Assessment of Imatinib Anti-Remodeling Activity on a Human Precision Cut Lung Slices Model.

Recent studies have emphasized the critical role of alteration in cellular plasticity in the development of fibrotic disorders, particularly pulmonary fibrosis, prompting further investigation into molecular mechanisms and therapeutic approaches. In this context, Precision Cut Lung Slices (PCLSs) emerge as a valuable ex vivo research tool. The process of PCLSs generation preserves most features of the naïve lung tissue, such as its architecture and complex cellular composition. We previously stimulated normal lung PCLSs with two different stimuli (fibrotic cocktail, composed by platelet lysate and TGFβ, or neutrophil extracellular traps) and we observed a significant elevation of Epithelial-Mesenchymal Transition (EMT) markers from 24 h to 72 h of culture. The aim of our work was to exploit this PCLSs based ex vivo model of EMT, to evaluate the effect of imatinib, an old tyrosine kinase inhibitor with reported anti-remodeling activities in vitro and in animal models. Imatinib treatment significantly decreased α-SMA and collagen expression already starting from 24 h on stimulated PCLS. Imatinib showed a significant toxicity on unstimulated cells (3-fold increase in ACTA2 expression levels at 24 h, 1.5-fold increase in COL1A1 expression levels at 24 h, 2-fold increase in COL3A1 expression levels at 72 h). Further evaluations on specific cell lines pointed out that drug effects were mainly directed towards A549 and LFs. In conclusion, our model confirms the anti-remodeling activity of imatinib but suggests that its direct delivery to alveolar epithelial cells as recently attempted by inhalatory preparation of the drug might be associated with a non-negligible epithelial cell toxicity.