基于m6A甲基化修饰的GRPR信号激活在高尿酸性肾病中的功能及机制研究

高尿酸性肾病(HN)系由高尿酸所致的肾损害，其发生率逐年升高且机制未明。预实验发现HN患者和小鼠血清中proGRP高表达，其受体GRPR在肾脏表达增加，可能与受尿酸刺激时发生m6A甲基化有关。此外，新型GRPR拮抗剂、沉默或敲除GRPR均抑制尿酸诱导的炎症反应，转录组测序发现沉默GRPR降低尿酸转运体URAT1和支架蛋白PDZK1表达，而数据库查询提示PDZK1/URAT1可能与炎性转录因子NF-κB存在相互作用。因此我们提出假设，GRPR mRNA的m6A甲基化上调GRPR, 进而可能通过NF-κB/PDZK1/URAT1信号轴参与尿酸重吸收、尿酸诱导的肾损伤和炎症。本课题综合运用GRPR全身敲除、肾小管上皮细胞特异性敲除、拮抗剂、MeRIP-qPCR、RNA pull down等手段，评估GRPR作为HN治疗靶点的潜力，以期为HN的药物开发提供新思路。

The incidence of renal damage caused by hyperuricemia is significantly increased, but the mechanism is not clear. Our pilot study showed that proGRP was highly expressed in the circulation of hyperuricemic nephropathy (HN) patients and mice, and the expression of GRPR was also increased in the kidney, which may be related to m6A methylation of GRPR mRNA induced by uric acid. Our preliminary data showed that GRPR antagonist, silencing or GRPR knockout significantly inhibited uric acid-induced inflammatory response. Mechanistically, transcriptome sequence analysis showed that silencing GRPR significantly reduced uric acid-induced uric acid transporter URAT1 and scaffold protein PDZK1 expressions. The result of database query suggests that PDZK1/URAT1 might interact with inflammatory transcription factor NF-κB. Therefore, we put forward a hypothesis that m6A methylation of GRPR mRNA increasing GRPR expression involves in uric acid reabsorption, uric acid induced renal dysfunction and inflammation via NF-κB/PDZK1/URAT1 axis. This project aims to evaluate the therapeutic potential of targeting GRPR in the treatment of HN by using GRPR knockout and renal tubule epithelial cell-specific knockout, silencing/overexpression cells, and antagonists and another methods, this may provide a new strategy for the treatment of HN.