大鼠局灶性脑缺血预处理后生长停滞与DNA损害可诱导基因34表达的变化

Expression changes of both mRNA and protein levels of growth arrest and DNA damage-inducible gene 34 in rat after focal cerebral ischemic preconditioning

目的观察脑缺血预处理(brain ischemia preconditioning,BIP)对大鼠脑缺血再灌注后,生长停滞与DNA损害可诱导基因34(GADD34)mRNA及蛋白表达的影响。方法健康雄性SD大鼠120只,随机分为假手术组、脑缺血组、BIP组,每组40只,后2组行大脑中动脉栓塞法制模后,各组于再缺血后12 h、1、2和3 d 4个时间点观察,每个时间点10只。采用2次线栓法制备大鼠局灶性脑缺血预处理模型,用原位杂交法检测GADD34 mRNA表达,western blot法观察各组GADD34蛋白表达。结果与假手术组比较,脑缺血组12 h GADD34 mRNA及蛋白表达均达高峰,随再灌注时间延长,其表达逐渐下降,但1、2和3 d时仍高于假手术组(P<0.05,P<0.01);BIP组GADD34 mRNA及蛋白表达各时间点均较脑缺血组明显升高(P<0.05,P<0.01)。结论 BIP可诱导GADD34mRNA及蛋白的表达。

Objective To investigate the effect of focal cerebral ischemic preconditioning on the expression level of mRNA and protein of growth arrest and DNA damage-inducible gene 34（GADD34） after focal cerebral ischemia/reperfusion（I/R） in rats. Methods 120 male SD rats were randomly divided into three groups： sham-operation group,middle cerebral artery occlusion（brain ischemia） group and brain ischemia preconditioning（BIP） group. Each group was further divided into 4 sub- groups according to 12 h,1 d,2 d and 3 d after I/R. The BIP models were made in order to measure the expression of GADD34 mRNA and protein by in situ hybridization and Western blot. Results Compared with sham-operation group,in brain ischemia group,the expression of both GADD34 mRNA and its protein were increased and reached the peak at 12 h, then decreased continuously （P〈0.05 ,P〈0.01）. Ischemic preconditioning could increase their expression（P〈0.05, P〈0.01）. Conclusion Ischemic preconditioning could induce the expression of GADD34 after I/R in rats.