1
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Campiglio M, Dyrda A, Tuinte WE, Török E. Ca V1.1 Calcium Channel Signaling Complexes in Excitation-Contraction Coupling: Insights from Channelopathies. Handb Exp Pharmacol 2023; 279:3-39. [PMID: 36592225 DOI: 10.1007/164_2022_627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
In skeletal muscle, excitation-contraction (EC) coupling relies on the mechanical coupling between two ion channels: the L-type voltage-gated calcium channel (CaV1.1), located in the sarcolemma and functioning as the voltage sensor of EC coupling, and the ryanodine receptor 1 (RyR1), located on the sarcoplasmic reticulum serving as the calcium release channel. To this day, the molecular mechanism by which these two ion channels are linked remains elusive. However, recently, skeletal muscle EC coupling could be reconstituted in heterologous cells, revealing that only four proteins are essential for this process: CaV1.1, RyR1, and the cytosolic proteins CaVβ1a and STAC3. Due to the crucial role of these proteins in skeletal muscle EC coupling, any mutation that affects any one of these proteins can have devastating consequences, resulting in congenital myopathies and other pathologies.Here, we summarize the current knowledge concerning these four essential proteins and discuss the pathophysiology of the CaV1.1, RyR1, and STAC3-related skeletal muscle diseases with an emphasis on the molecular mechanisms. Being part of the same signalosome, mutations in different proteins often result in congenital myopathies with similar symptoms or even in the same disease.
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Affiliation(s)
- Marta Campiglio
- Institute of Physiology, Medical University Innsbruck, Innsbruck, Austria.
| | - Agnieszka Dyrda
- Institute of Physiology, Medical University Innsbruck, Innsbruck, Austria
| | - Wietske E Tuinte
- Institute of Physiology, Medical University Innsbruck, Innsbruck, Austria
| | - Enikő Török
- Institute of Physiology, Medical University Innsbruck, Innsbruck, Austria
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2
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Verdile V, Guizzo G, Ferrante G, Paronetto MP. RNA Targeting in Inherited Neuromuscular Disorders: Novel Therapeutic Strategies to Counteract Mis-Splicing. Cells 2021; 10:cells10112850. [PMID: 34831073 PMCID: PMC8616048 DOI: 10.3390/cells10112850] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/08/2021] [Accepted: 10/18/2021] [Indexed: 01/14/2023] Open
Abstract
Neuromuscular disorders represent multifaceted abnormal conditions, with little or no cure, leading to patient deaths from complete muscle wasting and atrophy. Despite strong efforts in the past decades, development of effective treatments is still urgently needed. Advent of next-generation sequencing technologies has allowed identification of novel genes and mutations associated with neuromuscular pathologies, highlighting splicing defects as essential players. Deciphering the significance and relative contributions of defective RNA metabolism will be instrumental to address and counteract these malignancies. We review here recent progress on the role played by alternative splicing in ensuring functional neuromuscular junctions (NMJs), and its involvement in the pathogenesis of NMJ-related neuromuscular disorders, with particular emphasis on congenital myasthenic syndromes and muscular dystrophies. We will also discuss novel strategies based on oligonucleotides designed to bind their cognate sequences in the RNA or targeting intermediary of mRNA metabolism. These efforts resulted in several chemical classes of RNA molecules that have recently proven to be clinically effective, more potent and better tolerated than previous strategies.
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Affiliation(s)
- Veronica Verdile
- Laboratory of Molecular and Cellular Neurobiology, Fondazione Santa Lucia, CERC, 00143 Rome, Italy; (V.V.); (G.G.); (G.F.)
- Department of Movement, Human and Health Sciences, University of Rome Foro Italico, Piazza Lauro de Bosis 6, 00135 Rome, Italy
| | - Gloria Guizzo
- Laboratory of Molecular and Cellular Neurobiology, Fondazione Santa Lucia, CERC, 00143 Rome, Italy; (V.V.); (G.G.); (G.F.)
| | - Gabriele Ferrante
- Laboratory of Molecular and Cellular Neurobiology, Fondazione Santa Lucia, CERC, 00143 Rome, Italy; (V.V.); (G.G.); (G.F.)
| | - Maria Paola Paronetto
- Laboratory of Molecular and Cellular Neurobiology, Fondazione Santa Lucia, CERC, 00143 Rome, Italy; (V.V.); (G.G.); (G.F.)
- Department of Movement, Human and Health Sciences, University of Rome Foro Italico, Piazza Lauro de Bosis 6, 00135 Rome, Italy
- Correspondence:
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3
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Grande V, Hathazi D, O'Connor E, Marteau T, Schara-Schmidt U, Hentschel A, Gourdon G, Nikolenko N, Lochmüller H, Roos A. Dysregulation of GSK3β-Target Proteins in Skin Fibroblasts of Myotonic Dystrophy Type 1 (DM1) Patients. J Neuromuscul Dis 2021; 8:603-619. [PMID: 33682722 DOI: 10.3233/jnd-200558] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Myotonic dystrophy type 1 (DM1) is the most common monogenetic muscular disorder of adulthood. This multisystemic disease is caused by CTG repeat expansion in the 3'-untranslated region of the DM1 protein kinase gene called DMPK. DMPK encodes a myosin kinase expressed in skeletal muscle cells and other cellular populations such as smooth muscle cells, neurons and fibroblasts. The resultant expanded (CUG)n RNA transcripts sequester RNA binding factors leading to ubiquitous and persistent splicing deregulation. The accumulation of mutant CUG repeats is linked to increased activity of glycogen synthase kinase 3 beta (GSK3β), a highly conserved and ubiquitous serine/threonine kinase with functions in pathways regulating inflammation, metabolism, oncogenesis, neurogenesis and myogenesis. As GSK3β-inhibition ameliorates defects in myogenesis, muscle strength and myotonia in a DM1 mouse model, this kinase represents a key player of DM1 pathobiochemistry and constitutes a promising therapeutic target. To better characterise DM1 patients, and monitor treatment responses, we aimed to define a set of robust disease and severity markers linked to GSK3βby unbiased proteomic profiling utilizing fibroblasts derived from DM1 patients with low (80- 150) and high (2600- 3600) CTG-repeats. Apart from GSK3β increase, we identified dysregulation of nine proteins (CAPN1, CTNNB1, CTPS1, DNMT1, HDAC2, HNRNPH3, MAP2K2, NR3C1, VDAC2) modulated by GSK3β. In silico-based expression studies confirmed expression in neuronal and skeletal muscle cells and revealed a relatively elevated abundance in fibroblasts. The potential impact of each marker in the myopathology of DM1 is discussed based on respective function to inform potential uses as severity markers or for monitoring GSK3β inhibitor treatment responses.
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Affiliation(s)
- Valentina Grande
- Department of Neuropediatrics, University Hospital Essen, Duisburg-Essen University, Germany
| | - Denisa Hathazi
- Leibniz-Institut für Analytische Wissenschaften -ISAS- e.V., Dortmund, Germany.,Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Emily O'Connor
- Childrens Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON, Canada
| | - Theo Marteau
- Department of Neuropediatrics, University Hospital Essen, Duisburg-Essen University, Germany
| | - Ulrike Schara-Schmidt
- Department of Neuropediatrics, University Hospital Essen, Duisburg-Essen University, Germany
| | - Andreas Hentschel
- Leibniz-Institut für Analytische Wissenschaften -ISAS- e.V., Dortmund, Germany
| | - Genevieve Gourdon
- Centre de Recherche en Myologie, Association Institut de Myologie, Sorbonne Université, Inserm UMR 974, Paris, France
| | - Nikoletta Nikolenko
- National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London, UK
| | - Hanns Lochmüller
- Childrens Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON, Canada.,Division of Neurology, Department of Medicine, The Ottawa Hospital, Ottawa, ON, Canada.,Department of Neuropediatrics and Muscle Disorders, Faculty of Medicine, Medical Center - University of Freiburg, Freiburg, Germany.,Centro Nacional de AnálisisGenómico, Center for Genomic Regulation (CNAG-CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Catalonia, Spain
| | - Andreas Roos
- Department of Neuropediatrics, University Hospital Essen, Duisburg-Essen University, Germany.,Childrens Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON, Canada
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4
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Santoro M, Piacentini R, Perna A, Pisano E, Severino A, Modoni A, Grassi C, Silvestri G. Resveratrol corrects aberrant splicing of RYR1 pre-mRNA and Ca 2+ signal in myotonic dystrophy type 1 myotubes. Neural Regen Res 2020; 15:1757-1766. [PMID: 32209783 PMCID: PMC7437583 DOI: 10.4103/1673-5374.276336] [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] [Indexed: 12/29/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a spliceopathy related to the mis-splicing of several genes caused by sequestration of nuclear transcriptional RNA-binding factors from non-coding CUG repeats of DMPK pre-mRNAs. Dysregulation of ryanodine receptor 1 (RYR1), sarcoplasmatic/endoplasmatic Ca2+-ATPase (SERCA) and α1S subunit of voltage-gated Ca2+ channels (Cav1.1) is related to Ca2+ homeostasis and excitation-contraction coupling impairment. Though no pharmacological treatment for DM1 exists, aberrant splicing correction represents one major therapeutic target for this disease. Resveratrol (RES, 3,5,4′-trihydroxy-trans-stilbene) is a promising pharmacological tools for DM1 treatment for its ability to directly bind the DNA and RNA influencing gene expression and alternative splicing. Herein, we analyzed the therapeutic effects of RES in DM1 myotubes in a pilot study including cultured myotubes from two DM1 patients and two healthy controls. Our results indicated that RES treatment corrected the aberrant splicing of RYR1, and this event appeared associated with restoring of depolarization-induced Ca2+ release from RYR1 dependent on the electro-mechanical coupling between RYR1 and Cav1.1. Interestingly, immunoblotting studies showed that RES treatment was associated with a reduction in the levels of CUGBP Elav-like family member 1, while RYR1, Cav1.1 and SERCA1 protein levels were unchanged. Finally, RES treatment did not induce any major changes either in the amount of ribonuclear foci or sequestration of muscleblind-like splicing regulator 1. Overall, the results of this pilot study would support RES as an attractive compound for future clinical trials in DM1. Ethical approval was obtained from the Ethical Committee of IRCCS Fondazione Policlinico Universitario A. Gemelli, Rome, Italy (rs9879/14) on May 20, 2014.
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Affiliation(s)
| | - Roberto Piacentini
- Department of Neuroscience, Università Cattolica del Sacro Cuore; Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Alessia Perna
- Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Eugenia Pisano
- Department of Cardiovascular and Thoracic Sciences, Università Cattolica del Sacro Cuore; Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Anna Severino
- Department of Cardiovascular and Thoracic Sciences, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Anna Modoni
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Claudio Grassi
- Department of Neuroscience, Università Cattolica del Sacro Cuore; Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Gabriella Silvestri
- Department of Neuroscience, Università Cattolica del Sacro Cuore; Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
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5
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Shields RK, Lee J, Buelow A, Petrie M, Dudley-Javoroski S, Cross S, Gutmann L, Nopoulos PC. Myotonic dystrophy type 1 alters muscle twitch properties, spinal reflexes, and perturbation-induced trans-cortical reflexes. Muscle Nerve 2019; 61:205-212. [PMID: 31773755 DOI: 10.1002/mus.26767] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 11/20/2019] [Accepted: 11/23/2019] [Indexed: 12/29/2022]
Abstract
BACKGROUND Neurophysiologic biomarkers are needed for clinical trials of therapies for myotonic dystrophy (DM1). We characterized muscle properties, spinal reflexes (H-reflexes), and trans-cortical long-latency reflexes (LLRs) in a cohort with mild/moderate DM1. METHODS Twenty-four people with DM1 and 25 matched controls underwent assessment of tibial nerve H-reflexes and soleus muscle twitch properties. Quadriceps LLRs were elicited by delivering an unexpected perturbation during a single-limb squat (SLS) visuomotor tracking task. RESULTS DM1 was associated with decreased H-reflex depression. The efficacy of doublet stimulation was enhanced, yielding an elevated double-single twitch ratio. DM1 participants demonstrated greater error during the SLS task. DM1 individuals with the least-robust LLR responses showed the greatest loss of spinal H-reflex depression. CONCLUSIONS DM1 is associated with abnormalities of muscle twitch properties. Co-occurring alterations of spinal and trans-cortical reflex properties underscore the central nervous system manifestations of this disorder and may assist in gauging efficacy during clinical trials.
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Affiliation(s)
- Richard K Shields
- Department of Physical Therapy and Rehabilitation Science, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Jinhyun Lee
- Department of Physical Therapy and Rehabilitation Science, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Aaron Buelow
- Department of Physical Therapy and Rehabilitation Science, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Michael Petrie
- Department of Physical Therapy and Rehabilitation Science, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Shauna Dudley-Javoroski
- Department of Physical Therapy and Rehabilitation Science, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Stephen Cross
- Department of Psychiatry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Laurie Gutmann
- Department of Neurology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Peggy C Nopoulos
- Department of Psychiatry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
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6
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Kim EY, Barefield DY, Vo AH, Gacita AM, Schuster EJ, Wyatt EJ, Davis JL, Dong B, Sun C, Page P, Dellefave-Castillo L, Demonbreun A, Zhang HF, McNally EM. Distinct pathological signatures in human cellular models of myotonic dystrophy subtypes. JCI Insight 2019; 4:122686. [PMID: 30730308 DOI: 10.1172/jci.insight.122686] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 01/31/2019] [Indexed: 01/06/2023] Open
Abstract
Myotonic dystrophy (DM) is the most common autosomal dominant muscular dystrophy and encompasses both skeletal muscle and cardiac complications. DM is nucleotide repeat expansion disorder in which type 1 (DM1) is due to a trinucleotide repeat expansion on chromosome 19 and type 2 (DM2) arises from a tetranucleotide repeat expansion on chromosome 3. Developing representative models of DM in animals has been challenging due to instability of nucleotide repeat expansions, especially for DM2, which is characterized by nucleotide repeat expansions often greater than 5,000 copies. To investigate mechanisms of human DM, we generated cellular models of DM1 and DM2. We used regulated MyoD expression to reprogram urine-derived cells into myotubes. In this myogenic cell model, we found impaired dystrophin expression, in the presence of muscleblind-like 1 (MBNL1) foci, and aberrant splicing in DM1 but not in DM2 cells. We generated induced pluripotent stem cells (iPSC) from healthy controls and DM1 and DM2 subjects, and we differentiated these into cardiomyocytes. DM1 and DM2 cells displayed an increase in RNA foci concomitant with cellular differentiation. iPSC-derived cardiomyocytes from DM1 but not DM2 had aberrant splicing of known target genes and MBNL sequestration. High-resolution imaging revealed tight association between MBNL clusters and RNA foci in DM1. Ca2+ transients differed between DM1- and DM2 iPSC-derived cardiomyocytes, and each differed from healthy control cells. RNA-sequencing from DM1- and DM2 iPSC-derived cardiomyocytes revealed distinct misregulation of gene expression, as well as differential aberrant splicing patterns. Together, these data support that DM1 and DM2, despite some shared clinical and molecular features, have distinct pathological signatures.
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Affiliation(s)
- Ellis Y Kim
- Molecular Pathogenesis and Molecular Medicine, The University of Chicago, Chicago, Illinois, USA
| | - David Y Barefield
- Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Andy H Vo
- Committee on Development, Regeneration, and Stem Cell Biology, The University of Chicago, Chicago, Illinois, USA
| | - Anthony M Gacita
- Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Emma J Schuster
- Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Eugene J Wyatt
- Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | | | - Biqin Dong
- Department of Biomedical Engineering and.,Department of Mechanical Engineering, Northwestern University, Evanston, Illinois, USA
| | - Cheng Sun
- Department of Mechanical Engineering, Northwestern University, Evanston, Illinois, USA
| | - Patrick Page
- Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Lisa Dellefave-Castillo
- Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Alexis Demonbreun
- Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | | | - Elizabeth M McNally
- Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
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7
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Cerro-Herreros E, Sabater-Arcis M, Fernandez-Costa JM, Moreno N, Perez-Alonso M, Llamusi B, Artero R. miR-23b and miR-218 silencing increase Muscleblind-like expression and alleviate myotonic dystrophy phenotypes in mammalian models. Nat Commun 2018; 9:2482. [PMID: 29946070 PMCID: PMC6018771 DOI: 10.1038/s41467-018-04892-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 05/30/2018] [Indexed: 12/16/2022] Open
Abstract
Functional depletion of the alternative splicing factors Muscleblind-like (MBNL 1 and 2) is at the basis of the neuromuscular disease myotonic dystrophy type 1 (DM1). We previously showed the efficacy of miRNA downregulation in Drosophila DM1 model. Here, we screen for miRNAs that regulate MBNL1 and MBNL2 in HeLa cells. We thus identify miR-23b and miR-218, and confirm that they downregulate MBNL proteins in this cell line. Antagonists of miR-23b and miR-218 miRNAs enhance MBNL protein levels and rescue pathogenic missplicing events in DM1 myoblasts. Systemic delivery of these "antagomiRs" similarly boost MBNL expression and improve DM1-like phenotypes, including splicing alterations, histopathology, and myotonia in the HSALR DM1 model mice. These mammalian data provide evidence for therapeutic blocking of the miRNAs that control Muscleblind-like protein expression in myotonic dystrophy.
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Affiliation(s)
- Estefania Cerro-Herreros
- Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), University of Valencia, Dr. Moliner 50, E46100, Burjassot, Valencia, Spain.,Translational Genomics Group, Incliva Health Research Institute, Dr. Moliner 50, E46100, Burjassot, Valencia, Spain.,Joint Unit Incliva-CIPF, Dr. Moliner 50, E46100, Burjassot, Valencia, Spain
| | - Maria Sabater-Arcis
- Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), University of Valencia, Dr. Moliner 50, E46100, Burjassot, Valencia, Spain.,Translational Genomics Group, Incliva Health Research Institute, Dr. Moliner 50, E46100, Burjassot, Valencia, Spain.,Joint Unit Incliva-CIPF, Dr. Moliner 50, E46100, Burjassot, Valencia, Spain
| | - Juan M Fernandez-Costa
- Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), University of Valencia, Dr. Moliner 50, E46100, Burjassot, Valencia, Spain.,Translational Genomics Group, Incliva Health Research Institute, Dr. Moliner 50, E46100, Burjassot, Valencia, Spain.,Joint Unit Incliva-CIPF, Dr. Moliner 50, E46100, Burjassot, Valencia, Spain
| | - Nerea Moreno
- Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), University of Valencia, Dr. Moliner 50, E46100, Burjassot, Valencia, Spain.,Translational Genomics Group, Incliva Health Research Institute, Dr. Moliner 50, E46100, Burjassot, Valencia, Spain.,Joint Unit Incliva-CIPF, Dr. Moliner 50, E46100, Burjassot, Valencia, Spain
| | - Manuel Perez-Alonso
- Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), University of Valencia, Dr. Moliner 50, E46100, Burjassot, Valencia, Spain.,Translational Genomics Group, Incliva Health Research Institute, Dr. Moliner 50, E46100, Burjassot, Valencia, Spain.,Joint Unit Incliva-CIPF, Dr. Moliner 50, E46100, Burjassot, Valencia, Spain
| | - Beatriz Llamusi
- Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), University of Valencia, Dr. Moliner 50, E46100, Burjassot, Valencia, Spain. .,Translational Genomics Group, Incliva Health Research Institute, Dr. Moliner 50, E46100, Burjassot, Valencia, Spain. .,Joint Unit Incliva-CIPF, Dr. Moliner 50, E46100, Burjassot, Valencia, Spain.
| | - Ruben Artero
- Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), University of Valencia, Dr. Moliner 50, E46100, Burjassot, Valencia, Spain. .,Translational Genomics Group, Incliva Health Research Institute, Dr. Moliner 50, E46100, Burjassot, Valencia, Spain. .,Joint Unit Incliva-CIPF, Dr. Moliner 50, E46100, Burjassot, Valencia, Spain.
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8
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Thomas JD, Oliveira R, Sznajder ŁJ, Swanson MS. Myotonic Dystrophy and Developmental Regulation of RNA Processing. Compr Physiol 2018; 8:509-553. [PMID: 29687899 DOI: 10.1002/cphy.c170002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Myotonic dystrophy (DM) is a multisystemic disorder caused by microsatellite expansion mutations in two unrelated genes leading to similar, yet distinct, diseases. DM disease presentation is highly variable and distinguished by differences in age-of-onset and symptom severity. In the most severe form, DM presents with congenital onset and profound developmental defects. At the molecular level, DM pathogenesis is characterized by a toxic RNA gain-of-function mechanism that involves the transcription of noncoding microsatellite expansions. These mutant RNAs disrupt key cellular pathways, including RNA processing, localization, and translation. In DM, these toxic RNA effects are predominantly mediated through the modulation of the muscleblind-like and CUGBP and ETR-3-like factor families of RNA binding proteins (RBPs). Dysfunction of these RBPs results in widespread RNA processing defects culminating in the expression of developmentally inappropriate protein isoforms in adult tissues. The tissue that is the focus of this review, skeletal muscle, is particularly sensitive to mutant RNA-responsive perturbations, as patients display a variety of developmental, structural, and functional defects in muscle. Here, we provide a comprehensive overview of DM1 and DM2 clinical presentation and pathology as well as the underlying cellular and molecular defects associated with DM disease onset and progression. Additionally, fundamental aspects of skeletal muscle development altered in DM are highlighted together with ongoing and potential therapeutic avenues to treat this muscular dystrophy. © 2018 American Physiological Society. Compr Physiol 8:509-553, 2018.
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Affiliation(s)
- James D Thomas
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, Florida, USA
| | - Ruan Oliveira
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, Florida, USA
| | - Łukasz J Sznajder
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, Florida, USA
| | - Maurice S Swanson
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, Florida, USA
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9
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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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10
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Nakka K, Ghigna C, Gabellini D, Dilworth FJ. Diversification of the muscle proteome through alternative splicing. Skelet Muscle 2018; 8:8. [PMID: 29510724 PMCID: PMC5840707 DOI: 10.1186/s13395-018-0152-3] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 02/15/2018] [Indexed: 12/16/2022] Open
Abstract
Background Skeletal muscles express a highly specialized proteome that allows the metabolism of energy sources to mediate myofiber contraction. This muscle-specific proteome is partially derived through the muscle-specific transcription of a subset of genes. Surprisingly, RNA sequencing technologies have also revealed a significant role for muscle-specific alternative splicing in generating protein isoforms that give specialized function to the muscle proteome. Main body In this review, we discuss the current knowledge with respect to the mechanisms that allow pre-mRNA transcripts to undergo muscle-specific alternative splicing while identifying some of the key trans-acting splicing factors essential to the process. The importance of specific splicing events to specialized muscle function is presented along with examples in which dysregulated splicing contributes to myopathies. Though there is now an appreciation that alternative splicing is a major contributor to proteome diversification, the emergence of improved “targeted” proteomic methodologies for detection of specific protein isoforms will soon allow us to better appreciate the extent to which alternative splicing modifies the activity of proteins (and their ability to interact with other proteins) in the skeletal muscle. In addition, we highlight a continued need to better explore the signaling pathways that contribute to the temporal control of trans-acting splicing factor activity to ensure specific protein isoforms are expressed in the proper cellular context. Conclusions An understanding of the signal-dependent and signal-independent events driving muscle-specific alternative splicing has the potential to provide us with novel therapeutic strategies to treat different myopathies. Electronic supplementary material The online version of this article (10.1186/s13395-018-0152-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kiran Nakka
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada
| | - Claudia Ghigna
- Istituto di Genetica Molecolare-Consiglio Nazionale delle Ricerche (IGM-CNR), Pavia, Italy
| | - Davide Gabellini
- Unit of Gene Expression and Muscular Dystrophy, Division of Genetics and Cell Biology, IRCCS San Raffaele Scientific Institute, DIBIT2, 5A3-44, via Olgettina 58, 20132, Milan, Italy.
| | - F Jeffrey Dilworth
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada. .,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada. .,Sprott Centre for Stem Cell Research, Ottawa Hospital Research Institute, 501 Smyth Rd, Mailbox 511, Ottawa, ON, K1H 8L6, Canada.
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11
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Disturbed Ca 2+ Homeostasis in Muscle-Wasting Disorders. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1088:307-326. [PMID: 30390258 DOI: 10.1007/978-981-13-1435-3_14] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Ca2+ is essential for proper structure and function of skeletal muscle. It not only activates contraction and force development but also participates in multiple signaling pathways. Low levels of Ca2+ restrain muscle regeneration by limiting the fusion of satellite cells. Ironically, sustained elevations of Ca2+ also result in muscle degeneration as this ion promotes high rates of protein breakdown. Moreover, transforming growth factors (TGFs) which are well known for controlling muscle growth also regulate Ca2+ channels. Thus, therapies focused on changing levels of Ca2+ and TGFs are promising for treating muscle-wasting disorders. Three principal systems govern the homeostasis of Ca2+, namely, excitation-contraction (EC) coupling, excitation-coupled Ca2+ entry (ECCE), and store-operated Ca2+ entry (SOCE). Accordingly, alterations in these systems can lead to weakness and atrophy in many hereditary diseases, such as Brody disease, central core disease (CCD), tubular aggregate myopathy (TAM), myotonic dystrophy type 1 (MD1), oculopharyngeal muscular dystrophy (OPMD), and Duchenne muscular dystrophy (DMD). Here, the interrelationship between all these molecules and processes is reviewed.
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12
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Limpitikul W, Ong CS, Tomaselli GF. Neuromuscular Disease: Cardiac Manifestations and Sudden Death Risk. Card Electrophysiol Clin 2017; 9:731-747. [PMID: 29173414 DOI: 10.1016/j.ccep.2017.07.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Cardiovascular complications of neuromuscular diseases disproportionately affect the cardiac conduction system. Cardiomyopathy and cardiac arrhythmias produce significant morbidity and mortality. Patients with neuromuscular diseases should be carefully and frequently evaluated for the presence of bradycardia, heart block, and tachyarrhythmias. Preemptive treatment with permanent pacemakers or implanted defibrillators is appropriate in patients with conduction system disease or who are at risk for ventricular arrhythmias.
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Affiliation(s)
- Worawan Limpitikul
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Chin Siang Ong
- Department of Medicine, Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Gordon F Tomaselli
- Department of Medicine, Division of Cardiology, Johns Hopkins University School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA.
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13
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Provenzano C, Cappella M, Valaperta R, Cardani R, Meola G, Martelli F, Cardinali B, Falcone G. CRISPR/Cas9-Mediated Deletion of CTG Expansions Recovers Normal Phenotype in Myogenic Cells Derived from Myotonic Dystrophy 1 Patients. MOLECULAR THERAPY-NUCLEIC ACIDS 2017; 9:337-348. [PMID: 29246312 PMCID: PMC5684470 DOI: 10.1016/j.omtn.2017.10.006] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 10/11/2017] [Accepted: 10/11/2017] [Indexed: 02/05/2023]
Abstract
Myotonic dystrophy type 1 (DM1) is the most common adult-onset muscular dystrophy, characterized by progressive myopathy, myotonia, and multi-organ involvement. This dystrophy is an inherited autosomal dominant disease caused by a (CTG)n expansion within the 3′ untranslated region of the DMPK gene. Expression of the mutated gene results in production of toxic transcripts that aggregate as nuclear foci and sequester RNA-binding proteins, resulting in mis-splicing of several transcripts, defective translation, and microRNA dysregulation. No effective therapy is yet available for treatment of the disease. In this study, myogenic cell models were generated from myotonic dystrophy patient-derived fibroblasts. These cells exhibit typical disease-associated ribonuclear aggregates, containing CUG repeats and muscleblind-like 1 protein, and alternative splicing alterations. We exploited these cell models to develop new gene therapy strategies aimed at eliminating the toxic mutant repeats. Using the CRISPR/Cas9 gene-editing system, the repeat expansions were removed, therefore preventing nuclear foci formation and splicing alterations. Compared with the previously reported strategies of inhibition/degradation of CUG expanded transcripts by various techniques, the advantage of this approach is that affected cells can be permanently reverted to a normal phenotype.
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Affiliation(s)
- Claudia Provenzano
- Institute of Cell Biology and Neurobiology, National Research Council, Monterotondo, Rome, Italy
| | - Marisa Cappella
- Institute of Cell Biology and Neurobiology, National Research Council, Monterotondo, Rome, Italy; DAHFMO-Unit of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy
| | - Rea Valaperta
- Molecular Biology Laboratory, Policlinico San Donato-IRCCS, San Donato Milanese, Milan, Italy
| | - Rosanna Cardani
- Muscle Histopathology and Molecular Biology Laboratory, Policlinico San Donato-IRCCS, San Donato Milanese, Milan, Italy
| | - Giovanni Meola
- Department of Neurology, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy; Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| | - Fabio Martelli
- Molecular Cardiology Laboratory, Policlinico San Donato-IRCCS, San Donato Milanese, Milan, Italy
| | - Beatrice Cardinali
- Institute of Cell Biology and Neurobiology, National Research Council, Monterotondo, Rome, Italy.
| | - Germana Falcone
- Institute of Cell Biology and Neurobiology, National Research Council, Monterotondo, Rome, Italy.
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14
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Ravel-Chapuis A, Bélanger G, Côté J, Michel RN, Jasmin BJ. Misregulation of calcium-handling proteins promotes hyperactivation of calcineurin-NFAT signaling in skeletal muscle of DM1 mice. Hum Mol Genet 2017; 26:2192-2206. [PMID: 28369518 DOI: 10.1093/hmg/ddx109] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 03/16/2017] [Indexed: 12/26/2022] Open
Abstract
Myotonic Dystrophy type 1 (DM1) is caused by an expansion of CUG repeats in DMPK mRNAs. This mutation affects alternative splicing through misregulation of RNA-binding proteins. Amongst pre-mRNAs that are mis-spliced, several code for proteins involved in calcium homeostasis suggesting that calcium-handling and signaling are perturbed in DM1. Here, we analyzed expression of such proteins in DM1 mouse muscle. We found that the levels of several sarcoplasmic reticulum proteins (SERCA1, sarcolipin and calsequestrin) are altered, likely contributing to an imbalance in calcium homeostasis. We also observed that calcineurin (CnA) signaling is hyperactivated in DM1 muscle. Indeed, CnA expression and phosphatase activity are both markedly increased in DM1 muscle. Coherent with this, we found that activators of the CnA pathway (MLP, FHL1) are also elevated. Consequently, NFATc1 expression is increased in DM1 muscle and becomes relocalized to myonuclei, together with an up-regulation of its transcriptional targets (RCAN1.4 and myoglobin). Accordingly, DM1 mouse muscles display an increase in oxidative metabolism and fiber hypertrophy. To determine the functional consequences of this CnA hyperactivation, we administered cyclosporine A, an inhibitor of CnA, to DM1 mice. Muscles of treated DM1 mice showed an increase in CUGBP1 levels, and an exacerbation of key alternative splicing events associated with DM1. Finally, inhibition of CnA in cultured human DM1 myoblasts also resulted in a splicing exacerbation of the insulin receptor. Together, these findings show for the first time that calcium-CnA signaling is hyperactivated in DM1 muscle and that such hyperactivation represents a beneficial compensatory adaptation to the disease.
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Affiliation(s)
- Aymeric Ravel-Chapuis
- Department of Cellular and Molecular Medicine and Center for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Guy Bélanger
- Department of Cellular and Molecular Medicine and Center for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Jocelyn Côté
- Department of Cellular and Molecular Medicine and Center for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Robin N Michel
- Department of Exercise Science, Faculty of Arts and Science, Concordia University, Montreal, QC, Canada
| | - Bernard J Jasmin
- Department of Cellular and Molecular Medicine and Center for Neuromuscular Disease, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
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15
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Flucher BE, Tuluc P. How and why are calcium currents curtailed in the skeletal muscle voltage-gated calcium channels? J Physiol 2017; 595:1451-1463. [PMID: 27896815 PMCID: PMC5330888 DOI: 10.1113/jp273423] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 11/24/2016] [Indexed: 01/09/2023] Open
Abstract
Voltage‐gated calcium channels represent the sole mechanism converting electrical signals of excitable cells into cellular functions such as contraction, secretion and gene regulation. Specific voltage‐sensing domains detect changes in membrane potential and control channel gating. Calcium ions entering through the channel function as second messengers regulating cell functions, with the exception of skeletal muscle, where CaV1.1 essentially does not function as a channel but activates calcium release from intracellular stores. It has long been known that calcium currents are dispensable for skeletal muscle contraction. However, the questions as to how and why the channel function of CaV1.1 is curtailed remained obscure until the recent discovery of a developmental CaV1.1 splice variant with normal channel functions. This discovery provided new means to study the molecular mechanisms regulating the channel gating and led to the understanding that in skeletal muscle, calcium currents need to be restricted to allow proper regulation of fibre type specification and to prevent mitochondrial damage.
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Affiliation(s)
- Bernhard E Flucher
- Department of Physiology and Medical Physics, Medical University Innsbruck, Austria
| | - Petronel Tuluc
- Pharmacology and Toxicology, Institute of Pharmacy, University of Innsbruck, Austria
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16
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Piacentini R, Puma DDL, Mainardi M, Lazzarino G, Tavazzi B, Arancio O, Grassi C. Reduced gliotransmitter release from astrocytes mediates tau-induced synaptic dysfunction in cultured hippocampal neurons. Glia 2017; 65:1302-1316. [PMID: 28519902 PMCID: PMC5520670 DOI: 10.1002/glia.23163] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 04/13/2017] [Accepted: 04/18/2017] [Indexed: 01/19/2023]
Abstract
Tau is a microtubule-associated protein exerting several physiological functions in neurons. In Alzheimer's disease (AD) misfolded tau accumulates intraneuronally and leads to axonal degeneration. However, tau has also been found in the extracellular medium. Recent studies indicated that extracellular tau uploaded from neurons causes synaptic dysfunction and contributes to tau pathology propagation. Here we report novel evidence that extracellular tau oligomers are abundantly and rapidly accumulated in astrocytes where they disrupt intracellular Ca2+ signaling and Ca2+ -dependent release of gliotransmitters, especially ATP. Consequently, synaptic vesicle release, the expression of pre- and postsynaptic proteins, and mEPSC frequency and amplitude were reduced in neighboring neurons. Notably, we found that tau uploading from astrocytes required the amyloid precursor protein, APP. Collectively, our findings suggests that astrocytes play a critical role in the synaptotoxic effects of tau via reduced gliotransmitter availability, and that astrocytes are major determinants of tau pathology in AD.
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Affiliation(s)
- Roberto Piacentini
- Institute of Human Physiology, Medical School, Università Cattolica, Largo F. Vito 1, 00168, Rome, Italy
| | - Domenica Donatella Li Puma
- Institute of Human Physiology, Medical School, Università Cattolica, Largo F. Vito 1, 00168, Rome, Italy
| | - Marco Mainardi
- Institute of Human Physiology, Medical School, Università Cattolica, Largo F. Vito 1, 00168, Rome, Italy
| | - Giacomo Lazzarino
- Institute of Biochemistry and Clinical Biochemistry, Medical School, Università Cattolica, Largo F. Vito 1, 00168, Rome, Italy
| | - Barbara Tavazzi
- Institute of Biochemistry and Clinical Biochemistry, Medical School, Università Cattolica, Largo F. Vito 1, 00168, Rome, Italy
| | - Ottavio Arancio
- Department of Pathology and Cell Biology and Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, 630 W 168th St., NY 10032 USA
| | - Claudio Grassi
- Institute of Human Physiology, Medical School, Università Cattolica, Largo F. Vito 1, 00168, Rome, Italy
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17
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Shao D, Zhu X, Sun W, Huo L, Chen W, Wang H, Liu B, Pan P. Investigation of the molecular mechanisms underlying myotonic dystrophy types 1 and 2 cataracts using microRNA‑target gene networks. Mol Med Rep 2017; 16:3737-3744. [PMID: 28731161 PMCID: PMC5646950 DOI: 10.3892/mmr.2017.7059] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 02/23/2017] [Indexed: 01/03/2023] Open
Abstract
The purpose of the present study was to investigate the molecular mechanisms of myotonic dystrophy (DM) 1 and 2 cataracts using bioinformatics methods. A microarray dataset (E‑MEXP‑3365) downloaded from the Array Express database included lens epithelial samples of DM1 and DM2 cataract patients (n=3/group) and non‑DM lens epithelial samples as a control (n=4). Differentially expressed genes (DEGs) were identified between DM1 and control samples, and between DM2 and control samples. Pathway enrichment analyses were performed for the DEGs. Potential micro (mi)RNAs regulating these DEGs were predicted. An miRNA‑target gene network was constructed for DM1 and DM2. The study identified 223 DEGs in DM1, and 303 DEGs in DM2. DM1 and DM2 shared 172 DEGs. The DEGs in DM1 were enriched with calcium, Wnt and axon guidance signaling pathways. The DEGs in DM2 were linked by adherens junction signaling pathways. miRNA (miR)‑197, miR‑29b and miR‑29c were included in the network modules of DM1. miR‑197, miR‑29c and miR‑29a were involved in the network modules of DM2. It is therefore hypothesized that these signaling pathways and miRNAs underlie DM1 and DM2 cataracts, and may represent potential therapeutic targets for the treatment of this disorder.
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Affiliation(s)
- Dewang Shao
- Department of Ophthalmology, Air Force Aviation Medicine Research Institute Affiliated Hospital, Beijing 100089, P.R. China
| | - Xiaoquan Zhu
- Department of Ophthalmology, Air Force Aviation Medicine Research Institute Affiliated Hospital, Beijing 100089, P.R. China
| | - Wei Sun
- Department of Ophthalmology, Air Force Aviation Medicine Research Institute Affiliated Hospital, Beijing 100089, P.R. China
| | - Lu Huo
- Department of Ophthalmology, Air Force Aviation Medicine Research Institute Affiliated Hospital, Beijing 100089, P.R. China
| | - Wei Chen
- Department of Ophthalmology, Air Force General Hospital, Beijing 100089, P.R. China
| | - Hua Wang
- Department of Ophthalmology, Air Force General Hospital, Beijing 100089, P.R. China
| | - Bing Liu
- Department of Ophthalmology, Air Force General Hospital, Beijing 100089, P.R. China
| | - Peng Pan
- Department of Ophthalmology, Air Force Aviation Medicine Research Institute Affiliated Hospital, Beijing 100089, P.R. China
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18
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Seitter H, Koschak A. Relevance of tissue specific subunit expression in channelopathies. Neuropharmacology 2017; 132:58-70. [PMID: 28669898 DOI: 10.1016/j.neuropharm.2017.06.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 06/22/2017] [Accepted: 06/28/2017] [Indexed: 12/27/2022]
Abstract
Channelopathies are a diverse group of human disorders that are caused by mutations in genes coding for ion channels or channel-regulating proteins. Several dozen channelopathies have been identified that involve both non-excitable cells as well as electrically active tissues like brain, skeletal and smooth muscle or the heart. In this review, we start out from the general question which ion channel genes are expressed tissue-selectively. We mined the human gene expression database Human Protein Atlas (HPA) for tissue-enriched ion channel genes and found 85 genes belonging to the ion channel families. Most of these genes were enriched in brain, testis and muscle and a complete list of the enriched ion channel genes is provided. We further focused on the tissue distribution of voltage-gated calcium channel (VGCC) genes including different brain areas and the retina based on the human gene expression from the FANTOM5 dataset. The expression data is complemented by an overview of the tissue-dependent aspects of L-type calcium channel (LTCC) function, dysfunction and pharmacology, as well as of their splice variants. Finally, we focus on the pathology of tissue-restricted LTCC channelopathies and their treatment options. This article is part of the Special Issue entitled 'Channelopathies.'
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Affiliation(s)
- Hartwig Seitter
- University of Innsbruck, Institute of Pharmacy, Pharmacology and Toxicology, Center for Chemistry and Biomedicine, Innrain 80-82/III, 6020 Innsbruck, Austria
| | - Alexandra Koschak
- University of Innsbruck, Institute of Pharmacy, Pharmacology and Toxicology, Center for Chemistry and Biomedicine, Innrain 80-82/III, 6020 Innsbruck, Austria.
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19
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Brockhoff M, Rion N, Chojnowska K, Wiktorowicz T, Eickhorst C, Erne B, Frank S, Angelini C, Furling D, Rüegg MA, Sinnreich M, Castets P. Targeting deregulated AMPK/mTORC1 pathways improves muscle function in myotonic dystrophy type I. J Clin Invest 2017; 127:549-563. [PMID: 28067669 DOI: 10.1172/jci89616] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 11/17/2016] [Indexed: 12/13/2022] Open
Abstract
Myotonic dystrophy type I (DM1) is a disabling multisystemic disease that predominantly affects skeletal muscle. It is caused by expanded CTG repeats in the 3'-UTR of the dystrophia myotonica protein kinase (DMPK) gene. RNA hairpins formed by elongated DMPK transcripts sequester RNA-binding proteins, leading to mis-splicing of numerous pre-mRNAs. Here, we have investigated whether DM1-associated muscle pathology is related to deregulation of central metabolic pathways, which may identify potential therapeutic targets for the disease. In a well-characterized mouse model for DM1 (HSALR mice), activation of AMPK signaling in muscle was impaired under starved conditions, while mTORC1 signaling remained active. In parallel, autophagic flux was perturbed in HSALR muscle and in cultured human DM1 myotubes. Pharmacological approaches targeting AMPK/mTORC1 signaling greatly ameliorated muscle function in HSALR mice. AICAR, an AMPK activator, led to a strong reduction of myotonia, which was accompanied by partial correction of misregulated alternative splicing. Rapamycin, an mTORC1 inhibitor, improved muscle relaxation and increased muscle force in HSALR mice without affecting splicing. These findings highlight the involvement of AMPK/mTORC1 deregulation in DM1 muscle pathophysiology and may open potential avenues for the treatment of this disease.
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20
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Tajhya RB, Hu X, Tanner MR, Huq R, Kongchan N, Neilson JR, Rodney GG, Horrigan FT, Timchenko LT, Beeton C. Functional KCa1.1 channels are crucial for regulating the proliferation, migration and differentiation of human primary skeletal myoblasts. Cell Death Dis 2016; 7:e2426. [PMID: 27763639 PMCID: PMC5133989 DOI: 10.1038/cddis.2016.324] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 09/14/2016] [Accepted: 09/15/2016] [Indexed: 01/14/2023]
Abstract
Myoblasts are mononucleated precursors of myofibers; they persist in mature skeletal muscles for growth and regeneration post injury. During myotonic dystrophy type 1 (DM1), a complex autosomal-dominant neuromuscular disease, the differentiation of skeletal myoblasts into functional myotubes is impaired, resulting in muscle wasting and weakness. The mechanisms leading to this altered differentiation are not fully understood. Here, we demonstrate that the calcium- and voltage-dependent potassium channel, KCa1.1 (BK, Slo1, KCNMA1), regulates myoblast proliferation, migration, and fusion. We also show a loss of plasma membrane expression of the pore-forming α subunit of KCa1.1 in DM1 myoblasts. Inhibiting the function of KCa1.1 in healthy myoblasts induced an increase in cytosolic calcium levels and altered nuclear factor kappa B (NFκB) levels without affecting cell survival. In these normal cells, KCa1.1 block resulted in enhanced proliferation and decreased matrix metalloproteinase secretion, migration, and myotube fusion, phenotypes all observed in DM1 myoblasts and associated with disease pathogenesis. In contrast, introducing functional KCa1.1 α-subunits into DM1 myoblasts normalized their proliferation and rescued expression of the late myogenic marker Mef2. Our results identify KCa1.1 channels as crucial regulators of skeletal myogenesis and suggest these channels as novel therapeutic targets in DM1.
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Affiliation(s)
- Rajeev B Tajhya
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA.,Graduate Program in Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA.,Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
| | - Xueyou Hu
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Mark R Tanner
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA.,Interdepartmental Graduate Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Redwan Huq
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA.,Graduate Program in Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Natee Kongchan
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Joel R Neilson
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA.,Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
| | - George G Rodney
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA.,Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
| | - Frank T Horrigan
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA.,Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA.,Center for Drug Discovery, Baylor College of Medicine, Houston, TX 77030, USA
| | - Lubov T Timchenko
- Department of Pediatrics Neurology, Cincinnati Children's Hospital, Cincinnati, OH 45219, USA
| | - Christine Beeton
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA.,Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA.,Center for Drug Discovery, Baylor College of Medicine, Houston, TX 77030, USA.,Biology of Inflammation Center, Baylor College of Medicine, Houston, TX 77030, USA
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21
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Tuluc P, Benedetti B, Coste de Bagneaux P, Grabner M, Flucher BE. Two distinct voltage-sensing domains control voltage sensitivity and kinetics of current activation in CaV1.1 calcium channels. J Gen Physiol 2016; 147:437-49. [PMID: 27185857 PMCID: PMC4886277 DOI: 10.1085/jgp.201611568] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 04/18/2016] [Indexed: 01/25/2023] Open
Abstract
Alternative splicing of the skeletal muscle CaV1.1 voltage-gated calcium channel gives rise to two channel variants with very different gating properties. The currents of both channels activate slowly; however, insertion of exon 29 in the adult splice variant CaV1.1a causes an ∼30-mV right shift in the voltage dependence of activation. Existing evidence suggests that the S3-S4 linker in repeat IV (containing exon 29) regulates voltage sensitivity in this voltage-sensing domain (VSD) by modulating interactions between the adjacent transmembrane segments IVS3 and IVS4. However, activation kinetics are thought to be determined by corresponding structures in repeat I. Here, we use patch-clamp analysis of dysgenic (CaV1.1 null) myotubes reconstituted with CaV1.1 mutants and chimeras to identify the specific roles of these regions in regulating channel gating properties. Using site-directed mutagenesis, we demonstrate that the structure and/or hydrophobicity of the IVS3-S4 linker is critical for regulating voltage sensitivity in the IV VSD, but by itself cannot modulate voltage sensitivity in the I VSD. Swapping sequence domains between the I and the IV VSDs reveals that IVS4 plus the IVS3-S4 linker is sufficient to confer CaV1.1a-like voltage dependence to the I VSD and that the IS3-S4 linker plus IS4 is sufficient to transfer CaV1.1e-like voltage dependence to the IV VSD. Any mismatch of transmembrane helices S3 and S4 from the I and IV VSDs causes a right shift of voltage sensitivity, indicating that regulation of voltage sensitivity by the IVS3-S4 linker requires specific interaction of IVS4 with its corresponding IVS3 segment. In contrast, slow current kinetics are perturbed by any heterologous sequences inserted into the I VSD and cannot be transferred by moving VSD I sequences to VSD IV. Thus, CaV1.1 calcium channels are organized in a modular manner, and control of voltage sensitivity and activation kinetics is accomplished by specific molecular mechanisms within the IV and I VSDs, respectively.
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Affiliation(s)
- Petronel Tuluc
- Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Innsbruck, A-6020 Innsbruck, Austria
| | - Bruno Benedetti
- Department of Physiology and Medical Physics, Medical University Innsbruck, A-6020 Innsbruck, Austria
| | - Pierre Coste de Bagneaux
- Department of Physiology and Medical Physics, Medical University Innsbruck, A-6020 Innsbruck, Austria
| | - Manfred Grabner
- Department of Medical Genetics, Molecular and Clinical Pharmacology, Medical University Innsbruck, A-6020 Innsbruck, Austria
| | - Bernhard E Flucher
- Department of Physiology and Medical Physics, Medical University Innsbruck, A-6020 Innsbruck, Austria
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22
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Guglielmi V, Oosterhof A, Voermans NC, Cardani R, Molenaar JP, van Kuppevelt TH, Meola G, van Engelen BG, Tomelleri G, Vattemi G. Characterization of sarcoplasmic reticulum Ca(2+) ATPase pumps in muscle of patients with myotonic dystrophy and with hypothyroid myopathy. Neuromuscul Disord 2016; 26:378-85. [PMID: 27133661 DOI: 10.1016/j.nmd.2016.04.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 03/31/2016] [Accepted: 04/01/2016] [Indexed: 10/22/2022]
Abstract
Sarcoplasmic/endoplasmic reticulum Ca(2+) ATPase (SERCA) pumps play the major role in lowering cytoplasmic calcium concentration in skeletal muscle by catalyzing the ATP-dependent transport of Ca(2+) from the cytosol to the lumen of the sarcoplasmic reticulum (SR). Although SERCA abnormalities have been hypothesized to contribute to the dysregulation of intracellular Ca(2+) homeostasis and signaling in muscle of patients with myotonic dystrophy (DM) and hypothyroid myopathy, the characterization of SERCA pumps remains elusive and their impairment is still unclear. We assessed the activity of SR Ca(2+)-ATPase, expression levels and fiber distribution of SERCA1 and SERCA2, and oligomerization of SERCA1 protein in muscle of patients with DM type 1 and 2, and with hypothyroid myopathy. Our data provide evidence that SR Ca(2+) ATPase activity, protein levels and muscle fiber distribution of total SERCA1 and SERCA2, and SERCA1 oligomerization pattern are similar in patients with both DM1 and DM2, hypothyroid myopathy and in control subjects. We prove that SERCA1b, the neonatal isoform of SERCA1, is expressed at protein level in muscle of patients with DM2 and, in lower amount, of patients with DM1. Our present study demonstrates that SERCA function is not altered in muscle of patients with DM and with hypothyroid myopathy.
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Affiliation(s)
- V Guglielmi
- Department of Neurological and Movement Sciences, Section of Clinical Neurology, University of Verona, Italy
| | - A Oosterhof
- Department of Biochemistry, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - N C Voermans
- Neuromuscular Centre Nijmegen, Department of Neurology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - R Cardani
- Department of Biomedical Sciences for Health, IRCCS Policlinico San Donato, University of Milan, Italy
| | - J P Molenaar
- Neuromuscular Centre Nijmegen, Department of Neurology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - T H van Kuppevelt
- Department of Biochemistry, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - G Meola
- Department of Biomedical Sciences for Health, IRCCS Policlinico San Donato, University of Milan, Italy
| | - B G van Engelen
- Neuromuscular Centre Nijmegen, Department of Neurology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - G Tomelleri
- Department of Neurological and Movement Sciences, Section of Clinical Neurology, University of Verona, Italy
| | - G Vattemi
- Department of Neurological and Movement Sciences, Section of Clinical Neurology, University of Verona, Italy.
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Sultana N, Dienes B, Benedetti A, Tuluc P, Szentesi P, Sztretye M, Rainer J, Hess MW, Schwarzer C, Obermair GJ, Csernoch L, Flucher BE. Restricting calcium currents is required for correct fiber type specification in skeletal muscle. Development 2016; 143:1547-59. [PMID: 26965373 PMCID: PMC4909858 DOI: 10.1242/dev.129676] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 02/29/2016] [Indexed: 11/20/2022]
Abstract
Skeletal muscle excitation-contraction (EC) coupling is independent of calcium influx. In fact, alternative splicing of the voltage-gated calcium channel CaV1.1 actively suppresses calcium currents in mature muscle. Whether this is necessary for normal development and function of muscle is not known. However, splicing defects that cause aberrant expression of the calcium-conducting developmental CaV1.1e splice variant correlate with muscle weakness in myotonic dystrophy. Here, we deleted CaV1.1 (Cacna1s) exon 29 in mice. These mice displayed normal overall motor performance, although grip force and voluntary running were reduced. Continued expression of the developmental CaV1.1e splice variant in adult mice caused increased calcium influx during EC coupling, altered calcium homeostasis, and spontaneous calcium sparklets in isolated muscle fibers. Contractile force was reduced and endurance enhanced. Key regulators of fiber type specification were dysregulated and the fiber type composition was shifted toward slower fibers. However, oxidative enzyme activity and mitochondrial content declined. These findings indicate that limiting calcium influx during skeletal muscle EC coupling is important for the secondary function of the calcium signal in the activity-dependent regulation of fiber type composition and to prevent muscle disease.
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Affiliation(s)
- Nasreen Sultana
- Department of Physiology and Medical Physics, Medical University Innsbruck, Innsbruck 6020, Austria
| | - Beatrix Dienes
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen 4032, Hungary
| | - Ariane Benedetti
- Department of Physiology and Medical Physics, Medical University Innsbruck, Innsbruck 6020, Austria
| | - Petronel Tuluc
- Department of Pharmacology, University of Innsbruck, Innsbruck 6020, Austria
| | - Peter Szentesi
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen 4032, Hungary
| | - Monika Sztretye
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen 4032, Hungary
| | - Johannes Rainer
- Division of Molecular Pathophysiology, Biocenter, Medical University Innsbruck, Innsbruck 6020, Austria
| | - Michael W Hess
- Division of Histology and Embryology, Medical University Innsbruck, Innsbruck 6020, Austria
| | - Christoph Schwarzer
- Department of Pharmacology, Medical University Innsbruck, Innsbruck 6020, Austria
| | - Gerald J Obermair
- Department of Physiology and Medical Physics, Medical University Innsbruck, Innsbruck 6020, Austria
| | - Laszlo Csernoch
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen 4032, Hungary
| | - Bernhard E Flucher
- Department of Physiology and Medical Physics, Medical University Innsbruck, Innsbruck 6020, Austria
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24
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Benedetti B, Tuluc P, Mastrolia V, Dlaska C, Flucher BE. Physiological and pharmacological modulation of the embryonic skeletal muscle calcium channel splice variant CaV1.1e. Biophys J 2016; 108:1072-80. [PMID: 25762319 PMCID: PMC4375451 DOI: 10.1016/j.bpj.2015.01.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 01/13/2015] [Accepted: 01/28/2015] [Indexed: 01/05/2023] Open
Abstract
CaV1.1e is the voltage-gated calcium channel splice variant of embryonic skeletal muscle. It differs from the adult CaV1.1a splice variant by the exclusion of exon 29 coding for 19 amino acids in the extracellular loop connecting transmembrane domains IVS3 and IVS4. Like the adult splice variant CaV1.1a, the embryonic CaV1.1e variant functions as voltage sensor in excitation-contraction coupling, but unlike CaV1.1a it also conducts sizable calcium currents. Consequently, physiological or pharmacological modulation of calcium currents may have a greater impact in CaV1.1e expressing muscle cells. Here, we analyzed the effects of L-type current modulators on whole-cell current properties in dysgenic (CaV1.1-null) myotubes reconstituted with either CaV1.1a or CaV1.1e. Furthermore, we examined the physiological current modulation by interactions with the ryanodine receptor using a chimeric CaV1.1e construct in which the cytoplasmic II-III loop, essential for skeletal muscle excitation-contraction coupling, has been replaced with the corresponding but nonfunctional loop from the Musca channel. Whereas the equivalent substitution in CaV1.1a had abolished the calcium currents, substitution of the II-III loop in CaV1.1e did not significantly reduce current amplitudes. This indicates that CaV1.1e is not subject to retrograde coupling with the ryanodine receptor and that the retrograde coupling mechanism in CaV1.1a operates by counteracting the limiting effects of exon 29 inclusion on the current amplitude. Pharmacologically, CaV1.1e behaves like other L-type calcium channels. Its currents are substantially increased by the calcium channel agonist Bay K 8644 and inhibited by the calcium channel blocker nifedipine in a dose-dependent manner. With an IC50 of 0.37 μM for current inhibition by nifedipine, CaV1.1e is a potential drug target for the treatment of myotonic dystrophy. It might block the excessive calcium influx resulting from the aberrant expression of the embryonic splice variant CaV1.1e in the skeletal muscles of myotonic dystrophy patients.
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MESH Headings
- 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/pharmacology
- Animals
- Calcium/metabolism
- Calcium Channel Blockers/pharmacology
- Calcium Channels, L-Type/drug effects
- Calcium Channels, L-Type/genetics
- Calcium Channels, L-Type/metabolism
- Cell Line, Tumor
- Excitation Contraction Coupling
- Muscle Fibers, Skeletal/drug effects
- Muscle Fibers, Skeletal/metabolism
- Muscle Fibers, Skeletal/physiology
- Nifedipine/pharmacology
- Protein Isoforms/drug effects
- Protein Isoforms/genetics
- Protein Isoforms/metabolism
- Rats
- Ryanodine Receptor Calcium Release Channel/metabolism
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Affiliation(s)
- Bruno Benedetti
- Department of Physiology and Medical Physics, Medical University Innsbruck, Innsbruck, Austria
| | - Petronel Tuluc
- Department of Physiology and Medical Physics, Medical University Innsbruck, Innsbruck, Austria; Pharmacology and Toxicology, Institute of Pharmacy, University of Innsbruck, Innsbruck, Austria
| | - Vincenzo Mastrolia
- Department of Physiology and Medical Physics, Medical University Innsbruck, Innsbruck, Austria
| | - Clemens Dlaska
- Department of Physiology and Medical Physics, Medical University Innsbruck, Innsbruck, Austria
| | - Bernhard E Flucher
- Department of Physiology and Medical Physics, Medical University Innsbruck, Innsbruck, Austria.
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25
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Functional analysis of SERCA1b, a highly expressed SERCA1 variant in myotonic dystrophy type 1 muscle. Biochim Biophys Acta Mol Basis Dis 2015; 1852:2042-7. [DOI: 10.1016/j.bbadis.2015.07.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Revised: 06/23/2015] [Accepted: 07/06/2015] [Indexed: 01/17/2023]
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26
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Zamponi GW, Striessnig J, Koschak A, Dolphin AC. The Physiology, Pathology, and Pharmacology of Voltage-Gated Calcium Channels and Their Future Therapeutic Potential. Pharmacol Rev 2015; 67:821-70. [PMID: 26362469 PMCID: PMC4630564 DOI: 10.1124/pr.114.009654] [Citation(s) in RCA: 704] [Impact Index Per Article: 78.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Voltage-gated calcium channels are required for many key functions in the body. In this review, the different subtypes of voltage-gated calcium channels are described and their physiologic roles and pharmacology are outlined. We describe the current uses of drugs interacting with the different calcium channel subtypes and subunits, as well as specific areas in which there is strong potential for future drug development. Current therapeutic agents include drugs targeting L-type Ca(V)1.2 calcium channels, particularly 1,4-dihydropyridines, which are widely used in the treatment of hypertension. T-type (Ca(V)3) channels are a target of ethosuximide, widely used in absence epilepsy. The auxiliary subunit α2δ-1 is the therapeutic target of the gabapentinoid drugs, which are of value in certain epilepsies and chronic neuropathic pain. The limited use of intrathecal ziconotide, a peptide blocker of N-type (Ca(V)2.2) calcium channels, as a treatment of intractable pain, gives an indication that these channels represent excellent drug targets for various pain conditions. We describe how selectivity for different subtypes of calcium channels (e.g., Ca(V)1.2 and Ca(V)1.3 L-type channels) may be achieved in the future by exploiting differences between channel isoforms in terms of sequence and biophysical properties, variation in splicing in different target tissues, and differences in the properties of the target tissues themselves in terms of membrane potential or firing frequency. Thus, use-dependent blockers of the different isoforms could selectively block calcium channels in particular pathologies, such as nociceptive neurons in pain states or in epileptic brain circuits. Of important future potential are selective Ca(V)1.3 blockers for neuropsychiatric diseases, neuroprotection in Parkinson's disease, and resistant hypertension. In addition, selective or nonselective T-type channel blockers are considered potential therapeutic targets in epilepsy, pain, obesity, sleep, and anxiety. Use-dependent N-type calcium channel blockers are likely to be of therapeutic use in chronic pain conditions. Thus, more selective calcium channel blockers hold promise for therapeutic intervention.
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Affiliation(s)
- Gerald W Zamponi
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada (G.W.Z.); Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck, Innsbruck, Austria (J.S., A.K.); and Department of Neuroscience, Physiology, and Pharmacology, Division of Biosciences, University College London, London, United Kingdom (A.C.D.)
| | - Joerg Striessnig
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada (G.W.Z.); Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck, Innsbruck, Austria (J.S., A.K.); and Department of Neuroscience, Physiology, and Pharmacology, Division of Biosciences, University College London, London, United Kingdom (A.C.D.)
| | - Alexandra Koschak
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada (G.W.Z.); Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck, Innsbruck, Austria (J.S., A.K.); and Department of Neuroscience, Physiology, and Pharmacology, Division of Biosciences, University College London, London, United Kingdom (A.C.D.)
| | - Annette C Dolphin
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada (G.W.Z.); Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck, Innsbruck, Austria (J.S., A.K.); and Department of Neuroscience, Physiology, and Pharmacology, Division of Biosciences, University College London, London, United Kingdom (A.C.D.)
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27
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Kósa M, Brinyiczki K, van Damme P, Goemans N, Hancsák K, Mendler L, Zádor E. The neonatal sarcoplasmic reticulum Ca2+-ATPase gives a clue to development and pathology in human muscles. J Muscle Res Cell Motil 2014; 36:195-203. [PMID: 25487304 DOI: 10.1007/s10974-014-9403-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 12/03/2014] [Indexed: 01/07/2023]
Abstract
The sarcoplasmic/endoplasmic reticulum calcium ATPase 1 (SERCA1) has two muscle specific splice isoforms; SERCA1a in fast-type adult and SERCA1b in neonatal and regenerating skeletal muscles. At the protein level the only difference between these two isoforms is that SERCA1a has C-terminal glycine while SERCA1b has an octapeptide tail instead. This makes the generation of a SERCA1a specific antibody not feasible. The switch between the two isoforms is a hallmark of differentiation so we describe here a method based on the signal ratios of the SERCA1b specific and pan SERCA1 antibodies to estimate the SERCA1b/SERCA1a dominance on immunoblot of human muscles. Using this method we showed that unlike in mouse and rat, SERCA1b was only expressed in pre-matured infant leg and arm muscles; it was replaced by SERCA1a in more matured neonatal muscles and was completely absent in human foetal and neonatal diaphragms. Interestingly, only SERCA1a and no SERCA1b were detected in muscles of 7-12 years old boys with Duchenne, a degenerative-regenerative muscular dystrophy. However, in adult patients with myotonic dystrophy type 2 (DM2), the SERCA1b dominated over SERCA1a. Thus the human SERCA1b has a different expression pattern from that of rodents and it is associated with DM2.
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Affiliation(s)
- Magdolna Kósa
- Department of Biochemistry, Faculty of General Medicine, University of Szeged, Dóm tér 9, H-6720, Szeged, Hungary
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28
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Abstract
Muscular dystrophies are a group of diseases characterised by the primary wasting of skeletal muscle, which compromises patient mobility and in the most severe cases originate a complete paralysis and premature death. Existing evidence implicates calcium dysregulation as an underlying crucial event in the pathophysiology of several muscular dystrophies, such as dystrophinopathies, calpainopathies or myotonic dystrophy among others. Duchenne muscular dystrophy is the most frequent myopathy in childhood, and calpainopathy or LGMD2A is the most common form of limb-girdle muscular dystrophy, whereas myotonic dystrophy is the most frequent inherited muscle disease worldwide. In this review, we summarise recent advances in our understanding of calcium ion cycling through the sarcolemma, the sarcoplasmic reticulum and mitochondria, and its involvement in the pathogenesis of these dystrophies. We also discuss some of the clinical implications of recent findings regarding Ca2+ handling as well as novel approaches to treat muscular dystrophies targeting Ca2+ regulatory proteins.
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29
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30
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Kosiorek M, Podszywalow-Bartnicka P, Zylinska L, Pikula S. NFAT1 and NFAT3 cooperate with HDAC4 during regulation of alternative splicing of PMCA isoforms in PC12 cells. PLoS One 2014; 9:e99118. [PMID: 24905014 PMCID: PMC4048221 DOI: 10.1371/journal.pone.0099118] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 05/10/2014] [Indexed: 02/07/2023] Open
Abstract
Background The bulk of human genes undergo alternative splicing (AS) upon response to physiological stimuli. AS is a great source of protein diversity and biological processes and is associated with the development of many diseases. Pheochromocytoma is a neuroendocrine tumor, characterized by an excessive Ca2+-dependent secretion of catecholamines. This underlines the importance of balanced control of calcium transport via regulation of gene expression pattern, including different calcium transport systems, such as plasma membrane Ca2+-ATPases (PMCAs), abundantly expressed in pheochromocytoma chromaffin cells (PC12 cells). PMCAs are encoded by four genes (Atp2b1, Atp2b2, Atp2b3, Atp2b4), whose transcript products undergo alternative splicing giving almost 30 variants. Results In this scientific report, we propose a novel mechanism of regulation of PMCA alternative splicing in PC12 cells through cooperation of the nuclear factor of activated T-cells (NFAT) and histone deacetylases (HDACs). Luciferase assays showed increased activity of NFAT in PC12 cells, which was associated with altered expression of PMCA. RT-PCR experiments suggested that inhibition of the transcriptional activity of NFAT might result in the rearrangement of PMCA splicing variants in PC12 cells. NFAT inhibition led to dominant expression of 2x/c, 3x/a and 4x/a PMCA variants, while in untreated cells the 2w,z/b, 3z,x/b,c,e,f, and 4x/b variants were found as well. Furthermore, chromatin immunoprecipitation experiments showed that NFAT1-HDAC4 or NFAT3-HDAC4 complexes might be involved in regulation of PMCA2x splicing variant generation. Conclusions We suggest that the influence of NFAT/HDAC on PMCA isoform composition might be important for altered dopamine secretion by PC12 cells.
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Affiliation(s)
- Michalina Kosiorek
- Department of Biochemistry, Nencki Institute of Experimental Biology, Warsaw, Poland
- Department of Neurodegenerative Disorders, Laboratory of Neurogenetics, Mossakowski Medical Research Centre PAS, Warsaw, Poland
| | | | - Ludmila Zylinska
- Department of Molecular Neurochemistry, Medical University, Lodz, Poland
| | - Slawomir Pikula
- Department of Biochemistry, Nencki Institute of Experimental Biology, Warsaw, Poland
- * E-mail:
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31
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Podda MV, Leone L, Barbati SA, Mastrodonato A, Li Puma DD, Piacentini R, Grassi C. Extremely low-frequency electromagnetic fields enhance the survival of newborn neurons in the mouse hippocampus. Eur J Neurosci 2013; 39:893-903. [DOI: 10.1111/ejn.12465] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 11/26/2013] [Accepted: 11/28/2013] [Indexed: 01/12/2023]
Affiliation(s)
- Maria V. Podda
- Institute of Human Physiology; Medical School; Università Cattolica del Sacro Cuore; Largo Francesco Vito 1 00168 Rome Italy
| | - Lucia Leone
- Institute of Human Physiology; Medical School; Università Cattolica del Sacro Cuore; Largo Francesco Vito 1 00168 Rome Italy
| | - Saviana A. Barbati
- Institute of Human Physiology; Medical School; Università Cattolica del Sacro Cuore; Largo Francesco Vito 1 00168 Rome Italy
| | - Alessia Mastrodonato
- Institute of Human Physiology; Medical School; Università Cattolica del Sacro Cuore; Largo Francesco Vito 1 00168 Rome Italy
| | - Domenica D. Li Puma
- Institute of Human Physiology; Medical School; Università Cattolica del Sacro Cuore; Largo Francesco Vito 1 00168 Rome Italy
| | - Roberto Piacentini
- Institute of Human Physiology; Medical School; Università Cattolica del Sacro Cuore; Largo Francesco Vito 1 00168 Rome Italy
| | - Claudio Grassi
- Institute of Human Physiology; Medical School; Università Cattolica del Sacro Cuore; Largo Francesco Vito 1 00168 Rome Italy
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32
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Podda MV, Grassi C. New perspectives in cyclic nucleotide-mediated functions in the CNS: the emerging role of cyclic nucleotide-gated (CNG) channels. Pflugers Arch 2013; 466:1241-57. [PMID: 24142069 DOI: 10.1007/s00424-013-1373-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2013] [Revised: 09/27/2013] [Accepted: 09/28/2013] [Indexed: 01/07/2023]
Abstract
Cyclic nucleotides play fundamental roles in the central nervous system (CNS) under both physiological and pathological conditions. The impact of cAMP and cGMP signaling on neuronal and glial cell functions has been thoroughly characterized. Most of their effects have been related to cyclic nucleotide-dependent protein kinase activity. However, cyclic nucleotide-gated (CNG) channels, first described as key mediators of sensory transduction in retinal and olfactory receptors, have been receiving increasing attention as possible targets of cyclic nucleotides in the CNS. In the last 15 years, consistent evidence has emerged for their expression in neurons and astrocytes of the rodent brain. Far less is known, however, about the functional role of CNG channels in these cells, although several of their features, such as Ca(2+) permeability and prolonged activation in the presence of cyclic nucleotides, make them ideal candidates for mediators of physiological functions in the CNS. Here, we review literature suggesting the involvement of CNG channels in a number of CNS cellular functions (e.g., regulation of membrane potential, neuronal excitability, and neurotransmitter release) as well as in more complex phenomena, like brain plasticity, adult neurogenesis, and pain sensitivity. The emerging picture is that functional and dysfunctional cyclic nucleotide signaling in the CNS has to be reconsidered including CNG channels among possible targets. However, concerted efforts and multidisciplinary approaches are still needed to get more in-depth knowledge in this field.
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Affiliation(s)
- Maria Vittoria Podda
- Institute of Human Physiology, Medical School, Università Cattolica, Largo Francesco Vito 1, 00168, Rome, Italy
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