Mitochondrial chaperone tumour necrosis factor receptor-associated protein 1 protects cardiomyocytes from hypoxic injury by regulating mitochondrial permeability transition pore opening.
Tumour necrosis factor receptor-associated protein 1 (TRAP1) is a mitochondrial chaperone that plays a role in maintaining mitochondrial function and regulating cell apoptosis. The opening of the mitochondrial permeability transition pore (MPTP) is a key step in cell death after hypoxia. However, it is still unclear whether TRAP1 protects cardiomyocytes from hypoxic damage by regulating the opening of the pore. In the present study, primary cultured cardiomyocytes from neonatal rats were used to investigate changes in TRAP1 expression after hypoxia treatment as well as the mechanism and effect of TRAP1 on hypoxic damage. The results obtained showed that TRAP1 expression increased after 1 h of hypoxia and continued to increase for up to 12 h of treatment. Hypoxia caused an increase in cell death and decreased cell viability and mitochondrial membrane potential; overexpressing TRAP1 prevented hypoxia-induced damage to cardiomyocytes. The silencing of TRAP1 induced an increase in cell death and decreased both cell viability and mitochondrial membrane potential in cardiomyocytes under normoxic and hypoxic conditions. Furthermore, cell damage induced by the silencing of TRAP1 was prevented by the mitochondrial permeability transition pore inhibitor, cyclosporin A. These data demonstrate that hypoxia induces an increase in TRAP1 expression in cardiomyocytes, and that TRAP1 plays a protective role by regulating the opening of the mitochondrial permeability transition pore.
Institute of Burn Research, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, Third Military Medical University, Chongqing, China.
Fei
F
Xiang
Yue-Sheng
YS
Huang
Xiao-Hua
XH
Shi
Qiong
Q
Zhang
D000818:Animals; D000831:Animals, Newborn; D015687:Cell Hypoxia; D002469:Cell Separation; D002478:Cells, Cultured; D018841:HSP90 Heat-Shock Proteins; D006352:Heart Ventricles / Q000166:cytology; D000860:Hypoxia / Q000378:metabolism* / Q000473:pathology; D008929:Mitochondria, Heart / Q000378:metabolism*; D033681:Mitochondrial Membrane Transport Proteins / Q000502:physiology*; D000083162:Mitochondrial Permeability Transition Pore; D032383:Myocytes, Cardiac / Q000378:metabolism / Q000502:physiology*; D034741:RNA, Small Interfering / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D047990:TNF Receptor-Associated Factor 1 / Q000502:physiology*; D014162:Transfection
D018841:HSP90 Heat-Shock Proteins; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D034741:RNA, Small Interfering; D047990:TNF Receptor-Associated Factor 1; C549284:TRAP1 protein, rat