1
|
Jin X. The inositol trisphosphate receptor can facilitate but does not initiate ventricular arrhythmogenesis. J Physiol 2024; 602:5-8. [PMID: 38010615 DOI: 10.1113/jp285786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 11/13/2023] [Indexed: 11/29/2023] Open
Affiliation(s)
- Xin Jin
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| |
Collapse
|
2
|
Kanaporis G, Blatter LA. Increased Risk for Atrial Alternans in Rabbit Heart Failure: The Role of Ca 2+/Calmodulin-Dependent Kinase II and Inositol-1,4,5-trisphosphate Signaling. Biomolecules 2023; 14:53. [PMID: 38254653 PMCID: PMC10813785 DOI: 10.3390/biom14010053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 12/18/2023] [Accepted: 12/23/2023] [Indexed: 01/24/2024] Open
Abstract
Heart failure (HF) increases the probability of cardiac arrhythmias, including atrial fibrillation (AF), but the mechanisms linking HF to AF are poorly understood. We investigated disturbances in Ca2+ signaling and electrophysiology in rabbit atrial myocytes from normal and failing hearts and identified mechanisms that contribute to the higher risk of atrial arrhythmias in HF. Ca2+ transient (CaT) alternans-beat-to-beat alternations in CaT amplitude-served as indicator of increased arrhythmogenicity. We demonstrate that HF atrial myocytes were more prone to alternans despite no change in action potentials duration and only moderate decrease of L-type Ca2+ current. Ca2+/calmodulin-dependent kinase II (CaMKII) inhibition suppressed CaT alternans. Activation of IP3 signaling by endothelin-1 (ET-1) and angiotensin II (Ang II) resulted in acute, but transient reduction of CaT amplitude and sarcoplasmic reticulum (SR) Ca2+ load, and lowered the alternans risk. However, prolonged exposure to ET-1 and Ang II enhanced SR Ca2+ release and increased the degree of alternans. Inhibition of IP3 receptors prevented the transient ET-1 and Ang II effects and by itself increased the degree of CaT alternans. Our data suggest that activation of CaMKII and IP3 signaling contribute to atrial arrhythmogenesis in HF.
Collapse
Affiliation(s)
| | - Lothar A. Blatter
- Department of Physiology & Biophysics, Rush University Medical Center, Chicago, IL 60612, USA;
| |
Collapse
|
3
|
Jin X, Meletiou A, Chung J, Tilunaite A, Demydenko K, Dries E, Puertas RD, Amoni M, Tomar A, Claus P, Soeller C, Rajagopal V, Sipido K, Roderick HL. InsP 3R-RyR channel crosstalk augments sarcoplasmic reticulum Ca 2+ release and arrhythmogenic activity in post-MI pig cardiomyocytes. J Mol Cell Cardiol 2023; 179:47-59. [PMID: 37003353 DOI: 10.1016/j.yjmcc.2023.03.015] [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: 11/17/2022] [Revised: 03/08/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023]
Abstract
Ca2+ transients (CaT) underlying cardiomyocyte (CM) contraction require efficient Ca2+ coupling between sarcolemmal Ca2+ channels and sarcoplasmic reticulum (SR) ryanodine receptor Ca2+ channels (RyR) for their generation; reduced coupling in disease contributes to diminished CaT and arrhythmogenic Ca2+ events. SR Ca2+ release also occurs via inositol 1,4,5-trisphosphate receptors (InsP3R) in CM. While this pathway contributes negligeably to Ca2+ handling in healthy CM, rodent studies support a role in altered Ca2+ dynamics and arrhythmogenic Ca2+ release involving InsP3R crosstalk with RyRs in disease. Whether this mechanism persists in larger mammals with lower T-tubular density and coupling of RyRs is not fully resolved. We have recently shown an arrhythmogenic action of InsP3-induced Ca2+ release (IICR) in end stage human heart failure, often associated with underlying ischemic heart disease (IHD). How IICR contributes to early stages of disease is however not determined but highly relevant. To access this stage, we chose a porcine model of IHD, which shows substantial remodelling of the area adjacent to the infarct. In cells from this region, IICR preferentially augmented Ca2+ release from non-coupled RyR clusters that otherwise showed delayed activation during the CaT. IICR in turn synchronised Ca2+ release during the CaT but also induced arrhythmogenic delayed afterdepolarizations and action potentials. Nanoscale imaging identified co-clustering of InsP3Rs and RyRs, thereby allowing Ca2+-mediated channel crosstalk. Mathematical modelling supported and further delineated this mechanism of enhanced InsP3R-RyRs coupling in MI. Our findings highlight the role of InsP3R-RyR channel crosstalk in Ca2+ release and arrhythmia during post-MI remodelling.
Collapse
Affiliation(s)
- Xin Jin
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000 Leuven, Belgium
| | - Anna Meletiou
- Department of Physiology, University of Bern, Bern, Switzerland
| | - Joshua Chung
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000 Leuven, Belgium; Cell Structure and Mechanobiology Group, Department of Biomedical Engineering, Melbourne School of Engineering, University of Melbourne, Australia
| | - Agne Tilunaite
- Cell Structure and Mechanobiology Group, Department of Biomedical Engineering, Melbourne School of Engineering, University of Melbourne, Australia; Systems Biology Laboratory, School of Mathematics and Statistics, and Department of Biomedical Engineering, University of Melbourne, Australia
| | - Kateryna Demydenko
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000 Leuven, Belgium
| | - Eef Dries
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000 Leuven, Belgium
| | - Rosa Doñate Puertas
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000 Leuven, Belgium
| | - Matthew Amoni
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000 Leuven, Belgium
| | - Ashutosh Tomar
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000 Leuven, Belgium
| | - Piet Claus
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000 Leuven, Belgium
| | | | - Vijay Rajagopal
- Cell Structure and Mechanobiology Group, Department of Biomedical Engineering, Melbourne School of Engineering, University of Melbourne, Australia
| | - Karin Sipido
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000 Leuven, Belgium
| | - H Llewelyn Roderick
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000 Leuven, Belgium.
| |
Collapse
|
4
|
Chung J, Tilūnaitė A, Ladd D, Hunt H, Soeller C, Crampin EJ, Johnston ST, Roderick HL, Rajagopal V. IP 3R activity increases propensity of RyR-mediated sparks by elevating dyadic [Ca 2+]. Math Biosci 2023; 355:108923. [PMID: 36395827 DOI: 10.1016/j.mbs.2022.108923] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 10/15/2022] [Accepted: 10/15/2022] [Indexed: 11/16/2022]
Abstract
Calcium (Ca2+) plays a critical role in the excitation contraction coupling (ECC) process that mediates the contraction of cardiomyocytes during each heartbeat. While ryanodine receptors (RyRs) are the primary Ca2+ channels responsible for generating the cell-wide Ca2+ transients during ECC, Ca2+ release, via inositol 1,4,5-trisphosphate (IP3) receptors (IP3Rs) are also reported in cardiomyocytes to elicit ECC-modulating effects. Recent studies suggest that the localization of IP3Rs at dyads grant their ability to modify the occurrence of Ca2+ sparks (elementary Ca2+ release events that constitute cell wide Ca2+ releases associated with ECC) which may underlie their modulatory influence on ECC. Here, we aim to uncover the mechanism by which dyad-localized IP3Rs influence Ca2+ spark dynamics. To this end, we developed a mathematical model of the dyad that incorporates the behaviour of IP3Rs, in addition to RyRs, to reveal the impact of their activity on local Ca2+ handling and consequent Ca2+ spark occurrence and its properties. Consistent with published experimental data, our model predicts that the propensity for Ca2+ spark formation increases in the presence of IP3R activity. Our simulations support the hypothesis that IP3Rs elevate Ca2+ in the dyad, sensitizing proximal RyRs towards activation and hence Ca2+ spark formation. The stochasticity of IP3R gating is an important aspect of this mechanism. However, dyadic IP3R activity lowers the Ca2+ available in the junctional sarcoplasmic reticulum (JSR) for release, thus resulting in Ca2+ sparks with similar durations but lower amplitudes.
Collapse
Affiliation(s)
- Joshua Chung
- Department of Biomedical Engineering, The University of Melbourne, Melbourne, VIC 3010, Australia; Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, 3000, Leuven, Belgium
| | - Agnė Tilūnaitė
- Department of Biomedical Engineering, The University of Melbourne, Melbourne, VIC 3010, Australia; School of Mathematics and Statistics, The University of Melbourne, Melbourne, VIC 3010, Australia
| | - David Ladd
- Department of Biomedical Engineering, The University of Melbourne, Melbourne, VIC 3010, Australia; School of Mathematics and Statistics, The University of Melbourne, Melbourne, VIC 3010, Australia; ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, School of Chemical and Biomedical Engineering, The University of Melbourne, Melbourne, VIC 3010, Australia
| | - Hilary Hunt
- School of Mathematics and Statistics, The University of Melbourne, Melbourne, VIC 3010, Australia
| | | | - Edmund J Crampin
- Department of Biomedical Engineering, The University of Melbourne, Melbourne, VIC 3010, Australia; School of Mathematics and Statistics, The University of Melbourne, Melbourne, VIC 3010, Australia; ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, School of Chemical and Biomedical Engineering, The University of Melbourne, Melbourne, VIC 3010, Australia
| | - Stuart T Johnston
- School of Mathematics and Statistics, The University of Melbourne, Melbourne, VIC 3010, Australia; ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, School of Chemical and Biomedical Engineering, The University of Melbourne, Melbourne, VIC 3010, Australia
| | - H Llewelyn Roderick
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, 3000, Leuven, Belgium.
| | - Vijay Rajagopal
- Department of Biomedical Engineering, The University of Melbourne, Melbourne, VIC 3010, Australia; Baker Department of Cardiometabolic Health, The University of Melbourne, Melbourne, VIC 3010, Australia.
| |
Collapse
|
5
|
Tang N, Tian W, Ma GY, Xiao X, Zhou L, Li ZZ, Liu XX, Li CY, Wu KH, Liu W, Wang XY, Gao YY, Yang X, Qi J, Li D, Liu Y, Chen WS, Gao J, Li XQ, Cao W. TRPC channels blockade abolishes endotoxemic cardiac dysfunction by hampering intracellular inflammation and Ca 2+ leakage. Nat Commun 2022; 13:7455. [PMID: 36460692 PMCID: PMC9718841 DOI: 10.1038/s41467-022-35242-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 11/23/2022] [Indexed: 12/04/2022] Open
Abstract
Intracellular Ca2+ dysregulation is a key marker in septic cardiac dysfunction; however, regulation of the classic Ca2+ regulatory modules cannot successfully abolish this symptom. Here we show that the knockout of transient receptor potential canonical (TRPC) channel isoforms TRPC1 and TRPC6 can ameliorate LPS-challenged heart failure and prolong survival in mice. The LPS-triggered Ca2+ release from the endoplasmic reticulum both in cardiomyocytes and macrophages is significantly inhibited by Trpc1 or Trpc6 knockout. Meanwhile, TRPC's molecular partner - calmodulin - is uncoupled during Trpc1 or Trpc6 deficiency and binds to TLR4's Pococurante site and atypical isoleucine-glutamine-like motif to block the inflammation cascade. Blocking the C-terminal CaM/IP3R binding domain in TRPC with chemical inhibitor could obstruct the Ca2+ leak and TLR4-mediated inflammation burst, demonstrating a cardioprotective effect in endotoxemia and polymicrobial sepsis. Our findings provide insight into the pathogenesis of endotoxemic cardiac dysfunction and suggest a novel approach for its treatment.
Collapse
Affiliation(s)
- Na Tang
- grid.144022.10000 0004 1760 4150Department of Pharmacy, School of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shaanxi China ,grid.144022.10000 0004 1760 4150Shaanxi Key Laboratory of Natural Products & Chemical Biology, Northwest A&F University, Yangling, Shaanxi China
| | - Wen Tian
- grid.233520.50000 0004 1761 4404Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi’an, Shaanxi China ,grid.233520.50000 0004 1761 4404Key Laboratory of Gastrointestinal Pharmacology of Chinese Materia Medica of the State Administration of Traditional Chinese Medicine, Fourth Military Medical University, Xi’an, Shaanxi China
| | - Guang-Yuan Ma
- grid.144022.10000 0004 1760 4150Department of Pharmacy, School of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shaanxi China ,grid.144022.10000 0004 1760 4150Shaanxi Key Laboratory of Natural Products & Chemical Biology, Northwest A&F University, Yangling, Shaanxi China
| | - Xiong Xiao
- grid.233520.50000 0004 1761 4404Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi’an, Shaanxi China ,grid.233520.50000 0004 1761 4404Key Laboratory of Gastrointestinal Pharmacology of Chinese Materia Medica of the State Administration of Traditional Chinese Medicine, Fourth Military Medical University, Xi’an, Shaanxi China
| | - Lei Zhou
- grid.144022.10000 0004 1760 4150Department of Pharmacy, School of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shaanxi China ,grid.144022.10000 0004 1760 4150Shaanxi Key Laboratory of Natural Products & Chemical Biology, Northwest A&F University, Yangling, Shaanxi China
| | - Ze-Zhi Li
- grid.144022.10000 0004 1760 4150Department of Pharmacy, School of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shaanxi China ,grid.144022.10000 0004 1760 4150Shaanxi Key Laboratory of Natural Products & Chemical Biology, Northwest A&F University, Yangling, Shaanxi China
| | - Xiao-Xiao Liu
- grid.233520.50000 0004 1761 4404Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi’an, Shaanxi China ,grid.233520.50000 0004 1761 4404Key Laboratory of Gastrointestinal Pharmacology of Chinese Materia Medica of the State Administration of Traditional Chinese Medicine, Fourth Military Medical University, Xi’an, Shaanxi China
| | - Chong-Yao Li
- grid.412262.10000 0004 1761 5538Department of Pharmacy, Xi’an No.3 Hospital, the Affiliated Hospital of Northwest University, Xi’an, Shaanxi China
| | - Ke-Han Wu
- grid.144022.10000 0004 1760 4150Department of Pharmacy, School of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shaanxi China ,grid.144022.10000 0004 1760 4150Shaanxi Key Laboratory of Natural Products & Chemical Biology, Northwest A&F University, Yangling, Shaanxi China
| | - Wenjuan Liu
- grid.144022.10000 0004 1760 4150Department of Pharmacy, School of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shaanxi China
| | - Xue-Ying Wang
- grid.233520.50000 0004 1761 4404Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi’an, Shaanxi China ,grid.233520.50000 0004 1761 4404Key Laboratory of Gastrointestinal Pharmacology of Chinese Materia Medica of the State Administration of Traditional Chinese Medicine, Fourth Military Medical University, Xi’an, Shaanxi China
| | - Yuan-Yuan Gao
- grid.233520.50000 0004 1761 4404Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi’an, Shaanxi China ,grid.233520.50000 0004 1761 4404Key Laboratory of Gastrointestinal Pharmacology of Chinese Materia Medica of the State Administration of Traditional Chinese Medicine, Fourth Military Medical University, Xi’an, Shaanxi China
| | - Xin Yang
- grid.144022.10000 0004 1760 4150Department of Pharmacy, School of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shaanxi China ,grid.144022.10000 0004 1760 4150Shaanxi Key Laboratory of Natural Products & Chemical Biology, Northwest A&F University, Yangling, Shaanxi China
| | - Jianzhao Qi
- grid.144022.10000 0004 1760 4150Shaanxi Key Laboratory of Natural Products & Chemical Biology, Northwest A&F University, Yangling, Shaanxi China
| | - Ding Li
- grid.144022.10000 0004 1760 4150Shaanxi Key Laboratory of Natural Products & Chemical Biology, Northwest A&F University, Yangling, Shaanxi China
| | - Yang Liu
- grid.233520.50000 0004 1761 4404Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi China
| | - Wen-Sheng Chen
- grid.233520.50000 0004 1761 4404Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi China ,Department of Cardiovascular Surgery, Xi’an Gaoxin Hospital, Xi’an, Shaanxi China
| | - Jinming Gao
- grid.144022.10000 0004 1760 4150Department of Pharmacy, School of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shaanxi China ,grid.144022.10000 0004 1760 4150Shaanxi Key Laboratory of Natural Products & Chemical Biology, Northwest A&F University, Yangling, Shaanxi China
| | - Xiao-Qiang Li
- grid.233520.50000 0004 1761 4404Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Xi’an, Shaanxi China ,grid.233520.50000 0004 1761 4404Key Laboratory of Gastrointestinal Pharmacology of Chinese Materia Medica of the State Administration of Traditional Chinese Medicine, Fourth Military Medical University, Xi’an, Shaanxi China
| | - Wei Cao
- grid.144022.10000 0004 1760 4150Department of Pharmacy, School of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shaanxi China ,grid.144022.10000 0004 1760 4150Shaanxi Key Laboratory of Natural Products & Chemical Biology, Northwest A&F University, Yangling, Shaanxi China
| |
Collapse
|
6
|
Demydenko K, Ekhteraei-Tousi S, Roderick HL. Inositol 1,4,5-trisphosphate receptors in cardiomyocyte physiology and disease. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210319. [PMID: 36189803 PMCID: PMC9527928 DOI: 10.1098/rstb.2021.0319] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The contraction of cardiac muscle underlying the pumping action of the heart is mediated by the process of excitation-contraction coupling (ECC). While triggered by Ca2+ entry across the sarcolemma during the action potential, it is the release of Ca2+ from the sarcoplasmic reticulum (SR) intracellular Ca2+ store via ryanodine receptors (RyRs) that plays the major role in induction of contraction. Ca2+ also acts as a key intracellular messenger regulating transcription underlying hypertrophic growth. Although Ca2+ release via RyRs is by far the greatest contributor to the generation of Ca2+ transients in the cardiomyocyte, Ca2+ is also released from the SR via inositol 1,4,5-trisphosphate (InsP3) receptors (InsP3Rs). This InsP3-induced Ca2+ release modifies Ca2+ transients during ECC, participates in directing Ca2+ to the mitochondria, and stimulates the transcription of genes underlying hypertrophic growth. Central to these specific actions of InsP3Rs is their localization to responsible signalling microdomains, the dyad, the SR-mitochondrial interface and the nucleus. In this review, the various roles of InsP3R in cardiac (patho)physiology and the mechanisms by which InsP3 signalling selectively influences the different cardiomyocyte cell processes in which it is involved will be presented. This article is part of the theme issue ‘The cardiomyocyte: new revelations on the interplay between architecture and function in growth, health, and disease’.
Collapse
Affiliation(s)
- Kateryna Demydenko
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Samaneh Ekhteraei-Tousi
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - H Llewelyn Roderick
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| |
Collapse
|
7
|
Jin X, Amoni M, Gilbert G, Dries E, Doñate Puertas R, Tomar A, Nagaraju CK, Pradhan A, Yule DI, Martens T, Menten R, Vanden Berghe P, Rega F, Sipido K, Roderick HL. InsP 3R-RyR Ca 2+ channel crosstalk facilitates arrhythmias in the failing human ventricle. Basic Res Cardiol 2022; 117:60. [PMID: 36378362 DOI: 10.1007/s00395-022-00967-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 10/13/2022] [Accepted: 10/31/2022] [Indexed: 11/16/2022]
Abstract
Dysregulated intracellular Ca2+ handling involving altered Ca2+ release from intracellular stores via RyR channels underlies both arrhythmias and reduced function in heart failure (HF). Mechanisms linking RyR dysregulation and disease are not fully established. Studies in animals support a role for InsP3 receptor Ca2+ channels (InsP3R) in pathological alterations in cardiomyocyte Ca2+ handling but whether these findings translate to the divergent physiology of human cardiomyocytes during heart failure is not determined. Using electrophysiological and Ca2+ recordings in human ventricular cardiomyocytes, we uncovered that Ca2+ release via InsP3Rs facilitated Ca2+ release from RyR and induced arrhythmogenic delayed after depolarisations and action potentials. InsP3R-RyR crosstalk was particularly increased in HF at RyR clusters isolated from the T-tubular network. Reduced SERCA activity in HF further facilitated the action of InsP3. Nanoscale imaging revealed co-localisation of InsP3Rs with RyRs in the dyad, which was increased in HF, providing a mechanism for augmented Ca2+ channel crosstalk. Notably, arrhythmogenic activity dependent on InsP3Rs was increased in tissue wedges from failing hearts perfused with AngII to promote InsP3 generation. These data indicate a central role for InsP3R-RyR Ca2+ signalling crosstalk in the pro-arrhythmic action of GPCR agonists elevated in HF and the potential for their therapeutic targeting.
Collapse
Affiliation(s)
- Xin Jin
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium.,Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Matthew Amoni
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium
| | - Guillaume Gilbert
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium
| | - Eef Dries
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium
| | - Rosa Doñate Puertas
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium
| | - Ashutosh Tomar
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium
| | - Chandan K Nagaraju
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium
| | - Ankit Pradhan
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium
| | - David I Yule
- Department of Pharmacology and Physiology, Medical Center School of Medicine and Dentistry, University of Rochester, 601 Elmwood Avenue, Box 711, Rochester, NY, 14642, USA
| | - Tobie Martens
- Laboratory for Enteric NeuroScience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), KU Leuven, 3000, Leuven, Belgium.,Cell and Tissue Imaging Cluster (CIC), KU Leuven, 3000, Leuven, Belgium
| | - Roxane Menten
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium
| | - Pieter Vanden Berghe
- Laboratory for Enteric NeuroScience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), KU Leuven, 3000, Leuven, Belgium.,Cell and Tissue Imaging Cluster (CIC), KU Leuven, 3000, Leuven, Belgium
| | - Filip Rega
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium.,Department of Cardiology and Department of Cardiac Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Karin Sipido
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium
| | - H Llewelyn Roderick
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium.
| |
Collapse
|
8
|
Hamilton S, Terentyev D. ER stress and calcium-dependent arrhythmias. Front Physiol 2022; 13:1041940. [PMID: 36425292 PMCID: PMC9679650 DOI: 10.3389/fphys.2022.1041940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Accepted: 10/24/2022] [Indexed: 11/11/2022] Open
Abstract
The sarcoplasmic reticulum (SR) plays the key role in cardiac function as the major source of Ca2+ that activates cardiomyocyte contractile machinery. Disturbances in finely-tuned SR Ca2+ release by SR Ca2+ channel ryanodine receptor (RyR2) and SR Ca2+ reuptake by SR Ca2+-ATPase (SERCa2a) not only impair contraction, but also contribute to cardiac arrhythmia trigger and reentry. Besides being the main Ca2+ storage organelle, SR in cardiomyocytes performs all the functions of endoplasmic reticulum (ER) in other cell types including protein synthesis, folding and degradation. In recent years ER stress has become recognized as an important contributing factor in many cardiac pathologies, including deadly ventricular arrhythmias. This brief review will therefore focus on ER stress mechanisms in the heart and how these changes can lead to pro-arrhythmic defects in SR Ca2+ handling machinery.
Collapse
Affiliation(s)
- Shanna Hamilton
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, United States,Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, United States,*Correspondence: Shanna Hamilton,
| | - Dmitry Terentyev
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, United States,Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, United States
| |
Collapse
|
9
|
Chen Y, Lu Y, Wu W, Lin Y, Chen Y, Chen S, Chen Y. Advanced glycation end products modulate electrophysiological remodeling of right ventricular outflow tract cardiomyocytes: A novel target for diabetes-related ventricular arrhythmogenesis. Physiol Rep 2022; 10:e15499. [PMID: 36325589 PMCID: PMC9630757 DOI: 10.14814/phy2.15499] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 09/11/2022] [Accepted: 10/08/2022] [Indexed: 06/16/2023] Open
Abstract
Diabetes mellitus is associated with cardiovascular disease and cardiac arrhythmia. Accumulation of advanced glycation end products closely correlates with cardiovascular complications through mitochondrial dysfunction or oxidative stress and evoke proliferative, inflammatory, and fibrotic reactions, which might impair cardiac electrophysiological characteristics and increase the incidence of cardiac arrhythmia. This study examined the mechanisms how advanced glycation end products may contribute to arrhythmogenesis of right ventricular outflow tract-a unique arrhythmogenic substrate. A whole-cell patch clamp, conventional electrophysiological study, fluorescence imaging, Western blot, and confocal microscope were used to study the electrical activity, and Ca2+ homeostasis or signaling in isolated right ventricular outflow tract myocytes with and without advanced glycation end products (100 μg/ml). The advanced glycation end products treated right ventricular outflow tract myocytes had a similar action potential duration as the controls, but exhibited a lower L-type Ca2+ current, higher late sodium current and transient outward current. Moreover, the advanced glycation end products treated right ventricular outflow tract myocytes had more intracellular Na+ , reverse mode Na+ -Ca2+ exchanger currents, intracellular and mitochondrial reactive oxygen species, and less intracellular Ca2+ transient and sarcoplasmic reticulum Ca2+ content with upregulated calcium homeostasis proteins and advanced glycation end products related signaling pathway proteins. In conclusions, advanced glycation end products modulate right ventricular outflow tract electrophysiological characteristics with larger late sodium current, intracellular Na+ , reverse mode Na+ -Ca2+ exchanger currents, and disturbed Ca2+ homeostasis through increased oxidative stress mediated by the activation of the advanced glycation end products signaling pathway.
Collapse
Affiliation(s)
- Yao‐Chang Chen
- Department of Biomedical EngineeringNational Defense Medical CenterTaipeiTaiwan
| | - Yen‐Yu Lu
- Division of CardiologySijhih Cathay General HospitalNew Taipei CityTaiwan
- School of Medicine, College of MedicineFu Jen Catholic UniversityNew Taipei CityTaiwan
| | - Wen‐Shiann Wu
- Department of CardiologyChi‐Mei Medical CenterTainanTaiwan
| | - Yung‐Kuo Lin
- Taipei Heart Institute, Taipei Medical UniversityTaipeiTaiwan
- Division of Cardiovascular Medicine, Department of Internal MedicineWan Fang Hospital, Taipei Medical UniversityTaipeiTaiwan
- Division of Cardiology, Department of Internal Medicine, School of Medicine, College of MedicineTaipei Medical UniversityTaipeiTaiwan
| | - Yi‐Ann Chen
- Division of CardiologySijhih Cathay General HospitalNew Taipei CityTaiwan
- Division of NephrologySijhih Cathay General HospitalNew Taipei CityTaiwan
| | - Shih‐Ann Chen
- Heart Rhythm Center, Division of Cardiology, Department of MedicineTaipei Veterans General HospitalTaipeiTaiwan
- Cardiovascular Center, Taichung Veterans General HospitalTaichungTaiwan
- Department of Post‐Baccalaureate Medicine, College of MedicineNational Chung Hsing UniversityTaichungTaiwan
| | - Yi‐Jen Chen
- Taipei Heart Institute, Taipei Medical UniversityTaipeiTaiwan
- Division of Cardiovascular Medicine, Department of Internal MedicineWan Fang Hospital, Taipei Medical UniversityTaipeiTaiwan
- Graduate Institute of Clinical Medicine, College of MedicineTaipei Medical UniversityTaipeiTaiwan
- Cardiovascular Research CenterWan Fang Hospital, Taipei Medical UniversityTaipeiTaiwan
| |
Collapse
|
10
|
Banerjee S, Hong J, Umar S. Comparative analysis of right ventricular metabolic reprogramming in pre-clinical rat models of severe pulmonary hypertension-induced right ventricular failure. Front Cardiovasc Med 2022; 9:935423. [PMID: 36158812 PMCID: PMC9500217 DOI: 10.3389/fcvm.2022.935423] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 08/25/2022] [Indexed: 12/14/2022] Open
Abstract
Background Pulmonary hypertension (PH) leads to right ventricular (RV) hypertrophy and failure (RVF). The precise mechanisms of the metabolic basis of maladaptive PH-induced RVF (PH-RVF) are yet to be fully elucidated. Here we performed a comparative analysis of RV-metabolic reprogramming in MCT and Su/Hx rat models of severe PH-RVF using targeted metabolomics and multi-omics. Methods Male Sprague Dawley rats (250–300 gm; n = 15) were used. Rats received subcutaneous monocrotaline (60 mg/kg; MCT; n = 5) and followed for ~30-days or Sugen (20 mg/kg; Su/Hx; n = 5) followed by hypoxia (10% O2; 3-weeks) and normoxia (2-weeks). Controls received saline (Control; n = 5). Serial echocardiography was performed to assess cardiopulmonary hemodynamics. Terminal RV-catheterization was performed to assess PH. Targeted metabolomics was performed on RV tissue using UPLC-MS. RV multi-omics analysis was performed integrating metabolomic and transcriptomic datasets using Joint Pathway Analysis (JPA). Results MCT and Su/Hx rats developed severe PH, RV-hypertrophy and decompensated RVF. Targeted metabolomics of RV of MCT and Su/Hx rats detected 126 and 125 metabolites, respectively. There were 28 and 24 metabolites significantly altered in RV of MCT and Su/Hx rats, respectively, including 11 common metabolites. Common significantly upregulated metabolites included aspartate and GSH, whereas downregulated metabolites included phosphate, α-ketoglutarate, inositol, glutamine, 5-Oxoproline, hexose phosphate, creatine, pantothenic acid and acetylcarnitine. JPA highlighted common genes and metabolites from key pathways such as glycolysis, fatty acid metabolism, oxidative phosphorylation, TCA cycle, etc. Conclusions Comparative analysis of metabolic reprogramming of RV from MCT and Su/Hx rats reveals common and distinct metabolic signatures which may serve as RV-specific novel therapeutic targets for PH-RVF.
Collapse
Affiliation(s)
- Somanshu Banerjee
- Division of Molecular Medicine, Department of Anesthesiology and Perioperative Medicine, Los Angeles, CA, United States
| | - Jason Hong
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles, CA, United States
| | - Soban Umar
- Division of Molecular Medicine, Department of Anesthesiology and Perioperative Medicine, Los Angeles, CA, United States
| |
Collapse
|
11
|
Bose SJ, Read MJ, Akerman E, Capel RA, Ayagama T, Russell A, Terrar DA, Zaccolo M, Burton RAB. Inhibition of adenylyl cyclase 1 by ST034307 inhibits IP 3-evoked changes in sino-atrial node beat rate. Front Pharmacol 2022; 13:951897. [PMID: 36105228 PMCID: PMC9465815 DOI: 10.3389/fphar.2022.951897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 08/01/2022] [Indexed: 11/13/2022] Open
Abstract
Atrial arrhythmias, such as atrial fibrillation (AF), are a major mortality risk and a leading cause of stroke. The IP3 signalling pathway has been proposed as an atrial-specific target for AF therapy, and atrial IP3 signalling has been linked to the activation of calcium sensitive adenylyl cyclases AC1 and AC8. We investigated the involvement of AC1 in the response of intact mouse atrial tissue and isolated guinea pig atrial and sino-atrial node (SAN) cells to the α-adrenoceptor agonist phenylephrine (PE) using the selective AC1 inhibitor ST034307. The maximum rate change of spontaneously beating mouse right atrial tissue exposed to PE was reduced from 14.5% to 8.2% (p = 0.005) in the presence of 1 μM ST034307, whereas the increase in tension generated in paced left atrial tissue in the presence of PE was not inhibited by ST034307 (Control = 14.2%, ST034307 = 16.3%; p > 0.05). Experiments were performed using isolated guinea pig atrial and SAN cells loaded with Fluo-5F-AM to record changes in calcium transients (CaT) generated by 10 μM PE in the presence and absence of 1 μM ST034307. ST034307 significantly reduced the beating rate of SAN cells (0.34-fold decrease; p = 0.003) but did not inhibit changes in CaT amplitude in response to PE in atrial cells. The results presented here demonstrate pharmacologically the involvement of AC1 in the downstream response of atrial pacemaker activity to α-adrenoreceptor stimulation and IP3R calcium release.
Collapse
Affiliation(s)
- Samuel J. Bose
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Matthew J. Read
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Emily Akerman
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Rebecca A. Capel
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Thamali Ayagama
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Angela Russell
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - Derek A. Terrar
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Manuela Zaccolo
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | | |
Collapse
|
12
|
Varma D, Almeida JFQ, DeSantiago J, Blatter LA, Banach K. Inositol 1,4,5-trisphosphate receptor - reactive oxygen signaling domain regulates excitation-contraction coupling in atrial myocytes. J Mol Cell Cardiol 2022; 163:147-155. [PMID: 34755642 PMCID: PMC8826595 DOI: 10.1016/j.yjmcc.2021.10.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 09/03/2021] [Accepted: 10/13/2021] [Indexed: 02/03/2023]
Abstract
The inositol 1,4,5-trisphosphate receptor (InsP3R) is up-regulated in patients with atrial fibrillation (AF) and InsP3-induced Ca2+ release (IICR) is linked to pro-arrhythmic spontaneous Ca2+ release events. Nevertheless, knowledge of the physiological relevance and regulation of InsP3Rs in atrial muscle is still limited. We hypothesize that InsP3R and NADPH oxidase 2 (NOX2) form a functional signaling domain where NOX2 derived reactive oxygen species (ROS) regulate InsP3R agonist affinity and thereby Ca2+ release. To quantitate the contribution of IICR to atrial excitation-contraction coupling (ECC) atrial myocytes (AMs) were isolated from wild type and NOX2 deficient (Nox2-/-) mice and changes in the cytoplasmic Ca2+ concentration ([Ca2+]i; fluo-4/AM, indo-1) or ROS (2',7'-dichlorofluorescein, DCF) were monitored by fluorescence microscopy. Superfusion of AMs with Angiotensin II (AngII: 1 μmol/L) significantly increased diastolic [Ca2+]i (F/F0, Ctrl: 1.00 ± 0.01, AngII: 1.20 ± 0.03; n = 7; p < 0.05), the field stimulation induced Ca2+ transient (CaT) amplitude (ΔF/F0, Ctrl: 2.00 ± 0.17, AngII: 2.39 ± 0.22, n = 7; p < 0.05), and let to the occurrence of spontaneous increases in [Ca2+]i. These changes in [Ca2+]i were suppressed by the InsP3R blocker 2-aminoethoxydiphenyl-borate (2-APB; 1 μmol/L). Concomitantly, AngII induced an increase in ROS production that was sensitive to the NOX2 specific inhibitor gp91ds-tat (1 μmol/L). In NOX2-/- AMs, AngII failed to increase diastolic [Ca2+]i, CaT amplitude, and the frequency of spontaneous Ca2+ increases. Furthermore, the enhancement of CaTs by exposure to membrane permeant InsP3 was abolished by NOX inhibition with apocynin (1 μM). AngII induced IICR in Nox2-/- AMs could be restored by addition of exogenous ROS (tert-butyl hydroperoxide, tBHP: 5 μmol/L). In saponin permeabilized AMs InsP3 (5 μmol/L) induced Ca2+ sparks that increased in frequency in the presence of ROS (InsP3: 9.65 ± 1.44 sparks*s-1*(100μm)-1; InsP3 + tBHP: 10.77 ± 1.5 sparks*s-1*(100μm)-1; n = 5; p < 0.05). The combined effect of InsP3 + tBHP was entirely suppressed by 2-APB and Xestospongine C (XeC). Changes in IICR due to InsP3R glutathionylation induced by diamide could be reversed by the reducing agent dithiothreitol (DTT: 1 mmol/L) and prevented by pretreatment with 2-APB, supporting that the ROS-dependent post-translational modification of the InsP3R plays a role in the regulation of ECC. Our data demonstrate that in AMs the InsP3R is under dual control of agonist induced InsP3 and ROS formation and suggest that InsP3 and NOX2-derived ROS co-regulate atrial IICR and ECC in a defined InsP3R/NOX2 signaling domain.
Collapse
Affiliation(s)
- Disha Varma
- Dept. of Internal Medicine/Cardiology, Rush University Medical Center, 1750 W. Harrison St, Chicago, IL 60612, USA.
| | - Jonathas F Q Almeida
- Dept. of Internal Medicine/Cardiology, Rush University Medical Center, 1750 W. Harrison St, Chicago, IL 60612, USA.
| | - Jaime DeSantiago
- Dept. of Physiology & Biophysics, Rush University Medical Center, 1750 W. Harrison St, Chicago, IL 60612, USA.
| | - Lothar A Blatter
- Dept. of Physiology & Biophysics, Rush University Medical Center, 1750 W. Harrison St, Chicago, IL 60612, USA.
| | - Kathrin Banach
- Dept. of Internal Medicine/Cardiology, Rush University Medical Center, 1750 W. Harrison St, Chicago, IL 60612, USA.
| |
Collapse
|
13
|
Turner D, Kang C, Mesirca P, Hong J, Mangoni ME, Glukhov AV, Sah R. Electrophysiological and Molecular Mechanisms of Sinoatrial Node Mechanosensitivity. Front Cardiovasc Med 2021; 8:662410. [PMID: 34434970 PMCID: PMC8382116 DOI: 10.3389/fcvm.2021.662410] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 06/24/2021] [Indexed: 01/01/2023] Open
Abstract
The understanding of the electrophysiological mechanisms that underlie mechanosensitivity of the sinoatrial node (SAN), the primary pacemaker of the heart, has been evolving over the past century. The heart is constantly exposed to a dynamic mechanical environment; as such, the SAN has numerous canonical and emerging mechanosensitive ion channels and signaling pathways that govern its ability to respond to both fast (within second or on beat-to-beat manner) and slow (minutes) timescales. This review summarizes the effects of mechanical loading on the SAN activity and reviews putative candidates, including fast mechanoactivated channels (Piezo, TREK, and BK) and slow mechanoresponsive ion channels [including volume-regulated chloride channels and transient receptor potential (TRP)], as well as the components of mechanochemical signal transduction, which may contribute to SAN mechanosensitivity. Furthermore, we examine the structural foundation for both mechano-electrical and mechanochemical signal transduction and discuss the role of specialized membrane nanodomains, namely, caveolae, in mechanical regulation of both membrane and calcium clock components of the so-called coupled-clock pacemaker system responsible for SAN automaticity. Finally, we emphasize how these mechanically activated changes contribute to the pathophysiology of SAN dysfunction and discuss controversial areas necessitating future investigations. Though the exact mechanisms of SAN mechanosensitivity are currently unknown, identification of such components, their impact into SAN pacemaking, and pathological remodeling may provide new therapeutic targets for the treatment of SAN dysfunction and associated rhythm abnormalities.
Collapse
Affiliation(s)
- Daniel Turner
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, United States
| | - Chen Kang
- Cardiovascular Division, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Pietro Mesirca
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Juan Hong
- Cardiovascular Division, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Matteo E Mangoni
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Alexey V Glukhov
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, United States
| | - Rajan Sah
- Cardiovascular Division, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, United States
| |
Collapse
|
14
|
Arslanova A, Shafaattalab S, Lin E, Barszczewski T, Hove-Madsen L, Tibbits GF. Investigating inherited arrhythmias using hiPSC-derived cardiomyocytes. Methods 2021; 203:542-557. [PMID: 34197925 DOI: 10.1016/j.ymeth.2021.06.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 06/22/2021] [Accepted: 06/23/2021] [Indexed: 10/21/2022] Open
Abstract
Fundamental to the functional behavior of cardiac muscle is that the cardiomyocytes are integrated as a functional syncytium. Disrupted electrical activity in the cardiac tissue can lead to serious complications including cardiac arrhythmias. Therefore, it is important to study electrophysiological properties of the cardiac tissue. With advancements in stem cell research, protocols for the production of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have been established, providing great potential in modelling cardiac arrhythmias and drug testing. The hiPSC-CM model can be used in conjunction with electrophysiology-based platforms to examine the electrical activity of the cardiac tissue. Techniques for determining the myocardial electrical activity include multielectrode arrays (MEAs), optical mapping (OM), and patch clamping. These techniques provide critical approaches to investigate cardiac electrical abnormalities that underlie arrhythmias.
Collapse
Affiliation(s)
- Alia Arslanova
- Molecular Cardiac Physiology Group, Department of Biomedical Physiology and Kinesiology, Simon Fraser, University, Burnaby, BC V5A 1S6, Canada; hiPSC-CM Research Team, British Columbia Children's Hospital Research Institute, Vancouver, BC V5Z4H4, Canada
| | - Sanam Shafaattalab
- Molecular Cardiac Physiology Group, Department of Biomedical Physiology and Kinesiology, Simon Fraser, University, Burnaby, BC V5A 1S6, Canada; hiPSC-CM Research Team, British Columbia Children's Hospital Research Institute, Vancouver, BC V5Z4H4, Canada
| | - Eric Lin
- Molecular Cardiac Physiology Group, Department of Biomedical Physiology and Kinesiology, Simon Fraser, University, Burnaby, BC V5A 1S6, Canada
| | - Tiffany Barszczewski
- Molecular Cardiac Physiology Group, Department of Biomedical Physiology and Kinesiology, Simon Fraser, University, Burnaby, BC V5A 1S6, Canada; hiPSC-CM Research Team, British Columbia Children's Hospital Research Institute, Vancouver, BC V5Z4H4, Canada
| | - Leif Hove-Madsen
- Cardiac Rhythm and Contraction Group, IIBB-CSIC, Hospital de la Santa Creu i Sant Pau, Barcelona 08041, Spain; CIBERCV, Hospital de la Santa Creu i Sant Pau, Barcelona 08041, Spain; IIB Sant Pau, Hospital de la Santa Creu i Sant Pau, Barcelona 08041, Spain
| | - Glen F Tibbits
- Molecular Cardiac Physiology Group, Department of Biomedical Physiology and Kinesiology, Simon Fraser, University, Burnaby, BC V5A 1S6, Canada; hiPSC-CM Research Team, British Columbia Children's Hospital Research Institute, Vancouver, BC V5Z4H4, Canada; Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada.
| |
Collapse
|
15
|
Hamilton S, Terentyeva R, Clements RT, Belevych AE, Terentyev D. Sarcoplasmic reticulum-mitochondria communication; implications for cardiac arrhythmia. J Mol Cell Cardiol 2021; 156:105-113. [PMID: 33857485 DOI: 10.1016/j.yjmcc.2021.04.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 03/15/2021] [Accepted: 04/05/2021] [Indexed: 12/11/2022]
Abstract
Sudden cardiac death due to ventricular tachyarrhythmias remains the major cause of mortality in the world. Heart failure, diabetic cardiomyopathy, old age-related cardiac dysfunction and inherited disorders are associated with enhanced propensity to malignant cardiac arrhythmias. Both defective mitochondrial function and abnormal intracellular Ca2+ homeostasis have been established as the key contributing factors in the pathophysiology and arrhythmogenesis in these conditions. This article reviews current advances in understanding of bidirectional control of ryanodine receptor-mediated sarcoplasmic reticulum Ca2+ release and mitochondrial function, and how defects in crosstalk between these two organelles increase arrhythmic risk in cardiac disease.
Collapse
Affiliation(s)
- Shanna Hamilton
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Wexner Medical Center, The Ohio State University, Columbus, OH, United States of America
| | - Radmila Terentyeva
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Wexner Medical Center, The Ohio State University, Columbus, OH, United States of America
| | - Richard T Clements
- Biomedical & Pharmaceutical Sciences, University of Rhode Island, Kingston, RI, United States of America
| | - Andriy E Belevych
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Wexner Medical Center, The Ohio State University, Columbus, OH, United States of America
| | - Dmitry Terentyev
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Wexner Medical Center, The Ohio State University, Columbus, OH, United States of America.
| |
Collapse
|
16
|
Zhou X, Li A, Lin PH, Zhou J, Ma J. TRIC-A regulates intracellular Ca 2+ homeostasis in cardiomyocytes. Pflugers Arch 2021; 473:547-556. [PMID: 33474637 PMCID: PMC7940156 DOI: 10.1007/s00424-021-02513-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 12/14/2020] [Accepted: 01/04/2021] [Indexed: 01/26/2023]
Abstract
Trimeric intracellular cation (TRIC) channels have been identified as monovalent cation channels that are located in the ER/SR membrane. Two isoforms discovered in mammals are TRIC-A (TMEM38a) and TRIC-B (TMEM38b). TRIC-B ubiquitously expresses in all tissues, and TRIC-B-/- mice is lethal at the neonatal stage. TRIC-A mainly expresses in excitable cells. TRIC-A-/- mice survive normally but show abnormal SR Ca2+ handling in both skeletal and cardiac muscle cells. Importantly, TRIC-A mutations have been identified in human patients with stress-induced arrhythmia. In the past decade, important discoveries have been made to understand the structure and function of TRIC channels, especially its role in regulating intracellular Ca2+ homeostasis. In this review article, we focus on the potential roles of TRIC-A in regulating cardiac function, particularly its effects on intracellular Ca2+ signaling of cardiomyocytes and discuss the current knowledge gaps.
Collapse
Affiliation(s)
- Xinyu Zhou
- Department of Surgery, The Ohio State University Columbus, Columbus, OH, 43210, USA
| | - Ang Li
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, 76019, USA
| | - Pei-Hui Lin
- Department of Surgery, The Ohio State University Columbus, Columbus, OH, 43210, USA
| | - Jingsong Zhou
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, 76019, USA
| | - Jianjie Ma
- Department of Surgery, The Ohio State University Columbus, Columbus, OH, 43210, USA.
| |
Collapse
|
17
|
Blatter LA, Kanaporis G, Martinez-Hernandez E, Oropeza-Almazan Y, Banach K. Excitation-contraction coupling and calcium release in atrial muscle. Pflugers Arch 2021; 473:317-329. [PMID: 33398498 DOI: 10.1007/s00424-020-02506-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 12/03/2020] [Accepted: 12/16/2020] [Indexed: 01/02/2023]
Abstract
In cardiac muscle, the process of excitation-contraction coupling (ECC) describes the chain of events that links action potential induced myocyte membrane depolarization, surface membrane ion channel activation, triggering of Ca2+ induced Ca2+ release from the sarcoplasmic reticulum (SR) Ca2+ store to activation of the contractile machinery that is ultimately responsible for the pump function of the heart. Here we review similarities and differences of structural and functional attributes of ECC between atrial and ventricular tissue. We explore a novel "fire-diffuse-uptake-fire" paradigm of atrial ECC and Ca2+ release that assigns a novel role to the SR SERCA pump and involves a concerted "tandem" activation of the ryanodine receptor Ca2+ release channel by cytosolic and luminal Ca2+. We discuss the contribution of the inositol 1,4,5-trisphosphate (IP3) receptor Ca2+ release channel as an auxiliary pathway to Ca2+ signaling, and we review IP3 receptor-induced Ca2+ release involvement in beat-to-beat ECC, nuclear Ca2+ signaling, and arrhythmogenesis. Finally, we explore the topic of electromechanical and Ca2+ alternans and its ramifications for atrial arrhythmia.
Collapse
Affiliation(s)
- L A Blatter
- Department of Physiology & Biophysics, Rush University Medical Center, 1750 W. Harrison Street, Chicago, IL, 60612, USA.
| | - G Kanaporis
- Department of Physiology & Biophysics, Rush University Medical Center, 1750 W. Harrison Street, Chicago, IL, 60612, USA
| | - E Martinez-Hernandez
- Department of Physiology & Biophysics, Rush University Medical Center, 1750 W. Harrison Street, Chicago, IL, 60612, USA
| | - Y Oropeza-Almazan
- Department of Physiology & Biophysics, Rush University Medical Center, 1750 W. Harrison Street, Chicago, IL, 60612, USA
| | - K Banach
- Department of Internal Medicine/Cardiology, Rush University Medical Center, Chicago, IL, 60612, USA
| |
Collapse
|
18
|
Burton RAB, Terrar DA. Emerging Evidence for cAMP-calcium Cross Talk in Heart Atrial Nanodomains Where IP 3-Evoked Calcium Release Stimulates Adenylyl Cyclases. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2021; 4:25152564211008341. [PMID: 37366374 PMCID: PMC10243587 DOI: 10.1177/25152564211008341] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 03/01/2021] [Accepted: 03/07/2021] [Indexed: 06/28/2023]
Abstract
Calcium handling is vital to normal physiological function in the heart. Human atrial arrhythmias, eg. atrial fibrillation, are a major morbidity and mortality burden, yet major gaps remain in our understanding of how calcium signaling pathways function and interact. Inositol trisphosphate (IP3) is a calcium-mobilizing second messenger and its agonist-induced effects have been observed in many tissue types. In the atria IP3 receptors (IR3Rs) residing on junctional sarcoplasmic reticulum augment cellular calcium transients and, when over-stimulated, lead to arrhythmogenesis. Recent studies have demonstrated that the predominant pathway for IP3 actions in atrial myocytes depends on stimulation of calcium-dependent forms of adenylyl cyclase (AC8 and AC1) by IP3-evoked calcium release from the sarcoplasmic reticulum. AC8 shows co-localisation with IP3Rs and AC1 appears to be nearby. These observations support crosstalk between calcium and cAMP pathways in nanodomains in atria. Similar mechanisms also appear to operate in the pacemaker region of the sinoatrial node. Here we discuss these significant advances in our understanding of atrial physiology and pathology, together with implications for the identification of potential novel targets and modulators for the treatment of atrial arrhythmias.
Collapse
Affiliation(s)
| | - Derek A. Terrar
- Department of Pharmacology, University of Oxford, Oxford, UK
| |
Collapse
|
19
|
Qi XY, Vahdati Hassani F, Hoffmann D, Xiao J, Xiong F, Villeneuve LR, Ljubojevic-Holzer S, Kamler M, Abu-Taha I, Heijman J, Bers DM, Dobrev D, Nattel S. Inositol Trisphosphate Receptors and Nuclear Calcium in Atrial Fibrillation. Circ Res 2020; 128:619-635. [PMID: 33375812 DOI: 10.1161/circresaha.120.317768] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
RATIONALE The mechanisms underlying atrial fibrillation (AF), the most common clinical arrhythmia, are poorly understood. Nucleoplasmic Ca2+ regulates gene expression, but the nature and significance of nuclear Ca2+-changes in AF are largely unknown. OBJECTIVE To elucidate mechanisms by which AF alters atrial-cardiomyocyte nuclear Ca2+ ([Ca2+]Nuc) and CaMKII (Ca2+/calmodulin-dependent protein kinase-II)-related signaling. METHODS AND RESULTS Atrial cardiomyocytes were isolated from control and AF dogs (kept in AF by atrial tachypacing [600 bpm × 1 week]). [Ca2+]Nuc and cytosolic [Ca2+] ([Ca2+]Cyto) were recorded via confocal microscopy. Diastolic [Ca2+]Nuc was greater than [Ca2+]Cyto under control conditions, while resting [Ca2+]Nuc was similar to [Ca2+]Cyto; both diastolic and resting [Ca2+]Nuc increased with AF. IP3R (Inositol-trisphosphate receptor) stimulation produced larger [Ca2+]Nuc increases in AF versus control cardiomyocytes, and IP3R-blockade suppressed the AF-related [Ca2+]Nuc differences. AF upregulated nuclear protein expression of IP3R1 (IP3R-type 1) and of phosphorylated CaMKII (immunohistochemistry and immunoblot) while decreasing the nuclear/cytosolic expression ratio for HDAC4 (histone deacetylase type-4). Isolated atrial cardiomyocytes tachypaced at 3 Hz for 24 hours mimicked AF-type [Ca2+]Nuc changes and L-type calcium current decreases versus 1-Hz-paced cardiomyocytes; these changes were prevented by IP3R knockdown with short-interfering RNA directed against IP3R1. Nuclear/cytosolic HDAC4 expression ratio was decreased by 3-Hz pacing, while nuclear CaMKII phosphorylation was increased. Either CaMKII-inhibition (by autocamtide-2-related peptide) or IP3R-knockdown prevented the CaMKII-hyperphosphorylation and nuclear-to-cytosolic HDAC4 shift caused by 3-Hz pacing. In human atrial cardiomyocytes from AF patients, nuclear IP3R1-expression was significantly increased, with decreased nuclear/nonnuclear HDAC4 ratio. MicroRNA-26a was predicted to target ITPR1 (confirmed by luciferase assay) and was downregulated in AF atrial cardiomyocytes; microRNA-26a silencing reproduced AF-induced IP3R1 upregulation and nuclear diastolic Ca2+-loading. CONCLUSIONS AF increases atrial-cardiomyocyte nucleoplasmic [Ca2+] by IP3R1-upregulation involving miR-26a, leading to enhanced IP3R1-CaMKII-HDAC4 signaling and L-type calcium current downregulation. Graphic Abstract: A graphic abstract is available for this article.
Collapse
Affiliation(s)
- Xiao-Yan Qi
- Medicine, Montreal Heart Institute, Université de Montréal, Canada (X.-Y.Q., F.V.H., J.X., F.X., L.R.V., D.D., S.N.)
| | - Faezeh Vahdati Hassani
- Medicine, Montreal Heart Institute, Université de Montréal, Canada (X.-Y.Q., F.V.H., J.X., F.X., L.R.V., D.D., S.N.)
| | - Dennis Hoffmann
- Institute of Pharmacology, West German Heart and Vascular Center, Medical Faculty, University Duisburg-Essen, Germany (D.H., I.A.-T., J.H., D.D., S.N.)
| | - Jiening Xiao
- Medicine, Montreal Heart Institute, Université de Montréal, Canada (X.-Y.Q., F.V.H., J.X., F.X., L.R.V., D.D., S.N.)
| | - Feng Xiong
- Medicine, Montreal Heart Institute, Université de Montréal, Canada (X.-Y.Q., F.V.H., J.X., F.X., L.R.V., D.D., S.N.)
| | - Louis R Villeneuve
- Medicine, Montreal Heart Institute, Université de Montréal, Canada (X.-Y.Q., F.V.H., J.X., F.X., L.R.V., D.D., S.N.)
| | | | - Markus Kamler
- Departments of Thoracic and Cardiovascular Surgery Huttrop (M.K.)
| | - Issam Abu-Taha
- Institute of Pharmacology, West German Heart and Vascular Center, Medical Faculty, University Duisburg-Essen, Germany (D.H., I.A.-T., J.H., D.D., S.N.)
| | - Jordi Heijman
- Institute of Pharmacology, West German Heart and Vascular Center, Medical Faculty, University Duisburg-Essen, Germany (D.H., I.A.-T., J.H., D.D., S.N.).,Cardiology, Cardiovascular Research Institute Maastricht, Faculty of Health, Medicine, and Life Sciences, Maastricht University, the Netherlands (J.H.)
| | - Donald M Bers
- Physiology, University of California, Davis (S.L.-H., D.M.B.)
| | - Dobromir Dobrev
- Medicine, Montreal Heart Institute, Université de Montréal, Canada (X.-Y.Q., F.V.H., J.X., F.X., L.R.V., D.D., S.N.).,Institute of Pharmacology, West German Heart and Vascular Center, Medical Faculty, University Duisburg-Essen, Germany (D.H., I.A.-T., J.H., D.D., S.N.)
| | - Stanley Nattel
- Medicine, Montreal Heart Institute, Université de Montréal, Canada (X.-Y.Q., F.V.H., J.X., F.X., L.R.V., D.D., S.N.).,Institute of Pharmacology, West German Heart and Vascular Center, Medical Faculty, University Duisburg-Essen, Germany (D.H., I.A.-T., J.H., D.D., S.N.).,Pharmacology, McGill University Montreal, Canada (S.N.).,IHU LIRYC, Bordeaux, France (S.N.)
| |
Collapse
|
20
|
Minimal contribution of IP 3R2 in cardiac differentiation and derived ventricular-like myocytes from human embryonic stem cells. Acta Pharmacol Sin 2020; 41:1576-1586. [PMID: 33037404 DOI: 10.1038/s41401-020-00528-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 09/03/2020] [Indexed: 02/06/2023] Open
Abstract
Type 2 inositol 1,4,5-trisphosphate receptor (IP3R2) regulates the intracellular Ca2+ release from endoplasmic reticulum in human embryonic stem cells (hESCs), cardiovascular progenitor cells (CVPCs), and mammalian cardiomyocytes. However, the role of IP3R2 in human cardiac development is unknown and its function in mammalian cardiomyocytes is controversial. hESC-derived cardiomyocytes have unique merits in disease modeling, cell therapy, and drug screening. Therefore, understanding the role of IP3R2 in the generation and function of human cardiomyocytes would be valuable for the application of hESC-derived cardiomyocytes. In the current study, we investigated the role of IP3R2 in the differentiation of hESCs to cardiomyocytes and in the hESC-derived cardiomyocytes. By using IP3R2 knockout (IP3R2KO) hESCs, we showed that IP3R2KO did not affect the self-renewal of hESCs as well as the differentiation ability of hESCs into CVPCs and cardiomyocytes. Furthermore, we demonstrated the ventricular-like myocyte characteristics of hESC-derived cardiomyocytes. Under the α1-adrenergic stimulation by phenylephrine (10 μmol/L), the amplitude and maximum rate of depolarization of action potential (AP) were slightly affected in the IP3R2KO hESC-derived cardiomyocytes at differentiation day 90, whereas the other parameters of APs and the Ca2+ transients did not show significant changes compared with these in the wide-type ones. These results demonstrate that IP3R2 has minimal contribution to the differentiation and function of human cardiomyocytes derived from hESCs, thus provide the new knowledge to the function of IP3R2 in the generation of human cardiac lineage cells and in the early cardiomyocytes.
Collapse
|
21
|
Ca 2+ Release via IP 3 Receptors Shapes the Cardiac Ca 2+ Transient for Hypertrophic Signaling. Biophys J 2020; 119:1178-1192. [PMID: 32871099 DOI: 10.1016/j.bpj.2020.08.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 06/16/2020] [Accepted: 08/04/2020] [Indexed: 12/27/2022] Open
Abstract
Calcium (Ca2+) plays a central role in mediating both contractile function and hypertrophic signaling in ventricular cardiomyocytes. L-type Ca2+ channels trigger release of Ca2+ from ryanodine receptors for cellular contraction, whereas signaling downstream of G-protein-coupled receptors stimulates Ca2+ release via inositol 1,4,5-trisphosphate receptors (IP3Rs), engaging hypertrophic signaling pathways. Modulation of the amplitude, duration, and duty cycle of the cytosolic Ca2+ contraction signal and spatial localization have all been proposed to encode this hypertrophic signal. Given current knowledge of IP3Rs, we develop a model describing the effect of functional interaction (cross talk) between ryanodine receptor and IP3R channels on the Ca2+ transient and examine the sensitivity of the Ca2+ transient shape to properties of IP3R activation. A key result of our study is that IP3R activation increases Ca2+ transient duration for a broad range of IP3R properties, but the effect of IP3R activation on Ca2+ transient amplitude is dependent on IP3 concentration. Furthermore we demonstrate that IP3-mediated Ca2+ release in the cytosol increases the duty cycle of the Ca2+ transient, the fraction of the cycle for which [Ca2+] is elevated, across a broad range of parameter values and IP3 concentrations. When coupled to a model of downstream transcription factor (NFAT) activation, we demonstrate that there is a high correspondence between the Ca2+ transient duty cycle and the proportion of activated NFAT in the nucleus. These findings suggest increased cytosolic Ca2+ duty cycle as a plausible mechanism for IP3-dependent hypertrophic signaling via Ca2+-sensitive transcription factors such as NFAT in ventricular cardiomyocytes.
Collapse
|
22
|
Mijares A, Espinosa R, Adams J, Lopez JR. Increases in [IP3]i aggravates diastolic [Ca2+] and contractile dysfunction in Chagas' human cardiomyocytes. PLoS Negl Trop Dis 2020; 14:e0008162. [PMID: 32275663 PMCID: PMC7176279 DOI: 10.1371/journal.pntd.0008162] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 04/22/2020] [Accepted: 02/21/2020] [Indexed: 11/18/2022] Open
Abstract
Chagas cardiomyopathy is the most severe manifestation of human Chagas disease and represents the major cause of morbidity and mortality in Latin America. We previously demonstrated diastolic Ca2+ alterations in cardiomyocytes isolated from Chagas' patients to different degrees of cardiac dysfunction. In addition, we have found a significant elevation of diastolic [Na+]d in Chagas' cardiomyocytes (FCII>FCI) that was greater than control. Exposure of cardiomyocytes to agents that enhance inositol 1,4,5 trisphosphate (IP3) generation or concentration like endothelin (ET-1) or bradykinin (BK), or membrane-permeant myoinositol 1,4,5-trisphosphate hexakis(butyryloxy-methyl) esters (IP3BM) caused an elevation in diastolic [Ca2+] ([Ca2+]d) that was always greater in cardiomyocytes from Chagas' than non- Chagas' subjects, and the magnitude of the [Ca2+]d elevation in Chagas' cardiomyocytes was related to the degree of cardiac dysfunction. Incubation with xestospongin-C (Xest-C), a membrane-permeable selective blocker of the IP3 receptors (IP3Rs), significantly reduced [Ca2+]d in Chagas' cardiomyocytes but did not have a significant effect on non-Chagas' cells. The effects of ET-1, BK, and IP3BM on [Ca2+]d were not modified by the removal of extracellular [Ca2+]e. Furthermore, cardiomyocytes from Chagas' patients had a significant decrease in the sarcoplasmic reticulum (SR) Ca2+content compared to control (Control>FCI>FCII), a higher intracellular IP3 concentration ([IP3]i) and markedly depressed contractile properties compared to control cardiomyocytes. These results provide additional and convincing support about the implications of IP3 in the pathogenesis of Chagas cardiomyopathy in patients at different stages of chronic infection. Additionally, these findings open the door for novel therapeutic strategies oriented to improve cardiac function and quality of life of individuals suffering from chronic Chagas cardiomyopathy (CC).
Collapse
Affiliation(s)
- Alfredo Mijares
- Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela
| | - Raúl Espinosa
- Departamento de Cardiología, Hospital Miguel Pérez Carreño, Instituto venezolano de los Seguros Sociales, Caracas, Venezuela
| | - José Adams
- Division of Neonatology, Mount Sinai, Medical Center, Miami, FL, United States of America
| | - José R. Lopez
- Department of Research, Mount Sinai, Medical Center, Miami, FL, United States of America
| |
Collapse
|
23
|
Gilbert G, Demydenko K, Dries E, Puertas RD, Jin X, Sipido K, Roderick HL. Calcium Signaling in Cardiomyocyte Function. Cold Spring Harb Perspect Biol 2020; 12:cshperspect.a035428. [PMID: 31308143 DOI: 10.1101/cshperspect.a035428] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Rhythmic increases in intracellular Ca2+ concentration underlie the contractile function of the heart. These heart muscle-wide changes in intracellular Ca2+ are induced and coordinated by electrical depolarization of the cardiomyocyte sarcolemma by the action potential. Originating at the sinoatrial node, conduction of this electrical signal throughout the heart ensures synchronization of individual myocytes into an effective cardiac pump. Ca2+ signaling pathways also regulate gene expression and cardiomyocyte growth during development and in pathology. These fundamental roles of Ca2+ in the heart are illustrated by the prevalence of altered Ca2+ homeostasis in cardiovascular diseases. Indeed, heart failure (an inability of the heart to support hemodynamic needs), rhythmic disturbances, and inappropriate cardiac growth all share an involvement of altered Ca2+ handling. The prevalence of these pathologies, contributing to a third of all deaths in the developed world as well as to substantial morbidity makes understanding the mechanisms of Ca2+ handling and dysregulation in cardiomyocytes of great importance.
Collapse
Affiliation(s)
- Guillaume Gilbert
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, BE3000 Leuven, Belgium
| | - Kateryna Demydenko
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, BE3000 Leuven, Belgium
| | - Eef Dries
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, BE3000 Leuven, Belgium
| | - Rosa Doñate Puertas
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, BE3000 Leuven, Belgium
| | - Xin Jin
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, BE3000 Leuven, Belgium
| | - Karin Sipido
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, BE3000 Leuven, Belgium
| | - H Llewelyn Roderick
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, BE3000 Leuven, Belgium
| |
Collapse
|
24
|
Zhou X, Park KH, Yamazaki D, Lin PH, Nishi M, Ma Z, Qiu L, Murayama T, Zou X, Takeshima H, Zhou J, Ma J. TRIC-A Channel Maintains Store Calcium Handling by Interacting With Type 2 Ryanodine Receptor in Cardiac Muscle. Circ Res 2019; 126:417-435. [PMID: 31805819 DOI: 10.1161/circresaha.119.316241] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
RATIONALE Trimeric intracellular cation (TRIC)-A and B are distributed to endoplasmic reticulum/sarcoplasmic reticulum intracellular Ca2+ stores. The crystal structure of TRIC has been determined, confirming the homotrimeric structure of a potassium channel. While the pore architectures of TRIC-A and TRIC-B are conserved, the carboxyl-terminal tail (CTT) domains of TRIC-A and TRIC-B are different from each other. Aside from its recognized role as a counterion channel that participates in excitation-contraction coupling of striated muscles, the physiological function of TRIC-A in heart physiology and disease has remained largely unexplored. OBJECTIVE In cardiomyocytes, spontaneous Ca2+ waves, triggered by store overload-induced Ca2+ release mediated by the RyR2 (type 2 ryanodine receptor), develop extrasystolic contractions often associated with arrhythmic events. Here, we test the hypothesis that TRIC-A is a physiological component of RyR2-mediated Ca2+ release machinery that directly modulates store overload-induced Ca2+ release activity via CTT. METHODS AND RESULTS We show that cardiomyocytes derived from the TRIC-A-/- (TRIC-A knockout) mice display dysregulated Ca2+ movement across sarcoplasmic reticulum. Biochemical studies demonstrate a direct interaction between CTT-A and RyR2. Modeling and docking studies reveal potential sites on RyR2 that show differential interactions with CTT-A and CTT-B. In HEK293 (human embryonic kidney) cells with stable expression of RyR2, transient expression of TRIC-A, but not TRIC-B, leads to apparent suppression of spontaneous Ca2+ oscillations. Ca2+ measurements using the cytosolic indicator Fura-2 and the endoplasmic reticulum luminal store indicator D1ER suggest that TRIC-A enhances Ca2+ leak across the endoplasmic reticulum by directly targeting RyR2 to modulate store overload-induced Ca2+ release. Moreover, synthetic CTT-A peptide facilitates RyR2 activity in lipid bilayer reconstitution system, enhances Ca2+ sparks in permeabilized TRIC-A-/- cardiomyocytes, and induces intracellular Ca2+ release after microinjection into isolated cardiomyocytes, whereas such effects were not observed with the CTT-B peptide. In response to isoproterenol stimulation, the TRIC-A-/- mice display irregular ECG and develop more fibrosis than the WT (wild type) littermates. CONCLUSIONS In addition to the ion-conducting function, TRIC-A functions as an accessory protein of RyR2 to modulate sarcoplasmic reticulum Ca2+ handling in cardiac muscle.
Collapse
Affiliation(s)
- Xinyu Zhou
- From the Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University, Columbus (X. Zhou, K.H.P., P.-h.L., J.M.)
| | - Ki Ho Park
- From the Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University, Columbus (X. Zhou, K.H.P., P.-h.L., J.M.)
| | - Daiju Yamazaki
- Department of Biological Chemistry, Kyoto University Graduate School of Pharmaceutical Sciences, Japan (D.Y., M.N., H.T.)
| | - Pei-Hui Lin
- From the Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University, Columbus (X. Zhou, K.H.P., P.-h.L., J.M.)
| | - Miyuki Nishi
- Department of Biological Chemistry, Kyoto University Graduate School of Pharmaceutical Sciences, Japan (D.Y., M.N., H.T.)
| | - Zhiwei Ma
- Department of Physics and Astronomy, Dalton Cardiovascular Research Center (Z.M., L.Q., X. Zou), University of Missouri, Columbia.,Department of Biochemistry (Z.M., L.Q., X. Zou), University of Missouri, Columbia
| | - Liming Qiu
- Department of Physics and Astronomy, Dalton Cardiovascular Research Center (Z.M., L.Q., X. Zou), University of Missouri, Columbia.,Department of Biochemistry (Z.M., L.Q., X. Zou), University of Missouri, Columbia
| | - Takashi Murayama
- Department of Pharmacology, Juntendo University School of Medicine, Tokyo, Japan (T.M.)
| | - Xiaoqin Zou
- Department of Physics and Astronomy, Dalton Cardiovascular Research Center (Z.M., L.Q., X. Zou), University of Missouri, Columbia.,Department of Biochemistry (Z.M., L.Q., X. Zou), University of Missouri, Columbia
| | - Hiroshi Takeshima
- Department of Biological Chemistry, Kyoto University Graduate School of Pharmaceutical Sciences, Japan (D.Y., M.N., H.T.)
| | - Jingsong Zhou
- Department of Kinesiology, College of Nursing and Health Innovation, University of Texas at Arlington (J.Z.)
| | - Jianjie Ma
- From the Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University, Columbus (X. Zhou, K.H.P., P.-h.L., J.M.)
| |
Collapse
|
25
|
Abstract
The aim of this chapter is to discuss evidence concerning the many roles of calcium ions, Ca2+, in cell signaling pathways that control heart function. Before considering details of these signaling pathways, the control of contraction in ventricular muscle by Ca2+ transients accompanying cardiac action potentials is first summarized, together with a discussion of how myocytes from the atrial and pacemaker regions of the heart diverge from this basic scheme. Cell signaling pathways regulate the size and timing of the Ca2+ transients in the different heart regions to influence function. The simplest Ca2+ signaling elements involve enzymes that are regulated by cytosolic Ca2+. Particularly important examples to be discussed are those that are stimulated by Ca2+, including Ca2+-calmodulin-dependent kinase (CaMKII), Ca2+ stimulated adenylyl cyclases, Ca2+ stimulated phosphatase and NO synthases. Another major aspect of Ca2+ signaling in the heart concerns actions of the Ca2+ mobilizing agents, inositol trisphosphate (IP3), cADP-ribose (cADPR) and nicotinic acid adenine dinucleotide phosphate, (NAADP). Evidence concerning roles of these Ca2+ mobilizing agents in different regions of the heart is discussed in detail. The focus of the review will be on short term regulation of Ca2+ transients and contractile function, although it is recognized that Ca2+ regulation of gene expression has important long term functional consequences which will also be briefly discussed.
Collapse
|
26
|
Mayourian J, Ceholski DK, Gonzalez DM, Cashman TJ, Sahoo S, Hajjar RJ, Costa KD. Physiologic, Pathologic, and Therapeutic Paracrine Modulation of Cardiac Excitation-Contraction Coupling. Circ Res 2019; 122:167-183. [PMID: 29301848 DOI: 10.1161/circresaha.117.311589] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cardiac excitation-contraction coupling (ECC) is the orchestrated process of initial myocyte electrical excitation, which leads to calcium entry, intracellular trafficking, and subsequent sarcomere shortening and myofibrillar contraction. Neurohumoral β-adrenergic signaling is a well-established mediator of ECC; other signaling mechanisms, such as paracrine signaling, have also demonstrated significant impact on ECC but are less well understood. For example, resident heart endothelial cells are well-known physiological paracrine modulators of cardiac myocyte ECC mainly via NO and endothelin-1. Moreover, recent studies have demonstrated other resident noncardiomyocyte heart cells (eg, physiological fibroblasts and pathological myofibroblasts), and even experimental cardiotherapeutic cells (eg, mesenchymal stem cells) are also capable of altering cardiomyocyte ECC through paracrine mechanisms. In this review, we first focus on the paracrine-mediated effects of resident and therapeutic noncardiomyocytes on cardiomyocyte hypertrophy, electrophysiology, and calcium handling, each of which can modulate ECC, and then discuss the current knowledge about key paracrine factors and their underlying mechanisms of action. Next, we provide a case example demonstrating the promise of tissue-engineering approaches to study paracrine effects on tissue-level contractility. More specifically, we present new functional and molecular data on the effects of human adult cardiac fibroblast conditioned media on human engineered cardiac tissue contractility and ion channel gene expression that generally agrees with previous murine studies but also suggests possible species-specific differences. By contrast, paracrine secretions by human dermal fibroblasts had no discernible effect on human engineered cardiac tissue contractile function and gene expression. Finally, we discuss systems biology approaches to help identify key stem cell paracrine mediators of ECC and their associated mechanistic pathways. Such integration of tissue-engineering and systems biology methods shows promise to reveal novel insights into paracrine mediators of ECC and their underlying mechanisms of action, ultimately leading to improved cell-based therapies for patients with heart disease.
Collapse
Affiliation(s)
- Joshua Mayourian
- From the Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Delaine K Ceholski
- From the Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY
| | - David M Gonzalez
- From the Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Timothy J Cashman
- From the Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Susmita Sahoo
- From the Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Roger J Hajjar
- From the Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Kevin D Costa
- From the Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY.
| |
Collapse
|
27
|
Fender AC, Wakili R, Dobrev D. Straight to the heart: Pleiotropic antiarrhythmic actions of oral anticoagulants. Pharmacol Res 2019; 145:104257. [PMID: 31054953 DOI: 10.1016/j.phrs.2019.104257] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 04/30/2019] [Accepted: 05/01/2019] [Indexed: 02/06/2023]
Abstract
Mechanistic understanding of atrial fibrillation (AF) pathophysiology and the complex bidirectional relationship with thromboembolic risk remains limited. Oral anticoagulation is a mainstay of AF management. An emerging concept is that anticoagulants may themselves have potential pleiotropic disease-modifying effects. We here review the available evidence for hemostasis-independent actions of the oral anticoagulants on electrical and structural remodeling, and the inflammatory component of the vulnerable substrate.
Collapse
Affiliation(s)
- Anke C Fender
- Institute of Pharmacology, West-German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen, Germany.
| | - Reza Wakili
- Clinic for Cardiology and Angiology, West-German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen, Germany
| | - Dobromir Dobrev
- Institute of Pharmacology, West-German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen, Germany
| |
Collapse
|
28
|
Structural and Mechanistic Bases of Nuclear Calcium Signaling in Human Pluripotent Stem Cell-Derived Ventricular Cardiomyocytes. Stem Cells Int 2019; 2019:8765752. [PMID: 31065282 PMCID: PMC6466844 DOI: 10.1155/2019/8765752] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 12/10/2018] [Accepted: 01/08/2019] [Indexed: 11/23/2022] Open
Abstract
The loss of nonregenerative, terminally differentiated cardiomyocytes (CMs) due to aging or diseases is generally considered irreversible. Human pluripotent stem cells (hPSCs) can self-renew while maintaining their pluripotency to differentiate into all cell types, including ventricular (V) cardiomyocytes (CMs), to provide a potential unlimited ex vivo source of CMs for heart disease modeling, drug/cardiotoxicity screening, and cell-based therapies. In the human heart, cytosolic Ca2+ signals are well characterized but the contribution of nuclear Ca2+ is essentially unexplored. The present study investigated nuclear Ca2+ signaling in hPSC-VCMs. Calcium transient or sparks in hPSC-VCMs were measured by line scanning using a spinning disc confocal microscope. We observed that nuclear Ca2+, which stems from unitary sparks due to the diffusion of cytosolic Ca2+ that are mediated by RyRs on the nuclear reticulum, is functional. Parvalbumin- (PV-) mediated Ca2+ buffering successfully manipulated Ca2+ transient and stimuli-induced apoptosis in hPSC-VCMs. We also investigated the effect of Ca2+ on gene transcription in hPSC-VCMs, and the involvement of nuclear factor of activated T-cell (NFAT) pathway was identified. The overexpression of Ca2+-sensitive, nuclear localized Ca2+/calmodulin-dependent protein kinase II δB (CaMKIIδB) induced cardiac hypertrophy through nuclear Ca2+/CaMKIIδB/HDAC4/MEF2 pathway. These findings provide insights into nuclear Ca2+ signal in hPSC-VCMs, which may lead to novel strategies for maturation as well as improved systems for disease modeling, drug discovery, and cell-based therapies.
Collapse
|
29
|
Viola HM, Hool LC. Impaired calcium handling and mitochondrial metabolic dysfunction as early markers of hypertrophic cardiomyopathy. Arch Biochem Biophys 2019; 665:166-174. [PMID: 30885674 DOI: 10.1016/j.abb.2019.03.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 03/08/2019] [Accepted: 03/11/2019] [Indexed: 02/07/2023]
Abstract
Hypertrophic cardiomyopathy (HCM) is a primary myocardial disorder, characterised by myocyte remodeling, disorganisation of sarcomeric proteins, impaired energy metabolism and altered cardiac contractility. Gene mutations encoding cardiac contractile proteins account for 60% of HCM aetiology. Current drug therapy including L-type calcium channel antagonists, are used to manage symptoms in patients with overt HCM, but no treatment exists that can reverse or prevent the cardiomyopathy. Design of effective drug therapy will require a clear understanding of the early pathophysiological mechanisms of the disease. Numerous studies have investigated specific aspects of HCM pathophysiology. This review brings these findings together, in order to develop a holistic understanding of the early pathophysiological mechanisms of the disease. We focus on gene mutations in cardiac myosin binding protein-C, β-cardiac myosin heavy chain, cardiac troponin I, and cardiac troponin T, that comprise the majority of all HCM sarcomeric gene mutations. We find that although some similarities exist, each mutation leads to mutation-specific alterations in calcium handling, myofilament calcium sensitivity and mitochondrial metabolic function. This may contribute to the observed clinical phenotypic variability in sarcomeric-related HCM. An understanding of early mutation-specific mechanisms of the disease may provide useful markers of disease progression, and inform therapeutic design.
Collapse
Affiliation(s)
- Helena M Viola
- School of Human Sciences (Physiology), The University of Western Australia, Crawley, WA, Australia
| | - Livia C Hool
- School of Human Sciences (Physiology), The University of Western Australia, Crawley, WA, Australia; Victor Chang Cardiac Research Institute, Sydney, NSW, Australia.
| |
Collapse
|
30
|
Ronchi C, Badone B, Bernardi J, Zaza A. Action Potential Prolongation, β-Adrenergic Stimulation, and Angiotensin II as Co-factors in Sarcoplasmic Reticulum Instability. Front Physiol 2019; 9:1893. [PMID: 30687114 PMCID: PMC6333690 DOI: 10.3389/fphys.2018.01893] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 12/14/2018] [Indexed: 12/26/2022] Open
Abstract
Introduction: Increases in action potential duration (APD), genetic or acquired, and arrhythmias are often associated; nonetheless, the relationship between the two phenomena is inconstant, suggesting coexisting factors. β-adrenergic activation increases sarcoplasmic reticulum (SR) Ca2+-content; angiotensin II (ATII) may increase cytosolic Ca2+ and ROS production, all actions stimulating RyRs opening. Here we test how APD interacts with β-adrenergic and AT-receptor stimulation in facilitating spontaneous Ca2+ release events (SCR). Methods: Under “action potential (AP) clamp”, guinea-pig cardiomyocytes (CMs) were driven with long (200 ms), normal (150 ms), and short (100 ms) AP waveforms at a CL of 500 ms; in a subset of CMs, all the 3 waveforms could be tested within the same cell. SCR were detected as inward current transients (ITI) following repolarization; ITI incidence and repetition within the same cycle were measured under increasing isoprenaline concentration ([ISO]) alone, or plus 100 nM ATII (30 min incubation+superfusion). Results: ITI incidence and repetition increased with [ISO]; at longer APs the [ISO]-response curve was shifted upward and ITI coupling interval was reduced. ATII increased ITI incidence more at low [ISO] and under normal (as compared to long) APs. Efficacy of AP shortening in suppressing ITI decreased in ATII-treated myocytes and at higher [ISO]. Conclusions: AP prolongation sensitized the SR to the destabilizing actions of ISO and ATII. Summation of ISO, ATII and AP duration effects had a “saturating” effect on SCR incidence, thus suggesting convergence on a common factor (RyRs stability) “reset” by the occurrence of spontaneous Ca2+ release events.
Collapse
Affiliation(s)
- Carlotta Ronchi
- Laboratory of Cardiac Cellular Physiology, Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
| | - Beatrice Badone
- Laboratory of Cardiac Cellular Physiology, Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
| | - Joyce Bernardi
- Laboratory of Cardiac Cellular Physiology, Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
| | - Antonio Zaza
- Laboratory of Cardiac Cellular Physiology, Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
| |
Collapse
|
31
|
Hegyi B, Bers DM, Bossuyt J. CaMKII signaling in heart diseases: Emerging role in diabetic cardiomyopathy. J Mol Cell Cardiol 2019; 127:246-259. [PMID: 30633874 DOI: 10.1016/j.yjmcc.2019.01.001] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 01/04/2019] [Indexed: 02/07/2023]
Abstract
Calcium/calmodulin-dependent protein kinase II (CaMKII) is upregulated in diabetes and significantly contributes to cardiac remodeling with increased risk of cardiac arrhythmias. Diabetes is frequently associated with atrial fibrillation, coronary artery disease, and heart failure, which may further enhance CaMKII. Activation of CaMKII occurs downstream of neurohormonal stimulation (e.g. via G-protein coupled receptors) and involve various posttranslational modifications including autophosphorylation, oxidation, S-nitrosylation and O-GlcNAcylation. CaMKII signaling regulates diverse cellular processes in a spatiotemporal manner including excitation-contraction and excitation-transcription coupling, mechanics and energetics in cardiac myocytes. Chronic activation of CaMKII results in cellular remodeling and ultimately arrhythmogenic alterations in Ca2+ handling, ion channels, cell-to-cell coupling and metabolism. This review addresses the detrimental effects of the upregulated CaMKII signaling to enhance the arrhythmogenic substrate and trigger mechanisms in the heart. We also briefly summarize preclinical studies using kinase inhibitors and genetically modified mice targeting CaMKII in diabetes. The mechanistic understanding of CaMKII signaling, cardiac remodeling and arrhythmia mechanisms may reveal new therapeutic targets and ultimately better treatment in diabetes and heart disease in general.
Collapse
Affiliation(s)
- Bence Hegyi
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - Donald M Bers
- Department of Pharmacology, University of California Davis, Davis, CA, USA.
| | - Julie Bossuyt
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| |
Collapse
|
32
|
Singh N, Adlakha N. Three dimensional coupled reaction–diffusion modeling of calcium and inositol 1,4,5-trisphosphate dynamics in cardiomyocytes. RSC Adv 2019; 9:42459-42469. [PMID: 35542883 PMCID: PMC9076935 DOI: 10.1039/c9ra06929a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Accepted: 11/28/2019] [Indexed: 11/30/2022] Open
Abstract
Nanoparticles have shown great promise in improving cancer treatment efficacy by changing the intracellular calcium level through activation of intracellular mechanisms. One of the mechanisms of the killing of the cancerous cell by a nanoparticle is through elevation of the intracellular calcium level. Evidence accumulated over the past decade indicates a pivotal role for the IP3 receptor mediated Ca2+ release in the regulation of the cytosolic and the nuclear Ca2+ signals. There have been various studies done suggesting the role of IP3 receptors (IP3R) and IP3 production and degradation in cardiomyocytes. In the present work, we have proposed a three-dimensional unsteady-state mathematical model to describe the mechanism of cardiomyocytes which focuses on evaluation of various parameters that affect these coupled dynamics and elevate the cytosolic calcium concentration which can be helpful to search for novel therapies to cure these malignancies by targeting the complex calcium signaling process in cardiomyocytes. Our study suggests that there are other factors involved in this signaling which can increase the calcium level, which can help in finding treatment for cancer. The cytosolic calcium level may be controlled by IP3 signaling, leak, source influx of calcium (σ) and maximum production of IP3 (VP). We believe that the proposed model suggests new insight into finding treatment for cancer in cardiomyocytes through elevation of the cytosolic Ca2+ concentration by various parameters like leak, σ, VP and especially by other complex cell signaling dynamics, namely IP3 dynamics. We propose a three-dimensional unsteady-state mathematical model to describe the mechanism of cardiomyocytes.![]()
Collapse
Affiliation(s)
- Nisha Singh
- Applied Mathematics and Humanities Department
- SVNIT
- Surat
- India
| | - Neeru Adlakha
- Applied Mathematics and Humanities Department
- SVNIT
- Surat
- India
| |
Collapse
|
33
|
Mechanism of interleukin-1 receptor antagonist protection against myocardial ischaemia/reperfusion-induced injury. Arch Cardiovasc Dis 2018; 111:545-554. [DOI: 10.1016/j.acvd.2017.12.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 12/05/2017] [Accepted: 12/06/2017] [Indexed: 12/15/2022]
|
34
|
Chen M, Xu D, Wu AZ, Kranias E, Lin SF, Chen PS, Chen Z. Phospholamban regulates nuclear Ca 2+ stores and inositol 1,4,5-trisphosphate mediated nuclear Ca 2+ cycling in cardiomyocytes. J Mol Cell Cardiol 2018; 123:185-197. [PMID: 30261161 DOI: 10.1016/j.yjmcc.2018.09.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 09/04/2018] [Accepted: 09/21/2018] [Indexed: 01/15/2023]
Abstract
AIMS Phospholamban (PLB) is the key regulator of the cardiac Ca2+ pump (SERCA2a)-mediated sarcoplasmic reticulum Ca2+ stores. We recently reported that PLB is highly concentrated in the nuclear envelope (NE) from where it can modulate perinuclear Ca2+ handling of the cardiomyocytes (CMs). Since inositol 1,4,5-trisphosphate (IP3) receptor (IP3R) mediates nuclear Ca2+ release, we examined whether the nuclear pool of PLB regulates IP3-induced nuclear Ca2+ handling. METHODS AND RESULTS Fluo-4 based confocal Ca2+ imaging was performed to measure Ca2+ dynamics across both nucleus and cytosol in saponin-permeabilized CMs isolated from wild-type (WT) or PLB-knockout (PLB-KO) mice. At diastolic intracellular Ca2+ ([Ca2+]i = 100 nM), the Fab fragment of the monoclonal PLB antibody (anti-PLB Fab) facilitated the formation and increased the length of spontaneous Ca2+ waves (SCWs) originating from the nuclear region in CMs from WT but not from PLB-KO mice. We next examined nuclear Ca2+ activities at basal condition and after sequential addition of IP3, anti-PLB Fab, and the IP3R inhibitor 2-aminoethoxydiphenyl borate (2-APB) at a series of [Ca2+]i. In WT mice, at 10 nM [Ca2+]i where ryanodine receptor (RyR2) based spontaneous Ca2+ sparks rarely occurred, IP3 increased fluorescence amplitude (F/F0) of overall nuclear region to 1.19 ± 0.02. Subsequent addition of anti-PLB Fab significantly decreased F/F0 to 1.09 ± 0.02. At 50 nM [Ca2+]i, anti-PLB Fab not only decreased the overall nuclear F/F0 previously elevated by IP3, but also increased the amplitude and duration of spark-like nuclear Ca2+ release events. These nuclear Ca2+ releases were blocked by 2-APB. At 100 nM [Ca2+]i, IP3 induced short SCWs originating from nucleus. Anti-PLB Fab transformed those short waves into long SCWs with propagation from the nucleus into the cytosol. In contrast, neither nuclear nor cytosolic Ca2+ dynamics was affected by anti-PLB Fab in CMs from PLB-KO mice in all these conditions. Furthermore, in WT CMs pretreated with RyR2 blocker tetracaine, IP3 and anti-PLB Fab still increased the magnitude of nuclear Ca2+ release but failed to regenerate SCWs. Finally, anti-PLB Fab increased low Ca2+ affinity mag-fluo 4 fluorescence intensity in the lumen of NE of nuclei isolated from WT but not in PLB-KO mice. CONCLUSION PLB regulates nuclear Ca2+ handling. By increasing Ca2+ uptake into lumen of the NE and perhaps other perinuclear membranes, the acute reversal of PLB inhibition decreases global Ca2+ concentration at rest in the nucleoplasm, and increases Ca2+ release into the nucleus, through mechanisms involving IP3R and RyR2 in the vicinity.
Collapse
Affiliation(s)
- Mu Chen
- Krannert Institute of Cardiology, Indiana University, Indianapolis, IN, USA; Department of Cardiology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Dongzhu Xu
- Krannert Institute of Cardiology, Indiana University, Indianapolis, IN, USA; Cardiovascular Division, Institute of Clinical Medicine, Faculty of Medicine, University of Tsukuba, Japan
| | - Adonis Z Wu
- Krannert Institute of Cardiology, Indiana University, Indianapolis, IN, USA
| | - Evangelia Kranias
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Shien-Fong Lin
- Krannert Institute of Cardiology, Indiana University, Indianapolis, IN, USA; Institute of Biomedical Engineering, College of Electrical and Computer Engineering, National Chiao Tung University, Hsin-Chu, Taiwan
| | - Peng-Sheng Chen
- Krannert Institute of Cardiology, Indiana University, Indianapolis, IN, USA
| | - Zhenhui Chen
- Krannert Institute of Cardiology, Indiana University, Indianapolis, IN, USA.
| |
Collapse
|
35
|
Blanch i Salvador J, Egger M. Obstruction of ventricular Ca 2+ -dependent arrhythmogenicity by inositol 1,4,5-trisphosphate-triggered sarcoplasmic reticulum Ca 2+ release. J Physiol 2018; 596:4323-4340. [PMID: 30004117 PMCID: PMC6138286 DOI: 10.1113/jp276319] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 07/06/2018] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Augmented inositol 1,4,5-trisphosphate (IP3 ) receptor (IP3 R2) expression has been linked to a variety of cardiac pathologies. Although cardiac IP3 R2 function has been in the focus of research for some time, a detailed understanding of its potential role in ventricular myocyte excitation-contraction coupling under pathophysiological conditions remains elusive. The present study focuses on mechanisms of IP3 R2-mediated sarcoplasmic reticulum (SR)-Ca2+ release in ventricular excitation-contraction coupling under IP3 R2-overexpressing conditions by studying intracellular Ca2+ events. We report that, upon IP3 R2 overexpression in ventricular myocytes, IP3 -induced Ca2+ release (IP3 ICR) modulates the SR-Ca2+ content via "eventless" SR-Ca2+ release, affecting the global SR-Ca2+ leak. Thus, IP3 R2 activation could act as a SR-Ca2+ gateway mechanism to escape ominous SR-Ca2+ overload. Our approach unmasks a so far unrecognized mechanism by which "eventless" IP3 ICR plays a protective role against ventricular Ca2+ -dependent arrhythmogenicity. ABSTRACT Augmented inositol 1,4,5-trisphosphate (IP3 ) receptor (IP3 R2) function has been linked to a variety of cardiac pathologies including cardiac arrhythmias. The functional role of IP3 -induced Ca2+ release (IP3 ICR) within ventricular excitation-contraction coupling (ECC) remains elusive. As part of pathophysiological cellular remodelling, IP3 R2s are overexpressed and have been repeatedly linked to enhanced Ca2+ -dependent arrhythmogenicity. In this study we test the hypothesis that an opposite scenario might be plausible in which IP3 ICR is part of an ECC protecting mechanism, resulting in a Ca2+ -dependent anti-arrhythmogenic response on the cellular scale. IP3 R2 activation was triggered via endothelin-1 or IP3 -salt application in single ventricular myocytes from a cardiac-specific IP3 R type 2 overexpressing mouse model. Upon IP3 R2 overexpression, IP3 R activation reduced Ca2+ -wave occurrence (46 vs. 21.72%; P < 0.001) while its block increased SR-Ca2+ content (∼29.4% 2-aminoethoxydiphenyl borate, ∼16.4% xestospongin C; P < 0.001), suggesting an active role of IP3 ICR in SR-Ca2+ content regulation and anti-arrhythmogenic function. Pharmacological separation of ryanodine receptor RyR2 and IP3 R2 functions and two-dimensional Ca2+ event analysis failed to identify local IP3 ICR events (Ca2+ puffs). SR-Ca2+ leak measurements revealed that under pathophysiological conditions, "eventless" SR-Ca2+ efflux via enhanced IP3 ICR maintains the SR-Ca2+ content below Ca2+ spark threshold, preventing aberrant SR-Ca2+ release and resulting in a protective mechanism against SR-Ca2+ overload and arrhythmias. Our results support a so far unrecognized modulatory mechanism in ventricular myocytes working in an anti-arrhythmogenic fashion.
Collapse
Affiliation(s)
| | - Marcel Egger
- Department of PhysiologyUniversity of BernBuehlplatz 5CH‐3012BernSwitzerland
| |
Collapse
|
36
|
Smyrnias I, Goodwin N, Wachten D, Skogestad J, Aronsen JM, Robinson EL, Demydenko K, Segonds-Pichon A, Oxley D, Sadayappan S, Sipido K, Bootman MD, Roderick HL. Contractile responses to endothelin-1 are regulated by PKC phosphorylation of cardiac myosin binding protein-C in rat ventricular myocytes. J Mol Cell Cardiol 2018; 117:1-18. [DOI: 10.1016/j.yjmcc.2018.02.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 02/02/2018] [Accepted: 02/16/2018] [Indexed: 01/07/2023]
|
37
|
Cellular mechanisms of metabolic syndrome-related atrial decompensation in a rat model of HFpEF. J Mol Cell Cardiol 2017; 115:10-19. [PMID: 29289652 DOI: 10.1016/j.yjmcc.2017.12.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 11/30/2017] [Accepted: 12/27/2017] [Indexed: 11/23/2022]
Abstract
Heart failure (HF) with preserved ejection fraction (HFpEF) is present in about 50% of HF patients. Atrial remodeling is common in HFpEF and associated with increased mortality. We postulate that atrial remodeling is associated with atrial dysfunction in vivo related to alterations in cardiomyocyte Calcium (Ca) signaling and remodeling. We examined atrial function in vivo and Ca transients (CaT) (Fluo4-AM, field stim) in atrial cardiomyocytes of ZSF-1 rats without (Ln; lean hypertensive) and with metabolic syndrome (Ob; obese, hypertensive, diabetic) and HFpEF. RESULTS At 21weeks Ln showed an increased left ventricular (LV) mass and left ventricular end-diastolic pressure (LVEDP), but unchanged left atrial (LA) size and preserved atrial ejection fraction vs. wild-type (WT). CaT amplitude in atrial cardiomyocytes was increased in Ln (2.9±0.2 vs. 2.3±0.2F/F0 in WT; n=22 cells/group; p<0.05). Studying subcellular Ca release in more detail, we found that local central cytosolic CaT amplitude was increased, while subsarcolemmal CaT amplitudes remained unchanged. Moreover, Sarcoplasmic reticulum (SR) Ca content (caffeine) was preserved while Ca spark frequency and tetracaine-dependent SR Ca leak were significantly increased in Ln. Ob mice developed a HFpEF phenotype in vivo, LA area was significantly increased and atrial in vivo function was impaired, despite increased atrial CaT amplitudes in vitro (2.8±0.2; p<0.05 vs. WT). Ob cells showed alterations of the tubular network possibly contributing to the observed phenotype. CaT kinetics as well as SR Ca in Ob were not significantly different from WT, but SR Ca leak remained increased. Angiotensin II (Ang II) reduced in vitro cytosolic CaT amplitudes and let to active nuclear Ca release in Ob but not in Ln or WT. SUMMARY In hypertensive ZSF-1 rats, a possibly compensatory increase of cytosolic CaT amplitude and increased SR Ca leak precede atrial remodeling and HFpEF. Atrial remodeling in ZSF-1 HFpEF is associated with an altered tubular network in-vitro and atrial contractile dysfunction in vivo, indicating insufficient compensation. Atrial cardiomyocyte dysfunction in vitro is induced by the addition of angiotensin II.
Collapse
|
38
|
Shapovalov G, Ritaine A, Bidaux G, Slomianny C, Borowiec AS, Gordienko D, Bultynck G, Skryma R, Prevarskaya N. Organelle membrane derived patches: reshaping classical methods for new targets. Sci Rep 2017; 7:14082. [PMID: 29074990 PMCID: PMC5658434 DOI: 10.1038/s41598-017-13968-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 10/04/2017] [Indexed: 12/12/2022] Open
Abstract
Intracellular ion channels are involved in multiple signaling processes, including such crucial ones as regulation of cellular motility and fate. With 95% of the cellular membrane belonging to intracellular organelles, it is hard to overestimate the importance of intracellular ion channels. Multiple studies have been performed on these channels over the years, however, a unified approach allowing not only to characterize their activity but also to study their regulation by partner proteins, analogous to the patch clamp “golden standard”, is lacking. Here, we present a universal approach that combines the extraction of intracellular membrane fractions with the preparation of patchable substrates that allows to characterize these channels in endogenous protein environment and to study their regulation by partner proteins. We validate this method by characterizing activity of multiple intracellular ion channels localized to different organelles and by providing detailed electrophysiological characterization of the regulation of IP3R activity by endogenous Bcl-2. Thus, after synthesis and reshaping of the well-established approaches, organelle membrane derived patch clamp provides the means to assess ion channels from arbitrary cellular membranes at the single channel level.
Collapse
Affiliation(s)
- George Shapovalov
- Inserm U1003, Equipe Labellisée par la Ligue Nationale Contre le Cancer, Université de Sciences et Technologies de Lille (USTL), F-59655, Villeneuve d'Ascq, France.,Laboratory of Excellence, Ion Channels Science and Therapeutics; Université Lille I Sciences et Technologies, Villeneuve d'Ascq, France
| | - Abigaël Ritaine
- Inserm U1003, Equipe Labellisée par la Ligue Nationale Contre le Cancer, Université de Sciences et Technologies de Lille (USTL), F-59655, Villeneuve d'Ascq, France.,Laboratory of Excellence, Ion Channels Science and Therapeutics; Université Lille I Sciences et Technologies, Villeneuve d'Ascq, France
| | - Gabriel Bidaux
- Inserm U1003, Equipe Labellisée par la Ligue Nationale Contre le Cancer, Université de Sciences et Technologies de Lille (USTL), F-59655, Villeneuve d'Ascq, France.,Laboratory of Excellence, Ion Channels Science and Therapeutics; Université Lille I Sciences et Technologies, Villeneuve d'Ascq, France.,Laboratoire INSERM U1060, CarMeN Laboratory, Claude Bernard Lyon 1 University, 8, avenue Rockfeller, F-69373, Lyon, France
| | - Christian Slomianny
- Inserm U1003, Equipe Labellisée par la Ligue Nationale Contre le Cancer, Université de Sciences et Technologies de Lille (USTL), F-59655, Villeneuve d'Ascq, France.,Laboratory of Excellence, Ion Channels Science and Therapeutics; Université Lille I Sciences et Technologies, Villeneuve d'Ascq, France
| | - Anne-Sophie Borowiec
- Inserm U1003, Equipe Labellisée par la Ligue Nationale Contre le Cancer, Université de Sciences et Technologies de Lille (USTL), F-59655, Villeneuve d'Ascq, France.,Laboratory of Excellence, Ion Channels Science and Therapeutics; Université Lille I Sciences et Technologies, Villeneuve d'Ascq, France.,Laboratoire INSERM U1060, CarMeN Laboratory, Claude Bernard Lyon 1 University, 8, avenue Rockfeller, F-69373, Lyon, France
| | - Dmitri Gordienko
- Inserm U1003, Equipe Labellisée par la Ligue Nationale Contre le Cancer, Université de Sciences et Technologies de Lille (USTL), F-59655, Villeneuve d'Ascq, France.,Laboratory of Excellence, Ion Channels Science and Therapeutics; Université Lille I Sciences et Technologies, Villeneuve d'Ascq, France
| | - Geert Bultynck
- KU Leuven, Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, Herestraat 49, BE-3000, Leuven, Belgium
| | - Roman Skryma
- Inserm U1003, Equipe Labellisée par la Ligue Nationale Contre le Cancer, Université de Sciences et Technologies de Lille (USTL), F-59655, Villeneuve d'Ascq, France.,Laboratory of Excellence, Ion Channels Science and Therapeutics; Université Lille I Sciences et Technologies, Villeneuve d'Ascq, France
| | - Natalia Prevarskaya
- Inserm U1003, Equipe Labellisée par la Ligue Nationale Contre le Cancer, Université de Sciences et Technologies de Lille (USTL), F-59655, Villeneuve d'Ascq, France. .,Laboratory of Excellence, Ion Channels Science and Therapeutics; Université Lille I Sciences et Technologies, Villeneuve d'Ascq, France.
| |
Collapse
|
39
|
Blatter LA. The intricacies of atrial calcium cycling during excitation-contraction coupling. J Gen Physiol 2017; 149:857-865. [PMID: 28798277 PMCID: PMC5583713 DOI: 10.1085/jgp.201711809] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 07/12/2017] [Indexed: 12/20/2022] Open
Abstract
Blatter discusses the initiation and spread of Ca release, Ca store depletion, and release termination in atrial myocytes.
Collapse
Affiliation(s)
- Lothar A Blatter
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, IL
| |
Collapse
|
40
|
Archer CR, Robinson EL, Drawnel FM, Roderick HL. Endothelin-1 promotes hypertrophic remodelling of cardiac myocytes by activating sustained signalling and transcription downstream of endothelin type A receptors. Cell Signal 2017; 36:240-254. [PMID: 28412414 PMCID: PMC5486433 DOI: 10.1016/j.cellsig.2017.04.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 03/21/2017] [Accepted: 04/12/2017] [Indexed: 02/07/2023]
Abstract
G-protein coupled receptor (GPCR) mediated activation of the MAPK signalling cascade is a key pathway in the induction of hypertrophic remodelling of the heart – a response to pathological cues including hypertension and myocardial infarction. While levels of pro-hypertrophic hormone agonists of GPCRs increase during periods of greater workload to enhance cardiac output, hypertrophy does not necessarily result. Here we investigated the relationship between the duration of exposure to the pro-hypertrophic GPCR agonist endothelin-1 (ET-1) and the induction of hypertrophic remodelling in neonatal rat ventricular myocytes (NRVM) and in the adult rat heart in vivo. Notably, a 15 min pulse of ET-1 was sufficient to induce markers of hypertrophy that were present when measured at 24 h in vivo and 48 h in vitro. The persistence of ET-1 action was insensitive to ET type A receptor (ETA receptor) antagonism with BQ123. The extended effects of ET-1 were dependent upon sustained MAPK signalling and involved persistent transcription. Inhibitors of endocytosis however conferred sensitivity upon the hypertrophic response to BQ123, suggesting that endocytosis of ETA receptors following ligand binding preserves their active state by protection against antagonist. Contrastingly, α1 adrenergic-induced hypertrophic responses required the continued presence of agonist and were sensitive to antagonist. These studies shed new light on strategies to pharmacologically intervene in the action of different pro-hypertrophic mediators. Acute ET-1 exposure elicits a long-lasting cardiac myocyte hypertrophic response. ET-1 effects depend on persistent MAPK signalling and active transcription. ET-1 elicited hypertrophy is insensitive to subsequent ETA receptor antagonism. Endocytosis inhibition potentiates ET-1-induction of hypertrophy markers. Endocytosis inhibition sensitises effects of ET-1 to ETA receptor antagonist.
Collapse
Affiliation(s)
| | - Emma L Robinson
- Laboratory of Experimental Cardiology, Dept. of Cardiovascular Sciences, KU Leuven, Campus Gasthuisberg, Herestraat 49, B-3000, Leuven, Belgium
| | - Faye M Drawnel
- The Babraham Institute, Babraham, Cambridge, CB22 3AT, UK
| | - H Llewelyn Roderick
- Laboratory of Experimental Cardiology, Dept. of Cardiovascular Sciences, KU Leuven, Campus Gasthuisberg, Herestraat 49, B-3000, Leuven, Belgium.
| |
Collapse
|
41
|
Multiple H + sensors mediate the extracellular acidification-induced [Ca 2+] i elevation in cultured rat ventricular cardiomyocytes. Sci Rep 2017; 7:44951. [PMID: 28332558 PMCID: PMC5362981 DOI: 10.1038/srep44951] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 02/16/2017] [Indexed: 02/04/2023] Open
Abstract
Acidosis has been known to cause “Ca2+ transients”, however, the mechanism is still uncertain. Here, we demonstrated that multiple H+ sensors, such as ASICs, TRPV1 and proton-sensing G protein coupled receptors (GPCRs) are involved in extracellular acidification-induced intracellular calcium ([Ca2+]i) elevation. By using calcium imaging measures, we observed that both ASIC and TRPV1 channels inhibitors suppressed the [Ca2+]i elevation induced by extracellular acidosis in cultured rat cardiac myocytes. Then, both channels mRNA and proteins were identified by RT-PCR, western blotting and immunofluorescence. ASIC-like and TRPV1-like currents were induced by extracellular acidification, suggesting that functional ASIC and TRPV1 channels jointly mediated extracellular calcium entry. Furthermore, either pre-exhaustion of sarcoplasmic reticulum (SR) Ca2+ with thapsigargin or IP3 receptor blocker 2-APB or PLC inhibitor U73122 significantly attenuated the elevation of [Ca2+]i, indicating that the intracellular Ca2+ stores and the PLC-IP3 signaling also contributed to the acidosis-induced elevation of [Ca2+]i. By using genetic and pharmacological approaches, we identified that ovarian cancer G protein-coupled receptor 1 (OGR1) might be another main component in acidosis-induced release of [Ca2+]i. These results suggest that multiple H+-sensitive receptors are involved in “Ca2+ transients” induced by acidosis in the heart.
Collapse
|
42
|
Pabbidi MR, Ji X, Maxwell JT, Mignery GA, Samarel AM, Lipsius SL. Inhibition of cAMP-Dependent PKA Activates β2-Adrenergic Receptor Stimulation of Cytosolic Phospholipase A2 via Raf-1/MEK/ERK and IP3-Dependent Ca2+ Signaling in Atrial Myocytes. PLoS One 2016; 11:e0168505. [PMID: 27977772 PMCID: PMC5158063 DOI: 10.1371/journal.pone.0168505] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 12/01/2016] [Indexed: 11/19/2022] Open
Abstract
We previously reported in atrial myocytes that inhibition of cAMP-dependent protein kinase (PKA) by laminin (LMN)-integrin signaling activates β2-adrenergic receptor (β2-AR) stimulation of cytosolic phospholipase A2 (cPLA2). The present study sought to determine the signaling mechanisms by which inhibition of PKA activates β2-AR stimulation of cPLA2. We therefore determined the effects of zinterol (0.1 μM; zint-β2-AR) to stimulate ICa,L in atrial myocytes in the absence (+PKA) and presence (-PKA) of the PKA inhibitor (1 μM) KT5720 and compared these results with atrial myocytes attached to laminin (+LMN). Inhibition of Raf-1 (10 μM GW5074), phospholipase C (PLC; 0.5 μM edelfosine), PKC (4 μM chelerythrine) or IP3 receptor (IP3R) signaling (2 μM 2-APB) significantly inhibited zint-β2-AR stimulation of ICa,L in-PKA but not +PKA myocytes. Western blots showed that zint-β2-AR stimulation increased ERK1/2 phosphorylation in-PKA compared to +PKA myocytes. Adenoviral (Adv) expression of dominant negative (dn) -PKCα, dn-Raf-1 or an IP3 affinity trap, each inhibited zint-β2-AR stimulation of ICa,L in + LMN myocytes compared to control +LMN myocytes infected with Adv-βgal. In +LMN myocytes, zint-β2-AR stimulation of ICa,L was enhanced by adenoviral overexpression of wild-type cPLA2 and inhibited by double dn-cPLA2S505A/S515A mutant compared to control +LMN myocytes infected with Adv-βgal. In-PKA myocytes depletion of intracellular Ca2+ stores by 5 μM thapsigargin failed to inhibit zint-β2-AR stimulation of ICa,L via cPLA2. However, disruption of caveolae formation by 10 mM methyl-β-cyclodextrin inhibited zint-β2-AR stimulation of ICa,L in-PKA myocytes significantly more than in +PKA myocytes. We conclude that inhibition of PKA removes inhibition of Raf-1 and thereby allows β2-AR stimulation to act via PKCα/Raf-1/MEK/ERK1/2 and IP3-mediated Ca2+ signaling to stimulate cPLA2 signaling within caveolae. These findings may be relevant to the remodeling of β-AR signaling in failing and/or aging heart, both of which exhibit decreases in adenylate cyclase activity.
Collapse
MESH Headings
- Animals
- Calcium Signaling/drug effects
- Calcium Signaling/genetics
- Carbazoles/pharmacology
- Cats
- Cells, Cultured
- Cyclic AMP-Dependent Protein Kinases/antagonists & inhibitors
- Cyclic AMP-Dependent Protein Kinases/metabolism
- Extracellular Signal-Regulated MAP Kinases/genetics
- Extracellular Signal-Regulated MAP Kinases/metabolism
- Female
- Group IV Phospholipases A2/genetics
- Group IV Phospholipases A2/metabolism
- Heart Atria/cytology
- Inositol 1,4,5-Trisphosphate Receptors/genetics
- Inositol 1,4,5-Trisphosphate Receptors/metabolism
- Male
- Mitogen-Activated Protein Kinase Kinases/genetics
- Mitogen-Activated Protein Kinase Kinases/metabolism
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Proto-Oncogene Proteins c-raf/genetics
- Proto-Oncogene Proteins c-raf/metabolism
- Pyrroles/pharmacology
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Signal Transduction/genetics
- Signal Transduction/physiology
Collapse
Affiliation(s)
- M. R. Pabbidi
- Department of Pharmacology, University of Mississippi Medical Center, Jackson, MS, United States of America
- * E-mail:
| | - X. Ji
- Department of Physiology, Loyola University Medical Center, Maywood, IL, United States of America
| | - J. T. Maxwell
- Department of Physiology, Loyola University Medical Center, Maywood, IL, United States of America
| | - G. A. Mignery
- Department of Physiology, Loyola University Medical Center, Maywood, IL, United States of America
| | - A. M. Samarel
- Department of Medicine, Loyola University Medical Center, Maywood, IL, United States of America
| | - S. L. Lipsius
- Department of Physiology, Loyola University Medical Center, Maywood, IL, United States of America
| |
Collapse
|
43
|
Garcia MI, Boehning D. Cardiac inositol 1,4,5-trisphosphate receptors. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1864:907-914. [PMID: 27884701 DOI: 10.1016/j.bbamcr.2016.11.017] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 11/16/2016] [Accepted: 11/16/2016] [Indexed: 10/20/2022]
Abstract
Calcium is a second messenger that regulates almost all cellular functions. In cardiomyocytes, calcium plays an integral role in many functions including muscle contraction, gene expression, and cell death. Inositol 1,4,5-trisphosphate receptors (IP3Rs) are a family of calcium channels that are ubiquitously expressed in all tissues. In the heart, IP3Rs have been associated with regulation of cardiomyocyte function in response to a variety of neurohormonal agonists, including those implicated in cardiac disease. Notably, IP3R activity is thought to be essential for mediating the hypertrophic response to multiple stimuli including endothelin-1 and angiotensin II. In this review, we will explore the functional implications of IP3R activity in the heart in health and disease.
Collapse
Affiliation(s)
- M Iveth Garcia
- Cell Biology Graduate Program, University of Texas Medical Branch, Galveston, TX 77555, United States; Department of Biochemistry and Molecular Biology, McGovern Medical School at UTHealth, Houston, TX 77030, United States
| | - Darren Boehning
- Department of Biochemistry and Molecular Biology, McGovern Medical School at UTHealth, Houston, TX 77030, United States.
| |
Collapse
|
44
|
Haque ZK, Wang DZ. How cardiomyocytes sense pathophysiological stresses for cardiac remodeling. Cell Mol Life Sci 2016; 74:983-1000. [PMID: 27714411 DOI: 10.1007/s00018-016-2373-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 09/01/2016] [Accepted: 09/19/2016] [Indexed: 12/14/2022]
Abstract
In the past decades, the cardiovascular community has laid out the fundamental signaling cascades that become awry in the cardiomyocyte during the process of pathologic cardiac remodeling. These pathways are initiated at the cell membrane and work their way to the nucleus to mediate gene expression. Complexity is multiplied as the cardiomyocyte is subjected to cross talk with other cells as well as a barrage of extracellular stimuli and mechanical stresses. In this review, we summarize the signaling cascades that play key roles in cardiac function and then we proceed to describe emerging concepts of how the cardiomyocyte senses the mechanical and environmental stimuli to transition to the deleterious genetic program that defines pathologic cardiac remodeling. As a highlighting example of these processes, we illustrate the transition from a compensated hypertrophied myocardium to a decompensated failing myocardium, which is clinically manifested as decompensated heart failure.
Collapse
Affiliation(s)
- Zaffar K Haque
- Department of Cardiology, Boston Children's Hospital, Harvard Medical School, 1260 John F. Enders Research Bldg, 320 Longwood Ave, Boston, MA, 02115, USA.
| | - Da-Zhi Wang
- Department of Cardiology, Boston Children's Hospital, Harvard Medical School, 1260 John F. Enders Research Bldg, 320 Longwood Ave, Boston, MA, 02115, USA
| |
Collapse
|
45
|
Castillo-Galán S, Quezada S, Moraga FA, Ebensperger G, Herrera EA, Beñaldo F, Hernandez I, Ebensperger R, Ramirez S, Llanos AJ, Reyes RV. 2-AMINOETHYLDIPHENYLBORINATE MODIFIES THE PULMONARY CIRCULATION IN PULMONARY HYPERTENSIVE NEWBORN LAMBS WITH PARTIAL GESTATION AT HIGH ALTITUDE. Am J Physiol Lung Cell Mol Physiol 2016; 311:L788-L799. [PMID: 27542806 DOI: 10.1152/ajplung.00230.2016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 08/14/2016] [Indexed: 12/22/2022] Open
Abstract
Calcium signaling through store operated channels (SOC) is involved in hypoxic pulmonary hypertension. We determined whether a treatment with 2-aminoethyldiphenylborinate (2-APB), a compound with SOC blocker activity, reduces pulmonary hypertension and vascular remodeling. Twelve newborn lambs exposed to perinatal chronic hypoxia were studied, 6 of them received a 2-APB treatment and the other 6 received vehicle treatment, for 10 days in both cases. Throughout this period, we recorded cardiopulmonary variables and on day 11 we evaluated the response to an acute hypoxic challenge. Additionally, we assessed the vasoconstrictor and vasodilator function in isolated pulmonary arteries as well as their remodeling in lung slices. 2-APB reduced pulmonary arterial pressure at the third and tenth days, cardiac output between the fourth and eighth days, and pulmonary vascular resistance at the tenth day of treatment. The pulmonary vasoconstrictor response to acute hypoxia was reduced by the end of treatment. 2-APB also decreased maximal vasoconstrictor response to the thromboxane mimetic U46619 and endothelin-1 and increased maximal relaxation to 8-Br-cGMP. The maximal relaxation and potency to phosphodiesterase-5 and Rho-kinase inhibition with sildenafil and fasudil respectively, were also increased. Finally, 2-APB reduced the medial and adventitial layers' thickness, the expression of α-actin and the percentage of Ki67+ nuclei of small pulmonary arteries. Taken together, our results indicate that 2-APB reduces pulmonary hypertension, vasoconstrictor responses and pathological remodeling in pulmonary hypertensive lambs. We conclude that SOC targeting may be a useful strategy for the treatment of neonatal pulmonary hypertension, however, further testing of specific blockers is needed.
Collapse
Affiliation(s)
| | - Sebastián Quezada
- Universidad de Chile, Facultad de Medicina, Instituto de Ciencias Biomédicas (ICBM)
| | | | - Germán Ebensperger
- Facultad de Medicina, Universidad de Chile, Instituto de Ciencias Biomédicas (ICBM), Santiago, Chile
| | | | | | - Ismael Hernandez
- Facultad de Medicina, Universidad de Chile, Instituto de Ciencias Biomédicas (ICBM), Santiago, Chile
| | - Renato Ebensperger
- Facultad de Medicina, Universidad de Chile, Instituto de Ciencias Biomédicas (ICBM), Santiago, Chile
| | - Santiago Ramirez
- Facultad de Medicina, Universidad de Chile, Instituto de Ciencias Biomédicas (ICBM), Santiago, Chile
| | | | - Roberto V Reyes
- Universidad de Chile, Facultad de Medicina, Instituto de Ciencias Biomédicas (ICBM)
| |
Collapse
|
46
|
Hohendanner F, Maxwell JT, Blatter LA. Cytosolic and nuclear calcium signaling in atrial myocytes: IP3-mediated calcium release and the role of mitochondria. Channels (Austin) 2016; 9:129-38. [PMID: 25891132 DOI: 10.1080/19336950.2015.1040966] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
In rabbit atrial myocytes Ca signaling has unique features due to the lack of transverse (t) tubules, the spatial arrangement of mitochondria and the contribution of inositol-1,4,5-trisphosphate (IP3) receptor-induced Ca release (IICR). During excitation-contraction coupling action potential-induced elevation of cytosolic [Ca] originates in the cell periphery from Ca released from the junctional sarcoplasmic reticulum (j-SR) and then propagates by Ca-induced Ca release from non-junctional (nj-) SR toward the cell center. The subsarcolemmal region between j-SR and the first array of nj-SR Ca release sites is devoid of mitochondria which results in a rapid propagation of activation through this domain, whereas the subsequent propagation through the nj-SR network occurs at a velocity typical for a propagating Ca wave. Inhibition of mitochondrial Ca uptake with the Ca uniporter blocker Ru360 accelerates propagation and increases the amplitude of Ca transients (CaTs) originating from nj-SR. Elevation of cytosolic IP3 levels by rapid photolysis of caged IP3 has profound effects on the magnitude of subcellular CaTs with increased Ca release from nj-SR and enhanced CaTs in the nuclear compartment. IP3 uncaging restricted to the nucleus elicites 'mini'-Ca waves that remain confined to this compartment. Elementary IICR events (Ca puffs) preferentially originate in the nucleus in close physical association with membrane structures of the nuclear envelope and the nucleoplasmic reticulum. The data suggest that in atrial myocytes the nucleus is an autonomous Ca signaling domain where Ca dynamics are primarily governed by IICR.
Collapse
Key Words
- 2-APB, 2-aminoethoxydiphenyl borate
- AP, action potential
- CICR, Ca-induced Ca release
- CRU, Ca release units
- CT, central
- CaT, Ca transient
- ECC, excitation-contraction coupling
- IICR
- IICR, IP3R-induced Ca release
- IP3
- IP3R, Inositol-1,4,5-trisphosphate receptor
- LCC, L-type Ca channels
- MCU, mitochondrial Ca uniporter
- NE, nuclear envelope
- NFAT, nuclear factor of activated T cells
- NPR, nucleoplasmic reticulum
- RyR, ryanodine receptor
- SR, sarcoplasmic reticulum
- SS, subsarcolemmal
- TF50, time to half-maximal amplitude
- TZ, transition zone.
- [Ca]i, cytosolic Ca concentration
- [Ca]mito, mitochondrial Ca concentration
- atria
- excitation-contraction coupling
- j-SR, junctional SR
- mitochondria
- nj-SR, non-junctional SR
- nuclear calcium
- t-tubule, transverse tubule
Collapse
Affiliation(s)
- Felix Hohendanner
- a Department of Molecular Biophysics and Physiology ; Rush University Medical Center ; Chicago , IL USA
| | | | | |
Collapse
|
47
|
Viola HM, Hool LC. Role of the cytoskeleton in communication between L-type Ca(2+) channels and mitochondria. Clin Exp Pharmacol Physiol 2015; 40:295-304. [PMID: 23551128 DOI: 10.1111/1440-1681.12072] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 02/25/2013] [Accepted: 02/26/2013] [Indexed: 12/15/2022]
Abstract
The L-type Ca(2+) channel is the main route for Ca(2+) entry into cardiac myocytes, which is essential for the maintenance of cardiac excitation and contraction. Alterations in L-type Ca(2+) channel activity and Ca(2+) homeostasis have been implicated in the development of cardiomyopathies. Cardiac excitation and contraction is fuelled by ATP, synthesized predominantly by the mitochondria via the Ca(2+)-dependent process oxidative phosphorylation. Mitochondrial reactive oxygen species (ROS) are by-products of oxidative phosphorylation and are associated with the development of cardiac pathology. The cytoskeleton plays a role in the communication of signals from the plasma membrane to intracellular organelles. There is good evidence that both L-type Ca(2+) channel activity and mitochondrial function can be modulated by changes in the cytoskeletal network. Activation of the L-type Ca(2+) channel can regulate mitochondrial function through cytoskeletal proteins as a result of transmission of movement from the β(2)-subunit of the channel that occurs during activation and inactivation of the channel. An association between cytoskeletal proteins and the mitochondrial voltage-dependent anion channel (VDAC) may play a role in this response. The L-type Ca(2+) channel is the initiator of contraction in cardiac muscle and the VDAC is responsible for regulating mitochondrial ATP/ADP trafficking. This article presents evidence that a functional coupling between L-type Ca(2+) channels and mitochondria may assist in meeting myocardial energy demand on a beat-to-beat basis.
Collapse
Affiliation(s)
- Helena M Viola
- Cardiovascular Electrophysiology Laboratory, School of Anatomy, Physiology and Human Biology, The University of Western Australia, Crawley, WA, Australia
| | | |
Collapse
|
48
|
Sipido KR, Macquaide N, Bito V. A systematic approach for assessing Ca²⁺ handling in cardiac myocytes. Cold Spring Harb Protoc 2015; 2015:431-3. [PMID: 25934941 DOI: 10.1101/pdb.top066142] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In cardiac myocytes, Ca(2+) release from the sarcoplasmic reticulum (SR) Ca(2+) store through the opening of ryanodine receptors (RyRs) is the major source of Ca(2+) for activation of myofilaments and contraction. Over the past 20 years, tools have become available to study this release process in detail, allowing new insights into the regulation of SR Ca(2+) release and RyR function. To assess these processes, we recommend and here review a systematic approach that evaluates the essential transport mechanisms and Ca(2+) fluxes in isolated single cardiac myocytes by using fluorescent Ca(2+) indicators and whole-cell recording of membrane voltage and ionic currents under voltage clamp. The approach includes an assessment of the L-type Ca(2+) current as a trigger for opening of RyRs and release of SR Ca(2+), of the SR Ca(2+) content, of intrinsic properties of RyRs, and of Ca(2+)-removal systems.
Collapse
Affiliation(s)
- Karin R Sipido
- Division of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, Belgium
| | - Niall Macquaide
- Division of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, Belgium
| | - Virginie Bito
- Division of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, Belgium
| |
Collapse
|
49
|
Hohendanner F, Walther S, Maxwell JT, Kettlewell S, Awad S, Smith GL, Lonchyna VA, Blatter LA. Inositol-1,4,5-trisphosphate induced Ca2+ release and excitation-contraction coupling in atrial myocytes from normal and failing hearts. J Physiol 2014; 593:1459-77. [PMID: 25416623 DOI: 10.1113/jphysiol.2014.283226] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 11/10/2014] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Impaired calcium (Ca(2+)) signalling is the main contributor to depressed ventricular contractile function and occurrence of arrhythmia in heart failure (HF). Here we report that in atrial cells of a rabbit HF model, Ca(2+) signalling is enhanced and we identified the underlying cellular mechanisms. Enhanced Ca(2+) transients (CaTs) are due to upregulation of inositol-1,4,5-trisphosphate receptor induced Ca(2+) release (IICR) and decreased mitochondrial Ca(2+) sequestration. Enhanced IICR, however, together with an increased activity of the sodium-calcium exchange mechanism, also facilitates spontaneous Ca(2+) release in form of arrhythmogenic Ca(2+) waves and spontaneous action potentials, thus enhancing the arrhythmogenic potential of atrial cells. Our data show that enhanced Ca(2+) signalling in HF provides atrial cells with a mechanism to improve ventricular filling and to maintain cardiac output, but also increases the susceptibility to develop atrial arrhythmias facilitated by spontaneous Ca(2+) release. ABSTRACT We studied excitation-contraction coupling (ECC) and inositol-1,4,5-triphosphate (IP3)-dependent Ca(2+) release in normal and heart failure (HF) rabbit atrial cells. Left ventricular HF was induced by combined volume and pressure overload. In HF atrial myocytes diastolic [Ca(2+)]i was increased, action potential (AP)-induced Ca(2+) transients (CaTs) were larger in amplitude, primarily due to enhanced Ca(2+) release from central non-junctional sarcoplasmic reticulum (SR) and centripetal propagation of activation was accelerated, whereas HF ventricular CaTs were depressed. The larger CaTs were due to enhanced IP3 receptor-induced Ca(2+) release (IICR) and reduced mitochondrial Ca(2+) buffering, consistent with a reduced mitochondrial density and Ca(2+) uptake capacity in HF. Elementary IP3 receptor-mediated Ca(2+) release events (Ca(2+) puffs) were more frequent in HF atrial myoctes and were detected more often in central regions of the non-junctional SR compared to normal cells. HF cells had an overall higher frequency of spontaneous Ca(2+) waves and a larger fraction of waves (termed arrhythmogenic Ca(2+) waves) triggered APs and global CaTs. The higher propensity of arrhythmogenic Ca(2+) waves resulted from the combined action of enhanced IICR and increased activity of sarcolemmal Na(+)-Ca(2+) exchange depolarizing the cell membrane. In conclusion, the data support the hypothesis that in atrial myocytes from hearts with left ventricular failure, enhanced CaTs during ECC exert positive inotropic effects on atrial contractility which facilitates ventricular filling and contributes to maintaining cardiac output. However, HF atrial cells were also more susceptible to developing arrhythmogenic Ca(2+) waves which might form the substrate for atrial rhythm disorders frequently encountered in HF.
Collapse
Affiliation(s)
- Felix Hohendanner
- Department of Molecular Biophysics and Physiology, Rush University Medical Center, Chicago, IL, 60612, USA
| | | | | | | | | | | | | | | |
Collapse
|
50
|
Vervloessem T, Yule DI, Bultynck G, Parys JB. The type 2 inositol 1,4,5-trisphosphate receptor, emerging functions for an intriguing Ca²⁺-release channel. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1853:1992-2005. [PMID: 25499268 DOI: 10.1016/j.bbamcr.2014.12.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 12/02/2014] [Accepted: 12/03/2014] [Indexed: 12/19/2022]
Abstract
The inositol 1,4,5-trisphosphate (IP3) receptor (IP3R) type 2 (IP3R2) is an intracellular Ca²⁺-release channel located on the endoplasmic reticulum (ER). IP3R2 is characterized by a high sensitivity to both IP3 and ATP and is biphasically regulated by Ca²⁺. Furthermore, IP3R2 is modulated by various protein kinases. In addition to its regulation by protein kinase A, IP3R2 forms a complex with adenylate cyclase 6 and is directly regulated by cAMP. Finally, in the ER, IP3R2 is less mobile than the other IP3R isoforms, while its functional properties appear dominant in heterotetramers. These properties make the IP3R2 a Ca²⁺ channel with exquisite properties for setting up intracellular Ca²⁺ signals with unique characteristics. IP3R2 plays a crucial role in the function of secretory cell types (e.g. pancreatic acinar cells, hepatocytes, salivary gland, eccrine sweat gland). In cardiac myocytes, the role of IP3R2 appears more complex, because, together with IP3R1, it is needed for normal cardiogenesis, while its aberrant activity is implicated in cardiac hypertrophy and arrhythmias. Most importantly, its high sensitivity to IP3 makes IP3R2 a target for anti-apoptotic proteins (e.g. Bcl-2) in B-cell cancers. Disrupting IP3R/Bcl-2 interaction therefore leads in those cells to increased Ca²⁺ release and apoptosis. Intriguingly, IP3R2 is not only implicated in apoptosis but also in the induction of senescence, another tumour-suppressive mechanism. These results were the first to unravel the physiological and pathophysiological role of IP3R2 and we anticipate that further progress will soon be made in understanding the function of IP3R2 in various tissues and organs.
Collapse
Affiliation(s)
- Tamara Vervloessem
- KU Leuven, Laboratory of Molecular and Cellular Signalling, Department of Cellular and Molecular Medicine, Leuven, Belgium
| | - David I Yule
- University of Rochester, Department of Pharmacology and Physiology, Rochester, NY, USA
| | - Geert Bultynck
- KU Leuven, Laboratory of Molecular and Cellular Signalling, Department of Cellular and Molecular Medicine, Leuven, Belgium
| | - Jan B Parys
- KU Leuven, Laboratory of Molecular and Cellular Signalling, Department of Cellular and Molecular Medicine, Leuven, Belgium.
| |
Collapse
|