At present, nuclear condensation and fragmentation have been estimated also using Hoechst probes in fluorescence microscopy and flow cytometry. However, none of the methods used the Hoechst probes for quantitative spectrofluorometric assessment. Therefore, the aim of the present study was to develop a spectrofluorometric assay for detection of nuclear condensation and fragmentation in the intact cells. We used human hepatoma HepG2 and renal HK-2 cells cultured in 96-well plates treated with potent apoptotic inducers (i.e. cisplatin, staurosporine, camptothecin) for 6-48 h. Afterwards, the cells were incubated with Hoechst 33258 (2 µg/mL) and the increase of fluorescence after binding of the dye to DNA was measured. The developed spectrofluorometric assay was capable to detect nuclear changes caused by all tested apoptotic inducers. Then, we compared the outcomes of the spectrofluorometric assay with other methods detecting cell impairment and apoptosis (i.e. WST-1 and glutathione tests, TUNEL, DNA ladder, caspase activity, PARP-1 and JNKs expressions). We found that our developed spectrofluorometric assay provided results of the same sensitivity as the TUNEL assay but with the advantages of being fast processing, low-cost and a high throughput. Because nuclear condensation and fragmentation can be typical markers of cell death, especially in apoptosis, we suppose that the spectrofluorometric assay could become a routinely used method for characterizing cell death processes.

• MeSH
• antitumorózní látky farmakologie   MeSH
• apoptóza účinky léků   MeSH
• bisbenzimidazol chemie   MeSH
• buněčná smrt účinky léků   MeSH
• buněčné jádro účinky léků   metabolismus   MeSH
• buněčné linie MeSH
• buňky Hep G2 MeSH
• cisplatina farmakologie   MeSH
• fluorescenční mikroskopie metody   MeSH
• fluorescenční spektrometrie metody   MeSH
• fragmentace DNA účinky léků   MeSH
• kamptothecin farmakologie   MeSH
• lidé MeSH
• průtoková cytometrie metody   MeSH
• reprodukovatelnost výsledků MeSH
• staurosporin farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Here, we provide evidence for the presence of Myosin phosphatase rho-interacting protein (MPRIP), an F-actin-binding protein, in the cell nucleus. The MPRIP protein binds to Phosphatidylinositol 4,5-bisphosphate (PIP2) and localizes to the nuclear speckles and nuclear lipid islets which are known to be involved in transcription. We identified MPRIP as a component of RNA Polymerase II/Nuclear Myosin 1 complex and showed that MPRIP forms phase-separated condensates which are able to bind nuclear F-actin fibers. Notably, the fibrous MPRIP preserves its liquid-like properties and reforms the spherical shaped condensates when F-actin is disassembled. Moreover, we show that the phase separation of MPRIP is driven by its long intrinsically disordered region at the C-terminus. We propose that the PIP2/MPRIP association might contribute to the regulation of RNAPII transcription via phase separation and nuclear actin polymerization.

• MeSH
• adaptorové proteiny signální transdukční chemie   metabolismus   MeSH
• aktiny metabolismus   MeSH
• buněčné jádro účinky léků   metabolismus   MeSH
• fosfatidylinositol-4,5-difosfát metabolismus   MeSH
• glykoly farmakologie   MeSH
• lidé MeSH
• myosin typu I metabolismus   MeSH
• nádorové buněčné linie MeSH
• proteinové domény MeSH
• RNA-polymerasa II metabolismus   MeSH
• subcelulární frakce metabolismus   MeSH
• vazba proteinů účinky léků   MeSH
• zelené fluorescenční proteiny metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Nuclear myosin 1 (NM1) has been implicated in key nuclear functions. Together with actin, it has been shown to initiate and regulate transcription, it is part of the chromatin remodeling complex B-WICH, and is responsible for rearrangements of chromosomal territories in response to external stimuli. Here we show that deletion of NM1 in mouse embryonic fibroblasts leads to chromatin and transcription dysregulation affecting the expression of DNA damage and cell cycle genes. NM1 KO cells exhibit increased DNA damage and changes in cell cycle progression, proliferation, and apoptosis, compatible with a phenotype resulting from impaired p53 signaling. We show that upon DNA damage, NM1 forms a complex with p53 and activates the expression of checkpoint regulator p21 (Cdkn1A) by PCAF and Set1 recruitment to its promoter for histone H3 acetylation and methylation. We propose a role for NM1 in the transcriptional response to DNA damage response and maintenance of genome stability.

• MeSH
• apoptóza MeSH
• buněčné jádro účinky léků   genetika   metabolismus   patologie   MeSH
• buněčné linie MeSH
• buněčný cyklus MeSH
• epigeneze genetická MeSH
• etoposid toxicita   MeSH
• genetická transkripce * MeSH
• histonlysin-N-methyltransferasa genetika   metabolismus   MeSH
• inhibitor p21 cyklin-dependentní kinasy genetika   metabolismus   MeSH
• myosin typu I genetika   metabolismus   MeSH
• myši MeSH
• nádorový supresorový protein p53 genetika   metabolismus   MeSH
• poškození DNA * MeSH
• proliferace buněk MeSH
• restrukturace chromatinu * MeSH
• transkripční faktory p300-CBP genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Mediator is a multiprotein complex that connects regulation mediated by transcription factors with RNA polymerase II transcriptional machinery and integrates signals from the cell regulatory cascades with gene expression. One of the Mediator subunits, Mediator complex subunit 28 (MED28), has a dual nuclear and cytoplasmic localization and function. In the nucleus, MED28 functions as part of Mediator and in the cytoplasm, it interacts with cytoskeletal proteins and is part of the regulatory cascades including that of Grb2. MED28 thus has the potential to bring cytoplasmic regulatory interactions towards the centre of gene expression regulation. In this study, we identified MDT-28, the nematode orthologue of MED28, as a likely target of lysine acetylation using bioinformatic prediction of posttranslational modifications. Lysine acetylation was experimentally confirmed using anti-acetyl lysine antibody on immunoprecipitated GFP::MDT-28 expressed in synchronized C. elegans. Valproic acid (VPA), a known inhibitor of lysine deacetylases, enhanced the lysine acetylation of GFP::MDT-28. At the subcellular level, VPA decreased the nuclear localization of GFP::MDT-28 detected by fluorescencelifetime imaging microscopy (FLIM). This indicates that the nuclear pool of MDT-28 is regulated by a mechanism sensitive to VPA and provides an indirect support for a variable relative proportion of MED28 orthologues with other Mediator subunits.

• MeSH
• acetylace MeSH
• buněčné jádro účinky léků   metabolismus   MeSH
• Caenorhabditis elegans účinky léků   metabolismus   MeSH
• denzitometrie MeSH
• jaderné proteiny chemie   metabolismus   MeSH
• kyselina valproová farmakologie   MeSH
• larva účinky léků   MeSH
• lidé MeSH
• lysin metabolismus   MeSH
• mediátorový komplex chemie   metabolismus   MeSH
• proteiny Caenorhabditis elegans chemie   metabolismus   MeSH
• rekombinantní fúzní proteiny metabolismus   MeSH
• sekvence aminokyselin MeSH
• sekvenční homologie aminokyselin * MeSH
• transport proteinů účinky léků   MeSH
• výpočetní biologie MeSH
• zelené fluorescenční proteiny metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The Hippo pathway effector, Yes-associated protein (YAP), is a transcriptional coactivator implicated in cholangiocarcinoma (CCA) pathogenesis. YAP is known to be regulated by a serine/threonine kinase relay module (MST1/2-LATS1/2) culminating in phosphorylation of YAP at Serine 127 and cytoplasmic sequestration. However, YAP also undergoes tyrosine phosphorylation, and the role of tyrosine phosphorylation in YAP regulation remains unclear. Herein, YAP regulation by tyrosine phosphorylation was examined in human and mouse CCA cells, as well as patient-derived xenograft (PDX) models. YAP was phosphorylated on tyrosine 357 (Y357) in CCA cell lines and PDX models. SRC family kinase (SFK) inhibition with dasatinib resulted in loss of YAPY357 phosphorylation, promoted its translocation from the nucleus to the cytoplasm, and reduced YAP target gene expression, including cell lines expressing a LATS1/2-resistant YAP mutant in which all serine residues were mutated to alanine. Consistent with these observations, precluding YAPY357 phosphorylation by site-directed mutagenesis (YAPY357F) excluded YAP from the nucleus. Targeted siRNA experiments identified LCK as the SFK that most potently mediated YAPY357 phosphorylation. Likewise, inducible CRISPR/Cas9-targeted LCK deletion decreased YAPY357 phosphorylation and its nuclear localization. The importance of LCK in CCA biology was demonstrated by clinical observations suggesting LCK expression levels were associated with early tumor recurrence following resection of CCA. Finally, dasatinib displayed therapeutic efficacy in PDX models. Mol Cancer Res; 16(10); 1556-67. ©2018 AACR.

• MeSH
• adaptorové proteiny signální transdukční genetika   MeSH
• buněčné jádro účinky léků   MeSH
• cholangiokarcinom farmakoterapie   genetika   patologie   MeSH
• cytoplazma účinky léků   MeSH
• dasatinib aplikace a dávkování   MeSH
• fosfoproteiny genetika   MeSH
• fosforylace účinky léků   MeSH
• lidé MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• proliferace buněk účinky léků   MeSH
• protein-serin-threoninkinasy genetika   MeSH
• regulace genové exprese u nádorů účinky léků   MeSH
• signální transdukce účinky léků   MeSH
• skupina kinas odvozených od src-genu antagonisté a inhibitory   genetika   MeSH
• tyrosin genetika   MeSH
• tyrosinkinasa p56(lck), specifická pro lymfocyty genetika   MeSH
• xenogenní modely - testy antitumorózní aktivity MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

Fuchs endothelial corneal dystrophy (FECD) is a common disease for which corneal transplantation is the only treatment option in advanced stages, and alternative treatment strategies are urgently required. Expansion (≥50 copies) of a non-coding trinucleotide repeat in TCF4 confers >76-fold risk for FECD in our large cohort of affected individuals. An FECD subject-derived corneal endothelial cell (CEC) model was developed to probe disease mechanism and investigate therapeutic approaches. The CEC model demonstrated that the repeat expansion leads to nuclear RNA foci, with the sequestration of splicing factor proteins (MBNL1 and MBNL2) to the foci and altered mRNA processing. Antisense oligonucleotide (ASO) treatment led to a significant reduction in the incidence of nuclear foci, MBNL1 recruitment to the foci, and downstream aberrant splicing events, suggesting functional rescue. This proof-of-concept study highlights the potential of a targeted ASO therapy to treat the accessible and tractable corneal tissue affected by this repeat expansion-mediated disease.

• MeSH
• antisense oligonukleotidy farmakologie   MeSH
• buněčné jádro účinky léků   metabolismus   MeSH
• endoteliální buňky metabolismus   MeSH
• expanze trinukleotidových repetic genetika   MeSH
• Fuchsova endoteliální dystrofie genetika   patologie   MeSH
• genetická predispozice k nemoci * MeSH
• kohortové studie MeSH
• lidé MeSH
• messenger RNA metabolismus   MeSH
• myši inbrední C57BL MeSH
• orgánová specificita MeSH
• posttranskripční úpravy RNA MeSH
• prekurzory RNA genetika   MeSH
• rizikové faktory MeSH
• rohovkový endotel patologie   MeSH
• senioři MeSH
• sestřihové faktory metabolismus   MeSH
• transkripční faktor 4 genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Results of a number of studies indicate that electroplaters have increased cancer risks as a consequence of exposure to genotoxic metals such as chromium (VI) and nickel. These effects may be due to induction of damage of the genetic material which plays a key role in the etiology of cancer, and it was found that workers in galvanization factories exhibited increased levels of DNA damage. The aim of the present study was to investigate genetic stability in workers of a bright plating factory who are exposed to chromium (Cr) and cobalt (Co). Exfoliated cells were collected from the buccal and nasal mucosa of workers (n = 42) and matched controls (n = 43) and analyzed for induction of micronuclei (MN) which are formed as a consequence of chromosomal aberrations. In addition, other nuclear anomalies namely nuclear buds (Nbuds) which are formed as a consequence of gene amplification and markers indicating different stages of cell death (condensed chromatin, karyorrhexis, karyolysis, and pyknosis) were also assessed. No evidence was noted for induction of MN, but significantly increased rates of Nbuds in cells from both, buccal and nasal mucosa, were found. Parameters which are indicative for cytotoxic effects were more pronounced in nasal cells and rose with duration of employment period. Overall, our findings indicated that no apparent chromosomal damage occurred in bright electroplaters. However, data demonstrated that acute cytotoxic effects may lead to inflammations and/or lesions in epithelia of the respiratory tract of the workers.

• MeSH
• buněčná smrt účinky léků   MeSH
• buněčné jádro účinky léků   MeSH
• chrom toxicita   MeSH
• dospělí MeSH
• kobalt toxicita   MeSH
• lidé MeSH
• lidské chromozomy účinky léků   MeSH
• mikrojádra chromozomálně defektní chemicky indukované   MeSH
• nosní sliznice účinky léků   MeSH
• pokovování galvanické * MeSH
• pracovní expozice škodlivé účinky   MeSH
• ústní sliznice účinky léků   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Oxidative stress and persistent activation of DNA damage response (DDR) are causally involved in the development of cellular senescence, a phenomenon implicated in fundamental (patho)physiological processes such as aging, fetal development and tumorigenesis. Here, we report that adenine nucleotide translocase-2 (ANT2) is consistently down-regulated in all three major forms of cellular senescence: replicative, oncogene-induced and drug-induced, in both normal and cancerous human cells. We previously reported formation of novel NF1/Smad transcription repressor complexes in growth-arrested fibroblasts. Here we show that such complexes form in senescent cells. Mechanistically, binding of the NF1/Smad complexes to the NF1-dependent repressor elements in the ANT2 gene promoter repressed ANT2 expression. Etoposide-induced formation of these complexes and repression of ANT2 were relatively late events co-incident with production and secretion of, and dependent on, TGF-β. siRNA-mediated knock-down of ANT2 in proliferating cells resulted in increased levels of reactive oxygen species (ROS) and activation of the DDR. Knock-down of ANT2, together with etoposide treatment, further intensified ROS production and DNA damage signaling, leading to enhanced apoptosis. Together, our data show that TGF-β-mediated suppression of ANT2 through NF1/Smad4 complexes contributes to oxidative stress and DNA damage during induction of cellular senescence.

• MeSH
• buněčné jádro účinky léků   metabolismus   MeSH
• buněčné linie MeSH
• cytoprotekce účinky léků   MeSH
• down regulace účinky léků   MeSH
• etoposid farmakologie   MeSH
• lidé MeSH
• mutace MeSH
• oxidační stres * účinky léků   MeSH
• poškození DNA MeSH
• promotorové oblasti (genetika) MeSH
• protein Smad4 metabolismus   MeSH
• represorové proteiny metabolismus   MeSH
• stárnutí buněk * účinky léků   MeSH
• transformující růstový faktor beta metabolismus   MeSH
• transkripční faktory NFI metabolismus   MeSH
• translokátor adeninových nukleotidů 2 genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Cadmium is a potent inducer of programmed cell death (PCD) in plants but the morphological changes in cells exposed to cadmium are poorly characterized. Using light and transmission electron microscopy (TEM) we have investigated the changes in ultrastructure of tobacco BY-2 cells treated with 50 µM CdSO4. The cadmium-induced alterations in cell morphology occurred gradually over a period of 3-4 days and the first stages of the response resembled vacuolar type of cell death. The initial formation of numerous small cytoplasmic vacuoles and dilation of endoplasmic reticulum was followed first by fusion of smaller vacuoles with each other and with big vacuoles, and then by the appearance of autophagic vacuoles containing autophagic bodies. The final stages of cell death were accompanied by necrotic features including loss of plasmalemma integrity, shrinkage of the protoplast and unprocessed cellular components. In addition, we observed a gradual degradation of nuclear material. Our results demonstrate that cadmium-induced plant cell death is a slow process featuring elements of vacuolar cell death and terminating with necrosis.

• MeSH
• buněčná smrt účinky léků   MeSH
• buněčné jádro účinky léků   metabolismus   ultrastruktura   MeSH
• kadmium toxicita   MeSH
• kultivované buňky MeSH
• tabák cytologie   MeSH
• tvar buňky účinky léků   MeSH
• vakuoly účinky léků   metabolismus   ultrastruktura   MeSH
• viabilita buněk účinky léků   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

AIM: The optimal balance between histone acetylation and deacetylation is important for proper gene function. Therefore, we addressed how inhibitors of histone-modifying enzymes can modulate nuclear events, including replication, transcription, splicing and DNA repair. MATERIALS & METHODS: Changes in cell signaling pathways upon treatment with histone acetyltransferases and/or histone deacetylase inhibitors were studied by cDNA microarrays and western blots. RESULTS: We analyzed the effects of the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) and the histone acetylase inhibitor MG149. SAHA altered the expression of factors involved in DNA replication complexes, basal transcription and the spliceosome pathway. DNA repair-related genes, including Rad51, Rad54 and BRCA2, were significantly downregulated by SAHA. However, MG149 had no effect on the investigated nuclear processes, with the exception of the spliceosome network and Sestrins, involved in DNA repair. CONCLUSION: Based on our results, we propose that the studied epigenetic drugs have the distinct potential to affect specific cell signaling pathways depending on their respective molecular targets.

• MeSH
• acetylace účinky léků   MeSH
• apoptóza účinky léků   MeSH
• buněčné jádro účinky léků   metabolismus   MeSH
• buňky K562 MeSH
• DNA-helikasy MeSH
• epigeneze genetická MeSH
• histonacetyltransferasy genetika   metabolismus   MeSH
• histony metabolismus   MeSH
• inhibitory histondeacetylas farmakologie   MeSH
• jaderné proteiny genetika   MeSH
• kyseliny hydroxamové farmakologie   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• nádorový supresorový protein p53 genetika   MeSH
• NF-kappa B genetika   MeSH
• oprava DNA účinky léků   MeSH
• protein BRCA2 genetika   MeSH
• regulace genové exprese MeSH
• rekombinasa Rad51 genetika   MeSH
• RNA genetika   MeSH
• sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů MeSH
• signální transdukce účinky léků   MeSH
• spliceozomy genetika   metabolismus   MeSH
• stanovení celkové genové exprese MeSH
• transkripční faktory genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH