MiRNA-1202 promotes the TGF-β1-induced proliferation, differentiation and collagen production of cardiac fibroblasts by targeting nNOS

Abstract

Background Atrial fibrillation (AF) is a clinically common arrhythmia that affects human health. Myocardial fibrosis serves as an important contributor to AF. Recently, miRNA-1202 have been reported to be up-regulated in AF. However, the role of miRNA-1202 and its mechanism in myocardial fibrosis remain unclear. Methods Human cardiac fibroblasts (HCFs) were used to construct a fibrosis model by TGF-β1 induction. The expression of miR-1202 was measured by qRT-PCR. Cell proliferation was assessed by CCK-8 assays. Protein expression levels were measured by western blot. Collagen accumulation was measured by ELISA. The relationship between miR-1202 and nNOS was investigated by luciferase reporter assays. Results MiR-1202 expression was obviously increased in HCFs and was both time- and dose-independent. MiR-1202 could increase the proliferation and collagen I, collagen III, and α-SMA levels with or without TGF-β1. MiR-1202 could also increase TGF-β1 and p-Smad2/3 protein levels in comparison to the control group. However, they were obviously decreased after inhibitor transfection. MiR-1202 targets nNOS for negative regulation of HCFs fibrosis by decreasing cell differentiation, collagen deposition and the activity of the TGF-β1/Smad2/3 pathway. Co-transfection of miR-1202 inhibitor and siRNA of nNOS inhibited nNOS protein expression, thereby enhancing the HCFs proliferation. Furthermore, co-transfection of the miR-1202 inhibitor and siRNA of nNOS significantly promoted collagen I, collagen III, TGF-β1, Smad2/3 and α-SMA protein expression and Smad2/3 protein phosphorylation. These findings suggested that miR-1202 promotes HCFs transformation to a pro-fibrotic phenotype by targeting nNOS through activating the TGF-β1/Smad2/3 pathway.

Molecular and Cellular Mechanism of Action of Chrysotile Asbestos in MRC5 Cell Line

“…But increasing the expression of miR-376b-3p, on the contrary, inhibits the proliferation of fibroblasts, causing their premature aging [53]. miR-1202 promotes fibrosis by inducing TGF-β1 [54]. According to our assumptions, chrysotile asbestos could cause changes in the expression of these microRNAs.…”

Mechanism of action of non-coding RNAs and traditional Chinese medicine in myocardial fibrosis: Focus on the TGF-β/Smad signaling pathway

“…TGF-β induces collagen deposition in the ECM, and some miRNAs inhibit collagen production by regulating the TGF-β/Smad signaling pathway, thereby inhibiting ECM deposition, and alleviating cardiac fibrosis. Xiao et al ( Xiao et al, 2021 ) discovered that miR-1202 promoted the proliferation, differentiation, and collagen synthesis of HCFs by activating the TGF-β1/Smad2/3 signaling pathway, and downregulated the nNOS by binding to target sites in its mRNA. While, nNOS protected HCFs from TGF-β1-induced differentiation and collagen synthesis via the TGF-β1/Smad2/3 pathway.…”

Non-coding RNA and arrhythmias: expression, function, and molecular mechanism

“… 30 Other studies also demonstrated that miR-21 targeted Smad7, 31 miR-29b targeted TGF-βRI, 32 miR-135b targeted TGF-βRI, TGFβ-RII, and Smad2, 33 and miR-23b-3p and miR-27b-3p targeted two different sites in 3'-UTR of TGF-βRIII to participate in atrial fibrosis ( Table 1 ). 34 Additionally, miRNAs have been observed to target molecules linked with TGF-β1 signalling pathway, such as hsa-miR-4443 targeted THBS1, 35 miRNA-1202 targeted nNOS, 36 and miR-21 regulated WW domain-containing protein 1 ( Table 1 ). 37 All of these indicated that miRNAs associated with TGF-β1/Smads signalling may be attractive therapeutic targets, and future studies are needed to further explore whether these miRNAs can be used to develop new drugs, thereby achieving clinical translation.…”