GAPDH在EPO减轻脑缺血再灌注大鼠神经损伤机制中作用的研究

Involving of GAPDH in mechanism of EPO reducing neural damage induced by ischemia/reperfusion

目的探讨GAPDH从胞浆移位入核内在EPO减轻脑缺血大鼠神经损伤机制中的作用。方法 36只SD大鼠随机分为假手术组、生理盐水对照组和EPO处理组。制作大脑中动脉栓塞脑缺血再灌注大鼠模型,用TTC染色法观察EPO对脑组织损伤情况的影响;用Hoechest-33258和GAPDH免疫组化双染观察EPO对GAPDH核内过表达的影响;用Hoechest-33258免疫荧光观察EPO对缺血半影区神经元凋亡的影响。结果大鼠脑缺血2 h再灌注24 h及48 h,与生理盐水对照组相比,缺血同时开始给予rhEPO(3000 U/kg,3次/d,腹腔注射)显著减轻缺血脑组织损伤范围、抑制缺血再灌注引起的GAPDH从神经元胞浆移位入核内引起的神经元凋亡。结论 GAPDH移位入核内,在rhEPO减轻脑缺血再灌注引起的神经损伤的机制中起重要作用。

Objective To study the involving role of over-expression of GAPDH in nucleus in rhEPO＇s reducing neuronal damage induced by ischemia/reperfusion in rats. Methods 36 adult SD rats were divided randomly into 3 groups： sham, saline and EPO treatment groups. Animal models of ischemia/reperfusion were established with middle cerebral artery occlusion in rats. We observed effects of EPO on the sizes of injury brain tissue induced by ischemia/reperfusion through TTC staining, on the over expression of GAPDH in nucleus using double staining of both Hoechest-33258 and GAPDH immunofluoresence, and even on the neuronal apoptosis in penumbra through Hoechest-33258 staining. Results 24 h or 48 h Reperfusion after 2 h of ischemia, injection of rhEPO （3000 U/kg, three times per day, i.p.） as soon as isehemia was established reduced the sizes of damaged brain apparently, rbEPO reduced numbers of apoptotic neurons in penumbra, while it inhibited translocations of GAPDH from cytoplasm into nucleus in apoptotic neurons in penumbra of ischemia/reperfusion rats. Conclusions Translocation of GAPDH from cytoplasm into nucleus of apoptotic neurons is evidently involved in the mechanism of rhEPO inhibiting neuronal damage induced by ischemia/reperfusion.