Cholesterol effect on Apolipoprotein B secretion and binding of low-density lipoproteins hepatoma HepG2 Cells

• Published in: Biopolimery i kletka Vol. 5; no. 2; pp. 74 - 78
• Main Authors: Fuki, I. V., Preobrazhensky, S. N., Misharin, A. Yu, Bushmakina, N. G., Menshchikov, G. B., Repin, V. S.
• Format: Journal Article
• Language: English
• Published: Kiev Natsional'na Akademiya Nauk Ukrainy - National Academy of Sciences of Ukraine 20-03-1989
• Subjects: Apolipoprotein B; Apolipoproteins; Cell culture; Cholesterol; Dimyristoylphosphatidylcholine; Ethanol; Hepatoma; Lipoproteins; Liver cancer; Low density lipoprotein; Oleic acid; Secretion
• ISSN: 0233-7657; 1993-6842
• DOI: 10.7124/bc.0000AA

The effect of cholesterol, oleic acid and recombinant complexes containing apolipoprotein Al/dimyristoylphosphatidylcholine (apoAl/DMPC) on apolipoprotein B (apoB) secretion and uptake of 125I-labeled low-density lipoproteins (LDL) by cultured human hepatoma HepG2 cells was studied. Addition of different concentrations of exogenous cholesterol (as ethanol solution) to the cells increased apoB secretion and inhibited 1 25I-labelled LDL uptake in a dose-dependent manner. Similar effects were found when the cells were incubated with different concentrations of oleic acid, which enhanced the intracellular cholesterol content. The presence of complexes apoAl/DMPC in the culture medium, which decreased the cellular pool of cholesterol, resulted in the opposite effects: apoB secretion was inhibited, while the LDL-receptor activity was stimulated. Significant negative correlation (r = —0.92, p<0.001) was found between apoB secretion and LDL uptake. The obtained data suggest that cholesterol can induce cooperated changes in apoB secretion and LDL-rcceptor activity.