RT Journal Article
SR Electronic
T1 Inhibition of the sonic hedgehog pathway at the primary cilium prevents the effect of TGF-beta 1 on alveolar epithelial cells
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP P3770
VO 40
IS Suppl 56
A1 Elika Farrokhi Moshai
A1 Arnaud Mailleux
A1 Valérie Besnard
A1 Stéphanie Brayer
A1 Monique Dehoux
A1 Bruno Crestani
YR 2012
UL http://erj.ersjournals.com/content/40/Suppl_56/P3770.abstract
AB Introduction. The mesenchymal differentiation of alveolar epithelial cells induced by Transforming Growth Factor-beta1 (TGF-beta1), also called Epithelial Mesenchymal Transition (EMT), may contribute to Idiopathic Pulmonary Fibrosis (IPF). The Sonic Hedgehog (SHH) pathway is involved in epithelial cells-fibroblasts interaction during fetal lung development and lung fibrogenesis in adult lung. Previously, our laboratory has demonstrated that the SHH pathway is necessary to the action of TGF-beta 1 in human pulmonary fibroblasts (Cigna et al. in revision).Aims.We hypothesized that the SHH pathway could play a role in mesenchymal differentiation of alveolar epithelial cells induced by TGF-beta 1.Methods. The A549 cell line or primary alveolar epithelial murine cells are pre-treated 1h with agonists (recombinant SHH, Smoothened Agonist) or with inhibitors of the pathway (Cyclopamine, HPI-4, GANT61) in the absence or presence of TGF-beta 1 (1-5 ng/ml) for 48h in serum-free medium. The expression of E-Cadherin, N-Cadherin, and fibronectin is evaluated by real-time PCR, Western blotting and immunocytochemistry. The migratory capacity of A549 is also measured in these conditions.Results. Inhibition of the pathway via SMO/GLI abolishes the effect of TGF-beta 1 on the migration of epithelial cells but do not influence the effect of TGF-beta 1 on cell differentiation. By contrast, the inhibition of the HH pathway in the primary cilium with HPI-4 prevents and reverts the effect of TGF-beta 1 on epithelial cell differentiation.Conclusions. Our results indicate that the primary cilium controls the effect of TGF-beta 1 on A549 cells in vitro.