NF-κB/LncRNA CRNDE/p62信号转导在糖尿病肾病炎症与蛋白尿反馈调节中的作用

Diabetic nephropathy (DN) is a common and refractory microvascular complication of diabetes mellitus. The feedback regulation of inflammation and proteinuria is the key reason for diabetic nephropathy progression, however, the mechanism is still unclear. In the previous study, we applicated the lncRNAs microarray technology to detect and screen the specific lncRNAs of glomerular podocyte injury, and validated using quantitative real-time polymerase chain reaction. We found that lncRNA CRNDE was significantly upregulated under high glucose and TNF- stimulation, also in kidney tissue of diabetic nephropathy patients. Moreover, RNA pull-down assay and mass spectrometry identified that lncRNA CRNDE binded with p62, a protein that mediates mitophagy. Furthermore, Bioinformatics prediction and ChIP-PCR confirmed that NF-κB binded to the promoter of lncRNA CRNDE. Therefore, we hypothesize that in diabetic nephropathy, NF-κB directly binds to the promoter of lncRNA CRNDE and transcriptionally up-regulates its expression, subsequently, lncRNA CRNDE binds to p62 and induces excessive p62-dependent mitophagy, causing podocyte apoptosis and damage, resulting in proteinuria finally. This project intends to further confirm that the role of NF-κB/lncRNA CRNDE/p62 signal transduction in promoting the feedback regulation of inflammation and proteinuria in diabetic nephropathy, which could provide new ideas for clinical prevention and treatment of diabetic nephropathy.

糖尿病肾病（DN）是糖尿病常见且难治的微血管并发症，炎症与蛋白尿反馈调节是DN进展关键原因，然而其机制尚不清楚。我们前期应用LncRNAs芯片筛选到肾小球足细胞损伤关联的LncRNA CRNDE ；上调表达LncRNA CRNDE能促进足细胞凋亡；应用RNA pull-down及质谱鉴定出LncRNA CRNDE与介导线粒体自噬的蛋白质p62相结合；生物信息学预测及ChIP-PCR证实NF-κB直接结合LncRNA CRNDE的启动子。因此，我们提出DN时NF-κB结合到LncRNA CRNDE的启动子，转录上调其表达。LncRNA CRNDE与p62结合，过度介导p62依赖的线粒体自噬，引起足细胞凋亡损伤，导致蛋白尿产生。本项目拟进一步证实NF-κB/LncRNA CRNDE/p62信号转导促进DN炎症与蛋白尿的反馈调节，并探讨这一事件对DN进展重要性和意义，为临床防治DN提供新的思路。

糖尿病肾病（diabetic nephropathy, DN）是糖尿病最严重的微血管并发症之一。足细胞是一种定位于肾小球的高度分化细胞，与肾小球血管内皮细胞和基底膜共同构成与肾小球滤过屏障，既往研究表明足细胞损伤是DN早期出现蛋白尿并导致肾功能恶化进展的主要原因之一。越来越多证据表明lncRNAs的异常表达与DN的发生、发展密切相关，然而其参与DN的发生机制尚不十分明确。.本研究发现：.1.在DN患者和DN小鼠模型中lncRNA CRNDE的表达水平明显升高，并定位于肾小球足细胞胞核，体外研究发现在高糖和晚期糖基化终末产物（Advanced glycation end products，AGEs）刺激的人和小鼠足细胞中lncRNA CRNDE的表达水平明显升高，呈现时间依赖性和AGEs浓度依赖性。.2.在人和小鼠的足细胞中下调lncRNA CRNDE的表达可以改善AGEs诱导的足细胞损伤和凋亡。