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Bai Y, Ding X, Liu Z, Shen J, Huang Y. Identification and functional analysis of circRNAs in the skeletal muscle of juvenile and adult largemouth bass (Micropterus salmoides). COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART D, GENOMICS & PROTEOMICS 2022; 42:100969. [PMID: 35150971 DOI: 10.1016/j.cbd.2022.100969] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 01/06/2022] [Accepted: 01/28/2022] [Indexed: 12/13/2022]
Abstract
Circular RNA (circRNA) is a novel emerging type of endogenous regulatory non-coding RNA molecules with a covalent closed-loop configuration, which exerts important functions in multiple biological processes. CircRNAs are known to regulate gene expression as functional regulators interacting with miRNAs by sponge, which have been reported to regulate skeletal muscle development. Nevertheless, the information of circRNAs involved in regulating muscle growth and development in fish is largely unknown. Here, we first identified 312 and 511 circRNAs in skeletal muscle of juvenile and adult largemouth bass (LMB) using RNA sequencing, respectively. The differentially expressed circRNAs (DE-circRNAs) analysis showed that there are 44 DE-circRNAs at two different skeletal muscle growth stages. Six circRNAs were chosen randomly and their relative expression levels in juvenile and adult LMB were confirmed by real-time PCR, indicating that these circRNAs were existed authenticity. In addition, Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analysis showed that these hose genes (their linear mRNAs) of DE-circRNAs were mainly enriched in the regulation of actin cytoskeleton signaling pathways. The circRNA-miRNA interaction regulatory networks indicated that one circRNA can regulate one or more miRNA. For instance, more than 30 miRNAs were regulated by two circRNAs (circRNA389 and circRNA399). Of them, the muscle-related miRNAs including the let-7 family, miR-133 and miR-26 and so on were found acting as miRNAs sponge regulated by circRNAs, indicating the roles of circRNAs in regulating muscle growth-related genes expression. Overall, these findings will not only broaden our understanding of circRNAs regulation mechanisms underlying muscle growth and development in LMB but also provides a novel clue for further functional research in carnivorous fish genetic breeding.
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Affiliation(s)
- Yuhe Bai
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471023, China
| | - Xinyu Ding
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471023, China
| | - Zezhong Liu
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471023, China
| | - Junfei Shen
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471023, China
| | - Yong Huang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471023, China.
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2
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Hu Z, Cao J, Zhang J, Ge L, Zhang H, Liu X. Skeletal Muscle Transcriptome Analysis of Hanzhong Ma Duck at Different Growth Stages Using RNA-Seq. Biomolecules 2021; 11:315. [PMID: 33669581 PMCID: PMC7927120 DOI: 10.3390/biom11020315] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 02/12/2021] [Accepted: 02/14/2021] [Indexed: 01/02/2023] Open
Abstract
As one of the most important poultry worldwide, ducks (Anas platyrhynchos) are raised mainly for meat and egg products, and muscle development in ducks is important for meat production. Therefore, an investigation of gene expression in duck skeletal muscle would significantly contribute to our understanding of muscle development. In this study, twenty-four cDNA libraries were constructed from breast and leg muscles of Hanzhong Ma ducks at day 17, 21, 27 of the embryo and postnatal at 6-month-old. High-throughput sequencing and bioinformatics were used to determine the abundances and characteristics of transcripts. A total of 632,172,628 (average 52,681,052) and 637,213,938 (average 53,101,162) reads were obtained from the sequencing data of breast and leg muscles, respectively. Over 71.63% and 77.36% of the reads could be mapped to the Anas platyrhynchos genome. In the skeletal muscle of Hanzhong duck, intron variant (INTRON), synonymous variant (SYNONYMOUS_CODING), and prime 3' UTR variant (UTR_3_PRIME) were the main single nucleotide polymorphisms (SNP) annotation information, and "INTRON", "UTR_3_PRIME", and downstream-gene variant (DOWNSTREAM) were the main insertion-deletion (InDel) annotation information. The predicted number of alternative splicing (AS) in all samples were mainly alternative 5' first exon (transcription start site)-the first exon splicing (TSS) and alternative 3' last exon (transcription terminal site)-the last exon splicing (TTS). Besides, there were 292 to 2801 annotated differentially expressed genes (DEGs) in breast muscle and 304 to 1950 annotated DEGs in leg muscle from different databases. It is worth noting that 75 DEGs in breast muscle and 49 DEGs in leg muscle were co-expressed at all developmental points of comparison, respectively. The RNA-Seq data were confirmed to be reliable by qPCR. The identified DEGs, such as CREBL2, RHEB, GDF6, SHISA2, MYLK2, ACTN3, RYR3, and STMN1, were specially highlighted, indicating their strong associations with muscle development in the Hanzhong Ma duck. KEGG pathway analysis suggested that regulation of actin cytoskeleton, oxidative phosphorylation, and focal adhesion were involved in the development of skeletal muscle. The findings from this study can contribute to future investigations of the growth and development mechanism in duck skeletal muscle.
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Affiliation(s)
| | | | | | | | | | - Xiaolin Liu
- College of Animal Science and Technology, Northwest A&F University, Yangling 712100, Shaanxi, China; (Z.H.); (J.C.); (J.Z.); (L.G.); (H.Z.)
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3
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Song Z, Liu Y, Fang X, Xie M, Ma Z, Zhong Z, Feng X, Zhang W. Comprehensive analysis of the expression profile of circRNAs and their predicted protein-coding ability in the muscle of mdx mice. Funct Integr Genomics 2019; 20:397-407. [PMID: 31736012 DOI: 10.1007/s10142-019-00724-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 07/17/2019] [Accepted: 11/05/2019] [Indexed: 12/25/2022]
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked genetic neuromuscular disease that is characterized by progressive muscle wasting and by defects in the regenerative capacity and inflammatory infiltration of muscle. Many noncoding RNAs (ncRNAs) participate in the pathophysiological mechanisms of this disease. To explore the role of circular RNAs (circRNAs), a type of ncRNAs, in DMD, microarray analysis was performed to explore the expression patterns of circRNAs in the gastrocnemius muscles in mdx mice, a DMD animal model, and C57 mice. The microarray data were validated by qRT-PCR. Further, gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed to predict the function of the differentially expressed circRNAs (DEcRNAs). A circRNA/microRNA (miRNA) interaction network was predicted by bioinformatics. We also predicted the protein-coding ability of the circRNAs based on their N6-methyladenosine motifs and open-reading frames. We identified 197 differentially expressed circRNAs between mdx mice and C57 mice. Of the 197 DEcRNAs, 6 circRNAs were randomly selected to validate the microarray data, and twenty-two circRNAs were randomly selected to construct a circRNA/miRNA interaction network. Bioinformatics analysis showed that the linear counterparts of the DEcRNAs were mainly associated with muscle structure, nervous system development, and the cAMP signaling pathway. A total of 189 circRNAs were predicted to have protein-coding potential, and there were 98 circRNAs that could potentially be translated into polypeptides with 150 or more amino acids. This work described the expression pattern of circRNAs in mdx mice and indicated that circRNAs may play pivotal roles in the pathophysiological mechanisms of DMD.
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Affiliation(s)
- Zubiao Song
- Department of Neurology, the First Affiliated Hospital, Sun Yat-sen University, No 58, Zhongshan 2 Road, Guangzhou, 510080, Guangdong Province, People's Republic of China
| | - Yanmei Liu
- Department of Neurology, the First Affiliated Hospital, Sun Yat-sen University, No 58, Zhongshan 2 Road, Guangzhou, 510080, Guangdong Province, People's Republic of China
| | - Xiaobo Fang
- Department of Neurology, the First Affiliated Hospital, Sun Yat-sen University, No 58, Zhongshan 2 Road, Guangzhou, 510080, Guangdong Province, People's Republic of China
| | - Mengshu Xie
- Department of Rehabilitation, the Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, People's Republic of China
| | - Zhenyu Ma
- Department of Neurology, the Second Affiliated Hospital, Guangzhou Medicine University, Guangzhou, Guangdong Province, People's Republic of China
| | - Zhigang Zhong
- Department of Neurology, Peking University Shenzhen Hospital, Shenzhen, Guangdong Province, People's Republic of China
| | - Xuelin Feng
- Department of Neurology, the First Affiliated Hospital, Sun Yat-sen University, No 58, Zhongshan 2 Road, Guangzhou, 510080, Guangdong Province, People's Republic of China
| | - Weixi Zhang
- Department of Neurology, the First Affiliated Hospital, Sun Yat-sen University, No 58, Zhongshan 2 Road, Guangzhou, 510080, Guangdong Province, People's Republic of China.
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4
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Bhat SS, Ali R, Khanday FA. Syntrophins entangled in cytoskeletal meshwork: Helping to hold it all together. Cell Prolif 2019; 52:e12562. [PMID: 30515904 PMCID: PMC6496184 DOI: 10.1111/cpr.12562] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 10/23/2018] [Accepted: 11/08/2018] [Indexed: 01/10/2023] Open
Abstract
Syntrophins are a family of 59 kDa peripheral membrane-associated adapter proteins, containing multiple protein-protein and protein-lipid interaction domains. The syntrophin family consists of five isoforms that exhibit specific tissue distribution, distinct sub-cellular localization and unique expression patterns implying their diverse functional roles. These syntrophin isoforms form multiple functional protein complexes and ensure proper localization of signalling proteins and their binding partners to specific membrane domains and provide appropriate spatiotemporal regulation of signalling pathways. Syntrophins consist of two PH domains, a PDZ domain and a conserved SU domain. The PH1 domain is split by the PDZ domain. The PH2 and the SU domain are involved in the interaction between syntrophin and the dystrophin-glycoprotein complex (DGC). Syntrophins recruit various signalling proteins to DGC and link extracellular matrix to internal signalling apparatus via DGC. The different domains of the syntrophin isoforms are responsible for modulation of cytoskeleton. Syntrophins associate with cytoskeletal proteins and lead to various cellular responses by modulating the cytoskeleton. Syntrophins are involved in many physiological processes which involve cytoskeletal reorganization like insulin secretion, blood pressure regulation, myogenesis, cell migration, formation and retraction of focal adhesions. Syntrophins have been implicated in various pathologies like Alzheimer's disease, muscular dystrophy, cancer. Their role in cytoskeletal organization and modulation makes them perfect candidates for further studies in various cancers and other ailments that involve cytoskeletal modulation. The role of syntrophins in cytoskeletal organization and modulation has not yet been comprehensively reviewed till now. This review focuses on syntrophins and highlights their role in cytoskeletal organization, modulation and dynamics via its involvement in different cell signalling networks.
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Affiliation(s)
- Sahar S. Bhat
- Division of BiotechnologySher‐e‐Kashmir University of Agricultural Sciences and Technology of KashmirSrinagarIndia
| | - Roshia Ali
- Department of BiotechnologyUniversity of KashmirSrinagarIndia
- Department of BiochemistryUniversity of KashmirSrinagarIndia
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5
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Leyva-Leyva M, Sandoval A, Felix R, González-Ramírez R. Biochemical and Functional Interplay Between Ion Channels and the Components of the Dystrophin-Associated Glycoprotein Complex. J Membr Biol 2018; 251:535-550. [PMID: 29779049 DOI: 10.1007/s00232-018-0036-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 05/09/2018] [Indexed: 12/19/2022]
Abstract
Dystrophin is a cytoskeleton-linked membrane protein that binds to a larger multiprotein assembly called the dystrophin-associated glycoprotein complex (DGC). The deficiency of dystrophin or the components of the DGC results in the loss of connection between the cytoskeleton and the extracellular matrix with significant pathophysiological implications in skeletal and cardiac muscle as well as in the nervous system. Although the DGC plays an important role in maintaining membrane stability, it can also be considered as a versatile and flexible molecular complex that contribute to the cellular organization and dynamics of a variety of proteins at specific locations in the plasma membrane. This review deals with the role of the DGC in transmembrane signaling by forming supramolecular assemblies for regulating ion channel localization and activity. These interactions are relevant for cell homeostasis, and its alterations may play a significant role in the etiology and pathogenesis of various disorders affecting muscle and nerve function.
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Affiliation(s)
- Margarita Leyva-Leyva
- Department of Molecular Biology and Histocompatibility, "Dr. Manuel Gea González" General Hospital, Mexico City, Mexico
| | - Alejandro Sandoval
- Faculty of Superior Studies Iztacala, National Autonomous University of Mexico (UNAM), Tlalnepantla, Mexico
| | - Ricardo Felix
- Department of Cell Biology, Center for Research and Advanced Studies of the National Polytechnic Institute (Cinvestav-IPN), Mexico City, Mexico.
| | - Ricardo González-Ramírez
- Department of Molecular Biology and Histocompatibility, "Dr. Manuel Gea González" General Hospital, Mexico City, Mexico.
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6
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González-Jamett AM, Baez-Matus X, Olivares MJ, Hinostroza F, Guerra-Fernández MJ, Vasquez-Navarrete J, Bui MT, Guicheney P, Romero NB, Bevilacqua JA, Bitoun M, Caviedes P, Cárdenas AM. Dynamin-2 mutations linked to Centronuclear Myopathy impair actin-dependent trafficking in muscle cells. Sci Rep 2017; 7:4580. [PMID: 28676641 PMCID: PMC5496902 DOI: 10.1038/s41598-017-04418-w] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 05/16/2017] [Indexed: 12/20/2022] Open
Abstract
Dynamin-2 is a ubiquitously expressed GTP-ase that mediates membrane remodeling. Recent findings indicate that dynamin-2 also regulates actin dynamics. Mutations in dynamin-2 cause dominant centronuclear myopathy (CNM), a congenital myopathy characterized by progressive weakness and atrophy of skeletal muscles. However, the muscle-specific roles of dynamin-2 affected by these mutations remain elusive. Here we show that, in muscle cells, the GTP-ase activity of dynamin-2 is involved in de novo actin polymerization as well as in actin-mediated trafficking of the glucose transporter GLUT4. Expression of dynamin-2 constructs carrying CNM-linked mutations disrupted the formation of new actin filaments as well as the stimulus-induced translocation of GLUT4 to the plasma membrane. Similarly, mature muscle fibers isolated from heterozygous knock-in mice that harbor the dynamin-2 mutation p.R465W, an animal model of CNM, exhibited altered actin organization, reduced actin polymerization and impaired insulin-induced translocation of GLUT4 to the sarcolemma. Moreover, GLUT4 displayed aberrant perinuclear accumulation in biopsies from CNM patients carrying dynamin-2 mutations, further suggesting trafficking defects. These results suggest that dynamin-2 is a key regulator of actin dynamics and GLUT4 trafficking in muscle cells. Our findings also support a model in which impairment of actin-dependent trafficking contributes to the pathological mechanism in dynamin-2-associated CNM.
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Affiliation(s)
- Arlek M González-Jamett
- Centro Interdisciplinario de Neurociencia de Valparaíso. Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile. .,Programa de Farmacología Molecular y Clinica, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
| | - Ximena Baez-Matus
- Centro Interdisciplinario de Neurociencia de Valparaíso. Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - María José Olivares
- Centro Interdisciplinario de Neurociencia de Valparaíso. Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Fernando Hinostroza
- Centro Interdisciplinario de Neurociencia de Valparaíso. Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.,Doctorado en Ciencias, mención Neurociencia, Universidad de Valparaíso, Valparaíso, Chile
| | - Maria José Guerra-Fernández
- Centro Interdisciplinario de Neurociencia de Valparaíso. Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Jacqueline Vasquez-Navarrete
- Centro Interdisciplinario de Neurociencia de Valparaíso. Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Mai Thao Bui
- Université Sorbonne, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, Paris, France.,Centre de référence de Pathologie Neuromusculaire Paris-Est, Institut de Myologie, GHU Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, GH Pitié-Salpêtrière, Paris, France
| | - Pascale Guicheney
- INSERM, UMR_S1166, Sorbonne Universités, UPMC Univ Paris 06, UMR_S1166, Institute of Cardiometabolism and Nutrition (ICAN), Paris, France
| | - Norma Beatriz Romero
- Université Sorbonne, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, Paris, France.,Centre de référence de Pathologie Neuromusculaire Paris-Est, Institut de Myologie, GHU Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, GH Pitié-Salpêtrière, Paris, France
| | - Jorge A Bevilacqua
- Programa de Anatomía y Biología del Desarrollo, ICBM, Facultad de Medicina, Departamento de Neurología y Neurocirugía, Hospital Clínico Universidad de Chile, Universidad de Chile, Santiago, Chile
| | - Marc Bitoun
- Research Center for Myology, UPMC Univ Paris 06 and INSERM UMRS 974, Institute of Myology, Paris, France
| | - Pablo Caviedes
- Programa de Farmacología Molecular y Clinica, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
| | - Ana M Cárdenas
- Centro Interdisciplinario de Neurociencia de Valparaíso. Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
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7
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Cairns SP, Borrani F. β-Adrenergic modulation of skeletal muscle contraction: key role of excitation-contraction coupling. J Physiol 2016; 593:4713-27. [PMID: 26400207 DOI: 10.1113/jp270909] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Accepted: 08/28/2015] [Indexed: 02/04/2023] Open
Abstract
Our aim is to describe the acute effects of catecholamines/β-adrenergic agonists on contraction of non-fatigued skeletal muscle in animals and humans, and explain the mechanisms involved. Adrenaline/β-agonists (0.1-30 μm) generally augment peak force across animal species (positive inotropic effect) and abbreviate relaxation of slow-twitch muscles (positive lusitropic effect). A peak force reduction also occurs in slow-twitch muscles in some conditions. β2 -Adrenoceptor stimulation activates distinct cyclic AMP-dependent protein kinases to phosphorylate multiple target proteins. β-Agonists modulate sarcolemmal processes (increased resting membrane potential and action potential amplitude) via enhanced Na(+) -K(+) pump and Na(+) -K(+) -2Cl(-) cotransporter function, but this does not increase force. Myofibrillar Ca(2+) sensitivity and maximum Ca(2+) -activated force are unchanged. All force potentiation involves amplified myoplasmic Ca(2+) transients consequent to increased Ca(2+) release from sarcoplasmic reticulum (SR). This unequivocally requires phosphorylation of SR Ca(2+) release channels/ryanodine receptors (RyR1) which sensitize the Ca(2+) -induced Ca(2+) release mechanism. Enhanced trans-sarcolemmal Ca(2+) influx through phosphorylated voltage-activated Ca(2+) channels contributes to force potentiation in diaphragm and amphibian muscle, but not mammalian limb muscle. Phosphorylation of phospholamban increases SR Ca(2+) pump activity in slow-twitch fibres but does not augment force; this process accelerates relaxation and may depress force. Greater Ca(2+) loading of SR may assist force potentiation in fast-twitch muscle. Some human studies show no significant force potentiation which appears to be related to the β-agonist concentration used. Indeed high-dose β-agonists (∼0.1 μm) enhance SR Ca(2+) -release rates, maximum voluntary contraction strength and peak Wingate power in trained humans. The combined findings can explain how adrenaline/β-agonists influence muscle performance during exercise/stress in humans.
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Affiliation(s)
- Simeon P Cairns
- Sports Performance Research Institute New Zealand, School of Sport and Recreation, Auckland University of Technology, Auckland, New Zealand.,Health and Rehabilitation Research Institute, Faculty of Health and Environmental Sciences, Auckland University of Technology, Auckland, New Zealand
| | - Fabio Borrani
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland.,Department of Physiology, University of Lausanne, Lausanne, Switzerland
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8
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Allen DG, Whitehead NP, Froehner SC. Absence of Dystrophin Disrupts Skeletal Muscle Signaling: Roles of Ca2+, Reactive Oxygen Species, and Nitric Oxide in the Development of Muscular Dystrophy. Physiol Rev 2016; 96:253-305. [PMID: 26676145 DOI: 10.1152/physrev.00007.2015] [Citation(s) in RCA: 294] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Dystrophin is a long rod-shaped protein that connects the subsarcolemmal cytoskeleton to a complex of proteins in the surface membrane (dystrophin protein complex, DPC), with further connections via laminin to other extracellular matrix proteins. Initially considered a structural complex that protected the sarcolemma from mechanical damage, the DPC is now known to serve as a scaffold for numerous signaling proteins. Absence or reduced expression of dystrophin or many of the DPC components cause the muscular dystrophies, a group of inherited diseases in which repeated bouts of muscle damage lead to atrophy and fibrosis, and eventually muscle degeneration. The normal function of dystrophin is poorly defined. In its absence a complex series of changes occur with multiple muscle proteins showing reduced or increased expression or being modified in various ways. In this review, we will consider the various proteins whose expression and function is changed in muscular dystrophies, focusing on Ca(2+)-permeable channels, nitric oxide synthase, NADPH oxidase, and caveolins. Excessive Ca(2+) entry, increased membrane permeability, disordered caveolar function, and increased levels of reactive oxygen species are early changes in the disease, and the hypotheses for these phenomena will be critically considered. The aim of the review is to define the early damage pathways in muscular dystrophy which might be appropriate targets for therapy designed to minimize the muscle degeneration and slow the progression of the disease.
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Affiliation(s)
- David G Allen
- Sydney Medical School & Bosch Institute, University of Sydney, New South Wales, Australia; and Department of Physiology & Biophysics, University of Washington, Seattle, Washington
| | - Nicholas P Whitehead
- Sydney Medical School & Bosch Institute, University of Sydney, New South Wales, Australia; and Department of Physiology & Biophysics, University of Washington, Seattle, Washington
| | - Stanley C Froehner
- Sydney Medical School & Bosch Institute, University of Sydney, New South Wales, Australia; and Department of Physiology & Biophysics, University of Washington, Seattle, Washington
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9
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Zhang X, Li F, Guo L, Hei H, Tian L, Peng W, Cai H. Forskolin Regulates L-Type Calcium Channel through Interaction between Actinin 4 and β3 Subunit in Osteoblasts. PLoS One 2015; 10:e0124274. [PMID: 25902045 PMCID: PMC4406748 DOI: 10.1371/journal.pone.0124274] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 03/11/2015] [Indexed: 12/23/2022] Open
Abstract
Voltage-dependent L-type calcium channels that permit cellular calcium influx are essential in calcium-mediated modulation of cellular signaling. Although the regulation of voltage-dependent L-type calcium channels is linked to many factors including cAMP-dependent protein kinase A (PKA) activity and actin cytoskeleton, little is known about the detailed mechanisms underlying the regulation in osteoblasts. Our present study investigated the modulation of L-type calcium channel activities through the effects of forskolin on actin reorganization and on its functional interaction with actin binding protein actinin 4. The results showed that forskolin did not significantly affect the trafficking of pore forming α1c subunit and its interaction with actin binding protein actinin 4, whereas it significantly increased the expression of β3 subunit and its interaction with actinin 4 in osteoblast cells as assessed by co-immunoprecipitation, pull-down assay, and immunostaining. Further mapping showed that the ABD and EF domains of actinin 4 were interaction sites. This interaction is independent of PKA phosphorylation. Knockdown of actinin 4 significantly decreased the activities of L-type calcium channels. Our study revealed a new aspect of the mechanisms by which the forskolin activation of adenylyl cyclase - cAMP cascade regulates the L-type calcium channel in osteoblast cells, besides the PKA mediated phosphorylation of the channel subunits. These data provide insight into the important role of interconnection among adenylyl cyclase, cAMP, PKA, the actin cytoskeleton, and the channel proteins in the regulation of voltage-dependent L-type calcium channels in osteoblast cells.
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Affiliation(s)
- Xuemei Zhang
- Department of Pharmacology, School of Pharmacy, Fudan University, 826 Zhangheng Road, Pudong New District, Shanghai, 201203, China
- * E-mail: (XZ); (WP)
| | - Fangping Li
- Department of Pharmacy, Jing’an District Center Hospital of Shanghai (Huashan Hospital, Fudan University, Jing’an Branch), 259 Xikang Road, Shanghai, 200040, China
| | - Lin Guo
- Department of Pharmacology, School of Pharmacy, Fudan University, 826 Zhangheng Road, Pudong New District, Shanghai, 201203, China
| | - Hongya Hei
- Department of Pharmacology, School of Pharmacy, Fudan University, 826 Zhangheng Road, Pudong New District, Shanghai, 201203, China
| | - Lulu Tian
- Department of Pharmacology, School of Pharmacy, Fudan University, 826 Zhangheng Road, Pudong New District, Shanghai, 201203, China
| | - Wen Peng
- Department of Nephrology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine,164 Lanxi Road, Shanghai, 200062, PR China
- * E-mail: (XZ); (WP)
| | - Hui Cai
- Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, GA, 30322, United States of America
- Renal Section, Atlanta Veteran Administration Medical Center, Decatur, GA, 30033, United States of America
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10
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Koenig X, Rubi L, Obermair GJ, Cervenka R, Dang XB, Lukacs P, Kummer S, Bittner RE, Kubista H, Todt H, Hilber K. Enhanced currents through L-type calcium channels in cardiomyocytes disturb the electrophysiology of the dystrophic heart. Am J Physiol Heart Circ Physiol 2013; 306:H564-H573. [PMID: 24337461 DOI: 10.1152/ajpheart.00441.2013] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Duchenne muscular dystrophy (DMD), induced by mutations in the gene encoding for the cytoskeletal protein dystrophin, is an inherited disease characterized by progressive muscle weakness. Besides the relatively well characterized skeletal muscle degenerative processes, DMD is also associated with cardiac complications. These include cardiomyopathy development and cardiac arrhythmias. The current understanding of the pathomechanisms in the heart is very limited, but recent research indicates that dysfunctional ion channels in dystrophic cardiomyocytes play a role. The aim of the present study was to characterize abnormalities in L-type calcium channel function in adult dystrophic ventricular cardiomyocytes. By using the whole cell patch-clamp technique, the properties of currents through calcium channels in ventricular cardiomyocytes isolated from the hearts of normal and dystrophic adult mice were compared. Besides the commonly used dystrophin-deficient mdx mouse model for human DMD, we also used mdx-utr mice, which are both dystrophin- and utrophin-deficient. We found that calcium channel currents were significantly increased, and channel inactivation was reduced in dystrophic cardiomyocytes. Both effects enhance the calcium influx during an action potential (AP). Whereas the AP in dystrophic mouse cardiomyocytes was nearly normal, implementation of the enhanced dystrophic calcium conductance in a computer model of a human ventricular cardiomyocyte considerably prolonged the AP. Finally, the described dystrophic calcium channel abnormalities entailed alterations in the electrocardiograms of dystrophic mice. We conclude that gain of function in cardiac L-type calcium channels may disturb the electrophysiology of the dystrophic heart and thereby cause arrhythmias.
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Affiliation(s)
- Xaver Koenig
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Lena Rubi
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Gerald J Obermair
- Department of Physiology and Medical Physics, Medical University Innsbruck, Innsbruck, Austria
| | - Rene Cervenka
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Xuan B Dang
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Peter Lukacs
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Stefan Kummer
- Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Reginald E Bittner
- Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Helmut Kubista
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Hannes Todt
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Karlheinz Hilber
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
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11
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Johnson EK, Li B, Yoon JH, Flanigan KM, Martin PT, Ervasti J, Montanaro F. Identification of new dystroglycan complexes in skeletal muscle. PLoS One 2013; 8:e73224. [PMID: 23951345 PMCID: PMC3738564 DOI: 10.1371/journal.pone.0073224] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 07/18/2013] [Indexed: 01/16/2023] Open
Abstract
The dystroglycan complex contains the transmembrane protein β-dystroglycan and its interacting extracellular mucin-like protein α-dystroglycan. In skeletal muscle fibers, the dystroglycan complex plays an important structural role by linking the cytoskeletal protein dystrophin to laminin in the extracellular matrix. Mutations that affect any of the proteins involved in this structural axis lead to myofiber degeneration and are associated with muscular dystrophies and congenital myopathies. Because loss of dystrophin in Duchenne muscular dystrophy (DMD) leads to an almost complete loss of dystroglycan complexes at the myofiber membrane, it is generally assumed that the vast majority of dystroglycan complexes within skeletal muscle fibers interact with dystrophin. The residual dystroglycan present in dystrophin-deficient muscle is thought to be preserved by utrophin, a structural homolog of dystrophin that is up-regulated in dystrophic muscles. However, we found that dystroglycan complexes are still present at the myofiber membrane in the absence of both dystrophin and utrophin. Our data show that only a minority of dystroglycan complexes associate with dystrophin in wild type muscle. Furthermore, we provide evidence for at least three separate pools of dystroglycan complexes within myofibers that differ in composition and are differentially affected by loss of dystrophin. Our findings indicate a more complex role of dystroglycan in muscle than currently recognized and may help explain differences in disease pathology and severity among myopathies linked to mutations in DAPC members.
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Affiliation(s)
- Eric K. Johnson
- Center for Gene Therapy, the Research Institute at Nationwide Children’s Hospital, and The Ohio State University Biochemistry Program, Columbus, Ohio, United States of America
- Ohio State Biochemistry Program, the Ohio State University, Columbus, Ohio, United States of America
| | - Bin Li
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Jung Hae Yoon
- Center for Gene Therapy, the Research Institute at Nationwide Children’s Hospital, and The Ohio State University Biochemistry Program, Columbus, Ohio, United States of America
| | - Kevin M. Flanigan
- Center for Gene Therapy, the Research Institute at Nationwide Children’s Hospital, and The Ohio State University Biochemistry Program, Columbus, Ohio, United States of America
- Department of Pediatrics, the Ohio State University College of Medicine, Columbus, Ohio, United States of America
| | - Paul T. Martin
- Center for Gene Therapy, the Research Institute at Nationwide Children’s Hospital, and The Ohio State University Biochemistry Program, Columbus, Ohio, United States of America
- Department of Pediatrics, the Ohio State University College of Medicine, Columbus, Ohio, United States of America
| | - James Ervasti
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Federica Montanaro
- Center for Gene Therapy, the Research Institute at Nationwide Children’s Hospital, and The Ohio State University Biochemistry Program, Columbus, Ohio, United States of America
- Ohio State Biochemistry Program, the Ohio State University, Columbus, Ohio, United States of America
- Department of Pediatrics, the Ohio State University College of Medicine, Columbus, Ohio, United States of America
- * E-mail:
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12
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Narayanan T, Subramaniam S. Community Structure Analysis of Gene Interaction Networks in Duchenne Muscular Dystrophy. PLoS One 2013; 8:e67237. [PMID: 23840633 PMCID: PMC3686745 DOI: 10.1371/journal.pone.0067237] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 05/14/2013] [Indexed: 02/07/2023] Open
Abstract
Duchenne Muscular Dystrophy (DMD) is an important pathology associated with the human skeletal muscle and has been studied extensively. Gene expression measurements on skeletal muscle of patients afflicted with DMD provides the opportunity to understand the underlying mechanisms that lead to the pathology. Community structure analysis is a useful computational technique for understanding and modeling genetic interaction networks. In this paper, we leverage this technique in combination with gene expression measurements from normal and DMD patient skeletal muscle tissue to study the structure of genetic interactions in the context of DMD. We define a novel framework for transforming a raw dataset of gene expression measurements into an interaction network, and subsequently apply algorithms for community structure analysis for the extraction of topological communities. The emergent communities are analyzed from a biological standpoint in terms of their constituent biological pathways, and an interpretation that draws correlations between functional and structural organization of the genetic interactions is presented. We also compare these communities and associated functions in pathology against those in normal human skeletal muscle. In particular, differential enhancements are observed in the following pathways between pathological and normal cases: Metabolic, Focal adhesion, Regulation of actin cytoskeleton and Cell adhesion, and implication of these mechanisms are supported by prior work. Furthermore, our study also includes a gene-level analysis to identify genes that are involved in the coupling between the pathways of interest. We believe that our results serve to highlight important distinguishing features in the structural/functional organization of constituent biological pathways, as it relates to normal and DMD cases, and provide the mechanistic basis for further biological investigations into specific pathways differently regulated between normal and DMD patients. These findings have the potential to serve as fertile ground for therapeutic applications involving targeted drug development for DMD.
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Affiliation(s)
- Tejaswini Narayanan
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, California, United States of America
| | - Shankar Subramaniam
- Department of Bioengineering, University of California San Diego, La Jolla, California, United States of America
- * E-mail:
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13
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Kappel VD, Zanatta L, Postal BG, Silva FRMB. Rutin potentiates calcium uptake via voltage-dependent calcium channel associated with stimulation of glucose uptake in skeletal muscle. Arch Biochem Biophys 2013; 532:55-60. [PMID: 23395857 DOI: 10.1016/j.abb.2013.01.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 01/19/2013] [Accepted: 01/23/2013] [Indexed: 11/29/2022]
Abstract
Rutin is a flavonoid with several pharmacological properties and it has been demonstrated that rutin can modulate glucose homeostasis. In skeletal muscle, an increase in intracellular calcium concentration may induce glucose transporter-4 (GLUT-4) translocation with consequent glucose uptake. The aim of this study was to investigate the effect of rutin and intracellular pathways on calcium uptake as well as the involvement of calcium in glucose uptake in skeletal muscle. The results show that rutin significantly stimulated calcium uptake through voltage-dependent calcium channels as well as mitogen-activated kinase (MEK) and protein kinase A (PKA) signaling pathways. Also, rutin stimulated glucose uptake in the soleus muscle and this effect was mediated by extracellular calcium and calcium-calmodulin-dependent protein kinase II (CaMKII) activation. In conclusion, rutin significantly stimulates calcium uptake in rat soleus muscles. Furthermore, the increase in intracellular calcium concentration is involved in DNA activation by rutin. Also, rutin-induced glucose uptake via CaMKII may result in GLUT-4 translocation to the plasma membrane, characterizing an insulin-independent pathway. These findings indicate that rutin is a potential drug candidate for diabetes therapy.
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Affiliation(s)
- Virginia Demarchi Kappel
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis-Santa Catarina, Brazil
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14
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Zanatta L, Goulart PB, Gonçalves R, Pierozan P, Winkelmann-Duarte EC, Woehl VM, Pessoa-Pureur R, Silva FRMB, Zamoner A. 1α,25-Dihydroxyvitamin D3 mechanism of action: Modulation of L-type calcium channels leading to calcium uptake and intermediate filament phosphorylation in cerebral cortex of young rats. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1823:1708-19. [DOI: 10.1016/j.bbamcr.2012.06.023] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 06/15/2012] [Accepted: 06/18/2012] [Indexed: 12/22/2022]
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15
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Reutenauer-Patte J, Boittin FX, Patthey-Vuadens O, Ruegg UT, Dorchies OM. Urocortins improve dystrophic skeletal muscle structure and function through both PKA- and Epac-dependent pathways. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 180:749-62. [PMID: 22192627 DOI: 10.1016/j.ajpath.2011.10.038] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Revised: 10/14/2011] [Accepted: 10/23/2011] [Indexed: 02/03/2023]
Abstract
In Duchenne muscular dystrophy, the absence of dystrophin causes progressive muscle wasting and premature death. Excessive calcium influx is thought to initiate the pathogenic cascade, resulting in muscle cell death. Urocortins (Ucns) have protected muscle in several experimental paradigms. Herein, we demonstrate that daily s.c. injections of either Ucn 1 or Ucn 2 to 3-week-old dystrophic mdx(5Cv) mice for 2 weeks increased skeletal muscle mass and normalized plasma creatine kinase activity. Histological examination showed that Ucns remarkably reduced necrosis in the diaphragm and slow- and fast-twitch muscles. Ucns improved muscle resistance to mechanical stress provoked by repetitive tetanizations. Ucn 2 treatment resulted in faster kinetics of contraction and relaxation and a rightward shift of the force-frequency curve, suggesting improved calcium homeostasis. Ucn 2 decreased calcium influx into freshly isolated dystrophic muscles. Pharmacological manipulation demonstrated that the mechanism involved the corticotropin-releasing factor type 2 receptor, cAMP elevation, and activation of both protein kinase A and the cAMP-binding protein Epac. Moreover, both STIM1, the calcium sensor that initiates the assembly of store-operated channels, and the calcium-independent phospholipase A(2) that activates these channels were reduced in dystrophic muscle by Ucn 2. Altogether, our results demonstrate the high potency of Ucns for improving dystrophic muscle structure and function, suggesting that these peptides may be considered for treatment of Duchenne muscular dystrophy.
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Affiliation(s)
- Julie Reutenauer-Patte
- Laboratory of Pharmacology, Geneva-Lausanne School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Geneva, Switzerland
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16
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Li F, Wang W, Gu M, Gyoneva S, Zhang J, Huang S, Traynelis SF, Cai H, Guggino SE, Zhang X. L-type calcium channel activity in osteoblast cells is regulated by the actin cytoskeleton independent of protein trafficking. J Bone Miner Metab 2011; 29:515-25. [PMID: 21246227 DOI: 10.1007/s00774-010-0252-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Accepted: 11/14/2010] [Indexed: 11/27/2022]
Abstract
Voltage-dependent L-type calcium channels (VDCC) play important roles in many cellular processes. The interaction of the actin cytoskeleton with the channel in nonexcitable cells is less well understood. We performed whole-cell patch-clamp surface biotinylation and calcium imaging on different osteoblast cells to determine channel kinetics, amplitude, surface abundance, and intracellular calcium, respectively. Patch-clamp studies showed that actin polymerization by phalloidin increased the peak current density of I (Ca), whereas actin depolymerization by cytochalasin D (CD) significantly decreased the current amplitude. This result is consistent with calcium imaging, which showed that CD significantly decreased Bay K8644-induced intracellular calcium increase. Surface biotinylation studies showed that CD is not able to affect the surface expression of the pore-forming subunit α(1C). Interestingly, application of CD caused a significantly negative shift in the steady-state inactivation kinetics of I (Ca). There were decreases in the voltage at half-maximal inactivation that changed in a dose-dependent manner. CD also reduced the effect of activated vitamin D(3) (1α,25-D3) on VDCC and intracellular calcium. We conclude that in osteoblasts the actin cytoskeleton affects α(1C) by altering the channel kinetic properties, instead of changing the surface expression, and it is able to regulate 1α,25-D3 signaling through VDCC. Our study provides a new insight into calcium regulation in osteoblasts, which are essential in many physiological functions of this cell.
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Affiliation(s)
- Fangping Li
- Department of Pharmacology, School of Pharmacy, Fudan University, Pudong New District, Shanghai, China
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17
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Ke L, Meijering RAM, Hoogstra-Berends F, Mackovicova K, Vos MJ, Van Gelder IC, Henning RH, Kampinga HH, Brundel BJJM. HSPB1, HSPB6, HSPB7 and HSPB8 protect against RhoA GTPase-induced remodeling in tachypaced atrial myocytes. PLoS One 2011; 6:e20395. [PMID: 21731611 PMCID: PMC3123278 DOI: 10.1371/journal.pone.0020395] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Accepted: 04/28/2011] [Indexed: 11/29/2022] Open
Abstract
Background We previously demonstrated the small heat shock protein, HSPB1, to prevent tachycardia remodeling in in vitro and in vivo models for Atrial Fibrillation (AF). To gain insight into its mechanism of action, we examined the protective effect of all 10 members of the HSPB family on tachycardia remodeling. Furthermore, modulating effects of HSPB on RhoA GTPase activity and F-actin stress fiber formation were examined, as this pathway was found of prime importance in tachycardia remodeling events and the initiation of AF. Methods and Results Tachypacing (4 Hz) of HL-1 atrial myocytes significantly and progressively reduced the amplitude of Ca2+ transients (CaT). In addition to HSPB1, also overexpression of HSPB6, HSPB7 and HSPB8 protected against tachypacing-induced CaT reduction. The protective effect was independent of HSPB1. Moreover, tachypacing induced RhoA GTPase activity and caused F-actin stress fiber formation. The ROCK inhibitor Y27632 significantly prevented tachypacing-induced F-actin formation and CaT reductions, showing that RhoA activation is required for remodeling. Although all protective HSPB members prevented the formation of F-actin stress fibers, their mode of action differs. Whilst HSPB1, HSPB6 and HSPB7 acted via direct prevention of F-actin formation, HSPB8-protection was mediated via inhibition of RhoA GTPase activity. Conclusion Overexpression of HSPB1, as well as HSPB6, HSPB7 and HSPB8 independently protect against tachycardia remodeling by attenuation of the RhoA GTPase pathway at different levels. The cardioprotective role for multiple HSPB members indicate a possible therapeutic benefit of compounds able to boost the expression of single or multiple members of the HSPB family.
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Affiliation(s)
- Lei Ke
- Department of Radiation and Stress Cell Biology, University Institute for Drug Exploration (GUIDE), University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Roelien A. M. Meijering
- Department of Clinical Pharmacology, GUIDE, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Femke Hoogstra-Berends
- Department of Clinical Pharmacology, GUIDE, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Nyken BV, Groningen, The Netherlands
| | - Katarina Mackovicova
- Department of Clinical Pharmacology, GUIDE, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Michel J. Vos
- Department of Radiation and Stress Cell Biology, University Institute for Drug Exploration (GUIDE), University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Isabelle C. Van Gelder
- Department of Cardiology, GUIDE, University of Groningen, University Medical Center Groningen, and the Interuniversity Cardiology Institute Netherlands, Utrecht, The Netherlands
| | - Robert H. Henning
- Department of Clinical Pharmacology, GUIDE, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Harm H. Kampinga
- Department of Radiation and Stress Cell Biology, University Institute for Drug Exploration (GUIDE), University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Bianca J. J. M. Brundel
- Department of Clinical Pharmacology, GUIDE, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- * E-mail:
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18
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Abstract
Two known zebrafish dystrophin mutants, sapje and sapje-like (sap(c/100)), represent excellent small-animal models of human muscular dystrophy. Using these dystrophin-null zebrafish, we have screened the Prestwick chemical library for small molecules that modulate the muscle phenotype in these fish. With a quick and easy birefringence assay, we have identified seven small molecules that influence muscle pathology in dystrophin-null zebrafish without restoration of dystrophin expression. Three of seven candidate chemicals restored normal birefringence and increased survival of dystrophin-null fish. One chemical, aminophylline, which is known to be a nonselective phosphodiesterase (PDE) inhibitor, had the greatest ability to restore normal muscle structure and up-regulate the cAMP-dependent PKA pathway in treated dystrophin-deficient fish. Moreover, other PDE inhibitors also reduced the percentage of affected sapje fish. The identification of compounds, especially PDE inhibitors, that moderate the muscle phenotype in these dystrophin-null zebrafish validates the screening protocol described here and may lead to candidate molecules to be used as therapeutic interventions in human muscular dystrophy.
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19
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Multiple kinase pathways regulate voltage-dependent Ca2+ influx and migration in oligodendrocyte precursor cells. J Neurosci 2010; 30:6422-33. [PMID: 20445068 DOI: 10.1523/jneurosci.5086-09.2010] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
It is becoming increasingly clear that voltage-operated Ca(2+) channels (VOCCs) play a fundamental role in the development of oligodendrocyte progenitor cells (OPCs). Because direct phosphorylation by different kinases is one of the most important mechanisms involved in VOCC modulation, the aim of this study was to evaluate the participation of serine-threonine kinases and tyrosine kinases (TKs) on Ca(2+) influx mediated by VOCCs in OPCs. Calcium imaging revealed that OPCs exhibited Ca(2+) influx after plasma membrane depolarization via L-type VOCCs. Furthermore, VOCC-mediated Ca(2+) influx declined with OPC differentiation, indicating that VOCCs are developmentally regulated in OPCs. PKC activation significantly increased VOCC activity in OPCs, whereas PKA activation produced the opposite effect. The results also indicated that OPC morphological changes induced by PKC activation were partially mediated by VOCCs. Our data clearly suggest that TKs exert an activating influence on VOCC function in OPCs. Furthermore, using the PDGF response as a model to probe the role of TK receptors (TKr) on OPC Ca(2+) uptake, we found that TKr activation potentiated Ca(2+) influx after membrane depolarization. Interestingly, this TKr modulation of VOCCs appeared to be essential for the PDGF enhancement of OPC migration rate, because cell motility was completely blocked by TKr antagonists, as well as VOCC inhibitors, in migration assays. The present study strongly demonstrates that PKC and TKrs enhance Ca(2+) influx induced by depolarization in OPCs, whereas PKA has an inhibitory effect. These kinases modulate voltage-operated Ca(2+) uptake in OPCs and participate in the modulation of process extension and migration.
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20
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Head SI. Branched fibres in old dystrophicmdxmuscle are associated with mechanical weakening of the sarcolemma, abnormal Ca2+transients and a breakdown of Ca2+homeostasis during fatigue. Exp Physiol 2010; 95:641-56. [DOI: 10.1113/expphysiol.2009.052019] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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21
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Kee AJ, Gunning PW, Hardeman EC. Diverse roles of the actin cytoskeleton in striated muscle. J Muscle Res Cell Motil 2009; 30:187-97. [PMID: 19997772 DOI: 10.1007/s10974-009-9193-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2009] [Accepted: 11/24/2009] [Indexed: 12/14/2022]
Abstract
In addition to the highly specialized contractile apparatus, it is becoming increasingly clear that there is an extensive actin cytoskeleton which underpins a wide range of functions in striated muscle. Isoforms of cytoskeletal actin and actin-associated proteins (non-muscle myosins, cytoskeletal tropomyosins, and cytoskeletal alpha-actinins) have been detected in a number of regions of striated muscle: the sub-sarcolemmal costamere, the Z-disc and the T-tubule/sarcoplasmic reticulum membranes. As the only known function of these proteins is through association with actin filaments, their presence in striated muscles indicates that there are spatially and functionally distinct cytoskeletal actin filament systems in these tissues. These filaments are likely to have important roles in mechanical support, ion channel function, myofibrillogenenous and vesicle trafficking.
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Affiliation(s)
- Anthony J Kee
- Department of Anatomy, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
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22
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Vandenburgh H, Shansky J, Benesch-Lee F, Skelly K, Spinazzola JM, Saponjian Y, Tseng BS. Automated drug screening with contractile muscle tissue engineered from dystrophic myoblasts. FASEB J 2009; 23:3325-34. [PMID: 19487307 DOI: 10.1096/fj.09-134411] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Identification of factors that improve muscle function in boys with Duchenne muscular dystrophy (DMD) could lead to an improved quality of life. To establish a functional in vitro assay for muscle strength, mdx murine myoblasts, the genetic homologue of DMD, were tissue engineered in 96-microwell plates into 3-dimensional muscle constructs with parallel arrays of striated muscle fibers. When electrically stimulated, they generated tetanic forces measured with an automated motion tracking system. Thirty-one compounds of interest as potential treatments for patients with DMD were tested at 3 to 6 concentrations. Eleven of the compounds (insulin-like growth factor-1, creatine, beta-hydroxy-beta-methylbutyrate, trichostatin A, lisinopril, and 6 from the glucocorticoid family) significantly increased tetanic force relative to placebo-treated controls. The glucocorticoids methylprednisolone, deflazacort, and prednisone increased tetanic forces at low doses (EC(50) of 6, 19, and 56 nM, respectively), indicating a direct muscle mechanism by which they may be benefitting DMD patients. The tetanic force assay also identified beneficial compound interactions (arginine plus deflazacort and prednisone plus creatine) as well as deleterious interactions (prednisone plus creatine inhibited by pentoxifylline) of combinatorial therapies taken by some DMD patients. Since mdx muscle in vivo and DMD patients respond in a similar manner to many of these compounds, the in vitro assay will be a useful tool for the rapid identification of new potential treatments for muscle weakness in DMD and other muscle disorders.
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Affiliation(s)
- Herman Vandenburgh
- Department of Pathology, Brown Medical School-Miriam Hospital, Providence, Rhode Island, USA.
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23
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Launikonis BS, Stephenson DG, Friedrich O. Rapid Ca2+ flux through the transverse tubular membrane, activated by individual action potentials in mammalian skeletal muscle. J Physiol 2009; 587:2299-312. [PMID: 19332499 DOI: 10.1113/jphysiol.2009.168682] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Periods of low frequency stimulation are known to increase the net Ca(2+) uptake in skeletal muscle but the mechanism responsible for this Ca(2+) entry is not known. In this study a novel high-resolution fluorescence microscopy approach allowed the detection of an action potential-induced Ca(2+) flux across the tubular (t-) system of rat extensor digitorum longus muscle fibres that appears to be responsible for the net uptake of Ca(2+) in working muscle. Action potentials were triggered in the t-system of mechanically skinned fibres from rat by brief field stimulation and t-system [Ca(2+)] ([Ca(2+)](t-sys)) and cytoplasmic [Ca(2+)] ([Ca(2+)](cyto)) were simultaneously resolved on a confocal microscope. When initial [Ca(2+)](t-sys) was > or = 0.2 mM a Ca(2+) flux from t-system to the cytoplasm was observed following a single action potential. The action potential-induced Ca(2+) flux and associated t-system Ca(2+) permeability decayed exponentially and displayed inactivation characteristics such that further Ca(2+) entry across the t-system could not be observed after 2-3 action potentials at 10 Hz stimulation rate. When [Ca(2+)](t-sys) was closer to 0.1 mM, a transient rise in [Ca(2+)](t-sys) was observed almost concurrently with the increase in [Ca(2+)](cyto) following the action potential. The change in direction of Ca(2+) flux was consistent with changes in the direction of the driving force for Ca(2+). This is the first demonstration of a rapid t-system Ca(2+) flux associated with a single action potential in mammalian skeletal muscle. The properties of this channel are inconsistent with a flux through the L-type Ca(2+) channel suggesting that an as yet unidentified t-system protein is conducting this current. This action potential-activated Ca(2+) flux provides an explanation for the previously described Ca(2+) entry and accumulation observed with prolonged, intermittent muscle activity.
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Affiliation(s)
- Bradley S Launikonis
- School of Biomedical Sciences, University of Queensland, Brisbane, Qld 4072, Australia.
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Röder IV, Lissandron V, Martin J, Petersen Y, Di Benedetto G, Zaccolo M, Rudolf R. PKA microdomain organisation and cAMP handling in healthy and dystrophic muscle in vivo. Cell Signal 2009; 21:819-26. [PMID: 19263518 DOI: 10.1016/j.cellsig.2009.01.029] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Signalling through protein kinase A (PKA) triggers a multitude of intracellular effects in response to a variety of extracellular stimuli. To guarantee signal specificity, different PKA isoforms are compartmentalised by Akinase anchoring proteins (AKAPs) into functional microdomains. By using genetically encoded fluorescent reporters of cAMP concentration that are targeted to the intracellular sites where PKA type I and PKA type II isoforms normally reside, we directly show for the first time spatially and functionally separate PKA microdomains in mouse skeletal muscle in vivo. The reporters localised into clearly distinct patterns within sarcomers, from where they could be displaced by means of AKAP disruptor peptides indicating the presence of disparate PKA type I and PKA type II anchor sites within skeletal muscle fibres. The functional relevance of such differential localisation was underscored by the finding of mutually exclusive and AKAP-dependent increases in [cAMP] in the PKA type I and PKA type II microdomains upon application of different cAMP agonists. Specifically, the sensors targeted to the PKA type II compartment responded only to norepinephrine, whereas those targeted to the PKA type I compartment responded only to alpha-calcitonin gene-related peptide. Notably, in dystrophic mdx mice the localisation pattern of the reporters was altered and the functional separation of the cAMP microdomains was abolished. In summary, our data indicate that an efficient organisation in microdomains of the cAMP/PKA pathway exists in the healthy skeletal muscle and that such organisation is subverted in dystrophic skeletal muscle.
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Affiliation(s)
- Ira Verena Röder
- Institute of Toxicology and Genetics, Forschungszentrum Karlsruhe, 76344 Eggenstein-Leopoldshafen, Germany
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25
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Teichmann MDH, Wegner FV, Fink RHA, Chamberlain JS, Launikonis BS, Martinac B, Friedrich O. Inhibitory control over Ca(2+) sparks via mechanosensitive channels is disrupted in dystrophin deficient muscle but restored by mini-dystrophin expression. PLoS One 2008; 3:e3644. [PMID: 18982068 PMCID: PMC2575405 DOI: 10.1371/journal.pone.0003644] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2008] [Accepted: 10/17/2008] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND In dystrophic skeletal muscle, osmotic stimuli somehow relieve inhibitory control of dihydropyridine receptors (DHPR) on spontaneous sarcoplasmic reticulum elementary Ca(2+) release events (ECRE) in high Ca(2+) external environments. Such 'uncontrolled' Ca(2+) sparks were suggested to act as dystrophic signals. They may be related to mechanosensitive pathways but the mechanisms are elusive. Also, it is not known whether truncated dystrophins can correct the dystrophic disinhibition. METHODOLOGY/PRINCIPAL FINDINGS We recorded ECRE activity in single intact fibers from adult wt, mdx and mini-dystrophin expressing mice (MinD) under resting isotonic conditions and following hyper-/hypo-osmolar external shock using confocal microscopy and imaging techniques. Isotonic ECRE frequencies were small in wt and MinD fibers, but were markedly increased in mdx fibers. Osmotic challenge dramatically increased ECRE activity in mdx fibers. Sustained osmotic challenge induced marked exponential ECRE activity adaptation that was three times faster in mdx compared to wt and MinD fibers. Rising external Ca(2+) concentrations amplified osmotic ECRE responses. The eliminated ECRE suppression in intact osmotically stressed mdx fibers was completely and reversibly resuscitated by streptomycine (200 microM), spider peptide GsMTx-4 (5 microM) and Gd(3+) (20 microM) that block unspecific, specific cationic and Ca(2+) selective mechanosensitive channels (MsC), respectively. ECRE morphology was not substantially altered by membrane stress. During hyperosmotic challenge, membrane potentials were polarised and a putative depolarisation through aberrant MsC negligible excluding direct activation of ECRE through tubular depolarisation. CONCLUSIONS/SIGNIFICANCE Dystrophin suppresses spontaneous ECRE activity by control of mechanosensitive pathways which are suggested to interact with the inhibitory DHPR loop to the ryanodine receptor. MsC-related disinhibition prevails in dystrophic muscle and can be resuscitated by transgenic mini-dystrophin expression. Our results have important implications for the pathophysiology of DMD where abnormal MsC in dystrophic muscle confer disruption of microdomain Ca(2+) homeostasis. MsC blockers should have considerable therapeutic potential if more muscle specific compounds can be found.
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MESH Headings
- Adult
- Animals
- Calcium Channels, L-Type/metabolism
- Calcium Signaling/physiology
- Dystrophin/genetics
- Dystrophin/metabolism
- Humans
- Ion Channels/metabolism
- Mechanotransduction, Cellular/physiology
- Membrane Potentials/physiology
- Mice
- Mice, Inbred C57BL
- Mice, Inbred mdx
- Mice, Transgenic
- Muscle Fibers, Skeletal/cytology
- Muscle Fibers, Skeletal/physiology
- Muscle, Skeletal/cytology
- Muscle, Skeletal/physiology
- Muscle, Skeletal/physiopathology
- Muscular Dystrophy, Duchenne/physiopathology
- Osmotic Pressure
- Ryanodine Receptor Calcium Release Channel/metabolism
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Affiliation(s)
- Martin D. H. Teichmann
- Medical Biophysics, Department of Systems Physiology, Institute of Physiology and Pathophysiology, Ruprecht-Karls-University, Heidelberg, Germany
| | - Frederic v. Wegner
- Medical Biophysics, Department of Systems Physiology, Institute of Physiology and Pathophysiology, Ruprecht-Karls-University, Heidelberg, Germany
| | - Rainer H. A. Fink
- Medical Biophysics, Department of Systems Physiology, Institute of Physiology and Pathophysiology, Ruprecht-Karls-University, Heidelberg, Germany
| | - Jeffrey S. Chamberlain
- Department of Neurology, University of Washington, Seattle, Washington, United States of America
| | - Bradley S. Launikonis
- School of Biomedical Sciences, University of Queensland, Brisbane, Queensland, Australia
| | - Boris Martinac
- School of Biomedical Sciences, University of Queensland, Brisbane, Queensland, Australia
| | - Oliver Friedrich
- Medical Biophysics, Department of Systems Physiology, Institute of Physiology and Pathophysiology, Ruprecht-Karls-University, Heidelberg, Germany
- School of Biomedical Sciences, University of Queensland, Brisbane, Queensland, Australia
- * E-mail:
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26
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Mille M, Koenig X, Zebedin E, Uhrin P, Cervenka R, Todt H, Hilber K. Sodium current properties of primary skeletal myocytes and cardiomyocytes derived from different mouse strains. Pflugers Arch 2008; 457:1023-33. [PMID: 18704489 DOI: 10.1007/s00424-008-0570-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2008] [Revised: 07/25/2008] [Accepted: 07/30/2008] [Indexed: 10/21/2022]
Abstract
The mouse has become the preferred animal for genetic manipulations. Because of the diverse genetic backgrounds of various mouse strains, these can manifest strikingly different characteristics. Here, we studied the functional properties of currents through voltage-gated sodium channels in primary cultures of skeletal myocytes and cardiomyocytes derived from the three commonly used mouse strains BL6, 129/Sv, and FVB, by using the whole-cell patch-clamp technique. We found strain-specific sodium current function in skeletal myocytes, which could partly be explained by differences in sodium channel isoform expression. In addition, we found significant effects of cell source (neonatal or adult animal-derived) and variation of the differentiation time period. In contrast to skeletal myocytes, sodium current function in cardiomyocytes was similar in all strains. Our findings are relevant for the design and proper interpretation of electrophysiological studies, which use excitable cells in primary culture as a model system.
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Affiliation(s)
- M Mille
- Institute of Pharmacology, Center for Biomolecular Medicine and Pharmacology, Medical University of Vienna, Austria
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27
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Dystrophin and utrophin isoforms are expressed in glia, but not neurons, of the avian parasympathetic ciliary ganglion. Brain Res 2008; 1218:21-34. [PMID: 18533135 DOI: 10.1016/j.brainres.2008.04.071] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Revised: 04/14/2008] [Accepted: 04/20/2008] [Indexed: 11/22/2022]
Abstract
Muscular dystrophy patients often show cognitive impairment, in addition to muscle degeneration caused by dystrophin gene defects. The cognitive impairments lead to speculation that the dystrophin protein family may play a key role at neuronal synapses. Dystrophin regulates the stability of selected GABA(A) receptor subtypes and alpha3-containing nicotinic acetylcholine receptors (nAChRs) at a subset of central GABAergic and peripheral sympathetic nicotinic neuron synapses. Similarly, utrophin, the autosomal homologue of dystrophin, is not required for clustering but indirectly stabilizes muscle-type nAChRs at the neuromuscular junction. We examined dystrophin and utrophin expression and localization in the avian parasympathetic ciliary ganglion (CG) to determine whether these proteins play a general role at neuronal nicotinic synapses. We have determined that full-length utrophin and dystrophin and the short dystrophin isoform Dp116 are the major isoforms expressed in the CG based on immunoblotting and immunolabeling. Unexpectedly, the cytoskeletal proteins were not detected at nicotinic synapses or in CG neurons. They are expressed in myelinating and non-myelinating Schwann cells. Further, utrophin expression developmentally precedes that of dystrophin. The proteins show partially overlapping distributions, but also differential accumulation along the surface membrane of Schwann cells adjacent to neuronal somata versus axonal processes. Our findings are consistent with reports that dystrophin protein family members function in the maintenance of cell-cell interactions and myelination by anchoring the Schwann cell surface membrane to the basal lamina. In contrast, our results differ from those in skeletal muscle and a subset of sympathetic neurons where utrophin and dystrophin localize at nicotinic synapses.
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28
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L-type Ca2+ channel function is linked to dystrophin expression in mammalian muscle. PLoS One 2008; 3:e1762. [PMID: 18516256 PMCID: PMC2408559 DOI: 10.1371/journal.pone.0001762] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2007] [Accepted: 02/08/2008] [Indexed: 11/19/2022] Open
Abstract
Background In dystrophic mdx skeletal muscle, aberrant Ca2+ homeostasis and fibre degeneration are found. The absence of dystrophin in models of Duchenne muscular dystrophy (DMD) has been connected to altered ion channel properties e.g. impaired L-type Ca2+ currents. In regenerating mdx muscle, ‘revertant’ fibres restore dystrophin expression. Their functionality involving DHPR-Ca2+-channels is elusive. Methods and Results We developed a novel ‘in-situ’ confocal immuno-fluorescence and imaging technique that allows, for the first time, quantitative subcellular dystrophin-DHPR colocalization in individual, non-fixed, muscle fibres. Tubular DHPR signals alternated with second harmonic generation signals originating from myosin. Dystrophin-DHPR colocalization was substantial in wt fibres, but diminished in most mdx fibres. Mini-dystrophin (MinD) expressing fibres successfully restored colocalization. Interestingly, in some aged mdx fibres, colocalization was similar to wt fibres. Most mdx fibres showed very weak membrane dystrophin staining and were classified ‘mdx-like’. Some mdx fibres, however, had strong ‘wt-like’ dystrophin signals and were identified as ‘revertants’. Split mdx fibres were mostly ‘mdx-like’ and are not generally ‘revertants’. Correlations between membrane dystrophin and DHPR colocalization suggest a restored putative link in ‘revertants’. Using the two-micro-electrode-voltage clamp technique, Ca2+-current amplitudes (imax) showed very similar behaviours: reduced amplitudes in most aged mdx fibres (as seen exclusively in young mdx mice) and a few mdx fibres, most likely ‘revertants’, with amplitudes similar to wt or MinD fibres. Ca2+ current activation curves were similar in ‘wt-like’ and ‘mdx-like’ aged mdx fibres and are not the cause for the differences in current amplitudes. imax amplitudes were fully restored in MinD fibres. Conclusions We present evidence for a direct/indirect DHPR-dystrophin interaction present in wt, MinD and ‘revertant’ mdx fibres but absent in remaining mdx fibres. Our imaging technique reliably detects single isolated ‘revertant’ fibres that could be used for subsequent physiological experiments to study mechanisms and therapy concepts in DMD.
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29
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Hilber K. Skeletal myocyte plasticity: basis for improved therapeutic potential? Curr Opin Pharmacol 2008; 8:327-32. [PMID: 18329336 DOI: 10.1016/j.coph.2008.01.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2007] [Revised: 01/18/2008] [Accepted: 01/25/2008] [Indexed: 12/25/2022]
Abstract
Skeletal muscle tissue exhibits a remarkable capacity to regenerate after injury and to adapt its properties in response to altered functional demands or environmental pressure. This potential renders skeletal myocytes especially attractive candidates to be used in therapeutic strategies. Besides the well-described adaptability of skeletal myocytes in terms of contractile function and metabolic profile, more recent research has revealed that the electrophysiological properties of myocytes are also subject to significant changes both under physiological conditions and in pathophysiological situations. A better understanding of skeletal myocyte plasticity, its regulation and its forced induction could improve existing therapeutic approaches and may pave the way for new therapeutic strategies.
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Affiliation(s)
- Karlheinz Hilber
- Center of Biomolecular Medicine and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Waehringerstrasse 13A, 1090 Vienna, Austria.
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30
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Reynolds JG, McCalmon SA, Donaghey JA, Naya FJ. Deregulated protein kinase A signaling and myospryn expression in muscular dystrophy. J Biol Chem 2008; 283:8070-4. [PMID: 18252718 DOI: 10.1074/jbc.c700221200] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Alterations in signaling pathway activity have been implicated in the pathogenesis of Duchenne muscular dystrophy, a degenerative muscle disease caused by a deficiency in the costameric protein dystrophin. Accordingly, the notion of the dystrophin-glycoprotein complex, and by extension the costamere, as harboring signaling components has received increased attention in recent years. The localization of most, if not all, signaling enzymes to this subcellular region relies on interactions with scaffolding proteins directly or indirectly associated with the dystrophin-glycoprotein complex. One of these scaffolds is myospryn, a large, muscle-specific protein kinase A (PKA) anchoring protein or AKAP. Previous studies have demonstrated a dysregulation of myospryn expression in human Duchenne muscular dystrophy, suggesting a connection to the pathophysiology of the disorder. Here we report that dystrophic muscle exhibits reduced PKA activity resulting, in part, from severely mislocalized myospryn and the type II regulatory subunit (RIIalpha) of PKA. Furthermore, we show that myospryn and dystrophin coimmunoprecipitate in native muscle extracts and directly interact in vitro. Our findings reveal for the first time abnormalities in the PKA signal transduction pathway and myospryn regulation in dystrophin deficiency.
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Affiliation(s)
- Joseph G Reynolds
- Department of Biology, Program in Cell and Molecular Biology, Boston University, Boston, MA 02215, USA
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31
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Vela J, Pérez-Millán MI, Becu-Villalobos D, Díaz-Torga G. Different kinases regulate activation of voltage-dependent calcium channels by depolarization in GH3 cells. Am J Physiol Cell Physiol 2007; 293:C951-9. [PMID: 17507432 DOI: 10.1152/ajpcell.00429.2006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The L-type Ca2+ channel is the primary voltage-dependent Ca2+-influx pathway in many excitable and secretory cells, and direct phosphorylation by different kinases is one of the mechanisms involved in the regulation of its activity. The aim of this study was to evaluate the participation of Ser/Thr kinases and tyrosine kinases (TKs) in depolarization-induced Ca2+ influx in the endocrine somatomammotrope cell line GH3. Intracellular Ca2+ concentration ([Ca2+]i) was measured using a spectrofluorometric method with fura 2-AM, and 12.5 mM KCl (K+) was used as a depolarization stimulus. K+ induced an abrupt spike (peak) in [Ca2+]i that was abolished in the presence of nifedipine, showing that K+ enhances [Ca2+]i, preferably activating L-type Ca2+ channels. H89, a selective PKA inhibitor, significantly reduced depolarization-induced Ca2+ mobilization in a concentration-related manner when it was applied before or after K+, and okadaic acid, an inhibitor of Ser/Thr phosphatases, which has been shown to regulate PKA-stimulated L-type Ca2+ channels, increased K+-induced Ca2+ entry. When PKC was activated by PMA, the K+-evoked peak in [Ca2+]i, as well as the plateau phase, was significantly reduced, and chelerythrine (a PKC inhibitor) potentiated the K+-induced increase in [Ca2+]i, indicating an inhibitory role of PKC in voltage-dependent Ca2+ channel (VDCC) activity. Genistein, a TK inhibitor, reduced the K+-evoked increase in [Ca2+]i, but, unexpectedly, the tyrosine phosphatase inhibitor orthovanadate reduced not only basal Ca2+ levels but, also, Ca2+ influx during the plateau phase. Both results suggest that different TKs may act differentially on VDCC activation. Activation of receptor TKs with epidermal growth factor (EGF) or vascular endothelial growth factor potentiated K+-induced Ca2+ influx, and AG-1478 (an EGF receptor inhibitor) decreased it. However, inhibition of the non-receptor TK pp60 c-Src enhanced K+-induced Ca2+ influx. The present study strongly demonstrates that a complex equilibrium among different kinases and phosphatases regulates VDCC activity in the pituitary cell line GH3: PKA and receptor TKs, such as vascular endothelial growth factor receptor and EGF receptor, enhance depolarization-induced Ca2+ influx, whereas PKC and c-Src have an inhibitory effect. These kinases modulate membrane depolarization and may therefore participate in the regulation of a plethora of intracellular processes, such as hormone secretion, gene expression, protein synthesis, and cell proliferation, in pituitary cells.
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Affiliation(s)
- Jorge Vela
- Instituto de Biología y Medicina Experimental, CONICET, V. Obligado 2490, (1428Buenos Aires, Argentina
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32
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Lipskaia L, Pinet C, Fromes Y, Hatem S, Cantaloube I, Coulombe A, Lompré AM. Mutation of delta-sarcoglycan is associated with Ca(2+) -dependent vascular remodeling in the Syrian hamster. THE AMERICAN JOURNAL OF PATHOLOGY 2007; 171:162-71. [PMID: 17591963 PMCID: PMC1941595 DOI: 10.2353/ajpath.2007.070054] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We examined whether mutation of the delta-sarcoglycan gene, which causes dilated cardiomyopathy, also alters the vascular smooth muscle cell (VSMC) phenotype and arterial function in the Syrian hamster CHF 147. Thoracic aorta media thickness showed marked variability in diseased hamsters with zones of atrophy and hypertrophied segments. CHF-147 VSMCs displayed a proliferating/"synthetic" phenotype characterized by the absence of the smooth muscle myosin heavy chain SM2, dystrophin, and Ca(2+)-handling proteins, and the presence of cyclin D1. In freshly isolated VSMCs from CHF 147 hamsters, voltage-independent basal Ca(2+) channels showed enhanced activity similar to that in proliferating wild-type (WT) cells. The transcription factor NFAT (nuclear factor of activated T cells) was spontaneously active in freshly isolated CHF 147 VSMCs, as in proliferating VSMCs from WT hamsters. Mibefradil inhibited B-type channels, NFAT activity, and VSMC proliferation. CHF 147 hamsters had abundant apoptotic cells distributed in patches along the aorta, and clusters of inactive mitochondria were observed in 25% of isolated CHF 147 cells, whereas no such clusters were seen in WT cells. In conclusion, mutation of the delta-sarcoglycan gene increases plasma membrane permeability to Ca(2+), activates the Ca(2+)-regulated transcription factor NFAT, and leads to spontaneous mitochondrial aggregation, causing abnormal VSMC proliferation and apoptosis.
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Affiliation(s)
- Larissa Lipskaia
- INSERM UMR S621, 91 bd de l'Hôpital, 75634 Paris Cedex 13, France
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33
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Ceccarini M, Grasso M, Veroni C, Gambara G, Artegiani B, Macchia G, Ramoni C, Torreri P, Mallozzi C, Petrucci TC, Macioce P. Association of Dystrobrevin and Regulatory Subunit of Protein Kinase A: A New Role for Dystrobrevin as a Scaffold for Signaling Proteins. J Mol Biol 2007; 371:1174-87. [PMID: 17610895 DOI: 10.1016/j.jmb.2007.06.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Revised: 06/06/2007] [Accepted: 06/07/2007] [Indexed: 11/15/2022]
Abstract
The dystrophin-related and -associated protein dystrobrevin is a component of the dystrophin-associated protein complex, which directly links the cytoskeleton to the extracellular matrix. It is now thought that this complex also serves as a dynamic scaffold for signaling proteins, and dystrobrevin may play a role in this context. Since dystrobrevin involvement in signaling pathways seems to be dependent on its interaction with other proteins, we sought new insights and performed a two-hybrid screen of a mouse brain cDNA library using beta-dystrobrevin, the isoform expressed in non-muscle tissues, as bait. Among the positive clones characterized after the screen, one encodes the regulatory subunit RIalpha of the cAMP-dependent protein kinase A (PKA). We confirmed the interaction by in vitro and in vivo association assays, and mapped the binding site of beta-dystrobrevin on RIalpha to the amino-terminal region encompassing the dimerization/docking domain of PKA regulatory subunit. We also found that the domain of interaction for RIalpha is contained in the amino-terminal region of beta-dystrobrevin. We obtained evidence that beta-dystrobrevin also interacts directly with RIIbeta, and that not only beta-dystrobrevin but also alpha-dystrobrevin interacts with PKA regulatory subunits. We show that both alpha and beta-dystrobrevin are specific phosphorylation substrates for PKA and that protein phosphatase 2A (PP2A) is associated with dystrobrevins. Our results suggest a new role for dystrobrevin as a scaffold protein that may play a role in different cellular processes involving PKA signaling.
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Affiliation(s)
- Marina Ceccarini
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, 00161 Roma, Italy
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34
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Cantiello HF, Montalbetti N, Li Q, Chen XZ. The Cytoskeletal Connection to Ion Channels as a Potential Mechanosensory Mechanism: Lessons from Polycystin-2 (TRPP2). CURRENT TOPICS IN MEMBRANES 2007; 59:233-96. [PMID: 25168140 DOI: 10.1016/s1063-5823(06)59010-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Mechanosensitivity of ion channels, or the ability to transfer mechanical forces into a gating mechanism of channel regulation, is split into two main working (not mutually exclusive) hypotheses. One is that elastic and/or structural changes in membrane properties act as a transducing mechanism of channel regulation. The other hypothesis involves tertiary elements, such as the cytoskeleton which, itself by dynamic interactions with the ion channel, may convey conformational changes, including those ascribed to mechanical forces. This hypothesis is supported by numerous instances of regulatory changes in channel behavior by alterations in cytoskeletal structures/interactions. However, only recently, the molecular nature of these interactions has slowly emerged. Recently, a surge of evidence has emerged to indicate that transient receptor potential (TRP) channels are key elements in the transduction of a variety of environmental signals. This chapter describes the molecular linkage and regulatory elements of polycystin-2 (PC2), a TRP-type (TRPP2) nonselective cation channel whose mutations cause autosomal dominant polycystic kidney disease (ADPKD). The chapter focuses on the involvement of cytoskeletal structures in the regulation of PC2 and discusses how these connections are the transducing mechanism of environmental signals to its channel function.
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Affiliation(s)
- Horacio F Cantiello
- Renal Unit, Massachusetts General Hospital East, Charlestown, Massachusetts 02129; Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115; Laboratorio de Canales Iónicos, Departamento de Fisicoquímica y Química Analítica, Facultad de Farmacia y Bioquímica, Buenos Aires 1113, Argentina
| | - Nicolás Montalbetti
- Laboratorio de Canales Iónicos, Departamento de Fisicoquímica y Química Analítica, Facultad de Farmacia y Bioquímica, Buenos Aires 1113, Argentina
| | - Qiang Li
- Department of Physiology, University of Alberta, Edmonton T6G 2H7, Canada
| | - Xing-Zhen Chen
- Department of Physiology, University of Alberta, Edmonton T6G 2H7, Canada
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35
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Constantin B, Sebille S, Cognard C. New insights in the regulation of calcium transfers by muscle dystrophin-based cytoskeleton: implications in DMD. J Muscle Res Cell Motil 2006; 27:375-86. [PMID: 16897576 DOI: 10.1007/s10974-006-9085-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2006] [Accepted: 06/28/2006] [Indexed: 01/18/2023]
Abstract
Calcium mishandling in Duchenne muscular dystrophy (DMD) suggested that dystrophin, a membrane-associated cytoskeleton protein, may regulate calcium-signalling cascades such as calcium entries. Calcium overload in human DMD myotubes is dependent on their contractile activity suggesting the involvement of channels being activated during contraction and/or calcium release. Forced expression of mini-dystrophin in dystrophin-deficient myotubes, reactivates appropriate sarcolemmal expression of dystrophin-associated proteins and restores normal calcium handling in the cytosol. Furthermore, the recombinant mini-dystrophin reduced the store-operated calcium influx across the sarcolemma, and the mitochondrial calcium uptake during this influx. A slow component of calcium release dependent on IP3R, as well as the production of IP3, were also reduced to normal levels by expression of mini-dystrophin. Our studies provide a new model for the convergent regulation of transmembrane calcium influx and IP3-dependent calcium release by the dystrophin-based cytoskeleton (DBC). We also suggest molecular association of such channels with DBC which may provide the scaffold for assembling a multiprotein-signalling complex that modulates the channel activity. This suggests that the loss of this molecular association could participate in the alteration of calcium homeostasis observed in DMD muscle cells.
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Affiliation(s)
- Bruno Constantin
- Institut de Physiologie et Biologie Cellulaires, CNRS, UMR-6187, University of Poitiers, 86022, Poitiers, France.
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36
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van der Plas MC, Pilgram GSK, Plomp JJ, de Jong A, Fradkin LG, Noordermeer JN. Dystrophin is required for appropriate retrograde control of neurotransmitter release at the Drosophila neuromuscular junction. J Neurosci 2006; 26:333-44. [PMID: 16399704 PMCID: PMC6674336 DOI: 10.1523/jneurosci.4069-05.2006] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Mutations in the human dystrophin gene cause the Duchenne and Becker muscular dystrophies. The Dystrophin protein provides a structural link between the muscle cytoskeleton and extracellular matrix to maintain muscle integrity. Recently, Dystrophin has also been found to act as a scaffold for several signaling molecules, but the roles of dystrophin-mediated signaling pathways remain unknown. To further our understanding of this aspect of the function of dystrophin, we have generated Drosophila mutants that lack the large dystrophin isoforms and analyzed their role in synapse function at the neuromuscular junction. In expression and rescue studies, we show that lack of the large dystrophin isoforms in the postsynaptic muscle cell leads to elevated evoked neurotransmitter release from the presynaptic apparatus. Overall synapse size, the size of the readily releasable vesicle pool as assessed with hypertonic shock, and the number of presynaptic neurotransmitter release sites (active zones) are not changed in the mutants. Short-term synaptic facilitation of evoked transmitter release is decreased in the mutants, suggesting that the absence of dystrophin results in increased probability of release. Absence of the large dystrophin isoforms does not lead to changes in muscle cell morphology or alterations in the postsynaptic electrical response to spontaneously released neurotransmitter. Therefore, postsynaptic glutamate receptor function does not appear to be affected. Our results indicate that the postsynaptically localized scaffolding protein Dystrophin is required for appropriate control of neuromuscular synaptic homeostasis.
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Affiliation(s)
- Mariska C van der Plas
- Department of Molecular and Cell Biology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands
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37
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Batchelor CL, Winder SJ. Sparks, signals and shock absorbers: how dystrophin loss causes muscular dystrophy. Trends Cell Biol 2006; 16:198-205. [PMID: 16515861 DOI: 10.1016/j.tcb.2006.02.001] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2005] [Revised: 01/17/2006] [Accepted: 02/16/2006] [Indexed: 11/20/2022]
Abstract
The dystrophin-glycoprotein complex (DGC) can be considered as a specialized adhesion complex, linking the extracellular matrix to the actin cytoskeleton, primarily in muscle cells. Mutations in several components of the DGC lead to its partial or total loss, resulting in various forms of muscular dystrophy. These typically manifest as progressive wasting diseases with loss of muscle integrity. Debate is ongoing about the precise function of the DGC: initially a strictly mechanical role was proposed but it has been suggested that there is aberrant calcium handling in muscular dystrophy and, more recently, changes in MAP kinase and GTPase signalling have been implicated in the aetiology of the disease. Here, we discuss new and interesting developments in these aspects of DGC function and attempt to rationalize the mechanical, calcium and signalling hypotheses to provide a unifying hypothesis of the underlying process of muscular dystrophy.
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Affiliation(s)
- Clare L Batchelor
- Centre for Developmental and Biomedical Genetics, Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield, UK, S10 2TN
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38
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Doran P, Dowling P, Donoghue P, Buffini M, Ohlendieck K. Reduced expression of regucalcin in young and aged mdx diaphragm indicates abnormal cytosolic calcium handling in dystrophin-deficient muscle. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2006; 1764:773-85. [PMID: 16483859 DOI: 10.1016/j.bbapap.2006.01.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2005] [Revised: 12/09/2005] [Accepted: 01/02/2006] [Indexed: 11/16/2022]
Abstract
The cytosolic Ca2+ -binding protein regucalcin is involved in intracellular signaling and present in high abundance in the liver. Here, we could show by comparative mass spectrometry-based proteomics screening of normal versus dystrophic fibres that regucalcin of 33.9 kDa and pI5.2 also exists in diaphragm muscle. Since the expression of sarcolemmal Ca2+ -leak channels and luminal Ca2+ -binding elements is altered in dystrophin-deficient muscle, we initiated this study in order to determine whether additional soluble muscle proteins involved in Ca2+ -handling are affected in muscular dystrophy. Following separation by two-dimensional gel electrophoresis, the spot pattern of the normal versus the mdx diaphragm muscle proteome was evaluated by densitometry. The expression levels of 20 major protein spots were shown to change and their identity determined by mass spectrometry. A 2-fold reduction of regucalcin in mdx diaphragm, as well as in dystrophic limb muscle and heart, was confirmed by immunoblotting in both young and aged mdx mice. The results from our proteomics analysis of dystrophic diaphragm support the concept that abnormal Ca2+ -handling is involved in x-linked muscular dystrophy. The reduction in key Ca2+ -handling proteins may result in an insufficient maintenance of Ca2+ -homeostasis and an abnormal regulation of Ca2+ -dependent enzymes resulting in disturbed intracellular signaling mechanisms in dystrophinopathies.
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Affiliation(s)
- Philip Doran
- Department of Biology, National University of Ireland, Maynooth, Co. Kildare, Ireland
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Hulme JT, Konoki K, Lin TWC, Gritsenko MA, Camp DG, Bigelow DJ, Catterall WA. Sites of proteolytic processing and noncovalent association of the distal C-terminal domain of CaV1.1 channels in skeletal muscle. Proc Natl Acad Sci U S A 2005; 102:5274-9. [PMID: 15793008 PMCID: PMC555994 DOI: 10.1073/pnas.0409885102] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In skeletal muscle cells, voltage-dependent potentiation of Ca2+ channel activity requires phosphorylation by cAMP-dependent protein kinase (PKA) anchored via an A-kinase anchoring protein (AKAP15), and the most rapid sites of phosphorylation are located in the C-terminal domain. Surprisingly, the site of interaction of the complex of PKA and AKAP15 with the alpha1-subunit of Ca(V)1.1 channels lies in the distal C terminus, which is cleaved from the remainder of the channel by in vivo proteolytic processing. Here we report that the distal C terminus is noncovalently associated with the remainder of the channel via an interaction with a site in the proximal C-terminal domain when expressed as a separate protein in mammalian nonmuscle cells. Deletion mapping of the C terminus of the alpha1-subunit using the yeast two-hybrid assay revealed that a distal C-terminal peptide containing amino acids 1802-1841 specifically interacts with a region in the proximal C terminus containing amino acid residues 1556-1612. Analysis of the purified alpha1-subunit of Ca(V)1.1 channels from skeletal muscle by saturation sequencing of the intracellular peptides by tandem mass spectrometry identified the site of proteolytic processing as alanine 1664. Our results support the conclusion that a noncovalently associated complex of the alpha1-subunit truncated at A1664 with the proteolytically cleaved distal C-terminal domain, AKAP15, and PKA is the primary physiological form of Ca(V)1.1 channels in skeletal muscle cells.
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Affiliation(s)
- Joanne T Hulme
- Department of Pharmacology, University of Washington, Mailstop 357280, Seattle, WA 98195-7280, USA
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