Analysis of HETEs in human whole blood by chiral UHPLC-ECAPCI/HRMS

J Lipid Res. 2018 Mar;59(3):564-575. doi: 10.1194/jlr.D081414. Epub 2018 Jan 4.

Abstract

The biosynthesis of eicosanoids occurs enzymatically via lipoxygenases, cyclooxygenases, and cytochrome P450, or through nonenzymatic free radical reactions. The enzymatic routes are highly enantiospecific. Chiral separation and high-sensitivity detection methods are required to differentiate and quantify enantioselective HETEs in complex biological fluids. We report here a targeted chiral lipidomics analysis of human blood using ultra-HPLC-electron capture (EC) atmospheric pressure chemical ionization/high-resolution MS. Monitoring the high-resolution ions formed by the fragmentation of pentafluorobenzyl derivatives of oxidized lipids during the dissociative EC, followed by in-trap fragmentation, increased sensitivity by an order of magnitude when compared with the unit resolution MS. The 12(S)-HETE, 12(S)-hydroxy-(5Z,8E,10E)-heptadecatrienoic acid [12(S)-HHT], and 15(S)-HETE were the major hydroxylated nonesterified chiral lipids in serum. Stimulation of whole blood with zymosan and lipopolysaccharide (LPS) resulted in stimulus- and time-dependent effects. An acute exposure to zymosan induced ∼80% of the chiral plasma lipids, including 12(S)-HHT, 5(S)-HETE, 15(R)-HETE, and 15(S)-HETE, while a maximum response to LPS was achieved after a long-term stimulation. The reported method allows for a rapid quantification with high sensitivity and specificity of enantiospecific responses to in vitro stimulation or coagulation of human blood.

Trial registration: ClinicalTrials.gov NCT02095288.

Keywords: chiral hydroxyeicosatetraenoic acids; coagulation; human blood; hydroxyeicosatetraenoic acids; plasma lipidomics; serum lipidomics; ultra-high-performance liquid chromatography-electron capture atmospheric pressure chemical ionization high-resolution mass spectrometry.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Atmospheric Pressure
  • Chromatography, High Pressure Liquid
  • Humans
  • Hydroxyeicosatetraenoic Acids / blood*
  • Hydroxyeicosatetraenoic Acids / chemistry
  • Mass Spectrometry
  • Molecular Structure

Substances

  • Hydroxyeicosatetraenoic Acids

Associated data

  • ClinicalTrials.gov/NCT02095288