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Sample records for c-jun controls histone

  1. Dynamic acetylation of all lysine 4-methylated histone H3 in the mouse nucleus: analysis at c-fos and c-jun.

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    Catherine A Hazzalin

    2005-12-01

    Full Text Available A major focus of current research into gene induction relates to chromatin and nucleosomal regulation, especially the significance of multiple histone modifications such as phosphorylation, acetylation, and methylation during this process. We have discovered a novel physiological characteristic of all lysine 4 (K4-methylated histone H3 in the mouse nucleus, distinguishing it from lysine 9-methylated H3. K4-methylated histone H3 is subject to continuous dynamic turnover of acetylation, whereas lysine 9-methylated H3 is not. We have previously reported dynamic histone H3 phosphorylation and acetylation as a key characteristic of the inducible proto-oncogenes c-fos and c-jun. We show here that dynamically acetylated histone H3 at these genes is also K4-methylated. Although all three modifications are proven to co-exist on the same nucleosome at these genes, phosphorylation and acetylation appear transiently during gene induction, whereas K4 methylation remains detectable throughout this process. Finally, we address the functional significance of the turnover of histone acetylation on the process of gene induction. We find that inhibition of turnover, despite causing enhanced histone acetylation at these genes, produces immediate inhibition of gene induction. These data show that all K4-methylated histone H3 is subject to the continuous action of HATs and HDACs, and indicates that at c-fos and c-jun, contrary to the predominant model, turnover and not stably enhanced acetylation is relevant for efficient gene induction.

  2. Interplay between viral Tat protein and c-Jun transcription factor in controlling LTR promoter activity in different human immunodeficiency virus type I subtypes.

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    van der Sluis, Renée M; Derking, Ronald; Breidel, Seyguerney; Speijer, Dave; Berkhout, Ben; Jeeninga, Rienk E

    2014-04-01

    HIV-1 transcription depends on cellular transcription factors that bind to sequences in the long-terminal repeat (LTR) promoter. Each HIV-1 subtype has a specific LTR promoter configuration, and minor sequence changes in transcription factor binding sites (TFBSs) or their arrangement can influence transcriptional activity, virus replication and latency properties. Previously, we investigated the proviral latency properties of different HIV-1 subtypes in the SupT1 T cell line. Here, subtype-specific latency and replication properties were studied in primary PHA-activated T lymphocytes. No major differences in latency and replication capacity were measured among the HIV-1 subtypes. Subtype B and AE LTRs were studied in more detail with regard to a putative AP-1 binding site using luciferase reporter constructs. c-Jun, a member of the AP-1 transcription factor family, can activate both subtype B and AE LTRs, but the latter showed a stronger response, reflecting a closer match with the consensus AP-1 binding site. c-Jun overexpression enhanced Tat-mediated transcription of the viral LTR, but in the absence of Tat inhibited basal promoter activity. Thus, c-Jun can exert a positive or negative effect via the AP-1 binding site in the HIV-1 LTR promoter, depending on the presence or absence of Tat.

  3. Expression of c-Jun and Sox-2 in human schwannomas and traumatic neuromas.

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    Shivane, Aditya; Parkinson, David B; Ammoun, Sylwia; Hanemann, Clemens O

    2013-03-01

    Schwann cells myelinate axons of the peripheral nervous system. This process of myelination is regulated by various transcription factors. c-Jun and Sox-2 are negative regulators of myelination and control Schwann cell differentiation and plasticity. Schwannoma cells within tumours no longer express myelin markers, and show increased proliferation and decreased apoptosis. We have shown previously that several signalling pathways are activated in schwannoma cells in situ, in particular the c-Jun N-terminal kinase (JNK) pathway. Both in vitro and in vivo we have demonstrated that c-Jun and Sox-2 are co-regulated in Schwann cells and evidence shows that both these proteins regulate myelination negatively. In this study, we aimed to characterize the expression of c-Jun and Sox-2 in schwannoma and traumatic neuroma. Immunohistochemistry using antibodies to c-Jun and Sox-2 was applied to six schwannomas, and the results were compared with those seen in traumatic neuroma and normal nerve. Increased expression of c-Jun and Sox-2 was seen in schwannoma. We have demonstrated increased expression of c-Jun and Sox-2 in schwannoma compared to traumatic neuroma. There was no expression of c-Jun and Sox-2 in a histologically normal peripheral nerve. © 2012 Blackwell Publishing Ltd.

  4. Anthrax lethal toxin rapidly reduces c-Jun levels by inhibiting c-Jun gene transcription and promoting c-Jun protein degradation.

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    Ouyang, Weiming; Guo, Pengfei; Fang, Hui; Frucht, David M

    2017-10-27

    Anthrax is a life-threatening disease caused by infection with Bacillus anthracis , which expresses lethal factor and the receptor-binding protective antigen. These two proteins combine to form anthrax lethal toxin (LT), whose proximal targets are mitogen-activated kinase kinases (MKKs). However, the downstream mediators of LT toxicity remain elusive. Here we report that LT exposure rapidly reduces the levels of c-Jun, a key regulator of cell proliferation and survival. Blockade of proteasome-dependent protein degradation with the 26S proteasome inhibitor MG132 largely restored c-Jun protein levels, suggesting that LT promotes degradation of c-Jun protein. Using the MKK1/2 inhibitor U0126, we further show that MKK1/2-Erk1/2 pathway inactivation similarly reduces c-Jun protein, which was also restored by MG132 pre-exposure. Interestingly, c-Jun protein rebounded to normal levels 4 h following U0126 exposure but not after LT exposure. The restoration of c-Jun in U0126-exposed cells was associated with increased c-Jun mRNA levels and was blocked by inactivation of the JNK1/2 signaling pathway. These results indicate that LT reduces c-Jun both by promoting c-Jun protein degradation via inactivation of MKK1/2-Erk1/2 signaling and by blocking c-Jun gene transcription via inactivation of MKK4-JNK1/2 signaling. In line with the known functions of c-Jun, LT also inhibited cell proliferation. Ectopic expression of LT-resistant MKK2 and MKK4 variants partially restored Erk1/2 and JNK1/2 signaling in LT-exposed cells, enabling the cells to maintain relatively normal c-Jun protein levels and cell proliferation. Taken together, these findings indicate that LT reduces c-Jun protein levels via two distinct mechanisms, thereby inhibiting critical cell functions, including cellular proliferation.

  5. Selection and characterization of a DNA aptamer that can discriminate between cJun/cJun and cJun/cFos.

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    Ryan D Walters

    Full Text Available The AP-1 family of transcriptional activators plays pivotal roles in regulating a wide range of biological processes from the immune response to tumorigenesis. Determining the roles of specific AP-1 dimers in cells, however, has remained challenging because common molecular biology techniques are unable to distinguish between the role of, for example, cJun/cJun homodimers versus cJun/cFos heterodimers. Here we used SELEX (systematic evolution of ligands by exponential enrichment to identify and characterize DNA aptamers that are >100-fold more specific for binding cJun/cJun compared to cJun/cFos, setting the foundation to investigate the biological functions of different AP-1 dimer compositions.

  6. [Expression of c-jun protein after experimental rat brain concussion].

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    Wang, Feng; Li, Yong-hong

    2010-02-01

    To observe e-jun protein expression after rat brain concussion and explore the forensic pathologic markers following brain concussion. Fifty-five rats were randomly divided into brain concussion group and control group. The expression of c-jun protein was observed by immunohistochemistry. There were weak positive expression of c-jun protein in control group. In brain concussion group, however, some neutrons showed positive expression of c-jun protein at 15 min after brain concussion, and reach to the peak at 3 h after brain concussion. The research results suggest that detection of c-jun protein could be a marker to determine brain concussion and estimate injury time after brain concussion.

  7. A Molecular Circuit Composed of CPEB-1 and c-Jun Controls Growth Hormone-Mediated Synaptic Plasticity in the Mouse Hippocampus

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    Zearfoss, N. Ruth; Alarcon, Juan Marcos; Trifilieff, Pierre; Kandel, Eric; Richter, Joel D.

    2008-01-01

    Cytoplasmic polyadenylation element binding protein 1 (CPEB-1) resides at postsynaptic sites in hippocampal neurons in which it controls polyadenylation-induced translation. CPEB-1 knock-out (KO) mice display defects in some forms of synaptic plasticity and hippocampal-dependent memories. To identify CPEB-1-regulated mRNAs, we used proteomics to compare polypeptides in wild-type (WT) and CPEB-1 KO hippocampus. Growth hormone (GH) was reduced in the KO hippocampus, as were the GH signaling mol...

  8. Tumor Necrosis Factor-α and Apoptosis Signal-Regulating Kinase 1 Control Reactive Oxygen Species Release, Mitochondrial Autophagy and C-Jun N-Terminal Kinase/P38 Phosphorylation During Necrotizing Enterocolitis

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    Naira Baregamian

    2009-01-01

    Full Text Available Background: Oxidative stress and inflammation may contribute to the disruption of the protective gut barrier through various mechanisms; mitochondrial dysfunction resulting from inflammatory and oxidative injury may potentially be a significant source of apoptosis during necrotizing enterocolitis (NEC. Tumor necrosis factor (TNFα is thought to generate reactive oxygen species (ROS and activate the apoptosis signal-regulating kinase 1 (ASK1-c-Jun N-terminal kinase (JNK/p38 pathway. Hence, the focus of our study was to examine the effects of TNFα/ROs on mitochondrial function, ASK1-JNK/p38 cascade activation in intestinal epithelial cells during NEC.

  9. IL-6, IL-10, c-Jun and STAT3 expression in B-CLL.

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    Antosz, Halina; Wojciechowska, Katarzyna; Sajewicz, Joanna; Choroszyńska, Dorota; Marzec-Kotarska, Barbara; Osiak, Magdalena; Pająk, Natalia; Tomczak, Waldemar; Jargiełło-Baszak, Małgorzata; Baszak, Jacek

    2015-03-01

    Chronic lymphocytic leukemia is characterized by the accumulation of functionally abnormal, monoclonal B lymphocytes in the peripheral blood, bone marrow, lymph nodes and spleen, resulting in a reduction count of normal immunocompetent cells and their impaired immune function. The defect in transmission of signals from various types of extracellular receptors, leading to aberrant cytokines and transcription factors gene expression, may underlie the basis of immune failure in B-CLL. The aim of the study was to assess of IL-6, IL-10, c-Jun, and STAT3 expression. In response to antigenic stimulation IL-6, IL-10, c-Jun, and STAT3 proteins induce mutual activity. The subject of the study was subpopulations of leukemic lymphocytes (CD5+ CD19+) and CD19+ B cells from healthy donors (control group). Our results provide evidence that the regulation of IL-6, IL-10, c-Jun, and STAT3 gene expression in CLL B cells is clearly different from normal B lymphocytes. In B-CLL STAT3 expression in unstimulated lymphocytes is significantly higher (pCLL in comparison with the control group, in all cases (pCLL stage according Rai we revealed decreasing c-Jun expression, both at the mRNA and protein levels, along with advancing stage of disease. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. c-Jun is involved in interstitial cystitis antiproliferative factor (APF)-induced growth inhibition of human bladder cancer T24 cells.

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    Li, Zeliang; Zhu, Yuyan; Yu, Meng; Ji, Decai; Yang, Zhenxing; Kong, Chuize

    2013-02-01

    To uncover the role of c-Jun, a proto-oncogene, in inhibitory effects of antiproliferative factor (APF) on tumor cell growth. Expression of c-Jun was analyzed by Western blotting in 45 clinical specimens (30 tumorous tissues and 15 paired non-tumorous tissues) and 3 bladder cancer cell lines. APF-responsive T24 transitional carcinoma bladder cells were treated with APF or mock control. Cell proliferation was measured by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay. Change of c-Jun expression was detected by RT-PCR and Western blotting. The influence of c-Jun on APF treatment was evaluated by transient transfection of c-Jun and MTT assay in T24 cells. c-Jun was significantly higher in invasive bladder cancer tissues and cell lines. T24 cells treated with APF had decreased c-Jun expression and suppressed cell growth. More importantly, ectopic c-Jun attenuated APF inhibitory effects on cell growth. These observations suggest that c-Jun is involved in APF-mediated inhibition for bladder tumor cell growth, as potential target of APF in patients with aggressive bladder carcinoma. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. c-Jun-N-terminal phosphorylation regulates DNMT1 expression and genome wide methylation in gliomas.

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    Heiland, Dieter H; Ferrarese, Roberto; Claus, Rainer; Dai, Fangping; Masilamani, Anie P; Kling, Eva; Weyerbrock, Astrid; Kling, Teresia; Nelander, Sven; Carro, Maria S

    2017-01-24

    High-grade gliomas (HGG) are the most common brain tumors, with an average survival time of 14 months. A glioma-CpG island methylator phenotype (G-CIMP), associated with better clinical outcome, has been described in low and high-grade gliomas. Mutation of IDH1 is known to drive the G-CIMP status. In some cases, however, the hypermethylation phenotype is independent of IDH1 mutation, suggesting the involvement of other mechanisms. Here, we demonstrate that DNMT1 expression is higher in low-grade gliomas compared to glioblastomas and correlates with phosphorylated c-Jun. We show that phospho-c-Jun binds to the DNMT1 promoter and causes DNA hypermethylation. Phospho-c-Jun activation by Anisomycin treatment in primary glioblastoma-derived cells attenuates the aggressive features of mesenchymal glioblastomas and leads to promoter methylation and downregulation of key mesenchymal genes (CD44, MMP9 and CHI3L1). Our findings suggest that phospho-c-Jun activates an important regulatory mechanism to control DNMT1 expression and regulate global DNA methylation in Glioblastoma.

  12. Modelling the mechanism of GR/c-Jun/Erg crosstalk in apoptosis of acute lymphoblastic leukaemia

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    Daphne eChen

    2012-11-01

    Full Text Available Acute lymphoblastic leukaemia (ALL is one of the most common forms of malignancy that occurs in lymphoid progenitor cells, particularly in children. Synthetic steroid hormones glucocorticoids (GCs are widely used as part of the ALL treatment regimens due to their apoptotic function, but their use also brings about various side effects and drug resistance. The identification of the molecular differences between the GCs responsive and resistant cells therefore are essential to decipher such complexity and can be used to improve therapy. However, the emerging picture is complicated as the activities of genes and proteins involved are controlled by multiple factors. By adapting the systems biology framework to address this issue, we here integrated the available knowledge together with experimental data via the building of a series of mathematical models. This rationale enabled us to unravel molecular interactions involving c-Jun in GC induced apoptosis and identify Erg as determinant for GC resistance. The results revealed an alternative potential mechanism where c-Jun may be an indirect GR target that is controlled via an upstream repressor protein. The models also highlight the importance of Erg for GR function, particularly in GC sensitive C7 cells where Erg directly regulates GR in agreement with our previous experimental results. Our models describe potential GR-controlled molecular mechanisms of c-Jun/Bim and Erg regulation. We also demonstrate the importance of using a systematic approach to translate human disease processes into computational models in order to derive information-driven new hypotheses.

  13. Modeling the Mechanism of GR/c-Jun/Erg Crosstalk in Apoptosis of Acute Lymphoblastic Leukemia.

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    Chen, Daphne Wei-Chen; Krstic-Demonacos, Marija; Schwartz, Jean-Marc

    2012-01-01

    Acute lymphoblastic leukemia (ALL) is one of the most common forms of malignancy that occurs in lymphoid progenitor cells, particularly in children. Synthetic steroid hormones glucocorticoids (GCs) are widely used as part of the ALL treatment regimens due to their apoptotic function, but their use also brings about various side effects and drug resistance. The identification of the molecular differences between the GCs responsive and resistant cells therefore are essential to decipher such complexity and can be used to improve therapy. However, the emerging picture is complicated as the activities of genes and proteins involved are controlled by multiple factors. By adopting the systems biology framework to address this issue, we here integrated the available knowledge together with experimental data by building a series of mathematical models. This rationale enabled us to unravel molecular interactions involving c-Jun in GC induced apoptosis and identify Ets-related gene (Erg) as potential biomarker of GC resistance. The results revealed an alternative possible mechanism where c-Jun may be an indirect GR target that is controlled via an upstream repressor protein. The models also highlight the importance of Erg for GR function, particularly in GC sensitive C7 cells where Erg directly regulates GR in agreement with our previous experimental results. Our models describe potential GR-controlled molecular mechanisms of c-Jun/Bim and Erg regulation. We also demonstrate the importance of using a systematic approach to translate human disease processes into computational models in order to derive information-driven new hypotheses.

  14. Elevated cJUN expression and an ATF/CRE site within the ATF3 promoter contribute to activation of ATF3 transcription by the amino acid response.

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    Fu, Lingchen; Kilberg, Michael S

    2013-02-15

    Mammalian cells respond to amino acid deprivation through multiple signaling pathways referred to as the amino acid response (AAR). Transcription factors mediate the AAR after their activation by several mechanisms; examples include translational control (activating transcription factor 4, ATF4), phosphorylation (p-cJUN), and transcriptional control (ATF3). ATF4 induces ATF3 transcription through a promoter-localized C/EBP-ATF response element (CARE). The present report characterizes an ATF/CRE site upstream of the CARE that also contributes to AAR-induced ATF3 transcription. ATF4 binds to the ATF/CRE and CARE sequences and both are required for a maximal response to ATF4 induction. ATF3, which antagonizes ATF4 and represses its own gene, also exhibited binding activity to the ATF/CRE and CARE sequences. The AAR resulted in elevated total cJUN and p-cJUN protein levels and both forms exhibited binding activity to the ATF/CRE and CARE ATF3 sequences. Knockdown of AAR-enhanced cJUN expression blocked induction of the ATF3 gene and mutation of either the ATF/CRE or the CARE site prevented the cJUN-dependent increase in ATF3-driven luciferase activity. The results indicate that both increased cJUN and the cis-acting ATF/CRE sequence within the ATF3 promoter contribute to the transcriptional activation of the gene during the AAR.

  15. Critical role of c-Jun overexpression in liver metastasis of human breast cancer xenograft model

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    Qian Lu

    2007-08-01

    Full Text Available Abstract Background c-Jun/AP-1 has been linked to invasive properties of aggressive breast cancer. Recently, it has been reported that overexpression of c-Jun in breast cancer cell line MCF-7 resulted in increased AP-1 activity, motility and invasiveness of the cells in vitro and tumor formation in nude mice. However, the role of c-Jun in metastasis of human breast cancer in vivo is currently unknown. Methods To further investigate the direct involvement of c-Jun in tumorigenesis and metastasis, in the present study, the effects of c-Jun overexpression were studied in both in vitro and in nude mice. Results Ectopic overexpression of c-Jun promoted the growth of MCF-7 cells and resulted in a significant increase in the percentage of cells in S phase and increased motility and invasiveness. Introduction of c-Jun gene alone into weakly invasive MCF-7 cells resulted in the transfected cells capable of metastasizing to the nude mouse liver following tail vein injection. Conclusion The present study confirms that overexpression of c-Jun contributes to a more invasive phenotype in MCF-7 cells. It indicates an interesting relationship between c-Jun expression and increased property of adhesion, migration and in vivo liver metastasis of MCF-7/c-Jun cells. The results provide further evidence that c-Jun is involved in the metastasis of breast cancer. The finding also opens an opportunity for development of anti-c-Jun strategies in breast cancer therapy.

  16. PTEN Interacts with Histone H1 and Controls Chromatin Condensation

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    Chen, Zhu Hong; Zhu, Minglu; Yang, Jingyi; Liang, Hui; He, Jinxue; He, Shiming; Wang, Pan; Kang, Xi; McNutt, Michael A.; Yin, Yuxin; Shen, Wen H.

    2014-01-01

    SUMMARY Chromatin organization and dynamics are integral to global gene transcription. Histone modification influences chromatin status and gene expression. PTEN plays multiple roles in tumor suppression, development and metabolism. Here we report on the interplay of PTEN, histone H1 and chromatin. We show that loss of PTEN leads to dissociation of histone H1 from chromatin and decondensation of chromatin. PTEN deletion also results in elevation of histone H4 acetylation at lysine 16, an epigenetic marker for chromatin activation. We found that PTEN and histone H1 physically interact through their C-terminal domains. Disruption of the PTEN C-terminus promotes the chromatin association of MOF acetyltransferase and induces H4K16 acetylation. Hyperacetylation of H4K16 impairs the association of PTEN with histone H1, which constitutes regulatory feedback that may deteriorate chromatin stability. Our results demonstrate that PTEN controls chromatin condensation, thus influencing gene expression. We propose that PTEN regulates global gene transcription profiling through histones and chromatin remodeling. PMID:25199838

  17. Tristetraprolin induces cell cycle arrest in breast tumor cells through targeting AP-1/c-Jun and NF-κB pathway.

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    Xu, Li; Ning, Huan; Gu, Ling; Wang, Qinghong; Lu, Wenbao; Peng, Hui; Cui, Weiguang; Ying, Baoling; Ross, Christina R; Wilson, Gerald M; Wei, Lin; Wold, William S M; Liu, Jianguo

    2015-12-08

    The main characteristic of cancers, including breast cancer, is the ability of cancer cells to proliferate uncontrollably. However, the underlying mechanisms of cancer cell proliferation, especially those regulated by the RNA binding protein tristetraprolin (TTP), are not completely understood. In this study, we found that TTP inhibits cell proliferation in vitro and suppresses tumor growth in vivo through inducing cell cycle arrest at the S phase. Our studies demonstrate that TTP inhibits c-Jun expression through the C-terminal Zn finger and therefore increases Wee1 expression, a regulatory molecule which controls cell cycle transition from the S to the G2 phase. In contrast to the well-known function of TTP in regulating mRNA stability, TTP inhibits c-Jun expression at the level of transcription by selectively blocking NF-κB p65 nuclear translocation. Reconstitution of NF-κB p65 completely abolishes the inhibition of c-Jun transcription by TTP. Moreover, reconstitution of c-Jun in TTP-expressing breast tumor cells diminishes Wee1 overexpression and promotes cell proliferation. Our results indicate that TTP suppresses c-Jun expression that results in Wee1 induction which causes cell cycle arrest at the S phase and inhibition of cell proliferation. Our study provides a new pathway for TTP function as a tumor suppressor which could be targeted in tumor treatment.

  18. Radiation-induced apoptosis in developing rats and kainic acid-induced excitotoxicity in adult rats are associated with distinctive morphological and biochemical c-Jun/AP-1 (N) expression

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    Pozas, E. [Unitat de Neuropatologia, Servei d' Anatomia Patologica, Hospital Princeps d' Espanya, Universitat de Barcelona, 08907 Hospitalet de Llobregat (Spain); Planas, A.M. [Departament de Farmacologia i Toxicologia, IIBB, CSIC Barcelona (Spain); Ferrer, I. [Unitat de Neuropatologia, Servei d' Anatomia Patologica, Hospital Princeps d' Espanya, Universitat de Barcelona, 08907 Hospitalet de Llobregat (Spain)

    1997-07-14

    Ionizing radiation produces apoptosis in the developing rat brain. Strong c-Jun immunoreactivity, as revealed with the antibody c-Jun/AP-1 (N) which is raised against the amino acids 91-105 mapping with the amino terminal domain of mouse c-Jun p39, is simultaneously observed in the nucleus and cytoplasm of apoptotic cells. Western blotting of total brain homogenates, using the same antibody, shows a p39 band in control rats which is accompanied by a strong, phosphorylated p62 double-band in irradiated animals. In addition, increased c-Jun N-terminal kinase 1 expression, as found on western blots, is found in irradiated rats when compared with controls. Intraperitoneal injection of kainic acid at convulsant doses to the adult rat produces cell death with morphological features of necrosis, together with the appearance of cells with fine granular chromatin degeneration and small numbers of apoptotic-like cells, in the entorhinal and piriform cortices, basal amygdala, certain thalamic nuclei, and CA1 region of the hippocampus. c-Jun expression in kainic acid-treated rats, as revealed with the c-Jun/AP-1 (N) antibody, is found in the nuclei of a minority of cells in the same areas. The vast majority of c-Jun-immunoreactive cells have normal nuclear morphology, whereas necrotic cells are negative and only a few cells with fine granular chromatin condensation and apoptotic cells following kainic acid injection are stained with c-Jun antibodies. Western blotting, using the same antibody, shows a p39 band in control rats, which is accompanied by a band at about p26 from 6 h onwards following kainic acid injection. Decreased c-Jun N-terminal kinase 1 expression, as revealed on western blots, is observed in kainic acid-treated rats.These results show that the antibody c-Jun/AP-1 (N) recognizes three different forms of c-Jun-related immunoreactivity in normal and pathological states, which are associated with the different outcome of cells. These results stress the necessity

  19. C-Jun expression in lichen planus, psoriasis and cutaneous squamous cell carcinoma, an immunohistochemical study.

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    Abdou, Asmaa Gaber; Marae, Alaa Hassan; Shoeib, Mohammed; Dawood, Ghada; Abouelfath, Enas

    2017-11-16

    The AP-1 transcription factor complex is a key player in regulating inflammatory processes, cell proliferation, differentiation and cell transformation. The aim of the present study is to investigate C-Jun (one of AP-1complex) expression and its proliferative role in skin samples of lichen planus, psoriasis as common inflammatory skin diseases and squamous cell carcinoma using immunohistochemical method. The present study was carried out on skin biopsies of 15 psoriatic patients, 15 lichen planus patients, 15 SCC and 15 normal skin biopsies. Nuclear expression of C-Jun was detected in basal and few suprabasal layers of epidermis of normal skin. C-Jun was expressed in the whole epidermal layers of both psoriasis (14/15) and lichen planus (15/15) in addition to its expression in lymphocytic infiltrate in the latter in about half of cases (8/15). C-Jun was also expressed in 93.3% (14/15) of SCC in a percentage lower than that of psoriasis, lichen planus and normal skin. The percentage of C-Jun expression in SCC was significantly associated with an early stage (p = 0.000), free surgical margins (p = 0.022) and small tumor size (p = 0.003). The marked reduction of C-Jun in SCC in comparison to normal skin and inflammatory skin dermatoses may refer to its tumor suppressor activity. C-Jun expression in SCC carries favorable prognosis. Absence of significant association between C-Jun and Ki-67 either in SCC or inflammatory skin diseases indicates that it does not affect proliferative capacity of cells.

  20. c-jun gene expression in human cells exposed to either ionizing radiation or hydrogen peroxide

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    Collart, F.R.; Horio, M.; Huberman, E.

    1993-06-01

    We investigated the role of reactive oxygen intermediates (ROIs) and protein kinase C (PKC) in radiation- and H{sub 2}O{sub 2}-evoked c-jun gene expression in human HL-205 cells. This induction of c-jun gene expression could be prevented by pretreatment of the cells with Nacetylcysteine (an antioxidant) or H7 (a PKC and PKA inhibitor) but not by HA1004, a PKA inhibitor, suggesting a role for ROls and PKC in mediating c-jun gene expression. We also investigated potential differences in c-jun gene expression in a panel of normal and tumor cells untreated or treated with ionizing radiation or H{sub 2}O{sub 2}. Treatment with radiation or H{sub 2}O{sub 2} produced a varied response, from some reduction to an increase of more than an order of magnitude in the steady-state level of c-jun mRNA. These data indicate that although induction of c-jun may be a common response to ionizing radiation and H{sub 2}O{sub 2}, this response was reduced or absent in some cell types.

  1. The MEKK1 SWIM domain is a novel substrate receptor for c-Jun ubiquitylation.

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    Rieger, Michael A; Duellman, Tyler; Hooper, Christopher; Ameka, Magdalene; Bakowska, Joanna C; Cuevas, Bruce D

    2012-08-01

    MEKK1 [MAPK (mitogen-activated protein kinase)/ERK (extracellular-signal-regulated kinase) kinase kinase 1] is a MAP3K (MAPK kinase kinase) that regulates MAPK activation, and is the only known mammalian kinase that is also a ubiquitin ligase. MEKK1 contains a RING domain within its N-terminal regulatory region, and MEKK1 has been shown to ubiquitylate the AP-1 (activator protein 1) transcription factor protein c-Jun, but the mechanism by which MEKK1 interacts with c-Jun to induce ubiquitylation has not been defined. Proximal to the RING domain is a SWIM (SWI2/SNF2 and MuDR) domain of undetermined function. In the present study, we demonstrate that the MEKK1 SWIM domain, but not the RING domain, directly associates with the c-Jun DNA-binding domain, and that the SWIM domain is required for MEKK1-dependent c-Jun ubiquitylation. We further show that this MEKK1 SWIM-Jun interaction is specific, as SWIM domains from other proteins failed to bind c-Jun. We reveal that, although the Jun and Fos DNA-binding domains are highly conserved, the MEKK1 SWIM domain does not bind Fos. Finally, we identify the sequence unique to Jun proteins required for specific interaction with the MEKK1 SWIM domain. Therefore we propose that the MEKK1 SWIM domain represents a novel substrate-binding domain necessary for direct interaction between c-Jun and MEKK1 that promotes MEKK1-dependent c-Jun ubiquitylation.

  2. c-fos/c-jun expression and AP-1 activation in skin fibroblasts from centenarians.

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    Grassilli, E; Bellesia, E; Salomoni, P; Croce, M A; Sikora, E; Radziszewska, E; Tesco, G; Vergelli, M; Latorraca, S; Barbieri, D; Fagiolo, U; Santacaterina, S; Amaducci, L; Tiozzo, R; Sorbi, S; Franceschi, C

    1996-09-13

    In vitro replicative senescence is characterized by an irreversible growth arrest due to the inability of the cell to induce some key regulators of cell cycle progression, such as c-fos and AP-1, in response to mitogenic stimuli. In vitro replicative senescence and in vivo aging have been assumed to be two related phenomena, likely controlled by overlapping or interacting genes. As a corollary, fibroblasts from centenarians, which have undergone a long process of senescence in vivo should have very limited proliferative capability. On the contrary, in a previous work we found that fibroblasts from centenarians exhibited the same capacity to respond to different mitogenic stimuli as fibroblasts from young donors. Here we provide evidences that the well preserved proliferative response is likely due to the fact that some pivotal regulators- c-fos, c-jun and AP-1-are still fully inducible, despite a long process of in vivo senescence. Our data therefore suggest that in vivo and in vitro aging are separate phenomena whose possible relationships, if any, have to be ascertained very carefully.

  3. TAK1 Participates in c-Jun N-Terminal Kinase Signaling during Drosophila Development

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    Takatsu, Yoshihiro; Nakamura, Makoto; Stapleton, Mark; Danos, Maria C.; Matsumoto, Kunihiro; O'Connor, Michael B.; Shibuya, Hiroshi; Ueno, Naoto

    2000-01-01

    Transforming growth factor β (TGF-β)-activated kinase 1 (TAK1) is a member of the MAPKKK superfamily and has been characterized as a component of the TGF-β/bone morphogenetic protein signaling pathway. TAK1 function has been extensively studied in cultured cells, but its in vivo function is not fully understood. In this study, we isolated a Drosophila homolog of TAK1 (dTAK1) which contains an extensively conserved NH2-terminal kinase domain and a partially conserved COOH-terminal domain. To learn about possible endogenous roles of TAK1 during animal development, we generated transgenic flies which express dTAK1 or the mouse TAK1 (mTAK1) gene in the fly visual system. Ectopic activation of TAK1 signaling leads to a small eye phenotype, and genetic analysis reveals that this phenotype is a result of ectopically induced apoptosis. Genetic and biochemical analyses also indicate that the c-Jun amino-terminal kinase (JNK) signaling pathway is specifically activated by TAK1 signaling. Expression of a dominant negative form of dTAK during embryonic development resulted in various embryonic cuticle defects including dorsal open phenotypes. Our results strongly suggest that in Drosophila melanogaster, TAK1 functions as a MAPKKK in the JNK signaling pathway and participates in such diverse roles as control of cell shape and regulation of apoptosis. PMID:10757786

  4. c-jun-N-Terminal Kinase (JNK) for the Treatment of Amyotrophic Lateral Sclerosis

    Science.gov (United States)

    2015-03-01

    1 AWARD NUMBER: W81XWH-12-1-0431 TITLE: “c-jun-N-Terminal Kinase (JNK) for the Treatment of Amyotrophic Lateral Sclerosis ” PRINCIPAL...TITLE AND SUBTITLE “c-jun-N-Terminal Kinase (JNK) for the Treatment of Amyotrophic Lateral Scelerosis” 5a. CONTRACT NUMBER 5b. GRANT NUMBER... Lateral   Sclerosis ”   Final  Report:  Project  Period  Sept  2012-­‐Dec  2014     Personnel  List:     Feng,  Yangbo

  5. Recruitment of nuclear factor Y to the inverted CCAAT element (ICE) by c-Jun and E1A stimulates basal transcription of the bone sialoprotein gene in osteosarcoma cells.

    Science.gov (United States)

    Su, Ming; Bansal, Anil K; Mantovani, Roberto; Sodek, Jaro

    2005-11-18

    Bone sialoprotein (BSP), a major protein in the extracellular matrix of bone, is expressed almost exclusively by bone cells and by cancer cells that have a propensity to metastasize to bone. Previous studies have shown that v-src stimulates basal transcription of bsp in osteosarcoma (ROS 17/2.8) cells by targeting the inverted CCAAT element (ICE) in the proximal promoter. To identify possible downstream effectors of Src we studied the effects of the proto-oncogene c-jun, which functions downstream of Src, on basal transcription of bsp using transient transfection assays. Increased expression of endogenous c-Jun induced by the tumor promoter 12-O-tetradecanoyl-phorbol 13-acetate and ectopic expression of c-Jun increased basal transcription of chimeric reporter constructs encompassing the proximal promoter by 1.5-3-fold in ROS 17/2.8 osteosarcoma cells, with more modest effects in a normal bone cell line, RBMC-D8. The effects of c-Jun were abrogated by mutations in the ICE box and by co-expression of dominant negative nuclear factor Y, subunit A (NF-YA). The increase in bsp transcription did not require phosphorylation of c-Jun and was not altered by trichostatin treatment or by ectopic expression of p300/CREB-binding protein (CBP) or mutated forms lacking histone acetyltransferase (HAT) activity. Similarly, ectopic expression of p300/CBP-associated factor (P/CAF), which transduces p300/CBP effects, or of HAT-defective P/CAF did not influence the c-jun effects. Surprisingly, E1A, which competes with P/CAF binding to p300/CBP, also stimulated BSP transcription through NF-Y independently of c-jun, p300/CBP, and P/CAF. Collectively, these studies show that c-Jun and E1A regulate basal transcription of bsp in osteosarcoma cells by recruiting the NF-Y transcriptional complex to the ICE box in a mechanism that is independent of p300/CBP and P/CAF HAT activities.

  6. miR-138 protects cardiomyocytes from hypoxia-induced apoptosis via MLK3/JNK/c-jun pathway

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    He, Siyi; Liu, Peng; Jian, Zhao; Li, Jingwei; Zhu, Yun; Feng, Zezhou; Xiao, Yingbin, E-mail: xiaoyb@vip.sina.com

    2013-11-29

    Highlights: •First time to find miR-138 is up-regulated in hypoxic cardiomyocytes. •First time to find miR-138 targets MLK3 and regulates JNK/c-jun pathway. •Rare myocardial biopsy of patients with CHD were collected. •Both silence and overexpression of miR-138 were implemented. •Various methods were used to detect cell function. -- Abstract: Cardiomyocytes experience a series of complex endogenous regulatory mechanisms against apoptosis induced by chronic hypoxia. MicroRNAs are a class of endogenous small non-coding RNAs that regulate cellular pathophysiological processes. Recently, microRNA-138 (miR-138) has been found related to hypoxia, and beneficial for cell proliferation. Therefore, we intend to study the role of miR-138 in hypoxic cardiomyocytes and the main mechanism. Myocardial samples of patients with congenital heart disease (CHD) were collected to test miR-138 expression. Agomir or antagomir of miR-138 was transfected into H9C2 cells to investigate its effect on cell apoptosis. Higher miR-138 expression was observed in patients with cyanotic CHD, and its expression gradually increased with prolonged hypoxia time in H9C2 cells. Using MTT and LDH assays, cell growth was significantly greater in the agomir group than in the negative control (NC) group, while antagomir decreased cell survival. Dual luciferase reporter gene and Western-blot results confirmed MLK3 was a direct target of miR-138. It was found that miR-138 attenuated hypoxia-induced apoptosis using TUNEL, Hoechst staining and Annexin V-PE/7-AAD flow cytometry analysis. We further detected expression of apoptosis-related proteins. In the agomir group, the level of pro-apoptotic proteins such as cleaved-caspase-3, cleaved-PARP and Bad significantly reduced, while Bcl-2 and Bcl-2/Bax ratio increased. Opposite changes were observed in the antagomir group. Downstream targets of MLK3, JNK and c-jun, were also suppressed by miR-138. Our study demonstrates that up-regulation of miR-138 plays

  7. ERK/c-Jun Recruits Tet1 to Induce Zta Expression and Epstein-Barr Virus Reactivation through DNA Demethylation.

    Science.gov (United States)

    Zhang, Wei; Han, Dongjie; Wan, Pin; Pan, Pan; Cao, Yanhua; Liu, Yingle; Wu, Kailang; Wu, Jianguo

    2016-10-06

    DNA demethylation plays an essential role in the reactivation of Epstein-Barr virus (EBV) from latency infection. However, it is unclear how epigenetic modification is initiated in responding to stimuli. Here, we demonstrate that ERK/c-Jun signaling is involved in DNA demethylation of EBV immediate early (IE) gene Zta in response to 12-O-Tetradecanoylphorbol-13-acetate (TPA) stimulation. Remarkably, Ser73 phosphorylation of c-Jun facilitates Zta promoter demethylation and EBV reactivation, whereas knockdown of c-Jun attenuates Zta demethylation and viral reactivation. More importantly, we reveal for the first time that c-Jun interacts with DNA dioxygenase Tet1 and facilitates Tet1 to bind to Zta promoter. The binding of c-Jun and Tet1 to Zta enhances promoter demethylation, resulting in the activation of Zta, the stimulation of BHRF1 (a lytic early gene) and gp350/220 (a lytic late gene), and ultimately the reactivation of EBV. Knockdown of Tet1 attenuates TPA-induced Zta demethylation and EBV reactivation. Thus, TPA activates ERK/c-Jun signaling, which subsequently facilitates Tet1 to bind to Zta promoter, leading to DNA demethylation, gene expression, and EBV reactivation. This study reveals important roles of ERK/c-Jun signaling and Tet1 dioxygenase in epigenetic modification, and provides new insights into the mechanism underlying the regulation of virus latent and lytic infection.

  8. β-glucan reduces exercise-induced stress through downregulation of c-Fos and c-Jun expression in the brains of exhausted rats.

    Science.gov (United States)

    Hong, Heeok; Kim, Chang-Ju; Kim, Jae-Deung; Seo, Jin-Hee

    2014-05-01

    Immediate-early genes are involved in acute stress responses in the central nervous system. β-glucan stimulates innate immune defenses, exerts an anti-tumor response and increases resistance to a wide variety of types of infection. To date, the effect of β-glucan on the expression of immediate-early genes under stressful conditions has not been elucidated. In the present study, the effects of β-glucan on the expression of the oncogenes c-Fos and c-Jun in the hypothalamus, dentate gyrus and dorsal raphe in rats following exhaustive treadmill running were investigated. Male Sprague Dawley rats were randomly divided into five groups (n=10 in each group) as follows: Control, exercise, exercise and 50 mg/kg β-glucan treatment, exercise and 100 mg/kg β-glucan treatment, and exercise and 200 mg/kg β-glucan treatment. Rats in the β-glucan‑treated groups were administered β-glucan at the respective dose once per day for seven days. Rats in the exercise groups performed treadmill running once per day for six days. On the seventh day of the experiment, the time to exhaustion in response to treadmill running was determined for the exercise groups. The expression of c-Fos and c-Jun in the hypothalamus, dorsal raphe and hippocampus was enhanced by exhaustive treadmill running. Administration of β-glucan resulted in an increase in the time to exhaustion and the suppression of the exercise-induced increment in c-Fos and c-Jun expression. In conclusion, β-glucan may exert an alleviating effect on exercise-induced stress through the suppression of c-Fos and c-Jun expression in the brains of exhausted rats.

  9. Epigenetic control of MHC-II: interplay between CIITA and histone-modifying enzymes.

    Science.gov (United States)

    Zika, Eleni; Ting, Jenny P-Y

    2005-02-01

    Recent advances have shown the crucial role of histone-modifying enzymes in controlling gene activation and repression. This led to the 'histone code' hypothesis, which proposes that combinations of histone modifications work in concert to affect specific gene expression. Mounting evidence suggests that the class II transactivator modulates promoter accessibility by coordinating the recruitment of chromatin modifiers in a time-dependent fashion. MHC-II expression is exquisitely controlled by these highly specific, coordinated and dynamic interactions at the promoter.

  10. [Regulating effect of N-acetyl-seryl-aspartyl-lysyl-proline on activation of c-jun N-terminal kinase pathway in rats with silicosis].

    Science.gov (United States)

    Wei, Zhong-qiu; Yu, Wan-ying; Feng, Hai-li; Ma, Wen-dong; Li, Zhi-guo; Xu, Hong; Wang, Rui-min; Yang, Fang

    2013-05-01

    To investigate the regulatory effect of N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP) on the activation of c-jun N-terminal kinase (JNK) signal transduction pathway and its role in silicotic fibrosis. A rat model of silicosis was developed by intratracheal instillation. Sixty rats were randomly divided into 4-week control group (n = 10), 8-week control group (n = 10), 4-week silicosis model group (n = 10), 8-week silicosis model group (n = 10), AcSDKP treatment group (n = 10), and AcSDKP prevention group (n = 10). The content of hydroxyproline in lung tissue was measured using a p-dimethylaminoben-zaldehyde reagent; the expression levels of transforming growth factor (TGF)-beta 1 (TGF-β1), phospho-JNK, JNK, and c-jun in lung tissue were measured by Western blot. The lung fibroblasts from neonatal rats were cultured, and the 4th generation of cells were used in the experiment; these cells were divided into control group, TGF-β1 stimulation group, SP600125 intervention group, and AcSDKP intervention group. The distributions of phospho-JNK and c-jun in lung fibroblasts were observed by immunocytochemistry; the expression levels of type I collagen and type III collagen in lung fibroblasts were measured by Western blot. The expression levels of TGF-β1, phospho-JNK, and c-jun and the content of hydroxyproline in the AcSDKP treatment group were 70.60%, 78.03%, 79.85%, and 71.28%, respectively, of those in the 4-week silicosis model group (P silicosis model group (P silicosis model group (P < 0.05). The expression levels of phospho-JNK and c-jun in the AcSDKP intervention group were 54.59% and 55.56%, respectively, of those in the TGF-β1 stimulation group; the expression levels of type I collagen and type III collagen in the AcSDKP intervention group were 79.9% and 84.4%, respectively, of those in the TGF-β1 stimulation group (P < 0.05). AcSDKP exerts anti-silicotic fibrosis effect probably by inhibiting the activation of JNK signal transduction pathway mediated by

  11. MAGE-A1 promotes melanoma proliferation and migration through C-JUN activation

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    Wang, Dong [Department of Dermatology, General Hospital of People' s Liberation Army, Beijing 100853 (China); The 309th Hospital of China People' s Liberation Army, Beijing 100091 (China); Wang, Junyun; Ding, Nan [CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Li, Yongjun; Yang, Yaran [CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101 (China); Fang, Xiangdong, E-mail: fangxd@big.ac.cn [CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101 (China); Zhao, Hua, E-mail: luckhua301@163.com [Department of Dermatology, General Hospital of People' s Liberation Army, Beijing 100853 (China)

    2016-05-13

    MAGE-A1 belongs to the chromosome X-clustered genes of cancer-testis antigen family and is normally expressed in the human germ line but is also overexpressed in various tumors. Previous studies of MAGE-A1 in melanoma mainly focused on methylation changes or its role in immunotherapy, however, its biological functions in melanoma have remained unknown. In order to determine the role of MAGE-A1 in melanoma growth and metastasis, we manipulated melanoma cell lines with overexpression and knockdown of MAGE-A1. Integration of cell proliferation assays, transwell migration and invasion assays, and RNA-Seq analysis revealed that up-regulation of MAGE-A1 dramatically promoted proliferation, migration, and invasion of human melanoma cell lines in vitro, while down-regulation of MAGE-A1 inhibited those characteristics associated with tumor cells. Furthermore, transcriptome sequencing revealed that MAGE-A1 exerts its tumor promoting activity by activating p-C-JUN directly or through ERK-MAPK signaling pathways. Based on our findings, we propose that MAGE-A1 may be a potential therapeutic target for melanoma patients. - Highlights: • MAGE-A1 promotes proliferation and clone formation in melanoma cell lines. • MAGE-A1 enhances tumor cell migration and invasion in melanoma cell lines. • Network including C-JUN, IL8, and ARHGAP29 play critical role in malignant melanoma. • Oncogenic MAGE-A1 increases p-C-JUN levels, possibly via ERK-MAPK signaling pathway.

  12. Anti-proliferative activities of finasteride in benign prostate epithelial cells require stromal fibroblasts and c-Jun gene.

    Directory of Open Access Journals (Sweden)

    Kai Wang

    Full Text Available This study aimed to identify the role of mouse fibroblast-mediated c-Jun and IGF-1 signaling in the therapeutic effect of finasteride on benign prostatic epithelial cells. BPH-1 cells, alone or with fibroblasts (c-Jun+/+ or c-Jun-/-, were implanted subcutaneously in male nude mice who were then treated with finasteride. The degrees of cell proliferation, apoptosis, and sizes of the xenografts were determined. BPH-1 cells were grown alone or co-cultured with mouse fibroblasts in the presence of finasteride and the level of IGF-1 secreted into the medium by the fibroblasts was determined. The proliferation-associated signaling pathway in BPH-1 cells was also evaluated. Fibroblasts and c-Jun promoted xenograft growth, stimulated Ki-67 expression, and inhibited BPH-1 apoptosis. Finasteride did not induce the shrinkage of xenografts in the combined-grafted groups despite repressing Ki-67 expression and inducing cell apoptosis. The addition of c-Jun-/- fibroblasts did not promote xenograft growth. In the absence of c-Jun and fibroblasts, finasteride did not alter xenograft growth, Ki-67 expression, or cell apoptosis. The in vitro results demonstrated that when BPH-1 cells were grown in monoculture, treatment with finasteride did not induce cell death and stimulated the expression of pro-proliferative signaling molecules, while in the presence of fibroblasts containing c-Jun, finasteride treatment repressed epithelial cell proliferation, the level of IGF-1 in the medium, and the activation of downstream pro-proliferative signaling pathways. Taken together, our results suggest that fibroblasts, c-Jun, and IGF-1 play key roles in mediating stromal-epithelial interactions that are required for the therapeutic effects of finasteride in benign prostate epithelial cells.

  13. Anti-proliferative activities of finasteride in benign prostate epithelial cells require stromal fibroblasts and c-Jun gene.

    Science.gov (United States)

    Wang, Kai; Jin, Song; Fan, Dongdong; Wang, Mingshuai; Xing, Nianzeng; Niu, Yinong

    2017-01-01

    This study aimed to identify the role of mouse fibroblast-mediated c-Jun and IGF-1 signaling in the therapeutic effect of finasteride on benign prostatic epithelial cells. BPH-1 cells, alone or with fibroblasts (c-Jun+/+ or c-Jun-/-), were implanted subcutaneously in male nude mice who were then treated with finasteride. The degrees of cell proliferation, apoptosis, and sizes of the xenografts were determined. BPH-1 cells were grown alone or co-cultured with mouse fibroblasts in the presence of finasteride and the level of IGF-1 secreted into the medium by the fibroblasts was determined. The proliferation-associated signaling pathway in BPH-1 cells was also evaluated. Fibroblasts and c-Jun promoted xenograft growth, stimulated Ki-67 expression, and inhibited BPH-1 apoptosis. Finasteride did not induce the shrinkage of xenografts in the combined-grafted groups despite repressing Ki-67 expression and inducing cell apoptosis. The addition of c-Jun-/- fibroblasts did not promote xenograft growth. In the absence of c-Jun and fibroblasts, finasteride did not alter xenograft growth, Ki-67 expression, or cell apoptosis. The in vitro results demonstrated that when BPH-1 cells were grown in monoculture, treatment with finasteride did not induce cell death and stimulated the expression of pro-proliferative signaling molecules, while in the presence of fibroblasts containing c-Jun, finasteride treatment repressed epithelial cell proliferation, the level of IGF-1 in the medium, and the activation of downstream pro-proliferative signaling pathways. Taken together, our results suggest that fibroblasts, c-Jun, and IGF-1 play key roles in mediating stromal-epithelial interactions that are required for the therapeutic effects of finasteride in benign prostate epithelial cells.

  14. Correlation between spina bifida manifesta in fetal rats and c-Jun N-terminal kinase signaling★

    Science.gov (United States)

    Ma, Yinghuan; Bao, Yongxin; Li, Chenghao; Jiao, Fubin; Xin, Hongjie; Yuan, Zhengwei

    2012-01-01

    Fetal rat models with neural tube defects were established by injection with retinoic acid at 10 days after conception. The immunofluorescence assay and western blot analysis showed that the number of caspase-3 positive cells in myeloid tissues for spina bifida manifesta was increased. There was also increased phosphorylation of c-Jun N-terminal kinase, a member of the mitogen activated protein kinase family. The c-Jun N-terminal kinase phosphorylation level was positively correlated with caspase-3 expression in myeloid tissues for spina bifida manifesta. Experimental findings indicate that abnormal apoptosis is involved in retinoic acid-induced dominant spina bifida formation in fetal rats, and may be associated with the c-Jun N-terminal kinase signal transduction pathway. PMID:25337099

  15. Cigarette smoke inhibits LPS-induced FABP5 expression by preventing c-Jun binding to the FABP5 promoter.

    Science.gov (United States)

    Rao, Deviyani; Perraud, Anne-Laure; Schmitz, Carsten; Gally, Fabienne

    2017-01-01

    Cigarette smoking is the primary cause of chronic obstructive pulmonary disease (COPD) with repeated and sustained infections linked to disease pathogenesis and exacerbations. The airway epithelium constitutes the first line of host defense against infection and is known to be impaired in COPD. We have previously identified Fatty Acid Binding Protein 5 (FABP5) as an important anti-inflammatory player during respiratory infections and showed that overexpression of FABP5 in primary airway epithelial cells protects against bacterial infection and inflammation. While cigarette smoke down regulates FABP5 expression, its mechanism remains unknown. In this report, we have identified three putative c-Jun binding sites on the FABP5 promoter and show that cigarette smoke inhibits the binding of c-Jun to its consensus sequence and prevents LPS-induced FABP5 expression. Using chromatin immunoprecipitation, we have determined that c-Jun binds the FABP5 promoter when stimulated with LPS but the presence of cigarette smoke greatly reduces this binding. Furthermore, cigarette smoke or a mutation in the c-Jun binding site inhibits LPS-induced FABP5 promoter activity. These data demonstrate that cigarette smoke interferes with FABP5 expression in response to bacterial infection. Thus, functional activation of FABP5 may be a new therapeutic strategy when treating COPD patients suffering from exacerbations.

  16. Palbociclib inhibits epithelial-mesenchymal transition and metastasis in breast cancer via c-Jun/COX-2 signaling pathway.

    Science.gov (United States)

    Qin, Ge; Xu, Fei; Qin, Tao; Zheng, Qiufan; Shi, Dingbo; Xia, Wen; Tian, Yun; Tang, Yanlai; Wang, Jingshu; Xiao, Xiangshen; Deng, Wuguo; Wang, Shusen

    2015-12-08

    Palbociclib, a highly selective CDK4/6 inhibitor, has been shown to be a novel anti-tumor agent that suppresses breast cancer cell proliferation. However, its anti-metastasis activity remains controversial. In the present study, we evaluated whether palbociclib prevented breast cancer cell metastasis and revealed its regulatory mechanism. We found that palbociclib inhibited migration and invasion in the breast cancer cells MDA-MB-231 and T47D. The epithelial-mesenchymal transition (EMT) markers, vimentin and Snail, were down-regulated with palbociclib treatment. Moreover, we revealed that this inhibition was mediated by the c-Jun/COX-2 pathway. COX-2 was decreased after palbociclib treatment. The production of PGE2 was also reduced along with COX-2. Additionally, our data showed that c-Jun, a crucial transcriptional regulator of COX-2, was down-regulated by palbociclib. We found that palbociclib weakened the COX-2 promoter binding activity of c-Jun and prevented its translocation from the cytoplasm to cell nuclei. Bioluminescence imaging and tail intravenous injection were used to evaluate the anti-metastasis effect of palbociclib in vivo. The data demonstrated that palbociclib reduced breast cancer metastasis to the lung. These results therefore demonstrated that the anti-metastasis activity of palbociclib is mediated via the c-Jun/COX-2 signaling pathway by inhibiting EMT in breast cancer cells.

  17. c-Jun DNAzymes inhibit myocardial inflammation, ROS generation, infarct size, and improve cardiac function after ischemia-reperfusion injury.

    Science.gov (United States)

    Luo, Xiao; Cai, Hong; Ni, Jun; Bhindi, Ravinay; Lowe, Harry C; Chesterman, Colin N; Khachigian, Levon M

    2009-11-01

    Coronary reperfusion has been the mainstay therapy for reduced infarct size after a heart attack. However, this intervention also results in myocardial injury by initiating a marked inflammatory reaction, and new treatments are keenly sought. The basic-region leucine zipper protein, c-Jun is poorly expressed in the normal myocardium and is induced within 24 hours after myocardial ischemia-reperfusion injury. Synthetic catalytic DNA molecules (DNAzymes) targeting c-Jun (Dz13) reduce infarct size in the area-at-risk (AAR) regardless of whether it is delivered intramyocardially at the initiation of ischemia or at the time of reperfusion. Dz13 attenuates neutrophil infiltration, c-Jun and ICAM-1 expression in vascular endothelium, cardiomyocyte apoptosis, and the generation of reactive oxygen species in the reperfused myocardium. It inhibits infiltration into the AAR of complement 3 (C3), C3a receptor (C3aR), membrane attack complex-1 (Mac-1), or matrix metalloproteinase-2 (MMP-2) positive inflammatory cells. Dz13 also improves cardiac function without influencing myocardial vascularity or fibrosis. These findings demonstrate the regulatory role of c-Jun in the pathogenesis of myocardial inflammation and infarction following ischemia-reperfusion injury, and inhibition of this process using catalytic DNA.

  18. c-Jun N-Terminal Kinases (JNKs) Are Critical Mediators of Osteoblast Activity In Vivo.

    Science.gov (United States)

    Xu, Ren; Zhang, Chao; Shin, Dong Yeon; Kim, Jung-Min; Lalani, Sarfaraz; Li, Na; Yang, Yeon-Suk; Liu, Yifang; Eiseman, Mark; Davis, Roger J; Shim, Jae-Hyuck; Greenblatt, Matthew B

    2017-09-01

    The c-Jun N-terminal kinases (JNKs) are ancient and evolutionarily conserved regulators of proliferation, differentiation, and cell death responses. Currently, in vitro studies offer conflicting data about whether the JNK pathway augments or represses osteoblast differentiation, and the contribution of the JNK pathway to regulation of bone mass in vivo remains unclear. Here we show that Jnk1-/- mice display severe osteopenia due to impaired bone formation, whereas Jnk2-/- mice display a mild osteopenia only evident in long bones. In order to both confirm that these effects were osteoblast intrinsic and assess whether redundancy with JNK1 masks a potential contribution of JNK2, mice with a conditional deletion of both JNK1 and JNK2 floxed conditional alleles in osteoblasts (Jnk1-2osx ) were bred. These mice displayed a similar degree of osteopenia to Jnk1-/- mice due to decreased bone formation. In vitro, Jnk1-/- osteoblasts display a selective defect in the late stages of osteoblast differentiation with impaired mineralization activity. Downstream of JNK1, phosphorylation of JUN is impaired in Jnk1-/- osteoblasts. Transcriptome analysis showed that JNK1 is required for upregulation of several osteoblast-derived proangiogenic factors such as IGF2 and VEGFa. Accordingly, JNK1 deletion results in a significant reduction skeletal vasculature in mice. Taken together, this study establishes that JNK1 is a key mediator of osteoblast function in vivo and in vitro. © 2017 American Society for Bone and Mineral Research. © 2017 American Society for Bone and Mineral Research.

  19. Evolutionary conserved role of c-Jun-N-terminal kinase in CO2-induced epithelial dysfunction.

    Directory of Open Access Journals (Sweden)

    István Vadász

    Full Text Available Elevated CO(2 levels (hypercapnia occur in patients with respiratory diseases and impair alveolar epithelial integrity, in part, by inhibiting Na,K-ATPase function. Here, we examined the role of c-Jun N-terminal kinase (JNK in CO(2 signaling in mammalian alveolar epithelial cells as well as in diptera, nematodes and rodent lungs. In alveolar epithelial cells, elevated CO(2 levels rapidly induced activation of JNK leading to downregulation of Na,K-ATPase and alveolar epithelial dysfunction. Hypercapnia-induced activation of JNK required AMP-activated protein kinase (AMPK and protein kinase C-ζ leading to subsequent phosphorylation of JNK at Ser-129. Importantly, elevated CO(2 levels also caused a rapid and prominent activation of JNK in Drosophila S2 cells and in C. elegans. Paralleling the results with mammalian epithelial cells, RNAi against Drosophila JNK fully prevented CO(2-induced downregulation of Na,K-ATPase in Drosophila S2 cells. The importance and specificity of JNK CO(2 signaling was additionally demonstrated by the ability of mutations in the C. elegans JNK homologs, jnk-1 and kgb-2 to partially rescue the hypercapnia-induced fertility defects but not the pharyngeal pumping defects. Together, these data provide evidence that deleterious effects of hypercapnia are mediated by JNK which plays an evolutionary conserved, specific role in CO(2 signaling in mammals, diptera and nematodes.

  20. Involvement of c-Jun N-Terminal Kinase in TNF-α-Driven Remodeling.

    Science.gov (United States)

    Eurlings, Irene M J; Reynaert, Niki L; van de Wetering, Cheryl; Aesif, Scott W; Mercken, Evi M; de Cabo, Rafael; van der Velden, Jos L; Janssen-Heininger, Yvonne M; Wouters, Emiel F M; Dentener, Mieke A

    2017-03-01

    Lung tissue remodeling in chronic obstructive pulmonary disease (COPD) is characterized by airway wall thickening and/or emphysema. Although the bronchial and alveolar compartments are functionally independent entities, we recently showed comparable alterations in matrix composition comprised of decreased elastin content and increased collagen and hyaluronan contents of alveolar and small airway walls. Out of several animal models tested, surfactant protein C (SPC)-TNF-α mice showed remodeling in alveolar and airway walls similar to what we observed in patients with COPD. Epithelial cells are able to undergo a phenotypic shift, gaining mesenchymal properties, a process in which c-Jun N-terminal kinase (JNK) signaling is involved. Therefore, we hypothesized that TNF-α induces JNK-dependent epithelial plasticity, which contributes to lung matrix remodeling. To this end, the ability of TNF-α to induce a phenotypic shift was assessed in A549, BEAS2B, and primary bronchial epithelial cells, and phenotypic markers were studied in SPC-TNF-α mice. Phenotypic markers of mesenchymal cells were elevated both in vitro and in vivo, as shown by the expression of vimentin, plasminogen activator inhibitor-1, collagen, and matrix metalloproteinases. Concurrently, the expression of the epithelial markers, E-cadherin and keratin 7 and 18, was attenuated. A pharmacological inhibitor of JNK attenuated this phenotypic shift in vitro, demonstrating involvement of JNK signaling in this process. Interestingly, activation of JNK signaling was also clearly present in lungs of SPC-TNF-α mice and patients with COPD. Together, these data show a role for TNF-α in the induction of a phenotypic shift in vitro, resulting in increased collagen production and the expression of elastin-degrading matrix metalloproteinases, and provide evidence for involvement of the TNF-α-JNK axis in extracellular matrix remodeling.

  1. Charge State of the Globular Histone Core Controls Stability of the Nucleosome

    Science.gov (United States)

    Fenley, Andrew T.; Adams, David A.; Onufriev, Alexey V.

    2010-01-01

    Presented here is a quantitative model of the wrapping and unwrapping of the DNA around the histone core of the nucleosome that suggests a mechanism by which this transition can be controlled: alteration of the charge state of the globular histone core. The mechanism is relevant to several classes of posttranslational modifications such as histone acetylation and phosphorylation; several specific scenarios consistent with recent in vivo experiments are considered. The model integrates a description based on an idealized geometry with one based on the atomistic structure of the nucleosome, and the model consistently accounts for both the electrostatic and nonelectrostatic contributions to the nucleosome free energy. Under physiological conditions, isolated nucleosomes are predicted to be very stable (38 ± 7 kcal/mol). However, a decrease in the charge of the globular histone core by one unit charge, for example due to acetylation of a single lysine residue, can lead to a significant decrease in the strength of association with its DNA. In contrast to the globular histone core, comparable changes in the charge state of the histone tail regions have relatively little effect on the nucleosome's stability. The combination of high stability and sensitivity explains how the nucleosome is able to satisfy the seemingly contradictory requirements for thermodynamic stability while allowing quick access to its DNA informational content when needed by specific cellular processes such as transcription. PMID:20816070

  2. Control of B Cell Development by the Histone H2A Deubiquitinase MYSM1

    Science.gov (United States)

    Jiang, Xiao-Xia; Nguyen, Quan; Chou, YuChia; Wang, Tao; Nandakumar, Vijayalakshmi; Yates, Peter; Jones, Lindsey; Wang, Lifeng; Won, Hae-Jung; Lee, Hye-Ra; Jung, Jae U; Muschen, Markus; Huang, Xue F; Chen, Si-Yi

    2013-01-01

    Epigenetic histone modifications play critical roles in the control of gene transcription. Recently, an increasing number of histone H2A deubiquitinases have been identified and characterized. However, the physiological functions for this entire group of histone H2A deubiquitinases remain unknown. In this study, we revealed that the histone H2A deubiquitinase MYSM1 plays an essential and intrinsic role in early B-cell development. MYSM1 deficiency results in a block in early B-cell commitment and a defect of B-cell progenitors in expression of EBF1 and other B-lymphoid genes. We further demonstrated that MYSM1 de-represses EBF1 transcription in B-cell progenitors by orchestrating histone modifications and transcription factor recruitment to the EBF1 locus. Thus, this study not only uncovers the essential role for MYSM1 in gene transcription during early B cell development, but also underscores the biological significance of reversible epigenetic histone H2A ubiquitination. PMID:22169041

  3. Effect of growth hormone and serum on the expression of the proto-oncogenes c-jun and c-fos in insulin producing cells

    DEFF Research Database (Denmark)

    Petersen, Elisabeth D.; Billestrup, N; Nielsen, Jens Høiriis

    1990-01-01

    Expression of the proto-oncogenes c-fos and c-jun was analysed in the insulin producing rat tumor cell line, RIN 5AH. Addition of fetal calf serum (FCS) to serum-starved cells in the presence of cycloheximid induced a modest increase in c-fos and c-jun mRNA levels, whereas growth hormone (GH...

  4. A feed-forward regulation of endothelin receptors by c-Jun in human non-pigmented ciliary epithelial cells and retinal ganglion cells.

    Science.gov (United States)

    Wang, Junming; Ma, Hai-Ying; Krishnamoorthy, Raghu R; Yorio, Thomas; He, Shaoqing

    2017-01-01

    c-Jun, c-Jun N-terminal kinase(JNK) and endothelin B (ETB) receptor have been shown to contribute to the pathogenesis of glaucoma. Previously, we reported that an increase of c-Jun and CCAAT/enhancer binding protein β (C/EBPβ) immunohistostaining is associated with upregulation of the ETB receptor within the ganglion cell layer of rats with elevated intraocular pressure (IOP). In addition, both transcription factors regulate the expression of the ETB receptor in human non-pigmented ciliary epithelial cells (HNPE). The current study addressed the mechanisms by which ET-1 produced upregulation of ET receptors in primary rat retinal ganglion cells (RGCs) and HNPE cells. Treatment of ET-1 and ET-3 increased the immunocytochemical staining of c-Jun and C/EBPβ in primary rat RGCs and co-localization of both transcription factors was observed. A marked increase in DNA binding activity of AP-1 and C/EBPβ as well as elevated protein levels of c-Jun and c-Jun-N-terminal kinase (JNK) were detected following ET-1 treatment in HNPE cells. Overexpression of ETA or ETB receptor promoted the upregulation of c-Jun and also elevated its promoter activity. In addition, upregulation of C/EBPβ augmented DNA binding and mRNA expression of c-Jun, and furthermore, the interaction of c-Jun and C/EBPβ was confirmed using co-immunoprecipitation. Apoptosis of HNPE cells was identified following ET-1 treatment, and overexpression of the ETA or ETB receptor produced enhanced apoptosis. ET-1 mediated upregulation of c-Jun and C/EBPβ and their interaction may represent a novel mechanism contributing to the regulation of endothelin receptor expression. Reciprocally, c-Jun was also found to regulate the ET receptors and C/EBPβ appeared to play a regulatory role in promoting expression of c-Jun. Taken together, the data suggests that ET-1 triggers the upregulation of c-Jun through both ETA and ETB receptors, and conversely c-Jun also upregulates endothelin receptor expression, thereby

  5. A feed-forward regulation of endothelin receptors by c-Jun in human non-pigmented ciliary epithelial cells and retinal ganglion cells.

    Directory of Open Access Journals (Sweden)

    Junming Wang

    Full Text Available c-Jun, c-Jun N-terminal kinase(JNK and endothelin B (ETB receptor have been shown to contribute to the pathogenesis of glaucoma. Previously, we reported that an increase of c-Jun and CCAAT/enhancer binding protein β (C/EBPβ immunohistostaining is associated with upregulation of the ETB receptor within the ganglion cell layer of rats with elevated intraocular pressure (IOP. In addition, both transcription factors regulate the expression of the ETB receptor in human non-pigmented ciliary epithelial cells (HNPE. The current study addressed the mechanisms by which ET-1 produced upregulation of ET receptors in primary rat retinal ganglion cells (RGCs and HNPE cells. Treatment of ET-1 and ET-3 increased the immunocytochemical staining of c-Jun and C/EBPβ in primary rat RGCs and co-localization of both transcription factors was observed. A marked increase in DNA binding activity of AP-1 and C/EBPβ as well as elevated protein levels of c-Jun and c-Jun-N-terminal kinase (JNK were detected following ET-1 treatment in HNPE cells. Overexpression of ETA or ETB receptor promoted the upregulation of c-Jun and also elevated its promoter activity. In addition, upregulation of C/EBPβ augmented DNA binding and mRNA expression of c-Jun, and furthermore, the interaction of c-Jun and C/EBPβ was confirmed using co-immunoprecipitation. Apoptosis of HNPE cells was identified following ET-1 treatment, and overexpression of the ETA or ETB receptor produced enhanced apoptosis. ET-1 mediated upregulation of c-Jun and C/EBPβ and their interaction may represent a novel mechanism contributing to the regulation of endothelin receptor expression. Reciprocally, c-Jun was also found to regulate the ET receptors and C/EBPβ appeared to play a regulatory role in promoting expression of c-Jun. Taken together, the data suggests that ET-1 triggers the upregulation of c-Jun through both ETA and ETB receptors, and conversely c-Jun also upregulates endothelin receptor expression

  6. Hypertonic stress induces c-fos but not c-jun expression in the human embryonal EUE epithelial cell line.

    Science.gov (United States)

    Rossi, D; Fuhrman Conti, A M; De Grada, L; Larizza, L

    1995-12-01

    Recent evidence has indicated a role for the two early response genes c-fos and c-jun in transcriptional regulation of genes acting in osmoregulation. On this basis we investigated their expression in response to hypertonic stress in the human embryonal EUE epithelial cell line. EUE cells have proven to be a useful tool for studying long-term in vitro adaptation to hypertonic stress. After culturing EUE cells in hypertonic medium a marked c-fos induction was observed, both at the mRNA and the protein level. Northern analysis of fos-mRNA showed a peak expression at 4 h, followed by a progressive decline till complete extinction at 8 h. Immunofluorescence analysis of FOS protein evidenced a similar, although slightly delayed kinetics of expression. Conversely, neither c-jun nor c-myc up-regulation could be detected. The treatment of EUE cells with cycloheximide led to superinduction of c-fos expression, (with high levels up to 12 h), and to a c-jun expression that was just detectable. Hypertonic stimulation of the transformed cell lines A549, MCF7 and JR induced both c-fos and c-jun only in JR cells. Hypertonic shock was also effective in inducing c-fos expression in fetal human diploid fibroblasts, although the response was earlier and more transient than in EUE cells. These findings indicate that c-fos is a primary response gene in hypertonic stress-activated cells, although the pattern and kinetics of its induction may differ according to the type of cell.

  7. c-Jun interacts with the corepressor TG-interacting factor (TGIF) to suppress Smad2 transcriptional activity

    Science.gov (United States)

    Pessah, Marcia; Prunier, Céline; Marais, Jacqueline; Ferrand, Nathalie; Mazars, Anne; Lallemand, François; Gauthier, Jean-Michel; Atfi, Azeddine

    2001-01-01

    The Sma and Mad related (Smad) family proteins are critical mediators of the transforming growth factor-β (TGF-β) superfamily signaling. After TGF-β-mediated phosphorylation and association with Smad4, Smad2 moves to the nucleus and activates expression of specific genes through cooperative interactions with DNA-binding proteins, including members of the winged-helix family of transcription factors, forkhead activin signal transducer (FAST)-1 and FAST2. TGF-β has also been described to activate other signaling pathways, such as the c-Jun N-terminal Kinase (JNK) pathway. Here, we show that activation of JNK cascade blocked the ability of Smad2 to mediate TGF-β-dependent activation of the FAST proteins. This inhibitory activity is mediated through the transcriptional factor c-Jun, which enhances the association of Smad2 with the nuclear transcriptional corepressor TG-interacting factor (TGIF), thereby interfering with the assembly of Smad2 and the coactivator p300 in response to TGF-β signaling. Interestingly, c-Jun directly binds to the nuclear transcriptional corepressor TGIF and is required for TGIF-mediated repression of Smad2 transcriptional activity. These studies thus reveal a mechanism for suppression of Smad2 signaling pathway by JNK cascade through transcriptional repression. PMID:11371641

  8. Activation of the c-Jun N-terminal kinase pathway aggravates proteotoxicity of hepatic mutant Z alpha1-antitrypsin.

    Science.gov (United States)

    Pastore, Nunzia; Attanasio, Sergio; Granese, Barbara; Castello, Raffaele; Teckman, Jeffrey; Wilson, Andrew A; Ballabio, Andrea; Brunetti-Pierri, Nicola

    2017-06-01

    Alpha1-antitrypsin deficiency is a genetic disease that can affect both the lung and the liver. The vast majority of patients harbor a mutation in the serine protease inhibitor 1A (SERPINA1) gene leading to a single amino acid substitution that results in an unfolded protein that is prone to polymerization. Alpha1-antitrypsin defciency-related liver disease is therefore caused by a gain-of-function mechanism due to accumulation of the mutant Z alpha1-antitrypsin (ATZ) and is a key example of an disease mechanism induced by protein toxicity. Intracellular retention of ATZ triggers a complex injury cascade including apoptosis and other mechanisms, although several aspects of the disease pathogenesis are still unclear. We show that ATZ induces activation of c-Jun N-terminal kinase (JNK) and c-Jun and that genetic ablation of JNK1 or JNK2 decreased ATZ levels in vivo by reducing c-Jun-mediated SERPINA1 gene expression. JNK activation was confirmed in livers of patients homozygous for the Z allele, with severe liver disease requiring hepatic transplantation. Treatment of patient-derived induced pluripotent stem cell-hepatic cells with a JNK inhibitor reduced accumulation of ATZ. These data reveal that JNK is a key pathway in the disease pathogenesis and add new therapeutic entry points for liver disease caused by ATZ. (Hepatology 2017;65:1865-1874). © 2017 The Authors. Hepatology published by Wiley Periodicals, Inc., on behalf of the American Association for the Study of Liver Diseases.

  9. Light-Controlled Histone Deacetylase (HDAC) Inhibitors: Towards Photopharmacological Chemotherapy.

    Science.gov (United States)

    Szymanski, Wiktor; Ourailidou, Maria E; Velema, Willem A; Dekker, Frank J; Feringa, Ben L

    2015-11-09

    Cancer treatment suffers from limitations that have a major impact on the patient's quality of life and survival. In the case of chemotherapy, the systemic distribution of cytotoxic drugs reduces their efficacy and causes severe side effects due to nonselective toxicity. Photopharmacology allows a novel approach to address these problems because it employs external, local activation of chemotherapeutic agents by using light. The development of photoswitchable histone deacetylase (HDAC) inhibitors as potential antitumor agents is reported herein. Analogues of the clinically used chemotherapeutic agents vorinostat, panobinostat, and belinostat were designed with a photoswitchable azobenzene moiety incorporated into their structure. The most promising compound exhibits high inhibitory potency in the thermodynamically less stable cis form and a significantly lower activity for the trans form, both in terms of HDAC activity and proliferation of HeLa cells. This approach offers a clear prospect towards local photoactivation of HDAC inhibition to avoid severe side effects in chemotherapy. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Nintedanib modulates surfactant protein-D expression in A549 human lung epithelial cells via the c-Jun N-terminal kinase-activator protein-1 pathway.

    Science.gov (United States)

    Kamio, Koichiro; Usuki, Jiro; Azuma, Arata; Matsuda, Kuniko; Ishii, Takeo; Inomata, Minoru; Hayashi, Hiroki; Kokuho, Nariaki; Fujita, Kazue; Saito, Yoshinobu; Miya, Toshimichi; Gemma, Akihiko

    2015-06-01

    Idiopathic pulmonary fibrosis (IPF) is a progressive disease with a high mortality rate. Signalling pathways activated by several tyrosine kinase receptors are known to be involved in lung fibrosis, and this knowledge has led to the development of the triple tyrosine kinase inhibitor nintedanib, an inhibitor of vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR), and fibroblast growth factor receptor (FGFR), for the treatment of IPF. Pulmonary surfactant protein D (SP-D), an important biomarker of IPF, reportedly attenuates bleomycin-induced pulmonary fibrosis in mice. In this study, we investigated whether nintedanib modulates SP-D expression in human lung epithelial (A549) cells using quantitative real-time reverse transcriptase polymerase chain reaction and western blotting. To investigate the mechanisms underlying the effects of nintedanib, we evaluated the phosphorylation of c-Jun N-terminal kinase (JNK) and its downstream target c-Jun. The effect of the JNK inhibitor SP600125 on c-Jun phosphorylation was also tested. Activation of activator protein-1 (AP-1) was examined using an enzyme-linked immunosorbent assay-based test, and cell proliferation assays were performed to estimate the effect of nintedanib on cell proliferation. Furthermore, we treated mice with nintedanib to examine its in vivo effect on SP-D levels in lungs. These experiments showed that nintedanib up-regulated SP-D messenger RNA expression in a dose-dependent manner at concentrations up to 5 μM, with significant SP-D induction observed at concentrations of 3 μM and 5 μM, in comparison with that observed in vehicle controls. Nintedanib stimulated a rapid increase in phosphorylated JNK in A549 cells within 30 min of treatment and stimulated c-Jun phosphorylation, which was inhibited by the JNK inhibitor SP600125. Additionally, nintedanib was found to activate AP-1. A549 cell proliferation was not affected by nintedanib at any of the tested

  11. The sequence-specific transcription factor c-Jun targets Cockayne syndrome protein B to regulate transcription and chromatin structure.

    Science.gov (United States)

    Lake, Robert J; Boetefuer, Erica L; Tsai, Pei-Fang; Jeong, Jieun; Choi, Inchan; Won, Kyoung-Jae; Fan, Hua-Ying

    2014-04-01

    Cockayne syndrome is an inherited premature aging disease associated with numerous developmental and neurological defects, and mutations in the gene encoding the CSB protein account for the majority of Cockayne syndrome cases. Accumulating evidence suggests that CSB functions in transcription regulation, in addition to its roles in DNA repair, and those defects in this transcriptional activity might contribute to the clinical features of Cockayne syndrome. Transcription profiling studies have so far uncovered CSB-dependent effects on gene expression; however, the direct targets of CSB's transcriptional activity remain largely unknown. In this paper, we report the first comprehensive analysis of CSB genomic occupancy during replicative cell growth. We found that CSB occupancy sites display a high correlation to regions with epigenetic features of promoters and enhancers. Furthermore, we found that CSB occupancy is enriched at sites containing the TPA-response element. Consistent with this binding site preference, we show that CSB and the transcription factor c-Jun can be found in the same protein-DNA complex, suggesting that c-Jun can target CSB to specific genomic regions. In support of this notion, we observed decreased CSB occupancy of TPA-response elements when c-Jun levels were diminished. By modulating CSB abundance, we found that CSB can influence the expression of nearby genes and impact nucleosome positioning in the vicinity of its binding site. These results indicate that CSB can be targeted to specific genomic loci by sequence-specific transcription factors to regulate transcription and local chromatin structure. Additionally, comparison of CSB occupancy sites with the MSigDB Pathways database suggests that CSB might function in peroxisome proliferation, EGF receptor transactivation, G protein signaling and NF-κB activation, shedding new light on the possible causes and mechanisms of Cockayne syndrome.

  12. The sequence-specific transcription factor c-Jun targets Cockayne syndrome protein B to regulate transcription and chromatin structure.

    Directory of Open Access Journals (Sweden)

    Robert J Lake

    2014-04-01

    Full Text Available Cockayne syndrome is an inherited premature aging disease associated with numerous developmental and neurological defects, and mutations in the gene encoding the CSB protein account for the majority of Cockayne syndrome cases. Accumulating evidence suggests that CSB functions in transcription regulation, in addition to its roles in DNA repair, and those defects in this transcriptional activity might contribute to the clinical features of Cockayne syndrome. Transcription profiling studies have so far uncovered CSB-dependent effects on gene expression; however, the direct targets of CSB's transcriptional activity remain largely unknown. In this paper, we report the first comprehensive analysis of CSB genomic occupancy during replicative cell growth. We found that CSB occupancy sites display a high correlation to regions with epigenetic features of promoters and enhancers. Furthermore, we found that CSB occupancy is enriched at sites containing the TPA-response element. Consistent with this binding site preference, we show that CSB and the transcription factor c-Jun can be found in the same protein-DNA complex, suggesting that c-Jun can target CSB to specific genomic regions. In support of this notion, we observed decreased CSB occupancy of TPA-response elements when c-Jun levels were diminished. By modulating CSB abundance, we found that CSB can influence the expression of nearby genes and impact nucleosome positioning in the vicinity of its binding site. These results indicate that CSB can be targeted to specific genomic loci by sequence-specific transcription factors to regulate transcription and local chromatin structure. Additionally, comparison of CSB occupancy sites with the MSigDB Pathways database suggests that CSB might function in peroxisome proliferation, EGF receptor transactivation, G protein signaling and NF-κB activation, shedding new light on the possible causes and mechanisms of Cockayne syndrome.

  13. Melatonin promotes sorafenib-induced apoptosis through synergistic activation of JNK/c-jun pathway in human hepatocellular carcinoma.

    Science.gov (United States)

    Lin, Shibo; Hoffmann, Katrin; Gao, Chao; Petrulionis, Marius; Herr, Ingrid; Schemmer, Peter

    2017-04-01

    Melatonin has been shown to exert anticancer activity on hepatocellular carcinoma (HCC) through its antiproliferative and pro-apoptotic effect in both experimental and clinical studies, and sorafenib is the only approved drug for the systemic treatment of HCC. Thus, this study was designed to investigate the combined effect of melatonin and sorafenib on proliferation, apoptosis, and its possible mechanism in human HCC. Here, we found that both melatonin and sorafenib resulted in a dose-dependent growth inhibition of HuH-7 cells after 48 hours treatment, and the combination of them enhanced the growth inhibition in a synergistic manner. Colony formation assay indicated that co-treatment of HuH-7 cells with melatonin and sorafenib significantly decreased the clonogenicity compared to the treatment with single agent. Furthermore, FACS and TUNEL assay confirmed that melatonin synergistically augmented the sorafenib-induced apoptosis after 48 hours incubation, which was in accordance with the activation of caspase-3 and the JNK/c-jun pathway. Inhibition of JNK/c-jun pathway with its inhibitor SP600125 reversed the phosphorylation of c-jun and the activation of caspase-3 induced by co-treatment of HuH-7 cells with melatonin and sorafenib in a dose-dependent manner. Furthermore, SP600125 exhibited protective effect against apoptosis induced by the combination of melatonin and sorafenib. This study demonstrates that melatonin in combination with sorafenib synergistically inhibits proliferation and induces apoptosis in human HCC cells; therefore, supplementation of sorafenib with melatonin may serve as a potential therapeutic choice for advanced HCC. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. Spinal release of tumour necrosis factor activates c-Jun N-terminal kinase and mediates inflammation-induced hypersensitivity.

    Science.gov (United States)

    Bas, D B; Abdelmoaty, S; Sandor, K; Codeluppi, S; Fitzsimmons, B; Steinauer, J; Hua, X Y; Yaksh, T L; Svensson, C I

    2015-02-01

    Mounting evidence points to individual contributions of tumour necrosis factor-alpha (TNF) and the c-Jun N-terminal kinase (JNK) pathway to the induction and maintenance of various pain states. Here we explore the role of spinal TNF and JNK in carrageenan-induced hypersensitivity. As links between TNF and JNK have been demonstrated in vitro, we investigated if TNF regulates spinal JNK activity in vivo. TNF levels in lumbar cerebrospinal fluid (CSF) were measured by enzyme-linked immunosorbent assay, spinal TNF gene expression by real-time polymerase chain reaction and TNF protein expression, JNK and c-Jun phosphorylation by western blotting. The role of spinal TNF and JNK in inflammation-induced mechanical and thermal hypersensitivity was assessed by injecting the TNF inhibitor etanercept and the JNK inhibitors SP600125 and JIP-1 intrathecally (i.t.). TNF-mediated regulation of JNK activity was examined by assessing the effect of i.t. etanercept on inflammation-induced spinal JNK activity. TNF levels were increased in CSF and spinal cord following carrageenan-induced inflammation. While JNK phosphorylation followed the same temporal pattern as TNF, c-jun was only activated at later time points. Intrathecal injection of TNF and JNK inhibitors attenuated carrageenan-induced mechanical and thermal hypersensitivity. TNF stimulation induced JNK phosphorylation in cultured spinal astrocytes and blocking the spinal actions of TNF in vivo by i.t. injection of etanercept reduced inflammation-induced spinal JNK activity. Here we show that spinal JNK activity is dependent on TNF and that both TNF and the JNK signalling pathways modulate pain-like behaviour induced by peripheral inflammation. © 2014 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation - EFIC®.

  15. cJun NH2-terminal kinase 1 (JNK1): roles in metabolic regulation of insulin resistance

    OpenAIRE

    Sabio, Guadalupe; Davis, Roger J

    2010-01-01

    The cJun NH2-terminal kinase isoform JNK1 is implicated in the mechanism of obesity-induced insulin resistance. Feeding a high fat diet causes activation of the JNK1 signaling pathway, insulin resistance, and obesity in mice. Germ-line ablation of Jnk1 prevents both diet-induced obesity and insulin resistance. Genetic analysis indicates that the effects of JNK1 on insulin resistance can be separated from effects of JNK1 on obesity. Emerging research indicates that JNK1 plays multiple roles in...

  16. Histone H3 variants and their chaperones during development and disease: contributing to epigenetic control.

    Science.gov (United States)

    Filipescu, Dan; Müller, Sebastian; Almouzni, Geneviève

    2014-01-01

    Within the nucleus, the interplay between lineage-specific transcription factors and chromatin dynamics defines cellular identity. Control of this interplay is necessary to properly balance stability and plasticity during the development and entire life span of multicellular organisms. Here, we present our current knowledge of the contribution of histone H3 variants to chromatin dynamics during development. We review the network of histone chaperones that governs their deposition timing and sites of incorporation and highlight how their distinct distribution impacts genome organization and function. We integrate the importance of H3 variants in the context of nuclear reprogramming and cell differentiation, and, using the centromere as a paradigm, we describe a case in which the identity of a given genomic locus is propagated across different cell types. Finally, we compare development to changes in stress and disease. Both physiological and pathological settings underline the importance of H3 dynamics for genome and chromatin integrity.

  17. Fibroblast growth factor-4 enhances proliferation of mouse embryonic stem cells via activation of c-Jun signaling.

    Directory of Open Access Journals (Sweden)

    Sung-Ho Kook

    Full Text Available Fibroblast growth factor-4 (FGF4 is expressed in embryonic stages and in adult tissues, where it plays critical roles in modulating multiple cellular functions. However, the exact roles of FGF4 on proliferation and differentiation of embryonic stem cells (ESCs are not completely understood. Exogenous addition of FGF4 stimulated proliferation of mouse ESCs (mESCs, as proven by the increases in DNA synthesis and cell cycle regulatory protein induction. These increases were almost completely inhibited by pre-treating cells with anti-FGF4 antibody. FGF4 also activated c-Jun N-terminal kinase (JNK and extracellular-signal regulated kinase (ERK signaling, but not p38 kinase. Blockage of JNK signaling by SP600125 or by transfection with its specific siRNA significantly inhibited FGF4-stimulated cell proliferation through the suppression of c-Jun induction and activator protein-1 (AP-1 activity. However, ERK or p38 kinase inhibitor did not affect FGF4-stimulated proliferation in mESCs. FGF4 suppressed osteogenic differentiation of mESCs by inhibiting expression of transcription factors involved in bone formation. Further, exogenous FGF4 addition stimulated proliferation of human periodontal ligament stem cells (hPDLSCs and bone marrow mesenchymal stem cells (BMMSCs via activation of ERK signaling. FGF4 also augmented mineralization of hPDLSCs, but not of BMMSCs. Collectively, it is suggested that FGF4 triggers proliferation of stem cells by activating MAPK-mediated signaling, while it affects differently osteogenic differentiation according to the origins of stem cells.

  18. The c-Jun N-terminal kinase pathway of a vector insect is activated by virus capsid protein and promotes viral replication

    Science.gov (United States)

    Wang, Wei; Zhao, Wan; Li, Jing; Luo, Lan; Kang, Le; Cui, Feng

    2017-01-01

    No evidence has shown whether insect-borne viruses manipulate the c-Jun N-terminal kinase (JNK) signaling pathway of vector insects. Using a system comprising the plant virus Rice stripe virus (RSV) and its vector insect, the small brown planthopper, we have studied the response of the vector insect’s JNK pathway to plant virus infection. We found that RSV increased the level of Tumor Necrosis Factor-α and decreased the level of G protein Pathway Suppressor 2 (GPS2) in the insect vector. The virus capsid protein competitively bound GPS2 to release it from inhibiting the JNK activation machinery. We confirmed that JNK activation promoted RSV replication in the vector, whereas JNK inhibition caused a significant reduction in virus production and thus delayed the disease incidence of plants. These findings suggest that inhibition of insect vector JNK may be a useful strategy for controling the transmission of plant viruses. DOI: http://dx.doi.org/10.7554/eLife.26591.001 PMID:28716183

  19. The intriguing role of fibroblasts and c-Jun in the chemopreventive and therapeutic effect of finasteride on xenograft models of prostate cancer.

    Science.gov (United States)

    Niu, Yi-Nong; Wang, Kai; Jin, Song; Fan, Dong-Dong; Wang, Ming-Shuai; Xing, Nian-Zeng; Xia, Shu-Jie

    2016-01-01

    In a large clinical trial, finasteride reduced the rate of low-grade prostate cancer (PCa) while increasing the incidence of high-grade cancer. Whether finasteride promotes the development of high-grade tumors remains controversial. We demonstrated the role of fibroblasts and c-Jun in chemopreventive and therapeutic effect of finasteride on xenograft models of PCa. LNCaP (PC3) cells or recombinants of cancer cells and fibroblasts were implanted in male athymic nude mice treated with finasteride. Tumor growth, cell proliferation, apoptosis, p-Akt, and p-ERK1/2 were evaluated. In LNCaP (PC3) mono-grafted models, finasteride did not change the tumor growth. In recombinant-grafted models, fibroblasts and c-Jun promoted tumor growth; finasteride induced proliferation of LNCaP cells and repressed PC3 cell apoptosis. When c-Jun was knocked out, fibroblasts and/or finasteride did not promote the tumor growth. Finasteride inhibited p-Akt and p-ERK1/2 in mono-culture cancer cells while stimulating the same signaling molecules in the presence of fibroblasts. Reduced p-Akt and p-ERK1/2 were noted in the presence of c-Jun-/- fibroblasts. Fibroblasts and c-Jun promote PCa growth; finasteride further stimulates tumor growth with promoted proliferation, repressed apoptosis, and up-regulated pro-proliferative molecular pathway in the presence of fibroblasts and c-Jun. Stromal-epithelial interactions play critical roles in finasteride's therapeutic effects on PCa. Our findings have preliminary implications in using finasteride as a chemopreventive or therapeutic agent for PCa patients.

  20. Pregnane and Xenobiotic Receptor gene expression in liver cells is modulated by Ets-1 in synchrony with transcription factors Pax5, LEF-1 and c-jun

    Energy Technology Data Exchange (ETDEWEB)

    Kumari, Sangeeta; Saradhi, Mallampati; Rana, Manjul; Chatterjee, Swagata [Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067 (India); Aumercier, Marc [IRI, CNRS USR 3078, Université de Lille-Nord de France, Parc CNRS de la Haute Borne, 50 Avenue de Halley, BP 70478, 59658 Villeneuve d’Ascq Cedex (France); Mukhopadhyay, Gauranga [Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067 (India); Tyagi, Rakesh K., E-mail: rktyagi@yahoo.com [Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067 (India)

    2015-01-15

    Nuclear receptor PXR is predominantly expressed in liver and intestine. Expression of PXR is observed to be dysregulated in various metabolic disorders indicating its involvement in disease development. However, information available on mechanisms of PXR self-regulation is fragmentary. The present investigation identifies some of the regulatory elements responsible for its tight regulation and low cellular expression. Here, we report that the PXR-promoter is a target for some key transcription factors like PU.1/Ets-1, Pax5, LEF-1 and c-Jun. Interestingly, we observed that PXR-promoter responsiveness to Pax5, LEF-1 and c-Jun, is considerably enhanced by Ets transcription factors (PU.1 and Ets-1). Co-transfection of cells with Ets-1, LEF-1 and c-Jun increased PXR-promoter activity by 5-fold and also induced expression of endogenous human PXR. Site-directed mutagenesis and transfection studies revealed that two Ets binding sites and two of the three LEF binding sites in the PXR-promoter are functional and have a positive effect on PXR transcription. Results suggest that expression of Ets family members, in conjunction with Pax5, LEF-1 and c-Jun, lead to coordinated up-regulation of PXR gene transcription. Insights obtained on the regulation of PXR gene have relevance in offering important cues towards normal functioning as well as development of several metabolic disorders via PXR signaling. - Highlights: • The study identified cis-regulatory elements in the nuclear receptor PXR promoter. • Several trans-acting factors modulating the PXR-promoter have been identified. • PU.1/Ets-1, Pax5, LEF-1, c-Jun, LyF-VI and NF-1 act as modulators of the PXR-promoter. • Ets-1 in conjunction with LEF-1 and c-Jun exhibit 5-fold activation of the PXR-promoter. • Insights into PXR-regulation have relevance in normal and pathological conditions.

  1. [Histone variants and histone exchange].

    Science.gov (United States)

    Wu, Nan; Gui, Jian-Fang

    2006-04-01

    Histones, as the basic components of nucleosome, are essential to chromatin structure and function. To adapt to various states of chromatin, corresponding histone variants are incorporated in nucleosome, and certain modifications also occur on the variants' tails. These variants change the conformation and stability of nucleosome to facilitate transcriptional activation or deactivation, DNA repairing, heterochromatin formation, and others. During histone exchange, chromatin remodeling complex facilitates histone variant deposition into nucleosome, and different variants have diverse deposition pathways. Recently, research on histone variants is not only a new hotspot in epigenetics, but also a new annotation of "histone code". In addition, histone exchange reveals new changing mechanism of DNA-histone interaction.

  2. Predicting Virulence of Aeromonas Isolates Based-on Changes in Transcription of c-jun and c-fos in Human Tissue Culture Cells

    Science.gov (United States)

    Aims: To assess virulence of Aeromonas isolates based on the change in regulation of c-jun and c-fos in the human intestinal tissue culture cell line Caco-2. Methods and Results: Aeromonas cells were added to Caco-2 cells at approximately a one to one ratio. After 1, 2 and 3 ...

  3. Exopolysaccharides from Lactobacillus plantarum NCU116 induce c-Jun dependent Fas/Fasl-mediated apoptosis via TLR2 in mouse intestinal epithelial cancer cells.

    Science.gov (United States)

    Zhou, Xingtao; Hong, Tao; Yu, Qiang; Nie, Shaoping; Gong, Deming; Xiong, Tao; Xie, Mingyong

    2017-10-27

    Exopolysaccharides (EPS) from lactic acid bacteria (LAB) have been reported to play vital parts in the modulation of cell-cycle and apoptosis in cancer cells. However, the mechanisms by which EPS regulate the proliferation and apoptosis of cancer cells remain incompletely understood. We thus used different cancer cells to evaluate the anticancer ability and to investigate the underlying molecular mechanism of EPS from Lactobacillus plantarum NCU116 (EPS116). Our studies showed that EPS116 inhibited the proliferation of cancer cells in a cell type manner, and remarkably repressed the growth and survival of CT26 through induction of apoptosis. Moreover, EPS116 increased the expression of pro-apoptotic genes, including Fas, Fasl and c-Jun, induced the phosphorylation of c-Jun in CT26 cells. Furthermore, TLR2 (Toll like receptor 2) was upregulated by EPS116, and the CT26 cells with TLR2 knockdown were found to be insensitive to EPS116, suggesting that the anti-cancer activity of EPS116 may be TLR2-dependent. Taken together, the suppressive efficacy of EPS116 on the proliferation of CT26 cells may be mediated via TLR2 and the activation of c-Jun dependent Fas/Fasl-mediated apoptotic pathway. Our study has, for the first time, shown that EPS from LAB induced c-Jun dependent Fas/Fasl-mediated apoptosis via TLR2 in CT26 cells.

  4. Induction of c-Jun immunoreactivity in spinal cord and brainstem neurons in a transgenic mouse model for amyotrophic lateral sclerosis

    NARCIS (Netherlands)

    Jaarsma, D.; Holstege, J. C.; Troost, D.; Davis, M.; Kennis, J.; Haasdijk, E. D.; de Jong, V. J.

    1996-01-01

    Transgenic mice carrying amyotrophic lateral sclerosis (ALS)-linked superoxide dismutase 1 (SOD1) mutations develop a motoneuron disease resembling human ALS. c-Jun is a transcription factor frequently induced in injured neurons. In this study we have examined the distribution of

  5. Induction of c-Jun immunoreactivity in spinal cord and brainstem neurons in a transgenic mouse model for amyotrophic lateral sclerosis

    NARCIS (Netherlands)

    D. Jaarsma (Dick); J.C. Holstege (Jan); D. Troost (Dirk); M. Davis (Maria); J.H.H. Kennis (Josette); E.D. Haasdijk (Elize); J.M.B.V. de Jong (Vianney)

    1996-01-01

    textabstractTransgenic mice carrying amyotrophic lateral sclerosis (ALS)-linked superoxide dismutase 1 (SOD1) mutations develop a motoneuron disease resembling human ALS. c-Jun is a transcription factor frequently induced in injured neurons. In this study we have examined the distribution of

  6. Phosphorylation-mediated control of histone chaperone ASF1 levels by Tousled-like kinases.

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    Maxim Pilyugin

    Full Text Available Histone chaperones are at the hub of a diverse interaction networks integrating a plethora of chromatin modifying activities. Histone H3/H4 chaperone ASF1 is a target for cell-cycle regulated Tousled-like kinases (TLKs and both proteins cooperate during chromatin replication. However, the precise role of post-translational modification of ASF1 remained unclear. Here, we identify the TLK phosphorylation sites for both Drosophila and human ASF1 proteins. Loss of TLK-mediated phosphorylation triggers hASF1a and dASF1 degradation by proteasome-dependent and independent mechanisms respectively. Consistent with this notion, introduction of phosphorylation-mimicking mutants inhibits hASF1a and dASF1 degradation. Human hASF1b is also targeted for proteasome-dependent degradation, but its stability is not affected by phosphorylation indicating that other mechanisms are likely to be involved in control of hASF1b levels. Together, these results suggest that ASF1 cellular levels are tightly controlled by distinct pathways and provide a molecular mechanism for post-translational regulation of dASF1 and hASF1a by TLK kinases.

  7. Metformin prevents endoplasmic reticulum stress-induced apoptosis through AMPK-PI3K-c-Jun NH2 pathway

    Science.gov (United States)

    Jung, T.W.; Lee, M.W.; Lee, Y.-J.; Kim, S.M.

    2012-01-01

    Type 2 diabetes mellitus is thought to be partially associated with endoplasmic reticulum (ER) stress toxicity on pancreatic beta cells and the result of decreased insulin synthesis and secretion. In this study, we showed that a well-known insulin sensitizer, metformin, directly protects against dysfunction and death of ER stress-induced NIT-1 cells (a mouse pancreatic beta cell line) via AMP-activated protein kinase (AMPK) and phosphatidylinositol-3 (PI3) kinase activation. We also showed that exposure of NIT-1 cells to metformin (5mM) increases cellular resistance against ER stress-induced NIT-1 cell dysfunction and death. AMPK and PI3 kinase inhibitors abolished the effect of metformin on cell function and death. Metformin-mediated protective effects on ER stress-induced apoptosis were not a result of an unfolded protein response or the induced inhibitors of apoptotic proteins. In addition, we showed that exposure of ER stressed-induced NIT-1 cells to metformin decreases the phosphorylation of c-Jun NH(2) terminal kinase (JNK). These data suggest that metformin is an important determinant of ER stress-induced apoptosis in NIT-1 cells and may have implications for ER stress-mediated pancreatic beta cell destruction via regulation of the AMPK-PI3 kinase-JNK pathway.

  8. Monosodium Urate in the Presence of RANKL Promotes Osteoclast Formation through Activation of c-Jun N-Terminal Kinase

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    Jung-Yoon Choe

    2015-01-01

    Full Text Available The aim of this study was to clarify the role of monosodium urate (MSU crystals in receptor activator of nuclear factor kB ligand- (RANKL- RANK-induced osteoclast formation. RAW 264.7 murine macrophage cells were incubated with MSU crystals or RANKL and differentiated into osteoclast-like cells as confirmed by staining for tartrate-resistant acid phosphatase (TRAP and actin ring, pit formation assay, and TRAP activity assay. MSU crystals in the presence of RANKL augmented osteoclast differentiation, with enhanced mRNA expression of NFATc1, cathepsin K, carbonic anhydrase II, and matrix metalloproteinase-9 (MMP-9, in comparison to RAW 264.7 macrophages incubated in the presence of RANKL alone. Treatment with both MSU crystals and RANKL induced osteoclast differentiation by activating downstream molecules in the RANKL-RANK pathway including tumor necrosis factor receptor-associated factor 6 (TRAF-6, JNK, c-Jun, and NFATc1. IL-1b produced in response to treatment with both MSU and RANKL is involved in osteoclast differentiation in part through the induction of TRAF-6 downstream of the IL-1b pathway. This study revealed that MSU crystals contribute to enhanced osteoclast formation through activation of RANKL-mediated pathways and recruitment of IL-1b. These findings suggest that MSU crystals might be a pathologic causative agent of bone destruction in gout.

  9. c-Jun N-terminal kinase-dependent apoptotic photocytotoxicity of solvent exchange-prepared curcumin nanoparticles.

    Science.gov (United States)

    Paunovic, Verica; Ristic, Biljana; Markovic, Zoran; Todorovic-Markovic, Biljana; Kosic, Milica; Prekodravac, Jovana; Kravic-Stevovic, Tamara; Martinovic, Tamara; Micusik, Matej; Spitalsky, Zdeno; Trajkovic, Vladimir; Harhaji-Trajkovic, Ljubica

    2016-04-01

    Indian spice curcumin is known for its anticancer properties, but the anticancer mechanisms of nanoparticulate curcumin have not been completely elucidated. We here investigated the in vitro anticancer effect of blue light (470 nm, 1 W)-irradiated curcumin nanoparticles prepared by tetrahydrofuran/water solvent exchange, using U251 glioma, B16 melanoma, and H460 lung cancer cells as targets. The size of curcumin nanocrystals was approximately 250 nm, while photoexcitation induced their oxidation and partial agglomeration. Although cell membrane in the absence of light was almost impermeable to curcumin nanoparticles, photoexcitation stimulated their internalization. While irradiation with blue light (1-8 min) or nanocurcumin (1.25-10 μg/ml) alone was only marginally toxic to tumor cells, photoexcited nanocurcumin displayed a significant cytotoxicity depending both on the irradiation time and nanocurcumin concentration. Photoexcited nanocurcumin induced phosphorylation of c-Jun N-terminal kinase (JNK), mitochondrial depolarization, caspase-3 activation, and cleavage of poly (ADP-ribose) polymerase, indicating apoptotic cell death. Accordingly, pharmacologial inhibition of JNK and caspase activity rescued cancer cells from photoexcited nanocurcumin. On the other hand, antioxidant treatment did not reduce photocytotoxicity of nanocurcumin, arguing against the involvement of oxidative stress. By demonstrating the ability of photoexcited nanocurcumin to induce oxidative-stress independent, JNK- and caspase-dependent apoptosis, our results support its further investigation in cancer therapy.

  10. Histone Chaperone Jun Dimerization Protein 2 (JDP2: Role in Cellular Senescence and Aging

    Directory of Open Access Journals (Sweden)

    Yu-Chang Huang

    2010-10-01

    Full Text Available Transcription factor Jun dimerization protein 2 (JDP2 binds directly to histones and DNA, and inhibits p300-mediated acetylation of core histones and reconstituted nucleosomes that contain JDP2-recognition DNA sequences. The region of JDP2 that encompasses its histone-binding domain and DNA-binding region is essential to inhibit histone acetylation by histone acetyltransferases. Moreover, assays of nucleosome assembly in vitro demonstrate that JDP2 also has histone-chaperone activity. The mutation of the region responsible for inhibition of histone acetyltransferase activity within JDP2 eliminates repression of transcription from the c-jun promoter by JDP2, as well as JDP2-mediated inhibition of retinoic-acid-induced differentiation. Thus JDP2 plays a key role as a repressor of cell differentiation by regulating the expression of genes with an activator protein 1 (AP-1 site via inhibition of histone acetylation and/or assembly and disassembly of nucleosomes. Senescent cells show a series of alterations, including flatten and enlarged morphology, increase in nonspecific acidic β-galactosidase activity, chromatin condensation, and changes in gene expression patterns. The onset and maintenance of senescence are regulated by two tumor suppressors, p53 and retinoblastoma proteins. The expression of p53 and retinoblastoma proteins is regulated by two distinct proteins, p16Ink4a and Arf, respectively, which are encoded by cdkn2a. JDP2 inhibits recruitment of the polycomb repressive complexes 1 and 2 (PRC-1 and PRC-2 to the promoter of the gene that encodes p16Ink4a and inhibits the methylation of lysine 27 of histone H3 (H3K27. The PRCs associate with the p16Ink4a/Arf locus in young proliferating cells and dissociate from it in senescent cells. Therefore, it seems that chromatin-remodeling factors that regulate association and dissociation of PRCs, and are controlled by JDP2, might play an important role in the senescence program. The molecular

  11. The intriguing role of fibroblasts and c-Jun in the chemopreventive and therapeutic effect of finasteride on xenograft models of prostate cancer

    Directory of Open Access Journals (Sweden)

    Yi-Nong Niu

    2016-01-01

    Full Text Available In a large clinical trial, finasteride reduced the rate of low-grade prostate cancer (PCa while increasing the incidence of high-grade cancer. Whether finasteride promotes the development of high-grade tumors remains controversial. We demonstrated the role of fibroblasts and c-Jun in chemopreventive and therapeutic effect of finasteride on xenograft models of PCa. LNCaP (PC3 cells or recombinants of cancer cells and fibroblasts were implanted in male athymic nude mice treated with finasteride. Tumor growth, cell proliferation, apoptosis, p-Akt, and p-ERK1/2 were evaluated. In LNCaP (PC3 mono-grafted models, finasteride did not change the tumor growth. In recombinant-grafted models, fibroblasts and c-Jun promoted tumor growth; finasteride induced proliferation of LNCaP cells and repressed PC3 cell apoptosis. When c-Jun was knocked out, fibroblasts and/or finasteride did not promote the tumor growth. Finasteride inhibited p-Akt and p-ERK1/2 in mono-culture cancer cells while stimulating the same signaling molecules in the presence of fibroblasts. Reduced p-Akt and p-ERK1/2 were noted in the presence of c-Jun−/− fibroblasts. Fibroblasts and c-Jun promote PCa growth; finasteride further stimulates tumor growth with promoted proliferation, repressed apoptosis, and up-regulated pro-proliferative molecular pathway in the presence of fibroblasts and c-Jun. Stromal-epithelial interactions play critical roles in finasteride′s therapeutic effects on PCa. Our findings have preliminary implications in using finasteride as a chemopreventive or therapeutic agent for PCa patients.

  12. Using c-Jun to identify fear extinction learning-specific patterns of neural activity that are affected by single prolonged stress.

    Science.gov (United States)

    Knox, Dayan; Stanfield, Briana R; Staib, Jennifer M; David, Nina P; DePietro, Thomas; Chamness, Marisa; Schneider, Elizabeth K; Keller, Samantha M; Lawless, Caroline

    2017-12-29

    Neural circuits via which stress leads to disruptions in fear extinction is often explored in animal stress models. Using the single prolonged stress (SPS) model of post traumatic stress disorder and the immediate early gene (IEG) c-Fos as a measure of neural activity, we previously identified patterns of neural activity through which SPS disrupts extinction retention. However, none of these stress effects were specific to fear or extinction learning and memory. C-Jun is another IEG that is sometimes regulated in a different manner to c-Fos and could be used to identify emotional learning/memory specific patterns of neural activity that are sensitive to SPS. Animals were either fear conditioned (CS-fear) or presented with CSs only (CS-only) then subjected to extinction training and testing. C-Jun was then assayed within neural substrates critical for extinction memory. Inhibited c-Jun levels in the hippocampus (Hipp) and enhanced functional connectivity between the ventromedial prefrontal cortex (vmPFC) and basolateral amygdala (BLA) during extinction training was disrupted by SPS in the CS-fear group only. As a result, these effects were specific to emotional learning/memory. SPS also disrupted inhibited Hipp c-Jun levels, enhanced BLA c-Jun levels, and altered functional connectivity among the vmPFC, BLA, and Hipp during extinction testing in SPS rats in the CS-fear and CS-only groups. As a result, these effects were not specific to emotional learning/memory. Our findings suggest that SPS disrupts neural activity specific to extinction memory, but may also disrupt the retention of fear extinction by mechanisms that do not involve emotional learning/memory. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. (-)-Epigallocatechin-3-gallate decreases thrombin/paclitaxel-induced endothelial tissue factor expression via the inhibition of c-Jun terminal NH2 kinase phosphorylation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Huang-Joe [Institute of Biotechnology, National Tsing Hua University, No. 101, Section 2, Kuang Fu Road, Hsinchu 30013, Taiwan (China); Division of Cardiology, Department of Medicine, China Medical University Hospital, No. 2, Yuh-Der Road, Taichung 40447, Taiwan (China); Lo, Wan-Yu [Department of Medical Research, China Medical University Hospital, No. 2, Yuh-Der Road, Taichung 40447, Taiwan (China); Graduate Integration of Chinese and Western Medicine, China Medical University, No. 91, Hsueh-Shih Road, Taichung 40402, Taiwan (China); Lu, Te-Ling [School of Pharmacy, China Medical University, No. 91, Hsueh-Shih Road, Taichung 40402, Taiwan (China); Huang, Haimei, E-mail: hmhuang@life.nthu.edu.tw [Institute of Biotechnology, National Tsing Hua University, No. 101, Section 2, Kuang Fu Road, Hsinchu 30013, Taiwan (China)

    2010-01-01

    Patients with paclitaxel-eluting stents are concerned with stent thrombosis caused by premature discontinuation of dual antiplatelet therapy or clopidogrel resistance. This study investigates the effect of (-)-epigallocatechin-3-gallate (EGCG) on the expression of thrombin/paclitaxel-induced endothelial tissue factor (TF) expressions in human aortic endothelial cells (HAECs). EGCG was nontoxic to HAECs at 6 h up to a concentration of 25 {mu}mol/L. At a concentration of 25 {mu}mol/L, EGCG pretreatment potently inhibited both thrombin-stimulated and thrombin/paclitaxel-stimulated endothelial TF protein expression. Thrombin and thrombin/paclitaxel-induced 2.6-fold and 2.9-fold increases in TF activity compared with the control. EGCG pretreatment caused a 29% and 38% decrease in TF activity on thrombin and thrombin/paclitaxel treatment, respectively. Real-time polymerase chain reaction (PCR) showed that thrombin and thrombin/paclitaxel-induced 3.0-fold and 4.6-fold TF mRNA expressions compared with the control. EGCG pretreatment caused an 82% and 72% decrease in TF mRNA expression on thrombin and thrombin/paclitaxel treatment, respectively. The c-Jun terminal NH2 kinase (JNK) inhibitor SP600125 reduced thrombin/paclitaxel-induced TF expression. Furthermore, EGCG significantly inhibited the phosphorylation of JNK to 49% of thrombin/paclitaxel-stimulated HAECs at 60 min. Immunofluorescence assay did not show an inhibitory effect of EGCG on P65 NF-{kappa}B nuclear translocation in the thrombin/paclitaxel-stimulated endothelial cells. In conclusion, EGCG can inhibit TF expression in thrombin/paclitaxel-stimulated endothelial cells via the inhibition of JNK phosphorylation. The unique property of EGCG may be used to develop a new drug-eluting stent by co-coating EGCG and paclitaxel.

  14. Murine hematopoietic stem cell dormancy controlled by induction of a novel short form of PSF1 by histone deacetylase inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Han, Yinglu; Gong, Zhi-Yuan [Department of Signal Transduction, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Takakura, Nobuyuki, E-mail: ntakaku@biken.osaka-u.ac.jp [Department of Signal Transduction, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Japan Science Technology Agency, CREST, K' s Gobancho, 7, Gobancho, Chiyoda-ku, Tokyo 102-0076 (Japan)

    2015-06-10

    Hematopoietic stem cells (HSCs) can survive long-term in a state of dormancy. Little is known about how histone deacetylase inhibitors (HDACi) affect HSC kinetics. Here, we use trichostatin A (TSA), a histone deacetylase inhibitor, to enforce histone acetylation and show that this suppresses cell cycle entry by dormant HSCs. Previously, we found that haploinsufficiency of PSF1, a DNA replication factor, led to attenuation of the bone marrow (BM) HSC pool size and lack of acute proliferation after 5-FU ablation. Because PSF1 protein is present in CD34{sup +} transiently amplifying HSCs but not in CD34{sup −} long-term reconstituting-HSCs which are resting in a dormant state, we analyzed the relationship between dormancy and PSF1 expression, and how a histone deacetylase inhibitor affects this. We found that CD34{sup +} HSCs produce long functional PSF1 (PSF1a) but CD34{sup −} HSCs produce a shorter possibly non-functional PSF1 (PSF1b, c, dominantly PSF1c). Using PSF1a-overexpressing NIH-3T3 cells in which the endogenous PSF1 promoter is suppressed, we found that TSA treatment promotes production of the shorter form of PSF1 possibly by inducing recruitment of E2F family factors upstream of the PSF1 transcription start site. Our data document one mechanism by which histone deacetylase inhibitors affect the dormancy of HSCs by regulating the DNA replication factor PSF1. - Highlights: • Hematopoetic stem cell dormancy is controlled by histone deacetylation inhibitors. • Dormancy of HSCs is associated with a shorter form of non-functional PSF1. • Histone deacetylase inhibitors suppress PSF1 promoter activity.

  15. Silymarin suppresses TNF-induced activation of NF-kappa B, c-Jun N-terminal kinase, and apoptosis.

    Science.gov (United States)

    Manna, S K; Mukhopadhyay, A; Van, N T; Aggarwal, B B

    1999-12-15

    Silymarin is a polyphenolic flavonoid derived from milk thistle (Silybum marianum) that has anti-inflammatory, cytoprotective, and anticarcinogenic effects. How silymarin produces these effects is not understood, but it may involve suppression of NF-kappa B, a nuclear transcription factor, which regulates the expression of various genes involved in inflammation, cytoprotection, and carcinogenesis. In this report, we investigated the effect of silymarin on NF-kappa B activation induced by various inflammatory agents. Silymarin blocked TNF-induced activation of NF-kappa B in a dose- and time-dependent manner. This effect was mediated through inhibition of phosphorylation and degradation of Iota kappa B alpha, an inhibitor of NF-kappa B. Silymarin blocked the translocation of p65 to the nucleus without affecting its ability to bind to the DNA. NF-kappa B-dependent reporter gene transcription was also suppressed by silymarin. Silymarin also blocked NF-kappa B activation induced by phorbol ester, LPS, okadaic acid, and ceramide, whereas H2O2-induced NF-kappa B activation was not significantly affected. The effects of silymarin on NF-kappa B activation were specific, as AP-1 activation was unaffected. Silymarin also inhibited the TNF-induced activation of mitogen-activated protein kinase kinase and c-Jun N-terminal kinase and abrogated TNF-induced cytotoxicity and caspase activation. Silymarin suppressed the TNF-induced production of reactive oxygen intermediates and lipid peroxidation. Overall, the inhibition of activation of NF-kappa B and the kinases may provide in part the molecular basis for the anticarcinogenic and anti-inflammatory effects of silymarin, and its effects on caspases may explain its role in cytoprotection.

  16. A peptide fragment of ependymin neurotrophic factor uses protein kinase C and the mitogen-activated protein kinase pathway to activate c-Jun N-terminal kinase and a functional AP-1 containing c-Jun and c-Fos proteins in mouse NB2a cells.

    Science.gov (United States)

    Adams, David S; Hasson, Brendan; Boyer-Boiteau, Anne; El-Khishin, Adam; Shashoua, Victor E

    2003-05-01

    Ependymin (EPN) is a goldfish brain neurotrophic factor previously shown to function in a variety of cellular events related to long-term memory formation and neuronal regeneration. CMX-8933, an 8-amino-acid synthetic peptide fragment of EPN, was designed for aiding an investigation of the biological properties of this glycoprotein. We reported from previous studies that treatment of mouse neuroblastoma (NB2a) cultures with CMX-8933 promotes activation of transcription factor AP-1, a characteristic previously associated with the following full-length neurotrophic factors: nerve growth factor, neurotropin-3, and brain-derived neurotrophic factor. The CMX-8933-activated AP-1 specifically bound an AP-1 consensus probe and appeared to contain c-Jun and c-Fos protein components in antibody supershift experiments. Because AP-1 influences a variety of positive and negative cellular processes, determined in part by its exact protein composition and mechanism of activation, we extended these initial AP-1 observations in the current study to confirm the identity of the CMX-8933-activated c-Jun and c-Fos components. CMX-8933 increases the enzymatic activity of c-Jun N-terminal kinase (JNK), increases the phosphorylation of JNK and c-Jun proteins, and increases the cellular titers of c-Jun and c-Fos mRNAs. Furthermore, the AP-1 activated by CMX-8933 is functional, insofar as it transactivates both synthetic and natural AP-1-dependent reporter plasmids. Inhibition studies indicate that activation of the 8933-induced AP-1 occurs via the mitogen-activated protein kinase pathway. These data are in agreement with the recently proposed model for the conversion of short- to long-term synaptic plasticity and memory, in which a JNK-activated transcription factor AP-1, containing c-Jun and c-Fos components, functions at the top of a hierarchy of transcription factors known to regulate long-term neural plasticity. Copyright 2003 Wiley-Liss, Inc.

  17. Histone deacetylases control neurogenesis in embryonic brain by inhibition of BMP2/4 signaling.

    Directory of Open Access Journals (Sweden)

    Maya Shakèd

    Full Text Available BACKGROUND: Histone-modifying enzymes are essential for a wide variety of cellular processes dependent upon changes in gene expression. Histone deacetylases (HDACs lead to the compaction of chromatin and subsequent silencing of gene transcription, and they have recently been implicated in a diversity of functions and dysfunctions in the postnatal and adult brain including ocular dominance plasticity, memory consolidation, drug addiction, and depression. Here we investigate the role of HDACs in the generation of neurons and astrocytes in the embryonic brain. PRINCIPAL FINDINGS: As a variety of HDACs are expressed in differentiating neural progenitor cells, we have taken a pharmacological approach to inhibit multiple family members. Inhibition of class I and II HDACs in developing mouse embryos with trichostatin A resulted in a dramatic reduction in neurogenesis in the ganglionic eminences and a modest increase in neurogenesis in the cortex. An identical effect was observed upon pharmacological inhibition of HDACs in in vitro-differentiating neural precursors derived from the same brain regions. A reduction in neurogenesis in ganglionic eminence-derived neural precursors was accompanied by an increase in the production of immature astrocytes. We show that HDACs control neurogenesis by inhibition of the bone morphogenetic protein BMP2/4 signaling pathway in radial glial cells. HDACs function at the transcriptional level by inhibiting and promoting, respectively, the expression of Bmp2 and Smad7, an intracellular inhibitor of BMP signaling. Inhibition of the BMP2/4 signaling pathway restored normal levels of neurogenesis and astrogliogenesis to both ganglionic eminence- and cortex-derived cultures in which HDACs were inhibited. CONCLUSIONS: Our results demonstrate a transcriptionally-based regulation of BMP2/4 signaling by HDACs both in vivo and in vitro that is critical for neurogenesis in the ganglionic eminences and that modulates cortical

  18. Phosphorylation of purified mitochondrial Voltage-Dependent Anion Channel by c-Jun N-terminal Kinase-3 modifies channel voltage-dependence.

    Science.gov (United States)

    Gupta, Rajeev; Ghosh, Subhendu

    2017-06-01

    Voltage-Dependent Anion Channel (VDAC) phosphorylated by c-Jun N-terminal Kinase-3 (JNK3) was incorporated into the bilayer lipid membrane. Single-channel electrophysiological properties of the native and the phosphorylated VDAC were compared. The open probability versus voltage curve of the native VDAC displayed symmetry around the voltage axis, whereas that of the phosphorylated VDAC showed asymmetry. This result indicates that phosphorylation by JNK3 modifies voltage-dependence of VDAC.

  19. c-Jun N-terminal kinase is required for thermotherapy-induced apoptosis in human gastric cancer cells.

    Science.gov (United States)

    Xiao, Feng; Liu, Bin; Zhu, Qing-Xian

    2012-12-28

    To investigate the role of c-Jun N-terminal kinase (JNK) in thermotherapy-induced apoptosis in human gastric cancer SGC-7901 cells. Human gastric cancer SGC-7901 cells were cultured in vitro. Following thermotherapy at 43°C for 0, 0.5, 1, 2 or 3 h, the cells were cultured for a further 24 h with or without the JNK specific inhibitor, SP600125 for 2 h. Apoptosis was evaluated by immunohistochemistry [terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)] and flow cytometry (Annexin vs propidium iodide). Cell proliferation was determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. The production of p-JNK, Bcl-2, Bax and caspase-3 proteins was evaluated by Western blotting. The expression of JNK at mRNA level was determined by reverse transcription polymerase chain reaction. The proliferation of gastric carcinoma SGC-7901 cells was significantly inhibited following thermotherapy, and was 32.7%, 30.6%, 43.8% and 52.9% at 0.5, 1, 2 and 3 h post-thermotherapy, respectively. Flow cytometry analysis revealed an increased population of SGC-790l cells in G0/G1 phase, but a reduced population in S phase following thermotherapy for 1 or 2 h, compared to untreated cells (P thermotherapy for 0.5, 1, 2 or 3 h, compared to the untreated group (46.5% ± 0.23%, 39.9% ± 0.53%, 56.6% ± 0.35% and 50.4% ± 0.29% vs 7.3% ± 0.10%, P thermotherapy, compared to mock-inhibitor treatment, which was in line with the decreased rate of apoptosis. The expression of Bcl-2 was consistent with thermotherapy alone. Thermotherapy induced apoptosis in gastric cancer cells by promoting p-JNK at the mRNA and protein levels, and up-regulated the expression of Bax and caspase-3 proteins. Bcl-2 may play a protective role during thermotherapy. Activation of JNK via the Bax-caspase-3 pathway may be important in thermotherapy-induced apoptosis in gastric cancer cells.

  20. Antinociceptive Effect of Najanalgesin from Naja Naja Atra in a Neuropathic Pain Model via Inhibition of c-Jun NH2-terminal Kinase.

    Science.gov (United States)

    Liang, Ying-Xia; Zhang, Zhi-Yu; Zhang, Rui

    2015-09-05

    Najanalgesin, a toxin isolated from the venom of Naja naja atra, has been shown to exert significant analgesic effects in a neuropathic pain model in rats. However, the molecular mechanism underlying this protective effect of najanalgesin is poorly understood. The present study sought to evaluate the intracellular signaling pathways that are involved in the antinociceptive effect of najanalgesin on neuropathic pain. The antinociceptive properties of najanalgesin were tested in hind paw withdrawal thresholds in response to mechanical stimulation. We analyzed the participation of the mitogen-activated protein kinase p38, extracellular-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) by western blot analysis. This inhibition of JNK was confirmed by immunohistochemistry. The phosphorylation levels of JNK (as well as its downstream molecule c-Jun), p38, and ERK were significantly increased after injury. Najanalgesin only inhibited JNK and c-Jun phosphorylation but had no effect on either ERK or p38. This inhibition of JNK was confirmed by immunohistochemistry, which suggested that the antinociceptive effect of najanalgesin on spinal nerve ligation-induced neuropathic pain in rats is associated with JNK activation in the spinal cord. The antinociceptive effect of najanalgesin functions by inhibiting the JNK in a neuropathic pain model.

  1. Germline mutations affecting the histone H4 core cause a developmental syndrome by altering DNA damage response and cell cycle control

    NARCIS (Netherlands)

    Tessadori, Federico; Giltay, Jacques C; Hurst, Jane A; Massink, Maarten P; Duran, Karen; Vos, Harmjan R; van Es, Robert M; Scott, Richard H; van Gassen, Koen L I; Bakkers, Jeroen; van Haaften, Gijs

    2017-01-01

    Covalent modifications of histones have an established role as chromatin effectors, as they control processes such as DNA replication and transcription, and repair or regulate nucleosomal structure. Loss of modifications on histone N tails, whether due to mutations in genes belonging to

  2. Developmentally Regulated Post-translational Modification of Nucleoplasmin Controls Histone Sequestration and Deposition

    Directory of Open Access Journals (Sweden)

    Takashi Onikubo

    2015-03-01

    Full Text Available Nucleoplasmin (Npm is an abundant histone chaperone in vertebrate oocytes and embryos. During embryogenesis, regulation of Npm histone binding is critical for its function in storing and releasing maternal histones to establish and maintain the zygotic epigenome. Here, we demonstrate that Xenopus laevis Npm post-translational modifications (PTMs specific to the oocyte and egg promote either histone deposition or sequestration, respectively. Mass spectrometry and Npm phosphomimetic mutations used in chromatin assembly assays identified hyperphosphorylation on the N-terminal tail as a critical regulator for sequestration. C-terminal tail phosphorylation and PRMT5-catalyzed arginine methylation enhance nucleosome assembly by promoting histone interaction with the second acidic tract of Npm. Electron microscopy reconstructions of Npm and TTLL4 activity toward the C-terminal tail demonstrate that oocyte- and egg-specific PTMs cause Npm conformational changes. Our results reveal that PTMs regulate Npm chaperoning activity by modulating Npm conformation and Npm-histone interaction, leading to histone sequestration in the egg.

  3. Control of human cytomegalovirus gene expression by differential histone modifications during lytic and latent infection of a monocytic cell line.

    Science.gov (United States)

    Ioudinkova, Elena; Arcangeletti, Maria Cristina; Rynditch, Alla; De Conto, Flora; Motta, Federica; Covan, Silvia; Pinardi, Federica; Razin, Sergey V; Chezzi, Carlo

    2006-12-15

    Non-differentiated THP-1 cells can be infected by human cytomegalovirus (HCMV) Towne strain, which persists in these cells in a non-active (latent) form without undergoing a productive cycle. The same cells become permissive for HCMV lytic infection after induction of cell differentiation by treatment with 12-O-tetradecanoylphorbol-13-acetate. We used this cellular model to study the possible role of histone modifications in the control of HCMV latency. Using chromatin immunoprecipitation with antibodies against histone H3 acetylated or dimethylated in position K9, we demonstrated that in lytically infected cells the HCMV enhancer was associated with heavy acetylated but not dimethylated H3. In the case of latent infection, the HCMV enhancer was associated with neither acetylated nor dimethylated H3. HCMV genes encoding DNA polymerase (early), pp65 (early-late) and pp150 (late) proteins were associated preferentially with acetylated H3 in lytically infected cells and with dimethylated H3 in latently infected cells. These data strongly suggest that K9 methylation of H3 is involved in HCMV gene repression, while association of the above genes with acetylated histones is likely to be necessary for active transcription. It can be postulated that the same histone modifications are used to mark active and repressed genes in both cellular and viral chromatin.

  4. Histone H3K9 trimethylase Eggless controls germline stem cell maintenance and differentiation.

    Directory of Open Access Journals (Sweden)

    Xiaoxi Wang

    2011-12-01

    study has revealed the essential roles of histone H3K9 trimethylation in controlling stem cell maintenance and differentiation through distinct mechanisms.

  5. Phosphorylation-mediated control of histone chaperone ASF1 levels by tousled-like kinases

    OpenAIRE

    Maxim Pilyugin; Jeroen Demmers; Peter Verrijzer, C.; Francois Karch; Moshkin, Yuri M.

    2009-01-01

    textabstractHistone chaperones are at the hub of a diverse interaction networks integrating a plethora of chromatin modifying activities. Histone H3/H4 chaperone ASF1 is a target for cell-cycle regulated Tousled-like kinases (TLKs) and both proteins cooperate during chromatin replication. However, the precise role of post-translational modification of ASF1 remained unclear. Here, we identify the TLK phosphorylation sites for both Drosophila and human ASF1 proteins. Loss of TLK- mediated phosp...

  6. Epigenetic Regulation of Axonal Growth of Drosophila Pacemaker Cells by Histone Acetyltransferase Tip60 Controls Sleep

    Science.gov (United States)

    Pirooznia, Sheila K.; Chiu, Kellie; Chan, May T.; Zimmerman, John E.; Elefant, Felice

    2012-01-01

    Tip60 is a histone acetyltransferase (HAT) enzyme that epigenetically regulates genes enriched for neuronal functions through interaction with the amyloid precursor protein (APP) intracellular domain. However, whether Tip60-mediated epigenetic dysregulation affects specific neuronal processes in vivo and contributes to neurodegeneration remains unclear. Here, we show that Tip60 HAT activity mediates axonal growth of the Drosophila pacemaker cells, termed “small ventrolateral neurons” (sLNvs), and their production of the neuropeptide pigment-dispersing factor (PDF) that functions to stabilize Drosophila sleep–wake cycles. Using genetic approaches, we show that loss of Tip60 HAT activity in the presence of the Alzheimer’s disease-associated APP affects PDF expression and causes retraction of the sLNv synaptic arbor required for presynaptic release of PDF. Functional consequence of these effects is evidenced by disruption of the sleep–wake cycle in these flies. Notably, overexpression of Tip60 in conjunction with APP rescues these sleep–wake disturbances by inducing overelaboration of the sLNv synaptic terminals and increasing PDF levels, supporting a neuroprotective role for dTip60 in sLNv growth and function under APP-induced neurodegenerative conditions. Our findings reveal a novel mechanism for Tip60 mediated sleep–wake regulation via control of axonal growth and PDF levels within the sLNv-encompassing neural network and provide insight into epigenetic-based regulation of sleep disturbances observed in neurodegenerative diseases like Alzheimer’s disease. PMID:22982579

  7. Timing of transcriptional quiescence during gametogenesis is controlled by global histone H3K4 demethylation.

    Science.gov (United States)

    Xu, Mengshu; Soloveychik, Maria; Ranger, Mathieu; Schertzberg, Michael; Shah, Zarna; Raisner, Ryan; Venkatasubrahmanyan, Shivkumar; Tsui, Kyle; Gebbia, Marinella; Hughes, Tim; van Bakel, Harm; Nislow, Corey; Madhani, Hiten D; Meneghini, Marc D

    2012-11-13

    Gametes are among the most highly specialized cells produced during development. Although gametogenesis culminates in transcriptional quiescence in plants and animals, regulatory mechanisms controlling this are unknown. Here, we confirm that gamete differentiation in the single-celled yeast Saccharomyces cerevisiae is accompanied by global transcriptional shutoff following the completion of meiosis. We show that Jhd2, a highly conserved JARID1-family histone H3K4 demethylase, activates protein-coding gene transcription in opposition to this programmed transcriptional shutoff, sustaining the period of productive transcription during spore differentiation. Moreover, using genome-wide nucleosome, H3K4me, and transcript mapping experiments, we demonstrate that JHD2 globally represses intergenic noncoding transcription during this period. The widespread transcriptional defects of JHD2 mutants are associated with precocious differentiation and the production of stress-sensitive spores, demonstrating that Jhd2 regulation of the global postmeiotic transcriptional program is critical for the production of healthy meiotic progeny. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Dynamic Control of X Chromosome Conformation and Repression by a Histone H4K20 Demethylase.

    Science.gov (United States)

    Brejc, Katjuša; Bian, Qian; Uzawa, Satoru; Wheeler, Bayly S; Anderson, Erika C; King, David S; Kranzusch, Philip J; Preston, Christine G; Meyer, Barbara J

    2017-09-21

    Chromatin modification and higher-order chromosome structure play key roles in gene regulation, but their functional interplay in controlling gene expression is elusive. We have discovered the machinery and mechanism underlying the dynamic enrichment of histone modification H4K20me1 on hermaphrodite X chromosomes during C. elegans dosage compensation and demonstrated H4K20me1's pivotal role in regulating higher-order chromosome structure and X-chromosome-wide gene expression. The structure and the activity of the dosage compensation complex (DCC) subunit DPY-21 define a Jumonji demethylase subfamily that converts H4K20me2 to H4K20me1 in worms and mammals. Selective inactivation of demethylase activity eliminates H4K20me1 enrichment in somatic cells, elevates X-linked gene expression, reduces X chromosome compaction, and disrupts X chromosome conformation by diminishing the formation of topologically associating domains (TADs). Unexpectedly, DPY-21 also associates with autosomes of germ cells in a DCC-independent manner to enrich H4K20me1 and trigger chromosome compaction. Our findings demonstrate the direct link between chromatin modification and higher-order chromosome structure in long-range regulation of gene expression. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Reactive Oxygen Species-Dependent Apoptosis by Gugulipid Extract of Ayurvedic Medicine Plant Commiphora mukul in Human Prostate Cancer Cells Is Regulated by c-Jun N-Terminal KinaseS⃞

    Science.gov (United States)

    Zeng, Yan; Prakash, Lakshmi; Badmaev, Vladmir; Majeed, Muhammed; Singh, Shivendra V.

    2011-01-01

    Gugulipid (GL), extract of Indian Ayurvedic medicinal plant Commiphora mukul, has been used to treat a variety of ailments. We report an anticancer effect and mechanism of GL against human prostate cancer cells. Treatment with GL significantly inhibited the viability of human prostate cancer cell line LNCaP (androgen-dependent) and its androgen-independent variant (C81) with an IC50 of ∼1 μM (24-h treatment), at pharmacologically relevant concentrations standardized to its major active constituent z-guggulsterone. The GL-induced growth inhibition correlated with apoptosis induction as evidenced by an increase in cytoplasmic histone-associated DNA fragmentation and sub-G0/G1-DNA fraction, and cleavage of poly(ADP-ribose) polymerase. The GL-induced apoptosis was associated with reactive oxygen species (ROS) production and c-Jun NH2-terminal kinase (JNK) activation. The induction of proapoptotic Bcl-2 family proteins Bax and Bak and a decrease of antiapoptotic Bcl-2 protein Bcl-2 were observed in GL-treated cells. SV40 immortalized mouse embryonic fibroblasts derived from Bax-Bak double-knockout mice were significantly more resistant to GL-induced cell killing compared with wild-type cells. It is interesting to note that a representative normal prostate epithelial cell line (PrEC) was relatively more resistant to GL-mediated cellular responses compared with prostate cancer cells. The GL treatment caused the activation of JNK that functioned upstream of Bax activation in apoptosis response. The GL-induced conformational change of Bax and apoptosis were significantly suppressed by genetic suppression of JNK activation. In conclusion, the present study indicates that ROS-dependent apoptosis by GL is regulated by JNK signaling axis. PMID:21115635

  10. Reactive oxygen species-dependent apoptosis by gugulipid extract of Ayurvedic medicine plant Commiphora mukul in human prostate cancer cells is regulated by c-Jun N-terminal kinase.

    Science.gov (United States)

    Xiao, Dong; Zeng, Yan; Prakash, Lakshmi; Badmaev, Vladmir; Majeed, Muhammed; Singh, Shivendra V

    2011-03-01

    Gugulipid (GL), extract of Indian Ayurvedic medicinal plant Commiphora mukul, has been used to treat a variety of ailments. We report an anticancer effect and mechanism of GL against human prostate cancer cells. Treatment with GL significantly inhibited the viability of human prostate cancer cell line LNCaP (androgen-dependent) and its androgen-independent variant (C81) with an IC(50) of ∼1 μM (24-h treatment), at pharmacologically relevant concentrations standardized to its major active constituent z-guggulsterone. The GL-induced growth inhibition correlated with apoptosis induction as evidenced by an increase in cytoplasmic histone-associated DNA fragmentation and sub-G(0)/G(1)-DNA fraction, and cleavage of poly(ADP-ribose) polymerase. The GL-induced apoptosis was associated with reactive oxygen species (ROS) production and c-Jun NH(2)-terminal kinase (JNK) activation. The induction of proapoptotic Bcl-2 family proteins Bax and Bak and a decrease of antiapoptotic Bcl-2 protein Bcl-2 were observed in GL-treated cells. SV40 immortalized mouse embryonic fibroblasts derived from Bax-Bak double-knockout mice were significantly more resistant to GL-induced cell killing compared with wild-type cells. It is interesting to note that a representative normal prostate epithelial cell line (PrEC) was relatively more resistant to GL-mediated cellular responses compared with prostate cancer cells. The GL treatment caused the activation of JNK that functioned upstream of Bax activation in apoptosis response. The GL-induced conformational change of Bax and apoptosis were significantly suppressed by genetic suppression of JNK activation. In conclusion, the present study indicates that ROS-dependent apoptosis by GL is regulated by JNK signaling axis.

  11. Alcohol induces RNA polymerase III-dependent transcription through c-Jun by co-regulating TATA-binding protein (TBP) and Brf1 expression.

    Science.gov (United States)

    Zhong, Shuping; Machida, Keigo; Tsukamoto, Hide; Johnson, Deborah L

    2011-01-28

    Chronic alcohol consumption is associated with steatohepatitis and cirrhosis, enhancing the risk for hepatocellular carcinoma. RNA polymerase (pol) III transcribes a variety of small, untranslated RNAs, including tRNAs and 5S rRNAs, which determine the biosynthetic capacity of cells. Increased RNA pol III-dependent transcription, observed in transformed cells and human tumors, is required for oncogenic transformation. Given that alcohol consumption increases risk for liver cancer, we examined whether alcohol regulates this class of genes. Ethanol induces RNA pol III-dependent transcription in both HepG2 cells and primary mouse hepatocytes in a manner that requires ethanol metabolism and the activation of JNK1. This regulatory event is mediated, at least in part, through the ability of ethanol to induce expression of the TFIIIB components, Brf1, and the TATA-binding protein (TBP). Induction of TBP, Brf1, and RNA pol III-dependent gene expression is driven by enhanced c-Jun expression. Ethanol promotes a marked increase in the direct recruitment of c-Jun to TBP, Brf1, and tRNA gene promoters. Chronic alcohol administration in mice leads to enhanced expression of TBP, Brf1, tRNA, and 5S rRNA gene transcription in the liver. These alcohol-dependent increases are more pronounced in transgenic animals that express the HCV NS5A protein that display increased incidence of liver tumors. Together, these results identify a new class of genes that are regulated by alcohol through the co-regulation of TFIIIB components and define a central role for c-Jun in this process.

  12. c-Jun NH2-terminal kinase-dependent upregulation of DR5 mediates cooperative induction of apoptosis by perifosine and TRAIL

    Directory of Open Access Journals (Sweden)

    Chen Georgia Z

    2010-12-01

    Full Text Available Abstract Background Perifosine, an alkylphospholipid tested in phase II clinical trials, modulates the extrinsic apoptotic pathway and cooperates with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL to augment apoptosis. The current study focuses on revealing the mechanisms by which perifosine enhances TRAIL-induced apoptosis. Results The combination of perifosine and TRAIL was more active than each single agent alone in inducing apoptosis of head and neck squamous cell carcinoma cells and inhibiting the growth of xenografts. Interestingly, perifosine primarily increased cell surface levels of DR5 although it elevated the expression of both DR4 and DR5. Blockade of DR5, but not DR4 upregulation, via small interfering RNA (siRNA inhibited perifosine/TRAIL-induced apoptosis. Perifosine increased phosphorylated c-Jun NH2-terminal kinase (JNK and c-Jun levels, which were paralleled with DR4 and DR5 induction. However, only DR5 upregulaiton induced by perifosine could be abrogated by both the JNK inhibitor SP600125 and JNK siRNA. The antioxidants, N-acetylcysteine and glutathione, but not vitamin C or tiron, inhibited perifosine-induced elevation of p-c-Jun, DR4 and DR5. Moreover, no increased production of reactive oxygen species was detected in perifosine-treated cells although reduced levels of intracellular GSH were measured. Conclusions DR5 induction plays a critical role in mediating perifosine/TRAIL-induced apoptosis. Perifosine induces DR5 expression through a JNK-dependent mechanism independent of reactive oxygen species.

  13. Modulation of c-Jun NH2-Terminal (JNK) by Cholinergic Autoantibodies from Patients with Sjögren’s Syndrome

    OpenAIRE

    Borda, Enri Santiago; Passafaro, Daniela; Reina, Silvia; Sterin Borda, Leonor

    2017-01-01

    Background: We wanted to determine (via an immunopharmacological approach) whether the c-Jun NH2 terminal kinase (JNK) cascade is phosphorylated in the submandibular gland by carbachol and cholinergic autoantibodies (IgG) present in the sera of patients with primary Sjögren’s syndrome (pSS) by interaction and activation of salivary gland muscarinic acetylcholine receptors (mAChRs). Methods: The JNK, PGE2 and NOS assays were measured in rat sub- mandibular gland with pSS IgG and carbachol alon...

  14. c-myc, c-fos, and c-jun regulation in the regenerating livers of normal and H-2K/c-myc transgenic mice.

    OpenAIRE

    Morello, D; Fitzgerald, M J; Babinet, C; Fausto, N

    1990-01-01

    We investigated the mechanisms of regulation of c-myc, c-fos, and c-jun at the early stages of liver regeneration in mice. We show that the transient increase in steady-state levels of c-myc mRNA at the start of liver regeneration is most probably regulated by posttranscriptional mechanisms. Although there was a marked increase in c-myc transcriptional initiation shortly after partial hepatectomy, a block in elongation prevented the completion of most transcripts. To gain further information ...

  15. Calcium has a permissive role in interleukin-1beta-induced c-jun N-terminal kinase activation in insulin-secreting cells

    DEFF Research Database (Denmark)

    Størling, Joachim; Zaitsev, Sergei V; Kapelioukh, Iouri L

    2005-01-01

    The c-jun N-terminal kinase (JNK) signaling pathway mediates IL-1beta-induced apoptosis in insulin-secreting cells, a mechanism relevant to the destruction of pancreatic beta-cells in type 1 and 2 diabetes. However, the mechanisms that contribute to IL-1beta activation of JNK in beta-cells are la......+) ionophore A23187, or exposure to thapsigargin, an inhibitor of sarco(endo)plasmic reticulum Ca(2+) ATPase, all caused an amplification of IL-1beta-induced JNK activation in INS-1 cells. Finally, a chelator of intracellular free Ca(2+) [bis-(o-aminophenoxy)-N,N,N',N'-tetraacetic acid...

  16. A circadian rhythm orchestrated by histone deacetylase 3 controls hepatic lipid metabolism

    DEFF Research Database (Denmark)

    Feng, Dan; Liu, Tao; Sun, Zheng

    2011-01-01

    Disruption of the circadian clock exacerbates metabolic diseases, including obesity and diabetes. We show that histone deacetylase 3 (HDAC3) recruitment to the genome displays a circadian rhythm in mouse liver. Histone acetylation is inversely related to HDAC3 binding, and this rhythm is lost when...... HDAC3 is absent. Although amounts of HDAC3 are constant, its genomic recruitment in liver corresponds to the expression pattern of the circadian nuclear receptor Rev-erbα. Rev-erbα colocalizes with HDAC3 near genes regulating lipid metabolism, and deletion of HDAC3 or Rev-erbα in mouse liver causes...... hepatic steatosis. Thus, genomic recruitment of HDAC3 by Rev-erbα directs a circadian rhythm of histone acetylation and gene expression required for normal hepatic lipid homeostasis....

  17. Drosophila histone deacetylase-3 controls imaginal disc size through suppression of apoptosis.

    Directory of Open Access Journals (Sweden)

    Changqi C Zhu

    2008-02-01

    Full Text Available Histone deacetylases (HDACs execute biological regulation through post-translational modification of chromatin and other cellular substrates. In humans, there are eleven HDACs, organized into three distinct subfamilies. This large number of HDACs raises questions about functional overlap and division of labor among paralogs. In vivo roles are simpler to address in Drosophila, where there are only five HDAC family members and only two are implicated in transcriptional control. Of these two, HDAC1 has been characterized genetically, but its most closely related paralog, HDAC3, has not. Here we describe the isolation and phenotypic characterization of hdac3 mutations. We find that both hdac3 and hdac1 mutations are dominant suppressors of position effect variegation, suggesting functional overlap in heterochromatin regulation. However, all five hdac3 loss-of-function alleles are recessive lethal during larval/pupal stages, indicating that HDAC3 is essential on its own for Drosophila development. The mutant larvae display small imaginal discs, which result from abnormally elevated levels of apoptosis. This cell death occurs as a cell-autonomous response to HDAC3 loss and is accompanied by increased expression of the pro-apoptotic gene, hid. In contrast, although HDAC1 mutants also display small imaginal discs, this appears to result from reduced proliferation rather than from elevated apoptosis. The connection between HDAC loss and apoptosis is important since HDAC inhibitors show anticancer activities in animal models through mechanisms involving apoptotic induction. However, the specific HDACs implicated in tumor cell killing have not been identified. Our results indicate that protein deacetylation by HDAC3 plays a key role in suppression of apoptosis in Drosophila imaginal tissue.

  18. Src Inhibition Can Synergize with Gemcitabine and Reverse Resistance in Triple Negative Breast Cancer Cells via the AKT/c-Jun Pathway.

    Directory of Open Access Journals (Sweden)

    Zhen-Hua Wu

    Full Text Available Gemcitabine-based chemotherapy remains one of the standards in management of metastatic breast cancer. However, intrinsic and acquired resistance to gemcitabine inevitably occurs. The aims of this study were to assess the efficacy of the combination of src inhibition and gemcitabine in gemcitabine-resistant breast cancer cells.By using colony formation, sphere forming, flow cytometry, cell counting kit-8 and transwell assays, 231/GEM-res (gemcitabine-resistant cell line, which was 10 times more resistant, was shown to have elevated drug tolerance, enhanced proliferative and self-renewal abilities, compared with its parental cells. Inhibition of src by both saracatinib (AZD0530 and siRNA could partially reverse gemcitabine resistance and attenuate resistance-associated anti-apoptosis, migration and stem cell capacities. In addition, the combination of src inhibition and gemcitabine had synergistic antitumor effects. Western blot analysis revealed up-regulation of pro-apoptotic protein BAX, along with the down-regulation of anti-apoptotic proteins (BCL-XL, Survivin, migration associated proteins (p-FAK, MMP-3 and cancer stem cell (CSC markers (CD44, Oct-4, which was probably mediated by AKT/c-Jun pathway.In highly gemcitabine-resistant 231 cells, src inhibition can synergize with gemcitabine, reverse drug resistance, inhibit tumor growth/metastasis/stemness of cancer stem cells, possibly via the AKT/c-Jun pathway.

  19. Histone Arginine Methylation by PRMT7 Controls Germinal Center Formation via Regulating Bcl6 Transcription.

    Science.gov (United States)

    Ying, Zhengzhou; Mei, Mei; Zhang, Peizhun; Liu, Chunyi; He, Huacheng; Gao, Fei; Bao, Shilai

    2015-08-15

    B cells are the center of humoral immunity and produce Abs to protect against foreign Ags. B cell defects lead to diseases such as leukemia and lymphomas. Histone arginine methylation is important for regulating gene activation and silencing in cells. Although the process commonly exists in mammalian cells, its roles in B cells are unknown. To explore the effects of aberrant histone arginine methylation on B cells, we generated mice with a B cell-specific knockout of PRMT7, a member of the methyltransferases that mediate arginine methylation of histones. In this article, we showed that the loss of PRMT7 led to decreased mature marginal zone B cells and increased follicular B cells and promoted germinal center formation after immunization. Furthermore, mice lacking PRMT7 expression in B cells secreted low levels of IgG1 and IgA. Abnormal expression of germinal center genes (i.e., Bcl6, Prdm1, and Irf4) was detected in conditional knockout mice. By overexpressing PRMT7 in the Raji and A20 cell lines derived from B cell lymphomas, we validated the fact that PRMT7 negatively regulated Bcl6 expression. Using chromatin immunoprecipitation-PCR, we found that PRMT7 could recruit H4R3me1 and symmetric H4R3me2 to the Bcl6 promoter. These results provide evidence for the important roles played by PRMT7 in germinal center formation. Copyright © 2015 by The American Association of Immunologists, Inc.

  20. CDK inhibitors selectively diminish cell cycle controlled activation of the histone H4 gene promoter by p220NPAT and HiNF-P

    Science.gov (United States)

    Mitra, Partha; Ghule, Prachi N.; van der Deen, Margaretha; Medina, Ricardo; Xie, Rong-lin; Holmes, William F.; Ye, Xin; Nakayama, Keiichi I.; Harper, J. Wade; Stein, Janet L.; Stein, Gary S.; van Wijnen, Andre J.

    2010-01-01

    Cell cycle progression into S phase requires the induction of histone gene expression to package newly synthesized DNA as chromatin. Cyclin E stimulation of CDK2 at the Restriction point late in G1 controls both histone gene expression by the p220NPAT/HiNF-P pathway and initiation of DNA replication through the pRB/E2F pathway. The three CDK inhibitors (CKIs) p21CIP1/WAF1, p27KIP1 and p57KIP2 attenuate CDK2 activity. Here we find that γ-irradiation induces p21CIP1/WAF1 but not the other two CKIs, while reducing histone H4 mRNA levels but not histone H4 gene promoter activation by the p220NPAT/HiNF-P complex. We also show that p21CIP1/WAF1 is less effective than p27KIP1 and p57KIP2 in inhibiting the CDK2 dependent phosphorylation of p220NPAT at subnuclear foci and transcriptional activation of histone H4 genes. The greater effectiveness of p57KIP2 in blocking the p220NPAT/HiNF-P pathway is attributable in part to its ability to form a specific complex with p220NPAT that may suppress CDK2/cyclin E phosphorylation through direct substrate inhibition. We conclude that CKIs selectively control stimulation of the histone H4 gene promoter by the p220NPAT/HiNF-P complex. PMID:19170105

  1. Effects of different therapeutic methods and typical recipes of Chinese medicine on activation of c-Jun N-terminal kinase in kupffer cells of rats with fatty liver disease.

    Science.gov (United States)

    Yang, Qin-He; Hu, Si-Ping; Zhang, Yu-Pei; Ping, Huan-Huan; Yang, Huan-Wen; Chen, Tong-Yan; Liu, Hai-Tao

    2012-10-01

    To observe the effects of different therapeutic methods and the recipes of Chinese medicine (CM) on the activation of c-Jun N-terminal kinase (JNK) in Kupffer cells of rats with fatty liver disease and to explore the mechanisms of these therapeutic methods. By using a random number table, 98 rats were randomly divided into 7 groups: control group, model group, and 5 treatment groups, including soothing Liver (Gan) recipe group, invigorating Spleen (Pi) recipe group, dispelling dampness recipe group, promoting blood recipe group, and complex recipe group. Rats in the control group were fed with normal food and distilled water by gastric perfusion, while rats in the model group were fed with high-fat food and distilled spirits by gastric perfusion. Rats in the 5 treatment groups were fed with high-fat food and corresponding recipes by gastric perfusion. Twelve weeks later, all rats were sacrificed and liver tissues were stained for pathohistological observation. Kupffer cells were isolated from livers of rats to evaluate JNK and phospho-JNK expressions by Western blotting. The grade of hepatic steatosis was higher in the model group than the control group (PLiver recipe group and invigorating Spleen recipe group were significantly ameliorated (Pliver disease in rats. The recipes of CM, especially invigorating Spleen recipe and soothing Liver recipe, might protect liver against injury by reducing the total JNK protein content and inhibiting the activation of JNK protein in Kupffer cells of fatty liver model rats, which showed beneficial effects on fatty liver disease.

  2. Identification of a c-Jun N-terminal kinase-2-dependent signal amplification cascade that regulates c-Myc levels in ras transformation

    DEFF Research Database (Denmark)

    Mathiasen, D.P.; Egebjerg, C.; Andersen, S.H.

    2012-01-01

    that is critical for ras transformation in murine embryonic fibroblasts. This cascade is coordinated by ERK and JNK2 MAPKs, whose Ras-mediated activation leads to the enhanced levels of three oncogenic transcription factors, namely, c-Myc, activating transcription factor 2 (ATF2) and ATF3, all of which...... are essential for ras transformation. Previous studies show that ERK-mediated serine 62 phosphorylation protects c-Myc from proteasomal degradation. ERK is, however, not alone sufficient to stabilize c-Myc but requires the cooperation of cancerous inhibitor of protein phosphatase 2A (CIP2A), an oncogene......Ras is one of the most frequently activated oncogenes in cancer. Two mitogen-activated protein kinases (MAPKs) are important for ras transformation: extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase 2 (JNK2). Here we present a downstream signal amplification cascade...

  3. c-Jun N-terminal kinase 3 expression in the retina of ocular hypertension mice: a possible target to reduce ganglion cell apoptosis

    Directory of Open Access Journals (Sweden)

    Yue He

    2015-01-01

    Full Text Available Glaucoma, a type of optic neuropathy, is characterized by the loss of retinal ganglion cells. It remains controversial whether c-Jun N-terminal kinase (JNK participates in the apoptosis of retinal ganglion cells in glaucoma. This study sought to explore a possible mechanism of action of JNK signaling pathway in glaucoma-induced retinal optic nerve damage. We established a mouse model of chronic ocular hypertension by reducing the aqueous humor followed by photocoagulation using the laser ignition method. Results showed significant pathological changes in the ocular tissues after the injury. Apoptosis of retinal ganglion cells increased with increased intraocular pressure, as did JNK3 mRNA expression in the retina. These data indicated that the increased expression of JNK3 mRNA was strongly associated with the increase in intraocular pressure in the retina, and correlated positively with the apoptosis of retinal ganglion cells.

  4. c-Jun N-terminal kinase negatively regulates epidermal growth factor-induced cyclooxygenase-2 expression in oral squamous cell carcinoma cell lines.

    Science.gov (United States)

    Husvik, Camilla; Bryne, Magne; Halstensen, Trond S

    2009-12-01

    Epidermal growth factor (EGF)-induced cyclooxygenase-2 (COX-2) expression in squamous cell carcinomas is mediated through the extracellular signal-regulated kinase 1/2 and p38 pathways. Examination of a basaloid and a conventional oral squamous cell carcinoma cell line revealed that inhibition of c-Jun N-terminal kinase (JNK) with SP600125 increased EGF-induced (but not basal) COX-2 transcription 1.5-1.9-fold in extracellular signal-regulated kinase 1/2 and p38 pathway-dependent manners. Although JNK may phosphorylate the cyclosporine A-sensitive transcription factor, nuclear factor of activated T cells c3, it was seemingly not involved because cyclosporine A did not reduce EGF-induced COX-2 expression. Thus, JNK negatively regulated EGF-induced extracellular signal-regulated kinase 1/2 and/or p38-mediated COX-2 transcription, presumably through activating an unidentified phosphatase.

  5. Differential expression of c-Jun proteins during müllerian duct growth and apoptosis: caspase-related tissue death blocked by diethylstilbestrol.

    Science.gov (United States)

    Teng, C S

    2000-12-01

    To elucidate whether the differentiation of the Müllerian duct (MD) is mediated by c-Jun proteins, Western immunoblot with c-Jun/sc-45 antibody was used to investigate these proteins in female chick left and right MDs (LMD and RMD, respectively). The content of these proteins (e.g., the 66-kDa, 45-kDa, and 39-kDa forms) in the LMD or RMD of various stages of embryos was detected by measuring their density in autoradiograms by a Spot-denso-program with Alpha Ease software. In the LMD, the growing embryonic sex tract, the content of the 66-kDa and 39-kDa proteins increased to their highest level in 9th to 12th day embryos and then declined thereafter. In the RMD, the apoptotic embryonic sex tract, the content of these proteins also showed a linear increase from the 9th to 10th day and then declined at the 13th day. When the RMD entered the apoptosis stages (14th to 18th day of incubation), these proteins were persistently overexpressed. Another protein (45 kDa) was detected in both ducts only at the 9th to 13th days, and its content was higher in RMD than in the LMD. In parallel to this finding, high caspase-3 activity (determined by the measurement of the fragmented 85-kDa poly ADP-ribose polymerase) was found in the RMD during apoptosis. The apoptotic death of RMD was prevented by in vivo diethylstilbestrol treatment, which inhibited the overexpression of the 66-kDa and 45-kDa proteins, the fragmentation of DNA, and the activity of caspase-3. No inhibitory effect was found for the 39-kDa protein.

  6. miR200c attenuates P-gp-mediated MDR and metastasis by targeting JNK2/c-Jun signaling pathway in colorectal cancer.

    Science.gov (United States)

    Sui, Hua; Cai, Guo-Xiang; Pan, Shu-Fang; Deng, Wan-Li; Wang, Yu-Wei; Chen, Zhe-Sheng; Cai, San-Jun; Zhu, Hui-Rong; Li, Qi

    2014-12-01

    MicroRNA-200c (miR200c) recently emerged as an important regulator of tumorigenicity and cancer metastasis; however, its role in regulating multidrug resistance (MDR) remains unknown. In the current study, we found that the expression levels of miR200c in recurrent and metastatic colorectal cancers were significantly lower, whereas the JNK2 expression was higher compared with primary tumors. We showed that in MDR colorectal cancer cells, miR200c targeted the 3' untranslated region of the JNK2 gene. Overexpression of miR200c attenuated the levels of p-JNK, p-c-Jun, P-gp, and MMP-2/-9, the downstream factors of the JNK signaling pathway, resulting in increased sensitivity to chemotherapeutic drugs, which was accompanied by heightened apoptosis and decreased cell invasion and migration. Moreover, in an orthotopic MDR colorectal cancer mouse model, we demonstrated that overexpression of miR200c effectively inhibited the tumor growth and metastasis. At last, in the tumor samples from patients with locally advanced colorectal cancer with routine postsurgical chemotherapy, we observed an inverse correlation between the levels of mRNA expression of miR200c and JNK2, ABCB1, and MMP-9, thus predicting patient therapeutic outcomes. In summary, we found that miR200c negatively regulated the expression of JNK2 gene and increased the sensitivity of MDR colorectal cancer cells to chemotherapeutic drugs, via inhibiting the JNK2/p-JNK/p-c-Jun/ABCB1 signaling. Restoration of miR200c expression in MDR colorectal cancer may serve as a promising therapeutic approach in MDR-induced metastasis. ©2014 American Association for Cancer Research.

  7. WNT6 promotes the migration and differentiation of human dental pulp cells partly through c-Jun N-terminal kinase signaling pathway.

    Science.gov (United States)

    Li, Ruimin; Wang, Chenglin; Tong, Juan; Su, Yingying; Lin, Yunfeng; Zhou, Xuedong; Ye, Ling

    2014-07-01

    During the dental pulp repair process, human dental pulp cells (HDPCs) migrate to injury sites where they may differentiate into odontoblastlike cells. WNT6 plays a role in dental development and can activate a noncanonical pathway including the c-Jun N-terminal kinase (JNK) pathway. The mechanism of WNT6 in dental pulp repair is still unknown. The purpose of this study was to explore the potential role of the WNT6/JNK signaling pathway in the promotion of cell migration and the differentiation of HDPCs. The third passage of HDPCs were cultured in vitro and treated with WNT6 conditioned medium with or without the pretreatment of JNK inhibitor SP600125. The activation of JNK was detected by Western blot, the expression of c-Jun was quantified by reverse-transcription polymerase chain reaction, the migration of HDPCs was determined by wound healing and transwell migration assays, and the differentiation of HDPCs was investigated using alkaline phosphatase staining and alizarin red staining. The expression of odontogenesis-related genes such as Runt-related transcription factor 2, dentin sialophosphoprotein, and dentin matrix protein 1 was quantified. WNT6 activates the JNK pathway in HDPCs and enhances cell migration, mineralization nodule formation, and alkaline phosphatase activation. WNT6 also increases the expression of Runt-related transcription factor 2, dentin sialophosphoprotein, and dentin matrix protein messenger RNA in HDPCs. Blockage of the JNK pathway in HDPCs decreases but does not completely abolish the cell migration and differentiation capacity induced by WNT6. WNT6 activates the JNK signaling pathway in HDPCs, leading to migration and differentiation. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  8. Docosahexaenoic acid downregulates phenobarbital-induced cytochrome P450 2B1 gene expression in rat primary hepatocytes via the c-Jun NH2-terminal kinase mitogen-activated protein kinase pathway.

    Science.gov (United States)

    Lu, Chia-Yang; Li, Chien-Chun; Liu, Kai-Li; Lii, Chong-Kuei; Chen, Haw-Wen

    2009-03-01

    Mitogen-activated protein kinase (MAPK) pathways play central roles in the transduction of extracellular stimuli into cells and the regulation of expression of numerous genes. Docosahexaenoic acid (DHA) was shown to be involved in the regulation of expression of drug metabolizing enzymes (DMEs) in rat primary hepatocytes in response to xenobiotics. Cytochrome P450 2B1 (CYP 2B1) is a DME that is dramatically induced by phenobarbital-type inducers. The constitutive androstane receptor (CAR) plays a critical role in regulating the expression of DMEs, and the phosphorylation/dephosphorylation of CAR is an important event in CYP 2B1 expression. In the present study, we determined the effect of DHA on MAPK transactivation and its role in CYP 2B1 expression induced by phenobarbital. c-Jun NH2-terminal kinase (JNK) JNK1/2 and ERK1/2 were activated by phenobarbital in a dose-dependent manner. DHA (100 muM) inhibited JNK1/2 and ERK2 activation induced by phenobarbital in a time-dependent manner. Both SP600125 (a JNK inhibitor) and SB203580 (a p38 MAPK inhibitor) inhibited CYP 2B1 protein and mRNA expression induced by phenobarbital. SB203580 significantly increased the intracellular 3'-5'-cyclic adenosine monophosphate (cAMP) concentration compared with a control group (p expression induced by phenobarbital.

  9. The control of histone methylation and gene expression by oxidative stress, hypoxia, and metals.

    Science.gov (United States)

    Chervona, Yana; Costa, Max

    2012-09-01

    The harmful consequences of carcinogenic metals, such as nickel, arsenic, and chromium, are thought to be in part due to their ability to induce oxidative stress. The ubiquity of oxidative stress in biological systems has made it a fairly obvious culprit in causing cellular damage and/or development of disease. However, the full extent of oxidative stress-induced damage is not limited to its direct effects on cellular components, such as lipids, proteins, and DNA, but may extend to its ability to alter gene expression. Gene expression regulation is an important component of cellular and/or tissue homeostasis, and its alteration can have detrimental consequences. Therefore, a growing amount of interest is being paid to understanding how oxidative stress can influence gene expression. Oxidative stress-induced epigenetic dysregulation in the form of posttranslational histone modifications, in particular, is a popular topic of research. This review will therefore primarily focus on discussing the role of oxidative stress and hypoxia on histone methylation and/or gene expression alterations. The sources of oxidative stress discussed here are carcinogenic metals, such as, nickel, arsenic, and chromium. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. The control of histone methylation and gene expression by oxidative stress, hypoxia and metals

    Science.gov (United States)

    Chervona, Yana; Costa, Max

    2012-01-01

    The harmful consequences of carcinogenic metals, such as nickel, arsenic and chromium, are thought to be in part due to their ability to induce oxidative stress. The ubiquity of oxidative stress in biological systems has made it a fairly obvious culprit in causing cellular damage and/or development of disease. However, the full extent of oxidative stress-induced damage is not limited to its direct effects on cellular components, such as lipids, proteins and DNA, but may extend to its ability to alter gene expression. Gene expression regulation is an important component of cellular and/or tissue homeostasis, and its alteration can have detrimental consequences. Therefore, a growing amount of interest is being paid to understanding how oxidative stress can influence gene expression. Oxidative stress-induced epigenetic dysregulation in the form of post-translational histone modifications, in particular, is a popular topic of research. This review will therefore primarily focus on discussing the role of oxidative stress and hypoxia on histone methylation and/or gene expression alterations. The sources of oxidative stress discussed here are carcinogenic metals, such as, nickel, arsenic and chromium. PMID:22841757

  11. Histone profiles in cancer.

    Science.gov (United States)

    Riedel, Simone S; Neff, Tobias; Bernt, Kathrin M

    2015-10-01

    While DNA abnormalities have long been recognized as the cause of cancer, the contribution of chromatin is a relatively recent discovery. Excitement in the field of cancer epigenetics is driven by 3 key elements: 1. Chromatin may play an active and often critical role in controlling gene expression, DNA stability and cell identity. 2. Chromatin modifiers are frequent targets of DNA aberrations, in some cancers reaching near 100%. Particularly in cancers with low rates of DNA mutations, the key "driver" of malignancy is often a chromatin modifier. 3. Cancer-associated aberrant chromatin is amenable to pharmacologic modulation. This has sparked the rapidly expanding development of small molecules targeting chromatin modifiers or reader domains, several of which have shown promise in clinical trials. In parallel, technical advances have greatly enhanced our ability to perform comprehensive chromatin/histone profiling. Despite the discovery that distinct histone profiles are associated with prognostic subgroups, and in some instances may point towards an underlying aberration that can be targeted, histone profiling has not entered clinical diagnostics. Even eligibility for clinical trials targeting chromatin hinges on traditional histologic or DNA-based molecular criteria rather than chromatin profiles. This review will give an overview of the philosophical debate around the role of histones in controlling or modulating gene expression and discuss the most common techniques for histone profiling. In addition, we will provide prominent examples of aberrantly expressed or mutated chromatin modifiers that result in either globally or locally aberrant histone profiles, and that may be promising therapeutic targets. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Histone Lysine Methylation and Neurodevelopmental Disorders

    Directory of Open Access Journals (Sweden)

    Jeong-Hoon Kim

    2017-06-01

    Full Text Available Methylation of several lysine residues of histones is a crucial mechanism for relatively long-term regulation of genomic activity. Recent molecular biological studies have demonstrated that the function of histone methylation is more diverse and complex than previously thought. Moreover, studies using newly available genomics techniques, such as exome sequencing, have identified an increasing number of histone lysine methylation-related genes as intellectual disability-associated genes, which highlights the importance of accurate control of histone methylation during neurogenesis. However, given the functional diversity and complexity of histone methylation within the cell, the study of the molecular basis of histone methylation-related neurodevelopmental disorders is currently still in its infancy. Here, we review the latest studies that revealed the pathological implications of alterations in histone methylation status in the context of various neurodevelopmental disorders and propose possible therapeutic application of epigenetic compounds regulating histone methylation status for the treatment of these diseases.

  13. Recruitment of Cln3 cyclin to promoters controls cell cycle entry via histone deacetylase and other targets.

    Directory of Open Access Journals (Sweden)

    Hongyin Wang

    2009-09-01

    Full Text Available In yeast, the G1 cyclin Cln3 promotes cell cycle entry by activating the transcription factor SBF. In mammals, there is a parallel system for cell cycle entry in which cyclin dependent kinase (CDK activates transcription factor E2F/Dp. Here we show that Cln3 regulates SBF by at least two different pathways, one involving the repressive protein Whi5, and the second involving Stb1. The Rpd3 histone deacetylase complex is also involved. Cln3 binds to SBF at the CLN2 promoter, and removes previously bound Whi5 and histone deacetylase. Adding extra copies of the SBF binding site to the cell delays Start, possibly by titrating Cln3. Since Rpd3 is the yeast ortholog of mammalian HDAC1, there is now a virtually complete analogy between the proteins regulating cell cycle entry in yeast (SBF, Cln3, Whi5 and Stb1, Rpd3 and mammals (E2F, Cyclin D, Rb, HDAC1. The cell may titrate Cln3 molecules against the number of SBF binding sites, and this could be the underlying basis of the size-control mechanism for Start.

  14. Telmisartan directly ameliorates the neuronal inflammatory response to IL-1β partly through the JNK/c-Jun and NADPH oxidase pathways

    Directory of Open Access Journals (Sweden)

    Pang Tao

    2012-05-01

    Full Text Available Abstract Background Blockade of angiotensin II type 1 (AT1 receptors ameliorates brain inflammation, and reduces excessive brain interleukin-1 beta (IL-1β production and release from cortical microglia. The aim of this study was to determine whether, in addition, AT1 receptor blockade directly attenuates IL-1β-induced inflammatory responses in neuronal cultures. Methods SK-N-SH human neuroblasts and primary rat cortical neurons were pretreated with telmisartan followed by exposure to IL-1β. Gene expression was determined by reverse transcriptase (RT-PCR, protein expression and kinase activation by western blotting, NADPH oxidase activity by the lucigenin method, prostaglandin E2 (PGE2 release by enzyme immunoassay, reactive oxygen species (ROS generation by the dichlorodihydrofluorescein diacetate fluorescent probe assay, and peroxisome proliferator-activated receptor gamma (PPARγ involvement was assessed with the antagonists GW9662 and T0070907, the agonist pioglitazone and the expression of PPARγ target genes ABCG1 and CD36. Results We found that SK-N-SH neuroblasts expressed AT1 but not AT2 receptor mRNA. Telmisartan reduced IL-1β-induced cyclooxygenase-2 (COX-2 expression and PGE2 release more potently than did candesartan and losartan. Telmisartan reduced the IL-1β-induced increase in IL-1R1 receptor and NADPH oxidase-4 (NOX-4 mRNA expression, NADPH oxidase activity, and ROS generation, and reduced hydrogen peroxide-induced COX-2 gene expression. Telmisartan did not modify IL-1β-induced ERK1/2 and p38 mitogen-activated protein kinase (MAPK phosphorylation or nuclear factor-κB activation but significantly decreased IL-1β-induced c-Jun N-terminal kinase (JNK and c-Jun activation. The JNK inhibitor SP600125 decreased IL-1β-induced PGE2 release with a potency similar to that of telmisartan. The PPARγ agonist pioglitazone reduced IL-1β-induced inflammatory reaction, whereas telmisartan did not activate PPARγ, as shown by its

  15. ATF3 expression precedes death of spinal motoneurons in amyotrophic lateral sclerosis-SOD1 transgenic mice and correlates with c-Jun phosphorylation, CHOP expression, somato-dendritic ubiquitination and Golgi fragmentation.

    Science.gov (United States)

    Vlug, Angela S; Teuling, Eva; Haasdijk, Elize D; French, Pim; Hoogenraad, Casper C; Jaarsma, Dick

    2005-10-01

    To obtain insight into the morphological and molecular correlates of motoneuron degeneration in amyotrophic lateral sclerosis (ALS) mice that express G93A mutant superoxide dismutase (SOD)1 (G93A mice), we have mapped and characterized 'sick' motoneurons labelled by the 'stress transcription factors' ATF3 and phospho-c-Jun. Immunocytochemistry and in situ hybridization showed that a subset of motoneurons express ATF3 from a relatively early phase of disease before the onset of active caspase 3 expression and motoneuron loss. The highest number of ATF3-expressing motoneurons occurred at symptom onset. The onset of ATF3 expression correlated with the appearance of ubiquitinated neurites. Confocal double-labelling immunofluorescence showed that all ATF3-positive motoneurons were immunoreactive for phosphorylated c-Jun. Furthermore, the majority of ATF3 and phospho-c-Jun-positive motoneurons were also immunoreactive for CHOP (GADD153) and showed Golgi fragmentation. A subset of ATF3 and phosphorylated c-Jun-immunoreactive motoneurons showed an abnormal appearance characterized by a number of distinctive features, including an eccentric flattened nucleus, perikaryal accumulation of ubiquitin immunoreactivity, juxta-nuclear accumulation of the Golgi apparatus and the endoplasmic reticulum, and intense Hsp70 immunoreactivity. These abnormal cells were not immunoreactive for active caspase 3. We conclude that motoneurons in ALS-SOD1 mice prior to their death and disappearance experience a prolonged sick phase, characterized by the gradual accumulation of ubiquitinated material first in the neurites and subsequently the cell body.

  16. Overexpression of ATF3 or the combination of ATF3, c-Jun, STAT3 and Smad1 promotes regeneration of the central axon branch of sensory neurons but without synergistic effects

    NARCIS (Netherlands)

    Fagoe, Nitish D; Attwell, Callan L; Kouwenhoven, Dorette; Verhaagen, J.; Mason, M.R.J.

    2015-01-01

    Peripheral nerve injury results in the activation of a number of transcription factors (TFs) in injured neurons, some of which may be key regulators of the regeneration-associated gene (RAG) programme. Among known RAG TFs, ATF3, Smad1, STAT3 and c-Jun have all been linked to successful axonal

  17. Extracellular-regulated kinase 1/2, Jun N-terminal kinase, and c-Jun are involved in NF-kappa B-dependent IL-6 expression in human monocytes

    NARCIS (Netherlands)

    Tuyt, LML; Dokter, WHA; Birbenkamp, K; Koopmans, S.B.; Lummen, C; Kruijer, W; Vellenga, E

    1999-01-01

    In the present study we investigated the possible involvement of the mitogen-activated protein kinase family members extracellular-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK) in mediating IL-6 gene expression in human monocytes, in particular their role in enhancing NF-kappa B

  18. c-Jun NH2-terminal kinase activity in subcutaneous adipose tissue but not nuclear factor-kappaB activity in peripheral blood mononuclear cells is an independent determinant of insulin resistance in healthy individuals

    DEFF Research Database (Denmark)

    Sourris, Karly C; Lyons, Jasmine G; de Courten, Maximilian

    2009-01-01

    Chronic low-grade activation of the immune system (CLAIS) predicts type 2 diabetes via a decrease in insulin sensitivity. Our study investigated potential relationships between nuclear factor-kappaB (NF-kappaB) and c-Jun NH(2)-terminal kinase (JNK) pathways-two pathways proposed as the link between...

  19. c-Jun NH2-terminal kinase 1/2 and endoplasmic reticulum stress as interdependent and reciprocal causation in diabetic embryopathy.

    Science.gov (United States)

    Li, Xuezheng; Xu, Cheng; Yang, Peixin

    2013-02-01

    Embryos exposed to high glucose exhibit aberrant maturational and cytoarchitectural cellular changes, implicating cellular organelle stress in diabetic embryopathy. c-Jun-N-terminal kinase 1/2 (JNK1/2) activation is a causal event in maternal diabetes-induced neural tube defects (NTD). However, the relationship between JNK1/2 activation and endoplasmic reticulum (ER) stress in diabetic embryopathy has never been explored. We found that maternal diabetes significantly increased ER stress markers and induced swollen/enlarged ER lumens in embryonic neuroepithelial cells during neurulation. Deletion of either jnk1 or jnk2 gene diminished hyperglycemia-increased ER stress markers and ER chaperone gene expression. In embryos cultured under high-glucose conditions (20 mmol/L), the use of 4-phenylbutyric acid (4-PBA), an ER chemical chaperone, diminished ER stress markers and abolished the activation of JNK1/2 and its downstream transcription factors, caspase 3 and caspase 8, and Sox1 neural progenitor apoptosis. Consequently, both 1 and 2 mmol/L 4-PBA significantly ameliorated high glucose-induced NTD. We conclude that hyperglycemia induces ER stress, which is responsible for the proapoptotic JNK1/2 pathway activation, apoptosis, and NTD induction. Suppressing JNK1/2 activation by either jnk1 or jnk2 gene deletion prevents ER stress. Thus, our study reveals a reciprocal causation of ER stress and JNK1/2 in mediating the teratogenicity of maternal diabetes.

  20. Activation of c-Jun NH(2)-terminal kinase is required for porcine reproductive and respiratory syndrome virus-induced apoptosis but not for virus replication.

    Science.gov (United States)

    Yin, Shutao; Huo, Yazhen; Dong, Yinhui; Fan, Lihong; Yang, Hanchun; Wang, Leyuan; Ning, Yibao; Hu, Hongbo

    2012-06-01

    Apoptosis of host cells plays a critical role in pathogenesis of virus infection. MAPK kinases especially stress-activated protein kinases c-Jun NH(2)-terminal kinase (SAPK/JNK) and p38 are often involved in virus-mediated apoptosis. It has been shown that porcine reproductive and respiratory syndrome virus (PRRSV) infection resulted in apoptosis of the host cells both in vitro and in vivo. The current investigation was initiated to determine whether stress-activated protein kinases JNK and p38 play a role in apoptosis induction by PRRSV infection. We examined phosphorylation of JNK and p38, and found that JNK but not p38 was activated in response to PRRSV infection. We then examined effects of this kinase on apoptosis induction and virus replication by using specific inhibitor. We found that JNK inhibition by its inhibitor SP600125 led to the abolishment of PRRSV-mediated apoptosis, but did not suppress virus replication. Further studies demonstrated that ROS generation was involved in JNK activation, and Bcl-2 family anti-apoptotic proteins Mcl-1 and Bcl-xl were downstream targets of JNK to mediate apoptosis. We conclude that activation of JNK signaling pathway is essential for PRRSV-mediated apoptosis but not for virus replication. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Distinct factors control histone variant H3.3 localization at specific genomic regions

    Science.gov (United States)

    Goldberg, Aaron D.; Banaszynski, Laura A.; Noh, Kyung-Min; Lewis, Peter W.; Elsaesser, Simon J.; Stadler, Sonja; Dewell, Scott; Law, Martin; Guo, Xingyi; Li, Xuan; Wen, Duancheng; Chapgier, Ariane; DeKelver, Russell C.; Miller, Jeffrey C.; Lee, Ya-Li; Boydston, Elizabeth A.; Holmes, Michael C.; Gregory, Philip D.; Greally, John M.; Rafii, Shahin; Yang, Chingwen; Scambler, Peter J.; Garrick, David; Gibbons, Richard J.; Higgs, Douglas R.; Cristea, Ileana M.; Urnov, Fyodor D.; Zheng, Deyou; Allis, C. David

    2010-01-01

    Summary The incorporation of histone H3 variants has been implicated in the epigenetic memory of cellular state. Using genome editing with zinc finger nucleases to tag endogenous H3.3, we report genome-wide profiles of H3 variants in mammalian embryonic stem (ES) cells and neuronal precursor cells. Genome-wide patterns of H3.3 are dependent on amino acid sequence, and change with cellular differentiation at developmentally regulated loci. The H3.3 chaperone Hira is required for H3.3 enrichment at active and repressed genes. Strikingly, Hira is not essential for localization of H3.3 at telomeres and many transcription factor binding sites. Immunoaffinity purification and mass spectrometry reveal that the proteins Atrx and Daxx associate with H3.3 in a Hira-independent manner. Atrx is required for Hira-independent localization of H3.3 at telomeres, and for the repression of telomeric RNA. Our data demonstrate that multiple and distinct factors are responsible for H3.3 localization at specific genomic locations in mammalian cells. PMID:20211137

  2. Molecular mechanisms and potential functions of histone demethylases

    DEFF Research Database (Denmark)

    Kooistra, Susanne Marije; Helin, Kristian

    2012-01-01

    Histone modifications are thought to regulate chromatin structure, transcription and other nuclear processes. Histone methylation was originally believed to be an irreversible modification that could only be removed by histone eviction or by dilution during DNA replication. However, the isolation...... of two families of enzymes that can demethylate histones has changed this notion. The biochemical activities of these histone demethylases towards specific Lys residues on histones, and in some cases non-histone substrates, have highlighted their importance in developmental control, cell-fate decisions...

  3. The histone deacetylases sir2 and rpd3 act on ribosomal DNA to control the replication program in budding yeast.

    Science.gov (United States)

    Yoshida, Kazumasa; Bacal, Julien; Desmarais, Damien; Padioleau, Ismaël; Tsaponina, Olga; Chabes, Andrei; Pantesco, Véronique; Dubois, Emeric; Parrinello, Hugues; Skrzypczak, Magdalena; Ginalski, Krzysztof; Lengronne, Armelle; Pasero, Philippe

    2014-05-22

    In S. cerevisiae, replication timing is controlled by epigenetic mechanisms restricting the accessibility of origins to limiting initiation factors. About 30% of these origins are located within repetitive DNA sequences such as the ribosomal DNA (rDNA) array, but their regulation is poorly understood. Here, we have investigated how histone deacetylases (HDACs) control the replication program in budding yeast. This analysis revealed that two HDACs, Rpd3 and Sir2, control replication timing in an opposite manner. Whereas Rpd3 delays initiation at late origins, Sir2 is required for the timely activation of early origins. Moreover, Sir2 represses initiation at rDNA origins, whereas Rpd3 counteracts this effect. Remarkably, deletion of SIR2 restored normal replication in rpd3Δ cells by reactivating rDNA origins. Together, these data indicate that HDACs control the replication timing program in budding yeast by modulating the ability of repeated origins to compete with single-copy origins for limiting initiation factors. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Exercise training protects against atherosclerotic risk factors through vascular NADPH oxidase, extracellular signal-regulated kinase 1/2 and stress-activated protein kinase/c-Jun N-terminal kinase downregulation in obese rats.

    Science.gov (United States)

    Touati, Sabeur; Montezano, Augusto C I; Meziri, Fayçal; Riva, Catherine; Touyz, Rhian M; Laurant, Pascal

    2015-02-01

    Exercise training reverses atherosclerotic risk factors associated with metabolic syndrome and obesity. The aim of the present study was to determine the molecular anti-inflammatory, anti-oxidative and anti-atherogenic effects in aorta from rats with high-fat diet-induced obesity. Male Sprague-Dawley rats were placed on a high-fat (HFD) or control (CD) diet for 12 weeks. The HFD rats were then divided into four groups: (i) sedentary HFD-fed rats (HFD-S); (ii) exercise trained (motor treadmill 5 days/week, 60 min/day, 12 weeks) HFD-fed rats (HFD-Ex); (iii) modified diet (HFD to CD) sedentary rats (HF/CD-S); and (iv) an exercise-trained modified diet group (HF/CD-Ex). Tissue levels of NADPH oxidase (activity and expression), NADPH oxidase (Nox) 1, Nox2, Nox4, p47(phox) , superoxide dismutase (SOD)-1, angiotensin AT1 and AT2 receptors, phosphorylated mitogen-activated protein kinase (MAPK; extracellular signal-regulated kinase (ERK) 1/2, stress-activated protein kinase (SAPK)/c-Jun N-terminal kinase (JNK)) and vascular cell adhesion molecule-1 (VCAM-1) were determined in the aorta. Plasma cytokines (tumour necrosis factor (TNF)-α and interleukin (IL)-6) levels were also measured. Obesity was accompanied by increases in NADPH oxidase activity, p47(phox) translocation, Nox4 and VCAM-1 protein expression, MAPK (ERK1/2, SAPK/JNK) phosphorylation and plasma TNF-α and IL-6 levels. Exercise training and switching from the HFD to CD reversed almost all these molecular changes. In addition, training increased aortic SOD-1 protein expression and decreased ERK1/2 phosphorylation. These findings suggest that protective effects of exercise training on atherosclerotic risk factors induced by obesity are associated with downregulation of NADPH oxidase, ERK1/2 and SAPK/JNK activity and increased SOD-1 expression. © 2014 Wiley Publishing Asia Pty Ltd.

  5. A Novel Dual NO-donating Oxime and c-Jun N-terminal Kinase Inhibitor Protects Against Cerebral Ischemia–Reperfusion Injury in Mice

    Science.gov (United States)

    Atochin, Dmitriy N.; Schepetkin, Igor A.; Khlebnikov, Andrei I.; Seledtsov, Victor I.; Swanson, Helen; Quinn, Mark T.; Huang, Paul L.

    2017-01-01

    The c-Jun N-terminal kinase (JNK) has been shown to be an important regulator of neuronal cell death. Previously, we synthesized the sodium salt of 11H-indeno[1,2-b]quinoxalin-11-one (IQ-1S) and demonstrated that it was a high-affinity inhibitor of the JNK family. In the present work, we found that IQ-1S could release nitric oxide (NO) during its enzymatic metabolism by liver microsomes. Moreover, serum nitrite/nitrate concentration in mice increased after intraperitoneal injection of IQ-1S. Because of these dual actions as JNK inhibitor and NO-donor, the therapeutic potential of IQ-1S was evaluated in an animal stroke model. We subjected wild-type C57BL6 mice to focal ischemia (30 minutes) with subsequent reperfusion (48 hours). Mice were treated with IQ-1S (25 mg/kg) suspended in 10% solutol or with vehicle alone 30 minutes before and 24 hours after middle cerebral artery MCA) occlusion (MCAO). Using laser-Doppler flowmetry, we monitored cerebral blood flow (CBF) above the MCA during 30 minutes of MCAO provoked by a filament and during the first 30 minutes of subsequent reperfusion. In mice treated with IQ-1S, ischemic and reperfusion values of CBF were not different from vehicle-treated mice. However, IQ-1S treated mice demonstrated markedly reduced neurological deficit and infarct volumes as compared with vehicle-treated mice after 48 hours of reperfusion. Our results indicate that the novel JNK inhibitor releases NO during its oxidoreductive bioconversion and improves stroke outcome in a mouse model of cerebral reperfusion. We conclude that IQ-1S is a promising dual functional agent for the treatment of cerebral ischemia and reperfusion injury. PMID:26923672

  6. Protein kinase B/Akt activates c-Jun NH(2)-terminal kinase by increasing NO production in response to shear stress

    Science.gov (United States)

    Go, Y. M.; Boo, Y. C.; Park, H.; Maland, M. C.; Patel, R.; Pritchard, K. A. Jr; Fujio, Y.; Walsh, K.; Darley-Usmar, V.; Jo, H.

    2001-01-01

    Laminar shear stress activates c-Jun NH(2)-terminal kinase (JNK) by the mechanisms involving both nitric oxide (NO) and phosphatidylinositide 3-kinase (PI3K). Because protein kinase B (Akt), a downstream effector of PI3K, has been shown to phosphorylate and activate endothelial NO synthase, we hypothesized that Akt regulates shear-dependent activation of JNK by stimulating NO production. Here, we examined the role of Akt in shear-dependent NO production and JNK activation by expressing a dominant negative Akt mutant (Akt(AA)) and a constitutively active mutant (Akt(Myr)) in bovine aortic endothelial cells (BAEC). As expected, pretreatment of BAEC with the PI3K inhibitor (wortmannin) prevented shear-dependent stimulation of Akt and NO production. Transient expression of Akt(AA) in BAEC by using a recombinant adenoviral construct inhibited the shear-dependent stimulation of NO production and JNK activation. However, transient expression of Akt(Myr) by using a recombinant adenoviral construct did not induce JNK activation. This is consistent with our previous finding that NO is required, but not sufficient on its own, to activate JNK in response to shear stress. These results and our previous findings strongly suggest that shear stress triggers activation of PI3K, Akt, and endothelial NO synthase, leading to production of NO, which (along with O(2-), which is also produced by shear) activates Ras-JNK pathway. The regulation of Akt, NO, and JNK by shear stress is likely to play a critical role in its antiatherogenic effects.

  7. Inhibition of spinal astrocytic c-Jun N-terminal kinase (JNK activation correlates with the analgesic effects of ketamine in neuropathic pain

    Directory of Open Access Journals (Sweden)

    Wang Wen

    2011-01-01

    Full Text Available Abstract Background We have previously reported that inhibition of astrocytic activation contributes to the analgesic effects of intrathecal ketamine on spinal nerve ligation (SNL-induced neuropathic pain. However, the underlying mechanisms are still unclear. c-Jun N-terminal kinase (JNK, a member of mitogen-activated protein kinase (MAPK family, has been reported to be critical for spinal astrocytic activation and neuropathic pain development after SNL. Ketamine can decrease lipopolysaccharide (LPS-induced phosphorylated JNK (pJNK expression and could thus exert its anti-inflammatory effect. We hypothesized that inhibition of astrocytic JNK activation might be involved in the suppressive effect of ketamine on SNL-induced spinal astrocytic activation. Methods Immunofluorescence histochemical staining was used to detect SNL-induced spinal pJNK expression and localization. The effects of ketamine on SNL-induced mechanical allodynia were confirmed by behavioral testing. Immunofluorescence histochemistry and Western blot were used to quantify the SNL-induced spinal pJNK expression after ketamine administration. Results The present study showed that SNL induced ipsilateral pJNK up-regulation in astrocytes but not microglia or neurons within the spinal dorsal horn. Intrathecal ketamine relieved SNL-induced mechanical allodynia without interfering with motor performance. Additionally, intrathecal administration of ketamine attenuated SNL-induced spinal astrocytic JNK activation in a dose-dependent manner, but not JNK protein expression. Conclusions The present results suggest that inhibition of JNK activation may be involved in the suppressive effects of ketamine on SNL-induced spinal astrocyte activation. Therefore, inhibition of spinal JNK activation may be involved in the analgesic effects of ketamine on SNL-induced neuropathic pain.

  8. Activation of c-Jun N-terminal kinase is essential for mitochondrial membrane potential change and apoptosis induced by doxycycline in melanoma cells

    Science.gov (United States)

    Shieh, Jiunn-Min; Huang, Tur-Fu; Hung, Chi-Feng; Chou, Kuan-Hsien; Tsai, Yih-Jeng; Wu, Wen-Bin

    2010-01-01

    Background and purpose: Tetracyclines were recently found to induce tumour cell death, but the early processes involved in this cytotoxic effect remain unclear. Experimental approach: Viability of human and mouse melanoma cells was determined by MTT assay and flow cytometry. Kinase/protein/caspase activation was measured by Western blotting and mitochondrial membrane potential (ΔΨm) was analyzed by fluorescence microscopy and flow cytometry. Key results: Human and mouse melanoma cells were treated with doxycycline or minocycline but only doxycycline was cytotoxic. This cell death (apoptosis) in A2058 cells involved activation of caspase-3, -7 and -9 and contributed to inhibition, by doxycycline, of matrix metalloproteinase (MMP) activity and migration of these cells. Doxycycline induced intra-cellular reactive oxygen species (ROS) production, apoptosis signal-regulated kinase 1 (ASK1), c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) activation at an early stage of treatment and induced mitochondrial cytochrome c release into cytosol and ΔΨm change during apoptosis. The JNK inhibitor/small interference RNA inhibited doxycycline-induced JNK activation, ΔΨm change and apoptosis, but did not affect ASK1 activation, suggesting a role of ASK1 for JNK activation in melanoma cell apoptosis. Two ROS scavengers reduced doxycycline-induced JNK and caspase activation, and apoptosis. Taken together, the results suggest the involvement of a ROS-ASK1-JNK pathway in doxycycline-induced melanoma cell apoptosis. Conclusions and implications: We have shown a promising cytotoxic effect of doxycycline on melanoma cells, have identified ROS and ASK1 as the possible initiators and have demonstrated that JNK activation is necessary for doxycycline-induced melanoma cell apoptosis. PMID:20590610

  9. Antcin H Protects Against Acute Liver Injury Through Disruption of the Interaction of c-Jun-N-Terminal Kinase with Mitochondria.

    Science.gov (United States)

    Huo, Yazhen; Win, Sanda; Than, Tin Aung; Yin, Shutao; Ye, Min; Hu, Hongbo; Kaplowitz, Neil

    2017-02-10

    Antrodia Camphorate (AC) is a mushroom that is widely used in Asian countries to prevent and treat various diseases, including liver diseases. However, the active ingredients that contribute to the biological functions remain elusive. The purpose of the present study is to test the hepatoprotective effect of Antcin H, a major triterpenoid chemical isolated from AC, in murine models of acute liver injury. We found that Antcin H pretreatment protected against liver injury in both acetaminophen (APAP) and galactosamine/tumor necrosis factor (TNF)α models. More importantly, Antcin H also offered a significant protection against acetaminophen-induced liver injury when it was given 1 h after acetaminophen. The protection was verified in primary mouse hepatocytes. Antcin H prevented sustained c-Jun-N-terminal kinase (JNK) activation in both models. We excluded an effect of Antcin H on acetaminophen metabolism and TNF receptor signaling and excluded a direct effect as a free radical scavenger or JNK inhibitor. Since the sustained JNK activation through its interaction with mitochondrial Sab, leading to increased mitochondrial reactive oxygen species (ROS), is pivotal in both models, we examined the effect of Antcin H on p-JNK binding to mitochondria and impairment of mitochondrial respiration. Antcin H inhibited the direct effect of p-JNK on isolated mitochondrial function and binding to isolated mitochondria. Innovation and Conclusion: Our study has identified Antcin H as a novel active ingredient that contributes to the hepatoprotective effect of AC, and Antcin H protects against liver injury through disruption of the binding of p-JNK to Sab, which interferes with the ROS-dependent self-sustaining activation of MAPK cascade. Antioxid. Redox Signal. 26, 207-220.

  10. Rhinovirus infection causes steroid resistance in airway epithelium through nuclear factor κB and c-Jun N-terminal kinase activation.

    Science.gov (United States)

    Papi, Alberto; Contoli, Marco; Adcock, Ian M; Bellettato, Cinzia; Padovani, Anna; Casolari, Paolo; Stanciu, Luminita A; Barnes, Peter J; Johnston, Sebastian L; Ito, Kazuhiro; Caramori, Gaetano

    2013-11-01

    Although inhaled glucocorticoids are the mainstays of asthma treatment, they are poorly effective at treating and preventing virus-induced asthma exacerbations. The major viruses precipitating asthma exacerbations are rhinoviruses. We sought to evaluate whether rhinovirus infection interferes with the mechanisms of action of glucocorticoids. Cultured primary human bronchial or transformed (A549) respiratory epithelial cells were infected with rhinovirus 16 (RV-16) before dexamethasone exposure. Glucocorticoid receptor (GR) α nuclear translocation, glucocorticoid response element (GRE) binding, and transactivation/transrepression functional readouts were evaluated by using immunocytochemistry, Western blotting, DNA binding assays, real-time quantitative PCR, coimmunoprecipitation, and ELISA techniques. Specific inhibitors of c-Jun N-terminal kinase (JNK) and of IκB kinase (IKK) were used to investigate the involvement of intracellular signaling pathways. RV-16 infection impaired dexamethasone-dependent (1) inhibition of IL-1β-induced CXCL8 release, (2) induction of mitogen-activated protein kinase phosphatase 1 gene expression, and (3) binding of GR to GREs in airway epithelial cells. This was associated with impaired GRα nuclear translocation, as assessed by means of both immunochemistry (54.0% ± 6.8% vs 24.7% ± 3.8% GR-positive nuclei after 10 nmol/L dexamethasone treatment in sham- or RV-16-infected cells, respectively; P rhinovirus-infected cells the combination of JNK and IKK2 inhibitors totally restored dexamethasone suppression of CXCL8 release, induction of mitogen-activated protein kinase phosphatase 1 gene expression, and GRα nuclear translocation. RV-16 infection of human airway epithelium induces glucocorticoid resistance. Inhibition of RV-16-induced JNK and nuclear factor κB activation fully reversed rhinovirus impairment of both GRα nuclear translocation and the transactivation/transrepression activities of glucocorticoids. Copyright © 2013

  11. Resveratrol reduces prostaglandin E1-stimulated osteoprotegerin synthesis in osteoblasts: suppression of stress-activated protein kinase/c-Jun N-terminal kinase.

    Science.gov (United States)

    Yamamoto, Naohiro; Otsuka, Takanobu; Kuroyanagi, Gen; Kondo, Akira; Kainuma, Shingo; Nakakami, Akira; Matsushima-Nishiwaki, Rie; Kozawa, Osamu; Tokuda, Haruhiko

    2015-01-01

    Resveratrol, a natural polyphenol mainly existing in red grapes and berries, possesses beneficial effects on human being. We have previously reported that prostaglandin E1 (PGE1) stimulates vascular endothelial growth factor synthesis via activation of p38 mitogen-activated protein (MAP) kinase and stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) but not p44/p42 MAP kinase in osteoblast-like MC3T3-E1 cells. In the present study, we investigated the PGE1-effect on osteoprotegerin (OPG) synthesis and the effect of resveratrol on the synthesis in MC3T3-E1 cells. PGE1 induced the expression levels of OPG mRNA and stimulated the OPG release. Resveratrol significantly reduced the PGE1-induced OPG release and the mRNA expression. SRT1720, an activator of SIRT1, suppressed the release of OPG. The protein levels of SIRT1 were not up-regulated by resveratrol with or without PGE1. Both SB203580 and SP600125, a specific p38 MAP kinase inhibitor and a specific SAPK/JNK inhibitor, respectively, but not PD98059, a specific MEK inhibitor, reduced the PGE1-stimulated OPG release. Resveratrol or SRT1720 failed to affect the phosphorylation of p38 MAP kinase. On the contrary, PGE1-induced phosphorylation of SAPK/JNK was significantly attenuated by both resveratrol and SRT1720. Our results strongly suggest that resveratrol inhibits PGE1-stimulated OPG synthesis via suppressing SAPK/JNK but not p38 MAP kinase in osteoblasts. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. The Hos2 Histone Deacetylase Controls Ustilago maydis Virulence through Direct Regulation of Mating-Type Genes.

    Directory of Open Access Journals (Sweden)

    Alberto Elías-Villalobos

    2015-08-01

    Full Text Available Morphological changes are critical for host colonisation in plant pathogenic fungi. These changes occur at specific stages of their pathogenic cycle in response to environmental signals and are mediated by transcription factors, which act as master regulators. Histone deacetylases (HDACs play crucial roles in regulating gene expression, for example by locally modulating the accessibility of chromatin to transcriptional regulators. It has been reported that HDACs play important roles in the virulence of plant fungi. However, the specific environment-sensing pathways that control fungal virulence via HDACs remain poorly characterised. Here we address this question using the maize pathogen Ustilago maydis. We find that the HDAC Hos2 is required for the dimorphic switch and pathogenic development in U. maydis. The deletion of hos2 abolishes the cAMP-dependent expression of mating type genes. Moreover, ChIP experiments detect Hos2 binding to the gene bodies of mating-type genes, which increases in proportion to their expression level following cAMP addition. These observations suggest that Hos2 acts as a downstream component of the cAMP-PKA pathway to control the expression of mating-type genes. Interestingly, we found that Clr3, another HDAC present in U. maydis, also contributes to the cAMP-dependent regulation of mating-type gene expression, demonstrating that Hos2 is not the only HDAC involved in this control system. Overall, our results provide new insights into the role of HDACs in fungal phytopathogenesis.

  13. The Hos2 Histone Deacetylase Controls Ustilago maydis Virulence through Direct Regulation of Mating-Type Genes.

    Science.gov (United States)

    Elías-Villalobos, Alberto; Fernández-Álvarez, Alfonso; Moreno-Sánchez, Ismael; Helmlinger, Dominique; Ibeas, José I

    2015-08-01

    Morphological changes are critical for host colonisation in plant pathogenic fungi. These changes occur at specific stages of their pathogenic cycle in response to environmental signals and are mediated by transcription factors, which act as master regulators. Histone deacetylases (HDACs) play crucial roles in regulating gene expression, for example by locally modulating the accessibility of chromatin to transcriptional regulators. It has been reported that HDACs play important roles in the virulence of plant fungi. However, the specific environment-sensing pathways that control fungal virulence via HDACs remain poorly characterised. Here we address this question using the maize pathogen Ustilago maydis. We find that the HDAC Hos2 is required for the dimorphic switch and pathogenic development in U. maydis. The deletion of hos2 abolishes the cAMP-dependent expression of mating type genes. Moreover, ChIP experiments detect Hos2 binding to the gene bodies of mating-type genes, which increases in proportion to their expression level following cAMP addition. These observations suggest that Hos2 acts as a downstream component of the cAMP-PKA pathway to control the expression of mating-type genes. Interestingly, we found that Clr3, another HDAC present in U. maydis, also contributes to the cAMP-dependent regulation of mating-type gene expression, demonstrating that Hos2 is not the only HDAC involved in this control system. Overall, our results provide new insights into the role of HDACs in fungal phytopathogenesis.

  14. Specific histone modifications play critical roles in the control of encystation and antigenic variation in the early-branching eukaryote Giardia lamblia.

    Science.gov (United States)

    Carranza, Pedro G; Gargantini, Pablo R; Prucca, César G; Torri, Alessandro; Saura, Alicia; Svärd, Staffan; Lujan, Hugo D

    2016-12-01

    During evolution, parasitic microorganisms have faced the challenges of adapting to different environments to colonize a variety of hosts. Giardia lamblia, a common cause of intestinal disease, has developed fascinating strategies to adapt both outside and inside its host's intestine, such as trophozoite differentiation into cyst and the switching of its major surface antigens. How gene expression is regulated during these adaptive processes remains undefined. Giardia lacks some typical eukaryotic features, like canonical transcription factors, linker histone H1, and complex promoter regions; suggesting that post-transcriptional and translational control of gene expression is essential for parasite survival. However, epigenetic factors may also play critical roles at the transcriptional level. Here, we describe the most common post-translational histone modifications; characterize enzymes involved in these reactions, and analyze their association with the Giardia's differentiation processes. We present evidence that NAD+-dependent and NAD+-independent histone deacetylases regulate encystation; however, a unique NAD+-independent histone deacetylase modulate antigenic switching. The rates of acetylation of H4K8 and H4K16 are critical for encystation, whereas a decrease in acetylation of H4K8 and methylation of H3K9 occur preferentially during antigenic variation. These results show the complexity of the mechanisms regulating gene expression in this minimalistic protozoan parasite. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Vaccination with Leishmania infantum acidic ribosomal P0 but not with nucleosomal histones proteins controls Leishmania infantum infection in hamsters.

    Science.gov (United States)

    Pereira, Lais; Abbehusen, Melissa; Teixeira, Clarissa; Cunha, Jurema; Nascimento, Ivan P; Fukutani, Kyioshi; dos-Santos, Washington; Barral, Aldina; de Oliveira, Camila Indiani; Barral-Netto, Manoel; Soto, Manoel; Brodskyn, Cláudia Ida

    2015-02-01

    Several intracellular Leishmania antigens have been identified in order to find a potential vaccine capable of conferring long lasting protection against Leishmania infection. Histones and Acid Ribosomal proteins are already known to induce an effective immune response and have successfully been tested in the cutaneous leishmaniasis mouse model. Here, we investigate the protective ability of L. infantum nucleosomal histones (HIS) and ribosomal acidic protein P0 (LiP0) against L. infantum infection in the hamster model of visceral leishmaniasis using two different strategies: homologous (plasmid DNA only) or heterologous immunization (plasmid DNA plus recombinant protein and adjuvant). Immunization with both antigens using the heterologous strategy presented a high antibody production level while the homologous strategy immunized group showed predominantly a cellular immune response with parasite load reduction. The pcDNA-LiP0 immunized group showed increased expression ratio of IFN-γ/IL-10 and IFN-γ/TGF-β in the lymph nodes before challenge. Two months after infection hamsters immunized with the empty plasmid presented a pro-inflammatory immune response in the early stages of infection with increased expression ratio of IFN-γ/IL-10 and IFN-γ/TGF-β, whereas hamsters immunized with pcDNA-HIS presented an increase only in the ratio IFN-γ/ TGF-β. On the other hand, hamsters immunized with LiP0 did not present any increase in the IFN-γ/TGF-β and IFN-γ/IL-10 ratio independently of the immunization strategy used. Conversely, five months after infection, hamsters immunized with HIS maintained a pro-inflammatory immune response (ratio IFN-γ/ IL-10) while pcDNA-LiP0 immunized hamsters continued showing a balanced cytokine profile of pro and anti-inflammatory cytokines. Moreover we observed a significant reduction in parasite load in the spleen, liver and lymph node in this group compared with controls. Our results suggest that vaccination with L. infantum LiP0

  16. In vivo crypt surface hyperproliferation is decreased by butyrate and increased by deoxycholate in normal rat colon: associated in vivo effects on c-Fos and c-Jun expression.

    Science.gov (United States)

    Velázquez, O C; Zhou, D; Seto, R W; Jabbar, A; Choi, J; Lederer, H M; Rombeau, J L

    1996-01-01

    Studies on colon carcinogenesis suggest that the short-chain fatty acid butyrate may be protective, whereas the secondary bile acid deoxycholate may promote tumor development. Crypt surface hyperproliferation is regarded as a biomarker of colon cancer risk and can be modulated in vitro by the differentiation inducer butyrate and the tumor promoter deoxycholate. We hypothesized that butyrate decreases and deoxycholate increases crypt surface proliferation in vivo and that these effects are mediated by changes in the expression of the protooncogenes c-Fos and c-Jun, which are known to regulate proliferation and differentiation. Twenty-five adult Sprague-Dawley rats underwent colonic isolation and 24-hour intraluminal instillation of 10 mmol/L sodium chloride, 10 mmol/ L sodium butyrate, or 10 mmol/L sodium deoxycholate. Proliferation of the whole crypt and five crypt compartments from base to surface was assessed by proliferating cell nuclear antigen immunohistochemistry. The øh value, an index of "premalignant" hyperproliferation, was calculated as the ratio of labeled cells in the two surface compartments divided by the labeled cells in the entire crypt. Expression of c-Fos and c-Jun was evaluated by Western blot. Crypt surface proliferation and the øh value were significantly decreased by butyrate and increased by deoxycholate. Butyrate increased colonic expression of c-Jun, whereas deoxycholate significantly induced c-Fos. The in vivo effects on surface proliferation are consistent with a potential protective [corrected] role for butyrate and a promotive role for deoxycholate in colon carcinogenesis. The concurrently observed effects on colonic c-Jun and c-Fos expression represent a novel finding and suggest that direct or indirect modulation of protooncogene expression may be the mechanism by which these dietary byproducts regulate proliferation in vivo.

  17. An Autoregulatory Mechanism Imposes Allosteric Control on the V(DJ Recombinase by Histone H3 Methylation

    Directory of Open Access Journals (Sweden)

    Chao Lu

    2015-01-01

    Full Text Available V(DJ recombination is initiated by a specialized transposase consisting of the subunits RAG-1 and RAG-2. The susceptibility of gene segments to DNA cleavage by the V(DJ recombinase is correlated with epigenetic modifications characteristic of active chromatin, including trimethylation of histone H3 on lysine 4 (H3K4me3. Engagement of H3K4me3 by a plant homeodomain (PHD in RAG-2 promotes recombination in vivo and stimulates DNA cleavage by RAG in vitro. We now show that H3K4me3 acts allosterically at the PHD finger to relieve autoinhibition imposed by a separate domain within RAG-2. Disruption of this autoinhibitory domain was associated with constitutive increases in recombination frequency, DNA cleavage activity, substrate binding affinity, and catalytic rate, thus mimicking the stimulatory effects of H3K4me3. Our observations support a model in which allosteric control of RAG is enforced by an autoinhibitory domain whose action is relieved by engagement of active chromatin.

  18. The Candida albicans HIR histone chaperone regulates the yeast-to-hyphae transition by controlling the sensitivity to morphogenesis signals.

    Science.gov (United States)

    Jenull, Sabrina; Tscherner, Michael; Gulati, Megha; Nobile, Clarissa J; Chauhan, Neeraj; Kuchler, Karl

    2017-08-16

    Morphological plasticity such as the yeast-to-hyphae transition is a key virulence factor of the human fungal pathogen Candida albicans. Hyphal formation is controlled by a multilayer regulatory network composed of environmental sensing, signaling, transcriptional modulators as well as chromatin modifications. Here, we demonstrate a novel role for the replication-independent HIR histone chaperone complex in fungal morphogenesis. HIR operates as a crucial modulator of hyphal development, since genetic ablation of the HIR complex subunit Hir1 decreases sensitivity to morphogenetic stimuli. Strikingly, HIR1-deficient cells display altered transcriptional amplitudes upon hyphal initiation, suggesting that Hir1 affects transcription by establishing transcriptional thresholds required for driving morphogenetic cell-fate decisions. Furthermore, ectopic expression of the transcription factor Ume6, which facilitates hyphal maintenance, rescues filamentation defects of hir1Δ/Δ cells, suggesting that Hir1 impacts the early phase of hyphal initiation. Hence, chromatin chaperone-mediated fine-tuning of transcription is crucial for driving morphogenetic conversions in the fungal pathogen C. albicans.

  19. The gap junction inhibitor 2-aminoethoxy-diphenyl-borate protects against acetaminophen hepatotoxicity by inhibiting cytochrome P450 enzymes and c-jun N-terminal kinase activation

    Energy Technology Data Exchange (ETDEWEB)

    Du, Kuo; Williams, C. David; McGill, Mitchell R.; Xie, Yuchao [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Farhood, Anwar [Department of Pathology, St. David' s North Austin Medical Center, Austin, TX 78756 (United States); Vinken, Mathieu [Department of Toxicology, Center for Pharmaceutical Sciences, Vrije Universiteit Brussels, 1090 Brussels (Belgium); Jaeschke, Hartmut, E-mail: hjaeschke@kumc.edu [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States)

    2013-12-15

    Acetaminophen (APAP) hepatotoxicity is the leading cause of acute liver failure in the US. Although many aspects of the mechanism are known, recent publications suggest that gap junctions composed of connexin32 function as critical intercellular communication channels which transfer cytotoxic mediators into neighboring hepatocytes and aggravate liver injury. However, these studies did not consider off-target effects of reagents used in these experiments, especially the gap junction inhibitor 2-aminoethoxy-diphenyl-borate (2-APB). In order to assess the mechanisms of protection of 2-APB in vivo, male C56Bl/6 mice were treated with 400 mg/kg APAP to cause extensive liver injury. This injury was prevented when animals were co-treated with 20 mg/kg 2-APB and was attenuated when 2-APB was administered 1.5 h after APAP. However, the protection was completely lost when 2-APB was given 4–6 h after APAP. Measurement of protein adducts and c-jun-N-terminal kinase (JNK) activation indicated that 2-APB reduced both protein binding and JNK activation, which correlated with hepatoprotection. Although some of the protection was due to the solvent dimethyl sulfoxide (DMSO), in vitro experiments clearly demonstrated that 2-APB directly inhibits cytochrome P450 activities. In addition, JNK activation induced by phorone and tert-butylhydroperoxide in vivo was inhibited by 2-APB. The effects against APAP toxicity in vivo were reproduced in primary cultured hepatocytes without use of DMSO and in the absence of functional gap junctions. We conclude that the protective effect of 2-APB was caused by inhibition of metabolic activation of APAP and inhibition of the JNK signaling pathway and not by blocking connexin32-based gap junctions. - Highlights: • 2-APB protected against APAP-induced liver injury in mice in vivo and in vitro • 2-APB protected by inhibiting APAP metabolic activation and JNK signaling pathway • DMSO inhibited APAP metabolic activation as the solvent of 2-APB

  20. The c-Fos and c-Jun from Litopenaeus vannamei play opposite roles in Vibrio parahaemolyticus and white spot syndrome virus infection.

    Science.gov (United States)

    Li, Chaozheng; Li, Haoyang; Wang, Sheng; Song, Xuan; Zhang, Zijian; Qian, Zhe; Zuo, Hongliang; Xu, Xiaopeng; Weng, Shaoping; He, Jianguo

    2015-09-01

    Growing evidence indicates that activator protein-1 (AP-1) plays a major role in stimulating the transcription of immune effector molecules in cellular response to an incredible array of stimuli, including growth factors, cytokines, cellular stresses and bacterial and viral infection. Here, we reported the isolation and characterization of a cDNA from Litopenaeus vannamei encoding the full-length c-Fos protein (named as Lvc-Fos). The predicted amino acid sequences of Lvc-Fos contained a basic-leucine zipper (bZIP) domain, which was characteristic of members of the AP-1 family. Immunoprecipitation and native-PAGE assays determined that Lvc-Fos could interact with the Lvc-Jun, a homolog of c-Jun family in L. vannamei, in a heterodimer manner. Further investigation demonstrated that Lvc-Fos and Lvc-Jun were expressed in all tested tissues and located in the nucleus. Real-time RT-PCR analysis showed both Lvc-Fos and Lvc-Jun in gills were up-regulated during Vibrio parahaemolyticus and white spot syndrome virus (WSSV) challenges. In addition, reporter gene assays indicated Lvc-Fos and Lvc-Jun could activate the expression of antimicrobial peptides (AMPs) of Drosophila and shrimp, as well as WSSV immediate early (IE) genes wsv069 and wsv249, in a different manner. Knockdown of Lvc-Fos or Lvc-Jun by RNA interference (RNAi) resulted in higher mortalities of L. vannamei after infection with V. parahaemolyticus, suggesting that Lvc-Fos and Lvc-Jun might play protective roles in bacterial infection. However, silencing of Lvc-Fos or Lvc-Jun in shrimp caused lower mortalities and virus loads under WSSV infection, suggesting that Lvc-Fos and Lvc-Jun could be engaged for WSSV replication and pathogenesis. In conclusion, our results provided experimental evidence and novel insight into the roles of L. vannamei AP-1 in bacterial and viral infection. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Lower susceptibility of female mice to acetaminophen hepatotoxicity: Role of mitochondrial glutathione, oxidant stress and c-jun N-terminal kinase

    Energy Technology Data Exchange (ETDEWEB)

    Du, Kuo; Williams, C. David; McGill, Mitchell R.; Jaeschke, Hartmut, E-mail: hjaeschke@kumc.edu

    2014-11-15

    Acetaminophen (APAP) overdose causes severe hepatotoxicity in animals and humans. However, the mechanisms underlying the gender differences in susceptibility to APAP overdose in mice have not been clarified. In our study, APAP (300 mg/kg) caused severe liver injury in male mice but 69–77% lower injury in females. No gender difference in metabolic activation of APAP was found. Hepatic glutathione (GSH) was rapidly depleted in both genders, while GSH recovery in female mice was 2.6 fold higher in the mitochondria at 4 h, and 2.5 and 3.3 fold higher in the total liver at 4 h and 6 h, respectively. This faster recovery of GSH, which correlated with greater induction of glutamate-cysteine ligase, attenuated mitochondrial oxidative stress in female mice, as suggested by a lower GSSG/GSH ratio at 6 h (3.8% in males vs. 1.4% in females) and minimal centrilobular nitrotyrosine staining. While c-jun N-terminal kinase (JNK) activation was similar at 2 and 4 h post-APAP, it was 3.1 fold lower at 6 h in female mice. However, female mice were still protected by the JNK inhibitor SP600125. 17β-Estradiol pretreatment moderately decreased liver injury and oxidative stress in male mice without affecting GSH recovery. Conclusion: The lower susceptibility of female mice is achieved by the improved detoxification of reactive oxygen due to accelerated recovery of mitochondrial GSH levels, which attenuates late JNK activation and liver injury. However, even the reduced injury in female mice was still dependent on JNK. While 17β-estradiol partially protects male mice, it does not affect hepatic GSH recovery. - Highlights: • Female mice are less susceptible to acetaminophen overdose than males. • GSH depletion and protein adduct formation are similar in both genders. • Recovery of hepatic GSH levels is faster in females and correlates with Gclc. • Reduced oxidant stress in females leads to reduced JNK activation. • JNK activation and mitochondrial translocation are critical

  2. Induction of c-myc and c-jun proto-oncogene expression in rat L6 myoblasts by cadmium is inhibited by zinc preinduction of the metallothionein gene

    Energy Technology Data Exchange (ETDEWEB)

    Abshire, M.K.; Buzard, G.S.; Shiraishi, Noriyuki; Waalkers, M.P. [National Cancer Institute, Fredrick, MD (United States)

    1996-07-01

    Certain proto-oncogenes transfer growth regulatory signals from the cell surface to the nucleus. These genes often show activation soon after cells are exposed to mitogenic stimulation but can also be activated as a nonmitogenic stress response. Cadmium (Cd) is a carcinogenic metal in humans and rodents and, though its mechanism of action is unknown, it could involve activation of such proto-oncogenes. Metallothionein (MT), a metal-inducible protein that binds Cd, can protect against many aspects of Cd toxicity, including genotoxicity and possibly carcinogenesis. Thus, the effects of Cd on expression of c-myc and c-jun in rat L6 myoblasts, and the effect of preactivation of the MT gene by Zn treatment on such oncogene expression, were studied. MT protein levels were measured using oligonucleotide hybridization and standardized to {beta}-actin levels. Cd (5 {mu}M CdCl{sub 2}, 0-30 h) stimulated both c-myc and c-jun mRNA expression. An initial peak of activation of c-myc expression occurred 2 h after initiation of Cd exposure, and levels remained elevated throughout the assessment period. Zn pretreatment markedly reduced the activation of c-myc expression by Cd compared to cells not receiving Zn pretreatment. Cd treatment increased c-jun mRNA levels by up to 3.5-fold. Again, Zn pretreatment markedly reduced. 10 refs., 8 figs.

  3. Translation of maternal histone mRNAs in sea urchin embryos: a test of control by 5' cap methylation.

    Science.gov (United States)

    Showman, R M; Leaf, D S; Anstrom, J A; Raff, R A

    1987-05-01

    Recent results have demonstrated the occurrence of mRNA cap methylation in the sea urchin embryo following fertilization. It has been suggested that this methylation event is responsible for the translational activation of maternal histone mRNAs in these embryos. We have used aphidicolin, an effective inhibitor of both DNA synthesis and cap methylation in cleavage stage sea urchin embryos, to examine the relationship between cap methylation and translation. At 5 micrograms/ml, a dose which rapidly abolishes DNA replication and blocks cleavage, we note no effect on recruitment or translation of maternal alpha-subtype histone mRNAs. This suggests that a postfertilization cap methylation event is not critical to the process of regulation of the translation of stored alpha-subtype histone mRNAs.

  4. Dual regulation by pairs of cyclin-dependent protein kinases and histone deacetylases controls G1 transcription in budding yeast.

    Directory of Open Access Journals (Sweden)

    Dongqing Huang

    2009-09-01

    Full Text Available START-dependent transcription in Saccharomyces cerevisiae is regulated by two transcription factors SBF and MBF, whose activity is controlled by the binding of the repressor Whi5. Phosphorylation and removal of Whi5 by the cyclin-dependent kinase (CDK Cln3-Cdc28 alleviates the Whi5-dependent repression on SBF and MBF, initiating entry into a new cell cycle. This Whi5-SBF/MBF transcriptional circuit is analogous to the regulatory pathway in mammalian cells that features the E2F family of G1 transcription factors and the retinoblastoma tumor suppressor protein (Rb. Here we describe genetic and biochemical evidence for the involvement of another CDK, Pcl-Pho85, in regulating G1 transcription, via phosphorylation and inhibition of Whi5. We show that a strain deleted for both PHO85 and CLN3 has a slow growth phenotype, a G1 delay, and is severely compromised for SBF-dependent reporter gene expression, yet all of these defects are alleviated by deletion of WHI5. Our biochemical and genetic tests suggest Whi5 mediates repression in part through interaction with two histone deacetylases (HDACs, Hos3 and Rpd3. In a manner analogous to cyclin D/CDK4/6, which phosphorylates Rb in mammalian cells disrupting its association with HDACs, phosphorylation by the early G1 CDKs Cln3-Cdc28 and Pcl9-Pho85 inhibits association of Whi5 with the HDACs. Contributions from multiple CDKs may provide the precision and accuracy necessary to activate G1 transcription when both internal and external cues are optimal.

  5. Control of differentiation in a self-renewing mammalian tissue by the histone demethylase JMJD3

    Science.gov (United States)

    Sen, George L.; Webster, Daniel E.; Barragan, Deborah I.; Chang, Howard Y.; Khavari, Paul A.

    2008-01-01

    The recent discovery of H3K27me3 demethylases suggests that H3K27me3 may dynamically regulate gene expression, but this potential role in mammalian tissue homeostasis remains uncharacterized. In the epidermis, a tissue that balances stem cell self-renewal with differentiation, H3K27me3, occupies the promoters of many differentiation genes. During calcium-induced differentiation, H3K27me3 was erased at these promoters in concert with loss of PcG protein occupancy and increased binding by the H3K27me3 demethylase, JMJD3. Within epidermal tissue, JMJD3 depletion blocked differentiation, while active JMJD3 dominantly induced it. These results indicate that epigenetic derepression by JMJD3 controls mammalian epidermal differentiation. PMID:18628393

  6. Interplay between viral Tat protein and c-Jun transcription factor in controlling LTR promoter activity in different human immunodeficiency virus type I subtypes

    NARCIS (Netherlands)

    van der Sluis, Renée M.; Derking, Ronald; Breidel, Seyguerney; Speijer, Dave; Berkhout, Ben; Jeeninga, Rienk E.

    2014-01-01

    HIV-1 transcription depends on cellular transcription factors that bind to sequences in the long-terminal repeat (LTR) promoter. Each HIV-1 subtype has a specific LTR promoter configuration, and minor sequence changes in transcription factor binding sites (TFBSs) or their arrangement can influence

  7. Erasing the methyl mark: histone demethylases at the center of cellular differentiation and disease

    DEFF Research Database (Denmark)

    Cloos, Paul A C; Christensen, Jesper; Agger, Karl

    2008-01-01

    The enzymes catalyzing lysine and arginine methylation of histones are essential for maintaining transcriptional programs and determining cell fate and identity. Until recently, histone methylation was regarded irreversible. However, within the last few years, several families of histone...... demethylases erasing methyl marks associated with gene repression or activation have been identified, underscoring the plasticity and dynamic nature of histone methylation. Recent discoveries have revealed that histone demethylases take part in large multiprotein complexes synergizing with histone deacetylases......, histone methyltransferases, and nuclear receptors to control developmental and transcriptional programs. Here we review the emerging biochemical and biological functions of the histone demethylases and discuss their potential involvement in human diseases, including cancer....

  8. Quinacrine induces apoptosis in human leukemia K562 cells via p38 MAPK-elicited BCL2 down-regulation and suppression of ERK/c-Jun-mediated BCL2L1 expression

    Energy Technology Data Exchange (ETDEWEB)

    Changchien, Jung-Jung; Chen, Ying-Jung; Huang, Chia-Hui [Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Cheng, Tian-Lu [Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Lin, Shinne-Ren [Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Chang, Long-Sen, E-mail: lschang@mail.nsysu.edu.tw [Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Department of Biotechnology, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China)

    2015-04-01

    Although previous studies have revealed the anti-cancer activity of quinacrine, its effect on leukemia is not clearly resolved. We sought to explore the cytotoxic effect and mechanism of quinacrine action in human leukemia K562 cells. Quinacrine induced K562 cell apoptosis accompanied with ROS generation, mitochondrial depolarization, and down-regulation of BCL2L1 and BCL2. Upon exposure to quinacrine, ROS-mediated p38 MAPK activation and ERK inactivation were observed in K562 cells. Quinacrine-induced cell death and mitochondrial depolarization were suppressed by the p38MAPK inhibitor SB202190 and constitutively active MEK1 over-expression. Activation of p38 MAPK was shown to promote BCL2 degradation. Further, ERK inactivation suppressed c-Jun-mediated transcriptional expression of BCL2L1. Over-expression of BCL2L1 and BCL2 attenuated quinacrine-evoked mitochondrial depolarization and rescued the viability of quinacrine-treated cells. Taken together, our data indicate that quinacrine-induced K562 cell apoptosis is mediated through mitochondrial alterations triggered by p38 MAPK-mediated BCL2 down-regulation and suppression of ERK/c-Jun-mediated BCL2L1 expression. - Highlights: • Quinacrine induces K562 cell apoptosis via down-regulation of BCL2 and BCL2L1. • Quinacrine induces p38 MAPK activation and ERK inactivation in K562 cells. • Quinacrine elicits p38 MAPK-mediated BCL2 down-regulation. • Quinacrine suppresses ERK/c-Jun-mediated BCL2L1 expression.

  9. AT1 receptor induced alterations in histone H2A reveal novel insights into GPCR control of chromatin remodeling.

    Directory of Open Access Journals (Sweden)

    Rajaganapathi Jagannathan

    2010-09-01

    Full Text Available Chronic activation of angiotensin II (AngII type 1 receptor (AT(1R, a prototypical G protein-coupled receptor (GPCR induces gene regulatory stress which is responsible for phenotypic modulation of target cells. The AT(1R-selective drugs reverse the gene regulatory stress in various cardiovascular diseases. However, the molecular mechanisms are not clear. We speculate that activation states of AT(1R modify the composition of histone isoforms and post-translational modifications (PTM, thereby alter the structure-function dynamics of chromatin. We combined total histone isolation, FPLC separation, and mass spectrometry techniques to analyze histone H2A in HEK293 cells with and without AT(1R activation. We have identified eight isoforms: H2AA, H2AG, H2AM, H2AO, H2AQ, Q96QV6, H2AC and H2AL. The isoforms, H2AA, H2AC and H2AQ were methylated and H2AC was phosphorylated. The relative abundance of specific H2A isoforms and PTMs were further analyzed in relationship to the activation states of AT(1R by immunochemical studies. Within 2 hr, the isoforms, H2AA/O exchanged with H2AM. The monomethylated H2AC increased rapidly and the phosphorylated H2AC decreased, thus suggesting that enhanced H2AC methylation is coupled to Ser1p dephosphorylation. We show that H2A125Kme1 promotes interaction with the heterochromatin associated protein, HP1α. These specific changes in H2A are reversed by treatment with the AT(1R specific inhibitor losartan. Our analysis provides a first step towards an awareness of histone code regulation by GPCRs.

  10. Rewiring AMPK and Mitochondrial Retrograde Signaling for Metabolic Control of Aging and Histone Acetylation in Respiratory-Defective Cells

    Directory of Open Access Journals (Sweden)

    R. Magnus N. Friis

    2014-04-01

    Full Text Available Abnormal respiratory metabolism plays a role in numerous human disorders. We find that regulation of overall histone acetylation is perturbed in respiratory-incompetent (ρ0 yeast. Because histone acetylation is highly sensitive to acetyl-coenzyme A (acetyl-CoA availability, we sought interventions that suppress this ρ0 phenotype through reprogramming metabolism. Nutritional intervention studies led to the discovery that genetic coactivation of the mitochondrion-to-nucleus retrograde (RTG response and the AMPK (Snf1 pathway prevents abnormal histone deacetylation in ρ0 cells. Metabolic profiling of signaling mutants uncovered links between chromatin-dependent phenotypes of ρ0 cells and metabolism of ATP, acetyl-CoA, glutathione, branched-chain amino acids, and the storage carbohydrate trehalose. Importantly, RTG/AMPK activation reprograms energy metabolism to increase the supply of acetyl-CoA to lysine acetyltransferases and extend the chronological lifespan of ρ0 cells. Our results strengthen the framework for rational design of nutrient supplementation schemes and drug-discovery initiatives aimed at mimicking the therapeutic benefits of dietary interventions.

  11. Histone demethylases in development and disease

    DEFF Research Database (Denmark)

    Pedersen, Marianne Terndrup; Helin, Kristian

    2010-01-01

    Histone modifications serve as regulatory marks that are instrumental for the control of transcription and chromatin architecture. Strict regulation of gene expression patterns is crucial during development and differentiation, where diverse cell types evolve from common predecessors. Since...... the first histone lysine demethylase was discovered in 2004, a number of demethylases have been identified and implicated in the control of gene expression programmes and cell fate decisions. Histone demethylases are now emerging as important players in developmental processes and have been linked to human...

  12. Polymeric Immunoglobulin Receptor-mediated Invasion of Streptococcus pneumoniae into Host Cells Requires a Coordinate Signaling of SRC Family of Protein-tyrosine Kinases, ERK, and c-Jun N-terminal Kinase*

    Science.gov (United States)

    Agarwal, Vaibhav; Asmat, Tauseef M.; Dierdorf, Nina I.; Hauck, Christof R.; Hammerschmidt, Sven

    2010-01-01

    Streptococcus pneumoniae are commensals of the human nasopharynx with the capacity to invade mucosal respiratory cells. PspC, a pneumococcal surface protein, interacts with the human polymeric immunoglobulin receptor (pIgR) to promote bacterial adherence to and invasion into epithelial cells. Internalization of pneumococci requires the coordinated action of actin cytoskeleton rearrangements and the retrograde machinery of pIgR. Here, we demonstrate the involvement of Src protein-tyrosine kinases (PTKs), focal adhesion kinase (FAK), extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) but not p38 mitogen-activated protein kinases (MAPK) in pneumococcal invasion via pIgR. Pharmacological inhibitors of PTKs and MAPKs and genetic interference with Src PTK and FAK functions caused a significant reduction of pIgR-mediated pneumococcal invasion but did not influence bacterial adhesion to host cells. Furthermore, pneumococcal ingestion by host cells induces activation of ERK1/2 and JNK. In agreement with activated JNK, its target molecule and DNA-binding protein c-Jun was phosphorylated. We also show that functionally active Src PTK is essential for activation of ERK1/2 upon pneumococcal infections. In conclusion, these data illustrate the importance of a coordinated signaling between Src PTKs, ERK1/2, and JNK during PspC-pIgR-mediated uptake of pneumococci by host epithelial cells. PMID:20829350

  13. Polymeric immunoglobulin receptor-mediated invasion of Streptococcus pneumoniae into host cells requires a coordinate signaling of SRC family of protein-tyrosine kinases, ERK, and c-Jun N-terminal kinase.

    Science.gov (United States)

    Agarwal, Vaibhav; Asmat, Tauseef M; Dierdorf, Nina I; Hauck, Christof R; Hammerschmidt, Sven

    2010-11-12

    Streptococcus pneumoniae are commensals of the human nasopharynx with the capacity to invade mucosal respiratory cells. PspC, a pneumococcal surface protein, interacts with the human polymeric immunoglobulin receptor (pIgR) to promote bacterial adherence to and invasion into epithelial cells. Internalization of pneumococci requires the coordinated action of actin cytoskeleton rearrangements and the retrograde machinery of pIgR. Here, we demonstrate the involvement of Src protein-tyrosine kinases (PTKs), focal adhesion kinase (FAK), extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) but not p38 mitogen-activated protein kinases (MAPK) in pneumococcal invasion via pIgR. Pharmacological inhibitors of PTKs and MAPKs and genetic interference with Src PTK and FAK functions caused a significant reduction of pIgR-mediated pneumococcal invasion but did not influence bacterial adhesion to host cells. Furthermore, pneumococcal ingestion by host cells induces activation of ERK1/2 and JNK. In agreement with activated JNK, its target molecule and DNA-binding protein c-Jun was phosphorylated. We also show that functionally active Src PTK is essential for activation of ERK1/2 upon pneumococcal infections. In conclusion, these data illustrate the importance of a coordinated signaling between Src PTKs, ERK1/2, and JNK during PspC-pIgR-mediated uptake of pneumococci by host epithelial cells.

  14. Histone variants and lipid metabolism

    NARCIS (Netherlands)

    Borghesan, Michela; Mazzoccoli, Gianluigi; Sheedfar, Fareeba; Oben, Jude; Pazienza, Valerio; Vinciguerra, Manlio

    2014-01-01

    Within nucleosomes, canonical histones package the genome, but they can be opportunely replaced with histone variants. The incorporation of histone variants into the nucleosome is a chief cellular strategy to regulate transcription and cellular metabolism. In pathological terms, cellular steatosis

  15. SnapShot: histone modifications

    National Research Council Canada - National Science Library

    Huang, He; Sabari, Benjamin R; Garcia, Benjamin A; Allis, C David; Zhao, Yingming

    2014-01-01

    Histone proteins are decorated by a variety of protein posttranslational modifications called histone marks that modulate chromatin structure and function, contributing to the cellular gene expression program...

  16. Histone phosphorylation: a chromatin modification involved in diverse nuclear events.

    Science.gov (United States)

    Rossetto, Dorine; Avvakumov, Nikita; Côté, Jacques

    2012-10-01

    Histone posttranslational modifications are key components of diverse processes that modulate chromatin structure. These marks function as signals during various chromatin-based events, and act as platforms for recruitment, assembly or retention of chromatin-associated factors. The best-known function of histone phosphorylation takes place during cellular response to DNA damage, when phosphorylated histone H2A(X) demarcates large chromatin domains around the site of DNA breakage. However, multiple studies have also shown that histone phosphorylation plays crucial roles in chromatin remodeling linked to other nuclear processes. In this review, we summarize the current knowledge of histone phosphorylation and describe the many kinases and phosphatases that regulate it. We discuss the key roles played by this histone mark in DNA repair, transcription and chromatin compaction during cell division and apoptosis. Additionally, we describe the intricate crosstalk that occurs between phosphorylation and other histone modifications and allows for sophisticated control over the chromatin remodeling processes.

  17. CD4+ T cell lineage integrity is controlled by the histone deacetylases HDAC1 and HDAC2

    Science.gov (United States)

    Goeschl, Lisa; Moser, Mirjam A.; Lagger, Sabine; Sakaguchi, Shinya; Winter, Mircea; Lenz, Florian; Vitko, Dijana; Breitwieser, Florian P.; Müller, Lena; Hassan, Hammad; Bennett, Keiryn L.; Colinge, Jacques; Schreiner, Wolfgang; Egawa, Takeshi; Taniuchi, Ichiro; Matthias, Patrick; Seiser, Christian; Ellmeier, Wilfried

    2015-01-01

    Molecular mechanisms that maintain lineage integrity of helper T cells are largely unknown. Here we show histone deacetylases (HDAC) 1 and 2 as crucial regulators of this process. Loss of HDAC1 and HDAC2 during late T cell development led to the appearance of MHC class II-selected CD4+ helper T cells (TH) that expressed CD8 lineage genes such as Cd8a and Cd8b1. HDAC1-HDAC2-deficient TH0 and TH1 cells further up-regulated Cd8 lineage genes and acquired a CD8 effector program in a manner dependent on Runx-CBFβ complexes, while TH2 cells repressed CD8 lineage features independently of HDAC1 and HDAC2. These results demonstrate that HDAC1-HDAC2 maintain CD4 lineage integrity by repressing Runx-CBFβ complexes that otherwise induce a CD8-like effector program in CD4+ T cells. PMID:24681565

  18. Equine herpesvirus type 1 replication is delayed in CD172a+ monocytic cells and controlled by histone deacetylases.

    Science.gov (United States)

    Laval, Kathlyn; Favoreel, Herman W; Nauwynck, Hans J

    2015-01-01

    Equine herpesvirus type 1 (EHV-1) replicates in the epithelial cells of the upper respiratory tract and disseminates through the body via a cell-associated viraemia in monocytic cells, despite the presence of neutralizing antibodies. However, the mechanism by which EHV-1 hijacks immune cells and uses them as 'Trojan horses' in order to disseminate inside its host is still unclear. Here, we hypothesize that EHV-1 delays its replication in monocytic cells in order to avoid recognition by the immune system. We compared replication kinetics in vitro of EHV-1 in RK-13, a cell line fully susceptible to EHV-1 infection, and primary horse cells from the myeloid lineage (CD172a(+)). We found that EHV-1 replication was restricted to 4 % of CD172a(+) cells compared with 100 % in RK-13 cells. In susceptible CD172a(+) cells, the expression of immediate-early (IEP) and early (EICP22) proteins was delayed in the cell nuclei by 2-3 h post-infection (p.i.) compared with RK-13, and the formation of replicative compartments by 15 h p.i. Virus production in CD172a(+) cells was significantly lower (from 10(1.7) to 10(3.1) TCID50 per 10(5) inoculated cells) than in RK-13 (from 10(5) to 10(5.7) TCID50 per 10(5) inoculated cells). Less than 0.02 % of inoculated CD172a(+) cells produced and transmitted infectious virus to neighbouring cells. Pre-treatment of CD172a(+) cells with inhibitors of histone deacetylase activity increased and accelerated viral protein expression at very early times of infection and induced productive infection in CD172a(+) cells. Our results demonstrated that the restriction and delay of EHV-1 replication in CD172a(+) cells are part of an immune evasive strategy and involve silencing of EHV-1 gene expression associated with histone deacetylases. © 2015 The Authors.

  19. SET DOMAIN GROUP 708, a histone H3 lysine 36-specific methyltransferase, controls flowering time in rice (Oryza sativa).

    Science.gov (United States)

    Liu, Bing; Wei, Gang; Shi, Jinlei; Jin, Jing; Shen, Ting; Ni, Ting; Shen, Wen-Hui; Yu, Yu; Dong, Aiwu

    2016-04-01

    As a key epigenetic modification, the methylation of histone H3 lysine 36 (H3K36) modulates chromatin structure and is involved in diverse biological processes. To better understand the language of H3K36 methylation in rice (Oryza sativa), we chose potential histone methylation enzymes for functional exploration. In particular, we characterized rice SET DOMAIN GROUP 708 (SDG708) as an H3K36-specific methyltransferase possessing the ability to deposit up to three methyl groups on H3K36. Compared with the wild-type, SDG708-knockdown rice mutants displayed a late-flowering phenotype under both long-day and short-day conditions because of the down-regulation of the key flowering regulatory genes Heading date 3a (Hd3a), RICE FLOWERING LOCUS T1 (RFT1), and Early heading date 1 (Ehd1). Chromatin immunoprecipitation experiments indicated that H3K36me1, H3K36me2, and H3K36me3 levels were reduced at these loci in SDG708-deficient plants. More importantly, SDG708 was able to directly target and effect H3K36 methylation on specific flowering genes. In fact, knockdown of SDG708 led to misexpression of a set of functional genes and a genome-wide decrease in H3K36me1/2/3 levels during the early growth stages of rice. SDG708 is a methyltransferase that catalyses genome-wide deposition of all three methyl groups on H3K36 and is involved in many biological processes in addition to flowering promotion. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  20. Roles of PI3K/Akt and c-Jun signaling pathways in human papillomavirus type 16 oncoprotein-induced HIF-1α, VEGF, and IL-8 expression and in vitro angiogenesis in non-small cell lung cancer cells.

    Directory of Open Access Journals (Sweden)

    Erying Zhang

    Full Text Available Human papillomavirus (HPV-16 infection may be related to non-smoking associated lung cancer. Our previous studies have found that HPV-16 oncoproteins promoted angiogenesis via enhancing hypoxia-inducible factor-1α (HIF-1α, vascular endothelial growth factor (VEGF, and interleukin-8 (IL-8 expression in non-small cell lung cancer (NSCLC cells. In this study, we further investigated the roles of PI3K/Akt and c-Jun signaling pathways in it.Human NSCLC cell lines, A549 and NCI-H460, were stably transfected with pEGFP-16 E6 or E7 plasmids. Western blotting was performed to analyze the expression of HIF-1α, p-Akt, p-P70S6K, p-P85S6K, p-mTOR, p-JNK, and p-c-Jun proteins. VEGF and IL-8 protein secretion and mRNA levels were determined by ELISA and Real-time PCR, respectively. The in vitro angiogenesis was observed by human umbilical vein endothelial cells (HUVECs tube formation assay. Co-immunoprecipitation was performed to analyze the interaction between c-Jun and HIF-1α.HPV-16 E6 and E7 oncoproteins promoted the activation of Akt, P70S6K, P85S6K, mTOR, JNK, and c-Jun. LY294002, a PI3K inhibitor, inhibited HPV-16 oncoprotein-induced activation of Akt, P70S6K, and P85S6K, expression of HIF-1α, VEGF, and IL-8, and in vitro angiogenesis. c-Jun knockdown by specific siRNA abolished HPV-16 oncoprotein-induced HIF-1α, VEGF, and IL-8 expression and in vitro angiogenesis. Additionally, HPV-16 oncoproteins promoted HIF-1α protein stability via blocking proteasome degradation pathway, but c-Jun knockdown abrogated this effect. Furthermore, HPV-16 oncoproteins increased the quantity of c-Jun binding to HIF-1α.PI3K/Akt signaling pathway and c-Jun are involved in HPV-16 oncoprotein-induced HIF-1α, VEGF, and IL-8 expression and in vitro angiogenesis. Moreover, HPV-16 oncoproteins promoted HIF-1α protein stability possibly through enhancing the interaction between c-Jun and HIF-1α, thus making a contribution to angiogenesis in NSCLC cells.

  1. Hyperoside Downregulates the Receptor for Advanced Glycation End Products (RAGE and Promotes Proliferation in ECV304 Cells via the c-Jun N-Terminal Kinases (JNK Pathway Following Stimulation by Advanced Glycation End-Products In Vitro

    Directory of Open Access Journals (Sweden)

    Zhengyu Zhang

    2013-11-01

    Full Text Available Hyperoside is a major active constituent in many medicinal plants which are traditionally used in Chinese medicines for their neuroprotective, anti-inflammatory and antioxidative effects. The molecular mechanisms underlying these effects are unknown. In this study, quiescent ECV304 cells were treated in vitro with advanced glycation end products (AGEs in the presence or absence of hyperoside. The results demonstrated that AGEs induced c-Jun N-terminal kinases (JNK activation and apoptosis in ECV304 cells. Hyperoside inhibited these effects and promoted ECV304 cell proliferation. Furthermore, hyperoside significantly inhibited RAGE expression in AGE-stimulated ECV304 cells, whereas knockdown of RAGE inhibited AGE-induced JNK activation. These results suggested that AGEs may promote JNK activation, leading to viability inhibition of ECV304 cells via the RAGE signaling pathway. These effects could be inhibited by hyperoside. Our findings suggest a novel role for hyperoside in the treatment and prevention of diabetes.

  2. Highly Oxygenated Sesquiterpene Lactones from Cousinia aitchisonii and their Cytotoxic Properties: Rhaserolide Induces Apoptosis in Human T Lymphocyte (Jurkat) Cells via the Activation of c-Jun n-terminal Kinase Phosphorylation.

    Science.gov (United States)

    Iranshahy, Milad; Tayarani-Najaran, Zahra; Kasaian, Jamal; Ghandadi, Morteza; Emami, Seyed Ahmad; Asili, Javad; Chandran, Jima N; Schneider, Bernd; Iranshahi, Mehrdad

    2016-02-01

    Infrared-guided chromatographic fractionation of sesquiterpene lactones from the extracts of Cousinia aitchisonii and Cousinia concolor led to the isolation of five pure compounds. A new sesquiterpene lactone, namely, aitchisonolide, and two known sesquiterpene lactones (desoxyjanerin and rhaserolide) were isolated from C. aitchisonii and two known lignans (arctiin and arctigenin) from C. concolor. The structures of these compounds were elucidated by one-dimensional and two-dimensional nuclear magnetic resonance techniques, as well as high-resolution mass spectrometry. The purified and characterized compounds were subjected to cytotoxicity assay. The sesquiterpene lactones desoxyjanerin and rhaserolide showed significant cytotoxic activities against five different cancer cell lines and the normal human embryonic kidney cell line. Rhaserolide was chosen to evaluate the possible mechanism of action. Western blot analysis revealed that rhaserolide could induce apoptosis in Jurkat cells via the activation of c-Jun n-terminal kinase phosphorylation. Copyright © 2015 John Wiley & Sons, Ltd.

  3. Mesenchymal stem cells promote liver regeneration and prolong survival in small-for-size liver grafts: involvement of C-Jun N-terminal kinase, cyclin D1, and NF-κB.

    Directory of Open Access Journals (Sweden)

    Weijie Wang

    Full Text Available BACKGROUND: The therapeutic potential of mesenchymal stem cells (MSCs has been highlighted recently for treatment of acute or chronic liver injury, by possibly differentiating into hepatocyte-like cells, reducing inflammation, and enhancing tissue repair. Despite recent progress, exact mechanisms of action are not clearly elucidated. In this study, we attempted to explore whether and how MSCs protected hepatocytes and stimulated allograft regeneration in small-for-size liver transplantation (SFSLT. METHODS: SFSLT model was established with a 30% partial liver transplantation (30PLT in rats. The differentiation potential and characteristics of bone marrow derived MSCs were explored in vitro. MSCs were infused transvenously immediately after graft implantation in therapy group. Expressions of apoptosis-, inflammatory-, anti-inflammatory-, and growth factor-related genes were measured by RT-PCR, activities of transcription factors AP-1 and NF-κB were analyzed by EMSA, and proliferative responses of the hepatic graft were evaluated by immunohistochemistry and western blot. RESULTS: MSCs were successfully induced into hepatocyte-like cells, osteoblasts and adipocytes in vitro. MSCs therapy could not only alleviate ischemia reperfusion injury and acute inflammation to promote liver regeneration, but also profoundly improve one week survival rate. It markedly up-regulated the mRNA expressions of HGF, Bcl-2, Bcl-XL, IL-6, IL-10, IP-10, and CXCR2, however, down-regulated TNF-α. Increased activities of AP-1 and NF-κB, as well as elevated expressions of p-c-Jun, cyclin D1, and proliferating cell nuclear antigen (PCNA, were also found in MSCs therapy group. CONCLUSION: These data suggest that MSCs therapy promotes hepatocyte proliferation and prolongs survival in SFSLT by reducing ischemia reperfusion injury and acute inflammation, and sustaining early increased expressions of c-Jun N-terminal Kinase, Cyclin D1, and NF-κB.

  4. Formaldehyde-induced histone H3 phosphorylation via JNK and the expression of proto-oncogenes

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Ikuma; Ibuki, Yuko, E-mail: ibuki@u-shizuoka-ken.ac.jp

    2014-12-15

    Graphical abstract: - Highlights: • Formaldehyde modified histones. • The phosphorylation of H3S10 was increased at the promoter regions of proto-oncogenes. • The phosphorylation of H2AXS139 was attributed to FA-induced DNA damage. • The FA-induced initiation and promotion of cancer could be judged by these modifications. - Abstract: Formaldehyde (FA) is a very reactive compound that forms DNA adducts and DNA-protein crosslinks, which are known to contribute to FA-induced mutations and carcinogenesis. Post-translational modifications to histones have recently attracted attention due to their link with cancer. In the present study, we examined histone modifications following a treatment with FA. FA significantly phosphorylated histone H3 at serine 10 (H3S10), and at serine 28 (H3S28), the time-course of which was similar to the phosphorylation of H2AX at serine 139 (γ-H2AX), a marker of DNA double strand breaks. The temporal deacetylation of H3 was observed due to the reaction of FA with the lysine residues of histones. The phosphorylation mechanism was then analyzed by focusing on H3S10. The nuclear distribution of the phosphorylation of H3S10 and γ-H2AX did not overlap, and the phosphorylation of H3S10 could not be suppressed with an inhibitor of ATM/ATR, suggesting that the phosphorylation of H3S10 was independent of the DNA damage response. ERK and JNK in the MAPK pathways were phosphorylated by the treatment with FA, in which the JNK pathway was the main target for phosphorylation. The phosphorylation of H3S10 increased at the promoter regions of c-fos and c-jun, indicating a relationship between FA-induced tumor promotion activity and phosphorylation of H3S10. These results suggested that FA both initiates and promotes cancer, as judged by an analysis of histone modifications.

  5. Synthetic histone code.

    Science.gov (United States)

    Fischle, Wolfgang; Mootz, Henning D; Schwarzer, Dirk

    2015-10-01

    Chromatin is the universal template of genetic information in all eukaryotic cells. This complex of DNA and histone proteins not only packages and organizes genomes but also regulates gene expression. A multitude of posttranslational histone modifications and their combinations are thought to constitute a code for directing distinct structural and functional states of chromatin. Methods of protein chemistry, including protein semisynthesis, amber suppression technology, and cysteine bioconjugation, have enabled the generation of so-called designer chromatin containing histones in defined and homogeneous modification states. Several of these approaches have matured from proof-of-concept studies into efficient tools and technologies for studying the biochemistry of chromatin regulation and for interrogating the histone code. We summarize pioneering experiments and recent developments in this exciting field of chemical biology. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Transcription factor 19 interacts with histone 3 lysine 4 trimethylation and controls gluconeogenesis via the nucleosome-remodeling-deacetylase complex.

    Science.gov (United States)

    Sen, Sabyasachi; Sanyal, Sulagna; Srivastava, Dushyant Kumar; Dasgupta, Dipak; Roy, Siddhartha; Das, Chandrima

    2017-12-15

    Transcription factor 19 (TCF19) has been reported as a type 1 diabetes-associated locus involved in maintenance of pancreatic β cells through a fine-tuned regulation of cell proliferation and apoptosis. TCF19 also exhibits genomic association with type 2 diabetes, although the precise molecular mechanism remains unknown. It harbors both a plant homeodomain and a forkhead-associated domain implicated in epigenetic recognition and gene regulation, a phenomenon that has remained unexplored. Here, we show that TCF19 selectively interacts with histone 3 lysine 4 trimethylation through its plant homeodomain finger. Knocking down TCF19 under high-glucose conditions affected many metabolic processes, including gluconeogenesis. We found that TCF19 overexpression represses de novo glucose production in HepG2 cells. The transcriptional repression of key genes, induced by TCF19, coincided with NuRD (nucleosome-remodeling-deacetylase) complex recruitment to the promoters of these genes. TCF19 interacted with CHD4 (chromodomain helicase DNA-binding protein 4), which is a part of the NuRD complex, in a glucose concentration-independent manner. In summary, our results show that TCF19 interacts with an active transcription mark and recruits a co-repressor complex to regulate gluconeogenic gene expression in HepG2 cells. Our study offers critical insights into the molecular mechanisms of transcriptional regulation of gluconeogenesis and into the roles of chromatin readers in metabolic homeostasis. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. Plant-specific Histone Deacetylases HDT½ Regulate GIBBERELLIN 2-OXIDASE 2 Expression to Control Arabidopsis Root Meristem Cell Number

    KAUST Repository

    Li, Huchen

    2017-08-31

    Root growth is modulated by environmental factors and depends on cell production in the root meristem (RM). New cells in the meristem are generated by stem cells and transit-amplifying cells, which together determine RM cell number. Transcription factors and chromatin-remodelling factors have been implicated in regulating the switch from stem cells to transit-amplifying cells. Here we show that two Arabidopsis thaliana paralogs encoding plant-specific histone deacetylases, HDT1 and HDT2, regulate a second switch from transit-amplifying cells to expanding cells. Knockdown of HDT½ (hdt1,2i) results in an earlier switch and causes a reduced RM cell number. Our data show that HDT½ negatively regulate the acetylation level of the C19-GIBBERELLIN 2-OXIDASE 2 (GA2ox2) locus and repress the expression of GA2ox2 in the RM and elongation zone. Overexpression of GA2ox2 in the RM phenocopies the hdt1,2i phenotype. Conversely, knockout of GA2ox2 partially rescues the root growth defect of hdt1,2i. These results suggest that by repressing the expression of GA2ox2, HDT½ likely fine-tune gibberellin metabolism and they are crucial for regulating the switch from cell division to expansion to determine RM cell number. We propose that HDT½ function as part of a mechanism that modulates root growth in response to environmental factors.

  8. Structural and Functional Coordination of DNA and Histone Methylation

    Science.gov (United States)

    Cheng, Xiaodong

    2014-01-01

    One of the most fundamental questions in the control of gene expression in mammals is how epigenetic methylation patterns of DNA and histones are established, erased, and recognized. This central process in controlling gene expression includes coordinated covalent modifications of DNA and its associated histones. This article focuses on structural aspects of enzymatic activities of histone (arginine and lysine) methylation and demethylation and functional links between the methylation status of the DNA and histones. An interconnected network of methyltransferases, demethylases, and accessory proteins is responsible for changing or maintaining the modification status of specific regions of chromatin. PMID:25085914

  9. Endometriosis is characterized by a distinct pattern of histone 3 and histone 4 lysine modifications.

    Science.gov (United States)

    Monteiro, Janice B; Colón-Díaz, Maricarmen; García, Miosotis; Gutierrez, Sylvia; Colón, Mariano; Seto, Edward; Laboy, Joaquín; Flores, Idhaliz

    2014-03-01

    The histone modification patterns in endometriosis have not been fully characterized. This gap in knowledge results in a poor understanding of the epigenetic mechanisms (and potential therapeutic targets) at play. We aimed to (1) assess global acetylation status of histone 3 (H3) and histone 4 (H4), (2) measure levels of H3 and H4 lysine (K) acetylation and methylation, and (3) to identify histone acetylation patterns in promoter regions of candidate genes in tissues from patients and controls. Global and K-specific acetylation/methylation levels of histones were measured in 24 lesions, 15 endometrium from patients, and 26 endometrium from controls. Chromatin immunoprecipitation (ChIP)-polymerase chain reaction was used to determine the histone acetylation status of the promoter regions of candidate genes in tissues. The lesions were globally hypoacetylated at H3 (but not H4) compared to eutopic endometrium from controls. Lesions had significantly lower levels of H3K9ac and H4K16ac compared to eutopic endometrium from patients and controls. Tissues from patients were hypermethylated at H3K4, H3K9, and H3K27 compared to endometrium from controls. The ChIP analysis showed hypoacetylation of H3/H4 within promoter regions of candidate genes known to be downregulated in endometriosis (e.g., HOXA10, ESR1, CDH1, and p21 (WAF1/Cip1) ) in lesions versus control endometrium. The stereoidogenic factor 1 (SF1) promoter region was enriched for acetylated H3 and H4 in lesions versus control tissues, correlating with its reported high expression in lesions. This study describes the histone code of lesions and endometrium from patients with endometriosis and provides support for a possible role of histone modification in modulation of gene expression in endometriosis.

  10. Histone Lysine Methylation in Diabetic Nephropathy

    Directory of Open Access Journals (Sweden)

    Guang-dong Sun

    2014-01-01

    Full Text Available Diabetic nephropathy (DN belongs to debilitating microvascular complications of diabetes and is the leading cause of end-stage renal diseases worldwide. Furthermore, outcomes from the DCCT/EDIC study showed that DN often persists and progresses despite intensive glucose control in many diabetes patients, possibly as a result of prior episode of hyperglycemia, which is called “metabolic memory.” The underlying mechanisms responsible for the development and progression of DN remain poorly understood. Activation of multiple signaling pathways and key transcription factors can lead to aberrant expression of DN-related pathologic genes in target renal cells. Increasing evidence suggests that epigenetic mechanisms in chromatin such as DNA methylation, histone acetylation, and methylation can influence the pathophysiology of DN and metabolic memory. Exciting researches from cell culture and experimental animals have shown that key histone methylation patterns and the related histone methyltransferases and histone demethylases can play important roles in the regulation of inflammatory and profibrotic genes in renal cells under diabetic conditions. Because histone methylation is dynamic and potentially reversible, it can provide a window of opportunity for the development of much-needed novel therapeutic potential for DN in the future. In this minireview, we discuss recent advances in the field of histone methylation and its roles in the pathogenesis and progression of DN.

  11. Investigating the role of c-Jun N-terminal kinases in the proliferation of Werner syndrome fibroblasts using diaminopyridine inhibitors

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    Davis Terence

    2011-12-01

    Full Text Available Abstract Fibroblasts derived from the progeroid Werner syndrome show reduced replicative lifespan and a "stressed" morphology, both alleviated using the MAP kinase inhibitor SB203580. However, interpretation of these data is problematical because although SB203580 has the stress-activated kinases p38 and JNK1/2 as its preferred targets, it does show relatively low overall kinase selectivity. Several lines of data support a role for both p38 and JNK1/2 activation in the control of cellular proliferation and also the pathology of diseases of ageing, including type II diabetes, diseases to which Werner Syndrome individuals are prone, thus making the use of JNK inhibitors attractive as possible therapeutics. We have thus tested the effects of the widely used JNK inhibitor SP600125 on the proliferation and morphology of WS cells. In addition we synthesised and tested two recently described aminopyridine based inhibitors. SP600125 treatment resulted in the cessation of proliferation of WS cells and resulted in a senescent-like cellular phenotype that does not appear to be related to the inhibition of JNK1/2. In contrast, use of the more selective aminopyridine CMPD 6o at concentrations that fully inhibit JNK1/2 had a positive effect on cellular proliferation of immortalised WS cells, but no effect on the replicative lifespan of primary WS fibroblasts. In addition, CMPD 6o corrected the stressed WS cellular morphology. The aminopyridine CMPD 6r, however, had little effect on WS cells. CMDP 6o was also found to be a weak inhibitor of MK2, which may partially explain its effects on WS cells, since MK2 is known to be involved in regulating cellular morphology via HSP27 phosphorylation, and is thought to play a role in cell cycle arrest. These data suggest that total JNK1/2 activity does not play a substantial role in the proliferation control in WS cells.

  12. Determination of histone acetylation status by chromatin immunoprecipitation.

    Science.gov (United States)

    Galdieri, Luciano; Moon, John; Vancura, Ales

    2012-01-01

    Histone acetylation is the most studied posttranslation modification of nucleosomes. Understanding the mechanisms involved in global and promoter-specific histone acetylation will shed light on the control of transcriptional regulation. Chromatin immunoprecipitation is a powerful technique to study protein-DNA interactions in vivo. Proteins and DNA are cross-linked with formaldehyde, cells are lysed, and DNA is sheared by sonication. Protein-DNA complexes are immunoprecipitated with antibodies specific for total and acetylated histones and the relative occupancy of acetylated and total histones at selected loci is assessed by real-time PCR of the purified DNA.

  13. Histone acetylation in astrocytes suppresses GFAP and stimulates a reorganization of the intermediate filament network

    NARCIS (Netherlands)

    Kanski, Regina; Sneeboer, Marjolein A M; van Bodegraven, Emma J; Sluijs, Jacqueline A; Kropff, Wietske; Vermunt, Marit W.; Creyghton, Menno P; De Filippis, Lidia; Vescovi, Angelo; Aronica, Eleonora; van Tijn, P.; van Strien, Miriam E; Hol, Elly M

    2014-01-01

    Glial fibrillary acidic protein (GFAP) is the main intermediate filament in astrocytes and is regulated by epigenetic mechanisms during development. We demonstrate that histone acetylation also controls GFAP expression in mature astrocytes. Inhibition of histone deacetylases (HDACs) with

  14. Arabidopsis COMPASS-like complexes mediate histone H3 lysine-4 trimethylation to control floral transition and plant development.

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    Danhua Jiang

    2011-03-01

    Full Text Available Histone H3 lysine-4 (H3K4 methylation is associated with transcribed genes in eukaryotes. In Drosophila and mammals, both di- and tri-methylation of H3K4 are associated with gene activation. In contrast to animals, in Arabidopsis H3K4 trimethylation, but not mono- or di-methylation of H3K4, has been implicated in transcriptional activation. H3K4 methylation is catalyzed by the H3K4 methyltransferase complexes known as COMPASS or COMPASS-like in yeast and mammals. Here, we report that Arabidopsis homologs of the COMPASS and COMPASS-like complex core components known as Ash2, RbBP5, and WDR5 in humans form a nuclear subcomplex during vegetative and reproductive development, which can associate with multiple putative H3K4 methyltransferases. Loss of function of ARABIDOPSIS Ash2 RELATIVE (ASH2R causes a great decrease in genome-wide H3K4 trimethylation, but not in di- or mono-methylation. Knockdown of ASH2R or the RbBP5 homolog suppresses the expression of a crucial Arabidopsis floral repressor, FLOWERING LOCUS C (FLC, and FLC homologs resulting in accelerated floral transition. ASH2R binds to the chromatin of FLC and FLC homologs in vivo and is required for H3K4 trimethylation, but not for H3K4 dimethylation in these loci; overexpression of ASH2R causes elevated H3K4 trimethylation, but not H3K4 dimethylation, in its target genes FLC and FLC homologs, resulting in activation of these gene expression and consequent late flowering. These results strongly suggest that H3K4 trimethylation in FLC and its homologs can activate their expression, providing concrete evidence that H3K4 trimethylation accumulation can activate eukaryotic gene expression. Furthermore, our findings suggest that there are multiple COMPASS-like complexes in Arabidopsis and that these complexes deposit trimethyl but not di- or mono-methyl H3K4 in target genes to promote their expression, providing a molecular explanation for the observed coupling of H3K4 trimethylation (but not H3

  15. Protective effect of DA-9401 in finasteride-induced apoptosis in rat testis: inositol requiring kinase 1 and c-Jun N-terminal kinase pathway

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    Soni KK

    2017-10-01

    Full Text Available Kiran Kumar Soni,1,* Yu Seob Shin,1,* Bo Ram Choi,1 Keshab Kumar Karna,1 Hye Kyung Kim,2 Sung Won Lee,3 Chul Young Kim,4 Jong Kwan Park1 1Department of Urology, Chonbuk National University and Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute and Clinical Trial Center of Medical Device of Chonbuk National University, Jeonju, 2College of Pharmacy, Kyungsung University, Busan, 3Department of Urology, Samsung Medical Center, Samsung Biomedical Research Institute, Sungkyunkwan University Medical School, Seoul, 4College of Pharmacy, Hangyang University, Ansan, Republic of Korea *These authors contributed equally to this work Abstract: Finasteride is used to treat male pattern baldness and benign prostatic hyperplasia. This study investigated the toxicity of finasteride and recovery by DA-9401 using Sprague Dawley (SD rats. Forty adult male SD rats were assigned to four groups: control (CTR, finasteride 1 mg/kg/day (F, finasteride 1 mg/kg + DA-9401 100 mg/kg/day (F + DA 100 and finasteride 1 mg/kg + DA-9401 200 mg/kg/day (F + DA 200. Treatments were by oral delivery once daily for 90 consecutive days. The gross anatomical parameters assessed included: genital organ weight; vas deferens sperm count and sperm motility; testosterone, dihydrotestosterone (DHT and malondialdehyde levels; and histological and terminal deoxynucleotidyl transferase enzyme mediated dUTP nick-end labeling (TUNEL staining of testis for spermatogenic cell density, Johnsen’s score and apoptosis. Testicular tissue was also used for evaluating endoplasmic reticulum (ER stress and apoptotic proteins. Epididymis weight, seminal vesicle weight, prostate weight, penile weight and vas deferens sperm motility showed significant differences between the F group and the CTR, F + DA 100 and F + DA 200 groups. There was no significant change in the testosterone level. DHT level decreased significantly in the F group compared with the CTR

  16. Formaldehyde-induced histone H3 phosphorylation via JNK and the expression of proto-oncogenes.

    Science.gov (United States)

    Yoshida, Ikuma; Ibuki, Yuko

    2014-12-01

    Formaldehyde (FA) is a very reactive compound that forms DNA adducts and DNA-protein crosslinks, which are known to contribute to FA-induced mutations and carcinogenesis. Post-translational modifications to histones have recently attracted attention due to their link with cancer. In the present study, we examined histone modifications following a treatment with FA. FA significantly phosphorylated histone H3 at serine 10 (H3S10), and at serine 28 (H3S28), the time-course of which was similar to the phosphorylation of H2AX at serine 139 (γ-H2AX), a marker of DNA double strand breaks. The temporal deacetylation of H3 was observed due to the reaction of FA with the lysine residues of histones. The phosphorylation mechanism was then analyzed by focusing on H3S10. The nuclear distribution of the phosphorylation of H3S10 and γ-H2AX did not overlap, and the phosphorylation of H3S10 could not be suppressed with an inhibitor of ATM/ATR, suggesting that the phosphorylation of H3S10 was independent of the DNA damage response. ERK and JNK in the MAPK pathways were phosphorylated by the treatment with FA, in which the JNK pathway was the main target for phosphorylation. The phosphorylation of H3S10 increased at the promoter regions of c-fos and c-jun, indicating a relationship between FA-induced tumor promotion activity and phosphorylation of H3S10. These results suggested that FA both initiates and promotes cancer, as judged by an analysis of histone modifications. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Valproic Acid, a Histone Deacetylase Inhibitor, in Combination with Paclitaxel for Anaplastic Thyroid Cancer: Results of a Multicenter Randomized Controlled Phase II/III Trial

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    Maria Graziella Catalano

    2016-01-01

    Full Text Available Anaplastic thyroid cancer (ATC has a median survival less than 5 months and, to date, no effective therapy exists. Taxanes have recently been stated as the main drug treatment for ATC, and the histone deacetylase inhibitor valproic acid efficiently potentiates the effects of paclitaxel in vitro. Based on these data, this trial assessed the efficacy and safety of the combination of paclitaxel and valproic acid for the treatment of ATC. This was a randomized, controlled phase II/III trial, performed on 25 ATC patients across 5 centers in northwest Italy. The experimental arm received the combination of paclitaxel (80 mg/m2/weekly and valproic acid (1,000 mg/day; the control arm received paclitaxel alone. Overall survival and disease progression, evaluated in terms of progression-free survival, were the primary outcomes. The secondary outcome was the pharmacokinetics of paclitaxel. The coadministration of valproic acid did not influence the pharmacokinetics of paclitaxel. Neither median survival nor median time to progression was statistically different in the two arms. Median survival of operated-on patients was significantly better than that of patients who were not operated on. The present trial demonstrates that the addition of valproic acid to paclitaxel has no effect on overall survival and disease progression of ATC patients. This trial is registered with EudraCT 2008-005221-11.

  18. The c-Jun N-terminal kinase (JNK)-binding protein (JNKBP1) acts as a negative regulator of NOD2 protein signaling by inhibiting its oligomerization process.

    Science.gov (United States)

    Lecat, Aurore; Di Valentin, Emmanuel; Somja, Joan; Jourdan, Samuel; Fillet, Marianne; Kufer, Thomas A; Habraken, Yvette; Sadzot, Catherine; Louis, Edouard; Delvenne, Philippe; Piette, Jacques; Legrand-Poels, Sylvie

    2012-08-24

    NOD2 is one of the best characterized members of the cytosolic NOD-like receptor family. NOD2 is able to sense muramyl dipeptide, a specific bacterial cell wall component, and to subsequently induce various signaling pathways leading to NF-κB activation and autophagy, both events contributing to an efficient innate and adaptive immune response. Interestingly, loss-of-function NOD2 variants were associated with a higher susceptibility for Crohn disease, which highlights the physiological importance of proper regulation of NOD2 activity. We performed a biochemical screen to search for new NOD2 regulators. We identified a new NOD2 partner, c-Jun N-terminal kinase-binding protein 1 (JNKBP1), a scaffold protein characterized by an N-terminal WD-40 domain. JNKBP1, through its WD-40 domain, binds to NOD2 following muramyl dipeptide activation. This interaction attenuates NOD2-mediated NF-κB activation and IL-8 secretion as well as NOD2 antibacterial activity. JNKBP1 exerts its repressor effect by disturbing NOD2 oligomerization and RIP2 tyrosine phosphorylation, both steps required for downstream NOD2 signaling. We furthermore showed that JNKBP1 and NOD2 are co-expressed in the human intestinal epithelium and in immune cells recruited in the lamina propria, which suggests that JNKBP1 contributes to maintain NOD2-mediated intestinal immune homeostasis.

  19. Caruifolin D from artemisia absinthium L. inhibits neuroinflammation via reactive oxygen species-dependent c-jun N-terminal kinase and protein kinase c/NF-κB signaling pathways.

    Science.gov (United States)

    Zeng, Ke-Wu; Liao, Li-Xi; Song, Xiao-Min; Lv, Hai-Ning; Song, Fang-Jiao; Yu, Qian; Dong, Xin; Jiang, Yong; Tu, Peng-Fei

    2015-11-15

    This work aims to evaluate the anti-neuroinflammatory effects of natural sesquiterpene dimer caruifolin D from Artemisia absinthium L., which is an edible vegetable or traditional medicinal food in East Asia due to its sedation, anti-asthma and antipruritic effects. In this study, we reported that caruifolin D significantly inhibited the productions of various neuroinflammatory mediators from microglia in response to bacterial lipopolysaccharide stimulation. Moreover, anti-inflammatory mechanism study showed that caruifolin D markedly suppressed the production of intracellular reactive oxygen species, which was an important player involved in neuroinflammation, leading to inhibitory effects on the activations of protein kinase C (PKC) and c-Jun N-terminal kinase (JNK), which were two major neuroinflammatory signaling pathways in the brains. Furthermore, caruifolin D protected neurons against microglia-mediated neuronal inflammatory damages by up-regulating neuronal viability and maintaining healthy neuronal morphology. Taken together, these results expanded our knowledge about the anti-neuroinflammatory and neuroprotective mechanism of Artemisia absinthium L., and also suggested that caruifolin D was a major anti-inflammatory component from Artemisia absinthium L., which might be developed as a drug candidate for neuroinflammation-related diseases. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Antiepileptic Effect of Uncaria rhynchophylla and Rhynchophylline Involved in the Initiation of c-Jun N-Terminal Kinase Phosphorylation of MAPK Signal Pathways in Acute Seizures of Kainic Acid-Treated Rats

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    Hsin-Cheng Hsu

    2013-01-01

    Full Text Available Seizures cause inflammation of the central nervous system. The extent of the inflammation is related to the severity and recurrence of the seizures. Cell surface receptors are stimulated by stimulators such as kainic acid (KA, which causes intracellular mitogen-activated protein kinase (MAPK signal pathway transmission to coordinate a response. It is known that Uncaria rhynchophylla (UR and rhynchophylline (RP have anticonvulsive effects, although the mechanisms remain unclear. Therefore, the purpose of this study is to develop a novel strategy for treating epilepsy by investigating how UR and RP initiate their anticonvulsive mechanisms. Sprague-Dawley rats were administered KA (12 mg/kg, i.p. to induce seizure before being sacrificed. The brain was removed 3 h after KA administration. The results indicate that pretreatment with UR (1.0 g/kg, RP (0.25 mg/kg, and valproic acid (VA, 250 mg/kg for 3 d could reduce epileptic seizures and could also reduce the expression of c-Jun aminoterminal kinase phosphorylation (JNKp of MAPK signal pathways in the cerebral cortex and hippocampus brain tissues. Proinflammatory cytokines interleukin (IL-1β, IL-6, and tumor necrosis factor-α remain unchanged, indicating that the anticonvulsive effect of UR and RP is initially involved in the JNKp MAPK signal pathway during the KA-induced acute seizure period.

  1. c-Jun N-terminal kinase 2 prevents luminal cell commitment in normal mammary glands and tumors by inhibiting p53/Notch1 and breast cancer gene 1 expression

    Science.gov (United States)

    Pfefferle, Adam D.; Perou, Charles M.; Van Den Berg, Carla Lynn

    2015-01-01

    Breast cancer is a heterogeneous disease with several subtypes carrying unique prognoses. Patients with differentiated luminal tumors experience better outcomes, while effective treatments are unavailable for poorly differentiated tumors, including the basal-like subtype. Mechanisms governing mammary tumor subtype generation could prove critical to developing better treatments. C-Jun N-terminal kinase 2 (JNK2) is important in mammary tumorigenesis and tumor progression. Using a variety of mouse models, human breast cancer cell lines and tumor expression data, studies herein support that JNK2 inhibits cell differentiation in normal and cancer-derived mammary cells. JNK2 prevents precocious pubertal mammary development and inhibits Notch-dependent expansion of luminal cell populations. Likewise, JNK2 suppresses luminal populations in a p53-competent Polyoma Middle T-antigen tumor model where jnk2 knockout causes p53-dependent upregulation of Notch1 transcription. In a p53 knockout model, JNK2 restricts luminal populations independently of Notch1, by suppressing Brca1 expression and promoting epithelial to mesenchymal transition. JNK2 also inhibits estrogen receptor (ER) expression and confers resistance to fulvestrant, an ER inhibitor, while stimulating tumor progression. These data suggest that therapies inhibiting JNK2 in breast cancer may promote tumor differentiation, improve endocrine therapy response, and inhibit metastasis. PMID:25970777

  2. [Dot1 and Set2 Histone Methylases Control the Spontaneous and UV-Induced Mutagenesis Levels in the Saccharomyces cerevisiae Yeasts].

    Science.gov (United States)

    Kozhina, T N; Evstiukhina, T A; Peshekhonov, V T; Chernenkov, A Yu; Korolev, V G

    2016-03-01

    In the Saccharomyces cerevisiae yeasts, the DOT1 gene product provides methylation of lysine 79 (K79) of hi- stone H3 and the SET2 gene product provides the methylation of lysine 36 (K36) of the same histone. We determined that the dot1 and set2 mutants suppress the UV-induced mutagenesis to an equally high degree. The dot1 mutation demonstrated statistically higher sensitivity to the low doses of MMC than the wild type strain. The analysis of the interaction between the dot1 and rad52 mutations revealed a considerable level of spontaneous cell death in the double dot1 rad52 mutant. We observed strong suppression of the gamma-in- duced mutagenesis in the set2 mutant. We determined that the dot1 and set2 mutations decrease the sponta- neous mutagenesis rate in both single and d ouble mutants. The epistatic interaction between the dot1 and set2 mutations and almost similar sensitivity of the corresponding mutants to the different types of DNA damage allow one to conclude that both genes are involved in the control of the same DNA repair pathways, the ho- mologous-recombination-based and the postreplicative DNA repair.

  3. Variations of Histone Modification Patterns: Contributions of Inter-plant Variability and Technical Factors

    OpenAIRE

    Sylva Brabencová; Sylva Brabencová; Ivana Ihnatová; David Potěšil; Miloslava Fojtová; Miloslava Fojtová; Jiří Fajkus; Jiří Fajkus; Zbyněk Zdráhal; Zbyněk Zdráhal; Gabriela Lochmanová

    2017-01-01

    Inter-individual variability of conspecific plants is governed by differences in their genetically determined growth and development traits, environmental conditions, and adaptive responses under epigenetic control involving histone post-translational modifications. The apparent variability in histone modifications among plants might be increased by technical variation introduced in sample processing during epigenetic analyses. Thus, to detect true variations in epigenetic histone patterns as...

  4. Disturbing the histone code in leukemia: translocations and mutations affecting histone methyl transferases.

    Science.gov (United States)

    Chopra, Martin; Bohlander, Stefan K

    2015-05-01

    Leukemia is characterized by increased numbers of blasts originating from transformed early hematopoietic stem and progenitor cells. Genetic alterations are widely recognized as the main drivers of oncogenic transformation. Of considerable interest are mutations affecting the writers of epigenetic marks. In this review, we focus on histone methyltransferases--enzymes that catalyze the methylation of lysine residues in core histones. Histone methylation is a tightly controlled mechanism that is responsible for both activating as well as repressing gene expression in a site-specific manner, depending on which lysine residue is methylated. Histone methyltransferases, including MLL1, DOT1L, EZH2, and SETD2 are recurrently deregulated in human leukemia, either directly by gene mutations or balanced translocations, or indirectly as components of protein complexes that are disturbed in leukemia due to alterations of the other components in these complexes. Several small molecule inhibitors of histone methyltransferases are currently being clinically evaluated for their therapeutic potential in human leukemia. These drugs reverse some of the adverse effects of aberrant histone methylation, and can induce differentiation and cell death in leukemic blasts. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Rapid purification of recombinant histones.

    Directory of Open Access Journals (Sweden)

    Henrike Klinker

    Full Text Available The development of methods to assemble nucleosomes from recombinant histones decades ago has transformed chromatin research. Nevertheless, nucleosome reconstitution remains time consuming to this day, not least because the four individual histones must be purified first. Here, we present a streamlined purification protocol of recombinant histones from bacteria. We termed this method "rapid histone purification" (RHP as it circumvents isolation of inclusion bodies and thereby cuts out the most time-consuming step of traditional purification protocols. Instead of inclusion body isolation, whole cell extracts are prepared under strongly denaturing conditions that directly solubilize inclusion bodies. By ion exchange chromatography, the histones are purified from the extracts. The protocol has been successfully applied to all four canonical Drosophila and human histones. RHP histones and histones that were purified from isolated inclusion bodies had similar purities. The different purification strategies also did not impact the quality of octamers reconstituted from these histones. We expect that the RHP protocol can be readily applied to the purification of canonical histones from other species as well as the numerous histone variants.

  6. Biochemical Analysis of Histone Succinylation

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    Atsushi Yokoyama

    2017-01-01

    Full Text Available Posttranslational modification (PTM of proteins is used to regulate protein activity and stability. Histone PTMs are regarded as some of the most important, as they can directly regulate gene expression through chromatin reorganization. Recently, histone proteins were found to undergo succinylation, adding to other well-known PTMs such as acetylation, methylation, and phosphorylation. However, there is little information regarding the enzyme which catalyzes histone lysine succinylation. In fact, it is unclear whether this reaction is enzymatic. In this study, we tested histone succinylation activity in vitro using cell nuclear extracts of HepG2 cells. Although whole nuclear extracts did not show histone succinylation activity, we found that an SP 1.0 M KCl fraction of nuclear extracts indeed had such activity. These data offer the first direct evidence that histone succinylation is an enzymatic PTM as are other histone codes in the nucleus.

  7. Differential Effects of Ethanol on c-Jun N-Terminal Kinase, 14-3-3 Proteins, and Bax in Postnatal Day 4 and Postnatal Day 7 Rat Cerebellum

    Science.gov (United States)

    Heaton, Marieta Barrow; Paiva, Michael; Kubovic, Stacey; Kotler, Alexandra; Rogozinski, Jonathan; Swanson, Eric; Madorsky, Vladimir; Posados, Michelle

    2011-01-01

    These studies investigated ethanol effects on upstream cellular elements and interactions which contribute to Bax-related apoptosis in neonatal rat cerebellum at ages of peak ethanol sensitivity (postnatal day 4 [P4]), compared to later ages of relative resistance (P7). Analyses were made of basal levels of the pro-apoptotic c-jun N-termimal kinase (JNK), Bax, and the 14-3-3 anchoring proteins, as well as the responsiveness of these substances to ethanol at P4 versus P7. Dimerization of Bax with 14-3-3 was also investigated at the two ages following ethanol treatment, a process which sequesters Bax in the cytosol, thus inhibiting its mitochondrial translocation and disruption of the mitochondrial membrane potential. Cultured cerebellar granule cells were used to examine the protective potential of JNK inhibition on ethanol-mediated cell death. Basal levels of JNK were significantly higher at P4 than P7, but no differences in the other proteins were found. Activated JNK, and cytosolic and mitochondrially-translocated Bax were increased in P4 but not P7 animals following ethanol exposure, while protective 14-3-3 proteins were increased only at P7. Ethanol treatment resulted in decreases in Bax:14-3-3 heterodimers at P4, but not at P7. Inhibition of JNK activity in vitro provided partial protection against ethanol neurotoxicity. Thus, differential temporal vulnerability to ethanol in this CNS region correlates with differences in both levels of apoptosis-related substances (e.g., JNK), and differential cellular responsiveness, favoring apoptosis at the most sensitive age and survival at the resistant age. The upstream elements contributing to this vulnerability can be targets for future therapeutic strategies. PMID:22169498

  8. Cadmium induces apoptosis in pancreatic β-cells through a mitochondria-dependent pathway: the role of oxidative stress-mediated c-Jun N-terminal kinase activation.

    Directory of Open Access Journals (Sweden)

    Kai-Chih Chang

    Full Text Available Cadmium (Cd, one of well-known highly toxic environmental and industrial pollutants, causes a number of adverse health effects and diseases in humans. The growing epidemiological studies have suggested a possible link between Cd exposure and diabetes mellitus (DM. However, the toxicological effects and underlying mechanisms of Cd-induced pancreatic β-cell injury are still unknown. In this study, we found that Cd significantly decreased cell viability, and increased sub-G1 hypodiploid cells and annexin V-Cy3 binding in pancreatic β-cell-derived RIN-m5F cells. Cd also increased intracellular reactive oxygen species (ROS generation and malondialdehyde (MDA production and induced mitochondrial dysfunction (the loss of mitochondrial membrane potential (MMP and the increase of cytosolic cytochrome c release, the decreased Bcl-2 expression, increased p53 expression, poly (ADP-ribose polymerase (PARP cleavage, and caspase cascades, which accompanied with intracellular Cd accumulation. Pretreatment with the antioxidant N-acetylcysteine (NAC effectively reversed these Cd-induced events. Furthermore, exposure to Cd induced the phosphorylations of c-jun N-terminal kinases (JNK, extracellular signal-regulated kinases (ERK1/2, and p38-mitogen-activated protein kinase (MAPK, which was prevented by NAC. Additionally, the specific JNK inhibitor SP600125 or JNK-specific small interference RNA (si-RNA transfection suppressed Cd-induced β-cell apoptosis and related signals, but not ERK1/2 and p38-MAPK inhibitors (PD98059 and SB203580 did not. However, the JNK inhibitor or JNK-specific si-RNA did not suppress ROS generation in Cd-treated cells. These results indicate that Cd induces pancreatic β-cell death via an oxidative stress downstream-mediated JNK activation-triggered mitochondria-regulated apoptotic pathway.

  9. Tyrosine-phosphorylated caveolin-1 (Tyr-14) increases sensitivity to paclitaxel by inhibiting BCL2 and BCLxL proteins via c-Jun N-terminal kinase (JNK).

    Science.gov (United States)

    Shajahan, Ayesha N; Dobbin, Zachary C; Hickman, F Edward; Dakshanamurthy, Sivanesan; Clarke, Robert

    2012-05-18

    Paclitaxel, an anti-microtubule agent, is an effective chemotherapeutic drug in breast cancer. Nonetheless, resistance to paclitaxel remains a major clinical challenge. The need to better understand the resistant phenotype and to find biomarkers that could predict tumor response to paclitaxel is evident. In estrogen receptor α-positive (ER(+)) breast cancer cells, phosphorylation of caveolin-1 (CAV1) on Tyr-14 facilitates mitochondrial apoptosis by increasing BCL2 phosphorylation in response to low dose paclitaxel (10 nM). However, two variants of CAV1 exist: the full-length form, CAV1α (wild-type CAV1 or wtCAV1), and a truncated form, CAV1β. Only wtCAV1 has the Tyr-14 region at the N terminus. The precise cellular functions of CAV1 variants are unknown. We now show that CAV1 variants play distinct roles in paclitaxel-mediated cell death/survival. CAV1β expression is increased in paclitaxel-resistant cells when compared with sensitive cells. Expression of CAV1β in sensitive cells significantly reduces their responsiveness to paclitaxel. These activities reflect an essential role for Tyr-14 phosphorylation because wtCAV1 expression, but not a phosphorylation-deficient mutant (Y14F), inactivates BCL2 and BCLxL through activation of c-Jun N-terminal kinase (JNK). MCF-7 cells that express Y14F are resistant to paclitaxel and are resensitized by co-treatment with ABT-737, a BH3-mimetic small molecule inhibitor. Using structural homology modeling, we propose that phosphorylation on Tyr-14 enables a favorable conformation for proteins to bind to the CAV1 scaffolding domain. Thus, we highlight novel roles for CAV1 variants in cell death; wtCAV1 promotes cell death, whereas CAV1β promotes cell survival by preventing inactivation of BCL2 and BCLxL via JNK in paclitaxel-mediated apoptosis.

  10. The Green Tea Component (--Epigallocatechin-3-Gallate Sensitizes Primary Endothelial Cells to Arsenite-Induced Apoptosis by Decreasing c-Jun N-Terminal Kinase-Mediated Catalase Activity.

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    Jee-Youn Kim

    Full Text Available The green tea component (--epigallocatechin-3-gallate (EGCG has been shown to sensitize many different types of cancer cells to anticancer drug-induced apoptosis, although it protects against non-cancerous primary cells against toxicity from certain conditions such as exposure to arsenic (As or ultraviolet irradiation. Here, we found that EGCG promotes As-induced toxicity of primary-cultured bovine aortic endothelial cells (BAEC at doses in which treatment with each chemical alone had no such effect. Increased cell toxicity was accompanied by an increased condensed chromatin pattern and fragmented nuclei, cleaved poly(ADP-ribose polymerase (PARP, activity of the pro-apoptotic enzymes caspases 3, 8 and 9, and Bax translocation into mitochondria, suggesting the involvement of an apoptotic signaling pathway. Fluorescence activated cell sorting analysis revealed that compared with EGCG or As alone, combined EGCG and As (EGCG/As treatment significantly induced production of reactive oxygen species (ROS, which was accompanied by decreased catalase activity and increased lipid peroxidation. Pretreatment with N-acetyl-L-cysteine or catalase reversed EGCG/As-induced caspase activation and EC toxicity. EGCG/As also increased the phosphorylation of c-Jun N-terminal kinase (JNK, which was not reversed by catalase. However, pretreatment with the JNK inhibitor SP600125 reversed all of the observed effects of EGCG/As, suggesting that JNK may be the most upstream protein examined in this study. Finally, we also found that all the observed effects by EGCG/As are true for other types of EC tested. In conclusion, this is firstly to show that EGCG sensitizes non-cancerous EC to As-induced toxicity through ROS-mediated apoptosis, which was attributed at least in part to a JNK-activated decrease in catalase activity.

  11. Long-Term Reduction of Kappa Opioid Receptor Function by the Biased Ligand, Norbinaltorphimine, Requires c-Jun N-Terminal Kinase Activity and New Protein Synthesis in Peripheral Sensory Neurons.

    Science.gov (United States)

    Jamshidi, Raehannah J; Sullivan, Laura C; Jacobs, Blaine A; Chavera, Teresa A; Berg, Kelly A; Clarke, William P

    2016-11-01

    A single administration of the κ opioid receptor (KOR) antagonist, norbinaltorphimine (norBNI), produces long-term reduction in KOR function in heterologous expression systems and brain that is mediated by activation of c-Jun N-terminal kinase (JNK). In this study, we examined the long-term effects of norBNI on adult rat peripheral sensory neurons in vivo and ex vivo. Following a single intraplantar (i.pl.) injection of norBNI into the hind paw, peripheral KOR-mediated antinociception in the ipsilateral, but not the contralateral, hindpaw was abolished for at least 9 days. By contrast, the antinociceptive response to mu and delta opioid receptor agonists was unaltered. The long-term inhibitory effect on antinociception produced by pretreatment with norBNI required occupancy of peripheral KOR and was completely blocked by i.pl. injection of the JNK inhibitor, SP600125. In cultures of peripheral sensory neurons, norBNI activated JNK for at least 30 minutes. Furthermore, norBNI blocked KOR-mediated inhibition of adenylyl cyclase activity measured 24 hours later in a JNK-dependent manner, but did not block activation of extracellular signal-regulated kinase (ERK). The long-term inhibitory effect of norBNI on KOR function in vivo and ex vivo was blocked by inhibitors of mRNA translation, cycloheximide and rapamycin. These data suggest that in peripheral sensory neurons norBNI is a KOR-biased ligand for activation of JNK signaling, resulting in long-term blockade of some (antinociception, inhibition of adenylyl cyclase activity), but not all (ERK), KOR signaling. Importantly, norBNI elicits de novo protein synthesis in sensory neuron terminals that produces selective long-term regulation of KOR. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  12. Neuroprotection by inhibiting the c-Jun N-terminal kinase pathway after cerebral ischemia occurs independently of interleukin-6 and keratinocyte-derived chemokine (KC/CXCL1 secretion

    Directory of Open Access Journals (Sweden)

    Benakis Corinne

    2012-04-01

    Full Text Available Abstract Background Cerebral ischemia is associated with the activation of glial cells, infiltration of leukocytes and an increase in inflammatory mediators in the ischemic brain and systemic circulation. How this inflammatory response influences lesion size and neurological outcome remains unclear. D-JNKI1, an inhibitor of the c-Jun N-terminal kinase pathway, is strongly neuroprotective in animal models of stroke. Intriguingly, the protection mediated by D-JNKI1 is high even with intravenous administration at very low doses with undetectable drug levels in the brain, pointing to a systemic mode of action, perhaps on inflammation. Findings We evaluated whether D-JNKI1, administered intravenously 3 h after the onset of middle cerebral artery occlusion (MCAO, modulates secretion of the inflammatory mediators interleukin-6 and keratinocyte-derived chemokine in the plasma and from the spleen and brain at several time points after MCAO. We found an early release of both mediators in the systemic circulation followed by an increase in the brain and went on to show a later systemic increase in vehicle-treated mice. Release of interleukin-6 and keratinocyte-derived chemokine from the spleen of mice with MCAO was not significantly different from sham mice. Interestingly, the secretion of these inflammatory mediators was not altered in the systemic circulation or brain after successful neuroprotection with D-JNKI1. Conclusions We demonstrate that neuroprotection with D-JNKI1 after experimental cerebral ischemia is independent of systemic and brain release of interleukin-6 and keratinocyte-derived chemokine. Furthermore, our findings suggest that the early systemic release of interleukin-6 and keratinocyte-derived chemokine may not necessarily predict an unfavorable outcome in this model.

  13. The effects of urotensin II on migration and invasion are mediated by NADPH oxidase-derived reactive oxygen species through the c-Jun N-terminal kinase pathway in human hepatoma cells.

    Science.gov (United States)

    Li, Ying-Ying; Shi, Zheng-Ming; Yu, Xiao-Tong; Feng, Ping; Wang, Xue-Jiang

    2017-02-01

    Urotensin II (UII) is a vasoactive neuropeptide involved in migration and invasion in various cell types. However, the effects of UII on human hepatoma cells still remain unclear. The aim of this study was to investigate the role and mechanism of UII on migration and invasion in human hepatoma cells. Migration was measured by wound healing assays and a Transwell(®) methodology, and invasion was analyzed using Matrigel(®) invasion chambers. Reactive oxygen species (ROS) levels were detected using a 2', 7'-dichlorofluorescein diacetate probe, and flow cytometry, and protein expression levels were evaluated by western blotting. Cell proliferation and actin polymerization were examined using cell proliferation reagent WST-1 and F-actin immunohistochemistry staining. Exposure to UII promoted migration and invasion in hepatoma cells compared with that in cells without UII. UII also increased matrix metalloproteinase-2 (MMP2) expression in a time-independent manner. Furthermore, UII markedly enhanced ROS generation and NADPH oxidase subunit expression, and consequently facilitated the phosphorylation of c-Jun N-terminal kinase (JNK). The UT antagonist urantide or the antioxidant/NADPH oxidase inhibitor apocynin decreased UII-induced ROS production. JNK phosphorylation, migration, invasion, and MMP9/2 expression were also reversed by pretreatment with apocynin. Urantide and JNK inhibitor SP600125 abrogated migration, invasion, or MMP9/2 expression in response to UII. UII induced actin polymerization and fascin protein expression, and could be reversed by apocynin and SP600125. Exogenous UII induced migration and invasion in hepatoma cells that mainly involved NADPH oxidase-derived ROS through JNK activation. UT played an additional role in regulating hepatoma cells migration and invasion. Thus, our data suggested an important effect of UII in hepatocellular carcinoma metastasis. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Mammalian target of rapamycin complex 2 (mTORC2) controls glycolytic gene expression by regulating Histone H3 Lysine 56 acetylation.

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    Vadla, Raghavendra; Haldar, Devyani

    2017-11-16

    Metabolic reprogramming is a hallmark of cancer cells, but the mechanisms are not well understood. The mammalian target of rapamycin complex 2 (mTORC2) controls cell growth and proliferation and plays a critical role in metabolic reprogramming in glioma. mTORC2 regulates cellular processes such as cell survival, metabolism, and proliferation by phosphorylation of AGC kinases. Components of mTORC2 are shown to localize to the nucleus, but whether mTORC2 modulates epigenetic modifications to regulate gene expression is not known. Here, we identified histone H3 lysine 56 acetylation (H3K56Ac) is regulated by mTORC2 and show that global H3K56Ac levels were downregulated on mTORC2 knockdown but not on mTORC1 knockdown. mTORC2 promotes H3K56Ac in a tuberous sclerosis complex 1/2 (TSC1/2) mediated signaling pathway. We show that knockdown of sirtuin6 (SIRT6) prevented H3K56 deacetylation in mTORC2 depleted cells. Using glioma model consisting of U87EGFRvIII cells, we established that mTORC2 promotes H3K56Ac in glioma. Finally, we show that mTORC2 regulates the expression of glycolytic genes by regulating H3K56Ac levels at the promoters of these genes in glioma cells and depletion of mTOR leads to increased recruitment of SIRT6 to these promoters. Collectively, these results identify mTORC2 signaling pathway positively promotes H3K56Ac through which it may mediate metabolic reprogramming in glioma.

  15. Changes in airway histone deacetylase2 in smokers and COPD with inhaled corticosteroids: a randomized controlled trial.

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    Sukhwinder Singh Sohal

    Full Text Available The expression of HDAC2 is reported as reduced in chronic obstructive pulmonary disease (COPD. We assessed HDAC2 expression within the airways of smokers and subjects with COPD and effects of inhaled corticosteroids (ICS, using immuno-histology to contrast with previous molecular methodology. Endobronchial biopsies (ebb from current smokers with COPD (COPD-CS; n = 15, ex-smokers with COPD (COPD-ES; n = 17, smokers with normal lung function (NS; n = 16 and normal controls (NC; n = 9 were immunostained for HDAC2. A double-blinded, randomized, placebo-controlled 6 months intervention study assessed effects of ICS on HDAC2 in 34 COPD subjects. There was no difference in epithelial HDAC2 staining in all groups. There was a significant reduction in total cell numbers in the lamina propria (LP in COPD-CS and NS (p<0.05. LP cellularity correlated inversely with smoking history in COPD-CS (R = -0.8, p<0.003. HDAC2 expression increased markedly in NS (p<0.001; in contrast COPD-CS was associated with suppressed signal (p<0.03, while normal in COPD-ES. ICS did not affect HDAC2 cell staining. Our findings suggest that airway HDAC2 expression is increased in the LP by smoking itself, but is reduced in COPD. Ex-smokers have normalised HDAC2 cell expression, but ICS had no effect. The paper emphasise the pit-falls of relying on molecular data alone to define airway changes.The Australian New Zealand Clinical Trials Registry (ANZCTR. REGISTRY NUMBER: ACTRN12612001111864.

  16. Changes in Airway Histone Deacetylase2 in Smokers and COPD with Inhaled Corticosteroids: A Randomized Controlled Trial

    Science.gov (United States)

    Sohal, Sukhwinder Singh; Reid, David; Soltani, Amir; Weston, Steven; Muller, Hans Konrad; Wood-Baker, Richard; Walters, Eugene Haydn

    2013-01-01

    The expression of HDAC2 is reported as reduced in chronic obstructive pulmonary disease (COPD). We assessed HDAC2 expression within the airways of smokers and subjects with COPD and effects of inhaled corticosteroids (ICS), using immuno-histology to contrast with previous molecular methodology. Endobronchial biopsies (ebb) from current smokers with COPD (COPD-CS; n = 15), ex-smokers with COPD (COPD-ES; n = 17), smokers with normal lung function (NS; n = 16) and normal controls (NC; n = 9) were immunostained for HDAC2. A double-blinded, randomized, placebo-controlled 6 months intervention study assessed effects of ICS on HDAC2 in 34 COPD subjects. There was no difference in epithelial HDAC2 staining in all groups. There was a significant reduction in total cell numbers in the lamina propria (LP) in COPD-CS and NS (p<0.05). LP cellularity correlated inversely with smoking history in COPD-CS (R = −0.8, p<0.003). HDAC2 expression increased markedly in NS (p<0.001); in contrast COPD-CS was associated with suppressed signal (p<0.03), while normal in COPD-ES. ICS did not affect HDAC2 cell staining. Our findings suggest that airway HDAC2 expression is increased in the LP by smoking itself, but is reduced in COPD. Ex-smokers have normalised HDAC2 cell expression, but ICS had no effect. The paper emphasise the pit-falls of relying on molecular data alone to define airway changes. Clinical Trial Registration Information: Name of registry The Australian New Zealand Clinical Trials Registry (ANZCTR) Registry number ACTRN12612001111864 PMID:23717666

  17. The H3K4me3/2 histone demethylase RBR-2 controls axon guidance by repressing the actin-remodeling gene wsp-1

    DEFF Research Database (Denmark)

    Mariani, Luca; Lussi, Yvonne C.; Vandamme, Julien

    2016-01-01

    The dynamic regulation of histone modifications is important for modulating transcriptional programs during development. Aberrant H3K4 methylation is associated with neurological disorders, but how the levels and the recognition of this modification affect specific neuronal processes is unclear...

  18. The H3K4me3/2 histone demethylase RBR-2 controls axon guidance by repressing the actin-remodeling gene wsp-1

    DEFF Research Database (Denmark)

    Mariani, Luca; Lussi, Yvonne C.; Vandamme, Julien

    2016-01-01

    The dynamic regulation of histone modifications is important for modulating transcriptional programs during development. Aberrant H3K4 methylation is associated with neurological disorders, but how the levels and the recognition of this modification affect specific neuronal processes is unclear. ...

  19. Effects of orally applied butyrate bolus on histone acetylation and cytochrome P450 enzyme activity in the liver of chicken – a randomized controlled trial

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    Mátis Gábor

    2013-01-01

    Full Text Available Abstract Background Butyrate is known as histone deacetylase inhibitor, inducing histone hyperacetylation in vitro and playing a predominant role in the epigenetic regulation of gene expression and cell function. We hypothesized that butyrate, endogenously produced by intestinal microbial fermentation or applied as a nutritional supplement, might cause similar in vivo modifications in the chromatin structure of the hepatocytes, influencing the expression of certain genes and therefore modifying the activity of hepatic microsomal drug-metabolizing cytochrome P450 (CYP enzymes. Methods An animal study was carried out in chicken as a model to investigate the molecular mechanisms of butyrate’s epigenetic actions in the liver. Broiler chicks in the early post-hatch period were treated once daily with orally administered bolus of butyrate following overnight starvation with two different doses (0.25 or 1.25 g/kg body weight per day for five days. After slaughtering, cell nucleus and microsomal fractions were separated by differential centrifugation from the livers. Histones were isolated from cell nuclei and acetylation of hepatic core histones was screened by western blotting. The activity of CYP2H and CYP3A37, enzymes involved in biotransformation in chicken, was detected by aminopyrine N-demethylation and aniline-hydroxylation assays from the microsomal suspensions. Results Orally added butyrate, applied in bolus, had a remarkable impact on nucleosome structure of hepatocytes: independently of the dose, butyrate caused hyperacetylation of histone H2A, but no changes were monitored in the acetylation state of H2B. Intensive hyperacetylation of H3 was induced by the higher administered dose, while the lower dose tended to increase acetylation ratio of H4. In spite of the observed modification in histone acetylation, no significant changes were observed in the hepatic microsomal CYP2H and CYP3A37 activity. Conclusion Orally added butyrate in bolus

  20. Epigenetic therapy of cancer with histone deacetylase inhibitors

    Directory of Open Access Journals (Sweden)

    K C Lakshmaiah

    2014-01-01

    Full Text Available Epigenetics is the study of heritable alterations in gene expression that are not accompanied by the corresponding change in DNA sequence. Three interlinked epigenetic processes regulate gene expression at the level of chromatin, namely DNA methylation, nucleosomal remodeling and histone covalent modifications. Post-translational modifications that occur on certain amino acid residues of the tails of histone proteins modify chromatin structure and form the basis for "histone code". The enzymes Histone Acetyl Transferase (HAT and Histone Deacetylase (HDAC control the level of acetylation of histones and thereby alter gene expression. In many cancers, the balance between HAT and HDAC is altered. HDAC enzymes are grouped into four different classes namely Class I (HDAC1, HDAC2, HDAC3, and HDAC8, Class II (HDAC4, HDAC5, HDAC6, HDAC7, HDAC9, and HDAC10, Class III HDAC and Class IV (HDAC11. Histone Deacetylase Inhibitors (HDACI exert anticancer activity by promoting acetylation of histones as well as by promoting acetylation of non-histone protein substrates. The effects of HDACI on gene transcription are complex. They cause cell cycle arrest, inhibit DNA repair, induce apoptosis and acetylate non histone proteins causing downstream alterations in gene expression. HDACI are a diverse group of compounds, which vary in structure, biological activity, and specificity. In general, HDACIs contain a zinc-binding domain, a capping group, and a straight chain linker connecting the two. They are classified into four classes namely short chain fatty acids, hydroxamic acids, cyclic peptides and synthetic benzamides. This review describes the clinical utility of HDACI as monotherapy as well as combination therapy with other treatment modalities such as chemotherapy and radiotherapy. Adverse effects and shortcomings of treatment with HDACI are also discussed in detail.

  1. MicroRNA-181a Regulates Apoptosis and Autophagy Process in Parkinson's Disease by Inhibiting p38 Mitogen-Activated Protein Kinase (MAPK)/c-Jun N-Terminal Kinases (JNK) Signaling Pathways.

    Science.gov (United States)

    Liu, Ying; Song, Yanfeng; Zhu, Xiaotun

    2017-04-02

    BACKGROUND microRNA (miR)-181a has been reported to be downregulated in Parkinson's disease (PD), but the regulatory mechanism of miR-181a on neuron apoptosis and autophagy is still poorly understood. We aimed to investigate the neuroprotective effects of miR-181a on PD in vitro. MATERIAL AND METHODS Human SK-N-SH neuroblastoma cells were incubated with different concentrations of 1-methyl-4-phenylpyridinium ion (MPP+) to induce the PD model. The expression of miR-181a was then analyzed. After transfection with miR-181a mimic or scramble following MPP+ treatment, the expression of autophagy protein markers (LC3II, LC3I, and Beclin 1) and p38 mitogen-activated protein kinase (MAPK)/c-Jun N-terminal kinases (JNK) signaling proteins (p-p38, p38, p-JNK, and JNK) and cell apoptosis were detected. Furthermore, the cells were transfected with miR-181a inhibitor and cultured in the presence or absence of p38 inhibitor SB203582 or JNK inhibitor SP600125, and the cell apoptosis was tested again. RESULTS The expression of miR-181a was gradually decreased with the increase of MPP+ concentration (P<0.05, P<0.01, or P<0.001). Overexpression of miR-181a significantly decreased the LC3II/LC3I ratio, Beclin 1 expression, cell apoptosis, and the expression of p-p38 and p-JNK compared to the MPP+ + miR-181a scramble group (all P<0.05). In addition, we observed that SB203582 or SP600125 showed no effects on cell apoptosis, but the effects of miR-181a inhibitor on cell apoptosis were reversed by administration of SB203582 or SP600125 compared to the scramble group (P<0.05). CONCLUSIONS Our results suggest that miR-181a regulates apoptosis and autophagy in PD by inhibiting the p38 MAPK/JNK pathway.

  2. The drosophila T-box transcription factor midline functions within Insulin/Akt and c-Jun-N terminal kinase stress-reactive signaling pathways to regulate interommatial bristle formation and cell survival.

    Science.gov (United States)

    Chen, Q Brent; Das, Sudeshna; Visic, Petra; Buford, Kendrick D; Zong, Yan; Buti, Wisam; Odom, Kelly R; Lee, Hannah; Leal, Sandra M

    2015-05-01

    We recently reported that the T-box transcription factor midline (mid) functions within the Notch-Delta signaling pathway to specify sensory organ precursor (SOP) cell fates in early-staged pupal eye imaginal discs and to suppress apoptosis (Das et al.). From genetic and allelic modifier screens, we now report that mid interacts with genes downstream of the insulin receptor(InR)/Akt, c-Jun-N-terminal kinase (JNK) and Notch signaling pathways to regulate interommatidial bristle (IOB) formation and cell survival. One of the most significant mid-interacting genes identified from the modifier screen is dFOXO, a transcription factor exhibiting a nucleocytoplasmic subcellular distribution pattern. In common with dFOXO, we show that Mid exhibits a nucleocytoplasmic distribution pattern within WT third-instar larval (3(o)L) tissue homogenates. Because dFOXO is a stress-responsive factor, we assayed the effects of either oxidative or metabolic stress responses on modifying the mid mutant phenotype which is characterized by a 50% loss of IOBs within the adult compound eye. While metabolic starvation stress does not affect the mid mutant phenotype, either 1 mM paraquat or 20% coconut oil, oxidative stress inducers, partially suppresses the mid mutant phenotype resulting in a significant recovery of IOBs. Another significant mid-interacting gene we identified is groucho (gro). Mid and Gro are predicted to act as corepressors of the enhancer-of-split gene complex downstream of Notch. Immunolabeling WT and dFOXO null 3(o)L eye-antennal imaginal discs with anti-Mid and anti-Engrailed (En) antibodies indicate that dFOXO is required to activate Mid and En expression within photoreceptor neurons of the eye disc. Taken together, these studies show that Mid and dFOXO serve as critical effectors of cell fate specification and survival within integrated Notch, InR/dAkt, and JNK signaling pathways during 3(o)L and pupal eye imaginal disc development. Copyright © 2015 Elsevier Ireland

  3. The histone demethylases JMJD1A and JMJD2B are transcriptional targets of hypoxia-inducible factor HIF

    DEFF Research Database (Denmark)

    Beyer, Sophie; Kristensen, Malene Maag; Jensen, Kim Steen

    2008-01-01

    Posttranslational histone modifications serve to store epigenetic information and control both nucleosome assembly and recruitment of non-histone proteins. Histone methylation occurs on arginine and lysine residues and is involved in the regulation of gene transcription. A dynamic control of thes...

  4. Histone methyltransferases in cancer

    DEFF Research Database (Denmark)

    Albert, Mareike; Helin, Kristian

    2009-01-01

    Cancer is perceived as a heterogeneous group of diseases that is characterized by aberrant patterns of gene expression. In the last decade, an increasing amount of data has pointed to a key role for epigenetic alterations in human cancer. In this review, we focus on a subclass of epigenetic...... regulators, namely histone methyltransferases (HMTs). Several HMTs have been linked to different types of cancer; however, in most cases we only have limited knowledge regarding the molecular mechanisms by which the HMTs contribute to disease development. We summarize the current knowledge regarding some...

  5. Histone deacetylases and atherosclerosis.

    Science.gov (United States)

    Zheng, Xia-xia; Zhou, Tian; Wang, Xin-An; Tong, Xiao-hong; Ding, Jia-wang

    2015-06-01

    Atherosclerosis is the most common pathological process that leads to cardiovascular diseases, a disease of large- and medium-sized arteries that is characterized by a formation of atherosclerotic plaques consisting of necrotic cores, calcified regions, accumulated modified lipids, smooth muscle cells (SMCs), endothelial cells, leukocytes, and foam cells. Recently, the question about how to suppress the occurrence of atherosclerosis and alleviate the progress of cardiovascular disease becomes the hot topic. Accumulating evidence suggests that histone deacetylases(HDACs) play crucial roles in arteriosclerosis. This review summarizes the effect of HDACs and HDAC inhibitors(HDACi) on the progress of atherosclerosis. Copyright © 2015. Published by Elsevier Ireland Ltd.

  6. Histone-modifying enzymes, histone modifications and histone chaperones in nucleosome assembly: Lessons learned from Rtt109 histone acetyltransferases

    Science.gov (United States)

    Dahlin, Jayme L; Chen, Xiaoyue; Walters, Michael A.; Zhang, Zhiguo

    2015-01-01

    During DNA replication, nucleosomes ahead of replication forks are disassembled to accommodate replication machinery. Following DNA replication, nucleosomes are then reassembled onto replicated DNA using both parental and newly synthesized histones. This process, termed DNA replication-coupled nucleosome assembly (RCNA), is critical for maintaining genome integrity and for the propagation of epigenetic information, dysfunctions of which have been implicated in cancers and aging. In recent years, it has been shown that RCNA is carefully orchestrated by a series of histone modifications, histone chaperones and histone-modifying enzymes. Interestingly, many features of RCNA are also found in processes involving DNA replication-independent nucleosome assembly like histone exchange and gene transcription. In yeast, histone H3 lysine K56 acetylation (H3K56ac) is found in newly synthesized histone H3 and is critical for proper nucleosome assembly and for maintaining genomic stability. The histone acetyltransferase (HAT) regulator of Ty1 transposition 109 (Rtt109) is the sole enzyme responsible for H3K56ac in yeast. Much research has centered on this particular histone modification and histone-modifying enzyme. This Critical Review summarizes much of our current understanding of nucleosome assembly and highlights many important insights learned from studying Rtt109 HATs in fungi. We highlight some seminal features in nucleosome assembly conserved in mammalian systems and describe some of the lingering questions in the field. Further studying fungal and mammalian chromatin assembly may have important public health implications, including deeper understandings of human cancers and aging as well as the pursuit of novel anti-fungal therapies. PMID:25365782

  7. High-resolution genome-wide mapping of histone modifications.

    Science.gov (United States)

    Roh, Tae-young; Ngau, Wing Chi; Cui, Kairong; Landsman, David; Zhao, Keji

    2004-08-01

    The expression patterns of eukaryotic genomes are controlled by their chromatin structure, consisting of nucleosome subunits in which DNA of approximately 146 bp is wrapped around a core of 8 histone molecules. Post-translational histone modifications play an essential role in modifying chromatin structure. Here we apply a combination of SAGE and chromatin immunoprecipitation (ChIP) protocols to determine the distribution of hyperacetylated histones H3 and H4 in the Saccharomyces cerevisiae genome. We call this approach genome-wide mapping technique (GMAT). Using GMAT, we find that the highest acetylation levels are detected in the 5' end of a gene's coding region, but not in the promoter. Furthermore, we show that the histone acetyltransferase, GCN5p, regulates H3 acetylation in the promoter and 5' end of the coding regions. These findings indicate that GMAT should find valuable applications in mapping target sites of chromatin-modifying enzymes.

  8. Epigenetic targeting of histone deacetylase: therapeutic potential in Parkinson's disease?

    Science.gov (United States)

    Harrison, Ian F; Dexter, David T

    2013-10-01

    Parkinson's disease (PD) is the most common movement disorder affecting more than 4million people worldwide. The primary motor symptoms of the disease are due to degeneration of dopaminergic nigrostriatal neurons. Dopamine replacement therapies have therefore revolutionised disease management by partially controlling these symptoms. However these drugs can produce debilitating side effects when used long term and do not protect degenerating neurons against death. Recent evidence has highlighted a pathological imbalance in PD between the acetylation and deacetylation of the histone proteins around which deoxyribonucleic acid (DNA) is coiled, in favour of excessive histone deacetylation. This mechanism of adding/removing acetyl groups to histone lysine residues is one of many epigenetic regulatory processes which control the expression of genes, many of which will be essential for neuronal survival. Hence, such epigenetic modifications may have a pathogenic role in PD. It has therefore been hypothesised that if this pathological imbalance can be corrected with the use of histone deacetylase inhibiting agents then neurodegeneration observed in PD can be ameliorated. This article will review the current literature with regard to epigenetic changes in PD and the use of histone deacetylase inhibitors (HDACIs) in PD: examining the evidence of the neuroprotective effects of numerous HDACIs in cellular and animal models of Parkinsonian cell death. Ultimately answering the question: does epigenetic targeting of histone deacetylases hold therapeutic potential in PD? Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Chromatin replication and histone dynamics

    DEFF Research Database (Denmark)

    Alabert, Constance; Jasencakova, Zuzana; Groth, Anja

    2017-01-01

    organization into chromatin. We reveal how specialized replication-coupled mechanisms rapidly assemble newly synthesized DNA into nucleosomes, while the complete restoration of chromatin organization including histone marks is a continuous process taking place throughout the cell cycle. Because failure...

  10. Histone chaperone networks shaping chromatin function

    DEFF Research Database (Denmark)

    Hammond, Colin; Strømme, Caroline Bianchi; Huang, Hongda

    2017-01-01

    The association of histones with specific chaperone complexes is important for their folding, oligomerization, post-translational modification, nuclear import, stability, assembly and genomic localization. In this way, the chaperoning of soluble histones is a key determinant of histone availabili...... chaperone network and via co-chaperone complexes to match histone supply with demand, thereby promoting proper nucleosome assembly and maintaining epigenetic information by recycling modified histones evicted from chromatin....

  11. The histone code of Toxoplasma gondii comprises conserved and unique posttranslational modifications.

    Science.gov (United States)

    Nardelli, Sheila C; Che, Fa-Yun; Silmon de Monerri, Natalie C; Xiao, Hui; Nieves, Edward; Madrid-Aliste, Carlos; Angel, Sergio O; Sullivan, William J; Angeletti, Ruth H; Kim, Kami; Weiss, Louis M

    2013-12-10

    changes in gene expression, and the control mechanisms for these transitions have not been elucidated. Important mechanisms that are involved in the control of gene expression are the epigenetic modifications that have been identified in several eukaryotes. T. gondii has a full complement of histone-modifying enzymes, histones, and variants. In this paper, we identify over a hundred PTM and a full repertoire of PTM combinations for T. gondii histones, providing the first large-scale characterization of the T. gondii histone code and an essential initial step for understanding how epigenetic modifications affect gene expression and other processes in this organism.

  12. Epigenetic histone code and autoimmunity.

    Science.gov (United States)

    Dieker, Jürgen; Muller, Sylviane

    2010-08-01

    The multiple inter-dependent post-translational modifications of histones represent fine regulators of chromatin dynamics. These covalent modifications, including phosphorylation, acetylation, ubiquitination, deimination, and methylation, affect therefore the numerous processes involving chromatin, such as replication, repair, transcription, genome stability, and cell death. Specific enzymes introducing modified residues in histones are precisely regulated, and a single amino acid residue can be subjected to a single or several, independent modifications. Disruption of histone post-translational modifications perturbs the pattern of gene expression, which may result in disease manifestations. It has become evident in recent years that apoptosis-modified histones exert a central role in the induction of autoimmunity, for example in systemic lupus erythematosus and rheumatoid arthritis. Certain histone post-translational modifications are linked to cell death (apoptotic and non-apoptotic cell death) and might be involved in lupus in the activation of normally tolerant lymphocyte subpopulations. In this review, we discuss how these modifications can affect the antigenicity and immunogenicity of histones with potential consequences in the pathogenesis of autoimmune diseases.

  13. IBM1, a JmjC domain-containing histone demethylase, is involved in the regulation of RNA-directed DNA methylation through the epigenetic control of RDR2 and DCL3 expression in Arabidopsis.

    Science.gov (United States)

    Fan, Di; Dai, Yan; Wang, Xuncheng; Wang, Zhenjie; He, Hang; Yang, Hongchun; Cao, Ying; Deng, Xing Wang; Ma, Ligeng

    2012-10-01

    Small RNA-directed DNA methylation (RdDM) is an important epigenetic pathway in Arabidopsis that controls the expression of multiple genes and several developmental processes. RNA-DEPENDENT RNA POLYMERASE 2 (RDR2) and DICER-LIKE 3 (DCL3) are necessary factors in 24-nt small interfering RNA (siRNA) biogenesis, which is part of the RdDM pathway. Here, we found that Increase in BONSAI Methylation 1 (IBM1), a conserved JmjC family histone demethylase, is directly associated with RDR2 and DCL3 chromatin. The mutation of IBM1 induced the hypermethylation of H3K9 and DNA non-CG sites within RDR2 and DCL3, which repressed their expression. A genome-wide analysis suggested that the reduction in RDR2 and DCL3 expression affected siRNA biogenesis in a locus-specific manner and disrupted RdDM-directed gene repression. Together, our results suggest that IBM1 regulates gene expression through two distinct pathways: direct association to protect genes from silencing by preventing the coupling of histone and DNA methylation, and indirect silencing of gene expression through RdDM-directed repression.

  14. Histone Deacetylase Inhibitors as Anticancer Drugs

    Directory of Open Access Journals (Sweden)

    Tomas Eckschlager

    2017-07-01

    Full Text Available Carcinogenesis cannot be explained only by genetic alterations, but also involves epigenetic processes. Modification of histones by acetylation plays a key role in epigenetic regulation of gene expression and is controlled by the balance between histone deacetylases (HDAC and histone acetyltransferases (HAT. HDAC inhibitors induce cancer cell cycle arrest, differentiation and cell death, reduce angiogenesis and modulate immune response. Mechanisms of anticancer effects of HDAC inhibitors are not uniform; they may be different and depend on the cancer type, HDAC inhibitors, doses, etc. HDAC inhibitors seem to be promising anti-cancer drugs particularly in the combination with other anti-cancer drugs and/or radiotherapy. HDAC inhibitors vorinostat, romidepsin and belinostat have been approved for some T-cell lymphoma and panobinostat for multiple myeloma. Other HDAC inhibitors are in clinical trials for the treatment of hematological and solid malignancies. The results of such studies are promising but further larger studies are needed. Because of the reversibility of epigenetic changes during cancer development, the potency of epigenetic therapies seems to be of great importance. Here, we summarize the data on different classes of HDAC inhibitors, mechanisms of their actions and discuss novel results of preclinical and clinical studies, including the combination with other therapeutic modalities.

  15. Histone Deacetylase Inhibitors as Anticancer Drugs.

    Science.gov (United States)

    Eckschlager, Tomas; Plch, Johana; Stiborova, Marie; Hrabeta, Jan

    2017-07-01

    Carcinogenesis cannot be explained only by genetic alterations, but also involves epigenetic processes. Modification of histones by acetylation plays a key role in epigenetic regulation of gene expression and is controlled by the balance between histone deacetylases (HDAC) and histone acetyltransferases (HAT). HDAC inhibitors induce cancer cell cycle arrest, differentiation and cell death, reduce angiogenesis and modulate immune response. Mechanisms of anticancer effects of HDAC inhibitors are not uniform; they may be different and depend on the cancer type, HDAC inhibitors, doses, etc. HDAC inhibitors seem to be promising anti-cancer drugs particularly in the combination with other anti-cancer drugs and/or radiotherapy. HDAC inhibitors vorinostat, romidepsin and belinostat have been approved for some T-cell lymphoma and panobinostat for multiple myeloma. Other HDAC inhibitors are in clinical trials for the treatment of hematological and solid malignancies. The results of such studies are promising but further larger studies are needed. Because of the reversibility of epigenetic changes during cancer development, the potency of epigenetic therapies seems to be of great importance. Here, we summarize the data on different classes of HDAC inhibitors, mechanisms of their actions and discuss novel results of preclinical and clinical studies, including the combination with other therapeutic modalities.

  16. Genome-wide analysis of regions similar to promoters of histone genes

    KAUST Repository

    Chowdhary, Rajesh

    2010-05-28

    Background: The purpose of this study is to: i) develop a computational model of promoters of human histone-encoding genes (shortly histone genes), an important class of genes that participate in various critical cellular processes, ii) use the model so developed to identify regions across the human genome that have similar structure as promoters of histone genes; such regions could represent potential genomic regulatory regions, e.g. promoters, of genes that may be coregulated with histone genes, and iii/ identify in this way genes that have high likelihood of being coregulated with the histone genes.Results: We successfully developed a histone promoter model using a comprehensive collection of histone genes. Based on leave-one-out cross-validation test, the model produced good prediction accuracy (94.1% sensitivity, 92.6% specificity, and 92.8% positive predictive value). We used this model to predict across the genome a number of genes that shared similar promoter structures with the histone gene promoters. We thus hypothesize that these predicted genes could be coregulated with histone genes. This hypothesis matches well with the available gene expression, gene ontology, and pathways data. Jointly with promoters of the above-mentioned genes, we found a large number of intergenic regions with similar structure as histone promoters.Conclusions: This study represents one of the most comprehensive computational analyses conducted thus far on a genome-wide scale of promoters of human histone genes. Our analysis suggests a number of other human genes that share a high similarity of promoter structure with the histone genes and thus are highly likely to be coregulated, and consequently coexpressed, with the histone genes. We also found that there are a large number of intergenic regions across the genome with their structures similar to promoters of histone genes. These regions may be promoters of yet unidentified genes, or may represent remote control regions that

  17. Histone code or not? Combinatorial pattern analyses of histone modifications

    Science.gov (United States)

    Zang, Chongzhi; Peng, Weiqun; Wang, Zhibin; Schones, Dustin E.; Barski, Artem; Cuddapah, Suresh; Cui, Kairong; Roh, Tae-Young; Zhao, Keji; Rosenfeld, Jeffrey; Zhang, Michael

    2008-03-01

    Eukaryotic genomes are organized into chromatin, the structure of which plays critical role in the program of gene expression. Chromatin structure and function is regulated by a myriad of posttranslational modifications on histone tails of the nucleosomes, the fundamental unit of chromatin. It remains unclear how different modifications interact. Based on high- resolution genomic maps of close to 40 histone methylations and acetylations in human T-cells obtained experimentally by ChIP- Seq technique, we investigated the combinatorial patterns of histone modifications at gene promoter regions. We found that a very limited number of patterns dominate. Modifications within a pattern are strongly correlated and each pattern is associated with a distinct gene expression distribution. Our results suggest that it is the patterns rather than the individual modifications that affect the downstream readout.

  18. Cracking the enigmatic linker histone code.

    Science.gov (United States)

    Godde, James S; Ura, Kiyoe

    2008-03-01

    Recently, the existence of a 'histone code' has been proposed to explain the link between the covalent chemical modification of histone proteins and the epigenetic regulation of gene activity. Although the role of the four 'core' histones has been extensively studied, little is known about the involvement of the linker histone, histone H1 and its variants, in this code. For many years, few sites of chemical modification had been mapped in linker histones, but this has changed recently with the use of functional proteomic techniques, principally mass spectrometry, to characterize these modifications. The functionality of many of these sites, however, remains to be determined.

  19. Excess free histone H3 localizes to centrosomes for proteasome-mediated degradation during mitosis in metazoans.

    Science.gov (United States)

    Wike, Candice L; Graves, Hillary K; Wason, Arpit; Hawkins, Reva; Gopalakrishnan, Jay; Schumacher, Jill; Tyler, Jessica K

    2016-08-17

    The cell tightly controls histone protein levels in order to achieve proper packaging of the genome into chromatin, while avoiding the deleterious consequences of excess free histones. Our accompanying study has shown that a histone modification that loosens the intrinsic structure of the nucleosome, phosphorylation of histone H3 on threonine 118 (H3 T118ph), exists on centromeres and chromosome arms during mitosis. Here, we show that H3 T118ph localizes to centrosomes in humans, flies, and worms during all stages of mitosis. H3 abundance at the centrosome increased upon proteasome inhibition, suggesting that excess free histone H3 localizes to centrosomes for degradation during mitosis. In agreement, we find ubiquitinated H3 specifically during mitosis and within purified centrosomes. These results suggest that targeting of histone H3 to the centrosome for proteasome-mediated degradation is a novel pathway for controlling histone supply, specifically during mitosis.

  20. Histone variants: emerging players in cancer biology

    Science.gov (United States)

    Vardabasso, Chiara; Hasson, Dan; Ratnakumar, Kajan; Chung, Chi-Yeh; Duarte, Luis F.

    2014-01-01

    Histone variants are key players in shaping chromatin structure, and, thus, in regulating fundamental cellular processes such as chromosome segregation and gene expression. Emerging evidence points towards a role for histone variants in contributing to tumor progression, and, recently, the first cancer-associated mutation in a histone variant-encoding gene was reported. In addition, genetic alterations of the histone chaperones that specifically regulate chromatin incorporation of histone variants are rapidly being uncovered in numerous cancers. Collectively, these findings implicate histone variants as potential drivers of cancer initiation and/or progression, and, therefore, targeting histone deposition or the chromatin remodeling machinery may be of therapeutic value. Here, we review the mammalian histone variants of the H2A and H3 families in their respective cellular functions, and their involvement in tumor biology. PMID:23652611

  1. Histone deacetylase inhibition as an alternative strategy against invasive aspergillosis

    Directory of Open Access Journals (Sweden)

    Frederic eLamoth

    2015-02-01

    Full Text Available Invasive aspergillosis (IA is a life-threatening infection due to Aspergillus fumigatus and other Aspergillus spp. Drugs targeting the fungal cell membrane (triazoles, amphotericin B or cell wall (echinocandins are currently the sole therapeutic options against IA. Their limited efficacy and the emergence of resistance warrant the identification of new antifungal targets. Histone deacetylases (HDACs are enzymes responsible of the deacetylation of lysine residues of core histones, thus controlling chromatin remodeling and transcriptional activation. HDACs also control the acetylation and activation status of multiple non-histone proteins, including the heat shock protein 90 (Hsp90, an essential molecular chaperone for fungal virulence and antifungal resistance. This review provides an overview of the different HDACs in Aspergillus spp. as well as their respective contribution to total HDAC activity, fungal growth, stress responses, and virulence. The potential of HDAC inhibitors, currently under development for cancer therapy, as novel alternative antifungal agents against IA is discussed.

  2. The histone acetyltransferase p300 inhibitor C646 reduces pro-inflammatory gene expression and inhibits histone deacetylases

    NARCIS (Netherlands)

    van den Bosch, Thea; Boichenko, Alexander; Leus, Niek G J; Ourailidou, Maria Eleni; Wapenaar, Hannah; Rotili, Dante; Mai, Antonello; Imhof, Axel; Bischoff, Rainer; Haisma, Hidde J; Dekker, Frank J

    2016-01-01

    Lysine acetylations are reversible posttranslational modifications of histone and non-histone proteins that play important regulatory roles in signal transduction cascades and gene expression. Lysine acetylations are regulated by histone acetyltransferases as writers and histone deacetylases as

  3. Disruption of Methionine Metabolism in Drosophila melanogaster Impacts Histone Methylation and Results in Loss of Viability

    Directory of Open Access Journals (Sweden)

    Mengying Liu

    2016-01-01

    Full Text Available Histone methylation levels, which are determined by the action of both histone demethylases and methyltransferases, impact multiple biological processes by affecting gene expression activity. Methionine metabolism generates the major methyl donor S-adenosylmethionine (SAM for histone methylation. The functions of methionine metabolic enzymes in regulating biological processes as well as the interaction between the methionine pathway and histone methylation, however, are still not fully understood. Here, we report that reduced levels of some enzymes involved in methionine metabolism and histone demethylases lead to lethality as well as wing development and cell proliferation defects in Drosophila melanogaster. Additionally, disruption of methionine metabolism can directly affect histone methylation levels. Reduction of little imaginal discs (LID histone demethylase, but not lysine-specific demethylase 2 (KDM2 demethylase, is able to counter the effects on histone methylation due to reduction of SAM synthetase (SAM-S. Taken together, these results reveal an essential role of key enzymes that control methionine metabolism and histone methylation. Additionally, these findings are an indication of a strong connection between metabolism and epigenetics.

  4. Natural variation of histone modification and its impact on gene expression in the rat genome

    NARCIS (Netherlands)

    Rintisch, Carola; Heinig, Matthias; Bauerfeind, Anja; Schafer, Sebastian; Mieth, Christin; Patone, Giannino; Hummel, Oliver; Chen, Wei; Cook, Stuart; Cuppen, Edwin; Colomé Tatché, Maria; Johannes, Frank; Jansen, Ritsert C; Neil, Helen; Werner, Michel; Pravenec, Michal; Vingron, Martin; Hubner, Norbert

    Histone modifications are epigenetic marks that play fundamental roles in many biological processes including the control of chromatin-mediated regulation of gene expression. Little is known about interindividual variability of histone modification levels across the genome and to what extent they

  5. Rho-kinase signaling controls nucleocytoplasmic shuttling of class IIa Histone Deacetylase (HDAC7) and transcriptional activation of orphan nuclear receptor NR4A1

    Energy Technology Data Exchange (ETDEWEB)

    Compagnucci, Claudia; Barresi, Sabina [Unit of Molecular Medicine for Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, Bambino Gesù Children’s Hospital, IRCCS, Rome (Italy); Petrini, Stefania [Research Laboratories, Confocal Microscopy Core Facility, Bambino Gesù Children’s Hospital, IRCCS, Rome (Italy); Bertini, Enrico [Unit of Molecular Medicine for Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, Bambino Gesù Children’s Hospital, IRCCS, Rome (Italy); Zanni, Ginevra, E-mail: ginevra.zanni@opbg.net [Unit of Molecular Medicine for Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, Bambino Gesù Children’s Hospital, IRCCS, Rome (Italy)

    2015-04-03

    Rho-kinase (ROCK) has been well documented to play a key role in RhoA-induced actin remodeling. ROCK activation results in myosin light chain (MLC) phosphorylation either by direct action on MLC kinase (MLCK) or by inhibition of MLC phosphatase (MLCP), modulating actin–myosin contraction. We found that inhibition of the ROCK pathway in induced pluripotent stem cells, leads to nuclear export of HDAC7 and transcriptional activation of the orphan nuclear receptor NR4A1 while in cells with constitutive ROCK hyperactivity due to loss of function of the RhoGTPase activating protein Oligophrenin-1 (OPHN1), the orphan nuclear receptor NR4A1 is downregulated. Our study identify a new target of ROCK signaling via myosin phosphatase subunit (MYPT1) and Histone Deacetylase (HDAC7) at the nuclear level and provide new insights in the cellular functions of ROCK. - Highlights: • ROCK regulates nucleocytoplasmic shuttling of HDAC7 via phosphorylation of MYPT1. • Nuclear export of HDAC7 and upregulation of NR4A1 occurs with low ROCK activity. • High levels of ROCK activity due to OPHN1 loss of function downregulate NR4A1.

  6. Knockdown of selenocysteine-specific elongation factor in Amblyomma maculatum alters the pathogen burden of Rickettsia parkeri with epigenetic control by the Sin3 histone deacetylase corepressor complex.

    Directory of Open Access Journals (Sweden)

    Steven W Adamson

    Full Text Available Selenocysteine is the 21st naturally-occurring amino acid. Selenoproteins have diverse functions and many remain uncharacterized, but they are typically associated with antioxidant activity. The incorporation of selenocysteine into the nascent polypeptide chain recodes the TGA stop codon and this process depends upon a number of essential factors including the selenocysteine elongation factor (SEF. The transcriptional expression of SEF did not change significantly in tick midguts throughout the blood meal, but decreased in salivary glands to 20% at the end of the fast feeding phase. Since selenoprotein translation requires this specialized elongation factor, we targeted this gene for knockdown by RNAi to gain a global view of the role selenoproteins play in tick physiology. We found no significant differences in tick engorgement and embryogenesis but detected no antioxidant capacity in tick saliva. The transcriptional profile of selenoproteins in R. parkeri-infected Amblyomma maculatum revealed declined activity of selenoprotein M and catalase and increased activity of selenoprotein O, selenoprotein S, and selenoprotein T. Furthermore, the pathogen burden was significantly altered in SEF-knockdowns. We then determined the global impact of SEF-knockdown by RNA-seq, and mapped huge shifts in secretory gene expression that could be the result of downregulation of the Sin3 histone deacetylase corepressor complex.

  7. Diversity and Divergence of Dinoflagellate Histone Proteins.

    Science.gov (United States)

    Marinov, Georgi K; Lynch, Michael

    2015-12-08

    Histone proteins and the nucleosomal organization of chromatin are near-universal eukaroytic features, with the exception of dinoflagellates. Previous studies have suggested that histones do not play a major role in the packaging of dinoflagellate genomes, although several genomic and transcriptomic surveys have detected a full set of core histone genes. Here, transcriptomic and genomic sequence data from multiple dinoflagellate lineages are analyzed, and the diversity of histone proteins and their variants characterized, with particular focus on their potential post-translational modifications and the conservation of the histone code. In addition, the set of putative epigenetic mark readers and writers, chromatin remodelers and histone chaperones are examined. Dinoflagellates clearly express the most derived set of histones among all autonomous eukaryote nuclei, consistent with a combination of relaxation of sequence constraints imposed by the histone code and the presence of numerous specialized histone variants. The histone code itself appears to have diverged significantly in some of its components, yet others are conserved, implying conservation of the associated biochemical processes. Specifically, and with major implications for the function of histones in dinoflagellates, the results presented here strongly suggest that transcription through nucleosomal arrays happens in dinoflagellates. Finally, the plausible roles of histones in dinoflagellate nuclei are discussed. Copyright © 2016 Marinov and Lynch.

  8. Diversity and Divergence of Dinoflagellate Histone Proteins

    Directory of Open Access Journals (Sweden)

    Georgi K. Marinov

    2016-02-01

    Full Text Available Histone proteins and the nucleosomal organization of chromatin are near-universal eukaroytic features, with the exception of dinoflagellates. Previous studies have suggested that histones do not play a major role in the packaging of dinoflagellate genomes, although several genomic and transcriptomic surveys have detected a full set of core histone genes. Here, transcriptomic and genomic sequence data from multiple dinoflagellate lineages are analyzed, and the diversity of histone proteins and their variants characterized, with particular focus on their potential post-translational modifications and the conservation of the histone code. In addition, the set of putative epigenetic mark readers and writers, chromatin remodelers and histone chaperones are examined. Dinoflagellates clearly express the most derived set of histones among all autonomous eukaryote nuclei, consistent with a combination of relaxation of sequence constraints imposed by the histone code and the presence of numerous specialized histone variants. The histone code itself appears to have diverged significantly in some of its components, yet others are conserved, implying conservation of the associated biochemical processes. Specifically, and with major implications for the function of histones in dinoflagellates, the results presented here strongly suggest that transcription through nucleosomal arrays happens in dinoflagellates. Finally, the plausible roles of histones in dinoflagellate nuclei are discussed.

  9. A PSHaver for centromeric histones.

    Science.gov (United States)

    Folco, H Diego; Desai, Arshad

    2010-11-12

    In this issue of Molecular Cell, Hewawasam et al. (2010) and Ranjitkar et al. (2010) identify and characterize Psh1, an E3 ubiquitin ligase that specifically targets the centromeric histone Cse4 in budding yeast and limits its misincorporation at noncentromeric regions. Copyright © 2010 Elsevier Inc. All rights reserved.

  10. Drug Addiction and Histone Code Alterations.

    Science.gov (United States)

    Kim, Hee-Dae; Call, Tanessa; Magazu, Samantha; Ferguson, Deveroux

    2017-01-01

    Acute and prolonged exposure to drugs of abuse induces changes in gene expression, synaptic function, and neural plasticity in brain regions involved in reward. Numerous genes are involved in this process, and persistent changes in gene expression coincide with epigenetic histone modifications and DNA methylation. Histone modifications are attractive regulatory mechanisms, which can encode complex environmental signals in the genome of postmitotic cells, like neurons. Recently, it has been demonstrated that specific histone modifications are involved in addiction-related gene regulatory mechanisms, by a diverse set of histone-modifying enzymes and readers. These histone modifiers and readers may prove to be valuable pharmacological targets for effective treatments for drug addiction.

  11. Histone deacetylase inhibitor MS-275 augments expression of a subset of IFN-γ-regulated genes in Toxoplasma gondii-infected macrophages but does not improve parasite control.

    Science.gov (United States)

    Sumpf, Kristina; Nast, Roswitha; Downie, Bryan; Salinas, Gabriela; Lüder, Carsten G K

    2017-09-01

    Toxoplasma gondii is a ubiquitous apicomplexan parasite of mammals and birds and an important pathogen of humans. IFN-γ is the major mediator of host resistance against T. gondii but intriguingly, parasite-infected host cells including macrophages are severely impaired to respond to IFN-γ due to defective transcriptional activation of target genes. Here, we tested the possibility that the impaired responsiveness of T. gondii-infected macrophages to IFN-γ can be restored by inhibiting histone deacetylases (HDACs) using the class I-specific inhibitor MS-275. Treatment of RAW264.7 cells with MS-275 indeed increased MHC class II surface expression in infected and non-infected cells and largely abolished the inhibition of IFN-γ-regulated MHC class II expression exerted by T. gondii. Genome-wide transcriptome profiling revealed that MS-275 increased mean mRNA levels of IFN-γ-regulated genes particularly in non-infected macrophages. Transcript levels of 33% of IFN-γ secondary response genes but only those of a few primary response genes were also increased by MS-275 in T. gondii-infected cells. Importantly, the unresponsiveness of parasite-infected cells to IFN-γ was however not abolished by MS-275. Furthermore, MS-275 also up-regulated several anti-inflammatory cytokines or signaling molecules in T. gondii-infected macrophages. It additionally regulated expression of more than 2500 genes in non-infected macrophages expression of which was surprisingly counteracted by prior infection with T. gondii. FACS analysis and immunofluorescence microscopy revealed that MS-275 did not considerably diminish the number of parasite-positive cells or the intracellular replication in macrophages stimulated or not with IFN-γ. Thus, a supportive therapy using MS-275 appears inappropriate for treatment of toxoplasmosis. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Low Proteolytic Clipping of Histone H3 in Cervical Cancer

    Science.gov (United States)

    Sandoval-Basilio, Jorge; Serafín-Higuera, Nicolás; Reyes-Hernandez, Octavio D.; Serafín-Higuera, Idanya; Leija-Montoya, Gabriela; Blanco-Morales, Magali; Sierra-Martínez, Monica; Ramos-Mondragon, Roberto; García, Silvia; López-Hernández, Luz Berenice; Yocupicio-Monroy, Martha; Alcaraz-Estrada, Sofia L.

    2016-01-01

    Chromatin in cervical cancer (CC) undergoes chemical and structural changes that alter the expression pattern of genes. Recently, a potential mechanism, which regulates gene expression at transcriptional levels is the proteolytic clipping of histone H3. However, until now this process in CC has not been reported. Using HeLa cells as a model of CC and human samples from patients with CC, we identify that the H3 cleavage was lower in CC compared with control tissue. Additionally, the histone H3 clipping was performed by serine and aspartyl proteases in HeLa cells. These results suggest that histone H3 clipping operates as part of post-translational modification system in CC. PMID:27698925

  13. Identification and Interrogation of Combinatorial Histone Modifications

    Directory of Open Access Journals (Sweden)

    Kelly R Karch

    2013-12-01

    Full Text Available Histone proteins are dynamically modified to mediate a variety of cellular processes including gene transcription, DNA damage repair, and apoptosis. Regulation of these processes occurs through the recruitment of non-histone proteins to chromatin by specific combinations of histone post-translational modifications (PTMs. Mass spectrometry has emerged as an essential tool to discover and quantify histone PTMs both within and between samples in an unbiased manner. Developments in mass spectrometry that allow for characterization of large histone peptides or intact protein has made it possible to determine which modifications occur simultaneously on a single histone polypeptide. A variety of techniques from biochemistry, biophysics, and chemical biology have been employed to determine the biological relevance of discovered combinatorial codes. This review first describes advancements in the field of mass spectrometry that have facilitated histone PTM analysis and then covers notable approaches to probe the biological relevance of these modifications in their nucleosomal context.

  14. Novel insights into the plant histone code: lessons from ORC1.

    Science.gov (United States)

    Sanchez, María de la Paz; Gutierrez, Crisanto

    2009-05-16

    Gene expression control depends on the combinatorial presence of various posttranslational modifications of the N-terminal tail of histones, among which acetylation and methylation of lysine residues are the most conspicuous. Effector proteins have been identified that recognize specific histone modifications and transduce the information of the histone code into different degrees of chromatin compaction in either facultative or constitutive heterochromatin. In addition, they also impinge on transcriptional control, either activation or repression, of euchromatic genes. However, a large variety of effector proteins lead to different gene expression readouts. This is complicated by accumulating evidence showing that the consequences of various histone modifications differ among animals and plants. Given the conservation of histone marks, and histone modification enzymes, this has evolutionary implications as to how they are interpreted differently in different organisms. One example that illustrates such diversity of the histone code is the large subunit of the origin recognition complex, ORC1. In plants, but not in yeast and animal cells, ORC1 functions as a transcriptional activator of a subset of target genes and is a plant homeodomain (PHD)-containing protein that binds to histone H3K4me3 residues.

  15. A PHD in histone language

    Science.gov (United States)

    Chandrika, Nulu Naga Prafulla; Sundaravelpandian, Kalaipandian; Schmidt, Wolfgang

    2013-01-01

    Post-translational modifications of core histones are important for various DNA-templated processes such as transcription and repair. We recently reported that the ALFIN LIKE 6 (AL6) gene, identified in a forward genetic screen, is critical for phosphate deficiency-induced root hair formation and several other processes associated with the regulation of cellular phosphate homeostasis. AL6 contains a Plant Homeo Domain (PHD) finger that can bind to trimethylated lysine 4 of histone H3 (H3K4me3). Homozygous mutants defective in AL6 expression form very short root hairs under phosphate-deficient conditions, presumably caused by altered expression of putative primary and secondary down-stream targets of AL6. In this Addendum, we speculate about possible roles of AL6, H3K4 trimethylation and other chromatin modifications in the adaptation of plants to low phosphate availability. PMID:23531693

  16. The significance, development and progress of high-throughput combinatorial histone code analysis.

    Science.gov (United States)

    Young, Nicolas L; Dimaggio, Peter A; Garcia, Benjamin A

    2010-12-01

    The physiological state of eukaryotic DNA is chromatin. Nucleosomes, which consist of DNA in complex with histones, are the fundamental unit of chromatin. The post-translational modifications (PTMs) of histones play a critical role in the control of gene transcription, epigenetics and other DNA-templated processes. It has been known for several years that these PTMs function in concert to allow for the storage and transduction of highly specific signals through combinations of modifications. This code, the combinatorial histone code, functions much like a bar code or combination lock providing the potential for massive information content. The capacity to directly measure these combinatorial histone codes has mostly been laborious and challenging, thus limiting efforts often to one or two samples. Recently, progress has been made in determining such information quickly, quantitatively and sensitively. Here we review both the historical and recent progress toward routine and rapid combinatorial histone code analysis.

  17. Structural insight into histone recognition by the ING PHD fingers.

    Science.gov (United States)

    Champagne, Karen S; Kutateladze, Tatiana G

    2009-05-01

    The Inhibitor of Growth (ING) tumor suppressors are implicated in oncogenesis, control of DNA damage repair, cellular senescence and apoptosis. All members of the ING family contain unique amino-terminal regions and a carboxy-terminal plant homeodomain (PHD) finger. While the amino-terminal domains associate with a number of protein effectors including distinct components of histone deacetylase (HDAC) and histone acetyltransferase (HAT) complexes, the PHD finger binds strongly and specifically to histone H3 trimethylated at lysine 4 (H3K4me3). In this review we describe the molecular mechanism of H3K4me3 recognition by the ING1-5 PHD fingers, analyze the determinants of the histone specificity and compare the biological activities and structures within subsets of PHD fingers. The atomic-resolution structures of the ING PHD fingers in complex with a H3K4me3 peptide reveal that the histone tail is bound in a large and deep binding site encompassing nearly one-third of the protein surface. An extensive network of intermolecular hydrogen bonds, hydrophobic and cation-pi contacts, and complementary surface interactions coordinate the first six residues of the H3K4me3 peptide. The trimethylated Lys4 occupies an elongated groove, formed by the highly conserved aromatic and hydrophobic residues of the PHD finger, whereas the adjacent groove accommodates Arg2. The two grooves are connected by a narrow channel, the small size of which defines the PHD finger's specificity, excluding interactions with other modified histone peptides. Binding of the ING PHD fingers to H3K4me3 plays a critical role in regulating chromatin acetylation. The ING proteins function as tethering molecules that physically link the HDAC and HAT enzymatic complexes to chromatin. In this review we also highlight progress recently made in understanding the molecular basis underlying biological and tumorigenic activities of the ING tumor suppressors.

  18. Distribution of introns in fungal histone genes.

    Directory of Open Access Journals (Sweden)

    Choong-Soo Yun

    Full Text Available Saccharomycotina and Taphrinomycotina lack intron in their histone genes, except for an intron in one of histone H4 genes of Yarrowia lipolytica. On the other hand, Basidiomycota and Perizomycotina have introns in their histone genes. We compared the distributions of 81, 47, 79, and 98 introns in the fungal histone H2A, H2B, H3, and H4 genes, respectively. Based on the multiple alignments of the amino acid sequences of histones, we identified 19, 13, 31, and 22 intron insertion sites in the histone H2A, H2B, H3, and H4 genes, respectively. Surprisingly only one hot spot of introns in the histone H2A gene is shared between Basidiomycota and Perizomycotina, suggesting that most of introns of Basidiomycota and Perizomycotina were acquired independently. Our findings suggest that the common ancestor of Ascomycota and Basidiomycota maybe had a few introns in the histone genes. In the course of fungal evolution, Saccharomycotina and Taphrinomycotina lost the histone introns; Basidiomycota and Perizomycotina acquired other introns independently. In addition, most of the introns have sequence similarity among introns of phylogenetically close species, strongly suggesting that horizontal intron transfer events between phylogenetically distant species have not occurred recently in the fungal histone genes.

  19. Distribution of introns in fungal histone genes.

    Science.gov (United States)

    Yun, Choong-Soo; Nishida, Hiromi

    2011-01-27

    Saccharomycotina and Taphrinomycotina lack intron in their histone genes, except for an intron in one of histone H4 genes of Yarrowia lipolytica. On the other hand, Basidiomycota and Perizomycotina have introns in their histone genes. We compared the distributions of 81, 47, 79, and 98 introns in the fungal histone H2A, H2B, H3, and H4 genes, respectively. Based on the multiple alignments of the amino acid sequences of histones, we identified 19, 13, 31, and 22 intron insertion sites in the histone H2A, H2B, H3, and H4 genes, respectively. Surprisingly only one hot spot of introns in the histone H2A gene is shared between Basidiomycota and Perizomycotina, suggesting that most of introns of Basidiomycota and Perizomycotina were acquired independently. Our findings suggest that the common ancestor of Ascomycota and Basidiomycota maybe had a few introns in the histone genes. In the course of fungal evolution, Saccharomycotina and Taphrinomycotina lost the histone introns; Basidiomycota and Perizomycotina acquired other introns independently. In addition, most of the introns have sequence similarity among introns of phylogenetically close species, strongly suggesting that horizontal intron transfer events between phylogenetically distant species have not occurred recently in the fungal histone genes.

  20. Profiling Changes in Histone Post-translational Modifications by Top-Down Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Mowei; Wu, Si; Stenoien, David L.; Zhang, Zhaorui; Connolly, Lanelle; Freitag, Michael; Pasa-Tolic, Ljiljana

    2016-11-11

    Top-down mass spectrometry is a valuable tool for charactering post-translational modifications on histones for understanding of gene control and expression. In this protocol, we describe a top-down workflow using liquid chromatography coupled to mass spectrometry for fast global profiling of changes in histone proteoforms between a wild-type and a mutant of a fungal species. The proteoforms exhibiting different abundances can be subjected to further targeted studies by other mass spectrometric or biochemical assays. This method can be generally adapted for preliminary screening for changes in histone modifications between samples such as wild-type vs. mutant, and control vs. disease.

  1. Histone Acetylation in Fungal Pathogens of Plants

    Directory of Open Access Journals (Sweden)

    Junhyun Jeon

    2014-03-01

    Full Text Available Acetylation of histone lysine residues occurs in different organisms ranging from yeast to plants and mammals for the regulation of diverse cellular processes. With the identification of enzymes that create or reverse this modification, our understanding on histone acetylation has expanded at an amazing pace during the last two decades. In fungal pathogens of plants, however, the importance of such modification has only just begun to be appreciated in the recent years and there is a dearth of information on how histone acetylation is implicated in fungal pathogenesis. This review covers the current status of research related to histone acetylation in plant pathogenic fungi and considers relevant findings in the interaction between fungal pathogens and host plants. We first describe the families of histone acetyltransferases and deacetylases. Then we provide the cases where histone acetylation was investigated in the context of fungal pathogenesis. Finally, future directions and perspectives in epigenetics of fungal pathogenesis are discussed.

  2. Basic nuclear processes affected by histone acetyltransferases and histone deacetylase inhibitors

    NARCIS (Netherlands)

    Legartová, Soňa; Stixová, Lenka; Strnad, Hynek; Kozubek, Stanislav; Martinet, Nadine; Dekker, Frank J; Franek, Michal; Bártová, Eva

    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

  3. Histone displacement during nucleotide excision repair

    DEFF Research Database (Denmark)

    Dinant, C.; Bartek, J.; Bekker-Jensen, S.

    2012-01-01

    chromatin. The condensed nature of chromatin inhibits many DNA metabolizing activities, including NER. In order to promote efficient repair, detection of a lesion not only has to activate the NER pathway but also chromatin remodeling. In general, such remodeling is thought on the one hand to precede NER...... of histone variants and histone displacement (including nucleosome sliding). Here we review current knowledge, and speculate about current unknowns, regarding those chromatin remodeling activities that physically displace histones before, during and after NER....

  4. Peptide microarrays to interrogate the "histone code".

    Science.gov (United States)

    Rothbart, Scott B; Krajewski, Krzysztof; Strahl, Brian D; Fuchs, Stephen M

    2012-01-01

    Histone posttranslational modifications (PTMs) play a pivotal role in regulating the dynamics and function of chromatin. Supported by an increasing body of literature, histone PTMs such as methylation and acetylation function together in the context of a "histone code," which is read, or interpreted, by effector proteins that then drive a functional output in chromatin (e.g., gene transcription). A growing number of domains that interact with histones and/or their PTMs have been identified. While significant advances have been made in our understanding of how these domains interact with histones, a wide number of putative histone-binding motifs have yet to be characterized, and undoubtedly, novel domains will continue to be discovered. In this chapter, we provide a detailed method for the construction of combinatorially modified histone peptides, microarray fabrication using these peptides, and methods to characterize the interaction of effector proteins, antibodies, and the substrate specificity of histone-modifying enzymes. We discuss these methods in the context of other available technologies and provide a user-friendly approach to enable the exploration of histone-protein-enzyme interactions and function. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. The histone genes cluster in Rhynchosciara americana and its transcription profile in salivary glands during larval development

    Directory of Open Access Journals (Sweden)

    Fábio Siviero

    Full Text Available Abstract In this work we report the characterization of the Rhynchosciara americana histone genes cluster nucleotide sequence. It spans 5,131 bp and contains the four core histones and the linker histone H1. Putative control elements were detected. We also determined the copy number of the tandem repeat unit through quantitative PCR, as well as the unequivocal chromosome location of this unique locus in chromosome A band 13. The data were compared with histone clusters from the genus Drosophila, which are the closest known homologues.

  6. A new approach combining LC-MS and multivariate statistical analysis for revealing changes in histone modification levels.

    Science.gov (United States)

    Bilgraer, Raphaël; Gillet, Sylvie; Gil, Sophie; Evain-Brion, Danièle; Laprévote, Olivier

    2014-11-01

    While acting upon chromatin compaction, histone post-translational modifications (PTMs) are involved in modulating gene expression through histone-DNA affinity and protein-protein interactions. These dynamic and environment-sensitive modifications are constitutive of the histone code that reflects the transient transcriptional state of the chromatin. Here we describe a global screening approach for revealing epigenetic disruption at the histone level. This original approach enables fast and reliable relative abundance comparison of histone PTMs and variants in human cells within a single LC-MS experiment. As a proof of concept, we exposed BeWo human choriocarcinoma cells to sodium butyrate (SB), a universal histone deacetylase (HDAC) inhibitor. Histone acid-extracts (n = 45) equally representing 3 distinct classes, Control, 1 mM and 2.5 mM SB, were analysed using ultra-performance liquid chromatography coupled with a hybrid quadrupole time-of-flight mass spectrometer (UPLC-QTOF-MS). Multivariate statistics allowed us to discriminate control from treated samples based on differences in their mass spectral profiles. Several acetylated and methylated forms of core histones emerged as markers of sodium butyrate treatment. Indeed, this untargeted histonomic approach could be a useful exploratory tool in many cases of xenobiotic exposure when histone code disruption is suspected.

  7. Cell shape regulates global histone acetylation in human mammaryepithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Le Beyec, Johanne; Xu, Ren; Lee, Sun-Young; Nelson, Celeste M.; Rizki, Aylin; Alcaraz, Jordi; Bissell, Mina J.

    2007-02-28

    Extracellular matrix (ECM) regulates cell morphology and gene expression in vivo; these relationships are maintained in three-dimensional (3D) cultures of mammary epithelial cells. In the presence of laminin-rich ECM (lrECM), mammary epithelial cells round up and undergo global histone deacetylation, a process critical for their functional differentiation. However, it remains unclear whether lrECM-dependent cell rounding and global histone deacetylation are indeed part of a common physical-biochemical pathway. Using 3D cultures as well as nonadhesive and micropatterned substrata, here we showed that the cell 'rounding' caused by lrECM was sufficient to induce deacetylation of histones H3 and H4 in the absence of biochemical cues. Microarray and confocal analysis demonstrated that this deacetylation in 3D culture is associated with a global increase in chromatin condensation and a reduction in gene expression. Whereas cells cultured on plastic substrata formed prominent stress fibers, cells grown in 3D lrECM or on micropatterns lacked these structures. Disruption of the actin cytoskeleton with cytochalasin D phenocopied the lrECM-induced cell rounding and histone deacetylation. These results reveal a novel link between ECM-controlled cell shape and chromatin structure, and suggest that this link is mediated by changes in the actin cytoskeleton.

  8. Targeting Histone Acetylation: Readers and Writers in Leukemia and Cancer.

    Science.gov (United States)

    Benton, Christopher B; Fiskus, Warren; Bhalla, Kapil N

    Chromatin packaging of DNA provides a framework for transcriptional regulation. Modifications to DNA and histone proteins in nucleosomes lead to conformational changes, alterations in the recruitment of transcriptional complexes, and ultimately modulation of gene expression. We provide a focused review of control mechanisms that help modulate the activation and deactivation of gene transcription specifically through histone acetylation writers and readers in cancer. The chemistry of these modifications is subject to clinically actionable targeting, including state-of-the-art strategies to inhibit basic oncogenic mechanisms related to histone acetylation. Although discussed in the context of acute leukemia, the concepts of acetylation writers and readers are not cell-type-specific and are generalizable to other cancers. We review the challenges and resistance mechanisms encountered to date in the development of such therapeutics and postulate how such challenges may be overcome. Because these fundamental cellular mechanisms are dysregulated in cancer biology, continued research and in-depth understanding of histone acetylation reading and writing are desired to further define optimal therapeutic strategies to affect gene activity to target cancer effectively.

  9. Implication of Posttranslational Histone Modifications in Nucleotide Excision Repair

    Directory of Open Access Journals (Sweden)

    Shisheng Li

    2012-09-01

    Full Text Available Histones are highly alkaline proteins that package and order the DNA into chromatin in eukaryotic cells. Nucleotide excision repair (NER is a conserved multistep reaction that removes a wide range of generally bulky and/or helix-distorting DNA lesions. Although the core biochemical mechanism of NER is relatively well known, how cells detect and repair lesions in diverse chromatin environments is still under intensive research. As with all DNA-related processes, the NER machinery must deal with the presence of organized chromatin and the physical obstacles it presents. A huge catalogue of posttranslational histone modifications has been documented. Although a comprehensive understanding of most of these modifications is still lacking, they are believed to be important regulatory elements for many biological processes, including DNA replication and repair, transcription and cell cycle control. Some of these modifications, including acetylation, methylation, phosphorylation and ubiquitination on the four core histones (H2A, H2B, H3 and H4 or the histone H2A variant H2AX, have been found to be implicated in different stages of the NER process. This review will summarize our recent understanding in this area.

  10. Lysine acetylome profiling uncovers novel histone deacetylase substrate proteins in Arabidopsis

    DEFF Research Database (Denmark)

    Hartl, Markus; Füßl, Magdalena; Boersema, Paul J.

    2017-01-01

    91 new acetylated candidate proteins other than histones, which are potential substrates of the RPD3/HDA1-like histone deacetylases in Arabidopsis, of which at least 30 of these proteins function in nucleic acid binding. Furthermore, our analysis revealed that histone deacetylase 14 (HDA14......) is the first organellar-localized RPD3/HDA1 class protein found to reside in the chloroplasts and that the majority of its protein targets have functions in photosynthesis. Finally, the analysis of HDA14 loss-of-function mutants revealed that the activation state of RuBisCO is controlled by lysine acetylation...

  11. Activation of p38 mitogen-activated protein kinase (p38 MAPK), extracellular signal-regulated kinase (ERK) and c-jun N-terminal kinase (JNK) during hypoxia in cerebral cortical nuclei of guinea pig fetus at term: role of nitric oxide.

    Science.gov (United States)

    Maulik, Dev; Ashraf, Qazi M; Mishra, Om P; Delivoria-Papadopoulos, Maria

    2008-07-04

    Previously we have shown that cerebral tissue hypoxia results in generation of nitric oxide (NO) free radicals as well as increased expression of mitogen-activated protein kinase like extracellular signal-regulated kinase (ERK) and c-jun N-terminal kinase (JNK). The present study tested the hypothesis that administration of l-nitro-l-arginine methyl ester (L-NAME), a NOS inhibitor, prior to hypoxia prevents the hypoxia-induced activation of p38 mitogen-activated protein kinase (p38 MAPK), extracellular signal-regulated kinase (ERK) and c-jun N-terminal kinase (JNK) and in the cerebral cortex of the term guinea pig fetus. To test this hypothesis normoxic (Nx, n=6), hypoxic (Hx, n=7) and hypoxic pretreated with l-NAME (Hx+L-NAME, n=6) guinea pig fetuses at 60 days gestation were studied to determine the phosphorylated p38, ERK and JNK. Hypoxia was induced by exposing pregnant guinea pigs to FiO2 of 0.07 for 1h. l-NAME (30mg/kg i.p.) was administered to pregnant mothers 60min prior to hypoxia. Cerebral tissue hypoxia was documented biochemically by determining the tissue levels of ATP and phosphocreatine (PCr). Neuronal nuclei were isolated, purified and proteins separated using 12% SDS-PAGE, and then probed with specific phosphorylated ERK, JNK and p38 antibodies. Protein bands were detected by enhanced chemiluminescence, analyzed by imaging densitometry and expressed as absorbance (ODxmm2). The relative level of p-p38 was 51.41+/-9.80 (Nx), 173.67+/-3.63 (Hx), 58.56+/-3.40 (Hx+L-NAME), phypoxia decreased the relative level of phosphorylated p38, ERK and JNK at term gestation. Since a NOS inhibitor prevented the hypoxia-induced phosphorylation of p38, ERK and JNK, we conclude that the hypoxia-induced activation of p38, ERK and JNK in the cerebral cortical nuclei of guinea pig fetus at term is NO-mediated. We speculate that NO-mediated modification of cysteine residue leading to inhibition of MAP kinase phosphatases results in increased activation of p38, ERK and JNK

  12. Ethanol precipitation analysis of thymus histone

    NARCIS (Netherlands)

    Bijvoet, P.

    1957-01-01

    An analytical ethanol precipitation technique, similar to 's salting-out procedure, was used for the characterisation of whole thymus histone and the products obtained by preparative ethanol fractionation. The analysis was carried out at —5° C and pH 6.5. Whole histone prepared according to et al.,

  13. Histone acetyl transferases as emerging drug targets

    NARCIS (Netherlands)

    Dekker, Frank J.; Haisma, Hidde J.

    2009-01-01

    Post-translational modifications, such as acetylation or phosphorylation, play a crucial role in the regulation of gene transcription in eukaryotes. Different subtypes of histone acetyl transferases (HATs) catalyze the acetylation of histones on specific lysine residues. A potential role of HATs in

  14. Histone modifications: Cycling with chromosomal replication

    DEFF Research Database (Denmark)

    Thon, Genevieve

    2008-01-01

    Histone modifications tend to be lost during chromosome duplication. Several recent studies suggest that the RNA interference pathway becomes active during the weakened transcriptional repression occurring at centromeres in S phase, resulting in the re-establishment of histone modifications that ...

  15. Histone variants in plant transcriptional regulation.

    Science.gov (United States)

    Jiang, Danhua; Berger, Frédéric

    2017-01-01

    Chromatin based organization of eukaryotic genome plays a profound role in regulating gene transcription. Nucleosomes form the basic subunits of chromatin by packaging DNA with histone proteins, impeding the access of DNA to transcription factors and RNA polymerases. Exchange of histone variants in nucleosomes alters the properties of nucleosomes and thus modulates DNA exposure during transcriptional regulation. Growing evidence indicates the important function of histone variants in programming transcription during developmental transitions and stress response. Here we review how histone variants and their deposition machineries regulate the nucleosome stability and dynamics, and discuss the link between histone variants and transcriptional regulation in plants. This article is part of a Special Issue entitled: Plant Gene Regulatory Mechanisms and Networks, edited by Dr. Erich Grotewold and Dr. Nathan Springer. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Acetylated histone H3 increases nucleosome dissociation

    Science.gov (United States)

    Simon, Marek; Manohar, Mridula; Ottesen, Jennifer; Poirier, Michael

    2009-03-01

    Chromatin's basic unit structure is the nucleosome, i.e. genomic DNA wrapped around a particular class of proteins -- histones -- which due to their physical hindrance, block vital biological processes, such as DNA repair, DNA replication, and RNA transcription. Histone post-translational modifications, which are known to exist in vivo, are hypothesized to regulate these biological processes by directly altering DNA-histone interactions and thus nucleosome structure and stability. Using magnetic tweezers technique we studied the acetylation of histone H3 in the dyad region, i.e. at K115 and K122, on reconstituted arrays of nucleosomes under constant external force. Based on the measured increase in the probability of dissociation of modified nucleosomes, we infer that this double modification could facilitate histone chaperone mediated nucleosome disassembly in vivo.

  17. Structural genomics of histone tail recognition.

    Science.gov (United States)

    Wang, Minghua; Mok, Man Wai; Harper, Hong; Lee, Wen Hwa; Min, Jinrong; Knapp, Stefan; Oppermann, Udo; Marsden, Brian; Schapira, Matthieu

    2010-10-15

    The structural genomics of histone tail recognition web server is an open access resource that presents within mini articles all publicly available experimental structures of histone tails in complex with human proteins. Each article is composed of interactive 3D slides that dissect the structural mechanism underlying the recognition of specific sequences and histone marks. A concise text html-linked to interactive graphics guides the reader through the main features of the interaction. This resource can be used to analyze and compare binding modes across multiple histone recognition modules, to evaluate the chemical tractability of binding sites involved in epigenetic signaling and design small molecule inhibitors. http://www.thesgc.org/resources/histone_tails/ matthieu.schapira@utoronto.ca Supplementary data are available at Bioinformatics online.

  18. Histone deacetylase 8 in neuroblastoma tumorigenesis.

    Science.gov (United States)

    Oehme, Ina; Deubzer, Hedwig E; Wegener, Dennis; Pickert, Diana; Linke, Jan-Peter; Hero, Barbara; Kopp-Schneider, Annette; Westermann, Frank; Ulrich, Scott M; von Deimling, Andreas; Fischer, Matthias; Witt, Olaf

    2009-01-01

    The effects of pan-histone deacetylase (HDAC) inhibitors on cancer cells have shown that HDACs are involved in fundamental tumor biological processes such as cell cycle control, differentiation, and apoptosis. However, because of the unselective nature of these compounds, little is known about the contribution of individual HDAC family members to tumorigenesis and progression. The purpose of this study was to evaluate the role of individual HDACs in neuroblastoma tumorigenesis. We have investigated the mRNA expression of all HDAC1-11 family members in a large cohort of primary neuroblastoma samples covering the full spectrum of the disease. HDACs associated with disease stage and survival were subsequently functionally evaluated in cell culture models. Only HDAC8 expression was significantly correlated with advanced disease and metastasis and down-regulated in stage 4S neuroblastoma associated with spontaneous regression. High HDAC8 expression was associated with poor prognostic markers and poor overall and event-free survival. The knockdown of HDAC8 resulted in the inhibition of proliferation, reduced clonogenic growth, cell cycle arrest, and differentiation in cultured neuroblastoma cells. The treatment of neuroblastoma cell lines as well as short-term-culture neuroblastoma cells with an HDAC8-selective small-molecule inhibitor inhibited cell proliferation and clone formation, induced differentiation, and thus reproduced the HDAC8 knockdown phenotype. Global histone 4 acetylation was not affected by HDAC8 knockdown or by selective inhibitor treatment. Our data point toward an important role of HDAC8 in neuroblastoma pathogenesis and identify this HDAC family member as a specific drug target for the differentiation therapy of neuroblastoma.

  19. Histones and their modifications in ovarian cancer – drivers of disease and therapeutic targets

    Directory of Open Access Journals (Sweden)

    Deborah Joy Marsh

    2014-06-01

    Full Text Available Epithelial ovarian cancer has the highest mortality of the gynecological malignancies. High grade serous epithelial ovarian cancer (SEOC is the most common subtype, with the majority of women presenting with advanced disease where 5 year survival is around 25%. Platinum-based chemotherapy in combination with paclitaxel remains the most effective treatment despite platinum therapies being introduced almost 40 years ago. Advances in molecular medicine are underpinning new strategies for the treatment of cancer. Major advances have been made by international initiatives to sequence cancer genomes. For SEOC, with the exception of TP53 that is mutated in virtually 100% of these tumors, there is no other gene mutated at high frequency. There is extensive copy number variation, as well as changes in methylation patterns that will influence gene expression. To date, the role of histones and their post-translational modifications in ovarian cancer is a relatively understudied field. Post-translational histone modifications play major roles in gene expression as they direct the configuration of chromatin and so access by transcription factors. Histone modifications include methylation, acetylation and monoubiquitination, with involvement of enzymes including histone methyl transferases (HMTases, histone acetyltransferases/deacetylases and ubiquitin ligases/deubiquitinases respectively. Complexes such as the Polycomb Repressive Complex also play roles in the control of histone modifications and more recently roles for long non-coding (lnc RNA and microRNAs (miRNAs are emerging. Epigenomic-based therapies targeting histone modifications are being developed and offer new approaches for the treatment of ovarian cancer. Here we discuss histone modifications and their aberrant regulation in malignancy and specifically in ovarian cancer. We review current and upcoming histone-based therapies that have the potential to inform and improve treatment strategies for

  20. Post-translational Modifications Regulate Class IIa Histone Deacetylase (HDAC) Function in Health and Disease*

    OpenAIRE

    Mathias, Rommel A.; Amanda J Guise; Cristea, Ileana M.

    2015-01-01

    Class IIa histone deacetylases (HDACs4, -5, -7, and -9) modulate the physiology of the human cardiovascular, musculoskeletal, nervous, and immune systems. The regulatory capacity of this family of enzymes stems from their ability to shuttle between nuclear and cytoplasmic compartments in response to signal-driven post-translational modification. Here, we review the current knowledge of modifications that control spatial and temporal histone deacetylase functions by regulating subcellular loca...

  1. Reduced Histone H3 Acetylation in CD4+ T Lymphocytes: Potential Mechanism of Latent Autoimmune Diabetes in Adults

    Directory of Open Access Journals (Sweden)

    Xi-yu Liu

    2015-01-01

    Full Text Available Aims. Latent autoimmune diabetes in adults (LADA is the result of gene-environment interactions. Histone acetylation regulates gene expression and maybe interpret how environmental factors modify LADA. Hence, we studied the histone acetylation patterns in CD4+ T lymphocytes from LADA patients. Methods. Blood CD4+ T lymphocytes from 28 patients with LADA and 28 healthy controls were obtained to detect histone H3 acetylation and H4 acetylation. The gene expression of histone acetyltransferases (P300 and CREBBP and histone deacetylases (HDAC1, HDAC2, and HDAC7 was measured by real-time polymerase chain reaction (RT-PCR. Results. Compared to healthy controls, reduced global H3 acetylation was observed in LADA patients’ CD4+ T lymphocytes (P<0.05. Global level of H4 acetylation was not statistically different. Among LADA, CD4+ T lymphocytes H3 acetylation was associated with glycosylated hemoglobin (HbA1c and GADA titer. Compared to healthy controls, the expression of histone acetyltransferases CREBBP in LADA patients was downregulated, and the expression of histone deacetylases HDAC1 and HDAC7 was upregulated. Conclusion. A concerted downregulation of histone H3 acetylation was found in CD4+ T lymphocytes of LADA patients, and this might provide evidence of a novel epigenetic explanation for the pathogenesis of LADA and its complications.

  2. Targeting Histone Abnormality in Triple Negative Breast Cancer

    Science.gov (United States)

    2016-08-01

    Zawacki K, Podewils LJ, Cohen G and McCorkle R. Exercise manages fatigue during breast cancer treatment: a randomized controlled trial. Psycho...27249683. 301. Bhargava R, Davidson NE. "Take two"? The role of second opinions for breast biopsy specimens. Bmj . 2016;353:i3256, 2016. PMID: 27339037...deacetylase regulates muscle differentiation. Nature 2000; 408: 106–111. 18 Martin M, Kettmann R, Dequiedt F. Class IIa histone deacetylases: conducting

  3. Histone deacetylases (HDACs and brain function

    Directory of Open Access Journals (Sweden)

    Claude-Henry Volmar

    2015-01-01

    Full Text Available Modulation of gene expression is a constant and necessary event for mammalian brain function. An important way of regulating gene expression is through the remodeling of chromatin, the complex of DNA, and histone proteins around which DNA wraps. The “histone code hypothesis” places histone post-translational modifications as a significant part of chromatin remodeling to regulate transcriptional activity. Acetylation of histones by histone acetyl transferases and deacetylation by histone deacetylases (HDACs at lysine residues are the most studied histone post-translational modifications in cognition and neuropsychiatric diseases. Here, we review the literature regarding the role of HDACs in brain function. Among the roles of HDACs in the brain, studies show that they participate in glial lineage development, learning and memory, neuropsychiatric diseases, and even rare neurologic diseases. Most HDACs can be targeted with small molecules. However, additional brain-penetrant specific inhibitors with high central nervous system exposure are needed to determine the cause-and-effect relationship between individual HDACs and brain-associated diseases.

  4. Comparative effects of histone deacetylases inhibitors and resveratrol on Trypanosoma cruzi replication, differentiation, infectivity and gene expression

    Directory of Open Access Journals (Sweden)

    Vanina A. Campo

    2017-04-01

    Full Text Available Histone post-translational modification, mediated by histone acetyltransferases and deacetylases, is one of the most studied factors affecting gene expression. Recent data showing differential histone acetylation states during the Trypanosoma cruzi cell cycle suggest a role for epigenetics in the control of this process. As a starting point to study the role of histone deacetylases in the control of gene expression and the consequences of their inhibition and activation in the biology of T. cruzi, two inhibitors for different histone deacetylases: trichostatin A for class I/II and sirtinol for class III and the activator resveratrol for class III, were tested on proliferative and infective forms of this parasite. The two inhibitors tested caused histone hyperacetylation whereas resveratrol showed the opposite effect on both parasite forms, indicating that a biologically active in vivo level of these compounds was achieved. Histone deacetylase inhibitors caused life stage-specific effects, increasing trypomastigotes infectivity and blocking metacyclogenesis. Moreover, these inhibitors affected specific transcript levels, with sirtinol causing the most pronounced change. On the other hand, resveratrol showed strong anti-parasitic effects. This compound diminished epimastigotes growth, promoted metacyclogenesis, reduced in vitro infection and blocked differentiation and/or replication of intracellular amastigotes. In conclusion, the data presented here supports the notion that these compounds can modulate T. cruzi gene expression, differentiation, infection and histones deacetylase activity. Furthermore, among the compounds tested in this study, the results point to Resveratrol as promising trypanocidal drug candidate.

  5. Histone Deacetylase (HDAC) Inhibitors - emerging roles in neuronal memory, learning, synaptic plasticity and neural regeneration.

    Science.gov (United States)

    Ganai, Shabir Ahmad; Ramadoss, Mahalakshmi; Mahadevan, Vijayalakshmi

    2016-01-01

    Epigenetic regulation of neuronal signalling through histone acetylation dictates transcription programs that govern neuronal memory, plasticity and learning paradigms. Histone Acetyl Transferases (HATs) and Histone Deacetylases (HDACs) are antagonistic enzymes that regulate gene expression through acetylation and deacetylation of histone proteins around which DNA is wrapped inside a eukaryotic cell nucleus. The epigenetic control of HDACs and the cellular imbalance between HATs and HDACs dictate disease states and have been implicated in muscular dystrophy, loss of memory, neurodegeneration and autistic disorders. Altering gene expression profiles through inhibition of HDACs is now emerging as a powerful technique in therapy. This review presents evolving applications of HDAC inhibitors as potential drugs in neurological research and therapy. Mechanisms that govern their expression profiles in neuronal signalling, plasticity and learning will be covered. Promising and exciting possibilities of HDAC inhibitors in memory formation, fear conditioning, ischemic stroke and neural regeneration have been detailed.

  6. An Assay for Measuring Histone Variant Exchange within Nucleosomes In Vitro.

    Science.gov (United States)

    Laflamme, Liette; Guillemette, Benoit; Gaudreau, Luc

    2017-01-01

    The incorporation of histone variants into specific chromatin regions is a mechanism by which cells can regulate many important biological processes. One such example is H2A.Z, a highly conserved variant of H2A that is incorporated in genomic regulatory regions and contributes to control gene expression. H2A.Z variant exchange involves the removal of H2A-H2B dimers from a preassembled nucleosome and their replacement with H2A.Z-H2B dimers. A specific family of chromatin remodeling complexes, homologous to the yeast Swr1 complex, have been shown to be capable of this histone exchange activity both in vivo and in vitro. Here, we describe an assay to measure the histone H2A.Z exchange activity of recombinant human p400 on immobilized mononucleosomes in vitro. The assay can be adapted to other histone exchange complexes/catalytic subunits purified from any species.

  7. Protein phosphatase 1 regulates the histone code for long-term memory.

    Science.gov (United States)

    Koshibu, Kyoko; Gräff, Johannes; Beullens, Monique; Heitz, Fabrice D; Berchtold, Dominik; Russig, Holger; Farinelli, Mélissa; Bollen, Mathieu; Mansuy, Isabelle M

    2009-10-14

    Chromatin remodeling through histone posttranslational modifications (PTMs) and DNA methylation has recently been implicated in cognitive functions, but the mechanisms involved in such epigenetic regulation remain poorly understood. Here, we show that protein phosphatase 1 (PP1) is a critical regulator of chromatin remodeling in the mammalian brain that controls histone PTMs and gene transcription associated with long-term memory. Our data show that PP1 is present at the chromatin in brain cells and interacts with enzymes of the epigenetic machinery including HDAC1 (histone deacetylase 1) and histone demethylase JMJD2A (jumonji domain-containing protein 2A). The selective inhibition of the nuclear pool of PP1 in forebrain neurons in transgenic mice is shown to induce several histone PTMs that include not only phosphorylation but also acetylation and methylation. These PTMs are residue-specific and occur at the promoter of genes important for memory formation like CREB (cAMP response element-binding protein) and NF-kappaB (nuclear factor-kappaB). These histone PTMs further co-occur with selective binding of RNA polymerase II and altered gene transcription, and are associated with improved long-term memory for objects and space. Together, these findings reveal a novel mechanism for the epigenetic control of gene transcription and long-term memory in the adult brain that depends on PP1.

  8. Nuclear lactate dehydrogenase modulates histone modification in human hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Castonguay, Zachary; Auger, Christopher; Thomas, Sean C.; Chahma, M’hamed; Appanna, Vasu D., E-mail: vappanna@laurentian.ca

    2014-11-07

    Highlights: • Nuclear LDH is up-regulated under oxidative stress. • SIRT1 is co-immunoprecipitated bound to nuclear LDH. • Nuclear LDH is involved in histone deacetylation and epigenetics. - Abstract: It is becoming increasingly apparent that the nucleus harbors metabolic enzymes that affect genetic transforming events. Here, we describe a nuclear isoform of lactate dehydrogenase (nLDH) and its ability to orchestrate histone deacetylation by controlling the availability of nicotinamide adenine dinucleotide (NAD{sup +}), a key ingredient of the sirtuin-1 (SIRT1) deacetylase system. There was an increase in the expression of nLDH concomitant with the presence of hydrogen peroxide (H{sub 2}O{sub 2}) in the culture medium. Under oxidative stress, the NAD{sup +} generated by nLDH resulted in the enhanced deacetylation of histones compared to the control hepatocytes despite no discernable change in the levels of SIRT1. There appeared to be an intimate association between nLDH and SIRT1 as these two enzymes co-immunoprecipitated. The ability of nLDH to regulate epigenetic modifications by manipulating NAD{sup +} reveals an intricate link between metabolism and the processing of genetic information.

  9. Acetate supplementation modulates brain histone acetylation and decreases interleukin-1β expression in a rat model of neuroinflammation

    Directory of Open Access Journals (Sweden)

    Soliman Mahmoud L

    2012-03-01

    and mRNA levels were increased by 1.3- and 10-fold, respectively, and acetate supplementation reduced this expression to control levels. Conclusion Based on these results, we conclude that dietary acetate supplementation attenuates neuroglial activation by effectively reducing pro-inflammatory cytokine expression by a mechanism that may involve a distinct site-specific pattern of histone acetylation and histone deacetylase expression in the brain.

  10. In vitro targeting reveals intrinsic histone tail specificity of the Sin3/histone deacetylase and N-CoR/SMRT corepressor complexes.

    NARCIS (Netherlands)

    Vermeulen, M.; Carrozza, MJ; Lasonder, E.; Workman, JL; Logie, C.; Stunnenberg, H.G.

    2004-01-01

    The histone code is among others established via differential acetylation catalyzed by histone acetyltransferases (HATs) and histone deacetylases (HDACs). To unambiguously determine the histone tail specificity of HDAC-containing complexes, we have established an in vitro system consisting of

  11. Function of histone deacetylase inhibitors in inflammation

    NARCIS (Netherlands)

    Grabiec, Aleksander M.; Tak, Paul P.; Reedquist, Kris A.

    2011-01-01

    Histone deacetylases (HDACs) display multi-faceted roles in coordinating the interaction of intracellular signaling pathways with chromatin remodeling and transcription factor function to finely specify gene alterations and maintenance of gene expression during cellular activation, proliferation,

  12. Molecular dynamics of histone H1

    National Research Council Canada - National Science Library

    Raghuram, Nikhil; Carrero, Gustavo; Thng, John; Hendzel, Michael J

    2009-01-01

    .... In this review, we focus on the wealth of information gathered on the molecular kinetics of histone H1 molecules using novel imaging techniques, such as fluorescence recovery after photobleaching...

  13. The emerging functions of histone demethylases

    DEFF Research Database (Denmark)

    Agger, Karl; Christensen, Jesper; Cloos, Paul Ac

    2008-01-01

    Epigenetic information refers to heritable changes in gene function that are stable between cell divisions but which is not a result of changes in the DNA sequence. Part of the epigenetic mechanism has been ascribed to modifications of histones or DNA that affects the transcription of specific...... genes. In this context, post-translational modifications of histone tails, in particular methylation of lysines, are regarded as important for the storage of epigenetic information. Regulation of this information plays an important role during cellular differentiation where cells with different....... The recent identification of proteins with histone demethylase activity has shown that the methylated mark is much more dynamic than previously anticipated, thereby potentially challenging the concept of histone-methylation in stable epigenetic programming....

  14. Cracking the survival code: autophagy-related histone modifications.

    Science.gov (United States)

    Füllgrabe, Jens; Heldring, Nina; Hermanson, Ola; Joseph, Bertrand

    2014-04-01

    Modifications of histones, the chief protein components of the chromatin, have emerged as critical regulators of life and death. While the "apoptotic histone code" came to light a few years ago, accumulating evidence indicates that autophagy, a cell survival pathway, is also heavily regulated by histone-modifying proteins. In this review we describe the emerging "autophagic histone code" and the role of histone modifications in the cellular life vs. death decision.

  15. Nucleosome Dancing at the Tempo of Histone Tail Acetylation

    Directory of Open Access Journals (Sweden)

    Angélique Galvani

    2015-07-01

    Full Text Available The impact of histone acetylation on transcription was revealed over 50 years ago by Allfrey and colleagues. However, it took decades for an understanding of the fine mechanism by which this posttranslational modification affects chromatin structure and promotes transcription. Here, we review breakthroughs linking histone tail acetylation, histone dynamics, and transcription. We also discuss the histone exchange during transcription and highlight the important function of a pool of non-chromatinized histones in chromatin dynamics.

  16. Nucleosome Dancing at the Tempo of Histone Tail Acetylation.

    Science.gov (United States)

    Galvani, Angélique; Thiriet, Christophe

    2015-07-15

    The impact of histone acetylation on transcription was revealed over 50 years ago by Allfrey and colleagues. However, it took decades for an understanding of the fine mechanism by which this posttranslational modification affects chromatin structure and promotes transcription. Here, we review breakthroughs linking histone tail acetylation, histone dynamics, and transcription. We also discuss the histone exchange during transcription and highlight the important function of a pool of non-chromatinized histones in chromatin dynamics.

  17. Deciphering the histone code using mass spectrometry

    Science.gov (United States)

    Ueberheide, Beatrix M.; Mollah, Sahana

    2007-01-01

    During the past decade, studies surrounding chromatin research have grown exponentially. A major focus of chromatin biology is centered on understanding of how histone modifications alter chromatin structure at the molecular and mechanistic levels. Discoveries are being made at a rapid pace due to the advent of new and innovative techniques. Mass spectrometry has emerged as a powerful tool in the field of histone research due to its speed, sensitivity, and ease of use. This has resulted in the identification of a number of novel histone modification sites. In consequence, new roles in biological processes have been discovered and hypothetical models, such as the `histone code' have been reaffirmed or refined. One significant advantage to using mass spectrometric techniques is that the combinations of modifications on different sites can be determined which is crucial to deciphering the `histone code'. In this manuscript, the mass spectrometric approaches developed over the past decade for both qualitative and quantitative analysis of histone post-translational modifications (PTMs) are discussed.

  18. Genome-wide integration on transcription factors, histone acetylation and gene expression reveals genes co-regulated by histone modification patterns.

    Directory of Open Access Journals (Sweden)

    Yayoi Natsume-Kitatani

    Full Text Available N-terminal tails of H2A, H2B, H3 and H4 histone families are subjected to posttranslational modifications that take part in transcriptional regulation mechanisms, such as transcription factor binding and gene expression. Regulation mechanisms under control of histone modification are important but remain largely unclear, despite of emerging datasets for comprehensive analysis of histone modification. In this paper, we focus on what we call genetic harmonious units (GHUs, which are co-occurring patterns among transcription factor binding, gene expression and histone modification. We present the first genome-wide approach that captures GHUs by combining ChIP-chip with microarray datasets from Saccharomyces cerevisiae. Our approach employs noise-robust soft clustering to select patterns which share the same preferences in transcription factor-binding, histone modification and gene expression, which are all currently implied to be closely correlated. The detected patterns are a well-studied acetylation of lysine 16 of H4 in glucose depletion as well as co-acetylation of five lysine residues of H3 with H4 Lys12 and H2A Lys7 responsible for ribosome biogenesis. Furthermore, our method further suggested the recognition of acetylated H4 Lys16 being crucial to histone acetyltransferase ESA1, whose essential role is still under controversy, from a microarray dataset on ESA1 and its bypass suppressor mutants. These results demonstrate that our approach allows us to provide clearer principles behind gene regulation mechanisms under histone modifications and detect GHUs further by applying to other microarray and ChIP-chip datasets. The source code of our method, which was implemented in MATLAB (http://www.mathworks.com/, is available from the supporting page for this paper: http://www.bic.kyoto-u.ac.jp/pathway/natsume/hm_detector.htm.

  19. Histone H3K4 and H3K36 Methylation Independently Recruit the NuA3 Histone Acetyltransferase in Saccharomyces cerevisiae.

    Science.gov (United States)

    Martin, Benjamin J E; McBurney, Kristina L; Maltby, Vicki E; Jensen, Kristoffer N; Brind'Amour, Julie; Howe, LeAnn J

    2017-03-01

    Histone post-translational modifications (PTMs) alter chromatin structure by promoting the interaction of chromatin-modifying complexes with nucleosomes. The majority of chromatin-modifying complexes contain multiple domains that preferentially interact with modified histones, leading to speculation that these domains function in concert to target nucleosomes with distinct combinations of histone PTMs. In Saccharomyces cerevisiae, the NuA3 histone acetyltransferase complex contains three domains, the PHD finger in Yng1, the PWWP domain in Pdp3, and the YEATS domain in Taf14; which in vitro bind to H3K4 methylation, H3K36 methylation, and acetylated and crotonylated H3K9, respectively. While the in vitro binding has been well characterized, the relative in vivo contributions of these histone PTMs in targeting NuA3 is unknown. Here, through genome-wide colocalization and by mutational interrogation, we demonstrate that the PHD finger of Yng1, and the PWWP domain of Pdp3 independently target NuA3 to H3K4 and H3K36 methylated chromatin, respectively. In contrast, we find no evidence to support the YEATS domain of Taf14 functioning in NuA3 recruitment. Collectively our results suggest that the presence of multiple histone PTM binding domains within NuA3, rather than restricting it to nucleosomes containing distinct combinations of histone PTMs, can serve to increase the range of nucleosomes bound by the complex. Interestingly, however, the simple presence of NuA3 is insufficient to ensure acetylation of the associated nucleosomes, suggesting a secondary level of acetylation regulation that does not involve control of HAT-nucleosome interactions. Copyright © 2017 by the Genetics Society of America.

  20. Flavopiridol suppresses tumor necrosis factor-induced activation of activator protein-1, c-Jun N-terminal kinase, p38 mitogen-activated protein kinase (MAPK), p44/p42 MAPK, and Akt, inhibits expression of antiapoptotic gene products, and enhances apoptosis through cytochrome c release and caspase activation in human myeloid cells.

    Science.gov (United States)

    Takada, Yasunari; Sethi, Gautam; Sung, Bokyung; Aggarwal, Bharat B

    2008-05-01

    Although flavopiridol, a semisynthetic flavone, was initially thought to be a specific inhibitor of cyclin-dependent kinases, it has now been shown that flavopiridol mediates antitumor responses through mechanism(s) yet to be defined. We have shown previously that flavopiridol abrogates tumor necrosis factor (TNF)-induced nuclear factor-kappaB (NF-kappaB) activation. In this report, we examined whether this flavone affects other cellular responses activated by TNF. TNF is a potent inducer of activator protein-1 (AP-1), and flavopiridol abrogated this activation in a dose- and time-dependent manner. Flavopiridol also suppressed AP-1 activation induced by various carcinogens and inflammatory stimuli. When examined for its effect on other signaling pathways, flavopiridol inhibited TNF-induced activation of various mitogen-activated protein kinases, including c-Jun NH(2)-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), and p44/p42 MAPK. It is noteworthy that this flavone also suppressed TNF-induced activation of Akt, a cell survival kinase, and expression of various antiapoptotic proteins, such as IAP-1, IAP-2, XIAP, Bcl-2, Bcl-xL, and TRAF-1. Flavopiridol also inhibited the TNF-induced induction of intercellular adhesion molecule-1, c-Myc, and c-Fos, all known to mediate tumorigenesis. Moreover, TNF-induced apoptosis was enhanced by flavopiridol through activation of the bid-cytochrome-caspase-9-caspase-3 pathway. Overall, our results clearly suggest that flavopiridol interferes with the TNF cell-signaling pathway, leading to suppression of antiapoptotic mechanisms and enhancement of apoptosis.

  1. Sustained activation of p38 mitogen-activated protein kinase and c-Jun N-terminal kinase pathways by hepatitis B virus X protein mediates apoptosis via induction of Fas/FasL and tumor necrosis factor (TNF) receptor 1/TNF-alpha expression.

    Science.gov (United States)

    Wang, Wen-Horng; Grégori, Gérald; Hullinger, Ronald L; Andrisani, Ourania M

    2004-12-01

    Activation of the cellular stress pathways (c-Jun N-terminal kinase [JNK] and p38 mitogen-activated protein [MAP] kinase) is linked to apoptosis. However, whether both pathways are required for apoptosis remains unresolved. Hepatitis B virus X protein (pX) activates p38 MAP kinase and JNK pathways and, in response to weak apoptotic signals, sensitizes hepatocytes to apoptosis. Employing hepatocyte cell lines expressing pX, which was regulated by tetracycline, we investigated the mechanism of apoptosis by p38 MAP kinase and JNK pathway activation. Inhibition of the p38 MAP kinase pathway rescues by 80% the initiation of pX-mediated apoptosis, whereas subsequent apoptotic events involve both pathways. pX-mediated activation of p38 MAP kinase and JNK pathways is sustained, inducing the transcription of the death receptor family genes encoding Fas/FasL and tumor necrosis factor receptor 1 (TNFR1)/TNF-alpha and the p53-regulated Bax and Noxa genes. The pX-dependent expression of Fas/FasL and TNFR1/TNF-alpha mediates caspase 8 activation, resulting in Bid cleavage. In turn, activated Bid, acting with pX-induced Bax and Noxa, mediates the mitochondrial release of cytochrome c, resulting in the activation of caspase 9 and apoptosis. Combined antibody neutralization of FasL and TNF-alpha reduces by 70% the initiation of pX-mediated apoptosis. These results support the importance of the pX-dependent activation of both the p38 MAP kinase and JNK pathways in pX-mediated apoptosis and suggest that this mechanism of apoptosis occurs in vivo in response to weak apoptotic signals.

  2. A histone-mimicking interdomain linker in a multidomain protein modulates multivalent histone binding.

    Science.gov (United States)

    Kostrhon, Sebastian; Kontaxis, Georg; Kaufmann, Tanja; Schirghuber, Erika; Kubicek, Stefan; Konrat, Robert; Slade, Dea

    2017-10-27

    N-terminal histone tails are subject to many posttranslational modifications that are recognized by and interact with designated reader domains in histone-binding proteins. BROMO domain adjacent to zinc finger 2B (BAZ2B) is a multidomain histone-binding protein that contains two histone reader modules, a plant homeodomain (PHD) and a bromodomain (BRD), linked by a largely disordered linker. Although previous studies have reported specificity of the PHD domain for the unmodified N terminus of histone H3 and of the BRD domain for H3 acetylated at Lys14 (H3K14ac), the exact mode of H3 binding by BAZ2B and its regulation are underexplored. Here, using isothermal titration calorimetry and NMR spectroscopy, we report that acidic residues in the BAZ2B PHD domain are essential for H3 binding and that BAZ2B PHD-BRD establishes a polyvalent interaction with H3K14ac. Furthermore, we provide evidence that the disordered interdomain linker modulates the histone-binding affinity by interacting with the PHD domain. In particular, lysine-rich stretches in the linker, which resemble the positively charged N terminus of histone H3, reduce the binding affinity of the PHD finger toward the histone substrate. Phosphorylation, acetylation, or poly(ADP-ribosyl)ation of the linker residues may therefore act as a cellular mechanism to transiently tune BAZ2B histone-binding affinity. Our findings further support the concept of interdomain linkers serving a dual role in substrate binding by appropriately positioning the adjacent domains and by electrostatically modulating substrate binding. Moreover, inhibition of histone binding by a histone-mimicking interdomain linker represents another example of regulation of protein-protein interactions by intramolecular mimicry. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. Prohexadione, a plant growth regulator, inhibits histone lysine demethylases and modulates epigenetics.

    Science.gov (United States)

    Vavilala, Divya Teja; Reddy, Sujatha; Sachchidanand; Prakash, Swami; Ponnaluri, V K Chaithanya; Kumar, Arvind; Mukherji, Mridul

    2014-01-01

    Epigenetic modifications, particularly DNA methylation and posttranslational histone modifications regulate heritable changes in transcription without changes in the DNA sequence. Despite a number of studies showing clear links between environmental factors and DNA methylation, little is known about the effect of environmental factors on the recently identified histone lysine methylation. Since their identification numerous studies have establish critical role played by these enzymes in mammalian development. Identification of the Jumonji (Jmj) domain containing histone lysine demethylase have added a new dimension to epigenetic control of gene expression by dynamic regulation of histone methylation marks. The objective of our study was to evaluate the effect of prohexadione and trinexapac, widely used plant growth regulators of the acylcyclohexanediones class, on the enzymatic activity of histone lysine demethylases and histone modifications during the neural stem/progenitor cell differentiation. Here we show that prohexadione, but not trinexapac, directly inhibits non-heme iron (II), 2-oxoglutarate-dependent histone lysine demethylase such as Jmjd2a. We used molecular modeling to show binding of prohexadione to Jmjd2a. We also performed in vitro demethylation assays to show the inhibitory effect of prohexadione on Jmjd2a. Further we tested this molecule in cell culture model of mouse hippocampal neural stem/progenitor cells to demonstrate its effect toward neuronal proliferation and differentiation. Molecular modeling studies suggest that prohexadione binds to the 2-oxoglutarate binding site of Jmjd2a demethylase. Treatment of primary neural stem/progenitor cells with prohexadione showed a concentration dependent reduction in their proliferation. Further, the prohexadione treated neurospheres were induced toward neurogenic lineage upon differentiation. Our results describe an important chemico-biological interaction of prohexadione, in light of critical roles

  4. Accuracy of circulating histones in predicting persistent organ failure and mortality in patients with acute pancreatitis.

    Science.gov (United States)

    Liu, T; Huang, W; Szatmary, P; Abrams, S T; Alhamdi, Y; Lin, Z; Greenhalf, W; Wang, G; Sutton, R; Toh, C H

    2017-08-01

    Early prediction of acute pancreatitis severity remains a challenge. Circulating levels of histones are raised early in mouse models and correlate with disease severity. It was hypothesized that circulating histones predict persistent organ failure in patients with acute pancreatitis. Consecutive patients with acute pancreatitis fulfilling inclusion criteria admitted to Royal Liverpool University Hospital were enrolled prospectively between June 2010 and March 2014. Blood samples were obtained within 48 h of abdominal pain onset and relevant clinical data during the hospital stay were collected. Healthy volunteers were enrolled as controls. The primary endpoint was occurrence of persistent organ failure. The predictive values of circulating histones, clinical scores and other biomarkers were determined. Among 236 patients with acute pancreatitis, there were 156 (66·1 per cent), 57 (24·2 per cent) and 23 (9·7 per cent) with mild, moderate and severe disease respectively, according to the revised Atlanta classification. Forty-seven healthy volunteers were included. The area under the receiver operating characteristic (ROC) curve (AUC) for circulating histones in predicting persistent organ failure and mortality was 0·92 (95 per cent c.i. 0·85 to 0·99) and 0·96 (0·92 to 1·00) respectively; histones were at least as accurate as clinical scores or biochemical markers. For infected pancreatic necrosis and/or sepsis, the AUC was 0·78 (0·62 to 0·94). Histones did not predict or correlate with local pancreatic complications, but correlated negatively with leucocyte cell viability (r = -0·511, P = 0·001). Quantitative assessment of circulating histones in plasma within 48 h of abdominal pain onset can predict persistent organ failure and mortality in patients with acute pancreatitis. Early death of immune cells may contribute to raised circulating histone levels in acute pancreatitis. © 2017 The Authors. BJS published by John Wiley & Sons Ltd on behalf of BJS

  5. Antibody-free reading of the histone code using a simple chemical sensor array.

    Science.gov (United States)

    Minaker, Samuel A; Daze, Kevin D; Ma, Manuel C F; Hof, Fraser

    2012-07-18

    The histone code refers to the complex network of histone post-translational modifications that control gene expression and are of high interest as drivers of a large number of human diseases. We report here on a mix-and-match toolkit of readily available dyes and calixarene host molecules that can be combined to form dye-displacement sensors that respond to a wide variety of cationic peptides. Using the data from only two or three such simple supramolecular sensors as a chemical sensor array produces fingerprints of data that discriminate robustly among many kinds of histone code elements. "Reads" that are accomplished include the discrimination of unmethylated, mono-, di-, and trimethylated lysines on a single histone tail sequence, identification of different modifications and combinations of modifications on a single histone tail sequence, identification of a single modification type in several different sequence contexts, and identification of isomeric dimethylarginine modifications. Reads that are sometimes troublesome for antibodies are achieved. We also report on the ability of the sensor array to report simultaneously on the concentrations and identities of histone modifications. This sensor array discriminates between post-translationally modified analytes without being limited to partners that contain a single, programmed binding interaction.

  6. Beta-N-acetylglucosamine (O-GlcNAc) is part of the histone code.

    Science.gov (United States)

    Sakabe, Kaoru; Wang, Zihao; Hart, Gerald W

    2010-11-16

    Dynamic posttranslational modification of serine and threonine residues of nucleocytoplasmic proteins by β-N-acetylglucosamine (O-GlcNAc) is a regulator of cellular processes such as transcription, signaling, and protein-protein interactions. Like phosphorylation, O-GlcNAc cycles in response to a wide variety of stimuli. Although cycling of O-GlcNAc is catalyzed by only two highly conserved enzymes, O-GlcNAc transferase (OGT), which adds the sugar, and β-N-acetylglucosaminidase (O-GlcNAcase), which hydrolyzes it, the targeting of these enzymes is highly specific and is controlled by myriad interacting subunits. Here, we demonstrate by multiple specific immunological and enzymatic approaches that histones, the proteins that package DNA within the nucleus, are O-GlcNAcylated in vivo. Histones also are substrates for OGT in vitro. We identify O-GlcNAc sites on histones H2A, H2B, and H4 using mass spectrometry. Finally, we show that histone O-GlcNAcylation changes during mitosis and with heat shock. Taken together, these data show that O-GlcNAc cycles dynamically on histones and can be considered part of the histone code.

  7. Finding associations among histone modifications using sparse partial correlation networks.

    Directory of Open Access Journals (Sweden)

    Julia Lasserre

    Full Text Available Histone modifications are known to play an important role in the regulation of transcription. While individual modifications have received much attention in genome-wide analyses, little is known about their relationships. Some authors have built Bayesian networks of modifications, however most often they have used discretized data, and relied on unrealistic assumptions such as the absence of feedback mechanisms or hidden confounding factors. Here, we propose to infer undirected networks based on partial correlations between histone modifications. Within the partial correlation framework, correlations among two variables are controlled for associations induced by the other variables. Partial correlation networks thus focus on direct associations of histone modifications. We apply this methodology to data in CD4+ cells. The resulting network is well supported by common knowledge. When pairs of modifications show a large difference between their correlation and their partial correlation, a potential confounding factor is identified and provided as explanation. Data from different cell types (IMR90, H1 is also exploited in the analysis to assess the stability of the networks. The results are remarkably similar across cell types. Based on this observation, the networks from the three cell types are integrated into a consensus network to increase robustness. The data and the results discussed in the manuscript can be found, together with code, on http://spcn.molgen.mpg.de/index.html.

  8. Pattern of change in histone 3 lysine 9 acetylation and histone ...

    Indian Academy of Sciences (India)

    Pattern of change in histone 3 lysine 9 acetylation and histone deacetylases in development of zebrafish embryo. Yanning Li Junxia Wang Ying Xie Shufeng Liu Ye ... Wang1 Ying Xie1 Shufeng Liu1 Ye Tian1. Hebei Key Lab of Laboratory Animal, Hebei Medical University, Shijiazhuang 050017, People's Republic of China ...

  9. Replication stress interferes with histone recycling and predeposition marking of new histones

    DEFF Research Database (Denmark)

    Jasencakova, Zuzana; Scharf, Annette N D; Ask, Katrine

    2010-01-01

    To restore chromatin on new DNA during replication, recycling of histones evicted ahead of the fork is combined with new histone deposition. The Asf1 histone chaperone, which buffers excess histones under stress, is a key player in this process. Yet how histones handled by human Asf1 are modified...... remains unclear. Here we identify marks on histones H3-H4 bound to Asf1 and changes induced upon replication stress. In S phase, distinct cytosolic and nuclear Asf1b complexes show ubiquitous H4K5K12diAc and heterogeneous H3 marks, including K9me1, K14ac, K18ac, and K56ac. Upon acute replication arrest......, the predeposition mark H3K9me1 and modifications typical of chromatin accumulate in Asf1 complexes. In parallel, ssDNA is generated at replication sites, consistent with evicted histones being trapped with Asf1. During recovery, histones stored with Asf1 are rapidly used as replication resumes. This shows...

  10. Importance of electrostatic interactions in the association of intrinsically disordered histone chaperone Chz1 and histone H2A.Z-H2B.

    Directory of Open Access Journals (Sweden)

    Xiakun Chu

    Full Text Available Histone chaperones facilitate assembly and disassembly of nucleosomes. Understanding the process of how histone chaperones associate and dissociate from the histones can help clarify their roles in chromosome metabolism. Some histone chaperones are intrinsically disordered proteins (IDPs. Recent studies of IDPs revealed that the recognition of the biomolecules is realized by the flexibility and dynamics, challenging the century-old structure-function paradigm. Here we investigate the binding between intrinsically disordered chaperone Chz1 and histone variant H2A.Z-H2B by developing a structure-based coarse-grained model, in which Debye-Hückel model is implemented for describing electrostatic interactions due to highly charged characteristic of Chz1 and H2A.Z-H2B. We find that major structural changes of Chz1 only occur after the rate-limiting electrostatic dominant transition state and Chz1 undergoes folding coupled binding through two parallel pathways. Interestingly, although the electrostatic interactions stabilize bound complex and facilitate the recognition at first stage, the rate for formation of the complex is not always accelerated due to slow escape of conformations with non-native electrostatic interactions at low salt concentrations. Our studies provide an ionic-strength-controlled binding/folding mechanism, leading to a cooperative mechanism of "local collapse or trapping" and "fly-casting" together and a new understanding of the roles of electrostatic interactions in IDPs' binding.

  11. A Common histone modification code on C4 genes in maize and its conservation in Sorghum and Setaria italica.

    Science.gov (United States)

    Heimann, Louisa; Horst, Ina; Perduns, Renke; Dreesen, Björn; Offermann, Sascha; Peterhansel, Christoph

    2013-05-01

    C4 photosynthesis evolved more than 60 times independently in different plant lineages. Each time, multiple genes were recruited into C4 metabolism. The corresponding promoters acquired new regulatory features such as high expression, light induction, or cell type-specific expression in mesophyll or bundle sheath cells. We have previously shown that histone modifications contribute to the regulation of the model C4 phosphoenolpyruvate carboxylase (C4-Pepc) promoter in maize (Zea mays). We here tested the light- and cell type-specific responses of three selected histone acetylations and two histone methylations on five additional C4 genes (C4-Ca, C4-Ppdk, C4-Me, C4-Pepck, and C4-RbcS2) in maize. Histone acetylation and nucleosome occupancy assays indicated extended promoter regions with regulatory upstream regions more than 1,000 bp from the transcription initiation site for most of these genes. Despite any detectable homology of the promoters on the primary sequence level, histone modification patterns were highly coregulated. Specifically, H3K9ac was regulated by illumination, whereas H3K4me3 was regulated in a cell type-specific manner. We further compared histone modifications on the C4-Pepc and C4-Me genes from maize and the homologous genes from sorghum (Sorghum bicolor) and Setaria italica. Whereas sorghum and maize share a common C4 origin, C4 metabolism evolved independently in S. italica. The distribution of histone modifications over the promoters differed between the species, but differential regulation of light-induced histone acetylation and cell type-specific histone methylation were evident in all three species. We propose that a preexisting histone code was recruited into C4 promoter control during the evolution of C4 metabolism.

  12. Histone deacetylase inhibitors in cancer therapy.

    Science.gov (United States)

    Lane, Andrew A; Chabner, Bruce A

    2009-11-10

    Epigenetic processes are implicated in cancer causation and progression. The acetylation status of histones regulates access of transcription factors to DNA and influences levels of gene expression. Histone deacetylase (HDAC) activity diminishes acetylation of histones, causing compaction of the DNA/histone complex. This compaction blocks gene transcription and inhibits differentiation, providing a rationale for developing HDAC inhibitors. In this review, we explore the biology of the HDAC enzymes, summarize the pharmacologic properties of HDAC inhibitors, and examine results of selected clinical trials. We consider the potential of these inhibitors in combination therapy with targeted drugs and with cytotoxic chemotherapy. HDAC inhibitors promote growth arrest, differentiation, and apoptosis of tumor cells, with minimal effects on normal tissue. In addition to decompaction of the histone/DNA complex, HDAC inhibition also affects acetylation status and function of nonhistone proteins. HDAC inhibitors have demonstrated antitumor activity in clinical trials, and one drug of this class, vorinostat, is US Food and Drug Administration approved for the treatment of cutaneous T-cell lymphoma. Other inhibitors in advanced stages of clinical development, including depsipeptide and MGCD0103, differ from vorinostat in structure and isoenzyme specificity, and have shown activity against lymphoma, leukemia, and solid tumors. Promising preclinical activity in combination with cytotoxics, inhibitors of heat shock protein 90, and inhibitors of proteasome function have led to combination therapy trials. HDAC inhibitors are an important emerging therapy with single-agent activity against multiple cancers, and have significant potential in combination use.

  13. Detection of histone modifications in plant leaves.

    Science.gov (United States)

    Jaskiewicz, Michal; Peterhansel, Christoph; Conrath, Uwe

    2011-09-23

    Chromatin structure is important for the regulation of gene expression in eukaryotes. In this process, chromatin remodeling, DNA methylation, and covalent modifications on the amino-terminal tails of histones H3 and H4 play essential roles(1-2). H3 and H4 histone modifications include methylation of lysine and arginine, acetylation of lysine, and phosphorylation of serine residues(1-2). These modifications are associated either with gene activation, repression, or a primed state of gene that supports more rapid and robust activation of expression after perception of appropriate signals (microbe-associated molecular patterns, light, hormones, etc.)(3-7). Here, we present a method for the reliable and sensitive detection of specific chromatin modifications on selected plant genes. The technique is based on the crosslinking of (modified) histones and DNA with formaldehyde(8,9), extraction and sonication of chromatin, chromatin immunoprecipitation (ChIP) with modification-specific antibodies(9,10), de-crosslinking of histone-DNA complexes, and gene-specific real-time quantitative PCR. The approach has proven useful for detecting specific histone modifications associated with C(4;) photosynthesis in maize(5,11) and systemic immunity in Arabidopsis(3).

  14. Histone methylases as novel drug targets: developing inhibitors of EZH2.

    Science.gov (United States)

    Baugé, Catherine; Bazille, Céline; Girard, Nicolas; Lhuissier, Eva; Boumediene, Karim

    2014-01-01

    Post-translational modifications of histones (so-called epigenetic modifications) play a major role in transcriptional control and normal development, and are tightly regulated. Disruption of their control is a frequent event in disease. In particular, the methylation of lysine 27 on histone H3 (H3K27), induced by the methylase EZH2, emerges as a key control of gene expression and a major regulator of cell physiology. The identification of driver mutations in EZH2 has already led to new prognostic and therapeutic advances, and new classes of potent and specific inhibitors for EZH2 show promising results in preclinical trials. This review examines the roles of histone lysine methylases and demethylases in cells and focuses on the recent knowledge and developments about EZH2.

  15. Histones bundle F-actin filaments and affect actin structure.

    Science.gov (United States)

    Blotnick, Edna; Sol, Asaf; Muhlrad, Andras

    2017-01-01

    Histones are small polycationic proteins complexed with DNA located in the cell nucleus. Upon apoptosis they are secreted from the cells and react with extracellular polyanionic compounds. Actin which is a polyanionic protein, is also secreted from necrotic cells and interacts with histones. We showed that both histone mixture (histone type III) and the recombinant H2A histone bundles F-actin, increases the viscosity of the F-actin containing solution and polymerizes G-actin. The histone-actin bundles are relatively insensitive to increase of ionic strength, unlike other polycation, histatin, lysozyme, spermine and LL-37 induced F-actin bundles. The histone-actin bundles dissociate completely only in the presence of 300-400 mM NaCl. DNA, which competes with F-actin for histones, disassembles histone induced actin bundles. DNase1, which depolymerizes F- to G-actin, actively unbundles the H2A histone induced but slightly affects the histone mixture induced actin bundles. Cofilin decreases the amount of F-actin sedimented by low speed centrifugation, increases light scattering and viscosity of F-actin-histone mixture containing solutions and forms star like superstructures by copolymerizing G-actin with H2A histone. The results indicate that histones are tightly attached to F-actin by strong electrostatic and hydrophobic forces. Since both histones and F-actin are present in the sputum of patients with cystic fibrosis, therefore, the formation of the stable histone-actin bundles can contribute to the pathology of this disease by increasing the viscosity of the sputum. The actin-histone interaction in the nucleus might affect gene expression.

  16. Histones bundle F-actin filaments and affect actin structure.

    Directory of Open Access Journals (Sweden)

    Edna Blotnick

    Full Text Available Histones are small polycationic proteins complexed with DNA located in the cell nucleus. Upon apoptosis they are secreted from the cells and react with extracellular polyanionic compounds. Actin which is a polyanionic protein, is also secreted from necrotic cells and interacts with histones. We showed that both histone mixture (histone type III and the recombinant H2A histone bundles F-actin, increases the viscosity of the F-actin containing solution and polymerizes G-actin. The histone-actin bundles are relatively insensitive to increase of ionic strength, unlike other polycation, histatin, lysozyme, spermine and LL-37 induced F-actin bundles. The histone-actin bundles dissociate completely only in the presence of 300-400 mM NaCl. DNA, which competes with F-actin for histones, disassembles histone induced actin bundles. DNase1, which depolymerizes F- to G-actin, actively unbundles the H2A histone induced but slightly affects the histone mixture induced actin bundles. Cofilin decreases the amount of F-actin sedimented by low speed centrifugation, increases light scattering and viscosity of F-actin-histone mixture containing solutions and forms star like superstructures by copolymerizing G-actin with H2A histone. The results indicate that histones are tightly attached to F-actin by strong electrostatic and hydrophobic forces. Since both histones and F-actin are present in the sputum of patients with cystic fibrosis, therefore, the formation of the stable histone-actin bundles can contribute to the pathology of this disease by increasing the viscosity of the sputum. The actin-histone interaction in the nucleus might affect gene expression.

  17. Small molecule inhibitors of histone deacetylases and acetyltransferases as potential therapeutics in oncology

    NARCIS (Netherlands)

    van den Bosch, Thea; Leus, Niek; Timmerman, Tirza; Dekker, Frank J

    2016-01-01

    Uncontrolled cell proliferation and resistance to apoptosis in cancer are, among others, regulated by post-translational modifications of histone proteins. The most investigated type of histone modification is lysine acetylation. Histone acetyltransferases (HATs), acetylate histone lysine residues,

  18. Telomeres, histone code, and DNA damage response.

    Science.gov (United States)

    Misri, S; Pandita, S; Kumar, R; Pandita, T K

    2008-01-01

    Genomic stability is maintained by telomeres, the end terminal structures that protect chromosomes from fusion or degradation. Shortening or loss of telomeric repeats or altered telomere chromatin structure is correlated with telomere dysfunction such as chromosome end-to-end associations that could lead to genomic instability and gene amplification. The structure at the end of telomeres is such that its DNA differs from DNA double strand breaks (DSBs) to avoid nonhomologous end-joining (NHEJ), which is accomplished by forming a unique higher order nucleoprotein structure. Telomeres are attached to the nuclear matrix and have a unique chromatin structure. Whether this special structure is maintained by specific chromatin changes is yet to be thoroughly investigated. Chromatin modifications implicated in transcriptional regulation are thought to be the result of a code on the histone proteins (histone code). This code, involving phosphorylation, acetylation, methylation, ubiquitylation, and sumoylation of histones, is believed to regulate chromatin accessibility either by disrupting chromatin contacts or by recruiting non-histone proteins to chromatin. The histone code in which distinct histone tail-protein interactions promote engagement may be the deciding factor for choosing specific DSB repair pathways. Recent evidence suggests that such mechanisms are involved in DNA damage detection and repair. Altered telomere chromatin structure has been linked to defective DNA damage response (DDR), and eukaryotic cells have evolved DDR mechanisms utilizing proficient DNA repair and cell cycle checkpoints in order to maintain genomic stability. Recent studies suggest that chromatin modifying factors play a critical role in the maintenance of genomic stability. This review will summarize the role of DNA damage repair proteins specifically ataxia-telangiectasia mutated (ATM) and its effectors and the telomere complex in maintaining genome stability. Copyright 2008 S. Karger

  19. Replicating chromatin: a tale of histones

    DEFF Research Database (Denmark)

    Groth, Anja

    2009-01-01

    framework of chromatin and carry information to specify higher-order organization and gene expression. When replication forks traverse the chromosomes, nucleosomes are transiently disrupted, allowing the replication machinery to gain access to DNA. Histone recycling, together with new deposition, ensures...... reassembly on nascent DNA strands. The aim of this review is to discuss how histones - new and old - are handled at the replication fork, highlighting new mechanistic insights and revisiting old paradigms.......Chromatin serves structural and functional roles crucial for genome stability and correct gene expression. This organization must be reproduced on daughter strands during replication to maintain proper overlay of epigenetic fabric onto genetic sequence. Nucleosomes constitute the structural...

  20. The role of global histone post-translational modifications during mammalian hibernation.

    Science.gov (United States)

    Tessier, Shannon N; Luu, Bryan E; Smith, Jeffrey C; Storey, Kenneth B

    2017-04-01

    Mammalian hibernators must cope with hypothermia, ischemia-reperfusion, and finite fuel reserves during days or weeks of continuous torpor. One means of lowering ATP demands during hibernation involves substantial transcriptional controls. The present research analyzed epigenetic regulatory factors as a means of achieving transcriptional control over cycles of torpor-arousal. This study analyzes differential regulation of select histone modifications (e.g. phosphorylation, acetylation, methylation), and identifies post-translational modifications on purified histones using mass spectrometry from thirteen-lined ground squirrels (Ictidomys tridecemlineatus). Post-translational modifications on histone proteins were responsive to torpor-arousal, suggesting a potential mechanism to dynamically alter chromatin structure. Furthermore, proteomic sequencing data of ground squirrel histones identified lysine 19 and 24 acetylation on histone H3, while acetylation sites identified on H2B were lysine 6, 47, 110, and 117. The present study provides a new glimpse into the epigenetic mechanisms which may play a role in transcriptional regulation during mammalian hibernation. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Construction of Comprehensive Dosage-Matching Core Histone Mutant Libraries forSaccharomyces cerevisiae.

    Science.gov (United States)

    Jiang, Shuangying; Liu, Yan; Wang, Ann; Qin, Yiran; Luo, Maoguo; Wu, Qingyu; Boeke, Jef D; Dai, Junbiao

    2017-12-01

    Saccharomyces cerevisiae contains two genes for each core histone, which are presented as pairs under the control of a divergent promoter, i.e. , HHT1-HHF1 , HHT2-HHF2 , HTA1-HTB1 and HTA2-HTB2 HHT1-HHF1 , and HHT2-HHF2 encode histone H3 and H4 with identical amino acid sequences but under the control of differently regulated promoters. Previous mutagenesis studies were carried out by deleting one pair and mutating the other one. Here, we present the design and construction of three additional libraries covering HTA1-HTB1 , HTA2-HTB2 , and HHT1-HHF1 respectively. Together with the previously described library of HHT2-HHF2 mutants, a systematic and complete collection of mutants for each of the eight core S. cerevisiae histone genes becomes available. Each designed mutant was incorporated into the genome, generating three more corresponding libraries of yeast strains. We demonstrated that, although, under normal growth conditions, strains with single-copy integrated histone genes lacked phenotypes, in some growth conditions, growth deficiencies were observed. Specifically, we showed that addition of a second copy of the mutant histone gene could rescue the lethality in some previously known mutants that cannot survive with a single copy. This resource enables systematic studies of function of each nucleosome residue in plasmid, single-copy, and double-copy integrated formats. Copyright © 2017 by the Genetics Society of America.

  2. Variations of Histone Modification Patterns: Contributions of Inter-plant Variability and Technical Factors

    Directory of Open Access Journals (Sweden)

    Sylva Brabencová

    2017-12-01

    Full Text Available Inter-individual variability of conspecific plants is governed by differences in their genetically determined growth and development traits, environmental conditions, and adaptive responses under epigenetic control involving histone post-translational modifications. The apparent variability in histone modifications among plants might be increased by technical variation introduced in sample processing during epigenetic analyses. Thus, to detect true variations in epigenetic histone patterns associated with given factors, the basal variability among samples that is not associated with them must be estimated. To improve knowledge of relative contribution of biological and technical variation, mass spectrometry was used to examine histone modification patterns (acetylation and methylation among Arabidopsis thaliana plants of ecotypes Columbia 0 (Col-0 and Wassilewskija (Ws homogenized by two techniques (grinding in a cryomill or with a mortar and pestle. We found little difference in histone modification profiles between the ecotypes. However, in comparison of the biological and technical components of variability, we found consistently higher inter-individual variability in histone mark levels among Ws plants than among Col-0 plants (grown from seeds collected either from single plants or sets of plants. Thus, more replicates of Ws would be needed for rigorous analysis of epigenetic marks. Regarding technical variability, the cryomill introduced detectably more heterogeneity in the data than the mortar and pestle treatment, but mass spectrometric analyses had minor apparent effects. Our study shows that it is essential to consider inter-sample variance and estimate suitable numbers of biological replicates for statistical analysis for each studied organism when investigating changes in epigenetic histone profiles.

  3. Plant Responses to Abiotic Stress Regulated by Histone Deacetylases

    Directory of Open Access Journals (Sweden)

    Ming Luo

    2017-12-01

    Full Text Available In eukaryotic cells, histone acetylation and deacetylation play an important role in the regulation of gene expression. Histone acetylation levels are modulated by histone acetyltransferases and histone deacetylases (HDACs. Recent studies indicate that HDACs play essential roles in the regulation of gene expression in plant response to environmental stress. In this review, we discussed the recent advance regarding the plant HDACs and their functions in the regulation of abiotic stress responses. The role of HDACs in autophagy was also discussed.

  4. Nucleosome Dancing at the Tempo of Histone Tail Acetylation

    OpenAIRE

    Angélique Galvani; Christophe Thiriet

    2015-01-01

    The impact of histone acetylation on transcription was revealed over 50 years ago by Allfrey and colleagues. However, it took decades for an understanding of the fine mechanism by which this posttranslational modification affects chromatin structure and promotes transcription. Here, we review breakthroughs linking histone tail acetylation, histone dynamics, and transcription. We also discuss the histone exchange during transcription and highlight the important function of a pool of non-chroma...

  5. Recent advances of histone modification in gastric cancer

    Directory of Open Access Journals (Sweden)

    Wen-Yan Yang

    2014-01-01

    Full Text Available Epigenetics play important roles during development progress of tumor. The histone modifications are the most important constituted field. Recently, accumulating research focused on exploring the roles of those modifications in regulating tumorigenesis. Moreover, the dysregulation of histone modifications is supposed to have vital clinical significance. Numerous histone modifications have the potential to be prognostic biomarkers, monitoring response of therapy, early diagnostic markers. Herein, we review the recent advances of histone modifications involving development of gastric cancer.

  6. Histone methylations in heart development, congenital and adult heart diseases

    OpenAIRE

    Zhang, Qing-Jun; Liu, Zhi-Ping

    2015-01-01

    Heart development comprises myocyte specification, differentiation and cardiac morphogenesis. These processes are regulated by a group of core cardiac transcription factors in a coordinated temporal and spatial manner. Histone methylation is an emerging epigenetic mechanism for regulating gene transcription. Interplay among cardiac transcription factors and histone lysine modifiers plays important role in heart development. Aberrant expression and mutation of the histone lysine modifiers duri...

  7. Trichostatin A induced histone acetylation causes decondensation of interphase chromatin.

    NARCIS (Netherlands)

    T.A. Knoch (Tobias); M. Wachsmuth (Malte); M. Frank-Stöhr (Monika); M. Stöhr (Michael); C.P. Bacher (Christian); K. Rippe (Karsten)

    2004-01-01

    textabstractThe effect of trichostatin A (TSA)-induced histone acetylation on the interphase chromatin structure was visualized in vivo with a HeLa cell line stably expressing histone H2A, which was fused to enhanced yellow fluorescent protein. The globally increased histone acetylation caused a

  8. Global histone modification fingerprinting in human cells using epigenetic reverse phase protein array.

    Science.gov (United States)

    Partolina, Marina; Thoms, Hazel C; MacLeod, Kenneth G; Rodriguez-Blanco, Giovanny; Clarke, Matthew N; Venkatasubramani, Anuroop V; Beesoo, Rima; Larionov, Vladimir; Neergheen-Bhujun, Vidushi S; Serrels, Bryan; Kimura, Hiroshi; Carragher, Neil O; Kagansky, Alexander

    2017-01-01

    The balance between acetylation and deacetylation of histone proteins plays a critical role in the regulation of genomic functions. Aberrations in global levels of histone modifications are linked to carcinogenesis and are currently the focus of intense scrutiny and translational research investments to develop new therapies, which can modify complex disease pathophysiology through epigenetic control. However, despite significant progress in our understanding of the molecular mechanisms of epigenetic machinery in various genomic contexts and cell types, the links between epigenetic modifications and cellular phenotypes are far from being clear. For example, enzymes controlling histone modifications utilize key cellular metabolites associated with intra- and extracellular feedback loops, adding a further layer of complexity to this process. Meanwhile, it has become increasingly evident that new assay technologies which provide robust and precise measurement of global histone modifications are required, for at least two pressing reasons: firstly, many approved drugs are known to influence histone modifications and new cancer therapies are increasingly being developed towards targeting histone deacetylases (HDACs) and other epigenetic readers and writers. Therefore, robust assays for fingerprinting the global effects of such drugs on preclinical cell, organoid and in vivo models is required; and secondly, robust histone-fingerprinting assays applicable to patient samples may afford the development of next-generation diagnostic and prognostic tools. In our study, we have used a panel of monoclonal antibodies to determine the relative changes in the global abundance of post-translational modifications on histones purified from cancer cell lines treated with HDAC inhibitors using a novel technique, called epigenetic reverse phase protein array. We observed a robust increase in acetylation levels within 2-24 h after inhibition of HDACs in different cancer cell lines

  9. ADP-ribosylation of histones by ARTD1: an additional module of the histone code?

    Science.gov (United States)

    Hottiger, Michael O

    2011-06-06

    ADP-ribosylation is a covalent post-translational protein modification catalyzed by ADP-ribosyltransferases and is involved in important processes such as cell cycle regulation, DNA damage response, replication or transcription. Histones are ADP-ribosylated by ADP-ribosyltransferase diphtheria toxin-like 1 at specific amino acid residues, in particular lysines, of the histones tails. Specific ADP-ribosyl hydrolases and poly-ADP-ribose glucohydrolases degrade the ADP-ribose polymers. The ADP-ribose modification is read by zinc finger motifs or macrodomains, which then regulate chromatin structure and transcription. Thus, histone ADP-ribosylation may be considered an additional component of the histone code. Copyright © 2011 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  10. Expanding the Reader Landscape of Histone Acylation.

    Science.gov (United States)

    Khan, Abid; Bridgers, Joseph B; Strahl, Brian D

    2017-04-04

    In this issue of Structure,Klein et al. (2017) expand our understanding of what reader domains bind to by showing that MORF, a double PHD domain containing lysine acetyltransferase, is a preferential reader of histone lysine acylation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Histone deacetylases in memory and cognition.

    Science.gov (United States)

    Penney, Jay; Tsai, Li-Huei

    2014-12-09

    Over the past 30 years, lysine acetylation of histone and nonhistone proteins has become established as a key modulator of gene expression regulating numerous aspects of cell biology. Neuronal growth and plasticity are no exception; roles for lysine acetylation and deacetylation in brain function and dysfunction continue to be uncovered. Transcriptional programs coupling synaptic activity to changes in gene expression are critical to the plasticity mechanisms underlying higher brain functions. These transcriptional programs can be modulated by changes in histone acetylation, and in many cases, transcription factors and histone-modifying enzymes are recruited together to plasticity-associated genes. Lysine acetylation, catalyzed by lysine acetyltransferases (KATs), generally promotes cognitive performance, whereas the opposing process, catalyzed by histone lysine deacetylases (HDACs), appears to negatively regulate cognition in multiple brain regions. Consistently, mutation or deregulation of different KATs or HDACs contributes to neurological dysfunction and neurodegeneration. HDAC inhibitors have shown promise as a treatment to combat the cognitive decline associated with aging and neurodegenerative disease, as well as to ameliorate the symptoms of depression and posttraumatic stress disorder, among others. In this review, we discuss the evidence for the roles of HDACs in cognitive function as well as in neurological disorders and disease. In particular, we focus on HDAC2, which plays a central role in coupling lysine acetylation to synaptic plasticity and mediates many of the effects of HDAC inhibition in cognition and disease. Copyright © 2014, American Association for the Advancement of Science.

  12. Another twist in the histone memory code.

    Science.gov (United States)

    Josselyn, Sheena; Frankland, Paul W

    2015-02-01

    Transcription is a highly regulated process and several studies have examined the role of transcription factors and various epigenetic regulators in memory formation. In a recent paper in Nature, Zokvic and colleagues show an important role for a novel regulator of chromatin structure (the incorporation of histone variants) in memory formation.

  13. Extracellular Histones Induce Chemokine Production in Whole Blood Ex Vivo and Leukocyte Recruitment In Vivo.

    Science.gov (United States)

    Westman, Johannes; Papareddy, Praveen; Dahlgren, Madelene W; Chakrakodi, Bhavya; Norrby-Teglund, Anna; Smeds, Emanuel; Linder, Adam; Mörgelin, Matthias; Johansson-Lindbom, Bengt; Egesten, Arne; Herwald, Heiko

    2015-12-01

    The innate immune system relies to a great deal on the interaction of pattern recognition receptors with pathogen- or damage-associated molecular pattern molecules. Extracellular histones belong to the latter group and their release has been described to contribute to the induction of systemic inflammatory reactions. However, little is known about their functions in the early immune response to an invading pathogen. Here we show that extracellular histones specifically target monocytes in human blood and this evokes the mobilization of the chemotactic chemokines CXCL9 and CXCL10 from these cells. The chemokine induction involves the toll-like receptor 4/myeloid differentiation factor 2 complex on monocytes, and is under the control of interferon-γ. Consequently, subcutaneous challenge with extracellular histones results in elevated levels of CXCL10 in a murine air pouch model and an influx of leukocytes to the site of injection in a TLR4 dependent manner. When analyzing tissue biopsies from patients with necrotizing fasciitis caused by Streptococcus pyogenes, extracellular histone H4 and CXCL10 are immunostained in necrotic, but not healthy tissue. Collectively, these results show for the first time that extracellular histones have an important function as chemoattractants as their local release triggers the recruitment of immune cells to the site of infection.

  14. dKDM2 couples histone H2A ubiquitylation to histone H3 demethylation during Polycomb group silencing

    NARCIS (Netherlands)

    A. Lagarou (Anna); A.B. Mohd Sarip; Y.M. Moshkin (Yuri); G.E. Chalkley (Gillian); K. Bezstarosti (Karel); J.A.A. Demmers (Jeroen); C.P. Verrijzer (Peter)

    2008-01-01

    textabstractTranscription regulation involves enzyme-mediated changes in chromatin structure. Here, we describe a novel mode of histone crosstalk during gene silencing, in which histone H2A monoubiquitylation is coupled to the removal of histone H3 Lys 36 dimethylation (H3K36me2). This pathway was

  15. Trace metals alter DNA repair and histone modification pathways concurrently in mouse embryonic stem cells.

    Science.gov (United States)

    Gadhia, Sanket R; Calabro, Anthony R; Barile, Frank A

    2012-07-20

    Exposure to metals alters gene expression, changes transcription rates or interferes with DNA repair mechanisms. We tested a hypothesis to determine whether in vitro acute metal exposure, with or without recovery, alters epigenetic pathways in mouse embryonic stem (mES) cells. We measured cell viability, total and histone protein production, changes in gene expression for differentiation and DNA repair, and histone lysine mono-methylation (H3K27me1), in differentiated cells. Confluent differentiated cultures of mES cells were exposed to arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), lithium (Li), mercury (Hg), and nickel (Ni), for 1-h and 24-h, followed by a recovery period. The data demonstrate that maximum cell death occurred during the first few hours of exposure at 24-h IC₅₀ concentrations for all metals. Prolonged in vitro exposure to metals at low concentrations also inhibited protein production and cell proliferation. Subsequently, we determined that metals alter cell differentiation (Oct-4 and egfr) and DNA repair mechanisms (Rad-18, Top-3a and Ogg-1). Interestingly, As, Cd, Hg, and Ni decreased cell proliferation to a greater extent than total histone protein production. Yet, at equivalent concentrations, As and Hg significantly decreased total histone protein production per cell compared to respective controls, suggesting suppression of repair or compensatory mechanisms involving histone pathways. And, acute exposure to As, Cd, Hg and Ni decreased H3K27me1 residue, when compared to control cells. Because activation of cellular differentiation, histone modification, and DNA repair are linked by common transcriptional pathways, and the data propose that metals alter these conduits, then it is reasonable to conclude that trace quantities of metals are capable of suppressing regulation of chromatin structure, cellular differentiation, and controlled cell proliferation in mES cells. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  16. Toward breaking the histone code: bayesian graphical models for histone modifications.

    Science.gov (United States)

    Mitra, Riten; Müller, Peter; Liang, Shoudan; Xu, Yanxun; Ji, Yuan

    2013-08-01

    Histones are proteins that wrap DNA around in small spherical structures called nucleosomes. Histone modifications (HMs) refer to the post-translational modifications to the histone tails. At a particular genomic locus, each of these HMs can either be present or absent, and the combinatory patterns of the presence or absence of multiple HMs, or the histone codes, are believed to coregulate important biological processes. We aim to use raw data on HM markers at different genomic loci to (1) decode the complex biological network of HMs in a single region, and (2) demonstrate how the HM networks differ in different regulatory regions. We suggest that these differences in network attributes form a significant link between histones and genomic functions. We develop a powerful graphical model under the Bayesian paradigm. Posterior inference is fully probabilistic, allowing us to compute the probabilities of distinct dependence patterns of the HMs using graphs. Furthermore, our model-based framework allows for easy but important extensions for inference on differential networks under various conditions, such as the different annotations of the genomic locations (eg, promoters versus insulators). We applied these models to ChIP-Seq data based on CD4+ T lymphocytes. The results confirmed many existing findings and provided a unified tool to generate various promising hypotheses. Differential network analyses revealed new insights on coregulation of HMs of transcriptional activities in different genomic regions. The use of Bayesian graphical models and borrowing strength across different conditions provide high power to infer histone networks and their differences.

  17. Promising antitumor activity with MGCD0103, a novel isotype-selective histone deacetylase inhibitor.

    Science.gov (United States)

    Le Tourneau, Christophe; Siu, Lillian L

    2008-08-01

    Histone deacetylases (HDACs), which target histones as well as non-histone proteins as substrates, have the potential to regulate aberrant gene expression and restore normal growth control in malignancies. This review provides an updated summary of preclinical and clinical experience with the oral isotype-selective HDAC inhibitor MGCD0103 in cancer. Data presented in abstract form from international conferences or journal articles found within a PubMed search of article up to May 2008 are described in this review. MGCD0103 appears tolerable and exhibits favorable pharmacokinetic and pharmacodynamic profiles with evidence of target inhibition in surrogate tissues. Clinical and pharmacodynamic data support a three-times-weekly administration at a 90-mg fixed dose. MGCD0103 displays promising antitumor activity in hematological and lymphoproliferative diseases.

  18. Writers, Readers, and Erasers of Histone Ubiquitylation in DNA Double-Strand Break Repair

    DEFF Research Database (Denmark)

    Smeenk, Godelieve; Mailand, Niels

    2016-01-01

    for a range of genome caretaker proteins and their associated factors. These DNA damage-induced chromatin ubiquitylation marks provide an essential component of a histone code for DSB repair that is controlled by multifaceted regulatory circuits, underscoring its importance for genome stability maintenance...... accurate lesion repair and restoration of genome integrity. In vertebrate cells, ubiquitin-dependent modifications of histones adjacent to DSBs by RNF8, RNF168, and other ubiquitin ligases have a key role in promoting the assembly of repair protein complexes, serving as direct recruitment platforms....... In this review, we provide a comprehensive account of how DSB-induced histone ubiquitylation is sensed, decoded and modulated by an elaborate array of repair factors and regulators. We discuss how these mechanisms impact DSB repair pathway choice and functionality for optimal protection of genome integrity...

  19. Aberrant histone modification in CD19+ B cells of the patients with chronic lymphocytic leukemia

    Directory of Open Access Journals (Sweden)

    Zhou K

    2017-02-01

    Full Text Available Keshu Zhou, Qing Zhang, Yanyan Liu, Yuanyuan Xiong, Shengsheng Wu, Jingke Yang, Hu Zhou, Xinjian Liu, Xudong Wei, Yongping Song Department of Hematology, Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou, People’s Republic of China Abstract: The aim of this study was to detect the alterations in histone methylation and acetylation in patients with chronic lymphocytic leukemia (CLL. Global histone H3/H4 acetylation and H3K4/H3K9 methylation were detected by the EpiQuik™ global histone H3/H4 acetylation and H3K4/H3K9 methylation assay kits. The mRNA expression of selected chromatin modifier genes was measured by real-time polymerase chain reaction (RT-PCR. Our results found that the global histone H3/H4 hypoacetylation in the CD19+ B cells of patients with CLL (P=0.028 and P=0.03, respectively and the global histone H3K9 methylation in patients with CLL were significantly increased compared with controls (P=0.02, while there was no significant difference in the global histone H3K4 methylation between the two groups. The level of SIRT1 and EZH2 mRNA expression was upregulated in patients with CLL (P=0.03 and P=0.02, respectively, which increased significantly with progression from Binet stage A to stage C (P=0.015 and P=0.01, respectively and Rai good to high risk stage (P=0.007 and P=0.008, respectively. The level of HDAC1 and HDAC7 mRNA expression was significantly increased (P=0.02 and P=0.008, respectively and HDAC2 and P300 mRNA expression was reduced in patients with CLL (P=0.002 and P=0.001, respectively. In conclusion, it is observed that the aberrant histone modification plays an important role in the pathogenesis of CLL. Keywords: histone methylation, histone acetylation, SIRT1, EZH2, CLL

  20. Inhibition of mitotic-specific histone phophorylation by sodium arsenite

    Energy Technology Data Exchange (ETDEWEB)

    Cobo, J.M. [Universidad de Alcala de Henares, Madrid (Spain); Valdez, J.G.; Gurley, L.R. [Los Alamos National Lab., NM (United States)

    1994-10-01

    Synchronized cultures of Chinese hamster cells (line CHO) were used to measure the effects of 10{mu}M sodium arsenite on histone phosphorylation. This treatment caused cell proliferation to be temporarily arrested, after which the cells spontaneously resumed cell proliferation in a radiomimetric manner. Immediately following treatment, it was found that sodium arsenite affected only mitotic-specific HI and H3 phosphorylations. Neither interphase, nor mitotic, H2A and H4 phosphorylations were affected, nor was interphase HI Phosphorylation affected. The phosphorylation of HI was inhibited only in mitosis, reducing HI phosphorylation to 38.1% of control levels, which was the level of interphase HI phosphorylation. The phosphorylation of both H3 variants was inhibited in mitosis, the less hydrophobic H3 to 19% and the more hydrophobic H3 to 24% of control levels. These results suggest that sodium arsenite may inhibite cell proliferation by interfering with the cyclin B/p34{sup cdc2} histone kinase activity which is thought to play a key role in regulating the cell cycle. It has been proposed by our laboratory that HI and H3 phosphorylations play a role in restructuring interphase chromatin into metaphase chromosomes. Interference of this process by sodium arsenite may lead to structurally damaged chromosomes resulting in the increased cancer risks known to be produced by arsenic exposure from the environment.

  1. Regulation of replication fork progression through histone supply and demand

    DEFF Research Database (Denmark)

    Groth, Anja; Corpet, Armelle; Cook, Adam J L

    2007-01-01

    DNA replication in eukaryotes requires nucleosome disruption ahead of the replication fork and reassembly behind. An unresolved issue concerns how histone dynamics are coordinated with fork progression to maintain chromosomal stability. Here, we characterize a complex in which the human histone......1 chaperone function, histone supply, and replicative unwinding of DNA in chromatin. We propose that Asf1, as a histone acceptor and donor, handles parental and new histones at the replication fork via an Asf1-(H3-H4)-MCM2-7 intermediate and thus provides a means to fine-tune replication fork...... chaperone Asf1 and MCM2-7, the putative replicative helicase, are connected through a histone H3-H4 bridge. Depletion of Asf1 by RNA interference impedes DNA unwinding at replication sites, and similar defects arise from overproduction of new histone H3-H4 that compromises Asf1 function. These data link Asf...

  2. Quantitative interaction proteomics and genome-wide profiling of epigenetic histone marks and their readers

    DEFF Research Database (Denmark)

    Vermeulen, Michiel; Eberl, H Christian; Matarese, Filomena

    2010-01-01

    Trimethyl-lysine (me3) modifications on histones are the most stable epigenetic marks and they control chromatin-mediated regulation of gene expression. Here, we determine proteins that bind these marks by high-accuracy, quantitative mass spectrometry. These chromatin "readers" are assigned......-lysine sites by specialized complexes appears to be a widespread mechanism to mediate gene expression....

  3. Butyrate induced IGF2 activation correlated with distinct chromatin landscapes due to histone modification

    Science.gov (United States)

    Histone modification has emerged as a very important mechanism regulating the transcriptional status of the genome. Insulin-like growth factor 2 (IGF2) is a peptide hormone controlling various cellular processes such as proliferation and apoptosis. IGF2 and H19 are reciprocally regulated imprinted ...

  4. Elevated levels of circulating histones indicate disease activity in patients with hand, foot, and mouth disease (HFMD).

    Science.gov (United States)

    Li, Xiuhui; Li, Qin; Li, Junhong; Li, Ying; Chen, Yuping; Lv, Aiping; Zhang, Jian; Ding, Jianbo; Von Maltzan, Kristine; Wen, Tao

    2014-12-01

    Hand, foot, and mouth disease (HFMD) is a common infectious disease in children, characterized by acute viral infection accompanying acute inflammatory responses. Circulating histones are leading mediators of the inflammatory processes. This study aimed to elucidate whether circulating histones play a contributory role during HFMD. We measured plasma levels of histones, myeloperoxidase (MPO), lactate dehydrogenase (LDH), and cytokines in HFMD patients (n = 126) and compared the results with those of a control group (n = 30). Circulating histone levels were significantly increased in HFMD patients (3.794 ± 0.156 μg/ml) compared with healthy controls (0.238 ± 0.023 μg/ml, p disease severity (all p disease severity and contribute to systemic inflammation by promoting cytokine production (e.g. IL-6). We suggest that in mild HFMD, circulating histones may originate largely from neutrophil activation, whereas in severe HFMD, dying tissue cells and neutrophil activation may be synergistically involved in the increased levels of histones.

  5. Comparative effects of histone deacetylases inhibitors and resveratrol on Trypanosoma cruzi replication, differentiation, infectivity and gene expression.

    Science.gov (United States)

    Campo, Vanina A

    2017-04-01

    Histone post-translational modification, mediated by histone acetyltransferases and deacetylases, is one of the most studied factors affecting gene expression. Recent data showing differential histone acetylation states during the Trypanosoma cruzi cell cycle suggest a role for epigenetics in the control of this process. As a starting point to study the role of histone deacetylases in the control of gene expression and the consequences of their inhibition and activation in the biology of T. cruzi, two inhibitors for different histone deacetylases: trichostatin A for class I/II and sirtinol for class III and the activator resveratrol for class III, were tested on proliferative and infective forms of this parasite. The two inhibitors tested caused histone hyperacetylation whereas resveratrol showed the opposite effect on both parasite forms, indicating that a biologically active in vivo level of these compounds was achieved. Histone deacetylase inhibitors caused life stage-specific effects, increasing trypomastigotes infectivity and blocking metacyclogenesis. Moreover, these inhibitors affected specific transcript levels, with sirtinol causing the most pronounced change. On the other hand, resveratrol showed strong anti-parasitic effects. This compound diminished epimastigotes growth, promoted metacyclogenesis, reduced in vitro infection and blocked differentiation and/or replication of intracellular amastigotes. In conclusion, the data presented here supports the notion that these compounds can modulate T. cruzi gene expression, differentiation, infection and histones deacetylase activity. Furthermore, among the compounds tested in this study, the results point to Resveratrol as promising trypanocidal drug candidate. Copyright © 2017 The Author. Published by Elsevier Ltd.. All rights reserved.

  6. Inhibition of histone-mediated gene transfer in eucaryotic cells by anti-histone IgG.

    Science.gov (United States)

    Hasselmayer, O; Demirhan, I; Chandra, A; Bayer, M; Müller, R; Chandra, P

    2001-01-01

    In our laboratory, the gene transfer efficiency of some lipofection reagents (lipofectine, lipofectamine, DOTAP and Dosper) and histones H3 and H4 was compared to that of DEAE-Dextran (64). The histones H3 and H4 were found to have the highest transfection efficiency of all the agents tested. In the present study we have analyzed other parameters important for gene delivery by the histones H3 and H4. We transferred the HIV-1 tat gene to Jurkat cells and measured the transactivation of HIV-1-LTR by the transactivator protein, expressed in Jurkat cells. The expression of CAT as a reporter gene hybridized to LTR was a direct measure of transactivation potential. In order to investigate whether the transfection was only due to the positive ionic character of the histones H3 and H4 we tested other histones (H1 and H2A) and polylysine in our system. Under our experimental conditions, neither polylysine, nor the histones H1 and H2A were able to promote gene transfer in Jurkat cells. The inability of these reagents to promote gene transfer was not dependent on DNA condensation; in EMSA (Electrophoretic Mobility Shift Assay) all these reagents exhibited a strong retardation of DNA. In the presence of anti-histone-IgG the transfection potential of histones H3 and H4 was diminished in a concentration - dependent manner. To investigate whether the histone antibodies inhibited the condensation of DNA by histones we carried out gel retardation assays (EMSA) in the absence and in the presence of histone antibodies. Anti-histone-IgG had no effect on the retardation of histone-DNA complexes; on the contrary, retardation was increased. This observation has led us to postulate two models for the possible mechanism by which the histones H3 and H4 catalyze gene transfer in eucaryotic cells.

  7. Structure and function of histone acetyltransferase MOF.

    Science.gov (United States)

    Chen, Qiao Yi; Costa, Max; Sun, Hong

    2015-01-01

    MOF was first identified in Drosophila melanogaster as an important component of the dosage compensation complex. As a member of MYST family of histone acetyltransferase, MOF specifically deposits the acetyl groups to histone H4 lysine 16. Throughout evolution, MOF and its mammalian ortholog have retained highly conserved substrate specificity and similar enzymatic activities. MOF plays important roles in dosage compensation, ESC self-renewal, DNA damage and repair, cell survival, and gene expression regulation. Dysregulation of MOF has been implicated in tumor formation and progression of many types of human cancers. This review will discuss the structure and activity of mammalian hMOF as well as its function in H4K16 acetylation, DNA damage response, stem cell pluripotency, and carcinogenesis.

  8. Probing the acetylation code of histone H4.

    Science.gov (United States)

    Lang, Diana; Schümann, Michael; Gelato, Kathy; Fischle, Wolfgang; Schwarzer, Dirk; Krause, Eberhard

    2013-10-01

    Histone modifications play crucial roles in genome regulation with lysine acetylation being implicated in transcriptional control. Here we report a proteome-wide investigation of the acetylation-dependent protein-protein interactions of the N-terminal tail of histone H4. Quantitative peptide-based affinity MS experiments using the SILAC approach determined the interactomes of H4 tails monoacetylated at the four known acetylation sites K5, K8, K12, and K16, bis-acetylated at K5/K12, triple-acetylated at K8/12/16 and fully tetra-acetylated. A set of 29 proteins was found enriched on the fully acetylated H4 tail while specific binders of the mono and bis-acetylated tails were barely detectable. These observations are in good agreement with earlier reports indicating that the H4 acetylation state establishes its regulatory effects in a cumulative manner rather than via site-specific recruitment of regulatory proteins. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. DeepChrome: deep-learning for predicting gene expression from histone modifications.

    Science.gov (United States)

    Singh, Ritambhara; Lanchantin, Jack; Robins, Gabriel; Qi, Yanjun

    2016-09-01

    Histone modifications are among the most important factors that control gene regulation. Computational methods that predict gene expression from histone modification signals are highly desirable for understanding their combinatorial effects in gene regulation. This knowledge can help in developing 'epigenetic drugs' for diseases like cancer. Previous studies for quantifying the relationship between histone modifications and gene expression levels either failed to capture combinatorial effects or relied on multiple methods that separate predictions and combinatorial analysis. This paper develops a unified discriminative framework using a deep convolutional neural network to classify gene expression using histone modification data as input. Our system, called DeepChrome, allows automatic extraction of complex interactions among important features. To simultaneously visualize the combinatorial interactions among histone modifications, we propose a novel optimization-based technique that generates feature pattern maps from the learnt deep model. This provides an intuitive description of underlying epigenetic mechanisms that regulate genes. We show that DeepChrome outperforms state-of-the-art models like Support Vector Machines and Random Forests for gene expression classification task on 56 different cell-types from REMC database. The output of our visualization technique not only validates the previous observations but also allows novel insights about combinatorial interactions among histone modification marks, some of which have recently been observed by experimental studies. Codes and results are available at www.deepchrome.org yanjun@virginia.edu Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  10. Inhibition of histone binding by supramolecular hosts

    Science.gov (United States)

    Allen, Hillary F.; Daze, Kevin D.; Shimbo, Takashi; Lai, Anne; Musselman, Catherine A.; Sims, Jennifer K.; Wade, Paul A.; Hof†, Fraser; Kutateladze, Tatiana G.

    2015-01-01

    The tandem PHD (plant homeodomain) fingers of the CHD4 (chromodomain helicase DNA-binding protein 4) ATPase are epigenetic readers that bind either unmodified histone H3 tails or H3K9me3 (histone H3 trimethylated at Lys9). This dual function is necessary for the transcriptional and chromatin remodelling activities of the NuRD (nucleosome remodelling and deacetylase) complex. In the present paper, we show that calixarene-based supramolecular hosts disrupt binding of the CHD4 PHD2 finger to H3K9me3, but do not affect the interaction of this protein with the H3K9me0 (unmodified histone H3) tail. A similar inhibitory effect, observed for the association of chromodomain of HP1γ (heterochromatin protein 1γ) with H3K9me3, points to a general mechanism of methyl-lysine caging by calixarenes and suggests a high potential for these compounds in biochemical applications. Immunofluorescence analysis reveals that the supramolecular agents induce changes in chromatin organization that are consistent with their binding to and disruption of H3K9me3 sites in living cells. The results of the present study suggest that the aromatic macrocyclic hosts can be used as a powerful new tool for characterizing methylation-driven epigenetic mechanisms. PMID:24576085

  11. On the origin of the histone fold

    Directory of Open Access Journals (Sweden)

    Söding Johannes

    2007-03-01

    Full Text Available Abstract Background Histones organize the genomic DNA of eukaryotes into chromatin. The four core histone subunits consist of two consecutive helix-strand-helix motifs and are interleaved into heterodimers with a unique fold. We have searched for the evolutionary origin of this fold using sequence and structure comparisons, based on the hypothesis that folded proteins evolved by combination of an ancestral set of peptides, the antecedent domain segments. Results Our results suggest that an antecedent domain segment, corresponding to one helix-strand-helix motif, gave rise divergently to the N-terminal substrate recognition domain of Clp/Hsp100 proteins and to the helical part of the extended ATPase domain found in AAA+ proteins. The histone fold arose subsequently from the latter through a 3D domain-swapping event. To our knowledge, this is the first example of a genetically fixed 3D domain swap that led to the emergence of a protein family with novel properties, establishing domain swapping as a mechanism for protein evolution. Conclusion The helix-strand-helix motif common to these three folds provides support for our theory of an 'ancient peptide world' by demonstrating how an ancestral fragment can give rise to 3 different folds.

  12. dLKR/SDH regulates hormone-mediated histone arginine methylation and transcription of cell death genes.

    Science.gov (United States)

    Cakouros, Dimitrios; Mills, Kathryn; Denton, Donna; Paterson, Alicia; Daish, Tasman; Kumar, Sharad

    2008-08-11

    The sequential modifications of histones form the basis of the histone code that translates into either gene activation or repression. Nuclear receptors recruit a cohort of histone-modifying enzymes in response to ligand binding and regulate proliferation, differentiation, and cell death. In Drosophila melanogaster, the steroid hormone ecdysone binds its heterodimeric receptor ecdysone receptor/ultraspiracle to spatiotemporally regulate the transcription of several genes. In this study, we identify a novel cofactor, Drosophila lysine ketoglutarate reductase (dLKR)/saccharopine dehydrogenase (SDH), that is involved in ecdysone-mediated transcription. dLKR/SDH binds histones H3 and H4 and suppresses ecdysone-mediated transcription of cell death genes by inhibiting histone H3R17me2 mediated by the Drosophila arginine methyl transferase CARMER. Our data suggest that the dynamic recruitment of dLKR/SDH to ecdysone-regulated gene promoters controls the timing of hormone-induced gene expression. In the absence of dLKR/SDH, histone methylation occurs prematurely, resulting in enhanced gene activation. Consistent with these observations, the loss of dLKR/SDH in Drosophila enhances hormone-regulated gene expression, affecting the developmental timing of gene activation.

  13. Identification and characterization of the genes encoding the core histones and histone variants of Neurospora crassa.

    OpenAIRE

    Hays, Shan M; Swanson, Johanna; Eric U Selker

    2002-01-01

    We have identified and characterized the complete complement of genes encoding the core histones of Neurospora crassa. In addition to the previously identified pair of genes that encode histones H3 and H4 (hH3 and hH4-1), we identified a second histone H4 gene (hH4-2), a divergently transcribed pair of genes that encode H2A and H2B (hH2A and hH2B), a homolog of the F/Z family of H2A variants (hH2Az), a homolog of the H3 variant CSE4 from Saccharomyces cerevisiae (hH3v), and a highly diverged ...

  14. Biochemical Analysis Reveals the Multifactorial Mechanism of Histone H3 Clipping by Chicken Liver Histone H3 Protease

    KAUST Repository

    Chauhan, Sakshi

    2016-09-02

    Proteolytic clipping of histone H3 has been identified in many organisms. Despite several studies, the mechanism of clipping, the substrate specificity, and the significance of this poorly understood epigenetic mechanism are not clear. We have previously reported histone H3 specific proteolytic clipping and a protein inhibitor in chicken liver. However, the sites of clipping are still not known very well. In this study, we attempt to identify clipping sites in histone H3 and to determine the mechanism of inhibition by stefin B protein, a cysteine protease inhibitor. By employing site-directed mutagenesis and in vitro biochemical assays, we have identified three distinct clipping sites in recombinant human histone H3 and its variants (H3.1, H3.3, and H3t). However, post-translationally modified histones isolated from chicken liver and Saccharomyces cerevisiae wild-type cells showed different clipping patterns. Clipping of histone H3 N-terminal tail at three sites occurs in a sequential manner. We have further observed that clipping sites are regulated by the structure of the N-terminal tail as well as the globular domain of histone H3. We also have identified the QVVAG region of stefin B protein to be very crucial for inhibition of the protease activity. Altogether, our comprehensive biochemical studies have revealed three distinct clipping sites in histone H3 and their regulation by the structure of histone H3, histone modifications marks, and stefin B.

  15. Krebs cycle intermediates regulate DNA and histone methylation: epigenetic impact on the aging process.

    Science.gov (United States)

    Salminen, Antero; Kauppinen, Anu; Hiltunen, Mikko; Kaarniranta, Kai

    2014-07-01

    Many aging theories have proposed that mitochondria and energy metabolism have a major role in the aging process. There are recent studies indicating that Krebs cycle intermediates can shape the epigenetic landscape of chromatin by regulating DNA and histone methylation. A growing evidence indicates that epigenetics plays an important role in the regulation of healthspan but also is involved in the aging process. 2-Oxoglutarate (α-ketoglutarate) is a key metabolite in the Krebs cycle but it is also an obligatory substrate for 2-oxoglutarate-dependent dioxygenases (2-OGDO). The 2-OGDO enzyme family includes the major enzymes of DNA and histone demethylation, i.e. Ten-Eleven Translocation (TETs) and Jumonji C domain containing (JmjC) demethylases. In addition, 2-OGDO members can regulate collagen synthesis and hypoxic responses in a non-epigenetical manner. Interestingly, succinate and fumarate, also Krebs cycle intermediates, are potent inhibitors of 2-OGDO enzymes, i.e. the balance of Krebs cycle reactions can affect the level of DNA and histone methylation and thus control gene expression. We will review the epigenetic mechanisms through which Krebs cycle intermediates control the DNA and histone methylation. We propose that age-related disturbances in the Krebs cycle function induce stochastic epigenetic changes in chromatin structures which in turn promote the aging process. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. HAMLET interacts with histones and chromatin in tumor cell nuclei.

    Science.gov (United States)

    Düringer, Caroline; Hamiche, Ali; Gustafsson, Lotta; Kimura, Hiroshi; Svanborg, Catharina

    2003-10-24

    HAMLET is a folding variant of human alpha-lactalbumin in an active complex with oleic acid. HAMLET selectively enters tumor cells, accumulates in their nuclei and induces apoptosis-like cell death. This study examined the interactions of HAMLET with nuclear constituents and identified histones as targets. HAMLET was found to bind histone H3 strongly and to lesser extent histones H4 and H2B. The specificity of these interactions was confirmed using BIAcore technology and chromatin assembly assays. In vivo in tumor cells, HAMLET co-localized with histones and perturbed the chromatin structure; HAMLET was found associated with chromatin in an insoluble nuclear fraction resistant to salt extraction. In vitro, HAMLET bound strongly to histones and impaired their deposition on DNA. We conclude that HAMLET interacts with histones and chromatin in tumor cell nuclei and propose that this interaction locks the cells into the death pathway by irreversibly disrupting chromatin organization.

  17. Production and Purification of Antibodies Against Histone Modifications.

    Science.gov (United States)

    Guillemette, Benoit; Hammond-Martel, Ian; Wurtele, Hugo; Verreault, Alain

    2017-01-01

    Antibodies that recognize specific histone modifications are invaluable tools to study chromatin structure and function. There are numerous commercially available antibodies that recognize a remarkable diversity of histone modifications. Unfortunately, many of them fail to work in certain applications or lack the high degree of specificity required of these reagents. The production of affinity-purified polyclonal antibodies against histone modifications demands a little effort but, in return, provides extremely valuable tools that overcome many of the concerns and limitations of commercial antibodies. We present a series of protocols and guidelines for the production and use of large amounts of polyclonal antibodies that recognize modifications of canonical histones. Our protocols can be applied to obtain antibodies that occur in histone variants and proteins other than histones. In addition, some of our protocols are compatible with the production of monoclonal or recombinant antibodies.

  18. Histone H3 tail clipping regulates gene expression

    OpenAIRE

    Santos-Rosa, Helena; Kirmizis, Antonis; Nelson, Christopher; Bartke, Till; Saksouk, Nehme; Cote, Jacques; Kouzarides, Tony

    2008-01-01

    Induction of gene expression in yeast and human cells involves changes in histone modifications associated with promoters. Here we identify a histone H3 endopeptidase activity in S. cerevisiae that may regulate these events. The endopeptidase cleaves H3 after alanine 21, generating a histone lacking the first 21 residues and displays a preference for H3 tails carrying repressive modifications. In vivo, the H3 N-terminus is clipped, specifically within the promoter of genes following the induc...

  19. Cracking the death code: apoptosis-related histone modifications.

    Science.gov (United States)

    Füllgrabe, J; Hajji, N; Joseph, B

    2010-08-01

    The degradation and compaction of chromatin are long-standing hallmark features of apoptosis. The histones, chief protein components of chromatin, are subjected to a wide range of post-translational modifications. An increasing body of evidence suggests that combinations of epigenetic histone modifications influence the overall chromatin structure and have clear functional consequences in cellular processes including apoptosis. This review describes the work to date on the post-translational modification of histones during apoptosis, their regulation by enzymatic complexes and discusses the existence of the apoptotic histone code.

  20. Role of Histone Acetylation in Cell Cycle Regulation.

    Science.gov (United States)

    Koprinarova, Miglena; Schnekenburger, Michael; Diederich, Marc

    2016-01-01

    Core histone acetylation is a key prerequisite for chromatin decondensation and plays a pivotal role in regulation of chromatin structure, function and dynamics. The addition of acetyl groups disturbs histone/DNA interactions in the nucleosome and alters histone/histone interactions in the same or adjacent nucleosomes. Acetyl groups can also provide binding sites for recruitment of bromodomain (BRD)-containing non-histone readers and regulatory complexes to chromatin allowing them to perform distinct downstream functions. The presence of a particular acetylation pattern influences appearance of other histone modifications in the immediate vicinity forming the "histone code". Although the roles of the acetylation of particular lysine residues for the ongoing chromatin functions is largely studied, the epigenetic inheritance of histone acetylation is a debated issue. The dynamics of local or global histone acetylation is associated with fundamental cellular processes such as gene transcription, DNA replication, DNA repair or chromatin condensation. Therefore, it is an essential part of the epigenetic cell response to processes related to internal and external signals.

  1. Genome-wide identification of sweet orange (Citrus sinensis) histone modification gene families and their expression analysis during the fruit development and fruit-blue mold infection process

    Science.gov (United States)

    Xu, Jidi; Xu, Haidan; Liu, Yuanlong; Wang, Xia; Xu, Qiang; Deng, Xiuxin

    2015-01-01

    In eukaryotes, histone acetylation and methylation have been known to be involved in regulating diverse developmental processes and plant defense. These histone modification events are controlled by a series of histone modification gene families. To date, there is no study regarding genome-wide characterization of histone modification related genes in citrus species. Based on the two recent sequenced sweet orange genome databases, a total of 136 CsHMs (Citrus sinensis histone modification genes), including 47 CsHMTs (histone methyltransferase genes), 23 CsHDMs (histone demethylase genes), 50 CsHATs (histone acetyltransferase genes), and 16 CsHDACs (histone deacetylase genes) were identified. These genes were categorized to 11 gene families. A comprehensive analysis of these 11 gene families was performed with chromosome locations, phylogenetic comparison, gene structures, and conserved domain compositions of proteins. In order to gain an insight into the potential roles of these genes in citrus fruit development, 42 CsHMs with high mRNA abundance in fruit tissues were selected to further analyze their expression profiles at six stages of fruit development. Interestingly, a numbers of genes were expressed highly in flesh of ripening fruit and some of them showed the increasing expression levels along with the fruit development. Furthermore, we analyzed the expression patterns of all 136 CsHMs response to the infection of blue mold (Penicillium digitatum), which is the most devastating pathogen in citrus post-harvest process. The results indicated that 20 of them showed the strong alterations of their expression levels during the fruit-pathogen infection. In conclusion, this study presents a comprehensive analysis of the histone modification gene families in sweet orange and further elucidates their behaviors during the fruit development and the blue mold infection responses. PMID:26300904

  2. Genome-wide identification of sweet orange (Citrus sinensis histone modification gene families and their expression analysis during the fruit development and fruit-blue mold infection process

    Directory of Open Access Journals (Sweden)

    Jidi eXu

    2015-08-01

    Full Text Available In eukaryotes, histone acetylation and methylation have been known to be involved in regulating diverse developmental processes and plant defense. These histone modification events are controlled by a series of histone modification gene families. To date, there is no study regarding genome-wide characterization of histone modification related genes in citrus species. Based on the two recent sequenced sweet orange genome databases, a total of 136 CsHMs (Citrus sinensis histone modification genes, including 47 CsHMTs (histone methyltransferase genes, 23 CsHDMs (histone demethylase genes, 50 CsHATs (histone acetyltransferase genes, and 16 CsHDACs (histone deacetylase genes were identified. These genes were categorized to 11 gene families. A comprehensive analysis of these 11 gene families was performed with chromosome locations, phylogenetic comparison, gene structures and conserved domain compositions of proteins. In order to gain an insight into the potential roles of these genes in citrus fruit development, 42 CsHMs with high mRNA abundance in fruit tissues were selected to further analyze their expression profiles at six stages of fruit development. Interestingly, a numbers of genes were expressed highly in flesh of ripening fruit and some of them showed the increasing expression levels along with the fruit development. Furthermore, we analyzed the expression patterns of all 136 CsHMs response to the infection of blue mold (Penicillium digitatum, which is the most devastating pathogen in citrus postharvest process. The results indicated that 20 of them showed the strong alterations of their expression levels during the fruit-pathogen infection. In conclusion, this study presents a comprehensive analysis of the histone modification gene families in sweet orange and further elucidates their behaviors during the fruit development and the blue mold infection responses.

  3. Rapid divergence of histones in Hydrozoa (Cnidaria) and evolution of a novel histone involved in DNA damage response in hydra.

    Science.gov (United States)

    Reddy, Puli Chandramouli; Ubhe, Suyog; Sirwani, Neha; Lohokare, Rasika; Galande, Sanjeev

    2017-08-01

    Histones are fundamental components of chromatin in all eukaryotes. Hydra, an emerging model system belonging to the basal metazoan phylum Cnidaria, provides an ideal platform to understand the evolution of core histone components at the base of eumetazoan phyla. Hydra exhibits peculiar properties such as tremendous regenerative capacity, lack of organismal senescence and rarity of malignancy. In light of the role of histone modifications and histone variants in these processes it is important to understand the nature of histones themselves and their variants in hydra. Here, we report identification of the complete repertoire of histone-coding genes in the Hydra magnipapillata genome. Hydra histones were classified based on their copy numbers, gene structure and other characteristic features. Genomic organization of canonical histone genes revealed the presence of H2A-H2B and H3-H4 paired clusters in high frequency and also a cluster with all core histones along with H1. Phylogenetic analysis of identified members of H2A and H2B histones suggested rapid expansion of these groups in Hydrozoa resulting in the appearance of unique subtypes. Amino acid sequence level comparisons of H2A and H2B forms with bilaterian counterparts suggest the possibility of a highly mobile nature of nucleosomes in hydra. Absolute quantitation of transcripts confirmed the high copy number of histones and supported the canonical nature of H2A. Furthermore, functional characterization of H2A.X.1 and a unique variant H2A.X.2 in the gastric region suggest their role in the maintenance of genome integrity and differentiation processes. These findings provide insights into the evolution of histones and their variants in hydra. Copyright © 2017 Elsevier GmbH. All rights reserved.

  4. histoneHMM : Differential analysis of histone modifications with broad genomic footprints

    NARCIS (Netherlands)

    Heinig, Matthias; Colomé-Tatché, Maria; Taudt, Aaron; Rintisch, Carola; Schafer, Sebastian; Pravenec, Michal; Hubner, Norbert; Vingron, Martin; Johannes, Frank

    2015-01-01

    Background: ChIP-seq has become a routine method for interrogating the genome-wide distribution of various histone modifications. An important experimental goal is to compare the ChIP-seq profiles between an experimental sample and a reference sample, and to identify regions that show differential

  5. Hypothalamic leptin action is mediated by histone deacetylase 5

    DEFF Research Database (Denmark)

    Kabra, Dhiraj G; Pfuhlmann, Katrin; García-Cáceres, Cristina

    2016-01-01

    Hypothalamic leptin signalling has a key role in food intake and energy-balance control and is often impaired in obese individuals. Here we identify histone deacetylase 5 (HDAC5) as a regulator of leptin signalling and organismal energy balance. Global HDAC5 KO mice have increased food intake...... and greater diet-induced obesity when fed high-fat diet. Pharmacological and genetic inhibition of HDAC5 activity in the mediobasal hypothalamus increases food intake and modulates pathways implicated in leptin signalling. We show HDAC5 directly regulates STAT3 localization and transcriptional activity via...... reciprocal STAT3 deacetylation at Lys685 and phosphorylation at Tyr705. In vivo, leptin sensitivity is substantially impaired in HDAC5 loss-of-function mice. Hypothalamic HDAC5 overexpression improves leptin action and partially protects against HFD-induced leptin resistance and obesity. Overall, our data...

  6. Histone Crosstalk between H3S10ph and H4K16ac Generates a Histone Code that Mediates Transcription Elongation

    National Research Council Canada - National Science Library

    Zippo, Alessio; Serafini, Riccardo; Rocchigiani, Marina; Pennacchini, Susanna; Krepelova, Anna; Oliviero, Salvatore

    2009-01-01

    .... This model is based on the histone code hypothesis, where specific histone modifications, acting alone or in combination, can promote or inhibit the binding of a protein (the “reader”) to the nucleosome ( Strahl and Allis, 2000 ). The reader can promote a second histone modification, determining a histone crosstalk which generates a different binding platform ...

  7. The Cac2 subunit is essential for productive histone binding and nucleosome assembly in CAF-1

    Energy Technology Data Exchange (ETDEWEB)

    Mattiroli, Francesca; Gu, Yajie; Balsbaugh, Jeremy L.; Ahn, Natalie G.; Luger, Karolin

    2017-04-18

    Nucleosome assembly following DNA replication controls epigenome maintenance and genome integrity. Chromatin assembly factor 1 (CAF-1) is the histone chaperone responsible for histone (H3-H4)2 deposition following DNA synthesis. Structural and functional details for this chaperone complex and its interaction with histones are slowly emerging. Using hydrogen-deuterium exchange coupled to mass spectrometry, combined with in vitro and in vivo mutagenesis studies, we identified the regions involved in the direct interaction between the yeast CAF-1 subunits, and mapped the CAF-1 domains responsible for H3-H4 binding. The large subunit, Cac1 organizes the assembly of CAF-1. Strikingly, H3-H4 binding is mediated by a composite interface, shaped by Cac1-bound Cac2 and the Cac1 acidic region. Cac2 is indispensable for productive histone binding, while deletion of Cac3 has only moderate effects on H3-H4 binding and nucleosome assembly. These results define direct structural roles for yeast CAF-1 subunits and uncover a previously unknown critical function of the middle subunit in CAF-1.

  8. Integrative Analysis of Histone ChIP-seq and RNA-seq Data.

    Science.gov (United States)

    Klein, Hans-Ulrich; Schäfer, Martin

    2016-07-01

    The R package epigenomix has been designed to detect differentially transcribed gene isoforms that, in addition, exhibit altered histone modifications at their respective genomic loci. The package provides methods to map histone ChIP-seq profiles to isoforms and estimate their transcript abundances from RNA-seq data. Based on the differences observed between case and control samples in the RNA-seq and ChIP-seq data, a correlation measure is calculated for each isoform. The distribution of this correlation measure is further investigated by a Bayesian mixture model to (i) reveal the relationship between the studied histone modification and transcriptional activity, and (ii) detect specific isoforms with differences in both transcription values and histone modifications. The method is designed for experiments with a few or no replicates, and is superior to separate analyses of both data types in that setting. This unit illustrates the integrative analysis of ChIP-seq and RNA-seq data with epigenomix. © 2016 by John Wiley & Sons, Inc. Copyright © 2016 John Wiley & Sons, Inc.

  9. Chemical Probes of Histone Lysine Methyltransferases

    Science.gov (United States)

    2015-01-01

    Growing evidence suggests that histone methyltransferases (HMTs, also known as protein methyltransferases (PMTs)) play an important role in diverse biological processes and human diseases by regulating gene expression and the chromatin state. Therefore, HMTs have been increasingly recognized by the biomedical community as a class of potential therapeutic targets. High quality chemical probes of HMTs, as tools for deciphering their physiological functions and roles in human diseases and testing therapeutic hypotheses, are critical for advancing this promising field. In this review, we focus on the discovery, characterization, and biological applications of chemical probes for HMTs. PMID:25423077

  10. Histone Deacetylase: Therapeutic Targets in Retinal Degeneration.

    Science.gov (United States)

    Daly, Conor; Yin, Jun; Kennedy, Breandán N

    2016-01-01

    Previous studies report that retinitis pigmentosa (RP) patients treated with the histone deacetylase inhibitor (HDACi) valproic acid (VPA) present with improved visual fields and delayed vision loss. However, other studies report poor efficacy and safety of HDACi in other cohorts of retinal degeneration patients. Furthermore, the molecular mechanisms by which HDACi can improve visual function is unknown, albeit HDACi can attenuate pro-apoptotic stimuli and induce expression of neuroprotective factors. Thus, further analysis of HDACi is warranted in pre-clinical models of retinal degeneration including zebrafish. Analysis of HDAC expression in developing zebrafish reveals diverse temporal expression patterns during development and maturation of visual function.

  11. Effect of histone acetylation modification with MGCD0103, a histone deacetylase inhibitor, on nuclear reprogramming and the developmental competence of porcine somatic cell nuclear transfer embryos.

    Science.gov (United States)

    Jin, Long; Zhu, Hai-Ying; Guo, Qing; Li, Xiao-Chen; Zhang, Yu-Chen; Cui, Cheng-Du; Li, Wen-Xue; Cui, Zheng-Yun; Yin, Xi-Jun; Kang, Jin-Dan

    2017-01-01

    Cloning remains as an important technique to enhance the reconstitution and distribution of animal population with high-genetic merit. One of the major detrimental factors of this technique is the abnormal epigenetic modifications. MGCD0103 is known as a histone deacetylase inhibitor. In this study, we investigated the effect of MGCD0103 on the in vitro blastocyst formation rate in porcine somatic cell nuclear transferred (SCNT) embryos and expression in acetylation of the histone H3 lysine 9 and histone H4 lysine 12. We compared the in vitro embryonic development of SCNT embryos treated with different concentrations of MGCD0103 for 24 hours. Our results reported that treating with 0.2-μM MGCD0103 for 24 hours effectively improved the development of SCNT embryos, in comparison to the control group (blastocyst formation rate, 25.5 vs. 10.7%, P MGCD0103 for various intervals after activation. Treatment for 6 hours significantly improved the development of pig SCNT embryos, compared with the control group (blastocyst formation rate, 21.2 vs. 10.5%, P MGCD0103 supplementation significantly (P MGCD0103-treated SCNT embryos were transferred into two surrogate sows, one of whom became pregnant and three fetuses developed. These results suggest that MGCD0103 can enhance the nuclear reprogramming and improve in vitro developmental potential of porcine SCNT embryos. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Hir1p and Hir2p function as transcriptional corepressors to regulate histone gene transcription in the Saccharomyces cerevisiae cell cycle.

    OpenAIRE

    SPECTOR, M.S.; Raff, A; DeSilva, H; K. Lee; Osley, M. A.

    1997-01-01

    The HIR/HPC (histone regulation/histone periodic control) negative regulators play important roles in the transcription of six of the eight core histone genes during the Saccharomyces cerevisiae cell cycle. The phenotypes of hir1 and hir2 mutants suggested that the wild-type HIR1 and HIR2 genes encode transcriptional repressors that function in the absence of direct DNA binding. When Hir1p and Hir2p were artificially tethered to yeast promoters, each protein repressed transcription, suggestin...

  13. Resolving Heart Regeneration by Replacement Histone Profiling.

    Science.gov (United States)

    Goldman, Joseph Aaron; Kuzu, Guray; Lee, Nutishia; Karasik, Jaclyn; Gemberling, Matthew; Foglia, Matthew J; Karra, Ravi; Dickson, Amy L; Sun, Fei; Tolstorukov, Michael Y; Poss, Kenneth D

    2017-02-27

    Chromatin regulation is a principal mechanism governing animal development, yet it is unclear to what extent structural changes in chromatin underlie tissue regeneration. Non-mammalian vertebrates such as zebrafish activate cardiomyocyte (CM) division after tissue damage to regenerate lost heart muscle. Here, we generated transgenic zebrafish expressing a biotinylatable H3.3 histone variant in CMs and derived cell-type-specific profiles of histone replacement. We identified an emerging program of putative enhancers that revise H3.3 occupancy during regeneration, overlaid upon a genome-wide reduction of H3.3 from promoters. In transgenic reporter lines, H3.3-enriched elements directed gene expression in subpopulations of CMs. Other elements increased H3.3 enrichment and displayed enhancer activity in settings of injury- and/or Neuregulin1-elicited CM proliferation. Dozens of consensus sequence motifs containing predicted transcription factor binding sites were enriched in genomic regions with regeneration-responsive H3.3 occupancy. Thus, cell-type-specific regulatory programs of tissue regeneration can be revealed by genome-wide H3.3 profiling. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Histone Methylation and Epigenetic Silencing in Breast Cancer

    Science.gov (United States)

    2011-02-01

    methylation of histone H1 or nucleosomal histone H3, Mol. Cell 14 (2004) 183–193. [64] C. Martin , R. Cao, Y. Zhang, Substrate preferences of the EZH2...101] N.A. Lobo , Y. Shimono, D. Qian, M.F. Clarke, The biology of cancer stem cells, Annu. Rev. Cell Dev. Biol. 23 (2007) 675–699. [102] J. Stingl, C

  15. A Peek into the Complex Realm of Histone Phosphorylation▿

    Science.gov (United States)

    Banerjee, Taraswi; Chakravarti, Debabrata

    2011-01-01

    Although discovered long ago, posttranslational phosphorylation of histones has been in the spotlight only recently. Information is accumulating almost daily on phosphorylation of histones and their roles in cellular physiology and human diseases. An extensive cross talk exists between phosphorylation and other posttranslational modifications, which together regulate various biological processes, including gene transcription, DNA repair, and cell cycle progression. Recent research on histone phosphorylation has demonstrated that nearly all histone types are phosphorylated at specific residues and that these modifications act as a critical intermediate step in chromosome condensation during cell division, transcriptional regulation, and DNA damage repair. As with all young fields, apparently conflicting and sometimes controversial observations about histone phosphorylations and their true functions in different species are found in the literature. Accumulating evidence suggests that instead of functioning strictly as part of a general code, histone phosphorylation probably functions by establishing cross talk with other histone modifications and serving as a platform for recruitment or release of effector proteins, leading to a downstream cascade of events. Here we extensively review published information on the complexities of histone phosphorylation, the roles of proteins recognizing these modifications and the resuting physiological outcome, and, importantly, future challenges and opportunities in this fast-moving field. PMID:22006017

  16. Evidence for sequence biases associated with patterns of histone methylation

    Directory of Open Access Journals (Sweden)

    Wang Zhong

    2012-08-01

    Full Text Available Abstract Background Combinations of histone variants and modifications, conceptually representing a histone code, have been proposed to play a significant role in gene regulation and developmental processes in complex organisms. While various mechanisms have been implicated in establishing and maintaining epigenetic patterns at specific locations in the genome, they are generally believed to be independent of primary DNA sequence on a more global scale. Results To address this systematically in the case of the human genome, we have analyzed primary DNA sequences underlying patterns of 19 different methylated histones in human primary T-cells and patterns of three methylated histones across additional human cell lines. We report strong sequence biases associated with most of these histone marks genome-wide in each cell type. Furthermore, the sequence characteristics for such association are distinct for different groups of histone marks. Conclusions These findings provide evidence of an influence of genomic sequence on patterns of histone modification associated with gene expression and chromatin programming, and they suggest that the mechanisms responsible for global histone modifications may interpret genomic sequence in various ways.

  17. Histone methylation and aging: Lessons learned from model systems

    Science.gov (United States)

    McCauley, Brenna S.; Dang, Weiwei

    2014-01-01

    Aging induces myriad cellular and, ultimately, physiological changes that cause a decline in an organism's functional capabilities. Although the aging process and pathways that regulate it have been extensively studied, only in the last decade have we begun to appreciate that dynamic histone methylation may contribute to this process. In this review, we discuss recent work implicating histone methylation in aging. Loss of certain histone methyltransferases and demethylases changes lifespan in invertebrates, and alterations in histone methylation in aged organisms regulate lifespan and aging phenotypes, including oxidative stress-induced hormesis in yeast, insulin signaling in Caenorhabiditis elegans and mammals, and the senescence-associated secretory phenotype in mammals. In all cases where histone methylation has been shown to impact aging and aging phenotypes, it does so by regulating transcription, suggesting that this is a major mechanism of its action in this context. Histone methylation additionally regulates or is regulated by other cellular pathways that contribute to or combat aging. Given the numerous processes that regulate aging and histone methylation, and are in turn regulated by them, the role of histone methylation in aging is almost certainly underappreciated. PMID:24859460

  18. Co-regulation of histone-modifying enzymes in cancer.

    Directory of Open Access Journals (Sweden)

    Abul B M M K Islam

    Full Text Available Cancer is characterized by aberrant patterns of expression of multiple genes. These major shifts in gene expression are believed to be due to not only genetic but also epigenetic changes. The epigenetic changes are communicated through chemical modifications, including histone modifications. However, it is unclear whether the binding of histone-modifying proteins to genomic regions and the placing of histone modifications efficiently discriminates corresponding genes from the rest of the genes in the human genome. We performed gene expression analysis of histone demethylases (HDMs and histone methyltransferases (HMTs, their target genes and genes with relevant histone modifications in normal and tumor tissues. Surprisingly, this analysis revealed the existence of correlations in the expression levels of different HDMs and HMTs. The observed HDM/HMT gene expression signature was specific to particular normal and cancer cell types and highly correlated with target gene expression and the expression of genes with histone modifications. Notably, we observed that trimethylation at lysine 4 and lysine 27 separated preferentially expressed and underexpressed genes, which was strikingly different in cancer cells compared to normal cells. We conclude that changes in coordinated regulation of enzymes executing histone modifications may underlie global epigenetic changes occurring in cancer.

  19. The Fork in the Road: Histone Partitioning During DNA Replication

    Directory of Open Access Journals (Sweden)

    Anthony T. Annunziato

    2015-06-01

    Full Text Available In the following discussion the distribution of histones at the replication fork is examined, with specific attention paid to the question of H3/H4 tetramer "splitting." After a presentation of early experiments surrounding this topic, more recent contributions are detailed. The implications of these findings with respect to the transmission of histone modifications and epigenetic models are also addressed.

  20. Inhibition of histone deacetylase activity in human endometrial stromal cells promotes extracellular matrix remodelling and limits embryo invasion.

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    Carlos Estella

    Full Text Available Invasion of the trophoblast into the maternal decidua is regulated by both the trophoectoderm and the endometrial stroma, and entails the action of tissue remodeling enzymes. Trophoblast invasion requires the action of metalloproteinases (MMPs to degrade extracellular matrix (ECM proteins and in turn, decidual cells express tissue inhibitors of MMPs (TIMPs. The balance between these promoting and restraining factors is a key event for the successful outcome of pregnancy. Gene expression is post-transcriptionally regulated by histone deacetylases (HDACs that unpacks condensed chromatin activating gene expression. In this study we analyze the effect of histone acetylation on the expression of tissue remodeling enzymes and activity of human endometrial stromal cells (hESCs related to trophoblast invasion control. Treatment of hESCs with the HDAC inhibitor trichostatin A (TSA increased the expression of TIMP-1 and TIMP-3 while decreased MMP-2, MMP-9 and uPA and have an inhibitory effect on trophoblast invasion. Moreover, histone acetylation is detected at the promoters of TIMP-1 and TIMP-3 genes in TSA-treated. In addition, in an in vitro decidualized hESCs model, the increase of TIMP-1 and TIMP-3 expression is associated with histone acetylation at the promoters of these genes. Our results demonstrate that histone acetylation disrupt the balance of ECM modulators provoking a restrain of trophoblast invasion. These findings are important as an epigenetic mechanism that can be used to control trophoblast invasion.

  1. Inhibition of Histone Deacetylase Activity in Human Endometrial Stromal Cells Promotes Extracellular Matrix Remodelling and Limits Embryo Invasion

    Science.gov (United States)

    Atkinson, Stuart P.; Quiñonero, Alicia; Martínez, Sebastián; Pellicer, Antonio; Simón, Carlos

    2012-01-01

    Invasion of the trophoblast into the maternal decidua is regulated by both the trophoectoderm and the endometrial stroma, and entails the action of tissue remodeling enzymes. Trophoblast invasion requires the action of metalloproteinases (MMPs) to degrade extracellular matrix (ECM) proteins and in turn, decidual cells express tissue inhibitors of MMPs (TIMPs). The balance between these promoting and restraining factors is a key event for the successful outcome of pregnancy. Gene expression is post-transcriptionally regulated by histone deacetylases (HDACs) that unpacks condensed chromatin activating gene expression. In this study we analyze the effect of histone acetylation on the expression of tissue remodeling enzymes and activity of human endometrial stromal cells (hESCs) related to trophoblast invasion control. Treatment of hESCs with the HDAC inhibitor trichostatin A (TSA) increased the expression of TIMP-1 and TIMP-3 while decreased MMP-2, MMP-9 and uPA and have an inhibitory effect on trophoblast invasion. Moreover, histone acetylation is detected at the promoters of TIMP-1 and TIMP-3 genes in TSA-treated. In addition, in an in vitro decidualized hESCs model, the increase of TIMP-1 and TIMP-3 expression is associated with histone acetylation at the promoters of these genes. Our results demonstrate that histone acetylation disrupt the balance of ECM modulators provoking a restrain of trophoblast invasion. These findings are important as an epigenetic mechanism that can be used to control trophoblast invasion. PMID:22291969

  2. HMCan-diff: a method to detect changes in histone modifications in cells with different genetic characteristics

    KAUST Repository

    Ashoor, Haitham

    2016-12-19

    Comparing histone modification profiles between cancer and normal states, or across different tumor samples, can provide insights into understanding cancer initiation, progression and response to therapy. ChIP-seq histone modification data of cancer samples are distorted by copy number variation innate to any cancer cell. We present HMCan-diff, the first method designed to analyze ChIP-seq data to detect changes in histone modifications between two cancer samples of different genetic backgrounds, or between a cancer sample and a normal control. HMCan-diff explicitly corrects for copy number bias, and for other biases in the ChIP-seq data, which significantly improves prediction accuracy compared to methods that do not consider such corrections. On in silico simulated ChIP-seq data generated using genomes with differences in copy number profiles, HMCan-diff shows a much better performance compared to other methods that have no correction for copy number bias. Additionally, we benchmarked HMCan-diff on four experimental datasets, characterizing two histone marks in two different scenarios. We correlated changes in histone modifications between a cancer and a normal control sample with changes in gene expression. On all experimental datasets, HMCan-diff demonstrated better performance compared to the other methods.

  3. Vaccination with a plasmid DNA cocktail encoding the nucleosomal histones of Leishmania confers protection against murine cutaneous leishmaniosis.

    Science.gov (United States)

    Iborra, Salvador; Soto, Manuel; Carrión, Javier; Alonso, Carlos; Requena, Jose M

    2004-09-28

    Leishmania histones are relevant immunogens for the host immune system during both Leishmania infection and disease. In the present paper we have evaluated the prophylactic value of the four Leishmania infantum histones forming the nucleosomal core in the murine model of cutaneous leishmaniasis. In a first stage, the immune response elicited by the intramuscular injection of a mixture of four plasmid DNAs, encoding the L. infantum histones H2A, H2B, H3 and H4, was determined in BALB/c mice. It was found that the immunized animals developed a specific Th1 immune response, which was associated with an antigen-specific production of interferon (IFN-gamma) and a limited humoral response against histones (dominated by antibodies of the IgG2a isotype). According to the pure Th1-type immune response elicited by the DNA vaccination with Leishmania histones, vaccinated mice showed a solid immunity that efficiently controlled the Leishmania major infection. The protection in mice vaccinated with histone-DNAs was associated with a low humoral response against leishmanial antigens, an enhanced IFN-gamma production and little, if any, IL-4 production. The relative contribution of both CD8(+) and CD4(+) T cells to the IFN-gamma production, and the IL-12 dependence were also evaluated. All these data indicated that DNA vaccination with Leishmania histones genes results in a specific Th1-like response during L. major infection, and that both CD4(+) and CD8(+) T cells contribute to the resistance of vaccinated mice to cutaneous leishmaniasis.

  4. Acetyl-CoA carboxylase regulates global histone acetylation.

    Science.gov (United States)

    Galdieri, Luciano; Vancura, Ales

    2012-07-06

    Histone acetylation depends on intermediary metabolism for supplying acetyl-CoA in the nucleocytosolic compartment. However, because nucleocytosolic acetyl-CoA is also used for de novo synthesis of fatty acids, histone acetylation and synthesis of fatty acids compete for the same acetyl-CoA pool. The first and rate-limiting reaction in de novo synthesis of fatty acids is carboxylation of acetyl-CoA to form malonyl-CoA, catalyzed by acetyl-CoA carboxylase. In yeast Saccharomyces cerevisiae, acetyl-CoA carboxylase is encoded by the ACC1 gene. In this study, we show that attenuated expression of ACC1 results in increased acetylation of bulk histones, globally increased acetylation of chromatin histones, and altered transcriptional regulation. Together, our data indicate that Acc1p activity regulates the availability of acetyl-CoA for histone acetyltransferases, thus representing a link between intermediary metabolism and epigenetic mechanisms of transcriptional regulation.

  5. The premelting of nucleoprotein: role of non-histone proteins

    Science.gov (United States)

    Wilhelm, F.Xavier; De Murcia, Gilbert M.; Daune, Michel P.

    1974-01-01

    In native nucleoprotein, the premelting structural changes of DNA are not observed by circular dichroism measurements. In order to determine which protein fraction of chromatin is responsible for the absence of premelting we have examined a series of nucleoproteins depleted of different protein fractions by treatment with sodium chloride or sodium deoxycholate. The premelting reappears as soon as non-histone proteins are removed or in residual complexes from which the two slightly lysine-rich histone fractions (F2a2+F2b) have been removed. On the other hand, it is shown that histone F1 alone is not able to suppress the premelting phenomenon. It is thus concluded that the absence of premelting is a property of native nucleoprotein where interactions between the different proteins complexed with DNA can occur and especially between the non-histone proteins and the two slightly lysine-rich histone fractions. PMID:10793734

  6. Epigenetic regulation of motivated behaviors by histone deacetylase inhibitors.

    Science.gov (United States)

    Elvir, Lindsay; Duclot, Florian; Wang, Zuoxin; Kabbaj, Mohamed

    2017-10-08

    Growing evidence has begun to elucidate the contribution of epigenetic mechanisms in the modulation and maintenance of gene expression and behavior. Histone acetylation is one such epigenetic mechanism, which has been shown to profoundly alter gene expression and behaviors. In this review, we begin with an overview of the major epigenetic mechanisms including histones acetylation. We next focus on recent evidence about the influence of environmental stimuli on various motivated behaviors through histone acetylation and highlight how histone deacetylase inhibitors can correct some of the pathologies linked to motivated behaviors including substance abuse, feeding and social attachments. Particularly, we emphasize that the effects of histone deacetylase inhibitors on motivated behaviors are time and context-dependent. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. SET oncoprotein accumulation regulates transcription through DNA demethylation and histone hypoacetylation.

    Science.gov (United States)

    Almeida, Luciana O; Neto, Marinaldo P C; Sousa, Lucas O; Tannous, Maryna A; Curti, Carlos; Leopoldino, Andreia M

    2017-04-18

    Epigenetic modifications are essential in the control of normal cellular processes and cancer development. DNA methylation and histone acetylation are major epigenetic modifications involved in gene transcription and abnormal events driving the oncogenic process. SET protein accumulates in many cancer types, including head and neck squamous cell carcinoma (HNSCC); SET is a member of the INHAT complex that inhibits gene transcription associating with histones and preventing their acetylation. We explored how SET protein accumulation impacts on the regulation of gene expression, focusing on DNA methylation and histone acetylation. DNA methylation profile of 24 tumour suppressors evidenced that SET accumulation decreased DNA methylation in association with loss of 5-methylcytidine, formation of 5-hydroxymethylcytosine and increased TET1 levels, indicating an active DNA demethylation mechanism. However, the expression of some suppressor genes was lowered in cells with high SET levels, suggesting that loss of methylation is not the main mechanism modulating gene expression. SET accumulation also downregulated the expression of 32 genes of a panel of 84 transcription factors, and SET directly interacted with chromatin at the promoter of the downregulated genes, decreasing histone acetylation. Gene expression analysis after cell treatment with 5-aza-2'-deoxycytidine (5-AZA) and Trichostatin A (TSA) revealed that histone acetylation reversed transcription repression promoted by SET. These results suggest a new function for SET in the regulation of chromatin dynamics. In addition, TSA diminished both SET protein levels and SET capability to bind to gene promoter, suggesting that administration of epigenetic modifier agents could be efficient to reverse SET phenotype in cancer.

  8. Histone Modifications in Senescence-Associated Resistance to Apoptosis by Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Yan Y. Sanders

    2013-01-01

    Full Text Available Aging and age-related diseases are associated with cellular senescence that results in variable apoptosis susceptibility to oxidative stress. Although fibroblast senescence has been associated with apoptosis resistance, mechanisms for this have not been well defined. In this report, we studied epigenetic mechanisms involving histone modifications that confer apoptosis resistance to senescent human diploid fibroblasts (HDFs. HDFs that undergo replicative senescence display typical morphological features, express senescence-associated β-galactosidase, and increased levels of the tumor suppressor genes, p16, p21, and caveolin-1. Senescent HDFs are more resistant to oxidative stress (exogenous H2O2-induced apoptosis in comparison to non-senescent (control HDFs; this is associated with constitutively high levels of the anti-apoptotic gene, Bcl-2, and low expression of the pro-apoptotic gene, Bax. Cellular senescence is characterized by global increases in H4K20 trimethylation and decreases in H4K16 acetylation in association with increased activity of Suv420h2 histone methyltransferase (which targets H4K20, decreased activity of the histone acetyltransferase, Mof (which targets H4K16, as well as decreased total histone acetyltransferase activity. In contrast to Bax gene, chromatin immunoprecipitation studies demonstrate marked enrichment of the Bcl-2 gene with H4K16Ac, and depletion with H4K20Me3, predicting active transcription of this gene in senescent HDFs. These data indicate that both global and locus-specific histone modifications of chromatin regulate altered Bcl-2:Bax gene expression in senescent fibroblasts, contributing to its apoptosis-resistant phenotype.

  9. Finding combinatorial histone code by semi-supervised biclustering

    Directory of Open Access Journals (Sweden)

    Teng Li

    2012-07-01

    Full Text Available Abstract Background Combinatorial histone modification is an important epigenetic mechanism for regulating chromatin state and gene expression. Given the rapid accumulation of genome-wide histone modification maps, there is a pressing need for computational methods capable of joint analysis of multiple maps to reveal combinatorial modification patterns. Results We present the Semi-Supervised Coherent and Shifted Bicluster Identification algorithm (SS-CoSBI. It uses prior knowledge of combinatorial histone modifications to guide the biclustering process. Specifically, co-occurrence frequencies of histone modifications characterized by mass spectrometry are used as probabilistic priors to adjust the similarity measure in the biclustering process. Using a high-quality set of transcriptional enhancers and associated histone marks, we demonstrate that SS-CoSBI outperforms its predecessor by finding histone modification and genomic locus biclusters with higher enrichment of enhancers. We apply SS-CoSBI to identify multiple cell-type-specific combinatorial histone modification states associated with human enhancers. We show enhancer histone modification states are correlated with the expression of nearby genes. Further, we find that enhancers with the histone mark H3K4me1 have higher levels of DNA methylation and decreased expression of nearby genes, suggesting a functional interplay between H3K4me1 and DNA methylation that can modulate enhancer activities. Conclusions The analysis presented here provides a systematic characterization of combinatorial histone codes of enhancers across three human cell types using a novel semi-supervised biclustering algorithm. As epigenomic maps accumulate, SS-CoSBI will become increasingly useful for understanding combinatorial chromatin modifications by taking advantage of existing knowledge. Availability and implementation SS-CoSBI is implemented in C. The source code is freely available at http://www.healthcare.uiowa.edu/labs/tan/SS-CoSBI.gz.

  10. Finding combinatorial histone code by semi-supervised biclustering.

    Science.gov (United States)

    Teng, Li; Tan, Kai

    2012-07-03

    Combinatorial histone modification is an important epigenetic mechanism for regulating chromatin state and gene expression. Given the rapid accumulation of genome-wide histone modification maps, there is a pressing need for computational methods capable of joint analysis of multiple maps to reveal combinatorial modification patterns. We present the Semi-Supervised Coherent and Shifted Bicluster Identification algorithm (SS-CoSBI). It uses prior knowledge of combinatorial histone modifications to guide the biclustering process. Specifically, co-occurrence frequencies of histone modifications characterized by mass spectrometry are used as probabilistic priors to adjust the similarity measure in the biclustering process. Using a high-quality set of transcriptional enhancers and associated histone marks, we demonstrate that SS-CoSBI outperforms its predecessor by finding histone modification and genomic locus biclusters with higher enrichment of enhancers. We apply SS-CoSBI to identify multiple cell-type-specific combinatorial histone modification states associated with human enhancers. We show enhancer histone modification states are correlated with the expression of nearby genes. Further, we find that enhancers with the histone mark H3K4me1 have higher levels of DNA methylation and decreased expression of nearby genes, suggesting a functional interplay between H3K4me1 and DNA methylation that can modulate enhancer activities. The analysis presented here provides a systematic characterization of combinatorial histone codes of enhancers across three human cell types using a novel semi-supervised biclustering algorithm. As epigenomic maps accumulate, SS-CoSBI will become increasingly useful for understanding combinatorial chromatin modifications by taking advantage of existing knowledge. SS-CoSBI is implemented in C. The source code is freely available at http://www.healthcare.uiowa.edu/labs/tan/SS-CoSBI.gz.

  11. CTCF induces histone variant incorporation, erases the H3K27me3 histone mark and opens chromatin

    NARCIS (Netherlands)

    O. Weth (Oliver); C. Paprotka (Christine); K. Günther (Katharina); A. Schulte (Astrid); M. Baierl (Manuel); J. Leers (Joerg); N.J. Galjart (Niels); R. Renkawitz (Rainer)

    2014-01-01

    textabstractInsulators functionally separate active chromatin domains frominactive ones. The insulator factor, CTCF, has been found to bind to boundaries and to mediate insulator function. CTCF binding sites are depleted for the histone modification H3K27me3 and are enriched for the histone variant

  12. Interaction between the Chlamydia trachomatis histone H1-like protein (Hc1) and DNA

    DEFF Research Database (Denmark)

    Christiansen, Gunna; Pedersen, LB; Koehler, JF

    1993-01-01

    The gene encoding the Chlamydia trachomatis histone H1-like protein (Hc1) from serovar L2 was cloned into Escherichia coli by use of expression vector pET11d. In this vector, transcription of the gene is under the control of a bacteriophage T7 promoter, and T7 RNA polymerase is inducible in the h......The gene encoding the Chlamydia trachomatis histone H1-like protein (Hc1) from serovar L2 was cloned into Escherichia coli by use of expression vector pET11d. In this vector, transcription of the gene is under the control of a bacteriophage T7 promoter, and T7 RNA polymerase is inducible...

  13. The Histone H2B Monoubiquitination Regulatory Pathway Is Required for Differentiation of Multipotent Stem Cells

    DEFF Research Database (Denmark)

    Karpiuk, Oleksandra; Najafova, Zeynab; Kramer, Frank

    2012-01-01

    understood. We show that histone H2B monoubiquitination (H2Bub1) significantly increases during differentiation of human mesenchymal stem cells (hMSCs) and various lineage-committed precursor cells and in diverse organisms. Furthermore, the H2B ubiquitin ligase RNF40 is required for the induction......Extensive changes in posttranslational histone modifications accompany the rewiring of the transcriptional program during stem cell differentiation. However, the mechanisms controlling the changes in specific chromatin modifications and their function during differentiation remain only poorly...... during the transition from an inactive to an active chromatin conformation. Thus, these data indicate that H2Bub1 is required for maintaining multipotency of hMSCs and plays a central role in controlling stem cell differentiation....

  14. Alcohol Exposure Causes Overexpression of Heart Development-Related Genes by Affecting the Histone H3 Acetylation via BMP Signaling Pathway in Cardiomyoblast Cells.

    Science.gov (United States)

    Shi, Jin; Zhao, Weian; Pan, Bo; Zheng, Min; Si, Lina; Zhu, Jing; Liu, Lingjuan; Tian, Jie

    2017-01-01

    Abusive alcohol utilization of pregnant woman may cause congenital heart disease (CHD) of fetus, where alcohol ignites histone H3 hyperacetylation leading to abnormal development of heart morphogenesis and associated genes. Knowledge about the regularized upstream genes is little, but bone morphogenetic protein (BMP) signaling may actively and prominently take part in alteration in acetylation of histone H3. The supreme objective of this study was to unearth the involvement of BMP signaling pathway in alcohol-driven hyperacetylation of histone H3 in cardiomyoblast cells. Cardiomyoblast cells (H9c2 cells) were addicted with alcohol (100 mM) for 24 hours. Dorsomorphin (5 μM) was used for the inhibition of BMP signaling pathway. We detected the phosphorylation activity of SMAD1/5/8, mRNA expression, histone acetyltransferases (HAT)/histone deacetylase (HDAC) activity, and acetylation of histone H3. Following alcohol exposure, phosphorylation of SMAD1/5/8 and HAT activities was increased to a significant extent, while histone H3 acetylation and expression of heart development-related genes were also increased. The said phenomenon influenced by alcohol was reverted upon dorsomorphin treatment to the cells without effecting HDAC activity. The data clearly identified that BMP-mediated histone H3 acetylation of heart development-related genes might be one of the possible cellular mechanisms to control alcohol-induced expression of heart development-related genes. Dorsomorphin, on the other hand, may modulate alcohol-induced hyperacetylation of histone H3 through BMP targeting, which could be a potential way to block CHD. Copyright © 2016 by the Research Society on Alcoholism.

  15. Recombinant thrombomodulin protects mice against histone-induced lethal thromboembolism.

    Directory of Open Access Journals (Sweden)

    Mayumi Nakahara

    Full Text Available INTRODUCTION: Recent studies have shown that histones, the chief protein component of chromatin, are released into the extracellular space during sepsis, trauma, and ischemia-reperfusion injury, and act as major mediators of the death of an organism. This study was designed to elucidate the cellular and molecular basis of histone-induced lethality and to assess the protective effects of recombinant thrombomodulin (rTM. rTM has been approved for the treatment of disseminated intravascular coagulation (DIC in Japan, and is currently undergoing a phase III clinical trial in the United States. METHODS: Histone H3 levels in plasma of healthy volunteers and patients with sepsis and DIC were measured using enzyme-linked immunosorbent assay. Male C57BL/6 mice were injected intravenously with purified histones, and pathological examinations were performed. The protective effects of rTM against histone toxicity were analyzed both in vitro and in mice. RESULTS: Histone H3 was not detectable in plasma of healthy volunteers, but significant levels were observed in patients with sepsis and DIC. These levels were higher in non-survivors than in survivors. Extracellular histones triggered platelet aggregation, leading to thrombotic occlusion of pulmonary capillaries and subsequent right-sided heart failure in mice. These mice displayed symptoms of DIC, including thrombocytopenia, prolonged prothrombin time, decreased fibrinogen, fibrin deposition in capillaries, and bleeding. Platelet depletion protected mice from histone-induced death in the first 30 minutes, suggesting that vessel occlusion by platelet-rich thrombi might be responsible for death during the early phase. Furthermore, rTM bound to extracellular histones, suppressed histone-induced platelet aggregation, thrombotic occlusion of pulmonary capillaries, and dilatation of the right ventricle, and rescued mice from lethal thromboembolism. CONCLUSIONS: Extracellular histones cause massive

  16. Sperm nuclear histone to protamine ratio in fertile and infertile men: evidence of heterogeneous subpopulations of spermatozoa in the ejaculate.

    Science.gov (United States)

    Zhang, Xiaoyang; San Gabriel, Maria; Zini, Armand

    2006-01-01

    Sperm protamine deficiency is observed in a subset of infertile men, suggesting that the relative histone to protamine ratio may be altered in the spermatozoa of these men. We measured the ratio of nuclear histones to protamines in the spermatozoa of fertile (n = 10) and infertile men (n = 20). Sperm nuclear proteins were extracted and subsequently separated by acid-urea (AU) polyacrylamide gel electrophoresis. The relative histone (H2B) to protamine (PRM1 + PRM2) and PRM1 to PRM2 ratios were estimated by densitometric analysis of the AU gels. Immunoblotting experiments (using H2B, PRM1, and PRM2 antibodies) were conducted to confirm the specificity of the bands. The pattern and intensity of H2B staining in human spermatozoa was assessed by immunocytochemistry. Sperm samples from the infertile men in this study had a significantly higher proportion of histone H2B to protamine (PRM1 + PRM2) than did samples from the fertile men in this study (0.38 vs 0.08, P sperm head. Infertile men had a higher proportion of spermatozoa exhibiting strong and intermediate staining than did samples from fertile men. These findings suggest that infertile men possess a higher proportion of spermatozoa with an increased histone to protamine ratio than fertile controls.

  17. FACT prevents the accumulation of free histones evicted from transcribed chromatin and a subsequent cell cycle delay in G1.

    Directory of Open Access Journals (Sweden)

    Macarena Morillo-Huesca

    2010-05-01

    Full Text Available The FACT complex participates in chromatin assembly and disassembly during transcription elongation. The yeast mutants affected in the SPT16 gene, which encodes one of the FACT subunits, alter the expression of G1 cyclins and exhibit defects in the G1/S transition. Here we show that the dysfunction of chromatin reassembly factors, like FACT or Spt6, down-regulates the expression of the gene encoding the cyclin that modulates the G1 length (CLN3 in START by specifically triggering the repression of its promoter. The G1 delay undergone by spt16 mutants is not mediated by the DNA-damage checkpoint, although the mutation of RAD53, which is otherwise involved in histone degradation, enhances the cell-cycle defects of spt16-197. We reveal how FACT dysfunction triggers an accumulation of free histones evicted from transcribed chromatin. This accumulation is enhanced in a rad53 background and leads to a delay in G1. Consistently, we show that the overexpression of histones in wild-type cells down-regulates CLN3 in START and causes a delay in G1. Our work shows that chromatin reassembly factors are essential players in controlling the free histones potentially released from transcribed chromatin and describes a new cell cycle phenomenon that allows cells to respond to excess histones before starting DNA replication.

  18. Global histone modification of histone H3 in colorectal cancer and its precursor lesions.

    Science.gov (United States)

    Nakazawa, Tadao; Kondo, Tetsuo; Ma, Defu; Niu, Dongfeng; Mochizuki, Kunio; Kawasaki, Tomonori; Yamane, Tetsu; Iino, Hiroshi; Fujii, Hideki; Katoh, Ryohei

    2012-06-01

    Chromatin remodeling through histone modification is an important mechanism of epigenetic gene dysregulation in human cancers. However, little is known about global alteration of histone status during tumorigenesis and cancer progression. Histone H3 status was examined in benign and malignant colorectal tumors by immunohistochemistry and Western blotting. For immunohistochemical evaluation, 4 anti-histone H3 antibodies, specific to dimethylation at lysine 4 (H3K4me2), acetylation at lysine 9 (H3K9ac), dimethylation at lysine 9 (H3K9me2), and trimethylation at lysine 27 (H3K27me3), were used. On immunohistochemistry, H3K4me2, H3K9ac, and H3K27me3 showed no significant changes between normal and colorectal tumors. On the other hand, the global level of H3K9me2 was distinctly higher in neoplastic cells (adenoma and adenocarcinoma) than in normal glandular cells. In addition, it was significantly higher in adenocarcinoma than in adenoma. Correspondingly, Western blotting confirmed that H3K9me2 expression was significantly higher in adenocarcinomas than in normal colorectal mucosa. No alteration of H3K9me2 was observed with tumor differentiation and with the histological subtypes of colorectal cancers. These results suggest that aberration of the global H3K9me2 level is an important epigenetic event in colorectal tumorigenesis and carcinogenesis involved with gene regulation in neoplastic cells through chromatin remodeling. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Targeting histone modifications--epigenetics in cancer.

    Science.gov (United States)

    Waldmann, Tanja; Schneider, Robert

    2013-04-01

    Cancer is one of the most common human diseases. It is long known that mutations in key regulator genes are hallmarks of all cancer types. Apart from these classical genetic pathways there is more and more evidence that also epigenetic alterations are crucially involved in tumourigenesis. In this review we discuss and summarise recent findings of mechanisms responsible for cancer formation apart from the classic genetic mutations. Furthermore, we show how epigenetic and genetic mechanisms could depend on each other and contribute together to cancer formation. We focus mainly on post-translational histone modifications since they are one of the major epigenetic mechanisms regulating gene expression and when they are imbalanced this can result in cancer. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Centromere domain organization and histone modifications

    Directory of Open Access Journals (Sweden)

    P. Bjerling

    2002-05-01

    Full Text Available Centromere function requires the proper coordination of several subfunctions, such as kinetochore assembly, sister chromatid cohesion, binding of kinetochore microtubules, orientation of sister kinetochores to opposite spindle poles, and their movement towards the spindle poles. Centromere structure appears to be organized in different, separable domains in order to accomplish these functions. Despite the conserved nature of centromere functions, the molecular genetic definition of the DNA sequences that form a centromere in the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe, in the fruit fly Drosophila melanogaster, and in humans has revealed little conservation at the level of centromere DNA sequences. Also at the protein level few centromere proteins are conserved in all of these four organisms and many are unique to the different organisms. The recent analysis of the centromere structure in the yeast S. pombe by electron microscopy and detailed immunofluorescence microscopy of Drosophila centromeres have brought to light striking similarities at the overall structural level between these centromeres and the human centromere. The structural organization of the centromere is generally multilayered with a heterochromatin domain and a central core/inner plate region, which harbors the outer plate structures of the kinetochore. It is becoming increasingly clear that the key factors for assembly and function of the centromere structure are the specialized histones and modified histones which are present in the centromeric heterochromatin and in the chromatin of the central core. Thus, despite the differences in the DNA sequences and the proteins that define a centromere, there is an overall structural similarity between centromeres in evolutionarily diverse eukaryotes.

  1. Histone variants of the insect Plodia interpunctella during metamorphosis.

    Science.gov (United States)

    Pataryas, T A; Sekeri-Pataryas, K T; Bonner, W M; Marinou, V A

    1984-01-01

    The pattern of histone variants from the meal moth Plodia interpunctella was compared to the mouse histone variant pattern. Plodia contains histones which comigrate on two dimensional gels with H3.2, H3.3, H4 and H2A.Z in mouse. Plodia H2A.1 and H2B.1 migrate somewhat differently from the respective mouse histones. Comparison of the iodinated tryptic peptides of H2A.1 and H2A.Z from mouse and Plodia showed that the H2A.Z proteins have two iodinated peptides that comigrate in the two species and three more that are different. The H2A.1 proteins in the two species have one iodinated peptide which comigrates and two more which migrate very close to each other. The histone variants from three developmental stages, larval, pupal and adult of Plodia interpunctella were also identified and compared. The same histone variant pattern is found through all stages of development. It is concluded that histone gene expression does not change during metamorphosis in Plodia .

  2. Interpreting the language of histone and DNA modifications.

    Science.gov (United States)

    Rothbart, Scott B; Strahl, Brian D

    2014-08-01

    A major mechanism regulating the accessibility and function of eukaryotic genomes are the covalent modifications to DNA and histone proteins that dependably package our genetic information inside the nucleus of every cell. Formally postulated over a decade ago, it is becoming increasingly clear that post-translational modifications (PTMs) on histones act singly and in combination to form a language or 'code' that is read by specialized proteins to facilitate downstream functions in chromatin. Underappreciated at the time was the level of complexity harbored both within histone PTMs and their combinations, as well as within the proteins that read and interpret the language. In addition to histone PTMs, newly-identified DNA modifications that can recruit specific effector proteins have raised further awareness that histone PTMs operate within a broader language of epigenetic modifications to orchestrate the dynamic functions associated with chromatin. Here, we highlight key recent advances in our understanding of the epigenetic language encompassing histone and DNA modifications and foreshadow challenges that lie ahead as we continue our quest to decipher the fundamental mechanisms of chromatin regulation. This article is part of a Special Issue entitled: Molecular mechanisms of histone modification function. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Histone propionylation is a mark of active chromatin.

    Science.gov (United States)

    Kebede, Adam F; Nieborak, Anna; Shahidian, Lara Zorro; Le Gras, Stephanie; Richter, Florian; Gómez, Diana Aguilar; Baltissen, Marijke P; Meszaros, Gergo; Magliarelli, Helena de Fatima; Taudt, Aaron; Margueron, Raphael; Colomé-Tatché, Maria; Ricci, Romeo; Daujat, Sylvain; Vermeulen, Michiel; Mittler, Gerhard; Schneider, Robert

    2017-12-01

    Histones are highly covalently modified, but the functions of many of these modifications remain unknown. In particular, it is unclear how histone marks are coupled to cellular metabolism and how this coupling affects chromatin architecture. We identified histone H3 Lys14 (H3K14) as a site of propionylation and butyrylation in vivo and carried out the first systematic characterization of histone propionylation. We found that H3K14pr and H3K14bu are deposited by histone acetyltransferases, are preferentially enriched at promoters of active genes and are recognized by acylation-state-specific reader proteins. In agreement with these findings, propionyl-CoA was able to stimulate transcription in an in vitro transcription system. Notably, genome-wide H3 acylation profiles were redefined following changes to the metabolic state, and deletion of the metabolic enzyme propionyl-CoA carboxylase altered global histone propionylation levels. We propose that histone propionylation, acetylation and butyrylation may act in combination to promote high transcriptional output and to couple cellular metabolism with chromatin structure and function.

  4. Histone deacetylase inhibitors promote the tumoricidal effect of HAMLET.

    Science.gov (United States)

    Brest, Patrick; Gustafsson, Mattias; Mossberg, Ann-Kristin; Gustafsson, Lotta; Duringer, Caroline; Hamiche, Ali; Svanborg, Catharina

    2007-12-01

    Histone deacetylase inhibitors (HDIs) and HAMLET (human alpha-lactalbumin made lethal to tumor cells) interact with histones, modify the structure of chromatin, and trigger tumor cell death. This study investigated how the combination of HDIs and HAMLET influences cell viability, histone acetylation, and DNA integrity. The pretreatment of tumor cells with HDIs was shown to enhance the lethal effect of HAMLET and the histone hyperacetylation response to HDIs increased even further after HAMLET treatment. HDIs and HAMLET were shown to target different histone domains as HAMLET bound tailless core histones, whereas HDIs modify the acetylation of the histone tail. DNA damage in response to HAMLET was increased by HDIs. The DNA repair response (p21WAFI expression) was induced by both agonists but abolished when the two agonists were combined. The results suggest that the synergy of HDIs and HAMLET is based on different but converging death pathways, both involving chromatin alterations. We speculate that HAMLET and HDIs might be combined to promote tumor cell death in vivo.

  5. Dysregulation of Histone Acetyltransferases and Deacetylases in Cardiovascular Diseases

    Directory of Open Access Journals (Sweden)

    Yonggang Wang

    2014-01-01

    Full Text Available Cardiovascular disease (CVD remains a leading cause of mortality worldwide despite advances in its prevention and management. A comprehensive understanding of factors which contribute to CVD is required in order to develop more effective treatment options. Dysregulation of epigenetic posttranscriptional modifications of histones in chromatin is thought to be associated with the pathology of many disease models, including CVD. Histone acetyltransferases (HATs and deacetylases (HDACs are regulators of histone lysine acetylation. Recent studies have implicated a fundamental role of reversible protein acetylation in the regulation of CVDs such as hypertension, pulmonary hypertension, diabetic cardiomyopathy, coronary artery disease, arrhythmia, and heart failure. This reversible acetylation is governed by enzymes that HATs add or HDACs remove acetyl groups respectively. New evidence has revealed that histone acetylation regulators blunt cardiovascular and related disease states in certain cellular processes including myocyte hypertrophy, apoptosis, fibrosis, oxidative stress, and inflammation. The accumulating evidence of the detrimental role of histone acetylation in cardiac disease combined with the cardioprotective role of histone acetylation regulators suggests that the use of histone acetylation regulators may serve as a novel approach to treating the millions of patients afflicted by cardiac diseases worldwide.

  6. Germline-specific H1 variants: the "sexy" linker histones.

    Science.gov (United States)

    Pérez-Montero, Salvador; Carbonell, Albert; Azorín, Fernando

    2016-03-01

    The eukaryotic genome is packed into chromatin, a nucleoprotein complex mainly formed by the interaction of DNA with the abundant basic histone proteins. The fundamental structural and functional subunit of chromatin is the nucleosome core particle, which is composed by 146 bp of DNA wrapped around an octameric protein complex formed by two copies of each core histone H2A, H2B, H3, and H4. In addition, although not an intrinsic component of the nucleosome core particle, linker histone H1 directly interacts with it in a monomeric form. Histone H1 binds nucleosomes near the exit/entry sites of linker DNA, determines nucleosome repeat length and stabilizes higher-order organization of nucleosomes into the ∼30 nm chromatin fiber. In comparison to core histones, histone H1 is less well conserved through evolution. Furthermore, histone H1 composition in metazoans is generally complex with most species containing multiple variants that play redundant as well as specific functions. In this regard, a characteristic feature is the presence of specific H1 variants that replace somatic H1s in the germline and during early embryogenesis. In this review, we summarize our current knowledge about their structural and functional properties.

  7. Autoantibodies against Modified Histone Peptides in SLE Patients Are Associated with Disease Activity and Lupus Nephritis.

    Science.gov (United States)

    Dieker, Jürgen; Berden, Jo H; Bakker, Marinka; Briand, Jean-Paul; Muller, Sylviane; Voll, Reinhard; Sjöwall, Christopher; Herrmann, Martin; Hilbrands, Luuk B; van der Vlag, Johan

    2016-01-01

    Persistent exposure of the immune system to death cell debris leads to autoantibodies against chromatin in patients with systemic lupus erythematosus (SLE). Deposition of anti-chromatin/chromatin complexes can instigate inflammation in multiple organs including the kidney. Previously we identified specific cell death-associated histone modifications as targets of autoantibodies in SLE. In this study we addressed, in a large cohort of SLE patients and controls, the question whether plasma reactivities with specific histone peptides associated with serology and clinical features. Plasma from SLE patients with and without lupus nephritis, disease controls, and healthy controls, were tested in ELISA with histone H4 peptide acetylated at lysines 8, 12 and 16 (H4pac), H2B peptide acetylated at lysine 12 (H2Bpac), H3 peptide trimethylated at lysine 27 (H3pme), and their unmodified equivalents. SLE patients displayed a higher reactivity with the modified equivalent of each peptide. Reactivity with H4pac showed both a high sensitivity (89%) and specificity (91%) for SLE, while H2Bpac exhibited a high specificity (96%) but lower sensitivity (69%). Reactivity with H3pme appeared not specific for SLE. Anti-H4pac and anti-H2Bpac reactivity demonstrated a high correlation with disease activity. Moreover, patients reacting with multiple modified histone peptides exhibited higher SLEDAI and lower C3 levels. SLE patients with renal involvement showed higher reactivity with H2B/H2Bpac and a more pronounced reactivity with the modified equivalent of H3pme and H2Bpac. In conclusion, reactivity with H4pac and H2Bpac is specific for SLE patients and correlates with disease activity, whereas reactivity with H2Bpac is in particular associated with lupus nephritis.

  8. [The study on the change of extracellular histones in human plasma during the pathogenesis of silicosis].

    Science.gov (United States)

    Zhang, Yanglin; Cong, Cuicui; Guan, Li; Yu, Jie; Mao, Lijun; Li, Shuqiang; Wen, Tao; Zhao, Jinyuan

    2016-01-01

    To investigate the plasma level of extracellular histones in patients with silicosis, and to explore the role of extracellular histones in the pathogenesis of pulmonary fibrosis in silicosis. Sixty-two patients with silicosis were enrolled as the silicosis group, consisting of 23 patients with stage I silicosis, 25 with stage II silicosis, and 14 with stage III silicosis; sixty workers who had a history of occupational exposure to silica dust for more than 2 years and had not been diagnosed with silicosis were enrolled as the silica dust exposure group; sixty-five healthy workers without a history of occupational exposure to dust were enrolled as healthy controls. Enzyme-linked immunosorbent assay was applied to measure the plasma levels of plasma extracellular histone (H4) and transforming growth factor-β(TGF-β). Compared with healthy controls [(0.82±0.67) μg/ml], the silica dust exposure group[(4.14±2.85) μg/ml] and silicosis group[(9.50±5.04) μg/ml] had significant increases in plasma level of H4 (Psilicosis(r=0.8955, P=0.0388). The silicosis group had a significantly higher plasma level of TGF-β than the silica dust exposure group and healthy controls(P silicosis, the plasma level of H4 was significantly correlated with that of TGF-β(r=0.5375, Psilicosis, and extracellular histones may play an important role in the progression of fibrosis in silicosis.

  9. The histone chaperone complex HIR maintains nucleosome occupancy and counterbalances impaired histone deposition in CAF-1 complex mutants.

    Science.gov (United States)

    Duc, Céline; Benoit, Matthias; Le Goff, Samuel; Simon, Lauriane; Poulet, Axel; Cotterell, Sylviane; Tatout, Christophe; Probst, Aline V

    2015-03-01

    Chromatin organization is essential for coordinated gene expression, genome stability, and inheritance of epigenetic information. The main components involved in chromatin assembly are specific complexes such as Chromatin Assembly Factor 1 (CAF-1) and Histone Regulator (HIR), which deposit histones in a DNA synthesis-dependent or -independent manner, respectively. Here, we characterize the role of the plant orthologs Histone Regulator A (HIRA), Ubinuclein (UBN) and Calcineurin Binding protein 1 (CABIN1), which constitute the HIR complex. Arabidopsis loss-of-function mutants for the various subunits of the complex are viable, but hira mutants show reduced fertility. We show that loss of HIRA reduces extractable histone H3 protein levels and decreases nucleosome occupancy at both actively transcribed genes and heterochromatic regions. Concomitantly, HIRA contributes to maintenance of silencing of pericentromeric repeats and certain transposons. A genetic analysis based on crosses between mutants deficient in subunits of the CAF-1 and HIR complexes showed that simultaneous loss of both the CAF-1 and HIR histone H3 chaperone complexes severely affects plant survival, growth and reproductive development. Our results suggest that HIRA partially rescues impaired histone deposition in fas mutants to preserve nucleosome occupancy, implying plasticity in histone variant interaction and deposition. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

  10. Hypoacetylation, hypomethylation, and dephosphorylation of H2B histones and excessive histone deacetylase activity in DU-145 prostate cancer cells.

    Science.gov (United States)

    Cang, Shundong; Xu, Xiaobin; Ma, Yuehua; Liu, Delong; Chiao, J W

    2016-01-12

    Hypoacetylation on histone H3 of human prostate cancer cells has been described. Little is known about the modifications of other histones from prostate cancer cells. Histones were isolated from the prostate cancer cell line DU-145 and the non-malignant prostatic cell line RC170N/h. Post-translational modifications of histone H2B were determined by liquid chromatography-mass spectrometry (LC-MS)/MS. The histone H2B of the prostate cancer cell line DU-145 was found to have hypoacetylation, hypomethylation, and dephosphorylation as compared to the non-malignant prostatic cell line RC170N/h. H2B regained acetylation on multiple lysine residues, phosphorylation on Thr19, and methylation on Lys23 and Lys43 in the DU-145 cells after sodium butyrate treatment. The histone H2B of DU-145 prostate cancer cells are hypoacetylated, hypomethylated, and dephosphorylated. Histone deacetylase inhibitor reversed this phenotype. Epigenetic agent may therefore be useful for prostate cancer therapy and worth further investigation.

  11. Hypoacetylation, hypomethylation, and dephosphorylation of H2B histones and excessive histone deacetylase activity in DU-145 prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Shundong Cang

    2016-01-01

    Full Text Available Abstract Background Hypoacetylation on histone H3 of human prostate cancer cells has been described. Little is known about the modifications of other histones from prostate cancer cells. Methods Histones were isolated from the prostate cancer cell line DU-145 and the non-malignant prostatic cell line RC170N/h. Post-translational modifications of histone H2B were determined by liquid chromatography-mass spectrometry (LC-MS/MS. Results The histone H2B of the prostate cancer cell line DU-145 was found to have hypoacetylation, hypomethylation, and dephosphorylation as compared to the non-malignant prostatic cell line RC170N/h. H2B regained acetylation on multiple lysine residues, phosphorylation on Thr19, and methylation on Lys23 and Lys43 in the DU-145 cells after sodium butyrate treatment. Conclusions The histone H2B of DU-145 prostate cancer cells are hypoacetylated, hypomethylated, and dephosphorylated. Histone deacetylase inhibitor reversed this phenotype. Epigenetic agent may therefore be useful for prostate cancer therapy and worth further investigation.

  12. Histone deacetylase inhibitor significantly improved the cloning efficiency of porcine somatic cell nuclear transfer embryos.

    Science.gov (United States)

    Huang, Yongye; Tang, Xiaochun; Xie, Wanhua; Zhou, Yan; Li, Dong; Yao, Chaogang; Zhou, Yang; Zhu, Jianguo; Lai, Liangxue; Ouyang, Hongsheng; Pang, Daxin

    2011-12-01

    Valproic acid (VPA), a histone deacetylase inbibitor, has been shown to generate inducible pluripotent stem (iPS) cells from mouse and human fibroblasts with a significant higher efficiency. Because successful cloning by somatic cell nuclear transfer (SCNT) undergoes a full reprogramming process in which the epigenetic state of a differentiated donor nuclear is converted into an embryonic totipotent state, we speculated that VPA would be useful in promoting cloning efficiency. Therefore, in the present study, we examined whether VPA can promote the developmental competence of SCNT embryos by improving the reprogramming state of donor nucleus. Here we report that 1 mM VPA for 14 to 16 h following activation significantly increased the rate of blastocyst formation of porcine SCNT embryos constructed from Landrace fetal fibroblast cells compared to the control (31.8 vs. 11.4%). However, we found that the acetylation level of Histone H3 lysine 14 and Histone H4 lysine 5 and expression level of Oct4, Sox2, and Klf4 was not significantly changed between VPA-treated and -untreated groups at the blastocyst stage. The SCNT embryos were transferred to 38 surrogates, and the cloning efficiency in the treated group was significantly improved compared with the control group. Taken together, we have demonstrated that VPA can improve both in vitro and in vivo development competence of porcine SCNT embryos.

  13. Identification of lysine K18 acetylation on histone H3 peptide using gold nanoparticles' aggregation behaviour.

    Science.gov (United States)

    Li, Ning; Sutarlie, Laura; Lew, Qiao Jing; Chao, Sheng-Hao; Su, Xiaodi

    2016-04-01

    Acetylation of histones, the major protein component of eukaryotic chromosomes, contributes to the epigenetic regulation of gene expression and is also involved in cancer development. A recent study revealed the correlation between tumour formation and acetylation level of lysine K18 on histone H3. In this study, we developed two colorimetric in vitro assays using gold nanoparticles (AuNPs) for identification of lysine K18 acetylation on histone H3 peptide. In assay I, citrate ion-capped AuNP without further modification was employed. Simply mixing the K18 peptide with AuNP solution leads to distinct particle aggregation, relative to that by non-acetylated or lysine K14 acetylated control peptides. In assay II, an AuNP-peptide-antibody composite was synthesized and used as both the sensing probe and the transducing element. By mixing the sample peptides with the composite solution followed by PBS screening, different aggregation behaviours were observed between the K18 acetylated target peptide and the control sequences. Both assays are capable of identifying the acetylated peptides, and also differentiating the distinctive acetylation positions that differ merely by a distance of three amino acids.

  14. Chromatin Dynamics during Nucleotide Excision Repair: Histones on the Move

    Directory of Open Access Journals (Sweden)

    Sophie E. Polo

    2012-09-01

    Full Text Available It has been a long-standing question how DNA damage repair proceeds in a nuclear environment where DNA is packaged into chromatin. Several decades of analysis combining in vitro and in vivo studies in various model organisms ranging from yeast to human have markedly increased our understanding of the mechanisms underlying chromatin disorganization upon damage detection and re-assembly after repair. Here, we review the methods that have been developed over the years to delineate chromatin alterations in response to DNA damage by focusing on the well-characterized Nucleotide Excision Repair (NER pathway. We also highlight how these methods have provided key mechanistic insight into histone dynamics coupled to repair in mammals, raising new issues about the maintenance of chromatin integrity. In particular, we discuss how NER factors and central players in chromatin dynamics such as histone modifiers, nucleosome remodeling factors, and histone chaperones function to mobilize histones during repair.

  15. Can changes in histone acetylation contribute to memory formation?

    Science.gov (United States)

    Lopez-Atalaya, Jose P; Barco, Angel

    2014-12-01

    Neuronal histone acetylation has been postulated to be a mnemonic substrate and a target for memory enhancers and neuropsychiatric drugs. Here we critically evaluate this view and examine the apparent conflict between the proposed instructive role for histone acetylation in memory-related transcription and the insights derived from genomic and genetic studies in other systems. We next discuss the suitability of activity-dependent neuronal histone acetylation as a mnemonic substrate and debate alternative interpretations of current evidence. We believe that further progress in our understanding of the role of histone acetylation and other epigenetic modifications in neuronal plasticity, memory, and neuropsychiatric disorders requires a clear discrimination between cause and effect so that novel epigenetics-related processes can be distinguished from classical transcriptional mechanisms. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. New histone supply regulates replication fork speed and PCNA unloading

    DEFF Research Database (Denmark)

    Mejlvang, Jakob; Feng, Yunpeng; Alabert, Constance

    2014-01-01

    Correct duplication of DNA sequence and its organization into chromatin is central to genome function and stability. However, it remains unclear how cells coordinate DNA synthesis with provision of new histones for chromatin assembly to ensure chromosomal stability. In this paper, we show...... that replication fork speed is dependent on new histone supply and efficient nucleosome assembly. Inhibition of canonical histone biosynthesis impaired replication fork progression and reduced nucleosome occupancy on newly synthesized DNA. Replication forks initially remained stable without activation...... unloading is delayed in the absence of nucleosome assembly. We propose that coupling of fork speed and PCNA unloading to nucleosome assembly provides a simple mechanism to adjust DNA replication and maintain chromatin integrity during transient histone shortage....

  17. Breaking the histone code with quantitative mass spectrometry.

    Science.gov (United States)

    Britton, Laura-Mae P; Gonzales-Cope, Michelle; Zee, Barry M; Garcia, Benjamin A

    2011-10-01

    Histone post-translational modifications (PTMs) comprise one of the most intricate nuclear signaling networks that govern gene expression in a long-term and dynamic fashion. These PTMs are considered to be 'epigenetic' or heritable from one cell generation to the next and help establish genomic expression patterns. While much of the analyses of histones have historically been performed using site-specific antibodies, these methods are replete with technical obstacles (i.e., cross-reactivity and epitope occlusion). Mass spectrometry-based proteomics has begun to play a significant role in the interrogation of histone PTMs, revealing many new aspects of these modifications that cannot be easily determined with standard biological approaches. Here, we review the accomplishments of mass spectrometry in the histone field, and outline the future roadblocks that must be overcome for mass spectrometry-based proteomics to become the method of choice for chromatin biologists.

  18. Physicochemical modifications of histones and their impact on epigenomics.

    Science.gov (United States)

    Andreoli, Federico; Del Rio, Alberto

    2014-09-01

    The study of histone post-translational modifications (PTMs) has made extraordinary progress over the past few years and many epigenetic modifications have been identified and found to be associated with fundamental biological processes and pathological conditions. Most histone-modifying enzymes produce specific covalent modifications on histone tails that, taken together, elicit complex and concerted processes. An even higher level of complexity is generated by the action of small molecules that are able to modulate pharmacologically epigenetic enzymes and interfere with these biochemical mechanisms. In this article, we provide an overview of histone PTMs by reviewing and discussing them in terms of their physicochemical properties, emphasizing these concepts in view of recent research efforts to elucidate epigenetic mechanisms and devise future epigenetic drugs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Chromatin Dynamics during Nucleotide Excision Repair: Histones on the Move

    Science.gov (United States)

    Adam, Salomé; Polo, Sophie E.

    2012-01-01

    It has been a long-standing question how DNA damage repair proceeds in a nuclear environment where DNA is packaged into chromatin. Several decades of analysis combining in vitro and in vivo studies in various model organisms ranging from yeast to human have markedly increased our understanding of the mechanisms underlying chromatin disorganization upon damage detection and re-assembly after repair. Here, we review the methods that have been developed over the years to delineate chromatin alterations in response to DNA damage by focusing on the well-characterized Nucleotide Excision Repair (NER) pathway. We also highlight how these methods have provided key mechanistic insight into histone dynamics coupled to repair in mammals, raising new issues about the maintenance of chromatin integrity. In particular, we discuss how NER factors and central players in chromatin dynamics such as histone modifiers, nucleosome remodeling factors, and histone chaperones function to mobilize histones during repair. PMID:23109890

  20. Specific distribution of the Saccharomyces cerevisiae linker histone homolog HHO1p in the chromatin

    OpenAIRE

    Freidkin, Ilya; Katcoff, Don J.

    2001-01-01

    In virtually all eukaryotic organisms, linker DNA between nucleosomes is associated with a histone termed linker histone or histone H1. In Saccharomyces cerevisiae, HHO1 encodes a putative linker histone with very significant homology to histone H1. The encoded protein is expressed in the nucleus, but has not been shown to affect global chromatin structure, nor has its deletion shown any detectable phenotype. In vitro chromatin assembly experiments with recombinant HHO1p have shown that it is...

  1. Histone H3.3 Mutations: A Variant Path to Cancer

    OpenAIRE

    Yuen, Benjamin T.K.; Knoepfler, Paul S.

    2013-01-01

    A host of cancer types exhibit aberrant histone modifications. Recently, distinct and recurrent mutations in a specific histone variant, histone H3.3, have been implicated in a high proportion of malignant pediatric brain cancers. The presence of mutant H3.3 histone disrupts epigenetic post-translational modifications near genes involved in cancer processes and in brain function. Here, we propose several possible mechanisms by which mutant H3.3 histones may act to promote tumorigenesis. Furth...

  2. Histone variant innovation in a rapidly evolving chordate lineage

    Directory of Open Access Journals (Sweden)

    Jansen Pascal WTC

    2011-07-01

    Full Text Available Abstract Background Histone variants alter the composition of nucleosomes and play crucial roles in transcription, chromosome segregation, DNA repair, and sperm compaction. Modification of metazoan histone variant lineages occurs on a background of genome architecture that shows global similarities from sponges to vertebrates, but the urochordate, Oikopleura dioica, a member of the sister group to vertebrates, exhibits profound modification of this ancestral architecture. Results We show that a histone complement of 47 gene loci encodes 31 histone variants, grouped in distinct sets of developmental expression profiles throughout the life cycle. A particularly diverse array of 15 male-specific histone variants was uncovered, including a testes-specific H4t, the first metazoan H4 sequence variant reported. Universal histone variants H3.3, CenH3, and H2A.Z are present but O. dioica lacks homologs of macroH2A and H2AX. The genome encodes many H2A and H2B variants and the repertoire of H2A.Z isoforms is expanded through alternative splicing, incrementally regulating the number of acetylatable lysine residues in the functionally important N-terminal "charge patch". Mass spectrometry identified 40 acetylation, methylation and ubiquitylation posttranslational modifications (PTMs and showed that hallmark PTMs of "active" and "repressive" chromatin were present in O. dioica. No obvious reduction in silent heterochromatic marks was observed despite high gene density in this extraordinarily compacted chordate genome. Conclusions These results show that histone gene complements and their organization differ considerably even over modest phylogenetic distances. Substantial innovation among all core and linker histone variants has evolved in concert with adaptation of specific life history traits in this rapidly evolving chordate lineage.

  3. Loss of p300 and CBP disrupts histone acetylation at the mouse Sry promoter and causes XY gonadal sex reversal.

    Science.gov (United States)

    Carré, Gwenn-Aël; Siggers, Pam; Xipolita, Marilena; Brindle, Paul; Lutz, Beat; Wells, Sara; Greenfield, Andy

    2018-01-01

    CREB-binding protein (CBP, CREBBP, KAT3A) and its closely related paralogue p300 (EP300, KAT3B), together termed p300/CBP, are histone/lysine acetyl-transferases that control gene expression by modifying chromatin-associated proteins. Here, we report roles for both of these chromatin-modifying enzymes in mouse sex determination, the process by which the embryonic gonad develops into a testis or an ovary. By targeting gene ablation to embryonic gonadal somatic cells using an inducible Cre line, we show that gonads lacking either gene exhibit major abnormalities of XY gonad development at 14.5 dpc, including partial sex reversal. Embryos lacking three out of four functional copies of p300/Cbp exhibit complete XY gonadal sex reversal and have greatly reduced expression of the key testis-determining genes Sry and Sox9. An analysis of histone acetylation at the Sry promoter in mutant gonads at 11.5 dpc shows a reduction in levels of the positive histone mark H3K27Ac. Our data suggest a role for CBP/p300 in testis determination mediated by control of histone acetylation at the Sry locus and reveal a novel element in the epigenetic control of Sry and mammalian sex determination. They also suggest possible novel causes of human disorders of sex development (DSD). © The Author 2017. Published by Oxford University Press.

  4. A 6-alkylsalicylate histone acetyltransferase inhibitor inhibits histone acetylation and pro-inflammatory gene expression in murine precision-cut lung slices

    NARCIS (Netherlands)

    Bosch, van den Thea; Leus, Niek G J; Wapenaar, Hannah; Boichenko, Alexander; Hermans, Jos; Bischoff, Rainer; Haisma, Hidde J; Dekker, Frank J

    Lysine acetylations are post-translational modifications of cellular proteins, that are crucial in the regulation of many cellular processes. Lysine acetylations on histone proteins are part of the epigenetic code regulating gene transcription and are installed by histone acetyltransferases.

  5. A barcode screen for epigenetic regulators reveals a role for the NuB4/HAT-B histone acetyltransferase complex in histone turnover.

    Directory of Open Access Journals (Sweden)

    Kitty F Verzijlbergen

    2011-10-01

    Full Text Available Dynamic modification of histone proteins plays a key role in regulating gene expression. However, histones themselves can also be dynamic, which potentially affects the stability of histone modifications. To determine the molecular mechanisms of histone turnover, we developed a parallel screening method for epigenetic regulators by analyzing chromatin states on DNA barcodes. Histone turnover was quantified by employing a genetic pulse-chase technique called RITE, which was combined with chromatin immunoprecipitation and high-throughput sequencing. In this screen, the NuB4/HAT-B complex, containing the conserved type B histone acetyltransferase Hat1, was found to promote histone turnover. Unexpectedly, the three members of this complex could be functionally separated from each other as well as from the known interacting factor and histone chaperone Asf1. Thus, systematic and direct interrogation of chromatin structure on DNA barcodes can lead to the discovery of genes and pathways involved in chromatin modification and dynamics.

  6. Structural Mechanisms of Nucleosome Recognition by Linker Histones.

    Science.gov (United States)

    Zhou, Bing-Rui; Jiang, Jiansheng; Feng, Hanqiao; Ghirlando, Rodolfo; Xiao, T Sam; Bai, Yawen

    2015-08-20

    Linker histones bind to the nucleosome and regulate the structure of chromatin and gene expression. Despite more than three decades of effort, the structural basis of nucleosome recognition by linker histones remains elusive. Here, we report the crystal structure of the globular domain of chicken linker histone H5 in complex with the nucleosome at 3.5 Å resolution, which is validated using nuclear magnetic resonance spectroscopy. The globular domain sits on the dyad of the nucleosome and interacts with both DNA linkers. Our structure integrates results from mutation analyses and previous cross-linking and fluorescence recovery after photobleach experiments, and it helps resolve the long debate on structural mechanisms of nucleosome recognition by linker histones. The on-dyad binding mode of the H5 globular domain is different from the recently reported off-dyad binding mode of Drosophila linker histone H1. We demonstrate that linker histones with different binding modes could fold chromatin to form distinct higher-order structures. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Alterations of Histone H1 Phosphorylation During Bladder Carcinogenesis

    Science.gov (United States)

    Telu, Kelly H.; Abbaoui, Besma; Thomas-Ahner, Jennifer M.; Zynger, Debra L.; Clinton, Steven K.

    2013-01-01

    There is a crucial need for development of prognostic and predictive biomarkers in human bladder carcinogenesis in order to personalize preventive and therapeutic strategies and improve outcomes. Epigenetic alterations, such as histone modifications, are implicated in the genetic dysregulation that is fundamental to carcinogenesis. Here we focus on profiling the histone modifications during the progression of bladder cancer. Histones were extracted from normal human bladder epithelial cells, an immortalized human bladder epithelial cell line (hTERT), and four human bladder cancer cell lines (RT4, J82, T24, and UMUC3) ranging from superficial low-grade to invasive high-grade cancers. Liquid Chromatography-Mass Spectrometry (LC-MS) profiling revealed a statistically significant increase in phosphorylation of H1 linker histones from normal human bladder epithelial cells to low-grade superficial to high-grade invasive bladder cancer cells. This finding was further validated by immunohistochemical staining of the normal epithelium and transitional cell cancer from human bladders. Cell cycle analysis of histone H1 phosphorylation by western blotting showed an increase of phosphorylation from G0/G1 phase to M phase, again supporting this as a proliferative marker. Changes in histone H1 phosphorylation status may further clarify epigenetic changes during bladder carcinogenesis and provide diagnostic and prognostic biomarkers or targets for future therapeutic interventions. PMID:23675690

  8. Posttranslational Modifications of the Histone 3 Tail and Their Impact on the Activity of Histone Lysine Demethylases In Vitro

    DEFF Research Database (Denmark)

    Lohse, Brian; Helgstrand, Charlotte; Andersson, Jan Legaard

    2013-01-01

    Posttranslational modifications (PTMs) of the histone H3 tail such as methylation, acetylation and phosphorylation play important roles in epigenetic signaling. Here we study the effect of some of these PTMs on the demethylation rates of methylated lysine 9 in vitro using peptide substrates...... mimicking histone H3. Various combinations with other PTMs were employed to study possible cross-talk effects by comparing enzyme kinetic characteristics. We compared the kinetics of histone tail substrates for truncated histone lysine demethylases KDM4A and KDM4C containing only the catalytic core (cc...... are significantly influenced by other PTMs on the same peptide, and emphasizes the importance of studying these interactions at the peptide level to get a more detailed understanding of the dynamics of epigenetic marks....

  9. Histone deacetylase inhibitors repress chondrosarcoma cell proliferation.

    Science.gov (United States)

    Zhu, Jiaxue; Gu, Jianhua; Ma, Jie; Xu, Zhixing; Tao, Hairong

    2015-01-01

    Due to the high resistance to conventional therapy, there is still no convincingly effective treatment for chondrosarcoma. As a promising new treatment strategy, histone deacetylase inhibitors (HDACIs) have been reported to induce cell arrest, apoptosis and differentiation in some kinds of malignancies, but how HDACi exert their effects on chondrosarcoma is not well understood yet. We investigated the effects of HDACIs trichostatin A (TSA) and sodium valproate (VPA) on chondrosarcoma cells in vitro and in vivo. The cell proliferation and cell cycle were examined in two chondrosarcoma cell lines, SW1353 and JJ012, by MTS and flow cytometry assays, respectively. The in vivo effects of HDACIs were investigated by assessing the chondrosarcoma growth in a mouse xenograft model. Our results showed that TSA and VPA significantly repressed the proliferation of chondrosarcoma cells in a concentration-dependent manner. Flow cytometry indicated that TSA arrested the cell cycle in G2/M phase and VPA arrested the cell cycle in G1 phase. The tumor growth was markedly suppressed in mice treated with TSA and VPA. HDACIs significantly repress the proliferation of chondrosarcoma cells in vitro and in vivo. Our findings imply that HDACIs may provide a novel therapeutic target for the treatment of chondrosarcoma.

  10. Intricate Effects of α-Amino and Lysine Modifications on Arginine Methylation of the N-Terminal Tail of Histone H4.

    Science.gov (United States)

    Fulton, Melody D; Zhang, Jing; He, Maomao; Ho, Meng-Chiao; Zheng, Y George

    2017-07-18

    Chemical modifications of the DNA and nucleosomal histones tightly control the gene transcription program in eukaryotic cells. The "histone code" hypothesis proposes that the frequency, combination, and location of post-translational modifications (PTMs) of the core histones compose a complex network of epigenetic regulation. Currently, there are at least 23 different types and >450 histone PTMs that have been discovered, and the PTMs of lysine and arginine residues account for a crucial part of the histone code. Although significant progress has been achieved in recent years, the molecular basis for the histone code is far from being fully understood. In this study, we investigated how naturally occurring N-terminal acetylation and PTMs of histone H4 lysine-5 (H4K5) affect arginine-3 methylation catalyzed by both type I and type II PRMTs at the biochemical level. Our studies found that acylations of H4K5 resulted in decreased levels of arginine methylation by PRMT1, PRMT3, and PRMT8. In contrast, PRMT5 exhibits an increased rate of arginine methylation upon H4K5 acetylation, propionylation, and crotonylation, but not upon H4K5 methylation, butyrylation, or 2-hydroxyisobutyrylation. Methylation of H4K5 did not affect arginine methylation by PRMT1 or PRMT5. There was a small increase in the rate of arginine methylation by PRMT8. Strikingly, a marked increase in the rate of arginine methylation was observed for PRMT3. Finally, N-terminal acetylation reduced the rate of arginine methylation by PRMT3 but had little influence on PRMT1, -5, and -8 activity. These results together highlight the underlying mechanistic differences in substrate recognition among different PRMTs and pave the way for the elucidation of the complex interplay of histone modifications.

  11. [Histone H3 lysine 9 methylation is associated with the expression of hMLH1 and DNA methylation in gastric cancer cells].

    Science.gov (United States)

    Meng, Chun-Feng; Zhu, Xin-Jiang; Peng, Guo

    2008-09-16

    To identify the association of his tone H3 lysine 9 (H3-K9) methylation with DNA methylation and the expression of the mismatch repair gene hMLH1 in human gastric cancer cells. Gastric cancer cells of the lines BGC-823 and MGC-803 were cultured and treated with 5-Aza-2'-deoxycytidine (5-Aza-dC), a demethylation agent, for 72 hour. Chromatin immunoprecipitation (ChIP) assay was used to assess the status of histone H3 lysine 9 methylation in the promoter regions of hMLH1 gene. Methylation-specific PCR (MSP) was used to evaluate the effect of 5-Aza-dC on DNA methylation status. RT-PCR was used to examine the hMLH1 gene expression. In the MGC-803 cells, silenced hMLH1 gene was characterized by DNA methylation and histone H3-K9 hypermethylation; 5-Aza-dC demethylated the DNA and reduced the histone H3-K9 methylation at silenced loci and resulted in reactivation of hMLH1 gene therein. Contrary to the MGC-803 cells, BGC-823 cells expressed hMLH1 gene with DNA demethylation and histone H3-K9 hypomethylation; and 5-Aza-dC had no effects on the gene expression, DNA methylation, and histone H3-K9 methylation therein. Hypermethylation of DNA in the promoter region is related to transcriptional silencing of hMLH1 gene. Histone H3-K9 methylation in different regions of the promoter studied correlates with DNA methylation status of hMLH1 gene in gastric cancer cells. Alteration of DNA methylation affects histone H3-K9 methylation. 5-Aza-dC can control hMLH1 expression, DNA methylation, and histone H3-K9 methylation in the promoter.

  12. A role for CARM1-mediated histone H3 arginine methylation in protecting histone acetylation by releasing corepressors from chromatin.

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    Jing Wu

    Full Text Available Arginine methylation broadly occurs in histones and has been linked to transcriptional regulation, cell cycle regulation and DNA repair. While numerous proteins (histone code effectors that specifically recognize or read the methylated lysine residues in core histones have been identified, little is known for effectors specific for methylated arginines in histones. In this study, we attempted to identify effector(s recognizing asymmetrically methylated R17 and R26 in H3, which are catalyzed by CARM1/PRMT4, through an unbiased biochemical approach. Although we have yet to identify such effector using this approach, we find that these modifications function cooperatively with histone acetylation to inhibit the binding of the nucleosome remodeling and deacetylase complex (NuRD and TIF1 family corepressors to H3 tail in vitro. In support of this finding, we show that overexpression of CARM1 in 293 T cells leads to reduced association of NuRD with chromatin, whereas knockdown of CARM1 in HeLa cells leads to increased association of NuRD with chromatin and decreased level of histone acetylation. Furthermore, in the Carm1-/- MEF cells there is an increased association of NuRD and TIF1β with chromatin and a global decrease in histone acetylation. By chromatin immunoprecipitation assay, we show that overexpression of CARM1 results in reduced association of NuRD complex and TIF1β with an episomal reporter and that CARM1 is required in MEF cells for LPS-induced dissociation of NuRD from a NF-κb target gene. Taking together, our study provides evidence for a role of CARM1-mediated arginine methylation in regulation of histone acetylation and transcription: facilitating transcription by discharging corepressors from chromatin.

  13. The C Terminus of the Histone Chaperone Asf1 Cross-Links to Histone H3 in Yeast and Promotes Interaction with Histones H3 and H4

    OpenAIRE

    Dennehey, Briana K; Noone, Seth; Liu, Wallace H.; Smith, Luke; Churchill, Mair E. A.; Tyler, Jessica K.

    2013-01-01

    The central histone H3/H4 chaperone Asf1 comprises a highly conserved globular core and a divergent C-terminal tail. While the function and structure of the Asf1 core are well known, the function of the tail is less well understood. Here, we have explored the role of the yeast (yAsf1) and human (hAsf1a and hAsf1b) Asf1 tails in Saccharomyces cerevisiae. We show, using a photoreactive, unnatural amino acid, that Asf1 tail residue 210 cross-links to histone H3 in vivo and, furthe...

  14. DNA methylation requires a DNMT1 ubiquitin interacting motif (UIM) and histone ubiquitination.

    Science.gov (United States)

    Qin, Weihua; Wolf, Patricia; Liu, Nan; Link, Stephanie; Smets, Martha; La Mastra, Federica; Forné, Ignasi; Pichler, Garwin; Hörl, David; Fellinger, Karin; Spada, Fabio; Bonapace, Ian Marc; Imhof, Axel; Harz, Hartmann; Leonhardt, Heinrich

    2015-08-01

    DNMT1 is recruited by PCNA and UHRF1 to maintain DNA methylation after replication. UHRF1 recognizes hemimethylated DNA substrates via the SRA domain, but also repressive H3K9me3 histone marks with its TTD. With systematic mutagenesis and functional assays, we could show that chromatin binding further involved UHRF1 PHD binding to unmodified H3R2. These complementation assays clearly demonstrated that the ubiquitin ligase activity of the UHRF1 RING domain is required for maintenance DNA methylation. Mass spectrometry of UHRF1-deficient cells revealed H3K18 as a novel ubiquitination target of UHRF1 in mammalian cells. With bioinformatics and mutational analyses, we identified a ubiquitin interacting motif (UIM) in the N-terminal regulatory domain of DNMT1 that binds to ubiquitinated H3 tails and is essential for DNA methylation in vivo. H3 ubiquitination and subsequent DNA methylation required UHRF1 PHD binding to H3R2. These results show the manifold regulatory mechanisms controlling DNMT1 activity that require the reading and writing of epigenetic marks by UHRF1 and illustrate the multifaceted interplay between DNA and histone modifications. The identification and functional characterization of the DNMT1 UIM suggests a novel regulatory principle and we speculate that histone H2AK119 ubiquitination might also lead to UIM-dependent recruitment of DNMT1 and DNA methylation beyond classic maintenance.

  15. Role of Epigenetic Histone Modifications in Diabetic Kidney Disease Involving Renal Fibrosis

    Directory of Open Access Journals (Sweden)

    Jing Sun

    2017-01-01

    Full Text Available One of the commonest causes of end-stage renal disease is diabetic kidney disease (DKD. Renal fibrosis, characterized by the accumulation of extracellular matrix (ECM proteins in glomerular basement membranes and the tubulointerstitium, is the final manifestation of DKD. The TGF-β pathway triggers epithelial-to-mesenchymal transition (EMT, which plays a key role in the accumulation of ECM proteins in DKD. DCCT/EDIC studies have shown that DKD often persists and progresses despite glycemic control in diabetes once DKD sets in due to prior exposure to hyperglycemia called “metabolic memory.” These imply that epigenetic factors modulate kidney gene expression. There is evidence to suggest that in diabetes and hyperglycemia, epigenetic histone modifications have a significant effect in modulating renal fibrotic and ECM gene expression induced by TGF-β1, as well as its downstream profibrotic genes. Histone modifications are also implicated in renal fibrosis through its ability to regulate the EMT process triggered by TGF-β signaling. In view of this, efforts are being made to develop HAT, HDAC, and HMT inhibitors to delay, stop, or even reverse DKD. In this review, we outline the latest advances that are being made to regulate histone modifications involved in DKD.

  16. Fasting and high-fat diet alter histone deacetylase expression in the medial hypothalamus.

    Directory of Open Access Journals (Sweden)

    Hiromasa Funato

    Full Text Available Increasing attention is now being given to the epigenetic regulation of animal and human behaviors including the stress response and drug addiction. Epigenetic factors also influence feeding behavior and metabolic phenotypes, such as obesity and insulin sensitivity. In response to fasting and high-fat diets, the medial hypothalamus changes the expression of neuropeptides regulating feeding, metabolism, and reproductive behaviors. Histone deacetylases (HDACs are involved in the epigenetic control of gene expression and alter behavior in response to a variety of environmental factors. Here, we examined the expression of HDAC family members in the medial hypothalamus of mice in response to either fasting or a high-fat diet. In response to fasting, HDAC3 and -4 expression levels increased while HDAC10 and -11 levels decreased. Four weeks on a high-fat diet resulted in the increased expression of HDAC5 and -8. Moreover, fasting decreased the number of acetylated histone H3- and acetylated histone H4-positive cells in the ventrolateral subdivision of the ventromedial hypothalamus. Therefore, HDACs may be implicated in altered gene expression profiles in the medial hypothalamus under different metabolic states.

  17. WHSC1 links transcription elongation to HIRA-mediated histone H3.3 deposition

    Science.gov (United States)

    Sarai, Naoyuki; Nimura, Keisuke; Tamura, Tomohiko; Kanno, Tomohiko; Patel, Mira C; Heightman, Tom D; Ura, Kiyoe; Ozato, Keiko

    2013-01-01

    Actively transcribed genes are enriched with the histone variant H3.3. Although H3.3 deposition has been linked to transcription, mechanisms controlling this process remain elusive. We investigated the role of the histone methyltransferase Wolf–Hirschhorn syndrome candidate 1 (WHSC1) (NSD2/MMSET) in H3.3 deposition into interferon (IFN) response genes. IFN treatment triggered robust H3.3 incorporation into activated genes, which continued even after cessation of transcription. Likewise, UV radiation caused H3.3 deposition in UV-activated genes. However, in Whsc1−/− cells IFN- or UV-triggered H3.3 deposition was absent, along with a marked reduction in IFN- or UV-induced transcription. We found that WHSC1 interacted with the bromodomain protein 4 (BRD4) and the positive transcription elongation factor b (P-TEFb) and facilitated transcriptional elongation. WHSC1 also associated with HIRA, the H3.3-specific histone chaperone, independent of BRD4 and P-TEFb. WHSC1 and HIRA co-occupied IFN-stimulated genes and supported prolonged H3.3 incorporation, leaving a lasting transcriptional mark. Our results reveal a previously unrecognized role of WHSC1, which links transcriptional elongation and H3.3 deposition into activated genes through two molecularly distinct pathways. PMID:23921552

  18. Post-translational modifications of linker histone H1 variants in mammals

    Science.gov (United States)

    Starkova, T. Yu; Polyanichko, A. M.; Artamonova, T. O.; Khodorkovskii, M. A.; Kostyleva, E. I.; Chikhirzhina, E. V.; Tomilin, A. N.

    2017-02-01

    The covalent modifications of the linker histone H1 and the core histones are thought to play an important role in the control of chromatin functioning. Histone H1 variants from K562 cell line (hH1), mouse (mH1) and calf (cH1) thymi were studied by matrix-activated laser desorption/ionization fourier transform ion cyclotron resonance mass-spectroscopy (MALDI-FT-ICR-MS). The proteomics analysis revealed novel post-translational modifications of the histone H1, such as meK34-mH1.4, meK35-cH1.1, meK35-mH1.1, meK75-hH1.2, meK75-hH1.3, acK26-hH1.4, acK26-hH1.3 and acK17-hH1.1. The comparison of the hH1, mH1 and cH1 proteins has demonstrated that the types and positions of the post-translational modifications of the globular domains of the H1.2-H1.4 variants are very conservative. However, the post-translational modifications of the N- and C-terminal tails of H1.2, H1.3 and H1.4 are different. The differences of post-translational modifications in the N- and C-terminal tails of H1.2, H1.3 and H1.4 likely lead to the differences in DNA-H1 and H1-protein interactions.

  19. Post-translational modifications of linker histone H1 variants in mammals.

    Science.gov (United States)

    Starkova, T Yu; Polyanichko, A M; Artamonova, T O; Khodorkovskii, M A; Kostyleva, E I; Chikhirzhina, E V; Tomilin, A N

    2017-02-16

    The covalent modifications of the linker histone H1 and the core histones are thought to play an important role in the control of chromatin functioning. Histone H1 variants from K562 cell line (hH1), mouse (mH1) and calf (cH1) thymi were studied by matrix-activated laser desorption/ionization fourier transform ion cyclotron resonance mass-spectroscopy (MALDI-FT-ICR-MS). The proteomics analysis revealed novel post-translational modifications of the histone H1, such as meK34-mH1.4, meK35-cH1.1, meK35-mH1.1, meK75-hH1.2, meK75-hH1.3, acK26-hH1.4, acK26-hH1.3 and acK17-hH1.1. The comparison of the hH1, mH1 and cH1 proteins has demonstrated that the types and positions of the post-translational modifications of the globular domains of the H1.2-H1.4 variants are very conservative. However, the post-translational modifications of the N- and C-terminal tails of H1.2, H1.3 and H1.4 are different. The differences of post-translational modifications in the N- and C-terminal tails of H1.2, H1.3 and H1.4 likely lead to the differences in DNA-H1 and H1-protein interactions.

  20. De novo peptide design and experimental validation of histone methyltransferase inhibitors.

    Directory of Open Access Journals (Sweden)

    James Smadbeck

    Full Text Available Histones are small proteins critical to the efficient packaging of DNA in the nucleus. DNA-protein complexes, known as nucleosomes, are formed when the DNA winds itself around the surface of the histones. The methylation of histone residues by enhancer of zeste homolog 2 (EZH2 maintains gene repression over successive cell generations. Overexpression of EZH2 can silence important tumor suppressor genes leading to increased invasiveness of many types of cancers. This makes the inhibition of EZH2 an important target in the development of cancer therapeutics. We employed a three-stage computational de novo peptide design method to design inhibitory peptides of EZH2. The method consists of a sequence selection stage and two validation stages for fold specificity and approximate binding affinity. The sequence selection stage consists of an integer linear optimization model that was solved to produce a rank-ordered list of amino acid sequences with increased stability in the bound peptide-EZH2 structure. These sequences were validated through the calculation of the fold specificity and approximate binding affinity of the designed peptides. Here we report the discovery of novel EZH2 inhibitory peptides using the de novo peptide design method. The computationally discovered peptides were experimentally validated in vitro using dose titrations and mechanism of action enzymatic assays. The peptide with the highest in vitro response, SQ037, was validated in nucleo using quantitative mass spectrometry-based proteomics. This peptide had an IC50 of 13.5 [Formula: see text]M, demonstrated greater potency as an inhibitor when compared to the native and K27A mutant control peptides, and demonstrated competitive inhibition versus the peptide substrate. Additionally, this peptide demonstrated high specificity to the EZH2 target in comparison to other histone methyltransferases. The validated peptides are the first computationally designed peptides that directly

  1. De novo peptide design and experimental validation of histone methyltransferase inhibitors.

    Directory of Open Access Journals (Sweden)

    James Smadbeck

    Full Text Available Histones are small proteins critical to the efficient packaging of DNA in the nucleus. DNA–protein complexes, known as nucleosomes, are formed when the DNA winds itself around the surface of the histones. The methylation of histone residues by enhancer of zeste homolog 2 (EZH2 maintains gene repression over successive cell generations. Overexpression of EZH2 can silence important tumor suppressor genes leading to increased invasiveness of many types of cancers. This makes the inhibition of EZH2 an important target in the development of cancer therapeutics. We employed a three-stage computational de novo peptide design method to design inhibitory peptides of EZH2. The method consists of a sequence selection stage and two validation stages for fold specificity and approximate binding affinity. The sequence selection stage consists of an integer linear optimization model that was solved to produce a rank-ordered list of amino acid sequences with increased stability in the bound peptide-EZH2 structure. These sequences were validated through the calculation of the fold specificity and approximate binding affinity of the designed peptides. Here we report the discovery of novel EZH2 inhibitory peptides using the de novo peptide design method. The computationally discovered peptides were experimentally validated in vitro using dose titrations and mechanism of action enzymatic assays. The peptide with the highest in vitro response, SQ037, was validated in nucleo using quantitative mass spectrometry-based proteomics. This peptide had an IC50 of 13.5 mM, demonstrated greater potency as an inhibitor when compared to the native and K27A mutant control peptides, and demonstrated competitive inhibition versus the peptide substrate. Additionally, this peptide demonstrated high specificity to the EZH2 target in comparison to other histone methyltransferases. The validated peptides are the first computationally designed peptides that directly inhibit EZH2

  2. WaveSeq: a novel data-driven method of detecting histone modification enrichments using wavelets.

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    Apratim Mitra

    Full Text Available BACKGROUND: Chromatin immunoprecipitation followed by next-generation sequencing is a genome-wide analysis technique that can be used to detect various epigenetic phenomena such as, transcription factor binding sites and histone modifications. Histone modification profiles can be either punctate or diffuse which makes it difficult to distinguish regions of enrichment from background noise. With the discovery of histone marks having a wide variety of enrichment patterns, there is an urgent need for analysis methods that are robust to various data characteristics and capable of detecting a broad range of enrichment patterns. RESULTS: To address these challenges we propose WaveSeq, a novel data-driven method of detecting regions of significant enrichment in ChIP-Seq data. Our approach utilizes the wavelet transform, is free of distributional assumptions and is robust to diverse data characteristics such as low signal-to-noise ratios and broad enrichment patterns. Using publicly available datasets we showed that WaveSeq compares favorably with other published methods, exhibiting high sensitivity and precision for both punctate and diffuse enrichment regions even in the absence of a control data set. The application of our algorithm to a complex histone modification data set helped make novel functional discoveries which further underlined its utility in such an experimental setup. CONCLUSIONS: WaveSeq is a highly sensitive method capable of accurate identification of enriched regions in a broad range of data sets. WaveSeq can detect both narrow and broad peaks with a high degree of accuracy even in low signal-to-noise ratio data sets. WaveSeq is also suited for application in complex experimental scenarios, helping make biologically relevant functional discoveries.

  3. SUMOylated ORC2 Recruits a Histone Demethylase to Regulate Centromeric Histone Modification and Genomic Stability

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    Chao Huang

    2016-04-01

    Full Text Available Origin recognition complex 2 (ORC2, a subunit of the ORC, is essential for DNA replication initiation in eukaryotic cells. In addition to a role in DNA replication initiation at the G1/S phase, ORC2 has been shown to localize to the centromere during the G2/M phase. Here, we show that ORC2 is modified by small ubiquitin-like modifier 2 (SUMO2, but not SUMO1, at the G2/M phase of the cell cycle. SUMO2-modification of ORC2 is important for the recruitment of KDM5A in order to convert H3K4me3 to H3K4me2, a “permissive” histone marker for α-satellite transcription at the centromere. Persistent expression of SUMO-less ORC2 led to reduced α-satellite transcription and impaired pericentric heterochromatin silencing, which resulted in re-replication of heterochromatin DNA. DNA re-replication eventually activated the DNA damage response, causing the bypass of mitosis and the formation of polyploid cells. Thus, ORC2 sustains genomic stability by recruiting KDM5A to maintain centromere histone methylation in order to prevent DNA re-replication.

  4. Post-Training Intrahippocampal Inhibition of Class I Histone Deacetylases Enhances Long-Term Object-Location Memory

    Science.gov (United States)

    Hawk, Joshua D.; Florian, Cedrick; Abel, Ted

    2011-01-01

    Long-term memory formation involves covalent modification of the histone proteins that package DNA. Reducing histone acetylation by mutating histone acetyltransferases impairs long-term memory, and enhancing histone acetylation by inhibiting histone deacetylases (HDACs) improves long-term memory. Previous studies using HDAC inhibitors to enhance…

  5. Histone deacetylase 3 promotes RCAN1 stability and nuclear translocation.

    Science.gov (United States)

    Han, Kyung Ah; Kang, Hye Seon; Lee, Jee Won; Yoo, Lang; Im, Eunju; Hong, Ahyoung; Lee, Yun Ju; Shin, Woo Hyun; Chung, Kwang Chul

    2014-01-01

    Regulator of calcineurin 1 (RCAN1; also referred as DSCR1 or MCIP1) is located in close proximity to a Down syndrome critical region of human chromosome 21. Although RCAN1 is an endogenous inhibitor of calcineurin signaling that controls lymphocyte activation, apoptosis, heart development, skeletal muscle differentiation, and cardiac function, it is not yet clear whether RCAN1 might be involved in other cellular activities. In this study, we explored the extra-functional roles of RCAN1 by searching for novel RCAN1-binding partners. Using a yeast two-hybrid assay, we found that RCAN1 (RCAN1-1S) interacts with histone deacetylase 3 (HDAC3) in mammalian cells. We also demonstrate that HDAC3 deacetylates RCAN1. In addition, HDAC3 increases RCAN1 protein stability by inhibiting its poly-ubiquitination. Furthermore, HDAC3 promotes RCAN1 nuclear translocation. These data suggest that HDAC3, a new binding regulator of RCAN1, affects the protein stability and intracellular localization of RCAN1.

  6. Histone deacetylase 3 promotes RCAN1 stability and nuclear translocation.

    Directory of Open Access Journals (Sweden)

    Kyung Ah Han

    Full Text Available Regulator of calcineurin 1 (RCAN1; also referred as DSCR1 or MCIP1 is located in close proximity to a Down syndrome critical region of human chromosome 21. Although RCAN1 is an endogenous inhibitor of calcineurin signaling that controls lymphocyte activation, apoptosis, heart development, skeletal muscle differentiation, and cardiac function, it is not yet clear whether RCAN1 might be involved in other cellular activities. In this study, we explored the extra-functional roles of RCAN1 by searching for novel RCAN1-binding partners. Using a yeast two-hybrid assay, we found that RCAN1 (RCAN1-1S interacts with histone deacetylase 3 (HDAC3 in mammalian cells. We also demonstrate that HDAC3 deacetylates RCAN1. In addition, HDAC3 increases RCAN1 protein stability by inhibiting its poly-ubiquitination. Furthermore, HDAC3 promotes RCAN1 nuclear translocation. These data suggest that HDAC3, a new binding regulator of RCAN1, affects the protein stability and intracellular localization of RCAN1.

  7. Autophagy induction by histone deacetylase inhibitors inhibits HIV type 1.

    Science.gov (United States)

    Campbell, Grant R; Bruckman, Rachel S; Chu, Yen-Lin; Spector, Stephen A

    2015-02-20

    Histone deacetylase inhibitors (HDACi) are being evaluated in a "shock-and-kill" therapeutic approach to reverse human immunodeficiency virus type-1 (HIV) latency from CD4(+) T cells. Using this approach, HDACi have induced HIV RNA synthesis in latently infected cells from some patients. The hope is that the increase in viral production will lead to killing of the infected cell either by the virus itself or by the patient's immune system, a "sterilizing cure." Although administered within the context of combination antiretroviral therapy, the infection of bystander cells remains a concern. In this study, we investigated the effect of HDACi (belinostat, givinostat, panobinostat, romidepsin, and vorinostat) on the productive infection of macrophages. We demonstrate that the HDACi tested do not alter the initial susceptibility of macrophages to HIV infection. However, we demonstrate that HDACi decrease HIV release from macrophages in a dose-dependent manner (belinostat the canonical autophagy pathway. This mechanism involves unc-51-like autophagy-activating kinase 1 (ULK1) and the inhibition of the mammalian target of rapamycin and requires the formation of autophagosomes and their maturation into autolysosomes in the absence of increased cell death. These data provide further evidence in support of a role for autophagy in the control of HIV infection and suggest that careful consideration of off-target effects will be essential if HDACi are to be a component of a multipronged approach to eliminate latently infected cells. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. Opposing roles of C/EBPbeta and AP-1 in the control of fibroblast proliferation and growth arrest-specific gene expression

    DEFF Research Database (Denmark)

    Gagliardi, Mark; Maynard, Scott; Miyake, Tetsuaki

    2003-01-01

    a proliferative advantage over cells with one or two functional copies of this gene. C/EBP inhibition enhanced the expression of the three major components of AP-1 in cycling CEF, namely c-Jun, JunD, and Fra-2, and stimulated AP-1 activity. In contrast, the over-expression of C/EBPbeta caused a dramatic reduction...... in the levels of AP-1 proteins. Therefore, C/EBPbeta is a negative regulator of AP-1 expression and activity in CEF. The expression of cyclin D1 and cell proliferation were stimulated by the dominant negative mutant of C/EBPbeta but not in the presence of TAM67, a dominant negative mutant of c-Jun and AP-1. CEF...... over-expressing c-Jun, and to a lesser extent JunD and Fra-2, did not growth arrest at high cell density and did not express p20K. Therefore, AP-1 interfered with the action of C/EBPbeta at high cell density, indicating that these factors play opposing roles in the control of GAS gene expression...

  9. Conservation and divergence of the histone code in nucleomorphs.

    Science.gov (United States)

    Marinov, Georgi K; Lynch, Michael

    2016-04-05

    Nucleomorphs, the remnant nuclei of photosynthetic algae that have become endosymbionts to other eukaryotes, represent a unique example of convergent reductive genome evolution in eukaryotes, having evolved independently on two separate occasions in chlorarachniophytes and cryptophytes. The nucleomorphs of the two groups have evolved in a remarkably convergent manner, with numerous very similar features. Chief among them is the extreme reduction and compaction of nucleomorph genomes, with very small chromosomes and extremely short or even completely absent intergenic spaces. These characteristics pose a number of intriguing questions regarding the mechanisms of transcription and gene regulation in such a crowded genomic context, in particular in terms of the functioning of the histone code, which is common to almost all eukaryotes and plays a central role in chromatin biology. This study examines the sequences of nucleomorph histone proteins in order to address these issues. Remarkably, all classical transcription- and repression-related components of the histone code seem to be missing from chlorarachniophyte nucleomorphs. Cryptophyte nucleomorph histones are generally more similar to the conventional eukaryotic state; however, they also display significant deviations from the typical histone code. Based on the analysis of specific components of the code, we discuss the state of chromatin and the transcriptional machinery in these nuclei. The results presented here shed new light on the mechanisms of nucleomorph transcription and gene regulation and provide a foundation for future studies of nucleomorph chromatin and transcriptional biology.

  10. The Functional Analysis of Histone Acetyltransferase MOF in Tumorigenesis.

    Science.gov (United States)

    Su, Jiaming; Wang, Fei; Cai, Yong; Jin, Jingji

    2016-01-14

    Changes in chromatin structure and heritably regulating the gene expression by epigenetic mechanisms, such as histone post-translational modification, are involved in most cellular biological processes. Thus, abnormal regulation of epigenetics is implicated in the occurrence of various diseases, including cancer. Human MOF (males absent on the first) is a member of the MYST (Moz-Ybf2/Sas3-Sas2-Tip60) family of histone acetyltransferases (HATs). As a catalytic subunit, MOF can form at least two distinct multiprotein complexes (MSL and NSL) in human cells. Both complexes can acetylate histone H4 at lysine 16 (H4K16); however, the NSL complex possesses broader substrate specificity and can also acetylate histone H4 at lysines 5 and 8 (H4K5 and H4K8), suggesting the complexity of the intracellular functions of MOF. Silencing of MOF in cells leads to genomic instability, inactivation of gene transcription, defective DNA damage repair and early embryonic lethality. Unbalanced MOF expression and its corresponding acetylation of H4K16 have been found in certain primary cancer tissues, including breast cancer, medulloblastoma, ovarian cancer, renal cell carcinoma, colorectal carcinoma, gastric cancer, as well as non-small cell lung cancer. In this review, we provide a brief overview of MOF and its corresponding histone acetylation, introduce recent research findings that link MOF functions to tumorigenesis and speculate on the potential role that may be relevant to tumorigenic pathways.

  11. The Functional Analysis of Histone Acetyltransferase MOF in Tumorigenesis

    Directory of Open Access Journals (Sweden)

    Jiaming Su

    2016-01-01

    Full Text Available Changes in chromatin structure and heritably regulating the gene expression by epigenetic mechanisms, such as histone post-translational modification, are involved in most cellular biological processes. Thus, abnormal regulation of epigenetics is implicated in the occurrence of various diseases, including cancer. Human MOF (males absent on the first is a member of the MYST (Moz-Ybf2/Sas3-Sas2-Tip60 family of histone acetyltransferases (HATs. As a catalytic subunit, MOF can form at least two distinct multiprotein complexes (MSL and NSL in human cells. Both complexes can acetylate histone H4 at lysine 16 (H4K16; however, the NSL complex possesses broader substrate specificity and can also acetylate histone H4 at lysines 5 and 8 (H4K5 and H4K8, suggesting the complexity of the intracellular functions of MOF. Silencing of MOF in cells leads to genomic instability, inactivation of gene transcription, defective DNA damage repair and early embryonic lethality. Unbalanced MOF expression and its corresponding acetylation of H4K16 have been found in certain primary cancer tissues, including breast cancer, medulloblastoma, ovarian cancer, renal cell carcinoma, colorectal carcinoma, gastric cancer, as well as non-small cell lung cancer. In this review, we provide a brief overview of MOF and its corresponding histone acetylation, introduce recent research findings that link MOF functions to tumorigenesis and speculate on the potential role that may be relevant to tumorigenic pathways.

  12. Single-nucleosome mapping of histone modifications in S. cerevisiae.

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    Chih Long Liu

    2005-10-01

    Full Text Available Covalent modification of histone proteins plays a role in virtually every process on eukaryotic DNA, from transcription to DNA repair. Many different residues can be covalently modified, and it has been suggested that these modifications occur in a great number of independent, meaningful combinations. Published low-resolution microarray studies on the combinatorial complexity of histone modification patterns suffer from confounding effects caused by the averaging of modification levels over multiple nucleosomes. To overcome this problem, we used a high-resolution tiled microarray with single-nucleosome resolution to investigate the occurrence of combinations of 12 histone modifications on thousands of nucleosomes in actively growing S. cerevisiae. We found that histone modifications do not occur independently; there are roughly two groups of co-occurring modifications. One group of lysine acetylations shows a sharply defined domain of two hypo-acetylated nucleosomes, adjacent to the transcriptional start site, whose occurrence does not correlate with transcription levels. The other group consists of modifications occurring in gradients through the coding regions of genes in a pattern associated with transcription. We found no evidence for a deterministic code of many discrete states, but instead we saw blended, continuous patterns that distinguish nucleosomes at one location (e.g., promoter nucleosomes from those at another location (e.g., over the 3' ends of coding regions. These results are consistent with the idea of a simple, redundant histone code, in which multiple modifications share the same role.

  13. The Histone Demethylase Jhdm1a Regulates Hepatic Gluconeogenesis

    Science.gov (United States)

    Zou, Tie; Yao, Annie Y.; Cooper, Marcus P.; Boyartchuk, Victor; Wang, Yong-Xu

    2012-01-01

    Hepatic gluconeogenesis is required for maintaining blood glucose homeostasis; yet, in diabetes mellitus, this process is unrestrained and is a major contributor to fasting hyperglycemia. To date, the impacts of chromatin modifying enzymes and chromatin landscape on gluconeogenesis are poorly understood. Through catalyzing the removal of methyl groups from specific lysine residues in the histone tail, histone demethylases modulate chromatin structure and, hence, gene expression. Here we perform an RNA interference screen against the known histone demethylases and identify a histone H3 lysine 36 (H3K36) demethylase, Jhdm1a, as a key negative regulator of gluconeogenic gene expression. In vivo, silencing of Jhdm1a promotes liver glucose synthesis, while its exogenous expression reduces blood glucose level. Importantly, the regulation of gluconeogenesis by Jhdm1a requires its demethylation activity. Mechanistically, we find that Jhdm1a regulates the expression of a major gluconeogenic regulator, C/EBPα. This is achieved, at least in part, by its USF1-dependent association with the C/EBPα promoter and its subsequent demethylation of dimethylated H3K36 on the C/EBPα locus. Our work provides compelling evidence that links histone demethylation to transcriptional regulation of gluconeogenesis and has important implications for the treatment of diabetes. PMID:22719268

  14. The Histone H3 Acetylase dGcn5 Is a Key Player in Drosophila melanogaster Metamorphosis

    Science.gov (United States)

    Carré, Clément; Szymczak, Dimitri; Pidoux, Josette; Antoniewski, Christophe

    2005-01-01

    Although it has been well established that histone acetyltransferases (HATs) are involved in the modulation of chromatin structure and gene transcription, there is only little information on their developmental role in higher organisms. Gcn5 was the first transcription factor with HAT activity identified in eukaryotes. Here we report the isolation and characterization of Drosophila melanogaster dGcn5 mutants. Null dGcn5 alleles block the onset of both oogenesis and metamorphosis, while hypomorphic dGcn5 alleles impair the formation of adult appendages and cuticle. Strikingly, the dramatic loss of acetylation of the K9 and K14 lysine residues of histone H3 in dGcn5 mutants has no noticeable effect on larval tissues. In contrast, strong cell proliferation defects in imaginal tissues are observed. In vivo complementation experiments revealed that dGcn5 integrates specific functions in addition to chromosome binding and acetylation. Surprisingly, a dGcn5 variant protein with a deletion of the bromodomain, which has been shown to recognize acetylated histones, appears to be fully functional. Our results establish dGcn5 as a major histone H3 acetylase in Drosophila which plays a key role in the control of specific morphogenetic cascades during developmental transitions. PMID:16135811

  15. Postweaning exposure to a high-fat diet is associated with alterations to the hepatic histone code in Japanese macaques.

    Science.gov (United States)

    Suter, Melissa A; Takahashi, Diana; Grove, Kevin L; Aagaard, Kjersti M

    2013-09-01

    Expression of circadian gene, Npas2, is altered in fetal life with maternal high-fat (HF) diet exposure by virtue of alterations in the fetal histone code. We postulated that these disruptions would persist postnatally. Pregnant macaques were fed a control (CTR) or HF diet and delivered at term. When offspring were weaned, they were placed on either CTR or HF diet for a period of 5 mo to yield four exposure models (in utero diet/postweaning diet: CTR/CTR n = 5; CTR/HF n = 4; HF/CTR n = 4; and HF/HF n = 5). Liver specimens were obtained at necropsy at 1 y of age. Hepatic trimethylation of lysine 4 of histone H3 is decreased (CTR/HF 0.87-fold, P = 0.038; HF/CTR 0.84-fold, P = 0.038), whereas hepatic methyltransferase activity increased by virtue of diet exposure (HF/HF 1.3-fold, P = 0.019). Using chromatin immunoprecipitation to determine Npas2 promoter occupancy, we found alterations of both repressive and permissive histone modifications specifically with postweaning HF diet exposure. We found that altered Npas2 expression corresponds with a change in the histone code within the Npas2 promoter.

  16. The Effect of Histone Hyperacetylation on Viability of Basal-Like Breast Cancer Cells MDA-MB-231

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    Aliasghar Rahimian

    2017-06-01

    Full Text Available Background The Basal-Like breast cancer, is always known for lack of expression of estrogen receptor (ER, progesterone receptor (PR and as well, absence of epidermal growth factor receptor 2 (HER2 gene amplification. Improper expression pattern of ER, PR, and Her2, makes Basal-Like breast tumors resistant to the current hormonal and anti HER2 treatments. In recent decades, several studies have been conducted to investigate the regulatory role of chemical modifications of core histones in gene expression. Their results have shown that histone acetylation is involved in regulation of cell survival. Acetylation of core histones is regulated by the epigenetic-modifying enzymes named Histone Deacetylases (HDACs. As a new approach to control the viability of breast tumor cells resistant to the hormonal and anti-HER2 treatments, we have targeted the HDACs. Using Trichostatin A (TSA as a known HDACs inhibitor, we have tried to hyperacetylate the core histones of MDA-MB-231 cells as an in vitro model of Basal-Like breast tumors. Then we have investigated the effect of histone hyperacetylation on viability of MDA-MB-231 cells. Methods MDA-MB-231 cells were cultured in RPMI 1640 medium containing 10% fetal bovine serum (FBS and were incubated at 37°C, in a humidified incubator with 5% CO2 atmosphere. Then cells were treated with different concentrations of TSA including: 50, 100, 200, 400, 800 and 1000 nM or control (1% DMSO. After 24 and 48 hours, viability of cells was evaluated by MTT assay. Results After 24 and 48h exposure to different concentrations of TSA, MDA-MB-231 cells showed a maximum tolerable dose. At higher concentrations, TSA decreased the percentage of cell viability through a time-dose dependent manner. IC50 value for 48h treatment was 600 nM. Conclusions Our results indicate that HDACs inhibition and subsequently hyperacetylation of histones, leads to cytotoxic effects on breast tumor cells resistant to the current treatments. Following

  17. Histone deacetylase 3 (HDAC 3) as emerging drug target in NF-kappa B-mediated inflammation

    NARCIS (Netherlands)

    Leus, Niek G. J.; Zwinderman, Martijn R. H.; Dekker, Frank J.

    Activation of inflammatory gene expression is regulated, among other factors, by post-translational modifications of histone proteins. The most investigated type of histone modifications is lysine acetylations. Histone deacetylases (HDACs) remove acetylations from lysines, thereby influencing

  18. Identifying the Combinatorial Effects of Histone Modifications by Association Rule Mining in Yeast

    Science.gov (United States)

    Wang, Jiang; Dai, Xianhua; Xiang, Qian; Deng, Yangyang; Feng, Jihua; Dai, Zhiming; He, Caisheng

    2010-01-01

    Eukaryotic genomes are packaged into chromatin by histone proteins whose chemical modification can profoundly influence gene expression. The histone modifications often act in combinations, which exert different effects on gene expression. Although a number of experimental techniques and data analysis methods have been developed to study histone modifications, it is still very difficult to identify the relationships among histone modifications on a genome-wide scale. We proposed a method to identify the combinatorial effects of histone modifications by association rule mining. The method first identified Functional Modification Transactions (FMTs) and then employed association rule mining algorithm and statistics methods to identify histone modification patterns. We applied the proposed methodology to Pokholok et al’s data with eight sets of histone modifications and Kurdistani et al’s data with eleven histone acetylation sites. Our method succeeds in revealing two different global views of histone modification landscapes on two datasets and identifying a number of modification patterns some of which are supported by previous studies. We concentrate on combinatorial effects of histone modifications which significantly affect gene expression. Our method succeeds in identifying known interactions among histone modifications and uncovering many previously unknown patterns. After in-depth analysis of possible mechanism by which histone modification patterns can alter transcriptional states, we infer three possible modification pattern reading mechanism (‘redundant’, ‘trivial’, ‘dominative’). Our results demonstrate several histone modification patterns which show significant correspondence between yeast and human cells. PMID:21037963

  19. Quantitative Histone Mass Spectrometry Identifies Elevated Histone H3 Lysine 27 (Lys27) Trimethylation in Melanoma.

    Science.gov (United States)

    Sengupta, Deepanwita; Byrum, Stephanie D; Avaritt, Nathan L; Davis, Lauren; Shields, Bradley; Mahmoud, Fade; Reynolds, Matthew; Orr, Lisa M; Mackintosh, Samuel G; Shalin, Sara C; Tackett, Alan J

    2016-03-01

    Normal cell growth is characterized by a regulated epigenetic program that drives cellular activities such as gene transcription, DNA replication, and DNA damage repair. Perturbation of this epigenetic program can lead to events such as mis-regulation of gene transcription and diseases such as cancer. To begin to understand the epigenetic program correlated to the development of melanoma, we performed a novel quantitative mass spectrometric analysis of histone post-translational modifications mis-regulated in melanoma cell culture as well as patient tumors. Aggressive melanoma cell lines as well as metastatic melanoma were found to have elevated histone H3 Lys(27) trimethylation (H3K27me3) accompanied by overexpressed methyltransferase EZH2 that adds the specific modification. The altered epigenetic program that led to elevated H3K27me3 in melanoma cell culture was found to directly silence transcription of the tumor suppressor genes RUNX3 and E-cadherin. The EZH2-mediated silencing of RUNX3 and E-cadherin transcription was also validated in advanced stage human melanoma tissues. This is the first study focusing on the detailed epigenetic mechanisms leading to EZH2-mediated silencing of RUNX3 and E-cadherin tumor suppressors in melanoma. This study underscores the utility of using high resolution mass spectrometry to identify mis-regulated epigenetic programs in diseases such as cancer, which could ultimately lead to the identification of biological markers for diagnostic and prognostic applications. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. Structure and activity of enzymes that remove histone modifications.

    Science.gov (United States)

    Holbert, Marc A; Marmorstein, Ronen

    2005-12-01

    The post-translational modification of histones plays an important role in chromatin regulation, a process that insures the fidelity of gene expression and other DNA transactions. Equally important as the enzymes that generate these modifications are the enzymes that remove them. Recent studies have identified some of the enzymes that remove histone modifications and have characterized their activities. In addition, structural and biochemical studies of these enzymes have focused on the histone lysine deacetylases HDAC8 and sirtuins, and on the arginine and lysine demethylases PAD and BHC110/LSD1, respectively. These new findings may be used as a context to present new information that contributes to our understanding of chromatin regulation, and to pose remaining questions pertaining to the activities of these enzymes and the roles they play in chromatin regulation.

  1. Sliding and peeling of histone during chromatin remodelling

    CERN Document Server

    Garai, Ashok; Chowdhury, Debashish

    2011-01-01

    ATP-dependent chromatin remodeling enzymes (CRE) are bio-molecular motors in eukaryotic cells. These are driven by a chemical fuel, namely, adenosine triphosphate (ATP). CREs actively participate in many cellular processes that require accessibility of specific stretches of DNA which are packaged as chromatin. The basic unit of chromatin is a nucleosome where 146 bp $\\sim$ 50 nm of a double stranded DNA (dsDNA) is wrapped around a spool formed by histone proteins. We investigate the mechanism of peeling of the histone spool, and its complete detachment, from the dsDNA by a CRE. Our two-state model of a CRE captures effectively two distinct chemical (or conformational) states in the mechano-chemical cycle of each ATP-dependent CRE. We calculate the mean times for histone detachment. Our predictions on the ATP-dependence of the measurable quantities can be tested by carrying out {\\it in-vitro} experiments.

  2. The Histone Modification Code in the Pathogenesis of Autoimmune Diseases.

    Science.gov (United States)

    Araki, Yasuto; Mimura, Toshihide

    2017-01-01

    Autoimmune diseases are chronic inflammatory disorders caused by a loss of self-tolerance, which is characterized by the appearance of autoantibodies and/or autoreactive lymphocytes and the impaired suppressive function of regulatory T cells. The pathogenesis of autoimmune diseases is extremely complex and remains largely unknown. Recent advances indicate that environmental factors trigger autoimmune diseases in genetically predisposed individuals. In addition, accumulating results have indicated a potential role of epigenetic mechanisms, such as histone modifications, in the development of autoimmune diseases. Histone modifications regulate the chromatin states and gene transcription without any change in the DNA sequence, possibly resulting in phenotype alteration in several different cell types. In this paper, we discuss the significant roles of histone modifications involved in the pathogenesis of autoimmune diseases, including rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, primary biliary cirrhosis, and type 1 diabetes.

  3. The Histone Modification Code in the Pathogenesis of Autoimmune Diseases

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    Yasuto Araki

    2017-01-01

    Full Text Available Autoimmune diseases are chronic inflammatory disorders caused by a loss of self-tolerance, which is characterized by the appearance of autoantibodies and/or autoreactive lymphocytes and the impaired suppressive function of regulatory T cells. The pathogenesis of autoimmune diseases is extremely complex and remains largely unknown. Recent advances indicate that environmental factors trigger autoimmune diseases in genetically predisposed individuals. In addition, accumulating results have indicated a potential role of epigenetic mechanisms, such as histone modifications, in the development of autoimmune diseases. Histone modifications regulate the chromatin states and gene transcription without any change in the DNA sequence, possibly resulting in phenotype alteration in several different cell types. In this paper, we discuss the significant roles of histone modifications involved in the pathogenesis of autoimmune diseases, including rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, primary biliary cirrhosis, and type 1 diabetes.

  4. The role of histone methyltransferase EZH2 in myelodysplastic syndromes.

    Science.gov (United States)

    Xu, Feng; Li, Xiao

    2012-04-01

    Previous epigenetics research in myelodysplastic syndromes (MDS) mainly focused on the DNA methylation of tumor suppressor genes. Recent studies reported that around 6% of MDS patients have several EZH2 mutations including missense, frameshift and truncated mutations. Histone methyltransferase EZH2 plays a critical role in epigenetic regulation as a bridge between histone methylation/deacetylation and DNA methylation. EZH2 is frequently overexpressed and considered to be an oncogene in cancers; nevertheless, EZH2 is considered as a candidate tumor suppressor gene in MDS due to EZH2 mutations associated with poor survival. Many questions still need further discussion. Moreover, 3-deazaneplanocin can reduce EZH2 levels and H3K27 trimethylation, and synergistic effects are seen in combination with DNA demethylation agents or histone deacetylation inhibitors. All of the above give us more chances to improve epigenetic therapy in MDS. Therefore, the molecular mechanisms of EZH2 in tumorigenesis and the role of EZH2 in MDS are studied.

  5. The Role of Histone Protein Modifications and Mutations in Histone Modifiers in Pediatric B-Cell Progenitor Acute Lymphoblastic Leukemia

    Science.gov (United States)

    Janczar, Szymon; Janczar, Karolina; Pastorczak, Agata; Harb, Hani; Paige, Adam J. W.; Zalewska-Szewczyk, Beata; Danilewicz, Marian; Mlynarski, Wojciech

    2017-01-01

    While cancer has been long recognized as a disease of the genome, the importance of epigenetic mechanisms in neoplasia was acknowledged more recently. The most active epigenetic marks are DNA methylation and histone protein modifications and they are involved in basic biological phenomena in every cell. Their role in tumorigenesis is stressed by recent unbiased large-scale studies providing evidence that several epigenetic modifiers are recurrently mutated or frequently dysregulated in multiple cancers. The interest in epigenetic marks is especially due to the fact that they are potentially reversible and thus druggable. In B-cell progenitor acute lymphoblastic leukemia (BCP-ALL) there is a relative paucity of reports on the role of histone protein modifications (acetylation, methylation, phosphorylation) as compared to acute myeloid leukemia, T-cell ALL, or other hematologic cancers, and in this setting chromatin modifications are relatively less well studied and reviewed than DNA methylation. In this paper, we discuss the biomarker associations and evidence for a driver role of dysregulated global and loci-specific histone marks, as well as mutations in epigenetic modifiers in BCP-ALL. Examples of chromatin modifiers recurrently mutated/disrupted in BCP-ALL and associated with disease outcomes include MLL1, CREBBP, NSD2, and SETD2. Altered histone marks and histone modifiers and readers may play a particular role in disease chemoresistance and relapse. We also suggest that epigenetic regulation of B-cell differentiation may have parallel roles in leukemogenesis. PMID:28054944

  6. Engineering Recombinant Protein Sensors for Quantifying Histone Acetylation.

    Science.gov (United States)

    Sanchez, Oscar F; Mendonca, Agnes; Carneiro, Ana D; Yuan, Chongli

    2017-03-24

    H3K14ac (acetylation of lysine 14 of histone H3) is one of the most important epigentic modifications. Aberrant changes in H3K14ac have been associated with various diseases, including cancers and neurological disorders. Tools that enable detection and quantification of H3K14ac levels in cell extracts and in situ are thus of critical importance to reveal its role in various biological processes. Current detection techniques of specific histone modifications, however, are constrained by tedious sample pretreatments, lack of quantitative accuracy, and reliance on high quality antibodies. To address this issue, we engineered recombinant sensors that are suitable for probing histone acetylation levels using various biological samples. The protein sensor contains recongition domain(s) with sequences derived from the bromodomain of human polybromo-1 (PB1), a natural H3K14ac reader domain. Various sensor designs were tested using nuclear extracts and live cells. The sensor containing dimeric repeats of bromodomain was found most effective in quantifying H3K14ac level in both in vitro and in situ assays. The sensor has a linear detection range of 0.5-50 nM when mixed with nuclear extracts. The sensor colocalizes with H3K14ac antibodies in situ when transfected into human embryonic kidney 293T (HEK293T) cells and is thus capable of providing spatial details of histone modification within the nucleus. Corrected nuclear fluorescence intensity was used to quantify the modification level in situ and found to correlate well with our in vitro assays. Our sensor offers a novel tool to characterize the histone modification level using nuclear extracts and probe histone modification change in live cells.

  7. Biochemical systems approaches for the analysis of histone modification readout.

    Science.gov (United States)

    Soldi, Monica; Bremang, Michael; Bonaldi, Tiziana

    2014-08-01

    Chromatin is the macromolecular nucleoprotein complex that governs the organization of genetic material in the nucleus of eukaryotic cells. In chromatin, DNA is packed with histone proteins into nucleosomes. Core histones are prototypes of hyper-modified proteins, being decorated by a large number of site-specific reversible and irreversible post-translational modifications (PTMs), which contribute to the maintenance and modulation of chromatin plasticity, gene activation, and a variety of other biological processes and disease states. The observations of the variety, frequency and co-occurrence of histone modifications in distinct patterns at specific genomic loci have led to the idea that hPTMs can create a molecular barcode, read by effector proteins that translate it into a specific transcriptional state, or process, on the underlying DNA. However, despite the fact that this histone-code hypothesis was proposed more than 10 years ago, the molecular details of its working mechanisms are only partially characterized. In particular, two questions deserve specific investigation: how the different modifications associate and synergize into patterns and how these PTM configurations are read and translated by multi-protein complexes into a specific functional outcome on the genome. Mass spectrometry (MS) has emerged as a versatile tool to investigate chromatin biology, useful for both identifying and validating hPTMs, and to dissect the molecular determinants of histone modification readout systems. We review here the MS techniques and the proteomics methods that have been developed to address these fundamental questions in epigenetics research, emphasizing approaches based on the proteomic dissection of distinct native chromatin regions, with a critical evaluation of their present challenges and future potential. This article is part of a Special Issue entitled: Molecular mechanisms of histone modification function. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Identification and Characterization of Histone Deacetylases in Tomato (Solanum lycopersicum

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    Linmao eZhao

    2015-01-01

    Full Text Available Histone acetylation and deacetylation at the N-terminus of histone tails play crucial roles in the regulation of eukaryotic gene activity. Histone acetylation and deacetylation are catalyzed by histone acetyltransferases and histone deacetylases (HDACs, respectively. A growing number of studies have demonstrated the importance of histone deacetylation/acetylation on genome stability, transcriptional regulation, development and response to stress in Arabidopsis. However, the biological functions of HDACs in tomato have not been investigated previously. Fifteen HDACs identified from tomato (Solanum Lycopersicum can be grouped into RPD3/HDA1, SIR2 and HD2 families based on phylogenetic analysis. Meanwhile, ten members of the RPD3/HDA1 family can be further subdivided into four groups, namely Class I, Class II, Class III and Class IV. High similarities of protein sequences and conserved domains were identified among SlHDACs and their homologs in Arabidopsis. Most SlHDACs were expressed in all tissues examined with different transcript abundance. Transient expression in Arabidopsis protoplasts showed that SlHDA8, SlHDA1, SlHDA5, SlSRT1 and members of the HD2 family were localized to the nucleus, whereas SlHDA3 and SlHDA4 were localized in both the cytoplasm and nucleus. The difference in the expression patterns and subcellular localization of SlHDACs suggest that they may play distinct functions in tomato. Furthermore, we found that three members of the RPD3/HDA1 family, SlHDA1, SIHDA3 and SlHDA4, interacted with TAG1 (TOMATO AGAMOUS1 and TM29 (TOMATO MADS BOX29, two MADS-box proteins associated with tomato reproductive development,indicating that these HDACs may be involved in gene regulation in reproductive development.

  9. DNA methylation pathways and their crosstalk with histone methylation

    Science.gov (United States)

    Du, Jiamu; Johnson, Lianna M.; Jacobsen, Steven E.; Patel, Dinshaw J.

    2015-01-01

    Methylation of DNA and of histone 3 at Lys 9 (H3K9) are highly correlated with gene silencing in eukaryotes from fungi to humans. Both of these epigenetic marks need to be established at specific regions of the genome and then maintained at these sites through cell division. Protein structural domains that specifically recognize methylated DNA and methylated histones are key for targeting enzymes that catalyse these marks to appropriate genome sites. Genetic, genomic, structural and biochemical data reveal connections between these two epigenetic marks, and these domains mediate much of the crosstalk. PMID:26296162

  10. Mechanisms of transcriptional repression by histone lysine methylation

    DEFF Research Database (Denmark)

    Hublitz, Philip; Albert, Mareike; Peters, Antoine H F M

    2009-01-01

    . In this report, we review the recent literature to deduce mechanisms underlying Polycomb and H3K9 methylation mediated repression, and describe the functional interplay with activating H3K4 methylation. We summarize recent data that indicate a close relationship between GC density of promoter sequences......, transcription factor binding and the antagonizing activities of distinct epigenetic regulators such as histone methyltransferases (HMTs) and histone demethylases (HDMs). Subsequently, we compare chromatin signatures associated with different types of transcriptional outcomes from stable repression to highly...... dynamic regulated genes, strongly suggesting that the interplay of different epigenetic pathways is essential in defining specific types of heritable chromatin and associated transcriptional states....

  11. Two distinct modes for propagation of histone PTMs across the cell cycle

    DEFF Research Database (Denmark)

    Alabert, Constance; Barth, Teresa K; Reverón-Gómez, Nazaret

    2015-01-01

    to track histone modifications and histone variants during DNA replication and across the cell cycle. We show that post-translational modifications (PTMs) are transmitted with parental histones to newly replicated DNA. Di- and trimethylation marks are diluted twofold upon DNA replication, as a consequence...... of new histone deposition. Importantly, within one cell cycle, all PTMs are restored. In general, new histones are modified to mirror the parental histones. However, H3K9 trimethylation (H3K9me3) and H3K27me3 are propagated by continuous modification of parental and new histones because the establishment...... of these marks extends over several cell generations. Together, our results reveal how histone marks propagate and demonstrate that chromatin states oscillate within the cell cycle....

  12. Substrate Specificity Profiling of Histone-Modifying Enzymes by Peptide Microarray.

    Science.gov (United States)

    Cornett, E M; Dickson, B M; Vaughan, R M; Krishnan, S; Trievel, R C; Strahl, B D; Rothbart, S B

    2016-01-01

    The dynamic addition and removal of covalent posttranslational modifications (PTMs) on histone proteins serves as a major mechanism regulating chromatin-templated biological processes in eukaryotic genomes. Histone PTMs and their combinations function by directly altering the physical structure of chromatin and as rheostats for effector protein interactions. In this chapter, we detail microarray-based methods for analyzing the substrate specificity of lysine methyltransferase and demethylase enzymes on immobilized synthetic histone peptides. Consistent with the "histone code" hypothesis, we reveal a strong influence of adjacent and, surprisingly, distant histone PTMs on the ability of histone-modifying enzymes to methylate or demethylate their substrates. This platform will greatly facilitate future investigations into histone substrate specificity and mechanisms of PTM signaling that regulate the catalytic properties of histone-modifying enzymes. © 2016 Elsevier Inc. All rights reserved.

  13. Balancing of Histone H3K4 Methylation States by the Kdm5c/SMCX Histone Demethylase Modulates Promoter and Enhancer Function

    Directory of Open Access Journals (Sweden)

    Nikolay S. Outchkourov

    2013-04-01

    Full Text Available The functional organization of eukaryotic genomes correlates with specific patterns of histone methylations. Regulatory regions in genomes such as enhancers and promoters differ in their extent of methylation of histone H3 at lysine-4 (H3K4, but it is largely unknown how the different methylation states are specified and controlled. Here, we show that the Kdm5c/Jarid1c/SMCX member of the Kdm5 family of H3K4 demethylases can be recruited to both enhancer and promoter elements in mouse embryonic stem cells and in neuronal progenitor cells. Knockdown of Kdm5c deregulates transcription via local increases in H3K4me3. Our data indicate that by restricting H3K4me3 modification at core promoters, Kdm5c dampens transcription, but at enhancers Kdm5c stimulates their activity. Remarkably, an impaired enhancer function activates the intrinsic promoter activity of Kdm5c-bound distal elements. Our results demonstrate that the Kdm5c demethylase plays a crucial and dynamic role in the functional discrimination between enhancers and core promoters.

  14. Lipids Reprogram Metabolism to Become a Major Carbon Source for Histone Acetylation

    DEFF Research Database (Denmark)

    McDonnell, Eoin; Crown, Scott B; Fox, Douglas B

    2016-01-01

    . By repressing both glucose and glutamine metabolism, fatty acid oxidation reprograms cellular metabolism, leading to increased lipid-derived acetyl-CoA. Gene expression profiling of octanoate-treated hepatocytes shows a pattern of upregulated lipid metabolic genes, demonstrating a specific transcriptional...... response to lipid. These studies expand the landscape of nutrient sensing and uncover how lipids and metabolism are integrated by epigenetic events that control gene expression.......Cells integrate nutrient sensing and metabolism to coordinate proper cellular responses to a particular nutrient source. For example, glucose drives a gene expression program characterized by activating genes involved in its metabolism, in part by increasing glucose-derived histone acetylation...

  15. Lysine acetylome profiling uncovers novel histone deacetylase substrate proteins in Arabidopsis

    DEFF Research Database (Denmark)

    Hartl, Markus; Füßl, Magdalena; Boersema, Paul J

    2017-01-01

    the proteome-wide signatures of the RPD3/HDA1 class of histone deacetylases in Arabidopsis Relative quantification of the changes in the lysine acetylation levels was determined on a proteome-wide scale after treatment of Arabidopsis leaves with deacetylase inhibitors apicidin and trichostatin A. We identified......) is the first organellar-localized RPD3/HDA1 class protein found to reside in the chloroplasts and that the majority of its protein targets have functions in photosynthesis. Finally, the analysis of HDA14 loss-of-function mutants revealed that the activation state of RuBisCO is controlled by lysine acetylation...

  16. Histone hyperacetylation and exon skipping: a calcium-mediated dynamic regulation in cardiomyocytes

    Science.gov (United States)

    Sharma, Alok; Nguyen, Hieu; Cai, Lu; Lou, Hua

    2015-01-01

    In contrast to cell type-specific pre-mRNA alternative splicing, mechanisms controlling activity-dependent alternative splicing is under-studied and not well understood. In a recent study, we conducted a comprehensive analysis of calcium-mediated mechanism that regulates alternative exon skipping in mouse cardiomyocytes. Our results reveal a strong link between histone hyperacetylation and skipping of cassette exons, and provide support to the kinetic coupling model of the epigenetic regulation of alternative splicing at the chromatin level. PMID:26325491

  17. SIRT1-dependent modulation of methylation and acetylation of histone H3 on lysine 9 (H3K9 in the zygotic pronuclei improves porcine embryo development

    Directory of Open Access Journals (Sweden)

    Katerina Adamkova

    2017-11-01

    Full Text Available Abstract Background The histone code is an established epigenetic regulator of early embryonic development in mammals. The lysine residue K9 of histone H3 (H3K9 is a prime target of SIRT1, a member of NAD+-dependent histone deacetylase family of enzymes targeting both histone and non-histone substrates. At present, little is known about SIRT1-modulation of H3K9 in zygotic pronuclei and its association with the success of preimplantation embryo development. Therefore, we evaluated the effect of SIRT1 activity on H3K9 methylation and acetylation in porcine zygotes and the significance of H3K9 modifications for early embryonic development. Results Our results show that SIRT1 activators resveratrol and BML-278 increased H3K9 methylation and suppressed H3K9 acetylation in both the paternal and maternal pronucleus. Inversely, SIRT1 inhibitors nicotinamide and sirtinol suppressed methylation and increased acetylation of pronuclear H3K9. Evaluation of early embryonic development confirmed positive effect of selective SIRT1 activation on blastocyst formation rate (5.2 ± 2.9% versus 32.9 ± 8.1% in vehicle control and BML-278 group, respectively; P ≤ 0.05. Stimulation of SIRT1 activity coincided with fluorometric signal intensity of ooplasmic ubiquitin ligase MDM2, a known substrate of SIRT1 and known limiting factor of epigenome remodeling. Conclusions We conclude that SIRT1 modulates zygotic histone code, obviously through direct deacetylation and via non-histone targets resulting in increased H3K9me3. These changes in zygotes lead to more successful pre-implantation embryonic development and, indeed, the specific SIRT1 activation due to BML-278 is beneficial for in vitro embryo production and blastocyst achievement.

  18. EPC1/TIP60-mediated histone acetylation facilitates spermiogenesis in mice

    DEFF Research Database (Denmark)

    Dong, Yixin; Isono, Kyo Ichi; Ohbo, Kazuyuki

    2017-01-01

    Global histone hyperacetylation is suggested to play a critical role for replacement of histones by transition proteins and protamines to compact the genome during spermiogenesis. However, the underlying mechanisms for hyperacetylation- mediated histone replacement remains poorly understood. Here...... spermatid development. Taking these observations together, we reveal an essential role of the NuA4 complexes for histone hyperacetylation and subsequent compaction of the spermatid genome....

  19. Quantitative analysis of histone modifications: formaldehyde is a source of pathological n(6-formyllysine that is refractory to histone deacetylases.

    Directory of Open Access Journals (Sweden)

    Bahar Edrissi

    Full Text Available Aberrant protein modifications play an important role in the pathophysiology of many human diseases, in terms of both dysfunction of physiological modifications and the formation of pathological modifications by reaction of proteins with endogenous electrophiles. Recent studies have identified a chemical homolog of lysine acetylation, N(6-formyllysine, as an abundant modification of histone and chromatin proteins, one possible source of which is the reaction of lysine with 3'-formylphosphate residues from DNA oxidation. Using a new liquid chromatography-coupled to tandem mass spectrometry method to quantify all N(6-methyl-, -acetyl- and -formyl-lysine modifications, we now report that endogenous formaldehyde is a major source of N(6-formyllysine and that this adduct is widespread among cellular proteins in all compartments. N(6-formyllysine was evenly distributed among different classes of histone proteins from human TK6 cells at 1-4 modifications per 10(4 lysines, which contrasted strongly with lysine acetylation and mono-, di-, and tri-methylation levels of 1.5-380, 5-870, 0-1400, and 0-390 per 10(4 lysines, respectively. While isotope labeling studies revealed that lysine demethylation is not a source of N(6-formyllysine in histones, formaldehyde exposure was observed to cause a dose-dependent increase in N(6-formyllysine, with use of [(13C,(2H2]-formaldehyde revealing unchanged levels of adducts derived from endogenous sources. Inhibitors of class I and class II histone deacetylases did not affect the levels of N(6-formyllysine in TK6 cells, and the class III histone deacetylase, SIRT1, had minimal activity (<10% with a peptide substrate containing the formyl adduct. These data suggest that N(6-formyllysine is refractory to removal by histone deacetylases, which supports the idea that this abundant protein modification could interfere with normal regulation of gene expression if it arises at conserved sites of physiological protein secondary

  20. Esperanto for histones: CENP-A, not CenH3, is the centromeric histone H3 variant.

    Science.gov (United States)

    Earnshaw, W C; Allshire, R C; Black, B E; Bloom, K; Brinkley, B R; Brown, W; Cheeseman, I M; Choo, K H A; Copenhaver, G P; Deluca, J G; Desai, A; Diekmann, S; Erhardt, S; Fitzgerald-Hayes, M; Foltz, D; Fukagawa, T; Gassmann, R; Gerlich, D W; Glover, D M; Gorbsky, G J; Harrison, S C; Heun, P; Hirota, T; Jansen, L E T; Karpen, G; Kops, G J P L; Lampson, M A; Lens, S M; Losada, A; Luger, K; Maiato, H; Maddox, P S; Margolis, R L; Masumoto, H; McAinsh, A D; Mellone, B G; Meraldi, P; Musacchio, A; Oegema, K; O'Neill, R J; Salmon, E D; Scott, K C; Straight, A F; Stukenberg, P T; Sullivan, B A; Sullivan, K F; Sunkel, C E; Swedlow, J R; Walczak, C E; Warburton, P E; Westermann, S; Willard, H F; Wordeman, L; Yanagida, M; Yen, T J; Yoda, K; Cleveland, D W

    2013-04-01

    The first centromeric protein identified in any species was CENP-A, a divergent member of the histone H3 family that was recognised by autoantibodies from patients with scleroderma-spectrum disease. It has recently been suggested to rename this protein CenH3. Here, we argue that the original name should be maintained both because it is the basis of a long established nomenclature for centromere proteins and because it avoids confusion due to the presence of canonical histone H3 at centromeres.

  1. Patterns and Mechanisms of Ancestral Histone Protein Inheritance in Budding Yeast

    Science.gov (United States)

    van Welsem, Tibor; Friedman, Nir; Rando, Oliver J.; van Leeuwen, Fred

    2011-01-01

    Replicating chromatin involves disruption of histone-DNA contacts and subsequent reassembly of maternal histones on the new daughter genomes. In bulk, maternal histones are randomly segregated to the two daughters, but little is known about the fine details of this process: do maternal histones re-assemble at preferred locations or close to their original loci? Here, we use a recently developed method for swapping epitope tags to measure the disposition of ancestral histone H3 across the yeast genome over six generations. We find that ancestral H3 is preferentially retained at the 5′ ends of most genes, with strongest retention at long, poorly transcribed genes. We recapitulate these observations with a quantitative model in which the majority of maternal histones are reincorporated within 400 bp of their pre-replication locus during replication, with replication-independent replacement and transcription-related retrograde nucleosome movement shaping the resulting distributions of ancestral histones. We find a key role for Topoisomerase I in retrograde histone movement during transcription, and we find that loss of Chromatin Assembly Factor-1 affects replication-independent turnover. Together, these results show that specific loci are enriched for histone proteins first synthesized several generations beforehand, and that maternal histones re-associate close to their original locations on daughter genomes after replication. Our findings further suggest that accumulation of ancestral histones could play a role in shaping histone modification patterns. PMID:21666805

  2. Characterization of lysine 56 of histone H3 as an acetylation site in Saccharomyces cerevisiae.

    NARCIS (Netherlands)

    Ozdemir, A.; Spicuglia, S.; Lasonder, E.; Vermeulen, M.; Campsteijn, C.G.; Stunnenberg, H.G.; Logie, C.

    2005-01-01

    Post-translational histone modifications abound and regulate multiple nuclear processes. Most modifications are targeted to the amino-terminal domains of histones. Here we report the identification and characterization of acetylation of lysine 56 within the core domain of histone H3. In the crystal

  3. Autoantibodies against citrullinated histone H3 in rheumatoid arthritis and periodontitis patients

    NARCIS (Netherlands)

    Janssen, Koen M. J.; de Smit, Menke J.; Withaar, Coenraad; Brouwer, Elisabeth; van Winkelhoff, Arie J.; Vissink, Arjan; Westra, Johanna

    Aim: To determine the presence of citrullinated histones in inflamed periodontal tissue and to determine the presence of anti-citrullinated histone autoantibodies in sera from patients with rheumatoid arthritis (RA) and periodontitis (PD) patients. Methods: The presence of citrullinated histone H3,

  4. Histone deacetylase inhibitors induced differentiation and accelerated mineralization of pulp-derived cells.

    LENUS (Irish Health Repository)

    Duncan, Henry F

    2012-03-01

    Histone deacetylase inhibitors (HDACis) alter the homeostatic balance between 2 groups of cellular enzymes, histone deacetylases (HDACs) and histone acetyltransferases (HATs), increasing transcription and influencing cell behavior. This study investigated the potential of 2 HDACis, valproic acid (VPA) and trichostatin A (TSA), to promote reparative processes in pulp cells as assayed by viability, cell cycle, and mineralization analyses.

  5. Histone H3 Lysine Methylation in Cognition and Intellectual Disability Disorders

    Science.gov (United States)

    Parkel, Sven; Lopez-Atalaya, Jose P.; Barco, Angel

    2013-01-01

    Recent research indicates that epigenetic mechanisms and, in particular, the post-translational modification (PTM) of histones may contribute to memory encoding and storage. Among the dozens of possible histone PTMs, the methylation/demethylation of lysines in the N-terminal tail of histone H3 exhibits particularly strong links with cognitive…

  6. Dual modified antiphospho (Ser10)-acetyl (Lys14)-histone H3 ...

    Indian Academy of Sciences (India)

    SANTOSH KUMAR SHARMA

    histone may serve as an additional cytogenetic landmark to identify pericentromeric chromatin during mitosis in plants. The plausible role of histone cross talk and future perspectives of combinatorial histone modification marks in plant cytogenetics with special reference to chromatin dynamics have been discussed.

  7. Characterization of histone H3K27 modifications in the {beta}-globin locus

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yea Woon [Department of Molecular Biology, College of Natural Sciences, Pusan National University, Pusan 609-735 (Korea, Republic of); Kim, AeRi, E-mail: kimaeri@pusan.ac.kr [Department of Molecular Biology, College of Natural Sciences, Pusan National University, Pusan 609-735 (Korea, Republic of)

    2011-02-11

    Research highlights: {yields} The {beta}-globin locus control region is hyperacetylated and monomethylated at histone H3K27. {yields} Highly transcribed globin genes are marked by H3K27ac, but H3K27me2 is remarkable at silent globin genes in erythroid K562 cells. {yields} Association of PRC2 subunits is comparable with H3K27me3 pattern. {yields} Modifications of histone H3K27 are established in an enhancer-dependent manner. -- Abstract: Histone H3K27 is acetylated or methylated in the environment of nuclear chromatin. Here, to characterize the modification pattern of H3K27 in locus control region (LCR) and to understand the correlation of various H3K27 modifications with transcriptional activity of genes, we analyzed the human {beta}-globin locus using the ChIP assay. The LCR of the human {beta}-globin locus was enriched by H3K27ac and H3K27me1 in erythroid K562 cells. The highly transcribed globin genes were hyperacetylated at H3K27, but the repressed globin genes were highly dimethylated at this lysine in these cells. However, in non-erythroid 293FT cells, the {beta}-globin locus was marked by a high level of H3K27me3. EZH2 and SUZ12, subunits of polycomb repressive complex 2, were comparably detected with the H3K27me3 pattern in K562 and 293FT cells. In addition, H3K27ac, H3K27me1 and H3K27me3 were established in an enhancer-dependent manner in a model minichromosomal locus containing an enhancer and its target gene. Taken together, these results show that H3K27 modifications have distinctive correlations with the chromatin state or transcription level of genes and are influenced by an enhancer.

  8. Leuconostoc citreum HJ-P4 (KACC 91035) regulates immunoglobulin E in an ovalbumin-induced allergy model and induces interleukin-12 through nuclear factor-kappa B and p38/c-Jun N-terminal kinases signaling in macrophages.

    Science.gov (United States)

    Kang, Hee; Oh, Yoo-Joung; Ahn, Kyoo-Seok; Eom, Hyun-Ju; Han, NamSoo; Kim, Yoon-Bum; Sohn, Nak-Won

    2009-06-01

    Leuconostoc citreum (L. citreum) HJ-P4 (KACC 91035) is one of the major predominant species in kimchi fermentation in Korea. The purpose of the present study was to test the immunomodulatory capacity of L. citreum to modulate the IgE-mediated allergic response and to examine the involvement of NF-kappaB and MAPK in IL-12 production in macrophages. Balb/c mice were sensitized with OVA/alum and oral administration of L. citreum to the mice began before or after the OVA sensitization. Protein and mRNA expression of Th1 cytokines in splenocytes by L. citreum in vitro was measured. The role of NF-kappaB and MAPK such as p38, ERK1/2 and JNK in L. citreum-induced IL-12 was investigated in peritoneal macrophages and RAW264.7 cell lines. L. citreum inhibited the serum levels of total IgE, IgG1 and IgG2a altogether and increased OVA-specific IFN-gamma production in splenocytes from pre- and post-sensitized animals. However, the downregulation of IL-4 and IL-5 production was observed only in the pre-sensitization group. The ability of L. citreum to stimulate IFN-gamma was dependent on its induction of IL-12. NF-kappaB, p38 and JNK were mainly involved in L. citreum-induced IL-12 production. In conclusion, the current study demonstrated that L. citreum is able to regulate serum IgE generation at the induction and effector phases of allergic response through overall control over antibody production and that its involvement of IL-12 production was mediated through NF-kappaB and p38/JNK. Taken together, the use of L. citreum can be useful in preventing the development and progression of IgE production.

  9. Mechanistic stochastic model of histone modification pattern formation

    NARCIS (Netherlands)

    Anink-Groenen, L.C.M.; Maarleveld, T.R.; Verschure, P.J.; Bruggeman, F.J.

    2014-01-01

    BACKGROUND: The activity of a single gene is influenced by the composition of the chromatin in which it is embedded. Nucleosome turnover, conformational dynamics, and covalent histone modifications each induce changes in the structure of chromatin and its affinity for regulatory proteins. The

  10. Ontogenetic Survey of Histone Modifications in an Annelid

    Directory of Open Access Journals (Sweden)

    Glenys Gibson

    2012-01-01

    Full Text Available Histone modifications are widely recognized for their fundamental importance in regulating gene expression in embryonic development in a wide range of eukaryotes, but they have received relatively little attention in the development of marine invertebrates. We surveyed histone modifications throughout the development of a marine annelid, Polydora cornuta, to determine if modifications could be detected immunohistochemically and if there were characteristic changes in modifications throughout ontogeny (surveyed at representative stages from oocyte to adult. We found a common time of onset for three histone modifications in early cleavage (H3K14ac, H3K9me, and H3K4me2, some differences in the distribution of modifications among germ layers, differences in epifluorescence intensity in specific cell lineages suggesting that hyperacetylation (H3K14ac and hypermethylation (H3K9me occur during differentiation, and an overall decrease in the distribution of modifications from larvae to adults. Although preliminary, these results suggest that histone modifications are involved in activating early development and differentiation in a marine invertebrate.

  11. Distribution pattern of histone H3 phosphorylation at serine 10 ...

    Indian Academy of Sciences (India)

    2013-08-06

    Aug 6, 2013 ... in chromosome distribution of H3S10ph when mitosis and meiosis were compared. ... [Paula C. M. P., Techio V. H., Sobrinho F. S. and Freitas A. S. 2013 Distribution pattern of histone H3 phosphorylation at serine 10 during mitosis and meiosis in ... RDWebster], since current knowledge about specific roles ...

  12. Differential patterns of histone acetylation in inflammatory bowel diseases

    Directory of Open Access Journals (Sweden)

    Adcock Ian M

    2011-01-01

    Full Text Available Abstract Post-translational modifications of histones, particularly acetylation, are associated with the regulation of inflammatory gene expression. We used two animal models of inflammation of the bowel and biopsy samples from patients with Crohn's disease (CD to study the expression of acetylated histones (H 3 and 4 in inflamed mucosa. Acetylation of histone H4 was significantly elevated in the inflamed mucosa in the trinitrobenzene sulfonic acid model of colitis particularly on lysine residues (K 8 and 12 in contrast to non-inflamed tissue. In addition, acetylated H4 was localised to inflamed tissue and to Peyer's patches (PP in dextran sulfate sodium (DSS-treated rat models. Within the PP, H3 acetylation was detected in the mantle zone whereas H4 acetylation was seen in both the periphery and the germinal centre. Finally, acetylation of H4 was significantly upregulated in inflamed biopsies and PP from patients with CD. Enhanced acetylation of H4K5 and K16 was seen in the PP. These results demonstrate that histone acetylation is associated with inflammation and may provide a novel therapeutic target for mucosal inflammation.

  13. Natural and Synthetic Macrocyclic Inhibitors of the Histone Deacetylase Enzymes

    DEFF Research Database (Denmark)

    Maolanon, Alex; Kristensen, Helle; Leman, Luke

    2017-01-01

    Inhibition of histone deacetylase (HDAC) enzymes has emerged as a target for development of cancer chemotherapy. Four compounds have gained approval for clinical use by the Food and Drug Administration (FDA) in the US, and several are currently in clinical trials. However, none of these compounds...

  14. Effect of histone deacetylase inhibitor, trichostatin A, on cartilage ...

    African Journals Online (AJOL)

    Purpose: To evaluate the effect of histone deacetylase (HDAC) inhibitor, trichostatin A (TCA), on cartilage regeneration in a rabbit perichondrial graft model. Methods: Perichondrial grafts (20 × 20 mm2) were derived from the ears of New Zealand rabbits and transplanted onto the paravertebral muscle of the face of each ...

  15. Properly reading the histone code by MS-based proteomics.

    Science.gov (United States)

    Sidoli, Simone; Garcia, Benjamin A

    2015-09-01

    Histone proteins are essential elements for DNA packaging. Their PTMs contribute in modeling chromatin structure and recruiting enzymes involved in gene regulation, DNA repair, and chromosome condensation. This fundamental aspect, together with the fact that histone PTMs can be epigenetically inherited through cell generations, enlightens their importance in chromatin biology, and the consequent necessity of having biochemical techniques for their characterization. Nanoflow LC coupled to MS (nanoLC-MS) is the strategy of choice for protein PTM accurate quantification. However, histones require adjustments to the digestion protocol such as lysine derivatization to obtain suitable peptides for the analysis. nanoLC-MS has numerous advantages, spanning from high confidence identification to possibility of high throughput analyses, but the peculiarity of the histone preparation protocol requires continuous monitoring with the most modern available technologies to question its reliability. The work of Meert et al. (Proteomics 2015, 15, 2966-2971) establishes which protocols lead to either incomplete derivatization or derivatization of undesired amino acid residues using a combination of high resolution MS and bioinformatics tools for the alignment and the characterization of nanoLC-MS runs. As well, they identify a number of side reactions that could be potentially misinterpreted as biological PTMs. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Experimental Approaches Toward Histone Acetyltransferase Inhibitors as Therapeutics

    NARCIS (Netherlands)

    Dekker, Frank; Tollefsbol, Trygve

    2016-01-01

    This chapter comprises the most recent developments with respect to the role of human histone acetyltransferases (HATs) in diseases and the potential therapeutic applications of HAT inhibitors. HATs form a diverse group of mainly nuclear enzymes that play an important role in the acetylation of

  17. resistance-induced expression and histone modifications of WRKY ...

    Indian Academy of Sciences (India)

    FLD codes for a homologue of human-lysine-specific histone demethylase. Here we show that FLD function is required for priming (SAR induced elevated expression during challenge inoculation) of WRKY29 and WRKY6 genes. FLD also differentially influences basal and SAR-induced expression of WRKY38, WRKY65 ...

  18. Innovative Strategies for Selective Inhibition of Histone Deacetylases

    DEFF Research Database (Denmark)

    Maolanon, Alex Ramalak; Madsen, Andreas Stahl; Olsen, Christian Adam

    2016-01-01

    Histone deacetylases (HDAC) are a family of closely related enzymes involved in epigenetic and posttranscriptional regulation of numerous genes and proteins. Their deregulation is associated with a number of diseases, and a handful of HDAC inhibitors have been approved for cancer treatment. None ...

  19. resistance-induced expression and histone modifications of WRKY ...

    Indian Academy of Sciences (India)

    2014-01-27

    Jan 27, 2014 ... Ross AF 1961 Systemic acquired resistance induced by localized virus infections in plants. Virology 14 340–358. Saleh A, Alvarez-Venegas R and Avramova Z 2008 An efficient chro- matin immunoprecipitation (ChIP) protocol for studying histone mod- ifications in Arabidopsis plants. Nat. Protocols 3 1018– ...

  20. Undetectable histone O-GlcNAcylation in mammalian cells

    Science.gov (United States)

    Gagnon, Jessica; Daou, Salima; Zamorano, Natalia; Iannantuono, Nicholas VG; Hammond-Martel, Ian; Mashtalir, Nazar; Bonneil, Eric; Wurtele, Hugo; Thibault, Pierre; Affar, El Bachir

    2015-01-01

    O-GlcNAcylation is a posttranslational modification catalyzed by the O-Linked N-acetylglucosamine (O-GlcNAc) transferase (OGT) and reversed by O-GlcNAcase (OGA). Numerous transcriptional regulators, including chromatin modifying enzymes, transcription factors, and co-factors, are targeted by O-GlcNAcylation, indicating that this modification is central for chromatin-associated processes. Recently, OGT-mediated O-GlcNAcylation was reported to be a novel histone modification, suggesting a potential role in directly coordinating chromatin structure and function. In contrast, using multiple biochemical approaches, we report here that histone O-GlcNAcylation is undetectable in mammalian cells. Conversely, O-GlcNAcylation of the transcription regulators Host Cell Factor-1 (HCF-1) and Ten-Eleven Translocation protein 2 (TET2) could be readily observed. Our study raises questions on the occurrence and abundance of O-GlcNAcylation as a histone modification in mammalian cells and reveals technical complications regarding the detection of genuine protein O-GlcNAcylation. Therefore, the identification of the specific contexts in which histone O-GlcNAcylation might occur is still to be established. PMID:26075789

  1. Post-Translational Modifications of Histones in Human Sperm

    Czech Academy of Sciences Publication Activity Database

    Krejčí, Jana; Stixová, Lenka; Legartová, Soňa; Kozubek, Stanislav; Lochmanová, G.; Zdráhal, Z.; Sehnalová, Petra; Dabravolski, S.; Hejatko, J.; Bártová, Eva

    2015-01-01

    Roč. 116, č. 10 (2015), s. 2195-2209 ISSN 0730-2312 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081707 Keywords : HUMAN SPERM * HISTONES * PROTAMINE P2 Subject RIV: BO - Biophysics Impact factor: 3.446, year: 2015

  2. Roles of the EZH2 histone methyltransferase in cancer epigenetics.

    Science.gov (United States)

    Simon, Jeffrey A; Lange, Carol A

    2008-12-01

    EZH2 is the catalytic subunit of Polycomb repressive complex 2 (PRC2), which is a highly conserved histone methyltransferase that targets lysine-27 of histone H3. This methylated H3-K27 chromatin mark is commonly associated with silencing of differentiation genes in organisms ranging from plants to flies to humans. Studies on human tumors show that EZH2 is frequently over-expressed in a wide variety of cancerous tissue types, including prostate and breast. Although the mechanistic contributions of EZH2 to cancer progression are not yet determined, functional links between EZH2-mediated histone methylation and DNA methylation suggest partnership with the gene silencing machinery implicated in tumor suppressor loss. Here we review the basic molecular biology of EZH2 and the findings that implicate EZH2 in different cancers. We also discuss EZH2 connections to other silencing enzymes, such as DNA methyltransferases and histone deacetylases, and we consider progress on deciphering mechanistic consequences of EZH2 overabundance and its potential roles in tumorigenesis. Finally, we review recent findings that link EZH2 roles in stem cells and cancer, and we consider prospects for integrating EZH2 blockade into strategies for developing epigenetic therapies.

  3. Relationship of histone acetylation to DNA topology and transcription.

    Science.gov (United States)

    Krajewski, W A; Luchnik, A N

    1991-12-01

    An autonomously replicating plasmid constructed from bovine papiloma virus (BPV) and pBR322 was stably maintained as a nuclear episome in a mouse cell culture. Addition to a cell culture of sodium butyrate (5 mM) induced an increase in plasmid DNA supercoiling of 3-5 turns, an increase in acetylation of cellular histones, and a decrease in plasmid transcription by 2- to 4-fold. After withdrawal of butyrate, DNA supercoiling began to fluctuate in a wave-like manner with an amplitude of up to 3 turns and a period of 3-4 h. These waves gradually faded by 24 h. The transcription of the plasmid and acetylation of cellular histones also oscillated with the same period. The wave-like alterations were not correlated with the cell cycle, for there was no resumption of DNA replication after butyrate withdrawal for at least 24 h. In vitro chemical acetylation of histones with acetyl adenylate also led to an increase in the superhelical density of plasmid DNA. The parallel changes in transcription, histone acetylation, and DNA supercoiling in vivo may indicate a functional innerconnection. Also, the observed in vivo variation in the level of DNA supercoiling directly indicates the possibility of its natural regulation in eukaryotic cells.

  4. Histone modification profiles characterize function-specific gene regulation.

    Science.gov (United States)

    Jung, Inkyung; Kim, Dongsup

    2012-10-07

    Chromatin modification is ubiquitous in gene regulation. Despite much effort, a systematic investigation is needed to understand whether each modification has a unique property depending on the function of its associated genes. Here, we show that consideration of function-specific histone modification profiles is important for accurate prediction of gene expression levels, and is maintained across cell types. The performance improvement is thought to originate from the association between modifications and gene expression levels for each biological function. The varying relationship between histone modifications and gene expression levels can be partly explained by considering function-specific PolII recruitment mechanisms, and is supported by more accurate predictions of PolII occupancies with function-specific modification profiles. We suggest that the function-specific binding of transcription factors and chromatin regulators may explain similar gene regulatory mechanisms, such as function-specific PolII recruitment, in each functional gene set. Our study demonstrates that each histone modification has a different characteristic according to the function of its associated genes; thus, different combinations of histone modification profiles characterize function-specific gene regulation. The current analysis is available on our web server (biodb.kaist.ac.kr/impohis). Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Rôle d'histones methyltransférases spécifiques de H3K9 dans l'équilibre prolifération et différenciation cellulaire

    OpenAIRE

    Battisti, Valentine

    2013-01-01

    In eukaryotes, gene expression partly relies on chromatin compaction degree. Chromatin status is controlled by epigenetic marks, such as histones (chromatin structural proteins) posttranslational modifications. As an example, histone H3 lysine 9 (H3K9) methylation on gene promoters is mainly associated with transcriptional repression. H3K9 is methylated by several enzymes called lysine methyltransferases (KMTs). The aim of my thesis project was to understand the role of the H3K9 KMTs, G9a, GL...

  6. Genome-wide profiling of histone modifications (H3K9me2 and H4K12ac) and gene expression in rust (uromyces appendiculatus) inoculated common bean (Phaseolus vulgaris L)

    OpenAIRE

    Ayyappan, Vasudevan; Kalavacharla, Venu (Kal); Thimmapuram, Jyothi; Bhide, Ketaki P; Sripathi, Venkateswara R.

    2015-01-01

    Histone modifications such as methylation and acetylation play a significant role in controlling gene expression in unstressed and stressed plants. Genome-wide analysis of such stress-responsive modifications and genes in non-model crops is limited. We report the genome-wide profiling of histone methylation (H3K9me2) and acetylation (H4K12ac) in common bean (Phaseolus vulgaris L.) under rust (Uromyces appendiculatus) stress using two high-throughput approaches, chromatin immunoprecipitation s...

  7. Nonredundant requirement for multiple histone modifications for the early anaphase release of the mitotic exit regulator Cdc14 from nucleolar chromatin.

    Directory of Open Access Journals (Sweden)

    William W Hwang

    2009-08-01

    Full Text Available In Saccharomyces cerevisiae, the conserved phosphatase Cdc14 is required for the exit from mitosis. It is anchored on nucleolar chromatin by the Cfi1/Net1 protein until early anaphase, at which time it is released into the nucleoplasm. Two poorly understood, redundant pathways promote Cdc14 release, the FEAR (Cdc fourteen early release network and the MEN (mitotic exit network. Through the analysis of genetic interactions, we report here a novel requirement for the ubiquitination of histone H2B by the Bre1 ubiquitin ligase in the cell cycle-dependent release of Cdc14 from nucleolar chromatin when the MEN is inactivated. This function for H2B ubiquitination is mediated by its activation of histone H3 methylation on lysines 4 and 79 (meH3K4 and meH3K79 but, surprisingly, is not dependent on the histone deacetylase (HDAC Sir2, which associates with Cdc14 on nucleolar chromatin as part of the RENT complex. We also observed a defect in Cdc14 release in cells lacking H3 lysine 36 methylation (meH3K36 and in cells lacking an HDAC recruited by this modification. These histone modifications represent previously unappreciated factors required for the accessibility to and/or action on nucleolar chromatin of FEAR network components. The nonredundant role for these modifications in this context contrasts with the notion of a highly combinatorial code by which histone marks act to control biological processes.

  8. Influence of histones and calcium and magnesium ions on the ultrastructure of chromatin in isolated nuclei of Pinus silvestris L. root meristem

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    Halina Michniewicz

    2015-01-01

    Full Text Available The width of chromatin fibrils in nuclei fixed in situ is about 10 nm. In nuclei isolated in the presence of Ca+2 and Mg+2 ions the fibrils coalesce, and thus their width secondarily increases, whereas in nuclei isolated without the presence of the cations the diameter of fibrils increases somewhat as compared with that in nuclei in situ, probably owing to absorption of nonchromatin nuclear proteins. Lysine histone extraction caused dispersion of condensed chromatin, and reintroduction of these proteins - its reconstruction. On the other hand, extraction and reintroduction of the arginine histone did not cause chromatin dispersion, but rather coalescence of the chromatin mass. Lysine histone extraction from material isolated in the presence of Ca+2 and Mg+2 ions caused the appearance of a large number of 10-nm fibrils, only sporadically seen in the control material, and disappearance of the 30-nm forms. Reintroduction of the lysine histone reduced the number of single fibrils and enhanced the appearance of coalescent form with 30 nm diameter. Removal of arginine histones did not produce disappearance of single fibrils, but reduced their diameter. Reintroduction of this fraction caused coalescence of chromatin threads, owing to which 90 per cent of the population consisted of fibrils with diameter around 30 nm.

  9. Analysis of Myc-induced histone modifications on target chromatin.

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    Francesca Martinato

    Full Text Available The c-myc proto-oncogene is induced by mitogens and is a central regulator of cell growth and differentiation. The c-myc product, Myc, is a transcription factor that binds a multitude of genomic sites, estimated to be over 10-15% of all promoter regions. Target promoters generally pre-exist in an active or poised chromatin state that is further modified by Myc, contributing to fine transcriptional regulation (activation or repression of the afferent gene. Among other mechanisms, Myc recruits histone acetyl-transferases to target chromatin and locally promotes hyper-acetylation of multiple lysines on histones H3 and H4, although the identity and combination of the modified lysines is unknown. Whether Myc dynamically regulates other histone modifications (or marks at its binding sites also remains to be addressed. Here, we