Mapping the metabolomic and lipidomic changes in the Bleomycin model of pulmonary fibrosis in young and aged mice.

Alterations in metabolic pathways were recently recognized as potential underlying drivers of idiopathic pulmonary fibrosis (IPF), translating into novel therapeutic targets. However, knowledge of metabolic and lipid regulation in fibrotic lungs is limited. To comprehensively characterize metabolic perturbations in the Bleomycin mouse model of IPF we analyzed the metabolome and lipidome by mass spectrometry. We identified increased tissue turnover and repair, evident by enhanced breakdown of proteins, nucleic acids, lipids and ECM turnover. Energy production was upregulated, including glycolysis, tricarboxylic acid (TCA) cycle, glutaminolysis, lactate production and increased fatty acid oxidation. Higher eicosanoid synthesis indicated inflammatory processes. Since the risk of IPF increases with age, we investigated how age influences metabolomic and lipidomic changes in the Bleomycin-induced pulmonary fibrosis model. Surprisingly, except cytidine, we did not detect any significantly differential metabolites or lipids between old and young Bleomycin-treated lungs. Together, we identified metabolomic and lipidomic changes in fibrosis that reflect higher energy demand, proliferation, tissue remodeling, collagen deposition and inflammation that might serve for improving diagnostic and therapeutic options for fibrotic lung diseases in the future.