NDRG2在脑缺血再灌注大鼠室管膜下区的表达研究

目的:探讨ndrg2基因在大鼠脑缺血再灌注后于侧脑室室管膜下区的表达,并探索其规律。方法:成年雄性Sprague-Dawley大鼠,利用大脑中动脉栓塞法造成短暂性脑缺血(MCAO),缺血后2 h再灌注,制备损伤模型。分为假手术组(n=6)、缺血后4 h(n=8)、12 h(n=8)和24 h(n=8)四组。假手术组除不用线栓阻塞大脑中动脉外,其余与缺血组相同。采用原位杂交和Western blot方法观察,MCAO后不同时间点NDRG2在大鼠脑内的表达特点。结果:原位杂交结果显示:NDRG2 mRNA集中表达于侧脑室室管膜下区,阳性细胞呈蓝紫色表达于细胞质,细胞核未见表达。脑缺血再灌注后NDRG2阳性细胞数随时间延长而增多,各缺血组(4 h、12 h和24 h)与假手术组相比均具有统计学差异(P<0.05),其中缺血24 h组的阳性细胞数最多;Western blot结果与原位杂交结果一致:各缺血组NDRG2蛋白表达水平随着缺血再灌注时间而增加,与假手术组相比具有统计学差异(P<0.05)。结论:NDRG2集中表达于大鼠侧脑室室管膜下区;脑缺血再灌注可以诱导该区内NDRG2表达的明显增高。

Experimental study on the changes of N-myc downstream regulated gene 2 expression in rat models of middle cerebral artery occlusion

Objective: To investigate the expression and regular pattern of N-myc downstream regulated gene 2(NDRG2) in subventricular zone in rat models of middle cerebral artery occlusion(MCAO).Methods: Adult male Sprague-Dawley rats were subjected to MCAO,causing a cerebral ischemic model,and then divided into four groups: the sham group(n=6),4 h(n=8),12 h(n=8) and 24 h(n=8) post-ischemia groups.The sham rats were subjected to surgery but not received occlusion.In situ hybridization and Western blot was used to analyze the changes in the expression of NDRG2 in rat brain after MCAO.Results: In situ hybridization results showed that NDRG2 mRNA was mainly expressed in the cells of subventricular zone,prominent hybridization signals of NDRG2 were distributed in cytoplasm but not in the nucleus.The expression level of NDRG2 mRNA was low in the sham group.Following MCAO,NDRG2-positive cells in subventricular zone at different time points(4 h,12 h and 24 h) were markedly increased(P<0.05),compared with the sham group.Western blot showed the similar results to that of in situ hybridization: NDRG2 protein was observed both in the sham group and ischemic groups;MCAO induced a significant increase of NDRG2 expression,compared with the sham group(P<0.05).Conclusion: NDRG2 is mainly expressed in subventricular zone of rat brain.Cerebral ischemia induces a significant up-regulation of NDRG2 in this region.