Inhibition of soluble epoxide hydrolase protects against phosgene-induced lung injuries

总结

Summary Phosgene gas has been used as a terrorist weapon, in warfare and has injured many Americans in transportation or industrial accidents. Despite its devastating effects, no mechanism-based treatment has been developed. Soluble epoxide hydrolase (sEH) enzyme mediates the degradation of beneficial epoxyeicosatrienoic acids (EETs) and other fatty acid epoxides such as ω-3 docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) that mediate anti-inflammatory pathways and stimulate pro-resolving mechanisms. sEH enzyme levels and its downstream products have significantly increased in pulmonary disease models. Phosgene gas causes lipid peroxidation and membrane disruption that leads to alveolar-capillary barrier dysfunction. Soluble epoxide hydrolase inhibitors (sEHI) mitigated lipopolysaccharide (LPS), hyperoxia, and angiotensin II-induced acute lung injury (ALI). Further, sEHI also ameliorated chronic obstructive pulmonary disease (COPD), asthma, bleomycin-induced pulmonary fibrosis, and smoke-induced chronic lung injuries. In addition to pulmonary indications, sEHIs have shown beneficial therapeutic benefits in inflammatory diseases, destructive bone diseases, sepsis, cardiovascular diseases, neurodegenerative diseases, and pain. Some of the sEHI have been tested in clinical trials with encouraging outcomes and no potential side effects. While the therapeutic effects of sEHIs hold great promise as a broad-spectrum treatment candidate, these inhibitors have not yet been tested in pulmonary chemical injuries. In this application, we hypothesize that inhibiting soluble epoxide hydrolase ameliorates phosgene gas-induced lung injury, leading to decreased morbidity and improved recovery. Here, we propose to test the efficacy of three highly potent and selective sEHIs in mouse models of phosgene inhalation injury, with the goal to identify a lead therapeutic drug candidate as a future human medical countermeasure. The following aims are proposed: Aim 1: Assess the therapeutic effects of sEH inhibitors in a mouse model of phosgene gas-induced acute lung injury; Aim 2: Determine the pharmacokinetic profile of the most potent sEH inhibitor in naïve and phosgene gas-exposed mice; Aim 3: Assess the therapeutic efficacy of most potent sEH inhibitor in reducing mortality in a mouse model of phosgene gas-induced lung injury.