铝作用下大鼠海马神经细胞凋亡与bcl-2和bax基因转录的关系

Relationship between apoptosis of rat hippocampus cells induced by aluminum and the copy of the bcl-2 as well as bax mRNA

目的探讨铝引起大鼠海马神经细胞凋亡与bcl2、baxmRNA表达变化的关系。方法健康雄性SD大鼠40只,按体重随机分为4组:生理盐水组、Al3+2.5、5.0、10.0mgkg组。染毒60天后处死,用TUNEL法检测细胞凋亡,RTPCR法检测bcl2、baxmRNA的表达,用凝胶成像系统进行结果分析。结果与对照组相比,Al3+5.0mgkg、10.0mgkg组大鼠海马神经细胞凋亡率显著升高(P<005),而Al3+2.5mgkg组与对照组相比凋亡率升高,但差异无显著性;3个染毒组bcl2mRNA表达均显著下降(P<0.05);3个染毒组baxmRNA表达显著升高(P<0.05);海马神经细胞凋亡指数与bcl2mRNA表达呈负相关(r=-0.909,P<0.01),与baxmRNA表达呈正相关(r=0.871,P<0.01)。结论铝可以诱导大鼠海马神经细胞凋亡,其机制与bcl2mRNA表达下调,baxmRNA表达上调有关。

Objective To explore the effects of aluminum chloride （AlCl3） on the apoptosis of rat hippocampus cells and the relationship between the apoptosis and the expression of the bcl-2 as well as bax mRNA. Methods 40 SD rats, adult and healthy, were divided into 4 groups randomly： normal saline, Al^3＋ 2.5mg/kg, 5mg/kg, 10mg/kg. They were exposed to AlCl3 by intraperitioneal injection at the dose of 0.2ml/d for 60days. After exposure, the apoptosis of hippocampus cells were measured by method of TUNEL. The expression of bcl-2 mRNA and bax mRNA in rats＇ hippocampus were measured by RT-PCR. The results were analyzed by the gelatum analyzing system. Results The rates of apoptosis in hippocampus cells in Al^3＋ 5mg/kg group and Al^3＋ 10mg/kg group were significantly higher than that of controls （P 〈 0.05）. But Al^3＋ 2.5mg/kg group was not significantly higher than that of control （P 〉 0.05）, and was significantly decreased in hippocampus cells in Al^3＋ 5mg/kg and 10mg/kg group compared with the control group （ P 〈 0.05）. The expression of bcl-2 mRNA was significantly decreased in every aluminum treatment group compared with the control group （P 〈 0.05） . The expression of bax mRNA was significantly increased in every aluminum treatment group compared with the control group （ P 〈 0.05） . There was negative correlation between AI and the expression of Bcl-2 （ r = -0.909, P 〈0.01 ）. There was positive correlation between AI and the expression of Bax （r = 0.871, P 〈 0.01 ）. Conclusion Aluminum can induce apoptosis in rat hippocampus cells through the downwards regulation of bcl-2 mRNA, the upwards regulation of bax mRNA expression.