Mitochondrial dysfunction-associated OPA1 cleavage contributes to muscle degeneration: preventative effect of hydroxytyrosol acetate.
Mitochondrial dysfunction contributes to the development of muscle disorders, including muscle wasting, muscle atrophy and degeneration. Despite the knowledge that oxidative stress closely interacts with mitochondrial dysfunction, the detailed mechanisms remain obscure. In this study, tert-butylhydroperoxide (t-BHP) was used to induce oxidative stress on differentiated C2C12 myotubes. t-BHP induced significant mitochondrial dysfunction in a time-dependent manner, accompanied by decreased myosin heavy chain (MyHC) expression at both the mRNA and protein levels. Consistently, endogenous reactive oxygen species (ROS) overproduction triggered by carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone (FCCP), a mitochondrial oxidative phosphorylation inhibitor, was accompanied by decreased membrane potential and decreased MyHC protein content. However, the free radical scavenger N-acetyl-L-cysteine (NAC) efficiently reduced the ROS level and restored MyHC content, suggesting a close association between ROS and MyHC expression. Meanwhile, we found that both t-BHP and FCCP promoted the cleavage of optic atrophy 1 (OPA1) from the long form into short form during the early stages. In addition, the ATPase family gene 3-like 2, a mitochondrial inner membrane protease, was also markedly increased. Moreover, OPA1 knockdown in myotubes was accompanied by decreased MyHC content, whereas NAC failed to prevent FCCP-induced MyHC decrease with OPA1 knockdown, suggesting that ROS might affect MyHC content by modulating OPA1 cleavage. In addition, hydroxytyrosol acetate (HT-AC), an important compound in virgin olive oil, could significantly prevent t-BHP-induced mitochondrial membrane potential and cell viability loss in myotubes. Specifically, HT-AC inhibited t-BHP-induced OPA1 cleavage and mitochondrial morphology changes, accompanied by improvement on mitochondrial oxygen consumption capacity, ATP productive potential and activities of mitochondrial complex I, II and V. Moreover, both t-BHP- and FCCP-induced MyHC decrease was sufficiently inhibited by HT-AC. Taken together, our data provide evidence indicating that mitochondrial dysfunction-associated OPA1 cleavage may contribute to muscle degeneration, and olive oil compounds could be effective nutrients for preventing the development of muscle disorders.
Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China.
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Wang
Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China.
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Li
Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China.
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Zheng
Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China.
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Yang
Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China.
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Liu
Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China.
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Chen
Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China.
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Tang
Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China.
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Zou
Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China.
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Li
Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China.
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Long
1] Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China [2] Tianjin Key Laboratory of Exercise Physiology & Sports Medicine, Tianjin University of Sport, Tianjin 300381, China.
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Liu
Tianjin Key Laboratory of Exercise Physiology & Sports Medicine, Tianjin University of Sport, Tianjin 300381, China.
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Zhang
Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China.
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Feng
D000085:Acetates / Q000302:isolation & purification / Q000494:pharmacology*; D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000037:antagonists & inhibitors / Q000494:pharmacology; D002396:Catechols / Q000302:isolation & purification / Q000494:pharmacology*; D002454:Cell Differentiation; D042967:Electron Transport Complex I / Q000235:genetics / Q000378:metabolism; D042963:Electron Transport Complex II / Q000235:genetics / Q000378:metabolism; D020558:GTP Phosphohydrolases / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051379:Mice; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D018485:Muscle Fibers, Skeletal / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D032446:Myoblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D018995:Myosin Heavy Chains / Q000235:genetics* / Q000378:metabolism; D000069463:Olive Oil; D018384:Oxidative Stress; D010938:Plant Oils / Q000737:chemistry; D059748:Proteolysis; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors / Q000378:metabolism; D020122:tert-Butylhydroperoxide / Q000037:antagonists & inhibitors / Q000494:pharmacology
D000085:Acetates; D002396:Catechols; D000069463:Olive Oil; D010938:Plant Oils; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; C524604:hydroxytyrosyl acetate; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D020122:tert-Butylhydroperoxide; D042963:Electron Transport Complex II; D020558:GTP Phosphohydrolases; C498809:Opa1 protein, mouse; D018995:Myosin Heavy Chains; D042967:Electron Transport Complex I; D000111:Acetylcysteine