Proteomics, Redox Proteomics, and Metabolomics Profiling of Phosgene-induced Lung Injury in a Murine Model
Clair, GCD; Day, N; Daly, JM; Ushakumary, MG; Jordt, SE; Achanta, S; Lin, V
Published in: American Journal of Respiratory and Critical Care Medicine
Background: Phosgene is an industrial chemical known to cause severe lung injury following acute exposure. Understanding the molecular mechanisms underlying phosgene-induced acute lung injury (ALI) is critical for developing effective biomarkers and medical countermeasures. Despite phosgene's known risks as a potential pulmonary hazard since World War I, the detailed pathophysiological events within the complex lung environment remain poorly understood. Methods: Using a murine model, we exposed male and female mice to phosgene (7.5 ppm) or filtered air. Lungs were harvested at 24 hours post-exposure and subjected to comprehensive proteomics, lipidomics, and metabolomics profiling using established mass spectrometry methods. Results: Proteome profiling achieved a depth of 7,906 quantifiable proteins. Metabolomics identified 456 unique metabolites, and redox proteomics profiled thousands of cysteine oxidation events. Principal component analysis of proteome data revealed significant segregation between phosgene and air-exposed lungs, with 3,761 proteins modulated (828 less abundant, 2,933 more abundant) in phosgene-exposed samples. Myofibroblast markers increased, while alveolar fibroblast 1, pericyte, alveolar capillary, and alveolar epithelial markers decreased, indicating extensive parenchymal damage. Immune cell markers, particularly of mast cells and neutrophils, increased. Pathway analysis highlighted enrichment in fibrinolysis and complement activation pathways. Metabolomics showed distinct profiles with significant reductions in osmoprotective and antioxidant metabolites, and increases in free fatty acids, carnitine esters, and lyso-phosphatidylcholines. Redox proteomics revealed a high degree of oxidative stress with over 9,000 sites showing increased cysteine oxidation. Conclusions: Our multi-omics approach provides detailed insights into the molecular and cellular changes induced by phosgene exposure. Identified shifts in protein abundance, metabolite levels, and extensive redox modifications highlight the severe impact of phosgene on lung tissue. While these findings offer potential targets for therapeutic intervention to mitigate phosgene-induced lung injury, additional studies are warranted to elucidate the fate of these findings in the extended observation mouse models.
