神经生长因子对新生大鼠HIBD后海马区凋亡相关蛋白表达的影响

Effects of nerve growth factor on expressions of apoptosis-related proteins in hippocampus of neonatal rats following hypoxic-ischemic brain damage

目的:应用新生大鼠缺氧缺血性脑损伤(HIBD)模型,观察神经生长因子对海马区细胞凋亡及相关蛋白Bcl-2和Bax的影响,探讨其神经保护作用的分子生物学机制.方法:72只大鼠随机分为对照组、HIBD组和NGF治疗组.应用改良RICE法制作大鼠HIBD模型,TUNEL法检测各组动物海马区细胞凋亡数,免疫组化染色观察Bcl-2,Bax蛋白的表达.结果:与假手术组相比,新生大鼠HIBD后海马区存在不同程度的细胞凋亡,Bcl-2表达轻度升高,Bax表达明显升高.与HIBD组比较,NGF治疗后,凋亡细胞减少(P<0.01),Bcl-2蛋白表达升高(P<0.01),Bax表达下降(P<0.01).结论:HIBD后,新生大鼠海马区细胞存在细胞凋亡,NGF治疗增强Bcl-2表达,减少损伤基因Bax表达,抑制细胞凋亡,具有脑保护作用.

AIM： To investigate the effects of nerve growth factor （NGF） on the expression of apoptosis-related proteins （Bcl-2, Bax）in hippocampus of neonatal rats following hypoxicischemic brain damage （HIBD）, and its molecular biological mechanism. METHODS： Seventy-two rats were randomly divid- ed into control group, HIBD group and NGF group. The rat mod- els of HIBD were established by modified RICE method. Immuno- histochemistry and TUNEL staining were employed respectively to detect the expressions of Bcl-2 and Bax and the number of apoptotic hippocampal neurons. RESUILTS： More or less apoptotic neurons could be observed in hippocampus in HIBD group and the level of Bcl-2 expression was elevated slightly, while Bax expression was significantly higher than that in control group. After NGF administration, the number of apoptotic neurons was decreased （P〈0.01）, Bcl-2 expression increased （P 〈0.01） and Bax expression decreased remarkably （ P 〈 0.01 ） as compared with HIBD group. CONCLUSION： The administration of NGF may increase Bcl-2 expression and decrease Bax expression after HIBD in neonatal rats, thus inhibiting the apoptosis in hippocampus.