scholarly journals MicroRNAs overexpressed in Crohn’s disease and their interactions with mechanisms of epigenetic regulation explain novel aspects of Crohn’s disease pathogenesis

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Cecilia Fernández-Ponce ◽  
Roberto Navarro Quiroz ◽  
Anderson Díaz Perez ◽  
Gustavo Aroca Martinez ◽  
Andrés Cadena Bonfanti ◽  
...  
Keyword(s):  
Gene Expression ◽  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Relative Abundance ◽  
Gene Expression Regulation ◽  
R Package ◽  
Epigenetic Modifications ◽  
Integrated Analysis ◽  
Epigenetic Mechanisms ◽  
Gut Mucosa

Abstract Background In this review, we were interested to identify the wide universe of enzymes associated with epigenetic modifications, whose gene expression is regulated by miRNAs with a high relative abundance in Crohn's disease (CD) affected tissues, with the aim to determine their impact in the pathogenesis and evolution of the disease. Methods We used HMDD and Bibliometrix R-package in order to identify the miRNAs overexpressed in CD. The identified enzymes associated with epigenetic mechanisms and post-translational modifications, regulated by miRNAs upregulated in CD, were analyzed using String v11 database. Results We found 190 miRNAs with great abundance in patients with CD, of which 26 miRNAs regulate the gene expression of enzymes known to catalyze epigenetic modifications involved in essentials pathophysiological processes, such as chromatin architecture reorganization, immune response regulation including CD4+ T cells polarization, integrity of gut mucosa, gut microbiota composition and tumorigenesis. Conclusion The integrated analysis of miRNAs with a high relative abundance in patients with CD showed a combined and superimposed gene expression regulation of enzymes associated with relevant epigenetic mechanisms and that could explain, in part, the pathogenesis of CD.

scholarly journals Identification of key genes and pathways associated with Crohn’s disease by bioinformatics analysis

2019 ◽  
Author(s):  
Zheng Wang ◽  
Jie Zhu ◽  
Lixian Ma
Keyword(s):  
Gene Expression ◽  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Signaling Pathways ◽  
Bioinformatics Analysis ◽  
Integrated Analysis ◽  
Functional Modules ◽  
Disease Pathogenesis ◽  
Black Module ◽  
Key Genes

AbstractCrohn’s disease is a type of inflammatory bowel disease posing a significant threat to human health all over the world. Genome-wide gene expression profiles of mucosal colonic biopsies have provided some insight into the molecular mechanisms of Crohn’s disease. However, the exact pathogenesis is unclear. This study aimed to identify key genes and significant signaling pathways associated with Crohn’s disease by bioinformatics analysis. To identify key genes, an integrated analysis of gene expression signature was conducted using a robust rank aggregation approach. A total of 179 Crohn’s disease patients and 94 healthy controls from nine public microarray datasets were included. MMP1 and CLDN8 were two key genes screened from the differentially expressed genes. Connectivity Map predicted several small molecules as possible adjuvant drugs to treat CD. Besides, we used weighted gene co-expression network analysis to explore the co-expression modules associated with Crohn’s disease pathogenesis. Seven main functional modules were identified, of which black module showed the highest correlation with Crohn’s disease. The genes in black module mainly enriched in Interferon Signaling and defense response to virus. Blue module was another important module and enriched in several signaling pathways, including extracellular matrix organization, inflammatory response and blood vessel development. There were also several other meaningful functional modules which enriched in many biological processes. The present study identified a number of key genes and pathways correlated with Crohn’s disease and potential drugs to combat it, which might offer insights into Crohn’s disease pathogenesis and provide a clue to potential treatments.

scholarly journals Leveraging epigenetics to enhance the efficacy of immunotherapy

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Jonathan D. Licht ◽  
Richard L. Bennett
Keyword(s):  
Gene Expression ◽  
Clinical Trials ◽  
Antigen Presentation ◽  
Tumor Cells ◽  
Immune Evasion ◽  
Regulatory Elements ◽  
Chromatin Accessibility ◽  
Epigenetic Modifications ◽  
Main Body ◽  
Epigenetic Mechanisms

Abstract Background Epigenetic mechanisms regulate chromatin accessibility patterns that govern interaction of transcription machinery with genes and their cis-regulatory elements. Mutations that affect epigenetic mechanisms are common in cancer. Because epigenetic modifications are reversible many anticancer strategies targeting these mechanisms are currently under development and in clinical trials. Main body Here we review evidence suggesting that epigenetic therapeutics can deactivate immunosuppressive gene expression or reprogram tumor cells to activate antigen presentation mechanisms. In addition, the dysregulation of epigenetic mechanisms commonly observed in cancer may alter the immunogenicity of tumor cells and effectiveness of immunotherapies. Conclusions Therapeutics targeting epigenetic mechanisms may be helpful to counter immune evasion and improve the effectiveness of immunotherapies.

scholarly journals Epigenetic mechanisms in sexual differentiation of the brain and behaviour

2016 ◽  
Vol 371 (1688) ◽  
pp. 20150114 ◽  
Author(s):  
Nancy G. Forger
Keyword(s):  
Gene Expression ◽  
Sex Differences ◽  
Sexual Differentiation ◽  
Wide Distribution ◽  
Epigenetic Modifications ◽  
Epigenetic Mechanism ◽  
Epigenetic Mechanisms ◽  
Genome Wide ◽  
The Brain

Circumstantial evidence alone argues that the establishment and maintenance of sex differences in the brain depend on epigenetic modifications of chromatin structure. More direct evidence has recently been obtained from two types of studies: those manipulating a particular epigenetic mechanism, and those examining the genome-wide distribution of specific epigenetic marks. The manipulation of histone acetylation or DNA methylation disrupts the development of several neural sex differences in rodents. Taken together, however, the evidence suggests there is unlikely to be a simple formula for masculine or feminine development of the brain and behaviour; instead, underlying epigenetic mechanisms may vary by brain region or even by dependent variable within a region. Whole-genome studies related to sex differences in the brain have only very recently been reported, but suggest that males and females may use different combinations of epigenetic modifications to control gene expression, even in cases where gene expression does not differ between the sexes. Finally, recent findings are discussed that are likely to direct future studies on the role of epigenetic mechanisms in sexual differentiation of the brain and behaviour.

scholarly journals P076 A gene expression outlier strategy towards identifying molecular causes of Crohn's disease

2012 ◽  
Vol 6 ◽  
pp. S41
Author(s):  
G.W. Sewell ◽  
P.J. Smith ◽  
A.P. Levine ◽  
C.M. McDonald ◽  
S.L. Bloom ◽  
...  
Keyword(s):  
Gene Expression ◽  
Crohn’S Disease ◽  
Crohn's Disease

scholarly journals ZBTB6 is hyper-methylated and differentially expressed in the blood of patients with Crohn’s disease.

2020 ◽  
Author(s):  
Shahan Mamoor
Keyword(s):  
Gene Expression ◽  
Crohn’S Disease ◽  
Crohn's Disease ◽  
The United States ◽  
Differentially Expressed ◽  
Economic Productivity ◽  
Unbiased Manner ◽  
Inflammatory Bowel ◽  
Disease Analysis ◽  
Broad Complex

Crohn’s disease, an inflammatory bowel disease of the gastrointestinal tract (1), causes significant morbidity and nearly 3.5 billion dollars in lost economic productivity in the United States (2) due to complications of the disease. We mined transcriptome and methylome datasets (3, 4) to understand, in an unbiased manner, the most significant changes in gene expression and DNA methylation in the hematopoietic system of patients with Crohn’s disease (CD). We identified the zinc finger and BTB (broad complex, tramtrack, bric-à-brac) domain-containing gene ZBTB6 (5, 6) as one of the most differentially expressed genes in the whole blood of patients with Crohn’s disease. Analysis of a separate data revealed that the ZBTB6 locus was one of the most differentially methylated sites globally in the blood of patients with Crohn’s disease when compared to the blood of healthy patients. ZBTB6 is differentially methylated and differentially expressed in the blood of patients with Crohn’s disease, and more significantly so than the vast majority of the human genome. These data point to inhibition of ZBTB6 gene expression by hyper-methylation of the ZBTB6 locus and suggest that titration of some function or transcriptional target of ZBTB6 may be an important event in the pathogenesis of Crohn’s disease.

IDENTIFYING RELEVANT PATHWAYS AND BIOMARKERS IN CROHN’S DISEASE USING CONTEXTUALIZED METABOLIC NETWORK MODEL

2021 ◽  
Vol 27 (Supplement_1) ◽  
pp. S9-S10
Author(s):  
Brooklyn McGrew ◽  
Aman Shrivastava ◽  
Philip Fernandes ◽  
Lubaina Ehsan ◽  
Yash Sharma ◽  
...  
Keyword(s):  
Gene Expression ◽  
Crohn’S Disease ◽  
Fatty Acid ◽  
Crohn's Disease ◽  
Fatty Acid Synthesis ◽  
Metabolic Pathway ◽  
Metabolic Pathways ◽  
Acid Synthesis ◽  
Transcriptomic Data ◽  
Context Specific

Abstract Background Candidate markers for Crohn’s Disease (CD) may be identified via gene expression-based construction of metabolic networks (MN). These can computationally describe gene-protein-reaction associations for entire tissues and also predict the flux of reactions (rate of turnover of specific molecules via a metabolic pathway). Recon3D is the most comprehensive human MN to date. We used publicly available CD transcriptomic data along with Recon3D to identify metabolites as potential diagnostic and prognostic biomarkers. Methods Terminal ileal gene expression profiles (36,372 genes; 218 CD. 42 controls) from the RISK cohort (Risk Stratification and Identification of Immunogenetic and Microbial Markers of Rapid Disease Progression in Children with Crohn’s Disease) and their transcriptomic abundances were used. Recon3D was pruned to only include RISK dataset transcripts which determined metabolic reaction linkage with transcriptionally active genes. Flux balance analysis (FBA) was then run using RiPTiDe with context specific transcriptomic data to further constrain genes (Figure 1). RiPTiDe was independently run on transcriptomic data from both CD and controls. From the pruned and constricted MN obtained, reactions were extracted for further analysis. Results After applying the necessary constraints to modify Recon3D, 527 CD and 537 control reactions were obtained. Reaction comparison with a publicly available list of healthy small intestinal epithelial reactions (n=1282) showed an overlap of 80 CD and 84 control reactions. These were then further grouped based on their metabolic pathways. RiPTiDe identified context specific metabolic pathway activity without supervision and the percentage of forward, backward, and balanced reactions for each metabolic pathway (Figure 2). The metabolite concentrations in the small intestine was altered among CD patients. Notably, the citric acid cycle and malate-aspartate shuttle were affected, highlighting changes in mitochondrial metabolic pathways. This is illustrated by changes in the number of reactions at equilibrium between CD and control. Conclusions The results are relevant as cytosolic acetyl-CoA is needed for fatty acid synthesis and is obtained by removing citrate from the citric acid cycle. An intermediate removal from the cycle has significant cataplerotic effects. The malate-aspartate shuttle also allows electrons to move across the impermeable membrane in the mitochondria (fatty acid synthesis location). These findings are reported by previously published studies where gene expression for fatty acid synthesis is altered in CD patients along with mitochondrial metabolic pathway changes, resulting in altered cell homeostasis. In-depth analysis is currently underway with our work supporting the utility of potential metabolic biomarkers for CD diagnosis, management and improved care.

scholarly journals P014 Identification of Crohn’s disease immunopathotypes

2020 ◽  
Vol 14 (Supplement_1) ◽  
pp. S137-S137
Author(s):  
H M Baer ◽  
E MacDonald ◽  
A Ferguson ◽  
A M Scott ◽  
M I Khan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Immune Response ◽  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Immune Responses ◽  
Mononuclear Cells ◽  
Local Immune Response ◽  
Cross Sectional ◽  
Treatment Responses ◽  
Colonic Biopsies

Abstract Background Crohn’s disease (CD) is a chronic inflammatory gastrointestinal condition, with globally increasing incidence. Patients with CD suffer from a loss of tolerance towards their commensal microbiota causing an aberrant immune response, occurring in a protracted relapse and remission cycle. Although a variety of frontline therapies is currently available, including targeted therapies such as biologic drugs, 30–40% of CD patients still require surgery to manage the disease. At present, the immunobiology of CD is not fully understood. However, differences in immune responses between patients might play an important role in diverse treatment responses. The aim of this study was to identify differences in peripheral and local immune responses of CD to understand differences in disease behaviour and treatment outcome. Methods Peripheral blood mononuclear cells and plasma were isolated from whole blood of a cross-sectional CD patient cohort (nCD = 12) and normal controls (NC, nNC = 28). Flow cytometry analysis and multiplex assays were used to quantify immune cell populations and cytokine levels, respectively. The local immune response was analysed by bulk RNA sequencing of mucosal colonic biopsies either from inflamed CD or normal tissue. Gene signatures were then followed up by validation in publicly deposited gene expression datasets (nCD = 36, nNC = 24), and by measurement of specific proteins using our archived samples. Results Peripheral immunophenotyping of the initial cross-sectional study displayed three different types of CD patients, characterised by either a decrease in leukocyte populations, an increase of cytokines, or a change in both. Analysis of the RNAseq data derived from colonic biopsies revealed four distinct clusters in genes associated with the immune response in CD patients. Further pathway analysis showed one cluster with an enriched B cell signature and another cluster with an elevated macrophage and neutrophil response. We utilised publicly available gene expression datasets to validate these signatures in a larger cohort and identified a selection of patients with an up-regulated pro-inflammatory macrophage response. Using correlation analysis, we suggest an immunopathotype with increased macrophage activation which is potentially associated with a more severe form of the disease. Conclusion We have identified distinct immunopathotypes in both the peripheral and local immune response of CD patients. Further investigation will correlate these distinct immune responses in CD with clinical parameters, to understand associations between diverse treatment responses and disease behaviours.

scholarly journals Decreased Enteric Bacterial Composition and Diversity in South American Crohn’s Disease Vary With the Choice of Treatment Strategy and Time Since Diagnosis

2019 ◽  
Vol 14 (6) ◽  
pp. 791-800
Author(s):  
Angélica Cruz-Lebrón ◽  
Leticia D’argenio Garcia ◽  
Aarthi Talla ◽  
Samira Joussef-Piña ◽  
Miguel E Quiñones-Mateu ◽  
...  
Keyword(s):  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Gut Microbiota ◽  
Bacterial Diversity ◽  
Relative Abundance ◽  
Treatment Strategy ◽  
Chronic Inflammatory Disease ◽  
Rrna Gene ◽  
Faecal Calprotectin ◽  
Time Since Diagnosis

Abstract Background and Aims The symptomology of Crohn’s disease [CD], a chronic inflammatory disease of the digestive tract, correlates poorly with clinical, endoscopic or immunological assessments of disease severity. The prevalence of CD in South America is rising, reflecting changes in socio-economic stability. Many treatment options are available to CD patients, including biological agents and corticosteroids, each of which offers variable efficacy attributed to host genetics and environmental factors associated with alterations in the gut microbiota. Methods Based on 16S rRNA gene sequencing and taxonomic differences, we compared the faecal microbial population of Brazilian patients with CD treated with corticosteroid or anti-tumour necrosis factor [anti-TNF] immunotherapy. Faecal calprotectin and plasma sCD14 levels were quantified as markers for local and systemic inflammation, respectively. Results Anti-TNF treatment led to an increased relative abundance of Proteobacteria and a decreased level of Bacteroidetes. In contrast, corticoid treatment was associated with an increase in the relative abundance of Actinobacteria, which has been linked to inflammation in CD. Disruption of the faecal microbiota was related to decreased bacterial diversity and composition. Moreover, the choice of clinical regimen and time since diagnosis modulate the character of the resulting dysbiosis. Conclusions Enteric microbial populations in CD patients who have been treated are modulated by disease pathogenesis, local inflammatory microenvironment and treatment strategy. The dysbiosis that remains after anti-TNF treatment due to decreased bacterial diversity and composition abates restoration of the microbiota to a healthy state, suggesting that the identification and development of new clinical treatments for CD must include their capacity to normalize the gut microbiota.

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