急性一氧化碳中毒小鼠脑海马细胞凋亡及bcl-2、Bax和caspase-3蛋白表达

目的研究急性一氧化碳中毒(ACOP)后脑海马细胞凋亡和bcl-2、Bax、caspase-3蛋白表达的变化。方法雄性昆明小鼠56只随机分为7组(对照组、ACOP后1h,6h,12h,24h,3d,7d组),每组8只,对照组暴露于空气中,中毒组暴露于一氧化碳(CO)气体中,于相应时间点断头取脑。采用TUNEL、免疫组化法和流式细胞仪观察ACOP后细胞凋亡和caspase-3、bcl-2、Bax蛋白表达的变化。结果ACOP后3d小鼠脑海马凋亡细胞明显增加(P<0.05),第7天达最高(P<0.01);caspase-3蛋白在ACOP后1h表达增加,第3天达到高峰,第7天降至正常;bcl-2蛋白在中毒后1h海马区表达增多,24h达到高峰,第7天大致正常;Bax蛋白在CO中毒1h表达增多,24h达高峰,第7天大致正常。结论ACOP后小鼠脑海马出现迟发的神经元凋亡及凋亡相关因子表达,细胞凋亡可能参与了ACOP迟发脑病的发病机制。

Brain hippocampus cellular apoptosis and changes of the expression of bcl-2, Bax, caspase-3 protein in mice after acute cabon monoxide poisoning

Objective To study changes of apoptotic cells and the expression of bcl-2, Bax and caspase-3 in mice brain hippocampus after acute carbon monoxide poisoning(ACOP). Methods 56 male KunMing mice were divided into seven groups (control group, CO-exposed for 1 h group, CO-exposed for 6 h group, CO-exposed for 12 h group, CO-exposed for 24 h group, CO-exposed for 3 d group and CO-exposed for 7 d group), and eight mice in each group. The control group were exposed to air and the poisoned groups were exposed to CO. General TUNEL, immunohistochemistry stain and flow cytometry were used to observe the neurological damage and changes of caspase-3, bcl-2, Bax protein expression. Results TUNEL staining positive cells significantly increased on the 3rd day in hippocampus after acute CO poisoning (P<0.05), and reached the highest value on the 7th day (P<0.01); caspase-3 protein expression increased at 1 h after poisoning, reached the highest level at 24 h after poisoning and recovered to normal on the 7th day; bcl-2 protein expression increased in hippocampus at 1 h after acute CO poisoning, and peaked at 24 h and recovered to nomal on the 7th day ; Bax protein expression increased in hippocampus at 1 h after poisoning, and peaked at 24 h and recovered to nomal on the 7th day. Conclusions Delayed neurological apoptosis and the expression of apoptosis-associated factors were observed in mice brain hippocampus after acute CO poisoning. Celluar apoptosis might be one of the pathological mechanism of delayed encephalopathy after acute carbon monoxide poisoning.