慢性应激对大鼠海马线粒体解偶联蛋白4及Bcl-2蛋白表达的影响

目的 探讨慢性应激对抑郁模型大鼠海马线粒体解偶联蛋白4（UCP4）及Bcl-2蛋白表达的影响.方法 应用慢性轻度不可预见性的应激制作抑郁症大鼠模型,随机分成2组：对照组、模型组.用流式细胞术分别检测海马组织细胞凋亡率、线粒体膜电位；用酶标仪检测乳酸脱氢酶（LDH）含量；用免疫组化检测神经细胞数目；用Western blot法检测UCP4及Bcl-2蛋白表达水平.结果 慢性应激干预后,模型组中海马神经细胞凋亡率[（4.35±0.19）％]和LDH含量[（445.5±91.70）U/mg）]明显升高,与正常对照组[（0.34±0.06）％,（167.2±63.40） U/mg）]相比,差异有统计学意义（P＜0.01）.与对照组相比[（72.50±4.25）个],模型组中海马组织神经细胞数目[（45.30±2.54）个]和线粒体膜电位有所下降.模型组中UCP4及Bcl-2蛋白水平表达下调.结论 抑郁症大鼠海马组织存在明显的神经元凋亡坏死,这可能与线粒体膜电位下降,UCP4及Bcl-2蛋白表达下调有关.

Effect of chronic stress on expression of uncoupling protein 4 and Bcl-2 protein of rat hippocampal mitochondria

Objective To investigate the effect of chronic stress on the expression of uncoupling protein 4 （UCP4） and Bcl-2 protein in hippocampal neurons of rat depression model.Methods Rat depression models were established by chronic unpredicted mild stress.All rats were randomly assigned to 2 groups：control group and model group.Flow cytometry was applied to detect the apoptosis rate and mitochondrial membrane potential.The level of LDH was measured by enzymes labelling instrument.The number of neurons was measured by immunohistochemistry.The expression of UCP4 and Bcl-2 protein was measured by Western blotting.Results After chronic stress,the apoptosis rate（（4.35±0.19） ％）and LDH activity （（445.50±91.70） U/mg） in hippocampal tissue in the model group was significantly higher than the control group（（0.34±0.06） ％,（167.20±63.40）U/mg）.Compared to control group,the number of hippocampal neurons （（72.50±4.25） vs （45.30±2.54）） and the mitochon drial membrane potential decreased in the model group.The expressions of UCP4 and Bcl-2 protein in hippocampal tissue were significantly lower than the control group.Conclusion Chronic unpredicted mild stress can lead to apoptosis in rat hippocampal neurons,which is related with decline of mitochondrial membrane potential and low expression of UCP4 and Bcl-2 protein.