LC-MS and LC-MS/MS-based targeted lipid and oxylipin profiling of BALF in acute lung injury mice

Background Endotoxin-induced acute lung injury (ALI) is characterized by alveolar-capillary barrier disruption, pulmonary edema, and excessive inflammatory responses, leading to high morbidity and mortality in critically ill patients. Lipids and oxylipins are key regulators of inflammation and have been implicated in pulmonary disease. Therefore, comprehensive profiling of lipid and oxylipin alterations may reveal potential candidate biomarkers for endotoxin-induced lung injury. Methods In our study, targeted lipid and oxylipin profiling was performed on bronchoalveolar lavage fluid (BALF) collected from six mice with lipopolysaccharide (LPS)-induced ALI and six healthy control mice. Differences in lipid and oxylipin compositions between the two groups were systematically analyzed to characterize metabolic alterations associated with ALI. Results A total of 653 lipid species were identified, of which 183 differed significantly between ALI mice compared with controls, with elevated levels of 179 species and reduced levels of 4 species. Among the 89 oxylipin-related analytes measured, 26 oxylipin species showed significantly altered relative abundance, including 21 with increased and 5 decreased. Exploratory correlation analysis revealed class-associated clustering and inverse associations among lipid and oxylipin-related analytes. Conclusion Our findings provide a comprehensive characterization of lipid and oxylipin alterations in LPS-induced ALI and identify specific lipid and oxylipin species as potential candidates for further biomarker validation and mechanistic investigations.