Differential effects of Nintedanib and SB525334 in primary human cell-based assays of lungfibrosis

Background: Extensive studies have suggested epithelial-mesenchymal transition (EMT) and fibroblast-myofibroblast transformation (FMT) as major drivers of fibrosis. Both EMT and FMT are strongly regulated by TGFβ1. Objectives. The aim of this study was to assess a specific transcriptional analysis of a selected panel of genes involved in fibrogenesis by profiling TGFβ-stimulated human lung fibroblasts (HLFs) and human bronchial epithelial cells (HBECs) derived from IPF patients and healthy donors. Moreover, the effects of Nintedanib and the ALK5 inhibitor, SB525334, were evaluated. Methods: Cultured primary HLFs and HBECs were stimulated with TGF-β1 (1.25 and 5 ng/ml, respectively). IPF-derived cells were exposed to Nintedanib (3 µM) and SB525334 (1 µM). RNA was extracted and subsequently reverse transcribed and amplified. RT2 Profiler™ PCR Arrays Human Fibrosis (Qiagen) were used to gene expression analysis. Results: Approximately half of the assessed genes were endowed with a differential expression (≥1.5 fold) between non-stimulated IPF and control HLFs (e.g. GREM1, HGF) and HBECs (e.g. ITGB3, ENG). The above expression pattern was further modified when TGF-β1 was applied to IPF and control cells. Both Nintedanib and SB525334 mainly induced a significant effect on TGFβ1-induced differential expression of genes related to extracellular matrix remodelling (e.g. COL1A1 and COL3A1). Conclusions: Our study revealed a basal differential expression of a selected panel of genes among control and IPF cells. Furthermore, the subsequent validation step with Nintedanib may provide insights on new targets endowed with a potential anti-fibrotic effect.