Antagonist of microRNA‐21 improves balloon injury‐induced rat iliac artery remodeling by regulating proliferation and apoptosis of adventitial fibroblasts and myofibroblasts

Abstract

Molecular pathways involved in adventitial fibroblasts (AFs) and myofibroblasts (MFs) proliferation and apoptosis contribute to vascular remodeling. MicroRNA-21 (miR-21) plays an important role in regulating cellular proliferation and apoptosis of many cell types; however, the effect of miR-21 on AFs and MFs is still unknown. In this study, we found that miR-21 was expressed in AFs and overexpressed in MFs. Inhibition of miR-21 decreased proliferation and increased apoptosis of AFs and MFs, and overexpression of miR-21 with pre-miR-21 had the reverse effect. Programmed cell death 4 (PDCD4), related to cell proliferation and apoptosis, was validated as a direct target of miR-21 by dual-luciferase reporter assay and gain and loss of function of miR-21 in AFs and MFs. PDCD4 knockdown with siRNA partly rescued the reduced proliferation with miR-21 inhibition and alleviated the increased apoptosis induced by miR-21 inhibition in AFs and MFs. Moreover, increasing PDCD4 expression by miR-21 inhibition significantly decreased JNK/c-Jun activity. In contrast, decreasing PDCD4 expression by pre-miR-21 treatment increased JNK/c-Jun activity, while the effect of miR-21 inhibition on JNK/c-Jun activity could be rescued by PDCD4 siRNA. Moreover, miR-21 inhibition could regulate proliferation and apoptosis of vascular AFs and MFs in vivo. Furthermore, miR-21 inhibition reversed vascular remodeling induced by balloon injury. In summary, our findings demonstrate that miR-21 may have a critical role in regulating proliferation and apoptosis of AFs and MFs, and PDCD4 is a functional target gene involved in the miR-21-mediated cellular effects in vascular remodeling by a miR-21/PDCD4/JNK/c-Jun pathway.

MiR-21 confers resistance against CVB3-induced myocarditis by inhibiting PDCD4-mediated apoptosis

“…Additionally, anti-apoptosis approaches signi cantly improved CVB3-induced heart injury [32,33], further con rming the pathological role of apoptosis in the acute myocarditis. Our results were in line with previous studies that show miR-21 targeting PDCD4 to produce antiapoptotic e ect; however, these studies are mainly focused on the elds of tumor [34][35][36] and vascular diseases [37,38]. Only a few studies report that miR-21 exerts an anti-apoptotic e ect by targeting PDCD4 in heart diseases.…”

Pathogenic arterial remodeling: the good and bad of microRNAs

“…3). Alternatively, inhibition of miR-21 also enhances apoptosis and reduces proliferation of adventitial fibroblasts and myofibroblasts by derepressing programmed cell death 4 expression and thus activates the JNK/c-Jun pathway (86). More recently, miR-21 has been found to promote the growth of human pulmonary SMCs in vitro (95).…”

MicroRNA-21 Affects Proliferation and Apoptosis by Regulating Expression of PTEN in Human Keloid Fibroblasts

“…Adherent fibroblasts in a 96-well plate (Nest Scientific, Rahway, N.J.) plated at a density of 5 × 10 3 cells/well were transfected for 24 hours and incubated with 5-ethynyl-2′-deoxyuridine for 2 hours. 22 Cells were washed twice with phosphate-buffered saline and then fixed with 4% paraformaldehyde in phosphatebuffered saline for 30 minutes at room temperature. After washing with phosphate-buffered saline followed by incubation with 2 mg/ml amino acetic acid for 5 minutes, the cells were permeabilized with 0.5% Triton X-100 (Sigma, St. Louis, Mo.)…”