STAT1/LncRNA PPA/JNK信号转导在糖尿病肾病足细胞凋亡中的作用及机制研究

Diabetic nephropathy (DN) is common and refractory microvascular complication of diabetes. It is known that podocyte apoptosis is an important reason for the development of diabetic nephropathy, however, the mechanism is not clear. In our preliminary studies, we applicated the lncRNAs microarray technology to detect and screen the specific lncRNAs of diabetic nephropathy, and validated using quantitative real-time polymerase chain reaction. We found that LncRNA PPA was significantly upregulated in kidney tissue of diabetic nephropathy mice and high glucose stimulated podocytes. Over-expression of LncRNA PPA can significantly promote podocyte apoptosis. We applicated bioinformatics analysis and CHIP-PCR experiments and confirmed that STAT1 can bind to the promoter region of LncRNA PPA. We used the gene chip to screen different genes regulated by LncRNA PPA, and found that LncRNA PPA can make the JNK signal molecules enrichment, moreover, blocking JNK signal activation can reverse the effect of LncRNA PPA in vitro. Therefore, we propose that LncRNA PPA can be transcripted by STAT1, then can activate JNK signal, which promoting podocyte apoptosis in diabetic nephropathy. We intend to further confirm that STAT1/LncRNA PPA/JNK signal regulation, and explore the importance and significance of the incident in podocyte apoptosis in diabetic nephropathy. The study may provide new ideas for the 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，足细胞凋亡是DN早期出现蛋白尿和肾功能损害的重要原因，然而其机制尚不清楚。我们在前期研究中，应用LncRNAs芯片筛选到DN特异表达的LncRNA PPA；上调表达LncRNA PPA能促进足细胞凋亡；应用生物信息学分析联合CHIP-PCR技术预测并证实STAT1能结合LncRNA PPA的启动子区域；采用基因芯片筛选LncRNA PPA调控的基因，发现LncRNA PPA富集JNK信号通路的分子；且体外阻断JNK信号能有效逆转LncRNA PPA的促凋亡作用。因此，我们提出DN时LncRNA PPA被STAT1转录调控，上调表达的LncRNA PPA能激活JNK信号，促进足细胞凋亡损伤。本项目拟证实STAT1/LncRNA PPA/JNK信号转导的调控，并探讨这一事件对DN足细胞凋亡的重要性和意义，为临床防治DN提供新的思路。

糖尿病肾病（DN）是糖尿病常见且难治的微血管并发症，DN早期出现足细胞数量减少，胞体缩小，足突融合以及与基底膜分离，引起蛋白尿导致肾功能恶化进展。因此，足细胞损伤是糖尿病肾病早期重要的病理基础，阐明DN早期足细胞损伤的机制是本领域的研究重点。本项目应用LncRNAs芯片筛选到DN特异表达的LncRNA PPA；上调表达LncRNA PPA能促进足细胞凋亡；应用生物信息学分析联合CHIP-PCR技术预测并证实STAT1能结合LncRNA PPA的启动子区域，转录调控LncRNA PPA的表达；采用RNA-pull down & 质谱鉴定分析出LncRNA PPA的结合蛋白ASK1， LncRNA PPA与ASK1蛋白结合并通过增强其稳定性来增加其蛋白表达。采用基因芯片筛选LncRNA PPA调控的基因，发现LncRNA PPA富集JNK信号通路的分子；且体外阻断JNK信号能有效逆转LncRNA PPA的促凋亡作用。因此，本项目揭示DN足细胞中LncRNA PPA被STAT1转录调控，且LncRNA PPA可与ASK1蛋白结合，通过增强蛋白稳定性来增加ASK1的表达，进一步激活ASK1/JNK途径信号介导足细胞凋亡损伤。本项目阐明了LncRNA PPA在DN足细胞凋亡的重要性和意义，为临床防治DN提供新的思路，即临床有望通过下调LncRNA PPA水平，或者阻断ASK1/JNK途径信号减轻DN足细胞凋亡损伤及蛋白尿。