miR-125b/Ets1 axis regulates transdifferentiation and calcification of vascular smooth muscle cells in a high-phosphate environment.
OBJECTIVE
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.


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.


CONCLUSIONS
Our study suggests that down-regulation of miR-125b after β-glycerophosphoric acid treatment facilitates VSMCs transdifferentiation and calcification through targeting Ets1.
Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, 262 Zhongshan North Road, Nanjing 210003, Jiangsu, China.
Ping
P
Wen
Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, 262 Zhongshan North Road, Nanjing 210003, Jiangsu, China.
Hongdi
H
Cao
Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, 262 Zhongshan North Road, Nanjing 210003, Jiangsu, China.
Li
L
Fang
Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, 262 Zhongshan North Road, Nanjing 210003, Jiangsu, China.
Hong
H
Ye
Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, 262 Zhongshan North Road, Nanjing 210003, Jiangsu, China.
Yang
Y
Zhou
Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, 262 Zhongshan North Road, Nanjing 210003, Jiangsu, China.
Lei
L
Jiang
Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, 262 Zhongshan North Road, Nanjing 210003, Jiangsu, China.
Weifang
W
Su
Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, 262 Zhongshan North Road, Nanjing 210003, Jiangsu, China.
Hongying
H
Xu
Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, 262 Zhongshan North Road, Nanjing 210003, Jiangsu, China.
Weichun
W
He
Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, 262 Zhongshan North Road, Nanjing 210003, Jiangsu, China.
Chunsun
C
Dai
Center for Kidney Disease, 2nd Affiliated Hospital, Nanjing Medical University, 262 Zhongshan North Road, Nanjing 210003, Jiangsu, China. Electronic address: jwyang@njmu.edu.cn.
Junwei
J
Yang
D000469:Alkaline Phosphatase / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001011:Aorta / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D015153:Blotting, Western; D002113:Calcification, Physiologic; D054338:Cell Transdifferentiation / Q000187:drug effects*; D002478:Cells, Cultured; D005455:Fluorescent Antibody Technique; D005994:Glycerophosphates / Q000494:pharmacology*; D035683:MicroRNAs / Q000235:genetics*; D008856:Microscopy, Fluorescence; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D050784:Proto-Oncogene Protein c-ets-1 / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D061205:Vascular Calcification / Q000378:metabolism / Q000473:pathology
C494043:Ets1 protein, rat; D005994:Glycerophosphates; C581261:MIRN125 microRNA, rat; D035683:MicroRNAs; D050784:Proto-Oncogene Protein c-ets-1; D012333:RNA, Messenger; D000469:Alkaline Phosphatase; C031463:beta-glycerophosphoric acid
Calcification; VSMCs; miR-125b