MiR-23b controls TGF-β1 induced airway smooth muscle cell proliferation via TGFβR2/p-Smad3 signals

Background: Abnormal proliferation of ASM (airway smooth muscle) directly contributes to the airway remodeling during development of lung diseases such as asthma. Here we report that a specific microRNA (miR-23b) controls ASMCs proliferation through directly inhibiting TGF beta R2/p-Smad3 pathway. Methods: The expression of miR-23b in ASMCs was detected by quantitative real-time polymerase chain reaction (RT-PCR). The effects of miR-23b on cell proliferation and apoptosis of ASMCs were assessed by transient transfection of miR-23b mimics and inhibitor. The target gene of miR-23b and the downstream pathway were further investigated. Results: Overexpression of miR-23b significantly inhibited TGF-beta 1-induced ASMCs proliferation and promoted apoptosis. RT-PCR and Western blotting analysis showed miR-23b negatively regulates the expression of TGF beta R2 and p-Smad3 in ASMCs. Subsequent analyses demonstrated that TGF beta R2 was a direct and functional target of miR-23b, which was validated by the dual luciferase reporter assay. Conclusions: MiR-23b may function as an inhibitor of airway smooth muscle cells proliferation through inactivation of TGF beta R2/p-Smad3 pathway. (C) 2015 Elsevier Ltd. All rights reserved.