Galectin-1 inhibits PDGF-BB-induced proliferation and migration of airway smooth muscle cells through the inactivation of PI3K/Akt signaling pathway.

Childhood asthma is one of the most common chronic childhood diseases. Platelet-derived growth factor BB (PDGF-BB) induced airway smooth muscle cell (ASMC) proliferation and migration are involved in the pathogenesis of asthma. Galectin-1 (Gal-1) is a glycan-binding protein that has been found to be involved in the progression of asthma. However, the mechanism remains unclear. In the current study, we aimed to evaluate the role of Gal-1 in regulating the phenotype switching of ASMCs, which is an important mechanism in the pathogenesis of asthma. Our results showed that Gal-1 was markedly down-regulated in the samples from asthma patients. In vitro study also proved that Gal-1 expression was decreased in PDGF-BB-stimulated ASMCs. In addition, Gal-1 overexpression significantly inhibited PDGF-BB-induced ASMCs proliferation and migration, while Gal-1 knockdown exhibits opposite effects of Gal-1 overexpression. The PDGF-BB-caused reductions in expressions of α-smooth muscle actin (α-SMA), specific muscle myosin heavy chain (SM-MHC), and calponin were elevated by Gal-1 overexpression, but were deteriorated by Gal-1 knockdown in ASMCs. Furthermore, overexpression of Gal-1 inhibited PDGF-BB-stimulated PI3K/Akt activation in ASMCs. Notably, treatment with IGF-1, an activator of PI3K, reversed the effects of Gal-1 on ASMCs proliferation, migration, and phenotype switching. In conclusion, these findings showed that Gal-1 exerted inhibitory effects on PDGF-BB-stimulated proliferation, migration, and phenotype switching of ASMCs via inhibiting the PI3K/Akt signaling pathway. Thus, Gal-1 might be a promising target for the treatment of asthma.