The combination of PDE4 and PDE5 inhibitors reduces YAP expression in IPF

Background: Pathological fibrosis is associated with repeated episodes of injury to alveolar epithelial cells of largely. Yes-associated protein (YAP) is prominently expressed in fibrotic lung. Roflumilast has demonstrated to exhibit anti-fibrosis effects, while PDE5 inhibitors (sildenafil) combinated with PDE4 inhibitors reduce fibrotic-effects secondary to TGFs1. Apparently, no studies of PDE4 and PDE5 inhibitors on YAP expression there are. Objectives: To study the effects from adding a sildenafil to Roflumilast N- oxide (RNO) on TGF-β/SMAD3/YAP pathway in IPF in vitro models. Methods: A549 cells were pre-incubated with therapeutical concentrations of RNO (2nM) and/or sildenafil (10nM) a…