LncRNA Rmrp通过miR-1a/Jund/AP-1信号途径调控DN系膜增生和外基质积聚

The proliferation of glomerular mesangial cells and extracellular matrix accumulation play important roles in the development of diabetic nephropathy (DN). The abnormal expression of lncRNAs have been found to participate in DN progression, but the study of lncRNAs is still in its infancy. The preliminary experimental evidence suggests the over-expression of lncRNA Rmrp promoted cell proliferation and extracellular matrix accumulation by interacting with miR-1a through Jund in mesangial cells under high glucose condition.. In this project, The effect of lncRNA Rmrp on the proliferation of mesangial cells and deposition of extracellular matrix will be examined by upregulating and knockdown the expression of lncRNA Rmrp. The molecular signaling pathways was explored with lncRNA Rmrp by bioinformatic investigation, luciferase reporter assay, FISH, RIP assay, Western blotting and so on. The influence of lncRNA Rmrp on the miR-1a/Jund/AP-1 pathway in vitro and in vivo will be investigated. The present study may help to elucidate the physiopathological mechanism of DN progression.

肾小球系膜增生和外基质聚积是糖尿病肾病(DN)进展的重要原因之一，lncRNAs异常与DN聚密切相关，但其作用机制尚不清楚。我们前期工作提示在高糖刺激的肾小球系膜细胞中，高表达的lncRNA Rmrp可能是以竞争性内源RNA结合miR-1a，干扰miR-1a对Jund的表达抑制，活化AP-1，引起系膜细胞增殖和外基质积聚。. 本项目通过敲除和过表达肾小球系膜细胞中lncRNA Rmrp，研究lncRNA Rmrp对系膜细胞增殖和细胞外基质积聚等生物学特性的影响；通过生物信息学、双荧光素酶报告基因技术、荧光原位杂交、RIP、蛋白免疫印记等技术检测lncRNA Rmrp对DN作用的分子信号途径，体内和体外验证lncRNA Rmrp通过miR-1a/Jund/AP-1信号途径调节DN的作用机制。本研究有助于说明DN发生发展的机制。

肾小球系膜增生和外基质聚积是糖尿病肾病(DN)进展的重要原因之一，长链非编码RNA（long noncoding RNAs，lncRNAs）异常与DN发生发展密切相关，但其作用机制尚不清楚。因此，本课题拟探讨lncRNA对DN系膜肾小球增生和外基质积聚中的作用及机制。我们观察到lncRNA Rmrp在DN小鼠和高糖培养的系膜细胞中表达上调。更重要的是，异常转录lncRNA Rmrp受到了转录因子Sp1的调控，促进系膜细胞的增殖和外基质蛋白积累。随后，我们筛选了lncRNA Rmrp相关的miRNAs，发现lncRNA Rmrp 和miR-1a-3p在系膜细胞的细胞质中共定位。双荧光素酶结果证明lncRNA Rmrp与miR-1a-3p直接结合。进一步的机制研究表明，提高miR-1a-3p的表达显著减弱了lncRNA Rmrp诱导的系膜细胞增生和外基质蛋白的积聚现象。同时，我们还证明了miR-1a-3p可直接与jun D原癌基因（jun D proto-oncogene，JunD）结合，从而调控JunD的蛋白水平。LncRNA Rmrp诱导的系膜细胞增生和外基质蛋白积聚可以被JunD siRNA逆转。综上所述，在DN发生发展中，Sp1诱导的lncRNA Rmrp可以以“海绵”的模式吸附miR-1a-3p，从而促进JunD的表达，引起系膜细胞增生和外基质蛋白的积聚。