Development of an integrative approach to identify key molecular targets involved in bleomycin-induced pulmonary fibrosis in rats

Background: In the last 10 years, advanced molecular biology approaches and profiling techniques have greatly contributed to identify key regulatory molecules and pathways involved in several pathological states. IPF is a relatively poorly understood chronic and progressive disease and much of the information regarding the involved etiopathogenetic mechanisms was generated in the rodent bleomycin (BLM) model. A comprehensive multidisciplinary approach is proposed here to study molecular alterations in the lungs of BLM-treated rats and to improve the predictive nature of this model. Aims and objectives: We established proteomic and genomic survey approaches to monitor molecular changes induced by BLM in the rat airways and the therapeutic effect by Nintedanib. Methods: Male SD rats were intratracheally injected with a single administration of BLM (4U/Kg). Nintedanib (100 mg/kg, oral) was administered once daily for three weeks starting 7 days after BLM administration. Proteomic and gene expression analysis (Real Time PCR) were assessed in BALFs and lung homogenates. Levels of some targeted proteins were also monitored by ELISA specific assays. Results and Conclusions: The results highlight the peculiar features of BALFs and lung homogenates for the comprehensive molecular profiling of the rat BLM model. Investigation of a set of signalling transduction pathways altered in the BLM model and affected by Nintedanib is disclosed. Perspectives on targeted monitoring of novel markers of lung fibrosis are also discussed for a better understanding of the molecular pathogenesis of IPF and the response to therapy. VP and BP equally contributed.