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Dries E, Gilbert G, Roderick HL, Sipido KR. The ryanodine receptor microdomain in cardiomyocytes. Cell Calcium 2023; 114:102769. [PMID: 37390591 DOI: 10.1016/j.ceca.2023.102769] [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: 05/02/2023] [Revised: 06/11/2023] [Accepted: 06/12/2023] [Indexed: 07/02/2023]
Abstract
The ryanodine receptor type 2 (RyR) is a key player in Ca2+ handling during excitation-contraction coupling. During each heartbeat, RyR channels are responsible for linking the action potential with the contractile machinery of the cardiomyocyte by releasing Ca2+ from the sarcoplasmic reticulum. RyR function is fine-tuned by associated signalling molecules, arrangement in clusters and subcellular localization. These parameters together define RyR function within microdomains and are subject to disease remodelling. This review describes the latest findings on RyR microdomain organization, the alterations with disease which result in increased subcellular heterogeneity and emergence of microdomains with enhanced arrhythmogenic potential, and presents novel technologies that guide future research to study and target RyR channels within specific microdomains.
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Affiliation(s)
- Eef Dries
- Lab of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium.
| | - Guillaume Gilbert
- Lab of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium; Laboratoire ORPHY EA 4324, Université de Brest, Brest, France
| | - H Llewelyn Roderick
- Lab of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Karin R Sipido
- Lab of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
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2
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Hadiatullah H, He Z, Yuchi Z. Structural Insight Into Ryanodine Receptor Channelopathies. Front Pharmacol 2022; 13:897494. [PMID: 35677449 PMCID: PMC9168041 DOI: 10.3389/fphar.2022.897494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 05/09/2022] [Indexed: 11/28/2022] Open
Abstract
The ryanodine receptors (RyRs) are large cation-selective ligand-gated channels that are expressed in the sarcoplasmic reticulum (SR) membrane. They mediate the controlled release of Ca2+ from SR and play an important role in many cellular processes. The mutations in RyRs are associated with several skeletal muscle and cardiac conditions, including malignant hyperthermia (MH), central core disease (CCD), catecholaminergic polymorphic ventricular tachycardia (CPVT), and arrhythmogenic right ventricular dysplasia (ARVD). Recent breakthroughs in structural biology including cryo-electron microscopy (EM) and X-ray crystallography allowed the determination of a number of near-atomic structures of RyRs, including wildtype and mutant structures as well as the structures in complex with different modulating molecules. This allows us to comprehend the physiological gating and regulatory mechanisms of RyRs and the underlying pathological mechanisms of the disease-causing mutations. In this review, based on the insights gained from the available high-resolution structures of RyRs, we address several questions: 1) what are the gating mechanisms of different RyR isoforms; 2) how RyRs are regulated by multiple channel modulators, including ions, small molecules, and regulatory proteins; 3) how do disease-causing mutations affect the structure and function of RyRs; 4) how can these structural information aid in the diagnosis of the related diseases and the development of pharmacological therapies.
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Affiliation(s)
- Hadiatullah Hadiatullah
- Tianjin Key Laboratory for Modern Drug Delivery and High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, China
- Department of Molecular Pharmacology, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China
| | - Zhao He
- Tianjin Key Laboratory for Modern Drug Delivery and High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, China
- Department of Molecular Pharmacology, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China
| | - Zhiguang Yuchi
- Tianjin Key Laboratory for Modern Drug Delivery and High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, China
- Department of Molecular Pharmacology, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China
- *Correspondence: Zhiguang Yuchi,
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3
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H2O2/Ca2+/Zn2+ Complex Can Be Considered a “Collaborative Sensor” of the Mitochondrial Capacity? Antioxidants (Basel) 2022; 11:antiox11020342. [PMID: 35204224 PMCID: PMC8868167 DOI: 10.3390/antiox11020342] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/03/2022] [Accepted: 02/05/2022] [Indexed: 02/04/2023] Open
Abstract
In order to maintain a state of well-being, the cell needs a functional control center that allows it to respond to changes in the internal and surrounding environments and, at the same time, carry out the necessary metabolic functions. In this review, we identify the mitochondrion as such an “agora”, in which three main messengers are able to collaborate and activate adaptive response mechanisms. Such response generators, which we have identified as H2O2, Ca2+, and Zn2+, are capable of “reading” the environment and talking to each other in cooperation with the mitochondrion. In this manner, these messengers exchange information and generate a holistic response of the whole cell, dependent on its functional state. In this review, to corroborate this claim, we analyzed the role these actors, which in the review we call “sensors”, play in the regulation of skeletal muscle contractile capacities chosen as a model of crosstalk between Ca2+, Zn2+, and H2O2.
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Val‐Blasco A, Gil‐Fernández M, Rueda A, Pereira L, Delgado C, Smani T, Ruiz Hurtado G, Fernández‐Velasco M. Ca 2+ mishandling in heart failure: Potential targets. Acta Physiol (Oxf) 2021; 232:e13691. [PMID: 34022101 DOI: 10.1111/apha.13691] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 05/17/2021] [Accepted: 05/19/2021] [Indexed: 12/14/2022]
Abstract
Ca2+ mishandling is a common feature in several cardiovascular diseases such as heart failure (HF). In many cases, impairment of key players in intracellular Ca2+ homeostasis has been identified as the underlying mechanism of cardiac dysfunction and cardiac arrhythmias associated with HF. In this review, we summarize primary novel findings related to Ca2+ mishandling in HF progression. HF research has increasingly focused on the identification of new targets and the contribution of their role in Ca2+ handling to the progression of the disease. Recent research studies have identified potential targets in three major emerging areas implicated in regulation of Ca2+ handling: the innate immune system, bone metabolism factors and post-translational modification of key proteins involved in regulation of Ca2+ handling. Here, we describe their possible contributions to the progression of HF.
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Affiliation(s)
| | | | - Angélica Rueda
- Department of Biochemistry Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV‐IPN) México City Mexico
| | - Laetitia Pereira
- INSERM UMR‐S 1180 Laboratory of Ca Signaling and Cardiovascular Physiopathology University Paris‐Saclay Châtenay‐Malabry France
| | - Carmen Delgado
- Instituto de Investigaciones Biomédicas Alberto Sols Madrid Spain
- Department of Metabolism and Cell Signalling Biomedical Research Institute "Alberto Sols" CSIC‐UAM Madrid Spain
| | - Tarik Smani
- Centro de Investigación Biomédica en Red en Enfermedades Cardiovasculares (CIBERCV) Madrid Spain
- Department of Medical Physiology and Biophysics University of Seville Seville Spain
- Group of Cardiovascular Pathophysiology Institute of Biomedicine of Seville University Hospital of Virgen del Rocío, University of Seville, CSIC Seville Spain
| | - Gema Ruiz Hurtado
- Cardiorenal Translational Laboratory Institute of Research i+12 University Hospital 12 de Octubre Madrid Spain
- CIBER‐CV University Hospita1 12 de Octubre Madrid Spain
| | - Maria Fernández‐Velasco
- La Paz University Hospital Health Research Institute IdiPAZ Madrid Spain
- Centro de Investigación Biomédica en Red en Enfermedades Cardiovasculares (CIBERCV) Madrid Spain
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5
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Wang L, Ginnan RG, Wang YX, Zheng YM. Interactive Roles of CaMKII/Ryanodine Receptor Signaling and Inflammation in Lung Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1303:305-317. [PMID: 33788199 DOI: 10.1007/978-3-030-63046-1_16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Ca2+/calmodulin-dependent protein kinase II (CaMKII) is a multifunctional protein kinase and has been recently recognized to play a vital role in pathological events in the pulmonary system. CaMKII has diverse downstream targets that promote vascular disease, asthma, and cancer, so improved understanding of CaMKII signaling has the potential to lead to new therapies for lung diseases. Multiple studies have demonstrated that CaMKII is involved in redox modulation of ryanodine receptors (RyRs). CaMKII can be directly activated by reactive oxygen species (ROS) which then regulates RyR activity, which is essential for Ca2+-dependent processes in lung diseases. Furthermore, both CaMKII and RyRs participate in the inflammation process. However, their role in the pulmonary physiology in response to ROS is still an ambiguous one. Because CaMKII and RyRs are important in pulmonary biology, cell survival, cell cycle control, and inflammation, it is possible that the relationship between ROS and CaMKII/RyRs signal complex will be necessary for understanding and treating lung diseases. Here, we review roles of CaMKII/RyRs in lung diseases to understand with how CaMKII/RyRs may act as a transduction signal to connect prooxidant conditions into specific downstream pathological effects that are relevant to rare and common forms of pulmonary disease.
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Affiliation(s)
- Lan Wang
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA.,Department of Cardio-Pulmonary Circulation, Shanghai Pulmonary Hospital, Tongji University, Shanghai, China
| | - Roman G Ginnan
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA
| | - Yong-Xiao Wang
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA.
| | - Yun-Min Zheng
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY, USA.
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6
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Nikolaienko R, Bovo E, Zima AV. Redox Dependent Modifications of Ryanodine Receptor: Basic Mechanisms and Implications in Heart Diseases. Front Physiol 2018; 9:1775. [PMID: 30574097 PMCID: PMC6291498 DOI: 10.3389/fphys.2018.01775] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 11/23/2018] [Indexed: 12/12/2022] Open
Abstract
Heart contraction vitally depends on tightly controlled intracellular Ca regulation. Because contraction is mainly driven by Ca released from the sarcoplasmic reticulum (SR), this organelle plays a particularly important role in Ca regulation. The type two ryanodine receptor (RyR2) is the major SR Ca release channel in ventricular myocytes. Several cardiac pathologies, including myocardial infarction and heart failure, are associated with increased RyR2 activity and diastolic SR Ca leak. It has been suggested that the increased RyR2 activity plays an important role in arrhythmias and contractile dysfunction. Several studies have linked increased SR Ca leak during myocardial infarction and heart failure to the activation of RyR2 in response to oxidative stress. This activation might include direct oxidation of RyR2 as well as indirect activation via phosphorylation or altered interactions with regulatory proteins. Out of ninety cysteine residues per RyR2 subunit, twenty one were reported to be in reduced state that could be potential targets for redox modifications that include S-nitrosylation, S-glutathionylation, and disulfide cross-linking. Despite its clinical significance, molecular mechanisms of RyR dysfunction during oxidative stress are not fully understood. Herein we review the most recent insights into redox-dependent modulation of RyR2 during oxidative stress and heart diseases.
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Affiliation(s)
- Roman Nikolaienko
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL, United States
| | - Elisa Bovo
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL, United States
| | - Aleksey V Zima
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL, United States
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7
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Hamilton S, Terentyev D. Proarrhythmic Remodeling of Calcium Homeostasis in Cardiac Disease; Implications for Diabetes and Obesity. Front Physiol 2018. [PMID: 30425651 DOI: 10.3389/fphys.2018.01517, 10.3389/fpls.2018.01517] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A rapid growth in the incidence of diabetes and obesity has transpired to a major heath issue and economic burden in the postindustrial world, with more than 29 million patients affected in the United States alone. Cardiovascular defects have been established as the leading cause of mortality and morbidity of diabetic patients. Over the last decade, significant progress has been made in delineating mechanisms responsible for the diminished cardiac contractile function and enhanced propensity for malignant cardiac arrhythmias characteristic of diabetic disease. Rhythmic cardiac contractility relies upon the precise interplay between several cellular Ca2+ transport protein complexes including plasmalemmal L-type Ca2+ channels (LTCC), Na+-Ca2+ exchanger (NCX1), Sarco/endoplasmic Reticulum (SR) Ca2+-ATPase (SERCa2a) and ryanodine receptors (RyR2s), the SR Ca2+ release channels. Here we provide an overview of changes in Ca2+ homeostasis in diabetic ventricular myocytes and discuss the therapeutic potential of targeting Ca2+ handling proteins in the prevention of diabetes-associated cardiomyopathy and arrhythmogenesis.
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Affiliation(s)
- Shanna Hamilton
- Department of Medicine, The Warren Alpert Medical School of Brown University, Providence, RI, United States.,Cardiovascular Research Center, Rhode Island Hospital, Providence, RI, United States
| | - Dmitry Terentyev
- Department of Medicine, The Warren Alpert Medical School of Brown University, Providence, RI, United States.,Cardiovascular Research Center, Rhode Island Hospital, Providence, RI, United States
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Hamilton S, Terentyev D. Proarrhythmic Remodeling of Calcium Homeostasis in Cardiac Disease; Implications for Diabetes and Obesity. Front Physiol 2018; 9:1517. [PMID: 30425651 PMCID: PMC6218530 DOI: 10.3389/fphys.2018.01517] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 10/09/2018] [Indexed: 12/28/2022] Open
Abstract
A rapid growth in the incidence of diabetes and obesity has transpired to a major heath issue and economic burden in the postindustrial world, with more than 29 million patients affected in the United States alone. Cardiovascular defects have been established as the leading cause of mortality and morbidity of diabetic patients. Over the last decade, significant progress has been made in delineating mechanisms responsible for the diminished cardiac contractile function and enhanced propensity for malignant cardiac arrhythmias characteristic of diabetic disease. Rhythmic cardiac contractility relies upon the precise interplay between several cellular Ca2+ transport protein complexes including plasmalemmal L-type Ca2+ channels (LTCC), Na+-Ca2+ exchanger (NCX1), Sarco/endoplasmic Reticulum (SR) Ca2+-ATPase (SERCa2a) and ryanodine receptors (RyR2s), the SR Ca2+ release channels. Here we provide an overview of changes in Ca2+ homeostasis in diabetic ventricular myocytes and discuss the therapeutic potential of targeting Ca2+ handling proteins in the prevention of diabetes-associated cardiomyopathy and arrhythmogenesis.
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Affiliation(s)
- Shanna Hamilton
- Department of Medicine, The Warren Alpert Medical School of Brown University, Providence, RI, United States.,Cardiovascular Research Center, Rhode Island Hospital, Providence, RI, United States
| | - Dmitry Terentyev
- Department of Medicine, The Warren Alpert Medical School of Brown University, Providence, RI, United States.,Cardiovascular Research Center, Rhode Island Hospital, Providence, RI, United States
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9
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Vellecco V, Armogida C, Bucci M. Hydrogen sulfide pathway and skeletal muscle: an introductory review. Br J Pharmacol 2018; 175:3090-3099. [PMID: 29767441 PMCID: PMC6031874 DOI: 10.1111/bph.14358] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 04/18/2018] [Accepted: 04/30/2018] [Indexed: 12/13/2022] Open
Abstract
The presence of the H2 S pathway in skeletal muscle (SKM) has recently been established. SKM expresses the three constitutive H2 S-generating enzymes in animals and humans, and it actively produces H2 S. The main, recognized molecular targets of H2 S, that is, potassium channels and PDEs, have been evaluated in SKM physiology in order to hypothesize a role for H2 S signalling. SKM dysfunctions, including muscular dystrophy and malignant hyperthermia, have also been evaluated as conditions in which the H2 S and transsulfuration pathways have been suggested to be involved. The intrinsic complexity of the molecular mechanisms involved in excitation-contraction (E-C) coupling together with the scarcity of preclinical models of SKM-related disorders have hampered any advances in the knowledge of SKM function. Here, we have addressed the role of the H2 S pathway in E-C coupling and the relative importance of cystathionine β-synthase, cistathionine γ-lyase and 3-mercaptopyruvate sulfurtransferase in SKM diseases.
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Affiliation(s)
- Valentina Vellecco
- Department of Pharmacy, School of Medicine, University of Naples 'Federico II', Naples, 80131, Italy
| | - Chiara Armogida
- Department of Pharmacy, School of Medicine, University of Naples 'Federico II', Naples, 80131, Italy
| | - Mariarosaria Bucci
- Department of Pharmacy, School of Medicine, University of Naples 'Federico II', Naples, 80131, Italy
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10
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Tykocki NR, Boerman EM, Jackson WF. Smooth Muscle Ion Channels and Regulation of Vascular Tone in Resistance Arteries and Arterioles. Compr Physiol 2017; 7:485-581. [PMID: 28333380 DOI: 10.1002/cphy.c160011] [Citation(s) in RCA: 212] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Vascular tone of resistance arteries and arterioles determines peripheral vascular resistance, contributing to the regulation of blood pressure and blood flow to, and within the body's tissues and organs. Ion channels in the plasma membrane and endoplasmic reticulum of vascular smooth muscle cells (SMCs) in these blood vessels importantly contribute to the regulation of intracellular Ca2+ concentration, the primary determinant of SMC contractile activity and vascular tone. Ion channels provide the main source of activator Ca2+ that determines vascular tone, and strongly contribute to setting and regulating membrane potential, which, in turn, regulates the open-state-probability of voltage gated Ca2+ channels (VGCCs), the primary source of Ca2+ in resistance artery and arteriolar SMCs. Ion channel function is also modulated by vasoconstrictors and vasodilators, contributing to all aspects of the regulation of vascular tone. This review will focus on the physiology of VGCCs, voltage-gated K+ (KV) channels, large-conductance Ca2+-activated K+ (BKCa) channels, strong-inward-rectifier K+ (KIR) channels, ATP-sensitive K+ (KATP) channels, ryanodine receptors (RyRs), inositol 1,4,5-trisphosphate receptors (IP3Rs), and a variety of transient receptor potential (TRP) channels that contribute to pressure-induced myogenic tone in resistance arteries and arterioles, the modulation of the function of these ion channels by vasoconstrictors and vasodilators, their role in the functional regulation of tissue blood flow and their dysfunction in diseases such as hypertension, obesity, and diabetes. © 2017 American Physiological Society. Compr Physiol 7:485-581, 2017.
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Affiliation(s)
- Nathan R Tykocki
- Department of Pharmacology, University of Vermont, Burlington, Vermont, USA
| | - Erika M Boerman
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri, USA
| | - William F Jackson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan, USA
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Dulhunty AF, Board PG, Beard NA, Casarotto MG. Physiology and Pharmacology of Ryanodine Receptor Calcium Release Channels. ADVANCES IN PHARMACOLOGY 2017; 79:287-324. [DOI: 10.1016/bs.apha.2016.12.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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12
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Judenherc-Haouzi A, Zhang XQ, Sonobe T, Song J, Rannals MD, Wang J, Tubbs N, Cheung JY, Haouzi P. Methylene blue counteracts H2S toxicity-induced cardiac depression by restoring L-type Ca channel activity. Am J Physiol Regul Integr Comp Physiol 2016; 310:R1030-44. [PMID: 26962024 DOI: 10.1152/ajpregu.00527.2015] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 03/08/2016] [Indexed: 11/22/2022]
Abstract
We have previously reported that methylene blue (MB) can counteract hydrogen sulfide (H2S) intoxication-induced circulatory failure. Because of the multifarious effects of high concentrations of H2S on cardiac function, as well as the numerous properties of MB, the nature of this interaction, if any, remains uncertain. The aim of this study was to clarify 1) the effects of MB on H2S-induced cardiac toxicity and 2) whether L-type Ca(2+) channels, one of the targets of H2S, could transduce some of the counteracting effects of MB. In sedated rats, H2S infused at a rate that would be lethal within 5 min (24 μM·kg(-1)·min(-1)), produced a rapid fall in left ventricle ejection fraction, determined by echocardiography, leading to a pulseless electrical activity. Blood concentrations of gaseous H2S reached 7.09 ± 3.53 μM when cardiac contractility started to decrease. Two to three injections of MB (4 mg/kg) transiently restored cardiac contractility, blood pressure, and V̇o2, allowing the animals to stay alive until the end of H2S infusion. MB also delayed PEA by several minutes following H2S-induced coma and shock in unsedated rats. Applying a solution containing lethal levels of H2S (100 μM) on isolated mouse cardiomyocytes significantly reduced cell contractility, intracellular calcium concentration ([Ca(2+)]i) transient amplitudes, and L-type Ca(2+) currents (ICa) within 3 min of exposure. MB (20 mg/l) restored the cardiomyocyte function, ([Ca(2+)]i) transient, and ICa The present results offer a new approach for counteracting H2S toxicity and potentially other conditions associated with acute inhibition of L-type Ca(2+) channels.
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Affiliation(s)
- Annick Judenherc-Haouzi
- Heart and Vascular Institute, Pennsylvania State University, College of Medicine, Hershey, Pennsylvania;
| | - Xue-Qian Zhang
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania; and
| | - Takashi Sonobe
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - Jianliang Song
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania; and
| | - Matthew D Rannals
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - JuFang Wang
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania; and
| | - Nicole Tubbs
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - Joseph Y Cheung
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania; and Department of Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Philippe Haouzi
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
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Abstract
The cardiac Ca²⁺ release channel [ryanodine receptor type 2 (RyR2)] is modulated by thiol reactive agents, but the molecular basis of RyR2 modulation by thiol reagents is poorly understood. Cys³⁶³⁵ in the skeletal muscle RyR1 is one of the most hyper-reactive thiols and is important for the redox and calmodulin (CaM) regulation of the RyR1 channel. However, little is known about the role of the corresponding cysteine residue in RyR2 (Cys³⁶⁰²) in the function and regulation of the RyR2 channel. In the present study, we assessed the impact of mutating Cys³⁶⁰² (C³⁶⁰²A) on store overload-induced Ca²⁺ release (SOICR) and the regulation of RyR2 by thiol reagents and CaM. We found that the C³⁶⁰²A mutation suppressed SOICR by raising the activation threshold and delayed the termination of Ca²⁺ release by reducing the termination threshold. As a result, C³⁶⁰²A markedly increased the fractional Ca²⁺ release. Furthermore, the C³⁶⁰²A mutation diminished the inhibitory effect of N-ethylmaleimide on Ca²⁺ release, but it had no effect on the stimulatory action of 4,4'-dithiodipyridine (DTDP) on Ca²⁺ release. In addition, Cys³⁶⁰² mutations (C³⁶⁰²A or C³⁶⁰²R) did not abolish the effect of CaM on Ca²⁺-release termination. Therefore, RyR2-Cys³⁶⁰² is a major site mediating the action of thiol alkylating agent N-ethylmaleimide, but not the action of the oxidant DTDP. Our data also indicate that residue Cys³⁶⁰² plays an important role in the activation and termination of Ca²⁺ release, but it is not essential for CaM regulation of RyR2.
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14
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Tian C, Shao CH, Padanilam C, Ezell E, Singh J, Kutty S, Bidasee KR. CCDI: a new ligand that modulates mammalian type 1 ryanodine receptor (RyR1). Br J Pharmacol 2014; 171:4097-111. [PMID: 24819467 DOI: 10.1111/bph.12764] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 04/21/2014] [Accepted: 04/29/2014] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND AND PURPOSE Ryanodine receptors (RyRs) are Ca(2+)-release channels on the sarco(endo)plasmic reticulum that modulate a wide array of physiological functions. Three RyR isoforms are present in cells: RyR1, RyR2 and RyR3. To date, there are no reports on ligands that modulate RyR in an isoform-selective manner. Such ligands are not only valuable research tools, but could serve as intermediates for development of therapeutics. EXPERIMENTAL APPROACH Pyrrole-2-carboxylic acid and 1,3-dicyclohexylcarbodiimide were allowed to react in carbon tetrachloride for 24 h at low temperatures and pressures. The chemical structures of the two products isolated were elucidated using NMR spectrometry, mass spectrometry and elemental analyses. [(3) H]-ryanodine binding, lipid bilayer and time-lapsed confocal imaging were used to determine their effects on RyR isoforms. KEY RESULTS The major product, 2-cyclohexyl-3-cyclohexylimino-2, 3, dihydro-pyrrolo[1,2-c]imidazol-1-one (CCDI) dose-dependently potentiated Ca(2+)-dependent binding of [(3)H]-ryanodine to RyR1, with no significant effects on [(3)H]-ryanodine binding to RyR2 or RyR3. CCDI also reversibly increased the open probability (P(o)) of RyR1 with minimal effects on RyR2 and RyR3. CCDI induced Ca(2+) transients in C2C12 skeletal myotubes, but not in rat ventricular myocytes. This effect was blocked by pretreating cells with ryanodine. The minor product 2-cyclohexyl-pyrrolo[1,2-c]imidazole-1,3-dione had no effect on either [(3)H]-ryanodine binding or P(o) of RyR1, RyR2 and RyR3. CONCLUSIONS AND IMPLICATIONS A new ligand that preferentially modulates RyR1 was identified. In addition to being an important research tool, the pharmacophore of this small molecule could serve as a template for the synthesis of other isoform-selective modulators of RyRs.
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Affiliation(s)
- Chengju Tian
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, USA
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Non-invasive label-free monitoring the cardiac differentiation of human embryonic stem cells in-vitro by Raman spectroscopy. Biochim Biophys Acta Gen Subj 2013; 1830:3517-24. [DOI: 10.1016/j.bbagen.2013.01.030] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 01/28/2013] [Accepted: 01/30/2013] [Indexed: 01/06/2023]
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16
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Fauconnier J, Roberge S, Saint N, Lacampagne A. Type 2 ryanodine receptor: A novel therapeutic target in myocardial ischemia/reperfusion. Pharmacol Ther 2013; 138:323-32. [DOI: 10.1016/j.pharmthera.2013.01.015] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Accepted: 01/22/2013] [Indexed: 10/27/2022]
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17
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Palmer LA, May WJ, deRonde K, Brown-Steinke K, Bates JN, Gaston B, Lewis SJ. Ventilatory responses during and following exposure to a hypoxic challenge in conscious mice deficient or null in S-nitrosoglutathione reductase. Respir Physiol Neurobiol 2012. [PMID: 23183419 DOI: 10.1016/j.resp.2012.11.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Exposure to a hypoxic challenge increases ventilation in wild-type (WT) mice that diminish during the challenge (roll-off) whereas return to room air causes an increase in ventilation (short-term facilitation, STF). Since plasma and tissue levels of ventilatory excitant S-nitrosothiols such as S-nitrosoglutathione (GSNO) increase during hypoxia, this study examined whether (1) the initial increase in ventilation is due to generation of GSNO, (2) roll-off is due to increased activity of the GSNO degrading enzyme, GSNO reductase (GSNOR), and (3) STF is limited by GSNOR activity. Initial ventilatory responses to hypoxic challenge (10% O(2), 90% N(2)) were similar in WT, GSNO+/- and GSNO-/- mice. These responses diminished markedly during hypoxic challenge in WT mice whereas there was minimal roll-off in GSNOR+/- and GSNOR-/- mice. Finally, STF was greater in GSNOR+/- and GSNOR-/- mice than in WT mice (especially females). This study suggests that GSNOR degradation of GSNO is a vital step in the expression of ventilatory roll-off and that GSNOR suppresses STF.
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Affiliation(s)
- Lisa A Palmer
- Pediatric Respiratory Medicine, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
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18
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Liao WC, Chou CT, Kuo CC, Pan CC, Kuo DH, Shieh P, Cheng JS, Jan CR, Shaw CF. Effect of thimerosal on Ca2+ movement and apoptosis in PC3 prostate cancer cells. Drug Dev Res 2011. [DOI: 10.1002/ddr.20434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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19
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Zhou L, Aon MA, Liu T, O'Rourke B. Dynamic modulation of Ca2+ sparks by mitochondrial oscillations in isolated guinea pig cardiomyocytes under oxidative stress. J Mol Cell Cardiol 2011; 51:632-9. [PMID: 21645518 DOI: 10.1016/j.yjmcc.2011.05.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 05/11/2011] [Indexed: 01/10/2023]
Abstract
Local control of Ca(2+)-induced Ca(2+) release (CICR) depends on the spatial organization of L-type Ca(2+) channels and ryanodine receptors (RyR) in the dyad. Analogously, Ca(2+) uptake by mitochondria is facilitated by their close proximity to the Ca(2+) release sites, a process required for stimulating oxidative phosphorylation during changes in work. Mitochondrial feedback on CICR is less well understood. Since mitochondria are a primary source of reactive oxygen species (ROS), they could potentially influence the cytosolic redox state, in turn altering RyR open probability. We have shown that self-sustained oscillations in mitochondrial inner membrane potential (ΔΨ(m)), NADH, ROS, and reduced glutathione (GSH) can be triggered by a laser flash in cardiomyocytes. Here, we employ this method to directly examine how acute changes in energy state dynamically influence resting Ca(2+) spark occurrence and properties. Two-photon laser scanning microscopy was used to monitor cytosolic Ca(2+) (or ROS), ΔΨ(m), and NADH (or GSH) simultaneously in isolated guinea pig cardiomyocytes. Resting Ca(2+) spark frequency increased with each ΔΨ(m) depolarization and decreased with ΔΨ(m) repolarization without affecting Ca(2+) spark amplitude or time-to-peak. Stabilization of mitochondrial energetics by pretreatment with the superoxide scavenger TMPyP, or by acute addition of 4'-chlorodiazepam, a mitochondrial benzodiazepine receptor antagonist that blocks the inner membrane anion channel, prevented or reversed, respectively, the increased spark frequency. Cyclosporine A did not block the ΔΨ(m) oscillations or prevent Ca(2+) spark modulation by ΔΨ(m). The results support the hypothesis that mitochondria exert an influential role on the redox environment of the Ca(2+) handling subsystem, with mechanistic implications for the pathophysiology of cardiac disease.
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Affiliation(s)
- Lufang Zhou
- Department of Medicine, Division of Cardiology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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20
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Dulhunty AF, Hewawasam R, Liu D, Casarotto MG, Board PG. Regulation of the cardiac muscle ryanodine receptor by glutathione transferases. Drug Metab Rev 2011; 43:236-52. [DOI: 10.3109/03602532.2010.549134] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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21
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Joseph SK. Role of thiols in the structure and function of inositol trisphosphate receptors. CURRENT TOPICS IN MEMBRANES 2010; 66:299-322. [PMID: 22353485 DOI: 10.1016/s1063-5823(10)66013-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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22
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Kuo LN, Huang CJ, Fang YC, Huang CC, Wang JL, Lin KL, Chu ST, Chang HT, Chien JM, Su HH, Chi CC, Chen WC, Tsai JY, Liao WC, Tseng LL, Jan CR. Effect of thimerosal on Ca2+ movement and viability in human oral cancer cells. Hum Exp Toxicol 2009; 28:301-8. [DOI: 10.1177/0960327109106548] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The effect of thimerosal on cytosolic free Ca2+ concentrations ([Ca2+]i ) in human oral cancer cells (OC2) is unclear. This study explored whether thimerosal changed basal [Ca2+]i levels in suspended OC2 cells using fura-2. Thimerosal at concentrations between 1and 50 μM increased [Ca2+]i in a concentration-dependent manner. The Ca2+ signal was reduced partly by removing extracellular Ca 2+. Thimerosal-induced Ca2+ influx was not blocked by L-type Ca2+ entry inhibitors and protein kinase C modulators (phorbol 12-myristate 13-acetate [PMA] and GF109203X). In Ca2+-free medium, 50 μM thimerosal failed to induce a [Ca2+]i rise after pretreatment with thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor). Inhibition of phospholipase C with U73122 did not change thimerosal-induced [Ca2+]i rises. At concentrations between 5 and 10 μM, thimerosal killed cells in a concentration-dependent manner. The cytotoxic effect of 8 μM thimerosal was potentiated by prechelating cytosolic Ca2+ with the Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetate/acetomethyl (BAPTA/ AM). Flow cytometry data suggested that 1—7 μM thimerosal-induced apoptosis in a concentration-dependent manner. Collectively, in OC2 cells, thimerosal-induced [Ca2+]i rises by causing phospholipase C-independent Ca2+ release from the endoplasmic reticulum and Ca2+ influx through non—L-type Ca2+ channels. Thimerosal killed cells in a concentration-dependent manner through apoptosis.
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Affiliation(s)
- LN Kuo
- Department of Pathology and Laboratory Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung, Taiwan
| | - CJ Huang
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan, Department of Psychiatry, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - YC Fang
- Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung, Taiwan, Laboratory Medicine Division, Zuoying Armed Forces General Hospital, Kaohsiung, Taiwan
| | - CC Huang
- Department of Nursing, Tzu Hui Institute of Technology; Pingtung, Taiwan
| | - JL Wang
- Department of Rehabilitation, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - KL Lin
- Department of Rehabilitation, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - ST Chu
- Department of Otolaryngology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - HT Chang
- Department of Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - JM Chien
- Department of Pediatrics, Ping Tung Christian Hospital, Ping Tung, Taiwan
| | - HH Su
- Department of Otolaryngology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - CC Chi
- Department of Otolaryngology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - WC Chen
- Department of Surgery, Ping Tung Christian Hospital, Ping Tung, Taiwan
| | - JY Tsai
- Department of Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - WC Liao
- Department of Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - LL Tseng
- Department of Dentist, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - CR Jan
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan,
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23
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Caulfield VL, Balmer C, Dawson LJ, Smith PM. A role for nitric oxide-mediated glandular hypofunction in a non-apoptotic model for Sjogren's syndrome. Rheumatology (Oxford) 2009; 48:727-33. [PMID: 19429907 DOI: 10.1093/rheumatology/kep100] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVE To investigate a role for the inflammatory mediator, nitric oxide (NO) in SS, an autoimmune condition characterized by salivary and lacrimal gland hypofunction resulting from failure of acinar cells to secrete. METHODS FURA-2 microfluorimetry was used to measure agonist-evoked changes of [Ca(2+)](i) in isolated mouse and human salivary acinar cells following exposure to NO donors. RESULTS NO had a biphasic effect on salivary acinar function. Acute exposure to NO (2 min) caused a cyclic guanosine monophosphate (GMP)-dependent, 1-H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-sensitive increase in the Ca(2+) signal elicited in response to acetylcholine (ACh) stimulation, consistent with stimulation of ryanodine receptors by cyclic adenosine diphosphate ribose. Prolonged exposure to NO (>40 min) significantly reduced the ACh-evoked Ca(2+) signal by a mechanism independent of cyclic GMP. We found no differences between the responses of human and mouse acinar cells. CONCLUSION Our data show that chronic exposure to NO, which is known to be elevated in SS, could have a role in salivary gland hypofunction. We note a similarity in the response to stimulation of salivary acinar exposed to NO and that which we have previously reported in salivary acinar cells isolated from patients with SS. We speculate that NO-mediated nitrosylation of one or more elements of the signal transduction pathway could underlie down-regulation of salivary function in SS.
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Jalilian C, Gallant EM, Board PG, Dulhunty AF. Redox potential and the response of cardiac ryanodine receptors to CLIC-2, a member of the glutathione S-transferase structural family. Antioxid Redox Signal 2008; 10:1675-86. [PMID: 18522493 DOI: 10.1089/ars.2007.1994] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The type 2 chloride intracellular channel, CLIC-2, is a member of the glutathione S-transferase structural family and a suppressor of cardiac ryanodine receptor (RyR2) Ca2+ channels located in the membrane of the sarcoplasmic reticulum (SR). Modulators of RyR2 activity can alter cardiac contraction. Since both CLIC-2 and RyR2 are modified by redox reactions, we speculated that the action of CLIC-2 on RyR2 may depend on redox potential. We used a GSH:GSSG buffer system to produce mild changes in redox potential to influence redox sensors in RyR2 and CLIC-2. RyR2 activity was modified only when both luminal and cytoplasmic solutions contained the GSH:GSSG buffer and the effects were reversed by removing the buffer from one of the solutions. Channel activity increased with an oxidizing redox potential and decreased when the potential was more reducing. Addition of cytoplasmic CLIC-2 inhibited RyR2 with oxidizing redox potentials, but activated RyR2 under reducing conditions. The results suggested that both RyR2 and CLIC-2 contain redox sensors. Since cardiac ischemia involves a destructive Ca2+ overload that is partly due to oxidation-induced increase in RyR2 activity, we speculate that the properties of CLIC-2 place it in an ideal position to limit ischemia-induced cellular damage in cardiac muscle.
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Affiliation(s)
- Chris Jalilian
- Division of Molecular Bioscience, John Curtin School of Medical Research, Australian National University, ACT, Australia
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25
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Sharov VS, Schöneich C. Chapter 6 Oxidative Modification of Ca2+ Channels, Ryanodine Receptors, and the Sarco/Endoplasmic Reticulum Ca2+-ATPase. CURRENT TOPICS IN MEMBRANES 2008. [DOI: 10.1016/s1063-5823(08)00206-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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26
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Hool LC. What Cardiologists Should Know About Calcium Ion Channels and Their Regulation by Reactive Oxygen Species. Heart Lung Circ 2007; 16:361-72. [PMID: 17353151 DOI: 10.1016/j.hlc.2007.01.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2006] [Accepted: 01/16/2007] [Indexed: 12/17/2022]
Abstract
Ion channels underlie the electrical activity of cells. Calcium channels have a unique functional role, because not only do they participate in this activity, they form the means by which electrical signals are converted to responses within the cell. Calcium channels play an integral role in excitation in the heart and shaping the cardiac action potential. In addition, calcium influx through calcium channels is responsible for initiating contraction. Abnormalities in calcium homeostasis underlie cardiac arrhythmia, contractile dysfunction and cardiac remodelling. Reactive oxygen species participate in the development of pathology by altering the redox state of regulatory proteins. There is now good evidence that reactive oxygen species regulate the function of calcium channels. In this mini-review, the evidence for regulation of calcium channels by reactive oxygen species and implications with respect to pathology are presented. Calcium channels may represent a target for intervention during hypoxic trigger of arrhythmia or chronic pathological remodelling.
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Affiliation(s)
- Livia C Hool
- Discipline of Physiology, School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Crawley, Western Australia.
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27
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Marinov BS, Olojo RO, Xia R, Abramson JJ. Non-thiol reagents regulate ryanodine receptor function by redox interactions that modify reactive thiols. Antioxid Redox Signal 2007; 9:609-21. [PMID: 17465884 DOI: 10.1089/ars.2006.1426] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The Ca(2+) release channel (CRC) from sarcoplasmic reticulum (SR) is rich in thiol groups, and their oxidation/- reduction by thiol reagents activates/inhibits the CRC. Most channel regulators are not thiol reagents, and the mechanism of their action is illusive. Here the authors show that many channel activators act as electron acceptors, while many channel inhibitors act as electron donors in free radical reactions. The channel activator, caffeine, and the CRC inhibitor, tetracaine, are shown to interact competitively, which suggests that there exists a common site(s) on the CRC, that integrates the donor/acceptor effects of ligands. Moreover, channel activators shift the redox potential of reactive thiols on the ryanodine receptor (RyR) to more negative values and decrease the number of reactive thiols, while channel inhibitors shift the redox potential to more positive values and increase the number of reactive thiols. These observations suggest that the non-thiol channel modulators shift the thiol-disulfide balance within CRC by transiently exchanging electrons with the Ca(2+) release protein.
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Affiliation(s)
- Benjamin S Marinov
- Physics Department, Portland State University, Portland, Oregon 97207, USA
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28
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Abstract
Calcium plays an integral role in cellular function. It is a well-recognized second messenger necessary for signaling cellular responses, but in excessive amounts can be deleterious to function, causing cell death. The main route by which calcium enters the cytoplasm is either from the extracellular compartment or internal addistores via calcium channels. There is good evidence that calcium channels can respond to pharmacological compounds that reduce or oxidize thiol groups on the channel protein. In addition, reactive oxygen species such as hydrogen peroxide and superoxide that can mediate oxidative pathology also mediate changes in channel function via alterations of thiol groups. This review looks at the structure and function of calcium channels, the evidence that changes in cellular redox state mediate changes in channel function, and the role of redox modification of channels in disease processes. Understanding how redox modification of the channel protein alters channel structure and function is providing leads for the design of therapeutic interventions that target oxidative stress responses.
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Affiliation(s)
- Livia C Hool
- Discipline of Physiology, School of Biomedical, Biomolecular, and Chemical Sciences, The University of Western Australia, Crawley, Western Australia.
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29
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Joseph SK, Nakao SK, Sukumvanich S. Reactivity of free thiol groups in type-I inositol trisphosphate receptors. Biochem J 2006; 393:575-82. [PMID: 16173918 PMCID: PMC1360708 DOI: 10.1042/bj20050889] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The IP3R (inositol 1,4,5-trisphosphate receptor) Ca2+-release channel is known to be sensitive to thiol redox state. The present study was undertaken to characterize the number and location of reactive thiol groups in the type-I IP3R. Using the fluorescent thiol-reactive compound monobromobimane we found that approx. 70% of the 60 cysteine residues in the type-I IP3R are maintained in the reduced state. The accessibility of these residues was assessed by covalently tagging the IP3R in membranes with a 5 kDa or 20 kDa MPEG [methoxypoly(ethylene glycol) maleimide]. MPEG reaction caused a shift in the mobility of IP3R on SDS/PAGE that was blocked by pretreatment of the membranes with dithiothreitol, N-ethylmaleimide, mersalyl or thimerosal, indicating that MPEG reactivity was specific to thiol groups on the IP3R. Trypsin cleavage of the type-I IP3R generates five defined domains. In cerebellum membranes, MPEG reacted over a 5 min interval with tryptic fragment I and fragment III, but not fragments II, IV or V. Fragment I appears as a doublet in cerebellum membranes, corresponding to the presence and absence of the SI splice site in this region (SI is a spliced domain corresponding to amino acids 318-332). Only the fragment I band corresponding to the SI(+) splice form shifted after reaction with MPEG. Expression of SI(+) and SI(-) spliced forms in COS cell microsomes confirmed this result. The MPEG-induced shift was not prevented when the cysteine residue present in the SI splice domain (C326A) or the remaining seven cysteine residues in fragment I were individually mutated. Of the combination mutations screened, only the mutation of C206/214/326A blocked MPEG reactivity in fragment I. We conclude that a set of highly reactive cysteine residues in fragment I are differentially accessible in the SI(+) and SI(-) splice variants of the type-I IP3R.
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Affiliation(s)
- Suresh K Joseph
- Department of Pathology, Thomas Jefferson University, Room 230A JAH, 1020 Locust Street, Philadelphia, PA 19107, USA.
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30
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Yi XY, Li VX, Zhang F, Yi F, Matson DR, Jiang MT, Li PL. Characteristics and actions of NAD(P)H oxidase on the sarcoplasmic reticulum of coronary artery smooth muscle. Am J Physiol Heart Circ Physiol 2006; 290:H1136-44. [PMID: 16227345 DOI: 10.1152/ajpheart.00296.2005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It has been reported that nonmitochondrial NAD(P)H oxidases make an important contribution to intracellular O2−· in vascular tissues and, thereby, the regulation of vascular function. Topological analyses have suggested that a well-known membrane-associated NAD(P)H oxidase may not release O2−· into the cytosol. It is imperative to clarify the source of intracellular O2−· associated with this enzyme and its physiological significance in vascular cells. The present study hypothesized that an NAD(P)H oxidase on the sarcoplasmic reticulum (SR) in coronary artery smooth muscle (CASM) regulates SR ryanodine receptor (RyR) activity by producing O2−· locally. Western blot analysis was used to detect NAD(P)H oxidase subunits in purified SR from CASM. Fluorescent spectrometric analysis demonstrated that incubation of SR with NADH time dependently produced O2−·, which could be substantially blocked by the specific NAD(P)H oxidase inhibitors diphenylene iodonium and apocynin and by SOD or its mimetic tiron. This SR NAD(P)H oxidase activity was also confirmed by HPLC analysis of conversion of NADH to NAD+. In experiments of lipid bilayer channel reconstitution, addition of NADH to the cis solution significantly increased the activity of RyR/Ca2+release channels from these SR preparations from CASM, with a maximal increase in channel open probability from 0.0044 ± 0.0005 to 0.0213 ± 0.0018; this effect of NADH was markedly blocked in the presence of SOD or tiron or the NAD(P)H oxidase inhibitors diphenylene iodonium, N-vanillylnonanamide, and apocynin. These results suggest that a local NAD(P)H oxidase system on SR from CASM regulates RyR/Ca2+channel activity and Ca2+release from SR by producing O2−·.
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Affiliation(s)
- Xiu-Yu Yi
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, USA
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31
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Dulhunty AF, Pouliquin P, Coggan M, Gage PW, Board PG. A recently identified member of the glutathione transferase structural family modifies cardiac RyR2 substate activity, coupled gating and activation by Ca2+ and ATP. Biochem J 2005; 390:333-43. [PMID: 15916532 PMCID: PMC1184587 DOI: 10.1042/bj20042113] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The recently discovered CLIC-2 protein (where CLIC stands for chloride intracellular channel), which belongs to the ubiquitous glutathione transferase structural family and is expressed in the myocardium, is a regulator of native cardiac RyR2 (ryanodine receptor 2) channels. Here we show that recombinant CLIC-2 increases [3H]ryanodine binding to native and purified RyR channels, enhances substate activity in individual channels, increases the number of rare coupled gating events between associated RyRs, and reduces activation of the channels by their primary endogenous cytoplasmic ligands, ATP and Ca2+. CLIC-2 (0.2-10 microM) added to the cytoplasmic side of RyR2 channels in lipid bilayers depressed activity in a reversible, voltage-independent, manner in the presence of activating (10-100 microM) or sub-activating (100 nM) cytoplasmic Ca2+ concentrations. Although the number of channel openings to all levels was reduced, the fraction and duration of openings to substate levels were increased after exposure to CLIC-2. CLIC-2 reduced increases in activity induced by ATP or adenosine 5'-[beta,gamma-imido]triphosphate. Depression of channel activity by CLIC-2 was greater in the presence of 100 microM cytoplasmic Ca2+ than with 100 nM or 10 microM Ca2+. Further, CLIC-2 prevented the usual approximately 50-fold increase in activity when the cytoplasmic Ca2+ concentration was increased from 100 nM to 100 microM. The results show that CLIC-2 interacts with the RyR protein by a mechanism that does not require oxidation, but is influenced by a conserved Cys residue at position 30. CLIC-2 is one of only a few cytosolic inhibitors of cardiac RyR2 channels, and may suppress their activity during diastole and during stress. CLIC-2 provides a unique probe for substate activity, coupled gating and ligand-induced activation of cardiac RyR channels.
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Affiliation(s)
- Angela F Dulhunty
- Division of Molecular Bioscience, John Curtin School of Medical Research, P.O. Box 334, Canberra, ACT 2601, Australia.
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32
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Hurne AM, O'Brien JJ, Wingrove D, Cherednichenko G, Allen PD, Beam KG, Pessah IN. Ryanodine Receptor Type 1 (RyR1) Mutations C4958S and C4961S Reveal Excitation-coupled Calcium Entry (ECCE) Is Independent of Sarcoplasmic Reticulum Store Depletion. J Biol Chem 2005; 280:36994-7004. [PMID: 16120606 DOI: 10.1074/jbc.m506441200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Bi-directional signaling between ryanodine receptor type 1 (RyR1) and dihydropyridine receptor (DHPR) in skeletal muscle serves as a prominent example of conformational coupling. Evidence for a physiological mechanism that upon depolarization of myotubes tightly couples three calcium channels, DHPR, RyR1, and a Ca(2+) entry channel with SOCC-like properties, has recently been presented. This form of conformational coupling, termed excitation-coupled calcium entry (ECCE) is triggered by the alpha(1s)-DHPR voltage sensor and is highly dependent on RyR1 conformation. In this report, we substitute RyR1 cysteines 4958 or 4961 within the TXCFICG motif, common to all ER/SR Ca(2+) channels, with serine. When expressed in skeletal myotubes, C4958S- and C4961S-RyR1 properly target and restore L-type current via the DHPR. However, these mutants do not respond to RyR activators and do not support skeletal type EC coupling. Nonetheless, depolarization of cells expressing C4958S- or C4961S-RyR1 triggers calcium entry via ECCE that resembles that for wild-type RyR1, except for substantially slowed inactivation and deactivation kinetics. ECCE in these cells is completely independent of store depletion, displays a cation selectivity of Ca(2+)>Sr(2+) approximately Ba(2+), and is fully inhibited by SKF-96365 or 2-APB. Mutation of other non-CXXC motif cysteines within the RyR1 transmembrane assembly (C3635S, C4876S, and C4882S) did not replicate the phenotype observed with C4958S- and C4961S-RyR1. This study demonstrates the essential role of Cys(4958) and Cys(4961) within an invariant CXXC motif for stabilizing conformations of RyR1 that influence both its function as a release channel and its interaction with ECCE channels.
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Affiliation(s)
- Alanna M Hurne
- Department of Molecular Biosciences, School of Veterinary Medicine and Center for Children's Environmental Health and Disease Prevention, University of California, Davis, California 95616, USA
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33
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Chang HT, Liu CS, Chou CT, Hsieh CH, Chang CH, Chen WC, Liu SI, Hsu SS, Chen JS, Jiann BP, Jan CR. Thimerosal-induced cytosolic Ca2+ elevation and subsequent cell death in human osteosarcoma cells. Pharmacol Res 2005; 52:328-33. [PMID: 15964764 DOI: 10.1016/j.phrs.2005.05.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2005] [Revised: 05/09/2005] [Accepted: 05/13/2005] [Indexed: 11/26/2022]
Abstract
The effect of the oxidizing agent thimerosal on cytosolic free Ca(2+) concentration ([Ca(2+)]i) and proliferation has not been explored in human osteoblast-like cells. This study examined whether thimerosal alters Ca(2+) levels and causes cell death in MG63 human osteosarcoma cells. [Ca(2+)]i and cell death were measured using the fluorescent dyes fura-2 and WST-1, respectively. Thimerosal at concentrations above 5 microM increased [Ca(2+)]i in a concentration-dependent manner. The Ca(2+) signal was reduced by 80% by removing extracellular Ca(2+). The thimerosal-induced Ca(2+) influx was sensitive to blockade of La(3+), and dithiothreitol (50 microM) but was insensitive to nickel and several L-type Ca(2+) channel blockers. After pretreatment with 1 microM thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor), thimerosal failed to induce [Ca(2+)]i rises. Inhibition of phospholipase C with 2 microM U73122 did not change thimerosal-induced [Ca(2+)]i rises. At concentrations of 5, 10 and 20 microM thimerosal killed 33, 55 and 100% cells, respectively. The cytotoxic effect of 5 microM thimerosal was reversed by 54% by prechelating cytosolic Ca(2+) with BAPTA. Collectively, in MG63 cells, thimerosal induced a [Ca(2+)]i rise by causing Ca(2+) release from endoplasmic reticulum stores and Ca(2+) influx from extracellular space. Furthermore, thimerosal can cause Ca(2+)-related cytotoxicity in a concentration-dependent manner.
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Affiliation(s)
- Hong-Tai Chang
- Department of Surgery, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan
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34
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Anyatonwu GI, Ehrlich BE. Organic cation permeation through the channel formed by polycystin-2. J Biol Chem 2005; 280:29488-93. [PMID: 15961385 DOI: 10.1074/jbc.m504359200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Polycystin-2 (PC2), a member of the transient receptor potential family of ion channels (TRPP2), forms a calcium-permeable cation channel. Mutations in PC2 lead to polycystic kidney disease. From the primary sequence and by analogy with other channels in this family, PC2 is modeled to have six transmembrane domains. However, most of the structural features of PC2, such as how large the channel is and how many subunits make up the pore of the channel, are unknown. In this study, we estimated the pore size of PC2 from the permeation properties of the channel. Organic cations of increasing size were used as current carriers through the PC2 channel after PC2 was incorporated into lipid bilayers. We found that dimethylamine, triethylamine, tetraethylammonium, tetrabutylammonium, tetrapropylammonium, and tetrapentylammonium were permeable through the PC2 channel. The slope conductance of the PC2 channel decreased as the ionic diameter of the organic cation increased. For each organic cation tested, the currents were inhibited by gadolinium and anti-PC2 antibody. Using the dimensions of the largest permeant cation, the minimum pore diameter of the PC2 channel was estimated to be at least 11 A. The large pore size suggests that the primary state of this channel found in vivo is closed to avoid rundown of cation gradients across the plasma membrane and excessive calcium leak from endoplasmic reticulum stores.
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Affiliation(s)
- Georgia I Anyatonwu
- Pharmacology and Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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35
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Voss AA, Lango J, Ernst-Russell M, Morin D, Pessah IN. Identification of hyperreactive cysteines within ryanodine receptor type 1 by mass spectrometry. J Biol Chem 2004; 279:34514-20. [PMID: 15197184 DOI: 10.1074/jbc.m404290200] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The skeletal-type ryanodine receptor (RyR1) undergoes covalent adduction by nitric oxide (NO), redox-induced shifts in cation regulation, and non-covalent interactions driven by the transmembrane redox potential that enable redox sensing. Tight redox regulation of RyR1 is thought to be primarily mediated through highly reactive (hyperreactive) cysteines. Of the 100 cysteines per subunit of RyR1, approximately 25-50 are reduced, with 6-8 considered hyperreactive. Thus far, only Cys-3635, which undergoes selective adduction by NO, has been identified. In this report, RyR1-enriched junctional sarcoplasmic reticulum is labeled with 7-diethylamino-3-(4'-maleimidylphenyl)-4-methylcoumarin (CPM, 1 pmol/microg of protein) in the presence of 10 mm Mg(2+), conditions previously shown to selectively label hyperreactive sulfhydryls and eliminate redox sensing. The CPM-adducted RyR1 is separated by gel electrophoresis and subjected to in-gel tryptic digestion. Isolation of CPM-adducted peptides is achieved by analytical and microbore high-performance liquid chromatography utilizing fluorescence and UV detection. Subsequent analysis using two direct and one tandem mass spectrometry methods results in peptide masses and sequence data that, compared with the known primary sequence of RyR1, enable unequivocal identification of CPM-adducted cysteines. This work is the first to directly identify seven hyperreactive cysteines: 1040, 1303, 2436, 2565, 2606, 2611, and 3635 of RyR1. In addition to Cys-3635, the nitrosylation site, six additional cysteines may contribute toward redox regulation of the RyR1 complex.
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Affiliation(s)
- Andrew A Voss
- School of Veterinary Medicine, Department of Molecular Biosciences, University of California, Davis, CA 95616, USA
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36
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Cucu D, Simaels J, Van Driessche W, Zeiske W. External Ni2 + and ENaC in A6 cells: Na+ current stimulation by competition at a binding site for amiloride and Na+. J Membr Biol 2004; 194:33-45. [PMID: 14502441 DOI: 10.1007/s00232-003-2023-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2003] [Indexed: 11/25/2022]
Abstract
In cultured A6 monolayers from distal Xenopus kidney, external Ni2+ stimulated active Na+ uptake via the epithelial Na+ channel, ENaC. Transepithelial capacitance measurements ruled out exocytosis of ENaC-containing vesicles underlying the Ni2+ effect. Na+ current noise analysis was performed using the neutral Na(+) -channel blocker 6-chloro-3,5-diamino-pyrazine-2-carboxamide (CDPC) and amiloride. The analysis of CDPC-induced noise in terms of a three-state channel model revealed that Ni2+ elicits an increase in the number of open channels as well as in the spontaneous open probability. While Ni2+ had no influence on CDPC-blocker kinetics, the macroscopic and microscopic blocking kinetics of amiloride were affected. Ni2+ turned out to compete with amiloride for a putative binding site but not with CDPC. Moreover, external Na(+)--known to compete with amiloride and so producing the "self-inhibition" phenomenon--and Ni2+ exerted mutually exclusive analogous effects on amiloride kinetics. Na+ current kinetics revealed that Ni2+ prevents ENaC to be downregulated by self-inhibition. Co2+ behaved similarly to Ni2+, whereas Zn2+ did not. Attempts to disclose the chemical nature of the site reacting with Ni2+ suggested cysteine but not histidine as reaction partner.
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Affiliation(s)
- D Cucu
- Laboratory of Physiology, K. U. Leuven, Campus Gasthuisberg O/N, B-3000 Leuven, Belgium
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37
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Anyatonwu GI, Buck ED, Ehrlich BE. Methanethiosulfonate ethylammonium block of amine currents through the ryanodine receptor reveals single pore architecture. J Biol Chem 2003; 278:45528-38. [PMID: 12963712 DOI: 10.1074/jbc.m307863200] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The homotetrameric structure of the ryanodine-sensitive intracellular calcium (Ca2+) release channel (ryanodine receptor (RyR)) suggests that the four RyR subunits either combine to form a single pore or that each RyR subunit is an independently conducting pathway. Previously we showed that methanethiosulfonate ethylammonium (MTSEA+) covalently modifies the RyR to reduce current amplitudes in a time-dependent and stepwise manner. To ascertain the number of functionally conducting pores in the RyR, two approaches were combined: modification of the receptor by MTSEA+ and the use of different sized current carriers. Previous reports (Tinker, A., and Williams, A. J. (1993) J. Gen. Physiol. 102, 1107-1129) have shown that the organic cations methylamine, dimethylamine, ethylamine, and trimethylamine are permeant through the RyR but with reduced current amplitude depending upon the diameter of the respective amine. Experiments using the thiol reagent MTSEA+ to modify the channel protein showed that the current amplitudes decrease in steps leading to complete block of the channel when cesium (Cs+) is the current carrier. MTSEA+ modification decreased the number of channel substates as the diameter of the current carrier increased. Comparison of the degree of inhibition of MTSEA+-modified currents allows for differentiation between the two models for channel architecture. These results demonstrate that the conduction pathway for the RyR is comprised of a single central pore.
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Affiliation(s)
- Georgia I Anyatonwu
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520-8356, USA
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38
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Lavi R, Shainberg A, Friedmann H, Shneyvays V, Rickover O, Eichler M, Kaplan D, Lubart R. Low energy visible light induces reactive oxygen species generation and stimulates an increase of intracellular calcium concentration in cardiac cells. J Biol Chem 2003; 278:40917-22. [PMID: 12851407 DOI: 10.1074/jbc.m303034200] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Low energy visible light (LEVL) irradiation has been shown to exert some beneficial effects on various cell cultures. For example, it increases the fertilizing capability of sperm cells, promotes cell proliferation, induces sprouting of neurons, and more. To learn about the mechanism of photobiostimulation, we studied the relationship between increased intracellular calcium ([Ca2+]i) and reactive oxygen species production following LEVL illumination of cardiomyocytes. We found that visible light causes the production of O2. and H2O2 and that exogenously added H2O2 (12 microm) can mimic the effect of LEVL (3.6 J/cm2) to induce a slow and transient increase in [Ca2+]i. This [Ca2+]i elevation can be reduced by verapamil, a voltage-dependent calcium channel inhibitor. The kinetics of [Ca2+]i elevation and morphologic damage following light or addition of H2O2 were found to be dose-dependent. For example, LEVL, 3.6 J/cm2, which induced a transient increase in [Ca2+]i, did not cause any cell damage, whereas visible light at 12 J/cm2 induced a linear increase in [Ca2+]i and damaged the cells. The linear increase in [Ca2+]i resulting from high energy doses of light could be attenuated into a non-linear small rise in [Ca2+]i by the presence of extracellular catalase during illumination. We suggest that the different kinetics of [Ca2+]i elevation following various light irradiation or H2O2 treatment represents correspondingly different adaptation levels to oxidative stress. The adaptive response of the cells to LEVL represented by the transient increase in [Ca2+]i can explain LEVL beneficial effects.
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Affiliation(s)
- Ronit Lavi
- Department of Chemistry, Bar-Ilan University, Ramat-Gan 52900, Israel.
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39
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Dulhunty AF, Pouliquin P. What we don't know about the structure of ryanodine receptor calcium release channels. Clin Exp Pharmacol Physiol 2003; 30:713-23. [PMID: 14516409 DOI: 10.1046/j.1440-1681.2003.03904.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
1. The ryanodine receptor (RyR) is the Ca2+ release channel in the sarcoplamic reticulum of skeletal and cardiac muscle and is essential for respiration and heart beat. The RyR channel releases Ca2+ from intracellular stores in a variety of other cell types, where it normally coexists with the inositiol 1,4,5-trisphosphate receptor (IP3R). The RyR and IP3R, forming a superfamily of homotetrameric ligand-gated intracellular Ca2+ channels, serve discrete functions: they can be located in independent Ca2+ stores with different activation mechanisms and can be coupled to different signalling pathways. 2. Although functional characteristics of the RyR have been investigated intensely, there remain major gaps in our knowledge about the structure of the protein, its ion-conducting pore, its ligand-binding sites and sites supporting the many protein/protein interactions that underlie the in vivo function of the channel. 3. Of particular importance are the transmembrane segments that form the membrane-spanning domain of the protein and the pore, define the conductance and selectivity of the channel and dictate the cytoplasmic and luminal domains and the overall protein structure. Hydropathy profiles predict between four and 12 transmembrane segments. One popular model shows four transmembrane segments in the C-terminal one-tenth of the protein. However, there is substantial evidence for a larger number of membrane-spanning segments located in both the C-terminal and central parts of the protein. 4. A model of the RyR pore based on the Streptomyces lividans KcsA channel structure is presented. Protein/protein interactions between the RyR and other regulatory proteins, as well as within the RyR subunit, are discussed.
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Affiliation(s)
- Angela F Dulhunty
- The Muscle Research Group, John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory, Australia.
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40
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Sun J, Xu L, Eu JP, Stamler JS, Meissner G. Nitric oxide, NOC-12, and S-nitrosoglutathione modulate the skeletal muscle calcium release channel/ryanodine receptor by different mechanisms. An allosteric function for O2 in S-nitrosylation of the channel. J Biol Chem 2003; 278:8184-9. [PMID: 12509428 DOI: 10.1074/jbc.m211940200] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The skeletal muscle Ca(2+) release channel/ryanodine receptor (RyR1) contains approximately 50 thiols per subunit. These thiols have been grouped according to their reactivity/responsiveness toward NO, O(2), and glutathione, but the molecular mechanism enabling redox active molecules to modulate channel activity is poorly understood. In the case of NO, very low concentrations (submicromolar) activate RyR1 by S-nitrosylation of a single cysteine residue (Cys-3635), which resides within a calmodulin binding domain. S-Nitrosylation of Cys-3635 only takes place at physiological tissue O(2) tension (pO(2); i.e. approximately 10 mm Hg) but not at pO(2) approximately 150 mm Hg. Two explanations have been offered for the loss of RyR1 responsiveness to NO at ambient pO(2), i.e. Cys-3635 is oxidized by O(2) versus O(2) subserves an allosteric function (Eu, J. P., Sun, J. H., Xu, L., Stamler, J. S., and Meissner, G. (2000) Cell 102, 499-509). Here we report that the NO donors NOC-12 and S-nitrosoglutathione both activate RyR1 by release of NO but do so independently of pO(2). Moreover, NOC-12 activates the channel by S-nitrosylation of Cys-3635 and thereby reverses channel inhibition by calmodulin. In contrast, S-nitrosoglutathione activates RyR1 by oxidation and S-nitrosylation of thiols other than Cys-3635 (and calmodulin is not involved). Our results suggest that the effect of pO(2) on RyR1 S-nitrosylation is exerted through an allosteric mechanism.
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Affiliation(s)
- Junhui Sun
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill 27599-7260, USA
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41
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Abstract
In response to the increase in oxygen tension at birth, the resistance pulmonary arteries dilate, while the ductus arteriosus constricts. Although modulated by the endothelium, these opposite responses are intrinsic to the vascular smooth muscle. While still controversial, it seems likely that during normoxia the production of reactive oxygen species (ROS) increases and the smooth muscle cell cytoplasm is more oxidized in both pulmonary arteries and ductus, compared to hypoxia. However, the effect of changes in the endogenous redox status or the addition of a redox agent, oxidizing or reducing, is exactly opposite in the two vessels. A reducing agent, dithiothreitol, like hypoxia, in the pulmonary artery will inhibit potassium current, cause depolarization, increase cytosolic calcium and lead to contraction. Responses to dithiothreitol in the ductus are opposite and removal of endogenous H(2)O(2) by intracellular catalase in the ductus increases potassium current. Oxygen sensing in both vessels is probably mediated by redox effects on both calcium influx and calcium release from the sarcoplasmic reticulum (SR).
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Affiliation(s)
- E Kenneth Weir
- Department of Medicine, VA Medical Center, Minneapolis, MN 55417, USA.
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42
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Dulhunty AF, Laver D, Curtis SM, Pace S, Haarmann C, Gallant EM. Characteristics of irreversible ATP activation suggest that native skeletal ryanodine receptors can be phosphorylated via an endogenous CaMKII. Biophys J 2001; 81:3240-52. [PMID: 11720989 PMCID: PMC1301783 DOI: 10.1016/s0006-3495(01)75959-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Phosphorylation of skeletal muscle ryanodine receptor (RyR) calcium release channels by endogenous kinases incorporated into lipid bilayers with native sarcoplasmic reticulum vesicles was investigated during exposure to 2 mM cytoplasmic ATP. Activation of RyRs after 1-min exposure to ATP was reversible upon ATP washout. In contrast, activation after 5 to 8 min was largely irreversible: the small fall in activity with washout was significantly less than that after brief ATP exposure. The irreversible activation was reduced by acid phosphatase and was not seen after exposure to nonhydrolyzable ATP analogs. The data suggested that the channel complex was phosphorylated after addition of ATP and that phosphorylation reduced the RyR's sensitivity to ATP, adenosine, and Ca(2+). The endogenous kinase was likely to be a calcium calmodulin kinase II (CaMKII) because the CaMKII inhibitor KN-93 and an inhibitory peptide for CaMKII prevented the phosphorylation-induced irreversible activation. In contrast, phosphorylation effects remained unchanged with inhibitory peptides for protein kinase C and A. The presence of CaMKIIbeta in the SR vesicles was confirmed by immunoblotting. The results suggest that CaMKII is anchored to skeletal muscle RyRs and that phosphorylation by this kinase alters the enhancement of channel activity by ATP and Ca(2+).
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Affiliation(s)
- A F Dulhunty
- Muscle Research Group, John Curtin School of Medical Research, Canberra, ACT 2601, Australia.
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43
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Dulhunty A, Gage P, Curtis S, Chelvanayagam G, Board P. The glutathione transferase structural family includes a nuclear chloride channel and a ryanodine receptor calcium release channel modulator. J Biol Chem 2001; 276:3319-23. [PMID: 11035031 DOI: 10.1074/jbc.m007874200] [Citation(s) in RCA: 222] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The ubiquitous glutathione transferases (GSTs) catalyze glutathione conjugation to many compounds and have other diverse functions that continue to be discovered. We noticed sequence similarities between Omega class GSTs and a nuclear chloride channel, NCC27 (CLIC1), and show here that NCC27 belongs to the GST structural family. The structural homology prompted us to investigate whether the human Omega class glutathione transferase GSTO1-1 forms or modulates ion channels. We find that GSTO1-1 modulates ryanodine receptors (RyR), which are calcium channels in the endoplasmic reticulum of various cells. Cardiac RyR2 activity was inhibited by GSTO1-1, whereas skeletal muscle RyR1 activity was potentiated. An enzymatically active conformation of GSTO1-1 was required for inhibition of RyR2, and mutation of the active site cysteine (Cys-32 --> Ala) abolished the inhibitory activity. We propose a novel role for GSTO1-1 in protecting cells containing RyR2 from apoptosis induced by Ca(2+) mobilization from intracellular stores.
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Affiliation(s)
- A Dulhunty
- John Curtin School of Medical Research, Australian National University, P. O. Box 334, Canberra, Australian Capital Territory 2601, Australia
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44
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Reid MB. Invited Review: redox modulation of skeletal muscle contraction: what we know and what we don't. J Appl Physiol (1985) 2001; 90:724-31. [PMID: 11160074 DOI: 10.1152/jappl.2001.90.2.724] [Citation(s) in RCA: 289] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Over the past decade, reactive oxygen species (ROS) and nitric oxide (NO) derivatives have been established as physiological modulators of skeletal muscle function. This mini-review addresses the roles of these molecules as endogenous regulators of muscle contraction. The article is organized in two parts. First, established concepts are briefly outlined. This section provides an overview of ROS production by muscle, antioxidant buffers that oppose ROS effects, enzymatic synthesis of NO in muscle, the effects of endogenous ROS on contractile function, and NO as a contractile modulator. Second, a selected group of unresolved topics are highlighted. These more controversial issues include putative source(s) of regulatory ROS, the relative importance of the two NO synthase isoforms constitutively coexpressed by muscle fibers, molecular mechanisms of ROS and NO action, and the physiological relevance of redox regulation. By discussing current questions, as well as the established paradigm, this article is intended to further debate and stimulate research in this area.
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Affiliation(s)
- M B Reid
- Department of Medicine, Baylor College of Medicine, Houston, Texas 77030, USA.
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45
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Xia R, Stangler T, Abramson JJ. Skeletal muscle ryanodine receptor is a redox sensor with a well defined redox potential that is sensitive to channel modulators. J Biol Chem 2000; 275:36556-61. [PMID: 10952995 DOI: 10.1074/jbc.m007613200] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hyperreactive sulfhydryl groups associated with the Ca(2+) release protein from sarcoplasmic reticulum are shown to have a well defined reduction potential that is sensitive to the cellular environment. Ca(2+) channel activators lower the redox potential of the ryanodine receptor, which favors the oxidation of thiols and the opening of the Ca(2+) release protein. In contrast, channel inhibitors increase the redox potential, which favors the reduction of disulfides and the closure of the release protein. Modulation of redox potential of reactive thiols may be a general control mechanism by which sarcoplasmic/endoplasmic reticulum, ryanodine receptors/IP(3) receptors, control cytoplasmic Ca(2+) concentrations.
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Affiliation(s)
- R Xia
- Physics Department, Portland State University, Portland, Oregon 97207, USA
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46
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Feng W, Liu G, Allen PD, Pessah IN. Transmembrane redox sensor of ryanodine receptor complex. J Biol Chem 2000; 275:35902-7. [PMID: 10998414 DOI: 10.1074/jbc.c000523200] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Inositol 1,4,5-trisphosphate receptors (IP(3)R) and ryanodine receptors (RyR) mediate the release of endoplasmic and sarcoplasmic reticulum (ER/SR) Ca(2+) stores and regulate Ca(2+) entry through voltage-dependent or ligand-gated channels of the plasma membrane. A prominent property of ER/SR Ca(2+) channels is exquisite sensitivity to sulfhydryl-modifying reagents. A plausible role for sulfhydryl chemistry in physiologic regulation of Ca(2+) release channels and the fidelity of Ca(2+) release from ER/SR is lacking. This study reveals the existence of a transmembrane redox sensor within the RyR1 channel complex that confers tight regulation of channel activity in response to changes in transmembrane redox potential produced by cytoplasmic and luminal glutathione. A transporter selective for glutathione is co-localized with RyR1 within the SR membrane to maintain local redox potential gradients consistent with redox regulation of ER/SR Ca(2+) release. Hyperreactive sulfhydryls previously shown to reside within the RyR1 complex (Liu, G., and Pessah, I. N. (1994) J. Biol. Chem. 269, 33028-33034) are an essential biochemical component of a transmembrane redox sensor. Transmembrane redox sensing may represent a fundamental mechanism by which ER/SR Ca(2+) channels respond to localized changes in transmembrane glutathione redox potential produced by physiologic and pathophysiologic modulators of Ca(2+) release from stores.
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Affiliation(s)
- W Feng
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, California 95616, USA
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