Increased APOE glycosylation plays a key role in the atherogenicity of L5 low-density lipoprotein.
FASEB J
; 34(7): 9802-9813, 2020 07.
Article
em En
| MEDLINE
| ID: mdl-32501643
ABSTRACT
Low-density lipoprotein (LDL) is heterogeneous, composed of particles with variable atherogenicity. Electronegative L5 LDL exhibits atherogenic properties in vitro and in vivo, and its levels are elevated in patients with increased cardiovascular risk. Apolipoprotein E (APOE) content is increased in L5, but what role APOE plays in L5 function remains unclear. Here, we characterized the contributions of APOE posttranslational modification to L5's atherogenicity. Using two-dimensional electrophoresis and liquid chromatography-mass spectrometry, we studied APOE's posttranslational modification in L5 from human plasma. APOE structures with various glycan residues were predicted. Molecular docking and molecular dynamics simulation were performed to examine the functional changes of APOE resulting from glycosylation. We also examined the effects of L5 deglycosylation on endothelial cell apoptosis. The glycan sequence N-acetylgalactosamine, galactose, and sialic acid was consistently expressed on serine 94, threonine 194, and threonine 289 of APOE in L5 and was predicted to contribute to L5's negative surface charge and hydrophilicity. The electrostatic force between the negatively charged sialic acid-containing glycan residue of APOE and positively charged amino acids at the receptor-binding area suggested that glycosylation interferes with APOE's attraction to receptors, lipid-binding ability, and lipid transportation and metabolism functions. Importantly, L5 containing glycosylated APOE induced apoptosis in cultured endothelial cells through lectin-like oxidized LDL receptor-1 (LOX-1) signaling, and glycosylation removal from L5 attenuated L5-induced apoptosis. APOE glycosylation may contribute to the atherogenicity of L5 and be a useful biomarker for rapidly quantifying L5.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Apolipoproteínas E
/
Processamento de Proteína Pós-Traducional
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Síndrome Metabólica
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Células Endoteliais
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Aterosclerose
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Lipoproteínas LDL
Tipo de estudo:
Observational_studies
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Prognostic_studies
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Risk_factors_studies
Limite:
Humans
Idioma:
En
Revista:
FASEB J
Assunto da revista:
BIOLOGIA
/
FISIOLOGIA
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Estados Unidos