scholarly journals Genome-wide profiling of an enhancer-associated histone modification reveals the influence of asthma on the epigenome of the airway epithelium

2018 ◽  
Author(s):  
Peter McErlean ◽  
Audrey Kelly ◽  
Jaideep Dhariwal ◽  
Max Kirtland ◽  
Julie Watson ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Histone Modification ◽  
Molecular Mechanisms ◽  
Airway Disease ◽  
Epigenome Editing ◽  
Genome Wide ◽  
Genes Encoding ◽  
Chronic Airway Disease ◽  
Dynamic Relationships

AbstractAsthma is a chronic airway disease driven by complex genetic-environmental interactions. The role of epigenetic modifications in bronchial epithelial cells (BECs) in asthma is poorly understood. We undertook genome-wide profiling of the enhancer-associated histone modification H3K27ac in BECs from people with asthma and healthy controls. We identified 49,903 regions exhibiting differential H3K27ac enrichment in asthma, clustered at genes associated with type-2-high asthma (CLCA1) and epithelial processes (EMT). Asthma dramatically influenced the BEC enhancer landscape and we identified asthma-associated Super-Enhancers encompassing genes encoding transcription factors (TP63) and enzymes regulating lipid metabolism (NOX4). We integrated published protein, epigenomic and transcriptomic datasets and identified epithelium-specific transcription factors associated with H3K27ac in asthma (TP73) and dynamic relationships between asthma-associated changes in H3K27ac, DNA methylation, genetic susceptibility and transcriptional profiles. Finally, we used a CRISPR-based approach to recapitulate the H3K27ac-asthma landscape in vitro and provide proof of principal that asthma-associated gene expression (SERPINB2) is driven in part by aberrant histone acetylation, validating the combination of genome-wide and epigenome-editing approaches in deciphering the molecular mechanisms underlying asthma pathogenesis.

scholarly journals Profiling of H3K27Ac Reveals the Influence of Asthma on the Epigenome of the Airway Epithelium

2020 ◽  
Vol 11 ◽  
Author(s):  
Peter McErlean ◽  
Audrey Kelly ◽  
Jaideep Dhariwal ◽  
Max Kirtland ◽  
Julie Watson ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Airway Disease ◽  
Small Pilot Study ◽  
Guide Rnas ◽  
Environmental Interactions ◽  
Genome Wide ◽  
Genes Encoding ◽  
Chronic Airway Disease

BackgroundAsthma is a chronic airway disease driven by complex genetic–environmental interactions. The role of epigenetic modifications in bronchial epithelial cells (BECs) in asthma is poorly understood.MethodsWe piloted genome-wide profiling of the enhancer-associated histone modification H3K27ac in BECs from people with asthma (n = 4) and healthy controls (n = 3).ResultsWe identified n = 4,321 (FDR < 0.05) regions exhibiting differential H3K27ac enrichment between asthma and health, clustering at genes associated predominately with epithelial processes (EMT). We identified initial evidence of asthma-associated Super-Enhancers encompassing genes encoding transcription factors (TP63) and enzymes regulating lipid metabolism (PTGS1). We integrated published datasets to identify epithelium-specific transcription factors associated with H3K27ac in asthma (TP73) and identify initial relationships between asthma-associated changes in H3K27ac and transcriptional profiles. Finally, we investigated the potential of CRISPR-based approaches to functionally evaluate H3K27ac-asthma landscape in vitro by identifying guide-RNAs capable of targeting acetylation to asthma DERs and inducing gene expression (TLR3).ConclusionOur small pilot study validates genome-wide approaches for deciphering epigenetic mechanisms underlying asthma pathogenesis in the airways.

scholarly journals CRISPR Tools for Physiology and Cell State Changes: Potential of Transcriptional Engineering and Epigenome Editing

2021 ◽  
Vol 101 (1) ◽  
pp. 177-211
Author(s):  
Christopher T. Breunig ◽  
Anna Köferle ◽  
Andrea M. Neuner ◽  
Maximilian F. Wiesbeck ◽  
Valentin Baumann ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Molecular Mechanisms ◽  
New Technologies ◽  
Epigenome Editing ◽  
Dna Targeting ◽  
Genome Wide ◽  
Transcriptional Engineering ◽  
Genome Wide Data ◽  
Experimental Approaches ◽  
State Changes

Given the large amount of genome-wide data that have been collected during the last decades, a good understanding of how and why cells change during development, homeostasis, and disease might be expected. Unfortunately, the opposite is true; triggers that cause cellular state changes remain elusive, and the underlying molecular mechanisms are poorly understood. Although genes with the potential to influence cell states are known, the historic dependency on methods that manipulate gene expression outside the endogenous chromatin context has prevented us from understanding how cells organize, interpret, and protect cellular programs. Fortunately, recent methodological innovations are now providing options to answer these outstanding questions, by allowing to target and manipulate individual genomic and epigenomic loci. In particular, three experimental approaches are now feasible due to DNA targeting tools, namely, activation and/or repression of master transcription factors in their endogenous chromatin context; targeting transcription factors to endogenous, alternative, or inaccessible sites; and finally, functional manipulation of the chromatin context. In this article, we discuss the molecular basis of DNA targeting tools and review the potential of these new technologies before we summarize how these have already been used for the manipulation of cellular states and hypothesize about future applications.

scholarly journals Role of Satb1 and Satb2 Transcription Factors in the Glutamate Receptors Expression and Ca2+ Signaling in the Cortical Neurons In Vitro

2021 ◽  
Vol 22 (11) ◽  
pp. 5968
Author(s):  
Egor A. Turovsky ◽  
Maria V. Turovskaya ◽  
Evgeniya I. Fedotova ◽  
Alexey A. Babaev ◽  
Viktor S. Tarabykin ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Nmda Receptor ◽  
Cortical Neurons ◽  
Target Genes ◽  
Cortical Cell ◽  
Inhibitory System ◽  
Selective Agonist ◽  
Genes Encoding ◽  
Deficient Mice

Transcription factors Satb1 and Satb2 are involved in the processes of cortex development and maturation of neurons. Alterations in the expression of their target genes can lead to neurodegenerative processes. Molecular and cellular mechanisms of regulation of neurotransmission by these transcription factors remain poorly understood. In this study, we have shown that transcription factors Satb1 and Satb2 participate in the regulation of genes encoding the NMDA-, AMPA-, and KA- receptor subunits and the inhibitory GABA(A) receptor. Deletion of gene for either Satb1 or Satb2 homologous factors induces the expression of genes encoding the NMDA receptor subunits, thereby leading to higher amplitudes of Ca2+-signals in neurons derived from the Satb1-deficient (Satb1fl/+ * NexCre/+) and Satb1-null mice (Satb1fl/fl * NexCre/+) in response to the selective agonist reducing the EC50 for the NMDA receptor. Simultaneously, there is an increase in the expression of the Gria2 gene, encoding the AMPA receptor subunit, thus decreasing the Ca2+-signals of neurons in response to the treatment with a selective agonist (5-Fluorowillardiine (FW)). The Satb1 deletion increases the sensitivity of the KA receptor to the agonist (domoic acid), in the cortical neurons of the Satb1-deficient mice but decreases it in the Satb1-null mice. At the same time, the Satb2 deletion decreases Ca2+-signals and the sensitivity of the KA receptor to the agonist in neurons from the Satb1-null and the Satb1-deficient mice. The Satb1 deletion affects the development of the inhibitory system of neurotransmission resulting in the suppression of the neuron maturation process and switching the GABAergic responses from excitatory to inhibitory, while the Satb2 deletion has a similar effect only in the Satb1-null mice. We show that the Satb1 and Satb2 transcription factors are involved in the regulation of the transmission of excitatory signals and inhibition of the neuronal network in the cortical cell culture.

scholarly journals Dual RNA-Seq Analysis of Trichophyton rubrum and HaCat Keratinocyte Co-Culture Highlights Important Genes for Fungal-Host Interaction

Genes ◽  
2018 ◽  
Vol 9 (7) ◽  
pp. 362 ◽  
Author(s):  
Monise Petrucelli ◽  
Kamila Peronni ◽  
Pablo Sanches ◽  
Tatiana Komoto ◽  
Josie Matsuda ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Trichophyton Rubrum ◽  
Glyoxylate Cycle ◽  
Human Keratinocytes ◽  
Rna Seq ◽  
Fungal Host ◽  
Host Interaction ◽  
Genes Encoding ◽  
Hacat Keratinocyte

The dermatophyte Trichophyton rubrum is the major fungal pathogen of skin, hair, and nails that uses keratinized substrates as the primary nutrients during infection. Few strategies are available that permit a better understanding of the molecular mechanisms involved in the interaction of T. rubrum with the host because of the limitations of models mimicking this interaction. Dual RNA-seq is a powerful tool to unravel this complex interaction since it enables simultaneous evaluation of the transcriptome of two organisms. Using this technology in an in vitro model of co-culture, this study evaluated the transcriptional profile of genes involved in fungus-host interactions in 24 h. Our data demonstrated the induction of glyoxylate cycle genes, ERG6 and TERG_00916, which encodes a carboxylic acid transporter that may improve the assimilation of nutrients and fungal survival in the host. Furthermore, genes encoding keratinolytic proteases were also induced. In human keratinocytes (HaCat) cells, the SLC11A1, RNASE7, and CSF2 genes were induced and the products of these genes are known to have antimicrobial activity. In addition, the FLG and KRT1 genes involved in the epithelial barrier integrity were inhibited. This analysis showed the modulation of important genes involved in T. rubrum–host interaction, which could represent potential antifungal targets for the treatment of dermatophytoses.

scholarly journals Cyclophilin a as a Mediator of Tissue Injure and Nephrotoxicity

2012 ◽  
Vol 4 (2) ◽  
pp. 42-44
Author(s):  
Grace Moscoso-Solorzano ◽  
Gianna Mastroianni-Kirsztajn
Keyword(s):  
Molecular Mechanisms ◽  
Tissue Injury ◽  
Cyclophilin A ◽  
Common Mechanism ◽  
Ppiase Activity ◽  
Expression Of Genes ◽  
Inflammatory Stimuli ◽  
Genes Encoding ◽  
Inflammatory Processes

Cyclophilin A (CypA) belongs to the peptidyl-prolil isomerase (PPlase) family of proteins and it is also known as the cellular receptor for cyclosporine A (CsA). CsA binds to CypA and inhibits the PPIase activity, but the CypA-CsA complex also binds to calcineurin that promotes the expression of genes encoding cytokines and other proteins required for immune response. In addition, the polymorphism variation of CypA promoter seems to have an influence on the expression of CypA in in vitro studies. CypA was also implicated in inflammatory processes (such as, among others, those observed in rheumatoid arthritis, atherosclerotic disease, nephrotoxicity) and it can be secreted by cells in response to inflammatory stimuli. CypA can also have a role in the molecular mechanisms by which CsA induces nephroxicity but these remain poorly understood. Recent studies suggest that CsA inhibition of CypA PPlase activity is a possible mechanism of this drug toxicity. In addition, CypA overexpression could be protective against CsA nephrotoxicity. Finally, the putative common mechanism by which CypA could be involved in CsA nephrotoxicity and tissue injury is related to its proinflammatory effects in cells.

scholarly journals Developmental Genes and Malformations in the Hypothalamus

2020 ◽  
Vol 14 ◽  
Author(s):  
Carmen Diaz ◽  
Luis Puelles
Keyword(s):  
Transcription Factors ◽  
Energy Metabolism ◽  
Molecular Mechanisms ◽  
Review Article ◽  
Pituitary Development ◽  
Forebrain Development ◽  
Physiological Processes ◽  
Brain Malformations ◽  
Clinical Complexity ◽  
Genes Encoding

The hypothalamus is a heterogeneous rostral forebrain region that regulates physiological processes essential for survival, energy metabolism, and reproduction, mainly mediated by the pituitary gland. In the updated prosomeric model, the hypothalamus represents the rostralmost forebrain, composed of two segmental regions (terminal and peduncular hypothalamus), which extend respectively into the non-evaginated preoptic telencephalon and the evaginated pallio-subpallial telencephalon. Complex genetic cascades of transcription factors and signaling molecules rule their development. Alterations of some of these molecular mechanisms acting during forebrain development are associated with more or less severe hypothalamic and pituitary dysfunctions, which may be associated with brain malformations such as holoprosencephaly or septo-optic dysplasia. Studies on transgenic mice with mutated genes encoding critical transcription factors implicated in hypothalamic-pituitary development are contributing to understanding the high clinical complexity of these pathologies. In this review article, we will analyze first the complex molecular genoarchitecture of the hypothalamus resulting from the activity of previous morphogenetic signaling centers and secondly some malformations related to alterations in genes implicated in the development of the hypothalamus.

New Approaches for Mapping Epigenome Dynamics

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. SCI-21-SCI-21
Author(s):  
Steven Henikoff
Keyword(s):  
Transcription Factors ◽  
Rna Polymerase Ii ◽  
Conflicts Of Interest ◽  
Regulation Of Transcription ◽  
Base Pairs ◽  
Simple Method ◽  
Genome Wide ◽  
Resolution Mapping

Abstract The protein complexes that package our genomes must be mobilized for active processes to occur, including replication and transcription, but until recently we have only had a static, low resolution view of the "epigenome". Genomes are packaged into nucleosomes, octamers of four core histones wrapped by 147 base pairs of DNA. Nucleosomes present obstacles to transcription, which over genes is the RNA Polymerase II (RNAPII) complex, and one current challenge is to understand what happens to a nucleosome when RNAPII transcribes through the DNA that it occupies. We study this process by developing methods for following nucleosomes as they are evicted and replaced. Among the factors that we have implicated in the process is torsional stress, which we can now measure genome-wide. RNAPII movement can unwrap nucleosomes and thus destabilize them, causing them to be occasionally evicted and replaced. Interestingly, we find that destabilization of nucleosomes during transcription is enhanced by anthracycline compounds, widely used chemotherapeutic drugs that intercalate between DNA base pairs, thus suggesting a new mechanism for cell killing during chemotherapy. We are also interested in what happens to RNAPII during its encounter with a nucleosomes. In vitro, RNAPII cannot transcribe completely through a nucleosome, but rather stalls as it tries to unwrap the DNA from around the core. We have been studying this process in vivo, and have developed a simple method for precisely mapping RNAPII genome-wide. We have used this method to show exactly where RNAPII stalls as it unwraps a nucleosome in vivo, surprisingly in a different place in vivo from where it stalls in vitro. We also have discovered that a variant histone, H2A.Z, which is found in essentially all eukaryotes, helps to reduce the nucleosome barrier to transcription, and in this way may modulate transcription. Other protein components of the epigenome involved in dynamic processes are nucleosome remodelers, which use the energy of ATP to slide or even evict nucleosomes from DNA. Some remodelers help RNAPII get started and others help it overcome the nucleosome barrier to transcription, and by mapping them at base-pair resolution, we can gain insight into how they act. We have also applied our high-resolution mapping tools to transcription factors, which bind DNA at specific sites to regulate transcription and other processes. Our ability to achieve high spatial and temporal resolution mapping of the binding and action of nucleosomes, transcription factors, remodelers and RNAPII provides us with a detailed picture of epigenome dynamics. By using these tools we are beginning to understand how DNA sequence and conformation are recognized for regulation of transcription and other epigenomic processes. Disclosures No relevant conflicts of interest to declare.

scholarly journals Natural selection driven by DNA binding proteins shapes genome-wide motif statistics

2016 ◽  
Author(s):  
Long Qian ◽  
Edo Kussell
Keyword(s):  
Transcription Factors ◽  
Dna Binding ◽  
Binding Proteins ◽  
Dna Binding Proteins ◽  
Large Collection ◽  
Functional Sites ◽  
Genome Wide ◽  
A Genome ◽  
Global Selection

AbstractEctopic DNA binding by transcription factors and other DNA binding proteins can be detrimental to cellular functions and ultimately to organismal fitness. The frequency of protein-DNA binding at non-functional sites depends on the global composition of a genome with respect to all possible short motifs, or k-mer words. To determine whether weak yet ubiquitous protein-DNA interactions could exert significant evolutionary pressures on genomes, we correlate in vitro measurements of binding strengths on all 8-mer words from a large collection of transcription factors, in several different species, against their relative genomic frequencies. Our analysis reveals a clear signal of purifying selection to reduce the large number of weak binding sites genome-wide. This evolutionary process, which we call global selection, has a detectable hallmark in that similar words experience similar evolutionary pressure, a consequence of the biophysics of protein-DNA binding. By analyzing a large collection of genomes, we show that global selection exists in all domains of life, and operates through tiny selective steps, maintaining genomic binding landscapes over long evolutionary timescales.

scholarly journals Decoding molecular markers and transcriptional circuitry of naive and primed states of human pluripotency

2020 ◽  
Author(s):  
Arindam Ghosh ◽  
Anup Som
Keyword(s):  
Transcription Factors ◽  
Molecular Mechanisms ◽  
System Development ◽  
Enrichment Analysis ◽  
Pathway Enrichment Analysis ◽  
List Type ◽  
Metabolic Processes ◽  
Primed State

ABSTRACTPluripotent stem cells (PSCs) have been observed to occur in two distinct states — naive and primed. Both naive and primed state PSCs can give rise to tissues of all the three germ layers in vitro but differ in their potential to generate germline chimera in vivo. Understanding the molecular mechanisms that govern these two states of pluripotency in human can open up a plethora of opportunities for studying early embryonic development and in biomedical applications. In this work, we use weighted gene co-expression network (WGCN) approach to identify the key molecular makers and their interactions that define the two distinct pluripotency states. Signed-hybrid WGCN was reconstructed from transcriptomic data (RNA-seq) of naive and primed state pluripotent samples. Our analysis revealed two sets of genes that are involved in establishment and maintenance of naive (4791 genes) and primed (5066 genes) states. The naive state genes were found to be enriched for biological processes and pathways related to metabolic processes while primed state genes were associated with system development. Further, we identified the top 10% genes by intra-modular connectivity as hubs and the hub transcription factors for each group, thus providing a three-tier list of genes associated with naive and primed states of pluripotency in human.HIGHLIGHTSWeighted gene co-expression network analysis (WGCNA) identified 4791 and 5066 genes to be involved in naive and primed states of human pluripotency respectively.Functional and pathway enrichment analysis revealed the naive genes were mostly related to metabolic processes and primed genes to system development.The top 10% genes based on intra-modular connectivity from each group were defined as hubs.Identified 52 and 33 transcription factors among the naive and primed module hubs respectively.The transcription factors might play a switch on-off mechanism in induction of the two pluripotent states.

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