RBMX调控外泌体分选miRNAs在糖尿病肾脏病肾小管线粒体能量代谢中的作用及机制研究

申请者在前期工作中发现糖尿病肾脏病（DKD）患者尿液外泌体中与脂肪酸代谢通路相关且具有肾脏保护作用的miRNAs显著增加，抑制受损肾小管细胞外泌体分泌可以改善线粒体能量代谢，进一步敲除RBMX可促进上述“保护性miRNAs”在细胞内堆积，从而改善线粒体能量代谢。因此，我们推测RBMX可能通过直接结合“保护性miRNAs”促进其通过外泌体释放出细胞，从而调控线粒体能量代谢，促进DKD进展。本课题拟在基因芯片基础上，构建肾小管上皮细胞条件性Rbmx敲除的糖尿病小鼠和稳定过表达或敲除RBMX的肾小管上皮细胞验证RBMX促进外泌体分选“保护性miRNAs”调控线粒体能量代谢的作用；采用RIP、RNA pull down和突变等技术探讨RBMX特异性识别miRNAs的分子机制。本课题将阐明RBMX促进外泌体分选被特异性识别的miRNAs，导致肾小管线粒体能量代谢障碍的机制，为DKD的防治提供新思路。

In our previously research, we found that miRNAs related to fatty acids metabolic pathways and with renal protective effects were significantly increased in urinary exosomes in patients with diabetic kidney disease. Besides, we found that inhibiting exosome secretion of albumin induced renal tubular epithelial cells can improve mitochondrial energy metabolism. Meanwhile, we also found that knockout of RNA-binding protein RBMX can promote the accumulation of the above protective miRNAs in cells, thereby improving mitochondrial energy metabolism. Therefore, we speculated that RBMX may directly bind to "protective miRNAs" to promote its release of cells through exosomes, leading to energy metabolism disorders in renal tubular mitochondria, and promote the development of DKD. On the basis of genomic microarray, we plan to construct the DKD mice with conditional deletion of Rbmx in renal tubular epithelial cells and the renal tubular epithelial cells with stable overexpression or knockout of RBMX to verify RBMX promote exosomal sorting of miRNAs regulate mitochondrial energy metabolism; The RIP, RNA pull down, miRNA mutation and other techniques will be employed to explore the mechanism of miRNAs specifically identified by RBMX are released to the extracellular via exosomal sorting, leading to mitochondrial energy metabolism disorders. This research will clarify the mechanism of RBMX promoting exosomal sorting of miRNAs, which were specifically identified by RBMX, leading to renal tubular mitochondrial energy metabolism disorders, providing a new idea for the prevention and treatment of DKD.