Effect and mechanism of miRNA-92a regulating SHH pathway on promoting vascular regeneration after myocardial I/R injury / 中华老年心脑血管病杂志

ABSTRACT

Objective To explore the effect and mechanism of miR-92a regulating sonic hedgehog(SHH)pathway on promoting vascular regeneration after myocardial ischemia-reperfusion(I/R)injury.Methods Primary cardiomyocytes were isolated from newborn SD rats(1 to 3 days old),and then cultured to establish a cellular model of hypoxia/reoxygenation injury.The cardiomyo-cytes were divided into cardiomyocyte normoxia group and cardiomyocyte I/R group.After miR-92a mimic and inhibitor were respectively transfected into primary cardiomyocytes to overex-press or lower its expression,the cells were then grouped into control,I/R,miR-92a mimic and in-hibitor groups.CCK-8 assay was used to determine cell viability,flow cytometry was employed to detect cell apoptosis,ELISA and QT-PCR were applied to detect the expression of VEGF,b-FGF and Ang-1,and Western blotting was performed to measure the expression of SHH signaling pathway related proteins.Results The expression level of miR-92a was significantly higher in the cardiomyocytes from the ischemia/reperfusion(I/R)group than the normoxia group(3.89±0.29 vs 1.53±0.19,P＜0.01).Statistical differences were observed among the control group,miR-92a inhibitor group,I/R group,and miR-92a mimic group in the protein levels of SHH(0.57±0.13 vs 0.51±0.11 vs 0.24±0.03 vs 0.14±0.02,P＜0.01),of Smoothened(SMO,0.53±0.12 vs 0.49± 0.10 vs 0.14±0.04 vs 0.09±0.01,P＜0.01),of glioma-associated oncogene homolog 1(Gli-1,0.56±0.14 vs 0.50±0.13 vs 0.15±0.03 vs 0.08±0.01,P＜0.01),and of glioma-associated onco-gene homolog 2(Gli-2,0.58±0.11 vs 0.49±0.12 vs 0.18±0.02 vs 0.11±0.03,P＜0.01).Conclu-sion MiR-92a is abnormally highly expressed in cardiomyocytes after I/R injury,and inhibition of miR-92a can activate SHH signaling pathway to promote the expression of angiogenesis factors effectively.