scholarly journals Inferring transcriptional regulators through integrative modeling of public chromatin accessibility and ChIP-seq data

2019 ◽  
Author(s):  
Qian Qin ◽  
Jingyu Fan ◽  
Rongbin Zheng ◽  
Changxin Wan ◽  
Shenglin Mei ◽  
...  
Keyword(s):  
Binding Sites ◽  
In Silico ◽  
Transcriptional Regulators ◽  
Chromatin Accessibility ◽  
Histone Mark ◽  
Differentially Expressed ◽  
Alternative Methods ◽  
Input Gene ◽  
Integrative Modeling ◽  
Gene Sets

AbstractWe developed Lisa (http://lisa.cistrome.org) to predict the transcriptional regulators (TRs) of differentially expressed or co-expressed gene sets. Based on the input gene sets, Lisa first uses compendia of public histone mark ChIP-seq and chromatin accessibility profiles to construct a chromatin model related to the regulation of these genes. Then using TR ChIP-seq peaks or imputed TR binding sites, Lisa probes the chromatin models using in silico deletion to find the most relevant TRs. Applied to gene sets derived from targeted TF perturbation experiments, Lisa boosted the performance of imputed TR cistromes, and outperformed alternative methods in identifying the perturbed TRs.

scholarly journals Lisa: inferring transcriptional regulators through integrative modeling of public chromatin accessibility and ChIP-seq data

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Qian Qin ◽  
Jingyu Fan ◽  
Rongbin Zheng ◽  
Changxin Wan ◽  
Shenglin Mei ◽  
...  
Keyword(s):  
Transcriptional Regulators ◽  
Chromatin Accessibility ◽  
Integrative Modeling

Gene Set Correlation Analysis and Visualization Using Gene Expression Data

2020 ◽  
Vol 15 ◽  
Author(s):  
Chen-An Tsai ◽  
James J. Chen
Keyword(s):  
Gene Expression ◽  
Correlation Analysis ◽  
Gene Expression Data ◽  
Differentially Expressed Gene ◽  
Differentially Expressed ◽  
Superior Performance ◽  
Expression Data ◽  
Gene Set ◽  
Gene Sets ◽  
Set Correlation

Background: Gene set enrichment analyses (GSEA) provide a useful and powerful approach to identify differentially expressed gene sets with prior biological knowledge. Several GSEA algorithms have been proposed to perform enrichment analyses on groups of genes. However, many of these algorithms have focused on identification of differentially expressed gene sets in a given phenotype. Objective: In this paper, we propose a gene set analytic framework, Gene Set Correlation Analysis (GSCoA), that simultaneously measures within and between gene sets variation to identify sets of genes enriched for differential expression and highly co-related pathways. Methods: We apply co-inertia analysis to the comparisons of cross-gene sets in gene expression data to measure the costructure of expression profiles in pairs of gene sets. Co-inertia analysis (CIA) is one multivariate method to identify trends or co-relationships in multiple datasets, which contain the same samples. The objective of CIA is to seek ordinations (dimension reduction diagrams) of two gene sets such that the square covariance between the projections of the gene sets on successive axes is maximized. Simulation studies illustrate that CIA offers superior performance in identifying corelationships between gene sets in all simulation settings when compared to correlation-based gene set methods. Result and Conclusion: We also combine between-gene set CIA and GSEA to discover the relationships between gene sets significantly associated with phenotypes. In addition, we provide a graphical technique for visualizing and simultaneously exploring the associations of between and within gene sets and their interaction and network. We then demonstrate integration of within and between gene sets variation using CIA and GSEA, applied to the p53 gene expression data using the c2 curated gene sets. Ultimately, the GSCoA approach provides an attractive tool for identification and visualization of novel associations between pairs of gene sets by integrating co-relationships between gene sets into gene set analysis.

scholarly journals The MarR-Type Regulator PA3458 Is Involved in Osmoadaptation Control in Pseudomonas aeruginosa

2021 ◽  
Vol 22 (8) ◽  
pp. 3982
Author(s):  
Karolina Kotecka ◽  
Adam Kawalek ◽  
Kamil Kobylecki ◽  
Aneta Agnieszka Bartosik
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Binding Sites ◽  
Transcriptional Profiling ◽  
Mrna Level ◽  
Transcriptional Regulators ◽  
Resistance Mechanisms ◽  
Chronic Infections ◽  
Environmental Signals ◽  
Regulatory Systems

Pseudomonas aeruginosa is a facultative human pathogen, causing acute and chronic infections that are especially dangerous for immunocompromised patients. The eradication of P. aeruginosa is difficult due to its intrinsic antibiotic resistance mechanisms, high adaptability, and genetic plasticity. The bacterium possesses multilevel regulatory systems engaging a huge repertoire of transcriptional regulators (TRs). Among these, the MarR family encompasses a number of proteins, mainly acting as repressors, which are involved in response to various environmental signals. In this work, we aimed to decipher the role of PA3458, a putative MarR-type TR from P. aeruginosa. Transcriptional profiling of P. aeruginosa PAO1161 overexpressing PA3458 showed changes in the mRNA level of 133 genes; among them, 100 were down-regulated, suggesting the repressor function of PA3458. Concomitantly, ChIP-seq analysis identified more than 300 PA3458 binding sites in P. aeruginosa. The PA3458 regulon encompasses genes involved in stress response, including the PA3459–PA3461 operon, which is divergent to PA3458. This operon encodes an asparagine synthase, a GNAT-family acetyltransferase, and a glutamyl aminopeptidase engaged in the production of N-acetylglutaminylglutamine amide (NAGGN), which is a potent bacterial osmoprotectant. We showed that PA3458-mediated control of PA3459–PA3461 expression is required for the adaptation of P. aeruginosa growth in high osmolarity. Overall, our data indicate that PA3458 plays a role in osmoadaptation control in P. aeruginosa.

scholarly journals GATA2 regulates mast cell identity and responsiveness to antigenic stimulation by promoting chromatin remodeling at super-enhancers

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yapeng Li ◽  
Junfeng Gao ◽  
Mohammad Kamran ◽  
Laura Harmacek ◽  
Thomas Danhorn ◽  
...  
Keyword(s):  
Mast Cell ◽  
Binding Sites ◽  
Cell Lineage ◽  
Allergic Inflammation ◽  
Chromatin Accessibility ◽  
Antigenic Stimulation ◽  
Parasitic Infections ◽  
Cell Identity ◽  
Super Enhancer ◽  
Determining Factors

AbstractMast cells are critical effectors of allergic inflammation and protection against parasitic infections. We previously demonstrated that transcription factors GATA2 and MITF are the mast cell lineage-determining factors. However, it is unclear whether these lineage-determining factors regulate chromatin accessibility at mast cell enhancer regions. In this study, we demonstrate that GATA2 promotes chromatin accessibility at the super-enhancers of mast cell identity genes and primes both typical and super-enhancers at genes that respond to antigenic stimulation. We find that the number and densities of GATA2- but not MITF-bound sites at the super-enhancers are several folds higher than that at the typical enhancers. Our studies reveal that GATA2 promotes robust gene transcription to maintain mast cell identity and respond to antigenic stimulation by binding to super-enhancer regions with dense GATA2 binding sites available at key mast cell genes.

In silico strategies for modeling RNA aptamers and predicting binding sites of their molecular targets

2021 ◽  
pp. 1-10
Author(s):  
Alejandro Escamilla-Gutiérrez ◽  
Rosa María Ribas-Aparicio ◽  
María Guadalupe Córdova-Espinoza ◽  
Juan Arturo Castelán-Vega
Keyword(s):  
Binding Sites ◽  
In Silico ◽  
Molecular Targets ◽  
Rna Aptamers

scholarly journals Transcriptional survey of alveolar macrophages in a murine model of chronic granulomatous inflammation reveals common themes with human sarcoidosis

2018 ◽  
Vol 314 (4) ◽  
pp. L617-L625 ◽  
Author(s):  
Arjun Mohan ◽  
Anagha Malur ◽  
Matthew McPeek ◽  
Barbara P. Barna ◽  
Lynn M. Schnapp ◽  
...  
Keyword(s):  
Differentially Expressed Genes ◽  
Murine Model ◽  
Alveolar Macrophages ◽  
Gene Set Enrichment Analysis ◽  
Differentially Expressed ◽  
Multiwall Carbon Nanotube ◽  
Gene Set Enrichment ◽  
Integrated Network ◽  
Gene Set ◽  
Gene Sets

To advance our understanding of the pathobiology of sarcoidosis, we developed a multiwall carbon nanotube (MWCNT)-based murine model that shows marked histological and inflammatory signal similarities to this disease. In this study, we compared the alveolar macrophage transcriptional signatures of our animal model with human sarcoidosis to identify overlapping molecular programs. Whole genome microarrays were used to assess gene expression of alveolar macrophages in six MWCNT-exposed and six control animals. The results were compared with the transcriptional profiles of alveolar immune cells in 15 sarcoidosis patients and 12 healthy humans. Rigorous statistical methods were used to identify differentially expressed genes. To better elucidate activated pathways, integrated network and gene set enrichment analysis (GSEA) was performed. We identified over 1,000 differentially expressed between control and MWCNT mice. Gene ontology functional analysis showed overrepresentation of processes primarily involved in immunity and inflammation in MCWNT mice. Applying GSEA to both mouse and human samples revealed upregulation of 92 gene sets in MWCNT mice and 142 gene sets in sarcoidosis patients. Commonly activated pathways in both MWCNT mice and sarcoidosis included adaptive immunity, T-cell signaling, IL-12/IL-17 signaling, and oxidative phosphorylation. Differences in gene set enrichment between MWCNT mice and sarcoidosis patients were also observed. We applied network analysis to differentially expressed genes common between the MWCNT model and sarcoidosis to identify key drivers of disease. In conclusion, an integrated network and transcriptomics approach revealed substantial functional similarities between a murine model and human sarcoidosis particularly with respect to activation of immune-specific pathways.

The search of CAR, AhR, ESRs binding sites in promoters of intronic and intergenic microRNAs

2018 ◽  
Vol 16 (01) ◽  
pp. 1750029 ◽  
Author(s):  
Vladimir Y. Ovchinnikov ◽  
Denis V. Antonets ◽  
Lyudmila F. Gulyaeva
Keyword(s):  
Transcriptional Activation ◽  
Binding Sites ◽  
In Silico ◽  
Target Genes ◽  
Nuclear Translocation ◽  
Regulation Of Gene Expression ◽  
Experimental Studies ◽  
Transcriptional Level ◽  
Aryl Hydrocarbon ◽  
Exogenous Compounds

MicroRNAs (miRNAs) play important roles in the regulation of gene expression at the post-transcriptional level. Many exogenous compounds or xenobiotics may affect microRNA expression. It is a well-established fact that xenobiotics with planar structure like TCDD, benzo(a)pyrene (BP) can bind aryl hydrocarbon receptor (AhR) followed by its nuclear translocation and transcriptional activation of target genes. Another chemically diverse group of xenobiotics including phenobarbital, DDT, can activate the nuclear receptor CAR and in some cases estrogen receptors ESR1 and ESR2. We hypothesized that such chemicals can affect miRNA expression through the activation of AHR, CAR, and ESRs. To prove this statement, we used in silico methods to find DRE, PBEM, ERE potential binding sites for these receptors, respectively. We have predicted AhR, CAR, and ESRs binding sites in 224 rat, 201 mouse, and 232 human promoters of miRNA-coding genes. In addition, we have identified a number of miRNAs with predicted AhR, CAR, and ESRs binding sites that are known as oncogenes and as tumor suppressors. Our results, obtained in silico, open a new strategy for ongoing experimental studies and will contribute to further investigation of epigenetic mechanisms of carcinogenesis.

Abstract 121: Pro-inflammatory Cytokine Ifng Modulates Hepatic Sortilin Expression and Lipid Metabolism.

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
John Pirault ◽  
Konstantinos Polyzos ◽  
Daniel F Ketelhuth ◽  
Göran K Hansson
Keyword(s):  
Lipid Metabolism ◽  
Binding Sites ◽  
In Silico ◽  
In Silico Analysis ◽  
Lipid Uptake ◽  
Regulatory T Lymphocytes ◽  
Inflammatory Conditions ◽  
Ldl Particles ◽  
Inflammatory Milieu

Rationale: Hypercholesterolemia and immunity are two major risk factors for cardiovascular diseases (CVDs). Yet, we reported increased atherosclerosis upon depletion of regulatory T lymphocytes (Tregs). The effect was associated with increased hepatic inflammation and reduction of Sortilin expression and lipid uptake in the liver. Objective: To define how inflammatory milieu in the liver can modulate Sortilin and lipid metabolism. Methods: To reproduce the inflammatory milieu, hepatocytes (AML-12) were treated in vitro with IFNg. Expression of genes and proteins of interest were followed by qPCR and western blot. In silico method was used to find binding sites of signal transducer and activator of transcription (STAT1) on Sortilin, confirmed later by chromatin immune precipitation assays (Chip). Lipid uptake by hepatocytes was assessed via incubation of cells with radioactive lipoproteins. Results: Culture of AML-12 cells with IFNg induced the phosphorylation of STAT1 showing an active signaling pathway. In the same inflammatory conditions, Sort1 mRNA is decreased meanwhile its inhibitor (Atf3) expression is increased. Kinetic experiments revealed the reduction of Sortilin after 12 hours of culture, suggesting a post-transcriptional regulation of Sort1 by STAT1. In silico analysis revealed putative binding sites for STAT1 on Sortilin gene which was confirmed by chromatin immunoprecipitation assay (Chip). IFNg treated hepatocytes that were incubated with radioactive lipoproteins demonstrated a reduced uptake capacity of VLDL and LDL particles compared to control cultures. Conclusion: All together, these results suggest that inflammation through production of IFNg is able to directly modulate the lipid metabolism in hepatocytes by acting on Sortilin expression.

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