Understanding the Dynamics of Pro-Fibrotic Biomarkers in Precision-Cut Lung Slices: Implications for Preclinical Studies

Pulmonary fibrosis (PF) is a chronic disease characterized by excessive deposition of matrix leading to stiffening of tissue, impaired lung function, and a significant decline of quality of life. The Wnt signaling pathway, known for its role in tissue development and regeneration, has also been implicated in PF. Our study evaluates the dynamics of pro-fibrotic biomarkers and mediators involved in PF using cultures of Precision-Cut Lung Slices (PCLS), assessing their utility in preclinical studies. PCLS were prepared from lung cancer or PF patients. Cytokines/proteins were measured by ELISA/MSD or immunohistochemistry (IHC) and gene expression profiles were analyzed by Next Generation Sequencing (NGS) or RTqPCR. We found a significant dysregulation in the expression of PF-associated aberrant epithelial genes Keratin-17 and 19 (KRT17; KRT19), the proliferative marker MKI67, and AT2 cell Surfactant protein C and D (SFTPC, SFTPD) in PF tissue as compared to healthy controls after 6h. KRT19, SFTPD, PDGFB, MMP9, and the Wnt target gene AXIN2 were significantly different between PF and non-PF PCLS after 24h. In PF tissue, AXIN2 decreased by 52% and SFTPC by 92%, and MKI67 increased by 47% and KRT19 by 17% after 72h, confirmed by IHC staining or MSD. Nintedanib treatment decreased SFTPD by up to 44% and MMP9 up to 64%, with limited effect on PDGFB after 48h of culture. Our study underscores the value of PCLS for unraveling the complex molecular landscape of PF and provides insights into the dynamics of pro-fibrotic markers, Wnt pathway activation, and Nintedanib treatment, highlighting the PCLS as an important approach to advance our understanding of PF pathogenesis.