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O’Connor TN, van den Bersselaar LR, Chen YS, Nicolau S, Simon B, Huseth A, Todd JJ, Van Petegem F, Sarkozy A, Goldberg MF, Voermans NC, Dirksena RT. RYR-1-Related Diseases International Research Workshop: From Mechanisms to Treatments Pittsburgh, PA, U.S.A., 21-22 July 2022. J Neuromuscul Dis 2023; 10:135-154. [PMID: 36404556 PMCID: PMC10023165 DOI: 10.3233/jnd-221609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Thomas N. O’Connor
- Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Luuk R. van den Bersselaar
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
- Malignant Hyperthermia Investigation Unit, Department of Anaesthesia, Canisius Wilhelmina Hospital, Nijmegen, the Netherlands
| | - Yu Seby Chen
- Department of Biochemistry and Molecular Biology, The Life Sciences Institute, The University of British Columbia, Vancouver, BC, Canada
| | - Stefan Nicolau
- Center for Gene Therapy, Nationwide Children’s Hospital, Columbus, OH, USA
| | | | | | - Joshua J. Todd
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, The Life Sciences Institute, The University of British Columbia, Vancouver, BC, Canada
| | - Anna Sarkozy
- The Dubowitz Neuromuscular Centre, Institute of Child Health and Great Ormond Street Hospital for Children, London, UK
| | | | - Nicol C. Voermans
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Robert T. Dirksena
- Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
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Rossi D, Catallo MR, Pierantozzi E, Sorrentino V. Mutations in proteins involved in E-C coupling and SOCE and congenital myopathies. J Gen Physiol 2022; 154:213407. [PMID: 35980353 PMCID: PMC9391951 DOI: 10.1085/jgp.202213115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 07/15/2022] [Accepted: 07/21/2022] [Indexed: 11/24/2022] Open
Abstract
In skeletal muscle, Ca2+ necessary for muscle contraction is stored and released from the sarcoplasmic reticulum (SR), a specialized form of endoplasmic reticulum through the mechanism known as excitation–contraction (E-C) coupling. Following activation of skeletal muscle contraction by the E-C coupling mechanism, replenishment of intracellular stores requires reuptake of cytosolic Ca2+ into the SR by the activity of SR Ca2+-ATPases, but also Ca2+ entry from the extracellular space, through a mechanism called store-operated calcium entry (SOCE). The fine orchestration of these processes requires several proteins, including Ca2+ channels, Ca2+ sensors, and Ca2+ buffers, as well as the active involvement of mitochondria. Mutations in genes coding for proteins participating in E-C coupling and SOCE are causative of several myopathies characterized by a wide spectrum of clinical phenotypes, a variety of histological features, and alterations in intracellular Ca2+ balance. This review summarizes current knowledge on these myopathies and discusses available knowledge on the pathogenic mechanisms of disease.
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Affiliation(s)
- Daniela Rossi
- Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy.,Interdepartmental Program of Molecular Diagnosis and Pathogenetic Mechanisms of Rare Genetic Diseases, Azienda Ospedaliero Universitaria Senese, Siena, Italy
| | - Maria Rosaria Catallo
- Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Enrico Pierantozzi
- Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - Vincenzo Sorrentino
- Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy.,Interdepartmental Program of Molecular Diagnosis and Pathogenetic Mechanisms of Rare Genetic Diseases, Azienda Ospedaliero Universitaria Senese, Siena, Italy
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3
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Ruiz A, Benucci S, Duthaler U, Bachmann C, Franchini M, Noreen F, Pietrangelo L, Protasi F, Treves S, Zorzato F. Improvement of muscle strength in a mouse model for congenital myopathy treated with HDAC and DNA methyltransferase inhibitors. eLife 2022; 11:73718. [PMID: 35238775 PMCID: PMC8956288 DOI: 10.7554/elife.73718] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 02/18/2022] [Indexed: 11/13/2022] Open
Abstract
To date there are no therapies for patients with congenital myopathies, muscle disorders causing poor quality of life of affected individuals. In approximately 30% of the cases, patients with congenital myopathies carry either dominant or recessive mutations in the RYR1 gene; recessive RYR1 mutations are accompanied by reduction of RyR1 expression and content in skeletal muscles and are associated with fiber hypotrophy and muscle weakness. Importantly, muscles of patients with recessive RYR1 mutations exhibit increased content of class II histone de-acetylases and of DNA genomic methylation. We recently created a mouse model knocked-in for the p.Q1970fsX16+p.A4329D RyR1 mutations, which are isogenic to those carried by a severely affected child suffering from a recessive form of RyR1-related multi-mini core disease. The phenotype of the RyR1 mutant mice recapitulates many aspects of the clinical picture of patients carrying recessive RYR1 mutations. We treated the compound heterozygous mice with a combination of two drugs targeting DNA methylases and class II histone de-acetylases. Here we show that treatment of the mutant mice with drugs targeting epigenetic enzymes improves muscle strength, RyR1 protein content and muscle ultrastructure. This study provides proof of concept for the pharmacological treatment of patients with congenital myopathies linked to recessive RYR1 mutations.
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Affiliation(s)
- Alexis Ruiz
- Department of Biomedicine, Basel University Hospital, Basel, Switzerland
| | - Sofia Benucci
- Department of Biomedicine, Basel University Hospital, Basel, Switzerland
| | - Urs Duthaler
- Department of Biomedicine, Basel University Hospital, Basel, Switzerland
| | - Christoph Bachmann
- Department of Biomedicine, Basel University Hospital, Basel, Switzerland
| | - Martina Franchini
- Department of Biomedicine, Basel University Hospital, Basel, Switzerland
| | - Faiza Noreen
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Laura Pietrangelo
- Department of Neuroscience, Imaging and Clinical Science, University G d' Annunzio of Chieti, Chieti, Italy
| | - Feliciano Protasi
- Department of Neuroscience, Imaging and Clinical Science, University G d' Annunzio of Chieti, Chieti, Italy
| | - Susan Treves
- Department of Biomedicine, Basel University Hospital, Basel, Switzerland
| | - Francesco Zorzato
- Department of Biomedicine, Basel University Hospital, Basel, Switzerland
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Michelucci A, Liang C, Protasi F, Dirksen RT. Altered Ca 2+ Handling and Oxidative Stress Underlie Mitochondrial Damage and Skeletal Muscle Dysfunction in Aging and Disease. Metabolites 2021; 11:metabo11070424. [PMID: 34203260 PMCID: PMC8304741 DOI: 10.3390/metabo11070424] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/22/2021] [Accepted: 06/24/2021] [Indexed: 12/26/2022] Open
Abstract
Skeletal muscle contraction relies on both high-fidelity calcium (Ca2+) signals and robust capacity for adenosine triphosphate (ATP) generation. Ca2+ release units (CRUs) are highly organized junctions between the terminal cisternae of the sarcoplasmic reticulum (SR) and the transverse tubule (T-tubule). CRUs provide the structural framework for rapid elevations in myoplasmic Ca2+ during excitation-contraction (EC) coupling, the process whereby depolarization of the T-tubule membrane triggers SR Ca2+ release through ryanodine receptor-1 (RyR1) channels. Under conditions of local or global depletion of SR Ca2+ stores, store-operated Ca2+ entry (SOCE) provides an additional source of Ca2+ that originates from the extracellular space. In addition to Ca2+, skeletal muscle also requires ATP to both produce force and to replenish SR Ca2+ stores. Mitochondria are the principal intracellular organelles responsible for ATP production via aerobic respiration. This review provides a broad overview of the literature supporting a role for impaired Ca2+ handling, dysfunctional Ca2+-dependent production of reactive oxygen/nitrogen species (ROS/RNS), and structural/functional alterations in CRUs and mitochondria in the loss of muscle mass, reduction in muscle contractility, and increase in muscle damage in sarcopenia and a wide range of muscle disorders including muscular dystrophy, rhabdomyolysis, central core disease, and disuse atrophy. Understanding the impact of these processes on normal muscle function will provide important insights into potential therapeutic targets designed to prevent or reverse muscle dysfunction during aging and disease.
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Affiliation(s)
- Antonio Michelucci
- DNICS, Department of Neuroscience, Imaging, and Clinical Sciences, University G. d’Annunzio of Chieti-Pescara, I-66100 Chieti, Italy
- Correspondence:
| | - Chen Liang
- Department of Pharmacology and Physiology, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA; (C.L.); (R.T.D.)
| | - Feliciano Protasi
- CAST, Center for Advanced Studies and Technology, DMSI, Department of Medicine and Aging Sciences, University G. d’Annunzio of Chieti-Pescara, I-66100 Chieti, Italy;
| | - Robert T. Dirksen
- Department of Pharmacology and Physiology, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA; (C.L.); (R.T.D.)
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Gherardi G, De Mario A, Mammucari C. The mitochondrial calcium homeostasis orchestra plays its symphony: Skeletal muscle is the guest of honor. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2021; 362:209-259. [PMID: 34253296 DOI: 10.1016/bs.ircmb.2021.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
Abstract
Skeletal muscle mitochondria are placed in close proximity of the sarcoplasmic reticulum (SR), the main intracellular Ca2+ store. During muscle activity, excitation of sarcolemma and of T-tubule triggers the release of Ca2+ from the SR initiating myofiber contraction. The rise in cytosolic Ca2+ determines the opening of the mitochondrial calcium uniporter (MCU), the highly selective channel of the inner mitochondrial membrane (IMM), causing a robust increase in mitochondrial Ca2+ uptake. The Ca2+-dependent activation of TCA cycle enzymes increases the synthesis of ATP required for SERCA activity. Thus, Ca2+ is transported back into the SR and cytosolic [Ca2+] returns to resting levels eventually leading to muscle relaxation. In recent years, thanks to the molecular identification of MCU complex components, the role of mitochondrial Ca2+ uptake in the pathophysiology of skeletal muscle has been uncovered. In this chapter, we will introduce the reader to a general overview of mitochondrial Ca2+ accumulation. We will tackle the key molecular players and the cellular and pathophysiological consequences of mitochondrial Ca2+ dyshomeostasis. In the second part of the chapter, we will discuss novel findings on the physiological role of mitochondrial Ca2+ uptake in skeletal muscle. Finally, we will examine the involvement of mitochondrial Ca2+ signaling in muscle diseases.
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Affiliation(s)
- Gaia Gherardi
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Agnese De Mario
- Department of Biomedical Sciences, University of Padua, Padua, Italy
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6
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Structural basis for diamide modulation of ryanodine receptor. Nat Chem Biol 2020; 16:1246-1254. [DOI: 10.1038/s41589-020-0627-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 07/01/2020] [Indexed: 12/25/2022]
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Lawal TA, Wires ES, Terry NL, Dowling JJ, Todd JJ. Preclinical model systems of ryanodine receptor 1-related myopathies and malignant hyperthermia: a comprehensive scoping review of works published 1990-2019. Orphanet J Rare Dis 2020; 15:113. [PMID: 32381029 PMCID: PMC7204063 DOI: 10.1186/s13023-020-01384-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 04/14/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Pathogenic variations in the gene encoding the skeletal muscle ryanodine receptor (RyR1) are associated with malignant hyperthermia (MH) susceptibility, a life-threatening hypermetabolic condition and RYR1-related myopathies (RYR1-RM), a spectrum of rare neuromuscular disorders. In RYR1-RM, intracellular calcium dysregulation, post-translational modifications, and decreased protein expression lead to a heterogenous clinical presentation including proximal muscle weakness, contractures, scoliosis, respiratory insufficiency, and ophthalmoplegia. Preclinical model systems of RYR1-RM and MH have been developed to better understand underlying pathomechanisms and test potential therapeutics. METHODS We conducted a comprehensive scoping review of scientific literature pertaining to RYR1-RM and MH preclinical model systems in accordance with the PRISMA Scoping Reviews Checklist and the framework proposed by Arksey and O'Malley. Two major electronic databases (PubMed and EMBASE) were searched without language restriction for articles and abstracts published between January 1, 1990 and July 3, 2019. RESULTS Our search yielded 5049 publications from which 262 were included in this review. A majority of variants tested in RYR1 preclinical models were localized to established MH/central core disease (MH/CCD) hot spots. A total of 250 unique RYR1 variations were reported in human/rodent/porcine models with 95% being missense substitutions. The most frequently reported RYR1 variant was R614C/R615C (human/porcine total n = 39), followed by Y523S/Y524S (rabbit/mouse total n = 30), I4898T/I4897T/I4895T (human/rabbit/mouse total n = 20), and R163C/R165C (human/mouse total n = 18). The dyspedic mouse was utilized by 47% of publications in the rodent category and its RyR1-null (1B5) myotubes were transfected in 23% of publications in the cellular model category. In studies of transfected HEK-293 cells, 57% of RYR1 variations affected the RyR1 channel and activation core domain. A total of 15 RYR1 mutant mouse strains were identified of which ten were heterozygous, three were compound heterozygous, and a further two were knockout. Porcine, avian, zebrafish, C. elegans, canine, equine, and drosophila model systems were also reported. CONCLUSIONS Over the past 30 years, there were 262 publications on MH and RYR1-RM preclinical model systems featuring more than 200 unique RYR1 variations tested in a broad range of species. Findings from these studies have set the foundation for therapeutic development for MH and RYR1-RM.
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Affiliation(s)
- Tokunbor A Lawal
- National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Emily S Wires
- National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA
| | - Nancy L Terry
- National Institutes of Health Library, National Institutes of Health, Bethesda, MD, USA
| | - James J Dowling
- Program for Genetics and Genome Biology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Joshua J Todd
- National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, 20892, USA.
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Avnon T, Svirsky R, Orr-Urtreger A, Sagie L, Fattal-Valevski A, Fellig Y, Ben-Shachar S. Clinical Observation: Effect of a Second Transpositioned Variant in a Family with Autosomal Dominant Ryanodine Receptor-1-Related Disease. J Pediatr Genet 2019; 9:121-124. [PMID: 32341817 DOI: 10.1055/s-0039-1698445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 09/05/2019] [Indexed: 10/25/2022]
Abstract
Mutations in the ryanodine receptor-1 ( RYR1 ) may cause disorders inherited in an autosomal dominant/recessive fashion. Sequencing of RYR1 in an infant of Ashkenazi Jewish descent with severe hypotonia, dislocation of hip, torticollis and scoliosis, and paternal family history of autosomal dominant mild disease. The child was compound heterozygote for a missense variant c.7042G > A inherited from her father associated with autosomal dominant disease, and a missense variant of unknown significance c.5309C > T inherited from an asymptomatic mother. This case raises the possibility of a dominant disease complicated by a second variant in the other allele serving as a modifier.
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Affiliation(s)
- Tomer Avnon
- Department of Obstetrics and Gynecology, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ran Svirsky
- Genetics Institute, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Avi Orr-Urtreger
- Genetics Institute, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Liora Sagie
- Pediatric Neurology Institute, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Aviva Fattal-Valevski
- Pediatric Neurology Institute, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yakov Fellig
- Department of Pathology, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Shay Ben-Shachar
- Genetics Institute, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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9
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Parker R, Schiemann AH, Langton E, Bulger T, Pollock N, Bjorksten A, Gillies R, Hutchinson D, Roxburgh R, Stowell KM. Functional Characterization of C-terminal Ryanodine Receptor 1 Variants Associated with Central Core Disease or Malignant Hyperthermia. J Neuromuscul Dis 2019; 4:147-158. [PMID: 28527222 PMCID: PMC5467713 DOI: 10.3233/jnd-170210] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Background: Central core disease and malignant hyperthermia are human disorders of skeletal muscle resulting from aberrant Ca2+ handling. Most malignant hyperthermia and central core disease cases are associated with amino acid changes in the type 1 ryanodine receptor (RyR1), the skeletal muscle Ca2+-release channel. Malignant hyperthermia exhibits a gain-of-function phenotype, and central core disease results from loss of channel function. For a variant to be classified as pathogenic, functional studies must demonstrate a correlation with the pathophysiology of malignant hyperthermia or central core disease. Objective: We assessed the pathogenicity of four C-terminal variants of the ryanodine receptor using functional analysis. The variants were identified in families affected by either malignant hyperthermia or central core disease. Methods: Four variants were introduced separately into human cDNA encoding the skeletal muscle ryanodine receptor. Following transient expression in HEK-293T cells, functional studies were carried out using calcium release assays in response to an agonist. Two previously characterized variants and wild-type skeletal muscle ryanodine receptor were used as controls. Results: The p.Met4640Ile variant associated with central core disease showed no difference in calcium release compared to wild-type. The p.Val4849Ile variant associated with malignant hyperthermia was more sensitive to agonist than wild-type but did not reach statistical significance and two variants (p.Phe4857Ser and p.Asp4918Asn) associated with central core disease were completely inactive. Conclusions: The p.Val4849Ile variant should be considered a risk factor for malignant hyperthermia, while the p.Phe4857Ser and p.Asp4918Asn variants should be classified as pathogenic for central core disease.
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Affiliation(s)
- Remai Parker
- Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Anja H Schiemann
- Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | | | - Terasa Bulger
- Department of Anaesthesia and Intensive Care, Palmerston North Hospital, Palmerston North, New Zealand
| | - Neil Pollock
- Department of Anaesthesia and Intensive Care, Palmerston North Hospital, Palmerston North, New Zealand
| | - Andrew Bjorksten
- Department of Anaesthesia and Pain Management, Royal Melbourne Hospital, Melbourne
| | - Robyn Gillies
- Department of Anaesthesia and Pain Management, Royal Melbourne Hospital, Melbourne
| | - David Hutchinson
- Department of Neurology, Auckland City Hospital, Auckland, New Zealand
| | - Richard Roxburgh
- Department of Neurology, Auckland City Hospital, Auckland, New Zealand
| | - Kathryn M Stowell
- Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
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10
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RYR1 Sequence Variants in Myopathies: Expression and Functional Studies in Two Families. BIOMED RESEARCH INTERNATIONAL 2019; 2019:7638946. [PMID: 31165076 PMCID: PMC6500691 DOI: 10.1155/2019/7638946] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 03/19/2019] [Indexed: 12/26/2022]
Abstract
The skeletal muscle ryanodine receptor (RyR1), i.e., the Ca2+ channel of the sarco/endoplasmic reticulum (S/ER), and the voltage-dependent calcium channel Cav1.1 are the principal channels involved in excitation-contraction coupling in skeletal muscle. RYR1 gene variants are linked to distinct skeletal muscle disorders, including malignant hyperthermia susceptibility and central core disease (CCD), mainly with autosomal dominant inheritance, and autosomal recessive myopathies with a broad phenotypic and histopathological spectrum. The age at onset of RYR1-related myopathies varies from infancy to adulthood. We report the identification of four RYR1 variants in two Italian families: one with myopathy and variants c.4003C>T (p.R1335C) and c.7035C>A (p.S2345R), and another with CCD and variants c.9293G>T (p.S3098I) and c.14771_14772insTAGACAGGGTGTTGCTCTGTTGCCCTTCTT (p.F4924_V4925insRQGVALLPFF). We demonstrate that, in patient-specific lymphoblastoid cells, the c.4003C>T (p.R1335C) variant is not expressed and the in-frame 30-nucleotide insertion variant is expressed at a low level. Moreover, Ca2+ release in response to the RyR1 agonist 4-chloro-m-cresol and to thapsigargin showed that the c.7035C>A (p.S2345R) variant causes depletion of S/ER Ca2+ stores and that the compound heterozygosity for variant c.9293G>T (p.S3098I) and the 30-nucleotide insertion increases RyR1-dependent Ca2+ release without affecting ER Ca2+ stores. In conclusion, we detected and functionally characterized disease-causing variants of the RyR1 channel in patient-specific lymphoblastoid cells. This paper is dedicated to the memory and contribution of Luigi Del Vecchio.
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11
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Pancaroglu R, Van Petegem F. Calcium Channelopathies: Structural Insights into Disorders of the Muscle Excitation–Contraction Complex. Annu Rev Genet 2018; 52:373-396. [DOI: 10.1146/annurev-genet-120417-031311] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Ion channels are membrane proteins responsible for the passage of ions down their electrochemical gradients and across biological membranes. In this, they generate and shape action potentials and provide secondary messengers for various signaling pathways. They are often part of larger complexes containing auxiliary subunits and regulatory proteins. Channelopathies arise from mutations in the genes encoding ion channels or their associated proteins. Recent advances in cryo-electron microscopy have resulted in an explosion of ion channel structures in multiple states, generating a wealth of new information on channelopathies. Disease-associated mutations fall into different categories, interfering with ion permeation, protein folding, voltage sensing, ligand and protein binding, and allosteric modulation of channel gating. Prime examples of these are Ca2+-selective channels expressed in myocytes, for which multiple structures in distinct conformational states have recently been uncovered. We discuss the latest insights into these calcium channelopathies from a structural viewpoint.
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Affiliation(s)
- Raika Pancaroglu
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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12
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Murayama T, Kurebayashi N, Ogawa H, Yamazawa T, Oyamada H, Suzuki J, Kanemaru K, Oguchi K, Iino M, Sakurai T. Genotype-Phenotype Correlations of Malignant Hyperthermia and Central Core Disease Mutations in the Central Region of the RYR1 Channel. Hum Mutat 2016; 37:1231-1241. [PMID: 27586648 DOI: 10.1002/humu.23072] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 08/29/2016] [Indexed: 01/05/2023]
Abstract
Type 1 ryanodine receptor (RYR1) is a Ca2+ release channel in the sarcoplasmic reticulum of skeletal muscle and is mutated in some muscle diseases, including malignant hyperthermia (MH) and central core disease (CCD). Over 200 mutations associated with these diseases have been identified, and most mutations accelerate Ca2+ -induced Ca2+ release (CICR), resulting in abnormal Ca2+ homeostasis in skeletal muscle. However, it remains largely unknown how specific mutations cause different phenotypes. In this study, we investigated the CICR activity of 14 mutations at 10 different positions in the central region of RYR1 (10 MH and four MH/CCD mutations) using a heterologous expression system in HEK293 cells. In live-cell Ca2+ imaging, the mutant channels exhibited an enhanced sensitivity to caffeine, a reduced endoplasmic reticulum Ca2+ content, and an increased resting cytoplasmic Ca2+ level. The three parameters for CICR (Ca2+ sensitivity for activation, Ca2+ sensitivity for inactivation, and attainable maximum activity, i.e., gain) were obtained by [3 H]ryanodine binding and fitting analysis. The mutant channels showed increased gain and Ca2+ sensitivity for activation in a site-specific manner. Genotype-phenotype correlations were explained well by the near-atomic structure of RYR1. Our data suggest that divergent CICR activity may cause various disease phenotypes by specific mutations.
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Affiliation(s)
- Takashi Murayama
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan.
| | - Nagomi Kurebayashi
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Haruo Ogawa
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, Japan
| | - Toshiko Yamazawa
- Department of Molecular Physiology, Jikei University School of Medicine, Tokyo, Japan
| | - Hideto Oyamada
- Department of Pharmacology, School of Medicine, Showa University, Tokyo, Japan
| | - Junji Suzuki
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kazunori Kanemaru
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Katsuji Oguchi
- Department of Pharmacology, School of Medicine, Showa University, Tokyo, Japan
| | - Masamitsu Iino
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Takashi Sakurai
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan
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13
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Ríos E, Figueroa L, Manno C, Kraeva N, Riazi S. The couplonopathies: A comparative approach to a class of diseases of skeletal and cardiac muscle. ACTA ACUST UNITED AC 2016; 145:459-74. [PMID: 26009541 PMCID: PMC4442791 DOI: 10.1085/jgp.201411321] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A novel category of diseases of striated muscle is proposed, the couplonopathies, as those that affect components of the couplon and thereby alter its operation. Couplons are the functional units of intracellular calcium release in excitation–contraction coupling. They comprise dihydropyridine receptors, ryanodine receptors (Ca2+ release channels), and a growing list of ancillary proteins whose alteration may lead to disease. Within a generally similar plan, the couplons of skeletal and cardiac muscle show, in a few places, marked structural divergence associated with critical differences in the mechanisms whereby they fulfill their signaling role. Most important among these are the presence of a mechanical or allosteric communication between voltage sensors and Ca2+ release channels, exclusive to the skeletal couplon, and the smaller capacity of the Ca stores in cardiac muscle, which results in greater swings of store concentration during physiological function. Consideration of these structural and functional differences affords insights into the pathogenesis of several couplonopathies. The exclusive mechanical connection of the skeletal couplon explains differences in pathogenesis between malignant hyperthermia (MH) and catecholaminergic polymorphic ventricular tachycardia (CPVT), conditions most commonly caused by mutations in homologous regions of the skeletal and cardiac Ca2+ release channels. Based on mechanistic considerations applicable to both couplons, we identify the plasmalemma as a site of secondary modifications, typically an increase in store-operated calcium entry, that are relevant in MH pathogenesis. Similar considerations help explain the different consequences that mutations in triadin and calsequestrin have in these two tissues. As more information is gathered on the composition of cardiac and skeletal couplons, this comparative and mechanistic approach to couplonopathies should be useful to understand pathogenesis, clarify diagnosis, and propose tissue-specific drug development.
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Affiliation(s)
- Eduardo Ríos
- Section of Cellular Signaling, Department of Molecular Biophysics and Physiology, Rush University, Chicago, IL 60612
| | - Lourdes Figueroa
- Section of Cellular Signaling, Department of Molecular Biophysics and Physiology, Rush University, Chicago, IL 60612
| | - Carlo Manno
- Section of Cellular Signaling, Department of Molecular Biophysics and Physiology, Rush University, Chicago, IL 60612
| | - Natalia Kraeva
- Malignant Hyperthermia Investigation Unit, University Health Network, Toronto General Hospital, Toronto, Ontario M5G 2C4, Canada
| | - Sheila Riazi
- Malignant Hyperthermia Investigation Unit, University Health Network, Toronto General Hospital, Toronto, Ontario M5G 2C4, Canada
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14
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Lazier J, Mah JK, Nikolic A, Wei XC, Samedi V, Fajardo C, Brindle M, Perrier R, Thomas MA. Bilateral congenital lumbar hernias in a patient with central core disease--A case report. Neuromuscul Disord 2015; 26:56-9. [PMID: 26684984 DOI: 10.1016/j.nmd.2015.10.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 08/31/2015] [Accepted: 10/29/2015] [Indexed: 01/05/2023]
Abstract
Congenital lumbar hernias are rare malformations caused by defects in the development of the posterior abdominal wall. A known association exists with lumbocostovertebral syndrome; however other associated anomalies, including one case with arthrogryposis, have been previously reported. We present an infant girl with bilateral congenital lumbar hernias, multiple joint contractures, decreased muscle bulk and symptoms of malignant hyperthermia. Molecular testing revealed an R4861C mutation in the ryanodine receptor 1 (RYR1) gene, known to be associated with central core disease. This is the first reported case of the co-occurrence of congenital lumbar hernias and central core disease. We hypothesize that ryanodine receptor 1 mutations may interrupt muscle differentiation and development. Further, this case suggests an expansion of the ryanodine receptor 1-related myopathy phenotype to include congenital lumbar hernias.
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Affiliation(s)
- Joanna Lazier
- Department of Medical Genetics, Alberta Children's Hospital, Calgary, Alberta, Canada.
| | - Jean K Mah
- Section of Neurology, Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Ana Nikolic
- Division of Neuropathology, Department of Pathology and Laboratory Medicine, University of Calgary and Calgary Laboratory Services, Calgary, Alberta, Canada
| | - Xing-Chang Wei
- Diagnostic Imaging, Alberta Children's Hospital, Calgary, Alberta, Canada
| | - Veronica Samedi
- Division of Neonatology, Department of Pediatrics, University of Calgary, Calgary, Alberta, Canada
| | - Carlos Fajardo
- Division of Neonatology, Department of Pediatrics, University of Calgary, Calgary, Alberta, Canada; Department of Pediatrics, University of Calgary, Calgary, Alberta, Canada
| | - Mary Brindle
- Department of Surgery, Alberta Children's Hospital, University of Calgary, Calgary, Alberta, Canada
| | - Renee Perrier
- Department of Medical Genetics, Alberta Children's Hospital, Calgary, Alberta, Canada; Department of Pediatrics, University of Calgary, Calgary, Alberta, Canada
| | - Mary Ann Thomas
- Department of Medical Genetics, Alberta Children's Hospital, Calgary, Alberta, Canada; Department of Pediatrics, University of Calgary, Calgary, Alberta, Canada
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15
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Murayama T, Kurebayashi N, Yamazawa T, Oyamada H, Suzuki J, Kanemaru K, Oguchi K, Iino M, Sakurai T. Divergent Activity Profiles of Type 1 Ryanodine Receptor Channels Carrying Malignant Hyperthermia and Central Core Disease Mutations in the Amino-Terminal Region. PLoS One 2015; 10:e0130606. [PMID: 26115329 PMCID: PMC4482644 DOI: 10.1371/journal.pone.0130606] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 05/21/2015] [Indexed: 11/25/2022] Open
Abstract
The type 1 ryanodine receptor (RyR1) is a Ca2+ release channel in the sarcoplasmic reticulum of skeletal muscle and is mutated in several diseases, including malignant hyperthermia (MH) and central core disease (CCD). Most MH and CCD mutations cause accelerated Ca2+ release, resulting in abnormal Ca2+ homeostasis in skeletal muscle. However, how specific mutations affect the channel to produce different phenotypes is not well understood. In this study, we have investigated 11 mutations at 7 different positions in the amino (N)-terminal region of RyR1 (9 MH and 2 MH/CCD mutations) using a heterologous expression system in HEK293 cells. In live-cell Ca2+ imaging at room temperature (~25 °C), cells expressing mutant channels exhibited alterations in Ca2+ homeostasis, i.e., an enhanced sensitivity to caffeine, a depletion of Ca2+ in the ER and an increase in resting cytoplasmic Ca2+. RyR1 channel activity was quantitatively evaluated by [3H]ryanodine binding and three parameters (sensitivity to activating Ca2+, sensitivity to inactivating Ca2+ and attainable maximum activity, i.e., gain) were obtained by fitting analysis. The mutations increased the gain and the sensitivity to activating Ca2+ in a site-specific manner. The gain was consistently higher in both MH and MH/CCD mutations. Sensitivity to activating Ca2+ was markedly enhanced in MH/CCD mutations. The channel activity estimated from the three parameters provides a reasonable explanation to the pathological phenotype assessed by Ca2+ homeostasis. These properties were also observed at higher temperatures (~37 °C). Our data suggest that divergent activity profiles may cause varied disease phenotypes by specific mutations. This approach should be useful for diagnosis and treatment of diseases with mutations in RyR1.
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Affiliation(s)
- Takashi Murayama
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo 113–8421, Japan
- * E-mail:
| | - Nagomi Kurebayashi
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo 113–8421, Japan
| | - Toshiko Yamazawa
- Department of Molecular Physiology, Jikei University School of Medicine, Tokyo 105–8461, Japan
| | - Hideto Oyamada
- Department of Pharmacology, School of Medicine, Showa University, Tokyo 142–8555, Japan
| | - Junji Suzuki
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo 113–0033, Japan
| | - Kazunori Kanemaru
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo 113–0033, Japan
| | - Katsuji Oguchi
- Department of Pharmacology, School of Medicine, Showa University, Tokyo 142–8555, Japan
| | - Masamitsu Iino
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo 113–0033, Japan
| | - Takashi Sakurai
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo 113–8421, Japan
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16
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Van Petegem F. Ryanodine Receptors: Allosteric Ion Channel Giants. J Mol Biol 2015; 427:31-53. [DOI: 10.1016/j.jmb.2014.08.004] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 08/02/2014] [Accepted: 08/05/2014] [Indexed: 01/27/2023]
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Seidel M, Thomas NL, Williams AJ, Lai FA, Zissimopoulos S. Dantrolene rescues aberrant N-terminus intersubunit interactions in mutant pro-arrhythmic cardiac ryanodine receptors. Cardiovasc Res 2014; 105:118-28. [PMID: 25411383 DOI: 10.1093/cvr/cvu240] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS The ryanodine receptor (RyR2) is an intracellular Ca(2+) release channel essential for cardiac excitation-contraction coupling. Abnormal RyR2 channel function results in the generation of arrhythmias and sudden cardiac death. The present study was undertaken to investigate the mechanistic basis of RyR2 dysfunction in inherited arrhythmogenic cardiac disease. METHODS AND RESULTS We present several lines of complementary evidence, indicating that the arrhythmia-associated L433P mutation disrupts RyR2 N-terminus self-association. A combination of yeast two-hybrid, co-immunoprecipitation, and chemical cross-linking assays collectively demonstrate that a RyR2 N-terminal fragment carrying the L433P mutation displays substantially reduced self-interaction compared with wild type. Moreover, sucrose density gradient centrifugation reveals that the L433P mutation impairs tetramerization of the full-length channel. [(3)H]Ryanodine-binding assays demonstrate that disrupted N-terminal intersubunit interactions within RyR2(L433P) confer an altered sensitivity to Ca(2+) activation. Calcium imaging of RyR2(L433P)-expressing cells reveals substantially prolonged Ca(2+) transients and reduced Ca(2+) store content indicating defective channel closure. Importantly, dantrolene treatment reverses the L433P mutation-induced impairment and restores channel function. CONCLUSION The N-terminus domain constitutes an important structural determinant for the functional oligomerization of RyR2. Our findings are consistent with defective N-terminus self-association as a molecular mechanism underlying RyR2 channel deregulation in inherited arrhythmogenic cardiac disease. Significantly, the therapeutic action of dantrolene may occur via the restoration of normal RyR2 N-terminal intersubunit interactions.
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Affiliation(s)
- Monika Seidel
- Wales Heart Research Institute, Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Cardiff CF14 4XN, UK
| | - N Lowri Thomas
- Wales Heart Research Institute, Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Cardiff CF14 4XN, UK
| | - Alan J Williams
- Wales Heart Research Institute, Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Cardiff CF14 4XN, UK
| | - F Anthony Lai
- Wales Heart Research Institute, Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Cardiff CF14 4XN, UK
| | - Spyros Zissimopoulos
- Wales Heart Research Institute, Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Cardiff CF14 4XN, UK
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18
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Roesl C, Sato K, Schiemann A, Pollock N, Stowell KM. Functional characterisation of the R2452W ryanodine receptor variant associated with malignant hyperthermia susceptibility. Cell Calcium 2014; 56:195-201. [PMID: 25086907 DOI: 10.1016/j.ceca.2014.07.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 06/26/2014] [Accepted: 07/10/2014] [Indexed: 10/25/2022]
Abstract
Malignant hyperthermia (MH) is a pharmacogenetic disorder that manifests in susceptible individuals exposed to volatile anaesthetics. Over 400 variants in the ryanodine receptor 1 (RYR1) have been reported but relatively few have been definitively associated with susceptibility to MH. This is largely due to the technical challenges of demonstrating abnormal Ca(2+) release from the sarcoplasmic reticulum. This study focuses on the R2452W variant and its functional characterisation with the aim of classifying this variant as MH causative. HEK293 cells were transiently transfected with full-length human wildtype or R2452W mutant RYR1 cDNA. In addition, B-lymphoblastoid cells from blood and myoblasts propagated from in vitro contracture tests were extracted from patients positive for the R2452W variant. All cell lines generated were loaded with the ratiometric dye Fura-2 AM, stimulated with the RYR1-specific agonist 4-chloro-m-cresol and Ca(2+) release from the sarcoplasmic/endoplasmic reticulum was monitored by fluorescence emission. All cells expressing the RYR1 R2452W variant show a significantly higher Ca(2+) release in response to the agonist, 4-chloro-m-cresol, compared to cells expressing RYR1 WT. These results indicate that the R2452W variant results in a hypersensitive ryanodine receptor 1 and suggest that the R2452W variant in the ryanodine receptor 1 is likely to be causative of MH.
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Affiliation(s)
- Cornelia Roesl
- Centre for Reproductive Health, University of Edinburgh, Edinburgh, United Kingdom
| | - Keisaku Sato
- Department of Medicine, University of Florida, Gainesville, FL, United States
| | - Anja Schiemann
- Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Neil Pollock
- Department of Anaesthesia and Intensive Care, Palmerston North Hospital, Palmerstion North, New Zealand
| | - Kathryn M Stowell
- Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand.
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Guerrero-Hernández A, Ávila G, Rueda A. Ryanodine receptors as leak channels. Eur J Pharmacol 2013; 739:26-38. [PMID: 24291096 DOI: 10.1016/j.ejphar.2013.11.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 11/21/2013] [Indexed: 01/18/2023]
Abstract
Ryanodine receptors are Ca(2+) release channels of internal stores. This review focuses on those situations and conditions that transform RyRs from a finely regulated ion channel to an unregulated Ca(2+) leak channel and the pathological consequences of this alteration. In skeletal muscle, mutations in either CaV1.1 channel or RyR1 results in a leaky behavior of the latter. In heart cells, RyR2 functions normally as a Ca(2+) leak channel during diastole within certain limits, the enhancement of this activity leads to arrhythmogenic situations that are tackled with different pharmacological strategies. In smooth muscle, RyRs are involved more in reducing excitability than in stimulating contraction so the leak activity of RyRs in the form of Ca(2+) sparks, locally activates Ca(2+)-dependent potassium channels to reduce excitability. In neurons the enhanced activity of RyRs is associated with the development of different neurodegenerative disorders such as Alzheimer and Huntington diseases. It appears then that the activity of RyRs as leak channels can have both physiological and pathological consequences depending on the cell type and the metabolic condition.
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Affiliation(s)
| | | | - Angélica Rueda
- Departamento de Bioquímica, Cinvestav, Mexico city, México
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20
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Lefebvre R, Legrand C, Groom L, Dirksen RT, Jacquemond V. Ca2+ release in muscle fibers expressing R4892W and G4896V type 1 ryanodine receptor disease mutants. PLoS One 2013; 8:e54042. [PMID: 23308296 PMCID: PMC3538700 DOI: 10.1371/journal.pone.0054042] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Accepted: 12/05/2012] [Indexed: 12/17/2022] Open
Abstract
The large and rapidly increasing number of potentially pathological mutants in the type 1 ryanodine receptor (RyR1) prompts the need to characterize their effects on voltage-activated sarcoplasmic reticulum (SR) Ca2+ release in skeletal muscle. Here we evaluated the function of the R4892W and G4896V RyR1 mutants, both associated with central core disease (CCD) in humans, in myotubes and in adult muscle fibers. For both mutants expressed in RyR1-null (dyspedic) myotubes, voltage-gated Ca2+ release was absent following homotypic expression and only partially restored following heterotypic expression with wild-type (WT) RyR1. In muscle fibers from adult WT mice, both mutants were expressed in restricted regions of the fibers with a pattern consistent with triadic localization. Voltage-clamp-activated confocal Ca2+ signals showed that fiber regions endowed with G4896V-RyR1s exhibited an ∼30% reduction in the peak rate of SR Ca2+ release, with no significant change in SR Ca2+ content. Immunostaining revealed no associated change in the expression of either α1S subunit (Cav1.1) of the dihydropyridine receptor (DHPR) or type 1 sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA1), indicating that the reduced Ca2+ release resulted from defective RyR1 function. Interestingly, in spite of robust localized junctional expression, the R4892W mutant did not affect SR Ca2+ release in adult muscle fibers, consistent with a low functional penetrance of this particular CCD-associated mutant.
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Affiliation(s)
- Romain Lefebvre
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, CNRS UMR 5534 – Université Lyon 1, Villeurbanne, France
| | - Claude Legrand
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, CNRS UMR 5534 – Université Lyon 1, Villeurbanne, France
| | - Linda Groom
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, New York, United States of America
| | - Robert T. Dirksen
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, New York, United States of America
| | - Vincent Jacquemond
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, CNRS UMR 5534 – Université Lyon 1, Villeurbanne, France
- * E-mail:
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21
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Kimlicka L, Lau K, Tung CC, Van Petegem F. Disease mutations in the ryanodine receptor N-terminal region couple to a mobile intersubunit interface. Nat Commun 2013; 4:1506. [PMID: 23422674 PMCID: PMC3586727 DOI: 10.1038/ncomms2501] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 01/15/2013] [Indexed: 11/14/2022] Open
Abstract
Ryanodine receptors are large channels that release Ca(2+) from the endoplasmic and sarcoplasmic reticulum. Hundreds of RyR mutations can cause cardiac and skeletal muscle disorders, yet detailed mechanisms explaining their effects have been lacking. Here we compare pseudo-atomic models and propose that channel opening coincides with widening of a cytoplasmic vestibule formed by the N-terminal region, thus altering an interface targeted by 20 disease mutations. We solve crystal structures of several disease mutants that affect intrasubunit domain-domain interfaces. Mutations affecting intrasubunit ionic pairs alter relative domain orientations, and thus couple to surrounding interfaces. Buried disease mutations cause structural changes that also connect to the intersubunit contact area. These results suggest that the intersubunit contact region between N-terminal domains is a prime target for disease mutations, direct or indirect, and we present a model whereby ryanodine receptors and inositol-1,4,5-trisphosphate receptors are activated by altering domain arrangements in the N-terminal region.
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Affiliation(s)
- Lynn Kimlicka
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Kelvin Lau
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Ching-Chieh Tung
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
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Kraeva N, Zvaritch E, Rossi AE, Goonasekera SA, Zaid H, Frodis W, Kraev A, Dirksen RT, Maclennan DH, Riazi S. Novel excitation-contraction uncoupled RYR1 mutations in patients with central core disease. Neuromuscul Disord 2012. [PMID: 23183335 DOI: 10.1016/j.nmd.2012.08.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Central core disease, one of the most common congenital myopathies in humans, has been linked to mutations in the RYR1 gene encoding the Ca(2+) release channel of the sarcoplasmic reticulum (RyR1). Functional analyses showed that disease-associated RYR1 mutations led to impairment of skeletal muscle Ca(2+) homeostasis; however, thorough understanding of the molecular mechanisms underlying central core disease and other RyR1-related conditions is still lacking. We screened by sequencing the complete RYR1 transcripts in ten unrelated patients with central core disease and identified five novel, p.M4640R, p.L4647P, p.F4808L, p.D4918N and p.F4941C, and four recurrent mutations. Four of the novel mutations involved amino acid residues that were positioned within putative transmembrane segments of the RyR1. The pathogenic character of the identified mutations was demonstrated by bioinformatic analyses and by the in vitro functional studies in HEK293 cells and RYR1-null (dyspedic) myotubes. Characterization of Ca(2+) channel properties of RyR1s carrying one recurrent and two novel mutations upholds the view that diminished intracellular Ca(2+) release caused by impaired Ca(2+) channel gating and/or Ca(2+) permeability is an important component of central core disease etiology. This study expands the list of functionally characterized disease-associated RyR1 mutations, increasing the value of genetic diagnosis for RyR1-related disorders.
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Affiliation(s)
- Natalia Kraeva
- Malignant Hyperthermia Investigation Unit, Toronto General Hospital, University Health Network, Toronto, ON, Canada M5G 2C4
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Lefebvre R, Legrand C, González-Rodríguez E, Groom L, Dirksen RT, Jacquemond V. Defects in Ca2+ release associated with local expression of pathological ryanodine receptors in mouse muscle fibres. J Physiol 2011; 589:5361-82. [PMID: 21969454 DOI: 10.1113/jphysiol.2011.216408] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Mutations of the gene encoding the type 1 ryanodine receptor (RyR1) are associated with skeletal muscle disorders including malignant hyperthermia susceptibility (MHS) and central core disease (CCD). We used in vivo expression of EGFP-RyR1 constructs in fully differentiated mouse muscle fibres to characterize the function of several RyR1 mutants. Wild-type and Y523S, R615C, R2163H and I4897T mutants of RyR1 were separately expressed and found to be present within restricted regions of fibres with a pattern consistent with triadic localization. Confocal measurements of voltage-clamp-activated myoplasmic Ca(2+) transients demonstrated alterations of sarcoplasmic reticulum (SR) Ca(2+) release spatially correlated with the presence of exogenous RyR1s. The Y523S, R615C and R2163H RyR1 MHS-related mutants were associated with enhanced peak Ca(2+) release for low and moderate levels of depolarization, whereas the I4897T CCD mutant produced a chronic reduction of peak SR Ca(2+) release. For example, peak Ca(2+) release in response to a depolarization to -20 mV in regions of fibres expressing Y523S and I4897T was 2.0 ± 0.3 (n = 9) and 0.46 ± 0.1 (n = 5) times the corresponding value in adjacent, non-expressing regions of the same fibre, respectively. Interestingly no significant change in the estimated total amount of Ca(2+) released at the end of large depolarizing pulses was observed for any of the mutant RyR1 channels. Overall, results are consistent with an 'inherent' increase in RyR1 sensitivity to activation by the voltage sensor for the MHS-related RyR1 mutants and a partial failure of voltage-gated release for the CCD-related I4897T mutant, that occur with no sign of change in SR Ca(2+) content. Furthermore, the results indicate that RyR1 channel density is tightly regulated even under the present conditions of forced exogenous expression.
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Affiliation(s)
- Romain Lefebvre
- CNRS UMR 5534, Université Lyon 1, Centre de Génétique et de Physiologie Moléculaire et Cellulaire, Villeurbanne, France
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Haraki T, Yasuda T, Mukaida K, Migita T, Hamada H, Kawamoto M. Mutated p.4894 RyR1 function related to malignant hyperthermia and congenital neuromuscular disease with uniform type 1 fiber (CNMDU1). Anesth Analg 2011; 113:1461-7. [PMID: 21926372 DOI: 10.1213/ane.0b013e318232053e] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Ryanodine receptor 1 (RyR1) is a Ca(2+) release channel located in the sarcoplasmic reticulum membrane of skeletal muscle. More than 200 variants in RyR1 have been identified in DNA from patients with malignant hyperthermia (MH) and congenital myopathies; only 30 have been sufficiently studied so as to be identified as MH-causative mutations. The Ala4894Thr RyR1 variant was found in a Japanese patient with susceptibility to MH, and the Ala4894Pro variant in a rare case of myopathy: congenital neuromuscular disease with uniform type 1 fiber (CNMDU1). We hypothesized that different Ala4894 variants of RyR1 cause different pathophysiological changes that are identifiable by having differing pharmacological sensitivities to RYR1 agonists. METHODS Expression vector with a mutation in RYR1 corresponding to the Ala4894Thr, Ala4894Pro, Ala4894Ser, or Ala 4894Gly variant of human RyR1 was transfected into human embryonic kidney 293 cells. At 72 hours after transfection, we determined the intracellular Ca(2+) changes induced by caffeine and 4-chloro-m-cresol (4CmC), in the presence or absence of dantrolene. RESULTS Ala4894Thr-transfected cells and Ala4894Ser-transfected cells were more sensitive to caffeine than the wild type, and Ala4894Thr-transfected cells were also more sensitive to 4CmC than the wild type, whereas Ala4894Pro-transfected cells had no response to caffeine or 4CmC. Ala4894Gly-transfected cells were significantly less sensitive to caffeine than the wild type. In addition, the responses of Ala4894Thr-transfected cells and Ala4894Ser-transfected cells to caffeine were suppressed by dantrolene. CONCLUSION We concluded that different Ala4894 variants of RyR1 lead to different agonist/antagonist sensitivities, which may predict differing RYR1 functionality during excitation-contraction coupling and sensitivity to MH. The hypersensitive Ala4894Thr-RyR1 is associated with MH and the poorly functional Ala4894Pro-RyR1 with CNMDU1.
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Affiliation(s)
- Toshiaki Haraki
- Department of Anesthesiology and Critical Care, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan.
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Vega AV, Ramos-Mondragón R, Calderón-Rivera A, Zarain-Herzberg A, Avila G. Calcitonin gene-related peptide restores disrupted excitation-contraction coupling in myotubes expressing central core disease mutations in RyR1. J Physiol 2011; 589:4649-69. [PMID: 21825032 DOI: 10.1113/jphysiol.2011.210765] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Central core disease (CCD) is a congenital human myopathy associated with mutations in the gene encoding the skeletal muscle ryanodine receptor (RyR1), resulting in skeletal muscle weakness and lower limb deformities. The muscle weakness can be at least partially explained by a reduced magnitude of voltage-gated Ca(2+) release (VGCR). To date, only a few studies have focused on identifying potential therapeutic agents for CCD. Therefore, in this work we investigated the potential use of the calcitonin gene related peptide (CGRP) to restore VGCR in myotubes expressing CCD RyR1 mutants. We also examined the influence of CCD mutants on Ca(2+)-dependent processes involved in myogenesis (myoblast fusion and sarcoendoplasmic reticulum Ca(2+)-ATPase isoform 2 (SERCA2) gene expression). C2C12 cells were transfected with cDNAs encoding either wild-type RyR1 or CCD mutants, and then exposed to CGRP (100 nm, 1-4 h). Expression of the I4897T mutant significantly inhibited SERCA2 gene expression and myoblast fusion, whereas the Y523S mutant exerted the opposite effect. Interestingly, both mutants clearly inhibited VGCR (50%), due to a reduction in SR Ca(2+) content. However, no major changes due to CGRP or CCD mutants were observed in I(CaL). Our data suggest that the Y523S mutant results in store depletion via decompensated SR Ca(2+) leak, while the I4897T mutant inhibits SERCA2 gene expression. Remarkably, in both cases CGRP restored VGCR, likely to have been by enhancing phospholamban (PLB) phosphorylation, SERCA activity and SR Ca(2+) content. Taken together, our data show that in the C2C12 model system, changes in excitation-contraction coupling induced by the expression of RyR1 channels bearing CCD mutations Y523S or I4897T can be reversed by CGRP.
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MacLennan DH, Zvaritch E. Mechanistic models for muscle diseases and disorders originating in the sarcoplasmic reticulum. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:948-64. [DOI: 10.1016/j.bbamcr.2010.11.009] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Revised: 11/11/2010] [Accepted: 11/18/2010] [Indexed: 11/29/2022]
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Loy RE, Orynbayev M, Xu L, Andronache Z, Apostol S, Zvaritch E, MacLennan DH, Meissner G, Melzer W, Dirksen RT. Muscle weakness in Ryr1I4895T/WT knock-in mice as a result of reduced ryanodine receptor Ca2+ ion permeation and release from the sarcoplasmic reticulum. ACTA ACUST UNITED AC 2010; 137:43-57. [PMID: 21149547 PMCID: PMC3010056 DOI: 10.1085/jgp.201010523] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The type 1 isoform of the ryanodine receptor (RYR1) is the Ca(2+) release channel of the sarcoplasmic reticulum (SR) that is activated during skeletal muscle excitation-contraction (EC) coupling. Mutations in the RYR1 gene cause several rare inherited skeletal muscle disorders, including malignant hyperthermia and central core disease (CCD). The human RYR1(I4898T) mutation is one of the most common CCD mutations. To elucidate the mechanism by which RYR1 function is altered by this mutation, we characterized in vivo muscle strength, EC coupling, SR Ca(2+) content, and RYR1 Ca(2+) release channel function using adult heterozygous Ryr1(I4895T/+) knock-in mice (IT/+). Compared with age-matched wild-type (WT) mice, IT/+ mice exhibited significantly reduced upper body and grip strength. In spite of normal total SR Ca(2+) content, both electrically evoked and 4-chloro-m-cresol-induced Ca(2+) release were significantly reduced and slowed in single intact flexor digitorum brevis fibers isolated from 4-6-mo-old IT/+ mice. The sensitivity of the SR Ca(2+) release mechanism to activation was not enhanced in fibers of IT/+ mice. Single-channel measurements of purified recombinant channels incorporated in planar lipid bilayers revealed that Ca(2+) permeation was abolished for homotetrameric IT channels and significantly reduced for heterotetrameric WT:IT channels. Collectively, these findings indicate that in vivo muscle weakness observed in IT/+ knock-in mice arises from a reduction in the magnitude and rate of RYR1 Ca(2+) release during EC coupling that results from the mutation producing a dominant-negative suppression of RYR1 channel Ca(2+) ion permeation.
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Affiliation(s)
- Ryan E Loy
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
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Boncompagni S, Loy RE, Dirksen RT, Franzini-Armstrong C. The I4895T mutation in the type 1 ryanodine receptor induces fiber-type specific alterations in skeletal muscle that mimic premature aging. Aging Cell 2010; 9:958-70. [PMID: 20961389 DOI: 10.1111/j.1474-9726.2010.00623.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The I4898T (IT) mutation in type 1 ryanodine receptor (RyR1), the Ca(2+) release channel of the sarcoplasmic reticulum (SR) is linked to a form of central core disease (CCD) in humans and results in a nonleaky channel and excitation-contraction uncoupling. We characterized age-dependent and fiber-type-dependent alterations in muscle ultrastructure, as well as the magnitude and spatiotemporal properties of evoked Ca(2+) release in heterozygous Ryr1(I4895T/WT) (IT/+) knock-in mice on a mixed genetic background. The results indicate a classical but mild CCD phenotype that includes muscle weakness and the presence of mitochondrial-deficient areas in type I fibers. Electrically evoked Ca(2+) release is significantly reduced in single flexor digitorum brevis (FDB) fibers from young and old IT/+ mice. Structural changes are strongly fiber-type specific, affecting type I and IIB/IIX fibers in very distinct ways, and sparing type IIA fibers. Ultrastructural alterations in our IT/+ mice are also present in wild type, but at a lower frequency and older ages, suggesting that the disease mutation on the mixed background promotes an acceleration of normal age-dependent changes. The observed functional and structural alterations and their similarity to age-associated changes are entirely consistent with the known properties of the mutated channel, which result in reduced calcium release as is also observed in normal aging muscle. In strong contrast to these observations, a subset of patients with the analogous human heterozygous mutation and IT/+ mice on an inbred 129S2/SvPasCrl background exhibit a more severe disease phenotype, which is not directly consistent with the mutated channel properties.
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Affiliation(s)
- Simona Boncompagni
- IIM - Interuniversitary Institute of Myology, DNI - Department of Neuroscience and Imaging, Ce.S.I.- Centro Scienze dell'Invecchiamento, University of Studi G. d'Annunzio, 66013 Chieti, Italy.
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Treves S, Vukcevic M, Jeannet PY, Levano S, Girard T, Urwyler A, Fischer D, Voit T, Jungbluth H, Lillis S, Muntoni F, Quinlivan R, Sarkozy A, Bushby K, Zorzato F. Enhanced excitation-coupled Ca(2+) entry induces nuclear translocation of NFAT and contributes to IL-6 release from myotubes from patients with central core disease. Hum Mol Genet 2010; 20:589-600. [PMID: 21088110 DOI: 10.1093/hmg/ddq506] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Prolonged depolarization of skeletal muscle cells induces entry of extracellular calcium into muscle cells, an event referred to as excitation-coupled calcium entry. Skeletal muscle excitation-coupled calcium entry relies on the interaction between the 1,4-dihydropyridine receptor on the sarcolemma and the ryanodine receptor on the sarcoplasmic reticulum membrane. In this study, we directly measured excitation-coupled calcium entry by total internal reflection fluorescence microscopy in human skeletal muscle myotubes harbouring mutations in the RYR1 gene linked to malignant hyperthermia (MH) and central core disease (CCD). We found that excitation-coupled calcium entry is strongly enhanced in cells from patients with CCD compared with individuals with MH and controls. Furthermore, excitation-coupled calcium entry induces generation of reactive nitrogen species and enhances nuclear localization of NFATc1, which in turn may be responsible for the increased IL-6 released by myotubes from patients with CCD.
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Affiliation(s)
- Susan Treves
- Department of Anesthesia, Basel University Hospital, 4031 Basel, Switzerland.
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Wei L, Dirksen RT. Ryanodinopathies: RyR-Linked Muscle Diseases. CURRENT TOPICS IN MEMBRANES 2010; 66:139-67. [PMID: 22353479 DOI: 10.1016/s1063-5823(10)66007-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/24/2023]
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Bellinger AM, Mongillo M, Marks AR. Stressed out: the skeletal muscle ryanodine receptor as a target of stress. J Clin Invest 2008; 118:445-53. [PMID: 18246195 DOI: 10.1172/jci34006] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Over the past century, understanding the mechanisms underlying muscle fatigue and weakness has been the focus of much investigation. However, the dominant theory in the field, that lactic acidosis causes muscle fatigue, is unlikely to tell the whole story. Recently, dysregulation of sarcoplasmic reticulum (SR) Ca(2+) release has been associated with impaired muscle function induced by a wide range of stressors, from dystrophy to heart failure to muscle fatigue. Here, we address current understandings of the altered regulation of SR Ca(2+) release during chronic stress, focusing on the role of the SR Ca(2+) release channel known as the type 1 ryanodine receptor.
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Affiliation(s)
- Andrew M Bellinger
- Clyde and Helen Wu Center for Molecular Cardiology, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA
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Xu L, Wang Y, Yamaguchi N, Pasek DA, Meissner G. Single channel properties of heterotetrameric mutant RyR1 ion channels linked to core myopathies. J Biol Chem 2008; 283:6321-9. [PMID: 18171678 DOI: 10.1074/jbc.m707353200] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Skeletal muscle excitation-contraction coupling involves activation of homotetrameric ryanodine receptor ion channels (RyR1s), resulting in the rapid release of Ca(2+) from the sarcoplasmic reticulum. Previous work has shown that Ca(2+) release is impaired by mutations in RyR1 linked to Central Core Disease and Multiple Minicore Disease. We studied the consequences of these mutations on RyR1 function, following their expression in human embryonic kidney 293 cells and incorporation in lipid bilayers. RyR1-G4898E, -G4898R, and -DeltaV4926/I4927 mutants in the C-terminal pore region of RyR1 and N-terminal RyR1-R110W/L486V mutant all showed negligible Ca(2+) permeation and loss of Ca(2+)-dependent channel activity but maintained reduced K(+) conductances. Co-expression of wild type and mutant RyR1s resulted in Ca(2+)-dependent channel activities that exhibited intermediate Ca(2+) selectivities compared with K(+), which suggested the presence of tetrameric RyR1 complexes composed of wild type and mutant subunits. The number of wild-type subunits to maintain a functional heterotetrameric channel differed among the four RyR1 mutants. The results indicate that homozygous RyR1 mutations associated with core myopathies abolish or greatly reduce sarcoplasmic reticulum Ca(2+) release during excitation-contraction coupling. They further suggest that in individuals, expressing wild type and mutant alleles, a substantial portion of RyR1 channels is able to release Ca(2+) from sarcoplasmic reticulum.
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Affiliation(s)
- Le Xu
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599-7260, USA
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33
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Schug ZT, da Fonseca PCA, Bhanumathy CD, Wagner L, Zhang X, Bailey B, Morris EP, Yule DI, Joseph SK. Molecular characterization of the inositol 1,4,5-trisphosphate receptor pore-forming segment. J Biol Chem 2007; 283:2939-48. [PMID: 18025085 DOI: 10.1074/jbc.m706645200] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Specific residues in the putative pore helix, selectivity filter, and S6 transmembrane helix of the inositol 1,4,5-trisphosphate receptor were mutated in order to examine their effects on channel function. Mutation of 5 of 8 highly conserved residues in the pore helix/selectivity filter region inactivated the channel (C2533A, G2541A, G2545A, G2546A, and G2547A). Of the remaining three mutants, C2527A and R2543A were partially active and G2549A behaved like wild type receptor. Mutation of a putative glycine hinge residue in the S6 helix (G2586A) or a putative gating residue at the cytosolic end of S6 helix (F2592A) had minimal effects on function, although channel function was inactivated by G2586P and F2592D mutations. The mutagenesis data are interpreted in the context of a structural homology model of the inositol 1,4,5-trisphosphate receptor.
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Affiliation(s)
- Zachary T Schug
- Department of Pathology and Cell Biology, Thomas Jefferson University, 1020 Locust Drive, Philadelphia, PA 19107, USA
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An Ryr1I4895T mutation abolishes Ca2+ release channel function and delays development in homozygous offspring of a mutant mouse line. Proc Natl Acad Sci U S A 2007; 104:18537-42. [PMID: 18003898 DOI: 10.1073/pnas.0709312104] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A heterozygous Ile4898 to Thr (I4898T) mutation in the human type 1 ryanodine receptor/Ca(2+) release channel (RyR1) leads to a severe form of central core disease. We created a mouse line in which the corresponding Ryr1(I4895T) mutation was introduced by using a "knockin" protocol. The heterozygote does not exhibit an overt disease phenotype, but homozygous (IT/IT) mice are paralyzed and die perinatally, apparently because of asphyxia. Histological analysis shows that IT/IT mice have greatly reduced and amorphous skeletal muscle. Myotubes are small, nuclei remain central, myofibrils are disarranged, and no cross striation is obvious. Many areas indicate probable degeneration, with shortened myotubes containing central stacks of pyknotic nuclei. Other manifestations of a delay in completion of late stages of embryogenesis include growth retardation and marked delay in ossification, dermatogenesis, and cardiovascular development. Electron microscopy of IT/IT muscle demonstrates appropriate targeting and positioning of RyR1 at triad junctions and a normal organization of dihydropyridine receptor (DHPR) complexes into RyR1-associated tetrads. Functional studies carried out in cultured IT/IT myotubes show that ligand-induced and DHPR-activated RyR1 Ca(2+) release is absent, although retrograde enhancement of DHPR Ca(2+) conductance is retained. IT/IT mice, in which RyR1-mediated Ca(2+) release is abolished without altering the formation of the junctional DHPR-RyR1 macromolecular complex, provide a valuable model for elucidation of the role of RyR1-mediated Ca(2+) signaling in mammalian embryogenesis.
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Goonasekera SA, Beard NA, Groom L, Kimura T, Lyfenko AD, Rosenfeld A, Marty I, Dulhunty AF, Dirksen RT. Triadin binding to the C-terminal luminal loop of the ryanodine receptor is important for skeletal muscle excitation contraction coupling. ACTA ACUST UNITED AC 2007; 130:365-78. [PMID: 17846166 PMCID: PMC2151650 DOI: 10.1085/jgp.200709790] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Ca2+ release from intracellular stores is controlled by complex interactions between multiple proteins. Triadin is a transmembrane glycoprotein of the junctional sarcoplasmic reticulum of striated muscle that interacts with both calsequestrin and the type 1 ryanodine receptor (RyR1) to communicate changes in luminal Ca2+ to the release machinery. However, the potential impact of the triadin association with RyR1 in skeletal muscle excitation–contraction coupling remains elusive. Here we show that triadin binding to RyR1 is critically important for rapid Ca2+ release during excitation–contraction coupling. To assess the functional impact of the triadin-RyR1 interaction, we expressed RyR1 mutants in which one or more of three negatively charged residues (D4878, D4907, and E4908) in the terminal RyR1 intraluminal loop were mutated to alanines in RyR1-null (dyspedic) myotubes. Coimmunoprecipitation revealed that triadin, but not junctin, binding to RyR1 was abolished in the triple (D4878A/D4907A/E4908A) mutant and one of the double (D4907A/E4908A) mutants, partially reduced in the D4878A/D4907A double mutant, but not affected by either individual (D4878A, D4907A, E4908A) mutations or the D4878A/E4908A double mutation. Functional studies revealed that the rate of voltage- and ligand-gated SR Ca2+ release were reduced in proportion to the degree of interruption in triadin binding. Ryanodine binding, single channel recording, and calcium release experiments conducted on WT and triple mutant channels in the absence of triadin demonstrated that the luminal loop mutations do not directly alter RyR1 function. These findings demonstrate that junctin and triadin bind to different sites on RyR1 and that triadin plays an important role in ensuring rapid Ca2+ release during excitation–contraction coupling in skeletal muscle.
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Affiliation(s)
- Sanjeewa A Goonasekera
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
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Abstract
Central core disease (CCD) is an inherited neuromuscular disorder characterised by central cores on muscle biopsy and clinical features of a congenital myopathy. Prevalence is unknown but the condition is probably more common than other congenital myopathies. CCD typically presents in infancy with hypotonia and motor developmental delay and is characterized by predominantly proximal weakness pronounced in the hip girdle; orthopaedic complications are common and malignant hyperthermia susceptibility (MHS) is a frequent complication. CCD and MHS are allelic conditions both due to (predominantly dominant) mutations in the skeletal muscle ryanodine receptor (RYR1) gene, encoding the principal skeletal muscle sarcoplasmic reticulum calcium release channel (RyR1). Altered excitability and/or changes in calcium homeostasis within muscle cells due to mutation-induced conformational changes of the RyR protein are considered the main pathogenetic mechanism(s). The diagnosis of CCD is based on the presence of suggestive clinical features and central cores on muscle biopsy; muscle MRI may show a characteristic pattern of selective muscle involvement and aid the diagnosis in cases with equivocal histopathological findings. Mutational analysis of the RYR1 gene may provide genetic confirmation of the diagnosis. Management is mainly supportive and has to anticipate susceptibility to potentially life-threatening reactions to general anaesthesia. Further evaluation of the underlying molecular mechanisms may provide the basis for future rational pharmacological treatment. In the majority of patients, weakness is static or only slowly progressive, with a favourable long-term outcome.
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Affiliation(s)
- Heinz Jungbluth
- Evelina Children's Hospital, Department of Paediatric Neurology, St. Thomas' Hospital, London, UK.
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Hamada T, Bannister ML, Ikemoto N. Peptide probe study of the role of interaction between the cytoplasmic and transmembrane domains of the ryanodine receptor in the channel regulation mechanism. Biochemistry 2007; 46:4272-9. [PMID: 17361990 DOI: 10.1021/bi061557f] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ryanodine receptor (RyR) mutations linked with some congenital skeletal and cardiac diseases are localized to three easily definable regions: region 1 (N-terminal domain), region 2 (central domain), and a rather broad region 3 containing the channel pore. As shown in our recent studies, the interdomain interaction between regions 1 and 2 plays a critical role in channel regulation and pathogenesis. Here we present evidence that within region 3 there is a similar channel regulation mechanism mediated by an interdomain interaction. DP15, a peptide corresponding to RyR1 residues 4820-4841, produced significant activation of [3H]ryanodine binding above threshold Ca2+ concentrations (>or=0.3 microM), but MH mutations (L4823P or L4837V) made in DP15 almost completely abolished its channel activating function. To identify the DP15 binding site(s) within RyR1, DP15 (labeled with a fluorescent probe Alexa Fluor 680 and a photoaffinity cross-linker APG) was cross-linked to RyR1, and the site of cross-linking was identified by gel analysis of fluorescently labeled proteolytic fragments with the aid of Western blotting with site-specific antibodies. The shortest fluorescently labeled band was a 96 kDa fragment which was stained with an antibody directed to the region of residues 4114-4142 of RyR1, indicating that the interaction between the region of residues 4820-4841 adjacent to the channel pore and the 96 kDa segment containing the region of residues 4114-4142 is involved in the mechanism of Ca2+-dependent channel regulation. In further support of this concept, anti-DP15 antibody and cardiac counterpart of DP15 produced channel activation similar to that of DP15.
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Affiliation(s)
- Tomoyo Hamada
- Boston Biomedical Research Institute, Watertown, Massachusetts 02472, USA
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Lyfenko AD, Ducreux S, Wang Y, Xu L, Zorzato F, Ferreiro A, Meissner G, Treves S, Dirksen RT. Two central core disease (CCD) deletions in the C-terminal region of RYR1 alter muscle excitation-contraction (EC) coupling by distinct mechanisms. Hum Mutat 2007; 28:61-8. [PMID: 16958053 DOI: 10.1002/humu.20409] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Central core disease (CCD) and malignant hyperthermia (MH) are skeletal muscle disorders that are linked to mutations in the gene that encodes the type 1 ryanodine receptor (RYR1). The RYR1 ion channel plays a central role in excitation-contraction (EC) coupling by releasing Ca(2+) from an internal store. Pathogenic CCD mutations in RYR1 result in changes in the magnitude of Ca(2+) release during EC coupling. CCD has recently been linked to two novel deletions (c.12640_12648delCGCCAGTTC [p.Arg4214_Phe4216del] and c.14779_14784delGTCATC [p.Val4927_Ile4928del]) in the C-terminal region of RYR1. To determine the phenotypic consequences of these mutations and extend our understanding of the pathogenic mechanisms that underlie CCD, we determined functional effects on Ca(2+) release channel activity of analogous deletions (p.Arg4215_Phe4217del and p.Val4926_Ile4927del) engineered into rabbit RYR1 following expression in RYR1-null (dyspedic) myotubes and HEK293 cells. In addition, we assessed effects of the p.Arg4214 Phe4216del mutation on RYR1 function in lymphoblastoid cells obtained from CCD patients heterozygous for the mutation. Here we report that both deletions significantly reduce Ca(2+) release following RYR1 activation, but by different mechanisms. While the p.Arg4214_Phe4216del deletion promotes Ca(2+) depletion from intracellular stores by exhibiting a classic "leaky channel" behavior, the p.Val4927_Ile4928del deletion reduces Ca(2+) release by disrupting Ca(2+) gating and eliminating Ca(2+) permeation through the open channel.
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Affiliation(s)
- Alla D Lyfenko
- Department of Physiology and Pharmacology, University of Rochester, Rochester, New York 14642, USA
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Dulhunty AF, Beard NA, Pouliquin P, Casarotto MG. Agonists and antagonists of the cardiac ryanodine receptor: Potential therapeutic agents? Pharmacol Ther 2007; 113:247-63. [PMID: 17055586 DOI: 10.1016/j.pharmthera.2006.08.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2006] [Accepted: 08/16/2006] [Indexed: 10/24/2022]
Abstract
This review addresses the potential use of the intracellular ryanodine receptor (RyR) Ca(2+) release channel as a therapeutic target in heart disease. Heart disease encompasses a wide range of conditions with the major contributors to mortality and morbidity being ischaemic heart disease and heart failure (HF). In addition there are many rare, but devastating conditions, some of which are either genetically linked to the RyR and its regulatory proteins or involve drug-induced modification of the proteins. The defects in Ca(2+) signalling vary with the nature of the heart disease and the stage in its progress and therefore specific corrections require different modifications of Ca(2+) signalling. Compounds that activate the RyR are potential inotropic agents to increase the Ca(2+) transient and strength of contraction. Compounds that reduce RyR activity are potentially useful in conditions where excess RyR activity initiates arrhythmias, or depletes the Ca(2+) store, as in end stage HF. It has recently been discovered that the cardio-protective action of the drug JTV519 can be attributed partly to its ability to stabilise the interaction between the RyR and the 12.6 kDa binding protein for the commonly used immunosuppressive drug FK506 (FKBP12.6, known as tacrolimus). This has established the credibility of the RyR as a therapeutic target. We explore the possibility that mutations causing the rare RyR-linked arrhythmias will open the door to identification of novel RyR-based therapeutic agents. The use of regulatory binding sites within the RyR complex or on its associated proteins as templates for drug design is discussed.
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Affiliation(s)
- Angela F Dulhunty
- Division of Molecular Bioscience, John Curtin School of Medical Research, Australian National University, P.O. Box 334, ACT, 2601, Australia
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Durham WJ, Wehrens XHT, Sood S, Hamilton SL. Diseases associated with altered ryanodine receptor activity. Subcell Biochem 2007; 45:273-321. [PMID: 18193641 DOI: 10.1007/978-1-4020-6191-2_10] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Mutations in two intracellular Ca2+ release channels or ryanodine receptors (RyR1 and RyR2) are associated with a number of human skeletal and cardiac diseases. This chapter discusses these diseases in terms of known mechanisms, controversies, and unanswered questions. We also compare the cardiac and skeletal muscle diseases to explore common mechanisms.
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Affiliation(s)
- W J Durham
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
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Robinson R, Carpenter D, Shaw MA, Halsall J, Hopkins P. Mutations inRYR1in malignant hyperthermia and central core disease. Hum Mutat 2006; 27:977-89. [PMID: 16917943 DOI: 10.1002/humu.20356] [Citation(s) in RCA: 337] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The RYR1 gene encodes the skeletal muscle isoform ryanodine receptor and is fundamental to the process of excitation-contraction coupling and skeletal muscle calcium homeostasis. Mapping to chromosome 19q13.2, the gene comprises 106 exons and encodes a protein of 5,038 amino acids. Mutations in the gene have been found in association with several diseases: the pharmacogenetic disorder, malignant hyperthermia (MH); and three congenital myopathies, including central core disease (CCD), multiminicore disease (MmD), and in an isolated case of a congenital myopathy characterized on histology by cores and rods. The majority of gene mutations reported are missense changes identified in cases of MH and CCD. In vitro analysis has confirmed that alteration of normal calcium homeostasis is a functional consequence of some of these changes. Genotype-phenotype correlation studies performed using data from MH and CCD patients have also suggested that mutations may be associated with a range of disease severity phenotypes. This review aims to summarize the current understanding of RYR1 mutations reported in association with MH and CCD and the present viewpoint on the use of mutation data to aid clinical diagnosis of these conditions.
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Affiliation(s)
- Rachel Robinson
- Malignant Hyperthermia Investigation Unit, St James' University Hospital, Leeds, United Kingdom.
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Dulhunty AF, Beard NA, Pouliquin P, Kimura T. Novel regulators of RyR Ca2+ release channels: insight into molecular changes in genetically-linked myopathies. J Muscle Res Cell Motil 2006; 27:351-65. [PMID: 16909197 DOI: 10.1007/s10974-006-9086-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2006] [Accepted: 06/26/2006] [Indexed: 10/24/2022]
Abstract
There are many mutations in the ryanodine receptor (RyR) Ca2+ release channel that are implicated in skeletal muscle disorders and cardiac arrhythmias. More than 80 mutations in the skeletal RyR1 have been identified and linked to malignant hyperthermia, central core disease or multi-minicore disease, while more than 40 mutations in the cardiac RyR2 lead to ventricular arrhythmias and sudden cardiac death in patients with structurally normal hearts. These RyR mutations cause diverse changes in RyR activity which either excessively activate or block the channel in a manner that disrupts Ca2+ signalling in the muscle fibres. In a different myopathy, myotonic dystrophy (DM), a juvenile isoform of the skeletal RyR is preferentially expressed in adults. There are two regions of RyR1 that are variably spiced and developmentally regulated (ASI and ASII). The juvenile isoform (ASI(-)) is less active than the adult isoform (ASI(+)) and its over-expression in adults with DM may contribute to functional changes. Finally, mutations in an important regulator of the RyR, the Ca2+ binding protein calsequestrin (CSQ), have been linked to a disruption of Ca2+ homeostasis in cardiac myocytes that results in arrhythmias. We discuss evidence supporting the hypothesis that mutations in each of these situations alter protein/protein interactions within the RyR complex or between the RyR and its associated proteins. The disruption of these protein-protein interactions can lead either to excess Ca2+ release or reduced Ca2+ release and thus to abnormal Ca2+ homeostasis. Much of the evidence for disruption of protein-protein interactions has been provided by the actions of a group of novel RyR regulators, domain peptides with sequences that correspond to sequences within the RyR and which compete with the endogenous residues for their interaction sites.
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Affiliation(s)
- A F Dulhunty
- Division of Molecular Bioscience, JCSMR and RSC, ANU, Canberra, ACT, 2601, Australia.
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43
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Abstract
The sarcoplasmic reticulum (SR) provides feedback control required to balance the processes of calcium storage, release, and reuptake in skeletal muscle. This balance is achieved through the concerted action of three major classes of SR calcium-regulatory proteins: (1) luminal calcium-binding proteins (calsequestrin, histidine-rich calcium-binding protein, junctate, and sarcalumenin) for calcium storage; (2) SR calcium release channels (type 1 ryanodine receptor or RyR1 and IP3 receptors) for calcium release; and (3) sarco(endo)plasmic reticulum Ca2+ -ATPase (SERCA) pumps for calcium reuptake. Proper calcium storage, release, and reuptake are essential for normal skeletal muscle function. We review SR structure and function during normal skeletal muscle activity, the proteins that orchestrate calcium storage, release, and reuptake, and how phenotypically distinct muscle diseases (e.g., malignant hyperthermia, central core disease, and Brody disease) can result from subtle alterations in the activity of several key components of the SR calcium-regulatory machinery.
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Affiliation(s)
- Ann E Rossi
- Department of Pharmacology and Physiology, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642, USA
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Chelu MG, Goonasekera SA, Durham WJ, Tang W, Lueck JD, Riehl J, Pessah IN, Zhang P, Bhattacharjee MB, Dirksen RT, Hamilton SL. Heat- and anesthesia-induced malignant hyperthermia in an RyR1 knock-in mouse. FASEB J 2005; 20:329-30. [PMID: 16284304 DOI: 10.1096/fj.05-4497fje] [Citation(s) in RCA: 155] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Malignant hyperthermia (MH) is a life-threatening disorder characterized by skeletal muscle rigidity and elevated body temperature in response to halogenated anesthetics such as isoflurane or halothane. Mutation of tyrosine 522 of RyR1 (the predominant skeletal muscle calcium release channel) to serine has been associated with human malignant hyperthermia. In the present study, mice created harboring this mutation were found to represent the first murine model of human malignant hyperthermia. Mice homozygous for the Y522S mutation exhibit skeletal defects and die during embryonic development or soon after birth. Heterozygous mice, which correspond to the human occurrence of this mutation, are MH susceptible, experiencing whole body contractions and elevated core temperatures in response to isoflurane exposure or heat stress. Skeletal muscles from heterozygous mice exhibit increased susceptibility to caffeine- and heat-induced contractures in vitro. In addition, the heterozygous expression of the mutation results in enhanced RyR1 sensitivity to activation by temperature, caffeine, and voltage but not uncompensated sarcoplasmic reticulum calcium leak or store depletion. We conclude that the heterozygous expression of the Y522S mutation confers susceptibility to both heat- and anesthetic-induced MH responses.
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Affiliation(s)
- Mihail G Chelu
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
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Du G, Khanna V, Guo X, MacLENNAN D. Central core disease mutations R4892W, I4897T and G4898E in the ryanodine receptor isoform 1 reduce the Ca2+ sensitivity and amplitude of Ca2+-dependent Ca2+ release. Biochem J 2005; 382:557-64. [PMID: 15175001 PMCID: PMC1133812 DOI: 10.1042/bj20040580] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2004] [Revised: 05/17/2004] [Accepted: 06/03/2004] [Indexed: 11/17/2022]
Abstract
Three CCD (central core disease) mutants, R4892W (Arg4892-->), I4897T and G4898E, in the pore region of the skeletal-muscle Ca2+-release channel RyR1 (ryanodine receptor 1) were characterized using a newly developed assay that monitored Ca2+ release in the presence of Ca2+ uptake in microsomes isolated from HEK-293 cells (human embryonic kidney 293 cells), co-expressing each of the three mutants together with SERCA1a (sarcoplasmic/endoplasmic-reticulum Ca2+-ATPase 1a). Both Ca2+ sensitivity and peak amplitude of Ca2+ release were either absent from or sharply decreased in homotetrameric mutants. Co-expression of wild-type RyR1 with mutant RyR1 (heterotetrameric mutants) restored Ca2+ sensitivity partially, in the ratio 1:2, or fully, in the ratio 1:1. Peak amplitude was restored only partially in the ratio 1:2 or 1:1. Reduced amplitude was not correlated with maximum Ca2+ loading or the amount of expressed RyR1 protein. High-affinity [3H]ryanodine binding and caffeine-induced Ca2+ release were also absent from the three homotetrameric mutants. These results indicate that decreased Ca2+ sensitivity is one of the serious defects in these three excitation-contraction uncoupling CCD mutations. In CCD skeletal muscles, where a mixture of wild-type and mutant RyR1 is expressed, these defects are expected to decrease Ca2+-induced Ca2+ release, as well as orthograde Ca2+ release, in response to transverse tubular membrane depolarization.
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Affiliation(s)
- Guo Guang Du
- Banting and Best Department of Medical Research, Charles H. Best Institute, University of Toronto, 112 College St., Toronto, ON, Canada M5G 1L6
| | - Vijay K. Khanna
- Banting and Best Department of Medical Research, Charles H. Best Institute, University of Toronto, 112 College St., Toronto, ON, Canada M5G 1L6
| | - Xinghua Guo
- Banting and Best Department of Medical Research, Charles H. Best Institute, University of Toronto, 112 College St., Toronto, ON, Canada M5G 1L6
| | - David H. MacLENNAN
- Banting and Best Department of Medical Research, Charles H. Best Institute, University of Toronto, 112 College St., Toronto, ON, Canada M5G 1L6
- To whom correspondence should be addressed (email )
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46
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Avila G. Intracellular Ca2+ dynamics in malignant hyperthermia and central core disease: established concepts, new cellular mechanisms involved. Cell Calcium 2005; 37:121-7. [PMID: 15589992 DOI: 10.1016/j.ceca.2004.08.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2004] [Revised: 08/02/2004] [Accepted: 08/02/2004] [Indexed: 11/22/2022]
Abstract
Malignant hyperthermia (MH) and central core disease (CCD) are inherited human disorders of skeletal muscle Ca2+ homeostasis. Both MH and CCD are linked to mutations and/or deletions in the gene encoding the skeletal muscle ryanodine receptor (RyR1), the intracellular Ca2+ release channel, which is essential to excitation-contraction (EC) coupling. Our knowledge on how mutations in RyR1 disrupt intracellular Ca2+ homeostasis and EC coupling, eventually leading to MH and CCD has been recently improved, thanks to multidisciplinary studies ranging from clinical, single channel recordings, patch-clamp experiments, and molecular biology. This review presents a brief historical perspective, on how pioneer studies resulted in associating MH and CCD to RyR1. The review is also focused on discussing novel results in regard to pathophysiological consequences of specific MH/CCD RyR1 mutant proteins, which are representative of the different cellular mechanisms that are linked to either phenotype.
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Affiliation(s)
- Guillermo Avila
- Department of Biochemistry, Cinvestav-IPN, AP 14-740, Mexico City DF 07000, Mexico.
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Chelu MG, Danila CI, Gilman CP, Hamilton SL. Regulation of ryanodine receptors by FK506 binding proteins. Trends Cardiovasc Med 2005; 14:227-34. [PMID: 15451514 DOI: 10.1016/j.tcm.2004.06.003] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ryanodine receptors (RyRs) are the major sarcoplasmic reticulum calcium-release channels required for excitation-contraction coupling in skeletal and cardiac muscle. Mutations in RyRs have been linked to several human diseases. Mutations in the cardiac isoform of RyR2 are associated with catecholaminergic polymorphic ventricular arrhythmias (CPVT), and arrhythmogenic right ventricular dysplasia type 2 (ARVD2), whereas mutations in the skeletal muscle isoform (RyR1) are linked to malignant hyperthermia (MH) and central core disease (CCD). RyRs are modulated by several other proteins, including the FK506 binding proteins (FKBPs), FKBP12 and FKBP12.6. These immunophilins appear to stabilize a closed state of the channel and are important for cooperative interactions among the subunits of RyRs. This review discusses the regulation of RyRs by FKBPs and the possibility that defective modulation of RyR2 by FKBP12.6 could play a role in heart failure, CPVT, and ARVD2. Also discussed are the consequences of FKBP12 depletion to skeletal muscle and the possibility of FKBP12 involvement in certain forms of MH or CCD.
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Affiliation(s)
- Mihail G Chelu
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas 77030, USA
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Kobayashi S, Bannister ML, Gangopadhyay JP, Hamada T, Parness J, Ikemoto N. Dantrolene stabilizes domain interactions within the ryanodine receptor. J Biol Chem 2004; 280:6580-7. [PMID: 15611117 DOI: 10.1074/jbc.m408375200] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Interdomain interactions between N-terminal and central domains serving as a "domain switch" are believed to be essential to the functional regulation of the skeletal muscle ryanodine receptor-1 Ca(2+) channel. Mutational destabilization of the domain switch in malignant hyperthermia (MH), a genetic sensitivity to volatile anesthetics, causes functional instability of the channel. Dantrolene, a drug used to treat MH, binds to a region within this proposed domain switch. To explore its mechanism of action, the effect of dantrolene on MH-like channel activation by the synthetic domain peptide DP4 or anti-DP4 antibody was examined. A fluorescence probe, methylcoumarin acetate, was covalently attached to the domain switch using DP4 as a delivery vehicle. The magnitude of domain unzipping was determined from the accessibility of methylcoumarin acetate to a macromolecular fluorescence quencher. The Stern-Volmer quenching constant (K(Q)) increased with the addition of DP4 or anti-DP4 antibody. This increase was reversed by dantrolene at both 37 and 22 degrees C and was unaffected by calmodulin. [(3)H]Ryanodine binding to the sarcoplasmic reticulum and activation of sarcoplasmic reticulum Ca(2+) release, both measures of channel activation, were enhanced by DP4. These activities were inhibited by dantrolene at 37 degrees C, yet required the presence of calmodulin at 22 degrees C. These results suggest that the mechanism of action of dantrolene involves stabilization of domain-domain interactions within the domain switch, preventing domain unzipping-induced channel dysfunction. We suggest that temperature and calmodulin primarily affect the coupling between the domain switch and the downstream mechanism of regulation of Ca(2+) channel opening rather than the domain switch itself.
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Affiliation(s)
- Shigeki Kobayashi
- Boston Biomedical Research Institute, Watertown, Massachusetts 02472, USA
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49
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Brini M. Ryanodine receptor defects in muscle genetic diseases. Biochem Biophys Res Commun 2004; 322:1245-55. [PMID: 15336972 DOI: 10.1016/j.bbrc.2004.08.029] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2004] [Indexed: 11/22/2022]
Abstract
Ryanodine receptor (RyR), a homotetrameric Ca2+ release channel, is one of the main actors in the generation of Ca2+ signals that trigger muscle contraction. Three genes encode three isoforms of RyRs, which have tissue-restricted distribution. RyR1 and RyR2 are typical of muscle cells, with RyR1 originally considered the skeletal muscle type and RyR2 the cardiac type. However, RyR1 and RyR2 have recently been found in numerous other cell types, including, for instance, peripheral B and T lymphocytes. In contrast, RyR3 is widely distributed among cells. RyR1 and RyR2 are localized in a specialized portion of the sarcoplasmic reticulum (SR), the terminal cisternae, which is the portion of the SR Ca2+ store that releases Ca2+ to control the process of muscle contraction. A specific role for RyR3 has not yet been established: probably, its co-expression with the other RyR isoforms contributes to qualitatively modulate Ca2+-dependent processes in muscle cells and in neurons. Several mutations in the genes encoding RyR1 and RyR2 have been identified in autosomal dominant diseases of skeletal and cardiac muscle, such as malignant hyperthermia (MH), central core disease (CCD), catecholaminergic polymorphic ventricular tachycardia (CPVT), and arrhythmogenic right ventricular dysplasia type 2 (ARVD2). More recently, CCD cases with recessive inheritance have also been described. MH is a pharmacogenetic disease, but the others manifest as congenital myopathies. Even if their clinical phenotypes are well established, particularly in skeletal muscle, the molecular mechanisms that generate the conditions are not clear. A number of studies on cellular models have attempted to elucidate the molecular defects associated with the different mutations, but the problem of understanding how mutations in the same gene generate such an array of diverse pathological traits and diseases of widely different degrees of severity is still open. This review will consider the molecular and cellular effects of RyR mutations, summarizing recent data in the literature on Ca2+ dysregulation, which may lead to a better understanding of the functioning of RyRs.
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Affiliation(s)
- Marisa Brini
- Department of Biochemistry and Department of Experimental Veterinary Sciences, University of Padua, Viale G. Colombo 3, 35121 Padua, Italy
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50
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Lyfenko AD, Goonasekera SA, Dirksen RT. Dynamic alterations in myoplasmic Ca2+ in malignant hyperthermia and central core disease. Biochem Biophys Res Commun 2004; 322:1256-66. [PMID: 15336973 DOI: 10.1016/j.bbrc.2004.08.031] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2004] [Indexed: 11/26/2022]
Abstract
Ca2+ ions play a pivotal role in a wide array of cellular processes ranging from fertilization to cell death. In skeletal muscle, a mechanical interaction between plasma membrane dihydropyridine receptors (DHPRs, L-type Ca2+ channels) and Ca2+ release channels (ryanodine receptors, RyR1s) of the sarcoplasmic reticulum orchestrates a complex, bi-directional Ca2+ signaling process that converts electrical impulses in the sarcolemma into myoplasmic Ca2+ transients during excitation-contraction coupling. Mutations in the genes that encode the two proteins that coordinate this electrochemical conversion process (the DHPR and RyR1) result in a variety of skeletal muscle disorders including malignant hyperthermia (MH), central core disease (CCD), multiminicore disease, nemaline rod myopathy, and hypokalemic periodic paralysis. Although RyR1 and DHPR disease mutations are thought to alter excitability and Ca2+ homeostasis in skeletal muscle, only recently has research begun to probe the molecular mechanisms by which these genetic defects lead to distinct clinical and histopathological manifestations. This review focuses on recent advances in determining the impact of MH and CCD mutations in RyR1 on muscle Ca2+ signaling and how these effects contribute to disease-specific aspects of these disorders.
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Affiliation(s)
- Alla D Lyfenko
- Department of Pharmacology and Physiology, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY 14642, USA
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