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Avin KG, Dominguez JM, Chen NX, Hato T, Myslinski JJ, Gao H, Liu Y, McKinley TO, Brown KM, Moe SM, Natoli RM. Single-cell RNAseq provides insight into altered immune cell populations in human fracture nonunions. J Orthop Res 2023; 41:1060-1069. [PMID: 36200412 PMCID: PMC10335365 DOI: 10.1002/jor.25452] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 09/16/2022] [Accepted: 09/22/2022] [Indexed: 02/04/2023]
Abstract
Nonunion describes bone fractures that fail to heal, resulting in the fracture callus failing to fully ossify or, in atrophic cases, not forming altogether. Fracture healing is regulated, in part, by the balance of proinflammatory and anti-inflammatory processes occurring within the bone marrow and surface cell populations. We sought to further understand the role of osteoimmunology (i.e., study of the close relationship between the immune system and bone) by examining immune cell gene expression via single-cell RNA sequencing of intramedullary canal tissue obtained from human patients with femoral nonunions. Intramedullary canal tissue samples obtained by reaming were collected at the time of surgical repair for femur fracture nonunion (n = 5) or from native bone controls when harvesting autologous bone graft (n = 4). Cells within the samples were isolated and analyzed using the Chromium Single-Cell System (10x Genomics Inc.) and Illumina sequencers. Twenty-three distinct cell clusters were identified, with higher cell proportions in the nonunion samples for monocytes and CD14 + dendritic cells (DCs), and lower proportions of T cells, myelocytes, and promyelocytes in nonunion samples. Gene expression differences were identified in each of the cell clusters from cell types associated with osteoimmunology, including CD14 + DC, monocytes, T cells, promyelocytes, and myelocytes. These results provide human-derived gene profiles that can further our understanding of pathways that may be a cause or a consequence of nonunion, providing the clinical rationale to focus on specific components of osteoimmunology. Clinical significance: The novel single-cell approach may lead to clinically relevant diagnostic biomarkers during earlier stages of nonunion development and/or investigation into therapeutic options.
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Affiliation(s)
- Keith G. Avin
- Department of Physical Therapy, School of Health and Human Sciences, Indiana University, Indianapolis, Indiana, USA
- Division of Nephrology, School of Medicine, Indiana University, Indianapolis, Indiana, USA
| | - James M. Dominguez
- Division of Nephrology, School of Medicine, Indiana University, Indianapolis, Indiana, USA
| | - Neal X. Chen
- Division of Nephrology, School of Medicine, Indiana University, Indianapolis, Indiana, USA
| | - Takashi Hato
- Division of Nephrology, School of Medicine, Indiana University, Indianapolis, Indiana, USA
| | - Jered J. Myslinski
- Division of Nephrology, School of Medicine, Indiana University, Indianapolis, Indiana, USA
| | - Hongyu Gao
- Department of Medical and Molecular Genetics, School of Medicine, Indiana University, Indianapolis, Indiana, USA
| | - Yunlong Liu
- Department of Medical and Molecular Genetics, School of Medicine, Indiana University, Indianapolis, Indiana, USA
| | - Todd O. McKinley
- Department of Orthopaedic Surgery, School of Medicine, Indiana University, Indianapolis, Indiana, USA
| | - Krista M. Brown
- Department of Orthopaedic Surgery, School of Medicine, Indiana University, Indianapolis, Indiana, USA
| | - Sharon M. Moe
- Division of Nephrology, School of Medicine, Indiana University, Indianapolis, Indiana, USA
| | - Roman M. Natoli
- Department of Orthopaedic Surgery, School of Medicine, Indiana University, Indianapolis, Indiana, USA
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Wei Y, Qi T, Cao S, Zhang W, Yu F, Zeng H, Weng J. LncRNA XLOC_015548 affects the proliferation and differentiation of myoblasts via the MAPK signaling pathway. Exp Biol Med (Maywood) 2023; 248:469-480. [PMID: 36852460 PMCID: PMC10281533 DOI: 10.1177/15353702231151963] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 12/11/2022] [Indexed: 03/01/2023] Open
Abstract
In recent years, an increasing number of studies have reported that long non-coding RNAs (lncRNAs) play essential regulatory roles in myogenic differentiation. In this study, a specific LncRNA XLOC_015548 (Lnc000280) was identified. However, little research has explored its mechanism of action by constructing XLOC_015548 gene editing cell models. In this study, relevant sequences were obtained according to the RNA-seq results. Subsequently, XLOC_015548 knockdown and over-expression lentiviral vectors were constructed, and the C2C12 myoblast cell line was transfected to prepare the XLOC_015548 gene-edited myoblast model. The in vitro analysis revealed that over-expression of XLOC_015548 significantly promoted the proliferation and differentiation of myoblasts and the formation of myotubes, whereas the opposite result was obtained in the knockdown group. XLOC_015548 regulated myogenic differentiation and affected the expression of myogenic differentiation regulators such as Myod, myogenin, and MyHC. Regarding the signaling pathway, we found that XLOC_015548 correlated with the phosphorylation level of MAPK/MEK/ERK pathway proteins. And the degree of phosphorylation was positively correlated with the protein expression of myogenic differentiation regulators. In conclusion, a new gene-edited myoblast model was constructed based on the lncRNA regulator XLOC_015548. The in vitro cell experiments verified that XLOC_015548 had regulatory effects on muscle growth and myoblast differentiation. These findings provide a laboratory foundation for the clinical application of lncRNAs as regulatory factors in the treatment of disuse muscle atrophy.
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Affiliation(s)
- Yihao Wei
- Department of Bone & Joint Surgery, Peking University Shenzhen Hospital, Shenzhen 518036, China
- National & Local Joint Engineering Research Center of Orthopaedic Biomaterials, Peking University Shenzhen Hospital, Shenzhen 518036, China
- Shantou University Medical College, Shantou 515000, China
| | - Tiantian Qi
- Department of Bone & Joint Surgery, Peking University Shenzhen Hospital, Shenzhen 518036, China
- National & Local Joint Engineering Research Center of Orthopaedic Biomaterials, Peking University Shenzhen Hospital, Shenzhen 518036, China
| | - Siyang Cao
- Department of Bone & Joint Surgery, Peking University Shenzhen Hospital, Shenzhen 518036, China
- National & Local Joint Engineering Research Center of Orthopaedic Biomaterials, Peking University Shenzhen Hospital, Shenzhen 518036, China
| | - Weifei Zhang
- Department of Bone & Joint Surgery, Peking University Shenzhen Hospital, Shenzhen 518036, China
- National & Local Joint Engineering Research Center of Orthopaedic Biomaterials, Peking University Shenzhen Hospital, Shenzhen 518036, China
| | - Fei Yu
- Department of Bone & Joint Surgery, Peking University Shenzhen Hospital, Shenzhen 518036, China
- National & Local Joint Engineering Research Center of Orthopaedic Biomaterials, Peking University Shenzhen Hospital, Shenzhen 518036, China
| | - Hui Zeng
- Department of Bone & Joint Surgery, Peking University Shenzhen Hospital, Shenzhen 518036, China
- National & Local Joint Engineering Research Center of Orthopaedic Biomaterials, Peking University Shenzhen Hospital, Shenzhen 518036, China
| | - Jian Weng
- Department of Bone & Joint Surgery, Peking University Shenzhen Hospital, Shenzhen 518036, China
- National & Local Joint Engineering Research Center of Orthopaedic Biomaterials, Peking University Shenzhen Hospital, Shenzhen 518036, China
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Choi KM, Ko CY, An SM, Cho SH, Rowland DJ, Kim JH, Fasoli A, Chaudhari AJ, Bers DM, Yoon JC. Regulation of beige adipocyte thermogenesis by the cold-repressed ER protein NNAT. Mol Metab 2023; 69:101679. [PMID: 36708951 PMCID: PMC9932177 DOI: 10.1016/j.molmet.2023.101679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 01/17/2023] [Accepted: 01/18/2023] [Indexed: 01/26/2023] Open
Abstract
OBJECTIVE Cold stimuli trigger the conversion of white adipose tissue into beige adipose tissue, which is capable of non-shivering thermogenesis. However, what process drives this activation of thermogenesis in beige fat is not well understood. Here, we examine the ER protein NNAT as a regulator of thermogenesis in adipose tissue. METHODS We investigated the regulation of adipose tissue NNAT expression in response to changes in ambient temperature. We also evaluated the functional role of NNAT in thermogenic regulation using Nnat null mice and primary adipocytes that lack or overexpress NNAT. RESULTS Cold exposure or treatment with a β3-adrenergic agonist reduces the expression of adipose tissue NNAT in mice. Genetic disruption of Nnat in mice enhances inguinal adipose tissue thermogenesis. Nnat null mice exhibit improved cold tolerance both in the presence and absence of UCP1. Gain-of-function studies indicate that ectopic expression of Nnat abolishes adrenergic receptor-mediated respiration in beige adipocytes. NNAT physically interacts with the ER Ca2+-ATPase (SERCA) in adipocytes and inhibits its activity, impairing Ca2+ transport and heat dissipation. We further demonstrate that NHLRC1, an E3 ubiquitin protein ligase implicated in proteasomal degradation of NNAT, is induced by cold exposure or β3-adrenergic stimulation, thus providing regulatory control at the protein level. This serves to link cold stimuli to NNAT degradation in adipose tissue, which in turn leads to enhanced SERCA activity. CONCLUSIONS Our study implicates NNAT in the regulation of adipocyte thermogenesis.
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Affiliation(s)
- Kyung-Mi Choi
- Division of Endocrinology, Department of Internal Medicine, University of California Davis School of Medicine, Davis, CA 95616, USA; Institute of Molecular Biology and Genetics, School of Biological Sciences, Seoul National University, Seoul 08826, South Korea
| | - Christopher Y Ko
- Department of Pharmacology, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - Sung-Min An
- Division of Endocrinology, Department of Internal Medicine, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - Seung-Hee Cho
- Division of Endocrinology, Department of Internal Medicine, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - Douglas J Rowland
- Center for Molecular and Genomic Imaging, Department of Biomedical Engineering, University of California Davis, Davis, CA 95616, USA
| | - Jung Hak Kim
- Division of Endocrinology, Department of Internal Medicine, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - Anna Fasoli
- Department of Pharmacology, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - Abhijit J Chaudhari
- Department of Radiology, University of California Davis School of Medicine, Sacramento, CA 95825, USA
| | - Donald M Bers
- Department of Pharmacology, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - John C Yoon
- Division of Endocrinology, Department of Internal Medicine, University of California Davis School of Medicine, Davis, CA 95616, USA.
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Janssens L, De Puydt J, Milazzo M, Symoens S, De Bleecker JL, Herdewyn S. Risk of malignant hyperthermia in patients carrying a variant in the skeletal muscle ryanodine receptor 1 gene. Neuromuscul Disord 2022; 32:864-869. [PMID: 36283893 DOI: 10.1016/j.nmd.2022.10.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 10/12/2022] [Accepted: 10/13/2022] [Indexed: 12/15/2022]
Abstract
Malignant hyperthermia is a life-threatening disorder, which can be prevented by avoiding certain anesthetic agents. Pathogenic variants in the skeletal muscle ryanodine receptor 1-gene are linked to malignant hyperthermia. We retrospectively studied 15 patients who presented to our clinic with symptoms of muscle dysfunction (weakness, myalgia or cramps) and were later found to have a variant in the skeletal muscle ryanodine receptor 1-gene. Symptoms, creatine kinase levels, electromyography, muscle biopsy and in vitro contracture test results were reviewed. Six out of the eleven patients, with a variant of unknown significance in the skeletal muscle ryanodine receptor 1-gene, had a positive in vitro contracture test, indicating malignant hyperthermia susceptibility. In one patient, with two variants of unknown significance, both variants were required to express the malignant hyperthermia-susceptibility trait. Neurologists should consider screening the skeletal muscle ryanodine receptor 1-gene in patients with myalgia or cramps, even when few to no abnormalities on ancillary testing.
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Affiliation(s)
- Lise Janssens
- Faculty of medical and health sciences, Ghent University, Corneel Heymanslaan 10, Ghent 9000, Belgium
| | - Joris De Puydt
- University Hospital of Antwerp, Drie Eikenstraat 655, Edegem 2650, Belgium; Faculty of medical and health sciences, Antwerp University, Prinsstraat 13, Antwerp 2000, Belgium
| | - Mauro Milazzo
- Center for Medical Genetics Ghent, Ghent University Hospital, Corneel Heymanslaan 10, Ghent 9000, Belgium
| | - Sofie Symoens
- Faculty of medical and health sciences, Ghent University, Corneel Heymanslaan 10, Ghent 9000, Belgium; Center for Medical Genetics Ghent, Ghent University Hospital, Corneel Heymanslaan 10, Ghent 9000, Belgium
| | - Jan L De Bleecker
- Faculty of medical and health sciences, Ghent University, Corneel Heymanslaan 10, Ghent 9000, Belgium; Department of Neurology, Ghent University Hospital, Corneel Heymanslaan 10, Ghent 9000, Belgium
| | - Sarah Herdewyn
- Department of Neurology, Ghent University Hospital, Corneel Heymanslaan 10, Ghent 9000, Belgium.
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Geromella MS, Ryan CR, Braun JL, Finch MS, Maddalena LA, Bagshaw O, Hockey BL, Moradi F, Fenech RK, Ryoo J, Marko DM, Dhaliwal R, Sweezey-Munroe J, Hamstra SI, Gardner G, Silvera S, Vandenboom R, Roy BD, Stuart JA, MacPherson RE, Fajardo VA. Low-dose lithium supplementation promotes adipose tissue browning and sarco(endo)plasmic reticulum Ca2+ ATPase uncoupling in muscle. J Biol Chem 2022; 298:102568. [DOI: 10.1016/j.jbc.2022.102568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 09/20/2022] [Accepted: 09/23/2022] [Indexed: 11/11/2022] Open
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Sun Z, Wang L, Han L, Wang Y, Zhou Y, Li Q, Wu Y, Talabieke S, Hou Y, Wu L, Liu R, Fu Z, You H, Li BY, Zheng Y, Luo D. Functional Calsequestrin-1 Is Expressed in the Heart and Its Deficiency Is Causally Related to Malignant Hyperthermia-Like Arrhythmia. Circulation 2021; 144:788-804. [PMID: 34162222 DOI: 10.1161/circulationaha.121.053255] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background: Calsequestrins (Casqs), comprising the Casq1 and Casq2 isoforms, buffer Ca2+ and regulate its release in the sarcoplasmic reticulum (SR) of skeletal and cardiac muscle, respectively. Human inherited diseases associated with mutations in CASQ1 or CASQ2 include malignant hyperthermia/environmental heat stroke (MH/EHS) and catecholaminergic polymorphic ventricular tachycardia. However, patients with an MH/EHS event often suffer from arrhythmia for which the underlying mechanism remains unknown. Methods: Working hearts from conventional (Casq1-KO) and cardiac-specific (Casq1-CKO) Casq1 knockout mice were monitored in vivo and ex vivo by electrocardiogram and electrical mapping, respectively. MH was induced by 2% isoflurane and treated intraperitoneally with dantrolene. Time-lapse imaging was used to monitor intracellular Ca2+ activity in isolated mouse cardiomyocytes or neonatal rat ventricular myocytes (NRVMs) with knockdown, over-expression or truncation of the Casq1 gene. Conformational change in both Casqs was determined by crosslinking Western blot analysis. Results: Like MH/EHS patients, Casq1-KO and Casq1-CKO mice had faster basal heart rate, and ventricular tachycardia upon exposure to 2% isoflurane, which could be relieved by dantrolene. Basal sinus tachycardia and ventricular ectopic electrical triggering also occurred in Casq1-KO hearts ex vivo. Accordingly, the ventricular cardiomyocytes from Casq1-CKO mice displayed dantrolene-sensitive increased Ca2+ waves and diastole premature Ca2+ transients/oscillations upon isoflurane. NRVMs with Casq1-knockdown had enhanced spontaneous Ca2+ sparks/transients upon isoflurane, while cells over-expressing Casq1 exhibited decreased Ca2+ sparks/transients that were absent in cells with truncation of 9 amino acids at the C-terminus of Casq1. Structural evaluation showed that most of the Casq1 protein was present as a polymer and physically interacted with RyR2 in the ventricular SR. The Casq1 isoform was also expressed in human myocardium. Mechanistically, exposure to 2% isoflurane or heating at 41ºC induced Casq1 oligomerization in mouse ventricular and skeletal muscle tissues, leading to a reduced Casq1/RyR2 interaction and increased RyR2 activity in the ventricle. Conclusions: Casq1 is expressed in the heart, where it regulates SR Ca2+ release and heart rate. Casq1 deficiency independently causes MH/EHS-like ventricular arrhythmia by trigger-induced Casq1 oligomerization and a relief of its inhibitory effect on RyR2-mediated Ca2+ release, thus revealing a new inherited arrhythmia and a novel mechanism for MH/EHS arrhythmogenesis.
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Affiliation(s)
- Zhipeng Sun
- Department of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing 100069, P. R. China
| | - Luqi Wang
- Department of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing 100069, P. R. China
| | - Lu Han
- Beijing Lab for Cardiovascular Precision Medicine, Beijing Anzhen Hospital, Capital Medical University, Beijing 100011, P. R. China
| | - Yue Wang
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing 100011, P. R. China
| | - Yuan Zhou
- Department of Cardiac Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing 100011, P. R. China
| | - Qiang Li
- Department of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing 100069, P. R. China
| | - Yongquan Wu
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing 100011, P. R. China
| | - Shaletanati Talabieke
- Department of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing 100069, P. R. China
| | - Yunlong Hou
- College of Integrated Traditional Chinese and Western Medicine, Hebei University of Chinese Medicine; National Key Laboratory of Collateral Disease Research and Innovative Chinese Medicine, Shijiazhuang 050200, P. R. China
| | - Lulin Wu
- Department of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing 100069, P. R. China
| | - Ronghua Liu
- Department of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing 100069, P. R. China
| | - Zhiping Fu
- Department of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing 100069, P. R. China
| | - Hongjie You
- Department of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing 100069, P. R. China
| | - Bai-Yan Li
- Department of Pharmacology, School of Pharmacy, Harbin Medical University, Harbin, 150081, P. R. China
| | - Yuanyuan Zheng
- Department of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing 100069, P. R. China
| | - Dali Luo
- Department of Pharmacology, School of Basic Medical Sciences, Beijing Key Laboratory of Metabolic Disturbance Related Cardiovascular Disease, Capital Medical University, Beijing 100069, P. R. China
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7
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Johnston JJ, Dirksen RT, Girard T, Gonsalves SG, Hopkins PM, Riazi S, Saddic LA, Sambuughin N, Saxena R, Stowell K, Weber J, Rosenberg H, Biesecker LG. Variant curation expert panel recommendations for RYR1 pathogenicity classifications in malignant hyperthermia susceptibility. Genet Med 2021; 23:1288-1295. [PMID: 33767344 PMCID: PMC8263483 DOI: 10.1038/s41436-021-01125-w] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 02/07/2021] [Accepted: 02/09/2021] [Indexed: 12/15/2022] Open
Abstract
Purpose As a ClinGen Expert Panel (EP) we set out to adapt the ACMG pathogenicity criteria for classification of RYR1 variants as related to autosomal dominantly-inherited malignant hyperthermia (MH). Methods We specified ACMG/AMP criteria for variant classification for RYR1 and MH. Proposed rules were piloted on 84 variants. We applied quantitative evidence calibration for several criteria using likelihood ratios based on the Bayesian framework. Results Seven ACMG/AMP criteria were adopted without changes, nine were adopted with RYR1-specific modifications, and ten were dropped. The in silico (PP3 and BP4) and hot spot criteria (PM1) were evaluated quantitatively. REVEL gave an odds ratio (OR) of 23:1 for PP3 and 14:1 for BP4 using trichotomized cut-offs of ≥0.85 (pathogenic) and ≤0.5 (benign). The PM1 hotspot criterion had an OR of 24:1. PP3 and PM1 were implemented at moderate strength. Applying the revised ACMG criteria to 44 recognized MH variants, 29 were classified as pathogenic, 13 as likely pathogenic, and two as variants of uncertain significance. Conclusion Curation of these variants will facilitate classification of RYR1/MH genomic testing results, which is especially important for secondary findings analyses. Our approach to quantitatively calibrating criteria is generalizable to other variant curation expert panels.
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Affiliation(s)
- Jennifer J Johnston
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA.
| | - Robert T Dirksen
- Department of Pharmacology and Physiology, University of Rochester Medical School, Rochester, NY, USA
| | - Thierry Girard
- Department of Anesthesiology, University of Basel, Basel, Switzerland
| | - Stephen G Gonsalves
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Philip M Hopkins
- MH Unit, Leeds Institute of Medical Research at St James's, University of Leeds, Leeds, UK
| | - Sheila Riazi
- Department of Anesthesia and Pain Medicine, University Health Network, University of Toronto, Toronto, ON, Canada
| | - Louis A Saddic
- Department of Anesthesiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Nyamkhishig Sambuughin
- Consortium for Health and Military Performance, Uniformed Services University Health Science, Bethesda, MD, USA
| | - Richa Saxena
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Kathryn Stowell
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | | | | | - Leslie G Biesecker
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA.,NIH Intramural Sequencing Center, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
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8
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Agrawal A, Rathor R, Kumar R, Suryakumar G, Singh SN, Kumar B. Redox modification of ryanodine receptor contributes to impaired Ca 2+ homeostasis and exacerbates muscle atrophy under high altitude. Free Radic Biol Med 2020; 160:643-656. [PMID: 32916280 DOI: 10.1016/j.freeradbiomed.2020.09.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 08/17/2020] [Accepted: 09/01/2020] [Indexed: 12/18/2022]
Abstract
At extreme altitude, prolonged and severe hypoxia menaces human function and survival, and also associated with profound loss of muscle mass which results into a debilitating critical illness of skeletal muscle atrophy. Hypobaric hypoxia altered redox homeostasis and impaired calcium ion handling in skeletal muscles. Dysregulated Ca2+ homeostasis and activated calpain is the prime stressor in high altitude hypoxia while the reason for subsequent abnormal release of pathological Ca2+ into cytoplasm is largely unexplored. The present study identified the redox remodeling in the Ca2+ release channel, Ryanodine Receptor (RyR1) owing to its hypernitrosylation state in skeletal muscles in chronic hypobaric hypoxia exposed rats. RyR1-hypernitrosylation decreases the binding of FKBP12/calstabin-1 and other complexes from the channel, causing "leakiness" in RyR1 ion-channel. A strong RyR1 stabilizer, S107 enhanced binding affinity of FKBP12 with hypernitrosylated RyR1, reduced Sarco(endo)plasmic reticulum (SR) Ca2+ leak and improved muscle strength and function under chronic hypoxia. Administration of S107 inhibited the skeletal muscle damage, maintained ultrastructure of sarcomere and sarcolemmal integrity. Histological analysis proved the increase in cross-sectional area of myofibers. Further, the number of apoptotic cells was also reduced by S107 treatment. Conclusively, we proposed that the redox remodeling of RyR1 (hypernitrosylated-RyR1) might be responsible for dysregulated Ca2+ homeostasis which consequently impaired muscle strength and function in response to chronic hypoxic stress. Reduced SR Ca2+ leak and enhanced binding affinity of FKBP12 may provide a novel therapeutic avenue in ameliorating skeletal muscle atrophy at high altitude.
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Affiliation(s)
- Akanksha Agrawal
- Defence Institute of Physiology and Allied Sciences, Lucknow Road, Timarpur, New Delhi, 110054, India
| | - Richa Rathor
- Defence Institute of Physiology and Allied Sciences, Lucknow Road, Timarpur, New Delhi, 110054, India.
| | - Ravi Kumar
- Defence Institute of Physiology and Allied Sciences, Lucknow Road, Timarpur, New Delhi, 110054, India
| | - Geetha Suryakumar
- Defence Institute of Physiology and Allied Sciences, Lucknow Road, Timarpur, New Delhi, 110054, India
| | - Som Nath Singh
- Defence Institute of Physiology and Allied Sciences, Lucknow Road, Timarpur, New Delhi, 110054, India
| | - Bhuvnesh Kumar
- Defence Institute of Physiology and Allied Sciences, Lucknow Road, Timarpur, New Delhi, 110054, India
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9
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Pelletier L, Petiot A, Brocard J, Giannesini B, Giovannini D, Sanchez C, Travard L, Chivet M, Beaufils M, Kutchukian C, Bendahan D, Metzger D, Franzini Armstrong C, Romero NB, Rendu J, Jacquemond V, Fauré J, Marty I. In vivo RyR1 reduction in muscle triggers a core-like myopathy. Acta Neuropathol Commun 2020; 8:192. [PMID: 33176865 PMCID: PMC7657350 DOI: 10.1186/s40478-020-01068-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 10/27/2020] [Indexed: 12/16/2022] Open
Abstract
Mutations in the RYR1 gene, encoding the skeletal muscle calcium channel RyR1, lead to congenital myopathies, through expression of a channel with abnormal permeability and/or in reduced amount, but the direct functional whole organism consequences of exclusive reduction in RyR1 amount have never been studied. We have developed and characterized a mouse model with inducible muscle specific RYR1 deletion. Tamoxifen-induced recombination in the RYR1 gene at adult age resulted in a progressive reduction in the protein amount reaching a stable level of 50% of the initial amount, and was associated with a progressive muscle weakness and atrophy. Measurement of calcium fluxes in isolated muscle fibers demonstrated a reduction in the amplitude of RyR1-related calcium release mirroring the reduction in the protein amount. Alterations in the muscle structure were observed, with fibers atrophy, abnormal mitochondria distribution and membrane remodeling. An increase in the expression level of many proteins was observed, as well as an inhibition of the autophagy process. This model demonstrates that RyR1 reduction is sufficient to recapitulate most features of Central Core Disease, and accordingly similar alterations were observed in muscle biopsies from Dusty Core Disease patients (a subtype of Central Core Disease), pointing to common pathophysiological mechanisms related to RyR1 reduction.
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10
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Cote DR, Fuentes E, Elsayes AH, Ross JJ, Quraishi SA. A "crush" course on rhabdomyolysis: risk stratification and clinical management update for the perioperative clinician. J Anesth 2020; 34:585-598. [PMID: 32424487 DOI: 10.1007/s00540-020-02792-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 05/09/2020] [Indexed: 12/14/2022]
Abstract
Rhabdomyolysis, the release of myoglobin and other cellular breakdown products from necrotic muscle tissue, is seen in patients with crush injuries, drug overdose, malignant hyperthermia, muscular dystrophy, and with increasing frequency in obese patients undergoing routine procedures. For the perioperative clinician, managing the resultant shock, hyperkalemia, acidosis, and myoglobinuric acute kidney injury can present a significant challenge. Prompt recognition, hydration, and correction of metabolic disturbances may reduce or eliminate the need for long-term renal replacement therapy. This article reviews the pathophysiology and discusses key issues in the perioperative diagnosis, risk stratification, and management of rhabdomyolysis.
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Affiliation(s)
- Devan R Cote
- Department of Anesthesiology, Critical Care and Pain Medicine, Harvard Medical School, Massachusetts General Hospital, Boston, MA, USA
| | - Eva Fuentes
- Department of Surgery, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - Ali H Elsayes
- Department of Anesthesiology and Perioperative Medicine, Tufts Medical Center, Tufts University School of Medicine, 800 Washington Street, Boston, MA, 02111, USA
| | - Jonathan J Ross
- Department of Anesthesiology, Baystate Medical Center, Tufts University School of Medicine, Springfield, MA, USA
| | - Sadeq A Quraishi
- Department of Anesthesiology and Perioperative Medicine, Tufts Medical Center, Tufts University School of Medicine, 800 Washington Street, Boston, MA, 02111, USA.
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11
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Tammineni ER, Kraeva N, Figueroa L, Manno C, Ibarra CA, Klip A, Riazi S, Rios E. Intracellular calcium leak lowers glucose storage in human muscle, promoting hyperglycemia and diabetes. eLife 2020; 9:53999. [PMID: 32364497 PMCID: PMC7282812 DOI: 10.7554/elife.53999] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 05/04/2020] [Indexed: 12/18/2022] Open
Abstract
Most glucose is processed in muscle, for energy or glycogen stores. Malignant Hyperthermia Susceptibility (MHS) exemplifies muscle conditions that increase [Ca2+]cytosol. 42% of MHS patients have hyperglycemia. We show that phosphorylated glycogen phosphorylase (GPa), glycogen synthase (GSa) – respectively activated and inactivated by phosphorylation – and their Ca2+-dependent kinase (PhK), are elevated in microsomal extracts from MHS patients’ muscle. Glycogen and glucose transporter GLUT4 are decreased. [Ca2+]cytosol, increased to MHS levels, promoted GP phosphorylation. Imaging at ~100 nm resolution located GPa at sarcoplasmic reticulum (SR) junctional cisternae, and apo-GP at Z disk. MHS muscle therefore has a wide-ranging alteration in glucose metabolism: high [Ca2+]cytosol activates PhK, which inhibits GS, activates GP and moves it toward the SR, favoring glycogenolysis. The alterations probably cause these patients’ hyperglycemia. For basic studies, MHS emerges as a variable stressor, which forces glucose pathways from the normal to the diseased range, thereby exposing novel metabolic links. Animals and humans move by contracting the skeletal muscles attached to their bones. These muscles take up a type of sugar called glucose from food and use it to fuel contractions or store it for later in the form of glycogen. If muscles fail to use glucose it can lead to excessive sugar levels in the blood and a condition called diabetes. Within muscle cells are stores of calcium that signal the muscle to contract. Changes in calcium levels enhance the uptake of glucose that fuel these contractions. However, variations in calcium have also been linked to diabetes, and it remained unclear when and how these ‘signals’ become harmful. People with a condition called malignant hyperthermia susceptibility (MHS for short) have genetic mutations that allow calcium to leak out from these stores. This condition may result in excessive contractions causing the muscle to over-heat, become rigid and break down, which can lead to death if left untreated. A clinical study in 2019 found that out of hundreds of patients who had MHS, nearly half had high blood sugar and were likely to develop diabetes. Now, Tammineni et al. – including some of the researchers involved in the 2019 study – have set out to find why calcium leaks lead to elevated blood sugar levels. The experiments showed that enzymes that help convert glycogen to glucose are more active in patients with MHS, and found in different locations inside muscle cells. Whereas the enzymes that change glucose into glycogen are less active. This slows down the conversion of glucose into glycogen for storage and speeds up the breakdown of glycogen into glucose. Patients with MHS also had fewer molecules that transport glucose into muscle cells and stored less glycogen. These changes imply that less glucose is being removed from the blood. Next, Tammineni et al. used a microscopy technique that is able to distinguish finely separated objects with a precision not reached before in living muscle. This revealed that when the activity of the enzyme that breaks down glycogen increased, it moved next to the calcium store. This effect was also observed in the muscle cells of MHS patients that leaked calcium from their stores. Taken together, these observations may explain why patients with MHS have high levels of sugar in their blood. These findings suggest that MHS may start decades before developing diabetes and blood sugar levels in these patients should be regularly monitored. Future studies should investigate whether drugs that block calcium from leaking may help prevent high blood sugar in patients with MHS or other conditions that cause a similar calcium leak.
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Affiliation(s)
- Eshwar R Tammineni
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, United States
| | - Natalia Kraeva
- Malignant Hyperthermia Investigation Unit (MHIU) of the University Health Network (Canada), Toronto, Canada.,Department of Anaesthesia & Pain Management, Toronto General Hospital, UHN, University of Toronto, Toronto, Canada
| | - Lourdes Figueroa
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, United States
| | - Carlo Manno
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, United States
| | - Carlos A Ibarra
- Malignant Hyperthermia Investigation Unit (MHIU) of the University Health Network (Canada), Toronto, Canada.,Department of Anaesthesia & Pain Management, Toronto General Hospital, UHN, University of Toronto, Toronto, Canada
| | - Amira Klip
- Cell Biology Program, The Hospital for Sick Children, Toronto, Canada
| | - Sheila Riazi
- Malignant Hyperthermia Investigation Unit (MHIU) of the University Health Network (Canada), Toronto, Canada.,Department of Anaesthesia & Pain Management, Toronto General Hospital, UHN, University of Toronto, Toronto, Canada
| | - Eduardo Rios
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, United States
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12
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Qaisar R, Karim A, Elmoselhi AB. Muscle unloading: A comparison between spaceflight and ground-based models. Acta Physiol (Oxf) 2020; 228:e13431. [PMID: 31840423 DOI: 10.1111/apha.13431] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Revised: 12/09/2019] [Accepted: 12/12/2019] [Indexed: 12/12/2022]
Abstract
Prolonged unloading of skeletal muscle, a common outcome of events such as spaceflight, bed rest and hindlimb unloading, can result in extensive metabolic, structural and functional changes in muscle fibres. With advancement in investigations of cellular and molecular mechanisms, understanding of disuse muscle atrophy has significantly increased. However, substantial gaps exist in our understanding of the processes dictating muscle plasticity during unloading, which prevent us from developing effective interventions to combat muscle loss. This review aims to update the status of knowledge and underlying mechanisms leading to cellular and molecular changes in skeletal muscle during unloading. We have also discussed advances in the understanding of contractile dysfunction during spaceflights and in ground-based models of muscle unloading. Additionally, we have elaborated on potential therapeutic interventions that show promising results in boosting muscle mass and strength during mechanical unloading. Finally, we have identified key gaps in our knowledge as well as possible research direction for the future.
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Affiliation(s)
- Rizwan Qaisar
- Department of Basic Medical Sciences College of Medicine University of Sharjah Sharjah UAE
| | - Asima Karim
- Department of Basic Medical Sciences College of Medicine University of Sharjah Sharjah UAE
| | - Adel B. Elmoselhi
- Department of Basic Medical Sciences College of Medicine University of Sharjah Sharjah UAE
- Department of Physiology Michigan State University East Lansing MI USA
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13
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Fusto A, Moyle LA, Gilbert PM, Pegoraro E. Cored in the act: the use of models to understand core myopathies. Dis Model Mech 2019; 12:dmm041368. [PMID: 31874912 PMCID: PMC6955215 DOI: 10.1242/dmm.041368] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The core myopathies are a group of congenital myopathies with variable clinical expression - ranging from early-onset skeletal-muscle weakness to later-onset disease of variable severity - that are identified by characteristic 'core-like' lesions in myofibers and the presence of hypothonia and slowly or rather non-progressive muscle weakness. The genetic causes are diverse; central core disease is most often caused by mutations in ryanodine receptor 1 (RYR1), whereas multi-minicore disease is linked to pathogenic variants of several genes, including selenoprotein N (SELENON), RYR1 and titin (TTN). Understanding the mechanisms that drive core development and muscle weakness remains challenging due to the diversity of the excitation-contraction coupling (ECC) proteins involved and the differential effects of mutations across proteins. Because of this, the use of representative models expressing a mature ECC apparatus is crucial. Animal models have facilitated the identification of disease progression mechanisms for some mutations and have provided evidence to help explain genotype-phenotype correlations. However, many unanswered questions remain about the common and divergent pathological mechanisms that drive disease progression, and these mechanisms need to be understood in order to identify therapeutic targets. Several new transgenic animals have been described recently, expanding the spectrum of core myopathy models, including mice with patient-specific mutations. Furthermore, recent developments in 3D tissue engineering are expected to enable the study of core myopathy disease progression and the effects of potential therapeutic interventions in the context of human cells. In this Review, we summarize the current landscape of core myopathy models, and assess the hurdles and opportunities of future modeling strategies.
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Affiliation(s)
- Aurora Fusto
- Department of Neuroscience, University of Padua, Padua 35128, Italy
| | - Louise A Moyle
- Donnelly Centre, University of Toronto, Toronto, ON M5S3E1, Canada
- Institute of Biomaterials and Biochemical Engineering, University of Toronto, Toronto, ON M5S3G9, Canada
| | - Penney M Gilbert
- Donnelly Centre, University of Toronto, Toronto, ON M5S3E1, Canada
- Institute of Biomaterials and Biochemical Engineering, University of Toronto, Toronto, ON M5S3G9, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S3G5, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON M5S1A8, Canada
| | - Elena Pegoraro
- Department of Neuroscience, University of Padua, Padua 35128, Italy
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14
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Chagovetz AA, Klatt Shaw D, Ritchie E, Hoshijima K, Grunwald DJ. Interactions among ryanodine receptor isotypes contribute to muscle fiber type development and function. Dis Model Mech 2019; 13:dmm.038844. [PMID: 31383689 PMCID: PMC6906632 DOI: 10.1242/dmm.038844] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 07/17/2019] [Indexed: 12/14/2022] Open
Abstract
Mutations affecting ryanodine receptor (RyR) calcium release channels commonly underlie congenital myopathies. Although these channels are known principally for their essential roles in muscle contractility, mutations in the human RYR1 gene result in a broad spectrum of phenotypes, including muscle weakness, altered proportions of fiber types, anomalous muscle fibers with cores or centrally placed nuclei, and dysmorphic craniofacial features. Currently, it is unknown which phenotypes directly reflect requirements for RyRs and which result secondarily to aberrant muscle function. To identify biological processes requiring RyR function, skeletal muscle development was analyzed in zebrafish embryos harboring protein-null mutations. RyR channels contribute to both muscle fiber development and function. Loss of some RyRs had modest effects, altering muscle fiber-type specification in the embryo without compromising viability. In addition, each RyR-encoding gene contributed to normal swimming behavior and muscle function. The RyR channels do not function in a simple additive manner. For example, although isoform RyR1a is sufficient for muscle contraction in the absence of RyR1b, RyR1a normally attenuates the activity of the co-expressed RyR1b channel in slow muscle. RyR3 also acts to modify the functions of other RyR channels. Furthermore, diminished RyR-dependent contractility affects both muscle fiber maturation and craniofacial development. These findings help to explain some of the heterogeneity of phenotypes that accompany RyR1 mutations in humans.
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Affiliation(s)
- Alexis A Chagovetz
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
| | - Dana Klatt Shaw
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
| | - Erin Ritchie
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
| | - Kazuyuki Hoshijima
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
| | - David J Grunwald
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
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15
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Qin J, Sun Y, Liu S, Zhao R, Zhang Q, Pang W. MicroRNA-323-3p promotes myogenesis by targeting Smad2. J Cell Biochem 2019; 120:18751-18761. [PMID: 31218742 DOI: 10.1002/jcb.29187] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 05/28/2019] [Indexed: 11/12/2022]
Abstract
Skeletal muscle is an important and complex organ with multiple biological functions in humans and animals. Proliferation and differentiation of myoblasts are the key steps during the development of skeletal muscle. MicroRNA (miRNA) is a class of 21-nucleotide noncoding RNAs regulating gene expression by combining with the 3'-untranslated region of target messenger RNA. Many studies in recent years have suggested that miRNAs play a critical role in myogenesis. Through high-throughput sequencing, we found that miR-323-3p showed significant changes in the longissimus dorsi muscle of Rongchang pigs in different age groups. In this study, we discovered that overexpression of miR-323-3p repressed myoblast proliferation and promoted differentiation, whereas the inhibitor of miR-323-3p displayed the opposite results. Furthermore, we predicted Smad2 as the target gene of miR-323-3p and found that miR-323-3p directly modulated the expression level of Smad2. Then luciferase reporter assays verified that Smad2 was a target gene of miR-323-3p during the differentiation of myoblasts. These findings reveal that miR-323-3p is a positive regulator of myogenesis by targeting Smad2. This provides a novel mechanism of miRNAs in myogenesis.
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Affiliation(s)
- Jin Qin
- Laboratory of Animal Fat Deposition and Muscle Development, Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Yunmei Sun
- Laboratory of Animal Fat Deposition and Muscle Development, Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Shuge Liu
- Laboratory of Animal Fat Deposition and Muscle Development, Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Rui Zhao
- Laboratory of Animal Fat Deposition and Muscle Development, Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Qiyue Zhang
- Laboratory of Animal Fat Deposition and Muscle Development, Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Weijun Pang
- Laboratory of Animal Fat Deposition and Muscle Development, Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
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16
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Iodice P, Boncompagni S, Pietrangelo L, Galli L, Pierantozzi E, Rossi D, Fusella A, Caulo M, Kern H, Sorrentino V, Protasi F. Functional Electrical Stimulation: A Possible Strategy to Improve Muscle Function in Central Core Disease? Front Neurol 2019; 10:479. [PMID: 31191425 PMCID: PMC6548841 DOI: 10.3389/fneur.2019.00479] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 04/23/2019] [Indexed: 01/01/2023] Open
Abstract
Central Core Disease (CCD) is a congenital myopathy characterized by presence of amorphous central areas (or cores) lacking glycolytic/oxidative enzymes and mitochondria in skeletal muscle fibers. Most CCD families are linked to mutations in ryanodine receptor type-1 (RYR1), the gene encoding for the sarcoplasmic reticulum (SR) Ca2+ release channel of skeletal muscle. As no treatments are available for CCD, currently management of patients is essentially based on a physiotherapic approaches. Functional electrical stimulation (FES) is a technique used to deliver low energy electrical impulses to artificially stimulate selected skeletal muscle groups. Here we tested the efficacy of FES in counteracting muscle loss and improve function in the lower extremities of a 55-year-old female patient which was diagnosed with CCD at the age of 44. Genetic screening of the RyR1 gene identified a missense mutation (c.7354C>T) in exon 46 resulting in an amino acid substitution (p.R2452W) and a duplication (c.12853_12864dup12) in exon 91. The patient was treated with FES for 26 months and subjected before, during, and after training to a series of functional and structural assessments: measurement of maximum isometric force of leg extensor muscles, magnetic resonance imaging, a complete set of functional tests to assess mobility in activities of daily living, and analysis of muscle biopsies by histology and electron microscopy. All results point to an improvement in muscle structure and function induced by FES suggesting that this approach could be considered as an additional supportive measure to maintain/improve muscle function (and possibly reduce muscle loss) in CCD patients.
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Affiliation(s)
- Pierpaolo Iodice
- CeSI-Met-Center for Research on Ageing and Translational Medicine, University G. d'Annunzio, Chieti, Italy.,CETAPS-EA3832, University of Rouen Normandy, Mont-Saint-Aignan, France
| | - Simona Boncompagni
- CeSI-Met-Center for Research on Ageing and Translational Medicine, University G. d'Annunzio, Chieti, Italy
| | - Laura Pietrangelo
- CeSI-Met-Center for Research on Ageing and Translational Medicine, University G. d'Annunzio, Chieti, Italy
| | - Lucia Galli
- Department of Molecular and Developmental Medicine, University of Siena and Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Enrico Pierantozzi
- Department of Molecular and Developmental Medicine, University of Siena and Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Daniela Rossi
- Department of Molecular and Developmental Medicine, University of Siena and Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Aurora Fusella
- CeSI-Met-Center for Research on Ageing and Translational Medicine, University G. d'Annunzio, Chieti, Italy
| | - Massimo Caulo
- DNICS, Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio, Chieti, Italy
| | - Helmut Kern
- Ludwig Boltzmann Institute of Electrical Stimulation and Physical Rehabilitation, Vienna, Austria
| | - Vincenzo Sorrentino
- Department of Molecular and Developmental Medicine, University of Siena and Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Feliciano Protasi
- CeSI-Met-Center for Research on Ageing and Translational Medicine, University G. d'Annunzio, Chieti, Italy.,Department of Medicine and Aging Science, University G. d'Annunzio, Chieti, Italy
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17
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Gamu D, Juracic ES, Hall KJ, Tupling AR. The sarcoplasmic reticulum and SERCA: a nexus for muscular adaptive thermogenesis. Appl Physiol Nutr Metab 2019; 45:1-10. [PMID: 31116956 DOI: 10.1139/apnm-2019-0067] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
We are currently facing an "obesity epidemic" worldwide. Promoting inefficient metabolism in muscle represents a potential treatment for obesity and its complications. Sarco(endo)plasmic reticulum (SR) Ca2+-ATPase (SERCA) pumps in muscle are responsible for maintaining low cytosolic Ca2+ concentration through the ATP-dependent pumping of Ca2+ from the cytosol into the SR lumen. SERCA activity has the potential to be a critical regulator of body mass and adiposity given that it is estimated to contribute upwards of 20% of daily energy expenditure. More interestingly, this fraction can be modified physiologically in the face of stressors, such as ambient temperature and diet, through its physical interaction with several regulators known to inhibit Ca2+ uptake and muscle function. In this review, we discuss advances in our understanding of Ca2+-cycling thermogenesis within skeletal muscle, focusing on SERCA and its protein regulators, which were thought previously to only modulate muscular contractility. Novelty ATP consumption by SERCA pumps comprises a large proportion of resting energy expenditure in muscle and is dynamically regulated through interactions with small SERCA regulatory proteins. SERCA efficiency correlates significantly with resting metabolism, such that individuals with a higher resting metabolic rate have less energetically efficient SERCA Ca2+ pumping in muscle (i.e., lower coupling ratio). Futile Ca2+ cycling is a versatile heat generating mechanism utilized by both skeletal muscle and beige fat.
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Affiliation(s)
- Daniel Gamu
- Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1, Canada.,Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Emma Sara Juracic
- Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1, Canada.,Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Karlee J Hall
- Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1, Canada.,Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - A Russell Tupling
- Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1, Canada.,Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
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18
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Haji-Ghassemi O, Yuchi Z, Van Petegem F. The Cardiac Ryanodine Receptor Phosphorylation Hotspot Embraces PKA in a Phosphorylation-Dependent Manner. Mol Cell 2019; 75:39-52.e4. [PMID: 31078384 DOI: 10.1016/j.molcel.2019.04.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 03/05/2019] [Accepted: 04/11/2019] [Indexed: 12/22/2022]
Abstract
Ryanodine receptors (RyRs) are intracellular Ca2+ release channels controlling essential cellular functions. RyRs are targeted by cyclic AMP (cAMP)-dependent protein kinase A (PKA), a controversial regulation implicated in disorders ranging from heart failure to Alzheimer's. Using crystal structures, we show that the phosphorylation hotspot domain of RyR2 embraces the PKA catalytic subunit, with an extensive interface not seen in PKA complexes with peptides. We trapped an intermediary open-form PKA bound to the RyR2 domain and an ATP analog, showing that PKA can engage substrates in an open form. Phosphomimetics or prior phosphorylation at nearby sites in RyR2 either enhance or reduce the activity of PKA. Finally, we show that a phosphomimetic at S2813, a well-known target site for calmodulin-dependent kinase II, induces the formation of an alpha helix in the phosphorylation domain, resulting in increased interactions and PKA activity. This shows that the different phosphorylation sites in RyR2 are not independent.
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Affiliation(s)
- Omid Haji-Ghassemi
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Zhiguang Yuchi
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
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19
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Abstract
The congenital myopathies are a genetically heterogeneous and diverse group of early-onset, nondystrophic neuromuscular disorders. While the originally reported "classical" entities within this group - Central Core Disease, Multiminicore Disease, Nemaline Myopathy, and Centronuclear Myopathy - were defined by the predominant finding on muscle biopsy, "novel" forms with multiple, subtle, and unusual histopathologic features have been described more recently, reflective of an expanding phenotypical spectrum. The main disease mechanisms concern excitation-contraction coupling, intracellular calcium homeostasis, and thin/thick filament interactions. Management to date has been mainly supportive. Therapeutic strategies currently at various stages of exploration include genetic interventions aimed at direct correction of the underlying genetic defect, enzyme replacement therapy, and pharmacologic approaches, either specifically targeting the principal effect of the underlying gene mutation, or addressing its downstream consequences more generally. Clinical trial development is accelerating but will require more robust natural history data and tailored outcome measures.
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Affiliation(s)
- Heinz Jungbluth
- Department of Paediatric Neurology, Neuromuscular Service, Evelina's Children Hospital, Guy's and St. Thomas' Hospital NHS Foundation Trust, London, United Kingdom; Randall Division for Cell and Molecular Biophysics, Muscle Signalling Section, London, United Kingdom; Department of Basic and Clinical Neuroscience, IoPPN, King's College, London, United Kingdom.
| | - Francesco Muntoni
- The Dubowitz Neuromuscular Centre, Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health & Great Ormond Street Hospital for Children, London, United Kingdom; NIHR Great Ormond Street Hospital Biomedical Research Centre, London, United Kingdom
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20
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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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21
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Jones PM, Allen BN, Cherry RA, Dubois L, Vogt KN, Shariff SZ, Bray Jenkyn KM, Riazi S, Wijeysundera DN. Association between known or strongly suspected malignant hyperthermia susceptibility and postoperative outcomes: an observational population-based study. Can J Anaesth 2018; 66:161-181. [DOI: 10.1007/s12630-018-1250-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 08/13/2018] [Accepted: 08/16/2018] [Indexed: 12/20/2022] Open
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22
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Figueroa L, Kraeva N, Manno C, Toro S, Ríos E, Riazi S. Abnormal calcium signalling and the caffeine-halothane contracture test. Br J Anaesth 2018; 122:32-41. [PMID: 30579404 PMCID: PMC6334558 DOI: 10.1016/j.bja.2018.08.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 07/16/2018] [Accepted: 08/06/2018] [Indexed: 01/20/2023] Open
Abstract
Background The variable clinical presentation of malignant hyperthermia (MH), a disorder of calcium signalling, hinders its diagnosis and management. Diagnosis relies on the caffeine–halothane contracture test, measuring contraction forces upon exposure of muscle to caffeine or halothane (FC and FH, respectively). Patients with above-threshold FC or FH are diagnosed as MH susceptible. Many patients test positive to halothane only (termed ‘HH’). Our objective was to determine the characteristics of these HH patients, including their clinical symptoms and features of cytosolic Ca2+ signalling related to excitation–contraction coupling in myotubes. Methods After institutional ethics committee approval, recruited patients undergoing contracture testing at Toronto's MH centre were assigned to three groups: HH, doubly positive (HS), and negative patients (HN). A clinical index was assembled from musculoskeletal symptoms and signs. An analogous calcium index summarised four measures in cultured myotubes: resting [Ca2+]cytosol, frequency of spontaneous cytosolic Ca2+ events, Ca2+ waves, and cell-wide Ca2+ spikes after electrical stimulation. Results The highest values of both indexes were found in the HH group; the differences in calcium index between HH and the other groups were statistically significant. The principal component analysis confirmed the unique cell-level features of the HH group, and identified elevated resting [Ca2+]cytosol and spontaneous event frequency as the defining HH characteristics. Conclusions These findings suggest that HH pathogenesis stems from excess Ca2+ leak through sarcoplasmic reticulum channels. This identifies HH as a separate diagnostic group and opens their condition to treatment based on understanding of pathophysiological mechanisms.
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Affiliation(s)
- L Figueroa
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, IL, USA
| | - N Kraeva
- Malignant Hyperthermia Investigation Unit of the University Health Network, Toronto, ON, Canada; Department of Anaesthesia & Pain Management, Toronto General Hospital, University of Toronto, Toronto, ON, Canada
| | - C Manno
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, IL, USA
| | - S Toro
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, IL, USA
| | - E Ríos
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, IL, USA.
| | - S Riazi
- Malignant Hyperthermia Investigation Unit of the University Health Network, Toronto, ON, Canada; Department of Anaesthesia & Pain Management, Toronto General Hospital, University of Toronto, Toronto, ON, Canada
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23
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Du J, Zhang P, Zhao X, He J, Xu Y, Zou Q, Luo J, Shen L, Gu H, Tang Q, Li M, Jiang Y, Tang G, Bai L, Li X, Wang J, Zhang S, Zhu L. MicroRNA-351-5p mediates skeletal myogenesis by directly targeting lactamase-β and is regulated by lnc-mg. FASEB J 2018; 33:1911-1926. [PMID: 30216112 DOI: 10.1096/fj.201701394rrr] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Skeletal muscle is an important and complex organ with a variety of functions in humans and animals. Skeletal myogenesis is a multistep and complex process, and increasing evidence suggests that microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) play critical roles in skeletal myogenesis. In this study the expression of miR-351-5p is dynamically regulated during skeletal myogenesis in vitro and in vivo. Cell-counting kit-8, qRT-PCR, and EdU immunofluorescence analysis showed that miR-351-5p overexpression promoted the proliferation and inhibited the differentiation of C2C12 myoblast, whereas inhibition of miR-351-5p had the opposite effect. In addition, miR-351-5p mediated the regulation of muscle fiber type transition in vivo. In vitro, loss of miR-351-5p in muscle tissues promoted muscle hypertrophy and increased slow-twitch fibers in the gastrocnemius muscles of mice. Luciferase reporter assay and functional analyses demonstrated that lactamase β ( LACTB) is a direct target of miR-351-5p involved in the regulation of skeletal myogenesis. Expression levels of a myogenesis-associated lncRNA ( lnc-mg) correlated negatively with miR-351-5p and positively with LACTB during C2C12 myoblast proliferation and differentiation. Further analyses showed that lnc-mg acted as a molecular sponge for miR-351-5p, demonstrating its involvement in the negative regulation of LACTB by miR-351-5p during skeletal myogenesis. These findings indicate that miRNA-351-5p functions in skeletal myogenesis by targeting LACTB and is regulated by lnc-mg, supporting the role of the competing endogenous RNA network in skeletal myogenesis.-Du, J., Zhang, P., Zhao, X., He, J., Xu, Y., Zou, Q., Luo, J., Shen, L., Gu, H., Tang, Q., Li, M., Jiang, Y., Tang, G., Bai, L., Li, X., Wang, J., Zhang, S., Zhu, L. MicroRNA-351-5p mediates skeletal myogenesis by directly targeting lactamase β and is regulated by lnc-mg.
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Affiliation(s)
- Jingjing Du
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Peiwen Zhang
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Xue Zhao
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Jin He
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Yan Xu
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Qin Zou
- College of Life and Science, Sichuan Agricultural University, Chengdu, China; and
| | - Jia Luo
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Linyuan Shen
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Hao Gu
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Qianzi Tang
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Mingzhou Li
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Yanzhi Jiang
- College of Life and Science, Sichuan Agricultural University, Chengdu, China; and
| | - Guoqing Tang
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Lin Bai
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Xuewei Li
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Jinyong Wang
- Chongqing Academy of Animal Science, Rongchang, China
| | - Shunhua Zhang
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Li Zhu
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
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24
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Marcucci L, Canato M, Protasi F, Stienen GJM, Reggiani C. A 3D diffusional-compartmental model of the calcium dynamics in cytosol, sarcoplasmic reticulum and mitochondria of murine skeletal muscle fibers. PLoS One 2018; 13:e0201050. [PMID: 30048500 PMCID: PMC6062086 DOI: 10.1371/journal.pone.0201050] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 07/06/2018] [Indexed: 11/19/2022] Open
Abstract
Variations of free calcium concentration ([Ca2+]) are powerful intracellular signals, controlling contraction as well as metabolism in muscle cells. To fully understand the role of calcium redistribution upon excitation and contraction in skeletal muscle cells, the local [Ca2+] in different compartments needs to be taken into consideration. Fluorescent probes allow the determination of [Ca2+] in the cytosol where myofibrils are embedded, the lumen of the sarcoplasmic reticulum (SR) and the mitochondrial matrix. Previously, models have been developed describing intracellular calcium handling in skeletal and cardiac muscle cells. However, a comprehensive model describing the kinetics of the changes in free calcium concentration in these three compartments is lacking. We designed a new 3D compartmental model of the half sarcomere with radial symmetry, which accounts for diffusion of Ca2+ into the three compartments and simulates its dynamics at rest and at various rates of stimulation in mice skeletal muscle fibers. This model satisfactorily reproduces both the amplitude and time course of the variations of [Ca2+] in the three compartments in mouse fast fibers. As an illustration of the applicability of the model, we investigated the effects of Calsequestrin (CSQ) ablation. CSQ is the main Ca2+ buffer in the SR, localized in close proximity of its calcium release sites and near to the mitochondria. CSQ knock-out mice muscles still preserve a near-normal contractile behavior, but it is unclear whether this is caused by additional SR calcium buffering or a significant contribution of calcium entry from extracellular space, via stored-operated calcium entry (SOCE). The model enabled quantitative assessment of these two scenarios by comparison to measurements of local calcium in the cytosol, the SR and the mitochondria. In conclusion, the model represents a useful tool to investigate the impact of protein ablation and of pharmacological interventions on intracellular calcium dynamics in mice skeletal muscle.
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Affiliation(s)
- Lorenzo Marcucci
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Marta Canato
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Feliciano Protasi
- CeSI-Met - Center for Research on Ageing and Translational Medicine, Chieti, Italy
- Department of Medicine and Aging Science; University G. d’Annunzio, Chieti, Italy
| | - Ger J. M. Stienen
- Department of Physiology, VU University Medical Centre, Amsterdam Cardiovascular Sciences, Amsterdam, the Netherlands
| | - Carlo Reggiani
- Department of Biomedical Sciences, University of Padova, Padova, Italy
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25
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A comprehensive review of malignant hyperthermia: Preventing further fatalities in orthopedic surgery. J Orthop 2018; 15:578-580. [PMID: 29881197 DOI: 10.1016/j.jor.2018.05.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 05/06/2018] [Indexed: 12/13/2022] Open
Abstract
Most frequently associated with orthopedic surgery, malignant hyperthermia is a rare genetic condition linked to volatile anesthetics and succinylcholine. If not treated quickly with appropriate measures, death may result. To aid in the prevention of further fatalities, this review seeks to educate clinicians and staff on the presentation and treatment of this disease, as well as to provide a comprehensive overview by further addressing prevalence, similar conditions, pathogenesis and other aspects. Although the number of deaths due to malignant hyperthermia has greatly declined in the last several years, increased knowledge may eliminate associated mortalities, particularly in the orthopedic setting.
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26
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Abstract
During the complex series of events leading to muscle contraction, the initial electric signal coming from motor neurons is transformed into an increase in calcium concentration that triggers sliding of myofibrils. This process, referred to as excitation-contraction coupling, is reliant upon the calcium-release complex, which is restricted spatially to a sub-compartment of muscle cells ("the triad") and regulated precisely. Any dysfunction in the calcium-release complex leads to muscle impairment and myopathy. Various causes can lead to alterations in excitation-contraction coupling and to muscle diseases. The latter are reviewed and classified into four categories: (i) mutation in a protein of the calcium-release complex; (ii) alteration in triad structure; (iii) modification of regulation of channels; (iv) modification in calcium stores within the muscle. Current knowledge of the pathophysiologic mechanisms in each category is described and discussed.
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Affiliation(s)
- Isabelle Marty
- University Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, F-38000 Grenoble, France.,INSERM, U1216, F-38000 Grenoble, France
| | - Julien Fauré
- University Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, F-38000 Grenoble, France.,INSERM, U1216, F-38000 Grenoble, France.,CHU de Grenoble, F-38000 Grenoble, France
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27
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Congenital myopathies: disorders of excitation-contraction coupling and muscle contraction. Nat Rev Neurol 2018; 14:151-167. [PMID: 29391587 DOI: 10.1038/nrneurol.2017.191] [Citation(s) in RCA: 177] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The congenital myopathies are a group of early-onset, non-dystrophic neuromuscular conditions with characteristic muscle biopsy findings, variable severity and a stable or slowly progressive course. Pronounced weakness in axial and proximal muscle groups is a common feature, and involvement of extraocular, cardiorespiratory and/or distal muscles can implicate specific genetic defects. Central core disease (CCD), multi-minicore disease (MmD), centronuclear myopathy (CNM) and nemaline myopathy were among the first congenital myopathies to be reported, and they still represent the main diagnostic categories. However, these entities seem to belong to a much wider phenotypic spectrum. To date, congenital myopathies have been attributed to mutations in over 20 genes, which encode proteins implicated in skeletal muscle Ca2+ homeostasis, excitation-contraction coupling, thin-thick filament assembly and interactions, and other mechanisms. RYR1 mutations are the most frequent genetic cause, and CCD and MmD are the most common subgroups. Next-generation sequencing has vastly improved mutation detection and has enabled the identification of novel genetic backgrounds. At present, management of congenital myopathies is largely supportive, although new therapeutic approaches are reaching the clinical trial stage.
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28
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Reduced expression of cardiac ryanodine receptor protects against stress-induced ventricular tachyarrhythmia, but increases the susceptibility to cardiac alternans. Biochem J 2018; 475:169-183. [PMID: 29170159 DOI: 10.1042/bcj20170631] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 11/08/2017] [Accepted: 11/22/2017] [Indexed: 01/30/2023]
Abstract
Reduced protein expression of the cardiac ryanodine receptor type 2 (RyR2) is thought to affect the susceptibility to stress-induced ventricular tachyarrhythmia (VT) and cardiac alternans, but direct evidence for the role of RyR2 protein expression in VT and cardiac alternans is lacking. Here, we used a mouse model (crrm1) that expresses a reduced level of the RyR2 protein to determine the impact of reduced RyR2 protein expression on the susceptibility to VT, cardiac alternans, cardiac hypertrophy, and sudden death. Electrocardiographic analysis revealed that after the injection of relatively high doses of caffeine and epinephrine (agents commonly used for stress test), wild-type (WT) mice displayed long-lasting VTs, whereas the crrm1 mutant mice exhibited no VTs at all, indicating that the crrm1 mutant mice are resistant to stress-induced VTs. Intact heart Ca2+ imaging and action potential (AP) recordings showed that the crrm1 mutant mice are more susceptible to fast-pacing induced Ca2+ alternans and AP duration alternans compared with WT mice. The crrm1 mutant mice also showed an increased heart-to-body-weight ratio and incidence of sudden death at young ages. Furthermore, the crrm1 mutant hearts displayed altered Ca2+ transients with increased time-to-peak and decay time (T50), increased ventricular wall thickness and ventricular cell area compared with WT hearts. These results indicate that reduced RyR2 protein expression suppresses stress-induced VTs, but enhances the susceptibility to cardiac alternans, hypertrophy, and sudden death.
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29
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Abstract
This article reviews advancements in the genetics of malignant hyperthermia, new technologies and approaches for its diagnosis, and the existing limitations of genetic testing for malignant hyperthermia. It also reviews the various RYR1-related disorders and phenotypes, such as myopathies, exertional rhabdomyolysis, and bleeding disorders, and examines the connection between these disorders and malignant hyperthermia.
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30
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Dulhunty AF, Wei-LaPierre L, Casarotto MG, Beard NA. Core skeletal muscle ryanodine receptor calcium release complex. Clin Exp Pharmacol Physiol 2017; 44:3-12. [PMID: 27696487 DOI: 10.1111/1440-1681.12676] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Revised: 09/27/2016] [Accepted: 09/27/2016] [Indexed: 12/15/2022]
Abstract
The core skeletal muscle ryanodine receptor (RyR1) calcium release complex extends through three compartments of the muscle fibre, linking the extracellular environment through the cytoplasmic junctional gap to the lumen of the internal sarcoplasmic reticulum (SR) calcium store. The protein complex is essential for skeletal excitation-contraction (EC)-coupling and skeletal muscle function. Its importance is highlighted by perinatal death if any one of the EC-coupling components are missing and by myopathies associated with mutation of any of the proteins. The proteins essential for EC-coupling include the DHPR α1S subunit in the transverse tubule membrane, the DHPR β1a subunit in the cytosol and the RyR1 ion channel in the SR membrane. The other core proteins are triadin and junctin and calsequestrin, associated mainly with SR. These SR proteins are not essential for survival but exert structural and functional influences that modify the gain of EC-coupling and maintain normal muscle function. This review summarises our current knowledge of the individual protein/protein interactions within the core complex and their overall contribution to EC-coupling. We highlight significant areas that provide a continuing challenge for the field. Additional important components of the Ca2+ release complex, such as FKBP12, calmodulin, S100A1 and Stac3 are identified and reviewed elsewhere.
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Affiliation(s)
- Angela F Dulhunty
- John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
| | - Lan Wei-LaPierre
- Department of Physiology and Pharmacology, University of Rochester Medical Center, Rochester, NY, USA
| | - Marco G Casarotto
- John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
| | - Nicole A Beard
- Health Research Institute, University of Canberra, Canberra, ACT, Australia
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31
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Antioxidant Treatment Reduces Formation of Structural Cores and Improves Muscle Function in RYR1 Y522S/WT Mice. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:6792694. [PMID: 29062463 PMCID: PMC5610828 DOI: 10.1155/2017/6792694] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 06/13/2017] [Indexed: 12/27/2022]
Abstract
Central core disease (CCD) is a congenital myopathy linked to mutations in the ryanodine receptor type 1 (RYR1), the sarcoplasmic reticulum Ca2+ release channel of skeletal muscle. CCD is characterized by formation of amorphous cores within muscle fibers, lacking mitochondrial activity. In skeletal muscle of RYR1Y522S/WT knock-in mice, carrying a human mutation in RYR1 linked to malignant hyperthermia (MH) with cores, oxidative stress is elevated and fibers present severe mitochondrial damage and cores. We treated RYR1Y522S/WT mice with N-acetylcysteine (NAC), an antioxidant provided ad libitum in drinking water for either 2 or 6 months. Our results show that 2 months of NAC treatment starting at 2 months of age, when mitochondrial and fiber damage was still minimal, (i) reduce formation of unstructured and contracture cores, (ii) improve muscle function, and (iii) decrease mitochondrial damage. The beneficial effect of NAC treatment is also evident following 6 months of treatment starting at 4 months of age, when structural damage was at an advanced stage. NAC exerts its protective effect likely by lowering oxidative stress, as supported by the reduction of 3-NT and SOD2 levels. This work suggests that NAC administration is beneficial to prevent mitochondrial damage and formation of cores and improve muscle function in RYR1Y522S/WT mice.
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32
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Reduced threshold for store overload-induced Ca 2+ release is a common defect of RyR1 mutations associated with malignant hyperthermia and central core disease. Biochem J 2017; 474:2749-2761. [PMID: 28687594 DOI: 10.1042/bcj20170282] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 06/30/2017] [Accepted: 07/06/2017] [Indexed: 12/21/2022]
Abstract
Mutations in the skeletal muscle ryanodine receptor (RyR1) cause malignant hyperthermia (MH) and central core disease (CCD), whereas mutations in the cardiac ryanodine receptor (RyR2) lead to catecholaminergic polymorphic ventricular tachycardia (CPVT). Most disease-associated RyR1 and RyR2 mutations are located in the N-terminal, central, and C-terminal regions of the corresponding ryanodine receptor (RyR) isoform. An increasing body of evidence demonstrates that CPVT-associated RyR2 mutations enhance the propensity for spontaneous Ca2+ release during store Ca2+ overload, a process known as store overload-induced Ca2+ release (SOICR). Considering the similar locations of disease-associated RyR1 and RyR2 mutations in the RyR structure, we hypothesize that like CPVT-associated RyR2 mutations, MH/CCD-associated RyR1 mutations also enhance SOICR. To test this hypothesis, we determined the impact on SOICR of 12 MH/CCD-associated RyR1 mutations E2347-del, R2163H, G2434R, R2435L, R2435H, and R2454H located in the central region, and Y4796C, T4826I, L4838V, A4940T, G4943V, and P4973L located in the C-terminal region of the channel. We found that all these RyR1 mutations reduced the threshold for SOICR. Dantrolene, an acute treatment for MH, suppressed SOICR in HEK293 cells expressing the RyR1 mutants R164C, Y523S, R2136H, R2435H, and Y4796C. Interestingly, carvedilol, a commonly used β-blocker that suppresses RyR2-mediated SOICR, also inhibits SOICR in these RyR1 mutant HEK293 cells. Therefore, these results indicate that a reduced SOICR threshold is a common defect of MH/CCD-associated RyR1 mutations, and that carvedilol, like dantrolene, can suppress RyR1-mediated SOICR. Clinical studies of the effectiveness of carvedilol as a long-term treatment for MH/CCD or other RyR1-associated disorders may be warranted.
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33
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Calsequestrin depolymerizes when calcium is depleted in the sarcoplasmic reticulum of working muscle. Proc Natl Acad Sci U S A 2017; 114:E638-E647. [PMID: 28069951 DOI: 10.1073/pnas.1620265114] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Calsequestrin, the only known protein with cyclical storage and supply of calcium as main role, is proposed to have other functions, which remain unproven. Voluntary movement and the heart beat require this calcium flow to be massive and fast. How does calsequestrin do it? To bind large amounts of calcium in vitro, calsequestrin must polymerize and then depolymerize to release it. Does this rule apply inside the sarcoplasmic reticulum (SR) of a working cell? We answered using fluorescently tagged calsequestrin expressed in muscles of mice. By FRAP and imaging we monitored mobility of calsequestrin as [Ca2+] in the SR--measured with a calsequestrin-fused biosensor--was lowered. We found that calsequestrin is polymerized within the SR at rest and that it depolymerized as [Ca2+] went down: fully when calcium depletion was maximal (a condition achieved with an SR calcium channel opening drug) and partially when depletion was limited (a condition imposed by fatiguing stimulation, long-lasting depolarization, or low drug concentrations). With fluorescence and electron microscopic imaging we demonstrated massive movements of calsequestrin accompanied by drastic morphological SR changes in fully depleted cells. When cells were partially depleted no remodeling was found. The present results support the proposed role of calsequestrin in termination of calcium release by conformationally inducing closure of SR channels. A channel closing switch operated by calsequestrin depolymerization will limit depletion, thereby preventing full disassembly of the polymeric calsequestrin network and catastrophic structural changes in the SR.
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34
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Sun B, Guo W, Tian X, Yao J, Zhang L, Wang R, Chen SRW. The Cytoplasmic Region of Inner Helix S6 Is an Important Determinant of Cardiac Ryanodine Receptor Channel Gating. J Biol Chem 2016; 291:26024-26034. [PMID: 27789712 DOI: 10.1074/jbc.m116.758821] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 10/18/2016] [Indexed: 11/06/2022] Open
Abstract
The ryanodine receptor (RyR) channel pore is formed by four S6 inner helices, with its intracellular gate located at the S6 helix bundle crossing region. The cytoplasmic region of the extended S6 helix is held by the U motif of the central domain and is thought to control the opening and closing of the S6 helix bundle. However, the functional significance of the S6 cytoplasmic region in channel gating is unknown. Here we assessed the role of the S6 cytoplasmic region in the function of cardiac RyR (RyR2) via structure-guided site-directed mutagenesis. We mutated each residue in the S6 cytoplasmic region of the mouse RyR2 (4876QQEQVKEDM4884) and characterized their functional impact. We found that mutations Q4876A, V4880A, K4881A, and M4884A, located mainly on one side of the S6 helix that faces the U motif, enhanced basal channel activity and the sensitivity to Ca2+ or caffeine activation, whereas mutations Q4877A, E4878A, Q4879A, and D4883A, located largely on the opposite side of S6, suppressed channel activity. Furthermore, V4880A, a cardiac arrhythmia-associated mutation, markedly enhanced the frequency of spontaneous openings and the sensitivity to cytosolic and luminal Ca2+ activation of single RyR2 channels. V4880A also increased the propensity and reduced the threshold for arrhythmogenic spontaneous Ca2+ release in HEK293 cells. Collectively, our data suggest that interactions between the cytoplasmic region of S6 and the U motif of RyR2 are important for stabilizing the closed state of the channel. Mutations in the S6/U motif domain interface likely destabilize the closed state of RyR2, resulting in enhanced basal channel activity and sensitivity to activation and increased propensity for spontaneous Ca2+ release and cardiac arrhythmias.
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Affiliation(s)
- Bo Sun
- From the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Wenting Guo
- From the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Xixi Tian
- From the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Jinjing Yao
- From the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Lin Zhang
- From the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Ruiwu Wang
- From the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - S R Wayne Chen
- From the Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
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35
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Xiao Z, Guo W, Sun B, Hunt DJ, Wei J, Liu Y, Wang Y, Wang R, Jones PP, Back TG, Chen SRW. Enhanced Cytosolic Ca2+ Activation Underlies a Common Defect of Central Domain Cardiac Ryanodine Receptor Mutations Linked to Arrhythmias. J Biol Chem 2016; 291:24528-24537. [PMID: 27733687 DOI: 10.1074/jbc.m116.756528] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/02/2016] [Indexed: 01/21/2023] Open
Abstract
Recent three-dimensional structural studies reveal that the central domain of ryanodine receptor (RyR) serves as a transducer that converts long-range conformational changes into the gating of the channel pore. Interestingly, the central domain encompasses one of the mutation hotspots (corresponding to amino acid residues 3778-4201) that contains a number of cardiac RyR (RyR2) mutations associated with catecholaminergic polymorphic ventricular tachycardia (CPVT) and atrial fibrillation (AF). However, the functional consequences of these central domain RyR2 mutations are not well understood. To gain insights into the impact of the mutation and the role of the central domain in channel function, we generated and characterized eight disease-associated RyR2 mutations in the central domain. We found that all eight central domain RyR2 mutations enhanced the Ca2+-dependent activation of [3H]ryanodine binding, increased cytosolic Ca2+-induced fractional Ca2+ release, and reduced the activation and termination thresholds for spontaneous Ca2+ release in HEK293 cells. We also showed that racemic carvedilol and the non-beta-blocking carvedilol enantiomer, (R)-carvedilol, suppressed spontaneous Ca2+ oscillations in HEK293 cells expressing the central domain RyR2 mutations associated with CPVT and AF. These data indicate that the central domain is an important determinant of cytosolic Ca2+ activation of RyR2. These results also suggest that altered cytosolic Ca2+ activation of RyR2 represents a common defect of RyR2 mutations associated with CPVT and AF, which could potentially be suppressed by carvedilol or (R)-carvedilol.
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Affiliation(s)
- Zhichao Xiao
- From the the Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Wenting Guo
- From the the Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Bo Sun
- From the the Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Donald J Hunt
- From the the Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Jinhong Wei
- From the the Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Yingjie Liu
- From the the Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Yundi Wang
- From the the Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Ruiwu Wang
- From the the Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Peter P Jones
- the Department of Physiology, Otago School of Medical Sciences and HeartOtago, University of Otago, Dunedin 9054, New Zealand, and
| | - Thomas G Back
- the Department of Chemistry, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - S R Wayne Chen
- From the the Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta T2N 4N1, Canada,.
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Characterization of Post-Translational Modifications to Calsequestrins of Cardiac and Skeletal Muscle. Int J Mol Sci 2016; 17:ijms17091539. [PMID: 27649144 PMCID: PMC5037814 DOI: 10.3390/ijms17091539] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 09/05/2016] [Accepted: 09/08/2016] [Indexed: 11/26/2022] Open
Abstract
Calsequestrin is glycosylated and phosphorylated during its transit to its final destination in the junctional sarcoplasmic reticulum. To determine the significance and universal profile of these post-translational modifications to mammalian calsequestrin, we characterized, via mass spectrometry, the glycosylation and phosphorylation of skeletal muscle calsequestrin from cattle (B. taurus), lab mice (M. musculus) and lab rats (R. norvegicus) and cardiac muscle calsequestrin from cattle, lab rats and humans. On average, glycosylation of skeletal calsequestrin consisted of two N-acetylglucosamines and one mannose (GlcNAc2Man1), while cardiac calsequestrin had five additional mannoses (GlcNAc2Man6). Skeletal calsequestrin was not phosphorylated, while the C-terminal tails of cardiac calsequestrin contained between zero to two phosphoryls, indicating that phosphorylation of cardiac calsequestrin may be heterogeneous in vivo. Static light scattering experiments showed that the Ca2+-dependent polymerization capabilities of native bovine skeletal calsequestrin are enhanced, relative to the non-glycosylated, recombinant isoform, which our crystallographic studies suggest may be due to glycosylation providing a dynamic “guiderail”-like scaffold for calsequestrin polymerization. Glycosylation likely increases a polymerization/depolymerization response to changing Ca2+ concentrations, and proper glycosylation, in turn, guarantees both effective Ca2+ storage/buffering of the sarcoplasmic reticulum and localization of calsequestrin (Casq) at its target site.
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Yuchi Z, Van Petegem F. Ryanodine receptors under the magnifying lens: Insights and limitations of cryo-electron microscopy and X-ray crystallography studies. Cell Calcium 2016; 59:209-27. [DOI: 10.1016/j.ceca.2016.04.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 04/08/2016] [Accepted: 04/09/2016] [Indexed: 10/21/2022]
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Bamaga AK, Riazi S, Amburgey K, Ong S, Halliday W, Diamandis P, Guerguerian AM, Dowling JJ, Yoon G. Neuromuscular conditions associated with malignant hyperthermia in paediatric patients: A 25-year retrospective study. Neuromuscul Disord 2016; 26:201-6. [PMID: 26951757 DOI: 10.1016/j.nmd.2016.02.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 02/05/2016] [Accepted: 02/15/2016] [Indexed: 01/08/2023]
Abstract
Malignant Hyperthermia (MH) is a rare pharmacogenetic syndrome that can be fatal and the risk of MH in non RYR1-related disorders is unknown. We conducted a retrospective study to determine the prevalence of neuromuscular disorders among patients with MH at our centre. Patients who were admitted to the Hospital for Sick Children during the study period of January 1, 1990 to April 1, 2015 with a CK level > 8000 IU/L, or who received dantrolene, or who had a clinical diagnosis of MH were included. Medical records of 166 patients who met the inclusion criteria were reviewed and 13 patients were identified with MH-like reactions. Nine patients were classified as having true MH after review of the anaesthesia record and genetic testing results were available for 7 patients, 5 of whom had mutations in RYR1. Of the four patients who had severe reactions to anaesthesia but did not meet the criteria for true MH, two had Duchenne muscular dystrophy (DMD). In this retrospective study over 25 years, RYR1 mutations were the most common cause of MH in our cohort, and of these, one third had an underlying neuromuscular diagnosis. Genetic testing of RYR1 is indicated for all patients with MH, and anaesthetic precautions should be considered for any child with symptoms of neuromuscular disease.
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Affiliation(s)
- Ahmed K Bamaga
- Division of Neurology, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Sheila Riazi
- Malignant Hyperthermia Investigation Unit, Toronto General Hospital, Toronto, Ontario, Canada
| | - Kimberly Amburgey
- Division of Neurology, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Shaun Ong
- Division of Neurology, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - William Halliday
- Division of Pathology, Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Phedias Diamandis
- Division of Pathology, Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Anne-Marie Guerguerian
- Departments of Critical Care Medicine and Paediatrics, Neuroscience and Mental Health Program, Research Institute, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - James J Dowling
- Division of Neurology, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Grace Yoon
- Division of Neurology, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada; Division of Clinical and Metabolic Genetics, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
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Editors T. Muscle Decline in Aging and Neuromuscular Disorders - Mechanisms and Countermeasures: Terme Euganee, Padova (Italy), April 13-16, 2016. Eur J Transl Myol 2016; 26:5904. [PMID: 27054021 PMCID: PMC4821223 DOI: 10.4081/ejtm.2016.5904] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Not available.
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40
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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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Hernández-Ochoa EO, Pratt SJP, Lovering RM, Schneider MF. Critical Role of Intracellular RyR1 Calcium Release Channels in Skeletal Muscle Function and Disease. Front Physiol 2016; 6:420. [PMID: 26793121 PMCID: PMC4709859 DOI: 10.3389/fphys.2015.00420] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 12/21/2015] [Indexed: 01/25/2023] Open
Abstract
The skeletal muscle Ca2+ release channel, also known as ryanodine receptor type 1 (RyR1), is the largest ion channel protein known and is crucial for effective skeletal muscle contractile activation. RyR1 function is controlled by Cav1.1, a voltage gated Ca2+ channel that works mainly as a voltage sensor for RyR1 activity during skeletal muscle contraction and is also fine-tuned by Ca2+, several intracellular compounds (e.g., ATP), and modulatory proteins (e.g., calmodulin). Dominant and recessive mutations in RyR1, as well as acquired channel alterations, are the underlying cause of various skeletal muscle diseases. The aim of this mini review is to summarize several current aspects of RyR1 function, structure, regulation, and to describe the most common diseases caused by hereditary or acquired RyR1 malfunction.
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Affiliation(s)
- Erick O Hernández-Ochoa
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine Baltimore, MD, USA
| | - Stephen J P Pratt
- Department of Orthopaedics, University of Maryland School of Medicine Baltimore, MD, USA
| | - Richard M Lovering
- Department of Orthopaedics, University of Maryland School of Medicine Baltimore, MD, USA
| | - Martin F Schneider
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine Baltimore, MD, USA
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Furlan S, Mosole S, Murgia M, Nagaraj N, Argenton F, Volpe P, Nori A. Calsequestrins in skeletal and cardiac muscle from adult Danio rerio. J Muscle Res Cell Motil 2015; 37:27-39. [PMID: 26585961 DOI: 10.1007/s10974-015-9432-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 11/07/2015] [Indexed: 12/13/2022]
Abstract
Calsequestrin (Casq) is a high capacity, low affinity Ca(2+)-binding protein, critical for Ca(2+)-buffering in cardiac and skeletal muscle sarcoplasmic reticulum. All vertebrates have multiple genes encoding for different Casq isoforms. Increasing interest has been focused on mammalian and human Casq genes since mutations of both cardiac (Casq2) and skeletal muscle (Casq1) isoforms cause different, and sometime severe, human pathologies. Danio rerio (zebrafish) is a powerful model for studying function and mutations of human proteins. In this work, expression, biochemical properties cellular and sub-cellular localization of D. rerio native Casq isoforms are investigated. By quantitative PCR, three mRNAs were detected in skeletal muscle and heart with different abundances. Three zebrafish Casqs: Casq1a, Casq1b and Casq2 were identified by mass spectrometry (Data are available via ProteomeXchange with identifier PXD002455). Skeletal and cardiac zebrafish calsequestrins share properties with mammalian Casq1 and Casq2. Skeletal Casqs were found primarily, but not exclusively, at the sarcomere Z-line level where terminal cisternae of sarcoplasmic reticulum are located.
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Affiliation(s)
- Sandra Furlan
- Institute of Neuroscience Consiglio Nazionale delle Ricerche, Viale G. Colombo 3, 35121, Padua, Italy
| | - Simone Mosole
- Department of Biomedical Sciences, Istituto Interuniversitario di Miologia, University of Padova, Viale G. Colombo 3, 35121, Padua, Italy
| | - Marta Murgia
- Department of Biomedical Sciences, Istituto Interuniversitario di Miologia, University of Padova, Viale G. Colombo 3, 35121, Padua, Italy
- Department of Proteomics and Signal Transduction, Max-Planck-Institute of Biochemistry, Am Klopferspitz 18, 82152, Martinsried, Germany
| | - Nagarjuna Nagaraj
- Department of Proteomics and Signal Transduction, Max-Planck-Institute of Biochemistry, Am Klopferspitz 18, 82152, Martinsried, Germany
| | - Francesco Argenton
- Department of Biology, University of Padova, Via U.Bassi 58/B, 35121, Padua, Italy
| | - Pompeo Volpe
- Institute of Neuroscience Consiglio Nazionale delle Ricerche, Viale G. Colombo 3, 35121, Padua, Italy
- Department of Biomedical Sciences, Istituto Interuniversitario di Miologia, University of Padova, Viale G. Colombo 3, 35121, Padua, Italy
| | - Alessandra Nori
- Department of Biomedical Sciences, Istituto Interuniversitario di Miologia, University of Padova, Viale G. Colombo 3, 35121, Padua, Italy.
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Manno C, Ríos E. A better method to measure total calcium in biological samples yields immediate payoffs. ACTA ACUST UNITED AC 2015; 145:167-71. [PMID: 25712015 PMCID: PMC4338160 DOI: 10.1085/jgp.201511370] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Carlo Manno
- Department of Molecular Biophysics and Physiology, Section of Cellular Signaling, Rush University, Chicago, IL 60612
| | - Eduardo Ríos
- Department of Molecular Biophysics and Physiology, Section of Cellular Signaling, Rush University, Chicago, IL 60612
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44
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Ferretti R, Marques MJ, Khurana TS, Santo Neto H. Expression of calcium-buffering proteins in rat intrinsic laryngeal muscles. Physiol Rep 2015; 3:3/6/e12409. [PMID: 26109185 PMCID: PMC4510619 DOI: 10.14814/phy2.12409] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Intrinsic laryngeal muscles (ILM) are highly specialized muscles involved in phonation and airway protection, with unique properties that allow them to perform extremely rapid contractions and to escape from damage in muscle dystrophy. Due to that, they may differ from limb muscles in several physiological aspects. Because a better ability to handle intracellular calcium has been suggested to explain ILM unique properties, we hypothesized that the profile of the proteins that regulate calcium levels in ILM is different from that in a limb muscle. Calcium-related proteins were analyzed in the ILM, cricothyroid (CT), and tibialis anterior (TA) muscles from male Sprague–Dawley rats (8 weeks of age) using quantitative PCR and western blotting. Higher expression of key Ca2+ regulatory proteins was detected in ILM compared to TA, such as the sarcoplasmic reticulum (SR) Ca2+-reuptake proteins (Sercas 1 and 2), the Na+/Ca2+ exchanger, phospholamban, and the Ca2+-binding protein calsequestrin. Parvalbumin, calmodulin and the ATPase, Ca2+-transporting, and plasma membrane 1 were also expressed at higher levels in ILM compared to TA. The store-operated calcium entry channel molecule was decreased in ILM compared to the limb muscle and the voltage-dependent L-type and ryanodine receptor were expressed at similar levels in ILM and TA. These results show that ILM have a calcium regulation system profile suggestive of a better ability to handle calcium changes in comparison to limb muscles, and this may provide a mechanistic insight for their unique pathophysiological properties.
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Affiliation(s)
- Renato Ferretti
- Departamento de Anatomia, Instituto de Biociencias de Botucatu, Universidade Estadual Paulista, Botucatu São Paulo, Brazil
| | - Maria Julia Marques
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas, Campinas São Paulo, Brazil
| | - Tejvir S Khurana
- Department of Physiology, Perelman School of Medicine and Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Humberto Santo Neto
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas, Campinas São Paulo, Brazil
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Wang L, Zhang L, Li S, Zheng Y, Yan X, Chen M, Wang H, Putney JW, Luo D. Retrograde regulation of STIM1-Orai1 interaction and store-operated Ca2+ entry by calsequestrin. Sci Rep 2015; 5:11349. [PMID: 26087026 PMCID: PMC4471903 DOI: 10.1038/srep11349] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 05/22/2015] [Indexed: 12/13/2022] Open
Abstract
Interaction between the endoplasmic reticulum (ER)-located stromal interaction molecue1 (STIM1) and the plasma membrane-located Ca2+ channel subunit, Orai1, underlies store-operated Ca2+ entry (SOCE). Calsequestrin1 (CSQ1), a sarcoplasmic reticulum Ca2+ buffering protein, inhibits SOCE, but the mechanism of action is unknown. We identified an interaction between CSQ1 and STIM1 in HEK293 cells. An increase in monomeric CSQ1 induced by depleted Ca2+ stores, or trifluoperazine (TFP), a blocker of CSQ folding and aggregation, enhanced the CSQ1-STIM1 interaction. In cells with Ca2+ stores depleted, TFP further increased CSQ1 monomerization and CSQ1-STIM1 interaction, but reduced the association of STIM1 with Orai1 and SOCE. Over-expression of CSQ1 or a C-terminal (amino acid 388–396) deletion mutant significantly promoted the association of CSQ1 with STIM1, but suppressed both STIM1-Orai1 interaction and SOCE, while over-expression of the C-terminal (amino acid 362–396) deletion mutant had no effect. The physical interaction between low polymeric forms of CSQ1 and STIM1 likely acts by interfering with STIM1 oligimerization and inhibits STIM1-Orai1 interaction, providing a brake to SOCE under physiological conditions. This novel regulatory mechanism for SOCE may also contribute to the pathological Ca2+ overload in calsequestrin deficient diseases, such as malignant hyperthermia and ventricular tachycardia.
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Affiliation(s)
- Limin Wang
- Department of Pharmacology, Capital Medical University, Beijing 100069, P.R. China
| | - Lane Zhang
- Department of Pharmacology, Capital Medical University, Beijing 100069, P.R. China
| | - Shu Li
- Department of Pharmacology, Capital Medical University, Beijing 100069, P.R. China
| | - Yuanyuan Zheng
- Department of Pharmacology, Capital Medical University, Beijing 100069, P.R. China
| | - Xinxin Yan
- Department of Pharmacology, Capital Medical University, Beijing 100069, P.R. China
| | - Min Chen
- Department of Pharmacology, Capital Medical University, Beijing 100069, P.R. China
| | - Haoyang Wang
- Department of Pharmacology, Capital Medical University, Beijing 100069, P.R. China
| | - James W Putney
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Dali Luo
- Department of Pharmacology, Capital Medical University, Beijing 100069, P.R. China
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Paolini C, Quarta M, Wei-LaPierre L, Michelucci A, Nori A, Reggiani C, Dirksen RT, Protasi F. Oxidative stress, mitochondrial damage, and cores in muscle from calsequestrin-1 knockout mice. Skelet Muscle 2015; 5:10. [PMID: 26075051 PMCID: PMC4464246 DOI: 10.1186/s13395-015-0035-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 03/19/2015] [Indexed: 12/17/2022] Open
Abstract
Background Mutations in the gene encoding ryanodine receptor type-1 (RYR1), the calcium ion (Ca2+) release channel in the sarcoplasmic reticulum (SR) of skeletal muscle, are linked to central core disease (CCD) and malignant hyperthermia (MH) susceptibility. We recently reported that mice lacking the skeletal isoform of calsequestrin (CASQ1-null), the primary Ca2+ buffer in the SR of skeletal muscle and a modulator of RYR1 activity, exhibit lethal heat- and anesthetic-induced hypermetabolic episodes that resemble MH events in humans. Methods We compared ultrastructure, oxidative status, and contractile function in skeletal fibers of extensor digitorum longus (EDL) muscles in wild type (WT) and CASQ1-null mice at different ages (from 4 to 27 months) using structural, biochemical, and functional assays. Results About 25% of fibers in EDL muscles from CASQ1-null mice of 14 to 27 months of age exhibited large areas of structural disarray (named core-like regions), which were rarely observed in muscle from age-matched WT mice. To determine early events that may lead to the formation of cores, we analyzed EDL muscles from adult mice: at 4 to 6 months of age, CASQ1-null mice (compared to WT) displayed significantly reduced grip strength (40 ± 1 vs. 86 ± 1 mN/gr) and exhibited an increase in the percentage of damaged mitochondria (15.1% vs. 2.6%) and a decrease in average cross-sectional fiber area (approximately 37%) in EDL fibers. Finally, oxidative stress was also significantly increased (25% reduction in ratio between reduced and oxidized glutathione, or GSH/GSSG, and 35% increase in production of mitochondrial superoxide flashes). Providing ad libitum access to N-acetylcysteine in the drinking water for 2 months normalized GSH/GSSG ratio, reduced mitochondrial damage (down to 8.9%), and improved grip strength (from 46 ± 3 to 59 ± 2 mN/gr) in CASQ1-null mice. Conclusions Our findings: 1) demonstrate that ablation of CASQ1 leads to enhanced oxidative stress, mitochondrial damage, and the formation of structural cores in skeletal muscle; 2) provide new insights in the pathogenic mechanisms that lead to damage/disappearance of mitochondria in cores; and 3) suggest that antioxidants may provide some therapeutic benefit in reducing mitochondrial damage, limiting the development of cores, and improving muscle function. Electronic supplementary material The online version of this article (doi:10.1186/s13395-015-0035-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Cecilia Paolini
- CeSI - Center for Research on Ageing & DNICS - Department of Neuroscience, Imaging and Clinical Sciences, University G. d'Annunzio, Via L. Polacchi, 11, I-66013 Chieti, Italy
| | - Marco Quarta
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58/B, I-35131 Padova, Italy ; Department of Neurology and Neurological Sciences, Stanford University, 450 Serra Mall, Stanford, CA 94305 USA
| | - Lan Wei-LaPierre
- Department of Pharmacology and Physiology, University of Rochester Medical Center, 601 Elmwood Ave., Rochester, NY 14642 USA
| | - Antonio Michelucci
- CeSI - Center for Research on Ageing & DNICS - Department of Neuroscience, Imaging and Clinical Sciences, University G. d'Annunzio, Via L. Polacchi, 11, I-66013 Chieti, Italy
| | - Alessandra Nori
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58/B, I-35131 Padova, Italy
| | - Carlo Reggiani
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58/B, I-35131 Padova, Italy
| | - Robert T Dirksen
- Department of Pharmacology and Physiology, University of Rochester Medical Center, 601 Elmwood Ave., Rochester, NY 14642 USA
| | - Feliciano Protasi
- CeSI - Center for Research on Ageing & DNICS - Department of Neuroscience, Imaging and Clinical Sciences, University G. d'Annunzio, Via L. Polacchi, 11, I-66013 Chieti, Italy
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47
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Hunter JM, Ahearn ME, Balak CD, Liang WS, Kurdoglu A, Corneveaux JJ, Russell M, Huentelman MJ, Craig DW, Carpten J, Coons SW, DeMello DE, Hall JG, Bernes SM, Baumbach-Reardon L. Novel pathogenic variants and genes for myopathies identified by whole exome sequencing. Mol Genet Genomic Med 2015; 3:283-301. [PMID: 26247046 PMCID: PMC4521965 DOI: 10.1002/mgg3.142] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 02/19/2015] [Accepted: 02/26/2015] [Indexed: 12/25/2022] Open
Abstract
Neuromuscular diseases (NMD) account for a significant proportion of infant and childhood mortality and devastating chronic disease. Determining the specific diagnosis of NMD is challenging due to thousands of unique or rare genetic variants that result in overlapping phenotypes. We present four unique childhood myopathy cases characterized by relatively mild muscle weakness, slowly progressing course, mildly elevated creatine phosphokinase (CPK), and contractures. We also present two additional cases characterized by severe prenatal/neonatal myopathy. Prior extensive genetic testing and histology of these cases did not reveal the genetic etiology of disease. Here, we applied whole exome sequencing (WES) and bioinformatics to identify likely causal pathogenic variants in each pedigree. In two cases, we identified novel pathogenic variants in COL6A3. In a third case, we identified novel likely pathogenic variants in COL6A6 and COL6A3. We identified a novel splice variant in EMD in a fourth case. Finally, we classify two cases as calcium channelopathies with identification of novel pathogenic variants in RYR1 and CACNA1S. These are the first cases of myopathies reported to be caused by variants in COL6A6 and CACNA1S. Our results demonstrate the utility and genetic diagnostic value of WES in the broad class of NMD phenotypes.
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Affiliation(s)
- Jesse M Hunter
- Integrated Cancer Genomics, Translational Genomics Research Institute (TGen) Phoenix, Arizona
| | - Mary Ellen Ahearn
- Integrated Cancer Genomics, Translational Genomics Research Institute (TGen) Phoenix, Arizona
| | - Christopher D Balak
- Integrated Cancer Genomics, Translational Genomics Research Institute (TGen) Phoenix, Arizona
| | - Winnie S Liang
- Collaborative Sequencing Center, Translational Genomics Research Institute (TGen) Phoenix, Arizona
| | - Ahmet Kurdoglu
- Center for Bioinformatics, Translational Genomics Research Institute (TGen) Phoenix, Arizona
| | - Jason J Corneveaux
- Neurogenomics, Translational Genomics Research Institute (TGen) Phoenix, Arizona
| | - Megan Russell
- Center for Bioinformatics, Translational Genomics Research Institute (TGen) Phoenix, Arizona
| | - Matthew J Huentelman
- Neurogenomics, Translational Genomics Research Institute (TGen) Phoenix, Arizona
| | - David W Craig
- Neurogenomics, Translational Genomics Research Institute (TGen) Phoenix, Arizona
| | - John Carpten
- Integrated Cancer Genomics, Translational Genomics Research Institute (TGen) Phoenix, Arizona
| | - Stephen W Coons
- Section of Neuropathology, Barrow Neurological Institute Phoenix, Arizona
| | - Daphne E DeMello
- Division of Neurology, Phoenix Children's Hospital Phoenix, Arizona
| | - Judith G Hall
- Departments of Medical Genetics and Pediatrics, University of British Columbia Vancouver, British Columbia, Canada
| | - Saunder M Bernes
- Division of Neurology, Phoenix Children's Hospital Phoenix, Arizona
| | - Lisa Baumbach-Reardon
- Integrated Cancer Genomics, Translational Genomics Research Institute (TGen) Phoenix, Arizona
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Potts LE, Longwell JJ, Bedocs P, Sambuughin N, Bina S, Cooper PB, Carroll CG, O'Connor F, Deuster P, Muldoon SM, Hamilton S, Capacchione JF. Improving awareness of nonanesthesia-related malignant hyperthermia presentations: a tale of two brothers. ACTA ACUST UNITED AC 2015; 3:23-6. [PMID: 25611019 DOI: 10.1213/xaa.0000000000000043] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A 30-year-old man developed unexplained rhabdomyolysis, persistently increased creatine kinase and severe debilitating muscle cramps. After a nondiagnostic neurologic evaluation, he was referred for a muscle biopsy, to include histology/histochemistry, a myoglobinuria panel, and a caffeine halothane contracture test. Only the caffeine halothane contracture test was positive, and a subsequent ryanodine receptor type 1 gene evaluation revealed a mutation functionally causative for malignant hyperthermia. His identical twin brother, who was suffering from similar complaints, was found to share the same mutation. They each require oral dantrolene therapy to control symptoms, despite difficulty in identifying health care providers familiar with treating this disorder.
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Affiliation(s)
- Lauren E Potts
- From the *Department of Anesthesiology, Walter Reed National Military Medical Center, Bethesda; †DVCIPM, Rockville; ‡Department of Anesthesiology, Uniformed Services University of the Health Sciences; Departments of §Neurosurgery and ‖Neurology, Walter Reed National Military Medical Center, Bethesda, Maryland; ¶Department of Military Medicine, Uniformed Services University of the Health Sciences; and **Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas
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Liu Y, Sun B, Xiao Z, Wang R, Guo W, Zhang JZ, Mi T, Wang Y, Jones PP, Van Petegem F, Chen SRW. Roles of the NH2-terminal domains of cardiac ryanodine receptor in Ca2+ release activation and termination. J Biol Chem 2015; 290:7736-46. [PMID: 25627681 DOI: 10.1074/jbc.m114.618827] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The NH2-terminal region (residues 1-543) of the cardiac ryanodine receptor (RyR2) harbors a large number of mutations associated with cardiac arrhythmias and cardiomyopathies. Functional studies have revealed that the NH2-terminal region is involved in the activation and termination of Ca(2+) release. The three-dimensional structure of the NH2-terminal region has recently been solved. It is composed of three domains (A, B, and C). However, the roles of these individual domains in Ca(2+) release activation and termination are largely unknown. To understand the functional significance of each of these NH2-terminal domains, we systematically deleted these domains and assessed their impact on caffeine- or Ca(2+)-induced Ca(2+) release and store overload-induced Ca(2+) release (SOICR) in HEK293 cells. We found that all deletion mutants were capable of forming caffeine- and ryanodine-sensitive functional channels, indicating that the NH2-terminal region is not essential for channel gating. Ca(2+) release measurements revealed that deleting domain A markedly reduced the threshold for SOICR termination but had no effect on caffeine or Ca(2+) activation or the threshold for SOICR activation, whereas deleting domain B substantially enhanced caffeine and Ca(2+) activation and lowered the threshold for SOICR activation and termination. Conversely, deleting domain C suppressed caffeine activation, abolished Ca(2+) activation and SOICR, and diminished protein expression. These results suggest that domain A is involved in channel termination, domain B is involved in channel suppression, and domain C is critical for channel activation and expression. Our data shed new insights into the structure-function relationship of the NH2-terminal domains of RyR2 and the action of NH2-terminal disease mutations.
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Affiliation(s)
- Yingjie Liu
- From the Libin Cardiovascular Institute of Alberta, Departments of Physiology and Pharmacology and Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Bo Sun
- From the Libin Cardiovascular Institute of Alberta, Departments of Physiology and Pharmacology and Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Zhichao Xiao
- From the Libin Cardiovascular Institute of Alberta, Departments of Physiology and Pharmacology and Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Ruiwu Wang
- From the Libin Cardiovascular Institute of Alberta, Departments of Physiology and Pharmacology and Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Wenting Guo
- From the Libin Cardiovascular Institute of Alberta, Departments of Physiology and Pharmacology and Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Joe Z Zhang
- Department of Physiology and HeartOtago, University of Otago, Dunedin 9054, New Zealand, and
| | - Tao Mi
- From the Libin Cardiovascular Institute of Alberta, Departments of Physiology and Pharmacology and Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Yundi Wang
- From the Libin Cardiovascular Institute of Alberta, Departments of Physiology and Pharmacology and Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Peter P Jones
- Department of Physiology and HeartOtago, University of Otago, Dunedin 9054, New Zealand, and
| | - Filip Van Petegem
- Cardiovascular Research Group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - S R Wayne Chen
- From the Libin Cardiovascular Institute of Alberta, Departments of Physiology and Pharmacology and Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 4N1, Canada,
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50
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Zvaritch E, MacLennan DH. Muscle spindles exhibit core lesions and extensive degeneration of intrafusal fibers in the Ryr1(I4895T/wt) mouse model of core myopathy. Biochem Biophys Res Commun 2015; 460:34-9. [PMID: 25619131 DOI: 10.1016/j.bbrc.2015.01.056] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 01/13/2015] [Indexed: 11/15/2022]
Abstract
Muscle spindles from the hind limb muscles of adult Ryr1(I4895T/wt) (IT/+) mice exhibit severe structural abnormalities. Up to 85% of the spindles are separated from skeletal muscle fascicles by a thick layer of connective tissue. Many intrafusal fibers exhibit degeneration, with Z-line streaming, compaction and collapse of myofibrillar bundles, mitochondrial clumping, nuclear shrinkage and pyknosis. The lesions resemble cores observed in the extrafusal myofibers of this animal model and of core myopathy patients. Spindle abnormalities precede those in extrafusal fibers, indicating that they are a primary pathological feature in this murine Ryr1-related core myopathy. Muscle spindle involvement, if confirmed for human core myopathy patients, would provide an explanation for an array of devastating clinical features characteristic of these diseases and provide novel insights into the pathology of RYR1-related myopathies.
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Affiliation(s)
- Elena Zvaritch
- Banting and Best Department of Medical Research, University of Toronto, Charles H. Best Institute, 112 College Street, Toronto, ON M5G 1L6, Canada
| | - David H MacLennan
- Banting and Best Department of Medical Research, University of Toronto, Charles H. Best Institute, 112 College Street, Toronto, ON M5G 1L6, Canada.
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