miR-19 targets PTEN and mediates high mobility group protein B1(HMGB1)-induced proliferation and migration of human airway smooth muscle cells.

BACKGROUND:The abnormal proliferation and migration of airway smooth muscle (ASM) cells contributes to airway remodeling during asthma. MiR-19a has been demonstrated to promote cell proliferation and angiogenesis of several cancer types by regulating the PTEN/PI3K/AKT pathway. Our previous study has shown that High-mobility group box protein 1 (HMGB1) is involved in the pathogenesis of airway remodeling using a mouse model of chronic asthma. However, the effects of HMGB1 on proliferation and migration of ASM cells and its underlying mechanisms remain unknown. METHODS:Human ASM cells were obtained by primary explant techniques. MiR-19a expression was evaluated using qRT-PCR. Cell proliferation and migration were evaluated by the CCK-8 and the transwell migration assays, respectively. Transfection studies of ASM cells were performed to identify the underlying mechanisms. RESULTS:HMGB1 stimulated ASM cell proliferation and migration in a dose-dependent manner. The expression levels of miR-19a and the PTEN and AKT signaling proteins were also modulated by HMGB1. Functional studies indicated that overexpression of miR-19a enhanced the proliferation and migration of ASM cells, whereas inhibition of miR-19a decreased the proliferation and migration of ASM cells. Western blot analysis demonstrated that miR-19a negatively regulated PTEN expression and positively regulated p-AKT expression. MiR-19 only regulates the proliferation of HASM cells induced by HMGB1, but not PDGF, EGF, TGF-β1. Furthermore, we demonstrated that miR-19 contributed to the promoting effects of HMGB1 on ASM cells by targeting PTEN 3'-UTR. CONCLUSION:Our results demonstrated that HMGB1 induced proliferation and migration of ASM cells via the miR-19a /PTEN/AKT axis and provided direct evidence on the role of HMGB1 in ASM cells proliferation in vitro. The present study further indicated that miR-19a may be explored as a potential novel therapeutic target to reverse proliferation and migration of ASM cells.