Liu Xiujuan, Fu Bo, Chen Dapeng, Hong Quan, Cui Jing, Li Jin, Bai Xueyuan, Chen Xiangmei
Department of Nephrology, State Key Laboratory of Kidney Diseases, Chinese PLA General Hospital and Medical College, Beijing 100853, China; Department of Nephrology, 94 Hospital of Chinese PLA, Nanchang, Jiangxi, 330002, China.
Department of Nephrology, State Key Laboratory of Kidney Diseases, Chinese PLA General Hospital and Medical College, Beijing 100853, China.
Exp Cell Res. 2015 Aug 15;336(2):192-203. doi: 10.1016/j.yexcr.2015.07.006. Epub 2015 Jul 10.
The molecular mechanism of kidney aging is not well understood, but the abnormal expression of miRNAs with aging is considered to be an important contributor. miR-184 and miR-150 were screened using a miRNA microarray and qRT-PCR and found to be significantly upregulated in 24-month-old rats. Rat renal primary glomerular mesangial cells (GMCs) were isolated from 3-month and 24-month-old rats for the in vitro analysis of the roles of miR-184 and miR-150 in kidney aging. Bioinformatics analyses suggested that Rab1a and Rab31, which are associated with cell autophagy, were targeted by both miR-184 and miR-150. miR-184 and miR-150 were increased significantly in aging GMCs versus young cells, while Rab1a and Rab31 were significantly lower in aging cells. Furthermore, dual luciferase reporter assays revealed that miR-184 and miR-150 bound to the 3'-UTR of Rab1a and Rab31 mRNAs. Transfection of miR-184 and miR-150 mimics into young GMCs suppressed the expression of Rab1a and Rab31. Transfected cells showed lower autophagy activities and higher levels of cellular oxidative products, leading to the aging of young GMCs. However, miR-184 and miR-150 inhibitors promoted autophagy and reduced oxidative damage by upregulating Rab1a and Rab31 in old GMCs. In conclusion, miR-184 and miR-150 inhibited autophagy, promoting GMC aging.
肾脏衰老的分子机制尚未完全明确,但随着衰老过程中miRNA的异常表达被认为是一个重要因素。通过miRNA芯片和qRT-PCR筛选发现,miR-184和miR-150在24月龄大鼠中显著上调。从3月龄和24月龄大鼠分离出大鼠肾原代肾小球系膜细胞(GMCs),用于体外分析miR-184和miR-150在肾脏衰老中的作用。生物信息学分析表明,与细胞自噬相关的Rab1a和Rab31是miR-184和miR-150的靶标。与年轻细胞相比,衰老GMCs中miR-184和miR-150显著增加,而Rab1a和Rab31在衰老细胞中显著降低。此外,双荧光素酶报告基因检测显示,miR-184和miR-150与Rab1a和Rab31 mRNA的3'-UTR结合。将miR-184和miR-150模拟物转染到年轻GMCs中可抑制Rab1a和Rab31的表达。转染后的细胞显示出自噬活性降低和细胞氧化产物水平升高,导致年轻GMCs衰老。然而,miR-184和miR-150抑制剂通过上调老年GMCs中的Rab1a和Rab31来促进自噬并减少氧化损伤。总之,miR-184和miR-150抑制自噬,促进GMC衰老。