Linked Life Data

11714848

Source:http://linkedlifedata.com/resource/pubmed/id/11714848

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2001-11-20
pubmed:abstractText
Estrogen replacement therapies, such as conjugated equine estrogen (CEE, Premarin), reduce the risk of coronary heart disease among postmenopausal women. In the present study, a HepG2 stable cell line (HepG2/S) that harbors a luciferase reporter gene cassette with the human apolipoprotein A-I (apoA-I) promoter region was used to examine the activity of CEE components in modulating human apoA-I promoter activity. A number of estrogens modulated apoA-I promoter activity, with equilenin (Eqn) being the most potent. Eqn produced a 3-fold increase in apoA-I promoter activity and a similar increase in apoA-I mRNA without affecting its degradation rate. Nuclear runoff assays indicated that the transcription rate of the apoA-I gene was increased 2.5-fold in Eqn-treated cells. When HepG2/S cells were exposed to Eqn, apoA-I protein secretion increased by 80%, whereas the level of secreted apoA-II remained unchanged. Transient transfection studies with human apoA-I promoter constructs derived from pGL3-luciferase reporter plasmid were used to identify the cis-acting element involved in Eqn-mediated induction. The results demonstrated that the apoA-I electrophile/antioxidant response element (EpRE/ARE) might be responsible for the increase in apoA-I promoter activity by Eqn. Cotransfection experiments using estrogen receptor (ERalpha and/or ERbeta) expression vectors have indicated that neither receptor can potentiate the Eqn-mediated induction of apoA-I promoter activity. In addition, mobility shift analysis using antibody against either ERalpha or ERbeta cannot detect the presence of these receptors in the DNA-protein complex. The data indicate that Eqn can induce the promoter activity of the human apoA-I gene, leading to an increase in apoA-I mRNA levels and apoA-I protein secretion through an ER-independent pathway involving apoA-I EpRE/ARE.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-2275
pubmed:author
pubmed:issnType
Print
pubmed:volume
42
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1789-800
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:11714848-Animals, pubmed-meshheading:11714848-Apolipoprotein A-I, pubmed-meshheading:11714848-Apolipoproteins, pubmed-meshheading:11714848-Carcinoma, Hepatocellular, pubmed-meshheading:11714848-Equilenin, pubmed-meshheading:11714848-Estrogen Antagonists, pubmed-meshheading:11714848-Estrogens, pubmed-meshheading:11714848-Gene Expression Regulation, pubmed-meshheading:11714848-Horses, pubmed-meshheading:11714848-Humans, pubmed-meshheading:11714848-Kinetics, pubmed-meshheading:11714848-Liver Neoplasms, pubmed-meshheading:11714848-Luciferases, pubmed-meshheading:11714848-Promoter Regions, Genetic, pubmed-meshheading:11714848-RNA, Messenger, pubmed-meshheading:11714848-Receptors, Estrogen, pubmed-meshheading:11714848-Response Elements, pubmed-meshheading:11714848-Transfection, pubmed-meshheading:11714848-Tumor Cells, Cultured
pubmed:year
2001
pubmed:articleTitle
Regulation of human apolipoprotein A-I gene expression by equine estrogens.
pubmed:affiliation
Department of Biochemistry, Queen's University, Kingston, Ontario, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't