Role of mitochondrial fission in anoxia-reoxygenation injury to rat hippocampal neurons / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the role of mitochondrial fission in anoxia-reoxygenation injury to rat hippocampal neurons.Methods Neurons were enzymatically isolated from hippocampi of newborn Sprague-Dawley rats (less than 24 h old).The primary hippocampal neurons were cultured and seeded in 25 mm × 25 mm culture flasks at a density of 7 × 105/ml.The cultured neurons were randomly assigned into 3 groups (n =18 each) using a random number tablecontrol group (C group),anoxia-reoxygenation group (I/R group),and mitochondrial fission inhibitor mdivi-1 group (M group).In group I/R,the vehicle dimethyl sulfoxide (DMSO,final concentration ＜ 0.1％) was added prior to anoxia and the cells were then incubated for 40 min.In group M,mdivi-1 (dissolved in DMSO,final concentration of DMSO ＜ 0.1％) was added prior to anoxia and the cells were then incubated for 40 min.The hippocampal neurons were subjected to oxygen-glucose deprivation (OGD) for 6 h followed by restoration of O2 supply for 20 h.After 20 h of reoxygenation,the level of reactive oxygen species (ROS) (by ELISA),cell apoptosis (using flow cytometry),and expression of mitochondrial fission protein Drp1,Bcl-2 and Bax (by Western blot) were measured.The apoptosis rate and the ratio of Bcl-2 to Bax were calculated.Results Compared with C group,ROS content and apoptosis rate were significantly increased,the expression of Drp1 and Bax was up-regulated,the expression of Bcl-2 was down-regulated,and the ratio of Bcl-2 to Bax was decreased in I/R group (P ＜ 0.05).Compared with I/R group,ROS content and apoptosis rate were significantly decreased,the expression of Drp1 and Bax was down-regulated,the expression of Bcl-2 was up-regulated,and the ratio of Bcl-2 to Bax was increased in M group (P ＜ 0.05).Conclusion Mitochondrial fission is involved in anoxia-reoxygenation injury to rat hippocampal neurons via mitochondria-mediated apoptotic pathway.