Linked Life Data

16481392

Source:http://linkedlifedata.com/resource/pubmed/id/16481392

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2006-5-22
pubmed:abstractText
Transactivation of the rat apical sodium-dependent bile acid transporter (ASBT; Slc10a2) by 1alpha,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] via the vitamin D receptor (VDR), was studied. Levels of ASBT protein and mRNA were low in the duodenum and high in the ileum, and both were induced by 1,25(OH)(2)D(3). The nuclear receptor protein, VDR, was present uniformly in the duodenum, jejunum, and ileum of the rat small intestine. The physiological relevance of ASBT induction by 1,25(OH)(2)D(3) was assessed by measuring absorption of cholylsarcosine, a non-metabolized synthetic bile acid analog, from duodenal or ileal closed loops of the perfused rat small intestine preparation. Absorption of cholylsarcosine was much greater from the ileal segment (28-fold that of the duodenum under control conditions) and was enhanced with 1,25(OH)(2)D(3) treatment. Transient transfection analysis of the rat ASBT promoter in Caco-2 cells revealed concentration-dependent enhancement of luciferase reporter activity after treatment with 1,25(OH)(2)D(3). The activation by 1,25(OH)(2)D(3) was abrogated after site-directed mutagenesis or deletion of the vitamin D response element (VDRE) in the ASBT promoter. Gel-shift mobility assays of nuclear extracts from rat ileum showed that both rat retinoid X receptor and VDR were bound to the VDRE. The results indicate that rat ASBT gene expression is activated by 1,25(OH)(2)D(3) by specific binding to the VDRE and that such activation enhances ileal bile acid transport. Human ABST mRNA and promoter activity were also increased in Caco-2 cells treated with 1,25(OH)(2)D(3), suggesting a physiological role of VDR in human ileal bile acid homeostasis.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0026-895X
pubmed:author
pubmed:issnType
Print
pubmed:volume
69
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1913-23
pubmed:dateRevised
2010-12-3
pubmed:meshHeading
pubmed-meshheading:16481392-Animals, pubmed-meshheading:16481392-Bile Acids and Salts, pubmed-meshheading:16481392-Biological Transport, pubmed-meshheading:16481392-Caco-2 Cells, pubmed-meshheading:16481392-Calcitriol, pubmed-meshheading:16481392-Cholic Acids, pubmed-meshheading:16481392-Erythrocytes, pubmed-meshheading:16481392-Gene Expression, pubmed-meshheading:16481392-Humans, pubmed-meshheading:16481392-Intestine, Small, pubmed-meshheading:16481392-Mutation, pubmed-meshheading:16481392-Organic Anion Transporters, Sodium-Dependent, pubmed-meshheading:16481392-Perfusion, pubmed-meshheading:16481392-Promoter Regions, Genetic, pubmed-meshheading:16481392-RNA, Messenger, pubmed-meshheading:16481392-Rats, pubmed-meshheading:16481392-Receptors, Calcitriol, pubmed-meshheading:16481392-Retinoid X Receptors, pubmed-meshheading:16481392-Sarcosine, pubmed-meshheading:16481392-Sequence Deletion, pubmed-meshheading:16481392-Symporters, pubmed-meshheading:16481392-Transcriptional Activation, pubmed-meshheading:16481392-Vitamin D Response Element
pubmed:year
2006
pubmed:articleTitle
Transactivation of rat apical sodium-dependent bile acid transporter and increased bile acid transport by 1alpha,25-dihydroxyvitamin D3 via the vitamin D receptor.
pubmed:affiliation
Faculty of Pharmacy, University of Toronto, 19 Russell Street, Toronto, Ontario M5S 2S2, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural