Effects of lentiviral-mediated p38 mitogen-activated protein kinase RNA interference on connective tissue growth factor expression in myocardial fibroblasts

Abstract

Objective To explore the effects of p38 mitogen-activated protein kinase (MAPK)short-hair RNA (shRNA) delivered by lentiviral vectors (PGLV) on connective tissue growth factor (CTGF) expression in myocardial fibroblasts.Methods The PGLN-shRNA was transfected into myocardial fibroblasts to to explore the role of p38MAPK pathway activation in transforming growth factor (TGF)-β-mediated myocardial fibrosis.The mRNA expression levels of p38MAPK and CTGF were detected by using reverse transcriptase-polymerase chain reaction (RT-PCR),and the protein expression levels of CTGF and α-smooth muscle actin (α-SMA) by using Western blotting.Results TGF-β stimulation increased p38MAPK and CTGF mRNA,and CTGF and α-SMA protein expression in myocardial fibroblasts (P ＜0.01).As compared with those in TGF-β group,PGLN-shRNA transfection decreased p38MAPK and CTGF mRNA,and CTGF and α-SMA protein expression in myocardial fibroblasts [(0.252 ± 0.041 vs.0.652±0.089,P＜0.01; 0.418 ±0.071 vs.0.838 ±0.099,P＜0.01; 0.418 ±0.076 vs.0.991 ±0.117,P＜0.01;0.465±0.069 vs.0.875 ± 0.100,P ＜ 0.05)].Conclusion TGF-β directly upregulates CTGF expression through p38MAPK pathway and gene silence of p38MAPK may protect TGF-β-mediated fibrosis in cardiac myoeytes. Key words: p38 mitogen-activated protein kinase; Lentiviral vectors; Connective tissue growth factor; RNA interference