Dissertation/Thesis Abstract

Oxidative Stress and Apolipoprotein E3 in Brain Endothelial Cells
by Cruz, Siobanth, M.S., California State University, Long Beach, 2018, 95; 10978104
Abstract (Summary)

Apolipoprotein E3 (apoE3) plays a role in the metabolism of lipoproteins and lowers plasma lipid levels by serving as a ligand for the low density lipoprotein receptor (LDLr) family of proteins and by promoting macrophage cholesterol efflux. The current study examines the effect of acrolein modification on the structure and function of apoE3. Acrolein modification was confirmed in immunoblots by reactivity with acrolein-lysine-specific antibody and by the presence of oligomeric species due to crosslinking. Mass spectrometry revealed modification of K75 (propanal adduct) and K157 (MP-lysine). Circular dichroism spectroscopy showed no major change in overall secondary structure compared to unmodified apoE3. Acrolein-modified apoE3 showed loss of binding to soluble LDLr; however, incubation with mouse endothelioma bEnd.3 cells showed that it was internalized. Incubation with excess LDL did not abolish cellular uptake of acrolein-modified apoE3, suggesting alternative mechanism(s) not involving LDLr. Incubation with anti-CD36 antibody did not show a decrease in internalization while incubation with anti-LOX1 showed partial internalization. However, incubation with anti-SRB1 antibody abolished internalization of acrolein-modified apoE3. Taken together, our studies suggest that acrolein modification of apoE3 at lysine residues involved directly or indirectly with lipoprotein receptor interaction may impair its role in regulating plasma cholesterol homeostasis and eventually lead to lipid metabolic disorders.

Indexing (document details)
Advisor: Narayanaswami, Vasanthy
Commitee: Bhandari, Deepali, Fraser, Deborah
School: California State University, Long Beach
Department: Chemistry and Biochemistry
School Location: United States -- California
Source: MAI 58/04M(E), Masters Abstracts International
Source Type: DISSERTATION
Subjects: Biochemistry
Keywords: Acrolein, Apolipoprotein E3, Oxidative stress, Scavenger receptors
Publication Number: 10978104
ISBN: 9780438893498
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