Discovery and characterization of inflammation-induced electrophilic fatty acid derivatives

摘要: Electrophilic lipids are emerging as critical mediators of anti-inflammatory signaling pathways, although many biologically relevant electrophiles may still remain unknown. Nitro derivatives (NO2-FA) and a,â-unsaturated carbonyl unsaturated fatty acids naturally occurring electrophilic products redox reactions, can modulate a variety cellular processes including the transcriptional activity peroxisome proliferator-activated receptor-a (PPARa). PPARa binds diverse ligands to regulate expression genes involved in metabolism inflammation. Activators include anti-hyperglycemic drugs such thiazolidinediones (TZDs) intermediates lipid oxidation that bind with very low affinity. Recently TZDs have raised concern after being linked increased risk peripheral edema, weight gain, adverse cardiovascular events. In contrast, NO2-FA act partial agonists at nM concentrations covalently via Michael addition. show selective modulator characteristics by inducing coregulator protein interactions distinctively different from those induced TZD Rosiglitazone. further exploring lipidome, new subclass has been revealed. Using recently developed â-mercaptoethanol (BME) alkylation reaction, followed HPLC-MS/MS-based screening, we report six novel acid (EFADs) specifically formed during macrophage activation (RAW264.7 THP-1 cell lines primary macrophages treated IFNa LPS). The major EFADs oxo-derivatives omega-3 confirmed culture vitro studies MS/MS structural analysis. isomers two were identified 13- 17-keto docosapentaenoic (DPA) docosahexaenoic (DHA). Purified cyclooxygenase-2 (COX-2) product profiles treatment activated COX-2 inhibitors EFAD synthesis be catalyzed inducible COX-2, hydroxy-dehydrogenase activity. production was 2.5 fold acetylsalicylic (ASA; aspirin). Internal standard-based quantification showed highly abundant macrophages, reaching intracellular high 350 nM. Importantly, form reversibly reactive covalent adducts both proteins small molecule thiols supporting potential for post-translational modification-mediated signaling. Furthermore, synthetic EFAD-1 -2 (17-oxo-DHA 17-oxo-DPA, respectively) PPARa, activate Nrf2 (nuclear factor-erythroid 2-related factor 2)-dependent gene expression, inhibit pro-inflammatory cytokine iNOS LPS-activated RAW264.7 cells macrophages. conclusion, it demonstrated upon generate derived molecules autocrine mediators.