糖尿病大鼠蛛网膜下腔出血后海马组织中caspase-3、Bax和Bcl-2的表达及醒脑静干预的研究

Expressions of caspase-3,Bax and Bcl-2 in hippocampal tissues and effect of Xingnaojing on them in diabetic rats with subarachnoid hemorrhage

目的探讨醒脑静对糖尿病大鼠蛛网膜下腔出血(SAH)后海马组织凋亡相关因子天冬氨酸特异性半胱氨酸蛋白酶(caspase-3)、Bax和Bcl-2表达的影响。方法成年雄性Wistar大鼠28只,按随机数字表法随机分为空白对照组(n=7)、糖尿病对照组(n=7)、糖尿病SAH组(n=7)和醒脑静治疗组(n=7);采用链脲佐菌素(STZ)腹腔注射方法建立糖尿病大鼠模型,然后采用枕大池两次注血法建立糖尿病大鼠SAH模型。SAH后48h取海马组织,用实时聚合酶链式反应检测caspase-3、Bax及Bcl-2的mRNA的表达,并用免疫印迹法测定它们蛋白表达,进行验证。结果空白对照组和糖尿病对照组大鼠海马组织中的caspase-3、Bax和Bcl-2的mRNA表达量均无显著差异(P>0.05);与空白对照组和糖尿病对照组相比,糖尿病SAH组和醒脑静治疗组其mRNA表达量均显著升高(P<0.05);醒脑静治疗组caspase-3和BaxmRNA表达水平均显著低于糖尿病SAH组大鼠(P<0.05),而Bcl-2mRNA表达水平却明显高于糖尿病SAH组(P<0.05)。它们蛋白表达变化与mRNA表达基本相符。结论醒脑静抑制糖尿病SAH大鼠海马组织促凋亡相关因子表达,而促进抗凋亡相关因子表达,从而发挥保护作用。

Objective To investigate the changes in cysteine-containing aspartate-specific proteases 3 （caspase-3）, Bax and Bcl-2 expressions in hippocampal tissues and the effect of Xingnaojing （XNJ） on them after subarachnoid hemorrhage （SAH） in the rats with diabetes. Methods Twenty-eight adult male Wistar rats with SAH were randomly divided into 4 groups of 7 animals each, i.e. normal group, diabetic group; diabetic and SAH group; XNJ treatment group. The diabetes models were established by intraperitontal injection of streptozotocin （STZ） in rats. SAH models were established by two injections of fresh autologous blood into the cisterna magna of diabetic rats. Expressions of caspase-3 mRNA, Bax mRNA, and Bcl-2 mRNA in the hippocampal tissues, which were derived from the rats scarificed 48 hours after the second intraperitoneal injection of the autologous blood, were detected by real-time PCR and were further verified by Western blot. Results The levels of caspase 3, Bax and Bcl-2 mRNA expressions in diabetic and SAH group and XNJ group were significantly higher than those in the normal and diabetic groups （P〈0.05）. The levels of caspase-3 and Bax mRNA expressions were significantly lower and the level of Bcl-2 mRNA expressions was significantly higher in XNJ group than those in the diabetic and SAH group （P〈0.05）. Western blot showed that the changes in caspase-3 Bax and Bcl-2 protein expressions levels were siuilar to those in their mRNA expressions levels in all the groups. Conclusions 1It is suggested that the cellular apoptosis may occur after SAH in the hippocampal tissues of the rats with diabetes. （2）XNJ has protective effect on hippocampal tissue by inhibiting the apoptosis and promoting antiapoptosis in the diabetic rats with SAH.