全反式维甲酸在成年小鼠神经干细胞分化中的调控作用及机制

Regulation of all-trans-retinoic acid on differentiation of neural stem cells in adult mice

目的研究全反式维甲酸(ATRA)对成年小鼠神经干细胞(NSCs)的调控、信号通路及对细胞色素P450(CYP450)家族的影响。方法分离并培养成年小鼠脑室下区NSCs,将细胞分为ATRA组和对照组,ATRA组加入10-6mol/L ATRA,对照组正常培养。采用流式细胞仪检测两组细胞表面标记物,计算神经元、星形胶质细胞、少突胶质细胞和NSCs占总细胞数的百分比;Real-time PCR方法检测CYP450家族相关基因表达情况,筛选出有统计学意义的基因;ELISA法测定细胞色素P450还原酶(CPR)的活性;Western blotting法检测P38 MAPK通路相关蛋白P38、p-P38蛋白的相对表达量。结果 ATRA组NSCs主要是向神经元分化,也有一部分向星形胶质细胞分化,少突胶质细胞较少。与对照组比较,ATRA组P450家族基因中CYP26A1、CYP26B1、CYP26C1表达上调(P均<0.05)。ATRA组CPR活性以及p-P38蛋白表达量均较对照组升高(P均<0.05)。结论 ATRA促进小鼠NSCs向神经元分化,可能通过上调CYP450中的CYP26家族基因、增加CPR活性以及P38 MAPK通路发挥调控作用。

Objective To investigate the effects of all-trans-retinoic acid （ATRA） on signaling pathway and regulations of neural stem cells （NSCs） in adult mice and the effects on the family of c：ochrome P450 （CYP450）. Methods NSCs were isolated from the sub-ventricular zone （SVZ） of brain in adult mice and then were cultured. The cell.s were divided into the ATRA group and blank control group. The ATRA group was added with 10-6 mol/L ATRA. Flow cytometry （FCM） was used to detect the cell surface markers in the two groups, and we calculated the percentage of neurons, astro- cytes, oligodendrocytes and the percentage of NSCs accounting for total cells. The real-time PCR was used to detect the re- lated gene expression of CYP450 family, and we screened statistically significant gene. ELISA was applied to detect the activity of cytochrome P450 reductase （CPR）. The expression levels of P38 and p-P38 were detected by using Western blot- ring. Results In the ATRA group, NSCs mainly differentiated into neurons, and some differentiated into astrocytes, with less differentiation of oligodendrocytes. Compared with the blank control group, the expression. of CYP26A1, CYP26B1 and CYP26C1 in the P450 family genes of the ATRA group was up-regulated （all P 〈0.05）. The activity of CPR and the expression of p-P38 protein in the ATRA group were higher than those in the blank control group （ both P 〈 0.05）. Conclusion ATRA promotes the differentiation of mouse NSCs into neurons, and it may play a regulatory role by up-regulating the CYP26 family genes in CYP450 and increasing CPR activity and the P38 MAPK pathway.