Luo Qimei, Xia Xi, Luo Qingqing, Qiu Yue, Dong Lan, Zhao Chen, Peng Fenfen, Yu Jing, Huang Fengxian, He Feng
Department of Nephrology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China.
Key Laboratory of Nephrology, Ministry of Health and Guangdong Province, Guangzhou, China.
Kidney Dis (Basel). 2022 Mar 17;8(3):231-245. doi: 10.1159/000523847. eCollection 2022 May.
The aim of this study was to investigate the role and mechanism of long noncoding RNA (lncRNA) maternally expressed gene 3 (MEG3)-205 in renal inflammation and fibrosis in diabetic nephropathy (DN).
lncRNA microarray profiling was used to examine differentially expressed lncRNAs of kidney tissues in db/db mice compared to db/m mice. Mouse mesangial cells (mMCs) were cultured in vitro with advanced glycation end products (AGEs) via transfection with lncRNA MEG3-205 siRNAs or plasmids. The role of lncRNA MEG3-205 in vivo was examined in db/db mice treated with long-acting lncRNA MEG3-205 siRNA. The interaction between lncRNA MEG3-205 and let-7a was investigated using luciferase assay and RNA immunoprecipitation assay.
lncRNA MEG3-205 was markedly upregulated in renal tissues of db/db mice, DN patients, and AGEs-treated mesangial cells. Overexpression of lncRNA MEG3-205 promoted the secretion of pro-inflammatory cytokines and synthesis of extracellular matrix proteins in mesangial cells. Both lncRNA MEG3-205 and myeloid differentiation primary-response protein 88 (MyD88) could bind to let-7a, and lncRNA MEG3-205 overexpression can significantly rescue the silencing effect of let-7a on MyD88 protein expression in mMCs. Mechanistically, we identified that lncRNA MEG3-205 could act as a competing endogenous RNA by binding with let-7a and thus regulate MyD88. Knockdown of lncRNA MEG3-205 alleviated albuminuria and attenuated renal inflammation and fibrosis in db/db mice.
These findings indicated an important role of the lncRNA MEG3-205/let-7a/MyD88 axis in regulating renal inflammation and fibrosis in DN. Targeting lncRNA MEG3-205 might present a promising therapeutic strategy for DN.
本研究旨在探讨长链非编码RNA（lncRNA）母系表达基因3（MEG3）-205在糖尿病肾病（DN）肾炎症和纤维化中的作用及机制。
采用lncRNA芯片分析检测db/db小鼠与db/m小鼠肾脏组织中差异表达的lncRNAs。通过用lncRNA MEG3-205小干扰RNA（siRNAs）或质粒转染，将小鼠系膜细胞（mMCs）与晚期糖基化终产物（AGEs）进行体外培养。在用长效lncRNA MEG3-205 siRNA处理的db/db小鼠中检测lncRNA MEG3-205在体内的作用。使用荧光素酶报告基因检测和RNA免疫沉淀检测研究lncRNA MEG3-205与let-7a之间的相互作用。
lncRNA MEG3-205在db/db小鼠、DN患者及AGEs处理的系膜细胞肾组织中显著上调。lncRNA MEG3-205的过表达促进系膜细胞中促炎细胞因子的分泌和细胞外基质蛋白的合成。lncRNA MEG3-205和髓样分化初级反应蛋白88（MyD88）均可与let-7a结合，lncRNA MEG3-205的过表达可显著挽救let-7a对mMCs中MyD88蛋白表达的沉默作用。机制上，我们发现lncRNA MEG3-205可通过与let-7a结合作为竞争性内源RNA，从而调节MyD88。敲低lncRNA MEG3-205可减轻db/db小鼠的蛋白尿，并减轻肾脏炎症和纤维化。
这些发现表明lncRNA MEG3-205/let-7a/MyD88轴在调节DN肾炎症和纤维化中起重要作用。靶向lncRNA MEG3-
