脑源性神经营养因子对皮质酮诱导新生大鼠海马神经元凋亡的保护作用

目的 探讨脑源性神经营养因子(brain-derived neurotrophic factor, BDNF)对皮质酮诱导新生大鼠海马神经元凋亡的保护作用。 方法 原代培养新生大鼠海马神经元,并分成对照组、皮质酮组、皮质酮+BDNF组,皮质酮造模浓度为100 μM,分别采用浓度为0.1、1、10、25、50、100 ng/ml的BDNF干预,造模及干预时间均为24 h。CCK8法测定细胞活力,分析BDNF的最佳作用浓度,流式细胞术和 Hoechst荧光染色检测细胞的凋亡情况,免疫印迹(Western-blotting)法检测细胞Caspase-3、Caspase-9的表达水平。 结果 与对照组比较,皮质酮组神经元凋亡率由(10.7±1.2)%上升为(33.9±3.5)%(t=18.707,P<0.01),胞体透亮,部分细胞核碎裂,凋亡特征明显,Caspase-3、Caspase-9表达显著上调(t₁=27.098,P₁＜0.01;t₂=24.311,P₂＜0.01);BDNF作用后,细胞活力显著上升,在浓度为1 ng/ml时与皮质酮组比较差异有统计学意义(t=3.562,P＜0.05),分析得出BDNF最佳浓度为48 ng/ml;BDNF(48 ng/ml)干预完成后,细胞凋亡率较皮质酮组下降至(18.7±2.1)%,差异有统计学意义(t=11.478,P＜0.01),细胞形态基本恢复正常,Caspase-3、Caspase-9表达明显下调(t₁=17.341,P₁=0.002;t₂=14.993,P₂=0.005)。 结论 BDNF能有效拮抗皮质酮诱导的海马神经元凋亡,保护神经元细胞。

Protective effect of brain-derived neurotrophic factor on corticosterone-induced apoptosis in hippocampal neurons of neonatal rats

Objective To explore the protective effect of brain-derived neurotrophic factor (BDNF) on corticosterone-induced apoptosis in hippocampal neurons of neonatal rats. Methods Primary cultured hippocampal neurons of neonatal rats were divided into the control group, the corticosterone group and the corticosterone+BDNF group. The concentration of corticosterone was 100 μM, BDNF interventions were used with concentration of 0.1, 1, 10, 25, 50, and 100 ng/mL, and the modeling and intervention time were both 24 hours. Cell viability was determined by CCK8 method, the optimal concentration of BDNF was analyzed, the apoptosis of cells was detected by flow cytometry and Hoechst fluorescent staining, and the expression levels of Caspase-3 and Caspase-9 were detected by Western-blotting method. Results Compared with the control group, the apoptotic rate of neurons in the corticosterone group increased from (10.7±1.2)% to (33.9±3.5)% (t=18.707, P<0.01), the cell body was translucent,some of the nuclei were fragmented, the apoptosis characteristics were obvious, and the expression of Caspase-3 and Caspase-9 was significantly up-regulated (t₁=27.098, P₁＜0.001; t₂=24.311, P₂＜0.01). After BDNF treatment, the cell viability increased significantly, and the difference was statistically significant at the concentration of1 ng/mL between the control group and the corticosterone group (t=3.562, P<0.05). The optimal concentration of BDNF was 48 ng/ml. After BDNF (48 ng/ml) intervention, the apoptosis rate decreased to (18.7±2.1)% compared with the corticosterone group, showing a statistically significant difference (t=11.478, P<0.01). The cell morphology returned to normal, and the expression of Caspase-3 and Caspase-9 was down-regulated (t₁=17.341,P₁=0.002;t₂=14.993,P=0.005). Conclusions BDNF can effectively antagonize corticosterone-induced hippocampal neuronal apoptosis and protect neuronal cells.