GPCR-induced YAP activation sensitizes fibroblasts to profibrotic effects of TGFβ1

Fibrosis is an uncontrolled wound healing process resulting from tissue injury, inflammation and fibroblast activation, finally leading to accumulation of extracellular matrix (ECM) components in tissues and to organ failure. The underlying mechanisms of fibrosis have been intensely studied and it has become clear that multiple pathways and their crosstalk regulate fibrotic diseases with a few central players, including TGFβ1. Recently, YAP and TAZ were implicated in fibrosis as one of the essential components of its pathogenesis. YAP/TAZ are known to crosstalk with the TGFβ pathway in the nucleus and regulate its activity on transcriptional level by binding to Smad2/3/4 complexes. We hypothesized that factors, such as GPCR ligands which regulate YAP/TAZ, might modulate the profibrotic responses to TGFβ1. We performed gene expression microarray in NHDF treated with TGFβ1, LPA, the combination of TGFβ1/LPA or vehicle. The aim was to have a broader look at transcriptional signatures induced by the individual treatments and in the combination of TGFβ1 and LPA. Comparison of primary human skin fibroblasts stimulated with TGFβ1, LPA and the combination of TGFβ1 plus LPA; 4 replicates per group