大鼠早期放射性脑损伤后少突胶质细胞内Tau蛋白表达的变化特征

目的 观察大鼠全脑照射条件下皮质下白质区少突胶质细胞内Tau蛋白在不同剂量和不同时间点的表达情况。方法 分别以单次2、10和30 Gy照射大鼠全脑后24 h、1周和1个月时用免疫组织化学法观察少突胶质细胞内Tau-1和Tau-5的表达,并分析剂量、照射后时间的影响。结果 照射后24 h Tau-1的表达迅速升高达到峰值,1周后开始下降,其表达与照射剂量呈正相关,1个月后恢复照射前水平。Tau-5的表达各组在不同时间点表达差异无统计学意义(P>0.05)。结论 在大脑受电离辐射后早期,少突胶质细胞内Tau蛋白出现迅速的一过性去磷酸化,并且呈剂量依赖性。这提示Tau蛋白在早期放射性脑损伤的发生、发展过程中可能起到了一定的作用。

Alteration of Tau protein in rat oligodendrocytes after early radiation-induced brain injuries

Objective To observe the expression of Tau protein in oligodendrocytes within subcortical white matter at different doses and time-points after whole-brain irradiation.Methods A model of brain radiation-induced injury was established in rat after whole-brain irradiation with single dose of 4 MeV electron beam. The expression of Tau-1 and Tau-5 in oligodendrocytes within subcortical white matter was analyzed by immunohistochemistry at different time-points (24 hours, 1 week and 1 month) and different doses (2, 10 and 30 Gy).Results The expression of Tau-1 in oligodendrocytes reached the peak level in 24 hours, which was 1.5-2 times as high as the normal group. It began to decrease after 1 week and returned to the normal level in 1 month. The expression levels of Tau-5 showed no difference at different time points (P>0.05).Conclusions Tau protein in oligodendrocytes undergo rapid and temporal dephosphorylation after early radiation-induced brain injury in a dose-dependent manner. It is suggested that Tau protein might play an important role in the early stage of brain radiation injury.