ChREBP-mediated control of Them1 expression coordinates thermogenesis with glycolysis and lipogenesis
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PROVIDER: PRJNA1181773 | ENA |
REPOSITORIES: ENA
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Project description:Activation of thermogenic brown adipose tissue (BAT) and inducible beige adipose tissue (BeAT) is triggered by environmental or metabolic stimuli, including cold ambient temperatures and nutrient stress. Thioesterase superfamily member 1 (Them1), a long chain fatty acyl-CoA thioesterase that is enriched in BAT, suppresses acute cold-induced thermogenesis. Here, we demonstrate that Them1 expression was induced in BAT and BeAT by the carbohydrate response element binding protein (ChREBP) in response to chronic cold exposure or to the activation of the integrated stress response (ISR). Under either condition, Them1 suppressed energy expenditure. Consequently, mice lacking Them1 in BAT and BeAT exhibited resistance to obesity and glucose intolerance induced by feeding with a high-fat diet. During chronic cold exposure or ISR activation, Them1 accumulated in the nucleus, where it interacted with ChREBP and reduced the expression of its target genes, including those encoding enzymes that mediate glycolysis and de novo lipogenesis. These findings demonstrate that in response to chronic cold- or nutrient-induced stress, the induction of Them1 by ChREBP limits thermogenesis while coordinately reducing glucose utilization and lipid biosynthesis through its distinct activities in the cytoplasm and nucleus. Targeted inhibition of Them1 may represent a potential therapeutic approach to increase the activity of BAT and BeAT to enhance energy expenditure in the management of obesity-associated metabolic disorders.
2025-02-19 | GSE280981 | GEO
Project description:Biallelic inactivating mutations of the transcription factor 1 gene (TCF1), encoding hepatocyte nuclear factor 1a (HNF1a), were identified in 50% of hepatocellular adenomas (HCA) phenotypically characterized by a striking steatosis. To understand the molecular basis of this aberrant lipid storage, we performed a microarray transcriptome analysis validated by quantitative RT-PCR, western-blotting and lipid profiling. In mutated HCA, we showed a repression of gluconeogenesis coordinated with an activation of glycolysis, citrate shuttle and fatty acid synthesis predicting elevated rates of lipogenesis. Moreover, the strong dowregulation of L-FABP suggests that impaired fatty acid trafficking may also contribute to the fatty phenotype. In addition, transcriptional profile analysis of the observed deregulated genes in non-HNF1a-mutated HCA as well as in non-tumor livers allowed us to define a specific signature of the HNF1a-mutated HCA. In theses tumors, lipid composition was dramatically modified according to the transcriptional deregulations identified in the fatty acid synthetic pathway. Surprisingly, lipogenesis activation did not operate through SREBP-1 and ChREBP that were repressed. We conclude that steatosis in HNF1a-mutated HCA results mainly from an aberrant promotion of lipogenesis that is linked to HNF1a inactivation and that is independent of both SREBP-1 and ChREBP activation. Finally, our findings have potential clinical implications since lipogenesis can be efficiently inhibited by targeted therapies. Keywords: Disease state analysis
2007-05-01 | GSE7473 | GEO
Project description:Biallelic inactivating mutations of the transcription factor 1 gene (TCF1), encoding hepatocyte nuclear factor 1a (HNF1a), were identified in 50% of hepatocellular adenomas (HCA) phenotypically characterized by a striking steatosis. To understand the molecular basis of this aberrant lipid storage, we performed a microarray transcriptome analysis validated by quantitative RT-PCR, western-blotting and lipid profiling. In mutated HCA, we showed a repression of gluconeogenesis coordinated with an activation of glycolysis, citrate shuttle and fatty acid synthesis predicting elevated rates of lipogenesis. Moreover, the strong dowregulation of L-FABP suggests that impaired fatty acid trafficking may also contribute to the fatty phenotype. In addition, transcriptional profile analysis of the observed deregulated genes in non-HNF1a-mutated HCA as well as in non-tumor livers allowed us to define a specific signature of the HNF1a-mutated HCA. In theses tumors, lipid composition was dramatically modified according to the transcriptional deregulations identified in the fatty acid synthetic pathway. Surprisingly, lipogenesis activation did not operate through SREBP-1 and ChREBP that were repressed. We conclude that steatosis in HNF1a-mutated HCA results mainly from an aberrant promotion of lipogenesis that is linked to HNF1a inactivation and that is independent of both SREBP-1 and ChREBP activation. Finally, our findings have potential clinical implications since lipogenesis can be efficiently inhibited by targeted therapies. Keywords: Disease state analysis In a first experiment, microarray analyses were applied to 8 HNF1-alpha mutated HCA and their corresponding non-tumor livers using cDNA in-house manufactured arrays following a randomized and blinded unbalanced design. RNA labelling, hybridization and analysis of fluorescence was carried out, as described in [Graudens et al., Genome Biol 2006, 7: R19; PMID: 16542501], considering that uneven numbers of samples were randomly allocated to each of the engineers who were not aware of sample phenotypes. To assess data reproducibility and minimize dye bias effects, each of the samples was measured four times, twice with Cy3 and twice with Cy5. To ensure robustness and flexibility in data analysis, a reference design was used with a universal reference sample (Stratagene, USA) serving as a baseline for the comparisons of tumor samples. Hybridizations were performed onto an 11K human array (11K_VJF-ARRAY, GPL3282), which provides a genome-wide coverage of functional pathways. Raw data were obtained using the ArrayVisionM-bM-^DM-" 7.0 software (Imaging Research Inc., USA); the resulting 3.2x106 hybridization data points collected from 32 arrays were stored in a MIAME-compliant database and pre-processed for normalization and filtering as described in [Graudens et al., Genome Biol 2006, 7: R19; PMID: 16542501]. In a second experiment, HG-U133A Affymetrix GeneChipTM arrays were used to compare the expression profiles of 5 HNF1-alpha mutated HCA and 4 non related non-tumor livers. RNA labelling, hybridization and analysis were carried out following the manufacturerM-bM-^@M-^Ys instructions(Affymetrix, Santa Clara, CA). Raw data were obtained by using Microarray Suite 5.0 (MAS5) software, embedded in the Affymetrix GeneChip Operating Software (Santa Clara, USA); the resulting raw numerical data (CEL files) - available as supplementary files - collected from 9 Affymetrix GeneChips were pre-processed for normalization and filtering as described in [Rebouissou et al., J Biol Chem 2007, in press; PMID: 17379603]. A platform-dependant statistical comparison was performed considering HNF1 alpha-mutated HCA versus non tumor liver tissues, using multiple testing procedures to evaluate statistical significance for differentially expressed genes, as described in [Graudens et al., Genome Biol 2006, 7: R19; PMID: 16542501] and in the supplemental experimental procedures in [Rebouissou et al., J Biol Chem 2007, in press; PMID: 17379603]. Thus, a combined cross-platform analysis was done considering the UGCluster Identifiants as a common primary key (Unigene Build184-June05). Additional information on the procedures is provided in the supplemental experimental procedures in [Rebouissou et al., J Biol Chem 2007, in press; PMID: 17379603].
2007-05-01 | E-GEOD-7473 | biostudies-arrayexpress
Project description:Lipogenesis in liver is highest in the postprandial state; insulin activates SREBP-1c, which transcriptionally activates genes involved in FA synthesis, whereas glucose activates carbohydrate-responsive element-binding protein (ChREBP), which activates both glycolysis and FA synthesis. Whether SREBP-1c and ChREBP act independently of one another is unknown. Here, we characterized mice with liver-specific deletion of ChREBP (L-Chrebp-/- mice). Hepatic ChREBP deficiency resulted in reduced mRNA levels of glycolytic and lipogenic enzymes, particularly in response to sucrose refeeding following fasting, a dietary regimen that elicits maximal lipogenesis. mRNA and protein levels of SREBP-1c, a master transcriptional regulator of lipogenesis, were also reduced in L-Chrebp-/- livers. Adeno-associated virus-mediated restoration of nuclear SREBP-1c in L-Chrebp-/- mice normalized expression of a subset of lipogenic genes, while not affecting glycolytic genes. Conversely, ChREBP overexpression alone failed to support expression of lipogenic genes in the livers of mice lacking active SREBPs as a result of Scap deficiency. Together, these data show that SREBP-1c and ChREBP are both required for coordinated induction of glycolytic and lipogenic mRNAs. Whereas SREBP-1c mediates insulin's induction of lipogenic genes, ChREBP mediates glucose's induction of both glycolytic and lipogenic genes. These overlapping, but distinct, actions ensure that the liver synthesizes FAs only when insulin and carbohydrates are both present.
| S-EPMC5832931 | biostudies-literature
Project description:Intramuscular fat (IMF) content is one of the key factors affecting meat quality. Carbohydrate response element binding protein (ChREBP) can promote glucose metabolism and fat synthesis by activating the expression of glycolysis and lipogenesis-related genes, but its function and regulatory mechanism in IMF are still unclear. This study evaluated the correlation between TG content and ChREBP expression level in muscles of different species to reveal the relationship between ChREBP and IMF. RNA-seq analysis showed that overexpressing ChREBP in C2C12 cells can significantly up-regulate fatty acid synthesis pathways, while significantly down-regulate the expression levels of muscle development pathways and related genes. In vivo, we found that overexpression of ChREBP or activation by fructose significantly increased the triglyceride content of the tibialis anterior muscle (TA) and the IMF content of yellow feather chicken leg and breast muscle in mice. And lipidomics data also found that feeding fructose can change the lipid composition of yellow feather broiler breast muscle and improve the flavor substances. This study demonstrated that ChREBP is a key gene regulating IMF deposition, providing a new target for genetic selection and nutritional regulation of IMF content.
2024-08-08 | GSE228899 | GEO
Project description:Epidemiologic and animal studies implicate overconsumption of fructose in the development of non-alcoholic fatty liver disease, but the molecular mechanisms underlying fructose-induced chronic liver diseases remains largely unknown. We present evidence supporting the essential function of the lipogenic transcription factor ChREBP in mediating adaptation response to fructose and protecting against fructose-induced hepatotoxicity. High-fructose diet (HFrD) activates hepatic lipogenesis via a ChREBP-dependent manner in wildtype mice, while inducing steatohepatitis in Chrebp-KO mice. In Chrebp-KO mouse livers, HFrD reduces levels of molecular chaperones and activates the CHOP-dependent unfolded protein response, whereas administration of chemical chaperone or Chop shRNA rescues liver injury. Gene expression profiling revealed elevated expression of cholesterol biosynthesis genes in Chrebp-KO livers after HFrD, in parallel with increased abundance of nuclear SREBP2. genes expression were compared between livers of wildtype mice fed 70%-fructose-diet v.s. regular chow, and between livers of Chrebp-/- mice v.s. wildtype mice fed 70%-fructose-diet.
2017-03-21 | GSE96820 | GEO
Project description:abstract1: Glycogen storage disease type Ia (GSD Ia) is an inborn error of metabolism caused by defective glucose-6-phosphatase (G6PC) activity. GSD Ia patients exhibit severe hepatomegaly due to glycogen and triglyceride (TG) accumulation in the liver. We have previously shown that the activity of Carbohydrate Response Element Binding Protein (ChREBP), a key regulator of glycolysis and de novo lipogenesis, is increased in GSD Ia. In the current study we assessed the contribution of ChREBP to non-alcoholic fatty liver disease (NAFLD) development in a mouse model for hepatic GSD Ia. PMID : 32083759 Abstract2:Glycogen storage disease type 1a (GSD Ia) is an inborn error of metabolism caused by a defect in glucose-6-phosphatase (G6PC) activity, which induces severe hepatomegaly and increases the risk for liver cancer in patients. Hepatic GSD Ia is characterized by constitutive activation of Carbohydrate Response Element Binding Protein (ChREBP), a glucose-sensitive transcription factor that has been proposed as a pro-oncogenic molecular switch that supports tumour progression. Here we studied the contribution of ChREBP signalling on liver disease progression and tumour susceptibility in a mouse model for GSD Ia. Hepatocyte-specific G6pc knockout (L-G6pc-/-) mice were treated with AAV-shChREBP to normalize hepatic ChREBP activity. Hepatic ChREBP normalization induced dysplastic liver growth, massively increased hepatocyte size and sensitized to hepatic inflammation and liver fibrosis in GSD Ia mice. Furthermore, the nuclear levels of the oncoprotein YAP were increased and its transcriptional targets were induced in ChREBP normalized GSD Ia mice. Hepatic ChREBP normalization furthermore induced DNA damage and mitotic activity in GSD Ia mice, while chromosomal instability, cGAS-STING pathway, senescence, and hepatocyte dedifferentiation gene signatures emerged. Upon ChREBP silencing in immortalized human hepatocytes, on the other hand, the induction of YAP target gene expression was paralleled by cell cycle arrest, cell death, and reduced proliferation. In conclusion, our findings indicate that ChREBP activity limits hepatomegaly while protecting against liver disease progression and hepatocellular tumour induction in GSD Ia. These results underline the importance to establish the context-specific roles of ChREBP to define its therapeutic potential. PMID:37085901
2023-04-22 | GSE143357 | GEO
Project description:By analogy to the c-Myc (Myc)/Max family of transcription factors, there also exists a “parallel” network of structurally and functionally related bHLH-ZIP proteins with certain Myc-like functions. Two closely related “Myc-like” paralogs termed Mondo A and MondoB/ChREBP (ChREBP) positively regulate gene expression in heterodimeric association with the Max-like factor Mlx. Myc is necessary to support liver cancer cell growth but not for normal hepatocyte proliferation. Here, we investigated the role for ChREBP and its relationship to Myc in these processes. Unlike Myc, ChREBP loss conferred a marked proliferative disadvantage to normal hepatocytes as did the loss of both ChREBP and Myc. In addition, hepatoblastomas (HBs) originating in myc-/-, chrebp-/- or myc-/-/chrebp-/- backgrounds grew significantly more slowly. Metabolic studies performed on livers and HBs arising in all three backgrounds showed marked differences in oxidative phosphorylation, fatty acid -oxidation (FAO) and the activity of pyruvate dehydrogenase. RNAseq of livers and HBs indicated seven distinct forms of target transcript regulation. Gene ontology analysis indicated that many transcripts de-regulated in the chrebp-/- background encode enzymes functioning in glycolysis, the TCA cycle and - and-FAO whereas those in myc-/- background encode enzymes for glycolysis, glutaminolysis and sterol biosynthesis. Transcript de-regulation in the double knockout group was similar but also included those involved in peroxisomal - and -FAO. Finally, we identified cooperative positive regulation by Myc and ChREBP of virtually all ribosomal protein genes. Our findings define the global proliferative, metabolic and transcriptional roles for the more general “Extended Myc Network” under both normal and neoplastic conditions.
2018-08-09 | GSE114634 | GEO
Project description:This project investigated proline hydroxylation of ChREBP. Proline hydroxylation was investigated in flag-IP enriched protein extracts from ChREBP-flag overexpressing HEK293 cells (A) and in ChREBP-IP enriched mouse liver protein (male, C57BL6/J) (B).
2020-10-19 | PXD019137 | Pride
Project description:Metabolic dysfunction within the liver is a major cause of human disease worldwide. Fat accumulation, de novo lipogenesis, and glycolysis are key drivers of hepatocyte reprogramming and the consequent metabolic dysfunction-associated steatotic liver disease (MASLD). The underpinning molecular mechanisms affected by steatosis and inflammation in the obese states remain unknown. Here we report that obesity leads to dysregulated expression of protein-tyrosine phosphatases (PTPs) in the liver. Protein Tyrosine Phosphatase Receptor Kappa (PTPRK) expression was increased in hepatocytes during steatosis and inflammation in humans and mice, and positively correlates with PPARγ-induced lipogenic signalling. Supporting this, PTPRK knockout mice displayed reduced fat accumulation in adipose tissue and liver after exposure to an obesogenic diet. Phosphoproteomic analysis in primary hepatocytes and hepatic metabolomics identified specific phosphotyrosine residues in fructose-1,6 bisphosphatase-1 and glycolysis regulation as targets of PTPRK. The changes in glycolysis and de novo lipogenesis revealed PTPRK was a driving force for metabolic reprogramming in hepatocytes. Moreover, hepatoma cell lines showed reduced colony-forming ability after PTPRK silencing in vitro, and PTPRK knockout mice developed smaller tumours after diethylnitrosamine-induced hepatocarcinogenesis in vivo. Through computational modelling, we identified selective PTPRK inhibitors. These compounds decreased glycolytic rates in hepatoma cell lines, PPARγ expression in primary hepatocytes and steatosis in obese mice. In conclusion, our study defines a novel mechanism for the development of MASLD, revealing a key role of PTPRK on hepatic glycolysis regulation with implications in lipid metabolism, and liver tumour development. We propose PTPRK as a potential target for metabolic liver dysfunction, and the identified inhibitors may represent promising candidates for therapy in obesity-associated liver diseases.
2024-09-26 | GSE247670 | GEO