Document Detail


Role of intestinal sterol transporters Abcg5, Abcg8, and Npc1l1 in cholesterol absorption in mice: gender and age effects.
MedLine Citation:
PMID:  16179600     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Recent studies have indicated that intestinal cholesterol absorption is a multistep process, which is regulated by multiple genes at the enterocyte level. However, the molecular mechanisms whereby there are gender differences in intestinal cholesterol absorption efficiency and the efficiency of cholesterol absorption increases with age have not yet been fully understood. To explore whether aging increases cholesterol absorption via intestinal sterol transporters, we studied the higher cholesterol-absorbing C57L/J vs. the lower cholesterol-absorbing AKR/J mice at 8 (young adult), 36 (older adult), and 50 (aged) wk of age. To test the hypothesis that estrogen receptor (ER )alpha plays an important regulatory role in cholesterol absorption, we investigated the gonadectomized mice of both genders treated with 17beta-estradiol-releasing pellets at 0, 3, or 6 mug/day and antiestrogenic ICI 182,780 at 125 microg/day. We found that hepatic outputs of biliary cholesterol were significantly increased with age and in response to high levels of estrogen. Aging significantly enhances cholesterol absorption by suppressing expression of the jejunal and ileal sterol efflux transporters [ATP-binding cassette (Abc)g5 and Abcg8] and upregulating expression of the putative duodenal and jejunal sterol influx transporter Npc1l1. Estrogen significantly augmented cholesterol absorption mostly due to an upregulated expression of intestinal Npc1l1, Abcg5, and Abcg8 via the intestinal ERalpha pathway, which can be fully abolished by the antagonist. We conclude that ERalpha activated by estrogen and aging enhances cholesterol absorption by increasing biliary lipid output and mediating intestinal sterol transporters favoring influx of intraluminal cholesterol molecules across the apical membrane of the enterocyte.
Authors:
Li-Ping Duan; Helen H Wang; Akira Ohashi; David Q-H Wang
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2005-09-22
Journal Detail:
Title:  American journal of physiology. Gastrointestinal and liver physiology     Volume:  290     ISSN:  0193-1857     ISO Abbreviation:  Am. J. Physiol. Gastrointest. Liver Physiol.     Publication Date:  2006 Feb 
Date Detail:
Created Date:  2006-01-12     Completed Date:  2006-03-02     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  100901227     Medline TA:  Am J Physiol Gastrointest Liver Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  G269-76     Citation Subset:  IM    
Affiliation:
Gastroenterology Division, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Ave., DA 601, Boston, MA 02215, USA.
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MeSH Terms
Descriptor/Qualifier:
ATP-Binding Cassette Transporters / genetics,  physiology*
Aging / physiology*
Animals
Cholesterol, Dietary / pharmacokinetics*
Diet
Estrogen Antagonists / pharmacology
Estrogens / physiology
Gastrointestinal Transit / physiology
Intestinal Absorption / physiology*
Intestine, Small / metabolism
Lipoproteins / genetics,  physiology*
Membrane Transport Proteins / genetics,  physiology*
Mice
Mice, Inbred AKR
Mice, Inbred C57BL
Receptors, Estrogen / drug effects
Reverse Transcriptase Polymerase Chain Reaction
Sex Characteristics
Species Specificity
Grant Support
ID/Acronym/Agency:
DK-54012/DK/NIDDK NIH HHS
Chemical
Reg. No./Substance:
0/ABCG5 protein, mouse; 0/ABCG8 protein, mouse; 0/ATP-Binding Cassette Transporters; 0/Cholesterol, Dietary; 0/Estrogen Antagonists; 0/Estrogens; 0/Lipoproteins; 0/Membrane Transport Proteins; 0/Npc1l1 protein, mouse; 0/Receptors, Estrogen

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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