Cíl studie: Histony se vážou sekvenčně nespecifi ckým způsobem za vzniku chromatinu. N-koncováoblast histonů je cílovým místem posttranslačních modifi kací (fosforylace a acetylace). Předpokládáse, že tyto modifi kace regulují strukturu chromatinu, a tím mohou ovlivňovat transkripci,DNA replikaci, mitotickou aktivitu a reparaci DNA. Regenerace dlaždicobuněčného epitelu jeprovázena výraznou buněčnou atypií, pleomorfi smem jádra a jadérka a tyto změny mohou býtzaměněny s obrazem neoplazie. Cílem prezentované studie je detekce fosforylované a acetylovanéformy histonu H3 v cytologických stěrech a zhodnocení získaných výsledků ve vztahu k morfologickémuobrazu cervikální intraepiteliální neoplazie.Typ studie: Aplikovaný výzkum.Název a sídlo pracoviště: Základna experimentální onkologie, Masarykův onkologický ústav,Ústav patologické fyziologie a Klinika porodnictví a gynekologie, Masarykova univerzita v Brně.Metodika: Analyzovaný soubor tvořily cytologické stěry z děložního čípku 46 žen ve věku od 20 do46 let. 10 případů dlaždicobuněčné metaplazie, 20 CIN I, 12 CIN I, a 14 CIN III. Získané stěry bylypodrobeny imunohistochemické analýze s využitím polyklonálních protilátek proti fosforylovanéa acetylované formě histonu H3.Výsledky: Jaderná pozitivita pro fosforylované (P) a acetylované (A) formy histonu H3 byla vyššíu CIN II (23 % P, 33 % A) a CIN III (25 % P, 44 % A) ve srovnání s metaplazií (11 % P, 12 % A) a CIN I(8 % P, 15 % A).Závěr: Nalezli jsme souvislost mezi průkazem modifi kací histonu H3 a výskytem pokročilé formyCIN II a CIN III ve srovnání s CIN I a metaplazií. Barvení buněk s protilátkami rozlišujícími 1. fosforylovanou formu histonu H3 představuje vysoce specifi cký marker mitózy a 2. detekceacetylované formy koreluje s lokalizací transkripční aktivity.

Objective: Histones bind in a sequence-independent manner to form chromatin. The aminoterminaltails of histones are targets for both phosphorylation and acetylation events. These modifi cationsare thought to fundamentally regulate chromatin structure to accommodate transcription,DNA replication, mitosis and DNA repair. Regeneration of squamous epithelium is accompaniedby marked cellular atypia, nuclear and nucleolar pleomorphism which could be confused withneoplasia. The aim of the study was to detect phosphorylated and acetylated forms of histone H3in cytological smears.Design: Translational research.Setting: Department of Experimental Oncology, Masaryk Memorial Cancer Institute, Departmentof Pathological Physiology, Medical Faculty and Department of Obstetrics and Gynecology, MasarykUniversity, Czech Republic.Methods: Smears from women aged between 20 to 46 years were selected. The specimens comprised10 squamous metaplasia, 20 CIN I, 12 CIN II, and 14 CIN III. The smears were stained withpolyclonal antibodies against phosphorylated and acetylated forms of histone H3.Results: We found that nuclear positivity for phosphorylated (P) and acetylated (A) forms of histoneH3 in CIN II (23% P, 33% A) and CIN III (25% P, 44% A) was higher in comparison with CIN I(8% P, 15% A) and metaplasia (11% P, 12% A).Conclusion: We revealed a marked association of histone H3 modifi cations with the progressionof CIN II, CIN III in comparison with CIN I and metaplasia. Our results are in agreement withrecent fi ndings: 1. staining of cells with anti-phospho-histone H3 antibodies therefore provides ahighly specifi c marker for mitosis. 2. acetylation of nucleosomal histones correlates with localisedtranscriptional activity.

• MeSH
• acetylace MeSH
• cytodiagnostika metody   MeSH
• dospělí MeSH
• dysplazie děložního hrdla diagnóza   patologie   MeSH
• finanční podpora výzkumu jako téma MeSH
• fosforylace MeSH
• histony fyziologie   MeSH
• imunohistochemie metody   MeSH
• lidé středního věku MeSH
• lidé MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• přehledy MeSH
• srovnávací studie MeSH

Centromeres define the chromosomal position where kinetochores form to link the chromosome to microtubules during mitosis and meiosis. Centromere identity is determined by incorporation of a specific histone H3 variant termed CenH3. As for other histones, escort and deposition of CenH3 must be ensured by histone chaperones, which handle the non-nucleosomal CenH3 pool and replenish CenH3 chromatin in dividing cells. Here, we show that the Arabidopsis orthologue of the mammalian NUCLEAR AUTOANTIGENIC SPERM PROTEIN (NASP) and Schizosaccharomyces pombe histone chaperone Sim3 is a soluble nuclear protein that binds the histone variant CenH3 and affects its abundance at the centromeres. NASPSIM3 is co-expressed with Arabidopsis CenH3 in dividing cells and binds directly to both the N-terminal tail and the histone fold domain of non-nucleosomal CenH3. Reduced NASPSIM3 expression negatively affects CenH3 deposition, identifying NASPSIM3 as a CenH3 histone chaperone.

• MeSH
• Arabidopsis metabolismus   MeSH
• centromera metabolismus   MeSH
• histony metabolismus   MeSH
• kinetochory metabolismus   MeSH
• proteiny huseníčku metabolismus   MeSH
• Schizosaccharomyces metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The parabasalid protist Trichomonas vaginalis is a widespread parasite that affects humans, frequently causing vaginitis in infected women. Trichomonad mitosis is marked by the persistence of the nuclear membrane and the presence of an asymmetric extranuclear spindle with no obvious direct connection to the chromosomes. No centromeric markers have been described in T. vaginalis, which has prevented a detailed analysis of mitotic events in this organism. In other eukaryotes, nucleosomes of centromeric chromatin contain the histone H3 variant CenH3. The principal aim of this work was to identify a CenH3 homolog in T. vaginalis. We performed a screen of the T. vaginalis genome to retrieve sequences of canonical and variant H3 histones. Three variant histone H3 proteins were identified, and the subcellular localization of their epitope-tagged variants was determined. The localization of the variant TVAG_185390 could not be distinguished from that of the canonical H3 histone. The sequence of the variant TVAG_087830 closely resembled that of histone H3. The tagged protein colocalized with sites of active transcription, indicating that the variant TVAG_087830 represented H3.3 in T. vaginalis. The third H3 variant (TVAG_224460) was localized to 6 or 12 distinct spots at the periphery of the nucleus, corresponding to the number of chromosomes in G(1) phase and G(2) phase, respectively. We propose that this variant represents the centromeric marker CenH3 and thus can be employed as a tool to study mitosis in T. vaginalis. Furthermore, we suggest that the peripheral distribution of CenH3 within the nucleus results from the association of centromeres with the nuclear envelope throughout the cell cycle.

• MeSH
• aktivace transkripce MeSH
• buněčné jádro genetika   metabolismus   MeSH
• centromera genetika   metabolismus   MeSH
• chromozomy genetika   metabolismus   MeSH
• fluorescenční mikroskopie MeSH
• G1 fáze MeSH
• G2 fáze MeSH
• genom protozoální MeSH
• histony genetika   metabolismus   MeSH
• jaderný obal metabolismus   MeSH
• mitóza MeSH
• molekulární sekvence - údaje MeSH
• nukleozomy metabolismus   MeSH
• protozoální proteiny genetika   metabolismus   MeSH
• sekvence aminokyselin MeSH
• sekvenční analýza proteinů MeSH
• transformace genetická MeSH
• Trichomonas vaginalis genetika   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The effects of the histone deacetylase inhibitors (HDACi) trichostatin A (TSA) and sodium butyrate (NaBt) were studied in A549, HT29 and FHC human cell lines. Global histone hyperacetylation, leading to decondensation of interphase chromatin, was characterized by an increase in H3(K9) and H3(K4) dimethylation and H3(K9) acetylation. The levels of all isoforms of heterochromatin protein, HP1, were reduced after HDAC inhibition. The observed changes in the protein levels were accompanied by changes in their interphase patterns. In control cells, H3(K9) acetylation and H3(K4) dimethylation were substantially reduced to a thin layer at the nuclear periphery, whereas TSA and NaBt caused the peripheral regions to become intensely acetylated at H3(K9) and dimethylated at H3(K4). The dispersed pattern of H3(K9) dimethylation was stable even at the nuclear periphery of HDACi-treated cells. After TSA and NaBt treatment, the HP1 proteins were repositioned more internally in the nucleus, being closely associated with interchromatin compartments, while centromeric heterochromatin was relocated closer to the nuclear periphery. These findings strongly suggest dissociation of HP1 proteins from peripherally located centromeres in a hyperacetylated and H3(K4) dimethylated environment. We conclude that inhibition of histone deacetylases caused dynamic reorganization of chromatin in parallel with changes in its epigenetic modifications.

• MeSH
• apoptóza účinky záření   MeSH
• buněčné jádro enzymologie   genetika   metabolismus   účinky léků   MeSH
• buněčné linie MeSH
• buněčný cyklus účinky léků   MeSH
• buňky HT-29 MeSH
• chromatin metabolismus   MeSH
• chromozomální proteiny, nehistonové antagonisté a inhibitory   metabolismus   MeSH
• financování organizované MeSH
• histondeacetylasy metabolismus   MeSH
• histony metabolismus   MeSH
• inhibitory enzymů farmakologie   MeSH
• inhibitory histondeacetylas MeSH
• interfáze účinky léků   MeSH
• kyselina máselná farmakologie   MeSH
• kyseliny hydroxamové farmakologie   MeSH
• lidé MeSH
• malobuněčný karcinom enzymologie   metabolismus   patologie   MeSH
• nádorové buněčné linie MeSH
• nádory plic enzymologie   metabolismus   patologie   MeSH
• nádory tračníku enzymologie   metabolismus   patologie   MeSH
• plod MeSH
• Check Tag
• lidé MeSH

The phosphorylation of histone H3 at Ser10, Ser28, Thr11 and Thr3 of the amino terminal has been proved related to mitosis of the mammalian cells. However, the function of the Thr3 phosphorylation of H3 remains unclear. In this study, indirect immunofluorescence labelling and laser confocal microscopy were used to examine the cellular dynamic distribution of Thr3-phosphorylated H3 at mitosis in CHO cells. The results showed that the Thr3 phosphorylation began at early prophase and spread throughout the chromosomes at late prophase. At metaphase, most of the Thr3-phosphorylated H3 was distributed along the entire chromosomal arms and maintained until early anaphase. During late anaphase and telophase, the fluorescent signal of Thr3-phosphorylated H3 disappeared from chromosomes. There was a precise spatial and temporal correlation between H3 phosphorylation of Thr3 and stages of chromatin condensation. The timing of Thr3 phosphorylation and dephosphorylation in mitosis were similar to that reported for Thr11 phosphorylation of H3. The Thr3-phosphorylated H3 localized along the arms of chromosomes during metaphase and early anaphase. It was different from the Ser10-phosphorylated H3, which localized at telomere regions, and Thr11-phosphorylated H3, which localized at centromeres. The results suggest that the Thr3 phosphorylation of histone H3 may play a specific role, which is different from Ser10 phosphorylation and Thr11 phosphorylation in mitosis.

• MeSH
• CHO buňky cytologie   účinky léků   MeSH
• chromatin genetika   MeSH
• financování vládou MeSH
• fluorescenční mikroskopie metody   využití   MeSH
• fosforylace fyziologie   MeSH
• histony genetika   účinky léků   MeSH
• mitóza fyziologie   genetika   MeSH
• western blotting metody   využití   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• srovnávací studie MeSH

Chronically undernourished children become stunted during their first 2 years and thereafter bear burdens of ill health for the rest of their lives. Contributors to stunting include poor nutrition and exposure to pathogens, and parental history may also play a role. However, the epigenetic impact of a poor environment on young children is largely unknown. Here we show the unfolding pattern of histone H3 lysine 4 trimethylation (H3K4me3) in children and mothers living in an urban slum in Dhaka, Bangladesh. A pattern of chromatin modification in blood cells of stunted children emerges over time and involves a global decrease in methylation at canonical locations near gene start sites and increased methylation at ectopic sites throughout the genome. This redistribution occurs at metabolic and immune genes and was specific for H3K4me3, as it was not observed for histone H3 lysine 27 acetylation in the same samples. Methylation changes in stunting globally resemble changes that occur in vitro in response to altered methylation capacity, suggesting that reduced levels of one-carbon nutrients in the diet play a key role in stunting in this population. A network of differentially expressed genes in stunted children reveals effects on chromatin modification machinery, including turnover of H3K4me3, as well as posttranscriptional gene regulation affecting immune response pathways and lipid metabolism. Consistent with these changes, reduced expression of the endocytic receptor gene LDL receptor 1 (LRP1) is a driver of stunting in a mouse model, suggesting a target for intervention.

• MeSH
• epigeneze genetická MeSH
• histony genetika   MeSH
• kojenec MeSH
• lidé MeSH
• metylace MeSH
• myši MeSH
• novorozenec MeSH
• podvýživa genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• kojenec MeSH
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• novorozenec MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

• MeSH
• autoprotilátky krev   MeSH
• deoxyribonukleoproteiny MeSH
• DNA MeSH
• ELISA MeSH
• histony MeSH
• lidé MeSH
• nemoci pojiva imunologie   krev   MeSH
• systémový lupus erythematodes imunologie   krev   MeSH
• Check Tag
• lidé MeSH

• MeSH
• chromatin MeSH
• hepatocelulární adenom MeSH
• histocytochemie MeSH
• histony MeSH
• játra cytologie   MeSH
• krysa rodu rattus MeSH
• proteasy analýza   MeSH
• Check Tag
• krysa rodu rattus MeSH

• MeSH
• histony MeSH
• krevní oběh MeSH
• kuřecí embryo MeSH
• mezonefros MeSH
• Check Tag
• kuřecí embryo MeSH

Speciation genes restrict gene flow between the incipient species and related taxa. Three decades ago, we mapped a mammalian speciation gene, hybrid sterility 1 (Hst1), in the intersubspecific hybrids of house mouse. Here, we identify this gene as Prdm9, encoding a histone H3 lysine 4 trimethyltransferase. We rescued infertility in male hybrids with bacterial artificial chromosomes carrying Prdm9 from a strain with the "fertility" Hst1(f) allele. Sterile hybrids display down-regulated microrchidia 2B (Morc2b) and fail to compartmentalize gammaH2AX into the pachynema sex (XY) body. These defects, seen also in Prdm9-null mutants, are rescued by the Prdm9 transgene. Identification of a vertebrate hybrid sterility gene reveals a role for epigenetics in speciation and opens a window to a hybrid sterility gene network.

• MeSH
• epigeneze genetická MeSH
• financování organizované MeSH
• histonlysin-N-methyltransferasa genetika   chemie   metabolismus   MeSH
• histony metabolismus   MeSH
• hybridizace genetická MeSH
• křížení genetické MeSH
• mapování chromozomů MeSH
• meióza MeSH
• metylace MeSH
• molekulární sekvence - údaje MeSH
• mužská infertilita genetika   MeSH
• myši inbrední C3H MeSH
• myši transgenní MeSH
• myši MeSH
• ovarium enzymologie   MeSH
• regulace genové exprese MeSH
• sekvence aminokyselin MeSH
• testis enzymologie   MeSH
• umělé bakteriální chromozomy MeSH
• vznik druhů (genetika) MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH