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Fujii S, Kobayashi S, Chang Y, Nawata J, Yoshitomi R, Tanaka S, Kohno M, Nakamura Y, Ishiguchi H, Suetomi T, Uchinoumi H, Oda T, Okuda S, Okamura T, Yamamoto T, Yano M. RyR2-targeting therapy prevents left ventricular remodeling and ventricular tachycardia in post-infarction heart failure. J Mol Cell Cardiol 2023; 178:36-50. [PMID: 36963751 DOI: 10.1016/j.yjmcc.2023.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 03/15/2023] [Accepted: 03/21/2023] [Indexed: 03/26/2023]
Abstract
BACKGROUND Dantrolene binds to the Leu601-Cys620 region of the N-terminal domain of cardiac ryanodine receptor (RyR2), which corresponds to the Leu590-Cys609 region of the skeletal ryanodine receptor, and suppresses diastolic Ca2+ leakage through RyR2. OBJECTIVE We investigated whether the chronic administration of dantrolene prevented left ventricular (LV) remodeling and ventricular tachycardia (VT) after myocardial infarction (MI) by the same mechanism with the mutation V3599K of RyR2, which indicated that the inhibition of diastolic Ca2+ leakage occurred by enhancing the binding affinity of calmodulin (CaM) to RyR2. METHODS AND RESULTS A left anterior descending coronary artery ligation MI model was developed in mice. Wild-type (WT) were divided into four groups: sham-operated mice (WT-Sham), sham-operated mice treated with dantrolene (WT-Sham-DAN), MI mice (WT-MI), and MI mice treated with dantrolene (WT-MI-DAN). Homozygous V3599K RyR2 knock-in (KI) mice were divided into two groups: sham-operated mice (KI-Sham) and MI mice (KI-MI). The mice were followed for 12 weeks. Survival was significantly higher in the WT-MI-DAN (73%) and KI-MI groups (70%) than the WT-MI group (40%). Echocardiography, pathological tissue, and epinephrine-induced VT studies showed that LV remodeling and VT were prevented in the WT-MI-DAN and KI-MI groups compared to the WT-MI group. An increase in diastolic Ca2+ spark frequency and a decrease in the binding affinity of CaM to the RyR2 were observed at 12 weeks after MI in the WT-MI group, although significant improvements in these values were observed in the WT-MI-DAN and KI-MI groups. CONCLUSIONS Pharmacological or genetic stabilization of RyR2 tetrameric structure improves survival after MI by suppressing LV remodeling and proarrhythmia.
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Affiliation(s)
- Shohei Fujii
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan
| | - Shigeki Kobayashi
- Department of Therapeutic Science for Heart Failure in the Elderly, Yamaguchi University School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan.
| | - Yaowei Chang
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan
| | - Junya Nawata
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan
| | - Ryosuke Yoshitomi
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan
| | - Shinji Tanaka
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan
| | - Michiaki Kohno
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan
| | - Yoshihide Nakamura
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan
| | - Hironori Ishiguchi
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan
| | - Takeshi Suetomi
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan
| | - Hitoshi Uchinoumi
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan
| | - Tetsuro Oda
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan
| | - Shinichi Okuda
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan
| | - Takayuki Okamura
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan
| | - Takeshi Yamamoto
- Department of Laboratory Medicine, Faculty of Health Sciences, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan
| | - Masafumi Yano
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan
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Yano Y, Kobayashi S, Uchida T, Chang Y, Nawata J, Fujii S, Nakamura Y, Suetomi T, Uchinoumi H, Oda T, Yamamoto T, Yano M. Stabilizing cardiac ryanodine receptor with dantrolene treatment prevents left ventricular remodeling in pressure-overloaded heart failure mice. Biochem Biophys Res Commun 2023; 642:175-184. [PMID: 36584481 DOI: 10.1016/j.bbrc.2022.12.063] [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: 11/30/2022] [Revised: 12/14/2022] [Accepted: 12/21/2022] [Indexed: 12/24/2022]
Abstract
Dantrolene (DAN) directly binds to cardiac ryanodine receptor 2 (RyR2) through Leu601-Cys620 in the N-terminal domain and subsequently inhibits diastolic Ca2+ leakage through RyR2. We previously reported that therapy using RyR2 V3599K mutation, which inhibits diastolic Ca2+ leakage by enhancing calmodulin (CaM) binding ability to RyR2, prevents left ventricular (LV) remodeling in transverse aortic constriction (TAC) heart failure. Here, we examined whether chronic administration of DAN prevents LV remodeling in TAC heart failure via the same mechanism as genetic therapy. A pressure-overloaded hypertrophy mouse model was developed using TAC. Wild-type (WT) mice were divided into three groups: sham-operated mice (Sham group), TAC mice (TAC group), and TAC mice treated with DAN (TAC-DAN group, 20 mg/kg/day, i.p.). They were then followed up for 8 weeks. The survival rate was higher in the TAC-DAN group (83%) than in the TAC group (49%), and serial echocardiography studies and pathological tissue analysis showed that LV remodeling was significantly prevented in the TAC-DAN group compared to the TAC group. An increase in the diastolic Ca2+ spark frequency and a decrease in the binding affinity of CaM to RyR2 were observed at 8 weeks in the TAC group but not in the TAC-DAN group. Stabilization of RyR2 with DAN prevented LV remodeling and improved survival after TAC by enhancing CaM binding to RyR2 and inhibiting RyR2-mediated diastolic Ca2+ leakage.
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Affiliation(s)
- Yasutake Yano
- Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Shigeki Kobayashi
- Department of Therapeutic Science for Heart Failure in the Elderly, Yamaguchi University School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan.
| | - Tomoyuki Uchida
- Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Yaowei Chang
- Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Junya Nawata
- Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Shohei Fujii
- Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Yoshihide Nakamura
- Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Takeshi Suetomi
- Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Hitoshi Uchinoumi
- Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Tetsuro Oda
- Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Takeshi Yamamoto
- Department of Laboratory Medicine, Faculty of Health Sciences, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Masafumi Yano
- Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
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Wang YX, Reyes-García J, Di Mise A, Zheng YM. Role of ryanodine receptor 2 and FK506-binding protein 12.6 dissociation in pulmonary hypertension. J Gen Physiol 2023; 155:213798. [PMID: 36625865 PMCID: PMC9836826 DOI: 10.1085/jgp.202213100] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 07/29/2022] [Accepted: 12/19/2022] [Indexed: 01/11/2023] Open
Abstract
Pulmonary hypertension (PH) is a devastating disease characterized by a progressive increase in pulmonary arterial pressure leading to right ventricular failure and death. A major cellular response in this disease is the contraction of smooth muscle cells (SMCs) of the pulmonary vasculature. Cell contraction is determined by the increase in intracellular Ca2+ concentration ([Ca2+]i), which is generated and regulated by various ion channels. Several studies by us and others have shown that ryanodine receptor 2 (RyR2), a Ca2+-releasing channel in the sarcoplasmic reticulum (SR), is an essential ion channel for the control of [Ca2+]i in pulmonary artery SMCs (PASMCs), thereby mediating the sustained vasoconstriction seen in PH. FK506-binding protein 12.6 (FKBP12.6) strongly associates with RyR2 to stabilize its functional activity. FKBP12.6 can be dissociated from RyR2 by a hypoxic stimulus to increase channel function and Ca2+ release, leading to pulmonary vasoconstriction and PH. More specifically, dissociation of the RyR2-FKBP12.6 complex is a consequence of increased mitochondrial ROS generation mediated by the Rieske iron-sulfur protein (RISP) at the mitochondrial complex III after hypoxia. Overall, RyR2/FKBP12.6 dissociation and the corresponding signaling pathway may be an important factor in the development of PH. Novel drugs and biologics targeting RyR2, FKBP12.6, and related molecules may become unique effective therapeutics for PH.
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Affiliation(s)
- Yong-Xiao Wang
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA,Correspondence to Yong-Xiao Wang:
| | - Jorge Reyes-García
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA,Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México,Ciudad de México, México
| | - Annarita Di Mise
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA,Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Yun-Min Zheng
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA,Yun-Min Zheng:
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Wan JF, Wang G, Qin FY, Huang DL, Wang Y, Su AL, Zhang HP, Liu Y, Zeng SY, Wei CL, Cheng YX, Liu J. Z16b, a natural compound from Ganoderma cochlear is a novel RyR2 stabilizer preventing catecholaminergic polymorphic ventricular tachycardia. Acta Pharmacol Sin 2022; 43:2340-2350. [PMID: 35190699 PMCID: PMC9433431 DOI: 10.1038/s41401-022-00870-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 01/17/2022] [Indexed: 01/18/2023] Open
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited, lethal ventricular arrhythmia triggered by catecholamines. Mutations in genes that encode cardiac ryanodine receptor (RyR2) and proteins that regulate RyR2 activity cause enhanced diastolic Ca2+ release (leak) through the RyR2 channels, resulting in CPVT. Current therapies for CPVT are limited. We found that Z16b, a meroterpenoid isolated from Ganoderma cochlear, inhibited Ca2+ spark frequency (CaSF) in R2474S/ + cardiomyocytes in a dose-dependent manner, with an IC50 of 3.2 μM. Z16b also dose-dependently suppressed abnormal post-pacing Ca2+ release events. Intraperitoneal injection (i.p.) of epinephrine and caffeine stimulated sustained ventricular tachycardia in all R2474S/+ mice, while pretreatment with Z16b (0.5 mg/kg, i.p.) prevented ventricular arrhythmia in 9 of 10 mice, and Z16b administration immediately after the onset of VT abolished sVT in 9 of 12 mice. Of translational significance, Z16b significantly inhibited CaSF and abnormal Ca2+ release events in human CPVT iPS-CMs. Mechanistically, Z16b interacts with RyR2, enhancing the "zipping" state of the N-terminal and central domains of RyR2. A molecular docking simulation and point mutation and pulldown assays identified Z16b forms hydrogen bonds with Arg626, His1670, and Gln2126 in RyR2 as a triangle shape that anchors the NTD and CD interaction and thus stabilizes RyR2 in a tight "zipping" conformation. Our findings support that Z16b is a novel RyR2 stabilizer that can prevent CPVT. It may also serve as a lead compound with a new scaffold for the design of safer and more efficient drugs for treating CPVT.
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Affiliation(s)
- Jiang-Fan Wan
- Guangdong Key Laboratory of Genome Stability and Human Disease Prevention, Department of Pathophysiology, School of Medicine, Shenzhen University, Shenzhen, 518000, China
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Gang Wang
- Guangdong Key Laboratory of Genome Stability and Human Disease Prevention, Department of Pathophysiology, School of Medicine, Shenzhen University, Shenzhen, 518000, China
| | - Fu-Ying Qin
- School of Pharmaceutical Sciences, Shenzhen University Health Science Center, Shenzhen, 518000, China
| | - Dan-Ling Huang
- School of Pharmaceutical Sciences, Shenzhen University Health Science Center, Shenzhen, 518000, China
| | - Yan Wang
- Center for Translation Medicine Research and Development, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518000, China
| | - Ai-Ling Su
- Center for Translation Medicine Research and Development, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518000, China
| | - Hai-Ping Zhang
- Center for High Performance Computing, Joint Engineering Research Center for Health Big Data Intelligent Analysis Technology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518000, China
| | - Yang Liu
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510000, China
| | - Shao-Yin Zeng
- Guangdong Provincial key laboratory of South China Structure Heart Disease, Department of Pediatric Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510000, China
| | - Chao-Liang Wei
- Guangdong Key Laboratory of Genome Stability and Human Disease Prevention, Department of Pathophysiology, School of Medicine, Shenzhen University, Shenzhen, 518000, China
| | - Yong-Xian Cheng
- School of Pharmaceutical Sciences, Shenzhen University Health Science Center, Shenzhen, 518000, China.
| | - Jie Liu
- Guangdong Key Laboratory of Genome Stability and Human Disease Prevention, Department of Pathophysiology, School of Medicine, Shenzhen University, Shenzhen, 518000, China.
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Tanaka S, Yamamoto T, Mikawa M, Nawata J, Fujii S, Nakamura Y, Kato T, Fukuda M, Suetomi T, Uchinoumi H, Oda T, Okuda S, Okamura T, Kobayashi S, Yano. M. Stabilization of RyR2 maintains right ventricular function, reduces the development of ventricular arrhythmias, and improves prognosis in pulmonary hypertension. Heart Rhythm 2022; 19:986-997. [DOI: 10.1016/j.hrthm.2022.02.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 01/18/2022] [Accepted: 02/01/2022] [Indexed: 02/01/2023]
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Enhancing calmodulin binding to ryanodine receptor is crucial to limit neuronal cell loss in Alzheimer disease. Sci Rep 2021; 11:7289. [PMID: 33790404 PMCID: PMC8012710 DOI: 10.1038/s41598-021-86822-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 03/16/2021] [Indexed: 12/23/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive neuronal cell loss. Recently, dysregulation of intracellular Ca2+ homeostasis has been suggested as a common proximal cause of neural dysfunction in AD. Here, we investigated (1) the pathogenic role of destabilization of ryanodine receptor (RyR2) in endoplasmic reticulum (ER) upon development of AD phenotypes in AppNL-G-F mice, which harbor three familial AD mutations (Swedish, Beyreuther/Iberian, and Arctic), and (2) the therapeutic effect of enhanced calmodulin (CaM) binding to RyR2. In the neuronal cells from AppNL-G-F mice, CaM dissociation from RyR2 was associated with AD-related phenotypes, i.e. Aβ accumulation, TAU phosphorylation, ER stress, neuronal cell loss, and cognitive dysfunction. Surprisingly, either genetic (by V3599K substitution in RyR2) or pharmacological (by dantrolene) enhancement of CaM binding to RyR2 reversed almost completely the aforementioned AD-related phenotypes, except for Aβ accumulation. Thus, destabilization of RyR2 due to CaM dissociation is most likely an early and fundamental pathogenic mechanism involved in the development of AD. The discovery that neuronal cell loss can be fully prevented simply by stabilizing RyR2 sheds new light on the treatment of AD.
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Shauer A, Shor O, Wei J, Elitzur Y, Kucherenko N, Wang R, Chen SRW, Einav Y, Luria D. Novel RyR2 Mutation (G3118R) Is Associated With Autosomal Recessive Ventricular Fibrillation and Sudden Death: Clinical, Functional, and Computational Analysis. J Am Heart Assoc 2021; 10:e017128. [PMID: 33686871 PMCID: PMC8174198 DOI: 10.1161/jaha.120.017128] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Background The cardiac ryanodine receptor type 2 (RyR2) is a large homotetramer, located in the sarcoplasmic reticulum (SR), which releases Ca2+ from the SR during systole. The molecular mechanism underlying Ca2+ sensing and gating of the RyR2 channel in health and disease is only partially elucidated. Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT1) is the most prevalent syndrome caused by RyR2 mutations. Methods and Results This study involves investigation of a family with 4 cases of ventricular fibrillation and sudden death and physiological tests in HEK 293 cells and normal mode analysis (NMA) computation. We found 4 clinically affected members who were homozygous for a novel RyR2 mutation, G3118R, whereas their heterozygous relatives are asymptomatic. G3118R is located in the periphery of the protein, far from the mutation hotspot regions. HEK293 cells harboring G3118R mutation inhibited Ca2+ release in response to increasing doses of caffeine, but decreased the termination threshold for store‐overload‐induced Ca2+ release, thus increasing the fractional Ca2+ release in response to increasing extracellular Ca2+. NMA showed that G3118 affects RyR2 tetramer in a dose‐dependent manner, whereas in the model of homozygous mutant RyR2, the highest entropic values are assigned to the pore and the central regions of the protein. Conclusions RyR2 G3118R is related to ventricular fibrillation and sudden death in recessive mode of inheritance and has an effect of gain of function on the protein. Despite a peripheral location, it has an allosteric effect on the stability of central and pore regions in a dose‐effect manner.
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Affiliation(s)
- Ayelet Shauer
- Heart Institute Hadassah-Hebrew University Medical Center Jerusalem Israel
| | - Oded Shor
- Heart Institute Hadassah-Hebrew University Medical Center Jerusalem Israel
| | - Jinhong Wei
- Department of Physiology and Pharmacology The Libin Cardiovascular Institute of AlbertaUniversity of Calgary Alberta Canada
| | - Yair Elitzur
- Heart Institute Hadassah-Hebrew University Medical Center Jerusalem Israel
| | - Nataly Kucherenko
- Biochemistry and Molecular Biology Tel Aviv University Tel Aviv Israel
| | - Ruiwu Wang
- Department of Physiology and Pharmacology The Libin Cardiovascular Institute of AlbertaUniversity of Calgary Alberta Canada
| | - S R Wayne Chen
- Department of Physiology and Pharmacology The Libin Cardiovascular Institute of AlbertaUniversity of Calgary Alberta Canada
| | - Yulia Einav
- Faculty of Engineering Holon Institute of Technology Holon Israel
| | - David Luria
- Heart Institute Hadassah-Hebrew University Medical Center Jerusalem Israel
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Wu Y, Zhao W, Ye F, Huang S, Chen H, Zhou R, Jiang W. Tetrandrine attenuates left ventricular dysfunction in rats with myocardial infarction. Exp Ther Med 2020; 21:119. [PMID: 33335582 PMCID: PMC7739846 DOI: 10.3892/etm.2020.9551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 09/16/2020] [Indexed: 12/01/2022] Open
Abstract
The present study aimed to determine whether tetrandrine could attenuate left ventricular dysfunction and remodeling in rats with myocardial infarction. Sprague-Dawley rats were randomly divided into six groups (n=5/group) as follows: i) Healthy control group; ii) sham operation group; iii) myocardial infarction model group; iv) myocardial infarction + low-dose tetrandrine group (10 mg/kg); v) myocardial infarction + medium-dose tetrandrine group (50 mg/kg); and vi) myocardial infarction + high-dose tetrandrine group (80 mg/kg). Left ventricular end-diastolic diameter (LVIDd), left ventricular end-systolic diameter (LVIDs), ejection fraction (EF%) and left ventricular fractional shortening rate (FS%) were measured using ultrasonography. The pathological changes were observed by hematoxylin and eosin (H&E) staining. Left ventricular tissue section TUNEL staining was also performed. Furthermore, the triglyceride (TG), total cholesterol (TC), high density lipoprotein (HDL) and low-density lipoprotein (LDL) in the arterial blood were examined by biochemical testing. Expression levels of intracellular Ca2+ homeostasis-related proteins including ryanodine receptor calmodulin, CaM-dependent protein kinase IIδ, protein kinase A, FK506 binding protein 12.6 were measured using western blot analysis. Ultrasonography results showed that in the myocardial infarction model rats, the levels of LVIDd and LVIDs were significantly higher; however, the levels of EF% and FS% were lower compared with those in the sham operation group, which was alleviated by tetrandrine. H&E results showed that tetrandrine alleviated the pathological characteristics of myocardial infarction model rats. Furthermore, tetrandrine significantly inhibited myocardial cell apoptosis in rats with myocardial infarction. Tetrandrine significantly inhibited the levels of TG, TC and LDL and increased the levels of HDL in the arterial blood of rats with myocardial infarction. These findings revealed that tetrandrine could attenuate left ventricular dysfunction in rats with myocardial infarction, which might be associated with intracellular Ca2+ homeostasis.
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Affiliation(s)
- Youyang Wu
- Department of Cardiology, The Third Clinical Institute Affiliated to Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
| | - Wei Zhao
- Department of Cardiology, The Third Clinical Institute Affiliated to Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
| | - Fanhao Ye
- Department of Cardiology, The Third Clinical Institute Affiliated to Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
| | - Shiwei Huang
- Department of Cardiology, The Third Clinical Institute Affiliated to Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
| | - Hao Chen
- Department of Cardiology, The Third Clinical Institute Affiliated to Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
| | - Rui Zhou
- Department of Cardiology, The Third Clinical Institute Affiliated to Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
| | - Wenbing Jiang
- Department of Cardiology, The Third Clinical Institute Affiliated to Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
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Kohno M, Kobayashi S, Yamamoto T, Yoshitomi R, Kajii T, Fujii S, Nakamura Y, Kato T, Uchinoumi H, Oda T, Okuda S, Watanabe K, Mizukami Y, Yano M. Enhancing calmodulin binding to cardiac ryanodine receptor completely inhibits pressure-overload induced hypertrophic signaling. Commun Biol 2020; 3:714. [PMID: 33244105 PMCID: PMC7691336 DOI: 10.1038/s42003-020-01443-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 10/28/2020] [Indexed: 12/12/2022] Open
Abstract
Cardiac hypertrophy is a well-known major risk factor for poor prognosis in patients with cardiovascular diseases. Dysregulation of intracellular Ca2+ is involved in the pathogenesis of cardiac hypertrophy. However, the precise mechanism underlying cardiac hypertrophy remains elusive. Here, we investigate whether pressure-overload induced hypertrophy can be induced by destabilization of cardiac ryanodine receptor (RyR2) through calmodulin (CaM) dissociation and subsequent Ca2+ leakage, and whether it can be genetically rescued by enhancing the binding affinity of CaM to RyR2. In the very initial phase of pressure-overload induced cardiac hypertrophy, when cardiac contractile function is preserved, reactive oxygen species (ROS)-mediated RyR2 destabilization already occurs in association with relaxation dysfunction. Further, stabilizing RyR2 by enhancing the binding affinity of CaM to RyR2 completely inhibits hypertrophic signaling and improves survival. Our study uncovers a critical missing link between RyR2 destabilization and cardiac hypertrophy.
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Affiliation(s)
- Michiaki Kohno
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Shigeki Kobayashi
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Takeshi Yamamoto
- Faculty of Health Sciences, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, 755-8505, Japan
| | - Ryosuke Yoshitomi
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Toshiro Kajii
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Shohei Fujii
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Yoshihide Nakamura
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Takayoshi Kato
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Hitoshi Uchinoumi
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Tetsuro Oda
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Shinichi Okuda
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Kenji Watanabe
- Institute of Gene Research, Yamaguchi University Science Research Center, Yamaguchi, 755-8505, Japan
| | - Yoichi Mizukami
- Institute of Gene Research, Yamaguchi University Science Research Center, Yamaguchi, 755-8505, Japan
| | - Masafumi Yano
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan.
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10
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Kistamás K, Veress R, Horváth B, Bányász T, Nánási PP, Eisner DA. Calcium Handling Defects and Cardiac Arrhythmia Syndromes. Front Pharmacol 2020; 11:72. [PMID: 32161540 PMCID: PMC7052815 DOI: 10.3389/fphar.2020.00072] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 01/24/2020] [Indexed: 12/13/2022] Open
Abstract
Calcium ions (Ca2+) play a major role in the cardiac excitation-contraction coupling. Intracellular Ca2+ concentration increases during systole and falls in diastole thereby determining cardiac contraction and relaxation. Normal cardiac function also requires perfect organization of the ion currents at the cellular level to drive action potentials and to maintain action potential propagation and electrical homogeneity at the tissue level. Any imbalance in Ca2+ homeostasis of a cardiac myocyte can lead to electrical disturbances. This review aims to discuss cardiac physiology and pathophysiology from the elementary membrane processes that can cause the electrical instability of the ventricular myocytes through intracellular Ca2+ handling maladies to inherited and acquired arrhythmias. Finally, the paper will discuss the current therapeutic approaches targeting cardiac arrhythmias.
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Affiliation(s)
- Kornél Kistamás
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,Division of Cardiovascular Sciences, School of Medical Sciences, University of Manchester, Manchester, United Kingdom
| | - Roland Veress
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Balázs Horváth
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tamás Bányász
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Péter P Nánási
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,Department of Dental Physiology, Faculty of Dentistry, University of Debrecen, Debrecen, Hungary
| | - David A Eisner
- Division of Cardiovascular Sciences, School of Medical Sciences, University of Manchester, Manchester, United Kingdom
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11
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Connell P, Word TA, Wehrens XHT. Targeting pathological leak of ryanodine receptors: preclinical progress and the potential impact on treatments for cardiac arrhythmias and heart failure. Expert Opin Ther Targets 2020; 24:25-36. [PMID: 31869254 DOI: 10.1080/14728222.2020.1708326] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Introduction: Type-2 ryanodine receptor (RyR2) located on the sarcoplasmic reticulum initiate systolic Ca2+ transients within cardiomyocytes. Proper functioning of RyR2 is therefore crucial to the timing and force generated by cardiomyocytes within a healthy heart. Improper intracellular Ca2+ handing secondary to RyR2 dysfunction is associated with a variety of cardiac pathologies including catecholaminergic polymorphic ventricular tachycardia (CPVT), atrial fibrillation (AF), and heart failure (HF). Thus, RyR2 and its associated accessory proteins provide promising drug targets to scientists developing therapeutics for a variety of cardiac pathologies.Areas covered: In this article, we review the role of RyR2 in a variety of cardiac pathologies. We performed a literature search utilizing PubMed and MEDLINE as well as reviewed registries of trials from clinicaltrials.gov from 2010 to 2019 for novel therapeutic approaches that address the cellular mechanisms underlying CPVT, AF, and HF by specifically targeting defective RyR2 channels.Expert opinion: The negative impact of cardiac dysfunction on human health and medical economics are major motivating factors for establishing new and effective therapeutic approaches. Focusing on directly impacting the molecular mechanisms underlying defective Ca2+ handling by RyR2 in HF and arrhythmia has great potential to be translated into novel and innovative therapies.
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Affiliation(s)
- Patrick Connell
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA.,Departments of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Tarah A Word
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA.,Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA
| | - Xander H T Wehrens
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA.,Departments of Pediatrics, Baylor College of Medicine, Houston, TX, USA.,Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA.,Medicine (Cardiology, Baylor College of Medicine, Houston, TX, USA.,Neuroscience, Baylor College of Medicine, Houston, TX, USA.,Center for Space Medicine, Baylor College of Medicine, Houston, TX, USA
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12
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Kajii T, Kobayashi S, Shiba S, Fujii S, Tamitani M, Kohno M, Nakamura Y, Nanno T, Kato T, Okuda S, Uchinoumi H, Oda T, Yamamoto T, Yano M. Dantrolene prevents ventricular tachycardia by stabilizing the ryanodine receptor in pressure- overload induced failing hearts. Biochem Biophys Res Commun 2019; 521:57-63. [PMID: 31635807 DOI: 10.1016/j.bbrc.2019.10.071] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 10/08/2019] [Indexed: 12/28/2022]
Abstract
Aberrant Ca2+ release from cardiac ryanodine receptors (RyR2) has been shown to be one of the most important causes of lethal arrhythmia in various types of failing hearts. We previously showed that dantrolene, a specific agent for the treatment of malignant hyperthermia, inhibits Ca2+ leakage from the RyR2 by correcting the defective inter-domain interaction between the N-terminal (1-619 amino acids) and central (2000-2500 amino acids) domains of the RyR2 and allosterically enhancing the binding affinity of calmodulin to the RyR2 in diseased hearts. In this study, we examined whether dantrolene inhibits this Ca2+ leakage, thereby preventing the pharmacologically inducible ventricular tachycardia in ventricular pressure-overloaded failing hearts. Ventricular tachycardia (VT) was easily induced after an injection of epinephrine in mice after 8 weeks of transverse aortic constriction-induced pressure-overload. Pretreatment with dantrolene almost completely inhibited the pharmacologically inducible VT. In the presence of dantrolene, the occurrence of both Ca2+ sparks and spontaneous Ca2+ transients was inhibited, which was associated with enhanced calmodulin binding affinity to the RyR2. These results suggest that dantrolene could be a new potent agent in the treatment of lethal arrhythmia in cases of acquired heart failure.
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Affiliation(s)
- Toshiro Kajii
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Shigeki Kobayashi
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Sho Shiba
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Shohei Fujii
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Masaki Tamitani
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Michiaki Kohno
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Yoshihide Nakamura
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Takuma Nanno
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Takayoshi Kato
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Shinichi Okuda
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Hitoshi Uchinoumi
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Tetsuro Oda
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Takeshi Yamamoto
- Faculty of Health Sciences, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Masafumi Yano
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi, 755-8505, Japan.
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13
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Nakamura Y, Yamamoto T, Kobayashi S, Tamitani M, Hamada Y, Fukui G, Xu X, Nishimura S, Kato T, Uchinoumi H, Oda T, Okuda S, Yano M. Ryanodine receptor-bound calmodulin is essential to protect against catecholaminergic polymorphic ventricular tachycardia. JCI Insight 2019; 4:126112. [PMID: 31167968 DOI: 10.1172/jci.insight.126112] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 04/17/2019] [Indexed: 12/12/2022] Open
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is caused by a single point mutation in the cardiac type 2 ryanodine receptor (RyR2). Using a knockin (KI) mouse model (R2474S/+), we previously reported that a single point mutation within the RyR2 sensitizes the channel to agonists, primarily mediated by defective interdomain interaction within the RyR2 and subsequent dissociation of calmodulin (CaM) from the RyR2. Here, we examined whether CPVT can be genetically rescued by enhancing the binding affinity of CaM to the RyR2. We first determined whether there is a possible amino acid substitution within the CaM-binding domain in the RyR2 (3584-3603 residues) that can enhance its binding affinity to CaM and found that V3599K substitution showed the highest binding affinity of CaM to the CaM-binding domain. Hence, we generated a heterozygous KI mouse model (V3599K/+) with a single amino acid substitution in the CaM-binding domain of the RyR2 and crossbred it with the heterozygous CPVT-associated R2474S/+-KI mouse to obtain a double-heterozygous R2474S/V3599K-KI mouse model. The CPVT phenotypes - bidirectional or polymorphic ventricular tachycardia, spontaneous Ca2+ transients, and Ca2+ sparks - were all inhibited in the R2474S/V3599K mice. Thus, enhancement of the CaM-binding affinity of the RyR2 is essential to prevent CPVT-associated arrhythmogenesis.
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Affiliation(s)
- Yoshihide Nakamura
- Department of Medicine and Clinical Science, Division of Cardiology, and
| | - Takeshi Yamamoto
- Faculty of Health Sciences, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan
| | - Shigeki Kobayashi
- Department of Medicine and Clinical Science, Division of Cardiology, and
| | - Masaki Tamitani
- Department of Medicine and Clinical Science, Division of Cardiology, and
| | - Yoriomi Hamada
- Department of Medicine and Clinical Science, Division of Cardiology, and
| | - Go Fukui
- Department of Medicine and Clinical Science, Division of Cardiology, and
| | - Xiaojuan Xu
- Department of Pathology and Pathophysiology, School of Medicine, Tongji University, Shanghai, China
| | | | - Takayoshi Kato
- Department of Medicine and Clinical Science, Division of Cardiology, and
| | - Hitoshi Uchinoumi
- Department of Medicine and Clinical Science, Division of Cardiology, and
| | - Tetsuro Oda
- Department of Medicine and Clinical Science, Division of Cardiology, and
| | - Shinichi Okuda
- Department of Medicine and Clinical Science, Division of Cardiology, and
| | - Masafumi Yano
- Department of Medicine and Clinical Science, Division of Cardiology, and
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14
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Kushnir A, Wajsberg B, Marks AR. Ryanodine receptor dysfunction in human disorders. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:1687-1697. [PMID: 30040966 DOI: 10.1016/j.bbamcr.2018.07.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 07/13/2018] [Accepted: 07/14/2018] [Indexed: 01/07/2023]
Abstract
Regulation of intracellular calcium (Ca2+) is critical in all cell types. The ryanodine receptor (RyR), an intracellular Ca2+ release channel located on the sarco/endoplasmic reticulum (SR/ER), releases Ca2+ from intracellular stores to activate critical functions including muscle contraction and neurotransmitter release. Dysfunctional RyR-mediated Ca2+ handling has been implicated in the pathogenesis of inherited and non-inherited conditions including heart failure, cardiac arrhythmias, skeletal myopathies, diabetes, and neurodegenerative diseases. Here we have reviewed the evidence linking human disorders to RyR dysfunction and describe novel approaches to RyR-targeted therapeutics.
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Affiliation(s)
- Alexander Kushnir
- Department of Physiology and Cellular Biophysics, Clyde and Helen Wu Center for Molecular Cardiology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY 10032, USA; Department of Medicine, Division of Cardiology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY 10032, USA
| | - Benjamin Wajsberg
- Department of Physiology and Cellular Biophysics, Clyde and Helen Wu Center for Molecular Cardiology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY 10032, USA
| | - Andrew R Marks
- Department of Physiology and Cellular Biophysics, Clyde and Helen Wu Center for Molecular Cardiology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY 10032, USA.
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15
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Nishimura S, Yamamoto T, Nakamura Y, Kohno M, Hamada Y, Sufu Y, Fukui G, Nanno T, Ishiguchi H, Kato T, Xu X, Ono M, Oda T, Okuda S, Kobayashi S, Yano M. Mutation-linked, excessively tight interaction between the calmodulin binding domain and the C-terminal domain of the cardiac ryanodine receptor as a novel cause of catecholaminergic polymorphic ventricular tachycardia. Heart Rhythm 2018; 15:905-914. [PMID: 29427818 DOI: 10.1016/j.hrthm.2018.02.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Indexed: 12/16/2022]
Abstract
BACKGROUND Ryanodine receptor (RyR2) is known to be a causal gene of catecholaminergic polymorphic ventricular tachycardia (CPVT), an important inherited disease. Some of the human CPVT-associated mutations have been found in a domain (4026-4172) that has EF hand motifs, the so-called calmodulin (CaM)-like domain (CaMLD). OBJECTIVE The purpose of this study was to investigate the underlying mechanism by which CPVT is induced by a mutation at CaMLD. METHODS A new N4103K/+ knock-in (KI) mice model was generated. RESULTS Sustained ventricular tachycardia was frequently observed after infusion of caffeine plus epinephrine in KI mice. Endogenous CaM bound to RyR2 decreased even at baseline in isolated KI cardiomyocytes. Ca2+ spark frequency (CaSpF) was much higher in KI cells than in wild-type cells. Addition of GSH-CaM (higher affinity CaM to RyR2) significantly decreased CaSpF. In response to isoproterenol, spontaneous Ca2+ transient (SCaT) was frequently observed in intact KI cells. Incorporation of GSH-CaM into intact KI cells using a protein delivery kit decreased SCaT significantly. An assay using a quartz crystal microbalance technique revealed that mutated CaMLD peptide showed higher binding affinity to CaM binding domain (CaMBD) peptide. CONCLUSION In the N4103K mutant, CaM binding affinity to RyR2 was significantly reduced regardless of beta-adrenergic stimulation. We found that this was caused by an abnormally tight interaction between CaMBD and mutated CaM-like domain (N4103K-CaMBD). Thus, CaMBD-CaMLD interaction may be a novel therapeutic target for treatment of lethal arrhythmia.
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Affiliation(s)
- Shigehiko Nishimura
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Takeshi Yamamoto
- Faculty of Health Sciences, Yamaguchi University Graduate School of Medicine, Ube, Japan.
| | - Yoshihide Nakamura
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Michiaki Kohno
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Yoriomi Hamada
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Yoko Sufu
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Go Fukui
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Takuma Nanno
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Hironori Ishiguchi
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Takayoshi Kato
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Xiaojuan Xu
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Makoto Ono
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Tetsuro Oda
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Shinichi Okuda
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Shigeki Kobayashi
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Masafumi Yano
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, Ube, Japan
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16
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17
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Kato T, Yamamoto T, Nakamura Y, Nanno T, Fukui G, Sufu Y, Hamada Y, Maeda T, Nishimura S, Ishiguchi H, Murakami W, Fukuda M, Xu X, Hino A, Ono M, Oda T, Okuda S, Kobayashi S, Koseki N, Kyushiki H, Yano M. Correction of impaired calmodulin binding to RyR2 as a novel therapy for lethal arrhythmia in the pressure-overloaded heart failure. Heart Rhythm 2017; 14:120-127. [DOI: 10.1016/j.hrthm.2016.10.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Indexed: 11/29/2022]
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18
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Abstract
Cardiac arrhythmias can follow disruption of the normal cellular electrophysiological processes underlying excitable activity and their tissue propagation as coherent wavefronts from the primary sinoatrial node pacemaker, through the atria, conducting structures and ventricular myocardium. These physiological events are driven by interacting, voltage-dependent, processes of activation, inactivation, and recovery in the ion channels present in cardiomyocyte membranes. Generation and conduction of these events are further modulated by intracellular Ca2+ homeostasis, and metabolic and structural change. This review describes experimental studies on murine models for known clinical arrhythmic conditions in which these mechanisms were modified by genetic, physiological, or pharmacological manipulation. These exemplars yielded molecular, physiological, and structural phenotypes often directly translatable to their corresponding clinical conditions, which could be investigated at the molecular, cellular, tissue, organ, and whole animal levels. Arrhythmogenesis could be explored during normal pacing activity, regular stimulation, following imposed extra-stimuli, or during progressively incremented steady pacing frequencies. Arrhythmic substrate was identified with temporal and spatial functional heterogeneities predisposing to reentrant excitation phenomena. These could arise from abnormalities in cardiac pacing function, tissue electrical connectivity, and cellular excitation and recovery. Triggering events during or following recovery from action potential excitation could thereby lead to sustained arrhythmia. These surface membrane processes were modified by alterations in cellular Ca2+ homeostasis and energetics, as well as cellular and tissue structural change. Study of murine systems thus offers major insights into both our understanding of normal cardiac activity and its propagation, and their relationship to mechanisms generating clinical arrhythmias.
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Affiliation(s)
- Christopher L-H Huang
- Physiological Laboratory and the Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
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19
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Murakami W, Kobayashi S, Susa T, Nanno T, Ishiguchi H, Myoren T, Nishimura S, Kato T, Hino A, Oda T, Okuda S, Yamamoto T, Yano M. Recombinant Atrial Natriuretic Peptide Prevents Aberrant Ca2+ Leakage through the Ryanodine Receptor by Suppressing Mitochondrial Reactive Oxygen Species Production Induced by Isoproterenol in Failing Cardiomyocytes. PLoS One 2016; 11:e0163250. [PMID: 27657534 PMCID: PMC5033569 DOI: 10.1371/journal.pone.0163250] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 09/05/2016] [Indexed: 12/27/2022] Open
Abstract
Catecholamines induce intracellular reactive oxygen species (ROS), thus enhancing diastolic Ca2+ leakage through the ryanodine receptor during heart failure (HF). However, little is known regarding the effect of atrial natriuretic peptide (ANP) on ROS generation and Ca2+ handling in failing cardiomyocytes. The aim of the present study was to clarify the mechanism by which an exogenous ANP exerts cardioprotective effects during HF. Cardiomyocytes were isolated from the left ventricles of a canine tachycardia-induced HF model and sham-operated vehicle controls. The degree of mitochondrial oxidized DNA was evaluated by double immunohistochemical (IHC) staining using an anti-VDAC antibody for the mitochondria and an anti-8-hydroxy-2′-deoxyguanosine antibody for oxidized DNA. The effect of ANP on ROS was investigated using 2,7-dichlorofluorescin diacetate, diastolic Ca2+ sparks assessed by confocal microscopy using Fluo 4-AM, and the survival rate of myocytes after 48 h. The double IHC study revealed that isoproterenol (ISO) markedly increased oxidized DNA in the mitochondria in HF and that the ISO-induced DNA damage was markedly inhibited by the co-presence of ANP. ROS production and Ca2+ spark frequency (CaSF) were increased in HF compared to normal controls, and were further increased in the presence of ISO. Notably, ANP significantly suppressed both ISO-induced ROS and CaSF without changing sarcoplasmic reticulum Ca2+ content in HF (p<0.01, respectively). The survival rate after 48 h in HF was significantly decreased in the presence of ISO compared with baseline (p<0.01), whereas it was significantly improved by the co-presence of ANP (p<0.01). Together, our results suggest that ANP strongly suppresses ISO-induced mitochondrial ROS generation, which might correct aberrant diastolic Ca2+ sparks, eventually contributing to the improvement of cardiomyocyte survival in HF.
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Affiliation(s)
- Wakako Murakami
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755–8505, Japan
| | - Shigeki Kobayashi
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755–8505, Japan
- * E-mail:
| | - Takehisa Susa
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755–8505, Japan
| | - Takuma Nanno
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755–8505, Japan
| | - Hironori Ishiguchi
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755–8505, Japan
| | - Takeki Myoren
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755–8505, Japan
| | - Shigehiko Nishimura
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755–8505, Japan
| | - Takayoshi Kato
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755–8505, Japan
| | - Akihiro Hino
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755–8505, Japan
| | - Tetsuro Oda
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755–8505, Japan
| | - Shinichi Okuda
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755–8505, Japan
| | - Takeshi Yamamoto
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755–8505, Japan
| | - Masafumi Yano
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755–8505, Japan
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20
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Abstract
The ryanodine receptor/Ca2+ release channel plays a pivotal role in skeletal and cardiac muscle excitation-contraction coupling. Defective regulation leads to neuromuscular disorders and arrhythmogenic cardiac disease. This mini-review focuses on channel regulation through structural intra- and inter-subunit interactions and their implications in ryanodine receptor pathophysiology.
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21
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Roe AT, Frisk M, Louch WE. Targeting cardiomyocyte Ca2+ homeostasis in heart failure. Curr Pharm Des 2015; 21:431-48. [PMID: 25483944 PMCID: PMC4475738 DOI: 10.2174/138161282104141204124129] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Accepted: 08/06/2014] [Indexed: 12/19/2022]
Abstract
Improved treatments for heart failure patients will require the development of novel therapeutic strategies that target basal disease
mechanisms. Disrupted cardiomyocyte Ca2+ homeostasis is recognized as a major contributor to the heart failure phenotype, as it
plays a key role in systolic and diastolic dysfunction, arrhythmogenesis, and hypertrophy and apoptosis signaling. In this review, we outline
existing knowledge of the involvement of Ca2+ homeostasis in these deficits, and identify four promising targets for therapeutic intervention:
the sarcoplasmic reticulum Ca2+ ATPase, the Na+-Ca2+ exchanger, the ryanodine receptor, and t-tubule structure. We discuss
experimental data indicating the applicability of these targets that has led to recent and ongoing clinical trials, and suggest future therapeutic
approaches.
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Affiliation(s)
| | | | - William E Louch
- Institute for Experimental Medical Research, Kirkeveien 166, 4.etg. Bygg 7, Oslo University Hospital Ullevål, 0407 Oslo, Norway.
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FRET-based trilateration of probes bound within functional ryanodine receptors. Biophys J 2015; 107:2037-48. [PMID: 25418089 DOI: 10.1016/j.bpj.2014.09.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 09/08/2014] [Accepted: 09/19/2014] [Indexed: 02/05/2023] Open
Abstract
To locate the biosensor peptide DPc10 bound to ryanodine receptor (RyR) Ca(2+) channels, we developed an approach that combines fluorescence resonance energy transfer (FRET), simulated-annealing, cryo-electron microscopy, and crystallographic data. DPc10 is identical to the 2460-2495 segment within the cardiac muscle RyR isoform (RyR2) central domain. DPc10 binding to RyR2 results in a pathologically elevated Ca(2+) leak by destabilizing key interactions between the RyR2 N-terminal and central domains (unzipping). To localize the DPc10 binding site within RyR2, we measured FRET between five single-cysteine variants of the FK506-binding protein (FKBP) labeled with a donor probe, and DPc10 labeled with an acceptor probe (A-DPc10). Effective donor positions were calculated from simulated-annealing constrained by both the RyR cryo-EM map and the FKBP atomic structure docked to the RyR. FRET to A-DPc10 was measured in permeabilized cardiomyocytes via confocal microscopy, converted to distances, and used to trilaterate the acceptor locus within RyR. Additional FRET measurements between donor-labeled calmodulin and A-DPc10 were used to constrain the trilaterations. Results locate the DPc10 probe within RyR domain 3, ?35 Å from the previously docked N-terminal domain crystal structure. This multiscale approach may be useful in mapping other RyR sites of mechanistic interest within FRET range of FKBP.
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Kobayashi S, Susa T, Ishiguchi H, Myoren T, Murakami W, Kato T, Fukuda M, Hino A, Suetomi T, Ono M, Uchinoumi H, Tateishi H, Mochizuki M, Oda T, Okuda S, Doi M, Yamamoto T, Yano M. A low-dose β1-blocker in combination with milrinone improves intracellular Ca2+ handling in failing cardiomyocytes by inhibition of milrinone-induced diastolic Ca2+ leakage from the sarcoplasmic reticulum. PLoS One 2015; 10:e0114314. [PMID: 25614983 PMCID: PMC4304815 DOI: 10.1371/journal.pone.0114314] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 11/05/2014] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVES The purpose of this study was to investigate whether adding a low-dose β1-blocker to milrinone improves cardiac function in failing cardiomyocytes and the underlying cardioprotective mechanism. BACKGROUND The molecular mechanism underlying how the combination of low-dose β1-blocker and milrinone affects intracellular Ca(2+) handling in heart failure remains unclear. METHODS We investigated the effect of milrinone plus landiolol on intracellular Ca(2+) transient (CaT), cell shortening (CS), the frequency of diastolic Ca(2+) sparks (CaSF), and sarcoplasmic reticulum Ca(2+) concentration ({Ca(2+)}SR) in normal and failing canine cardiomyocytes and used immunoblotting to determine the phosphorylation level of ryanodine receptor (RyR2) and phospholamban (PLB). RESULTS In failing cardiomyocytes, CaSF significantly increased, and peak CaT and CS markedly decreased compared with normal myocytes. Administration of milrinone alone slightly increased peak CaT and CS, while CaSF greatly increased with a slight increase in {Ca(2+)}SR. Co-administration of β1-blocker landiolol to failing cardiomyocytes at a dose that does not inhibit cardiomyocyte function significantly decreased CaSF with a further increase in {Ca(2+)}SR, and peak CaT and CS improved compared with milrinone alone. Landiolol suppressed the hyperphosphorylation of RyR2 (Ser2808) in failing cardiomyocytes but had no effect on levels of phosphorylated PLB (Ser16 and Thr17). Low-dose landiolol significantly inhibited the alternans of CaT and CS under a fixed pacing rate (0.5 Hz) in failing cardiomyocytes. CONCLUSION A low-dose β1-blocker in combination with milrinone improved cardiac function in failing cardiomyocytes, apparently by inhibiting the phosphorylation of RyR2, not PLB, and subsequent diastolic Ca(2+) leak.
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Affiliation(s)
- Shigeki Kobayashi
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Japan
- * E-mail:
| | - Takehisa Susa
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Hironori Ishiguchi
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Takeki Myoren
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Wakako Murakami
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Takayoshi Kato
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Masakazu Fukuda
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Akihiro Hino
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Takeshi Suetomi
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Makoto Ono
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Hitoshi Uchinoumi
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Hiroki Tateishi
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Mamoru Mochizuki
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Tetsuro Oda
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Shinichi Okuda
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Masahiro Doi
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Takeshi Yamamoto
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Masafumi Yano
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Japan
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Fukuda M, Yamamoto T, Nishimura S, Kato T, Murakami W, Hino A, Ono M, Tateishi H, Oda T, Okuda S, Kobayashi S, Koseki N, Kyushiki H, Yano M. Enhanced binding of calmodulin to RyR2 corrects arrhythmogenic channel disorder in CPVT-associated myocytes. Biochem Biophys Res Commun 2014; 448:1-7. [DOI: 10.1016/j.bbrc.2014.03.152] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 03/31/2014] [Indexed: 11/29/2022]
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Yano M, Okuda S. Does a ripple of Ca(2+) leak develop into a rogue wave that can trigger pathological hypertrophy? J Am Coll Cardiol 2013; 63:1580-2. [PMID: 24315910 DOI: 10.1016/j.jacc.2013.10.064] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 10/25/2013] [Accepted: 10/28/2013] [Indexed: 11/26/2022]
Affiliation(s)
- Masafumi Yano
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, Minamikogushi, Ube, Yamaguchi, Japan.
| | - Shinichi Okuda
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, Minamikogushi, Ube, Yamaguchi, Japan
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Abstract
AbstractThe effect of a domain peptide DPCPVTc from the central region of the RYR2 on ryanodine receptors from rat heart has been examined in planar lipid bilayers. At a zero holding potential and at 8 mmol L−1 luminal Ca2+ concentration, DPCPVTc induced concentrationdependent activation of the ryanodine receptor that led up to 20-fold increase of PO at saturating DPCPVTc concentrations. DPCPVTc prolonged RyR2 openings and increased RyR2 opening frequency. At all peptide concentrations the channels displayed large variability in open probability, open time and frequency of openings. With increasing peptide concentration, the fraction of high open probability records increased together with their open time. The closed times of neither low- nor high-open probability records depended on peptide concentration. The concentration dependence of all gating parameters had EC50 of 20 μmol L−1 and a Hill slope of 2. Comparison of the effects of DPCPVTc with the effects of ATP and cytosolic Ca2+ suggests that activation does not involve luminal feed-through and is not caused by modulation of the cytosolic activation A-site. The data suggest that although “domain unzipping” by DPCPVTc occurs in both modes of RyR activity, it affects RyR gating only when the channel resides in the H-mode of activity.
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Yano M, Yamamoto T, Kobayashi S, Matsuzaki M. [Molecular mechanism of defective intracellular calcium release in heart failure and lethal arrhythmia]. Nihon Yakurigaku Zasshi 2012; 140:250-4. [PMID: 23229629 DOI: 10.1254/fpj.140.250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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28
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Hino A, Yano M, Kato T, Fukuda M, Suetomi T, Ono M, Murakami W, Susa T, Okuda S, Doi M, Kobayashi S, Yamamoto T, Koseki N, Kyushiki H, Ikemoto N, Matsuzaki M. Enhanced binding of calmodulin to the ryanodine receptor corrects contractile dysfunction in failing hearts. Cardiovasc Res 2012; 96:433-43. [PMID: 22893680 DOI: 10.1093/cvr/cvs271] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
AIMS The channel function of the cardiac ryanodine receptor (RyR2) is modulated by calmodulin (CaM). However, the involvement of CaM in aberrant Ca(2+) release in diseased hearts remains unclear. Here, we investigated the pathogenic role of defective CaM binding to the RyR2 in the channel dysfunction associated with heart failure. METHODS AND RESULTS The involvement of CaM in aberrant Ca(2+) release was assessed in normal and pacing-induced failing canine hearts. The apparent affinity of CaM for RyR2 was considerably lower in failing sarcoplasmic reticulum (SR) compared with normal SR. Thus, the amount of CaM bound to RyR2 was markedly decreased in failing myocytes. Expression of the CaM isoform Gly-Ser-His-CaM (GSH-CaM), which has much higher binding affinity than wild-type CaM for RyR1, restored normal CaM binding to RyR2 in both SR and myocytes of failing hearts. The Ca(2+) spark frequency (SpF) was markedly higher and the SR Ca(2+) content was lower in failing myocytes compared with normal myocytes. The incorporation of GSH-CaM into the failing myocytes corrected the aberrant SpF and SR Ca(2+) content to normal levels. CONCLUSION Reduced CaM binding to RyR2 seems to play a critical role in the pathogenesis of aberrant Ca(2+) release in failing hearts. Correction of the reduced CaM binding to RyR2 stabilizes the RyR2 channel function and thereby restores normal Ca(2+) handling and contractile function to failing hearts.
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Affiliation(s)
- Akihiro Hino
- Division of Cardiology, Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan
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Venetucci L, Denegri M, Napolitano C, Priori SG. Inherited calcium channelopathies in the pathophysiology of arrhythmias. Nat Rev Cardiol 2012; 9:561-75. [DOI: 10.1038/nrcardio.2012.93] [Citation(s) in RCA: 141] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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30
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Thomas NL, Williams AJ. Pharmacology of ryanodine receptors and Ca2+-induced Ca2+ release. ACTA ACUST UNITED AC 2012. [DOI: 10.1002/wmts.34] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Aberrant interaction of calmodulin with the ryanodine receptor develops hypertrophy in the neonatal cardiomyocyte. Biochem J 2011; 438:379-87. [PMID: 21649588 DOI: 10.1042/bj20110203] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We have shown previously that the inter-domain interaction between the two domains of RyR (ryanodine receptor), CaMBD [CaM (calmodulin)-binding domain] and CaMLD (CaM-like domain), activates the Ca(2+) channel, and this process is called activation-link formation [Gangopadhyay and Ikemoto (2008) Biochem. J. 411, 415-423]. Thus CaM that is bound to CaMBD is expected to interfere the activation-link formation, thereby stabilizing the closed state of the channel under normal conditions. In the present paper, we report that, upon stimulation of neonatal cardiomyocytes with the pro-hypertrophy agonist ET-1 (endothelin-1), CaM dissociates from the RyR, which induces a series of intracellular events: increased frequency of Ca(2+) transients, translocation of the signalling molecules CaM, CaMKII (CaM kinase II) and the transcription factor NFAT (nuclear factor of activated T-cells) to the nucleus. These events then lead to the development of hypertrophy. Importantly, an anti-CaMBD antibody that interferes with activation-link formation prevented all of these intracellular events triggered by ET-1 and prevented the development of hypertrophy. These results indicate that the aberrant formation of the activation link between CaMBD and CaMLD of RyR is a key step in the development of hypertrophy in cultured cardiomyocytes.
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Turan B, Vassort G. Ryanodine receptor: a new therapeutic target to control diabetic cardiomyopathy. Antioxid Redox Signal 2011; 15:1847-61. [PMID: 21091075 DOI: 10.1089/ars.2010.3725] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Diabetes mellitus is a major risk factor for cardiovascular complications. Intracellular Ca(2+) release plays an important role in the regulation of muscle contraction. Sarcoplasmic reticulum Ca(2+) release is controlled by dedicated molecular machinery, composed of a complex of cardiac ryanodine receptors (RyR2s). Acquired and genetic defects in this complex result in a spectrum of abnormal Ca(2+) release phenotypes in heart. Cardiovascular dysfunction is a leading cause for mortality of diabetic individuals due, in part, to a specific cardiomyopathy, and to altered vascular reactivity. Cardiovascular complications result from multiple parameters, including glucotoxicity, lipotoxicity, fibrosis, and mitochondrial uncoupling. In diabetic subjects, oxidative stress arises from an imbalance between production of reactive oxygen and nitrogen species and capability of the system to readily detoxify reactive intermediates. To date, the etiology underlying diabetes-induced reductions in myocyte and cardiac contractility remains incompletely understood. However, numerous studies, including work from our laboratory, suggest that these defects stem in part from perturbation in intracellular Ca(2+) cycling. Since the RyR2s are one of the well-characterized redox-sensitive ion channels in heart, this article summarizes recent findings on redox regulation of cardiac Ca(2+) transport systems and discusses contributions of redox regulation to pathological cardiac function in diabetes.
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Affiliation(s)
- Belma Turan
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey .
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33
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Two candidates at the heart of dysfunction: The ryanodine receptor and calcium/calmodulin protein kinase II as potential targets for therapeutic intervention—An in vivo perspective. Pharmacol Ther 2011; 131:204-20. [DOI: 10.1016/j.pharmthera.2011.02.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Accepted: 02/17/2011] [Indexed: 11/19/2022]
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34
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Suetomi T, Yano M, Uchinoumi H, Fukuda M, Hino A, Ono M, Xu X, Tateishi H, Okuda S, Doi M, Kobayashi S, Ikeda Y, Yamamoto T, Ikemoto N, Matsuzaki M. Mutation-linked defective interdomain interactions within ryanodine receptor cause aberrant Ca²⁺release leading to catecholaminergic polymorphic ventricular tachycardia. Circulation 2011; 124:682-94. [PMID: 21768539 DOI: 10.1161/circulationaha.111.023259] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The molecular mechanism by which catecholaminergic polymorphic ventricular tachycardia is induced by single amino acid mutations within the cardiac ryanodine receptor (RyR2) remains elusive. In the present study, we investigated mutation-induced conformational defects of RyR2 using a knockin mouse model expressing the human catecholaminergic polymorphic ventricular tachycardia-associated RyR2 mutant (S2246L; serine to leucine mutation at the residue 2246). METHODS AND RESULTS All knockin mice we examined produced ventricular tachycardia after exercise on a treadmill. cAMP-dependent increase in the frequency of Ca²⁺ sparks was more pronounced in saponin-permeabilized knockin cardiomyocytes than in wild-type cardiomyocytes. Site-directed fluorescent labeling and quartz microbalance assays of the specific binding of DP2246 (a peptide corresponding to the 2232 to 2266 region: the 2246 domain) showed that DP2246 binds with the K201-binding sequence of RyR2 (1741 to 2270). Introduction of S2246L mutation into the DP2246 increased the affinity of peptide binding. Fluorescence quench assays of interdomain interactions within RyR2 showed that tight interaction of the 2246 domain/K201-binding domain is coupled with domain unzipping of the N-terminal (1 to 600)/central (2000 to 2500) domain pair in an allosteric manner. Dantrolene corrected the mutation-caused domain unzipping of the domain switch and stopped the exercise-induced ventricular tachycardia. CONCLUSIONS The catecholaminergic polymorphic ventricular tachycardia-linked mutation of RyR2, S2246L, causes an abnormally tight local subdomain-subdomain interaction within the central domain involving the mutation site, which induces defective interaction between the N-terminal and central domains. This results in an erroneous activation of Ca²⁺ channel in a diastolic state reflecting on the increased Ca²⁺ spark frequency, which then leads to lethal arrhythmia.
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Affiliation(s)
- Takeshi Suetomi
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, Yamaguchi, 755-8505, Japan
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35
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Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmogenic disease occurring in patients with a structurally normal heart: the disease is characterized by life-threatening arrhythmias elicited by stress and emotion. In 2001, the ryanodine receptor was identified as the gene that is linked to CPVT; shortly thereafter, cardiac calsequestrin was implicated in the recessive form of the same disease. It became clear that abnormalities in intracellular Ca(2+) regulation could profoundly disrupt the electrophysiological properties of the heart. In this article, we discuss the molecular basis of the disease and the pathophysiological mechanisms that are impacting clinical diagnosis and management of affected individuals. As of today, the interaction between basic scientists and clinicians to understand CPVT and identify new therapeutic strategies is one of the most compelling examples of the importance of translational research in cardiology.
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Affiliation(s)
- Silvia G Priori
- Molecular Cardiology Laboratories, IRCCS Fondazione Salvatore Maugeri, Via Maugeri 10/10A, Pavia, Italy.
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36
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Becker B, Cooper MA. A survey of the 2006-2009 quartz crystal microbalance biosensor literature. J Mol Recognit 2011; 24:754-87. [DOI: 10.1002/jmr.1117] [Citation(s) in RCA: 138] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Abstract
Antiarrhythmic drugs are a group of pharmaceuticals that suppress or prevent abnormal heart rhythms, which are often associated with substantial morbidity and mortality. Current antiarrhythmic drugs that typically target plasma membrane ion channels have limited clinical success and in some cases have been described as being pro-arrhythmic. However, recent studies suggest that pathological release of calcium (Ca(2+)) from the sarcoplasmic reticulum via cardiac ryanodine receptors (RyR2) could represent a promising target for antiarrhythmic therapy. Diastolic SR Ca(2+) release has been linked to arrhythmogenesis in both the inherited arrhythmia syndrome 'catecholaminergic polymorphic ventricular tachycardia' and acquired forms of heart disease (eg, atrial fibrillation, heart failure). Several classes of pharmaceuticals have been shown to reduce abnormal RyR2 activity and may confer protection against triggered arrhythmias through reduction of SR Ca(2+) leak. In this review, we will evaluate the current pharmacological methods for stabilizing RyR2 and suggest treatment modalities based on current evidence of molecular mechanisms.
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38
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Kushnir A, Marks AR. The ryanodine receptor in cardiac physiology and disease. ADVANCES IN PHARMACOLOGY 2010; 59:1-30. [PMID: 20933197 DOI: 10.1016/s1054-3589(10)59001-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
According to the American Heart Association it is estimated that the United States will spend close to $39 billion in 2010 to treat over five million Americans suffering from heart failure. Patients with heart failure suffer from dyspnea and decreased exercised tolerance and are at increased risk for fatal ventricular arrhythmias. Food and Drug Administration -approved pharmacologic therapies for heart failure include diuretics, inhibitors of the renin-angiotensin system, and β-adrenergic receptor antagonists. Over the past 20 years advances in the field of ryanodine receptor (RyR2)/calcium release channel research have greatly advanced our understanding of cardiac physiology and the pathogenesis of heart failure and arrhythmias. Here we review the key observations, controversies, and discoveries that have led to the development of novel compounds targeting the RyR2/calcium release channel for treating heart failure and for preventing lethal arrhythmias.
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Affiliation(s)
- Alexander Kushnir
- Department of Physiology and Cellular Biophysics, Clyde and Helen Wu Center for Molecular Cardiology, College of Physicians and Surgeons of Columbia University, New York, NY, USA
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Kobayashi S, Yano M, Uchinoumi H, Suetomi T, Susa T, Ono M, Xu X, Tateishi H, Oda T, Okuda S, Doi M, Yamamoto T, Matsuzaki M. Dantrolene, a therapeutic agent for malignant hyperthermia, inhibits catecholaminergic polymorphic ventricular tachycardia in a RyR2(R2474S/+) knock-in mouse model. Circ J 2010; 74:2579-84. [PMID: 20944434 DOI: 10.1253/circj.cj-10-0680] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Dantrolene, a specific agent for the treatment of malignant hyperthermia, was found to inhibit Ca(2+) leak through not only the skeletal ryanodine receptor (RyR1), but also the cardiac ryanodine receptor (RyR2) by correcting the defective inter-domain interaction between N-terminal (1-619 amino acid) and central (2,000-2,500 amino acid) domains of RyRs. Here, the in vivo anti-arrhythmic effect of dantrolene in a human catecholaminergic polymorphic ventricular tachycardia (CPVT)-associated RyR2(R2474S/+) knock-in (KI) mouse model was investigated. METHODS AND RESULTS ECG was monitored in KI mice (n=6) and wild-type (WT) mice (n=6), before and after an injection of epinephrine (1.0mg/kg) or on exercise using a treadmill. In all KI (but not WT) mice, bi-directional ventricular tachycardia (VT) was induced after an injection of epinephrine or on exercise. Pre-treatment with dantrolene (for 7-10 days) significantly inhibited the inducible VT (P<0.01). In KI cardiomyocytes, Ca(2+) spark frequency (SpF; s(-1)·100µm(-1): 5.8±0.3, P<0.01) was much more increased after the addition of isoproterenol than in WT cardiomyocytes (SpF: 3.6±0.2). The increase in SpF seen in KI cardiomyocytes was attenuated by 1.0µmol/L dantrolene (SpF: 3.6±0.5, P<0.01). CONCLUSIONS Dantrolene prevents CPVT, presumably by inhibiting Ca(2+) leak through the RyR2.
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Affiliation(s)
- Shigeki Kobayashi
- Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Japan
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40
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Wagenknecht TC, Liu Z. Electron microscopy of ryanodine receptors. CURRENT TOPICS IN MEMBRANES 2010; 66:27-47. [PMID: 22353475 DOI: 10.1016/s1063-5823(10)66002-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Terence C Wagenknecht
- Wadsworth Center, New York State Department of Health, Albany, New York, USA; Department of Biomedical Sciences, School of Public Health, State University of New York at Albany, Albany, New York, USA
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41
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Betzenhauser MJ, Marks AR. Ryanodine receptor channelopathies. Pflugers Arch 2010; 460:467-80. [PMID: 20179962 PMCID: PMC2885589 DOI: 10.1007/s00424-010-0794-4] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Revised: 01/26/2010] [Accepted: 01/28/2010] [Indexed: 02/07/2023]
Abstract
Ryanodine receptors (RyR) are intracellular Ca2+-permeable channels that provide the sarcoplasmic reticulum Ca2+ release required for skeletal and cardiac muscle contractions. RyR1 underlies skeletal muscle contraction, and RyR2 fulfills this role in cardiac muscle. Over the past 20 years, numerous mutations in both RyR isoforms have been identified and linked to skeletal and cardiac diseases. Malignant hyperthermia, central core disease, and catecholaminergic polymorphic ventricular tachycardia have been genetically linked to mutations in either RyR1 or RyR2. Thus, RyR channelopathies are both of interest because they cause significant human diseases and provide model systems that can be studied to elucidate important structure-function relationships of these ion channels.
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Affiliation(s)
- Matthew J Betzenhauser
- Department of Physiology, Clyde and Helen Wu Center for Molecular Cardiology, Columbia University College of Physicians and Surgeons, 630 West 168th Street, New York, NY 10032, USA
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Gangopadhyay JP, Ikemoto N. Intracellular translocation of calmodulin and Ca2+/calmodulin-dependent protein kinase II during the development of hypertrophy in neonatal cardiomyocytes. Biochem Biophys Res Commun 2010; 396:515-21. [PMID: 20433809 PMCID: PMC2878933 DOI: 10.1016/j.bbrc.2010.04.129] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Accepted: 04/23/2010] [Indexed: 10/19/2022]
Abstract
We have recently shown that stimulation of cultured neonatal cardiomyocytes with endothelin-1 (ET-1) first produces conformational disorder within the ryanodine receptor (RyR2) and diastolic Ca(2+) leak from the sarcoplasmic reticulum (SR), then develops hypertrophy (HT) in the cardiomyocytes (Hamada et al., 2009 [3]). The present paper addresses the following question. By what mechanism does crosstalk between defective operation of RyR2 and activation of the HT gene program occur? Here we show that the immuno-stain of calmodulin (CaM) is localized chiefly in the cytoplasmic area in the control cells; whereas, in the ET-1-treated/hypertrophied cells, major immuno-staining is localized in the nuclear region. In addition, fluorescently labeled CaM that has been introduced into the cardiomyocytes using the BioPORTER system moves from the cytoplasm to the nucleus with the development of HT. The immuno-confocal imaging of Ca(2+)/CaM-dependent protein kinase II (CaMKII) also shows cytoplasm-to-nucleus shift of the immuno-staining pattern in the hypertrophied cells. In an early phase of hypertrophic growth, the frequency of spontaneous Ca(2+) transients increases, which accompanies with cytoplasm-to-nucleus translocation of CaM. In a later phase of hypertrophic growth, further increase in the frequency of spontaneous Ca(2+) transients results in the appearance of trains of Ca(2+) spikes, which accompanies with nuclear translocation of CaMKII. The cardio-protective reagent dantrolene (the reagent that corrects the de-stabilized inter-domain interaction within the RyR2 to a normal mode) ameliorates aberrant intracellular Ca(2+) events and prevents nuclear translocation of both CaM and CaMKII, then prevents the development of HT. These results suggest that translocation of CaM and CaMKII from the cytoplasm to the nucleus serves as messengers to transmit the pathogenic signal elicited in the surface membrane and in the RyR2 to the nuclear transcriptional sites to activate HT program.
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Ono M, Yano M, Hino A, Suetomi T, Xu X, Susa T, Uchinoumi H, Tateishi H, Oda T, Okuda S, Doi M, Kobayashi S, Yamamoto T, Koseki N, Kyushiki H, Ikemoto N, Matsuzaki M. Dissociation of calmodulin from cardiac ryanodine receptor causes aberrant Ca(2+) release in heart failure. Cardiovasc Res 2010; 87:609-17. [PMID: 20388639 DOI: 10.1093/cvr/cvq108] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS Calmodulin (CaM) is well known to modulate the channel function of the cardiac ryanodine receptor (RyR2). However, the possible role of CaM on the aberrant Ca(2+) release in diseased hearts remains unclear. In this study, we investigated the state of RyR2-bound CaM and channel dysfunctions in pacing-induced failing hearts. METHODS AND RESULTS The characteristics of CaM binding to RyR2 and the role of CaM on the aberrant Ca(2+) release were assessed in normal and failing canine hearts. The affinity of CaM binding to RyR2 was lower in failing sarcoplasmic reticulum (SR) than in normal SR. Addition of FK506, which dissociates FKBP12.6 from RyR2, to normal SR reduced the CaM-binding affinity. Dantrolene restored a normal level of the CaM-binding affinity in either FK506-treated (normal) SR or failing SR, suggesting that the defective inter-domain interaction between the N-terminal domain and the central domain of RyR2 (the therapeutic target of dantrolene) is involved in the reduction of the CaM-binding affinity in failing hearts. In saponin-permeabilized cardiomyocytes, the frequency of spontaneous Ca(2+) sparks was much more increased in failing cardiomyocytes than in normal cardiomyocytes, whereas the addition of a high concentration of CaM attenuated the aberrant increase of Ca(2+) sparks. CONCLUSION The defective inter-domain interaction between N-terminal and central domains within RyR2 reduces the binding affinity of CaM to RyR2, thereby causing the spontaneous Ca(2+) release events in failing hearts. Correction of the defective CaM binding may be a new strategy to protect against the aberrant Ca(2+) release in heart failure.
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Affiliation(s)
- Makoto Ono
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan
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Xu X, Yano M, Uchinoumi H, Hino A, Suetomi T, Ono M, Tateishi H, Oda T, Okuda S, Doi M, Kobayashi S, Yamamoto T, Ikeda Y, Ikemoto N, Matsuzaki M. Defective calmodulin binding to the cardiac ryanodine receptor plays a key role in CPVT-associated channel dysfunction. Biochem Biophys Res Commun 2010; 394:660-6. [PMID: 20226167 DOI: 10.1016/j.bbrc.2010.03.046] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2010] [Accepted: 03/07/2010] [Indexed: 10/19/2022]
Abstract
Calmodulin (CaM), one of the accessory proteins of the cardiac ryanodine receptor (RyR2), is known to play a significant role in the channel regulation of the RyR2. However, the possible involvement of calmodulin in the pathogenic process of catecholaminergic polymorphic ventricular tachycardia (CPVT) has not been investigated. In this study, we investigated the state of RyR2-bound CaM and channel dysfunctions using a knock-in (KI) mouse model with CPVT-linked RyR2 mutation (R2474S). Without added effectors, the affinity of CaM binding to the RyR2 was indistinguishable between KI and WT hearts. In response to cAMP (1 micromol/L), the RyR2 phosphorylation at Ser2808 increased in both WT and KI hearts to the same extent. However, cAMP caused a significant decrease of the CaM-binding affinity in KI hearts, but the affinity was unchanged in WT. Dantrolene restored a normal level of CaM-binding affinity in the cAMP-treated KI hearts, suggesting that defective inter-domain interaction between the N-terminal domain and the central domain of the RyR2 (the target of therapeutic effect of dantrolene) is involved in the cAMP-induced reduction of the CaM-binding affinity. In saponin-permeabilized cardiomyocytes, the addition of cAMP increased the frequency of spontaneous Ca(2+) sparks to a significantly larger extent in KI cardiomyocytes than in WT cardiomyocytes, whereas the addition of a high concentration of CaM attenuated the aberrant increase of Ca(2+) sparks. In conclusion, CPVT mutation causes defective inter-domain interaction, significant reduction in the ability of CaM binding to the RyR2, spontaneous Ca(2+) leak, and then lethal arrhythmia.
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Affiliation(s)
- Xiaojuan Xu
- Department of Medicine and Clinical Science, Division of Cardiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan
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Blayney LM, Jones JL, Griffiths J, Lai FA. A mechanism of ryanodine receptor modulation by FKBP12/12.6, protein kinase A, and K201. Cardiovasc Res 2010; 85:68-78. [PMID: 19661110 DOI: 10.1093/cvr/cvp273] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
AIMS Our objective was to explore the functional interdependence of protein kinase A (PKA) phosphorylation with binding of modulatory FK506 binding proteins (FKBP12/12.6) to the ryanodine receptor (RyR). RyR type 1 or type 2 was prepared from rabbit skeletal muscle or pig cardiac muscle, respectively. In heart failure, RyR2 dysfunction is implicated in fatal arrhythmia and RyR1 dysfunction is associated with muscle fatigue. A controversial underlying mechanism of RyR1/2 dysfunction is proposed to be hyperphosphorylation of RyR1/2 by PKA, causing loss of FKBP12/12.6 binding that is reversible by the experimental inhibitory drug K201 (JTV519). Phosphorylation is also a trigger for fatal arrhythmia in catecholaminergic polymorphic ventricular tachycardia associated with point mutations in RyR2. METHODS AND RESULTS Equilibrium binding kinetics of RyR1/2 to FKBP12/12.6 were measured using surface plasmon resonance (Biacore). Free Ca(2+) concentration was used to modulate the open/closed conformation of RyR1/2 channels measured using [(3)H]ryanodine binding assays. The affinity constant-K(A), for RyR1/2 binding to FKBP12/12.6, was significantly greater for the closed compared with the open conformation. The effect of phosphorylation or K201 was to reduce the K(A) of the closed conformation by increasing the rate of dissociation k(d). K201 reduced [(3)H]ryanodine binding to RyR1/2 at all free Ca(2+) concentrations including PKA phosphorylated preparations. CONCLUSION The results are explained through a model proposing that phosphorylation and K201 acted similarly to change the conformation of RyR1/2 and regulate FKBP12/12.6 binding. K201 stabilized the conformation, whereas phosphorylation facilitated a subsequent molecular event that might increase the rate of an open/closed conformational transition.
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Affiliation(s)
- Lynda M Blayney
- Department of Medicine - Cardiology, Wales Heart Research Institute, Cardiff University, Heath Park, Cardiff CF14 4XN, UK.
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Thomas NL, Maxwell C, Mukherjee S, Williams AJ. Ryanodine receptor mutations in arrhythmia: The continuing mystery of channel dysfunction. FEBS Lett 2010; 584:2153-60. [PMID: 20132818 DOI: 10.1016/j.febslet.2010.01.057] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Revised: 01/27/2010] [Accepted: 01/29/2010] [Indexed: 11/13/2022]
Abstract
Mutations in RyR2 are causative of an inherited disorder which often results in sudden cardiac death. Dysfunctional channel behaviour has been the subject of many investigations varying from single channel analysis through to complex animal models. This review discusses recent advances in the field, describes the controversy surrounding the exact consequences of RyR2 mutation and how the disparate data may be reconciled. This heterogeneity of function with respect to the effects of polymorphisms, phosphorylation, cytosolic and luminal Ca(2+) as well as inter-domain interactions may have important implications for the recent pharmaceutical therapies which have been put forward. We surmise that a comprehensive characterisation of mutations on a case-by-case basis may be beneficial for the development of specifically targeted therapies.
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Affiliation(s)
- N Lowri Thomas
- Department of Cardiology, Wales Heart Research Institute, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK.
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Qi MY, Feng Y, Dai DZ, Li N, Cheng YS, Dai Y. CPU86017, a berberine derivative, attenuates cardiac failure through normalizing calcium leakage and downregulated phospholamban and exerting antioxidant activity. Acta Pharmacol Sin 2010; 31:165-74. [PMID: 20139899 DOI: 10.1038/aps.2009.180] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
AIM To investigate whether CPU86017, a berberine derivative, attenuates heart failure by blocking calcium influx and exerting its antioxidant activity. METHODS Myocardial infarction was induced in male Sprague-Dawley rats for 17 d followed by isoproterenol (ISO) (5 mg/kg, sc) treatment for 5 d to reduce cardiac function. The rats were divided into 5 groups: sham operation, myocardial infarction (MI), MI plus ISO, and co-treated (in mg/kg, po) with either propranolol (PRO, 10) or CPU86017 (80). Hemodynamic measurements were conducted, and measurements of the redox system, calcium handling proteins and endothelin (ET) system in vivo were done. Furthermore, calcium flux studies and PLB immunocytochemistry were conducted in vitro. RESULTS Compared to sham operation, HF was evident following MI and further worsened by ISO treatment. This occurred in parallel with downregulated mRNA and protein production of SERCA2a, PLB, and FKBP12.6, and was associated with upregulation of preproET-1, endothelin converting enzyme, and PKA mRNA production in the myocardium in vivo. Calcium leakage was induced by ISO treatment of isolated beating myocytes in vitro. These changes were attenuated by treatment with either PRO or CPU86017. PLB fluorescence in myocytes was downregulated by ISO treatment, and was relieved significantly by treatment with antioxidant aminoguanidine, ascorbic acid or CPU86017 in vitro. CONCLUSION HF, calcium leakage, downregulated PLB, FKBP12.6, SERCA2a production, and upregulated PKA were caused by ISO treatment, and were abolished by CPU86017 treatment. The beneficial effects of CPU86017 are attributable to its antioxidant and calcium influx blocking effects.
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Sedej S, Heinzel FR, Walther S, Dybkova N, Wakula P, Groborz J, Gronau P, Maier LS, Vos MA, Lai FA, Napolitano C, Priori SG, Kockskämper J, Pieske B. Na+-dependent SR Ca2+ overload induces arrhythmogenic events in mouse cardiomyocytes with a human CPVT mutation. Cardiovasc Res 2010; 87:50-9. [PMID: 20080988 DOI: 10.1093/cvr/cvq007] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS Mutations in the cardiac ryanodine receptor Ca(2+) release channel, RyR2, underlie catecholaminergic polymorphic ventricular tachycardia (CPVT), an inherited life-threatening arrhythmia. CPVT is triggered by spontaneous RyR2-mediated sarcoplasmic reticulum (SR) Ca(2+) release in response to SR Ca(2+) overload during beta-adrenergic stimulation. However, whether elevated SR Ca(2+) content--in the absence of protein kinase A activation--affects RyR2 function and arrhythmogenesis in CPVT remains elusive. METHODS AND RESULTS Isolated murine ventricular myocytes harbouring a human RyR2 mutation (RyR2(R4496C+/-)) associated with CPVT were investigated in the absence and presence of 1 micromol/L JTV-519 (RyR2 stabilizer) followed by 100 micromol/L ouabain intervention to increase cytosolic [Na(+)] and SR Ca(2+) load. Changes in membrane potential and intracellular [Ca(2+)] were monitored with whole-cell patch-clamping and confocal Ca(2+) imaging, respectively. At baseline, action potentials (APs), Ca(2+) transients, fractional SR Ca(2+) release, and SR Ca(2+) load were comparable in wild-type (WT) and RyR2(R4496C+/-) myocytes. Ouabain evoked significant increases in diastolic [Ca(2+)], peak systolic [Ca(2+)], fractional SR Ca(2+) release, and SR Ca(2+) content that were quantitatively similar in WT and RyR2(R4496C+/-) myocytes. Ouabain also induced arrhythmogenic events, i.e. spontaneous Ca(2+) waves, delayed afterdepolarizations and spontaneous APs, in both groups. However, the ouabain-induced increase in the frequency of arrhythmogenic events was dramatically larger in RyR2(R4496C+/-) when compared with WT myocytes. JTV-519 greatly reduced the frequency of ouabain-induced arrhythmogenic events. CONCLUSION The elevation of SR Ca(2+) load--in the absence of beta-adrenergic stimulation--is sufficient to increase the propensity for triggered arrhythmias in RyR2(R4496C+/-) cardiomyocytes. Stabilization of RyR2 by JTV-519 effectively reduces these triggered arrhythmias.
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Affiliation(s)
- Simon Sedej
- Division of Cardiology, Medical University of Graz, Auenbruggerplatz 15, Graz A-8036, Austria
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Hirose M, Stuyvers BD, Dun W, ter Keurs HEDJ, Boyden PA. Function of Ca(2+) release channels in Purkinje cells that survive in the infarcted canine heart: a mechanism for triggered Purkinje ectopy. Circ Arrhythm Electrophysiol 2009; 1:387-95. [PMID: 19753099 DOI: 10.1161/circep.107.758110] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Triggered Purkinje ectopy can lead to the initiation of serious ventricular arrhythmias in post-myocardial infarction patients. In the canine model, Purkinje cells from the subendocardial border of the healing infarcted heart can initiate ventricular arrhythmias. Intracellular Ca(2+) abnormalities underlie these arrhythmias, yet the subcellular reasons for these abnormalities remain unknown. METHODS AND RESULTS Using 2D confocal microscopy, we directly quantify and compare typical spontaneous Ca(2+) events in specific subcellular regions of normal Purkinje cells with those Purkinje cells from the subendocardium of the 48-hour infarcted canine heart (IZPCs). The Ca(2+) event rate was higher in the subsarcolemmal region of IZPCs when compared with normal Purkinje cells; IZPC amplitudes were higher, yet the spatial extents of these events were similar. The amplitude of caffeine-releasable Ca(2+) in either the subsarcolemmal or core regions of IZPCs did not differ from normal Purkinje cells, suggesting that Ca(2+) overload was not related to the frequency change. In permeabilized Purkinje cells from both groups, the event rate was related to free [Ca(2+)] in both subsarcolemmal and core, but in IZPCs, this event rate was significantly increased at each free Ca(2+), suggesting an enhanced sensitivity to Ca(2+) release. Furthermore, decays of wide long lasting Ca(2+) release events in IZPC's core were significantly accelerated compared with those in normal Purkinje cells. JTV519 (K201) suppressed IZPC cell wide Ca(2+) waves as well as normalized the enhanced event rate and its response to free Ca(2+). CONCLUSIONS Increased spontaneous Ca(2+) release events in IZPCs are due to uniform regionally increased Ca(2+) release channel sensitivity to Ca(2+) without a change in sarcoplasmic reticulum content. In addition, Ca(2+) reuptake in IZPCs is accelerated. These properties would lower the threshold of Ca(2+) release channels, setting the stage for the highly frequent arrhythmogenic cell wide Ca(2+) waves observed in IZPCs.
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Affiliation(s)
- Masanori Hirose
- Department of Pharmacology, Center for Molecular Therapeutics, Columbia University, New York, NY, USA
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Toischer K, Lehnart SE, Tenderich G, Milting H, Körfer R, Schmitto JD, Schöndube FA, Kaneko N, Loughrey CM, Smith GL, Hasenfuss G, Seidler T. K201 improves aspects of the contractile performance of human failing myocardium via reduction in Ca2+ leak from the sarcoplasmic reticulum. Basic Res Cardiol 2009; 105:279-87. [PMID: 19718543 PMCID: PMC2807967 DOI: 10.1007/s00395-009-0057-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2009] [Revised: 08/06/2009] [Accepted: 08/20/2009] [Indexed: 11/30/2022]
Abstract
In heart failure, intracellular Ca2+ leak from cardiac ryanodine receptors (RyR2s) leads to a loss of Ca2+ from the sarcoplasmic reticulum (SR) potentially contributing to decreased function. Experimental data suggest that the 1,4-benzothiazepine K201 (JTV-519) may stabilise RyR2s and thereby reduce detrimental intracellular Ca2+ leak. Whether K201 exerts beneficial effects in human failing myocardium is unknown. Therefore, we have studied the effects of K201 on muscle preparations from failing human hearts. K201 (0.3 microM; extracellular [Ca2+]e 1.25 mM) showed no effects on contractile function and micromolar concentrations resulted in negative inotropic effects (K201 1 microM; developed tension -9.8 +/- 2.5% compared to control group; P < 0.05). Interestingly, K201 (0.3 microM) increased the post-rest potentiation (PRP) of failing myocardium after 120 s, indicating an increased SR Ca2+ load. At high [Ca2+]e concentrations (5 mmol/L), K201 increased PRP already at shorter rest intervals (30 s). Strikingly, treatment with K201 (0.3 microM) prevented diastolic dysfunction (diastolic tension at 5 mmol/L [Ca2+]e normalised to 1 mmol/L [Ca2+]e: control 1.26 +/- 0.06, K201 1.01 +/- 0.03, P < 0.01). In addition at high [Ca2+]e) K201 (0.3 microM) treatment significantly improved systolic function [developed tension +27 +/- 8% (K201 vs. control); P < 0.05]. The beneficial effects on diastolic and systolic functions occurred throughout the physiological frequency range of the human heart rate from 1 to 3 Hz. Upon elevated intracellular Ca2+ concentration, systolic and diastolic contractile functions of terminally failing human myocardium are improved by K201.
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Affiliation(s)
- Karl Toischer
- Abteilung Kardiologie und Pneumologie, Georg-August-Universität, Göttingen, Germany.
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