Ai Kai, Li Xiaozhou, Zhang Pan, Pan Jian, Li Huiling, He Zhibiao, Zhang Hongliang, Yi Lei, Kang Ye, Wang Yinhuai, Chen Junxiang, Li Yijian, Xiang Xudong, Chai Xiangping, Zhang Dongshan
Department of Emergency Medicine, Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, People's Republic of China.
Emergency Medicine and Difficult Diseases Institute, Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, People's Republic of China.
Mol Ther Nucleic Acids. 2022 Feb 28;28:77-86. doi: 10.1016/j.omtn.2022.02.015. eCollection 2022 Jun 14.
DNA methylation plays a pivotal role in the progression of renal fibrosis. Methyl-CpG-binding domain protein 2 (MBD2), a protein reader of methylation, is involved in the development of acute kidney injury (AKI) caused by vancomycin. However, the role and mechanism of action of MBD2 in renal remain unclear. In this study, MBD2 mediated extracellular matrix (ECM) production induced by TGF-β1 in Boston University mouse proximal tubule (BUMPT) cells，and upregulated the expression EGR1 to promote ECM production in murine embryonic NIH 3T3 fibroblasts. ChIP analysis demonstrated that MBD2 physically interacted with the promoter region of the CpG islands of EGR1 genes and then activated their expression by inducing hypomethylation of the promoter region. , PT-MBD2-KO attenuated unilateral ureteral obstruction (UUO)-induced renal tubulointerstitial fibrosis via downregulation of EGR1, which was demonstrated by the downregulation of fibronectin (FN), collagen I and IV, α-SMA, and EGR1. Injection of MBD2-siRNA attenuated the UUO- and I/R-induced renal fibrosis. Those molecular changes were verified by biopsies from patients with obstructive nephropathy (OB). These data collectively demonstrated that inhibition of MBD2 reduces renal fibrosis via downregulating EGR1, which could be a target for treatment of fibrotic kidney disease.
DNA甲基化在肾纤维化进展中起关键作用。甲基化CpG结合域蛋白2（MBD2）是一种甲基化蛋白阅读器，参与了万古霉素引起的急性肾损伤（AKI）的发展。然而，MBD2在肾脏中的作用和作用机制仍不清楚。在本研究中，MBD2介导了波士顿大学小鼠近端小管（BUMPT）细胞中由转化生长因子-β1诱导的细胞外基质（ECM）产生，并上调了早期生长反应蛋白1（EGR1）的表达，以促进小鼠胚胎NIH 3T3成纤维细胞中的ECM产生。染色质免疫沉淀分析表明，MBD2与EGR1基因的CpG岛启动子区域发生物理相互作用，然后通过诱导启动子区域的低甲基化来激活其表达。PT-MBD2基因敲除通过下调EGR1减轻了单侧输尿管梗阻（UUO）诱导的肾小管间质纤维化，这通过纤连蛋白（FN）、I型和IV型胶原、α-平滑肌肌动蛋白（α-SMA）和EGR1的下调得到证实。注射MBD2小干扰RNA减轻了UUO和缺血/再灌注（I/R）诱导的肾纤维化。这些分子变化在梗阻性肾病（OB）患者的活检中得到了验证。这些数据共同表明，抑制MBD2通过下调EGR1减少肾纤维化，这可能是治疗纤维化肾病的一个靶点。
