| Phosphatidylethanoamines (PEs) have different properties than their choline analogues and oxidatively truncated PEs have not been studied due to the unavailability of samples. PEs are essential components of membranes, which lose their functions when the PEs are depleted and regain it when the PE content is restored. Despite the fact that there is evidence of biological properties of PEs, it has been suggested that a choline headgroup is of critical importance for recognition of oxidized phospholipids by the scavenger receptors of macrophages. Studies reported herein show that like oxidatively truncated phosphatidylcholines, oxidized phosphatidylethanolamines (oxPEs) are recognized by CD36 phopholipid scavenger receptor, and that they have other biological properties which they share with their phosphatidylcholine analogs, such as stimulation of endothelial cells to bind to monocytes, or inhibition of lipopolysaccharide-induced expression of E-selectin or synthesis of interleukin 8. To assess these properties of oxPEs, as well as to demonstrate and quantify their formation from the parent polyunsaturated fatty acid phospholipids we devised efficient chemical syntheses of these natural products. The yields of formation of these oxPEs from the oxidation of polyunsaturated fatty acyl-PE (PUFA-PEs) were determined and six were identified and quantified in rat retina by LC/ESI-MS/MS. To provide an immunological tool for the detection of lipid oxidation-induced protein modification, in particular, of 4-hydroxyhexenal-derived ethylpyrrole modified proteins, a polyclonal antibody was produced that recognizes the ethylpyrrole epitope. |
