丙泊酚后处理对氧糖剥夺-复糖复氧大鼠海马神经元Rb-E2F1信号通路的影响

Effect of propofol postconditoning on Rb-E2F1 signaling pathway in hippocampal neurons in a rat model of oxygen-glucose deprivation and restoration

目的:评价丙泊酚后处理对氧糖剥夺-复糖复氧海马神经元视网膜母细胞瘤蛋白(Rb)-转录因子E2F1(E2F1)信号通路的影响。方法:原代培养孕16~18 d的Wistar大鼠胎鼠海马神经元7 d,采用随机数字表法分为3组(n=42):对照组(C组)正常培养;氧糖剥夺-复糖复氧组(O组)氧糖剥夺1 h后复氧复糖;丙泊酚后处理组(P组)复糖复氧即刻加入丙泊酚(终浓度1.2μg/ml)孵育2 h,更换为正常培养液。于继续培养24 h时收集细胞,采用Western blot法检测p-Rb和E2F1的表达,采用流式细胞术检测神经元细胞周期和凋亡率。结果:与C组比较,O组和P组神经元凋亡率升高,p-Rb和E2F1表达上调,p-Rb核浆比例和G 0/G 1期细胞比例降低,S期和G_(2)/M期细胞比例增加(P<0.05);与O组比较,P组神经元凋亡率降低,p-Rb和E2F1表达下调,p-Rb核浆比例和G 0/G 1期细胞比例升高,S期和G_(2)/M期细胞比例降低(P<0.05)。结论:丙泊酚后处理降低氧糖剥夺-复糖复氧海马神经元凋亡的机制与其抑制Rb-E2F1信号通路有关。

Objective To evaluate the effect of propofol postconditoning on retinoblastoma protein(Rb)-E2F1 signaling pathway in hippocampal neurons in a rat model of oxygen-glucose deprivation and restoration(OGD/R).Methods Pregnant Wistar rats at 16-18 days of gestation were sacrificed,and the hippocampal neurons of fetal rats were obtained and primarily cultured for 7 days.The neurons were divided into 3 groups(n=42 each)using a random number table method:control group(group C),OGD/R group(group O)and propofol postconditoning group(group P).In group O,the neurons were subjected to oxygen-glucose deprivation for 1 h,followed by restoration of oxygen-glucose.In group P,propofol(final concentration 1.2μg/ml)was added immediately after restoration of oxygen and glucose,and the cells were cultured for 2 h and then the culture medium was replaced with plain culture medium.At 24 h of culture,the expression of p-Rb and E2F1 was determined by Western blot,and the cell cycle and apoposis rate were assessed by flow cytometry.Results Compared with group C,the apoptosis rate was significantly increased,expression of p-Rb and E2F1 was up-regulated,the ratio of p-Rb nuclear/plasmosin protein and the proportion of neurons in G0/G1 phase were decreased,and the proportion of neurons in S and G_(2)/M phases was increased in O and P groups(P<0.05).Compared with group O,the apoptosis rate was significantly decreased,expression of p-Rb and E2F1 was down-regulated,the ratio of p-Rb nuclear/plasmosin protein and the proportion of neurons in G0/G1 phase were increased,and the proportion of neurons in S and G_(2)/M phases was decreased in group P(P<0.05).Conclusion The mechanism by which propofol postconditioning decreases the apoptosis in hippocampal neurons is related to inhibiting Rb-E2F1 signaling pathway in a rat model of OGD/R.