scholarly journals Partnership between epigenetic reader BRD4 and transcription factor CEBPD

2020 ◽  
Author(s):  
Qingwei Wang ◽  
Mengxue Zhang ◽  
Go Urabe ◽  
Bowen Wang ◽  
Hatice Gulcin Ozer ◽  
...  

AbstractVascular smooth muscle cell (SMC) state/phenotype transitions underlie neointimal hyperplasia (IH) predisposing to cardiovascular diseases. Bromodomain protein BRD4 is a histone acetylation reader and enhancer mark that co-activates transcription elongation. CCAAT enhancer binding protein delta (CEBPD) is a transcription factor typically studied in adipogenesis and immune cell differentiation. Here we investigated the association between BRD4 and CEBPD in SMC state transition.Chromatin immunoprecipitation sequencing (ChIPseq) showed enrichment of BRD4 and histone acetylation (H3K27ac) at Cebpd and enhancer in rat carotid arteries undergoing IH. In vitro, BRD4 silencing with siRNA reduced SMC expression of CEBPD. Bromodomain-1 but not bromodoamin-2 accounted for this BRD4 function. Endogenous BRD4 co-IP’ed with CEBPD; Cebpd promoter and enhancer DNA fragments co-IP’ed with CEBPD or endogenous BRD4 (ChIP-qPCR). These co-IPs were abolished by the BRD4 bromodomain blocker JQ1. TNFα upregulated both BRD4 and CEBPD. Silencing CEBPD averted TNFα-induced inflammatory SMC state transition (heightened IL-1β, IL6, and MCP-1 mRNA levels), so did JQ1. CEBPD overexpression increased PDGFRα preferentially over PDGFRβ; so did TNFα, and JQ1 abolished TNFα’s effect.Our data reveal a BRD4/CEBPD partnership that promotes CEBPD’s own transcription and inflammatory SMC state transition, thus shedding new light on epigenetic reader and transcription factor cooperative actions in SMC pathobiology.

2017 ◽  
Author(s):  
John Biddlestone ◽  
Michael Batie ◽  
Alena Shmakova ◽  
Daniel Bandarra ◽  
Elena V. Knatko ◽  
...  

AbstractThe SIN3A-HDAC complex is a master transcriptional repressor, required for development but often deregulated in disease. Here, we report that the recently identified new component of this complex, SINHCAF/FAM60A, links the SIN3A-HDAC co-repressor complex function to the hypoxia response. SINHCAF Chromatin Immunoprecipitation-sequencing and gene expression analysis reveal a signature associated with the activation of the hypoxia response. We show that SINHCAF specifically repress HIF 2α mRNA and protein expression resulting in functional cellular changes in in-vitro angiogenesis, and proliferation. Analysis of patient datasets demonstrates that SINHCAF and HIF 2α mRNA levels are inversely correlated and predict contrasting outcomes for patient survival in both colon and lung cancer. This relationship is also observed in a mouse model of colon cancer, indicating an evolutionary conserved mechanism. Our analysis reveals an unexpected link between SINHCAF and cancer cell signalling via regulation of the hypoxia response that is predictive of poor patient outcome.


2021 ◽  
Vol 11 ◽  
Author(s):  
Qiao Jin ◽  
Hao Hu ◽  
Siqi Yan ◽  
Long Jin ◽  
Yuliang Pan ◽  
...  

BackgroundWith the development of radiotherapy technology, radiotherapy has been increasingly used to treat primary hepatocellular carcinoma (HCC). However, due to radioresistance and the intolerance of the adjacent organs to radiation, the effects of radiotherapy are often unsatisfactory. Therefore, it is necessary to study radiosensitization in HCC.MethodA microarray was used to analyze the genes that were significantly associated with radiosensitivity. HCC cells, HepG2 and MHCC97H, were subjected to radiation in vitro. Real-time PCR was performed to determine MIR22HG (microRNA22 host gene) and miR-22-5p expression levels. Western blotting was performed to determine histone expression levels. A histone deacetylase (HDAC) whole cell assay was used to determine the activity of HDAC2. MTT, colony formation, 5-ethynyl-2′-deoxyuridine, and wound healing assays were performed to examine the function of MIR22HG and miR-22-5p in cellular radiosensitivity. Chromatin immunoprecipitation-PCR was used to confirm that HDAC2 affects the acetylation level of the MIR22HG promoter region. Finally, animal experiments were performed to demonstrate the in vivo effect of MIR22HG on the radiosensitivity of hepatoma.ResultsIrradiation can up-regulate MIR22HG expression and down-regulate HDAC2 expression. Inhibition of HDAC2 expression promotes histone acetylation in the MIR22HG promoter region and up-regulates MIR22HG expression. MIR22HG can increase radiosensitivity via miR-22-5p in HCC.ConclusionInhibition of HDAC2 expression promotes histone acetylation in the MIR22HG promoter region, thereby up-regulating the expression of MIR22HG and promoting the production of miR-22-5p, and ultimately increasing the sensitivity of liver cancer radiotherapy.


2021 ◽  
Author(s):  
Chao Du ◽  
Joost Willemse ◽  
Amanda M. Erkelens ◽  
Victor J. Carrion ◽  
Remus T. Dame ◽  
...  

ABSTRACTBacterial chromosome structure is organized by a diverse group of proteins collectively called nucleoid-associated proteins (NAPs). Many NAPs have been studied in detail in Streptomyces, including Lsr2, HupA, HupS, and sIHF. Here, we show that SCO1839 represents a novel family of small NAPs unique to Actinobacteria and recognizes a consensus sequence consisting of GATC followed by (A/T)T. The protein was designated Gbn for GATC-binding NAP. Chromatin immunoprecipitation sequencing (ChIP-Seq) detected more than 2800 binding regions, encompassing some 3600 GATCWT motifs, which comprise 55% of all motifs in the S. coelicolor genome. DNA binding of Gbn in vitro increased DNA stiffness but not compaction, suggesting a role in regulation rather than chromosome organization. Despite the huge number of binding sites, the DNA binding profiles were nearly identical during vegetative and aerial growth. The exceptions were SCO1311 and SCOt32, for a tRNA editing enzyme and a tRNA that recognises the rare leucine codon CUA, respectively, which were nearly exclusively bound during vegetative growth. Deletion of gbn led to pleiotropic alterations in developmental timing, morphogenesis and antibiotic production. Taken together, our data show that Gbn is a highly pleiotropic NAP that impacts growth and development in streptomycetes.


F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 372 ◽  
Author(s):  
Delasa Aghamirzaie ◽  
Karthik Raja Velmurugan ◽  
Shuchi Wu ◽  
Doaa Altarawy ◽  
Lenwood S. Heath ◽  
...  

Motivation: The increasing availability of chromatin immunoprecipitation sequencing (ChIP-Seq) data enables us to learn more about the action of transcription factors in the regulation of gene expression. Even though in vivo transcriptional regulation often involves the concerted action of more than one transcription factor, the format of each individual ChIP-Seq dataset usually represents the action of a single transcription factor. Therefore, a relational database in which available ChIP-Seq datasets are curated is essential. Results: We present Expresso (database and webserver) as a tool for the collection and integration of available Arabidopsis ChIP-Seq peak data, which in turn can be linked to a user’s gene expression data. Known target genes of transcription factors were identified by motif analysis of publicly available GEO ChIP-Seq data sets. Expresso currently provides three services: 1) Identification of target genes of a given transcription factor; 2) Identification of transcription factors that regulate a gene of interest; 3) Computation of correlation between the gene expression of transcription factors and their target genes. Availability: Expresso is freely available at http://bioinformatics.cs.vt.edu/expresso/


2019 ◽  
Author(s):  
Lilah Toker ◽  
Gia T Tran ◽  
Janani Sundaresan ◽  
Ole-Bjørn Tysnes ◽  
Guido Alves ◽  
...  

AbstractParkinson disease (PD) is a complex neurodegenerative disorder of largely unknown etiology. While several genetic risk factors have been identified, the involvement of epigenetics in the pathophysiology of PD is mostly unaccounted for. We conducted a histone acetylome-wide association study in PD, using brain tissue from two independent cohorts of cases and controls. Immunoblotting revealed increased acetylation at several histone sites in PD, with the most prominent change observed for H3K27, a marker of active promoters and enhancers. Chromatin immunoprecipitation sequencing (ChIP-seq) further indicated that H3K27 hyperacetylation in the PD brain is a genome-wide phenomenon, with a strong predilection for genes implicated in the disease, including SNCA, PARK7, PRKN and MAPT. Integration of the ChIP-seq with transcriptomic data revealed that the correlation between promoter H3K27 acetylation and gene expression is attenuated in PD patients, suggesting that H3K27 acetylation may be decoupled from transcription in the PD brain. Our findings strongly suggest that dysregulation of histone acetylation plays an important role in the pathophysiology of PD and identify novel epigenetic signatures associated with the disease.


Blood ◽  
2004 ◽  
Vol 104 (1) ◽  
pp. 89-91 ◽  
Author(s):  
Boris Guyot ◽  
Veronica Valverde-Garduno ◽  
Catherine Porcher ◽  
Paresh Vyas

Abstract Expression of the myeloid transcription factor GATA1 is required for early stages of eosinophil differentiation. Defining mechanisms regulating eosinophil GATA1 expression will be important to understand development of this lineage. However, the cis-elements required for eosinophil GATA1 expression are not fully characterized. Previous work identified HS 1 as a major GATA1 enhancer, but its role in eosinophil GATA1 expression is unclear. Here, we show that mouse HS 1 deletion leaves eosinophil GATA1 mRNA expression and eosinophil differentiation unaffected. Chromatin isolated from eosinophils and encompassing HS 1 is weakly enriched for acetylated histones H3/H4. HS 1 deletion does not alter eosinophil GATA1 locus histone acetylation. In eosinophils, GATA1 and CCAAT/enhancer binding protein ϵ (C/EBPϵ) do not bind HS 1 but bind selectively a cis-element in the first GATA1 intron. Thus, HS 1 is not required for eosinophil GATA1 expression. Instead, this study suggests a previously unsuspected role for the GATA1 intron element for this function.


2020 ◽  
Author(s):  
Wurihan Wurihan ◽  
Yi Zou ◽  
Alec M. Weber ◽  
Korri Weldon ◽  
Yehong Huang ◽  
...  

ABSTRACTThe obligate intracellular bacterium Chlamydia trachomatis is an important human pathogen whose biphasic developmental cycle consists of an infectious elementary body and a replicative reticulate body. Whereas σ66, the primary sigma factor, is necessary for transcription of most chlamydial genes throughout the developmental cycle, σ28 is required for expression of some late genes. We previously showed that the Chlamydia-specific transcription factor GrgA physically interacts with both of these sigma factors and activates transcription from σ66- and σ28-dependent promoters in vitro. Here, we investigate the organismal functions of GrgA. We show that GrgA overexpression decreased RB proliferation via time-dependent transcriptomic changes. Significantly, σ66-dependent genes that code for two important transcription repressors are among the direct targets of GrgA. One of these repressors is Euo, which prevents the expression of late genes during early phases. The other is HrcA, which regulates gene expression in response to heat shock. The direct regulon of GrgA also includes a σ28-dependent gene that codes for the putative virulence factor PmpI. Conditional overexpression of Euo and HrcA also inhibited chlamydial growth and affected GrgA expression. Transcriptomic studies suggest that GrgA, Euo, and HrcA have distinct but overlapping indirect regulons. Furthermore, overexpression of either GrgA leads to decreased expression of numerous tRNAs. These findings indicate that a GrgA-mediated transcriptional regulatory network controls C. trachomatis growth and development.IMPORTANCEChlamydia trachomatis is the most prevalent sexually transmitted bacterial pathogen worldwide and is a leading cause of preventable blindness in under-developed areas as well as developed countries. Previous studies showed that the novel transcription factor GrgA activated chlamydial gene transcription in vitro, but did not addressed the organismal function of GrgA. Here, we demonstrate growth inhibition in C. trachomatis engineered to conditionally overexpress GrgA. GrgA overexpression immediately increases the expression of two other critical transcription factors (Euo and HrcA) and a candidate virulence factor (PmpI), among several other genes. We also reveal chlamydial growth reduction and transcriptomic changes including decreased GrgA mRNA levels in response to either Euo or HrcA overexpression. Thus, the transcription network controlled by GrgA likely plays a crucial role in chlamydial growth and pathogenesis.


2018 ◽  
Vol 38 (5) ◽  
Author(s):  
Chen Zhang ◽  
Fei Wang ◽  
Qisheng Zuo ◽  
Changhua Sun ◽  
Jing Jin ◽  
...  

Spermatogonial stem cells (SSCs) may apply to gene therapy, regenerative medicine in place of embryonic stem cells (ESCs). However, the application of SSCs was severely limited by the low induction efficiency and the lack of thorough analysis of the regulatory mechanisms of SSCs formation. Current evidences have demonstrated multiple marker genes of germ cells, while genes that specifically regulate the formation of SSCs have not been explored. In our study, cadherin-like and PC-esterase domain containing 1 (Cped1) expressed specifically in SSCs based on RNA-seq data analysis. To study the function of Cped1 in the formation of SSCs, we successfully established a CRISPR/Cas9 knockout system. The gene disruption frequency is 37% in DF1 and 25% in ESCs without off-target effects. Knockout of Cped1 could significantly inhibit the formation of SSCs in vivo and in vitro. The fragment of −1050 to −1 bp had the activity as Cped1 gene promoter. Histone acetylation could regulate the expression of Cped1. We added 5-azaeytidi (DNA methylation inhibitors) and TSA (histone deacetylase inhibitors) respectively during the cultivation of SSCs. TSA was validated to promote the transcription of Cped1. Dual-luciferase reporter assay revealed that active control area of the chicken Cped1 gene is −296 to −1 bp. There are Cebpb, Sp1, and Sox2 transcription factor binding sites in this region. Point-mutation experiment results showed that Sox2 negatively regulates the transcription of Cped1. Above results demonstrated that Cped1 is a key gene that regulates the formation of SSCs. Histone acetylation and transcription factor Sox2 participate in the regulation of Cped1.


2019 ◽  
Author(s):  
Benjamin J.E. Martin ◽  
Julie Brind’Amour ◽  
Kristoffer N. Jensen ◽  
Anastasia Kuzmin ◽  
Zhen Cheng Liu ◽  
...  

AbstractHistone acetylation is a ubiquitous hallmark of transcriptional activity, but whether the link is of a causal or consequential nature is still a matter of debate. In this study we resolve this question. Using both immunoblot analysis and chromatin immunoprecipitation-sequencing (ChIP-seq) in S. cerevisiae, we show that the majority of histone acetylation is dependent on transcription. Loss of histone H4 acetylation upon transcription inhibition is partially explained by depletion of histone acetyltransferases (HATs) from gene bodies, implicating transcription in HAT targeting. Despite this, HAT occupancy alone poorly predicts histone acetylation, suggesting that HAT activity is regulated at a step post-recruitment. Collectively, these data show that the majority of histone acetylation is a consequence of RNAPII promoting both the recruitment and activity of histone acetyltransferases.


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