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Publication
Journal: Nucleic Acids Research
June/28/2015
Abstract
Transcription factors (TFs) are key regulators for gene expression. Here we updated the animal TF database AnimalTFDB to version 2.0 (http://bioinfo.life.hust.edu.cn/AnimalTFDB/). Using the improved prediction pipeline, we identified 72 336 TF genes, 21 053 transcription co-factor genes and 6502 chromatin remodeling factor genes from 65 species covering main animal lineages. Besides the abundant annotations (basic information, gene model, protein functional domain, gene ontology, pathway, protein interaction, ortholog and paralog, etc.) in the previous version, we made several new features and functions in the updated version. These new features are: (i) gene expression from RNA-Seq for nine model species, (ii) gene phenotype information, (iii) multiple sequence alignment of TF DNA-binding domains, and the weblogo and phylogenetic tree based on the alignment, (iv) a TF prediction server to identify new TFs from input sequences and (v) a BLAST server to search against TFs in AnimalTFDB. A new nice web interface was designed for AnimalTFDB 2.0 allowing users to browse and search all data in the database. We aim to maintain the AnimalTFDB as a solid resource for TF identification and studies of transcription regulation and comparative genomics.
Publication
Journal: Nucleic Acids Research
March/13/2012
Abstract
Transcription factor (TF) binding and histone modification (HM) are important for the precise control of gene expression. Hence, we constructed statistical models to relate these to gene expression levels in mouse embryonic stem cells. While both TF binding and HMs are highly 'predictive' of gene expression levels (in a statistical, but perhaps not strictly mechanistic, sense), we find they show distinct differences in the spatial patterning of their predictive strength: TF binding achieved the highest predictive power in a small DNA region centered at the transcription start sites of genes, while the HMs exhibited high predictive powers across a wide region around genes. Intriguingly, our results suggest that TF binding and HMs are redundant in strict statistical sense for predicting gene expression. We also show that our TF and HM models are cell line specific; specifically, TF binding and HM are more predictive of gene expression in the same cell line, and the differential gene expression between cell lines is predictable by differential HMs. Finally, we found that the models trained solely on protein-coding genes are predictive of expression levels of microRNAs, suggesting that their regulation by TFs and HMs may share a similar mechanism to that for protein-coding genes.
Publication
Journal: BMC Evolutionary Biology
September/28/2008
Abstract
BACKGROUND
Five regulatory factor X (RFX) transcription factors (TFs)-RFX1-5-have been previously characterized in the human genome, which have been demonstrated to be critical for development and are associated with an expanding list of serious human disease conditions including major histocompatibility (MHC) class II deficiency and ciliaophathies.
RESULTS
In this study, we have identified two additional RFX genes-RFX6 and RFX7-in the current human genome sequences. Both RFX6 and RFX7 are demonstrated to be winged-helix TFs and have well conserved RFX DNA binding domains (DBDs), which are also found in winged-helix TFs RFX1-5. Phylogenetic analysis suggests that the RFX family in the human genome has undergone at least three gene duplications in evolution and the seven human RFX genes can be clearly categorized into three subgroups: (1) RFX1-3, (2) RFX4 and RFX6, and (3) RFX5 and RFX7. Our functional genomics analysis suggests that RFX6 and RFX7 have distinct expression profiles. RFX6 is expressed almost exclusively in the pancreatic islets, while RFX7 has high ubiquitous expression in nearly all tissues examined, particularly in various brain tissues.
CONCLUSIONS
The identification and further characterization of these two novel RFX genes hold promise for gaining critical insight into development and many disease conditions in mammals, potentially leading to identification of disease genes and biomarkers.
Publication
Journal: Journal of Thrombosis and Haemostasis
February/19/2004
Abstract
BACKGROUND
Circulating microparticles of various cell types are present in healthy individuals and, in varying numbers and antigenic composition, in various disease states. To what extent these microparticles contribute to coagulation in vivo is unknown.
OBJECTIVE
To examine the in vivo thrombogenicity of human microparticles.
METHODS
Microparticles were isolated from pericardial blood of cardiac surgery patients and venous blood of healthy individuals. Their numbers, cellular source, and tissue factor (TF) exposure were determined using flow cytometry. Their in vitro procoagulant properties were studied in a fibrin generation test, and their in vivo thrombogenicity in a rat model.
RESULTS
The total number of microparticles did not differ between pericardial samples and samples from healthy individuals (P = 0.786). In both groups, microparticles from platelets, erythrocytes, and granulocytes exposed TF. Microparticle-exposed TF antigen levels were higher in pericardial compared with healthy individual samples (P = 0.036). Pericardial microparticles were strongly procoagulant in vitro and highly thrombogenic in a venous stasis thrombosis model in rats, whereas microparticles from healthy individuals were not [thrombus weights 24.8 (12.2-41.3) mg vs. 0 (0-24.3) mg median and range; P < 0.001]. Preincubation of pericardial microparticles with an inhibitory antibody against human TF abolished their thrombogenicity [0 (0-4.4) mg; P < 0.01], while a control antibody had no effect [19.6 (12.6-53.7) mg; P>> 0.05]. The thrombogenicity of the microparticles correlated strongly with their TF exposure (r = 0.9524, P = 0.001).
CONCLUSIONS
Human cell-derived microparticles promote thrombus formation in vivo in a TF-dependent manner. They might be the direct cause of an increased thromboembolic tendency in various patient groups.
Publication
Journal: New Phytologist
May/18/2016
Abstract
Next to numerous abiotic stresses, plants are constantly exposed to a variety of pathogens within their environment. Thus, their ability to survive and prosper during the course of evolution was strongly dependent on adapting efficient strategies to perceive and to respond to such potential threats. It is therefore not surprising that modern plants have a highly sophisticated immune repertoire consisting of diverse signal perception and intracellular signaling pathways. This signaling network is intricate and deeply interconnected, probably reflecting the diverse lifestyles and infection strategies used by the multitude of invading phytopathogens. Moreover it allows signal communication between developmental and defense programs thereby ensuring that plant growth and fitness are not significantly retarded. How plants integrate and prioritize the incoming signals and how this information is transduced to enable appropriate immune responses is currently a major research area. An important finding has been that pathogen-triggered cellular responses involve massive transcriptional reprogramming within the host. Additional key observations emerging from such studies are that transcription factors (TFs) are often sites of signal convergence and that signal-regulated TFs act in concert with other context-specific TFs and transcriptional co-regulators to establish sensory transcription regulatory networks required for plant immunity.
Publication
Journal: Genome Research
April/10/2003
Abstract
As the number of sequenced genomes has grown, the questions of which species are most useful and how many genomes are sufficient for comparison have become increasingly important for comparative genomics studies. We have systematically addressed these questions with respect to phylogenetic footprinting of transcription factor (TF) binding sites in the gamma-proteobacteria, and have evaluated the statistical significance of our motif predictions. We used a study set of 166 Escherichia coli genes that have experimentally identified TF binding sites upstream of the gene, with orthologous data from nine additional gamma-proteobacteria for phylogenetic footprinting. Just three species were sufficient for approximately 74.0% of the motif predictions to correspond to the experimentally reported E. coli sites, and important characteristics to consider when choosing species were phylogenetic distance, genome size, and natural habitat. We also performed simulations using randomized data to determine the critical maximum a posteriori probability (MAP) values for statistical significance of our motif predictions (P = 0.05). Approximately 60% of motif predictions containing sites from just three species had average MAP values above these critical MAP values. The inclusion of a species very closely related to E. coli increased the number of statistically significant motif predictions, despite substantially increasing the critical MAP value.
Publication
Journal: Blood
November/3/1999
Abstract
We have investigated the influence of alterations in plasma coagulation factor levels between 50% and 150% of their mean values for prothrombin, factor X, factor XI, factor IX, factor VII, factor VIII, factor V, protein C, protein S, antithrombin III (AT-III), and tissue factor pathway inhibitor (TFPI) as well as combinations of extremes, eg, 50% anticoagulants and 150% procoagulants or 50% procoagulants and 150% anticoagulants in a synthetic "plasma" system. The reaction systems were constructed in vitro using purified, natural, and recombinant proteins and synthetic phospholipid vesicles or platelets with the reactions initiated by recombinant tissue factor (TF)-factor VIIa complex (5 pmol/L). To investigate the influence of the protein C system, soluble thrombomodulin (Tm) was also added to the reaction mixture. For the most extreme situations in which the essential plasma procoagulants (prothrombin, and factors X, IX, V, and VIII) and the stoichiometric anticoagulants (AT-III and TFPI) were collectively and inversely altered by 50%, a 28-fold difference in the total available thrombin generated was observed. Variations of most of these proteins 50% above and below the "normal" range, with the remainder at 100%, had only modest influences on the peak and total levels of thrombin generated. The dominant factors influencing thrombin generation were prothrombin and AT-III. When these 2 components were held at 100% and all other plasma procoagulants were reduced to 50%, there was a 60% reduction in the available thrombin generated. No increase in the thrombin generated was observed when the 150% level of all plasma procoagulants other than prothrombin was evaluated. When only prothrombin was raised to 150%, and all other factors were maintained at 100%, the thrombin generated increased by 71% to 121%. When AT-III was at 50% and all other constituents were at 100%, thrombin production was increased by 104% to 196%. The additions of protein C and protein S over the 50% to 150% ranges with Tm at 0.1 nmol/L concentration had limited influence on thrombin generation. Individual variations in factors VII, XI, and X concentrations had little effect on the duration of the initiation phase, the peak thrombin level achieved, or the available thrombin generated. Paradoxically, increases in factor IX concentration to 150% led to lowered thrombin generation, while decreases to 50% led to enhanced thrombin generation, most likely a consequence of factor IX as a competitive substrate with factor X for factor VIIa-TF. Reductions in factor V or factor VIII concentration led to prolongations of the initiation phase, while the reduction of TFPI to 50% led to shortening of this phase. However, none of these alterations led to significant changes in the available thrombin generated. Based on these data, one might surmise that increases in prothrombin and reductions in AT-III, within the normal range, would be potential risk factors for thrombosis and that algorithms that combine normal factor levels may be required to develop predictive tests for thrombosis.
Publication
Journal: Proceedings of the National Academy of Sciences of the United States of America
April/21/2005
Abstract
Decomposing transcriptional regulatory networks into functional modules and determining logical relations between them is the first step toward understanding transcriptional regulation at the system level. Modules based on analysis of genome-scale data can serve as the basis for inferring combinatorial regulation and for building mathematical models to quantitatively describe the behavior of the networks. We present here an algorithm called modem to identify target genes of a transcription factor (TF) from a single expression experiment, based on a joint probabilistic model for promoter sequence and gene expression data. We show how this method can facilitate the discovery of specific instances of combinatorial regulation and illustrate this for a specific case of transcriptional networks that regulate sporulation in the yeast Saccharomyces cerevisiae. Applying this method to analyze two crucial TFs in sporulation, Ndt80p and Sum1p, we were able to delineate their overlapping binding sites. We proposed a mechanistic model for the competitive regulation by the two TFs on a defined subset of sporulation genes. We show that this model accounts for the temporal control of the "middle" sporulation genes and suggest a similar regulatory arrangement can be found in developmental programs in higher organisms.
Publication
Journal: Journal of Cell Biology
November/24/1996
Abstract
We have evaluated transcytotic routes in MDCK cells for their ability to generate a polarized surface distribution of trafficking proteins by following the intracellular sorting of transferrin receptors (TRs). We find that the selective basolateral expression of TRs is maintained in the face of extensive trafficking between the apical and basolateral surfaces. Biochemical studies of receptors loaded with tracer under conditions approaching steady state indicate that TRs internalized from the two surfaces are extensively colocalized within MDCK cells and that both populations of receptors are selectively delivered to the basolateral surface. Tailless TRs in which the cytoplasmic domain has been deleted display an unpolarized cell surface distribution and recycle in an unpolarized fashion. We show by EM that wild-type receptors internalized from each surface are colocalized within endosomal elements distributed throughout the cytoplasm. By preloading endosomal elements directly accessible from the basolateral surface with transferrin (Tf)-HRP, we show that apically internalized TRs rapidly enter the same compartment. We also show that both transcytosing (apically internalized) and recycling (basolaterally internalized) TRs are delivered to the basolateral border by a distinctive subset of exocytotic, 60-nm-diam vesicles. Together, the biochemical and morphological data show that apical and basolateral endosomes of MDCK cells are interconnected and contain a signal-dependent polarized sorting mechanism. We propose a dynamic model of polarized sorting in MDCK cells in which a single endosome-based, signal-dependent sorting step is sufficient to maintain the polarized phenotype.
Publication
Journal: Molecular Cell
September/2/2004
Abstract
Related coactivators p300 and CBP affect the transcriptional activities of many transcription factors (TF), producing multiple downstream effects. Here we show that immediate early response TF, Egr1, acts upstream of p300/CBP to induce or to repress transcription, depending on the stimulus. Cells induced with serum to increase endogenous Egr1 increase the transcription of p300/CBP only when Egr1 binding sites in the promoter are not mutated, causing the expression of downstream targets of Egr1 which leads to survival and growth. Induction of p300/CBP by Egr1 results in acetylation and stabilization of Egr1 and transactivation of survival genes but repression of Egr1 and p300/CBP in negative feedback loops. In contrast, induction of Egr1 by UV-C irradiation leads to repression of p300/CBP transcription: Egr1 is preferentially phosphorylated, leading to regulation of target genes that cause cell death. This complex balance of opposing effects appears to finely modulate important cellular life and death responses.
Publication
Journal: PLoS Medicine
September/28/2014
Abstract
BACKGROUND
Trachoma is the world's leading cause of infectious blindness. The World Health Organization (WHO) has endorsed the SAFE strategy in order to eliminate blindness due to trachoma by 2020 through "surgery," "antibiotics," "facial cleanliness," and "environmental improvement." While the S and A components have been widely implemented, evidence and specific targets are lacking for the F and E components, of which water, sanitation, and hygiene (WASH) are critical elements. Data on the impact of WASH on trachoma are needed to support policy and program recommendations. Our objective was to systematically review the literature and conduct meta-analyses where possible to report the effects of WASH conditions on trachoma and identify research gaps.
RESULTS
We systematically searched PubMed, Embase, ISI Web of Knowledge, MedCarib, Lilacs, REPIDISCA, DESASTRES, and African Index Medicus databases through October 27, 2013 with no restrictions on language or year of publication. Studies were eligible for inclusion if they reported a measure of the effect of WASH on trachoma, either active disease indicated by observed signs of trachomatous inflammation or Chlamydia trachomatis infection diagnosed using PCR. We identified 86 studies that reported a measure of the effect of WASH on trachoma. To evaluate study quality, we developed a set of criteria derived from the GRADE methodology. Publication bias was assessed using funnel plots. If three or more studies reported measures of effect for a comparable WASH exposure and trachoma outcome, we conducted a random-effects meta-analysis. We conducted 15 meta-analyses for specific exposure-outcome pairs. Access to sanitation was associated with lower trachoma as measured by the presence of trachomatous inflammation-follicular or trachomatous inflammation-intense (TF/TI) (odds ratio [OR] 0.85, 95% CI 0.75-0.95) and C. trachomatis infection (OR 0.67, 95% CI 0.55-0.78). Having a clean face was significantly associated with reduced odds of TF/TI (OR 0.42, 95% CI 0.32-0.52), as were facial cleanliness indicators lack of ocular discharge (OR 0.42, 95% CI 0.23-0.61) and lack of nasal discharge (OR 0.62, 95% CI 0.52-0.72). Facial cleanliness indicators were also associated with reduced odds of C. trachomatis infection: lack of ocular discharge (OR 0.40, 95% CI 0.31-0.49) and lack of nasal discharge (OR 0.56, 95% CI 0.37-0.76). Other hygiene factors found to be significantly associated with reduced TF/TI included face washing at least once daily (OR 0.76, 95% CI 0.57-0.96), face washing at least twice daily (OR 0.85, 95% CI 0.80-0.90), soap use (OR 0.76, 95% CI 0.59-0.93), towel use (OR 0.65, 95% CI 0.53-0.78), and daily bathing practices (OR 0.76, 95% CI 0.53-0.99). Living within 1 km of a water source was not found to be significantly associated with TF/TI or C. trachomatis infection, and the use of sanitation facilities was not found to be significantly associated with TF/TI.
CONCLUSIONS
We found strong evidence to support F and E components of the SAFE strategy. Though limitations included moderate to high heterogenity, low study quality, and the lack of standard definitions, these findings support the importance of WASH in trachoma elimination strategies and the need for the development of standardized approaches to measuring WASH in trachoma control programs.
Publication
Journal: Critical Reviews in Oncology/Hematology
September/15/2002
Abstract
For many years it has been known that neoplastic cells express high levels of the transferrin receptor 1 (TfR1) and internalize iron (Fe) from transferrin (Tf) at a tremendous rate. Considering the high requirement of neoplastic cells for Fe, understanding its metabolism is vital in terms of devising potential new therapies. Apart from TfR1, a number of molecules have been identified that may have roles in Fe metabolism and cellular proliferation. These molecules include transferrin (Tf), the oestrogen-inducible transferrin receptor-like protein, transferrin receptor 2 (TfR2), melanotransferrin (MTf), ceruloplasmin, and ferritin. In the present review these latter molecules are discussed in terms of their potential functions in tumour cell Fe metabolism and proliferation. Further studies are essential to determine the specific roles of these proteins in the pathogenesis of cancer.
Publication
Journal: Behavioural Brain Research
November/15/2010
Abstract
The core symptoms of autism spectrum disorder (ASD) include deficits in social interaction, impaired communication, and repetitive behaviors with restricted interests. Mouse models with behavioral phenotypes relevant to these core symptoms offer an experimental approach to advance the investigation of genes associated with ASD. Previous findings demonstrate that BTBR T+ tf/J (BTBR) is an inbred mouse strain that shows robust behavioral phenotypes with analogies to all three of the diagnostic symptoms of ASD. In the present study, we investigated the expression of social behaviors in a semi-natural visible burrow system (VBS), during colony formation and maintenance in groups comprising three adult male mice of the same strain, either C57BL/6J (B6) or BTBR. For comparative purposes, an extensively investigated three-chambered test was subsequently used to assess social approach in both strains. The effects of strain on these two situations were consistent and highly significant. In the VBS, BTBR mice showed reductions in all interactive behaviors: approach (front and back), flight, chase/follow, allo-grooming and huddling, along with increases in self-grooming and alone, as compared to B6. These results were corroborated in the three-chambered test: in contrast to B6, male BTBR mice failed to spend more time in the side of the test box containing the unfamiliar CD-1 mouse. Overall, the present data indicates that the strain profile for BTBR mice, including consistent social deficits and high levels of repetitive self-grooming, models multiple components of the ASD phenotype.
Publication
Journal: Journal of Biological Chemistry
July/28/2004
Abstract
Tissue factor (TF) is the physiological activator of the coagulation cascade that plays pathophysiological roles in metastasis, angiogenesis, and inflammation. Downstream in coagulation, thrombin is the central protease that signals through G protein-coupled, protease-activated receptors (PARs). However, the TF-VIIa-Xa complex upstream in coagulation also activates PAR1 and 2. Here, we address the question of whether signaling of the TF initiation complex is a relevant pathway that leads to TF cytoplasmic domain phosphorylation. In heterologous expression systems and primary endothelial cells, we demonstrate that the ternary TF-VIIa-Xa complex induces TF phosphorylation specifically by activating PAR2 but not through PAR1 signaling. In addition, TF cytoplasmic domain phosphorylation is induced only by TF-dependent signaling but not by other coagulation factors in endothelial cells. Phosphorylation of the Pro-directed kinase target site Ser258 is dependent on prior phosphorylation of Ser253 by protein kinase C (PKC) alpha. TF phosphorylation is somewhat delayed and coincides with sustained PKCalpha activation downstream of PAR2 but not PAR1 signaling. Phosphatidylcholine-dependent phospholipase C is the major pathway that leads to prolonged PKCalpha recruitment downstream of PAR2. Thus, PAR2 signaling specifically phosphorylates TF in a receptor cross-talk that distinguishes upstream from downstream coagulation protease signaling.
Publication
Journal: Archives of pediatrics & adolescent medicine
February/7/2011
Abstract
OBJECTIVE
To evaluate community-provided trauma-focused cognitive behavior therapy (TF-CBT) compared with usual community treatment for children with intimate partner violence (IPV)-related posttraumatic stress disorder (PTSD) symptoms.
METHODS
Randomized controlled trial conducted using blinded evaluators.
METHODS
Recruitment, screening, and treatment were conducted at a community IPV center between September 1, 2004, and June 30, 2009.
METHODS
Of 140 consecutively referred 7- to 14-year-old children, 124 participated.
METHODS
Children and mothers were randomly assigned to receive 8 sessions of TF-CBT or usual care (child-centered therapy).
METHODS
Total child PTSD symptoms assessed using child and parent structured interview (Kiddie Schedule for Affective Disorders and Schizophrenia, Present and Lifetime Version [K-SADS-PL]) and self-report (University of California at Los Angeles PTSD Reaction Index [RI]). Secondary child outcomes were scores on the K-SADS-PL (PTSD symptom clusters), Screen for Child Anxiety Related Emotional Disorders (SCARED) (anxiety), Children's Depression Inventory (depression), Kaufman Brief Intelligence Test (cognitive functioning), and Child Behavior Checklist (total behavior problems).
RESULTS
Intent-to-treat analysis using last observation carried forward showed superior outcomes for TF-CBT on the total K-SADS-PL (mean difference, 1.63; 95% confidence interval [CI], 0.44-2.82), RI (mean difference, 5.5; 95% CI, 1.37-9.63), K-SADS-PL hyperarousal (mean difference, 0.71; 95% CI, 0.22-1.20), K-SADS-PL avoidance (0.55; 0.07-1.03), and SCARED (mean difference, 5.13; 95% CI, 1.31-8.96). Multiple imputation analyses confirmed most of these findings. The TF-CBT completers experienced significantly greater PTSD diagnostic remission (χ(2) = 4.67, P = .03) and had significantly fewer serious adverse events.
CONCLUSIONS
Community TF-CBT effectively improves children's IPV-related PTSD and anxiety.
BACKGROUND
clinicaltrials.gov Identifier: NCT00183326.
Publication
Journal: Thorax
August/14/2007
Abstract
BACKGROUND
The alveolar compartment is a procoagulant antifibrinolytic environment in acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS). A study was undertaken to test the hypothesis that the alveolar epithelium can initiate intra-alveolar coagulation by expressing active tissue factor (TF).
METHODS
Using an in vitro cell surface TF assay and TF ELISA, the activity and production of TF in cultured alveolar epithelial (A549) cells following exposure to cytomix (tumour necrosis factor alpha, interleukin 1beta and interferon gamma) was measured. TF gene transcription was measured by semi-quantitative reverse-transcription PCR. Immunohistochemistry for TF was performed on lung sections from patients with ARDS and controls. TF protein levels were measured by ELISA in undiluted pulmonary oedema fluid from patients with ALI/ARDS and compared with control patients with hydrostatic pulmonary oedema.
RESULTS
TF activity, mRNA and protein levels increased in A549 cells after stimulation with cytomix. Increased TF activity was also seen in A549 cells following incubation with pulmonary oedema fluid from patients with ALI/ARDS. Immunohistochemistry for TF in human lung tissue from patients with ARDS showed prominent TF staining in alveolar epithelial cells as well as intra-alveolar macrophages and hyaline membranes. TF antigen levels in oedema fluid (median 37 113 (IQR 14 956-73 525) pg/ml) were significantly higher than in plasma (median 336 (IQR 165-669) pg/ml, p<0.001) in patients with ALI/ARDS, and TF procoagulant activity in oedema fluid was much higher than in plasma of these patients. Higher plasma levels were associated with mortality.
CONCLUSIONS
The alveolar epithelium is capable of modulating intra-alveolar coagulation through upregulation of TF following exposure to inflammatory stimuli and may contribute to intra-alveolar fibrin deposition in ARDS.
Publication
Journal: Molecular Cell
September/20/2015
Abstract
Anti-sense transcription originating upstream of mammalian protein-coding genes is a well-documented phenomenon, but remarkably little is known about the regulation or function of anti-sense promoters and the non-coding RNAs they generate. Here we define at nucleotide resolution the divergent transcription start sites (TSSs) near mouse mRNA genes. We find that coupled sense and anti-sense TSSs precisely define the boundaries of a nucleosome-depleted region (NDR) that is highly enriched in transcription factor (TF) motifs. Notably, as the distance between sense and anti-sense TSSs increases, so does the size of the NDR, the level of signal-dependent TF binding, and gene activation. We further discover a group of anti-sense TSSs in macrophages with an enhancer-like chromatin signature. Interestingly, this signature identifies divergent promoters that are activated during immune challenge. We propose that anti-sense promoters serve as platforms for TF binding and establishment of active chromatin to further regulate or enhance sense-strand mRNA expression.
Publication
Journal: Molecular Genetics and Genomics
June/21/2009
Abstract
Drought is detrimental to plant growth and development, and often results in significant losses to the yields of economically important crops such as soybeans (Glycine max L.). NAC transcription factors (TFs), which consist of a large family of plant-specific TFs, have been reported to enhance drought tolerance in a number of plants. In this study, 31 unigenes that contain the complete open reading frames encoding GmNAC proteins were identified and cloned from soybean. Analysis of C-terminal regulatory domain using yeast one-hybrid system indicated that among 31 GmNAC proteins, 28 have transcriptional activation activity. Expression analysis of these GmNAC genes showed that they are differentially expressed in different organs, suggesting that they have diverse functions during plant growth and development. To search for the drought-inducible GmNAC genes, we prescreened and re-confirmed by quantitative real-time PCR analysis that nine GmNAC genes are induced by dehydration stress with differential induction levels in both shoot and root. The expression profiles of these nine GmNAC genes were also examined under other stresses such as high salinity, cold and with abscisic acid hormone treatments. Phylogenetic analysis of the GmNAC proteins with previously reported drought-inducible NAC proteins of Arabidopsis and rice revealed that the nine drought-inducible GmNAC proteins belong to the "stress-inducible" NAC group. The results of this systematic analysis of the GmNAC family will provide novel tools and resources for the development of improved drought tolerant transgenic soybean cultivars.
Publication
Journal: Cell Reports
June/19/2016
Abstract
Although DNA methylation is commonly invoked as a mechanism for transcriptional repression, the extent to which it actively silences transcription factor (TF) occupancy sites in vivo is unknown. To study the role of DNA methylation in the active modulation of TF binding, we quantified the effect of DNA methylation depletion on the genomic occupancy patterns of CTCF, an abundant TF with known methylation sensitivity that is capable of autonomous binding to its target sites in chromatin. Here, we show that the vast majority (>98.5%) of the tens of thousands of unoccupied, methylated CTCF recognition sequences remain unbound upon abrogation of DNA methylation. The small fraction of sites that show methylation-dependent binding in vivo are in turn characterized by highly variable CTCF occupancy across cell types. Our results suggest that DNA methylation is not a primary groundskeeper of genomic TF landscapes, but rather a specialized mechanism for stabilizing intrinsically labile sites.
Publication
Journal: Clinical Cancer Research
September/16/2007
Abstract
OBJECTIVE
To characterize the safety and immunogenicity of a heptavalent antigen-keyhole limpet hemocyanin (KLH) plus QS21 vaccine construct in patients with epithelial ovarian, fallopian tube, or peritoneal cancer in second or greater complete clinical remission.
METHODS
Eleven patients in this pilot trial received a heptavalent vaccine s.c. containing GM2 (10 microg), Globo-H (10 microg), Lewis Y (10 microg), Tn(c) (3 microg), STn(c) (3 microg), TF(c) (3 microg), and Tn-MUC1 (3 microg) individually conjugated to KLH and mixed with adjuvant QS21(100 microg). Vaccinations were administered at weeks 1, 2, 3, 7, and 15. Periodic blood and urine samples were obtained to monitor safety (complete blood count, comprehensive panel, amylase, thyroid-stimulating hormone, and urinalysis) and antibody production (ELISA, fluorescence-activated cell sorting, and complement-dependent cytotoxicity).
RESULTS
Eleven patients were included in the safety analysis; 9 of 11 patients remained on study for at least 2 weeks past fourth vaccination and were included in the immunologic analysis (two withdrew, disease progression). The vaccine was well tolerated. Self-limited and mild fatigue (maximum grade 2 in two patients), fever, myalgia, and localized injection site reactions were most frequent. No clinically relevant hematologic abnormalities were noted. No clinical or laboratory evidence of autoimmunity was seen. Serologic responses by ELISA were largely IgM against each antigen with the exception of Tn-MUC1 where both IgM and IgG responses were induced. Antibody responses were generally undetectable before immunization. After immunization, median IgM titers were as follows: Tn-MUC1, 1:640 (IgG 1:80); Tn, 1:160; TF, 1:640; Globo-H, 1:40; and STn, 1:80. Only one response was seen against Lewis Y; two were against GM2. Eight of nine patients developed responses against at least three antigens. Antibody titers peaked at weeks 4 to 8 in all patients. Fluorescence-activated cell sorting and complement-dependent cytotoxicity analysis showed substantially increased reactivity against MCF7 cells in seven of nine patients, with some increase seen in all patients.
CONCLUSIONS
This heptavalent-KLH conjugate plus QS21 vaccine safely induced antibody responses against five of seven antigens. Investigation in an adequately powered efficacy trial is warranted.
Publication
Journal: Blood
March/5/2007
Abstract
Blood cell progenitors were scanned for the presence of the coagulation starter protein tissue factor (TF) by immunoelectron microscopy. Thereby, substantial TF expression was observed in the precursor cells of eosinophils. TF levels were lower in basophil precursors and barely detectable in neutrophil progenitors. In peripheral blood immediately processed to avoid activation of the TF gene, mature eosinophils were found to considerably express TF, unique among the granulocyte and monocyte fractions. TF was preferentially located in the specific granules in resting eosinophils. Platelet-activating factor (PAF), and more pronounced, granulocyte-macrophage colony-stimulating factor (GM-CSF) plus PAF, caused translocation of preformed TF to the eosinophil cell membrane. GM-CSF/PAF also increased the TF transcript levels. The activated eosinophils exhibited procoagulant activity that was abrogated by TF inhibition. Targeting the extracellular domain of TF with specific antibodies markedly suppressed the initial phase of the eosinophil passage across the IL-4-activated endothelium. Eosinophil rolling and firm adhesion remained unaffected. This suggests that TF specifically facilitates the early transendothelial migration of the eosinophils. In summary, eosinophils maintain a high TF expression during maturation, providing a main source of preformed TF in blood, which might be relevant for the thrombogenesis promoted by hypereosinophilic conditions.
Publication
Journal: Nature
April/29/1993
Abstract
The U6 small nuclear (sn)RNA gene (SNR6) from the yeast Saccharomyces cerevisiae is transcribed by RNA polymerase III in vivo. This gene is unusual in having a TATA box at position -30, and an essential B-block element located downstream of the T-rich termination signal. The B block is one of the two intragenic promoter elements of transfer RNA genes that are recognized by transcription factor (TF)IIIC (ref. 4). But accurate in vitro transcription of yeast U6 snRNA gene by PolIII in a purified system requires only TFIIIB components, including the TATA-box binding protein TBP. Here we report that, after nucleosome reconstitution or chromatin assembly, U6 snRNA synthesis becomes dependent on TFIIIC and on the integrity of the B-block element. This observation resolves an apparent paradox between in vitro and in vivo results concerning the necessity of the downstream B-block element and sheds light on a new role of TFIIIC in gene activation.
Publication
Journal: Allergy: European Journal of Allergy and Clinical Immunology
January/22/2015
Abstract
BACKGROUND
Allergen immunotherapy (AIT) has been thoroughly documented in randomized controlled trials (RCTs). It is the only immune-modifying and causal treatment available for patients suffering from IgE-mediated diseases such as allergic rhinoconjunctivitis, allergic asthma and insect sting allergy. However, there is a high degree of clinical and methodological heterogeneity among the endpoints in clinical studies on AIT, for both subcutaneous and sublingual immunotherapy (SCIT and SLIT). At present, there are no commonly accepted standards for defining the optimal outcome parameters to be used for both primary and secondary endpoints.
METHODS
As elaborated by a Task Force (TF) of the European Academy of Allergy and Clinical Immunology (EAACI) Immunotherapy Interest Group, this Position Paper evaluates the currently used outcome parameters in different RCTs and also aims to provide recommendations for the optimal endpoints in future AIT trials for allergic rhinoconjunctivitis.
RESULTS
Based on a thorough literature review, the TF members have outlined recommendations for nine domains of clinical outcome measures. As the primary outcome, the TF recommends a homogeneous combined symptom and medication score (CSMS) as a simple and standardized method that balances both symptoms and the need for antiallergic medication in an equally weighted manner. All outcomes, grouped into nine domains, are reviewed.
CONCLUSIONS
A standardized and globally harmonized method for analysing the clinical efficacy of AIT products in RCTs is required. The EAACI TF highlights the CSMS as the primary endpoint for future RCTs in AIT for allergic rhinoconjunctivitis.
Publication
Journal: Journal of Thrombosis and Haemostasis
December/25/2012
Abstract
BACKGROUND
The procoagulant properties of microparticles (MPs) are due to the of the presence of phosphatidylserine (PS) and tissue factor (TF) on their surface. The latter has been demonstrated especially on MPs derived from monocytes.
OBJECTIVE
To investigate the relative contribution of TF and factor (F)XII in initiating coagulation on MPs derived from monocytes, platelets and erythrocytes.
METHODS
Microparticles were isolated from calcium ionophore-stimulated platelets, erythrocytes and monocytic THP-1 cells. MPs were quantified, characterized for cell-specific antigens and analyzed for TF, PS exposure and their thrombin-generating potential.
RESULTS
The MP number was not proportional to PS exposure and the majority of the MPs exposed PS. TF activity was undetectable on platelet- and erythrocyte-derived MPs (< 1 fM nM(-1) PS), whereas monocyte-derived MPs exposed TF (32 fM nM(-1) PS). Platelet-, erythrocyte- and monocyte-derived MPs, but not purified phospholipids, initiated thrombin generation in normal plasma in the absence of an external trigger (lag time < 11 min). Deficiency or inhibition of FVII had no effect on thrombin generation induced by platelet- and erythrocyte-derived MPs, but interfered with monocyte MP-triggered coagulation. Platelet- and erythrocyte-derived MPs completely failed to induce thrombin generation in FXII-deficient plasma. In contrast, monocyte-derived MPs induced similar thrombin generation in normal vs. FXII-deficient plasma.
CONCLUSIONS
MPs from platelets and erythrocytes not only propagate coagulation by exposing PS but also initiate thrombin generation independently of TF in a FXII-dependent manner. In contrast, monocyte-derived MPs trigger coagulation predominantly via TF.
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