Li Li-Min, Hou Dong-Xia, Guo Ya-Lan, Yang Jun-Wei, Liu Yuan, Zhang Chen-Yu, Zen Ke
Jiangsu Diabetes Center, State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Jiangsu 210093, China
J Immunol. 2011 Feb 15;186(4):2552-60. doi: 10.4049/jimmunol.1001633. Epub 2011 Jan 12.
Advanced glycation end products (AGEs) delay spontaneous apoptosis of monocytes and contribute to the development of inflammatory responses. However, the mechanism by which AGEs affect monocyte apoptosis is unclear. We studied the role of microRNA-214 (miR-214) and its target gene in AGE-induced monocytic apoptosis delay. Using microRNA (miRNA) microarray and stem-loop, quantitative RT-PCR assay, we studied genome-wide miRNA expression in THP-1 cells treated with or without AGEs. Significant upregulation of miR-214 was consistently observed in THP-1 and human monocytes treated with various AGEs, and AGE-induced monocytic miR-214 upregulation was likely through activation of receptor for AGEs. A striking increase in miR-214 was also detected in monocytes from patients with chronic renal failure. Luciferase reporter assay showed that miR-214 specifically binds to the phosphatase and tensin homolog (PTEN) mRNA 3'-untranslated region, implicating PTEN as a target gene of miR-214. PTEN expression is inversely correlated with miR-214 level in monocytes. Compared with normal monocytes, AGE-treated monocytes and monocytes from chronic renal failure patients exhibited lower PTEN levels and delayed apoptosis. Overexpression of pre-miR-214 led to impaired PTEN expression and delayed apoptosis of THP-1 cells, whereas knockdown of miR-214 level largely abolished AGE-induced cell survival. Our findings define a new role for miR-214-targeting PTEN in AGE-induced monocyte survival.
晚期糖基化终末产物（AGEs）可延迟单核细胞的自发凋亡，并促进炎症反应的发展。然而，AGEs影响单核细胞凋亡的机制尚不清楚。我们研究了微小RNA-214（miR-214）及其靶基因在AGE诱导的单核细胞凋亡延迟中的作用。使用微小RNA（miRNA）微阵列和茎环定量逆转录-聚合酶链反应（RT-PCR）分析，我们研究了在有或无AGEs处理的THP-1细胞中的全基因组miRNA表达。在用各种AGEs处理的THP-1细胞和人单核细胞中，始终观察到miR-214的显著上调，并且AGE诱导的单核细胞miR-214上调可能是通过晚期糖基化终末产物受体的激活。在慢性肾衰竭患者的单核细胞中也检测到miR-214显著增加。荧光素酶报告基因分析表明，miR-214特异性结合磷酸酶和张力蛋白同源物（PTEN）mRNA的3'-非翻译区，提示PTEN是miR-214的靶基因。单核细胞中PTEN的表达与miR-214水平呈负相关。与正常单核细胞相比，经AGE处理的单核细胞和慢性肾衰竭患者的单核细胞表现出较低的PTEN水平和延迟的凋亡。前体miR-214的过表达导致PTEN表达受损和THP-1细胞凋亡延迟，而miR-214水平的敲低在很大程度上消除了AGE诱导的细胞存活。我们的研究结果确定了miR-214靶向PTEN在AGE诱导的单核细胞存活中的新作用。
