Regulation by long-chain fatty acids of the expression of cholesteryl ester transfer protein in HepG2 cells.
Cholesteryl ester transfer protein (CETP) is an important determinant of lipoprotein function, especially high density lipoprotein (HDL) metabolism, and contributes to the regulation of plasma HDL levels. Since saturated and polyunsaturated fatty acids (FA) appear to influence the CETP activity differently, we decided to investigate the effects of FA on the expression of CETP mRNA in HepG2 cells using an RNA blot hybridization analysis. Long-chain FA (>18 carbons) at a 0.5 mM concentration were added to the medium and incubated with cells for 48 h at 37 degrees C under 5% CO2. After treatment with 0.5 mM arachidonic (AA), eicosapentaenoic (EPA), and docosahexaenoic acid (DHA), the levels of CETP mRNA were less than 50% of the control levels (AA, P = 0.0005; EPA, P < 0.01; DHA, P < 0.0001), with a corresponding significant decrease in the CETP mass. These results suggest that FA regulate the gene expression of CETP in HepG2 and this effect is dependent upon the degree of unsaturation of the acyl carbon chain in FA.
Hirano
R
R
Internal Medicine I, National Defense Medical College, Saitama, Japan.
Igarashi
O
O
Kondo
K
K
Itakura
H
H
Matsumoto
A
A
D016718:Arachidonic Acid / Q000494:pharmacology; D006528:Carcinoma, Hepatocellular / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics*; D053480:Cholesterol Ester Transfer Proteins; D004281:Docosahexaenoic Acids / Q000494:pharmacology; D015118:Eicosapentaenoic Acid / Q000494:pharmacology; D005227:Fatty Acids / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D006023:Glycoproteins; D006801:Humans; D012333:RNA, Messenger / Q000032:analysis; D014407:Tumor Cells, Cultured
C506642:CETP protein, human; D002352:Carrier Proteins; D053480:Cholesterol Ester Transfer Proteins; D005227:Fatty Acids; D006023:Glycoproteins; D012333:RNA, Messenger; D004281:Docosahexaenoic Acids; D016718:Arachidonic Acid; D015118:Eicosapentaenoic Acid