Elevated integrin Α5 expression in idiopathic pulmonary fibrosis (IPF) derived fibroblasts is linked to paracrine TNF-α signaling

Abstract

Rationale: IPF is a progressive lung disease with a poor prognosis. Inflammatory cytokines play a significant role in IPF pathology. However, the fibroblast itself is also believed to be the primary effector in IPF. We hypothesized that the fibroblasts themselves secrete pro-inflammatory cytokines that could propagate IPF by affecting normal neighboring cells. Thus, we explored the effects of IPF fibroblast derived media on normal fibroblast characteristics. Methods: Primary IPF/ normal tissue derived fibroblast culture supernatants were collected (IPF/ N-UF, respectively) and added to normal fibroblasts. Cell death (FACS), cell number, viability (WST-1), migration (scratch test) and cell detachment (crystal violet and fibronectin adhesion assay) were tested. 10 inflammatory cytokines were measured by ELISA-based quantitative array. Integrin α5 (ITGA5), pIκBα, p/total STAT3 levels were measured by western blot/ IHC. TNF-α involvement was confirmed using Infliximab ®, anti-TNF-α mAb. Results: The IPF-UF facilitated fibroblast detachment and reduced cell migration (p Moreover, IPF fibroblasts express higher ITGA5 than the normal cells (44%↑, p Conclusion: IPF fibroblast secreted TNF-α modifies neighboring fibroblast cell behavior.