全饥饿对脑皮质细胞凋亡及Bcl-2、Bax、Caspase-3表达的影响

Effects of starvation on cerebral cortex cell apoptosis and expressions of Bcl-2,Bax,Caspase-3 in rats

目的研究全饥饿状态下大鼠皮质细胞凋亡相关因子Bcl-2、Bax和Caspase-3表达变化情况。方法雄性成年SD大鼠60只,随机分为6组:正常对照组、饥饿3 d、5 d、7 d、9 d和11 d组。采用TUNEL法检测大鼠皮质神经细胞凋亡情况,RT-PCR法检测皮质细胞凋亡相关因子Bcl-2、Bax、Caspase-3 mRNA的表达情况,Western blot法检测Bcl-2、Bax及Caspase-3蛋白表达。结果与正常对照组比较,饥饿5 d组皮质区凋亡细胞数增多(P<0.05),7 d、9 d、11 d组均明显增多(P<0.01);饥饿5 d、7 d、9 d、11 d组脑皮质中Bax、Caspase-3表达均上调(P<0.05),7 d、9 d、11 d组较为显著(P<0.01);饥饿3 d、5 d、7 d组Bcl-2表达均上调(P<0.01),5 d组表达量最多,饥饿9 d、11 d组Bcl-2表达下降,11 d组明显下降(P<0.01)。结论短期饥饿应激可能有一定的脑保护作用;长期饥饿应激可能通过上调大鼠皮质细胞Bax、Caspase-3的表达,抑制Bcl-2的表达,破坏了Bcl-2/Bax的平衡,进而诱导细胞凋亡。

Objective To investigate the changes of expressions of cerebral cortex cell apoptosis-related factors including Bcl-2,Bax and Caspase-3 during starvation in rats. Methods Sixty adult male SD rats were randomly divided into 6groups： normal control group,3d,5d,7d,9d and 11 d starvation groups. The cerebral cortex cell apoptosis was detected by TUNEL method,the expression levels of Bcl-2,Bax and Caspase-3 mRNA were tested by RT-PCR,and,the expression levels of Bcl-2,Bax and Caspase-3 protein were measured by Western blotting. Results As compared with those in control group,the apoptosis cell numbers in cerebral cortex were obviously increased in 5d starvation group（ P 〈0. 05）,which were significantly increased in 7d,9d,11 d starvation groups（ P〈 0. 01）. The expression levels of Bax and Caspase-3 in cerebral cortex were significantly up-regulated in the four starvation groups（ P 〈0. 05）,furthermore,the up-regulation degree in 7d,9d,11 d starvation groups was more significant（ P〈 0. 01）. The expression levels of Bcl-2 were significantly up-regulated in3 d,5d and 7d starvation groups,as compared with those in control group（ P〈 0. 01）,with the highest expression levels in 5d group,however,which were decreased in 9d,11 d starvation groups,with the lowest expression levels in 11 d starvation group（ P〈 0. 01）. Conclusion The short-term starvation stress may have certain protective effect on brain,however,long-term starvation may inhibit the expressions of Bax,Caspase-3,Bcl-2 and may break the balance of Bcl-2 / Bax,as a result,which may induce cerebral cortex cell apoptosis.