胰岛素对氧糖剥夺诱导大鼠脑神经元损伤的改善作用

Insulin prevents OGD/R-induced injury in cortical neuron of rats

目的:探讨胰岛素对氧糖剥夺诱导新生大鼠脑皮质神经元损伤的改善作用。方法:将培养7d的大鼠皮质神经元随机分为3组,A组为正常对照组,B组采用氧糖剥夺/复糖复氧(OGD/R)处理,C组采用胰岛素预处理加OGD/R处理,B、C组在OGD/R后0、1、6、12、24h各时间点,以MTT法检测细胞活性,采用脱氧尿嘧啶缺口末端标记法检测神经元凋亡情况,采用免疫细胞化学方法检测生长相关蛋白(GAP-43)、脑源性神经营养因子(BDNF)的表达。结果:①B组的神经元细胞活性较A组明显下降,C组细胞活性明显高于B组,3组比较差异有统计学意义(P<0.05)。②B组凋亡神经元细胞明显多于正常对照组,OGD/R后6、12、24h,C组凋亡细胞数目明显少于B组,3组比较差异有统计学意义(P<0.05)。③B组GAP-43、BDNF的表达较正常对照组明显增加,OGD/R后6、12、24h,C组GAP-43、BDNF表达较B组明显增加。结论:胰岛素预处理可明显提高OGD/R后神经元的存活率,抑制神经元凋亡,使GAP-43、BDNF表达增加,实现神经元损伤的改善作用。

Aim： To explore the protective effects of insulin on injury induced by OGD/R in neonatal rats. Methods： Cortical neurons cultured for 7 days were randomly divided into A （normal control group）, B （OGD/R alone）, C （pretreatment with insulin） 3 groups. Then detect cell survival rate by MTT colorimetry, count the apoptosis neurons by TUNEL （TdT mediated dUTP nick end labeling） , observe the expression of GAP-43, BDNF using lmmunocytochemical on each time point after OGD/R 0 h,l h, 6 h, 12 h, 24 h of each group. Results： （1）Compared with group A, the cell survival rate in group B decreased, the survival rate was increased in Group C due to pretreatment of insulin. （2）The apoptosis neurons in group B were more than those in control group after OGD/R 6 h,12 h,24 h,the group C less than group B. （3）The expression of GAP-43, BDNF was increased in group B after OGD/R 6 h,12 h,24 h,and it was higher in group C than group B. Conclusion ： The study indicated that insulin could improve the survival rate of neurons after OGD/R, increase expressions of GAP-43, BDNF, inhabit neurocyte apoptosis,and these mechanisms play neuroprotective effects.