Displaying publications 1 - 20 of 42 in total

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  1. Fulltext Molecular mechanisms underlying the clinical efficacy of panobinostat involve Stochasticity of epigenetic signaling, sensitization to anticancer drugs, and induction of cellular cell death related to cellular stresses
    El Omari N, Bakrim S, Khalid A, Abdalla AN, Almalki WH, Lee LH, et al.
    Biomed Pharmacother, 2023 Aug;164:114886.
    PMID: 37224752 DOI: 10.1016/j.biopha.2023.114886
    Panobinostat, also known as Farydak®, LBH589, PNB, or panobinostat lactate, is a hydroxamic acid that has been approved by the Food and Drug Administration (FDA) for its anti-cancer properties. This orally bioavailable drug is classified as a non-selective histone deacetylase inhibitor (pan-HDACi) that inhibits class I, II, and IV HDACs at nanomolar levels due to its significant histone modifications and epigenetic mechanisms. A mismatch between histone acetyltransferases (HATs) and HDACs can negatively affect the regulation of the genes concerned, which in turn can contribute to tumorigenesis. Indeed, panobinostat inhibits HDACs, potentially leading to acetylated histone accumulation, re-establishing normal gene expression in cancer cells, and helping to drive multiple signaling pathways. These pathways include induction of histone acetylation and cytotoxicity for the majority of tested cancer cell lines, increased levels of p21 cell cycle proteins, enhanced amounts of pro-apoptotic factors (such as caspase-3/7 activity and cleaved poly (ADP-ribose) polymerase (PARP)) associated with decreased levels of anti-apoptotic factors [B-cell lymphoma 2 (Bcl-2) and B-cell lymphoma-extra-large (Bcl-XL)], as well as regulation of immune response [upregulated programmed death-ligand 1 (PD-L1) and interferon gamma receptor 1 (IFN-γR1) expression] and other events. The therapeutic outcome of panobinostat is therefore mediated by sub-pathways involving proteasome and/or aggresome degradation, endoplasmic reticulum, cell cycle arrest, promotion of extrinsic and intrinsic processes of apoptosis, tumor microenvironment remodeling, and angiogenesis inhibition. In this investigation, we aimed to pinpoint the precise molecular mechanism underlying panobinostat's HDAC inhibitory effect. A more thorough understanding of these mechanisms will greatly advance our knowledge of cancer cell aberrations and, as a result, provide an opportunity for the discovery of significant new therapeutic perspectives through cancer therapeutics.
    Matched MeSH terms: Histones/metabolism
  2. Fulltext Expression, purification, crystallization and preliminary X-ray crystallographic analysis of the histone-like HU protein from Spiroplasma melliferum KC3
    Boyko K, Gorbacheva M, Rakitina T, Korzhenevskiy D, Vanyushkina A, Kamashev D, et al.
    Acta Crystallogr F Struct Biol Commun, 2015 Jan 01;71(Pt 1):24-7.
    PMID: 25615963 DOI: 10.1107/S2053230X14025333
    HU proteins belong to the nucleoid-associated proteins (NAPs) that are involved in vital processes such as DNA compaction and reparation, gene transcription etc. No data are available on the structures of HU proteins from mycoplasmas. To this end, the HU protein from the parasitic mycoplasma Spiroplasma melliferum KC3 was cloned, overexpressed in Escherichia coli and purified to homogeneity. Prismatic crystals of the protein were obtained by the vapour-diffusion technique at 4°C. The crystals diffracted to 1.36 Å resolution (the best resolution ever obtained for a HU protein). The diffraction data were indexed in space group C2 and the structure of the protein was solved by the molecular-replacement method with one monomer per asymmetric unit.
    Matched MeSH terms: Histones/biosynthesis; Histones/isolation & purification; Histones/chemistry
  3. Fulltext The Value of H3K27me3 Immunohistochemistry in Differentiating Malignant Peripheral Nerve Sheath Tumour with Its Histologic Mimickers
    Mustapar N, Zawawi MSF, Tuan Sharif SE
    Asian Pac J Cancer Prev, 2020 Mar 01;21(3):699-705.
    PMID: 32212796 DOI: 10.31557/APJCP.2020.21.3.699
    BACKGROUND: Diagnosis of malignant peripheral nerve sheath tumor (MPNST) is rather challenging due to its divergent morphologic heterogeneity and lack of specific ancillary test. The emergence of H3K27 trimethylation (H3K27me3) as a new immunohistochemistry (IHC) marker for MPNST have recently available to assist pathologists in differentiating MPNST from other histologic mimics. We aim to study the expression pattern of H3K27me3 in MPNST and its histologic mimickers and their association with the clinicopathological data.

    METHODOLOGY: A total of 59 benign and malignant spindle cell tumours (18 MPNST and 41 of its histologic mimickers which included 10 schwannoma, 13 neurofibroma, 4 synovial sarcoma, 3 fibrosarcoma, 2 gastrointestinal stromal tumour (GIST), 4 leiomyosarcoma, 1 spindle cell liposarcoma, 1 solitary fibrous tumour, 2 low grade fibromyxoid sarcoma and 1 unclassified spindle cell sarcoma), diagnosed from January 1998 to April 2018 in Hospital Universiti Sains Malaysia (HUSM) were tested for H3K27me3 by IHC. The MPNST histological grade was assessed based on the French Fe'de' ration Nationale des Centres de LutteContre le Cancer (FNCLCC) for 3 tiers system (low grade, intermediate grade and high grade). The clinicopathological data were retrieved from the patients' record.

    RESULTS: A total of 61.1% (11/18 MPNST) showed loss of H3K27me3 expression which is statistically significant as compared to its histologic mimics (p<0.001). Similar findings (p=0.026) were also observed in high grade MPNST (81.8%), intermediate grade MPNST (100%) and 0% in low grade MPNST.

    CONCLUSION: H3K27me3, combined with other panel of markers, is useful in MPNST diagnosis to differentiate it from the histological mimickers.

    Matched MeSH terms: Histones/metabolism*
  4. Dual inhibitors of HDAC and other epigenetic regulators: A novel strategy for cancer treatment
    Shirbhate E, Singh V, Jahoriya V, Mishra A, Veerasamy R, Tiwari AK, et al.
    Eur J Med Chem, 2024 Jan 05;263:115938.
    PMID: 37989059 DOI: 10.1016/j.ejmech.2023.115938
    A significant advancement in the field of epigenetic drug discovery has been evidenced in recent years. Epigenetic alterations are hereditary, nevertheless reversible variations to DNA or histone adaptations that regulate gene function individualistically of the fundamental sequence. The design and synthesis of various drugs targeting epigenetic regulators open a new door for epigenetic-targeted therapies to parade worthwhile therapeutic potential for haematological and solid malignancies. Several ongoing clinical trials on dual targeting strategy are being conducted comprising HDAC inhibitory component and an epigenetic regulating agent. In this perspective, the review discusses the pharmacological aspects of HDAC and other epigenetic regulating factors as dual inhibitors as an emerging alternative approach for combination therapies.
    Matched MeSH terms: Histones/genetics
  5. Fulltext Psychiatric genome-wide association study analyses implicate neuronal, immune and histone pathways
    Network and Pathway Analysis Subgroup of Psychiatric Genomics Consortium
    Nat Neurosci, 2015 Feb;18(2):199-209.
    PMID: 25599223 DOI: 10.1038/nn.3922
    Genome-wide association studies (GWAS) of psychiatric disorders have identified multiple genetic associations with such disorders, but better methods are needed to derive the underlying biological mechanisms that these signals indicate. We sought to identify biological pathways in GWAS data from over 60,000 participants from the Psychiatric Genomics Consortium. We developed an analysis framework to rank pathways that requires only summary statistics. We combined this score across disorders to find common pathways across three adult psychiatric disorders: schizophrenia, major depression and bipolar disorder. Histone methylation processes showed the strongest association, and we also found statistically significant evidence for associations with multiple immune and neuronal signaling pathways and with the postsynaptic density. Our study indicates that risk variants for psychiatric disorders aggregate in particular biological pathways and that these pathways are frequently shared between disorders. Our results confirm known mechanisms and suggest several novel insights into the etiology of psychiatric disorders.
    Matched MeSH terms: Histones/genetics; Histones/metabolism
  6. Silencing of transgene expression in mammalian cells by DNA methylation and histone modifications in gene therapy perspective
    Alhaji SY, Ngai SC, Abdullah S
    Biotechnol Genet Eng Rev, 2019 Apr;35(1):1-25.
    PMID: 30514178 DOI: 10.1080/02648725.2018.1551594
    DNA methylation and histone modifications are vital in maintaining genomic stability and modulating cellular functions in mammalian cells. These two epigenetic modifications are the most common gene regulatory systems known to spatially control gene expression. Transgene silencing by these two mechanisms is a major challenge to achieving effective gene therapy for many genetic conditions. The implications of transgene silencing caused by epigenetic modifications have been extensively studied and reported in numerous gene delivery studies. This review highlights instances of transgene silencing by DNA methylation and histone modification with specific focus on the role of these two epigenetic effects on the repression of transgene expression in mammalian cells from integrative and non-integrative based gene delivery systems in the context of gene therapy. It also discusses the prospects of achieving an effective and sustained transgene expression for future gene therapy applications.
    Matched MeSH terms: Histones
  7. Fulltext The Influence of Traffic-Related Air Pollution (TRAP) in Primary Schools and Residential Proximity to Traffic Sources on Histone H3 Level in Selected Malaysian Children
    Suhaimi NF, Jalaludin J, Abu Bakar S
    Int J Environ Res Public Health, 2021 07 28;18(15).
    PMID: 34360284 DOI: 10.3390/ijerph18157995
    This study aimed to investigate the association between traffic-related air pollution (TRAP) exposure and histone H3 modification among school children in high-traffic (HT) and low-traffic (LT) areas in Malaysia. Respondents' background information and personal exposure to traffic sources were obtained from questionnaires distributed to randomly selected school children. Real-time monitoring instruments were used for 6-h measurements of PM10, PM2.5, PM1, NO2, SO2, O3, CO, and total volatile organic compounds (TVOC). Meanwhile, 24-h measurements of PM2.5-bound black carbon (BC) were performed using air sampling pumps. The salivary histone H3 level was captured using an enzyme-linked immunosorbent assay (ELISA). HT schools had significantly higher PM10, PM2.5, PM1, BC, NO2, SO2, O3, CO, and TVOC than LT schools, all at p < 0.001. Children in the HT area were more likely to get higher histone H3 levels (z = -5.13). There were positive weak correlations between histone H3 level and concentrations of NO2 (r = 0.37), CO (r = 0.36), PM1 (r = 0.35), PM2.5 (r = 0.34), SO2 (r = 0.34), PM10 (r = 0.33), O3 (r = 0.33), TVOC (r = 0.25), and BC (r = 0.19). Overall, this study proposes the possible role of histone H3 modification in interpreting the effects of TRAP exposure via non-genotoxic mechanisms.
    Matched MeSH terms: Histones
  8. Fulltext Regions of very low H3K27me3 partition the Drosophila genome into topological domains
    El-Sharnouby S, Fischer B, Magbanua JP, Umans B, Flower R, Choo SW, et al.
    PLoS One, 2017;12(3):e0172725.
    PMID: 28282436 DOI: 10.1371/journal.pone.0172725
    It is now well established that eukaryote genomes have a common architectural organization into topologically associated domains (TADs) and evidence is accumulating that this organization plays an important role in gene regulation. However, the mechanisms that partition the genome into TADs and the nature of domain boundaries are still poorly understood. We have investigated boundary regions in the Drosophila genome and find that they can be identified as domains of very low H3K27me3. The genome-wide H3K27me3 profile partitions into two states; very low H3K27me3 identifies Depleted (D) domains that contain housekeeping genes and their regulators such as the histone acetyltransferase-containing NSL complex, whereas domains containing moderate-to-high levels of H3K27me3 (Enriched or E domains) are associated with regulated genes, irrespective of whether they are active or inactive. The D domains correlate with the boundaries of TADs and are enriched in a subset of architectural proteins, particularly Chromator, BEAF-32, and Z4/Putzig. However, rather than being clustered at the borders of these domains, these proteins bind throughout the H3K27me3-depleted regions and are much more strongly associated with the transcription start sites of housekeeping genes than with the H3K27me3 domain boundaries. While we have not demonstrated causality, we suggest that the D domain chromatin state, characterised by very low or absent H3K27me3 and established by housekeeping gene regulators, acts to separate topological domains thereby setting up the domain architecture of the genome.
    Matched MeSH terms: Histones/genetics; Histones/metabolism*; Histones/chemistry
  9. Fulltext Ageing, Drosophila melanogaster and Epigenetics
    Halim MA, Tan FHP, Azlan A, Rasyid II, Rosli N, Shamsuddin S, et al.
    Malays J Med Sci, 2020 May;27(3):7-19.
    PMID: 32684802 MyJurnal DOI: 10.21315/mjms2020.27.3.2
    Ageing is a phenomenon where the accumulation of all the stresses that alter the functions of living organisms, halter them from maintaining their physiological balance and eventually lead to death. The emergence of epigenetic tremendously contributed to the knowledge of ageing. Epigenetic changes in cells or tissues like deoxyribonucleic acid (DNA) methylation, modification of histone proteins, transcriptional modification and also the involvement of non-coding DNA has been documented to be associated with ageing. In order to study ageing, scientists have taken advantage of several potential organisms to aid them in their study. Drosophila melanogaster has been an essential model in establishing current understanding of the mechanism of ageing as they possess several advantages over other competitors like having homologues to more than 75% of human disease genes, having 50% of Drosophila genes are homologues to human genes and most importantly they are genetically amenable. Here, we would like to summarise the extant knowledge about ageing and epigenetic process and the role of Drosophila as an ideal model to study epigenetics in association with ageing process.
    Matched MeSH terms: Histones
  10. Enhanced DNA double-strand break repair of microbeam targeted A549 lung carcinoma cells by adjacent WI38 normal lung fibroblast cells via bi-directional signaling
    Kobayashi A, Tengku Ahmad TAF, Autsavapromporn N, Oikawa M, Homma-Takeda S, Furusawa Y, et al.
    Mutat Res, 2017 10;803-805:1-8.
    PMID: 28689138 DOI: 10.1016/j.mrfmmm.2017.06.006
    Understanding the mechanisms underlying the radiation-induced bystander effect (RIBE) and bi-directional signaling between irradiated carcinoma cells and their surrounding non-irradiated normal cells is relevant to cancer radiotherapy. The present study investigated propagation of RIBE signals between human lung carcinoma A549 cells and normal lung fibroblast WI38 cells in bystander cells, either directly or indirectly contacting irradiated A549 cells. We prepared A549-GFP/WI38 co-cultures and A549-GFP/A549 co-cultures, in which A549-GFP cells stably expressing H2BGFP were co-cultured with either A549 cells or WI38 cells, respectively. Using the SPICE-NIRS microbeam, only the A549-GFP cells were irradiated with 500 protons per cell. The level of γ-H2AX, a marker for DNA double-strand breaks (DSB), was subsequently measured for up to 24h post-irradiation in three categories of cells: (1) "targeted"/irradiated A549-GFP cells; (2) "neighboring"/non-irradiated cells directly contacting the "targeted" cells; and (3) "distant"/non-irradiated cells, which were not in direct contact with the "targeted" cells. We found that DSB repair in targeted A549-GFP cells was enhanced by co-cultured WI38 cells. The bystander response in A549-GFP/A549 cell co-cultures, as marked by γ-H2AX levels at 8h post-irradiation, showed a decrease to non-irradiated control level when approaching 24h, while the neighboring/distant bystander WI38 cells in A549-GFP/WI38 co-cultures was maintained at a similar level until 24h post-irradiation. Surprisingly, distant A549-GFP cells in A549-GFP/WI38 co-cultures showed time dependency similar to bystander WI38 cells, but not to distant cells in A549-GFP/A549 co-cultures. These observations indicate that γ-H2AX was induced in WI38 cells as a result of RIBE. WI38 cells were not only involved in rescue of targeted A549, but also in the modification of RIBE against distant A549-GFP cells. The present results demonstrate that radiation-induced bi-directional signaling had extended a profound influence on cellular sensitivity to radiation as well as the sensitivity to RIBE.
    Matched MeSH terms: Histones/metabolism
  11. Histone Deacetylase Inhibitors for the Treatment of Colorectal Cancer: Recent Progress and Future Prospects
    Singh A, Patel P, Patel VK, Jain DK, Veerasamy R, Sharma PC, et al.
    Curr Cancer Drug Targets, 2017;17(5):456-466.
    PMID: 28067178 DOI: 10.2174/1568009617666170109150134
    BACKGROUND: Colorectal cancer is a devastating disease with a dismal prognosis which is heavily hampered by delayed diagnosis. Surgical resection, radiation therapy and chemotherapy are the curative options. Due to few therapeutic treatments available i.e., mono and combination therapy and development of resistance towards drug response, novel and efficacious therapy are urgently needed.

    OBJECTIVE: In this study, we have studied the potential of histone deacetylase inhibitors in colorectal cancer.

    RESULTS: Histone deacetylase inhibitors (HDACIs) are an emerging class of therapeutic agents having potential anticancer activity with minimal toxicity for different types of malignancies in preclinical studies. HDACIs have proven less effective in monotherapy thus the combination of HDACIs with other anticancer agents are being assessed for the treatment of colorectal cancer.

    CONCLUSION: The molecular mechanism emphasizing the anticancer effect of HDACIs in colorectal cancer was illustrated and a recapitulation was carried out on the recent advances in the rationale behind combination therapies currently underway in clinical evaluations.

    Matched MeSH terms: Histones/metabolism
  12. Fulltext Molecular mechanistic pathways underlying the anticancer therapeutic efficiency of romidepsin
    El Omari N, Lee LH, Bakrim S, Makeen HA, Alhazmi HA, Mohan S, et al.
    Biomed Pharmacother, 2023 Aug;164:114774.
    PMID: 37224749 DOI: 10.1016/j.biopha.2023.114774
    Romidepsin, also known as NSC630176, FR901228, FK-228, FR-901228, depsipeptide, or Istodax®, is a natural molecule produced by the Chromobacterium violaceum bacterium that has been approved for its anti-cancer effect. This compound is a selective histone deacetylase (HDAC) inhibitor, which modifies histones and epigenetic pathways. An imbalance between HDAC and histone acetyltransferase can lead to the down-regulation of regulatory genes, resulting in tumorigenesis. Inhibition of HDACs by romidepsin indirectly contributes to the anticancer therapeutic effect by causing the accumulation of acetylated histones, restoring normal gene expression in cancer cells, and promoting alternative pathways, including the immune response, p53/p21 signaling cascades, cleaved caspases, poly (ADP-ribose) polymerase (PARP), and other events. Secondary pathways mediate the therapeutic action of romidepsin by disrupting the endoplasmic reticulum and proteasome and/or aggresome, arresting the cell cycle, inducing intrinsic and extrinsic apoptosis, inhibiting angiogenesis, and modifying the tumor microenvironment. This review aimed to highlight the specific molecular mechanisms responsible for HDAC inhibition by romidepsin. A more detailed understanding of these mechanisms can significantly improve the understanding of cancer cell disorders and pave the way for new therapeutic approaches using targeted therapy.
    Matched MeSH terms: Histones/metabolism
  13. Fulltext Anticancer clinical efficiency and stochastic mechanisms of belinostat
    El Omari N, Bakrim S, Khalid A, Albratty M, Abdalla AN, Lee LH, et al.
    Biomed Pharmacother, 2023 Sep;165:115212.
    PMID: 37541175 DOI: 10.1016/j.biopha.2023.115212
    Cancer progression is strongly affected by epigenetic events in addition to genetic modifications. One of the key elements in the epigenetic control of gene expression is histone modification through acetylation, which is regulated by the synergy between histone acetyltransferases (HATs) and histone deacetylases (HDACs). HDACs are thought to offer considerable potential for the development of anticancer medications, particularly when used in conjunction with other anticancer medications and/or radiotherapy. Belinostat (Beleodaq, PXD101) is a pan-HDAC unsaturated hydroxamate inhibitor with a sulfonamide group that has been approved by the U.S. Food and Drug Administration (FDA) for the treatment of refractory or relapsed peripheral T-cell lymphoma (PTCL) and solid malignancies or and other hematological tissues. This drug modifies histones and epigenetic pathways. Because HDAC and HAT imbalance can lead to downregulation of regulatory genes, resulting in tumorigenesis. Inhibition of HDACs by belinostat indirectly promotes anti-cancer therapeutic effect by provoking acetylated histone accumulation, re-establishing normal gene expressions in cancer cells and stimulating other routes such as the immune response, p27 signaling cascades, caspase 3 activation, nuclear protein poly (ADP-ribose) polymerase-1 (PARP-1) degradation, cyclin A (G2/M phase), cyclin E1 (G1/S phase) and other events. In addition, belinostat has already been discovered to increase p21WAF1 in a number of cell lines (melanoma, prostate, breast, lung, colon, and ovary). This cyclin-dependent kinase inhibitor actually has a role in processes that cause cell cycle arrest and apoptosis. Belinostat's clinical effectiveness, comprising Phase I and II studies within the areas of solid and hematological cancers, has been evidenced through several investigative trials that have supported its potential to be a valuable anti-cancer drug. The purpose of this research was to provide insight on the specific molecular processes through which belinostat inhibits HDAC. The ability to investigate new therapeutic options employing targeted therapy and acquire a deeper understanding of cancer cell abnormalities may result from a better understanding of these particular routes.
    Matched MeSH terms: Histones/metabolism
  14. Fulltext Neutrophil activation, acute lung injury and disease severity in Plasmodium knowlesi malaria
    Tan AF, Sakam SSB, Piera K, Rajahram GS, William T, Barber BE, et al.
    PLoS Negl Trop Dis, 2024 Aug;18(8):e0012424.
    PMID: 39150978 DOI: 10.1371/journal.pntd.0012424
    The risk of severe malaria from the zoonotic parasite Plasmodium knowlesi approximates that from P. falciparum. In severe falciparum malaria, neutrophil activation contributes to inflammatory pathogenesis, including acute lung injury (ALI). The role of neutrophil activation in the pathogenesis of severe knowlesi malaria has not been examined. We evaluated 213 patients with P. knowlesi mono-infection (138 non-severe, 75 severe) and 49 Plasmodium-negative controls from Malaysia. Markers of neutrophil activation (soluble neutrophil elastase [NE], citrullinated histone [CitH3] and circulating neutrophil extracellular traps [NETs]) were quantified in peripheral blood by microscopy and immunoassays. Findings were correlated with malaria severity, ALI clinical criteria, biomarkers of parasite biomass, haemolysis, and endothelial activation. Neutrophil activation increased with disease severity, with median levels higher in severe than non-severe malaria and controls for NE (380[IQR:210-930]ng/mL, 236[139-448]ng/mL, 218[134-307]ng/mL, respectively) and CitH3 (8.72[IQR:3.0-23.1]ng/mL, 4.29[1.46-9.49]ng/mL, 1.53[0.6-2.59]ng/mL, respectively)[all p<0.01]. NETs were higher in severe malaria compared to controls (126/μL[IQR:49-323] vs 51[20-75]/μL, p<0.001). In non-severe malaria, neutrophil activation fell significantly upon discharge from hospital (p<0.03). In severe disease, NETs, NE, and CitH3 were correlated with parasitaemia, cell-free haemoglobin and angiopoietin-2 (all Pearson's r>0.24, p<0.05). Plasma NE and angiopoietin-2 were higher in knowlesi patients with ALI than those without (p<0.008); neutrophilia was associated with an increased risk of ALI (aOR 3.27, p<0.01). In conclusion, neutrophil activation is increased in ALI and in proportion to disease severity in knowlesi malaria, is associated with endothelial activation, and may contribute to disease pathogenesis. Trials of adjunctive therapies to regulate neutrophil activation are warranted in severe knowlesi malaria.
    Matched MeSH terms: Histones/blood
  15. Fulltext Epigenetic modification does not determine the time of POU5F1 transcription activation in cloned bovine embryos
    Jafari S, Hosseini SM, Hajian M, Forouzanfar M, Jafarpour F, Abedi P, et al.
    J Assist Reprod Genet, 2011 Nov;28(11):1119-27.
    PMID: 22020531 DOI: 10.1007/s10815-011-9638-1
    To investigate the effect of epigenetic modification on pattern, time and capacity of transcription activation of POU5F1, the key marker of pluripotency, in cloned bovine embryos.
    Matched MeSH terms: Histones/genetics; Histones/metabolism
  16. Fulltext Histone deacetylase inhibitors as potential treatment for spinal muscular atrophy
    Mohseni J, Zabidi-Hussin ZA, Sasongko TH
    Genet Mol Biol, 2013 Sep;36(3):299-307.
    PMID: 24130434 DOI: 10.1590/S1415-47572013000300001
    Histone acetylation plays an important role in regulation of transcription in eukaryotic cells by promoting a more relaxed chromatin structure necessary for transcriptional activation. Histone deacetylases (HDACs) remove acetyl groups and suppress gene expression. HDAC inhibitors (HDACIs) are a group of small molecules that promote gene transcription by chromatin remodeling and have been extensively studied as potential drugs for treating of spinal muscular atrophy. Various drugs in this class have been studied with regard to their efficacy in increasing the expression of survival of motor neuron (SMN) protein. In this review, we discuss the current literature on this topic and summarize the findings of the main studies in this field.
    Matched MeSH terms: Histones
  17. Histone mRNA is subject to 3´ uridylation and re-adenylation in Aspergillus nidulans
    Mossanen-Parsi A, Parisi D, Browne-Marke N, Bharudin I, Connell SR, Mayans O, et al.
    Mol Microbiol, 2020 Oct 12.
    PMID: 33047379 DOI: 10.1111/mmi.14613
    The role of post-transcriptional RNA modification is of growing interest. One example is the addition of non-templated uridine residues to the 3´ end of transcripts. In mammalian systems uridylation is integral to cell cycle control of histone mRNA levels. This regulatory mechanism is dependent on the nonsense mediated decay (NMD) component, Upf1, which promotes histone mRNA uridylation and degradation in response to the arrest of DNA synthesis. We have identified a similar system in Aspergillus nidulans, where Upf1 is required for the regulation of histone mRNA levels. However, other NMD components are also implicated, distinguishing it from the mammalian system. As in human cells, 3´ uridylation of histone mRNA is induced upon replication arrest. Disruption of this 3´ tagging has a significant but limited effect on histone transcript regulation, consistent with multiple mechanisms acting to regulate mRNA levels. Interestingly, 3´ end degraded transcripts are also subject to re-adenylation. Both mRNA pyrimidine tagging and re-adenylation are dependent on the same terminal-nucleotidyltransferases, CutA and CutB, and we show this is consistent with the in vitro activities of both enzymes. Based on these data we argue that mRNA 3´ tagging has diverse and distinct roles associated with transcript degradation, functionality and regulation.
    Matched MeSH terms: Histones
  18. Fulltext EHMT1 protein binds to nuclear factor-κB p50 and represses gene expression
    Ea CK, Hao S, Yeo KS, Baltimore D
    J Biol Chem, 2012 Sep 7;287(37):31207-17.
    PMID: 22801426 DOI: 10.1074/jbc.M112.365601
    Transcriptional homeostasis relies on the balance between positive and negative regulation of gene transcription. Methylation of histone H3 lysine 9 (H3K9) is commonly correlated with gene repression. Here, we report that a euchromatic H3K9 methyltransferase, EHMT1, functions as a negative regulator in both the NF-κB- and type I interferon-mediated gene induction pathways. EHMT1 catalyzes H3K9 methylation at promoters of NF-κB target genes. Moreover, EHMT1 interacts with p50, and, surprisingly, p50 appears to repress the expression of type I interferon genes and genes activated by type I interferons by recruiting EHMT1 to catalyze H3K9 methylation at their promoter regions. Silencing the expression of EHMT1 by RNA interference enhances expression of a subset NF-κB-regulated genes, augments interferon production, and augments antiviral immunity.
    Matched MeSH terms: Histones/genetics; Histones/immunology; Histones/metabolism
  19. Sirtuins and Their Implications in Neurodegenerative Diseases from a Drug Discovery Perspective
    Yeong KY, Berdigaliyev N, Chang Y
    ACS Chem Neurosci, 2020 12 16;11(24):4073-4091.
    PMID: 33280374 DOI: 10.1021/acschemneuro.0c00696
    Sirtuins are class III histone deacetylase (HDAC) enzymes that target both histone and non-histone substrates. They are linked to different brain functions and the regulation of different isoforms of these enzymes is touted to be an emerging therapy for the treatment of neurodegenerative diseases (NDs), including Parkinson's disease (PD), Alzheimer's disease (AD), and amyotrophic lateral sclerosis (ALS). The level of sirtuins affects brain health as many sirtuin-regulated pathways are responsible for the progression of NDs. Certain sirtuins are also implicated in aging, which is a risk factor for many NDs. In addition to SIRT1-3, it has been suggested that the less studied sirtuins (SIRT4-7) also play critical roles in brain health. This review delineates the role of each sirtuin isoform in NDs from a disease centric perspective and provides an up-to-date overview of sirtuin modulators and their potential use as therapeutics in these diseases. Furthermore, the future perspectives for sirtuin modulator development and their therapeutic application in neurodegeneration are outlined in detail, hence providing a research direction for future studies.
    Matched MeSH terms: Histones
  20. First Report of Anthracnose Caused by Colletotrichum gloeosporioides on Soybean (Glycine max) in Malaysia
    Mahmodi F, Kadir JB, Wong MY, Nasehi A, Puteh A, Soleimani N
    Plant Dis, 2013 Jun;97(6):841.
    PMID: 30722625 DOI: 10.1094/PDIS-10-12-0944-PDN
    Soybean (Glycine max L.) is one of the most economically important crops in the world, and anthracnose is known to infect soybean in most countries. Colletotrichum truncatum is the common pathogen causing anthracnose of soybean. However, at least five species of Colletotrichum have been reported on soybean worldwide (2). In July 2010, anthracnose symptoms were observed on soybean in the experimental fields of the agriculture station in Ladang Dua, University Putra Malaysia located in Selangor state of Malaysia. Symptoms were initially observed on a few plants randomly within one field, but after 4 weeks, the disease was found in two additional fields scattered across an area of 1 km2. Pinkish-brown lesions were observed on the pods, and the formation of dark lesions on the leaves and stems was sometimes followed by stem girdling, dieback, and distorted growth. At later stages, numerous epidermal acervuli developed in the lesions, and mucilaginous conidial masses appeared during periods of high relative humidity. Conidia produced in acervuli were straight, cylindric, hyaline, and aseptate, with both ends rounded. Conidia measured (mean ± SD) 14.2 ± 0.6 × 3.6 ± 0.7 μm, and the L/W ratio was 3.95 μm. Six isolates of the fungus were obtained and identified as C. gloeosporioides on the basis of morphological characterization (3). The isolates were deposited in the University Putra of Malaysia Culture Collection (UPMCC). PDA cultures were white at first and subsequently became grayish to pink to reddish-brown. Amplification and sequence analysis of coding and none-coding regions of the ITS-rDNA (GenBank JX669450), actin (JX827430), β-tubulin (JX827454), histone (JX827448), chitin synthase (JX827436), and glyceraldehyde-3-phosphate dehydrogenase (JX827442) obtained from the representative isolate, CGM50, aligned with deposited sequences from GenBank and revealed 99 to 100% sequence identity with C. gloeosporioides strains (JX258757, JX009790, GQ849434, HM575301, JQ005413, and JX00948 from GenBank). One representative isolate, CGM50, was used for pathogenicity testing. Four non-infected detached leaves and pods of 24-day-old G. max var. Palmetto were surface-sterilized and inoculated by placing 10 μl of a conidial suspension (106 conidia ml-1) using either the wound/drop or non-wound/drop method (4), with 10 μl distilled water as a negative control. Leaves and pods were incubated at 25°C, 98% RH. The experiment was repeated twice. Five days after inoculation, the development of typical field symptoms, including acervuli formation, occurred on the leaves and pods of inoculated plants, but not on the negative controls. A fungus with the same colony and conidial morphology as CGM50 was recovered from the lesions on the inoculated leaves and pods. Anthracnose caused by C. gloeosporioides on soybean plants has been reported previously in different countries, but not in Malaysia (3). Geographically, the climate of Malaysia is highly conducive to maintain and cause outbreaks of anthracnose all year round; thus, the development of management recommendations will be inevitable for anthracnose control. To our knowledge, this is the first report of C. gloeosporioides causing anthracnose on soybean in Malaysia. References: (1) U. Damm et al. Fungal Diversity 39:45, 2009. (2) S. L. Chen et al. J. Phytopathol. 154:654, 2006. (3) B. C. Sutton. The Genus Glomerella and its Anamorph Colletotrichum. CAB International, Wallingford, UK, 1992. (4) P. P. Than et al. Plant Pathol. 57:562, 2008. ERRATUM: A correction was made to this Disease Note on May 19, 2014. The author N. Soleimani was added.
    Matched MeSH terms: Histones
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