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Kampfer AJ, Balog EM. Electrical polarity-dependent gating and a unique subconductance of RyR2 induced by S-adenosyl methionine via the ATP binding site. J Biochem 2021; 170:739-752. [PMID: 34523682 DOI: 10.1093/jb/mvab093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 08/30/2021] [Indexed: 11/14/2022] Open
Abstract
S-Adenosyl-l-methionine (SAM) was used to probe the functional effects exerted via the RyR2 adenine nucleotide binding site. Single channel experiments revealed that SAM applied to the cytoplasmic face of RyR2 had complex voltage dependent effects on channel gating and conductance. At positive transmembrane holding potentials, SAM caused a striking reduction in channel openings and a reduced channel conductance. In contrast, at negative potentials SAM promoted a clearly resolved subconductance state. At membrane potentials between -75 and -25 mV the open probability of the subconductance state was independent of voltage. ATP, but not the non-adenosine based RyR activator 4-chloro-m-cresol interfered with the effects of SAM at both negative and positive potentials. This suggests that ATP and SAM interact with a common binding site. Molecular docking showed SAM bound to the adenine nucleotide-binding site and formed a hydrogen bond to Glu4886 in the C-terminal end of the S6 alpha helix. In this configuration SAM may alter the conformation of the RyR2 ion conduction pathway. This work provides novel insight into potential functional outcomes of ligand binding to the RyR adenine nucleotide binding site.
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Affiliation(s)
- Angela J Kampfer
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332
| | - Edward M Balog
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332
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2
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Muscle Glycogen Metabolism and High-Intensity Exercise Performance: A Narrative Review. Sports Med 2021; 51:1855-1874. [PMID: 33900579 DOI: 10.1007/s40279-021-01475-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/08/2021] [Indexed: 02/06/2023]
Abstract
Muscle glycogen is the main substrate during high-intensity exercise and large reductions can occur after relatively short durations. Moreover, muscle glycogen is stored heterogeneously and similarly displays a heterogeneous and fiber-type specific depletion pattern with utilization in both fast- and slow-twitch fibers during high-intensity exercise, with a higher degradation rate in the former. Thus, depletion of individual fast- and slow-twitch fibers has been demonstrated despite muscle glycogen at the whole-muscle level only being moderately lowered. In addition, muscle glycogen is stored in specific subcellular compartments, which have been demonstrated to be important for muscle function and should be considered as well as global muscle glycogen availability. In the present review, we discuss the importance of glycogen metabolism for single and intermittent bouts of high-intensity exercise and outline possible underlying mechanisms for a relationship between muscle glycogen and fatigue during these types of exercise. Traditionally this relationship has been attributed to a decreased ATP resynthesis rate due to inadequate substrate availability at the whole-muscle level, but emerging evidence points to a direct coupling between muscle glycogen and steps in the excitation-contraction coupling including altered muscle excitability and calcium kinetics.
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Sanchez C, Berthier C, Tourneur Y, Monteiro L, Allard B, Csernoch L, Jacquemond V. Detection of Ca2+ transients near ryanodine receptors by targeting fluorescent Ca2+ sensors to the triad. J Gen Physiol 2021; 153:211757. [PMID: 33538764 PMCID: PMC7868779 DOI: 10.1085/jgp.202012592] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 12/03/2020] [Accepted: 12/23/2020] [Indexed: 11/23/2022] Open
Abstract
In intact muscle fibers, functional properties of ryanodine receptor (RYR)–mediated sarcoplasmic reticulum (SR) Ca2+ release triggered by activation of the voltage sensor CaV1.1 have so far essentially been addressed with diffusible Ca2+-sensitive dyes. Here, we used a domain (T306) of the protein triadin to target the Ca2+-sensitive probe GCaMP6f to the junctional SR membrane, in the immediate vicinity of RYR channels, within the triad region. Fluorescence of untargeted GCaMP6f was distributed throughout the muscle fibers and experienced large Ca2+-dependent changes, with obvious kinetic delays, upon application of voltage-clamp depolarizing pulses. Conversely, T306-GCaMP6f localized to the triad and generated Ca2+-dependent fluorescence transients of lower amplitude and faster kinetics for low and intermediate levels of Ca2+ release than those of untargeted GCaMP6f. By contrast, model simulation of the spatial gradients of Ca2+ following Ca2+ release predicted limited kinetic differences under the assumptions that the two probes were present at the same concentration and suffered from identical kinetic limitations. At the spatial level, T306-GCaMP6f transients within distinct regions of a same fiber yielded a uniform time course, even at low levels of Ca2+ release activation. Similar observations were made using GCaMP6f fused to the γ1 auxiliary subunit of CaV1.1. Despite the probe's limitations, our results point out the remarkable synchronicity of voltage-dependent Ca2+ release activation and termination among individual triads and highlight the potential of the approach to visualize activation or closure of single groups of RYR channels. We anticipate targeting of improved Ca2+ sensors to the triad will provide illuminating insights into physiological normal RYR function and its dysfunction under stress or pathological conditions.
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Affiliation(s)
- Colline Sanchez
- Université Lyon, Université Claude Bernard Lyon 1, Centre National de la Recherche Scientifique UMR-5310, Institut National de la Santé et de la Recherche Médicale U-1217, Institut NeuroMyoGène, Lyon, France
| | - Christine Berthier
- Université Lyon, Université Claude Bernard Lyon 1, Centre National de la Recherche Scientifique UMR-5310, Institut National de la Santé et de la Recherche Médicale U-1217, Institut NeuroMyoGène, Lyon, France
| | - Yves Tourneur
- Departamento Nutrição, Universidade Federal de Pernambuco, Recife, Brazil
| | - Laloé Monteiro
- Université Lyon, Université Claude Bernard Lyon 1, Centre National de la Recherche Scientifique UMR-5310, Institut National de la Santé et de la Recherche Médicale U-1217, Institut NeuroMyoGène, Lyon, France
| | - Bruno Allard
- Université Lyon, Université Claude Bernard Lyon 1, Centre National de la Recherche Scientifique UMR-5310, Institut National de la Santé et de la Recherche Médicale U-1217, Institut NeuroMyoGène, Lyon, France
| | - Laszlo Csernoch
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Vincent Jacquemond
- Université Lyon, Université Claude Bernard Lyon 1, Centre National de la Recherche Scientifique UMR-5310, Institut National de la Santé et de la Recherche Médicale U-1217, Institut NeuroMyoGène, Lyon, France
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4
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Neuron-derived factors negatively modulate ryanodine receptor-mediated calcium release in cultured mouse astrocytes. Cell Calcium 2020; 92:102304. [PMID: 33065384 DOI: 10.1016/j.ceca.2020.102304] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 10/01/2020] [Accepted: 10/01/2020] [Indexed: 12/22/2022]
Abstract
Changes in intracellular Ca2+ concentration ([Ca2+]i) produced by ryanodine receptor (RyR) agonist, caffeine (caf), and ionotropic agonists: N-methyl-d-aspartate (NMDA) receptor (NMDAR) agonist, NMDA and P2X7 receptor (P2X7R) agonist, 3'-O-(4-benzoyl)benzoyl adenosine 5'-triphosphate (BzATP) were measured in cultured mouse cortical astrocytes loaded with the fluorescent calcium indicator Fluo3-AM in a confocal laser scanning microscope. In mouse astrocytes cultured in standard medium (SM), treatment with caf increased [Ca2+]i, with a peak response occurring about 10 min after stimulus application. Peak responses to NMDA or BzATP were observed about <1 min and 4.5 min post stimulus, respectively. Co-treatment with NMDA or BzATP did not alter the peak response to caf in astrocytes cultured in SM, the absence of the effects being most likely due to asynchrony between the response to caf, NMDA and BzATP. Incubation of astrocytes with neuron-condition medium (NCM) for 24 h totally abolished the caf-evoked [Ca2+]i increase. In NCM-treated astrocytes, peak of [Ca2+]i rise evoked by NMDA was delayed to about 3.5 min, and that induced by BzATP occurred about three minutes earlier than in SM. The results show that neurons secrete factors that negatively modulate RyR-mediated Ca2+-induced Ca2+ release (CICR) in astrocytes and alter the time course of Ca2+ responses to ionotropic stimuli.
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Son YH, Lee SM, Lee SH, Yoon JH, Kang JS, Yang YR, Kwon KS. Comparative molecular analysis of endurance exercise in vivo with electrically stimulated in vitro myotube contraction. J Appl Physiol (1985) 2019; 127:1742-1753. [DOI: 10.1152/japplphysiol.00091.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Exercise has positive effects on health and improves a variety of disease conditions. An in vitro model of exercise has been developed to better understand its molecular mechanisms. While various conditions have been used to mimic in vivo exercise, no specific conditions have matched a specific type of in vivo exercise. Here, we screened various electrical pulse stimulation (EPS) conditions and compared the molecular events under each condition in myotube culture with that obtained under voluntary wheel running (VWR), a mild endurance exercise, in mice. Both EPS and VWR upregulated the mRNA levels of genes involved in the slow-type twitch ( Myh7 and Myh2) and myogenesis ( Myod and Myog) and increased the protein expression of peroxisome proliferator-activated receptor-γ coactivator-1α, which is involved in mitochondrial biogenesis. These changes were accompanied by activation of p38 and AMPK. However, neither condition induced the expression of muscle-specific E3 ligases such as MAFbx and MuRF1. Both EPS and VWR consistently induced antioxidant genes such as Sod3 and Gpx4 but did not cause similar changes in the expression levels of the calcium channel/pump-related genes Ryr and Serca. Furthermore, both EPS and VWR reduced glycogen levels but not lactate levels as assessed in post-EPS culture medium and post-VWR serum, respectively. Thus we identified an in vitro EPS condition that effectively mimics VWR in mice, which can facilitate further studies of the detailed molecular mechanisms of endurance exercise in the absence of interference from multiple tissues and organs. NEW & NOTEWORTHY This study establishes an optimal condition for electrical pulse stimulation (EPS) in myotubes that shows a similar molecular signature as voluntary wheel running. The specific EPS condition 1) upregulates the mRNA of slow-twitch muscle components and myogenic transcription factors, 2) induces antioxidant genes without any muscle damage, and 3) promotes peroxisome proliferator-activated receptor-γ coactivator-1α and its upstream regulators involved in mitochondrial biogenesis.
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Affiliation(s)
- Young Hoon Son
- Aging Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Republic of Korea
| | - Seung-Min Lee
- Aging Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Republic of Korea
| | - Seol Hee Lee
- Aging Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Republic of Korea
- Department of Biomolecular Science, KRIBB School of Bioscience, Korea University of Science and Technology, Daejeon, Republic of Korea
| | - Jong Hyeon Yoon
- Aging Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Republic of Korea
- Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology, Daejeon, Republic of Korea
| | - Jae Sook Kang
- Aging Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Republic of Korea
- Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology, Daejeon, Republic of Korea
| | - Yong Ryoul Yang
- Aging Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Republic of Korea
| | - Ki-Sun Kwon
- Aging Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Republic of Korea
- Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology, Daejeon, Republic of Korea
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Heinz LP, Kopec W, de Groot BL, Fink RHA. In silico assessment of the conduction mechanism of the Ryanodine Receptor 1 reveals previously unknown exit pathways. Sci Rep 2018; 8:6886. [PMID: 29720700 PMCID: PMC5932038 DOI: 10.1038/s41598-018-25061-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 04/13/2018] [Indexed: 12/18/2022] Open
Abstract
The ryanodine receptor 1 is a large calcium ion channel found in mammalian skeletal muscle. The ion channel gained a lot of attention recently, after multiple independent authors published near-atomic cryo electron microscopy data. Taking advantage of the unprecedented quality of structural data, we performed molecular dynamics simulations on the entire ion channel as well as on a reduced model. We calculated potentials of mean force for Ba2+, Ca2+, Mg2+, K+, Na+ and Cl- ions using umbrella sampling to identify the key residues involved in ion permeation. We found two main binding sites for the cations, whereas the channel is strongly repulsive for chloride ions. Furthermore, the data is consistent with the model that the receptor achieves its ion selectivity by over-affinity for divalent cations in a calcium-block-like fashion. We reproduced the experimental conductance for potassium ions in permeation simulations with applied voltage. The analysis of the permeation paths shows that ions exit the pore via multiple pathways, which we suggest to be related to the experimental observation of different subconducting states.
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Affiliation(s)
- Leonard P Heinz
- Medical Biophysics Unit, Medical Faculty, Institute of Physiology and Pathophysiology, Heidelberg University, 69120, Heidelberg, Germany.
- Department of Theoretical and Computational Biophysics, Max Planck Institute for Biophysical Chemistry, 37077, Göttingen, Germany.
| | - Wojciech Kopec
- Computational Biomolecular Dynamics Group, Max Planck Institute for Biophysical Chemistry, 37077, Göttingen, Germany
| | - Bert L de Groot
- Computational Biomolecular Dynamics Group, Max Planck Institute for Biophysical Chemistry, 37077, Göttingen, Germany
| | - Rainer H A Fink
- Medical Biophysics Unit, Medical Faculty, Institute of Physiology and Pathophysiology, Heidelberg University, 69120, Heidelberg, Germany
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Cheng AJ, Willis SJ, Zinner C, Chaillou T, Ivarsson N, Ørtenblad N, Lanner JT, Holmberg HC, Westerblad H. Post-exercise recovery of contractile function and endurance in humans and mice is accelerated by heating and slowed by cooling skeletal muscle. J Physiol 2017; 595:7413-7426. [PMID: 28980321 DOI: 10.1113/jp274870] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 09/20/2017] [Indexed: 12/22/2022] Open
Abstract
KEY POINTS We investigated whether intramuscular temperature affects the acute recovery of exercise performance following fatigue-induced by endurance exercise. Mean power output was better preserved during an all-out arm-cycling exercise following a 2 h recovery period in which the upper arms were warmed to an intramuscular temperature of ̴ 38°C than when they were cooled to as low as 15°C, which suggested that recovery of exercise performance in humans is dependent on muscle temperature. Mechanisms underlying the temperature-dependent effect on recovery were studied in intact single mouse muscle fibres where we found that recovery of submaximal force and restoration of fatigue resistance was worsened by cooling (16-26°C) and improved by heating (36°C). Isolated whole mouse muscle experiments confirmed that cooling impaired muscle glycogen resynthesis. We conclude that skeletal muscle recovery from fatigue-induced by endurance exercise is impaired by cooling and improved by heating, due to changes in glycogen resynthesis rate. ABSTRACT Manipulation of muscle temperature is believed to improve post-exercise recovery, with cooling being especially popular among athletes. However, it is unclear whether such temperature manipulations actually have positive effects. Accordingly, we studied the effect of muscle temperature on the acute recovery of force and fatigue resistance after endurance exercise. One hour of moderate-intensity arm cycling exercise in humans was followed by 2 h recovery in which the upper arms were either heated to 38°C, not treated (33°C), or cooled to ∼15°C. Fatigue resistance after the recovery period was assessed by performing 3 × 5 min sessions of all-out arm cycling at physiological temperature for all conditions (i.e. not heated or cooled). Power output during the all-out exercise was better maintained when muscles were heated during recovery, whereas cooling had the opposite effect. Mechanisms underlying the temperature-dependent effect on recovery were tested in mouse intact single muscle fibres, which were exposed to ∼12 min of glycogen-depleting fatiguing stimulation (350 ms tetani given at 10 s interval until force decreased to 30% of the starting force). Fibres were subsequently exposed to the same fatiguing stimulation protocol after 1-2 h of recovery at 16-36°C. Recovery of submaximal force (30 Hz), the tetanic myoplasmic free [Ca2+ ] (measured with the fluorescent indicator indo-1), and fatigue resistance were all impaired by cooling (16-26°C) and improved by heating (36°C). In addition, glycogen resynthesis was faster at 36°C than 26°C in whole flexor digitorum brevis muscles. We conclude that recovery from exhaustive endurance exercise is accelerated by raising and slowed by lowering muscle temperature.
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Affiliation(s)
| | - Sarah J Willis
- Swedish Winter Sports Research Centre, Mid Sweden University, Östersund, Sweden
| | - Christoph Zinner
- Swedish Winter Sports Research Centre, Mid Sweden University, Östersund, Sweden
| | - Thomas Chaillou
- Karolinska Institutet, Stockholm, Sweden.,Örebro Universitet, Örebro, Sweden
| | | | | | | | - Hans-Christer Holmberg
- Karolinska Institutet, Stockholm, Sweden.,Swedish Winter Sports Research Centre, Mid Sweden University, Östersund, Sweden
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8
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Mak DOD, Foskett JK. Ryanodine receptor resolution revolution: Implications for InsP 3 receptors? Cell Calcium 2016; 61:53-56. [PMID: 27836217 DOI: 10.1016/j.ceca.2016.11.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 11/03/2016] [Indexed: 10/20/2022]
Affiliation(s)
- Don-On Daniel Mak
- Departments of Physiology, Perelman School of Medicine University of Pennsylvania Philadelphia, PA 19104-6085, United States.
| | - J Kevin Foskett
- Departments of Physiology, Perelman School of Medicine University of Pennsylvania Philadelphia, PA 19104-6085, United States; Cell and Developmental Biology, Perelman School of Medicine University of Pennsylvania Philadelphia, PA 19104-6085, United States.
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Ruiz-Hurtado G, Li L, Fernández-Velasco M, Rueda A, Lefebvre F, Wang Y, Mateo P, Cassan C, Gellen B, Benitah JP, Gómez AM. Reconciling depressed Ca2+ sparks occurrence with enhanced RyR2 activity in failing mice cardiomyocytes. ACTA ACUST UNITED AC 2015; 146:295-306. [PMID: 26371209 PMCID: PMC4586588 DOI: 10.1085/jgp.201511366] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Accepted: 08/19/2015] [Indexed: 12/18/2022]
Abstract
Abnormalities in cardiomyocyte Ca2+ handling contribute to impaired contractile function in heart failure (HF). Experiments on single ryanodine receptors (RyRs) incorporated into lipid bilayers have indicated that RyRs from failing hearts are more active than those from healthy hearts. Here, we analyzed spontaneous Ca2+ sparks (brief, localized increased in [Ca2+]i) to evaluate RyR cluster activity in situ in a mouse post-myocardial infarction (PMI) model of HF. The cardiac ejection fraction of PMI mice was reduced to ∼30% of that of sham-operated (sham) mice, and their cardiomyocytes were hypertrophied. The [Ca2+]i transient amplitude and sarcoplasmic reticulum (SR) Ca2+ load were decreased in intact PMI cardiomyocytes compared with those from sham mice, and spontaneous Ca2+ sparks were less frequent, whereas the fractional release and the frequency of Ca2+ waves were both increased, suggesting higher RyR activity. In permeabilized cardiomyocytes, in which the internal solution can be controlled, Ca2+ sparks were more frequent in PMI cells (under conditions of similar SR Ca2+ load), confirming the enhanced RyR activity. However, in intact cells from PMI mice, the Ca2+ sparks frequency normalized by the SR Ca2+ load in that cell were reduced compared with those in sham mice, indicating that the cytosolic environment in intact cells contributes to the decrease in Ca2+ spark frequency. Indeed, using an internal "failing solution" with less ATP (as found in HF), we observed a dramatic decrease in Ca2+ spark frequency in permeabilized PMI and sham myocytes. In conclusion, our data show that, even if isolated RyR channels show more activity in HF, concomitant alterations in intracellular media composition and SR Ca2+ load may mask these effects at the Ca2+ spark level in intact cells. Nonetheless, in this scenario, the probability of arrhythmogenic Ca2+ waves is enhanced, and they play a potential role in the increase in arrhythmia events in HF patients.
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Affiliation(s)
- Gema Ruiz-Hurtado
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR-S 1180, LabEx LERMIT, DHU TORINO, and Faculté de Pharmacie, Université Paris Sud, Université Paris-Saclay, 92296 Châtenay-Malabry, France Institut National de la Santé et de la Recherche Médicale (INSERM), UMR-S 1180, LabEx LERMIT, DHU TORINO, and Faculté de Pharmacie, Université Paris Sud, Université Paris-Saclay, 92296 Châtenay-Malabry, France Instituto de Investigación, Hospital 12 de Octubre, 28041 Madrid, Spain
| | - Linwei Li
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR-S 1180, LabEx LERMIT, DHU TORINO, and Faculté de Pharmacie, Université Paris Sud, Université Paris-Saclay, 92296 Châtenay-Malabry, France Institut National de la Santé et de la Recherche Médicale (INSERM), UMR-S 1180, LabEx LERMIT, DHU TORINO, and Faculté de Pharmacie, Université Paris Sud, Université Paris-Saclay, 92296 Châtenay-Malabry, France
| | | | - Angélica Rueda
- Departamento de Bioquímica, Centro de Investigación y de Estudios Avanzados del IPN, 07360 México City, D.F., México
| | - Florence Lefebvre
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR-S 1180, LabEx LERMIT, DHU TORINO, and Faculté de Pharmacie, Université Paris Sud, Université Paris-Saclay, 92296 Châtenay-Malabry, France Institut National de la Santé et de la Recherche Médicale (INSERM), UMR-S 1180, LabEx LERMIT, DHU TORINO, and Faculté de Pharmacie, Université Paris Sud, Université Paris-Saclay, 92296 Châtenay-Malabry, France
| | - Yueyi Wang
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR-S 1180, LabEx LERMIT, DHU TORINO, and Faculté de Pharmacie, Université Paris Sud, Université Paris-Saclay, 92296 Châtenay-Malabry, France Institut National de la Santé et de la Recherche Médicale (INSERM), UMR-S 1180, LabEx LERMIT, DHU TORINO, and Faculté de Pharmacie, Université Paris Sud, Université Paris-Saclay, 92296 Châtenay-Malabry, France
| | - Philippe Mateo
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR-S 1180, LabEx LERMIT, DHU TORINO, and Faculté de Pharmacie, Université Paris Sud, Université Paris-Saclay, 92296 Châtenay-Malabry, France Institut National de la Santé et de la Recherche Médicale (INSERM), UMR-S 1180, LabEx LERMIT, DHU TORINO, and Faculté de Pharmacie, Université Paris Sud, Université Paris-Saclay, 92296 Châtenay-Malabry, France
| | - Cécile Cassan
- Maladies infectieuses et vecteurs: écologie, génétique, évolution et contrôle, Institut de recherche pour le développement, 34394 Montpellier, France
| | - Barnabas Gellen
- INSERM U955 and Department of Cardiology, AP-HP, Henri Mondor Hospital, Université Paris-Est Créteil, 94010 Créteil, France INSERM U955 and Department of Cardiology, AP-HP, Henri Mondor Hospital, Université Paris-Est Créteil, 94010 Créteil, France
| | - Jean Pierre Benitah
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR-S 1180, LabEx LERMIT, DHU TORINO, and Faculté de Pharmacie, Université Paris Sud, Université Paris-Saclay, 92296 Châtenay-Malabry, France Institut National de la Santé et de la Recherche Médicale (INSERM), UMR-S 1180, LabEx LERMIT, DHU TORINO, and Faculté de Pharmacie, Université Paris Sud, Université Paris-Saclay, 92296 Châtenay-Malabry, France
| | - Ana María Gómez
- Institut National de la Santé et de la Recherche Médicale (INSERM), UMR-S 1180, LabEx LERMIT, DHU TORINO, and Faculté de Pharmacie, Université Paris Sud, Université Paris-Saclay, 92296 Châtenay-Malabry, France Institut National de la Santé et de la Recherche Médicale (INSERM), UMR-S 1180, LabEx LERMIT, DHU TORINO, and Faculté de Pharmacie, Université Paris Sud, Université Paris-Saclay, 92296 Châtenay-Malabry, France
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10
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Solzbach U, Kitterer HR, Haas H. Reversible congestive heart failure in severe hypocalcemia. Herz 2010; 35:507-10. [DOI: 10.1007/s00059-010-3374-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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11
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Kampfer AJ, Balog EM. S-Adenosyl-l-methionine Regulation of the Cardiac Ryanodine Receptor Involves Multiple Mechanisms. Biochemistry 2010; 49:7600-14. [DOI: 10.1021/bi100599b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Angela J. Kampfer
- School of Applied Physiology, Georgia Institute of Technology, Atlanta, Georgia 30332
| | - Edward M. Balog
- School of Applied Physiology, Georgia Institute of Technology, Atlanta, Georgia 30332
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12
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Kornyeyev D, Reyes M, Escobar AL. Luminal Ca(2+) content regulates intracellular Ca(2+) release in subepicardial myocytes of intact beating mouse hearts: effect of exogenous buffers. Am J Physiol Heart Circ Physiol 2010; 298:H2138-53. [PMID: 20382849 DOI: 10.1152/ajpheart.00885.2009] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ca(+)-induced Ca(2+) release tightly controls the function of ventricular cardiac myocytes under normal and pathological conditions. Two major factors contributing to the regulation of Ca(2+) release are the cytosolic free Ca(2+) concentration and sarcoplasmic reticulum (SR) Ca(2+) content. We hypothesized that the amount of Ca(2+) released from the SR during each heart beat strongly defines the refractoriness of Ca(2+) release. To test this hypothesis, EGTA AM, a high-affinity, slow-association rate Ca(2+) chelator, was used as a tool to modify luminal SR Ca(2+) content. An analysis of the cytosolic and luminal SR Ca(2+) dynamics recorded from the epicardial layer of intact mouse hearts indicated that the presence of EGTA reduced the diastolic SR free Ca(2+) concentration and fraction of SR Ca(2+) depletion during each beat. In addition, this maneuver shortened the refractory period and accelerated the restitution of Ca(2+) release. As a consequence of the accelerated restitution, the frequency dependence of Ca(2+) alternans was significantly shifted toward higher heart rates, suggesting a role of luminal SR Ca(2+) in the genesis of this highly arrhythmogenic phenomenon. Thus, intra-SR Ca(2+) dynamics set the refractoriness and frequency dependence of Ca(2+) transients in subepicardial ventricular myocytes.
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Affiliation(s)
- Dmytro Kornyeyev
- School of Engineering, Univ. of California-Merced, 5200 N. Lake Rd., Merced, CA 95343, USA
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13
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Gerwin RD. The Taut Band and Other Mysteries of the Trigger Point: An Examination of the Mechanisms Relevant to the Development and Maintenance of the Trigger Point. ACTA ACUST UNITED AC 2009. [DOI: 10.1080/10582450801960081] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Khait L, Birla RK. Changes in gene expression during the formation of bioengineered heart muscle. Artif Organs 2009; 33:3-15. [PMID: 19178436 DOI: 10.1111/j.1525-1594.2008.00669.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A three-dimensional bioengineered heart muscle (BEHM) construct model had been previously developed, exhibiting contractile forces up to 800 microN. The interest of this study was to determine gene expression levels of biologic markers involved in calcium-handling between BEHM, cell monolayer, and neonatal heart. Cardiac cells were isolated from one litter of F344 rats and organized into groups (n = 5): 4-, 7-, 10-day BEHM and cell monolayer; BEHM was evaluated for cell viability and contractility. Groups were then analyzed for mRNA expression of calcium-handling proteins: myosin heavy chain (MHC) alpha and beta, Sarcoplasmic reticulum Ca++ ATPase (SERCA) 2, phospholamban (PBL), and ryanodine receptor. BEHM exhibited electrically stimulated active force (208 +/- 12 microN day 4, 361 +/- 22 microN day 7, and 344 +/- 29 microN day 10) and no decrease in cell number. Real-time polymerase chain reaction (PCR) showed an increase in gene expression of all calcium-handling proteins in BEHM at 7 and 10 days compared with monolayers, for example, comparing BEHM to monolayer (7 and 10 days, respectively), MHC-alpha: 2600-fold increase and a 100-fold increase; MHC-beta: 70-fold increase at 10 days; ryanodine receptor: 74-fold increase at 10 days; SERCA: 19-fold increase and sixfold increase; PBL: 158-fold increase and 24-fold increase. It was concluded that a three-dimensional environment is a better culturing condition of cardiac cells than a monolayer. Also, BEHM constructs demonstrated a high similarity to a native myocardium, and is, thus, a good starting foundation for engineered heart muscle.
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Affiliation(s)
- Luda Khait
- Section of Cardiac Surgery, University of Michigan, Ann Arbor, MI, USA
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Wang J, Jiang L, Gao X, Ding H, Wang Q, Cheng J, Gao R, Xiao H. Fenvalerate-induced Ca2+ transients via both intracellular and extracellular way in mouse GC-2spd (ts) cells. Toxicology 2009; 259:122-32. [DOI: 10.1016/j.tox.2009.02.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2008] [Revised: 02/19/2009] [Accepted: 02/19/2009] [Indexed: 11/28/2022]
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Time course of changes in in vitro sarcoplasmic reticulum Ca2+-handling and Na+-K+-ATPase activity during repetitive contractions. Pflugers Arch 2008; 456:601-9. [DOI: 10.1007/s00424-007-0427-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2007] [Revised: 10/22/2007] [Accepted: 12/10/2007] [Indexed: 11/26/2022]
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Laver DR. Ca2+ stores regulate ryanodine receptor Ca2+ release channels via luminal and cytosolic Ca2+ sites. Clin Exp Pharmacol Physiol 2007; 34:889-96. [PMID: 17645636 DOI: 10.1111/j.1440-1681.2007.04708.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
1. In muscle, intracellular calcium concentration, hence skeletal muscle force and cardiac output, is regulated by uptake and release of calcium from the sarcoplasmic reticulum. The ryanodine receptor (RyR) forms the calcium release channel in the sarcoplasmic reticulum. 2. The free [Ca2+] in the sarcoplasmic reticulum regulates the excitability of this store by stimulating the Ca2+ release channels in its membrane. This process involves Ca2+-sensing mechanisms on both the luminal and cytoplasmic sides of the RyR. In the cardiac RyR, these have been shown to be a luminal Ca2+ activation site (L-site; 60 micromol/L affinity), a cytoplasmic activation site (A-site; 0.9 micromol/L affinity) and a cytoplasmic Ca2+ inactivation site (I2-site; 1.2 micromol/L affinity). 3. Cardiac RyR activation by luminal Ca2+ occurs by a multistep process dubbed 'luminal-triggered Ca2+ feed-through'. Binding of Ca2+ to the L-site initiates brief (1 msec) openings at a rate of up to 10/s. Once the pore is open, luminal Ca2+ has access to the A-site (producing up to 30-fold prolongation of openings) and to the I2-site (causing inactivation at high levels of Ca2+ feed-through). 4. The present paper reviews the evidence for the principal aspects of the 'luminal-triggered Ca2+ feed-through' model, the properties of the various Ca2+-dependent gating mechanisms and their likely role in controlling sarcoplasmic reticulum (SR) Ca2+ release in cardiac muscle. 5. The model makes the following important predictions: (i) there will be a close link between luminal and cytoplasmic regulation of RyRs and any cofactor that prolongs channel openings triggered by cytoplasmic Ca2+ will also promote RyR activation by luminal Ca2+; (ii) luminal Mg2+ (1 mmol/L) is essential for the control of SR excitability in cardiac muscle by luminal Ca2+; and (iii) the different RyR isoforms in skeletal and cardiac muscle will be controlled quite differently by the luminal milieu. For example, Mg2+ in the SR lumen (approximately 1 mmol/L) can strongly inhibit RyR2 by competing with Ca2+ for the L-site, whereas RyR1 is not affected by luminal Mg2+.
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Affiliation(s)
- Derek R Laver
- School of Biomedical Sciences, University of Newcastle and Hunter Medical Research Institute, Callaghan, New South Wales, Australia.
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Laver DR. Ca2+ stores regulate ryanodine receptor Ca2+ release channels via luminal and cytosolic Ca2+ sites. Biophys J 2007; 92:3541-55. [PMID: 17351009 PMCID: PMC1853142 DOI: 10.1529/biophysj.106.099028] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The free [Ca2+] in endoplasmic/sarcoplasmic reticulum Ca2+ stores regulates excitability of Ca2+ release by stimulating the Ca2+ release channels. Just how the stored Ca2+ regulates activation of these channels is still disputed. One proposal attributes luminal Ca2+-activation to luminal facing regulatory sites, whereas another envisages Ca2+ permeation to cytoplasmic sites. This study develops a unified model for luminal Ca2+ activation for single cardiac ryanodine receptors (RyR2) and RyRs in coupled clusters in artificial lipid bilayers. It is shown that luminal regulation of RyR2 involves three modes of action associated with Ca2+ sensors in different parts of the molecule; a luminal activation site (L-site, 60 microM affinity), a cytoplasmic activation site (A-site, 0.9 microM affinity), and a novel cytoplasmic inactivation site (I2-site, 1.2 microM affinity). RyR activation by luminal Ca2+ is demonstrated to occur by a multistep process dubbed luminal-triggered Ca2+ feedthrough. Ca2+ binding to the L-site initiates brief openings (1 ms duration at 1-10 s(-1)) allowing luminal Ca2+ to access the A-site, producing up to 30-fold prolongation of openings. The model explains a broad data set, reconciles previous conflicting observations and provides a foundation for understanding the action of pharmacological agents, RyR-associated proteins, and RyR2 mutations on a range of Ca2+-mediated physiological and pathological processes.
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Affiliation(s)
- Derek R Laver
- School of Biomedical Sciences, University of Newcastle and Hunter Medical Research Institute, Callaghan, New South Wales, Australia.
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