Coordinated control of cholesterol catabolism to bile acids and of gluconeogenesis via a novel mechanism of transcription regulation linked to the fasted-to-fed cycle.

Details

Serval ID
serval:BIB_864E147F2EEE
Type
Article: article from journal or magazin.
Collection
Publications
Title
Coordinated control of cholesterol catabolism to bile acids and of gluconeogenesis via a novel mechanism of transcription regulation linked to the fasted-to-fed cycle.
Journal
The Journal of biological chemistry
Author(s)
De Fabiani E., Mitro N., Gilardi F., Caruso D., Galli G., Crestani M.
ISSN
0021-9258 (Print)
ISSN-L
0021-9258
Publication state
Published
Issued date
03/10/2003
Peer-reviewed
Oui
Volume
278
Number
40
Pages
39124-39132
Language
english
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Abstract
Bile acid metabolism plays an essential role in cholesterol homeostasis and is critical for the initiation of atherosclerotic disease. However, despite the recent advances, the molecular mechanisms whereby bile acids regulate gene transcription and cholesterol homeostasis in mammals still need further investigations. Here, we show that bile acids suppress transcription of the gene (CYP7A1) encoding cholesterol 7alpha-hydroxylase, the rate-limiting enzyme in bile acid biosynthesis, also through an unusual mechanism not involving the bile acid nuclear receptor, farnesoid X receptor. By performing cell-based reporter assays, protein/protein interaction, and chromatin immunoprecipitation assays, we demonstrate that bile acids impair the recruitment of peroxisome proliferator-activated receptor-gamma coactivator-1alpha and cAMP response element-binding protein-binding protein by hepatocyte nuclear factor-4alpha, a master regulator of CYP7A1. We also show for the first time that bile acids inhibit transcription of the gene (PEPCK) encoding phosphoenolpyruvate carboxykinase, the rate-limiting enzyme in gluconeogenesis, through the same farnesoid X receptor-independent mechanism. Chromatin immunoprecipitation assay revealed that bile acid-induced dissociation of coactivators from hepatocyte nuclear factor-4alpha decreased the recruitment of RNA polymerase II to the core promoter and downstream in the 3'-untranslated regions of these two genes, reflecting the reduction of gene transcription. Finally, we found that Cyp7a1 expression was stimulated in fasted mice in parallel to Pepck, whereas the same genes were repressed by bile acids. Collectively, these results reveal a novel regulatory mechanism that controls gene transcription in response to extracellular stimuli and argue that the transcription regulation by bile acids of genes central to cholesterol and glucose metabolism should be viewed dynamically in the context of the fasted-to-fed cycle.
Keywords
3' Untranslated Regions, Animals, Basic Helix-Loop-Helix Leucine Zipper Transcription Factors, Bile Acids and Salts/metabolism, Blotting, Western, Cell Line, Cholesterol/metabolism, Cholesterol 7-alpha-Hydroxylase/genetics, Cholesterol 7-alpha-Hydroxylase/metabolism, Chromatin/metabolism, DNA-Binding Proteins/metabolism, Down-Regulation, Gene Expression Regulation, Genes, Reporter, Genetic Vectors, Gluconeogenesis, Glutathione Peroxidase, Hepatocyte Nuclear Factor 4, Humans, Ligands, Male, Mice, Mice, Inbred C57BL, Models, Biological, Phosphoproteins/metabolism, Plasmids/metabolism, Precipitin Tests, Promoter Regions, Genetic, Protein Structure, Tertiary, Proteins/metabolism, RNA Polymerase II/metabolism, RNA, Messenger/metabolism, Receptors, Cytoplasmic and Nuclear, Reverse Transcriptase Polymerase Chain Reaction, Transcription Factors/metabolism, Transcription, Genetic, Transfection
Pubmed
Web of science
Open Access
Yes
Create date
21/03/2019 11:29
Last modification date
20/02/2020 6:26
Usage data