Modified sites and functional consequences of 4-oxo-2-nonenal adducts in HDL that are elevated in familial hypercholesterolemia.

May-Zhang LS, Yermalitsky V, Melchior JT, Morris J, Tallman KA, Borja MS, Pleasent T, Amarnath V, Song W, Yancey PG, Davidson WS, Linton MF, Davies SS
J Biol Chem. 2019 294 (50): 19022-19033

PMID: 31666337 · PMCID: PMC6916491 · DOI:10.1074/jbc.RA119.009424

The lipid aldehyde 4-oxo-2-nonenal (ONE) is a highly reactive protein crosslinker derived from peroxidation of n-6 polyunsaturated fatty acids and generated together with 4-hydroxynonenal (HNE). Lipid peroxidation product-mediated crosslinking of proteins in high-density lipoprotein (HDL) causes HDL dysfunction and contributes to atherogenesis. Although HNE is relatively well-studied, the role of ONE in atherosclerosis and in modifying HDL is unknown. Here, we found that individuals with familial hypercholesterolemia (FH) had significantly higher ONE-ketoamide (lysine) adducts in HDL (54.6 ± 33.8 pmol/mg) than healthy controls (15.3 ± 5.6 pmol/mg). ONE crosslinked apolipoprotein A-I (apoA-I) on HDL at a concentration of > 3 mol ONE per 10 mol apoA-I (0.3 eq), which was 100-fold lower than HNE, but comparable to the potent protein crosslinker isolevuglandin. ONE-modified HDL partially inhibited HDL's ability to protect against lipopolysaccharide (LPS)-induced tumor necrosis factor α (TNFα) and interleukin-1β (IL-1β) gene expression in murine macrophages. At 3 eq, ONE dramatically decreased apoA-I exchange from HDL, from ∼46.5 to ∼18.4% ( < 0.001). Surprisingly, ONE modification of HDL or apoA-I did not alter macrophage cholesterol efflux capacity. LC-MS/MS analysis revealed that Lys-12, Lys-23, Lys-96, and Lys-226 in apoA-I are modified by ONE ketoamide adducts. Compared with other dicarbonyl scavengers, pentylpyridoxamine (PPM) most efficaciously blocked ONE-induced protein crosslinking in HDL and also prevented HDL dysfunction in an model of inflammation. Our findings show that ONE-HDL adducts cause HDL dysfunction and are elevated in individuals with FH who have severe hypercholesterolemia.

© 2019 May-Zhang et al.

MeSH Terms (14)

Aldehydes Animals Apolipoprotein A-I Atherosclerosis Cells, Cultured Female Humans Hyperlipoproteinemia Type II Lipoproteins, HDL Lysine Male Mice Mice, Inbred C57BL Mice, Knockout

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