Abstract
Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and fatal interstitial lung disease. Therapeutic options for IPF remain limited. Nintedanib, a tyrosine kinase inhibitor approved for IPF treatment, is known to inhibit fibroblasts proliferation, migration and transformation to myofibroblasts. However, how nintedanib changes gene regulations in IPF has never been systematically investigated. We conducted a next-generation sequencing and bioinformatics study to evaluate the changes of mRNA and miRNA profiles in IPF fibroblasts treated with 2 µM and 4 µM nintedanib, compared to those without treatment. We identified 157 upregulated and 151 downregulated genes and used STRING and DAVID databases for analysis of protein⁻protein interactions, biological pathways, and molecular functions. We found strong protein⁻protein interactions within these dysregulated genes, mostly involved in the pathways of cell cycle and mitotic cell cycle. We also discovered 13 potential miRNA⁻mRNA interactions associated with nintedanib treatment. After validation using miRDB, TargetScan, and RT-qPCR, we identified 4 downregulated genes (DDX11, E2F1, NPTX1, and PLXNA4) which might be repressed by the upregulated hsa-miR-486-3p. According to the proposed functions of DDX11, E2F1, and PLXNA4 reported in previous studies, these gene expression changes together might contribute to decreased proliferation of fibroblasts and decreased angiogenesis in the microenvironment of IPF. Our findings need further studies to confirm.