Chiral lipidomics of monoepoxy and monohydroxy metabolites derived from long-chain polyunsaturated fatty acids[S]

Journal of Lipid Research

Mirjam Karber¹  Inci Dogan²  Michael Rothe²  Maximilian Blum³  Wolf-Hagen Schunck⁴ 

[1] Berlin Institute of Health (BIH), Berlin, Germany;Lipidomix GmbH, Berlin, Germany;Max Delbrueck Center for Molecular Medicine, Berlin, Germany;To whom correspondence should be addressed;

关键词: tandem mass spectrometry;    cytochrome P450;    eicosanoids;    lipoxygenase;    chiral high-performance liquid chromatography;    soluble epoxide hydrolase;   

DOI  :  

来源: DOAJ

【 摘 要 】

A chiral lipidomics approach was established for comprehensive profiling of regio- and stereoisomeric monoepoxy and monohydroxy metabolites of long-chain PUFAs as generated enzymatically by cytochromes P450 (CYPs), lipoxygenases (LOXs), and cyclooxygenases (COXs) and, in part, also unspecific oxidations. The method relies on reversed-phase chiral-LC coupled with ESI/MS/MS. Applications revealed partially opposing enantioselectivities of soluble and microsomal epoxide hydrolases (mEHs). Ablation of the soluble epoxide hydrolase (sEH) gene resulted in specific alterations in the enantiomeric composition of endogenous monoepoxy metabolites. For example, the (R,S)/(S,R)-ratio of circulating 14,15-EET changed from 2.1:1 in WT to 9.7:1 in the sEH-KO mice. Studies with liver microsomes suggested that CYP/mEH interactions play a primary role in determining the enantiomeric composition of monoepoxy metabolites during their generation and release from the ER. Analysis of human plasma showed significant enantiomeric excess with several monoepoxy metabolites. Monohydroxy metabolites were generally present as racemates; however, Ca2+-ionophore stimulation of whole blood samples resulted in enantioselective increases of LOX-derived metabolites (12S-HETE and 17S-hydroxydocosahexaenoic acid) and COX-derived metabolites (11R-HETE). Our chiral approach may provide novel opportunities for investigating the role of bioactive lipid mediators that generally exert their physiological functions in a highly regio- and stereospecific manner.

【 授权许可】

Unknown