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Machado J, Silveira WA, Gonçalves DA, Schavinski AZ, Khan MM, Zanon NM, Diaz MB, Rudolf R, Kettelhut IC, Navegantes LC. α-Calcitonin gene-related peptide inhibits autophagy and calpain systems and maintains the stability of neuromuscular junction in denervated muscles. Mol Metab 2019; 28:91-106. [PMID: 31331823 PMCID: PMC6822259 DOI: 10.1016/j.molmet.2019.06.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 06/23/2019] [Accepted: 06/28/2019] [Indexed: 11/25/2022] Open
Abstract
Objective Although it is well established that a-calcitonin gene-related peptide (CGRP) stabilizes muscle-type cholinergic receptors nicotinic subunits (AChR), the underlying mechanism by which this neuropeptide regulates muscle protein metabolism and neuromuscular junction (NMJ) morphology is unclear. Methods To elucidate the mechanisms how CGRP controls NMJ stability in denervated mice skeletal muscles, we carried out physiological, pharmacological, and molecular analyses of atrophic muscles induced by sciatic nerve transection. Results Here, we report that CGRP treatment in vivo abrogated the deleterious effects on NMJ upon denervation (DEN), an effect that was associated with suppression of skeletal muscle proteolysis, but not stimulation of protein synthesis. CGRP also blocked the DEN-induced increase in endocytic AChR vesicles and the elevation of autophagosomes per NMJ area. The treatment of denervated animals with rapamycin blocked the stimulatory effects of CGRP on mTORC1 and its inhibitory actions on autophagic flux and NMJ degeneration. Furthermore, CGRP inhibited the DEN-induced hyperactivation of Ca2+-dependent proteolysis, a degradative system that has been shown to destabilize NMJ. Consistently, calpain was found to be activated by cholinergic stimulation in myotubes leading to the dispersal of AChR clusters, an effect that was abolished by CGRP. Conclusion Taken together, these data suggest that the inhibitory effect of CGRP on autophagy and calpain may represent an important mechanism for the preservation of synapse morphology when degradative machinery is exacerbated upon denervation conditions. CGRP exerts antiproteolytic effects in atrophic denervated muscles and maintains the stability of NMJ. CGRP blocks the endocytosis of AChRs and decreases the colocalization of autophagosome to NMJ in denervated muscles. CGRP inhibits the Ca2+-dependent proteolysis, a degradative system that destabilizes NMJ during muscle atrophy. The inhibition of autophagy and calpain induced by CGRP represents an important mechanism for the preservation of synapse.
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Affiliation(s)
- Juliano Machado
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil; Department of Biochemistry/Immunology, Ribeirão Preto Medical School/University of São Paulo, Ribeirão Preto, São Paulo, Brazil; Institute for Diabetes and Cancer (IDC), Helmholtz Center Munich, 85764, Neuherberg, Germany; Joint Heidelberg-IDC Translational Diabetes Program, Inner Medicine I, Heidelberg University Hospital, 69120, Heidelberg, Germany.
| | - Wilian A Silveira
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
| | - Dawit A Gonçalves
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil; Department of Biochemistry/Immunology, Ribeirão Preto Medical School/University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
| | - Aline Zanatta Schavinski
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
| | - Muzamil M Khan
- Institute of Molecular and Cell Biology, University of Applied Sciences Mannheim, Mannheim, Germany; Institute of Medical Technology, University of Heidelberg and University of Applied Sciences Mannheim, Mannheim, Germany.
| | - Neusa M Zanon
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
| | - Mauricio Berriel Diaz
- Institute for Diabetes and Cancer (IDC), Helmholtz Center Munich, 85764, Neuherberg, Germany; Joint Heidelberg-IDC Translational Diabetes Program, Inner Medicine I, Heidelberg University Hospital, 69120, Heidelberg, Germany.
| | - Rüdiger Rudolf
- Institute of Molecular and Cell Biology, University of Applied Sciences Mannheim, Mannheim, Germany; Institute of Medical Technology, University of Heidelberg and University of Applied Sciences Mannheim, Mannheim, Germany.
| | - Isis C Kettelhut
- Department of Biochemistry/Immunology, Ribeirão Preto Medical School/University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
| | - Luiz C Navegantes
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
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Cisterna BA, Vargas AA, Puebla C, Sáez JC. Connexin hemichannels explain the ionic imbalance and lead to atrophy in denervated skeletal muscles. Biochim Biophys Acta Mol Basis Dis 2016; 1862:2168-2176. [PMID: 27580092 DOI: 10.1016/j.bbadis.2016.08.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 08/09/2016] [Accepted: 08/26/2016] [Indexed: 10/21/2022]
Abstract
Denervated fast skeletal muscles undergo atrophy, which is associated with an increase in sarcolemma permeability and protein imbalance. However, the mechanisms responsible for these alterations remain largely unknown. Recently, a close association between de novo expression of hemichannels formed by connexins 43 and 45 and increase in sarcolemma permeability of denervated fast skeletal myofibers was demonstrated. However, it remains unknown whether these connexins cause the ionic imbalance of denervates fast myofibers. To elucidate the latter and the role of hemichannels formed by connexins (Cx HCs) in denervation-induced atrophy, skeletal myofibers deficient in Cx43 and Cx45 expression (Cx43fl/flCx45fl/fl:Myo-Cre mice) and control (Cx43fl/flCx45fl/fl mice) were denervated and several muscle features were systematically analyzed at different post-denervation (PD) times (1, 3, 5, 7 and 14days). The following sequence of events was found in denervated myofibers of Cx43fl/flCx45fl/fl mice: 1) from day 3 PD, increase in sarcolemmal permeability, 2) from day 5 PD, increases of intracellular Ca2+ and Na+ signals as well as a significant increase in protein synthesis and degradation, yielding a negative protein balance and 3) from day 7 PD, a fall in myofibers cross-section area. All the above alterations were either absent or drastically reduced in denervated myofibers of Cx43fl/flCx45fl/fl:Myo-Cre mice. Thus, the denervation-induced Cx HCs expression is an early event that precedes the electrochemical gradient dysregulation across the sarcolemma and critically contributes to the progression of skeletal muscle atrophy. Consequently, Cx HCs could be a therapeutic target to drastically prevent the denervation-induced atrophy of fast skeletal muscles.
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Affiliation(s)
- Bruno A Cisterna
- Departamento de Fisiología, Pontifícia Universidad Católica de Chile, Santiago, Chile; Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile.
| | - Aníbal A Vargas
- Departamento de Fisiología, Pontifícia Universidad Católica de Chile, Santiago, Chile
| | - Carlos Puebla
- Departamento de Fisiología, Pontifícia Universidad Católica de Chile, Santiago, Chile; Centro de Fisiología Celular e Integrativa, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo, Santiago, Chile
| | - Juan C Sáez
- Departamento de Fisiología, Pontifícia Universidad Católica de Chile, Santiago, Chile; Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile.
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Wu R, Yan Y, Yao J, Liu Y, Zhao J, Liu M. Calpain 3 Expression Pattern during Gastrocnemius Muscle Atrophy and Regeneration Following Sciatic Nerve Injury in Rats. Int J Mol Sci 2015; 16:26927-35. [PMID: 26569227 PMCID: PMC4661861 DOI: 10.3390/ijms161126003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 10/30/2015] [Accepted: 11/04/2015] [Indexed: 12/11/2022] Open
Abstract
Calpain 3 (CAPN3), also known as p94, is a skeletal muscle-specific member of the calpain family that is involved in muscular dystrophy; however, the roles of CAPN3 in muscular atrophy and regeneration are yet to be understood. In the present study, we attempted to explain the effect of CAPN3 in muscle atrophy by evaluating CAPN3 expression in rat gastrocnemius muscle following reversible sciatic nerve injury. After nerve injury, the wet weight ratio and cross sectional area (CSA) of gastrocnemius muscle were decreased gradually from 1–14 days and then recovery from 14–28 days. The active form of CAPN3 (~62 kDa) protein decreased slightly on day 3 and then increased from day 7 to 14 before a decrease from day 14 to 28. The result of linear correlation analysis showed that expression of the active CAPN3 protein level was negatively correlated with muscle wet weight ratio. CAPN3 knockdown by short interfering RNA (siRNA) injection improved muscle recovery on days 7 and 14 after injury as compared to that observed with control siRNA treatment. Depletion of CAPN3 gene expression could promote myoblast differentiation in L6 cells. Based on these findings, we conclude that the expression pattern of the active CAPN3 protein is linked to muscle atrophy and regeneration following denervation: its upregulation during early stages may promote satellite cell renewal by inhibiting differentiation, whereas in later stages, CAPN3 expression may be downregulated to stimulate myogenic differentiation and enhance recovery. These results provide a novel mechanistic insight into the role of CAPN3 protein in muscle regeneration after peripheral nerve injury.
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Affiliation(s)
- Ronghua Wu
- Jiangsu Key Laboratory of Neuroregeneration, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China.
| | - Yingying Yan
- Jiangsu Key Laboratory of Neuroregeneration, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China.
| | - Jian Yao
- Department of Histology and Embryology, Medical College, Nantong University, Nantong 226001, China.
| | - Yan Liu
- Jiangsu Key Laboratory of Neuroregeneration, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China.
| | - Jianmei Zhao
- Department of Pediatrics, the Affiliated Hospital of Nantong University, Nantong 226001, China.
| | - Mei Liu
- Jiangsu Key Laboratory of Neuroregeneration, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China.
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Wei JH, Chang NC, Chen SP, Geraldine P, Jayakumar T, Fong TH. Comparative decline of the protein profiles of nebulin in response to denervation in skeletal muscle. Biochem Biophys Res Commun 2015; 466:95-102. [PMID: 26325472 DOI: 10.1016/j.bbrc.2015.08.114] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 08/25/2015] [Indexed: 11/28/2022]
Abstract
The sliding filament model of the sarcomere was developed more than half a century ago. This model, consisting only of thin and thick filaments, has been efficacious in elucidating many, but not all, features of skeletal muscle. Work during the 1980s revealed the existence of two additional filaments: the giant filamentous proteins titin and nebulin. Nebulin, a giant myofibrillar protein, acts as a protein ruler to maintain the lattice arrays of thin filaments and plays a role in signal transduction and contractile regulation. However, the change of nebulin and its effect on thin filaments in denervation-induced atrophic muscle remains unclear. The purpose of this study is to examine the content and pattern of nebulin, myosin heavy chain (MHC), actin, and titin in innervated and denervated tibialis anterior (TA) muscles of rats using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), densitometry and electron microscopic (EM) analyses. The results revealed that denervation induced muscle atrophy is accompanied by decreased nebulin content in a time-dependent manner. For instant, the levels of nebulin in denervated muscles were markedly (P < 0.05) decreased, about 24.6% and 40.2% in comparison with innervated muscle after denervation of 28 and 56 days, respectively. The nebulin/MHC, nebulin/actin, and nebulin/titin ratios were decreased, suggesting a concomitant reduction of nebulin in denervated muscle. Moreover, a western blotting assay proved that nebulin declined faster than titin on 28 and 56 days of denervated muscle. In addition, EM study revealed that the disturbed arrangements of myofilaments and a disorganized contractile apparatus were also observed in denervated muscle. Overall, the present study provides evidence that nebulin is more sensitive to the effect of denervation than MHC, actin, and titin. Nebulin decline indeed resulted in disintegrate of thin filaments and shortening of sarcomeres.
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Affiliation(s)
- Jih-Hua Wei
- Department of Internal Medicine, Min-Sheng General Hospital, Taoyuan, Taiwan
| | - Nen-Chung Chang
- Division of Cardiology, Department of Internal Medicine, College of Medicine, Taipei Medical University Hospital, Taipei, Taiwan
| | - Sy-Ping Chen
- Department of Nursing, Chang Gung University of Science and Technology, Taoyuan, Taiwan
| | - Pitchairaj Geraldine
- Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India
| | - Thanasekaran Jayakumar
- Department of Pharmacology and Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan.
| | - Tsorng-Harn Fong
- Department of Anatomy and Cell Biology, College of Medicine, Taipei Medical University, Taipei, Taiwan.
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Cea LA, Riquelme MA, Cisterna BA, Puebla C, Vega JL, Rovegno M, Sáez JC. Connexin- and pannexin-based channels in normal skeletal muscles and their possible role in muscle atrophy. J Membr Biol 2012; 245:423-36. [PMID: 22850938 DOI: 10.1007/s00232-012-9485-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Accepted: 06/28/2012] [Indexed: 12/13/2022]
Abstract
Precursor cells of skeletal muscles express connexins 39, 43 and 45 and pannexin1. In these cells, most connexins form two types of membrane channels, gap junction channels and hemichannels, whereas pannexin1 forms only hemichannels. All these channels are low-resistance pathways permeable to ions and small molecules that coordinate developmental events. During late stages of skeletal muscle differentiation, myofibers become innervated and stop expressing connexins but still express pannexin1 hemichannels that are potential pathways for the ATP release required for potentiation of the contraction response. Adult injured muscles undergo regeneration, and connexins are reexpressed and form membrane channels. In vivo, connexin reexpression occurs in undifferentiated cells that form new myofibers, favoring the healing process of injured muscle. However, differentiated myofibers maintained in culture for 48 h or treated with proinflammatory cytokines for less than 3 h also reexpress connexins and only form functional hemichannels at the cell surface. We propose that opening of these hemichannels contributes to drastic changes in electrochemical gradients, including reduction of membrane potential, increases in intracellular free Ca(2+) concentration and release of diverse metabolites (e.g., NAD(+) and ATP) to the extracellular milieu, contributing to multiple metabolic and physiologic alterations that characterize muscles undergoing atrophy in several acquired and genetic human diseases. Consequently, inhibition of connexin hemichannels expressed by injured or denervated skeletal muscles might reduce or prevent deleterious changes triggered by conditions that promote muscle atrophy.
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Affiliation(s)
- Luis A Cea
- Departamento de Fisiología, Pontificia Universidad Católica de Chile, Alameda 340, Santiago, Chile,
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Denervation causes fiber atrophy and myosin heavy chain co-expression in senescent skeletal muscle. PLoS One 2012; 7:e29082. [PMID: 22235261 PMCID: PMC3250397 DOI: 10.1371/journal.pone.0029082] [Citation(s) in RCA: 171] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Accepted: 11/21/2011] [Indexed: 01/06/2023] Open
Abstract
Although denervation has long been implicated in aging muscle, the degree to which it is causes the fiber atrophy seen in aging muscle is unknown. To address this question, we quantified motoneuron soma counts in the lumbar spinal cord using choline acetyl transferase immunhistochemistry and quantified the size of denervated versus innervated muscle fibers in the gastrocnemius muscle using the in situ expression of the denervation-specific sodium channel, Nav1.5, in young adult (YA) and senescent (SEN) rats. To gain insights into the mechanisms driving myofiber atrophy, we also examined the myofiber expression of the two primary ubiquitin ligases necessary for muscle atrophy (MAFbx, MuRF1). MN soma number in lumbar spinal cord declined 27% between YA (638±34 MNs×mm−1) and SEN (469±13 MNs×mm−1). Nav1.5 positive fibers (1548±70 μm2) were 35% smaller than Nav1.5 negative fibers (2367±78 μm2; P<0.05) in SEN muscle, whereas Nav1.5 negative fibers in SEN were only 7% smaller than fibers in YA (2553±33 μm2; P<0.05) where no Nav1.5 labeling was seen, suggesting denervation is the primary cause of aging myofiber atrophy. Nav1.5 positive fibers had higher levels of MAFbx and MuRF1 (P<0.05), consistent with involvement of the proteasome proteolytic pathway in the atrophy of denervated muscle fibers in aging muscle. In summary, our study provides the first quantitative assessment of the contribution of denervation to myofiber atrophy in aging muscle, suggesting it explains the majority of the atrophy we observed. This striking result suggests a renewed focus should be placed on denervation in seeking understanding of the causes of and treatments for aging muscle atrophy.
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Chen SP, Sheu JR, Lin ACM, Hsiao G, Fong TH. Decline in titin content in rat skeletal muscle after denervation. Muscle Nerve 2006; 32:798-807. [PMID: 16175625 DOI: 10.1002/mus.20432] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Titin, an elastic and giant myofibrillar protein, is responsible for generating passive tension and maintaining sarcomere structure in striated muscles. Several studies have reported attenuation of passive tension and disorganization of sarcomere in atrophic muscles, but the changes of titin have not been investigated after denervation. For this purpose, we used sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunofluorescent staining to examine titin in innervated and denervated tibialis anterior (TA) muscles of the rat. With increasing denervation time, we found a greater loss of titin than myosin heavy chain (MHC) and actin contents in atrophic TA muscle. The ratios of titin/MHC and titin/actin gradually decreased following denervation. In contrast, ratios of MHC/actin in the denervated groups showed no significant differences with the controls even at 56 days postdenervation. The ultrastructure of myofibrils also showed disturbed arrangements of myofilaments and a disorganized contractile apparatus in denervated muscle. Immunofluorescent staining displayed translocation of the titin epitope from the Z-line to the I-band, suggesting that the apparent cleavage of titin occurred near the Z-line region during the atrophying process. Our study provides evidence that titin is more sensitive to degradation than MHC and actin after denervation. Moreover, the titin decline results in the loss of titin-based sarcomeric integrity in atrophic muscle.
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Affiliation(s)
- Sy-Ping Chen
- Graduate Institute of Medical Sciences, Taipei Medical University, Taipei, Taiwan
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Abstract
Muscle cells grow by proliferation and protein accumulation. During the initial stages of development the participation of nerves is not always required. Myoblasts and satellite cells proliferate, fusing to form myotubes which further differentiate to muscle fibers. Myotubes and muscle fibers grow by protein accumulation and fusion with other myogenic cells. Muscle fibers finally reach a quasi-steady state which is then maintained for a long period. The mechanism of maintenance is not well understood. However, it is clear that protein metabolism plays a paramount role. The role played by satellite cells in the maintenance of muscle fibers is not known. Growth and maintenance of muscle cells are under the influence of various tissues and substances. Among them are Tf and the motor nerve, the former being the main object of this review and essential for both DNA and protein synthesis. Two sources of Tf have been proposed, i.e., the motor nerve and the tissue fluid. The first proposal is that the nervous trophic influence on muscle cells is mediated by Tf which is released from the nerve terminals. In this model, the sole source of Tf which is donated to muscle cells should be the nerve, and Tf should not be provided for muscle fiber at sites other than the synaptic region; otherwise, denervation atrophy would not occur, since Tf provided from TfR located at another site would cancel the effect of denervation. The second proposal is that Tf is provided from tissue fluid. This implies that an adequate amount of Tf is transferred from serum to tissue fluid; in this case TfR may be distributed over the entire surface of the cells. The trophic effects of the motor neuron have been studied in vivo, but its effects of myoblast proliferation have not been determined. There are few experiments on its effects on myotubes. Most work has been made on muscle fibers, where innervation is absolutely required for their maintenance. Without it, muscle fibers atrophy, although they do not degenerate. In contrast, almost all the work on Tf has been performed in vitro. Its effects on myoblast proliferation and myotube growth and maintenance have been established; myotubes degenerate following Tf removal. But its effects on mature muscle fibers in vivo are not well understood. Muscle fibers possess TfR all over on their cell surface and contain a variety of Fe-binding proteins, such as myoglobin. It is entirely plausible that muscle fibers require an amount of Tf, and that this is provided by TfR scattered on the cell surface.(ABSTRACT TRUNCATED AT 400 WORDS)
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Batt J, Bain J, Goncalves J, Michalski B, Plant P, Fahnestock M, Woodgett J. Differential gene expression profiling of short and long term denervated muscle. FASEB J 2005; 20:115-7. [PMID: 16291642 DOI: 10.1096/fj.04-3640fje] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Skeletal muscle function and viability are dependent upon intact innervation. Peripheral nerve injury and muscle denervation cause muscle atrophy. Time to re-innervation is one of the most important determinants of functional outcome. While short-term denervation can result in nearly fully reversible changes in muscle mass, prolonged denervation leads to irreversible muscle impairment from profound atrophy, myocyte death and fibrosis. We performed transcriptional profiling to identify genes that were altered in expression in short-term (1 month) and long-term (3 month) denervated muscle and validated the microarray data by RT-PCR and Western blotting. Genes controlling cell death, metabolism, proteolysis, stress responses and protein synthesis/translation were altered in expression in the denervated muscle. A differential pattern of expression of genes encoding cell cycle regulators and extracellular matrix components was identified that correlated with the development of irreversible post-denervation changes. Genes encoding mediators of protein degradation were differentially expressed between 1 and 3 month denervated muscle suggesting different signaling networks are recruited over time to induce and maintain muscle atrophy. Understanding of the timing and type of pathological processes that are triggered by denervation may allow the design of interventions that delay or protect muscle from loss of nerve function.
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Affiliation(s)
- Jane Batt
- Clinical Sciences Division, Department of Medicine, University of Toronto, Toronto, Ontario, Canada.
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Mouatt-Prigent A, Karlsson JO, Yelnik J, Agid Y, Hirsch EC. Calpastatin immunoreactivity in the monkey and human brain of control subjects and patients with Parkinson's disease. J Comp Neurol 2000; 419:175-92. [PMID: 10722997 DOI: 10.1002/(sici)1096-9861(20000403)419:2<175::aid-cne3>3.0.co;2-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Parkinson's disease is characterized by a selective loss of dopaminergic neurons in the nigrostriatal pathway. However, not all dopaminergic neurons degenerate in this disease, and calcium has been suspected of playing a role in this differential vulnerability. An overexpression of the calcium-dependent protease calpain II has recently been reported in the parkinsonian substantia nigra, suggesting that a rise in intracellular calcium concentrations may be involved in the mechanism leading to cell death. The proteasic activity of calpain is regulated by an endogenous inhibitory protein called calpastatin. Because little is known about the distribution of calpastatin in the primate brain, we first analyzed immunohistochemically the calpastatin expression in normal human and monkey brain. A ubiquitous distribution of calpastatin immunostaining was observed in both cases, but its expression was variable from one region to another. In the basal ganglia, staining was intense in the striatum, in the pallidal complex, and in some nuclei of the thalamus. The cerebellum was stained intensely, particularly in the granular and Purkinje cell layers. A dense, heterogeneous staining was observed in the hippocampal formation, mostly in the pyramidal and granular layers. The distribution of staining was similar in the different cerebral cortices studied, and it was most intense in layer V. In the brainstem, staining was particularly prominent in the substantia nigra pars reticulata and compacta, the central gray substance, the superior colliculus, and the cuneiform nucleus, and staining was moderate in the tegmenti pedonculopontinus nucleus and the griseum pontis. In the second part of the study, the authors compared calpastatin expression in the mesencephalon between patients with Parkinson's disease and control subjects. Sequential double staining revealed that some dopaminergic neurons coexpress calpastatin, the proportion of double-stained neurons ranging between 52% and 76% among the different dopaminergic cell groups. Quantitative analysis of the number of calpastatin-stained neurons evidenced a loss of both calpastatin-positive and calpastatin-negative neurons in the substantia nigra of patients with Parkinson's disease. These data suggest that calpain II overexpression in Parkinson's disease is not compensated for by a concomitant increase in calpastatin expression.
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Affiliation(s)
- A Mouatt-Prigent
- Institut National de la Santé et de la Recherche Médicale U289, Hôpital de la Salpêtrière, 75013 Paris, France
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Marzella L, Lee HK. Chapter 5 Role of lysosomes in cell injury. PRINCIPLES OF MEDICAL BIOLOGY A MULTI-VOLUME WORK, VOLUME 13 1998. [PMCID: PMC7149001 DOI: 10.1016/s1569-2582(98)80007-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Lysosomes are acidic intracellular vacuoles of heterogeneous shape, size, and content. Lysosomes contain hydrolytic enzymes that degrade proteins, lipids, carbohydrates, and nucleic acids derived from intracellular (through autophagy) and extracellular (through heterophagy) sources. Lysosomal degradation regulates several physiological cell functions. These include turnover of cellular organelles and extracellular constituents; amino acid and glucose homeostasis; processing of proteins; lipid metabolism; cell growth, differentiation, and involution; host defenses against microorganisms and other pathogens; and removal of necrotic and foreign material from the circulation and from tissues. Lysosomal degradation also plays an important role in the pathophysiology of acute and chronic cell injury, inflammation and repair, and tumor growth and metastasis. The participation of the lysosomes in the specific types of cell injury we have discussed is due to altered regulation of one or more of the following processes: turnover of cellular organelles by autophagic degradation; levels and activities of lysosomal hydrolases; levels of intracellular and extracellular lysosomal hydrolase inhibitors; transport of degradation products from the lysosomal matrix to the cytosol; permeability of the lysosomal membrane to hydrolases; lysosomal vacuolar acidification; transport of degradable substrates and of pathogens to the lysosomes; transport and processing of secretory proteins and lysosomal hydrolases during biogenesis; traffic and fusion of lysosomal vacuoles and vesicles; secretion of lysosomal hydrolases; and accumulation of metals, particularly iron, acidotropic agents, and undegraded and/or undegradable materials in lysosomes.
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Raabe TD, Nguyen T, Bittner GD. Calcium-activated proteolysis of neurofilament proteins in goldfish Mauthner axons. JOURNAL OF NEUROBIOLOGY 1995; 26:253-61. [PMID: 7707045 DOI: 10.1002/neu.480260209] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We have examined the proteolytic breakdown of neurofilament proteins (NFPs) in isolated Mauthner axoplasm (M-axoplasm). Documentation of proteolytic breakdown of NFPs in M-axoplasm is important because NFPs are not degraded in distal segments of severed Mauthner axons (M-axons) maintained in vivo for up to 62 days at 20 degrees C. By incubating M-axoplasm with 2 mM calcium in vitro, we have demonstrated that M-axoplasm contains an endogenous calcium-activated neutral protease that degrades NFPs. This calcium-activated proteolysis of M-axoplasm NFPs produced novel bands on silver-stained gels. These novel bands were presumed to be NFP breakdown products because they reacted with antibodies to the alpha-intermediate filament antigen (anti-IFA) on immunoblots from these gels. Incubations of M-axoplasm with 2 mM calcium plus exogenous calpain produced novel bands similar to those observed for M-axoplasm incubated with 2 mM calcium. Incubations of M-axoplasm with 2mM calcium plus calpain inhibitors did not produce these novel bands. These in vitro data indicate that M-axoplasm contains calpain that degrades NFPs and produces novel bands similar to those observed from distal segments of severed M-axons maintained in vivo longer than 62 days postseverance. Factors that affect the activity of calpain or affect the ability of calpain to degrade NFPs could account for the delayed degradation of NFPs in distal segments of severed M-axons maintained in vivo.
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Affiliation(s)
- T D Raabe
- Department of Zoology, University of Texas at Austin 78712-1064, USA
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Tiao G, Fagan JM, Samuels N, James JH, Hudson K, Lieberman M, Fischer JE, Hasselgren PO. Sepsis stimulates nonlysosomal, energy-dependent proteolysis and increases ubiquitin mRNA levels in rat skeletal muscle. J Clin Invest 1994; 94:2255-64. [PMID: 7989581 PMCID: PMC330052 DOI: 10.1172/jci117588] [Citation(s) in RCA: 197] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
We tested the role of different intracellular proteolytic pathways in sepsis-induced muscle proteolysis. Sepsis was induced in rats by cecal ligation and puncture; controls were sham operated. Total and myofibrillar proteolysis was determined in incubated extensor digitorum longus muscles as release of tyrosine and 3-methylhistidine, respectively. Lysosomal proteolysis was assessed by using the lysosomotropic agents NH4Cl, chloroquine, leupeptin, and methylamine. Ca(2+)-dependent proteolysis was determined in the absence or presence of Ca2+ or by blocking the Ca(2+)-dependent proteases calpain I and II. Energy-dependent proteolysis was determined in muscles depleted of ATP by 2-deoxyglucose and 2.4-dinitrophenol. Muscle ubiquitin mRNA and the concentrations of free and conjugated ubiquitin were determined by Northern and Western blots, respectively, to assess the role of the ATP-ubiquitin-dependent proteolytic pathway. Total and myofibrillar protein breakdown was increased during sepsis by 50 and 440%, respectively. Lysosomal and Ca(2+)-dependent proteolysis was similar in control and septic rats. In contrast, energy-dependent total and myofibrillar protein breakdown was increased by 172% and more than fourfold, respectively, in septic muscle. Ubiquitin mRNA was increased severalfold in septic muscle. The results suggest that the increase in muscle proteolysis during sepsis is due to an increase in nonlysosomal energy-dependent protein breakdown, which may involve the ubiquitin system.
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Affiliation(s)
- G Tiao
- Department of Surgery, University of Cincinnati, Ohio 45267
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Abstract
The activities of superoxide dismutase, catalase and glutathione reductase were not affected by in vitro incubation with the intracellular proteinase calpain, suggesting that these enzymes are not in vivo substrates of calpain. In contrast, the activity of another important antioxidant enzyme, glutathione peroxidase, is stimulated in vitro by calpain. This may explain the correlation between elevations in glutathione peroxidase activity and calpain activity which occur in aging, exercised and dystrophic muscle. Calpain treatment in vitro caused a large decrease in the activity of carnosine synthetase which is involved in the synthesis of the putative antioxidant carnosine. This may be the reason for the in vivo correlation between elevated calpain and diminished carnosine levels in aging, hypertensive, denervated and dystrophic muscles.
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Affiliation(s)
- P Johnson
- Department of Chemistry, Ohio University, Athens 45701
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Johnson P, Hammer JL. Cardiac and skeletal muscle enzyme levels in hypertensive and aging rats. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1993; 104:63-7. [PMID: 8448994 DOI: 10.1016/0305-0491(93)90338-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
1. The activities of glycolytic, fatty acid oxidation and citric acid cycle enzymes were measured in hypertensive and aging rat cardiac and skeletal muscles. 2. Lactate dehydrogenase and beta-hydroxyacyl-CoA dehydrogenase were significantly decreased in hypertensive, but not senescent, cardiac muscle. 3. Total phosphorylase activity was significantly increased in senescent, but not hypertensive, cardiac muscle. 4. In aging rat cardiac and skeletal muscles, calpain II titers increased significantly with age, but in normotensive and hypertensive muscles, the titers showed no significant difference.
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Affiliation(s)
- P Johnson
- Department of Chemistry and College of Osteopathic Medicine, Ohio University, Athens 45701
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Staron RS, Hikida RS, Murray TF, Nelson MM, Johnson P, Hagerman F. Assessment of skeletal muscle damage in successive biopsies from strength-trained and untrained men and women. EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY AND OCCUPATIONAL PHYSIOLOGY 1992; 65:258-64. [PMID: 1396656 DOI: 10.1007/bf00705091] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The effects of repeated biopsy sampling on muscle morphology was qualitatively and quantitatively assessed in strength-trained and untrained men and women. College-age men (13) and women (8) resistance trained twice a week for 8 weeks. A progressive resistance-training program was performed consisting of squats, leg presses, and leg extensions. Nontraining men (7) and women (5) served as controls. Muscle biopsy specimens and fasting bloods were obtained at the beginning and every 2 weeks and histochemical, biochemical, and ultrastructural methods were employed to assess the type and amount of damage. Except for a few scattered atrophic fibers in 2 of the 33 biopsy samples, all initial specimens were normal. In contrast, many of the subsequent biopsy samples from both untrained and resistance-trained men and women contained evidence of damage. Ultrastructural analysis confirmed that degenerative-regenerative processes were occurring in both groups. However, training subjects had a four-fold greater number of damaged fibers than nontraining subjects (8.53% vs 2.08%). In addition, only biopsy samples from training individuals contained fibers with internal disorganization (e.g., Z-line streaming, myofibrillar disruption). Calpain II levels in the biopsy samples and serum creatine kinase activity were not significantly affected supporting the light and electron microscopic observations that most of the damaged fibers were normal in appearance except for their small diameter. In summary, focal damage induced by the biopsy procedure is not completely repaired after 2 weeks and could affect the results, particularly cross-sectional area measurements. Moreover, resistance training appears to cause additional damage to the muscle and may delay repair of the biopsied region.
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Affiliation(s)
- R S Staron
- Department of Zoological and Biomedical Sciences, College of Osteopathic Medicine, Ohio University, Athens 45701
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Johnson P. Calpains (intracellular calcium-activated cysteine proteinases): structure-activity relationships and involvement in normal and abnormal cellular metabolism. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1990; 22:811-22. [PMID: 2279616 DOI: 10.1016/0020-711x(90)90284-a] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
1. Calpains (calcium-activated cysteine proteinases) have evolved by gene fusion events involving calmodulin-like genes, cysteine proteinase genes and other sequences of unknown origin. 2. The enzymes are composed of two non-identical subunits, each of which contains functional calcium-binding sequences. 3. Calpains are inhibited by the endogenous protein inhibitor, calpastatin and some calmodulin antagonists are also inhibitors of calpain. A number of synthetic proteinase inhibitors also inhibit calpains. 4. Calpains can be activated by phospholipids, an endogenous protein activator and some amino acid derivatives. 5. Various protein substrates for calpains have been recognized in vitro, but the identity of in situ substrates remains unclear. 6. Proposals have been made for calpain function, including involvement in signal transduction, platelet activation, cell fusion, mitosis and cytoskeleton and contractile protein turnover. 7. Calpain and calpastatin expression is altered in a number of abnormal states including muscular dystrophy, muscle denervation and tenotomy, hypertension and platelet abnormalities.
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Affiliation(s)
- P Johnson
- Department of Chemistry, Ohio University, Athens, 45701
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Blomgren K, Karlsson JO. Developmental changes of calpain and calpastatin in rabbit brain. Neurochem Res 1989; 14:1149-52. [PMID: 2556650 DOI: 10.1007/bf00965622] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A major part of the Ca-activated proteolytic activity in the soluble fraction from rabbit brain could be due to the activity of the neutral thiol-proteases calpain I and II. The activity of calpains exceeded that of the endogenous inhibitor, calpastatin, at all developmental stages studied. The level of calpains increased rapidly from the prenatal stage to reach a peak 10-20 days postnatally. From this period the level of calpains decreased slowly to reach the adult levels. The level of calpastatin increased steadily from the prenatal stage to old age.
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Affiliation(s)
- K Blomgren
- Institute of Neurobiology, University of Göteborg, Sweden
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Johnson P, Hammer JL. Calpain and calpastatin levels in dystrophic hamster skeletal muscles. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1988; 20:1227-30. [PMID: 2854796 DOI: 10.1016/0020-711x(88)90223-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
1. Two fast-twitch skeletal muscles from normal and dystrophic hamsters were analysed for their calpain and calpastatin contents. 2. Assays of wide-specificity calpain II showed that the activity levels in the two muscles were increased 1.5 and 1.6 times in dystrophic animals. 3. Analysis of calpastatin levels showed that the respective dystrophic muscles had activity levels of 2.2 and 2.8 times those of control muscles. 4. These results contrast with previous studies on denervated hamster muscles which showed that denervation causes an increase in calpain levels but a decrease in calpastatin levels.
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Affiliation(s)
- P Johnson
- Department of Chemistry, Ohio University, Athens 45701
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