Characterization of acrolein-glycerophosphoethanolamine lipid adducts using electrospray mass spectrometry

Acrolein is a toxic, highly reactive alpha,beta-unsaturated aldehyde. In the current study, the products of acrolein after reaction with glycerophosphoethanolamine (GPEtn) lipids have been characterized using electrospray tandem mass spectrometry. The major product formed involves the addition of two acrolein molecules to the primary amine of GPEtn lipids and subsequent aldol condensation to form 1,2-diradyl- sn-glycero-3-phosphoethanol-(3-formyl-4-hydroxy)piperidine (FHP) lipids. Upon sodium borohydride reduction, 1,2-diradyl- sn-glycero-3-phosphoethanol-(3-hydroxymethyl-4-hydroxy)piperidine (HMHP) lipids and 1,2-diradyl- sn-glycero-3-phosphoethanol-(3-hydroxymethyl-3,4-dehydro)piperidine (HMDP) lipids were selectively detected using electrospray tandem mass spectrometry by employing precursors of m/ z 256.1 and 238.1 scans, respectively. HMHP lipid and HMDP lipid molecular species were detected upon treatment of HL-60 cells with concentrations of acrolein as low as 10 microM. While the biological implications of these acrolein GPEtn adducts have yet to be established, these structural characterization studies reported herein reveal the facile formation of acrolein GPEtn lipid adducts in vitro, which could influence subsequent biochemical events within the cell.