Bleomycin-induced in vitro 3D spheroid model to emulate pulmonary fibrosis

Introduction: Pulmonary fibrosis (PF) is the end stage of several diffuse parenchymal lung diseases (DPLDs) finally leading to respiratory insufficiency. Repeated injury is caused by an interaction between genetic predisposition and several environmental agents. There is need novel invitro models to be studied each causative agents’ role in pathogenesis. Aims and Objectives: To develop an advanced humanized drug induced fibrosis in vitro model to be used in the pathogenesis of DPLDs. Methods: The lung multicellular spheroid formation (MSC) formed by co-culturing human bronchial epithelial cells (BEAS-2B) and human lung fibroblasts (CCD-34Lu) to mimic cellular interactions within the epithelial-interstitial tissue. PF associated biomarkers (e.g., collagen type I) and pathways (e.g.,Tgf-β/Smad) were investigated following the bleomycin (BLM) induction, along with drug-free control medium. The reliability of the model tested with FDA approved anti-fibrotic drugs, pirfenidone and nintedanip. Results: The increase in PF related biomarkers as well as the activated pathways were observed in BLM-induced model comparing the control group. The anti-fibrotic drugs showed suppressive effects on the related indicators. Conclusion: The PF model through the BLM induced MSC, successfully represents fibrotic environment of which drug- responsiveness was confirmed by anti-fibrotics. Acknowledgement: Ege University Scientific Research Fund (Grant number: FGA-2020-21686) and Presidency of the Republic of Turkey, Presidency of Strategy and Budget (Grant number: 2019K12-149080) are appreciated for their supports.