MicroRNA-320 expression in myocardial microvascular endothelial cells and its relationship with insulin-like growth factor-1 in type 2 diabetic rats.
1. The aim of the present study was to determine the role of myocardial microvascular endothelial cells (MMVEC) in impaired angiogenesis of type 2 diabetic Goto-Kakizaki (GK) rats. 2. A microRNA (miRNA) microarray was used to assess miRNA expression in MMVEC from GK and Wistar rats. Upregulation of miRNA-320 was observed in MMVEC from GK rats using real-time reverse transcription-polymerase chain reaction (RT-PCR). 3. So far, nine miRNAs have been reported to target angiogenic factors and/or receptors, including kinase insert domain containing receptor (Flk-1), insulin-like growth factor 1 (IGF-1) and insulin-like growth factor 1 receptor (IGF-1R). The predicted genes targeted by miR-320 include Flk-1, IGF-1 and IGF-1R. Western blot analysis and RT-PCR were used to analyse the protein and mRNA expression, respectively, of the putative genes IGF-1 and IGF-1R. The expression of IGF-1 and IGF-1R proteins decreased significantly in diabetic MMVEC. However, the expression of IGF-1 mRNA increased rather than decreased. The mRNA expression of IGF-1R did not differ significantly between diabetic and control MMVEC. 4. Transfection of an miR-320 inhibitor into MMVEC from GK rats confirmed that miR-320 impaired angiogenesis. The proliferation and migration of diabetic MMVEC improved after transfection of the miR-320 inhibitor. In addition, the miR-320 inhibitor significantly increased the expression of IGF-1 protein, but had no effect on the expression of IGF-1R. 5. Eleven miRNAs were upregulated in MMVEC from GK rats compared with those in Wistar rats: let-7e, miR-129, miR-291-5p, miR-320, miR-327, mir-333, miR-363-5p, miR-370, miR-494, miR-503 and miR-664. 6. The results indicate that upregulation of miR-320 in MMVEC from GK rats may be responsible for the inconsistency between the expression of IGF-1 protein and mRNA and therefore related to impaired angiogenesis in diabetes. Transfection of an miR-320 inhibitor may be a therapeutic approach for the treatment of impaired angiogenesis in diabetes.
Wang
X H
XH
Department of Physiology and Pathophysiology, Shanghai Medical College, Fudan University, Shanghai, China.
Qian
R Z
RZ
Zhang
W
W
Chen
S F
SF
Jin
H M
HM
Hu
R M
RM
D000818:Animals; D002478:Cells, Cultured; D003331:Coronary Vessels / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D003921:Diabetes Mellitus, Experimental / Q000235:genetics / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics / Q000378:metabolism*; D042783:Endothelial Cells / Q000378:metabolism* / Q000502:physiology; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis* / Q000235:genetics; D035683:MicroRNAs / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D046228:Microarray Analysis; D055806:Microvessels / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D009206:Myocardium / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D015854:Up-Regulation
C000602002:MIRN320 microRNA, rat; D035683:MicroRNAs; D007334:Insulin-Like Growth Factor I