miR-184 Inhibits Hypertrophic Scar Through Regulating Phosphatidylinositol 3-Kinase (PI3K)/Protein Kinase B (AKT) Signaling Pathway

Abstract

Hypertrophic scar (HS) is a process of tissue repair and healing, and excessive fibrosis of local tissue leads to scar formation. During HS formation, fibroblasts (Fb) proliferate, synthesize and secrete and promote HS development. miR-184 regulates skin formation and tissue development. However, miR-184’s role in HS remains unclear. miR-184 expression in HS patients and normal healthy (Control) tissues was measured by real-time PCR. pAKT expression was analyzed by Western blot. Fb cells from human HS were cultured and divided into 2 groups, siRNA NC group and miR-184 siRNA group followed by analysis of miR-184 expression by real time PCR, cell proliferation by MTT assay, secretion of inflammatory factors IL-1β and IL-6 by ELISA, as well as expression of pAKT and AKT by western blot. Compared with control group, miR-184 and pAKT expression was significantly increased in the HS group. Transfection of miR-184 siRNA into Fb significantly downregulated miR-184 expression, inhibited cell proliferation, promoted Caspase 3 activity, decreased IL-1β and IL-6 secretion, and reduced pAKT level (P < 0.05). miR-184 expression is increased in hypertrophic scar tissue. Down-regulation of miR-184 expression in proliferative scar tissue fibroblasts can down-regulate PI3K/AKT signaling pathway, inhibit inflammation, promote apoptosis, inhibit fibroblast proliferation, and regulate hypertrophic scar formation.