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ChREBP, but not LXRs, is required for the induction of glucose-regulated genes in mouse liver.

ABSTRACT: The transcription factor carbohydrate-responsive element-binding protein (ChREBP) has emerged as a central regulator of lipid synthesis in liver because it is required for glucose-induced expression of the glycolytic enzyme liver-pyruvate kinase (L-PK) and acts in synergy with SREBP to induce lipogenic genes such as acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS). Liver X receptors (LXRs) are also important regulators of the lipogenic pathway, and the recent finding that ChREBP is a direct target of LXRs and that glucose itself can bind and activate LXRs prompted us to study the role of LXRs in the induction of glucose-regulated genes in liver. Using an LXR agonist in wild-type mice, we found that LXR stimulation did not promote ChREBP phosphorylation or nuclear localization in the absence of an increased intrahepatic glucose flux. Furthermore, the induction of ChREBP, L-PK, and ACC by glucose or high-carbohydrate diet was similar in LXRalpha/beta knockout compared with wild-type mice, suggesting that the activation of these genes by glucose occurs by an LXR-independent mechanism. We used fluorescence resonance energy transfer analysis to demonstrate that glucose failed to promote the interaction of LXRalpha/beta with specific cofactors. Finally, siRNA silencing of ChREBP in LXRalpha/beta knockout hepatocytes abrogated glucose-induced expression of L-PK and ACC, further demonstrating the central role of ChREBP in glucose signaling. Taken together, our results demonstrate that glucose is required for ChREBP functional activity and that LXRs are not necessary for the induction of glucose-regulated genes in liver.

SUBMITTER: Denechaud PD

PROVIDER: S-EPMC2248330 | biostudies-literature |

REPOSITORIES: biostudies-literature

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c-Myc is required for the CHREBP-dependent activation of glucose-responsive genes.

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HGFAC is a ChREBP Regulated Hepatokine that Enhances Glucose and Lipid Homeostasis

Project description:This SuperSeries is composed of the SubSeries listed below.

2022-11-15 | GSE217983 | GEO

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ChREBP mediates glucose-stimulated pancreatic β-cell proliferation.

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| S-EPMC3402328 | biostudies-literature

HGFAC is a ChREBP Regulated Hepatokine that Enhances Glucose and Lipid Homeostasis [ChIP-Seq]

Project description:Carbohydrate Responsive Element-Binding Protein (ChREBP) is a carbohydrate sensing transcription factor that regulates both adaptive and maladaptive genomic responses in coordination of systemic fuel homeostasis. Genetic variants in the ChREBP locus associate with diverse metabolic traits in humans, including circulating lipids. To identify novel ChREBP-regulated hepatokines that contribute to its systemic metabolic effects, we integrated ChREBP ChIP-seq analysis in mouse liver with human genetic and genomic data for lipid traits and identified Hepatocyte Growth Factor Activator (HGFAC) as a promising ChREBP-regulated candidate in mice and humans. HGFAC is a protease that activates the pleiotropic hormone Hepatocyte Growth Factor (HGF). We demonstrate that HGFAC KO mice have phenotypes concordant with putative loss-of-function variants in human HGFAC. Moreover, in gain- and loss-of-function genetic mouse models, we demonstrate that HGFAC enhances lipid and glucose homeostasis, which may be mediated in part through actions to activate hepatic PPARγ activity. Together, our studies show that ChREBP mediates an adaptive response to overnutrition via activation of HGFAC in the liver to preserve glucose and lipid homeostasis.

2022-11-15 | GSE217937 | GEO

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