RESUMEN
Long noncoding RNAs (lncRNAs) play an important role in the progression of hepatocellular carcinoma (HCC). Linc01612 is a novel lncRNA that function remains unknown in the progression of cancers, including HCC. In this study, we discovered that Linc01612 is significantly down-regulated in HCC tissues than in non-tumor tissues and correlated with poor prognosis. Linc01612 mainly localizes in the cytoplasm and functions as a tumor suppressor by repressing the growth and metastasis of hepatoma cells in vitro and in vivo. Mechanistically, in p53-expressing hepatoma cells, Linc01612 acts as a competitive endogenous RNA and promotes the expression of activation transcription factor 3 (ATF3) by sponging microRNA-494 (miR-494), which in turn inhibits MDM2-mediated ubiquitination of p53 and activates the p53 pathway. Furthermore, in p53-null hepatoma cells, Linc01612 exerts its biological functions by physically interacting with Y-box binding protein 1 protein (YBX1) and promoting the ubiquitin-mediated degradation of YBX1. Interestingly, the Linc01612-YBX1 signaling pathway is also present in p53-expressing hepatoma cells. In conclusion, our study indicated that Linc01612 is a functional lncRNA in HCC and Linc01612 may serve as a potential diagnostic biomarker and therapeutic target for HCC.
Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , MicroARNs , ARN Largo no Codificante , Factor de Transcripción Activador 3/genética , Factor de Transcripción Activador 3/metabolismo , Carcinoma Hepatocelular/metabolismo , Línea Celular Tumoral , Proliferación Celular/genética , Progresión de la Enfermedad , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Neoplasias Hepáticas/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Factor de Transcripción 3/genética , Factor de Transcripción 3/metabolismo , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Ubiquitinación/genética , Proteína 1 de Unión a la Caja Y/genética , Proteína 1 de Unión a la Caja Y/metabolismoRESUMEN
BACKGROUND: Transcription factor 3 (TCF3) plays pivotal roles in embryonic development, stem cell maintenance and carcinogenesis. However, its role in hepatocellular carcinoma (HCC) remains largely unknown. This study aimed to analyze the correlation between TCF3 expression and clinicopathological features of HCC, and further explore the underlying mechanism in HCC progression. METHODS: The expression of TCF3 was collected from the Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) HCC datasets, and further confirmed by immunostaining and Western blotting assays. The correlation between TCF3 expression and the clinicopathological features was evaluated. Bioinformatical analysis and in vitro experiments were conducted to explore the potential role of TCF3 in HCC development. RESULTS: Both the mRNA and protein levels of TCF3 were significantly higher in HCC tumor tissues compared to tumor adjacent tissues (P < 0.001 and P < 0.01). Analysis based on TCGA datasets showed that TCF3 was positively correlated with tumor clinical stage and grade, and patients with high TCF3 expression had shorter overall survival (P = 0.012), disease-specific survival (P = 0.022) and progression-free survival (P = 0.013). Similarly, the immunostaining results revealed that the high expression of TCF3 was closely correlated with tumor size (P = 0.001) and TNM stage (P = 0.002), and TCF3 was an independent risk factor of HCC. In vitro study exhibited that TCF3 knockdown dramatically suppressed cancer cell proliferation, and the underlying mechanism might be that the silencing of TCF3 reduced the expression of critical regulating proteins towards cell cycle and proteins involved in Wnt signaling pathways. CONCLUSIONS: TCF3 expression is significantly elevated in HCC and positively associated with the tumor size and TNM stage, as well as poor prognosis of HCC patients. The mechanism might be that TCF3 promotes cancer cell proliferation via activating Wnt signaling pathway.
Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Factor de Transcripción 3 , Vía de Señalización Wnt , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Carcinoma Hepatocelular/patología , Línea Celular Tumoral , Proliferación Celular/genética , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Hepáticas/patología , Pronóstico , Factor de Transcripción 3/genética , Factor de Transcripción 3/metabolismoRESUMEN
Increased fluid flow shear stress (FFSS) in solitary kidney alters podocyte function in vivo. FFSS-treated cultured podocytes show upregulated AKT-GSK3ß-ß-catenin signaling. The present study was undertaken to confirm (i) the activation of ß-catenin signaling in podocytes in vivo using unilaterally nephrectomized (UNX) TOPGAL mice with the ß-galactosidase reporter gene for ß-catenin activation, (ii) ß-catenin translocation in FFSS-treated mouse podocytes, and (iii) ß-catenin signaling using publicly available data from UNX mice. The UNX of TOPGAL mice resulted in glomerular hypertrophy and increased the mesangial matrix consistent with hemodynamic adaptation. Uninephrectomized TOPGAL mice showed an increased ß-galactosidase expression at 4 weeks but not at 12 weeks, as assessed using immunofluorescence microscopy (p < 0.001 at 4 weeks; p = 0.16 at 12 weeks) and X-gal staining (p = 0.008 at 4 weeks; p = 0.65 at 12 weeks). Immunofluorescence microscopy showed a significant increase in phospho-ß-catenin (Ser552, p = 0.005) at 4 weeks but not at 12 weeks (p = 0.935) following UNX, and the levels of phospho-ß-catenin (Ser675) did not change. In vitro FFSS caused a sustained increase in the nuclear translocation of phospho-ß-catenin (Ser552) but not phospho-ß-catenin (Ser675) in podocytes. The bioinformatic analysis of the GEO dataset, #GSE53996, also identified ß-catenin as a key upstream regulator. We conclude that transcription factor ß-catenin mediates FFSS-induced podocyte (glomerular) injury in solitary kidney.
Asunto(s)
Tasa de Filtración Glomerular , Mecanotransducción Celular , Podocitos/metabolismo , Riñón Único/metabolismo , beta Catenina/metabolismo , Animales , Línea Celular , Bases de Datos Genéticas , Modelos Animales de Enfermedad , Genes fos , Operón Lac , Factor de Unión 1 al Potenciador Linfoide/genética , Ratones Transgénicos , Podocitos/patología , Regiones Promotoras Genéticas , Riñón Único/genética , Riñón Único/patología , Riñón Único/fisiopatología , Estrés Mecánico , Factor de Transcripción 3/genética , beta Catenina/genéticaRESUMEN
Yanbian yellow cattle are one of the top five largest breeds of cattle in China. We had previously found that bta-miR-1271 is differentially expressed in the longissimus dorsi muscles of Yanbian yellow bulls and steers. However, whether bta-miR-1271 affects bovine fat formation is unclear. In this study, we used target gene prediction, dual-luciferase reporter assay, and transfection-mediated overexpression and inhibition of bta-miR-1271 in a culture of Yanbian yellow cattle preadipocytes to investigate the role of bta-miR-1271 in adipogenesis. We showed that bta-miR-1271 directly targets the 3'-untranslated region (3'-UTR) of the activating transcription factor 3 (ATF3) mRNA and downregulates its expression. Overexpression of bta-miR-1271 enforced by the miRNA mimics promoted triglyceride accumulation and significantly upregulated expression of the adipogenic peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT enhancer-binding protein α (C/EBPα) genes at both the protein and mRNA levels, as demonstrated by RT-qPCR and Western blot analyses. Conversely, inhibition of bta-miR-1271 expression produced the opposite effect. Our results show that bta-miR-1271 regulates differentiation of Yanbian yellow cattle preadipocytes by inhibiting ATF3 expression, which highlights the importance of microRNA-mediated regulation of adipogenesis. miR-1271 and its target gene(s) may provide a new research direction for investigating biological agents affecting intramuscular fat deposition in cattle.
Asunto(s)
Factor de Transcripción Activador 3/genética , Adipocitos/citología , Adipocitos/metabolismo , MicroARNs/metabolismo , Factor de Transcripción 3/metabolismo , Regiones no Traducidas 3' , Factor de Transcripción Activador 3/metabolismo , Adipogénesis/fisiología , Animales , Bovinos , Diferenciación Celular/fisiología , Células Cultivadas , Femenino , Masculino , MicroARNs/genética , PPAR gamma/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Factor de Transcripción 3/genéticaRESUMEN
Puberty is a whole-body event, driven by the hypothalamic integration of peripheral signals such as leptin or IGF-1. In the process of puberty, reproductive development is simultaneous to growth, including muscle growth. To enhance our understanding of muscle function related to puberty, we performed transcriptome analyses of muscle samples from six pre- and six post-pubertal Brahman heifers (Bos indicus). Our aims were to perform differential expression analyses and co-expression analyses to derive a regulatory gene network associate with puberty. As a result, we identified 431 differentially expressed (DEx) transcripts (genes and non-coding RNAs) when comparing pre- to post-pubertal average gene expression. The DEx transcripts were compared with all expressed transcripts in our samples (over 14,000 transcripts) for functional enrichment analyses. The DEx transcripts were associated with "extracellular region," "inflammatory response" and "hormone activity" (adjusted p < .05). Inflammatory response for muscle regeneration is a necessary aspect of muscle growth, which is accelerated during puberty. The term "hormone activity" may signal genes that respond to progesterone signalling in the muscle, as the presence of this hormone is an important difference between pre- and post-pubertal heifers in our experimental design. The DEx transcript with the highest average expression difference was a mitochondrial gene, ENSBTAG00000043574 that might be another important link between energy metabolism and puberty. In the derived co-expression gene network, we identified six hub genes: CDC5L, MYC, TCF3, RUNX2, ATF2 and CREB1. In the same network, 48 key regulators of DEx transcripts were identified, using a regulatory impact factor metric. The hub gene TCF3 was also a key regulator. The majority of the key regulators (22 genes) are members of the zinc finger family, which has been implicated in bovine puberty in other tissues. In conclusion, we described how puberty may affect muscle gene expression in cattle.
Asunto(s)
Bovinos/genética , Regulación de la Expresión Génica , Músculos/metabolismo , Factor de Transcripción 3/genética , Animales , Bovinos/metabolismo , Femenino , Factor de Transcripción 3/metabolismoRESUMEN
The E-protein transcription factors guide immune cell differentiation, with E12 and E47 (hereafter called E2A) being essential for B-cell specification and maturation. E2A and the oncogenic chimera E2A-PBX1 contain three transactivation domains (ADs), with AD1 and AD2 having redundant, independent, and cooperative functions in a cell-dependent manner. AD1 and AD2 both mediate their functions by binding to the KIX domain of the histone acetyltransferase paralogues CREB-binding protein (CBP) and E1A-binding protein P300 (p300). This interaction is necessary for B-cell maturation and oncogenesis by E2A-PBX1 and occurs through conserved ΦXXΦΦ motifs (with Φ denoting a hydrophobic amino acid) in AD1 and AD2. However, disruption of this interaction via mutation of the KIX domain in CBP/p300 does not completely abrogate binding of E2A and E2A-PBX1. Here, we determined that E2A-AD1 and E2A-AD2 also interact with the TAZ2 domain of CBP/p300. Characterization of the TAZ2:E2A-AD1(1-37) complex indicated that E2A-AD1 adopts an α-helical structure and uses its ΦXXΦΦ motif to bind TAZ2. Whereas this region overlapped with the KIX recognition region, key KIX-interacting E2A-AD1 residues were exposed, suggesting that E2A-AD1 could simultaneously bind both the KIX and TAZ2 domains. However, we did not detect a ternary complex involving E2A-AD1, KIX, and TAZ2 and found that E2A containing both intact AD1 and AD2 is required to bind to CBP/p300. Our findings highlight the structural plasticity and promiscuity of E2A-AD1 and suggest that E2A binds both the TAZ2 and KIX domains of CBP/p300 through AD1 and AD2.
Asunto(s)
Proteína de Unión a CREB/química , Proteína p300 Asociada a E1A/genética , Dominios Proteicos/genética , Factor de Transcripción 3/química , Linfocitos B/química , Linfocitos B/metabolismo , Proteína de Unión a CREB/genética , Proteína de Unión a CREB/ultraestructura , Proteína p300 Asociada a E1A/química , Proteína p300 Asociada a E1A/ultraestructura , Proteínas de Homeodominio/química , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/ultraestructura , Humanos , Mutación/genética , Proteínas de Fusión Oncogénica/química , Proteínas de Fusión Oncogénica/genética , Proteínas de Fusión Oncogénica/ultraestructura , Unión Proteica/genética , Conformación Proteica , Factor de Transcripción 3/genética , Factor de Transcripción 3/ultraestructuraRESUMEN
BACKGROUND: The E2A gene, which encodes two basic helix-loop-helix transcription factors, E12 and E47, regulates colorectal cancer progression and epithelial-mesenchymal transition. However, whether E2A regulates the tumor-initiating capacity of colorectal cancer is unclear. Thus, we have studied E2A expression in the initiation of colorectal cancer in vivo and in vitro. METHODS: Immunohistochemistry and immunoblot were performed to determine protein levels of E2A in colorectal cancer specimens and cells. RNAi was employed to downregulate E2A expression, and the subsequent change in protein level was evaluated by immunoblot. Sphere-forming assay and enumeration of liver metastasis in mouse models were used to identify the tumor formation ability of colorectal cancer cells. RESULTS: E2A expression in colorectal cancer clinical specimens was inversely associated with patients' progression-free survival. Functional studies demonstrated that E2A significantly decreased tumor formation in vitro and in vivo. Furthermore, nuclear translocation of beta-catenin and activation of the Wnt/beta-catenin pathway occurred after suppression of E2A in colorectal cancer cells. FoxM1 was identified as a down-stream target by mRNA microarray, implying that FoxM1 plays a main role in determining how E2A regulates the tumor-initiating capacity of colorectal cancer. CONCLUSION: E2A suppresses tumor-initiating capacity by targeting the FoxM1-Wnt/ß-catenin pathway.
Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Neoplasias Colorrectales/metabolismo , Vía de Señalización Wnt , Adulto , Anciano , Anciano de 80 o más Años , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Células CACO-2 , Transformación Celular Neoplásica/genética , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/mortalidad , Neoplasias Colorrectales/patología , Transición Epitelial-Mesenquimal , Femenino , Proteína Forkhead Box M1/genética , Proteína Forkhead Box M1/metabolismo , Humanos , Neoplasias Hepáticas/secundario , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Persona de Mediana Edad , Supervivencia sin Progresión , Factor de Transcripción 3/biosíntesis , Factor de Transcripción 3/genética , beta Catenina/metabolismoRESUMEN
The superfamily of basic-Helix-Loop-Helix (bHLH) transcription factors influence cell fate in all three embryonic germ layers, and the tissue-specific class II factors have received prominent attention for their potent ability to direct differentiation during development and in cellular reprogramming. The activity of many class II bHLH proteins driving differentiation, and the inhibitory class VI bHLH factor Hes1, is controlled by phosphorylation on multiple sites by Cyclin-dependent kinases (Cdks). As class II proteins are generally thought to be active through hetero-dimerisation with the ubiquitously expressed class I E proteins, regulation of class I transcription factors such as E47 may influence the activity of multiple tissue-specific bHLH proteins. Using differentiation of nerve and muscle in Xenopus frog embryos as a model system, we set out to explore whether with the ubiquitously expressed class I E protein E47 that hetero-dimerises with Class II bHLHs to control their activity, is also regulated by multi-site phosphorylation. We demonstrate that E47 can be readily phosphorylated by Cdks on multiple sites in vitro, while ectopically-expressed E47 exists in multiple phosphorylated forms in Xenopus embryos. Preventing multi-site phosphorylation using a phospho-mutant version of E47 enhances the neurogenic and myogenic activity of three different class II bHLH reprogramming factors, and also when E47 acts in hetero-dimerisation with endogenous proteins. Mechanistically, unlike phospho-regulation of class II bHLH factors, we find that preventing phosphorylation of E47 increases the amount of chromatin-bound E47 protein but without affecting its overall protein stability. Thus, multi-site phosphorylation is a conserved regulatory mechanism across the bHLH superfamily that can be manipulated to enhance cellular differentiation.
Asunto(s)
Desarrollo de Músculos , Neurogénesis , Factor de Transcripción 3/metabolismo , Proteínas de Xenopus/metabolismo , Xenopus laevis/embriología , Animales , Ratones , Mutación , Fosforilación , Factor de Transcripción 3/genética , Proteínas de Xenopus/genética , Xenopus laevis/metabolismoRESUMEN
Glucocorticoids (GCs) are effective drugs, but their clinical use is compromised by severe side effects including hyperglycemia, hyperlipidemia and obesity. They bind to the Glucocorticoid Receptor (GR), which acts as a transcription factor. The activation of metabolic genes by GR is thought to underlie these adverse effects. We identify the bHLH factor E47 as a modulator of GR target genes. Using mouse genetics, we find that E47 is required for the regulation of hepatic glucose and lipid metabolism by GR, and that loss of E47 prevents the development of hyperglycemia and hepatic steatosis in response to GCs. Here we show that E47 and GR co-occupy metabolic promoters and enhancers. E47 is needed for the efficient recruitment of GR and coregulators such as Mediator to chromatin. Altogether, our results illustrate how GR and E47 regulate hepatic metabolism, and might provide an entry point for novel therapies with reduced side effects.
Asunto(s)
Glucocorticoides/farmacología , Hígado/efectos de los fármacos , Receptores de Glucocorticoides/genética , Factor de Transcripción 3/genética , Animales , Inmunoprecipitación de Cromatina/métodos , Hígado Graso/metabolismo , Perfilación de la Expresión Génica , Glucocorticoides/efectos adversos , Glucosa/genética , Glucosa/metabolismo , Metabolismo de los Lípidos/genética , Hígado/metabolismo , Masculino , Ratones Noqueados , Factor de Transcripción 3/metabolismoRESUMEN
Hepatocyte growth factor (HGF) is a multifunctional protein that contains angiogenic and neurotrophic properties. In the current study, we investigated the analgesic effects of HGF by using a plasmid DNA that was designed to express 2 isoforms of human HGF-pCK-HGF-X7 (or VM202)-in a chronic constriction injury (CCI) -induced mouse neuropathic pain model. Intramuscular injection of pCK-HGF-X7 into proximal thigh muscle induced the expression of HGF in the muscle, sciatic nerve, and dorsal root ganglia (DRG). This gene transfer procedure significantly attenuated mechanical allodynia and thermal hyperalgesia after CCI. Injury-induced expression of activating transcription factor 3, calcium channel subunit α2δ1, and CSF1 in the ipsilateral DRG neurons was markedly down-regulated in the pCK-HGF-X7-treated group, which suggested that HGF might exert its analgesic effects by inhibiting pain-mediating genes in the sensory neurons. In addition, suppressed CSF1 expression in DRG neurons by pCK-HGF-X7 treatment was accompanied by a noticeable suppression of the nerve injury-induced glial cell activation in the spinal cord dorsal horn. Taken together, our data show that pCK-HGF-X7 attenuates nerve injury-induced neuropathic pain by inhibiting pain-related factors in DRG neurons and subsequent spinal cord glial activation, which suggests its therapeutic efficacy in the treatment of neuropathic pain.-Nho, B., Lee, J., Lee, J., Ko, K. R., Lee, S. J., Kim, S. Effective control of neuropathic pain by transient expression of hepatocyte growth factor in a mouse chronic constriction injury model.
Asunto(s)
Factor de Crecimiento de Hepatocito/genética , Neuralgia/genética , Neuralgia/terapia , Traumatismos de la Médula Espinal/genética , Animales , Canales de Calcio/genética , Constricción , Modelos Animales de Enfermedad , Regulación hacia Abajo/genética , Ganglios Espinales/metabolismo , Técnicas de Transferencia de Gen , Terapia Genética/métodos , Humanos , Hiperalgesia/genética , Factor Estimulante de Colonias de Macrófagos/genética , Masculino , Ratones , Ratones Endogámicos ICR , Músculo Esquelético/metabolismo , Neuroglía/metabolismo , Nervio Ciático/metabolismo , Células Receptoras Sensoriales/metabolismo , Asta Dorsal de la Médula Espinal/metabolismo , Factor de Transcripción 3/genéticaRESUMEN
BACKGROUND: The bHLH transcription factor TWIST1 plays a key role in the embryonic development and in tumorigenesis. Some loss-of-function mutations of the TWIST1 gene have been shown to cause an autosomal dominant craniosynostosis, known as the Saethre-Chotzen syndrome (SCS). Although the functional impacts of many TWIST1 mutations have been experimentally reported, little is known on the molecular mechanisms underlying their loss-of-function. In a previous study, we highlighted the predictive value of in silico molecular dynamics (MD) simulations in deciphering the molecular function of TWIST1 residues. RESULTS: Here, since the substitution of the arginine 154 amino acid by a glycine residue (R154G) is responsible for the SCS phenotype and the substitution of arginine 154 by a proline experimentally decreases the dimerizing ability of TWIST1, we investigated the molecular impact of this point mutation using MD approaches. Consistently, MD simulations highlighted a clear decrease in the stability of the α-helix during the dimerization of the mutated R154P TWIST1/E12 dimer compared to the wild-type TE complex, which was further confirmed in vitro using immunoassays. CONCLUSIONS: Our study demonstrates that MD simulations provide a structural explanation for the loss-of-function associated with the SCS TWIST1 mutation and provides a proof of concept of the predictive value of these MD simulations. This in silico methodology could be used to determine reliable pharmacophore sites, leading to the application of docking approaches in order to identify specific inhibitors of TWIST1 complexes.
Asunto(s)
Simulación de Dinámica Molecular , Proteínas Nucleares/química , Proteínas Nucleares/genética , Mutación Puntual , Factor de Transcripción 3/química , Proteína 1 Relacionada con Twist/química , Proteína 1 Relacionada con Twist/genética , Secuencia de Aminoácidos , Animales , Arginina/química , Arginina/genética , Simulación por Computador , Cristalografía por Rayos X , Glicina/química , Glicina/genética , Humanos , Ratones , Fosforilación , Conformación Proteica , Multimerización de Proteína , Homología de Secuencia , Factor de Transcripción 3/genéticaRESUMEN
The Swedish-Norwegian Coldblooded trotter (CBT) is a local breed in Sweden and Norway mainly used for harness racing. Previous studies have shown that a mutation from cytosine (C) to adenine (A) in the doublesex and mab-3 related transcription factor 3 (DMRT3) gene has a major impact on harness racing performance of different breeds. An association of the DMRT3 mutation with early career performance has also been suggested. The aim of the current study was to investigate this proposed association in a randomly selected group of CBTs. 769 CBTs (485 raced, 284 unraced) were genotyped for the DMRT3 mutation. The association with racing performance was investigated for 13 performance traits and three different age intervals: 3 years, 3 to 6 years, and 7 to 10 years of age, using the statistical software R. Each performance trait was analyzed for association with DMRT3 using linear models. The results suggest no association of the DMRT3 mutation with precocity (i.e. performance at 3 years of age). Only two traits (race time and number of disqualifications) were significantly different between the genotypes, with AA horses having the fastest times and CC horses having the highest number of disqualifications at 3 years of age. The frequency of the AA genotype was significantly lower in the raced CBT sample compared with the unraced sample and less than 50% of the AA horses participated in a race. For the age intervals 3 to 6 and 7 to 10 years the AA horses also failed to demonstrate significantly better performance than the other genotypes. Although suggested as the most favorable genotype for racing performance in Standardbreds and Finnhorses across all ages, the AA genotype does not appear to be associated with superior performance, early or late, in the racing career of CBTs.
Asunto(s)
Caballos/genética , Caballos/fisiología , Condicionamiento Físico Animal , Polimorfismo de Nucleótido Simple , Factor de Transcripción 3/genética , Animales , Cruzamiento , Marcha , Genotipo , Mutación , Noruega , Mutación Puntual , Carrera , SueciaRESUMEN
Objective: To investigate the association of ulcerative colitis (UC) with fork head/winged helix transcription factor-3 (Foxp3) polymorphisms in Han population in Zhejiang province, China. Methods: A total of 381 UC patients and 490 healthy controls were enrolled in this study.The four single nucleotide polymorphisms (SNPs) of Foxp3 (rs3761547, rs2232365, rs2294021, rs3761548) were examined by SNaPshot.The analyses of linkage disequilibrium (LD) and haplotype were also performed in all study subjects. Results: When male and female UC patients were compared with their corresponding controls respectively, the alleles and genotypes of the four SNPs were not statistically different (all P>0.05). According to severity and location of the disease, the UC patients were divided into different subgroups. The alleles (C, G, A) of (rs2232365, rs2294021, rs3761548) were more frequent in male patients with severe UC than in the male controls (69.6% vs 34.3%, P=0.001; 69.6% vs 34.3%, P=0.001; 39.1% vs 14.4%, P=0.002, respectively). As compared with the female controls, the alleles (C, G, A) and genotypes (TC+ CC, AG+ GG, CA+ AA) of (rs2232365, rs2294021, rs3761548) were significantly increased in the female patients with severe UC (51.9% vs 38.0%, 63.5% vs 39.2%, 53.8% vs 21.4%, 80.8% vs 57.7%, 84.6% vs 58.4%, 76.9% vs 34.7%, all P<0.05). The four SNPs above were shown to be in a strong LD both in male and in female subjects.When male and female UC patients were compared with their corresponding controls respectively, nevertheless, each haplotype frequency was not statistically different (all P>0.05). Conclusions:Foxp3 (rs2232365, rs2294021, rs3761548) variations might engender the increased risk of severe UC in Chinese Han patients.
Asunto(s)
Pueblo Asiatico/genética , Colitis Ulcerosa/genética , Factor de Transcripción 3/genética , Factores de Transcripción Winged-Helix/genética , Adulto , Alelos , China , Colitis Ulcerosa/etnología , Femenino , Frecuencia de los Genes , Genotipo , Haplotipos , Humanos , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido SimpleRESUMEN
The transcription factor Foxp3 dominantly controls regulatory T (Treg) cell function, and only its continuous expression guarantees the maintenance of full Treg cell-suppressive capacity. However, transcriptional regulators maintaining Foxp3 transcription are incompletely described. Here, we report that high E47 transcription factor activity in Treg cells resulted in unstable Foxp3 expression. Under homeostatic conditions, Treg cells expressed high levels of the E47 antagonist Id3, thus restricting E47 activity and maintaining Foxp3 expression. In contrast, stimulation of Id3-deficient or E47-overexpressing Treg cells resulted in the loss of Foxp3 expression in a subset of Treg cells in vivo and in vitro. Mechanistic analysis indicated that E47 activated expression of the transcription factor Spi-B and the suppressor of cytokine signaling 3 (SOCS3), which both downregulated Foxp3 expression. These findings demonstrate that the balance of Id3 and E47 controls the maintenance of Foxp3 expression in Treg cells and, thus, contributes to Treg cell plasticity.
Asunto(s)
Factores de Transcripción Forkhead/genética , Proteínas Inhibidoras de la Diferenciación/genética , Proteínas Proto-Oncogénicas c-ets/genética , Proteína 3 Supresora de la Señalización de Citocinas/genética , Linfocitos T Reguladores/metabolismo , Factor de Transcripción 3/genética , Animales , Regulación de la Expresión Génica , Redes Reguladoras de Genes/genética , RatonesRESUMEN
Tissue damage is one of the major etiological factors in the emergence of chronic/persistent pain, although mechanisms remain enigmatic. Using incision of the back skin of adult rats as a model for tissue damage, we observed sensitization in a nociceptive reflex enduring to 28days post-incision (DPI). To determine if the enduring behavioral changes corresponded with a long-term impact of tissue damage on sensory neurons, we examined the temporal expression profile of injury-regulated genes and the electrophysiological properties of traced dorsal root ganglion (DRG) sensory neurons. The mRNA for the injury/stress-hub gene Activating Transcription Factor 3 (ATF3) was upregulated and peaked within 4 DPI, after which levels declined but remained significantly elevated out to 28 DPI, a time when the initial incision appears healed and tissue-inflammation largely resolved. Accordingly, stereological image analysis indicated that some neurons expressed ATF3 only transiently (mostly medium-large neurons), while in others it was sustained (mostly small neurons), suggesting cell-type-specific responses. In retrogradely-traced ATF3-expressing neurons, Calcium/calmodulin-dependent protein kinase type IV (CAMK4) protein levels and isolectin-B4 (IB4)-binding were suppressed whereas Growth Associated Protein-43 (GAP-43) and Neuropeptide Y (NPY) protein levels were enhanced. Electrophysiological recordings from DiI-traced sensory neurons 28 DPI showed a significant sensitization limited to ATF3-expressing neurons. Thus, ATF3 expression is revealed as a strong predictor of single cells displaying enduring pain-related electrophysiological properties. The cellular injury/stress response induced in sensory neurons by tissue damage and indicated by ATF3 expression is positioned to contribute to pain which can occur after tissue damage.
Asunto(s)
Nocicepción/fisiología , Dolor Nociceptivo/etiología , Células Receptoras Sensoriales/metabolismo , Enfermedades de la Piel/complicaciones , Enfermedades de la Piel/patología , Factor de Transcripción 3/metabolismo , Regulación hacia Arriba/fisiología , Animales , Proteína Quinasa Tipo 4 Dependiente de Calcio Calmodulina/metabolismo , Modelos Animales de Enfermedad , Femenino , Lateralidad Funcional , Proteína GAP-43/metabolismo , Ganglios Espinales/patología , Glicoproteínas/metabolismo , Lectinas/metabolismo , Neuropéptido Y/metabolismo , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Factor de Transcripción 3/genética , VersicanosRESUMEN
The protein inhibitor of activated STAT1 (PIAS1) plays important roles in regulating virus-induced chronic hepatitis, but the interaction between hepatitis B virus (HBV) and hPIAS1 is not clear. Our aim was to verify if HBV encoding proteins enhance the transcription of hPIAS1 and which cis-elements and transcription factors were involved in the mechanism. In order to do, so a series of molecular biological methods, along with functional and histological studies, were performed. We found that the HBV surface protein (HBs) enhanced hPIAS1 transcription through the activities of TAL1, E47, myogenin (MYOG), and NFI, dependent on the activation of p38MAPK and ERK signaling pathways in vitro, which might contribute to the ineffectiveness of treatment in CHB patients. Furthermore, liver samples from patients with high HBsAg levels and HBV DNA displayed increased hPIAS1 expression and high levels of TAL1, E47, MYOG, and NFI, compared to those patients with low HBsAg levels and HBV DNA, and healthy controls. These findings suggest that the HBs protein-induced hPIAS1 transcription requires TAL1, E47, MYOG, NFI, and MAPK signal pathways. It provides new potential targets for antiviral therapeutic strategies for controlling HBV-associated diseases.
Asunto(s)
Virus de la Hepatitis B/metabolismo , Sistema de Señalización de MAP Quinasas , Proteínas Nucleares/metabolismo , Proteínas Inhibidoras de STAT Activados/genética , Transcripción Genética , Proteínas del Envoltorio Viral/metabolismo , Adulto , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/deficiencia , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Células CHO , Cricetinae , Cricetulus , Femenino , Regulación de la Expresión Génica , Técnicas de Silenciamiento del Gen , Células Hep G2 , Antígenos de Superficie de la Hepatitis B/metabolismo , Virus de la Hepatitis B/fisiología , Humanos , Masculino , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Miogenina/genética , Miogenina/metabolismo , Factores de Transcripción NFI/deficiencia , Factores de Transcripción NFI/genética , Factores de Transcripción NFI/metabolismo , Proteínas Nucleares/deficiencia , Proteínas Nucleares/genética , Fosforilación , Regiones Promotoras Genéticas/genética , Proteínas Proto-Oncogénicas/deficiencia , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas/metabolismo , Proteína 1 de la Leucemia Linfocítica T Aguda , Factor de Transcripción 3/deficiencia , Factor de Transcripción 3/genética , Factor de Transcripción 3/metabolismoRESUMEN
The TWIST1 embryonic transcription factor displays biphasic functions during the course of carcinogenesis. It facilitates the escape of cells from oncogene-induced fail-safe programs (senescence, apoptosis) and their consequent neoplastic transformation. Additionally, it promotes the epithelial-to-mesenchymal transition and the initiation of the metastatic spread of cancer cells. Interestingly, cancer cells recurrently remain dependent on TWIST1 for their survival and/or proliferation, making TWIST1 their Achilles' heel. TWIST1 has been reported to form either homodimeric or heterodimeric complexes mainly in association with the E bHLH class I proteins. These complexes display distinct, sometimes even antagonistic, functions during development and unequal prometastatic functions in prostate cancer cells. Using a tethered dimer strategy, we successively assessed the ability of TWIST1 dimers to cooperate with an activated version of RAS in human mammary epithelial cell transformation, to provide mice with the ability to spontaneously develop breast tumors, and lastly to maintain a senescence program at a latent state in several breast cancer cell lines. We demonstrate that the TWIST1-E12 complex, unlike the homodimer, is an oncogenic form of TWIST1 in mammary epithelial cells and that efficient binding of both partners is a prerequisite for its activity. The detection of the heterodimer in human premalignant lesions by a proximity ligation assay, at a stage preceding the initiation of the metastatic cascade, is coherent with such an oncogenic function. TWIST1-E protein heterodimeric complexes may thus constitute the main active forms of TWIST1 with regard to senescence inhibition over the time course of breast tumorigenesis.
Asunto(s)
Transformación Celular Neoplásica/metabolismo , Células Epiteliales/metabolismo , Glándulas Mamarias Humanas/metabolismo , Factor de Transcripción 3/metabolismo , Proteína 1 Relacionada con Twist/metabolismo , Línea Celular Tumoral , Proliferación Celular , Senescencia Celular/genética , Células Epiteliales/patología , Expresión Génica , Humanos , Glándulas Mamarias Humanas/patología , Mutación , Lesiones Precancerosas/genética , Lesiones Precancerosas/metabolismo , Lesiones Precancerosas/patología , Unión Proteica , Multimerización de Proteína , Factor de Transcripción 3/genética , Proteína 1 Relacionada con Twist/genéticaRESUMEN
The Inhibitor of DNA Binding (Id) proteins play a crucial role in regulating hematopoiesis and are known to interact with E proteins and the bHLH family of transcription factors. Current efforts seek to elucidate the individual roles of Id members in regulating hematopoietic development and specification. However, the nature of their functional redundancies remains elusive since ablation of multiple Id genes is embryonically lethal. We developed a model to test this compensation in the adult. We report that global Id3 ablation with Tie2Cre-mediated conditional ablation of Id1 in both hematopoietic and endothelial cells (Id cDKO) extends viability to 1 year but leads to multi-lineage hematopoietic defects including the emergence of anemia associated with defective erythroid development, a novel phenotype unreported in prior single Id knockout studies. We observe decreased cell counts in the bone marrow and splenomegaly to dimensions beyond what is seen in single Id knockout models. Transcriptional dysregulation of hematopoietic regulators observed in bone marrow cells is also magnified in the spleen. E47 protein levels were elevated in Id cDKO bone marrow cell isolates, but decreased in the erythroid lineage. Chromatin immunoprecipitation (ChIP) studies reveal increased occupancy of E47 and GATA1 at the promoter regions of ß-globin and E2A. Bone marrow transplantation studies highlight the importance of intrinsic Id signals in maintaining hematopoietic homeostasis while revealing a strong extrinsic influence in the development of anemia. Together, these findings demonstrate that loss of Id compensation leads to dysregulation of the hematopoietic transcriptional network and multiple defects in erythropoietic development in adult mice.
Asunto(s)
Anemia , Eritropoyesis/genética , Eliminación de Gen , Células Madre Hematopoyéticas/metabolismo , Proteína 1 Inhibidora de la Diferenciación/deficiencia , Proteínas Inhibidoras de la Diferenciación/deficiencia , Anemia/genética , Anemia/metabolismo , Anemia/patología , Animales , Factor de Transcripción GATA1/genética , Factor de Transcripción GATA1/metabolismo , Células Madre Hematopoyéticas/patología , Células Endoteliales de la Vena Umbilical Humana , Humanos , Proteína 1 Inhibidora de la Diferenciación/metabolismo , Proteínas Inhibidoras de la Diferenciación/metabolismo , Ratones , Ratones Noqueados , Factor de Transcripción 3/genética , Factor de Transcripción 3/metabolismoRESUMEN
Antagonistic interactions between transcription factors contribute to cell fate decisions made by multipotent hematopoietic progenitor cells. Concentration of the transcription factor PU.1 affects myeloid/lymphoid development with high levels of PU.1 directing myeloid cell fate acquisition at the expense of B cell differentiation. High levels of PU.1 may be required for myelopoiesis in order to overcome inhibition of its activity by transcription factors that promote B cell development. The B cell transcription factors, E2A and EBF, are necessary for commitment of multipotential progenitors and lymphoid primed multipotential progenitors to lymphocytes. In this report we hypothesized that factors required for early B cell commitment would bind to PU.1 and antagonize its ability to induce myeloid differentiation. We investigated whether E2A and/or EBF associate with PU.1. We observed that the E2A component, E47, but not EBF, directly binds to PU.1. Additionally E47 represses PU.1-dependent transactivation of the MCSFR promoter through antagonizing PU.1's ability to bind to DNA. Exogenous E47 expression in hematopoietic cells inhibits myeloid differentiation. Our data suggest that E2A antagonism of PU.1 activity contributes to its ability to commit multipotential hematopoietic progenitors to the lymphoid lineages.
Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Diferenciación Celular/genética , Proteínas de Unión al ADN/metabolismo , Células Madre Hematopoyéticas/metabolismo , Proteínas Proto-Oncogénicas/biosíntesis , Transactivadores/biosíntesis , Linfocitos B/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Línea Celular , Linaje de la Célula/genética , Proteínas de Unión al ADN/genética , Regulación del Desarrollo de la Expresión Génica , Factor Estimulante de Colonias de Macrófagos/genética , Células Mieloides/metabolismo , Unión Proteica/genética , Proteínas Proto-Oncogénicas/genética , Transactivadores/genética , Transactivadores/metabolismo , Factor de Transcripción 3/genética , Factor de Transcripción 3/metabolismoRESUMEN
Adult neural stem/precursor cells (NSPCs) of the subventricular zone (SVZ) are an endogenous source for neuronal replacement in CNS disease. However, adult neurogenesis is compromised after brain injury in favor of a glial cell fate, which is mainly attributed to changes in the NSPC environment. Yet, it is unknown how this unfavorable extracellular environment translates into a transcriptional program altering NSPC differentiation. Here, we show that genetic depletion of the transcriptional regulator Id3 decreased the number of astrocytes generated from SVZ-derived adult NSPCs in the cortical lesion area after traumatic brain injury. Cortical brain injury resulted in rapid BMP-2 and Id3 up-regulation in the SVZ stem cell niche. Id3(-/-) adult NSPCs failed to differentiate into BMP-2-induced astrocytes, while NSPCs deficient for the Id3-controlled transcription factor E47 readily differentiated into astrocytes in the absence of BMP-2. Mechanistically, E47 repressed the expression of several astrocyte-specific genes in adult NSPCs. These results identify Id3 as the BMP-2-induced transcriptional regulator, promoting adult NSPC differentiation into astrocytes upon CNS injury and reveal a molecular link between environmental changes and NSPC differentiation in the CNS after injury.