LAUSR

ABSTRACT Fibroblast‐to‐myofibroblast differentiation is a highly important pathological characteristic of pulmonary fibrosis. In this study, we aimed to investigate the effects and mechanisms of baicalein on the differentiation of human lung fibroblasts. Baicalein reduced the levels of &agr;‐smooth muscle actin (&agr;‐SMA) mRNA and protein expression in TGF‐&bgr;1‐treated human lung fibroblasts. It also decreased the contents of collagen type I and fibronectin in time‐ and dose‐dependent manners, and retarded TGF‐&bgr;1‐stimulated &agr;‐SMA filament formation. Baicalein diminished the expression of miR‐21, and miR‐21 mimics partially antagonized the effects of baicalein. Additionally, Baicalein inhibited the miR‐21 transcriptor STAT3 activity but not AP‐1 activity. Moreover, the expression of Spry 1 protein, a miR‐21 known target, was improved by baicalein treatment, but the level of Smurf2 protein, another miR‐21 target, was not interfered. Collectively, these results demonstrated that baicalein can attenuate TGF‐&bgr;1‐induced human lung fibroblast differentiation by inhibiting the miR‐21 expression. Graphical abstract Figure. No Caption available. HighlightsBaicalein ameliorates human lung fibroblast differentiation.Baicalein retarded TGF‐&bgr;1‐stimulated &agr;‐SMA filament formation.Baicalein diminished the expression of miR‐21.MiR‐21 mimics antagonize the effect of baicalein on fibroblast differentiation.The effect of baicalein is related with the inhibition of miR‐21 expression.