凋亡因子在缺氧缺水缺食致心脏损伤中作用

Role of apoptosis factors in heart injury induced by hypoxia combined with water and dietary depletion in rats

目的探讨凋亡相关因子Bax、Bcl-2、细胞色素C和caspase-3在缺氧缺水缺食条件下大鼠心肌细胞损伤中变化及其意义。方法将80只Wistar大鼠置于常压低氧舱（10%氧浓度）并禁食水,于实验1、3、5、7 d,采用原位末端标记、免疫组织化学和原位杂交技术等方法,检测缺氧缺水缺食后心脏凋亡指数变化及凋亡相关因子Bax、Bcl-2、细胞色素C和caspase-3在其中的作用。结果 10%缺氧复合缺水缺食后1 d和7 d大鼠心肌细胞凋亡指数（62.63±14.97）、（20.19±3.26）增加;Bax、细胞色素C和caspase-3蛋白在单纯缺氧和缺氧缺水缺食后均可见1~7 d表达增加,缺水缺食后在3~7 d表达增加。Bcl-2在单纯缺氧和缺水缺食后1~7 d表达减少,缺氧缺水缺食后1~3 d表达减少;Caspase-3 mRNA在单纯缺氧组和缺氧缺水缺食后1 d（4.19±1.42）、（3.87±0.86）和7 d（10.43±2.79）、（12.12±2.27）表达增加,缺水缺食后1 d（3.85±0.88）表达增加。结论 10%缺氧复合缺水缺食可引起心肌细胞凋亡,与Bax表达增加、Bcl-2表达减少有关;可能进一步通过线粒体途径,释放细胞色素C,激活caspase-3,引发心肌细胞凋亡。

Objective To investigate the change of apoptosis factors Bax,Bcl-2,cytochrome C,and caspase-3 and their role in the mechanism of myocardial cells injury under hypoxia combined with water and dietary depletion in rats.Methods Eighty wistar rats were placed in a self-designed normobaric hypoxic chamber with the oxygen concentration of 10%.In situ cell apoptosis detection,immunochemistry and in situ hybridization were used to detect the change of apoptosis index of myocardial cells and the expressions of Bax,Bcl-2,cytochrome C,and caspase-3 in the process at 1st,3rd,5th,and 7th day after the treatment.Results The apoptosis index of myocardial cells was increased at 1st and 7th day under the condition（62.63±14.97,20.19±3.26）.The expressions of Bax,cytochrome C,and caspase-3 were increased from 1st to 7th day in hypoxia group and hypoxia combined with water and dietary depletion group,and from 3rd to 7th day for water and dietary depletion group.The expression of Bcl-2 was reduced from 1st to 7th day in hypoxia group and water and dietary depletion group and from 3rd to 7th day in hypoxia combined with water and dietary depletion group.The mRNA of caspase-3 was increased at 1st day（4.19±1.42,3.87±0.86） and 7th day（10.43±2.79,12.12±2.27） in hypoxia group and hypoxia combined with water and dietary depletion group,and at 1st day in water and dietary depletion group（3.85±0.88）.Conclusion The hypoxia of 10% oxygen concentration combined with water and dietary depletion could result in apoptosis of myocardial cells which was correlated with the increase of promoting apoptotic factor（Bax） and the decrease of anti-apoptotic factor（Bcl-2）.Furthermore,it might result in release of cytochrome C by mitochondria pathway,activation of caspase-3,and apoptosis of myocardial cells.