Polymorphism of the transcription factor 7-like 2 Gene (TCF7L2) interacts with obesity on type-2 diabetes in the PREDIMED Study emphasizing the heterogeneity of genetic variants in type-2 diabetes risk prediction: time for...

USDA-ARS?s Scientific Manuscript database

Nutrigenetic studies analyzing gene-diet interactions of the TCF7L2-rs7903146 C > T polymorphism on type-2 diabetes (T2D) have shown controversial results. A reason contributing to this may be the additional modulation by obesity. Moreover, TCF7L2-rs7903146 is one of the most influential variants in...

Transcription-dependent radial distribution of TCF7L2 regulated genes in chromosome territories.

PubMed

Torabi, Keyvan; Wangsa, Darawalee; Ponsa, Immaculada; Brown, Markus; Bosch, Anna; Vila-Casadesús, Maria; Karpova, Tatiana S; Calvo, Maria; Castells, Antoni; Miró, Rosa; Ried, Thomas; Camps, Jordi

2017-10-01

Human chromosomes occupy distinct territories in the interphase nucleus. Such chromosome territories (CTs) are positioned according to gene density. Gene-rich CTs are generally located in the center of the nucleus, while gene-poor CTs are positioned more towards the nuclear periphery. However, the association between gene expression levels and the radial positioning of genes within the CT is still under debate. In the present study, we performed three-dimensional fluorescence in situ hybridization experiments in the colorectal cancer cell lines DLD-1 and LoVo using whole chromosome painting probes for chromosomes 8 and 11 and BAC clones targeting four genes with different expression levels assessed by gene expression arrays and RT-PCR. Our results confirmed that the two over-expressed genes, MYC on chromosome 8 and CCND1 on chromosome 11, are located significantly further away from the center of the CT compared to under-expressed genes on the same chromosomes, i.e., DLC1 and SCN3B. When CCND1 expression was reduced after silencing the major transcription factor of the WNT/β-catenin signaling pathway, TCF7L2, the gene was repositioned and mostly detected in the interior of the CT. Thus, we suggest a non-random distribution in which over-expressed genes are located more towards the periphery of the respective CTs.

TCF7L2 polymorphisms and the risk of schizophrenia in the Chinese Han population

PubMed Central

Liu, Lijun; Li, Jingjie; Yan, Mengdan; Li, Jing; Chen, Junyu; Zhang, Yi; Zhu, Xikai; Wang, Li; Kang, Longli; Yuan, Dongya; Jin, Tianbo

2017-01-01

Single nucleotide polymorphisms (SNPs) in TCF7L2 (Transcription Factor 7-Like 2) reportedly affect susceptibility to schizophrenia (SCZ). We examined the association between TCF7L2 polymorphisms and SCZ susceptibility in a Chinese Han population. Six SNPs were genotyped in 499 SCZ patients and 500 healthy individuals, after which their associations with SCZ were evaluated using the Chi-squared test and genetic model analyses. We observed that the allele A of rs12573128 is associated with an increased SCZ risk (odds ratio [OR] = 1.33, 95% confidence interval [CI]: 1.08-1.63, P = 0.006, adjusted P = 0.030). The AA genotype of rs12573128 was associated with a higher SCZ risk than the GG genotype, before and after adjustment for sex and age (adjusted OR = 2.97, 95% CI: 1.49-5.92, P = 0.002). In addition, SNP rs12573128 was associated with 1.47-fold, 2.64-fold and 1.50-fold increases in SCZ risk of in dominant, recessive and additive model, respectively (adjusted OR = 1.47, 95% CI = 1.09-1.99, P = 0.012; Bonferroni adjusted P = 0.030). adjusted OR = 2.64, 95% CI = 1.34-5.18, P = 0.005 and adjusted OR = 1.50, 95% CI = 1.17-1.93, P = 0.002, respectively). These results suggest rs12573128 is significantly associated with an increased risk of SCZ in the Chinese Han population. PMID:28404897

Polymorphism of the Transcription Factor 7-Like 2 Gene (TCF7L2) Interacts with Obesity on Type-2 Diabetes in the PREDIMED Study Emphasizing the Heterogeneity of Genetic Variants in Type-2 Diabetes Risk Prediction: Time for Obesity-Specific Genetic Risk Scores.

PubMed

Corella, Dolores; Coltell, Oscar; Sorlí, Jose V; Estruch, Ramón; Quiles, Laura; Martínez-González, Miguel Ángel; Salas-Salvadó, Jordi; Castañer, Olga; Arós, Fernando; Ortega-Calvo, Manuel; Serra-Majem, Lluís; Gómez-Gracia, Enrique; Portolés, Olga; Fiol, Miquel; Díez Espino, Javier; Basora, Josep; Fitó, Montserrat; Ros, Emilio; Ordovás, José M

2016-12-06

Nutrigenetic studies analyzing gene-diet interactions of the TCF7L2-rs7903146 C > T polymorphism on type-2 diabetes (T2D) have shown controversial results. A reason contributing to this may be the additional modulation by obesity. Moreover, TCF7L2-rs7903146 is one of the most influential variants in T2D-genetic risk scores (GRS). Therefore, to increase the predictive value (PV) of GRS it is necessary to first see whether the included polymorphisms have heterogeneous effects. We comprehensively investigated gene-obesity interactions between the TCF7L2-rs7903146 C > T polymorphism on T2D (prevalence and incidence) and analyzed other T2D-polymorphisms in a sub-sample. We studied 7018 PREDIMED participants at baseline and longitudinally (8.7 years maximum follow-up). Obesity significantly interacted with the TCF7L2-rs7903146 on T2D prevalence, associations being greater in non-obese subjects. Accordingly, we prospectively observed in non-T2D subjects ( n = 3607) that its association with T2D incidence was stronger in non-obese (HR: 1.81; 95% CI: 1.13-2.92, p = 0.013 for TT versus CC) than in obese subjects (HR: 1.01; 95% CI: 0.61-1.66; p = 0.979; p -interaction = 0.048). Accordingly, TCF7L2-PV was higher in non-obese subjects. Additionally, we created obesity-specific GRS with ten T2D-polymorphisms and demonstrated for the first time their higher strata-specific PV. In conclusion, we provide strong evidence supporting the need for considering obesity when analyzing the TCF7L2 effects and propose the use of obesity-specific GRS for T2D.

Polymorphisms in FTO and TCF7L2 genes of Euro-Brazilian women with gestational diabetes.

PubMed

de Melo, Sandra Fabrico; Frigeri, Henrique Ravanhol; dos Santos-Weiss, Izabella Castilhos Ribeiro; Réa, Rosângela Roginski; de Souza, Emanuel Maltempi; Alberton, Dayane; Gomes de Moraes Rego, Fabiane; Picheth, Geraldo

2015-11-01

To investigate the association between fat mass and obesity-associated (FTO) gene polymorphisms rs8050136C>A and rs9939609T>A, and transcription factor 7-like 2 (TCF7L2) gene polymorphisms rs12255372G>T and rs7903146C>T, in a sample group of pregnant Euro-Brazilian women with or without gestational diabetes mellitus (GDM). Subjects were classified as either healthy pregnant control (n=200) or GDM (n=200) according to the 2010 criteria of the American Diabetes Association. The polymorphisms were genotyped using fluorescent probes (TaqMan®). All groups were in the Hardy-Weinberg equilibrium. The genotype and allele frequencies of the examined polymorphisms did not exhibit significant difference (P>0.05) between the groups. In the healthy and GDM pregnant women groups, the A-allele frequencies (95% CI) of FTO polymorphisms rs8050136 and rs9939609 were 39% (34-44%); 38% (33-43%) and 40% (35-45%); 41% (36-46%), respectively; and the T-allele frequencies of TCF7L2 polymorphisms rs12255372 and rs7903146 were 30% (26-35%), 32% (27-37%) and 29% (25-34%), 36% (31-41%), respectively. The examined polymorphisms were not associated with GDM in the Euro-Brazilian population studied. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Silencing of the Wnt transcription factor TCF4 sensitizes colorectal cancer cells to (chemo-) radiotherapy

PubMed Central

Kendziorra, Emil; Ahlborn, Kerstin; Spitzner, Melanie; Rave-Fränk, Margret; Emons, Georg; Gaedcke, Jochen; Kramer, Frank; Wolff, Hendrik A.; Becker, Heinz; Beissbarth, Tim; Ebner, Reinhard; Ghadimi, B.Michael; Pukrop, Tobias; Ried, Thomas; Grade, Marian

2011-01-01

A considerable percentage of rectal cancers are resistant to standard preoperative chemoradiotherapy. Because patients with a priori-resistant tumors do not benefit from multimodal treatment, understanding and overcoming this resistance remains of utmost clinical importance. We recently reported overexpression of the Wnt transcription factor TCF4, also known as TCF7L2, in rectal cancers that were resistant to 5-fluorouracil-based chemoradiotherapy. Because Wnt signaling has not been associated with treatment response, we aimed to investigate whether TCF4 mediates chemoradioresistance. RNA interference-mediated silencing of TCF4 was employed in three colorectal cancer (CRC) cell lines, and sensitivity to (chemo-) radiotherapy was assessed using a standard colony formation assay. Silencing of TCF4 caused a significant sensitization of CRC cells to clinically relevant doses of X-rays. This effect was restricted to tumor cells with high T cell factor (TCF) reporter activity, presumably in a β-catenin-independent manner. Radiosensitization was the consequence of (i) a transcriptional deregulation of Wnt/TCF4 target genes, (ii) a silencing-induced G2/M phase arrest, (iii) an impaired ability to adequately halt cell cycle progression after radiation and (iv) a compromised DNA double strand break repair as assessed by γH2AX staining. Taken together, our results indicate a novel mechanism through which the Wnt transcription factor TCF4 mediates chemoradioresistance. Moreover, they suggest that TCF4 is a promising molecular target to sensitize resistant tumor cells to (chemo-) radiotherapy. PMID:21983179

TCF7L2 polymorphism associates with new-onset diabetes after transplantation.

PubMed

Ghisdal, Lidia; Baron, Christophe; Le Meur, Yannick; Lionet, Arnaud; Halimi, Jean-Michel; Rerolle, Jean-Philippe; Glowacki, François; Lebranchu, Yvon; Drouet, Mireille; Noël, Christian; El Housni, Hakim; Cochaux, Pascale; Wissing, Karl Martin; Abramowicz, Daniel; Abramowicz, Marc

2009-11-01

New-onset diabetes after transplantation (NODAT) is a serious and frequent complication in transplant recipients. Whether NODAT shares the same susceptibility genes as type 2 diabetes is unknown. In this multicenter study, we genotyped 1076 white patients without diabetes at transplantation for 11 polymorphisms that associate with type 2 diabetes. We defined NODAT as a fasting plasma glucose > or =126 mg/dl on at least two occasions or de novo hypoglycemic therapy. We compared clinical and genetic factors between patients who developed NODAT within 6 mo of transplantation (n = 118; incidence 11%) and patients without diabetes (n = 958). In multivariate analysis, NODAT significantly associated with the following characteristics: TCF7L2 polymorphism (odds ratio [OR] 1.60 per each T allele; P = 0.002), age (OR 1.03 per year; P < 0.001), body mass index at transplantation (OR 1.09 per unit; P < 0.001), tacrolimus use (OR 2.26; P < 0.001), and the occurrence of a corticoid-treated acute rejection episode (OR 2.78; P < 0.001). In summary, our data show that the TCF7L2 rs7903146 polymorphism, a known risk factor for type 2 diabetes in the general population, also associates with NODAT.

Type 2 diabetes mellitus susceptibility gene TCF7L2 is strongly associated with hyperglycemia in the Saudi Arabia Population of the eastern province of Saudi Arabia.

PubMed

Acharya, S; Al-Elq, A; Al-Nafaie, A; Muzaheed, M; Al-Ali, A

2015-08-01

We studied the association of single nucleotide polymorphisms (SNPs) rs7903146, rs12255372 and rs4506565 in type 2 diabetes mellitus (T2DM) susceptibility gene, transcription factor 7 like 2 (TCF7L2) with T2DM among the population of the Eastern Province of Saudi Arabia. In a case-control study, blood samples were collected from 359 T2DM patients and 351 age and sex-matched normoglycemic controls. Genotyping was done by allele specific PCR assay. Our results revealed a strong association between risk T alleles in variants rs12255372 (OR: G/T=1.4233; T/T=2.0395) and rs4506565 (OR: A/T=1.6066; T/T=3.1301) and T2DM among the Saudi population of the Eastern Province of Saudi Arabia. This is the first time that this association has been identified in a Saudi population. However, a common variant, rs7903146, often found to be associated with T2DM in other populations failed to demonstrate any association to T2DM with the present population. These data further strengthens the hypothesis that Saudi populations might carry a distinct risk allele in T2DM susceptibility gene TCF7L2. The present results confirm that rs12255372 and rs4506565 variants of TCF7L2 show an association, but not rs7903146, with T2DM for the Saudi population of the Eastern Province of Saudi Arabia.

The T-Allele of TCF7L2 rs7903146 Associates With a Reduced Compensation of Insulin Secretion for Insulin Resistance Induced by 9 Days of Bed Rest

PubMed Central

Alibegovic, Amra C.; Sonne, Mette P.; Højbjerre, Lise; Hansen, Torben; Pedersen, Oluf; van Hall, Gerrit; Holst, Jens J.; Stallknecht, Bente; Dela, Flemming; Vaag, Allan

2010-01-01

OBJECTIVE The aim of this study was to determine whether the type 2 diabetes–associated T-allele of transcription factor 7-like 2 (TCF7L2) rs7903146 associates with impaired insulin secretion to compensate for insulin resistance induced by bed rest. RESEARCH DESIGN AND METHODS A total of 38 healthy young Caucasian men were studied before and after bed rest using the hyperinsulinemic-euglycemic clamp technique combined with indirect calorimetry preceded by an intravenous glucose tolerance test. The TCF7L2 rs7903146 was genotyped using allelic discrimination performed with an ABI 7900 system. The genetic analyses were done assuming a dominant model of inheritance. RESULTS The first-phase insulin response (FPIR) was significantly lower in carriers of the T-allele compared with carriers of the CC genotype before bed rest, with and without correction for insulin resistance. The incremental rise of FPIR in response to insulin resistance induced by bed rest was lower in carriers of the T-allele (P < 0.001). Fasting plasma glucagon levels were significantly lower in carriers of the T-allele before and after bed rest. While carriers of the CC genotype developed increased hepatic insulin resistance, the TCF7L2 rs7903146 did not influence peripheral insulin action or the rate of lipolysis before or after bed rest. CONCLUSIONS Healthy carriers of the T-allele of TCF7L2 rs7903146 exhibit a diminished increase of insulin secretion in response to intravenous glucose to compensate for insulin resistance as induced by bed rest. Reduced paracrine glucagon stimulation may contribute to the impairment of β-cell function in the carriers TCF7L2 rs7903146 T-allele associated with increased risk of type 2 diabetes. PMID:20107109

TCF7L2 polymorphism, weight loss and proinsulin:insulin ratio in the diabetes prevention program.

PubMed

McCaffery, Jeanne M; Jablonski, Kathleen A; Franks, Paul W; Dagogo-Jack, Sam; Wing, Rena R; Knowler, William C; Delahanty, Linda; Dabelea, Dana; Hamman, Richard; Shuldiner, Alan R; Florez, Jose C

2011-01-01

TCF7L2 variants have been associated with type 2 diabetes, body mass index (BMI), and deficits in proinsulin processing and insulin secretion. Here we sought to test whether these effects were apparent in high-risk individuals and modify treatment responses. We examined the potential role of the TCF7L2 rs7903146 variant in predicting resistance to weight loss or a lack of improvement of proinsulin processing during 2.5-years of follow-up participants (N = 2,994) from the Diabetes Prevention Program (DPP), a randomized controlled trial designed to prevent or delay diabetes in high-risk adults. We observed no difference in the degree of weight loss by rs7903146 genotypes. However, the T allele (conferring higher risk of diabetes) at rs7903146 was associated with higher fasting proinsulin at baseline (P<0.001), higher baseline proinsulin:insulin ratio (p<0.0001) and increased proinsulin:insulin ratio over a median of 2.5 years of follow-up (P = 0.003). Effects were comparable across treatment arms. The combination of a lack of impact of the TCF7L2 genotypes on the ability to lose weight, but the presence of a consistent effect on the proinsulin:insulin ratio over the course of DPP, suggests that high-risk genotype carriers at this locus can successfully lose weight to counter diabetes risk despite persistent deficits in insulin production.

Mediterranean Diet Reduces the Adverse Effect of the TCF7L2-rs7903146 Polymorphism on Cardiovascular Risk Factors and Stroke Incidence

PubMed Central

Corella, Dolores; Carrasco, Paula; Sorlí, Jose V.; Estruch, Ramón; Rico-Sanz, Jesús; Martínez-González, Miguel Ángel; Salas-Salvadó, Jordi; Covas, M. Isabel; Coltell, Oscar; Arós, Fernando; Lapetra, José; Serra-Majem, Lluís; Ruiz-Gutiérrez, Valentina; Warnberg, Julia; Fiol, Miquel; Pintó, Xavier; Ortega-Azorín, Carolina; Muñoz, Miguel Ángel; Martínez, J. Alfredo; Gómez-Gracia, Enrique; González, José I.; Ros, Emilio; Ordovás, José M.

2013-01-01

OBJECTIVE Transcription factor 7-like 2 (TCF7L2) polymorphisms are strongly associated with type 2 diabetes, but controversially with plasma lipids and cardiovascular disease. Interactions of the Mediterranean diet (MedDiet) on these associations are unknown. We investigated whether the TCF7L2-rs7903146 (C>T) polymorphism associations with type 2 diabetes, glucose, lipids, and cardiovascular disease incidence were modulated by MedDiet. RESEARCH DESIGN AND METHODS A randomized trial (two MedDiet intervention groups and a control group) with 7,018 participants in the PREvención con DIetaMEDiterránea study was undertaken and major cardiovascular events assessed. Data were analyzed at baseline and after a median follow-up of 4.8 years. Multivariable-adjusted Cox regression was used to estimate hazard ratios (HRs) for cardiovascular events. RESULTS The TCF7L2-rs7903146 polymorphism was associated with type 2 diabetes (odds ratio 1.87 [95% CI 1.62–2.17] for TT compared with CC). MedDiet interacted significantly with rs7903146 on fasting glucose at baseline (P interaction = 0.004). When adherence to the MedDiet was low, TT had higher fasting glucose concentrations (132.3 ± 3.5 mg/dL) than CC+CT (127.3 ± 3.2 mg/dL) individuals (P = 0.001). Nevertheless, when adherence was high, this increase was not observed (P = 0.605). This modulation was also detected for total cholesterol, LDL cholesterol, and triglycerides (P interaction < 0.05 for all). Likewise, in the randomized trial, TT subjects had a higher stroke incidence in the control group (adjusted HR 2.91 [95% CI 1.36–6.19]; P = 0.006 compared with CC), whereas dietary intervention with MedDiet reduced stroke incidence in TT homozygotes (adjusted HR 0.96 [95% CI 0.49–1.87]; P = 0.892 for TT compared with CC). CONCLUSIONS Our novel results suggest that MedDiet may not only reduce increased fasting glucose and lipids in TT individuals, but also stroke incidence. PMID:23942586

Glucose Metabolism in High-Risk Subjects for Type 2 Diabetes Carrying the rs7903146 TCF7L2 Gene Variant.

PubMed

Daniele, Giuseppe; Gaggini, Melania; Comassi, Mario; Bianchi, Cristina; Basta, Giuseppina; Dardano, Angela; Miccoli, Roberto; Mari, Andrea; Gastaldelli, Amalia; Del Prato, Stefano

2015-08-01

The mechanisms responsible for contribution of variants in the gene TFC7L2 to the risk for type 2 diabetes (T2DM) remains far from being completely understood, and available studies have generated nonunivocal results. We investigated the postprandial glucose metabolism in subjects at risk for T2DM carrying the TCF7L2 risk allele. Twenty-three subjects carrying the risk-conferring TCF7L2 genotypes (11 TT and 12 CT at rs7901346) and 13 subjects with wild-type genotype (CC) underwent a standard mixed-meal test (MMT) in combination with stable isotope tracers. We evaluated endogenous and exogenous glucose fluxes and hormonal responses. Fasting plasma glucose, insulin, C-peptide, glycated hemoglobin, endogenous glucose production, and plasma glucose clearance were similar in the three groups, whereas plasma glucagon levels were lower in both CT and TT than in CC (64 ± 20, 63 ± 18 and 90 ± 29 pg/mL, respectively; both P = .01). In response to the MMT, TT subjects had lower plasma glucose levels than CC subjects [mean area under the time-concentration curve (AUC) 6.1 ± 3.9 vs 7.1 ± 12.0 mmol/L, P = .04] and lower insulin secretion rate (mean AUC 385 ± 95 vs 530 ± 159 pmol/m(2) · min, P = .02). Initial (0-60 min) rate of appearance (Ra) of oral glucose was lower in TT compared with CT/CC (AUC 2.7 ± 1.1 vs 3.8 ± 1.2 μmol/kg · min, P = .02) with no difference among the three groups in endogenous glucose production. The AUC0-60min for Ra of exogenous glucose (Raex) was positively correlated with the plasma glucose AUC0-60min. Total Raex AUC0-120min was correlated with total AUC0-120min of plasma glucose (r = 0.45, P < .01). Plasma glucagon-like peptide-1 and glucose-dependent insulinotropic peptide levels in response to the MMT were not affected by genotype. In subjects at risk for T2DM, the TCF7L2 polymorphisms were associated with reduced Raex into systemic circulation, causing reduced postprandial blood glucose increase and, in turn, lower insulin secretion

Association of rs7903146, rs12255372, and rs290487 polymorphisms in TCF7L2 gene with type 2 diabetes in an Iranian Kurdish ethnic group.

PubMed

Shokouhi, Shabnam; Delpisheh, Ali; Haghani, Karimeh; Mahdizadeh, Mohsen; Bakhtiyari, Salar

2014-01-01

Single nucleotide polymorphisms (SNPs) within the transcription factor 7-like 2 (TCF7L2) gene are well known risk variants for type 2 diabetes mellitus (T2DM). The association between TCF7L2 SNPs and T2DM has been investigated in several studies, but the results are controversial. In this study, we investigated whether the rs7903146, rs12255372, and rs290487 polymorphisms of TCF7L2 are associated with T2DM per se or metabolic traits related to this disease in a Kurdish ethnic group of Iran. In all, 173 patients with T2DM and 173 normoglycemic subjects were included in this study. All subjects were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Genotypic and allelic frequencies were then analyzed in each group. Serum lipids, fasting glucose, fasting serum insulin, HOMA-IR, and HbA1c levels were determined by conventional methods. T-allele and genotype frequencies of rs7903146, rs12255372, and rs290487 were significantly different between T2DM and control subjects. The CT genotype (OR = 1.98, p = 0.008), TT genotype (OR = 3.54, p = 0.024), and the dominant model (OR = 2.16, p = 0.002) of rs7903146 were associated with T2DM. The GT genotype (OR = 2.23, p = 0.005), TT genotype (OR = 4.25, p = 0.046), and the dominant model (OR = 2.2, p = 0.001) of rs12255372 gave a higher risk for T2DM. The carriers of CT genotype of rs290487 showed a significantly increased risk for T2DM (OR = 2.24, p = 0.003). Similarly, the dominant model of this SNP was found to be significantly associated with T2DM (OR = 2.25, p = 0.002). The control subjects carrying the T-allele of rs7903146 had higher levels of total cholesterol (CC; 4.52 +/- 1.03 vs. CT + TT; 5.00 +/- 1.2 mmol/L, p = 0.009) than those with CC genotype. Normoglycemic subjects carrying GT + TT genotypes of rs12255372 had a significantly higher WHR (GG; 0.90 +/- 0.059 vs. GT + TT; 0.93 +/- 0.07, p = 0.038) as compared with those with the GG genotype. The T-allele of rs12255372, rs

TCF7L2 gene polymorphisms do not predict susceptibility to diabetes in tropical calcific pancreatitis but may interact with SPINK1 and CTSB mutations in predicting diabetes.

PubMed

Mahurkar, Swapna; Bhaskar, Seema; Reddy, D Nageshwar; Prakash, Swami; Rao, G Venkat; Singh, Shivaram Prasad; Thomas, Varghese; Chandak, Giriraj Ratan

2008-08-16

Tropical calcific pancreatitis (TCP) is a type of chronic pancreatitis unique to developing countries in tropical regions and one of its important features is invariable progression to diabetes, a condition called fibro-calculous pancreatic diabetes (FCPD), but the nature of diabetes in TCP is controversial. We analysed the recently reported type 2 diabetes (T2D) associated polymorphisms in the TCF7L2 gene using a case-control approach, under the hypothesis that TCF7L2 variants should show similar association if diabetes in FCPD is similar to T2D. We also investigated the interaction between the TCF7L2 variants and N34S SPINK1 and L26V CTSB mutations, since they are strong predictors of risk for TCP. Two polymorphisms rs7903146 and rs12255372 in the TCF7L2 gene were analyzed by direct sequencing in 478 well-characterized TCP patients and 661 healthy controls of Dravidian and Indo-European ethnicities. Their association with TCP with diabetes (FCPD) and without diabetes was tested in both populations independently using chi-square test. Finally, a meta analysis was performed on all the cases and controls for assessing the overall significance irrespective of ethnicity. We dichotomized the whole cohort based on the presence or absence of N34S SPINK1 and L26V CTSB mutations and further subdivided them into TCP and FCPD patients and compared the distribution of TCF7L2 variants between them. The allelic and genotypic frequencies for both TCF7L2 polymorphisms, did not differ significantly between TCP patients and controls belonging to either of the ethnic groups or taken together. No statistically significant association of the SNPs was observed with TCP or FCPD or between carriers and non-carriers of N34S SPINK1 and L26V CTSB mutations. The minor allele frequency for rs7903146 was different between TCP and FCPD patients carrying the N34S SPINK1 variant but did not reach statistical significance (OR = 1.59, 95% CI = 0.93-2.70, P = 0.09), while, TCF7L2variant showed a

TCF7L2 rs7903146 polymorphism and diabetic nephropathy association is not independent of type 2 diabetes--a study in a south Indian population and meta-analysis.

PubMed

Hussain, Hajarah; Ramachandran, Vinu; Ravi, Samathmika; Sajan, Teena; Ehambaram, Kiruthiha; Gurramkonda, Venkatesh Babu; Ramanathan, Gnanasambandan; Bhaskar, Lakkakula Venkata

2014-01-01

Diabetic nephropathy (DN) is a chronic microangiopathic complication of both type 1 (T1DM) and type 2 diabetes mellitus (T2DM). The TCF7L2 gene has been reported to be associated with type 2 diabetes risk. We aimed to investigate the impact of TCF7L2 gene on the susceptibility of T2DM and DN in a south Indian population. Plus to evaluate the association of rs7903146 in the TCF7L2 gene with T2DM in the Indian population. The subjects recruited for this included 55 diabetic cases with diabetic nephropathy, 68 diabetic cases without nephropathy, and 82 non-diabetic healthy controls. Genomic DNA was isolated from blood and genotyping of TCF7L2 rs7903146 was performed by PCR-RFLP analysis. A literature survey was carried out into the effect of rs7903146 on genetic susceptibility to T2DM in Indian populations and we then performed a meta-analysis in order to evaluate its association with T2DM. Analysis of TCF7L2 rs7903146 in normal controls and diabetics with or without nephropathy demonstrated that the 'T' allele is associated with both diabetes (p = 0.049) and DN (p = 0.024), but this association is not independent of T2DM. Meta-analysis showed that the mutant allele and genotypes are associated with T2DM in Indian populations. In summary, a significant association exists between the 'T' allele and DN, but this association is not independent of T2DM. Pooled meta-analysis of studies on rs7903146 and T2DM confirmed that rs7903146 is significantly associated with susceptibility to T2DM in Indian populations.

Gestational diabetes mellitus is associated with TCF7L2 gene polymorphisms independent of HLA-DQB1*0602 genotypes and islet cell autoantibodies

PubMed Central

Papadopoulou, A.; Lynch, K. F.; Shaat, N.; Håkansson, R.; Ivarsson, S. A.; Berntorp, K.; Agardh, C. D.; Lernmark, Å

2011-01-01

Aims To test whether the TCF7L2 gene was associated with gestational diabetes, whether the association between TCF7L2 and gestational diabetes was independent of HLA-DQB1*0602 and islet cell autoantibodies, as well as maternal age, number of pregnancies, family history of diabetes and the HLA-DQB1 genotypes, and to test whether the distribution of HLA-DQB1 alleles was affected by country of birth. Methods We genotyped the rs7903146, rs12255372 and rs7901695 single nucleotide polymorphisms of the TCF7L2 gene in 826 mothers with gestational diabetes and in 1185 healthy control subjects in the Diabetes Prediction in Skåne Study. The mothers were also typed for HLA-DQB1 genotypes and tested for islet cell autoantibodies against GAD65, insulinoma-associated antigen-2 and insulin. Results The heterozygous genotypes CT, GT and TC of the rs7903146 (T is risk for Type 2 diabetes), rs12255372 (T is risk for Type 2 diabetes) and rs7901695 (C is risk for Type 2 diabetes), respectively, as well as the homozygous genotypes TT, TT and CC of the rs7903146, rs12255372 and rs7901695, respectively, were strongly associated with gestational diabetes (P < 0.0001). These associations remained statistically significant after adjusting for maternal age, number of pregnancies, family history of diabetes and HLA-DQ genotypes and were independent of the presence of islet cell autoantibodies. No interaction was observed between TCF7L2 and HLA-DQB1*0602, which was shown to be negatively associated with gestational diabetes in mothers born in Sweden (P = 0.010). Conclusions The TCF7L2 was associated with susceptibility for gestational diabetes independently of the presence of HLA-DQB1*0602 and islet cell autoantibodies and other factors such as maternal age, number of pregnancies, family history of diabetes and other HLA-DQ genotypes. The HLA-DQB1*0602 was negatively associated with gestational diabetes in mothers born in Sweden. PMID:21672010

[Risk of type 2 diabetes mellitus in the Kyrgyz population in the presence of ADIPOQ (G276T), KCNJ11 (Glu23Lys), TCF7L2 (IVS3C>T) gene polymorphisms].

PubMed

Isakova, Zh T; Talaibekova, E T; Asambaeva, D A; Kerimkulova, A S; Lunegova, O S; Aldasheva, N M; Aldashev, A A

To analyze the association of genotype combinations of the polymorphic markers G276T in the ADIPOQ gene, Glu23Lys in the KCNJ11 gene, and IVS3C>T in the TCF7L2 gene with the development of type 2 diabetes mellitus (T2DM) in the Kyrgyz population. The investigation enrolled 23 Kyrgyz people, of whom there were 114 patients with T2DM and 109 without T2DM (a control group). T2DM was diagnosed in accordance with the WHO criteria (1999). The genotypes of ADIPOQ (G276T), KCNJ11 (Glu23Lys), and TCF7L2 (IVS3C>T) gene polymorphisms were identified using the restriction fragment length polymorphism analysis. When typing at the polymorphic loci G276T in the ADIPOQ gene, Glu23Lys in the KCNJ11 gene, and IVS3C>T in the TCF7L2 gene, the development of T2DM in the Kyrgyz population was associated with the T allele (odds ratio (OR), 1.68; p=0.025), the heterozygous G276T genotype (OR 1,8; p=0.036) in the ADIPOQ gene; the 23Lys allele (OR, 1.62; p=0.019) in the KCNJ11 gene; a two-locus genotype combination in the genes ADIPOQ/KCNJ11: G276T/Glu23Lys (OR, 4.88; p=0.0013), G276G/Lys23Lys (OR, 4.65; p=0.019), G276T/Glu23Glu (OR, 3.10; p=0.022), a two-locus genotype combination in the genes ADIPOQ/TCF7L2: G276T/СС (OR, 1.97; p=0.04); two-locus genotype combinations in the genes KCNJ11/TCF7L2: Lys23Lys/CC (ОR, 2.65; p=0.042), Glu23Lys/CT (OR, 3.88; p=0.027); and a three-locus genotype combination in the genes ADIPOQ/KCNJ11/TCF7L2: G276T/Glu23Lys/CT (OR, 14.48; p=0.02). The development of T2DM in the Kyrgyz population is genetically determined by ADIPOQ (G276T) gene, KCNJ11 (Glu23Lys), and TCF7L (IVS3C>T) gene polymorphisms with the predisposing value of the T allele of the heterozygous G276T genotype in the ADIPOQ gene; the 23Lys allele in the KCNJ1 gene; as well as by genotype combinations in the genes ADIPOQ/KCNJ11 (G276T/Glu23Lys, G276G/Lys23Lys, G276T/Glu23Glu); ADIPOQ/TCF7L2 (G276T/SS); KCNJ11/TCF7L2 (Lys23Lys/CC, Glu23Lys/CT); ADIPOQ/KCNJ11/TCF7L2 (G276T/Glu23Lys /CT). The IVS3C

Gender-dependent associations of CDKN2A/2B, KCNJ11, POLI, SLC30A8, and TCF7L2 variants with type 2 diabetes in (North African) Tunisian Arabs.

PubMed

Turki, Amira; Al-Zaben, Ghadeer S; Khirallah, Moncef; Marmouch, Hela; Mahjoub, Touhami; Almawi, Wassim Y

2014-03-01

We investigated the impact of gender on T2DM association with confirmed susceptibility loci. CDKN2A/2B rs10811661, KCNJ11 rs5219, and TCF7L2 rs7903146 were associated with T2DM in females, while POLI rs488846 was associated with T2DM among males; the association of SLC30A8 rs13266634 and TCF7L2 rs4506565, rs12243326, and rs12255372 with T2DM was gender-independent. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Genome-wide association study of bipolar disorder accounting for effect of body mass index identifies a new risk allele in TCF7L2.

PubMed

Winham, S J; Cuellar-Barboza, A B; Oliveros, A; McElroy, S L; Crow, S; Colby, C; Choi, D-S; Chauhan, M; Frye, M; Biernacka, J M

2014-09-01

Bipolar disorder (BD) is associated with higher body mass index (BMI) and increased metabolic comorbidity. Considering the associated phenotypic traits in genetic studies of complex diseases, either by adjusting for covariates or by investigating interactions between genetic variants and covariates, may help to uncover the missing heritability. However, obesity-related traits have not been incorporated in prior genome-wide analyses of BD as covariates or potential interacting factors. To investigate the genetic factors underlying BD while considering BMI, we conducted genome-wide analyses using data from the Genetic Association Information Network BD study. We analyzed 729,454 genotyped single-nucleotide polymorphism (SNP) markers on 388 European-American BD cases and 1020 healthy controls with available data for maximum BMI. We performed genome-wide association analyses of the genetic effects while accounting for the effect of maximum BMI, and also evaluated SNP-BMI interactions. A joint test of main and interaction effects demonstrated significant evidence of association at the genome-wide level with rs12772424 in an intron of TCF7L2 (P=2.85E-8). This SNP exhibited interaction effects, indicating that the bipolar susceptibility risk of this SNP is dependent on BMI. TCF7L2 codes for the transcription factor TCF/LF, part of the Wnt canonical pathway, and is one of the strongest genetic risk variants for type 2 diabetes (T2D). This is consistent with BD pathophysiology, as the Wnt pathway has crucial implications in neurodevelopment, neurogenesis and neuroplasticity, and is involved in the mechanisms of action of BD and depression treatments. We hypothesize that genetic risk for BD is BMI dependent, possibly related to common genetic risk with T2D.

Transcription factor 7-like 1 is involved in hypothalamo–pituitary axis development in mice and humans

PubMed Central

Gaston-Massuet, Carles; McCabe, Mark J.; Scagliotti, Valeria; Young, Rodrigo M.; Carreno, Gabriela; Gregory, Louise C.; Jayakody, Sujatha A.; Pozzi, Sara; Gualtieri, Angelica; Basu, Basudha; Koniordou, Markela; Wu, Chun-I; Bancalari, Rodrigo E.; Rahikkala, Elisa; Veijola, Riitta; Lopponen, Tuija; Graziola, Federica; Turton, James; Signore, Massimo; Mousavy Gharavy, Seyedeh Neda; Charolidi, Nicoletta; Sokol, Sergei Y.; Merrill, Bradley J.; Dattani, Mehul T.; Martinez-Barbera, Juan Pedro

2016-01-01

Aberrant embryonic development of the hypothalamus and/or pituitary gland in humans results in congenital hypopituitarism (CH). Transcription factor 7-like 1 (TCF7L1), an important regulator of the WNT/β-catenin signaling pathway, is expressed in the developing forebrain and pituitary gland, but its role during hypothalamo–pituitary (HP) axis formation or involvement in human CH remains elusive. Using a conditional genetic approach in the mouse, we first demonstrate that TCF7L1 is required in the prospective hypothalamus to maintain normal expression of the hypothalamic signals involved in the induction and subsequent expansion of Rathke’s pouch progenitors. Next, we reveal that the function of TCF7L1 during HP axis development depends exclusively on the repressing activity of TCF7L1 and does not require its interaction with β-catenin. Finally, we report the identification of two independent missense variants in human TCF7L1, p.R92P and p.R400Q, in a cohort of patients with forebrain and/or pituitary defects. We demonstrate that these variants exhibit reduced repressing activity in vitro and in vivo relative to wild-type TCF7L1. Together, our data provide support for a conserved molecular function of TCF7L1 as a transcriptional repressor during HP axis development in mammals and identify variants in this transcription factor that are likely to contribute to the etiology of CH. PMID:26764381

Cumulative evidence for relationships between multiple variants in the VTI1A and TCF7L2 genes and cancer incidence.

PubMed

Zhang, Min; Tang, Mingshuang; Fang, Yanfei; Cui, Huijie; Chen, Siyu; Li, Junlong; Xiong, Hongyan; Lu, Jiachun; Gu, Dongqing; Zhang, Ben

2018-02-01

Genetic studies have linked the VTI1A-TCF7L2 region with risk of multiple cancers. However, findings from these studies were generally inconclusive. We aimed to provide a synopsis of current understanding of associations between variants in the VTI1A-TCF7L2 region and cancer susceptibility. We conducted a comprehensive research synopsis and meta-analysis to evaluate associations between 17 variants in this region and risk of seven cancers using data from 32 eligible articles totaling 224,656 cancer cases and 324,845 controls. We graded cumulative evidence of significant associations using Venice criteria and false-positive report probability tests. We also conducted analyses to evaluate potential function of these variants using data from the Encyclopedia of DNA Elements (ENCODE) Project. Eight variants showed a nominally significant association with risk of individual cancer (p < 0.05). Cumulative epidemiological evidence of an association was graded as strong for rs7903146 [odds ratio (OR) = 1.05, p = 4.13 × 10 -5 ] and rs7904519 (OR = 1.07, p = 2.02 × 10 -14 ) in breast cancer, rs11196172 (OR = 1.11, p = 2.22 × 10 -16 ), rs12241008 (OR = 1.13, p = 1.36 × 10 -10 ) and rs10506868 (OR = 1.10, p = 3.98 × 10 -9 ) in colorectal cancer, rs7086803 in lung cancer (OR = 1.30, p = 3.54 × 10 -18 ) and rs11196067 (OR = 1.18, p = 3.59 × 10 -13 ) in glioma, moderate for rs12255372 (OR = 1.12, p = 2.52 × 10 -4 ) in breast cancer and weak for rs7903146 (OR = 1.11, p = 0.007) in colorectal cancer. Data from ENCODE suggested that seven variants with strong evidence and other correlated variants might fall within putative functional regions. Collectively, our study provides summary evidence that common variants in the VTI1A and TCF7L2 genes are associated with risk of breast, colorectal, lung cancer and glioma and highlights the significant role of the VTI1A-TCF7L2 region in the pathogenesis of

Plasma metabolomics reveal alterations of sphingo- and glycerophospholipid levels in non-diabetic carriers of the transcription factor 7-like 2 polymorphism rs7903146.

PubMed

Then, Cornelia; Wahl, Simone; Kirchhofer, Anna; Grallert, Harald; Krug, Susanne; Kastenmüller, Gabi; Römisch-Margl, Werner; Claussnitzer, Melina; Illig, Thomas; Heier, Margit; Meisinger, Christa; Adamski, Jerzy; Thorand, Barbara; Huth, Cornelia; Peters, Annette; Prehn, Cornelia; Heukamp, Ina; Laumen, Helmut; Lechner, Andreas; Hauner, Hans; Seissler, Jochen

2013-01-01

Polymorphisms in the transcription factor 7-like 2 (TCF7L2) gene have been shown to display a powerful association with type 2 diabetes. The aim of the present study was to evaluate metabolic alterations in carriers of a common TCF7L2 risk variant. Seventeen non-diabetic subjects carrying the T risk allele at the rs7903146 TCF7L2 locus and 24 subjects carrying no risk allele were submitted to intravenous glucose tolerance test and euglycemic-hyperinsulinemic clamp. Plasma samples were analysed for concentrations of 163 metabolites through targeted mass spectrometry. TCF7L2 risk allele carriers had a reduced first-phase insulin response and normal insulin sensitivity. Under fasting conditions, carriers of TCF7L2 rs7903146 exhibited a non-significant increase of plasma sphingomyelins (SMs), phosphatidylcholines (PCs) and lysophosphatidylcholines (lysoPCs) species. A significant genotype effect was detected in response to challenge tests in 6 SMs (C16:0, C16:1, C18:0, C18:1, C24:0, C24:1), 5 hydroxy-SMs (C14:1, C16:1, C22:1, C22:2, C24:1), 4 lysoPCs (C14:0, C16:0, C16:1, C17:0), 3 diacyl-PCs (C28:1, C36:6, C40:4) and 4 long-chain acyl-alkyl-PCs (C40:2, C40:5, C44:5, C44:6). Plasma metabolomic profiling identified alterations of phospholipid metabolism in response to challenge tests in subjects with TCF7L2 rs7903146 genotype. This may reflect a genotype-mediated link to early metabolic abnormalities prior to the development of disturbed glucose tolerance.

KCNJ11 Lys23Glu and TCF7L2 rs290487(C/T) polymorphisms affect therapeutic efficacy of repaglinide in Chinese patients with type 2 diabetes.

PubMed

Yu, M; Xu, X-J; Yin, J-Y; Wu, J; Chen, X; Gong, Z-C; Ren, H-Y; Huang, Q; Sheng, F-F; Zhou, H-H; Liu, Z-Q

2010-03-01

This study showed that the polymorphisms KCNJ11 Lys23Glu and TCF7L2 rs290487(C/T) are associated with a heightened risk of developing type 2 diabetes mellitus (T2DM). We also explored the effects of these polymorphisms on the efficacy of repaglinide therapy in Chinese patients with T2DM. A total of 259 patients with T2DM and 188 healthy controls were genotyped. Forty patients with various genotypes were randomly selected to undergo an 8-week repaglinide treatment regimen. Patients with the G allele of the KCNJ11 Lys23Glu polymorphism showed higher levels of fasting plasma glucose (FPG) and postprandial plasma glucose (PPG) (P < 0.05). After repaglinide treatment, patients with the GA or AA genotype showed higher levels of FPG, PPG, and glycated hemoglobin (HbA(1c)) compared with patients with the GG genotype (P < 0.05). Patients with the C allele of TCF7L2 rs290487(C/T) had higher total cholesterol levels and lower body mass index (BMI) (P < 0.05). In patients with the TT genotype, the drug showed better efficacy with respect to levels of fasting insulin, triglycerides, and low-density lipoprotein cholesterol (LDL-c) than in patients with the CC or CT genotype (P < 0.05). The KCNJ11 and TCF7L2 polymorphisms were associated with repaglinide efficacy.

Extensive alternative splicing and dual promoter usage generate Tcf-1 protein isoforms with differential transcription control properties.

PubMed Central

Van de Wetering, M; Castrop, J; Korinek, V; Clevers, H

1996-01-01

Previously, we reported the isolation of cDNA clones representing four alternative splice forms of TCF-1, a T-cell-specific transcription factor. In the present study, Western blotting (immunoblotting) yielded a multitude of TCF-1 proteins ranging from 25-55 kDa, a pattern not simply explained from the known splice alternatives. Subsequent cDNA cloning, PCR amplification, and analysis by rapid amplification of 5' cDNA ends revealed (i) the presence of an alternative upstream promoter, which extended the known N terminus by 116 amino acids, (ii) the presence of four alternative exons, and (iii) the existence of a second reading frame in the last exon encoding an extended C terminus. Inclusion of the extended N terminus into the originally reported protein resulted in a striking similarity to the lymphoid factor Lef-1. Several of the TCF-1 isoforms, although less potent, mimicked Lef-1 in transactivating transcription through the T-cell receptor alpha-chain (TCR-alpha) enhancer. These data provide a molecular basis for the complexity of the expressed TCF-1 proteins and establish the existence of functional differences between these isoforms. Furthermore, the functional redundancy between Tcf-1 and Lef-1 explains the apparently normal TCR-alpha expression in single Tcf-1 or Lef-1 knockout mice despite the firm in vitro evidence for the importance of the Tcf/Lef site in the TCR-alpha enhancer. PMID:8622675

Plasma Metabolomics Reveal Alterations of Sphingo- and Glycerophospholipid Levels in Non-Diabetic Carriers of the Transcription Factor 7-Like 2 Polymorphism rs7903146

PubMed Central

Kirchhofer, Anna; Grallert, Harald; Krug, Susanne; Kastenmüller, Gabi; Römisch-Margl, Werner; Claussnitzer, Melina; Illig, Thomas; Heier, Margit; Meisinger, Christa; Adamski, Jerzy; Thorand, Barbara; Huth, Cornelia; Peters, Annette; Prehn, Cornelia; Heukamp, Ina; Laumen, Helmut; Lechner, Andreas; Hauner, Hans; Seissler, Jochen

2013-01-01

Aims/Hypothesis Polymorphisms in the transcription factor 7-like 2 (TCF7L2) gene have been shown to display a powerful association with type 2 diabetes. The aim of the present study was to evaluate metabolic alterations in carriers of a common TCF7L2 risk variant. Methods Seventeen non-diabetic subjects carrying the T risk allele at the rs7903146 TCF7L2 locus and 24 subjects carrying no risk allele were submitted to intravenous glucose tolerance test and euglycemic-hyperinsulinemic clamp. Plasma samples were analysed for concentrations of 163 metabolites through targeted mass spectrometry. Results TCF7L2 risk allele carriers had a reduced first-phase insulin response and normal insulin sensitivity. Under fasting conditions, carriers of TCF7L2 rs7903146 exhibited a non-significant increase of plasma sphingomyelins (SMs), phosphatidylcholines (PCs) and lysophosphatidylcholines (lysoPCs) species. A significant genotype effect was detected in response to challenge tests in 6 SMs (C16:0, C16:1, C18:0, C18:1, C24:0, C24:1), 5 hydroxy-SMs (C14:1, C16:1, C22:1, C22:2, C24:1), 4 lysoPCs (C14:0, C16:0, C16:1, C17:0), 3 diacyl-PCs (C28:1, C36:6, C40:4) and 4 long-chain acyl-alkyl-PCs (C40:2, C40:5, C44:5, C44:6). Discussion Plasma metabolomic profiling identified alterations of phospholipid metabolism in response to challenge tests in subjects with TCF7L2 rs7903146 genotype. This may reflect a genotype-mediated link to early metabolic abnormalities prior to the development of disturbed glucose tolerance. PMID:24205231

Association of type 2 diabetes susceptibility genes (TCF7L2, SLC30A8, PCSK1 and PCSK2) and proinsulin conversion in a Chinese population.

PubMed

Zheng, Xiaoya; Ren, Wei; Zhang, Suhua; Liu, Jingjing; Li, Sufang; Li, Jinchao; Yang, Ping; He, Jun; Su, Shaochu; Li, Ping

2012-01-01

TCF7L2 and SLC30A8 have been found to be associated with type 2 diabetes mellitus (T2DM) as well as with impaired proinsulin processing recently, enzymes encoded by PCSK1 and PCSK2 are reported to play an important role in the process of proinsulin conversion. To investigate whether the single nucleotide polymorphisms (SNPs) of TCF7L2, SLC30A8, PCSK1 and PCSK2 were associated with T2DM as well as with proinsulin conversion in a Han Chinese population from Chongqing. A case-control study was performed in Han Chinese subjects with normal control (n=152) and T2DM (n=227), we genotyped rs7903146 and rs11196218 at TCF7L2, rs13266634 at SLC30A8, rs3811951 at PCSK1 and rs2021785 at PCSK2. Plasma levels of proinsulin were measured with an Enzyme Linked Immunosorbent Assay (ELISA). Genotype distribution and associations with T2DM and fasting levels of proinsulin and proinsulin/insulin ratios were analyzed. We confirmed the association of risk allele of rs2021785 at PCSK2 with type 2 diabetes also existed in Han Chinese population [OR=1.4489 with 95% CI (1.0285, 2.0412), P=0.0335]. Rs13266634 at SLC30A8 had a tendency to be associated with fasting plasma levels of proinsulin (P=0.0639 in additive model). We did not find the significant association between other SNPs and T2DM or fasting levels of proinsulin or proinsulin/insulin ratios. Our results provide evidence that the association of PCSK2 and T2DM was also existed in Han Chinese population in Chongqing. We were underpowered to detect the association between other SNPs and T2DM or proinsulin conversion.

Connective tissue fibroblasts and Tcf4 regulate myogenesis

PubMed Central

Mathew, Sam J.; Hansen, Jody M.; Merrell, Allyson J.; Murphy, Malea M.; Lawson, Jennifer A.; Hutcheson, David A.; Hansen, Mark S.; Angus-Hill, Melinda; Kardon, Gabrielle

2011-01-01

Muscle and its connective tissue are intimately linked in the embryo and in the adult, suggesting that interactions between these tissues are crucial for their development. However, the study of muscle connective tissue has been hindered by the lack of molecular markers and genetic reagents to label connective tissue fibroblasts. Here, we show that the transcription factor Tcf4 (transcription factor 7-like 2; Tcf7l2) is strongly expressed in connective tissue fibroblasts and that Tcf4GFPCre mice allow genetic manipulation of these fibroblasts. Using this new reagent, we find that connective tissue fibroblasts critically regulate two aspects of myogenesis: muscle fiber type development and maturation. Fibroblasts promote (via Tcf4-dependent signals) slow myogenesis by stimulating the expression of slow myosin heavy chain. Also, fibroblasts promote the switch from fetal to adult muscle by repressing (via Tcf4-dependent signals) the expression of developmental embryonic myosin and promoting (via a Tcf4-independent mechanism) the formation of large multinucleate myofibers. In addition, our analysis of Tcf4 function unexpectedly reveals a novel mechanism of intrinsic regulation of muscle fiber type development. Unlike other intrinsic regulators of fiber type, low levels of Tcf4 in myogenic cells promote both slow and fast myogenesis, thereby promoting overall maturation of muscle fiber type. Thus, we have identified novel extrinsic and intrinsic mechanisms regulating myogenesis. Most significantly, our data demonstrate for the first time that connective tissue is important not only for adult muscle structure and function, but is a vital component of the niche within which muscle progenitors reside and is a critical regulator of myogenesis. PMID:21177349

Transient Tcf3 Gene Repression by TALE-Transcription Factor Targeting.

PubMed

Masuda, Junko; Kawamoto, Hiroshi; Strober, Warren; Takayama, Eiji; Mizutani, Akifumi; Murakami, Hiroshi; Ikawa, Tomokatsu; Kitani, Atsushi; Maeno, Narumi; Shigehiro, Tsukasa; Satoh, Ayano; Seno, Akimasa; Arun, Vaidyanath; Kasai, Tomonari; Fuss, Ivan J; Katsura, Yoshimoto; Seno, Masaharu

2016-12-01

Transplantation of hematopoietic stem and progenitor cells (HSCs) i.e., self-renewing cells that retain multipotentiality, is now a widely performed therapy for many hematopoietic diseases. However, these cells are present in low number and are subject to replicative senescence after extraction; thus, the acquisition of sufficient numbers of cells for transplantation requires donors able to provide repetitive blood samples and/or methods of expanding cell numbers without disturbing cell multipotentiality. Previous studies have shown that HSCs maintain their multipotentiality and self-renewal activity if TCF3 transcription function is blocked under B cell differentiating conditions. Taking advantage of this finding to devise a new approach to HSC expansion in vitro, we constructed an episomal expression vector that specifically targets and transiently represses the TCF3 gene. This consisted of a vector encoding a transcription activator-like effector (TALE) fused to a Krüppel-associated box (KRAB) repressor. We showed that this TALE-KRAB vector repressed expression of an exogenous reporter gene in HEK293 and COS-7 cell lines and, more importantly, efficiently repressed endogenous TCF3 in a human B lymphoma cell line. These findings suggest that this vector can be used to maintain multipotentiality in HSC being subjected to a long-term expansion regimen prior to transplantation.

Epigenetic inactivation of TCF2 in ovarian cancer and various cancer cell lines

PubMed Central

Terasawa, K; Toyota, M; Sagae, S; Ogi, K; Suzuki, H; Sonoda, T; Akino, K; Maruyama, R; Nishikawa, N; Imai, K; Shinomura, Y; Saito, T; Tokino, T

2006-01-01

Transcription factor 2 gene (TCF2) encodes hepatocyte nuclear factor 1β (HNF1β), a transcription factor associated with development and metabolism. Mutation of TCF2 has been observed in renal cell cancer, and by screening aberrantly methylated genes, we have now identified TCF2 as a target for epigenetic inactivation in ovarian cancer. TCF2 was methylated in 53% of ovarian cancer cell lines and 26% of primary ovarian cancers, resulting in loss of the gene's expression. TCF2 expression was restored by treating cells with a methyltransferase inhibitor, 5-aza-2′deoxycitidine (5-aza-dC). In addition, chromatin immunoprecipitation showed deacetylation of histone H3 in methylated cells and, when combined with 5-aza-dC, the histone deacetylase inhibitor trichostatin A synergistically induced TCF2 expression. Epigenetic inactivation of TCF2 was also seen in colorectal, gastric and pancreatic cell lines, suggesting general involvement of epigenetic inactivation of TCF2 in tumorigenesis. Restoration of TCF2 expression induced expression of HNF4α, a transcriptional target of HNF1β, indicating that epigenetic silencing of TCF2 leads to alteration of the hepatocyte nuclear factor network in tumours. These results suggest that TCF2 is involved in the development of ovarian cancers and may represent a useful target for their detection and treatment. PMID:16479257

Tcf7 Is an Important Regulator of the Switch of Self-Renewal and Differentiation in a Multipotential Hematopoietic Cell Line

PubMed Central

Schulz, Vincent P.; Hariharan, Manoj; Tuck, David; Lian, Jin; Du, Jiang; Shi, Minyi; Ye, Zhijia; Gerstein, Mark; Snyder, Michael P.; Weissman, Sherman

2012-01-01

A critical problem in biology is understanding how cells choose between self-renewal and differentiation. To generate a comprehensive view of the mechanisms controlling early hematopoietic precursor self-renewal and differentiation, we used systems-based approaches and murine EML multipotential hematopoietic precursor cells as a primary model. EML cells give rise to a mixture of self-renewing Lin-SCA+CD34+ cells and partially differentiated non-renewing Lin-SCA-CD34− cells in a cell autonomous fashion. We identified and validated the HMG box protein TCF7 as a regulator in this self-renewal/differentiation switch that operates in the absence of autocrine Wnt signaling. We found that Tcf7 is the most down-regulated transcription factor when CD34+ cells switch into CD34− cells, using RNA–Seq. We subsequently identified the target genes bound by TCF7, using ChIP–Seq. We show that TCF7 and RUNX1 (AML1) bind to each other's promoter regions and that TCF7 is necessary for the production of the short isoforms, but not the long isoforms of RUNX1, suggesting that TCF7 and the short isoforms of RUNX1 function coordinately in regulation. Tcf7 knock-down experiments and Gene Set Enrichment Analyses suggest that TCF7 plays a dual role in promoting the expression of genes characteristic of self-renewing CD34+ cells while repressing genes activated in partially differentiated CD34− state. Finally a network of up-regulated transcription factors of CD34+ cells was constructed. Factors that control hematopoietic stem cell (HSC) establishment and development, cell growth, and multipotency were identified. These studies in EML cells demonstrate fundamental cell-intrinsic properties of the switch between self-renewal and differentiation, and yield valuable insights for manipulating HSCs and other differentiating systems. PMID:22412390

TCF7L2 genetic variants modulate the effect of dietary fat intake on changes in body composition during a weight-loss intervention.

PubMed

Mattei, Josiemer; Qi, Qibin; Hu, Frank B; Sacks, Frank M; Qi, Lu

2012-11-01

TCF7L2 gene variants have been associated with increased risk of type 2 diabetes and higher adiposity. Observational studies and short-term trials have suggested that macronutrients may modify these effects. However, to our knowledge, this has yet to be verified in long-term interventions. In a long-term intervention setting, we investigated the effects of TCF7L2 polymorphisms rs7903146 and rs12255372 and dietary total fat on changes in body composition and subsequent glycemic control. Data were analyzed for 591 participants in the Preventing Overweight Using Novel Dietary Strategies (Pounds Lost) trial, which is a 2-y weight-loss randomized clinical trial of diets that differed in macronutrient proportions. Adjusted means for changes in body composition at 6 and 24 mo were obtained for gene main effects and interactions with a low-fat diet (20% from energy) compared with a high-fat diet (40% from energy). Interactions with protein and carbohydrate intakes were also tested. Predicted changes in glycemic control from changes in adiposity were determined by genotype and diet type. Significant interactions were observed for rs12255372 TT (risk genotype) and fat intake for changes in BMI, total fat mass, and trunk fat mass (all P/q < 0.05) at 6 mo, with nonsignificant larger decreases for TT carriers on a low-fat diet. No significant associations were observed at 24 mo or for other macronutrients. Changes in body composition for TT carriers predicted reductions in plasma glucose and insulin only on the low-fat diet. Individuals with the TCF7L2 rs12255372 risk genotype may reduce body adiposity by consuming a diet lower in total fat. These reductions may induce better glycemic control for such individuals predisposed to type 2 diabetes. The Pounds Lost trial was registered at clinicaltrials.gov as NCT00072995.

Regulation of TCF ETS-domain transcription factors by helix-loop-helix motifs.

PubMed

Stinson, Julie; Inoue, Toshiaki; Yates, Paula; Clancy, Anne; Norton, John D; Sharrocks, Andrew D

2003-08-15

DNA binding by the ternary complex factor (TCF) subfamily of ETS-domain transcription factors is tightly regulated by intramolecular and intermolecular interactions. The helix-loop-helix (HLH)-containing Id proteins are trans-acting negative regulators of DNA binding by the TCFs. In the TCF, SAP-2/Net/ERP, intramolecular inhibition of DNA binding is promoted by the cis-acting NID region that also contains an HLH-like motif. The NID also acts as a transcriptional repression domain. Here, we have studied the role of HLH motifs in regulating DNA binding and transcription by the TCF protein SAP-1 and how Cdk-mediated phosphorylation affects the inhibitory activity of the Id proteins towards the TCFs. We demonstrate that the NID region of SAP-1 is an autoinhibitory motif that acts to inhibit DNA binding and also functions as a transcription repression domain. This region can be functionally replaced by fusion of Id proteins to SAP-1, whereby the Id moiety then acts to repress DNA binding in cis. Phosphorylation of the Ids by cyclin-Cdk complexes results in reduction in protein-protein interactions between the Ids and TCFs and relief of their DNA-binding inhibitory activity. In revealing distinct mechanisms through which HLH motifs modulate the activity of TCFs, our results therefore provide further insight into the role of HLH motifs in regulating TCF function and how the inhibitory properties of the trans-acting Id HLH proteins are themselves regulated by phosphorylation.

Resequencing and Analysis of Variation in the TCF7L2 Gene in African Americans Suggests That SNP rs7903146 Is the Causal Diabetes Susceptibility Variant

PubMed Central

Palmer, Nicholette D.; Hester, Jessica M.; An, S. Sandy; Adeyemo, Adebowale; Rotimi, Charles; Langefeld, Carl D.; Freedman, Barry I.; Ng, Maggie C.Y.; Bowden, Donald W.

2011-01-01

OBJECTIVE Variation in the transcription factor 7-like 2 (TCF7L2) locus is associated with type 2 diabetes across multiple ethnicities. The aim of this study was to elucidate which variant in TCF7L2 confers diabetes susceptibility in African Americans. RESEARCH DESIGN AND METHODS Through the evaluation of tagging single nucleotide polymorphisms (SNPs), type 2 diabetes susceptibility was limited to a 4.3-kb interval, which contains the YRI (African) linkage disequilibrium (LD) block containing rs7903146. To better define the relationship between type 2 diabetes risk and genetic variation we resequenced this 4.3-kb region in 96 African American DNAs. Thirty-three novel and 13 known SNPs were identified: 20 with minor allele frequencies (MAF) >0.05 and 12 with MAF >0.10. These polymorphisms and the previously identified DG10S478 microsatellite were evaluated in African American type 2 diabetic cases (n = 1,033) and controls (n = 1,106). RESULTS Variants identified from direct sequencing and databases were genotyped or imputed. Fifteen SNPs showed association with type 2 diabetes (P < 0.05) with rs7903146 being the most significant (P = 6.32 × 10−6). Results of imputation, haplotype, and conditional analysis of SNPs were consistent with rs7903146 being the trait-defining SNP. Analysis of the DG10S478 microsatellite, which is outside the 4.3-kb LD block, revealed consistent association of risk allele 8 with type 2 diabetes (odds ratio [OR] = 1.33; P = 0.022) as reported in European populations; however, allele 16 (MAF = 0.016 cases and 0.032 controls) was strongly associated with reduced risk (OR = 0.39; P = 5.02 × 10−5) in contrast with previous studies. CONCLUSIONS In African Americans, these observations suggest that rs7903146 is the trait-defining polymorphism associated with type 2 diabetes risk. Collectively, these results support ethnic differences in type 2 diabetes associations. PMID:20980453

TCF and Groucho-related genes influence pituitary growth and development.

PubMed

Brinkmeier, Michelle L; Potok, Mary Anne; Cha, Kelly B; Gridley, Thomas; Stifani, Stefano; Meeldijk, Jan; Clevers, Hans; Camper, Sally A

2003-11-01

Mutations in the prophet of PIT1 gene (PROP1) are the most common cause of multiple pituitary hormone deficiency in humans; however, the mechanism of PROP1 action is not well understood. We report that Prop1 is essential for dorsally restricted expression of a Groucho-related gene, transducin-like enhancer of split 3 (Tle3), which encodes a transcriptional corepressor. Deficiency of a related gene, amino terminal enhancer of split (Aes), causes pituitary anomalies and growth insufficiency. TLE3 and AES have been shown to interact with TCF/LEF (transcripiton factors of the T cell-specific and lymphoid enhancer specific group) family members in cell culture systems. In the absence of TCF4 (Tcf7L2), Prop1 levels are elevated, pituitary hyperplasia ensues and palate closure is abnormal. Thus, we demonstrate that Tcf4 and Aes influence pituitary growth and development, and place Tcf4 and Tle3 in the genetic hierarchy with Prop1.

Association of the Genetic Polymorphisms in Transcription Factor 7-Like 2 and Peroxisome Proliferator-Activated Receptors-γ2 with Type 2 Diabetes Mellitus and Its Interaction with Obesity Status in Emirati Population

PubMed Central

Al-Safar, Habiba; Hassoun, Ahmed; Almazrouei, Shaikha; Kamal, Wala; Afandi, Bachar; Rais, Naushad

2015-01-01

Background. Transcription factor 7-like 2 gene (TCF7L2) and peroxisome proliferator-activated receptors-γ2 (PPAR-γ2) have a profound effect on the incidence of type 2 diabetes mellitus (T2DM) and had previously been found to be associated with T2DM risk in various ppopulations. However, studies in the Arab population are inconsistent. We conducted a case control study to confirm the association of variants rs10885409 of TCF7L2 and Pro12Ala (rs1801282) of PPAR-γ2 with risk of T2DM and related complications in Emirati population of Arab origin. We also investigated the interaction of these associations with obesity status. Methods. DNA was extracted from the saliva samples of 272 T2DM patients and 216 nondiabetic Emiratis. Genotyping for rs10885409 (TCF7L2) and rs1801282 (PPAR-γ2 P12A) variants was accomplished with a TaqMan assay. The subgroups were constituted according to obesity status. Results. In the nonobese group, the rs10885409 C allele in the recessive model was significantly associated with the incidence of T2DM (OR 1.975 [95% CI 1.127–3.461], P = 0.017), but this association was not observed in the obese group or when BMI was not considered. PPAR-γ2 risk allele Pro12 frequency (0.96) was similar in the groups tested and more than 90% population was homozygous for this allele. Conclusions. Our case-control study is the first of its kind in Emiratis which establishes TCF7L2 rs10885409 C allele as a T2DM risk factor in Emiratis and this association is modulated by obesity status. We also confirmed that Pro12Ala mutation in PPAR-γ2 is not associated with T2DM risk in this population. PMID:26273662

Association of the Genetic Polymorphisms in Transcription Factor 7-Like 2 and Peroxisome Proliferator-Activated Receptors- γ 2 with Type 2 Diabetes Mellitus and is Interaction with Obesity Status in Emirati Population.

PubMed

Al-Safar, Habiba; Hassoun, Ahmed; Almazrouei, Shaikha; Kamal, Wala; Afandi, Bachar; Rais, Naushad

2015-01-01

Transcription factor 7-like 2 gene (TCF7L2) and peroxisome proliferator-activated receptors-γ2 (PPAR-γ2) have a profound effect on the incidence of type 2 diabetes mellitus (T2DM) and had previously been found to be associated with T2DM risk in various ppopulations. However, studies in the Arab population are inconsistent. We conducted a case control study to confirm the association of variants rs10885409 of TCF7L2 and Pro12Ala (rs1801282) of PPAR-γ2 with risk of T2DM and related complications in Emirati population of Arab origin. We also investigated the interaction of these associations with obesity status. DNA was extracted from the saliva samples of 272 T2DM patients and 216 nondiabetic Emiratis. Genotyping for rs10885409 (TCF7L2) and rs1801282 (PPAR-γ2 P12A) variants was accomplished with a TaqMan assay. The subgroups were constituted according to obesity status. In the nonobese group, the rs10885409 C allele in the recessive model was significantly associated with the incidence of T2DM (OR 1.975 [95% CI 1.127-3.461], P = 0.017), but this association was not observed in the obese group or when BMI was not considered. PPAR-γ2 risk allele Pro12 frequency (0.96) was similar in the groups tested and more than 90% population was homozygous for this allele. Our case-control study is the first of its kind in Emiratis which establishes TCF7L2 rs10885409 C allele as a T2DM risk factor in Emiratis and this association is modulated by obesity status. We also confirmed that Pro12Ala mutation in PPAR-γ2 is not associated with T2DM risk in this population.

Caveolin-1–mediated Suppression of Cyclooxygenase-2 via a β-catenin-Tcf/Lef–dependent Transcriptional Mechanism Reduced Prostaglandin E2 Production and Survivin Expression

PubMed Central

Rodriguez, Diego A.; Tapia, Julio C.; Fernandez, Jaime G.; Torres, Vicente A.; Muñoz, Nicolas; Galleguillos, Daniela; Leyton, Lisette

2009-01-01

Augmented expression of cyclooxygenase-2 (COX-2) and enhanced production of prostaglandin E2 (PGE2) are associated with increased tumor cell survival and malignancy. Caveolin-1 is a scaffold protein that has been proposed to function as a tumor suppressor in human cancer cells, although mechanisms underlying this ability remain controversial. Intriguingly, the possibility that caveolin-1 regulates the expression of COX-2 has not been explored. Here we show that augmented caveolin-1 expression in cells with low basal levels of this protein, such as human colon cancer (HT29, DLD-1), breast cancer (ZR75), and embryonic kidney (HEK293T) cells reduced COX-2 mRNA and protein levels and β-catenin-Tcf/Lef and COX-2 gene reporter activity, as well as the production of PGE2 and cell proliferation. Moreover, COX-2 overexpression or PGE2 supplementation increased levels of the inhibitor of apoptosis protein survivin by a transcriptional mechanism, as determined by PCR analysis, survivin gene reporter assays and Western blotting. Furthermore, addition of PGE2 to the medium prevented effects attributed to caveolin-1–mediated inhibition of β-catenin-Tcf/Lef–dependent transcription. Finally, PGE2 reduced the coimmunoprecipitation of caveolin-1 with β-catenin and their colocalization at the plasma membrane. Thus, by reducing COX-2 expression, caveolin-1 interrupts a feedback amplification loop involving PGE2-induced signaling events linked to β-catenin/Tcf/Lef–dependent transcription of tumor survival genes including cox-2 itself and survivin. PMID:19244345

Metabolic, hormonal characteristics and genetic variants of TCF7L2 associated with development of gestational diabetes mellitus in Mexican women.

PubMed

Reyes-López, Ruth; Pérez-Luque, Elva; Malacara, Juan Manuel

2014-11-01

Variation in TCF7L2 gene is associated with type 2 diabetes and with gestational diabetes mellitus in several populations, but there are no data in Mexican women with gestational diabetes mellitus. In this study, we examined metabolic and hormonal measurements as well as TCF7L2 genetic variants. We selected 108 pregnant women with normal glucose tolerance and 90 with gestational diabetes mellitus according to 2010 American Diabetes Association criteria matched for gestational week. We collected data on blood pressure, body mass index (BMI) and concentrations of blood glucose, HbA1c , lipids profile, insulin and glucagon-like peptide-1 (GLP-1). The genotyping of rs7903146 and rs12255372 polymorphisms were made with polymerase chain reaction-restriction fragment length polymorphism. Actual and pre-gestational BMI, fasting glucose and HbA1c were higher (p < 0.001), and high-density lipoprotein cholesterol was lower (p < 0.02) in gestational diabetes mellitus women than euglycemic women. No significant differences were found for lipids, insulin and homeostasis model assessment-insulin resistance. Gestational diabetes mellitus women had high GLP-1 levels (32 vs 24, p < 0.004) and decreased β-cell function (266 vs 438, p < 0.001). The frequency of rs12255372 risk allele in gestational diabetes women was significantly higher than that in euglycemic women (χ²  = 8.96; p < 0.003) and confers a risk for gestational diabetes mellitus (OR = 9.1, 95% CI 2.8-29, p < 0.0002; and OR = 4.3, 95% CI 1.6-11.4, p < 0.003 based on dominant and co-dominant model, respectively). The generalized linear model showed that low beta function, high pre-gestational BMI and rs12255372 risk allele are independently associated with gestational diabetes. The elevated GLP-1 levels in gestational diabetes women suggested some abnormality in insulin secretion. The low β-cell function, high pre-gestational BMI and rs12255372 risk allele are risk factors

A Druggable TCF4 and BRD4 dependent Transcriptional Network Sustains Malignancy in Blastic Plasmacytoid Dendritic Cell Neoplasm

PubMed Central

Ceribelli, Michele; Hou, Zhiying Esther; Kelly, Priscilla N.; Huang, Da Wei; Wright, George; Ganapathi, Karthik; Evbuomwan, Moses O.; Pittaluga, Stefania; Shaffer, Arthur L.; Marcucci, Guido; Forman, Stephen J.; Xiao, Wenming; Guha, Rajarshi; Zhang, Xiaohu; Ferrer, Marc; Chaperot, Laurence; Plumas, Joel; Jaffe, Elaine S.; Thomas, Craig J.; Reizis, Boris; Staudt, Louis M.

2016-01-01

SUMMARY Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is an aggressive and largely incurable hematologic malignancy originating from plasmacytoid dendritic cells (pDCs). Using RNA interference screening, we identified the E-box transcription factor TCF4 as a master regulator of the BPDCN oncogenic program. TCF4 served as a faithful diagnostic marker of BPDCN, and its downregulation caused the loss of the BPDCN-specific gene expression program and apoptosis. High-throughput drug screening revealed that bromodomain and extra-terminal domain inhibitors (BETi’s) induced BPDCN apoptosis, which was attributable to disruption of a BPDCN-specific transcriptional network controlled by TCF4-dependent super-enhancers. BETi’s retarded the growth of BPDCN xenografts, supporting their clinical evaluation in this recalcitrant malignancy. PMID:27846392

Telomeric noncoding RNA promotes mouse embryonic stem cell self-renewal through inhibition of TCF3 activity.

PubMed

Xu, Xiaojuan; Guo, Mengmeng; Zhang, Na; Ye, Shoudong

2018-06-01

Although long noncoding RNAs (lncRNAs) are emerging as new modulators in the fate decision of pluripotent stem cells, the functions of specific lncRNAs remain unclear. Here, we found that telomeric RNA (TERRA or TelRNA), one type of lncRNAs, is highly expressed in mouse embryonic stem cells (mESCs) but declines significantly upon differentiation. TERRA is induced by the Wnt/β-catenin signaling pathway and can reproduce its self-renewal-promoting effect when overexpressed. Further studies revealed that T cell factor 3 ( TCF3) is a potential downstream target of TERRA and mediates the effect of TERRA in mESC maintenance. TERRA inhibits TCF3 transcription, while enforced TCF3 expression abrogates the undifferentiated state of mESCs supported by TERRA. Accordingly, the transcripts of the pluripotency genes Esrrb, Tfcp2l1, and Klf2, repressed by TCF3 in mESCs, are increased in TERRA-overexpressing cells. Our study therefore highlights the important role of TERRA in mESC maintenance and also uncovers a mechanism by which TERRA promotes self-renewal. These data will expand our understanding of the pluripotent regulatory network of ESCs.

Survivin expression promotes VEGF-induced tumor angiogenesis via PI3K/Akt enhanced β-catenin/Tcf-Lef dependent transcription.

PubMed

Fernández, Jaime G; Rodríguez, Diego A; Valenzuela, Manuel; Calderon, Claudia; Urzúa, Ulises; Munroe, David; Rosas, Carlos; Lemus, David; Díaz, Natalia; Wright, Mathew C; Leyton, Lisette; Tapia, Julio C; Quest, Andrew Fg

2014-09-09

Early in cancer development, tumour cells express vascular endothelial growth factor (VEGF), a secreted molecule that is important in all stages of angiogenesis, an essential process that provides nutrients and oxygen to the nascent tumor and thereby enhances tumor-cell survival and facilitates growth. Survivin, another protein involved in angiogenesis, is strongly expressed in most human cancers, where it promotes tumor survival by reducing apoptosis as well as favoring endothelial cell proliferation and migration. The mechanisms by which cancer cells induce VEGF expression and angiogenesis upon survivin up-regulation remain to be fully established. Since the PI3K/Akt signalling and β-catenin-Tcf/Lef dependent transcription have been implicated in the expression of many cancer-related genes, including survivin and VEGF, we evaluated whether survivin may favor VEGF expression, release from tumor cells and induction of angiogenesis in a PI3K/Akt-β-catenin-Tcf/Lef-dependent manner. Here, we provide evidence linking survivin expression in tumor cells to increased β-catenin protein levels, β-catenin-Tcf/Lef transcriptional activity and expression of several target genes of this pathway, including survivin and VEGF, which accumulates in the culture medium. Alternatively, survivin downregulation reduced β-catenin protein levels and β-catenin-Tcf/Lef transcriptional activity. Also, using inhibitors of PI3K and the expression of dominant negative Akt, we show that survivin acts upstream in an amplification loop to promote VEGF expression. Moreover, survivin knock-down in B16F10 murine melanoma cells diminished the number of blood vessels and reduced VEGF expression in tumors formed in C57BL/6 mice. Finally, in the chick chorioallantoid membrane assay, survivin expression in tumor cells enhanced VEGF liberation and blood vessel formation. Importantly, the presence of neutralizing anti-VEGF antibodies precluded survivin-enhanced angiogenesis in this assay. These

Androgen Receptor (AR) Suppresses Normal Human Prostate Epithelial Cell Proliferation via AR/β-catenin/TCF-4 Complex Inhibition of c-MYC Transcription

PubMed Central

Antony, Lizamma; van der Schoor, Freek; Dalrymple, Susan L.; Isaacs, John T.

2016-01-01

INTRODUCTION Physiologic testosterone continuously stimulates prostate stromal cell secretion of paracrine growth factors (PGFs), which if unopposed would induce hyperplastic overgrowth of normal prostate epithelial cells (PrECs). METHODS Lentiviral shRNA stable knock down of c-MYC, β-catenin, or TCF-4 completely inhibits normal (i.e., non-transformed) human PrECs growth. c-MYC enhancer driven reporter expression and growth is inhibited by two chemically distinct molecules, which prevent β-catenin signaling either by blocking TCF-4 binding (i.e., toxoflavin) or by stimulating degradation (i.e., AVX939). Recombinant DKK1 protein at a dose, which inhibits activation of canonical Wnt signaling does not inhibit PrEC growth. Nuclear β-catenin translocation and PrEC growth is prevented by both lack of PGFs or Akt inhibitor-I. Growth inhibition induced by lack of PGFs, toxoflavin, or Akt inhibitor-I is overcome by constitutive c-MYC transcription. RESULTS In the presence of continuous PGF signaling, PrEC hyperplasia is prevented by androgen binding to AR suppressing c-MYC transcription, resulting in G0 arrest/terminal differentiation independent of Rb, p21, p27, FoxP3, or down regulation of growth factors receptors and instead involves androgen-induced formation of AR/β-catenin/TCF-4 complexes, which suppress c-MYC transcription. Such suppression does not occur when AR is mutated in its zinc-finger binding domain. DISCUSSION Proliferation of non-transformed human PrECs is dependent upon c-MYC transcription via formation/binding of β-catenin/TCF-4 complexes at both 5′ and 3′ c-MYC enhancers stimulated by Wnt-independent, PGF induced Akt signaling. In the presence of continuous PGF signaling, PrEC hyperplasia is prevented by androgen-induced formation of AR/β-catenin/TCF-4 complexes, which retains binding to 3′ c-MYC enhancer, but now suppresses c-MYC transcription. PMID:24913829

Contribution of common variants of ENPP1, IGF2BP2, KCNJ11, MLXIPL, PPARγ, SLC30A8 and TCF7L2 to the risk of type 2 diabetes in Lebanese and Tunisian Arabs.

PubMed

Mtiraoui, N; Turki, A; Nemr, R; Echtay, A; Izzidi, I; Al-Zaben, G S; Irani-Hakime, N; Keleshian, S H; Mahjoub, T; Almawi, W Y

2012-11-01

While several type 2 diabetes mellitus (T2DM) susceptibility loci identified through genome-wide association studies (GWAS) have been replicated in many populations, their association in Arabs has not been reported. For this reason, the present study looked at the contribution of ENNP1 (rs1044498), IGF2BP2 (rs1470579), KCNJ11 (rs5219), MLXIPL (rs7800944), PPARγ (rs1801282), SLC30A8 (rs13266634) and TCF7L2 (rs7903146) SNPs to the risk of T2DM in Lebanese and Tunisian Arabs. Study subjects (case/controls) were Lebanese (751/918) and Tunisians (1470/838). Genotyping was carried out by the allelic discrimination method. In Lebanese and Tunisians, neither ENNP1 nor MLXIPL was associated with T2DM, whereas TCF7L2 was significantly associated with an increased risk of T2DM in both the Lebanese [P < 0.001; OR (95% CI): 1.38 (1.20-1.59)] and Tunisians [P < 0.001; OR (95% CI): 1.36 (1.18-1.56)]. Differential associations of IGF2BP2, KCNJ11, PPARγ and SLC30A8 with T2DM were noted in the two populations. IGF2BP2 [P = 1.3 × 10(-5); OR (95% CI): 1.66 (1.42-1.94)] and PPARγ [P = 0.005; OR (95% CI): 1.41 (1.10-1.80)] were associated with T2DM in the Lebanese, but not Tunisians, while KCNJ11 [P = 8.0 × 10(-4); OR (95% CI): 1.27 (1.09-1.47)] and SLC30A8 [P = 1.6 × 10(-5); OR (95% CI): 1.37 (1.15-1.62)] were associated with T2DM in the Tunisians, but not Lebanese, after adjusting for gender and body mass index. T2DM susceptibility loci SNPs identified through GWAS showed differential associations with T2DM in two Arab populations, thus further confirming the ethnic contributions of these variants to T2DM susceptibility. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Type 2 Diabetes Susceptibility in the Greek-Cypriot Population: Replication of Associations with TCF7L2, FTO, HHEX, SLC30A8 and IGF2BP2 Polymorphisms

PubMed Central

Votsi, Christina; Toufexis, Costas; Michailidou, Kyriaki; Antoniades, Athos; Skordis, Nicos; Karaolis, Minas; Pattichis, Constantinos S.; Christodoulou, Kyproula

2017-01-01

Type 2 diabetes (T2D) has been the subject of numerous genetic studies in recent years which revealed associations of the disease with a large number of susceptibility loci. We hereby initiate the evaluation of T2D susceptibility loci in the Greek-Cypriot population by performing a replication case-control study. One thousand and eighteen individuals (528 T2D patients, 490 controls) were genotyped at 21 T2D susceptibility loci, using the allelic discrimination method. Statistically significant associations of T2D with five of the tested single nucleotide polymorphisms (SNPs) (TCF7L2 rs7901695, FTO rs8050136, HHEX rs5015480, SLC30A8 rs13266634 and IGF2BP2 rs4402960) were observed in this study population. Furthermore, 14 of the tested SNPs had odds ratios (ORs) in the same direction as the previously published studies, suggesting that these variants can potentially be used in the Greek-Cypriot population for predictive testing of T2D. In conclusion, our findings expand the genetic assessment of T2D susceptibility loci and reconfirm five of the worldwide established loci in a distinct, relatively small, newly investigated population. PMID:28067832

Tcf21 regulates the specification and maturation of proepicardial cells

PubMed Central

Tandon, Panna; Miteva, Yana V.; Kuchenbrod, Lauren M.; Cristea, Ileana M.; Conlon, Frank L.

2013-01-01

The epicardium is a mesothelial cell layer essential for vertebrate heart development and pertinent for cardiac repair post-injury in the adult. The epicardium initially forms from a dynamic precursor structure, the proepicardial organ, from which cells migrate onto the heart surface. During the initial stage of epicardial development crucial epicardial-derived cell lineages are thought to be determined. Here, we define an essential requirement for transcription factor Tcf21 during early stages of epicardial development in Xenopus, and show that depletion of Tcf21 results in a disruption in proepicardial cell specification and failure to form a mature epithelial epicardium. Using a mass spectrometry-based approach we defined Tcf21 interactions and established its association with proteins that function as transcriptional co-repressors. Furthermore, using an in vivo systems-based approach, we identified a panel of previously unreported proepicardial precursor genes that are persistently expressed in the epicardial layer upon Tcf21 depletion, thereby confirming a primary role for Tcf21 in the correct determination of the proepicardial lineage. Collectively, these studies lead us to propose that Tcf21 functions as a transcriptional repressor to regulate proepicardial cell specification and the correct formation of a mature epithelial epicardium. PMID:23637334

Sites of instability in the human TCF3 (E2A) gene adopt G-quadruplex DNA structures in vitro

PubMed Central

Williams, Jonathan D.; Fleetwood, Sara; Berroyer, Alexandra; Kim, Nayun; Larson, Erik D.

2015-01-01

The formation of highly stable four-stranded DNA, called G-quadruplex (G4), promotes site-specific genome instability. G4 DNA structures fold from repetitive guanine sequences, and increasing experimental evidence connects G4 sequence motifs with specific gene rearrangements. The human transcription factor 3 (TCF3) gene (also termed E2A) is subject to genetic instability associated with severe disease, most notably a common translocation event t(1;19) associated with acute lymphoblastic leukemia. The sites of instability in TCF3 are not randomly distributed, but focused to certain sequences. We asked if G4 DNA formation could explain why TCF3 is prone to recombination and mutagenesis. Here we demonstrate that sequences surrounding the major t(1;19) break site and a region associated with copy number variations both contain G4 sequence motifs. The motifs identified readily adopt G4 DNA structures that are stable enough to interfere with DNA synthesis in physiological salt conditions in vitro. When introduced into the yeast genome, TCF3 G4 motifs promoted gross chromosomal rearrangements in a transcription-dependent manner. Our results provide a molecular rationale for the site-specific instability of human TCF3, suggesting that G4 DNA structures contribute to oncogenic DNA breaks and recombination. PMID:26029241

Microtubule actin crosslinking factor 1 promotes osteoblast differentiation by promoting β-catenin/TCF1/Runx2 signaling axis.

PubMed

Hu, Lifang; Su, Peihong; Yin, Chong; Zhang, Yan; Li, Runzhi; Yan, Kun; Chen, Zhihao; Li, Dijie; Zhang, Ge; Wang, Liping; Miao, Zhiping; Qian, Airong; Xian, Cory J

2018-02-01

Osteoblast differentiation is a multistep process delicately regulated by many factors, including cytoskeletal dynamics and signaling pathways. Microtubule actin crosslinking factor 1 (MACF1), a key cytoskeletal linker, has been shown to play key roles in signal transduction and in diverse cellular processes; however, its role in regulating osteoblast differentiation is still needed to be elucidated. To further uncover the functions and mechanisms of action of MACF1 in osteoblast differentiation, we examined effects of MACF1 knockdown (MACF1-KD) in MC3T3-E1 osteoblastic cells on their osteoblast differentiation and associated molecular mechanisms. The results showed that knockdown of MACF1 significantly suppressed mineralization of MC3T3-E1 cells, down-regulated the expression of key osteogenic genes alkaline phosphatase (ALP), runt-related transcription factor 2 (Runx2) and type I collagen α1 (Col Iα1). Knockdown of MACF1 dramatically reduced the nuclear translocation of β-catenin, decreased the transcriptional activation of T cell factor 1 (TCF1), and down-regulated the expression of TCF1, lymphoid enhancer-binding factor 1 (LEF1), and Runx2, a target gene of β-catenin/TCF1. In addition, MACF1-KD increased the active level of glycogen synthase kinase-3β (GSK-3β), which is a key regulator for β-catenin signal transduction. Moreover, the reduction of nuclear β-catenin amount and decreased expression of TCF1 and Runx2 were significantly reversed in MACF1-KD cells when treated with lithium chloride, an agonist for β-catenin by inhibiting GSK-3β activity. Taken together, these findings suggest that knockdown of MACF1 in osteoblastic cells inhibits osteoblast differentiation through suppressing the β-catenin/TCF1-Runx2 axis. Thus, a novel role of MACF1 in and a new mechanistic insight of osteoblast differentiation are uncovered. © 2017 Wiley Periodicals, Inc.

Decreased expression of interferon-induced protein 2 (IFIT2) by Wnt/β-catenin signaling confers anti-apoptotic properties to colorectal cancer cells

PubMed Central

Ohsugi, Tomoyuki; Yamaguchi, Kiyoshi; Zhu, Chi; Ikenoue, Tsuneo; Furukawa, Yoichi

2017-01-01

Impaired Wnt signaling pathway plays a crucial role in the development of colorectal cancer through activation of the β-catenin/TCF7L2 complex. Although genes up-regulated by Wnt/β-catenin signaling have been intensively studied, the roles of down-regulated genes are poorly understood. In this study, we explored a global gene expression of colorectal cancer cells transfected with β-catenin siRNAs or a dominant negative form of TCF7L2 (dnTCF7L2), and identified a set of genes down-regulated by Wnt/β-catenin signaling. Among the genes, we focused here on IFIT2, a gene encoding interferon-induced protein with tetratricopeptide repeats. A reporter assay using plasmids containing a 5’-flanking region of the gene showed that the reporter activity was enhanced by either transduction of β-catenin siRNA or dnTCF7L2, suggesting that the region is involved in the transcriptional regulation as a downstream of the β-catenin/TCF7L2 complex. Consistent with this result, expression of IFIT2 was significantly lower in colorectal cancer tissues than that in normal tissues. Exogenous IFIT2 expression decreased cell proliferation and increased apoptosis of colorectal cancer cells. These data suggested that the down-regulation of IFIT2 by Wnt/β-catenin signaling may play a vital role in human colorectal carcinogenesis through the suppression of apoptosis. PMID:29245969

Analysis of the interaction between transcription factor 7-like 2 genetic variants with nopal and wholegrain fibre intake: effects on anthropometric and metabolic characteristics in type 2 diabetes patients.

PubMed

López-Ortiz, M M; Garay-Sevilla, M E; Tejero, M E; Perez-Luque, E L

2016-09-01

The transcription factor 7-like 2 (TCF7L2) genetic variants have shown differential effect on low-fat and high-fat diet in obese subjects. Nopal is a Mexican variety of cactus that is a traditional food and has been used in the treatment of diabetes. Its hypoglycaemic effect may be because of its soluble fibre (mucopolysaccharide) content. This study analysed the effects of the rs7903146 and rs12255372 TCF7L2 variants on anthropometric, metabolic and hormonal parameters in type 2 diabetes mellitus patients who consumed fibre from either nopal tortilla or wholegrain bread for 8 weeks. We followed-up seventy-four patients who consumed an individualised isoenergetic diet that included nopal tortilla (Diet 1) and sixty-three patients with a diet that included wholegrain bread (Diet 2). Anthropometric, metabolic and hormonal measures were collected at baseline and final intervention. The size effect and carry-over effect were estimated. To assess the interaction of genotype and diets, we used a general linear model repeated-measures analysis. Minor allele frequency of rs7903146T was 0·27 and for rs12255372T it was 0·13. At 8 weeks after Diet 1 intake, weight, BMI, waist and hip circumference decreased (P=0·00015) in rs7903146CC and rs12255372GG genotypes. In particular, patients carrying of the rs7903146CC and consuming Diet 1 showed a reduction in waist circumference of more than 2·5 cm compared with Diet 2 (P<0·001). No significant interaction between rs7903146 or rs12255372 and diet was seen in this study. In conclusion, in the carriers of the rs7903146CC and rs12255372GG wild types, significant changes in all anthropometric measures were observed, and had better response to both diets.

AF1q is a novel TCF7 co-factor which activates CD44 and promotes breast cancer metastasis.

PubMed

Park, Jino; Schlederer, Michaela; Schreiber, Martin; Ice, Ryan; Merkel, Olaf; Bilban, Martin; Hofbauer, Sebastian; Kim, Soojin; Addison, Joseph; Zou, Jie; Ji, Chunyan; Bunting, Silvia T; Wang, Zhengqi; Shoham, Menachem; Huang, Gang; Bago-Horvath, Zsuzsanna; Gibson, Laura F; Rojanasakul, Yon; Remick, Scot; Ivanov, Alexey; Pugacheva, Elena; Bunting, Kevin D; Moriggl, Richard; Kenner, Lukas; Tse, William

2015-08-21

AF1q is an MLL fusion partner that was identified from acute myeloid leukemia (AML) patients with t (1; 11) (q21; q23) chromosomal abnormality. The function of AF1q is not yet fully known, however, elevated AF1q expression is associated with poor clinical outcomes in various malignancies. Here, we show that AF1q specifically binds to T-cell-factor-7 (TCF7) in the Wnt signaling pathway and results in transcriptional activation of CD44 as well as multiple downstream targets of the TCF7/LEF1. In addition, enhanced AF1q expression promotes breast cancer cell proliferation, migration, mammosphere formation, and chemo-resistance. In xenograft models, enforced AF1q expression in breast cancer cells also promotes liver metastasis and lung colonization. In a cohort of 63 breast cancer patients, higher percentages of AF1q-positive cancer cells in primary sites were associated with significantly poorer overall survival (OS), disease-free survival (DFS), and brain metastasis-free survival (b-MFS). Using paired primary/metastatic samples from the same patients, we demonstrate that AF1q-positive breast cancer cells become dynamically dominant in the metastatic sites compared to the primary sites. Our findings indicate that breast cancer cells with a hyperactive AF1q/TCF7/CD44 regulatory axis in the primary sites may represent "metastatic founder cells" which have invasive properties.

Casein kinase 2 (CK2) increases survivin expression via enhanced β-catenin–T cell factor/lymphoid enhancer binding factor-dependent transcription

PubMed Central

Tapia, J. C.; Torres, V. A.; Rodriguez, D. A.; Leyton, L.; Quest, A. F. G.

2006-01-01

Increased expression of casein kinase 2 (CK2) is associated with hyperproliferation and suppression of apoptosis in cancer. Mutations in the tumor suppressor APC (adenomatous polyposis coli) are frequent in colon cancer and often augment β-catenin–T cell factor (Tcf)/lymphoid enhancer binding factor (Lef)-dependent transcription of genes such as c-myc and cyclin-D1. CK2 has also been implicated recently in the regulation of β-catenin stability. To identify mechanisms by which CK2 promotes survival, effects of the specific CK2 inhibitors 4,5,6,7-tetrabromobenzotriazole (TBB) and 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole were assessed. TBB and 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole significantly decreased proliferation and increased apoptosis of HT29(US) colon cancer cells. RT-PCR and immunoblot analysis revealed that both inhibitors decreased survivin mRNA and protein levels in HT29(US) cells. Similar effects were observed with TBB in human DLD-1 and SW-480 colorectal cells as well as ZR-75 breast cancer cells and HEK-293T embryonic kidney cells. Expression of GFP–CK2α in HEK-293T cells resulted in β-catenin–Tcf/Lef-dependent up-regulation of survivin and increased resistance to anticancer drugs. Augmented β-catenin–Tcf/Lef-dependent transcription and resistance to apoptosis observed upon GFP–CK2α expression were abolished by TBB. Alternatively, HEK-293T cells expressing GFP–survivin were resistant to TBB-induced apoptosis. Finally, siRNA-mediated down-regulation of CK2α in HEK-293T cells coincided with reduced β-catenin and survivin levels. Taken together, these results suggest that CK2 kinase activity promotes survival by increasing survivin expression via β-catenin–Tcf/Lef-mediated transcription. Hence, selective CK2 inhibition or down-regulation in tumors may provide an attractive opportunity for the development of novel cancer therapies. PMID:17005722

Coronary heart disease-associated variation in TCF21 disrupts a miR-224 binding site and miRNA-mediated regulation.

PubMed

Miller, Clint L; Haas, Ulrike; Diaz, Roxanne; Leeper, Nicholas J; Kundu, Ramendra K; Patlolla, Bhagat; Assimes, Themistocles L; Kaiser, Frank J; Perisic, Ljubica; Hedin, Ulf; Maegdefessel, Lars; Schunkert, Heribert; Erdmann, Jeanette; Quertermous, Thomas; Sczakiel, Georg

2014-03-01

Genome-wide association studies (GWAS) have identified chromosomal loci that affect risk of coronary heart disease (CHD) independent of classical risk factors. One such association signal has been identified at 6q23.2 in both Caucasians and East Asians. The lead CHD-associated polymorphism in this region, rs12190287, resides in the 3' untranslated region (3'-UTR) of TCF21, a basic-helix-loop-helix transcription factor, and is predicted to alter the seed binding sequence for miR-224. Allelic imbalance studies in circulating leukocytes and human coronary artery smooth muscle cells (HCASMC) showed significant imbalance of the TCF21 transcript that correlated with genotype at rs12190287, consistent with this variant contributing to allele-specific expression differences. 3' UTR reporter gene transfection studies in HCASMC showed that the disease-associated C allele has reduced expression compared to the protective G allele. Kinetic analyses in vitro revealed faster RNA-RNA complex formation and greater binding of miR-224 with the TCF21 C allelic transcript. In addition, in vitro probing with Pb2+ and RNase T1 revealed structural differences between the TCF21 variants in proximity of the rs12190287 variant, which are predicted to provide greater access to the C allele for miR-224 binding. miR-224 and TCF21 expression levels were anti-correlated in HCASMC, and miR-224 modulates the transcriptional response of TCF21 to transforming growth factor-β (TGF-β) and platelet derived growth factor (PDGF) signaling in an allele-specific manner. Lastly, miR-224 and TCF21 were localized in human coronary artery lesions and anti-correlated during atherosclerosis. Together, these data suggest that miR-224 interaction with the TCF21 transcript contributes to allelic imbalance of this gene, thus partly explaining the genetic risk for coronary heart disease associated at 6q23.2. These studies implicating rs12190287 in the miRNA-dependent regulation of TCF21, in conjunction with

Effects of rs7903146 variation in the Tcf7l2 gene in the lipid metabolism of three different populations.

PubMed

Perez-Martinez, Pablo; Perez-Caballero, Ana I; Garcia-Rios, Antonio; Yubero-Serrano, Elena M; Camargo, Antonio; Gomez-Luna, Maria J; Marin, Carmen; Gomez-Luna, Purificacion; Dembinska-Kiec, Aldona; Rodriguez-Cantalejo, Fernando; Tinahones, Francisco J; Roche, Helen M; Perez-Jimenez, Francisco; Lopez-Miranda, Jose; Delgado-Lista, Javier

2012-01-01

TCF7L2 rs7903146 is an important genetic factor predicting type 2 diabetes (T2DM) which has also been linked to higher cardiovascular risk. To date, there is little information about the additional impact of this single nucleotide polymorphism (SNP) beyond glucose metabolism. We studied whether rs7903146 influenced postprandial lipid metabolism in three different populations (healthy young men, metabolic syndrome (MetS) patients and elderly persons). Eighty-eight healthy males were submitted to a single saturated fatty acid-rich test meal. Additionally, 110 middle-aged MetS patients and 20 healthy elderly persons (≥ 65 years) were submitted to three different dietary models followed by test meals. Minor allele homozygotes for rs7903146 showed a worse postprandial lipemia profile in young males, as seen by a lower HDL-cholesterol and Apo A1 concentration during the postprandial lipemia and a trend towards higher triglycerides (TG), than the other genotypes. In healthy elderly persons, carriers of the minor allele showed higher total cholesterol, LDL-cholesterol, Apo B and TG in the fasting state, and a higher postprandial area under the curve for total cholesterol, Apo B, small-triglyceride rich lipoprotein (TRL) cholesterol and small-(TRL) triglycerides. These results were accompanied by differential changes in adipokines. We did not observe any influence of rs7903146 on the postprandium of MetS patients. Healthy young males and elderly persons who are carriers of the mutant allele for rs7903146 have an impaired postprandial lipid metabolism that may be mediated by an alteration in adipokine regulation, and may be related to the higher cardiovascular risk observed in these persons. ClinicalTrials.gov NCT00429195.

TCF-1 participates in the occurrence of dedifferentiated chondrosarcoma.

PubMed

Xu, Xiaolong; Tang, Xiaodong; Guo, Wei; Yang, Kang; Ren, Tingting

2016-10-01

The present study demonstrated that T cell factor 1 (TCF-1) protein, a component of the canonical Wnt/β-catenin signaling pathway, can regulate the expression of runt-related transcription factor 2 (runx2) gene and Sry-related HMG box 9 (sox9) gene, which may participate in the differentiation of chondrosarcoma. Dedifferentiated chondrosarcoma (DDCS) is a special variant of conventional chondrosarcoma (CCS), associated with poor survival and high metastasis rate. However, little is known about the mechanism of its occurrence; thus, no effective treatment is available except surgery. Earlier, high expression of runx2 and low expression of sox9 were found in DDCS compared with CCS. Using Western blot to detect clinical tissue samples (including 8 CCS samples and 8 DDCS samples) and immunohistochemistry to detect 85 different-grade chondrosarcoma specimens, a high expression of TCF-1 in DDCS tissues was found compared with CCS tissues. This difference in expression was related to patients' prognosis. Results of luciferase, chromatin immunoprecipitation, and gel electrophoresis mobility shift assays demonstrated that TCF-1 protein could bind to the promoter of runx2 gene directly and sox9 gene indirectly. Hence, it could regulate expression of runx2 gene positively and sox9 gene negatively. Furthermore, in vitro and in vivo experiments showed that TCF-1 protein was closely related to the phenotype and aggressiveness of chondrosarcoma. In conclusion, this study proved that TCF-1 participates in the dedifferentiation of DDCS, which may be mediated by runx2 gene and sox9 gene. Also, TCF-1 can be of important prognostic value and a promising therapeutic target for DDCS patients.

The planarian TCF/LEF factor Smed-tcf1 is required for the regeneration of dorsal-lateral neuronal subtypes.

PubMed

Brown, David D R; Molinaro, Alyssa M; Pearson, Bret J

2018-01-15

The adult brain of the planarian Schmidtea mediterranea (a freshwater flatworm) is a dynamic structure with constant cell turnover as well as the ability to completely regenerate de novo. Despite this, function and pattern is achieved in a reproducible manner from individual to individual in terms of the correct spatial and temporal production of specific neuronal subtypes. Although several signaling molecules have been found to be key to scaling and cell turnover, the mechanisms by which specific neural subtypes are specified remain largely unknown. Here we performed a 6 day RNAseq time course on planarians that were regenerating either 0, 1, or 2 heads in order to identify novel regulators of brain regeneration. Focusing on transcription factors, we identified a TCF/LEF factor, Smed-tcf1, which was required to correctly pattern the dorsal-lateral cell types of the regenerating brain. The most severely affected neurons in Smed-tcf1(RNAi) animals were the dorsal GABAergic neurons, which failed to regenerate, leading to an inability of the animals to phototaxis away from light. Together, Smed-tcf1 is a critical regulator, required to pattern the dorsal-lateral region of the regenerating planarian brain. Copyright © 2017 Elsevier Inc. All rights reserved.

GRG5/AES interacts with T-cell factor 4 (TCF4) and downregulates Wnt signaling in human cells and zebrafish embryos.

PubMed

Costa, Angela M Sousa; Pereira-Castro, Isabel; Ricardo, Elisabete; Spencer, Forrest; Fisher, Shannon; da Costa, Luís Teixeira

2013-01-01

Transcriptional control by TCF/LEF proteins is crucial in key developmental processes such as embryo polarity, tissue architecture and cell fate determination. TCFs associate with β-catenin to activate transcription in the presence of Wnt signaling, but in its absence act as repressors together with Groucho-family proteins (GRGs). TCF4 is critical in vertebrate intestinal epithelium, where TCF4-β-catenin complexes are necessary for the maintenance of a proliferative compartment, and their abnormal formation initiates tumorigenesis. However, the extent of TCF4-GRG complexes' roles in development and the mechanisms by which they repress transcription are not completely understood. Here we characterize the interaction between TCF4 and GRG5/AES, a Groucho family member whose functional relationship with TCFs has been controversial. We map the core GRG interaction region in TCF4 to a 111-amino acid fragment and show that, in contrast to other GRGs, GRG5/AES-binding specifically depends on a 4-amino acid motif (LVPQ) present only in TCF3 and some TCF4 isoforms. We further demonstrate that GRG5/AES represses Wnt-mediated transcription both in human cells and zebrafish embryos. Importantly, we provide the first evidence of an inherent repressive function of GRG5/AES in dorsal-ventral patterning during early zebrafish embryogenesis. These results improve our understanding of TCF-GRG interactions, have significant implications for models of transcriptional repression by TCF-GRG complexes, and lay the groundwork for in depth direct assessment of the potential role of Groucho-family proteins in both normal and abnormal development.

GRG5/AES Interacts with T-Cell Factor 4 (TCF4) and Downregulates Wnt Signaling in Human Cells and Zebrafish Embryos

PubMed Central

Costa, Ângela M. Sousa; Pereira-Castro, Isabel; Ricardo, Elisabete; Spencer, Forrest; Fisher, Shannon; da Costa, Luís Teixeira

2013-01-01

Transcriptional control by TCF/LEF proteins is crucial in key developmental processes such as embryo polarity, tissue architecture and cell fate determination. TCFs associate with β-catenin to activate transcription in the presence of Wnt signaling, but in its absence act as repressors together with Groucho-family proteins (GRGs). TCF4 is critical in vertebrate intestinal epithelium, where TCF4-β-catenin complexes are necessary for the maintenance of a proliferative compartment, and their abnormal formation initiates tumorigenesis. However, the extent of TCF4-GRG complexes’ roles in development and the mechanisms by which they repress transcription are not completely understood. Here we characterize the interaction between TCF4 and GRG5/AES, a Groucho family member whose functional relationship with TCFs has been controversial. We map the core GRG interaction region in TCF4 to a 111-amino acid fragment and show that, in contrast to other GRGs, GRG5/AES-binding specifically depends on a 4-amino acid motif (LVPQ) present only in TCF3 and some TCF4 isoforms. We further demonstrate that GRG5/AES represses Wnt-mediated transcription both in human cells and zebrafish embryos. Importantly, we provide the first evidence of an inherent repressive function of GRG5/AES in dorsal-ventral patterning during early zebrafish embryogenesis. These results improve our understanding of TCF-GRG interactions, have significant implications for models of transcriptional repression by TCF-GRG complexes, and lay the groundwork for in depth direct assessment of the potential role of Groucho-family proteins in both normal and abnormal development. PMID:23840876

Induction of c-fos expression through JNK-mediated TCF/Elk-1 phosphorylation.

PubMed Central

Cavigelli, M; Dolfi, F; Claret, F X; Karin, M

1995-01-01

Growth factors induce c-fos transcription by stimulating phosphorylation of transcription factor TCF/Elk-1, which binds to the serum response element (SRE). Under such conditions Elk-1 could be phosphorylated by the mitogen-activated protein kinases (MAPKs) ERK1 and ERK2. However, c-fos transcription and SRE activity are also induced by stimuli, such as UV irradiation and activation of the protein kinase MEKK1, that cause only an insignificant increase in ERK1/2 activity. However, both of these stimuli strongly activate two other MAPKs, JNK1 and JNK2, and stimulate Elk-1 transcriptional activity and phosphorylation. We find that the JNKs are the predominant Elk-1 activation domain kinases in extracts of UV-irradiated cells and that immunopurified JNK1/2 phosphorylate Elk-1 on the same major sites recognized by ERK1/2, that potentiate its transcriptional activity. Finally, we show that UV irradiation, but not serum or phorbol esters, stimulate translocation of JNK1 to the nucleus. As Elk-1 is most likely phosphorylated while bound to the c-fos promoter, these results suggest that UV irradiation and MEKK1 activation stimulate TCF/Elk-1 activity through JNK activation, while growth factors induce c-fos through ERK activation. Images PMID:8846788

Adenomatous polyposis coli protein (APC)-independent regulation of beta-catenin/Tcf-4 mediated transcription in intestinal cells.

PubMed Central

Baulida, J; Batlle, E; García De Herreros, A

1999-01-01

Alterations in the transcriptional activity of the beta-catenin-Tcf complex have been associated with the earlier stages of colonic transformation. We show here that the activation of protein kinase C by the phorbol ester PMA in several intestinal cell lines increases the levels of beta-catenin detected in the nucleus and augments the transcriptional activity mediated by beta-catenin. The response to PMA was not related to modifications in the cytosolic levels of beta-catenin and was observed not only in cells with wild-type adenomatous polyposis coli protein (APC) but also in APC-deficient cells. Binding assays in vitro revealed that PMA facilitates the interaction of the beta-catenin with the nuclear structure. Our results therefore show that beta-catenin-mediated transcription can be regulated independently of the presence of APC. PMID:10567241

Wnt-Mediated Repression via Bipartite DNA Recognition by TCF in the Drosophila Hematopoietic System

PubMed Central

Zhang, Chen U.; Blauwkamp, Timothy A.; Burby, Peter E.; Cadigan, Ken M.

2014-01-01

The Wnt/β-catenin signaling pathway plays many important roles in animal development, tissue homeostasis and human disease. Transcription factors of the TCF family mediate many Wnt transcriptional responses, promoting signal-dependent activation or repression of target gene expression. The mechanism of this specificity is poorly understood. Previously, we demonstrated that for activated targets in Drosophila, TCF/Pangolin (the fly TCF) recognizes regulatory DNA through two DNA binding domains, with the High Mobility Group (HMG) domain binding HMG sites and the adjacent C-clamp domain binding Helper sites. Here, we report that TCF/Pangolin utilizes a similar bipartite mechanism to recognize and regulate several Wnt-repressed targets, but through HMG and Helper sites whose sequences are distinct from those found in activated targets. The type of HMG and Helper sites is sufficient to direct activation or repression of Wnt regulated cis-regulatory modules, and protease digestion studies suggest that TCF/Pangolin adopts distinct conformations when bound to either HMG-Helper site pair. This repressive mechanism occurs in the fly lymph gland, the larval hematopoietic organ, where Wnt/β-catenin signaling controls prohemocytic differentiation. Our study provides a paradigm for direct repression of target gene expression by Wnt/β-catenin signaling and allosteric regulation of a transcription factor by DNA. PMID:25144371

Association of TCF7L2 Gene Polymorphisms with Reduced Acute Insulin Response in Hispanic Americans

PubMed Central

Palmer, Nicholette D.; Lehtinen, Allison B.; Langefeld, Carl D.; Campbell, Joel K.; Haffner, Steven M.; Norris, Jill M.; Bergman, Richard N.; Goodarzi, Mark O.; Rotter, Jerome I.; Bowden, Donald W.

2008-01-01

Context: Genetic variation at the transcription factor 7-like 2 locus has been linked to type 2 diabetes in predominantly European-derived populations. The biological basis of these associations remains to be determined. Objective: The objective of this study was to evaluate previously associated variants for association with measures of glucose homeostasis in Hispanic-Americans and African-Americans and determine the biological mechanism(s) through which these variants exert their effect. Design: This study was the Insulin Resistance Atherosclerosis Family Study (IRAS-FS). Setting: The IRAS-FS is a community-based study of Hispanic-Americans (San Antonio, TX, and San Luis Valley, CO) and African-Americans (Los Angeles, CA). Participants: A total of 1040 Hispanic-American and 500 African-American individuals from the IRAS-FS formed the basis of this study. Main Outcomes Measures(s): The primary glucose homeostasis phenotypes of interest in this study were derived from the frequently sampled iv glucose tolerance test and include insulin sensitivity, acute insulin response, and disposition index. Results: In Hispanic-Americans, significant evidence of association was observed between single-nucleotide polymorphisms rs7903146 and rs112255372 with reduced insulin secretion as measured by acute insulin response and adjusted for the degree of insulin sensitivity (P = 0.032 and 0.036, respectively). Other quantitative measures, e.g. insulin sensitivity or disposition index, were not associated with the single nucleotide polymorphisms examined. In African-Americans there was no evidence of association observed. Conclusions: These results suggest that transcription factor 7-like 2 variants could play a role in the pathogenesis of type 2 diabetes in the Hispanic-American population through a mechanism involving insulin secretion. PMID:17971425

Association of TCF7L2 gene polymorphisms with reduced acute insulin response in Hispanic Americans.

PubMed

Palmer, Nicholette D; Lehtinen, Allison B; Langefeld, Carl D; Campbell, Joel K; Haffner, Steven M; Norris, Jill M; Bergman, Richard N; Goodarzi, Mark O; Rotter, Jerome I; Bowden, Donald W

2008-01-01

Genetic variation at the transcription factor 7-like 2 locus has been linked to type 2 diabetes in predominantly European-derived populations. The biological basis of these associations remains to be determined. The objective of this study was to evaluate previously associated variants for association with measures of glucose homeostasis in Hispanic-Americans and African-Americans and determine the biological mechanism(s) through which these variants exert their effect. This study was the Insulin Resistance Atherosclerosis Family Study (IRAS-FS). The IRAS-FS is a community-based study of Hispanic-Americans (San Antonio, TX, and San Luis Valley, CO) and African-Americans (Los Angeles, CA). A total of 1040 Hispanic-American and 500 African-American individuals from the IRAS-FS formed the basis of this study. MAIN OUTCOMES MEASURES(S): The primary glucose homeostasis phenotypes of interest in this study were derived from the frequently sampled iv glucose tolerance test and include insulin sensitivity, acute insulin response, and disposition index. In Hispanic-Americans, significant evidence of association was observed between single-nucleotide polymorphisms rs7903146 and rs112255372 with reduced insulin secretion as measured by acute insulin response and adjusted for the degree of insulin sensitivity (P = 0.032 and 0.036, respectively). Other quantitative measures, e.g. insulin sensitivity or disposition index, were not associated with the single nucleotide polymorphisms examined. In African-Americans there was no evidence of association observed. These results suggest that transcription factor 7-like 2 variants could play a role in the pathogenesis of type 2 diabetes in the Hispanic-American population through a mechanism involving insulin secretion.

The Arabidopsis RCC1 Family Protein TCF1 Regulates Freezing Tolerance and Cold Acclimation through Modulating Lignin Biosynthesis

PubMed Central

Jenkins, Gareth I.; Wang, Shuangfeng; Shang, Zhonglin; Shi, Yiting; Yang, Shuhua; Li, Xia

2015-01-01

Abstract Cell water permeability and cell wall properties are critical to survival of plant cells during freezing, however the underlying molecular mechanisms remain elusive. Here, we report that a specifically cold-induced nuclear protein, Tolerant to Chilling and Freezing 1 (TCF1), interacts with histones H3 and H4 and associates with chromatin containing a target gene, BLUE-COPPER-BINDING PROTEIN (BCB), encoding a glycosylphosphatidylinositol-anchored protein that regulates lignin biosynthesis. Loss of TCF1 function leads to reduced BCB transcription through affecting H3K4me2 and H3K27me3 levels within the BCB gene, resulting in reduced lignin content and enhanced freezing tolerance. Furthermore, plants with knocked-down BCB expression (amiRNA-BCB) under cold acclimation had reduced lignin accumulation and increased freezing tolerance. The pal1pal2 double mutant (lignin content reduced by 30% compared with WT) also showed the freezing tolerant phenotype, and TCF1 and BCB act upstream of PALs to regulate lignin content. In addition, TCF1 acts independently of the CBF (C-repeat binding factor) pathway. Our findings delineate a novel molecular pathway linking the TCF1-mediated cold-specific transcriptional program to lignin biosynthesis, thus achieving cell wall remodeling with increased freezing tolerance. PMID:26393916

CCAT2, a novel noncoding RNA mapping to 8q24, underlies metastatic progression and chromosomal instability in colon cancer

PubMed Central

Ling, Hui; Spizzo, Riccardo; Atlasi, Yaser; Nicoloso, Milena; Shimizu, Masayoshi; Redis, Roxana S.; Nishida, Naohiro; Gafà, Roberta; Song, Jian; Guo, Zhiyi; Ivan, Cristina; Barbarotto, Elisa; De Vries, Ingrid; Zhang, Xinna; Ferracin, Manuela; Churchman, Mike; van Galen, Janneke F.; Beverloo, Berna H.; Shariati, Maryam; Haderk, Franziska; Estecio, Marcos R.; Garcia-Manero, Guillermo; Patijn, Gijs A.; Gotley, David C.; Bhardwaj, Vikas; Shureiqi, Imad; Sen, Subrata; Multani, Asha S.; Welsh, James; Yamamoto, Ken; Taniguchi, Itsuki; Song, Min-Ae; Gallinger, Steven; Casey, Graham; Thibodeau, Stephen N.; Le Marchand, Loïc; Tiirikainen, Maarit; Mani, Sendurai A.; Zhang, Wei; Davuluri, Ramana V.; Mimori, Koshi; Mori, Masaki; Sieuwerts, Anieta M.; Martens, John W.M.; Tomlinson, Ian; Negrini, Massimo; Berindan-Neagoe, Ioana; Foekens, John A.; Hamilton, Stanley R.; Lanza, Giovanni; Kopetz, Scott; Fodde, Riccardo; Calin, George A.

2013-01-01

The functional roles of SNPs within the 8q24 gene desert in the cancer phenotype are not yet well understood. Here, we report that CCAT2, a novel long noncoding RNA transcript (lncRNA) encompassing the rs6983267 SNP, is highly overexpressed in microsatellite-stable colorectal cancer and promotes tumor growth, metastasis, and chromosomal instability. We demonstrate that MYC, miR–17–5p, and miR–20a are up-regulated by CCAT2 through TCF7L2-mediated transcriptional regulation. We further identify the physical interaction between CCAT2 and TCF7L2 resulting in an enhancement of WNT signaling activity. We show that CCAT2 is itself a WNT downstream target, which suggests the existence of a feedback loop. Finally, we demonstrate that the SNP status affects CCAT2 expression and the risk allele G produces more CCAT2 transcript. Our results support a new mechanism of MYC and WNT regulation by the novel lncRNA CCAT2 in colorectal cancer pathogenesis, and provide an alternative explanation of the SNP-conferred cancer risk. PMID:23796952

Tcf19 is a novel islet factor necessary for proliferation and survival in the INS-1 β-cell line

PubMed Central

Krautkramer, Kimberly A.; Linnemann, Amelia K.; Fontaine, Danielle A.; Whillock, Amy L.; Harris, Ted W.; Schleis, Gregory J.; Truchan, Nathan A.; Marty-Santos, Leilani; Lavine, Jeremy A.; Cleaver, Ondine; Kimple, Michelle E.

2013-01-01

Recently, a novel type 1 diabetes association locus was identified at human chromosome 6p31.3, and transcription factor 19 (TCF19) is a likely causal gene. Little is known about Tcf19, and we now show that it plays a role in both proliferation and apoptosis in insulinoma cells. Tcf19 is expressed in mouse and human islets, with increasing mRNA expression in nondiabetic obesity. The expression of Tcf19 is correlated with β-cell mass expansion, suggesting that it may be a transcriptional regulator of β-cell mass. Increasing proliferation and decreasing apoptotic cell death are two strategies to increase pancreatic β-cell mass and prevent or delay diabetes. siRNA-mediated knockdown of Tcf19 in the INS-1 insulinoma cell line, a β-cell model, results in a decrease in proliferation and an increase in apoptosis. There was a significant reduction in the expression of numerous cell cycle genes from the late G1 phase through the M phase, and cells were arrested at the G1/S checkpoint. We also observed increased apoptosis and susceptibility to endoplasmic reticulum (ER) stress after Tcf19 knockdown. There was a reduction in expression of genes important for the maintenance of ER homeostasis (Bip, p58IPK, Edem1, and calreticulin) and an increase in proapoptotic genes (Bim, Bid, Nix, Gadd34, and Pdia2). Therefore, Tcf19 is necessary for both proliferation and survival and is a novel regulator of these pathways. PMID:23860123

Epigenetic deregulation of TCF21 inhibits metastasis suppressor KISS1 in metastatic melanoma.

PubMed

Arab, Khelifa; Smith, Laura T; Gast, Andreas; Weichenhan, Dieter; Huang, Joseph Po-Hsien; Claus, Rainer; Hielscher, Thomas; Espinosa, Allan V; Ringel, Matthew D; Morrison, Carl D; Schadendorf, Dirk; Kumar, Rajiv; Plass, Christoph

2011-10-01

Metastatic melanoma is a fatal disease due to the lack of successful therapies and biomarkers for early detection and its incidence has been increasing. Genetic studies have defined recurrent chromosomal aberrations, suggesting the location of either tumor suppressor genes or oncogenes. Transcription factor 21 (TCF21) belongs to the class A of the basic helix-loop-helix family with reported functions in early lung and kidney development as well as tumor suppressor function in the malignancies of the lung and head and neck. In this study, we combined quantitative DNA methylation analysis in patient biopsies and in their derived cell lines to demonstrate that TCF21 expression is downregulated in metastatic melanoma by promoter hypermethylation and TCF21 promoter DNA methylation is correlated with decreased survival in metastatic skin melanoma patients. In addition, the chromosomal location of TCF21 on 6q23-q24 coincides with the location of a postulated metastasis suppressor in melanoma. Functionally, TCF21 binds the promoter of the melanoma metastasis-suppressing gene, KiSS1, and enhances its gene expression through interaction with E12, a TCF3 isoform and with TCF12. Loss of TCF21 expression results in loss of KISS1 expression through loss of direct interaction of TCF21 at the KISS1 promoter. Finally, overexpression of TCF21 inhibits motility of C8161 melanoma cells. These data suggest that epigenetic downregulation of TCF21 is functionally involved in melanoma progression and that it may serve as a biomarker for aggressive tumor behavior.

Genomic response to Wnt signalling is highly context-dependent - Evidence from DNA microarray and chromatin immunoprecipitation screens of Wnt/TCF targets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Railo, Antti; Pajunen, Antti; Itaeranta, Petri

2009-10-01

Wnt proteins are important regulators of embryonic development, and dysregulated Wnt signalling is involved in the oncogenesis of several human cancers. Our knowledge of the downstream target genes is limited, however. We used a chromatin immunoprecipitation-based assay to isolate and characterize the actual gene segments through which Wnt-activatable transcription factors, TCFs, regulate transcription and an Affymetrix microarray analysis to study the global transcriptional response to the Wnt3a ligand. The anti-{beta}-catenin immunoprecipitation of DNA-protein complexes from mouse NIH3T3 fibroblasts expressing a fusion protein of {beta}-catenin and TCF7 resulted in the identification of 92 genes as putative TCF targets. GeneChip assays ofmore » gene expression performed on NIH3T3 cells and the rat pheochromocytoma cell line PC12 revealed 355 genes in NIH3T3 and 129 genes in the PC12 cells with marked changes in expression after Wnt3a stimulus. Only 2 Wnt-regulated genes were shared by both cell lines. Surprisingly, Disabled-2 was the only gene identified by the chromatin immunoprecipitation approach that displayed a marked change in expression in the GeneChip assay. Taken together, our approaches give an insight into the complex context-dependent nature of Wnt pathway transcriptional responses and identify Disabled-2 as a potential new direct target for Wnt signalling.« less

TCF21 and the environmental sensor aryl-hydrocarbon receptor cooperate to activate a pro-inflammatory gene expression program in coronary artery smooth muscle cells

PubMed Central

Nguyen, Trieu; Iyer, Dharini; Liu, Boxiang; Wang, Ting; Sazonova, Olga; Matic, Ljubica Perisic; Maegdefessel, Lars; Quertermous, Thomas

2017-01-01

Both environmental factors and genetic loci have been associated with coronary artery disease (CAD), however gene-gene and gene-environment interactions that might identify molecular mechanisms of risk are not easily studied by human genetic approaches. We have previously identified the transcription factor TCF21 as the causal CAD gene at 6q23.2 and characterized its downstream transcriptional network that is enriched for CAD GWAS genes. Here we investigate the hypothesis that TCF21 interacts with a downstream target gene, the aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor that mediates the cellular response to environmental contaminants, including dioxin and polycyclic aromatic hydrocarbons (e.g., tobacco smoke). Perturbation of TCF21 expression in human coronary artery smooth muscle cells (HCASMC) revealed that TCF21 promotes expression of AHR, its heterodimerization partner ARNT, and cooperates with these factors to upregulate a number of inflammatory downstream disease related genes including IL1A, MMP1, and CYP1A1. TCF21 was shown to bind in AHR, ARNT and downstream target gene loci, and co-localization was noted for AHR-ARNT and TCF21 binding sites genome-wide in regions of HCASMC open chromatin. These regions of co-localization were found to be enriched for GWAS signals associated with cardio-metabolic as well as chronic inflammatory disease phenotypes. Finally, we show that similar to TCF21, AHR gene expression is increased in atherosclerotic lesions in mice in vivo using laser capture microdissection, and AHR protein is localized in human carotid atherosclerotic lesions where it is associated with protein kinases with a critical role in innate immune response. These data suggest that TCF21 can cooperate with AHR to activate an inflammatory gene expression program that is exacerbated by environmental stimuli, and may contribute to the overall risk for CAD. PMID:28481916

Investigation of the role of TCF4 rare sequence variants in schizophrenia.

PubMed

Basmanav, F Buket; Forstner, Andreas J; Fier, Heide; Herms, Stefan; Meier, Sandra; Degenhardt, Franziska; Hoffmann, Per; Barth, Sandra; Fricker, Nadine; Strohmaier, Jana; Witt, Stephanie H; Ludwig, Michael; Schmael, Christine; Moebus, Susanne; Maier, Wolfgang; Mössner, Rainald; Rujescu, Dan; Rietschel, Marcella; Lange, Christoph; Nöthen, Markus M; Cichon, Sven

2015-07-01

Transcription factor 4 (TCF4) is one of the most robust of all reported schizophrenia risk loci and is supported by several genetic and functional lines of evidence. While numerous studies have implicated common genetic variation at TCF4 in schizophrenia risk, the role of rare, small-sized variants at this locus-such as single nucleotide variants and short indels which are below the resolution of chip-based arrays requires further exploration. The aim of the present study was to investigate the association between rare TCF4 sequence variants and schizophrenia. Exon-targeted resequencing was performed in 190 German schizophrenia patients. Six rare variants at the coding exons and flanking sequences of the TCF4 gene were identified, including two missense variants and one splice site variant. These six variants were then pooled with nine additional rare variants identified in 379 European participants of the 1000 Genomes Project, and all 15 variants were genotyped in an independent German sample (n = 1,808 patients; n = 2,261 controls). These data were then analyzed using six statistical methods developed for the association analysis of rare variants. No significant association (P < 0.05) was found. However, the results from our association and power analyses suggest that further research into the possible involvement of rare TCF4 sequence variants in schizophrenia risk is warranted by the assessment of larger cohorts with higher statistical power to identify rare variant associations. © 2015 Wiley Periodicals, Inc.

De novo nonsense and frameshift variants of TCF20 in individuals with intellectual disability and postnatal overgrowth.

PubMed

Schäfgen, Johanna; Cremer, Kirsten; Becker, Jessica; Wieland, Thomas; Zink, Alexander M; Kim, Sarah; Windheuser, Isabelle C; Kreiß, Martina; Aretz, Stefan; Strom, Tim M; Wieczorek, Dagmar; Engels, Hartmut

2016-12-01

Recently, germline variants of the transcriptional co-regulator gene TCF20 have been implicated in the aetiology of autism spectrum disorders (ASD). However, the knowledge about the associated clinical picture remains fragmentary. In this study, two individuals with de novo TCF20 sequence variants were identified in a cohort of 313 individuals with intellectual disability of unknown aetiology, which was analysed by whole exome sequencing using a child-parent trio design. Both detected variants - one nonsense and one frameshift variant - were truncating. A comprehensive clinical characterisation of the patients yielded mild intellectual disability, postnatal tall stature and macrocephaly, obesity and muscular hypotonia as common clinical signs while ASD was only present in one proband. The present report begins to establish the clinical picture of individuals with de novo nonsense and frameshift variants of TCF20 which includes features such as proportionate overgrowth and muscular hypotonia. Furthermore, intellectual disability/developmental delay seems to be fully penetrant amongst known individuals with de novo nonsense and frameshift variants of TCF20, whereas ASD is shown to be incompletely penetrant. The transcriptional co-regulator gene TCF20 is hereby added to the growing number of genes implicated in the aetiology of both ASD and intellectual disability. Furthermore, such de novo variants of TCF20 may represent a novel differential diagnosis in the overgrowth syndrome spectrum.

Tcf4 transgenic female mice display delayed adaptation in an auditory latent inhibition paradigm.

PubMed

Brzózka, M M; Rossner, M J; de Hoz, L

2016-09-01

Schizophrenia (SZ) is a severe mental disorder affecting about 1 % of the human population. Patients show severe deficits in cognitive processing often characterized by an improper filtering of environmental stimuli. Independent genome-wide association studies confirmed a number of risk variants for SZ including several associated with the gene encoding the transcription factor 4 (TCF4). TCF4 is widely expressed in the central nervous system of mice and humans and seems to be important for brain development. Transgenic mice overexpressing murine Tcf4 (Tcf4tg) in the adult brain display cognitive impairments and sensorimotor gating disturbances. To address the question of whether increased Tcf4 gene dosage may affect cognitive flexibility in an auditory associative task, we tested latent inhibition (LI) in female Tcf4tg mice. LI is a widely accepted translational endophenotype of SZ and results from a maladaptive delay in switching a response to a previously unconditioned stimulus when this becomes conditioned. Using an Audiobox, we pre-exposed Tcf4tg mice and their wild-type littermates to either a 3- or a 12-kHz tone before conditioning them to a 12-kHz tone. Tcf4tg animals pre-exposed to a 12-kHz tone showed significantly delayed conditioning when the previously unconditioned tone became associated with an air puff. These results support findings that associate TCF4 dysfunction with cognitive inflexibility and improper filtering of sensory stimuli observed in SZ patients.

Contribution of type 2 diabetes associated loci in the Arabic population from Tunisia: a case-control study

PubMed Central

Ezzidi, Intissar; Mtiraoui, Nabil; Cauchi, Stéphane; Vaillant, Emmanuel; Dechaume, Aurélie; Chaieb, Molka; Kacem, Maha; Almawi, Wassim Y; Froguel, Philippe; Mahjoub, Touhami; Vaxillaire, Martine

2009-01-01

Background Candidate gene and genome-wide association studies have both reproducibly identified several common Single Nucleotide Polymorphisms (SNPs) that confer type 2 diabetes (T2D) risk in European populations. Our aim was to evaluate the contribution to T2D of five of these established T2D-associated loci in the Arabic population from Tunisia. Methods A case-control design comprising 884 type 2 diabetic patients and 513 control subjects living in the East-Center of Tunisia was used to analyze the contribution to T2D of the following SNPs: E23K in KCNJ11/Kir6.2, K121Q in ENPP1, the -30G/A variant in the pancreatic β-cell specific promoter of Glucokinase, rs7903146 in TCF7L2 encoding transcription factor 7-like2, and rs7923837 in HHEX encoding the homeobox, hematopoietically expressed transcription factor. Results TCF7L2-rs7903146 T allele increased susceptibility to T2D (OR = 1.25 [1.06–1.47], P = 0.006) in our study population. This risk was 56% higher among subjects carrying the TT genotype in comparison to those carrying the CC genotype (OR = 1.56 [1.13–2.16], P = 0.002). No allelic or genotypic association with T2D was detected for the other studied polymorphisms. Conclusion In the Tunisian population, TCF7L2-rs7903146 T allele confers an increased risk of developing T2D as previously reported in the European population and many other ethnic groups. In contrast, none of the other tested SNPs that influence T2D risk in the European population was associated with T2D in the Tunisian Arabic population. An insufficient power to detect minor allelic contributions or genetic heterogeneity of T2D between different ethnic groups can explain these findings. PMID:19368707

Generation of thalamic neurons from mouse embryonic stem cells.

PubMed

Shiraishi, Atsushi; Muguruma, Keiko; Sasai, Yoshiki

2017-04-01

The thalamus is a diencephalic structure that plays crucial roles in relaying and modulating sensory and motor information to the neocortex. The thalamus develops in the dorsal part of the neural tube at the level of the caudal forebrain. However, the molecular mechanisms that are essential for thalamic differentiation are still unknown. Here, we have succeeded in generating thalamic neurons from mouse embryonic stem cells (mESCs) by modifying the default method that induces the most-anterior neural type in self-organizing culture. A low concentration of the caudalizing factor insulin and a MAPK/ERK kinase inhibitor enhanced the expression of the caudal forebrain markers Otx2 and Pax6. BMP7 promoted an increase in thalamic precursors such as Tcf7l2 + /Gbx2 + and Tcf7l2 + /Olig3 + cells. mESC thalamic precursors began to express the glutamate transporter vGlut2 and the axon-specific marker VGF, similar to mature projection neurons. The mESC thalamic neurons extended their axons to cortical layers in both organotypic culture and subcortical transplantation. Thus, we have identified the minimum elements sufficient for in vitro generation of thalamic neurons. These findings expand our knowledge of thalamic development. © 2017. Published by The Company of Biologists Ltd.

Transcription factor 19 interacts with histone 3 lysine 4 trimethylation and controls gluconeogenesis via the nucleosome-remodeling-deacetylase complex.

PubMed

Sen, Sabyasachi; Sanyal, Sulagna; Srivastava, Dushyant Kumar; Dasgupta, Dipak; Roy, Siddhartha; Das, Chandrima

2017-12-15

Transcription factor 19 (TCF19) has been reported as a type 1 diabetes-associated locus involved in maintenance of pancreatic β cells through a fine-tuned regulation of cell proliferation and apoptosis. TCF19 also exhibits genomic association with type 2 diabetes, although the precise molecular mechanism remains unknown. It harbors both a plant homeodomain and a forkhead-associated domain implicated in epigenetic recognition and gene regulation, a phenomenon that has remained unexplored. Here, we show that TCF19 selectively interacts with histone 3 lysine 4 trimethylation through its plant homeodomain finger. Knocking down TCF19 under high-glucose conditions affected many metabolic processes, including gluconeogenesis. We found that TCF19 overexpression represses de novo glucose production in HepG2 cells. The transcriptional repression of key genes, induced by TCF19, coincided with NuRD (nucleosome-remodeling-deacetylase) complex recruitment to the promoters of these genes. TCF19 interacted with CHD4 (chromodomain helicase DNA-binding protein 4), which is a part of the NuRD complex, in a glucose concentration-independent manner. In summary, our results show that TCF19 interacts with an active transcription mark and recruits a co-repressor complex to regulate gluconeogenic gene expression in HepG2 cells. Our study offers critical insights into the molecular mechanisms of transcriptional regulation of gluconeogenesis and into the roles of chromatin readers in metabolic homeostasis. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Down-regulation of TCF21 by hypermethylation induces cell proliferation, migration and invasion in colorectal cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dai, Youyi; Duan, Huaxin; The First Affiliated Hospital of Hunan Normal University

Epigenetic alteration induced loss function of the transcription factor 21 (TCF21) has been associated with different types of human cancers. However, the epigenetic regulation and molecular functions of TCF21 in colorectal cancer (CRC) remain unknown. In this study, TCF21 expression levels and methylation status of its promoter region in CRC cell lines (n = 5) and CRC tissues (n = 151) as well as normal colorectal mucosa (n = 30) were assessed by RTq-PCR and methylation analysis (methylation specific PCR, MSP and bisulfite sequencing PCR, BSP), respectively. The cellular functions of TCF21 on CRC cell proliferation, apoptosis, invasion and migration were investigated in vitro. Our data revealedmore » that TCF21 was frequently silenced by promoter hypermethylation in both tested CRC cell lines and primary CRC, and correlation analysis between methylation status and clinicopathologic parameters found that TCF21 methylation was significantly correlated with lymph node invasion (P = 0.013), while no significant correlation was found in other parameters. In addition, demethylation treatment resulted in re-expression of TCF21 in CRC cell lines, and cellular function experiments revealed that restoration of TCF21 inhibited CRC cell proliferation, promoted apoptosis and suppressed cell invasion and migration, suggesting that TCF21 may function as a tumor suppressor gene, which is downregulated through promoter hypermethylation in CRC development. - Highlights: • TCF21 was frequently silenced by promoter DNA methylation in CRC cells. • TCF21 was frequently methylated in primary CRC and significantly correlated with metastasis. • Restoration of TCF21 promotes cell apoptosis of CRC cells. • Restoration of TCF21 inhibits cell invasion and migration of CRC cells.« less

5-Hydroxymethylcytosine in E-box motifs ACAT|GTG and ACAC|GTG increases DNA-binding of the B-HLH transcription factor TCF4.

PubMed

Khund-Sayeed, Syed; He, Ximiao; Holzberg, Timothy; Wang, Jun; Rajagopal, Divya; Upadhyay, Shriyash; Durell, Stewart R; Mukherjee, Sanjit; Weirauch, Matthew T; Rose, Robert; Vinson, Charles

2016-09-12

We evaluated DNA binding of the B-HLH family members TCF4 and USF1 using protein binding microarrays (PBMs) containing double-stranded DNA probes with cytosine on both strands or 5-methylcytosine (5mC) or 5-hydroxymethylcytosine (5hmC) on one DNA strand and cytosine on the second strand. TCF4 preferentially bound the E-box motif (CAN|NTG) with strongest binding to the 8-mer CAG|GTGGT. 5mC uniformly decreases DNA binding of both TCF4 and USF1. The bulkier 5hmC also inhibited USF1 binding to DNA. In contrast, 5hmC dramatically enhanced TCF4 binding to E-box motifs ACAT|GTG and ACAC|GTG, being better bound than any 8-mer containing cytosine. Examination of X-ray structures of the closely related TCF3 and USF1 bound to DNA suggests TCF3 can undergo a conformational shift to preferentially bind to 5hmC while the USF1 basic region is bulkier and rigid precluding a conformation shift to bind 5hmC. These results greatly expand the regulatory DNA sequence landscape bound by TCF4.

Stringent Control of NFE2L3 (Nuclear Factor, Erythroid 2-Like 3; NRF3) Protein Degradation by FBW7 (F-box/WD Repeat-containing Protein 7) and Glycogen Synthase Kinase 3 (GSK3)*

PubMed Central

Kannan, Meenakshi B.; Dodard-Friedman, Isadore; Blank, Volker

2015-01-01

The NFE2L3 transcription factor has been implicated in various cellular processes, including carcinogenesis, stress response, differentiation, and inflammation. Previously it has been shown that NFE2L3 has a rapid turnover and is stabilized by proteasomal inhibitors. The mechanisms regulating the degradation of this protein have not been investigated. Here we report ubiquitination of NFE2L3 and demonstrate that F-box/WD repeat-containing protein 7 (FBW7 or FBWX7), a component of Skp1, Cullin 1, F-box containing complex (SCF)-type E3 ligase, is the E3 ligase mediating the degradation of NFE2L3. We showed that FBW7 interacts with NFE2L3 and that dimerization of FBW7 is required for the degradation of the transcription factor. We also demonstrate that the kinase glycogen synthase kinase 3 (GSK3) mediates the FBW7-dependent ubiquitination of NFE2L3. We show phosphorylation of NFE2L3 by GSK3 and its significance in the regulation of NFE2L3 by the tumor suppressor FBW7. FBW7 abrogated NFE2L3-mediated repression of the NAD(P)H:quinone oxidoreductase 1 (NQO1) gene antioxidant response element (ARE). Our findings reveal FBW7 and GSK3 as novel regulators of the NFE2L3 transcription factor and a potential mechanism by which FBW7 might regulate detoxification and the cellular response to stress. PMID:26306035

Efficacy and tolerability of chemotherapy with modified dose-dense TCF regimen (TCF-dd) in locally advanced or metastatic gastric cancer: final results of a phase II trial.

PubMed

Tomasello, Gianluca; Liguigli, Wanda; Poli, Rossana; Lazzarelli, Silvia; Brighenti, Matteo; Negri, Federica; Curti, Alessandra; Martinotti, Mario; Olivetti, Lucio; Rovatti, Massimo; Donati, Gianvito; Passalacqua, Rodolfo

2014-10-01

We previously studied a dose-dense TCF (TCF-dd) regimen demonstrating its feasibility and an activity comparable to epirubicin-based chemotherapy and TCF q3w in terms of overall survival and time to progression (TTP). We report here the final results of a phase II study of chemotherapy with a modified TCF-dd regimen in locally advanced or metastatic gastric cancer (MGC). Patients with histologically confirmed measurable MGC, not previously treated for advanced disease, received docetaxel 70 mg/m(2) day 1, cisplatin 60 mg/m(2) day 1, l-folinic acid 100 mg/m(2) days 1 and 2, followed by 5-fluorouracil (5-FU) 400 mg/m(2) bolus days 1 and 2, and then 600 mg/m(2) as a 22-h continuous infusion days 1 and 2, every 14 days, plus pegfilgrastim 6 mg on day 3. Patients aged ≥65 years received the same schedule with a dose reduction of 30 %. Study duration: December 2007-November 2010. Forty-six consecutive patients were enrolled (78 % male, 22 % female; median age, 66 years, range, 38-76 years; ECOG PS: 0, 48 %, 1, 46 %). Primary endpoint was overall response rate (ORR). A median of four cycles (range, one to six) was administered. Forty-three patients were evaluated for response (93.5 %) and all for toxicity: 3 complete response (CR), 25 partial response (PR), 10 stable disease (SD), and 5 progressive disease (PD) were observed, for an ORR by intention to treat (ITT) of 61 % (95 % CI 47-75). Median overall survival (OS) was 17.63 months (95 % CI, 13.67-20.67); median progression-free survival was 8.9 months (95 % CI, 6.5-13.4). Twenty-one patients (46.0 %) were treated at full doses without any delay, thus respecting the dose-dense criterion. Most frequent grade 3-4 toxicities were neutropenia (20 %), leukopenia (4 %), thrombocytopenia (2 %), anemia (2 %), febrile neutropenia (6 %), asthenia (22 %), diarrhea (4 %), nausea/vomiting (11 %), and hypokalemia (6 %). Overall, TCF-dd was shown to be safe. The TCF-dd regimen in locally advanced or MGC

TCF1 and LEF1 act as T-cell intrinsic HTLV-1 antagonists by targeting Tax.

PubMed

Ma, Guangyong; Yasunaga, Jun-ichirou; Akari, Hirofumi; Matsuoka, Masao

2015-02-17

Human T-cell leukemia virus type 1 (HTLV-1) is a delta-type retrovirus that induces malignant and inflammatory diseases during its long persistence in vivo. HTLV-1 can infect various kinds of cells; however, HTLV-1 provirus is predominantly found in peripheral CD4 T cells in vivo. Here we find that TCF1 and LEF1, two Wnt transcription factors that are specifically expressed in T cells, inhibit viral replication through antagonizing Tax functions. TCF1 and LEF1 can each interact with Tax and inhibit Tax-dependent viral expression and activation of NF-κB and AP-1. As a result, HTLV-1 replication is suppressed in the presence of either TCF1 or LEF1. On the other hand, T-cell activation suppresses the expression of both TCF1 and LEF1, and this suppression enables Tax to function as an activator. We analyzed the thymus of a simian T-cell leukemia virus type 1 (STLV-1) infected Japanese macaque, and found a negative correlation between proviral load and TCF1/LEF1 expression in various T-cell subsets, supporting the idea that TCF1 and LEF1 negatively regulate HTLV-1 replication and the proliferation of infected cells. Thus, this study identified TCF1 and LEF1 as Tax antagonistic factors in vivo, a fact which may critically influence the peripheral T-cell tropism of this virus.

The Functional SNPs in the 5’ Regulatory Region of the Porcine PPARD Gene Have Significant Association with Fat Deposition Traits

PubMed Central

Hu, Shanyao; Lin, Bin; Yan, Dechao; Xu, Zaiyan; Zhang, Zijun; Mao, Yuanliang; Mao, Huimin; Wang, Litong; Wang, Guoshui; Xiong, Yuanzhu; Zuo, Bo

2015-01-01

Peroxisome proliferator-activated receptor delta (PPARD) is a key regulator of lipid metabolism, insulin sensitivity, cell proliferation and differentiation. In this study, we identified two Single Nucleotide Polymorphisms (SNPs, g.1015 A>G and g.1018 T>C) constituting four haplotypes (GT, GC, AC and AT) in the 5’ regulatory region of porcine PPARD gene. Functional analysis of the four haplotypes showed that the transcriptional activity of the PPARD promoter fragment carrying haplotype AC was significantly lower than that of the other haplotypes in 3T3-L1, C2C12 and PK-15 cells, and haplotype AC had the lowest binding capacities to the nuclear extracts. Transcription factor 7-like 2 (TCF7L2) enhanced the transcription activities of promoter fragments of PPARD gene carrying haplotypes GT, GC and AT in C2C12 and 3T3-L1 cells, and increased the protein expression of PPARD gene in C2C12 myoblasts. TCF7L2 differentially bound to the four haplotypes, and the binding capacity of TCF7L2 to haplotype AC was the lowest. There were significant associations between -655A/G and fat deposition traits in three pig populations including the Large White × Meishan F2 pigs, France and American Large White pigs. Pigs with genotype GG had significantly higher expression of PPARD at both mRNA and protein level than those with genotype AG. These results strongly suggested that the SNPs in 5’ regulatory region of PPARD genes had significant impact on pig fat deposition traits. PMID:26599230

Expression of Prx1 and Tcf4 is decreased in the diaphragmatic muscle connective tissue of nitrofen-induced congenital diaphragmatic hernia.

PubMed

Takahashi, Toshiaki; Zimmer, Julia; Friedmacher, Florian; Puri, Prem

2016-12-01

Pleuroperitoneal folds (PPFs) are the source of the primordial diaphragm's muscle connective tissue (MCT), and developmental mutations have been shown to result in congenital diaphragmatic hernia (CDH). The protein paired-related homeobox 1 (Prx1) labels migrating PPF cells and stimulates expression of transcription factor 4 (Tcf4), a novel MCT marker that controls morphogenesis of the fetal diaphragm. We hypothesized that diaphragmatic Prx1 and Tcf4 expression is decreased in the nitrofen-induced CDH model. Time-mated rats were exposed to either nitrofen or vehicle on gestational day 9 (D9). Fetal diaphragms were microdissected on D13, D15, and D18, and divided into control and nitrofen-exposed specimens. Gene expression levels of Prx1 and Tcf4 were analyzed by qRT-PCR. Immunofluorescence double staining for Prx1 and Tcf4 was performed to evaluate protein expression and localization. Relative mRNA expression of Prx1 and Tcf4 was significantly downregulated in PPFs (D13), developing diaphragms (D15) and fully muscularized diaphragms (D18) of nitrofen-exposed fetuses compared to controls. Confocal laser scanning microscopy revealed markedly diminished Prx1 and Tcf4 expression in diaphragmatic MCT of nitrofen-exposed fetuses on D13, D15, and D18 compared to controls. Decreased expression of Prx1 and Tcf4 in the fetal diaphragm may cause defects in the PPF-derived MCT, leading to development of CDH in the nitrofen model. Level 2c (Centre for Evidence-Based Medicine, Oxford). Copyright © 2016 Elsevier Inc. All rights reserved.

Opposing Development of Cytotoxic and Follicular Helper CD4 T Cells Controlled by the TCF-1-Bcl6 Nexus.

PubMed

Donnarumma, Tiziano; Young, George R; Merkenschlager, Julia; Eksmond, Urszula; Bongard, Nadine; Nutt, Stephen L; Boyer, Claude; Dittmer, Ulf; Le-Trilling, Vu Thuy Khanh; Trilling, Mirko; Bayer, Wibke; Kassiotis, George

2016-11-01

CD4 + T cells develop distinct and often contrasting helper, regulatory, or cytotoxic activities. Typically a property of CD8 + T cells, granzyme-mediated cytotoxic T cell (CTL) potential is also exerted by CD4 + T cells. However, the conditions that induce CD4 + CTLs are not entirely understood. Using single-cell transcriptional profiling, we uncover a unique signature of Granzyme B (GzmB) + CD4 + CTLs, which distinguishes them from other CD4 + T helper (Th) cells, including Th1 cells, and strongly contrasts with the follicular helper T (Tfh) cell signature. The balance between CD4 + CTL and Tfh differentiation heavily depends on the class of infecting virus and is jointly regulated by the Tfh-related transcription factors Bcl6 and Tcf7 (encoding TCF-1) and by the expression of the inhibitory receptors PD-1 and LAG3. This unique profile of CD4 + CTLs offers targets for their study, and its antagonism by the Tfh program separates CD4 + T cells with either helper or killer functions. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Multi-level interactions between the nuclear receptor TRα1 and the WNT effectors β-catenin/Tcf4 in the intestinal epithelium.

PubMed

Sirakov, Maria; Skah, Seham; Lone, Imtiaz Nisar; Nadjar, Julien; Angelov, Dimitar; Plateroti, Michelina

2012-01-01

Intestinal homeostasis results from complex cross-regulation of signaling pathways; their alteration induces intestinal tumorigenesis. Previously, we found that the thyroid hormone nuclear receptor TRα1 activates and synergizes with the WNT pathway, inducing crypt cell proliferation and promoting tumorigenesis. Here, we investigated the mechanisms and implications of the cross-regulation between these two pathways in gut tumorigenesis in vivo and in vitro. We analyzed TRα1 and WNT target gene expression in healthy mucosae and tumors from mice overexpressing TRα1 in the intestinal epithelium in a WNT-activated genetic background (vil-TRα1/Apc mice). Interestingly, increased levels of β-catenin/Tcf4 complex in tumors from vil-TRα1/Apc mice blocked TRα1 transcriptional activity. This observation was confirmed in Caco2 cells, in which TRα1 functionality on a luciferase reporter-assay was reduced by the overexpression of β-catenin/Tcf4. Moreover, TRα1 physically interacted with β-catenin/Tcf4 in the nuclei of these cells. Using molecular approaches, we demonstrated that the binding of TRα1 to its DNA target sequences within the tumors was impaired, while it was newly recruited to WNT target genes. In conclusion, our observations strongly suggest that increased β-catenin/Tcf4 levels i) correlated with reduced TRα1 transcriptional activity on its target genes and, ii) were likely responsible for the shift of TRα1 binding on WNT targets. Together, these data suggest a novel mechanism for the tumor-promoting activity of the TRα1 nuclear receptor.

The γ-secretase cleavage product of Polycystin-1 regulates TCF and CHOP-mediated transcriptional activation through a p300-dependent mechanism

PubMed Central

Merrick, David; Chapin, Hannah; Baggs, Julie E.; Yu, Zhiheng; Somlo, Stefan; Sun, Zhaoxia; Hogenesch, John B.; Caplan, Michael

2011-01-01

Summary Mutations in Pkd1, encoding polycystin-1 (PC1), cause Autosomal Dominant Polycystic Kidney Disease (ADPKD). We show that the carboxy-terminal tail (CTT) of PC1 is released by γ-secretase-mediated cleavage and regulates the Wnt and CHOP pathways by binding the transcription factors TCF and CHOP, disrupting their interaction with the common transcriptional co-activator p300. Loss of PC1 causes increased proliferation and apoptosis, while reintroducing PC1-CTT into cultured Pkd1 null cells reestablishes normal growth rate, suppresses apoptosis, and prevents cyst formation. Inhibition of γ-secretase activity impairs the ability of PC1 to suppress growth and apoptosis, and leads to cyst formation in cultured renal epithelial cells. Expression of the PC1-CTT is sufficient to rescue the dorsal body curvature phenotype in zebrafish embryos resulting from either γ-secretase inhibition or suppression of Pkd1 expression. Thus, γ-secretase-dependent release of the PC1-CTT creates a protein fragment whose expression is sufficient to suppress ADPKD-related phenotypes in vitro and in vivo. PMID:22178500

WNT2B2 mRNA, up-regulated in primary gastric cancer, is a positive regulator of the WNT- beta-catenin-TCF signaling pathway.

PubMed

Katoh, M; Kirikoshi, H; Terasaki, H; Shiokawa, K

2001-12-21

Genetic alterations of WNT signaling molecules lead to carcinogenesis through activation of the beta-catenin-TCF signaling pathway. We have previously cloned and characterized WNT2B/WNT13 gene on human chromosome 1p13, which is homologous to proto-oncogene WNT2 on human chromosome 7q31. WNT2B1 and WNT2B2 mRNAs, generated from the WNT2B gene due to alternative splicing of the alternative promoter type, encode almost identical polypeptides with divergence in the N-terminal region. WNT2B2 mRNA rather than WNT2B1 mRNA is preferentially expressed in NT2 cells with the potential of neuronal differentiation. Here, we describe our investigations of expression of WNT2B mRNAs in various types of human primary cancer. Matched tumor/normal expression array analysis revealed that WNT2B mRNAs were significantly up-regulated in 2 of 8 cases of primary gastric cancer. WNT2B2 mRNA rather than WNT2B1 mRNA was found to be preferentially up-regulated in a case of primary gastric cancer (signet ring cell carcinoma). Function of WNT2B1 mRNA and that of WNT2B2 mRNA were investigated by using Xenopus axis duplication assay. Injection of synthetic WNT2B1 mRNA into the ventral marginal zone of fertilized Xenopus eggs at the 4-cell stage did not induce axis duplication. In contrast, ventral injection of synthetic WNT2B2 mRNA induced axis duplication in 90% of embryos (complete axis duplication, 24%). These results strongly suggest that WNT2B2 up-regulation in some cases of gastric cancer might lead to carcinogenesis through activation of the beta-catenin-TCF signaling pathway.

27-Hydroxycholesterol increases Myc protein stability via suppressing PP2A, SCP1 and FBW7 transcription in MCF-7 breast cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Li-Ming; Liang, Zi-Rui; Zhou, Ke-Ren

27-hydroxycholesterol (27-HC), the most abundant metabolite of cholesterol, is a risk factor for breast cancer. It can increase the proliferation of breast cancer cells and promote the metastasis of breast tumours in mouse models. Myc is a critical oncoprotein overexpressed in breast cancer. However, whether 27-HC affects Myc expression has not been reported. In the current study, we aimed to investigate the effects of 27-HC on Myc and the underlying mechanisms in MCF-7 breast cancer cells. Our data demonstrated that 27-HC activated Myc via increasing its protein stability. Three key negative modulators of Myc protein stability, PP2A, SCP1 and FBW7,more » were suppressed by 27-HC at the transcriptional level. We performed a data-mining analysis of the chromatin immunoprecipitation with next-generation DNA sequencing (ChIP-Seq) data in the ChIPBase, and discovered that a number of putative transcription factors (TFs), including Myc itself, were involved in the transcriptional regulation of PP2A, SCP1 and FBW7. Our results provide a novel mechanistic insight into the activation of Myc by 27-HC via transcriptional repression of PP2A, SCP1 and FBW7 to increase Myc protein stability in breast cancer cells. - Highlights: • 27-Hydroxycholesterol (27-HC) activates Myc via increasing its protein stability. • 27-HC inhibits PP2A and SCP1 transcription to block pS62-Myc dephosphorylation. • 27-HC suppresses FBW7 transcription to prevent pT58-Myc degradation.« less

Transcription of a vaccinia virus late promoter template: requirement for the product of the A2L intermediate-stage gene.

PubMed Central

Passarelli, A L; Kovacs, G R; Moss, B

1996-01-01

Evidence is presented that a 26-kDa protein encoded by the vaccinia virus A2L open reading frame, originally shown to be one of three intermediate-stage genes that together can transactivate late-stage gene expression in transfection assays (J. G. Keck, C. J. Baldick, and B. Moss, Cell 61:801-809, 1990), is required for in vitro transcription of a template with a late promoter. The critical step in this analysis was the preparation of an extract containing all the required factors except for the A2L protein. This extract was prepared from cells infected with a recombinant vaccinia virus expressing the bacteriophage T7 RNA polymerase in the presence of the DNA synthesis inhibitor cytosine arabinoside and transfected with plasmids containing the two other known transactivator genes, A1L and G8R, under T7 promoter control. Reaction mixtures made with extracts of these cells had background levels of late transcription activity, unless they were supplemented with extracts of cells transfected with the A2L gene. Active transcription mixtures were also made by mixing extracts from three sets of cells, each transfected with a gene (A1L, A2L, or G8R) encoding a separate factor, indicating the absence of any requirement for their coexpression. To minimize the possibility that the A2L protein functions indirectly by activating another viral or cellular protein, this gene was expressed in insect cells by using a baculovirus vector. The partially purified recombinant protein complemented the activity of A2L-deficient cell extracts. Recombinant A1L, A2L, and G8R proteins, all produced in insect cells, together complemented extracts from mammalian cells containing only viral early proteins, concordant with previous in vivo transfection data. PMID:8676468

Bidirectional reporter assay using HAL promoter and TOPFLASH improves specificity in high-throughput screening of Wnt inhibitors.

PubMed

Yamaguchi, Kiyoshi; Zhu, Chi; Ohsugi, Tomoyuki; Yamaguchi, Yuko; Ikenoue, Tsuneo; Furukawa, Yoichi

2017-12-01

Constitutive activation of Wnt signaling plays an important role in colorectal and liver tumorigenesis. Cell-based assays using synthetic TCF/LEF (T-cell factor/lymphoid enhancer factor) reporters, as readouts of β-catenin/TCF-dependent transcriptional activity, have contributed greatly to the discovery of small molecules that modulate Wnt signaling. In the present study, we report a novel screening method, called a bidirectional dual reporter assay. Integrated transcriptome analysis identified a histidine ammonia-lyase gene (HAL) that was negatively regulated by β-catenin/TCF-dependent transcriptional activity. We leveraged a promoter region of the HAL gene as another transcriptional readout of Wnt signaling. Cells stably expressing both an optimized HAL reporter and the TCF/LEF reporter enabled bidirectional reporter activities in response to Wnt signaling. Increased HAL reporter activity and decreased TCF/LEF reporter activity were observed simultaneously in the cells when β-catenin/TCF7L2 was inhibited. Notably, this method could decrease the number of false positives observed when screening an inhibitor library compared with the conventional TCF/LEF assay. We found that Brefeldin A, a disruptor of the Golgi apparatus, inhibited the Wnt/β-catenin signaling pathway. The utility of our system could be expanded to examine other disease-associated pathways beyond the Wnt/β-catenin signaling pathway. © 2017 Wiley Periodicals, Inc.

Genetic susceptibility to type 2 diabetes and obesity: follow-up of findings from genome-wide association studies.

PubMed

Basile, Kevin J; Johnson, Matthew E; Xia, Qianghua; Grant, Struan F A

2014-01-01

Elucidating the underlying genetic variations influencing various complex diseases is one of the major challenges currently facing clinical genetic research. Although these variations are often difficult to uncover, approaches such as genome-wide association studies (GWASs) have been successful at finding statistically significant associations between specific genomic loci and disease susceptibility. GWAS has been especially successful in elucidating genetic variants that influence type 2 diabetes (T2D) and obesity/body mass index (BMI). Specifically, several GWASs have confirmed that a variant in transcription factor 7-like 2 (TCF7L2) confers risk for T2D, while a variant in fat mass and obesity-associated protein (FTO) confers risk for obesity/BMI; indeed both of these signals are considered the most statistically associated loci discovered for these respective traits to date. The discovery of these two key loci in this context has been invaluable for providing novel insight into mechanisms of heritability and disease pathogenesis. As follow-up studies of TCF7L2 and FTO have typically lead the way in how to follow up a GWAS discovery, we outline what has been learned from such investigations and how they have implications for the myriad of other loci that have been subsequently reported in this disease context.

MENA is a transcriptional target of the Wnt/beta-catenin pathway.

PubMed

Najafov, Ayaz; Seker, Tuncay; Even, Ipek; Hoxhaj, Gerta; Selvi, Osman; Ozel, Duygu Esen; Koman, Ahmet; Birgül-İyison, Necla

2012-01-01

Wnt/β-catenin signalling pathway plays important roles in embryonic development and carcinogenesis. Overactivation of the pathway is one of the most common driving forces in major cancers such as colorectal and breast cancers. The downstream effectors of the pathway and its regulation of carcinogenesis and metastasis are still not very well understood. In this study, which was based on two genome-wide transcriptomics screens, we identify MENA (ENAH, Mammalian enabled homologue) as a novel transcriptional target of the Wnt/β-catenin signalling pathway. We show that the expression of MENA is upregulated upon overexpression of degradation-resistant β-catenin. Promoters of all mammalian MENA homologues contain putative binding sites for Tcf4 transcription factor--the primary effector of the Wnt/β-catenin pathway and we demonstrate functionality of these Tcf4-binding sites using luciferase reporter assays and overexpression of β-catenin, Tcf4 and dominant-negative Tcf4. In addition, lithium chloride-mediated inhibition of GSK3β also resulted in increase in MENA mRNA levels. Chromatin immunoprecipitation showed direct interaction between β-catenin and MENA promoter in Huh7 and HEK293 cells and also in mouse brain and liver tissues. Moreover, overexpression of Wnt1 and Wnt3a ligands increased MENA mRNA levels. Additionally, knock-down of MENA ortholog in D. melanogaster eyeful and sensitized eye cancer fly models resulted in increased tumor and metastasis formations. In summary, our study identifies MENA as novel nexus for the Wnt/β-catenin and the Notch signalling cascades.

Oligonucleotides targeting TCF4 triplet repeat expansion inhibit RNA foci and mis-splicing in Fuchs' dystrophy.

PubMed

Hu, Jiaxin; Rong, Ziye; Gong, Xin; Zhou, Zhengyang; Sharma, Vivek K; Xing, Chao; Watts, Jonathan K; Corey, David R; Mootha, V Vinod

2018-03-15

Fuchs' endothelial corneal dystrophy (FECD) is the most common repeat expansion disorder. FECD impacts 4% of U.S. population and is the leading indication for corneal transplantation. Most cases are caused by an expanded intronic CUG tract in the TCF4 gene that forms nuclear foci, sequesters splicing factors and impairs splicing. We investigated the sense and antisense RNA landscape at the FECD gene and find that the sense-expanded repeat transcript is the predominant species in patient corneas. In patient tissue, sense foci number were negatively correlated with age and showed no correlation with sex. Each endothelial cell has ∼2 sense foci and each foci is single RNA molecule. We designed antisense oligonucleotides (ASOs) to target the mutant-repetitive RNA and demonstrated potent inhibition of foci in patient-derived cells. Ex vivo treatment of FECD human corneas effectively inhibits foci and reverses pathological changes in splicing. FECD has the potential to be a model for treating many trinucleotide repeat diseases and targeting the TCF4 expansion with ASOs represents a promising therapeutic strategy to prevent and treat FECD.

Effect of EDTA and Fe-EDTA complex concentration on TCF Kraft mill effluent degradability. Batch and continuous treatments.

PubMed

Diez, M C; Pouleurs, D; Navia, R; Vidal, G

2005-09-01

The effect of ethylenediaminetetracetic acid (EDTA) and Fe-EDTA complex on synthetic totally chlorine-free (TCF) effluent degradability in batch and continuously operating reactors was evaluated. Under batch treatment, the addition of EDTA and Fe-EDTA complex was studied in the range of 80 to 320 mg l(-1). Under continuously operated reactors, the Fe-EDTA complex concentration varied from 20 to 80 mg l(-1), and the hydraulic retention time (HRT) varied from 48 to 24 h. Sludge oxygen uptake rate (OUR) and chemical oxygen demand (COD) removal decreased when EDTA concentration increased in the influent under batch treatment; however, this inhibitory effect was reduced by the addition of Fe-EDTA complex. Without the addition of EDTA, COD removal decreased from 71% to 8%. The most efficient EDTA removal treatment (almost 10%) was the treatment of 80 mg l(-1) Fe-EDTA. Under continuously operated reactors, COD removal was greater than 57% in the synthetic TCF effluent with a Fe-EDTA concentration that varied from 20 to 80 mg l(-1); however, EDTA removal was lower than 25% in all cases. Synthetic TCF effluent with a Fe -EDTA concentration higher than 80 mg l(-1) could not be treated by the activated sludge treatment due to EDTA's inhibitory effect on the sludge.

Novel noncoding RNA from human Y distal heterochromatic block (Yq12) generates testis-specific chimeric CDC2L2

PubMed Central

Jehan, Zeenath; Vallinayagam, Sambandam; Tiwari, Shrish; Pradhan, Suman; Singh, Lalji; Suresh, Amritha; Reddy, Hemakumar M.; Ahuja, Y.R.; Jesudasan, Rachel A.

2007-01-01

The human Y chromosome, because it is enriched in repetitive DNA, has been very intractable to genetic and molecular analyses. There is no previous evidence for developmental stage- and testis-specific transcription from the male-specific region of the Y (MSY). Here, we present evidence for the first time for a developmental stage- and testis-specific transcription from MSY distal heterochromatic block. We isolated two novel RNAs, which localize to Yq12 in multiple copies, show testis-specific expression, and lack active X-homologs. Experimental evidence shows that one of the above Yq12 noncoding RNAs (ncRNAs) trans-splices with CDC2L2 mRNA from chromosome 1p36.3 locus to generate a testis-specific chimeric β sv13 isoform. This 67-nt 5′UTR provided by the Yq12 transcript contains within it a Y box protein-binding CCAAT motif, indicating translational regulation of the β sv13 isoform in testis. This is also the first report of trans-splicing between a Y chromosomal and an autosomal transcript. PMID:17095710

Capsaicin represses transcriptional activity of β-catenin in human colorectal cancer cells

PubMed Central

Lee, Seong-Ho; Richardson, Raphael L.; Dashwood, Roderick H.; Baek, Seung Joon

2011-01-01

Capsaicin is a pungent ingredient in chili red peppers and has been linked to suppression of growth in various cancer cells. However, the underlying mechanism(s) by which capsaicin induces growth arrest and apoptosis of cancer cells is not completely understood. In the present study, we investigated whether capsaicin alters β-catenin-dependent signaling in human colorectal cancer cells in vitro. Exposure of SW480, LoVo, and HCT-116 cells to capsaicin suppressed cell proliferation. Transient transfection with a β-catenin/T-cell factor (TCF)-responsive reporter indicated that capsaicin suppressed the transcriptional activity of β-catenin/TCF. Capsaicin treatment resulted in a decrease of intracellular β-catenin levels and a reduction of transcripts from the β-catenin gene (CTNNB1). These results were confirmed by a reduced luciferase reporter activity driven by promoter-reporter construct containing the promoter region of the Catnb gene. In addition, capsaicin destabilized β-catenin through enhancement of proteosomal-dependent degradation. Western blot and immunoprecipitation studies indicated that capsaicin treatment suppressed TCF-4 expression and disrupted the interaction of TCF-4 and β-catenin. This study identifies a role for the β-catenin/TCF-dependent pathway that potentially contributes to the anti-cancer activity of capsaicin in human colorectal cancer cells. PMID:21764279

Embryonic stem cell self-renewal pathways converge on the transcription factor Tfcp2l1

PubMed Central

Ye, Shoudong; Li, Ping; Tong, Chang; Ying, Qi-Long

2013-01-01

Mouse embryonic stem cell (mESC) self-renewal can be maintained by activation of the leukaemia inhibitory factor (LIF)/signal transducer and activator of transcription 3 (Stat3) signalling pathway or dual inhibition (2i) of glycogen synthase kinase 3 (Gsk3) and mitogen-activated protein kinase kinase (MEK). Several downstream targets of the pathways involved have been identified that when individually overexpressed can partially support self-renewal. However, none of these targets is shared among the involved pathways. Here, we show that the CP2 family transcription factor Tfcp2l1 is a common target in LIF/Stat3- and 2i-mediated self-renewal, and forced expression of Tfcp2l1 can recapitulate the self-renewal-promoting effect of LIF or either of the 2i components. In addition, Tfcp2l1 can reprogram post-implantation epiblast stem cells to naïve pluripotent ESCs. Tfcp2l1 upregulates Nanog expression and promotes self-renewal in a Nanog-dependent manner. We conclude that Tfcp2l1 is at the intersection of LIF- and 2i-mediated self-renewal pathways and plays a critical role in maintaining ESC identity. Our study provides an expanded understanding of the current model of ground-state pluripotency. PMID:23942238

The specificity and flexibility of l1 reverse transcription priming at imperfect T-tracts.

PubMed

Monot, Clément; Kuciak, Monika; Viollet, Sébastien; Mir, Ashfaq Ali; Gabus, Caroline; Darlix, Jean-Luc; Cristofari, Gaël

2013-05-01

L1 retrotransposons have a prominent role in reshaping mammalian genomes. To replicate, the L1 ribonucleoprotein particle (RNP) first uses its endonuclease (EN) to nick the genomic DNA. The newly generated DNA end is subsequently used as a primer to initiate reverse transcription within the L1 RNA poly(A) tail, a process known as target-primed reverse transcription (TPRT). Prior studies demonstrated that most L1 insertions occur into sequences related to the L1 EN consensus sequence (degenerate 5'-TTTT/A-3' sites) and frequently preceded by imperfect T-tracts. However, it is currently unclear whether--and to which degree--the liberated 3'-hydroxyl extremity on the genomic DNA needs to be accessible and complementary to the poly(A) tail of the L1 RNA for efficient priming of reverse transcription. Here, we employed a direct assay for the initiation of L1 reverse transcription to define the molecular rules that guide this process. First, efficient priming is detected with as few as 4 matching nucleotides at the primer 3' end. Second, L1 RNP can tolerate terminal mismatches if they are compensated within the 10 last bases of the primer by an increased number of matching nucleotides. All terminal mismatches are not equally detrimental to DNA extension, a C being extended at higher levels than an A or a G. Third, efficient priming in the context of duplex DNA requires a 3' overhang. This suggests the possible existence of additional DNA processing steps, which generate a single-stranded 3' end to allow L1 reverse transcription. Based on these data we propose that the specificity of L1 reverse transcription initiation contributes, together with the specificity of the initial EN cleavage, to the distribution of new L1 insertions within the human genome.

The Specificity and Flexibility of L1 Reverse Transcription Priming at Imperfect T-Tracts

PubMed Central

Viollet, Sébastien; Mir, Ashfaq Ali; Gabus, Caroline; Darlix, Jean-Luc; Cristofari, Gaël

2013-01-01

L1 retrotransposons have a prominent role in reshaping mammalian genomes. To replicate, the L1 ribonucleoprotein particle (RNP) first uses its endonuclease (EN) to nick the genomic DNA. The newly generated DNA end is subsequently used as a primer to initiate reverse transcription within the L1 RNA poly(A) tail, a process known as target-primed reverse transcription (TPRT). Prior studies demonstrated that most L1 insertions occur into sequences related to the L1 EN consensus sequence (degenerate 5′-TTTT/A-3′ sites) and frequently preceded by imperfect T-tracts. However, it is currently unclear whether—and to which degree—the liberated 3′-hydroxyl extremity on the genomic DNA needs to be accessible and complementary to the poly(A) tail of the L1 RNA for efficient priming of reverse transcription. Here, we employed a direct assay for the initiation of L1 reverse transcription to define the molecular rules that guide this process. First, efficient priming is detected with as few as 4 matching nucleotides at the primer 3′ end. Second, L1 RNP can tolerate terminal mismatches if they are compensated within the 10 last bases of the primer by an increased number of matching nucleotides. All terminal mismatches are not equally detrimental to DNA extension, a C being extended at higher levels than an A or a G. Third, efficient priming in the context of duplex DNA requires a 3′ overhang. This suggests the possible existence of additional DNA processing steps, which generate a single-stranded 3′ end to allow L1 reverse transcription. Based on these data we propose that the specificity of L1 reverse transcription initiation contributes, together with the specificity of the initial EN cleavage, to the distribution of new L1 insertions within the human genome. PMID:23675310

TCF4-Targeting miR-124 is Differentially Expressed amongst Dendritic Cell Subsets

PubMed Central

Han, Sun Murray; Na, Hye Young; Ham, Onju; Choi, Wanho; Sohn, Moah; Ryu, Seul Hye; In, Hyunju; Hwang, Ki-Chul

2016-01-01

Dendritic cells (DCs) are professional antigen-presenting cells that sample their environment and present antigens to naïve T lymphocytes for the subsequent antigen-specific immune responses. DCs exist in a range of distinct subpopulations including plasmacytoid DCs (pDCs) and classical DCs (cDCs), with the latter consisting of the cDC1 and cDC2 lineages. Although the roles of DC-specific transcription factors across the DC subsets have become understood, the posttranscriptional mechanisms that regulate DC development are yet to be elucidated. MicroRNAs (miRNAs) are pivotal posttranscriptional regulators of gene expression in a myriad of biological processes, but their contribution to the immune system is just beginning to surface. In this study, our in-house probe collection was screened to identify miRNAs possibly involved in DC development and function by targeting the transcripts of relevant mouse transcription factors. Examination of DC subsets from the culture of mouse bone marrow with Flt3 ligand identified high expression of miR-124 which was able to target the transcript of TCF4, a transcription factor critical for the development and homeostasis of pDCs. Further expression profiling of mouse DC subsets isolated from in vitro culture as well as via ex vivo purification demonstrated that miR-124 was outstandingly expressed in CD24+ cDC1 cells compared to in pDCs and CD172α+ cDC2 cells. These results imply that miR-124 is likely involved in the processes of DC subset development by posttranscriptional regulation of a transcription factor(s). PMID:26937233

TCF21 is related to testis growth and development in broiler chickens.

PubMed

Zhang, Hui; Na, Wei; Zhang, Hong-Li; Wang, Ning; Du, Zhi-Qiang; Wang, Shou-Zhi; Wang, Zhi-Peng; Zhang, Zhiwu; Li, Hui

2017-02-24

Large amounts of fat deposition often lead to loss of reproductive efficiency in humans and animals. We used broiler chickens as a model species to conduct a two-directional selection for and against abdominal fat over 19 generations, which resulted in a lean and a fat line. Direct selection for abdominal fat content also indirectly resulted in significant differences (P < 0.05) in testis weight (TeW) and in TeW as a percentage of total body weight (TeP) between the lean and fat lines. A total of 475 individuals from the generation 11 (G 11 ) were genotyped. Genome-wide association studies revealed two regions on chicken chromosomes 3 and 10 that were associated with TeW and TeP. Forty G 16 individuals (20 from each line), were further profiled by focusing on these two chromosomal regions, to identify candidate genes with functions that may be potentially related to testis growth and development. Of the nine candidate genes identified with database mining, a significant association was confirmed for one gene, TCF21, based on mRNA expression analysis. Gene expression analysis of the TCF21 gene was conducted again across 30 G 19 individuals (15 individuals from each line) and the results confirmed the findings on the G 16 animals. This study revealed that the TCF21 gene is related to testis growth and development in male broilers. This finding will be useful to guide future studies to understand the genetic mechanisms that underlie reproductive efficiency.

Replication of type 2 diabetes candidate genes variations in three geographically unrelated Indian population groups.

PubMed

Ali, Shafat; Chopra, Rupali; Manvati, Siddharth; Singh, Yoginder Pal; Kaul, Nabodita; Behura, Anita; Mahajan, Ankit; Sehajpal, Prabodh; Gupta, Subash; Dhar, Manoj K; Chainy, Gagan B N; Bhanwer, Amarjit S; Sharma, Swarkar; Bamezai, Rameshwar N K

2013-01-01

Type 2 diabetes (T2D) is a syndrome of multiple metabolic disorders and is genetically heterogeneous. India comprises one of the largest global populations with highest number of reported type 2 diabetes cases. However, limited information about T2D associated loci is available for Indian populations. It is, therefore, pertinent to evaluate the previously associated candidates as well as identify novel genetic variations in Indian populations to understand the extent of genetic heterogeneity. We chose to do a cost effective high-throughput mass-array genotyping and studied the candidate gene variations associated with T2D in literature. In this case-control candidate genes association study, 91 SNPs from 55 candidate genes have been analyzed in three geographically independent population groups from India. We report the genetic variants in five candidate genes: TCF7L2, HHEX, ENPP1, IDE and FTO, are significantly associated (after Bonferroni correction, p<5.5E-04) with T2D susceptibility in combined population. Interestingly, SNP rs7903146 of the TCF7L2 gene passed the genome wide significance threshold (combined P value = 2.05E-08) in the studied populations. We also observed the association of rs7903146 with blood glucose (fasting and postprandial) levels, supporting the role of TCF7L2 gene in blood glucose homeostasis. Further, we noted that the moderate risk provided by the independently associated loci in combined population with Odds Ratio (OR)<1.38 increased to OR = 2.44, (95%CI = 1.67-3.59) when the risk providing genotypes of TCF7L2, HHEX, ENPP1 and FTO genes were combined, suggesting the importance of gene-gene interactions evaluation in complex disorders like T2D.

Replication of Type 2 Diabetes Candidate Genes Variations in Three Geographically Unrelated Indian Population Groups

PubMed Central

Ali, Shafat; Chopra, Rupali; Manvati, Siddharth; Mahajan, Ankit; Sehajpal, Prabodh; Gupta, Subash; Dhar, Manoj K.; Chainy, Gagan B. N.; Bhanwer, Amarjit S.; Sharma, Swarkar; Bamezai, Rameshwar N. K.

2013-01-01

Type 2 diabetes (T2D) is a syndrome of multiple metabolic disorders and is genetically heterogeneous. India comprises one of the largest global populations with highest number of reported type 2 diabetes cases. However, limited information about T2D associated loci is available for Indian populations. It is, therefore, pertinent to evaluate the previously associated candidates as well as identify novel genetic variations in Indian populations to understand the extent of genetic heterogeneity. We chose to do a cost effective high-throughput mass-array genotyping and studied the candidate gene variations associated with T2D in literature. In this case-control candidate genes association study, 91 SNPs from 55 candidate genes have been analyzed in three geographically independent population groups from India. We report the genetic variants in five candidate genes: TCF7L2, HHEX, ENPP1, IDE and FTO, are significantly associated (after Bonferroni correction, p<5.5E−04) with T2D susceptibility in combined population. Interestingly, SNP rs7903146 of the TCF7L2 gene passed the genome wide significance threshold (combined P value = 2.05E−08) in the studied populations. We also observed the association of rs7903146 with blood glucose (fasting and postprandial) levels, supporting the role of TCF7L2 gene in blood glucose homeostasis. Further, we noted that the moderate risk provided by the independently associated loci in combined population with Odds Ratio (OR)<1.38 increased to OR = 2.44, (95%CI = 1.67–3.59) when the risk providing genotypes of TCF7L2, HHEX, ENPP1 and FTO genes were combined, suggesting the importance of gene-gene interactions evaluation in complex disorders like T2D. PMID:23527042

Genomics and drug profiling of fatal TCF3-HLF-positive acute lymphoblastic leukemia identifies recurrent mutation patterns and therapeutic options

PubMed Central

Bornhauser, Beat; Gombert, Michael; Kratsch, Christina; Stütz, Adrian M.; Sultan, Marc; Tchinda, Joelle; Worth, Catherine L.; Amstislavskiy, Vyacheslav; Badarinarayan, Nandini; Baruchel, André; Bartram, Thies; Basso, Giuseppe; Canpolat, Cengiz; Cario, Gunnar; Cavé, Hélène; Dakaj, Dardane; Delorenzi, Mauro; Dobay, Maria Pamela; Eckert, Cornelia; Ellinghaus, Eva; Eugster, Sabrina; Frismantas, Viktoras; Ginzel, Sebastian; Haas, Oskar A.; Heidenreich, Olaf; Hemmrich-Stanisak, Georg; Hezaveh, Kebria; Höll, Jessica I.; Hornhardt, Sabine; Husemann, Peter; Kachroo, Priyadarshini; Kratz, Christian P.; te Kronnie, Geertruy; Marovca, Blerim; Niggli, Felix; McHardy, Alice C.; Moorman, Anthony V.; Panzer-Grümayer, Renate; Petersen, Britt S.; Raeder, Benjamin; Ralser, Meryem; Rosenstiel, Philip; Schäfer, Daniel; Schrappe, Martin; Schreiber, Stefan; Schütte, Moritz; Stade, Björn; Thiele, Ralf; von der Weid, Nicolas; Vora, Ajay; Zaliova, Marketa; Zhang, Langhui; Zichner, Thomas; Zimmermann, Martin; Lehrach, Hans; Borkhardt, Arndt; Bourquin, Jean-Pierre; Franke, Andre; Korbel, Jan O.; Stanulla, Martin; Yaspo, Marie-Laure

2015-01-01

TCF3-HLF-fusion positive acute lymphoblastic leukemia (ALL) is currently incurable. Employing an integrated approach, we uncovered distinct mutation, gene expression, and drug response profiles in TCF3-HLF-positive and treatment-responsive TCF3-PBX1-positive ALL. Recurrent intragenic deletions of PAX5 or VPREB1 were identified in constellation with TCF3-HLF. Moreover somatic mutations in the non-translocated allele of TCF3 and a reduction of PAX5 gene dosage in TCF3-HLF ALL suggest cooperation within a restricted genetic context. The enrichment for stem cell and myeloid features in the TCF3-HLF signature may reflect reprogramming by TCF3-HLF of a lymphoid-committed cell of origin towards a hybrid, drug-resistant hematopoietic state. Drug response profiling of matched patient-derived xenografts revealed a distinct profile for TCF3-HLF ALL with resistance to conventional chemotherapeutics, but sensitivity towards glucocorticoids, anthracyclines and agents in clinical development. Striking on-target sensitivity was achieved with the BCL2-specific inhibitor venetoclax (ABT-199). This integrated approach thus provides alternative treatment options for this deadly disease. PMID:26214592

Comparative analysis of the ternary complex factors Elk-1, SAP-1a and SAP-2 (ERP/NET).

PubMed Central

Price, M A; Rogers, A E; Treisman, R

1995-01-01

A transcription factor ternary complex composed of Serum Response Factor (SRF) and Ternary Complex Factor (TCF) mediates the response of the c-fos Serum Response Element (SRE) to growth factors and mitogens. Three Ets domain proteins, Elk-1, SAP-1 and ERP/NET, have been reported to have the properties of TCF. Here we compare Elk-1 and SAP-1a with the human ERP/NET homologue SAP-2. All three TCF RNAs are ubiquitously expressed at similar relative levels. All three proteins contain conserved regions that interact with SRF and the c-fos SRE with comparable efficiency, but in vitro complex formation by SAP-2 is strongly inhibited by its C-terminal sequences. Similarly, only Elk-1 and SAP-1a efficiently bind the c-fos SRE in vivo; ternary complex formation by SAP-2 is weak and is substantially unaffected by serum stimulation or v-ras co-expression. All three TCFs contain C-terminal transcriptional activation domains that are phosphorylated following growth factor stimulation. Activation requires conserved S/T-P motifs found in all the TCF family members. Each TCF activation domain can be phosphorylated in vitro by partially purified ERK2, and ERK activation in vivo is sufficient to potentiate transcriptional activation. Images PMID:7540136

Comparative analysis of the ternary complex factors Elk-1, SAP-1a and SAP-2 (ERP/NET).

PubMed

Price, M A; Rogers, A E; Treisman, R

1995-06-01

A transcription factor ternary complex composed of Serum Response Factor (SRF) and Ternary Complex Factor (TCF) mediates the response of the c-fos Serum Response Element (SRE) to growth factors and mitogens. Three Ets domain proteins, Elk-1, SAP-1 and ERP/NET, have been reported to have the properties of TCF. Here we compare Elk-1 and SAP-1a with the human ERP/NET homologue SAP-2. All three TCF RNAs are ubiquitously expressed at similar relative levels. All three proteins contain conserved regions that interact with SRF and the c-fos SRE with comparable efficiency, but in vitro complex formation by SAP-2 is strongly inhibited by its C-terminal sequences. Similarly, only Elk-1 and SAP-1a efficiently bind the c-fos SRE in vivo; ternary complex formation by SAP-2 is weak and is substantially unaffected by serum stimulation or v-ras co-expression. All three TCFs contain C-terminal transcriptional activation domains that are phosphorylated following growth factor stimulation. Activation requires conserved S/T-P motifs found in all the TCF family members. Each TCF activation domain can be phosphorylated in vitro by partially purified ERK2, and ERK activation in vivo is sufficient to potentiate transcriptional activation.

29 CFR 417.7 - Transcript.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 29 Labor 2 2013-07-01 2013-07-01 false Transcript. 417.7 Section 417.7 Labor Regulations Relating to Labor OFFICE OF LABOR-MANAGEMENT STANDARDS, DEPARTMENT OF LABOR LABOR-MANAGEMENT STANDARDS PROCEDURE FOR REMOVAL OF LOCAL LABOR ORGANIZATION OFFICERS Procedures To Determine Adequacy of Constitution...

29 CFR 417.7 - Transcript.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 29 Labor 2 2014-07-01 2014-07-01 false Transcript. 417.7 Section 417.7 Labor Regulations Relating to Labor OFFICE OF LABOR-MANAGEMENT STANDARDS, DEPARTMENT OF LABOR LABOR-MANAGEMENT STANDARDS PROCEDURE FOR REMOVAL OF LOCAL LABOR ORGANIZATION OFFICERS Procedures To Determine Adequacy of Constitution...

29 CFR 417.7 - Transcript.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 2 2010-07-01 2010-07-01 false Transcript. 417.7 Section 417.7 Labor Regulations Relating to Labor OFFICE OF LABOR-MANAGEMENT STANDARDS, DEPARTMENT OF LABOR LABOR-MANAGEMENT STANDARDS PROCEDURE FOR REMOVAL OF LOCAL LABOR ORGANIZATION OFFICERS Procedures To Determine Adequacy of Constitution...

29 CFR 417.7 - Transcript.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 2 2011-07-01 2011-07-01 false Transcript. 417.7 Section 417.7 Labor Regulations Relating to Labor OFFICE OF LABOR-MANAGEMENT STANDARDS, DEPARTMENT OF LABOR LABOR-MANAGEMENT STANDARDS PROCEDURE FOR REMOVAL OF LOCAL LABOR ORGANIZATION OFFICERS Procedures To Determine Adequacy of Constitution...

29 CFR 417.7 - Transcript.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 29 Labor 2 2012-07-01 2012-07-01 false Transcript. 417.7 Section 417.7 Labor Regulations Relating to Labor OFFICE OF LABOR-MANAGEMENT STANDARDS, DEPARTMENT OF LABOR LABOR-MANAGEMENT STANDARDS PROCEDURE FOR REMOVAL OF LOCAL LABOR ORGANIZATION OFFICERS Procedures To Determine Adequacy of Constitution...

Impairment of different protein domains causes variable clinical presentation within Pitt-Hopkins syndrome and suggests intragenic molecular syndromology of TCF4.

PubMed

Bedeschi, Maria Francesca; Marangi, Giuseppe; Calvello, Maria Rosaria; Ricciardi, Stefania; Leone, Francesca Pia Chiara; Baccarin, Marco; Guerneri, Silvana; Orteschi, Daniela; Murdolo, Marina; Lattante, Serena; Frangella, Silvia; Keena, Beth; Harr, Margaret H; Zackai, Elaine; Zollino, Marcella

2017-11-01

Pitt-Hopkins syndrome is a neurodevelopmental disorder characterized by severe intellectual disability and a distinctive facial gestalt. It is caused by haploinsufficiency of the TCF4 gene. The TCF4 protein has different functional domains, with the NLS (nuclear localization signal) domain coded by exons 7-8 and the bHLH (basic Helix-Loop-Helix) domain coded by exon 18. Several alternatively spliced TCF4 variants have been described, allowing for translation of variable protein isoforms. Typical PTHS patients have impairment of at least the bHLH domain. To which extent impairment of the remaining domains contributes to the final phenotype is not clear. There is recent evidence that certain loss-of-function variants disrupting TCF4 are associated with mild ID, but not with typical PTHS. We describe a frameshift-causing partial gene deletion encompassing exons 4-6 of TCF4 in an adult patient with mild ID and nonspecific facial dysmorphisms but without the typical features of PTHS, and a c.520C > T nonsense variant within exon 8 in a child presenting with a severe phenotype largely mimicking PTHS, but lacking the typical facial dysmorphism. Investigation on mRNA, along with literature review, led us to suggest a preliminary phenotypic map of loss-of-function variants affecting TCF4. An intragenic phenotypic map of loss-of-function variants in TCF4 is suggested here for the first time: variants within exons 1-4 and exons 4-6 give rise to a recurrent phenotype with mild ID not in the spectrum of Pitt-Hopkins syndrome (biallelic preservation of both the NLS and bHLH domains); variants within exons 7-8 cause a severe phenotype resembling PTHS but in absence of the typical facial dysmorphism (impairment limited to the NLS domain); variants within exons 9-19 cause typical Pitt-Hopkins syndrome (impairment of at least the bHLH domain). Understanding the TCF4 molecular syndromology can allow for proper nosology in the current era of whole genomic investigations. Copyright �

The transcriptional terminator sequences downstream of the covR gene terminate covR/S operon transcription to generate covR monocistronic transcripts in Streptococcus pyogenes.

PubMed

Chiang-Ni, Chuan; Tsou, Chih-Cheng; Lin, Yee-Shin; Chuang, Woei-Jer; Lin, Ming-T; Liu, Ching-Chuan; Wu, Jiunn-Jong

2008-12-31

CovR/S is an important two component regulatory system, which regulates about 15% of the gene expression in Streptococcus pyogenes. The covR/S locus was identified as an operon generating an RNA transcript around 2.5-kb in size. In this study, we found the covR/S operon produced three RNA transcripts (around 2.5-, 1.0-, and 0.8-kb in size). Using RNA transcriptional terminator sequence prediction and transcriptional terminator analysis, we identified two atypical rho-independent terminator sequences downstream of the covR gene and showed these terminator sequences terminate RNA transcription efficiently. These results indicate that covR/S operon generates covR/S transcript and monocistronic covR transcripts.

The Wheat NAC Transcription Factor TaNAC2L Is Regulated at the Transcriptional and Post-Translational Levels and Promotes Heat Stress Tolerance in Transgenic Arabidopsis.

PubMed

Guo, Weiwei; Zhang, Jinxia; Zhang, Ning; Xin, Mingming; Peng, Huiru; Hu, Zhaorong; Ni, Zhongfu; Du, Jinkun

2015-01-01

Heat stress poses a serious threat to global crop production. In efforts that aim to mitigate the adverse effects of heat stress on crops, a variety of genetic tools are being used to develop plants with improved thermotolerance. The characterization of important regulators of heat stress tolerance provides essential information for this aim. In this study, we examine the wheat (Triticum aestivum) NAC transcription factor gene TaNAC2L. High temperature induced TaNAC2L expression in wheat and overexpression of TaNAC2L in Arabidopsis thaliana enhanced acquired heat tolerance without causing obvious alterations in phenotype compared with wild type under normal conditions. TaNAC2L overexpression also activated the expression of heat-related genes in the transgenic Arabidopsis plants, suggesting that TaNAC2L may improve heat tolerance by regulating the expression of stress-responsive genes. Notably, TaNAC2L is also regulated at the post-translational level and might be degraded via a proteasome-mediated pathway. Thus, this wheat transcription factor may have potential uses in enhancing thermotolerance in crops.

Candidate gene association study conditioning on individual ancestry in patients with type 2 diabetes and metabolic syndrome from Mexico City.

PubMed

Cruz, M; Valladares-Salgado, A; Garcia-Mena, J; Ross, K; Edwards, M; Angeles-Martinez, J; Ortega-Camarillo, C; de la Peña, J Escobedo; Burguete-Garcia, A I; Wacher-Rodarte, N; Ambriz, R; Rivera, R; D'artote, A L; Peralta, J; Parra, Esteban J; Kumate, J

2010-05-01

Type 2 diabetes (T2D) is influenced by diverse environmental and genetic risk factors. Metabolic syndrome (MS) increases the risk of cardiovascular disease and diabetes. We analysed 14 cases of polymorphisms located in 10 candidate loci, in a sample of patients with T2D and controls from Mexico City. We analysed the association of 14 polymorphisms located within 10 genes (TCF7L2, ENPP1, ADRB3, KCNJ11, LEPR, PPARgamma, FTO, CDKAL1, SIRT1 and HHEX) with T2D and MS. The analysis included 519 subjects with T2D defined according to the ADA criteria, 389 with MS defined according to the AHA/NHLBI criteria and 547 controls. Association was tested with the program ADMIXMAP including individual ancestry, age, sex, education and in some cases body mass index (BMI), in a logistic regression model. The two markers located within the TCF7L2 gene showed strong associations with T2D (rs7903146, T allele, odd ratio (OR) = 1.76, p = 0.001 and rs12255372, T allele, OR = 1.78, p = 0.002), but did not show significant association with MS. The non-synonymous rs4994 polymorphism of the ADRB3 gene was associated with T2D (Trp allele, OR = 0.62, p = 0.001) and MS (Trp allele, OR = 0.74, p = 0.018). Nominally significant associations were also observed between T2D and the SIRT1 rs3758391 SNP and MS and the HHEX rs5015480 polymorphism. Variants located within the gene TCF7L2 are strongly associated with T2D but not with MS, providing support to previous evidence indicating that polymorphisms at the TCF7L2 gene increase T2D risk. In contrast, the non-synonymous ADRB3 rs4994 polymorphism is associated with T2D and MS.

The transcription factor LEF-1 induces an epithelial–mesenchymal transition in MDCK cells independent of β-catenin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kobayashi, Wakako; Ozawa, Masayuki, E-mail: mozawa@m.kufm.kagoshima-u.ac.jp

2013-12-06

Highlights: •The transcription factor LEF-1 induces an EMT in MDCK cells. •A mutant LEF-1 that cannot interact with β-catenin retained the ability. •The nuclear function of β-catenin was not necessary for the LEF-1-induced EMT. •The mRNA levels of Slug, ZEB1, and ZEB2 increased significantly in these cells. -- Abstract: The epithelial–mesenchymal transition (EMT), a key process in the tumor metastatic cascade, is characterized by the loss of cell–cell junctions and cell polarity, as well as the acquisition of migratory and invasive properties. LEF-1 is a member of the lymphoid enhancer-binding factor/T-cell factor (LEF/TCF) family of DNA-binding transcription factors, which interactmore » with nuclear β-catenin and act as central transcriptional mediators of Wnt signaling. To investigate the role of LEF-1 in EMT, we generated stable LEF-1 transfectants using MDCK cells. The transfectants had a spindle-shaped mesenchymal morphology, and enhanced migration and invasiveness relative to control cells. These EMT changes were accompanied by the downregulation of an epithelial marker protein, E-cadherin, and the upregulation of mesenchymal marker proteins, vimentin and N-cadherin. Consistent with these observations, the mRNA levels of Slug, ZEB1, and ZEB2—EMT-related transcription factors—increased significantly. Although the N-terminally deleted mutant LEF-1 cannot interact with β-catenin, it retained the ability to induce EMT. Consistent with these observations, neither the expression of a dominant negative β-catenin/engrailed chimera, nor the expression of a cytoplasmic domain of E-cadherin that sequesters β-catenin from binding to LEF/TCF, reversed LEF-1-induced EMT. Together, these data indicated that the nuclear function of β-catenin was not necessary for the induction of Slug, ZEB1, and ZEB2 expression leading to EMT.« less

Epistatic interactions between mutations of TACI (TNFRSF13B) and TCF3 result in a severe primary immunodeficiency disorder and systemic lupus erythematosus

PubMed Central

Ameratunga, Rohan; Koopmans, Wikke; Woon, See-Tarn; Leung, Euphemia; Lehnert, Klaus; Slade, Charlotte A; Tempany, Jessica C; Enders, Anselm; Steele, Richard; Browett, Peter; Hodgkin, Philip D; Bryant, Vanessa L

2017-01-01

Common variable immunodeficiency disorders (CVID) are a group of primary immunodeficiencies where monogenetic causes account for only a fraction of cases. On this evidence, CVID is potentially polygenic and epistatic although there are, as yet, no examples to support this hypothesis. We have identified a non-consanguineous family, who carry the C104R (c.310T>C) mutation of the Transmembrane Activator Calcium-modulator and cyclophilin ligand Interactor (TACI, TNFRSF13B) gene. Variants in TNFRSF13B/TACI are identified in up to 10% of CVID patients, and are associated with, but not solely causative of CVID. The proband is heterozygous for the TNFRSF13B/TACI C104R mutation and meets the Ameratunga et al. diagnostic criteria for CVID and the American College of Rheumatology criteria for systemic lupus erythematosus (SLE). Her son has type 1 diabetes, arthritis, reduced IgG levels and IgA deficiency, but has not inherited the TNFRSF13B/TACI mutation. Her brother, homozygous for the TNFRSF13B/TACI mutation, is in good health despite profound hypogammaglobulinemia and mild cytopenias. We hypothesised that a second unidentified mutation contributed to the symptomatic phenotype of the proband and her son. Whole-exome sequencing of the family revealed a de novo nonsense mutation (T168fsX191) in the Transcription Factor 3 (TCF3) gene encoding the E2A transcription factors, present only in the proband and her son. We demonstrate mutations of TNFRSF13B/TACI impair immunoglobulin isotype switching and antibody production predominantly via T-cell-independent signalling, while mutations of TCF3 impair both T-cell-dependent and -independent pathways of B-cell activation and differentiation. We conclude that epistatic interactions between mutations of the TNFRSF13B/TACI and TCF3 signalling networks lead to the severe CVID-like disorder and SLE in the proband. PMID:29114388

An improved TCF sequence for biobleaching kenaf pulp: influence of the hexenuronic acid content and the use of xylanase.

PubMed

Andreu, Glòria; Vidal, Teresa

2014-01-01

Enzymatic delignification with laccase from Trametes villosa used in combination with chemical mediators (acetosyringone, acetovanillone and 1-hydroxybenzotriazole) to improve the totally chlorine-free (TCF) bleaching of kenaf pulp was studied. The best final pulp properties were obtained by using an LHBTQPo sequence developed by incorporating a laccase-mediator stage into an industrial bleaching sequence involving chelation and peroxide stages. The new sequence resulted in increased kenaf pulp delignification (90.4%) and brightness (77.2%ISO) relative to a conventional TCF chemical sequence (74.5% delignification and 74.5% brightness). Also, the sequence provided bleached kenaf fibers with high cellulose content (pulp viscosity of 890 g·mL(-1) vs 660 g·mL(-1)). Scanning electron micrographs revealed that xylanase altered fiber surfaces and facilitated reagent access as a result. However, the LHBTX (xylanase) stage removed 21% of hexenuronic acids in kenaf pulp. These recalcitrant compounds spent additional bleaching reagents and affected pulp properties after peroxide stage. Copyright © 2013 Elsevier Ltd. All rights reserved.

FOXO1 opposition of CD8+ T cell effector programming confers early memory properties and phenotypic diversity.

PubMed

Delpoux, Arnaud; Lai, Chen-Yen; Hedrick, Stephen M; Doedens, Andrew L

2017-10-17

The factors and steps controlling postinfection CD8 + T cell terminal effector versus memory differentiation are incompletely understood. Whereas we found that naive TCF7 (alias "Tcf-1") expression is FOXO1 independent, early postinfection we report bimodal, FOXO1-dependent expression of the memory-essential transcription factor TCF7 in pathogen-specific CD8 + T cells. We determined the early postinfection TCF7 high population is marked by low TIM3 expression and bears memory signature hallmarks before the appearance of established memory precursor marker CD127 (IL-7R). These cells exhibit diminished TBET, GZMB, mTOR signaling, and cell cycle progression. Day 5 postinfection, TCF7 high cells express higher memory-associated BCL2 and EOMES, as well as increased accumulation potential and capacity to differentiate into memory phenotype cells. TCF7 retroviral transduction opposes GZMB expression and the formation of KLRG1 pos phenotype cells, demonstrating an active role for TCF7 in extinguishing the effector program and forestalling terminal differentiation. Past the peak of the cellular immune response, we report a gradient of FOXO1 and TCF7 expression, which functions to oppose TBET and orchestrate a continuum of effector-to-memory phenotypes.

Biodegradation of the Organophosphate Trichlorfon and Its Major Degradation Products by a Novel Aspergillus sydowii PA F-2.

PubMed

Tian, Jiang; Dong, Qiaofeng; Yu, Chenlei; Zhao, Ruixue; Wang, Jing; Chen, Lanzhou

2016-06-01

Trichlorfon (TCF) is an important organophosphate pesticide in agriculture. However, limited information is known about the biodegradation behaviors and kinetics of this pesticide. In this study, a newly isolated fungus (PA F-2) from pesticide-polluted soils was identified as Aspergillus sydowii on the basis of the sequencing of internal transcribed spacer rDNA. This fungus degraded TCF as sole carbon, sole phosphorus, and sole carbon-phosphorus sources in a mineral salt medium (MSM). Optimal TCF degradation conditions were determined through response surface methodology, and results also revealed that 75.31% of 100 mg/L TCF was metabolized within 7 days. The degradation of TCF was accelerated, and the mycelial dry weight of PA F-2 was remarkably increased in MSM supplemented with exogenous sucrose and yeast extract. Five TCF metabolic products were identified through gas chromatography-mass spectrometry. TCF could be initially hydrolyzed to dichlorvos and then be degraded through the cleavage of the P-C bond to produce dimethyl hydrogen phosphate and chloral hydrate. These two compounds were subsequently deoxidized to produce dimethyl phosphite and trichloroethanal. These results demonstrate the biodegradation pathways of TCF and promote the potential use of PA F-2 to bioremediate TCF-contaminated environments.

Molecular mechanism of transcription inhibition by phage T7 gp2 protein.

PubMed

Mekler, Vladimir; Minakhin, Leonid; Sheppard, Carol; Wigneshweraraj, Sivaramesh; Severinov, Konstantin

2011-11-11

Escherichia coli T7 bacteriophage gp2 protein is a potent inhibitor of host RNA polymerase (RNAP). gp2 inhibits formation of open promoter complex by binding to the β' jaw, an RNAP domain that interacts with downstream promoter DNA. Here, we used an engineered promoter with an optimized sequence to obtain and characterize a specific promoter complex containing RNAP and gp2. In this complex, localized melting of promoter DNA is initiated but does not propagate to include the point of the transcription start. As a result, the complex is transcriptionally inactive. Using a highly sensitive RNAP beacon assay, we performed quantitative real-time measurements of specific binding of the RNAP-gp2 complex to promoter DNA and various promoter fragments. In this way, the effect of gp2 on RNAP interaction with promoters was dissected. As expected, gp2 greatly decreased RNAP affinity to downstream promoter duplex. However, gp2 also inhibited RNAP binding to promoter fragments that lacked downstream promoter DNA that interacts with the β' jaw. The inhibition was caused by gp2-mediated decrease of the RNAP binding affinity to template and non-template strand segments of the transcription bubble downstream of the -10 promoter element. The inhibition of RNAP interactions with single-stranded segments of the transcription bubble by gp2 is a novel effect, which may occur via allosteric mechanism that is set in motion by the gp2 binding to the β' jaw. Copyright © 2011 Elsevier Ltd. All rights reserved.

The Transcription Factors TBX2 and TBX3 Interact with Human Papillomavirus 16 (HPV16) L2 and Repress the Long Control Region of HPVs

PubMed Central

Schneider, Marc A.; Scheffer, Konstanze D.; Bund, Timo; Boukhallouk, Fatima; Lambert, Carsten; Cotarelo, Cristina; Pflugfelder, Gert O.

2013-01-01

The minor capsid protein L2 of human papillomaviruses (HPVs) has multiple functions during the viral life cycle. Although L2 is required for effective invasion and morphogenesis, only a few cellular interaction partners are known so far. Using yeast two-hybrid screening, we identified the transcription factor TBX2 as a novel interaction partner of HPV type 16 (HPV16) L2. Coimmunoprecipitations and immunofluorescence analyses confirmed the L2-TBX2 interaction and revealed that L2 also interacts with TBX3, another member of the T-box family. Transcription of the early genes during HPV infection is under the control of an upstream enhancer and early promoter region, the long control region (LCR). In promoter-reporter gene assays, we observed that TBX2 and TBX3 repress transcription from the LCR and that this effect is enhanced by L2. Repression of the HPV LCR by TBX2/3 seems to be a conserved mechanism, as it was also observed with the LCRs of different HPV types. Finally, interaction of TBX2 with the LCR was detected by chromatin immunoprecipitation, and we found a strong colocalization of L2 and TBX2 in HPV16-positive cervical intraepithelial neoplasia (CIN) I-II tissue sections. These results suggest that TBX2/3 might play a role in the regulation of HPV gene expression during the viral life cycle. PMID:23388722

Implication of genetic variants near SLC30A8, HHEX, CDKAL1, CDKN2A/B, IGF2BP2, FTO, TCF2, KCNQ1, and WFS1 in Type 2 Diabetes in a Chinese population

PubMed Central

2010-01-01

Background Recently, several genome-wide and candidate gene association studies have identified many novel genetic loci for type 2 diabetes (T2D); among these genes, CDKAL1, IGF2BP2, SLC30A8, CDKN2A/B, HHEX, FTO, TCF2, KCNQ1, and WFS1 are the most important. We aimed to determine the effects of these genetic loci associated with T2D in the Chinese Han population of China. Methods Single-nucleotide polymorphisms (SNPs) in or near CDKAL1, IGF2BP2, SLC30A8, CDKN2A/B, HHEX, FTO, TCF2, KCNQ1, and WFS1 genes were genotyped in a case-control Chinese Han sample living in Beijing, China involving 1024 patients with T2D and 1005 control subjects. Results In Chinese Han, we replicated the associations between 7 genetic loci and T2D, with risk allele-specific odds ratios (ORs) as follows: 1.27 (95% CI, 1.11-1.45; p = 0.0008) for CDKAL1-rs10946398, 1.26 (95% CI, 1.08-1.47; p = 0.003) for IGF2BP2-rs4402960, 1.19 (95% CI, 1.04-1.37; p = 0.009) for SLC30A8-rs13266634, 1.22 (95% CI, 1.06-1.41; p = 0.005) for CDKN2A/B-rs10811661, 1.20 (95% CI, 1.01-1.42; p = 0.03) for HHEX-rs5015480, 1.37 (95% CI, 1.19-1.69; p = 1.0 × 10-4) for KCNQ1-rs2237892, and 1.24 (95% CI, 1.01-1.52; p = 0.046) for FTO-rs8050136 after adjustment for age, gender, and body mass index. Not only did an association between WFS1-rs6446482 and early-onset T2D exist in the subgroup analysis, but TCF2-rs7501939 and WFS1-rs6446482 were also confirmed to confer risk for T2D in this meta-analysis. Moreover, the relationship between FTO-rs8050136 and body mass index, together with the effect of CDKAL1-rs10946398 on beta cell function, was also observed in the control individuals. Conclusions Our findings support the important contribution of these genetic loci to susceptibility for T2D in the Chinese Han population in Beijing of China. PMID:20509872

Metabolic transcription analysis of engineered Escherichia coli strains that overproduce L-phenylalanine

PubMed Central

Báez-Viveros, José Luis; Flores, Noemí; Juárez, Katy; Castillo-España, Patricia; Bolivar, Francisco; Gosset, Guillermo

2007-01-01

Background The rational design of L-phenylalanine (L-Phe) overproducing microorganisms has been successfully achieved by combining different genetic strategies such as inactivation of the phosphoenolpyruvate: phosphotransferase transport system (PTS) and overexpression of key genes (DAHP synthase, transketolase and chorismate mutase-prephenate dehydratase), reaching yields of 0.33 (g-Phe/g-Glc), which correspond to 60% of theoretical maximum. Although genetic modifications introduced into the cell for the generation of overproducing organisms are specifically targeted to a particular pathway, these can trigger unexpected transcriptional responses of several genes. In the current work, metabolic transcription analysis (MTA) of both L-Phe overproducing and non-engineered strains using Real-Time PCR was performed, allowing the detection of transcriptional responses to PTS deletion and plasmid presence of genes related to central carbon metabolism. This MTA included 86 genes encoding enzymes of glycolysis, gluconeogenesis, pentoses phosphate, tricarboxylic acid cycle, fermentative and aromatic amino acid pathways. In addition, 30 genes encoding regulatory proteins and transporters for aromatic compounds and carbohydrates were also analyzed. Results MTA revealed that a set of genes encoding carbohydrate transporters (galP, mglB), gluconeogenic (ppsA, pckA) and fermentative enzymes (ldhA) were significantly induced, while some others were down-regulated such as ppc, pflB, pta and ackA, as a consequence of PTS inactivation. One of the most relevant findings was the coordinated up-regulation of several genes that are exclusively gluconeogenic (fbp, ppsA, pckA, maeB, sfcA, and glyoxylate shunt) in the best PTS- L-Phe overproducing strain (PB12-ev2). Furthermore, it was noticeable that most of the TCA genes showed a strong up-regulation in the presence of multicopy plasmids by an unknown mechanism. A group of genes exhibited transcriptional responses to both PTS inactivation

Long-wavelength TCF-based fluorescence probes for the detection and intracellular imaging of biological thiols.

PubMed

Sedgwick, Adam C; Gardiner, Jordan E; Kim, Gyoungmi; Yevglevskis, Maksims; Lloyd, Matthew D; Jenkins, A Toby A; Bull, Steven D; Yoon, Juyoung; James, Tony D

2018-05-08

Two 'turn on' TCF-based fluorescence probes were developed for the detection of biological thiols (TCF-GSH and TCFCl-GSH). TCF-GSH was shown to have a high sensitivity towards glutathione (GSH) with a 0.28 μM limit of detection. Unfortunately, at higher GSH concentrations the fluorescence intensity of TCF-GSH decreased and toxicity was observed for TCF-GSH in live cells. However, TCFCl-GSH was shown to be able to detect GSH at biologically relevant concentrations with a 0.45 μM limit of detection. No toxicity was found for TCFCl-GSH and a clear 'turn on' with good photostability was observed for the exogenous addition of GSH, Cys and HCys. Furthermore, TCFCl-GSH was used to evaluate the effects of drug treatment on the levels of GSH in live cells.

TCF3, a novel positive regulator of osteogenesis, plays a crucial role in miR-17 modulating the diverse effect of canonical Wnt signaling in different microenvironments

PubMed Central

Liu, W; Liu, Y; Guo, T; Hu, C; Luo, H; Zhang, L; Shi, S; Cai, T; Ding, Y; Jin, Y

2013-01-01

Wnt signaling pathways are a highly conserved pathway, which plays an important role from the embryonic development to bone formation. The effect of Wnt pathway on osteogenesis relies on their cellular environment and the expression of target genes. However, the molecular mechanism of that remains unclear. On the basis of the preliminary results, we observed the contrary effect of canonical Wnt signaling on osteogenic differentiation of periodontal ligament stem cells (PDLSCs) in the different culture environment. Furthermore, we found that the expression level of miR-17 was also varied with the change in the culture environment. Therefore, we hypothesized that miR-17 and canonical Wnt signaling may have potential interactions, particularly the inner regulation relationship in different microenvironments. In this paper, we observed that canonical Wnt signaling promoted osteogenesis of PDLSCs in the fully culture medium, while inhibited it in the osteogenic differentiation medium. Interestingly, alteration in the expression level of endogenous miR-17 could partially reverse the different effect of canonical Wnt signaling. Furthermore, the role of miR-17 was because of its target gene TCF3 (transcription factor 3), a key transcription factor of canonical Wnt pathway. Overexpression of TCF3 attenuated the effect of miR-17 on modulating canonical Wnt signaling. Finally, we elucidated that TCF3 enhanced osteogenesis both in vitro and in vivo. In brief, the different level of miR-17 was the main cause of the different effect of canonical Wnt signaling, and TCF3 was the crucial node of miR-17–canonial Wnt signaling regulation loop. This understanding of microRNAs regulating signaling pathways in different microenvironments may pave the way for fine-tuning the process of osteogenesis in bone-related disorders. PMID:23492770

TCF3, a novel positive regulator of osteogenesis, plays a crucial role in miR-17 modulating the diverse effect of canonical Wnt signaling in different microenvironments.

PubMed

Liu, W; Liu, Y; Guo, T; Hu, C; Luo, H; Zhang, L; Shi, S; Cai, T; Ding, Y; Jin, Y

2013-03-14

Wnt signaling pathways are a highly conserved pathway, which plays an important role from the embryonic development to bone formation. The effect of Wnt pathway on osteogenesis relies on their cellular environment and the expression of target genes. However, the molecular mechanism of that remains unclear. On the basis of the preliminary results, we observed the contrary effect of canonical Wnt signaling on osteogenic differentiation of periodontal ligament stem cells (PDLSCs) in the different culture environment. Furthermore, we found that the expression level of miR-17 was also varied with the change in the culture environment. Therefore, we hypothesized that miR-17 and canonical Wnt signaling may have potential interactions, particularly the inner regulation relationship in different microenvironments. In this paper, we observed that canonical Wnt signaling promoted osteogenesis of PDLSCs in the fully culture medium, while inhibited it in the osteogenic differentiation medium. Interestingly, alteration in the expression level of endogenous miR-17 could partially reverse the different effect of canonical Wnt signaling. Furthermore, the role of miR-17 was because of its target gene TCF3 (transcription factor 3), a key transcription factor of canonical Wnt pathway. Overexpression of TCF3 attenuated the effect of miR-17 on modulating canonical Wnt signaling. Finally, we elucidated that TCF3 enhanced osteogenesis both in vitro and in vivo. In brief, the different level of miR-17 was the main cause of the different effect of canonical Wnt signaling, and TCF3 was the crucial node of miR-17-canonial Wnt signaling regulation loop. This understanding of microRNAs regulating signaling pathways in different microenvironments may pave the way for fine-tuning the process of osteogenesis in bone-related disorders.

Salinity-mediated transcriptional and post-translational regulation of the Arabidopsis aquaporin PIP2;7.

PubMed

Pou, Alicia; Jeanguenin, Linda; Milhiet, Thomas; Batoko, Henri; Chaumont, François; Hachez, Charles

2016-12-01

Salt stress triggers a simultaneous transcriptional repression and aquaporin internalization to modify root cell water conductivity. Plasma membrane intrinsic proteins (PIPs) are involved in the adjustment of plant water balance in response to changing environmental conditions. In this study, Arabidopsis wild-type (Col-0) and transgenic lines overexpressing PIP2;7 were used to investigate and compare their response to salt stress. Hydraulic conductivity measurements using a high-pressure flowmeter (HPFM) revealed that overexpression of PIP2;7 induced a sixfold increase in root hydraulic conductivity of four week-old Arabidopsis thaliana plants compared to WT. Exposure to a high salt stress (150 mM NaCl) triggered a rapid repression of overall aquaporin activity in both genotypes. Response to salt stress was also investigated in 8 day-old seedlings. Exposure to salt led to a repression of PIP2;7 promoter activity and a significant decrease in PIP2;7 mRNA abundance within 2 h. Concomitantly, a rapid internalization of fluorescently-tagged PIP2;7 proteins was observed but removal from the cell membrane was not accompanied by further degradation of the protein within 4 h of exposure to salinity stress. These data suggest that PIP transcriptional repression and channel internalization act in concert during salt stress conditions to modulate aquaporin activity, thereby significantly altering the plant hydraulic parameters in the short term.

Embryonic stem cell-derived osteocytes are capable of responding to mechanical oscillatory hydrostatic pressure.

PubMed

Ehnes, D D; Price, F D; Shrive, N G; Hart, D A; Rancourt, D E; zur Nieden, N I

2015-07-16

Osteoblasts can be derived from embryonic stem cells (ESCs) by a 30 day differentiation process, whereupon cells spontaneously differentiate upon removal of LIF and respond to exogenously added 1,25α(OH)2 vitamin D3 with enhanced matrix mineralization. However, bone is a load-bearing tissue that has to perform under dynamic pressure changes during daily movement, a capacity that is executed by osteocytes. At present, it is unclear whether ESC-derived osteogenic cultures contain osteocytes and whether these are capable of responding to a relevant cyclic hydrostatic compression stimulus. Here, we show that ESC-osteoblastogenesis is followed by the generation of osteocytes and then mechanically load ESC-derived osteogenic cultures in a compression chamber using a cyclic loading protocol. Following mechanical loading of the cells, iNOS mRNA was upregulated 31-fold, which was consistent with a role for iNOS as an immediate early mechanoresponsive gene. Further analysis of matrix and bone-specific genes suggested a cellular response in favor of matrix remodeling. Immediate iNOS upregulation also correlated with a concomitant increase in Ctnnb1 and Tcf7l2 mRNAs along with increased nuclear TCF transcriptional activity, while the mRNA for the repressive Tcf7l1 was downregulated, providing a possible mechanistic explanation for the noted matrix remodeling. We conclude that ESC-derived osteocytes are capable of responding to relevant mechanical cues, at least such that mimic oscillatory compression stress, which not only provides new basic understanding, but also information that likely will be important for their use in cell-based regenerative therapies. Copyright © 2015 Elsevier Ltd. All rights reserved.

29 CFR 1627.7 - Transcriptions and reports.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 4 2011-07-01 2011-07-01 false Transcriptions and reports. 1627.7 Section 1627.7 Labor... § 1627.7 Transcriptions and reports. Every person required to maintain records under the Act shall make such extension, recomputation or transcriptions of his records and shall submit such reports concerning...

29 CFR 1627.7 - Transcriptions and reports.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 4 2010-07-01 2010-07-01 false Transcriptions and reports. 1627.7 Section 1627.7 Labor... § 1627.7 Transcriptions and reports. Every person required to maintain records under the Act shall make such extension, recomputation or transcriptions of his records and shall submit such reports concerning...

Dual control of pcdh8l/PCNS expression and function in Xenopus laevis neural crest cells by adam13/33 via the transcription factors tfap2α and arid3a.

PubMed

Khedgikar, Vikram; Abbruzzese, Genevieve; Mathavan, Ketan; Szydlo, Hannah; Cousin, Helene; Alfandari, Dominique

2017-08-22

Adam13/33 is a cell surface metalloprotease critical for cranial neural crest (CNC) cell migration. It can cleave multiple substrates including itself, fibronectin, ephrinB, cadherin-11, pcdh8 and pcdh8l (this work). Cleavage of cadherin-11 produces an extracellular fragment that promotes CNC migration. In addition, the adam13 cytoplasmic domain is cleaved by gamma secretase, translocates into the nucleus and regulates multiple genes. Here, we show that adam13 interacts with the arid3a/dril1/Bright transcription factor. This interaction promotes a proteolytic cleavage of arid3a and its translocation to the nucleus where it regulates another transcription factor: tfap2α. Tfap2α in turn activates multiple genes including the protocadherin pcdh8l (PCNS). The proteolytic activity of adam13 is critical for the release of arid3a from the plasma membrane while the cytoplasmic domain appears critical for the cleavage of arid3a. In addition to this transcriptional control of pcdh8l, adam13 cleaves pcdh8l generating an extracellular fragment that also regulates cell migration.

SOX7 Suppresses Wnt Signaling by Disrupting β-Catenin/BCL9 Interaction.

PubMed

Fan, Rong; He, HaiYan; Yao, Wang; Zhu, YanFeng; Zhou, XunJie; Gui, MingTai; Lu, Jing; Xi, Hao; Deng, ZhongLong; Fan, Min

2018-02-01

The Wnt signaling is involved in angiogenesis and tumor development. β-catenin is the core component of the Wnt pathway, which mediates oncogenic transcription and regulated by a series of proteins. Sex-determining region Y-box 7 (SOX7) is a member of high-mobility-group transcription factor family, which inhibits oncogenic Wnt signaling in lots of tumor cells with unknown mechanism. By coimmunoprecipitation (co-IP) and super Topflash reporter assay, SOX7 can bind β-catenin and inhibit β-catenin/T cell factor (TCF)-mediated transcription. Meanwhile, B cell lymphoma 9 (BCL9) drives Wnt signaling path through direct binding-mediated β-catenin. Finally, we found that SOX7 inhibits oncogenic β-catenin-mediated transcription by disrupting the β-catenin/BCL9 interaction. Mechanistically, SOX7 compete with BCL9 to bind β-catenin. Our results show SOX7 inhibited Wnt signaling as suppressor and could be an important target for anticancer therapy.

Sequential chemotherapy with dose-dense docetaxel, cisplatin, folinic acid and 5-fluorouracil (TCF-dd) followed by combination of oxaliplatin, folinic acid, 5-fluorouracil and irinotecan (COFFI) in metastatic gastric cancer: results of a phase II trial.

PubMed

Dalla Chiesa, Matteo; Tomasello, Gianluca; Buti, Sebastiano; Rovere, Rodrigo Kraft; Brighenti, Matteo; Lazzarelli, Silvia; Donati, Gianvito; Passalacqua, Rodolfo

2011-01-01

To evaluate a new strategy of two sequential, intensified chemotherapy regimens in metastatic gastric cancer. Chemo-naïve patients with metastatic gastric cancer were enrolled to receive 4 cycles of TCF-dd (docetaxel initially 85 mg/m(2) and cisplatin initially 75 mg/m(2) on day 1 [later modified due to toxicity: 70 and 60 mg/m(2) respectively], l-folinic acid 100 mg/m(2) on days 1 and 2, 5-fluorouracil 400 mg/m(2) bolus and then 600 mg/m(2) as a 22 h continuous infusion on day 1 and 2, every 14 days). Subsequently, patients with CR, PR or SD received 4 cycles of COFFI (oxaliplatin 85 mg/m(2), irinotecan 140 mg/m(2), l-folinic acid 200 mg/m(2), 5-fluorouracil bolus 400 mg/m(2) on day 1 followed by 2,400 mg/m(2) as a 48 h continuous infusion, every 14 days). In both regimens pegfilgrastim 6 mg subcutaneously on day 3 was included. Forty consecutive patients were enrolled. TCF-dd regimen achieved an ORR of 55% (95% CI, 40-70). Twenty-three patients proceeded to COFFI. After this regimen the ORR was then increased to 60% (95% CI, 45-75). Among the 21 patients treated with TCF-dd after the protocol amendments, main grade 3-4 toxicities were: neutropenia (29%), thrombocytopenia (19%), asthenia (24%) and diarrhea (14%). COFFI caused grade 3-4 neutropenia (all not febrile) and diarrhea in 35% and 17% of patients respectively. A sequential strategy with TCF-dd followed by COFFI is very active and may be of special interest in selected patients.

Androgens Up-regulate Transcription of the Notch Inhibitor Numb in C2C12 Myoblasts via Wnt/β-Catenin Signaling to T Cell Factor Elements in the Numb Promoter*

PubMed Central

Liu, Xin-Hua; Wu, Yong; Yao, Shen; Levine, Alice C.; Kirschenbaum, Alexander; Collier, Lauren; Bauman, William A.; Cardozo, Christopher P.

2013-01-01

Androgen signaling via the androgen receptor is a key pathway that contributes to development, cell fate decisions, and differentiation, including that of myogenic progenitors. Androgens and synthetic steroids have well established anabolic actions on skeletal muscle. Wnt and Notch signaling pathways are also essential to myogenic cell fate decisions during development and tissue repair. However, the interactions among these pathways are largely unknown. Androgenic regulation of Wnt signaling has been reported. Nandrolone, an anabolic steroid, has been shown to inhibit Notch signaling and up-regulate Numb, a Notch inhibitor. To elucidate the mechanisms of interaction between nandrolone and Wnt/Notch signaling, we investigated the effects of nandrolone on Numb expression and Wnt signaling and determined the roles of Wnt signaling in nandrolone-induced Numb expression in C2C12 myoblasts. Nandrolone increased Numb mRNA and protein levels and T cell factor (Tcf) transcriptional activity via inhibition of glycogen synthase kinase 3β. Up-regulation of Numb expression by nandrolone was blocked by the Wnt inhibitors, sFRP1 and DKK1, whereas Wnt3a increased Numb mRNA and protein expression. In addition, we observed that the proximal promoter of the Numb gene had functional Tcf binding elements to which β-catenin was recruited in a manner enhanced by both nandrolone and Wnt3a. Moreover, site-directed mutagenesis indicated that the Tcf binding sites in the Numb promoter are required for the nandrolone-induced Numb transcriptional activation in this cell line. These results reveal a novel molecular mechanism underlying up-regulation of Numb transcription with a critical role for increased canonical Wnt signaling. In addition, the data identify Numb as a novel target gene of the Wnt signaling pathway by which Wnts would be able to inhibit Notch signaling. PMID:23649620

Listeria monocytogenes grown at 7° C shows reduced acid survival and an altered transcriptional response to acid shock compared to L. monocytogenes grown at 37° C.

PubMed

Ivy, R A; Wiedmann, M; Boor, K J

2012-06-01

Survival of the food-borne pathogen Listeria monocytogenes in acidic environments (e.g., in the human stomach) is vital to its transmission. Refrigerated, ready-to-eat foods have been sources of listeriosis outbreaks. The purpose of this study was to determine whether growth at a low temperature (i.e., 7°C) affects L. monocytogenes survival or gene transcription after exposure to a simulated gastric environment (i.e., acid shock at 37°C). L. monocytogenes cells grown at 7°C were less resistant to artificial gastric fluid (AGF) or acidified brain heart infusion broth (ABHI) than bacteria grown at higher temperatures (i.e., 30°C or 37°C). For L. monocytogenes grown at 7°C, stationary-phase cells were more resistant to ABHI than log-phase cells, indicating that both temperature and growth phase affect acid survival. Microarray transcriptomic analysis revealed that the number and functional categories of genes differentially expressed after acid shock differed according to both growth temperature and growth phase. The acid response of L. monocytogenes grown to log phase at 37°C involved stress-related transcriptional regulators (i.e., σ(B), σ(H), CtsR, and HrcA), some of which have been implicated in adaptation to the intracellular environment. In contrast, for bacteria grown at 7°C to stationary phase, acid exposure did not result in differential expression of the stress regulons examined. However, two large operons encoding bacteriophage-like proteins were induced, suggesting lysogenic prophage induction. The adaptive transcriptional response observed in 37°C-grown cells was largely absent in 7°C-grown cells, suggesting that temperatures commonly encountered during food storage and distribution affect the ability of L. monocytogenes to survive gastric passage and ultimately cause disease.

LaAP2L1, a heterosis-associated AP2/EREBP transcription factor of Larix, increases organ size and final biomass by affecting cell proliferation in Arabidopsis.

PubMed

Li, Ai; Zhou, Yanan; Jin, Chuan; Song, Wenqin; Chen, Chengbin; Wang, Chunguo

2013-11-01

In Larix and in some crops, heterosis is prevalent and has been widely used in breeding to produce excellent varieties. However, the molecular basis of heterosis in Larix remains ambiguous. LaAP2L1, a member of the AP2/EREBP transcription factor family, has been suggested to be involved in heterosis in Larix hybrids. Here, the function and regulation of LaAP2L1 were further explored. Overexpression of LaAP2L1 led to markedly enlarged organs and heterosis-like traits in Arabidopsis. Fresh weight of leaves was almost twice as great as in vector controls. Likewise, seed yield of 35S::LaAP2L1 individual plants was >200% greater than that of control plants. The enlarged organs and heterosis-like traits displayed by 35S::LaAP2L1 plants were mainly due to enhanced cell proliferation and prolonged growth duration. At the molecular level, LaAP2L1 upregulated the expression of ANT, EBP1, and CycD3;1 and inhibited the expression of ARGOS in 35S::LaAP2L1 plants, suggesting an important molecular role of LaAP2L1 in regulating plant organ development. These findings provide new insights into the formation of heterosis in woody plants and suggest that LaAP2L1 has potential applications in breeding high-yielding crops and energy plants. In addition, 50 AP2/EREBP transcription factors, including LaAP2L1, in Larix were identified by transcriptome sequencing, and phylogenetic analysis was conducted. This provided information that will be important in further revealing the functions of these transcription factors.

Dual control of pcdh8l/PCNS expression and function in Xenopus laevis neural crest cells by adam13/33 via the transcription factors tfap2α and arid3a

PubMed Central

Khedgikar, Vikram; Abbruzzese, Genevieve; Mathavan, Ketan; Szydlo, Hannah; Cousin, Helene

2017-01-01

Adam13/33 is a cell surface metalloprotease critical for cranial neural crest (CNC) cell migration. It can cleave multiple substrates including itself, fibronectin, ephrinB, cadherin-11, pcdh8 and pcdh8l (this work). Cleavage of cadherin-11 produces an extracellular fragment that promotes CNC migration. In addition, the adam13 cytoplasmic domain is cleaved by gamma secretase, translocates into the nucleus and regulates multiple genes. Here, we show that adam13 interacts with the arid3a/dril1/Bright transcription factor. This interaction promotes a proteolytic cleavage of arid3a and its translocation to the nucleus where it regulates another transcription factor: tfap2α. Tfap2α in turn activates multiple genes including the protocadherin pcdh8l (PCNS). The proteolytic activity of adam13 is critical for the release of arid3a from the plasma membrane while the cytoplasmic domain appears critical for the cleavage of arid3a. In addition to this transcriptional control of pcdh8l, adam13 cleaves pcdh8l generating an extracellular fragment that also regulates cell migration. PMID:28829038

E-Cadherin Acts as a Regulator of Transcripts Associated with a Wide Range of Cellular Processes in Mouse Embryonic Stem Cells

PubMed Central

Soncin, Francesca; Mohamet, Lisa; Ritson, Sarah; Hawkins, Kate; Bobola, Nicoletta; Zeef, Leo; Merry, Catherine L. R.; Ward, Christopher M.

2011-01-01

Background We have recently shown that expression of the cell adhesion molecule E-cadherin is required for LIF-dependent pluripotency of mouse embryonic stem (ES) cells. Methodology In this study, we have assessed global transcript expression in E-cadherin null (Ecad-/-) ES cells cultured in either the presence or absence of LIF and compared these to the parental cell line wtD3. Results We show that LIF has little effect on the transcript profile of Ecad-/- ES cells, with statistically significant transcript alterations observed only for Sp8 and Stat3. Comparison of Ecad-/- and wtD3 ES cells cultured in LIF demonstrated significant alterations in the transcript profile, with effects not only confined to cell adhesion and motility but also affecting, for example, primary metabolic processes, catabolism and genes associated with apoptosis. Ecad-/- ES cells share similar, although not identical, gene expression profiles to epiblast-derived pluripotent stem cells, suggesting that E-cadherin expression may inhibit inner cell mass to epiblast transition. We further show that Ecad-/- ES cells maintain a functional β-catenin pool that is able to induce β-catenin/TCF-mediated transactivation but, contrary to previous findings, do not display endogenous β-catenin/TCF-mediated transactivation. We conclude that loss of E-cadherin in mouse ES cells leads to significant transcript alterations independently of β-catenin/TCF transactivation. PMID:21779327

E-cadherin acts as a regulator of transcripts associated with a wide range of cellular processes in mouse embryonic stem cells.

PubMed

Soncin, Francesca; Mohamet, Lisa; Ritson, Sarah; Hawkins, Kate; Bobola, Nicoletta; Zeef, Leo; Merry, Catherine L R; Ward, Christopher M

2011-01-01

We have recently shown that expression of the cell adhesion molecule E-cadherin is required for LIF-dependent pluripotency of mouse embryonic stem (ES) cells. In this study, we have assessed global transcript expression in E-cadherin null (Ecad-/-) ES cells cultured in either the presence or absence of LIF and compared these to the parental cell line wtD3. We show that LIF has little effect on the transcript profile of Ecad-/- ES cells, with statistically significant transcript alterations observed only for Sp8 and Stat3. Comparison of Ecad-/- and wtD3 ES cells cultured in LIF demonstrated significant alterations in the transcript profile, with effects not only confined to cell adhesion and motility but also affecting, for example, primary metabolic processes, catabolism and genes associated with apoptosis. Ecad-/- ES cells share similar, although not identical, gene expression profiles to epiblast-derived pluripotent stem cells, suggesting that E-cadherin expression may inhibit inner cell mass to epiblast transition. We further show that Ecad-/- ES cells maintain a functional β-catenin pool that is able to induce β-catenin/TCF-mediated transactivation but, contrary to previous findings, do not display endogenous β-catenin/TCF-mediated transactivation. We conclude that loss of E-cadherin in mouse ES cells leads to significant transcript alterations independently of β-catenin/TCF transactivation.

A Meta-Analysis of Hodgkin Lymphoma Reveals 19p13.3 TCF3 as a Novel Susceptibility Locus

PubMed Central

Cozen, W; Timofeeva, MN; Li, D; Diepstra, A; Hazelett, D; Delahaye-Sourdeix, M; Edlund, CK; Franke, L; Rostgaard, K; Van Den Berg, DJ; Cortessis, VK; Smedby, KE; Glaser, SL; H-J, Westra; Robison, LL; Mack, TM; Ghesquieres, H; Hwang, AE; Nieters, A; de Sanjose, S; Lightfoot, T; Becker, N; Maynadie, M; Foretova, L; Roman, E; Benavente, Y; Rand, KA; Nathwani, BN; Glimelius, B; Staines, A; Boffetta, P; Link, BK; Kiemeney, L; Ansell, SM; Bhatia, S; Strong, LC; Galan, P; Vatten, L; Habermann, TM; Duell, EJ; Lake, A; Veenstra, RN; Visser, L; Liu, Y; Urayama, KY; Montgomery, D; Gaborieau, V; Weiss, LM; Byrnes, G; Lathrop, M; Cocco, P; Best, T; Skol, AD; H-O, Adami; Melbye, M; Cerhan, JR; Gallagher, A; Taylor, GM; Slager, SL; Brennan, P; Coetzee, GA; Conti, DV; Onel, K; Jarrett, RF; Hjalgrim, H; van den Berg, A; McKay, JD

2014-01-01

Recent genome wide association studies (GWAS) of Hodgkin lymphoma (HL) have identified associations with genetic variation at both HLA and non-HLA loci; however, much of heritable HL susceptibility remains unexplained. Here we perform a meta-analysis of three HL GWAS totaling 1,816 cases and 7,877 controls followed by replication in an independent set of 1,281 cases and 3,218 controls to find novel risk loci. We identify a novel variant at 19p13.3 associated with HL (rs1860661; odds ratio [OR] = 0.81, 95% confidence interval [95% CI] = 0.76–0.86, Pcombined = 3.5 × 10−10), located in intron 2 of TCF3 (also known as E2A), a regulator of B- and T-cell lineage commitment known to be involved in HL pathogenesis. This meta-analysis also notes associations between previously published loci at 2p16.1, 5q31, 6p31.2, 8q24.21 and 10p14 and HL subtypes. We conclude that our data suggest a link between the 19p13.3 locus, including TCF3, and HL risk PMID:24920014

Transcriptional profiling of rat white adipose tissue response to 2,3,7,8-tetrachlorodibenzo-ρ-dioxin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Houlahan, Kathleen E.; Prokopec, Stephenie D.; Sun, Ren X.

Polychlorinated dibenzodioxins are environmental contaminants commonly produced as a by-product of industrial processes. The most potent of these, 2,3,7,8-tetrachlorodibenzo-ρ-dioxin (TCDD), is highly lipophilic, leading to bioaccumulation. White adipose tissue (WAT) is a major site for energy storage, and is one of the organs in which TCDD accumulates. In laboratory animals, exposure to TCDD causes numerous metabolic abnormalities, including a wasting syndrome. We therefore investigated the molecular effects of TCDD exposure on WAT by profiling the transcriptomic response of WAT to 100 μg/kg of TCDD at 1 or 4 days in TCDD-sensitive Long-Evans (Turku/AB; L-E) rats. A comparative analysis was conductedmore » simultaneously in identically treated TCDD-resistant Han/Wistar (Kuopio; H/W) rats one day after exposure to the same dose. We sought to identify transcriptomic changes coinciding with the onset of toxicity, while gaining additional insight into later responses. More transcriptional responses to TCDD were observed at 4 days than at 1 day post-exposure, suggesting WAT shows mostly secondary responses. Two classic AHR-regulated genes, Cyp1a1 and Nqo1, were significantly induced by TCDD in both strains, while several genes involved in the immune response, including Ms4a7 and F13a1 were altered in L-E rats alone. We compared genes affected by TCDD in rat WAT and human adipose cells, and observed little overlap. Interestingly, very few genes involved in lipid metabolism exhibited altered expression levels despite the pronounced lipid mobilization from peripheral fat pads by TCDD in L-E rats. Of these genes, the lipolysis-associated Lpin1 was induced slightly over 2-fold in L-E rat WAT on day 4. - Highlights: • Exposure to TCDD causes wasting syndrome in L-E rats but not in H/W rats. • We examined the transcriptome of TCDD-treated L-E and H/W rat white adipose tissue. • L-E WAT demonstrated altered abundance of several genes involved in immune response. �

The RNA-binding proteins Zfp36l1 and Zfp36l2 enforce the thymic β-selection checkpoint by limiting DNA damage response signaling and cell cycle progression

PubMed Central

Galloway, Alison; Ahlfors, Helena; Turner, Martin

2016-01-01

The RNA binding proteins Zfp36l1 and Zfp36l2 act redundantly to enforce the β-selection checkpoint during thymopoiesis, yet their molecular targets remain largely unknown. Here, we identify these targets on a genome wide scale in primary mouse thymocytes and show that Zfp36l1/l2 regulate DNA damage response and cell cycle transcripts to ensure proper β-selection. DN3 thymocytes lacking Zfp36l1/l2 share a gene expression profile with post-selected DN3b cells despite the absence of intracellular TCRβ and reduced IL-7 signaling. Our findings show that in addition to controlling the timing of proliferation at β-selection post-transcriptional control by Zfp36l1/l2 limits DNA damage responses which are known to promote thymocyte differentiation. Zfp36l1/l2 therefore act as post-transcriptional safeguards against chromosomal instability and replication stress by integrating pre-TCR and IL-7 signaling with DNA damage and cell cycle control. PMID:27566829

Transcriptional changes in porcine skin at 7 days following sulfur mustard and thermal burn injury.

PubMed

Price, Jennifer A; Rogers, James V; McDougal, James N; Shaw, Morgan Q; Reid, Frances M; Graham, John S

2009-01-01

Severe cutaneous injuries continue to result from exposure to sulfur mustard [bis(2-chloroethyl)sulfide; HD] and thermal burns. Microarray analysis was utilized in this study to evaluate transcriptional changes in porcine skin assessing the underlying repair mechanisms of HD and thermal injury involved in wound healing. Four ventral abdominal sites on each of 4 weanling swine were exposed to 400 microL undiluted HD or a heated brass rod (70 degrees C) for 8 minutes and 45-60 seconds, respectively. At 7 days postexposure, skin samples were excised and total RNA was isolated, labeled, and hybridized to Affymetrix GeneChip (Santa Clara, CA, USA) Porcine Genome Arrays (containing 20,201 genes). Based on the gene expression patterns in HD- and thermal-exposed skin at 7 days, the transcriptional profiles do not differ greatly. HD and thermal exposures promoted similar changes in transcription, where 270 and 283 transcripts were increased with HD and thermal exposures, respectively. Both exposures promoted decreases in 317 and 414 transcripts, respectively. Of the significantly increased transcripts, at least 77% were commonly expressed in both HD- and thermal-exposed skin, whereas at least 67% of decreased transcripts were common between both exposure types. Six of the top 10 biological functions were common to HD and thermal injury in which 9 canonical pathways were shared. The present study illustrates the similarities found between HD and thermal injury with respect to transcriptional response and wound healing and identifies specific genes (CXCL2, CXCR4, FGFR2, HMOX1, IGF1, PF4, PLAU, PLAUR, S100A8, SPP1, and TNC) that may be useful as potential therapeutic targets to promote improved wound healing.

Expanding the mutation spectrum in 182 Spanish probands with craniosynostosis: identification and characterization of novel TCF12 variants

PubMed Central

Paumard-Hernández, Beatriz; Berges-Soria, Julia; Barroso, Eva; Rivera-Pedroza, Carlos I; Pérez-Carrizosa, Virginia; Benito-Sanz, Sara; López-Messa, Eva; Santos, Fernando; García-Recuero, Ignacio I; Romance, Ana; Ballesta-Martínez, Juliana María; López-González, Vanesa; Campos-Barros, Ángel; Cruz, Jaime; Guillén-Navarro, Encarna; Sánchez del Pozo, Jaime; Lapunzina, Pablo; García-Miñaur, Sixto; Heath, Karen E

2015-01-01

Craniosynostosis, caused by the premature fusion of one or more of the cranial sutures, can be classified into non-syndromic or syndromic and by which sutures are affected. Clinical assignment is a difficult challenge due to the high phenotypic variability observed between syndromes. During routine diagnostics, we screened 182 Spanish craniosynostosis probands, implementing a four-tiered cascade screening of FGFR2, FGFR3, FGFR1, TWIST1 and EFNB1. A total of 43 variants, eight novel, were identified in 113 (62%) patients: 104 (92%) detected in level 1; eight (7%) in level 2 and one (1%) in level 3. We subsequently screened additional genes in the probands with no detected mutation: one duplication of the IHH regulatory region was identified in a patient with craniosynostosis Philadelphia type and five variants, four novel, were identified in the recently described TCF12, in probands with coronal or multisuture affectation. In the 19 Saethre–Chotzen syndrome (SCS) individuals in whom a variant was detected, 15 (79%) carried a TWIST1 variant, whereas four (21%) had a TCF12 variant. Thus, we propose that TCF12 screening should be included for TWIST1 negative SCS patients and in patients where the coronal suture is affected. In summary, a molecular diagnosis was obtained in a total of 119/182 patients (65%), allowing the correct craniosynostosis syndrome classification, aiding genetic counselling and in some cases provided a better planning on how and when surgical intervention should take place and, subsequently the appropriate clinical follow up. PMID:25271085

OsMYB103L, an R2R3-MYB transcription factor, influences leaf rolling and mechanical strength in rice (Oryza sativa L.).

PubMed

Yang, Chunhua; Li, Dayong; Liu, Xue; Ji, Chengjun; Hao, Lili; Zhao, Xianfeng; Li, Xiaobing; Chen, Caiyan; Cheng, Zhukuan; Zhu, Lihuang

2014-06-06

The shape of grass leaves possesses great value in both agronomy and developmental biology research. Leaf rolling is one of the important traits in rice (Oryza sativa L.) breeding. MYB transcription factors are one of the largest gene families and have important roles in plant development, metabolism and stress responses. However, little is known about their functions in rice. In this study, we report the functional characterization of a rice gene, OsMYB103L, which encodes an R2R3-MYB transcription factor. OsMYB103L was localized in the nucleus with transactivation activity. Overexpression of OsMYB103L in rice resulted in a rolled leaf phenotype. Further analyses showed that expression levels of several cellulose synthase genes (CESAs) were significantly increased, as was the cellulose content in OsMYB103L overexpressing lines. Knockdown of OsMYB103L by RNA interference led to a decreased level of cellulose content and reduced mechanical strength in leaves. Meanwhile, the expression levels of several CESA genes were decreased in these knockdown lines. These findings suggest that OsMYB103L may target CESA genes for regulation of cellulose synthesis and could potentially be engineered for desirable leaf shape and mechanical strength in rice.

A Single Nucleotide Polymorphism Uncovers a Novel Function for the Transcription Factor Ace2 during Candida albicans Hyphal Development

PubMed Central

Orellana-Muñoz, Sara; Gutiérrez-Escribano, Pilar; Arnáiz-Pita, Yolanda; Dueñas-Santero, Encarnación; Suárez, M. Belén; Bougnoux, Marie-Elisabeth; del Rey, Francisco; Sherlock, Gavin; d’Enfert, Christophe; Correa-Bordes, Jaime; de Aldana, Carlos R. Vázquez

2015-01-01

Candida albicans is a major invasive fungal pathogen in humans. An important virulence factor is its ability to switch between the yeast and hyphal forms, and these filamentous forms are important in tissue penetration and invasion. A common feature for filamentous growth is the ability to inhibit cell separation after cytokinesis, although it is poorly understood how this process is regulated developmentally. In C. albicans, the formation of filaments during hyphal growth requires changes in septin ring dynamics. In this work, we studied the functional relationship between septins and the transcription factor Ace2, which controls the expression of enzymes that catalyze septum degradation. We found that alternative translation initiation produces two Ace2 isoforms. While full-length Ace2, Ace2L, influences septin dynamics in a transcription-independent manner in hyphal cells but not in yeast cells, the use of methionine-55 as the initiation codon gives rise to Ace2S, which functions as the nuclear transcription factor required for the expression of cell separation genes. Genetic evidence indicates that Ace2L influences the incorporation of the Sep7 septin to hyphal septin rings in order to avoid inappropriate activation of cell separation during filamentous growth. Interestingly, a natural single nucleotide polymorphism (SNP) present in the C. albicans WO-1 background and other C. albicans commensal and clinical isolates generates a stop codon in the ninth codon of Ace2L that mimics the phenotype of cells lacking Ace2L. Finally, we report that Ace2L and Ace2S interact with the NDR kinase Cbk1 and that impairing activity of this kinase results in a defect in septin dynamics similar to that of hyphal cells lacking Ace2L. Together, our findings identify Ace2L and the NDR kinase Cbk1 as new elements of the signaling system that modify septin ring dynamics in hyphae to allow cell-chain formation, a feature that appears to have evolved in specific C. albicans lineages

Tcf3 and cell cycle factors contribute to butyrate resistance in colorectal cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiaro, Christopher, E-mail: cchiaro@tcmedc.org; Lazarova, Darina L., E-mail: dlazarova@tcmedc.org; Bordonaro, Michael, E-mail: mbordonaro@tcmedc.org

2012-11-09

Highlights: Black-Right-Pointing-Pointer We investigate mechanisms responsible for butyrate resistance in colon cancer cells. Black-Right-Pointing-Pointer Tcf3 modulates butyrate's effects on Wnt activity and cell growth in resistant cells. Black-Right-Pointing-Pointer Tcf3 modulation of butyrate's effects differ by cell context. Black-Right-Pointing-Pointer Cell cycle factors are overexpressed in the resistant cells. Black-Right-Pointing-Pointer Reversal of altered gene expression can enhance the anti-cancer effects of butyrate. -- Abstract: Butyrate, a fermentation product of dietary fiber, inhibits clonal growth in colorectal cancer (CRC) cells dependent upon the fold induction of Wnt activity. We have developed a CRC cell line (HCT-R) that, unlike its parental cell line, HCT-116,more » does not respond to butyrate exposure with hyperactivation of Wnt signaling and suppressed clonal growth. PCR array analyses revealed Wnt pathway-related genes, the expression of which differs between butyrate-sensitive HCT-116 CRC cells and their butyrate-resistant HCT-R cell counterparts. We identified overexpression of Tcf3 as being partially responsible for the butyrate-resistant phenotype, as this DNA-binding protein suppresses the hyperinduction of Wnt activity by butyrate. Consequently, Tcf3 knockdown in HCT-R cells restores their sensitivity to the effects of butyrate on Wnt activity and clonal cell growth. Interestingly, the effects of overexpressed Tcf3 differ between HCT-116 and HCT-R cells; thus, in HCT-116 cells Tcf3 suppresses proliferation without rendering the cells resistant to butyrate. In HCT-R cells, however, the overexpression of Tcf3 inhibits Wnt activity, and the cells are still able to proliferate due to the higher expression levels of cell cycle factors, particularly those driving the G{sub 1} to S transition. Knowledge of the molecular mechanisms determining the variable sensitivity of CRC cells to butyrate may assist in developing approaches that

JS-K, a nitric oxide-releasing prodrug, modulates ß-catenin/TCF signaling in leukemic Jurkat cells: evidence of an S-nitrosylated mechanism.

PubMed

Nath, Niharika; Chattopadhyay, Mitali; Pospishil, Liliya; Cieciura, Lucyna Z; Goswami, Satindra; Kodela, Ravinder; Saavedra, Joseph E; Keefer, Larry K; Kashfi, Khosrow

2010-12-01

β-Catenin is a central player of the Wnt signaling pathway that regulates cell-cell adhesion and may promote leukemia cell proliferation. We examined whether JS-K, an NO-donating prodrug, modulates the Wnt/β-catenin/TCF-4 signaling pathway in Jurkat T-Acute Lymphoblastic Leukemia cells. JS-K inhibited Jurkat T cell growth in a concentration and time-dependent manner. The IC(50)s for cell growth inhibition were 14±0.7 and 9±1.2μM at 24 and 48h, respectively. Treatment of the cells with JS-K for 24h, caused a dose-dependent increase in apoptosis from 16±3.3% at 10μM to 74.8±2% at 100μM and a decrease in proliferation. This growth inhibition was also due, in part, to alterations in the different phases of the cell cycle. JS-K exhibited a dose-dependent cytotoxicity as measured by LDH release at 24h. However, between 2 and 8h, LDH release was less than 20% for any indicated JS-K concentration. The β-catenin/TCF-4 transcriptional inhibitory activity was reduced by 32±8, 63±5, and 93±2% at 2, 10, and 25μM JS-K, respectively, based on luciferase reporter assays. JS-K reduced nuclear β-catenin and cyclin D1 protein levels, but cytosolic β-catenin expression did not change. Based on a time-course assay of S-nitrosylation of proteins by a biotin switch assay, S-nitrsolyation of nuclear β-catenin was determined to precede its degradation. A comparison of the S-nitrosylated nuclear β-catenin to the total nuclear β-catenin showed that β-catenin protein levels were degraded at 24h, while S-nitrosylation of β-catenin occurred earlier at 0-6h. The NO scavenger PTIO abrogated the JS-K mediated degradation of β-catenin demonstrating the need for NO. Copyright © 2010 Elsevier Inc. All rights reserved.

Pervasive Transcription of a Herpesvirus Genome Generates Functionally Important RNAs

PubMed Central

Canny, Susan P.; Reese, Tiffany A.; Johnson, L. Steven; Zhang, Xin; Kambal, Amal; Duan, Erning; Liu, Catherine Y.; Virgin, Herbert W.

2014-01-01

ABSTRACT Pervasive transcription is observed in a wide range of organisms, including humans, mice, and viruses, but the functional significance of the resulting transcripts remains uncertain. Current genetic approaches are often limited by their emphasis on protein-coding open reading frames (ORFs). We previously identified extensive pervasive transcription from the murine gammaherpesvirus 68 (MHV68) genome outside known ORFs and antisense to known genes (termed expressed genomic regions [EGRs]). Similar antisense transcripts have been identified in many other herpesviruses, including Kaposi’s sarcoma-associated herpesvirus and human and murine cytomegalovirus. Despite their prevalence, whether these RNAs have any functional importance in the viral life cycle is unknown, and one interpretation is that these are merely “noise” generated by functionally unimportant transcriptional events. To determine whether pervasive transcription of a herpesvirus genome generates RNA molecules that are functionally important, we used a strand-specific functional approach to target transcripts from thirteen EGRs in MHV68. We found that targeting transcripts from six EGRs reduced viral protein expression, proving that pervasive transcription can generate functionally important RNAs. We characterized transcripts emanating from EGRs 26 and 27 in detail using several methods, including RNA sequencing, and identified several novel polyadenylated transcripts that were enriched in the nuclei of infected cells. These data provide the first evidence of the functional importance of regions of pervasive transcription emanating from MHV68 EGRs. Therefore, studies utilizing mutation of a herpesvirus genome must account for possible effects on RNAs generated by pervasive transcription. PMID:24618256

Foot-and-mouth disease virus leader proteinase inhibits dsRNA-induced type I interferon transcription by decreasing interferon regulatory factor 3/7 in protein levels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Dang; Fang, Liurong; Luo, Rui

2010-08-13

Research highlights: {yields} FMDV L{sup pro} inhibits poly(I:C)-induced IFN-{alpha}1/{beta} mRNA expression. {yields} L{sup pro} inhibits MDA5-mediated activation of the IFN-{alpha}1/{beta} promoter. {yields} L{sup pro} significantly reduced the transcription of multiple IRF-responsive genes. {yields} L{sup pro} inhibits IFN-{alpha}1/{beta} promoter activation by decreasing IRF-3/7 in protein levels. {yields} The ability to process eIF-4G of L{sup pro} is not necessary to inhibit IFN-{alpha}1/{beta} activation. -- Abstract: The leader proteinase (L{sup pro}) of foot-and-mouth disease virus (FMDV) has been identified as an interferon-{beta} (IFN-{beta}) antagonist that disrupts the integrity of transcription factor nuclear factor {kappa}B (NF-{kappa}B). In this study, we showed that the reductionmore » of double stranded RNA (dsRNA)-induced IFN-{alpha}1/{beta} expression caused by L{sup pro} was also associated with a decrease of interferon regulatory factor 3/7 (IRF-3/7) in protein levels, two critical transcription factors for activation of IFN-{alpha}/{beta}. Furthermore, overexpression of L{sup pro} significantly reduced the transcription of multiple IRF-responsive genes including 2',5'-OAS, ISG54, IP-10, and RANTES. Screening L{sup pro} mutants indicated that the ability to process eIF-4G of L{sup pro} is not required for suppressing dsRNA-induced activation of the IFN-{alpha}1/{beta} promoter and decreasing IRF-3/7 expression. Taken together, our results demonstrate that, in addition to disrupting NF-{kappa}B, L{sup pro} also decreases IRF-3/7 expression to suppress dsRNA-induced type I IFN production, suggesting multiple strategies used by FMDV to counteract the immune response to viral infection.« less

Wnt/β-catenin pathway regulates Bmp2-mediated differentiation of dental follicle cells

PubMed Central

Silvério, Karina G.; Davidson, Kathryn C.; James, Richard G.; Adams, Allison M.; Foster, Brian L.; Nociti, Francisco H.; Somermam, Martha J.; Moon, Randall T.

2013-01-01

Background and Objectives Bmp2-induced osteogenic differentiation has been shown to occur through the canonical Wnt/β-catenin pathway, whereas factors promoting canonical Wnt signaling in cementoblasts inhibited cell differentiation and promoted cell proliferation in vitro. The aim of this study was to investigate whether putative precursor cells of cementoblasts, dental follicle cells (murine SVF4 cells), when stimulated with Bmp2, would exhibit changes in genes/proteins associated with the Wnt/β-catenin pathway. Materials and Methods SVF4 cells were stimulated with Bmp2, and the following assays were carried out: 1) Wnt/β-catenin pathway activation assessed by western blot, β-catenin/TCF reporter assay, and gene expression of lymphoid enhancer-binding factor-1 (Lef1), transcription factor 7 (Tcf7), Wnt inhibitor factor 1 (Wif1) and Axin2, and 2) cementoblast/osteoblast differentiation assessed by mineralization in vitro, and mRNA levels of runt-related transcription factor 2 (Runx2), osterix (Osx), alkaline phosphatase (Alp), osteocalcin (Ocn) and bone sialoprotein (Bsp) by qPCR after Wnt3a treatment and knockdown of β-catenin. Results Wnt3a induced β-catenin nuclear translocation and upregulated the transcriptional activity of a canonical Wnt-responsive reporter, suggesting the Wnt/β-catenin pathway functions in SVF4 cells. Activation of Wnt signaling with Wnt3a suppressed Bmp2-mediated induction of cementoblast/osteoblast maturation of SVF4 cells. However, β-catenin knockdown showed that Bmp2-induced expression of cementoblast/osteoblast differentiation markers requires endogenous β-catenin. Wnt3a down-regulated transcripts for Runx2, Alp and Ocn in SVF4 cells compared to untreated cells. In contrast, Bmp2 induction of Bsp transcripts occurred independent of Wnt/β-catenin signaling. Conclusions These data suggest that stabilization of β-catenin by Wnt-3a treatment inhibits Bmp2-mediated induction of cementoblast/osteoblast differentiation in SVF4

Identification of the Transformational Properties and Transcriptional Targets of the Oncogenic SRY Transcription Factor SOX4

DTIC Science & Technology

2009-01-01

has also been implicated in tumorigenesis of multiple tumor types and has been shown by our lab to be upregulated in prostate cancer. However, the...mobility group (HMG) DNA-binding domain (DBD) related to the TCF/LEF family of transcription factors. Our lab has previously shown SOX4 mRNA and...protein to be overexpressed in prostate cancer, and this expression is correlated with increasing Gleason score. Other labs have shown SOX4 mRNA to be

The role of the Wnt signaling pathway in incretin hormone production and function

PubMed Central

Chiang, Yu-ting A.; Ip, Wilfred; Jin, Tianru

2012-01-01

Glucose metabolism is tightly controlled by multiple hormones and neurotransmitters in response to nutritional, environmental, and emotional changes. In addition to insulin and glucagon produced by pancreatic islets, two incretin hormones, namely glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP, also known as glucose-dependent insulinotropic peptide), also play important roles in blood glucose homeostasis. The incretin hormones mainly exert their regulatory effects via their corresponding receptors, which are expressed in pancreatic islets as well as many other extra-pancreatic organs. Recent studies have shown that the genes which encode these two incretin hormones can be regulated by the effectors of the Wnt signaling pathway, including TCF7L2, a transcription factor identified recently by extensive genome wide association studies as an important type 2 diabetes risk gene. Interestingly, TCF7L2 and β-catenin (β-cat), another effector of Wnt signaling pathway, may also mediate the function of the incretin hormones as well as the expression of their receptors in pancreatic β-cells. In this review, we have introduced the incretin hormones and the Wnt signaling pathway, summarized recent findings in the field, and provided our perspectives. PMID:22934027

A Positive Regulatory Loop between a Wnt-Regulated Non-coding RNA and ASCL2 Controls Intestinal Stem Cell Fate.

PubMed

Giakountis, Antonis; Moulos, Panagiotis; Zarkou, Vasiliki; Oikonomou, Christina; Harokopos, Vaggelis; Hatzigeorgiou, Artemis G; Reczko, Martin; Hatzis, Pantelis

2016-06-21

The canonical Wnt pathway plays a central role in stem cell maintenance, differentiation, and proliferation in the intestinal epithelium. Constitutive, aberrant activity of the TCF4/β-catenin transcriptional complex is the primary transforming factor in colorectal cancer. We identify a nuclear long non-coding RNA, termed WiNTRLINC1, as a direct target of TCF4/β-catenin in colorectal cancer cells. WiNTRLINC1 positively regulates the expression of its genomic neighbor ASCL2, a transcription factor that controls intestinal stem cell fate. WiNTRLINC1 interacts with TCF4/β-catenin to mediate the juxtaposition of its promoter with the regulatory regions of ASCL2. ASCL2, in turn, regulates WiNTRLINC1 transcriptionally, closing a feedforward regulatory loop that controls stem cell-related gene expression. This regulatory circuitry is highly amplified in colorectal cancer and correlates with increased metastatic potential and decreased patient survival. Our results uncover the interplay between non-coding RNA-mediated regulation and Wnt signaling and point to the diagnostic and therapeutic potential of WiNTRLINC1. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

PP2B and PP1α cooperatively disrupt 7SK snRNP to release P-TEFb for transcription in response to Ca2+ signaling

PubMed Central

Chen, Ruichuan; Liu, Min; Li, Huan; Xue, Yuhua; Ramey, Wanichaya N.; He, Nanhai; Ai, Nanping; Luo, Haohong; Zhu, Ying; Zhou, Nan; Zhou, Qiang

2008-01-01

The positive transcription elongation factor b (P-TEFb), consisting of Cdk9 and cyclin T, stimulates RNA polymerase II elongation and cotranscriptional pre-mRNA processing. To accommodate different growth conditions and transcriptional demands, a reservoir of P-TEFb is kept in an inactive state in the multisubunit 7SK snRNP. Under certain stress or disease conditions, P-TEFb is released to activate transcription, although the signaling pathway(s) that controls this is largely unknown. Here, through analyzing the UV- or hexamethylene bisacetamide (HMBA)-induced release of P-TEFb from 7SK snRNP, an essential role for the calcium ion (Ca2+)–calmodulin–protein phosphatase 2B (PP2B) signaling pathway is revealed. However, Ca2+ signaling alone is insufficient, and PP2B must act sequentially and cooperatively with protein phosphatase 1α (PP1α) to disrupt 7SK snRNP. Activated by UV/HMBA and facilitated by a PP2B-induced conformational change in 7SK snRNP, PP1α releases P-TEFb through dephosphorylating phospho-Thr186 in the Cdk9 T-loop. This event is also necessary for the subsequent recruitment of P-TEFb by the bromodomain protein Brd4 to the preinitiation complex, where Cdk9 remains unphosphorylated and inactive until after the synthesis of a short RNA. Thus, through cooperatively dephosphorylating Cdk9 in response to Ca2+ signaling, PP2B and PP1α alter the P-TEFb functional equilibrium through releasing P-TEFb from 7SK snRNP for transcription. PMID:18483222

Singlet oxygen generation during the oxidation of L-tyrosine and L-dopa with mushroom tyrosinase.

PubMed

Miyaji, Akimitsu; Kohno, Masahiro; Inoue, Yoshihiro; Baba, Toshihide

2016-03-18

The generation of singlet oxygen during the oxidation of tyrosine and L-dopa using mushroom tyrosinase in a phosphate buffer (pH 7.4), the model of melanin synthesis in melanocytes, was examined. The reaction was performed in the presence of 2,2,6,6-tetramethyl-4-piperidone (4-oxo-TEMP), an acceptor of singlet oxygen and the electron spin resonance (ESR) of the spin adduct, 4-oxo-2,2,6,6-tetramethyl-1-piperidinyloxy (4-oxo-TEMPO), was measured. An increase in the ESR signal attributable to 4-oxo-TEMPO was observed during the oxidation of tyrosine and L-dopa with tyrosinase, indicating the generation of singlet oxygen. The results suggest that (1)O2 generation via tyrosinase-catalyzed melanin synthesis occurs in melanocyte. Copyright © 2016 Elsevier Inc. All rights reserved.

Deleterious ABCA7 mutations and transcript rescue mechanisms in early onset Alzheimer's disease.

PubMed

De Roeck, Arne; Van den Bossche, Tobi; van der Zee, Julie; Verheijen, Jan; De Coster, Wouter; Van Dongen, Jasper; Dillen, Lubina; Baradaran-Heravi, Yalda; Heeman, Bavo; Sanchez-Valle, Raquel; Lladó, Albert; Nacmias, Benedetta; Sorbi, Sandro; Gelpi, Ellen; Grau-Rivera, Oriol; Gómez-Tortosa, Estrella; Pastor, Pau; Ortega-Cubero, Sara; Pastor, Maria A; Graff, Caroline; Thonberg, Håkan; Benussi, Luisa; Ghidoni, Roberta; Binetti, Giuliano; de Mendonça, Alexandre; Martins, Madalena; Borroni, Barbara; Padovani, Alessandro; Almeida, Maria Rosário; Santana, Isabel; Diehl-Schmid, Janine; Alexopoulos, Panagiotis; Clarimon, Jordi; Lleó, Alberto; Fortea, Juan; Tsolaki, Magda; Koutroumani, Maria; Matěj, Radoslav; Rohan, Zdenek; De Deyn, Peter; Engelborghs, Sebastiaan; Cras, Patrick; Van Broeckhoven, Christine; Sleegers, Kristel

2017-09-01

Premature termination codon (PTC) mutations in the ATP-Binding Cassette, Sub-Family A, Member 7 gene (ABCA7) have recently been identified as intermediate-to-high penetrant risk factor for late-onset Alzheimer's disease (LOAD). High variability, however, is observed in downstream ABCA7 mRNA and protein expression, disease penetrance, and onset age, indicative of unknown modifying factors. Here, we investigated the prevalence and disease penetrance of ABCA7 PTC mutations in a large early onset AD (EOAD)-control cohort, and examined the effect on transcript level with comprehensive third-generation long-read sequencing. We characterized the ABCA7 coding sequence with next-generation sequencing in 928 EOAD patients and 980 matched control individuals. With MetaSKAT rare variant association analysis, we observed a fivefold enrichment (p = 0.0004) of PTC mutations in EOAD patients (3%) versus controls (0.6%). Ten novel PTC mutations were only observed in patients, and PTC mutation carriers in general had an increased familial AD load. In addition, we observed nominal risk reducing trends for three common coding variants. Seven PTC mutations were further analyzed using targeted long-read cDNA sequencing on an Oxford Nanopore MinION platform. PTC-containing transcripts for each investigated PTC mutation were observed at varying proportion (5-41% of the total read count), implying incomplete nonsense-mediated mRNA decay (NMD). Furthermore, we distinguished and phased several previously unknown alternative splicing events (up to 30% of transcripts). In conjunction with PTC mutations, several of these novel ABCA7 isoforms have the potential to rescue deleterious PTC effects. In conclusion, ABCA7 PTC mutations play a substantial role in EOAD, warranting genetic screening of ABCA7 in genetically unexplained patients. Long-read cDNA sequencing revealed both varying degrees of NMD and transcript-modifying events, which may influence ABCA7 dosage, disease severity, and may

Glycogen synthase kinase 3 beta inhibits microRNA-183-96-182 cluster via the β-Catenin/TCF/LEF-1 pathway in gastric cancer cells.

PubMed

Tang, Xiaoli; Zheng, Dong; Hu, Ping; Zeng, Zongyue; Li, Ming; Tucker, Lynne; Monahan, Renee; Resnick, Murray B; Liu, Manran; Ramratnam, Bharat

2014-03-01

Glycogen synthase kinase 3 beta (GSK3β) is a critical protein kinase that phosphorylates numerous proteins in cells and thereby impacts multiple pathways including the β-Catenin/TCF/LEF-1 pathway. MicroRNAs (miRs) are a class of noncoding small RNAs of ∼22 nucleotides in length. Both GSK3β and miR play myriad roles in cell functions including stem cell development, apoptosis, embryogenesis and tumorigenesis. Here we show that GSK3β inhibits the expression of miR-96, miR-182 and miR-183 through the β-Catenin/TCF/LEF-1 pathway. Knockout of GSK3β in mouse embryonic fibroblast cells increases expression of miR-96, miR-182 and miR-183, coinciding with increases in the protein level and nuclear translocation of β-Catenin. In addition, overexpression of β-Catenin enhances the expression of miR-96, miR-182 and miR-183 in human gastric cancer AGS cells. GSK3β protein levels are decreased in human gastric cancer tissue compared with surrounding normal gastric tissue, coinciding with increases of β-Catenin protein, miR-96, miR-182, miR-183 and primary miR-183-96-182 cluster (pri-miR-183). Furthermore, suppression of miR-183-96-182 cluster with miRCURY LNA miR inhibitors decreases the proliferation and migration of AGS cells. Knockdown of GSK3β with siRNA increases the proliferation of AGS cells. Mechanistically, we show that β-Catenin/TCF/LEF-1 binds to the promoter of miR-183-96-182 cluster gene and thereby activates the transcription of the cluster. In summary, our findings identify a novel role for GSK3β in the regulation of miR-183-96-182 biogenesis through β-Catenin/TCF/LEF-1 pathway in gastric cancer cells.

PKCζ and PKMζ are overexpressed in TCF3-rearranged paediatric acute lymphoblastic leukaemia and are associated with increased thiopurine sensitivity.

PubMed

Hartsink-Segers, S A; Beaudoin, J J; Luijendijk, M W J; Exalto, C; Pieters, R; Den Boer, M L

2015-02-01

Both tumour suppressor and oncogenic functions have been ascribed to the atypical zeta isoform of protein kinase C (PKCζ), whereas its constitutively active form PKMζ is almost exclusively expressed in the brain where it has a role in long-term memory. Using primers unique for either isoform, we found that both PKCζ and PKMζ were expressed in a subset of paediatric acute lymphoblastic leukaemia (ALL) cases carrying a TCF3 (E2A) chromosomal rearrangement. Combined PKCζ and PKMζ (PKC/Mζ) protein as well as phosphorylation levels were elevated in ALL cases, especially TCF3-rearranged precursor B-ALL cases, compared with normal bone marrow (P<0.01). Furthermore, high PKC/Mζ expression in primary ALL cells was associated with increased sensitivity to 6-thioguanine and 6-mercaptopurine (P<0.01), thiopurines used in ALL treatment. PKCζ is believed to stabilize mismatch-repair protein MSH2, facilitating thiopurine responsiveness in T-ALL. However, PKC/Mζ knockdown in a TCF3-rearranged cell line model decreased MSH2 expression but did not induce thiopurine resistance, indicative that the link between high PKC/Mζ levels and thiopurine sensitivity in paediatric precursor B-ALL is not directly causal. Collectively, our data indicate that thiopurine treatment may be effective, especially in paediatric TCF3-rearranged ALL and other patients with a high expression of PKC/Mζ.

PKCζ and PKMζ are overexpressed in TCF3-rearranged paediatric acute lymphoblastic leukaemia and are associated with increased thiopurine sensitivity

PubMed Central

Hartsink-Segers, S A; Beaudoin, J J; Luijendijk, M W J; Exalto, C; Pieters, R; Den Boer, M L

2015-01-01

Both tumour suppressor and oncogenic functions have been ascribed to the atypical zeta isoform of protein kinase C (PKCζ), whereas its constitutively active form PKMζ is almost exclusively expressed in the brain where it has a role in long-term memory. Using primers unique for either isoform, we found that both PKCζ and PKMζ were expressed in a subset of paediatric acute lymphoblastic leukaemia (ALL) cases carrying a TCF3 (E2A) chromosomal rearrangement. Combined PKCζ and PKMζ (PKC/Mζ) protein as well as phosphorylation levels were elevated in ALL cases, especially TCF3-rearranged precursor B-ALL cases, compared with normal bone marrow (P<0.01). Furthermore, high PKC/Mζ expression in primary ALL cells was associated with increased sensitivity to 6-thioguanine and 6-mercaptopurine (P<0.01), thiopurines used in ALL treatment. PKCζ is believed to stabilize mismatch-repair protein MSH2, facilitating thiopurine responsiveness in T-ALL. However, PKC/Mζ knockdown in a TCF3-rearranged cell line model decreased MSH2 expression but did not induce thiopurine resistance, indicative that the link between high PKC/Mζ levels and thiopurine sensitivity in paediatric precursor B-ALL is not directly causal. Collectively, our data indicate that thiopurine treatment may be effective, especially in paediatric TCF3-rearranged ALL and other patients with a high expression of PKC/Mζ. PMID:24990612

Transcriptional Profiling of Human Endogenous Retrovirus Group HERV-K(HML-2) Loci in Melanoma

PubMed Central

Schmitt, Katja; Reichrath, Jörg; Roesch, Alexander; Meese, Eckart; Mayer, Jens

2013-01-01

Recent studies suggested a role for the human endogenous retrovirus (HERV) group HERV-K(HML-2) in melanoma because of upregulated transcription and expression of HERV-K(HML-2)-encoded proteins. Very little is known about which HML-2 loci are transcribed in melanoma. We assigned >1,400 HML-2 cDNA sequences generated from various melanoma and related samples to genomic HML-2 loci, identifying a total of 23 loci as transcribed. Transcription profiles of loci differed significantly between samples. One locus was found transcribed only in melanoma-derived samples but not in melanocytes and might represent a marker for melanoma. Several of the transcribed loci harbor ORFs for retroviral Gag and/or Env proteins. Env-encoding loci were transcribed only in melanoma. Specific investigation of rec and np9 transcripts indicated transcription of protein encoding loci in melanoma and melanocytes hinting at the relevance of Rec and Np9 in melanoma. UVB irradiation changed transcription profiles of loci and overall transcript levels decreased in melanoma and melanocytes. We further identified transcribed HML-2 loci formed by reverse transcription of spliced HML-2 transcripts by L1 machinery or in a retroviral fashion, with loci potentially encoding HML-2-like proteins. We reveal complex, sample-specific transcription of HML-2 loci in melanoma and related samples. Identified HML-2 loci and proteins encoded by those loci are particularly relevant for further studying the role of HML-2 in melanoma. Transcription of HERVs appears as a complex mechanism requiring specific studies to elucidate which HERV loci are transcribed and how transcribed HERVs may be involved in disease. PMID:23338945

7SK-BAF axis controls pervasive transcription at enhancers

PubMed Central

Flynn, Ryan A.; Do, Brian T.; Rubin, Adam J.; Calo, Eliezer; Lee, Byron; Kuchelmeister, Hannes; Rale, Michael; Chu, Ci; Kool, Eric T.; Wysocka, Joanna; Khavari, Paul A.

2016-01-01

RNA functions at enhancers remain mysterious. Here we show that the 7SK small nuclear RNA (snRNA) inhibits enhancer transcription by modulating nucleosome position. 7SK occupies enhancers and super enhancers genome-wide in mouse and human cells, and 7SK is required to limit eRNA initiation and synthesis in a manner distinct from promoter pausing. Clustered elements at super enhancers uniquely require 7SK to prevent convergent transcription and DNA damage signaling. 7SK physically interacts with the BAF chromatin remodeling complex, recruit BAF to enhancers, and inhibits enhancer transcription by modulating chromatin structure. In turn, 7SK occupancy at enhancers coincides with Brd4 and is exquisitely sensitive to the bromodomain inhibitor JQ1. Thus, 7SK employs distinct mechanisms to counteract diverse consequences of pervasive transcription that distinguish super enhancers, enhancers, and promoters. PMID:26878240

Comparison of voice-automated transcription and human transcription in generating pathology reports.

PubMed

Al-Aynati, Maamoun M; Chorneyko, Katherine A

2003-06-01

Software that can convert spoken words into written text has been available since the early 1980s. Early continuous speech systems were developed in 1994, with the latest commercially available editions having a claimed accuracy of up to 98% of speech recognition at natural speech rates. To evaluate the efficacy of one commercially available voice-recognition software system with pathology vocabulary in generating pathology reports and to compare this with human transcription. To draw cost analysis conclusions regarding human versus computer-based transcription. Two hundred six routine pathology reports from the surgical pathology material handled at St Joseph's Healthcare, Hamilton, Ontario, were generated simultaneously using computer-based transcription and human transcription. The following hardware and software were used: a desktop 450-MHz Intel Pentium III processor with 192 MB of RAM, a speech-quality sound card (Sound Blaster), noise-canceling headset microphone, and IBM ViaVoice Pro version 8 with pathology vocabulary support (Voice Automated, Huntington Beach, Calif). The cost of the hardware and software used was approximately Can 2250 dollars. A total of 23 458 words were transcribed using both methods with a mean of 114 words per report. The mean accuracy rate was 93.6% (range, 87.4%-96%) using the computer software, compared to a mean accuracy of 99.6% (range, 99.4%-99.8%) for human transcription (P <.001). Time needed to edit documents by the primary evaluator (M.A.) using the computer was on average twice that needed for editing the documents produced by human transcriptionists (range, 1.4-3.5 times). The extra time needed to edit documents was 67 minutes per week (13 minutes per day). Computer-based continuous speech-recognition systems in pathology can be successfully used in pathology practice even during the handling of gross pathology specimens. The relatively low accuracy rate of this voice-recognition software with resultant increased editing

[Effects of Biejiajian Pills on Wnt signal pathway signal molecules β-catenin/TCF4 complex activities and downstream proteins cyclin D1 and MMP-2 in hepatocellular carcinoma cells].

PubMed

Wen, Bin; Sun, Haitao; He, Songqi; Cheng, Yang; Jia, Wenyan; Fan, Eryan; Pang, Jie

2014-12-01

To study the effect of Biejiajian Pills on Wnt signal pathway and the mechanisms underlying its action to suppress the invasiveness of hepatocellular carcinoma. HepG2 cells cultured in the serum of rats fed with Biejiajian Pills for 48 h were examined for β-catenin expression using immunofluorescence, β-catenin/TCF4 complex activity with luciferase, and expressions of the downstream proteins cyclin D1 and MMP-2 using qRT-PCR. Biejiajian Pills-treated sera significantly reduced the expressions of cytoplasmic and nuclear β-catenin protein, cyclin D1 and MMP-2 proteins and lowered the activities of β-catenin/TCF4 complex. Biejiajian Pills may serve as a potential anti-tumor agent, whose effect might be mediated by inhibiting the Wnt/β-catenin pathway.

Neurotensin receptor 1 gene activation by the Tcf/beta-catenin pathway is an early event in human colonic adenomas.

PubMed

Souazé, Frédérique; Viardot-Foucault, Véronique; Roullet, Nicolas; Toy-Miou-Leong, Mireille; Gompel, Anne; Bruyneel, Erik; Comperat, Eva; Faux, Maree C; Mareel, Marc; Rostène, William; Fléjou, Jean-François; Gespach, Christian; Forgez, Patricia

2006-04-01

Alterations in the Wnt/APC (adenomatous polyposis coli) signalling pathway, resulting in beta-catenin/T cell factor (Tcf)-dependent transcriptional gene activation, are frequently detected in familial and sporadic colon cancers. The neuropeptide neurotensin (NT) is widely distributed in the gastrointestinal tract. Its proliferative and survival effects are mediated by a G-protein coupled receptor, the NT1 receptor. NT1 receptor is not expressed in normal colon epithelial cells, but is over expressed in a number of cancer cells and tissues suggesting a link to the outgrowth of human colon cancer. Our results demonstrate that the upregulation of NT1 receptor occurring in colon cancer is the result of Wnt/APC signalling pathway activation. We first established the functionality of the Tcf response element within the NT1 receptor promoter. Consequently, we observed the activation of NT1 receptor gene by agents causing beta-catenin cytosolic accumulation, as well as a strong decline of endogenous receptor when wt-APC was restored. At the cellular level, the re-establishment of wt-APC phenotype resulted in the impaired functionality of NT1 receptor, like the breakdown in NT-induced intracellular calcium mobilization and the loss of NT pro-invasive effect. We corroborated the Wnt/APC signalling pathway on the NT1 receptor promoter activation with human colon carcinogenesis, and showed that NT1 receptor gene activation was perfectly correlated with nuclear or cytoplasmic beta-catenin localization while NT1 receptor was absent when beta-catenin was localized at the cell-cell junction in early adenomas of patients with familial adenomatous polyposis, hereditary non-polyposis colorectal cancer and loss of heterozygosity tumours. In this report we establish a novel link in vitro between the Tcf/beta-catenin pathway and NT1 receptor promoter activation.

Activation of the Wnt/β-catenin pathway in pancreatic beta cells during the compensatory islet hyperplasia in prediabetic mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maschio, D. A.; Oliveira, R. B.; Santos, M. R.

The Wnt/β-catenin signaling pathway, also known as the canonical Wnt pathway, plays a role in cell proliferation and differentiation in several tissues/organs. It has been recently described in humans a relationship between type 2 diabetes (T2DM) and mutation in the gene encoding the transcription factor TCF7L2 associated to the Wnt/β-catenin pathway. In the present study, we demonstrated that hyperplastic pancreatic islets from prediabetic mice fed a high-fat diet (HFD) for 60 d displayed nuclear translocation of active β-catenin associated with significant increases in protein content and gene expression of β-catenin as well as of cyclins D1, D2 and c-Myc (target genesmore » of the Wnt pathway) but not of Tcf7l2 (the transcription factor). Meanwhile, these alterations were not observed in pancreatic islets from 30 d HFD-fed mice, that do not display significant beta cell hyperplasia. These data suggest that the Wnt/β-catenin pathway is activated in pancreatic islets during prediabetes and may play a role in the induction of the compensatory beta cell hyperplasia observed at early phase of T2DM. - Highlights: • Exposure to high-fat diet for 60 days induced prediabetes and beta cell mass expansion. • Hyperplastic pancreatic islets displayed nuclear translocation of active β-catenin. • Hyperplastic islets showed increased expression of target genes of the Wnt/β-catenin pathway. • Wnt/β-catenin pathway is activated during compensatory beta cell hyperplasia in mice.« less

Singlet oxygen generation during the oxidation of L-tyrosine and L-dopa with mushroom tyrosinase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miyaji, Akimitsu; Kohno, Masahiro; Inoue, Yoshihiro

2016-03-18

The generation of singlet oxygen during the oxidation of tyrosine and L-dopa using mushroom tyrosinase in a phosphate buffer (pH 7.4), the model of melanin synthesis in melanocytes, was examined. The reaction was performed in the presence of 2,2,6,6-tetramethyl-4-piperidone (4-oxo-TEMP), an acceptor of singlet oxygen and the electron spin resonance (ESR) of the spin adduct, 4-oxo-2,2,6,6-tetramethyl-1-piperidinyloxy (4-oxo-TEMPO), was measured. An increase in the ESR signal attributable to 4-oxo-TEMPO was observed during the oxidation of tyrosine and L-dopa with tyrosinase, indicating the generation of singlet oxygen. The results suggest that {sup 1}O{sub 2} generation via tyrosinase-catalyzed melanin synthesis occurs in melanocyte.more » - Highlights: • Generation of singlet oxygen was observed during tyrosinase-catalyzed tyrosine oxidation. • The singlet oxygen generated when tyrosine was converted into dopachrome. • The amount of singlet oxygen is not sufficient for cell toxicity. • It decreased when the hydroxyl radicals and/or superoxide anions were trapped.« less

Several genes encoding ribosomal proteins are over-expressed in prostate-cancer cell lines: confirmation of L7a and L37 over-expression in prostate-cancer tissue samples.

PubMed

Vaarala, M H; Porvari, K S; Kyllönen, A P; Mustonen, M V; Lukkarinen, O; Vihko, P T

1998-09-25

A cDNA library specific for mRNA over-expressed in prostate cancer was generated by subtractive hybridization of transcripts originating from prostatic hyperplasia and cancer tissues. cDNA encoding ribosomal proteins L4, L5, L7a, L23a, L30, L37, S14 and S18 was found to be present among 100 analyzed clones. Levels of ribosomal mRNA were significantly higher at least in one of the prostate-cancer cell lines, LNCaP, DU-145 and PC-3, than in hyperplastic tissue, as determined by slot-blot hybridization. Furthermore, L23a- and S14-transcript levels were significantly elevated in PC-3 cells as compared with those in the normal prostate epithelial cell line PrEC. Generally, dramatic changes in the mRNA content of the ribosomal proteins were not detected, the most evident over-expression being that of L37 mRNA, which was 3.4 times more abundant in LNCaP cells than in hyperplastic prostate tissue. The over-expression of L7a and L37 mRNA was confirmed in prostate-cancer tissue samples by in situ hybridization. Elevated cancer-related expression of L4 and L30 has not been reported, but levels of the other ribosomal proteins are known to be increased in several types of cancers. These results therefore suggest that prostate cancer is comparable with other types of cancers, in that a larger pool of some ribosomal proteins is gained during the transformation process, by an unknown mechanism.

Knockdown of the schizophrenia susceptibility gene TCF4 alters gene expression and proliferation of progenitor cells from the developing human neocortex.

PubMed

Hill, Matthew J; Killick, Richard; Navarrete, Katherinne; Maruszak, Aleksandra; McLaughlin, Gemma M; Williams, Brenda P; Bray, Nicholas J

2017-05-01

Common variants in the TCF4 gene are among the most robustly supported genetic risk factors for schizophrenia. Rare TCF4 deletions and loss-of-function point mutations cause Pitt-Hopkins syndrome, a developmental disorder associated with severe intellectual disability. To explore molecular and cellular mechanisms by which TCF4 perturbation could interfere with human cortical development, we experimentally reduced the endogenous expression of TCF4 in a neural progenitor cell line derived from the developing human cerebral cortex using RNA interference. Effects on genome-wide gene expression were assessed by microarray, followed by Gene Ontology and pathway analysis of differentially expressed genes. We tested for genetic association between the set of differentially expressed genes and schizophrenia using genome-wide association study data from the Psychiatric Genomics Consortium and competitive gene set analysis (MAGMA). Effects on cell proliferation were assessed using high content imaging. Genes that were differentially expressed following TCF4 knockdown were highly enriched for involvement in the cell cycle. There was a nonsignificant trend for genetic association between the differentially expressed gene set and schizophrenia. Consistent with the gene expression data, TCF4 knockdown was associated with reduced proliferation of cortical progenitor cells in vitro. A detailed mechanistic explanation of how TCF4 knockdown alters human neural progenitor cell proliferation is not provided by this study. Our data indicate effects of TCF4 perturbation on human cortical progenitor cell proliferation, a process that could contribute to cognitive deficits in individuals with Pitt-Hopkins syndrome and risk for schizophrenia.

Butyrate-induced apoptotic cascade in colonic carcinoma cells: modulation of the beta-catenin-Tcf pathway and concordance with effects of sulindac and trichostatin A but not curcumin.

PubMed

Bordonaro, M; Mariadason, J M; Aslam, F; Heerdt, B G; Augenlicht, L H

1999-10-01

Short-chain fatty acids play a critical role in colonic homeostasis because they stimulate pathways of growth arrest, differentiation, and apoptosis. These effects have been well characterized in colonic cell lines in vitro. We investigated the role of beta-catenin-Tcf signaling in these responses to butyrate and other well-characterized inducers of apoptosis of colonic epithelial cells. Unlike wild-type APC, which down-regulates Tcf activity, butyrate, as well as sulindac and trichostatin A, all inducers of G0-G1 cell cycle arrest and apoptosis in the SW620 colonic carcinoma cell line, up-regulate Tcf activity. In contrast, structural analogues of butyrate that do not induce cell cycle arrest or apoptosis and curcumin, which stimulates G2-M arrest without inducing apoptosis, do not alter Tcf activity. Similar to the cell cycle arrest and apoptotic cascade induced by butyrate, the up-regulation of Tcf activity is dependent upon the presence of a mitochondrial membrane potential, unlike the APC-induced down-regulation, which is insensitive to collapse of the mitochondrial membrane potential. Moreover, the butyrate-induced increase in Tcf activity, which is reflected in an increase in beta-catenin-Tcf complex formation, is independent of the down-regulation caused by expression of wild-type APC. Thus, butyrate and wild-type APC have different and independent effects on beta-catenin-Tcf signaling. These data are consistent with other reports that suggest that the absence of wild-type APC, associated with the up-regulation of this signaling pathway, is linked to the probability of a colonic epithelial cell entering an apoptotic cascade.

Stage-specific control of connective tissue growth factor (CTGF/CCN2) expression in chondrocytes by Sox9 and beta-catenin.

PubMed

Huang, Bau-Lin; Brugger, Sean M; Lyons, Karen M

2010-09-03

CCN2/connective tissue growth factor is highly expressed in hypertrophic chondrocytes and is required for chondrogenesis. However, the transcriptional mechanisms controlling its expression in cartilage are largely unknown. The activity of the Ccn2 promoter was, therefore, investigated in osteochondro-progenitor cells and hypertrophic chondrocytes to ascertain these mechanisms. Sox9 and T-cell factor (TCF) x lymphoid enhancer factor (LEF) factors contain HMG domains and bind to related consensus sites. TCF x LEF factors are normally repressive but when bound to DNA in a complex with beta-catenin become activators of gene expression. In silico analysis of the Ccn2 proximal promoter identified multiple consensus TCF x LEF elements, one of which was also a consensus binding site for Sox9. Using luciferase reporter constructs, the TCF x LEF x Sox9 site was found to be involved in stage-specific expression of Ccn2. Luciferase, electrophoretic mobility shift assay (EMSA), and ChIP analysis revealed that Sox9 represses Ccn2 expression by binding to the consensus TCF x LEF x Sox9 site. On the other hand, the same assays showed that in hypertrophic chondrocytes, TCF x LEF x beta-catenin complexes occupy the consensus TCF x LEF x Sox9 site and activate Ccn2 expression. Furthermore, transgenic mice in which lacZ expression is driven under the control of the proximal Ccn2 promoter revealed that the proximal Ccn2 promoter responded to Wnt signaling in cartilage. Hence, we propose that differential occupancy of the TCF x LEF x Sox9 site by Sox9 versus beta-catenin restricts high levels of Ccn2 expression to hypertrophic chondrocytes.

Transcriptional regulation of intermediate progenitor cell generation during hippocampal development

PubMed Central

Harris, Lachlan; Zalucki, Oressia; Gobius, Ilan; McDonald, Hannah; Osinki, Jason; Harvey, Tracey J.; Essebier, Alexandra; Vidovic, Diana; Gladwyn-Ng, Ivan; Burne, Thomas H.; Heng, Julian I.; Richards, Linda J.; Gronostajski, Richard M.

2016-01-01

During forebrain development, radial glia generate neurons through the production of intermediate progenitor cells (IPCs). The production of IPCs is a central tenet underlying the generation of the appropriate number of cortical neurons, but the transcriptional logic underpinning this process remains poorly defined. Here, we examined IPC production using mice lacking the transcription factor nuclear factor I/X (Nfix). We show that Nfix deficiency delays IPC production and prolongs the neurogenic window, resulting in an increased number of neurons in the postnatal forebrain. Loss of additional Nfi alleles (Nfib) resulted in a severe delay in IPC generation while, conversely, overexpression of NFIX led to precocious IPC generation. Mechanistically, analyses of microarray and ChIP-seq datasets, coupled with the investigation of spindle orientation during radial glial cell division, revealed that NFIX promotes the generation of IPCs via the transcriptional upregulation of inscuteable (Insc). These data thereby provide novel insights into the mechanisms controlling the timely transition of radial glia into IPCs during forebrain development. PMID:27965439

Discovery of novel transcripts of the human tissue kallikrein (KLK1) and kallikrein-related peptidase 2 (KLK2) in human cancer cells, exploiting Next-Generation Sequencing technology.

PubMed

Adamopoulos, Panagiotis G; Kontos, Christos K; Scorilas, Andreas

2018-03-31

Tissue kallikrein, kallikrein-related peptidases (KLKs), and plasma kallikrein form the largest group of serine proteases in the human genome, sharing many structural and functional properties. Several KLK transcripts have been found aberrantly expressed in numerous human malignancies, confirming their prognostic or/and diagnostic values. However, the process of alternative splicing can now be studied in-depth due to the development of Next-Generation Sequencing (NGS). In the present study, we used NGS to discover novel transcripts of the KLK1 and KLK2 genes, after nested touchdown PCR. Bioinformatics analysis and PCR experiments revealed a total of eleven novel KLK transcripts (two KLK1 and nine KLK2 transcripts). In addition, the expression profiles of each novel transcript were investigated with nested PCR experiments using variant-specific primers. Since KLKs are implicated in human malignancies, qualifying as potential biomarkers, the quantification of the presented novel transcripts in human samples may have clinical applications in different types of cancer. Copyright © 2018. Published by Elsevier Inc.

Strategic Processing and Predictive Inference Generation in L2 Reading

ERIC Educational Resources Information Center

Nahatame, Shingo

2014-01-01

Predictive inference is the anticipation of the likely consequences of events described in a text. This study investigated predictive inference generation during second language (L2) reading, with a focus on the effects of strategy instructions. In this experiment, Japanese university students read several short narrative passages designed to…

Lactobacillus herbarum sp. nov., a species related to Lactobacillus plantarum.

PubMed

Mao, Yuejian; Chen, Meng; Horvath, Philippe

2015-12-01

Strain TCF032-E4 was isolated from a traditional Chinese fermented radish. It shares >99% 16S rRNA sequence identity with L. plantarum, L. pentosus and L. paraplantarum. This strain can ferment ribose, galactose, glucose, fructose, mannose, mannitol, N-acetylglucosamine, amygdalin, arbutin, salicin, cellobiose, maltose, lactose, melibiose, trehalose and gentiobiose. It cannot ferment sucrose, which can be used by L. pentosus, L. paraplantarum, L. fabifermentans, L. xiangfangensis and L. mudanjiangensis, as well as most of the L. plantarum strains (88.7%). TCF032-E4 cannot grow at temperature above 32 °C. This strain shares 78.2-83.6% pheS (phenylalanyl-tRNA synthetase alpha subunit) and 89.5-94.9% rpoA (RNA polymerase alpha subunit) sequence identity with L. plantarum, L. pentosus, L. paraplantarum, L. fabifermentans, L. xiangfangensis and L. mudanjiangensis. These results indicate that TCF032-E4 represents a distinct species. This hypothesis was further confirmed by whole-genome sequencing and comparison with available genomes of related species. The draft genome size of TCF032-E4 is approximately 2.9 Mb, with a DNA G+C content of 43.5 mol%. The average nucleotide identity (ANI) between TCF032-E4 and related species ranges from 79.0 to 81.1%, the highest ANI value being observed with L. plantarum subsp. plantarum ATCC 14917T. A novel species, Lactobacillus herbarum sp. nov., is proposed with TCF032-E4T ( = CCTCC AB2015090T = DSM 100358T) as the type strain.

Defining Transcriptional Regulatory Mechanisms for Primary let-7 miRNAs

PubMed Central

Gaeta, Xavier; Le, Luat; Lin, Ying; Xie, Yuan; Lowry, William E.

2017-01-01

The let-7 family of miRNAs have been shown to control developmental timing in organisms from C. elegans to humans; their function in several essential cell processes throughout development is also well conserved. Numerous studies have defined several steps of post-transcriptional regulation of let-7 production; from pri-miRNA through pre-miRNA, to the mature miRNA that targets endogenous mRNAs for degradation or translational inhibition. Less-well defined are modes of transcriptional regulation of the pri-miRNAs for let-7. let-7 pri-miRNAs are expressed in polycistronic fashion, in long transcripts newly annotated based on chromatin-associated RNA-sequencing. Upon differentiation, we found that some let-7 pri-miRNAs are regulated at the transcriptional level, while others appear to be constitutively transcribed. Using the Epigenetic Roadmap database, we further annotated regulatory elements of each polycistron identified putative promoters and enhancers. Probing these regulatory elements for transcription factor binding sites identified factors that regulate transcription of let-7 in both promoter and enhancer regions, and identified novel regulatory mechanisms for this important class of miRNAs. PMID:28052101

Targeting the upstream transcriptional activator of PD-L1 as an alternative strategy in melanoma therapy.

PubMed

Zhu, Bo; Tang, Liming; Chen, Shuyang; Yin, Chengqian; Peng, Shiguang; Li, Xin; Liu, Tongzheng; Liu, Wei; Han, Changpeng; Stawski, Lukasz; Xu, Zhi-Xiang; Zhou, Guangbiao; Chen, Xiang; Gao, Xiumei; Goding, Colin R; Xu, Nan; Cui, Rutao; Cao, Peng

2018-05-22

Programmed cell death ligand 1 (PD-L1) interacts with programmed cell death protein-1 (PD-1) as an immune checkpoint. Reactivating the immune response by inhibiting PD-L1 using therapeutic antibodies provides substantial clinical benefits in many, though not all, melanoma patients. However, transcriptional suppression of PD-L1 expression as an alternative therapeutic anti-melanoma strategy has not been exploited. Here we provide biochemical evidence demonstrating that ultraviolet radiation (UVR) induction of PD-L1 in skin is directly controlled by nuclear factor E2-related transcription factor 2 (NRF2). Depletion of NRF2 significantly induces tumor infiltration by both CD8 + and CD4 + T cells to suppress melanoma progression, and combining NRF2 inhibition with anti-PD-1 treatment enhanced its anti-tumor function. Our studies identify a critical and targetable PD-L1 upstream regulator and provide an alternative strategy to inhibit the PD-1/PD-L1 signaling in melanoma treatment.

A novel corepressor, BCoR-L1, represses transcription through an interaction with CtBP.

PubMed

Pagan, Julia K; Arnold, Jeremy; Hanchard, Kim J; Kumar, Raman; Bruno, Tiziana; Jones, Mathew J K; Richard, Derek J; Forrest, Alistair; Spurdle, Amanda; Verdin, Eric; Crossley, Merlin; Fanciulli, Maurizio; Chenevix-Trench, Georgia; Young, David B; Khanna, Kum Kum

2007-05-18

Corepressors play a crucial role in negative gene regulation and are defective in several diseases. BCoR is a corepressor for the BCL6 repressor protein. Here we describe and functionally characterize BCoR-L1, a homolog of BCoR. When tethered to a heterologous promoter, BCoR-L1 is capable of strong repression. Like other corepressors, BCoR-L1 associates with histone deacetylase (HDAC) activity. Specifically, BCoR-L1 coprecipitates with the Class II HDACs, HDAC4, HDAC5, and HDAC7, suggesting that they are involved in its role as a transcriptional repressor. BCoR-L1 also interacts with the CtBP corepressor through a CtBP-interacting motif in its amino terminus. Abrogation of the CtBP binding site within BCoR-L1 partially relieves BCoR-L1-mediated transcriptional repression. Furthermore, BCoR-L1 is located on the E-cadherin promoter, a known CtBP-regulated promoter, and represses the E-cadherin promoter activity in a reporter assay. The inhibition of BCoR-L1 expression by RNA-mediated interference results in derepression of E-cadherin in cells that do not normally express E-cadherin, indicating that BCoR-L1 contributes to the repression of an authentic endogenous CtBP target.

Transcriptional consequences of 16p11.2 deletion and duplication in mouse cortex and multiplex autism families.

PubMed

Blumenthal, Ian; Ragavendran, Ashok; Erdin, Serkan; Klei, Lambertus; Sugathan, Aarathi; Guide, Jolene R; Manavalan, Poornima; Zhou, Julian Q; Wheeler, Vanessa C; Levin, Joshua Z; Ernst, Carl; Roeder, Kathryn; Devlin, Bernie; Gusella, James F; Talkowski, Michael E

2014-06-05

Reciprocal copy-number variation (CNV) of a 593 kb region of 16p11.2 is a common genetic cause of autism spectrum disorder (ASD), yet it is not completely penetrant and can manifest in a wide array of phenotypes. To explore its molecular consequences, we performed RNA sequencing of cerebral cortex from mouse models with CNV of the syntenic 7qF3 region and lymphoblast lines from 34 members of 7 multiplex ASD-affected families harboring the 16p11.2 CNV. Expression of all genes in the CNV region correlated well with their DNA copy number, with no evidence of dosage compensation. We observed effects on gene expression outside the CNV region, including apparent positional effects in cis and in trans at genomic segments with evidence of physical interaction in Hi-C chromosome conformation data. One of the most significant positional effects was telomeric to the 16p11.2 CNV and includes the previously described "distal" 16p11.2 microdeletion. Overall, 16p11.2 CNV was associated with altered expression of genes and networks that converge on multiple hypotheses of ASD pathogenesis, including synaptic function (e.g., NRXN1, NRXN3), chromatin modification (e.g., CHD8, EHMT1, MECP2), transcriptional regulation (e.g., TCF4, SATB2), and intellectual disability (e.g., FMR1, CEP290). However, there were differences between tissues and species, with the strongest effects being consistently within the CNV region itself. Our analyses suggest that through a combination of indirect regulatory effects and direct effects on nuclear architecture, alteration of 16p11.2 genes disrupts expression networks that involve other genes and pathways known to contribute to ASD, suggesting an overlap in mechanisms of pathogenesis. Copyright © 2014 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Transcriptional Consequences of 16p11.2 Deletion and Duplication in Mouse Cortex and Multiplex Autism Families

PubMed Central

Blumenthal, Ian; Ragavendran, Ashok; Erdin, Serkan; Klei, Lambertus; Sugathan, Aarathi; Guide, Jolene R.; Manavalan, Poornima; Zhou, Julian Q.; Wheeler, Vanessa C.; Levin, Joshua Z.; Ernst, Carl; Roeder, Kathryn; Devlin, Bernie; Gusella, James F.; Talkowski, Michael E.

2014-01-01

Reciprocal copy-number variation (CNV) of a 593 kb region of 16p11.2 is a common genetic cause of autism spectrum disorder (ASD), yet it is not completely penetrant and can manifest in a wide array of phenotypes. To explore its molecular consequences, we performed RNA sequencing of cerebral cortex from mouse models with CNV of the syntenic 7qF3 region and lymphoblast lines from 34 members of 7 multiplex ASD-affected families harboring the 16p11.2 CNV. Expression of all genes in the CNV region correlated well with their DNA copy number, with no evidence of dosage compensation. We observed effects on gene expression outside the CNV region, including apparent positional effects in cis and in trans at genomic segments with evidence of physical interaction in Hi-C chromosome conformation data. One of the most significant positional effects was telomeric to the 16p11.2 CNV and includes the previously described “distal” 16p11.2 microdeletion. Overall, 16p11.2 CNV was associated with altered expression of genes and networks that converge on multiple hypotheses of ASD pathogenesis, including synaptic function (e.g., NRXN1, NRXN3), chromatin modification (e.g., CHD8, EHMT1, MECP2), transcriptional regulation (e.g., TCF4, SATB2), and intellectual disability (e.g., FMR1, CEP290). However, there were differences between tissues and species, with the strongest effects being consistently within the CNV region itself. Our analyses suggest that through a combination of indirect regulatory effects and direct effects on nuclear architecture, alteration of 16p11.2 genes disrupts expression networks that involve other genes and pathways known to contribute to ASD, suggesting an overlap in mechanisms of pathogenesis. PMID:24906019

Genome-Wide DNA Methylation Analysis of Human Pancreatic Islets from Type 2 Diabetic and Non-Diabetic Donors Identifies Candidate Genes That Influence Insulin Secretion

PubMed Central

Dayeh, Tasnim; Volkov, Petr; Salö, Sofia; Hall, Elin; Nilsson, Emma; Olsson, Anders H.; Kirkpatrick, Clare L.; Wollheim, Claes B.; Eliasson, Lena; Rönn, Tina; Bacos, Karl; Ling, Charlotte

2014-01-01

Impaired insulin secretion is a hallmark of type 2 diabetes (T2D). Epigenetics may affect disease susceptibility. To describe the human methylome in pancreatic islets and determine the epigenetic basis of T2D, we analyzed DNA methylation of 479,927 CpG sites and the transcriptome in pancreatic islets from T2D and non-diabetic donors. We provide a detailed map of the global DNA methylation pattern in human islets, β- and α-cells. Genomic regions close to the transcription start site showed low degrees of methylation and regions further away from the transcription start site such as the gene body, 3′UTR and intergenic regions showed a higher degree of methylation. While CpG islands were hypomethylated, the surrounding 2 kb shores showed an intermediate degree of methylation, whereas regions further away (shelves and open sea) were hypermethylated in human islets, β- and α-cells. We identified 1,649 CpG sites and 853 genes, including TCF7L2, FTO and KCNQ1, with differential DNA methylation in T2D islets after correction for multiple testing. The majority of the differentially methylated CpG sites had an intermediate degree of methylation and were underrepresented in CpG islands (∼7%) and overrepresented in the open sea (∼60%). 102 of the differentially methylated genes, including CDKN1A, PDE7B, SEPT9 and EXOC3L2, were differentially expressed in T2D islets. Methylation of CDKN1A and PDE7B promoters in vitro suppressed their transcriptional activity. Functional analyses demonstrated that identified candidate genes affect pancreatic β- and α-cells as Exoc3l silencing reduced exocytosis and overexpression of Cdkn1a, Pde7b and Sept9 perturbed insulin and glucagon secretion in clonal β- and α-cells, respectively. Together, our data can serve as a reference methylome in human islets. We provide new target genes with altered DNA methylation and expression in human T2D islets that contribute to perturbed insulin and glucagon secretion. These results highlight

Long noncoding RNA AFAP1‑AS1 enhances cell proliferation and invasion in osteosarcoma through regulating miR‑4695‑5p/TCF4‑β‑catenin signaling.

PubMed

Li, Rongrui; Liu, Shichen; Li, Yao; Tang, Qingxi; Xie, Yunchuan; Zhai, Raosheng

2018-06-05

Long noncoding RNA AFAP1‑AS1 has been shown to promote tumor progression in several human cancer types, such as thyroid cancer, tongue squamous cell carcinoma and lung cancer. However, the role of AFAP1‑AS1 in osteosarcoma (OS) has not been investigated. In the present study, the expression of AFAP1‑AS1 was significantly upregulated in OS tissues and cell lines. Moreover, AFAP1‑AS1 expression was negatively correlated with OS patient prognosis. Besides, AFAP1‑AS1 knockdown significantly inhibited the proliferation and invasion of OS cells in vitro. Furthermore, in vivo xenograft experiments indicated that AFAP1‑AS1 depletion delayed tumor growth. Regarding the underlying mechanism, AFAP1‑AS1 served as a sponge to repress the level of microRNA (miR)‑4695‑5p, which targeted transcription factor (TCF)4, a pivot effector of Wnt/β‑catenin signaling pathway. It was demonstrated that overexpression of AFAP1‑AS1 inhibited the expression of miR‑4695‑5p, while miR‑4695‑5p overexpression decreased TCF4 expression and reduced activation of Wnt/β‑catenin pathway. Through rescue assays, it was demonstrated that restoration of TCF4 expression reversed the effects of AFAP1‑AS1 knockdown or miR‑4695‑5p overexpression on OS cells. Taken together, these findings demonstrated that the AFAP1‑AS1/miR‑4695‑5p/TCF4‑β‑catenin axis played an important role in OS progression.

Mechanism of T7 RNAP pausing and termination at the T7 concatemer junction: a local change in transcription bubble structure drives a large change in transcription complex architecture.

PubMed

Nayak, Dhananjaya; Siller, Sylvester; Guo, Qing; Sousa, Rui

2008-02-15

The T7RNA polymerase (RNAP) elongation complex (EC) pauses and is destabilized at a unique 8 nucleotide (nt) sequence found at the junction of the head-to-tail concatemers of T7 genomic DNA generated during T7 DNA replication. The paused EC may recruit the T7 DNA processing machinery, which cleaves the concatemerized DNA within this 8 nt concatemer junction (CJ). Pausing of the EC at the CJ involves structural changes in both the RNAP and transcription bubble. However, these structural changes have not been fully defined, nor is it understood how the CJ sequence itself causes the EC to change its structure, to pause, and to become less stable. Here we use solution and RNAP-tethered chemical nucleases to probe the CJ transcript and changes in the EC structure as the polymerase pauses and terminates at the CJ. Together with extensive mutational scanning of regions of the polymerase that are likely to be involved in recognition of the CJ, we are able to develop a description of the events that occur as the EC transcribes through the CJ and subsequently pauses. In this process, a local change in the structure of the transcription bubble drives a large change in the architecture of the EC. This altered EC structure may then serve as the signal that recruits the processing machinery to the CJ.

Andrographolide Induces Cell Cycle Arrest and Apoptosis of Chondrosarcoma by Targeting TCF-1/SOX9 Axis.

PubMed

Zhang, Huan-Tian; Yang, Jie; Liang, Gui-Hong; Gao, Xue-Juan; Sang, Yuan; Gui, Tao; Liang, Zu-Jian; Tam, Man-Seng; Zha, Zhen-Gang

2017-12-01

Chondrosarcoma is the second most malignant bone tumor with poor prognosis and limited treatment options. Thus, development of more effective treatments has become urgent. Recently, natural compounds derived from medicinal plants have emerged as promising therapeutic options via targeting multiple key cellular molecules. Andrographolide (Andro) is such a compound, which has previously been shown to induce cell cycle arrest and apoptosis in several human cancers. However, the molecular mechanism through which Andro exerts its anti-cancer effect on chondrosarcoma remains to be elucidated. In the present study, we showed that Andro-induced G2/M cell cycle arrest of chondrosarcoma by fine-tuning the expressions of several cell cycle regulators such as p21, p27, and Cyclins, and that prolonged treatment of cells with Andro caused pronounced cell apoptosis. Remarkably, we found that SOX9 was highly expressed in poor-differentiated chondrosarcoma, and that knockdown of SOX9 suppressed chondrosarcoma cell growth. Further, our results showed that Andro dose-dependently down-regulated SOX9 expression in chondrosarcoma cells. Concomitantly, an inhibition of T cell factor 1 (TCF-1) mRNA expression and an enhancement of TCF-1 protein degradation by Andro were observed. In contrast, the expression and subcellular localization of β-catenin were not altered upon the treatment of Andro, suggesting that β-catenin might not function as the primary target of Andro. Additionally, we provided evidence that there was a mutual regulation between TCF-1 and SOX9 in chondrosarcoma cells. In conclusion, these results highlight the potential therapeutic effects of Andro in treatment of chondrosarcoma via targeting the TCF-1/SOX9 axis. J. Cell. Biochem. 118: 4575-4586, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Draft Genome Sequence of Lactobacillus sp. Strain TCF032-E4, Isolated from Fermented Radish.

PubMed

Mao, Yuejian; Chen, Meng; Horvath, Philippe

2015-07-30

Here, we report the draft genome sequence of Lactobacillus sp. strain TCF032-E4 (= CCTCC AB2015090 = DSM 100358), isolated from a Chinese fermented radish. The total length of the 57 contigs is about 2.9 Mb, with a G+C content of 43.5 mol% and 2,797 predicted coding sequences (CDSs). Copyright © 2015 Mao et al.

WNT10B Functional Dualism: β-Catenin/Tcf-dependent Growth Promotion or Independent Suppression with Deregulated Expression in Cancer

PubMed Central

Yoshikawa, Hirohide; Matsubara, Kenichi; Zhou, Xiaoling; Okamura, Shu; Kubo, Takahiko; Murase, Yaeko; Shikauchi, Yuko; Esteller, Manel; Herman, James G.; Wei Wang, Xin

2007-01-01

We found aberrant DNA methylation of the WNT10B promoter region in 46% of primary hepatocellular carcinoma (HCC) and 15% of colon cancer samples. Three of 10 HCC and one of two colon cancer cell lines demonstrated low or no expression, and 5-aza-2′deoxycytidine reactivated WNT10B expression with the induction of demethylation, indicating that WNT10B is silenced by DNA methylation in some cancers, whereas WNT10B expression is up-regulated in seven of the 10 HCC cell lines and a colon cancer cell line. These results indicate that WNT10B can be deregulated by either overexpression or silencing in cancer. We found that WNT10B up-regulated β-catenin/Tcf activity. However, WNT10B-overexpressing cells demonstrated a reduced growth rate and anchorage-independent growth that is independent of the β-catenin/Tcf activation, because mutant β-catenin–transduced cells did not suppress growth, and dominant-negative hTcf-4 failed to alleviate the growth suppression by WNT10B. Although WNT10B expression alone inhibits cell growth, it acts synergistically with the fibroblast growth factor (FGF) to stimulate cell growth. WNT10B is bifunctional, one function of which is involved in β-catenin/Tcf activation, and the other function is related to the down-regulation of cell growth through a different mechanism. We suggest that FGF switches WNT10B from a negative to a positive cell growth regulator. PMID:17761539

Functional Architecture of T7 RNA Polymerase Transcription Complexes

PubMed Central

Nayak, Dhananjaya; Guo, Qing; Sousa, Rui

2007-01-01

Summary T7 RNA polymerase is the best-characterized member of a widespread family of single-subunit RNA polymerases. Crystal structures of T7 RNA polymerase initiation and elongation complexes have provided a wealth of detailed information on RNA polymerase interactions with the promoter and transcription bubble, but the absence of DNA downstream of the melted region of the template in the initiation complex structure, and the absence of DNA upstream of the transcription bubble in the elongation complex structure means that our picture of the functional architecture of T7 RNA polymerase transcription complexes remains incomplete. Here we use the site-specifically tethered chemical nucleases and functional characterization of directed T7 RNAP mutants to both reveal the architecture of the duplex DNA that flanks the transcription bubble in the T7 RNAP initiation and elongation complexes, and to define the function of the interactions made by these duplex elements. We find that downstream duplex interactions made with a cluster of lysines (K711/K713/K714) are present during both elongation and initiation where they contribute to stabilizing a bend in the downstream DNA that is important for promoter opening. The upstream DNA in the elongation complex is also found to be sharply bent at the upstream edge of the transcription bubble, thereby allowing formation of upstream duplex:polymerase interactions that contribute to elongation complex stability. PMID:17580086

Genome-wide transcription analysis of histidine-related cataract in Atlantic salmon (Salmo salar L)

PubMed Central

Waagbø, Rune; Breck, Olav; Stavrum, Anne-Kristin; Petersen, Kjell; Olsvik, Pål A.

2009-01-01

Purpose Elevated levels of dietary histidine have previously been shown to prevent or mitigate cataract formation in farmed Atlantic salmon (Salmo salar L). The aim of this study was to shed light on the mechanisms by which histidine acts. Applying microarray analysis to the lens transcriptome, we screened for differentially expressed genes in search for a model explaining cataract development in Atlantic salmon and possible markers for early cataract diagnosis. Methods Adult Atlantic salmon (1.7 kg) were fed three standard commercial salmon diets only differing in the histidine content (9, 13, and 17 g histidine/kg diet) for four months. Individual cataract scores for both eyes were assessed by slit-lamp biomicroscopy. Lens N-acetyl histidine contents were measured by high performance liquid chromatography (HPLC). Total RNA extracted from whole lenses was analyzed using the GRASP 16K salmonid microarray. The microarray data were analyzed using J-Express Pro 2.7 and validated by quantitative real-time polymerase chain reaction (qRT–PCR). Results Fish developed cataracts with different severity in response to dietary histidine levels. Lens N-acetyl histidine contents reflected the dietary histidine levels and were negatively correlated to cataract scores. Significance analysis of microarrays (SAM) revealed 248 significantly up-regulated transcripts and 266 significantly down-regulated transcripts in fish that were fed a low level of histidine compared to fish fed a higher histidine level. Among the differentially expressed transcripts were metallothionein A and B as well as transcripts involved in lipid metabolism, carbohydrate metabolism, regulation of ion homeostasis, and protein degradation. Hierarchical clustering and correspondence analysis plot confirmed differences in gene expression between the feeding groups. The differentially expressed genes could be categorized as “early” and “late” responsive according to their expression pattern relative to

Characterization of Herpes Simplex Virus 2 Primary MicroRNA Transcript Regulation

PubMed Central

Bosch-Marce, Marta; Patel, Amita; Margolis, Todd P.

2015-01-01

ABSTRACT In order to understand factors that may influence latency-associated transcription and latency-associated transcript (LAT) phenotypes, we studied the expression of the herpes simplex virus 2 (HSV-2) LAT-associated microRNAs (miRNAs). We mapped the transcription initiation sites of all three primary miRNA transcripts and identified the ICP4-binding sequences at the transcription initiation sites of both HSV-2 LAT (pri-miRNA for miR-I and miR-II, which target ICP34.5, and miR-III, which targets ICP0) and L/ST (a pri-miRNA for miR-I and miR-II) but not at that of the primary miR-H6 (for which the target is unknown). We confirmed activity of the putative HSV-2 L/ST promoter and found that ICP4 trans-activates the L/ST promoter when the ICP4-binding site at its transcription initiation site is mutated, suggesting that ICP4 may play a dual role in regulating transcription of L/ST and, consequently, of miR-I and miR-II. LAT exon 1 (containing LAT enhancer sequences), together with the LAT promoter region, comprises a bidirectional promoter required for the expression of both LAT-encoded miRNAs and miR-H6 in latently infected mouse ganglia. The ability of ICP4 to suppress ICP34.5-targeting miRNAs and to activate lytic viral genes suggests that ICP4 could play a key role in the switch between latency and reactivation. IMPORTANCE The HSV-2 LAT and viral miRNAs expressed in the LAT region are the most abundant viral transcripts during HSV latency. The balance between the expression of LAT and LAT-associated miRNAs and the expression of lytic viral transcripts from the opposite strand appears to influence whether individual HSV-infected neurons will be latently or productively infected. The outcome of neuronal infection may thus depend on regulation of gene expression of the corresponding primary miRNAs. In the present study, we characterize promoter sequences responsible for miRNA expression, including identification of the primary miRNA 5′ ends and evaluation of

Association Analysis in African Americans of European-Derived Type 2 Diabetes Single Nucleotide Polymorphisms From Whole-Genome Association Studies

PubMed Central

Lewis, Joshua P.; Palmer, Nicholette D.; Hicks, Pamela J.; Sale, Michele M.; Langefeld, Carl D.; Freedman, Barry I.; Divers, Jasmin; Bowden, Donald W.

2008-01-01

OBJECTIVE— Several whole-genome association studies have reported identification of type 2 diabetes susceptibility genes in various European-derived study populations. Little investigation of these loci has been reported in other ethnic groups, specifically African Americans. Striking differences exist between these populations, suggesting they may not share identical genetic risk factors. Our objective was to examine the influence of type 2 diabetes genes identified in whole-genome association studies in a large African American case-control population. RESEARCH DESIGN AND METHODS— Single nucleotide polymorphisms (SNPs) in 12 loci (e.g., TCF7L2, IDE/KIF11/HHEX, SLC30A8, CDKAL1, PKN2, IGF2BP2, FLJ39370, and EXT2/ALX4) associated with type 2 diabetes in European-derived populations were genotyped in 993 African American type 2 diabetic and 1,054 African American control subjects. Additionally, 68 ancestry-informative markers were genotyped to account for the impact of admixture on association results. RESULTS— Little evidence of association was observed between SNPs, with the exception of those in TCF7L2, and type 2 diabetes in African Americans. One TCF7L2 SNP (rs7903146) showed compelling evidence of association with type 2 diabetes (admixture-adjusted additive P [Pa] = 1.59 × 10−6). Only the intragenic SNP on 11p12 (rs9300039, dominant P [Pd] = 0.029) was also associated with type 2 diabetes after admixture adjustments. Interestingly, four of the SNPs are monomorphic in the Yoruba population of the HAPMAP project, with only the risk allele from the populations of European descent present. CONCLUSIONS— Results suggest that these variants do not significantly contribute to interindividual susceptibility to type 2 diabetes in African Americans. Consequently, genes contributing to type 2 diabetes in African Americans may, in part, be different from those in European-derived study populations. High frequency of risk alleles in several of these genes may

Association analysis in african americans of European-derived type 2 diabetes single nucleotide polymorphisms from whole-genome association studies.

PubMed

Lewis, Joshua P; Palmer, Nicholette D; Hicks, Pamela J; Sale, Michele M; Langefeld, Carl D; Freedman, Barry I; Divers, Jasmin; Bowden, Donald W

2008-08-01

Several whole-genome association studies have reported identification of type 2 diabetes susceptibility genes in various European-derived study populations. Little investigation of these loci has been reported in other ethnic groups, specifically African Americans. Striking differences exist between these populations, suggesting they may not share identical genetic risk factors. Our objective was to examine the influence of type 2 diabetes genes identified in whole-genome association studies in a large African American case-control population. Single nucleotide polymorphisms (SNPs) in 12 loci (e.g., TCF7L2, IDE/KIF11/HHEX, SLC30A8, CDKAL1, PKN2, IGF2BP2, FLJ39370, and EXT2/ALX4) associated with type 2 diabetes in European-derived populations were genotyped in 993 African American type 2 diabetic and 1,054 African American control subjects. Additionally, 68 ancestry-informative markers were genotyped to account for the impact of admixture on association results. Little evidence of association was observed between SNPs, with the exception of those in TCF7L2, and type 2 diabetes in African Americans. One TCF7L2 SNP (rs7903146) showed compelling evidence of association with type 2 diabetes (admixture-adjusted additive P [P(a)] = 1.59 x 10(-6)). Only the intragenic SNP on 11p12 (rs9300039, dominant P [P(d)] = 0.029) was also associated with type 2 diabetes after admixture adjustments. Interestingly, four of the SNPs are monomorphic in the Yoruba population of the HAPMAP project, with only the risk allele from the populations of European descent present. Results suggest that these variants do not significantly contribute to interindividual susceptibility to type 2 diabetes in African Americans. Consequently, genes contributing to type 2 diabetes in African Americans may, in part, be different from those in European-derived study populations. High frequency of risk alleles in several of these genes may, however, contribute to the increased prevalence of type 2 diabetes in

Seroepidemiology of Human Papillomavirus 16 (HPV16) L2 and Generation of L2-Specific Human Chimeric Monoclonal Antibodies

PubMed Central

Wang, Joshua W.; Jagu, Subhashini; Wu, Wai-Hong; Viscidi, Raphael P.; Macgregor-Das, Anne; Fogel, Jessica M.; Kwak, Kihyuck; Daayana, Sai; Kitchener, Henry; Stern, Peter L.; Gravitt, Patti E.; Trimble, Cornelia L.

2015-01-01

Presently, the seroprevalence of human papillomavirus (HPV) minor capsid antigen L2-reactive antibody is not well understood, and no serologic standard exists for L2-specific neutralizing antibodies. Therefore, we screened a total of 1,078 serum samples for HPV16 L2 reactivity, and these were obtained from four prior clinical studies: a population-based (n = 880) surveillance study with a high-risk HPV DNA prevalence of 10.8%, a cohort study of women (n = 160) with high-grade cervical intraepithelial neoplasia (CIN), and two phase II trials in women with high-grade vulvar intraepithelial neoplasia (VIN) receiving imiquimod therapy combined with either photodynamic therapy (PDT) (n = 19) or vaccination with a fusion protein comprising HPV16 L2, E7, and E6 (TA-CIN) (n = 19). Sera were screened sequentially by HPV16 L2 enzyme-linked immunosorbent assay (ELISA) and then Western blot. Seven of the 1,078 serum samples tested had L2-specific antibodies, but none were detectably neutralizing for HPV16. To develop a standard, we substituted human IgG1 sequences into conserved regions of two rodent monoclonal antibodies (MAbs) specific for neutralizing epitopes at HPV16 L2 residues 17 to 36 and 58 to 64, creating JWW-1 and JWW-2, respectively. These chimeric MAbs retained neutralizing activity and together reacted with 33/34 clinically relevant HPV types tested. In conclusion, our inability to identify an HPV16 L2-specific neutralizing antibody response even in the sera of patients with active genital HPV disease suggests the subdominance of L2 protective epitopes and the value of the chimeric MAbs JWW-1 and JWW-2 as standards for immunoassays to measure L2-specific human antibodies. PMID:25972404

Integration of growth factor signals at the c-fos serum response element.

PubMed

Price, M A; Hill, C; Treisman, R

1996-04-29

A transcription factor ternary complex composed of serum response factor (SRF) and a second factor, ternary complex factor (TCF), mediates the response of the c-fos Serum Response Element to growth factors and mitogens. In NIH3T3 fibroblasts, TCF binding is required for transcriptional activation by the SRE in response to activation of the Ras-Raf-ERK pathway. We compared the properties of three members of the TCF family, Elk-1, SAP-1 and SAP-2 (ERP/NET). Although all the proteins contain sequences required for ternary complex formation with SRF, only Elk-1 and SAP-1 appear to interact with the c-fos SRE efficiently in vivo. Each TCF contains a C-terminal activation domain capable of transcriptional activation in response to activation of the Ras-Raf-ERK pathway, and this is dependent on the integrity of S/T-P motifs conserved between all the TCF family members. In contrast, activation of the SRE by whole serum and the mitogenic phospholipid LPA requires SRF binding alone. Constitutively activated members of the Rho subfamily of Ras-like GTPases are also capable of inducing activation of the SRE in the absence of TCF; unlike activated Ras itself, these proteins do not activate the TCFs in NIH3T3 cells. At the SRE, SRF- and TCF-linked signalling pathways act synergistically to potentiate transcription.

Transcriptional machinery of TNF-α-inducible YTH domain containing 2 (YTHDC2) gene.

PubMed

Tanabe, Atsushi; Konno, Junpei; Tanikawa, Kenya; Sahara, Hiroeki

2014-02-01

We previously demonstrated that a cellular factor, cyclosporin A (CsA) associated helicase-like protein (CAHL) that is identical to YTH domain containing 2 (YTHDC2), forms trimer complex with cyclophilin B and NS5B of hepatitis C virus (HCV) and facilitates HCV genome replication. Gene expression of YTHDC2 was shown in tumor cell lines and tumor necrosis factor (TNF)-α-treated hepatocytes, but not in untreated. However, the function of YTHDC2 in the tumor cells and the mechanism by which the YTHDC2 gene is transcribed in these cells is largely unknown. We first evaluated that the role of YTHDC2 in the proliferation of hepatocellular carcinoma (HCC) cell line Huh7 using RNA interference and found that YTHDC2-downregulated Huh7 were significantly decreased cell growth as compared to control. We next demonstrated that the cAMP response element (CRE) site in the promoter region of the YTHDC2 gene is critical for YTHDC2 transcription. To further investigate the transcription factors bound to the CRE site, we performed chromatin immunoprecipitation assays. Our findings demonstrate that c-Jun and ATF-2 bind to the CRE site in Huh7, and that TNF-α induces the biological activity of these transcription factors in hepatocytes as well as Huh7. Moreover, treatment with the HDAC inhibitor, trichostatin A (TSA), reduces YTHDC2 expression in Huh7 and in TNF-α-stimulated hepatocytes. Collectively, these data show that YTHDC2 plays an important role in tumor cells growth and activation/recruitment of c-Jun and ATF-2 to the YTHDC2 promoter is necessary for the transcription of YTHDC2, and that HDAC activity is required for the efficient expression of YTHDC2 in both of hepatocyte and HCC cells. Copyright © 2013 Elsevier B.V. All rights reserved.

Transcriptional Dynamics of LTR Retrotransposons in Early Generation and Ancient Sunflower Hybrids

PubMed Central

Ungerer, Mark C.; Kawakami, Takeshi

2013-01-01

Hybridization and abiotic stress are natural agents hypothesized to influence activation and proliferation of transposable elements in wild populations. In this report, we examine the effects of these agents on expression dynamics of both quiescent and transcriptionally active sublineages of long terminal repeat (LTR) retrotransposons in wild sunflower species with a notable history of transposable element proliferation. For annual sunflower species Helianthus annuus and H. petiolaris, neither early generation hybridization nor abiotic stress, alone or in combination, induced transcriptional activation of quiescent sublineages of LTR retrotransposons. These treatments also failed to further induce expression of sublineages that are transcriptionally active; instead, expression of active sublineages in F1 and backcross hybrids was nondistinguishable from, or intermediate relative to, parental lines, and abiotic stress generally decreased normalized expression relative to controls. In contrast to findings for early generation hybridization between H. annuus and H. petiolaris, ancient sunflower hybrid species derived from these same two species and which have undergone massive proliferation events of LTR retrotransposons display 2× to 6× higher expression levels of transcriptionally active sublineages relative to parental sunflower species H. annuus and H. petiolaris. Implications and possible explanations for these findings are discussed. PMID:23335122

Imprinting regulator DNMT3L is a transcriptional repressor associated with histone deacetylase activity.

PubMed

Aapola, Ulla; Liiv, Ingrid; Peterson, Pärt

2002-08-15

DNMT3L is a regulator of imprint establishment of normally methylated maternal genomic sequences. DNMT3L shows high similarity to the de novo DNA methyltransferases, DNMT3A and DNMT3B, however, the amino acid residues needed for DNA cytosine methyltransferase activity have been lost from the DNMT3L protein sequence. Apart from methyltransferase activity, Dnmt3a and Dnmt3b serve as transcriptional repressors associating with histone deacetylase (HDAC) activity. Here we show that DNMT3L can also repress transcription by binding directly to HDAC1 protein. We have identified the PHD-like zinc finger of the ATRX domain as a main repression motif of DNMT3L, through which DNMT3L recruits the HDAC activity needed for transcriptional silencing. Furthermore, we show that DNMT3L protein contains an active nuclear localisation signal at amino acids 156-159. These results describe DNMT3L as a co-repressor protein and suggest that a transcriptionally repressed chromatin organisation through HDAC activity is needed for establishment of genomic imprints.

Galpha13 regulates MEF2-dependent gene transcription in endothelial cells: role in angiogenesis.

PubMed

Liu, Guoquan; Han, Jingyan; Profirovic, Jasmina; Strekalova, Elena; Voyno-Yasenetskaya, Tatyana A

2009-01-01

The alpha subunit of heterotrimeric G13 protein is required for the embryonic angiogenesis (Offermanns et al., Science 275:533-536, 1997). However, the molecular mechanism of Galpha13-dependent angiogenesis is not understood. Here, we show that myocyte-specific enhancer factor-2 (MEF2) mediates Galpha13-dependent angiogenesis. Our data showed that constitutively activated Galpha13Q226L stimulated MEF2-dependent gene transcription. In addition, downregulation of endogenous Galpha13 inhibited thrombin-stimulated MEF2-dependent gene transcription in endothelial cells. Both Ca(2+)/calmodulin-dependent kinase IV (CaMKIV) and histone deacetylase 5 (HDAC5) were involved in Galpha13-mediated MEF2-dependent gene transcription. Galpha13Q226L also increased Ca(2+)/calmodulin-independent CaMKIV activity, while dominant negative mutant of CaMKIV inhibited MEF2-dependent gene transcription induced by Galpha13Q226L. Furthermore, Galpha13Q226L was able to derepress HDAC5-mediated repression of gene transcription and induce the translocation of HDAC5 from nucleus to cytoplasm. Finally, downregulation of endogenous Galpha13 and MEF2 proteins in endothelial cells reduced cell proliferation and capillary tube formation. Decrease of endothelial cell proliferation that was caused by the Galpha13 downregulation was partially restored by the constitutively active MEF2-VP16. Our studies suggest that MEF2 proteins are an important component in Galpha13-mediated angiogenesis.

7SK snRNP/P-TEFb couples transcription elongation with alternative splicing and is essential for vertebrate development

PubMed Central

Barboric, Matjaz; Lenasi, Tina; Chen, Hui; Johansen, Eric B.; Guo, Su; Peterlin, B. Matija

2009-01-01

Eukaryotic gene expression is commonly controlled at the level of RNA polymerase II (RNAPII) pausing subsequent to transcription initiation. Transcription elongation is stimulated by the positive transcription elongation factor b (P-TEFb) kinase, which is suppressed within the 7SK small nuclear ribonucleoprotein (7SK snRNP). However, the biogenesis and functional significance of 7SK snRNP remain poorly understood. Here, we report that LARP7, BCDIN3, and the noncoding 7SK small nuclear RNA (7SK) are vital for the formation and stability of a cell stress-resistant core 7SK snRNP. Our functional studies demonstrate that 7SK snRNP is not only critical for controlling transcription elongation, but also for regulating alternative splicing of pre-mRNAs. Using a transient expression splicing assay, we find that 7SK snRNP disintegration promotes inclusion of an alternative exon via the increased occupancy of P-TEFb, Ser2-phosphorylated (Ser2-P) RNAPII, and the splicing factor SF2/ASF at the minigene. Importantly, knockdown of larp7 or bcdin3 orthologues in zebrafish embryos destabilizes 7SK and causes severe developmental defects and aberrant splicing of analyzed transcripts. These findings reveal a key role for P-TEFb in coupling transcription elongation with alternative splicing, and suggest that maintaining core 7SK snRNP is essential for vertebrate development. PMID:19416841

Effects of Synonym Generation on Incidental and Intentional L2 Vocabulary Learning during Reading

ERIC Educational Resources Information Center

Barcroft, Joe

2009-01-01

This study examined effects of synonym generation on second language (L2) vocabulary learning during reading in both incidental and intentional vocabulary learning contexts. Spanish-speaking adult learners of L2 English (N = 114) at low- and high-intermediate proficiency levels read an English passage containing 10 target words translated in the…

The BSD2 ortholog in Chlamydomonas reinhardtii is a polysome-associated chaperone that co-migrates on sucrose gradients with the rbcL transcript encoding the Rubisco large subunit.

PubMed

Doron, Lior; Segal, Na'ama; Gibori, Hadas; Shapira, Michal

2014-10-01

The expression of the CO2 -fixation enzyme ribulose-bisphosphate carboxylase/oxygenase (Rubisco), which is affected by light, involves the cysteine-rich protein bundle-sheath defective-2 (BSD2) that was originally identified in maize bundle-sheath cells. We identified the BSD2 ortholog in Chlamydomonas reinhardtii as a small protein (17 kDa) localized to the chloroplast. The algal BSD2-ortholog contains four CXXCXGXG DnaJ-like elements, but lacks the other conserved domains of DnaJ. BSD2 co-migrated with the rbcL transcript on heavy polysomes, and both BSD2 and rbcL mRNA shifted to the lighter fractions under oxidizing conditions that repress the translation of the Rubisco large subunit (RbcL). This profile of co-migration supports the possibility that BSD2 is required for the de novo synthesis of RbcL. Furthermore, BSD2 co-migrated with the rbcL transcript in a C. reinhardtii premature-termination mutant that encodes the first 60 amino acids of RbcL. In both strains, BSD2 shared its migration profile with the rbcL transcript but not with psbA mRNA. The chaperone activity of BSD2 was exemplified by its ability to prevent the aggregation of both citrate synthase (CS) and RbcL in vitro following their chemical denaturation. This activity did not depend on the presence of the thiol groups on BSD2. In contrast, the activity of BSD2 in preventing the precipitation of reduced β-chains in vitro in the insulin turbidity assay was thiol-dependent. We conclude that BSD2 combines a chaperone 'holdase' function with the ability to interact with free thiols, with both activities being required to protect newly synthesized RbcL chains. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

Characterization of herpes simplex virus 2 primary microRNA Transcript regulation.

PubMed

Tang, Shuang; Bosch-Marce, Marta; Patel, Amita; Margolis, Todd P; Krause, Philip R

2015-05-01

In order to understand factors that may influence latency-associated transcription and latency-associated transcript (LAT) phenotypes, we studied the expression of the herpes simplex virus 2 (HSV-2) LAT-associated microRNAs (miRNAs). We mapped the transcription initiation sites of all three primary miRNA transcripts and identified the ICP4-binding sequences at the transcription initiation sites of both HSV-2 LAT (pri-miRNA for miR-I and miR-II, which target ICP34.5, and miR-III, which targets ICP0) and L/ST (a pri-miRNA for miR-I and miR-II) but not at that of the primary miR-H6 (for which the target is unknown). We confirmed activity of the putative HSV-2 L/ST promoter and found that ICP4 trans-activates the L/ST promoter when the ICP4-binding site at its transcription initiation site is mutated, suggesting that ICP4 may play a dual role in regulating transcription of L/ST and, consequently, of miR-I and miR-II. LAT exon 1 (containing LAT enhancer sequences), together with the LAT promoter region, comprises a bidirectional promoter required for the expression of both LAT-encoded miRNAs and miR-H6 in latently infected mouse ganglia. The ability of ICP4 to suppress ICP34.5-targeting miRNAs and to activate lytic viral genes suggests that ICP4 could play a key role in the switch between latency and reactivation. The HSV-2 LAT and viral miRNAs expressed in the LAT region are the most abundant viral transcripts during HSV latency. The balance between the expression of LAT and LAT-associated miRNAs and the expression of lytic viral transcripts from the opposite strand appears to influence whether individual HSV-infected neurons will be latently or productively infected. The outcome of neuronal infection may thus depend on regulation of gene expression of the corresponding primary miRNAs. In the present study, we characterize promoter sequences responsible for miRNA expression, including identification of the primary miRNA 5' ends and evaluation of ICP4 response. These

Methylation of transcription factor YY2 regulates its transcriptional activity and cell proliferation

PubMed Central

Wu, Xiao-nan; Shi, Tao-tao; He, Yao-hui; Wang, Fei-fei; Sang, Rui; Ding, Jian-cheng; Zhang, Wen-juan; Shu, Xing-yi; Shen, Hai-feng; Yi, Jia; Gao, Xiang; Liu, Wen

2017-01-01

Yin Yang 1 (YY1) is a multifunctional DNA-binding transcription factor shown to be critical in a variety of biological processes, and its activity and function have been shown to be regulated by multitude of mechanisms, which include but are not limited to post-translational modifications (PTMs), its associated proteins and cellular localization. YY2, the paralog of YY1 in mouse and human, has been proposed to function redundantly or oppositely in a context-specific manner compared with YY1. Despite its functional importance, how YY2’s DNA-binding activity and function are regulated, particularly by PTMs, remains completely unknown. Here we report the first PTM with functional characterization on YY2, namely lysine 247 monomethylation (K247me1), which was found to be dynamically regulated by SET7/9 and LSD1 both in vitro and in cultured cells. Functional study revealed that SET7/9-mediated YY2 methylation regulated its DNA-binding activity in vitro and in association with chromatin examined by chromatin immunoprecipitation coupled with sequencing (ChIP-seq) in cultured cells. Knockout of YY2, SET7/9 or LSD1 by CRISPR (clustered, regularly interspaced, short palindromic repeats)/Cas9-mediated gene editing followed by RNA sequencing (RNA-seq) revealed that a subset of genes was positively regulated by YY2 and SET7/9, but negatively regulated by LSD1, which were enriched with genes involved in cell proliferation regulation. Importantly, YY2-regulated gene transcription, cell proliferation and tumor growth were dependent, at least partially, on YY2 K247 methylation. Finally, somatic mutations on YY2 found in cancer, which are in close proximity to K247, altered its methylation, DNA-binding activity and gene transcription it controls. Our findings revealed the first PTM with functional implications imposed on YY2 protein, and linked YY2 methylation with its biological functions. PMID:29098080

Effect of environmentally-relevant concentrations of nonylphenol on sexual differentiation in zebrafish: a multi-generational study

NASA Astrophysics Data System (ADS)

Sun, Dong; Chen, Qi; He, Ning; Diao, Pan-Pan; Jia, Li-Xing; Duan, Shun-Shan

2017-02-01

Nonylphenol (NP) is a persistent environmental chemical that can disrupt the organism’s endocrine system, and is detected in the surface water and sea. In this study, we investigated whether NP can alter transcriptional expression of sexual differentiation-related genes. Three generations of zebrafish were exposed to 0, 2, 20 and 200 μg·L-1 of NP, and transcriptional expression of sexual differentiation genes were assessed in 10, 20 and 40 dpf in the F1 and F2 generations. Growth of zebrafish exposed to 200 μg·L-1 of NP was inhibited at 125 dpf in the F1 generation. 20 μg·L-1 of NP resulted in 80% females in the F1 generation, but had no effect on the F2 generation. In terms of the sexual differentiation genes, the transcriptional expression of cyp19a1a and esr1 genes were upregulated in 20 μg·L-1 of NP in the F1 generation. But expression of the sexual differentiation genes were not affected in the F2 generation. Overall, NP could affect sexual differentiation and gene transcriptional expression in the F1 generation. The tolerance of contaminant in the offsprings was improved at low concentration.

A novel genome-wide in vivo screen for metastatic suppressors in human colon cancer identifies the positive WNT-TCF pathway modulators TMED3 and SOX12

PubMed Central

Duquet, Arnaud; Melotti, Alice; Mishra, Sonakshi; Malerba, Monica; Seth, Chandan; Conod, Arwen; Ruiz i Altaba, Ariel

2014-01-01

The progression of tumors to the metastatic state involves the loss of metastatic suppressor functions. Finding these, however, is difficult as in vitro assays do not fully predict metastatic behavior, and the majority of studies have used cloned cell lines, which do not reflect primary tumor heterogeneity. Here, we have designed a novel genome-wide screen to identify metastatic suppressors using primary human tumor cells in mice, which allows saturation screens. Using this unbiased approach, we have tested the hypothesis that endogenous colon cancer metastatic suppressors affect WNT-TCF signaling. Our screen has identified two novel metastatic suppressors: TMED3 and SOX12, the knockdown of which increases metastatic growth after direct seeding. Moreover, both modify the type of self-renewing spheroids, but only knockdown of TMED3 also induces spheroid cell spreading and lung metastases from a subcutaneous xenograft. Importantly, whereas TMED3 and SOX12 belong to different families involved in protein secretion and transcriptional regulation, both promote endogenous WNT-TCF activity. Treatments for advanced or metastatic colon cancer may thus not benefit from WNT blockers, and these may promote a worse outcome. PMID:24920608

The Association of Type 2 Diabetes Loci Identified in Genome-Wide Association Studies with Metabolic Syndrome and Its Components in a Chinese Population with Type 2 Diabetes

PubMed Central

Xing, Xiaoyan; Zhang, Bo; Hong, Jing; Yang, Wenying

2015-01-01

Metabolic syndrome (MetS) is prevalent in type 2 diabetes (T2D) patients. The comorbidity of MetS and T2D increases the risk of cardiovascular complications. The aim of the present study was to determine the T2D-related genetic variants that contribute to MetS-related components in T2D patients of Chinese ancestry. We successfully genotyped 25 genome wide association study validated T2D-related single nucleotide polymorphisms (SNPs) among 5,169 T2D individuals and 4,560 normal glycemic controls recruited from the Chinese National Diabetes and Metabolic Disorders Study (DMS). We defined MetS in this population using the harmonized criteria (2009) combined with the Chinese criteria for abdominal obesity. The associations between SNPs and MetS-related components, as well as the associations between SNPs and risk for T2D with or without MetS, were subjected to logistic regression analysis adjusted for age and sex. Results showed that the T2D risk alleles of rs243021 located near BCL11A, rs10830963 in MTNR1B, and rs2237895 in KCNQ1 were related to a lower risk for abdominal obesity in T2D patients (rs243021: 0.92 (0.84, 1.00), P = 4.42 × 10−2; rs10830963: 0.92 (0.85, 1.00), P = 4.07 × 10−2; rs2237895: 0.89 (0.82, 0.98), P = 1.29 × 10−2). The T2D risk alleles of rs972283 near KLF14 contributed to a higher risk of elevated blood pressure (1.10 (1.00, 1.22), P = 4.48 × 10−2), while the T2D risk allele of rs7903146 in TCF7L2 was related to a lower risk for elevated blood pressure (0.74 (0.61, 0.90), P = 2.56 × 10−3). The T2D risk alleles of rs972283 near KLF14 and rs11634397 near ZFAND6 were associated with a higher risk for elevated triglycerides (rs972283: 1.11 (1.02, 1.24), P = 1.46 × 10−2; rs11634397: 1.14 (1.00, 1.29), P = 4.66 × 10−2), while the T2D risk alleles of rs780094 in GCKR and rs7903146 in TCF7L2 were related to a lower risk of elevated triglycerides (rs780094: 0.86 (0.80, 0.93), P = 1.35 × 10−4; rs7903146: 0.82 (0.69, 0.98), P = 3

Identification of a New Human Adenovirus Protein Encoded by a Novel Late l-Strand Transcription Unit▿

PubMed Central

Tollefson, Ann E.; Ying, Baoling; Doronin, Konstantin; Sidor, Peter D.; Wold, William S. M.

2007-01-01

A short open reading frame named the “U exon,” located on the adenovirus (Ad) l-strand (for leftward transcription) between the early E3 region and the fiber gene, is conserved in mastadenoviruses. We have observed that Ad5 mutants with large deletions in E3 that infringe on the U exon display a mild growth defect, as well as an aberrant Ad E2 DNA-binding protein (DBP) intranuclear localization pattern and an apparent failure to organize replication centers during late infection. Mutants in which the U exon DNA is reconstructed have a reversed phenotype. Chow et al. (L. T. Chow et al., J. Mol. Biol. 134:265-303, 1979) described mRNAs initiating in the region of the U exon and spliced to downstream sequences in the late DBP mRNA leader and the DBP-coding region. We have cloned this mRNA (as cDNA) from Ad5 late mRNA; the predicted protein is 217 amino acids, initiating in the U exon and continuing in frame in the DBP leader and in the DBP-coding region but in a different reading frame from DBP. Polyclonal and monoclonal antibodies generated against the predicted U exon protein (UXP) showed that UXP is ∼24K in size by immunoblot and is a late protein. At 18 to 24 h postinfection, UXP is strongly associated with nucleoli and is found throughout the nucleus; later, UXP is associated with the periphery of replication centers, suggesting a function relevant to Ad DNA replication or RNA transcription. UXP is expressed by all four species C Ads. When expressed in transient transfections, UXP complements the aberrant DBP localization pattern of UXP-negative Ad5 mutants. Our data indicate that UXP is a previously unrecognized protein derived from a novel late l-strand transcription unit. PMID:17881437

Genome-wide association analysis in primary sclerosing cholangitis and ulcerative colitis identifies risk loci at GPR35 and TCF4.

PubMed

Ellinghaus, David; Folseraas, Trine; Holm, Kristian; Ellinghaus, Eva; Melum, Espen; Balschun, Tobias; Laerdahl, Jon K; Shiryaev, Alexey; Gotthardt, Daniel N; Weismüller, Tobias J; Schramm, Christoph; Wittig, Michael; Bergquist, Annika; Björnsson, Einar; Marschall, Hanns-Ulrich; Vatn, Morten; Teufel, Andreas; Rust, Christian; Gieger, Christian; Wichmann, H-Erich; Runz, Heiko; Sterneck, Martina; Rupp, Christian; Braun, Felix; Weersma, Rinse K; Wijmenga, Cisca; Ponsioen, Cyriel Y; Mathew, Christopher G; Rutgeerts, Paul; Vermeire, Séverine; Schrumpf, Erik; Hov, Johannes R; Manns, Michael P; Boberg, Kirsten M; Schreiber, Stefan; Franke, Andre; Karlsen, Tom H

2013-09-01

Approximately 60%-80% of patients with primary sclerosing cholangitis (PSC) have concurrent ulcerative colitis (UC). Previous genome-wide association studies (GWAS) in PSC have detected a number of susceptibility loci that also show associations in UC and other immune-mediated diseases. We aimed to systematically compare genetic associations in PSC with genotype data in UC patients with the aim of detecting new susceptibility loci for PSC. We performed combined analyses of GWAS for PSC and UC comprising 392 PSC cases, 987 UC cases, and 2,977 controls and followed up top association signals in an additional 1,012 PSC cases, 4,444 UC cases, and 11,659 controls. We discovered novel genome-wide significant associations with PSC at 2q37 [rs3749171 at G-protein-coupled receptor 35 (GPR35); P = 3.0 × 10(-9) in the overall study population, combined odds ratio [OR] and 95% confidence interval [CI] of 1.39 (1.24-1.55)] and at 18q21 [rs1452787 at transcription factor 4 (TCF4); P = 2.61 × 10(-8) , OR (95% CI) = 0.75 (0.68-0.83)]. In addition, several suggestive PSC associations were detected. The GPR35 rs3749171 is a missense single nucleotide polymorphism resulting in a shift from threonine to methionine. Structural modeling showed that rs3749171 is located in the third transmembrane helix of GPR35 and could possibly alter efficiency of signaling through the GPR35 receptor. By refining the analysis of a PSC GWAS by parallel assessments in a UC GWAS, we were able to detect two novel risk loci at genome-wide significance levels. GPR35 shows associations in both UC and PSC, whereas TCF4 represents a PSC risk locus not associated with UC. Both loci may represent previously unexplored aspects of PSC pathogenesis. Copyright © 2012 American Association for the Study of Liver Diseases.

Transcriptional activation of mouse mast cell Protease-7 by activin and transforming growth factor-beta is inhibited by microphthalmia-associated transcription factor.

PubMed

Funaba, Masayuki; Ikeda, Teruo; Murakami, Masaru; Ogawa, Kenji; Tsuchida, Kunihiro; Sugino, Hiromu; Abe, Matanobu

2003-12-26

Previous studies have revealed that activin A and transforming growth factor-beta1 (TGF-beta1) induced migration and morphological changes toward differentiation in bone marrow-derived cultured mast cell progenitors (BMCMCs). Here we show up-regulation of mouse mast cell protease-7 (mMCP-7), which is expressed in differentiated mast cells, by activin A and TGF-beta1 in BMCMCs, and the molecular mechanism of the gene induction of mmcp-7. Smad3, a signal mediator of the activin/TGF-beta pathway, transcriptionally activated mmcp-7. Microphthalmia-associated transcription factor (MITF), a tissue-specific transcription factor predominantly expressed in mast cells, melanocytes, and heart and skeletal muscle, inhibited Smad3-mediated mmcp-7 transcription. MITF associated with Smad3, and the C terminus of MITF and the MH1 and linker region of Smad3 were required for this association. Complex formation between Smad3 and MITF was neither necessary nor sufficient for the inhibition of Smad3 signaling by MITF. MITF inhibited the transcriptional activation induced by the MH2 domain of Smad3. In addition, MITF-truncated N-terminal amino acids could associate with Smad3 but did not inhibit Smad3-mediated transcription. The level of Smad3 was decreased by co-expression of MITF but not of dominant-negative MITF, which resulted from proteasomal protein degradation. The changes in the level of Smad3 protein were paralleled by those in Smad3-mediated signaling activity. These findings suggest that MITF negatively regulates Smad-dependent activin/TGF-beta signaling in a tissue-specific manner.

Replication of genome-wide association signals in Asian Indians with early-onset type 2 diabetes.

PubMed

Chidambaram, Manickam; Liju, Samuel; Saboo, Banshi; Sathyavani, Kumpatla; Viswanathan, Vijay; Pankratz, Nathan; Gross, Myron; Mohan, Viswanathan; Radha, Venkatesan

2016-12-01

To evaluate the association of 87 genetic variants previously associated with type 2 diabetes mellitus (T2DM) in genome-wide association studies of populations of European ancestry in an Asian Indian population with early-onset type 2 diabetes mellitus (EOT2DM). The study groups comprised of 877 type 2 diabetes individuals, 436 individuals with EOT2DM (age at diagnosis below 35 years), 441 individuals with older T2DM (diagnosis at 35 years or greater) and controls with normal glucose tolerance (NGT) (n = 400 younger than 35 years; n = 438 older than 35 years). The participants were genotyped for 87 SNPs from 44 genes and 27 intergenic loci. Associations were tested using logistic regression. All the variants in TCF7L2 and CDKN2A/2B showed study-wide significance (p < 1.4 × 10 -4 ) with T2DM, but only rs7903146, rs12243326, rs12255372 of TCF7L2 and rs7020996 of CDKN2A/2B showed study-wide significance (p < 1.4 × 10 -4 ) with EOT2DM in this population. In addition, an intergenic SNP on chromosome 1 (rs10493685) was also shown to be study-wide significant (p = 7.1 × 10 -6 ). Several additional SNPs previously associated with T2DM reached borderline significance in this study, but may have been limited by relatively low sample numbers. Various other SNPs of T2DM were not associated with EOT2DM. Some of the variants in TCF7L2 and CDKN2A/2B associated with T2DM are associated with EOT2DM as well. An intergenic SNP on chromosome 1p31 showed association only with early-onset T2DM in this Asian Indian population. The lack of association with many other SNPs of T2DM may be a reflection of the lack of power of the study, sample size, differences in the frequencies of genetic polymorphisms in different ethnic groups, effect sizes, as well as ancestral differences in pattern of LD between the genetic variants involved in early- and late-onset T2DM.

Transcriptional deregulation of homeobox gene ZHX2 in Hodgkin lymphoma.

PubMed

Nagel, Stefan; Schneider, Björn; Meyer, Corinna; Kaufmann, Maren; Drexler, Hans G; Macleod, Roderick A F

2012-05-01

Recently, we identified a novel chromosomal rearrangement in Hodgkin lymphoma (HL), t(4;8)(q27;q24), which targets homeobox gene ZHX2 at the recurrent breakpoint 8q24. This aberration deletes the far upstream region of ZHX2 and results in silenced transcription pinpointing loss of activatory elements. Here, we have looked for potential binding sites within this deleted region to analyze the transcriptional deregulation of this tumor suppressor gene in B-cell malignancies. SiRNA-mediated knockdown and reporter gene analyses identified two transcription factors, homeodomain protein MSX1 and bZIP protein XBP1, directly regulating ZHX2 expression. Furthermore, MSX1-cofactor histone H1C mediated repression of ZHX2 and showed enhanced expression levels in cell line L-1236. As demonstrated by fluorescence in situ hybridization and genomic array analysis, the gene loci of MSX1 at 4p16 and H1C at 6p22 were rearranged in several HL cell lines, correlating with their altered expression activity. The expression of XBP1 was reduced in 6/7 HL cell lines as compared to primary hematopoietic cells. Taken together, our results demonstrate multiple mechanisms decreasing expression of tumor suppressor gene ZHX2 in HL cell lines: loss of enhancing binding sites, reduced expression of activators MSX1 and XBP1, and overexpression of MSX1-corepressor H1C. Moreover, chromosomal deregulations of genes involved in this regulative network highlight their role in development and malignancy of B-cells. Copyright © 2011 Elsevier Ltd. All rights reserved.

Polyphenol Compound as a Transcription Factor Inhibitor.

PubMed

Park, Seyeon

2015-10-30

A target-based approach has been used to develop novel drugs in many therapeutic fields. In the final stage of intracellular signaling, transcription factor-DNA interactions are central to most biological processes and therefore represent a large and important class of targets for human therapeutics. Thus, we focused on the idea that the disruption of protein dimers and cognate DNA complexes could impair the transcriptional activation and cell transformation regulated by these proteins. Historically, natural products have been regarded as providing the primary leading compounds capable of modulating protein-protein or protein-DNA interactions. Although their mechanism of action is not fully defined, polyphenols including flavonoids were found to act mostly as site-directed small molecule inhibitors on signaling. There are many reports in the literature of screening initiatives suggesting improved drugs that can modulate the transcription factor interactions responsible for disease. In this review, we focus on polyphenol compound inhibitors against dimeric forms of transcription factor components of intracellular signaling pathways (for instance, c-jun/c-fos (Activator Protein-1; AP-1), c-myc/max, Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and β-catenin/T cell factor (Tcf)).

ATXN1L, CIC, and ETS Transcription Factors Modulate Sensitivity to MAPK Pathway Inhibition

PubMed Central

Wang, Belinda; Krall, Elsa Beyer; Aguirre, Andrew James; Kim, Miju; Widlund, Hans Ragnar; Doshi, Mihir Bhavik; Sicinska, Ewa; Sulahian, Rita; Goodale, Amy; Cowley, Glenn Spencer; Piccioni, Federica; Doench, John Gerard; Root, David Edward; Hahn, William Chun

2017-01-01

SUMMARY Intrinsic resistance and RTK-RAS-MAPK pathway reactivation has limited the effectiveness of MEK and RAF inhibitors (MAPKi) in RAS- and RAF-mutant cancers. To identify genes that modulate sensitivity to MAPKi, we performed genome scale CRISPR-Cas9 loss-of-function screens in two KRAS-mutant pancreatic cancer cell lines treated with the MEK1/2 inhibitor trametinib. Loss of CIC, a transcriptional repressor of ETV1, 4, and 5, promoted survival in the setting of MAPKi in cancer cells derived from several lineages. ATXN1L deletion, which reduces CIC protein, or ectopic expression of ETV1, 4, or 5 also modulated sensitivity to trametinib. ATXN1L expression inversely correlates with response to MAPKi inhibition in clinical studies. These observations identify the ATXN1L-CIC-ETS transcription factor axis as a mediator of resistance to MAPKi. PMID:28178529

DOT1L and H3K79 Methylation in Transcription and Genomic Stability.

PubMed

Wood, Katherine; Tellier, Michael; Murphy, Shona

2018-02-27

The organization of eukaryotic genomes into chromatin provides challenges for the cell to accomplish basic cellular functions, such as transcription, DNA replication and repair of DNA damage. Accordingly, a range of proteins modify and/or read chromatin states to regulate access to chromosomal DNA. Yeast Dot1 and the mammalian homologue DOT1L are methyltransferases that can add up to three methyl groups to histone H3 lysine 79 (H3K79). H3K79 methylation is implicated in several processes, including transcription elongation by RNA polymerase II, the DNA damage response and cell cycle checkpoint activation. DOT1L is also an important drug target for treatment of mixed lineage leukemia (MLL)-rearranged leukemia where aberrant transcriptional activation is promoted by DOT1L mislocalisation. This review summarizes what is currently known about the role of Dot1/DOT1L and H3K79 methylation in transcription and genomic stability.

The Development of L2 Oral Language Skills in Two L1 Groups: A 7-Year Study

ERIC Educational Resources Information Center

Derwing, Tracey M.; Munro, Murray J.

2013-01-01

Researching the longitudinal development of second language (L2) learners is essential to understanding influences on their success. This 7-year study of oral skills in adult immigrant learners of English as a second language evaluated comprehensibility, fluency, and accentedness in first-language (L1) Mandarin and Slavic language speakers. The…

Genetic variant in the IGF2BP2 gene may interact with fetal malnutrition to affect glucose metabolism.

PubMed

van Hoek, Mandy; Langendonk, Janneke G; de Rooij, Susanne R; Sijbrands, Eric J G; Roseboom, Tessa J

2009-06-01

Fetal malnutrition may predispose to type 2 diabetes through gene programming and developmental changes. Previous studies showed that these effects may be modulated by genetic variation. Genome-wide association studies discovered and replicated a number of type 2 diabetes-associated genes. We investigated the effects of such well-studied polymorphisms and their interactions with fetal malnutrition on type 2 diabetes risk and related phenotypes in the Dutch Famine Birth Cohort. The rs7754840 (CDKAL1), rs10811661 (CDKN2AB), rs1111875 (HHEX), rs4402960 (IGF2BP2), rs5219 (KCNJ11), rs13266634 (SLC30A8), and rs7903146 (TCF7L2) polymorphisms were genotyped in 772 participants of the Dutch Famine Birth Cohort Study (n = 328 exposed, n = 444 unexposed). Logistic and linear regression models served to analyze their interactions with prenatal exposure to famine on type 2 diabetes, impaired glucose tolerance (IGT), and area under the curves (AUCs) for glucose and insulin during oral glucose tolerance testing (OGTT). In the total population, the TCF7L2 and IGF2BP2 variants most strongly associated with increased risk for type 2 diabetes/IGT and increased AUC for glucose, while the CDKAL1 polymorphism associated with decreased AUC for insulin. The IGF2BP2 polymorphism showed an interaction with prenatal exposure to famine on AUC for glucose (beta = -9.2 [95% CI -16.2 to -2.1], P = 0.009). The IGF2BP2 variant showed a nominal interaction with exposure to famine in utero, decreasing OGTT AUCs for glucose. This may provide a clue that modulation of the consequences of fetal environment depends on an individual's genetic background.

Overexpression of the Transcription Factor Sp1 Activates the OAS-RNAse L-RIG-I Pathway

PubMed Central

Dupuis-Maurin, Valéryane; Brinza, Lilia; Baguet, Joël; Plantamura, Emilie; Schicklin, Stéphane; Chambion, Solène; Macari, Claire; Tomkowiak, Martine; Deniaud, Emmanuelle; Leverrier, Yann

2015-01-01

Deregulated expression of oncogenes or transcription factors such as specificity protein 1 (Sp1) is observed in many human cancers and plays a role in tumor maintenance. Paradoxically in untransformed cells, Sp1 overexpression induces late apoptosis but the early intrinsic response is poorly characterized. In the present work, we studied increased Sp1 level consequences in untransformed cells and showed that it turns on an early innate immune transcriptome. Sp1 overexpression does not activate known cellular stress pathways such as DNA damage response or endoplasmic reticulum stress, but induces the activation of the OAS-RNase L pathway and the generation of small self-RNAs, leading to the upregulation of genes of the antiviral RIG-I pathway at the transcriptional and translational levels. Finally, Sp1-induced intrinsic innate immune response leads to the production of the chemokine CXCL4 and to the recruitment of inflammatory cells in vitro and in vivo. Altogether our results showed that increased Sp1 level in untransformed cells constitutes a novel danger signal sensed by the OAS-RNase L axis leading to the activation of the RIG-I pathway. These results suggested that the OAS-RNase L-RIG-I pathway may be activated in sterile condition in absence of pathogen. PMID:25738304

SOX2 as a New Regulator of HPV16 Transcription.

PubMed

Martínez-Ramírez, Imelda; Del-Castillo-Falconi, Víctor; Mitre-Aguilar, Irma B; Amador-Molina, Alfredo; Carrillo-García, Adela; Langley, Elizabeth; Zentella-Dehesa, Alejandro; Soto-Reyes, Ernesto; García-Carrancá, Alejandro; Herrera, Luis A; Lizano, Marcela

2017-07-05

Persistent infections with high-risk human papillomavirus (HPV) constitute the main risk factor for cervical cancer development. HPV16 is the most frequent type associated to squamous cell carcinomas (SCC), followed by HPV18. The long control region (LCR) in the HPV genome contains the replication origin and sequences recognized by cellular transcription factors (TFs) controlling viral transcription. Altered expression of E6 and E7 viral oncogenes, modulated by the LCR, causes modifications in cellular pathways such as proliferation, leading to malignant transformation. The aim of this study was to identify specific TFs that could contribute to the modulation of high-risk HPV transcriptional activity, related to the cellular histological origin. We identified sex determining region Y (SRY)-box 2 (SOX2) response elements present in HPV16-LCR. SOX2 binding to the LCR was demonstrated by in vivo and in vitro assays. The overexpression of this TF repressed HPV16-LCR transcriptional activity, as shown through reporter plasmid assays and by the down-regulation of endogenous HPV oncogenes. Site-directed mutagenesis revealed that three putative SOX2 binding sites are involved in the repression of the LCR activity. We propose that SOX2 acts as a transcriptional repressor of HPV16-LCR, decreasing the expression of E6 and E7 oncogenes in a SCC context.

Regulation of zebrafish CYP3A65 transcription by AHR2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, Chin-Teng; Chung, Hsin-Yu; Su, Hsiao-Ting

2013-07-15

CYP3A proteins are the most abundant CYPs in the liver and intestines, and they play a pivotal role in drug metabolism. In mammals, CYP3A genes are induced by various xenobiotics through processes mediated by PXR. We previously identified zebrafish CYP3A65 as a CYP3A ortholog that is constitutively expressed in gastrointestinal tissues, and is upregulated by treatment with dexamethasone, rifampicin or tetrachlorodibenzo-p-dioxin (TCDD). However, the underlying mechanism of TCDD-mediated CYP3A65 transcription is unclear. Here we generated two transgenic zebrafish, Tg(CYP3A65S:EGFP) and Tg(CYP3A65L:EGFP), which contain 2.1 and 5.4 kb 5′ flanking sequences, respectively, of the CYP3A65 gene upstream of EGFP. Both transgenicmore » lines express EGFP in larval gastrointestinal tissues in a pattern similar to that of the endogenous CYP3A65 gene. Moreover, EGFP expression can be significantly induced by TCDD exposure during the larval stage. In addition, EGFP expression can be stimulated by kynurenine, a putative AHR ligand produced during tryptophan metabolism. AHRE elements in the upstream regulatory region of the CYP3A65 gene are indispensible for basal and TCDD-induced transcription. Furthermore, the AHR2 DNA and ligand-binding domains are required to mediate effective CYP3A65 transcription. AHRE sequences are present in the promoters of many teleost CYP3 genes, but not of mammalian CYP3 genes, suggesting that AHR/AHR2-mediated transcription is likely a common regulatory mechanism for teleost CYP3 genes. It may also reflect the different environments that terrestrial and aquatic organisms encounter. - Highlights: • Tg(CYP3A65:EGFP) and CYP3A65 exhibits identical expression pattern. • CYP3A65 can be significantly induced by TCDD or kynurenine. • The AHRE elements are required to mediate CYP3A65 transcription. • The AHR2 DNA and ligand-binding domains are required for CYP3A65 transcription. • AHRE elements are present in many teleost CYP3 genes, but not in

α-Catenin is an inhibitor of transcription

PubMed Central

Daugherty, Rebecca L.; Serebryannyy, Leonid; Yemelyanov, Alex; Flozak, Annette S.; Yu, Hui-Jun; Kosak, Steven T.; deLanerolle, Primal; Gottardi, Cara J.

2014-01-01

α-Catenin (α-cat) is an actin-binding protein required for cell–cell cohesion. Although this adhesive function for α-cat is well appreciated, cells contain a substantial amount of nonjunctional α-cat that may be used for other functions. We show that α-cat is a nuclear protein that can interact with β-catenin (β-cat) and T-cell factor (TCF) and that the nuclear accumulation of α-cat depends on β-cat. Using overexpression, knockdown, and chromatin immunoprecipitation approaches, we show that α-cat attenuates Wnt/β-cat–responsive genes in a manner that is downstream of β-cat/TCF loading on promoters. Both β-cat– and actin-binding domains of α-cat are required to inhibit Wnt signaling. A nuclear-targeted form of α-cat induces the formation of nuclear filamentous actin, whereas cells lacking α-cat show altered nuclear actin properties. Formation of nuclear actin filaments correlates with reduced RNA synthesis and altered chromatin organization. Conversely, nuclear extracts made from cells lacking α-cat show enhanced general transcription in vitro, an activity that can be partially rescued by restoring the C-terminal actin-binding region of α-cat. These data demonstrate that α-cat may limit gene expression by affecting nuclear actin organization. PMID:24706864

Post-transcriptional labeling by using Suzuki-Miyaura cross-coupling generates functional RNA probes.

PubMed

Walunj, Manisha B; Tanpure, Arun A; Srivatsan, Seergazhi G

2018-06-20

Pd-catalyzed C-C bond formation, an important vertebra in the spine of synthetic chemistry, is emerging as a valuable chemoselective transformation for post-synthetic functionalization of biomacromolecules. While methods are available for labeling protein and DNA, development of an analogous procedure to label RNA by cross-coupling reactions remains a major challenge. Herein, we describe a new Pd-mediated RNA oligonucleotide (ON) labeling method that involves post-transcriptional functionalization of iodouridine-labeled RNA transcripts by using Suzuki-Miyaura cross-coupling reaction. 5-Iodouridine triphosphate (IUTP) is efficiently incorporated into RNA ONs at one or more sites by T7 RNA polymerase. Further, using a catalytic system made of Pd(OAc)2 and 2-aminopyrimidine-4,6-diol (ADHP) or dimethylamino-substituted ADHP (DMADHP), we established a modular method to functionalize iodouridine-labeled RNA ONs in the presence of various boronic acid and ester substrates under very mild conditions (37°C and pH 8.5). This method is highly chemoselective, and offers direct access to RNA ONs labeled with commonly used fluorescent and affinity tags and new fluorogenic environment-sensitive nucleoside probes in a ligand-controlled stereoselective fashion. Taken together, this simple approach of generating functional RNA ON probes by Suzuki-Miyaura coupling will be a very important addition to the resources and tools available for analyzing RNA motifs.

Myh7b/miR-499 gene expression is transcriptionally regulated by MRFs and Eos

PubMed Central

Yeung, Fan; Chung, Eunhee; Guess, Martin G.; Bell, Matthew L.; Leinwand, Leslie A.

2012-01-01

The sarcomeric myosin gene, Myh7b, encodes an intronic microRNA, miR-499, which regulates cardiac and skeletal muscle biology, yet little is known about its transcriptional regulation. To identify the transcription factors involved in regulating Myh7b/miR-499 gene expression, we have mapped the transcriptional start sites and identified an upstream 6.2 kb region of the mouse Myh7b gene whose activity mimics the expression pattern of the endogenous Myh7b gene both in vitro and in vivo. Through promoter deletion analysis, we have mapped a distal E-box element and a proximal Ikaros site that are essential for Myh7b promoter activity in muscle cells. We show that the myogenic regulatory factors, MyoD, Myf5 and Myogenin, bind to the E-box, while a lymphoid transcription factor, Ikaros 4 (Eos), binds to the Ikaros motif. Further, we show that through physical interaction, MyoD and Eos form an active transcriptional complex on the chromatin to regulate the expression of the endogenous Myh7b/miR-499 gene in muscle cells. We also provide the first evidence that Eos can regulate expression of additional myosin genes (Myosin 1 and β-Myosin) via the miR-499/Sox6 pathway. Therefore, our results indicate a novel role for Eos in the regulation of the myofiber gene program. PMID:22638570

ATXN1L, CIC, and ETS Transcription Factors Modulate Sensitivity to MAPK Pathway Inhibition.

PubMed

Wang, Belinda; Krall, Elsa Beyer; Aguirre, Andrew James; Kim, Miju; Widlund, Hans Ragnar; Doshi, Mihir Bhavik; Sicinska, Ewa; Sulahian, Rita; Goodale, Amy; Cowley, Glenn Spencer; Piccioni, Federica; Doench, John Gerard; Root, David Edward; Hahn, William Chun

2017-02-07

Intrinsic resistance and RTK-RAS-MAPK pathway reactivation has limited the effectiveness of MEK and RAF inhibitors (MAPKi) in RAS- and RAF-mutant cancers. To identify genes that modulate sensitivity to MAPKi, we performed genome-scale CRISPR-Cas9 loss-of-function screens in two KRAS mutant pancreatic cancer cell lines treated with the MEK1/2 inhibitor trametinib. Loss of CIC, a transcriptional repressor of ETV1, ETV4, and ETV5, promoted survival in the setting of MAPKi in cancer cells derived from several lineages. ATXN1L deletion, which reduces CIC protein, or ectopic expression of ETV1, ETV4, or ETV5 also modulated sensitivity to trametinib. ATXN1L expression inversely correlates with response to MAPKi inhibition in clinical studies. These observations identify the ATXN1L-CIC-ETS transcription factor axis as a mediator of resistance to MAPKi. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Modeling Writing Development: Contribution of Transcription and Self-Regulation to Portuguese Students' Text Generation Quality

ERIC Educational Resources Information Center

Limpo, Teresa; Alves, Rui A.

2013-01-01

Writing is a complex activity that requires transcription and self-regulation. We used multiple-group structural equation modeling to test the contribution of transcription (handwriting and spelling), planning, revision, and self-efficacy to writing quality at 2 developmental points (Grades 4-6 vs. 7-9). In Grades 4-6, the model explained 76% of…

Delamination of neural crest cells requires transient and reversible Wnt inhibition mediated by Dact1/2.

PubMed

Rabadán, M Angeles; Herrera, Antonio; Fanlo, Lucia; Usieto, Susana; Carmona-Fontaine, Carlos; Barriga, Elias H; Mayor, Roberto; Pons, Sebastián; Martí, Elisa

2016-06-15

Delamination of neural crest (NC) cells is a bona fide physiological model of epithelial-to-mesenchymal transition (EMT), a process that is influenced by Wnt/β-catenin signalling. Using two in vivo models, we show that Wnt/β-catenin signalling is transiently inhibited at the time of NC delamination. In attempting to define the mechanism underlying this inhibition, we found that the scaffold proteins Dact1 and Dact2, which are expressed in pre-migratory NC cells, are required for NC delamination in Xenopus and chick embryos, whereas they do not affect the motile properties of migratory NC cells. Dact1/2 inhibit Wnt/β-catenin signalling upstream of the transcriptional activity of T cell factor (TCF), which is required for EMT to proceed. Dact1/2 regulate the subcellular distribution of β-catenin, preventing β-catenin from acting as a transcriptional co-activator to TCF, yet without affecting its stability. Together, these data identify a novel yet important regulatory element that inhibits β-catenin signalling, which then affects NC delamination. © 2016. Published by The Company of Biologists Ltd.

Repression of TFIIH Transcriptional Activity and TFIIH-Associated cdk7 Kinase Activity at Mitosis

PubMed Central

Long, John J.; Leresche, Anne; Kriwacki, Richard W.; Gottesfeld, Joel M.

1998-01-01

Nuclear transcription is repressed when eukaryotic cells enter mitosis. Mitotic repression of transcription of various cellular and viral gene promoters by RNA polymerase II can be reproduced in vitro either with extracts prepared from cells arrested at mitosis with the microtubule polymerization inhibitor nocodazole or with nuclear extracts prepared from asynchronous cells and the mitotic protein kinase cdc2/cyclin B. Purified cdc2/cyclin B kinase is also sufficient to inhibit transcription in reconstituted transcription reactions with biochemically purified and recombinant basal transcription factors and RNA polymerase II. The cyclin-dependent kinase inhibitor p21Waf1/Cip1/Sdi1 can reverse the effect of cdc2/cyclin B kinase, indicating that repression of transcription is due to protein phosphorylation. Transcription rescue and inhibition experiments with each of the basal factors and the polymerase suggest that multiple components of the transcription machinery are inactivated by cdc2/cyclin B kinase. For an activated promoter, targets of repression are TFIID and TFIIH, while for a basal promoter, TFIIH is the major target for mitotic inactivation of transcription. Protein labeling experiments indicate that the p62 and p36 subunits of TFIIH are in vitro substrates for mitotic phosphorylation. Using the carboxy-terminal domain of the large subunit of RNA polymerase II as a test substrate for phosphorylation, the TFIIH-associated kinase, cdk7/cyclin H, is inhibited concomitant with inhibition of transcription activity. Our results suggest that there exist multiple phosphorylation targets for the global shutdown of transcription at mitosis. PMID:9488463

Effects of hepatitis C virus core protein and nonstructural protein 4B on the Wnt/β-catenin pathway.

PubMed

Jiang, Xiao-Hua; Xie, Yu-Tao; Cai, Ya-Ping; Ren, Jing; Ma, Tao

2017-05-25

Hepatitis C virus (HCV) core protein and nonstructural protein 4B (NS4B) are potentially oncogenic. Aberrant activation of the Wnt/β-catenin signaling pathway is closely associated with hepatocarcinogenesis. We investigated the effects of HCV type 1b core protein and NS4B on Wnt/β-catenin signaling in various liver cells, and explored the molecular mechanism underlying HCV-related hepatocarcinogenesis. Compared with the empty vector control, HCV core protein and NS4B demonstrated the following characteristics in the Huh7 cells: significantly enhanced β-catenin/Tcf-dependent transcriptional activity (F = 40.87, P < 0.01); increased nuclear translocation of β-catenin (F = 165.26, P < 0.01); upregulated nuclear β-catenin, cytoplasmic β-catenin, Wnt1, c-myc, and cyclin D1 protein expression (P < 0.01); and promoted proliferation of Huh7 cells (P < 0.01 or P < 0.05). Neither protein enhanced β-catenin/Tcf-dependent transcriptional activity in the LO2 cells (F = 0.65, P > 0.05), but they did significantly enhance Wnt3a-induced β-catenin/Tcf-dependent transcriptional activity (F = 64.25, P < 0.01), and promoted the nuclear translocation of β-catenin (F = 66.54, P < 0.01) and the Wnt3a-induced proliferation of LO2 cells (P < 0.01 or P < 0.05). Moreover, activation of the Wnt/β-catenin signaling pathway was greater with the core protein than with NS4B (P < 0.01 or P < 0.05). HCV core protein and NS4B directly activate the Wnt/β-catenin signaling pathway in Huh7 cells and LO2 cells induced by Wnt3a. These data suggest that HCV core protein and NS4B contribute to HCV-associated hepatocellular carcinogenesis.

c-Myb promotes the survival of CD4+CD8+ double positive thymocytes through up-regulation of Bcl-xL1

PubMed Central

Yuan, Joan; Crittenden, Rowena B.; Bender, Timothy P.

2010-01-01

Mechanisms that regulate the lifespan of CD4+CD8+ double positive (DP) thymocytes help shape the peripheral T cell repertoire. However, the molecular mechanisms that control DP thymocyte survival remain poorly understood. The Myb proto-oncogene encodes a transcription factor required during multiple stages of T cell development. We demonstrate that Myb mRNA expression is up-regulated in the small, pre-selection DP stage during T cell development. Using a conditional deletion mouse model, we demonstrate that Myb deficient DP thymocytes undergo premature apoptosis, resulting in a limited Tcrα repertoire biased towards 5’ Jα segment usage. Premature apoptosis occurs in the small pre-selection DP compartment in an αβTCR independent manner and is a consequence of decreased Bcl-xL expression. Forced Bcl-xL expression is able to rescue survival and re-introduction of c-Myb restores both Bcl-xL expression and the small pre-selection DP compartment. We further demonstrate that thymocytes become dependent on Bcl-xL for survival upon entering the quiescent, small pre-selection DP stage and c-Myb promotes transcription at the Bclx locus via a genetic pathway that is independent of the expression of TCF-1 or RORγt, two transcription factors that induce Bcl-xL expression in T cell development. Thus, Bcl-xL is a novel mediator of c-Myb activity during normal T cell development. PMID:20142358

The X11L/X11{beta}/MINT2 and X11L2/X11{gamma}/MINT3 scaffold proteins shuttle between the nucleus and cytoplasm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sumioka, Akio; Saito, Yuhki; Sakuma, Megumi

2008-03-10

The X11/MINT family proteins are adaptor scaffolding proteins involved in formation of multiprotein complexes, and trafficking and metabolism of membrane proteins such as the beta-amyloid precursor protein. We found that a significant portion of X11L and X11L2 are recovered in nuclear fraction of mouse brain homogenates. EGFP-X11s were not detected in the nucleus of N2a neuroblastoma cells; however, administration of leptomycin B (LMB) induced substantial nuclear accumulation of EGFP-X11L and EGFP-X11L2, while EGFP-X11 showed little accumulation. Fluorescence loss in photobleaching (FLIP) analysis indicated that EGFP-X11L2 and EGFP-X11L are shuttled between the cytoplasm and nucleus, the former more effectively than themore » latter. We identified a nuclear export signal (NES) in the N-terminus of X11L2, mutation of which induces nuclear accumulation of EGFP-X11L2 in the absence of LMB. X11L2 fused to the Gal4 DNA binding domain (DBD) showed transcriptional activity, suggesting that X11L2 could function as a transcriptional activator if tethered near a promoter. Interestingly, attenuation of the nucleo-cytoplasmic shuttling of GAL4-DBD-X11L2 by mutating the NES or attaching the SV40 nuclear localization signal significantly decreased the apparent transcriptional activity. Our observations suggest that X11L2 functions in the nucleus by a mechanism distinct from conventional transactivators.« less

Perlman syndrome nuclease DIS3L2 controls cytoplasmic non-coding RNAs and provides surveillance pathway for maturing snRNAs

PubMed Central

Łabno, Anna; Warkocki, Zbigniew; Kuliński, Tomasz; Krawczyk, Paweł Szczepan; Bijata, Krystian; Tomecki, Rafał; Dziembowski, Andrzej

2016-01-01

The exosome-independent exoribonuclease DIS3L2 is mutated in Perlman syndrome. Here, we used extensive global transcriptomic and targeted biochemical analyses to identify novel DIS3L2 substrates in human cells. We show that DIS3L2 regulates pol II transcripts, comprising selected canonical and histone-coding mRNAs, and a novel FTL_short RNA from the ferritin mRNA 5′ UTR. Importantly, DIS3L2 contributes to surveillance of maturing snRNAs during their cytoplasmic processing. Among pol III transcripts, DIS3L2 particularly targets vault and Y RNAs and an Alu-like element BC200 RNA, but not Alu repeats, which are removed by exosome-associated DIS3. Using 3′ RACE-Seq, we demonstrate that all novel DIS3L2 substrates are uridylated in vivo by TUT4/TUT7 poly(U) polymerases. Uridylation-dependent DIS3L2-mediated decay can be recapitulated in vitro, thus reinforcing the tight cooperation between DIS3L2 and TUTases. Together these results indicate that catalytically inactive DIS3L2, characteristic of Perlman syndrome, can lead to deregulation of its target RNAs to disturb transcriptome homeostasis. PMID:27431325

Peach MYB7 activates transcription of the proanthocyanidin pathway gene encoding leucoanthocyanidin reductase, but not anthocyanidin reductase

PubMed Central

Zhou, Hui; Lin-Wang, Kui; Liao, Liao; Gu, Chao; Lu, Ziqi; Allan, Andrew C.; Han, Yuepeng

2015-01-01

Proanthocyanidins (PAs) are a group of natural phenolic compounds that have a great effect on both flavor and nutritious value of fruit. It has been shown that PA synthesis is regulated by R2R3-MYB transcription factors (TFs) via activation of PA-specific pathway genes encoding leucoanthocyanidin reductase and anthocyanidin reductase. Here, we report the isolation and characterization of a MYB gene designated PpMYB7 in peach. The peach PpMYB7 represents a new group of R2R3-MYB genes regulating PA synthesis in plants. It is able to activate transcription of PpLAR1 but not PpANR, and has a broader selection of potential bHLH partners compared with PpMYBPA1. Transcription of PpMYB7 can be activated by the peach basic leucine-zipper 5 TF (PpbZIP5) via response to ABA. Our study suggests a transcriptional network regulating PA synthesis in peach, with the results aiding the understanding of the functional divergence between R2R3-MYB TFs in plants. PMID:26579158

Genetic Variant in the IGF2BP2 Gene May Interact With Fetal Malnutrition to Affect Glucose Metabolism

PubMed Central

van Hoek, Mandy; Langendonk, Janneke G.; de Rooij, Susanne R.; Sijbrands, Eric J.G.; Roseboom, Tessa J.

2009-01-01

OBJECTIVE Fetal malnutrition may predispose to type 2 diabetes through gene programming and developmental changes. Previous studies showed that these effects may be modulated by genetic variation. Genome-wide association studies discovered and replicated a number of type 2 diabetes–associated genes. We investigated the effects of such well-studied polymorphisms and their interactions with fetal malnutrition on type 2 diabetes risk and related phenotypes in the Dutch Famine Birth Cohort. RESEARCH DESIGN AND METHODS The rs7754840 (CDKAL1), rs10811661 (CDKN2AB), rs1111875 (HHEX), rs4402960 (IGF2BP2), rs5219 (KCNJ11), rs13266634 (SLC30A8), and rs7903146 (TCF7L2) polymorphisms were genotyped in 772 participants of the Dutch Famine Birth Cohort Study (n = 328 exposed, n = 444 unexposed). Logistic and linear regression models served to analyze their interactions with prenatal exposure to famine on type 2 diabetes, impaired glucose tolerance (IGT), and area under the curves (AUCs) for glucose and insulin during oral glucose tolerance testing (OGTT). RESULTS In the total population, the TCF7L2 and IGF2BP2 variants most strongly associated with increased risk for type 2 diabetes/IGT and increased AUC for glucose, while the CDKAL1 polymorphism associated with decreased AUC for insulin. The IGF2BP2 polymorphism showed an interaction with prenatal exposure to famine on AUC for glucose (β = −9.2 [95% CI −16.2 to −2.1], P = 0.009). CONCLUSIONS The IGF2BP2 variant showed a nominal interaction with exposure to famine in utero, decreasing OGTT AUCs for glucose. This may provide a clue that modulation of the consequences of fetal environment depends on an individual's genetic background. PMID:19258437

NREL's Energy Storage and REopt Teams Awarded $525k from TCF to Study

Science.gov Websites

Commercial Viability of Optimal, Reliable Building-Integrated Energy Storage | News | NREL NREL's Energy Storage and REopt Teams Awarded $525k from TCF to Study Commercial Viability of Optimal Study Commercial Viability of Optimal, Reliable Building-Integrated Energy Storage November 14, 2017

Post-transcriptional control of PD-L1 expression by 17β-estradiol via PI3K/Akt signaling pathway in ERα-positive cancer cell lines

PubMed Central

Yang, Lingyun; Huang, Feng; Mei, Jiandong; Wang, Xun; Zhang, Qiuyang; Wang, Hongjing; Xi, Mingrong; You, Zongbing

2016-01-01

Objective Estrogen is a well-known oncogenic driver in endometrial and breast cancers. Programmed cell death protein 1 (PD-1) and its ligands PD-L1 and PD-L2 have been shown to mediate immune evasion of the tumor cells. The purpose of the present study was to assess the effects of estrogen on PD-L1 and PD-L2 expression in endometrial and breast cancer cell lines. Methods 17β-estradiol (E2) -induced expression of PD-L1 and PD-L2 and possible signaling pathway were investigated in endometrial and breast cancer cells. Co-culture of T cells and cancer cells with E2 stimulation was performed to assess the functions of T cells. Results We found that 17β-estradiol (E2) increased expression of PD-L1, but not PD-L2 protein via activation of phosphoinositide 3-kinase (PI3K)/Akt pathway in Ishikawa and MCF-7 cells. PI3K and Akt inhibitors could block E2's effects. E2 did not increase PD-L1 mRNA transcription, but stabilized PD-L1 mRNA. E2's effects were only observed in estrogen receptor α (ERα) -positive Ishikawa and MCF-7 cells, but not in ERα-negative MDA-MB-231 cells. Co-culture of Ishikawa or MCF-7 cells with T cells inhibited expression of interferon-γ and interleukin-2 and increased Bim expression in the presence of E2. Conclusion This study provides the first evidence that estrogen up-regulates PD-L1 protein expression in ERα-positive endometrial and breast cancer cells to suppress immune functions of T cells in the tumor microenvironment, demonstrating a new mechanism of how estrogen drives cancer progression. PMID:27870715

Microarray-based identification of differentially expressed genes in extramammary Paget’s disease

PubMed Central

Lin, Jin-Ran; Liang, Jun; Zhang, Qiao-An; Huang, Qiong; Wang, Shang-Shang; Qin, Hai-Hong; Chen, Lian-Jun; Xu, Jin-Hua

2015-01-01

Extramammary Paget’s disease (EMPD) is a rare cutaneous malignancy accounting for approximately 1-2% of vulvar cancers. The rarity of this disease has caused difficulties in characterization and the molecular mechanism underlying EMPD development remains largely unclear. Here we used microarray analysis to identify differentially expressed genes in EMPD of the scrotum comparing with normal epithelium from healthy donors. Agilent single-channel microarray was used to compare the gene expression between 6 EMPD specimens and 6 normal scrotum epithelium samples. A total of 799 up-regulated genes and 723 down-regulated genes were identified in EMPD tissues. Real-time PCR was conducted to verify the differential expression of some representative genes, including ERBB4, TCF3, PAPSS2, PIK3R3, PRLR, SULT1A1, TCF7L1, and CREB3L4. Generally, the real-time PCR results were consistent with microarray data, and the expression of ERBB4, PRLR, TCF3, PIK3R3, SULT1A1, and TCF7L1 was significantly overexpressed in EMPD (P<0.05). Moreover, the overexpression of PRLR in EMPD, a receptor for the anterior pituitary hormone prolactin (PRL), was confirmed by immunohistochemistry. These data demonstrate that the differentially expressed genes from the microarray-based identification are tightly associated with EMPD occurrence. PMID:26221264

The structural changes of T7 RNA polymerase from transcription initiation to elongation

PubMed Central

Steitz, Thomas A

2010-01-01

Summary The structures of T7 RNA polymerase (T7 RNAP) captured in the initiation and elongation phases of transcription, as well as an intermediate stage provide insights into how this RNA polymerase protein can initiate RNA synthesis and synthesize 7 to 10 nucleotides of RNA while remaining bound to the DNA promoter site. Recently, the structures of T7 RNAP bound to it promoter DNA along with either a 7 nucleotide or 8 nucleotide transcript show an elongated product site resulting from a 40° or 45° rotation of the promoter and domain that binds it. The different functional properties of the initiation and elongation phases of transcription are illuminated from structures of the initiation and elongation complexes. Structural insights into the translocation of the product transcript of RNAP, its separation of the downstream duplex DNA and its removal of the transcript from the heteroduplex are provided by the structures of several states of nucleotide incorporation. A conformational change in the “fingers” domain that results from the binding or dissociation of incoming NTP or PPi appears to be associated with the state of translocation of T7 RNAP. PMID:19811903

Activation of Wnt signaling pathway by human papillomavirus E6 and E7 oncogenes in HPV16-positive oropharyngeal squamous carcinoma cells.

PubMed

Rampias, Theodore; Boutati, Eleni; Pectasides, Eirini; Sasaki, Clarence; Kountourakis, Panteleimon; Weinberger, Paul; Psyrri, Amanda

2010-03-01

We sought to determine the role of human papillomavirus (HPV) E6 and E7 oncogenes in nuclear beta-catenin accumulation, a hallmark of activated canonical Wnt signaling pathway. We used HPV16-positive oropharyngeal cancer cell lines 147T and 090, HPV-negative cell line 040T, and cervical cell lines SiHa (bearing integrated HPV16) and HeLa (bearing integrated HPV18) to measure the cytoplasmic and nuclear beta-catenin levels and the beta-catenin/Tcf transcriptional activity before and after E6/E7 gene silencing. Repression of HPV E6 and E7 genes induced a substantial reduction in nuclear beta-catenin levels. Luciferase assay showed that transcriptional activation of Tcf promoter by beta-catenin was lower after silencing. The protein levels of beta-catenin are tightly regulated by the ubiquitin/proteasome system. We therefore performed expression analysis of regulators of beta-catenin degradation and nuclear transport and showed that seven in absentia homologue (Siah-1) mRNA and protein levels were substantially upregulated after E6/E7 repression. Siah-1 protein promotes the degradation of beta-catenin through the ubiquitin/proteasome system. To determine whether Siah-1 is important for the proteasomal degradation of beta-catenin in HPV16-positive oropharyngeal cancer cells, we introduced a Siah-1 expression vector into 147T and 090 cells and found substantial reduction of endogenous beta-catenin in these cells. Thus, E6 and E7 are involved in beta-catenin nuclear accumulation and activation of Wnt signaling in HPV-induced cancers. In addition, we show the significance of the endogenous Siah-1-dependent ubiquitin/proteasome pathway for beta-catenin degradation and its regulation by E6/E7 viral oncoproteins in HPV16-positive oropharyngeal cancer cells.

CREBBP mutations in relapsed acute lymphoblastic leukaemia

PubMed Central

Mullighan, Charles G.; Zhang, Jinghui; Kasper, Lawryn H.; Lerach, Stephanie; Payne-Turner, Debbie; Phillips, Letha A.; Heatley, Sue L.; Holmfeldt, Linda; Collins-Underwood, J. Racquel; Ma, Jing; Buetow, Kenneth H.; Pui, Ching-Hon; Baker, Sharyn D.; Brindle, Paul K.; Downing, James R.

2010-01-01

Relapsed acute lymphoblastic leukaemia (ALL) is a leading cause of death due to disease in young people, but the biologic determinants of treatment failure remain poorly understood. Recent genome-wide profiling of structural DNA alterations in ALL have identified multiple submicroscopic somatic mutations targeting key cellular pathways1,2, and have demonstrated substantial evolution in genetic alterations from diagnosis to relapse3. However, detailed analysis of sequence mutations in ALL has not been performed. To identify novel mutations in relapsed ALL, we resequenced 300 genes in matched diagnosis and relapse samples from 23 patients with ALL. This identified 52 somatic non-synonymous mutations in 32 genes, many of which were novel, including the transcriptional coactivators CREBBP and NCOR1, the transcription factors ERG, SPI1, TCF4 and TCF7L2, components of the Ras signalling pathway, histone genes, genes involved in histone modification (CREBBP and CTCF), and genes previously shown to be targets of recurring DNA copy number alteration in ALL. Analysis of an extended cohort of 71 diagnosis-relapse cases and 270 acute leukaemia cases that did not relapse found that 18.3% of relapse cases had sequence or deletion mutations of CREBBP, which encodes the transcriptional coactivator and histone acetyltransferase (HAT) CREB-binding protein (CBP)4. The mutations were either present at diagnosis or acquired at relapse, and resulted in truncated alleles or deleterious substitutions in conserved residues of the HAT domain. Functionally, the mutations impaired histone acetylation and transcriptional regulation of CREBBP targets, including glucocorticoid responsive genes. Several mutations acquired at relapse were detected in subclones at diagnosis, suggesting that the mutations may confer resistance to therapy. These results extend the landscape of genetic alterations in leukaemia, and identify mutations targeting transcriptional and epigenetic regulation as a mechanism

CRISPR/Cas9 and active genetics-based trans-species replacement of the endogenous Drosophila kni-L2 CRM reveals unexpected complexity.

PubMed

Xu, Xiang-Ru Shannon; Gantz, Valentino Matteo; Siomava, Natalia; Bier, Ethan

2017-12-23

The knirps ( kni ) locus encodes transcription factors required for induction of the L2 wing vein in Drosophila . Here, we employ diverse CRISPR/Cas9 genome editing tools to generate a series of targeted lesions within the endogenous cis-regulatory module (CRM) required for kni expression in the L2 vein primordium. Phenotypic analysis of these ' in locus ' mutations based on both expression of Kni protein and adult wing phenotypes, reveals novel unexpected features of L2-CRM function including evidence for a chromosome pairing-dependent process that promotes transcription. We also demonstrate that self-propagating active genetic elements (CopyCat elements) can efficiently delete and replace the L2-CRM with orthologous sequences from other divergent fly species. Wing vein phenotypes resulting from these trans-species enhancer replacements parallel features of the respective donor fly species. This highly sensitive phenotypic readout of enhancer function in a native genomic context reveals novel features of CRM function undetected by traditional reporter gene analysis. © 2017, Xu et al.

CRISPR/Cas9 and active genetics-based trans-species replacement of the endogenous Drosophila kni-L2 CRM reveals unexpected complexity

PubMed Central

Siomava, Natalia

2017-01-01

The knirps (kni) locus encodes transcription factors required for induction of the L2 wing vein in Drosophila. Here, we employ diverse CRISPR/Cas9 genome editing tools to generate a series of targeted lesions within the endogenous cis-regulatory module (CRM) required for kni expression in the L2 vein primordium. Phenotypic analysis of these ‘in locus’ mutations based on both expression of Kni protein and adult wing phenotypes, reveals novel unexpected features of L2-CRM function including evidence for a chromosome pairing-dependent process that promotes transcription. We also demonstrate that self-propagating active genetic elements (CopyCat elements) can efficiently delete and replace the L2-CRM with orthologous sequences from other divergent fly species. Wing vein phenotypes resulting from these trans-species enhancer replacements parallel features of the respective donor fly species. This highly sensitive phenotypic readout of enhancer function in a native genomic context reveals novel features of CRM function undetected by traditional reporter gene analysis. PMID:29274230

trans-Resveratrol Protects Ischemic PC12 Cells by Inhibiting the Hypoxia Associated Transcription Factors and Increasing the Levels of Antioxidant Defense Enzymes

PubMed Central

2012-01-01

An in vitro model of ischemic cerebral stroke [oxygen-glucose deprivation (OGD) for 6 h followed by 24 h reoxygenation (R)] with PC12 cells increases Ca2+ influx by upregulating native L-type Ca2+ channels and reactive oxygen species (ROS) generation. This reactive oxygen species generation and increase in intracellular Ca2+ triggers the expression of hypoxic homeostasis transcription factors such as hypoxia induced factor-1 alpha (HIF-1α), Cav-beta 3 (Cav β3), signal transducer and activator of transcription 3 (STAT3), heat shock protein 27 (hsp-27), and cationic channel transient receptor potential melastatin 7 (TRPM7). OGD insulted PC12 cells were subjected to biologically safe doses (5, 10, and 25 μM) of trans-resveratrol in three different treatment groups: 24 h prior to OGD (pre-treatment); 24 h post OGD (post-treatment); and from 24 h before OGD to end of reoxygenation period (whole-treatment). Here, we demonstrated that OGD-R-induced neuronal injury/death is by reactive oxygen species generation, increase in intracellular calcium levels, and decrease in antioxidant defense enzymes. trans-Resveratrol increases the viability of OGD-R insulted PC12 cells, which was assessed by using MTT, NRU, and LDH release assay. In addition, trans-resveratrol significantly decreases reactive oxygen species generation, intracellular Ca2+ levels, and hypoxia associated transcription factors and also increases the level of antioxidant defense enzymes. Our data shows that the whole-treatment group of trans-resveratrol is most efficient in decreasing hypoxia induced cell death through its antioxidant properties. PMID:23421680

An MSC2 Promoter-lacZ Fusion Gene Reveals Zinc-Responsive Changes in Sites of Transcription Initiation That Occur across the Yeast Genome

PubMed Central

Wu, Yi-Hsuan; Taggart, Janet; Song, Pamela Xiyao; MacDiarmid, Colin; Eide, David J.

2016-01-01

The Msc2 and Zrg17 proteins of Saccharomyces cerevisiae form a complex to transport zinc into the endoplasmic reticulum. ZRG17 is transcriptionally induced in zinc-limited cells by the Zap1 transcription factor. In this report, we show that MSC2 mRNA also increases (~1.5 fold) in zinc-limited cells. The MSC2 gene has two in-frame ATG codons at its 5’ end, ATG1 and ATG2; ATG2 is the predicted initiation codon. When the MSC2 promoter was fused at ATG2 to the lacZ gene, we found that unlike the chromosomal gene this reporter showed a 4-fold decrease in lacZ mRNA in zinc-limited cells. Surprisingly, β-galactosidase activity generated by this fusion gene increased ~7 fold during zinc deficiency suggesting the influence of post-transcriptional factors. Transcription of MSC2ATG2-lacZ was found to start upstream of ATG1 in zinc-replete cells. In zinc-limited cells, transcription initiation shifted to sites just upstream of ATG2. From the results of mutational and polysome profile analyses, we propose the following explanation for these effects. In zinc-replete cells, MSC2ATG2-lacZ mRNA with long 5’ UTRs fold into secondary structures that inhibit translation. In zinc-limited cells, transcripts with shorter unstructured 5’ UTRs are generated that are more efficiently translated. Surprisingly, chromosomal MSC2 did not show start site shifts in response to zinc status and only shorter 5’ UTRs were observed. However, the shifts that occur in the MSC2ATG2-lacZ construct led us to identify significant transcription start site changes affecting the expression of ~3% of all genes. Therefore, zinc status can profoundly alter transcription initiation across the yeast genome. PMID:27657924

Independent replication of mitochondrial genes supports the transcriptional program in developing fiber cells of cotton (Gossypium hirsutum L.).

PubMed

Thyssen, Gregory N; Song, Xianliang; Naoumkina, Marina; Kim, Hee-Jin; Fang, David D

2014-07-01

The mitochondrial genomes of flowering plants exist both as a "master circle" chromosome and as numerous subgenomic sublimons that are generated by intramolecular recombination. Differential stability or replication of these sublimons allows individual mitochondrial gene copy numbers to vary independently between different cell types and developmental stages. Our objective was to determine the relationship between mitochondrial gene copy number and transcript abundance in the elongating fiber cells of Upland cotton (Gossypium hirsutum L.). We compared RNA and DNA from cotton fiber cells at five developmental time points from early elongation through secondary cell wall thickening from the Ligon-lintless 2 (Li2) short fiber mutant and its wild type near isogenic line (NIL) DP5690. Mitochondrial gene copy number decreased from 3 to 8-DPA in the developing cotton fiber cells while transcript levels remained low. As secondary cell wall biosynthesis began in developing fibers, the expression levels and copy numbers of mitochondrial genes involved in energy production and respiration were up-regulated in wild type cotton DP5690. However, the short fiber mutant Li2, failed to increase expression of these genes, which include three subunits of ATP synthase, atp1, atp8 and atp9 and two cytochrome genes cox1 and cob. At the same time, Li2 failed to increase the copy numbers of these highly expressed genes. Surprisingly, we found that when mitochondrial genes were highly transcribed, they also had very high copy numbers. This observation suggests that in developing cotton fibers, increased mitochondrial sublimon replication may support increases in gene transcription. Published by Elsevier B.V.

The full transcription map of mouse papillomavirus type 1 (MmuPV1) in mouse wart tissues

PubMed Central

Kim, Bong-Hyun; Gotte, Deanna; Chen, Xiongfong; Cam, Maggie; Lambert, Paul F.

2017-01-01

Mouse papillomavirus type 1 (MmuPV1) provides, for the first time, the opportunity to study infection and pathogenesis of papillomaviruses in the context of laboratory mice. In this report, we define the transcriptome of MmuPV1 genome present in papillomas arising in experimentally infected mice using a combination of RNA-seq, PacBio Iso-seq, 5’ RACE, 3’ RACE, primer-walking RT-PCR, RNase protection, Northern blot and in situ hybridization analyses. We demonstrate that the MmuPV1 genome is transcribed unidirectionally from five major promoters (P) or transcription start sites (TSS) and polyadenylates its transcripts at two major polyadenylation (pA) sites. We designate the P7503, P360 and P859 as “early” promoters because they give rise to transcripts mostly utilizing the polyadenylation signal at nt 3844 and therefore can only encode early genes, and P7107 and P533 as “late” promoters because they give rise to transcripts utilizing polyadenylation signals at either nt 3844 or nt 7047, the latter being able to encode late, capsid proteins. MmuPV1 genome contains five splice donor sites and three acceptor sites that produce thirty-six RNA isoforms deduced to express seven predicted early gene products (E6, E7, E1, E1^M1, E1^M2, E2 and E8^E2) and three predicted late gene products (E1^E4, L2 and L1). The majority of the viral early transcripts are spliced once from nt 757 to 3139, while viral late transcripts, which are predicted to encode L1, are spliced twice, first from nt 7243 to either nt 3139 (P7107) or nt 757 to 3139 (P533) and second from nt 3431 to nt 5372. Thirteen of these viral transcripts were detectable by Northern blot analysis, with the P533-derived late E1^E4 transcripts being the most abundant. The late transcripts could be detected in highly differentiated keratinocytes of MmuPV1-infected tissues as early as ten days after MmuPV1 inoculation and correlated with detection of L1 protein and viral DNA amplification. In mature warts

Immunogencity of HSA-L7/L12 (Brucella abortus ribosomal protein) in an animal model.

PubMed

Pakzad, Iraj; Rezaee, Abbas; Rasaee, Mohammad Javad; Tabbaraee, Bahman; Delpisheh, Ali

2009-03-01

The immunogenic Brucella abortus ribosomal protein L7/L12 is a promising candidate antigen for the development of subunit vaccines against brucellosis. This study was aimed to evaluate the protection of recombinant Human Serum Albumin (HAS)-L7/L12 fusion protein in Balb/c mice. The amplified L7/L12 gene was cloned in pYHSA5 vector, pYHSA5-L7/L12 construct was transformed in Saccharomyces cerevisiae and the expressed protein from supernatant was purified by affinity chromatography. Balb/c mice were immunized in five groups by tHSA-L7/L12 fusion protein (group 1), Brucella abortus S19 (group 2), HSA (group 3), recombinant L7/L12 (group 4), PBS (group 5). ELISA to detect antibody production, LTT test to assess antigen specific lymphocyte response were conducted prior to virulent B. abortus strain 544 challenge two weeks after the last injection. Bacterial counts from spleens of immunized mice were done four weeks after challenge. In ELISA tests, the specific antibodies exhibited a dominance of immunoglobulin IgG1 over IgG2a. In addition, the tHSA-L7/L12 fusion protein and L7/L12 elicited a strong T-cell proliferative response upon restimulation in vitro with recombinant tHSA-L7/L12 and L7/L12, suggesting the induction of a cellular immunity response in vivo. However, there was no significant difference in proliferative response of L7/L12 and tHSA-L7/L12 fusion protein (p>0.05). The L7/L12 and tHSA-L7/L12 fusion protein vaccines could also induce significant protection against challenge with the virulent strain B. abortus 544 in Balb/c mice (p< or =0.05). The tHSA-L7/L12 fusion protein, similar to L7/L12 has the ability to induce antigen specific lymphocyte proliferation, stimulate humoral immunity and engender protection.

Glycogen synthase kinase-3 inhibitors suppress the AR-V7-mediated transcription and selectively inhibit cell growth in AR-V7-positive prostate cancer cells.

PubMed

Nakata, Daisuke; Koyama, Ryokichi; Nakayama, Kazuhide; Kitazawa, Satoshi; Watanabe, Tatsuya; Hara, Takahito

2017-06-01

Recent evidence suggests that androgen receptor (AR) splice variants, including AR-V7, play a pivotal role in resistance to androgen blockade in prostate cancer treatment. The development of new therapeutic agents that can suppress the transcriptional activities of AR splice variants has been anticipated as the next generation treatment of castration-resistant prostate cancer. High-throughput screening of AR-V7 signaling inhibitors was performed using an AR-V7 reporter system. The effects of a glycogen synthase kinase-3 (GSK3) inhibitor, LY-2090314, on endogenous AR-V7 signaling were evaluated in an AR-V7-positive cell line, JDCaP-hr, by quantitative reverse transcription polymerase chain reaction. The relationship between AR-V7 signaling and β-catenin signaling was assessed using RNA interference. The effect of LY-2090314 on cell growth in various prostate cancer cell lines was also evaluated. We identified GSK3 inhibitors as transcriptional suppressors of AR-V7 using a high-throughput screen with an AR-V7 reporter system. LY-2090314 suppressed the reporter activity and endogenous AR-V7 activity in JDCaP-hr cells. Because silencing of β-catenin partly rescued the suppression, it was evident that the suppression was mediated, at least partially, via the activation of β-catenin signaling. AR-V7 signaling and β-catenin signaling reciprocally regulate each other in JDCaP-hr cells, and therefore, GSK3 inhibition can repress AR-V7 transcriptional activity by accumulating intracellular β-catenin. Notably, LY-2090314 selectively inhibited the growth of AR-V7-positive prostate cancer cells in vitro. Our findings demonstrate the potential of GSK3 inhibitors in treating advanced prostate cancer driven by AR splice variants. In vivo evaluation of AR splice variant-positive prostate cancer models will help illustrate the overall significance of GSK3 inhibitors in treating prostate cancer. © 2017 Wiley Periodicals, Inc.

Genome-scale transcriptional analyses of first-generation interspecific sunflower hybrids reveals broad regulatory compatibility

PubMed Central

2013-01-01

Background Interspecific hybridization creates individuals harboring diverged genomes. The interaction of these genomes can generate successful evolutionary novelty or disadvantageous genomic conflict. Annual sunflowers Helianthus annuus and H. petiolaris have a rich history of hybridization in natural populations. Although first-generation hybrids generally have low fertility, hybrid swarms that include later generation and fully fertile backcross plants have been identified, as well as at least three independently-originated stable hybrid taxa. We examine patterns of transcript accumulation in the earliest stages of hybridization of these species via analyses of transcriptome sequences from laboratory-derived F1 offspring of an inbred H. annuus cultivar and a wild H. petiolaris accession. Results While nearly 14% of the reference transcriptome showed significant accumulation differences between parental accessions, total F1 transcript levels showed little evidence of dominance, as midparent transcript levels were highly predictive of transcript accumulation in F1 plants. Allelic bias in F1 transcript accumulation was detected in 20% of transcripts containing sufficient polymorphism to distinguish parental alleles; however the magnitude of these biases were generally smaller than differences among parental accessions. Conclusions While analyses of allelic bias suggest that cis regulatory differences between H. annuus and H. petiolaris are common, their effect on transcript levels may be more subtle than trans-acting regulatory differences. Overall, these analyses found little evidence of regulatory incompatibility or dominance interactions between parental genomes within F1 hybrid individuals, although it is unclear whether this is a legacy or an enabler of introgression between species. PMID:23701699

hnRNP L binds to CA repeats in the 3'UTR of bcl-2 mRNA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Dong-Hyoung; Lim, Mi-Hyun; Youn, Dong-Ye

We previously reported that the CA-repeat sequence in the 3'-untranslated region (3'UTR) of bcl-2 mRNA is involved in the decay of bcl-2 mRNA. However, the trans-acting factor for the CA element in bcl-2 mRNA remains unidentified. The heterogeneous nuclear ribonucleoprotein L (hnRNP L), an intron splicing factor, has been reported to bind to CA repeats and CA clusters in the 3'UTR of several genes. We reported herein that the CA repeats of bcl-2 mRNA have the potential to form a distinct ribonuclear protein complex in cytoplasmic extracts of MCF-7 cells, as evidenced by RNA electrophoretic mobility shift assays (REMSA). Amore » super-shift assay using the hnRNP L antibody completely shifted the complex. Immunoprecipitation with the hnRNP L antibody and MCF-7 cells followed by RT-PCR revealed that hnRNP L interacts with endogenous bcl-2 mRNA in vivo. Furthermore, the suppression of hnRNP L in MCF-7 cells by the transfection of siRNA for hnRNP L resulted in a delay in the degradation of RNA transcripts including CA repeats of bcl-2 mRNA in vitro, suggesting that the interaction between hnRNPL and CA repeats of bcl-2 mRNA participates in destabilizing bcl-2 mRNA.« less

Transcriptional Networks Controlled by NKX2-1 in the Development of Forebrain GABAergic Neurons

DOE PAGES

Sandberg, Magnus; Flandin, Pierre; Silberberg, Shanni; ...

2016-09-21

The embryonic basal ganglia generates multiple projection neurons and interneuron subtypes from distinct progenitor domains. Combinatorial interactions of transcription factors and chromatin are thought to regulate gene expression. In the medial ganglionic eminence, the NKX2-1 transcription factor controls regional identity and, with LHX6, is necessary to specify pallidal projection neurons and forebrain interneurons. Here, we dissected the molecular functions of NKX2-1 by defining its chromosomal binding, regulation of gene expression, and epigenetic state. NKX2-1 binding at distal regulatory elements led to a repressed epigenetic state and transcriptional repression in the ventricular zone. Conversely, NKX2-1 is required to establish a permissivemore » chromatin state and transcriptional activation in the sub-ventricular and mantle zones. Moreover, combinatorial binding of NKX2-1 and LHX6 promotes transcriptionally permissive chromatin and activates genes expressed in cortical migrating interneurons. Our integrated approach gives a foundation for elucidating transcriptional networks guiding the development of the MGE and its descendants.« less

Role of an RNase III Binding Site in Transcription Termination at λ nutL by HK022 Nun Protein

PubMed Central

Washburn, Robert S.; Court, Donald L.; Gottesman, Max E.

2006-01-01

The phage HK022 Nun protein excludes phage λ by binding nascent λ pL and pR transcripts at nutL and nutR, respectively, and inducing transcription termination just downstream of these sites. Termination is more efficient at nutL than at nutR. One difference between nutL and nutR is the presence of RNase III processing sites (rIII) located immediately promoter distal to λ nutL. We found that deletion of rIII dramatically reduced Nun transcription arrest in vitro but had little effect on termination in vivo. However, consistent with the in vitro results, overexpression of a transcript carrying nutL and rIII efficiently titrated Nun, allowing λ to grow on a strain that expressed Nun, whereas a transcript carrying only nutL or nutL-rIII with nucleotides 97 to 141 deleted was ineffective. Rnc70, an RNase III mutant that binds but does not cleave rIII, also prevented Nun-mediated λ exclusion. We propose that rIII enhances the on-rate of Nun at nutL, stimulating Nun-mediated arrest in vitro. We have shown that a specific element in rIII, i.e., box C (G89GUGUGUG), strongly enhances arrest on rIII+ templates. Nun-rIII interactions do not stimulate Nun termination in vivo, presumably because formation of the Nun-nutL complex is normally not rate-limiting in the cell. In contrast to Nun, N is not occluded by Rnc70 and is not efficiently titrated by a nutL-rIII transcript. PMID:16980485

The generation and accumulation of interstitial atoms and vacancies in alloys with L1{sub 2} superstructure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pantyukhova, Olga, E-mail: Pantyukhova@list.ru; Starenchenko, Vladimir, E-mail: star@tsuab.ru; Starenchenko, Svetlana, E-mail: sve-starenchenko@yandex.ru

2016-01-15

The dependences of the point defect concentration (interstitial atoms and vacancies) on the deformation degree were calculated for the L1{sub 2} alloys with the high and low antiphase boundaries (APB) energy in terms of the mathematical model of the work and thermal strengthening of the alloys with the L1{sub 2} structure; the concentration of the point defects generated and annihilated in the process of deformation was estimated. It was found that the main part of the point defects generating during plastic deformation annihilates, the residual density of the deformation point defects does not exceed 10{sup −5}.

Intronic L1 Retrotransposons and Nested Genes Cause Transcriptional Interference by Inducing Intron Retention, Exonization and Cryptic Polyadenylation

PubMed Central

Kaer, Kristel; Branovets, Jelena; Hallikma, Anni; Nigumann, Pilvi; Speek, Mart

2011-01-01

Background Transcriptional interference has been recently recognized as an unexpectedly complex and mostly negative regulation of genes. Despite a relatively few studies that emerged in recent years, it has been demonstrated that a readthrough transcription derived from one gene can influence the transcription of another overlapping or nested gene. However, the molecular effects resulting from this interaction are largely unknown. Methodology/Principal Findings Using in silico chromosome walking, we searched for prematurely terminated transcripts bearing signatures of intron retention or exonization of intronic sequence at their 3′ ends upstream to human L1 retrotransposons, protein-coding and noncoding nested genes. We demonstrate that transcriptional interference induced by intronic L1s (or other repeated DNAs) and nested genes could be characterized by intron retention, forced exonization and cryptic polyadenylation. These molecular effects were revealed from the analysis of endogenous transcripts derived from different cell lines and tissues and confirmed by the expression of three minigenes in cell culture. While intron retention and exonization were comparably observed in introns upstream to L1s, forced exonization was preferentially detected in nested genes. Transcriptional interference induced by L1 or nested genes was dependent on the presence or absence of cryptic splice sites, affected the inclusion or exclusion of the upstream exon and the use of cryptic polyadenylation signals. Conclusions/Significance Our results suggest that transcriptional interference induced by intronic L1s and nested genes could influence the transcription of the large number of genes in normal as well as in tumor tissues. Therefore, this type of interference could have a major impact on the regulation of the host gene expression. PMID:22022525

Contribution of Common Genetic Variation to the Risk of Type 2 Diabetes in the Mexican Mestizo Population

PubMed Central

Gamboa-Meléndez, Marco Alberto; Huerta-Chagoya, Alicia; Moreno-Macías, Hortensia; Vázquez-Cárdenas, Paola; Ordóñez-Sánchez, María Luisa; Rodríguez-Guillén, Rosario; Riba, Laura; Rodríguez-Torres, Maribel; Guerra-García, María Teresa; Guillén-Pineda, Luz Elizabeth; Choudhry, Shweta; del Bosque-Plata, Laura; Canizales-Quinteros, Samuel; Pérez-Ortiz, Gustavo; Escobedo-Aguirre, Fernando; Parra, Adalberto; Lerman-Garber, Israel; Aguilar-Salinas, Carlos Alberto; Tusié-Luna, María Teresa

2012-01-01

Several studies have identified nearly 40 different type 2 diabetes susceptibility loci, mainly in European populations, but few of them have been evaluated in the Mexican population. The aim of this study was to examine the extent to which 24 common genetic variants previously associated with type 2 diabetes are associated in Mexican Mestizos. Twenty-four single nucleotide polymorphisms (SNPs) in or near genes (KCNJ11, PPARG, TCF7L2, SLC30A8, HHEX, CDKN2A/2B, CDKAL1, IGF2BP2, ARHGEF11, JAZF1, CDC123/CAMK1D, FTO, TSPAN8/LGR5, KCNQ1, THADA, ADAMTS9, NOTCH2, NXPH1, RORA, UBQLNL, and RALGPS2) were genotyped in Mexican Mestizos. A case-control association study comprising 1,027 type 2 diabetic individuals and 990 control individuals was conducted. To account for population stratification, a panel of 104 ancestry-informative markers was analyzed. Association to type 2 diabetes was found for rs13266634 (SLC30A8), rs7923837 (HHEX), rs10811661 (CDKN2A/2B), rs4402960 (IGF2BP2), rs12779790 (CDC123/CAMK1D), and rs2237892 (KCNQ1). In addition, rs7754840 (CDKAL1) was associated in the nonobese type 2 diabetic subgroup, and for rs7903146 (TCF7L2), association was observed for early-onset type 2 diabetes. Lack of association for the rest of the variants may have resulted from insufficient power to detect smaller allele effects. PMID:22923468

Phosphorylation of nuclear factor erythroid 2-like 2 (NFE2L2) in mammary tissue of Holstein cows during the periparturient period is associated with mRNA abundance of antioxidant gene networks.

PubMed

Han, L Q; Zhou, Z; Ma, Y; Batistel, F; Osorio, J S; Loor, J J

2018-04-18

Changes in the production of reactive oxygen species in the mammary gland of dairy cows during the periparturient period could lead to oxidative stress and potentially impair mammary function. Phosphorylation of the transcription factor nuclear factor erythroid 2-like 2 (NFE2L2), also known as nuclear factor-E2-related factor 2, controls mRNA abundance of genes encoding antioxidant proteins and enzymes. The hypothesis was that NFE2L2 phosphorylation status and target gene mRNA abundance in the mammary gland of dairy cows is altered around parturition. Total NFE2L2 protein, phosphorylated protein (p-NFE2L2), and ratio of p-NFE2L2 to NFE2L2 along with mRNA abundance of 24 genes related to the NFE2L2 signaling pathway, apoptosis, and cell proliferation were measured in mammary tissue samples from Holstein cows at -30, 1, 15, and 30 d relative to parturition. Although total NFE2L2 protein abundance did not differ, p-NFE2L2 and p-NFE2L2-to-NFE2L2 ratio were greater after parturition. The upregulation of DNA damage inducible transcript 3 (DDIT3) postpartum indicated a localized oxidative stress state. Among genes evaluated, thioredoxin (TXN), glutathione peroxidase 1 (GPX1), and glutathione S-transferase mu 1 (GSTM1) had the highest (37.1, 15.1, and 4.8% of total mRNA measured, respectively) abundance. The mRNA abundance of various target genes with detoxifying enzymatic functions and free radical scavenging activities [glutamate-cysteine ligase catalytic subunit (GCLC); glutathione reductase (GSR); ferrochelatase (FECH); TXN; thioredoxin reductase 1 (TXNRD1); and NAD(P)H quinone dehydrogenase 1 (NQO1)] were consistently upregulated (linear effect of time) as parturition approached and lactation began. Among the transcription regulators, NFE2L2 had the highest mRNA abundance (7.3% of total mRNA measured). Abundance of NFE2L2 and other transcription factors [nuclear factor kappa B subunit 1 (NFKB1), retinoid X receptor α (RXRA), and mitogen-activated protein kinase 14

A compendium of transcription factor and Transcriptionally active protein coding gene families in cowpea (Vigna unguiculata L.).

PubMed

Misra, Vikram A; Wang, Yu; Timko, Michael P

2017-11-22

Cowpea (Vigna unguiculata (L.) Walp.) is the most important food and forage legume in the semi-arid tropics of sub-Saharan Africa where approximately 80% of worldwide production takes place primarily on low-input, subsistence farm sites. Among the major goals of cowpea breeding and improvement programs are the rapid manipulation of agronomic traits for seed size and quality and improved resistance to abiotic and biotic stresses to enhance productivity. Knowing the suite of transcription factors (TFs) and transcriptionally active proteins (TAPs) that control various critical plant cellular processes would contribute tremendously to these improvement aims. We used a computational approach that employed three different predictive pipelines to data mine the cowpea genome and identified over 4400 genes representing 136 different TF and TAP families. We compare the information content of cowpea to two evolutionarily close species common bean (Phaseolus vulgaris), and soybean (Glycine max) to gauge the relative informational content. Our data indicate that correcting for genome size cowpea has fewer TF and TAP genes than common bean (4408 / 5291) and soybean (4408/ 11,065). Members of the GROWTH-REGULATING FACTOR (GRF) and Auxin/indole-3-acetic acid (Aux/IAA) gene families appear to be over-represented in the genome relative to common bean and soybean, whereas members of the MADS (Minichromosome maintenance deficient 1 (MCM1), AGAMOUS, DEFICIENS, and serum response factor (SRF)) and C2C2-YABBY appear to be under-represented. Analysis of the AP2-EREBP APETALA2-Ethylene Responsive Element Binding Protein (AP2-EREBP), NAC (NAM (no apical meristem), ATAF1, 2 (Arabidopsis transcription activation factor), CUC (cup-shaped cotyledon)), and WRKY families, known to be important in defense signaling, revealed changes and phylogenetic rearrangements relative to common bean and soybean that suggest these groups may have evolved different functions. The availability of detailed

Characterization of sequences in human TWIST required for nuclear localization

PubMed Central

Singh, Shalini; Gramolini, Anthony O

2009-01-01

Background Twist is a transcription factor that plays an important role in proliferation and tumorigenesis. Twist is a nuclear protein that regulates a variety of cellular functions controlled by protein-protein interactions and gene transcription events. The focus of this study was to characterize putative nuclear localization signals (NLSs) 37RKRR40 and 73KRGKK77 in the human TWIST (H-TWIST) protein. Results Using site-specific mutagenesis and immunofluorescences, we observed that altered TWISTNLS1 K38R, TWISTNLS2 K73R and K77R constructs inhibit nuclear accumulation of H-TWIST in mammalian cells, while TWISTNLS2 K76R expression was un-affected and retained to the nucleus. Subsequently, co-transfection of TWIST mutants K38R, K73R and K77R with E12 formed heterodimers and restored nuclear localization despite the NLSs mutations. Using a yeast-two-hybrid assay, we identified a novel TWIST-interacting candidate TCF-4, a basic helix-loop-helix transcription factor. The interaction of TWIST with TCF-4 confirmed using NLS rescue assays, where nuclear expression of mutant TWISTNLS1 with co-transfixed TCF-4 was observed. The interaction of TWIST with TCF-4 was also seen using standard immunoprecipitation assays. Conclusion Our study demonstrates the presence of two putative NLS motifs in H-TWIST and suggests that these NLS sequences are functional. Furthermore, we identified and confirmed the interaction of TWIST with a novel protein candidate TCF-4. PMID:19534813

Structural and functional insight into TAF1-TAF7, a subcomplex of transcription factor II D

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhattacharya, Suparna; Lou, Xiaohua; Hwang, Peter

2014-07-01

Transcription factor II D (TFIID) is a multiprotein complex that nucleates formation of the basal transcription machinery. TATA binding protein-associated factors 1 and 7 (TAF1 and TAF7), two subunits of TFIID, are integral to the regulation of eukaryotic transcription initiation and play key roles in preinitiation complex (PIC) assembly. Current models suggest that TAF7 acts as a dissociable inhibitor of TAF1 histone acetyltransferase activity and that this event ensures appropriate assembly of the RNA polymerase II-mediated PIC before transcriptional initiation. Here, we report the 3D structure of a complex of yeast TAF1 with TAF7 at 2.9 Å resolution. The structuremore » displays novel architecture and is characterized by a large predominantly hydrophobic heterodimer interface and extensive cofolding of TAF subunits. There are no obvious similarities between TAF1 and known histone acetyltransferases. Instead, the surface of the TAF1–TAF7 complex contains two prominent conserved surface pockets, one of which binds selectively to an inhibitory trimethylated histone H3 mark on Lys27 in a manner that is also regulated by phosphorylation at the neighboring H3 serine. Our findings could point toward novel roles for the TAF1–TAF7 complex in regulation of PIC assembly via reading epigenetic histone marks.« less

Bone morphogenetic protein 2 activates Smad6 gene transcription through bone-specific transcription factor Runx2.

PubMed

Wang, Qing; Wei, Xiaochao; Zhu, Tianhui; Zhang, Ming; Shen, Run; Xing, Lianping; O'Keefe, Regis J; Chen, Di

2007-04-06

BMP-2 plays an essential role in osteoblast and chondrocyte differentiation, but its signaling mechanism has not been fully defined. In the present studies, we investigated the mechanism through which BMP-2 activates the Smad6 gene. A -2006/+45 Smad6 promoter-luciferase construct was generated along with deletions and Runx2 binding site mutations to examine the role of Smad1 and Runx2 signaling following BMP-2 stimulation in osteoblasts. Transfection of Runx2 or treatment with BMP-2-stimulated promoter activity of the -2006/+45 and -1191/+45 reporters but not the -829/+45 and -374/+45 reporters. No Smad1/5 binding site is present in the -1191/-829 region of the Smad6 promoter. Mutation of the OSE2-a site (-1036/-1031) completely abolished the stimulatory effect of Runx2 as well as BMP-2 on the -2006/+45 and -1191/+45 Smad6 reporters. Gel shift and chromatin immunoprecipitation (ChIP) assays showed that Runx2 binds the OSE2-a element. ChIP assays demonstrated that Smad1 also interacts with the OSE2-a site at the Smad6 promoter through Runx2. The protein degradation of Runx2 is mediated by the E3 ubiquitin ligase Smurf1. In the present studies, we found that Smurf1 binds the OSE2-a site through Runx2 and inhibits Smad6 gene transcription. Treatment with BMP-2 and transfection of Smad1 abolished Smurf1 binding to the OSE2 site. These results show that Smad1 binding excludes Smurf1 interaction with the OSE2 site and promotes Smad6 gene transcription.

Insulin-Increased L-Arginine Transport Requires A2A Adenosine Receptors Activation in Human Umbilical Vein Endothelium

PubMed Central

Guzmán-Gutiérrez, Enrique; Westermeier, Francisco; Salomón, Carlos; González, Marcelo; Pardo, Fabián; Leiva, Andrea; Sobrevia, Luis

2012-01-01

Adenosine causes vasodilation of human placenta vasculature by increasing the transport of arginine via cationic amino acid transporters 1 (hCAT-1). This process involves the activation of A2A adenosine receptors (A2AAR) in human umbilical vein endothelial cells (HUVECs). Insulin increases hCAT-1 activity and expression in HUVECs, and A2AAR stimulation increases insulin sensitivity in subjects with insulin resistance. However, whether A2AAR plays a role in insulin-mediated increase in L-arginine transport in HUVECs is unknown. To determine this, we first assayed the kinetics of saturable L-arginine transport (1 minute, 37°C) in the absence or presence of nitrobenzylthioinosine (NBTI, 10 µmol/L, adenosine transport inhibitor) and/or adenosine receptors agonist/antagonists. We also determined hCAT-1 protein and mRNA expression levels (Western blots and quantitative PCR), and SLC7A1 (for hCAT-1) reporter promoter activity. Insulin and NBTI increased the extracellular adenosine concentration, the maximal velocity for L-arginine transport without altering the apparent K m for L-arginine transport, hCAT-1 protein and mRNA expression levels, and SLC7A1 transcriptional activity. An A2AAR antagonist ZM-241385 blocked these effects. ZM241385 inhibited SLC7A1 reporter transcriptional activity to the same extent in cells transfected with pGL3-hCAT-1−1606 or pGL3-hCAT-1−650 constructs in the presence of NBTI + insulin. However, SLC7A1 reporter activity was increased by NBTI only in cells transfected with pGL3-hCAT-1−1606, and the ZM-241385 sensitive fraction of the NBTI response was similar in the absence or in the presence of insulin. Thus, insulin modulation of hCAT-1 expression and activity requires functional A2AAR in HUVECs, a mechanism that may be applicable to diseases associated with fetal insulin resistance, such as gestational diabetes. PMID:22844517

7 CFR 1.656 - What are the requirements for transcription of the hearing?

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 1 2011-01-01 2011-01-01 false What are the requirements for transcription of the hearing? 1.656 Section 1.656 Agriculture Office of the Secretary of Agriculture ADMINISTRATIVE REGULATIONS... transcription of the hearing? (a) Transcript and reporter's fees. The hearing will be transcribed verbatim. (1...

7 CFR 1.656 - What are the requirements for transcription of the hearing?

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 1 2010-01-01 2010-01-01 false What are the requirements for transcription of the hearing? 1.656 Section 1.656 Agriculture Office of the Secretary of Agriculture ADMINISTRATIVE REGULATIONS... transcription of the hearing? (a) Transcript and reporter's fees. The hearing will be transcribed verbatim. (1...

Pharmacokinetics and transcriptional effects of the anti-salmon lice drug emamectin benzoate in Atlantic salmon (Salmo salar L.)

PubMed Central

Olsvik, Pål A; Lie, Kai K; Mykkeltvedt, Eva; Samuelsen, Ole B; Petersen, Kjell; Stavrum, Anne-Kristin; Lunestad, Bjørn T

2008-01-01

Background Emamectin benzoate (EB) is a dominating pharmaceutical drug used for the treatment and control of infections by sea lice (Lepeophtheirus salmonis) on Atlantic salmon (Salmo salar L). Fish with an initial mean weight of 132 g were experimentally medicated by a standard seven-day EB treatment, and the concentrations of drug in liver, muscle and skin were examined. To investigate how EB affects Atlantic salmon transcription in liver, tissues were assessed by microarray and qPCR at 7, 14 and 35 days after the initiation of medication. Results The pharmacokinetic examination revealed highest EB concentrations in all three tissues at day 14, seven days after the end of the medication period. Only modest effects were seen on the transcriptional levels in liver, with small fold-change alterations in transcription throughout the experimental period. Gene set enrichment analysis (GSEA) indicated that EB treatment induced oxidative stress at day 7 and inflammation at day 14. The qPCR examinations showed that medication by EB significantly increased the transcription of both HSP70 and glutathione-S-transferase (GST) in liver during a period of 35 days, compared to un-treated fish, possibly via activation of enzymes involved in phase II conjugation of metabolism in the liver. Conclusion This study has shown that a standard seven-day EB treatment has only a modest effect on the transcription of genes in liver of Atlantic salmon. Based on GSEA, the medication seems to have produced a temporary oxidative stress response that might have affected protein stability and folding, followed by a secondary inflammatory response. PMID:18786259

Pharmacokinetics and transcriptional effects of the anti-salmon lice drug emamectin benzoate in Atlantic salmon (Salmo salar L.).

PubMed

Olsvik, Pål A; Lie, Kai K; Mykkeltvedt, Eva; Samuelsen, Ole B; Petersen, Kjell; Stavrum, Anne-Kristin; Lunestad, Bjørn T

2008-09-11

Emamectin benzoate (EB) is a dominating pharmaceutical drug used for the treatment and control of infections by sea lice (Lepeophtheirus salmonis) on Atlantic salmon (Salmo salar L). Fish with an initial mean weight of 132 g were experimentally medicated by a standard seven-day EB treatment, and the concentrations of drug in liver, muscle and skin were examined. To investigate how EB affects Atlantic salmon transcription in liver, tissues were assessed by microarray and qPCR at 7, 14 and 35 days after the initiation of medication. The pharmacokinetic examination revealed highest EB concentrations in all three tissues at day 14, seven days after the end of the medication period. Only modest effects were seen on the transcriptional levels in liver, with small fold-change alterations in transcription throughout the experimental period. Gene set enrichment analysis (GSEA) indicated that EB treatment induced oxidative stress at day 7 and inflammation at day 14. The qPCR examinations showed that medication by EB significantly increased the transcription of both HSP70 and glutathione-S-transferase (GST) in liver during a period of 35 days, compared to un-treated fish, possibly via activation of enzymes involved in phase II conjugation of metabolism in the liver. This study has shown that a standard seven-day EB treatment has only a modest effect on the transcription of genes in liver of Atlantic salmon. Based on GSEA, the medication seems to have produced a temporary oxidative stress response that might have affected protein stability and folding, followed by a secondary inflammatory response.

Development of NASA's Next Generation L-Band Digital Beamforming Synthetic Aperture Radar (DBSAR-2)

NASA Technical Reports Server (NTRS)

Rincon, Rafael; Fatoyinbo, Temilola; Osmanoglu, Batuhan; Lee, Seung-Kuk; Ranson, K. Jon; Marrero, Victor; Yeary, Mark

2014-01-01

NASA's Next generation Digital Beamforming SAR (DBSAR-2) is a state-of-the-art airborne L-band radar developed at the NASA Goddard Space Flight Center (GSFC). The instrument builds upon the advanced architectures in NASA's DBSAR-1 and EcoSAR instruments. The new instrument employs a 16-channel radar architecture characterized by multi-mode operation, software defined waveform generation, digital beamforming, and configurable radar parameters. The instrument has been design to support several disciplines in Earth and Planetary sciences. The instrument was recently completed, and tested and calibrated in a anechoic chamber.

Stimulation of d- and l-lactate dehydrogenases transcriptional levels in presence of diammonium hydrogen phosphate resulting to enhanced lactic acid production by Lactobacillus strain.

PubMed

Singhvi, Mamata; Zendo, Takeshi; Iida, Hiroshi; Gokhale, Digambar; Sonomoto, Kenji

2017-12-01

The present study revealed the effect of nitrogen sources on lactic acid production and stimulation of d- and l-lactate dehydrogenases (LDH) of parent Lactobacillus lactis NCIM 2368 and its mutant RM2-24 generated after UV mutagenesis. Both the parent and mutant strains were evaluated for d-lactic acid production in control and modified media. The modified media did not show remarkable effect on lactic acid production in case of parent whereas mutant exhibited significant enhancement in d-lactic acid production along with the appearance of l-lactic acid in the broth. Both LDH activities and specific activities were found to be higher in mutant than the parent strain. These results suggested that the diammonium hydrogen phosphate in modified media triggered the expression of LDH genes leading to enhanced lactic acid production. This observation has been proved by studying the expression levels of d- and l-LDH genes of parent and mutant in control and modified media using quantitative RT-PCR technique. In case of mutant, the transcriptional levels of d-LDH and l-LDH increased ∼17 fold and ∼1.38 fold respectively in modified medium compared to the values obtained with control medium. In case of parent, no significant change in transcriptional levels of d- and l-LDH was found when the cells were grown in either control medium or modified medium. This study suggested that the mutant, RM2-24 has l-LDH gene which is expressed in presence of (NH 4 ) 2 HPO 4 resulting in l-lactic acid production. Co-production of l-lactic acid in d-lactic acid fermentation may be detrimental in the PLA production. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.