Dexamethasone increases apolipoprotein A-I concentrations in medium and apolipoprotein A-I mRNA abundance from Hep G2 cells. Metabolism 1992 Oct;41(10):1075-80
Date
10/11/1992Pubmed ID
1328818DOI
10.1016/0026-0495(92)90288-lScopus ID
2-s2.0-0026657442 (requires institutional sign-in at Scopus site) 18 CitationsAbstract
Glucocorticoid hormones increase high-density lipoprotein (HDL) levels in vivo. However, there is little known about the mechanism by which glucocorticoids alter HDL metabolism. Hep G2 cells were incubated with dexamethasone to determine the effect of glucocorticoids on apolipoprotein (apo) A-I secretion. Dexamethasone increased apo A-I concentration in a dose-dependent fashion. After 24 hours, 5.5 x 10(-5) mol/L dexamethasone increased apo A-I accumulation in culture medium by 54%. Detectable increases in apo A-I concentration were noted in medium by 5 hours of incubation and persisted up to 48 hours. Cellular apo A-I mRNA concentration increased by 28% after incubation with dexamethasone for 24 hours. The increase in apo A-I mRNA concentration was detectable within 3 hours after incubation with dexamethasone. In contrast, incubation with dexamethasone decreased apo B concentration by 43% in culture medium, but it had no effect on cellular apo B mRNA concentrations. Dexamethasone had little effect on cholesterol and triglyceride accumulation in the medium. Incubation with albumin alone did not affect apo A-I concentration, but it decreased apo B concentration by 30% in the medium. Incubation with albumin and dexamethasone had no effect on apo A-I concentration in medium and had no additive effect on apo B concentration. These data suggest dexamethasone increases secretion of apo A-I by Hep G2 cells by increasing mRNA levels.
Author List
Varma VK, Smith TK, Sorci-Thomas M, Ettinger WH JrAuthor
Mary Sorci Thomas PhD Professor in the Medicine department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AlbuminsApolipoprotein A-I
Carcinoma, Hepatocellular
Cholesterol
Culture Media
Dexamethasone
Dose-Response Relationship, Drug
Humans
Lipoproteins
Liver Neoplasms
RNA, Messenger
Time Factors
Triglycerides
Tumor Cells, Cultured