糖氧剥夺诱导神经元磷酸化Rb蛋白表达特点及其与凋亡关系研究

The characteristic of expression of phospho-Rb and the relationship between it and neuronal apoptosis induced by oxygen-glucose deprivation in vitro

目的观察糖氧剥夺(OGD)诱导体外培养的皮层神经元细胞内磷酸化Rb蛋白(p-Rb)的表达特点并探讨其与神经元凋亡的关系。方法将体外培养的皮层神经元随机分为对照组、OGD1 h后恢复糖氧供给(OGD/R)6 h、12 h和24 h组。应用免疫荧光细胞化学染色观察神经元p-Rb表达特点及其与TUNEL染色的关系。结果 p-Rb在OGD/R各组神经元的表达率较对照组明显增高,主要在神经元细胞浆内强表达,OGD/R6h组p-Rb与TUNEL染色共定位细胞比例开始增高,12 h达最高,与对照组比较差异明显(P<0.01)。OGD/R24 h组很少观察到两者共定位染色。结论 Rb磷酸化介导的神经元细胞周期紊乱可能是缺血缺氧诱导的神经元早期凋亡机制之一。

Objective To investigate the characteristic of expression of phospho-Rb （p-Rb） and to explore the relationship between it and apoptosis in cortical neurons induced by oxygen-glucose deprivation （OGD） in vitro. Methods Cortical primary neuronal cultures were randomly divided into 4 groups： control group, the groups of 6 h, 12 h, 24 h reoxygenation after 1h of OGD. Immunofluorescence staining was used to detect expressions of p-Rb, percentages of neurons with p-Rb-positive and TUNEL-positive, and colocaliza- ted relationship between them. Results Compared with the control group, the strong expression of p-Rb, mainly in the cytoplasm of neurons, was significantly increased 6 h, 12 h and 24 h after OGD. p-Rb and TUNEL staining began to colocalize in neurons 6 h after OGD, and peaked at 12 h, which have significant differences between them and controls （P〈0. 01）. There was only a few neurons colocalized of p-Rh and TUNEL staining at 24 h after OGD. Conclusions Aberrant cell cycle regulation mediated by phosphorylation of Rb may be one of the apoptotic mechanisms in the early stages in neurons induced by OGD in vitro.