RESUMEN
Most studies on TCF7L2 SNP variants in the pathogenesis of type 2 diabetes (T2D) focus on a role of the encoded transcription factor TCF4 in ß cells. Here, a mouse genetics approach shows that removal of TCF4 from ß cells does not affect their function, whereas manipulating TCF4 levels in the liver has major effects on metabolism. In Tcf7l2(-/-) mice, the immediate postnatal surge in liver metabolism does not occur. Consequently, pups die due to hypoglycemia. By combining chromatin immunoprecipitation with gene expression profiling, we identify a TCF4-controlled metabolic gene program that is acutely activated in the postnatal liver. In concordance, adult liver-specific Tcf7l2 knockout mice show reduced hepatic glucose production during fasting and display improved glucose homeostasis when maintained on high-fat diet. Furthermore, liver-specific TCF4 overexpression increases hepatic glucose production. These observations imply that TCF4 directly activates metabolic genes and that inhibition of Wnt signaling may be beneficial in metabolic disease.
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Diabetes Mellitus/genética , Diabetes Mellitus/metabolismo , Glucosa/metabolismo , Hígado/metabolismo , Redes y Vías Metabólicas , Proteína 2 Similar al Factor de Transcripción 7/metabolismo , Animales , Animales Recién Nacidos , Dieta Alta en Grasa , Ayuno/metabolismo , Islotes Pancreáticos/metabolismo , Ratones , Ratones Noqueados , Proteína 2 Similar al Factor de Transcripción 7/genética , Activación TranscripcionalRESUMEN
BMP and Wnt signaling pathways control essential cellular responses through activation of the transcription factors SMAD (BMP) and TCF (Wnt). Here, we show that regeneration of hematopoietic lineages following acute injury depends on the activation of each of these signaling pathways to induce expression of key blood genes. Both SMAD1 and TCF7L2 co-occupy sites with master regulators adjacent to hematopoietic genes. In addition, both SMAD1 and TCF7L2 follow the binding of the predominant lineage regulator during differentiation from multipotent hematopoietic progenitor cells to erythroid cells. Furthermore, induction of the myeloid lineage regulator C/EBPα in erythroid cells shifts binding of SMAD1 to sites newly occupied by C/EBPα, whereas expression of the erythroid regulator GATA1 directs SMAD1 loss on nonerythroid targets. We conclude that the regenerative response mediated by BMP and Wnt signaling pathways is coupled with the lineage master regulators to control the gene programs defining cellular identity.
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Proteínas Morfogenéticas Óseas/metabolismo , Hematopoyesis , Transducción de Señal , Vía de Señalización Wnt , Animales , Proteínas de Unión al ADN/metabolismo , Humanos , Regeneración , Proteína Smad1/metabolismo , Proteína 2 Similar al Factor de Transcripción 7/metabolismo , Pez CebraRESUMEN
Diabetes is far more prevalent in smokers than non-smokers, but the underlying mechanisms of vulnerability are unknown. Here we show that the diabetes-associated gene Tcf7l2 is densely expressed in the medial habenula (mHb) region of the rodent brain, where it regulates the function of nicotinic acetylcholine receptors. Inhibition of TCF7L2 signalling in the mHb increases nicotine intake in mice and rats. Nicotine increases levels of blood glucose by TCF7L2-dependent stimulation of the mHb. Virus-tracing experiments identify a polysynaptic connection from the mHb to the pancreas, and wild-type rats with a history of nicotine consumption show increased circulating levels of glucagon and insulin, and diabetes-like dysregulation of blood glucose homeostasis. By contrast, mutant Tcf7l2 rats are resistant to these actions of nicotine. Our findings suggest that TCF7L2 regulates the stimulatory actions of nicotine on a habenula-pancreas axis that links the addictive properties of nicotine to its diabetes-promoting actions.
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Trastornos del Metabolismo de la Glucosa/genética , Habénula/metabolismo , Transducción de Señal , Tabaquismo/complicaciones , Proteína 2 Similar al Factor de Transcripción 7/metabolismo , Animales , AMP Cíclico/metabolismo , Glucosa/metabolismo , Trastornos del Metabolismo de la Glucosa/metabolismo , Humanos , Ratones , Mutagénesis , Nicotina/metabolismo , Células PC12 , Páncreas/metabolismo , Ratas , Receptores Nicotínicos/metabolismo , Tabaquismo/genética , Tabaquismo/metabolismo , Proteína 2 Similar al Factor de Transcripción 7/genéticaRESUMEN
Thoracic aortic aneurysm (TAA) is characterized by dilation of the aortic root or ascending/descending aorta. TAA is a heritable disease that can be potentially life threatening. While 10%-20% of TAA cases are caused by rare, pathogenic variants in single genes, the origin of the majority of TAA cases remains unknown. A previous study implicated common variants in FBN1 with TAA disease risk. Here, we report a genome-wide scan of 1,351 TAA-affected individuals and 18,295 control individuals from the Cardiovascular Health Improvement Project and Michigan Genomics Initiative at the University of Michigan. We identified a genome-wide significant association with TAA for variants within the third intron of TCF7L2 following replication with meta-analysis of four additional independent cohorts. Common variants in this locus are the strongest known genetic risk factor for type 2 diabetes. Although evidence indicates the presence of different causal variants for TAA and type 2 diabetes at this locus, we observed an opposite direction of effect. The genetic association for TAA colocalizes with an aortic eQTL of TCF7L2, suggesting a functional relationship. These analyses predict an association of higher expression of TCF7L2 with TAA disease risk. In vitro, we show that upregulation of TCF7L2 is associated with BCL2 repression promoting vascular smooth muscle cell apoptosis, a key driver of TAA disease.
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Aneurisma de la Aorta Torácica/genética , Diabetes Mellitus Tipo 2/genética , Células Endoteliales/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/genética , Sitios de Carácter Cuantitativo , Proteína 2 Similar al Factor de Transcripción 7/genética , Aorta/metabolismo , Aorta/patología , Aneurisma de la Aorta Torácica/metabolismo , Aneurisma de la Aorta Torácica/patología , Estudios de Casos y Controles , Caspasa 3/genética , Caspasa 3/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patología , Células Endoteliales/patología , Regulación de la Expresión Génica , Genoma Humano , Estudio de Asociación del Genoma Completo , Humanos , Intrones , Michigan , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patología , Mutación , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteína 2 Similar al Factor de Transcripción 7/metabolismo , Proteína X Asociada a bcl-2/genética , Proteína X Asociada a bcl-2/metabolismoRESUMEN
BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common malignant tumors of the digestive system, and the exact mechanism of HCC is still unclear. Transcription factor 7 like 2 (TCF7L2) plays a pivotal role in cell proliferation and stemness maintenance. However, the exact mechanism of TCF7L2 in HCC remains unclear. METHODS: Clinical samples and public databases were used to analyze the expression and prognosis of TCF7L2 in HCC. The function of TCF7L2 in HCC was studied in vitro and in vivo. ChIP and luciferase assays were used to explore the molecular mechanism of TCF7L2. The relationship between TCF7L2 and NEDD9 was verified in HCC clinical samples by tissue microarrays. RESULTS: The expression of TCF7L2 was upregulated in HCC, and high expression of TCF7L2 was associated with poor prognosis of HCC patients. Overexpression of TCF7L2 promoted the metastasis of HCC in vitro and in vivo, while Knockdown of TCF7L2 showed the opposite effect. Mechanically, TCF7L2 activated neural precursor cell expressed developmentally downregulated protein 9 (NEDD9) transcription by binding to the -1522/-1509 site of the NEDD9 promoter region, thereby increasing the phosphorylation levels of AKT and mTOR. The combination of TCF7L2 and NEDD9 could distinguish the survival of HCC patients. CONCLUSIONS: This study demonstrated that TCF7L2 promotes HCC metastasis by activating AKT/mTOR pathway in a NEDD9-dependent manner, suggesting that potential of TCF7L2 and NEDD9 as prognostic markers and therapeutic targets for HCC.
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Proteínas Adaptadoras Transductoras de Señales , Carcinoma Hepatocelular , Regulación Neoplásica de la Expresión Génica , Neoplasias Hepáticas , Proteínas Proto-Oncogénicas c-akt , Transducción de Señal , Serina-Treonina Quinasas TOR , Proteína 2 Similar al Factor de Transcripción 7 , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/mortalidad , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/mortalidad , Proteínas Proto-Oncogénicas c-akt/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Proteína 2 Similar al Factor de Transcripción 7/metabolismo , Proteína 2 Similar al Factor de Transcripción 7/genética , Línea Celular Tumoral , Animales , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Fosfoproteínas/metabolismo , Fosfoproteínas/genética , Ratones , Pronóstico , Masculino , Metástasis de la Neoplasia , Femenino , Proliferación Celular , Persona de Mediana Edad , Ratones DesnudosRESUMEN
Vocalization is an essential medium for social signaling in birds and mammals. Periaqueductal gray (PAG) a conserved midbrain structure is believed to be responsible for innate vocalizations, but its molecular regulation remains largely unknown. Here, through a mouse forward genetic screening we identified one of the key Wnt/ß-catenin effectors TCF7L2/TCF4 controls ultrasonic vocalization (USV) production and syllable complexity during maternal deprivation and sexual encounter. Early developmental expression of TCF7L2 in PAG excitatory neurons is necessary for the complex trait, while TCF7L2 loss reduces neuronal gene expressions and synaptic transmission in PAG. TCF7L2-mediated vocal control is independent of its ß-catenin-binding domain but dependent of its DNA binding ability. Patient mutations associated with developmental disorders, including autism spectrum disorders, disrupt the transcriptional repression effect of TCF7L2, while mice carrying those mutations display severe USV impairments. Therefore, we conclude that TCF7L2 orchestrates gene expression in midbrain to control vocal production through its DNA binding but not transcription activation domain.
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Proteína 2 Similar al Factor de Transcripción 7 , beta Catenina , Ratones , Animales , beta Catenina/metabolismo , Proteína 2 Similar al Factor de Transcripción 7/genética , Proteína 2 Similar al Factor de Transcripción 7/metabolismo , Sustancia Gris Periacueductal/metabolismo , Transducción de Señal/fisiología , Mamíferos/genética , Mamíferos/metabolismo , ADN , Vocalización Animal/fisiologíaRESUMEN
BACKGROUND: Paired box 1 (PAX1) is a transcription factor and essential for the development of pharyngeal pouches-derived tissues, including thymus. PAX1 mutations are identified in Severe Combined Immunodeficiency (SCID) patients with Otofaciocervical Syndrome Type 2 (OTFCS2). However, despite the critical roles of PAX1 in embryonic development and diseases, detailed insights into its molecular mode of action are critically missing. METHODS: The repressing roles of PAX1 and SCID associated mutants on Wnt signaling pathway were investigated by luciferase reporter assays, qRT-PCR and in situ hybridization in HEK293FT, HCT116 cells and zebrafish embryos, respectively. Co-immunoprecipitation (co-IP) and western blotting assays were carried out to identify the molecular mechanisms underlying PAX1's role on Wnt signaling pathway. hESC based endoderm differentiation, flow cytometry, high-throughput sequencing data analysis, and qRT-PCR assays were utilized to determine the roles of PAX1 during endoderm differentiation. RESULTS: Here, we show that PAX1 represses canonical Wnt signaling pathway in vertebrate cells. Mechanically, PAX1 competes with SUMO E3 ligase PIASy to bind to TCF7L2, thus perturbing TCF7L2 SUMOylation level, further reducing its transcriptional activity and protein stability. Moreover, we reveal that PAX1 plays dual roles in hESC-derived definitive and foregut/pharyngeal endoderm cells, which give rise to the thymus epithelium, by inhibiting Wnt signaling. Importantly, our data show PAX1 mutations found in SCID patients significantly compromise the suppressing ability of PAX1 on Wnt signaling. CONCLUSIONS: Our study presents a novel molecular mode of action of PAX1 in regulation of canonical Wnt signaling and endoderm differentiation, thus providing insights for the molecular basis of PAX1 associated SCID, offering better understanding of the behavior of PAX1 in embryogenesis.
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Diferenciación Celular , Endodermo , Vía de Señalización Wnt , Pez Cebra , Humanos , Vía de Señalización Wnt/genética , Diferenciación Celular/genética , Endodermo/metabolismo , Endodermo/citología , Animales , Pez Cebra/genética , Células HEK293 , Proteína 2 Similar al Factor de Transcripción 7/metabolismo , Proteína 2 Similar al Factor de Transcripción 7/genética , Células HCT116 , Factores de Transcripción Paired Box/metabolismo , Factores de Transcripción Paired Box/genéticaRESUMEN
Mutations in the human kinesin family member 5A (KIF5A) gene were recently identified as a genetic cause of amyotrophic lateral sclerosis (ALS). Several KIF5A ALS variants cause exon 27 skipping and are predicted to produce motor proteins with an altered C-terminal tail (referred to as ΔExon27). However, the underlying pathogenic mechanism is still unknown. Here, we confirm the expression of KIF5A mutant proteins in patient iPSC-derived motor neurons. We perform a comprehensive analysis of ΔExon27 at the single-molecule, cellular, and organism levels. Our results show that ΔExon27 is prone to form cytoplasmic aggregates and is neurotoxic. The mutation relieves motor autoinhibition and increases motor self-association, leading to drastically enhanced processivity on microtubules. Finally, ectopic expression of ΔExon27 in Drosophila melanogaster causes wing defects, motor impairment, paralysis, and premature death. Our results suggest gain-of-function as an underlying disease mechanism in KIF5A-associated ALS.
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Esclerosis Amiotrófica Lateral , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/metabolismo , Animales , ADN sin Sentido/genética , Drosophila melanogaster , Mutación con Ganancia de Función , Humanos , Cinesinas/genética , Neuronas Motoras/metabolismo , Mutación , Proteína 2 Similar al Factor de Transcripción 7/metabolismoRESUMEN
Left-sided colorectal cancer (LSCC) and right-sided colorectal cancer (RSCC) belong to colorectal cancer happening at different positions, which exhibit different pathogenesis. MicroRNA (miRNA)s are widely known regulators in diverse carcinomas. This research aims to identify a differentially expressed miRNA that simultaneously regulates genes associated with LSCC and RSCC and reveal their regulatory relation in cell migration and invasion. Bioinformatics analyses were conducted to uncover the dysregulated functional genes in LSCC/RSCC and obtain their common targeted miRNAs. The expression pattern of miR-27a-3p, TCF7L2, and TGFBR2 in cancerous and adjacent tissues from LSCC/RSCC patients was assessed through qRT-PCR, followed by Pearson's correlation coefficients analysis. The interaction of miR-27a-3p with TCF7L2 or TGFBR2 was thereafter confirmed through luciferase reporter assay. TCF7L2 and TGFBR2 protein levels were assessed by western blotting after overexpressing level of miR-27a-3p. Cell migration and invasion were routinely examined by wound healing and transwell experiments, respectively. TCF7L2 and TGFBR2 were respectively identified and verified to be lowly expressed in LSCC and RSCC, both of them were predicted and confirmed as targets of miR-27a-3p. MiR-27a-3p elevation exacerbated migration and invasion of both LSCC and RSCC cells. The impacts of miR-27a-3p on migration and invasion could be blocked by overexpressing TCF7L2 in LSCC cells and also reversed by up-regulating TGFBR2 in RSCC cells. In general, miR-27a-3p accelerated the migration and invasion capabilities of LSCC and RSCC cells through negatively regulating TCF7L2 and TGFBR2, respectively, which might be an effective molecular target for the treatment of LSCC/RSCC.
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Neoplasias Colorrectales , MicroARNs , Receptor Tipo II de Factor de Crecimiento Transformador beta , Proteína 2 Similar al Factor de Transcripción 7 , Humanos , Movimiento Celular/genética , Proliferación Celular/genética , Neoplasias Colorrectales/genética , MicroARNs/genética , MicroARNs/metabolismo , Receptor Tipo II de Factor de Crecimiento Transformador beta/genética , Proteína 2 Similar al Factor de Transcripción 7/genéticaRESUMEN
BACKGROUND: The association between TCF7L2 and CAPN10 gene polymorphisms and gestational diabetes mellitus (GDM) has been explored in diverse populations across different geographical regions. Yet, most of these studies have been confined to a limited number of loci, resulting in inconsistent findings. In this study, we conducted a comprehensive review of published literature to identify studies examining the relationship between TCF7L2 and CAPN10 gene polymorphisms and the incidence of GDM in various populations. We specifically focused on five loci that were extensively reported in a large number of publications and performed a meta-analysis. METHODS: We prioritized the selection of SNPs with well-documented correlations established in existing literature on GDM. We searched eight Chinese and English databases: Cochrane, Elton B. Stephens. Company (EBSCO), Embase, Scopus, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang, and China Science and Technology Journal Database and retrieved all relevant articles published between the inception of the database and July 2022. The Newcastle Ottawa Scale (NOS) was used to evaluate the selected articles, and the odds ratio (OR) was used as the combined effect size index to determine the association between genotypes, alleles, and GDM using different genetic models. Heterogeneity between the studies was quantified and the I2 value calculated. Due to large heterogeneities between different ethnic groups, subgroup analysis was used to explore the correlation between genetic polymorphisms and the incidence of GDM in the different populations. The stability of the results was assessed using sensitivity analysis. Begg's and Egger's tests were used to assess publication bias. RESULTS: A total of 39 articles reporting data on 8,795 cases and 16,290 controls were included in the analysis. The frequency of the rs7901695 genotype was statistically significant between cases and controls in the European population (OR = 0.72, 95% CI: 0.65-0.86) and the American population (OR = 0.61, 95% CI: 0.48-0.77). The frequencies of rs12255372, rs7901695, rs290487, and rs2975760 alleles were also considerably different between the cases and controls in the populations analyzed. CONCLUSIONS: rs7903146, rs12255372, rs7901695, rs290487, and rs2975760 were associated with the incidence of GDM in different populations.
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Diabetes Mellitus Tipo 2 , Diabetes Gestacional , Proteína 2 Similar al Factor de Transcripción 7 , Femenino , Humanos , Embarazo , Alelos , Diabetes Gestacional/epidemiología , Diabetes Gestacional/genética , Predisposición Genética a la Enfermedad , Genotipo , Polimorfismo de Nucleótido Simple , Proteína 2 Similar al Factor de Transcripción 7/genéticaRESUMEN
Gestational diabetes mellitus (GDM) is one of the most frequent predictors of obstetric outcome among Romanian pregnant women. Thus, we aimed to investigate the role of rs7903146 (C/T) TCF7L2 gene polymorphism in the presence of GDM and to evaluate the influence on maternal-fetal outcomes in a cohort of pregnant women from Northern Transylvania. Our prospective case-control study was performed in a tertiary maternity center on 61 patients diagnosed with GDM and 55 normal pregnant patients. The patients were genotyped for rs7903146 (C/T) polymorphism of the TCF7L2 gene using the PCR-RFLP method between 24 and 28 weeks of gestation. The minor T allele was associated with a high risk of developing GDM (OR 1.71 [95% CI 0.82-3.59]) if both heterozygote and homozygote types were considered. Also, a higher risk of developing GDM was observed in homozygous carriers (OR 3.26 [95% CI 1.10-9.68]). Women with the TT genotype were more likely to require insulin therapy during pregnancy than other genotypes with a 5.67-fold increased risk ([1.61-19.97], p = 0.015). TT homozygote type was significantly associated with fetal macrosomia for birth weights greater than the 95th percentile (p = 0.034). The homozygous TT genotype is associated with an increased risk of developing GDM. Also, rs7903146 (C/T) TCF7L2 variant is accompanied by a high probability of developing insulin-dependent gestational diabetes mellitus (ID-GDM). The presence of at least one minor T allele was associated with a higher risk of fetal macrosomia.
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Diabetes Mellitus Tipo 1 , Diabetes Gestacional , Embarazo , Femenino , Humanos , Diabetes Gestacional/genética , Macrosomía Fetal , Estudios de Casos y Controles , Rumanía , Polimorfismo Genético , Insulina , Proteína 2 Similar al Factor de Transcripción 7/genéticaRESUMEN
We performed complex analysis of the association of polymorphic variants rs7903146 of the TCF7L2 gene and rs1801282 of the PPARG gene with metabolic parameters, insulin resistance, and ß-cell function in a group of patients with early signs of carbohydrate metabolism disturbances in a sample of Tyumen citizens. The study group consisted of 64 people (39 women, 25 men) aged 40-70 years. The distribution of frequencies of alleles and genotypes of the polymorphic markers rs7903146 and rs1801282 was analyzed and associations of carriage of major homozygous polymorphisms with various phenotypic traits were identified. Genotyping for polymorphic variants of TCF7L2 and PPARG genes was performed using allele-specific PCR with primers provided by Synthol company. Carriers of homozygotes for allele C of the polymorphic marker rs7903146 significantly differed from other respondents by a higher level of C-peptide, as well as by the presence of associations with waist circumference, elevated level of glycated hemoglobin, and arterial hypertension. Carriers of homozygotes for the allele C of the rs1801282 polymorphism of the PPARG gene differed from the group of carriers of homozygotes for the allele G and the group of heterozygote carriers by higher levels of triglycerides, as well as the presence of associations with waist circumference and the level of glycated hemoglobin.
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Diabetes Mellitus Tipo 2 , PPAR gamma , Proteína 2 Similar al Factor de Transcripción 7 , Femenino , Humanos , Masculino , Metabolismo de los Hidratos de Carbono , Diabetes Mellitus Tipo 2/genética , Genotipo , Hemoglobina Glucada/genética , Polimorfismo Genético/genética , Polimorfismo de Nucleótido Simple/genética , PPAR gamma/genética , Proteína 2 Similar al Factor de Transcripción 7/genéticaRESUMEN
AIMS/HYPOTHESIS: Non-alcoholic fatty liver disease (NAFLD) associated with type 2 diabetes may more easily progress towards severe forms of non-alcoholic steatohepatitis (NASH) and cirrhosis. Although the Wnt effector transcription factor 7-like 2 (TCF7L2) is closely associated with type 2 diabetes risk, the role of TCF7L2 in NAFLD development remains unclear. Here, we investigated how changes in TCF7L2 expression in the liver affects hepatic lipid metabolism based on the major risk factors of NAFLD development. METHODS: Tcf7l2 was selectively ablated in the liver of C57BL/6N mice by inducing the albumin (Alb) promoter to recombine Tcf7l2 alleles floxed at exon 5 (liver-specific Tcf7l2-knockout [KO] mice: Alb-Cre;Tcf7l2f/f). Alb-Cre;Tcf7l2f/f and their wild-type (Tcf7l2f/f) littermates were fed a high-fat diet (HFD) or a high-carbohydrate diet (HCD) for 22 weeks to reproduce NAFLD/NASH. Mice were refed a standard chow diet or an HCD to stimulate de novo lipogenesis (DNL) or fed an HFD to provide exogenous fatty acids. We analysed glucose and insulin sensitivity, metabolic respiration, mRNA expression profiles, hepatic triglyceride (TG), hepatic DNL, selected hepatic metabolites, selected plasma metabolites and liver histology. RESULTS: Alb-Cre;Tcf7l2f/f essentially exhibited increased lipogenic genes, but there were no changes in hepatic lipid content in mice fed a normal chow diet. However, following 22 weeks of diet-induced NAFLD/NASH conditions, liver steatosis was exacerbated owing to preferential metabolism of carbohydrate over fat. Indeed, hepatic Tcf7l2 deficiency enhanced liver lipid content in a manner that was dependent on the duration and amount of exposure to carbohydrates, owing to cell-autonomous increases in hepatic DNL. Mechanistically, TCF7L2 regulated the transcriptional activity of Mlxipl (also known as ChREBP) by modulating O-GlcNAcylation and protein content of carbohydrate response element binding protein (ChREBP), and targeted Srebf1 (also called SREBP1) via miRNA (miR)-33-5p in hepatocytes. Eventually, restoring TCF7L2 expression at the physiological level in the liver of Alb-Cre;Tcf7l2f/f mice alleviated liver steatosis without altering body composition under both acute and chronic HCD conditions. CONCLUSIONS/INTERPRETATION: In mice, loss of hepatic Tcf7l2 contributes to liver steatosis by inducing preferential metabolism of carbohydrates via DNL activation. Therefore, TCF7L2 could be a promising regulator of the NAFLD associated with high-carbohydrate diets and diabetes since TCF7L2 deficiency may lead to development of NAFLD by promoting utilisation of excess glucose pools through activating DNL. DATA AVAILABILITY: RNA-sequencing data have been deposited into the NCBI GEO under the accession number GSE162449 ( www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE162449 ).
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Diabetes Mellitus Tipo 2 , Enfermedad del Hígado Graso no Alcohólico , Ratones , Animales , Enfermedad del Hígado Graso no Alcohólico/genética , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Lipogénesis/genética , Ratones Endogámicos C57BL , Hígado/metabolismo , Hepatocitos/metabolismo , Dieta Alta en Grasa , Triglicéridos/metabolismo , Glucosa/metabolismo , Proteína 2 Similar al Factor de Transcripción 7/genética , Proteína 2 Similar al Factor de Transcripción 7/metabolismoRESUMEN
AIMS/HYPOTHESIS: TCF7L2 variants are the strongest genetic risk factor for type 2 diabetes. In individuals with type 1 diabetes, these variants are associated with a higher C-peptide AUC, a lower glucose AUC during an OGTT, single autoantibody positivity near diagnosis, particularly in individuals older than 12 years of age, and a lower frequency of type 1 diabetes-associated HLA genotypes. Based on initial observations from clinical cohorts, we tested the hypothesis that type 2 diabetes-predisposing TCF7L2 genetic variants are associated with a higher percentage of residual insulin-containing cells (ICI%) in pancreases of donors with type 1 diabetes, by examining genomic data and pancreatic tissue samples from the Network for Pancreatic Organ donors with Diabetes (nPOD) programme. METHODS: We analysed nPOD donors with type 1 diabetes (n=110; mean±SD age at type 1 diabetes onset 12.2±7.9 years, mean±SD diabetes duration 15.3±13.7 years, 53% male, 80% non-Hispanic White, 12.7% African American, 7.3% Hispanic) using data pertaining to residual beta cell number; quantified islets containing insulin-positive beta cells in pancreatic tissue sections; and expressed these values as a percentage of the total number of islets from each donor (mean ± SD ICI% 9.8±21.5, range 0-92.2). RESULTS: Donors with a high ICI% (≥5) (n=30; 27%) vs a low ICI% (<5) (n=80; 73%) were older at onset (15.3±6.9 vs 11.1±8 years, p=0.013), had a shorter diabetes duration at donor tissue procurement (7.0±7.4 vs 18.5±14.3 years, p<0.001), a higher African ancestry score (0.2±0.3 vs 0.1±0.2, p=0.043) and a lower European ancestry score (0.7±0.3 vs 0.9±0.3, p=0.023). After adjustment for age of onset (p=0.105), diabetes duration (p<0.001), BMI z score (p=0.145), sex (p=0.351) and African American race (p=0.053), donors with the TCF7L2 rs7903146 T allele (TC or TT, 45.5%) were 2.93 times (95% CI 1.02, 8.47) more likely to have a high ICI% than those without it (CC) (p=0.047). CONCLUSIONS/INTERPRETATION: Overall, these data support the presence of a type 1 diabetes endotype associated with a genetic factor that predisposes to type 2 diabetes, with donors in this category exhibiting less severe beta cell loss. It is possible that in these individuals the disease pathogenesis may include mechanisms associated with type 2 diabetes and thus this may provide an explanation for the poor response to immunotherapies to prevent type 1 diabetes or its progression in a subset of individuals. If so, strategies that target both type 1 diabetes and type 2 diabetes-associated factors when they are present may increase the success of prevention and treatment in these individuals.
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Diabetes Mellitus Tipo 1 , Diabetes Mellitus Tipo 2 , Masculino , Humanos , Preescolar , Niño , Adolescente , Adulto Joven , Adulto , Femenino , Insulina , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 2/genética , Proteína 2 Similar al Factor de Transcripción 7/genéticaRESUMEN
Clinical and basic neuroscience research is greatly benefited from the identification and characterization of lineage specific and developmental stage-specific markers. In the glial research community, histological markers that specifically label newly differentiated premyelinating oligodendrocytes are still scarce. Premyelinating oligodendrocyte markers, especially those of nuclear localization, enable researchers to easily quantify the rate of oligodendrocyte generation regardless of developmental ages. We propose that the transcription factor 7-like 2 (TCF7l2, mouse gene symbol Tcf7l2) is a useful nuclear marker that specifically labels newly generated premyelinating oligodendrocytes and promotes oligodendroglial lineage progression. Here, we highlight the controversial research history of TCF7l2 expression and function in oligodendroglial field and discuss previous experimental data justifying TCF7l2 as a specific nuclear marker for premyelinating oligodendrocytes during developmental myelination and remyelination. We conclude that TCF7l2 can be used alone or combined with pan-oligodendroglial lineage markers to identify newly differentiated or newly regenerated oligodendrocytes and quantify the rate of oligodendrocyte generation.
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Oligodendroglía , Remielinización , Animales , Ratones , Oligodendroglía/metabolismo , Diferenciación Celular/genética , Vaina de Mielina/metabolismo , Proteína 2 Similar al Factor de Transcripción 7/genética , Proteína 2 Similar al Factor de Transcripción 7/metabolismoRESUMEN
The transcription factor Stat3 is required for proliferation and pluripotency of embryonic stem cells; we have prepared and characterized fluorescent Stat3-reporter zebrafish based on repeats of minimal responsive elements. These transgenic lines mimic in vivo Stat3 expression patterns and are responsive to exogenous Stat3; notably, fluorescence is inhibited by both stat3 knockout and IL6/Jak/STAT inhibitors. At larval stages, Stat3 reporter activity correlates with proliferating regions of the brain, haematopoietic tissue and intestine. In the adult gut, the reporter is active in sparse proliferating cells, located at the base of intestinal folds, expressing the stemness marker sox9b and having the morphology of mammalian crypt base columnar cells; noteworthy, zebrafish stat3 mutants show defects in intestinal folding. Stat3 reporter activity in the gut is abolished with mutation of T cell factor 4 (Tcf7l2), the intestinal mediator of Wnt/ß-catenin-dependent transcription. The Wnt/ß-catenin dependence of Stat3 activity in the gut is confirmed by abrupt expansion of Stat3-positive cells in intestinal adenomas of apc heterozygotes. Our findings indicate that Jak/Stat3 signalling is needed for intestinal stem cell maintenance and possibly crucial in controlling Wnt/ß-catenin-dependent colorectal cancer cell proliferation.
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Mucosa Intestinal/metabolismo , Factor de Transcripción STAT3/metabolismo , Vía de Señalización Wnt , Proteínas de Pez Cebra/metabolismo , Pez Cebra/metabolismo , Animales , Animales Modificados Genéticamente/crecimiento & desarrollo , Animales Modificados Genéticamente/metabolismo , Intestinos/crecimiento & desarrollo , Intestinos/fisiología , Janus Quinasa 1 , Larva/crecimiento & desarrollo , Larva/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Factor de Transcripción SOX9/metabolismo , Factor de Transcripción STAT3/antagonistas & inhibidores , Factor de Transcripción STAT3/deficiencia , Factor de Transcripción STAT3/genética , Proteína 2 Similar al Factor de Transcripción 7/deficiencia , Proteína 2 Similar al Factor de Transcripción 7/genética , Proteína 2 Similar al Factor de Transcripción 7/metabolismo , Transcripción Genética/efectos de los fármacos , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/metabolismo , Proteínas Wnt/metabolismo , Vía de Señalización Wnt/efectos de los fármacos , Pez Cebra/crecimiento & desarrollo , Proteínas de Pez Cebra/antagonistas & inhibidores , Proteínas de Pez Cebra/deficiencia , Proteínas de Pez Cebra/genética , beta Catenina/metabolismoRESUMEN
Polymorphism of transcription factor 7-like 2 (TCF7L2) has a link with type 2 diabetes mellitus (T2DM) through ß cell dysfunction that causes defect in blood glucose homeostasis. This case-control study recruited 67 T2DM as cases and 65 age-matched healthy individuals as controls to determine whether the polymorphism rs12255372 (G > T) in the TCF7L2 gene have an association with T2DM in Bangladeshi population. Genomic DNA was purified from peripheral whole blood sample and direct Sanger sequencing was done for genotyping of SNP. Bivariate logistic regression was done to find out the association between genetic variant and T2DM. In our study, the minor T allele frequency was significantly more frequent in T2DM group than healthy controls (29.1% vs. 16.9%). After adjusting with confounding factors, heterozygous-genotype GT had higher odds of developing T2DM (OR 2.4; 95% CI: 1.0-5.5; p value = 0.04) and in dominant model, having SNP in TCF7L2 increased the risk of T2DM 2.3 times (95% CI: 1.0-5.2; p value = 0.04). In interaction model, genetic susceptible SNP cases interacted significantly with increasing age and BMI, female gender, and having family history of diabetes mellitus to develop T2DM (pinteraction < 0.001). Having minor T allele either in heterozygous or homozygous variant form of rs12255372 (G > T) TCF7L2 had significant association with T2DM. In conclusion, TCF7L2 gene variant increases risk of developing T2DM among the Bangladeshi population.
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Diabetes Mellitus Tipo 2 , Femenino , Humanos , Estudios de Casos y Controles , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/genética , Predisposición Genética a la Enfermedad , Polimorfismo de Nucleótido Simple/genética , Factor 1 de Transcripción de Linfocitos T/genética , Proteína 2 Similar al Factor de Transcripción 7/genéticaRESUMEN
FGF19/FGF15 is an endocrine regulator of hepatic bile salt and lipid metabolism, which has shown promising effects in the treatment of NASH in clinical trials. FGF19/15 is transcribed and released from enterocytes of the small intestine into enterohepatic circulation in response to bile-induced FXR activation. Previously, the TSS of FGF19 was identified to bind Wnt-regulated TCF7L2/encoded transcription factor TCF4 in colorectal cancer cells. Impaired Wnt signaling and specifical loss of function of its coreceptor LRP6 have been associated with NASH. We, therefore, examined if TCF7L2/TCF4 upregulates Fgf19 in the small intestine and restrains NASH through gut-liver crosstalk. We examined the mice globally overexpressing, haploinsufficient, and conditional knockout models of TCF7L2 in the intestinal epithelium. The TCF7L2+/- mice exhibited increased plasma bile salts and lipids and developed diet-induced fatty liver disease while mice globally overexpressing TCF7L2 were protected against these traits. Comprehensive in vivo analysis revealed that TCF7L2 transcriptionally upregulates FGF15 in the gut, leading to reduced bile synthesis and diminished intestinal lipid uptake. Accordingly, VilinCreert2 ; Tcf7L2fl/fl mice showed reduced Fgf19 in the ileum, and increased plasma bile. The global overexpression of TCF7L2 in mice with metabolic syndrome-linked LRP6R611C substitution rescued the fatty liver and fibrosis in the latter. Strikingly, the hepatic levels of TCF4 were reduced and CYP7a1 was increased in human NASH, indicating the relevance of TCF4-dependent regulation of bile synthesis to human disease. These studies identify the critical role of TCF4 as an upstream regulator of the FGF15-mediated gut-liver crosstalk that maintains bile and liver triglyceride homeostasis.
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Ácidos y Sales Biliares/metabolismo , Factores de Crecimiento de Fibroblastos/metabolismo , Íleon/metabolismo , Metabolismo de los Lípidos , Hígado/metabolismo , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Proteína 2 Similar al Factor de Transcripción 7/metabolismo , Animales , Colesterol 7-alfa-Hidroxilasa/genética , Colesterol 7-alfa-Hidroxilasa/metabolismo , Factores de Crecimiento de Fibroblastos/genética , Homeostasis , Proteína-6 Relacionada a Receptor de Lipoproteína de Baja Densidad/genética , Proteína-6 Relacionada a Receptor de Lipoproteína de Baja Densidad/metabolismo , Ratones , Ratones Endogámicos C57BL , Proteína 2 Similar al Factor de Transcripción 7/genéticaRESUMEN
BACKGROUND: Diabetes is a severe health burden for Bangladesh. Genetic polymorphism has been reported to be one of the major risk factors for diabetes in various studies. TCF7L2 (transcription factor 7 like 2) transcripts in the human ß-cell have effects on ß-cell survival, function, and Wnt signaling activation. This study aimed to evaluate the frequency and association of various polymorphisms namely TCF7L2 rs12255372 and rs7903146 among Bangladeshi patients with T2DM (Type 2 Diabetes Mellitus). METHODS: This case-control study included 300 patients with T2DM and 234 healthy individuals from two health facilities in the Chattogram Division of Bangladesh. Anthropometric measurements were assessed using a self-reported, structured, eight-item questionnaire. The polymorphisms were identified by PCR-RFLP and sequencing method. RESULTS: A strong association of T2DM with polymorphisms was observed, including rs12255372 (p = 0.0004) and rs7903146 (p = 0.005). It was observed that the risk genotype at rs12255372 was associated with age (p = 0.009), a family history of diabetes (p < 0.0001), and HbA1C (p < 0.0001). Furthermore, it was found that rs12255372 was substantially associated with hypertension (p = 0.03), eye problems (p = 0.01), and neurological abnormalities (p = 0.02). CONCLUSION: This study postulates that TCF7L2 genetic polymorphism is associated with the risk of T2DM among the studied Bangladeshi population. The findings should be replicated through more studies with a large number of samples and in different populations.
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Diabetes Mellitus Tipo 2 , Humanos , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/epidemiología , Estudios de Casos y Controles , Predisposición Genética a la Enfermedad , Polimorfismo de Nucleótido Simple/genética , Proteína 2 Similar al Factor de Transcripción 7/genética , GenotipoRESUMEN
Plasmacytoid dendritic cells (PDCs) represent a unique immune cell type specialized in type I interferon (IFN) secretion in response to viral nucleic acids. The molecular control of PDC lineage specification has been poorly understood. We report that basic helix-loop-helix transcription factor (E protein) E2-2/Tcf4 is preferentially expressed in murine and human PDCs. Constitutive or inducible deletion of murine E2-2 blocked the development of PDCs but not of other lineages and abolished IFN response to unmethylated DNA. Moreover, E2-2 haploinsufficiency in mice and in human Pitt-Hopkins syndrome patients was associated with aberrant expression profile and impaired IFN response of the PDC. E2-2 directly activated multiple PDC-enriched genes, including transcription factors involved in PDC development (SpiB, Irf8) and function (Irf7). These results identify E2-2 as a specific transcriptional regulator of the PDC lineage in mice and humans and reveal a key function of E proteins in the innate immune system.