Ping Wen1, Hongdi Cao1, Li Fang1, Hong Ye1, Yang Zhou1, Lei Jiang1, Weifang Su1, Hongying Xu1, Weichun He1, Chunsun Dai1, Junwei Yang2. 1. Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, 262 Zhongshan North Road, Nanjing 210003, Jiangsu, China. 2. Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, 262 Zhongshan North Road, Nanjing 210003, Jiangsu, China. Electronic address: jwyang@njmu.edu.cn.
Abstract
OBJECTIVES: Vascular calcification is highly prevalent in patients with chronic kidney disease (CKD) and contributes to increased risk of cardiovascular disease and mortality. Accumulated evidences suggested that vascular smooth muscle cells (VSMCs) to osteoblast-like cells transdifferentiation (VOT) plays a crucial role in promoting vascular calcification. MicroRNAs (miRNAs) are a novel class of small RNAs that negatively regulate gene expression via repression of the target mRNAs. In the present work, we sought to determine the role of miRNAs in VSMCs phenotypic transition and calcification induced by β-glycerophosphoric acid. APPROACH AND RESULTS: Primary cultured rat aortic VSMCs were treated with β-glycerophosphoric acid for different periods of time. In VSMCs, after β-glycerophosphoric acid treatment, the expressions of cbf β1, osteocalcin and osteopontin were significantly increased and SM-22β expression was decreased. ALP activity was induced by β-glycerophosphoric acid in a time or dose dependent manner. Calcium deposition was detected in VSMCs incubated with calcification media; then, miR-125b expression was detected by real-time RT PCR. miR-125b expression was significantly decreased in VSMCs after incubated with β-glycerophosphoric acid. Overexpression of miR-125b could inhibit β-glycerophosphoric acid-induced osteogenic markers expression and calcification of VSMCs whereas knockdown of miR-125b promoted the phenotypic transition of VSMCs and calcification. Moreover, miR-125b targeted Ets1 and regulated its protein expression in VSMCs. Downregulating Ets1 expression by its siRNA inhibited β-glycerophosphoric acid-induced the VSMCs phenotypic transition and calcification. CONCLUSION: Our study suggests that down-regulation of miR-125b after β-glycerophosphoric acid treatment facilitates VSMCs transdifferentiation and calcification through targeting Ets1.
OBJECTIVES:Vascular calcification is highly prevalent in patients with chronic kidney disease (CKD) and contributes to increased risk of cardiovascular disease and mortality. Accumulated evidences suggested that vascular smooth muscle cells (VSMCs) to osteoblast-like cells transdifferentiation (VOT) plays a crucial role in promoting vascular calcification. MicroRNAs (miRNAs) are a novel class of small RNAs that negatively regulate gene expression via repression of the target mRNAs. In the present work, we sought to determine the role of miRNAs in VSMCs phenotypic transition and calcification induced by β-glycerophosphoric acid. APPROACH AND RESULTS: Primary cultured rat aortic VSMCs were treated with β-glycerophosphoric acid for different periods of time. In VSMCs, after β-glycerophosphoric acid treatment, the expressions of cbf β1, osteocalcin and osteopontin were significantly increased and SM-22β expression was decreased. ALP activity was induced by β-glycerophosphoric acid in a time or dose dependent manner. Calcium deposition was detected in VSMCs incubated with calcification media; then, miR-125b expression was detected by real-time RT PCR. miR-125b expression was significantly decreased in VSMCs after incubated with β-glycerophosphoric acid. Overexpression of miR-125b could inhibit β-glycerophosphoric acid-induced osteogenic markers expression and calcification of VSMCs whereas knockdown of miR-125b promoted the phenotypic transition of VSMCs and calcification. Moreover, miR-125b targeted Ets1 and regulated its protein expression in VSMCs. Downregulating Ets1 expression by its siRNA inhibited β-glycerophosphoric acid-induced the VSMCs phenotypic transition and calcification. CONCLUSION: Our study suggests that down-regulation of miR-125b after β-glycerophosphoric acid treatment facilitates VSMCs transdifferentiation and calcification through targeting Ets1.
Authors: Sara Panizo; Manuel Naves-Díaz; Natalia Carrillo-López; Laura Martínez-Arias; José Luis Fernández-Martín; María Piedad Ruiz-Torres; Jorge B Cannata-Andía; Isabel Rodríguez Journal: J Am Soc Nephrol Date: 2015-07-17 Impact factor: 10.121