DNA羟化酶TET2在肾移植慢性排斥过程巨噬细胞-肌成纤维细胞转化中的作用研究

Interstitial fibrosis is one of most important cause of chronic kidney graft dysfunction. Macrophage is involved in renal transplant-induced fibrosis. Our previous study has revealed that macrophage to myofibroblast played an important regulatory roles in accelerating chronic renal interstitial fibrosis, but its molecular mechanism has not been fully elucidated, which signal pathway remains to be further clarified. Some studies showed that DNA hydroxylase TET2 participated in regulating the functions of macrophage. Our previous data also indicated that TET2 knockout resulted in higher expression levels of NLRP3 and IL6 in chronic renal allograft. Also, higher expression levels of α-SMA and Collagen were seen in TET2 knockout mice compared with WT mice which all received renal allograft. Therefore, we infer that TET2 has an important regulatory role in the process of MMT. In order to clarify the roles and signal transduction pathway of TET2 in the process of MMT at the molecular, cellular and whole animal levels, we plan to use multiple transgenic mouse lines and AAV knockdown technology to construct double knockout or knockdown mice. We believe this project fully elucidates the role of TET2 in the process of MMT and its underlying mechanism, which will provide new clues for developing new treatment approaches for renal fibrosis.

在慢性移植肾损伤中，间质纤维化是造成移植物失功一个重要的因素。炎症巨噬细胞与肾移植的纤维化密切相关。本研究组最近发表在JASN杂志的研究结果表明巨噬细胞向肌成纤维细胞转化加快慢性移植肾间质纤维化进程，但其分子机制尚未完全阐明。已有证据表明DNA羟化酶TET2参与巨噬细胞功能调控。前期研究组初步发现在TET2敲除小鼠慢性移植肾脏中NLRP3和IL6的表达量明显比正常小鼠高；同时，TET2敲除可致移植慢性排斥小鼠肾脏的α-SMA和Collagen I的表达明显增加。因此我们推测TET2在MMT发生具有重要调控作用。本项目拟利用多种转基因小鼠和AAV病毒技术制备多基因敲除或沉默小鼠慢性移植肾模型，在动物、细胞和分子水平上明确TET2在MMT发生的重要作用以及其介导的信号通路。通过以上研究，本项目将系统揭示TET2抑制移植肾MMT的分子机制，为发展肾移植慢性排斥纤维化诊断和治疗新方法打下基础。

在慢性移植肾损伤中，间质纤维化是造成移植物失功一个重要的因素，巨噬细胞与肾移植的纤维化密切相关。课题组前期研究结果表明巨噬细胞向肌成纤维细胞转化加快慢性移植肾间质纤维化进程，但其分子机制尚未完全阐明。已有证据表明DNA羟化酶TET2参与巨噬细胞功能调控。课题组研究发现在TET2敲除小鼠慢性移植肾脏中NLRP3和IL6的表达量明显比正常小鼠高；同时，TET2敲除可致移植慢性排斥小鼠肾脏的α-SMA和Collagen I的表达明显增加。因此课题组得出结论TET2在MMT发生具有重要调控作用，揭示TET2抑制移植肾EMT的分子机制，在课题研究过程中共发表相关论文12篇，培养博士研究生4名，有1名课题参与人晋升为高级职称，召开了3次西湖论坛、1次中德研讨会、1次内地-香港研讨会，促进课题交流讨论，为发展肾移植慢性排斥纤维化诊断和治疗新方法打下基础。