细胞周期抑制剂对糖氧剥夺诱导神经元凋亡的保护机制研究

目的:探讨细胞周期抑制剂Roscovitine (Ros)对糖氧剥夺(OGD)诱导的鼠大脑皮质神经元凋亡的保护作用及可能机制.方法:体外培养大鼠皮质神经元,随机分为对照组、OGD1 h后恢复糖氧供给(OGD/R)3 h、6h、12 h、24 h组及Ros(100 μM)组.Western Blot检测各组神经元磷酸化视网膜母细胞瘤蛋白( p-Rb)和E2F1的表达情况;免疫荧光细胞化学染色观察OGD/R12 h组及Ros组神经元p-Rb表达;TUNEL法检测OGD/R12 h组及Ros组神经元凋亡情况.结果:OGD/R各组神经元p-Rb及E2F1的表达均较对照组增高(P＜0.05),12 h达最高;Ros组p-Rb及E2F1的表达减少,少于OGD/R12 h组(P＜0.05);Ros组p-Rb和TUNEL阳性细胞率均低于OGD/R 12 h组(P＜0.01),两组中大部分TUNEL阳性细胞与p-Rb表达共定位.结论:Ros可能通过抑制Rb磷酸化及E2F1介导的凋亡机制来减少缺血缺氧后的神经元凋亡.

Protective Effects of Cell Cycle Inhibitor on Neuronal Apoptosis Induced by Oxygen-glucose Deprivation in vitro

Objective: To explore the protective effect and potential mechanism of roscovitine on rat cortical neuronal apoptosis induced by oxygen-glucose deprivation(OGD) in vitro.Methods: Primary rat cortical neuronal cultures were randomly divided into 6 groups:control group,the groups of 3 h,6 h,12 h,24 h reoxygenation after 1 h of OGD and roscovitine(100 μM) treated group.The expressions of phospho-Rb(p-Rb) and E2F1 were detected by western blot.Immunofluorescence staining was used to detect percentage of neurons with p-Rb-positive and TUNEL-positive,and the correlation between them was analyzed.Results: When compared with the control group,the expressions of p-Rb and E2F1 in each group after OGD were increased(P<0.05) and peaked at 12 h after OGD,which were decreased in the roscovitine treated group(P<0.05).Roscovitine significantly reduced the expression of p-Rb and decreased neuronal apoptosis at 12 h after OGD(P<0.01).A majority of apoptotic neurons of TUNEL staining had a co-localization with p-Rb staining.Conclusion: Roscovitine could reduce neuronal apoptosis,perhaps by way of inhibiting phosphorylation of Rb and transcription factor E2F1 after an ischemia/hypoxia injury in vitro.