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Ghasemizadeh A, Christin E, Guiraud A, Couturier N, Abitbol M, Risson V, Girard E, Jagla C, Soler C, Laddada L, Sanchez C, Jaque-Fernandez FI, Jacquemond V, Thomas JL, Lanfranchi M, Courchet J, Gondin J, Schaeffer L, Gache V. MACF1 controls skeletal muscle function through the microtubule-dependent localization of extra-synaptic myonuclei and mitochondria biogenesis. eLife 2021; 10:e70490. [PMID: 34448452 PMCID: PMC8500715 DOI: 10.7554/elife.70490] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 08/10/2021] [Indexed: 01/02/2023] Open
Abstract
Skeletal muscles are composed of hundreds of multinucleated muscle fibers (myofibers) whose myonuclei are regularly positioned all along the myofiber's periphery except the few ones clustered underneath the neuromuscular junction (NMJ) at the synaptic zone. This precise myonuclei organization is altered in different types of muscle disease, including centronuclear myopathies (CNMs). However, the molecular machinery regulating myonuclei position and organization in mature myofibers remains largely unknown. Conversely, it is also unclear how peripheral myonuclei positioning is lost in the related muscle diseases. Here, we describe the microtubule-associated protein, MACF1, as an essential and evolutionary conserved regulator of myonuclei positioning and maintenance, in cultured mammalian myotubes, in Drosophila muscle, and in adult mammalian muscle using a conditional muscle-specific knockout mouse model. In vitro, we show that MACF1 controls microtubules dynamics and contributes to microtubule stabilization during myofiber's maturation. In addition, we demonstrate that MACF1 regulates the microtubules density specifically around myonuclei, and, as a consequence, governs myonuclei motion. Our in vivo studies show that MACF1 deficiency is associated with alteration of extra-synaptic myonuclei positioning and microtubules network organization, both preceding NMJ fragmentation. Accordingly, MACF1 deficiency results in reduced muscle excitability and disorganized triads, leaving voltage-activated sarcoplasmic reticulum Ca2+ release and maximal muscle force unchanged. Finally, adult MACF1-KO mice present an improved resistance to fatigue correlated with a strong increase in mitochondria biogenesis.
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Affiliation(s)
- Alireza Ghasemizadeh
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Emilie Christin
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Alexandre Guiraud
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Nathalie Couturier
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Marie Abitbol
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
- Université Marcy l’Etoile, VetAgro SupLyonFrance
| | - Valerie Risson
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Emmanuelle Girard
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Christophe Jagla
- GReD Laboratory, Clermont-Auvergne University, INSERM U1103, CNRSClermont-FerrandFrance
| | - Cedric Soler
- GReD Laboratory, Clermont-Auvergne University, INSERM U1103, CNRSClermont-FerrandFrance
| | - Lilia Laddada
- GReD Laboratory, Clermont-Auvergne University, INSERM U1103, CNRSClermont-FerrandFrance
| | - Colline Sanchez
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Francisco-Ignacio Jaque-Fernandez
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Vincent Jacquemond
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Jean-Luc Thomas
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Marine Lanfranchi
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Julien Courchet
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Julien Gondin
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Laurent Schaeffer
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Vincent Gache
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
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Wang YN, Yang WC, Li PW, Wang HB, Zhang YY, Zan LS. Myocyte enhancer factor 2A promotes proliferation and its inhibition attenuates myogenic differentiation via myozenin 2 in bovine skeletal muscle myoblast. PLoS One 2018; 13:e0196255. [PMID: 29698438 PMCID: PMC5919640 DOI: 10.1371/journal.pone.0196255] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Accepted: 04/09/2018] [Indexed: 12/18/2022] Open
Abstract
Myocyte enhancer factor 2A (MEF2A) is widely distributed in various tissues or organs and plays crucial roles in multiple biological processes. To examine the potential effects of MEF2A on skeletal muscle myoblast, the functional role of MFE2A in myoblast proliferation and differentiation was investigated. In this study, we found that the mRNA expression level of Mef2a was dramatically increased during the myogenesis of bovine skeletal muscle primary myoblast. Overexpression of MEF2A significantly promoted myoblast proliferation, while knockdown of MEF2A inhibited the proliferation and differentiation of myoblast. RT-PCR and western blot analysis revealed that this positive effect of MEF2A on the proliferation of myoblast was carried out by triggering cell cycle progression by activating CDK2 protein expression. Besides, MEF2A was found to be an important transcription factor that bound to the myozenin 2 (MyoZ2) proximal promoter and performed upstream of MyoZ2 during myoblast differentiation. This study provides the first experimental evidence that MEF2A is a positive regulator in skeletal muscle myoblast proliferation and suggests that MEF2A regulates myoblast differentiation via regulating MyoZ2.
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Affiliation(s)
- Ya-Ning Wang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
- National Beef Cattle Improvement Center in China, Yangling, Shaanxi, P. R. China
| | - Wu-Cai Yang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
- National Beef Cattle Improvement Center in China, Yangling, Shaanxi, P. R. China
| | - Pei-Wei Li
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
- National Beef Cattle Improvement Center in China, Yangling, Shaanxi, P. R. China
| | - Hong-Bao Wang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
- National Beef Cattle Improvement Center in China, Yangling, Shaanxi, P. R. China
| | - Ying-Ying Zhang
- Animal Husbandry and Veterinary Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, P. R. China
| | - Lin-Sen Zan
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
- National Beef Cattle Improvement Center in China, Yangling, Shaanxi, P. R. China
- National and Provincial Joint Engineering Research Center of Modern Cattle Biotechnology and Applications, Yangling, Shaanxi, P. R. China
- * E-mail:
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van den Bos EJ, Wagner A, Mahrholdt H, Thompson RB, Morimoto Y, Sutton BS, Judd RM, Taylor DA. Improved Efficacy of Stem Cell Labeling for Magnetic Resonance Imaging Studies by the Use of Cationic Liposomes. Cell Transplant 2017; 12:743-56. [PMID: 14653621 DOI: 10.3727/000000003108747352] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Labeling stem cells with FDA-approved superparamagnetic iron oxide particles makes it possible to track cells in vivo with magnetic resonance imaging (MRI), but high intracellular levels of iron can cause free radical formation and cytotoxicity. We hypothesized that the use of cationic liposomes would increase labeling efficiency without toxic effects. Rabbit skeletal myoblasts were labeled with iron oxide by: 1) uptake of iron oxide incorporated into cationic transfection liposomes (group I) or 2) customary endocytosis (group II). In both groups, cell proliferation and differentiation were measured and toxicity was assayed using trypan blue and ratio fluorescence microscopy with BODIPY® 581/591 C11. The effects of the intracellular iron oxide on magnetic resonance image intensities were assessed in vitro and in vivo. Both methods resulted in uptake of iron intracellularly, yielding contrast-inducing properties on MRI images. In group II, however, incubation with iron oxide at high concentrations required for endocytosis caused generation of free radicals, a decrease in proliferation, and cell death. Cytotoxic effects in the remaining cells were still visible 24 h after incubation. Conversely, in group I, sufficient intracellular uptake for detection in vivo by MRI could be achieved at 100-fold lower concentrations of iron oxide, which resulted in a high percentage of labeled cells, high retention of the label, and no cytotoxic effects even after stressing the cells with a hypoxia–reoxygenation insult. The use of cationic liposomes for iron oxide stem cell labeling increases labeling efficiency approximately 100-fold without toxic effects. This technique results in high-contrast-inducing properties on MRI images both in vitro and in vivo and could thus be a valuable tool for tracking stem cells noninvasively.
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Affiliation(s)
- Ewout J van den Bos
- Division of Cardiology, Duke University Medical Center, Durham, NC 27710, USA
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Lesmana R, Sinha RA, Singh BK, Zhou J, Ohba K, Wu Y, Yau WWY, Bay BH, Yen PM. Thyroid Hormone Stimulation of Autophagy Is Essential for Mitochondrial Biogenesis and Activity in Skeletal Muscle. Endocrinology 2016; 157:23-38. [PMID: 26562261 DOI: 10.1210/en.2015-1632] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Thyroid hormone (TH) and autophagy share similar functions in regulating skeletal muscle growth, regeneration, and differentiation. Although TH recently has been shown to increase autophagy in liver, the regulation and role of autophagy by this hormone in skeletal muscle is not known. Here, using both in vitro and in vivo models, we demonstrated that TH induces autophagy in a dose- and time-dependent manner in skeletal muscle. TH induction of autophagy involved reactive oxygen species (ROS) stimulation of 5'adenosine monophosphate-activated protein kinase (AMPK)-Mammalian target of rapamycin (mTOR)-Unc-51-like kinase 1 (Ulk1) signaling. TH also increased mRNA and protein expression of key autophagy genes, microtubule-associated protein light chain 3 (LC3), Sequestosome 1 (p62), and Ulk1, as well as genes that modulated autophagy and Forkhead box O (FOXO) 1/3a. TH increased mitochondrial protein synthesis and number as well as basal mitochondrial O2 consumption, ATP turnover, and maximal respiratory capacity. Surprisingly, mitochondrial activity and biogenesis were blunted when autophagy was blocked in muscle cells by Autophagy-related gene (Atg)5 short hairpin RNA (shRNA). Induction of ROS and 5'adenosine monophosphate-activated protein kinase (AMPK) by TH played a significant role in the up-regulation of Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1A), the key regulator of mitochondrial synthesis. In summary, our findings showed that TH-mediated autophagy was essential for stimulation of mitochondrial biogenesis and activity in skeletal muscle. Moreover, autophagy and mitochondrial biogenesis were coupled in skeletal muscle via TH induction of mitochondrial activity and ROS generation.
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MESH Headings
- AMP-Activated Protein Kinases/chemistry
- AMP-Activated Protein Kinases/metabolism
- Animals
- Autophagy/drug effects
- Autophagy-Related Protein 5
- Autophagy-Related Protein-1 Homolog
- Cell Line
- Gene Expression Regulation/drug effects
- Kinetics
- Male
- Mice, Inbred C57BL
- Microtubule-Associated Proteins/antagonists & inhibitors
- Microtubule-Associated Proteins/genetics
- Microtubule-Associated Proteins/metabolism
- Mitochondria, Muscle/drug effects
- Mitochondria, Muscle/metabolism
- Mitochondria, Muscle/ultrastructure
- Mitochondrial Dynamics/drug effects
- Muscle, Skeletal/cytology
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/ultrastructure
- Myoblasts, Skeletal/cytology
- Myoblasts, Skeletal/drug effects
- Myoblasts, Skeletal/metabolism
- Myoblasts, Skeletal/ultrastructure
- Oxygen Consumption/drug effects
- Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha
- Protein Serine-Threonine Kinases/chemistry
- Protein Serine-Threonine Kinases/metabolism
- RNA Interference
- Reactive Oxygen Species/agonists
- Reactive Oxygen Species/metabolism
- Signal Transduction/drug effects
- TOR Serine-Threonine Kinases/antagonists & inhibitors
- TOR Serine-Threonine Kinases/metabolism
- Thyroxine/metabolism
- Thyroxine/pharmacology
- Transcription Factors/agonists
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Triiodothyronine/metabolism
- Triiodothyronine/pharmacology
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Affiliation(s)
- Ronny Lesmana
- Laboratory of Hormonal Regulation (R.L., R.A.S., B.K.S., J.Z., K.O., W.WY.Y., P.M.Y.), Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Graduate Medical School, Singapore 169857; Department of Physiology (R.L.), Universitas Padjadjaran, Bandung 45363, Indonesia; Department of Anatomy (Y.W., B.-H.B.), Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599; and Duke Molecular Physiology Institute and Department of Medicine (P.M.Y.), Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Rohit A Sinha
- Laboratory of Hormonal Regulation (R.L., R.A.S., B.K.S., J.Z., K.O., W.WY.Y., P.M.Y.), Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Graduate Medical School, Singapore 169857; Department of Physiology (R.L.), Universitas Padjadjaran, Bandung 45363, Indonesia; Department of Anatomy (Y.W., B.-H.B.), Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599; and Duke Molecular Physiology Institute and Department of Medicine (P.M.Y.), Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Brijesh K Singh
- Laboratory of Hormonal Regulation (R.L., R.A.S., B.K.S., J.Z., K.O., W.WY.Y., P.M.Y.), Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Graduate Medical School, Singapore 169857; Department of Physiology (R.L.), Universitas Padjadjaran, Bandung 45363, Indonesia; Department of Anatomy (Y.W., B.-H.B.), Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599; and Duke Molecular Physiology Institute and Department of Medicine (P.M.Y.), Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Jin Zhou
- Laboratory of Hormonal Regulation (R.L., R.A.S., B.K.S., J.Z., K.O., W.WY.Y., P.M.Y.), Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Graduate Medical School, Singapore 169857; Department of Physiology (R.L.), Universitas Padjadjaran, Bandung 45363, Indonesia; Department of Anatomy (Y.W., B.-H.B.), Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599; and Duke Molecular Physiology Institute and Department of Medicine (P.M.Y.), Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Kenji Ohba
- Laboratory of Hormonal Regulation (R.L., R.A.S., B.K.S., J.Z., K.O., W.WY.Y., P.M.Y.), Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Graduate Medical School, Singapore 169857; Department of Physiology (R.L.), Universitas Padjadjaran, Bandung 45363, Indonesia; Department of Anatomy (Y.W., B.-H.B.), Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599; and Duke Molecular Physiology Institute and Department of Medicine (P.M.Y.), Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Yajun Wu
- Laboratory of Hormonal Regulation (R.L., R.A.S., B.K.S., J.Z., K.O., W.WY.Y., P.M.Y.), Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Graduate Medical School, Singapore 169857; Department of Physiology (R.L.), Universitas Padjadjaran, Bandung 45363, Indonesia; Department of Anatomy (Y.W., B.-H.B.), Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599; and Duke Molecular Physiology Institute and Department of Medicine (P.M.Y.), Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Winifred W Y Yau
- Laboratory of Hormonal Regulation (R.L., R.A.S., B.K.S., J.Z., K.O., W.WY.Y., P.M.Y.), Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Graduate Medical School, Singapore 169857; Department of Physiology (R.L.), Universitas Padjadjaran, Bandung 45363, Indonesia; Department of Anatomy (Y.W., B.-H.B.), Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599; and Duke Molecular Physiology Institute and Department of Medicine (P.M.Y.), Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Boon-Huat Bay
- Laboratory of Hormonal Regulation (R.L., R.A.S., B.K.S., J.Z., K.O., W.WY.Y., P.M.Y.), Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Graduate Medical School, Singapore 169857; Department of Physiology (R.L.), Universitas Padjadjaran, Bandung 45363, Indonesia; Department of Anatomy (Y.W., B.-H.B.), Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599; and Duke Molecular Physiology Institute and Department of Medicine (P.M.Y.), Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Paul M Yen
- Laboratory of Hormonal Regulation (R.L., R.A.S., B.K.S., J.Z., K.O., W.WY.Y., P.M.Y.), Program of Cardiovascular and Metabolic Disorders, Duke-National University of Singapore Graduate Medical School, Singapore 169857; Department of Physiology (R.L.), Universitas Padjadjaran, Bandung 45363, Indonesia; Department of Anatomy (Y.W., B.-H.B.), Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599; and Duke Molecular Physiology Institute and Department of Medicine (P.M.Y.), Duke University Medical Center, Durham, North Carolina 27710, USA
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Abstract
Myoblasts aggregate, differentiate and fuse to form skeletal muscle during both embryogenesis and tissue regeneration. For proper muscle function, long-range self-organization of myoblasts is required to create organized muscle architecture globally aligned to neighboring tissue. However, how the cells process geometric information over distances considerably longer than individual cells to self-organize into well-ordered, aligned and multinucleated myofibers remains a central question in developmental biology and regenerative medicine. Using plasma lithography micropatterning to create spatial cues for cell guidance, we show a physical mechanism by which orientation information can propagate for a long distance from a geometric boundary to guide development of muscle tissue. This long-range alignment occurs only in differentiating myoblasts, but not in non-fusing myoblasts perturbed by microfluidic disturbances or other non-fusing cell types. Computational cellular automata analysis of the spatiotemporal evolution of the self-organization process reveals that myogenic fusion in conjunction with rotational inertia functions in a self-reinforcing manner to enhance long-range propagation of alignment information. With this autocatalytic alignment feedback, well-ordered alignment of muscle could reinforce existing orientations and help promote proper arrangement with neighboring tissue and overall organization. Such physical self-enhancement might represent a fundamental mechanism for long-range pattern formation during tissue morphogenesis.
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Affiliation(s)
- Michael Junkin
- Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, AZ 85721USA
| | - Siu Ling Leung
- Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, AZ 85721USA
| | - Samantha Whitman
- Department of Cell Biology and Anatomy, University of Arizona, Tucson, AZ 85721USA
| | - Carol C. Gregorio
- Department of Cell Biology and Anatomy, University of Arizona, Tucson, AZ 85721USA
| | - Pak Kin Wong
- Department of Aerospace and Mechanical Engineering, University of Arizona, Tucson, AZ 85721USA
- Biomedical Engineering IDP and BIO5 Institute, University of Arizona, Tucson, AZ 85721USA
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Salova AV, Leont'eva EA, Mozhenok TP, Kornilova ES, Krolenko SA, Beliaeva TN. [Change in localization of cellular vesicular apparatus during differentiation of myoblasts into myotubules in cell culture]. Tsitologiia 2011; 53:227-234. [PMID: 21598685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The study of changes in the intracellular processes during differentiation of myoblasts into myotubules is of great importance for understanding several fundamental problems of cell biology. At first, this concerns the spatial organization of vacuolar apparatus that reflects the alterations in the properties of cell membranes, cytoskeleton elements and dynamics of vesicular transport in the course of differentiation. The distribution of acidic membrane organelles (lysosomes, late endosomes, Golgi cisternae) during the myotubule formation was revealed. It was shown that perinuclear localization of acidic organelles in myoblasts was replaced by diffuse distribution of these structures in the whole volume of myotubules. Using lipophilic fluorescent dyes, RH 414 and di-8-ANEPPS, the process of formation and dynamics of endocytic vesicles in myoblasts and myotubules was investigated. In the present work, semiconductive nanocrystals, quantum dots (QDs), conjugated with TAT-peptide, which belongs to cell-penetrating peptides, were used to characterize nonspecific endocytosis. It was shown that QDs--TAT complexes penetrate myoblasts but do not penetrate myotubules even after 24 h incubation, which might be connected with plasma membrane changes during the process of skeletal muscle differentiation.
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Sirmenis R, Kraniauskas A, Jarašienė R, Baltriukienė D, Kalvelytė A, Bukelskienė V. Recovery of infarcted myocardium in an in vivo experiment. Medicina (Kaunas) 2011; 47:607-615. [PMID: 22286576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
UNLABELLED Acute myocardial infarction leads to the loss of functional cardiomyocytes and structural integrity. The adult heart cannot repair the damaged tissue due to inability of mature cardiomyocytes to divide and lack of stem cells. The aim of this study was to evaluate the efficiency of introduced autologous skeletal musclederived stem cells to recover the function of acutely infarcted rabbit heart in the early postoperative period. MATERIAL AND METHODS As a model for myocardium restoration in vivo, experimental rabbit heart infarct was used. Autologic adult myogenic stem cells were isolated from skeletal muscle and propagated in culture. Before transplantation, the cells were labeled with 4',6-diamidino-2-phenylindole and then, during heart surgery, introduced into the rabbit acutely infarcted myocardium. Postoperative cardiac function was monitored by recording electrocardiograms and echocardiograms. At the end of the experiment, the efficiency of cell integration was evaluated histologically. RESULTS Rabbit cardiac function recovered after 1 month after the induction of experimental infarction both in the control and experimental groups. Therefore, the first month after the infarction was the most significant for the assessment of cell transplantation efficacy. Transplanted cell integration into infarcted myocardium was time- and individual-dependent. Evaluation of changes in left ventricular ejection fraction after the induction of myocardial infarction revealed better recovery in the experimental group; however, the difference among animals in the experimental and control groups varied and was not significant. CONCLUSIONS. Autologous myogenic stem cells repopulated infarcted myocardium with different efficiency in each individual. This variability may account for the observed difference in postoperative cardiac recovery in a rabbit model.
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Affiliation(s)
- Raimondas Sirmenis
- Institute of Biochemistry, Vilnius University, Mokslininkų 12, 08662 Vilnius, Lithuania
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8
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Matzno S, Yasuda S, Juman S, Yamamoto Y, Nagareya-Ishida N, Tazuya-Murayama K, Nakabayashi T, Matsuyama K. Statin-induced apoptosis linked with membrane farnesylated Ras small G protein depletion, rather than geranylated Rho protein. J Pharm Pharmacol 2010; 57:1475-84. [PMID: 16259781 DOI: 10.1211/jpp.57.11.0014] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Abstract
Rhabdomyolysis is a severe adverse effect of 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins). This myopathy is strongly enhanced by the combination with statins and fibrates, another hypolipidaemic agent. We have evaluated the initial step of statin-induced apoptosis by the detection of membrane flip-flop using flow cytometric analysis. L6 rat myoblasts were treated with various statins (atorvastatin (3 μm), cerivastatin (3 μm), fluvastatin (3 μm), pravastatin (3 mm), or simvastatin (3 μm)) for 2, 4 or 6 h followed by reacting with FITC-conjugated annexin V for the detection of initial apoptosis signal (flip-flop). Various statin-treated myoblasts were significantly stained with FITC-annexin V at 6 h, whereas they were not detected at 2 h. Moreover, immunoblot analysis indicated that when the cells were treated with cerivastatin (3 μm), membrane-associated Ras protein was activated and detached until 6 h, resulting in cell death through the consequent activation of caspase-8. On the other hand, since cytosolic Ras activation did not activate, there is still an unknown mechanism in statin-related Ras depletion. In conclusion, statin-induced apoptosis in muscular tissue was directly initiated by the farnesyl-anchored Ras protein depletion from cell membrane with subsequent apoptosis.
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Affiliation(s)
- Sumio Matzno
- School of Pharmaceutical Sciences, Mukogawa Women's University, 11-68, Kyuban-cho, Koshien, Nishinomiya, Hyogo 663-8179, Japan.
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Evangelisti C, Riccio M, Faenza I, Zini N, Hozumi Y, Goto K, Cocco L, Martelli AM. Subnuclear localization and differentiation-dependent increased expression of DGK-zeta in C2C12 mouse myoblasts. J Cell Physiol 2006; 209:370-8. [PMID: 16897754 DOI: 10.1002/jcp.20744] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Diacylglycerol kinases (DGKs) catalyze phosphorylation of diacylglycerol (DG) to yield phosphatidic acid (PA). Previous evidence has shown that the nucleus contains several DGK isoforms. In this study, we have analyzed the expression and subnuclear localization of DGK-zeta employing C2C12 mouse myoblasts. Immunocytochemistry coupled to confocal laser scanning microscopy showed that both endogenous and green fluorescent protein-tagged overexpressed DGK-zeta localized mostly to the nucleus. In contrast, overexpressed DGK-alpha, -beta, -delta, and -iota did not migrate to the nucleus. DGK-zeta was present in the nuclear speckle domains, as also revealed by immuno-electron microscopy analysis. Moreover, DGK-zeta co-localized and interacted with phosphoinositide-specific phospholipase Cbeta1 (PLCbeta1), that is involved in inositide-dependent signaling pathways important for the regulation of cell proliferation and differentiation. Furthermore, we report that DGK-zeta associated with nuclear matrix, the fundamental organizing principle of the nucleus where many cell functions take place, including DNA replication, gene expression, and protein phosphorylation. Nuclear DGK-zeta increased during myogenic differentiation of C2C12 cells, while DGK-zeta down-regulation by siRNA markedly impaired differentiation. Overall, our findings further support the importance of speckles and nuclear matrix in lipid-dependent signaling and suggest that nuclear DGK-zeta might play some fundamental role during myogenic differentiation of C2C12 cells.
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Affiliation(s)
- Camilla Evangelisti
- Dipartimento di Scienze Anatomiche Umane e Fisiopatologia dell'Apparato Locomotore, Sezione di Anatomia, Università di Bologna, Bologna, Italy
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10
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Abstract
Bcl-2-associated athanogene 3 (BAG3) is a member of a conserved family of cyto-protective proteins that bind to and regulate Hsp70 family molecular chaperones. Here, we show that BAG3 is prominently expressed in striated muscle and colocalizes with Z-disks. Mice with homozygous disruption of the bag3 gene developed normally but deteriorated postnatally with stunted growth evident by 1 to 2 weeks of age and death by 4 weeks. BAG3-deficient animals developed a fulminant myopathy characterized by noninflammatory myofibrillar degeneration with apoptotic features. Knockdown of bag3 expression in cultured C2C12 myoblasts increased apoptosis on induction of differentiation, suggesting a need for bag3 for maintenance of myotube survival and confirming a cell autonomous role for bag3 in muscle. We conclude that although BAG3 is not required for muscle development, this co-chaperone appears to be critically important for maintenance of mature skeletal muscle.
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Affiliation(s)
- Sachiko Homma
- Burnham Institute for Medical Research, La Jolla, CA, USA
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11
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Kreisköther N, Reichert N, Buttgereit D, Hertenstein A, Fischbach KF, Renkawitz-Pohl R. Drosophila Rolling pebbles colocalises and putatively interacts with alpha-Actinin and the Sls isoform Zormin in the Z-discs of the sarcomere and with Dumbfounded/Kirre, alpha-Actinin and Zormin in the terminal Z-discs. J Muscle Res Cell Motil 2006; 27:93-106. [PMID: 16699917 DOI: 10.1007/s10974-006-9060-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2005] [Accepted: 02/14/2006] [Indexed: 10/24/2022]
Abstract
The rolling pebbles gene of Drosophila encodes two proteins, one of which, Rols7, is essential for myoblast fusion. In addition, Rols 7 is expressed during myofibrillogenesis and in the mature muscles. Here it overlaps with alpha-Actinin (alpha-Actn) and the N-terminus of D-Titin/Kettin/Zormin in the Z-line of the sarcomeres. In the attachment sites of the somatic muscles, Rols7 and the immunoglobulin superfamily protein Dumbfounded/Kin of irreC (Duf/Kirre) colocalise. As Duf/Kirre is detectable only transiently, it may be involved in establishing the first contact of the outgrowing muscle fiber to the epidermal attachment site. We propose that Rols7 and Duf/Kirre link the terminal Z-disc to the cell membrane by direct interaction. This is supported by the fact that in yeast two hybrid assays the tetratricopeptide repeat E (TPR E) of Rols7 shows interaction with the intracellular domain of Duf/Kirre. The colocalisation of Rols7 with alpha-Actn and with D-Titin/Kettin/Zormin in the Z-dics is reflected in interactions with different domains of Rols7 in this assay. In summary, these data show that besides the role in myoblast fusion, Rols7 is a scaffold protein during myofibrillogenesis and in the Z-line of the sarcomere as well as in the terminal Z-disc linking the muscle to the epidermal attachment sites.
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Affiliation(s)
- Nina Kreisköther
- Fachbereich Biologie, Entwicklungsbiologie, Philipps-Universität Marburg, Karl-von-Frisch-Str. 8, 35043 Marburg, Germany
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12
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Abstract
The real promise of a stem cell-based approach for cardiac regeneration and repair lies in the promotion of myogenesis and angiogenesis at the site of the cell graft to achieve both structural and functional benefits. Despite all of the progress and promise in this field, many unanswered questions remain; the answers to these questions will provide the much-needed breakthrough to harness the real benefits of cell therapy for the heart in the clinical perspective. One of the major issues is the choice of donor cell type for transplantation. Multiple cell types with varying potentials have been assessed for their ability to repopulate the infarcted myocardium; however, only the adult stem cells, that is, skeletal myoblasts (SkM) and bone marrow-derived stem cells (BMC), have been translated from the laboratory bench to clinical use. Which of these two cell types will provide the best option for clinical application in heart cell therapy remains arguable. With results pouring in from the long-term follow-ups of previously conducted phase I clinical studies, and with the onset of phase II clinical trials involving larger population of patients, transplantation of stem cells as a sole therapy without an adjunct conventional revascularization procedure will provide a deeper insight into the effectiveness of this approach. The present article discusses the pros and cons of using SkM and BMC individually or in combination for cardiac repair, and critically analyzes the progress made with each cell type.
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Affiliation(s)
- Lei Ye
- National University Medical Institute, National University of Singapore, Singapore 117597
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13
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Brero A, Easwaran HP, Nowak D, Grunewald I, Cremer T, Leonhardt H, Cardoso MC. Methyl CpG-binding proteins induce large-scale chromatin reorganization during terminal differentiation. ACTA ACUST UNITED AC 2005; 169:733-43. [PMID: 15939760 PMCID: PMC2171616 DOI: 10.1083/jcb.200502062] [Citation(s) in RCA: 183] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Pericentric heterochromatin plays an important role in epigenetic gene regulation. We show that pericentric heterochromatin aggregates during myogenic differentiation. This clustering leads to the formation of large chromocenters and correlates with increased levels of the methyl CpG–binding protein MeCP2 and pericentric DNA methylation. Ectopic expression of fluorescently tagged MeCP2 mimicked this effect, causing a dose-dependent clustering of chromocenters in the absence of differentiation. MeCP2-induced rearrangement of heterochromatin occurred throughout interphase, did not depend on the H3K9 histone methylation pathway, and required the methyl CpG–binding domain (MBD) only. Similar to MeCP2, another methyl CpG–binding protein, MBD2, also increased during myogenic differentiation and could induce clustering of pericentric regions, arguing for functional redundancy. This MeCP2- and MBD2-mediated chromatin reorganization may thus represent a molecular link between nuclear genome topology and the epigenetic maintenance of cellular differentiation.
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MESH Headings
- Animals
- Cell Differentiation/genetics
- Cells, Cultured
- Chromosomal Proteins, Non-Histone/genetics
- Chromosomal Proteins, Non-Histone/metabolism
- DNA Methylation
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- Epigenesis, Genetic/genetics
- Gene Expression Regulation, Developmental/genetics
- Heterochromatin/genetics
- Heterochromatin/metabolism
- Heterochromatin/ultrastructure
- Histones/genetics
- Histones/metabolism
- Male
- Methyl-CpG-Binding Protein 2
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Muscle, Skeletal/embryology
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/ultrastructure
- Myoblasts, Skeletal/metabolism
- Myoblasts, Skeletal/ultrastructure
- Protein Structure, Tertiary/genetics
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/metabolism
- Repressor Proteins/genetics
- Repressor Proteins/metabolism
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Affiliation(s)
- Alessandro Brero
- Department of Biology II, Ludwig Maximilians University Munich, 82152 Planegg-Martinsried, Germany
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14
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Nixon SJ, Wegner J, Ferguson C, Méry PF, Hancock JF, Currie PD, Key B, Westerfield M, Parton RG. Zebrafish as a model for caveolin-associated muscle disease; caveolin-3 is required for myofibril organization and muscle cell patterning. Hum Mol Genet 2005; 14:1727-43. [PMID: 15888488 DOI: 10.1093/hmg/ddi179] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Caveolae are an abundant feature of many animal cells. However, the exact function of caveolae remains unclear. We have used the zebrafish, Danio rerio, as a system to understand caveolae function focusing on the muscle-specific caveolar protein, caveolin-3 (Cav3). We have identified caveolin-1 (alpha and beta), caveolin-2 and Cav3 in the zebrafish. Zebrafish Cav3 has 72% identity to human CAV3, and the amino acids altered in human muscle diseases are conserved in the zebrafish protein. During embryonic development, cav3 expression is apparent by early segmentation stages in the first differentiating muscle precursors, the adaxial cells and slightly later in the notochord. cav3 expression appears in the somites during mid-segmentation stages and then later in the pectoral fins and facial muscles. Cav3 and caveolae are located along the entire sarcolemma of late stage embryonic muscle fibers, whereas beta-dystroglycan is restricted to the muscle fiber ends. Down-regulation of Cav3 expression causes gross muscle abnormalities and uncoordinated movement. Ultrastructural analysis of isolated muscle fibers reveals defects in myoblast fusion and disorganized myofibril and membrane systems. Expression of the zebrafish equivalent to a human muscular dystrophy mutant, CAV3P104L, causes severe disruption of muscle differentiation. In addition, knockdown of Cav3 resulted in a dramatic up-regulation of eng1a expression resulting in an increase in the number of muscle pioneer-like cells adjacent to the notochord. These studies provide new insights into the role of Cav3 in muscle development and demonstrate its requirement for correct intracellular organization and myoblast fusion.
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Affiliation(s)
- Susan J Nixon
- Institute for Molecular Bioscience, Universitky of Queensland, Brisbane 4072, Australia
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15
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Cheema U, Brown R, Mudera V, Yang SY, McGrouther G, Goldspink G. Mechanical signals and IGF-I gene splicing in vitro in relation to development of skeletal muscle. J Cell Physiol 2005; 202:67-75. [PMID: 15389530 DOI: 10.1002/jcp.20107] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
It has been shown that the insulin-like growth factor (IGF-I) gene is spliced in response to mechanical signals producing forms of IGF-I which have different actions. In order to study how mechanical signals influence this gene splicing in developing muscle, C2C12 cells were grown in three-dimensional (3D) culture and subjected to different regimens of mechanical strain. IGF-IEa which initiates the fusion of myoblasts to form myotubes was found to be constitutively expressed in myoblasts and myotubes (held under endogenous tension) and its expression upregulated by a single ramp stretch of 1-h duration but reduced by repeated cyclical stretch. In contrast, mechano growth factor (MGF), which is involved in the proliferation of mononucleated myoblasts that are required for secondary myotube formation and to establish the muscle satellite (stem) cell pool, showed no significant constitutive expression in static cultures, but was upregulated by a single ramp stretch and by cycling loading. The latter types of force simulate those generated in myoblasts by the first contractions of myotubes. These data indicate the importance of seeking to understand the physiological signals that determine the ratios of splice variants of some growth factor/tissue factor genes in the early stages of development of skeletal muscle.
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MESH Headings
- Alternative Splicing/genetics
- Animals
- Cell Differentiation/genetics
- Cell Line
- Insulin-Like Growth Factor I/genetics
- Mechanotransduction, Cellular/genetics
- Mice
- Microscopy, Electron, Transmission
- Muscle Fibers, Skeletal/metabolism
- Muscle Fibers, Skeletal/ultrastructure
- Muscle, Skeletal/growth & development
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/ultrastructure
- Myoblasts, Skeletal/metabolism
- Myoblasts, Skeletal/ultrastructure
- Protein Isoforms/genetics
- Satellite Cells, Skeletal Muscle/metabolism
- Stress, Mechanical
- Up-Regulation/physiology
- Weight-Bearing/physiology
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Affiliation(s)
- Umber Cheema
- Institute of Orthopaedics and Musculo-skeletal Science, University College London, Middlesex, United Kingdom
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16
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Formigli L, Francini F, Tani A, Squecco R, Nosi D, Polidori L, Nistri S, Chiappini L, Cesati V, Pacini A, Perna AM, Orlandini GE, Zecchi Orlandini S, Bani D. Morphofunctional integration between skeletal myoblasts and adult cardiomyocytes in coculture is favored by direct cell-cell contacts and relaxin treatment. Am J Physiol Cell Physiol 2004; 288:C795-804. [PMID: 15537709 DOI: 10.1152/ajpcell.00345.2004] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The success of cellular cardiomyoplasty, a novel therapy for the repair of postischemic myocardium, depends on the anatomical integration of the engrafted cells with the resident cardiomyocytes. Our aim was to investigate the interaction between undifferentiated mouse skeletal myoblasts (C2C12 cells) and adult rat ventricular cardiomyocytes in an in vitro coculture model. Connexin43 (Cx43) expression, Lucifer yellow microinjection, Ca2+ transient propagation, and electrophysiological analysis demonstrated that myoblasts and cardiomyocytes were coupled by functional gap junctions. We also showed that cardiomyocytes upregulated gap junctional communication and expression of Cx43 in myoblasts. This effect required direct cell-to-cell contact between the two cell types and was potentiated by treatment with relaxin, a cardiotropic hormone with potential effects on cardiac development. Analysis of the gating properties of gap junctions by dual cell patch clamping showed that the copresence of cardiomyocytes in the cultures significantly increased the transjunctional current and conductance between myoblasts. Relaxin enhanced this effect in both the myoblast-myoblast and myoblast-cardiomyocyte cell pairs, likely acting not only on gap junction formation but also on the electrical properties of the preexisting channels. Our findings suggest that myoblasts and cardiomyocytes interact actively through gap junctions and that relaxin potentiates the intercellular coupling. A potential role for gap junctional communication in favoring the intercellular exchange of regulatory molecules, including Ca2+, in the modulation of myoblast differentiation is discussed.
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Affiliation(s)
- Lucia Formigli
- Dept. of Anatomy, Univ. of Florence, Viale Morgagni 85, I-50134 Florence, Italy.
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17
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Benchaouir R, Rameau P, Decraene C, Dreyfus P, Israeli D, Piétu G, Danos O, Garcia L. Evidence for a resident subset of cells with SP phenotype in the C2C12 myogenic line: a tool to explore muscle stem cell biology. Exp Cell Res 2004; 294:254-68. [PMID: 14980519 DOI: 10.1016/j.yexcr.2003.11.005] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2003] [Revised: 11/06/2003] [Indexed: 11/28/2022]
Abstract
Muscle satellite cells are heterogeneous and present functional disparities, some of them behaving as multipotent stem cells. Yet their phenotype is obscure and their isolation remains elusive. The ability to purify stem cells from a wide variety of tissues by using Hoechst 33342 staining/FACS methods has permitted access to this category of cells (side population, or SP) in a manner independent of antibodies. Here, we show that the C2C12 myogenic line comprises a minor population of cells with SP phenotype. These cells are growth-arrested and delayed in their ability to differentiate. Dye efflux in C2C12-derived SPs is likely mediated by mdr1a, whose overexpression results in increased dedifferentiation. Interestingly, growth-arrested SPs rapidly appear in purified MP populations, thus suggesting a dynamic equilibrium among different states of differentiation. Finally, transcriptional profiling of C2C12-derived SP and MP cells corroborates the many similarities of SP to stem cells.
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Affiliation(s)
- Rachid Benchaouir
- Genethon-Centre National de la Recherche Scientifique, UMR 8115, 91002 Evry cedex, France
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18
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Abstract
In organisms from Drosophila to mammals, the musculature is comprised of an elaborate array of distinct fibers that are generated by the fusion of committed myoblasts. These muscle fibers differ from each other in features that include location, pattern of innervation, site of attachment, and size. The sizes of the newly formed muscles of an embryo are controlled in large part by the number of cells that form the syncitial fiber. Over the past few decades, an extensive body of literature has described the process of myoblast fusion in vertebrates, relying primarily on the strengths of tissue culture model systems. More recently, genetic studies in Drosophila embryos have provided new insights into the process. Together, these studies define the steps necessary for myoblast differentiation, the acquisition of fusion competence, the recognition and adhesion between myoblasts, and the fusion of two lipid bilayers into one. In this review, we have attempted to combine insights from both Drosophila and vertebrate studies to trace the processes and molecules involved in myoblast fusion. Implicit in this approach is the assumption that fundamental aspects of myoblast fusion will be similar, independent of the organism in which it is occurring.
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MESH Headings
- Animals
- Cell Adhesion/physiology
- Cell Differentiation/physiology
- Cell Membrane/metabolism
- Drosophila melanogaster/embryology
- Drosophila melanogaster/metabolism
- Drosophila melanogaster/ultrastructure
- Embryo, Nonmammalian/embryology
- Embryo, Nonmammalian/metabolism
- Embryo, Nonmammalian/ultrastructure
- Humans
- Membrane Fusion/physiology
- Muscle Fibers, Skeletal/metabolism
- Muscle Fibers, Skeletal/ultrastructure
- Muscle, Skeletal/embryology
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/ultrastructure
- Myoblasts, Skeletal/metabolism
- Myoblasts, Skeletal/ultrastructure
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Affiliation(s)
- Susan M Abmayr
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
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19
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Clarke MS, Vanderburg CR, Feeback DL. The effect of acute microgravity on mechanically-induced membrane damage and membrane-membrane fusion events. J Gravit Physiol 2001; 8:37-47. [PMID: 12365449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
Although it is unclear how a living cell senses gravitational forces there is no doubt that perturbation of the gravitational environment results in profound alterations in cellular function. In the present study, we have focused our attention on how acute microgravity exposure during parabolic flight affects the skeletal muscle cell plasma membrane (i.e. sarcolemma), with specific reference to a mechanically-reactive signaling mechanism known as mechanically-induced membrane disruption or "wounding". Both membrane rupture and membrane resealing events mediated by membrane-membrane fusion characterize this response. We here present experimental evidence that acute microgravity exposure can inhibit membrane-membrane fusion events essential for the resealing of sarcolemmal wounds in individual human myoblasts. Additional evidence to support this contention comes from experimental studies that demonstrate acute microgravity exposure also inhibits secretagogue-stimulated intracellular vesicle fusion with the plasma membrane in HL-60 cells. Based on our own observations and those of other investigators in a variety of ground-based models of membrane wounding and membrane-membrane fusion, we suggest that the disruption in the membrane resealing process observed during acute microgravity is consistent with a microgravity-induced decrease in membrane order.
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Affiliation(s)
- M S Clarke
- Division of Space Life Sciences, Universities Space Research Association, Houston, TX, USA.
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