title: Attenuating ischemia-induced H9c2 myoblasts apoptosis by therapeutic hypothermia.
abstract: Although inducing mild hypothermia (32 degrees C) in animal models of cardiac arrest with highly attenuated cardiac and neurological injury, the protective effects of hypothermia molecular mechanisms were not fully elucidated, and thus, were examined here on the H9c2 rat ventricular myoblasts that underwent cell loss as well as apoptosis in conditions of simulated ischemia, represented by serum withdrawal plus hypoxia. The H9c2 cells apoptosis was evidenced by flow cytometry-, DNA fragmentation-, and caspase 3 activation-increased apoptotic cells (Annexin-V positive and propidium iodide negative). For the simulated ischemia, both cell loss and apoptosis of these cardiomyoblasts were associated with downregulated small molecular weight proteins (heat shock protein 20, heat shock protein 27, and alphaB-crystallin). Mild hypothermia significantly reduced the ischemia-induced apoptosis, small molecular weight proteins downregulation, and cell viability cut. Conclusively, hypothermia may inhibit simulated ischemia-induced apoptosis in cardiomyocytes by restoring normal small molecular weight proteins expression.
authors.affiliation: Graduate Institute of Clinical Medicine and Department of Surgery, National Taiwan University School of Medicine, Taipei, Taiwan.
authors.forename: Cheng-Hsin
authors.initials: CH
authors.lastname: Lin
authors.forename: Wen-Shiann
authors.initials: WS
authors.lastname: Wu
authors.forename: Mao-Tsun
authors.initials: MT
authors.lastname: Lin
authors.forename: Wen-Ping
authors.initials: WP
authors.lastname: Liu
authors.forename: Ron-Bin
authors.initials: RB
authors.lastname: Hsu
authors.forename: Ching-Ping
authors.initials: CP
authors.lastname: Chang
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D015687:Cell Hypoxia / Q000502:physiology; D002460:Cell Line; D002470:Cell Survival / Q000502:physiology; D053938:DNA Fragmentation; D007036:Hypothermia, Induced / Q000009:adverse effects; D032446:Myoblasts / Q000378:metabolism* / Q000473:pathology; D051381:Rats