miR-197结合HNRNPD的5'UTR区上调其蛋白表达

miR-197 Up-Regulates HNRNPD Expression by Complementary Pairing with Its 5'UTR

microRNA介导的基因调节在发育和疾病调控中都发挥了重要的作用.我们实验室前期研究发现miR-197可以调节神经干细胞分化.在本研究中,我们利用生物信息学数据库分析发现了9个miR-197的候选靶基因.qRT-PCR结果表明miR-197能下调其中8个基因的表达,但是显著上调了异质核糖核蛋白(Heterogeneous Nuclear RiboNucleoProtein,HNRNP)D0基因(HNRNPD)的表达.我们进一步实验发现,这种上调是通过miR-197与HNRNPD的5'UTR而不是3'UTR区的相互作用实现的.RNA pull-down实验证实miR-197的确与HNRNPD的5'UTR之间存在互补配对.并且敲低Ago2可以阻断miR-197介导的HNRNPD的上调,说明Ago2对于miR-197上调HNRNPD是必需的.已知HNRNPD能通过与AU-Rich Elements(AREs)结合来调控mRNA的降解.我们利用AutDB、SZDB和OMIM等多个数据库分析了几种神经发育障碍疾病(如自闭症和严重的智力障碍)的相关基因,发现这些基因含有比全基因组中更高比例的ARE-mRNA.因此,miR-197和HNRNPD在调节神经发育和相关疾病中可能具有重要作用.

microRNA-mediated gene regulation plays an important role in both development and disease regulation.We recently identified miR-197 plays important role during neural stem cell differentiation.In this study,we screened out 9 candidate target genes of miR-197 from five different types of cells.qRT-PCR results showed that miR-197 could down-regulate the expression of eight genes,but significantly increased the expression of HNRNPD.This up-regulation is mediated via the 5'UTR,not the 3'UTR of HNRNPD.RNA pull-down experiment confirmed that there was a complementary pairing between miR-197 and the 5'UTR of HNRNPD.Ago2 is required in this process as knocking down Ago2 can block miR-197 mediated up-regulation of HNRNPD.HNRNPD regulates mRNA decay through binding to AU-rich elements(AREs).We extracted several neurodevelopmental disorders related genes from multiple databases such as AutDB,SZDB,and OMIM.We analyzed the ARE-mRNA in these related genes and found that these genes contained a higher percentage of ARE-mRNA than that in the whole genome.Therefore,miR-197 and HNRNPD may play important roles in regulating neurodevelopment and related diseases.