1
|
Wan Y, Piao L, Xu S, Inoue A, Meng X, Lei Y, Huang Z, Wang H, Yue X, Shi GP, Kuzuya M, Cheng XW. Cathepsin S deficiency improves muscle mass loss and dysfunction via the modulation of protein metabolism in mice under pathological stress conditions. FASEB J 2023; 37:e23086. [PMID: 37428652 DOI: 10.1096/fj.202300395rrr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 06/19/2023] [Accepted: 06/27/2023] [Indexed: 07/12/2023]
Abstract
Cathepsin S (CTSS) is a widely expressed cysteinyl protease that has garnered attention because of its enzymatic and non-enzymatic functions under inflammatory and metabolic pathological conditions. Here, we examined whether CTSS participates in stress-related skeletal muscle mass loss and dysfunction, focusing on protein metabolic imbalance. Eight-week-old male wildtype (CTSS+/+ ) and CTSS-knockout (CTSS-/- ) mice were randomly assigned to non-stress and variable-stress groups for 2 weeks, and then processed for morphological and biochemical studies. Compared with non-stressed mice, stressed CTSS+/+ mice showed significant losses of muscle mass, muscle function, and muscle fiber area. In this setting, the stress-induced harmful changes in the levels of oxidative stress-related (gp91phox and p22phox ,), inflammation-related (SDF-1, CXCR4, IL-1β, TNF-α, MCP-1, ICAM-1, and VCAM-1), mitochondrial biogenesis-related (PPAR-γ and PGC-1α) genes and/or proteins and protein metabolism-related (p-PI3K, p-Akt, p-FoxO3α, MuRF-1, and MAFbx1) proteins; and these alterations were rectified by CTSS deletion. Metabolomic analysis revealed that stressed CTSS-/- mice exhibited a significant improvement in the levels of glutamine metabolism pathway products. Thus, these findings indicated that CTSS can control chronic stress-related skeletal muscle atrophy and dysfunction by modulating protein metabolic imbalance, and thus CTSS was suggested to be a promising new therapeutic target for chronic stress-related muscular diseases.
Collapse
Affiliation(s)
- Ying Wan
- Department of Cardiology and Hypertension, Jilin Provincial Key Laboratory of Stress and Cardiovascular Disease, Yanbian University Hospital, Yanji, P.R. China
- Jilin Provincial Key Laboratory of Stress and Cardiovascular Disease, Yanbian University Hospital, Yanji, P.R. China
| | - Limei Piao
- Department of Cardiology and Hypertension, Jilin Provincial Key Laboratory of Stress and Cardiovascular Disease, Yanbian University Hospital, Yanji, P.R. China
- Jilin Provincial Key Laboratory of Stress and Cardiovascular Disease, Yanbian University Hospital, Yanji, P.R. China
| | - Shengnan Xu
- Department of Cardiology and Hypertension, Jilin Provincial Key Laboratory of Stress and Cardiovascular Disease, Yanbian University Hospital, Yanji, P.R. China
- Jilin Provincial Key Laboratory of Stress and Cardiovascular Disease, Yanbian University Hospital, Yanji, P.R. China
| | - Aiko Inoue
- Institute of Nano-Life-Systems, Innovation for Future Society, Nagoya University Institutes of Innovation for Future Society, Nagoya, Japan
| | - Xiangkun Meng
- Department of Vascular Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yanna Lei
- Department of Cardiology and Hypertension, Jilin Provincial Key Laboratory of Stress and Cardiovascular Disease, Yanbian University Hospital, Yanji, P.R. China
- Jilin Provincial Key Laboratory of Stress and Cardiovascular Disease, Yanbian University Hospital, Yanji, P.R. China
| | - Zhe Huang
- Department of Neurology, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Hailong Wang
- Department of Cardiology and Hypertension, Jilin Provincial Key Laboratory of Stress and Cardiovascular Disease, Yanbian University Hospital, Yanji, P.R. China
- Jilin Provincial Key Laboratory of Stress and Cardiovascular Disease, Yanbian University Hospital, Yanji, P.R. China
| | - Xueling Yue
- Department of Cardiology and Hypertension, Jilin Provincial Key Laboratory of Stress and Cardiovascular Disease, Yanbian University Hospital, Yanji, P.R. China
- Jilin Provincial Key Laboratory of Stress and Cardiovascular Disease, Yanbian University Hospital, Yanji, P.R. China
| | - Guo-Ping Shi
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Masafumi Kuzuya
- Institute of Nano-Life-Systems, Innovation for Future Society, Nagoya University Institutes of Innovation for Future Society, Nagoya, Japan
- Meitetsu Hospital, Nagoya, Japan
| | - Xian Wu Cheng
- Department of Cardiology and Hypertension, Jilin Provincial Key Laboratory of Stress and Cardiovascular Disease, Yanbian University Hospital, Yanji, P.R. China
- Jilin Provincial Key Laboratory of Stress and Cardiovascular Disease, Yanbian University Hospital, Yanji, P.R. China
| |
Collapse
|
2
|
Yamakawa T, Zhang G, Najjar LB, Li C, Itakura K. The uncharacterized transcript KIAA0930 confers a cachexic phenotype on cancer cells. Oncotarget 2023; 14:723-737. [PMID: 37477523 PMCID: PMC10360925 DOI: 10.18632/oncotarget.28476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/22/2023] Open
Abstract
Patients with cancer cachexia have a poor prognosis and impaired quality of life. Numerous studies using preclinical models have shown that inflammatory cytokines play an important role in the development of cancer cachexia; however, no clinical trial targeting cytokines has been successful. Therefore, it is essential to identify molecular mechanisms to develop anti-cachexia therapies. Here we identified the uncharacterized transcript KIAA0930 as a candidate cachexic factor based on analyses of microarray datasets and an in vitro muscle atrophy assay. While conditioned media from pancreatic, colorectal, gastric, and tongue cancer cells caused muscle atrophy in vitro, conditioned medium from KIAA0930 knockdown cells did not. The PANC-1 orthotopic xenograft study showed that the tibialis anterior muscle weight and cross-sectional area were increased in mice bearing KIAA0930 knockdown cells compared to control mice. Interestingly, KIAA0930 knockdown did not cause consistent changes in the secretion of inflammatory cytokines/chemokines from a variety of cancer cell lines. An initial characterization experiment showed that KIAA0930 is localized in the cytosol and not secreted from cells. These data suggest that the action of KIAA0930 is independent of the expression of cytokines/chemokines and that KIAA0930 could be a novel therapeutic target for cachexia.
Collapse
Affiliation(s)
- Takahiro Yamakawa
- Center for RNA Biology and Therapeutics, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
| | - Guoxiang Zhang
- Center for RNA Biology and Therapeutics, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
| | - Liza Bengrine Najjar
- Center for RNA Biology and Therapeutics, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
| | - Chun Li
- Center for RNA Biology and Therapeutics, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
| | - Keiichi Itakura
- Center for RNA Biology and Therapeutics, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
| |
Collapse
|
3
|
Yang N, Qi X, Hu J, Teng J, Wang Y, Li C. Exploring the mechanism of astragalus membranaceus in the treatment of multiple system atrophy based on network pharmacology and molecular docking. Medicine (Baltimore) 2023; 102:e32523. [PMID: 36749251 PMCID: PMC9901982 DOI: 10.1097/md.0000000000032523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Multiple system atrophy (MSA) is a fatal neurodegenerative disease, it causes functional degradation of multiple organs and systems throughout the body. Astragalus membranaceus (AM), a well-known traditional Chinese medicine, has been used to improve muscle wasting-related disorders for a long history. In this study, we used network pharmacology and molecular docking to predict the mechanism underlying AM for the treatment of MSA. We screened the active compounds of AM and its related targets, as well as the target proteins of MSA. We made a Venn diagram to obtain the intersecting targets and then constructed a protein-protein interaction network to find the core targets and build an active ingredient-target network map. After subjecting the intersecting targets to gene ontology and Kyoto encyclopedia of genes and genomes analysis, the binding ability of core compounds and core target proteins were validated by molecular docking. A total of 20 eligible compounds and 274 intersecting targets were obtained. The core components of treatment are quercetin, kaempferol, and isorhamnetin, and the core targets are TP53, RELA, and TNF. The main biological processes are related to cellular responses and regulation. Molecular functions are mainly associated with apoptosis, inflammation, and tumorigenesis. Molecular docking results show good and standard binding abilities. This study illustrates that AM treats MSA through multiple targets and pathways, and provides a reference for subsequent research.
Collapse
Affiliation(s)
- Ni Yang
- Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Xianghua Qi
- Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Jing Hu
- Shandong Public Health Clinical Center, Jinan, China
| | - Jing Teng
- Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Yuangeng Wang
- Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Chunlin Li
- Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China
- * Correspondence: Chunlin Li, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, 16369 Jingshi Road, Lixia District, Jinan, Shandong 250014, China (e-mail: )
| |
Collapse
|
4
|
Alcohol Induces Zebrafish Skeletal Muscle Atrophy through HMGB1/TLR4/NF-κB Signaling. LIFE (BASEL, SWITZERLAND) 2022; 12:life12081211. [PMID: 36013390 PMCID: PMC9410481 DOI: 10.3390/life12081211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/04/2022] [Accepted: 08/06/2022] [Indexed: 11/17/2022]
Abstract
Excessive alcohol consumption can cause alcoholic myopathy, but the molecular mechanism is still unclear. In this study, zebrafish were exposed to 0.5% alcohol for eight weeks to investigate the effect of alcohol on skeletal muscle and its molecular mechanism. The results showed that the body length, body weight, cross-sectional area of the skeletal muscle fibers, Ucrit, and MO2max of the zebrafish were significantly decreased after alcohol exposure. The expression of markers of skeletal muscle atrophy and autophagy was increased, and the expression of P62 was significantly reduced. The content of ROS, the mRNA expression of sod1 and sod2, and the protein expression of Nox2 were significantly increased. In addition, we found that the inflammatory factors Il1β and Tnfα were significantly enriched in skeletal muscle, and the expression of the HMGB1/TLR4/NF-κB signaling axis was also significantly increased. In summary, in this study, we established a zebrafish model of alcohol-induced skeletal muscle atrophy and further elucidated its pathogenesis.
Collapse
|
5
|
Identification of Potential miRNA-mRNA Regulatory Network in Denervated Muscular Atrophy by Bioinformatic Analysis. BIOMED RESEARCH INTERNATIONAL 2022; 2022:6042591. [PMID: 35800215 PMCID: PMC9256438 DOI: 10.1155/2022/6042591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 05/27/2022] [Indexed: 11/17/2022]
Abstract
Muscle atrophy caused by long-term denervation leads to the loss of skeletal muscle mass and strength, resulting in a poor recovery of functional muscles and decreasing quality of life. Increasing differentially expressed microRNAs (DEMs) have been reported to be involved in the pathogenesis of denervated muscle atrophy. However, there is still insufficient evidence to explain the role of miRNAs and their target genes in skeletal muscle atrophy. Therefore, an integrative exploration of the miRNA-mRNA regulatory network in denervated muscle atrophy is necessary. A total of 21 (16 upregulated and 5 downregulated) DEMs were screened out in the GSE81914 dataset. Med1, Myod1, Nfkb1, Rela, and Camta1 were predicted and verified to be significantly upregulated in denervated muscle atrophy, from which 6 key TF-miRNA relationship pairs, including Med1-mir-1949, Med1-mir-146b, Myod1-mir-29b, Nfkb1-mir-21, Rela-mir-21, and Camta1-mir-132, were obtained. 60 target genes were then predicted by submitting candidate DEMs to the miRNet database. GO and KEGG pathway enrichment analysis showed that target genes of DEMs were mainly enriched in the apoptotic process and PI3K/Akt signaling pathway. Through the PPI network construction, key modules and hub genes were obtained and potentially modulated by mir-29b, mir-132, and mir-133a. According to the qRT-PCR results, the expression of COL1A1 and Ctgf is opposite to their related miRNAs in denervated muscle atrophy. In the study, a potential miRNA-mRNA regulatory network was firstly constructed in denervated muscle atrophy, in which the mir-29b-COL1A1 and mir-133a-Ctgf pathways may provide new insights into the pathogenesis and treatment.
Collapse
|
6
|
Graca FA, Rai M, Hunt LC, Stephan A, Wang YD, Gordon B, Wang R, Quarato G, Xu B, Fan Y, Labelle M, Demontis F. The myokine Fibcd1 is an endogenous determinant of myofiber size and mitigates cancer-induced myofiber atrophy. Nat Commun 2022; 13:2370. [PMID: 35501350 PMCID: PMC9061726 DOI: 10.1038/s41467-022-30120-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 04/14/2022] [Indexed: 12/19/2022] Open
Abstract
Decline in skeletal muscle cell size (myofiber atrophy) is a key feature of cancer-induced wasting (cachexia). In particular, atrophy of the diaphragm, the major muscle responsible for breathing, is an important determinant of cancer-associated mortality. However, therapeutic options are limited. Here, we have used Drosophila transgenic screening to identify muscle-secreted factors (myokines) that act as paracrine regulators of myofiber growth. Subsequent testing in mouse myotubes revealed that mouse Fibcd1 is an evolutionary-conserved myokine that preserves myofiber size via ERK signaling. Local administration of recombinant Fibcd1 (rFibcd1) ameliorates cachexia-induced myofiber atrophy in the diaphragm of mice bearing patient-derived melanoma xenografts and LLC carcinomas. Moreover, rFibcd1 impedes cachexia-associated transcriptional changes in the diaphragm. Fibcd1-induced signaling appears to be muscle selective because rFibcd1 increases ERK activity in myotubes but not in several cancer cell lines tested. We propose that rFibcd1 may help reinstate myofiber size in the diaphragm of patients with cancer cachexia.
Collapse
Affiliation(s)
- Flavia A Graca
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, United States
- Solid Tumor Program, Comprehensive Cancer Center, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Mamta Rai
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, United States
- Solid Tumor Program, Comprehensive Cancer Center, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Liam C Hunt
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, United States
- Solid Tumor Program, Comprehensive Cancer Center, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Anna Stephan
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, United States
- Solid Tumor Program, Comprehensive Cancer Center, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Yong-Dong Wang
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN, United States
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Brittney Gordon
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, United States
- Solid Tumor Program, Comprehensive Cancer Center, St. Jude Children's Research Hospital, Memphis, TN, United States
- Xenograft Core, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Ruishan Wang
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, United States
- Solid Tumor Program, Comprehensive Cancer Center, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Giovanni Quarato
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Beisi Xu
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN, United States
- Center for Applied Bioinformatics, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Yiping Fan
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN, United States
- Center for Applied Bioinformatics, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Myriam Labelle
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, United States
- Solid Tumor Program, Comprehensive Cancer Center, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Fabio Demontis
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, United States.
- Solid Tumor Program, Comprehensive Cancer Center, St. Jude Children's Research Hospital, Memphis, TN, United States.
| |
Collapse
|
7
|
Decreased miR-497-5p Suppresses IL-6 Induced Atrophy in Muscle Cells. Cells 2021; 10:cells10123527. [PMID: 34944037 PMCID: PMC8700610 DOI: 10.3390/cells10123527] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/24/2021] [Accepted: 12/01/2021] [Indexed: 12/11/2022] Open
Abstract
Interleukin-6 (IL-6) is a pro-inflammatory cytokine associated with skeletal muscle wasting in cancer cachexia. The control of gene expression by microRNAs (miRNAs) in muscle wasting involves the regulation of thousands of target transcripts. However, the miRNA-target networks associated with IL6-induced muscle atrophy remain to be characterized. Here, we show that IL-6 promotes the atrophy of C2C12 myotubes and changes the expression of 20 miRNAs (5 up-regulated and 15 down-regulated). Gene Ontology analysis of predicted miRNAs targets revealed post-transcriptional regulation of genes involved in cell differentiation, apoptosis, migration, and catabolic processes. Next, we performed a meta-analysis of miRNA-published data that identified miR-497-5p, a down-regulated miRNAs induced by IL-6, also down-regulated in other muscle-wasting conditions. We used miR-497-5p mimics and inhibitors to explore the function of miR-497-5p in C2C12 myoblasts and myotubes. We found that miR-497-5p can regulate the expression of the cell cycle genes CcnD2 and CcnE1 without affecting the rate of myoblast cellular proliferation. Notably, miR-497-5p mimics induced myotube atrophy and reduced Insr expression. Treatment with miR-497-5p inhibitors did not change the diameter of the myotubes but increased the expression of its target genes Insr and Igf1r. These genes are known to regulate skeletal muscle regeneration and hypertrophy via insulin-like growth factor pathway and were up-regulated in cachectic muscle samples. Our miRNA-regulated network analysis revealed a potential role for miR-497-5p during IL6-induced muscle cell atrophy and suggests that miR-497-5p is likely involved in a compensatory mechanism of muscle atrophy in response to IL-6.
Collapse
|
8
|
Haberecht-Müller S, Krüger E, Fielitz J. Out of Control: The Role of the Ubiquitin Proteasome System in Skeletal Muscle during Inflammation. Biomolecules 2021; 11:biom11091327. [PMID: 34572540 PMCID: PMC8468834 DOI: 10.3390/biom11091327] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 09/01/2021] [Accepted: 09/03/2021] [Indexed: 02/07/2023] Open
Abstract
The majority of critically ill intensive care unit (ICU) patients with severe sepsis develop ICU-acquired weakness (ICUAW) characterized by loss of muscle mass, reduction in myofiber size and decreased muscle strength leading to persisting physical impairment. This phenotype results from a dysregulated protein homeostasis with increased protein degradation and decreased protein synthesis, eventually causing a decrease in muscle structural proteins. The ubiquitin proteasome system (UPS) is the predominant protein-degrading system in muscle that is activated during diverse muscle atrophy conditions, e.g., inflammation. The specificity of UPS-mediated protein degradation is assured by E3 ubiquitin ligases, such as atrogin-1 and MuRF1, which target structural and contractile proteins, proteins involved in energy metabolism and transcription factors for UPS-dependent degradation. Although the regulation of activity and function of E3 ubiquitin ligases in inflammation-induced muscle atrophy is well perceived, the contribution of the proteasome to muscle atrophy during inflammation is still elusive. During inflammation, a shift from standard- to immunoproteasome was described; however, to which extent this contributes to muscle wasting and whether this changes targeting of specific muscular proteins is not well described. This review summarizes the function of the main proinflammatory cytokines and acute phase response proteins and their signaling pathways in inflammation-induced muscle atrophy with a focus on UPS-mediated protein degradation in muscle during sepsis. The regulation and target-specificity of the main E3 ubiquitin ligases in muscle atrophy and their mode of action on myofibrillar proteins will be reported. The function of the standard- and immunoproteasome in inflammation-induced muscle atrophy will be described and the effects of proteasome-inhibitors as treatment strategies will be discussed.
Collapse
Affiliation(s)
- Stefanie Haberecht-Müller
- Institute of Medical Biochemistry and Molecular Biology, University Medicine Greifswald, 17475 Greifswald, Germany;
| | - Elke Krüger
- Institute of Medical Biochemistry and Molecular Biology, University Medicine Greifswald, 17475 Greifswald, Germany;
- Correspondence: (E.K.); (J.F.)
| | - Jens Fielitz
- DZHK (German Centre for Cardiovascular Research), Partner Site Greifswald, 17475 Greifswald, Germany
- Department of Internal Medicine B, Cardiology, University Medicine Greifswald, 17475 Greifswald, Germany
- Correspondence: (E.K.); (J.F.)
| |
Collapse
|
9
|
Li C, Wu Q, Li Z, Wang Z, Tu Y, Chen C, Sun S, Sun S. Exosomal microRNAs in cancer-related sarcopenia: Tumor-derived exosomal microRNAs in muscle atrophy. Exp Biol Med (Maywood) 2021; 246:1156-1166. [PMID: 33554647 DOI: 10.1177/1535370221990322] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Cancer-associated sarcopenia is a complex metabolic syndrome marked by muscle mass wasting. Muscle wasting is a serious complication that is a primary contributor to cancer-related mortality. The underlying molecular mechanisms of cancer-associated sarcopenia have not been completely described to date. In general, evidence shows that the main pathophysiological alterations in sarcopenia are associated with the degradation of cellular components, an exceptional inflammatory secretome and mitochondrial dysfunction. Importantly, we highlight the prospect that several miRNAs carried by tumor-derived exosomes that have shown the ability to promote inflammatory secretion, activate catabolism, and even participate in the regulation of cellular degradation pathways can be delivered to and exert effects on muscle cells. In this review, we aim to describe the current knowledge about the functions of exosomal miRNAs in the induction of cancer-associated muscle wasting and propose potential treatment strategies.
Collapse
Affiliation(s)
- Chenyuan Li
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan 430060, PR China
| | - Qi Wu
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan 430060, PR China
| | - Zhiyu Li
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan 430060, PR China
| | - Zhong Wang
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan 430060, PR China
| | - Yi Tu
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan 430060, PR China
| | - Chuang Chen
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan 430060, PR China
| | - Si Sun
- Department of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan 430060, PR China
| | - Shengrong Sun
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan 430060, PR China
| |
Collapse
|
10
|
Duan K, Gao X, Zhu D. The clinical relevance and mechanism of skeletal muscle wasting. Clin Nutr 2020; 40:27-37. [PMID: 32788088 DOI: 10.1016/j.clnu.2020.07.029] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 06/15/2020] [Accepted: 07/21/2020] [Indexed: 02/08/2023]
Abstract
Skeletal muscle wasting occurs in both chronic and acute diseases. Increasing evidence has shown this debilitating process is associated with short- and long-term outcomes in critical, cancer and surgical patients. Both muscle quantity and quality, as reflected by the area and density of a given range of attenuation in CT scan, impact the patient prognosis. In addition, ultrasound and bioelectrical impedance analysis (BIA) are also widely used in the assessment of body composition due to their bedside viability and no radioactivity. Mechanism researches have revealed complicated pathways are involved in muscle wasting, which include altered IGF1-Akt-FoxO signaling, elevated levels of myostatin and activin A, activation of NF-κB pathway and glucocorticoid effects. Particularly, central nervous system (CNS) has been proven to participate in regulating muscle wasting in various conditions, such as infection and tumor. Several promising therapeutic agents have been under developing in the treatment of muscle atrophy, such as myostatin antagonist, ghrelin analog, non-steroidal selective androgen receptor modulators (SARMs). Notably, nutritional therapy is still the fundamental support in combating muscle wasting. However, the optimizing and tailored nutrition regimen relies on accurate metabolism measurement and large clinical trials in the future. Here, we will discuss the current understanding of muscle wasting and potential treatment in clinical practice.
Collapse
Affiliation(s)
- Kaipeng Duan
- Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215006, PR China
| | - Xin Gao
- Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215006, PR China
| | - Dongming Zhu
- Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215006, PR China.
| |
Collapse
|
11
|
Hahn A, Kny M, Pablo-Tortola C, Todiras M, Willenbrock M, Schmidt S, Schmoeckel K, Jorde I, Nowak M, Jarosch E, Sommer T, Bröker BM, Felix SB, Scheidereit C, Weber-Carstens S, Butter C, Luft FC, Fielitz J. Serum amyloid A1 mediates myotube atrophy via Toll-like receptors. J Cachexia Sarcopenia Muscle 2020; 11:103-119. [PMID: 31441598 PMCID: PMC7015249 DOI: 10.1002/jcsm.12491] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 06/28/2019] [Accepted: 07/22/2019] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Critically ill patients frequently develop muscle atrophy and weakness in the intensive-care-unit setting [intensive care unit-acquired weakness (ICUAW)]. Sepsis, systemic inflammation, and acute-phase response are major risk factors. We reported earlier that the acute-phase protein serum amyloid A1 (SAA1) is increased and accumulates in muscle of ICUAW patients, but its relevance was unknown. Our objectives were to identify SAA1 receptors and their downstream signalling pathways in myocytes and skeletal muscle and to investigate the role of SAA1 in inflammation-induced muscle atrophy. METHODS We performed cell-based in vitro and animal in vivo experiments. The atrophic effect of SAA1 on differentiated C2C12 myotubes was investigated by analysing gene expression, protein content, and the atrophy phenotype. We used the cecal ligation and puncture model to induce polymicrobial sepsis in wild type mice, which were treated with the IкB kinase inhibitor Bristol-Myers Squibb (BMS)-345541 or vehicle. Morphological and molecular analyses were used to investigate the phenotype of inflammation-induced muscle atrophy and the effects of BMS-345541 treatment. RESULTS The SAA1 receptors Tlr2, Tlr4, Cd36, P2rx7, Vimp, and Scarb1 were all expressed in myocytes and skeletal muscle. Treatment of differentiated C2C12 myotubes with recombinant SAA1 caused myotube atrophy and increased interleukin 6 (Il6) gene expression. These effects were mediated by Toll-like receptors (TLR) 2 and 4. SAA1 increased the phosphorylation and activity of the transcription factor nuclear factor 'kappa-light-chain-enhancer' of activated B-cells (NF-κB) p65 via TLR2 and TLR4 leading to an increased binding of NF-κB to NF-κB response elements in the promoter region of its target genes resulting in an increased expression of NF-κB target genes. In polymicrobial sepsis, skeletal muscle mass, tissue morphology, gene expression, and protein content were associated with the atrophy response. Inhibition of NF-κB signalling by BMS-345541 increased survival (28.6% vs. 91.7%, P < 0.01). BMS-345541 diminished inflammation-induced atrophy as shown by a reduced weight loss of the gastrocnemius/plantaris (vehicle: -21.2% and BMS-345541: -10.4%; P < 0.05), tibialis anterior (vehicle: -22.7% and BMS-345541: -17.1%; P < 0.05) and soleus (vehicle: -21.1% and BMS-345541: -11.3%; P < 0.05) in septic mice. Analysis of the fiber type specific myocyte cross-sectional area showed that BMS-345541 reduced inflammation-induced atrophy of slow/type I and fast/type II myofibers compared with vehicle-treated septic mice. BMS-345541 reversed the inflammation-induced atrophy program as indicated by a reduced expression of the atrogenes Trim63/MuRF1, Fbxo32/Atrogin1, and Fbxo30/MuSA1. CONCLUSIONS SAA1 activates the TLR2/TLR4//NF-κB p65 signalling pathway to cause myocyte atrophy. Systemic inhibition of the NF-κB pathway reduced muscle atrophy and increased survival of septic mice. The SAA1/TLR2/TLR4//NF-κB p65 atrophy pathway could have utility in combatting ICUAW.
Collapse
Affiliation(s)
- Alexander Hahn
- Experimental and Clinical Research Center, Charité-Universitätsmedizin Berlin, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Melanie Kny
- Experimental and Clinical Research Center, Charité-Universitätsmedizin Berlin, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Cristina Pablo-Tortola
- Experimental and Clinical Research Center, Charité-Universitätsmedizin Berlin, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Mihail Todiras
- Cardiovascular hormones, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Nicolae Testemiţanu State University of Medicine and Pharmacy, Chișinău, Moldova
| | - Michael Willenbrock
- Signal Transduction in Tumor Cells, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Sibylle Schmidt
- Experimental and Clinical Research Center, Charité-Universitätsmedizin Berlin, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Katrin Schmoeckel
- Department of Immunology, Institute of Immunology and Transfusion Medicine, University Medicine, Greifswald, Germany
| | - Ilka Jorde
- Department of Immunology, Institute of Immunology and Transfusion Medicine, University Medicine, Greifswald, Germany
| | - Marcel Nowak
- Experimental and Clinical Research Center, Charité-Universitätsmedizin Berlin, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Intracellular Proteolysis, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Ernst Jarosch
- Intracellular Proteolysis, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Thomas Sommer
- Intracellular Proteolysis, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Institute of Biology, Humboldt-University Berlin, Berlin, Germany.,DZHK (German Center for Cardiovascular Research), Partner Site Berlin, Berlin, Germany
| | - Barbara M Bröker
- Department of Immunology, Institute of Immunology and Transfusion Medicine, University Medicine, Greifswald, Germany
| | - Stephan B Felix
- Department of Internal Medicine B, Cardiology, University Medicine Greifswald, Greifswald, Germany.,DZHK (German Center for Cardiovascular Research), Partner Site Greifswald, Greifswald, Germany
| | - Claus Scheidereit
- Signal Transduction in Tumor Cells, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Steffen Weber-Carstens
- Department of Anesthesiology and Intensive Care Medicine, Campus Virchow-Klinikum and Campus Charité Mitte, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Berlin Institute of Health (BIH), Berlin, Germany
| | - Christian Butter
- Department of Cardiology, Heart Center Brandenburg and Medical University Brandenburg (MHB), Bernau, Germany
| | - Friedrich C Luft
- Experimental and Clinical Research Center, Charité-Universitätsmedizin Berlin, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Jens Fielitz
- Experimental and Clinical Research Center, Charité-Universitätsmedizin Berlin, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Department of Internal Medicine B, Cardiology, University Medicine Greifswald, Greifswald, Germany.,DZHK (German Center for Cardiovascular Research), Partner Site Greifswald, Greifswald, Germany.,Berlin Institute of Health (BIH), Berlin, Germany
| |
Collapse
|
12
|
Molina Peña ME, Sánchez CM, Rodríguez-Triviño CY. Physiopathological mechanisms of diaphragmatic dysfunction associated with mechanical ventilation. ACTA ACUST UNITED AC 2020; 67:195-203. [PMID: 31982168 DOI: 10.1016/j.redar.2019.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 12/06/2019] [Accepted: 12/16/2019] [Indexed: 02/07/2023]
Abstract
Ventilator-induced diaphragm dysfunction (VIDD) is the loss of diaphragmatic muscle strength'related to of mechanical ventilation, noticed during the first day or 48hours after initiating controlled mechanical ventilation. This alteration has been related to disruption on the insulin growth factor/phosphoinositol 3-kinase/kinase B protein pathway (IGF/PI3K/AKT), in addition to an overexpression of FOXO, expression of NF-kB signaling, increase function of muscular ubiquitin ligase and activation of caspasa-3. VIDD has a negative impact on quality of life, duration of mechanical ventilation, and hospitalization stance and cost. More studies are necessary to understated the process and impact of VIDD. This is a narrative review of non-systematic literature, aiming to explain the molecular pathways involved in VIDD.
Collapse
Affiliation(s)
- M E Molina Peña
- Semillero de Fisiología Pr ctica aplicada, Grupo Navarra Medicina, Departamento de Ciencias Fisiológicas, Facultad de Ciencias de la Salud, Fundación Universitaria Navarra-UNINAVARRA, Neiva, Huila, Colombia.
| | - C M Sánchez
- Semillero de Fisiología Pr ctica aplicada, Grupo Navarra Medicina, Departamento de Ciencias Fisiológicas, Facultad de Ciencias de la Salud, Fundación Universitaria Navarra-UNINAVARRA, Neiva, Huila, Colombia
| | - C Y Rodríguez-Triviño
- Grupo Navarra Medicina, Departamento de Ciencias Fisiológicas, Facultad de Ciencias de la Salud, Fundación Universitaria Navarra-UNINAVARRA, Neiva, Huila, Colombia; Grupo Cuidar, Facultad de Ciencias de la Salud, Universidad Surcolombiana, Neiva, Huila, Colombia
| |
Collapse
|
13
|
Ma W, Zhang R, Huang Z, Zhang Q, Xie X, Yang X, Zhang Q, Liu H, Ding F, Zhu J, Sun H. PQQ ameliorates skeletal muscle atrophy, mitophagy and fiber type transition induced by denervation via inhibition of the inflammatory signaling pathways. ANNALS OF TRANSLATIONAL MEDICINE 2019; 7:440. [PMID: 31700876 DOI: 10.21037/atm.2019.08.101] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Background Skeletal muscle atrophy involves and requires widespread changes in skeletal muscle gene expression and signaling pathway, resulting in excessive loss of muscle mass and strength, which is associated with poor prognosis and the decline of life quality in several diseases. However, the treatment of skeletal muscle atrophy remains an unresolved challenge to this day. The aim of the present study was to investigate the influence of pyrroloquinoline quinone (PQQ), a redox-active o-quinone found in various foods and mammalian tissues, on skeletal muscle atrophy, and to explore the underlying molecular mechanism. Methods After denervation, mice were injected intraperitoneally with saline plus PQQ (5 mg/kg/d) or saline only for 14 days. The level of inflammatory cytokines in tibialis anterior (TA) muscles was determined by quantitative real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA), and the level of signaling proteins of Janus kinase 2/signal transduction and activator of transcription 3 (Jak2/STAT3), TGF-β1/Smad3, JNK/p38 MAPK, and nuclear factor κB (NF-κB) signaling pathway were detected by Western blot. The skeletal muscle atrophy was evaluated by muscle wet weight ratio and cross-sectional areas (CSAs) of myofibers. The mitophagy was observed through transmission electron microscopy (TEM) analysis, and muscle fiber type transition was analyzed through fast myosin skeletal heavy chain antibody staining. Results The proinflammatory cytokines IL-6, IL-1β and TNF-α were largely induced in TA muscles after sciatic nerve transection. PQQ can significantly reverse this phenomenon, as evidenced by the decreased levels of proinflammatory cytokines IL-6, IL-1β and TNF-α. Moreover, PQQ could significantly attenuate the signal activation of Jak2/STAT3, TGF-β1/Smad3, JNK/p38 MAPK, and NF-κB in skeletal muscles after sciatic nerve transection. Furthermore, PQQ alleviated skeletal muscle atrophy, mitigated mitophagy and inhibited slow-to-fast muscle fiber type transition. Conclusions These results suggested that PQQ could attenuate denervation-induced skeletal muscle atrophy, mitophagy and fiber type transition through suppressing the Jak2/STAT3, TGF-β1/Smad3, JNK/p38 MAPK, and NF-κB signaling pathways.
Collapse
Affiliation(s)
- Wenjing Ma
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Ru Zhang
- Department of Imaging, The Second Affiliated Hospital of Nantong University, Nantong University, Nantong 226001, China
| | - Ziwei Huang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Qiuyu Zhang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Xiaoying Xie
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Xiaoming Yang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Qi Zhang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Hua Liu
- Department of Orthopedics, Haian Hospital of Traditional Chinese Medicine, Haian 226600, China
| | - Fei Ding
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Jianwei Zhu
- Department of Orthopedics, Affiliated Hospital of Nantong University, Nantong 226001, China
| | - Hualin Sun
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226001, China
| |
Collapse
|
14
|
Gumucio JP, Qasawa AH, Ferrara PJ, Malik AN, Funai K, McDonagh B, Mendias CL. Reduced mitochondrial lipid oxidation leads to fat accumulation in myosteatosis. FASEB J 2019; 33:7863-7881. [PMID: 30939247 DOI: 10.1096/fj.201802457rr] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Myosteatosis is the pathologic accumulation of lipid that can occur in conjunction with atrophy and fibrosis following skeletal muscle injury. Little is known about the mechanisms by which lipid accumulates in myosteatosis, but many clinical studies have demonstrated that the degree of lipid infiltration negatively correlates with muscle function and regeneration. Our objective was to determine the pathologic changes that result in lipid accumulation in injured muscle fibers. We used a rat model of rotator cuff injury in this study because the rotator cuff muscle group is particularly prone to the development of myosteatosis after injury. Muscles were collected from uninjured controls or 10, 30, or 60 d after injury and analyzed using a combination of muscle fiber contractility assessments, RNA sequencing, and undirected metabolomics, lipidomics, and proteomics, along with bioinformatics techniques to identify potential pathways and cellular processes that are dysregulated after rotator cuff tear. Bioinformatics analyses indicated that mitochondrial function was likely disrupted after injury. Based on these findings and given the role that mitochondria play in lipid metabolism, we then performed targeted biochemical and imaging studies and determined that mitochondrial dysfunction and reduced fatty acid oxidation likely leads to the accumulation of lipid in myosteatosis.-Gumucio, J. P., Qasawa, A. H., Ferrara, P. J., Malik, A. N., Funai, K., McDonagh, B., Mendias, C. L. Reduced mitochondrial lipid oxidation leads to fat accumulation in myosteatosis.
Collapse
Affiliation(s)
- Jonathan P Gumucio
- Department of Orthopedic Surgery, University of Michigan, Ann Arbor, Michigan, USA.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Austin H Qasawa
- Department of Orthopedic Surgery, University of Michigan, Ann Arbor, Michigan, USA
| | - Patrick J Ferrara
- Diabetes and Metabolism Research Center, University of Utah, Salt Lake City, Utah, USA
| | - Afshan N Malik
- Department of Diabetes, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - Katsuhiko Funai
- Diabetes and Metabolism Research Center, University of Utah, Salt Lake City, Utah, USA
| | - Brian McDonagh
- Department of Physiology, School of Medicine, National University of Ireland, Galway, Ireland
| | - Christopher L Mendias
- Department of Orthopedic Surgery, University of Michigan, Ann Arbor, Michigan, USA.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA.,Hospital for Special Surgery, New York, New York, USA.,Department of Physiology and Biophysics, Weill Cornell Medical College, New York, New York, USA
| |
Collapse
|
15
|
Fenton CG, Webster JM, Martin CS, Fareed S, Wehmeyer C, Mackie H, Jones R, Seabright AP, Lewis JW, Lai YC, Goodyear CS, Jones SW, Cooper MS, Lavery GG, Langen R, Raza K, Hardy RS. Therapeutic glucocorticoids prevent bone loss but drive muscle wasting when administered in chronic polyarthritis. Arthritis Res Ther 2019; 21:182. [PMID: 31370858 PMCID: PMC6676537 DOI: 10.1186/s13075-019-1962-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 07/22/2019] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Patients with rheumatoid arthritis (RA) experience extra-articular manifestations including osteoporosis and muscle wasting, which closely associate with severity of disease. Whilst therapeutic glucocorticoids (GCs) reduce inflammation in RA, their actions on muscle and bone metabolism in the context of chronic inflammation remain unclear. We utilised the TNF-tg model of chronic polyarthritis to ascertain the impact of therapeutic GCs on bone and muscle homeostasis in the context of systemic inflammation. METHODS TNF-tg and wild-type (WT) animals received either vehicle or the GC corticosterone (100 μg/ml) in drinking water at onset of arthritis. Arthritis severity and clinical parameters were measured, serum collected for ELISA and muscle and bone biopsies collected for μCT, histology and mRNA analysis. In vivo findings were examined in primary cultures of osteoblasts, osteoclasts and myotubes. RESULTS TNF-tg mice receiving GCs showed protection from inflammatory bone loss, characterised by a reduction in serum markers of bone resorption, osteoclast numbers and osteoclast activity. In contrast, muscle wasting was markedly increased in WT and TNF-tg animals receiving GCs, independently of inflammation. This was characterised by a reduction in muscle weight and fibre size, and an induction in anti-anabolic and catabolic signalling. CONCLUSIONS This study demonstrates that when given in early onset chronic polyarthritis, oral GCs partially protect against inflammatory bone loss, but induce marked muscle wasting. These results suggest that in patients with inflammatory arthritis receiving GCs, the development of interventions to manage deleterious side effects in muscle should be prioritised.
Collapse
Affiliation(s)
- C. G. Fenton
- 0000 0004 1936 7486grid.6572.6Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK ,0000 0004 1936 7486grid.6572.6Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK
| | - J. M. Webster
- 0000 0004 1936 7486grid.6572.6Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK ,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - C. S. Martin
- 0000 0004 1936 7486grid.6572.6Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK
| | - S. Fareed
- 0000 0004 1936 7486grid.6572.6Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK
| | - C. Wehmeyer
- 0000 0004 1936 7486grid.6572.6Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
| | - H. Mackie
- 0000 0001 2193 314Xgrid.8756.cCentre of Immunobiology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - R. Jones
- 0000 0004 1936 7486grid.6572.6MRC Arthritis Research UK Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, UK
| | - A. P. Seabright
- 0000 0004 1936 7486grid.6572.6School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - J. W. Lewis
- 0000 0004 1936 7486grid.6572.6Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK ,0000 0004 1936 7486grid.6572.6MRC Arthritis Research UK Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, UK
| | - Y. C. Lai
- 0000 0004 1936 7486grid.6572.6Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK ,0000 0004 1936 7486grid.6572.6MRC Arthritis Research UK Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, UK ,0000 0004 1936 7486grid.6572.6School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - C. S. Goodyear
- 0000 0001 2193 314Xgrid.8756.cCentre of Immunobiology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - S. W Jones
- 0000 0004 1936 7486grid.6572.6Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
| | - M. S. Cooper
- 0000 0004 1936 834Xgrid.1013.3ANZAC Research Institute, University of Sydney, Sydney, Australia
| | - G. G. Lavery
- 0000 0004 1936 7486grid.6572.6Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK ,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - R. Langen
- 0000 0001 0481 6099grid.5012.6Department of Respiratory Medicine, NUTRIM School of Nutrition and Translational Research in Metabolism, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, Netherlands
| | - K. Raza
- 0000 0004 1936 7486grid.6572.6Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK ,grid.412919.6Sandwell and West Birmingham Hospitals NHS Trust, Birmingham, UK
| | - R. S. Hardy
- 0000 0004 1936 7486grid.6572.6Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK ,0000 0004 1936 7486grid.6572.6Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK ,0000 0004 1936 7486grid.6572.6MRC Arthritis Research UK Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, UK ,0000 0004 1936 7486grid.6572.6Institute of Clinical Sciences, University of Birmingham, Birmingham, UK
| |
Collapse
|
16
|
Wang X, Zhao D, Cui Y, Lu S, Gao D, Liu J. Proinflammatory macrophages impair skeletal muscle differentiation in obesity through secretion of tumor necrosis factor‐α via sustained activation of p38 mitogen‐activated protein kinase. J Cell Physiol 2018; 234:2566-2580. [DOI: 10.1002/jcp.27012] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 06/25/2018] [Indexed: 12/17/2022]
Affiliation(s)
- Xueqiang Wang
- Center for Mitochondrial Biology and MedicineThe Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi’an Jiaotong UniversityXi’an China
| | - Daina Zhao
- Center for Mitochondrial Biology and MedicineThe Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi’an Jiaotong UniversityXi’an China
| | - Yajuan Cui
- Center for Mitochondrial Biology and MedicineThe Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi’an Jiaotong UniversityXi’an China
| | - Shemin Lu
- Department of Biochemistry and Molecular BiologySchool of Basic Medical Sciences, Xi’an Jiaotong University Health Science CenterXi’an China
| | - Dan Gao
- Center for Mitochondrial Biology and MedicineThe Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi’an Jiaotong UniversityXi’an China
| | - Jiankang Liu
- Center for Mitochondrial Biology and MedicineThe Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi’an Jiaotong UniversityXi’an China
| |
Collapse
|
17
|
Cavey T, Pierre N, Nay K, Allain C, Ropert M, Loréal O, Derbré F. Simulated microgravity decreases circulating iron in rats: role of inflammation-induced hepcidin upregulation. Exp Physiol 2018; 102:291-298. [PMID: 28087888 DOI: 10.1113/ep086188] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 01/09/2017] [Indexed: 12/19/2022]
Abstract
NEW FINDINGS What is the central question of this study? Although microgravity is well known to reduce circulating iron in astronauts, the underlying mechanism is still unknown. We investigated whether hepcidin, a key hormone regulating iron metabolism, could be involved in this deleterious effect. What is the main finding and its importance? We show that hindlimb suspension, a model of microgravity, stimulates the production of hepcidin in liver of rats. In agreement with the biological role of hepcidin, we found a decrease of circulating iron and an increase of spleen iron content in hindlimb-unloaded rats. Consequently, our study supports the idea that hepcidin could play a role in the alteration of iron metabolism parameters observed during spaceflight. During spaceflight, humans exposed to microgravity exhibit an increase of iron storage and a reduction of circulating iron. Such perturbations could promote oxidative stress and anaemia in astronauts. The mechanism by which microgravity modulates iron metabolism is still unknown. Herein, we hypothesized that microgravity upregulates hepcidin, a hormone produced by the liver that is the main controller of iron homeostasis. To test this hypothesis, rats were submitted to hindlimb unloading (HU), the reference model to mimic the effects of microgravity in rodents. After 7 days, the mRNA level of hepcidin was increased in the liver of HU rats (+74%, P = 0.001). In agreement with the biological role of hepcidin, we found an increase of spleen iron content (+78%, P = 0.030) and a decrease of serum iron concentration (-35%, P = 0.002) and transferrin saturation (-25%, P = 0.011) in HU rats. These findings support a role of hepcidin in microgravity-induced iron metabolism alteration. Furthermore, among the signalling pathways inducing hepcidin mRNA expression, we found that only the interleukin-6/signal transducer and activator of transcription 3 (IL-6/STAT3) axis was activated by HU, as shown by the increase of phospho-STAT3 (+193%, P < 0.001) and of the hepatic mRNA level of haptoglobin (+167%, P < 0.001), a STAT3-inducible gene, in HU rats. Taken together, these data support the idea that microgravity may alter iron metabolism through an inflammatory process upregulating hepcidin.
Collapse
Affiliation(s)
- Thibault Cavey
- INSERM UMR 991 UMR, Rennes, France.,University of Rennes 1, Rennes, France.,Department of Biochemistry, CHU Rennes, France
| | - Nicolas Pierre
- Laboratory 'Movement, Sport and Health Sciences' (M2S), University Rennes 2-ENS Rennes, Bruz, France
| | - Kévin Nay
- Laboratory 'Movement, Sport and Health Sciences' (M2S), University Rennes 2-ENS Rennes, Bruz, France
| | - Coralie Allain
- INSERM UMR 991 UMR, Rennes, France.,University of Rennes 1, Rennes, France
| | - Martine Ropert
- INSERM UMR 991 UMR, Rennes, France.,Department of Biochemistry, CHU Rennes, France
| | - Olivier Loréal
- INSERM UMR 991 UMR, Rennes, France.,University of Rennes 1, Rennes, France
| | - Frédéric Derbré
- Laboratory 'Movement, Sport and Health Sciences' (M2S), University Rennes 2-ENS Rennes, Bruz, France
| |
Collapse
|
18
|
Gopinath SD. Inhibition of Stat3 signaling ameliorates atrophy of the soleus muscles in mice lacking the vitamin D receptor. Skelet Muscle 2017; 7:2. [PMID: 28122601 PMCID: PMC5264327 DOI: 10.1186/s13395-017-0121-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 01/13/2017] [Indexed: 11/10/2022] Open
Abstract
Background Although skeletal muscle wasting has long been observed as a clinical outcome of impaired vitamin D signaling, precise molecular mechanisms that mediate the loss of muscle mass in the absence of vitamin D signaling are less clear. To determine the molecular consequences of vitamin D signaling, we analyzed the role of signal transducer and activator of transcription 3 (Stat3) signaling, a known contributor to various muscle wasting pathologies, in skeletal muscles. Methods We isolated soleus (slow) and tibialis anterior (fast) muscles from mice lacking the vitamin D receptor (VDR−/−) and used western blot analysis, quantitative RTPCR, and pharmacological intervention to analyze muscle atrophy in VDR−/− mice. Results We found that slow and fast subsets of muscles of the VDR−/− mice displayed elevated levels of phosphorylated Stat3 accompanied by an increase in Myostatin expression and signaling. Consequently, we observed reduced activity of mammalian target of rapamycin (mTOR) signaling components, ribosomal S6 kinase (p70S6K) and ribosomal S6 protein (rpS6), that regulate protein synthesis and cell size, respectively. Concomitantly, we observed an increase in atrophy regulators and a block in autophagic gene expression. An examination of the upstream regulation of Stat3 levels in VDR−/− muscles revealed an increase in IL-6 protein expression in the soleus, but not in the tibialis anterior muscles. To investigate the involvement of satellite cells (SCs) in atrophy in VDR−/− mice, we found that there was no significant deficit in SC numbers in VDR−/− muscles compared to the wild type. Unlike its expression within VDR−/− fibers, Myostatin levels in VDR−/− SCs from bulk muscles were similar to those of wild type. However, VDR−/− SCs induced to differentiate in culture displayed increased p-Stat3 signaling and Myostatin expression. Finally, VDR−/− mice injected with a Stat3 inhibitor displayed reduced Myostatin expression and function and restored active p70S6K and rpS6 levels, resulting in an amelioration of loss of muscle mass in the soleus muscles. Conclusions The loss of muscle mass in slow muscles in the absence of vitamin D signaling is due to elevated levels of phosphorylated Stat3 that leads to an increase in Myostatin signaling, which in turn decreases protein synthesis and fiber size through the phosphorylation of p70S6K and rpS6, respectively. Electronic supplementary material The online version of this article (doi:10.1186/s13395-017-0121-2) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Suchitra D Gopinath
- Translational Health Science and Technology Institute (THSTI), NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, PO box #04, Faridabad, 121001, India.
| |
Collapse
|
19
|
Park YW, Kim SG, Jo YY. S100 and p65 expression are increased in the masseter muscle after botulinum toxin-A injection. Maxillofac Plast Reconstr Surg 2016; 38:33. [PMID: 27635391 PMCID: PMC5002051 DOI: 10.1186/s40902-016-0079-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 08/22/2016] [Indexed: 11/10/2022] Open
Abstract
Background The purpose of this study was to compare the expression levels of p65 and S100 in the rat masseter muscle after the injection of different concentrations of botulinum toxin-A (BTX-A). Methods We injected either 5 or 10 U of BTX-A into both masseter muscle of rats. As a control group, the same volume of saline was injected. After 14 days, the animals were sacrificed. Subsequently, a biopsy and immunohistochemical staining of the samples were performed using a p65 or S100 antibody. Results The cross-sectional area of each myofibril was significantly reduced by BTX-A injection (P < 0.001). The expression of p65 and S100 increased significantly with increasing concentrations of BTX-A (P < 0.001). Conclusions The injection of BTX-A into the masseter muscle induced muscle atrophy. Subsequently, p65 and S100 expression in myoblasts were increased for the protection of muscle cells.
Collapse
Affiliation(s)
- Young-Wook Park
- Department of Oral and Maxillofacial Surgery, College of Dentistry, Gangneung-Wonju National University, 7 Jukhyun-gil, Gangneung, 210-702 South Korea
| | - Seong-Gon Kim
- Department of Oral and Maxillofacial Surgery, College of Dentistry, Gangneung-Wonju National University, 7 Jukhyun-gil, Gangneung, 210-702 South Korea
| | - You-Young Jo
- Sericultural and Apicultural Materials Division, National Academy of Agricultural Science, Suwon, South Korea
| |
Collapse
|
20
|
Matrix Metalloproteinase Responsive Delivery of Myostatin Inhibitors. Pharm Res 2016; 34:58-72. [DOI: 10.1007/s11095-016-2038-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Accepted: 09/06/2016] [Indexed: 12/21/2022]
|
21
|
Kim YJ, Tamadon A, Park HT, Kim H, Ku SY. The role of sex steroid hormones in the pathophysiology and treatment of sarcopenia. Osteoporos Sarcopenia 2016; 2:140-155. [PMID: 30775480 PMCID: PMC6372754 DOI: 10.1016/j.afos.2016.06.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 06/09/2016] [Accepted: 06/17/2016] [Indexed: 12/18/2022] Open
Abstract
Sex steroids influence the maintenance and growth of muscles. Decline in androgens, estrogens and progesterone by aging leads to the loss of muscular function and mass, sarcopenia. These steroid hormones can interact with different signaling pathways through their receptors. To date, sex steroid hormone receptors and their exact roles are not completely defined in skeletal and smooth muscles. Although numerous studies focused on the effects of sex steroid hormones on different types of cells, still many unexplained molecular mechanisms in both skeletal and smooth muscle cells remain to be investigated. In this paper, many different molecular mechanisms that are activated or inhibited by sex steroids and those that influence the growth, proliferation, and differentiation of skeletal and smooth muscle cells are reviewed. Also, the similarities of cellular and molecular pathways of androgens, estrogens and progesterone in both skeletal and smooth muscle cells are highlighted. The reviewed signaling pathways and participating molecules can be targeted in the future development of novel therapeutics.
Collapse
Affiliation(s)
- Yong Jin Kim
- Department of Obstetrics and Gynecology, Korea University Guro Hospital, South Korea
| | - Amin Tamadon
- Department of Obstetrics and Gynecology, College of Medicine, Seoul National University, Seoul, South Korea
| | - Hyun Tae Park
- Department of Obstetrics and Gynecology, Korea University Anam Hospital, Korea University College of Medicine, South Korea
| | - Hoon Kim
- Department of Obstetrics and Gynecology, College of Medicine, Seoul National University, Seoul, South Korea
| | - Seung-Yup Ku
- Department of Obstetrics and Gynecology, College of Medicine, Seoul National University, Seoul, South Korea
| |
Collapse
|
22
|
Fielitz J. Cancer cachexia-when proteasomal inhibition is not enough. J Cachexia Sarcopenia Muscle 2016; 7:239-45. [PMID: 27386167 PMCID: PMC4929817 DOI: 10.1002/jcsm.12124] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 04/29/2016] [Indexed: 01/06/2023] Open
Affiliation(s)
- Jens Fielitz
- Department of Molecular Cardiology, Experimental and Clinical Research Center (ECRC) Charité--Universitätsmedizin Berlin, Max Delbrück Center (MDC) for Molecular Medicine in the Helmholtz Association Berlin Germany; Department of Cardiology Heart Center Brandenburg and Medical School Brandenburg (MHB) Bernau Germany
| |
Collapse
|
23
|
Welc SS, Morse DA, Mattingly AJ, Laitano O, King MA, Clanton TL. The Impact of Hyperthermia on Receptor-Mediated Interleukin-6 Regulation in Mouse Skeletal Muscle. PLoS One 2016; 11:e0148927. [PMID: 26872389 PMCID: PMC4752463 DOI: 10.1371/journal.pone.0148927] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 12/16/2015] [Indexed: 12/19/2022] Open
Abstract
In inflammatory cells, hyperthermia inhibits lipopolysaccharide (LPS)-induced interleukin-6 (IL-6) gene expression and protein secretion. Since hyperthermia alone stimulates IL-6 in skeletal muscle, we hypothesized that it would amplify responses to other receptor-mediated stimuli. IL-6 regulation was tested in C2C12 myotubes and in soleus during treatment with epinephrine (EPI) or LPS. In EPI-treated myotubes (100 ng/ml), 1 h exposure at 40.5°C-42°C transiently increased IL-6 mRNA compared to EPI treatment alone at 37°C. In LPS-treated myotubes (1 μg/ml), exposure to 41°C-42°C also increased IL-6 mRNA. In isolated mouse soleus, similar amplifications of IL-6 gene expression were observed in 41°C, during both low (1 ng/ml) and high dose (100 ng/ml) EPI, but only in high dose LPS (1 μg/ml). In myotubes, heat increased IL-6 secretion during EPI exposure but had no effect or inhibited secretion with LPS. In soleus there were no effects of heat on IL-6 secretion during either EPI or LPS treatment. Mechanisms for the effects of heat on IL-6 mRNA were explored using a luciferase-reporter in C2C12 myotubes. Overexpression of heat shock factor-1 (HSF-1) had no impact on IL-6 promoter activity during EPI stimulation, but elevated IL-6 promoter activity during LPS stimulation. In contrast, when the activator protein-1 (AP-1) element was mutated, responses to both LPS and EPI were suppressed in heat. Using siRNA against activating transcription factor-3 (ATF-3), a heat-stress-induced inhibitor of IL-6, no ATF-3-dependent effects were observed. The results demonstrate that, unlike inflammatory cells, hyperthermia in muscle fibers amplifies IL-6 gene expression to EPI and LPS. The effect appears to reflect differential engagement of HSF-1 and AP-1 sensitive elements on the IL-6 gene, with no evidence for involvement of ATF-3. The functional significance of increased IL-6 mRNA expression during heat may serve to overcome the well-known suppression of protein synthetic pathways occurring during heat shock.
Collapse
Affiliation(s)
- Steven S. Welc
- University of Florida, Department of Applied Physiology & Kinesiology, College of Health and Human Performance, Gainesville, FL, United States of America
| | - Deborah A. Morse
- University of Florida, Department of Applied Physiology & Kinesiology, College of Health and Human Performance, Gainesville, FL, United States of America
| | - Alex J. Mattingly
- University of Florida, Department of Applied Physiology & Kinesiology, College of Health and Human Performance, Gainesville, FL, United States of America
| | - Orlando Laitano
- University of Florida, Department of Applied Physiology & Kinesiology, College of Health and Human Performance, Gainesville, FL, United States of America
- Federal University of Vale do São Francisco, Physical Education School, Petrolina, Brazil
| | - Michelle A. King
- University of Florida, Department of Applied Physiology & Kinesiology, College of Health and Human Performance, Gainesville, FL, United States of America
| | - Thomas L. Clanton
- University of Florida, Department of Applied Physiology & Kinesiology, College of Health and Human Performance, Gainesville, FL, United States of America
- * E-mail:
| |
Collapse
|
24
|
Chaillou T, Zhang X, McCarthy JJ. Expression of Muscle-Specific Ribosomal Protein L3-Like Impairs Myotube Growth. J Cell Physiol 2016; 231:1894-902. [PMID: 26684695 DOI: 10.1002/jcp.25294] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 12/17/2015] [Indexed: 12/11/2022]
Abstract
The ribosome has historically been considered to have no cell-specific function but rather serve in a "housekeeping" capacity. This view is being challenged by evidence showing that heterogeneity in the protein composition of the ribosome can lead to the functional specialization of the ribosome. Expression profiling of different tissues revealed that ribosomal protein large 3-like (Rpl3l) is exclusively expressed in striated muscle. In response to a hypertrophic stimulus, Rpl3l expression in skeletal muscle was significantly decreased by 82% whereas expression of the ubiquitous paralog Rpl3 was significantly increased by ∼fivefold. Based on these findings, we developed the hypothesis that Rpl3l functions as a negative regulator of muscle growth. To test this hypothesis, we used the Tet-On system to express Rpl3l in myoblasts during myotube formation. In support of our hypothesis, RPL3L expression significantly impaired myotube growth as assessed by myotube diameter (-23%) and protein content (-14%). Further analysis showed that the basis of this impairment was caused by a significant decrease in myoblast fusion as the fusion index was significantly lower (-17%) with RPL3L expression. These findings are the first evidence to support the novel concept of ribosome specialization in skeletal muscle and its role in the regulation of skeletal muscle growth. J. Cell. Physiol. 231: 1894-1902, 2016. © 2015 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Thomas Chaillou
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky.,Department of Physiology, College of Medicine, University of Kentucky, Lexington, Kentucky
| | - Xiping Zhang
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky.,Department of Physiology, College of Medicine, University of Kentucky, Lexington, Kentucky
| | - John J McCarthy
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky.,Department of Physiology, College of Medicine, University of Kentucky, Lexington, Kentucky
| |
Collapse
|
25
|
LaVigne EK, Jones AK, Londoño AS, Schauer AS, Patterson DF, Nadeau JA, Reed SA. Muscle growth in young horses: Effects of age, cytokines, and growth factors. J Anim Sci 2015; 93:5672-80. [PMID: 26641176 DOI: 10.2527/jas.2015-9634] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Success as equine athletes requires proper muscle growth in young horses. Muscle hypertrophy occurs through protein synthesis and the contribution of muscle satellite cells, which can be stimulated or inhibited by cytokines and growth factors present during exercise and growth. The hypotheses of this study were that 1) the LM area in young horses would increase over 1 yr, and 2) specific cytokines and growth factors (IL-1β, IL-6, tumor necrosis factor [TNF]-α, IGF-I, and fibroblast growth factor [FGF]-2) would alter proliferation and differentiation of satellite cells isolated from young horses. Fourteen horses were divided into 3 age groups: weanlings ( = 5), yearlings to 2 yr olds ( = 4), and 3 to 4 yr olds ( = 5). The area, height, and subcutaneous fat depth of the LM were measured using ultrasonography, and BW and BCS were taken in October (Fall1), April (Spring), and October of the following year (Fall2). Satellite cells obtained from 10-d-old foals ( = 4) were cultured in the presence of IL-6, IL-1β, TNF-α, IGF-I, or FGF-2 before evaluation of proliferation and differentiation. Data were analyzed using PROC MIXED in SAS. Body weight increased from Fall1 to Spring in weanlings ( < 0.001) and increased in all horses from Spring to Fall2 ( ≤ 0.02). Area and height of the LM increased over time ( < 0.001) and with increasing age group of horse ( ≤ 0.03), although there was no interaction of time and age ( > 0.61). There was a significant increase in LM area in all animals from Spring to Fall2 ( < 0.001) but not from Fall1 to Spring. Interleukin-6 and TNF-α decreased satellite cell proliferation by 14.9 and 11.5%, respectively ( ≤ 0.01). Interleukin-6 increased fusion 6.2%, whereas TNF-α decreased fusion 8.7% compared with control cells ( ≤ 0.001). Interleukin-1β had no effect on proliferation ( = 0.32) but tended to decrease fusion ( = 0.06). Satellite cell proliferation was increased 28.8 and 73.0% by IGF-I and FGF-2, respectively ( < 0.0001). Differentiation was decreased 13.1% in the presence of FGF-2 but increased 3.5% in the presence of IGF-I ( ≤ 0.01). In summary, the LM area increases over the course of a year in young horses with the most growth occurring in summer. By stimulating or inhibiting proliferation and differentiation of satellite cells, IL-6, TNF-α, IL-1β, IGF-I, and FGF-2 may alter muscle growth in young horses, thereby impacting athletic potential.
Collapse
|
26
|
Lightfoot AP, Sakellariou GK, Nye GA, McArdle F, Jackson MJ, Griffiths RD, McArdle A. SS-31 attenuates TNF-α induced cytokine release from C2C12 myotubes. Redox Biol 2015; 6:253-259. [PMID: 26291279 PMCID: PMC4556772 DOI: 10.1016/j.redox.2015.08.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 08/07/2015] [Indexed: 02/08/2023] Open
Abstract
TNF-α is a key inflammatory mediator and is proposed to induce transcriptional responses via the mitochondrial generation of Reactive Oxygen Species (ROS). The aim of this study was to determine the effect of TNF-α on the production of myokines by skeletal muscle. Significant increases were seen in the release of IL-6, MCP-1/CCL2, RANTES/CCL5 and KC/CXCL1 and this release was inhibited by treatment with Brefeldin A, suggesting a golgi-mediated release of cytokines by muscle cells. An increase was also seen in superoxide in response to treatment with TNF-α, which was localised to the mitochondria and this was also associated with activation of NF-κB. The changes in superoxide, activation of NF-kB and release of myokines were attenuated following pre-treatment with SS-31 peptide indicating that the ability of TNF-α to induce myokine release may be mediated through mitochondrial superoxide, which is, at least in part, associated with activation of the redox sensitive transcription factor NF-kB.
Collapse
Affiliation(s)
- Adam P Lightfoot
- MRC-Arthritis UK Centre for Integrated Research into Musculoskeletal Ageing, University of Liverpool, United Kingdom
| | - Giorgos K Sakellariou
- MRC-Arthritis UK Centre for Integrated Research into Musculoskeletal Ageing, University of Liverpool, United Kingdom
| | - Gareth A Nye
- MRC-Arthritis UK Centre for Integrated Research into Musculoskeletal Ageing, University of Liverpool, United Kingdom
| | - Francis McArdle
- MRC-Arthritis UK Centre for Integrated Research into Musculoskeletal Ageing, University of Liverpool, United Kingdom
| | - Malcolm J Jackson
- MRC-Arthritis UK Centre for Integrated Research into Musculoskeletal Ageing, University of Liverpool, United Kingdom
| | - Richard D Griffiths
- MRC-Arthritis UK Centre for Integrated Research into Musculoskeletal Ageing, University of Liverpool, United Kingdom
| | - Anne McArdle
- MRC-Arthritis UK Centre for Integrated Research into Musculoskeletal Ageing, University of Liverpool, United Kingdom.
| |
Collapse
|
27
|
Seto DN, Kandarian SC, Jackman RW. A Key Role for Leukemia Inhibitory Factor in C26 Cancer Cachexia. J Biol Chem 2015; 290:19976-86. [PMID: 26092726 DOI: 10.1074/jbc.m115.638411] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Indexed: 12/23/2022] Open
Abstract
Cachexia is an exacerbating event in many types of cancer that is strongly associated with a poor prognosis. We have identified cytokine, signaling, and transcription factors that are required for cachexia in the mouse C26 colon carcinoma model of cancer. C2C12 myotubes treated with conditioned medium from C26 cancer cells induced atrophy and activated a STAT-dependent reporter gene but not reporter genes dependent on SMAD, FOXO, C/EBP, NF-κB, or AP-1. Of the gp130 family members IL-11, IL-6, oncostatin M (OSM), and leukemia inhibitory factor (LIF), only OSM and LIF were sufficient to activate the STAT reporter in myotubes. LIF was elevated in C26 conditioned medium (CM), but IL-6, OSM, TNFα, and myostatin were not. A LIF-blocking antibody abolished C26 CM-induced STAT reporter activation, STAT3 phosphorylation, and myotube atrophy but blocking antibodies to IL-6 or OSM did not. JAK2 inhibitors also blocked C26 CM-induced STAT reporter activation, STAT3 phosphorylation, and atrophy in myotubes. LIF at levels found in the C26 CM was sufficient for STAT reporter activation and atrophy in myotubes. In vivo, an increase in serum LIF preceded the increase in IL-6 in mice with C26 tumors. Overexpression of a dominant negative Stat3Cβ-EGFP gene in myotubes and in mouse muscle blocked the atrophy caused by C26 CM or C26 tumors, respectively. Taken together, these data support an important role of LIF-JAK2-STAT3 in C26 cachexia and point to a therapeutic approach for at least some types of cancer cachexia.
Collapse
Affiliation(s)
- Danielle N Seto
- From the Department of Health Sciences, Boston University, Boston, Massachusetts 02215
| | - Susan C Kandarian
- From the Department of Health Sciences, Boston University, Boston, Massachusetts 02215
| | - Robert W Jackman
- From the Department of Health Sciences, Boston University, Boston, Massachusetts 02215
| |
Collapse
|
28
|
Krüger K, Dischereit G, Seimetz M, Wilhelm J, Weissmann N, Mooren FC. Time course of cigarette smoke-induced changes of systemic inflammation and muscle structure. Am J Physiol Lung Cell Mol Physiol 2015; 309:L119-28. [PMID: 26001775 DOI: 10.1152/ajplung.00074.2015] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 05/14/2015] [Indexed: 11/22/2022] Open
Abstract
It has become more evident that long-term cigarette smoking (LTCS) has an important extrapulmonary toxicity. The aim of the study was to investigate the time-dependent effects of cigarette smoke exposure on exercise capacity, markers of systemic inflammation, and skeletal muscle structure. c57bl/6j-mice were either exposed to mainstream cigarette smoke for 6 h/day, 5 days/wk [smoke-exposed (SE) group] or assigned to the control, unexposed group (Con group). SE group mice were exposed for 8, 16, 24, and 32 wk to smoke and unexposed Con mice were used as age-matched controls. Exercise capacity was investigated by spiroergometry. Systemic inflammatory status was analyzed by flow cytometry and multiplexed fluorescent immunoassay. For analysis of muscle tissue, histological techniques and microarray analysis were used. Mice of the SE group exhibited a lower increase of body mass and a decrease of V̇o2 max (P < 0.05). An increase of lymphocyte CD62, ICAM, and VCAM expression was found in SE mice (P < 0.05). A biphasic trend of protein up- and downregulation was observed in markers of systemic inflammation, tissue deterioration, and allergic reactions such as C-reactive protein (CRP), eotaxin, haptoglobin, macrophage colony-stimulating factor-1 (M-CSF-1), and macrophage inflammatory protein-1γ (MIP-1γ). Thereby, the expression of several chemotactic proteins in plasma correlated with their expression in muscle. A time-dependent decrease of muscle mass, oxidative type-I fibers, and muscle cross-sectional area was found (P < 0.05). Microarray analysis revealed a SE-induced upregulation of several pathways of metabolic processes and tissue degradation. Taken together it was found that the loss of exercise capacity and systemic inflammation are early events of SE, which might induce muscular atrophy and loss of oxidative muscle capacity.
Collapse
Affiliation(s)
- K Krüger
- Department of Sports Medicine, Justus Liebig-University Giessen, Giessen, Germany; and
| | - G Dischereit
- Department of Sports Medicine, Justus Liebig-University Giessen, Giessen, Germany; and
| | - M Seimetz
- Excellence Cluster Cardio-Pulmonary System, Universities of Giessen and Marburg Lung Center, Member of the German Center for Lung Research, Giessen, Germany
| | - J Wilhelm
- Excellence Cluster Cardio-Pulmonary System, Universities of Giessen and Marburg Lung Center, Member of the German Center for Lung Research, Giessen, Germany
| | - N Weissmann
- Excellence Cluster Cardio-Pulmonary System, Universities of Giessen and Marburg Lung Center, Member of the German Center for Lung Research, Giessen, Germany
| | - F C Mooren
- Department of Sports Medicine, Justus Liebig-University Giessen, Giessen, Germany; and
| |
Collapse
|
29
|
Abstract
Atrophy occurs in specific muscles with inactivity (for example, during plaster cast immobilization) or denervation (for example, in patients with spinal cord injuries). Muscle wasting occurs systemically in older people (a condition known as sarcopenia); as a physiological response to fasting or malnutrition; and in many diseases, including chronic obstructive pulmonary disorder, cancer-associated cachexia, diabetes, renal failure, cardiac failure, Cushing syndrome, sepsis, burns and trauma. The rapid loss of muscle mass and strength primarily results from excessive protein breakdown, which is often accompanied by reduced protein synthesis. This loss of muscle function can lead to reduced quality of life, increased morbidity and mortality. Exercise is the only accepted approach to prevent or slow atrophy. However, several promising therapeutic agents are in development, and major advances in our understanding of the cellular mechanisms that regulate the protein balance in muscle include the identification of several cytokines, particularly myostatin, and a common transcriptional programme that promotes muscle wasting. Here, we discuss these new insights and the rationally designed therapies that are emerging to combat muscle wasting.
Collapse
|
30
|
Doig CL, Bashir J, Zielinska AE, Cooper MS, Stewart PM, Lavery GG. TNFα-mediated Hsd11b1 binding of NF-κB p65 is associated with suppression of 11β-HSD1 in muscle. J Endocrinol 2014; 220:389-96. [PMID: 24413279 PMCID: PMC4027025 DOI: 10.1530/joe-13-0494] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The activity of the enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), which converts inactive cortisone (11-dehydrocorticosterone (11-DHC)) (in mice) into the active glucocorticoid (GC) cortisol (corticosterone in mice), can amplify tissue GC exposure. Elevated TNFα is a common feature in a range of inflammatory disorders and is detrimental to muscle function in diseases such as rheumatoid arthritis and chronic obstructive pulmonary disease. We have previously demonstrated that 11β-HSD1 activity is increased in the mesenchymal stromal cells (MSCs) by TNFα treatment and suggested that this is an autoregulatory anti-inflammatory mechanism. This upregulation was mediated by the P2 promoter of the Hsd11b1 gene and was dependent on the NF-κB signalling pathway. In this study, we show that in contrast to MSCs, in differentiated C2C12 and primary murine myotubes, TNFα suppresses Hsd11b1 mRNA expression and activity through the utilization of the alternative P1 promoter. As with MSCs, in response to TNFα treatment, NF-κB p65 was translocated to the nucleus. However, ChIP analysis demonstrated that the direct binding was seen at position -218 to -245 bp of the Hsd11b1 gene's P1 promoter but not at the P2 promoter. These studies demonstrate the existence of differential regulation of 11β-HSD1 expression in muscle cells through TNFα/p65 signalling and the P1 promoter, further enhancing our understanding of the role of 11β-HSD1 in the context of inflammatory disease.
Collapse
|
31
|
Cornwell EW, Mirbod A, Wu CL, Kandarian SC, Jackman RW. C26 cancer-induced muscle wasting is IKKβ-dependent and NF-kappaB-independent. PLoS One 2014; 9:e87776. [PMID: 24489962 PMCID: PMC3906224 DOI: 10.1371/journal.pone.0087776] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 12/30/2013] [Indexed: 12/24/2022] Open
Abstract
Existing data suggest that NF-kappaB signaling is a key regulator of cancer-induced skeletal muscle wasting. However, identification of the components of this signaling pathway and of the NF-κB transcription factors that regulate wasting is far from complete. In muscles of C26 tumor bearing mice, overexpression of dominant negative (d.n.) IKKβ blocked muscle wasting by 69% and the IκBα-super repressor blocked wasting by 41%. In contrast, overexpression of d.n. IKKα or d.n. NIK did not block C26-induced wasting. Surprisingly, overexpression of d.n. p65 or d.n. c-Rel did not significantly affect muscle wasting. Genome-wide mRNA expression arrays showed upregulation of many genes previously implicated in muscle atrophy. To test if these upregulated genes were direct targets of NF-κB transcription factors, we compared genome-wide p65 binding to DNA in control and cachectic muscle using ChIP-sequencing. Bioinformatic analysis of ChIP-sequencing data from control and C26 muscles showed very little p65 binding to genes in cachexia and little to suggest that upregulated p65 binding influences the gene expression associated with muscle based cachexia. The p65 ChIP-seq data are consistent with our finding of no significant change in protein binding to an NF-κB oligonucleotide in a gel shift assay, no activation of a NF-κB-dependent reporter, and no effect of d.n.p65 overexpression in muscles of tumor bearing mice. Taken together, these data support the idea that although inhibition of IκBα, and particularly IKKβ, blocks cancer-induced wasting, the alternative NF-κB signaling pathway is not required. In addition, the downstream NF-κB transcription factors, p65 and c-Rel do not appear to regulate the transcriptional changes induced by the C26 tumor. These data are consistent with the growing body of literature showing that there are NF-κB-independent substrates of IKKβ and IκBα that regulate physiological processes.
Collapse
Affiliation(s)
- Evangeline W. Cornwell
- Department of Health Sciences, Boston University, Boston, Massachusetts, United States of America
| | - Azadeh Mirbod
- Department of Health Sciences, Boston University, Boston, Massachusetts, United States of America
| | - Chia-Ling Wu
- Department of Health Sciences, Boston University, Boston, Massachusetts, United States of America
| | - Susan C. Kandarian
- Department of Health Sciences, Boston University, Boston, Massachusetts, United States of America
| | - Robert W. Jackman
- Department of Health Sciences, Boston University, Boston, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
32
|
Sato S, Ogura Y, Kumar A. TWEAK/Fn14 Signaling Axis Mediates Skeletal Muscle Atrophy and Metabolic Dysfunction. Front Immunol 2014; 5:18. [PMID: 24478779 PMCID: PMC3902304 DOI: 10.3389/fimmu.2014.00018] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 01/14/2014] [Indexed: 01/07/2023] Open
Abstract
Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) through binding to its receptor fibroblast growth factor inducible 14 (Fn14) has been shown to regulate many cellular responses including proliferation, differentiation, apoptosis, inflammation, and fibrosis, under both physiological and pathological conditions. Emerging evidence suggests that TWEAK is also a major muscle wasting cytokine. TWEAK activates nuclear factor-κB signaling and proteolytic pathways such as ubiquitin–proteasome system, autophagy, and caspases to induce muscle proteolysis in cultured myotubes. Fn14 is dormant or expressed in minimal amounts in normal healthy muscle. However, specific atrophic conditions, such as denervation, immobilization, and starvation stimulate the expression of Fn14 leading to activation of TWEAK/Fn14 signaling and eventually skeletal muscle atrophy. TWEAK also causes slow- to fast-type fiber transition in skeletal muscle. Furthermore, recent studies suggest that TWEAK diminishes mitochondrial content and represses skeletal muscle oxidative phosphorylation capacity. TWEAK mediates these effects through affecting the expression of a number of genes and microRNAs. In this review article, we have discussed the recent advancements toward understanding the role and mechanisms of action of TWEAK/Fn14 signaling in skeletal muscle with particular reference to different models of atrophy and oxidative metabolism.
Collapse
Affiliation(s)
- Shuichi Sato
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine , Louisville, KY , USA
| | - Yuji Ogura
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine , Louisville, KY , USA
| | - Ashok Kumar
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine , Louisville, KY , USA
| |
Collapse
|
33
|
Urban RJ, Dillon EL, Choudhary S, Zhao Y, Horstman AM, Tilton RG, Sheffield-Moore M. Translational studies in older men using testosterone to treat sarcopenia. TRANSACTIONS OF THE AMERICAN CLINICAL AND CLIMATOLOGICAL ASSOCIATION 2014; 125:27-42; discussion 42-4. [PMID: 25125716 PMCID: PMC4112698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Sarcopenia is the loss of skeletal muscle mass and strength that occurs with aging. Our research group has found an efficacious administration paradigm using testosterone to combat sarcopenia in humans. In addition, our research has uncovered an important regulatory enzyme of inflammation, nuclear factor-κB-inducing kinase that may regulate human skeletal muscle catabolism, and that appears to be counter-regulated by administration of standard doses of testosterone. This is important because a number of age-related clinical circumstances trigger acute and chronic muscle loss including cancer, chronic obstructive pulmonary disease, hospitalization, acute and chronic illness, and diseases in which systemic inflammation occurs. Moreover, it is often the treatment itself that can induce muscle loss. For example, glucocorticoids are tremendously effective at reducing inflammation and are a frontline therapy for many inflammatory-based diseases, yet paradoxically trigger muscle loss. We will discuss our research findings and the clinical significance of our human clinical translational research with testosterone.
Collapse
|
34
|
Song Y, Karisnan K, Noble PB, Berry CA, Lavin T, Moss TJM, Bakker AJ, Pinniger GJ, Pillow JJ. In utero LPS exposure impairs preterm diaphragm contractility. Am J Respir Cell Mol Biol 2013; 49:866-74. [PMID: 23795611 DOI: 10.1165/rcmb.2013-0107oc] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Preterm birth is associated with inflammation of the fetal membranes (chorioamnionitis). We aimed to establish how chorioamnionitis affects the contractile function and phenotype of the preterm diaphragm. Pregnant ewes received intra-amniotic injections of saline or 10 mg LPS, 2 days or 7 days before delivery at 121 days of gestation (term = 150 d). Diaphragm strips were dissected for the assessment of contractile function after terminal anesthesia. The inflammatory cytokine response, myosin heavy chain (MHC) fibers, proteolytic pathways, and intracellular molecular signaling were analyzed using quantitative PCR, ELISA, immunofluorescence staining, biochemical assays, and Western blotting. Diaphragm peak twitch force and maximal tetanic force were approximately 30% lower than control values in the 2-day and 7-day LPS groups. Activation of the NF-κB pathway, an inflammatory response, and increased proteasome activity were observed in the 2-day LPS group relative to the control or 7-day LPS group. No inflammatory response was evident after a 7-day LPS exposure. Seven-day LPS exposure markedly decreased p70S6K phosphorylation, but no effect on other signaling pathways was evident. The proportion of MHC IIa fibers was lower than that for control samples in the 7-day LPS group. MHC I fiber proportions did not differ between groups. These results demonstrate that intrauterine LPS impairs preterm diaphragmatic contractility after 2-day and 7-day exposures. Diaphragm dysfunction, resulting from 2-day LPS exposure, was associated with a transient activation of proinflammatory signaling, with subsequent increased atrophic gene expression and enhanced proteasome activity. Persistently impaired contractility for the 7-day LPS exposure was associated with the down-regulation of a key component of the protein synthetic signaling pathway and a reduction in the proportions of MHC IIa fibers.
Collapse
Affiliation(s)
- Yong Song
- 1 School of Anatomy, Physiology, and Human Biology, and
| | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Jackman RW, Cornwell EW, Wu CL, Kandarian SC. Nuclear factor-κB signalling and transcriptional regulation in skeletal muscle atrophy. Exp Physiol 2012; 98:19-24. [PMID: 22848079 DOI: 10.1113/expphysiol.2011.063321] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The nuclear factor-κB (NF-κB) signalling pathway is a necessary component of adult skeletal muscle atrophy resulting from systemic illnesses or disuse. Studies showing a role for the NF-κB pathway in muscle disuse include unloading, denervation and immobilization, and studies showing a role for NF-κB in systemic illnesses include cancer, chronic heart failure and acute septic lung injury. Muscle atrophy due to most of these triggers is associated with activation of NF-κB transcriptional activity. With the exception of muscle unloading, however, there is a paucity of data on the NF-κB transcription factors that regulate muscle atrophy, and little is known about which genes are targeted by NF-κB transcription factors during atrophy. Interestingly, in some cases it appears that the amelioration of muscle atrophy by genetic inhibition of NF-κB signalling proteins is due to effects that are independent of the downstream NF-κB transcription factors. These questions are prime areas for investigation if we are to understand a key component of muscle wasting in adult skeletal muscle.
Collapse
Affiliation(s)
- Robert W Jackman
- Boston University, Department of Health Sciences, 635 Commonwealth Avenue, Boston, MA 02215, USA
| | | | | | | |
Collapse
|