δ1, whereas CaVβ3 protein levels remained elevated. Thus, β1-adrenergic receptor-mediated recruitment of the ERK1/2 plays a seminal role in the upregulation of CaVα2δ1 in NRVMs independent of the concomitant hypertrophic response. However, the upregulation of CaVβ3 protein levels may be directly dependent on the hypertrophic response of NRVMs.
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Affiliation(s)
- Aya Al Katat
- Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC H3T 1J4, Canada; (A.A.K.); (A.C.)
- Research Center, Montreal Heart Institute, 5000 Rue Belanger, Montréal, QC H1T 1C8, Canada;
| | - Juan Zhao
- Research Center, Montreal Heart Institute, 5000 Rue Belanger, Montréal, QC H1T 1C8, Canada;
| | - Angelino Calderone
- Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC H3T 1J4, Canada; (A.A.K.); (A.C.)
- Research Center, Montreal Heart Institute, 5000 Rue Belanger, Montréal, QC H1T 1C8, Canada;
| | - Lucie Parent
- Département de Pharmacologie et Physiologie, Faculté de Médecine, Université de Montréal, Montréal, QC H3T 1J4, Canada; (A.A.K.); (A.C.)
- Research Center, Montreal Heart Institute, 5000 Rue Belanger, Montréal, QC H1T 1C8, Canada;
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12
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Marian AJ, Asatryan B, Wehrens XHT. Genetic basis and molecular biology of cardiac arrhythmias in cardiomyopathies. Cardiovasc Res 2021; 116:1600-1619. [PMID: 32348453 DOI: 10.1093/cvr/cvaa116] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/09/2020] [Accepted: 04/21/2020] [Indexed: 12/19/2022] Open
Abstract
Cardiac arrhythmias are common, often the first, and sometimes the life-threatening manifestations of hereditary cardiomyopathies. Pathogenic variants in several genes known to cause hereditary cardiac arrhythmias have also been identified in the sporadic cases and small families with cardiomyopathies. These findings suggest a shared genetic aetiology of a subset of hereditary cardiomyopathies and cardiac arrhythmias. The concept of a shared genetic aetiology is in accord with the complex and exquisite interplays that exist between the ion currents and cardiac mechanical function. However, neither the causal role of cardiac arrhythmias genes in cardiomyopathies is well established nor the causal role of cardiomyopathy genes in arrhythmias. On the contrary, secondary changes in ion currents, such as post-translational modifications, are common and contributors to the pathogenesis of arrhythmias in cardiomyopathies through altering biophysical and functional properties of the ion channels. Moreover, structural changes, such as cardiac hypertrophy, dilatation, and fibrosis provide a pro-arrhythmic substrate in hereditary cardiomyopathies. Genetic basis and molecular biology of cardiac arrhythmias in hereditary cardiomyopathies are discussed.
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Affiliation(s)
- Ali J Marian
- Department of Medicine, Center for Cardiovascular Genetics, Institute of Molecular Medicine, University of Texas Health Sciences Center at Houston, 6770 Bertner Street, Suite C900A, Houston, TX 77030, USA
| | - Babken Asatryan
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Xander H T Wehrens
- Department of Biophysics and Molecular Physiology, Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
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13
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Ávila RA, Rossi EM, de Carvalho GM, Krause M, Leopoldo AS, Carneiro MTWD, Dos Santos L. Moderate-intensity aerobic training reduces cardiac damage attributable to experimental iron overload in rats. Exp Physiol 2021; 106:1772-1784. [PMID: 34148259 DOI: 10.1113/ep089429] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 06/17/2021] [Indexed: 12/24/2022]
Abstract
NEW FINDINGS What is the central question of this study? The current literature indicates that oxidative stress plays a major role in iron overload. Although exercise is a well-established approach to treat/prevent cardiovascular diseases, its effects on iron overload are not known. What is the main finding and its importance? Moderate-intensity aerobic training had benefits in a rodent model of iron-overload cardiomyopathy by improving the antioxidant capacity of the heart. After further confirmation by translational and clinical studies, we should consider using this non-pharmacological, highly accessible and easily executable adjuvant approach allied to other therapies to improve the quality of life of iron-overloaded patients. ABSTRACT Iron is an essential micronutrient for several life processes, but its excess can damage organs owing to oxidative stress, with cardiomyopathy being the leading cause of death in iron-overloaded patients. Although exercise has long been considered as a cardioprotective tool, its effects on iron overload are not known. This study was designed to investigate the effects of moderate-intensity aerobic training in rats previously submitted to chronic iron overload. Wistar rats received i.p. injections of iron dextran (100 mg/kg, 5 days/week for 4 weeks); thereafter, the rats were kept sedentary or exercised (60 min/day, progressive aerobic training, 60-70% of maximal speed, 5 days/week on a treadmill) for 8 weeks. At the end of the experimental period, haemodynamics were recorded and blood samples, livers and hearts harvested. Myocardial mechanics of papillary muscles were assessed in vitro, and cardiac remodelling was evaluated by histology and immunoblotting. Iron overload led to liver iron deposition, liver fibrosis and increased serum alanine aminotransferase and aspartate aminotransferase. Moreover, cardiac iron accumulation was accompanied by impaired myocardial mechanics, increased cardiac collagen type I and lipid peroxidation (TBARS), and release of creatine phosphokinase-MB to the serum. Although exercise did not influence iron levels, tissue injury markers were significantly reduced. Likewise, myocardial contractility and inotropic responsiveness were improved in exercised rats, in association with an increase in the endogenous antioxidant enzyme catalase. In conclusion, moderate-intensity aerobic exercise was associated with attenuated oxidative stress and cardiac damage in a rodent model of iron overload, thereby suggesting its potential role as a non-pharmacological adjuvant therapy for iron-overload cardiomyopathy.
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Affiliation(s)
- Renata Andrade Ávila
- Department of Physiological Sciences, Federal University of Espirito Santo, Vitória, ES, Brazil.,Faculdades Integradas São Pedro (FAESA), Vitória, ES, Brazil
| | - Emilly Martinelli Rossi
- Department of Physiological Sciences, Federal University of Espirito Santo, Vitória, ES, Brazil
| | | | - Maiara Krause
- Department of Chemistry, Federal University of Espirito Santo, Vitória, ES, Brazil
| | | | | | - Leonardo Dos Santos
- Department of Physiological Sciences, Federal University of Espirito Santo, Vitória, ES, Brazil
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14
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Neumann J, Boknik P, Kirchhefer U, Gergs U. The role of PP5 and PP2C in cardiac health and disease. Cell Signal 2021; 85:110035. [PMID: 33964402 DOI: 10.1016/j.cellsig.2021.110035] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 04/16/2021] [Accepted: 05/03/2021] [Indexed: 02/08/2023]
Abstract
Protein phosphatases are important, for example, as functional antagonists of β-adrenergic stimulation of the mammalian heart. While β-adrenergic stimulations increase the phosphorylation state of regulatory proteins and therefore force of contraction in the heart, these phosphorylations are reversed and thus force is reduced by the activity of protein phosphatases. In this context the role of PP5 and PP2C is starting to unravel. They do not belong to the same family of phosphatases with regard to sequence homology, many similarities with regard to location, activation by lipids and putative substrates have been worked out over the years. We also suggest which pathways for regulation of PP5 and/or PP2C described in other tissues and not yet in the heart might be useful to look for in cardiac tissue. Both phosphatases might play a role in signal transduction of sarcolemmal receptors in the heart. Expression of PP5 and PP2C can be increased by extracellular stimuli in the heart. Because PP5 is overexpressed in failing animal and human hearts, and because overexpression of PP5 or PP2C leads to cardiac hypertrophy and KO of PP5 leads to cardiac hypotrophy, one might argue for a role of PP5 and PP2C in heart failure. Because PP5 and PP2C can reduce, at least in vitro, the phosphorylation state of proteins thought to be relevant for cardiac arrhythmias, a role of these phosphatases for cardiac arrhythmias is also probable. Thus, PP5 and PP2C might be druggable targets to treat important cardiac diseases like heart failure, cardiac hypertrophy and cardiac arrhythmias.
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Affiliation(s)
- Joachim Neumann
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, Magdeburger Str. 4, D-06097 Halle, Germany.
| | - Peter Boknik
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Westfälische Wilhelms-Universität, Domagkstraße 12, D-48149 Münster, Germany.
| | - Uwe Kirchhefer
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Westfälische Wilhelms-Universität, Domagkstraße 12, D-48149 Münster, Germany.
| | - Ulrich Gergs
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, Magdeburger Str. 4, D-06097 Halle, Germany.
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15
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Iqbal Z, Ismaili D, Dolce B, Petersen J, Reichenspurner H, Hansen A, Kirchhof P, Eschenhagen T, Nikolaev VO, Molina CE, Christ T. Regulation of basal and norepinephrine-induced cAMP and I Ca in hiPSC-cardiomyocytes: Effects of culture conditions and comparison to adult human atrial cardiomyocytes. Cell Signal 2021; 82:109970. [PMID: 33677066 DOI: 10.1016/j.cellsig.2021.109970] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 03/01/2021] [Accepted: 03/02/2021] [Indexed: 01/27/2023]
Abstract
BACKGROUND There is ongoing interest in generating cardiomyocytes derived from human induced pluripotent stem cells (hiPSC) to study human cardiac physiology and pathophysiology. Recently we found that norepinephrine-stimulated calcium currents (ICa) in hiPSC-cardiomyocytes were smaller in conventional monolayers (ML) than in engineered heart tissue (EHT). In order to elucidate culture specific regulation of β1-adrenoceptor (β1-AR) responses we investigated whether action of phosphodiesterases (PDEs) may limit norepinephrine effects on ICa and on cytosolic cAMP in hiPSC-cardiomyocytes. Results were compared to adult human atrial cardiomyocytes. METHODS Adult human atrial cardiomyocytes were isolated from tissue samples obtained during open heart surgery. All patients were in sinus rhythm. HiPSC-cardiomyocytes were dissociated from ML and EHT. Förster-resonance energy transfer (FRET) was used to monitor cytosolic cAMP (Epac1-camps sensor, transfected by adenovirus). ICa was recorded by whole-cell patch clamp technique. Cilostamide (300 nM) and rolipram (10 μM) were used to inhibit PDE3 and PDE4, respectively. β1-AR were stimulated with the physiological agonist norepinephrine (100 μM). RESULTS In adult human atrial cardiomyocytes, norepinephrine increased cytosolic cAMP FRET ratio by +13.7 ± 1.5% (n = 10/9, mean ± SEM, number of cells/number patients) and ICa by +10.4 ± 1.5 pA/pF (n = 15/10). This effect was not further increased in the concomitant presence of rolipram, cilostamide and norepinephrine, indicating saturation by norepinephrine alone. In ML hiPSC-cardiomyocytes, norepinephrine exerted smaller increases in cytosolic cAMP and ICa (FRET +9.6 ± 0.5% n = 52/21, number of cells/number of ML or EHT, and ICa + 1.4 ± 0.2 pA/pF n = 34/7, p < 0.05 each) and both were augmented in the presence of the PDE4 inhibitor rolipram (FRET +16.7 ± 0.8% n = 94/26 and ICa + 5.6 ± 1.4 pA/pF n = 11/5, p < 0.05 each). Cilostamide increased the response to norepinephrine on FRET (+12.7 ± 0.5% n = 91/19, p < 0.05), but not on ICa. In EHT hiPSC-cardiomyocytes, norepinephrine responses on both, FRET and ICa, were larger than in ML (FRET +12.1 ± 0.3% n = 87/32 and ICa + 3.3 ± 0.2 pA/pF n = 13/5, p < 0.05 each). Rolipram augmented the norepinephrine effect on ICa (+6.2 ± 1.6 pA/pF; p < 0.05 vs. norepinephrine alone, n = 10/4), but not on FRET. CONCLUSION Our results show culture-dependent differences in hiPSC-cardiomyocytes. In conventional ML but not in EHT, maximum norepinephrine effects on cytosolic cAMP depend on PDE3 and PDE4, suggesting immaturity when compared to the situation in adult human atrial cardiomyocytes. The smaller ICa responses to norepinephrine in ML and EHT vs. adult human atrial cardiomyocytes depend at least partially on a non-physiological large impact of PDE4 in hiPSC-cardiomyocytes.
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Affiliation(s)
- Zafar Iqbal
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Djemail Ismaili
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Department of Cardiology, University Heart and Vascular Center, Hamburg, Germany; DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany.
| | - Bernardo Dolce
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Johannes Petersen
- Department of Cardiovascular Surgery, University Heart and Vascular Center, Hamburg, Germany; DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Hermann Reichenspurner
- Department of Cardiovascular Surgery, University Heart and Vascular Center, Hamburg, Germany; DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Arne Hansen
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Paulus Kirchhof
- Department of Cardiology, University Heart and Vascular Center, Hamburg, Germany; Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, UK; DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Thomas Eschenhagen
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Viacheslav O Nikolaev
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Cristina E Molina
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Torsten Christ
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; DZHK (German Centre for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany.
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16
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Liu Y, Chen J, Fontes SK, Bautista EN, Cheng Z. Physiological And Pathological Roles Of Protein Kinase A In The Heart. Cardiovasc Res 2021; 118:386-398. [PMID: 33483740 DOI: 10.1093/cvr/cvab008] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 11/30/2020] [Accepted: 01/08/2021] [Indexed: 12/21/2022] Open
Abstract
Protein kinase A (PKA) is a central regulator of cardiac performance and morphology. Myocardial PKA activation is induced by a variety of hormones, neurotransmitters and stress signals, most notably catecholamines secreted by the sympathetic nervous system. Catecholamines bind β-adrenergic receptors to stimulate cAMP-dependent PKA activation in cardiomyocytes. Elevated PKA activity enhances Ca2+ cycling and increases cardiac muscle contractility. Dynamic control of PKA is essential for cardiac homeostasis, as dysregulation of PKA signaling is associated with a broad range of heart diseases. Specifically, abnormal PKA activation or inactivation contributes to the pathogenesis of myocardial ischemia, hypertrophy, heart failure, as well as diabetic, takotsubo, or anthracycline cardiomyopathies. PKA may also determine sex-dependent differences in contractile function and heart disease predisposition. Here, we describe the recent advances regarding the roles of PKA in cardiac physiology and pathology, highlighting previous study limitations and future research directions. Moreover, we discuss the therapeutic strategies and molecular mechanisms associated with cardiac PKA biology. In summary, PKA could serve as a promising drug target for cardioprotection. Depending on disease types and mechanisms, therapeutic intervention may require either inhibition or activation of PKA. Therefore, specific PKA inhibitors or activators may represent valuable drug candidates for the treatment of heart diseases.
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Affiliation(s)
- Yuening Liu
- Department of Pharmaceutical Sciences, Washington State University, PBS 423, 412 E. Spokane Falls Blvd, ., Spokane, WA, 99202-2131, USA
| | - Jingrui Chen
- Department of Pharmaceutical Sciences, Washington State University, PBS 423, 412 E. Spokane Falls Blvd, ., Spokane, WA, 99202-2131, USA
| | - Shayne K Fontes
- Department of Pharmaceutical Sciences, Washington State University, PBS 423, 412 E. Spokane Falls Blvd, ., Spokane, WA, 99202-2131, USA
| | - Erika N Bautista
- Department of Pharmaceutical Sciences, Washington State University, PBS 423, 412 E. Spokane Falls Blvd, ., Spokane, WA, 99202-2131, USA
| | - Zhaokang Cheng
- Department of Pharmaceutical Sciences, Washington State University, PBS 423, 412 E. Spokane Falls Blvd, ., Spokane, WA, 99202-2131, USA
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Man KNM, Bartels P, Horne MC, Hell JW. Tissue-specific adrenergic regulation of the L-type Ca 2+ channel Ca V1.2. Sci Signal 2020; 13:13/663/eabc6438. [PMID: 33443233 DOI: 10.1126/scisignal.abc6438] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Ca2+ influx through the L-type Ca2+ channel Cav1.2 triggers each heartbeat. The fight-or-flight response induces the release of the stress response hormone norepinephrine to stimulate β-adrenergic receptors, cAMP production, and protein kinase A activity to augment Ca2+ influx through Cav1.2 and, consequently, cardiomyocyte contractility. Emerging evidence shows that Cav1.2 is regulated by different mechanisms in cardiomyocytes compared to neurons and vascular smooth muscle cells.
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Affiliation(s)
- Kwun Nok Mimi Man
- Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA
| | - Peter Bartels
- Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA
| | - Mary C Horne
- Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA.
| | - Johannes W Hell
- Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA.
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18
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Montenarh M, Götz C. Protein kinase CK2 and ion channels (Review). Biomed Rep 2020; 13:55. [PMID: 33082952 PMCID: PMC7560519 DOI: 10.3892/br.2020.1362] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 07/28/2020] [Indexed: 12/18/2022] Open
Abstract
Protein kinase CK2 appears as a tetramer or higher molecular weight oligomer composed of catalytic CK2α, CK2α' subunits and non-catalytic regulatory CK2β subunits or as individual subunits. It is implicated in a variety of different regulatory processes, such as Akt signalling, splicing and DNA repair within eukaryotic cells. The present review evaluates the influence of CK2 on ion channels in the plasma membrane. CK2 phosphorylates platform proteins such as calmodulin and ankyrin G, which bind to channel proteins for a physiological transport to and positioning into the membrane. In addition, CK2 directly phosphorylates a variety of channel proteins directly to regulate opening and closing of the channels. Thus, modulation of CK2 activities by specific inhibitors, by siRNA technology or by CRISPR/Cas technology has an influence on intracellular ion concentrations and thereby on cellular signalling. The physiological regulation of the intracellular ion concentration is important for cell survival and correct intracellular signalling. Disturbance of this regulation results in a variety of different diseases including epilepsy, heart failure, cystic fibrosis and diabetes. Therefore, these effects should be considered when using CK2 inhibition as a treatment option for cancer.
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Affiliation(s)
- Mathias Montenarh
- Medical Biochemistry and Molecular Biology, Saarland University, D-66424 Homburg, Saarland, Germany
| | - Claudia Götz
- Medical Biochemistry and Molecular Biology, Saarland University, D-66424 Homburg, Saarland, Germany
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19
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Chen X, Zhang C, Guo Y, Liu X, Ye T, Fo Y, Qu C, Liang J, Shi S, Yang B. Chronic stimulation of the sigma-1 receptor ameliorates ventricular ionic and structural remodeling in a rodent model of depression. Life Sci 2020; 257:118047. [PMID: 32629001 DOI: 10.1016/j.lfs.2020.118047] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 06/26/2020] [Accepted: 06/30/2020] [Indexed: 10/23/2022]
Abstract
AIM The purpose of the study was to investigate what effects the sigma-1 receptor (S1R) could exert on the cardiac myocyte ion channels in a rodent model of depression and to explore the underlying mechanisms since depression is an independent risk factor for cardiovascular diseases including ventricular arrhythmias (VAs). MATERIALS AND METHODS To establish the depression model in rats, chronic mild unpredictable stress (CMUS) for 28 days was used. The S1R agonist fluvoxamine was injected intraperitoneally from the second week to the last week for 21 days in total, and the effects were evaluated by patch clamp, western blot analysis, and Masson staining. KEY FINDINGS We demonstrated that depression was improved after treatment with fluvoxamine. In addition, the prolongation of the corrected QT (QTc) interval under CMUS that increased vulnerability to VAs was significantly attenuated by stimulation of S1R due to the decreased amplitude of L-type calcium current (ICa-L) and the restoration of reduced transient outward potassium current (Ito) resulting from CMUS induction. The S1R also decelerated Ito inactivation and accelerated Ito recovery by activating Ca2+/calmodulin-dependent kinase II. Moreover, the stimulation of S1R ameliorated the structural remodeling as the substrate for maintenance of VAs. All these effects were abolished by the administration of S1R antagonist BD1047, which verified the roles for S1R. SIGNIFICANCE Activation of S1R could decrease the vulnerability to VAs by inhibiting ICa-L and restoring Ito, in addition to ameliorating the CMUS-induced depressive symptoms and structural remodeling.
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Affiliation(s)
- Xiuhuan Chen
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Cardiovascular Research Institute, Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Cardiology, Wuhan 430060, PR China
| | - Cui Zhang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Cardiovascular Research Institute, Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Cardiology, Wuhan 430060, PR China
| | - Yan Guo
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Cardiovascular Research Institute, Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Cardiology, Wuhan 430060, PR China
| | - Xin Liu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Cardiovascular Research Institute, Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Cardiology, Wuhan 430060, PR China
| | - Tianxin Ye
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Cardiovascular Research Institute, Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Cardiology, Wuhan 430060, PR China
| | - Yuhong Fo
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Cardiovascular Research Institute, Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Cardiology, Wuhan 430060, PR China
| | - Chuan Qu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Cardiovascular Research Institute, Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Cardiology, Wuhan 430060, PR China
| | - Jinjun Liang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Cardiovascular Research Institute, Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Cardiology, Wuhan 430060, PR China
| | - Shaobo Shi
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Cardiovascular Research Institute, Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Cardiology, Wuhan 430060, PR China.
| | - Bo Yang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Cardiovascular Research Institute, Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Cardiology, Wuhan 430060, PR China.
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20
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Scheuer R, Philipp SE, Becker A, Nalbach L, Ampofo E, Montenarh M, Götz C. Protein Kinase CK2 Controls Ca V2.1-Dependent Calcium Currents and Insulin Release in Pancreatic β-Cells. Int J Mol Sci 2020; 21:ijms21134668. [PMID: 32630015 PMCID: PMC7370021 DOI: 10.3390/ijms21134668] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 06/18/2020] [Accepted: 06/26/2020] [Indexed: 12/21/2022] Open
Abstract
The regulation of insulin biosynthesis and secretion in pancreatic β-cells is essential for glucose homeostasis in humans. Previous findings point to the highly conserved, ubiquitously expressed serine/threonine kinase CK2 as having a negative regulatory impact on this regulation. In the cell culture model of rat pancreatic β-cells INS-1, insulin secretion is enhanced after CK2 inhibition. This enhancement is preceded by a rise in the cytosolic Ca2+ concentration. Here, we identified the serine residues S2362 and S2364 of the voltage-dependent calcium channel CaV2.1 as targets of CK2 phosphorylation. Furthermore, co-immunoprecipitation experiments revealed that CaV2.1 binds to CK2 in vitro and in vivo. CaV2.1 knockdown experiments showed that the increase in the intracellular Ca2+ concentration, followed by an enhanced insulin secretion upon CK2 inhibition, is due to a Ca2+ influx through CaV2.1 channels. In summary, our results point to a modulating role of CK2 in the CaV2.1-mediated exocytosis of insulin.
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Affiliation(s)
- Rebecca Scheuer
- Department of Medical Biochemistry and Molecular Biology, Saarland University, Kirrberger Str., bldg. 44, D-66424 Homburg, Germany; (R.S.); (M.M.)
| | - Stephan Ernst Philipp
- Department of Experimental and Clinical Pharmacology and Toxicology, Saarland University Kirrberger Str., bldg. 45-46, D-66424 Homburg, Germany; (S.E.P.); (A.B.)
| | - Alexander Becker
- Department of Experimental and Clinical Pharmacology and Toxicology, Saarland University Kirrberger Str., bldg. 45-46, D-66424 Homburg, Germany; (S.E.P.); (A.B.)
| | - Lisa Nalbach
- Institute for Clinical & Experimental Surgery, Saarland University Kirrberger Str., bldg. 65, D-66424 Homburg, Germany; (L.N.); (E.A.)
| | - Emmanuel Ampofo
- Institute for Clinical & Experimental Surgery, Saarland University Kirrberger Str., bldg. 65, D-66424 Homburg, Germany; (L.N.); (E.A.)
| | - Mathias Montenarh
- Department of Medical Biochemistry and Molecular Biology, Saarland University, Kirrberger Str., bldg. 44, D-66424 Homburg, Germany; (R.S.); (M.M.)
| | - Claudia Götz
- Department of Medical Biochemistry and Molecular Biology, Saarland University, Kirrberger Str., bldg. 44, D-66424 Homburg, Germany; (R.S.); (M.M.)
- Correspondence:
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21
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Regulation of cardiovascular calcium channel activity by post-translational modifications or interacting proteins. Pflugers Arch 2020; 472:653-667. [PMID: 32435990 DOI: 10.1007/s00424-020-02398-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 05/04/2020] [Accepted: 05/06/2020] [Indexed: 02/08/2023]
Abstract
Voltage-gated calcium channels are the major pathway for Ca2+ influx to initiate the contraction of smooth and cardiac muscles. Alterations of calcium channel function have been implicated in multiple cardiovascular diseases, such as hypertension, atrial fibrillation, and long QT syndrome. Post-translational modifications do expand cardiovascular calcium channel structure and function to affect processes such as channel trafficking or polyubiquitination by two E3 ubiquitin ligases, Ret finger protein 2 (Rfp2) or murine double minute 2 protein (Mdm2). Additionally, biophysical property such as Ca2+-dependent inactivation (CDI) could be altered through binding of calmodulin, or channel activity could be modulated via S-nitrosylation by nitric oxide and phosphorylation by protein kinases or by interacting protein partners, such as galectin-1 and Rem. Understanding how cardiovascular calcium channel function is post-translationally remodeled under distinctive disease conditions will provide better information about calcium channel-related disease mechanisms and improve the development of more selective therapeutic agents for cardiovascular diseases.
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Li J, Wang S, Zhang J, Liu Y, Zheng X, Ding F, Sun X, Zhao M, Hao L. The CaMKII phosphorylation site Thr1604 in the Ca V1.2 channel is involved in pathological myocardial hypertrophy in rats. Channels (Austin) 2020; 14:151-162. [PMID: 32290730 PMCID: PMC7188351 DOI: 10.1080/19336950.2020.1750189] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Residue Thr1604 in the CaV1.2 channel is a Ca2+/calmodulin dependent protein kinase II (CaMKII) phosphorylation site, and its phosphorylation status maintains the basic activity of the channel. However, the role of CaV1.2 phosphorylation at Thr1604 in myocardial hypertrophy is incompletely understood. Isoproterenol (ISO) was used to induce cardiomyocyte hypertrophy, and autocamtide-2-related inhibitory peptide (AIP) was added as a treatment. Rats in a myocardial hypertrophy development model were subcutaneously injected with ISO for two or three weeks. The heart and left ventricle weights, each of which were normalized to the body weight and cross-sectional area of the myocardial cells, were used to describe the degree of hypertrophy. Protein expression levels were detected by western blotting. CaMKII-induced CaV1.2 (Thr1604) phosphorylation (p-CaV1.2) was assayed by coimmunoprecipitation. The results showed that CaMKII, HDAC, MEF2 C, and atrial natriuretic peptide (ANP) expression was increased in the ISO group and downregulated by AIP treatment in vitro. There was no difference in the expression of these proteins between the ISO 2-week group and the ISO 3-week group in vivo. CaV1.2 channel expression did not change, but p-CaV1.2 expression was increased after ISO stimulation and decreased by AIP. In the rat model, p-CaV1.2 levels and CaMKII activity were much higher in the ISO 3-week group than in the ISO 2-week group. CaMKII-induced CaV1.2 channel phosphorylation at residue Thr1604 may be one of the key features of myocardial hypertrophy and disease development.Abbreviations: CaMKII: Ca2+/calmodulin dependent protein kinase II; p-CaMKII: autophosphorylated Ca2+/calmodulin dependent protein kinase II; CaM: calmodulin; AIP: autocamtide-2-related inhibitory peptide; ECC: excitation-contraction coupling; ISO: isoproterenol; BW: body weight; HW: heart weight; LVW: left ventricle weight; HDAC: histone deacetylase; p-HDAC: phosphorylated histone deacetylase; MEF2C: myocyte-specific enhancer factor 2C; ANP: atrial natriuretic peptide; PKC: protein kinase C
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Affiliation(s)
- Jingyuan Li
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, China
| | - Siqi Wang
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, China
| | - Jie Zhang
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, China
| | - Yan Liu
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, China
| | - Xi Zheng
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, China
| | - Fan Ding
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, China
| | - Xuefei Sun
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, China
| | - Meimi Zhao
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, China
| | - Liying Hao
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, China
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23
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New aspects in cardiac L-type Ca2+ channel regulation. Biochem Soc Trans 2020; 48:39-49. [PMID: 32065210 DOI: 10.1042/bst20190229] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 01/24/2020] [Accepted: 01/24/2020] [Indexed: 12/23/2022]
Abstract
Cardiac excitation-contraction coupling is initiated with the influx of Ca2+ ions across the plasma membrane through voltage-gated L-type calcium channels. This process is tightly regulated by modulation of the channel open probability and channel localization. Protein kinase A (PKA) is found in close association with the channel and is one of the main regulators of its function. Whether this kinase is modulating the channel open probability by phosphorylation of key residues or via alternative mechanisms is unclear. This review summarizes recent findings regarding the PKA-mediated channel modulation and will highlight recently discovered regulatory mechanisms that are independent of PKA activity and involve protein-protein interactions and channel localization.
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24
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Wang L, Dou W, Malhi M, Zhu M, Liu H, Plakhotnik J, Xu Z, Zhao Q, Chen J, Chen S, Hamilton R, Simmons CA, Maynes JT, Sun Y. Microdevice Platform for Continuous Measurement of Contractility, Beating Rate, and Beating Rhythm of Human-Induced Pluripotent Stem Cell-Cardiomyocytes inside a Controlled Incubator Environment. ACS APPLIED MATERIALS & INTERFACES 2018; 10:21173-21183. [PMID: 29874032 DOI: 10.1021/acsami.8b05407] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The heart completes a complex set of tasks, including the initiation or propagation of an electrical signal with regularity (proper heart rate and rhythm) and generating sufficient force of contraction (contractility). Probing mechanisms of heart diseases and quantifying drug efficacies demand a platform that is capable of continuous operation inside a cell incubator for long-term measurement of cardiomyocyte (CM) monolayers. Here, we report a microdevice array that is capable of performing continuous, long-term (14 days) measurement of contractility, beating rate, and beating rhythm in a monolayer of human-induced pluripotent stem cell-CMs (hiPSC-CMs). The device consists of a deformable membrane with embedded carbon nanotube (CNT)-based strain sensors. Contraction of the hiPSC-CMs seeded on the membrane induces electrical resistance change of the CNT strain sensor. Continuously reading the sensor signals revealed that hiPSC-CMs started to beat from day 2 and plateaued on day 5. Average contractile stress generated by a monolayer of hiPSC-CMs was determined to be 2.34 ± 0.041 kPa with a beating rate of 1.17 ± 0.068 Hz. The device arrays were also used to perform comprehensive measurement of the beating rate, rhythm, and contractility of the hiPSC-CMs and quantify the cell responses to different concentrations of agonists and antagonists, which altered the average contractile stress to the range of 1.15 ± 0.13 to 3.96 ± 0.53 kPa. The continuous measurement capability of the device arrays also enabled the generation of Poincaré plots for revealing subtle changes in the beating rhythm of hiPSC-CMs under different drug treatments.
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Affiliation(s)
- Li Wang
- Department of Mechanical and Industrial Engineering , University of Toronto , Toronto ON M5S 3G8 , Canada
| | - Wenkun Dou
- Department of Mechanical and Industrial Engineering , University of Toronto , Toronto ON M5S 3G8 , Canada
| | - Manpreet Malhi
- Hospital for Sick Children , Toronto ON M5G 1X8 , Canada
| | - Min Zhu
- Department of Mechanical and Industrial Engineering , University of Toronto , Toronto ON M5S 3G8 , Canada
| | - Haijiao Liu
- Department of Mechanical and Industrial Engineering , University of Toronto , Toronto ON M5S 3G8 , Canada
- Institute of Biomaterials and Biomedical Engineering , University of Toronto , Toronto ON M5S 3G9 , Canada
| | | | - Zhensong Xu
- Department of Mechanical and Industrial Engineering , University of Toronto , Toronto ON M5S 3G8 , Canada
| | - Qili Zhao
- Department of Mechanical and Industrial Engineering , University of Toronto , Toronto ON M5S 3G8 , Canada
| | - Jun Chen
- Department of Mechanical and Industrial Engineering , University of Toronto , Toronto ON M5S 3G8 , Canada
| | - Siyu Chen
- Department of Mechanical and Industrial Engineering , University of Toronto , Toronto ON M5S 3G8 , Canada
| | | | - Craig A Simmons
- Department of Mechanical and Industrial Engineering , University of Toronto , Toronto ON M5S 3G8 , Canada
- Institute of Biomaterials and Biomedical Engineering , University of Toronto , Toronto ON M5S 3G9 , Canada
| | - Jason T Maynes
- Hospital for Sick Children , Toronto ON M5G 1X8 , Canada
| | - Yu Sun
- Department of Mechanical and Industrial Engineering , University of Toronto , Toronto ON M5S 3G8 , Canada
- Institute of Biomaterials and Biomedical Engineering , University of Toronto , Toronto ON M5S 3G9 , Canada
- Department of Electrical and Computer Engineering , University of Toronto , Toronto ON M5S 3G4 , Canada
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25
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Lei M, Xu J, Gao Q, Minobe E, Kameyama M, Hao L. PKA phosphorylation of Cav1.2 channel modulates the interaction of calmodulin with the C terminal tail of the channel. J Pharmacol Sci 2018; 137:187-194. [PMID: 30042022 DOI: 10.1016/j.jphs.2018.05.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 05/18/2018] [Accepted: 05/28/2018] [Indexed: 11/16/2022] Open
Abstract
Activity of cardiac Cav1.2 channels is enhanced by cyclic AMP-PKA signaling. In this study, we studied the effects of PKA phosphorylation on the binding of calmodulin to the fragment peptide of the proximal C-terminal tail of α1C subunit (CT1, a.a. 1509-1789 of guinea-pig). In the pull-down assay, in vitro PKA phosphorylation significantly decreased calmodulin binding to CT1 (61%) at high [Ca2+]. The phosphoresistant (CT1SA) and phosphomimetic (CT1SD) CT1 mutants, in which three PKA sites (Ser1574, 1626, 1699) were mutated to Ala and Asp, respectively, bound with calmodulin with 99% and 65% amount, respectively, compared to that of wild-type CT1. In contrast, at low [Ca2+], calmodulin-binding to CT1SD was higher (33-35%) than that to CT1SA. The distal C-terminal region of α1C (CT3, a.a. 1942-2169) is known to interact with CT1 and inhibit channel activity. CT3 bound to CT1SD was also significantly less than that to CT1SA. In inside-out patch, PKA catalytic subunit (PKAc) facilitated Ca2+ channel activity at both high and low Ca2+ condition. Altogether, these results support the hypothesis that PKA phosphorylation may enhance channel activity and attenuate the Ca2+-dependent inactivation, at least partially, by modulating calmodulin-CT1 interaction both directly and indirectly via CT3-CT1 interaction.
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Affiliation(s)
- Ming Lei
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, 110122, China; Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8544, Japan
| | - Jianjun Xu
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8544, Japan.
| | - Qinghua Gao
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, 110122, China; Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8544, Japan
| | - Etsuko Minobe
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8544, Japan
| | - Masaki Kameyama
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8544, Japan
| | - Liying Hao
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, 110122, China.
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26
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Yu H, Yuan C, Westenbroek RE, Catterall WA. The AKAP Cypher/Zasp contributes to β-adrenergic/PKA stimulation of cardiac Ca V1.2 calcium channels. J Gen Physiol 2018; 150:883-889. [PMID: 29743299 PMCID: PMC5987873 DOI: 10.1085/jgp.201711818] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 09/26/2017] [Accepted: 03/07/2018] [Indexed: 11/24/2022] Open
Abstract
A-kinase anchoring proteins are required for β-adrenergic stimulation of L-type Ca2+ channels in cardiac myocytes, but the molecular species that is responsible for this regulation remains unknown. Yu et al. reveal that Cypher/Zasp is a key regulator of β-adrenergic regulation in cardiac myocytes. Stimulation of the L-type Ca2+ current conducted by CaV1.2 channels in cardiac myocytes by the β-adrenergic/protein kinase A (PKA) signaling pathway requires anchoring of PKA to the CaV1.2 channel by an A-kinase anchoring protein (AKAP). However, the AKAP(s) responsible for regulation in vivo remain unknown. Here, we test the role of the AKAP Cypher/Zasp in β-adrenergic regulation of CaV1.2 channels using physiological studies of cardiac ventricular myocytes from young-adult mice lacking the long form of Cypher/Zasp (LCyphKO mice). These myocytes have increased protein levels of CaV1.2, PKA, and calcineurin. In contrast, the cell surface density of CaV1.2 channels and the basal Ca2+ current conducted by CaV1.2 channels are significantly reduced without substantial changes to kinetics or voltage dependence. β-adrenergic regulation of these L-type Ca2+ currents is also significantly reduced in myocytes from LCyphKO mice, whether calculated as a stimulation ratio or as net-stimulated Ca2+ current. At 100 nM isoproterenol, the net β-adrenergic–Ca2+ current conducted by CaV1.2 channels was reduced to 39 ± 12% of wild type. However, concentration–response curves for β-adrenergic stimulation of myocytes from LCyphKO mice have concentrations that give a half-maximal response similar to those for wild-type mice. These results identify Cypher/Zasp as an important AKAP for β-adrenergic regulation of cardiac CaV1.2 channels. Other AKAPs may work cooperatively with Cypher/Zasp to give the full magnitude of β-adrenergic regulation of CaV1.2 channels observed in vivo.
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Affiliation(s)
- Haijie Yu
- Department of Pharmacology, University of Washington, Seattle, WA.,State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macau
| | - Can Yuan
- Department of Pharmacology, University of Washington, Seattle, WA
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27
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28
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Abstract
G protein-coupled receptors (GPCRs) transduce pleiotropic intracellular signals in a broad range of physiological responses and disease states. Activated GPCRs can undergo agonist-induced phosphorylation by G protein receptor kinases (GRKs) and second messenger-dependent protein kinases such as protein kinase A (PKA). Here, we characterize spatially segregated subpopulations of β2-adrenergic receptor (β2AR) undergoing selective phosphorylation by GRKs or PKA in a single cell. GRKs primarily label monomeric β2ARs that undergo endocytosis, whereas PKA modifies dimeric β2ARs that remain at the cell surface. In hippocampal neurons, PKA-phosphorylated β2ARs are enriched in dendrites, whereas GRK-phosphorylated β2ARs accumulate in soma, being excluded from dendrites in a neuron maturation-dependent manner. Moreover, we show that PKA-phosphorylated β2ARs are necessary to augment the activity of L-type calcium channel. Collectively, these findings provide evidence that functionally distinct subpopulations of this prototypical GPCR exist in a single cell. β2-adrenergic receptor (β2AR) can be phosphorylated by G protein receptor kinases and second messenger-dependent kinases. Here, the authors demonstrate that these phosphorylation events are specific to functionally distinct and spatially segregated subpopulations of β2AR that co-exist in a single cell.
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29
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Kumari N, Gaur H, Bhargava A. Cardiac voltage gated calcium channels and their regulation by β-adrenergic signaling. Life Sci 2017; 194:139-149. [PMID: 29288765 DOI: 10.1016/j.lfs.2017.12.033] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 12/17/2017] [Accepted: 12/24/2017] [Indexed: 01/08/2023]
Abstract
Voltage-gated calcium channels (VGCCs) are the predominant source of calcium influx in the heart leading to calcium-induced calcium release and ultimately excitation-contraction coupling. In the heart, VGCCs are modulated by the β-adrenergic signaling. Signaling through β-adrenergic receptors (βARs) and modulation of VGCCs by β-adrenergic signaling in the heart are critical signaling and changes to these have been significantly implicated in heart failure. However, data related to calcium channel dysfunction in heart failure is divergent and contradictory ranging from reduced function to no change in the calcium current. Many recent studies have highlighted the importance of functional and spatial microdomains in the heart and that may be the key to answer several puzzling questions. In this review, we have briefly discussed the types of VGCCs found in heart tissues, their structure, and significance in the normal and pathological condition of the heart. More importantly, we have reviewed the modulation of VGCCs by βARs in normal and pathological conditions incorporating functional and structural aspects. There are different types of βARs, each having their own significance in the functioning of the heart. Finally, we emphasize the importance of location of proteins as it relates to their function and modulation by co-signaling molecules. Its implication on the studies of heart failure is speculated.
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Affiliation(s)
- Neema Kumari
- Ion Channel Biology Lab, Department of Biotechnology, Indian Institute of Technology Hyderabad, Telangana 502285, India
| | - Himanshu Gaur
- Ion Channel Biology Lab, Department of Biotechnology, Indian Institute of Technology Hyderabad, Telangana 502285, India
| | - Anamika Bhargava
- Ion Channel Biology Lab, Department of Biotechnology, Indian Institute of Technology Hyderabad, Telangana 502285, India.
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30
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Regulation of microdomain voltage-gated L-type calcium channels in cardiac health and disease. CURRENT OPINION IN PHYSIOLOGY 2017; 2:13-18. [PMID: 29963649 DOI: 10.1016/j.cophys.2017.12.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Cav1.2 channels in the heart mediate excitation-contraction (E-C) coupling; tune cardiac excitability; and regulate gene expression. In ventricular myocytes, CaV1.2 channels are predominantly located in t-tubules where they are in proximity to ryanodine receptors to trigger cardiac E-C coupling. A subset of ventricular CaV1.2 channels existing on the surface sarcolemma, including in caveolae, have less well-defined functions. Cardiac CaV1.2 channels are famously up-regulated by protein kinase A as a component of the 'fight-or-flight' response. The molecular details of how this kinase regulates cardiac CaV1.2 channels are controversial and under intensive study. Here, we critically review recent work addressing the putative functions of microdomain cardiac CaV1.2 channels, and their regulation by distinct kinases in health and disease.
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31
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Chen D. Fractional Poisson-Nernst-Planck Model for Ion Channels I: Basic Formulations and Algorithms. Bull Math Biol 2017; 79:2696-2726. [PMID: 28940114 DOI: 10.1007/s11538-017-0349-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 09/15/2017] [Indexed: 11/28/2022]
Abstract
In this work, we propose a fractional Poisson-Nernst-Planck model to describe ion permeation in gated ion channels. Due to the intrinsic conformational changes, crowdedness in narrow channel pores, binding and trapping introduced by functioning units of channel proteins, ionic transport in the channel exhibits a power-law-like anomalous diffusion dynamics. We start from continuous-time random walk model for a single ion and use a long-tailed density distribution function for the particle jump waiting time, to derive the fractional Fokker-Planck equation. Then, it is generalized to the macroscopic fractional Poisson-Nernst-Planck model for ionic concentrations. Necessary computational algorithms are designed to implement numerical simulations for the proposed model, and the dynamics of gating current is investigated. Numerical simulations show that the fractional PNP model provides a more qualitatively reasonable match to the profile of gating currents from experimental observations. Meanwhile, the proposed model motivates new challenges in terms of mathematical modeling and computations.
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Affiliation(s)
- Duan Chen
- Department of Mathematics and Statistics, University of North Carolina at Charlotte, Charlotte, NC, USA.
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32
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Poomvanicha M, Matthes J, Domes K, Patrucco E, Angermeier E, Laugwitz KL, Schneider T, Hofmann F. Beta-adrenergic regulation of the heart expressing the Ser1700A/Thr1704A mutated Cav1.2 channel. J Mol Cell Cardiol 2017; 111:10-16. [PMID: 28778765 DOI: 10.1016/j.yjmcc.2017.07.119] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 07/25/2017] [Accepted: 07/28/2017] [Indexed: 01/07/2023]
Abstract
Beta-adrenergic stimulation of the heart increases ICa. PKA dependent phosphorylation of several amino acids (among them Ser 1700 and Thr 1704 in the carboxy-terminus of the Cav1.2 α1c subunit) has been implicated as decisive for the β-adrenergic up-regulation of cardiac ICa. Mutation of Ser 1700 and Thr 1704 to alanine results in the Cav1.2PKA_P2-/- mice. Cav1.2PKA_P2-/- mice display reduced cardiac L-type current. Fractional shortening and ejection fraction in the intact animal and ICa in isolated cardiomyocytes (CM) are stimulated by isoproterenol. Cardiac specific expression of the mutated Cav1.2PKA_P2-/- gene reduces Cav1.2 α1c protein concentration, ICa, and the β-adrenergic stimulation of L-type ICa in CMs. Single channels were not detected on the CM surface of the cCav1.2PKA_P2-/- hearts. This outcome supports the notion that S1700/1704 is essential for expression of the Cav1.2 channel and that isoproterenol stimulates ICa in Cav1.2PKA_P2-/- CMs.
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Affiliation(s)
- Montatip Poomvanicha
- Institut für Pharmakologie und Toxikologie, Technische Universität München, Germany
| | - Jan Matthes
- Institut für Pharmakologie und Toxikologie, University Cologne, Germany
| | - Katrin Domes
- Institut für Pharmakologie und Toxikologie, Technische Universität München, Germany
| | - Enrico Patrucco
- Institut für Pharmakologie und Toxikologie, Technische Universität München, Germany
| | - Elisabeth Angermeier
- Institut für Pharmakologie und Toxikologie, Technische Universität München, Germany
| | - Karl-Ludwig Laugwitz
- I. Medizinische Klinik und Poliklinik (Kardiologie, Angiologie & Pneumologie), Klinikum rechts der Isar-Technische Universität München, Ismaninger Straße 22, 81675 München, Germany
| | - Toni Schneider
- Institut für Neurophysiologie, University Cologne, Germany
| | - Franz Hofmann
- Institut für Pharmakologie und Toxikologie, Technische Universität München, Germany.
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Aromolaran AS, Boutjdir M. Cardiac Ion Channel Regulation in Obesity and the Metabolic Syndrome: Relevance to Long QT Syndrome and Atrial Fibrillation. Front Physiol 2017; 8:431. [PMID: 28680407 PMCID: PMC5479057 DOI: 10.3389/fphys.2017.00431] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 06/06/2017] [Indexed: 01/03/2023] Open
Abstract
Obesity and its associated metabolic dysregulation leading to metabolic syndrome is an epidemic that poses a significant public health problem. More than one-third of the world population is overweight or obese leading to enhanced risk of cardiovascular disease (CVD) incidence and mortality. Obesity predisposes to atrial fibrillation, ventricular, and supraventricular arrhythmias; conditions that are underlain by dysfunction in electrical activity of the heart. To date, current therapeutic options for cardiomyopathy of obesity are limited, suggesting that there is considerable room for development of therapeutic interventions with novel mechanisms of action that will help normalize rhythm in obese patients. Emerging candidates for modulation by obesity are cardiac ion channels and Ca handling proteins. However, the underlying molecular mechanisms of the impact of obesity on these channels/Ca handling proteins remain incompletely understood. Obesity is marked by accumulation of adipose tissue associated with a variety of adverse adaptations including dyslipidemia (or abnormal levels of serum free fatty acids), increased secretion of pro-inflammatory cytokines, fibrosis, hyperglycemia, and insulin resistance, that will cause electrical remodeling and thus predispose to arrhythmias. Further, adipose tissue is also associated with the accumulation of subcutaneous and visceral fat, which are marked by distinct signaling mechanisms. Thus, there may also be functional differences in the outcome of regional distribution of fat deposits on ion channel/Ca handling proteins expression. Evaluating alterations in their functional expression in obesity will lead to progress in the knowledge about the mechanisms responsible for obesity-related arrhythmias. These advances are likely to reveal new targets for pharmacological modulation. The objective of this article is to review cardiac ion channel/Ca handling proteins remodeling that predispose to arrhythmias. Understanding how obesity and related mechanisms lead to cardiac electrical remodeling is likely to have a significant medical and economic impact.
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Affiliation(s)
- Ademuyiwa S Aromolaran
- Cardiovascular Research Program, VA New York Harbor Healthcare SystemBrooklyn, NY, United States.,Departments of Medicine, Cell Biology and Pharmacology, State University of New York Downstate Medical CenterBrooklyn, NY, United States
| | - Mohamed Boutjdir
- Cardiovascular Research Program, VA New York Harbor Healthcare SystemBrooklyn, NY, United States.,Departments of Medicine, Cell Biology and Pharmacology, State University of New York Downstate Medical CenterBrooklyn, NY, United States.,Department of Medicine, New York University School of MedicineNew York, NY, United States
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34
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Oz S, Pankonien I, Belkacemi A, Flockerzi V, Klussmann E, Haase H, Dascal N. Protein kinase A regulates C-terminally truncated Ca V 1.2 in Xenopus oocytes: roles of N- and C-termini of the α 1C subunit. J Physiol 2017; 595:3181-3202. [PMID: 28194788 DOI: 10.1113/jp274015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 02/08/2017] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS β-Adrenergic stimulation enhances Ca2+ entry via L-type CaV 1.2 channels, causing stronger contraction of cardiac muscle cells. The signalling pathway involves activation of protein kinase A (PKA), but the molecular details of PKA regulation of CaV 1.2 remain controversial despite extensive research. We show that PKA regulation of CaV 1.2 can be reconstituted in Xenopus oocytes when the distal C-terminus (dCT) of the main subunit, α1C , is truncated. The PKA upregulation of CaV 1.2 does not require key factors previously implicated in this mechanism: the clipped dCT, the A kinase-anchoring protein 15 (AKAP15), the phosphorylation sites S1700, T1704 and S1928, or the β subunit of CaV 1.2. The gating element within the initial segment of the N-terminus of the cardiac isoform of α1C is essential for the PKA effect. We propose that the regulation described here is one of two or several mechanisms that jointly mediate the PKA regulation of CaV 1.2 in the heart. ABSTRACT β-Adrenergic stimulation enhances Ca2+ currents via L-type, voltage-gated CaV 1.2 channels, strengthening cardiac contraction. The signalling via β-adrenergic receptors (β-ARs) involves elevation of cyclic AMP (cAMP) levels and activation of protein kinase A (PKA). However, how PKA affects the channel remains controversial. Recent studies in heterologous systems and genetically engineered mice stress the importance of the post-translational proteolytic truncation of the distal C-terminus (dCT) of the main (α1C ) subunit. Here, we successfully reconstituted the cAMP/PKA regulation of the dCT-truncated CaV 1.2 in Xenopus oocytes, which previously failed with the non-truncated α1C . cAMP and the purified catalytic subunit of PKA, PKA-CS, injected into intact oocytes, enhanced CaV 1.2 currents by ∼40% (rabbit α1C ) to ∼130% (mouse α1C ). PKA blockers were used to confirm specificity and the need for dissociation of the PKA holoenzyme. The regulation persisted in the absence of the clipped dCT (as a separate protein), the A kinase-anchoring protein AKAP15, and the phosphorylation sites S1700 and T1704, previously proposed as essential for the PKA effect. The CaV β2b subunit was not involved, as suggested by extensive mutagenesis. Using deletion/chimeric mutagenesis, we have identified the initial segment of the cardiac long-N-terminal isoform of α1C as a previously unrecognized essential element involved in PKA regulation. We propose that the observed regulation, that exclusively involves the α1C subunit, is one of several mechanisms underlying the overall PKA action on CaV 1.2 in the heart. We hypothesize that PKA is acting on CaV 1.2, in part, by affecting a structural 'scaffold' comprising the interacting cytosolic N- and C-termini of α1C .
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Affiliation(s)
- Shimrit Oz
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Ines Pankonien
- Max Delbrück Center for Molecular Medicine (MDC), D-13092, and the German Centre for Cardiovascular Research (DZHK) partner site, Berlin, Germany
| | - Anouar Belkacemi
- Experimentelle und Klinische Pharmakologie und Toxikologie, Universität des Saarlandes, 66421, Homburg, Germany
| | - Veit Flockerzi
- Experimentelle und Klinische Pharmakologie und Toxikologie, Universität des Saarlandes, 66421, Homburg, Germany
| | - Enno Klussmann
- Max Delbrück Center for Molecular Medicine (MDC), D-13092, and the German Centre for Cardiovascular Research (DZHK) partner site, Berlin, Germany
| | - Hannelore Haase
- Max Delbrück Center for Molecular Medicine (MDC), D-13092, and the German Centre for Cardiovascular Research (DZHK) partner site, Berlin, Germany
| | - Nathan Dascal
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, 6997801, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, 6997801, Israel
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Tykocki NR, Boerman EM, Jackson WF. Smooth Muscle Ion Channels and Regulation of Vascular Tone in Resistance Arteries and Arterioles. Compr Physiol 2017; 7:485-581. [PMID: 28333380 DOI: 10.1002/cphy.c160011] [Citation(s) in RCA: 212] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Vascular tone of resistance arteries and arterioles determines peripheral vascular resistance, contributing to the regulation of blood pressure and blood flow to, and within the body's tissues and organs. Ion channels in the plasma membrane and endoplasmic reticulum of vascular smooth muscle cells (SMCs) in these blood vessels importantly contribute to the regulation of intracellular Ca2+ concentration, the primary determinant of SMC contractile activity and vascular tone. Ion channels provide the main source of activator Ca2+ that determines vascular tone, and strongly contribute to setting and regulating membrane potential, which, in turn, regulates the open-state-probability of voltage gated Ca2+ channels (VGCCs), the primary source of Ca2+ in resistance artery and arteriolar SMCs. Ion channel function is also modulated by vasoconstrictors and vasodilators, contributing to all aspects of the regulation of vascular tone. This review will focus on the physiology of VGCCs, voltage-gated K+ (KV) channels, large-conductance Ca2+-activated K+ (BKCa) channels, strong-inward-rectifier K+ (KIR) channels, ATP-sensitive K+ (KATP) channels, ryanodine receptors (RyRs), inositol 1,4,5-trisphosphate receptors (IP3Rs), and a variety of transient receptor potential (TRP) channels that contribute to pressure-induced myogenic tone in resistance arteries and arterioles, the modulation of the function of these ion channels by vasoconstrictors and vasodilators, their role in the functional regulation of tissue blood flow and their dysfunction in diseases such as hypertension, obesity, and diabetes. © 2017 American Physiological Society. Compr Physiol 7:485-581, 2017.
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Affiliation(s)
- Nathan R Tykocki
- Department of Pharmacology, University of Vermont, Burlington, Vermont, USA
| | - Erika M Boerman
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri, USA
| | - William F Jackson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan, USA
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Minobe E, Mori MX, Kameyama M. Calmodulin and ATP support activity of the Cav1.2 channel through dynamic interactions with the channel. J Physiol 2017; 595:2465-2477. [PMID: 28130847 PMCID: PMC5390892 DOI: 10.1113/jp273736] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 01/06/2017] [Indexed: 11/08/2022] Open
Abstract
Key points Cav1.2 channels maintain activity through interactions with calmodulin (CaM). In this study, activities of the Cav1.2 channel (α1C) and of mutant‐derivatives, C‐terminal deleted (α1CΔ) and α1CΔ linked with CaM (α1CΔCaM), were compared in the inside‐out mode. α1CΔ with CaM, but not without CaM, and α1CΔCaM were active, suggesting that CaM induced channel activity through a dynamic interaction with the channel, even without the distal C‐tail. ATP induced α1C activity with CaM and enhanced activity of the mutant channels. Okadaic acid mimicked the effect of ATP on the wildtype but not mutant channels. These results supported the hypothesis that CaM and ATP maintain activity of Cav1.2 channels through their dynamic interactions. ATP effects involve mechanisms both related and unrelated to channel phosphorylation. CaM‐linked channels are useful tools for investigating Cav1.2 channels in the inside‐out mode; the fast run‐down is prevented by only ATP and the slow run‐down is nearly absent.
Abstract Calmodulin (CaM) plays a critical role in regulation of Cav1.2 Ca2+ channels. CaM binds to the channel directly, maintaining channel activity and regulating it in a Ca2+‐dependent manner. To explore the molecular mechanisms involved, we compared the activity of the wildtype channel (α1C) and mutant derivatives, C‐terminal deleted (α1C∆) and α1C∆ linked to CaM (α1C∆CaM). These were co‐expressed with β2a and α2δ subunits in HEK293 cells. In the inside‐out mode, α1C and α1C∆ showed minimal open‐probabilities in a basic internal solution (run‐down), whereas α1C∆ with CaM and α1C∆CaM maintained detectable channel activity, confirming that CaM was necessary, but not sufficient, for channel activity. Previously, we reported that ATP was required to maintain channel activity of α1C. Unlike α1C, the mutant channels did not require ATP for activation in the early phase (3–5 min). However, α1C∆ with CaM + ATP and α1C∆CaM with ATP maintained activity, even in the late phase (after 7–9 min). These results suggested that CaM and ATP interacted dynamically with the proximal C‐terminal tail of the channel and, thereby, produced channel activity. In addition, okadaic acid, a protein phosphatase inhibitor, could substitute for the effects of ATP on α1C but not on the mutant channels. These results supported the hypothesis that CaM and ATP maintain activity of Cav1.2 channels, further indicating that ATP has dual effects. One maintains phosphorylation of the channel and the other becomes apparent when the distal carboxyl‐terminal tail is removed. Cav1.2 channels maintain activity through interactions with calmodulin (CaM). In this study, activities of the Cav1.2 channel (α1C) and of mutant‐derivatives, C‐terminal deleted (α1CΔ) and α1CΔ linked with CaM (α1CΔCaM), were compared in the inside‐out mode. α1CΔ with CaM, but not without CaM, and α1CΔCaM were active, suggesting that CaM induced channel activity through a dynamic interaction with the channel, even without the distal C‐tail. ATP induced α1C activity with CaM and enhanced activity of the mutant channels. Okadaic acid mimicked the effect of ATP on the wildtype but not mutant channels. These results supported the hypothesis that CaM and ATP maintain activity of Cav1.2 channels through their dynamic interactions. ATP effects involve mechanisms both related and unrelated to channel phosphorylation. CaM‐linked channels are useful tools for investigating Cav1.2 channels in the inside‐out mode; the fast run‐down is prevented by only ATP and the slow run‐down is nearly absent.
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Affiliation(s)
- Etsuko Minobe
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, 890-8544, Japan
| | - Masayuki X Mori
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, 615-8510, Japan
| | - Masaki Kameyama
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, 890-8544, Japan
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Abstract
Unique to striated muscle cells, transverse tubules (t-tubules) are membrane organelles that consist of sarcolemma penetrating into the myocyte interior, forming a highly branched and interconnected network. Mature t-tubule networks are found in mammalian ventricular cardiomyocytes, with the transverse components of t-tubules occurring near sarcomeric z-discs. Cardiac t-tubules contain membrane microdomains enriched with ion channels and signaling molecules. The microdomains serve as key signaling hubs in regulation of cardiomyocyte function. Dyad microdomains formed at the junctional contact between t-tubule membrane and neighboring sarcoplasmic reticulum are critical in calcium signaling and excitation-contraction coupling necessary for beat-to-beat heart contraction. In this review, we provide an overview of the current knowledge in gross morphology and structure, membrane and protein composition, and function of the cardiac t-tubule network. We also review in detail current knowledge on the formation of functional membrane subdomains within t-tubules, with a particular focus on the cardiac dyad microdomain. Lastly, we discuss the dynamic nature of t-tubules including membrane turnover, trafficking of transmembrane proteins, and the life cycles of membrane subdomains such as the cardiac BIN1-microdomain, as well as t-tubule remodeling and alteration in diseased hearts. Understanding cardiac t-tubule biology in normal and failing hearts is providing novel diagnostic and therapeutic opportunities to better treat patients with failing hearts.
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Affiliation(s)
- TingTing Hong
- Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California; and Department of Medicine, University of California Los Angeles, Los Angeles, California
| | - Robin M Shaw
- Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California; and Department of Medicine, University of California Los Angeles, Los Angeles, California
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Tamayo M, Manzanares E, Bas M, Martín-Nunes L, Val-Blasco A, Jesús Larriba M, Fernández-Velasco M, Delgado C. Calcitriol (1,25-dihydroxyvitamin D3) increases L-type calcium current via protein kinase A signaling and modulates calcium cycling and contractility in isolated mouse ventricular myocytes. Heart Rhythm 2017; 14:432-439. [DOI: 10.1016/j.hrthm.2016.12.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Indexed: 11/26/2022]
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Qian H, Patriarchi T, Price JL, Matt L, Lee B, Nieves-Cintrón M, Buonarati OR, Chowdhury D, Nanou E, Nystoriak MA, Catterall WA, Poomvanicha M, Hofmann F, Navedo MF, Hell JW. Phosphorylation of Ser1928 mediates the enhanced activity of the L-type Ca2+ channel Cav1.2 by the β2-adrenergic receptor in neurons. Sci Signal 2017; 10:10/463/eaaf9659. [PMID: 28119465 DOI: 10.1126/scisignal.aaf9659] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The L-type Ca2+ channel Cav1.2 controls multiple functions throughout the body including heart rate and neuronal excitability. It is a key mediator of fight-or-flight stress responses triggered by a signaling pathway involving β-adrenergic receptors (βARs), cyclic adenosine monophosphate (cAMP), and protein kinase A (PKA). PKA readily phosphorylates Ser1928 in Cav1.2 in vitro and in vivo, including in rodents and humans. However, S1928A knock-in (KI) mice have normal PKA-mediated L-type channel regulation in the heart, indicating that Ser1928 is not required for regulation of cardiac Cav1.2 by PKA in this tissue. We report that augmentation of L-type currents by PKA in neurons was absent in S1928A KI mice. Furthermore, S1928A KI mice failed to induce long-term potentiation in response to prolonged theta-tetanus (PTT-LTP), a form of synaptic plasticity that requires Cav1.2 and enhancement of its activity by the β2-adrenergic receptor (β2AR)-cAMP-PKA cascade. Thus, there is an unexpected dichotomy in the control of Cav1.2 by PKA in cardiomyocytes and hippocampal neurons.
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Affiliation(s)
- Hai Qian
- Department of Pharmacology, University of Iowa, Iowa City, IA 52242-1109, USA
| | - Tommaso Patriarchi
- Department of Pharmacology, University of California, Davis, CA 95616-8636, USA
| | - Jennifer L Price
- Department of Pharmacology, University of California, Davis, CA 95616-8636, USA
| | - Lucas Matt
- Department of Pharmacology, University of California, Davis, CA 95616-8636, USA
| | - Boram Lee
- Department of Pharmacology, University of California, Davis, CA 95616-8636, USA
| | | | - Olivia R Buonarati
- Department of Pharmacology, University of California, Davis, CA 95616-8636, USA
| | | | - Evanthia Nanou
- Department of Pharmacology, University of Washington, Seattle, WA 98195-7280, USA
| | - Matthew A Nystoriak
- Department of Pharmacology, University of California, Davis, CA 95616-8636, USA
| | - William A Catterall
- Department of Pharmacology, University of Washington, Seattle, WA 98195-7280, USA
| | - Montatip Poomvanicha
- Department of Pharmacology and Toxicology, Technical University of Munich, D-80802 Munich, Germany
| | - Franz Hofmann
- Department of Pharmacology and Toxicology, Technical University of Munich, D-80802 Munich, Germany
| | - Manuel F Navedo
- Department of Pharmacology, University of California, Davis, CA 95616-8636, USA.
| | - Johannes W Hell
- Department of Pharmacology, University of Iowa, Iowa City, IA 52242-1109, USA. .,Department of Pharmacology, University of California, Davis, CA 95616-8636, USA
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Enhanced effect of VEGF165 on L-type calcium currents in guinea-pig cardiac ventricular myocytes. Biomed Pharmacother 2017; 85:697-703. [DOI: 10.1016/j.biopha.2016.11.082] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 11/09/2016] [Accepted: 11/18/2016] [Indexed: 02/08/2023] Open
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Llano-Diez M, Sinclair J, Yamada T, Zong M, Fauconnier J, Zhang SJ, Katz A, Jardemark K, Westerblad H, Andersson DC, Lanner JT. The Role of Reactive Oxygen Species in β-Adrenergic Signaling in Cardiomyocytes from Mice with the Metabolic Syndrome. PLoS One 2016; 11:e0167090. [PMID: 27907040 PMCID: PMC5131978 DOI: 10.1371/journal.pone.0167090] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 11/07/2016] [Indexed: 12/20/2022] Open
Abstract
The metabolic syndrome is associated with prolonged stress and hyperactivity of the sympathetic nervous system and afflicted subjects are prone to develop cardiovascular disease. Under normal conditions, the cardiomyocyte response to acute β-adrenergic stimulation partly depends on increased production of reactive oxygen species (ROS). Here we investigated the interplay between beta-adrenergic signaling, ROS and cardiac contractility using freshly isolated cardiomyocytes and whole hearts from two mouse models with the metabolic syndrome (high-fat diet and ob/ob mice). We hypothesized that cardiomyocytes of mice with the metabolic syndrome would experience excessive ROS levels that trigger cellular dysfunctions. Fluorescent dyes and confocal microscopy were used to assess mitochondrial ROS production, cellular Ca2+ handling and contractile function in freshly isolated adult cardiomyocytes. Immunofluorescence, western blot and enzyme assay were used to study protein biochemistry. Unexpectedly, our results point towards decreased cardiac ROS signaling in a stable, chronic phase of the metabolic syndrome because: β-adrenergic-induced increases in the amplitude of intracellular Ca2+ signals were insensitive to antioxidant treatment; mitochondrial ROS production showed decreased basal rate and smaller response to β-adrenergic stimulation. Moreover, control hearts and hearts with the metabolic syndrome showed similar basal levels of ROS-mediated protein modification, but only control hearts showed increases after β-adrenergic stimulation. In conclusion, in contrast to the situation in control hearts, the cardiomyocyte response to acute β-adrenergic stimulation does not involve increased mitochondrial ROS production in a stable, chronic phase of the metabolic syndrome. This can be seen as a beneficial adaptation to prevent excessive ROS levels.
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Affiliation(s)
- Monica Llano-Diez
- Karolinska Institutet, Department of Physiology & Pharmacology, Stockholm, Sweden
| | - Jon Sinclair
- Karolinska Institutet, Department of Physiology & Pharmacology, Stockholm, Sweden
| | - Takashi Yamada
- Karolinska Institutet, Department of Physiology & Pharmacology, Stockholm, Sweden
| | - Mei Zong
- Karolinska University Hospital, Rheumatology unit, CMM, Stockholm Sweden
| | - Jeremy Fauconnier
- Karolinska Institutet, Department of Physiology & Pharmacology, Stockholm, Sweden
| | - Shi-Jin Zhang
- Karolinska Institutet, Department of Physiology & Pharmacology, Stockholm, Sweden
| | - Abram Katz
- Karolinska Institutet, Department of Physiology & Pharmacology, Stockholm, Sweden
| | - Kent Jardemark
- Karolinska Institutet, Department of Physiology & Pharmacology, Stockholm, Sweden
| | - Håkan Westerblad
- Karolinska Institutet, Department of Physiology & Pharmacology, Stockholm, Sweden
| | | | - Johanna T. Lanner
- Karolinska Institutet, Department of Physiology & Pharmacology, Stockholm, Sweden
- * E-mail:
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Loss of β-adrenergic-stimulated phosphorylation of CaV1.2 channels on Ser1700 leads to heart failure. Proc Natl Acad Sci U S A 2016; 113:E7976-E7985. [PMID: 27864509 DOI: 10.1073/pnas.1617116113] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
L-type Ca2+ currents conducted by voltage-gated calcium channel 1.2 (CaV1.2) initiate excitation-contraction coupling in the heart, and altered expression of CaV1.2 causes heart failure in mice. Here we show unexpectedly that reducing β-adrenergic regulation of CaV1.2 channels by mutation of a single PKA site, Ser1700, in the proximal C-terminal domain causes reduced contractile function, cardiac hypertrophy, and heart failure without changes in expression, localization, or function of the CaV1.2 protein in the mutant mice (SA mice). These deficits were aggravated with aging. Dual mutation of Ser1700 and a nearby casein-kinase II site (Thr1704) caused accelerated hypertrophy, heart failure, and death in mice with these mutations (STAA mice). Cardiac hypertrophy was increased by voluntary exercise and by persistent β-adrenergic stimulation. PKA expression was increased, and PKA sites Ser2808 in ryanodine receptor type-2, Ser16 in phospholamban, and Ser23/24 in troponin-I were hyperphosphorylated in SA mice, whereas phosphorylation of substrates for calcium/calmodulin-dependent protein kinase II was unchanged. The Ca2+ pool in the sarcoplasmic reticulum was increased, the activity of calcineurin was elevated, and calcineurin inhibitors improved contractility and ameliorated cardiac hypertrophy. Cardio-specific expression of the SA mutation also caused reduced contractility and hypertrophy. These results suggest engagement of compensatory mechanisms, which initially may enhance the contractility of individual myocytes but eventually contribute to an increased sensitivity to cardiovascular stress and to heart failure in vivo. Our results demonstrate that normal regulation of CaV1.2 channels by phosphorylation of Ser1700 in cardiomyocytes is required for cardiovascular homeostasis and normal physiological regulation in vivo.
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Huang J, Zamponi GW. Regulation of voltage gated calcium channels by GPCRs and post-translational modification. Curr Opin Pharmacol 2016; 32:1-8. [PMID: 27768908 DOI: 10.1016/j.coph.2016.10.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 10/03/2016] [Accepted: 10/04/2016] [Indexed: 01/31/2023]
Abstract
Calcium entry via voltage gated calcium channels mediates a wide range of physiological functions, whereas calcium channel dysregulation has been associated with numerous pathophysiological conditions. There are myriad cell signaling pathways that act on voltage gated calcium channels to fine tune their activities and to regulate their cell surface expression. These regulatory mechanisms include the activation of G protein-coupled receptors and downstream phosphorylation events, and their control over calcium channel trafficking through direct physical interactions. Calcium channels also undergo post-translational modifications that alter both function and density of the channels in the plasma membrane. Here we focus on select aspects of these regulatory mechanisms and highlight recent developments.
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Affiliation(s)
- Junting Huang
- Department of Physiology and Pharmacology, Alberta Children's Hospital Research Institute and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Gerald W Zamponi
- Department of Physiology and Pharmacology, Alberta Children's Hospital Research Institute and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada.
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Catterall WA. Regulation of Cardiac Calcium Channels in the Fight-or-Flight Response. Curr Mol Pharmacol 2016; 8:12-21. [PMID: 25966697 DOI: 10.2174/1874467208666150507103417] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 02/17/2015] [Accepted: 04/20/2015] [Indexed: 11/22/2022]
Abstract
Intracellular calcium transients generated by activation of voltage-gated calcium (CaV) channels generate local signals, which initiate physiological processes such as secretion, synaptic transmission, and excitation-contraction coupling. Regulation of calcium entry through CaV channels is crucial for control of these physiological processes. In this article, I review experimental results that have emerged over several years showing that cardiac CaV1.2 channels form a local signaling complex, in which their proteolytically processed distal C-terminal domain, an A-Kinase Anchoring Protein, and cyclic AMP-dependent protein kinase (PKA) interact directly with the transmembrane core of the ion channel through the proximal C-terminal domain. This signaling complex is the substrate for β-adrenergic up-regulation of the CaV1.2 channel in the heart during the fight-or-flight response. Protein phosphorylation of two sites at the interface between the distal and proximal C-terminal domains contributes importantly to control of basal CaV1.2 channel activity, and phosphorylation of Ser1700 by PKA at that interface up-regulates CaV1.2 activity in response to β-adrenergic signaling. Thus, the intracellular C-terminal domain of CaV1.2 channels serves as a signaling platform, mediating beat-to-beat physiological regulation of channel activity and up-regulation by β-adrenergic signaling in the fight-or-flight response.
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Affiliation(s)
- William A Catterall
- Department of Pharmacology, Box 357280, University of Washington, Seattle, WA 98195-7280.
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K(ATP) channel gain-of-function leads to increased myocardial L-type Ca(2+) current and contractility in Cantu syndrome. Proc Natl Acad Sci U S A 2016; 113:6773-8. [PMID: 27247394 DOI: 10.1073/pnas.1606465113] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Cantu syndrome (CS) is caused by gain-of-function (GOF) mutations in genes encoding pore-forming (Kir6.1, KCNJ8) and accessory (SUR2, ABCC9) KATP channel subunits. We show that patients with CS, as well as mice with constitutive (cGOF) or tamoxifen-induced (icGOF) cardiac-specific Kir6.1 GOF subunit expression, have enlarged hearts, with increased ejection fraction and increased contractility. Whole-cell voltage-clamp recordings from cGOF or icGOF ventricular myocytes (VM) show increased basal L-type Ca(2+) current (LTCC), comparable to that seen in WT VM treated with isoproterenol. Mice with vascular-specific expression (vGOF) show left ventricular dilation as well as less-markedly increased LTCC. Increased LTCC in KATP GOF models is paralleled by changes in phosphorylation of the pore-forming α1 subunit of the cardiac voltage-gated calcium channel Cav1.2 at Ser1928, suggesting enhanced protein kinase activity as a potential link between increased KATP current and CS cardiac pathophysiology.
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Yu L, Xu J, Minobe E, Kameyama A, Yang L, Feng R, Hao L, Kameyama M. Role of protein phosphatases in the run down of guinea pig cardiac Cav1.2 Ca2+ channels. Am J Physiol Cell Physiol 2016; 310:C773-9. [DOI: 10.1152/ajpcell.00199.2015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 01/05/2016] [Indexed: 12/26/2022]
Abstract
This study aimed to investigate protein phosphatases involved in the run down of Cav1.2 Ca2+ channels. Single ventricular myocytes obtained from adult guinea pig hearts were used to record Ca2+ channel currents with the patch-clamp technique. Calmodulin (CaM) and ATP were used to restore channel activity in inside-out patches. Inhibitors of protein phosphatases were applied to investigate the role of phosphatases. The specific protein phosphatase type 1 (PP1) inhibitor (PP1 inhibitor-2) and protein phosphatase type 2A (PP2A) inhibitor (fostriecin) abolished the slow run down of Cav1.2 Ca2+ channels, which was evident as the time-dependent attenuation of the reversing effect of CaM/ATP on the run down. However, protein phosphatase type 2B (PP2B, calcineurin) inhibitor cyclosporine A together with cyclophilin A had no effect on the channel run down. Furthermore, PP1 inhibitor-2 mainly prolonged the open time constants of the channel, specifically, the slow open time. Fostriecin primarily shortened the slow close time constants. Our data suggest that PP1 and PP2A were involved in the slow phase of Cav1.2 Ca2+ channel run down. In addition, they exerted different effects on the open-close kinetics of the channel. All above support the view that PP1 and PP2A may dephosphorylate distinct phosphorylation sites on the Cav1.2 Ca2+ channel.
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Affiliation(s)
- Lifeng Yu
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, China; and
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Jianjun Xu
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Etsuko Minobe
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Asako Kameyama
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Lei Yang
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Rui Feng
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, China; and
| | - Liying Hao
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, China; and
| | - Masaki Kameyama
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
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Patriarchi T, Qian H, Di Biase V, Malik ZA, Chowdhury D, Price JL, Hammes EA, Buonarati OR, Westenbroek RE, Catterall WA, Hofmann F, Xiang YK, Murphy GG, Chen CY, Navedo MF, Hell JW. Phosphorylation of Cav1.2 on S1928 uncouples the L-type Ca2+ channel from the β2 adrenergic receptor. EMBO J 2016; 35:1330-45. [PMID: 27103070 DOI: 10.15252/embj.201593409] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Accepted: 03/24/2016] [Indexed: 01/07/2023] Open
Abstract
Agonist-triggered downregulation of β-adrenergic receptors (ARs) constitutes vital negative feedback to prevent cellular overexcitation. Here, we report a novel downregulation of β2AR signaling highly specific for Cav1.2. We find that β2-AR binding to Cav1.2 residues 1923-1942 is required for β-adrenergic regulation of Cav1.2. Despite the prominence of PKA-mediated phosphorylation of Cav1.2 S1928 within the newly identified β2AR binding site, its physiological function has so far escaped identification. We show that phosphorylation of S1928 displaces the β2AR from Cav1.2 upon β-adrenergic stimulation rendering Cav1.2 refractory for several minutes from further β-adrenergic stimulation. This effect is lost in S1928A knock-in mice. Although AMPARs are clustered at postsynaptic sites like Cav1.2, β2AR association with and regulation of AMPARs do not show such dissociation. Accordingly, displacement of the β2AR from Cav1.2 is a uniquely specific desensitization mechanism of Cav1.2 regulation by highly localized β2AR/cAMP/PKA/S1928 signaling. The physiological implications of this mechanism are underscored by our finding that LTP induced by prolonged theta tetanus (PTT-LTP) depends on Cav1.2 and its regulation by channel-associated β2AR.
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Affiliation(s)
| | - Hai Qian
- Department of Pharmacology, University of Iowa, Iowa City, IA, USA
| | | | - Zulfiquar A Malik
- Department of Pharmacology, University of California, Davis, CA, USA Department of Pharmacology, University of Iowa, Iowa City, IA, USA
| | | | - Jennifer L Price
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Erik A Hammes
- Department of Pharmacology, University of California, Davis, CA, USA
| | | | | | | | - Franz Hofmann
- Department of Pharmacology and Toxicology, Technical University of Munich, Munich, Germany
| | - Yang K Xiang
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Geoffrey G Murphy
- Department of Molecular & Integrative Physiology, Molecular & Behavioral Neuroscience Institute University of Michigan, Ann Arbor, MI, USA
| | - Chao-Ye Chen
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Manuel F Navedo
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Johannes W Hell
- Department of Pharmacology, University of California, Davis, CA, USA Department of Pharmacology, University of Iowa, Iowa City, IA, USA
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Fu Y, Shaw SA, Naami R, Vuong CL, Basheer WA, Guo X, Hong T. Isoproterenol Promotes Rapid Ryanodine Receptor Movement to Bridging Integrator 1 (BIN1)-Organized Dyads. Circulation 2016; 133:388-97. [PMID: 26733606 DOI: 10.1161/circulationaha.115.018535] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 12/21/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND The key pathophysiology of human acquired heart failure is impaired calcium transient, which is initiated at dyads consisting of ryanodine receptors (RyRs) at sarcoplasmic reticulum apposing CaV1.2 channels at t-tubules. Sympathetic tone regulates myocardial calcium transients through β-adrenergic receptor (β-AR)-mediated phosphorylation of dyadic proteins. Phosphorylated RyRs (P-RyR) have increased calcium sensitivity and open probability, amplifying calcium transient at a cost of receptor instability. Given that bridging integrator 1 (BIN1) organizes t-tubule microfolds and facilitates CaV1.2 delivery, we explored whether β-AR-regulated RyRs are also affected by BIN1. METHODS AND RESULTS Isolated adult mouse hearts or cardiomyocytes were perfused for 5 minutes with the β-AR agonist isoproterenol (1 µmol/L) or the blockers CGP+ICI (baseline). Using biochemistry and superresolution fluorescent imaging, we identified that BIN1 clusters P-RyR and CaV1.2. Acute β-AR activation increases coimmunoprecipitation between P-RyR and cardiac spliced BIN1+13+17 (with exons 13 and 17). Isoproterenol redistributes BIN1 to t-tubules, recruiting P-RyRs and improving the calcium transient. In cardiac-specific Bin1 heterozygote mice, isoproterenol fails to concentrate BIN1 to t-tubules, impairing P-RyR recruitment. The resultant accumulation of uncoupled P-RyRs increases the incidence of spontaneous calcium release. In human hearts with end-stage ischemic cardiomyopathy, we find that BIN1 is also 50% reduced, with diminished P-RyR association with BIN1. CONCLUSIONS On β-AR activation, reorganization of BIN1-induced microdomains recruits P-RyR into dyads, increasing the calcium transient while preserving electric stability. When BIN1 is reduced as in human acquired heart failure, acute stress impairs microdomain formation, limiting contractility and promoting arrhythmias.
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Affiliation(s)
- Ying Fu
- From Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (Y.F., S.A.S., R.N., C.L.V., W.A.B., T.H.); Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA (X.G.); and Departments of Medicine, Cedars-Sinai Medical Center and UCLA, Los Angeles, CA (T.H.)
| | - Seiji A Shaw
- From Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (Y.F., S.A.S., R.N., C.L.V., W.A.B., T.H.); Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA (X.G.); and Departments of Medicine, Cedars-Sinai Medical Center and UCLA, Los Angeles, CA (T.H.)
| | - Robert Naami
- From Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (Y.F., S.A.S., R.N., C.L.V., W.A.B., T.H.); Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA (X.G.); and Departments of Medicine, Cedars-Sinai Medical Center and UCLA, Los Angeles, CA (T.H.)
| | - Caresse L Vuong
- From Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (Y.F., S.A.S., R.N., C.L.V., W.A.B., T.H.); Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA (X.G.); and Departments of Medicine, Cedars-Sinai Medical Center and UCLA, Los Angeles, CA (T.H.)
| | - Wassim A Basheer
- From Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (Y.F., S.A.S., R.N., C.L.V., W.A.B., T.H.); Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA (X.G.); and Departments of Medicine, Cedars-Sinai Medical Center and UCLA, Los Angeles, CA (T.H.)
| | - Xiuqing Guo
- From Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (Y.F., S.A.S., R.N., C.L.V., W.A.B., T.H.); Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA (X.G.); and Departments of Medicine, Cedars-Sinai Medical Center and UCLA, Los Angeles, CA (T.H.)
| | - TingTing Hong
- From Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (Y.F., S.A.S., R.N., C.L.V., W.A.B., T.H.); Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA (X.G.); and Departments of Medicine, Cedars-Sinai Medical Center and UCLA, Los Angeles, CA (T.H.).
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Calmodulin kinase II inhibitor regulates calcium homeostasis changes caused by acute β-adrenergic receptor agonist stimulation in mouse ventricular myocytes. In Vitro Cell Dev Biol Anim 2015; 52:156-62. [PMID: 26542171 DOI: 10.1007/s11626-015-9967-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 10/15/2015] [Indexed: 01/20/2023]
Abstract
Ca(2+)/calmodulin-dependent kinase II (CaMKII) is an important regulatory molecule under chronic β-adrenergic receptor agonist stimulation but cardiac diseases also occur when β-adrenergic elevated acutely in the circulation, of which the most harmful is lethal arrhythmia. The purpose of this study was to explore the effects of acute isoproterenol (ISO) stimulation on intracellular calcium handling and evaluate whether CaMKII inhibitor may change the effects caused by isoproterenol. Mouse ventricular myocytes were acutely isolated by enzymatic method and divided into four groups: control group, ISO group, KN-93 group, ISO + KN-93 group. The whole-cell patch clamp was used to study the effect of ISO and KN-93 on L-type calcium current (IL-Ca) in isolated ventricular myocytes. The technology of laser scanning confocal microscopy was used to record cardiomyocyte calcium transients after ISO and KN-93 were used. ISO significantly increased current density of IL-Ca (p < 0.01) and decreased the half activation voltage (p < 0.01), half inactivation voltage (p < 0.01), and the recovery time constant (p < 0.01). In the presence of CaMKII inhibitor, KN-93 decreased the increased current density of IL-Ca (p < 0.05), increased the reduced half activation voltage caused by ISO (p < 0.01), and prolonged the shortened recovery time constant caused by ISO (p < 0.01). In addition, KN-93 alone can change the activation, inactivation, and recovery kinetics of L-type calcium channels. Moreover, ISO significantly increased the Ca(2+) transient amplitude during both stimulation frequencies (0.5 Hz: p < 0.01, 1 Hz: p < 0.01) and was easy to induce calcium disorders; in the presence of KN-93, these changes were weakened (0.5 Hz: p < 0.05, 1 Hz: p < 0.05). Therefore, changes of the calcium homeostasis in cardiomyocytes caused by ISO can be adjusted by KN-93, thus KN-93 plays a vital role in regulating calcium homeostasis changes caused by ISO.
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50
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Affiliation(s)
- William A Catterall
- Department of Pharmacology, University of Washington, Seattle, Washington 98195-7280.
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