Bax-regulated mitochondria-mediated apoptosis is responsible for the in vitro ischemia induced neuronal cell death of Sprague Dawley rat.
An in vitro ischemia model was used to determine the molecular mechanisms responsible for the ischemia-induced neuronal cell death. Additionally, the neuronal protective mechanisms of anti-apoptotic drugs against ischemia were also evaluated. In this study, the primary neuronal cultures were incubated in an anoxic chamber with 95% of N2 and 5% of CO2 for various times. The death rate, degree of the apoptotic damage, reduction of mitochondrial membrane potential, translocation of Bax, release of cytochrome C and activation of caspase-9 and -3 were determined at each time point. Results showed that a Bax-regulated mitochondria- mediated apoptosis is responsible for the in vitro ischemia-induced neuronal death. Reduction in mitochondrial membrane potential plays no role in triggering this apoptosis. Furthermore, the anti-apoptotic drugs: furosemide (a Bax blocker) and ZVAD-fmk (caspase inhibitor) but not cyclosporine A (a MPT pore blocker), significantly protected the neurons against ischemia-induced damage. This provides an additional consideration in the future selection of new anti-ischemic drugs.
Lin
Chi-Hsin
CH
Department of Life Sciences, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 40227, Taiwan.
Lu
Yen-Zhen
YZ
Cheng
Fu-Chou
FC
Chu
Lan-Feng
LF
Hsueh
Chi-Mei
CM
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D002545:Brain Ischemia / Q000378:metabolism* / Q000503:physiopathology; D020169:Caspases / Q000187:drug effects / Q000378:metabolism; D002544:Cerebral Infarction / Q000378:metabolism / Q000503:physiopathology; D045304:Cytochromes c / Q000187:drug effects / Q000378:metabolism; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007425:Intracellular Membranes / Q000187:drug effects / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D009410:Nerve Degeneration / Q000378:metabolism* / Q000503:physiopathology; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D021381:Protein Transport / Q000187:drug effects / Q000502:physiology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D051028:bcl-2-Associated X Protein
C494828:Bax protein, rat; D004791:Enzyme Inhibitors; D011500:Protein Synthesis Inhibitors; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D045304:Cytochromes c; D020169:Caspases