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目的:研究缺血再灌注损伤对成年大鼠脑室下区(SVZ)神经干细胞增殖和NMDA受体亚单位NR2A表达的影响,探讨NR2A在神经干细胞增殖中的作用。方法:正常成年雄性SD大鼠45只,随机分成正常组、假手术组和缺血再灌注组,线栓法制作大脑中动脉栓塞(middle cerebral artery occlusion,MCAO)2 h再灌注模型,术后分3、7、14 d三个时间点取脑。行免疫组织化学染色观察Nestin、增殖细胞核抗原(PCNA)及NMDA受体亚单位NR2A阳性细胞数。结果:(1)各组大鼠SVZ均可见Nestin和PCNA阳性细胞,缺血再灌注后3 d,脑室下区Nestin IOD值和PCNA阳性细胞增加(P<0.05),7 d达到高峰(P<0.05),14 d后有所下降(P<0.05)。(2)各组大鼠SVZ均表达NR2A阳性细胞,缺血再灌注后3 d,NR2A阳性细胞数开始增加(P<0.05),7 d也达到高峰(P<0.05),14 d阳性细胞数有所下降,但维持较高的水平(P<0.05)。(3)缺血再灌注后不同时间点NR2A阳性细胞数与PCNA阳性细胞数有高度正相关性(r=0.985,P<0.05)。结论:缺血再灌注损伤能刺激成年大鼠SVZ神经干细胞的增殖;缺血再灌注后NMDA受体亚单位NR2A表达增加,并且与神经干细胞的表达变化趋于一致,因此推断NR2A可能参与缺血再灌注大鼠SVZ神经干细胞的增殖过程。
Objective: To investigate the effects of ischemia-reperfusion injury on the proliferation of neural stem cells and the expression of NMDA receptor subunit NR2A in the subventricular zone (SVZ) of adult rats and to explore the role of NR2A in the proliferation of neural stem cells. Methods: Forty-five normal adult male Sprague-Dawley rats were randomly divided into normal group, sham operation group and ischemia-reperfusion group. The MCAO model was made by reperfusion for 2 h. Points 3,7,14 d three time points to take the brain. The expression of Nestin, proliferating cell nuclear antigen (PCNA) and NMDA receptor subunit NR2A positive cells were observed by immunohistochemical staining. Results: (1) Nestin and PCNA positive cells were observed in all the SVZ rats. Nestin and PCNA positive cells in the subventricular zone were significantly increased 3 d after ischemia / reperfusion (P <0.05), and peaked at 7 d (P < 0.05) and decreased after 14 days (P <0.05). (2) NR2A positive cells were expressed in SVZ of rats in each group, and the number of NR2A positive cells began to increase (P <0.05) on the 3rd day after ischemia-reperfusion and peaked on the 7th day (P <0.05) Decreased, but maintained a higher level (P <0.05). (3) There was a highly positive correlation between the number of NR2A positive cells and the number of PCNA positive cells at different time points after ischemia / reperfusion (r = 0.985, P <0.05). CONCLUSION: Ischemia / reperfusion injury can stimulate the proliferation of SVZ neural stem cells in adult rats. After reperfusion, the expression of NMDA receptor subunit NR2A is increased and the expression of NR2A is consistent with that of neural stem cells. Therefore, it is concluded that NR2A may be involved in ischemia Proliferation of SVZ neural stem cells in rats after reperfusion.