Underlying mechanism of hypoxic preconditioning decreasing apoptosis induced by anoxia in cultured hippocampal neurons.
It is known that hypoxic preconditioning (HP, a brief period of sublethal hypoxia) provides neuroprotection against subsequent severe anoxia, but the mechanisms of this increased tolerance have not been fully elucidated. A hypoxic preconditioning model was established by exposing a 4-day hippocampal culture to 1% O(2) for 20 min/day for 8 days. The preconditioning significantly decreased the number of apoptotic neurons at reoxygenation 24 h after 4 h of severe anoxia (0% O(2)). Further study demonstrated that the degradation of mitochondrial membrane potential (MMP) was greatly inhibited and the expression of B-cell lymphoma protein-2 (Bcl-2) was increased considerably after severe anoxia in the HP groups. These results indicate that the increased anoxic tolerance, which is induced by HP in cultured hippocampal cells, may be correlated with Bcl-2 overexpression and enhanced stability of MMP, which ultimately reduces apoptosis 24 h after reoxygenation.
Wu
Li-ying
LY
Department of Neurobiology, Institute of Basic Medical Sciences, Beijing, PR China.
Ding
Ai-shi
AS
Zhao
Tong
T
Ma
Zi-min
ZM
Wang
Fu-zhuang
FZ
Fan
Ming
M
D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000502:physiology*; D002452:Cell Count / Q000379:methods; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D005434:Flow Cytometry / Q000379:methods; D006624:Hippocampus / Q000166:cytology*; D000860:Hypoxia / Q000503:physiopathology*; D007150:Immunohistochemistry / Q000379:methods; D020287:In Situ Nick-End Labeling / Q000379:methods; D019194:Ischemic Preconditioning / Q000379:methods*; D008564:Membrane Potentials / Q000502:physiology; D018613:Microscopy, Confocal / Q000379:methods; D008928:Mitochondria / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
D019253:Proto-Oncogene Proteins c-bcl-2