MicroRNA-485-3p Promotes the Inflammatory Response and Extracellular Matrix Deposition by Activating Wnt/β-Catenin Signaling in Human Airway Smooth Muscle Cells.

The aim of this study was to study the effects of microRNA (miR)-485-3p on the inflammatory response and extracellular matrix deposition of human airway smooth muscle cells (HASMCs). The levels of miR-485-3p and WIF1 in peripheral blood of pediatric asthma (PA) patients and controls were examined by quantitative real-time polymerase chain reaction (qRT-PCR). miR-485-3p inhibitor and mimic, together with negative control (NC) inhibitor/ mimic, were transfected into HASMCs treated with tumor necrosis factor (TNF)-α. The levels of eotaxin, interleukin (IL)-8, and IL-6 were analyzed by enzyme-linked immunosorbent assay (ELISA). Cellular immunofluorescence analysis of fibronectin was also performed. The target genes of miR-485-3p were predicted and validated using TargetScan and dual-luciferase reporter gene assay. The protein levels of IL-6, eotaxin, IL-8, collagen III, collagen I, MMP-9, TIMP-1, MMP-2, axin, β-catenin, phosphorylated β-catenin, GSK3β, p-GSK3β, and WIF1 were tested by Western blot. The level of miR-485-3p was increased, whereas expression of WIF1 was low in PA patients. In TNF-α-induced HASMCs, miR-485-3p overexpression promoted the inflammatory response and the accumulation of extracellular matrix. WIF1 was a direct target of miR-485-3p. Silencing miR-485-3p inhibited activation of Wnt/β-catenin signaling. The reductions in the inflammatory response and ECM accumulation caused by silencing miR-485-3p were induced by blocking Wnt/β-catenin signaling. Thus, miRNA-485-3p targets WIF1 and activates Wnt/β-catenin signaling, facilitating activation of the inflammatory response and ECM accumulation in HASMCs.