scholarly journals A review of epigenetic changes in asthma: methylation and acetylation

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Mojgan Sheikhpour ◽  
Mobina Maleki ◽  
Maryam Ebrahimi Vargoorani ◽  
Vahid Amiri
Keyword(s):  
Dna Methylation ◽  
Histone Modifications ◽  
Histone Methylation ◽  
Epigenetic Changes ◽  
External Effects ◽  
The Past ◽  
Immune Pathways ◽  
Shed Light ◽  
Histone Methylation And Acetylation

AbstractSeveral studies show that childhood and adulthood asthma and its symptoms can be modulated through epigenetic modifications. Epigenetic changes are inheritable modifications that can modify the gene expression without changing the DNA sequence. The most common epigenetic alternations consist of DNA methylation and histone modifications. How these changes lead to asthmatic phenotype or promote the asthma features, in particular by immune pathways regulation, is an understudied topic. Since external effects, like exposure to tobacco smoke, air pollution, and drugs, influence both asthma development and the epigenome, elucidating the role of epigenetic changes in asthma is of great importance. This review presents available evidence on the epigenetic process that drives asthma genes and pathways, with a particular focus on DNA methylation, histone methylation, and acetylation. We gathered and assessed studies conducted in this field over the past two decades. Our study examined asthma in different aspects and also shed light on the limitations and the important factors involved in the outcomes of the studies. To date, most of the studies in this area have been carried out on DNA methylation. Therefore, the need for diagnostic and therapeutic applications through this molecular process calls for more research on the histone modifications in this disease.

scholarly journals The Role of DNA Methylation and Histone Modification in Periodontal Disease: A Systematic Review

2020 ◽  
Vol 21 (17) ◽  
pp. 6217
Author(s):  
Ismael Khouly ◽  
Rosalie Salus Braun ◽  
Michelle Ordway ◽  
Bradley Eric Aouizerat ◽  
Iya Ghassib ◽  
...  
Keyword(s):  
Systematic Review ◽  
Dna Methylation ◽  
Periodontal Disease ◽  
Histone Modification ◽  
Histone Modifications ◽  
Disease Risk ◽  
Periodontal Diseases ◽  
Epigenetic Changes ◽  
Human Adults

Despite a number of reports in the literature on the role of epigenetic mechanisms in periodontal disease, a thorough assessment of the published studies is warranted to better comprehend the evidence on the relationship between epigenetic changes and periodontal disease and its treatment. Therefore, the aim of this systematic review is to identify and synthesize the evidence for an association between DNA methylation/histone modification and periodontal disease and its treatment in human adults. A systematic search was independently conducted to identify articles meeting the inclusion criteria. DNA methylation and histone modifications associated with periodontal diseases, gene expression, epigenetic changes after periodontal therapy, and the association between epigenetics and clinical parameters were evaluated. Sixteen studies were identified. All included studies examined DNA modifications in relation to periodontitis, and none of the studies examined histone modifications. Substantial variation regarding the reporting of sample sizes and patient characteristics, statistical analyses, and methodology, was found. There was some evidence, albeit inconsistent, for an association between DNA methylation and periodontal disease. IL6, IL6R, IFNG, PTGS2, SOCS1, and TNF were identified as candidate genes that have been assessed for DNA methylation in periodontitis. While several included studies found associations between methylation levels and periodontal disease risk, there is insufficient evidence to support or refute an association between DNA methylation and periodontal disease/therapy in human adults. Further research must be conducted to identify reproducible epigenetic markers and determine the extent to which DNA methylation can be applied as a clinical biomarker.

The Emerging Role of Epigenetic Methylation in Kidney Disease

2021 ◽  
Vol 28 ◽  
Author(s):  
Li Wen ◽  
Hong-liu Yang ◽  
Lin Lin ◽  
Liang Ma ◽  
Ping Fu
Keyword(s):  
Dna Methylation ◽  
Kidney Disease ◽  
Histone Methylation ◽  
Kidney Diseases ◽  
Therapeutic Approaches ◽  
Promoter Regions ◽  
Recent Advances ◽  
Epigenetic Methylation

: Kidney disease has complex and multifactorial pathophysiology and pathogenesis. Recent studies have revealed that epigenetic methylation changes, namely DNA methylation, histone methylation and non-histone methylation, are strongly implicated in various forms of kidney diseases. This review provides a perspective on the emerging role of epigenetic methylation in kidney disease, including the effects of DNA methylation in diverse promoter regions, regulation and implication of histone methylation, and recent advances and potential directions related to non-histone methylation. Monitoring or targeting epigenetic methylation has potential to contribute to development of therapeutic approaches for multiple kidney diseases.

scholarly journals The Role of Superstition in Twain’s The Adventures of Huckleberry Finn and Shakespeare’s Macbeth: A Comparative Study

2016 ◽  
Vol 6 (1) ◽  
pp. 37
Author(s):  
Jamal Subhi Ismail Nafi’
Keyword(s):  
Comparative Study ◽  
Social Factors ◽  
Religious Beliefs ◽  
Adventures Of Huckleberry Finn ◽  
The Past ◽  
The People ◽  
The Universe ◽  
Shed Light ◽  
Huckleberry Finn

<p>This article is an attempt to explore the inclusion and the use of superstitious elements in Mark Twain’s novel <em>The Adventures of Huckleberry Finn</em> (1884) and Shakespeare’s play <em>Macbeth</em> (1611). Superstition involves a deep belief in the magic and the occult, to almost to an extent of obsession, which is contrary to realism. Through the analytical and psychological approaches, this paper tries to shed light on Twain’s and Shakespeare’s use of supernaturalism in their respective stories, and the extent the main characters are influenced by it. A glance at both stories reveals that characters are highly affected by superstitions, more than they are influenced by their religious beliefs, or other social factors and values. The researcher also tries to explore the role played by superstition, represented by fate and the supernatural in determining the course of actions characters undertake in both dramas. The paper concluded that the people who lived in the past were superstitious to an extent of letting magic, omens; signs, etc. affect and determine their lives; actions and future decisions. They determine their destiny and make it very difficult for them to avoid it, alter it or think rationally and independently. And that, man’s actions are not isolated, but closely connected to the various forces operating in the universe.</p>

A haploid affair: core histone transitions during spermatogenesis

2003 ◽  
Vol 81 (3) ◽  
pp. 131-140 ◽  
Author(s):  
John D Lewis ◽  
D Wade Abbott ◽  
Juan Ausió
Keyword(s):  
Histone Modifications ◽  
Chromatin Structure ◽  
Critical Role ◽  
Diploid Cell ◽  
Histone Variants ◽  
Histone H4 ◽  
Dna Compaction ◽  
Dynamic Composition ◽  
Shed Light

The process of meiosis reduces a diploid cell to four haploid gametes and is accompanied by extensive recombination. Thus, the dynamics of chromatin during meiosis are significantly different than in mitotic cells. As spermatogenesis progresses, there is a widespread reorganization of the haploid genome followed by extensive DNA compaction. It has become increasingly clear that the dynamic composition of chromatin plays a critical role in the activities of enzymes and processes that act upon it. Therefore, an analysis of the role of histone variants and modifications in these processes may shed light upon the mechanisms involved and the control of chromatin structure in general. Histone variants such as histone H3.3, H2AX, and macroH2A appear to play key roles in the various stages of spermiogenesis, in addition to the specifically modulated acetylation of histone H4 (acH4), ubiquitination of histones H2A and H2B (uH2A, uH2B), and phosphorylation of histone H3 (H3p). This review will examine recent discoveries concerning the role of histone modifications and variants during meiosis and spermatogenesis.Key words: histone variants, histone modifications, chromatin structure, meiosis.

scholarly journals From Nursery to Nursing Home: Emerging Concepts in Clostridioides difficile Pathogenesis

2020 ◽  
Vol 88 (7) ◽  
Author(s):  
Alexander B. Smith ◽  
Joshua Soto Ocana ◽  
Joseph P. Zackular
Keyword(s):  
Pharmaceutical Drugs ◽  
Human Gastrointestinal Tract ◽  
Content Type ◽  
The Past ◽  
Clostridioides Difficile ◽  
Wide Range ◽  
Pediatric Populations ◽  
The Impact ◽  
Shed Light

ABSTRACT Clostridioides difficile is a Gram-positive, spore-forming, anaerobic bacterium that infects the human gastrointestinal tract, causing a wide range of disorders that vary in severity from mild diarrhea to toxic megacolon and/or death. Over the past decade, incidence, severity, and costs associated with C. difficile infection (CDI) have increased dramatically in both the pediatric and adult populations. The factors driving this rapidly evolving epidemiology remain largely unknown but are likely due in part to previously unappreciated host, microbiota, and environmental factors. In this review, we will cover the risks and challenges of CDI in adult and pediatric populations and examine asymptomatic colonization in infants. We will also discuss the emerging role of diet, pharmaceutical drugs, and pathogen-microbiota interactions in C. difficile pathogenesis, as well as the impact of host-microbiota interactions in the manifestation of C. difficile-associated disease. Finally, we highlight new areas of research and novel strategies that may shed light on this complex infection and provide insights into the future of microbiota-based therapeutics for CDI.

scholarly journals DNA methylation: dynamic and stable regulation of memory

2011 ◽  
Vol 2 (6) ◽  
pp. 459-467 ◽  
Author(s):  
Thomas Vaissière ◽  
Courtney A. Miller
Keyword(s):  
Dna Methylation ◽  
Transcriptional Regulation ◽  
Learning And Memory ◽  
Gene Transcription ◽  
Histone Modifications ◽  
Epigenetic Mechanisms ◽  
Epigenetic Changes ◽  
Central Process ◽  
Recent Advances ◽  
Epigenetic Events

AbstractEpigenetic mechanisms have emerged as a central process in learning and memory. Histone modifications and DNA methy­lation are epigenetic events that can mediate gene transcription. Interesting features of these epigenetic changes are their transient and long lasting potential. Recent advances in neuroscience suggest that DNA methylation is both dynamic and stable, mediating the formation and maintenance of memory. In this review, we will further illustrate the recent hypothesis that DNA methylation participates in the transcriptional regulation necessary for memory.

The Role of Histone Demethylases in the Transcription Regulation of HOX Genes in PML-RARa+ AML Patients

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 876-876
Author(s):  
Katerina Rejlova ◽  
Karolina Kramarzova ◽  
Meritxell Alberich-Jorda ◽  
Karel Fiser ◽  
Marketa Zaliova ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Histone Methylation ◽  
Hox Genes ◽  
Histone Demethylases ◽  
Atra Treatment ◽  
Hox Gene ◽  
Genes Expression ◽  
Methylation Mark

Abstract Homeobox genes (HOX) encode transcription factors that are frequently deregulated in leukemias. Our previous findings described that HOX gene expression differs among genetically characterized subtypes of pediatric AML with PML-RARa+ patients having the lowest overall HOX gene expression. We observed that HOX gene expression positively correlated with expression of histone 3 lysine 27 (H3K27) demethylases JMJD3 and UTX and negatively with DNA methyltransferase DNMT3b. Interestingly, it has been shown that JMJD3 is a direct target of PML-RARa protein (Martens, JH et al, 2010, Cancer Cell). These findings led us to postulate the hypothesis that reduced levels of HOX genes in PML-RARa+ AML can be caused by the suppressed expression of histone demethylases, such as JMJD3 and UTX, resulting in increased H3K27 methylation and transcription inhibition. We chose PML-RARa+ NB4 cell line to study the role of PML-RARa fusion gene in the regulation of HOX gene expression. To inhibit the effect of PML-RARa we used all-trans retinoic acid (ATRA; 1 uM, 10 uM) which was described to release the block caused by this fusion protein. Expression of particular HOX genes (e.g., HOXA1, HOXA3, HOXA5, HOXA7) together with that of JMJD3 and UTX assessed by qPCR was significantly elevated after ATRA treatment, while gene expression of DNMT3b was decreased. To test whether the reduction in HOX gene expression is directly related to the levels of JMJD3 and UTX, we cultured NB4 cells with a specific inhibitor of these histone demethylases, GSK-J4 (1 uM, 10 uM), in combination with ATRA. This co-treatment led to inhibition of JMJD3 and UTX proteins, followed by significant reduction of HOX genes expression (e.g., HOXA1, HOXA3, HOXA5, HOXA7). This result supports our hypothesis that HOX genes expression is directly related to JMJD3/UTX activity. To determine the effect of ATRA and GSK-J4 on histone marks we have isolated histones by acid extraction and detected the levels of histones by western blot in NB4 ATRA or GSK-J4/ATRA treated cells. We observed that the level of repressive histone methylation mark (trimethylated H3K27; H3K27me3) was decreased after ATRA treatment (activation of JMJD3/UTX) and increased after GSK-J4/ATRA co-treatment (inhibition of JMJD3/UTX). The opposite effect was observed in active histone methylation marks where di- and tri-methylated H3K4 (H3K4me2, H3K4me3) increased after ATRA treatment and decreased after GSK-J4/ATRA co-treatment. H3K9 dimethylated (another repressive histone methylation mark) levels did not change. Next, to investigate the histone code directly in particular HOX genes regions we performed chromatin immunoprecipitation (ChIP) assays. We studied the presence of H3K27me3 and H3K4me2 in 5´UTR genomic region of particular HOX genes (HOXA1, HOXA2, HOXA3, HOXA5, HOXA7) in cells treated with ATRA alone or in the combination with GSK-J4. Preliminary results showed reduction in repressive marks (H3K27me3) upon ATRA treatment, whereas addition of GSK-J4 prevented this decrease. Accordingly, we observed that ATRA/GSK-J4 co-treatment reduced active histone mark H3K4me2. To evaluate the role of DNA methylation in observed expression changes after ATRA treatment we performed bisulfite sequencing of particular promoter sites of HOX genes (e.g., HOXA7, HOXA5). Although we detected decreased DNMT3b gene expression after ATRA treatment there was no change in DNA methylation of CpGs in studied regions. Our results demonstrate that changes in chromatin activity correspond with changes in HOX gene expression. Moreover, ChIP data show direct binding of the modified histones and HOX 5´UTR sites. Our data implicate histone demethylases in regulation of HOX gene expression in PML-RARa+ leukemic blasts. DNA methylation in these particular HOX genes is not involved in the regulation. Elucidating the mechanism of regulation of HOX genes expression can help to understand their role in the leukemogenic process. Supported by GACR P304/12/2214 and GAUK 568213. Disclosures No relevant conflicts of interest to declare.

scholarly journals The Past and its Possibilities in Nahḍa Scholarship

2021 ◽  
Vol 6 (3-4) ◽  
pp. 265-287
Author(s):  
Feras Krimsti ◽  
John-Paul Ghobrial
Keyword(s):  
Twentieth Century ◽  
Special Issue ◽  
Record Keeping ◽  
The Past ◽  
History Of ◽  
Historical Heritage ◽  
The Many ◽  
Historical Reflection ◽  
Shed Light

Abstract This introduction to the special issue “The Past and its Possibilities in Nahḍa Scholarship” reflects on the role of the past in nineteenth- and early twentieth-century nahḍa discourse. It argues that historical reflection played a pivotal role in a number of scholarly disciplines besides the discipline of history, notably philosophy and logic, grammar and lexicography, linguistics, philology, and adab. Nahḍawīs reflected on continuities with the past, the genealogies of their present, and the role of history in determining their future. The introduction of print gave new impulses to the engagement with the historical heritage. We argue for a history of the nahḍa as a de-centred history of possibilities that recovers a wider circle of scholars and intellectuals and their multiple and overlapping local and global audiences. Such a history can also shed light on the many ways in which historical reflection, record-keeping practices, and confessional, sectarian, or communalist agendas are entwined.

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