摘要
Although microRNAs （miRNAs） have been intensively studied in cardiac fibrosis, their roles in drug-mediated anti-fibrotic therapy are still unknown. Previously, Pioglitazone attenuated cardiac fibrosis and increased miR-711 experimentally. We aimed to explore the role and mechanism of miR-711 in pioglitazone-treated myocardial infarction in rats. Our results showed that pioglitazone significantly reduced collagen-I levels and increased miR-711 expression in myocardial infarction heart. Pioglitazone increased the expression of miR-711 in cardiac fibroblasts, and overexpression of miR-711 suppressed collagen-I levels in angiotensin II （Ang II）-treated or untreated cells. Transfection with antagomir-711 correspondingly abolished the pioglitazone-induced reduction in collagen-I levels. Bioinformatics analysis identified SP1, which directly promotes collagen-I synthesis, as the putative target of miR-711. This was confirmed by luciferase assay and western blot analysis. Additionally, increased SP1 expression was attenuated by pioglitazone in myocardial infarction heart. Furthermore, transfection of antago- mir-711 attenuated pioglitazone-reduced SP1 expression in cardiac fibroblasts with or without Ang II stimulation. We conclude that pioglitazone up-regulated miR-711 to reduce collagen-I levels in rats with myocardial infarction. The miR-711-SPl-collagen-I pathway may be involved in the anti-fibrotic effects of pioglitazone. Our findings may provide new strategies for miRNA-based anti-fibrotic drug research.
Although microRNAs(miRNAs) have been intensively studied in cardiac fibrosis,their roles in drug-mediated anti-fibrotic therapy are still unknown.Previously,Pioglitazone attenuated cardiac fibrosis and increased miR-711 experimentally.We aimed to explore the role and mechanism of miR-711 in pioglitazone-treated myocardial infarction in rats.Our results showed that pioglitazone significantly reduced collagen-I levels and increased miR-711 expression in myocardial infarction heart.Pioglitazone increased the expression of miR-711 in cardiac fibroblasts,and overexpression of miR-711 suppressed collagen-I levels in angiotensin II(Ang II)-treated or untreated cells.Transfection with antagomir-711 correspondingly abolished the pioglitazone-induced reduction in collagen-I levels.Bioinformatics analysis identified SP1,which directly promotes collagen-I synthesis,as the putative target of miR-711.This was confirmed by luciferase assay and western blot analysis.Additionally,increased SP1 expression was attenuated by pioglitazone in myocardial infarction heart.Furthermore,transfection of antagomir-711 attenuated pioglitazone-reduced SP1 expression in cardiac fibroblasts with or without Ang II stimulation.We conclude that pioglitazone up-regulated miR-711 to reduce collagen-I levels in rats with myocardial infarction.The miR-711-SP1-collagen-I pathway may be involved in the anti-fibrotic effects of pioglitazone.Our findings may provide new strategies for miRNA-based anti-fibrotic drug research.
基金
supported by the National Natural Science Foundation of China (81100164,31271212,81070196,81030001)
the Research Fund for the Doctoral Program of Higher Education (20100001110101,20110001120015)
the Program for New Century Excellent Talents in University,the Beijing Talents Foundation
