miR-124对Müller细胞转分化机制的影响

目的 探讨过表达miR-124对Müller细胞转分化机制的影响。方法 构建pSuper-EGFP-miR-124质粒并测序验证,获得miR-124的过表达载体。并用其转染Müller细胞系,用G418进行筛选,获得Müller细胞稳转株,将样本送基因芯片检测。利用TargetScan和miRBase Targets数据库预测差异表达明显的miR-124靶基因,通过Real-Time PCR和荧光素酶活性测定实验验证分析miR-124的靶基因,筛选变化比较显著的基因进一步研究。miR-124转染Müller细胞,提取mRNA和蛋白,采用Real-Time PCR、Western印迹法检测相关基因的变化。结果 成功构建pSuper-EGFP-miR-124质粒并获得了稳定转染的Müller细胞系。荧光素酶报告分析表明,miR-124与STAT3(signal transducers and activators of transduction-3, STAT3) 3′UTR相互作用。体外结果显示,pSuper-miR124转染Müller细胞后,STAT3表达下降并开始表达光感受器细胞标志物CRX(Cone-Rod Homeobox, CRX)和RCVRN(Recoverin, RCVRN)。结论 miR-124可能通过下调STAT3,上调CRX和RECVN,诱导Müller细胞向感光细胞转分化。
Objective To investigate the mechanism of miR-124-induced transdifferentiation in Müller cells. Methods The pSuper-EGFP-miR-124 plasmid was constructed and sequenced, then transfected in Müller cells and verified by microarray analysis. miR-124 target genes were predicted with the combination of DNA microarray analysis, TargetScan and miRBase Targets databases. Real-time PCR and luciferase were employed to verify those target genes, and the differentially expressed genes were picked up for future study. The changes of related genes were detected by Real-time PCR and western blot in pSuper-miR-124 transfected Müller cells. Results pSuper-EGFP-miR-124 plasmid was cloned and sequenced, its sequence was confirmed. The stable transfected Müller cells were obtained under the selection of G418. Based on the results of microarray analysis, differentially expressed genes of interest were verified, especially STAT3 which showed significant trend. It showed that miR-124 regulated expression of STAT3 by directly targeting its 3′-UTR, and inhibition of STAT3 activation increased the expression of photoreceptor cell markers CRX and RCVRN in cultured Müller cells. Conclusion The miR-124 targets STAT3 to up-regulate CRX and RCVRN expression in Müller cells, which suggests that miR-124 may induce transdifferentiation of Müller cells to photoreceptor. It can be speculated that miR-124 could protect against retinal degeneration via inhibition of Müller cell gliosis and induction of Müller cell transdifferentiation