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Sample records for parp inhibition counteracts

  1. REV7 counteracts DNA double-strand break resection and affects PARP inhibition

    NARCIS (Netherlands)

    Xu, Guotai; Chapman, J. Ross; Brandsma, Inger; Yuan, Jingsong; Mistrik, Martin; Bouwman, Peter; Bartkova, Jirina; Gogola, Ewa; Warmerdam, Daniël; Barazas, Marco; Jaspers, Janneke E.; Watanabe, Kenji; Pieterse, Mark; Kersbergen, Ariena; Sol, Wendy; Celie, Patrick H. N.; Schouten, Philip C.; van den Broek, Bram; Salman, Ahmed; Nieuwland, Marja; de Rink, Iris; de Ronde, Jorma; Jalink, Kees; Boulton, Simon J.; Chen, Junjie; van Gent, Dik C.; Bartek, Jiri; Jonkers, Jos; Borst, Piet; Rottenberg, Sven

    2015-01-01

    Error-free repair of DNA double-strand breaks (DSBs) is achieved by homologous recombination (HR), and BRCA1 is an important factor for this repair pathway(1). In the absence of BRCA1-mediated HR, the administration of PARP inhibitors induces synthetic lethality of tumour cells of patients with

  2. PARP-1 inhibition alleviates diabetic cardiac complications in experimental animals.

    Science.gov (United States)

    Zakaria, Esraa M; El-Bassossy, Hany M; El-Maraghy, Nabila N; Ahmed, Ahmed F; Ali, Abdelmoneim A

    2016-11-15

    Cardiovascular complications are the major causes of mortality among diabetic population. Poly(ADP-ribose) polymerase-1 enzyme (PARP-1) is activated by oxidative stress leading to cellular damage. We investigated the implication of PARP-1 in diabetic cardiac complications. Type 2 diabetes was induced in rats by high fructose-high fat diet and low streptozotocin dose. PARP inhibitor 4-aminobenzamide (4-AB) was administered daily for ten weeks after diabetes induction. At the end of study, surface ECG, blood pressure and vascular reactivity were studied. PARP-1 activity, reduced glutathione (GSH) and nitrite contents were assessed in heart muscle. Fasting glucose, fructosamine, insulin, and tumor necrosis factor alpha (TNF-α) levels were measured in serum. Finally, histological examination and collagen deposition detection in rat ventricular and aortic sections were carried out. Hearts isolated from diabetic animals showed increased PARP-1 enzyme activity compared to control animals while significantly reduced by 4-AB administration. PARP-1 inhibition by 4-AB alleviated cardiac ischemia in diabetic animals as indicated by ECG changes. PARP-1 inhibition also reduced cardiac inflammation in diabetic animals as evidenced by histopathological changes. In addition, 4-AB administration improved the elevated blood pressure and the associated exaggerated vascular contractility, endothelial destruction and vascular inflammation seen in diabetic animals. Moreover, PARP-1 inhibition decreased serum levels of TNF-α and cardiac nitrite but increased cardiac GSH contents in diabetic animals. However, PARP-1 inhibition did not significantly affect the developed hyperglycemia. Our findings prove that PARP-1 enzyme plays an important role in diabetic cardiac complications through combining inflammation, oxidative stress, and fibrosis mechanisms. Copyright © 2016. Published by Elsevier B.V.

  3. PARP inhibition versus PARP-1 silencing: different outcomes in terms of single-strand break repair and radiation susceptibility

    International Nuclear Information System (INIS)

    Godon, C.; Cordelieres, F.P.; Giocanti, N.; Megnin-Chanet, F.; Hall, J.; Favaudon, V.; Godon, C.; Giocanti, N.; Megnin-Chanet, F.; Hall, J.; Favaudon, V.; Cordelieres, F.P.; Cordelieres, F.P.; Biard, D.

    2008-01-01

    The consequences of PARP-1 disruption or inhibition on DNA single-strand break repair (SSBR) and radio-induced lethality were determined in synchronized, iso-genic HeLa cells stably silenced or not for poly(ADP-ribose) polymerase-1 (PARP-1) (PARP-1(KD)) or XRCC1 (XRCC1(KD)). PARP-1 inhibition prevented XRCC1-YFP recruitment at sites of 405 nm laser micro irradiation, slowed SSBR 10-fold and triggered the accumulation of large persistent foci of GFP-PARP-1 and GFP-PCNA at photo damaged sites. These aggregates are presumed to hinder the recruitment of other effectors of the base excision repair (BER) pathway.PARP-1 silencing also prevented XRCC1-YFP recruitment but did not lengthen the lifetime of GFP-PCNA foci. Moreover, PARP-1(KD) and XRCC1(KD) cells in S phase completed SSBR as rapidly as controls, while SSBR was delayed in G1. Taken together, the data demonstrate that a PARP-1- and XRCC1-independent SSBR pathway operates when the short patch repair branch of the BER is deficient. Long patch repair is the likely mechanism, as GFP-PCNA recruitment at photo-damaged sites was normal in PARP-1(KD) cells. PARP-1 silencing elicited hyper-radiosensitivity, while radiosensitization by a PARP inhibitor reportedly occurs only in those cells treated in S phase. PARP-1 inhibition and deletion thus have different outcomes in terms of SSBR and radiosensitivity. (authors)

  4. PARP Inhibition Restores Extrinsic Apoptotic Sensitivity in Glioblastoma

    Science.gov (United States)

    Karpel-Massler, Georg; Pareja, Fresia; Aimé, Pascaline; Shu, Chang; Chau, Lily; Westhoff, Mike-Andrew; Halatsch, Marc-Eric; Crary, John F.; Canoll, Peter; Siegelin, Markus D.

    2014-01-01

    Background Resistance to apoptosis is a paramount issue in the treatment of Glioblastoma (GBM). We show that targeting PARP by the small molecule inhibitors, Olaparib (AZD-2281) or PJ34, reduces proliferation and lowers the apoptotic threshold of GBM cells in vitro and in vivo. Methods The sensitizing effects of PARP inhibition on TRAIL-mediated apoptosis and potential toxicity were analyzed using viability assays and flow cytometry in established GBM cell lines, low-passage neurospheres and astrocytes in vitro. Molecular analyses included western blots and gene silencing. In vivo, effects on tumor growth were examined in a murine subcutaneous xenograft model. Results The combination treatment of PARP inhibitors and TRAIL led to an increased cell death with activation of caspases and inhibition of formation of neurospheres when compared to single-agent treatment. Mechanistically, pharmacological PARP inhibition elicited a nuclear stress response with up-regulation of down-stream DNA-stress response proteins, e.g., CCAAT enhancer binding protein (C/EBP) homology protein (CHOP). Furthermore, Olaparib and PJ34 increased protein levels of DR5 in a concentration and time-dependent manner. In turn, siRNA-mediated suppression of DR5 mitigated the effects of TRAIL/PARP inhibitor-mediated apoptosis. In addition, suppression of PARP-1 levels enhanced TRAIL-mediated apoptosis in malignant glioma cells. Treatment of human astrocytes with the combination of TRAIL/PARP inhibitors did not cause toxicity. Finally, the combination treatment of TRAIL and PJ34 significantly reduced tumor growth in vivo when compared to treatment with each agent alone. Conclusions PARP inhibition represents a promising avenue to overcome apoptotic resistance in GBM. PMID:25531448

  5. Inhibition of matrix metalloproteinase-2 by PARP inhibitors

    International Nuclear Information System (INIS)

    Nicolescu, Adrian C.; Holt, Andrew; Kandasamy, Arulmozhi D.; Pacher, Pal; Schulz, Richard

    2009-01-01

    Matrix metalloproteinase-2 (MMP-2), a ubiquitously expressed zinc-dependent endopeptidase, and poly(ADP-ribosyl) polymerase (PARP), a nuclear enzyme regulating DNA repair, are activated by nitroxidative stress associated with various pathologies. As MMP-2 plays a detrimental role in heart injuries resulting from enhanced nitroxidative stress, where PARP and MMP inhibitors are beneficial, we hypothesized that PARP inhibitors may affect MMP-2 activity. Using substrate degradation assays to determine MMP-2 activity we found that four PARP inhibitors (3-AB, PJ-34, 5-AIQ, and EB-47) inhibited 64 kDa MMP-2 in a concentration-dependent manner. The IC 50 values of PJ-34 and 5-AIQ were in the high micromolar range and comparable to those of known MMP-2 inhibitors doxycycline, minocycline or o-phenanthroline, whereas those for 3-AB and EB-47 were in the millimolar range. Co-incubation of PARP inhibitors with doxycycline showed an additive inhibition of MMP-2 that was significant for 3-AB alone. These data demonstrate that the protective effects of some PARP inhibitors may include inhibition of MMP-2 activity.

  6. Inhibition of matrix metalloproteinase-2 by PARP inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Nicolescu, Adrian C.; Holt, Andrew; Kandasamy, Arulmozhi D. [Departments of Pharmacology and Pediatrics, Cardiovascular Research Centre, University of Alberta, Edmonton, Alta., Canada T6G 2S2 (Canada); Pacher, Pal [National Institutes of Health, NIAAA, Laboratory of Physiologic Studies, Bethesda, MD (United States); Schulz, Richard, E-mail: richard.schulz@ualberta.ca [Departments of Pharmacology and Pediatrics, Cardiovascular Research Centre, University of Alberta, Edmonton, Alta., Canada T6G 2S2 (Canada)

    2009-10-02

    Matrix metalloproteinase-2 (MMP-2), a ubiquitously expressed zinc-dependent endopeptidase, and poly(ADP-ribosyl) polymerase (PARP), a nuclear enzyme regulating DNA repair, are activated by nitroxidative stress associated with various pathologies. As MMP-2 plays a detrimental role in heart injuries resulting from enhanced nitroxidative stress, where PARP and MMP inhibitors are beneficial, we hypothesized that PARP inhibitors may affect MMP-2 activity. Using substrate degradation assays to determine MMP-2 activity we found that four PARP inhibitors (3-AB, PJ-34, 5-AIQ, and EB-47) inhibited 64 kDa MMP-2 in a concentration-dependent manner. The IC{sub 50} values of PJ-34 and 5-AIQ were in the high micromolar range and comparable to those of known MMP-2 inhibitors doxycycline, minocycline or o-phenanthroline, whereas those for 3-AB and EB-47 were in the millimolar range. Co-incubation of PARP inhibitors with doxycycline showed an additive inhibition of MMP-2 that was significant for 3-AB alone. These data demonstrate that the protective effects of some PARP inhibitors may include inhibition of MMP-2 activity.

  7. Increased oxidative stress mediates the antitumor effect of PARP inhibition in ovarian cancer

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    Dong Hou

    2018-07-01

    Full Text Available PARP inhibitors have been widely tested in clinical trials, especially for the treatment of breast cancer and ovarian cancer, and were shown to be highly successful. Because PARP primarily functions in sensing and repairing DNA strand breaks, the therapeutic effect of PARP inhibition is generally believed to be attributed to impaired DNA repair. We here report that oxidative stress is also increased by PARP inhibition and mediates the antitumor effect. We showed that PARP1 is highly expressed in specimens of high grade serous ovarian carcinoma and its activity is required for unperturbed proliferation of ovarian cancer cells. Inhibition or depletion of PARP leads to not only an increase in DNA damage, but also an elevation in the levels of reactive oxygen species (ROS. Importantly, antioxidant N-acetylcysteine (NAC significantly attenuated the induction of DNA damage and the perturbation of proliferation by PARP inhibition or depletion. We further showed that NADPH oxidases 1 and 4 were significantly upregulated by PARP inhibition and were partially responsible for the induction of oxidative stress. Depletion of NOX1 and NOX4 partially rescued the growth inhibition of PARP1-deficient tumor xenografts. Our findings suggest that in addition to compromising the repair of DNA damage, PARP inhibition or depletion may exert extra antitumor effect by elevating oxidative stress in ovarian cancer cells. Keywords: PARP1, Oxidative stress, NADPH oxidases, Ovarian cancer

  8. Trial watch – inhibiting PARP enzymes for anticancer therapy

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    Sistigu, Antonella; Manic, Gwenola; Obrist, Florine; Vitale, Ilio

    2016-01-01

    ABSTRACT Poly(ADP-ribose) polymerases (PARPs) are a members of family of enzymes that catalyze poly(ADP-ribosyl)ation (PARylation) and/or mono(ADP-ribosyl)ation (MARylation), two post-translational protein modifications involved in crucial cellular processes including (but not limited to) the DNA damage response (DDR). PARP1, the most abundant family member, is a nuclear protein that is activated upon sensing distinct types of DNA damage and contributes to their resolution by PARylating multiple DDR players. Recent evidence suggests that, along with DDR, activated PARP1 mediates a series of prosurvival and proapoptotic processes aimed at preserving genomic stability. Despite this potential oncosuppressive role, upregulation and/or overactivation of PARP1 or other PARP enzymes has been reported in a variety of human neoplasms. Over the last few decades, several pharmacologic inhibitors of PARP1 and PARP2 have been assessed in preclinical and clinical studies showing potent antineoplastic activity, particularly against homologous recombination (HR)-deficient ovarian and breast cancers. In this Trial Watch, we describe the impact of PARP enzymes and PARylation in cancer, discuss the mechanism of cancer cell killing by PARP1 inactivation, and summarize the results of recent clinical studies aimed at evaluating the safety and therapeutic profile of PARP inhibitors in cancer patients. PMID:27308587

  9. PARP Inhibition Attenuates Histopathological Lesion in Ischemia/Reperfusion Renal Mouse Model after Cold Prolonged Ischemia

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    Raimundo M. G. del Moral

    2013-01-01

    Full Text Available We test the hypothesis that PARP inhibition can decrease acute tubular necrosis (ATN and other renal lesions related to prolonged cold ischemia/reperfusion (IR in kidneys preserved at 4°C in University of Wisconsin (UW solution. Material and Methods. We used 30 male Parp1+/+ wild-type and 15 male Parp10/0 knockout C57BL/6 mice. Fifteen of these wild-type mice were pretreated with 3,4-dihydro-5-[4-(1-piperidinylbutoxyl]-1(2H-isoquinolinone (DPQ at a concentration of 15 mg/kg body weight, used as PARP inhibitor. Subgroups of mice were established (A: IR 45 min/6 h; B: IR + 48 h in UW solution; and C: IR + 48 h in UW solution plus DPQ. We processed samples for morphological, immunohistochemical, ultrastructural, and western-blotting studies. Results. Prolonged cold ischemia time in UW solution increased PARP-1 expression and kidney injury. Preconditioning with PARP inhibitor DPQ plus DPQ supplementation in UW solution decreased PARP-1 nuclear expression in renal tubules and renal damage. Parp10/0 knockout mice were more resistant to IR-induced renal lesion. In conclusion, PARP inhibition attenuates ATN and other IR-related renal lesions in mouse kidneys under prolonged cold storage in UW solution. If confirmed, these data suggest that pharmacological manipulation of PARP activity may have salutary effects in cold-stored organs at transplantation.

  10. Arsenite binding-induced zinc loss from PARP-1 is equivalent to zinc deficiency in reducing PARP-1 activity, leading to inhibition of DNA repair

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    Sun, Xi; Zhou, Xixi [Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States); Du, Libo [Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Liu, Wenlan [Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States); Liu, Yang [Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Hudson, Laurie G. [Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States); Liu, Ke Jian, E-mail: kliu@salud.unm.edu [Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States)

    2014-01-15

    Inhibition of DNA repair is a recognized mechanism for arsenic enhancement of ultraviolet radiation-induced DNA damage and carcinogenesis. Poly(ADP-ribose) polymerase-1 (PARP-1), a zinc finger DNA repair protein, has been identified as a sensitive molecular target for arsenic. The zinc finger domains of PARP-1 protein function as a critical structure in DNA recognition and binding. Since cellular poly(ADP-ribosyl)ation capacity has been positively correlated with zinc status in cells, we hypothesize that arsenite binding-induced zinc loss from PARP-1 is equivalent to zinc deficiency in reducing PARP-1 activity, leading to inhibition of DNA repair. To test this hypothesis, we compared the effects of arsenite exposure with zinc deficiency, created by using the membrane-permeable zinc chelator TPEN, on 8-OHdG formation, PARP-1 activity and zinc binding to PARP-1 in HaCat cells. Our results show that arsenite exposure and zinc deficiency had similar effects on PARP-1 protein, whereas supplemental zinc reversed these effects. To investigate the molecular mechanism of zinc loss induced by arsenite, ICP-AES, near UV spectroscopy, fluorescence, and circular dichroism spectroscopy were utilized to examine arsenite binding and occupation of a peptide representing the first zinc finger of PARP-1. We found that arsenite binding as well as zinc loss altered the conformation of zinc finger structure which functionally leads to PARP-1 inhibition. These findings suggest that arsenite binding to PARP-1 protein created similar adverse biological effects as zinc deficiency, which establishes the molecular mechanism for zinc supplementation as a potentially effective treatment to reverse the detrimental outcomes of arsenic exposure. - Highlights: • Arsenite binding is equivalent to zinc deficiency in reducing PARP-1 function. • Zinc reverses arsenic inhibition of PARP-1 activity and enhancement of DNA damage. • Arsenite binding and zinc loss alter the conformation of zinc finger

  11. Arsenite binding-induced zinc loss from PARP-1 is equivalent to zinc deficiency in reducing PARP-1 activity, leading to inhibition of DNA repair

    International Nuclear Information System (INIS)

    Sun, Xi; Zhou, Xixi; Du, Libo; Liu, Wenlan; Liu, Yang; Hudson, Laurie G.; Liu, Ke Jian

    2014-01-01

    Inhibition of DNA repair is a recognized mechanism for arsenic enhancement of ultraviolet radiation-induced DNA damage and carcinogenesis. Poly(ADP-ribose) polymerase-1 (PARP-1), a zinc finger DNA repair protein, has been identified as a sensitive molecular target for arsenic. The zinc finger domains of PARP-1 protein function as a critical structure in DNA recognition and binding. Since cellular poly(ADP-ribosyl)ation capacity has been positively correlated with zinc status in cells, we hypothesize that arsenite binding-induced zinc loss from PARP-1 is equivalent to zinc deficiency in reducing PARP-1 activity, leading to inhibition of DNA repair. To test this hypothesis, we compared the effects of arsenite exposure with zinc deficiency, created by using the membrane-permeable zinc chelator TPEN, on 8-OHdG formation, PARP-1 activity and zinc binding to PARP-1 in HaCat cells. Our results show that arsenite exposure and zinc deficiency had similar effects on PARP-1 protein, whereas supplemental zinc reversed these effects. To investigate the molecular mechanism of zinc loss induced by arsenite, ICP-AES, near UV spectroscopy, fluorescence, and circular dichroism spectroscopy were utilized to examine arsenite binding and occupation of a peptide representing the first zinc finger of PARP-1. We found that arsenite binding as well as zinc loss altered the conformation of zinc finger structure which functionally leads to PARP-1 inhibition. These findings suggest that arsenite binding to PARP-1 protein created similar adverse biological effects as zinc deficiency, which establishes the molecular mechanism for zinc supplementation as a potentially effective treatment to reverse the detrimental outcomes of arsenic exposure. - Highlights: • Arsenite binding is equivalent to zinc deficiency in reducing PARP-1 function. • Zinc reverses arsenic inhibition of PARP-1 activity and enhancement of DNA damage. • Arsenite binding and zinc loss alter the conformation of zinc finger

  12. Differential sensitivities of cellular XPA and PARP-1 to arsenite inhibition and zinc rescue.

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    Ding, Xiaofeng; Zhou, Xixi; Cooper, Karen L; Huestis, Juliana; Hudson, Laurie G; Liu, Ke Jian

    2017-09-15

    Arsenite directly binds to the zinc finger domains of the DNA repair protein poly (ADP ribose) polymerase (PARP)-1, and inhibits PARP-1 activity in the base excision repair (BER) pathway. PARP inhibition by arsenite enhances ultraviolet radiation (UVR)-induced DNA damage in keratinocytes, and the increase in DNA damage is reduced by zinc supplementation. However, little is known about the effects of arsenite and zinc on the zinc finger nucleotide excision repair (NER) protein xeroderma pigmentosum group A (XPA). In this study, we investigated the difference in response to arsenite exposure between XPA and PARP-1, and the differential effectiveness of zinc supplementation in restoring protein DNA binding and DNA damage repair. Arsenite targeted both XPA and PARP-1 in human keratinocytes, resulting in zinc loss from each protein and a pronounced decrease in XPA and PARP-1 binding to chromatin as demonstrated by Chip-on-Western assays. Zinc effectively restored DNA binding of PARP-1 and XPA to chromatin when zinc concentrations were equal to those of arsenite. In contrast, zinc was more effective in rescuing arsenite-augmented direct UVR-induced DNA damage than oxidative DNA damage. Taken together, our findings indicate that arsenite interferes with PARP-1 and XPA binding to chromatin, and that zinc supplementation fully restores DNA binding activity to both proteins in the cellular context. Interestingly, rescue of arsenite-inhibited DNA damage repair by supplemental zinc was more sensitive for DNA damage repaired by the XPA-associated NER pathway than for the PARP-1-dependent BER pathway. This study expands our understanding of arsenite's role in DNA repair inhibition and co-carcinogenesis. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. PARP activity and inhibition in fetal and adult oligodendrocyte precursor cells: Effect on cell survival and differentiation.

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    Baldassarro, Vito A; Marchesini, Alessandra; Giardino, Luciana; Calzà, Laura

    2017-07-01

    Poly (ADP-ribose) polymerase (PARP) family members are ubiquitously expressed and play a key role in cellular processes, including DNA repair and cell death/survival balance. Accordingly, PARP inhibition is an emerging pharmacological strategy for cancer and neurodegenerative diseases. Consistent evidences support the critical involvement of PARP family members in cell differentiation and phenotype maturation. In this study we used an oligodendrocyte precursor cells (OPCs) enriched system derived from fetal and adult brain to investigate the role of PARP in OPCs proliferation, survival, and differentiation. The PARP inhibitors PJ34, TIQ-A and Olaparib were used as pharmacological tools. The main results of the study are: (i) PARP mRNA expression and PARP activity are much higher in fetal than in adult-derived OPCs; (ii) the culture treatment with PARP inhibitors is cytotoxic for OPCs derived from fetal, but not from adult, brain; (iii) PARP inhibition reduces cell number, according to the inhibitory potency of the compounds; (iv) PARP inhibition effect on fetal OPCs is a slow process; (v) PARP inhibition impairs OPCs maturation into myelinating OL in fetal, but not in adult cultures, according to the inhibitory potency of the compounds. These results have implications for PARP-inhibition therapies for diseases and lesions of the central nervous system, in particular for neonatal hypoxic/ischemic encephalopathy. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  14. Theophylline prevents NAD+ depletion via PARP-1 inhibition in human pulmonary epithelial cells

    International Nuclear Information System (INIS)

    Moonen, Harald J.J.; Geraets, Liesbeth; Vaarhorst, Anika; Bast, Aalt; Wouters, Emiel F.M.; Hageman, Geja J.

    2005-01-01

    Oxidative DNA damage, as occurs during exacerbations in chronic obstructive pulmonary disease (COPD), highly activates the nuclear enzyme poly(ADP-ribose)polymerase-1 (PARP-1). This can lead to cellular depletion of its substrate NAD + , resulting in an energy crisis and ultimately in cell death. Inhibition of PARP-1 results in preservation of the intracellular NAD + pool, and of NAD + -dependent cellular processes. In this study, PARP-1 activation by hydrogen peroxide decreased intracellular NAD + levels in human pulmonary epithelial cells, which was found to be prevented in a dose-dependent manner by theophylline, a widely used compound in the treatment of COPD. This enzyme inhibition by theophylline was confirmed in an ELISA using purified human PARP-1 and was found to be competitive by nature. These findings provide new mechanistic insights into the therapeutic effect of theophylline in oxidative stress-induced lung pathologies

  15. Targeted Radiosensitization of ETS Fusion-Positive Prostate Cancer through PARP1 Inhibition

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    Sumin Han

    2013-10-01

    Full Text Available ETS gene fusions, which result in overexpression of an ETS transcription factor, are considered driving mutations in approximately half of all prostate cancers. Dysregulation of ETS transcription factors is also known to exist in Ewing's sarcoma, breast cancer, and acute lymphoblastic leukemia. We previously discovered that ERG, the predominant ETS family member in prostate cancer, interacts with the DNA damage response protein poly (ADP-ribose polymerase 1 (PARP1 in human prostate cancer specimens. Therefore, we hypothesized that the ERG-PARP1 interaction may confer radiation resistance by increasing DNA repair efficiency and that this radio-resistance could be reversed through PARP1 inhibition. Using lentiviral approaches, we established isogenic models of ERG overexpression in PC3 and DU145 prostate cancer cell lines. In both cell lines, ERG overexpression increased clonogenic survival following radiation by 1.25 (±0.07 fold (mean ± SEM and also resulted in increased PARP1 activity. PARP1 inhibition with olaparib preferentially radiosensitized ERG-positive cells by a factor of 1.52 (±0.03 relative to ERG-negative cells (P < .05. Neutral and alkaline COMET assays and immunofluorescence microscopy assessing γ-H2AX foci showed increased short- and long-term efficiencies of DNA repair, respectively, following radiation that was preferentially reversed by PARP1 inhibition. These findings were verified in an in vivo xenograft model. Our findings demonstrate that ERG overexpression confers radiation resistance through increased efficiency of DNA repair following radiation that can be reversed through inhibition of PARP1. These results motivate the use of PARP1 inhibitors as radiosensitizers in patients with localized ETS fusion-positive cancers.

  16. Nicotinamide Inhibits Ethanol-Induced Caspase-3 and PARP-1 Over-activation and Subsequent Neurodegeneration in the Developing Mouse Cerebellum.

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    Ieraci, Alessandro; Herrera, Daniel G

    2018-06-01

    Fetal alcohol spectrum disorder (FASD) is the principal preventable cause of mental retardation in the western countries resulting from alcohol exposure during pregnancy. Ethanol-induced massive neuronal cell death occurs mainly in immature neurons during the brain growth spurt period. The cerebellum is one of the brain areas that are most sensitive to ethanol neurotoxicity. Currently, there is no effective treatment that targets the causes of these disorders and efficient treatments to counteract or reverse FASD are desirable. In this study, we investigated the effects of nicotinamide on ethanol-induced neuronal cell death in the developing cerebellum. Subcutaneous administration of ethanol in postnatal 4-day-old mice induced an over-activation of caspase-3 and PARP-1 followed by a massive neurodegeneration in the developing cerebellum. Interestingly, treatment with nicotinamide, immediately or 2 h after ethanol exposure, diminished caspase-3 and PARP-1 over-activation and reduced ethanol-induced neurodegeneration. Conversely, treatment with 3-aminobenzadine, a specific PARP-1 inhibitor, was able to completely block PARP-1 activation, but not caspase-3 activation or ethanol-induced neurodegeneration in the developing cerebellum. Our results showed that nicotinamide reduces ethanol-induced neuronal cell death and inhibits both caspase-3 and PARP-1 alcohol-induced activation in the developing cerebellum, suggesting that nicotinamide might be a promising and safe neuroprotective agent for treating FASD and other neurodegenerative disorders in the developing brain that shares similar cell death pathways.

  17. BET Bromodomain Inhibition Synergizes with PARP Inhibitor in Epithelial Ovarian Cancer

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    Sergey Karakashev

    2017-12-01

    Full Text Available PARP inhibition is known to be an effective clinical strategy in BRCA mutant cancers, but PARP inhibition has not been applied to BRCA-proficient tumors. Here, we show the synergy of BET bromodomain inhibition with PARP inhibition in BRCA-proficient ovarian cancers due to mitotic catastrophe. Treatment of BRCA-proficient ovarian cancer cells with the BET inhibitor JQ1 downregulated the G2-M cell-cycle checkpoint regulator WEE1 and the DNA-damage response factor TOPBP1. Combining PARP inhibitor Olaparib with the BET inhibitor, we observed a synergistic increase in DNA damage and checkpoint defects, which allowed cells to enter mitosis despite the accumulation of DNA damage, ultimately causing mitotic catastrophe. Moreover, JQ1 and Olaparib showed synergistic suppression of growth of BRCA-proficient cancer in vivo in a xenograft ovarian cancer mouse model. Our findings indicate that a combination of BET inhibitor and PARP inhibitor represents a potential therapeutic strategy for BRCA-proficient cancers.

  18. PARP-1 Inhibition Is Neuroprotective in the R6/2 Mouse Model of Huntington's Disease.

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    Antonella Cardinale

    Full Text Available Poly (ADP-ribose polymerase 1 (PARP-1 is a nuclear enzyme that is involved in physiological processes as DNA repair, genomic stability, and apoptosis. Moreover, published studies demonstrated that PARP-1 mediates necrotic cell death in response to excessive DNA damage under certain pathological conditions. In Huntington's disease brains, PARP immunoreactivity was described in neurons and in glial cells, thereby suggesting the involvement of apoptosis in HD. In this study, we sought to determine if the PARP-1 inhibitor exerts a neuroprotective effect in R6/2 mutant mice, which recapitulates, in many aspects, human HD. Transgenic mice were treated with the PARP-1 inhibitor INO-1001 mg/Kg daily starting from 4 weeks of age. After transcardial perfusion, histological and immunohistochemical studies were performed. We found that INO 1001-treated R6/2 mice survived longer and displayed less severe signs of neurological dysfunction than the vehicle treated ones. Primary outcome measures such as striatal atrophy, morphology of striatal neurons, neuronal intranuclear inclusions and microglial reaction confirmed a neuroprotective effect of the compound. INO-1001 was effective in significantly increasing activated CREB and BDNF in the striatal spiny neurons, which might account for the beneficial effects observed in this model. Our findings show that PARP-1 inhibition could be considered as a valid therapeutic approach for HD.

  19. Hyperthermia and PARP1-inhibition for sensitization of radiation and cisplatin treatment of cervical carcinoma cells

    International Nuclear Information System (INIS)

    Franken, Nicolaas; Oei, Arlene; Leeuwen, Caspar van; Stalpers, Lukas; Rodermond, Hans; Bel, Arjan; Kok, Petra; Crezee, Hans

    2014-01-01

    Ionizing radiation causes single and double strand breaks (SSBs and DSBs). DSBs are among the most critical DNA lesions and can be repaired via either non-homologous end joining (NHEJ) in which PARP1, Ku70 and DNA-PKcs are important, or homologous recombination (HR), where BRCA2 and Rad51 are essential. Hyperthermia disturbs HR by temporary inactivation of BRCA2. Cisplatin disrupts NHEJ and PARP1-inhibitor blocks Poly-(ADP-ribose)polymerase- 1, which is important in SSB repair, NHEJ and backup-NHEJ. Our goal was to investigate the additional effectiveness of hyperthermia and PARP1-inhibition on radiation and/or cisplatin treatment. Cervical carcinoma cells (SiHa) were treated at different temperature levels levels (41.0-43.0℃, PARP1-inhibitor (100 μM; NU1025), gamma-irradiation doses (0-8 Gy) or cisplatin (1'R for 1 h). Clonogenic assays were carried out to measure survival and γH2AX staining was used to visualize DSBs. To elucidate mechanisms of action expression levels of DNA repair proteins BRCA2 and DNA-PKcs were investigated after 42.0℃ (1 h) using western blot. Combined hyperthermia and radiation resulted in an increased number of γH2AX foci as compared to radiation alone. Hyperthermia treatment in combination with cisplatin and PARP1 inhibitor and with radiation and PARP1 inhibitor significantly decreased cell survival. Western blot demonstrated a decreased expression of BRCA2 protein at 30 min after hyperthermia treatment. Adding PARP1-inhibitor significantly improves the effectiveness of combined hyperthermia radiotherapy and combined hyperthermia-cisplatin treatment on cervical carcinoma cells. Hyperthermia affects DNA-DSB repair as is indicated by increased γH2AX foci numbers and decreased BRCA2 expression. (author)

  20. Pathway-Enriched Gene Signature Associated with 53BP1 Response to PARP Inhibition in Triple-Negative Breast Cancer.

    Science.gov (United States)

    Hassan, Saima; Esch, Amanda; Liby, Tiera; Gray, Joe W; Heiser, Laura M

    2017-12-01

    Effective treatment of patients with triple-negative (ER-negative, PR-negative, HER2-negative) breast cancer remains a challenge. Although PARP inhibitors are being evaluated in clinical trials, biomarkers are needed to identify patients who will most benefit from anti-PARP therapy. We determined the responses of three PARP inhibitors (veliparib, olaparib, and talazoparib) in a panel of eight triple-negative breast cancer cell lines. Therapeutic responses and cellular phenotypes were elucidated using high-content imaging and quantitative immunofluorescence to assess markers of DNA damage (53BP1) and apoptosis (cleaved PARP). We determined the pharmacodynamic changes as percentage of cells positive for 53BP1, mean number of 53BP1 foci per cell, and percentage of cells positive for cleaved PARP. Inspired by traditional dose-response measures of cell viability, an EC 50 value was calculated for each cellular phenotype and each PARP inhibitor. The EC 50 values for both 53BP1 metrics strongly correlated with IC 50 values for each PARP inhibitor. Pathway enrichment analysis identified a set of DNA repair and cell cycle-associated genes that were associated with 53BP1 response following PARP inhibition. The overall accuracy of our 63 gene set in predicting response to olaparib in seven breast cancer patient-derived xenograft tumors was 86%. In triple-negative breast cancer patients who had not received anti-PARP therapy, the predicted response rate of our gene signature was 45%. These results indicate that 53BP1 is a biomarker of response to anti-PARP therapy in the laboratory, and our DNA damage response gene signature may be used to identify patients who are most likely to respond to PARP inhibition. Mol Cancer Ther; 16(12); 2892-901. ©2017 AACR . ©2017 American Association for Cancer Research.

  1. The inhibition of PARP but not EGFR results in the radiosensitization of HPV/p16-positive HNSCC cell lines

    International Nuclear Information System (INIS)

    Güster, Julian David; Weissleder, Stephanie Valerie; Busch, Chia-Jung; Kriegs, Malte; Petersen, Cordula; Knecht, Rainald; Dikomey, Ekkehard; Rieckmann, Thorsten

    2014-01-01

    Background and purpose: HPV-negative and HPV-positive HNSCC comprise distinct tumor entities with different biological characteristics. Specific regimens for the comparably well curable HPV-positive entity that reduce side effects without compromising outcome have yet to be established. Therefore, we tested here whether the inhibition of EGFR or PARP may be used to specifically enhance the radiosensitivity of HPV-positive HNSCC cells. Materials and methods: Experiments were performed with five HPV/p16-positive HNSCC cell lines. Inhibitors used were cetuximab, olaparib and PF-00477736. The respective inhibition of EGFR, PARP and Chk1 was evaluated by Western blot, immunofluorescence analysis and assessment of cell cycle distribution. Cell survival was assessed by colony formation assay. Results: Inhibition of EGFR by cetuximab failed to radiosensitize any of the HPV-positive HNSCC cell lines tested. In contrast, PARP-inhibition resulted in a substantial radiosensitization of all strains, with the sensitization being further enhanced by the additional inhibition of Chk1. Conclusions: PARP-inhibition effectively radiosensitizes HPV-positive HNSCC cells and may therefore represent a viable alternative to chemotherapy possibly even allowing for a reduction in radiation dose. For the latter, PARP-inhibition may be combined with the inhibition of Chk1. In contrast, the inhibition of EGFR cannot be expected to radiosensitize HPV-positive HNSCC through the modulation of cellular radiosensitivity

  2. The dual action of poly(ADP-ribose polymerase -1 (PARP-1 inhibition in HIV-1 infection: HIV-1 LTR inhibition and diminution in Rho GTPase activity

    Directory of Open Access Journals (Sweden)

    Slava eRom

    2015-08-01

    Full Text Available The transcription of HIV-1 (HIV is regulated by complex mechanisms involving various cellular factors and virus-encoded transactivators. Poly(ADP-ribose polymerase 1 (PARP-1 inhibition has emerged recently as a potent anti-inflammatory tool, since PARP-1 is involved in the regulation of some genes through its interaction with various transcription factors. We propose a novel approach to diminish HIV replication via PARP-1 inhibition using human primary monocyte-derived macrophages (MDM as an in vitro model system. PARP-1 inhibitors were able to reduce HIV replication in MDM by 60-80% after 7 days infection. Long Terminal Repeat (LTR acts as a switch in virus replication and can be triggered by several agents such as: Tat, tumor necrosis factor α (TNFα, and phorbol 12-myristate 13-acetate (PMA. Overexpression of Tat in MDM transfected with an LTR reporter plasmid led to a 4.2-fold increase in LTR activation; PARP inhibition resulted in 70% reduction of LTR activity. LTR activity, which increased 3-fold after PMA or TNFα treatment, was reduced by PARP inhibition (by 85-95%. MDM treated with PARP inhibitors showed 90% reduction in NFκB activity (known to mediate PMA- and TNFα-induced HIV LTR activation. Cytoskeleton rearrangements are important in effective HIV-1 infection. PARP inactivation reduced actin cytoskeleton rearrangements by affecting Rho GTPase machinery. These findings suggest that HIV replication in MDM could be suppressed by PARP inhibition via NFκB suppression, diminution of LTR activation and its effects on the cytoskeleton. PARP appears to be essential for HIV replication and its inhibition may provide a potent approach to treatment of HIV infection.

  3. Targeting EGFR induced oxidative stress by PARP1 inhibition in glioblastoma therapy.

    Science.gov (United States)

    Nitta, Masayuki; Kozono, David; Kennedy, Richard; Stommel, Jayne; Ng, Kimberly; Zinn, Pascal O; Kushwaha, Deepa; Kesari, Santosh; Inda, Maria-del-Mar; Wykosky, Jill; Furnari, Frank; Hoadley, Katherine A; Chin, Lynda; DePinho, Ronald A; Cavenee, Webster K; D'Andrea, Alan; Chen, Clark C

    2010-05-24

    Despite the critical role of Epidermal Growth Factor Receptor (EGFR) in glioblastoma pathogenesis, EGFR targeted therapies have achieved limited clinical efficacy. Here we propose an alternate therapeutic strategy based on the conceptual framework of non-oncogene addiction. A directed RNAi screen revealed that glioblastoma cells over-expressing EGFRvIII, an oncogenic variant of EGFR, become hyper-dependent on a variety of DNA repair genes. Among these, there was an enrichment of Base Excision Repair (BER) genes required for the repair of Reactive Oxygen Species (ROS)-induced DNA damage, including poly-ADP ribose polymerase 1 (PARP1). Subsequent studies revealed that EGFRvIII over-expression in glioblastoma cells caused increased levels of ROS, DNA strand break accumulation, and genome instability. In a panel of primary glioblastoma lines, sensitivity to PARP1 inhibition correlated with the levels of EGFR activation and oxidative stress. Gene expression analysis indicated that reduced expression of BER genes in glioblastomas with high EGFR expression correlated with improved patient survival. These observations suggest that oxidative stress secondary to EGFR hyper-activation necessitates increased cellular reliance on PARP1 mediated BER, and offer critical insights into clinical trial design.

  4. Targeting EGFR induced oxidative stress by PARP1 inhibition in glioblastoma therapy.

    Directory of Open Access Journals (Sweden)

    Masayuki Nitta

    Full Text Available Despite the critical role of Epidermal Growth Factor Receptor (EGFR in glioblastoma pathogenesis, EGFR targeted therapies have achieved limited clinical efficacy. Here we propose an alternate therapeutic strategy based on the conceptual framework of non-oncogene addiction. A directed RNAi screen revealed that glioblastoma cells over-expressing EGFRvIII, an oncogenic variant of EGFR, become hyper-dependent on a variety of DNA repair genes. Among these, there was an enrichment of Base Excision Repair (BER genes required for the repair of Reactive Oxygen Species (ROS-induced DNA damage, including poly-ADP ribose polymerase 1 (PARP1. Subsequent studies revealed that EGFRvIII over-expression in glioblastoma cells caused increased levels of ROS, DNA strand break accumulation, and genome instability. In a panel of primary glioblastoma lines, sensitivity to PARP1 inhibition correlated with the levels of EGFR activation and oxidative stress. Gene expression analysis indicated that reduced expression of BER genes in glioblastomas with high EGFR expression correlated with improved patient survival. These observations suggest that oxidative stress secondary to EGFR hyper-activation necessitates increased cellular reliance on PARP1 mediated BER, and offer critical insights into clinical trial design.

  5. Upregulation of PEDF expression by PARP inhibition contributes to the decrease in hyperglycemia-induced apoptosis in HUVECs

    International Nuclear Information System (INIS)

    Chen Haibing; Jia Weiping; Xu Xun; Fan Ying; Zhu Dongqing; Wu Haixiang; Xie Zhenggao; Zheng Zhi

    2008-01-01

    Poly(ADP-ribose)polymerase (PARP) inhibitors decrease angiogenesis through reducing vascular endothelium growth factor (VEGF) induced proliferation, migration, and tube formation of human umbilical vein endothelial cells (HUVECs). In contrast to VEGF, pigment epithelium-derived factor (PEDF) has been demonstrated to act as a strong endogenous inhibitor of angiogenesis. Here, we show that PARP inhibition with a specific inhibitor PJ-34 or specific PARP antisense oligonucleotide upregulates hyperglycemia-induced PEDF expression in HUVECs in a dose-dependent manner. This results in the retard of activation of p38 MAP kinase and the concomitant decrease in cell apoptosis. These results give the first direct demonstration that PEDF might represent a target for PARP inhibition treatment and the effects of PEDF on endothelial cells growth are context dependent

  6. Pyrimidine Pool Disequilibrium Induced by a Cytidine Deaminase Deficiency Inhibits PARP-1 Activity, Leading to the Under Replication of DNA.

    Directory of Open Access Journals (Sweden)

    Simon Gemble

    2015-07-01

    Full Text Available Genome stability is jeopardized by imbalances of the dNTP pool; such imbalances affect the rate of fork progression. For example, cytidine deaminase (CDA deficiency leads to an excess of dCTP, slowing the replication fork. We describe here a novel mechanism by which pyrimidine pool disequilibrium compromises the completion of replication and chromosome segregation: the intracellular accumulation of dCTP inhibits PARP-1 activity. CDA deficiency results in incomplete DNA replication when cells enter mitosis, leading to the formation of ultrafine anaphase bridges between sister-chromatids at "difficult-to-replicate" sites such as centromeres and fragile sites. Using molecular combing, electron microscopy and a sensitive assay involving cell imaging to quantify steady-state PAR levels, we found that DNA replication was unsuccessful due to the partial inhibition of basal PARP-1 activity, rather than slower fork speed. The stimulation of PARP-1 activity in CDA-deficient cells restores replication and, thus, chromosome segregation. Moreover, increasing intracellular dCTP levels generates under-replication-induced sister-chromatid bridges as efficiently as PARP-1 knockdown. These results have direct implications for Bloom syndrome (BS, a rare genetic disease combining susceptibility to cancer and genomic instability. BS results from mutation of the BLM gene, encoding BLM, a RecQ 3'-5' DNA helicase, a deficiency of which leads to CDA downregulation. BS cells thus have a CDA defect, resulting in a high frequency of ultrafine anaphase bridges due entirely to dCTP-dependent PARP-1 inhibition and independent of BLM status. Our study describes previously unknown pathological consequences of the distortion of dNTP pools and reveals an unexpected role for PARP-1 in preventing DNA under-replication and chromosome segregation defects.

  7. Suppression of Homologous Recombination by insulin-like growth factor-1 inhibition sensitizes cancer cells to PARP inhibitors

    International Nuclear Information System (INIS)

    Amin, Oreekha; Beauchamp, Marie-Claude; Nader, Paul Abou; Laskov, Ido; Iqbal, Sanaa; Philip, Charles-André; Yasmeen, Amber; Gotlieb, Walter H.

    2015-01-01

    Impairment of homologous recombination (HR) is found in close to 50 % of ovarian and breast cancer. Tumors with BRCA1 mutations show increased expression of the Insulin-like growth factor type 1 receptor (IGF-1R). We previously have shown that inhibition of IGF-1R results in growth inhibition and apoptosis of ovarian tumor cells. In the current study, we aimed to investigate the correlation between HR and sensitivity to IGF-1R inhibition. Further, we hypothesized that IGF-1R inhibition might sensitize HR proficient cancers to Poly ADP ribose polymerase (PARP) inhibitors. Using ovarian and breast cancer cellular models with known BRCA1 status, we evaluated their HR functionality by RAD51 foci formation assay. The 50 % lethal concentration (LC50) of Insulin-like growth factor type 1 receptor kinase inhibitor (IGF-1Rki) in these cells was assessed, and western immunoblotting was performed to determine the expression of proteins involved in the IGF-1R pathway. Moreover, IGF-1R inhibitors were added on HR proficient cell lines to assess mRNA and protein expression of RAD51 by qPCR and western blot. Also, we explored the interaction between RAD51 and Insulin receptor substance 1 (IRS-1) by immunoprecipitation. Next, combination effect of IGF-1R and PARP inhibitors was evaluated by clonogenic assay. Cells with mutated/methylated BRCA1 showed an impaired HR function, and had an overactivation of the IGF-1R pathway. These cells were more sensitive to IGF-1R inhibition compared to HR proficient cells. In addition, the IGF-IR inhibitor reduced RAD51 expression at mRNA and protein levels in HR proficient cells, and sensitized these cells to PARP inhibitor. Targeting IGF-1R might lead to improved personalized therapeutic approaches in cancer patients with HR deficiency. Targeting both PARP and IGF-1R might increase the clinical efficacy in HR deficient patients and increase the population of patients who may benefit from PARP inhibitors

  8. Radiosensitization by PARP inhibition to proton beam irradiation in cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Hirai, Takahisa [Department of Radiation Oncology, Juntendo University Faculty of Medicine, Bunkyo-ku, Tokyo (Japan); Division of Chemotherapy and Clinical Cancer Research, National Cancer Center Research Institute, Chuo-ku, Tokyo (Japan); Saito, Soichiro; Fujimori, Hiroaki [Division of Chemotherapy and Clinical Cancer Research, National Cancer Center Research Institute, Chuo-ku, Tokyo (Japan); Matsushita, Keiichiro; Nishio, Teiji [Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima-shi, Hiroshima (Japan); Okayasu, Ryuichi [International Open Laboratory, National Institute of Radiological Science, Chiba-shi, Chiba (Japan); Masutani, Mitsuko, E-mail: mmasutan@nagasaki-u.ac.jp [Division of Chemotherapy and Clinical Cancer Research, National Cancer Center Research Institute, Chuo-ku, Tokyo (Japan); Department of Frontier Life Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki (Japan)

    2016-09-09

    The poly(ADP-ribose) polymerase (PARP)-1 regulates DNA damage responses and promotes base excision repair. PARP inhibitors have been shown to enhance the cytotoxicity of ionizing radiation in various cancer cells and animal models. We have demonstrated that the PARP inhibitor (PARPi) AZD2281 is also an effective radiosensitizer for carbon-ion radiation; thus, we speculated that the PARPi could be applied to a wide therapeutic range of linear energy transfer (LET) radiation as a radiosensitizer. Institutes for biological experiments using proton beam are limited worldwide. This study was performed as a cooperative research at heavy ion medical accelerator in Chiba (HIMAC) in National Institute of Radiological Sciences. HIMAC can generate various ion beams; this enabled us to compare the radiosensitization effect of the PARPi on cells subjected to proton and carbon-ion beams from the same beam line. After physical optimization of proton beam irradiation, the radiosensitization effect of the PARPi was assessed in the human lung cancer cell line, A549, and the pancreatic cancer cell line, MIA PaCa-2. The effect of the PARPi, AZD2281, on radiosensitization to Bragg peak was more significant than that to entrance region. The PARPi increased the number of phosphorylated H2AX (γ-H2AX) foci and enhanced G2/M arrest after proton beam irradiation. This result supports our hypothesis that a PARPi could be applied to a wide therapeutic range of LET radiation by blocking the DNA repair response. - Highlights: • Effective radiosensitizers for particle radiation therapy have not been reported. • PARP inhibitor treatment radiosensitized after proton beam irradiation. • The sensitization at Bragg peak was greater than that at entrance region. • DSB induction and G2/M arrest is involved in the sensitization mechanism.

  9. 17-beta estradiol inhibits oxidative stress-induced accumulation of AIF into nucleolus and PARP1-dependent cell death via estrogen receptor alpha.

    Science.gov (United States)

    Batnasan, Enkhzaya; Wang, Ruoxi; Wen, Jitao; Ke, Yueshuang; Li, Xiaoxue; Bohio, Ameer Ali; Zeng, Xianlu; Huo, Hongliang; Han, Liping; Boldogh, Istvan; Ba, Xueqing

    2015-01-05

    Oxidative stress-induced DNA damage results in over-activation of poly(ADP-ribose) polymerase 1 (PARP1), leading to parthanatos, a newly discovered cell elimination pathway. Inhibition of PARP1-dependent cell death has shown to improve the outcome of diseases, including stroke, heart ischemia, and neurodegenerative diseases. In the present study we aimed to detect whether estrogen plays a protective role in inhibiting parthanatos. We utilized human mammary adenocarcinoma cells (MCF7) that abundantly express the estrogen receptor alpha and beta (ERα and ERβ). Parthanatos was induced by challenging the cells with hydrogen peroxide (H2O2). Microscopic imaging and molecular biological techniques, such as Western blot analysis and RNA interference, were performed. The results showed 17β estradiol (E2) protected MCF7 cells from PARP1-dependent cell death by decreasing protein PARylation, and AIF translocation into nuclei/nucleoli. Down-regulation of ERα expression by siRNA before E2 addition resulted in the failure of the E2-mediated inhibition of H2O2-induced protein PARylation and AIF nucleolar translocation. Together these data suggest that estrogen via its alpha-type receptor inhibits oxidative stress-induced, PARP1-dependent cell death. The present study provided us insight into how to apply hormone therapy in intervention of parthanatos-implicated ischemic and degenerative diseases. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  10. Olopatadine Inhibits Exocytosis in Rat Peritoneal Mast Cells by Counteracting Membrane Surface Deformation

    Directory of Open Access Journals (Sweden)

    Asuka Baba

    2015-01-01

    Full Text Available Backgroud/Aims: Besides its anti-allergic properties as a histamine receptor antagonist, olopatadine stabilizes mast cells by inhibiting the release of chemokines. Since olopatadine bears amphiphilic features and is preferentially partitioned into the lipid bilayers of the plasma membrane, it would induce some morphological changes in mast cells and thus affect the process of exocytosis. Methods: Employing the standard patch-clamp whole-cell recording technique, we examined the effects of olopatadine and other anti-allergic drugs on the membrane capacitance (Cm in rat peritoneal mast cells during exocytosis. Using confocal imaging of a water-soluble fluorescent dye, lucifer yellow, we also examined their effects on the deformation of the plasma membrane. Results: Low concentrations of olopatadine (1 or 10 µM did not significantly affect the GTP-γ-S-induced increase in the Cm. However, 100 µM and 1 mM olopatadine almost totally suppressed the increase in the Cm. Additionally, these doses completely washed out the trapping of the dye on the cell surface, indicating that olopatadine counteracted the membrane surface deformation induced by exocytosis. As shown by electron microscopy, olopatadine generated inward membrane bending in mast cells. Conclusion: This study provides electrophysiological evidence for the first time that olopatadine dose-dependently inhibits the process of exocytosis in rat peritoneal mast cells. Such mast cell stabilizing properties of olopatadine may be attributed to its counteracting effects on the plasma membrane deformation in degranulating mast cells.

  11. Counteracting ammonia inhibition during anaerobic digestion by recovery using submersible microbial desalination cell

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Angelidaki, Irini

    2015-01-01

    Ammonia inhibition is one of the most frequent and serious problems in biogas plants. In this study, a novel hybrid system consisting of a submersible microbial desalination cell (SMDC) and a continuous stirred tank reactor (CSTR) was developed for counteracting ammonia inhibition during anaerobic...... digestion (AD) with simultaneous in situ ammonia recovery and electricity production. The SMDC was powered by acetate in a buffer solution, while synthetic ammonia-rich wastewater was used as the feeding of the CSTR. Under continuous operation, ammonia recovery rate of 86 g-N/m2 /day and current density...... of 4.33 A/m2 were achieved at steady-state condition. As a result, 112% extra biogas was produced due to ammonia recovery by the SMDC. High-throughput sequencing showed that ammonia recovery had an impact on the microbial community structures in the SMDC and CSTR. Considering the additional economic...

  12. A Single Pair of Serotonergic Neurons Counteracts Serotonergic Inhibition of Ethanol Attraction in Drosophila.

    Science.gov (United States)

    Xu, Li; He, Jianzheng; Kaiser, Andrea; Gräber, Nikolas; Schläger, Laura; Ritze, Yvonne; Scholz, Henrike

    2016-01-01

    Attraction to ethanol is common in both flies and humans, but the neuromodulatory mechanisms underlying this innate attraction are not well understood. Here, we dissect the function of the key regulator of serotonin signaling-the serotonin transporter-in innate olfactory attraction to ethanol in Drosophila melanogaster. We generated a mutated version of the serotonin transporter that prolongs serotonin signaling in the synaptic cleft and is targeted via the Gal4 system to different sets of serotonergic neurons. We identified four serotonergic neurons that inhibit the olfactory attraction to ethanol and two additional neurons that counteract this inhibition by strengthening olfactory information. Our results reveal that compensation can occur on the circuit level and that serotonin has a bidirectional function in modulating the innate attraction to ethanol. Given the evolutionarily conserved nature of the serotonin transporter and serotonin, the bidirectional serotonergic mechanisms delineate a basic principle for how random behavior is switched into targeted approach behavior.

  13. PARP Inhibition Prevents Ethanol-Induced Neuroinflammatory Signaling and Neurodegeneration in Rat Adult-Age Brain Slice Cultures

    Science.gov (United States)

    Tajuddin, Nuzhath; Kim, Hee-Yong

    2018-01-01

    Using rat adult-age hippocampal-entorhinal cortical (HEC) slice cultures, we examined the role of poly [ADP-ribose] polymerase (PARP) in binge ethanol’s brain inflammatory and neurodegenerative mechanisms. Activated by DNA strand breaks, PARP (principally PARP1 in the brain) promotes DNA repair via poly [ADP-ribose] (PAR) products, but PARP overactivation triggers regulated neuronal necrosis (e.g., parthanatos). Previously, we found that brain PARP1 levels were upregulated by neurotoxic ethanol binges in adult rats and HEC slices, and PARP inhibitor PJ34 abrogated slice neurodegeneration. Binged HEC slices also exhibited increased Ca+2-dependent phospholipase A2 (PLA2) isoenzymes (cPLA2 IVA and sPLA2 IIA) that mobilize proinflammatory ω6 arachidonic acid (ARA). We now find in 4-day–binged HEC slice cultures (100 mM ethanol) that PARP1 elevations after two overnight binges precede PAR, cPLA2, and sPLA2 enhancements by 1 day and high-mobility group box-1 (HMGB1), an ethanol-responsive alarmin that augments proinflammatory cytokines via toll-like receptor-4 (TLR4), by 2 days. After verifying that PJ34 effectively blocks PARP activity (↑PAR), we demonstrated that, like PJ34, three other PARP inhibitors—olaparib, veliparib, and 4-aminobenzamide—provided neuroprotection from ethanol. Importantly, PJ34 and olaparib also prevented ethanol’s amplification of the PLA2 isoenzymes, and two PLA2 inhibitors were neuroprotective—thus coupling PARP to PLA2, with PLA2 activity promoting neurodegeneration. Also, PJ34 and olaparib blocked ethanol-induced HMGB1 elevations, linking brain PARP induction to TLR4 activation. The results provide evidence in adult brains that induction of PARP1 may mediate dual neuroinflammatory pathways (PLA2→phospholipid→ARA and HMGB1→TLR4→proinflammatory cytokines) that are complicit in binge ethanol-induced neurodegeneration. PMID:29339456

  14. ARTD1/PARP1 Negatively Regulates Glycolysis by Inhibiting Hexokinase 1 Independent of NAD+ Depletion

    Directory of Open Access Journals (Sweden)

    Elise Fouquerel

    2014-09-01

    Full Text Available ARTD1 (PARP1 is a key enzyme involved in DNA repair through the synthesis of poly(ADP-ribose (PAR in response to strand breaks, and it plays an important role in cell death following excessive DNA damage. ARTD1-induced cell death is associated with NAD+ depletion and ATP loss; however, the molecular mechanism of ARTD1-mediated energy collapse remains elusive. Using real-time metabolic measurements, we compared the effects of ARTD1 activation and direct NAD+ depletion. We found that ARTD1-mediated PAR synthesis, but not direct NAD+ depletion, resulted in a block to glycolysis and ATP loss. We then established a proteomics-based PAR interactome after DNA damage and identified hexokinase 1 (HK1 as a PAR binding protein. HK1 activity is suppressed following nuclear ARTD1 activation and binding by PAR. These findings help explain how prolonged activation of ARTD1 triggers energy collapse and cell death, revealing insight into the importance of nucleus-to-mitochondria communication via ARTD1 activation.

  15. Counteracting ammonia inhibition during anaerobic digestion by recovery using submersible microbial desalination cell.

    Science.gov (United States)

    Zhang, Yifeng; Angelidaki, Irini

    2015-07-01

    Ammonia inhibition is one of the most frequent and serious problems in biogas plants. In this study, a novel hybrid system consisting of a submersible microbial desalination cell (SMDC) and a continuous stirred tank reactor (CSTR) was developed for counteracting ammonia inhibition during anaerobic digestion (AD) with simultaneous in situ ammonia recovery and electricity production. The SMDC was powered by acetate in a buffer solution, while synthetic ammonia-rich wastewater was used as the feeding of the CSTR. Under continuous operation, ammonia recovery rate of 86 g-N/m(2) /day and current density of 4.33 A/m(2) were achieved at steady-state condition. As a result, 112% extra biogas was produced due to ammonia recovery by the SMDC. High-throughput sequencing showed that ammonia recovery had an impact on the microbial community structures in the SMDC and CSTR. Considering the additional economic benefits of biogas enhancement and possible wastewater treatment, the SMDC may represent a cost-effective and environmentally friendly method for waste resources recovery and biomethanation of ammonia-rich residues. © 2015 Wiley Periodicals, Inc.

  16. Structural Implications for Selective Targeting of PARPs.

    Science.gov (United States)

    Steffen, Jamin D; Brody, Jonathan R; Armen, Roger S; Pascal, John M

    2013-12-20

    Poly(ADP-ribose) polymerases (PARPs) are a family of enzymes that use NAD(+) as a substrate to synthesize polymers of ADP-ribose (PAR) as post-translational modifications of proteins. PARPs have important cellular roles that include preserving genomic integrity, telomere maintenance, transcriptional regulation, and cell fate determination. The diverse biological roles of PARPs have made them attractive therapeutic targets, which have fueled the pursuit of small molecule PARP inhibitors. The design of PARP inhibitors has matured over the past several years resulting in several lead candidates in clinical trials. PARP inhibitors are mainly used in clinical trials to treat cancer, particularly as sensitizing agents in combination with traditional chemotherapy to reduce side effects. An exciting aspect of PARP inhibitors is that they are also used to selectivity kill tumors with deficiencies in DNA repair proteins (e.g., BRCA1/2) through an approach termed "synthetic lethality." In the midst of the tremendous efforts that have brought PARP inhibitors to the forefront of modern chemotherapy, most clinically used PARP inhibitors bind to conserved regions that permits cross-selectivity with other PARPs containing homologous catalytic domains. Thus, the differences between therapeutic effects and adverse effects stemming from pan-PARP inhibition compared to selective inhibition are not well understood. In this review, we discuss current literature that has found ways to gain selectivity for one PARP over another. We furthermore provide insights into targeting other domains that make up PARPs, and how new classes of drugs that target these domains could provide a high degree of selectivity by affecting specific cellular functions. A clear understanding of the inhibition profiles of PARP inhibitors will not only enhance our understanding of the biology of individual PARPs, but may provide improved therapeutic options for patients.

  17. Evidence That the Microbiota Counteracts Male Outbreeding Strategy by Inhibiting Sexual Signaling in Females

    Directory of Open Access Journals (Sweden)

    Chloe Heys

    2018-03-01

    Full Text Available The microbiota is increasingly being recognized as having important impacts on many host biological processes. However, evidence of its effects on animal communication and breeding strategy is lacking. In this three-factorial study, we show that females were more willing to mate with related males, with relatedness likely being assessed through the microbiota. By contrast, male mating investment is concurrently determined by both the relatedness and microbiota status of the female. When the microbiota in female Drosophila melanogaster is altered by an antibiotic, male investment in sperm number increased when mating with unrelated females compared to related ones. Contrastingly, the presence of an intact microbiota in females canceled this male outbreeding strategy. As a consequence, the microbiota, when intact, decreased the fitness of the mating couple. Furthermore, we showed that female sexual signaling (cuticular hydrocarbons, with regards to kin recognition, significantly interacts with microbiota. Interestingly, the interaction is significant for hydrocarbons expressed by both sexes, but not for female-specific compounds. Taken together, our results suggest that microbiota can influence kin recognition by disfavoring male outbreeding strategies, likely by inhibiting key olfactory sexual signaling. This represents the first evidence of a host outbreeding strategy counteracted by their microbiota.

  18. Counteracting ammonia inhibition in anaerobic digestion by removal with a hollow fiber membrane contactor.

    Science.gov (United States)

    Lauterböck, B; Ortner, M; Haider, R; Fuchs, W

    2012-10-01

    The aim of the current study was to investigate the feasibility of membrane contactors for continuous ammonia (NH₃-N) removal in an anaerobic digestion process and to counteract ammonia inhibition. Two laboratory anaerobic digesters were fed slaughterhouse wastes with ammonium (NH₄⁺) concentrations ranging from 6 to 7.4 g/L. One reactor was used as reference reactor without any ammonia removal. In the second reactor, a hollow fiber membrane contactor module was used for continuous ammonia removal. The hollow fiber membranes were directly submerged into the digestate of the anaerobic reactor. Sulfuric acid was circulated in the lumen as an adsorbent solution. Using this set up, the NH₄⁺-N concentration in the membrane reactor was significantly reduced. Moreover the extraction of ammonia lowered the pH by 0.2 units. In combination that led to a lowering of the free NH₃-N concentration by about 70%. Ammonia inhibition in the reference reactor was observed when the concentration exceeded 6 g/L NH₄⁺-N or 1-1.2 g/L NH₃-N. In contrast, in the membrane reactor the volatile fatty acid concentration, an indicator for process stability, was much lower and a higher gas yield and better degradation was observed. The chosen approach offers an appealing technology to remove ammonia directly from media having high concentrations of solids and it can help to improve process efficiency in anaerobic digestion of ammonia rich substrates. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Combinations of PARP Inhibitors with Temozolomide Drive PARP1 Trapping and Apoptosis in Ewing's Sarcoma.

    Science.gov (United States)

    Gill, Sonja J; Travers, Jon; Pshenichnaya, Irina; Kogera, Fiona A; Barthorpe, Syd; Mironenko, Tatiana; Richardson, Laura; Benes, Cyril H; Stratton, Michael R; McDermott, Ultan; Jackson, Stephen P; Garnett, Mathew J

    2015-01-01

    Ewing's sarcoma is a malignant pediatric bone tumor with a poor prognosis for patients with metastatic or recurrent disease. Ewing's sarcoma cells are acutely hypersensitive to poly (ADP-ribose) polymerase (PARP) inhibition and this is being evaluated in clinical trials, although the mechanism of hypersensitivity has not been directly addressed. PARP inhibitors have efficacy in tumors with BRCA1/2 mutations, which confer deficiency in DNA double-strand break (DSB) repair by homologous recombination (HR). This drives dependence on PARP1/2 due to their function in DNA single-strand break (SSB) repair. PARP inhibitors are also cytotoxic through inhibiting PARP1/2 auto-PARylation, blocking PARP1/2 release from substrate DNA. Here, we show that PARP inhibitor sensitivity in Ewing's sarcoma cells is not through an apparent defect in DNA repair by HR, but through hypersensitivity to trapped PARP1-DNA complexes. This drives accumulation of DNA damage during replication, ultimately leading to apoptosis. We also show that the activity of PARP inhibitors is potentiated by temozolomide in Ewing's sarcoma cells and is associated with enhanced trapping of PARP1-DNA complexes. Furthermore, through mining of large-scale drug sensitivity datasets, we identify a subset of glioma, neuroblastoma and melanoma cell lines as hypersensitive to the combination of temozolomide and PARP inhibition, potentially identifying new avenues for therapeutic intervention. These data provide insights into the anti-cancer activity of PARP inhibitors with implications for the design of treatment for Ewing's sarcoma patients with PARP inhibitors.

  20. NSs protein of Schmallenberg virus counteracts the antiviral response of the cell by inhibiting its transcriptional machinery.

    Science.gov (United States)

    Barry, Gerald; Varela, Mariana; Ratinier, Maxime; Blomström, Anne-Lie; Caporale, Marco; Seehusen, Frauke; Hahn, Kerstin; Schnettler, Esther; Baumgärtner, Wolfgang; Kohl, Alain; Palmarini, Massimo

    2014-08-01

    Bunyaviruses have evolved a variety of strategies to counteract the antiviral defence systems of mammalian cells. Here we show that the NSs protein of Schmallenberg virus (SBV) induces the degradation of the RPB1 subunit of RNA polymerase II and consequently inhibits global cellular protein synthesis and the antiviral response. In addition, we show that the SBV NSs protein enhances apoptosis in vitro and possibly in vivo, suggesting that this protein could be involved in SBV pathogenesis in different ways. © 2014 The Authors.

  1. The neuroprotective effect of nicotine in Parkinson’s disease models is associated with inhibiting PARP-1 and caspase-3 cleavage

    Directory of Open Access Journals (Sweden)

    Justin Y.D. Lu

    2017-10-01

    Full Text Available Clinical evidence points to neuroprotective effects of smoking in Parkinson’s disease (PD, but the molecular mechanisms remain unclear. We investigated the pharmacological pathways involved in these neuroprotective effects, which could provide novel ideas for developing targeted neuroprotective treatments for PD. We used the ETC complex I inhibitor methylpyridinium ion (MPP+ to induce cell death in SH-SY5Y cells as a cellular model for PD and found that nicotine inhibits cell death. Using choline as a nicotinic acetylcholine receptor (nAChR agonist, we found that nAChR stimulation was sufficient to protect SH-SY5Y cells against cell death from MPP+. Blocking α7 nAChR with methyllycaconitine (MLA prevented the protective effects of nicotine, demonstrating that these receptors are necessary for the neuroprotective effects of nicotine. The neuroprotective effect of nicotine involves other pathways relevant to PD. Cleaved Poly (ADP-ribose polymerase-1 (PARP-1 and cleaved caspase-3 were decreased by nicotine in 6-hydroxydopamine (6-OHDA lesioned mice and in MPP+-treated SH-SY5Y cells. In conclusion, our data indicate that nicotine likely exerts neuroprotective effects in PD through the α7 nAChR and downstream pathways including PARP-1 and caspase-3. This knowledge could be pursued in future research to develop neuroprotective treatments for PD.

  2. Radiosensitivity modulating factors: Role of PARP-1, PARP-2 and Cdk5 proteins and chromatin implication

    International Nuclear Information System (INIS)

    Boudra, M.T.

    2011-12-01

    The post-translational modifications of DNA repair proteins and histone remodeling factors by poly(ADP-ribose)ylation and phosphorylation are essential for the maintenance of DNA integrity and chromatin structure, and in particular in response to DNA damaging produced by ionizing radiation (IR). Amongst the proteins implicated in these two processes are the poly(ADP-ribose) polymerase -1 (PARP-1) and PARP-2, and the cyclin-dependent kinase Cdk5: PARP-1 and 2 are involved in DNA single strand break (SSB) repair (SSBR) and Cdk5 depletion has been linked with increased cell sensitivity to PARP inhibition. We have shown by using HeLa cells stably depleted for either CdK5 or PARP-2, that the recruitment profile of PARP-1 and XRCC-1, two proteins involved in the short-patch (SP) SSBR sub-pathway, to DNA damage sites is sub-maximal and that of PCNA, a protein involved in the long-patch (LP) repair pathway, is increased in the absence of Cdk5 and decreased in the absence of PARP-2 suggesting that both Cdk5 and PARP-2 are involved in both SSBR sub-pathways. PARP-2 and Cdk5 also impact on the poly(ADP-ribose) levels in cells as in the absence of Cdk5 a hyper-activation of PARP-1 was found and in the absence of PARP-2 a reduction in poly(ADP-ribose) glyco-hydrolase (PARG) activity was seen. However, in spite of these changes no impact on the repair of SSBs induced by IR was seen in either the Cdk5 or PARP-2 depleted cells (Cdk5 KD or PARP-2 KD cells) but, interestingly, increased radiation sensitivity in terms of cell killing was noted in the Cdk5 depleted cells. We also found that Cdk5, PARP-2 and PARG were all implicated in the regulation of the recruitment and the dissociation of the chromatin-remodeling factor ALC1 from DNA damage sites suggesting a role for these three proteins in changes in chromatin structure after DNA photo-damage. These results, taken together with the observation that PARP-1 recruitment is sub-optimal in both Cdk5 KD and PARP-2 KD cells, show that

  3. Antiviral Inhibition of Enveloped Virus Release by Tetherin/BST-2: Action and Counteraction

    Directory of Open Access Journals (Sweden)

    Stuart J. D. Neil

    2011-05-01

    Full Text Available Tetherin (BST2/CD317 has been recently recognized as a potent interferon-induced antiviral molecule that inhibits the release of diverse mammalian enveloped virus particles from infected cells. By targeting an immutable structure common to all these viruses, the virion membrane, evasion of this antiviral mechanism has necessitated the development of specific countermeasures that directly inhibit tetherin activity. Here we review our current understanding of the molecular basis of tetherin’s mode of action, the viral countermeasures that antagonize it, and how virus/tetherin interactions may affect viral transmission and pathogenicity.

  4. Growth of antarctic cyanobacteria under ultraviolet radiation: UVA counteracts UVB inhibition

    International Nuclear Information System (INIS)

    Quesada, A.; Mouget, J.L.; Vincent, W.F.

    1995-01-01

    A mat-forming cyanobacterium (Phormidium murayi West and West) isolated from an ice-shelf pond in Antarctica was grown under white light combined with a range of UVA and UVB irradiance. The 4-day growth rate decreased under increasing ultraviolet (UV) radiation, with a ninefold greater response to UVB relative to UVA. In vivo absorbance spectra showed that UVA and to a greater extent UVB caused a decrease in phycocyanin/chlorophyll a and an increase in carotenoids/chlorophyll a. The phycocyanin/chlorophyll a ratio was closely and positively correlated to the UVB-inhibited growth rate. Under fixed spectral gradients of UV radiation, the growth inhibition effect was dominated by UVB. However, at specific UVB irradiances the inhibition of growth depended on the ratio of UVB to UVA, and growth rates increased linearly with increasing UVA. These results are consistent with the view that UVB inhibition represents the balance between damage and repair processes that are each controlled by separate wavebands. They also underscore the need to consider UV spectral balance in laboratory and field assays of UVB toxicity. 49 refs., 6 figs

  5. Notch inhibition counteracts Paneth cell death in absence of caspase-8.

    Science.gov (United States)

    Jeon, M K; Kaemmerer, E; Schneider, U; Schiffer, M; Klaus, C; Hennings, J; Clahsen, T; Ackerstaff, T; Niggemann, M; Schippers, A; Longerich, T; Sellge, G; Trautwein, C; Wagner, N; Liedtke, C; Gassler, N

    2018-05-16

    Opposing activities of Notch and Wnt signaling regulate mucosal barrier homeostasis and differentiation of intestinal epithelial cells. Specifically, Wnt activity is essential for differentiation of secretory cells including Wnt3-producing Paneth cells, whereas Notch signaling strongly promotes generation of absorptive cells. Loss of caspase-8 in intestinal epithelium (casp8 ∆int ) is associated with fulminant epithelial necroptosis, severe Paneth cell death, secondary intestinal inflammation, and an increase in Notch activity. Here, we found that pharmacological Notch inhibition with dibenzazepine (DBZ) is able to essentially rescue the loss of Paneth cells, deescalate the inflammatory phenotype, and reduce intestinal permeability in casp8 ∆int mice. The secretory cell metaplasia in DBZ-treated casp8 ∆int animals is proliferative, indicating for Notch activities partially insensitive to gamma-secretase inhibition in a casp8 ∆int background. Our data suggest that casp8 acts in the intestinal Notch network.

  6. Protective Effects of Chlorella-Derived Peptide Against UVC-Induced Cytotoxicity through Inhibition of Caspase-3 Activity and Reduction of the Expression of Phosphorylated FADD and Cleaved PARP-1 in Skin Fibroblasts

    Directory of Open Access Journals (Sweden)

    Jong Yuh Cherng

    2012-08-01

    Full Text Available UVC irradiation induces oxidative stress and leads to cell death through an apoptotic pathway. This apoptosis is caused by activation of caspase-3 and formation of poly(ADP-ribose polymerase-1 (PARP-1. In this study, the underlying mechanisms of Chlorella derived peptide (CDP activity against UVC-induced cytotoxicity were investigated. Human skin fibroblasts were treated with CDP, vitamin C, or vitamin E after UVC irradiation for a total energy of 15 J/cm2. After the UVC exposure, cell proliferation and caspase-3 activity were measured at 12, 24, 48, and 72 h later. Expression of phosphorylated FADD and cleaved PARP-1 were measured 16 h later. DNA damage (expressed as pyrimidine (6-4 pyrimidone photoproducts DNA concentration and fragmentation assay were performed 24 h after the UVC exposure. Results showed that UVC irradiation induced cytotoxicity in all groups except those treated with CDP. The caspase-3 activity in CDP-treated cells was inhibited from 12 h onward. Expression of phosphorylated FADD and cleaved PARP-1 were also reduced in CDP-treated cells. Moreover, UVC-induced DNA damage and fragmentation were also prevented by the CDP treatment. This study shows that treatment of CDP provides protective effects against UVC-induced cytotoxicity through the inhibition of caspase-3 activity and the reduction of phosphorylated FADD and cleaved PARP-1 expression.

  7. Pharmacological Inhibition of PKCθ Counteracts Muscle Disease in a Mouse Model of Duchenne Muscular Dystrophy.

    Science.gov (United States)

    Marrocco, V; Fiore, P; Benedetti, A; Pisu, S; Rizzuto, E; Musarò, A; Madaro, L; Lozanoska-Ochser, B; Bouché, M

    2017-02-01

    Inflammation plays a considerable role in the progression of Duchenne Muscular Dystrophy (DMD), a severe muscle disease caused by a mutation in the dystrophin gene. We previously showed that genetic ablation of Protein Kinase C θ (PKCθ) in mdx, the mouse model of DMD, improves muscle healing and regeneration, preventing massive inflammation. To establish whether pharmacological targeting of PKCθ in DMD can be proposed as a therapeutic option, in this study we treated young mdx mice with the PKCθ inhibitor Compound 20 (C20). We show that C20 treatment led to a significant reduction in muscle damage associated with reduced immune cells infiltration, reduced inflammatory pathways activation, and maintained muscle regeneration. Importantly, C20 treatment is efficient in recovering muscle performance in mdx mice, by preserving muscle integrity. Together, these results provide proof of principle that pharmacological inhibition of PKCθ in DMD can be considered an attractive strategy to modulate immune response and prevent the progression of the disease. Duchenne muscular dystrophy (DMD) is a severe muscle disease affecting 1:3500 male births. DMD is caused by a mutation in dystrophin gene, coding for a protein required for skeletal and cardiac muscle integrity. Lack of a functional dystrophin is primarily responsible for the muscle eccentric contraction-induced muscle damage, observed in dystrophic muscle. However, inflammation plays a considerable role in the progression of DMD. Glucocorticoids, which have anti-inflammatory properties, are being used to treat DMD with some success; however, long term treatment with these drugs induces muscle atrophy and wasting, outweighing their benefit. The identification of specific targets for anti-inflammatory therapies is one of the ongoing therapeutic options. Although blunting inflammation would not be a "cure" for the disease, the emerging clue is that multiple strategies, addressing different aspects of the pathology

  8. IDH1/2 Mutations Sensitize Acute Myeloid Leukemia to PARP Inhibition and This Is Reversed by IDH1/2-Mutant Inhibitors.

    Science.gov (United States)

    Molenaar, Remco J; Radivoyevitch, Tomas; Nagata, Yasunobu; Khurshed, Mohammed; Przychodzen, Bartolomiej; Makishima, Hideki; Xu, Mingjiang; Bleeker, Fonnet E; Wilmink, Johanna W; Carraway, Hetty E; Mukherjee, Sudipto; Sekeres, Mikkael A; van Noorden, Cornelis J F; Maciejewski, Jaroslaw P

    2018-04-01

    Purpose: Somatic mutations in IDH1/2 occur in approximately 20% of patients with myeloid neoplasms, including acute myeloid leukemia (AML). IDH1/2 MUT enzymes produce D -2-hydroxyglutarate ( D 2HG), which associates with increased DNA damage and improved responses to chemo/radiotherapy and PARP inhibitors in solid tumor cells. Whether this also holds true for IDH1/2 MUT AML is not known. Experimental Design: Well-characterized primary IDH1 MUT , IDH2 MUT , and IDH1/2 WT AML cells were analyzed for DNA damage and responses to daunorubicin, ionizing radiation, and PARP inhibitors. Results: IDH1/2 MUT caused increased DNA damage and sensitization to daunorubicin, irradiation, and the PARP inhibitors olaparib and talazoparib in AML cells. IDH1/2 MUT inhibitors protected against these treatments. Combined treatment with a PARP inhibitor and daunorubicin had an additive effect on the killing of IDH1/2 MUT AML cells. We provide evidence that the therapy sensitivity of IDH1/2 MUT cells was caused by D 2HG-mediated downregulation of expression of the DNA damage response gene ATM and not by altered redox responses due to metabolic alterations in IDH1/2 MUT cells. Conclusions: IDH1/2 MUT AML cells are sensitive to PARP inhibitors as monotherapy but especially when combined with a DNA-damaging agent, such as daunorubicin, whereas concomitant administration of IDH1/2 MUT inhibitors during cytotoxic therapy decrease the efficacy of both agents in IDH1/2 MUT AML. These results advocate in favor of clinical trials of PARP inhibitors either or not in combination with daunorubicin in IDH1/2 MUT AML. Clin Cancer Res; 24(7); 1705-15. ©2018 AACR . ©2018 American Association for Cancer Research.

  9. Cardiovascular Protective Effect of Metformin and Telmisartan: Reduction of PARP1 Activity via the AMPK-PARP1 Cascade.

    Directory of Open Access Journals (Sweden)

    Fenqing Shang

    Full Text Available Hyperglycemia and hypertension impair endothelial function in part through oxidative stress-activated poly (ADP-ribose polymerase 1 (PARP1. Biguanides and angiotensin II receptor blockers (ARBs such as metformin and telmisartan have a vascular protective effect. We used cultured vascular endothelial cells (ECs, diabetic and hypertensive rodent models, and AMPKα2-knockout mice to investigate whether metformin and telmisartan have a beneficial effect on the endothelium via AMP-activated protein kinase (AMPK phosphorylation of PARP1 and thus inhibition of PARP1 activity. The results showed that metformin and telmisartan, but not glipizide and metoprolol, activated AMPK, which phosphorylated PARP1 Ser-177 in cultured ECs and the vascular wall of rodent models. Experiments using phosphorylated/de-phosphorylated PARP1 mutants show that AMPK phosphorylation of PARP1 leads to decreased PARP1 activity and attenuated protein poly(ADP-ribosylation (PARylation, but increased endothelial nitric oxide synthase (eNOS activity and silent mating type information regulation 2 homolog 1 (SIRT1 expression. Taken together, the data presented here suggest biguanides and ARBs have a beneficial effect on the vasculature by the cascade of AMPK phosphorylation of PARP1 to inhibit PARP1 activity and protein PARylation in ECs, thereby mitigating endothelial dysfunction.

  10. The BRCA1-Δ11q Alternative Splice Isoform Bypasses Germline Mutations and Promotes Therapeutic Resistance to PARP Inhibition and Cisplatin

    DEFF Research Database (Denmark)

    Wang, Yifan; Bernhardy, Andrea J; Cruz, Cristina

    2016-01-01

    Breast and ovarian cancer patients harboring BRCA1/2 germline mutations have clinically benefitted from therapy with PARP inhibitor (PARPi) or platinum compounds, but acquired resistance limits clinical impact. In this study, we investigated the impact of mutations on BRCA1 isoform expression and...

  11. The NAD+/PARP1/SIRT1 Axis in Aging.

    Science.gov (United States)

    Mendelsohn, Andrew R; Larrick, James W

    2017-06-01

    NAD+ levels decline with age in diverse animals from Caenorhabditis elegans to mice. Raising NAD+ levels by dietary supplementation with NAD+ precursors, nicotinamide riboside (NR) or nicotinamide mononucleotide (NMN), improves mitochondrial function and muscle and neural and melanocyte stem cell function in mice, as well as increases murine life span. Decreased NAD+ levels with age reduce SIRT1 function and reduce the mitochondrial unfolded protein response, which can be overcome by NR supplementation. Decreased NAD+ levels cause NAD+-binding protein DBC1 to form a complex with PARP1, inhibiting poly(adenosine diphosphate-ribose) polymerase (PARP) catalytic activity. Old mice have increased amounts of DBC1-PARP1 complexes, lower PARP activity, increased DNA damage, and reduced nonhomologous end joining and homologous recombination repair. DBC1-PARP1 complexes in old mice can be broken by increasing NAD+ levels through treatment with NMN, reducing DNA damage and restoring PARP activity to youthful levels. The mechanism of declining NAD+ levels and its fundamental importance to aging are yet to be elucidated. There is a correlation of PARP activity with mammalian life span that suggests that NAD+/SIRT1/PARP1 may be more significant than the modest effects on life span observed for NR supplementation in old mice. The NAD+/PARP1/SIRT1 axis may link NAD+ levels and DNA damage with the apparent epigenomic DNA methylation clocks that have been described.

  12. PARP-1 and PARP-2 activity in cancer-induced cachexia: potential therapeutic implications.

    Science.gov (United States)

    Barreiro, Esther; Gea, Joaquim

    2018-01-26

    Skeletal muscle dysfunction and mass loss is a characteristic feature in patients with chronic diseases including cancer and acute conditions such as critical illness. Maintenance of an adequate muscle mass is crucial for the patients' prognosis irrespective of the underlying condition. Moreover, aging-related sarcopenia may further aggravate the muscle wasting process associated with chronic diseases and cancer. Poly(adenosine diphosphate-ribose) polymerase (PARP) activation has been demonstrated to contribute to the pathophysiology of muscle mass loss and dysfunction in animal models of cancer-induced cachexia. Genetic inhibition of PARP activity attenuated the deleterious effects seen on depleted muscles in mouse models of oncologic cachexia. In the present minireview the mechanisms whereby PARP activity inhibition may improve muscle mass and performance in models of cancer-induced cachexia are discussed. Specifically, the beneficial effects of inhibition of PARP activity on attenuation of increased oxidative stress, protein catabolism, poor muscle anabolism and mitochondrial content and epigenetic modulation of muscle phenotype are reviewed in this article. Finally, the potential therapeutic strategies of pharmacological PARP activity inhibition for the treatment of cancer-induced cachexia are also being described in this review.

  13. Parp-1 genetic ablation in Ela-myc mice unveils novel roles for Parp-1 in pancreatic cancer.

    Science.gov (United States)

    Martínez-Bosch, Neus; Iglesias, Mar; Munné-Collado, Jessica; Martínez-Cáceres, Carlos; Moreno, Mireia; Guerra, Carmen; Yélamos, Jose; Navarro, Pilar

    2014-10-01

    Pancreatic cancer has a dismal prognosis and is currently the fourth leading cause of cancer-related death in developed countries. The inhibition of poly(ADP-ribose) polymerase-1 (Parp-1), the major protein responsible for poly(ADP-ribosy)lation in response to DNA damage, has emerged as a promising treatment for several tumour types. Here we aimed to elucidate the involvement of Parp-1 in pancreatic tumour progression. We assessed Parp-1 protein expression in normal, preneoplastic and pancreatic tumour samples from humans and from K-Ras- and c-myc-driven mouse models of pancreatic cancer. Parp-1 was highly expressed in acinar cells in normal and cancer tissues. In contrast, ductal cells expressed very low or undetectable levels of this protein, both in a normal and in a tumour context. The Parp-1 expression pattern was similar in human and mouse samples, thereby validating the use of animal models for further studies. To determine the in vivo effects of Parp-1 depletion on pancreatic cancer progression, Ela-myc-driven pancreatic tumour development was analysed in a Parp-1 knock-out background. Loss of Parp-1 resulted in increased tumour necrosis and decreased proliferation, apoptosis and angiogenesis. Interestingly, Ela-myc:Parp-1(-/-) mice displayed fewer ductal tumours than their Ela-myc:Parp-1(+/+) counterparts, suggesting that Parp-1 participates in promoting acinar-to-ductal metaplasia, a key event in pancreatic cancer initiation. Moreover, impaired macrophage recruitment can be responsible for the ADM blockade found in the Ela-myc:Parp-1(-/-) mice. Finally, molecular analysis revealed that Parp-1 modulates ADM downstream of the Stat3-MMP7 axis and is also involved in transcriptional up-regulation of the MDM2, VEGFR1 and MMP28 cancer-related genes. In conclusion, the expression pattern of Parp-1 in normal and cancer tissue and the in vivo functional effects of Parp-1 depletion point to a novel role for this protein in pancreatic carcinogenesis and shed light

  14. Structural Basis for Potency and Promiscuity in Poly(ADP-ribose) Polymerase (PARP) and Tankyrase Inhibitors.

    Science.gov (United States)

    Thorsell, Ann-Gerd; Ekblad, Torun; Karlberg, Tobias; Löw, Mirjam; Pinto, Ana Filipa; Trésaugues, Lionel; Moche, Martin; Cohen, Michael S; Schüler, Herwig

    2017-02-23

    Selective inhibitors could help unveil the mechanisms by which inhibition of poly(ADP-ribose) polymerases (PARPs) elicits clinical benefits in cancer therapy. We profiled 10 clinical PARP inhibitors and commonly used research tools for their inhibition of multiple PARP enzymes. We also determined crystal structures of these compounds bound to PARP1 or PARP2. Veliparib and niraparib are selective inhibitors of PARP1 and PARP2; olaparib, rucaparib, and talazoparib are more potent inhibitors of PARP1 but are less selective. PJ34 and UPF1069 are broad PARP inhibitors; PJ34 inserts a flexible moiety into hydrophobic subpockets in various ADP-ribosyltransferases. XAV939 is a promiscuous tankyrase inhibitor and a potent inhibitor of PARP1 in vitro and in cells, whereas IWR1 and AZ-6102 are tankyrase selective. Our biochemical and structural analysis of PARP inhibitor potencies establishes a molecular basis for either selectivity or promiscuity and provides a benchmark for experimental design in assessment of PARP inhibitor effects.

  15. Inhibition of glucose turnover by 3-bromopyruvate counteracts pancreatic cancer stem cell features and sensitizes cells to gemcitabine.

    Science.gov (United States)

    Isayev, Orkhan; Rausch, Vanessa; Bauer, Nathalie; Liu, Li; Fan, Pei; Zhang, Yiyao; Gladkich, Jury; Nwaeburu, Clifford C; Mattern, Jürgen; Mollenhauer, Martin; Rückert, Felix; Zach, Sebastian; Haberkorn, Uwe; Gross, Wolfgang; Schönsiegel, Frank; Bazhin, Alexandr V; Herr, Ingrid

    2014-07-15

    According to the cancer stem cell (CSC) hypothesis, the aggressive growth and early metastasis of pancreatic ductal adenocarcinoma (PDA) is due to the activity of CSCs, which are not targeted by current therapies. Otto Warburg suggested that the growth of cancer cells is driven by a high glucose metabolism. Here, we investigated whether glycolysis inhibition targets CSCs and thus may enhance therapeutic efficacy. Four established and 3 primary PDA cell lines, non-malignant cells, and 3 patient-tumor-derived CSC-enriched spheroidal cultures were analyzed by glucose turnover measurements, MTT and ATP assays, flow cytometry of ALDH1 activity and annexin positivity, colony and spheroid formation, western blotting, electrophoretic mobility shift assay, xenotransplantation, and immunohistochemistry. The effect of siRNA-mediated inhibition of LDH-A and LDH-B was also investigated. The PDA cells exhibited a high glucose metabolism, and glucose withdrawal or LDH inhibition by siRNA prevented growth and colony formation. Treatment with the anti-glycolytic agent 3-bromopyruvate almost completely blocked cell viability, self-renewal potential, NF-κB binding activity, and stem cell-related signaling and reverted gemcitabine resistance. 3-bromopyruvate was less effective in weakly malignant PDA cells and did not affect non-malignant cells, predicting minimal side effects. 3-bromopyruvate inhibited in vivo tumor engraftment and growth on chicken eggs and mice and enhanced the efficacy of gemcitabine by influencing the expression of markers of proliferation, apoptosis, self-renewal, and metastasis. Most importantly, primary CSC-enriched spheroidal cultures were eliminated by 3-bromopyruvate. These findings propose that CSCs may be specifically dependent on a high glucose turnover and suggest 3-bromopyruvate for therapeutic intervention.

  16. Inhibition of glucose turnover by 3-bromopyruvate counteracts pancreatic cancer stem cell features and sensitizes cells to gemcitabine

    OpenAIRE

    Isayev, Orkhan; Rausch, Vanessa; Bauer, Nathalie; Liu, Li; Fan, Pei; Zhang, Yiyao; Gladkich, Jury; Nwaeburu, Clifford C.; Mattern, Jürgen; Mollenhauer, Martin; Rückert, Felix; Zach, Sebastian; Haberkorn, Uwe; Gross, Wolfgang; Schönsiegel, Frank

    2014-01-01

    According to the cancer stem cell (CSC) hypothesis, the aggressive growth and early metastasis of pancreatic ductal adenocarcinoma (PDA) is due to the activity of CSCs, which are not targeted by current therapies. Otto Warburg suggested that the growth of cancer cells is driven by a high glucose metabolism. Here, we investigated whether glycolysis inhibition targets CSCs and thus may enhance therapeutic efficacy. Four established and 3 primary PDA cell lines, non-malignant cells, and 3 patien...

  17. Dihydroartemisinin counteracts fibrotic portal hypertension via farnesoid X receptor-dependent inhibition of hepatic stellate cell contraction.

    Science.gov (United States)

    Xu, Wenxuan; Lu, Chunfeng; Zhang, Feng; Shao, Jiangjuan; Yao, Shunyu; Zheng, Shizhong

    2017-01-01

    Portal hypertension is a frequent pathological symptom occurring especially in hepatic fibrosis and cirrhosis. Current paradigms indicate that inhibition of hepatic stellate cell (HSC) activation and contraction is anticipated to be an attractive therapeutic strategy, because activated HSC dominantly facilitates an increase in intrahepatic vein pressure through secreting extracellular matrix and contracting. Our previous in vitro study indicated that dihydroartemisinin (DHA) inhibited contractility of cultured HSC by activating intracellular farnesoid X receptor (FXR). However, the effect of DHA on fibrosis-related portal hypertension still requires clarification. In this study, gain- and loss-of-function models of FXR in HSC were established to investigate the mechanisms underlying DHA protection against chronic CCl 4 -caused hepatic fibrosis and portal hypertension. Immunofluorescence staining visually showed a decrease in FXR expression in CCl 4 -administrated rat HSC but an increase in that in DHA-treated rat HSC. Serum diagnostics and morphological analyses consistently indicated that DHA exhibited hepatoprotective effects on CCl 4 -induced liver injury. DHA also reduced CCl 4 -caused inflammatory mediator expression and inflammatory cell infiltration. These improvements were further enhanced by INT-747 but weakened by Z-guggulsterone. Noteworthily, DHA, analogous to INT-747, significantly lowered portal vein pressure and suppressed fibrogenesis. Experiments on mice using FXR shRNA lentivirus consolidated the results above. Mechanistically, inhibition of HSC activation and contraction was found as a cellular basis for DHA to relieve portal hypertension. These findings demonstrated that DHA attenuated portal hypertension in fibrotic rodents possibly by targeting HSC contraction via a FXR activation-dependent mechanism. FXR could be a target molecule for reducing portal hypertension during hepatic fibrosis. © 2016 Federation of European Biochemical Societies.

  18. PARP-1 cleavage fragments: signatures of cell-death proteases in neurodegeneration

    Directory of Open Access Journals (Sweden)

    Alexander Jonathan S

    2010-12-01

    Full Text Available Abstract The normal function of poly (ADP-ribose polymerase-1 (PARP-1 is the routine repair of DNA damage by adding poly (ADP ribose polymers in response to a variety of cellular stresses. Recently, it has become widely appreciated that PARP-1 also participates in diverse physiological and pathological functions from cell survival to several forms of cell death and has been implicated in gene transcription, immune responses, inflammation, learning, memory, synaptic functions, angiogenesis and aging. In the CNS, PARP inhibition attenuates injury in pathologies like cerebral ischemia, trauma and excitotoxicity demonstrating a central role of PARP-1 in these pathologies. PARP-1 is also a preferred substrate for several 'suicidal' proteases and the proteolytic action of suicidal proteases (caspases, calpains, cathepsins, granzymes and matrix metalloproteinases (MMPs on PARP-1 produces several specific proteolytic cleavage fragments with different molecular weights. These PARP-1 signature fragments are recognized biomarkers for specific patterns of protease activity in unique cell death programs. This review focuses on specific suicidal proteases active towards PARP-1 to generate signature PARP-1 fragments that can identify key proteases and particular forms of cell death involved in pathophysiology. The roles played by some of the PARP-1 fragments and their associated binding partners in the control of different forms of cell death are also discussed.

  19. PRC2 inhibition counteracts the culture-associated loss of engraftment potential of human cord blood-derived hematopoietic stem and progenitor cells.

    Science.gov (United States)

    Varagnolo, Linda; Lin, Qiong; Obier, Nadine; Plass, Christoph; Dietl, Johannes; Zenke, Martin; Claus, Rainer; Müller, Albrecht M

    2015-07-22

    Cord blood hematopoietic stem cells (CB-HSCs) are an outstanding source for transplantation approaches. However, the amount of cells per donor is limited and culture expansion of CB-HSCs is accompanied by a loss of engraftment potential. In order to analyze the molecular mechanisms leading to this impaired potential we profiled global and local epigenotypes during the expansion of human CB hematopoietic stem and progenitor cells (HPSCs). Human CB-derived CD34+ cells were cultured in serum-free medium together with SCF, TPO, FGF, with or without Igfbp2 and Angptl5 (STF/STFIA cocktails). As compared to the STF cocktail, the STFIA cocktail maintains in vivo repopulation capacity of cultured CD34+ cells. Upon expansion, CD34+ cells genome-wide remodel their epigenotype and depending on the cytokine cocktail, cells show different H3K4me3 and H3K27me3 levels. Expanding cells without Igfbp2 and Angptl5 leads to higher global H3K27me3 levels. ChIPseq analyses reveal a cytokine cocktail-dependent redistribution of H3K27me3 profiles. Inhibition of the PRC2 component EZH2 counteracts the culture-associated loss of NOD scid gamma (NSG) engraftment potential. Collectively, our data reveal chromatin dynamics that underlie the culture-associated loss of engraftment potential. We identify PRC2 component EZH2 as being involved in the loss of engraftment potential during the in vitro expansion of HPSCs.

  20. Effects of PARP-1 Deficiency on Th1 and Th2 Cell Differentiation

    Directory of Open Access Journals (Sweden)

    M. Sambucci

    2013-01-01

    Full Text Available T cell differentiation to effector Th cells such as Th1 and Th2 requires the integration of multiple synergic and antagonist signals. Poly(ADP-ribosylation is a posttranslational modification of proteins catalyzed by Poly(ADP-ribose polymerases (PARPs. Recently, many reports showed that PARP-1, the prototypical member of the PARP family, plays a role in immune/inflammatory responses. Consistently, its enzymatic inhibition confers protection in several models of immune-mediated diseases, mainly through an inhibitory effect on NF-κB (and NFAT activation. PARP-1 regulates cell functions in many types of immune cells, including dendritic cells, macrophages, and T and B lymphocytes. Our results show that PARP-1KO cells displayed a reduced ability to differentiate in Th2 cells. Under both nonskewing and Th2-polarizing conditions, naïve CD4 cells from PARP-1KO mice generated a reduced frequency of IL-4+ cells, produced less IL-5, and expressed GATA-3 at lower levels compared with cells from wild type mice. Conversely, PARP-1 deficiency did not substantially affect differentiation to Th1 cells. Indeed, the frequency of IFN-γ+ cells as well as IFN-γ production, in nonskewing and Th1-polarizing conditions, was not affected by PARP-1 gene ablation. These findings demonstrate that PARP-1 plays a relevant role in Th2 cell differentiation and it might be a target to be exploited for the modulation of Th2-dependent immune-mediated diseases.

  1. PARP-1 expression is increased in colon adenoma and carcinoma and correlates with OGG1.

    Directory of Open Access Journals (Sweden)

    Tomasz Dziaman

    Full Text Available The ethiology of colon cancer is largely dependent on inflammation driven oxidative stress. The analysis of 8-oxodeoxyguanosine (8-oxodGuo level in leukocyte DNA of healthy controls (138 individuals, patients with benign adenomas (AD, 137 individuals and with malignant carcinomas (CRC, 169 individuals revealed a significant increase in the level of 8-oxodGuo in leukocyte DNA of AD and CRC patients in comparison to controls. The counteracting mechanism is base excision repair, in which OGG1 and PARP-1 play a key role. We investigated the level of PARP-1 and OGG1 mRNA and protein in diseased and marginal, normal tissues taken from AD and CRC patients and in leukocytes taken from the patients as well as from healthy subjects. In colon tumors the PARP-1 mRNA level was higher than in unaffected colon tissue and in polyp tissues. A high positive correlation was found between PARP-1 and OGG1 mRNA levels in all investigated tissues. This suggests reciprocal influence of PARP-1 and OGG1 on their expression and stability, and may contribute to progression of colon cancer. PARP-1 and OGG1 proteins level was several fold higher in polyps and CRC in comparison to normal colon tissues. Individuals bearing the Cys326Cys genotype of OGG1 were characterized by higher PARP-1 protein level in diseased tissues than the Ser326Cys and Ser326Ser genotypes. Aforementioned result may suggest that the diseased cells with polymorphic OGG1 recruit more PARP protein, which is necessary to remove 8-oxodGuo. Thus, patients with decreased activity of OGG1/polymorphism of the OGG1 gene and higher 8-oxodGuo level may be more susceptible to treatment with PARP-1 inhibitors.

  2. Characterization of Novel Cytoplasmic PARP in the Brain of Octopus vulgaris

    Science.gov (United States)

    DE LISA, EMILIA; DE MAIO, ANNA; MOROZ, LEONID L.; MOCCIA, FRANCESCO; MENNELLA, MARIA ROSARIA FARAONE; DI COSMO, ANNA

    2014-01-01

    Recent investigation has focused on the participation of the poly (ADP-ribose) polymerase (PARP) reaction in the invertebrate central nervous system (CNS) during the process of long-term memory (LTM). In this paper, we characterize, localize, and assign a possible role to a cytoplasmic PARP in the brain of Octopus vulgaris. PARP activity was assayed in optic lobes, supraesophageal mass, and optic nerves. The highest levels of enzyme were found in the cytoplasmic fraction. Hyper-activation of the enzyme was detected in Octopus brain after visual discrimination training. Finally, cytoplasmic PARP was found to inhibit Octopus vulgaris actin polymerization. We propose that the cytoplasmic PARP plays a role in vivo to induce the cytoskeletonal reorganization that occurs during learning-induced neuronal plasticity. PMID:22815366

  3. PARP-1: Friend or Foe of DNA Damage and Repair in Tumorigenesis?

    International Nuclear Information System (INIS)

    Swindall, Amanda F.; Stanley, Jennifer A.; Yang, Eddy S.

    2013-01-01

    Oxidative stress induced by reactive oxygen species can result in DNA damage within cells and subsequently increase risk for carcinogenesis. This may be averted by repair of DNA damage through the base or nucleotide excision repair (BER/NER) pathways. PARP, a BER protein, is known for its role in DNA-repair. However, multiple lesions can occur within a small range of DNA, known as oxidative clustered DNA lesions (OCDLs), which are difficult to repair and may lead to the more severe DNA double-strand break (DSB). Inefficient DSB repair can then result in increased mutagenesis and neoplastic transformation. OCDLs occur more frequently within a variety of tumor tissues. Interestingly, PARP is highly expressed in several human cancers. Additionally, chronic inflammation may contribute to tumorigenesis through ROS-induced DNA damage. Furthermore, PARP can modulate inflammation through interaction with NFκB and regulating the expression of inflammatory signaling molecules. Thus, the upregulation of PARP may present a double-edged sword. PARP is needed to repair ROS-induced DNA lesions, but PARP expression may lead to increased inflammation via upregulation of NFκB signaling. Here, we discuss the role of PARP in the repair of oxidative damage versus the formation of OCDLs and speculate on the feasibility of PARP inhibition for the treatment and prevention of cancers by exploiting its role in inflammation

  4. PARP-1: Friend or Foe of DNA Damage and Repair in Tumorigenesis?

    Energy Technology Data Exchange (ETDEWEB)

    Swindall, Amanda F.; Stanley, Jennifer A. [Department of Radiation Oncology Comprehensive Cancer Center, University of Alabama at Birmingham School of Medicine, 176F HSROC Suite 2232B, 1700 6th Avenue South, Birmingham, AL 35249 (United States); Yang, Eddy S., E-mail: eyang@uab.edu [Department of Radiation Oncology Comprehensive Cancer Center, University of Alabama at Birmingham School of Medicine, 176F HSROC Suite 2232B, 1700 6th Avenue South, Birmingham, AL 35249 (United States); Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35249 (United States); Department of Pharmacology and Toxicology, University of Alabama at Birmingham, Birmingham, AL 35249 (United States)

    2013-07-26

    Oxidative stress induced by reactive oxygen species can result in DNA damage within cells and subsequently increase risk for carcinogenesis. This may be averted by repair of DNA damage through the base or nucleotide excision repair (BER/NER) pathways. PARP, a BER protein, is known for its role in DNA-repair. However, multiple lesions can occur within a small range of DNA, known as oxidative clustered DNA lesions (OCDLs), which are difficult to repair and may lead to the more severe DNA double-strand break (DSB). Inefficient DSB repair can then result in increased mutagenesis and neoplastic transformation. OCDLs occur more frequently within a variety of tumor tissues. Interestingly, PARP is highly expressed in several human cancers. Additionally, chronic inflammation may contribute to tumorigenesis through ROS-induced DNA damage. Furthermore, PARP can modulate inflammation through interaction with NFκB and regulating the expression of inflammatory signaling molecules. Thus, the upregulation of PARP may present a double-edged sword. PARP is needed to repair ROS-induced DNA lesions, but PARP expression may lead to increased inflammation via upregulation of NFκB signaling. Here, we discuss the role of PARP in the repair of oxidative damage versus the formation of OCDLs and speculate on the feasibility of PARP inhibition for the treatment and prevention of cancers by exploiting its role in inflammation.

  5. Research progress of PARP-1 inhibitors in antitumor drugs and radionuclide markers

    International Nuclear Information System (INIS)

    Zhao Lingzhou; Zhang Huabei

    2011-01-01

    Poly(ADP-ribose)polymerase (PARP) is a new target in the cancer treatment nowadays. PARP not only can repair DNA damage, regulate and control transcription, maintain the stability of intracellular environment and genome, regulate the process of cell survival and death, but also is the main transcription factor in the development of inflammation and the process of cancer. To inhibit PARP activity can reduce the DNA repair function in tumor cells, and increase the sensibility to DNA damage agents, so as to improve the efficacy of radiation therapy and chemotherapy for tumor. A number of studies have suggested that, whether used alone or combination with other chemotherapy drugs, PARP inhibitors show the potential in the anti-tumor therapeutic areas. In this paper, PARP-1 inhibitors were reviewed in antitumor research progress. According to the stage of development , PARP-1 inhibitors are classified. Several representative PARP-1 inhibitors, in clinical trials, with potential clinical value were introduced. Positron emission tomography (PET), uses the main short half-life elementary in human body as tracer, and at the molecular level, achieve the no wound, quantitative and dynamic observation about the different changes of metabolites or drugs in the body. PET is the most advanced contemporary video diagnostic technology, and this paper simply introduce the research progress of PARP-1 inhibitors labeled with radioactive nuclides. (authors)

  6. Imidazoquinolinone, imidazopyridine, and isoquinolindione derivatives as novel and potent inhibitors of the poly(ADP-ribose) polymerase (PARP): a comparison with standard PARP inhibitors.

    Science.gov (United States)

    Eltze, Tobias; Boer, Rainer; Wagner, Thomas; Weinbrenner, Steffen; McDonald, Michelle C; Thiemermann, Christoph; Bürkle, Alexander; Klein, Thomas

    2008-12-01

    We have identified three novel structures for inhibitors of the poly(ADP-ribose) polymerase (PARP), a nuclear enzyme activated by strand breaks in DNA and implicated in DNA repair, apoptosis, organ dysfunction or necrosis. 2-[4-(5-Methyl-1H-imidazol-4-yl)-piperidin-1-yl]-4,5-dihydro-imidazo[4,5,1-i,j]quinolin-6-one (BYK49187), 2-(4-pyridin-2-yl-phenyl)-4,5-dihydro-imidazo[4,5,1-i,j]quinolin-6-one (BYK236864), 6-chloro-8-hydroxy-2,3-dimethyl-imidazo-[1,2-alpha]-pyridine (BYK20370), and 4-(1-methyl-1H-pyrrol-2-ylmethylene)-4H-isoquinolin-1,3-dione (BYK204165) inhibited cell-free recombinant human PARP-1 with pIC(50) values of 8.36, 7.81, 6.40, and 7.35 (pK(i) 7.97, 7.43, 5.90, and 7.05), and murine PARP-2 with pIC(50) values of 7.50, 7.55, 5.71, and 5.38, respectively. BYK49187, BYK236864, and BYK20370 displayed no selectivity for PARP-1/2, whereas BYK204165 displayed 100-fold selectivity for PARP-1. The IC(50) values for inhibition of poly(ADP-ribose) synthesis in human lung epithelial A549 and cervical carcinoma C4I cells as well in rat cardiac myoblast H9c2 cells after PARP activation by H(2)O(2) were highly significantly correlated with those at cell-free PARP-1 (r(2) = 0.89-0.96, P < 0.001) but less with those at PARP-2 (r(2) = 0.78-0.84, P < 0.01). The infarct size caused by coronary artery occlusion and reperfusion in the anesthetized rat was reduced by 22% (P < 0.05) by treatment with BYK49187 (3 mg/kg i.v. bolus and 3 mg/kg/h i.v. during 2-h reperfusion), whereas the weaker PARP inhibitors, BYK236864 and BYK20370, were not cardioprotective. In conclusion, the imidazoquinolinone BYK49187 is a potent inhibitor of human PARP-1 activity in cell-free and cellular assays in vitro and reduces myocardial infarct size in vivo. The isoquinolindione BYK204165 was found to be 100-fold more selective for PARP-1. Thus, both compounds might be novel and valuable tools for investigating PARP-1-mediated effects.

  7. PARP-1 modulation of mTOR signaling in response to a DNA alkylating agent.

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    Chantal Ethier

    Full Text Available Poly(ADP-ribose polymerase-1 (PARP-1 is widely involved in cell death responses. Depending on the degree of injury and on cell type, PARP activation may lead to autophagy, apoptosis or necrosis. In HEK293 cells exposed to the alkylating agent N-methyl-N'-nitro-N'-nitrosoguanine (MNNG, we show that PARP-1 activation triggers a necrotic cell death response. The massive poly(ADP-ribose (PAR synthesis following PARP-1 activation leads to the modulation of mTORC1 pathway. Shortly after MNNG exposure, NAD⁺ and ATP levels decrease, while AMP levels drastically increase. We characterized at the molecular level the consequences of these altered nucleotide levels. First, AMP-activated protein kinase (AMPK is activated and the mTORC1 pathway is inhibited by the phosphorylation of Raptor, in an attempt to preserve cellular energy. Phosphorylation of the mTORC1 target S6 is decreased as well as the phosphorylation of the mTORC2 component Rictor on Thr1135. Finally, Akt phosphorylation on Ser473 is lost and then, cell death by necrosis occurs. Inhibition of PARP-1 with the potent PARP inhibitor AG14361 prevents all of these events. Moreover, the antioxidant N-acetyl-L-cysteine (NAC can also abrogate all the signaling events caused by MNNG exposure suggesting that reactive oxygen species (ROS production is involved in PARP-1 activation and modulation of mTOR signaling. In this study, we show that PARP-1 activation and PAR synthesis affect the energetic status of cells, inhibit the mTORC1 signaling pathway and possibly modulate the mTORC2 complex affecting cell fate. These results provide new evidence that cell death by necrosis is orchestrated by the balance between several signaling pathways, and that PARP-1 and PAR take part in these events.

  8. Accelerated Aging during Chronic Oxidative Stress: A Role for PARP-1

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    Daniëlle M. P. H. J. Boesten

    2013-01-01

    Full Text Available Oxidative stress plays a major role in the pathophysiology of chronic inflammatory disease and it has also been linked to accelerated telomere shortening. Telomeres are specialized structures at the ends of linear chromosomes that protect these ends from degradation and fusion. Telomeres shorten with each cell division eventually leading to cellular senescence. Research has shown that poly(ADP-ribose polymerase-1 (PARP-1 and subtelomeric methylation play a role in telomere stability. We hypothesized that PARP-1 plays a role in accelerated aging in chronic inflammatory diseases due to its role as coactivator of NF-κb and AP-1. Therefore we evaluated the effect of chronic PARP-1 inhibition (by fisetin and minocycline in human fibroblasts (HF cultured under normal conditions and under conditions of chronic oxidative stress, induced by tert-butyl hydroperoxide (t-BHP. Results showed that PARP-1 inhibition under normal culturing conditions accelerated the rate of telomere shortening. However, under conditions of chronic oxidative stress, PARP-1 inhibition did not show accelerated telomere shortening. We also observed a strong correlation between telomere length and subtelomeric methylation status of HF cells. We conclude that chronic PARP-1 inhibition appears to be beneficial in conditions of chronic oxidative stress but may be detrimental under relatively normal conditions.

  9. The PARP inhibitor PJ-34 sensitizes cells to UVA-induced phototoxicity by a PARP independent mechanism

    International Nuclear Information System (INIS)

    Lakatos, Petra; Hegedűs, Csaba; Salazar Ayestarán, Nerea; Juarranz, Ángeles; Kövér, Katalin E.; Szabó, Éva; Virág, László

    2016-01-01

    Highlights: • PARP-1 is not a key regulator of photochemotherapy. • The PARP inhibitor PJ-34 sensitizes cells to UVA-induced phototoxicity by a PARP independent mechanism. • Photosensitization by PJ-34 is associated with increased ROS production and DNA damage. • Cells sensitized by PJ-34 undergo caspase-mediated apoptosis. - Abstract: A combination of a photosensitizer with light of matching wavelength is a common treatment modality in various diseases including psoriasis, atopic dermatitis and tumors. DNA damage and production of reactive oxygen intermediates may impact pathological cellular functions and viability. Here we set out to investigate the role of the nuclear DNA nick sensor enzyme poly(ADP-ribose) polymerase 1 in photochemical treatment (PCT)-induced tumor cell killing. We found that silencing PARP-1 or inhibition of its enzymatic activity with Veliparib had no significant effect on the viability of A431 cells exposed to 8-methoxypsoralen (8-MOP) and UVA (2.5 J/cm"2) indicating that PARP-1 is not likely to be a key player in either cell survival or cell death of PCT-exposed cells. Interestingly, however, another commonly used PARP inhibitor PJ-34 proved to be a photosensitizer with potency equal to 8-MOP. Irradiation of PJ-34 with UVA caused changes both in the UV absorption and in the 1H NMR spectra of the compound with the latter suggesting UVA-induced formation of tautomeric forms of the compound. Characterization of the photosensitizing effect revealed that PJ–34 + UVA triggers overproduction of reactive oxygen species, induces DNA damage, activation of caspase 3 and caspase 8 and internucleosomal DNA fragmentation. Cell death in this model could not be prevented by antioxidants (ascorbic acid, trolox, glutathione, gallotannin or cell permeable superoxide dismutase or catalase) but could be suppressed by inhibitors of caspase-3 and −8. In conclusion, PJ-34 is a photosensitizer and PJ–34 + UVA causes DNA damage and caspase

  10. The PARP inhibitor PJ-34 sensitizes cells to UVA-induced phototoxicity by a PARP independent mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Lakatos, Petra; Hegedűs, Csaba [Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen (Hungary); Salazar Ayestarán, Nerea; Juarranz, Ángeles [Department of Biology, Faculty of Sciences, Universidad Autónoma of Madrid, 28049-Madrid (Spain); Kövér, Katalin E. [Department of Inorganic and Analytical Chemistry, Faculty of Sciences, University of Debrecen, Debrecen (Hungary); Szabó, Éva [Department of Dermatology, Faculty of Medicine, University of Debrecen, Debrecen (Hungary); Virág, László, E-mail: lvirag@med.unideb.hu [Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen (Hungary); MTA-DE Cell Biology and Signaling Research Group, Debrecen (Hungary)

    2016-08-15

    Highlights: • PARP-1 is not a key regulator of photochemotherapy. • The PARP inhibitor PJ-34 sensitizes cells to UVA-induced phototoxicity by a PARP independent mechanism. • Photosensitization by PJ-34 is associated with increased ROS production and DNA damage. • Cells sensitized by PJ-34 undergo caspase-mediated apoptosis. - Abstract: A combination of a photosensitizer with light of matching wavelength is a common treatment modality in various diseases including psoriasis, atopic dermatitis and tumors. DNA damage and production of reactive oxygen intermediates may impact pathological cellular functions and viability. Here we set out to investigate the role of the nuclear DNA nick sensor enzyme poly(ADP-ribose) polymerase 1 in photochemical treatment (PCT)-induced tumor cell killing. We found that silencing PARP-1 or inhibition of its enzymatic activity with Veliparib had no significant effect on the viability of A431 cells exposed to 8-methoxypsoralen (8-MOP) and UVA (2.5 J/cm{sup 2}) indicating that PARP-1 is not likely to be a key player in either cell survival or cell death of PCT-exposed cells. Interestingly, however, another commonly used PARP inhibitor PJ-34 proved to be a photosensitizer with potency equal to 8-MOP. Irradiation of PJ-34 with UVA caused changes both in the UV absorption and in the 1H NMR spectra of the compound with the latter suggesting UVA-induced formation of tautomeric forms of the compound. Characterization of the photosensitizing effect revealed that PJ–34 + UVA triggers overproduction of reactive oxygen species, induces DNA damage, activation of caspase 3 and caspase 8 and internucleosomal DNA fragmentation. Cell death in this model could not be prevented by antioxidants (ascorbic acid, trolox, glutathione, gallotannin or cell permeable superoxide dismutase or catalase) but could be suppressed by inhibitors of caspase-3 and −8. In conclusion, PJ-34 is a photosensitizer and PJ–34 + UVA causes DNA damage and caspase

  11. Tumor suppressive effect of PARP1 and FOXO3A in gastric cancers and its clinical implications

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    Yoon, Sarah; Jo, Yuna; Kwon, So Mee; Kim, Kyoung Min; Kwon, Keun Sang; Kim, Chan Young; Woo, Hyun Goo

    2015-01-01

    Poly (ADP-ribose) polymerase1 (PARP1) has been reported as a possible target for chemotherapy in many cancer types. However, its action mechanisms and clinical implications for gastric cancer survival are not yet fully understood. Here, we investigated the effect of PARP1 inhibition in the growth of gastric cancer cells. PARP1 inhibition by Olaparib or PARP1 siRNA could significantly attenuate growth and colony formation of gastric cancer cells, and which were mediated through induction of G2/M cell cycle arrest but not apoptosis. FOXO3A expression was induced by PARP1 inhibition, suggesting that FOXO3A might be one of downstream target of the PARP1 effect on gastric cancer cell growth. In addition, by performing tissue microarrays on the 166 cases of gastric cancer patients, we could observe that the expression status of PARP1 and FOXO3A were significantly associated with overall survival (OS) and relapse-free survival (RFS). Strikingly, combined expression status of PARP1 and FOXO3A showed better prediction for patient's clinical outcomes. The patient group with PARP1+/FOXO3A− expression had the worst prognosis while the patient group with PARP1−/FOXO3A+ had the most favorable prognosis (OS: P = 6.0 × 10−9, RFS: P = 2.2 × 10−8). In conclusion, we suggest that PARP1 and FOXO3A play critical roles in gastric cancer progression, and might have therapeutic and/or diagnostic potential in clinic. PMID:26540566

  12. Role of PARP activity in lung cancer-induced cachexia: Effects on muscle oxidative stress, proteolysis, anabolic markers, and phenotype.

    Science.gov (United States)

    Chacon-Cabrera, Alba; Mateu-Jimenez, Mercè; Langohr, Klaus; Fermoselle, Clara; García-Arumí, Elena; Andreu, Antoni L; Yelamos, Jose; Barreiro, Esther

    2017-12-01

    Strategies to treat cachexia are still at its infancy. Enhanced muscle protein breakdown and ubiquitin-proteasome system are common features of cachexia associated with chronic conditions including lung cancer (LC). Poly(ADP-ribose) polymerases (PARP), which play a major role in chromatin structure regulation, also underlie maintenance of muscle metabolism and body composition. We hypothesized that protein catabolism, proteolytic markers, muscle fiber phenotype, and muscle anabolism may improve in respiratory and limb muscles of LC-cachectic Parp-1-deficient (Parp-1 -/- ) and Parp-2 -/- mice. In diaphragm and gastrocnemius of LC (LP07 adenocarcinoma) bearing mice (wild type, Parp-1 -/- , and Parp-2 -/- ), PARP activity (ADP-ribose polymers, pADPr), redox balance, muscle fiber phenotype, apoptotic nuclei, tyrosine release, protein ubiquitination, muscle-specific E3 ligases, NF-κB signaling pathway, markers of muscle anabolism (Akt, mTOR, p70S6K, and mitochondrial DNA) were evaluated along with body and muscle weights, and limb muscle force. Compared to wild type cachectic animals, in both respiratory and limb muscles of Parp-1 -/- and Parp-2 -/- cachectic mice: cancer induced-muscle wasting characterized by increased PARP activity, protein oxidation, tyrosine release, and ubiquitin-proteasome system (total protein ubiquitination, atrogin-1, and 20S proteasome C8 subunit) were blunted, the reduction in contractile myosin and atrophy of the fibers was attenuated, while no effects were seen in other structural features (inflammatory cells, internal or apoptotic nuclei), and markers of muscle anabolism partly improved. Activation of either PARP-1 or -2 is likely to play a role in muscle protein catabolism via oxidative stress, NF-κB signaling, and enhanced proteasomal degradation in cancer-induced cachexia. Therapeutic potential of PARP activity inhibition deserves attention. © 2017 Wiley Periodicals, Inc.

  13. Investigation of PARP-1, PARP-2, and PARG interactomes by affinity-purification mass spectrometry

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    Isabelle Maxim

    2010-04-01

    Full Text Available Abstract Background Poly(ADP-ribose polymerases (PARPs catalyze the formation of poly(ADP-ribose (pADPr, a post-translational modification involved in several important biological processes, namely surveillance of genome integrity, cell cycle progression, initiation of the DNA damage response, apoptosis, and regulation of transcription. Poly(ADP-ribose glycohydrolase (PARG, on the other hand, catabolizes pADPr and thereby accounts for the transient nature of poly(ADP-ribosylation. Our investigation of the interactomes of PARP-1, PARP-2, and PARG by affinity-purification mass spectrometry (AP-MS aimed, on the one hand, to confirm current knowledge on these interactomes and, on the other hand, to discover new protein partners which could offer insights into PARPs and PARG functions. Results PARP-1, PARP-2, and PARG were immunoprecipitated from human cells, and pulled-down proteins were separated by gel electrophoresis prior to in-gel trypsin digestion. Peptides were identified by tandem mass spectrometry. Our AP-MS experiments resulted in the identifications of 179 interactions, 139 of which are novel interactions. Gene Ontology analysis of the identified protein interactors points to five biological processes in which PARP-1, PARP-2 and PARG may be involved: RNA metabolism for PARP-1, PARP-2 and PARG; DNA repair and apoptosis for PARP-1 and PARP-2; and glycolysis and cell cycle for PARP-1. Conclusions This study reveals several novel protein partners for PARP-1, PARP-2 and PARG. It provides a global view of the interactomes of these proteins as well as a roadmap to establish the systems biology of poly(ADP-ribose metabolism.

  14. Studies of the expression of human poly(ADP-ribose) polymerase-1 in Saccharomyces cerevisiae and identification of PARP-1 substrates by yeast proteome microarray screening.

    Science.gov (United States)

    Tao, Zhihua; Gao, Peng; Liu, Hung-Wen

    2009-12-15

    Poly(ADP-ribosyl)ation of various nuclear proteins catalyzed by a family of NAD(+)-dependent enzymes, poly(ADP-ribose) polymerases (PARPs), is an important posttranslational modification reaction. PARP activity has been demonstrated in all types of eukaryotic cells with the exception of yeast, in which the expression of human PARP-1 was shown to lead to retarded cell growth. We investigated the yeast growth inhibition caused by human PARP-1 expression in Saccharomyces cerevisiae. Flow cytometry analysis reveals that PARP-1-expressing yeast cells accumulate in the G(2)/M stage of the cell cycle. Confocal microscopy analysis shows that human PARP-1 is distributed throughout the nucleus of yeast cells but is enriched in the nucleolus. Utilizing yeast proteome microarray screening, we identified 33 putative PARP-1 substrates, six of which are known to be involved in ribosome biogenesis. The poly(ADP-ribosyl)ation of three of these yeast proteins, together with two human homologues, was confirmed by an in vitro PARP-1 assay. Finally, a polysome profile analysis using sucrose gradient ultracentrifugation demonstrated that the ribosome levels in yeast cells expressing PARP-1 are lower than those in control yeast cells. Overall, our data suggest that human PARP-1 may affect ribosome biogenesis by modifying certain nucleolar proteins in yeast. The artificial PARP-1 pathway in yeast may be used as a simple platform to identify substrates and verify function of this important enzyme.

  15. Vasoactivity of rucaparib, a PARP-1 inhibitor, is a complex process that involves myosin light chain kinase, P2 receptors, and PARP itself.

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    Cian M McCrudden

    Full Text Available Therapeutic inhibition of poly(ADP-ribose polymerase (PARP, as monotherapy or to supplement the potencies of other agents, is a promising strategy in cancer treatment. We previously reported that the first PARP inhibitor to enter clinical trial, rucaparib (AG014699, induced vasodilation in vivo in xenografts, potentiating response to temozolomide. We now report that rucaparib inhibits the activity of the muscle contraction mediator myosin light chain kinase (MLCK 10-fold more potently than its commercially available inhibitor ML-9. Moreover, rucaparib produces additive relaxation above the maximal degree achievable with ML-9, suggesting that MLCK inhibition is not solely responsible for dilation. Inhibition of nitric oxide synthesis using L-NMMA also failed to impact rucaparib's activity. Rucaparib contains the nicotinamide pharmacophore, suggesting it may inhibit other NAD+-dependent processes. NAD+ exerts P2 purinergic receptor-dependent inhibition of smooth muscle contraction. Indiscriminate blockade of the P2 purinergic receptors with suramin abrogated rucaparib-induced vasodilation in rat arterial tissue without affecting ML-9-evoked dilation, although the specific receptor subtypes responsible have not been unequivocally identified. Furthermore, dorsal window chamber and real time tumor vessel perfusion analyses in PARP-1-/- mice indicate a potential role for PARP in dilation of tumor-recruited vessels. Finally, rucaparib provoked relaxation in 70% of patient-derived tumor-associated vessels. These data provide tantalising evidence of the complexity of the mechanism underlying rucaparib-mediated vasodilation.

  16. ROS-mediated PARP activity undermines mitochondrial function after permeability transition pore opening during myocardial ischemia-reperfusion.

    Science.gov (United States)

    Schriewer, Jacqueline M; Peek, Clara Bien; Bass, Joseph; Schumacker, Paul T

    2013-04-18

    Ischemia-reperfusion (I/R) studies have implicated oxidant stress, the mitochondrial permeability transition pore (mPTP), and poly(ADP-ribose) polymerase (PARP) as contributing factors in myocardial cell death. However, the interdependence of these factors in the intact, blood-perfused heart is not known. We therefore wanted to determine whether oxidant stress, mPTP opening, and PARP activity contribute to the same death pathway after myocardial I/R. A murine left anterior descending coronary artery (LAD) occlusion (30 minutes) and release (1 to 4 hours) model was employed. Experimental groups included controls and antioxidant-treated, mPTP-inhibited, or PARP-inhibited hearts. Antioxidant treatment prevented oxidative damage, mPTP opening, ATP depletion, and PARP activity, placing oxidant stress as the proximal death trigger. Genetic deletion of cyclophilin D (CypD(-/-)) prevented loss of total NAD(+) and PARP activity, and mPTP-mediated loss of mitochondrial function. Control hearts showed progressive mitochondrial depolarization and loss of ATP from 1.5 to 4 hours of reperfusion, but not outer mitochondrial membrane rupture. Neither genetic deletion of PARP-1 nor its pharmacological inhibition prevented the initial mPTP-mediated depolarization or loss of ATP, but PARP ablation did allow mitochondrial recovery by 4 hours of reperfusion. These results indicate that oxidant stress, the mPTP, and PARP activity contribute to a single death pathway after I/R in the heart. PARP activation undermines cell survival by preventing mitochondrial recovery after mPTP opening early in reperfusion. This suggests that PARP-mediated prolongation of mitochondrial depolarization contributes significantly to cell death via an energetic crisis rather than by mitochondrial outer membrane rupture.

  17. PARP Inhibitors in Ovarian Cancer.

    Science.gov (United States)

    Mittica, Gloria; Ghisoni, Eleonora; Giannone, Gaia; Genta, Sofia; Aglietta, Massimo; Sapino, Anna; Valabrega, Giorgio

    2018-03-05

    Treatment of Epithelial Ovarian Cancer (EOC), historically based on surgery and platinum doublet chemotherapy, is associated with high risk of relapse and poor prognosis for recurrent disease. In this landscape, the innovative treatment with PARP inhibitors (PARPis) demonstrated an outstanding activity in EOC, and is currently changing clinical practice in BRCA mutant patients. To highlight the mechanism of action, pharmacokinetics, clinical activity, indications and current strategies of development of Olaparib, Niraparib, Rucaparib, Talazoparib and Veliparib, the 5 most relevant PARPis. We performed a review on Pubmed using 'ovarian cancer' and the name of each PARPi (PARP inhibitor) discussed in the review as Medical Subject Headings (MeSH) keywords. The same search was performed on "clinicaltrial.gov" to identify ongoing clinical trials and on "google.com/patents" and "uspto.gov" for recent patents exploring PARPIs in ovarian cancer. Olaparib, Niraparib and Rucaparib are already approved for treatment of recurrent EOC and their indications are partially overlapping. Talazoparib and Veliparib are promising PARPis, but currently under investigation in early phase trials. Several studies are evaluating PARPis in monotherapy or in associations, in a wide range of settings (i.e. first line, neoadjuvant, platinum-sensitive and resistant disease). PARPis are valuable options in patients with recurrent ovarian cancer with promising activity in different stages of this disease. Further studies are required to better define optimal clinical settings, predictors of response beyond BRCA mutations and strategies to overcome secondary resistance of PARPis therapy in EOC. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  18. The PARP inhibitor PJ-34 sensitizes cells to UVA-induced phototoxicity by a PARP independent mechanism.

    Science.gov (United States)

    Lakatos, Petra; Hegedűs, Csaba; Salazar Ayestarán, Nerea; Juarranz, Ángeles; Kövér, Katalin E; Szabó, Éva; Virág, László

    2016-08-01

    A combination of a photosensitizer with light of matching wavelength is a common treatment modality in various diseases including psoriasis, atopic dermatitis and tumors. DNA damage and production of reactive oxygen intermediates may impact pathological cellular functions and viability. Here we set out to investigate the role of the nuclear DNA nick sensor enzyme poly(ADP-ribose) polymerase 1 in photochemical treatment (PCT)-induced tumor cell killing. We found that silencing PARP-1 or inhibition of its enzymatic activity with Veliparib had no significant effect on the viability of A431 cells exposed to 8-methoxypsoralen (8-MOP) and UVA (2.5J/cm(2)) indicating that PARP-1 is not likely to be a key player in either cell survival or cell death of PCT-exposed cells. Interestingly, however, another commonly used PARP inhibitor PJ-34 proved to be a photosensitizer with potency equal to 8-MOP. Irradiation of PJ-34 with UVA caused changes both in the UV absorption and in the 1H NMR spectra of the compound with the latter suggesting UVA-induced formation of tautomeric forms of the compound. Characterization of the photosensitizing effect revealed that PJ-34+UVA triggers overproduction of reactive oxygen species, induces DNA damage, activation of caspase 3 and caspase 8 and internucleosomal DNA fragmentation. Cell death in this model could not be prevented by antioxidants (ascorbic acid, trolox, glutathione, gallotannin or cell permeable superoxide dismutase or catalase) but could be suppressed by inhibitors of caspase-3 and -8. In conclusion, PJ-34 is a photosensitizer and PJ-34+UVA causes DNA damage and caspase-mediated cell death independently of PARP-1 inhibition. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Hyperactivation of PARP triggers nonhomologous end-joining in repair-deficient mouse fibroblasts.

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    Natalie R Gassman

    Full Text Available Regulation of poly(ADP-ribose (PAR synthesis and turnover is critical to determining cell fate after genotoxic stress. Hyperactivation of PAR synthesis by poly(ADP-ribose polymerase-1 (PARP-1 occurs when cells deficient in DNA repair are exposed to genotoxic agents; however, the function of this hyperactivation has not been adequately explained. Here, we examine PAR synthesis in mouse fibroblasts deficient in the base excision repair enzyme DNA polymerase β (pol β. The extent and duration of PARP-1 activation was measured after exposure to either the DNA alkylating agent, methyl methanesulfonate (MMS, or to low energy laser-induced DNA damage. There was strong DNA damage-induced hyperactivation of PARP-1 in pol β nullcells, but not in wild-type cells. In the case of MMS treatment, PAR synthesis did not lead to cell death in the pol β null cells, but instead resulted in increased PARylation of the nonhomologous end-joining (NHEJ protein Ku70 and increased association of Ku70 with PARP-1. Inhibition of the NHEJ factor DNA-PK, under conditions of MMS-induced PARP-1 hyperactivation, enhanced necrotic cell death. These data suggest that PARP-1 hyperactivation is a protective mechanism triggering the classical-NHEJ DNA repair pathway when the primary alkylated base damage repair pathway is compromised.

  20. PARP1 inhibitors: contemporary attempts at their use in anticancer therapy and future perspective

    Directory of Open Access Journals (Sweden)

    Ewelina Wiśnik

    2016-04-01

    Full Text Available Current cancer therapies are based mainly on the use of compounds that cause DNA damage. Unfortunately, even the combination therapies do not give rewarding effects, due to the high efficiency of DNA damage repair mechanisms in tumor cells. Therefore, the present studies should be focused on proteins that are involved in DNA repair systems. Poly(ADP-ribose polymerase-1 is an example of a protein commonly known as an enzyme that plays a role in the detection of DNA damage and repair. Activation of PARP1 in response to DNA damage leads to poly-ADP-ribosylation of proteins contributing to DNA repair systems, therefore facilitating the maintenance of genome stability. On the other hand, inhibition of PARP1 enzyme results in the accumulation of DNA damage, which in turn contributes to cell death. Studies on inhibitors of PARP1 are still ongoing, and some of them are currently in the third phase of clinical trials. To date, only one representative of the PARP1 inhibitors, called olaparib, has been approved for anti-cancer therapy in the EU and the USA. Moreover, a growing body of evidence indicates a role of this protein in various intracellular processes such as bioenergetics, proliferation, regulation of gene expression, cell death as well as immunoregulation. A number of different intracellular processes regulated by PARP1 give rise to potential wider use of PARP1 inhibitors in treatment of other diseases, including immune or autoimmune disorders.

  1. PARP-1 Interaction with and Activation by Histones and Nucleosomes.

    Science.gov (United States)

    Thomas, Colin; Kotova, Elena; Tulin, Alexei V

    2017-01-01

    Poly(ADP-ribose) Polymerase 1 (PARP-1) is an abundant chromatin associated protein, typical for most eukaryotic nuclei. The localization of PARP-1 in chromatin and its enzymatic activation involves multiple interactions of PARP-1 with nucleosomal histones, other proteins, and DNA. We report a set of methods designed to reconstitute PARP-1 regulation in vitro. These methods involve the expression of PARP-1 and PARP-1-regulating proteins using bacterial and eukaryotic systems, purification of these proteins using chromatography, testing of individual interactions in vitro, assembly of active complexes, and reconstitution of PARP-1 regulating reactions in vitro.

  2. In Vitro Inhibition of Klebsiella pneumoniae by Lactobacillus delbrueckii Subsp. delbrueckii LDD01 (DSM 22106): An Innovative Strategy to Possibly Counteract Such Infections in Humans?

    Science.gov (United States)

    Mogna, Luca; Deidda, Francesca; Nicola, Stefania; Amoruso, Angela; Del Piano, Mario; Mogna, Giovanni

    To determine the in vitro antimicrobial activity of selected Lactobacillus strains isolated from the feces of healthy humans against Klebsiella pneumoniae. Klebsiella is ubiquitous in nature and may colonize the skin, the pharynx, or the gastrointestinal tract of humans. Despite the widespread use of antibiotic molecules with a broad spectrum in hospitalized patients, an increased overall load of klebsiellae as well as the subsequent development of multidrug-resistant strains able to synthesize extended-spectrum beta-lactamase have been registered. These strains are particularly virulent, express capsular-type K55, and have a considerable ability to propagate. The 4 strains Lactobacillus paracasei LPC01 (CNCM I-1390), Lactobacillus rhamnosus LR04 (DSM 16605), Bifidobacterium longum B2274 (DSM 24707), and Lactobacillus delbrueckii subsp. delbrueckii LDD01 (DSM 22106) were tested. The analysis was performed using both a disc-diffusion assay and the broth-dilution procedure, also including an evaluation of the supernatants obtained from a fresh broth culture of each bacterium. L. delbrueckii subsp. delbrueckii LDD01 demonstrated the best inhibitory results among all the tested strains. The antibacterial activity of the supernatant was retained even after treatment with α-amylase and neutralization with NaOH 1N, thus suggesting the protein structure of the inhibitory molecule. In contrast, it was completely lost after treatment with proteinase K. Overall results suggest that the inhibitory effect of L. delbrueckii subsp. delbrueckii LDD01 should be attributed to the production of a bacteriocin. This strain may be prospectively useful for strengthening probiotic formulations and possibly counteract infections by K. pneumoniae in humans.

  3. Inhibition of glycogen synthase kinase-3β counteracts ligand-independent activity of the androgen receptor in castration resistant prostate cancer.

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    Stefanie V Schütz

    Full Text Available In order to generate genomic signals, the androgen receptor (AR has to be transported into the nucleus upon androgenic stimuli. However, there is evidence from in vitro experiments that in castration-resistant prostate cancer (CRPC cells the AR is able to translocate into the nucleus in a ligand-independent manner. The recent finding that inhibition of the glycogen-synthase-kinase 3β (GSK-3β induces a rapid nuclear export of the AR in androgen-stimulated prostate cancer cells prompted us to analyze the effects of a GSK-3β inhibition in the castration-resistant LNCaP sublines C4-2 and LNCaP-SSR. Both cell lines exhibit high levels of nuclear AR in the absence of androgenic stimuli. Exposure of these cells to the maleimide SB216763, a potent GSK-3β inhibitor, resulted in a rapid nuclear export of the AR even under androgen-deprived conditions. Moreover, the ability of C4-2 and LNCaP-SSR cells to grow in the absence of androgens was diminished after pharmacological inhibition of GSK-3β in vitro. The ability of SB216763 to modulate AR signalling and function in CRPC in vivo was additionally demonstrated in a modified chick chorioallantoic membrane xenograft assay after systemic delivery of SB216763. Our data suggest that inhibition of GSK-3β helps target the AR for export from the nucleus thereby diminishing the effects of mislocated AR in CRPC cells. Therefore, inhibition of GSK-3β could be an interesting new strategy for the treatment of CRPC.

  4. P2X7 receptor-mediated PARP1 activity regulates astroglial death in the rat hippocampus following status epilepticus

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    Ji Yang eKim

    2015-09-01

    Full Text Available Poly(ADP-ribose polymerase-1 (PARP1 plays a regulatory role in apoptosis, necrosis, and other cellular processes after injury. Recently, we revealed that PARP1 regulates the differential neuronal/astroglial responses to pilocarpine-induced status epilepticus (SE in the distinct brain regions. In addition, P2X7 receptor (P2X7R, an ATP-gated ion channel, activation accelerates astroglial apoptosis, while it attenuates clasmatodendrosis (lysosome-derived autophagic astroglial death. Therefore, we investigated whether P2X7R regulates regional specific astroglial PARP1 expression/activation in response to SE. In the present study, P2X7R activation exacerbates SE-induced astroglial apoptosis, while P2X7R inhibition attenuates it accompanied by increasing PARP1 activity in the molecular layer of the dentate gyrus following SE. In the CA1 region, however, P2X7R inhibition deteriorates SE-induced clasmatodendrosis via PARP1 activation following SE. Taken together, our findings suggest that P2X7R function may affect SE-induced astroglial death by regulating PARP1 activation/expression in regional-specific manner. Therefore, the selective modulation of P2X7R-mediated PARP1 functions may be a considerable strategy for controls in various types of cell deaths.

  5. Rosmarinic acid counteracts activation of hepatic stellate cells via inhibiting the ROS-dependent MMP-2 activity: Involvement of Nrf2 antioxidant system

    International Nuclear Information System (INIS)

    Lu, Changfang; Zou, Yu; Liu, Yuzhang; Niu, Yingcai

    2017-01-01

    Recently, oxidative stress is involved in hepatofibrogenesis. Matrix metalloproteinase-2 (MMP-2) is required for activation of hepatic stellate cells (HSCs) in response to reactive oxygen species (ROS). This study was designed to explore the hypothesis that the inhibitory effect of rosmarinic acid (RA) on HSCs activation might mainly result from its antioxidant capability by increasing the synthesis of glutathione (GSH) involved in nuclear factor kappa B (NF-κB)-dependent inhibition of MMP-2 activity. Here, we demonstrate that RA reverses activated HSCs to quiescent cells. Concomitantly, RA inhibits MMP-2 activity. RNA interference-imposed knockdown of NF-κB abolished down-regulation of MMP-2 by RA. RA-mediated inactivation of NF-κB could be blocked by the diphenyleneiodonium chloride (DPI; a ROS inhibitor). Conversely, transfection of dominant-negative (DN) mutant of extracellular signal-regulated kinases 2 (ERK2), c-Jun N-terminal kinase 1 (JNK1), or p38α kinase had no such effect. Simultaneously, RA suppresses ROS generation and lipid peroxidation (LPO) whereas increases cellular GSH in HSC-T6 cells. Furthermore, RA significantly increased antioxidant response element (ARE)-mediated luciferase activity, nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and catalytic subunits from glutamate cysteine ligase (GCLc) expression, but not modulatory subunits from GCL (GCLm). RA-mediated up-regulation of GClc is inhibited by the shRNA-induced Nrf2 knockdown. The knocking down of Nrf2 or buthionine sulfoximine (a GCL inhibitor) abolished RA-mediated inhibition of ROS. Collectively, these results provide novel insights into the mechanisms of RA as an antifibrogenic candidate in the prevention and treatment of liver fibrosis. - Highlights: • RA reverses activated HSCs to quiescent cells. • RA suppresses MMP-2 activity through a NF-κB-dependent pathway. • Inhibition of oxidative stress by RA is dependent on nuclear translocation of Nrf2

  6. Rosmarinic acid counteracts activation of hepatic stellate cells via inhibiting the ROS-dependent MMP-2 activity: Involvement of Nrf2 antioxidant system

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Changfang; Zou, Yu; Liu, Yuzhang; Niu, Yingcai, E-mail: nyc1968@126.com

    2017-03-01

    Recently, oxidative stress is involved in hepatofibrogenesis. Matrix metalloproteinase-2 (MMP-2) is required for activation of hepatic stellate cells (HSCs) in response to reactive oxygen species (ROS). This study was designed to explore the hypothesis that the inhibitory effect of rosmarinic acid (RA) on HSCs activation might mainly result from its antioxidant capability by increasing the synthesis of glutathione (GSH) involved in nuclear factor kappa B (NF-κB)-dependent inhibition of MMP-2 activity. Here, we demonstrate that RA reverses activated HSCs to quiescent cells. Concomitantly, RA inhibits MMP-2 activity. RNA interference-imposed knockdown of NF-κB abolished down-regulation of MMP-2 by RA. RA-mediated inactivation of NF-κB could be blocked by the diphenyleneiodonium chloride (DPI; a ROS inhibitor). Conversely, transfection of dominant-negative (DN) mutant of extracellular signal-regulated kinases 2 (ERK2), c-Jun N-terminal kinase 1 (JNK1), or p38α kinase had no such effect. Simultaneously, RA suppresses ROS generation and lipid peroxidation (LPO) whereas increases cellular GSH in HSC-T6 cells. Furthermore, RA significantly increased antioxidant response element (ARE)-mediated luciferase activity, nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and catalytic subunits from glutamate cysteine ligase (GCLc) expression, but not modulatory subunits from GCL (GCLm). RA-mediated up-regulation of GClc is inhibited by the shRNA-induced Nrf2 knockdown. The knocking down of Nrf2 or buthionine sulfoximine (a GCL inhibitor) abolished RA-mediated inhibition of ROS. Collectively, these results provide novel insights into the mechanisms of RA as an antifibrogenic candidate in the prevention and treatment of liver fibrosis. - Highlights: • RA reverses activated HSCs to quiescent cells. • RA suppresses MMP-2 activity through a NF-κB-dependent pathway. • Inhibition of oxidative stress by RA is dependent on nuclear translocation of Nrf2

  7. CyPPA, a Positive SK3/SK2 Modulator, Reduces Activity of Dopaminergic Neurons, Inhibits Dopamine Release, and Counteracts Hyperdopaminergic Behaviors Induced by Methylphenidate

    DEFF Research Database (Denmark)

    Herrik, Kjartan F; Redrobe, John P; Holst, Dorte

    2012-01-01

    Dopamine (DA) containing midbrain neurons play critical roles in several psychiatric and neurological diseases, including schizophrenia and attention deficit hyperactivity disorder, and the substantia nigra pars compacta neurons selectively degenerate in Parkinson's disease. Pharmacological......]-amine (CyPPA), a subtype-selective positive modulator of SK channels (SK3¿>¿SK2¿>¿>¿>¿SK1, IK), decreased spontaneous firing rate, increased the duration of the apamin-sensitive afterhyperpolarization, and caused an activity-dependent inhibition of current-evoked action potentials in DA neurons from both...

  8. PARP1 Val762Ala polymorphism reduces enzymatic activity

    International Nuclear Information System (INIS)

    Wang Xiaogan; Wang Zhaoqi; Tong Weimin; Shen Yan

    2007-01-01

    Poly(ADP-ribose) polymerase 1 (PARP1) modifies a variety of nuclear proteins by poly(ADP-ribosyl)ation, and plays diverse roles in molecular and cellular processes. A common PARP1 single nucleotide polymorphism (SNP) at codon 762, resulting in the substitution of alanine (Ala) for valine (Val) in the catalytic domain has been implicated in susceptibility to cancer. To characterize the functional effect of this polymorphism on PARP1, we performed in vitro enzymatic analysis on PARP1-Ala762 and PARP1-Val762. We found that PARP1-Ala762 displayed 57.2% of the activity of PARP1-Val762 for auto-poly(ADP-ribosyl)ation and 61.9% of the activity of PARP1-Val762 for trans-poly(ADP-ribosyl)ation of histone H1. The kinetic characterization revealed that the K m of PARP1-Ala762 was increased to a 1.2-fold of the K m of PARP1-Val762 for trans-poly(ADP-ribosyl)ation. Thus, the PARP1 Val762Ala polymorphism reduces the enzymatic activity of PARP1 by increasing K m . This finding suggests that different levels of poly(ADP-ribosyl)ation by PARP1 might aid in understanding Cancer risk of carriers of the PARP1 Val762Ala polymorphism

  9. Effect of MRE11 loss on PARP-inhibitor sensitivity in endometrial cancer in vitro.

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    Romana Koppensteiner

    Full Text Available To evaluate the frequency of MRE11/RAD50/NBS1 (MRN-complex loss of protein expression in endometrial cancers (EC and to determine whether loss of MRE11 renders the cancer cells sensitive to Poly(ADP-ribose polymerase (PARP-inhibitory treatment.MRN expression was examined in 521 samples of endometrial carcinomas and in 10 cancer cell lines. A putative mutation hotspot in the form of an intronic poly(T allele in MRE11 was sequenced in selected cases (n = 26. Sensitivity to the PARP-inhibitor, BMN673 was tested in colony formation assays before and after MRE11 silencing using siRNA. Homologous recombination (HR DNA repair was evaluated by RAD51-foci formation assay upon irradiation and drug treatment.Loss of MRE11 protein was found in 30.7% of EC tumours and significantly associated with loss of RAD50, NBS1 and mismatch repair protein expression. One endometrial cell line showed a markedly reduced MRE11 expression due to a homozygous poly(T mutation of MRE11, thereby exhibiting an increased sensitivity to BMN673. MRE11 depletion sensitizes MRE11 expressing EC cell lines to the treatment with BMN673. The increased sensitivity to PARP-inhibition correlates with reduced RAD51 foci formation upon ionizing radiation in MRE11-depleted cells.Loss of the MRE11 protein predicts sensitivity to PARP-inhibitor sensitivity in vitro, defining it as an additional synthetic lethal gene with PARP. The high incidence of MRE11 loss in ECs can be potentially exploited for PARP-inhibitor therapy. Furthermore, MRE11 protein expression using immunohistochemistry could be investigated as a predictive biomarker for PARP-inhibitor treatment.

  10. Defective mitophagy in XPA via PARP-1 hyperactivation and NAD(+)/SIRT1 reduction

    DEFF Research Database (Denmark)

    Fang, Evandro Fei; Scheibye-Knudsen, Morten; Brace, Lear E

    2014-01-01

    with excessive cleavage of PINK1 and increased mitochondrial membrane potential. The mitochondrial abnormalities appear to be caused by decreased activation of the NAD(+)-SIRT1-PGC-1α axis triggered by hyperactivation of the DNA damage sensor PARP-1. This phenotype is rescued by PARP-1 inhibition...... or by supplementation with NAD(+) precursors that also rescue the lifespan defect in xpa-1 nematodes. Importantly, this pathogenesis appears common to ataxia-telangiectasia and Cockayne syndrome, two other DNA repair disorders with neurodegeneration, but absent in XPC, a DNA repair disorder without neurodegeneration...

  11. PARP-1 como regulador del ciclo celular

    OpenAIRE

    Iglesias Vázquez, Pablo

    2015-01-01

    En el presente estudio hemos querido investigar las implicaciones biológicas de la interacción PARP-1/E2F-1 en escenarios en los que el factor de transcripción E2F-1 resulta de gran importancia como son el desarrollo embrionario y la oncogénesis. En este respecto, hemos demostrado que tanto PJ34, inhibidor de la actividad enzimática de PARP, como gosipol, inhibidor de las interacciones proteína-proteína, son capaces de reducir la actividad transcripcional de E2F-1 y la proli...

  12. Sigma-2 ligands and PARP inhibitors synergistically trigger cell death in breast cancer cells

    International Nuclear Information System (INIS)

    McDonald, Elizabeth S.; Mankoff, Julia; Makvandi, Mehran; Chu, Wenhua; Chu, Yunxiang; Mach, Robert H.; Zeng, Chenbo

    2017-01-01

    The sigma-2 receptor is overexpressed in proliferating cells compared to quiescent cells and has been used as a target for imaging solid tumors by positron emission tomography. Recent work has suggested that the sigma-2 receptor may also be an effective therapeutic target for cancer therapy. Poly (ADP-ribose) polymerase (PARP) is a family of enzymes involved in DNA damage response. In this study, we looked for potential synergy of cytotoxicity between PARP inhibitors and sigma-2 receptor ligands in breast cancer cell lines. We showed that the PARP inhibitor, YUN3-6, sensitized mouse breast cancer cell line, EMT6, to sigma-2 receptor ligand (SV119, WC-26, and RHM-138) induced cell death determined by cell viability assay and colony forming assay. The PARP inhibitor, olaparib, sensitized tumor cells to a different sigma-2 receptor ligand SW43-induced apoptosis and cell death in human triple negative cell line, MDA-MB-231. Olaparib inhibited PARP activity and cell proliferation, and arrested cells in G2/M phase of the cell cycle in MDA-MB-231 cells. Subsequently cells became sensitized to SW43 induced cell death. In conclusion, the combination of sigma-2 receptor ligands and PARP inhibitors appears to hold promise for synergistically triggering cell death in certain types of breast cancer cells and merits further investigation. - Highlights: • PARPi, YUN3-6 and olaparib, and σ2 ligands, SV119 and SW43, were evaluated. • Mouse and human breast cancer cells, EMT6 and MDA-MB-231 respectively, were used. • YUN3-6 and SV119 synergistically triggered cell death in EMT6 cells. • Olaparib and SW43 additively triggered cell death in MDA-MB-231 cells. • Olaparib arrested cells in G2/M in MDA-MB-231 cells.

  13. PARP-1 is a key player in controlling apoptosis induced by high LET carbon ion beam and low LET gamma radiation in HeLa cells

    International Nuclear Information System (INIS)

    Ghorai, Atanu; Ghosh, Utpal; Bhattacharyya, Nitai P.; Sarma, Asitikantha

    2014-01-01

    PARP-1 inhibitors have long been used as chemo-sensitizer or radio-sensitizer and specific PARP-1 inhibitors are also in clinical trial for the treatment of various cancers. PARP-1 is not only involved in DNA repair but also plays very complex role in induction of apoptosis in postirradiation condition. Our objective is to investigate role of PARP-1 in apoptosis triggered by high LET carbon ion beam (CIB) and low LET gamma. We have treated HeLa and PARP-1 knock down HeLa (Hsil) cells with various doses of CIB and gamma. We measured DNA damage by comet assay and various apoptotic parameters such as nuclear fragmentation, activation of caspase-3,8,9, AIF translocation etc. We observed higher DNA breaks and also higher apoptosis in HsiI cells compared with HeLa cells. Both CIB and gamma treatment results G2/M arrest but unlike gamma CIB makes S-phase delay, implicating that gamma and CIB triggers different pathway after DNA damage. Cell death by CIB or by gamma increased up on knocking down of PARP-1 but increase is higher for high LET CIB compared with low LET gamma. Furthermore, expression level of PARP-1 controls the intensity of overall apoptosis in cells in post-irradiation condition. So, combination of PARP-1 inhibition with high LET CIB could be a promising tool to combat cancer. (author)

  14. Xeroderma Pigmentosum Group A Promotes Autophagy to Facilitate Cisplatin Resistance in Melanoma Cells through the Activation of PARP1.

    Science.gov (United States)

    Ge, Rui; Liu, Lin; Dai, Wei; Zhang, Weigang; Yang, Yuqi; Wang, Huina; Shi, Qiong; Guo, Sen; Yi, Xiuli; Wang, Gang; Gao, Tianwen; Luan, Qi; Li, Chunying

    2016-06-01

    Xeroderma pigmentosum group A (XPA), a key protein in the nucleotide excision repair pathway, has been shown to promote the resistance of tumor cells to chemotherapeutic drugs by facilitating the DNA repair process. However, the role of XPA in the resistance of melanoma to platinum-based drugs like cisplatin is largely unknown. In this study, we initially found that XPA was expressed at higher levels in cisplatin-resistant melanoma cells than in cisplatin-sensitive ones. Furthermore, the knockdown of XPA not only increased cellular apoptosis but also inhibited cisplatin-induced autophagy, which rendered the melanoma cells more sensitive to cisplatin. Moreover, we discovered that the increased XPA in resistant melanoma cells promoted poly(adenosine diphosphate-ribose) polymerase 1 (PARP1) activation and that the inhibition of PARP1 could attenuate the cisplatin-induced autophagy. Finally, we proved that the inhibition of PARP1 and the autophagy process made resistant melanoma cells more susceptible to cisplatin treatment. Our study shows that XPA can promote cell-protective autophagy in a DNA repair-independent manner by enhancing the activation of PARP1 in melanoma cells resistant to cisplatin and that the XPA-PARP1-mediated autophagy process can be targeted to overcome cisplatin resistance in melanoma chemotherapy. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  15. The inhibition of assembly of HIV-1 virus-like particles by 3-O-(3',3'-dimethylsuccinyl betulinic acid (DSB is counteracted by Vif and requires its Zinc-binding domain

    Directory of Open Access Journals (Sweden)

    Bouaziz Serge

    2008-12-01

    Full Text Available Abstract Background DSB, the 3-O-(3',3'dimethylsuccinyl derivative of betulinic acid, blocks the last step of protease-mediated processing of HIV-1 Gag precursor (Pr55Gag, which leads to immature, noninfectious virions. When administered to Pr55Gag-expressing insect cells (Sf9, DSB inhibits the assembly and budding of membrane-enveloped virus-like particles (VLP. In order to explore the possibility that viral factors could modulate the susceptibility to DSB of the VLP assembly process, several viral proteins were coexpressed individually with Pr55Gag in DSB-treated cells, and VLP yields assayed in the extracellular medium. Results Wild-type Vif (Vifwt restored the VLP production in DSB-treated cells to levels observed in control, untreated cells. DSB-counteracting effect was also observed with Vif mutants defective in encapsidation into VLP, suggesting that packaging and anti-DSB effect were separate functions in Vif. The anti-DSB effect was abolished for VifC133S and VifS116V, two mutants which lacked the zinc binding domain (ZBD formed by the four H108C114C133H139 coordinates with a Zn atom. Electron microscopic analysis of cells coexpressing Pr55Gag and Vifwt showed that a large proportion of VLP budded into cytoplasmic vesicles and were released from Sf9 cells by exocytosis. However, in the presence of mutant VifC133S or VifS116V, most of the VLP assembled and budded at the plasma membrane, as in control cells expressing Pr55Gag alone. Conclusion The function of HIV-1 Vif protein which negated the DSB inhibition of VLP assembly was independent of its packaging capability, but depended on the integrity of ZBD. In the presence of Vifwt, but not with ZBD mutants VifC133S and VifS116V, VLP were redirected to a vesicular compartment and egressed via the exocytic pathway.

  16. Telomere shortening is associated to TRF1 and PARP1 overexpression in Duchenne muscular dystrophy.

    Science.gov (United States)

    Aguennouz, M'Hammed; Vita, Gian Luca; Messina, Sonia; Cama, Annamaria; Lanzano, Natalia; Ciranni, Annamaria; Rodolico, Carmelo; Di Giorgio, Rosa Maria; Vita, Giuseppe

    2011-12-01

    Telomere shortening is thought to contribute to premature senescence of satellite cells in Duchenne muscular dystrophy (DMD) muscle. Telomeric repeat binding factor-1 (TRF1) and poly (ADP-ribose) polymerase-1 (PARP1) are proteins known to modulate telomerase reverse transcriptase (TERT) activity, which controls telomere elongation. Here we show that an age-dependent telomere shortening occurs in DMD muscles and is associated to overexpression of mRNA and protein levels of TRF1 and PARP1. TERT expression and activity are detectable in normal control muscles and they slightly increase in DMD. This is the first demonstration of TRF1 and PARP1 overexpression in DMD muscles. They can be directly involved in replicative senescence of satellite cells and/or in the pathogenetic cascade through a cross-talk with oxidative stress and inflammatory response. Modulation of these events by TRF1 or PARP1 inhibition might represent a novel strategy for treatment of DMD and other muscular dystrophies. Copyright © 2010 Elsevier Inc. All rights reserved.

  17. BZLF1 Expression of EBV is correlated with PARP1 Regulation on Nasopharyngeal Carcinoma Tissues

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    Wahyu nur laili fajri, Ahmad Rofi'i, Fatchiyah Fatchiyah

    2013-04-01

    Full Text Available Nasopharyngeal carcinomas (NPC is a cancer that arises in the epithelial tissue that covers the inside of the nasopharyngeal mucosa and nasopharynx. Infected Epstein Barr Virus (EBV cell in a latent infection associated with the expression of nine latent proteins. Latent Membrane Protein 1 (LMP1 is one of latent proteins, and mayor EBV oncoprotein, with functions including virus growth, and to activate BamHI-Z Leftward Reading Frame 1 (BZLF1-EBV, which can inhibit p53 to induce apoptotic resistance, metastasis, and immune modulation. The body will respond to the expansion of EBV infection with activation of Poly(ADP-ribosePolymerase-1 (PARP1. The objective of study is to observe the expression of BZLF1 and determine PARP1 regulation in nasopharyngeal tissues. NPC-T2, NPC-T3 and polyp tissues slides are from Ulin Hospital, Banjarmasin. To characterize the necrotic cells such as pyknosis, karyorrhexsis, and karyolysis, histological slides were stained by HE that the necrotic cells measured by using a BX-53 microscope (Olympus with CellSens Standard software. Tissues slides were stained by using immunofluorohistochemistry with EBV-BZLF1 antibody-Mouse anti-EBV monoclonal antibody against Goat anti-mouse IgG-FITC and anti-PARP1 antibody (MC-10 against Goat anti-mouse IgG labeled Rhodamin. The expression intensities were measured by Confocal Laser Scanning Microscope (Olympus. The percentage number of necrotic cells and BZLF1 and PARP1 expression intensity were analyzed using SPSS 16.0 by one-way ANOVA test with α = 0.05, beside that we use correlate and regression analyze. The research showed that the amount of karryorhexis higher than pyknosis and karyolysis in both tissues. BZLF1 expression 1.79 INT/sel (in polyp, 2.76 INT/sel (NPC Type 2 and 4.36 INT/sel (NPC Type 3, PARP1 expression 2.25 INT/sel (in polyp, 3.31 INT/sel (NPC Type 2, dan 5.93 INT/sel (NPC Type 3.The high of intensity of expression BZLF1 induced the increasing of PARP1 expression

  18. Parp1 protects against Aag-dependent alkylation-induced nephrotoxicity in a sex-dependent manner.

    Science.gov (United States)

    Calvo, Jennifer A; Allocca, Mariacarmela; Fake, Kimberly R; Muthupalani, Sureshkumar; Corrigan, Joshua J; Bronson, Roderick T; Samson, Leona D

    2016-07-19

    Nephrotoxicity is a common toxic side-effect of chemotherapeutic alkylating agents. Although the base excision repair (BER) pathway is essential in repairing DNA alkylation damage, under certain conditions the initiation of BER produces toxic repair intermediates that damage healthy tissues. We have shown that the alkyladenine DNA glycosylase, Aag (a.k.a. Mpg), an enzyme that initiates BER, mediates alkylation-induced whole-animal lethality and cytotoxicity in the pancreas, spleen, retina, and cerebellum, but not in the kidney. Cytotoxicity in both wild-type and Aag-transgenic mice (AagTg) was abrogated in the absence of Poly(ADP-ribose) polymerase-1 (Parp1). Here we report that Parp1-deficient mice expressing increased Aag (AagTg/Parp1-/-) develop sex-dependent kidney failure upon exposure to the alkylating agent, methyl methanesulfonate (MMS), and suffer increased whole-animal lethality compared to AagTg and wild-type mice. Macroscopic, histological, electron microscopic and immunohistochemical analyses revealed morphological kidney damage including dilated tubules, proteinaceous casts, vacuolation, collapse of the glomerular tuft, and deterioration of podocyte structure. Moreover, mice exhibited clinical signs of kidney disease indicating functional damage, including elevated blood nitrogen urea and creatinine, hypoproteinemia and proteinuria. Pharmacological Parp inhibition in AagTg mice also resulted in sensitivity to MMS-induced nephrotoxicity. These findings provide in vivo evidence that Parp1 modulates Aag-dependent MMS-induced nephrotoxicity in a sex-dependent manner and highlight the critical roles that Aag-initiated BER and Parp1 may play in determining the side-effects of chemotherapeutic alkylating agents.

  19. Mechanistic Links Between PARP, NAD, and Brain Inflammation After TBI

    Science.gov (United States)

    2015-10-01

    1 AWARD NUMBER: W81XWH-13-2-0091 TITLE: Mechanistic Links Between PARP, NAD , and Brain Inflammation After TBI PRINCIPAL INVESTIGATOR...COVERED 25 Sep 2014 - 24 Sep 2015 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Mechanistic Links Between PARP, NAD , and Brain Inflammation After TBI 5b. GRANT...efficacy of veliparib and NAD as agents for suppressing inflammation and improving outcomes after traumatic brain injury. The animal models include

  20. Synergetic Effects of PARP Inhibitor AZD2281 and Cisplatin in Oral Squamous Cell Carcinoma in Vitro and in Vivo

    Directory of Open Access Journals (Sweden)

    Masaaki Yasukawa

    2016-02-01

    Full Text Available Cisplatin is a commonly used chemotherapeutic drug for treatment of oral carcinoma, and combinatorial effects are expected to exert greater therapeutic efficacy compared with monotherapy. Poly(ADP-ribosylation is reported to be involved in a variety of cellular processes, such as DNA repair, cell death, telomere regulation, and genomic stability. Based on these properties, poly(ADP-ribose polymerase (PARP inhibitors are used for treatment of cancers, such as BRCA1/2 mutated breast and ovarian cancers, or certain solid cancers in combination with anti-cancer drugs. However, the effects on oral cancer have not been fully evaluated. In this study, we examined the effects of PARP inhibitor on the survival of human oral cancer cells in vitro and xenografted tumors derived from human oral cancer cells in vivo. In vitro effects were assessed by microculture tetrazolium and survival assays. The PARP inhibitor AZD2281 (olaparib showed synergetic effects with cisplatin in a dose-dependent manner. Combinatorial treatment with cisplatin and AZD2281 significantly inhibited xenografted tumor growth compared with single treatment of cisplatin or AZD2281. Histopathological analysis revealed that cisplatin and AZD2281 increased TUNEL-positive cells and decreased Ki67- and CD31-positive cells. These results suggest that PARP inhibitors have the potential to improve therapeutic strategies for oral cancer.

  1. Novel targeted therapeutics: inhibitors of MDM2, ALK and PARP

    Directory of Open Access Journals (Sweden)

    Hsueh Chung-Tsen

    2011-04-01

    Full Text Available Abstract We reviewed preclinical data and clinical development of MDM2 (murine double minute 2, ALK (anaplastic lymphoma kinase and PARP (poly [ADP-ribose] polymerase inhibitors. MDM2 binds to p53, and promotes degradation of p53 through ubiquitin-proteasome degradation. JNJ-26854165 and RO5045337 are 2 small-molecule inhibitors of MDM2 in clinical development. ALK is a transmembrane protein and a member of the insulin receptor tyrosine kinases. EML4-ALK fusion gene is identified in approximately 3-13% of non-small cell lung cancer (NSCLC. Early-phase clinical studies with Crizotinib, an ALK inhibitor, in NSCLC harboring EML4-ALK have demonstrated promising activity with high response rate and prolonged progression-free survival. PARPs are a family of nuclear enzymes that regulates the repair of DNA single-strand breaks through the base excision repair pathway. Randomized phase II study has shown adding PARP-1 inhibitor BSI-201 to cytotoxic chemotherapy improves clinical outcome in patients with triple-negative breast cancer. Olaparib, another oral small-molecule PARP inhibitor, demonstrated encouraging single-agent activity in patients with advanced breast or ovarian cancer. There are 5 other PARP inhibitors currently under active clinical investigation.

  2. Cells deficient in PARP-1 show an accelerated accumulation of DNA single strand breaks, but not AP sites, over the PARP-1-proficient cells exposed to MMS

    Energy Technology Data Exchange (ETDEWEB)

    Pachkowski, Brian F. [Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC (United States); Tano, Keizo [Research Reactor Institute, Kyoto University, Kumatori (Japan); Afonin, Valeriy [Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC (United States); Elder, Rhoderick H. [School of Environment and Life Sciences, University of Salford, Greater Manchester (United Kingdom); Takeda, Shunichi [Department of Radiation Genetics, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto (Japan); Watanabe, Masami [Research Reactor Institute, Kyoto University, Kumatori (Japan); Swenberg, James A. [Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC (United States); Nakamura, Jun, E-mail: ynakamur@email.unc.edu [Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC (United States)

    2009-12-01

    Poly(ADP-ribose) polymerase-1 (PARP-1) is a base excision repair (BER) protein that binds to DNA single strand breaks (SSBs) and subsequently synthesizes and transfers poly(ADP-ribose) polymers to various nuclear proteins. Numerous biochemical studies have implicated PARP-1 as a modulator of BER; however, the role of PARP-1 in BER in living cells remains unclear partly due to lack of accurate quantitation of BER intermediates existing in cells. Since DT40 cells, chicken B lymphocytes, naturally lack PARP-2, DT40 cells allow for the investigation of the PARP-1 null phenotype without confounding by PARP-2. To test the hypothesis that PARP-1 is necessary for efficient BER during methylmethane sulfonate (MMS) exposure in vertebrate cells, intact DT40 cells and their isogenic PARP-1 null counterparts were challenged with different exposure scenarios for phenotypic characterization. With chronic exposure, PARP-1 null cells exhibited sensitivity to MMS but with an acute exposure did not accumulate base lesions or AP sites to a greater extent than wild-type cells. However, an increase in SSB content in PARP-1 null cell DNA, as indicated by glyoxal gel electrophoresis under neutral conditions, suggested the presence of BER intermediates. These data suggest that during exposure, PARP-1 impacts the stage of BER after excision of the deoxyribosephosphate moiety from the 5' end of DNA strand breaks by polymerase {beta}.

  3. Cells deficient in PARP-1 show an accelerated accumulation of DNA single strand breaks, but not AP sites, over the PARP-1-proficient cells exposed to MMS.

    Science.gov (United States)

    Pachkowski, Brian F; Tano, Keizo; Afonin, Valeriy; Elder, Rhoderick H; Takeda, Shunichi; Watanabe, Masami; Swenberg, James A; Nakamura, Jun

    2009-12-01

    Poly(ADP-ribose) polymerase-1 (PARP-1) is a base excision repair (BER) protein that binds to DNA single strand breaks (SSBs) and subsequently synthesizes and transfers poly(ADP-ribose) polymers to various nuclear proteins. Numerous biochemical studies have implicated PARP-1 as a modulator of BER; however, the role of PARP-1 in BER in living cells remains unclear partly due to lack of accurate quantitation of BER intermediates existing in cells. Since DT40 cells, chicken B lymphocytes, naturally lack PARP-2, DT40 cells allow for the investigation of the PARP-1 null phenotype without confounding by PARP-2. To test the hypothesis that PARP-1 is necessary for efficient BER during methylmethane sulfonate (MMS) exposure in vertebrate cells, intact DT40 cells and their isogenic PARP-1 null counterparts were challenged with different exposure scenarios for phenotypic characterization. With chronic exposure, PARP-1 null cells exhibited sensitivity to MMS but with an acute exposure did not accumulate base lesions or AP sites to a greater extent than wild-type cells. However, an increase in SSB content in PARP-1 null cell DNA, as indicated by glyoxal gel electrophoresis under neutral conditions, suggested the presence of BER intermediates. These data suggest that during exposure, PARP-1 impacts the stage of BER after excision of the deoxyribosephosphate moiety from the 5' end of DNA strand breaks by polymerase beta.

  4. PARP-1 Variant Rs1136410 Confers Protection against Coronary Artery Disease in a Chinese Han Population: A Two-Stage Case-Control Study Involving 5643 Subjects

    Directory of Open Access Journals (Sweden)

    Xue-bin Wang

    2017-11-01

    Full Text Available Inhibition of poly(ADP-ribose polymerase (PARP may protect against coronary artery disease (CAD in animal models, and rs1136410, a non-synonymous single nucleotide polymorphism (SNP in PARP-1, has a potential impact on PARP activities in vitro. This two-stage case-control study, involving 2803 CAD patients and 2840 controls, aimed to investigate the associations of PARP-1 rs1136410 with CAD development, lipid levels, PARP activities, 8-hydroxy-2′-dexyguanosine (8-OHdG, and interleukin (IL-6 levels in a Chinese Han population. Assuming a recessive model, the variant genotype GG of SNP rs1136410 showed a significantly inverse association with CAD risk (adjusted odds ratio (OR = 0.73, P < 0.001, left main coronary artery (LMCA lesions (P = 0.003, vessel scores (P = 0.003, and modified Gensini scores (P < 0.001. There were significant correlations of SNP rs1136410 with higher levels of total cholesterol (TC and lower levels of high-density lipoprotein cholesterol (HDL-c. In gene-environment interaction analyses, participants with the variant genotype GG, but without smoking habit, type 2 diabetes mellitus, and hyperlipidemia, conferred an 84% (P < 0.001 decreased risk of CAD. The genotype-phenotype correlation analyses further supported the functional roles of SNP rs1136410 in decreasing PARP activities and 8-OHdG levels. Taken together, our data suggest that SNP rs1136410 may confer protection against CAD through modulation of PARP activities and gene-environment interactions in a Chinese Han population.

  5. New approaches of PARP-1 inhibitors in human lung cancer cells and cancer stem-like cells by some selected anthraquinone-derived small molecules.

    Directory of Open Access Journals (Sweden)

    Yu-Ru Lee

    Full Text Available Poly (ADP-ribose polymerase-1 (PARP-1 and telomerase, as well as DNA damage response pathways are targets for anticancer drug development, and specific inhibitors are currently under clinical investigation. The purpose of this work is to evaluate anticancer activities of anthraquinone-derived tricyclic and tetracyclic small molecules and their structure-activity relationships with PARP-1 inhibition in non-small cell lung cancer (NSCLC and NSCLC-overexpressing Oct4 and Nanog clone, which show high-expression of PARP-1 and more resistance to anticancer drug. We applied our library selected compounds to NCI's 60 human cancer cell-lines (NCI-60 in order to generate systematic profiling data. Based on our analysis, it is hypothesized that these drugs might be, directly and indirectly, target components to induce mitochondrial permeability transition and the release of pro-apoptotic factors as potential anti-NSCLC or PARP inhibitor candidates. Altogether, the most active NSC747854 showed its cytotoxicity and dose-dependent PARP inhibitory manner, thus it emerges as a promising structure for anti-cancer therapy with no significant negative influence on normal cells. Our studies present evidence that telomere maintenance should be taken into consideration in efforts not only to overcome drug resistance, but also to optimize the use of telomere-based therapeutics. These findings will be of great value to facilitate structure-based design of selective PARP inhibitors, in general, and telomerase inhibitors, in particular. Together, the data presented here expand our insight into the PARP inhibitors and support the resource-demanding lead optimization of structurally related small molecules for human cancer therapy.

  6. New Approaches of PARP-1 Inhibitors in Human Lung Cancer Cells and Cancer Stem-Like Cells by Some Selected Anthraquinone-Derived Small Molecules

    Science.gov (United States)

    Yu, Dah-Shyong; Huang, Kuo-Feng; Chou, Shih-Jie; Chen, Tsung-Chih; Lee, Chia-Chung; Chen, Chun-Liang; Chiou, Shih-Hwa; Huang, Hsu-Shan

    2013-01-01

    Poly (ADP-ribose) polymerase-1 (PARP-1) and telomerase, as well as DNA damage response pathways are targets for anticancer drug development, and specific inhibitors are currently under clinical investigation. The purpose of this work is to evaluate anticancer activities of anthraquinone-derived tricyclic and tetracyclic small molecules and their structure-activity relationships with PARP-1 inhibition in non-small cell lung cancer (NSCLC) and NSCLC-overexpressing Oct4 and Nanog clone, which show high-expression of PARP-1 and more resistance to anticancer drug. We applied our library selected compounds to NCI's 60 human cancer cell-lines (NCI-60) in order to generate systematic profiling data. Based on our analysis, it is hypothesized that these drugs might be, directly and indirectly, target components to induce mitochondrial permeability transition and the release of pro-apoptotic factors as potential anti-NSCLC or PARP inhibitor candidates. Altogether, the most active NSC747854 showed its cytotoxicity and dose-dependent PARP inhibitory manner, thus it emerges as a promising structure for anti-cancer therapy with no significant negative influence on normal cells. Our studies present evidence that telomere maintenance should be taken into consideration in efforts not only to overcome drug resistance, but also to optimize the use of telomere-based therapeutics. These findings will be of great value to facilitate structure-based design of selective PARP inhibitors, in general, and telomerase inhibitors, in particular. Together, the data presented here expand our insight into the PARP inhibitors and support the resource-demanding lead optimization of structurally related small molecules for human cancer therapy. PMID:23451039

  7. Analyzing structure–function relationships of artificial and cancer-associated PARP1 variants by reconstituting TALEN-generated HeLa PARP1 knock-out cells

    Science.gov (United States)

    Rank, Lisa; Veith, Sebastian; Gwosch, Eva C.; Demgenski, Janine; Ganz, Magdalena; Jongmans, Marjolijn C.; Vogel, Christopher; Fischbach, Arthur; Buerger, Stefanie; Fischer, Jan M.F.; Zubel, Tabea; Stier, Anna; Renner, Christina; Schmalz, Michael; Beneke, Sascha; Groettrup, Marcus; Kuiper, Roland P.; Bürkle, Alexander; Ferrando-May, Elisa; Mangerich, Aswin

    2016-01-01

    Genotoxic stress activates PARP1, resulting in the post-translational modification of proteins with poly(ADP-ribose) (PAR). We genetically deleted PARP1 in one of the most widely used human cell systems, i.e. HeLa cells, via TALEN-mediated gene targeting. After comprehensive characterization of these cells during genotoxic stress, we analyzed structure–function relationships of PARP1 by reconstituting PARP1 KO cells with a series of PARP1 variants. Firstly, we verified that the PARP1\\E988K mutant exhibits mono-ADP-ribosylation activity and we demonstrate that the PARP1\\L713F mutant is constitutively active in cells. Secondly, both mutants exhibit distinct recruitment kinetics to sites of laser-induced DNA damage, which can potentially be attributed to non-covalent PARP1–PAR interaction via several PAR binding motifs. Thirdly, both mutants had distinct functional consequences in cellular patho-physiology, i.e. PARP1\\L713F expression triggered apoptosis, whereas PARP1\\E988K reconstitution caused a DNA-damage-induced G2 arrest. Importantly, both effects could be rescued by PARP inhibitor treatment, indicating distinct cellular consequences of constitutive PARylation and mono(ADP-ribosyl)ation. Finally, we demonstrate that the cancer-associated PARP1 SNP variant (V762A) as well as a newly identified inherited PARP1 mutation (F304L\\V762A) present in a patient with pediatric colorectal carcinoma exhibit altered biochemical and cellular properties, thereby potentially supporting human carcinogenesis. Together, we establish a novel cellular model for PARylation research, by revealing strong structure–function relationships of natural and artificial PARP1 variants. PMID:27694308

  8. UPP mediated Diabetic Retinopathy via ROS/PARP and NF-κB inflammatory factor pathways.

    Science.gov (United States)

    Luo, D-W; Zheng, Z; Wang, H; Fan, Y; Chen, F; Sun, Y; Wang, W-J; Sun, T; Xu, X

    2015-01-01

    Diabetic retinopathy (DR) is a leading cause of blindness in adults at working age. Human diabetic retinopathy is characterized by the basement membrane thick, pericytes loss, microaneurysms formation, retina neovascularization and vitreous hemorrhage. To investigate whether UPP activated ROS/PARP and NF-κB inflammatory factor pathways in Diabetic Retinopathy, human retinal endothelial cells (HRECs) and rats with streptozotocin-induced diabetes were used to determine the effect of UPP on ROS generation, cell apoptosis, mitochondrial membrane potential (ΔΨm) and inflammatory factor protein expression, through flow cytometry assay, immunohistochemistry, Real-time PCR, Western blot analysis and ELISA. The levels of ROS and apoptosis and the expressions of UPP (Ub and E3) and inflammatory factor protein were increased in high glucose-induced HRECs and retina of diabetic rats, while ΔΨm was decreased. The UPP inhibitor and UbshRNA could attenuate these effects through inhibiting the pathway of ROS/PARP and the expression of NF-κB inflammatory factors, and the increased UPP was a result of high glucose-induced increase of ROS generation and NF-κBp65 expression, accompanied with the decrease of ΔΨm. Clinical study showed the overexpression of UPP and detachment of epiretinal membranes in proliferative DR (PDR) patients. It has been indicated that the pathogenic effect of UPP on DR was involved in the increase of ROS generation and NF-κB expression, which associated with the ROS/PARP and NF-κB inflammatory factor pathways. Our study supports a new insight for further application of UPP inhibitor in DR treatment.

  9. PARP-1 depletion in combination with carbon ion exposure significantly reduces MMPs activity and overall increases TIMPs expression in cultured HeLa cells

    International Nuclear Information System (INIS)

    Ghorai, Atanu; Sarma, Asitikantha; Chowdhury, Priyanka; Ghosh, Utpal

    2016-01-01

    Hadron therapy is an innovative technique where cancer cells are precisely killed leaving surrounding healthy cells least affected by high linear energy transfer (LET) radiation like carbon ion beam. Anti-metastatic effect of carbon ion exposure attracts investigators into the field of hadron biology, although details remain poor. Poly(ADP-ribose) polymerase-1 (PARP-1) inhibitors are well-known radiosensitizer and several PARP-1 inhibitors are in clinical trial. Our previous studies showed that PARP-1 depletion makes the cells more radiosensitive towards carbon ion than gamma. The purpose of the present study was to investigate combining effects of PARP-1 inhibition with carbon ion exposure to control metastatic properties in HeLa cells. Activities of matrix metalloproteinases-2, 9 (MMP-2, MMP-9) were measured using the gelatin zymography after 85 MeV carbon ion exposure or gamma irradiation (0- 4 Gy) to compare metastatic potential between PARP-1 knock down (HsiI) and control cells (H-vector - HeLa transfected with vector without shRNA construct). Expression of MMP-2, MMP-9, tissue inhibitor of MMPs such as TIMP-1, TIMP-2 and TIMP-3 were checked by immunofluorescence and western blot. Cell death by trypan blue, apoptosis and autophagy induction were studied after carbon ion exposure in each cell-type. The data was analyzed using one way ANOVA and 2-tailed paired-samples T-test. PARP-1 silencing significantly reduced MMP-2 and MMP-9 activities and carbon ion exposure further diminished their activities to less than 3 % of control H-vector. On the contrary, gamma radiation enhanced both MMP-2 and MMP-9 activities in H-vector but not in HsiI cells. The expression of MMP-2 and MMP-9 in H-vector and HsiI showed different pattern after carbon ion exposure. All three TIMPs were increased in HsiI, whereas only TIMP-1 was up-regulated in H-vector after irradiation. Notably, the expressions of all TIMPs were significantly higher in HsiI than H-vector at 4 Gy. Apoptosis was

  10. Evaluation of candidate biomarkers to predict cancer cell sensitivity or resistance to PARP-1 inhibitor treatment

    DEFF Research Database (Denmark)

    Oplustilova, L.; Wolanin, K.; Bartkova, J.

    2012-01-01

    combinations with camptothecin or ionizing radiation. Furthermore, monitoring pARsylation and Rad51 foci formation as surrogate markers for PARP activity and HR, respectively, supported their candidacy for biomarkers of PARP-1i responses. As to resistance mechanisms, we confrmed the role of the multidrug......(ADp-ribose) polymerase-1 (PARP-1), an enzyme critical for repair pathways alternative to HR. While promising, treatment with PARP-1 inhibitors (PARP-1i) faces some hurdles, including (1) acquired resistance, (2) search for other sensitizing, non-BRCA1/2 cancer defects and (3) lack of biomarkers to predict response...

  11. A phenanthrene derived PARP inhibitor is an extra-centrosomes de-clustering agent exclusively eradicating human cancer cells

    Directory of Open Access Journals (Sweden)

    Izraeli Shai

    2011-09-01

    Full Text Available Abstract Background Cells of most human cancers have supernumerary centrosomes. To enable an accurate chromosome segregation and cell division, these cells developed a yet unresolved molecular mechanism, clustering their extra centrosomes at two poles, thereby mimicking mitosis in normal cells. Failure of this bipolar centrosome clustering causes multipolar spindle structures and aberrant chromosomes segregation that prevent normal cell division and lead to 'mitotic catastrophe cell death'. Methods We used cell biology and biochemical methods, including flow cytometry, immunocytochemistry and live confocal imaging. Results We identified a phenanthrene derived PARP inhibitor, known for its activity in neuroprotection under stress conditions, which exclusively eradicated multi-centrosomal human cancer cells (mammary, colon, lung, pancreas, ovarian while acting as extra-centrosomes de-clustering agent in mitosis. Normal human proliferating cells (endothelial, epithelial and mesenchymal cells were not impaired. Despite acting as PARP inhibitor, the cytotoxic activity of this molecule in cancer cells was not attributed to PARP inhibition alone. Conclusion We identified a water soluble phenanthridine that exclusively targets the unique dependence of most human cancer cells on their supernumerary centrosomes bi-polar clustering for their survival. This paves the way for a new selective cancer-targeting therapy, efficient in a wide range of human cancers.

  12. Microglial activation induced by brain trauma is suppressed by post-injury treatment with a PARP inhibitor

    Directory of Open Access Journals (Sweden)

    d'Avila Joana C

    2012-02-01

    Full Text Available Abstract Background Traumatic brain injury (TBI induces activation of microglia. Activated microglia can in turn increase secondary injury and impair recovery. This innate immune response requires hours to days to become fully manifest, thus providing a clinically relevant window of opportunity for therapeutic intervention. Microglial activation is regulated in part by poly(ADP-ribose polymerase-1 (PARP-1. Inhibition of PARP-1 activity suppresses NF-kB-dependent gene transcription and thereby blocks several aspects of microglial activation. Here we evaluated the efficacy of a PARP inhibitor, INO-1001, in suppressing microglial activation after cortical impact in the rat. Methods Rats were subjected to controlled cortical impact and subsequently treated with 10 mg/kg of INO-1001 (or vehicle alone beginning 20 - 24 hours after the TBI. Brains were harvested at several time points for histological evaluation of inflammation and neuronal survival, using markers for microglial activation (morphology and CD11b expression, astrocyte activation (GFAP, and neuronal survival (NeuN. Rats were also evaluated at 8 weeks after TBI using measures of forelimb dexterity: the sticky tape test, cylinder test, and vermicelli test. Results Peak microglial and astrocyte activation was observed 5 to 7 days after this injury. INO-1001 significantly reduced microglial activation in the peri-lesion cortex and ipsilateral hippocampus. No rebound inflammation was observed in rats that were treated with INO-1001 or vehicle for 12 days followed by 4 days without drug. The reduced inflammation was associated with increased neuronal survival in the peri-lesion cortex and improved performance on tests of forelimb dexterity conducted 8 weeks after TBI. Conclusions Treatment with a PARP inhibitor for 12 days after TBI, with the first dose given as long as 20 hours after injury, can reduce inflammation and improve histological and functional outcomes.

  13. Arsenite-induced ROS/RNS generation causes zinc loss and inhibits the activity of poly(ADP-ribose) polymerase-1.

    Science.gov (United States)

    Wang, Feng; Zhou, Xixi; Liu, Wenlan; Sun, Xi; Chen, Chen; Hudson, Laurie G; Jian Liu, Ke

    2013-08-01

    Arsenic enhances the genotoxicity of other carcinogenic agents such as ultraviolet radiation and benzo[a]pyrene. Recent reports suggest that inhibition of DNA repair is an important aspect of arsenic cocarcinogenesis, and DNA repair proteins such as poly(ADP ribose) polymerase (PARP)-1 are direct molecular targets of arsenic. Although arsenic has been shown to generate reactive oxygen/nitrogen species (ROS/RNS), little is known about the role of arsenic-induced ROS/RNS in the mechanism underlying arsenic inhibition of DNA repair. We report herein that arsenite-generated ROS/RNS inhibits PARP-1 activity in cells. Cellular exposure to arsenite, as well as hydrogen peroxide and NONOate (nitric oxide donor), decreased PARP-1 zinc content, enzymatic activity, and PARP-1 DNA binding. Furthermore, the effects of arsenite on PARP-1 activity, DNA binding, and zinc content were partially reversed by the antioxidant ascorbic acid, catalase, and the NOS inhibitor, aminoguanidine. Most importantly, arsenite incubation with purified PARP-1 protein in vitro did not alter PARP-1 activity or DNA-binding ability, whereas hydrogen peroxide or NONOate retained PARP-1 inhibitory activity. These results strongly suggest that cellular generation of ROS/RNS plays an important role in arsenite inhibition of PARP-1 activity, leading to the loss of PARP-1 DNA-binding ability and enzymatic activity. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Cyber terrorism prevention and counteraction workshop review

    NARCIS (Netherlands)

    Pastukhov, O.M.

    2011-01-01

    A NATO Advanced Training Course (ATC ) on Cyber Terrorism Prevention and Counteraction workshop, held in Kiev on September 27-29, 2010, allowed the participants to share their experiences with experts from Ukraine, a Partnership for Peace country. The participants exchanged their ideas on the ways

  15. Effects of 3-AB on PARP expression of Hela cells and apoptosis and cell cycle progression of Hela cells after X-rays irradiation

    International Nuclear Information System (INIS)

    Du Xiang; Zhao Hongguang; Guo Wei; Gong Shouliang; Wang Wen

    2007-01-01

    Objective: To study the changes of apoptosis and cell cycle progression of Hela cells after the poly (ADP- ribose) polymerase (PARP) was inhibited by its inhibitor 3-aminobenzamid (3-AB) and the mechanisms of PARP interaction with Hela cells damaged by irradiation. Methods: Hela cell line was used. Flow cytometry (FCM) was used to examine the PARP expression of control and 3 AB groups at 0, 2, 4, 8, 12 h alter administration with 5 mmol·L -1 3-AB. The percentage of apoptotic cells and cell cycle progression ol control, irradiation, 3-AB plus irradiation groups were measured with FCM at 2, 8, 12, 24 h after exposure to 2 Gy irradiation following administration with 5 mmol·L -1 3-AB. Results: The percentage of Hela cells with positive expression of PARP protein decreased after administration with 3-AB and there was significant difference between 3-AB plus irradiation group and control group (P 2 cells in the 3-AB plus irradiation group were lower than those in the irradiation group (P 2 arrest induced by irradiation. (authors)

  16. A New Nanobody-Based Biosensor to Study Endogenous PARP1 In Vitro and in Live Human Cells.

    Directory of Open Access Journals (Sweden)

    Andrea Buchfellner

    Full Text Available Poly(ADP-ribose polymerase 1 (PARP1 is a key player in DNA repair, genomic stability and cell survival and it emerges as a highly relevant target for cancer therapies. To deepen our understanding of PARP biology and mechanisms of action of PARP1-targeting anti-cancer compounds, we generated a novel PARP1-affinity reagent, active both in vitro and in live cells. This PARP1-biosensor is based on a PARP1-specific single-domain antibody fragment (~ 15 kDa, termed nanobody, which recognizes the N-terminus of human PARP1 with nanomolar affinity. In proteomic approaches, immobilized PARP1 nanobody facilitates quantitative immunoprecipitation of functional, endogenous PARP1 from cellular lysates. For cellular studies, we engineered an intracellularly functional PARP1 chromobody by combining the nanobody coding sequence with a fluorescent protein sequence. By following the chromobody signal, we were for the first time able to monitor the recruitment of endogenous PARP1 to DNA damage sites in live cells. Moreover, tracing of the sub-nuclear translocation of the chromobody signal upon treatment of human cells with chemical substances enables real-time profiling of active compounds in high content imaging. Due to its ability to perform as a biosensor at the endogenous level of the PARP1 enzyme, the novel PARP1 nanobody is a unique and versatile tool for basic and applied studies of PARP1 biology and DNA repair.

  17. A New Nanobody-Based Biosensor to Study Endogenous PARP1 In Vitro and in Live Human Cells.

    Science.gov (United States)

    Buchfellner, Andrea; Yurlova, Larisa; Nüske, Stefan; Scholz, Armin M; Bogner, Jacqueline; Ruf, Benjamin; Zolghadr, Kourosh; Drexler, Sophie E; Drexler, Guido A; Girst, Stefanie; Greubel, Christoph; Reindl, Judith; Siebenwirth, Christian; Romer, Tina; Friedl, Anna A; Rothbauer, Ulrich

    2016-01-01

    Poly(ADP-ribose) polymerase 1 (PARP1) is a key player in DNA repair, genomic stability and cell survival and it emerges as a highly relevant target for cancer therapies. To deepen our understanding of PARP biology and mechanisms of action of PARP1-targeting anti-cancer compounds, we generated a novel PARP1-affinity reagent, active both in vitro and in live cells. This PARP1-biosensor is based on a PARP1-specific single-domain antibody fragment (~ 15 kDa), termed nanobody, which recognizes the N-terminus of human PARP1 with nanomolar affinity. In proteomic approaches, immobilized PARP1 nanobody facilitates quantitative immunoprecipitation of functional, endogenous PARP1 from cellular lysates. For cellular studies, we engineered an intracellularly functional PARP1 chromobody by combining the nanobody coding sequence with a fluorescent protein sequence. By following the chromobody signal, we were for the first time able to monitor the recruitment of endogenous PARP1 to DNA damage sites in live cells. Moreover, tracing of the sub-nuclear translocation of the chromobody signal upon treatment of human cells with chemical substances enables real-time profiling of active compounds in high content imaging. Due to its ability to perform as a biosensor at the endogenous level of the PARP1 enzyme, the novel PARP1 nanobody is a unique and versatile tool for basic and applied studies of PARP1 biology and DNA repair.

  18. A New Nanobody-Based Biosensor to Study Endogenous PARP1 In Vitro and in Live Human Cells

    Science.gov (United States)

    Nüske, Stefan; Scholz, Armin M.; Bogner, Jacqueline; Ruf, Benjamin; Zolghadr, Kourosh; Drexler, Sophie E.; Drexler, Guido A.; Girst, Stefanie; Greubel, Christoph; Reindl, Judith; Siebenwirth, Christian; Romer, Tina; Friedl, Anna A.; Rothbauer, Ulrich

    2016-01-01

    Poly(ADP-ribose) polymerase 1 (PARP1) is a key player in DNA repair, genomic stability and cell survival and it emerges as a highly relevant target for cancer therapies. To deepen our understanding of PARP biology and mechanisms of action of PARP1-targeting anti-cancer compounds, we generated a novel PARP1-affinity reagent, active both in vitro and in live cells. This PARP1-biosensor is based on a PARP1-specific single-domain antibody fragment (~ 15 kDa), termed nanobody, which recognizes the N-terminus of human PARP1 with nanomolar affinity. In proteomic approaches, immobilized PARP1 nanobody facilitates quantitative immunoprecipitation of functional, endogenous PARP1 from cellular lysates. For cellular studies, we engineered an intracellularly functional PARP1 chromobody by combining the nanobody coding sequence with a fluorescent protein sequence. By following the chromobody signal, we were for the first time able to monitor the recruitment of endogenous PARP1 to DNA damage sites in live cells. Moreover, tracing of the sub-nuclear translocation of the chromobody signal upon treatment of human cells with chemical substances enables real-time profiling of active compounds in high content imaging. Due to its ability to perform as a biosensor at the endogenous level of the PARP1 enzyme, the novel PARP1 nanobody is a unique and versatile tool for basic and applied studies of PARP1 biology and DNA repair. PMID:26950694

  19. Poly(ADP-ribose) polymerase-1 inhibits ATM kinase activity in DNA damage response

    International Nuclear Information System (INIS)

    Watanabe, Fumiaki; Fukazawa, Hidesuke; Masutani, Mitsuko; Suzuki, Hiroshi; Teraoka, Hirobumi; Mizutani, Shuki; Uehara, Yoshimasa

    2004-01-01

    DNA double-strand breaks (DSB) mobilize DNA-repair machinery and cell cycle checkpoint by activating the ataxia-telangiectasia (A-T) mutated (ATM). Here we show that ATM kinase activity is inhibited by poly(ADP-ribose) polymerase-1 (PARP-1) in vitro. It was shown by biochemical fractionation procedure that PARP-1 as well as ATM increases at chromatin level after induction of DSB with neocarzinostatin (NCS). Phosphorylation of histone H2AX on serine 139 and p53 on serine 15 in Parp-1 knockout (Parp-1 -/- ) mouse embryonic fibroblasts (MEF) was significantly induced by NCS treatment compared with MEF derived from wild-type (Parp-1 +/+ ) mouse. NCS-induced phosphorylation of histone H2AX on serine 139 in Parp-1 -/- embryonic stem cell (ES) clones was also higher than that in Parp-1 +/+ ES clone. Furthermore, in vitro, PARP-1 inhibited phosphorylation of p53 on serine 15 and 32 P-incorporation into p53 by ATM in a DNA-dependent manner. These results suggest that PARP-1 negatively regulates ATM kinase activity in response to DSB

  20. PARP2 Is the Predominant Poly(ADP-Ribose Polymerase in Arabidopsis DNA Damage and Immune Responses.

    Directory of Open Access Journals (Sweden)

    Junqi Song

    2015-05-01

    Full Text Available Poly (ADP-ribose polymerases (PARPs catalyze the transfer of multiple poly(ADP-ribose units onto target proteins. Poly(ADP-ribosylation plays a crucial role in a variety of cellular processes including, most prominently, auto-activation of PARP at sites of DNA breaks to activate DNA repair processes. In humans, PARP1 (the founding and most characterized member of the PARP family accounts for more than 90% of overall cellular PARP activity in response to DNA damage. We have found that, in contrast with animals, in Arabidopsis thaliana PARP2 (At4g02390, rather than PARP1 (At2g31320, makes the greatest contribution to PARP activity and organismal viability in response to genotoxic stresses caused by bleomycin, mitomycin C or gamma-radiation. Plant PARP2 proteins carry SAP DNA binding motifs rather than the zinc finger domains common in plant and animal PARP1 proteins. PARP2 also makes stronger contributions than PARP1 to plant immune responses including restriction of pathogenic Pseudomonas syringae pv. tomato growth and reduction of infection-associated DNA double-strand break abundance. For poly(ADP-ribose glycohydrolase (PARG enzymes, we find that Arabidopsis PARG1 and not PARG2 is the major contributor to poly(ADP-ribose removal from acceptor proteins. The activity or abundance of PARP2 is influenced by PARP1 and PARG1. PARP2 and PARP1 physically interact with each other, and with PARG1 and PARG2, suggesting relatively direct regulatory interactions among these mediators of the balance of poly(ADP-ribosylation. As with plant PARP2, plant PARG proteins are also structurally distinct from their animal counterparts. Hence core aspects of plant poly(ADP-ribosylation are mediated by substantially different enzymes than in animals, suggesting the likelihood of substantial differences in regulation.

  1. Unfolding of core nucleosomes by PARP-1 revealed by spFRET microscopy

    Directory of Open Access Journals (Sweden)

    Daniel Sultanov

    2017-01-01

    Full Text Available DNA accessibility to various protein complexes is essential for various processes in the cell and is affected by nucleosome structure and dynamics. Protein factor PARP-1 (poly(ADP-ribose polymerase 1 increases the accessibility of DNA in chromatin to repair proteins and transcriptional machinery, but the mechanism and extent of this chromatin reorganization are unknown. Here we report on the effects of PARP-1 on single nucleosomes revealed by spFRET (single-particle Förster Resonance Energy Transfer microscopy. PARP-1 binding to a double-strand break in the vicinity of a nucleosome results in a significant increase of the distance between the adjacent gyres of nucleosomal DNA. This partial uncoiling of the entire nucleosomal DNA occurs without apparent loss of histones and is reversed after poly(ADP-ribosylation of PARP-1. Thus PARP-1-nucleosome interactions result in reversible, partial uncoiling of the entire nucleosomal DNA.

  2. Acquisition of Relative Interstrand Crosslinker Resistance and PARP Inhibitor Sensitivity in Fanconi Anemia Head and Neck Cancers.

    Science.gov (United States)

    Lombardi, Anne J; Hoskins, Elizabeth E; Foglesong, Grant D; Wikenheiser-Brokamp, Kathryn A; Wiesmüller, Lisa; Hanenberg, Helmut; Andreassen, Paul R; Jacobs, Allison J; Olson, Susan B; Keeble, Winifred W; Hays, Laura E; Wells, Susanne I

    2015-04-15

    Fanconi anemia is an inherited disorder associated with a constitutional defect in the Fanconi anemia DNA repair machinery that is essential for resolution of DNA interstrand crosslinks. Individuals with Fanconi anemia are predisposed to formation of head and neck squamous cell carcinomas (HNSCC) at a young age. Prognosis is poor, partly due to patient intolerance of chemotherapy and radiation requiring dose reduction, which may lead to early recurrence of disease. Using HNSCC cell lines derived from the tumors of patients with Fanconi anemia, and murine HNSCC cell lines derived from the tumors of wild-type and Fancc(-/-) mice, we sought to define Fanconi anemia-dependent chemosensitivity and DNA repair characteristics. We utilized DNA repair reporter assays to explore the preference of Fanconi anemia HNSCC cells for non-homologous end joining (NHEJ). Surprisingly, interstrand crosslinker (ICL) sensitivity was not necessarily Fanconi anemia-dependent in human or murine cell systems. Our results suggest that the increased Ku-dependent NHEJ that is expected in Fanconi anemia cells did not mediate relative ICL resistance. ICL exposure resulted in increased DNA damage sensing and repair by PARP in Fanconi anemia-deficient cells. Moreover, human and murine Fanconi anemia HNSCC cells were sensitive to PARP inhibition, and sensitivity of human cells was attenuated by Fanconi anemia gene complementation. The observed reliance upon PARP-mediated mechanisms reveals a means by which Fanconi anemia HNSCCs can acquire relative resistance to the ICL-based chemotherapy that is a foundation of HNSCC treatment, as well as a potential target for overcoming chemoresistance in the chemosensitive individual. ©2015 American Association for Cancer Research.

  3. Combination strategy of PARP inhibitor with antioxidant prevent bioenergetic deficits and inflammatory changes in CCI-induced neuropathy.

    Science.gov (United States)

    Komirishetty, Prashanth; Areti, Aparna; Gogoi, Ranadeep; Sistla, Ramakrishna; Kumar, Ashutosh

    2017-02-01

    Neuropathic pain, a debilitating pain condition and the underlying pathogenic mechanisms are complex and interwoven amongst each other and still there is scant information available regarding therapies which promise to treat the condition. Evidence indicate that oxidative/nitrosative stress induced poly (ADP-ribose) polymerase (PARP) overactivation initiate neuroinflammation and bioenergetic crisis culminating into neurodegenerative changes following nerve injury. Hence, we investigated the therapeutic effect of combining an antioxidant, quercetin and a PARP inhibitor, 4-amino 1, 8-naphthalimide (4-ANI) on the hallmark deficits induced by chronic constriction injury (CCI) of sciatic nerve in rats. Quercetin (25 mg/kg, p.o.) and 4-ANI (3 mg/kg, p.o.) were administered either alone or in combination for 14 days to examine sciatic functional index, allodynia and hyperalgesia using walking track analysis, Von Frey, acetone spray and hot plate tests respectively. Malondialdehyde, nitrite and glutathione levels were estimated to detect oxidative/nitrosative stress; mitochondrial membrane potential and cytochrome c oxidase activity to assess mitochondrial function; NAD & ATP levels to examine the bioenergetic status and levels of inflammatory markers were evaluated in ipsilateral sciatic nerve. Quercetin and 4-ANI alone improved the pain behaviour and biochemical alterations but the combination therapy demonstrated an appreciable reversal of CCI-induced changes. Nitrotyrosine and Poly ADP-Ribose (PAR) immunopositivity was decreased and nuclear factor erythroid 2-related factor (Nrf-2) levels were increased significantly in micro-sections of the sciatic nerve and dorsal root ganglion (DRG) of treatment group. These results suggest that simultaneous inhibition of oxidative stress-PARP activation cascade may potentially be useful strategies for management of trauma induced neuropathic pain. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Poly(ADP-ribose polymerase (PARP-1 is not involved in DNA double-strand break recovery

    Directory of Open Access Journals (Sweden)

    Fernet Marie

    2003-07-01

    Full Text Available Abstract Background The cytotoxicity and the rejoining of DNA double-strand breaks induced by γ-rays, H2O2 and neocarzinostatin, were investigated in normal and PARP-1 knockout mouse 3T3 fibroblasts to determine the role of poly(ADP-ribose polymerase (PARP-1 in DNA double-strand break repair. Results PARP-1-/- were considerably more sensitive than PARP-1+/+ 3T3s to induced cell kill by γ-rays and H2O2. However, the two cell lines did not show any significant difference in the susceptibility to neocarzinostatin below 1.5 nM drug. Restoration of PARP-1 expression in PARP-1-/- 3T3s by retroviral transfection of the full PARP-1 cDNA did not induce any change in neocarzinostatin response. Moreover the incidence and the rejoining kinetics of neocarzinostatin-induced DNA double-strand breaks were identical in PARP-1+/+ and PARP-1-/- 3T3s. Poly(ADP-ribose synthesis following γ-rays and H2O2 was observed in PARP-1-proficient cells only. In contrast neocarzinostatin, even at supra-lethal concentration, was unable to initiate PARP-1 activation yet it induced H2AX histone phosphorylation in both PARP1+/+ and PARP-1-/- 3T3s as efficiently as γ-rays and H2O2. Conclusions The results show that PARP-1 is not a major determinant of DNA double-strand break recovery with either strand break rejoining or cell survival as an endpoint. Even though both PARP-1 and ATM activation are major determinants of the cell response to γ-rays and H2O2, data suggest that PARP-1-dependent poly(ADP-ribose synthesis and ATM-dependent H2AX phosphorylation, are not inter-related in the repair pathway of neocarzinostatin-induced DNA double-strand breaks.

  5. ROS-induced DNA damage and PARP-1 are required for optimal induction of starvation-induced autophagy

    DEFF Research Database (Denmark)

    Rodríguez-Vargas, José Manuel; Ruiz-Magaña, María José; Ruiz-Ruiz, Carmen

    2012-01-01

    , leading to ATP depletion (an early event after nutrient deprivation). The absence of PARP-1 blunted AMPK activation and prevented the complete loss of mTOR activity, leading to a delay in autophagy. PARP-1 depletion favors apoptosis in starved cells, suggesting a pro-survival role of autophagy and PARP-1...

  6. Cediranib, a pan-VEGFR inhibitor, and olaparib, a PARP inhibitor, in combination therapy for high grade serous ovarian cancer.

    Science.gov (United States)

    Ivy, S Percy; Liu, Joyce F; Lee, Jung-Min; Matulonis, Ursula A; Kohn, Elise C

    2016-01-01

    An estimated 22,000 women are diagnosed annually with ovarian cancer in the United States. Initially chemo-sensitive, recurrent disease ultimately becomes chemoresistant and may kill ~14,000 women annually. Molecularly targeted therapy with cediranib (AZD2171), a vascular endothelial growth factor receptor (VEGFR)-1, 2, and 3 signaling blocker, and olaparib (AZD2281), a poly(adenosine diphosphate [ADP]-ribose) polymerase (PARP) inhibitor, administered orally in combination has shown anti-tumor activity in the treatment of high grade serous ovarian cancer (HGSOC). This combination has the potential to change the treatment of HGSOC. Preclinical and clinical studies of single agent cediranib and olaparib or their combination are reviewed. Data are presented from peer-reviewed published manuscripts, completed and ongoing early phase clinical trials registered in ClinicalTrials.gov, National Cancer Institute-sponsored clinical trials, and related recent abstracts. Advances in the treatment of HGSOC that improve progression-free and overall survival have proven elusive despite examination of molecularly targeted therapy. HGSOC patients with deleterious germline or somatic mutations in BRCA1 or BRCA2 (BRCAm) are most responsive to PARP inhibitors (PARPi). PARPi combined with angiogenesis inhibition improved anti-cancer response and duration in both BRCAm and BRCA wild type HGSOC patients, compared to olaparib single agent treatment, demonstrating therapeutic chemical and contextual synthetic lethality.

  7. Regulation of FOXO1-mediated transcription and cell proliferation by PARP-1

    Energy Technology Data Exchange (ETDEWEB)

    Sakamaki, Jun-ichi; Daitoku, Hiroaki; Yoshimochi, Kenji [Center for Tsukuba Advanced Research Alliance, Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Miwa, Masanao [Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, Nagahama, Shiga 526-0829 (Japan); Fukamizu, Akiyoshi, E-mail: akif@tara.tsukuba.ac.jp [Center for Tsukuba Advanced Research Alliance, Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan)

    2009-05-08

    Forkhead box O (FOXO) transcription factors play an important role in a wide range of biological processes, including cell cycle control, apoptosis, detoxification of reactive oxygen species, and gluconeogenesis through regulation of gene expression. In this study, we demonstrated that PARP-1 functions as a negative regulator of FOXO1. We showed that PARP-1 directly binds to and poly(ADP-ribosyl)ates FOXO1 protein. PARP-1 represses FOXO1-mediated expression of cell cycle inhibitor p27{sup Kip1} gene. Notably, poly(ADP-ribosyl)ation activity was not required for the repressive effect of PARP-1 on FOXO1 function. Furthermore, knockdown of PARP-1 led to a decrease in cell proliferation in a manner dependent on FOXO1 function. Chromatin immunoprecipitation experiments confirmed that PARP-1 is recruited to the p27{sup Kip1} gene promoter through a binding to FOXO1. These results suggest that PARP-1 acts as a corepressor for FOXO1, which could play an important role in proper cell proliferation by regulating p27{sup Kip1} gene expression.

  8. Autoimmune response to PARP and BRCA1/BRCA2 in cancer

    Science.gov (United States)

    Zhu, Qing; Han, Su-Xia; Zhou, Cong-Ya; Cai, Meng-Jiao; Dai, Li-Ping; Zhang, Jian-Ying

    2015-01-01

    Purpose To determine the role of autoantibodies to PARP1 and BRCA1/BRCA2 which were involved in the synthetic lethal interaction in cancer. Methods Enzyme-Linked Immunosorbent Assay (ELISA) was used to detect autoantibodies to PARP1 and BRCA1/BRCA2 in 618 serum samples including 131 from breast cancer, 94 from lung cancer, 34 from ovarian cancer, 107 from prostate cancer, 76 from liver cancer, 41 from pancreatic cancer and 135 from normal individuals. The positive sera with ELISA were confirmed by Western blot. Immunohistochemistry was used to examine the expression of PARP1 and BRCA1/BRCA2 in breast cancer. Results Autoantibody frequency to PARP1, BRCA1, and BRCA2 in cancer varied from 0% to 50%. When the sera from cancer patients were tested for the presence of autoantibodies to PARP1 and BRCA1/BRCA2, the autoantibody responses slightly decreased and the positive autoantibody reactions varied from 0% to 50.0%. This was significantly higher autoantibody responses to PARP1 and BRCA1/BRCA2 (especially to PARP1 and BRCA1) in ovarian cancer and breast cancer compared to normal control sera (P cancer was different (P cancers have different profiles of autoantibodies. The autoantibodies to proteins involving the synthetic lethal interactions would be novel serological biomarker in some selective cancers. PMID:25865228

  9. The anti-oxidative transcription factor Nuclear factor E2 related factor-2 (Nrf2) counteracts TGF-β1 mediated growth inhibition of pancreatic ductal epithelial cells -Nrf2 as determinant of pro-tumorigenic functions of TGF-β1

    International Nuclear Information System (INIS)

    Genrich, Geeske; Kruppa, Marcus; Lenk, Lennart; Helm, Ole; Broich, Anna; Freitag-Wolf, Sandra; Röcken, Christoph; Sipos, Bence; Schäfer, Heiner; Sebens, Susanne

    2016-01-01

    Nrf2-mediated cell survival was predominantly based on an enhanced proliferative activity. Accordingly, expression of p21 expression along with expression of phospho-p38 and phospho-Smad3 was diminished whereas Erk-phosphorylation was enhanced under these conditions. Overall, our data demonstrate that Nrf2 being elevated in early precursor lesions counteracts the growth inhibiting function of TGF-β1 already in benign and premalignant pancreatic ductal epithelial cells. This could represent one fundamental mechanism underlying the functional switch of both- TGF-β1 and Nrf2 – which may manifest already in early stages of PDAC development. The online version of this article (doi:10.1186/s12885-016-2191-7) contains supplementary material, which is available to authorized users

  10. PARP-1 serves as a novel molecular marker for hepatocellular carcinoma in a Southern Chinese Zhuang population.

    Science.gov (United States)

    Li, Jiatong; Dou, Dongwei; Li, Ping; Luo, Wenqi; Lv, Wenxin; Zhang, Chengdong; Song, Xiaowei; Yang, Yuan; Zhang, Yuening; Xu, Yanzhen; Xiao, Feifan; Wei, Yan; Qin, Jian; Li, Hongtao; Yang, Xiaoli

    2017-07-01

    PARP-1 (poly(ADP-ribose) polymerase-1) plays an important role in tumorigenesis. Since its effects on different populations are varied, this study investigated the impact of PARP-1 on primary hepatocellular carcinoma in a Southern Chinese Zhuang population. We assessed the global PARP-1 messenger RNA expression in patients with hepatocellular carcinoma using The Cancer Genome Atlas dataset. Increased PARP-1 expression, related to alpha-fetoprotein level, was observed. The area under the receiver operating characteristic curve value was 0.833. Kaplan-Meier survival curves indicated that higher PARP-1 expression was not correlated with poorer overall survival and recurrence-free survival. In a Zhuang population, PARP-1 messenger RNA and protein levels were increased in the hepatocellular carcinoma tissue and its adjacent liver tissues as assessed by quantitative polymerase chain reaction, immunohistochemistry, and western blotting. Higher PARP-1 level was associated with a higher tumor stage (p  0.05). Further analysis suggested that H2AX, a PARP-1 protein interaction partner, was coordinated with PARP-1 in hepatocellular carcinoma tumorigenesis. Overall, some new characteristics of PARP-1 expression were noted in the Zhuang population. PARP-1 is a novel promising diagnostic marker for hepatocellular carcinoma in the Southern Chinese Zhuang population.

  11. PARP-2 regulates cell cycle-related genes through histone deacetylation and methylation independently of poly(ADP-ribosyl)ation

    International Nuclear Information System (INIS)

    Liang, Ya-Chen; Hsu, Chiao-Yu; Yao, Ya-Li; Yang, Wen-Ming

    2013-01-01

    Highlights: ► PARP-2 acts as a transcription co-repressor independently of PARylation activity. ► PARP-2 recruits HDAC5, 7, and G9a and generates repressive chromatin. ► PARP-2 is recruited to the c-MYC promoter by DNA-binding factor YY1. ► PARP-2 represses cell cycle-related genes and alters cell cycle progression. -- Abstract: Poly(ADP-ribose) polymerase-2 (PARP-2) catalyzes poly(ADP-ribosyl)ation (PARylation) and regulates numerous nuclear processes, including transcription. Depletion of PARP-2 alters the activity of transcription factors and global gene expression. However, the molecular action of how PARP-2 controls the transcription of target promoters remains unclear. Here we report that PARP-2 possesses transcriptional repression activity independently of its enzymatic activity. PARP-2 interacts and recruits histone deacetylases HDAC5 and HDAC7, and histone methyltransferase G9a to the promoters of cell cycle-related genes, generating repressive chromatin signatures. Our findings propose a novel mechanism of PARP-2 in transcriptional regulation involving specific protein–protein interactions and highlight the importance of PARP-2 in the regulation of cell cycle progression

  12. Discourse on corruption counteraction in network trade

    Directory of Open Access Journals (Sweden)

    Leonid A. Zhigun

    2015-12-01

    Full Text Available Objective to determine the specific forms of corruption and promising methods to counteract corruption in network trade. Methods the combination of inductive observations comparisons generalizations facts and trends of corruption in network trade with a logical analytical deduction of economic theories and the corruption concept are the basis of the study and provide an opportunity on the one hand to assess the level of compliance of theoretical concepts of corruption with the practice and on the other handnbsp to determine their applicability to organize opposition and create conditions to prevent its occurrence to summarize the features of corruption in the form of a kickback the discourse method was applied in this work. Results on the basis of theoretical provisions and facts of corruption in trade it is proved that it has typical characteristics of corruption in commercial and nonprofit organizations. The key reasons are identified why corruption occurs in trade. Among them supply of poor quality goods at inflated prices leading to bribery in the form of laquopersonal bonusraquo to administrator of the trading organization when selling goods by an unscrupulous supplier and also supply goods to the trade organizations which will not buy without kickback. Most of these corrupt deals are carried out by natural monopolies in the form of state and municipal procurement. In some cases the kickback is the argument stimulating the decision to introduce new and advanced technologies. The factors that lead to corruption in trade are listed and reasonable methods to counteract it are grounded allowing to create conditions for its eradication in other branches of business as well. Scientific novelty for the first time a generalization has been made about the deficit as the driving force in the mechanism when the bribegivers and bribetakers change places. Practical significance the main provisions and conclusions of the article can be used in the

  13. Sialyltransferase activity probably counteracts that of sialidase as ...

    African Journals Online (AJOL)

    Sialyltransferase activity probably counteracts that of sialidase as one of the possible mechanisms of natural recovery or stabilization of erythrocyte mass in trypanosome-infected animals - A perspective.

  14. Differential expression of PARP1 mRNA in leucocytes of patients ...

    Indian Academy of Sciences (India)

    P. 2011 Differential expression of PARP1 mRNA in leucocytes of patients with Down's syndrome. J. Genet. ... of Alzheimer disease at an earlier age than subjects with- ... family and personal informed consent. .... In effect, they report that.

  15. Deficiency in Poly(ADP-ribose Polymerase-1 (PARP-1 Accelerates Aging and Spontaneous Carcinogenesis in Mice

    Directory of Open Access Journals (Sweden)

    Tatiana S. Piskunova

    2008-01-01

    Full Text Available Genetic and biochemical studies have shown that PARP-1 and poly(ADP-ribosylation play an important role in DNA repair, genomic stability, cell death, inflammation, telomere maintenance, and suppressing tumorigenesis, suggesting that the homeostasis of poly(ADP-ribosylation and PARP-1 may also play an important role in aging. Here we show that PARP-1−/− mice exhibit a reduction of life span and a significant increase of population aging rate. Analysis of noninvasive parameters, including body weight gain, body temperature, estrous function, behavior, and a number of biochemical indices suggests the acceleration of biological aging in PARP-1−/− mice. The incidence of spontaneous tumors in both PARP-1−/− and PARP-1+/+ groups is similar; however, malignant tumors including uterine tumors, lung adenocarcinomas and hepatocellular carcinomas, develop at a significantly higher frequency in PARP-1−/− mice than PARP-1+/+ mice (72% and 49%, resp.; < .05. In addition, spontaneous tumors appear earlier in PARP-1−/− mice compared to the wild type group. Histopathological studies revealed a wide spectrum of tumors in uterus, ovaries, liver, lungs, mammary gland, soft tissues, and lymphoid organs in both groups of the mice. These results demonstrate that inactivation of DNA repair gene PARP-1 in mice leads to acceleration of aging, shortened life span, and increased spontaneous carcinogenesis.

  16. Exposure to nature counteracts aggression after depletion.

    Science.gov (United States)

    Wang, Yan; She, Yihan; Colarelli, Stephen M; Fang, Yuan; Meng, Hui; Chen, Qiuju; Zhang, Xin; Zhu, Hongwei

    2018-01-01

    Acts of self-control are more likely to fail after previous exertion of self-control, known as the ego depletion effect. Research has shown that depleted participants behave more aggressively than non-depleted participants, especially after being provoked. Although exposure to nature (e.g., a walk in the park) has been predicted to replenish resources common to executive functioning and self-control, the extent to which exposure to nature may counteract the depletion effect on aggression has yet to be determined. The present study investigated the effects of exposure to nature on aggression following depletion. Aggression was measured by the intensity of noise blasts participants delivered to an ostensible opponent in a competition reaction-time task. As predicted, an interaction occurred between depletion and environmental manipulations for provoked aggression. Specifically, depleted participants behaved more aggressively in response to provocation than non-depleted participants in the urban condition. However, provoked aggression did not differ between depleted and non-depleted participants in the natural condition. Moreover, within the depletion condition, participants in the natural condition had lower levels of provoked aggression than participants in the urban condition. This study suggests that a brief period of nature exposure may restore self-control and help depleted people regain control over aggressive urges. © 2017 Wiley Periodicals, Inc.

  17. ISG15 counteracts Listeria monocytogenes infection

    Science.gov (United States)

    Radoshevich, Lilliana; Impens, Francis; Ribet, David; Quereda, Juan J; Nam Tham, To; Nahori, Marie-Anne; Bierne, Hélène; Dussurget, Olivier; Pizarro-Cerdá, Javier; Knobeloch, Klaus-Peter; Cossart, Pascale

    2015-01-01

    ISG15 is an interferon-stimulated, linear di-ubiquitin-like protein, with anti-viral activity. The role of ISG15 during bacterial infection remains elusive. We show that ISG15 expression in nonphagocytic cells is dramatically induced upon Listeria infection. Surprisingly this induction can be type I interferon independent and depends on the cytosolic surveillance pathway, which senses bacterial DNA and signals through STING, TBK1, IRF3 and IRF7. Most importantly, we observed that ISG15 expression restricts Listeria infection in vitro and in vivo. We made use of stable isotope labeling in tissue culture (SILAC) to identify ISGylated proteins that could be responsible for the protective effect. Strikingly, infection or overexpression of ISG15 leads to ISGylation of ER and Golgi proteins, which correlates with increased secretion of cytokines known to counteract infection. Together, our data reveal a previously uncharacterized ISG15-dependent restriction of Listeria infection, reinforcing the view that ISG15 is a key component of the innate immune response. DOI: http://dx.doi.org/10.7554/eLife.06848.001 PMID:26259872

  18. Coronavirus gene 7 counteracts host defenses and modulates virus virulence.

    Directory of Open Access Journals (Sweden)

    Jazmina L G Cruz

    2011-06-01

    Full Text Available Transmissible gastroenteritis virus (TGEV genome contains three accessory genes: 3a, 3b and 7. Gene 7 is only present in members of coronavirus genus a1, and encodes a hydrophobic protein of 78 aa. To study gene 7 function, a recombinant TGEV virus lacking gene 7 was engineered (rTGEV-Δ7. Both the mutant and the parental (rTGEV-wt viruses showed the same growth and viral RNA accumulation kinetics in tissue cultures. Nevertheless, cells infected with rTGEV-Δ7 virus showed an increased cytopathic effect caused by an enhanced apoptosis mediated by caspase activation. Macromolecular synthesis analysis showed that rTGEV-Δ7 virus infection led to host translational shut-off and increased cellular RNA degradation compared with rTGEV-wt infection. An increase of eukaryotic translation initiation factor 2 (eIF2α phosphorylation and an enhanced nuclease, most likely RNase L, activity were observed in rTGEV-Δ7 virus infected cells. These results suggested that the removal of gene 7 promoted an intensified dsRNA-activated host antiviral response. In protein 7 a conserved sequence motif that potentially mediates binding to protein phosphatase 1 catalytic subunit (PP1c, a key regulator of the cell antiviral defenses, was identified. We postulated that TGEV protein 7 may counteract host antiviral response by its association with PP1c. In fact, pull-down assays demonstrated the interaction between TGEV protein 7, but not a protein 7 mutant lacking PP1c binding motif, with PP1. Moreover, the interaction between protein 7 and PP1 was required, during the infection, for eIF2α dephosphorylation and inhibition of cell RNA degradation. Inoculation of newborn piglets with rTGEV-Δ7 and rTGEV-wt viruses showed that rTGEV-Δ7 virus presented accelerated growth kinetics and pathology compared with the parental virus. Overall, the results indicated that gene 7 counteracted host cell defenses, and modified TGEV persistence increasing TGEV survival. Therefore, the

  19. Rapamycin inhibits poly(ADP-ribosyl)ation in intact cells

    International Nuclear Information System (INIS)

    Fahrer, Joerg; Wagner, Silvia; Buerkle, Alexander; Koenigsrainer, Alfred

    2009-01-01

    Rapamycin is an immunosuppressive drug, which inhibits the mammalian target of rapamycin (mTOR) kinase activity inducing changes in cell proliferation. Synthesis of poly(ADP-ribose) (PAR) is an immediate cellular response to genotoxic stress catalyzed mostly by poly(ADP-ribose) polymerase 1 (PARP-1), which is also controlled by signaling pathways. Therefore, we investigated whether rapamycin affects PAR production. Strikingly, rapamycin inhibited PAR synthesis in living fibroblasts in a dose-dependent manner as monitored by immunofluorescence. PARP-1 activity was then assayed in vitro, revealing that down-regulation of cellular PAR production by rapamycin was apparently not due to competitive PARP-1 inhibition. Further studies showed that rapamycin did not influence the cellular NAD pool and the activation of PARP-1 in extracts of pretreated fibroblasts. Collectively, our data suggest that inhibition of cellular PAR synthesis by rapamycin is mediated by formation of a detergent-sensitive complex in living cells, and that rapamycin may have a potential as therapeutic PARP inhibitor.

  20. Rapamycin inhibits poly(ADP-ribosyl)ation in intact cells

    Energy Technology Data Exchange (ETDEWEB)

    Fahrer, Joerg, E-mail: joerg.fahrer@uni-ulm.de [Molecular Toxicology Group, Department of Biology, University of Konstanz (Germany); Wagner, Silvia [Clinic of General, Visceral- and Transplantation Surgery, ZMF, University Hospital Tuebingen (Germany); Buerkle, Alexander [Molecular Toxicology Group, Department of Biology, University of Konstanz (Germany); Koenigsrainer, Alfred [Clinic of General, Visceral- and Transplantation Surgery, ZMF, University Hospital Tuebingen (Germany)

    2009-08-14

    Rapamycin is an immunosuppressive drug, which inhibits the mammalian target of rapamycin (mTOR) kinase activity inducing changes in cell proliferation. Synthesis of poly(ADP-ribose) (PAR) is an immediate cellular response to genotoxic stress catalyzed mostly by poly(ADP-ribose) polymerase 1 (PARP-1), which is also controlled by signaling pathways. Therefore, we investigated whether rapamycin affects PAR production. Strikingly, rapamycin inhibited PAR synthesis in living fibroblasts in a dose-dependent manner as monitored by immunofluorescence. PARP-1 activity was then assayed in vitro, revealing that down-regulation of cellular PAR production by rapamycin was apparently not due to competitive PARP-1 inhibition. Further studies showed that rapamycin did not influence the cellular NAD pool and the activation of PARP-1 in extracts of pretreated fibroblasts. Collectively, our data suggest that inhibition of cellular PAR synthesis by rapamycin is mediated by formation of a detergent-sensitive complex in living cells, and that rapamycin may have a potential as therapeutic PARP inhibitor.

  1. MicroRNAs Modulate Oxidative Stress in Hypertension through PARP-1 Regulation

    Directory of Open Access Journals (Sweden)

    Douglas F. Dluzen

    2017-01-01

    Full Text Available Oxidative stress is thought to contribute to aging and age-related diseases, such as cardiovascular and neurodegenerative diseases, and is a risk factor for systemic arterial hypertension. Previously, we reported differential mRNA and microRNA (miRNA expression between African American (AA and white women with hypertension. Here, we found that the poly-(ADP-ribose polymerase 1 (PARP-1, a DNA damage sensor protein involved in DNA repair and other cellular processes, is upregulated in AA women with hypertension. To explore this mechanism, we identified two miRNAs, miR-103a-2-5p and miR-585-5p, that are differentially expressed with hypertension and were predicted to target PARP1. Through overexpression of each miRNA-downregulated PARP-1 mRNA and protein levels and using heterologous luciferase reporter assays, we demonstrate that miR-103a-2-5p and miR-585-5p regulate PARP1 through binding within the coding region. Given the important role of PARP-1 in DNA repair, we assessed whether overexpression of miR-103a-2-5p or miR-585-5p affected DNA damage and cell survival. Overexpression of these miRNAs enhanced DNA damage and decreased both cell survival and colony formation. These findings highlight the role for PARP-1 in regulating oxidative DNA damage in hypertension and identify important new miRNA regulators of PARP-1 expression. These insights may provide additional avenues to understand hypertension health disparities.

  2. Phase I, Dose-Escalation, Two-Part Trial of the PARP Inhibitor Talazoparib in Patients with Advanced Germline BRCA1/2 Mutations and Selected Sporadic Cancers.

    Science.gov (United States)

    de Bono, Johann; Ramanathan, Ramesh K; Mina, Lida; Chugh, Rashmi; Glaspy, John; Rafii, Saeed; Kaye, Stan; Sachdev, Jasgit; Heymach, John; Smith, David C; Henshaw, Joshua W; Herriott, Ashleigh; Patterson, Miranda; Curtin, Nicola J; Byers, Lauren Averett; Wainberg, Zev A

    2017-06-01

    Talazoparib inhibits PARP catalytic activity, trapping PARP1 on damaged DNA and causing cell death in BRCA1/2 -mutated cells. We evaluated talazoparib therapy in this two-part, phase I, first-in-human trial. Antitumor activity, MTD, pharmacokinetics, and pharmacodynamics of once-daily talazoparib were determined in an open-label, multicenter, dose-escalation study (NCT01286987). The MTD was 1.0 mg/day, with an elimination half-life of 50 hours. Treatment-related adverse events included fatigue (26/71 patients; 37%) and anemia (25/71 patients; 35%). Grade 3 to 4 adverse events included anemia (17/71 patients; 24%) and thrombocytopenia (13/71 patients; 18%). Sustained PARP inhibition was observed at doses ≥0.60 mg/day. At 1.0 mg/day, confirmed responses were observed in 7 of 14 (50%) and 5 of 12 (42%) patients with BRCA mutation-associated breast and ovarian cancers, respectively, and in patients with pancreatic and small cell lung cancer. Talazoparib demonstrated single-agent antitumor activity and was well tolerated in patients at the recommended dose of 1.0 mg/day. Significance: In this clinical trial, we show that talazoparib has single-agent antitumor activity and a tolerable safety profile. At its recommended phase II dose of 1.0 mg/day, confirmed responses were observed in patients with BRCA mutation-associated breast and ovarian cancers and in patients with pancreatic and small cell lung cancer. Cancer Discov; 7(6); 620-9. ©2017 AACR. This article is highlighted in the In This Issue feature, p. 539 . ©2017 American Association for Cancer Research.

  3. Overcoming Resistance of Cancer Cells to PARP-1 Inhibitors with Three Different Drug Combinations.

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    Michal Yalon

    Full Text Available Inhibitors of poly[ADP-ribose] polymerase 1 (PARPis show promise for treatment of cancers which lack capacity for homologous recombination repair (HRR. However, new therapeutic strategies are required in order to overcome innate and acquired resistance to these drugs and thus expand the array of cancers that could benefit from them. We show that human cancer cell lines which respond poorly to ABT-888 (a PARPi, become sensitive to it when co-treated with vorinostat (a histone deacetylase inhibitor (HDACi. Vorinostat also sensitized PARPis insensitive cancer cell lines to 6-thioguanine (6-TG-a drug that targets PARPis sensitive cells. The sensitizing effect of vorinostat was associated with increased phosphorylation of eukaryotic initiation factor (eIF 2α which in and of itself increases the sensitivity of cancer cells to ABT-888. Importantly, these drug combinations did not affect survival of normal fibroblasts and breast cells, and significantly increased the inhibition of xenograft tumor growth relative to each drug alone, without affecting the mice weight or their liver and kidney function. Our results show that combination of vorinostat and ABT-888 could potentially prove useful for treatment of cancer with innate resistance to PARPis due to active HRR machinery, while the combination of vorinostat and 6-TG could potentially overcome innate or acquired resistance to PARPis due to secondary or reversal BRCA mutations, to decreased PARP-1 level or to increased expression of multiple drug resistant proteins. Importantly, drugs which increase phosphorylation of eIF2α may mimic the sensitizing effect of vorinostat on cellular response to PARPis or to 6-TG, without activating all of its downstream effectors.

  4. Structure/function analysis of PARP-1 in oxidative and nitrosative stress-induced monomeric ADPR formation.

    Directory of Open Access Journals (Sweden)

    Ben Buelow

    2009-07-01

    Full Text Available Poly adenosine diphosphate-ribose polymerase-1 (PARP-1 is a multifunctional enzyme that is involved in two major cellular responses to oxidative and nitrosative (O/N stress: detection and response to DNA damage via formation of protein-bound poly adenosine diphosphate-ribose (PAR, and formation of the soluble 2(nd messenger monomeric adenosine diphosphate-ribose (mADPR. Previous studies have delineated specific roles for several of PARP-1's structural domains in the context of its involvement in a DNA damage response. However, little is known about the relationship between the mechanisms through which PARP-1 participates in DNA damage detection/response and those involved in the generation of monomeric ADPR. To better understand the relationship between these events, we undertook a structure/function analysis of PARP-1 via reconstitution of PARP-1 deficient DT40 cells with PARP-1 variants deficient in catalysis, DNA binding, auto-PARylation, and PARP-1's BRCT protein interaction domain. Analysis of responses of the respective reconstituted cells to a model O/N stressor indicated that PARP-1 catalytic activity, DNA binding, and auto-PARylation are required for PARP-dependent mADPR formation, but that BRCT-mediated interactions are dispensable. As the BRCT domain is required for PARP-dependent recruitment of XRCC1 to sites of DNA damage, these results suggest that DNA repair and monomeric ADPR 2(nd messenger generation are parallel mechanisms through which PARP-1 modulates cellular responses to O/N stress.

  5. PARPi-FL - a Fluorescent PARP1 Inhibitor for Glioblastoma Imaging

    Directory of Open Access Journals (Sweden)

    Christopher P. Irwin

    2014-05-01

    Full Text Available New intravital optical imaging technologies have revolutionized our understanding of mammalian biology and continue to evolve rapidly. However, there are only a limited number of imaging probes available to date. In this study, we investigated in mouse models of glioblastoma whether a fluorescent small molecule inhibitor of the DNA repair enzyme PARP1, PARPi-FL, can be used as an imaging agent to detect glioblastomas in vivo. We demonstrated that PARPi-FL has appropriate biophysical properties, low toxicity at concentrations used for imaging, high stability in vivo, and accumulates selectively in glioblastomas due to high PARP1 expression. Importantly, subcutaneous and orthotopic glioblastoma xenografts were imaged with high contrast clearly defining tumor tissue from normal surrounding tissue. This research represents a step toward exploring and developing PARPi-FL as an optical intraoperative imaging agent for PARP1 in the clinic.

  6. Human mass balance study and metabolite profiling of 14C-niraparib, a novel poly(ADP-Ribose) polymerase (PARP)-1 and PARP-2 inhibitor, in patients with advanced cancer

    NARCIS (Netherlands)

    van Andel, Lotte; Zhang, Z; Lu, S.; Kansra, V; Agarwal, S.; Hughes, L.; Tibben, M.; Gebretensae, A.; Lucas, L.; Hillebrand, Michel J X; Rosing, H.; Schellens, J H M|info:eu-repo/dai/nl/073926272; Beijnen, J H|info:eu-repo/dai/nl/071919570

    2017-01-01

    Niraparib is an investigational oral, once daily, selective poly(ADP-Ribose) polymerase (PARP)-1 and PARP-2 inhibitor. In the pivotal Phase 3 NOVA/ENGOT/OV16 study, niraparib met its primary endpoint of improving progression-free survival (PFS) for adult patients with recurrent, platinum sensitive,

  7. PARP inhibitors protect against sex- and AAG-dependent alkylation-induced neural degeneration.

    Science.gov (United States)

    Allocca, Mariacarmela; Corrigan, Joshua J; Fake, Kimberly R; Calvo, Jennifer A; Samson, Leona D

    2017-09-15

    Alkylating agents are commonly used to treat cancer. Although base excision repair (BER) is a major pathway for repairing DNA alkylation damage, under certain conditions, the initiation of BER produces toxic repair intermediates that damage healthy tissues. The initiation of BER by the alkyladenine DNA glycosylase (AAG, a.k.a. MPG) can mediate alkylation-induced cytotoxicity in specific cells in the retina and cerebellum of male mice. Cytotoxicity in both wild-type and Aag -transgenic ( AagTg ) mice is abrogated in the absence of Poly(ADP-ribose) polymerase-1 (PARP1). Here, we tested whether PARP inhibitors can also prevent alkylation-induced retinal and cerebellar degeneration in male and female WT and AagTg mice. Importantly, we found that WT mice display sex-dependent alkylation-induced retinal damage (but not cerebellar damage), with WT males being more sensitive than females. Accordingly, estradiol treatment protects males against alkylation-induced retinal degeneration. In AagTg male and female mice, the alkylation-induced tissue damage in both the retina and cerebellum is exacerbated and the sex difference in the retina is abolished. PARP inhibitors, much like Parp1 gene deletion, protect against alkylation-induced AAG-dependent neuronal degeneration in WT and AagTg mice, regardless of the gender, but their efficacy in preventing alkylation-induced neuronal degeneration depends on PARP inhibitor characteristics and doses. The recent surge in the use of PARP inhibitors in combination with cancer chemotherapeutic alkylating agents might represent a powerful tool for obtaining increased therapeutic efficacy while avoiding the collateral effects of alkylating agents in healthy tissues.

  8. Edaravone abrogates LPS-induced behavioral anomalies, neuroinflammation and PARP-1.

    Science.gov (United States)

    Sriram, Chandra Shaker; Jangra, Ashok; Gurjar, Satendra Singh; Mohan, Pritam; Bezbaruah, Babul Kumar

    2016-02-01

    Poly(ADP-ribose) polymerase-1 (PARP-1) is a DNA nick-sensor enzyme that functions at the center of cellular stress response and affects the immune system at several key points, and thus modulates inflammatory diseases. Our previous study demonstrated that lipopolysaccharide (LPS)-induced depressive-like behavior in mice can be ameliorated by 3-aminobenzamide, which is a PARP-1 inhibitor. In the present study we've examined the effect of a free radical scavenger, edaravone pretreatment against LPS-induced anxiety and depressive-like behavior as well as various hippocampal biochemical parameters including PARP-1. Male Swiss albino mice were treated with edaravone (3 & 10mg/kgi.p.) once daily for 14days. On the 14th day 30min after edaravone treatment mice were challenged with LPS (1mg/kgi.p.). After 3h and 24h of LPS administration we've tested mice for anxiety and depressive-like behaviors respectively. Western blotting analysis of PARP-1 in hippocampus was carried out after 12h of LPS administration. Moreover, after 24h of LPS administration serum corticosterone, hippocampal BDNF, oxido-nitrosative stress and pro-inflammatory cytokines were estimated by ELISA. Results showed that pretreatment of edaravone (10mg/kg) ameliorates LPS-induced anxiety and depressive-like behavior. Western blotting analysis showed that LPS-induced anomalous expression of PARP-1 significantly reverses by the pretreatment of edaravone (10mg/kg). Biochemical analyses revealed that LPS significantly diminishes BDNF, increases pro-inflammatory cytokines and oxido-nitrosative stress in the hippocampus. However, pretreatment with edaravone (10mg/kg) prominently reversed all these biochemical alterations. Our study emphasized that edaravone pretreatment prevents LPS-induced anxiety and depressive-like behavior, mainly by impeding the inflammation, oxido-nitrosative stress and PARP-1 overexpression. Copyright © 2015. Published by Elsevier Inc.

  9. Rucaparib: a novel PARP inhibitor for BRCA advanced ovarian cancer

    Directory of Open Access Journals (Sweden)

    Colombo I

    2018-03-01

    Full Text Available Ilaria Colombo, Stephanie Lheureux, Amit Manulal Oza Division of Medical Oncology and Hematology, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada Abstract: Rucaparib is a potent small-molecule inhibitor of poly (ADP-ribose polymerase (PARP proteins (PARP-1, PARP-2 and PARP-3 that play an important role in repairing DNA damage and maintaining genomic stability. Tumors with mutations in BRCA1/2 or other homologous recombination deficiency (HRD genes are particularly sensitive to PARP inhibitors because of “synthetic lethality”, whereby a therapeutic agent can take advantage of an intrinsic weakness in DNA repair. Rucaparib has been investigated in several preclinical and clinical studies showing promising activity in BRCA-mutant and BRCA–wild-type epithelial ovarian cancers (EOCs. Dose-escalation Phase I studies have established the recommended Phase II dose to be 600 mg twice a day for oral rucaparib. Phase II and III studies have defined its role as treatment for BRCA-mutant recurrent high-grade EOC and as maintenance treatment for platinum-sensitive relapsed EOC following response to platinum-based chemotherapy. Genomic loss of heterozygosity has also been investigated as a potential signature of HRD and as a potential predictive biomarker of response. Treatment-induced adverse events (AEs have been observed in almost all patients treated with rucaparib, but mainly lower grade; with the most common being nausea, vomiting, asthenia/fatigue, anemia and transient transaminitis. The majority of AEs occurred early in treatment, were transient and have been easily managed with supportive treatment, dose interruption or discontinuation. This review will analyze the results of clinical trials investigating efficacy and safety of rucaparib in patients with ovarian cancer. Keywords: rucaparib, ovarian cancer, BRCA mutations, homologous recombination deficiency, maintenance treatment, PARP inhibitor

  10. The Prognostic Value of BRCA1 and PARP Expression in Epithelial Ovarian Carcinoma

    DEFF Research Database (Denmark)

    Hjortkjær, Mette; Waldstrøm, Marianne; Jakobsen, Anders

    2017-01-01

    BRCA1/2 mutation status in epithelial ovarian cancer (EOC) presently relies on genetic testing which is resource consuming. Immunohistochemistry is cheap, fairly reproducible, and may identify gene product alterations due to both germline and somatic mutations and other defects along the BRCA gene...... tissue from 170 patients with EOC was stained immunohistochemically with BRCA1 and PARP antibodies. Semiquantitative analyses were performed to determine loss of, equivocal, and retained BRCA1 and high versus low PARP protein expression. These parameters were analyzed for relation with patient...

  11. A Gene Expression Profile of BRCAness That Predicts for Responsiveness to Platinum and PARP Inhibitors

    Science.gov (United States)

    2017-02-01

    affecting the function of Fanconi Anemia (FA) genes ( FANCA /B/C/D2/E/F/G/I/J/L/M, PALB2) or DNA damage response genes involved in HR 5 (ATM, ATR...Award Number: W81XWH-10-1-0585 TITLE: A Gene Expression Profile of BRCAness That Predicts for Responsiveness to Platinum and PARP Inhibitors...To) 15 July 2010 – 2 Nov.2016 4. TITLE AND SUBTITLE A Gene Expression Profile of BRCAness That Predicts for Responsiveness to Platinum and PARP

  12. Rev1 contributes to proper mitochondrial function via the PARP-NAD(+)-SIRT1-PGC1 alpha axis

    DEFF Research Database (Denmark)

    Fakouri, Nima Borhan; Durhuus, Jon Ambaek; Regnell, Christine Elisabeth

    2017-01-01

    (ADP) ribose polymerase 1 (PARP1) activity, low endogenous NAD+, low expression of SIRT1 and PGC1α and low adenosine monophosphate (AMP)-activated kinase (AMPK) activity. We conclude that replication stress via Rev1-deficiency contributes to metabolic stress caused by compromized mitochondrial function via...... the PARP-NAD+-SIRT1-PGC1α axis....

  13. The role of hnRPUL1 involved in DNA damage response is related to PARP1.

    Directory of Open Access Journals (Sweden)

    Zehui Hong

    Full Text Available Heterogeneous nuclear ribonucleoprotein U-like 1 (hnRPUL1 -also known as adenovirus early region 1B-associated proteins 5 (E1B-AP5 - plays a role in RNA metabolism. Recently, hnRPUL1 has also been shown to be involved in DNA damage response, but the function of hnRPUL1 in response to DNA damage remains unclear. Here, we have demonstrated that hnRPUL1 is associated with PARP1 and recruited to DNA double-strand breaks (DSBs sites in a PARP1-mediated poly (ADP-ribosyl ation dependent manner. In turn, hnRPUL1 knockdown enhances the recruitment of PARP1 to DSBs sites. Specifically, we showed that hnRPUL1 is also implicated in the transcriptional regulation of PARP1 gene. Thus, we propose hnRPUL1 as a new component related to PARP1 in DNA damage response and repair.

  14. Baseline clinical predictors of antitumor response to the PARP inhibitor olaparib in germline BRCA1/2 mutated patients with advanced ovarian cancer.

    Science.gov (United States)

    Rafii, Saeed; Gourley, Charlie; Kumar, Rajiv; Geuna, Elena; Ern Ang, Joo; Rye, Tzyvia; Chen, Lee-May; Shapira-Frommer, Ronnie; Friedlander, Michael; Matulonis, Ursula; De Greve, Jacques; Oza, Amit M; Banerjee, Susana; Molife, L Rhoda; Gore, Martin E; Kaye, Stan B; Yap, Timothy A

    2017-07-18

    The PARP inhibitor olaparib was recently granted Food and Drug Administration (FDA) accelerated approval in patients with advanced BRCA1/2 mutation ovarian cancer. However, antitumor responses are observed in only approximately 40% of patients and the impact of baseline clinical factors on response to treatment remains unclear. Although platinum sensitivity has been suggested as a marker of response to PARP inhibitors, patients with platinum-resistant disease still respond to olaparib. 108 patients with advanced BRCA1/2 mutation ovarian cancers were included. The interval between the end of the most recent platinum chemotherapy and PARPi (PTPI) was used to predict response to olaparib independent of conventional definition of platinum sensitivity. RECIST complete response (CR) and partial response (PR) rates were 35% in patients with platinum-sensitive versus 13% in platinum-resistant (p<0.005). Independent of platinum sensitivity status, the RECIST CR/PR rates were 42% in patients with PTPI greater than 52 weeks and 18% in patients with PTPI less than 52 weeks (p=0.016). No association was found between baseline clinical factors such as FIGO staging, debulking surgery, BRCA1 versus BRCA2 mutations, prior history of breast cancer and prior chemotherapy for breast cancer, and the response to olaparib. We conducted an international multicenter retrospective study to investigate the association between baseline clinical characteristics of patients with advanced BRCA1/2 mutation ovarian cancers from eight different cancer centers and their antitumor response to olaparib. PTPI may be used to refine the prediction of response to PARP inhibition based on the conventional categorization of platinum sensitivity.

  15. PARP inhibitor rucaparib induces changes in NAD levels in cells and liver tissues as assessed by MRS.

    Science.gov (United States)

    Almeida, Gilberto S; Bawn, Carlo M; Galler, Martin; Wilson, Ian; Thomas, Huw D; Kyle, Suzanne; Curtin, Nicola J; Newell, David R; Maxwell, Ross J

    2017-09-01

    Poly(adenosine diphosphate ribose) polymerases (PARPs) are multifunctional proteins which play a role in many cellular processes. Namely, PARP1 and PARP2 have been shown to be involved in DNA repair, and therefore are valid targets in cancer treatment with PARP inhibitors, such as rucaparib, currently in clinical trials. Proton magnetic resonance spectroscopy ( 1 H-MRS) was used to study the impact of rucaparib in vitro and ex vivo in liver tissue from mice, via quantitative analysis of nicotinamide adenosine diphosphate (NAD + ) spectra, to assess the potential of MRS as a biomarker of the PARP inhibitor response. SW620 (colorectal) and A2780 (ovarian) cancer cell lines, and PARP1 wild-type (WT) and PARP1 knock-out (KO) mice, were treated with rucaparib, temozolomide (methylating agent) or a combination of both drugs. 1 H-MRS spectra were obtained from perchloric acid extracts of tumour cells and mouse liver. Both cell lines showed an increase in NAD + levels following PARP inhibitor treatment in comparison with temozolomide treatment. Liver extracts from PARP1 WT mice showed a significant increase in NAD + levels after rucaparib treatment compared with untreated mouse liver, and a significant decrease in NAD + levels in the temozolomide-treated group. The combination of rucaparib and temozolomide did not prevent the NAD + depletion caused by temozolomide treatment. The 1 H-MRS results show that NAD + levels can be used as a biomarker of PARP inhibitor and methylating agent treatments, and suggest that in vivo measurement of NAD + would be valuable. Copyright © 2017 John Wiley & Sons, Ltd.

  16. Aag DNA glycosylase promotes alkylation-induced tissue damage mediated by Parp1.

    Science.gov (United States)

    Calvo, Jennifer A; Moroski-Erkul, Catherine A; Lake, Annabelle; Eichinger, Lindsey W; Shah, Dharini; Jhun, Iny; Limsirichai, Prajit; Bronson, Roderick T; Christiani, David C; Meira, Lisiane B; Samson, Leona D

    2013-04-01

    Alkylating agents comprise a major class of front-line cancer chemotherapeutic compounds, and while these agents effectively kill tumor cells, they also damage healthy tissues. Although base excision repair (BER) is essential in repairing DNA alkylation damage, under certain conditions, initiation of BER can be detrimental. Here we illustrate that the alkyladenine DNA glycosylase (AAG) mediates alkylation-induced tissue damage and whole-animal lethality following exposure to alkylating agents. Aag-dependent tissue damage, as observed in cerebellar granule cells, splenocytes, thymocytes, bone marrow cells, pancreatic β-cells, and retinal photoreceptor cells, was detected in wild-type mice, exacerbated in Aag transgenic mice, and completely suppressed in Aag⁻/⁻ mice. Additional genetic experiments dissected the effects of modulating both BER and Parp1 on alkylation sensitivity in mice and determined that Aag acts upstream of Parp1 in alkylation-induced tissue damage; in fact, cytotoxicity in WT and Aag transgenic mice was abrogated in the absence of Parp1. These results provide in vivo evidence that Aag-initiated BER may play a critical role in determining the side-effects of alkylating agent chemotherapies and that Parp1 plays a crucial role in Aag-mediated tissue damage.

  17. Aag DNA glycosylase promotes alkylation-induced tissue damage mediated by Parp1.

    Directory of Open Access Journals (Sweden)

    Jennifer A Calvo

    2013-04-01

    Full Text Available Alkylating agents comprise a major class of front-line cancer chemotherapeutic compounds, and while these agents effectively kill tumor cells, they also damage healthy tissues. Although base excision repair (BER is essential in repairing DNA alkylation damage, under certain conditions, initiation of BER can be detrimental. Here we illustrate that the alkyladenine DNA glycosylase (AAG mediates alkylation-induced tissue damage and whole-animal lethality following exposure to alkylating agents. Aag-dependent tissue damage, as observed in cerebellar granule cells, splenocytes, thymocytes, bone marrow cells, pancreatic β-cells, and retinal photoreceptor cells, was detected in wild-type mice, exacerbated in Aag transgenic mice, and completely suppressed in Aag⁻/⁻ mice. Additional genetic experiments dissected the effects of modulating both BER and Parp1 on alkylation sensitivity in mice and determined that Aag acts upstream of Parp1 in alkylation-induced tissue damage; in fact, cytotoxicity in WT and Aag transgenic mice was abrogated in the absence of Parp1. These results provide in vivo evidence that Aag-initiated BER may play a critical role in determining the side-effects of alkylating agent chemotherapies and that Parp1 plays a crucial role in Aag-mediated tissue damage.

  18. RECOVERY OF amiRNA3-PARP1 TRANSGENIC MAIZE PLANTS ...

    African Journals Online (AJOL)

    ACSS

    Positive plant selectable marker genes are commonly used in plant transformation because they not only enhance the frequency of generation transgenic tissues but are considered biosafe, unlike antibiotic or herbicide resistance genes. In this study, the binary vector pNOV2819-ubiamiRNA3PARP1, harbouring the ...

  19. Effects of niacin restriction on sirtuin and PARP responses to photodamage in human skin.

    Directory of Open Access Journals (Sweden)

    Claudia A Benavente

    Full Text Available Sirtuins (SIRTs and poly(ADP-ribose polymerases (PARPs, NAD(+-dependent enzymes, link cellular energy status with responses to environmental stresses. Skin is frequently exposed to the DNA damaging effects of UV irradiation, a known etiology in skin cancer. Thus, understanding the defense mechanisms in response to UV, including the role of SIRTs and PARPs, may be important in developing skin cancer prevention strategies. Here, we report expression of the seven SIRT family members in human skin. SIRTs gene expressions are progressively upregulated in A431 epidermoid carcinoma cells (SIRTs1 and 3, actinic keratoses (SIRTs 2, 3, 5, 6, and 7 and squamous cell carcinoma (SIRTs 1-7. Photodamage induces dynamic changes in SIRT expression with upregulation of both SIRT1 and SIRT4 mRNAs. Specific losses of SIRT proteins occur early after photodamage followed by accumulation later, especially for SIRT4. Niacin restriction, which decreases NAD(+, the sirtuin substrate, results in an increase in acetylated proteins, upregulation of SIRTs 2 and 4, increased inherent DNA damage, alterations in SIRT responses to photodamage, abrogation of PARP activation following photodamage, and increased sensitivity to photodamage that is completely reversed by repleting niacin. These data support the hypothesis that SIRTs and PARPs play important roles in resistance to photodamage and identify specific SIRTs that respond to photodamage and may be targets for skin cancer prevention.

  20. PARP-1 and YY1 are important novel regulators of CXCL12 gene transcription in rat pancreatic beta cells.

    Directory of Open Access Journals (Sweden)

    Jelena Marković

    Full Text Available Despite significant progress, the molecular mechanisms responsible for pancreatic beta cell depletion and development of diabetes remain poorly defined. At present, there is no preventive measure against diabetes. The positive impact of CXCL12 expression on the pancreatic beta cell prosurvival phenotype initiated this study. Our aim was to provide novel insight into the regulation of rat CXCL12 gene (Cxcl12 transcription. The roles of poly(ADP-ribose polymerase-1 (PARP-1 and transcription factor Yin Yang 1 (YY1 in Cxcl12 transcription were studied by examining their in vitro and in vivo binding affinities for the Cxcl12 promoter in a pancreatic beta cell line by the electrophoretic mobility shift assay and chromatin immunoprecipitation. The regulatory activities of PARP-1 and YY1 were assessed in transfection experiments using a reporter vector with a Cxcl12 promoter sequence driving luciferase gene expression. Experimental evidence for PARP-1 and YY1 revealed their trans-acting potential, wherein PARP-1 displayed an inhibitory, and YY1 a strong activating effect on Cxcl12 transcription. Streptozotocin (STZ-induced general toxicity in pancreatic beta cells was followed by changes in Cxcl12 promoter regulation. PARP-1 binding to the Cxcl12 promoter during basal and in STZ-compromised conditions led us to conclude that PARP-1 regulates constitutive Cxcl12 expression. During the early stage of oxidative stress, YY1 exhibited less affinity toward the Cxcl12 promoter while PARP-1 displayed strong binding. These interactions were accompanied by Cxcl12 downregulation. In the later stages of oxidative stress and intensive pancreatic beta cell injury, YY1 was highly expressed and firmly bound to Cxcl12 promoter in contrast to PARP-1. These interactions resulted in higher Cxcl12 expression. The observed ability of PARP-1 to downregulate, and of YY1 to upregulate Cxcl12 promoter activity anticipates corresponding effects in the natural context where the

  1. Activity-based assay for human mono-ADP-ribosyltransferases ARTD7/PARP15 and ARTD10/PARP10 aimed at screening and profiling inhibitors.

    Science.gov (United States)

    Venkannagari, Harikanth; Fallarero, Adyary; Feijs, Karla L H; Lüscher, Bernhard; Lehtiö, Lari

    2013-05-13

    Poly(ADP-ribose) polymerases (PARPs) or diphtheria toxin like ADP-ribosyl transferases (ARTDs) are enzymes that catalyze the covalent modification of proteins by attachment of ADP-ribose units to the target amino acid residues or to the growing chain of ADP-ribose. A subclass of the ARTD superfamily consists of mono-ADP-ribosyl transferases that are thought to modify themselves and other substrate proteins by covalently adding only a single ADP-ribose moiety to the target. Many of the ARTD enzymes are either established or potential drug targets and a functional activity assay for them will be a valuable tool to identify selective inhibitors for each enzyme. Existing assays are not directly applicable for screening of inhibitors due to the different nature of the reaction and different target molecules. We modified and applied a fluorescence-based assay previously described for PARP1/ARTD1 and tankyrase/ARTD5 for screening of PARP10/ARTD10 and PARP15/ARTD7 inhibitors. The assay measures the amount of NAD(+) present after chemically converting it to a fluorescent analog. We demonstrate that by using an excess of a recombinant acceptor protein the performance of the activity-based assay is excellent for screening of compound libraries. The assay is homogenous and cost effective, making it possible to test relatively large compound libraries. This method can be used to screen inhibitors of mono-ARTDs and profile inhibitors of the enzyme class. The assay was optimized for ARTD10 and ARTD7, but it can be directly applied to other mono-ARTDs of the ARTD superfamily. Profiling of known ARTD inhibitors against ARTD10 and ARTD7 in a validatory screening identified the best inhibitors with submicromolar potencies. Only few of the tested ARTD inhibitors were potent, implicating that there is a need to screen new compound scaffolds. This is needed to create small molecules that could serve as biological probes and potential starting points for drug discovery projects against

  2. Counteracting venous stasis during acute lower leg immobilization.

    NARCIS (Netherlands)

    Poelkens, F.; Thijssen, D.H.J.; Kersten, B.T.P.; Scheurwater, H.; Laarhoven, E.W. van; Hopman, M.T.E.

    2006-01-01

    AIM: During lower limb immobilization, patients are at risk to develop deep venous thrombosis. Recently, a water-pad was developed that should counteract venous stasis. The water-pad, located under the plaster, mobilizes water from the foot to the calf during weight bearing and, thereby, imitates

  3. Counteracting Age Stereotypes: A Self-Awareness Manipulation

    Science.gov (United States)

    Chen, Yiwei; Pethtel, Olivia; Ma, Xiaodong

    2010-01-01

    The major goals of the present study were to (a) examine age differences in susceptibility to age stereotypes and (b) test a self-awareness manipulation in counteracting age stereotypes. Young and older adults read two sets of descriptors that only differed in the to-be-ignored age-related information. In the high self-awareness condition,…

  4. Ubiquitin-specific Protease 11 (USP11) Deubiquitinates Hybrid Small Ubiquitin-like Modifier (SUMO)-Ubiquitin Chains to Counteract RING Finger Protein 4 (RNF4)

    DEFF Research Database (Denmark)

    Hendriks, Ivo A; Schimmel, Joost; Eifler, Karolin

    2015-01-01

    of RNF4 as a counterbalancing factor. In response to DNA damage induced by methyl methanesulfonate, USP11 could counteract RNF4 to inhibit the dissolution of nuclear bodies. Thus, we provide novel insight into cross-talk between ubiquitin and SUMO and uncover USP11 and RNF4 as a balanced SUMO...

  5. The safety of antiangiogenic agents and PARP inhibitors in platinum-sensitive recurrent ovarian cancer.

    Science.gov (United States)

    Lorusso, Domenica; Fontanella, Caterina; Maltese, Giuseppa; Lepori, Stefano; Tripodi, Elisa; Bogani, Giorgio; Raspagliesi, Francesco

    2017-06-01

    Recurrence is a common event in endothelial ovarian cancer (EOC) patients, and the choice of the most appropriate treatment is driven by the platinum-free interval, molecular characteristics of the disease such as BRCA mutational status, previous treatments and toxicity. Areas covered: This review focuses on the main hematologic and non-hematologic toxicities correlated with the use of licensed antiangiogenic agents and PARP inhibitors in recurrent platinum-sensitive EOC, providing recommendations for their management. Expert opinion: The clinical research over the next years will be focused on a more precise characterization of molecular pathways underlying tumorigenesis of the five ovarian tumors, to improve the decision-making process in these rare diseases. For this purpose, new study designs and international collaborations will become mandatory. Immunotherapy, antiangiogenic agents and PARP inhibitors will be combined to build a treatment strategy algorithm which will allow patients to receive all the available treatment option, in the more appropriate sequence.

  6. ATM-Deficient Colorectal Cancer Cells Are Sensitive to the PARP Inhibitor Olaparib.

    Science.gov (United States)

    Wang, Chen; Jette, Nicholas; Moussienko, Daniel; Bebb, D Gwyn; Lees-Miller, Susan P

    2017-04-01

    The ataxia telangiectasia mutated (ATM) protein kinase plays a central role in the cellular response to DNA damage. Loss or inactivation of both copies of the ATM gene (ATM) leads to ataxia telangiectasia, a devastating childhood condition characterized by neurodegeneration, immune deficiencies, and cancer predisposition. ATM is also absent in approximately 40% of mantle cell lymphomas (MCLs), and we previously showed that MCL cell lines with loss of ATM are sensitive to poly-ADP ribose polymerase (PARP) inhibitors. Next-generation sequencing of patient tumors has revealed that ATM is altered in many human cancers including colorectal, lung, prostate, and breast. Here, we show that the colorectal cancer cell line SK-CO-1 lacks detectable ATM protein expression and is sensitive to the PARP inhibitor olaparib. Similarly, HCT116 colorectal cancer cells with shRNA depletion of ATM are sensitive to olaparib, and depletion of p53 enhances this sensitivity. Moreover, HCT116 cells are sensitive to olaparib in combination with the ATM inhibitor KU55933, and sensitivity is enhanced by deletion of p53. Together our studies suggest that PARP inhibitors may have potential for treating colorectal cancer with ATM dysfunction and/or colorectal cancer with mutation of p53 when combined with an ATM kinase inhibitor. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Gemcitabine-induced CXCL8 expression counteracts its actions by inducing tumor neovascularization

    International Nuclear Information System (INIS)

    Song, Yao; Baba, Tomohisa; Li, Ying-Yi; Furukawa, Kaoru; Tanabe, Yamato; Matsugo, Seiichi; Sasaki, Soichiro; Mukaida, Naofumi

    2015-01-01

    Patients with pancreatic ductal adenocarcinoma (PDAC) are frequently complicated with metastatic disease or locally advanced tumors, and consequently need chemotherapy. Gemcitabine is commonly used for PDAC treatment, but with limited efficacy. The capacity of gemcitabine to generate reactive oxygen species (ROS) in human pancreatic cancer cells, prompted us to examine its effects on the expression of pro-inflammatory cytokines and chemokines. We observed that gemcitabine enhanced selectively the expression of CXCL8 in human pancreatic cancer cells through ROS generation and NF-κB activation. In vitro blocking of CXCL8 failed to modulate gemcitabine-mediated inhibition of cell proliferation in human pancreatic cancer cells. Gemcitabine also enhanced CXCL8 expression in pancreatic cancer cells in xenografted tumor tissues. Moreover, anti-CXCL8 antibody treatment in vivo attenuated tumor formation as well as intra-tumoral vascularity in nude mice, which were transplanted with Miapaca-2 cells and treated with gemcitabine. Thus, gemcitabine-induced CXCL8 may counteract the drug through inducing neovascularization. - Highlights: • Gemcitabine induced CXCL8 expression in human pancreatic cancer cells. • CXCL8 expression required ROS generation and NF-κB activation. • CXCL8 did not affect in vitro proliferation of human pancreatic cancer cells. • CXCL8 in vivo counteracted gemcitabine by inducing neovascularization

  8. Gemcitabine-induced CXCL8 expression counteracts its actions by inducing tumor neovascularization

    Energy Technology Data Exchange (ETDEWEB)

    Song, Yao; Baba, Tomohisa [Division of Molecular Bioregulation, Cancer Research Institute, Kanazawa University, Kanazawa, Ishikawa 920-1192 (Japan); Li, Ying-Yi [Cancer Research Institute, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai (China); Furukawa, Kaoru; Tanabe, Yamato [Division of Molecular Bioregulation, Cancer Research Institute, Kanazawa University, Kanazawa, Ishikawa 920-1192 (Japan); School of Natural System Bioengineering Course, College of Science and Engineering, Kanazawa University, Kanazawa, Ishikawa (Japan); Matsugo, Seiichi [School of Natural System Bioengineering Course, College of Science and Engineering, Kanazawa University, Kanazawa, Ishikawa (Japan); Sasaki, Soichiro [Division of Molecular Bioregulation, Cancer Research Institute, Kanazawa University, Kanazawa, Ishikawa 920-1192 (Japan); Mukaida, Naofumi, E-mail: mukaida@staff.kanazawa-u.ac.jp [Division of Molecular Bioregulation, Cancer Research Institute, Kanazawa University, Kanazawa, Ishikawa 920-1192 (Japan)

    2015-03-06

    Patients with pancreatic ductal adenocarcinoma (PDAC) are frequently complicated with metastatic disease or locally advanced tumors, and consequently need chemotherapy. Gemcitabine is commonly used for PDAC treatment, but with limited efficacy. The capacity of gemcitabine to generate reactive oxygen species (ROS) in human pancreatic cancer cells, prompted us to examine its effects on the expression of pro-inflammatory cytokines and chemokines. We observed that gemcitabine enhanced selectively the expression of CXCL8 in human pancreatic cancer cells through ROS generation and NF-κB activation. In vitro blocking of CXCL8 failed to modulate gemcitabine-mediated inhibition of cell proliferation in human pancreatic cancer cells. Gemcitabine also enhanced CXCL8 expression in pancreatic cancer cells in xenografted tumor tissues. Moreover, anti-CXCL8 antibody treatment in vivo attenuated tumor formation as well as intra-tumoral vascularity in nude mice, which were transplanted with Miapaca-2 cells and treated with gemcitabine. Thus, gemcitabine-induced CXCL8 may counteract the drug through inducing neovascularization. - Highlights: • Gemcitabine induced CXCL8 expression in human pancreatic cancer cells. • CXCL8 expression required ROS generation and NF-κB activation. • CXCL8 did not affect in vitro proliferation of human pancreatic cancer cells. • CXCL8 in vivo counteracted gemcitabine by inducing neovascularization.

  9. Feedback-regulated poly(ADP-ribosyl)ation by PARP-1 is required for rapid response to DNA damage in living cells

    Science.gov (United States)

    Mortusewicz, Oliver; Amé, Jean-Christophe; Leonhardt, Heinrich

    2007-01-01

    Genome integrity is constantly threatened by DNA lesions arising from numerous exogenous and endogenous sources. Survival depends on immediate recognition of these lesions and rapid recruitment of repair factors. Using laser microirradiation and live cell microscopy we found that the DNA-damage dependent poly(ADP-ribose) polymerases (PARP) PARP-1 and PARP-2 are recruited to DNA damage sites, however, with different kinetics and roles. With specific PARP inhibitors and mutations, we could show that the initial recruitment of PARP-1 is mediated by the DNA-binding domain. PARP-1 activation and localized poly(ADP-ribose) synthesis then generates binding sites for a second wave of PARP-1 recruitment and for the rapid accumulation of the loading platform XRCC1 at repair sites. Further PARP-1 poly(ADP-ribosyl)ation eventually initiates the release of PARP-1. We conclude that feedback regulated recruitment of PARP-1 and concomitant local poly(ADP-ribosyl)ation at DNA lesions amplifies a signal for rapid recruitment of repair factors enabling efficient restoration of genome integrity. PMID:17982172

  10. Importin alpha binding and nuclear localization of PARP-2 is dependent on lysine 36, which is located within a predicted classical NLS

    Directory of Open Access Journals (Sweden)

    Valovka Taras

    2008-07-01

    Full Text Available Abstract Background The enzymes responsible for the synthesis of poly-ADP-ribose are named poly-ADP-ribose polymerases (PARP. PARP-2 is a nuclear protein, which regulates a variety of cellular functions that are mainly controlled by protein-protein interactions. A previously described non-conventional bipartite nuclear localization sequence (NLS lies in the amino-terminal DNA binding domain of PARP-2 between amino acids 1–69; however, this targeting sequence has not been experimentally examined or validated. Results Using a site-directed mutagenesis approach, we found that lysines 19 and 20, located within a previously described bipartite NLS, are not required for nuclear localization of PARP-2. In contrast, lysine 36, which is located within a predicted classical monopartite NLS, was required for PARP-2 nuclear localization. While wild type PARP-2 interacted with importin α3 and to a very weak extent with importin α1 and importin α5, the mutant PARP-2 (K36R did not interact with importin α3, providing a molecular explanation why PARP-2 (K36R is not targeted to the nucleus. Conclusion Our results provide strong evidence that lysine 36 of PARP-2 is a critical residue for proper nuclear targeting of PARP-2 and consequently for the execution of its biological functions.

  11. Functional characterisation of an Arabidopsis gene strongly induced by ionising radiation: the gene coding the poly(ADP-ribose)polymerase-1 (AthPARP-1)

    International Nuclear Information System (INIS)

    Doucet-Chabeaud, G.

    2000-01-01

    Arabidopsis thaliana, the model-system in plant genetics, has been used to study the responses to DNA damage, experimentally introduced by γ-irradiation. We have characterised a radiation-induced gene coding a 111 kDa protein, AthPARP-1, homologous to the human poly(ADP-ribose)polymerase-1 (hPARP-1). As hPARP-1 is composed by three functional domain with characteristic motifs, AthPARP-1 binds to DNA bearing single-strand breaks and shows DNA damage-dependent poly(ADP-ribosyl)ation. The preferential expression of AthPARP-1 in mitotically active tissues is in agreement with a potential role in the maintenance of genome integrity during DNA replication, as proposed for its human counterpart. Transcriptional gene activation by ionising radiation of AthPARP-1 and AthPARP-2 genes is to date plant specific activation. Our expression analyses after exposure to various stress indicate that 1) AthPARP-1 and AthPARP-2 play an important role in the response to DNA lesions, particularly they are activated by genotoxic agents implicating the BER DNA repair pathway 2) AthPARP-2 gene seems to play an additional role in the signal transduction induced by oxidative stress 3) the observed expression profile of AthPARP-1 is in favour of the regulation of AthPARP-1 gene expression at the level of transcription and translation. This mode of regulation of AthPARP-1 protein biosynthesis, clearly distinct from that observed in animals, needs the implication of a so far unidentified transcription factor that is activated by the presence of DNA lesions. The major outcome of this work resides in the isolation and characterisation of such new transcription factor, which will provide new insight on the regulation of plant gene expression by genotoxic stress. (author) [fr

  12. Counteracting the Influence of Peer Smoking on YouTube

    OpenAIRE

    Romer, Daniel; Jamieson, Patrick E.; Jamieson, Kathleen Hall; Jones, Christopher; Sherr, Susan

    2017-01-01

    YouTube, a popular online site for user-generated content, is emerging as a powerful source of peer modeling of smoking. Previous research suggests that in counteracting such influence, health messages may inadvertently increase the perceived prevalence of drug use (a descriptive norm) without reducing its acceptability (injunctive norm). This research tested the ability of health messages to reduce the social acceptability of peer smoking on YouTube despite enhancing its perceived prevalence...

  13. Sustainability and Counteracting Factors to Profit Rate Decline

    DEFF Research Database (Denmark)

    Ougaard, Morten

    2014-01-01

    This paper discusses sustainability implications of barriers to growth as specified in the theory of the long-term falling rate of profit but focusing on the counteracting factors (CFs) specified by Marx. These depend much on political processes and are important in state theory for understanding...... policies of national and international institutions. Fourteen partly overlapping factors are identified and grouped in five categories: increased pressure on labor, geographical expansion, resource efficiency, technological progress, and destruction or devaluation of capital. It is suggested...

  14. Propionyl-L-Carnitine Enhances Wound Healing and Counteracts Microvascular Endothelial Cell Dysfunction.

    Directory of Open Access Journals (Sweden)

    Maria Giovanna Scioli

    Full Text Available Impaired wound healing represents a high cost for health care systems. Endothelial dysfunction characterizes dermal microangiopathy and contributes to delayed wound healing and chronic ulcers. Endothelial dysfunction impairs cutaneous microvascular blood flow by inducing an imbalance between vasorelaxation and vasoconstriction as a consequence of reduced nitric oxide (NO production and the increase of oxidative stress and inflammation. Propionyl-L-carnitine (PLC is a natural derivative of carnitine that has been reported to ameliorate post-ischemic blood flow recovery.We investigated the effects of PLC in rat skin flap and cutaneous wound healing. A daily oral PLC treatment improved skin flap viability and associated with reactive oxygen species (ROS reduction, inducible nitric oxide synthase (iNOS and NO up-regulation, accelerated wound healing and increased capillary density, likely favoring dermal angiogenesis by up-regulation for iNOS, vascular endothelial growth factor (VEGF, placental growth factor (PlGF and reduction of NADPH-oxidase 4 (Nox4 expression. In serum-deprived human dermal microvascular endothelial cell cultures, PLC ameliorated endothelial dysfunction by increasing iNOS, PlGF, VEGF receptors 1 and 2 expression and NO level. In addition, PLC counteracted serum deprivation-induced impairment of mitochondrial β-oxidation, Nox4 and cellular adhesion molecule (CAM expression, ROS generation and leukocyte adhesion. Moreover, dermal microvascular endothelial cell dysfunction was prevented by Nox4 inhibition. Interestingly, inhibition of β-oxidation counteracted the beneficial effects of PLC on oxidative stress and endothelial dysfunction.PLC treatment improved rat skin flap viability, accelerated wound healing and dermal angiogenesis. The beneficial effects of PLC likely derived from improvement of mitochondrial β-oxidation and reduction of Nox4-mediated oxidative stress and endothelial dysfunction. Antioxidant therapy and

  15. Effects of PARP-1 inhibitors AG-014699 and AZD2281 on proliferation and apoptosis of human hepatoma cell line HepG2

    Directory of Open Access Journals (Sweden)

    DU Senrong

    2015-06-01

    Full Text Available ObjectiveTo observe the inhibitory and pro-apoptotic effects of two poly(ADP-ribose polymerase (PARP-1 inhibitors, AG-014699 and AZD2281, on human hepatoma HepG2 cells and preliminarily explore the mechanism by which AG-014699 induces HepG2 cell apoptosis, and to provide a new therapeutic target for hepatoma. MethodsThe effects of different concentrations of AG-014699 and AZD2281 on HepG2 cell proliferation were determined by MTT assay. The cell apoptosis rate was measured by flow cytometry. The expression levels of caspase-3 and caspase-8 were measured by Western Blot. Inter-group comparison was made by t test. ResultsBoth AG-014699 and AZD2281 suppressed HepG2 cell proliferation in a time- and dose-dependent manner. However, the sensitivity of HepG2 cells to the two PARP-1 inhibitors was different. The half-maximal inhibitory concentrations of AG-014699 and AZD2281 at 48 h determined by MTT assay were about 20 μmol/L and 400 μmol/L, respectively. Flow cytometry and Western blot were not used to evaluate the apoptosis of HepG2 cells exposed to AZD2281 to which these cells were not sensitive. HepG2 cell apoptosis could be induced by 10, 30, and 50 μmol/L AG-014699, and the highest apoptosis rate at 48 h was significantly higher than that of the control group (3100%±2.13% vs 09%±0013%, P<0.01. Compared with those in the control group, the protein levels of caspase-3 and caspase-8 in HepG2 cells after 48-h exposure to 30, and 50 μmol/L AG-014699 increased. ConclusionThe two PARP-1 inhibitors AG-014699 and AZD2281 can inhibit the proliferation of HepG2 cells, which showed different sensitivities to the two inhibitors. AG-014699 can induce HepG2 cell apoptosis by up-regulating the protein expression of caspase-3 and caspase-8.

  16. Poly(ADP-ribose polymerase 1 (PARP1 overexpression in human breast cancer stem cells and resistance to olaparib.

    Directory of Open Access Journals (Sweden)

    Marine Gilabert

    Full Text Available BACKGROUND: Breast cancer stem cells (BCSCs have been recognized as playing a major role in various aspects of breast cancer biology. To identify specific biomarkers of BCSCs, we have performed comparative proteomics of BCSC-enriched and mature cancer cell populations from the human breast cancer cell line (BCL, BrCA-MZ-01. METHODS: ALDEFLUOR assay was used to sort BCSC-enriched (ALDH+ and mature cancer (ALDH- cell populations. Total proteins were extracted from both fractions and subjected to 2-Dimensional Difference In-Gel Electrophoresis (2-D DIGE. Differentially-expressed spots were excised and proteins were gel-extracted, digested and identified using MALDI-TOF MS. RESULTS: 2-D DIGE identified poly(ADP-ribose polymerase 1 (PARP1 as overexpressed in ALDH+ cells from BrCA-MZ-01. This observation was confirmed by western blot and extended to four additional human BCLs. ALDH+ cells from BRCA1-mutated HCC1937, which had the highest level of PARP1 overexpression, displayed resistance to olaparib, a specific PARP1 inhibitor. CONCLUSION: An unbiased proteomic approach identified PARP1 as upregulated in ALDH+, BCSC-enriched cells from various human BCLs, which may contribute to clinical resistance to PARP inhibitors.

  17. Concurrent targeting of nitrosative stress-PARP pathway corrects functional, behavioral and biochemical deficits in experimental diabetic neuropathy

    Energy Technology Data Exchange (ETDEWEB)

    Negi, Geeta; Kumar, Ashutosh [Molecular Neuropharmacology Laboratory, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Sector-67, S.A.S. Nagar, Punjab 160062 (India); Sharma, Shyam S., E-mail: sssharma@niper.ac.in [Molecular Neuropharmacology Laboratory, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Sector-67, S.A.S. Nagar, Punjab 160062 (India)

    2010-01-01

    Peroxynitrite mediated nitrosative stress, an indisputable initiator of DNA damage and overactivation of poly(ADP-ribose) polymerase (PARP), a nuclear enzyme activated after sensing DNA damage, are two crucial pathogenetic mechanisms in diabetic neuropathy. The intent of the present study was to investigate the effect of combination of a peroxynitrite decomposition catalyst (PDC), FeTMPyP and a PARP inhibitor, 4-ANI against diabetic peripheral neuropathy. The end points of evaluation of the study included motor nerve conduction velocity (MNCV) and nerve blood flow (NBF) for evaluating nerve functions; thermal hyperalgesia and mechanical allodynia for assessing nociceptive alterations, malondialdehyde and peroxynitrite levels to detect oxidative stress-nitrosative stress; NAD concentration in sciatic nerve to assess overactivation of PARP. Additionally immunohistochemical studies for nitrotyrosine and Poly(ADP-ribose) (PAR) was also performed. Treatment with the combination of FeTMPyP and 4-ANI led to significant improvement in nerve functions and pain parameters and also attenuated the oxidative-nitrosative stress markers. Further, the combination also reduced the overactivation of PARP as evident from increased NAD levels and decreased PAR immunopositivity in sciatic nerve microsections. Thus, it can be concluded that treatment with the combination of a PDC and PARP inhibitor attenuates alteration in peripheral nerves in diabetic neuropathy (DN).

  18. Testing can counteract proactive interference by integrating competing information

    Science.gov (United States)

    Wahlheim, Christopher N.

    2015-01-01

    Testing initially learned information before presenting new information has been shown to counteract the deleterious effects of proactive interference by segregating competing sources of information. The present experiments were conducted to demonstrate that testing can also have its effects in part by integrating competing information. Variations of classic A–B, A–D paired-associate learning paradigms were employed that included two lists of word pairs and a cued-recall test. Repeated pairs appeared in both lists (A–B, A–B), control pairs appeared in List 2 only (A–B, C–D), and changed pairs appeared with the same cue in both lists but with different responses (A–B, A–D). The critical manipulation was whether pairs were tested or restudied in an interpolated phase that occurred between Lists 1 and 2. On a final cued-recall test, participants recalled List 2 responses and then indicated when they recollected that responses had earlier changed between lists. The change recollection measure indexed the extent to which competing responses were integrated during List 2. Change was recollected more often for tested than for restudied pairs. Proactive facilitation was obtained in cued recall when change was recollected, whereas proactive interference was obtained when change was not recollected. These results provide evidence that testing counteracted proactive interference in part by making List 1 responses more accessible during List 2, thus promoting integration and increasing later recollection of change. These results have theoretical implications because they show that testing can counteract proactive interference by integrating or segregating competing information. PMID:25120241

  19. Testing can counteract proactive interference by integrating competing information.

    Science.gov (United States)

    Wahlheim, Christopher N

    2015-01-01

    Testing initially learned information before presenting new information has been shown to counteract the deleterious effects of proactive interference by segregating competing sources of information. The present experiments were conducted to demonstrate that testing can also have its effects in part by integrating competing information. Variations of classic A-B, A-D paired-associate learning paradigms were employed that included two lists of word pairs and a cued-recall test. Repeated pairs appeared in both lists (A-B, A-B), control pairs appeared in List 2 only (A-B, C-D), and changed pairs appeared with the same cue in both lists but with different responses (A-B, A-D). The critical manipulation was whether pairs were tested or restudied in an interpolated phase that occurred between Lists 1 and 2. On a final cued-recall test, participants recalled List 2 responses and then indicated when they recollected that responses had earlier changed between lists. The change recollection measure indexed the extent to which competing responses were integrated during List 2. Change was recollected more often for tested than for restudied pairs. Proactive facilitation was obtained in cued recall when change was recollected, whereas proactive interference was obtained when change was not recollected. These results provide evidence that testing counteracted proactive interference in part by making List 1 responses more accessible during List 2, thus promoting integration and increasing later recollection of change. These results have theoretical implications because they show that testing can counteract proactive interference by integrating or segregating competing information.

  20. Counteracting loneliness: on the restorative function of nostalgia.

    Science.gov (United States)

    Zhou, Xinyue; Sedikides, Constantine; Wildschut, Tim; Gao, Ding-Guo

    2008-10-01

    Four studies tested whether nostalgia can counteract reductions in perceived social support caused by loneliness. Loneliness reduced perceptions of social support but increased nostalgia. Nostalgia, in turn, increased perceptions of social support. Thus, loneliness affected perceived social support in two distinct ways. Whereas the direct effect of loneliness was to reduce perceived social support, the indirect effect of loneliness was to increase perceived social support via nostalgia. This restorative function of nostalgia was particularly apparent among resilient persons. Nostalgia is a psychological resource that protects and fosters mental health.

  1. COUNTERACTING AGE STEREOTYPES: A SELF-AWARENESS MANIPULATION

    OpenAIRE

    Chen, Yiwei; Pethtel, Olivia; Ma, Xiaodong

    2010-01-01

    The major goals of the present study were to (a) examine age differences in susceptibility to age stereotypes and (b) test a self-awareness manipulation in counteracting age stereotypes. Young and older adults read two sets of descriptors that only differed in the to-be-ignored age-related information. In the high self-awareness condition, participants saw themselves via a computer video camera. In the low self-awareness condition, they saw prerecorded images of a stranger. Overall, older adu...

  2. Counteracting age-related loss of skeletal muscle mass

    DEFF Research Database (Denmark)

    Bechshøft, Rasmus; Reitelseder, Søren; Højfeldt, Grith

    2016-01-01

    Background Aging is associated with decreased muscle mass and functional capacity, which in turn decrease quality of life. The number of citizens over the age of 65 years in the Western world will increase by 50 % over the next four decades, and this demographic shift brings forth new challenges...... at both societal and individual levels. Only a few longitudinal studies have been reported, but whey protein supplementation seems to improve muscle mass and function, and its combination with heavy strength training appears even more effective. However, heavy resistance training may reduce adherence...... Intervention Study will generate scientific evidence and recommendations to counteract age-related loss of skeletal muscle mass in elderly individuals....

  3. PARPs database: A LIMS systems for protein-protein interaction data mining or laboratory information management system

    Directory of Open Access Journals (Sweden)

    Picard-Cloutier Aude

    2007-12-01

    Full Text Available Abstract Background In the "post-genome" era, mass spectrometry (MS has become an important method for the analysis of proteins and the rapid advancement of this technique, in combination with other proteomics methods, results in an increasing amount of proteome data. This data must be archived and analysed using specialized bioinformatics tools. Description We herein describe "PARPs database," a data analysis and management pipeline for liquid chromatography tandem mass spectrometry (LC-MS/MS proteomics. PARPs database is a web-based tool whose features include experiment annotation, protein database searching, protein sequence management, as well as data-mining of the peptides and proteins identified. Conclusion Using this pipeline, we have successfully identified several interactions of biological significance between PARP-1 and other proteins, namely RFC-1, 2, 3, 4 and 5.

  4. Topical legal aspects of corruption counteraction in public procurement

    Directory of Open Access Journals (Sweden)

    Aleksandr Igorevich Zemlin

    2015-03-01

    Full Text Available Objective to analyze the current developments in the Russian legislation on corruption counteraction and the legislation on public procurement system on this basis to study legal conflicts and gaps and to develop proposals under the provisions of the National AntiCorruption Plan for 2014ndash2015. Methods historical formallegal logical and systemicfunctional structural and contextual approach to the study of law and theoretical propositions concerning the definition nature and characteristics of legal relations arising in the process of and relating to the corruption counteraction in the public procurement system. Results аn aggregate of theoretical conclusions and proposals aimed at perfection of anticorruption legislation and legislation on the contractual public procurement system is presented. Scientific novelty the results of the author39s interpretation of changes in the Russian anticorruption legislation and legislation on the contractual public procurement system existing legal conflicts and gaps. Practical significance developing proposals for improving the standards of anticorruption legislation and legislation on public procurement system under the provisions of the National AntiCorruption Plan for 2014ndash2015. nbsp

  5. SU-E-T-245: MR Guided Focused Ultrasound Increased PARP Related Apoptosis On Prostate Cancer in Vivo

    International Nuclear Information System (INIS)

    Chen, L; Chen, X; Cvetkovic, D; Gupta, R; Yang, D; Ma, C

    2014-01-01

    Purpose: Our previous study demonstrated that significant tumor growth delay was observed in the mice treated with pulsed high intensity focused ultrasound (pHIFU). The purpose of this study is to understand the cell killing mechanisms of pHIFU. Methods: Prostate cancer cells (LNCaP), were grown orthotopically in 17 nude mice. Tumor-bearing mice were treated using pHIFU with an acoustic power of 25W, pulse width 100msec and 300 pulses in one sonication under MR guidance. Mutiple sonications were used to cover the whole tumor volume. Temperature (less than 40 degree centigrade in the focal spot) was monitored using MR thermometry. Animals were euthanized at pre-determined time points (n=2) after treatment: 0 hours; 6 hrs; 24 hrs; 48 hrs; 4 days and 7 days. Two tumorbearing mice were used as control. Three tumor-bearing mice were treated with radiation (RT, 2 Gy) using 6 MV photon beams. RT treated mice were euthanized at 0 hr, 6 hrs and 24 hrs. The tumors were processed for immunohistochemical (IHC) staining for PARP (a surrogate of apoptosis). A multispectral imaging analysis system was used to quantify the expression of PARP staining. Cell apoptosis was calculated based on the PARP expression level, which is the intensity of the DAB reaction. Results: Our data showed that PARP related apoptosis peaked at 48 hrs and 7 days in pHIFU treated mice, which is comparable to that for the RT group at 24 hrs. The preliminary results from this study were consistent with our previous study on tumor growth delay using pHIFU. Conclusion: Our results demonstrated that non-thermal pHIFU increased apoptotic tumor cell death through the PARP related pathway. MR guided pHIFU may have a great potential as a safe, noninvasive treatment modality for cancer therapy. This treatment modality might be able to synergize with PARP inhibitors to achieve better result

  6. Melatonin regulates PARP1 to control the senescence-associated secretory phenotype (SASP) in human fetal lung fibroblast cells.

    Science.gov (United States)

    Yu, Songtao; Wang, Xiaojiao; Geng, Peiliang; Tang, Xudong; Xiang, Lisha; Lu, Xin; Li, Jianjun; Ruan, Zhihua; Chen, Jianfang; Xie, Ganfeng; Wang, Zhe; Ou, Juanjuan; Peng, Yuan; Luo, Xi; Zhang, Xuan; Dong, Yan; Pang, Xueli; Miao, Hongming; Chen, Hongshan; Liang, Houjie

    2017-08-01

    Cellular senescence is an important tumor-suppressive mechanism. However, acquisition of a senescence-associated secretory phenotype (SASP) in senescent cells has deleterious effects on the tissue microenvironment and, paradoxically, promotes tumor progression. In a drug screen, we identified melatonin as a novel SASP suppressor in human cells. Strikingly, melatonin blunts global SASP gene expression upon oncogene-induced senescence (OIS). Moreover, poly(ADP-ribose) polymerase-1 (PARP-1), a sensor of DNA damage, was identified as a new melatonin-dependent regulator of SASP gene induction upon OIS. Here, we report two different but potentially coherent epigenetic strategies for melatonin regulation of SASP. The interaction between the telomeric repeat-containing RNA (TERRA) and PARP-1 stimulates the SASP, which was attenuated by 67.9% (illustrated by the case of IL8) by treatment with melatonin. Through binding to macroH2A1.1, PARP-1 recruits CREB-binding protein (CBP) to mediate acetylation of H2BK120, which positively regulates the expression of target SASP genes, and this process is interrupted by melatonin. Consequently, the findings provide novel insight into melatonin's epigenetic role via modulating PARP-1 in suppression of SASP gene expression in OIS-induced senescent cells. Our studies identify melatonin as a novel anti-SASP molecule, define PARP-1 as a new target by which melatonin regulates SASP, and establish a new epigenetic paradigm for a pharmacological mechanism by which melatonin interrupts PARP-1 interaction with the telomeric long noncoding RNA(lncRNA) or chromatin. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Vitamin D Counteracts Mycobacterium tuberculosis-Induced Cathelicidin Downregulation in Dendritic Cells and Allows Th1 Differentiation and IFNγ Secretion

    Directory of Open Access Journals (Sweden)

    Anna K. O. Rode

    2017-05-01

    Full Text Available Tuberculosis (TB presents a serious health problem with approximately one-third of the world’s population infected with Mycobacterium tuberculosis in a latent state. Experience from the pre-antibiotic era and more recent clinical studies have established a beneficial role of sunlight and vitamin D in patients with TB. At the same time, experimental data have shown that Th1 cells through production of IFNγ are crucial for cathelicidin release by macrophages, bacterial killing, and containment of M. tuberculosis in granulomas. Paradoxically, vitamin D has repeatedly been ascribed an immune-suppressive function inhibiting Th1 differentiation and production of IFNγ in T cells. The aim of this study was to investigate this apparent paradox. We studied naïve human CD4+ T cells activated either with CD3 and CD28 antibodies or with allogeneic dendritic cells (DC stimulated with heat-killed M. tuberculosis (HKMT or purified toll-like receptor (TLR ligands. We show that vitamin D does not block differentiation of human CD4+ T cells to Th1 cells and that interleukin (IL-12 partially counteracts vitamin D-mediated inhibition of IFNγ production promoting production of equal amounts of IFNγ in Th1 cells in the presence of vitamin D as in T cells activated in the absence of vitamin D and IL-12. Furthermore, we show that HKMT and TLR2 ligands strongly downregulate cathelicidin expression in DC and that vitamin D counteracts this by upregulating cathelicidin expression. In conclusion, we demonstrate that vitamin D counteracts M. tuberculosis-induced cathelicidin downregulation and allows Th1 differentiation and IFNγ secretion.

  8. Vitamin D Counteracts Mycobacterium tuberculosis-Induced Cathelicidin Downregulation in Dendritic Cells and Allows Th1 Differentiation and IFNγ Secretion.

    Science.gov (United States)

    Rode, Anna K O; Kongsbak, Martin; Hansen, Marie M; Lopez, Daniel Villalba; Levring, Trine B; Woetmann, Anders; Ødum, Niels; Bonefeld, Charlotte M; Geisler, Carsten

    2017-01-01

    Tuberculosis (TB) presents a serious health problem with approximately one-third of the world's population infected with Mycobacterium tuberculosis in a latent state. Experience from the pre-antibiotic era and more recent clinical studies have established a beneficial role of sunlight and vitamin D in patients with TB. At the same time, experimental data have shown that Th1 cells through production of IFNγ are crucial for cathelicidin release by macrophages, bacterial killing, and containment of M. tuberculosis in granulomas. Paradoxically, vitamin D has repeatedly been ascribed an immune-suppressive function inhibiting Th1 differentiation and production of IFNγ in T cells. The aim of this study was to investigate this apparent paradox. We studied naïve human CD4 + T cells activated either with CD3 and CD28 antibodies or with allogeneic dendritic cells (DC) stimulated with heat-killed M. tuberculosis (HKMT) or purified toll-like receptor (TLR) ligands. We show that vitamin D does not block differentiation of human CD4 + T cells to Th1 cells and that interleukin (IL)-12 partially counteracts vitamin D-mediated inhibition of IFNγ production promoting production of equal amounts of IFNγ in Th1 cells in the presence of vitamin D as in T cells activated in the absence of vitamin D and IL-12. Furthermore, we show that HKMT and TLR2 ligands strongly downregulate cathelicidin expression in DC and that vitamin D counteracts this by upregulating cathelicidin expression. In conclusion, we demonstrate that vitamin D counteracts M. tuberculosis -induced cathelicidin downregulation and allows Th1 differentiation and IFNγ secretion.

  9. Recurrent hypoinsulinemic hyperglycemia in neonatal rats increases PARP-1 and NF-κB expression and leads to microglial activation in the cerebral cortex.

    Science.gov (United States)

    Gisslen, Tate; Ennis, Kathleen; Bhandari, Vineet; Rao, Raghavendra

    2015-11-01

    Hyperglycemia is a common metabolic problem in extremely low-birth-weight preterm infants. Neonatal hyperglycemia is associated with increased mortality and brain injury. Glucose-mediated oxidative injury may be responsible. Poly(ADP-ribose) polymerase-1 (PARP-1) is a nuclear enzyme involved in DNA repair and cell survival. However, PARP-1 overactivation leads to cell death. NF-κB is coactivated with PARP-1 and regulates microglial activation. The effects of recurrent hyperglycemia on PARP-1/NF-κB expression and microglial activation are not well understood. Rat pups were subjected to recurrent hypoinsulinemic hyperglycemia of 2 h duration twice daily from postnatal (P) day 3-P12 and killed on P13. mRNA and protein expression of PARP-1/NF-κB and their downstream effectors were determined in the cerebral cortex. Microgliosis was determined using CD11 immunohistochemistry. Recurrent hyperglycemia increased PARP-1 expression confined to the nucleus and without causing PARP-1 overactivation and cell death. NF-κB mRNA expression was increased, while IκB mRNA expression was decreased. inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), and neuronal nitric oxide synthase (nNOS) mRNA expressions were decreased. Hyperglycemia significantly increased the number of microglia. Recurrent hyperglycemia in neonatal rats is associated with upregulation of PARP-1 and NF-κB expression and subsequent microgliosis but not neuronal cell death in the cerebral cortex.

  10. The nuclear protein Poly(ADP-ribose) polymerase 3 (AtPARP3) is required for seed storability in Arabidopsis thaliana.

    Science.gov (United States)

    Rissel, D; Losch, J; Peiter, E

    2014-11-01

    The deterioration of seeds during prolonged storage results in a reduction of viability and germination rate. DNA damage is one of the major cellular defects associated with seed deterioration. It is provoked by the formation of reactive oxygen species (ROS) even in the quiescent state of the desiccated seed. In contrast to other stages of seed life, DNA repair during storage is hindered through the low seed water content; thereby DNA lesions can accumulate. To allow subsequent seedling development, DNA repair has thus to be initiated immediately upon imbibition. Poly(ADP-ribose) polymerases (PARPs) are important components in the DNA damage response in humans. Arabidopsis thaliana contains three homologues to the human HsPARP1 protein. Of these three, only AtPARP3 was very highly expressed in seeds. Histochemical GUS staining of embryos and endosperm layers revealed strong promoter activity of AtPARP3 during all steps of germination. This coincided with high ROS activity and indicated a role of the nuclear-localised AtPARP3 in DNA repair during germination. Accordingly, stored parp3-1 mutant seeds lacking AtPARP3 expression displayed a delay in germination as compared to Col-0 wild-type seeds. A controlled deterioration test showed that the mutant seeds were hypersensitive to unfavourable storage conditions. The results demonstrate that AtPARP3 is an important component of seed storability and viability. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  11. Counteracting effect of threat on reward enhancements during working memory.

    Science.gov (United States)

    Choi, Jong Moon; Padmala, Srikanth; Pessoa, Luiz

    2015-01-01

    Cognitive performance has been shown to be enhanced when performance-based rewards are at stake. On the other hand, task-irrelevant threat processing has been shown to have detrimental effects during several cognitive tasks. Crucially, the impact of reward and threat on cognition has been studied largely independently of one another. Hence, our understanding of how reward and threat simultaneously contribute to performance is incomplete. To fill in this gap, the present study investigated how reward and threat interact with one another during a cognitive task. We found that threat of shock counteracted the beneficial effect of reward during a working memory task. Furthermore, individual differences in self-reported reward-sensitivity and anxiety were linked to the extent to which reward and threat interacted during behaviour. Together, the current findings contribute to a limited but growing literature unravelling how positive and negative information processing jointly influence cognition.

  12. Acidification counteracts negative effects of warming on diatom silicification

    KAUST Repository

    Coello-Camba, Alexandra

    2016-10-24

    Diatoms are a significant group contributing up to 40 % of annual primary production in the oceans. They have a special siliceous cell wall that, acting as a ballast, plays a key role in the sequestration of global carbon and silica. Diatoms dominate primary production in the Arctic Ocean, where global climate change is causing increases in water temperature and in the partial pressure of CO2 (pCO2). Here we show that as water temperature increases diatoms become stressed, grow to smaller sizes, and decrease their silicification rates. But at higher pCO2, as the pH of seawater decreases, silica incorporation rates are increased. In a future warmer Arctic ocean diatoms may have a competitive advantage under increased ocean acidification, as increased pCO2 counteracts the adverse effects of increasing temperature on silicification and buffers its consequences in the biogeochemical cycles of carbon and silica.

  13. Acidification counteracts negative effects of warming on diatom silicification

    KAUST Repository

    Coello-Camba, Alexandra; Agusti, Susana

    2016-01-01

    Diatoms are a significant group contributing up to 40 % of annual primary production in the oceans. They have a special siliceous cell wall that, acting as a ballast, plays a key role in the sequestration of global carbon and silica. Diatoms dominate primary production in the Arctic Ocean, where global climate change is causing increases in water temperature and in the partial pressure of CO2 (pCO2). Here we show that as water temperature increases diatoms become stressed, grow to smaller sizes, and decrease their silicification rates. But at higher pCO2, as the pH of seawater decreases, silica incorporation rates are increased. In a future warmer Arctic ocean diatoms may have a competitive advantage under increased ocean acidification, as increased pCO2 counteracts the adverse effects of increasing temperature on silicification and buffers its consequences in the biogeochemical cycles of carbon and silica.

  14. Does comorbid anxiety counteract emotion recognition deficits in conduct disorder?

    Science.gov (United States)

    Short, Roxanna M L; Sonuga-Barke, Edmund J S; Adams, Wendy J; Fairchild, Graeme

    2016-08-01

    Previous research has reported altered emotion recognition in both conduct disorder (CD) and anxiety disorders (ADs) - but these effects appear to be of different kinds. Adolescents with CD often show a generalised pattern of deficits, while those with ADs show hypersensitivity to specific negative emotions. Although these conditions often cooccur, little is known regarding emotion recognition performance in comorbid CD+ADs. Here, we test the hypothesis that in the comorbid case, anxiety-related emotion hypersensitivity counteracts the emotion recognition deficits typically observed in CD. We compared facial emotion recognition across four groups of adolescents aged 12-18 years: those with CD alone (n = 28), ADs alone (n = 23), cooccurring CD+ADs (n = 20) and typically developing controls (n = 28). The emotion recognition task we used systematically manipulated the emotional intensity of facial expressions as well as fixation location (eye, nose or mouth region). Conduct disorder was associated with a generalised impairment in emotion recognition; however, this may have been modulated by group differences in IQ. AD was associated with increased sensitivity to low-intensity happiness, disgust and sadness. In general, the comorbid CD+ADs group performed similarly to typically developing controls. Although CD alone was associated with emotion recognition impairments, ADs and comorbid CD+ADs were associated with normal or enhanced emotion recognition performance. The presence of comorbid ADs appeared to counteract the effects of CD, suggesting a potentially protective role, although future research should examine the contribution of IQ and gender to these effects. © 2016 Association for Child and Adolescent Mental Health.

  15. Vitamin D counteracts Mycobacterium tuberculosis-induced cathelicidin downregulation in dendritic cells and allows Th1 differentiation and IFNγ secretion

    DEFF Research Database (Denmark)

    Rode, Anna K.O.; Kongsbak, Martin; Hansen, Marie M.

    2017-01-01

    -suppressive function inhibiting Th1 differentiation and production of IFNγ in T cells. The aim of this study was to investigate this apparent paradox. We studied naïve human CD4+ T cells activated either with CD3 and CD28 antibodies or with allogeneic dendritic cells (DC) stimulated with heat-killed M. tuberculosis...... (HKMT) or purified toll-like receptor (TLR) ligands. We show that vitamin D does not block differentiation of human CD4+ T cells to Th1 cells and that interleukin (IL)-12 partially counteracts vitamin D-mediated inhibition of IFNγ production promoting production of equal amounts of IFNγ in Th1 cells...... in patients with TB. At the same time, experimental data have shown that Th1 cells through production of IFNγ are crucial for cathelicidin release by macrophages, bacterial killing, and containment of M. tuberculosis in granulomas. Paradoxically, vitamin D has repeatedly been ascribed an immune...

  16. Alkylation induced cerebellar degeneration dependent on Aag and Parp1 does not occur via previously established cell death mechanisms.

    Directory of Open Access Journals (Sweden)

    Carrie M Margulies

    Full Text Available Alkylating agents are ubiquitous in our internal and external environments, causing DNA damage that contributes to mutations and cell death that can result in aging, tissue degeneration and cancer. Repair of methylated DNA bases occurs primarily through the base excision repair (BER pathway, a multi-enzyme pathway initiated by the alkyladenine DNA glycosylase (Aag, also known as Mpg. Previous work demonstrated that mice treated with the alkylating agent methyl methanesulfonate (MMS undergo cerebellar degeneration in an Aag-dependent manner, whereby increased BER initiation by Aag causes increased tissue damage that is dependent on activation of poly (ADP-ribose polymerase 1 (Parp1. Here, we dissect the molecular mechanism of cerebellar granule neuron (CGN sensitivity to MMS using primary ex vivo neuronal cultures. We first established a high-throughput fluorescent imaging method to assess primary neuron sensitivity to treatment with DNA damaging agents. Next, we verified that the alkylation sensitivity of CGNs is an intrinsic phenotype that accurately recapitulates the in vivo dependency of alkylation-induced CGN cell death on Aag and Parp1 activity. Finally, we show that MMS-induced CGN toxicity is independent of all the cellular events that have previously been associated with Parp-mediated toxicity, including mitochondrial depolarization, AIF translocation, calcium fluxes, and NAD+ consumption. We therefore believe that further investigation is needed to adequately describe all varieties of Parp-mediated cell death.

  17. Alkylation induced cerebellar degeneration dependent on Aag and Parp1 does not occur via previously established cell death mechanisms.

    Science.gov (United States)

    Margulies, Carrie M; Chaim, Isaac Alexander; Mazumder, Aprotim; Criscione, June; Samson, Leona D

    2017-01-01

    Alkylating agents are ubiquitous in our internal and external environments, causing DNA damage that contributes to mutations and cell death that can result in aging, tissue degeneration and cancer. Repair of methylated DNA bases occurs primarily through the base excision repair (BER) pathway, a multi-enzyme pathway initiated by the alkyladenine DNA glycosylase (Aag, also known as Mpg). Previous work demonstrated that mice treated with the alkylating agent methyl methanesulfonate (MMS) undergo cerebellar degeneration in an Aag-dependent manner, whereby increased BER initiation by Aag causes increased tissue damage that is dependent on activation of poly (ADP-ribose) polymerase 1 (Parp1). Here, we dissect the molecular mechanism of cerebellar granule neuron (CGN) sensitivity to MMS using primary ex vivo neuronal cultures. We first established a high-throughput fluorescent imaging method to assess primary neuron sensitivity to treatment with DNA damaging agents. Next, we verified that the alkylation sensitivity of CGNs is an intrinsic phenotype that accurately recapitulates the in vivo dependency of alkylation-induced CGN cell death on Aag and Parp1 activity. Finally, we show that MMS-induced CGN toxicity is independent of all the cellular events that have previously been associated with Parp-mediated toxicity, including mitochondrial depolarization, AIF translocation, calcium fluxes, and NAD+ consumption. We therefore believe that further investigation is needed to adequately describe all varieties of Parp-mediated cell death.

  18. A Systematic Analysis of Factors Localized to Damaged Chromatin Reveals PARP-Dependent Recruitment of Transcription Factors.

    Science.gov (United States)

    Izhar, Lior; Adamson, Britt; Ciccia, Alberto; Lewis, Jedd; Pontano-Vaites, Laura; Leng, Yumei; Liang, Anthony C; Westbrook, Thomas F; Harper, J Wade; Elledge, Stephen J

    2015-06-09

    Localization to sites of DNA damage is a hallmark of DNA damage response (DDR) proteins. To identify DDR factors, we screened epitope-tagged proteins for localization to sites of chromatin damaged by UV laser microirradiation and found >120 proteins that localize to damaged chromatin. These include the BAF tumor suppressor complex and the amyotrophic lateral sclerosis (ALS) candidate protein TAF15. TAF15 contains multiple domains that bind damaged chromatin in a poly-(ADP-ribose) polymerase (PARP)-dependent manner, suggesting a possible role as glue that tethers multiple PAR chains together. Many positives were transcription factors; > 70% of randomly tested transcription factors localized to sites of DNA damage, and of these, ∼90% were PARP dependent for localization. Mutational analyses showed that localization to damaged chromatin is DNA-binding-domain dependent. By examining Hoechst staining patterns at damage sites, we see evidence of chromatin decompaction that is PARP dependent. We propose that PARP-regulated chromatin remodeling at sites of damage allows transient accessibility of DNA-binding proteins. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  19. A Systematic Analysis of Factors Localized to Damaged Chromatin Reveals PARP-Dependent Recruitment of Transcription Factors

    Directory of Open Access Journals (Sweden)

    Lior Izhar

    2015-06-01

    Full Text Available Localization to sites of DNA damage is a hallmark of DNA damage response (DDR proteins. To identify DDR factors, we screened epitope-tagged proteins for localization to sites of chromatin damaged by UV laser microirradiation and found >120 proteins that localize to damaged chromatin. These include the BAF tumor suppressor complex and the amyotrophic lateral sclerosis (ALS candidate protein TAF15. TAF15 contains multiple domains that bind damaged chromatin in a poly-(ADP-ribose polymerase (PARP-dependent manner, suggesting a possible role as glue that tethers multiple PAR chains together. Many positives were transcription factors; > 70% of randomly tested transcription factors localized to sites of DNA damage, and of these, ∼90% were PARP dependent for localization. Mutational analyses showed that localization to damaged chromatin is DNA-binding-domain dependent. By examining Hoechst staining patterns at damage sites, we see evidence of chromatin decompaction that is PARP dependent. We propose that PARP-regulated chromatin remodeling at sites of damage allows transient accessibility of DNA-binding proteins.

  20. A Poly-ADP-Ribose Trigger Releases the Auto-Inhibition of a Chromatin Remodeling Oncogene

    DEFF Research Database (Denmark)

    Singh, Hari R; Nardozza, Aurelio P; Möller, Ingvar R

    2017-01-01

    DNA damage triggers chromatin remodeling by mechanisms that are poorly understood. The oncogene and chromatin remodeler ALC1/CHD1L massively decompacts chromatin in vivo yet is inactive prior to DNA-damage-mediated PARP1 induction. We show that the interaction of the ALC1 macrodomain......-macrodomain interactions, promotes an ungated conformation, and activates the remodeler's ATPase. ALC1 fragments lacking the regulatory macrodomain relax chromatin in vivo without requiring PARP1 activation. Further, the ATPase restricts the macrodomain's interaction with PARP1 under non-DNA damage conditions. Somatic...... cancer mutants disrupt ALC1's auto-inhibition and activate chromatin remodeling. Our data show that the NAD+-metabolite and nucleic acid PAR triggers ALC1 to drive chromatin relaxation. Modular allostery in this oncogene tightly controls its robust, DNA-damage-dependent activation....

  1. Menadione triggers cell death through ROS-dependent mechanisms involving PARP activation without requiring apoptosis.

    Science.gov (United States)

    Loor, Gabriel; Kondapalli, Jyothisri; Schriewer, Jacqueline M; Chandel, Navdeep S; Vanden Hoek, Terry L; Schumacker, Paul T

    2010-12-15

    Low levels of reactive oxygen species (ROS) can function as redox-active signaling messengers, whereas high levels of ROS induce cellular damage. Menadione generates ROS through redox cycling, and high concentrations trigger cell death. Previous work suggests that menadione triggers cytochrome c release from mitochondria, whereas other studies implicate the activation of the mitochondrial permeability transition pore as the mediator of cell death. We investigated menadione-induced cell death in genetically modified cells lacking specific death-associated proteins. In cardiomyocytes, oxidant stress was assessed using the redox sensor RoGFP, expressed in the cytosol or the mitochondrial matrix. Menadione elicited rapid oxidation in both compartments, whereas it decreased mitochondrial potential and triggered cytochrome c redistribution to the cytosol. Cell death was attenuated by N-acetylcysteine and exogenous glutathione or by overexpression of cytosolic or mitochondria-targeted catalase. By contrast, no protection was observed in cells overexpressing Cu,Zn-SOD or Mn-SOD. Overexpression of antiapoptotic Bcl-X(L) protected against staurosporine-induced cell death, but it failed to confer protection against menadione. Genetic deletion of Bax and Bak, cytochrome c, cyclophilin D, or caspase-9 conferred no protection against menadione-induced cell death. However, cells lacking PARP-1 showed a significant decrease in menadione-induced cell death. Thus, menadione induces cell death through the generation of oxidant stress in multiple subcellular compartments, yet cytochrome c, Bax/Bak, caspase-9, and cyclophilin D are dispensable for cell death in this model. These studies suggest that multiple redundant cell death pathways are activated by menadione, but that PARP plays an essential role in mediating each of them. Copyright © 2010 Elsevier Inc. All rights reserved.

  2. Inhibition of poly(ADP-ribose)polymerase-1 and DNA repair by uranium

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Karen L.; Dashner, Erica J. [Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States); Tsosie, Ranalda [Department of Chemistry and Biochemistry, University of Montana, Missoula, MT 59812 (United States); Cho, Young Mi [Department of Food and Nutrition, College of Human Ecology, Hanyang University, Seoul 133-791 (Korea, Republic of); Lewis, Johnnye [Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States); Community Environmental Health Program, University of New Mexico Health Sciences Center College of Pharmacy, Albuquerque, NM 87131 (United States); Hudson, Laurie G., E-mail: lhudson@salud.unm.edu [Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States)

    2016-01-15

    Uranium has radiological and non-radiological effects within biological systems and there is increasing evidence for genotoxic and carcinogenic properties attributable to uranium through its heavy metal properties. In this study, we report that low concentrations of uranium (as uranyl acetate; < 10 μM) is not cytotoxic to human embryonic kidney cells or normal human keratinocytes; however, uranium exacerbates DNA damage and cytotoxicity induced by hydrogen peroxide, suggesting that uranium may inhibit DNA repair processes. Concentrations of uranyl acetate in the low micromolar range inhibited the zinc finger DNA repair protein poly(ADP-ribose) polymerase (PARP)-1 and caused zinc loss from PARP-1 protein. Uranyl acetate exposure also led to zinc loss from the zinc finger DNA repair proteins Xeroderma Pigmentosum, Complementation Group A (XPA) and aprataxin (APTX). In keeping with the observed inhibition of zinc finger function of DNA repair proteins, exposure to uranyl acetate enhanced retention of induced DNA damage. Co-incubation of uranyl acetate with zinc largely overcame the impact of uranium on PARP-1 activity and DNA damage. These findings present evidence that low concentrations of uranium can inhibit DNA repair through disruption of zinc finger domains of specific target DNA repair proteins. This may provide a mechanistic basis to account for the published observations that uranium exposure is associated with DNA repair deficiency in exposed human populations. - Highlights: • Low micromolar concentration of uranium inhibits polymerase-1 (PARP-1) activity. • Uranium causes zinc loss from multiple DNA repair proteins. • Uranium enhances retention of DNA damage caused by ultraviolet radiation. • Zinc reverses the effects of uranium on PARP activity and DNA damage repair.

  3. A Poly-ADP-Ribose Trigger Releases the Auto-Inhibition of a Chromatin Remodeling Oncogene.

    Science.gov (United States)

    Singh, Hari R; Nardozza, Aurelio P; Möller, Ingvar R; Knobloch, Gunnar; Kistemaker, Hans A V; Hassler, Markus; Harrer, Nadine; Blessing, Charlotte; Eustermann, Sebastian; Kotthoff, Christiane; Huet, Sébastien; Mueller-Planitz, Felix; Filippov, Dmitri V; Timinszky, Gyula; Rand, Kasper D; Ladurner, Andreas G

    2017-12-07

    DNA damage triggers chromatin remodeling by mechanisms that are poorly understood. The oncogene and chromatin remodeler ALC1/CHD1L massively decompacts chromatin in vivo yet is inactive prior to DNA-damage-mediated PARP1 induction. We show that the interaction of the ALC1 macrodomain with the ATPase module mediates auto-inhibition. PARP1 activation suppresses this inhibitory interaction. Crucially, release from auto-inhibition requires a poly-ADP-ribose (PAR) binding macrodomain. We identify tri-ADP-ribose as a potent PAR-mimic and synthetic allosteric effector that abrogates ATPase-macrodomain interactions, promotes an ungated conformation, and activates the remodeler's ATPase. ALC1 fragments lacking the regulatory macrodomain relax chromatin in vivo without requiring PARP1 activation. Further, the ATPase restricts the macrodomain's interaction with PARP1 under non-DNA damage conditions. Somatic cancer mutants disrupt ALC1's auto-inhibition and activate chromatin remodeling. Our data show that the NAD + -metabolite and nucleic acid PAR triggers ALC1 to drive chromatin relaxation. Modular allostery in this oncogene tightly controls its robust, DNA-damage-dependent activation. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Survivin counteracts the therapeutic effect of microtubule de-stabilizers by stabilizing tubulin polymers

    Directory of Open Access Journals (Sweden)

    Hsieh Hsing-Pang

    2009-07-01

    stability of microtubules, but not with caspases inhibition. Over-expression of survivin counteracts the therapeutic effect of microtubule de-stabilizer BPR0L075 probably by stabilizing tubulin polymers, instead of the inhibition of caspase activity in cancer cells. Besides microtubule-related caspase-dependent cell death, caspase-independent mitotic cell death could be initiated in survivin/BPR0L075 combination treatments. We suggest that combining microtubule de-stabilizers with a survivin inhibitor may attribute to a better clinical outcome than the use of anti-mitotic monotherapy in clinical situations.

  5. Structural basis for the inhibition of poly(ADP-ribose) polymerases 1 and 2 by BMN 673, a potent inhibitor derived from dihydropyridophthalazinone

    Energy Technology Data Exchange (ETDEWEB)

    Aoyagi-Scharber, Mika, E-mail: maoyagi@bmrn.com [BioMarin Pharmaceutical Inc., 105 Digital Drive, Novato, CA 94949 (United States); Gardberg, Anna S. [Emerald BioStructures, 7869 NE Day Road West, Bainbridge Island, WA 98110 (United States); Yip, Bryan K.; Wang, Bing; Shen, Yuqiao; Fitzpatrick, Paul A. [BioMarin Pharmaceutical Inc., 105 Digital Drive, Novato, CA 94949 (United States)

    2014-08-29

    BMN 673, a novel PARP1/2 inhibitor in clinical development with substantial tumor cytotoxicity, forms extensive hydrogen-bonding and π-stacking in the nicotinamide pocket, with its unique disubstituted scaffold extending towards the less conserved edges of the pocket. These interactions might provide structural insight into the ability of BMN 673 to both inhibit catalysis and affect DNA-binding activity. Poly(ADP-ribose) polymerases 1 and 2 (PARP1 and PARP2), which are involved in DNA damage response, are targets of anticancer therapeutics. BMN 673 is a novel PARP1/2 inhibitor with substantially increased PARP-mediated tumor cytotoxicity and is now in later-stage clinical development for BRCA-deficient breast cancers. In co-crystal structures, BMN 673 is anchored to the nicotinamide-binding pocket via an extensive network of hydrogen-bonding and π-stacking interactions, including those mediated by active-site water molecules. The novel di-branched scaffold of BMN 673 extends the binding interactions towards the outer edges of the pocket, which exhibit the least sequence homology among PARP enzymes. The crystallographic structural analyses reported here therefore not only provide critical insights into the molecular basis for the exceptionally high potency of the clinical development candidate BMN 673, but also new opportunities for increasing inhibitor selectivity.

  6. Structural basis for the inhibition of poly(ADP-ribose) polymerases 1 and 2 by BMN 673, a potent inhibitor derived from dihydropyridophthalazinone

    International Nuclear Information System (INIS)

    Aoyagi-Scharber, Mika; Gardberg, Anna S.; Yip, Bryan K.; Wang, Bing; Shen, Yuqiao; Fitzpatrick, Paul A.

    2014-01-01

    BMN 673, a novel PARP1/2 inhibitor in clinical development with substantial tumor cytotoxicity, forms extensive hydrogen-bonding and π-stacking in the nicotinamide pocket, with its unique disubstituted scaffold extending towards the less conserved edges of the pocket. These interactions might provide structural insight into the ability of BMN 673 to both inhibit catalysis and affect DNA-binding activity. Poly(ADP-ribose) polymerases 1 and 2 (PARP1 and PARP2), which are involved in DNA damage response, are targets of anticancer therapeutics. BMN 673 is a novel PARP1/2 inhibitor with substantially increased PARP-mediated tumor cytotoxicity and is now in later-stage clinical development for BRCA-deficient breast cancers. In co-crystal structures, BMN 673 is anchored to the nicotinamide-binding pocket via an extensive network of hydrogen-bonding and π-stacking interactions, including those mediated by active-site water molecules. The novel di-branched scaffold of BMN 673 extends the binding interactions towards the outer edges of the pocket, which exhibit the least sequence homology among PARP enzymes. The crystallographic structural analyses reported here therefore not only provide critical insights into the molecular basis for the exceptionally high potency of the clinical development candidate BMN 673, but also new opportunities for increasing inhibitor selectivity

  7. Associative Interactions in Crowded Solutions of Biopolymers Counteract Depletion Effects.

    Science.gov (United States)

    Groen, Joost; Foschepoth, David; te Brinke, Esra; Boersma, Arnold J; Imamura, Hiromi; Rivas, Germán; Heus, Hans A; Huck, Wilhelm T S

    2015-10-14

    The cytosol of Escherichia coli is an extremely crowded environment, containing high concentrations of biopolymers which occupy 20-30% of the available volume. Such conditions are expected to yield depletion forces, which strongly promote macromolecular complexation. However, crowded macromolecule solutions, like the cytosol, are very prone to nonspecific associative interactions that can potentially counteract depletion. It remains unclear how the cytosol balances these opposing interactions. We used a FRET-based probe to systematically study depletion in vitro in different crowded environments, including a cytosolic mimic, E. coli lysate. We also studied bundle formation of FtsZ protofilaments under identical crowded conditions as a probe for depletion interactions at much larger overlap volumes of the probe molecule. The FRET probe showed a more compact conformation in synthetic crowding agents, suggesting strong depletion interactions. However, depletion was completely negated in cell lysate and other protein crowding agents, where the FRET probe even occupied slightly more volume. In contrast, bundle formation of FtsZ protofilaments proceeded as readily in E. coli lysate and other protein solutions as in synthetic crowding agents. Our experimental results and model suggest that, in crowded biopolymer solutions, associative interactions counterbalance depletion forces for small macromolecules. Furthermore, the net effects of macromolecular crowding will be dependent on both the size of the macromolecule and its associative interactions with the crowded background.

  8. Retrieval and sleep both counteract the forgetting of spatial information.

    Science.gov (United States)

    Antony, James W; Paller, Ken A

    2018-06-01

    Repeatedly studying information is a good way to strengthen memory storage. Nevertheless, testing recall often produces superior long-term retention. Demonstrations of this testing effect, typically with verbal stimuli, have shown that repeated retrieval through testing reduces forgetting. Sleep also benefits memory storage, perhaps through repeated retrieval as well. That is, memories may generally be subject to forgetting that can be counteracted when memories become reactivated, and there are several types of reactivation: (i) via intentional restudying, (ii) via testing, (iii) without provocation during wake, or (iv) during sleep. We thus measured forgetting for spatial material subjected to repeated study or repeated testing followed by retention intervals with sleep versus wake. Four groups of subjects learned a set of visual object-location associations and either restudied the associations or recalled locations given the objects as cues. We found the advantage for restudied over retested information was greater in the PM than AM group. Additional groups tested at 5-min and 1-wk retention intervals confirmed previous findings of greater relative benefits for restudying in the short-term and for retesting in the long-term. Results overall support the conclusion that repeated reactivation through testing or sleeping stabilizes information against forgetting. © 2018 Antony and Paller; Published by Cold Spring Harbor Laboratory Press.

  9. Subarray-based FDA radar to counteract deceptive ECM signals

    Science.gov (United States)

    Abdalla, Ahmed; Wang, Wen-Qin; Yuan, Zhao; Mohamed, Suhad; Bin, Tang

    2016-12-01

    In recent years, the frequency diverse array (FDA) radar concept has attracted extensive attention, as it may benefit from a small frequency increment, compared to the carrier frequency across the array elements and thereby achieve an array factor that is a function of the angle, the time, and the range which is superior to the conventional phase array radar (PAR). However, limited effort on the subject of FDA in electronic countermeasure scenarios, especially in the presence of mainbeam deceptive jamming, has been published. Basic FDA is not desirable for anti-jamming applications, due to the range-angle coupling response of targets. In this paper, a novel method based on subarrayed FDA signal processing is proposed to counteract deceptive ECM signals. We divide the FDA array into multiple subarrays, each of which employs a distinct frequency increment. As a result, in the subarray-based FDA, the desired target can be distinguished at subarray level in joint range-angle-Doppler domain by utilizing the fact that the jammer generates false targets with the same ranges to each subarray without reparations. The performance assessment shows that the proposed solution is effective for deceptive ECM targets suppression. The effectiveness is verified by simulation results.

  10. Counteracting the Influence of Peer Smoking on YouTube.

    Science.gov (United States)

    Romer, Daniel; Jamieson, Patrick E; Jamieson, Kathleen Hall; Jones, Christopher; Sherr, Susan

    2017-04-01

    YouTube, a popular online site for user-generated content, is emerging as a powerful source of peer modeling of smoking. Previous research suggests that in counteracting such influence, health messages may inadvertently increase the perceived prevalence of drug use (a descriptive norm) without reducing its acceptability (injunctive norm). This research tested the ability of health messages to reduce the social acceptability of peer smoking on YouTube despite enhancing its perceived prevalence. In an online experiment with 999 adolescents, participants were randomly assigned to view one of two videos: (a) a mosaic displaying a variety of YouTube videos of adolescents smoking followed by a message about the mortality risk to those smokers, or (b) a control video on a health topic unrelated to smoking. Although exposure to the adolescent YouTube smokers increased perceived prevalence among some participants, it simultaneously increased beliefs about smoking's adverse health outcomes and negative attitudes toward smoking, effects that were associated with reductions in injunctive norms of social acceptability. Interventions that communicate the severity and scope of health risks associated with smoking may undercut the descriptive normative effects of peer modeling of smoking on social media sites such as YouTube.

  11. Counteracting structural errors in ensemble forecast of influenza outbreaks.

    Science.gov (United States)

    Pei, Sen; Shaman, Jeffrey

    2017-10-13

    For influenza forecasts generated using dynamical models, forecast inaccuracy is partly attributable to the nonlinear growth of error. As a consequence, quantification of the nonlinear error structure in current forecast models is needed so that this growth can be corrected and forecast skill improved. Here, we inspect the error growth of a compartmental influenza model and find that a robust error structure arises naturally from the nonlinear model dynamics. By counteracting these structural errors, diagnosed using error breeding, we develop a new forecast approach that combines dynamical error correction and statistical filtering techniques. In retrospective forecasts of historical influenza outbreaks for 95 US cities from 2003 to 2014, overall forecast accuracy for outbreak peak timing, peak intensity and attack rate, are substantially improved for predicted lead times up to 10 weeks. This error growth correction method can be generalized to improve the forecast accuracy of other infectious disease dynamical models.Inaccuracy of influenza forecasts based on dynamical models is partly due to nonlinear error growth. Here the authors address the error structure of a compartmental influenza model, and develop a new improved forecast approach combining dynamical error correction and statistical filtering techniques.

  12. The multikinase inhibitor Sorafenib displays significant antiproliferative effects and induces apoptosis via caspase 3, 7 and PARP in B- and T-lymphoblastic cells

    International Nuclear Information System (INIS)

    Schult, Catrin; Boldt, Sonja; Wolkenhauer, Olaf; Neri, Luca Maria; Freund, Mathias; Junghanss, Christian; Dahlhaus, Meike; Ruck, Sabine; Sawitzky, Mandy; Amoroso, Francesca; Lange, Sandra; Etro, Daniela; Glass, Aenne; Fuellen, Georg

    2010-01-01

    Targeted therapy approaches have been successfully introduced into the treatment of several cancers. The multikinase inhibitor Sorafenib has antitumor activity in solid tumors and its effects on acute lymphoblastic leukemia (ALL) cells are still unclear. ALL cell lines (SEM, RS4;11 and Jurkat) were treated with Sorafenib alone or in combination with cytarabine, doxorubicin or RAD001. Cell count, apoptosis and necrosis rates, cell cycle distribution, protein phosphorylation and metabolic activity were determined. Sorafenib inhibited the proliferation of ALL cells by cell cycle arrest accompanied by down-regulation of CyclinD3 and CDK4. Furthermore, Sorafenib initiated apoptosis by cleavage of caspases 3, 7 and PARP. Apoptosis and necrosis rates increased significantly with most pronounced effects after 96 h. Antiproliferative effects of Sorafenib were associated with a decreased phosphorylation of Akt (Ser473 and Thr308), FoxO3A (Thr32) and 4EBP-1 (Ser65 and Thr70) as early as 0.5 h after treatment. Synergistic effects were seen when Sorafenib was combined with other cytotoxic drugs or a mTOR inhibitor emphasizing the Sorafenib effect. Sorafenib displays significant antileukemic activity in vitro by inducing cell cycle arrest and apoptosis. Furthermore, it influences PI3K/Akt/mTOR signaling in ALL cells

  13. Poly(ADP-ribose) polymerase inhibition reduces tumor necrosis factor-induced inflammatory response in rheumatoid synovial fibroblasts

    NARCIS (Netherlands)

    García, S.; Bodaño, A.; Pablos, J. L.; Gómez-Reino, J. J.; Conde, C.

    2008-01-01

    To investigate the effect of poly(ADP-ribose) polymerase (PARP) inhibition on the production of inflammatory mediators and proliferation in tumour necrosis factor (TNF)-stimulated fibroblast-like synoviocytes (FLS) from patients with rheumatoid arthritis (RA). Cultured FLS from patients with RA were

  14. Effect of 3-aminobenzamide, PARP inhibitor, on matrix metalloproteinase-9 level in plasma and brain of ischemic stroke model

    International Nuclear Information System (INIS)

    Koh, Seong-Ho; Chang, Dae-Il; Kim, Hee-Tae; Kim, Juhan; Kim, Myung-Ho; Kim, Kyung Suk; Bae, Inhee; Kim, Haekwon; Kim, Dong Won; Kim, Seung Hyun

    2005-01-01

    We investigated the effect of poly(ADP-ribose) polymerase (PARP) inhibitor on the levels of plasma and brain matrix metalloproteinase-9 (MMP-9) and the expression of nuclear factor kappa B (NF-κB) during experimental focal cerebral ischemia. The 3-aminobenzamide (3-AB), a PARP inhibitor, and saline were administered to 80 Sprague-Dawley rats [3-AB group; 5 rats for plasma sampling, 35 for brain sampling, and 40 for TTC staining] and to 85 rats (10, 35, and 40, respectively), respectively, 10 min before the occlusion of the left middle cerebral artery (MCAo) for 2 h. Infarct volume was measured by TTC staining, the serial levels of plasma and brain MMP-9 were measured by zymography just before and 2, 4, 8, 24, 48, and 72 h after MCAo, brain NF-κB activity was determined by Western blotting, and neutrophil infiltration was evaluated by assessing myeloperoxidase activity. Compared with control group, the levels of plasma and brain MMP-9, brain NF-κB, and MPO activities were significantly reduced in 3-AB group at each time point (p < 0.05). Plasma MMP-9 increased maximally at 4 h and then decreased rapidly, brain MMP-9 increased maximally at 24 h and persisted until 72 h, and NF-κB increased maximally at 24 h and then decreased slowly in both groups. Therefore, the PARP inhibitor reduces the expression of MMP-9 and NF-κB and the infiltration of neutrophils in ischemic stroke

  15. Risk of severe hematologic toxicities in cancer patients treated with PARP inhibitors: results of monotherapy and combination therapy trials

    Directory of Open Access Journals (Sweden)

    Alecu I

    2018-02-01

    Full Text Available Iulian Alecu, Tsveta Milenkova, Simon R Turner Research and Development, AstraZeneca UK Limited, Cambridge, UKThe tolerability profile of PARP inhibitors often includes hematologic toxicities, and the characterization of these adverse events is important to allow effective management by clinicians. Zhou et al1 recently carried out a meta-analysis of the incidence and relative risks of severe neutropenia, thrombocytopenia, and anemia events in 12 randomized controlled trials of PARP inhibitors, either as monotherapy or in combination with chemotherapy or radiotherapy. The authors concluded that olaparib resulted in a higher incidence of severe (common terminology criteria for adverse events [CTCAE] grade $3 neutropenia when compared with niraparib and veliparib; however, these conclusions are based on inappropriate and incomplete comparisons of hematologic toxicity with olaparib or veliparib in combination with myelotoxic chemotherapy versus niraparib monotherapy. While both monotherapy and combination therapy olaparib studies are discussed in the paper, the neutropenia analysis is based on olaparib data solely from studies in combination with paclitaxel or paclitaxel plus carboplatin. In order to inform the practicing clinician of the relative risk of hematologic toxicity associated with different PARP inhibitors, direct comparison needs to be conducted based on monotherapy, where applicable, as per the approved drug indication, otherwise the reader is given misleading information.View the original paper by Zhou et al.

  16. Webinar Presentation: Vitamins, Minerals and Metals: Do Healthy Diets Counteract Health Effects of Toxicants?

    Science.gov (United States)

    This presentation, Vitamins, Minerals and Metals: Do Healthy Diets Counteract Health Effects of Toxicants?, was given at the NIEHS/EPA Children's Centers 2015 Webinar Series: Food and Children's Health held on Dec. 9, 2015.

  17. Counteracting 16-QAM Optical Fiber Transmission Impairments With Iterative Turbo Equalization

    DEFF Research Database (Denmark)

    Arlunno, Valeria; Caballero Jambrina, Antonio; Borkowski, Robert

    2013-01-01

    A turbo equalization (TE) scheme based on convolutional code and normalized least mean square equalizer for coherent optical communication links is proposed and experimentally demonstrated. The proposed iterative TE technique is proved effective for counteracting polarization-division-multiplexin......A turbo equalization (TE) scheme based on convolutional code and normalized least mean square equalizer for coherent optical communication links is proposed and experimentally demonstrated. The proposed iterative TE technique is proved effective for counteracting polarization...

  18. Increased transcript level of poly(ADP-ribose) polymerase (PARP-1) in human tricuspid compared with bicuspid aortic valves correlates with the stenosis severity

    International Nuclear Information System (INIS)

    Nagy, Edit; Caidahl, Kenneth; Franco-Cereceda, Anders; Bäck, Magnus

    2012-01-01

    Highlights: ► Oxidative stress has been implicated in the pathomechanism of calcific aortic valve stenosis. ► We assessed the transcript levels for PARP-1 (poly(ADP-ribose) polymerase), acts as a DNA damage nick sensor in stenotic valves. ► Early stage of diseased tricuspid valves exhibited higher mRNA levels for PARP-1 compared to bicuspid valves. ► The mRNA levels for PARP-1 inversely correlated with the clinical stenosis severity in tricuspid valves. ► Our data demonstrated that DNA damage pathways might be associated with stenosis severity only in tricuspid valves. -- Abstract: Oxidative stress may contribute to the hemodynamic progression of aortic valve stenosis, and is associated with activation of the nuclear enzyme poly(ADP-ribose) polymerase (PARP) 1. The aim of the present study was to assess the transcriptional profile and the topological distribution of PARP-1 in human aortic valves, and its relation to the stenosis severity. Human stenotic aortic valves were obtained from 46 patients undergoing aortic valve replacement surgery and used for mRNA extraction followed by quantitative real-time PCR to correlate the PARP-1 expression levels with the non invasive hemodynamic parameters quantifying the stenosis severity. Primary isolated valvular interstitial cells (VICs) were used to explore the effects of cytokines and leukotriene C 4 (LTC 4 ) on valvular PARP-1 expression. The thickened areas of stenotic valves with tricuspid morphology expressed significantly higher levels of PARP-1 mRNA compared with the corresponding part of bicuspid valves (0.501 vs 0.243, P = 0.01). Furthermore, the quantitative gene expression levels of PARP-1 were inversely correlated with the aortic valve area (AVA) (r = −0.46, P = 0.0469) and AVA indexed for body surface area (BSA) (r = −0.498; P = 0.0298) only in tricuspid aortic valves. LTC 4 (1 nM) significantly elevated the mRNA levels of PARP-1 by 2.38-fold in VICs. Taken together, these data suggest that

  19. Nilotinib Enhances Tumor Angiogenesis and Counteracts VEGFR2 Blockade in an Orthotopic Breast Cancer Xenograft Model with Desmoplastic Response

    Directory of Open Access Journals (Sweden)

    Sara Zafarnia

    2017-11-01

    Full Text Available Vascular endothelial growth factor (VEGF/VEGF receptor (VEGFR-targeted therapies predominantly affect nascent, immature tumor vessels. Since platelet-derived growth factor receptor (PDGFR blockade inhibits vessel maturation and thus increases the amount of immature tumor vessels, we evaluated whether the combined PDGFR inhibition by nilotinib and VEGFR2 blockade by DC101 has synergistic therapy effects in a desmoplastic breast cancer xenograft model. In this context, besides immunohistological evaluation, molecular ultrasound imaging with BR55, the clinically used VEGFR2-targeted microbubbles, was applied to monitor VEGFR2-positive vessels noninvasively and to assess the therapy effects on tumor angiogenesis. DC101 treatment alone inhibited tumor angiogenesis, resulting in lower tumor growth and in significantly lower vessel density than in the control group after 14 days of therapy. In contrast, nilotinib inhibited vessel maturation but enhanced VEGFR2 expression, leading to markedly increased tumor volumes and a significantly higher vessel density. The combination of both drugs led to an almost similar tumor growth as in the DC101 treatment group, but VEGFR2 expression and microvessel density were higher and comparable to the controls. Further analyses revealed significantly higher levels of tumor cell–derived VEGF in nilotinib-treated tumors. In line with this, nilotinib, especially in low doses, induced an upregulation of VEGF and IL-6 mRNA in the tumor cells in vitro, thus providing an explanation for the enhanced angiogenesis observed in nilotinib-treated tumors in vivo. These findings suggest that nilotinib inhibits vessel maturation but counteracts the effects of antiangiogenic co-therapy by enhancing VEGF expression by the tumor cells and stimulating tumor angiogenesis.

  20. Expression of DNA Damage Response Molecules PARP1, γH2AX, BRCA1, and BRCA2 Predicts Poor Survival of Breast Carcinoma Patients

    Directory of Open Access Journals (Sweden)

    See-Hyoung Park

    2015-08-01

    Full Text Available BACKGROUND: Poly(ADP-ribose polymerase 1 (PARP1, γH2AX, BRCA1, and BRCA2 are conventional molecular indicators of DNA damage in cells and are often overexpressed in various cancers. In this study, we aimed, using immunohistochemical detection, whether the co-expression of PARP1, γH2AX, BRCA1, and BRCA2 in breast carcinoma (BCA tissue can provide more reliable prediction of survival of BCA patients. MATERIALS AND METHODS: We investigated immunohistochemical expression and prognostic significance of the expression of PARP1, γH2AX, BRCA1, and BRCA2 in 192 cases of BCAs. RESULTS: The expression of these four molecules predicted earlier distant metastatic relapse, shorter overall survival (OS, and relapse-free survival (RFS by univariate analysis. Multivariate analysis revealed the expression of PARP1, γH2AX, and BRCA2 as independent poor prognostic indicators of OS and RFS. In addition, the combined expressional pattern of BRCA1, BRCA2, PARP1, and γH2AX (CSbbph was an additional independent prognostic predictor for OS (P < .001 and RFS (P < .001. The 10-year OS rate was 95% in the CSbbph-low (CSbbph scores 0 and 1 subgroup, but that was only 35% in the CSbbph-high (CSbbph score 4 subgroup. CONCLUSION: This study has demonstrated that the individual and combined expression patterns of PARP1, γH2AX, BRCA1, and BRCA2 could be helpful in determining an accurate prognosis for BCA patients and for the selection of BCA patients who could potentially benefit from anti-PARP1 therapy with a combination of genotoxic chemotherapeutic agents.

  1. Postconditioning with inhaled carbon monoxide counteracts apoptosis and neuroinflammation in the ischemic rat retina.

    Directory of Open Access Journals (Sweden)

    Nils Schallner

    Full Text Available Ischemia and reperfusion injury (I/R of neuronal structures and organs is associated with increased morbidity and mortality due to neuronal cell death. We hypothesized that inhalation of carbon monoxide (CO after I/R injury ('postconditioning' would protect retinal ganglion cells (RGC.Retinal I/R injury was performed in Sprague-Dawley rats (n = 8 by increasing ocular pressure (120 mmHg, 1 h. Rats inhaled room air or CO (250 ppm for 1 h immediately following ischemia or with 1.5 and 3 h latency. Retinal tissue was harvested to analyze Bcl-2, Bax, Caspase-3, HO-1 expression and phosphorylation of the nuclear transcription factor (NF-κB, p38 and ERK-1/2 MAPK. NF-κB activation was determined and inhibition of ERK-1/2 was performed using PD98059 (2 mg/kg. Densities of fluorogold prelabeled RGC were analyzed 7 days after injury. Microglia, macrophage and Müller cell activation and proliferation were evaluated by Iba-1, GFAP and Ki-67 staining.Inhalation of CO after I/R inhibited Bax and Caspase-3 expression (Bax: 1.9 ± 0.3 vs. 1.4 ± 0.2, p = 0.028; caspase-3: 2.0 ± 0.2 vs. 1.5 ± 0.1, p = 0.007; mean ± S.D., fold induction at 12 h, while expression of Bcl-2 was induced (1.2 ± 0.2 vs. 1.6 ± 0.2, p = 0.001; mean ± S.D., fold induction at 12 h. CO postconditioning suppressed retinal p38 phosphorylation (p = 0.023 at 24 h and induced the phosphorylation of ERK-1/2 (p<0.001 at 24 h. CO postconditioning inhibited the expression of HO-1. The activation of NF-κB, microglia and Müller cells was potently inhibited by CO as well as immigration of proliferative microglia and macrophages into the retina. CO protected I/R-injured RGC with a therapeutic window at least up to 3 h (n = 8; RGC/mm(2; mean ± S.D.: 1255 ± 327 I/R only vs. 1956 ± 157 immediate CO treatment, vs. 1830 ± 109 1.5 h time lag and vs. 1626 ± 122 3 h time lag; p<0.001. Inhibition of ERK-1/2 did not counteract the CO effects (RGC/mm(2: 1956 ± 157 vs. 1931 ± 124, mean ± S.D., p

  2. MDM2 Antagonists Counteract Drug-Induced DNA Damage

    Directory of Open Access Journals (Sweden)

    Anna E. Vilgelm

    2017-10-01

    Full Text Available Antagonists of MDM2-p53 interaction are emerging anti-cancer drugs utilized in clinical trials for malignancies that rarely mutate p53, including melanoma. We discovered that MDM2-p53 antagonists protect DNA from drug-induced damage in melanoma cells and patient-derived xenografts. Among the tested DNA damaging drugs were various inhibitors of Aurora and Polo-like mitotic kinases, as well as traditional chemotherapy. Mitotic kinase inhibition causes mitotic slippage, DNA re-replication, and polyploidy. Here we show that re-replication of the polyploid genome generates replicative stress which leads to DNA damage. MDM2-p53 antagonists relieve replicative stress via the p53-dependent activation of p21 which inhibits DNA replication. Loss of p21 promoted drug-induced DNA damage in melanoma cells and enhanced anti-tumor activity of therapy combining MDM2 antagonist with mitotic kinase inhibitor in mice. In summary, MDM2 antagonists may reduce DNA damaging effects of anti-cancer drugs if they are administered together, while targeting p21 can improve the efficacy of such combinations.

  3. Inhibition of poly(ADP-ribose)polymerase-1 and DNA repair by uranium.

    Science.gov (United States)

    Cooper, Karen L; Dashner, Erica J; Tsosie, Ranalda; Cho, Young Mi; Lewis, Johnnye; Hudson, Laurie G

    2016-01-15

    Uranium has radiological and non-radiological effects within biological systems and there is increasing evidence for genotoxic and carcinogenic properties attributable to uranium through its heavy metal properties. In this study, we report that low concentrations of uranium (as uranyl acetate; uranium exacerbates DNA damage and cytotoxicity induced by hydrogen peroxide, suggesting that uranium may inhibit DNA repair processes. Concentrations of uranyl acetate in the low micromolar range inhibited the zinc finger DNA repair protein poly(ADP-ribose) polymerase (PARP)-1 and caused zinc loss from PARP-1 protein. Uranyl acetate exposure also led to zinc loss from the zinc finger DNA repair proteins Xeroderma Pigmentosum, Complementation Group A (XPA) and aprataxin (APTX). In keeping with the observed inhibition of zinc finger function of DNA repair proteins, exposure to uranyl acetate enhanced retention of induced DNA damage. Co-incubation of uranyl acetate with zinc largely overcame the impact of uranium on PARP-1 activity and DNA damage. These findings present evidence that low concentrations of uranium can inhibit DNA repair through disruption of zinc finger domains of specific target DNA repair proteins. This may provide a mechanistic basis to account for the published observations that uranium exposure is associated with DNA repair deficiency in exposed human populations. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Interleukin-6 counteracts therapy-induced cellular oxidative stress in multiple myeloma by up-regulating manganese superoxide dismutase.

    Science.gov (United States)

    Brown, Charles O; Salem, Kelley; Wagner, Brett A; Bera, Soumen; Singh, Neeraj; Tiwari, Ajit; Choudhury, Amit; Buettner, Garry R; Goel, Apollina

    2012-06-15

    IL (interleukin)-6, an established growth factor for multiple myeloma cells, induces myeloma therapy resistance, but the resistance mechanisms remain unclear. The present study determines the role of IL-6 in re-establishing intracellular redox homoeostasis in the context of myeloma therapy. IL-6 treatment increased myeloma cell resistance to agents that induce oxidative stress, including IR (ionizing radiation) and Dex (dexamethasone). Relative to IR alone, myeloma cells treated with IL-6 plus IR demonstrated reduced annexin/propidium iodide staining, caspase 3 activation, PARP [poly(ADP-ribose) polymerase] cleavage and mitochondrial membrane depolarization with increased clonogenic survival. IL-6 combined with IR or Dex increased early intracellular pro-oxidant levels that were causally related to activation of NF-κB (nuclear factor κB) as determined by the ability of N-acetylcysteine to suppress both pro-oxidant levels and NF-κB activation. In myeloma cells, upon combination with hydrogen peroxide treatment, relative to TNF (tumour necrosis factor)-α, IL-6 induced an early perturbation in reduced glutathione level and increased NF-κB-dependent MnSOD (manganese superoxide dismutase) expression. Furthermore, knockdown of MnSOD suppressed the IL-6-induced myeloma cell resistance to radiation. MitoSOX Red staining showed that IL-6 treatment attenuated late mitochondrial oxidant production in irradiated myeloma cells. The present study provides evidence that increases in MnSOD expression mediate IL-6-induced resistance to Dex and radiation in myeloma cells. The results of the present study indicate that inhibition of antioxidant pathways could enhance myeloma cell responses to radiotherapy and/or chemotherapy.

  5. Regulation of HFE expression by poly(ADP-ribose) polymerase-1 (PARP1) through an inverted repeat DNA sequence in the distal promoter.

    Science.gov (United States)

    Pelham, Christopher; Jimenez, Tamara; Rodova, Marianna; Rudolph, Angela; Chipps, Elizabeth; Islam, M Rafiq

    2013-12-01

    Hereditary hemochromatosis (HH) is a common autosomal recessive disorder of iron overload among Caucasians of northern European descent. Over 85% of all cases with HH are due to mutations in the hemochromatosis protein (HFE) involved in iron metabolism. Although the importance in iron homeostasis is well recognized, the mechanism of sensing and regulating iron absorption by HFE, especially in the absence of iron response element in its gene, is not fully understood. In this report, we have identified an inverted repeat sequence (ATGGTcttACCTA) within 1700bp (-1675/+35) of the HFE promoter capable to form cruciform structure that binds PARP1 and strongly represses HFE promoter. Knockdown of PARP1 increases HFE mRNA and protein. Similarly, hemin or FeCl3 treatments resulted in increase in HFE expression by reducing nuclear PARP1 pool via its apoptosis induced cleavage, leading to upregulation of the iron regulatory hormone hepcidin mRNA. Thus, PARP1 binding to the inverted repeat sequence on the HFE promoter may serve as a novel iron sensing mechanism as increased iron level can trigger PARP1 cleavage and relief of HFE transcriptional repression. © 2013.

  6. Effect of APE1 T2197G (Asp148Glu Polymorphism on APE1, XRCC1, PARP1 and OGG1 Expression in Patients with Colorectal Cancer

    Directory of Open Access Journals (Sweden)

    Juliana C. Santos

    2014-09-01

    Full Text Available It has been hypothesized that genetic variation in base excision repair (BER might modify colorectal adenoma risk. Thus, we evaluated the influence of APE1 T2197G (Asp148Glu polymorphism on APE1, XRCC1, PARP1 and OGG1 expression in normal and tumor samples from patients with colorectal cancer. The results indicate a downregulation of OGG1 and an upregulation of XRCC1 expression in tumor tissue. Regarding the anatomical location of APE1, OGG1 and PARP-1, a decrease in gene expression was observed among patients with cancer in the rectum. In patients with or without some degree of tumor invasion, a significant downregulation in OGG1 was observed in tumor tissue. Interestingly, when taking into account the tumor stage, patients with more advanced grades (III and IV showed a significant repression for APE1, OGG1 and PARP-1. XRCC1 expression levels were significantly enhanced in tumor samples and were correlated with all clinical and histopathological data. Concerning the polymorphism T2197G, GG genotype carriers exhibited a significantly reduced expression of genes of the BER repair system (APE1, XRCC1 and PARP1. In summary, our data show that patients with colorectal cancer present expression changes in several BER genes, suggesting a role for APE1, XRCC1, PARP1 and OGG1 and APE1 polymorphism in colorectal carcinogenesis.

  7. Complementary genetic screens identify the E3 ubiquitin ligase CBLC, as a modifier of PARP inhibitor sensitivity

    Czech Academy of Sciences Publication Activity Database

    Frankum, J.; Moudrý, P.; Brough, R.; Hodný, Zdeněk; Ashworth, A.; Bartek, Jiří; Lord, C.J.

    2015-01-01

    Roč. 6, č. 13 (2015), s. 10746-10758 ISSN 1949-2553 R&D Projects: GA ČR GA13-17555S EU Projects: European Commission HEALTH-F2-2010-259893 Grant - others:Lundbeck Foundation(DK) R93-A8990; Danish Council for Independent Research(DK) DFF-1331-00262 Institutional support: RVO:68378050 Keywords : DNA damage response * ubiquitin-proteasome system * RNA interference screens * PARP inhibitors * CBLC Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.008, year: 2015

  8. Long non-coding RNA H19 suppresses retinoblastoma progression via counteracting miR-17-92 cluster.

    Science.gov (United States)

    Zhang, Aihui; Shang, Weiwei; Nie, Qiaoli; Li, Ting; Li, Suhui

    2018-04-01

    Long non-coding RNAs (lncRNAs) are frequently dysregulated and play important roles in many cancers. lncRNA H19 is one of the earliest discovered lncRNAs which has diverse roles in different cancers. However, the expression, roles, and action mechanisms of H19 in retinoblastoma are still largely unknown. In this study, we found that H19 is downregulated in retinoblastoma tissues and cell lines. Gain-of-function and loss-of-function assays showed that H19 inhibits retinoblastoma cell proliferation, induces retinoblastoma cell cycle arrest and cell apoptosis. Mechanistically, we identified seven miR-17-92 cluster binding sites on H19, and found that H19 directly bound to miR-17-92 cluster via these seven binding sites. Through binding to miR-17-92 cluster, H19 relieves the suppressing roles of miR-17-92 cluster on p21. Furthermore, H19 represses STAT3 activation induced by miR-17-92 cluster. Hence, our results revealed that H19 upregulates p21 expression, inhibits STAT3 phosphorylation, and downregulates the expression of STAT3 target genes BCL2, BCL2L1, and BIRC5. In addition, functional assays demonstrated that the mutation of miR-17-92 cluster binding sites on H19 abolished the proliferation inhibiting, cell cycle arrest and cell apoptosis inducing roles of H19 in retinoblastoma. In conclusion, our data suggested that H19 inhibits retinoblastoma progression via counteracting the roles of miR-17-92 cluster, and implied that enhancing the action of H19 may be a promising therapeutic strategy for retinoblastoma. © 2017 Wiley Periodicals, Inc.

  9. Minocycline attenuates streptomycin-induced cochlear hair cell death by inhibiting protein nitration and poly (ADP-ribose) polymerase activation.

    Science.gov (United States)

    Wang, Ping; Li, Haonan; Yu, Shuyuan; Jin, Peng; Hassan, Abdurahman; Du, Bo

    2017-08-24

    This study aimed to elucidate the protective effect of minocycline against streptomycin-induced damage of cochlear hair cells and its mechanism. Cochlear membranes were isolated from newborn Wistar rats and randomly divided into control, 500μmol/L streptomycin, 100μmol/L minocycline, and streptomycin and minocycline treatment groups. Hair cell survival was analyzed by detecting the expression of 3-nitrotyrosine (3-NT) in cochlear hair cells by immunofluorescence and an enzyme-linked immunosorbent assay. Expression of 3-NT and inducible nitric oxide synthase (iNOS), and poly (ADP-Ribose) polymerase (PARP) and caspase-3 activation were evaluated by western blotting. The results demonstrated hair cell loss at 24h after streptomycin treatment. No change was found in supporting cells of the cochleae. Minocycline pretreatment improved hair cell survival and significantly reduced the expression of iNOS and 3-NT in cochlear tissues compared with the streptomycin treatment group. PARP and caspase-3 activation was increased in the streptomycin treatment group compared with the control group, and pretreatment with minocycline decreased cleaved PARP and activated caspase-3 expression. Minocycline protected cochlear hair cells from injury caused by streptomycin in vitro. The mechanism underlying the protective effect may be associated with the inhibition of excessive formation of nitric oxide, reduction of the nitration stress reaction, and inhibition of PARP and caspase-3 activation in cochlear hair cells. Combined minocycline therapy can be applied to patients requiring streptomycin treatment. Copyright © 2017. Published by Elsevier B.V.

  10. Molecular docking and 3D-QSAR studies on inhibitors of DNA damage signaling enzyme human PARP-1.

    Science.gov (United States)

    Fatima, Sabiha; Bathini, Raju; Sivan, Sree Kanth; Manga, Vijjulatha

    2012-08-01

    Poly (ADP-ribose) polymerase-1 (PARP-1) operates in a DNA damage signaling network. Molecular docking and three dimensional-quantitative structure activity relationship (3D-QSAR) studies were performed on human PARP-1 inhibitors. Docked conformation obtained for each molecule was used as such for 3D-QSAR analysis. Molecules were divided into a training set and a test set randomly in four different ways, partial least square analysis was performed to obtain QSAR models using the comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). Derived models showed good statistical reliability that is evident from their r², q²(loo) and r²(pred) values. To obtain a consensus for predictive ability from all the models, average regression coefficient r²(avg) was calculated. CoMFA and CoMSIA models showed a value of 0.930 and 0.936, respectively. Information obtained from the best 3D-QSAR model was applied for optimization of lead molecule and design of novel potential inhibitors.

  11. Distinct spatio temporal patterns and PARP dependence of XRCC1 recruitment to single-strand break and base excision repair

    International Nuclear Information System (INIS)

    Campalans, Anna; Kortulewski, Thierry; Amouroux, Rachel; Radicella, J. Pablo; Menoni, Herve; Vermeulen, Wim

    2013-01-01

    Single-strand break repair (SSBR) and base excision repair (BER) of modified bases and abasic sites share several players. Among them is XRCC1, an essential scaffold protein with no enzymatic activity, required for the coordination of both pathways. XRCC1 is recruited to SSBR by PARP-1, responsible for the initial recognition of the break. The recruitment of XRCC1 to BER is still poorly understood. Here we show by using both local and global induction of oxidative DNA base damage that XRCC1 participation in BER complexes can be distinguished from that in SSBR by several criteria. We show first that XRCC1 recruitment to BER is independent of PARP. Second, unlike SSBR complexes that are assembled within minutes after global damage induction, XRCC1 is detected later in BER patches, with kinetics consistent with the repair of oxidized bases. Third, while XRCC1-containing foci associated with SSBR are formed both in eu- and heterochromatin domains, BER complexes are assembled in patches that are essentially excluded from heterochromatin and where the oxidized bases are detected. (authors)

  12. vPARP Adjusts MVP Expression in Drug-resistant Cell Lines in Conjunction with MDR Proteins.

    Science.gov (United States)

    Wojtowicz, Karolina; Januchowski, Radoslaw; Nowicki, Michal; Zabel, Maciej

    2017-06-01

    The definition of vault (ribonucleoprotein particles) function remains highly complex. Vaults may cooperate with multidrug resistance (MDR) proteins, supporting their role in drug resistance. This topic is the main theme of this publication. The cell viability was determined by an MTT assay. The protein expression was detected by western blot analysis. The proteins were knocked-down using siRNA. No major vault protein (MVP) in the LoVo/Dx and W1PR cell lines after tunicamycin treatment was shown. In W1PR cells with knocked-down MVP, a statistically significant decrease in cell viability was noted. In LoVo/Dx, W1TR and A2780TR cells were vault poly-ADP-ribose polymerase (vPARP) was knockdown, a decrease in cell viability was shown. Also, MVP silencing induced an increase in glycoprotein P (Pgp) expression in LoVo/Dx cells. MVP is important for the drug resistance of cancer cells, but it probably requires the presence of vPARP for full activation. Some correlations between MDR proteins and vaults exist. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  13. Differential transactivation by orphan nuclear receptor NOR1 and its fusion gene product EWS/NOR1: possible involvement of poly(ADP-ribose) polymerase I, PARP-1.

    Science.gov (United States)

    Ohkura, Naganari; Nagamura, Yuko; Tsukada, Toshihiko

    2008-10-15

    In extraskeletal myxoid chondrosarcoma, a chromosomal translocation creates a gene fusion between EWS and an orphan nuclear receptor, NOR1. The resulting fusion protein EWS/NOR1 has been believed to lead to malignant transformation by functioning as a transactivator for NOR1-target genes. By comparing the gene expression profiles of NOR1- and EWS/NOR1-overexpressing cells, we found that they largely shared up-regulated genes, but no significant correlation was observed with respect to the transactivation levels of each gene. In addition, the proteins associated with NOR1 and EWS/NOR1 were mostly the same in these cells. The results suggest that these proteins differentially transactivate overlapping target genes through a similar transcriptional machinery. To clarify the mechanisms underlying the transcriptional divergence between NOR1 and EWS/NOR1, we searched for alternatively associated proteins, and identified poly(ADP-ribose) polymerase I (PARP-1) as an NOR1-specific binding protein. Consistent with its binding properties, PARP-1 acted as a transcriptional repressor of NOR1, but not EWS/NOR1, in a luciferase reporter assay employing PARP-1(-/-) fibroblasts. Interestingly, suppressive activity of PARP-1 was observed in a DNA response element-specific manner, and in a subtype-specific manner toward the NR4A family (Nur77, Nurr1, and NOR1), suggesting that PARP-1 plays a role in the diversity of transcriptional regulation mediated by the NR4A family in normal cells. Altogether, our findings suggest that NOR1 and EWS/NOR1 regulate overlapping target genes differently by utilizing associated proteins, including PARP-1; and that EWS/NOR1 may acquire oncogenic activities by avoiding (or gaining) transcription factor-specific modulation by the associated proteins. (c) 2008 Wiley-Liss, Inc.

  14. Buspirone Counteracts MK-801-Induced Schizophrenia-Like Phenotypes through Dopamine D3 Receptor Blockade

    Science.gov (United States)

    Torrisi, Sebastiano Alfio; Salomone, Salvatore; Geraci, Federica; Caraci, Filippo; Bucolo, Claudio; Drago, Filippo; Leggio, Gian Marco

    2017-01-01

    Background: Several efforts have been made to develop effective antipsychotic drugs. Currently, available antipsychotics are effective on positive symptoms, less on negative symptoms, but not on cognitive impairment, a clinically relevant dimension of schizophrenia. Drug repurposing offers great advantages over the long-lasting, risky and expensive, de novo drug discovery strategy. To our knowledge, the possible antipsychotic properties of buspirone, an azapirone anxiolytic drug marketed in 1986 as serotonin 5-HT1A receptor (5-HT1AR) partial agonist, have not been extensively investigated despite its intriguing pharmacodynamic profile, which includes dopamine D3 (D3R) and D4 receptor (D4R) antagonist activity. Multiple lines of evidence point to D3R as a valid therapeutic target for the treatment of several neuropsychiatric disorders including schizophrenia. In the present study, we tested the hypothesis that buspirone, behaving as dopamine D3R antagonist, may have antipsychotic-like activity. Materials and Methods: Effects of acute administration of buspirone was assessed on a wide-range of schizophrenia-relevant abnormalities induced by a single administration of the non-competitive NMDAR antagonist MK-801, in both wild-type mice (WT) and D3R-null mutant mice (D3R-/-). Results: Buspirone (3 mg⋅kg-1, i.p.) was devoid of cataleptogenic activity in itself, but resulted effective in counteracting disruption of prepulse inhibition (PPI), hyperlocomotion and deficit of temporal order recognition memory (TOR) induced by MK-801 (0.1 mg⋅kg-1, i.p.) in WT mice. Conversely, in D3R-/- mice, buspirone was ineffective in preventing MK-801-induced TOR deficit and it was only partially effective in blocking MK-801-stimulated hyperlocomotion. Conclusion: Taken together, these results indicate, for the first time, that buspirone, might be a potential therapeutic medication for the treatment of schizophrenia. In particular, buspirone, through its D3R antagonist activity, may be

  15. A Case for Relational Leadership and an Ethics of Care for Counteracting Bullying at Schools

    Science.gov (United States)

    Smit, Brigitte; Scherman, Vanessa

    2016-01-01

    This paper attends to a theoretical exposition of relational leadership and ethics care as complementary approaches to educational leadership in counteracting bullying at schools. Schools constitute complex systems of activities, processes and dynamics. More specifically, a social system in schools is a web of interactions between the various…

  16. Dialogue and Exchange of Information about Grade Inflation Can Counteract Its Effects

    Science.gov (United States)

    Barriga, Alvaro Q.; Cooper, Eric K.; Gawelek, Mary Ann; Butela, Kristin; Johnson, Elizabeth

    2008-01-01

    This investigation documents an intervention that successfully counteracted a grade inflation trend at a small, Catholic, liberal arts university in the eastern United States. The intervention produced a significant drop in grades awarded by full-time faculty, but not by adjunct faculty who were not yet included in the intervention. Institutional…

  17. Maldistribution in air-water heat pump evaporators. Part 2: Economic analysis of counteracting technologies

    DEFF Research Database (Denmark)

    Mader, Gunda; Palm, Björn; Elmegaard, Brian

    2015-01-01

    maldistribution,high electricity prices, and colder climate. Investment in the individual superheat controltechnology, however, can be quickly amortized in many scenarios. For the warmer climatezone with a small number of operating hours counteracting of maldistribution does notpay off under the used economic...... assumptions.© 2014 Elsevier Ltd and IIR. All rights reserved....

  18. Alanine Counteracts the Destabilizing Effect that Urea has on RNase-A.

    Science.gov (United States)

    Chowhan, Rimpy K; Ali, Fasil; Bhat, Mohd Y; Rahman, Safikur; Singh, Laishram R; Ahmad, Faizan; Dar, Tanveer A

    2016-01-01

    It is generally believed that organisms use and accumulate methylamine osmolytes to prevent urea's damaging effect on protein stability and activity. However, urea-rich cells not only accumulate methylamines but also many other methylated and non-methylated compounds as well. But, so far it is not known whether osmolytes that are not accumulated in urea-rich cells could also confer urea-counteracting properties. We investigated the behavior of a non-methylamine osmolyte, alanine for its counteracting effect against urea denaturation of a model protein, ribonuclease A (RNase-A). We have measured structure and thermodynamic parameters (Tm, ΔHm, and ΔGD°) of RNase-A in the presence of alanine, urea and their combination. The results were also compared with the ability of glycine (osmolyte lacking one methyl group when compared with alanine) to counter urea's effect on protein stability. We observed that alanine but not glycine counteracts urea's harmful effect on RNase-A stability. The results indicated that alanine (in addition to methylamine osmolytes) may serve as an alternate urea-counteractant. Since glycine fails to protect RNase-A from urea's destabilizing effect, it seems that methylation to glycine might have some evolutionary significance to protect proteins against harmful effects of urea.

  19. Counteracting media’s thin body ideal in adolescent girls: informing is more effective than warning.

    NARCIS (Netherlands)

    Veldhuis, J.; Konijn, E.A.; Seidell, J.C.

    2014-01-01

    The present study investigated whether information or warnings about depictions of the thin-body ideal in mass media are effective in counteracting media-induced negative body perceptions of adolescent girls. Based on counter-advertising and reactance theories, our hypotheses were tested in a 3

  20. The condition of counteraction to administrative corruption offenses in state authorities and local government

    Directory of Open Access Journals (Sweden)

    О. В. Клок

    2014-12-01

    Full Text Available Article discusses questions dedicated to the analysis of the condition of counteraction to administrative corruption offenses in Ukraine. The statistical information on the dynamics, structure, specific gravity, cost and latency of the administrative corruption is researched. The most effective measures against corrupt practices at the state and municipal service are drawn.

  1. miR-520 promotes DNA-damage-induced trophoblast cell apoptosis by targeting PARP1 in recurrent spontaneous abortion (RSA).

    Science.gov (United States)

    Dong, Xiujuan; Yang, Long; Wang, Hui

    2017-04-01

    The establishment and maintenance of successful pregnancy mainly depends on trophoblast cells. Their dysfunction has been implicated in recurrent spontaneous abortion (RSA), a major complication of pregnancy. However, the underlying mechanisms of trophoblasts dysfunction remain unclear. DNA-damage-induced cell apoptosis has been reported to play a vital role in cell death. In this study, we identified a novel microRNA (miR-520) in RSA progression via regulating trophoblast cell apoptosis. Microarray analysis showed that miR-520 was highly expressed in villus of RSA patients. By using flow cytometry analysis, we observed miR-520 expression was correlated with human trophoblast cell apoptosis in vitro, along with decreased poly (ADP-ribose) polymerase-1 (PARP1) expression. With the analysis of clinic samples, we observed that miR-520 level was negatively correlated with PARP1 level in RSA villus. In addition, overexpression of PARP1 restored the miR-520-induced trophoblast cell apoptosis in vitro. The status of chromosome in trophoblast implied that miR-520-promoted DNA-damage-induced cell apoptosis to regulate RSA progression. These results indicated that the level of miR-520 might associate with RSA by prompting trophoblast cell apoptosis via PARP1 dependent DNA-damage pathway.

  2. Extent of radiosensitization by the PARP inhibitor olaparib depends on its dose, the radiation dose and the integrity of the homologous recombination pathway of tumor cells

    NARCIS (Netherlands)

    Verhagen, Caroline V. M.; de Haan, Rosemarie; Hageman, Floor; Oostendorp, Tim P. D.; Carli, Annalisa L. E.; O'Connor, Mark J.; Jonkers, Jos; Verheij, Marcel; van den Brekel, Michiel W.; Vens, Conchita

    2015-01-01

    The PARP inhibitor olaparib is currently tested in clinical phase 1 trials to define safe dose levels in combination with RT. However, certain clinically relevant insights are still lacking. Here we test, while comparing to single agent activity, the olaparib dose and genetic background dependence

  3. Extent of radiosensitization by the PARP inhibitor olaparib depends on its dose, the radiation dose and the integrity of the homologous recombination pathway of tumor cells

    NARCIS (Netherlands)

    Verhagen, C.V.M.; Haan, R. den; Hageman, F.; Oostendorp, T.P.; Carli, A.L.; O'Connor, M.J.; Jonkers, J.; Verheij, M.; Brekel, M.W. van den; Vens, C.

    2015-01-01

    BACKGROUND AND PURPOSE: The PARP inhibitor olaparib is currently tested in clinical phase 1 trials to define safe dose levels in combination with RT. However, certain clinically relevant insights are still lacking. Here we test, while comparing to single agent activity, the olaparib dose and genetic

  4. Extent of radiosensitization by the PARP inhibitor olaparib depends on its dose, the radiation dose and the integrity of the homologous recombination pathway of tumor cells

    NARCIS (Netherlands)

    Verhagen, C.V.M.; de Haan, R.; Hageman, F.; Oostendorp, T.P.D.; Carli, A.L.E.; O'Connor, M.J.; Jonkers, J.; Verheij, M.; van den Brekel, M.W.; Vens, C.

    2015-01-01

    Background and purpose The PARP inhibitor olaparib is currently tested in clinical phase 1 trials to define safe dose levels in combination with RT. However, certain clinically relevant insights are still lacking. Here we test, while comparing to single agent activity, the olaparib dose and genetic

  5. Effect of Sterols Isolated from Myrtillocactus geometrizans on Growth Inhibition of Colon and Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Mario Augusto Bolaños-Carrillo

    2015-01-01

    Full Text Available Objective. To explore the effect of peniocerol and macdougallin on HCT-15 and MCF-7 cells proliferation, cell cycle, apoptosis, and PARP cleavage. Methods. HCT-15 and MCF-7 cells were treated with various concentrations of peniocerol and macdougallin (10–80 μM during 24 or 48 h. Crystal Violet Assay was used to evaluate the inhibition effect. Cell cycle regulation was examined by a propidium iodide method. Cell apoptosis was detected through both Annexin–V FLUOS/PI double-labeled cytometry assays and Western blot was applied to assess PARP cleavage. Results. Peniocerol and macdougallin induced growth inhibition and apoptosis in vitro in a time- and dose-dependent manner. Moreover, peniocerol and macdougallin induced arrest of cell cycle-dependent manner and increased the proportion of cells in G0/G1 phase. PARP cleavage in HCT-15 and MCF-7 cells was induced by treatment with peniocerol and macdougallin after 36 hours. Conclusions. Our results showed that the mechanism of cytotoxicity displayed by peniocerol and macdougallin is related to cell cycle arrest and apoptosis in both cell lines. This is a significant observation because it helps to understand the way some oxysterols isolated from Myrtillocactus geometrizans develop their biological activities against cancer cells.

  6. Improvement of Antitumor Therapies Based on Vaccines and Immune-Checkpoint Inhibitors by Counteracting Tumor-Immunostimulation

    Directory of Open Access Journals (Sweden)

    Paula Chiarella

    2018-01-01

    Full Text Available Immune-checkpoint inhibitors and antitumor vaccines may produce both tumor-inhibitory and tumor-stimulatory effects on growing tumors depending on the stage of tumor growth at which treatment is initiated. These paradoxical results are not necessarily incompatible with current tumor immunology but they might better be explained assuming the involvement of the phenomenon of tumor immunostimulation. This phenomenon was originally postulated on the basis that the immune response (IR evoked in Winn tests by strong chemical murine tumors was not linear but biphasic, with strong IR producing inhibition and weak IR inducing stimulation of tumor growth. Herein, we extended those former observations to weak spontaneous murine tumors growing in pre-immunized, immune-competent and immune-depressed mice. Furthermore, we demonstrated that the interaction of specifical T cells and target tumor cells at low stimulatory ratios enhanced the production of chemokines aimed to recruit macrophages at the tumor site, which, upon activation of toll-like receptor 4 and p38 signaling pathways, would recruit and activate more macrophages and other inflammatory cells which would produce growth-stimulating signals leading to an accelerated tumor growth. On this basis, the paradoxical effects achieved by immunological therapies on growing tumors could be explained depending upon where the therapy-induced IR stands on the biphasic IR curve at each stage of tumor growth. At stages where tumor growth was enhanced (medium and large-sized tumors, counteraction of the tumor-immunostimulatory effect with anti-inflammatory strategies or, more efficiently, with selective inhibitors of p38 signaling pathways enabled the otherwise tumor-promoting immunological strategies to produce significant inhibition of tumor growth.

  7. Glutamate Counteracts Dopamine/PKA Signaling via Dephosphorylation of DARPP-32 Ser-97 and Alteration of Its Cytonuclear Distribution.

    Science.gov (United States)

    Nishi, Akinori; Matamales, Miriam; Musante, Veronica; Valjent, Emmanuel; Kuroiwa, Mahomi; Kitahara, Yosuke; Rebholz, Heike; Greengard, Paul; Girault, Jean-Antoine; Nairn, Angus C

    2017-01-27

    The interaction of glutamate and dopamine in the striatum is heavily dependent on signaling pathways that converge on the regulatory protein DARPP-32. The efficacy of dopamine/D1 receptor/PKA signaling is regulated by DARPP-32 phosphorylated at Thr-34 (the PKA site), a process that inhibits protein phosphatase 1 (PP1) and potentiates PKA action. Activation of dopamine/D1 receptor/PKA signaling also leads to dephosphorylation of DARPP-32 at Ser-97 (the CK2 site), leading to localization of phospho-Thr-34 DARPP-32 in the nucleus where it also inhibits PP1. In this study the role of glutamate in the regulation of DARPP-32 phosphorylation at four major sites was further investigated. Experiments using striatal slices revealed that glutamate decreased the phosphorylation states of DARPP-32 at Ser-97 as well as Thr-34, Thr-75, and Ser-130 by activating NMDA or AMPA receptors in both direct and indirect pathway striatal neurons. The effect of glutamate in decreasing Ser-97 phosphorylation was mediated by activation of PP2A. In vitro phosphatase assays indicated that the PP2A/PR72 heterotrimer complex was likely responsible for glutamate/Ca 2+ -regulated dephosphorylation of DARPP-32 at Ser-97. As a consequence of Ser-97 dephosphorylation, glutamate induced the nuclear localization in cultured striatal neurons of dephospho-Thr-34/dephospho-Ser-97 DARPP-32. It also reduced PKA-dependent DARPP-32 signaling in slices and in vivo Taken together, the results suggest that by inducing dephosphorylation of DARPP-32 at Ser-97 and altering its cytonuclear distribution, glutamate may counteract dopamine/D1 receptor/PKA signaling at multiple cellular levels. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. Glutamate Counteracts Dopamine/PKA Signaling via Dephosphorylation of DARPP-32 Ser-97 and Alteration of Its Cytonuclear Distribution*

    Science.gov (United States)

    Nishi, Akinori; Matamales, Miriam; Musante, Veronica; Valjent, Emmanuel; Kuroiwa, Mahomi; Kitahara, Yosuke; Rebholz, Heike; Greengard, Paul; Girault, Jean-Antoine; Nairn, Angus C.

    2017-01-01

    The interaction of glutamate and dopamine in the striatum is heavily dependent on signaling pathways that converge on the regulatory protein DARPP-32. The efficacy of dopamine/D1 receptor/PKA signaling is regulated by DARPP-32 phosphorylated at Thr-34 (the PKA site), a process that inhibits protein phosphatase 1 (PP1) and potentiates PKA action. Activation of dopamine/D1 receptor/PKA signaling also leads to dephosphorylation of DARPP-32 at Ser-97 (the CK2 site), leading to localization of phospho-Thr-34 DARPP-32 in the nucleus where it also inhibits PP1. In this study the role of glutamate in the regulation of DARPP-32 phosphorylation at four major sites was further investigated. Experiments using striatal slices revealed that glutamate decreased the phosphorylation states of DARPP-32 at Ser-97 as well as Thr-34, Thr-75, and Ser-130 by activating NMDA or AMPA receptors in both direct and indirect pathway striatal neurons. The effect of glutamate in decreasing Ser-97 phosphorylation was mediated by activation of PP2A. In vitro phosphatase assays indicated that the PP2A/PR72 heterotrimer complex was likely responsible for glutamate/Ca2+-regulated dephosphorylation of DARPP-32 at Ser-97. As a consequence of Ser-97 dephosphorylation, glutamate induced the nuclear localization in cultured striatal neurons of dephospho-Thr-34/dephospho-Ser-97 DARPP-32. It also reduced PKA-dependent DARPP-32 signaling in slices and in vivo. Taken together, the results suggest that by inducing dephosphorylation of DARPP-32 at Ser-97 and altering its cytonuclear distribution, glutamate may counteract dopamine/D1 receptor/PKA signaling at multiple cellular levels. PMID:27998980

  9. Neer Award 2016: reduced muscle degeneration and decreased fatty infiltration after rotator cuff tear in a poly(ADP-ribose) polymerase 1 (PARP-1) knock-out mouse model.

    Science.gov (United States)

    Kuenzler, Michael B; Nuss, Katja; Karol, Agnieszka; Schär, Michael O; Hottiger, Michael; Raniga, Sumit; Kenkel, David; von Rechenberg, Brigitte; Zumstein, Matthias A

    2017-05-01

    Disturbed muscular architecture, atrophy, and fatty infiltration remain irreversible in chronic rotator cuff tears even after repair. Poly (adenosine 5'-diphosphate-ribose) polymerase 1 (PARP-1) is a key regulator of inflammation, apoptosis, muscle atrophy, muscle regeneration, and adipocyte development. We hypothesized that the absence of PARP-1 would lead to a reduction in damage to the muscle subsequent to combined tenotomy and neurectomy in a PARP-1 knockout (KO) mouse model. PARP-1 KO and wild-type C57BL/6 (WT group) mice were analyzed at 1, 6, and 12 weeks (total n = 84). In all mice, the supraspinatus and infraspinatus muscles of the left shoulder were detached and denervated. Macroscopic analysis, magnetic resonance imaging, gene expression analysis, immunohistochemistry, and histology were used to assess the differences in PARP-1 KO and WT mice. The muscles in the PARP-1 KO group had significantly less retraction, atrophy, and fatty infiltration after 12 weeks than in the WT group. Gene expression of inflammatory, apoptotic, adipogenic, and muscular atrophy genes was significantly decreased in PARP-1 KO mice in the first 6 weeks. Absence of PARP-1 leads to a reduction in muscular architectural damage, early inflammation, apoptosis, atrophy, and fatty infiltration after combined tenotomy and neurectomy of the rotator cuff muscle. Although the macroscopic reaction to injury is similar in the first 6 weeks, the ability of the muscles to regenerate was much greater in the PARP-1 KO group, leading to a near-normalization of the muscle after 12 weeks. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  10. Nature gives us strength: exposure to nature counteracts ego-depletion.

    Science.gov (United States)

    Chow, Jason T; Lau, Shun

    2015-01-01

    Previous research rarely investigated the role of physical environment in counteracting ego-depletion. In the present research, we hypothesized that exposure to natural environment counteracts ego-depletion. Three experiments were conducted to test this hypothesis. In Experiment 1, initially depleted participants who viewed pictures of nature scenes showed greater persistence on a subsequent anagram task than those who were given a rest period. Experiment 2 expanded upon this finding by showing that natural environment enhanced logical reasoning performance after ego-depleting task. Experiment 3 adopted a two- (depletion vs. no-depletion) -by-two (nature exposure vs. urban exposure) factorial design. We found that nature exposure moderated the effect of depletion on anagram task performance. Taken together, the present studies offer a viable and novel strategy to mitigate the negative impacts of ego-depletion.

  11. Alpha-Tocopherol Counteracts the Cytotoxicity Induced by Ochratoxin A in Primary Porcine Fibroblasts

    DEFF Research Database (Denmark)

    Fusi, Elenora; Rebucci, Raffaella; Pecorini, Chiara

    2010-01-01

    The aims of the current study were to determine the half-lethal concentration of ochratoxin A (OTA) as well as the levels of lactate dehydrogenase release and DNA fragmentation induced by OTA in primary porcine fibroblasts, and to examine the role of α-tocopherol in counteracting its toxicity....... Cells showed a dose-, time- and origin-dependent (ear vs. embryo) sensitivity to ochratoxin A. Pre-incubation for 3 h with 1 nM α-tocopherol significantly (P tocopherol...

  12. Counteracting fatigue in multiple sclerosis with right parietal anodal transcranial direct current stimulation

    OpenAIRE

    Katrin Hanken; Katrin Hanken; Mona Bosse; Kim Möhrke; Paul Eling; Andreas Kastrup; Andrea Antal; Helmut Hildebrandt; Helmut Hildebrandt

    2016-01-01

    Background: Fatigue in multiple sclerosis (MS) patients appears to correlate with vigilance decrement as reflected in an increase in reaction time and errors with prolonged time-on-task. Objectives: The aim of this study was to investigate whether anodal transcranial direct current stimulation (tDCS) over the right parietal or frontal cortex counteracts fatigue-associated vigilance decrement and subjective fatigue. Methods: In study I, a randomized double-blind placebo-controlled study, anoda...

  13. Counteracting Fatigue in Multiple Sclerosis with Right Parietal Anodal Transcranial Direct Current Stimulation

    OpenAIRE

    Hanken, Katrin; Bosse, Mona; M?hrke, Kim; Eling, Paul; Kastrup, Andreas; Antal, Andrea; Hildebrandt, Helmut

    2016-01-01

    BACKGROUND: Fatigue in multiple sclerosis (MS) patients appears to correlate with vigilance decrement as reflected in an increase in reaction time (RT) and errors with prolonged time-on-task. OBJECTIVES: The aim of this study was to investigate whether anodal transcranial direct current stimulation (tDCS) over the right parietal or frontal cortex counteracts fatigue-associated vigilance decrement and subjective fatigue. METHODS: In study I, a randomized double-blind placebo-controll...

  14. Neurosteroid 3α-androstanediol efficiently counteracts paclitaxel-induced peripheral neuropathy and painful symptoms.

    Directory of Open Access Journals (Sweden)

    Laurence Meyer

    Full Text Available Painful peripheral neuropathy belongs to major side-effects limiting cancer chemotherapy. Paclitaxel, widely used to treat several cancers, induces neurological symptoms including burning pain, allodynia, hyperalgesia and numbness. Therefore, identification of drugs that may effectively counteract paclitaxel-induced neuropathic symptoms is crucial. Here, we combined histopathological, neurochemical, behavioral and electrophysiological methods to investigate the natural neurosteroid 3α-androstanediol (3α-DIOL ability to counteract paclitaxel-evoked peripheral nerve tissue damages and neurological symptoms. Prophylactic or corrective 3α-DIOL treatment (4 mg/kg/2 days prevented or suppressed PAC-evoked heat-thermal hyperalgesia, cold-allodynia and mechanical allodynia/hyperalgesia, by reversing to normal, decreased thermal and mechanical pain thresholds of PAC-treated rats. Electrophysiological studies demonstrated that 3α-DIOL restored control values of nerve conduction velocity and action potential peak amplitude significantly altered by PAC-treatment. 3α-DIOL also repaired PAC-induced nerve damages by restoring normal neurofilament-200 level in peripheral axons and control amount of 2',3'-cyclic-nucleotide-3'-phosphodiesterase in myelin sheaths. Decreased density of intraepidermal nerve fibers evoked by PAC-therapy was also counteracted by 3α-DIOL treatment. More importantly, 3α-DIOL beneficial effects were not sedation-dependent but resulted from its neuroprotective ability, nerve tissue repairing capacity and long-term analgesic action. Altogether, our results showing that 3α-DIOL efficiently counteracted PAC-evoked painful symptoms, also offer interesting possibilities to develop neurosteroid-based strategies against chemotherapy-induced peripheral neuropathy. This article shows that the prophylactic or corrective treatment with 3α-androstanediol prevents or suppresses PAC-evoked painful symptoms and peripheral nerve dysfunctions in

  15. Counteracting Animal Homelessness and Providing Care for Stray Animals as a Task of a Commune

    OpenAIRE

    Szalewska, Małgorzata

    2017-01-01

    The analysis of Polish binding law acts allows one to assume that, on normative level, the obligation of public administration to provide care for stray animals is deeply embedded. Both the Animal Protection Act, as well as the Act on Maintaining Cleanliness, indicate the tasks of a commune in the scope of providing care for stray animals, catching homeless animals and counteracting their homelessness. Simultaneously, the analysis of jurisdiction, and inquiries as well as considerations emerg...

  16. Strategies used to counteract bullying in schools : a comparative study / Wendy Batterbee

    OpenAIRE

    Batterbee, Wendy Ann

    2007-01-01

    This is an in-depth comparative study of the strategies used to counteract bullying at schools. It provides an international perspective on such strategies: Studies in South African schools are used to provide an African perspective: Australian research is used to provide an Oceanian perspective: Japanese research to provide an Asian perspective; and research conducted in England is used to provide an European perspective on bullying at schools. The extent and nature of bullying in schools...

  17. Physical activity counteracts tumor cell growth in colon carcinoma C26-injected muscles: an interim report

    Directory of Open Access Journals (Sweden)

    Charlotte Hiroux

    2016-06-01

    Full Text Available Skeletal muscle tissue is a rare site of tumor metastasis but is the main target of the degenerative processes occurring in cancer-associated cachexia syndrome. Beneficial effects of physical activity in counteracting cancer-related muscle wasting have been described in the last decades. Recently it has been shown that, in tumor xeno-transplanted mouse models, physical activity is able to directly affect tumor growth by modulating inflammatory responses in the tumor mass microenvironment. Here, we investigated the effect of physical activity on tumor cell growth in colon carcinoma C26 cells injected tibialis anterior muscles of BALB/c mice. Histological analyses revealed that 4 days of voluntary wheel running significantly counteracts tumor cell growth in C26-injected muscles compared to the non-injected sedentary controls. Since striated skeletal muscle tissue is the site of voluntary contraction, our results confirm that physical activity can also directly counteract tumor cell growth in a metabolically active tissue that is usually not a target for metastasis.

  18. Gradient pre-emphasis to counteract first-order concomitant fields on asymmetric MRI gradient systems.

    Science.gov (United States)

    Tao, Shengzhen; Weavers, Paul T; Trzasko, Joshua D; Shu, Yunhong; Huston, John; Lee, Seung-Kyun; Frigo, Louis M; Bernstein, Matt A

    2017-06-01

    To develop a gradient pre-emphasis scheme that prospectively counteracts the effects of the first-order concomitant fields for any arbitrary gradient waveform played on asymmetric gradient systems, and to demonstrate the effectiveness of this approach using a real-time implementation on a compact gradient system. After reviewing the first-order concomitant fields that are present on asymmetric gradients, we developed a generalized gradient pre-emphasis model assuming arbitrary gradient waveforms to counteract their effects. A numerically straightforward, easily implemented approximate solution to this pre-emphasis problem was derived that was compatible with the current hardware infrastructure of conventional MRI scanners for eddy current compensation. The proposed method was implemented on the gradient driver subsystem, and its real-time use was tested using a series of phantom and in vivo data acquired from two-dimensional Cartesian phase-difference, echo-planar imaging, and spiral acquisitions. The phantom and in vivo results demonstrated that unless accounted for, first-order concomitant fields introduce considerable phase estimation error into the measured data and result in images with spatially dependent blurring/distortion. The resulting artifacts were effectively prevented using the proposed gradient pre-emphasis. We have developed an efficient and effective gradient pre-emphasis framework to counteract the effects of first-order concomitant fields of asymmetric gradient systems. Magn Reson Med 77:2250-2262, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  19. Neural signal for counteracting pre-action bias in the centromedian thalamic nucleus

    Directory of Open Access Journals (Sweden)

    Takafumi eMinamimoto

    2014-01-01

    Full Text Available Most of our daily actions are selected and executed involuntarily under familiar situations by the guidance of internal drives, such as motivation. The behavioral tendency or biasing towards one over others reflects the action-selection process in advance of action execution (i.e., pre-action bias. Facing unexpected situations, however, pre-action bias should be withdrawn and replaced by an alternative that is suitable for the situation (i.e., counteracting bias. To understand the neural mechanism for the counteracting process, we studied the neural activity of the thalamic centromedian (CM nucleus in monkeys performing GO-NOGO task with asymmetrical or symmetrical reward conditions. The monkeys reacted to GO signal faster in large-reward condition, indicating behavioral bias toward large reward. In contrast, they responded slowly in small-reward condition, suggesting a conflict between internal drive and external demand. We found that neurons in the CM nucleus exhibited phasic burst discharges after GO and NOGO instructions especially when they were associated with small reward. The small-reward preference was positively correlated with the strength of behavioral bias toward large reward. The small-reward preference disappeared when only NOGO action was requested. The timing of activation predicted the timing of action opposed to bias. These results suggest that CM signals the discrepancy between internal pre-action bias and external demand, and mediates the counteracting process — resetting behavioral bias and leading to execution of opposing action.

  20. Repair of radiation-induced heat-labile sites is independent of DNA-PKcs, XRCC1 or PARP

    Energy Technology Data Exchange (ETDEWEB)

    Stenerl& #246; w, Bo; Karlsson, Karin H.; Radulescu, Irina; Rydberg, Bjorn; Stenerlow, Bo

    2008-04-29

    Ionizing radiation induces a variety of different DNA lesions: in addition to the most critical DNA damage, the DSB, numerous base alterations, SSBs and other modifications of the DNA double-helix are formed. When several non-DSB lesions are clustered within a short distance along DNA, or close to a DSB, they may interfere with the repair of DSBs and affect the measurement of DSB induction and repair. We have previously shown that a substantial fraction of DSBs measured by pulsed-field gel electrophoresis (PFGE) are in fact due to heat-labile sites (HLS) within clustered lesions, thus reflecting an artifact of preparation of genomic DNA at elevated temperature. To further characterize the influence of HLS on DSB induction and repair, four human cell lines (GM5758, GM7166, M059K, U-1810) with apparently normal DSB rejoining were tested for bi-phasic rejoining after gamma irradiation. When heat-released DSBs were excluded from the measurements the fraction of fast rejoining decreased to less than 50% of the total. However, neither the half-times of the fast (t{sub 1/2} = 7-8 min) or slow (t{sub 1/2} = 2.5 h) DSB rejoining were changed significantly. At t=0 the heat-released DSBs accounted for almost 40% of the DSBs, corresponding to 10 extra DSB/cell/Gy in the initial DSB yield. These heat-released DSBs were repaired within 60-90 min in all tested cells, including M059K cells treated with wortmannin or DNA-PKcs defect M059J cells. Furthermore, cells lacking XRCC1 or Poly(ADP-ribose) polymerase-1 (PARP-1) rejoined both total DSBs and heat-released DSBs similar to normal cells. In summary, the presence of heat-labile sites have a substantial impact on DSB induction yields and DSB rejoining rates measured by pulsed-field gel electrophoresis, and HLS repair is independent of DNA-PKcs, XRCC1 and PARP.

  1. Carbon ion beam triggers both caspase-dependent and caspase-independent pathway of apoptosis in HeLa and status of PARP-1 controls intensity of apoptosis.

    Science.gov (United States)

    Ghorai, Atanu; Sarma, Asitikantha; Bhattacharyya, Nitai P; Ghosh, Utpal

    2015-04-01

    High linear energy transfer (LET) carbon ion beam (CIB) is becoming very promising tool for various cancer treatments and is more efficient than conventional low LET gamma or X-rays to kill malignant or radio-resistant cells, although detailed mechanism of cell death is still unknown. Poly (ADP-ribose) polymerase-1 (PARP-1) is a key player in DNA repair and its inhibitors are well-known as radio-sensitizer for low LET radiation. The objective of our study was to find mechanism(s) of induction of apoptosis by CIB and role of PARP-1 in CIB-induced apoptosis. We observed overall higher apoptosis in PARP-1 knocked down HeLa cells (HsiI) compared with negative control H-vector cells after irradiation with CIB (0-4 Gy). CIB activated both intrinsic and extrinsic pathways of apoptosis via caspase-9 and caspase-8 activation respectively, followed by caspase-3 activation, apoptotic body, nucleosomal ladder formation and sub-G1 accumulation. Apoptosis inducing factor translocation into nucleus in H-vector but not in HsiI cells after CIB irradiation contributed caspase-independent apoptosis. Higher p53 expression was observed in HsiI cells compared with H-vector after exposure with CIB. Notably, we observed about 37 % fall of mitochondrial membrane potential, activation of caspase-9 and caspase-3 and mild activation of caspase-8 without any detectable apoptotic body formation in un-irradiated HsiI cells. We conclude that reduction of PARP-1 expression activates apoptotic signals via intrinsic and extrinsic pathways in un-irradiated cells. CIB irradiation further intensified both intrinsic and extrinsic pathways of apoptosis synergistically along with up-regulation of p53 in HsiI cells resulting overall higher apoptosis in HsiI than H-vector.

  2. Comparative analysis of successful practices of corruption counteraction in the sphere of school education in foreign countries

    Directory of Open Access Journals (Sweden)

    Valentina Vladimirovna Tereshkova

    2015-03-01

    Full Text Available Objective to analyze the practice of corruption counteraction in the sphere of school education in foreign countries. Methods comparativelegal method polling content analysis of documents expert evaluation testing of experts with an international technique Questionnaire Profile of Demand. Results the need for the corruption counteraction program is stated in Art. 13.3 of the Federal Law ldquoOn corruption counteractionrdquoand Methodological recommendations of the Russian Ministry of Labor on corruption risks evaluation when implementing functions but no definite measures for corruption counteraction in educational organizations have been formulated. Nevertheless the controlling bodies inquire for information on such measures. As an example wecitean inquiry of Krasnoyarsk Oktyabrskiy region Prosecutorrsquos Office to educational organizations of October 21 2014 no. 86012014 ldquoOn measures for corruption counteraction in the sphere of educationrdquo. Scientific novelty summarizing the experience of corruption counteraction in the sphere of education in foreign countries and the expertsrsquo opinion of the specialist of international organizations allowed to formulate a number of recommendations for the Russian educational establishments. Practical value the experience of corruption counteraction in foreign countries will allow the head of an educational establishment to choose those of the proposed measures which will be efficient in corruption prevention and to elaborate an efficient program for corruption prevention. nbsp

  3. Expression profiles of vault components MVP, TEP1 and vPARP and their correlation to other multidrug resistance proteins in ovarian cancer.

    Science.gov (United States)

    Szaflarski, Witold; Sujka-Kordowska, Patrycja; Pula, Bartosz; Jaszczyńska-Nowinka, Karolina; Andrzejewska, Małgorzata; Zawierucha, Piotr; Dziegiel, Piotr; Nowicki, Michał; Ivanov, Pavel; Zabel, Maciej

    2013-08-01

    Vaults are cytoplasmic ribonucleoprotein particles composed of three proteins (MVP, TEP1, vPARP) and vault‑associated RNAs (vRNAs). Although the cellular functions of vaults remain unclear, vaults are strongly linked to the development of multidrug resistance (MDR), the major obstacle to the efficient treatment of cancers. Available published data suggest that vaults and their components are frequently upregulated in broad variety of multidrug-resistant cancer cell lines and tumors of different histological origin. Here, we provide detailed analysis of vault protein expression in post-surgery ovarian cancer samples from patients that were not exposed to chemotherapy. Our analysis suggests that vault proteins are expressed in the ovaries of healthy individuals but their expression in cancer patients is changed. Specifically, MVP, TEP1 and vPARP mRNA levels are significantly decreased in cancer samples with tendency of lower expression in higher-grade tumors. The pattern of vault protein mRNA expression is strongly correlated with the expression of other MDR-associated proteins such as MDR1, MRP1 and BCRP. Surprisingly, the protein levels of MVP, TEP1 and vPARP are actually increased in the higher‑grade tumors suggesting existence of post-transcriptional regulation of vault component production.

  4. Andrographolide Induces Apoptosis of C6 Glioma Cells via the ERK-p53-Caspase 7-PARP Pathway

    Directory of Open Access Journals (Sweden)

    Shih-Hung Yang

    2014-01-01

    Full Text Available Background. Glioma is the most malignant tumor of the central nervous system. Efforts on the development of new chemotherapy are mandatory. Andrographolide (AND, a diterpenoid lactone isolated from the Andrographis paniculata, has been shown to have antitumor activities in several types of cancer cells. Whether AND can exert its antitumor activity in glioblastoma cells remains unknown. This study examined the anticancer effects of AND, both in vitro and in vivo. Methods. Cell apoptosis was assayed by flow cytometry and nuclear staining. The signaling pathway for AND was determined by western blotting. The effects of AND on tumor growth was evaluated in a mouse model. Results and Conclusion. In vitro, with application of specific inhibitors and siRNA, AND-induced apoptosis was proven through ROS-ERK-P53-caspase 7-PARP signaling pathway. In vivo, AND significantly retarded tumor growth and caused regression of well-formed tumors in vivo. Furthermore, AND did not induce apoptosis or activate ERK and p53 in primary cultured astrocyte cells, and it may serve as a potential therapeutic candidate for the treatment of glioma.

  5. Hydrofluoric Acid-Based Derivatization Strategy To Profile PARP-1 ADP-Ribosylation by LC-MS/MS.

    Science.gov (United States)

    Gagné, Jean-Philippe; Langelier, Marie-France; Pascal, John M; Poirier, Guy G

    2018-06-11

    Despite significant advances in the development of mass spectrometry-based methods for the identification of protein ADP-ribosylation, current protocols suffer from several drawbacks that preclude their widespread applicability. Given the intrinsic heterogeneous nature of poly(ADP-ribose), a number of strategies have been developed to generate simple derivatives for effective interrogation of protein databases and site-specific localization of the modified residues. Currently, the generation of spectral signatures indicative of ADP-ribosylation rely on chemical or enzymatic conversion of the modification to a single mass increment. Still, limitations arise from the lability of the poly(ADP-ribose) remnant during tandem mass spectrometry, the varying susceptibilities of different ADP-ribose-protein bonds to chemical hydrolysis, or the context dependence of enzyme-catalyzed reactions. Here, we present a chemical-based derivatization method applicable to the confident identification of site-specific ADP-ribosylation by conventional mass spectrometry on any targeted amino acid residue. Using PARP-1 as a model protein, we report that treatment of ADP-ribosylated peptides with hydrofluoric acid generates a specific +132 Da mass signature that corresponds to the decomposition of mono- and poly(ADP-ribosylated) peptides into ribose adducts as a consequence of the cleavage of the phosphorus-oxygen bonds.

  6. Identification of an unintended consequence of Nrf2-directed cytoprotection against a key tobacco carcinogen plus a counteracting chemopreventive intervention

    Science.gov (United States)

    Paonessa, Joseph D.; Ding, Yi; Randall, Kristen L.; Munday, Rex; Argoti, Dayana; Vouros, Paul; Zhang, Yuesheng

    2011-01-01

    Nrf2 is a major cytoprotective gene and is a key chemopreventive target against cancer and other diseases. Here we show that Nrf2 faces a dilemma in defense against 4-aminobiphenyl (ABP), a major human bladder carcinogen from tobacco smoke and other environmental sources. While Nrf2 protected mouse liver against ABP (which is metabolically activated in liver), the bladder level of N-(deoxyguanosin-8-yl)-4-aminobiphenyl (dG-C8-ABP), the predominant ABP-DNA adduct formed in bladder cells and tissues, was markedly higher in Nrf2+/+ mice than in Nrf2−/− mice after ABP exposure. Notably, Nrf2 protected bladder cells against ABP in vitro. Mechanistic investigations showed that the dichotomous effects of Nrf2 could be explained at least partly by upregulation of UDP-glucuronosyltransferase (UGT). Nrf2 promoted conjugation of ABP with glucuronic acid in the liver, increasing urinary excretion of the conjugate. While glucuronidation of ABP and its metabolites is a detoxification process, these conjugates, which are excreted in urine, are known to be unstable in acidic urine, leading to delivery of the parent compounds to bladder. Hence, while higher liver UGT activity may protect the liver against ABP it increases bladder exposure to ABP. These findings raise concerns of potential bladder toxicity when Nrf2-activating chemopreventive agents are used in humans exposed to ABP, especially in smokers. We further demonstrate that 5,6-dihydrocyclopenta[c][1,2]-dithiole-3(4H)-thione (CPDT) significantly inhibits dG-C8-ABP formation in bladder cells and tissues, but does not appear to significantly modulate ABP-catalyzing UGT in liver. Thus, CPDT exemplifies a counteracting solution to the dilemma posed by Nrf2. PMID:21487034

  7. Regulating Rumination by Anger: Evidence for the Mutual Promotion and Counteraction (MPMC Theory of Emotionality

    Directory of Open Access Journals (Sweden)

    Jun Zhan

    2017-12-01

    Full Text Available Unlike the strategy of cognitive regulation that relies heavily on the top-down control function of the prefrontal cortex (PFC, which was recently found may be critically impaired in stressful situations, traditional Chinese philosophy and medicine views different types of emotionality as having mutual promotion and counteraction (MPMC relationships, implying a novel approach that requires less cognition to emotional regulation. Actually, our previous studies have indicated that anger responses could be successfully regulated via the induction of sadness, and this efficiency could not be influenced by stress, thus providing evidences for the hypothesis of “sadness counteracts anger” (SCA proposed by the MPMC theory of emotionality (Zhan et al., 2015, 2017. In this study, we experimentally examined the MPMC hypothesis that “anger counteracts rumination” (ACR which postulates that rumination may be alleviated by the anger emotion. In Study 1, all participants were initially caused state rumination and then induced anger, joy or neutral mood, the results showed that the rumination-related affect was alleviated after anger induction relative to that after joy or neutral mood induction. In Study 2, female participants with high trait rumination were recruited and divided into two groups for exposure to an anger or neutral emotion intervention, the result indicated that the anger intervention group exhibited a greater decline in trait rumination than the neutral emotion intervention group. These findings provided preliminary evidence supporting the hypothesis of ACR, which suggested a new strategy that employs less cognitive resources to regulating state and trait rumination by inducing anger.

  8. Counteracting fatigue in multiple sclerosis with right parietal anodal transcranial direct current stimulation

    Directory of Open Access Journals (Sweden)

    Katrin Hanken

    2016-09-01

    Full Text Available Background: Fatigue in multiple sclerosis (MS patients appears to correlate with vigilance decrement as reflected in an increase in reaction time and errors with prolonged time-on-task. Objectives: The aim of this study was to investigate whether anodal transcranial direct current stimulation (tDCS over the right parietal or frontal cortex counteracts fatigue-associated vigilance decrement and subjective fatigue. Methods: In study I, a randomized double-blind placebo-controlled study, anodal tDCS (1,5mA was delivered to the right parietal cortex or the right frontal cortex of 52 healthy participants during the first 20min of a 40min lasting visual vigilance task. Study II, also a randomized double-blind placebo-controlled study, investigated the effect of anodal tDCS (1.5mA over the right parietal cortex in 46 MS patients experiencing cognitive fatigue. TDCS was delivered for 20min before patients performed a 20min lasting visual vigilance task.Results: Study I showed that right parietal stimulation, but not right frontal stimulation, counteracts the increase in reaction time associated with vigilance decrement. Hence, only right parietal stimulation was applied to the MS patients in study II. Stimulation had a significant effect on vigilance decrement in mildly to moderately cognitively fatigued MS patients. Vigilance testing significantly increased the feeling of fatigue independent of stimulation.Conclusions: Anodal tDCS over the right parietal cortex can counteract the increase in reaction times during vigilance performance but not the increase in subjective fatigue. This finding is compatible with our model of fatigue in MS, suggesting a dissociation between the feeling and the behavioral characteristics of fatigue.

  9. Counteracting Fatigue in Multiple Sclerosis with Right Parietal Anodal Transcranial Direct Current Stimulation.

    Science.gov (United States)

    Hanken, Katrin; Bosse, Mona; Möhrke, Kim; Eling, Paul; Kastrup, Andreas; Antal, Andrea; Hildebrandt, Helmut

    2016-01-01

    Fatigue in multiple sclerosis (MS) patients appears to correlate with vigilance decrement as reflected in an increase in reaction time (RT) and errors with prolonged time-on-task. The aim of this study was to investigate whether anodal transcranial direct current stimulation (tDCS) over the right parietal or frontal cortex counteracts fatigue-associated vigilance decrement and subjective fatigue. In study I, a randomized double-blind placebo-controlled study, anodal tDCS (1.5 mA) was delivered to the right parietal cortex or the right frontal cortex of 52 healthy participants during the first 20 min of a 40-min lasting visual vigilance task. Study II, also a randomized double-blind placebo-controlled study, investigated the effect of anodal tDCS (1.5 mA) over the right parietal cortex in 46 MS patients experiencing cognitive fatigue. tDCS was delivered for 20 min before patients performed a 20-min lasting visual vigilance task. Study I showed that right parietal stimulation, but not right frontal stimulation, counteracts the increase in RT associated with vigilance decrement. Hence, only right parietal stimulation was applied to the MS patients in study II. Stimulation had a significant effect on vigilance decrement in mildly to moderately cognitively fatigued MS patients. Vigilance testing significantly increased the feeling of fatigue independent of stimulation. Anodal tDCS over the right parietal cortex can counteract the increase in RTs during vigilance performance, but not the increase in subjective fatigue. This finding is compatible with our model of fatigue in MS, suggesting a dissociation between the feeling and the behavioral characteristics of fatigue.

  10. Regulating Rumination by Anger: Evidence for the Mutual Promotion and Counteraction (MPMC) Theory of Emotionality

    Science.gov (United States)

    Zhan, Jun; Tang, Fan; He, Mei; Fan, Jin; Xiao, Jing; Liu, Chang; Luo, Jing

    2017-01-01

    Unlike the strategy of cognitive regulation that relies heavily on the top-down control function of the prefrontal cortex (PFC), which was recently found may be critically impaired in stressful situations, traditional Chinese philosophy and medicine views different types of emotionality as having mutual promotion and counteraction (MPMC) relationships, implying a novel approach that requires less cognition to emotional regulation. Actually, our previous studies have indicated that anger responses could be successfully regulated via the induction of sadness, and this efficiency could not be influenced by stress, thus providing evidences for the hypothesis of “sadness counteracts anger” (SCA) proposed by the MPMC theory of emotionality (Zhan et al., 2015, 2017). In this study, we experimentally examined the MPMC hypothesis that “anger counteracts rumination” (ACR) which postulates that rumination may be alleviated by the anger emotion. In Study 1, all participants were initially caused state rumination and then induced anger, joy or neutral mood, the results showed that the rumination-related affect was alleviated after anger induction relative to that after joy or neutral mood induction. In Study 2, female participants with high trait rumination were recruited and divided into two groups for exposure to an anger or neutral emotion intervention, the result indicated that the anger intervention group exhibited a greater decline in trait rumination than the neutral emotion intervention group. These findings provided preliminary evidence supporting the hypothesis of ACR, which suggested a new strategy that employs less cognitive resources to regulating state and trait rumination by inducing anger. PMID:29249998

  11. Violence and Means to Counteract Power: a View to Migrant Indigenous Women in Mexico

    Directory of Open Access Journals (Sweden)

    Sara María Lara Flores

    2003-01-01

    Full Text Available The article analizes the conditions in which women farmers incorporate into México’s exports processes. This sector has a great need of labour at the national level, which in turn brings about many migration fluxes in which indigenous women play an important role. The study shows how this feminine incorporation into the labour market triggers gender as well as ethnic inequalities that manifest themselves in a segmentation within the branches and sectors of the national economy. Also, the article describes the means to which indigenous women turn to in order to counteract the actual and symbolic violence they are submitted to.

  12. High-Intensity Interval Training as a Tool for Counteracting Dyslipidemia in Women.

    Science.gov (United States)

    Alvarez, Cristian; Ramirez-Campillo, Rodrigo; Martinez-Salazar, Cristian; Castillo, Angélica; Gallardo, Francisco; Ciolac, Emmanuel Gomes

    2018-05-01

    Sedentary overweight or obese adult (agehigh-intensity interval training (HIIT) program. Triglycerides reduced significantly ( P high-density lipoprotein increased ( P body composition improved ( P <0.05) in all groups. The HIIT program was effective for restoring lipid profile of DYS and DYSHG, and fasting glucose of DYSHG to levels similar to those of CON, with a weekly time commitment 25% to 56% lower than the minimum recommended in current exercise guidelines. These findings suggest that HIIT may be a time-efficient intervention for counteracting dyslipidemia. © Georg Thieme Verlag KG Stuttgart · New York.

  13. Genetic variants in PARP1 (rs3219090) and IRF4 (rs12203592) genes associated with melanoma susceptibility in a Spanish population

    International Nuclear Information System (INIS)

    Peña-Chilet, Maria; Ribas, Gloria; Blanquer-Maceiras, Maite; Ibarrola-Villava, Maider; Martinez-Cadenas, Conrado; Martin-Gonzalez, Manuel; Gomez-Fernandez, Cristina; Mayor, Matias; Aviles, Juan Antonio; Lluch, Ana

    2013-01-01

    Few high penetrance genes are known in Malignant Melanoma (MM), however, the involvement of low-penetrance genes such as MC1R, OCA2, ASIP, SLC45A2 and TYR has been observed. Lately, genome-wide association studies (GWAS) have been the ideal strategy to identify new common, low-penetrance susceptibility loci. In this case–control study, we try to validate in our population nine melanoma associated markers selected from published GWAS in melanoma predisposition. We genotyped the 9 markers corresponding to 8 genes (PARP1, MX2, ATM, CCND1, NADSYN1, CASP8, IRF4 and CYP2R1) in 566 cases and 347 controls from a Spanish population using KASPar probes. Genotypes were analyzed by logistic regression and adjusted by phenotypic characteristics. We confirm the protective role in MM of the rs3219090 located on the PARP1 gene (p-value 0.027). Additionally, this SNP was also associated with eye color (p-value 0.002). A second polymorphism, rs12203592, located on the IRF4 gene was associated with protection to develop MM for the dominant model (p-value 0.037). We have also observed an association of this SNP with both lentigines (p-value 0.014) and light eye color (p-value 3.76 × 10 -4 ). Furthermore, we detected a novel association with rs1485993, located on the CCND1 gene, and dark eye color (p-value 4.96 × 10 -4 ). Finally, rs1801516, located on the ATM gene, showed a trend towards a protective role in MM similar to the one firstly described in a GWAS study. To our knowledge, this is the first time that these SNPs have been associated with MM in a Spanish population. We confirmed the proposed role of rs3219090, located on the PARP1 gene, and rs12203592, located on the IRF4 gene, as protective to MM along the same lines as have previous genome-wide associated works. Finally, we have seen associations between IRF4, PARP1, and CCND1 and phenotypic characteristics, confirming previous results for the IRF4 gene and presenting novel data for the last two, suggesting that

  14. In vivo repair of DNA damage induced by X-rays in the early stages of mouse fertilization, and the influence of maternal PARP1 ablation

    Energy Technology Data Exchange (ETDEWEB)

    Pacchierotti, F., E-mail: francesca.pacchierotti@enea.it [Unit of Radiation Biology and Human Health, ENEA CR Casaccia, Via Anguillarese 301, 00123 Rome (Italy); Ranaldi, R. [Unit of Radiation Biology and Human Health, ENEA CR Casaccia, Via Anguillarese 301, 00123 Rome (Italy); Derijck, A.A.; Heijden, G.W. van der; Boer, P. de [Radboud University Nijmegen Medical Centre, Department of Obstetrics and Gynaecology, P.O. Box 9101, 6500 HB Nijmegen (Netherlands)

    2011-09-01

    Highlights: {yields} We measure {gamma}H2AX and chromosome aberrations in mouse zygotes irradiated in vivo. {yields} We compare effects between zygotes obtained from wild type or Parp1 knockout females. {yields} The rate of chromosome aberrations is as high as that previously induced in vitro. {yields} The rate of radiation-induced {gamma}H2AX foci is lower than that measured in other cells. {yields} Without Parp1 there are more {gamma}H2AX foci but chromosome aberration rate is unaffected. - Abstract: The early pronucleus stage of the mouse zygote has been characterised in vitro as radiosensitive, due to a high rate of induction of chromosome-type chromosome abnormalities (CA). We have investigated the repair of irradiation induced double strand DNA breaks in vivo by {gamma}H2AX foci and first cleavage metaphase analysis. Breaks were induced in sperm and in the early zygote stages comprising sperm chromatin remodelling and early pronucleus expansion. Moreover, the role of PARP1 in the formation and repair of spontaneous and radiation-induced double strand breaks in the zygote was evaluated by comparing observations in C57BL/6J and PARP1 genetically ablated females. The results confirmed in vivo that the rate of chromosome aberration induction by X-rays was approximately 3-fold higher in the zygote than in mouse lymphocytes. This finding was related to a diminished efficiency of double strand break signalling, as shown by a lower rate of {gamma}H2AX radiation-induced foci compared to that measured in most other somatic cell types. The spontaneous frequency of CA in PARP1 depleted zygotes was slightly but significantly higher than in wild type zygotes. Also, these zygotes showed some impairment of the radiation-induced DNA Damage Response when exposed closer to the start of S-phase, revealed by a higher number of {gamma}H2AX foci and a longer cell cycle delay. The rate of chromosome aberrations, however, was not elevated over that of wild type zygotes, possibly

  15. Arsenite-induced ROS/RNS generation causes zinc loss and inhibits the activity of poly (ADP-ribose) polymerase-1

    OpenAIRE

    Wang, Feng; Zhou, Xixi; Liu, Wenlan; Sun, Xi; Chen, Chen; Hudson, Laurie G.; Liu, Ke Jian

    2013-01-01

    Arsenic enhances genotoxicity of other carcinogenic agents such as ultraviolet radiation and benzo[a]pyrene. Recent reports suggest that inhibition of DNA repair is an important aspect of arsenic co-carcinogenesis, and DNA repair proteins such as poly (ADP ribose) polymerase (PARP)-1 are direct molecular targets of arsenic. Although arsenic has been shown to generate reactive oxygen/nitrogen species (ROS/RNS), little is known about the role of arsenic-induced ROS/RNS in the mechanism underlyi...

  16. Current means for raising efficiency of counteraction to counterfeit goods trafficking

    Directory of Open Access Journals (Sweden)

    Dronova O.B.

    2014-12-01

    Full Text Available The urgency of counteraction to counterfeit goods trafficking is shown. Annual loss due to counterfeit goods producing and trafficking reaches several billion dollars. There remains a danger of buying low-quality and counterfeit goods despite implementing new producing techniques and protective elements. Measures, taken by law enforcement agencies, state authorities and public human rights organizations have not led to systematic suppression of producing and trafficking of such goods. Creation of new information and reference resource, containing information blocks of protective symbols on goods and packages and illustrated materials comprising patterns of discovered counterfeit goods, can assist to increase public awareness and to give necessary information to law enforcement agencies. Organizations, realizing state and social protection of consumers and entrepreneurs, along with producers, rightholders’ representatives and law enforcement bodies can accept the responsibility of creating and functioning this information and reference system in the Internet. Such level of cooperation of all interested organizations will allow to raise efficiency of measures for counteraction to trafficking goods with violated consumer properties. The author proves the necessity to organize functioning of information and reference resource for a wide range of users. Operation of such resource should comply with main principles of generating any information resource, notably full scale, authenticity and relevance of information. The author proposes the algorithm of creating such system which provides cooperation of law enforcement agencies, producers and consumers for the purpose of preventing counterfeit goods trafficking and investigating committed crimes.

  17. Effect of IR Laser on Myoblasts: Prospects of Application for Counteracting Microgravity-Induced Muscle Atrophy

    Science.gov (United States)

    Monici, Monica; Cialdai, Francesca; Romano, Giovanni; Corsetto, Paola Antonia; Rizzo, Angela Maria; Caselli, Anna; Ranaldi, Francesco

    2013-02-01

    Microgravity-induced muscle atrophy is a problem of utmost importance for the impact it may have on the health and performance of astronauts. Therefore, appropriate countermeasures are needed to prevent disuse atrophy and favour muscle recovery. Muscle atrophy is characterized by loss of muscle mass and strength, and a shift in substrate utilization from fat to glucose, that leads to a reduced metabolic efficiency and enhanced fatigability. Laser therapy is already used in physical medicine and rehabilitation to accelerate muscle recovery and in sports medicine to prevent damages produced by metabolic disturbances and inflammatory reactions after heavy exercise. The aim of the research we present was to get insights on possible benefits deriving from the application of an advanced infrared laser system to counteract deficits of muscle energy metabolism and stimulate the recovery of the hypotrophic tissue. The source used was a Multiwave Locked System (MLS) laser, which combines continuous and pulsed emissions at 808 nm and 905 nm, respectively. We studied the effect of MLS treatment on morphology and energy metabolism of C2C12 cells, a widely accepted myoblast model, previously exposed to microgravity conditions modelled by a Random Positioning Machine. The MLS laser treatment was able to restore basal levels of serine/threonine protein phosphatase activity and to counteract cytoskeletal alterations and increase in glycolytic enzymes activity that occurred following the exposure to modelled microgravity. In conclusion, the results provide interesting insights for the application of infrared laser in the treatment of muscle atrophy.

  18. Human Neural Stem Cell Aging Is Counteracted by α-Glycerylphosphorylethanolamine.

    Science.gov (United States)

    Daniele, Simona; Da Pozzo, Eleonora; Iofrida, Caterina; Martini, Claudia

    2016-07-20

    Neural stem cells (NSCs) represent a subpopulation of cells, located in specific regions of the adult mammalian brain, with the ability of self-renewing and generating neurons and glia. In aged NSCs, modifications in the amount and composition of membrane proteins/lipids, which lead to a reduction in membrane fluidity and cholinergic activities, have been reported. In this respect, molecules that are effective at normalizing the membrane composition and cholinergic signaling could counteract stem cell aging. α-Glycerylphosphorylethanolamine (GPE), a nootropic drug, plays a role in phospholipid biosynthesis and acetylcholine release. Herein, GPE was assayed on human NSC cultures and on hydroxyurea-aged cells. Using cell counting, colorimetric, and fluorimetric analyses, immunoenzymatic assays, and real time PCR experiments, NSC culture proliferation, senescence, reactive oxygen species, and ADP/ATP levels were assessed. Aged NSCs exhibited cellular senescence, decreased proliferation, and an impairment in mitochondrial metabolism. These changes included a substantial induction in the nuclear factor NF-κB, a key inflammatory mediator. GPE cell treatment significantly protected the redox state and functional integrity of mitochondria, and counteracted senescence and NF-κB activation. In conclusion, our data show the beneficial properties of GPE in this model of stem cell aging.

  19. Tamoxifen counteracts estradiol induced effects on striatal and hypophyseal dopamine receptors

    Energy Technology Data Exchange (ETDEWEB)

    Ferretti, C.; Blengio, M.; Ghi, P.; Racca, S.; Genazzani, E.; Portaleone, P.

    1988-01-01

    We investigated the ability of Tamoxifen (TAM), an antiestrogen drug, to counteract the modification induced by estrogens on dopamine (DA) receptors on striatum and on adenohypophysis of ovex female rats. Subacute treatment with 17..beta..-estradiol (E/sub 2/) at both low (0.1 ..mu..g/kg) and high (20 ..mu..g/kg) doses confirmed its ability to increase the number of striatal /sup 3/H-Spiperone (/sup 3/H-SPI) binding sites in a dose dependent manner. By contrast in the pituitary, only high doses of estrogen were effective in reducing the number of DA receptors. We treated ovex female rats for 15 days with TAM alone or associated with E/sub 2/, to see if these estrogenic effects could be suppressed by an antiestrogenic drug. TAM did not affect the number of striatal DA receptors, but significantly increased the adenohypophy-seal DA binding sites, without varying their affinity. No changes were observed in pituitary and striatal DA receptor density, even when TAM was injected in association with estradiol. In conclusions: TAM is able to counteract the effects estrogens have on DA receptors. However there is some evidence that it could influence the pituitary DA systems independently of it antiestrogenic activity.

  20. Retrograde Signaling from Progranulin to Sort1 Counteracts Synapse Elimination in the Developing Cerebellum.

    Science.gov (United States)

    Uesaka, Naofumi; Abe, Manabu; Konno, Kohtarou; Yamazaki, Maya; Sakoori, Kazuto; Watanabe, Takaki; Kao, Tzu-Huei; Mikuni, Takayasu; Watanabe, Masahiko; Sakimura, Kenji; Kano, Masanobu

    2018-02-21

    Elimination of redundant synapses formed early in development and strengthening of necessary connections are crucial for shaping functional neural circuits. Purkinje cells (PCs) in the neonatal cerebellum are innervated by multiple climbing fibers (CFs) with similar strengths. A single CF is strengthened whereas the other CFs are eliminated in each PC during postnatal development. The underlying mechanisms, particularly for the strengthening of single CFs, are poorly understood. Here we report that progranulin, a multi-functional growth factor implicated in the pathogenesis of frontotemporal dementia, strengthens developing CF synaptic inputs and counteracts their elimination from postnatal day 11 to 16. Progranulin derived from PCs acts retrogradely onto its putative receptor Sort1 on CFs. This effect is independent of semaphorin 3A, another retrograde signaling molecule that counteracts CF synapse elimination. We propose that progranulin-Sort1 signaling strengthens and maintains developing CF inputs, and may contribute to selection of single "winner" CFs that survive synapse elimination. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Acidosis counteracts itch tachyphylaxis to consecutive pruritogen exposure dependent on acid-sensing ion channel 3.

    Science.gov (United States)

    Jiang, Yi-Ming; Huang, Chen; Peng, Zhong; Han, Shao-Ling; Li, Wei-Guang; Zhu, Michael Xi; Xu, Tian-Le

    2017-01-01

    Tachyphylaxis of itch refers to a markedly reduced scratching response to consecutive exposures of a pruritogen, a process thought to protect against tissue damage by incessant scratching and to become disrupted in chronic itch. Here, we report that a strong stimulation of the Mas-related G-protein-coupled receptor C11 by its agonist, Ser-Leu-Ile-Gly-Arg-Leu-NH 2 (SL-NH 2 ) or bovine adrenal medulla 8-22 peptide, via subcutaneous injection in mice induces tachyphylaxis to the subsequent application of SL-NH 2 to the same site. Notably, co-application of acid and SL-NH 2 following the initial injection of the pruritogen alone counteracted itch tachyphylaxis by augmenting the scratching behaviors in wild-type but not in acid-sensing ion channel 3-null, animals. Using an activity-dependent silencing strategy, we identified that acid-sensing ion channel 3-mediated itch enhancement mainly occurred via the Mas-related G-protein-coupled receptor C11-responsive sensory neurons. Together, our results indicate that acid-sensing ion channel 3, activated by concomitant acid and certain pruritogens, constitute a novel signaling pathway that counteracts itch tachyphylaxis to successive pruritogenic stimulation, which likely contributes to chronic itch associated with tissue acidosis.

  2. Tamoxifen counteracts estradiol induced effects on striatal and hypophyseal dopamine receptors

    International Nuclear Information System (INIS)

    Ferretti, C.; Blengio, M.; Ghi, P.; Racca, S.; Genazzani, E.; Portaleone, P.

    1988-01-01

    We investigated the ability of Tamoxifen (TAM), an antiestrogen drug, to counteract the modification induced by estrogens on dopamine (DA) receptors on striatum and on adenohypophysis of ovex female rats. Subacute treatment with 17β-estradiol (E 2 ) at both low (0.1 μg/kg) and high (20 μg/kg) doses confirmed its ability to increase the number of striatal 3 H-Spiperone ( 3 H-SPI) binding sites in a dose dependent manner. By contrast in the pituitary, only high doses of estrogen were effective in reducing the number of DA receptors. We treated ovex female rats for 15 days with TAM alone or associated with E 2 , to see if these estrogenic effects could be suppressed by an antiestrogenic drug. TAM did not affect the number of striatal DA receptors, but significantly increased the adenohypophy-seal DA binding sites, without varying their affinity. No changes were observed in pituitary and striatal DA receptor density, even when TAM was injected in association with estradiol. In conclusions: TAM is able to counteract the effects estrogens have on DA receptors. However there is some evidence that it could influence the pituitary DA systems independently of it antiestrogenic activity

  3. cGMP-Phosphodiesterase Inhibition Prevents Hypoxia-Induced Cell Death Activation in Porcine Retinal Explants.

    Directory of Open Access Journals (Sweden)

    Lorena Olivares-González

    Full Text Available Retinal hypoxia and oxidative stress are involved in several retinal degenerations including diabetic retinopathy, glaucoma, central retinal artery occlusion, or retinopathy of prematurity. The second messenger cyclic guanosine monophosphate (cGMP has been reported to be protective for neuronal cells under several pathological conditions including ischemia/hypoxia. The purpose of this study was to evaluate whether the accumulation of cGMP through the pharmacological inhibition of phosphodiesterase (PDE with Zaprinast prevented retinal degeneration induced by mild hypoxia in cultures of porcine retina. Exposure to mild hypoxia (5% O2 for 24h reduced cGMP content and induced retinal degeneration by caspase dependent and independent (PARP activation mechanisms. Hypoxia also produced a redox imbalance reducing antioxidant response (superoxide dismutase and catalase activities and increasing superoxide free radical release. Zaprinast reduced mild hypoxia-induced cell death through inhibition of caspase-3 or PARP activation depending on the cell layer. PDE inhibition also ameliorated the effects of mild hypoxia on antioxidant response and the release of superoxide radical in the photoreceptor layer. The use of a PKG inhibitor, KT5823, suggested that cGMP-PKG pathway is involved in cell survival and antioxidant response. The inhibition of PDE, therefore, could be useful for reducing retinal degeneration under hypoxic/ischemic conditions.

  4. Housing, energy cost, and the poor: Counteracting effects in Germany's housing allowance program

    International Nuclear Information System (INIS)

    Groesche, Peter

    2010-01-01

    Adequate housing and affordable warmth are essential human needs, the lack of which may seriously harm people's health. Germany provides an allowance to low-income households, covering the housing as well as the space heating cost, to protect people from the consequences of poor housing conditions and fuel poverty. In order to limit public expenditures, payment recipients are required to choose low-cost dwellings, with the consequence that they probably occupy flats with a poor thermal performance. Recipients might therefore exhibit a lower per-square meter rent but in turn are likely to have a higher energy consumption and energy expenditures. Using a large data set of German households, this paper demonstrates that this financially counteracting effect is of negligible magnitude.

  5. Stevioside counteracts the alpha cell hypersecretion caused by long-term palmitate exposure

    DEFF Research Database (Denmark)

    Hong, Jing; Chen, Jianguo; Jeppesen, Per Bendix

    2006-01-01

    Long-term exposure to fatty acids impairs beta-cell function in type 2 diabetes, but little is known about the chronic effects of fatty acids on alpha-cells. We therefore studied the prolonged impact of palmitate on alpha-cell function and on the expression of genes related to fuel metabolism. We......-activated receptor-gamma, and stearoyl-CoA desaturase gene expressions in the presence of palmitate (Pacids leads to a hypersecretion of glucagon and an accumulation of TG content in clonal alpha-TC1-6 cells. Stevioside was able to counteract the alpha......-cell hypersecretion caused by palmitate and enhanced the expression of genes involved in fatty acid metabolism. This indicates that stevioside may be a promising antidiabetic agent in treatment of type 2 diabetes....

  6. In vitro generation of polysialylated cervical mucins by bacterial polysialyltransferases to counteract cytotoxicity of extracellular histones.

    Science.gov (United States)

    Galuska, Sebastian P; Galuska, Christina E; Tharmalingam, Tharmala; Zlatina, Kristina; Prem, Gerlinde; Husejnov, Farzali C O; Rudd, Pauline M; Vann, Willie F; Reid, Colm; Vionnet, Justine; Gallagher, Mary E; Carrington, Faye A; Hassett, Sarah-Louise; Carrington, Stephen D

    2017-06-01

    Neutrophil extracellular traps (NET) are formed against pathogens. However, various diseases are directly linked to this meshwork of DNA. The cytotoxic properties of extracellular histones especially seem to be an important trigger during these diseases. Furthermore, NET accumulation on implants is discussed to result in an impaired efficiency or failure, depending on the category of implant. Interestingly, mucins have been investigated as surface coatings potentially capable of reducing neutrophil adhesion. Similarly, polysialic acid was shown to inactivate the cytotoxic properties of extracellular histones. We wanted to combine the probability to decrease the adhesion of neutrophils using mucins with the capability of sialic acid polymers to counteract histone-mediated cytotoxicity. To this end, we elongate cervical mucins using bacterial polysialyltransferases. Subsequent cell-based experiments demonstrated the activity of elongated mucins against histone-mediated cytotoxicity. Thus, polysialylated mucins may represent a novel component to coat implants or to combat diseases with exaggerated NET formation. © 2017 Federation of European Biochemical Societies.

  7. Feline Immunodeficiency Virus Vif N-Terminal Residues Selectively Counteract Feline APOBEC3s.

    Science.gov (United States)

    Gu, Qinyong; Zhang, Zeli; Cano Ortiz, Lucía; Franco, Ana Cláudia; Häussinger, Dieter; Münk, Carsten

    2016-12-01

    Feline immunodeficiency virus (FIV) Vif protein counteracts feline APOBEC3s (FcaA3s) restriction factors by inducing their proteasomal degradation. The functional domains in FIV Vif for interaction with FcaA3s are poorly understood. Here, we have identified several motifs in FIV Vif that are important for selective degradation of different FcaA3s. Cats (Felis catus) express three types of A3s: single-domain A3Z2, single-domain A3Z3, and double-domain A3Z2Z3. We proposed that FIV Vif would selectively interact with the Z2 and the Z3 A3s. Indeed, we identified two N-terminal Vif motifs (12LF13 and 18GG19) that specifically interacted with the FcaA3Z2 protein but not with A3Z3. In contrast, the exclusive degradation of FcaA3Z3 was regulated by a region of three residues (M24, L25, and I27). Only a FIV Vif carrying a combination of mutations from both interaction sites lost the capacity to degrade and counteract FcaA3Z2Z3. However, alterations in the specific A3s interaction sites did not affect the cellular localization of the FIV Vif protein and binding to feline A3s. Pulldown experiments demonstrated that the A3 binding region localized to FIV Vif residues 50 to 80, outside the specific A3 interaction domain. Finally, we found that the Vif sites specific to individual A3s are conserved in several FIV lineages of domestic cat and nondomestic cats, while being absent in the FIV Vif of pumas. Our data support a complex model of multiple Vif-A3 interactions in which the specific region for selective A3 counteraction is discrete from a general A3 binding domain. Both human immunodeficiency virus (HIV) and feline immunodeficiency virus (FIV) Vif proteins counteract their host's APOBEC3 restriction factors. However, these two Vif proteins have limited sequence homology. The molecular interaction between FIV Vif and feline APOBEC3s are not well understood. Here, we identified N-terminal FIV Vif sites that regulate the selective interaction of Vif with either feline APOBEC3Z

  8. Malaysian adolescent students' needs for enhancing thinking skills, counteracting risk factors and demonstrating academic resilience

    Science.gov (United States)

    Kuldas, Seffetullah; Hashim, Shahabuddin; Ismail, Hairul Nizam

    2015-01-01

    The adolescence period of life comes along with changes and challenges in terms of physical and cognitive development. In this hectic period, many adolescents may suffer more from various risk factors such as low socioeconomic status, substance abuse, sexual abuse and teenage pregnancy. Findings indicate that such disadvantaged backgrounds of Malaysian adolescent students lead to failure or underachievement in their academic performance. This narrative review scrutinises how some of these students are able to demonstrate academic resilience, which is satisfactory performance in cognitive or academic tasks in spite of their disadvantaged backgrounds. The review stresses the need for developing a caregiving relationship model for at-risk adolescent students in Malaysia. Such a model would allow educators to meet the students' needs for enhancing thinking skills, counteracting risk factors and demonstrating academic resilience. PMID:25663734

  9. Reduced estradiol-induced vasodilation and poly-(ADP-ribose polymerase (PARP activity in the aortas of rats with experimental polycystic ovary syndrome (PCOS.

    Directory of Open Access Journals (Sweden)

    Gabriella Masszi

    Full Text Available Polycystic ovary syndrome (PCOS is a complex endocrine disorder characterized by hyperandrogenism and insulin resistance, both of which have been connected to atherosclerosis. Indeed, an increased risk of clinical manifestations of arterial vascular diseases has been described in PCOS. On the other hand endothelial dysfunction can be detected early on, before atherosclerosis develops. Thus we assumed that vascular dysfunction is also related directly to the hormonal imbalance rather than to its metabolic consequences. To detect early functional changes, we applied a novel rodent model of PCOS: rats were either sham operated or hyperandrogenism was achieved by implanting subcutaneous pellets of dihydrotestosterone (DHT. After ten weeks, myograph measurements were performed on isolated aortic rings. Previously we described an increased contractility to norepinephrine (NE. Here we found a reduced immediate relaxation to estradiol treatment in pre-contracted aortic rings from hyperandrogenic rats. Although the administration of vitamin D3 along with DHT reduced responsiveness to NE, it did not restore relaxation to estradiol. Poly-(ADP-ribose polymerase (PARP activity was assessed by poly-ADP-ribose immunostaining. Increased PAR staining in ovaries and circulating leukocytes from DHT rats showed enhanced DNA damage, which was reduced by concomitant vitamin D3 treatment. Surprisingly, PAR staining was reduced in both the endothelium and vascular smooth muscle cells of the aorta rings from hyperandrogenic rats. Thus in the early phase of PCOS, vascular tone is already shifted towards vasoconstriction, characterized by reduced vasorelaxation and vascular dysfunction is concomitant with altered PARP activity. Based on our findings, PARP inhibitors might have a future perspective in restoring metabolic disorders in PCOS.

  10. Reduced estradiol-induced vasodilation and poly-(ADP-ribose) polymerase (PARP) activity in the aortas of rats with experimental polycystic ovary syndrome (PCOS).

    Science.gov (United States)

    Masszi, Gabriella; Horvath, Eszter Maria; Tarszabo, Robert; Benko, Rita; Novak, Agnes; Buday, Anna; Tokes, Anna-Maria; Nadasy, Gyorgy L; Hamar, Peter; Benyó, Zoltán; Varbiro, Szabolcs

    2013-01-01

    Polycystic ovary syndrome (PCOS) is a complex endocrine disorder characterized by hyperandrogenism and insulin resistance, both of which have been connected to atherosclerosis. Indeed, an increased risk of clinical manifestations of arterial vascular diseases has been described in PCOS. On the other hand endothelial dysfunction can be detected early on, before atherosclerosis develops. Thus we assumed that vascular dysfunction is also related directly to the hormonal imbalance rather than to its metabolic consequences. To detect early functional changes, we applied a novel rodent model of PCOS: rats were either sham operated or hyperandrogenism was achieved by implanting subcutaneous pellets of dihydrotestosterone (DHT). After ten weeks, myograph measurements were performed on isolated aortic rings. Previously we described an increased contractility to norepinephrine (NE). Here we found a reduced immediate relaxation to estradiol treatment in pre-contracted aortic rings from hyperandrogenic rats. Although the administration of vitamin D3 along with DHT reduced responsiveness to NE, it did not restore relaxation to estradiol. Poly-(ADP-ribose) polymerase (PARP) activity was assessed by poly-ADP-ribose immunostaining. Increased PAR staining in ovaries and circulating leukocytes from DHT rats showed enhanced DNA damage, which was reduced by concomitant vitamin D3 treatment. Surprisingly, PAR staining was reduced in both the endothelium and vascular smooth muscle cells of the aorta rings from hyperandrogenic rats. Thus in the early phase of PCOS, vascular tone is already shifted towards vasoconstriction, characterized by reduced vasorelaxation and vascular dysfunction is concomitant with altered PARP activity. Based on our findings, PARP inhibitors might have a future perspective in restoring metabolic disorders in PCOS.

  11. [Expression of PARP/NF-κB and intervention effect of 5-AIQ/PDTC in SAP rats with adrenal damage].

    Science.gov (United States)

    Yang, Bo; Guo, Wen-Yi; Yu, Jia; Zhao, Kai-liang; Shi, Qiao; Zuo, Teng; Wang, Wei-xing

    2013-10-15

    To explore the expression of poly (ADP-ribose) polymerase/nuclear factor-κB (PARP/NF-κB) and intervention effect of 5-aminoisoquinolinone/pyrrolidine dithiocarbamate (5-AIQ/PDTC) in severe acute pancreatitis (SAP) rats with adrenal damage. The primarily cultured adrenocortical cells were quantitatively divided into control group (SO), pancreatitis group (SAP), PDTC drug control group (SO+PDTC), PDTC intervention group (SAP+PDTC), 5-AIQ drug control group (SO+ 5-AIQ) and 5-AIQ intervention group (SAP+5-AIQ). The SAP and 2 intervention groups were stimulated with the sera of SAP rats. Then corresponding drugs were added and culture continued for 12 hours. The corticosterone levels and PARP/NF-κB expression were observed for each group. Adrenal cells in vitro cultured were round or oval, had secretory granules and could be stained by 3β-hydroxysteroid dehydrogenase antibody. The adherence rate was 60% after 48-hour culturing. The corticosterone level of SAP group was significantly lower than that of SO group [ (216.4 ± 15.7) vs (294.8 ± 16.3) µg/L, P SAP group (P SAP and PDTC intervention groups were higher than SO group while 5-AIQ intervention group was significantly lower than SAP and PDTC intervention groups, but higher than SO and drug control groups. The expression of NF-κB in SAP group was higher than that in SO group. Two intervention groups were lower than SAP group, but higher than SO and drug control groups. The pathway of PARP/NF-κB participates in adrenal damage of SAP rats. To a certain extent, the uses of 5-AIQ and PDTC may alleviate adrenal damage.

  12. Docosahexaenoic acid counteracts attenuation of CD95-induced cell death by inorganic mercury

    International Nuclear Information System (INIS)

    Gill, Randall; Lanni, Lydia; Jen, K.-L. Catherine; McCabe, Michael J.; Rosenspire, Allen

    2015-01-01

    In the United States the principal environmental exposure to mercury is through dietary consumption of sea food. Although the mechanism by which low levels of mercury affect the nervous system is not well established, epidemiological studies suggest that low level exposure of pregnant women to dietary mercury can adversely impact cognitive development in their children, but that Docosahexaenoic acid (DHA), the most prominent n-polyunsaturated fatty acid (n-PUFA) present in fish may counteract negative effects of mercury on the nervous system. Aside from effects on the nervous system, epidemiological and animal studies have also suggested that low level mercury exposure may be a risk factor for autoimmune disease. However unlike the nervous system where a mechanism linking mercury to impaired cognitive development remains elusive, we have previously suggested a potential mechanism linking low level mercury exposures to immune system dysfunction and autoimmunity. In the immune system it is well established that disruption of CD95 mediated apoptosis leads to autoimmune disease. We have previously shown in vitro as well as in vivo that in lymphocytes burdened with low levels of mercury, CD95 mediated cell death is impaired. In this report we now show that DHA counteracts the negative effect of mercury on CD95 signaling in T lymphocytes. T cells which have been pre-exposed to DHA are able to cleave pro-caspase 3 and efficiently signal programmed cell death through the CD95 signaling pathway, whether or not they are burdened with low levels of mercury. Thus DHA may lower the risk of autoimmune disease after low level mercury exposures. - Highlights: • Inorganic mercury (Hg 2+ ) interferes with CD95 mediated cell death in Jurkat T cells • DHA restores the ability of CD95 to signal cell death in Hg 2+ intoxicated T cells • The restoration of CD95 mediated cell death by DHA is correlated with increased activation of Caspase 3

  13. Docosahexaenoic acid counteracts attenuation of CD95-induced cell death by inorganic mercury

    Energy Technology Data Exchange (ETDEWEB)

    Gill, Randall [Department of Immunology and Microbiology, Wayne State University, Detroit MI (United States); Lanni, Lydia; Jen, K.-L. Catherine [Department of Nutrition and Food Science, Wayne State University, Detroit MI (United States); McCabe, Michael J. [Department of Environmental Medicine, University of Rochester, Rochester NY (United States); Rosenspire, Allen, E-mail: arosenspire@wayne.edu [Department of Immunology and Microbiology, Wayne State University, Detroit MI (United States)

    2015-01-01

    In the United States the principal environmental exposure to mercury is through dietary consumption of sea food. Although the mechanism by which low levels of mercury affect the nervous system is not well established, epidemiological studies suggest that low level exposure of pregnant women to dietary mercury can adversely impact cognitive development in their children, but that Docosahexaenoic acid (DHA), the most prominent n-polyunsaturated fatty acid (n-PUFA) present in fish may counteract negative effects of mercury on the nervous system. Aside from effects on the nervous system, epidemiological and animal studies have also suggested that low level mercury exposure may be a risk factor for autoimmune disease. However unlike the nervous system where a mechanism linking mercury to impaired cognitive development remains elusive, we have previously suggested a potential mechanism linking low level mercury exposures to immune system dysfunction and autoimmunity. In the immune system it is well established that disruption of CD95 mediated apoptosis leads to autoimmune disease. We have previously shown in vitro as well as in vivo that in lymphocytes burdened with low levels of mercury, CD95 mediated cell death is impaired. In this report we now show that DHA counteracts the negative effect of mercury on CD95 signaling in T lymphocytes. T cells which have been pre-exposed to DHA are able to cleave pro-caspase 3 and efficiently signal programmed cell death through the CD95 signaling pathway, whether or not they are burdened with low levels of mercury. Thus DHA may lower the risk of autoimmune disease after low level mercury exposures. - Highlights: • Inorganic mercury (Hg{sup 2+}) interferes with CD95 mediated cell death in Jurkat T cells • DHA restores the ability of CD95 to signal cell death in Hg{sup 2+} intoxicated T cells • The restoration of CD95 mediated cell death by DHA is correlated with increased activation of Caspase 3.

  14. The characteristics of the pediatric model for counteracting obesity in Serbia

    Directory of Open Access Journals (Sweden)

    Banićević Miloš

    2012-01-01

    Full Text Available Basic data on the establishment, features and results of the health care system for children and adolescents in the Republic of Serbia during the period 1950-1990 are given in the introductory remarks. Enormous pressure for the change of the health sector ownership and the profile of physicians in the primary pediatric care in the last decade of 20th century and at the beginning of 21st century is also emphasized. The destructive consequences of the sanctions of international community (1992-1995, NATO aggression (1999 and the change of the political system in Serbia (2000 caused the huge loss of gross domestic product, increase of the unemployment and poverty rates, and the decrease of the health expenditure rate to unsustainable levels (200-300 USD per capita. In spite of all misfortunes, Pediatric Association of Serbia, in response to the global obesity epidemic, offered in 2007 to the Ministry of health and the National Institute for health insurance the Project 'The prevention and treatment of obesity in children and adolescents in Serbia', as the pediatric chapter for future National strategy for counteracting obesity. The Project, ie the pediatric model for counteracting obesity is funded on the features of the health care system for children and adolescents in our country. The solidarity of the society and the continuous education of health care workers, adolescents and their parents about the significance of obesity epidemic are, in our conviction, key factors for the strengthening of adolescent's conscience on individual responsibility for own health as the prerequisite for successful control of obesity epidemic in adolescents.

  15. Maintenance of lettuce seed viability and counter-action of radiation damage by moisture equilibration-drying treatment

    International Nuclear Information System (INIS)

    Punjabi, Bina; Basu, R.N.

    1982-01-01

    Lettuce seeds were subjected to X- and gamma-radiation after moisture equilibration-drying or they were equilibrated with a saturated atmosphere for 24 hrs immediately after irradiation followed by drying back to the original weight. Results showed that moisture-equilibration drying treatment either before or after irradiation counteracts the adverse effects of irradiation. (M.G.B.)

  16. Maintenance of lettuce seed viability and counter-action of radiation damage by moisture equilibration-drying treatment

    Energy Technology Data Exchange (ETDEWEB)

    Punjabi, B; Basu, R N

    1982-10-01

    Lettuce seeds were subjected to X- and gamma-radiation after moisture equilibration-drying or they were equilibrated with a saturated atmosphere for 24 hrs immediately after irradiation followed by drying back to the original weight. Results showed that moisture-equilibration drying treatment either before or after irradiation counteracts the adverse effects of irradiation. (M.G.B.). 14 refs.

  17. Lactoferrin Efficiently Counteracts the Inflammation-Induced Changes of the Iron Homeostasis System in Macrophages.

    Science.gov (United States)

    Cutone, Antimo; Rosa, Luigi; Lepanto, Maria Stefania; Scotti, Mellani Jinnett; Berlutti, Francesca; Bonaccorsi di Patti, Maria Carmela; Musci, Giovanni; Valenti, Piera

    2017-01-01

    Human lactoferrin (hLf), an 80-kDa multifunctional iron-binding cationic glycoprotein, is constitutively secreted by exocrine glands and by neutrophils during inflammation. hLf is recognized as a key element in the host immune defense system. The in vitro and in vivo experiments are carried out with bovine Lf (bLf), which shares high sequence homology and identical functions with hLf, including anti-inflammatory activity. Here, in "pure" M1 human macrophages, obtained by stimulation with a mixture of 10 pg/ml LPS and 20 ng/ml IFN-γ, as well as in a more heterogeneous macrophage population, challenged with high-dose of LPS (1 µg/ml), the effect of bLf on the expression of the main proteins involved in iron and inflammatory homeostasis, namely ferroportin (Fpn), membrane-bound ceruloplasmin (Cp), cytosolic ferritin (Ftn), transferrin receptor 1, and cytokines has been investigated. The increase of IL-6 and IL-1β cytokines, following the inflammatory treatments, is associated with both upregulation of cytosolic Ftn and downregulation of Fpn, membrane-bound Cp, and transferrin receptor 1. All these changes take part into intracellular iron overload, a very unsafe condition leading in vivo to higher host susceptibility to infections as well as iron deficiency in the blood and anemia of inflammation. It is, therefore, of utmost importance to counteract the persistence of the inflammatory status to rebalance iron levels between tissues/secretions and blood. Moreover, levels of the antiinflammatory cytokine IL-10 were increased in cells treated with high doses of LPS. Conversely, IL-10 decreased when the LPS/IFN-γ mix was used, suggesting that only the inflammation triggered by LPS high doses can switch on an anti-inflammatory response in our macrophagic model. Here, we demonstrate that bLf, when included in the culture medium, significantly reduced IL-6 and IL-1β production and efficiently prevented the changes of Fpn, membrane-bound Cp, cytosolic Ftn, and

  18. Lactoferrin Efficiently Counteracts the Inflammation-Induced Changes of the Iron Homeostasis System in Macrophages

    Directory of Open Access Journals (Sweden)

    Antimo Cutone

    2017-06-01

    Full Text Available Human lactoferrin (hLf, an 80-kDa multifunctional iron-binding cationic glycoprotein, is constitutively secreted by exocrine glands and by neutrophils during inflammation. hLf is recognized as a key element in the host immune defense system. The in vitro and in vivo experiments are carried out with bovine Lf (bLf, which shares high sequence homology and identical functions with hLf, including anti-inflammatory activity. Here, in “pure” M1 human macrophages, obtained by stimulation with a mixture of 10 pg/ml LPS and 20 ng/ml IFN-γ, as well as in a more heterogeneous macrophage population, challenged with high-dose of LPS (1 µg/ml, the effect of bLf on the expression of the main proteins involved in iron and inflammatory homeostasis, namely ferroportin (Fpn, membrane-bound ceruloplasmin (Cp, cytosolic ferritin (Ftn, transferrin receptor 1, and cytokines has been investigated. The increase of IL-6 and IL-1β cytokines, following the inflammatory treatments, is associated with both upregulation of cytosolic Ftn and downregulation of Fpn, membrane-bound Cp, and transferrin receptor 1. All these changes take part into intracellular iron overload, a very unsafe condition leading in vivo to higher host susceptibility to infections as well as iron deficiency in the blood and anemia of inflammation. It is, therefore, of utmost importance to counteract the persistence of the inflammatory status to rebalance iron levels between tissues/secretions and blood. Moreover, levels of the antiinflammatory cytokine IL-10 were increased in cells treated with high doses of LPS. Conversely, IL-10 decreased when the LPS/IFN-γ mix was used, suggesting that only the inflammation triggered by LPS high doses can switch on an anti-inflammatory response in our macrophagic model. Here, we demonstrate that bLf, when included in the culture medium, significantly reduced IL-6 and IL-1β production and efficiently prevented the changes of Fpn, membrane-bound Cp

  19. Corrosion inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, A O

    1965-12-29

    An acid corrosion-inhibiting composition consists essentially of a sugar, and an alkali metal salt selected from the group consisting of iodides and bromides. The weight ratio of the sugar to the alkali metal salt is between 2:1 and about 20,000:1. Also, a corrosion- inhibited phosphoric acid composition comprising at least about 20 wt% of phosphoric acid and between about 0.1 wt% and about 10 wt% of molasses, and between about 0.0005 wt% and about 1 wt% of potassium iodide. The weight ratio of molasses to iodide is greater than about 2:1. (11 claims)

  20. Positive Alpha and Negative Beta (A Strategy for Counteracting Systematic Risk

    Directory of Open Access Journals (Sweden)

    Erik Sonne Noddeboe

    2015-09-01

    Full Text Available Undiversifiable (or systematic risk has long been an enemy of investors. Many countercyclical strategies have been developed to counter this. However, like all insurance types, these strategies are generally costly to implement, and over time can significantly reduce portfolio returns in long and extended bull markets. In this paper, we discuss an alternative technique, founded on the premise of physiological bias and risk-aversion. We take a behavioral discussion in order to contextualize the insurance like characteristics of option pricing and discuss how this can lead to a mispricing of the asymmetric relationship between the VIX and the S&P 500. To test this, we perform studies in which we find statistical inefficiencies, thereby making it possible to implement a method of hedging index option premium in a way that has displayed no monthly drawdowns in bullish periods, while still providing large returns in major sell-offs. The three versions of the strategy discussed have negative betas to the S&P 500, while exhibiting similar risk-adjusted excess returns over both bull and bear markets. Further, the performance generated over the entire period, for all three strategies, is highly statistically significant. The results challenge the weak form of the Efficient Market Hypothesis and provide evidence that the methods of hedging could be a valuable addition to an equity rich portfolio for the purpose of counteracting systematic risk.

  1. Green tea (-)-epigallocatechin-3-gallate counteracts daytime overeating induced by high-fat diet in mice.

    Science.gov (United States)

    Li, Hongyu; Kek, Huiling Calvina; Lim, Joy; Gelling, Richard Wayne; Han, Weiping

    2016-12-01

    High-fat diet (HFD) induces overeating and obesity. Green tea (-)-epigallocatechin-3-gallate (EGCG) reduces HFD-induced body weight and body fat gain mainly through increased lipid metabolism and fat oxidation. However, little is known about its effect on HFD-induced alterations in feeding behavior. Three diet groups of wildtype C57B/6j male mice at 5 months old were fed on normal chow diet, 1 week of HFD (60% of energy) and 3 months of HFD (diet-induced obesity (DIO)) prior to EGCG supplement in respective diet. EGCG had no effect on feeding behavior in normal chow diet group. Increased daytime feeding induced by HFD was selectively corrected by EGCG treatment in HFD groups, including reversed food intake, feeding frequency and meal size in HFD + EGCG group, and reduced food intake and feeding frequency in DIO + EGCG group. Moreover, EGCG treatment altered diurnally oscillating expression pattern of key appetite-regulating genes, including AGRP, POMC, and CART, and key circadian genes Clock and Bmal1 in hypothalamus of DIO mice, indicating its central effect on feeding regulation. Our study demonstrates that EGCG supplement specifically counteracts daytime overeating induced by HFD in mice, suggesting its central role in regulating feeding behavior and energy homeostasis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. HSV-1 ICP0: An E3 Ubiquitin Ligase That Counteracts Host Intrinsic and Innate Immunity

    Directory of Open Access Journals (Sweden)

    Mirna Perusina Lanfranca

    2014-05-01

    Full Text Available The herpes simplex virus type 1 (HSV-1 encoded E3 ubiquitin ligase, infected cell protein 0 (ICP0, is required for efficient lytic viral replication and regulates the switch between the lytic and latent states of HSV-1. As an E3 ubiquitin ligase, ICP0 directs the proteasomal degradation of several cellular targets, allowing the virus to counteract different cellular intrinsic and innate immune responses. In this review, we will focus on how ICP0’s E3 ubiquitin ligase activity inactivates the host intrinsic defenses, such as nuclear domain 10 (ND10, SUMO, and the DNA damage response to HSV-1 infection. In addition, we will examine ICP0’s capacity to impair the activation of interferon (innate regulatory mediators that include IFI16 (IFN γ-inducible protein 16, MyD88 (myeloid differentiation factor 88, and Mal (MyD88 adaptor-like protein. We will also consider how ICP0 allows HSV-1 to evade activation of the NF-κB (nuclear factor kappa B inflammatory signaling pathway. Finally, ICP0’s paradoxical relationship with USP7 (ubiquitin specific protease 7 and its roles in intrinsic and innate immune responses to HSV-1 infection will be discussed.

  3. Anthocyanin-rich extract from Hibiscus sabdariffa calyx counteracts UVC-caused impairments in rats.

    Science.gov (United States)

    Ozkol, Hatice Uce; Koyuncu, Ismail; Tuluce, Yasin; Dilsiz, Nihat; Soral, Sinan; Ozkol, Halil

    2015-01-01

    Ultraviolet radiation (UV) was reported to cause oxidative stress. Hibiscus sabdariffa L. (Malvaceae) calyx is commonly used in traditional Asian and African medicines and possesses strong antioxidant capacity due to its anthocyanin (ANTH) content. This study researched the possible protective role of Hibiscus sabdariffa calyx extract (HSCE) in UVC exposure of rats. Levels of serum enzymes, renal function tests, and some oxidant/antioxidant biomarkers of skin, lens, and retina tissues were monitored. Rats were exposed to UVC 4 h daily for 40 d and simultaneously received HSCE containing 2.5, 5, and 10 mg doses of ANTH in drinking water. Significant (p < 0.05) increases in the levels of serum aminotransferases, lactate dehydrogenase, urea, creatinine, and uric acid were noted after UVC exposure. In skin, lens, and retina tissues, total oxidant status, oxidative stress index, lipid peroxidation, and protein oxidation escalated markedly (p < 0.05) whereas total antioxidant status, reduced glutathione, and superoxide dismutase decreased dramatically (p < 0.05) related to UVC. Co-administration of HSCE with each ANTH dose significantly (p < 0.05) reversed aforementioned parameters (except total oxidant status) almost in all tissues. The LD50 of HSCE in rats was determined to be above 5000 mg/kg. Our data revealed that HSCE has a remarkable potential to counteract UVC-caused impairments, probably through its antioxidant and free radical-defusing effects. Therefore, HSCE could be useful against some cutaneous and ocular diseases in which UV and oxidative stress have a role in the etiopathogenesis.

  4. Counteracting Rotor Imbalance in a Bearingless Motor System with Feedforward Control

    Science.gov (United States)

    Kascak, Peter Eugene; Jansen, Ralph H.; Dever, Timothy; Nagorny, Aleksandr; Loparo, Kenneth

    2012-01-01

    In standard motor applications, traditional mechanical bearings represent the most economical approach to rotor suspension. However, in certain high performance applications, rotor suspension without bearing contact is either required or highly beneficial. Such applications include very high speed, extreme environment, or limited maintenance access applications. This paper extends upon a novel bearingless motor concept, in which full five-axis levitation and rotation of the rotor is achieved using two motors with opposing conical air-gaps. By leaving the motors' pole-pairs unconnected, different d-axis flux in each pole-pair is created, generating a flux imbalance which creates lateral force. Note this is approach is different than that used in previous bearingless motors, which use separate windings for levitation and rotation. This paper will examine the use of feedforward control to counteract synchronous whirl caused by rotor imbalance. Experimental results will be presented showing the performance of a prototype bearingless system, which was sized for a high speed flywheel energy storage application, with and without feedforward control.

  5. Exendin-4 induces cell adhesion and differentiation and counteracts the invasive potential of human neuroblastoma cells.

    Science.gov (United States)

    Luciani, Paola; Deledda, Cristiana; Benvenuti, Susanna; Squecco, Roberta; Cellai, Ilaria; Fibbi, Benedetta; Marone, Ilaria Maddalena; Giuliani, Corinna; Modi, Giulia; Francini, Fabio; Vannelli, Gabriella Barbara; Peri, Alessandro

    2013-01-01

    Exendin-4 is a molecule currently used, in its synthetic form exenatide, for the treatment of type 2 diabetes mellitus. Exendin-4 binds and activates the Glucagon-Like Peptide-1 Receptor (GLP-1R), thus inducing insulin release. More recently, additional biological properties have been associated to molecules that belong to the GLP-1 family. For instance, Peptide YY and Vasoactive Intestinal Peptide have been found to affect cell adhesion and migration and our previous data have shown a considerable actin cytoskeleton rearrangement after exendin-4 treatment. However, no data are currently available on the effects of exendin-4 on tumor cell motility. The aim of this study was to investigate the effects of this molecule on cell adhesion, differentiation and migration in two neuroblastoma cell lines, SH-SY5Y and SK-N-AS. We first demonstrated, by Extra Cellular Matrix cell adhesion arrays, that exendin-4 increased cell adhesion, in particular on a vitronectin substrate. Subsequently, we found that this molecule induced a more differentiated phenotype, as assessed by i) the evaluation of neurite-like protrusions in 3D cell cultures, ii) the analysis of the expression of neuronal markers and iii) electrophysiological studies. Furthermore, we demonstrated that exendin-4 reduced cell migration and counteracted anchorage-independent growth in neuroblastoma cells. Overall, these data indicate for the first time that exendin-4 may have anti-tumoral properties.

  6. Protein Phosphatase 1 Recruitment by Rif1 Regulates DNA Replication Origin Firing by Counteracting DDK Activity

    Directory of Open Access Journals (Sweden)

    Anoushka Davé

    2014-04-01

    Full Text Available The firing of eukaryotic origins of DNA replication requires CDK and DDK kinase activities. DDK, in particular, is involved in setting the temporal program of origin activation, a conserved feature of eukaryotes. Rif1, originally identified as a telomeric protein, was recently implicated in specifying replication timing in yeast and mammals. We show that this function of Rif1 depends on its interaction with PP1 phosphatases. Mutations of two PP1 docking motifs in Rif1 lead to early replication of telomeres in budding yeast and misregulation of origin firing in fission yeast. Several lines of evidence indicate that Rif1/PP1 counteract DDK activity on the replicative MCM helicase. Our data suggest that the PP1/Rif1 interaction is downregulated by the phosphorylation of Rif1, most likely by CDK/DDK. These findings elucidate the mechanism of action of Rif1 in the control of DNA replication and demonstrate a role of PP1 phosphatases in the regulation of origin firing.

  7. FGFR2-Driven Signaling Counteracts Tamoxifen Effect on ERα-Positive Breast Cancer Cells

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    Lukasz Turczyk

    2017-10-01

    Full Text Available Signaling mediated by growth factors receptors has long been suggested as one of the key factors responsible for failure of endocrine treatment in breast cancer (BCa. Herein we present that in the presence of tamoxifen, FGFs (Fibroblast Growth Factors promote BCa cell growth with the strongest effect being produced by FGF7. FGFR2 was identified as a mediator of FGF7 action and the FGFR2-induced signaling was found to underlie cancer-associated fibroblasts-dependent resistance to tamoxifen. FGF7/FGFR2-triggered pathway was shown to induce ER phosphorylation, ubiquitination and subsequent ER proteasomal degradation which counteracted tamoxifen-promoted ER stabilization. We also identified activation of PI3K/AKT signaling targeting ER-Ser167 and regulation of Bcl-2 expression as a mediator of FGFR2-promoted resistance to tamoxifen. Analysis of tissue samples from patients with invasive ductal carcinoma revealed an inversed correlation between expression of FGFR2 and ER, thus supporting our in vitro data. These results unveil the complexity of ER regulation by FGFR2-mediated signaling likely to be associated with BCa resistance to endocrine therapy.

  8. Clomipramine counteracts lipid raft disturbance due to short-term muscle disuse.

    Science.gov (United States)

    Bryndina, Irina G; Shalagina, Maria N; Sekunov, Alexey V; Zefirov, Andrei L; Petrov, Alexey M

    2018-01-18

    Disuse-induced skeletal muscle dysfunction is a serious consequence of long-term spaceflight, numerous diseases and conditions for which treatment possibilities are still strictly limited. We have previously shown that acute hindlimb suspension (HS)-mediated disuse disrupts membrane lipid rafts in the unloaded muscle. Here, we investigated whether pretreatment of rats with the inhibitor of acid sphingomyelinase, clomipramine (1.25mg/g/day, intramuscularly, for 5days before HS), is able to hinder the loss in lipid raft integrity in response to 12h of HS. Clomipramine pretreatment significantly counteracted the decrease in labeling of the plasma membranes with lipid raft markers (fluorescent cholera toxin B subunit and bodipy-GM1-ganglioside) specifically in the junctional regions of the suspended soleus muscle. This was associated with: a) enhancing raft disrupting potential of exogenous sphingomyelinase in the junctional membranes; b) prevention of both ceramide accumulation and cholesterol loss; c) prevention of decline in nicotinic acetylcholine receptor labeling in the unloaded muscle. Our data suggest that sphingomyelinase-mediated raft disturbance serves as one of the earlier events in HS effects. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Apricot melanoidins prevent oxidative endothelial cell death by counteracting mitochondrial oxidation and membrane depolarization.

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    Annalisa Cossu

    Full Text Available The cardiovascular benefits associated with diets rich in fruit and vegetables are thought to be due to phytochemicals contained in fresh plant material. However, whether processed plant foods provide the same benefits as unprocessed ones is an open question. Melanoidins from heat-processed apricots were isolated and their presence confirmed by colorimetric analysis and browning index. Oxidative injury of endothelial cells (ECs is the key step for the onset and progression of cardiovascular diseases (CVD, therefore the potential protective effect of apricot melanoidins on hydrogen peroxide-induced oxidative mitochondrial damage and cell death was explored in human ECs. The redox state of cytoplasmic and mitochondrial compartments was detected by using the redox-sensitive, fluorescent protein (roGFP, while the mitochondrial membrane potential (MMP was assessed with the fluorescent dye, JC-1. ECs exposure to hydrogen peroxide, dose-dependently induced mitochondrial and cytoplasmic oxidation. Additionally detected hydrogen peroxide-induced phenomena were MMP dissipation and ECs death. Pretreatment of ECs with apricot melanoidins, significantly counteracted and ultimately abolished hydrogen peroxide-induced intracellular oxidation, mitochondrial depolarization and cell death. In this regard, our current results clearly indicate that melanoidins derived from heat-processed apricots, protect human ECs against oxidative stress.

  10. Personal values that support and counteract utilization of a screening test for prostate cancer.

    Science.gov (United States)

    Aavik, Toivo; Aavik, Anu; Punab, Margus

    2014-01-01

    The main aim of the current research was to discover the personal values that may support men's prostate cancer screening decisions in the future. We asked for participants' past behavior and future behavioral intentions, and also considered their real-life behavior. The sample consisted of 371 men, of which 93 were first-time patients at the Andrology Unit. The results show that Security value was related to past participation, while Achievement, Stimulation, and Traditions counteracted this. Present prostate-testing behavior was related only to higher Security values. Predictors of future behavioral intentions were Security, Self-direction, and Benevolence, which described 21% of the total variability. Considering informed decision-making processes, our results suggest that men who hold Security, Self-direction, and Benevolence values are more likely to participate in office-based initial screening. The study indicates the need to offer office-based initial screening to those age-eligible men whose values do not support participation.

  11. Feebates promoting energy-efficient cars: Design options to address more consumers and possible counteracting effects

    International Nuclear Information System (INIS)

    Peters, Anja; Mueller, Michel G.; Haan, Peter de; Scholz, Roland W.

    2008-01-01

    An increasing number of countries have implemented or are evaluating feebate systems in order to reduce energy consumption of new vehicle registrations. We distinguish between absolute feebates based strictly on a vehicle's energy consumption and relative feebates normalizing energy consumption by a given car utility. This paper analyzes whether absolute or relative feebates encourage more consumers to change to vehicles with lower energy consumption. We combine an analysis of all car models on sale at the end of 2005 with survey data from 326 potential new car buyers. Analysis of the car fleet with regard to behavioral changes assumed as realistic shows that relative systems succeed better in offering more consumer groups cars that are eligible for incentives. Survey results suggest that consumers show some, but limited, willingness to change behavior to obtain an incentive. However, a relative system potentially allows people to switch to cars with higher relative efficiency without actually lowering absolute CO 2 emissions. We discuss this inherent dilemma of simultaneously addressing more consumers and limiting counteracting effects. In order to find the optimal trade-off, we suggest assessing different parameters operationalizing vehicle utility by means of micro-simulation with detailed car fleet and differentiated consumer segments

  12. MyT1 Counteracts the Neural Progenitor Program to Promote Vertebrate Neurogenesis

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    Francisca F. Vasconcelos

    2016-10-01

    Full Text Available The generation of neurons from neural stem cells requires large-scale changes in gene expression that are controlled to a large extent by proneural transcription factors, such as Ascl1. While recent studies have characterized the differentiation genes activated by proneural factors, less is known on the mechanisms that suppress progenitor cell identity. Here, we show that Ascl1 induces the transcription factor MyT1 while promoting neuronal differentiation. We combined functional studies of MyT1 during neurogenesis with the characterization of its transcriptional program. MyT1 binding is associated with repression of gene transcription in neural progenitor cells. It promotes neuronal differentiation by counteracting the inhibitory activity of Notch signaling at multiple levels, targeting the Notch1 receptor and many of its downstream targets. These include regulators of the neural progenitor program, such as Hes1, Sox2, Id3, and Olig1. Thus, Ascl1 suppresses Notch signaling cell-autonomously via MyT1, coupling neuronal differentiation with repression of the progenitor fate.

  13. Developing Tools to Counteract and Prevent Suicide Bomber Incidents: A Case Study in Value Sensitive Design.

    Science.gov (United States)

    Royakkers, Lambèr; Steen, Marc

    2017-08-01

    Developers and designers make all sorts of moral decisions throughout an innovation project. In this article, we describe how teams of developers and designers engaged with ethics in the early phases of innovation based on case studies in the SUBCOP project (SUBCOP stands for 'SUicide Bomber COunteraction and Prevention'). For that purpose, Value Sensitive Design (VSD) will be used as a reference. Specifically, we focus on the following two research questions: How can researchers/developers learn about users' perspectives and values during the innovation process? and How can researchers/developers take into account these values, and related design criteria, in their decision-making during the innovation process? Based on a case study of several innovation processes in this project, we conclude the researchers/developers involved are able to do something similar to VSD (without them knowing about VSD or calling it 'VSD'), supported by relatively simple exercises in the project, e.g., meetings with potential end-users and discussions with members of the Ethical Advisory Board of the project. Furthermore, we also found-possibly somewhat counterintuitively-that a commercial, with its focus on understanding and satisfying customers' needs, can promote VSD.

  14. RTEL1 dismantles T loops and counteracts telomeric G4-DNA to maintain telomere integrity.

    Science.gov (United States)

    Vannier, Jean-Baptiste; Pavicic-Kaltenbrunner, Visnja; Petalcorin, Mark I R; Ding, Hao; Boulton, Simon J

    2012-05-11

    T loops and telomeric G-quadruplex (G4) DNA structures pose a potential threat to genome stability and must be dismantled to permit efficient telomere replication. Here we implicate the helicase RTEL1 in the removal of telomeric DNA secondary structures, which is essential for preventing telomere fragility and loss. In the absence of RTEL1, T loops are inappropriately resolved by the SLX4 nuclease complex, resulting in loss of the telomere as a circle. Depleting SLX4 or blocking DNA replication abolished telomere circles (TCs) and rescued telomere loss in RTEL1(-/-) cells but failed to suppress telomere fragility. Conversely, stabilization of telomeric G4-DNA or loss of BLM dramatically enhanced telomere fragility in RTEL1-deficient cells but had no impact on TC formation or telomere loss. We propose that RTEL1 performs two distinct functions at telomeres: it disassembles T loops and also counteracts telomeric G4-DNA structures, which together ensure the dynamics and stability of the telomere. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Escherichia coli α-hemolysin counteracts the anti-virulence innate immune response triggered by the Rho GTPase activating toxin CNF1 during bacteremia.

    Directory of Open Access Journals (Sweden)

    Mamady Diabate

    2015-03-01

    Full Text Available The detection of the activities of pathogen-encoded virulence factors by the innate immune system has emerged as a new paradigm of pathogen recognition. Much remains to be determined with regard to the molecular and cellular components contributing to this defense mechanism in mammals and importance during infection. Here, we reveal the central role of the IL-1β signaling axis and Gr1+ cells in controlling the Escherichia coli burden in the blood in response to the sensing of the Rho GTPase-activating toxin CNF1. Consistently, this innate immune response is abrogated in caspase-1/11-impaired mice or following the treatment of infected mice with an IL-1β antagonist. In vitro experiments further revealed the synergistic effects of CNF1 and LPS in promoting the maturation/secretion of IL-1β and establishing the roles of Rac, ASC and caspase-1 in this pathway. Furthermore, we found that the α-hemolysin toxin inhibits IL-1β secretion without affecting the recruitment of Gr1+ cells. Here, we report the first example of anti-virulence-triggered immunity counteracted by a pore-forming toxin during bacteremia.

  16. The angiotensin-(1-7/Mas axis counteracts angiotensin II-dependent and –independent pro-inflammatory signaling in human vascular smooth muscle cells

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    Laura A Villalobos

    2016-12-01

    Full Text Available Background and aims: Targeting inflammation is nowadays considered as a challenging pharmacological strategy to prevent or delay the development of vascular diseases. Angiotensin-(1-7 is a member of the renin-angiotensin system (RAS that binds Mas receptors and has gained growing attention in the last years as a regulator of vascular homeostasis. Here, we explored the capacity of Ang-(1-7 to counteract human aortic smooth muscle cell (HASMC inflammation triggered by RAS-dependent and –independent stimuli, such as Ang II or interleukin (IL-1.Methods and Results: In cultured HASMC, the expression of iNOS and the release of nitric oxide were stimulated by both Ang II and IL-1, as determined by Western blot and indirect immunofluorescence or the Griess method, respectively. iNOS induction was inhibited by Ang-(1-7 in a concentration-dependent manner. This effect was equally blocked by two different Mas receptor antagonists, A779 and D-Pro7-Ang-(1-7, suggesting the participation of a unique Mas receptor subtype. Using pharmacological inhibitors, the induction of iNOS was proven to rely on the consecutive upstream activation of NADPH oxidase and NF-B. Indeed, Ang-(1-7 markedly inhibited the activation of the NADPH oxidase and subsequently of NF-B, as determined by lucigenin-derived chemiluminiscence and electromobility shift assay, respectively.Conclusion: Ang-(1-7 can act as a counter-regulator of the inflammation of vascular smooth muscle cells triggered by Ang II, but also by other stimuli beyond the RAS. Activating or mimicking the Ang-(1-7/Mas axis may represent a pharmacological opportunity to attenuate the pro-inflammatory environment that promotes and sustains the development of vascular diseases.

  17. Tapirira guianensis Aubl. Extracts Inhibit Proliferation and Migration of Oral Cancer Cells Lines

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    Renato José Silva-Oliveira

    2016-11-01

    Full Text Available Cancer of the head and neck is a group of upper aerodigestive tract neoplasms in which aggressive treatments may cause harmful side effects to the patient. In the last decade, investigations on natural compounds have been particularly successful in the field of anticancer drug research. Our aim is to evaluate the antitumor effect of Tapirira guianensis Aubl. extracts on a panel of head and neck squamous cell carcinoma (HNSCC cell lines. Analysis of secondary metabolites classes in fractions of T. guianensis was performed using Nuclear Magnetic Resonance (NMR. Mutagenicity effect was evaluated by Ames mutagenicity assay. The cytotoxic effect, and migration and invasion inhibition were measured. Additionally, the expression level of apoptosis-related molecules (PARP, Caspases 3, and Fas and MMP-2 was detected using Western blot. Heterogeneous cytotoxicity response was observed for all fractions, which showed migration inhibition, reduced matrix degradation, and decreased cell invasion ability. Expression levels of MMP-2 decreased in all fractions, and particularly in the hexane fraction. Furthermore, overexpression of FAS and caspase-3, and increase of cleaved PARP indicates possible apoptosis extrinsic pathway activation. Antiproliferative activity of T. guianensis extract in HNSCC cells lines suggests the possibility of developing an anticancer agent or an additive with synergic activities associated with conventional anticancer therapy.

  18. Breast Cancer Resistance Protein (BCRP/ABCG2) and P-glycoprotein (P-GP/ABCB1) Restrict Oral Availability and Brain Accumulation of the PARP Inhibitor Rucaparib (AG-014699)

    NARCIS (Netherlands)

    Durmus, Selvi; Sparidans, Rolf W; van Esch, Anita; Wagenaar, Els; Beijnen, Jos H; Schinkel, Alfred H

    BACKGROUND: Rucaparib is a potent, orally available, small-molecule inhibitor of poly ADP-ribose polymerase (PARP) 1 and 2. Ongoing clinical trials are assessing the efficacy of rucaparib alone or in combination with other cytotoxic drugs, mainly in breast and ovarian cancer patients with mutations

  19. MECHANISMS OF COUNTERACTING FLAP-VALVE BRONCHIAL OBSTRUCTION IN CASE OF OBSTRUCTIVE PULMONARY EMPHYSEMA

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    K. F. Tetenev

    2015-01-01

    Full Text Available The research goal was to formulate and substantiate the hypothesis explaining support for an expiratory air flow in case of pulmonary emphysema. The research method consisted in comparing the mechanical properties of lungs in practically healthy individuals (37 individuals, mean age – (30.4 ± 1.7 y.o. and COPD patients with pronounced lung emphysema (30 patients, mean age – (52.1 ± 2.3 y.o. as well as those of isolated normal lungs (n = 14 and isolated lungs of patients who died of COPD (n = 5. Pulmo-nary mechanics was studied via the simultaneous measurement of transpulmonary pressure and lung ven-tilation volume. General lung hysteresis and elastic lung hysteresis were calculated. The mechanical properties of isolated lungs were studied using passive ventilation under the Donders bell. The air flow was interrupted in order to measure alveolar pressure and develop an elastic lung hysteresis curve. Pres-sure in the Donders bell was changed by means of a special pump in automatic and manual modes. The research has not revealed any fundamental differences between the mechanical properties of the normal and emphysematous lungs. A minimum increase in the pressure inside the Donders bell over atmospheric pressure used to stop air ejection in both normal and the emphysematous lungs as the result of flap-valve bronchial obstruction. In living beings, air is ejected from lungs with an increase in pressure under the conditions of forced expiration. Pressure increases up to (38.6 ± 2.71 cm H2O in healthy individuals and up to (20.5 ± 1.86 cm H2O in COPD patients. Probably, an expiratory air flow is supported by active expiratory bronchial dilatation that counteracts flap-valve bronchial obstruction. The hypothesis is based on the confirmed ability of the lungs to perform inspiratory actions (in addition to the action of respiratory muscles and the theory of mechanical lung activity.

  20. Selenium-Induced Toxicity Is Counteracted by Sulfur in Broccoli (Brassica oleracea L. var. italica).

    Science.gov (United States)

    Tian, Ming; Hui, Maixia; Thannhauser, Theodore W; Pan, Siyi; Li, Li

    2017-01-01

    Selenium (Se) is an essential micronutrient for humans. Increasing Se content in food crops offers an effective approach to enhance the consumption of Se in human diets. A thoroughly understanding of the effects of Se on plant growth is important for Se biofortification in food crops. Given that Se is an analog of sulfur (S) and can be toxic to plants, its effect on plant growth is expected to be greatly affected by S nutrition. However, this remains to be further understood. Here, we evaluated the influence of Se treatments on broccoli ( Brassica oleracea L. var. italica ) growth when S was withheld from the growth nutrient solution. We found that Se was highly toxic to plants when S nutrition was poor. In contrast to Se treatments with adequate S nutrition that slightly reduced broccoli growth, the same concentration of Se treatments without S supplementation dramatically reduced plant sizes. Higher Se toxicity was observed with selenate than selenite under low S nutrition. We examined the bases underlying the toxicity. We discovered that the high Se toxicity in low S nutrition was specifically associated with an increased ratio of Se in proteins verse total Se level, enhanced generation of reactive oxygen species, elevated lipid peroxidation causing increased cell membrane damage, and reduced antioxidant enzyme activities. Se toxicity could be counteracted with increased supplementation of S, which is likely through decreasing non-specific integration of Se into proteins and altering the redox system. The present study provides information for better understanding of Se toxicity and shows that adequate S nutrition is important to prevent Se toxicity during biofortification of crops by Se fertilization.

  1. Candida utilis and Chlorella vulgaris counteract intestinal inflammation in Atlantic salmon (Salmo salar L..

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    Fabian Grammes

    Full Text Available Intestinal inflammation, caused by impaired intestinal homeostasis, is a serious condition in both animals and humans. The use of conventional extracted soybean meal (SBM in diets for Atlantic salmon and several other fish species is known to induce enteropathy in the distal intestine, a condition often referred to as SBM induced enteropathy (SBMIE. In the present study, we investigated the potential of different microbial ingredients to alleviate SBMIE in Atlantic salmon, as a model of feed-induced inflammation. The dietary treatments consisted of a negative control based on fish meal (FM, a positive control based on 20% SBM, and four experimental diets combining 20% SBM with either one of the three yeasts Candida utilis (CU, Kluyveromyces marxianus (KM, Saccharomyces cerevisiae (SC or the microalgae Chlorella vulgaris (CV. Histopathological examination of the distal intestine showed that all fish fed the SC or SBM diets developed characteristic signs of SBMIE, while those fed the FM, CV or CU diets showed a healthy intestine. Fish fed the KM diet showed intermediate signs of SBMIE. Corroborating results were obtained when measuring the relative length of PCNA positive cells in the crypts of the distal intestine. Gene set enrichment analysis revealed decreased expression of amino acid, fat and drug metabolism pathways as well as increased expression of the pathways for NOD-like receptor signalling and chemokine signalling in both the SC and SBM groups while CV and CU were similar to FM and KM was intermediate. Gene expression of antimicrobial peptides was reduced in the groups showing SBMIE. The characterisation of microbial communities using PCR-DGGE showed a relative increased abundance of Firmicutes bacteria in fish fed the SC or SBM diets. Overall, our results show that both CU and CV were highly effective to counteract SBMIE, while KM had less effect and SC had no functional effects.

  2. Counteracting chemical chaperone effects on the single-molecule α-synuclein structural landscape.

    Science.gov (United States)

    Ferreon, Allan Chris M; Moosa, Mahdi Muhammad; Gambin, Yann; Deniz, Ashok A

    2012-10-30

    Protein structure and function depend on a close interplay between intrinsic folding energy landscapes and the chemistry of the protein environment. Osmolytes are small-molecule compounds that can act as chemical chaperones by altering the environment in a cellular context. Despite their importance, detailed studies on the role of these chemical chaperones in modulating structure and dimensions of intrinsically disordered proteins have been limited. Here, we used single-molecule Förster resonance energy transfer to test the counteraction hypothesis of counterbalancing effects between the protecting osmolyte trimethylamine-N-oxide (TMAO) and denaturing osmolyte urea for the case of α-synuclein, a Parkinson's disease-linked protein whose monomer exhibits significant disorder. The single-molecule experiments, which avoid complications from protein aggregation, do not exhibit clear solvent-induced cooperative protein transitions for these osmolytes, unlike results from previous studies on globular proteins. Our data demonstrate the ability of TMAO and urea to shift α-synuclein structures towards either more compact or expanded average dimensions. Strikingly, the experiments directly reveal that a 21 [urea][TMAO] ratio has a net neutral effect on the protein's dimensions, a result that holds regardless of the absolute osmolyte concentrations. Our findings shed light on a surprisingly simple aspect of the interplay between urea and TMAO on α-synuclein in the context of intrinsically disordered proteins, with potential implications for the biological roles of such chemical chaperones. The results also highlight the strengths of single-molecule experiments in directly probing the chemical physics of protein structure and disorder in more chemically complex environments.

  3. Housing in Pyramid Counteracts Neuroendocrine and Oxidative Stress Caused by Chronic Restraint in Rats

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    M. Surekha Bhat

    2007-01-01

    Full Text Available The space within the great pyramid and its smaller replicas is believed to have an antistress effect. Research has shown that the energy field within the pyramid can protect the hippocampal neurons of mice from stress-induced atrophy and also reduce neuroendocrine stress, oxidative stress and increase antioxidant defence in rats. In this study, we have, for the first time, attempted to study the antistress effects of pyramid exposure on the status of cortisol level, oxidative damage and antioxidant status in rats during chronic restraint stress. Adult female Wistar rats were divided into four groups as follows: normal controls (NC housed in home cage and left in the laboratory; restrained rats (with three subgroups subject to chronic restraint stress by placing in a wire mesh restrainer for 6 h per day for 14 days, the restrained controls (RC having their restrainers kept in the laboratory; restrained pyramid rats (RP being kept in the pyramid; and restrained square box rats (RS in the square box during the period of restraint stress everyday. Erythrocyte malondialdehyde (MDA and plasma cortisol levels were significantly increased and erythrocyte-reduced glutathione (GSH levels, erythrocyte glutathione peroxidase (GSH-Px and superoxide dismutase (SOD activities were significantly decreased in RC and RS rats as compared to NC. However, these parameters were maintained to near normal levels in RP rats which showed significantly decreased erythrocyte MDA and plasma cortisol and significantly increased erythrocyte GSH levels, erythrocyte GSH-Px and SOD activities when compared with RS rats. The results showed that housing in pyramid counteracts neuroendocrine and oxidative stress caused by chronic restraint in rats.

  4. The N-end rule pathway counteracts cell death by destroying proapoptotic protein fragments.

    Science.gov (United States)

    Piatkov, Konstantin I; Brower, Christopher S; Varshavsky, Alexander

    2012-07-03

    In the course of apoptosis, activated caspases cleave ∼500 to ∼1,000 different proteins in a mammalian cell. The dynamics of apoptosis involve a number of previously identified, caspase-generated proapoptotic protein fragments, defined as those that increase the probability of apoptosis. In contrast to activated caspases, which can be counteracted by inhibitor of apoptosis proteins, there is little understanding of antiapoptotic responses to proapoptotic protein fragments. One possibility is the regulation of proapoptotic fragments through their selective degradation. The previously identified proapoptotic fragments Cys-RIPK1, Cys-TRAF1, Asp-BRCA1, Leu-LIMK1, Tyr-NEDD9, Arg-BID, Asp-BCL(XL), Arg-BIM(EL), Asp-EPHA4, and Tyr-MET bear destabilizing N-terminal residues. Tellingly, the destabilizing nature (but not necessarily the actual identity) of N-terminal residues of proapoptotic fragments was invariably conserved in evolution. Here, we show that these proapoptotic fragments are short-lived substrates of the Arg/N-end rule pathway. Metabolic stabilization of at least one such fragment, Cys-RIPK1, greatly augmented the activation of the apoptosis-inducing effector caspase-3. In agreement with this understanding, even a partial ablation of the Arg/N-end rule pathway in two specific N-end rule mutants is shown to sensitize cells to apoptosis. We also found that caspases can inactivate components of the Arg/N-end rule pathway, suggesting a mutual suppression between this pathway and proapoptotic signaling. Together, these results identify a mechanistically specific and functionally broad antiapoptotic role of the Arg/N-end rule pathway. In conjunction with other apoptosis-suppressing circuits, the Arg/N-end rule pathway contributes to thresholds that prevent a transient or otherwise weak proapoptotic signal from reaching the point of commitment to apoptosis.

  5. Effects of counteracting external valgus moment on lateral tibial cartilage contact conditions and tibial rotation.

    Science.gov (United States)

    Shriram, Duraisamy; Parween, Rizuwana; Lee, Yee Han Dave; Subburaj, Karupppasamy

    2017-07-01

    Knee osteoarthritis that prevalently occurs at the medial compartment is a progressive chronic disorder affecting the articular cartilage of the knee joint, and lead to loss of joint functionality. Valgus braces have been used as a treatment procedure to unload the medial compartment for patients with medial osteoarthritis. Valgus braces through the application of counteracting external valgus moment shift the load from medial compartment towards the lateral compartment. Previous biomechanical studies focused only on the changes in varus moments before and after wearing the brace. The objective of this study was to investigate the influence of opposing external valgus moment applied by knee braces on the lateral tibial cartilage contact conditions using a 3D finite element model of the knee joint. Finite element simulations were performed on the knee joint model without and with the application of opposing valgus moment to mimic the unbraced and braced conditions. Lateral tibial cartilage contact pressures and contact area, and tibial rotation (varus-valgus and internal-external) were estimated for the complete walking gait cycle. The opposing valgus moment increased the maximum contact pressure and contact area on the lateral tibial cartilage compared to the normal gait moment. A peak contact pressure of 8.2 MPa and maximum cartilage loaded area of 28% (loaded cartilage nodes) on the lateral cartilage with the application of external valgus moment were induced at 50% of the gait cycle. The results show that the use of opposing valgus moment may significantly increase the maximum contact pressures and contact area on the lateral tibial cartilage and increases the risk of articular cartilage damage on the lateral compartment.

  6. Selenium-Induced Toxicity Is Counteracted by Sulfur in Broccoli (Brassica oleracea L. var. italica

    Directory of Open Access Journals (Sweden)

    Ming Tian

    2017-08-01

    Full Text Available Selenium (Se is an essential micronutrient for humans. Increasing Se content in food crops offers an effective approach to enhance the consumption of Se in human diets. A thoroughly understanding of the effects of Se on plant growth is important for Se biofortification in food crops. Given that Se is an analog of sulfur (S and can be toxic to plants, its effect on plant growth is expected to be greatly affected by S nutrition. However, this remains to be further understood. Here, we evaluated the influence of Se treatments on broccoli (Brassica oleracea L. var. italica growth when S was withheld from the growth nutrient solution. We found that Se was highly toxic to plants when S nutrition was poor. In contrast to Se treatments with adequate S nutrition that slightly reduced broccoli growth, the same concentration of Se treatments without S supplementation dramatically reduced plant sizes. Higher Se toxicity was observed with selenate than selenite under low S nutrition. We examined the bases underlying the toxicity. We discovered that the high Se toxicity in low S nutrition was specifically associated with an increased ratio of Se in proteins verse total Se level, enhanced generation of reactive oxygen species, elevated lipid peroxidation causing increased cell membrane damage, and reduced antioxidant enzyme activities. Se toxicity could be counteracted with increased supplementation of S, which is likely through decreasing non-specific integration of Se into proteins and altering the redox system. The present study provides information for better understanding of Se toxicity and shows that adequate S nutrition is important to prevent Se toxicity during biofortification of crops by Se fertilization.

  7. Counteracting chemical chaperone effects on the single-molecule α-synuclein structural landscape

    Science.gov (United States)

    Ferreon, Allan Chris M.; Moosa, Mahdi Muhammad; Deniz, Ashok A.

    2012-01-01

    Protein structure and function depend on a close interplay between intrinsic folding energy landscapes and the chemistry of the protein environment. Osmolytes are small-molecule compounds that can act as chemical chaperones by altering the environment in a cellular context. Despite their importance, detailed studies on the role of these chemical chaperones in modulating structure and dimensions of intrinsically disordered proteins have been limited. Here, we used single-molecule Förster resonance energy transfer to test the counteraction hypothesis of counterbalancing effects between the protecting osmolyte trimethylamine-N-oxide (TMAO) and denaturing osmolyte urea for the case of α-synuclein, a Parkinson’s disease-linked protein whose monomer exhibits significant disorder. The single-molecule experiments, which avoid complications from protein aggregation, do not exhibit clear solvent-induced cooperative protein transitions for these osmolytes, unlike results from previous studies on globular proteins. Our data demonstrate the ability of TMAO and urea to shift α-synuclein structures towards either more compact or expanded average dimensions. Strikingly, the experiments directly reveal that a 2∶1 [urea]∶[TMAO] ratio has a net neutral effect on the protein’s dimensions, a result that holds regardless of the absolute osmolyte concentrations. Our findings shed light on a surprisingly simple aspect of the interplay between urea and TMAO on α-synuclein in the context of intrinsically disordered proteins, with potential implications for the biological roles of such chemical chaperones. The results also highlight the strengths of single-molecule experiments in directly probing the chemical physics of protein structure and disorder in more chemically complex environments. PMID:22826265

  8. Exercise counteracts fatty liver disease in rats fed on fructose-rich diet

    Directory of Open Access Journals (Sweden)

    Voltarelli Fabrício A

    2010-10-01

    Full Text Available Abstract Background This study aimed to analyze the effects of exercise at the aerobic/anaerobic transition on the markers of non-alcoholic fatty liver disease (NAFLD, insulin sensitivity and the blood chemistry of rats kept on a fructose-rich diet. Methods We separated 48 Wistar rats into two groups according to diet: a control group (balanced diet AIN-93 G and a fructose-rich diet group (60% fructose. The animals were tested for maximal lactate-steady state (MLSS in order to identify the aerobic/anaerobic metabolic transition during swimming exercises at 28 and 90 days of age. One third of the animals of each group were submitted to swimming training at an intensity equivalent to the individual MLSS for 1 hours/day, 5 days/week from 28 to 120 days (early protocol. Another third were submitted to the training from 90 to 120 days (late protocol, and the others remained sedentary. The main assays performed included an insulin tolerance test (ITT and tests of serum alanine aminotransferase [ALT] and aspartate aminotransferase [AST] activities, serum triglyceride concentrations [TG] and liver total lipid concentrations. Results The fructose-fed rats showed decreased insulin sensitivity, and the late-exercise training protocol counteracted this alteration. There was no difference between the groups in levels of serum ALT, whereas AST and liver lipids increased in the fructose-fed sedentary group when compared with the other groups. Serum triglycerides concentrations were higher in the fructose-fed trained groups when compared with the corresponding control group. Conclusions The late-training protocol was effective in restoring insulin sensitivity to acceptable standards. Considering the markers here evaluated, both training protocols were successful in preventing the emergence of non-alcoholic fatty liver status disease.

  9. Quantum system under the actions of two counteracting baths: A model for the attenuation-amplification interplay

    International Nuclear Information System (INIS)

    Lorenzen, F.; Moussa, M. H. Y.; Ponte, M. A. de; Almeida, N. G. de

    2009-01-01

    We analyze the dynamical behavior of a quantum system under the actions of two counteracting baths: the inevitable energy draining reservoir and, in opposition, exciting the system, an engineered Glauber's amplifier. We follow the system dynamics towards equilibrium to map its distinctive behavior arising from the interplay of attenuation and amplification. Such a mapping, with the corresponding parameter regimes, is achieved by calculating the evolution of both the excitation and the Glauber-Sudarshan P function. Techniques to compute the decoherence and the fidelity of quantum states under the action of both counteracting baths, based on the Wigner function rather than the density matrix, are also presented. They enable us to analyze the similarity of the evolved state vector of the system with respect to the original one, for all regimes of parameters. Applications of this attenuation-amplification interplay are discussed.

  10. Action plan to counteract soil acidification and to promote sustainable use of forest land

    International Nuclear Information System (INIS)

    2002-04-01

    This report consists of the National Board of Forestry's proposals on a plan to counteract soil acidification and to promote sustainable use of forest land. In 1989 the government requested the National Board of Forestry to start experimental activities to find measures to counteract soil acidification. In 1997 the Board presented a proposal for liming and vitalisation of forest land. An Environmental Impact Assessment of the proposal was submitted in 1999, after which a revision of the plan was started. In order to obtain better basic knowledge of the situation, the Board of Forestry commissioned nine reports that dealt with different aspects of soil acidification and corrective measures. Major emphasis has also been placed on the national environmental quality goals and the national plan for liming of lakes and waterways. The report is divided into three parts. The first part explains the Board of Forestry's proposals on measures to counteract soil acidification, and the second part, the description of the situation today, presents the conditions for the design of the plan such as political goals and guidelines that affect the plan and its design, the knowledge available today on soil acidification, its effects, possibilities for recovery, and possible measures that can be used. The third and final part contains brief summaries of the responses to the plan when circulated for comments. The action plan allows a return of the buffering capacity of the most acidified forest land, mainly in southern and southwestern Sweden. The Board of Forestry proposes that the spreading of ashes and lime is done within drainage areas where the natural recovery is assessed to be slow and insufficient, and where the leaching of toxic aluminium from forest land is hazardous to the aquatic ecosystem. In the assessments made by the Board, between 200,000 and 350,000 hectares of forest land may require measures of this kind. The Board of Forestry is of the opinion that a three

  11. Gamma-ray induced DNA breaks and repair studied by immuno-labelling of poly(ADP-ribose) polymerase (PARP) in chinese hamster ovary cells (CHO)

    International Nuclear Information System (INIS)

    Bidon, N.; Noel, G.; Averbeck, D.; Varlet, P.; Salamero, J.; DeMurcia, G.

    1998-01-01

    The poly(ADP-ribose)polymerase is a nuclear ubiquitous enzyme capable of binding to DNA breaks. Chinese hamster ovary cells were (CHO-K1) cultured on slides and γ-irradiated ( 137 Cs) at a high (12.8 Gy/min) or medium dose rate (5 Gy/min), and immuno-labelling against (ADP-ribose) polymers immediately or three hours after irradiation. Quantification and localisation of γ-ray induced breaks was performed by confocal microscopy. The results show a dose effect relationship, a dose-rate effect and the signal disappearance after 3 hours at 37 deg.C. The presence of PARP activity appears to reflect γ-rays induced DNA fragmentation. (authors)

  12. Modulation of Stem Cell Differentiation and Myostatin as an Approach to Counteract Fibrosis in Muscle Dystrophy and Regeneration after Injury

    Science.gov (United States)

    2011-03-01

    Duchenne muscular dystrophy (DMD). To examine whether counteracting myostatin, a negative regulator of muscle mass and a pro-lipofibrotic factor...extracellular matrix, and fat, characterizes muscle dystrophy , and in particular Duchenne muscular dystrophy (DMD) (1,2), as seen also in its animal model...stem cells (MDSC) into myogenic as opposed to lipofibrogenic lineages is a promising therapeutic strategy for Duchenne muscular dystrophy (DMD). To

  13. Counteraction of urea-induced protein denaturation by trimethylamine N-oxide: A chemical chaperone at atomic resolution

    OpenAIRE

    Bennion, Brian J.; Daggett, Valerie

    2004-01-01

    Proteins are very sensitive to their solvent environments. Urea is a common chemical denaturant of proteins, yet some animals contain high concentrations of urea. These animals have evolved an interesting mechanism to counteract the effects of urea by using trimethylamine N-oxide (TMAO). The molecular basis for the ability of TMAO to act as a chemical chaperone remains unknown. Here, we describe molecular dynamics simulations of a small globular protein, chymotrypsin inhibitor 2, in 8 M urea ...

  14. Success Counteracting Tobacco Company Interference in Thailand: An Example of FCTC Implementation for Low- and Middle-income Countries

    Directory of Open Access Journals (Sweden)

    Stephen L. Hamann

    2012-03-01

    Full Text Available Transnational tobacco companies (TTCs interfere regularly in policymaking in low- and middle-income countries (LMICs. The WHO Framework Convention for Tobacco Control provides mechanisms and guidance for dealing with TTC interference, but many countries still face ‘how to’ challenges of implementation. For more than two decades, Thailand’s public health community has been developing a system for identifying and counteracting strategies TTCs use to derail, delay and undermine tobacco control policymaking. Consequently, Thailand has already implemented most of the FCTC guidelines for counteracting TTC interference. In this study, our aims are to describe strategies TTCs have used in Thailand to interfere in policymaking, and to examine how the public health community in Thailand has counteracted TTC interference. We analyzed information reported by three groups with a stake in tobacco control policies: Thai tobacco control advocates, TTCs, and international tobacco control experts. To identify TTC viewpoints and strategies, we also extracted information from internal tobacco industry documents. We synthesized these data and identified six core strategies TTCs use to interfere in tobacco control policymaking: (1 doing business with ‘two faces’, (2 seeking to influence people in high places, (3 ‘buying’ advocates in grassroots organizations, (4 putting up a deceptive front, (5 intimidation, and (6 undermining controls on tobacco advertising, promotion and sponsorship. We present three case examples showing where TTCs have employed multiple interference strategies simultaneously, and showing how Thai tobacco control advocates have successfully counteracted those strategies by: (1 conducting vigilant surveillance, (2 excluding tobacco companies from policymaking, (3 restricting tobacco company sales, (4 sustaining pressure, and (5 dedicating resources to the effective enforcement of regulations. Policy implications from this study are

  15. Announced reward counteracts the effects of chronic social stress on anticipatory behavior and hippocampal synaptic plasticity in rats.

    Science.gov (United States)

    Kamal, Amer; Van der Harst, Johanneke E; Kapteijn, Chantal M; Baars, Annemarie J M; Spruijt, Berry M; Ramakers, Geert M J

    2010-04-01

    Chronic stress causes insensitivity to rewards (anhedonia) in rats, reflected by the absence of anticipatory behavior for a sucrose-reward, which can be reversed by antidepressant treatment or repeated announced transfer to an enriched cage. It was, however, not clear whether the highly rewarding properties of the enriched cage alone caused this reversal or whether the anticipation of this reward as such had an additional effect. Therefore, the present study compared the consequences of the announcement of a reward to the mere effect of a reward alone with respect to their efficacy to counteract the consequences of chronic stress. Two forms of synaptic plasticity, long-term potentiation and long-term depression were investigated in area CA1 of the hippocampus. This was done in socially stressed rats (induced by defeat and subsequent long-term individual housing), socially stressed rats that received a reward (short-term enriched housing) and socially stressed rats to which this reward was announced by means of a stimulus that was repeatedly paired to the reward. The results were compared to corresponding control rats. We show that announcement of enriched housing appeared to have had an additional effect compared to the enriched housing per se as indicated by a significant higher amount of LTP. In conclusion, announced short-term enriched housing has a high and long-lasting counteracting efficacy on stress-induced alterations of hippocampal synaptic plasticity. This information is important for counteracting the consequences of chronic stress in both human and captive rats.

  16. Caspase-1 Deficiency Alleviates Dopaminergic Neuronal Death via Inhibiting Caspase-7/AIF Pathway in MPTP/p Mouse Model of Parkinson's Disease.

    Science.gov (United States)

    Qiao, Chen; Zhang, Lin-Xia; Sun, Xi-Yang; Ding, Jian-Hua; Lu, Ming; Hu, Gang

    2017-08-01

    Caspase family has been recognized to be involved in dopaminergic (DA) neuronal death and to exert an unfavorable role in Parkinson's disease (PD) pathology. Our previous study has revealed that caspase-1, as an important component of NLRP3 inflammasome, induces microglia-mediated neuroinflammation in the pathogenesis of PD. However, the role of caspase-1 in DA neuronal degeneration in the onset of PD remains unclear. Here, we showed that caspase-1 knockout ameliorated DA neuronal loss and dyskinesia in 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine/probenecid (MPTP/p)-induced PD model mice. We further found that caspase-1 knockout decreased MPTP/p-induced caspase-7 cleavage, subsequently inhibited nuclear translocation of poly (ADP-ribose) polymerase 1 (PARP1), and reduced the release of apoptosis-inducing factor (AIF). Consistently, we demonstrated that caspase-1 inhibitor suppressed caspase-7/PARP1/AIF-mediated apoptosis pathway by 1-methyl-4-phenylpyridinium ion (MPP + ) stimulation in SH-SY5Y cells. Caspase-7 overexpression reduced the protective effects of caspase-1 inhibitor on SH-SY5Y cell apoptosis. Collectively, our results have revealed that caspase-1 regulates DA neuronal death in the pathogenesis of PD in mice via caspase-7/PARP1/AIF pathway. These findings will shed new insight into the potential of caspase-1 as a target for PD therapy.

  17. AAV-mediated pancreatic overexpression of Igf1 counteracts progression to autoimmune diabetes in mice.

    Science.gov (United States)

    Mallol, Cristina; Casana, Estefania; Jimenez, Veronica; Casellas, Alba; Haurigot, Virginia; Jambrina, Claudia; Sacristan, Victor; Morró, Meritxell; Agudo, Judith; Vilà, Laia; Bosch, Fatima

    2017-07-01

    Type 1 diabetes is characterized by autoimmune destruction of β-cells leading to severe insulin deficiency. Although many improvements have been made in recent years, exogenous insulin therapy is still imperfect; new therapeutic approaches, focusing on preserving/expanding β-cell mass and/or blocking the autoimmune process that destroys islets, should be developed. The main objective of this work was to test in non-obese diabetic (NOD) mice, which spontaneously develop autoimmune diabetes, the effects of local expression of Insulin-like growth factor 1 (IGF1), a potent mitogenic and pro-survival factor for β-cells with immunomodulatory properties. Transgenic NOD mice overexpressing IGF1 specifically in β-cells (NOD-IGF1) were generated and phenotyped. In addition, miRT-containing, IGF1-encoding adeno-associated viruses (AAV) of serotype 8 (AAV8-IGF1-dmiRT) were produced and administered to 4- or 11-week-old non-transgenic NOD females through intraductal delivery. Several histological, immunological, and metabolic parameters were measured to monitor disease over a period of 28-30 weeks. In transgenic mice, local IGF1 expression led to long-term suppression of diabetes onset and robust protection of β-cell mass from the autoimmune insult. AAV-mediated pancreatic-specific overexpression of IGF1 in adult animals also dramatically reduced diabetes incidence, both when vectors were delivered before pathology onset or once insulitis was established. Transgenic NOD-IGF1 and AAV8-IGF1-dmiRT-treated NOD animals had much less islet infiltration than controls, preserved β-cell mass, and normal insulinemia. Transgenic and AAV-treated islets showed less expression of antigen-presenting molecules, inflammatory cytokines, and chemokines important for tissue-specific homing of effector T cells, suggesting IGF1 modulated islet autoimmunity in NOD mice. Local expression of Igf1 by AAV-mediated gene transfer counteracts progression to diabetes in NOD mice. This study suggests a

  18. Gc-protein-derived macrophage activating factor counteracts the neuronal damage induced by oxaliplatin.

    Science.gov (United States)

    Morucci, Gabriele; Branca, Jacopo J V; Gulisano, Massimo; Ruggiero, Marco; Paternostro, Ferdinando; Pacini, Alessandra; Di Cesare Mannelli, Lorenzo; Pacini, Stefania

    2015-02-01

    Oxaliplatin-based regimens are effective in metastasized advanced cancers. However, a major limitation to their widespread use is represented by neurotoxicity that leads to peripheral neuropathy. In this study we evaluated the roles of a proven immunotherapeutic agent [Gc-protein-derived macrophage activating factor (GcMAF)] in preventing or decreasing oxaliplatin-induced neuronal damage and in modulating microglia activation following oxaliplatin-induced damage. The effects of oxaliplatin and of a commercially available formula of GcMAF [oleic acid-GcMAF (OA-GcMAF)] were studied in human neurons (SH-SY5Y cells) and in human microglial cells (C13NJ). Cell density, morphology and viability, as well as production of cAMP and expression of vascular endothelial growth factor (VEGF), markers of neuron regeneration [neuromodulin or growth associated protein-43 (Gap-43)] and markers of microglia activation [ionized calcium binding adaptor molecule 1 (Iba1) and B7-2], were determined. OA-GcMAF reverted the damage inflicted by oxaliplatin on human neurons and preserved their viability. The neuroprotective effect was accompanied by increased intracellular cAMP production, as well as by increased expression of VEGF and neuromodulin. OA-GcMAF did not revert the effects of oxaliplatin on microglial cell viability. However, it increased microglial activation following oxaliplatin-induced damage, resulting in an increased expression of the markers Iba1 and B7-2 without any concomitant increase in cell number. When neurons and microglial cells were co-cultured, the presence of OA-GcMAF significantly counteracted the toxic effects of oxaliplatin. Our results demonstrate that OA-GcMAF, already used in the immunotherapy of advanced cancers, may significantly contribute to neutralizing the neurotoxicity induced by oxaliplatin, at the same time possibly concurring to an integrated anticancer effect. The association between these two powerful anticancer molecules would probably produce

  19. Mannosyl Glycodendritic Structure Inhibits DC-SIGN-Mediated Ebola Virus Infection in cis and in trans

    OpenAIRE

    Lasala, Fátima; Arce, Eva; Otero, Joaquín R.; Rojo, Javier; Delgado, Rafael

    2003-01-01

    We have designed a glycodendritic structure, BH30sucMan, that blocks the interaction between dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) and Ebola virus (EBOV) envelope. BH30sucMan inhibits DC-SIGN-mediated EBOV infection at nanomolar concentrations. BH30sucMan may counteract important steps of the infective process of EBOV and, potentially, of microorganisms shown to exploit DC-SIGN for cell entry and infection.

  20. Mannosyl Glycodendritic Structure Inhibits DC-SIGN-Mediated Ebola Virus Infection in cis and in trans

    Science.gov (United States)

    Lasala, Fátima; Arce, Eva; Otero, Joaquín R.; Rojo, Javier; Delgado, Rafael

    2003-01-01

    We have designed a glycodendritic structure, BH30sucMan, that blocks the interaction between dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) and Ebola virus (EBOV) envelope. BH30sucMan inhibits DC-SIGN-mediated EBOV infection at nanomolar concentrations. BH30sucMan may counteract important steps of the infective process of EBOV and, potentially, of microorganisms shown to exploit DC-SIGN for cell entry and infection. PMID:14638512

  1. Excessive islet NO generation in type 2 diabetic GK rats coincides with abnormal hormone secretion and is counteracted by GLP-1.

    Directory of Open Access Journals (Sweden)

    Albert Salehi

    Full Text Available BACKGROUND: A distinctive feature of type 2 diabetes is inability of insulin-secreting beta-cells to properly respond to elevated glucose eventually leading to beta-cell failure. We have hypothesized that an abnormally increased NO production in the pancreatic islets might be an important factor in the pathogenesis of beta-cell dysfunction. PRINCIPAL FINDINGS: We show now that islets of type 2 spontaneous diabetes in GK rats display excessive NO generation associated with abnormal iNOS expression in insulin and glucagon cells, increased ncNOS activity, impaired glucose-stimulated insulin release, glucagon hypersecretion, and impaired glucose-induced glucagon suppression. Pharmacological blockade of islet NO production by the NOS inhibitor N(G-nitro-L-arginine methyl ester (L-NAME greatly improved hormone secretion from GK islets suggesting islet NOS activity being an important target to inactivate for amelioration of islet cell function. The incretin hormone GLP-1, which is used in clinical practice suppressed iNOS and ncNOS expression and activity with almost full restoration of insulin release and partial restoration of glucagon release. GLP-1 suppression of iNOS expression was reversed by PKA inhibition but unaffected by the proteasome inhibitor MG132. Injection of glucose plus GLP-1 in the diabetic rats showed that GLP-1 amplified the insulin response but induced a transient increase and then a poor depression of glucagon. CONCLUSION: The results suggest that abnormally increased NO production within islet cells is a significant player in the pathogenesis of type 2 diabetes being counteracted by GLP-1 through PKA-dependent, nonproteasomal mechanisms.

  2. Improvement of the organizational support of prevention and counteraction of corruption in the bodies of State Fiscal Service of Ukraine

    Directory of Open Access Journals (Sweden)

    S. M. Ivasenko

    2014-11-01

    Full Text Available The article analyses directions of perfection of organizational support of prevention and counteraction of corruption in the bodies of State fiscal service of Ukraine. It is noted that fight against corruption in tax authorities is the most important component of increasing the efficiency of tax administration and tax crime reducing. In its importance it can be equated to such important problems as the fighting against tax crimes. The author, generalizing theoretical approaches, highlights priority activities aimed at improving the efficiency of detecting and exposing corrupt employees of the fiscal authorities.

  3. A result on the acoustic characteristics of the Mixture of Counter-phase Counteract and Split-gas Rushing muffler

    Directory of Open Access Journals (Sweden)

    Shao Ying-li

    2016-01-01

    Full Text Available The exhaust noise, which falls into low-frequency noise, is the dominant noise source of a diesel engines and tractors. The traditional exhaust silencers, which are normally constructed by combination of expansion chamber, and perforated pipe or perforated board, are with high exhaust resistance, but poor noise reduction especially for the low-frequency band noise. For this reason, a new theory of exhaust muffler of diesel engine based on counter-phase counteracts has been proposed. The mathematical model and the corresponding experimental validation for the new exhaust muffler based on this theory were performed.

  4. Hypoxic resistance of KRAS mutant tumor cells to 3-Bromopyruvate is counteracted by Prima-1 and reversed by N-acetylcysteine.

    Science.gov (United States)

    Orue, Andrea; Chavez, Valery; Strasberg-Rieber, Mary; Rieber, Manuel

    2016-11-18

    The metabolic inhibitor 3-bromopyruvate (3-BrPA) is a promising anti-cancer alkylating agent, shown to inhibit growth of some colorectal carcinoma with KRAS mutation. Recently, we demonstrated increased resistance to 3-BrPA in wt p53 tumor cells compared to those with p53 silencing or mutation. Since hypoxic microenvironments select for tumor cells with diminished therapeutic response, we investigated whether hypoxia unequally increases resistance to 3-BrPA in wt p53 MelJuso melanoma harbouring (Q61L)-mutant NRAS and wt BRAF, C8161 melanoma with (G12D)-mutant KRAS (G464E)-mutant BRAF, and A549 lung carcinoma with a KRAS (G12S)-mutation. Since hypoxia increases the toxicity of the p53 activator, Prima-1 against breast cancer cells irrespective of their p53 status, we also investigated whether Prima-1 reversed hypoxic resistance to 3-BrPA. In contrast to the high susceptibility of hypoxic mutant NRAS MelJuso cells to 3-BrPA or Prima-1, KRAS mutant C8161 and A549 cells revealed hypoxic resistance to 3-BrPA counteracted by Prima-1. In A549 cells, Prima-1 increased p21CDKN1mRNA, and reciprocally inhibited mRNA expression of the SLC2A1-GLUT1 glucose transporter-1 and ALDH1A1, gene linked to detoxification and stem cell properties. 3-BrPA lowered CAIX and VEGF mRNA expression. Death from joint Prima-1 and 3-BrPA treatment in KRAS mutant A549 and C8161 cells seemed mediated by potentiating oxidative stress, since it was antagonized by the anti-oxidant and glutathione precursor N-acetylcysteine. This report is the first to show that Prima-1 kills hypoxic wt p53 KRAS-mutant cells resistant to 3-BrPA, partly by decreasing GLUT-1 expression and exacerbating pro-oxidant stress.

  5. A Phase 1 trial of the PARP inhibitor olaparib (AZD2281) in combination with the anti-angiogenic cediranib (AZD2171) in recurrent epithelial ovarian or triple-negative breast cancer

    Science.gov (United States)

    Liu, Joyce F.; Tolaney, Sara M.; Birrer, Michael; Fleming, Gini F.; Buss, Mary K.; Dahlberg, Suzanne E.; Lee, Hang; Whalen, Christin; Tyburski, Karin; Winer, Eric; Ivy, Percy; Matulonis, Ursula A.

    2014-01-01

    Background PARP-inhibitors and anti-angiogenics have activity in recurrent ovarian and breast cancer; however, the effect of combined therapy against PARP and angiogenesis in this population has not been reported. We investigated the toxicities and recommended phase 2 dosing (RP2D) of the combination of cediranib, a multitargeted inhibitor of VEGFR-1/2/3, and olaparib, a PARP-inhibitor (NCT01116648). Methods Cediranib tablets once daily and olaparib capsules twice daily were administered orally in a standard 3+3 dose escalation design. Patients with recurrent ovarian or metastatic triple-negative breast cancer were eligible. Patients had measurable disease by RECIST 1.1 or met GCIG CA125 criteria. No prior PARP-inhibitors or anti-angiogenics in the recurrent setting were allowed. Results 28 patients (20 ovarian, 8 breast) enrolled to 4 dose levels. 2 DLTs (1 grade 4 neutropenia ≥4 days; 1 grade 4 thrombocytopenia) occurred at the highest dose level (cediranib 30mg daily; olaparib 400mg BID). The RP2D was cediranib 30mg daily and olaparib 200mg BID. Grade 3 or higher toxicities occurred in 75% of patients, and included grade 3 hypertension (25%) and grade 3 fatigue (18%). One grade 3 bowel obstruction occurred. The overall response rate (ORR) in the 18 RECIST-evaluable ovarian cancer patients was 44%, with a clinical benefit rate (ORR plus SD >24 weeks) of 61%. None of the 7 evaluable breast cancer patients achieved clinical response; 2 patients had stable disease for >24 weeks. Interpretation The combination of cediranib and olaparib has hematologic DLTs and anticipated class toxicities, with promising evidence of activity in ovarian cancer patients. PMID:23810467

  6. Smoking Counteracts the Favorable Effect of Exercise Training on Endothelial Function in Patients with Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Shinji Sato

    2013-01-01

    Full Text Available Background Exercise training can improve endothelial function in patients with diabetes. We hypothesized that the favorable effect of exercise training on endothelial function in patients with diabetes is counteracted by cigarette smoking. Purpose To assess whether there is a difference in the effect of exercise on endothelial function in smokers and non-smokers with type 2 diabetes. Methods We performed a 3-month controlled trial in 27 never-smoking and 17 smoking individuals with type 2 diabetes who participated in a home-based walking program. The percentage decrease in post-exercise ankle-brachial pressure index (ABI, which is an index of endothelial function, was assessed at baseline and after 3 months. Results Compared to the smoking group, the never-smoking group showed a more significant improvement in post exercise ABI during the 3 months of home-based training (interaction, P < 0.01. Conclusions These results indicate that smoking may counteract the favorable effects of exercise training on endothelial function. Endothelial function plays an important role in the prevention of cardiovascular disease among patients with diabetes. Therefore, a Certified Diabetes Educator should strongly advise diabetic patients not to smoke.

  7. Counteraction of urea-induced protein denaturation by trimethylamine N-oxide: a chemical chaperone at atomic resolution.

    Science.gov (United States)

    Bennion, Brian J; Daggett, Valerie

    2004-04-27

    Proteins are very sensitive to their solvent environments. Urea is a common chemical denaturant of proteins, yet some animals contain high concentrations of urea. These animals have evolved an interesting mechanism to counteract the effects of urea by using trimethylamine N-oxide (TMAO). The molecular basis for the ability of TMAO to act as a chemical chaperone remains unknown. Here, we describe molecular dynamics simulations of a small globular protein, chymotrypsin inhibitor 2, in 8 M urea and 4 M TMAO/8 M urea solutions, in addition to other control simulations, to investigate this effect at the atomic level. In 8 M urea, the protein unfolds, and urea acts in both a direct and indirect manner to achieve this effect. In contrast, introduction of 4 M TMAO counteracts the effect of urea and the protein remains well structured. TMAO makes few direct interactions with the protein. Instead, it prevents unfolding of the protein by structuring the solvent. In particular, TMAO orders the solvent and discourages it from competing with intraprotein H bonds and breaking up the hydrophobic core of the protein.

  8. JNK Phosphorylates SIRT6 to Stimulate DNA Double-Strand Break Repair in Response to Oxidative Stress by Recruiting PARP1 to DNA Breaks

    Directory of Open Access Journals (Sweden)

    Michael Van Meter

    2016-09-01

    Full Text Available The accumulation of damage caused by oxidative stress has been linked to aging and to the etiology of numerous age-related diseases. The longevity gene, sirtuin 6 (SIRT6, promotes genome stability by facilitating DNA repair, especially under oxidative stress conditions. Here we uncover the mechanism by which SIRT6 is activated by oxidative stress to promote DNA double-strand break (DSB repair. We show that the stress-activated protein kinase, c-Jun N-terminal kinase (JNK, phosphorylates SIRT6 on serine 10 in response to oxidative stress. This post-translational modification facilitates the mobilization of SIRT6 to DNA damage sites and is required for efficient recruitment of poly (ADP-ribose polymerase 1 (PARP1 to DNA break sites and for efficient repair of DSBs. Our results demonstrate a post-translational mechanism regulating SIRT6, and they provide the link between oxidative stress signaling and DNA repair pathways that may be critical for hormetic response and longevity assurance.

  9. Astragaloside IV attenuates experimental autoimmune encephalomyelitis of mice by counteracting oxidative stress at multiple levels.

    Directory of Open Access Journals (Sweden)

    Yixin He

    Full Text Available Multiple sclerosis (MS is a chronic autoimmune neuroinflammatory disease found mostly in young adults in the western world. Oxidative stress induced neuronal apoptosis plays an important role in the pathogenesis of MS. In current study, astragaloside IV (ASI, a natural saponin molecule isolated from Astragalus membranceus, given at 20 mg/kg daily attenuated the severity of experimental autoimmune encephalomyelitis (EAE in mice significantly. Further studies disclosed that ASI treatment inhibited the increase of ROS and pro-inflammatory cytokine levels, down-regulation of SOD and GSH-Px activities, and elevation of iNOS, p53 and phosphorylated tau in central nervous system (CNS as well as the leakage of BBB of EAE mice. Meanwhile, the decreased ratio of Bcl-2/Bax was reversed by ASI. Moreover, ASI regulated T-cell differentiation and infiltration into CNS. In neuroblast SH-SY5Y cells, ASI dose-dependently reduced cellular ROS level and phosphorylation of tau in response to hydrogen peroxide challenge by modulation of Bcl-2/Bax ratio. ASI also inhibited activation of microglia both in vivo and in vitro. iNOS up-regulation induced by IFNγ stimulation was abolished by ASI dose-dependently in BV-2 cells. In summary, ASI prevented the severity of EAE progression possibly by counterbalancing oxidative stress and its effects via reduction of cellular ROS level, enhancement of antioxidant defense system, increase of anti-apoptotic and anti-inflammatory pathways, as well as modulation of T-cell differentiation and infiltration into CNS. The study suggested ASI may be effective for clinical therapy/prevention of MS.

  10. Astragaloside IV attenuates experimental autoimmune encephalomyelitis of mice by counteracting oxidative stress at multiple levels.

    Science.gov (United States)

    He, Yixin; Du, Min; Gao, Yan; Liu, Hongshuai; Wang, Hongwei; Wu, Xiaojun; Wang, Zhengtao

    2013-01-01

    Multiple sclerosis (MS) is a chronic autoimmune neuroinflammatory disease found mostly in young adults in the western world. Oxidative stress induced neuronal apoptosis plays an important role in the pathogenesis of MS. In current study, astragaloside IV (ASI), a natural saponin molecule isolated from Astragalus membranceus, given at 20 mg/kg daily attenuated the severity of experimental autoimmune encephalomyelitis (EAE) in mice significantly. Further studies disclosed that ASI treatment inhibited the increase of ROS and pro-inflammatory cytokine levels, down-regulation of SOD and GSH-Px activities, and elevation of iNOS, p53 and phosphorylated tau in central nervous system (CNS) as well as the leakage of BBB of EAE mice. Meanwhile, the decreased ratio of Bcl-2/Bax was reversed by ASI. Moreover, ASI regulated T-cell differentiation and infiltration into CNS. In neuroblast SH-SY5Y cells, ASI dose-dependently reduced cellular ROS level and phosphorylation of tau in response to hydrogen peroxide challenge by modulation of Bcl-2/Bax ratio. ASI also inhibited activation of microglia both in vivo and in vitro. iNOS up-regulation induced by IFNγ stimulation was abolished by ASI dose-dependently in BV-2 cells. In summary, ASI prevented the severity of EAE progression possibly by counterbalancing oxidative stress and its effects via reduction of cellular ROS level, enhancement of antioxidant defense system, increase of anti-apoptotic and anti-inflammatory pathways, as well as modulation of T-cell differentiation and infiltration into CNS. The study suggested ASI may be effective for clinical therapy/prevention of MS.

  11. Response inhibition under alcohol: effects of cognitive and motivational conflict.

    Science.gov (United States)

    Fillmore, M T; Vogel-Sprott, M

    2000-03-01

    This experiment tested the effect of cognitive and motivational conflict on response inhibition under alcohol. Fifty-six male social drinkers were randomly assigned to one of eight groups (n = 8). Four pairs of groups received 0.62 g/kg of alcohol, or a placebo, and each pair performed a go/stop choice reaction time task under one of four conflict conditions. One condition (C) produced cognitive conflict by presenting "go" and "stop" signals in the task. Another condition (IR) added motivational conflict by administering an equal monetary reward for inhibiting responses to stop-signals, and for responding to go-signals. The remaining two conditions resolved the motivational conflict by administering the monetary reward only for inhibitions (I), or only for responses (R). Compared with placebo, alcohol reduced inhibitions (i.e., impaired inhibitory control) under cognitive conflict (C; p = .041) and under motivational conflict (IR; p = .012). No significant effect of alcohol on inhibitions was observed in conditions where conflict was resolved (i.e., I and R). The study shows that alcohol can reduce the ability to inhibit a response. However, impaired inhibitory control is not an inevitable outcome of the drug action, because it can be counteracted by the consequences of behavior in the situation.

  12. Novel derivative of aminobenzenesulfonamide (3c) induces apoptosis in colorectal cancer cells through ROS generation and inhibits cell migration.

    Science.gov (United States)

    Al-Khayal, Khayal; Alafeefy, Ahmed; Vaali-Mohammed, Mansoor-Ali; Mahmood, Amer; Zubaidi, Ahmed; Al-Obeed, Omar; Khan, Zahid; Abdulla, Maha; Ahmad, Rehan

    2017-01-03

    Colorectal cancer (CRC) is the 3 rd most common type of cancer worldwide. New anti-cancer agents are needed for treating late stage colorectal cancer as most of the deaths occur due to cancer metastasis. A recently developed compound, 3c has shown to have potent antitumor effect; however the mechanism underlying the antitumor effect remains unknown. 3c-induced inhibition of proliferation was measured in the absence and presence NAC using MTT in HT-29 and SW620 cells and xCELLigence RTCA DP instrument. 3c-induced apoptotic studies were performed using flow cytometry. 3c-induced redox alterations were measured by ROS production using fluorescence plate reader and flow cytometry and mitochondrial membrane potential by flow cytometry; NADPH and GSH levels were determined by colorimetric assays. Bcl2 family protein expression and cytochrome c release and PARP activation was done by western blotting. Caspase activation was measured by ELISA. Cell migration assay was done using the real time xCELLigence RTCA DP system in SW620 cells and wound healing assay in HT-29. Many anticancer therapeutics exert their effects by inducing reactive oxygen species (ROS). In this study, we demonstrate that 3c-induced inhibition of cell proliferation is reversed by the antioxidant, N-acetylcysteine, suggesting that 3c acts via increased production of ROS in HT-29 cells. This was confirmed by the direct measurement of ROS in 3c-treated colorectal cancer cells. Additionally, treatment with 3c resulted in decreased NADPH and glutathione levels in HT-29 cells. Further, investigation of the apoptotic pathway showed increased release of cytochrome c resulting in the activation of caspase-9, which in turn activated caspase-3 and -6. 3c also (i) increased p53 and Bax expression, (ii) decreased Bcl2 and BclxL expression and (iii) induced PARP cleavage in human colorectal cancer cells. Confirming our observations, NAC significantly inhibited induction of apoptosis, ROS production, cytochrome c

  13. Forms of the criminal environment counteraction to performing the function of state protection of participants in criminal proceedings and measures of its neutralization

    Directory of Open Access Journals (Sweden)

    Dubonosov E.S.

    2014-12-01

    Full Text Available Criminal environment’s counteraction is considered as purposeful, active and intentional influence of its representatives on participants in criminal proceedings. It is directed at persons who, due to their professional duties, are involved in detection and investigation of crimes as well as court proceedings, or who possess evidentiary information (witnesses, victims, etc.. Counteraction may be expressed in different ways: discrediting operatives, investigators and judges; pressure on persons involved in the investigation and the trial through bribery, blackmail, threats to life and health of themselves and their family, etc. The administration of justice becomes inefficient due to the variety of forms and purposes of counteraction. The importance of operational units’ awareness of the activities of criminal environment representatives is shown. The importance of revealing the facts of unlawful influence on witnesses and victims of crime, who subsequently acquire procedural status of witnesses and victims, in order to prevent such facts is also stressed. It is proposed to suppress the counteraction of criminal environment by following ways: 1 identifying (with the help of informants and by crime detection actions the persons attempting to influence the preliminary investigation; 2 documenting the suspects actions aimed at illegal influence on participants in criminal proceedings for the purpose of conducting the procedural actions and decision making; 3 “in cell” (using an agent crime detection actions against detainees and arrestees throughout the whole process of covert operation; 4 creating investigative team to develop a common mechanism to neutralize criminal environment’s counteraction to crime investigation.

  14. Targeting the Epidermal Growth Factor Receptor Can Counteract the Inhibition of Natural Killer Cell Function Exerted by Colorectal Tumor-Associated Fibroblasts

    Directory of Open Access Journals (Sweden)

    Delfina Costa

    2018-05-01

    Full Text Available Mesenchymal stromal cells (MSC present in the tumor microenvironment [usually named tumor-associated fibroblasts (TAF] can exert immunosuppressive effects on T and natural killer (NK lymphocytes, favoring tumor immune escape. We have analyzed this mechanism in colorectal carcinoma (CRC and found that co-culture of NK cells with TAF can prevent the IL-2-mediated NKG2D upregulation. This leads to the impairment of NKG2D-mediated recognition of CRC cells, sparing the NK cell activation through DNAM1 or FcγRIIIA (CD16. In situ, TAF express detectable levels of epidermal growth factor receptor (EGFR; thus, the therapeutic anti-EGFR humanized antibody cetuximab can trigger the antibody-dependent cellular cytotoxicity of TAF, through the engagement of FcγRIIIA on NK cells. Importantly, in the tumor, we found a lymphoid infiltrate containing NKp46+CD3− NK cells, enriched in CD16+ cells. This population, sorted and cultured with IL-2, could be triggered via CD16 and via NKG2D. Of note, ex vivo NKp46+CD3− cells were able to kill autologous TAF; in vivo, this might represent a control mechanism to reduce TAF-mediated regulatory effect on NK cell function. Altogether, these findings suggest that MSC from the neoplastic mucosa (TAF of CRC patients can downregulate the immune cell recognition of CRC tumor cells. This immunosuppression can be relieved by the anti-EGFR antibody used in CRC immunotherapy.

  15. Targeting the Epidermal Growth Factor Receptor Can Counteract the Inhibition of Natural Killer Cell Function Exerted by Colorectal Tumor-Associated Fibroblasts

    Science.gov (United States)

    Costa, Delfina; Venè, Roberta; Benelli, Roberto; Romairone, Emanuele; Scabini, Stefano; Catellani, Silvia; Rebesco, Barbara; Mastracci, Luca; Grillo, Federica; Minghelli, Simona; Loiacono, Fabrizio; Zocchi, Maria Raffaella; Poggi, Alessandro

    2018-01-01

    Mesenchymal stromal cells (MSC) present in the tumor microenvironment [usually named tumor-associated fibroblasts (TAF)] can exert immunosuppressive effects on T and natural killer (NK) lymphocytes, favoring tumor immune escape. We have analyzed this mechanism in colorectal carcinoma (CRC) and found that co-culture of NK cells with TAF can prevent the IL-2-mediated NKG2D upregulation. This leads to the impairment of NKG2D-mediated recognition of CRC cells, sparing the NK cell activation through DNAM1 or FcγRIIIA (CD16). In situ, TAF express detectable levels of epidermal growth factor receptor (EGFR); thus, the therapeutic anti-EGFR humanized antibody cetuximab can trigger the antibody-dependent cellular cytotoxicity of TAF, through the engagement of FcγRIIIA on NK cells. Importantly, in the tumor, we found a lymphoid infiltrate containing NKp46+CD3− NK cells, enriched in CD16+ cells. This population, sorted and cultured with IL-2, could be triggered via CD16 and via NKG2D. Of note, ex vivo NKp46+CD3− cells were able to kill autologous TAF; in vivo, this might represent a control mechanism to reduce TAF-mediated regulatory effect on NK cell function. Altogether, these findings suggest that MSC from the neoplastic mucosa (TAF) of CRC patients can downregulate the immune cell recognition of CRC tumor cells. This immunosuppression can be relieved by the anti-EGFR antibody used in CRC immunotherapy. PMID:29910806

  16. The pro-fibrotic properties of transforming growth factor on human fibroblasts are counteracted by caffeic acid by inhibiting myofibroblast formation and collagen synthesis

    NARCIS (Netherlands)

    Mia, Masum M.; Bank, Ruud A.

    Fibrosis is a chronic disorder affecting many organs. A universal process in fibrosis is the formation of myofibroblasts and the subsequent collagen deposition by these cells. Transforming growth factor beta1 (TGF beta 1) plays a major role in the formation of myofibroblasts, e.g. by activating

  17. Cigarette smoke extract counteracts atheroprotective effects of high laminar flow on endothelial function

    Directory of Open Access Journals (Sweden)

    Sindy Giebe

    2017-08-01

    Full Text Available Tobacco smoking and hemodynamic forces are key stimuli in the development of endothelial dysfunction and atherosclerosis. High laminar flow has an atheroprotective effect on the endothelium and leads to a reduced response of endothelial cells to cardiovascular risk factors compared to regions with disturbed or low laminar flow. We hypothesize that the atheroprotective effect of high laminar flow could delay the development of endothelial dysfunction caused by cigarette smoking. Primary human endothelial cells were stimulated with increasing dosages of aqueous cigarette smoke extract (CSEaq. CSEaq reduced cell viability in a dose-dependent manner. The main mediator of cellular adaption to oxidative stress, nuclear factor erythroid 2-related factor 2 (NRF2 and its target genes heme oxygenase (decycling 1 (HMOX1 or NAD(PH quinone dehydrogenase 1 (NQO1 were strongly increased by CSEaq in a dose-dependent manner. High laminar flow induced elongation of endothelial cells in the direction of flow, activated the AKT/eNOS pathway, increased eNOS expression, phosphorylation and NO release. These increases were inhibited by CSEaq. Pro-inflammatory adhesion molecules intercellular adhesion molecule-1 (ICAM1, vascular cell adhesion molecule-1 (VCAM1, selectin E (SELE and chemokine (C-C motif ligand 2 (CCL2/MCP-1 were increased by CSEaq. Low laminar flow induced VCAM1 and SELE compared to high laminar flow. High laminar flow improved endothelial wound healing. This protective effect was inhibited by CSEaq in a dose-dependent manner through the AKT/eNOS pathway. Low as well as high laminar flow decreased adhesion of monocytes to endothelial cells. Whereas, monocyte adhesion was increased by CSEaq under low laminar flow, this was not evident under high laminar flow.This study shows the activation of major atherosclerotic key parameters by CSEaq. Within this process, high laminar flow is likely to reduce the harmful effects of CSEaq to a certain degree. The

  18. CIRCADIAN CLOCK-ASSOCIATED 1 Inhibits Leaf Senescence in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Yi Song

    2018-03-01

    Full Text Available Leaf senescence is an integral part of plant development, and the timing and progressing rate of senescence could substantially affect the yield and quality of crops. It has been known that a circadian rhythm synchronized with external environmental cues is critical for the optimal coordination of various physiological and metabolic processes. However, the reciprocal interactions between the circadian clock and leaf senescence in plants remain unknown. Here, through measuring the physiological and molecular senescence related markers of several circadian components mutants, we found that CIRCADIAN CLOCK-ASSOCIATED 1 inhibits leaf senescence. Further molecular and genetic studies revealed that CCA1 directly activates GLK2 and suppresses ORE1 expression to counteract leaf senescence. As plants age, the expression and periodic amplitude of CCA1 declines and thus weakens the inhibition of senescence. Our findings reveal an age-dependent circadian clock component of the process of leaf senescence.

  19. Renewable Energy Production from Waste to Mitigate Climate Change and Counteract Soil Degradation - A Spatial Explicit Assessment for Japan

    Science.gov (United States)

    Kraxner, Florian; Yoshikawa, Kunio; Leduc, Sylvain; Fuss, Sabine; Aoki, Kentaro; Yamagata, Yoshiki

    2014-05-01

    Waste production from urban areas is growing faster than urbanization itself, while at the same time urban areas are increasingly contributing substantial emissions causing climate change. Estimates indicate for urban residents a per capita solid waste (MSW) production of 1.2 kg per day, subject to further increase to 1.5 kg beyond 2025. Waste water and sewage production is estimated at about 260 liters per capita and day, also at increasing rates. Based on these figures, waste - including e.g. MSW, sewage and animal manure - can generally be assumed as a renewable resource with varying organic components and quantity. This paper demonstrates how new and innovative technologies in the field of Waste-to-Green Products can help in various ways not only to reduce costs for waste treatment, reduce the pressure on largely overloaded dump sites, and reduce also the effect of toxic materials at the landfill site and by that i.e. protect the groundwater. Moreover, Waste-to-Green Products can contribute actively to mitigating climate change through fossil fuel substitution and carbon sequestration while at the same time counteracting negative land use effects from other types of renewable energy and feedstock production through substitution. At the same time, the co-production and recycling of fertilizing elements and biochar can substantially counteract soil degradation and improve the soil organic carbon content of different land use types. The overall objective of this paper is to assess the total climate change mitigation potential of MSW, sewage and animal manure for Japan. A techno-economic approach is used to inform the policy discussion on the suitability of this substantial and sustainable mitigation option. We examine the spatial explicit technical mitigation potential from e.g. energy substitution and carbon sequestration through biochar in rural and urban Japan. For this exercise, processed information on respective Japanese waste production, energy demand

  20. The helicase domain of Polθ counteracts RPA to promote alt-NHEJ.

    Science.gov (United States)

    Mateos-Gomez, Pedro A; Kent, Tatiana; Deng, Sarah K; McDevitt, Shane; Kashkina, Ekaterina; Hoang, Trung M; Pomerantz, Richard T; Sfeir, Agnel

    2017-12-01

    Mammalian polymerase theta (Polθ) is a multifunctional enzyme that promotes error-prone DNA repair by alternative nonhomologous end joining (alt-NHEJ). Here we present structure-function analyses that reveal that, in addition to the polymerase domain, Polθ-helicase activity plays a central role during double-strand break (DSB) repair. Our results show that the helicase domain promotes chromosomal translocations by alt-NHEJ in mouse embryonic stem cells and also suppresses CRISPR-Cas9- mediated gene targeting by homologous recombination (HR). In vitro assays demonstrate that Polθ-helicase activity facilitates the removal of RPA from resected DSBs to allow their annealing and subsequent joining by alt-NHEJ. Consistent with an antagonistic role for RPA during alt-NHEJ, inhibition of RPA1 enhances end joining and suppresses recombination. Taken together, our results reveal that the balance between HR and alt-NHEJ is controlled by opposing activities of Polθ and RPA, providing further insight into the regulation of repair-pathway choice in mammalian cells.

  1. Prion diseases and adult neurogenesis: how do prions counteract the brain's endogenous repair machinery?

    Science.gov (United States)

    Relaño-Ginés, Aroa; Lehmann, Sylvain; Crozet, Carole

    2014-01-01

    Scientific advances in stem cell biology and adult neurogenesis have raised the hope that neurodegenerative disorders could benefit from stem cell-based therapy. Adult neurogenesis might be part of the physiological regenerative process, however it might become impaired by the disease's mechanism and therefore contribute to neurodegeneration. In prion disorders this endogenous repair system has rarely been studied. Whether adult neurogenesis plays a role or not in brain repair or in the propagation of prion pathology remains unclear. We have recently investigated the status of adult neural stem cells isolated from prion-infected mice. We were able to show that neural stem cells accumulate and replicate prions thus resulting in an alteration of their neuronal destiny. We also reproduced these results in adult neural stem cells, which were infected in vitro. The fact that endogenous adult neurogenesis could be altered by the accumulation of misfolded prion protein represents another great challenge. Inhibiting prion propagation in these cells would thus help the endogenous neurogenesis to compensate for the injured neuronal system. Moreover, understanding the endogenous modulation of the neurogenesis system would help develop effective neural stem cell-based therapies.

  2. Modulation of radiation response by histone deacetylase inhibition

    International Nuclear Information System (INIS)

    Chinnaiyan, Prakash; Vallabhaneni, Geetha; Armstrong, Eric M.S.; Huang, Shyh-Min; Harari, Paul M.

    2005-01-01

    Purpose: Histone deacetylase (HDAC) inhibitors, which modulate chromatin structure and gene expression, represent a class of anticancer agents that hold particular potential as radiation sensitizers. In this study, we examine the capacity of the HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) to modulate radiation response in human tumor cell lines and explore potential mechanisms underlying these interactions. Methods and materials: Cell proliferation: Exponentially growing tumor cells were incubated in medium containing 0-10 μM of SAHA for 72 h. Cells were fixed/stained with crystal violet to estimate cell viability. Apoptosis: Caspase activity was analyzed by fluorescence spectroscopy using a fluorescein labeled pan-caspase inhibitor. Cells were harvested after 48 h of exposure to SAHA (1.0 μM), radiation (6 Gy), or the combination. Whole cell lysates were evaluated for poly(ADP-ribose) polymerase (PARP) cleavage by western blot analysis. Radiation survival: Cells were exposed to varying doses of radiation ± 3 days pretreatment with SAHA (0.75-1.0 μM). After incubation intervals of 14-21 days, colonies were stained with crystal violet and manually counted. Immunocytochemistry: Cells were grown and treated in chamber slides. At specified times after treatment with SAHA, cells were fixed in paraformaldehyde, permeabilized in methanol, and probed with primary and secondary antibody solutions. Slides were analyzed using an epifluorescent microscope. Results: SAHA induced a dose-dependent inhibition of proliferation in human prostate (DU145) and glioma (U373vIII) cancer cell lines. Exposure to SAHA enhanced radiation-induced apoptosis as measured by caspase activity (p < 0.05) and PARP cleavage. The impact of SAHA on radiation response was further characterized using clonogenic survival analysis, which demonstrated that treatment with SAHA reduced tumor survival after radiation exposure. We identified several oncoproteins and DNA damage repair proteins

  3. Haloperidol counteracts the ketamine-induced disruption of processing negativity, but not that of the P300 amplitude

    DEFF Research Database (Denmark)

    Oranje, Bob; Gispen-de Wied, Christine C; Westenberg, Herman G M

    2009-01-01

    . Besides exerting an antagonistic effect on NMDA receptors, they have agonistic effects on dopamine D2 receptors. Can haloperidol (D2 antagonist) counteract the disruptive effects of ketamine on psychophysiological parameters of human attention? In a randomized, double-blind, placebo-controlled experiment...... 18 healthy male volunteers received placebo/placebo, placebo/ketamine (0.3 mg/kg i.v.) and haloperidol (2 mg)/ketamine (0.3 mg/kg i.v.) on three separate test days, after which they were tested in an auditory selective-attention paradigm. Haloperidol/ketamine reduced task performance compared...... to placebo/placebo, while the task performance in these two treatments did not differ from placebo/ketamine. Furthermore, placebo/ketamine reduced processing negativity compared to both placebo/placebo and haloperidol/ketamine, while processing negativity did not differ between placebo...

  4. Grazing management can counteract the impacts of climate change-induced sea level rise on salt marsh-dependent waterbirds

    DEFF Research Database (Denmark)

    Clausen, Kevin Kuhlmann; Stjernholm, Michael; Clausen, Preben

    2013-01-01

    with these changes. In addition, we quantify the areal extent of inadequate salt marsh management in four EU Special Protection Areas for Birds, and demonstrate concurrent population dynamics in four species relying on managed habitats. We conclude by investigating potential compensation for climate change......1) Climate change–induced rises in sea level threaten to drastically reduce the areal extent of important salt marsh habitats for large numbers of waterfowl and waders. Furthermore, recent changes in management practice have rendered existent salt marshes unfavourable to many birds, as lack...... (around 1 cow per hectare) is an important initiative to counteract the accelerating climate change–induced habitat loss in near-coastal areas across the globe, and to secure priority salt marsh habitats that support internationally important populations of breeding, wintering and staging waterfowl...

  5. Mycobacterium tuberculosis has diminished capacity to counteract redox stress induced by elevated levels of endogenous superoxide.

    Science.gov (United States)

    Tyagi, Priyanka; Dharmaraja, Allimuthu T; Bhaskar, Ashima; Chakrapani, Harinath; Singh, Amit

    2015-07-01

    Mycobacterium tuberculosis (Mtb) has evolved protective and detoxification mechanisms to maintain cytoplasmic redox balance in response to exogenous oxidative stress encountered inside host phagocytes. In contrast, little is known about the dynamic response of this pathogen to endogenous oxidative stress generated within Mtb. Using a noninvasive and specific biosensor of cytoplasmic redox state of Mtb, we for first time discovered a surprisingly high sensitivity of this pathogen to perturbation in redox homeostasis induced by elevated endogenous reactive oxygen species (ROS). We synthesized a series of hydroquinone-based small molecule ROS generators and found that ATD-3169 permeated mycobacteria to reliably enhance endogenous ROS including superoxide radicals. When Mtb strains including multidrug-resistant (MDR) and extensively drug-resistant (XDR) patient isolates were exposed to this compound, a dose-dependent, long-lasting, and irreversible oxidative shift in intramycobacterial redox potential was detected. Dynamic redox potential measurements revealed that Mtb had diminished capacity to restore cytoplasmic redox balance in comparison with Mycobacterium smegmatis (Msm), a fast growing nonpathogenic mycobacterial species. Accordingly, Mtb strains were extremely susceptible to inhibition by ATD-3169 but not Msm, suggesting a functional linkage between dynamic redox changes and survival. Microarray analysis showed major realignment of pathways involved in redox homeostasis, central metabolism, DNA repair, and cell wall lipid biosynthesis in response to ATD-3169, all consistent with enhanced endogenous ROS contributing to lethality induced by this compound. This work provides empirical evidence that the cytoplasmic redox poise of Mtb is uniquely sensitive to manipulation in steady-state endogenous ROS levels, thus revealing the importance of targeting intramycobacterial redox metabolism for controlling TB infection. Copyright © 2015 The Authors. Published by

  6. Bovine lactoferrin counteracts Toll-like receptor mediated activation signals in antigen presenting cells.

    Directory of Open Access Journals (Sweden)

    Patrizia Puddu

    Full Text Available Lactoferrin (LF, a key element in mammalian immune system, plays pivotal roles in host defence against infection and excessive inflammation. Its protective effects range from direct antimicrobial activities against a large panel of microbes, including bacteria, viruses, fungi and parasites, to antinflammatory and anticancer activities. In this study, we show that monocyte-derived dendritic cells (MD-DCs generated in the presence of bovine LF (bLF fail to undergo activation by up-modulating CD83, co-stimulatory and major histocompatibility complex molecules, and cytokine/chemokine secretion. Moreover, these cells are weak activators of T cell proliferation and retain antigen uptake activity. Consistent with an impaired maturation, bLF-MD-DC primed T lymphocytes exhibit a functional unresponsiveness characterized by reduced expression of CD154 and impaired expression of IFN-γ and IL-2. The observed imunosuppressive effects correlate with an increased expression of molecules with negative regulatory functions (i.e. immunoglobulin-like transcript 3 and programmed death ligand 1, indoleamine 2,3-dioxygenase, and suppressor of cytokine signaling-3. Interestingly, bLF-MD-DCs produce IL-6 and exhibit constitutive signal transducer and activator of transcription 3 activation. Conversely, bLF exposure of already differentiated MD-DCs completely fails to induce IL-6, and partially inhibits Toll-like receptor (TLR agonist-induced activation. Cell-specific differences in bLF internalization likely account for the distinct response elicited by bLF in monocytes versus immature DCs, providing a mechanistic base for its multiple effects. These results indicate that bLF exerts a potent anti-inflammatory activity by skewing monocyte differentiation into DCs with impaired capacity to undergo activation and to promote Th1 responses. Overall, these bLF-mediated effects may represent a strategy to block excessive DC activation upon TLR-induced inflammation, adding

  7. Sexual stigma and symbolic violence experienced, enacted, and counteracted in young Africans' writing about same-sex attraction.

    Science.gov (United States)

    Winskell, Kate; Sabben, Gaëlle

    2016-07-01

    There is growing recognition of the health disparities faced by sexual minority populations and the critical role played by sexual stigma in increasing their vulnerability. Experienced, anticipated, and internalized, stigma based on sexual orientation reduces access to HIV/STI prevention and treatment services among African men who have sex with men and has been linked to compromised mental health, risk-taking, and HIV status. It is likely that similar processes undermine the health of sexual minority African women and transgender and non-binary people. There is a need for increased understanding of both the contextual factors and the cultural meanings, or symbolic violence, that inform sexual stigma and harmful stigma management strategies in contexts that are culturally and socio-politically oppressive for sexual and gender minorities. Using thematic data analysis and narrative-based methodologies, we analyzed narratives and essays on same-sex attraction contributed by young people aged 13-24 from ten African countries to a Spring 2013 scriptwriting competition on HIV, sexuality, and related themes. Submitted by 27 male and 29 female authors, the texts were written in response to a prompt inviting participants to "Tell a story about someone who is attracted to people of the same sex". We analyzed the ways in which sexual stigma and its effects are described, enacted, and counteracted in the texts. The data provide insights into the social and symbolic processes that create and sustain sexual stigma in the context of broader transnational discourses. The data shed light on psychosocial challenges faced by sexual minority youth and identify both rhetoric, stereotypes, and discourse that devalue them and representations that counteract this symbolic violence. We share our findings in the hope they may inform education and communication programming as part of multi-level efforts to improve the health and human rights of sexual minority populations in sub

  8. Phenylbutyrate counteracts Shigella mediated downregulation of cathelicidin in rabbit lung and intestinal epithelia: a potential therapeutic strategy.

    Directory of Open Access Journals (Sweden)

    Protim Sarker

    Full Text Available BACKGROUND: Cathelicidins and defensins are endogenous antimicrobial peptides (AMPs that are downregulated in the mucosal epithelia of the large intestine in shigellosis. Oral treatment of Shigella infected rabbits with sodium butyrate (NaB reduces clinical severity and counteracts the downregulation of cathelicidin (CAP-18 in the large intestinal epithelia. AIMS: To develop novel regimen for treating infectious diseases by inducing innate immunity, we selected sodium 4-phenylbutyrate (PB, a registered drug for a metabolic disorder as a potential therapeutic candidate in a rabbit model of shigellosis. Since acute respiratory infections often cause secondary complications during shigellosis, the systemic effect of PB and NaB on CAP-18 expression in respiratory epithelia was also evaluated. METHODS: The readouts were clinical outcomes, CAP-18 expression in mucosa of colon, rectum, lung and trachea (immunohistochemistry and real-time PCR and release of the CAP-18 peptide/protein in stool (Western blot. PRINCIPAL FINDINGS: Significant downregulation of CAP-18 expression in the epithelia of rectum and colon, the site of Shigella infection was confirmed. Interestingly, reduced expression of CAP-18 was also noticed in the epithelia of lung and trachea, indicating a systemic effect of the infection. This suggests a causative link to acute respiratory infections during shigellosis. Oral treatment with PB resulted in reduced clinical illness and upregulation of CAP-18 in the epithelium of rectum. Both PB and NaB counteracted the downregulation of CAP-18 in lung epithelium. The drug effect is suggested to be systemic as intravenous administration of NaB could also upregulate CAP-18 in the epithelia of lung, rectum and colon. CONCLUSION: Our results suggest that PB has treatment potential in human shigellosis. Enhancement of CAP-18 in the mucosal epithelia of the respiratory tract by PB or NaB is a novel discovery. This could mediate protection from

  9. Phenylbutyrate counteracts Shigella mediated downregulation of cathelicidin in rabbit lung and intestinal epithelia: a potential therapeutic strategy.

    Science.gov (United States)

    Sarker, Protim; Ahmed, Sultan; Tiash, Snigdha; Rekha, Rokeya Sultana; Stromberg, Roger; Andersson, Jan; Bergman, Peter; Gudmundsson, Gudmundur H; Agerberth, Birgitta; Raqib, Rubhana

    2011-01-01

    Cathelicidins and defensins are endogenous antimicrobial peptides (AMPs) that are downregulated in the mucosal epithelia of the large intestine in shigellosis. Oral treatment of Shigella infected rabbits with sodium butyrate (NaB) reduces clinical severity and counteracts the downregulation of cathelicidin (CAP-18) in the large intestinal epithelia. To develop novel regimen for treating infectious diseases by inducing innate immunity, we selected sodium 4-phenylbutyrate (PB), a registered drug for a metabolic disorder as a potential therapeutic candidate in a rabbit model of shigellosis. Since acute respiratory infections often cause secondary complications during shigellosis, the systemic effect of PB and NaB on CAP-18 expression in respiratory epithelia was also evaluated. The readouts were clinical outcomes, CAP-18 expression in mucosa of colon, rectum, lung and trachea (immunohistochemistry and real-time PCR) and release of the CAP-18 peptide/protein in stool (Western blot). Significant downregulation of CAP-18 expression in the epithelia of rectum and colon, the site of Shigella infection was confirmed. Interestingly, reduced expression of CAP-18 was also noticed in the epithelia of lung and trachea, indicating a systemic effect of the infection. This suggests a causative link to acute respiratory infections during shigellosis. Oral treatment with PB resulted in reduced clinical illness and upregulation of CAP-18 in the epithelium of rectum. Both PB and NaB counteracted the downregulation of CAP-18 in lung epithelium. The drug effect is suggested to be systemic as intravenous administration of NaB could also upregulate CAP-18 in the epithelia of lung, rectum and colon. Our results suggest that PB has treatment potential in human shigellosis. Enhancement of CAP-18 in the mucosal epithelia of the respiratory tract by PB or NaB is a novel discovery. This could mediate protection from secondary respiratory infections that frequently are the lethal causes in

  10. Melatonin counteracts changes in hypothalamic gene expression of signals regulating feeding behavior in high-fat fed rats.

    Science.gov (United States)

    Ríos-Lugo, María J; Jiménez-Ortega, Vanesa; Cano-Barquilla, Pilar; Mateos, Pilar Fernández; Spinedi, Eduardo J; Cardinali, Daniel P; Esquifino, Ana I

    2015-03-01

    Previous studies indicate that the administration of melatonin caused body weight and abdominal visceral fat reductions in rodent models of hyperadiposity. The objective of the present study performed in high-fat fed rats was to evaluate the activity of melatonin on gene expression of some medial basal hypothalamus (MBH) signals involved in feeding behavior regulation, including neuropeptide Y (NPY), proopiomelanocortin (POMC), prolactin-releasing peptide (PrRP), leptin- and insulin-receptors (R) and insulin-R substrate (IRS)-1 and -2. Blood levels of leptin and adiponectin were also measured. Adult Wistar male rats were divided into four groups (n=16 per group): (i) control diet (3% fat); (ii) high-fat (35%) diet; (iii) high-fat diet+melatonin; (iv) control diet+melatonin. Rats had free access to high-fat or control chow and one of the following drinking solutions: (a) tap water; (b) 25 μg/mL of melatonin. After 10 weeks, the high-fat fed rats showed augmented MBH mRNA levels of NPY, leptin-R, PrRP, insulin-R, IRS-1 and IRS-2. The concomitant administration of melatonin counteracted this increase. Feeding of rats with a high-fat diet augmented expression of the MBH POMC gene through an effect insensitive to melatonin treatment. The augmented levels of circulating leptin and adiponectin seen in high-fat fed rats were counteracted by melatonin as was the augmented body weight: melatonin significantly attenuated a body weight increase in high-fat fed rats without affecting chow or water consumption. Melatonin augmented plasma leptin and adiponectin in control rats. The results indicate that an effect on gene expression of feeding behavior signals at the central nervous system (CNS) may complement a peripheral rise of the energy expenditure produced by melatonin to decrease body weight in high-fat fed rats.

  11. Interspecific competition counteracts negative effects of dispersal on adaptation of an arthropod herbivore to a new host.

    Science.gov (United States)

    Alzate, A; Bisschop, K; Etienne, R S; Bonte, D

    2017-11-01

    Dispersal and competition have both been suggested to drive variation in adaptability to a new environment, either positively or negatively. A simultaneous experimental test of both mechanisms is however lacking. Here, we experimentally investigate how population dynamics and local adaptation to a new host plant in a model species, the two-spotted spider mite (Tetranychus urticae), are affected by dispersal from a stock population (no-adapted) and competition with an already adapted spider mite species (Tetranychus evansi). For the population dynamics, we find that competition generally reduces population size and increases the risk of population extinction. However, these negative effects are counteracted by dispersal. For local adaptation, the roles of competition and dispersal are reversed. Without competition, dispersal exerts a negative effect on adaptation (measured as fecundity) to a novel host and females receiving the highest number of immigrants performed similarly to the stock population females. By contrast, with competition, adding more immigrants did not result in a lower fecundity. Females from populations with competition receiving the highest number of immigrants had a significantly higher fecundity than females from populations without competition (same dispersal treatment) and than the stock population females. We suggest that by exerting a stronger selection on the adapting populations, competition can counteract the migration load effect of dispersal. Interestingly, adaptation to the new host does not significantly reduce performance on the ancestral host, regardless of dispersal rate or competition. Our results highlight that assessments of how species can adapt to changing conditions need to jointly consider connectivity and the community context. © 2017 The Authors. Journal of Evolutionary Biology Published by John Wiley & Sons ltd on Behalf of European Society for Evolutionary Biology.

  12. The analgesic agent tapentadol inhibits calcitonin gene-related peptide release from isolated rat brainstem via a serotonergic mechanism.

    Science.gov (United States)

    Greco, Maria Cristina; Navarra, Pierluigi; Tringali, Giuseppe

    2016-01-15

    In this study we tested the hypothesis that tapentadol inhibits GGRP release from the rat brainstem through a mechanism mediated by the inhibition of NA reuptake; as a second alternative hypothesis, we investigated whether tapentadol inhibits GGRP release via the inhibition of 5-HT reuptake. Rat brainstems were explanted and incubated in short-term experiments. CGRP released in the incubation medium was taken as a marker of CGRP release from the central terminals of trigeminal neurons within the brainstem. CGRP levels were measured by radioimmunoassay under basal conditions or in the presence of tapentadol; NA, 5-HT, clonidine, yohimbine and ondansetron were used as pharmacological tools to investigate the action mechanism of tapentadol. The α2-antagonist yohimbine failed to counteract the effects of tapentadol. Moreover, neither NA nor the α2-agonist clonidine per se inhibited K(+)-stimulated CGRP release, thereby indicating that the effects of tapentadol are nor mediated through the block of NA reuptake. Further experiments showed that 5-HT and tramadol, which inhibits both NA and 5-HT reuptake, significantly reduced K(+)-stimulated CGRP release. Moreover, the 5-HT3 antagonist ondansetron was able to counteract the effects of tapentadol in this system. This study provided pharmacological evidence that tapentadol inhibits stimulated CGRP release from the rat brainstem in vitro through a mechanism involving an increase in 5-HT levels in the system and the subsequent activation of 5-HT3 receptors. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. PARP16/ARTD15 is a novel endoplasmic-reticulum-associated mono-ADP-ribosyltransferase that interacts with, and modifies karyopherin-ß1.

    Directory of Open Access Journals (Sweden)

    Simone Di Paola

    Full Text Available BACKGROUND: Protein mono-ADP-ribosylation is a reversible post-translational modification that modulates the function of target proteins. The enzymes that catalyze this reaction in mammalian cells are either bacterial pathogenic toxins or endogenous cellular ADP-ribosyltransferases. The latter include members of three different families of proteins: the well characterized arginine-specific ecto-enzymes ARTCs, two sirtuins and, more recently, novel members of the poly(ADP-ribose polymerase (PARP/ARTD family that have been suggested to act as cellular mono-ADP-ribosyltransferases. Here, we report on the characterisation of human ARTD15, the only known ARTD family member with a putative C-terminal transmembrane domain. METHODOLOGY/PRINCIPAL FINDINGS: Immunofluorescence and electron microscopy were performed to characterise the sub-cellular localisation of ARTD15, which was found to be associated with membranes of the nuclear envelope and endoplasmic reticulum. The orientation of ARTD15 was determined using protease protection assay, and is shown to be a tail-anchored protein with a cytosolic catalytic domain. Importantly, by combining immunoprecipitation with mass spectrometry and using cell lysates from cells over-expressing FLAG-ARTD15, we have identified karyopherin-ß1, a component of the nuclear trafficking machinery, as a molecular partner of ARTD15. Finally, we demonstrate that ARTD15 is a mono-ADP-ribosyltransferase able to induce the ADP-ribosylation of karyopherin-ß1, thus defining the first substrate for this enzyme. CONCLUSIONS/SIGNIFICANCE: Our data reveal that ARTD15 is a novel ADP-ribosyltransferase enzyme with a new intracellular location. Finally, the identification of karyopherin-ß1 as a target of ARTD15-mediated ADP-ribosylation, hints at a novel regulatory mechanism of karyopherin-ß1 functions.

  14. The irreversible ERBB1/2/4 inhibitor neratinib interacts with the PARP1 inhibitor niraparib to kill ovarian cancer cells.

    Science.gov (United States)

    Booth, Laurence; Roberts, Jane L; Samuel, Peter; Avogadri-Connors, Francesca; Cutler, Richard E; Lalani, Alshad S; Poklepovic, Andrew; Dent, Paul

    2018-06-03

    The irreversible ERBB1/2/4 inhibitor neratinib has been shown to rapidly down-regulate the expression of ERBB1/2/4 as well as the levels of c-MET, PDGFRα and mutant RAS proteins via autophagic degradation. Neratinib interacted in an additive to synergistic fashion with the approved PARP1 inhibitor niraparib to kill ovarian cancer cells. Neratinib and niraparib caused the ATM-dependent activation of AMPK which in turn was required to cause mTOR inactivation, ULK-1 activation and ATG13 phosphorylation. The drug combination initially increased autophagosome levels followed later by autolysosome levels. Preventing autophagosome formation by expressing activated mTOR or knocking down of Beclin1, or knock down of the autolysosome protein cathepsin B, reduced drug combination lethality. The drug combination caused an endoplasmic reticulum stress response as judged by enhanced eIF2α phosphorylation that was responsible for reducing MCL-1 and BCL-XL levels and increasing ATG5 and Beclin1 expression. Knock down of BIM, but not of BAX or BAK, reduced cell killing. Expression of activated MEK1 prevented the drug combination increasing BIM expression and reduced cell killing. Downstream of the mitochondrion, drug lethality was partially reduced by knock down of AIF, but expression of dominant negative caspase 9 was not protective. Our data demonstrate that neratinib and niraparib interact to kill ovarian cancer cells through convergent DNA damage and endoplasmic reticulum stress signaling. Cell killing required the induction of autophagy and was cathepsin B and AIF -dependent, and effector caspase independent.

  15. A Sensitive and Robust Ultra HPLC Assay with Tandem Mass Spectrometric Detection for the Quantitation of the PARP Inhibitor Olaparib (AZD2281 in Human Plasma for Pharmacokinetic Application

    Directory of Open Access Journals (Sweden)

    Jeffrey Roth

    2014-06-01

    Full Text Available Olaparib (AZD2281 is an orally active PARP-1 inhibitor, primarily effective against cancers with BRCA1/2 mutations. It is currently in Phase III development and has previously been investigated in numerous clinical trials, both as a single agent and in combination with chemotherapy. Despite this widespread testing, there is only one published method that provides assay details and stability studies for olaparib alone. A more sensitive uHPLC-MS/MS method for the quantification of olaparib in human plasma was developed, increasing the range of quantification at both ends (0.5–50,000 ng/mL compared to previously published methods (10–5,000 ng/mL. The wider range encompasses CMAX levels produced by typical olaparib doses and permits better pharmacokinetic modeling of olaparib elimination. This assay also utilizes a shorter analytical runtime, allowing for more rapid quantification and reduced use of reagents. A liquid-liquid extraction was followed by chromatographic separation on a Waters UPLC® BEH C18 column (2.1 × 50 mm, 1.7 µm and mass spectrometric detection. The mass transitions m/z 435.4→281.1 and m/z 443.2→281.1 were used for olaparib and the internal standard [2H8]-olaparib, respectively. The assay proved to be accurate (<9% deviation and precise (CV < 11%. Stability studies showed that olaparib is stable at room temperature for 24 h. in whole blood, at 4 °C for 24 h post-extraction, at −80 °C in plasma for at least 19 months, and through three freeze-thaw cycles. This method proved to be robust for measuring olaparib levels in clinical samples from a Phase I trial.

  16. ATM inhibition induces synthetic lethality and enhances sensitivity of PTEN-deficient breast cancer cells to cisplatin.

    Science.gov (United States)

    Li, Ke; Yan, Huaying; Guo, Wenhao; Tang, Mei; Zhao, Xinyu; Tong, Aiping; Peng, Yong; Li, Qintong; Yuan, Zhu

    2018-05-01

    PTEN deficiency often causes defects in DNA damage repair. Currently, effective therapies for breast cancer are lacking. ATM is an attractive target for cancer treatment. Previous studies suggested a synthetic lethality between PTEN and PARP. However, the synthetically lethal interaction between PTEN and ATM in breast cancer has not been reported. Moreover, the mechanism remains elusive. Here, using KU-60019, an ATM kinase inhibitor, we investigated ATM inhibition as a synthetically lethal strategy to target breast cancer cells with PTEN defects. We found that KU-60019 preferentially sensitizes PTEN-deficient MDA-MB-468 breast cancer cells to cisplatin, though it also slightly enhances sensitivity of PTEN wild-type breast cancer cells. The increased cytotoxic sensitivity is associated with apoptosis, as evidenced by flow cytometry and PARP cleavage. Additionally, the increase of DNA damage accumulation due to the decreased capability of DNA repair, as indicated by γ-H2AX and Rad51 foci, also contributed to this selective cytotoxicity. Mechanistically, compared with PTEN wild-type MDA-MB-231 cells, PTEN-deficient MDA-MB-468 cells have lower level of Rad51, higher ATM kinase activity, and display the elevated level of DNA damage. Moreover, these differences could be further enlarged by cisplatin. Our findings suggest that ATM is a promising target for PTEN-defective breast cancer. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. Construction of Structure of Indicators of Efficiency of Counteraction to Threats of Information Safety in Interests of the Estimation of Security of Information Processes in Computer Systems

    Directory of Open Access Journals (Sweden)

    A. P. Kurilo

    2010-06-01

    Full Text Available The theorem of system of indicators for an estimation of the security of information processes in the computer systems is formulated and proved. A number of the signs is proved, allowing to consider set of the indicators of efficiency of counteraction to the threats of information safety of the computer systems as the system.

  18. Attacks on the Network Synchronization Systems Counteraction Method Implemented in the Software and Hardware Device «MARSH! 3.0»

    Directory of Open Access Journals (Sweden)

    Dmitry Anatolevich Melnikov

    2013-12-01

    Full Text Available This paper proposes attacks on the network synchronization systems counteraction technique, method, algorithm and realizable aspects. The network synchronization systems are included in information technology systems or networks. This method is implemented in software and hardware device (means «MARSH! 3.0» providing trusted session.

  19. Testing the ability of non-methylamine osmolytes present in kidney cells to counteract the deleterious effects of urea on structure, stability and function of proteins.

    Directory of Open Access Journals (Sweden)

    Sheeza Khan

    Full Text Available Human kidney cells are under constant urea stress due to its urine concentrating mechanism. It is believed that the deleterious effect of urea is counteracted by methylamine osmolytes (glycine betaine and glycerophosphocholine present in kidney cells. A question arises: Do the stabilizing osmolytes, non-methylamines (myo-inositol, sorbitol and taurine present in the kidney cells also counteract the deleterious effects of urea? To answer this question, we have measured structure, thermodynamic stability (ΔG D (o and functional activity parameters (K m and k cat of different model proteins in the presence of various concentrations of urea and each non-methylamine osmolyte alone and in combination. We observed that (i for each protein myo-inositol provides perfect counteraction at 1∶2 ([myo-inositol]:[urea] ratio, (ii any concentration of sorbitol fails to refold urea denatured proteins if it is six times less than that of urea, and (iii taurine regulates perfect counteraction in a protein specific manner; 1.5∶2.0, 1.2∶2.0 and 1.0∶2.0 ([taurine]:[urea] ratios for RNase-A, lysozyme and α-lactalbumin, respectively.

  20. FoxP3 inhibits proliferation and induces apoptosis of gastric cancer cells by activating the apoptotic signaling pathway

    International Nuclear Information System (INIS)

    Ma, Gui-Fen; Chen, Shi-Yao; Sun, Zhi-Rong; Miao, Qing; Liu, Yi-Mei; Zeng, Xiao-Qing; Luo, Tian-Cheng; Ma, Li-Li; Lian, Jing-Jing; Song, Dong-Li

    2013-01-01

    Highlights: ► The article revealed FoxP3 gene function in gastric cancer firstly. ► Present the novel roles of FoxP3 in inhibiting proliferation and promoting apoptosis in gastric cancer cells. ► Overexpression of FoxP3 increased proapoptotic molecules and repressed antiapoptotic molecules. ► Silencing of FoxP3 reduced the expression of proapoptotic genes, such as PARP, caspase-3 and caspase-9. ► FoxP3 is sufficient for activating the apoptotic signaling pathway. -- Abstract: Forkhead Box Protein 3 (FoxP3) was identified as a key transcription factor to the occurring and function of the regulatory T cells (Tregs). However, limited evidence indicated its function in tumor cells. To elucidate the precise roles and underlying molecular mechanism of FoxP3 in gastric cancer (GC), we examined the expression of FoxP3 and the consequences of interfering with FoxP3 gene in human GC cell lines, AGS and MKN45, by multiple cellular and molecular approaches, such as immunofluorescence, gene transfection, CCK-8 assay, clone formation assay, TUNEL assay, Flow cytometry, immunoassay and quantities polymerase chain reaction (PCR). As a result, FoxP3 was expressed both in nucleus and cytoplasm of GC cells. Up-regulation of FoxP3 inhibited cell proliferation and promoted cell apoptosis. Overexpression of FoxP3 increased the protein and mRNA levels of proapoptotic molecules, such as poly ADP-ribose polymerase1 (PARP), caspase-3 and caspase-9, and repressed the expression of antiapoptotic molecules, such as cellular inhibitor of apoptosis-1 (c-IAP1) and the long isoform of B cell leukemia/lymphoma-2 (Bcl-2). Furthermore, silencing of FoxP3 by siRNA in GC cells reduced the expression of proapoptotic genes, such as PARP, caspase-3 and caspase-9. Collectively, our findings identify the novel roles of FoxP3 in inhibiting proliferation and inducing apoptosis in GC cells by regulating apoptotic signaling, which could be a promising therapeutic approach for gastric cancer.

  1. FoxP3 inhibits proliferation and induces apoptosis of gastric cancer cells by activating the apoptotic signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Gui-Fen [Department of Gastroenterology, Zhongshan Hospital, Fudan University, Shanghai (China); Chen, Shi-Yao, E-mail: shiyao_chen@163.com [Department of Gastroenterology, Zhongshan Hospital, Fudan University, Shanghai (China); Endoscopy Center, Zhongshan Hospital, Fudan University, Shanghai (China); Sun, Zhi-Rong [Department of Anesthesiology, Cancer Center, Fudan University, Shanghai (China); Miao, Qing; Liu, Yi-Mei; Zeng, Xiao-Qing; Luo, Tian-Cheng [Department of Gastroenterology, Zhongshan Hospital, Fudan University, Shanghai (China); Ma, Li-Li; Lian, Jing-Jing [Endoscopy Center, Zhongshan Hospital, Fudan University, Shanghai (China); Song, Dong-Li [Biomedical Research Center, Zhongshan Hospital, Fudan University, Shanghai (China)

    2013-01-11

    Highlights: Black-Right-Pointing-Pointer The article revealed FoxP3 gene function in gastric cancer firstly. Black-Right-Pointing-Pointer Present the novel roles of FoxP3 in inhibiting proliferation and promoting apoptosis in gastric cancer cells. Black-Right-Pointing-Pointer Overexpression of FoxP3 increased proapoptotic molecules and repressed antiapoptotic molecules. Black-Right-Pointing-Pointer Silencing of FoxP3 reduced the expression of proapoptotic genes, such as PARP, caspase-3 and caspase-9. Black-Right-Pointing-Pointer FoxP3 is sufficient for activating the apoptotic signaling pathway. -- Abstract: Forkhead Box Protein 3 (FoxP3) was identified as a key transcription factor to the occurring and function of the regulatory T cells (Tregs). However, limited evidence indicated its function in tumor cells. To elucidate the precise roles and underlying molecular mechanism of FoxP3 in gastric cancer (GC), we examined the expression of FoxP3 and the consequences of interfering with FoxP3 gene in human GC cell lines, AGS and MKN45, by multiple cellular and molecular approaches, such as immunofluorescence, gene transfection, CCK-8 assay, clone formation assay, TUNEL assay, Flow cytometry, immunoassay and quantities polymerase chain reaction (PCR). As a result, FoxP3 was expressed both in nucleus and cytoplasm of GC cells. Up-regulation of FoxP3 inhibited cell proliferation and promoted cell apoptosis. Overexpression of FoxP3 increased the protein and mRNA levels of proapoptotic molecules, such as poly ADP-ribose polymerase1 (PARP), caspase-3 and caspase-9, and repressed the expression of antiapoptotic molecules, such as cellular inhibitor of apoptosis-1 (c-IAP1) and the long isoform of B cell leukemia/lymphoma-2 (Bcl-2). Furthermore, silencing of FoxP3 by siRNA in GC cells reduced the expression of proapoptotic genes, such as PARP, caspase-3 and caspase-9. Collectively, our findings identify the novel roles of FoxP3 in inhibiting proliferation and inducing apoptosis

  2. INHIBITION IN SPEAKING PERFORMANCE

    OpenAIRE

    Humaera, Isna

    2015-01-01

    The most common problem encountered by the learner in the languageacquisition process is learner inhibition. Inhibition refers to a temperamentaltendency to display wariness, fearfulness, or restrain in response tounfamiliar people, objects, and situations. There are some factors that causeinhibition, such as lack of motivation, shyness, self-confidence, self-esteem,and language ego. There are also levels of inhibition, it refers to kinds ofinhibition and caused of inhibition itself. Teacher ...

  3. Lactobacillus salivarius REN counteracted unfavorable 4-nitroquinoline-1-oxide-induced changes in colonic microflora of rats.

    Science.gov (United States)

    Zhang, Ming; Qiao, Xuewei; Zhao, Liang; Jiang, Lu; Ren, Fazheng

    2011-12-01

    Probiotics and carcinogens both have a significant effect on the microfloral composition of the human intestine. The objective of this study was to investigate the impact of an important carcinogen, 4-Nitroquinoline-1-Oxide on colonic microflora and the efficacy of the probiotic Lactobacillus salivarius REN as an agent of counteracting these effects. Using denaturing gradient gel electrophoresis (DGGE) combined with redundancy analysis, we demonstrated that both 4-Nitroquinoline-1-Oxide and L. salivarius REN significantly altered the bacterial communities of rat colons. A total of 27 bacterial strains were identified as being affected by treatment with 4-Nitroquinoline-1-Oxide or L. salivarius REN using a t-value biplot combined with band sequencing. 4-Nitroquinoline-1-Oxide treatment increased the abundance of two potential pathogens (one Helicobacter strain and one Desulfovibrio strain), as well as reducing the abundance of two potentially beneficial strains (one Ruminococcaceae strain and one Rumen bacteria). The Helicobacter strain was initally detected in carcinogen-treated rat intestinal microflora, but L. salivarius REN treatment effectively suppressed the growth of the Helicobacter strain. These results suggested that L. salivarius REN may be a potential probiotic, efficiently acting against the initial infection with, and the growth of pathogenic bacteria.

  4. CNF1 Enhances Brain Energy Content and Counteracts Spontaneous Epileptiform Phenomena in Aged DBA/2J Mice.

    Directory of Open Access Journals (Sweden)

    Sara Travaglione

    Full Text Available Epilepsy, one of the most common conditions affecting the brain, is characterized by neuroplasticity and brain cell energy defects. In this work, we demonstrate the ability of the Escherichia coli protein toxin cytotoxic necrotizing factor 1 (CNF1 to counteract epileptiform phenomena in inbred DBA/2J mice, an animal model displaying genetic background with an high susceptibility to induced- and spontaneous seizures. Via modulation of the Rho GTPases, CNF1 regulates actin dynamics with a consequent increase in spine density and length in pyramidal neurons of rat visual cortex, and influences the mitochondrial homeostasis with remarkable changes in the mitochondrial network architecture. In addition, CNF1 improves cognitive performances and increases ATP brain content in mouse models of Rett syndrome and Alzheimer's disease. The results herein reported show that a single dose of CNF1 induces a remarkable amelioration of the seizure phenotype, with a significant augmentation in neuroplasticity markers and in cortex mitochondrial ATP content. This latter effect is accompanied by a decrease in the expression of mitochondrial fission proteins, suggesting a role of mitochondrial dynamics in the CNF1-induced beneficial effects on this epileptiform phenotype. Our results strongly support the crucial role of brain energy homeostasis in the pathogenesis of certain neurological diseases, and suggest that CNF1 could represent a putative new therapeutic tool for epilepsy.

  5. Counteracting foaming caused by lipids or proteins in biogas reactors using rapeseed oil or oleic acid as antifoaming agents.

    Science.gov (United States)

    Kougias, P G; Boe, K; Einarsdottir, E S; Angelidaki, I

    2015-08-01

    Foaming is one of the major operational problems in biogas plants, and dealing with foaming incidents is still based on empirical practices. Various types of antifoams are used arbitrarily to combat foaming in biogas plants, but without any scientific support this action can lead to serious deterioration of the methanogenic process. Many commercial antifoams are derivatives of fatty acids or oils. However, it is well known that lipids can induce foaming in manure based biogas plants. This study aimed to elucidate the effect of rapeseed oil and oleic acid on foam reduction and process performance in biogas reactors fed with protein or lipid rich substrates. The results showed that both antifoams efficiently suppressed foaming. Moreover rapeseed oil resulted in stimulation of the biogas production. Finally, it was reckoned that the chemical structure of lipids, and more specifically their carboxylic ends, is responsible for their foam promoting or foam counteracting behaviour. Thus, it was concluded that the fatty acids and oils could suppress foaming, while salt of fatty acids could generate foam. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. The Use of gamma-Irradiation in Counteracting the Effect of Salinity for Cultivation of Barley and Pea Plants

    International Nuclear Information System (INIS)

    Aly, M.A.S.; Afifi, L.M.; Kamel, H.A.; Mostafa, I.Y.; Kord, M.A.

    2000-01-01

    The biochemical changes induced by salinity in two economic plants (Barley and Pea) and the probable counteraction of gamma irradiation for enhancement of growth were studied. The data obtained revealed that the reduction in pigments content due to salinity treatment was more pronounced in pea plants than barley. However, gamma irradiation caused a significant increase in pigment content of both plants. The interaction effect of salinity and radiation varied from an increase in case of barley to a reduction in peas. In both plants, soluble sugars content increased due to salinity and /or gamma-radiation. Moreover, total carbohydrates increased due to the combined treatment. A matched increase in free proline content was recorded with increase of salinity. While, gamma-irradiation showed a different trend. Protein and nucleic acids contents were proportionally decreased with increase of salinity levels, whereas gamma radiation induced an increase in both protein and nucleic acids content. A progressive reduction in the yield by increasing salinity was observed, while gamma-irradiation increased the yield of both plants. 14 CO 2 fixation was reduced by salinity treatment while gamma-radiation increased it. Contrary to 14 CO 2 fixation, salinity enhanced respiration, while radiation retarded it

  7. The Replisome-Coupled E3 Ubiquitin Ligase Rtt101Mms22 Counteracts Mrc1 Function to Tolerate Genotoxic Stress.

    Directory of Open Access Journals (Sweden)

    Raymond Buser

    2016-02-01

    Full Text Available Faithful DNA replication and repair requires the activity of cullin 4-based E3 ubiquitin ligases (CRL4, but the underlying mechanisms remain poorly understood. The budding yeast Cul4 homologue, Rtt101, in complex with the linker Mms1 and the putative substrate adaptor Mms22 promotes progression of replication forks through damaged DNA. Here we characterized the interactome of Mms22 and found that the Rtt101(Mms22 ligase associates with the replisome progression complex during S-phase via the amino-terminal WD40 domain of Ctf4. Moreover, genetic screening for suppressors of the genotoxic sensitivity of rtt101Δ cells identified a cluster of replication proteins, among them a component of the fork protection complex, Mrc1. In contrast to rtt101Δ and mms22Δ cells, mrc1Δ rtt101Δ and mrc1Δ mms22Δ double mutants complete DNA replication upon replication stress by facilitating the repair/restart of stalled replication forks using a Rad52-dependent mechanism. Our results suggest that the Rtt101(Mms22 E3 ligase does not induce Mrc1 degradation, but specifically counteracts Mrc1's replicative function, possibly by modulating its interaction with the CMG (Cdc45-MCM-GINS complex at stalled forks.

  8. The novel dehydroepiandrosterone (DHEA) derivative BNN27 counteracts delay-dependent and scopolamine-induced recognition memory deficits in rats.

    Science.gov (United States)

    Pitsikas, Nikolaos; Gravanis, Achille

    2017-04-01

    Experimental evidence indicates that the neurosteroids dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulphate (DHEAS) are involved in cognition. BNN27 is a novel 17C spiroepoxy-DHEA derivative, which devoid of steroidogenic activity. The neuroprotective effects of BNN27 have been recently reported. The present study was designed to investigate the effects of BNN27 on recognition memory in rats. For this purpose, the novel object task (NOT), a procedure assessing non-spatial recognition memory and the novel location task (NLT), a procedure evaluating spatial recognition memory were used. Intraperitoneal (i.p.) administration of BNN27 (3 and 10mg/kg) antagonized delay-dependent deficits in the NOT in the normal rat, suggesting that this DHEA derivative affected acquisition, storage and retrieval of information. In addition, BNN27 (3 and 10mg/kg, i.p.) counteracted the scopolamine [0.2mg/kg, subcutaneously (s.c.)]-induced non-spatial and spatial recognition memory deficits. These findings suggest that BNN27 may modulate different aspects of recognition memory, potentially interacting with the cholinergic system, relevant to cognition. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Model Dependency of TMAO's Counteracting Effect Against Action of Urea: Kast Model versus Osmotic Model of TMAO.

    Science.gov (United States)

    Borgohain, Gargi; Paul, Sandip

    2016-03-10

    Classical molecular dynamics simulation of GB1 peptide (a 16-residue β-hairpin) in different osmotic environments is studied. Urea is used for denaturation of the peptide, and trimethylamine-N-oxide (TMAO) is used to offset the effect of urea. Protein-urea electrostatic interactions are found to play a major role in protein-denaturation. To emphasize on protein protecting action of TMAO against urea, two different models of TMAO are used, viz., the Kast model and the Osmotic model. We observe that the Osmotic model of TMAO gives the best protection to counteract urea's action when used in ratio 1:2 of urea:TMAO (i.e., reverse ratio). This is because the presence of TMAO makes urea-protein electrostatic interactions more unfavorable. Preferential solvation of TMAO molecules by urea (and water) molecules is also observed, which causes depletion in the number of urea molecules in the vicinity of the protein. The calculations of intraprotein hydrogen bonds between different residues of protein further reveal the breaking of backbone hydrogen bonds of residues 2 and 15 in the presence of urea, and the same is preserved in the presence of TMAO. Free energy landscapes show that the narrowest distribution is obtained for the osmotic TMAO model when used in reverse ratio.

  10. Putrescine biosynthesis in Lactococcus lactis is transcriptionally activated at acidic pH and counteracts acidification of the cytosol.

    Science.gov (United States)

    Del Rio, Beatriz; Linares, Daniel; Ladero, Victor; Redruello, Begoña; Fernandez, Maria; Martin, Maria Cruz; Alvarez, Miguel A

    2016-11-07

    Lactococcus lactis subsp. cremoris CECT 8666 is a lactic acid bacterium that synthesizes the biogenic amine putrescine from agmatine via the agmatine deiminase (AGDI) pathway. The AGDI genes cluster includes aguR. This encodes a transmembrane protein that functions as a one-component signal transduction system, the job of which is to sense the agmatine concentration of the medium and accordingly regulate the transcription of the catabolic operon aguBDAC. The latter encodes the proteins necessary for agmatine uptake and its conversion into putrescine. This work reports the effect of extracellular pH on putrescine biosynthesis and on the genetic regulation of the AGDI pathway. Increased putrescine biosynthesis was detected at acidic pH (pH5) compared to neutral pH. Acidic pH induced the transcription of the catabolic operon via the activation of the aguBDAC promoter PaguB. However, the external pH had no significant effect on the activity of the aguR promoter PaguR, or on the transcription of the aguR gene. The transcriptional activation of the AGDI pathway was also found to require a lower agmatine concentration at pH5 than at neutral pH. Finally, the following of the AGDI pathway counteracted the acidification of the cytoplasm under acidic external conditions, suggesting it to provide protection against acid stress. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Alpha-tocopheryl succinate inhibits autophagic survival of prostate cancer cells induced by vitamin K3 and ascorbate to trigger cell death.

    Science.gov (United States)

    Tomasetti, Marco; Nocchi, Linda; Neuzil, Jiri; Goodwin, Jacob; Nguyen, Maria; Dong, Lanfeng; Manzella, Nicola; Staffolani, Sara; Milanese, Claudio; Garrone, Beatrice; Alleva, Renata; Borghi, Battista; Santarelli, Lory; Guerrieri, Roberto

    2012-01-01

    The redox-silent vitamin E analog α-tocopheryl succinate (α-TOS) was found to synergistically cooperate with vitamin K3 (VK3) plus ascorbic acid (AA) in the induction of cancer cell-selective apoptosis via a caspase-independent pathway. Here we investigated the molecular mechanism(s) underlying cell death induced in prostate cancer cells by α-TOS, VK3 and AA, and the potential use of targeted drug combination in the treatment of prostate cancer. The generation of ROS, cellular response to oxidative stress, and autophagy were investigated in PC3 prostate cancer cells by using drugs at sub-toxic doses. We evaluated whether PARP1-mediated apoptosis-inducing factor (AIF) release plays a role in apoptosis induced by the combination of the agents. Next, the effect of the combination of α-TOS, VK3 and AA on tumor growth was examined in nude mice. VK3 plus AA induced early ROS formation associated with induction of autophagy in response to oxidative stress, which was reduced by α-TOS, preventing the formation of autophagosomes. α-TOS induced mitochondrial destabilization leading to the release of AIF. Translocation of AIF from mitochondria to the nucleus, a result of the combinatorial treatment, was mediated by PARP1 activation. The inhibition of AIF as well as of PARP1 efficiently attenuated apoptosis triggered by the drug combination. Using a mouse model of prostate cancer, the combination of α-TOS, VK3 and AA was more efficient in tumor suppression than when the drugs were given separately, without deleterious side effects. α-TOS, a mitochondria-targeting apoptotic agent, switches at sub-apoptotic doses from autophagy-dependent survival of cancer cells to their demise by promoting the induction of apoptosis. Given the grim prognosis for cancer patients, this finding is of potential clinical relevance.

  12. Alpha-tocopheryl succinate inhibits autophagic survival of prostate cancer cells induced by vitamin K3 and ascorbate to trigger cell death.

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    Marco Tomasetti

    Full Text Available BACKGROUND: The redox-silent vitamin E analog α-tocopheryl succinate (α-TOS was found to synergistically cooperate with vitamin K3 (VK3 plus ascorbic acid (AA in the induction of cancer cell-selective apoptosis via a caspase-independent pathway. Here we investigated the molecular mechanism(s underlying cell death induced in prostate cancer cells by α-TOS, VK3 and AA, and the potential use of targeted drug combination in the treatment of prostate cancer. METHODOLOGY/PRINCIPAL FINDINGS: The generation of ROS, cellular response to oxidative stress, and autophagy were investigated in PC3 prostate cancer cells by using drugs at sub-toxic doses. We evaluated whether PARP1-mediated apoptosis-inducing factor (AIF release plays a role in apoptosis induced by the combination of the agents. Next, the effect of the combination of α-TOS, VK3 and AA on tumor growth was examined in nude mice. VK3 plus AA induced early ROS formation associated with induction of autophagy in response to oxidative stress, which was reduced by α-TOS, preventing the formation of autophagosomes. α-TOS induced mitochondrial destabilization leading to the release of AIF. Translocation of AIF from mitochondria to the nucleus, a result of the combinatorial treatment, was mediated by PARP1 activation. The inhibition of AIF as well as of PARP1 efficiently attenuated apoptosis triggered by the drug combination. Using a mouse model of prostate cancer, the combination of α-TOS, VK3 and AA was more efficient in tumor suppression than when the drugs were given separately, without deleterious side effects. CONCLUSIONS/SIGNIFICANCE: α-TOS, a mitochondria-targeting apoptotic agent, switches at sub-apoptotic doses from autophagy-dependent survival of cancer cells to their demise by promoting the induction of apoptosis. Given the grim prognosis for cancer patients, this finding is of potential clinical relevance.

  13. Fluoroquinolone-mediated inhibition of cell growth, S-G2/M cell cycle arrest, and apoptosis in canine osteosarcoma cell lines.

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    Seo, Kyoung won; Holt, Roseline; Jung, Yong-Sam; Rodriguez, Carlos O; Chen, Xinbin; Rebhun, Robert B

    2012-01-01

    Despite significant advancements in osteosarcoma research, the overall survival of canine and human osteosarcoma patients has remained essentially static over the past 2 decades. Post-operative limb-spare infection has been associated with improved survival in both species, yet a mechanism for improved survival has not been clearly established. Given that the majority of canine osteosarcoma patients experiencing post-operative infections were treated with fluoroquinolone antibiotics, we hypothesized that fluoroquinolone antibiotics might directly inhibit the survival and proliferation of canine osteosarcoma cells. Ciprofloxacin or enrofloxacin were found to inhibit p21(WAF1) expression resulting in decreased proliferation and increased S-G(2)/M accumulation. Furthermore, fluoroquinolone exposure induced apoptosis of canine osteosarcoma cells as demonstrated by cleavage of caspase-3 and PARP, and activation of caspase-3/7. These results support further studies examining the potential impact of quinolones on survival and proliferation of osteosarcoma.

  14. Fluoroquinolone-mediated inhibition of cell growth, S-G2/M cell cycle arrest, and apoptosis in canine osteosarcoma cell lines.

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    Kyoung won Seo

    Full Text Available Despite significant advancements in osteosarcoma research, the overall survival of canine and human osteosarcoma patients has remained essentially static over the past 2 decades. Post-operative limb-spare infection has been associated with improved survival in both species, yet a mechanism for improved survival has not been clearly established. Given that the majority of canine osteosarcoma patients experiencing post-operative infections were treated with fluoroquinolone antibiotics, we hypothesized that fluoroquinolone antibiotics might directly inhibit the survival and proliferation of canine osteosarcoma cells. Ciprofloxacin or enrofloxacin were found to inhibit p21(WAF1 expression resulting in decreased proliferation and increased S-G(2/M accumulation. Furthermore, fluoroquinolone exposure induced apoptosis of canine osteosarcoma cells as demonstrated by cleavage of caspase-3 and PARP, and activation of caspase-3/7. These results support further studies examining the potential impact of quinolones on survival and proliferation of osteosarcoma.

  15. Tob1 induces apoptosis and inhibits proliferation, migration and invasion of gastric cancer cells by activating Smad4 and inhibiting β‑catenin signaling.

    Science.gov (United States)

    Kundu, Juthika; Wahab, S M Riajul; Kundu, Joydeb Kumar; Choi, Yoon-La; Erkin, Ozgur Cem; Lee, Hun Seok; Park, Sang Gyu; Shin, Young Kee

    2012-09-01

    Transducer of ErbB-2.1 (Tob1), a tumor suppressor protein, is inactivated in a variety of cancers including stomach cancer. However, the role of Tob1 in gastric carcinogenesis remains elusive. The present study aimed to investigate whether Tob1 could inhibit gastric cancer progression in vitro, and to elucidate its underlying molecular mechanisms. We found differential expression of Tob1 in human gastric cancer (MKN28, AGS and MKN1) cells. The overexpression of Tob1 induced apoptosis in MKN28 and AGS cells, which was associated with sub-G1 arrest, activation of caspase-3, induction of Bax, inhibition of Bcl-2 and cleavage of poly (ADP-ribose) polymerase (PARP). In addition, Tob1 inhibited proliferation, migration and invasion, which were reversed in MKN1 and AGS cells transfected with Tob1 siRNA. Overexpression of Tob1 in MKN28 and AGS cells induced the expression of Smad4, leading to the increased expression and the promoter activity of p15, which was diminished by silencing of Tob1 using specific siRNA. Tob1 decreased the phosphorylation of Akt and glycogen synthase kinase-3β (GSK3β) in MKN28 and AGS cells, resulting in the reduced protein expression and the transcriptional activity of β‑catenin, which in turn decreased the expression of cyclin D1, cyclin-dependent kinase-4 (CDK4), urokinase plasminogen activator receptor (uPAR) and peroxisome proliferator and activator receptor-δ (PPARδ). Conversely, silencing of Tob1 induced the phosphorylation of Akt and GSK-3β, and increased the expression of β‑catenin and its target genes. Collectively, our study demonstrates that the overexpression of Tob1 inhibits gastric cancer progression by activating Smad4- and inhibiting β‑catenin-mediated signaling pathways.

  16. Effect of dicycloplatin, a novel platinum chemotherapeutical drug, on inhibiting cell growth and inducing cell apoptosis.

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    Guang-quan Li

    Full Text Available Dicycloplatin, a new supramolecular platinum-based antitumor drug, has been approved by the State Food and Administration (SFDA of China. In this study, we investigated the anticancer activity of dicycloplatin in cancer cells and signaling pathways involved in dicycloplatin-induced apoptosis. Dicycloplatin inhibited the proliferation of cancer cells and increased the percentage of apoptosis in a concentration-dependent manner. Besides, some apoptosis related events were observed after treatment with dicycloplatin, including increase of reactive oxygen species (ROS, collapse of mitochondrial membrane potential (Δψm, release of cytochrome c from the mitochondria to the cytosol, upregulation of p53, which were accompanied by activation of caspase-9, caspase-3, caspase-8, and poly (ADP-ribose polymerase cleavage in a concentration-dependent manner. The role of apoptosis in dicycloplatin-mediated cell death was further confirmed by the concomitant treatment with caspase-8 or caspase-9 inhibitors, which inhibited apoptosis and PARP cleavage. Intracellular glutathione (GSH was also found to inhibit the cytotoxic effect of dicycloplatin. In conclusion, these findings suggest that dicycloplatin induces apoptosis through ROS stress-mediated death receptor pathway and mitochondrial pathway which is similar to carboplatin.

  17. Kaempferol inhibits gastric cancer tumor growth: An in vitro and in vivo study.

    Science.gov (United States)

    Song, Haibin; Bao, Junjie; Wei, Yuzhe; Chen, Yang; Mao, Xiaoguang; Li, Jianguo; Yang, Zhiwei; Xue, Yingwei

    2015-02-01

    Kaempferol, which is one of the general flavonoids, has recently been reported to suppress proliferation, induce cell cycle arrest and promote apoptosis in various human cancer cell lines. In the present study, the effect and mechanism of kaempferol on gastric cancer (GC) was examined. The results showed that kaempferol significantly inhibited the proliferation of MKN28 and SGC7901 cell lines. However, no significant inhibition in the GSE-1 normal gastric epithelial cell line in our experimental dose was detected. Additionally, significant apoptosis and G2/M phase cell cycle arrest were identified following the treatment of kaempferol. More importantly, we observed that kaempferol inhibited the growth of the tumor xenografts although no marked effects on liver, spleen or body weight were induced. The expression levels of G2/M cell cycle‑regulating factors, cyclin B1, Cdk1 and Cdc25C, were significantly reduced. In addition, kaempferol treatment markedly decreased the level of Bcl-2 concomitant with an increase in Bax expression, resulting in the upregulation of cleaved caspase-3 and -9, which promoted PARP cleavage. Kaempferol-treated cells also led to a decrease in p-Akt, p-ERK and COX-2 expression levels. The present study therefore provided evidence that kaempferol may be a therapeutic agent for GC.

  18. Zika virus infection dysregulates human neural stem cell growth and inhibits differentiation into neuroprogenitor cells.

    Science.gov (United States)

    Devhare, Pradip; Meyer, Keith; Steele, Robert; Ray, Ratna B; Ray, Ranjit

    2017-10-12

    The current outbreak of Zika virus-associated diseases in South America and its threat to spread to other parts of the world has emerged as a global health emergency. A strong link between Zika virus and microcephaly exists, and the potential mechanisms associated with microcephaly are under intense investigation. In this study, we evaluated the effect of Zika virus infection of Asian and African lineages (PRVABC59 and MR766) in human neural stem cells (hNSCs). These two Zika virus strains displayed distinct infection pattern and growth rates in hNSCs. Zika virus MR766 strain increased serine 139 phosphorylation of histone H2AX (γH2AX), a known early cellular response proteins to DNA damage. On the other hand, PRVABC59 strain upregulated serine 15 phosphorylation of p53, p21 and PUMA expression. MR766-infected cells displayed poly (ADP-ribose) polymerase (PARP) and caspase-3 cleavage. Interestingly, infection of hNSCs by both strains of Zika virus for 24 h, followed by incubation in astrocyte differentiation medium, induced rounding and cell death. However, astrocytes generated from hNSCs by incubation in differentiation medium when infected with Zika virus displayed minimal cytopathic effect at an early time point. Infected hNSCs incubated in astrocyte differentiating medium displayed PARP cleavage within 24-36 h. Together, these results showed that two distinct strains of Zika virus potentiate hNSC growth inhibition by different mechanisms, but both viruses strongly induce death in early differentiating neuroprogenitor cells even at a very low multiplicity of infection. Our observations demonstrate further mechanistic insights for impaired neuronal homeostasis during active Zika virus infection.

  19. Zika virus infection dysregulates human neural stem cell growth and inhibits differentiation into neuroprogenitor cells

    Science.gov (United States)

    Devhare, Pradip; Meyer, Keith; Steele, Robert; Ray, Ratna B; Ray, Ranjit

    2017-01-01

    The current outbreak of Zika virus-associated diseases in South America and its threat to spread to other parts of the world has emerged as a global health emergency. A strong link between Zika virus and microcephaly exists, and the potential mechanisms associated with microcephaly are under intense investigation. In this study, we evaluated the effect of Zika virus infection of Asian and African lineages (PRVABC59 and MR766) in human neural stem cells (hNSCs). These two Zika virus strains displayed distinct infection pattern and growth rates in hNSCs. Zika virus MR766 strain increased serine 139 phosphorylation of histone H2AX (γH2AX), a known early cellular response proteins to DNA damage. On the other hand, PRVABC59 strain upregulated serine 15 phosphorylation of p53, p21 and PUMA expression. MR766-infected cells displayed poly (ADP-ribose) polymerase (PARP) and caspase-3 cleavage. Interestingly, infection of hNSCs by both strains of Zika virus for 24 h, followed by incubation in astrocyte differentiation medium, induced rounding and cell death. However, astrocytes generated from hNSCs by incubation in differentiation medium when infected with Zika virus displayed minimal cytopathic effect at an early time point. Infected hNSCs incubated in astrocyte differentiating medium displayed PARP cleavage within 24–36 h. Together, these results showed that two distinct strains of Zika virus potentiate hNSC growth inhibition by different mechanisms, but both viruses strongly induce death in early differentiating neuroprogenitor cells even at a very low multiplicity of infection. Our observations demonstrate further mechanistic insights for impaired neuronal homeostasis during active Zika virus infection. PMID:29022904

  20. Inhibition of histone deacetylase for the treatment of biliary tract cancer: A new effective pharmacological approach

    Science.gov (United States)

    Bluethner, Thilo; Niederhagen, Manuel; Caca, Karel; Serr, Frederik; Witzigmann, Helmut; Moebius, Christian; Mossner, Joachim; Wiedmann, Marcus

    2007-01-01

    AIM: To investigate in vitro and in vivo therapeutic effects of histone deacetylase inhibitors NVP-LAQ824 and NVP-LBH589 on biliary tract cancer. METHODS: Cell growth inhibition by NVP-LAQ824 and NVP-LBH589 was studied in vitro in 7 human biliary tract cancer cell lines by MTT assay. In addition, the anti-tumoral effect of NVP-LBH589 was studied in a chimeric mouse model. Anti-tumoral drug mechanism was assessed by immunoblotting for acH4 and p21WAF-1/CIP-1, PARP assay, cell cycle analysis, TUNEL assay, and immunhistochemistry for MIB-1. RESULTS: In vitro treatment with both compounds significantly suppressed the growth of all cancer cell lines [mean IC50 (3 d) 0.11 and 0.05 μmol/L, respectively], and was associated with hyperacetylation of nucleosomal histone H4, increased expression of p21WAF-1/CIP-1, induction of apoptosis (PARP cleavage), and cell cycle arrest at G2/M checkpoint. After 28 d, NVP-LBH589 significantly reduced tumor mass by 66% (bile duct cancer) and 87% (gallbladder cancer) in vivo in comparison to placebo, and potentiated the efficacy of gemcitabine. Further analysis of the tumor specimens revealed increased apoptosis by TUNEL assay and reduced cell proliferation (MIB-1). CONCLUSION: Our findings suggest that NVP-LBH589 and NVP-LAQ824 are active against human biliary tract cancer in vitro. In addition, NVP-LBH589 demonstrated significant in vivo activity and potentiated the efficacy of gemcitabine. Therefore, further clinical evaluation of this new drug for the treatment of biliary tract cancer is recommended. PMID:17729398

  1. XIAP antagonist embelin inhibited proliferation of cholangiocarcinoma cells.

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    Cody J Wehrkamp

    Full Text Available Cholangiocarcinoma cells are dependent on antiapoptotic signaling for survival and resistance to death stimuli. Recent mechanistic studies have revealed that increased cellular expression of the E3 ubiquitin-protein ligase X-linked inhibitor of apoptosis (XIAP impairs TRAIL- and chemotherapy-induced cytotoxicity, promoting survival of cholangiocarcinoma cells. This study was undertaken to determine if pharmacologic antagonism of XIAP protein was sufficient to sensitize cholangiocarcinoma cells to cell death. We employed malignant cholangiocarcinoma cell lines and used embelin to antagonize XIAP protein. Embelin treatment resulted in decreased XIAP protein levels by 8 hours of treatment with maximal effect at 16 hours in KMCH and Mz-ChA-1 cells. Assessment of nuclear morphology demonstrated a concentration-dependent increase in nuclear staining. Interestingly, embelin induced nuclear morphology changes as a single agent, independent of the addition of TNF-related apoptosis inducing ligand (TRAIL. However, caspase activity assays revealed that increasing embelin concentrations resulted in slight inhibition of caspase activity, not activation. In addition, the use of a pan-caspase inhibitor did not prevent nuclear morphology changes. Finally, embelin treatment of cholangiocarcinoma cells did not induce DNA fragmentation or PARP cleavage. Apoptosis does not appear to contribute to the effects of embelin on cholangiocarcinoma cells. Instead, embelin caused inhibition of cell proliferation and cell cycle analysis indicated that embelin increased the number of cells in S and G2/M phase. Our results demonstrate that embelin decreased proliferation in cholangiocarcinoma cell lines. Embelin treatment resulted in decreased XIAP protein expression, but did not induce or enhance apoptosis. Thus, in cholangiocarcinoma cells the mechanism of action of embelin may not be dependent on apoptosis.

  2. Bithionol inhibits ovarian cancer cell growth In Vitro - studies on mechanism(s) of action

    International Nuclear Information System (INIS)

    Ayyagari, Vijayalakshmi N; Brard, Laurent

    2014-01-01

    Drug resistance is a cause of ovarian cancer recurrence and low overall survival rates. There is a need for more effective treatment approaches because the development of new drug is expensive and time consuming. Alternatively, the concept of ‘drug repurposing’ is promising. We focused on Bithionol (BT), a clinically approved anti-parasitic drug as an anti-ovarian cancer drug. BT has previously been shown to inhibit solid tumor growth in several preclinical cancer models. A better understanding of the anti-tumor effects and mechanism(s) of action of BT in ovarian cancer cells is essential for further exploring its therapeutic potential against ovarian cancer. The cytotoxic effects of BT against a panel of ovarian cancer cell lines were determined by Presto Blue cell viability assay. Markers of apoptosis such as caspases 3/7, cPARP induction, nuclear condensation and mitochondrial transmembrane depolarization were assessed using microscopic, FACS and immunoblotting methods. Mechanism(s) of action of BT such as cell cycle arrest, reactive oxygen species (ROS) generation, autotaxin (ATX) inhibition and effects on MAPK and NF-kB signalling were determined by FACS analysis, immunoblotting and colorimetric methods. BT caused dose dependent cytotoxicity against all ovarian cancer cell lines tested with IC 50 values ranging from 19 μM – 60 μM. Cisplatin-resistant variants of A2780 and IGROV-1 have shown almost similar IC 50 values compared to their sensitive counterparts. Apoptotic cell death was shown by expression of caspases 3/7, cPARP, loss of mitochondrial potential, nuclear condensation, and up-regulation of p38 and reduced expression of pAkt, pNF-κB, pIκBα, XIAP, bcl-2 and bcl-xl. BT treatment resulted in cell cycle arrest at G1/M phase and increased ROS generation. Treatment with ascorbic acid resulted in partial restoration of cell viability. In addition, dose and time dependent inhibition of ATX was observed. BT exhibits cytotoxic effects on various

  3. Listening to Music during Warming-Up Counteracts the Negative Effects of Ramadan Observance on Short-Term Maximal Performance

    Science.gov (United States)

    Baklouti, Hana; Chtourou, Hamdi; Driss, Tarak; Chaouachi, Anis; Chamari, Karim; Souissi, Nizar

    2015-01-01

    Aim The aim of the present study was to examine whether listening to music during warming-up might influence short-term maximal performance (STMP), cognitive anxiety, self-confidence, and enjoyment during Ramadan, and whether these affects might predict STMP. Methods Nine male physical education students (age: 21 ± 1.1 years; height: 1.8 ± 0.04 m; body mass: 83 ± 5 kg) volunteered to participate in the present study. A within-subjects design consisted of four experimental sessions: Two sessions occurred one week before Ramadan and two others took place during Ramadan. They were scheduled at 5 p.m. and were conducted as follows: After a 10-minute warm-up either with or without listening to music, each participant performed a 5-m multiple shuttle run test, after which he was asked to answer items intended to assess his affective state during the experimental task. Results Our findings revealed that STMP was lower during Ramadan than before Ramadan in the no-music condition. Additionally, it was found that STMP was higher in the music condition than in the no-music condition during Ramadan, and that STMP measured before Ramadan did not differ from that measured during Ramadan in the music condition. Regarding affects, the findings revealed that enjoyment was lower during Ramadan than before Ramadan in the music condition, and that cognitive anxiety was lower in the music condition than in the no-music condition before Ramadan. Self-confidence was not influenced by the experimental conditions. Conclusion This study showed that listening to music during warming-up not only would be beneficial for STMP in Ramadan fasters, but also would counteract the negative effects of Ramadan observance on STMP. PMID:26301508

  4. Chronic Exercise Reduces CETP and Mesterolone Treatment Counteracts Exercise Benefits on Plasma Lipoproteins Profile: Studies in Transgenic Mice.

    Science.gov (United States)

    Casquero, Andrea Camargo; Berti, Jairo Augusto; Teixeira, Laura Lauand Sampaio; de Oliveira, Helena Coutinho Franco

    2017-12-01

    Regular exercise and anabolic androgenic steroids have opposing effects on the plasma lipoprotein profile and risk of cardio-metabolic diseases in humans. Studies in humans and animal models show conflicting results. Here, we used a mice model genetically modified to mimic human lipoprotein profile and metabolism. They under-express the endogenous LDL receptor gene (R1) and express a human transgene encoding the cholesteryl ester transfer protein (CETP), normally absent in mice. The present study was designed to evaluate the independent and interactive effects of testosterone supplementation, exercise training and CETP expression on the plasma lipoprotein profile and CETP activity. CETP/R1 and R1 mice were submitted to a 6-week swimming training and mesterolone (MEST) supplementation in the last 3 weeks. MEST treatment increased markedly LDL levels (40%) in sedentary CETP/R1 mice and reduced HDL levels in exercised R1 mice (18%). A multifactorial ANOVA revealed the independent effects of each factor, as follows. CETP expression reduced HDL (21%) and increased non-HDL (15%) fractions. MEST treatment increased the VLDL concentrations (42%) regardless of other interventions. Exercise training reduced triacylglycerol (25%) and free fatty acids (20%), increased both LDL and HDL (25-33%), and reduced CETP (19%) plasma levels. Significant factor interactions showed that the increase in HDL induced by exercise is explained by reducing CETP activity and that MEST blunted the exercise-induced elevation of HDL-cholesterol. These results reinforce the positive metabolic effects of exercise, resolved a controversy about CETP response to exercise and evidenced MEST potency to counteract specific exercise benefits.

  5. Galantamine counteracts development of learning impairment in guinea pigs exposed to the organophosphorus poison soman: Clinical significance

    Science.gov (United States)

    Mamczarz, Jacek; Kulkarni, Girish S.; Pereira, Edna F. R.; Albuquerque, Edson X.

    2017-01-01

    Galantamine, a drug used to treat Alzheimer’s disease, protects guinea pigs against the acute toxicity and lethality of organophosphorus (OP) compounds, including soman. Here, we tested the hypothesis that a single exposure of guinea pigs to 1xLD50 soman triggers cognitive impairments that can be counteracted by galantamine. Thus, animals were injected intramuscularly with saline (0.5 ml/kg) or galantamine (8 mg/kg) and 30 min later injected subcutaneously with soman (26.3 µg/kg) or saline. Cognitive performance was analyzed in the Morris water maze (MWM) four days or three months after the soman challenge. Fifty percent of the saline-injected animals that were challenged with soman survived with mild-to-moderate signs of acute toxicity that subsided within a few hours. These animals showed no learning impairment and no memory retention deficit, when training in the MWM started four days post-soman challenge. In contrast, animals presented significant learning impairment when testing started three months post-challenge. Though the magnitude of the impairment correlated with the severity of the acute toxicity, animals that presented no or only mild signs of toxicity were also learning impaired. All guinea pigs that were treated with galantamine survived the soman challenge with no signs of acute toxicity and learned the MWM task as control animals, regardless of when testing began. Galantamine also prevented memory extinction in both saline-and soman-challenged animals. In conclusion, learning impairment develops months after a single exposure to 1xLD50 soman, and galantamine prevents both the acute toxicity and the delayed cognitive deficits triggered by this OP poison. PMID:21784098

  6. Moderate consumption of beer, red wine and spirits has counteracting effects on plasma antioxidants in middle-aged men.

    Science.gov (United States)

    van der Gaag, M S; van den Berg, R; van den Berg, H; Schaafsma, G; Hendriks, H F

    2000-07-01

    To evaluate the in vivo effects of moderate consumption of red wine, beer and spirits on antioxidants, antioxidant enzymes and antioxidant capacity. Randomized, diet-controlled, cross-over study. Twelve apparently healthy, non-smoking middle-aged men were included; 11 of them completed the study. Each subject consumed four glasses of red wine, beer, spirits and water (negative control) with evening dinner during four successive periods of 3 weeks, daily at the Institute. The total diet was supplied to the subjects and had essential the same composition during these 12 weeks. Neither the enzyme activities of serum glutathion peroxidase, erythrocyte glutathion reductase and superoxide dismutase nor the plasma concentrations of alpha- and gamma-tocopherol, lutein, zeaxantin, beta-cryptoxanthin, lycopene and alpha-carotene were affected. Plasma beta-carotene concentrations were decreased after 3 weeks' consumption of red wine, beer and spirits (40 g alcohol/day) as compared to consumption of water, by 15% (P=0.0005), 11% (P=0.010) and 13% (P=0.003), respectively. Also, plasma ascorbic acid was decreased after beer (15%, P=0.004) and spirits (12%, P=0.030), but not after wine consumption. Serum uric acid concentrations were increased after consumption of beer (15%, Pspirits (8%, P=0.008) and red wine (9%, P=0.003). The overall serum antioxidant capacity, assessed as Trolox equivalent antioxidant capacity (TEAC), was similar for all treatments. Moderate consumption of red wine, beer and spirits has counteracting effects on plasma antioxidant components, resulting in no significant effect on overall antioxidant status. The effects on antioxidant parameters are largely independent of the type of alcoholic beverage, and probably irrelevant to chronic disease risk. Dutch Foundation for Alcohol Research (SAR).

  7. IDH1-mutant cancer cells are sensitive to cisplatin and an IDH1-mutant inhibitor counteracts this sensitivity.

    Science.gov (United States)

    Khurshed, Mohammed; Aarnoudse, Niels; Hulsbos, Renske; Hira, Vashendriya V V; van Laarhoven, Hanneke W M; Wilmink, Johanna W; Molenaar, Remco J; van Noorden, Cornelis J F

    2018-06-07

    Isocitrate dehydrogenase ( IDH1)-1 is mutated in various types of human cancer, and the presence of this mutation is associated with improved responses to irradiation and chemotherapy in solid tumor cells. Mutated IDH1 (IDH1 MUT ) enzymes consume NADPH to produce d-2-hydroxyglutarate (d-2HG) resulting in the decreased reducing power needed for detoxification of reactive oxygen species (ROS), for example. The objective of the current study was to investigate the mechanism behind the chemosensitivity of the widely-used anticancer agent cisplatin in IDH1 MUT cancer cells. Oxidative stress, DNA damage, and mitochondrial dysfunction caused by cisplatin treatment were monitored in IDH1 MUT HCT116 colorectal cancer cells and U251 glioma cells. We found that exposure to cisplatin induced higher levels of ROS, DNA double-strand breaks (DSBs), and cell death in IDH1 MUT cancer cells, as compared with IDH1 wild-type ( IDH1 WT ) cells. Mechanistic investigations revealed that cisplatin treatment dose dependently reduced oxidative respiration in IDH1 MUT cells, which was accompanied by disturbed mitochondrial proteostasis, indicative of impaired mitochondrial activity. These effects were abolished by the IDH1 MUT inhibitor AGI-5198 and were restored by treatment with d-2HG. Thus, our study shows that altered oxidative stress responses and a vulnerable oxidative metabolism underlie the sensitivity of IDH1 MUT cancer cells to cisplatin.-Khurshed, M., Aarnoudse, N., Hulsbos, R., Hira, V. V. V., van Laarhoven, H. W. M., Wilmink, J. W., Molenaar, R. J., van Noorden, C. J. F. IDH1-mutated cancer cells are sensitive to cisplatin and an IDH1-mutant inhibitor counteracts this sensitivity.

  8. Metabolic adaptations may counteract ventilatory adaptations of intermittent hypoxic exposure during submaximal exercise at altitudes up to 4000 m.

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    Martin Faulhaber

    Full Text Available Intermittent hypoxic exposure (IHE has been shown to induce aspects of altitude acclimatization which affect ventilatory, cardiovascular and metabolic responses during exercise in normoxia and hypoxia. However, knowledge on altitude-dependent effects and possible interactions remains scarce. Therefore, we determined the effects of IHE on cardiorespiratory and metabolic responses at different simulated altitudes in the same healthy subjects. Eight healthy male volunteers participated in the study and were tested before and 1 to 2 days after IHE (7 × 1 hour at 4500 m. The participants cycled at 2 submaximal workloads (corresponding to 40% and 60% of peak oxygen uptake at low altitude at simulated altitudes of 2000 m, 3000 m, and 4000 m in a randomized order. Gas analysis was performed and arterial oxygen saturation, blood lactate concentrations, and blood gases were determined during exercise. Additionally baroreflex sensitivity, hypoxic and hypercapnic ventilatory response were determined before and after IHE. Hypoxic ventilatory response was increased after IHE (p<0.05. There were no altitude-dependent changes by IHE in any of the determined parameters. However, blood lactate concentrations and carbon dioxide output were reduced; minute ventilation and arterial oxygen saturation were unchanged, and ventilatory equivalent for carbon dioxide was increased after IHE irrespective of altitude. Changes in hypoxic ventilatory response were associated with changes in blood lactate (r = -0.72, p<0.05. Changes in blood lactate correlated with changes in carbon dioxide output (r = 0.61, p<0.01 and minute ventilation (r = 0.54, p<0.01. Based on the present results it seems that the reductions in blood lactate and carbon dioxide output have counteracted the increased hypoxic ventilatory response. As a result minute ventilation and arterial oxygen saturation did not increase during submaximal exercise at simulated altitudes between 2000 m and 4000 m.

  9. Therapeutic dosages of aspirin counteract the IL-6 induced pro-tumorigenic effects by slowing down the ribosome biogenesis rate

    Science.gov (United States)

    Brighenti, Elisa; Giannone, Ferdinando Antonino; Fornari, Francesca; Onofrillo, Carmine; Govoni, Marzia; Montanaro, Lorenzo; Treré, Davide; Derenzini, Massimo

    2016-01-01

    Chronic inflammation is a risk factor for the onset of cancer and the regular use of aspirin reduces the risk of cancer development. Here we showed that therapeutic dosages of aspirin counteract the pro-tumorigenic effects of the inflammatory cytokine interleukin(IL)-6 in cancer and non-cancer cell lines, and in mouse liver in vivo. We found that therapeutic dosages of aspirin prevented IL-6 from inducing the down-regulation of p53 expression and the acquisition of the epithelial mesenchymal transition (EMT) phenotypic changes in the cell lines. This was the result of a reduction in c-Myc mRNA transcription which was responsible for a down-regulation of the ribosomal protein S6 expression which, in turn, slowed down the rRNA maturation process, thus reducing the ribosome biogenesis rate. The perturbation of ribosome biogenesis hindered the Mdm2-mediated proteasomal degradation of p53, throughout the ribosomal protein-Mdm2-p53 pathway. P53 stabilization hindered the IL-6 induction of the EMT changes. The same effects were observed in livers from mice stimulated with IL-6 and treated with aspirin. It is worth noting that aspirin down-regulated ribosome biogenesis, stabilized p53 and up-regulated E-cadherin expression in unstimulated control cells also. In conclusion, these data showed that therapeutic dosages of aspirin increase the p53-mediated tumor-suppressor activity of the cells thus being in this way able to reduce the risk of cancer onset, either or not linked to chronic inflammatory processes. PMID:27557515

  10. Therapeutic dosages of aspirin counteract the IL-6 induced pro-tumorigenic effects by slowing down the ribosome biogenesis rate.

    Science.gov (United States)

    Brighenti, Elisa; Giannone, Ferdinando Antonino; Fornari, Francesca; Onofrillo, Carmine; Govoni, Marzia; Montanaro, Lorenzo; Treré, Davide; Derenzini, Massimo

    2016-09-27

    Chronic inflammation is a risk factor for the onset of cancer and the regular use of aspirin reduces the risk of cancer development. Here we showed that therapeutic dosages of aspirin counteract the pro-tumorigenic effects of the inflammatory cytokine interleukin(IL)-6 in cancer and non-cancer cell lines, and in mouse liver in vivo. We found that therapeutic dosages of aspirin prevented IL-6 from inducing the down-regulation of p53 expression and the acquisition of the epithelial mesenchymal transition (EMT) phenotypic changes in the cell lines. This was the result of a reduction in c-Myc mRNA transcription which was responsible for a down-regulation of the ribosomal protein S6 expression which, in turn, slowed down the rRNA maturation process, thus reducing the ribosome biogenesis rate. The perturbation of ribosome biogenesis hindered the Mdm2-mediated proteasomal degradation of p53, throughout the ribosomal protein-Mdm2-p53 pathway. P53 stabilization hindered the IL-6 induction of the EMT changes. The same effects were observed in livers from mice stimulated with IL-6 and treated with aspirin. It is worth noting that aspirin down-regulated ribosome biogenesis, stabilized p53 and up-regulated E-cadherin expression in unstimulated control cells also. In conclusion, these data showed that therapeutic dosages of aspirin increase the p53-mediated tumor-suppressor activity of the cells thus being in this way able to reduce the risk of cancer onset, either or not linked to chronic inflammatory processes.

  11. Prevalence and effects of mycotoxins on poultry health and performance, and recent development in mycotoxin counteracting strategies.

    Science.gov (United States)

    Murugesan, G R; Ledoux, D R; Naehrer, K; Berthiller, F; Applegate, T J; Grenier, B; Phillips, T D; Schatzmayr, G

    2015-06-01

    Extensive research over the last couple of decades has made it obvious that mycotoxins are commonly prevalent in majority of feed ingredients. A worldwide mycotoxin survey in 2013 revealed 81% of around 3,000 grain and feed samples analyzed had at least 1 mycotoxin, which was higher than the 10-year average (from 2004 to 2013) of 76% in a total of 25,944 samples. The considerable increase in the number of positive samples in 2013 may be due to the improvements in detection methods and their sensitivity. The recently developed liquid chromatography coupled to (tandem) mass spectrometry allows the inclusion of a high number of analytes and is the most selective, sensitive, and accurate of all the mycotoxin analytical methods. Mycotoxins can affect the animals either individually or additively in the presence of more than 1 mycotoxin, and may affect various organs such as gastrointestinal tract, liver, and immune system, essentially resulting in reduced productivity of the birds and mortality in extreme cases. While the use of mycotoxin binding agents has been a commonly used counteracting strategy, considering the great diversity in the chemical structures of mycotoxins, it is very obvious that there is no single method that can be used to deactivate mycotoxins in feed. Therefore, different strategies have to be combined in order to specifically target individual mycotoxins without impacting the quality of feed. Enzymatic or microbial detoxification, referred to as "biotransformation" or "biodetoxification," utilizes microorganisms or purified enzymes thereof to catabolize the entire mycotoxin or transform or cleave it to less or non-toxic compounds. However, the awareness on the prevalence of mycotoxins, available modern techniques to analyze them, the effects of mycotoxicoses, and the recent developments in the ways to safely eliminate the mycotoxins from the feed are very minimal among the producers. This symposium review paper comprehensively discusses the above

  12. Prevalence and effects of mycotoxins on poultry health and performance, and recent development in mycotoxin counteracting strategies1

    Science.gov (United States)

    Murugesan, G. R.; Ledoux, D. R.; Naehrer, K.; Berthiller, F.; Applegate, T. J.; Grenier, B.; Phillips, T. D.; Schatzmayr, G.

    2015-01-01

    Extensive research over the last couple of decades has made it obvious that mycotoxins are commonly prevalent in majority of feed ingredients. A worldwide mycotoxin survey in 2013 revealed 81% of around 3,000 grain and feed samples analyzed had at least 1 mycotoxin, which was higher than the 10-year average (from 2004 to 2013) of 76% in a total of 25,944 samples. The considerable increase in the number of positive samples in 2013 may be due to the improvements in detection methods and their sensitivity. The recently developed liquid chromatography coupled to (tandem) mass spectrometry allows the inclusion of a high number of analytes and is the most selective, sensitive, and accurate of all the mycotoxin analytical methods. Mycotoxins can affect the animals either individually or additively in the presence of more than 1 mycotoxin, and may affect various organs such as gastrointestinal tract, liver, and immune system, essentially resulting in reduced productivity of the birds and mortality in extreme cases. While the use of mycotoxin binding agents has been a commonly used counteracting strategy, considering the great diversity in the chemical structures of mycotoxins, it is very obvious that there is no single method that can be used to deactivate mycotoxins in feed. Therefore, different strategies have to be combined in order to specifically target individual mycotoxins without impacting the quality of feed. Enzymatic or microbial detoxification, referred to as “biotransformation” or “biodetoxification,” utilizes microorganisms or purified enzymes thereof to catabolize the entire mycotoxin or transform or cleave it to less or non-toxic compounds. However, the awareness on the prevalence of mycotoxins, available modern techniques to analyze them, the effects of mycotoxicoses, and the recent developments in the ways to safely eliminate the mycotoxins from the feed are very minimal among the producers. This symposium review paper comprehensively discusses

  13. Effectiveness of donepezil, rivastigmine, and (+/-)huperzine A in counteracting the acute toxicity of organophosphorus nerve agents: comparison with galantamine.

    Science.gov (United States)

    Aracava, Yasco; Pereira, Edna F R; Akkerman, Miriam; Adler, Michael; Albuquerque, Edson X

    2009-12-01

    Galantamine, a centrally acting cholinesterase (ChE) inhibitor and a nicotinic allosteric potentiating ligand used to treat Alzheimer's disease, is an effective and safe antidote against poisoning with nerve agents, including soman. Here, the effectiveness of galantamine was compared with that of the centrally active ChE inhibitors donepezil, rivastigmine, and (+/-)huperzine A as a pre- and/or post-treatment to counteract the acute toxicity of soman. In the first set of experiments, male prepubertal guinea pigs were treated intramuscularly with one of the test drugs and 30 min later challenged with 1.5 x LD(50) soman (42 microg/kg s.c.). All animals that were pretreated with galantamine (6-8 mg/kg), 3 mg/kg donepezil, 6 mg/kg rivastigmine, or 0.3 mg/kg (+/-)huperzine A survived the soman challenge, provided that they were also post-treated with atropine (10 mg/kg i.m.). However, only galantamine was well tolerated. In subsequent experiments, the effectiveness of specific treatment regimens using 8 mg/kg galantamine, 3 mg/kg donepezil, 6 mg/kg rivastigmine, or 0.3 mg/kg (+/-)huperzine A was compared in guinea pigs challenged with soman. In the absence of atropine, only galantamine worked as an effective and safe pretreatment in animals challenged with 1.0 x LD(50) soman. Galantamine was also the only drug to afford significant protection when given to guinea pigs after 1.0 x LD(50) soman. Finally, all test drugs except galantamine reduced the survival of the animals when administered 1 or 3 h after the challenge with 0.6 or 0.7 x LD(50) soman. Thus, galantamine emerges as a superior antidotal therapy against the toxicity of soman.

  14. Inhibition of SIRT1 combined with gemcitabine therapy for pancreatic carcinoma

    Directory of Open Access Journals (Sweden)

    Gong DJ

    2013-07-01

    Full Text Available Dao-Jun Gong,1 Jia-Min Zhang,1 Min Yu,1 Bo Zhuang,1 Qing-Qu Guo21Department of Hepatobiliary-Pancreatic Surgery, Jinhua Hospital of Zhejiang University, Jinhua, People's Republic of China; 2Department of Surgery, Second Affiliated Hospital of Zhejiang University College of Medicine, Hangzhou, People's Republic of ChinaBackground: Pancreatic carcinoma possesses one of the highest lethality rates, highest drug-resistance, and highest incidence rates. The objective of this research was to enhance the efficacy and drug-resistance for pancreatic carcinoma by using inhibition of SIRT1 combined with gemcitabine therapy methods.Methods: Three pancreatic carcinoma cells (PANC-1 cells, BxPC-3 cells, and SW1990 cells received treatment with physiological saline, inhibition of SIRT1, gemcitabine, and combination therapy with inhibition of SIRT1 and gemcitabine in vitro; then BxPC-3 pancreatic cancer xenogeneic mice also received treatment with physiological saline, inhibition of SIRT1, gemcitabine, and combination therapy with inhibition of SIRT1 and gemcitabine in vivo.Results: The cleaved poly ADP ribose polymerase (PARP-1 effect of drug in pancreatic carcinoma cells was significantly different (P < 0.05 and the efficacy in descending order was the combination therapy with inhibition of SIRT1 and gemcitabine, inhibition of SIRT1, and gemcitabine. The BxPC-3 pancreatic cancer xenogeneic mice model received treatment with physiological saline, inhibition of SIRT1, gemcitabine, and combination therapy with inhibition of SIRT1 and gemcitabine in vivo and the results showed that the tumor volumes decreased and the survival rate within 45 days increased according to the order of the given drugs and the difference was significant (P < 0.05.Conclusion: Combination therapy with inhibition of SIRT1 and gemcitabine could improve efficacy and survival time in a BxPC-3 pancreatic cancer xenogeneic mice model, compared with single inhibition of SIRT1, or single

  15. National Nuclear Center of the Republic of Kazakhstan in the system of nuclear terrorism counteractions at Kazakhstan territory

    International Nuclear Information System (INIS)

    Tukhvatulin, Sh.T.; Zhotabayev, Zh.R.; Azarov, V.A.; Silayev, M.E.

    2002-01-01

    authorities and reduction of their power and capabilities, a general threat of terrorist acts at companies using nuclear and radiation technologies has increased. In addition, due to its geographical position, the Republic of Kazakhstan is a transit state between Europe and Asia. That is why, numerous cases of transit shipment and sale attempts of nuclear materials from other states including the former SU republics were recorded here (e.g., fuel elements from Chernobyl NPP). The above demonstrates an unprejudiced necessity of arranging an efficient counteraction system against nuclear terrorism in the Republic of Kazakhstan. The current Kazakhstan system of nuclear and radioactive materials control does not meet the present-day requirements. Its efficiency and capabilities should obviously be increased. This will allow avoiding considerable losses by existing economical figures and potential political losses in the international relations. After collapse of the Soviet Union, major nuclear research institutions and branches left at the territory of independent Kazakhstan were consolidated into a uniform organization: the Republican State Enterprise National Nuclear Center of the Republic of Kazakhstan. At present, four institutions are functioning under the aegis of the Center. By this time, many directions of the Center activity are related or contribute to potential nuclear terrorism counteractions. Among the wide range of these activities, the major ones are worth mentioning, both performed and in process: The project on elimination of the last nuclear device at the former Semipalatinsk Test-Site territory; The projects on weapons of mass destruction infrastructure elimination. In particular, projects related to closure and permanent sealing of defense tunnels used and prepared for nuclear weapon testing; The project on irreversible shut-down and decommissioning with following long-term conservation of BN-350 fast power reactor in Aktau; The project on the high plutonium

  16. [Decursin reduces reactive oxygen species and inhibits cisplatin-induced apoptosis in rat renal tubular epithelial cells].

    Science.gov (United States)

    Li, Cuiqiong; Li, Jianchun; Fan, Junming; Meng, Lifeng; Cao, Ling

    2017-10-01

    Objective To study the mechanism underlying the inhibitory effect of decursin on the apoptosis of rat renal tubular epithelial cells NRK-52E induced by cisplatin. Methods First, CCK-8 assay was used to detect the effects of 0, 10, 20, 40, 80, 100, 150, 200 μmol/L decursin and 0, 5, 10, 20, 30, 40, 50 μg/mL cispatin treatment for 24 hours on cell proliferation in NRK-52E cells via determining the half inhibitory concentration (IC 50 ). Then, NRK-52E cells were stimulated with 20 μg/mL cisplatin combined with 10, 50, 100 μmol/L decursin, and cell activity was detected by CCK-8 assay. The cells were divided into normal control group, 20 μg/mL cisplatin stimulation group, and 10, 50, 100 μmol/L decursin treated groups. Cell morphological changes was observed under inverted microscope, morphological changes of nucleus was detected by DAPI staining, cell apoptosis was detected by flow cytometry, the level of intracellular ROS was detected by DCFH-DA staining, and the apoptosis marker proteins cleaved-caspase-3 and cleaved-PARP were examined by Western blot analysis. Results Compared with the normal control group, cisplatin significantly inhibited the activity of the cells, and IC 50 was about 20 μg/mL; compared with the model group, in the decursin pretreatment groups, the level of intracellular ROS decreased remarkably, the expressions of cleaved-casspase-3 and cleaved-PARP proteins were reduced, and cell apoptosis was depressed. Conclusion Decursin can decrease the intracellular ROS level and inhibit the apoptosis of NRK-52E cells induced by cisplatin.

  17. Effusanin E suppresses nasopharyngeal carcinoma cell growth by inhibiting NF-κB and COX-2 signaling.

    Directory of Open Access Journals (Sweden)

    Mingzhu Zhuang

    Full Text Available Rabdosia serra is well known for its antibacterial, anti-inflammatory and antitumor activities, but no information has been available for the active compounds derived from this plant in inhibiting human nasopharyngeal carcinoma (NPC cell growth. In this study, we isolated and purified a natural diterpenoid from Rabdosia serra and identified its chemical structure as effusanin E and elucidated its underlying mechanism of action in inhibiting NPC cell growth. Effusanin E significantly inhibited cell proliferation and induced apoptosis in NPC cells. Effusanin E also induced the cleavage of PARP, caspase-3 and -9 proteins and inhibited the nuclear translocation of p65 NF-κB proteins. Moreover, effusanin E abrogated the binding of NF-κB to the COX-2 promoter, thereby inhibiting the expression and promoter activity of COX-2. Pretreatment with a COX-2 or NF-κB-selective inhibitor (celecoxib or ammonium pyrrolidinedithiocarbamate had an additive effect on the effusanin E-mediated inhibition of proliferation, while pretreatment with an activator of NF-κB/COX-2 (lipopolysaccharides abrogated the effusanin E-mediated inhibition of proliferation. Effusanin E also significantly suppressed tumor growth in a xenograft mouse model without obvious toxicity, furthermore, the expression of p50 NF-κB and COX-2 were down-regulated in the tumors of nude mice. These data suggest that effusanin E suppresses p50/p65 proteins to down-regulate COX-2 expression, thereby inhibiting NPC cell growth. Our findings provide new insights into exploring effusanin E as a potential therapeutic compound for the treatment of human nasopharyngeal carcinoma.

  18. ROS accumulation and IGF-IR inhibition contribute to fenofibrate/PPARα -mediated inhibition of Glioma cell motility in vitro

    Directory of Open Access Journals (Sweden)

    Del Valle Luis

    2010-06-01

    Full Text Available Abstract Background Glioblastomas are characterized by rapid cell growth, aggressive CNS infiltration, and are resistant to all known anticancer regimens. Recent studies indicate that fibrates and statins possess anticancer potential. Fenofibrate is a potent agonist of peroxisome proliferator activated receptor alpha (PPARα that can switch energy metabolism from glycolysis to fatty acid β-oxidation, and has low systemic toxicity. Fenofibrate also attenuates IGF-I-mediated cellular responses, which could be relevant in the process of glioblastoma cell dispersal. Methods The effects of fenofibrate on Glioma cell motility, IGF-I receptor (IGF-IR signaling, PPARα activity, reactive oxygen species (ROS metabolism, mitochondrial potential, and ATP production were analyzed in human glioma cell lines. Results Fenofibrate treatment attenuated IGF-I signaling responses and repressed cell motility of LN-229 and T98G Glioma cell lines. In the absence of fenofibrate, specific inhibition of the IGF-IR had only modest effects on Glioma cell motility. Further experiments revealed that PPARα-dependent accumulation of ROS is a strong contributing factor in Glioma cell lines responses to fenofibrate. The ROS scavenger, N-acetyl-cysteine (NAC, restored cell motility, improved mitochondrial potential, and increased ATP levels in fenofibrate treated Glioma cell lines. Conclusions Our results indicate that although fenofibrate-mediated inhibition of the IGF-IR may not be sufficient in counteracting Glioma cell dispersal, PPARα-dependent metabolic switch and the resulting ROS accumulation strongly contribute to the inhibition of these devastating brain tumor cells.

  19. Ursodeoxycholic acid counteracts celecoxib in reduction of duodenal polyps in patients with familial adenomatous polyposis: a multicentre, randomized controlled trial

    Science.gov (United States)

    2013-01-01

    polyp density in patients with FAP, and unexpectedly, high dose UDCA co-treatment counteracts this effect. The benefit of long term use of celecoxib for duodenal cancer prevention needs to be weighed against the (risk of) adverse events. Trial registration http://ClinicalTrials.gov, identifier NCT00808743 PMID:23919274

  20. KAEMPFEROL, A FLAVONOID COMPOUND FROM GYNURA MEDICA INDUCED APOPTOSIS AND GROWTH INHIBITION IN MCF-7 BREAST CANCER CELL.

    Science.gov (United States)

    Yi, Xiaofang; Zuo, Jiangcheng; Tan, Chao; Xian, Sheng; Luo, Chunhua; Chen, Sai; Yu, Liangfang; Luo, Yucheng

    2016-01-01

    Kaempferol, a natural flavonoid, has been shown to induce cancer cell apoptosis and cell growth inhibition in several tumors. Previously we have conducted a full investigation on the chemical constituents of Gynura medica , kaempferol and its glycosides are the major constituents of G. medica . Here we investigated the growth inhibition and apoptosis induction effect of kaempferol extracted from G. medica . The inhibition effects of kaempferol were evaluated by MTS assay and soft agar colony formation assay. Fluorescence staining and western blotting were be used to study the apoptosis. The structure was identified by 1 H- NMR), 13 C-NMR and ESI-MS analyses. Our results showed that kaempferol's inhibition of MCF-7 breast cancer cell growth may through inducing apoptosis and downregulation of Bcl2 expression. Kaempferol is a promising cancer preventive and therapeutic agent for breast cancer. List of non-standard abbreviations: MTS: 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, HPLC: High-performance liquid chromatography, NMR: Nuclear Magnetic Resonance, ESI-MS Electrospray Ionization Mass Spectral, PARP: Poly ADP-ribose polymerase.

  1. Raddeanin A induces human gastric cancer cells apoptosis and inhibits their invasion in vitro

    International Nuclear Information System (INIS)

    Xue, Gang; Zou, Xi; Zhou, Jin-Yong; Sun, Wei; Wu, Jian; Xu, Jia-Li; Wang, Rui-Ping

    2013-01-01

    Highlights: •Raddeanin A is a triterpenoid saponin in herb medicine Anemone raddeana Regel. •Raddeanin A can inhibit 3 kinds of gastric cancer cells’ proliferation and invasion. •Caspase-cascades’ activation indicates apoptosis induced by Raddeanin A. •MMPs, RECK, Rhoc and E-cad are involved in Raddeanin A-induced invasion inhibition. -- Abstract: Raddeanin A is one of the triterpenoid saponins in herbal medicine Anemone raddeana Regel which was reported to suppress the growth of liver and lung cancer cells. However, little was known about its effect on gastric cancer (GC) cells. This study aimed to investigate its inhibitory effect on three kinds of different differentiation stage GC cells (BGC-823, SGC-7901 and MKN-28) in vitro and the possible mechanisms. Proliferation assay and flow cytometry demonstrated Raddeanin A’s dose-dependent inhibitory effect and determined its induction of cells apoptosis, respectively. Transwell assay, wounding heal assay and cell matrix adhesion assay showed that Raddeanin A significantly inhibited the abilities of the invasion, migration and adhesion of the BGC-823 cells. Moreover, quantitative real time PCR and Western blot analysis found that Raddeanin A increased Bax expression while reduced Bcl-2, Bcl-xL and Survivin expressions and significantly activated caspase-3, caspase-8, caspase-9 and poly-ADP ribose polymerase (PARP). Besides, Raddeanin A could also up-regulate the expression of reversion inducing cysteine rich protein with Kazal motifs (RECK), E-cadherin (E-cad) and down-regulate the expression of matrix metalloproteinases-2 (MMP-2), MMP-9, MMP-14 and Rhoc. In conclusion, Raddeanin A inhibits proliferation of human GC cells, induces their apoptosis and inhibits the abilities of invasion, migration and adhesion, exhibiting potential to become antitumor drug

  2. Raddeanin A induces human gastric cancer cells apoptosis and inhibits their invasion in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Gang [Department of Oncology, Nanjing University of Chinese Medicine, Nanjing (China); Zou, Xi [Department of Oncology, Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing (China); Zhou, Jin-Yong [Laboratory Center, Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing (China); Sun, Wei [Department of Oncology, Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing (China); Wu, Jian [Laboratory Center, Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing (China); Xu, Jia-Li [Department of Oncology, Nanjing University of Chinese Medicine, Nanjing (China); Wang, Rui-Ping, E-mail: ruipingwang61@hotmail.com [Department of Oncology, Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing (China)

    2013-09-20

    Highlights: •Raddeanin A is a triterpenoid saponin in herb medicine Anemone raddeana Regel. •Raddeanin A can inhibit 3 kinds of gastric cancer cells’ proliferation and invasion. •Caspase-cascades’ activation indicates apoptosis induced by Raddeanin A. •MMPs, RECK, Rhoc and E-cad are involved in Raddeanin A-induced invasion inhibition. -- Abstract: Raddeanin A is one of the triterpenoid saponins in herbal medicine Anemone raddeana Regel which was reported to suppress the growth of liver and lung cancer cells. However, little was known about its effect on gastric cancer (GC) cells. This study aimed to investigate its inhibitory effect on three kinds of different differentiation stage GC cells (BGC-823, SGC-7901 and MKN-28) in vitro and the possible mechanisms. Proliferation assay and flow cytometry demonstrated Raddeanin A’s dose-dependent inhibitory effect and determined its induction of cells apoptosis, respectively. Transwell assay, wounding heal assay and cell matrix adhesion assay showed that Raddeanin A significantly inhibited the abilities of the invasion, migration and adhesion of the BGC-823 cells. Moreover, quantitative real time PCR and Western blot analysis found that Raddeanin A increased Bax expression while reduced Bcl-2, Bcl-xL and Survivin expressions and significantly activated caspase-3, caspase-8, caspase-9 and poly-ADP ribose polymerase (PARP). Besides, Raddeanin A could also up-regulate the expression of reversion inducing cysteine rich protein with Kazal motifs (RECK), E-cadherin (E-cad) and down-regulate the expression of matrix metalloproteinases-2 (MMP-2), MMP-9, MMP-14 and Rhoc. In conclusion, Raddeanin A inhibits proliferation of human GC cells, induces their apoptosis and inhibits the abilities of invasion, migration and adhesion, exhibiting potential to become antitumor drug.

  3. Pharmacological Inhibition of poly(ADP-ribose) polymerases improves fitness and mitochondrial function in skeletal muscle.

    NARCIS (Netherlands)

    Pirinen, E.; Canto, C.; Jo, Y.S.; Morato, L.; Zhang, H.; Menzies, K.J.; Williams, E.G.; Mouchiroud, L.; Moullan, N.; Hagberg, C.; Li, W.; Timmers, S.; Imhof, R.; Verbeek, J.; Pujol, A.; Loon, B. van; Viscomi, C.; Zeviani, M.; Schrauwen, P.; Sauve, A.A.; Schoonjans, K.; Auwerx, J.

    2014-01-01

    We previously demonstrated that the deletion of the poly(ADP-ribose)polymerase (Parp)-1 gene in mice enhances oxidative metabolism, thereby protecting against diet-induced obesity. However, the therapeutic use of PARP inhibitors to enhance mitochondrial function remains to be explored. Here, we show

  4. Cytoprotective effects of Glycyrrhizae radix extract and its active component liquiritigenin against cadmium-induced toxicity (effects on bad translocation and cytochrome c-mediated PARP cleavage)

    International Nuclear Information System (INIS)

    Kim, Sang Chan; Byun, Sung Hui; Yang, Chae Ha; Kim, Chul Young; Kim, Jin Woong; Kim, Sang Geon

    2004-01-01

    Glycyrrhizae radix has been popularly used as one of the oldest and most frequently employed botanicals in herbal medicine in Asian countries, and currently occupies an important place in food products. Cadmium (Cd) induces both apoptotic and non-apoptotic cell death, in which alterations in cellular sulfhydryls participate. In the present study, we determined the effects of G. radix extract (GRE) and its representative active components on cell death induced by Cd and explored the mechanistic basis of cytoprotective effects of G. radix. Incubation of H4IIE cells with GRE inhibited cell death induced by 10 μM Cd. Also, GRE effectively blocked Cd (1 μM)-induced cell death potentiated by buthionine sulfoximine (BSO) without restoration of cellular GSH. GRE prevented both apoptotic and non-apoptotic cell injury induced by Cd (10 μM) or Cd (0.3-1 μM) + BSO. Inhibition of Cd-induced cell injury by pretreatment of cells with GRE suggested that the cytoprotective effect result from alterations in the levels of the protein(s) responsible for cell viability. GRE inhibited mitochondrial Bad translocation by Cd or Cd+BSO, and caused restoration of mitochondrial Bcl xL and cytochrome c levels. Cd-induced poly(ADP-ribose)polymerase cleavage in control cells or in cells deprived of sulfhydryls was prevented by GRE treatment. Among the major components present in GRE, liquiritigenin, but not liquiritin, isoliquiritigenin or glycyrrhizin, exerted cytoprotective effect. These results demonstrated that GRE blocked Cd-induced cell death by inhibiting the apoptotic processes involving translocation of Bad into mitochondria, decreases in mitochondrial Bcl xL and cytochrome c, and poly(ADP-ribose)polymerase cleavage

  5. Chloroquine and hydroxychloroquine inhibit bladder cancer cell growth by targeting basal autophagy and enhancing apoptosis

    Directory of Open Access Journals (Sweden)

    Yi-Chia Lin

    2017-05-01

    Full Text Available Chloroquine (CQ and hydroxychloroquine (HCQ, two antimalarial drugs, are suggested to have potential anticancer properties. in the present study, we investigated the effects of CQ and HCQ on cell growth of bladder cancer with emphasis on autophagy inhibition and apoptosis induction in vitro. The results showed that CQ and HCQ inhibited the proliferation of multiple human bladder cell lines (including RT4, 5637, and T24 in a time- and dose-dependent fashion, especially in advanced bladder cancer cell lines (5637 and T24 compared to immortalized uroepithelial cells (SV-Huc-1 or other reference cancer cell lines (PC3 and MCF-7. We found that 24-hour treatment of CQ or HCQ significantly decreased the clonogenic formation in 5637 and T24 cells compared to SV-Huc-1. As human bladder cancer tumor exhibits high basal level of autophagic activities, we detected the autophagic flux in cells treated with CQ and HCQ, showing an alternation in LC3 flux in CQ- or HCQ-treated cells. Moreover, bladder cancer cells treated with CQ and HCQ underwent apoptosis, resulting in increased caspase 3/7 activities, increased level of cleaved poly(ADP-ribose polymerase (PARP, caspase 3, and DNA fragmentation. Given these results, targeting autophagy with CQ and HCQ represents an effective cancer therapeutic strategy against human bladder cancer.

  6. Chloroquine and hydroxychloroquine inhibit bladder cancer cell growth by targeting basal autophagy and enhancing apoptosis.

    Science.gov (United States)

    Lin, Yi-Chia; Lin, Ji-Fan; Wen, Sheng-I; Yang, Shan-Che; Tsai, Te-Fu; Chen, Hung-En; Chou, Kuang-Yu; Hwang, Thomas I-Sheng

    2017-05-01

    Chloroquine (CQ) and hydroxychloroquine (HCQ), two antimalarial drugs, are suggested to have potential anticancer properties. in the present study, we investigated the effects of CQ and HCQ on cell growth of bladder cancer with emphasis on autophagy inhibition and apoptosis induction in vitro. The results showed that CQ and HCQ inhibited the proliferation of multiple human bladder cell lines (including RT4, 5637, and T24) in a time- and dose-dependent fashion, especially in advanced bladder cancer cell lines (5637 and T24) compared to immortalized uroepithelial cells (SV-Huc-1) or other reference cancer cell lines (PC3 and MCF-7). We found that 24-hour treatment of CQ or HCQ significantly decreased the clonogenic formation in 5637 and T24 cells compared to SV-Huc-1. As human bladder cancer tumor exhibits high basal level of autophagic activities, we detected the autophagic flux in cells treated with CQ and HCQ, showing an alternation in LC3 flux in CQ- or HCQ-treated cells. Moreover, bladder cancer cells treated with CQ and HCQ underwent apoptosis, resulting in increased caspase 3/7 activities, increased level of cleaved poly(ADP-ribose) polymerase (PARP), caspase 3, and DNA fragmentation. Given these results, targeting autophagy with CQ and HCQ represents an effective cancer therapeutic strategy against human bladder cancer. Copyright © 2017. Published by Elsevier Taiwan.

  7. Solena amplexicaulis induces cell cycle arrest, apoptosis and inhibits angiogenesis in hepatocarcinoma cells and HUVECs.

    Science.gov (United States)

    Ren, Jie; Xu, Yuan Yuan; Jiang, He Fei; Yang, Meng; Huang, Qian Hui; Yang, Jie; Hu, Kun; Wei, Kun

    2014-01-01

    Solena amplexicaulis (Lam.) Gandhi (SA) has been used as a traditional medicine for the treatment of dysentery, multiple abscess, gastralgia, urethritis, and eczema in the minority area of China. This study was aimed to examine the cell proliferation inhibitory activity of the SA extract (SACE) and its mechanism of action in human hepatoma cell line (HepG2) and evaluate its anti-angiogenesis activity in human umbilical vein endothelial cell line (HUVEC). SACE could inhibit the growth of HepG2 cells in a dose- and time-dependent manner. FCM analysis showed that SACE could induce G2/M phase arrest, cell apoptosis, the mitochondrial membrane potential loss (ΔΨm) and increase the production of intracellular ROS of HepG2 cells. After treatment with SACE, topical morphological changes of apoptotic body formation, obvious increase of apoptosis-related protein expressions, such as Bax, cytochrome c, caspase-3, PARP-1, and decrease of Bcl-2, procaspase-9 protein expressions were observed at the same time. Moreover, SACE caused the significant inhibition of endothelial cell migration and tube formation in HUVEC cells. The results suggested that SACE could act as an angiogenesis inhibitor and induce cell apoptosis via a caspase-dependent mitochondrial pathway. Therefore, SACE could be a potent candidate for the prevention and treatment of liver cancer.

  8. In vivo inhibition of the mitochondrial H+-ATP synthase in neurons promotes metabolic preconditioning.

    Science.gov (United States)

    Formentini, Laura; Pereira, Marta P; Sánchez-Cenizo, Laura; Santacatterina, Fulvio; Lucas, José J; Navarro, Carmen; Martínez-Serrano, Alberto; Cuezva, José M

    2014-04-01

    A key transducer in energy conservation and signaling cell death is the mitochondrial H(+)-ATP synthase. The expression of the ATPase inhibitory factor 1 (IF1) is a strategy used by cancer cells to inhibit the activity of the H(+)-ATP synthase to generate a ROS signal that switches on cellular programs of survival. We have generated a mouse model expressing a mutant of human IF1 in brain neurons to assess the role of the H(+)-ATP synthase in cell death in vivo. The expression of hIF1 inhibits the activity of oxidative phosphorylation and mediates the shift of neurons to an enhanced aerobic glycolysis. Metabolic reprogramming induces brain preconditioning affording protection against quinolinic acid-induced excitotoxicity. Mechanistically, preconditioning involves the activation of the Akt/p70S6K and PARP repair pathways and Bcl-xL protection from cell death. Overall, our findings provide the first in vivo evidence highlighting the H(+)-ATP synthase as a target to prevent neuronal cell death.

  9. Inhibition of lactation.

    Science.gov (United States)

    Llewellyn-Jones, D

    1975-01-01

    The mechanism and hormonal regulation of lactation is explained and illustrated with a schematic representation. Circulating estrogen above a critical amount seems to be the inhibitory factor controlling lactation during pregnancy. Once delivery occurs, the level of estrogen falls, that of prolactin rises, and lactation begins. Nonsuckling can be used to inhibit lactation. Estrogens can also be used to inhibit lactation more quickly and with less pain. The reported association between estrogens and puerperal thromboembolism cannot be considered conclusive due to defects in the reporting studies. There is no reason not to use estrogens in lactation inhibition except for women over 35 who experienced a surgical delivery. Alternative therapy is available for these women. The recently-developed drug, brom-ergocryptine, may replace other methods of lactation inhibition.

  10. BET bromodomain inhibition rescues erythropoietin differentiation of human erythroleukemia cell line UT7

    International Nuclear Information System (INIS)

    Goupille, Olivier; Penglong, Tipparat; Lefèvre, Carine; Granger, Marine; Kadri, Zahra; Fucharoen, Suthat; Maouche-Chrétien, Leila; Leboulch, Philippe; Chrétien, Stany

    2012-01-01

    Highlights: ► UT7 erythroleukemia cells are known to be refractory to differentiate. ► Brief JQ1 treatment initiates the first steps of erythroid differentiation program. ► Engaged UT7 cells then maturate in the presence of erythropoietin. ► Sustained JQ1 treatment inhibits both proliferation and erythroid differentiation. -- Abstract: Malignant transformation is a multistep process requiring oncogenic activation, promoting cellular proliferation, frequently coupled to inhibition of terminal differentiation. Consequently, forcing the reengagement of terminal differentiation of transformed cells coupled or not with an inhibition of their proliferation is a putative therapeutic approach to counteracting tumorigenicity. UT7 is a human leukemic cell line able to grow in the presence of IL3, GM-CSF and Epo. This cell line has been widely used to study Epo-R/Epo signaling pathways but is a poor model for erythroid differentiation. We used the BET bromodomain inhibition drug JQ1 to target gene expression, including that of c-Myc. We have shown that only 2 days of JQ1 treatment was required to transitory inhibit Epo-induced UT7 proliferation and to restore terminal erythroid differentiation. This study highlights the importance of a cellular erythroid cycle break mediated by c-Myc inhibition before initiation of the erythropoiesis program and describes a new model for BET bromodomain inhibitor drug application.

  11. BET bromodomain inhibition rescues erythropoietin differentiation of human erythroleukemia cell line UT7

    Energy Technology Data Exchange (ETDEWEB)

    Goupille, Olivier [CEA, Institute of Emerging Diseases and Innovative Therapies, Fontenay-aux-Roses (France); UMR INSERM U.962, University Paris XI, CEA, Fontenay-aux-Roses (France); Penglong, Tipparat [CEA, Institute of Emerging Diseases and Innovative Therapies, Fontenay-aux-Roses (France); UMR INSERM U.962, University Paris XI, CEA, Fontenay-aux-Roses (France); Thalassemia Research Center and Department of Clinical Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University (Thailand); Lefevre, Carine; Granger, Marine; Kadri, Zahra [CEA, Institute of Emerging Diseases and Innovative Therapies, Fontenay-aux-Roses (France); UMR INSERM U.962, University Paris XI, CEA, Fontenay-aux-Roses (France); Fucharoen, Suthat [Thalassemia Research Center and Department of Clinical Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University (Thailand); Maouche-Chretien, Leila [CEA, Institute of Emerging Diseases and Innovative Therapies, Fontenay-aux-Roses (France); UMR INSERM U.962, University Paris XI, CEA, Fontenay-aux-Roses (France); Leboulch, Philippe [CEA, Institute of Emerging Diseases and Innovative Therapies, Fontenay-aux-Roses (France); UMR INSERM U.962, University Paris XI, CEA, Fontenay-aux-Roses (France); Genetics Division, Department of Medicine, Brigham and Women' s Hospital and Harvard Medical School, Boston, MA (United States); Chretien, Stany, E-mail: stany.chretien@cea.fr [CEA, Institute of Emerging Diseases and Innovative Therapies, Fontenay-aux-Roses (France); UMR INSERM U.962, University Paris XI, CEA, Fontenay-aux-Roses (France)

    2012-12-07

    Highlights: Black-Right-Pointing-Pointer UT7 erythroleukemia cells are known to be refractory to differentiate. Black-Right-Pointing-Pointer Brief JQ1 treatment initiates the first steps of erythroid differentiation program. Black-Right-Pointing-Pointer Engaged UT7 cells then maturate in the presence of erythropoietin. Black-Right-Pointing-Pointer Sustained JQ1 treatment inhibits both proliferation and erythroid differentiation. -- Abstract: Malignant transformation is a multistep process requiring oncogenic activation, promoting cellular proliferation, frequently coupled to inhibition of terminal differentiation. Consequently, forcing the reengagement of terminal differentiation of transformed cells coupled or not with an inhibition of their proliferation is a putative therapeutic approach to counteracting tumorigenicity. UT7 is a human leukemic cell line able to grow in the presence of IL3, GM-CSF and Epo. This cell line has been widely used to study Epo-R/Epo signaling pathways but is a poor model for erythroid differentiation. We used the BET bromodomain inhibition drug JQ1 to target gene expression, including that of c-Myc. We have shown that only 2 days of JQ1 treatment was required to transitory inhibit Epo-induced UT7 proliferation and to restore terminal erythroid differentiation. This study highlights the importance of a cellular erythroid cycle break mediated by c-Myc inhibition before initiation of the erythropoiesis program and describes a new model for BET bromodomain inhibitor drug application.

  12. Aerosolized 3-bromopyruvate inhibits lung tumorigenesis without causing liver toxicity.

    Science.gov (United States)

    Zhang, Qi; Pan, Jing; North, Paula E; Yang, Shoua; Lubet, Ronald A; Wang, Yian; You, Ming

    2012-05-01

    3-Bromopyruvate, an alkylating agent and a well-known inhibitor of energy metabolism, has been proposed as a specific anticancer agent. However, the chemopreventive effect of 3-bromopyruvate in lung tumorigenesis has not been tested. In this study, we investigated the chemopreventive activity of 3-bromopyruvate in a mouse lung tumor model. Benzo(a)pyrene was used to induce lung tumors, and 3-bromopyruvate was administered by oral gavage to female A/J mice. We found that 3-bromopyruvate significantly decreased tumor multiplicity and tumor load by 58% and 83%, respectively, at a dose of 20 mg/kg body weight by gavage. Due to the known liver toxicity of 3-bromopyruvate in animal models given large doses of 3-bromopyruvate, confirmed in this study, we decided to test the chemopreventive activity of aerosolized 3-bromopyruvate in the same lung tumor model. As expected, aerosolized 3-bromopyruvate similarly significantly decreased tumor multiplicity and tumor load by 49% and 80%, respectively, at a dose of 10 mg/mL by inhalation. Interestingly, the efficacy of aerosolized 3-bromopyruvate did not accompany any liver toxicity indicating that it is a safer route of administering this compound. Treatment with 3-bromopyruvate increased immunohistochemical staining for cleaved caspase-3, suggesting that the lung tumor inhibitory effects of 3-bromopyruvate were through induction of apoptosis. 3-Bromopyruvate also dissociated hexokinase II from mitochondria, reduced hexokinase activity, and blocked energy metabolism in cancer cells, finally triggered cancer cell death and induced apoptosis through caspase-3, and PARP in human lung cancer cell line. The ability of 3-bromopyruvate to inhibit mouse lung tumorigenesis, in part through induction of apoptosis, merits further investigation of this compound as a chemopreventive agent for human lung cancer.

  13. Effect of tolvaptan on renal water and sodium excretion and blood pressure during nitric oxide inhibition

    DEFF Research Database (Denmark)

    Therwani, Safa Al; Rosenbæk, Jeppe Bakkestrøm; Mose, Frank Holden

    2017-01-01

    BACKGROUND: Tolvaptan is a selective vasopressin receptor antagonist. Nitric Oxide (NO) promotes renal water and sodium excretion, but the effect is unknown in the nephron's principal cells. In a dose-response study, we measured the effect of tolvaptan on renal handling of water and sodium....... CONCLUSIONS: During baseline, fractional excretion of sodium was unchanged. During tolvaptan with NO-inhibition, renal water excretion was reduced dose dependently, and renal sodium excretion was reduced unrelated to the dose, partly via an AVP dependent mechanism. Thus, tolvaptan antagonized the reduction...... in renal water and sodium excretion during NO-inhibition. Most likely, the lack of decrease in AQP2 excretion by tolvaptan could be attributed to a counteracting effect of the high level of p-AVP....

  14. SERINC as a Restriction Factor to Inhibit Viral Infectivity and the Interaction with HIV

    Directory of Open Access Journals (Sweden)

    Gracia Viviana Gonzalez-Enriquez

    2017-01-01

    Full Text Available The serine incorporator 5 (SERINC5 is a recently discovered restriction factor that inhibits viral infectivity by preventing fusion. Retroviruses have developed strategies to counteract the action of SERINC5, such as the expression of proteins like negative regulatory factor (Nef, S2, and glycosylated Gag (glycoGag. These accessory proteins downregulate SERINC5 from the plasma membrane for subsequent degradation in the lysosomes. The observed variability in the action of SERINC5 suggests the participation of other elements like the envelope glycoprotein (Env that modulates susceptibility of the virus towards SERINC5. The exact mechanism by which SERINC5 inhibits viral fusion has not yet been determined, although it has been proposed that it increases the sensitivity of the Env by exposing regions which are recognized by neutralizing antibodies. More studies are needed to understand the role of SERINC5 and to assess its utility as a therapeutic strategy.

  15. Effects of BRAF mutations and BRAF inhibition on immune responses to melanoma

    Science.gov (United States)

    Ilieva, Kristina M.; Correa, Isabel; Josephs, Debra H.; Karagiannis, Panagiotis; Egbuniwe, Isioma U.; Cafferkey, Michiala J.; Spicer, James F.; Harries, Mark; Nestle, Frank O.; Lacy, Katie E.; Karagiannis, Sophia N.

    2014-01-01

    Malignant melanoma is associated with poor clinical prognosis; however, novel molecular and immune therapies are now improving patient outcomes. Almost 50% of melanomas harbor targetable activating mutations of BRAF which promote RAS-RAF-MEK-ERK pathway activation and melanoma proliferation. Recent evidence also indicates that melanomas bearing mutant BRAF may also have altered immune responses, suggesting additional avenues for treatment of this patient group. The small molecule inhibitors selective for mutant BRAF induce significant but short-lived clinical responses in a proportion of patients, but also lead to immune stimulatory bystander events, which then subside with the emergence of resistance to inhibition. Simultaneous BRAF and MEK inhibition, and especially combination of BRAF inhibitors with new immunotherapies such as checkpoint blockade antibodies, may further enhance immune activation, or counteract immunosuppressive signals. Pre-clinical evaluation and ongoing clinical trials should provide novel insights into the role of immunity in the therapy of BRAF-mutant melanoma. PMID:25385327

  16. The downregulation of Mcl-1 via USP9X inhibition sensitizes solid tumors to Bcl-xl inhibition

    International Nuclear Information System (INIS)

    Peddaboina, Chander; Smythe, W Roy; Cao, Xiaobo; Jupiter, Daniel; Fletcher, Steven; Yap, Jeremy L; Rai, Arun; Tobin, Richard P; Jiang, Weihua; Rascoe, Philip; Rogers, M Karen Newell

    2012-01-01

    It has been shown in many solid tumors that the overexpression of the pro-survival Bcl-2 family members Bcl-xL and Mcl-1 confers resistance to a variety of chemotherapeutic agents. Mcl-1 is a critical survival protein in a variety of cell lineages and is critically regulated via ubiquitination. The Mcl-1, Bcl-xL and USP9X expression patterns in human lung and colon adenocarcinomas were evaluated via immunohistochemistry. Interaction between USP9X and Mcl-1 was demonstrated by immunoprecipitation-western blotting. The protein expression profiles of Mcl-1, Bcl-xL and USP9X in multiple cancer cell lines were determined by western blotting. Annexin-V staining and cleaved PARP western blotting were used to assay for apoptosis. The cellular toxicities after various treatments were measured via the XTT assay. In our current analysis of colon and lung cancer samples, we demonstrate that Mcl-1 and Bcl-xL are overexpressed and also co-exist in many tumors and that the expression levels of both genes correlate with the clinical staging. The downregulation of Mcl-1 or Bcl-xL via RNAi was found to increase the sensitivity of the tumor cells to chemotherapy. Furthermore, our analyses revealed that USP9X expression correlates with that of Mcl-1 in human cancer tissue samples. We additionally found that the USP9X inhibitor WP1130 promotes Mcl-1 degradation and increases tumor cell sensitivity to chemotherapies. Moreover, the combination of WP1130 and ABT-737, a well-documented Bcl-xL inhibitor, demonstrated a chemotherapeutic synergy and promoted apoptosis in different tumor cells. Mcl-1, Bcl-xL and USP9X overexpression are tumor survival mechanisms protective against chemotherapy. USP9X inhibition increases tumor cell sensitivity to various chemotherapeutic agents including Bcl-2/Bcl-xL inhibitors

  17. Lasiodin inhibits proliferation of human nasopharyngeal carcinoma cells by simultaneous modulation of the Apaf-1/caspase, AKT/MAPK and COX-2/NF-κB signaling pathways.

    Directory of Open Access Journals (Sweden)

    Lianzhu Lin

    Full Text Available Rabdosia serra has been widely used for the treatment of the various human diseases. However, the antiproliferative effects and underlying mechanisms of the compounds in this herb remain largely unknown. In this study, an antiproliferative compound against human nasopharyngeal carcinoma (NPC cells from Rabdosia serra was purified and identified as lasiodin (a diterpenoid. The treatment with lasiodin inhibited cell viability and migration. Lasiodin also mediated the cell morphology change and induced apoptosis in NPC cells. The treatment with lasiodin induced the Apaf-1 expression, triggered the cytochrome-C release, and stimulated the PARP, caspase-3 and caspase-9 cleavages, thereby activating the apoptotic pathways. The treatment with lasiodin also significantly inhibited the phosphorylations of the AKT, ERK1/2, p38 and JNK proteins. The pretreatment with the AKT or MAPK-selective inhibitors considerably blocked the lasiodin-mediated inhibition of cell proliferation. Moreover, the treatment with lasiodin inhibited the COX-2 expression, abrogated NF-κB binding to the COX-2 promoter, and promoted the NF-κB translocation from cell nuclei to cytosol. The pretreatment with a COX-2-selective inhibitor abrogated the lasiodin-induced inhibition of cell proliferation. These results indicated that lasiodin simultaneously activated the Apaf-1/caspase-dependent apoptotic pathways and suppressed the AKT/MAPK and COX-2/NF-κB signaling pathways. This study also suggested that lasiodin could be a promising natural compound for the prevention and treatment of NPC.

  18. A novel small molecule inhibits STAT3 phosphorylation and DNA binding activity and exhibits potent growth suppressive activity in human cancer cells

    Directory of Open Access Journals (Sweden)

    Lin Li

    2010-08-01

    Full Text Available Abstract Background Targeting Signal Transducer and Activator of Transcription 3 (STAT3 signaling is an attractive therapeutic approach for most types of human cancers with constitutively activated STAT3. A novel small molecular STAT3 inhibitor, FLLL32 was specifically designed from dietary agent, curcumin to inhibit constitutive STAT3 signaling in multiple myeloma, glioblastoma, liver cancer, and colorectal cancer cells. Results FLLL32 was found to be a potent inhibitor of STAT3 phosphorylation, STAT3 DNA binding activity, and the expression of STAT3 downstream target genes in vitro, leading to the inhibition of cell proliferation as well as the induction of Caspase-3 and PARP cleavages in human multiple myeloma, glioblastoma, liver cancer, and colorectal cancer cell lines. However, FLLL32 exhibited little inhibition on some tyrosine kinases containing SH2 or both SH2 and SH3 domains, and other protein and lipid kinases using a kinase profile assay. FLLL32 was also more potent than four previously reported JAK2 and STAT3 inhibitors as well as curcumin to inhibit cell viability in these cancer cells. Furthermore, FLLL32 selectively inhibited the induction of STAT3 phosphorylation by Interleukin-6 but not STAT1 phosphorylation by IFN-γ. Conclusion Our findings indicate that FLLL32 exhibits potent inhibitory activity to STAT3 and has potential for targeting multiple myeloma, glioblastoma, liver cancer, and colorectal cancer cells expressing constitutive STAT3 signaling.

  19. Inhibition of Autophagy Potentiates Atorvastatin-Induced Apoptotic Cell Death in Human Bladder Cancer Cells in Vitro

    Science.gov (United States)

    Kang, Minyong; Jeong, Chang Wook; Ku, Ja Hyeon; Kwak, Cheol; Kim, Hyeon Hoe

    2014-01-01

    Statins are cholesterol reduction agents that exhibit anti-cancer activity in several human cancers. Because autophagy is a crucial survival mechanism for cancer cells under stress conditions, cooperative inhibition of autophagy acts synergistically with other anti-cancer drugs. Thus, this study investigates whether combined treatment of atorvastatin and autophagy inhibitors results in enhancing the cytotoxic effects of atorvastatin, upon human bladder cancer cells, T24 and J82, in vitro. To measure cell viability, we performed the EZ-Cytox cell viability assay. We examined apoptosis by flow cytometry using annexin-V/propidium iodide (PI and western blot using procaspase-3 and poly (ADP-ribose) polymerase (PARP) antibodies. To examine autophagy activation, we evaluated the co-localization of LC3 and LysoTracker by immunocytochemistry, as well as the expression of LC3 and p62/sequestosome-1 (SQSTM1) by western blot. In addition, we assessed the survival and proliferation of T24 and J82 cells by a clonogenic assay. We found that atorvastatin reduced the cell viability of T24 and J82 cells via apoptotic cell death and induced autophagy activation, shown by the co-localization of LC3 and LysoTracker. Moreover, pharmacologic inhibition of autophagy significantly enhanced atorvastatin-induced apoptosis in T24 and J82 cells. In sum, inhibition of autophagy potentiates atorvastatin-induced apoptotic cell death in human bladder cancer cells in vitro, providing a potential therapeutic approach to treat bladder cancer. PMID:24815071

  20. The cytotoxic effects of regorafenib in combination with protein kinase D inhibition in human colorectal cancer cells

    Science.gov (United States)

    Wei, Ning; Chu, Edward; Wu, Shao-yu; Wipf, Peter; Schmitz, John C.

    2015-01-01

    Metastatic colorectal cancer (mCRC) remains a major public health problem, and diagnosis of metastatic disease is usually associated with poor prognosis. The multi-kinase inhibitor regorafenib was approved in 2013 in the U.S. for the treatment of mCRC patients who progressed after standard therapies. However, the clinical efficacy of regorafenib is quite limited. One potential strategy to improve mCRC therapy is to combine agents that target key cellular signaling pathways, which may lead to synergistic enhancement of antitumor efficacy and overcome cellular drug resistance. Protein kinase D (PKD), a family of serine/threonine kinases, mediates key signaling pathways implicated in multiple cellular processes. Herein, we evaluated the combination of regorafenib with a PKD inhibitor in several human CRC cells. Using the Chou-Talalay model, the combination index values for this combination treatment demonstrated synergistic effects on inhibition of cell proliferation and clonal formation. This drug combination resulted in induction of apoptosis as determined by flow cytometry, increased PARP cleavage, and decreased activation of the anti-apoptotic protein HSP27. This combination also yielded enhanced inhibition of ERK, AKT, and NF-κB signaling. Taken together, PKD inhibition in combination with regorafenib appears to be a promising strategy for the treatment of mCRC. PMID:25544765

  1. PKCη confers protection against apoptosis by inhibiting the pro-apoptotic JNK activity in MCF-7 cells

    International Nuclear Information System (INIS)

    Rotem-Dai, Noa; Oberkovitz, Galia; Abu-Ghanem, Sara; Livneh, Etta

    2009-01-01

    Apoptosis is frequently regulated by different protein kinases including protein kinase C family enzymes. Both inhibitory and stimulatory effects were demonstrated for several of the different PKC isoforms. Here we show that the novel PKC isoform, PKCη, confers protection against apoptosis induced by the DNA damaging agents, UVC irradiation and the anti-cancer drug - Camptothecin, of the breast epithelial adenocarcinoma MCF-7 cells. The induced expression of PKCη in MCF-7 cells, under the control of the tetracycline-responsive promoter, resulted in increased cell survival and inhibition of cleavage of the apoptotic marker PARP-1. Activation of caspase-7 and 9 and the release of cytochrome c were also inhibited by the inducible expression of PKCη. Furthermore, JNK activity, required for apoptosis in MCF-7, as indicated by the inhibition of both caspase-7 cleavage and cytochrome c release from the mitochondria in the presence of the JNK inhibitor SP600125, was also suppressed by PKCη expression. Hence, in contrast to most PKC isoforms enhancing JNK activation, our studies show that PKCη is an anti-apoptotic protein, acting as a negative regulator of JNK activity. Thus, PKCη could represent a target for intervention aimed to reduce resistance to anti-cancer treatments.

  2. Evodiamine synergizes with doxorubicin in the treatment of chemoresistant human breast cancer without inhibiting P-glycoprotein.

    Directory of Open Access Journals (Sweden)

    Shengpeng Wang

    Full Text Available Drug resistance is one of the main hurdles for the successful treatment of breast cancer. The synchronous targeting of apoptosis resistance and survival signal transduction pathways may be a promising approach to overcome drug resistance. In this study, we determined that evodiamine (EVO, a major constituent of the Chinese herbal medicine Evodiae Fructus, could induce apoptosis of doxorubicin (DOX-sensitive MCF-7 and DOX-resistant MCF-7/ADR cells in a caspase-dependent manner, as confirmed by significant increases of cleaved poly(ADP-ribose polymerase (PARP, caspase-7/9, and caspase activities. Notably, the reversed phenomenon of apoptosis resistance by EVO might be attributed to its ability to inhibit the Ras/MEK/ERK pathway and the expression of inhibitors of apoptosis (IAPs. Furthermore, our results indicated that EVO enhanced the apoptotic action of DOX by inhibiting the Ras/MEK/ERK cascade and the expression of IAPs without inhibiting the expression and activity of P-glycoprotein (P-gp. Taken together, our data indicate that EVO, a natural product, may be useful applied alone or in combination with DOX for the treatment of resistant breast cancer.

  3. Have you tried spermine? A rapid and cost-effective method to eliminate dextran sodium sulfate inhibition of PCR and RT-PCR.

    Science.gov (United States)

    Krych, Łukasz; Kot, Witold; Bendtsen, Katja M B; Hansen, Axel K; Vogensen, Finn K; Nielsen, Dennis S

    2018-01-01

    The Dextran Sulfate Sodium (DSS) induced colitis mouse model is commonly used to investigate human inflammatory bowel disease (IBD). Nucleic acid extracts originating from these animals are often contaminated with DSS, which is a strong inhibitor of many enzymatic based molecular biology reactions including PCR and reverse-transcription (RT). Methods for removing DSS from nucleic acids extracts exist for RNA, but no effective protocol for DNA or cDNA is currently available. However, spermine has previously been shown to be an effective agent for counteracting DSS inhibition of polynucleotide kinase, which led to the hypothesis, that spermine could be used to counteract DSS inhibition of PCR and RT. We investigated the means of adding spermine in an adequate concentration to PCR based protocols (including qPCR, two-step RT-qPCR, and amplicon sequencing library preparation) to remove DSS inhibition. Within the range up to 0.01g/L, spermine can be added to PCR/qPCR or RT prophylactically without a significant reduction of reaction efficiency. Addition of spermine at the concentration of 0.08g/L can be used to recover qualitative PCR signal inhibited by DSS in concentrations up to 0.32g/L. For optimal quantitative analysis, the concentration of spermine requires fine adjustment. Hence, we present here a simple fluorometric based method for adjusting the concentration of spermine ensuring an optimal efficiency of the reaction exposed to an unknown concentration of DSS. In conclusion, we demonstrate a cost effective and easy method to counteract DSS inhibition in PCR and two-step RT-qPCR. Fixed or fine-tuned concentrations of spermine can be administered depending on the qualitative or quantitative character of the analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Caffeine counteracts impairments in task-oriented psychomotor performance induced by chlorpheniramine: a double-blind placebo-controlled crossover study.

    Science.gov (United States)

    Kim, Sung-Wan; Bae, Kyung-Yeol; Shin, Hee-Young; Kim, Jae-Min; Shin, Il-Seon; Kim, Jong-Keun; Kang, Gaeun; Yoon, Jin-Sang

    2013-01-01

    This study aimed to evaluate the effects of chlorpheniramine on psychomotor performance and the counteracting effects of caffeine on those sedative antihistamine actions. Sixteen healthy young men participated in this study. Using a double-blind placebo-controlled crossover design, each subject was administered one of the following conditions in a random order with a one-week interval: 'placebo-placebo', '4 mg of chlorpheniramine-placebo', 'placebo-200 mg of caffeine' or '4 mg of chlorpheniramine-200 mg of caffeine'. Before and after the treatments, psychomotor functions were assessed using a battery of tests. Additionally, subjective responses were assessed using a visual analogue scale (VAS). Psychomotor performance changed over time in different ways according to the combination of study medications. In the 'chlorpheniramine-placebo' condition, reaction times of the compensatory tracking task were significantly impaired compared with the other three conditions. In addition, the number of omission errors of the continuous performance test were significantly greater compared with the 'placebo-caffeine' condition. However, the response pattern of the 'chlorpheniramine-caffeine' condition was not significantly different from that of the 'placebo-placebo' condition. Changes of VAS for sleepiness were significantly greater in the 'chlorpheniramine-placebo' condition compared with the other three conditions. In conclusion, chlorpheniramine significantly increases subjective sleepiness and objectively impairs psychomotor performance. However, caffeine counteracts these sedative effects and psychomotor impairments.

  5. The lysine deacetylase inhibitor givinostat inhibits ß-cell IL-1ß induced IL-1ß transcription and processing

    DEFF Research Database (Denmark)

    Dahllöf, Mattias Salling; Christensen, Dan P; Lundh, Morten

    2012-01-01

    . Further, IL-1R antagonism improves normoglycemia and ß-cell function in type 2 diabetic patients. Inhibition of lysine deacetylases (KDACi) counteracts ß-cell toxicity induced by the combination of IL-1 and IFN¿ and reduces diabetes incidence in non-obese diabetic (NOD) mice. We hypothesized that KDACi......Aims: Pro-inflammatory cytokines and chemokines, in particular IL-1ß, IFN¿, and CXCL10, contribute to ß-cell failure and loss in DM via IL-1R, IFN¿R, and TLR4 signaling. IL-1 signaling deficiency reduces diabetes incidence, islet IL-1ß secretion, and hyperglycemia in animal models of diabetes...

  6. Evasion of antiviral innate immunity by Theiler's virus L* protein through direct inhibition of RNase L.

    Directory of Open Access Journals (Sweden)

    Frédéric Sorgeloos

    Full Text Available Theiler's virus is a neurotropic picornavirus responsible for chronic infections of the central nervous system. The establishment of a persistent infection and the subsequent demyelinating disease triggered by the virus depend on the expression of L*, a viral accessory protein encoded by an alternative open reading frame of the virus. We discovered that L* potently inhibits the interferon-inducible OAS/RNase L pathway. The antagonism of RNase L by L* was particularly prominent in macrophages where baseline oligoadenylate synthetase (OAS and RNase L expression levels are elevated, but was detectable in fibroblasts after IFN pretreatment. L* mutations significantly affected Theiler's virus replication in primary macrophages derived from wild-type but not from RNase L-deficient mice. L* counteracted the OAS/RNase L pathway through direct interaction with the ankyrin domain of RNase L, resulting in the inhibition of this enzyme. Interestingly, RNase L inhibition was species-specific as Theiler's virus L* protein blocked murine RNase L but not human RNase L or RNase L of other mammals or birds. Direct RNase L inhibition by L* and species specificity were confirmed in an in vitro assay performed with purified proteins. These results demonstrate a novel viral mechanism to elude the antiviral OAS/RNase L pathway. By targeting the effector enzyme of this antiviral pathway, L* potently inhibits RNase L, underscoring the importance of this enzyme in innate immunity against Theiler's virus.

  7. Enzyme inhibition by iminosugars

    DEFF Research Database (Denmark)

    López, Óscar; Qing, Feng-Ling; Pedersen, Christian Marcus

    2013-01-01

    Imino- and azasugar glycosidase inhibitors display pH dependant inhibition reflecting that both the inhibitor and the enzyme active site have groups that change protonation state with pH. With the enzyme having two acidic groups and the inhibitor one basic group, enzyme-inhibitor complexes...

  8. Quorum sensing inhibition

    DEFF Research Database (Denmark)

    Persson, T.; Givskov, Michael Christian; Nielsen, J.

    2005-01-01

    /receptor transcriptional regulator in some clinically relevant Gram-negative bacteria. The present review contains all reported compound types that are currently known to inhibit the QS transcriptional regulator in Gram-negative bacteria. These compounds are sub-divided into two main groups, one comprising structural...

  9. Cooperation for Better Inhibiting.

    Science.gov (United States)

    Novoa, Eva Maria; Ribas de Pouplana, Lluís

    2015-06-18

    Cladosporin is an antimalarial drug that acts as an ATP-mimetic to selectively inhibit Plasmodium lysyl-tRNA synthetase. Using multiple crystal structures, Fang et al. (2015) reveal in this issue of Chemistry & Biology the fascinating mechanism responsible for cladosporin selectivity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. The antimicrobial potential of algicolous marine fungi for counteracting multidrug-resistant bacteria: phylogenetic diversity and chemical profiling.

    Science.gov (United States)

    Gnavi, Giorgio; Palma Esposito, Fortunato; Festa, Carmen; Poli, Anna; Tedesco, Pietro; Fani, Renato; Monti, Maria Chiara; de Pascale, Donatella; D'Auria, Maria Valeria; Varese, Giovanna Cristina

    2016-01-01

    Marine fungi represent an important but still largely unexplored source of novel and potentially bioactive secondary metabolites. The antimicrobial activity of nine sterile mycelia isolated from the green alga Flabellia petiolata collected from the Mediterranean Sea was tested on four antibiotic-resistant bacterial strains using extracellular and intracellular extracts obtained from each fungal strain. The isolated fungi were identified at the molecular level and assigned to one of the Dothideomycetes, Sordariomycetes or Eurotiomycetes classes. Following assessment of inhibition of bacterial growth (IC50), all crude extracts were subjected to preliminary (1)H NMR and TLC analysis. According to preliminary pharmacologic and spectroscopic/chromatographic results, extracts of fungal strains MUT 4865, classified as Beauveria bassiana, and MUT 4861, classified as Microascacea sp.2, were selected for LC-HRMS analysis. Chemical profiling of antibacterial extracts from MUT 4861 and MUT 4865 by LC HRMS allowed identification of the main components of the crude extracts. Several sphingosine bases were identified, including a compound previously unreported from natural sources, which gave a rationale to the broad spectrum of antibacterial activity exhibited. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  11. PGC-1/Spargel Counteracts High-Fat-Diet-Induced Obesity and Cardiac Lipotoxicity Downstream of TOR and Brummer ATGL Lipase

    Directory of Open Access Journals (Sweden)

    Soda Balla Diop

    2015-03-01

    Full Text Available Obesity and metabolic syndrome are associated with an increased risk for lipotoxic cardiomyopathy, which is strongly correlated with excessive accumulation of lipids in the heart. Obesity- and type-2-diabetes-related disorders have been linked to altered expression of the transcriptional cofactor PGC-1α, which regulates the expression of genes involved in energy metabolism. Using Drosophila, we identify PGC-1/spargel (PGC-1/srl as a key antagonist of high-fat diet (HFD-induced lipotoxic cardiomyopathy. We find that HFD-induced lipid accumulation and cardiac dysfunction are mimicked by reduced PGC-1/srl function and reversed by PGC-1/srl overexpression. Moreover, HFD feeding lowers PGC-1/srl expression by elevating TOR signaling and inhibiting expression of the Drosophila adipocyte triglyceride lipase (ATGL (Brummer, both of which function as upstream modulators of PGC-1/srl. The lipogenic transcription factor SREBP also contributes to HFD-induced cardiac lipotoxicity, likely in parallel with PGC-1/srl. These results suggest a regulatory network of key metabolic genes that modulates lipotoxic heart dysfunction.

  12. Estrogenic compounds inhibit gap junctional intercellular communication in mouse Leydig TM3 cells

    International Nuclear Information System (INIS)

    Iwase, Yumiko; Fukata, Hideki; Mori, Chisato

    2006-01-01

    Some estrogenic compounds are reported to cause testicular disorders in humans and/or experimental animals by direct action on Leydig cells. In carcinogenesis and normal development, gap junctional intercellular communication (GJIC) plays an essential role in maintaining homeostasis. In this study, we examine the effects of diethylstilbestrol (DES, a synthetic estrogen), 17β-estradiol (E 2 , a natural estrogen), and genistein (GEN, a phytoestrogen) on GJIC between mouse Leydig TM3 cells using Lucifer yellow microinjection. The three compounds tested produced GJIC inhibition in the TM3 cells after 24 h. Gradually, 10 μM DES began to inhibit GJIC for 24 h and this effect was observed until 72 h. On the other hand, both 20 μM E 2 and 25 μM GEN rapidly inhibited GJIC in 6 h and 2 h, respectively. The effects continued until 24 h, but weakened by 72 h. Furthermore, a combined effect at μM level between DES and E 2 on GJIC inhibition was observed, but not between GEN and E 2 . DES and E 2 showed GJIC inhibition at low dose levels (nearly physiological estrogen levels) after 72 h, but GEN did not. DE