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Sample records for adp-ribose polymerase parp

  1. Signaling Mechanism of Poly(ADP-Ribose) Polymerase-1 (PARP-1) in Inflammatory Diseases

    OpenAIRE

    Ba, Xueqing; Garg, Nisha Jain

    2011-01-01

    Poly(ADP-ribosyl)ation, attaching the ADP-ribose polymer chain to the receptor protein, is a unique posttranslational modification. Poly(ADP-ribose) polymerase-1 (PARP-1) is a well-characterized member of the PARP family. In this review, we provide a general update on molecular structure and structure-based activity of this enzyme. However, we mainly focus on the roles of PARP-1 in inflammatory diseases. Specifically, we discuss the signaling pathway context that PARP-1 is involved in to regu...

  2. Poly(ADP-ribose) polymerase (PARP-1) has a controlling role in homologous recombination

    OpenAIRE

    Schultz, Niklas; Lopez, Elena; Saleh-Gohari, Nasrollah; Helleday, Thomas

    2003-01-01

    Cells with non-functional poly(ADP-ribose) polymerase (PARP-1) show increased levels of sister chromatid exchange, suggesting a hyper recombination phenotype in these cells. To further investigate the involvement of PARP-1 in homologous recombination (HR) we investigated how PARP-1 affects nuclear HR sites (Rad51 foci) and HR repair of an endonuclease-induced DNA double-strand break (DSB). Several proteins involved in HR localise to Rad51 foci and HR-deficient cells fail to form Rad51 foci in...

  3.  Poly(ADP-ribose polymerase (PARP inhibitors in BRCA1/2 cancer therapy

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    Katarzyna Kluzek

    2012-06-01

    Full Text Available  A majority of currently used anticancer drugs belong to a group of chemical agents that damage DNA. The efficiency of the treatment is limited by effective DNA repair systems functioning in cancer cells. Many chemotherapeutic compounds cause strong systemic toxicity. Therefore, there is still a need for new anticancer agents which are less toxic for nontransformed cells and selectively kill cancer cells. One of the most promising molecular targets in cancer therapy is poly(ADP-ribose polymerases (PARP. PARP play an essential role in repairing DNA strand breaks. Small molecule inhibitors of these enzymes have been developed and have proved to be extremely toxic for cancer cells that lack the functional BRCA1 and BRCA2 proteins that are involved in homologous recombination, a complex repair mechanism of DNA double strand breaks. Mutations in BRCA1/2 genes are associated with genetically inherited breast and ovarian cancers. Therefore PARP inhibitors may prove to be very effective and selective in the treatment of these cancer types. This review is focused on the function of BRCA1/2 proteins and poly(ADP-ribose polymerases in DNA repair systems, especially in the homologous recombination process. A short history of the studies that led to synthesis of high specificity small molecule PARP inhibitors is also presented, as well as the results of clinical trials concerning the most effective PARP inhibitors in view of their potential application in oncological treatment, particularly breast cancers.

  4. Regulation of poly(ADP-ribose) polymerase-1 (PARP-1) gene expression through the post-translational modification of Sp1: a nuclear target protein of PARP-1

    OpenAIRE

    Guérin Sylvain L; Leclerc Steeve; Desnoyers Serge; Zaniolo Karine

    2007-01-01

    Abstract Background Poly(ADP-ribose) polymerase-1 (PARP-1) is a nuclear enzyme that plays critical functions in many biological processes, including DNA repair and gene transcription. The main function of PARP-1 is to catalyze the transfer of ADP-ribose units from nicotinamide adenine dinucleotide (NAD+) to a large array of acceptor proteins, which comprises histones, transcription factors, as well as PARP-1 itself. We have previously demonstrated that transcription of the PARP-1 gene essenti...

  5. Poly(ADP-Ribose) Polymerase in Cervical Cancer Pathogenesis: Mechanism and Potential Role for PARP Inhibitors.

    Science.gov (United States)

    Kotsopoulos, Ioannis C; Kucukmetin, Ali; Mukhopadhyay, Asima; Lunec, John; Curtin, Nicola J

    2016-05-01

    Treatment options for disease recurrence of women treated for locally advanced and advanced cervical cancer are very limited-largely palliative chemotherapy. The low efficacy of the currently available drugs raises the need for new targeted agents. Poly(adenosine diphosphate [ADP]-ribose) polymerase (PARP) inhibitors (PARPi) have emerged as a promising class of chemotherapeutic agents in cancers associated with defects in DNA repair. Their therapeutic potential in cervical cancer is currently being evaluated in 3 ongoing clinical trials. Here we review the available information regarding all the aspects of PARP in cervical intraepithelial neoplasia and invasive cervical cancer, from expression and the mechanism of action to the role of the polymorphisms in the pathogenesis of the disease, as well as the potential of the inhibitors. We finally propose a new unifying theory regarding the role of PARPs in the development of cervical carcinomas. PMID:26905326

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

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    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.

  7. PARP1 Is a TRF2-associated Poly(ADP-Ribose)Polymerase and Protects Eroded Telomeres

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yie [ORNL; Wu, Jun [ORNL; Schreiber, Valerie [Universite Louis Pasteur, France; Dunlap, John [University of Tennessee, Knoxville (UTK); Dantzer, Francoise [Universite Louis Pasteur, France; Wang, Yisong [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL)

    2006-01-01

    Poly(ADP-ribose)polymerase 1 (PARP1) is well characterized for its role in base excision repair (BER), where it is activated by and binds to DNA breaks and catalyzes the poly(ADP-ribosyl)ation of several substrates involved in DNA damage repair. Here we demonstrate that PARP1 associates with telomere repeat binding factor 2 (TRF2) and is capable of poly(ADP-ribosyl)ation of TRF2, which affects binding of TRF2 to telomeric DNA. Immunostaining of interphase cells or metaphase spreads shows that PARP1 is detected sporadically at normal telomeres, but it appears preferentially at eroded telomeres caused by telomerase deficiency or damaged telomeres induced by DNA-damaging reagents. Although PARP1 is dispensable in the capping of normal telomeres, Parp1 deficiency leads to an increase in chromosome end-to-end fusions or chromosome ends without detectable telomeric DNA in primary murine cells after induction of DNA damage. Our results suggest that upon DNA damage, PARP1 is recruited to damaged telomeres, where it can help protect telomeres against chromosome end-to-end fusions and genomic instability.

  8. PARP1 is a TRF2-associated poly(ADP-ribose) polymerase and protects eroded telomeres

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Marla V [ORNL; Wu, Jun [ORNL; Wang, Yisong [ORNL; Liu, Yie [ORNL

    2006-01-01

    Poly(ADP-ribose)polymerase 1 (PARP1) is well characterized for its role in base excision repair (BER), where it is activated by and binds to DNA breaks and catalyzes the poly(ADP-ribosyl)ation of several substrates involved in DNA damage repair. Here we demonstrate that PARP1 associates with telomere repeat binding factor 2 (TRF2) and is capable of poly(ADP-ribosyl)ation of TRF2, which affects binding of TRF2 to telomeric DNA. Immunostaining of interphase cells or metaphase spreads shows that PARP1 is detected sporadically at normal telomeres, but it appears preferentially at eroded telomeres caused by telomerase deficiency or damaged telomeres induced by DNA-damaging reagents. Although PARP1 is dispensable in the capping of normal telomeres, Parp1 deficiency leads to an increase in chromosome end-to-end fusions or chromosome ends without detectable telomeric DNA in primary murine cells after induction of DNA damage. Our results suggest that upon DNA damage, PARP1 is recruited to damaged telomeres, where it can help protect telomeres against chromosome end-to-end fusions and genomic instability.

  9. Gemcitabine induces poly (ADP-ribose polymerase-1 (PARP-1 degradation through autophagy in pancreatic cancer.

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    Yufeng Wang

    Full Text Available Poly (ADP-ribose polymerase-1 (PARP-1 and autophagy play increasingly important roles in DNA damage repair and cell death. Gemcitabine (GEM remains the first-line chemotherapeutic drug for pancreatic cancer (PC. However, little is known about the relationship between PARP-1 expression and autophagy in response to GEM. Here we demonstrate that GEM induces DNA-damage response and degradation of mono-ADP ribosylated PARP-1 through the autophagy pathway in PC cells, which is rescued by inhibiting autophagy. Hypoxia and serum starvation inhibit autophagic activity due to abrogated GEM-induced mono-ADP-ribosylated PARP-1 degradation. Activation of extracellular regulated protein kinases (ERK induced by serum starvation shows differences in intracellular localization as well as modulation of autophagy and PARP-1 degradation in GEM-sensitive KLM1 and -resistant KLM1-R cells. Our study has revealed a novel role of autophagy in PARP-1 degradation in response to GEM, and the different impacts of MEK/ERK signaling pathway on autophagy between GEM-sensitive and -resistant PC cells.

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

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    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.

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

    OpenAIRE

    Fernet Marie; Giocanti Nicole; Noël Georges; Mégnin-Chanet Frédérique; Favaudon Vincent

    2003-01-01

    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...

  12. PIASy Mediates SUMO-2/3 Conjugation of Poly(ADP-ribose) Polymerase 1 (PARP1) on Mitotic Chromosomes*

    OpenAIRE

    Ryu, Hyunju; Al-Ani, Gada; Deckert, Katelyn; Kirkpatrick, Donald; Gygi, Steven P.; Dasso, Mary; Azuma, Yoshiaki

    2010-01-01

    PIASy is a small ubiquitin-related modifier (SUMO) ligase that modifies chromosomal proteins in mitotic Xenopus egg extracts and plays an essential role in mitotic chromosome segregation. We have isolated a novel SUMO-2/3-modified mitotic chromosomal protein and identified it as poly(ADP-ribose) polymerase 1 (PARP1). PARP1 was robustly conjugated to SUMO-2/3 on mitotic chromosomes but not on interphase chromatin. PIASy promotes SUMOylation of PARP1 both in egg extracts and in vitro reconstitu...

  13. Poly(ADP-ribose) Polymerase-1 (PARP-1) Inhibition Improves Coronary Arteriole Function in Type 2 Diabetes

    OpenAIRE

    Choi, Soo-Kyoung; Galán, Maria; Kassan, Modar; Partyka, Megan; Trebak, Mohamed; Matrougui, Khalid

    2012-01-01

    Type 2 diabetes (T2D) is associated with microvascular dysfunction. We hypothesized that increased Poly - (ADP-ribose) polymerase-1 (PARP-1) activity contributes to microvascular dysfunction in T2D. T2D (db-/db-) and non-diabetic control (db-/db+) mice were treated with two different PARP-1 inhibitors (INO-1001, 5 mg/Kg/day and ABT-888, 15 mg/Kg/day) for two weeks. Isolated coronary arterioles (CA) were mounted in an arteriograph. Pressure-induced myogenic tone (MT) was significantly potentia...

  14. Transcriptional Reprogramming and Resistance to Colonic Mucosal Injury in Poly(ADP-ribose) Polymerase 1 (PARP1)-deficient Mice.

    Science.gov (United States)

    Larmonier, Claire B; Shehab, Kareem W; Laubitz, Daniel; Jamwal, Deepa R; Ghishan, Fayez K; Kiela, Pawel R

    2016-04-22

    Poly(ADP-ribose) polymerases (PARPs) synthesize and bind branched polymers of ADP-ribose to acceptor proteins using NAD as a substrate and participate in the control of gene transcription and DNA repair. PARP1, the most abundant isoform, regulates the expression of proinflammatory mediator cytokines, chemokines, and adhesion molecules, and inhibition of PARP1 enzymatic activity reduced or ameliorated autoimmune diseases in several experimental models, including colitis. However, the mechanism(s) underlying the protective effects of PARP1 inhibition in colitis and the cell types in which Parp1 deletion has the most significant impact are unknown. The objective of the current study was to determine the impact of Parp1 deletion on the innate immune response to mucosal injury and on the gut microbiome composition. Parp1 deficiency was evaluated in DSS-induced colitis in WT, Parp1(-/-), Rag2(-/-), and Rag2(-/-)×Parp1(-/-) double knock-out mice. Genome-wide analysis of the colonic transcriptome and fecal 16S amplicon profiling was performed. Compared with WT, we demonstrated that Parp1(-/-) were protected from dextran-sulfate sodium-induced colitis and that this protection was associated with a dramatic transcriptional reprogramming in the colon. PARP1 deficiency was also associated with a modulation of the colonic microbiota (increases relative abundance of Clostridia clusters IV and XIVa) and a concomitant increase in the frequency of mucosal CD4(+)CD25(+) Foxp3(+) regulatory T cells. The protective effects conferred by Parp1 deletion were lost in Rag2(-/-) × Parp1(-/-) mice, highlighting the role of the adaptive immune system for full protection. PMID:26912654

  15. PARP-1 mechanism for coupling DNA damage detection to poly(ADP-ribose) synthesis

    OpenAIRE

    Langelier, Marie-France; Pascal, John M.

    2013-01-01

    Poly(ADP-ribose) polymerase 1 (PARP-1) regulates gene transcription, cell death signaling, and DNA repair through production of the posttranslational modification poly(ADP-ribose). During the cellular response to genotoxic stress PARP-1 rapidly associates with DNA damage, which robustly stimulates poly(ADP-ribose) production over a low basal level of PARP-1 activity. DNA damage-dependent PARP-1 activity is central to understanding PARP-1 biological function, but structural insights into the m...

  16. Modulation of Poly(ADP-Ribose) Polymerase-1 (PARP-1)-Mediated Oxidative Cell Injury by Ring Finger Protein 146 (RNF146) in Cardiac Myocytes

    OpenAIRE

    Gerö, Domokos; Szoleczky, Petra; Chatzianastasiou, Athanasia; Papapetropoulos, Andreas; Szabo, Csaba

    2014-01-01

    Poly(ADP-ribose) polymerase-1 (PARP-1) activation is a hallmark of oxidative stress–induced cellular injury that can lead to energetic failure and necrotic cell death via depleting the cellular nicotinamide adenine dinucleotide (NAD+) and ATP pools. Pharmacological PARP-1 inhibition or genetic PARP-1 deficiency exert protective effects in multiple models of cardiomyocyte injury. However, the connection between nuclear PARP-1 activation and depletion of the cytoplasmic and mitochondrial energy...

  17. Apurinic/apyrimidinic (AP) site recognition by the 5′-dRP/AP lyase in poly(ADP-ribose) polymerase-1 (PARP-1)

    OpenAIRE

    Khodyreva, S. N.; Prasad, R; Ilina, E. S.; Sukhanova, M. V.; Kutuzov, M. M.; Liu, Y.; Hou, E. W.; Wilson, S H; Lavrik, O. I.

    2010-01-01

    The capacity of human poly(ADP-ribose) polymerase-1 (PARP-1) to interact with intact apurinic/apyrimidinic (AP) sites in DNA has been demonstrated. In cell extracts, sodium borohydride reduction of the PARP-1/AP site DNA complex resulted in covalent cross-linking of PARP-1 to DNA; the identity of cross-linked PARP-1 was confirmed by mass spectrometry. Using purified human PARP-1, the specificity of PARP-1 binding to AP site-containing DNA was confirmed in competition binding experiments. PARP...

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

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    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.

  19. On PAR with PARP: cellular stress signaling through poly(ADP-ribose) and PARP-1

    OpenAIRE

    Luo, Xin; Kraus, W. Lee

    2012-01-01

    PARP-1 (poly[ADP-ribose] polymerase-1) is a nuclear enzyme that processes varied stress signals and, in response, determines cell fates based on the type and strength of the stress stimulus. PAR (poly[ADP-ribose]) is generated by PARP-1 and regulates many of these stress response pathways. In this review, Kraus and colleagues discuss recent important findings that elucidate the role of PAR and PARP-1 in the regulation of stress response.

  20. Identification of Poly (ADP-ribose) Polymerase-1 (PARP-1) as a Novel Krüppel-like Factor 8-interacting and -regulating Protein*

    OpenAIRE

    Lu, Heng; Wang, Xianhui; Li, Tianshu; Urvalek, Alison M.; Yu, Lin; Li, Jieli; Zhu, Jinghua; Lin, Qishan; Peng, Xu; Zhao, Jihe

    2011-01-01

    Krüppel-like factor 8 (KLF8) regulates critical gene transcription and cellular events associated with cancer. However, KLF8-interacting proteins remain largely unidentified. Using co-immunoprecipitation (co-IP), mass spectrometry, and GST pulldown assays, we identified poly(ADP-ribose) polymerase-1 (PARP-1) as a novel KLF8-interacting protein. Co-IP and Western blotting indicated that KLF8 is also a PARP-1 substrate. Mutation of the cysteines in the zinc finger domain of KLF8 abolished PARP-...

  1. Regulation of Myofibroblast Differentiation by Poly(ADP-Ribose) Polymerase 1

    OpenAIRE

    Hu, Biao; Wu, Zhe; Hergert, Polla; Henke, Craig A.; Bitterman, Peter B.; Phan, Sem H.

    2013-01-01

    Poly(ADP-ribosyl)ation (PARylation) is a post-translational protein modification effected by enzymes belonging to the poly(ADP-ribose) polymerase (PARP) superfamily, mainly by PARP-1. The key acceptors of poly(ADP-ribose) include PARP-1 itself, histones, DNA repair proteins, and transcription factors. Because many of these factors are involved in the regulation of myofibroblast differentiation, we examined the role of PARylation on myofibroblast differentiation. Overexpression of PARP-1 with ...

  2. Two-color fluorescence detection of Poly (ADP-Ribose Polymerase-1 (PARP-1 cleavage and DNA strand breaks in etoposide-induced apoptotic cells

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    C Soldani

    2009-12-01

    Full Text Available During apoptosis, the nuclear enzyme Poly(ADPRibose Polymerase-1 (PARP-1 catalyzes the rapid and transient synthesis of poly(ADP-ribose from NAD+ and becomes inactive when cleaved by caspases. The regulation of these two opposite roles of PARP-1 is still unknown. We have recently investigated PARP-1 activation/degradation in Hep-2 cells driven to apoptosis by actinomycin D. In the present work, we have extended our analysis to the effect of the DNA damaging agent etoposide, and paid attention to the relationship between PARP-1 cleavage and DNA fragmentation. An original fluorescent procedure was developed to simultaneously identify in situ the p89 proteolytic fragment of PARP-1 (by immunolabeling and DNA degradation (by the TUNEL assay. The presence of p89 was observed both in cells with advanced signs of apoptosis (where the PARP-1 fragment is extruded from the nucleus into the cytoplasm and in TUNEL-negative cells, with only incipient signs of chromatin condensation; this evidence indicates that PARP-1 degradation in etoposide-treated apoptotic cells may precede DNA cleavage.

  3. 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)

    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)

  4. 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)

    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 C4 (LTC4) 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. LTC4 (1 nM) significantly elevated the mRNA levels of PARP-1 by 2.38-fold in VICs. Taken together, these data suggest that valvular

  5. The level of Ets-1 protein is regulated by poly(ADP-ribose polymerase-1 (PARP-1 in cancer cells to prevent DNA damage.

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    Arnaud J Legrand

    Full Text Available Ets-1 is a transcription factor that regulates many genes involved in cancer progression and in tumour invasion. It is a poor prognostic marker for breast, lung, colorectal and ovary carcinomas. Here, we identified poly(ADP-ribose polymerase-1 (PARP-1 as a novel interaction partner of Ets-1. We show that Ets-1 activates, by direct interaction, the catalytic activity of PARP-1 and is then poly(ADP-ribosylated in a DNA-independent manner. The catalytic inhibition of PARP-1 enhanced Ets-1 transcriptional activity and caused its massive accumulation in cell nuclei. Ets-1 expression was correlated with an increase in DNA damage when PARP-1 was inhibited, leading to cancer cell death. Moreover, PARP-1 inhibitors caused only Ets-1-expressing cells to accumulate DNA damage. These results provide new insight into Ets-1 regulation in cancer cells and its link with DNA repair proteins. Furthermore, our findings suggest that PARP-1 inhibitors would be useful in a new therapeutic strategy that specifically targets Ets-1-expressing tumours.

  6. Inhibition of Nuclear Receptor Signalling by Poly(ADP-Ribose) Polymerase

    OpenAIRE

    Miyamoto, Takahide; Kakizawa, Tomoko; Hashizume, Kiyoshi

    1999-01-01

    Mammalian poly(ADP-ribose) polymerase (PARP) is a nuclear chromatin-associated protein with a molecular mass of 114 kDa that catalyzes the transfer of ADP-ribose units from NAD+ to nuclear proteins that are located within chromatin. We report here the identification of a novel property of PARP as a modulator of nuclear receptor signalling. PARP bound directly to retinoid X receptors (RXR) and repressed ligand-dependent transcriptional activities mediated by heterodimers of RXR and thyroid hor...

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

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    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.

  8. Poly (ADP-Ribose) Polymerase 1 Is Required for Protein Localization to Cajal Body

    OpenAIRE

    Kotova, Elena; Jarnik, Michael; Tulin, Alexei V.

    2009-01-01

    Recently, the nuclear protein known as Poly (ADP-ribose) Polymerase1 (PARP1) was shown to play a key role in regulating transcription of a number of genes and controlling the nuclear sub-organelle nucleolus. PARP1 enzyme is known to catalyze the transfer of ADP-ribose to a variety of nuclear proteins. At present, however, while we do know that the main acceptor for pADPr in vivo is PARP1 protein itself, by PARP1 automodification, the significance of PARP1 automodification for in vivo processe...

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

    Directory of Open Access Journals (Sweden)

    Vladimir N. Anisimov

    2008-04-01

    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.; P< .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.

  10. Treatment with insulin inhibits poly(ADP-ribose)polymerase activation in a rat model of endotoxemia

    OpenAIRE

    Horváth, Eszter M; Benk, Rita; Ger, Domonkos; Kiss, Levente; Szabó, Csaba

    2007-01-01

    In critically ill patients various conditions may lead to the activation of poly(ADP-ribose) polymerase (PARP). By promoting cellular energetic dysfunction, and by enhancing pro-inflammatory gene expression, PARP activation significantly contributes to the pathogenesis of shock. PARP activation is usually triggered by DNA strand breakage, which is typically the result of the overproduction of various reactive oxidant species. One of the pathophysiological conditions associated with PARP activ...

  11. Poly(ADP-Ribose) Polymerase 1: Cellular Pluripotency, Reprogramming, and Tumorogenesis

    OpenAIRE

    Bo-Hua Jiang; Wei-Lien Tseng; Hsin-Yang Li; Mong-Lien Wang; Yuh-Lih Chang; Yen-Jen Sung; Shih-Hwa Chiou

    2015-01-01

    Poly(ADP-ribos)ylation (PARylation) is the catalytic function of the Poly(ADP-ribose) polymerases (Parps) family for post-translational modification in cellular process. Being a major member of Parps, Parp1 is a crucial nuclear factor with biological significance in modulating DNA repair, DNA replication, transcription, DNA methylation and chromatin remodeling through PARylation of downstream proteins. In addition, high expression level and activity of Parp1 are correlated with pluripotent st...

  12. Poly(ADP-Ribose) Polymerase 1 Promotes Transcriptional Repression of Integrated Retroviruses

    OpenAIRE

    Bueno, Murilo T. D.; Reyes, Daniel; Valdes, Luis; Saheba, Adarsh; Urias, Eduardo; Mendoza, Crystal; Fregoso, Oliver I.; de Llano, Manuel

    2013-01-01

    Poly(ADP-ribose) polymerase 1 (PARP-1) is a cellular enzyme with a fundamental role in DNA repair and the regulation of chromatin structure, processes involved in the cellular response to retroviral DNA integration. However, the function of PARP-1 in retroviral DNA integration is controversial, probably due to the functional redundancy of the PARP family in mammalian cells. We evaluated the function of PARP-1 in retroviral infection using the chicken B lymphoblastoid cell line DT40. These cel...

  13. Differential and Concordant Roles for Poly(ADP-Ribose) Polymerase 1 and Poly(ADP-Ribose) in Regulating WRN and RECQL5 Activities

    OpenAIRE

    Khadka, Prabhat; Hsu, Joseph K; Veith, Sebastian; Tadokoro, Takashi; Shamanna, Raghavendra A.; Mangerich, Aswin; Croteau, Deborah L.; Bohr, Vilhelm A.

    2015-01-01

    Poly(ADP-ribose) (PAR) polymerase 1 (PARP1) catalyzes the poly(ADP-ribosyl)ation (PARylation) of proteins, a posttranslational modification which forms the nucleic acid-like polymer PAR. PARP1 and PAR are integral players in the early DNA damage response, since PARylation orchestrates the recruitment of repair proteins to sites of damage. Human RecQ helicases are DNA unwinding proteins that are critical responders to DNA damage, but how their recruitment and activities are regulated by PARPs ...

  14. Minocycline inhibits poly(ADP-ribose) polymerase-1 at nanomolar concentrations

    OpenAIRE

    Alano, Conrad C.; Kauppinen, Tiina M; Valls, Andreu Viader; Swanson, Raymond A.

    2006-01-01

    Poly(ADP-ribose) polymerase-1 (PARP-1), when activated by DNA damage, promotes both cell death and inflammation. Here we report that PARP-1 enzymatic activity is directly inhibited by minocycline and other tetracycline derivatives that have previously been shown to have neuroprotective and anti-inflammatory actions. These agents were evaluated by using cortical neuron cultures in which PARP-1 activation was induced by the genotoxic agents N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) or 3-morph...

  15. A novel crosstalk between BRCA1 and poly (ADP-ribose) polymerase 1 in breast cancer

    OpenAIRE

    Li, Da; Bi, Fang-Fang; Chen, Na-Na; Cao, Ji-Min; Sun, Wu-Ping; Zhou, Yi-Ming; Li, Chun-Yan; Yang, Qing

    2014-01-01

    BRCA mutations are the main known hereditary factor for breast cancer. Notably, poly (ADP-ribose) polymerase 1 (PARP1) expression status plays a critical role in breast cancer progression and the clinical development of PARP1 inhibitors to treat BRCA-mutated breast cancer has advanced rapidly. However, dynamic crosstalk between BRCA1 and PARP1 remains largely unknown. Here, we showed that: (i) BRCA1 inactivation events (mutation, promoter methylation, or knockdown) were accompanied by increas...

  16. Biology of Poly(ADP-Ribose) Polymerases: The Factotums of Cell Maintenance.

    Science.gov (United States)

    Bai, Peter

    2015-06-18

    The protein family of poly(ADP-ribose) polymerases (PARPs) or diphtheria toxin-type ADP-ribose transferases (ARTDs) are multidomain proteins originally identified as DNA repair factors. There are 17 PARP enzymes in humans, and it is now evident that PARPs undertake more tasks than DNA repair. The aim of this review is to give a comprehensive view of the biological roles of the PARP family starting from the simplest biochemical reactions to complex regulatory circuits. Special attention will be laid on discussing linkage of PARP enzymes with tumor biology, oxidative stress, inflammatory, and metabolic diseases. A better understanding of PARP-mediated processes and pathologies may help in identifying new pathways and, by these, new targets to combat diseases that affect large populations and seriously shorten life expectancy and the quality of life, such as cancer, metabolic, or inflammatory diseases. PMID:26091343

  17. Poly (ADP-ribose polymerase 1 is required for protein localization to Cajal body.

    Directory of Open Access Journals (Sweden)

    Elena Kotova

    2009-02-01

    Full Text Available Recently, the nuclear protein known as Poly (ADP-ribose Polymerase1 (PARP1 was shown to play a key role in regulating transcription of a number of genes and controlling the nuclear sub-organelle nucleolus. PARP1 enzyme is known to catalyze the transfer of ADP-ribose to a variety of nuclear proteins. At present, however, while we do know that the main acceptor for pADPr in vivo is PARP1 protein itself, by PARP1 automodification, the significance of PARP1 automodification for in vivo processes is not clear. Therefore, we investigated the roles of PARP1 auto ADP-ribosylation in dynamic nuclear processes during development. Specifically, we discovered that PARP1 automodification is required for shuttling key proteins into Cajal body (CB by protein non-covalent interaction with pADPr in vivo. We hypothesize that PARP1 protein shuttling follows a chain of events whereby, first, most unmodified PARP1 protein molecules bind to chromatin and accumulate in nucleoli, but then, second, upon automodification with poly(ADP-ribose, PARP1 interacts non-covalently with a number of nuclear proteins such that the resulting protein-pADPr complex dissociates from chromatin into CB.

  18. Tripartite Motif-containing 33 (TRIM33) protein functions in the poly(ADP-ribose) polymerase (PARP)-dependent DNA damage response through interaction with Amplified in Liver Cancer 1 (ALC1) protein.

    Science.gov (United States)

    Kulkarni, Atul; Oza, Jay; Yao, Ming; Sohail, Honeah; Ginjala, Vasudeva; Tomas-Loba, Antonia; Horejsi, Zuzana; Tan, Antoinette R; Boulton, Simon J; Ganesan, Shridar

    2013-11-01

    Activation of poly(ADP-ribose) polymerase (PARP) near sites of DNA breaks facilitates recruitment of DNA repair proteins and promotes chromatin relaxation in part through the action of chromatin-remodeling enzyme Amplified in Liver Cancer 1 (ALC1). Through proteomic analysis we find that ALC1 interacts after DNA damage with Tripartite Motif-containing 33 (TRIM33), a multifunctional protein implicated in transcriptional regulation, TGF-β signaling, and tumorigenesis. We demonstrate that TRIM33 is dynamically recruited to DNA damage sites in a PARP1- and ALC1-dependent manner. TRIM33-deficient cells show enhanced sensitivity to DNA damage and prolonged retention of ALC1 at sites of DNA breaks. Conversely, overexpression of TRIM33 alleviates the DNA repair defects conferred by ALC1 overexpression. Thus, TRIM33 plays a role in PARP-dependent DNA damage response and regulates ALC1 activity by promoting its timely removal from sites of DNA damage. PMID:23926104

  19. Tripartite Motif-containing 33 (TRIM33) Protein Functions in the Poly(ADP-ribose) Polymerase (PARP)-dependent DNA Damage Response through Interaction with Amplified in Liver Cancer 1 (ALC1) Protein*

    Science.gov (United States)

    Kulkarni, Atul; Oza, Jay; Yao, Ming; Sohail, Honeah; Ginjala, Vasudeva; Tomas-Loba, Antonia; Horejsi, Zuzana; Tan, Antoinette R.; Boulton, Simon J.; Ganesan, Shridar

    2013-01-01

    Activation of poly(ADP-ribose) polymerase (PARP) near sites of DNA breaks facilitates recruitment of DNA repair proteins and promotes chromatin relaxation in part through the action of chromatin-remodeling enzyme Amplified in Liver Cancer 1 (ALC1). Through proteomic analysis we find that ALC1 interacts after DNA damage with Tripartite Motif-containing 33 (TRIM33), a multifunctional protein implicated in transcriptional regulation, TGF-β signaling, and tumorigenesis. We demonstrate that TRIM33 is dynamically recruited to DNA damage sites in a PARP1- and ALC1-dependent manner. TRIM33-deficient cells show enhanced sensitivity to DNA damage and prolonged retention of ALC1 at sites of DNA breaks. Conversely, overexpression of TRIM33 alleviates the DNA repair defects conferred by ALC1 overexpression. Thus, TRIM33 plays a role in PARP-dependent DNA damage response and regulates ALC1 activity by promoting its timely removal from sites of DNA damage. PMID:23926104

  20. PolyADP-ribose polymerase is a coactivator for AP-2-mediated transcriptional activation.

    OpenAIRE

    Kannan, P; Yu, Y; Wankhade, S; Tainsky, M A

    1999-01-01

    Overexpression of transcription factor AP-2 has been implicated in the tumorigenicity of the human teratocarcinoma cell lines PA-1 that contain an activated ras oncogene. Here we show evidence that overexpression of AP-2 sequesters transcriptional coactivators which results in self-inhibition. We identified AP-2-interacting proteins and determined whether these proteins were coactivators for AP-2-mediated transcription. One such interacting protein is polyADP-ribose polymerase (PARP). PARP su...

  1. Inhibition of poly(ADP-ribose) polymerase 1 protects against acute myeloid leukemia by suppressing the myeloproliferative leukemia virus oncogene

    OpenAIRE

    Wang, Lingbo; Cai, Weili; Zhang, Wei; Chen, Xueying; Dong, Wenqian; Tang, Dongqi; Zhang, Yun; Ji, Chunyan; Zhang, Mingxiang

    2015-01-01

    An abnormal expression of poly(ADP-ribose) polymerase 1 (PARP-1) has been described in many tumors. PARP-1 promotes tumorigenesis and cancer progression by acting on different molecular pathways. PARP-1 inhibitors can be used with radiotherapy or chemotherapy to enhance the susceptibility of tumor cells to the treatment. However, the specific mechanism of PARP-1 in acute myeloid leukemia (AML) remains unknown. Our study showed that expression of PARP-1 was upregulated in AML patients. PARP-1 ...

  2. Polymorphisms in poly (ADP-ribose) polymerase-1 (PARP1) promoter and 3’ untranslated region and their association with PARP1 expression in breast cancer patients

    OpenAIRE

    Zhai, Lili; LI, SHUAI; Li, Huilan; Zheng, Yi; Lang, Ronggang; Fan, Yu; Gu, Feng; Guo, Xiaojing; Zhang, Xinmin; Fu, Li

    2015-01-01

    Within the past several years, inhibition of the PARP1 activity has been emerged as one of the most exciting and promising strategies for triple-negative breast cancer (TNBC) therapy. The purpose of this study is to assess PARP1 expression in TNBCs and to evaluate the association between polymorphisms in PARP1 promoter or 3’ untranslated region (3’UTR) and PARP1 expression. It was found that PARP1 was overexpressed in nuclear (nPARP1), cytoplasm (cPARP1) and nuclear-cytoplasmic coexisting (co...

  3. Common and unique genetic interactions of the poly(ADP-ribose) polymerases PARP1 and PARP2 with DNA double-strand break repair pathways.

    Science.gov (United States)

    Ghosh, Rajib; Roy, Sanchita; Kamyab, Johan; Dantzer, Francoise; Franco, Sonia

    2016-09-01

    In mammalian cells, chromatin poly(ADP-ribos)ylation (PARylation) at sites of DNA Double-Strand Breaks (DSBs) is mediated by two highly related enzymes, PARP1 and PARP2. However, enzyme-specific genetic interactions with other DSB repair factors remain largely undefined. In this context, it was previously shown that mice lacking PARP1 and H2AX, a histone variant that promotes DSB repair throughout the cell cycle, or the core nonhomologous end-joining (NHEJ) factor Ku80 are not viable, while mice lacking PARP1 and the noncore NHEJ factor DNA-PKcs are severely growth retarded and markedly lymphoma-prone. Here, we have examined the requirement for PARP2 in these backgrounds. We find that, like PARP1, PARP2 is essential for viability in mice lacking H2AX. Moreover, treatment of H2AX-deficient primary fibroblasts or B lymphocytes with PARP inhibitors leads to activation of the G2/M checkpoint and accumulation of chromatid-type breaks in a lineage- and gene-dose dependent manner. In marked contrast to PARP1, loss of PARP2 does not result in additional phenotypes in growth, development or tumorigenesis in mice lacking either Ku80 or DNA-PKcs. Altogether these findings highlight specific nonoverlapping functions of PARP1 and PARP2 at H2AX-deficient chromatin during replicative phases of the cell cycle and uncover a unique requirement for PARP1 in NHEJ-deficient cells. PMID:27373144

  4. Poly (ADP-ribose polymerase inhibitor: an evolving paradigm in the treatment of prostate cancer

    Directory of Open Access Journals (Sweden)

    Jingsong Zhang

    2014-06-01

    Full Text Available Recent phase I studies have reported single-agent activities of poly (ADP-ribose polymerase (PARP inhibitor in sporadic and in BRCA-mutant prostate cancers. Two of the most common genetic alterations in prostate cancer, ETS gene rearrangement and loss of PTEN, have been linked to increased sensitivity to PARP inhibitor in preclinical models. Emerging evidence also suggests that PARP1 plays an important role in mediating the transcriptional activities of androgen receptor (AR and ETS gene rearrangement. In this article, the preclinical work and early-phase clinical trials in developing PARP inhibitor-based therapy as a new treatment paradigm for metastatic prostate cancer are reviewed.

  5. Sumoylation of poly(ADP-ribose) polymerase 1 inhibits its acetylation and restrains transcriptional coactivator function

    OpenAIRE

    Messner, S.; Schuermann, D.; Altmeyer, M; Kassner, I; Schmidt, D; Schär, P; Müller, S.; Hottiger, M O

    2009-01-01

    Poly(ADP-ribose) polymerase 1 (PARP1) is a chromatin-associated nuclear protein and functions as a molecular stress sensor. At the cellular level, PARP1 has been implicated in a wide range of processes, such as maintenance of genome stability, cell death, and transcription. PARP1 functions as a transcriptional coactivator of nuclear factor B (NF-B) and hypoxia inducible factor 1 (HIF1). In proteomic studies, PARP1 was found to be modified by small ubiquitin-like mod...

  6. Postnatal Age Influences Hypoglycemia-induced Poly(ADP-ribose) Polymerase-1 Activation in the Brain Regions of Rats

    OpenAIRE

    Rao, Raghavendra; Sperr, Dustin; Ennis, Kathleen; Tran, Phu

    2009-01-01

    Poly(ADP-ribose) polymerase-1 (PARP-1) overactivation plays a significant role in hypoglycemia-induced brain injury in adult rats. To determine the influence of postnatal age on PARP-1 activation, developing and adult male rats were subjected to acute hypoglycemia of equivalent severity and duration. The expression of PARP-1 and its downstream effectors, apoptosis inducing factor (Aifm1), caspase 3 (Casp3), NF-κB (Nfkb1) and bcl-2 (Bcl2), and cellular poly(ADP-ribose) (PAR) polymer expression...

  7. Effect and mechanism of poly (ADP-ribose) polymerase-1 in aldosterone-induced apoptosis

    OpenAIRE

    Qiao, Weiwei; Zhang, Weili; Shao, Shuhong; GAI, YUSHENG; Zhang, Mingxiang

    2015-01-01

    The present study aimed to investigate the effects of aldosterone on vascular endothelial cells and the viability of poly (ADP-ribose) polymerase 1 (PARP1) in cells, and to examine the molecular mechanisms underlying the effects of aldosterone on vascular endothelial cell injury. Cultured endothelial cells were treated either with different concentrations of aldosterone for the same duration or with the same concentrations of aldosterone for different durations, and the levels of apoptosis an...

  8. Recognition of Platinum-DNA Damage by Poly(ADP-Ribose) Polymerase-1†

    OpenAIRE

    Zhu, Guangyu; Chang, Paul; Lippard, Stephen J.

    2010-01-01

    Poly(ADP-ribose) polymerase-1 (PARP-1) was recently identified as a platinum DNA damage response protein. To investigate the binding properties of PARP-1 to different platinum-DNA adducts in greater detail, biotinylated DNA probes containing a site-specific cisplatin 1,2-d(GpG) or 1,3-d(GpTpG) intrastrand cross-link, or a cisplatin 5’-d(GC)/5’-d(GC) interstrand cross-link (ICL) were utilized in binding assays with cell free extracts (CFEs) in vitro. The activated state of PARP-1 was generated...

  9. Active site fingerprinting and pharmacophore screening strategies for the identification of dual inhibitors of protein kinase C [Formula: see text] and poly (ADP-ribose) polymerase-1 (PARP-1).

    Science.gov (United States)

    Chadha, Navriti; Silakari, Om

    2016-08-01

    Current clinical studies have revealed that diabetic complications are multifactorial disorders that target two or more pathways. The majority of drugs in clinical trial target aldose reductase and protein kinase C ([Formula: see text]), while recent studies disclosed a significant role played by poly (ADP-ribose) polymerase-1 (PARP-1). In light of this, the current study was aimed to identify novel dual inhibitors of [Formula: see text] and PARP-1 using a pharmaco-informatics methodology. Pharmacophore-based 3D QSAR models for these two targets were generated using HypoGen and used to screen three commercially available chemical databases to identify dual inhibitors of [Formula: see text] and PARP-1. Overall, 18 hits were obtained from the screening process; the hits were filtered based on their drug-like properties and predicted binding affinities (docking analysis). Important amino acid residues were predicted by developing a fingerprint of the active site using alanine-scanning mutagenesis and molecular dynamics. The stability of the complexes (18 hits with both proteins) and their final binding orientations were investigated using molecular dynamics simulations. Thus, novel hits have been predicted to have good binding affinities for [Formula: see text] and PARP-1 proteins, which could be further investigated for in vitro/in vivo activity. PMID:27216445

  10. Inhibition of poly(ADP-ribose) polymerase interferes with Trypanosoma cruzi infection and proliferation of the parasite.

    Science.gov (United States)

    Vilchez Larrea, Salomé C; Haikarainen, Teemu; Narwal, Mohit; Schlesinger, Mariana; Venkannagari, Harikanth; Flawiá, Mirtha M; Villamil, Silvia H Fernández; Lehtiö, Lari

    2012-01-01

    Poly(ADP-ribosylation) is a post-translational covalent modification of proteins catalyzed by a family of enzymes termed poly(ADP-ribose) polymerases (PARPs). In the human genome, 17 different genes have been identified that encode members of the PARP superfamily. Poly (ADP-ribose) metabolism plays a role in a wide range of biological processes. In Trypanosoma cruzi, PARP enzyme appears to play a role in DNA repair mechanisms and may also be involved in controlling the different phases of cell growth. Here we describe the identification of potent inhibitors for T. cruzi PARP with a fluorescence-based activity assay. The inhibitors were also tested on T. cruzi epimastigotes, showing that they reduced ADP-ribose polymer formation in vivo. Notably, the identified inhibitors are able to reduce the growth rate of T. cruzi epimastigotes. The best inhibitor, Olaparib, is effective at nanomolar concentrations, making it an efficient chemical tool for chacterization of ADP-ribose metabolism in T. cruzi. PARP inhibition also decreases drastically the amount of amastigotes but interestingly has no effect on the amount of trypomastigotes in the cell culture. Knocking down human PARP-1 decreases both the amount of amastigotes and trypomastigotes in cell culture, indicating that the effect would be mainly due to inhibition of human PARP-1. The result suggests that the inhibition of PARP could be a potential way to interfere with T. cruzi infection. PMID:23049934

  11. The Role of Poly(ADP-ribose Polymerase-1 in Rheumatoid Arthritis

    Directory of Open Access Journals (Sweden)

    Samuel García

    2015-01-01

    Full Text Available Poly(ADP-ribose polymerase-1 (PARP-1 is a nuclear enzyme with a crucial role in the maintenance of genomic stability. In addition to the role of PARP-1 in DNA repair, multiple studies have also demonstrated its involvement in several inflammatory diseases, such as septic shock, asthma, atherosclerosis, and stroke, as well as in cancer. In these diseases, the pharmacological inhibition of PARP-1 has shown a beneficial effect, suggesting that PARP-1 regulates their inflammatory processes. In recent years, we have studied the role of PARP-1 in rheumatoid arthritis, as have other researchers, and the results have shown that PARP-1 has an important function in the development of this disease. This review summarizes current knowledge on the effects of PARP-1 in rheumatoid arthritis.

  12. Poly(ADP-Ribose) Polymerase 1 Is Not Strictly Required for Infection of Murine Cells by Retroviruses

    OpenAIRE

    Siva, Amara C; Bushman, Frederic

    2002-01-01

    The DNA-breaking and -joining steps initiating retroviral integration are well understood, but the later steps, thought to be carried out by cellular DNA repair enzymes, have not been fully characterized. Poly(ADP-ribose) polymerase 1 (PARP-1) has been proposed to play a role late during retroviral integration, because infection by human immunodeficiency virus (HIV)-based vectors was reported to be strongly inhibited in PARP-1-deficient fibroblasts. PARP-1, a nuclear enzyme, binds tightly to ...

  13. Cisplatin induces primary necrosis through poly(ADP-ribose) polymerase 1 activation in kidney proximal tubular cells

    OpenAIRE

    Park, Seulgee; Yoon, Sang Pil; Kim, Jinu

    2015-01-01

    Treatment with cisplatin for cancer therapy has a major side effect such as nephrotoxicity; however, the role of poly (ADP-ribose) polymerase 1 (PARP1) in necrosis in response to cisplatin nephrotoxicity remains to be defined. Here we report that cisplatin induces primary necrosis through PARP1 activation in kidney proximal tubular cells derived from human, pig and mouse. Treatment with high dose of cisplatin for 4 and 8 hours induced primary necrosis, as represented by the percentage of prop...

  14. Differential Role of Poly(ADP-ribose polymerase in D. discoideum growth and development

    Directory of Open Access Journals (Sweden)

    Begum Rasheedunnisa

    2011-03-01

    Full Text Available Abstract Background Poly(ADP-ribose polymerase is evolutionarily conserved as a responder to various forms of stress. Though PARP's role in cell death is well addressed, its role in development and multicellularity is still an enigma. We have previously reported the role of PARP in oxidative stress induced delayed development of D. discoideum. Results In the current study we highlight the involvement of PARP during D. discoideum development. Oxidative stress affects expression of aca and cAR1 thus affecting aggregation. Although parp expression is not affected during oxidative stress but it is involved during normal development as confirmed by our PARP down-regulation studies. Constitutive PARP down-regulation resulted in blocked development while no effect was observed on D. discoideum growth. Interestingly, stage specific PARP down-regulation arrested development at the slug stage. Conclusion These results emphasize that PARP is essential for complex differentiation and its function may be linked to multicellularity. This is the first report where the involvement of PARP during normal multicellular development in D. discoideum, an ancient eukaryote, is established which could be of evolutionary significance. Thus our study adds one more role to the multitasking function of PARP.

  15. Structural Requirements of Some 2-(1-Propylpiperidin-4-yl)-1H-benzimidazole-4-carboxamide Derivatives as Poly (ADP-Ribose) Polymerase (PARP) for the Treatment of Cancer: QSAR Approach.

    Science.gov (United States)

    Sharma, Mukesh C

    2016-03-01

    The present study is aimed to elucidate the structural features of substituted 2-(1-propylpiperidin-4-yl)-1H-benzimidazole-4-carboxamide required for poly (ADP-ribose) polymerase inhibition and to obtain predictive 2D QSAR models to guide the rational synthesis of novel poly (ADP-ribose) polymerase inhibitors. The statistical analysis has shown that excellent results are obtained by using partial least regression based on simulated annealing method. The best model was selected based on the highest correlation coefficient r (2) = 0.8590, and cross-validated squared correlation coefficient q (2) = 0.7875 with external predictive ability of [Formula: see text] was developed by stepwise PLS method with the descriptors like T_N_F_1, SdsCHcount, and Rotatable Bond Count. The generated models provide insight into the influence of various interactive fields on the activity and, thus, can help in designing and forecasting the inhibition activity of novel (ADP-ribose) polymerase molecules. PMID:26205198

  16. Poly(ADP-ribose) polymerase-1 protects from oxidative stress induced endothelial dysfunction

    International Nuclear Information System (INIS)

    Highlights: ► The nuclear enzyme PARP-1 is a downstream effector of oxidative stress. ► PARP-1 protects from oxidative stress induced endothelial dysfunction. ► This effect is mediated through inhibition of vasoconstrictor prostanoid production. ► Thus, PARP-1 may play a protective role as antioxidant defense mechanism. -- Abstract: Background: Generation of reactive oxygen species (ROS) is a key feature of vascular disease. Activation of the nuclear enzyme poly (adenosine diphosphate [ADP]-ribose) polymerase-1 (PARP-1) is a downstream effector of oxidative stress. Methods: PARP-1(−/−) and PARP-1(+/+) mice were injected with paraquat (PQ; 10 mg/kg i.p.) to induce intracellular oxidative stress. Aortic rings were suspended in organ chambers for isometric tension recording to analyze vascular function. Results: PQ treatment markedly impaired endothelium-dependent relaxations to acetylcholine in PARP-1(−/−), but not PARP-1(+/+) mice (p < 0.0001). Maximal relaxation was 45% in PQ treated PARP-1(−/−) mice compared to 79% in PARP-1(+/+) mice. In contrast, endothelium-independent relaxations to sodium nitroprusside (SNP) were not altered. After PQ treatment, L-NAME enhanced contractions to norepinephrine by 2.0-fold in PARP-1(−/−) mice, and those to acetylcholine by 3.3-fold, respectively, as compared to PARP-1(+/+) mice. PEG-superoxide dismutase (SOD) and PEG-catalase prevented the effect of PQ on endothelium-dependent relaxations to acetylcholine in PARP-1(−/−) mice (p < 0.001 vs. PQ treated PARP-1(+/+) mice. Indomethacin restored endothelium-dependent relaxations to acetylcholine in PQ treated PARP-1(−/−) mice (p < 0.05 vs. PQ treated PARP-1(+/+). Conclusion: PARP-1 protects from acute intracellular oxidative stress induced endothelial dysfunction by inhibiting ROS induced production of vasoconstrictor prostanoids.

  17. Poly(ADP-ribose) polymerase-1 protects from oxidative stress induced endothelial dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Gebhard, Catherine; Staehli, Barbara E. [Cardiovascular Research, Physiology Institute, University of Zurich, Winterthurerstrasse 190, 8057 Zurich (Switzerland); Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Winterthurerstrasse 190, 8057 Zurich (Switzerland); Cardiology, Cardiovascular Center, University Hospital Zurich, Raemistrasse 100, 8091 Zurich (Switzerland); Shi, Yi; Camici, Giovanni G.; Akhmedov, Alexander; Hoegger, Lisa; Lohmann, Christine [Cardiovascular Research, Physiology Institute, University of Zurich, Winterthurerstrasse 190, 8057 Zurich (Switzerland); Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Winterthurerstrasse 190, 8057 Zurich (Switzerland); Matter, Christian M. [Cardiovascular Research, Physiology Institute, University of Zurich, Winterthurerstrasse 190, 8057 Zurich (Switzerland); Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Winterthurerstrasse 190, 8057 Zurich (Switzerland); Cardiology, Cardiovascular Center, University Hospital Zurich, Raemistrasse 100, 8091 Zurich (Switzerland); Hassa, Paul O.; Hottiger, Michael O. [Institute of Veterinary Biochemistry and Molecular Biology, University of Zurich, Winterthurerstrasse 190, 8057 Zurich (Switzerland); Malinski, Tadeusz [Department of Chemistry and Biochemistry, Ohio University, Athens, OH (United States); Luescher, Thomas F. [Cardiovascular Research, Physiology Institute, University of Zurich, Winterthurerstrasse 190, 8057 Zurich (Switzerland); Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Winterthurerstrasse 190, 8057 Zurich (Switzerland); Cardiology, Cardiovascular Center, University Hospital Zurich, Raemistrasse 100, 8091 Zurich (Switzerland); and others

    2011-11-04

    Highlights: Black-Right-Pointing-Pointer The nuclear enzyme PARP-1 is a downstream effector of oxidative stress. Black-Right-Pointing-Pointer PARP-1 protects from oxidative stress induced endothelial dysfunction. Black-Right-Pointing-Pointer This effect is mediated through inhibition of vasoconstrictor prostanoid production. Black-Right-Pointing-Pointer Thus, PARP-1 may play a protective role as antioxidant defense mechanism. -- Abstract: Background: Generation of reactive oxygen species (ROS) is a key feature of vascular disease. Activation of the nuclear enzyme poly (adenosine diphosphate [ADP]-ribose) polymerase-1 (PARP-1) is a downstream effector of oxidative stress. Methods: PARP-1(-/-) and PARP-1(+/+) mice were injected with paraquat (PQ; 10 mg/kg i.p.) to induce intracellular oxidative stress. Aortic rings were suspended in organ chambers for isometric tension recording to analyze vascular function. Results: PQ treatment markedly impaired endothelium-dependent relaxations to acetylcholine in PARP-1(-/-), but not PARP-1(+/+) mice (p < 0.0001). Maximal relaxation was 45% in PQ treated PARP-1(-/-) mice compared to 79% in PARP-1(+/+) mice. In contrast, endothelium-independent relaxations to sodium nitroprusside (SNP) were not altered. After PQ treatment, L-NAME enhanced contractions to norepinephrine by 2.0-fold in PARP-1(-/-) mice, and those to acetylcholine by 3.3-fold, respectively, as compared to PARP-1(+/+) mice. PEG-superoxide dismutase (SOD) and PEG-catalase prevented the effect of PQ on endothelium-dependent relaxations to acetylcholine in PARP-1(-/-) mice (p < 0.001 vs. PQ treated PARP-1(+/+) mice. Indomethacin restored endothelium-dependent relaxations to acetylcholine in PQ treated PARP-1(-/-) mice (p < 0.05 vs. PQ treated PARP-1(+/+). Conclusion: PARP-1 protects from acute intracellular oxidative stress induced endothelial dysfunction by inhibiting ROS induced production of vasoconstrictor prostanoids.

  18. Differential and Concordant Roles for Poly(ADP-Ribose) Polymerase 1 and Poly(ADP-Ribose) in Regulating WRN and RECQL5 Activities.

    Science.gov (United States)

    Khadka, Prabhat; Hsu, Joseph K; Veith, Sebastian; Tadokoro, Takashi; Shamanna, Raghavendra A; Mangerich, Aswin; Croteau, Deborah L; Bohr, Vilhelm A

    2015-12-01

    Poly(ADP-ribose) (PAR) polymerase 1 (PARP1) catalyzes the poly(ADP-ribosyl)ation (PARylation) of proteins, a posttranslational modification which forms the nucleic acid-like polymer PAR. PARP1 and PAR are integral players in the early DNA damage response, since PARylation orchestrates the recruitment of repair proteins to sites of damage. Human RecQ helicases are DNA unwinding proteins that are critical responders to DNA damage, but how their recruitment and activities are regulated by PARPs and PAR is poorly understood. Here we report that all human RecQ helicases interact with PAR noncovalently. Furthermore, we define the effects that PARP1, PARylated PARP1, and PAR have on RECQL5 and WRN, using both in vitro and in vivo assays. We show that PARylation is involved in the recruitment of RECQL5 and WRN to laser-induced DNA damage and that RECQL5 and WRN have differential responses to PARylated PARP1 and PAR. Furthermore, we show that the loss of RECQL5 or WRN resulted in increased sensitivity to PARP inhibition. In conclusion, our results demonstrate that PARP1 and PAR actively, and in some instances differentially, regulate the activities and cellular localization of RECQL5 and WRN, suggesting that PARylation acts as a fine-tuning mechanism to coordinate their functions in time and space during the genotoxic stress response. PMID:26391948

  19. SIRT1 promotes cell survival under stress by deacetylation-dependent deactivation of poly(ADP-ribose) polymerase 1

    OpenAIRE

    Rajamohan, S B; V. B. Pillai; Gupta, M.; Sundaresan, N R; Birukov, K G; Samant, S.; Hottiger, M O; Gupta, M P

    2009-01-01

    Poly(ADP-ribose) polymerase 1 (PARP1) and SIRT1 deacetylase are two NAD-dependent enzymes which play major roles in the decision of a cell to live or to die in a stress situation. Because of the dependence of both enzymes on NAD, cross talk between them has been suggested. Here, we show that PARP1 is acetylated after stress of cardiomyocytes, resulting in the activation of PARP1, which is independent of DNA damage. SIRT1 physically binds to and deacetylates PARP1. Increased acetylation of PAR...

  20. Poly (ADP-ribose polymerase 1 protein expression in normal and neoplastic prostatic tissue

    Directory of Open Access Journals (Sweden)

    M. Salemi

    2013-04-01

    Full Text Available A genetic background has been implicated in the development of prostate cancer. Protein microarrays have enabled the identification of proteins, some of which associated with apoptosis, that may play a role in the development of such a tumor. Inhibition of apoptosis is a co-factor that contributes to the onset and progression of prostate cancer, though the molecular mechanisms are not entirely understood. Poly (ADP-ribose polymerase 1 (PARP-1 gene is required for translocation of the apoptosis-inducing factor (AIF from the mitochondria to the nucleus. Hence, it is involved in programmed cell death. Different PARP-1 gene expression has been observed in various tumors such as glioblastoma, lung, ovarian, endometrial, and skin cancers. We evaluated the expression of PARP-1 protein in prostatic cancer and normal prostate tissues by immunohistochemistry in 40 men with prostate cancer and in 37 normal men. Positive nuclear PARP-1 staining was found in all samples (normal prostate and prostate cancer tissues. No cytoplasmic staining was observed in any sample. PARP-1-positive cells resulted significantly higher in patients with prostate carcinoma compared with controls (P<0.001. PARP-1 over-expression in prostate cancer tissue compared with normal prostate suggests a greater activity of PARP-1 in these tumors. These findings suggest that PARP-1 expression in prostate cancer is an attempt to trigger apoptosis in this type of tumor similarly to what reported in other cancers.

  1. Poly (ADP-ribose) polymerases inhibitor, Zj6413, as a potential therapeutic agent against breast cancer.

    Science.gov (United States)

    Zhou, Qin; Ji, Ming; Zhou, Jie; Jin, Jing; Xue, Nina; Chen, Ju; Xu, Bailing; Chen, Xiaoguang

    2016-05-01

    Poly (ADP-ribose) polymerases (PARPs) facilitate repairing of cancer cell DNA damage as a mean to promote cancer proliferation and metastasis. Inhibitors of PARPs which interfering DNA repair, in context of defects in other DNA repair mechanisms, can thus be potentially exploited to inhibit or even kill cancer cells. However, nondiscriminatory inhibition of PARPs, such as PARP2, may lead to undesired consequences. Here, we demonstrated the design and development of the Zj6413 as a potent and selective PARP1 catalytic inhibitor. It trapped PARP1/2 at damaged sites of DNA. As expected, the Zj6413 showed notable anti-tumor activity against breast cancer gene (BRCA) deficient triple negative breast cancers (TNBCs). Zj6413 treated breast cancers (BCs) showed an elevated level of DNA damage evidenced by the accumulation of γ-H2AX foci and DNA damaged related proteins. Zj6413 also induced G2/M arrest and cell death in the MX-1, MDA-MB-453 BC cells, exerted chemo-sensitizing effect on BRCA proficient cancer cells and potentiated Temozolomide (TMZ)'s cytotoxicity in MX-1 xenograft tumors mice. In conclusion, our study provided evidence that a new PARP inhibitor strongly inhibited the catalytic activity of PARPs, trapped them on nicked DNA and damaged the cancer cells, eventually inhibiting the growth of breast tumor cells in vitro and in vivo. PMID:26920250

  2. DNA vector-based RNAi approach for stable depletion of poly(ADP-ribose) polymerase-1

    International Nuclear Information System (INIS)

    RNA-mediated interference (RNAi) is a powerful technique that is now being used in mammalian cells to specifically silence a gene. Some recent studies have used this technique to achieve variable extent of depletion of a nuclear enzyme poly(ADP-ribose) polymerase-1 (PARP-1). These studies reported either transient silencing of PARP-1 using double-stranded RNA or stable silencing of PARP-1 with a DNA vector which was introduced by a viral delivery system. In contrast, here we report that a simple RNAi approach which utilizes a pBS-U6-based DNA vector containing strategically selected PARP-1 targeting sequence, introduced in the cells by conventional CaPO4 protocol, can be used to achieve stable and specific silencing of PARP-1 in different types of cells. We also provide a detailed strategy for selection and cloning of PARP-1-targeting sequences for the DNA vector, and demonstrate that this technique does not affect expression of its closest functional homolog PARP-2

  3. Direct phosphorylation and regulation of poly(ADP-ribose) polymerase-1 by extracellular signal-regulated kinases 1/2

    OpenAIRE

    Kauppinen, Tiina M; Chan, Wai Y.; Suh, Sang Won; Wiggins, Amanda K.; Eric J. Huang; Swanson, Raymond A.

    2006-01-01

    Sustained activation of poly(ADP-ribose) polymerase-1 (PARP-1) and extracellular signal-regulated kinases 1/2 (ERK1/2) both promote neuronal death. Here we identify a direct link between these two cell death pathways. In a rat model of hypoglycemic brain injury, neuronal PARP-1 activation and subsequent neuronal death were blocked by the ERK1/2 inhibitor 2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one (PD98059). In neuron cultures, PARP-1-mediated neuronal death induced by N-methyl-d-aspart...

  4. p21CDKN1A Regulates the Binding of Poly(ADP-Ribose) Polymerase-1 to DNA Repair Intermediates

    OpenAIRE

    Dutto, Ilaria; Sukhanova, Maria; Tillhon, Micol; Cazzalini, Ornella; Stivala, Lucia A.; Scovassi, A. Ivana; Lavrik, Olga; Prosperi, Ennio

    2016-01-01

    The cell cycle inhibitor p21CDKN1A was previously found to interact directly with DNA nick-sensor poly(ADP-ribose) polymerase-1 (PARP-1) and to promote base excision repair (BER). However, the molecular mechanism responsible for this BER-related association of p21 with PARP-1 remains to be clarified. In this study we investigate the capability of p21 to influence PARP-1 binding to DNA repair intermediates in a reconstituted BER system in vitro. Using model photoreactive BER substrates contain...

  5. Transcriptional regulation by Poly(ADP-ribose polymerase-1 during T cell activation

    Directory of Open Access Journals (Sweden)

    Parrilla Pascual

    2008-04-01

    Full Text Available Abstract Background Accumulating evidence suggests an important role for the enzyme poly(ADP-ribose polymerase-1 (PARP-1 as an integral part of the gene expression regulatory machinery during development and in response to specific cellular signals. PARP-1 might modulate gene expression through its catalytic activity leading to poly(ADP-ribosylation of nuclear proteins or by its physical association with relevant proteins. Recently, we have shown that PARP-1 is activated during T cell activation. However, the proposed role of PARP-1 in reprogramming T cell gene expression upon activation remains largely unexplored. Results In the present study we use oligonucleotide microarray analysis to gain more insight into the role played by PARP-1 during the gene expression reprogramming that takes place in T cells upon activation with anti-CD3 stimulation alone, or in combination with anti-CD28 co-stimulation. We have identified several groups of genes with expression modulated by PARP-1. The expression of 129 early-response genes to anti-CD3 seems to be regulated by PARP-1 either in a positive (45 genes or in a negative manner (84 genes. Likewise, in the presence of co-stimulation (anti-CD3 + anti-CD28 stimulation, the expression of 203 genes is also regulated by PARP-1 either up (173 genes or down (30 genes. Interestingly, PARP-1 deficiency significantly alters expression of genes associated with the immune response such as chemokines and genes involved in the Th1/Th2 balance. Conclusion This study provides new insights into changes in gene expression mediated by PARP-1 upon T cell activation. Pathway analysis of PARP-1 as a nuclear signalling molecule in T cells would be of relevance for the future development of new therapeutic approaches targeting PARP-1 in the acquired immune response.

  6. NF-κB transcriptional activation by TNFα requires phospholipase C, extracellular signal-regulated kinase 2 and poly(ADP-ribose) polymerase-1

    OpenAIRE

    Vuong, Billy; Hogan-Cann, Adam D. J.; Alano, Conrad C.; Stevenson, Mackenzie; Chan, Wai Yee; Anderson, Christopher M.; Swanson, Raymond A.; Kauppinen, Tiina M

    2015-01-01

    Background The nuclear enzyme poly(ADP-ribose) polymerase-1 (PARP-1) is required for pro-inflammatory effects of TNFα. Our previous studies demonstrated that PARP-1 mediates TNFα-induced NF-κB activation in glia. Here, we evaluated the mechanisms by which TNFα activates PARP-1 and PARP-1 mediates NF-κB activation. Methods Primary cultures of mouse cortical astrocytes and microglia were treated with TNFα and suitable signaling pathway modulators (pharmacological and molecular). Outcome measure...

  7. Poly (ADP) ribose polymerase inhibition: A potential treatment of malignant peripheral nerve sheath tumor.

    Science.gov (United States)

    Kivlin, Christine M; Watson, Kelsey L; Al Sannaa, Ghadah A; Belousov, Roman; Ingram, Davis R; Huang, Kai-Lieh; May, Caitlin D; Bolshakov, Svetlana; Landers, Sharon M; Kalam, Azad Abul; Slopis, John M; McCutcheon, Ian E; Pollock, Raphael E; Lev, Dina; Lazar, Alexander J; Torres, Keila E

    2016-02-01

    Poly (ADP) ribose polymerase (PARP) inhibitors, first evaluated nearly a decade ago, are primarily used in malignancies with known defects in DNA repair genes, such as alterations in breast cancer, early onset 1/2 (BRCA1/2). While no specific mutations in BRCA1/2 have been reported in malignant peripheral nerve sheath tumors (MPNSTs), MPNST cells could be effectively targeted with a PARP inhibitor to drive cells to synthetic lethality due to their complex karyotype and high level of inherent genomic instability. In this study, we assessed the expression levels of PARP1 and PARP2 in MPNST patient tumor samples and correlated these findings with overall survival. We also determined the level of PARP activity in MPNST cell lines. In addition, we evaluated the efficacy of the PARP inhibitor AZD2281 (Olaparib) in MPNST cell lines. We observed decreased MPNST cell proliferation and enhanced apoptosis in vitro at doses similar to, or less than, the doses used in cell lines with established defective DNA repair genes. Furthermore, AZD2281 significantly reduced local growth of MPNST xenografts, decreased the development of macroscopic lung metastases, and increased survival of mice with metastatic disease. Our results suggest that AZD2281 could be an effective therapeutic option in MPNST and should be further investigated for its potential clinical use in this malignancy. PMID:26650448

  8. Poly(ADP)-Ribose Polymerase-1 Inhibitors as a Potential Treatment for Cocaine Addiction.

    Science.gov (United States)

    Scobie, Kimberly N

    2015-01-01

    As of 2008, according to the National Survey on Drug Use and Health, nearly 1.4 million Americans met the Diagnostic and Statistical Manual of Mental Disorders criteria for dependence or abuse of cocaine (in any form) in the past 12 months. However, there are no treatments for cocaine use disorders approved by the Federal Drug Administration (FDA). Alterations in gene regulation contribute significantly to the changes that occur in the brain, both structurally and functionally, and the resultant addictive phenotype that occurs with chronic exposure to drugs of abuse. The Emerging Targets of Cocaine Use Disorders meeting sought to explore novel targets for the treatment of stimulant use disorder. The evidence for a role of one novel target, Poly(ADP)-ribose polymerase-1 (PARP-1), was presented at the meeting and will be summarized in this review. PMID:26022260

  9. Poly(ADP-Ribose) Polymerase 1 Promotes Oxidative-Stress-Induced Liver Cell Death via Suppressing Farnesoid X Receptor α

    OpenAIRE

    Wang, Cheng; Zhang, Fengxiao; Wang, Lin; Zhang, Yanqing; Li, Xiangrao; Huang, Kun; Du, Meng; Liu, Fangmei; Huang, Shizheng; Guan, Youfei; Huang, Dan; Huang, Kai

    2013-01-01

    Farnesoid X receptor α (FXR) is highly expressed in the liver and regulates the expression of various genes involved in liver repair. In this study, we demonstrated that activated poly(ADP-ribose) polymerase 1 (PARP1) promoted hepatic cell death by inhibiting the expression of FXR-dependent hepatoprotective genes. PARP1 could bind to and poly(ADP-ribosyl)ate FXR. Poly(ADP-ribosyl)ation dissociated FXR from the FXR response element (FXRE), present in the promoters of target genes, and suppress...

  10. Transcription regulation of TNF-α-early response genes by poly(ADP-ribose) polymerase-1 in murine heart endothelial cells

    OpenAIRE

    Carrillo, Ana; Monreal, Yolanda; Ramírez, Pablo; Marín, Luis; Parrilla, Pascual; Oliver, Francisco Javier; Yélamos, José

    2004-01-01

    [EN] Poly(ADP-ribose) polymerase-1 (PARP-1) has been involved in endothelial cell dysfunction associated with various pathophysiological conditions. The intrinsic mechanism of PARP-1-mediated endothelial cell dysfunction could be related to PARP-1 overactivation, NAD+ consumption and ATP depletion. An alternative way could involve transcription regulation. By using high-density microarrays, we examined early tumor necrosis factor α(TNF- α)- stimulated gene expressio...

  11. Poly(ADP-ribose) polymerase inhibition reverses vascular dysfunction after γ-irradiation

    International Nuclear Information System (INIS)

    Purpose: The generation of reactive oxygen species during γ-irradiation may induce DNA damage, leading to activation of the nuclear enzyme poly(adenosine diphosphate [ADP]-ribose) polymerase (PARP) culminating in endothelial dysfunction. In the present study, we assessed the effect of PARP inhibition on changes in vascular function after acute and short-term irradiation. Methods and Materials: In the acute experiments, aortic rings were exposed to 20 Gy of γ-irradiation. The aortae were harvested after 1 or 7 days. Two additional groups received the ultrapotent PARP inhibitor, INO-1001, for 1 or 7 days after irradiation. The aortic rings were precontracted by phenylephrine and relaxation to acetylcholine and sodium nitroprusside were studied. Results: The vasoconstrictor response to phenylephrine was significantly lower both acutely and 1 and 7 days after irradiation. Vasorelaxation to acetylcholine and sodium nitroprusside was not impaired acutely after irradiation. One and seven days after irradiation, vasorelaxation to acetylcholine and sodium nitroprusside was significantly enhanced. Treatment with INO-1001 reversed vascular dysfunction after irradiation. Conclusion: Vascular dysfunction was observed 1 and 7 days after irradiation, as evidenced by reduced vasoconstriction, coupled with endothelium-dependent and -independent hyperrelaxation. PARP inhibition restored vascular function and may, therefore, be suitable to reverse vascular dysfunction after irradiation

  12. Poly(ADP-ribose) polymerase 1 regulates activity of DNA polymerase {beta} in long patch base excision repair

    Energy Technology Data Exchange (ETDEWEB)

    Sukhanova, Maria; Khodyreva, Svetlana [Institute of Chemical Biology and Fundamental Medicine SB RAS, Novosibirsk (Russian Federation); Lavrik, Olga, E-mail: lavrik@niboch.nsc.ru [Institute of Chemical Biology and Fundamental Medicine SB RAS, Novosibirsk (Russian Federation)

    2010-03-01

    Poly(ADP-ribose)polymerase 1 (PARP1), functioning as DNA nick-sensor, interacts with base excision repair (BER) DNA intermediates containing single-strand breaks. When bound to DNA breaks, PARP1 catalyzes synthesis of poly(ADP-ribose) covalently attached to itself and some nuclear proteins. Autopoly(ADP-ribosyl)ation of PARP1 facilitates its dissociation from DNA breaks and is considered as a factor regulating DNA repair. In the study, using system reconstituted from purified BER proteins, bovine testis nuclear extract and model BER DNA intermediates, we examined the influence of PARP1 and its autopoly(ADP-ribosyl)ation on DNA polymerase {beta} (Pol {beta})-mediated long patch (LP) BER DNA synthesis that is accomplished through a cooperation between Pol {beta} and apurinic/apyrimidinic endonuclease1 (APE1) or flap endonuclease 1 (FEN1) and gap-filling activity of Pol {beta}. PARP1 upon interaction with nicked LP BER DNA intermediated, formed after gap-filling, was shown to suppress the subsequent steps in LP pathway. PARP1 interferes with APE1-dependent stimulation of DNA synthesis by Pol {beta} via strand-displacement mechanism. PARP1 also represses Pol {beta}/FEN1-mediated LP BER DNA synthesis via a 'gap translation' mechanism inhibiting FEN1 activity on the nicked DNA intermediate. Poly(ADP-ribosyl)ation of PARP1 abolishes its inhibitory influence on LP BER DNA synthesis catalyzed by Pol {beta} both via APE1-mediated strand-displacement and FEN1-mediated 'gap translation' mechanism. Thus PARP1 may act as a negative regulator of Pol {beta} activity in LP BER pathway and poly(ADP-ribosyl)ation of PARP1 seems to play a critical role in enablement of Pol {beta}-mediated DNA synthesis in this process. In contrast, interaction of PARP1 with one nucleotide gapped DNA mimicking the intermediate of short patch (SP) BER slightly inhibits the gap-filling activity of Pol {beta} and the overall efficiency of SP BER is practically unaffected by PARP1. Thus

  13. Poly(ADP-ribose) polymerase 1 regulates activity of DNA polymerase β in long patch base excision repair

    International Nuclear Information System (INIS)

    Poly(ADP-ribose)polymerase 1 (PARP1), functioning as DNA nick-sensor, interacts with base excision repair (BER) DNA intermediates containing single-strand breaks. When bound to DNA breaks, PARP1 catalyzes synthesis of poly(ADP-ribose) covalently attached to itself and some nuclear proteins. Autopoly(ADP-ribosyl)ation of PARP1 facilitates its dissociation from DNA breaks and is considered as a factor regulating DNA repair. In the study, using system reconstituted from purified BER proteins, bovine testis nuclear extract and model BER DNA intermediates, we examined the influence of PARP1 and its autopoly(ADP-ribosyl)ation on DNA polymerase β (Pol β)-mediated long patch (LP) BER DNA synthesis that is accomplished through a cooperation between Pol β and apurinic/apyrimidinic endonuclease1 (APE1) or flap endonuclease 1 (FEN1) and gap-filling activity of Pol β. PARP1 upon interaction with nicked LP BER DNA intermediated, formed after gap-filling, was shown to suppress the subsequent steps in LP pathway. PARP1 interferes with APE1-dependent stimulation of DNA synthesis by Pol β via strand-displacement mechanism. PARP1 also represses Pol β/FEN1-mediated LP BER DNA synthesis via a 'gap translation' mechanism inhibiting FEN1 activity on the nicked DNA intermediate. Poly(ADP-ribosyl)ation of PARP1 abolishes its inhibitory influence on LP BER DNA synthesis catalyzed by Pol β both via APE1-mediated strand-displacement and FEN1-mediated 'gap translation' mechanism. Thus PARP1 may act as a negative regulator of Pol β activity in LP BER pathway and poly(ADP-ribosyl)ation of PARP1 seems to play a critical role in enablement of Pol β-mediated DNA synthesis in this process. In contrast, interaction of PARP1 with one nucleotide gapped DNA mimicking the intermediate of short patch (SP) BER slightly inhibits the gap-filling activity of Pol β and the overall efficiency of SP BER is practically unaffected by PARP1. Thus, PARP1 differentially influences DNA synthesis in SP- and

  14. Poly(ADP-Ribose) Polymerase 1 and Ste20-Like Kinase hKFC Act as Transcriptional Repressors for Gamma-2 Herpesvirus Lytic Replication

    OpenAIRE

    Gwack, Yousang; Nakamura, Hiroyuki; Lee, Sun Hwa; Souvlis, John; Yustein, Jason T.; Gygi, Steve; Kung, Hsing-Jien; Jung, Jae U.

    2003-01-01

    The replication and transcription activator (RTA) of gamma-2 herpesvirus is sufficient to drive the entire virus lytic cycle. Hence, the control of RTA activity should play an important role in the maintenance of viral latency. Here, we demonstrate that cellular poly(ADP-ribose) polymerase 1 (PARP-1) and Ste20-like kinase hKFC interact with the serine/threonine-rich region of gamma-2 herpesvirus RTA and that these interactions efficiently transfer poly(ADP-ribose) and phosphate units to RTA. ...

  15. Increased DNA damage in progression of COPD: a response by poly(ADP-ribose polymerase-1.

    Directory of Open Access Journals (Sweden)

    Ingrid Oit-Wiscombe

    Full Text Available Chronic oxidative stress (OS, a major mechanism of chronic obstructive pulmonary disease (COPD, may cause significant damage to DNA. Poly(ADP-ribose polymerase (PARP-1 is rapidly activated by OS-induced DNA lesions. However, the degree of DNA damage along with the evolution of COPD is unclear. In peripheral blood mononuclear cells of non-smoking individuals, non-obstructive smokers, patients with COPD of all stages and those with COPD exacerbation, we evaluated DNA damage, PARP activity and PARP-1 mRNA expression using Comet Assay IV, biotinylated-NAD incorporation assay and qRT-PCR, respectively and subjected results to ordinal logistic regression modelling. Adjusted for demographics, smoking-related parameters and lung function, novel comet parameters, tail length/cell length ratio and tail migration/cell length ratio, showed the greatest increase along the study groups corresponding to the evolution of COPD [odds ratio (OR 7.88, 95% CI 4.26-14.57; p<0.001 and OR 3.91, 95% CI 2.69-5.66; p<0.001, respectively]. Analogously, PARP activity increased significantly over the groups (OR = 1.01; 95%; p<0.001. An antioxidant tetrapeptide UPF17 significantly reduced the PARP-1 mRNA expression in COPD, compared to that in non-obstructive individuals (p = 0.040. Tail length/cell length and tail migration/cell length ratios provide novel progression-sensitive tools for assessment of DNA damage. However, it remains to be elucidated whether inhibition of an elevated PARP-1 activity has a safe enough potential to break the vicious cycle of the development and progression of COPD.

  16. TRPM2 channel opening in response to oxidative stress is dependent on activation of poly(ADP-ribose) polymerase

    OpenAIRE

    Fonfria, Elena; Marshall, Ian C B; Benham, Christopher D; Boyfield, Izzy; Brown, Jason D; Hill, Kerstin; Hughes, Jane P; Skaper, Stephen D.; McNulty, Shaun

    2004-01-01

    TRPM2 (melastatin-like transient receptor potential 2 channel) is a nonselective cation channel that is activated under conditions of oxidative stress leading to an increase in intracellular free Ca2+ concentration ([Ca2+]i) and cell death. We investigated the role of the DNA repair enzyme poly(ADP-ribose) polymerase (PARP) on hydrogen peroxide (H2O2)-mediated TRPM2 activation using a tetracycline-inducible TRPM2-expressing cell line.In whole-cell patch-clamp recordings, intracellular adenine...

  17. Analysis of knockout mutants reveals non-redundant functions of poly(ADP-ribose)polymerase isoforms in Arabidopsis.

    Science.gov (United States)

    Pham, Phuong Anh; Wahl, Vanessa; Tohge, Takayuki; de Souza, Laise Rosado; Zhang, Youjun; Do, Phuc Thi; Olas, Justyna J; Stitt, Mark; Araújo, Wagner L; Fernie, Alisdair R

    2015-11-01

    The enzyme poly(ADP-ribose)polymerase (PARP) has a dual function being involved both in the poly(ADP-ribosyl)ation and being a constituent of the NAD(+) salvage pathway. To date most studies, both in plant and non-plant systems, have focused on the signaling role of PARP in poly(ADP-ribosyl)ation rather than any role that can be ascribed to its metabolic function. In order to address this question we here used a combination of expression, transcript and protein localization studies of all three PARP isoforms of Arabidopsis alongside physiological analysis of the corresponding mutants. Our analyses indicated that whilst all isoforms of PARP were localized to the nucleus they are also present in non-nuclear locations with parp1 and parp3 also localised in the cytosol, and parp2 also present in the mitochondria. We next isolated and characterized insertional knockout mutants of all three isoforms confirming a complete knockout in the full length transcript levels of the target genes as well as a reduced total leaf NAD hydrolase activity in the two isoforms (PARP1, PARP2) that are highly expressed in leaves. Physiological evaluation of the mutant lines revealed that they displayed distinctive metabolic and root growth characteristics albeit unaltered leaf morphology under optimal growth conditions. We therefore conclude that the PARP isoforms play non-redundant non-nuclear metabolic roles and that their function is highly important in rapidly growing tissues such as the shoot apical meristem, roots and seeds. PMID:26428915

  18. Docking study and binding free energy calculation of poly (ADP-ribose) polymerase inhibitors.

    Science.gov (United States)

    Ohno, Kazuki; Mitsui, Takashi; Tanida, Yoshiaki; Matsuura, Azuma; Fujitani, Hideaki; Niimi, Tatsuya; Orita, Masaya

    2011-02-01

    Recently, the massively parallel computation of absolute binding free energy with a well-equilibrated system (MP-CAFEE) has been developed. The present study aimed to determine whether the MP-CAFEE method is useful for drug discovery research. In the drug discovery process, it is important for computational chemists to predict the binding affinity accurately without detailed structural information for protein/ligand complex. We investigated the absolute binding free energies for Poly (ADP-ribose) polymerase-1 (PARP-1)/inhibitor complexes, using the MP-CAFEE method. Although each docking model was used as an input structure, it was found that the absolute binding free energies calculated by MP-CAFEE are well consistent with the experimental ones. The accuracy of this method is much higher than that using molecular mechanics Poisson-Boltzmann/surface area (MM/PBSA). Although the simulation time is quite extensive, the reliable predictor of binding free energies would be a useful tool for drug discovery projects. PMID:20480380

  19. Acetylation of poly(ADP-ribose) polymerase-1 by p300/CREB-binding protein regulates coactivation of NF-kappaB-dependent transcription

    OpenAIRE

    Hassa, P O; et al

    2005-01-01

    Poly(ADP-ribose) polymerase-1 (PARP-1) and nuclear factor kappaB (NF-kappaB) have both been demonstrated to play a pathophysiological role in a number of inflammatory disorders. We recently presented evidence that PARP-1 can act as a promoter-specific coactivator of NF-kappaB in vivo independent of its enzymatic activity. PARP-1 directly interacts with p300 and both subunits of NF-kappaB (p65 and p50) and synergistically coactivates NF-kappaB-dependent transcription. Here we show that PARP-1 ...

  20. Cloning and expression of cDNA for human poly(ADP-ribose)polymerase

    International Nuclear Information System (INIS)

    cDNAs encoding poly(ADP-ribose) polymerase from a human hepatoma λgt11 cDNA library were isolated by immunological screening. One insert of 1.3 kilobases (kb) consistently hybridized on RNA gel blots to an mRNA species of 3.6-3.7 kb, which is consistent with the size of RNA necessary to code for the polymerase protein (116 kDa). This insert was subsequently used in both in vitro hybrid selection and hybrid-arrested translation studies. An mRNA species from HeLa cells of 3.6-3.7 kb was selected that was translated into a 116-kDa protein, which was selectively immunoprecipitated with anti-poly(ADP-ribose) polymerase. To confirm that the 1.3-kb insert from λgt11 encodes for poly(ADP-ribose) polymerase, the insert was used to screen a 3- to 4-kb subset of a transformed human fibroblast cDNA library in the Okayama-Berg vector. One of these vectors was tested in transient transfection experiments in COS cells. This cDNA insert contained the complete coding sequence for polymerase. Using pcD-p(ADPR)P as probe, it was observed that the level of poly(ADP-ribose) polymerase mRNA was elevated at 5 and 7 hr of S phase of the HeLa cell cycle, but was unaltered when artificial DNA strand breaks are introduced in HeLa cells by alkylating agents

  1. Poly(ADP-ribose) polymerase 1 inhibition protects human aortic endothelial cells against LPS-induced inflammation response

    Institute of Scientific and Technical Information of China (English)

    Xiaonu Peng; Wenjun Li; Wei Zhang

    2012-01-01

    Atherosclerosis is a chronic inflammatory disease.Tolllike receptor 4 (TLR4) is an important signaling receptor and plays a critical role in the inflammatory response.Poly(ADP-ribose) polymerase 1 (PARP1) is a nuclear enzyme that can regulate the expression of various inflammatory genes.In this study,we investigated the role and the underlying mechanisms of PARP1 on lipopolysaccharide (LPS)-induced inflammation in human aortic endothelial cells.Compared with the control,LPS stimulation increased the protein expression of TLR4 and PARP1.TLR4 inhibition reduced LPS-induced upregulation of inducible nitric oxide synthase (iNOS) and ICAM-1 as well as PARP1. Nuclear factor κB (NF-κB) inhibition decreased ICAM-1 and iNOS expression.Inhibition of PARP1 decreased protein expression of inflammatory cytokines induced by LPS stimulation,probably through preventing NF-KB nuclear translocation. Our study demonstrated that LPS increased ICAM-1 and iNOS expression via TLR4/PARP1/NF-KB pathway.PARP1 might be an indispensable factor in TLR4-mediated inflammation after LPS stimulation.PARP1 inhibition might shed light on the treatment of LPS-induced inflammatory cytokines expression during atherosclerosis.

  2. Current Status of Poly(ADP-ribose Polymerase Inhibitors as Novel Therapeutic Agents for Triple-Negative Breast Cancer

    Directory of Open Access Journals (Sweden)

    David J. Hiller

    2012-01-01

    Full Text Available Triple-negative breast cancer (TNBC is an aggressive type of breast cancer that is clinically defined as lacking estrogen and progesterone receptors, as well as being ERBB2 (HER-2 negative. Without specific therapeutic targets, TNBC carries a worse prognosis than other types of breast cancer in the absence of therapy. Research has now further differentiated breast cancer into subtypes based on genetic expression patterns. One of these subtypes, basal-like, frequently overlaps with the clinical picture of TNBC. Additionally, both TNBC and basal-like breast cancer link to BRCA mutations. Recent pharmaceutical advances have created a class of drugs, poly(ADP-ribose polymerase (PARP inhibitors, which are showing potential to effectively treat these patients. The aim of this paper is to summarize the basis behind PARP inhibitors and update the current status of their development in clinical trials for the treatment of TNBC.

  3. Poly(ADP-ribose) Polymerase 1 Is Indispensable for Transforming Growth Factor-β Induced Smad3 Activation in Vascular Smooth Muscle Cell

    OpenAIRE

    Dan Huang; Yan Wang; Lin Wang; Fengxiao Zhang; Shan Deng; Rui Wang; Yun Zhang; Kai Huang

    2011-01-01

    BACKGROUND: Transforming growth factor type-β (TGF-β)/Smad pathway plays an essential role in vascular fibrosis. Reactive oxygen species (ROS) generation also mediates TGF-β signaling-induced vascular fibrosis, suggesting that some sort of interaction exists between Smad and redox pathways. However, the underlying molecular mechanism is largely unknown. This study aims to investigate the influence of poly(ADP-ribose) polymerase 1 (PARP1), a downstream effector of ROS, on TGF-β signaling trans...

  4. 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...

  5. Structural analysis of poly(ADP-ribose)polymerase in higher and lower eukaryotes.

    Science.gov (United States)

    Scovassi, A I; Izzo, R; Franchi, E; Bertazzoni, U

    1986-08-15

    A phylogenetic survey for the poly(ADP-ribose)polymerase has been conducted by analyzing enzyme activity in various organisms and determining the structure of the catalytic peptides by renaturation of functional activities of the enzyme in situ after electrophoresis in denaturing conditions (activity gel). The enzyme is widely distributed in cells from all different classes of vertebrates, from arthropods, mollusks and plant cells but could not be detected in echinoderms, nematodes, platyhelminths, thallophytes (including yeast) and bacteria. The presence on activity gels of a catalytic peptide with Mr = 115,000-120,000 was demonstrated in vertebrates, arthropods and mollusks but no activity bands were recovered in many lower eukaryotes, in plant cells and bacteria. By using an immunological procedure that used an antiserum against homogeneous calf thymus poly(ADP-ribose) polymerase, common immunoreactive peptides were visualized in mammals, avians, reptiles, amphibians and fishes, while lacking in non-vertebrate organisms. Our results indicate that the structure of poly(ADP-ribose) polymerase is conserved down to the mollusks suggesting its important role for DNA metabolism of multicellular organisms. PMID:3091369

  6. Continuous inhibition of poly(ADP-ribose) polymerase does not reduce reperfusion injury in isolated rat heart.

    Science.gov (United States)

    Nishizawa, Kenya; Yanagida, Shigeki; Yamagishi, Tadashi; Takayama, Eiichi; Bessho, Motoaki; Kusuhara, Masatoshi; Adachi, Takeshi; Ohsuzu, Fumitaka

    2013-07-01

    Poly(ADP-ribose) polymerase (PARP), an enzyme that is important to the regulation of nuclear function, is activated by DNA strand breakage. In massive DNA damage, PARP is overactivated, exhausting nicotinamide adenine dinucleotide and leading to cell death. Recent studies have succeeded in reducing cellular damage in ischemia/reperfusion by inhibiting PARP. However, PARP plays an important part in the DNA repair system, and its inhibition may be hazardous in certain situations. We compared the short-time inhibition of PARP against continuous inhibition during ischemia/reperfusion using isolated rat hearts. The hearts were reperfused after 21 minutes of ischemia with a bolus injection of 3-aminobenzamide (3-AB) (10 mg/kg) followed by continuous 3-AB infusion (50 μM) for the whole reperfusion period or for the first 6 minutes or without 3-AB. At the end of reperfusion, contractile function, high-energy phosphate content, nicotinamide adenine dinucleotide content, and infarcted area were significantly preserved in the 3-AB 6-minute group. In the 3-AB continuous group, these advantages were not apparent. At the end of reperfusion, PARP cleavage had significantly proceeded in the 3-AB continuous group, indicating initiation of the apoptotic cascade. Thus, continuous PARP inhibition by 3-AB does not reduce reperfusion injury in the isolated rat heart, which may be because of acceleration of apoptosis. PMID:23846805

  7. Poly(ADP-ribose) polymerase activation induces high mobility group box 1 release from proximal tubular cells during cisplatin nephrotoxicity.

    Science.gov (United States)

    Kim, J

    2016-06-20

    Cisplatin is one of the most potent chemotherapy drugs against cancer, but its major side effect such as nephrotoxicity limits its use. Inhibition of poly(ADP-ribose) polymerase (PARP) protects against various renal diseases via gene transactivation and/or ADP-ribosylation. However, the role of PARP in necrotic cell death during cisplatin nephrotoxicity remains an open question. Here we demonstrated that pharmacological inhibition of PARP by postconditioning dose-dependently prevented tubular injury and renal dysfunction following cisplatin administration in mice. PARP inhibition by postconditioning also attenuated ATP depletion during cisplatin nephrotoxicity. Systemic release of high mobility group box 1 (HMGB1) protein in plasma induced by cisplatin administration was significantly diminished by PARP inhibition by postconditioning. In in vitro kidney proximal tubular cell lines, PARP inhibition by postconditioning also diminished HMGB1 release from cells. These data demonstrate that cisplatin-induced PARP1 activation contributes to HMGB1 release from kidney proximal tubular cells, resulting in the promotion of inflammation during cisplatin nephrotoxicity. PMID:26447520

  8. Targeting poly (ADP-ribose polymerase partially contributes to bufalin-induced cell death in multiple myeloma cells.

    Directory of Open Access Journals (Sweden)

    He Huang

    Full Text Available Despite recent pharmaceutical advancements in therapeutic drugs, multiple myeloma (MM remains an incurable disease. Recently, ploy(ADP-ribose polymerase 1 (PARP1 has been shown as a potentially promising target for MM therapy. A previous report suggested bufalin, a component of traditional Chinese medicine ("Chan Su", might target PARP1. However, this hypothesis has not been verified. We here showed that bufalin could inhibit PARP1 activity in vitro and reduce DNA-damage-induced poly(ADP-ribosylation in MM cells. Molecular docking analysis revealed that the active site of bufalin interaction is within the catalytic domain of PAPR1. Thus, PARP1 is a putative target of bufalin. Furthermore, we showed, for the first time that the proliferation of MM cell lines (NCI-H929, U266, RPMI8226 and MM.1S and primary CD138(+ MM cells could be inhibited by bufalin, mainly via apoptosis and G2-M phase cell cycle arrest. MM cell apoptosis was confirmed by apoptotic cell morphology, Annexin-V positive cells, and the caspase3 activation. We further evaluated the role of PARP1 in bufalin-induced apoptosis, discovering that PARP1 overexpression partially suppressed bufalin-induced cell death. Moreover, bufalin can act as chemosensitizer to enhance the cell growth-inhibitory effects of topotecan, camptothecin, etoposide and vorinostat in MM cells. Collectively, our data suggest that bufalin is a novel PARP1 inhibitor and a potentially promising therapeutic agent against MM alone or in combination with other drugs.

  9. Deficiency of terminal ADP-ribose protein glycohydrolase TARG1/C6orf130 in neurodegenerative disease

    OpenAIRE

    Sharifi, Reza; Morra, Rosa; Denise Appel, C; Tallis, Michael; Chioza, Barry; Jankevicius, Gytis; Simpson, Michael A.; Matic, Ivan; Ozkan, Ege; Golia, Barbara; Schellenberg, Matthew J.; Weston, Ria; Williams, Jason G.; Rossi, Marianna N.; Galehdari, Hamid

    2013-01-01

    Adenosine diphosphate (ADP)-ribosylation is a post-translational protein modification implicated in the regulation of a range of cellular processes. A family of proteins that catalyse ADP-ribosylation reactions are the poly(ADP-ribose) (PAR) polymerases (PARPs). PARPs covalently attach an ADP-ribose nucleotide to target proteins and some PARP family members can subsequently add additional ADP-ribose units to generate a PAR chain. The hydrolysis of PAR chains is catalysed by PAR glycohydrolase...

  10. Evolutionary history of the poly(ADP-ribose polymerase gene family in eukaryotes

    Directory of Open Access Journals (Sweden)

    Teotia Sachin

    2010-10-01

    Full Text Available Abstract Background The Poly(ADP-ribosepolymerase (PARP superfamily was originally identified as enzymes that catalyze the attachment of ADP-ribose subunits to target proteins using NAD+ as a substrate. The family is characterized by the catalytic site, termed the PARP signature. While these proteins can be found in a range of eukaryotes, they have been best studied in mammals. In these organisms, PARPs have key functions in DNA repair, genome integrity and epigenetic regulation. More recently it has been found that proteins within the PARP superfamily have altered catalytic sites, and have mono(ADP-ribose transferase (mART activity or are enzymatically inactive. These findings suggest that the PARP signature has a broader range of functions that initially predicted. In this study, we investigate the evolutionary history of PARP genes across the eukaryotes. Results We identified in silico 236 PARP proteins from 77 species across five of the six eukaryotic supergroups. We performed extensive phylogenetic analyses of the identified PARPs. They are found in all eukaryotic supergroups for which sequence is available, but some individual lineages within supergroups have independently lost these genes. The PARP superfamily can be subdivided into six clades. Two of these clades were likely found in the last common eukaryotic ancestor. In addition, we have identified PARPs in organisms in which they have not previously been described. Conclusions Three main conclusions can be drawn from our study. First, the broad distribution and pattern of representation of PARP genes indicates that the ancestor of all extant eukaryotes encoded proteins of this type. Second, the ancestral PARP proteins had different functions and activities. One of these proteins was similar to human PARP1 and likely functioned in DNA damage response. The second of the ancestral PARPs had already evolved differences in its catalytic domain that suggest that these proteins may not have

  11. Mass spectrometry-based functional proteomics of poly(ADP-ribose) polymerase-1.

    Science.gov (United States)

    Pic, Emilie; Gagné, Jean-Philippe; Poirier, Guy G

    2011-12-01

    PARP-1 is an abundant nuclear protein that plays an essential role in the regulation of many genome integrity and chromatin-based processes, such as DNA repair, replication or transcriptional regulation. PARP-1 modulates the function of chromatin and nuclear proteins through several poly(ADP-ribose) (pADPr)-dependent pathways. Aside from the clearly established role of PARP-1 in the maintenance of genome stability, PARP-1 also emerged as an important regulator that links chromatin functions with extranuclear compartments. pADPr signaling has notably been found to be responsible for PARP-1-mediated mitochondrial dysfunction and cell death. Defining the mechanisms that govern the intrinsic functions of PARP-1 is fundamental to the understanding of signaling networks regulated by pADPr. The emergence of mass spectrometry-based proteomics and its broad applications in the study of biological systems represents an outstanding opportunity to widen our knowledge of the functional spectrum of PARP-1. In this article, we summarize various PARP-1 targeted proteomics studies and proteome-wide analyses that shed light on its protein interaction partners, expression levels and post-translational modifications. PMID:22087659

  12. Genetic Cooperation between the Werner Syndrome Protein and Poly(ADP-Ribose) Polymerase-1 in Preventing Chromatid Breaks, Complex Chromosomal Rearrangements, and Cancer in Mice

    OpenAIRE

    Lebel, Michel; Lavoie, Josée; Gaudreault, Isabelle; Bronsard, Marc; Drouin, Régen

    2003-01-01

    Werner syndrome is a rare disorder characterized by the premature onset of a number of age-related diseases. The gene responsible for Werner syndrome encodes a DNA helicase/exonuclease protein. Participation in a replication complex is among the several functions postulated for the WRN protein. The poly(ADP-ribose) polymerase-1 (PARP-1) enzyme, which is known to bind to DNA strand breaks, is also associated with the DNA replication complex. To determine whether Wrn and PARP-1 enzymes act in c...

  13. Effect and Mechanism of Radiosensitization of Poly (ADP-Ribose Polymerase 
Inhibitor on Lewis Cells and Xenografts

    Directory of Open Access Journals (Sweden)

    Wei WANG

    2016-01-01

    Full Text Available Background and objective The DNA damage of the irradiated tumor cells is mainly single strand breaks (SSBs and double strand breaks (DSBs, in which the frequency of occurrence of SSBs is dozens of times than DSBs. However, most of the SSBs could be repaired by the Poly (ADP-Ribose Polymerase (PARP and other related factors. Recently listed drug-Olaparib (PARP1/PARP2/PARP3 inhibitor could target the repair pathways of single strand breaks, and recent clinical trials of PARP inhibitors combined with chemotherapy obtained encouraging results. The aim of this study is to investigate the effect and potential mechanism of radiosensitization of Poly (ADP-Ribose polymerase inhibitor-Olaparib on lewis cells and xenografts. Methods The inhibition concentration 10% inhibitory concentration (IC10 of Olaparib to Lewis cells was detected by methyl thiazolyltetrazolium (MTT assay. The radiosensitization effect of Olaparib on Lewis cells was determined by classical colony forming assay. Lewis xenografts models were established, and the mice were randomly divided into four groups: Control group, Olaparib group, Radiotherapy group (RT, 2 Gy×5 d, Olaparib combined with RT group. Xenograft volume was measured during the treatment. Flow cytometry was used to analyze the apoptosis rate of the Lewis cells in each group, and the apoptosis of xenograft tissues was observed by TUNEL stain. The ralative protein levels of γH2AX (associated with DNA strand breaks repair, Bax/Bcl-2, Caspase-3 (apoptosis-associated protein were detected by Western blot in vitro and in vivo. Results The IC10 value of Olaparib was 4.4 µmol/L. The radio-sensitivity enhancement ratio (SER of Olaparib combined with RT was 1.211 in vitro. Compared with RT (2 Gy×5 d alone, the combination of Olaparib with fractionated radiotherapy significantly increased the growth delay of Lewis xenografts (P<0.001. Flow cytometry and TUNEL analysis indicated that the apoptosis rate in the combination group was

  14. Expression of human poly (ADP-ribose) polymerase 1 in Saccharomyces cerevisiae: Effect on survival, homologous recombination and identification of genes involved in intracellular localization

    Energy Technology Data Exchange (ETDEWEB)

    La Ferla, Marco; Mercatanti, Alberto; Rocchi, Giulia; Lodovichi, Samuele; Cervelli, Tiziana; Pignata, Luca [Yeast Genetics and Genomics, Institute of Clinical Physiology, National Council of Research (CNR), via Moruzzi 1, 56122 Pisa (Italy); Caligo, Maria Adelaide [Section of Genetic Oncology, University Hospital and University of Pisa, via Roma 57, 56125 Pisa (Italy); Galli, Alvaro, E-mail: alvaro.galli@ifc.cnr.it [Yeast Genetics and Genomics, Institute of Clinical Physiology, National Council of Research (CNR), via Moruzzi 1, 56122 Pisa (Italy)

    2015-04-15

    Highlights: • The human poly (ADP-ribose) polymerase 1 (PARP-1) gene affects growth and UV-induced homologous recombination in yeast. • PARP-1 chemical inhibition impacts yeast growth and UV-induced recombination. • A genome-wide screen identifies 99 yeast genes that suppress the growth defect inferred by PARP-1. • Bioinformatics analysis identifies 41 human orthologues that may have a role in PARP-1 intracellular localization. • The findings suggest that PARP-1 nuclear localization may affect the response to PARP inhibitors in cancer therapy. - Abstract: The poly (ADP-ribose) polymerase 1 (PARP-1) actively participates in a series of functions within the cell that include: mitosis, intracellular signaling, cell cycle regulation, transcription and DNA damage repair. Therefore, inhibition of PARP1 has a great potential for use in cancer therapy. As resistance to PARP inhibitors is starting to be observed in patients, thus the function of PARP-1 needs to be studied in depth in order to find new therapeutic targets. To gain more information on the PARP-1 activity, we expressed PARP-1 in yeast and investigated its effect on cell growth and UV induced homologous recombination. To identify candidate genes affecting PARP-1 activity and cellular localization, we also developed a yeast genome wide genetic screen. We found that PARP-1 strongly inhibited yeast growth, but when yeast was exposed to the PARP-1 inhibitor 6(5-H) phenantridinone (PHE), it recovered from the growth suppression. Moreover, we showed that PARP-1 produced PAR products in yeast and we demonstrated that PARP-1 reduced UV-induced homologous recombination. By genome wide screening, we identified 99 mutants that suppressed PARP-1 growth inhibition. Orthologues of human genes were found for 41 of these yeast genes. We determined whether the PARP-1 protein level was altered in strains which are deleted for the transcription regulator GAL3, the histone H1 gene HHO1, the HUL4 gene, the

  15. Expression of human poly (ADP-ribose) polymerase 1 in Saccharomyces cerevisiae: Effect on survival, homologous recombination and identification of genes involved in intracellular localization

    International Nuclear Information System (INIS)

    Highlights: • The human poly (ADP-ribose) polymerase 1 (PARP-1) gene affects growth and UV-induced homologous recombination in yeast. • PARP-1 chemical inhibition impacts yeast growth and UV-induced recombination. • A genome-wide screen identifies 99 yeast genes that suppress the growth defect inferred by PARP-1. • Bioinformatics analysis identifies 41 human orthologues that may have a role in PARP-1 intracellular localization. • The findings suggest that PARP-1 nuclear localization may affect the response to PARP inhibitors in cancer therapy. - Abstract: The poly (ADP-ribose) polymerase 1 (PARP-1) actively participates in a series of functions within the cell that include: mitosis, intracellular signaling, cell cycle regulation, transcription and DNA damage repair. Therefore, inhibition of PARP1 has a great potential for use in cancer therapy. As resistance to PARP inhibitors is starting to be observed in patients, thus the function of PARP-1 needs to be studied in depth in order to find new therapeutic targets. To gain more information on the PARP-1 activity, we expressed PARP-1 in yeast and investigated its effect on cell growth and UV induced homologous recombination. To identify candidate genes affecting PARP-1 activity and cellular localization, we also developed a yeast genome wide genetic screen. We found that PARP-1 strongly inhibited yeast growth, but when yeast was exposed to the PARP-1 inhibitor 6(5-H) phenantridinone (PHE), it recovered from the growth suppression. Moreover, we showed that PARP-1 produced PAR products in yeast and we demonstrated that PARP-1 reduced UV-induced homologous recombination. By genome wide screening, we identified 99 mutants that suppressed PARP-1 growth inhibition. Orthologues of human genes were found for 41 of these yeast genes. We determined whether the PARP-1 protein level was altered in strains which are deleted for the transcription regulator GAL3, the histone H1 gene HHO1, the HUL4 gene, the

  16. Latonduine Analogs Restore F508del-Cystic Fibrosis Transmembrane Conductance Regulator Trafficking through the Modulation of Poly-ADP Ribose Polymerase 3 and Poly-ADP Ribose Polymerase 16 Activity.

    Science.gov (United States)

    Carlile, Graeme W; Robert, Renaud; Matthes, Elizabeth; Yang, Qi; Solari, Roberto; Hatley, Richard; Edge, Colin M; Hanrahan, John W; Andersen, Raymond; Thomas, David Y; Birault, Véronique

    2016-08-01

    Cystic fibrosis (CF) is a major lethal genetic disease caused by mutations in the CF transmembrane conductance regulator gene (CFTR). This encodes a chloride ion channel on the apical surface of epithelial cells. The most common mutation in CFTR (F508del-CFTR) generates a protein that is misfolded and retained in the endoplasmic reticulum. Identifying small molecules that correct this CFTR trafficking defect is a promising approach in CF therapy. However, to date only modest efficacy has been reported for correctors in clinical trials. We identified the marine sponge metabolite latonduine as a corrector. We have now developed a series of latonduine derivatives that are more potent F508del-CFTR correctors with one (MCG315 [2,3-dihydro-1H-2-benzazepin-1-one]) having 10-fold increased corrector activity and an EC50 of 72.25 nM. We show that the latonduine analogs inhibit poly-ADP ribose polymerase (PARP) isozymes 1, 3, and 16. Further our molecular modeling studies point to the latonduine analogs binding to the PARP nicotinamide-binding domain. We established the relationship between the ability of the latonduine analogs to inhibit PARP-16 and their ability to correct F508del-CFTR trafficking. We show that latonduine can inhibit both PARP-3 and -16 and that this is necessary for CFTR correction. We demonstrate that latonduine triggers correction by regulating the activity of the unfolded protein response activator inositol-requiring enzyme (IRE-1) via modulation of the level of its ribosylation by PARP-16. These results establish latonduines novel site of action as well as its proteostatic mechanism of action. PMID:27193581

  17. Targeting poly(ADP-ribose)polymerase1 in neurological diseases: A promising trove for new pharmacological interventions to enter clinical translation.

    Science.gov (United States)

    Sriram, Chandra Shekhar; Jangra, Ashok; Kasala, Eshvendar Reddy; Bodduluru, Lakshmi Narendra; Bezbaruah, Babul Kumar

    2014-10-01

    The highly conserved abundant nuclear protein poly(ADP-ribose)polymerase1 (PARP1) functions at the center of cellular stress response and is mainly implied in DNA damage repair mechanism. Apart from its involvement in DNA damage repair, it does sway multiple vital cellular processes such as cell death pathways, cell aging, insulator function, chromatin modification, transcription and mitotic apparatus function. Since brain is the principal organ vulnerable to oxidative stress and inflammatory responses, upon stress encounters robust DNA damage can occur and intense PARP1 activation may result that will lead to various CNS diseases. In the context of soaring interest towards PARP1 as a therapeutic target for newer pharmacological interventions, here in the present review, we are attempting to give a silhouette of the role of PARP1 in the neurological diseases and the potential of its inhibitors to enter clinical translation, along with its structural and functional aspects. PMID:25049175

  18. Poly(ADP-ribose) polymerase-1 and its cleavage products differentially modulate cellular protection through NF-kB-dependent signaling

    Science.gov (United States)

    Castri, Paola; Lee, Yang-ja; Ponzio, Todd; Maric, Dragan; Spatz, Maria; Bembry, Joliet; Hallenbeck, John

    2014-01-01

    Poly(ADP-ribose) polymerase-1 (PARP-1) and its cleavage products regulate cell viability and NF-kB activity when expressed in neurons. PARP-1 cleavage generates a 24kDa (PARP-124) and an 89kDa fragment (PARP-189). Compared to WT (PARP-1WT), the expression of an uncleavable PARP-1 (PARP-1UNCL) or of PARP-124 conferred protection from oxygen/glucose deprivation (OGD) or OGD/restoration of oxygen and glucose (ROG) damage in vitro, whereas expression of PARP-189 was cytotoxic. Viability experiments were performed in SH-SY5Y, a human neuroblastoma cell line, as well as in rat primary cortical neurons. Following OGD, the higher viability in the presence of PARP-1UNCL or PARP-124 was not accompanied with decreased formation of poly(ADP-riboses) or higher NAD levels. PARP-1 is a known cofactor for NF-kB, hence we investigated whether PARP-1 cleavage influences the inflammatory response. All PARP-1 constructs mimicked PARP-1WT in regards to induction of NF-kB translocation into the nucleus and its increased activation during ischemic challenge. However, expression of PARP-189 construct induced significantly higher NF-kB activity than PARP-1WT; and the same was true for NF-kB-dependent iNOS promoter binding activity. At a protein level, PARP-1UNCL and PARP-124 decreased iNOS (and lower levels of iNOS transcript) and COX-2, and increased Bcl-xL. The increased levels of NF-kB and iNOS transcriptional activities, seen with cytotoxic PARP-189, were accompanied by higher protein expression of COX-2 and iNOS (and higher levels of iNOS transcript) and lower protein expression of Bcl-xL. Taken together, these findings suggest that PARP-1 cleavage products may regulate cellular viability and inflammatory responses in opposing ways during in vitro models of “ischemia”. PMID:24333653

  19. Poly(ADP-ribose) polymerase inhibitor ABT-888 potentiates the cytotoxic activity of temozolomide in leukemia cells: influence of mismatch repair status and O6-methylguanine-DNA methyltransferase activity

    OpenAIRE

    Horton, Terzah M.; Jenkins, Gaye; Pati, Debananda; Zhang, Linna; Dolan, M. Eileen; Ribes-Zamora, Albert; Bertuch, Alison A.; Blaney, Susan M.; Delaney, Shannon L.; Hegde, Madhuri; Berg, Stacey L.

    2009-01-01

    The poly(ADP-ribose) polymerase (PARP) inhibitor ABT-888 potentiates the antitumor activity of temozolomide (TMZ). TMZ resistance results from increased O6-methylguanine-DNA methyltransferase (MGMT) activity and from mismatch repair (MMR) system mutations. We evaluated the relative importance of MGMT activity, MMR deficiency, nonhomologous end joining (NHEJ), and PARP activity in ABT-888 potentiation of TMZ. MMR-proficient and MMR-deficient leukemia cells with varying MGMT activity, as well a...

  20. Thrombomodulin Is Silenced in Malignant Mesothelioma by a Poly(ADP-ribose) Polymerase-1-mediated Epigenetic Mechanism

    Czech Academy of Sciences Publication Activity Database

    Nocchi, L.; Tomasetti, M.; Amati, M.; Neužil, Jiří; Santarelli, L.; Saccucci, F.

    2011-01-01

    Roč. 286, č. 22 (2011), s. 19478-19488. ISSN 0021-9258 R&D Projects: GA ČR(CZ) GA204/08/0811 Institutional research plan: CEZ:AV0Z50520701 Keywords : Thrombomodulin gene promoter * malignant mesothelioma * poly(ADP-ribose) polymerase-1 Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.773, year: 2011

  1. Differentiation-Associated Downregulation of Poly(ADP-Ribose Polymerase-1 Expression in Myoblasts Serves to Increase Their Resistance to Oxidative Stress.

    Directory of Open Access Journals (Sweden)

    Gábor Oláh

    Full Text Available Poly(ADP-ribose polymerase 1 (PARP-1, the major isoform of the poly (ADP-ribose polymerase family, is a constitutive nuclear and mitochondrial protein with well-recognized roles in various essential cellular functions such as DNA repair, signal transduction, apoptosis, as well as in a variety of pathophysiological conditions including sepsis, diabetes and cancer. Activation of PARP-1 in response to oxidative stress catalyzes the covalent attachment of the poly (ADP-ribose (PAR groups on itself and other acceptor proteins, utilizing NAD+ as a substrate. Overactivation of PARP-1 depletes intracellular NAD+ influencing mitochondrial electron transport, cellular ATP generation and, if persistent, can result in necrotic cell death. Due to their high metabolic activity, skeletal muscle cells are particularly exposed to constant oxidative stress insults. In this study, we investigated the role of PARP-1 in a well-defined model of murine skeletal muscle differentiation (C2C12 and compare the responses to oxidative stress of undifferentiated myoblasts and differentiated myotubes. We observed a marked reduction of PARP-1 expression as myoblasts differentiated into myotubes. This alteration correlated with an increased resistance to oxidative stress of the myotubes, as measured by MTT and LDH assays. Mitochondrial function, assessed by measuring mitochondrial membrane potential, was preserved under oxidative stress in myotubes compared to myoblasts. Moreover, basal respiration, ATP synthesis, and the maximal respiratory capacity of mitochondria were higher in myotubes than in myoblasts. Inhibition of the catalytic activity of PARP-1 by PJ34 (a phenanthridinone PARP inhibitor exerted greater protective effects in undifferentiated myoblasts than in differentiated myotubes. The above observations in C2C12 cells were also confirmed in a rat-derived skeletal muscle cell line (L6. Forced overexpression of PARP1 in C2C12 myotubes sensitized the cells to oxidant

  2. The human apurinic/apyrimidinic endonuclease-1 suppresses activation of poly(adp-ribose) polymerase-1 induced by DNA single strand breaks

    International Nuclear Information System (INIS)

    DNA single-strand breaks (SSB) activate poly (ADP-ribose) polymerase 1 (PARP1), which then polymerizes ADP-ribosyl groups on various nuclear proteins, consuming cellular energy. Although PARP1 has a role in repairing SSB, activation of PARP1 also causes necrosis and inflammation due to depletion of cellular energy. Here we show that the major mammalian apurinic/apyrimidinic (AP) endonuclease-1 (APE1), an essential DNA repair protein, binds to SSB and suppresses the activation of PARP1. APE1's high affinity for SSB requires Arg177, which is unique in mammalian APEs. PARP1's binding to the cleaved DNA was inhibited, and PARP1 activation was suppressed by the wild-type APE1, but not by the R177A mutant APE1 protein. Cells transiently transfected with the wild-type APE1 decreased the PARP1 activation after H2O2 treatment, while such suppression did not occur with the expression of the R177A APE1 mutant. These results suggest that APE1 suppresses the activation of PARP1 during the repair process of the DNA damage generated by oxidative stress, which may have an important implication for cells to avoid necrosis due to energy depletion

  3. Enhancement of the radiosensitivity of cultured lymphoma cells by 6(5H)-phenanthridinone, a novel poly (ADP-ribose) polymerase inhibitor

    International Nuclear Information System (INIS)

    Poly(ADP-ribose)polymerase (PARP, EC 2.4.2.30) is a chromatin-bound enzyme involved in a number of cellular processes linked to DNA metabolism such as proliferation, differentiation, DNA repair and apoptosis. Therefore, its inhibition, by preventing DNA repair to occur, has been proposed to potentiate radiotherapy or chemotherapy of tumors. However, the inhibitors used so far, mostly benzamide derivatives, gave un-conclusive results due to their weak inhibition potency and to their poor specificity. Recently, a new generation of PARP inhibitors has emerged, much more specific and active. We previously characterized one of them, namely 6(5H)-phenanthridinone (Phen), and showed its ability to potentiate the effects of anticancer drugs upon cultured tumor cells. These results prompted us to investigate whether Phen could also potentiate the effects of γ-radiations. (authors)

  4. Activation of Reg gene, a gene for insulin-producing β-cell regeneration: Poly(ADP-ribose) polymerase binds Reg promoter and regulates the transcription by autopoly(ADP-ribosyl)ation

    OpenAIRE

    Akiyama, Takako; Takasawa, Shin; Nata, Koji; Kobayashi, Seiichi; Abe, Michiaki; Shervani, Nausheen J.; Ikeda, Takayuki; NAKAGAWA, Kei; Unno, Michiaki; Matsuno, Seiki; Okamoto, Hiroshi

    2000-01-01

    The regeneration of pancreatic islet β cells is important for the prevention and cure of diabetes mellitus. We have demonstrated that the administration of poly(ADP-ribose) synthetase/polymerase (PARP) inhibitors such as nicotinamide to 90% depancreatized rats induces islet regeneration. From the regenerating islet-derived cDNA library, we have isolated Reg (regenerating gene) and demonstrated that Reg protein induces β-cell replication via the Reg receptor and ame...

  5. The ADP-ribose polymerase Tankyrase regulates adult intestinal stem cell proliferation during homeostasis in Drosophila.

    Science.gov (United States)

    Wang, Zhenghan; Tian, Ai; Benchabane, Hassina; Tacchelly-Benites, Ofelia; Yang, Eungi; Nojima, Hisashi; Ahmed, Yashi

    2016-05-15

    Wnt/β-catenin signaling controls intestinal stem cell (ISC) proliferation, and is aberrantly activated in colorectal cancer. Inhibitors of the ADP-ribose polymerase Tankyrase (Tnks) have become lead therapeutic candidates for Wnt-driven cancers, following the recent discovery that Tnks targets Axin, a negative regulator of Wnt signaling, for proteolysis. Initial reports indicated that Tnks is important for Wnt pathway activation in cultured human cell lines. However, the requirement for Tnks in physiological settings has been less clear, as subsequent studies in mice, fish and flies suggested that Tnks was either entirely dispensable for Wnt-dependent processes in vivo, or alternatively, had tissue-specific roles. Here, using null alleles, we demonstrate that the regulation of Axin by the highly conserved Drosophila Tnks homolog is essential for the control of ISC proliferation. Furthermore, in the adult intestine, where activity of the Wingless pathway is graded and peaks at each compartmental boundary, Tnks is dispensable for signaling in regions where pathway activity is high, but essential where pathway activity is relatively low. Finally, as observed previously for Wingless pathway components, Tnks activity in absorptive enterocytes controls the proliferation of neighboring ISCs non-autonomously by regulating JAK/STAT signaling. These findings reveal the requirement for Tnks in the control of ISC proliferation and suggest an essential role in the amplification of Wnt signaling, with relevance for development, homeostasis and cancer. PMID:27190037

  6. 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.

  7. 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)

    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

  8. Influence of inhibitors of poly(ADP-ribose) polymerase on DNA repair, chromosomal alterations, and mutations

    Energy Technology Data Exchange (ETDEWEB)

    Natarajan, A.T.; van Zeeland, A.A.; Zwanenburg, T.S.

    1983-01-01

    The influence of inhibitors of poly(ADP-ribose) polymerase such as 3-aminobenzamide (3AB) and benzamide (B) on the spontaneously occurring as well as mutagen induced chromosomal aberrations, sister chromatid exchanges (SCEs) and point mutations has been studied. In addition, the influence of 3AB on DNA repair was measured following treatment with physical and chemical mutagens. Post treatment of X-irradiated mammalian cells with 3AB increases the frequencies of induced chromosomal aberrations by a factor of 2 to 3. 3AB, when present in the medium containing bromodeoxyuridine(BrdUrd) during two cell cycles, increases the frequencies of SCEs in Chinese hamster ovary cells (CHO) in a concentration dependent manner leading to about a 10-fold increase at 10 mM concentration. The extent of increase in the frequencies of SCEs due to 1 mM 3AB in several human cell lines has been studied, including those derived from patients suffering from genetic diseases such as ataxia telangiectasia (A-T), Fanconi's anemia (FA), and Huntington's chorea. None of these syndromes showed any increased response when compared to normal cells. 3AB, however, increased the frequencies of spontaneously occurring chromosomal aberrations in A-T and FA cells. 3AB does not influence the frequencies of SCEs induced by UV or mitomycin C (MMC) in CHO cells. However, it increases the frequencies of SCEs induced by ethyl methanesulfonate (EMS) and methyl methanesulfonate (MMS). Under the conditions in which 3AB increases the frequencies of spontaneously occurring as well as induced SCEs, it does not increase the frequencies of point mutations in hypoxanthine-guanine phosphoribosyltransferase (HGPRT) locus. 3AB does not influence the amount of repair replication following dimethylsulphate (DMS) treatment of human fibroblasts, or UV irradiated human lymphocytes.

  9. Induction of Poly(ADP-ribose) Polymerase in Mouse Bone Marrow Stromal Cells Exposed to 900 MHz Radiofrequency Fields: Preliminary Observations

    Science.gov (United States)

    He, Qina; Sun, Yulong; Zong, Lin; Tong, Jian; Cao, Yi

    2016-01-01

    Background. Several investigators have reported increased levels of poly(ADP-ribose) polymerase-1 (PARP-1), a nuclear enzyme which plays an important role in the repair of damaged DNA, in cells exposed to extremely low dose ionizing radiation which does not cause measurable DNA damage. Objective. To examine whether exposure of the cells to nonionizing radiofrequency fields (RF) is capable of increasing messenger RNA of PARP-1 and its protein levels in mouse bone marrow stromal cells (BMSCs). Methods. BMSCs were exposed to 900 MHz RF at 120 μW/cm2 power intensity for 3 hours/day for 5 days. PARP-1 mRNA and its protein levels were examined at 0, 0.5, 1, 2, 4, 6, 8, and 10 hours after exposure using RT-PCR and Western blot analyses. Sham-exposed (SH) cells and those exposed to ionizing radiation were used as unexposed and positive control cells. Results. BMSCs exposed to RF showed significantly increased expression of PARP-1 mRNA and its protein levels after exposure to RF while such changes were not observed in SH-exposed cells. Conclusion. Nonionizing RF exposure is capable of inducing PARP-1.

  10. Effects of 3-aminobenzamide on poly(ADP-ribose)polymerase expression,apoptosis and cell cycle progression of HeLa cells after X-ray irradiation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The aim of this paper is to study the changes of apoptosis and cell cycle progression in HeLa cells after the poly(ADP-ribose)polymerase(PARP)was inhibited by its inhibitor 3-aminobenzamide(3-AB)and the mechanisms of PARP action on HeLa cells damaged by irradiation.Flow cytometry(FCM)was used to examine the PARP expression and the percentage of apoptotic cells and cell cycle progression.The percentage of HeLa cells with positive expression of PARP protein 2,4,8 and 12 h after administrated with 3-AB was significantly lower than that of the control(P<0.01).The percentages of apoptotic cells in the 3-AB plus irradiation group at the time points of 2,8,12 and 24 h after 2 Gy irradiation were higher than that in the irradiation group(P<0.01 or P<0.05)and the percentage of G2 cells decreased significantly(P<0.01 or P<0.05).It indicates that 3-AB can rapidly inhibit PARP expression of HeLa cells,promote cell apoptosis and block G2 arrest induced by irradiation.

  11. Metabolic consequences of DNA damage: The role of poly (ADP-ribose) polymerase as mediator of the suicide response

    International Nuclear Information System (INIS)

    Recent studies show that DNA damage can produce rapid alterations in steady state levels of deoxynucleoside triphosphate pools, for example, MNNG or uv-irradiation cause rapid increases in dATP and dTTP pools without significant changes in dGTP or dCTP pools. In vitro, studies with purified eukaryotic DNA polymerases show that the frequency of nucleotide misincorporation was affected by alterations in relative concentrations of the deoxynucleoside triphosphates. Thus the alterations in dNTP pool sizes that occur consequent to DNA damage may contribute to an increased mutagenic frequency. Poly(ADP-ribose) polymerase mediated suicide mechanism may participate in the toxicity of adenosine deaminase deficiency and severe combined immune deficiency disease in humans. Individuals with this disease suffer severe lymphopenia due to the toxic effects of deoxyadenosine. The lymphocytotoxic effect of adenosine deaminase deficiency can be simulated in lymphocyte cell lines from normal individuals by incubating them with the adenosine deaminase inhibitor, deoxycoformycin. Incubation of such leukocytes with deoxycoformycin and deoxyadenosine results in the gradual accumulation of DNA strand breaks and the depletion of NAD+ leading to cell death over a period of several days. This depletion of NAD and loss of cell viability were effectively blocked by nicotinamide or 3-amino benzamide. Thus, persistent activation of poly(ADP-ribose) polymerase by unrepaired or recurrent DNA strand breaks may activate the suicide mechanism of cell death. This study provides a basis for the interesting suggestion that treatment with nicotinamide could block the persistent activity of poly(ADP-ribose) polymerase and may help preserve lymphocyte function in patients with adenosine deaminase deficiency. 16 refs., 3 figs., 2 tabs

  12. Poly(ADP-Ribose) Polymerase-1 and DNA-Dependent Protein Kinase Have Equivalent Roles in Double Strand Break Repair Following Ionizing Radiation

    International Nuclear Information System (INIS)

    Purpose: Radiation-induced DNA double strand breaks (DSBs) are predominantly repaired by nonhomologous end joining (NHEJ), involving DNA-dependent protein kinase (DNA-PK). Poly(ADP-ribose) polymerase-1 (PARP-1), well characterized for its role in single strand break repair, may also facilitate DSB repair. We investigated the activation of these enzymes by differing DNA ends and their interaction in the cellular response to ionizing radiation (IR). Methods and Materials: The effect of PARP and DNA-PK inhibitors (KU-0058684 and NU7441) on repair of IR-induced DSBs was investigated in DNA-PK and PARP-1 proficient and deficient cells by measuring γH2AX foci and neutral comets. Complementary in vitro enzyme kinetics assays demonstrated the affinities of DNA-PK and PARP-1 for DSBs with varying DNA termini. Results: DNA-PK and PARP-1 both promoted the fast phase of resolution of IR-induced DSBs in cells. Inactivation of both enzymes was not additive, suggesting that PARP-1 and DNA-PK cooperate within the same pathway to promote DSB repair. The affinities of the two enzymes for oligonucleotides with blunt, 3' GGG or 5' GGG overhanging termini were similar and overlapping (Kdapp = 2.6-6.4nM for DNA-PK; 1.7-4.5nM for PARP-1). DNA-PK showed a slightly greater affinity for overhanging DNA and was significantly more efficient when activated by a 5' GGG overhang. PARP-1 had a preference for blunt-ended DNA and required a separate factor for efficient stimulation by a 5' GGG overhang. Conclusion: DNA-PK and PARP-1 are both required in a pathway facilitating the fast phase of DNA DSB repair.

  13. Pharmacological inhibition of poly(ADP-ribose) polymerase-1 modulates resistance of human glioblastoma stem cells to temozolomide

    International Nuclear Information System (INIS)

    Chemoresistance of glioblastoma multiforme (GBM) has been attributed to the presence within the tumor of cancer stem cells (GSCs). The standard therapy for GBM consists of surgery followed by radiotherapy and the chemotherapeutic agent temozolomide (TMZ). However, TMZ efficacy is limited by O6-methylguanine-DNA-methyltransferase (MGMT) and Mismatch Repair (MMR) functions. Strategies to counteract TMZ resistance include its combination with poly(ADP-ribose) polymerase inhibitors (PARPi), which hamper the repair of N-methylpurines. PARPi are also investigated as monotherapy for tumors with deficiency of homologous recombination (HR). We have investigated whether PARPi may restore GSC sensitivity to TMZ or may be effective as monotherapy. Ten human GSC lines were assayed for MMR proteins, MGMT and PARP-1 expression/activity, MGMT promoter methylation and sensitivity to TMZ or PARPi, alone and in combination. Since PTEN defects are frequently detected in GBM and may cause HR dysfunction, PTEN expression was also analyzed. The statistical analysis of the differences in drug sensitivity among the cell lines was performed using the ANOVA and Bonferroni’s post-test or the non-parametric Kruskal-Wallis analysis and Dunn’s post-test for multiple comparisons. Synergism between TMZ and PARPi was analyzed by the median-effect method of Chou and Talalay. Correlation analyses were done using the Spearman’s rank test. All GSCs were MMR-proficient and resistance to TMZ was mainly associated with high MGMT activity or low proliferation rate. MGMT promoter hypermethylation of GSCs correlated both with low MGMT activity/expression (Spearman’s test, P = 0.004 and P = 0.01) and with longer overall survival of GBM patients (P = 0.02). Sensitivity of each GSC line to PARPi as single agent did not correlate with PARP-1 or PTEN expression. Notably, PARPi and TMZ combination exerted synergistic antitumor effects in eight out of ten GSC lines and the TMZ dose reduction achieved

  14. Influence of inhibitors of poly(ADP-ribose) polymerase on DNA repair, chromosomal alterations, and mutations.

    Science.gov (United States)

    Natarajan, A T; van Zeeland, A A; Zwanenburg, T S

    1983-01-01

    The influence of inhibitors of poly(ADP-ribose) polymerase such as 3-aminobenzamide (3AB) and benzamide (B) on the spontaneously occurring as well as mutagen induced chromosomal aberrations, sister chromatid exchanges (SCEs) and point mutations has been studied. In addition, we have measured the influence of 3AB on DNA repair following treatment with physical and chemical mutagens. Post treatment of X-irradiated mammalian cells with 3AB increases the frequencies of induced chromosomal aberrations by a factor of 2 to 3. Both acentric fragments and exchanges increase indicating that the presence of 3AB slows down the repair of DNA strand breaks (probably DNA double strand breaks), thus making breaks available for interaction with each other to give rise to exchanges. 3AB, when present in the medium containing bromodeoxyuridine(BrdUrd) during two cell cycles, increases the frequencies of SCEs in Chinese hamster ovary cells (CHO) in a concentration dependent manner leading to about a 10-fold increase at 10 mM concentration. Most 3AB induced SCEs occur during the second cell cycle, in which DNA containing bromouridine (BU) is used as template for replication. BU containing DNA appears to be prone to errors during replication. The extent of increase in the frequencies of SCEs by 3AB is correlated with the amount of BU incorporated in the DNA of the cells. The frequencies of spontaneously occurring DNA single strand breaks in cells grown in BrdUrd containing medium are higher than in the cells grown in normal medium and this increase depends on the amount of BU incorporated in the DNA of these cells. We have studied the extent of increase in the frequencies of SCEs due to 1 mM 3AB in several human cell lines, including those derived from patients suffering from genetic diseases such as ataxia telangiectasia (A-T), Fanconi's anemia (FA), and Huntington's chorea. None of these syndromes showed any increased response when compared to normal cells. 3AB, however, increased the

  15. Poly(ADP-ribose polymerase 1 is indispensable for transforming growth factor-β Induced Smad3 activation in vascular smooth muscle cell.

    Directory of Open Access Journals (Sweden)

    Dan Huang

    Full Text Available BACKGROUND: Transforming growth factor type-β (TGF-β/Smad pathway plays an essential role in vascular fibrosis. Reactive oxygen species (ROS generation also mediates TGF-β signaling-induced vascular fibrosis, suggesting that some sort of interaction exists between Smad and redox pathways. However, the underlying molecular mechanism is largely unknown. This study aims to investigate the influence of poly(ADP-ribose polymerase 1 (PARP1, a downstream effector of ROS, on TGF-β signaling transduction through Smad3 pathway in rat vascular smooth muscle cells (VSMCs. METHODS AND RESULTS: TGF-β1 treatment promoted PARP1 activation through induction of ROS generation in rat VSMCs. TGF-β1-induced phosphorylation and nuclear accumulation of Smad3 was prevented by treatment of cells with PARP inhibitor, 3-aminobenzamide (3AB or N-(6-oxo-5,6-dihydrophenanthridin-2-yl-2-(N,N-dimethylaminoacetami (PJ34, or PARP1 siRNA. TGF-β1 treatment promoted poly(ADP-ribosylation of Smad3 via activation of PARP1 in the nucleus. Poly(ADP-ribosylation enhanced Smad-Smad binding element (SBE complex formation in nuclear extracts and increased DNA binding activity of Smad3. Pretreatment with 3AB, PJ34, or PARP1 siRNA prevented TGF-β1-induced Smad3 transactivation and expression of Smad3 target genes, including collagen Iα1, collagen IIIα1 and tissue inhibitor of metalloproteinase 1, in rat VSMCs. CONCLUSIONS: PARP1 is indispensable for TGF-β1 induced Smad3 activation in rat VSMCs. Targeting PARP1 may be a promising therapeutic approach against vascular diseases induced by dysregulation of TGF-β/Smad3 pathway.

  16. Effect of inhibitors of poly(ADP-ribose)polymerase on the radiation response of HeLa S3 cells

    International Nuclear Information System (INIS)

    The purpose of this study was to investigate possible involvement of poly(ADP-ribosyl)ation reactions in X-ray-induced cell killing, repair of potentially lethal damage (PLD), and formation and repair of radiation-induced DNA damage. As tools we used the inhibitors of poly(ADP-ribose)polymerase, 3-aminobenzamide (3AB), and 4-aminobenzamide (4AB). Both drugs inhibited PLD repair equally well but did not increase radiation-induced cell killing when cells were plated immediately after irradiation. 3AB affected repair of radiation-induced DNA damage, while 4AB had no effect. When 3AB was combined with aphidicolin (APC), it was found that the amount of DNA damage increased during the postirradiation incubation period. This means that the presence of 3AB stimulates the formation of DNA damage after X-irradiation. It is concluded that 3AB and 4AB sensitize HeLaS3 cells for radiation-induced cell killing by inhibiting repair of PLD. Because of the different effects of both inhibitors on repair of PLD and repair of radiation-induced DNA damage (a process known to be affected by inhibition of poly(ADP-ribosyl)ation), it is concluded that the observed inhibition of PLD repair is not caused by inhibition of poly(ADP-ribose)polymerase, and that the inhibitors affect repair of PLD and repair of DNA damage through independent mechanisms

  17. Effect of inhibitors of poly(ADP-ribose)polymerase on the radiation response of HeLa S3 cells

    Energy Technology Data Exchange (ETDEWEB)

    Burgman, P.; Konings, A.W. (State Univ. Groningen (Netherlands))

    1989-08-01

    The purpose of this study was to investigate possible involvement of poly(ADP-ribosyl)ation reactions in X-ray-induced cell killing, repair of potentially lethal damage (PLD), and formation and repair of radiation-induced DNA damage. As tools we used the inhibitors of poly(ADP-ribose)polymerase, 3-aminobenzamide (3AB), and 4-aminobenzamide (4AB). Both drugs inhibited PLD repair equally well but did not increase radiation-induced cell killing when cells were plated immediately after irradiation. 3AB affected repair of radiation-induced DNA damage, while 4AB had no effect. When 3AB was combined with aphidicolin (APC), it was found that the amount of DNA damage increased during the postirradiation incubation period. This means that the presence of 3AB stimulates the formation of DNA damage after X-irradiation. It is concluded that 3AB and 4AB sensitize HeLaS3 cells for radiation-induced cell killing by inhibiting repair of PLD. Because of the different effects of both inhibitors on repair of PLD and repair of radiation-induced DNA damage (a process known to be affected by inhibition of poly(ADP-ribosyl)ation), it is concluded that the observed inhibition of PLD repair is not caused by inhibition of poly(ADP-ribose)polymerase, and that the inhibitors affect repair of PLD and repair of DNA damage through independent mechanisms.

  18. Effect of inhibitors of poly(ADP-ribose) polymerase on the heat response of HeLa S3 cells.

    Science.gov (United States)

    Burgman, P; Konings, A W

    1988-12-01

    The purpose of this study was to investigate a possible involvement of poly(ADP-ribosyl)ation reactions in hyperthermic cell killing and hyperthermic DNA strand-break induction and repair in HeLa S3 cells. The inhibitors of poly(ADP-ribose) polymerase, 3-aminobenzamide (3AB) and 4-aminobenzamide (4AB), were used as tools in this study. Both inhibitors could sensitize the cells for hyperthermic cell killing equally well, although 3AB is known to be a more effective enzyme inhibitor. The heat sensitization at the level of cell killing could be reversed when the compounds were still present during a 4-h postincubation at 37 degrees C. More heat-induced DNA strand breaks were formed in the presence of 3AB and 4AB. Repair of strand breaks was inhibited during the postincubation at 37 degrees C. Thus the effect of 3AB and 4AB on DNA strand-break repair was different from the cited effect on cell survival. It is concluded that the sensitizing effect of 3AB and 4AB on hyperthermic cell killing is not caused by inhibition of poly(ADP-ribose) polymerase and is also not related to repair of DNA strand breaks. PMID:3144718

  19. Effect of inhibitors of poly(ADP-ribose)polymerase on the radiation response of HeLa S3 cells.

    Science.gov (United States)

    Burgman, P; Konings, A W

    1989-08-01

    The purpose of this study was to investigate possible involvement of poly(ADP-ribosyl)ation reactions in X-ray-induced cell killing, repair of potentially lethal damage (PLD), and formation and repair of radiation-induced DNA damage. As tools we used the inhibitors of poly(ADP-ribose)polymerase, 3-aminobenzamide (3AB), and 4-aminobenzamide (4AB). Both drugs inhibited PLD repair equally well but did not increase radiation-induced cell killing when cells were plated immediately after irradiation. 3AB affected repair of radiation-induced DNA damage, while 4AB had no effect. When 3AB was combined with aphidicolin (APC), it was found that the amount of DNA damage increased during the postirradiation incubation period. This means that the presence of 3AB stimulates the formation of DNA damage after X-irradiation. It is concluded that 3AB and 4AB sensitize HeLaS3 cells for radiation-induced cell killing by inhibiting repair of PLD. Because of the different effects of both inhibitors on repair of PLD and repair of radiation-induced DNA damage (a process known to be affected by inhibition of poly(ADP-ribosyl)ation), it is concluded that the observed inhibition of PLD repair is not caused by inhibition of poly(ADP-ribose)polymerase, and that the inhibitors affect repair of PLD and repair of DNA damage through independent mechanisms. PMID:2502817

  20. Reduced proficiency in homologous recombination underlies the high sensitivity of embryonal carcinoma testicular germ cell tumors to Cisplatin and poly (adp-ribose polymerase inhibition.

    Directory of Open Access Journals (Sweden)

    Francesca Cavallo

    Full Text Available Testicular Germ Cell Tumors (TGCT and patient-derived cell lines are extremely sensitive to cisplatin and other interstrand cross-link (ICL inducing agents. Nevertheless, a subset of TGCTs are either innately resistant or acquire resistance to cisplatin during treatment. Understanding the mechanisms underlying TGCT sensitivity/resistance to cisplatin as well as the identification of novel strategies to target cisplatin-resistant TGCTs have major clinical implications. Herein, we have examined the proficiency of five embryonal carcinoma (EC cell lines to repair cisplatin-induced ICLs. Using γH2AX staining as a marker of double strand break formation, we found that EC cell lines were either incapable of or had a reduced ability to repair ICL-induced damage. The defect correlated with reduced Homologous Recombination (HR repair, as demonstrated by the reduction of RAD51 foci formation and by direct evaluation of HR efficiency using a GFP-reporter substrate. HR-defective tumors cells are known to be sensitive to the treatment with poly(ADP-ribose polymerase (PARP inhibitor. In line with this observation, we found that EC cell lines were also sensitive to PARP inhibitor monotherapy. The magnitude of sensitivity correlated with HR-repair reduced proficiency and with the expression levels and activity of PARP1 protein. In addition, we found that PARP inhibition strongly enhanced the response of the most resistant EC cells to cisplatin, by reducing their ability to overcome the damage. These results point to a reduced proficiency of HR repair as a source of sensitivity of ECs to ICL-inducing agents and PARP inhibitor monotherapy, and suggest that pharmacological inhibition of PARP can be exploited to target the stem cell component of the TGCTs (namely ECs and to enhance the sensitivity of cisplatin-resistant TGCTs to standard treatments.

  1. Selective down-regulation of nuclear poly(ADP-ribose glycohydrolase.

    Directory of Open Access Journals (Sweden)

    David M Burns

    Full Text Available BACKGROUND: The formation of ADP-ribose polymers on target proteins by poly(ADP-ribose polymerases serves a variety of cell signaling functions. In addition, extensive activation of poly(ADP-ribose polymerase-1 (PARP-1 is a dominant cause of cell death in ischemia-reperfusion, trauma, and other conditions. Poly(ADP-ribose glycohydrolase (PARG degrades the ADP-ribose polymers formed on acceptor proteins by PARP-1 and other PARP family members. PARG exists as multiple isoforms with differing subcellular localizations, but the functional significance of these isoforms is uncertain. METHODS / PRINCIPAL FINDINGS: Primary mouse astrocytes were treated with an antisense phosphorodiamidate morpholino oligonucleotide (PMO targeted to exon 1 of full-length PARG to suppress expression of this nuclear-specific PARG isoform. The antisense-treated cells showed down-regulation of both nuclear PARG immunoreactivity and nuclear PARG enzymatic activity, without significant alteration in cytoplasmic PARG activity. When treated with the genotoxic agent MNNG to induced PARP-1 activation, the antisense-treated cells showed a delayed rate of nuclear PAR degradation, reduced nuclear condensation, and reduced cell death. CONCLUSIONS/SIGNIFICANCE: These results support a preferentially nuclear localization for full-length PARG, and suggest a key role for this isoform in the PARP-1 cell death pathway.

  2. Fragmentation radioinduite de l'ADN et réparation étudiée par immunomarquage anti poly(ADP-ribose)polymérase (PARP) dans les cellules de hamster chinois (CHO)

    Science.gov (United States)

    Bidon, N.; Varlet, P.; Noël, G.; Demurcia, G.; Salamero, J.; Averbeck, D.

    1998-04-01

    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 (137Cs) at a high (12.8 Gy/min) or medium dose rate (5 Gy/min), and immunolabelling against (ADP-ribose) polymers immediatly 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 disappearence after 3 hours at 37 °C. The presence of PARP activity appears to reflect γ-rays induced DNA fragmentation. Le poly(ADP-ribose)polymérase est une enzyme nucléaire ubiquitaire capable de se fixer sur les cassures de l'ADN. Sur une lignée sauvage de cellules d'ovaire de hamster chinois (CHO-K1) cultivée sur lame et irradiée aux rayons γ à haut débit de dose (HD) 12,8 Gy/min ou à moyen débit de dose (MD) 5 Gy/min, nous avons réalisé un immunomarquage anti-polymères d'ADP-ribose immédiatement après l'irradiation γ ou après trois heures d'incubation à 37 °C. La quantification et la localisation des lésions radioinduites ont été réalisées par microscopie confocale. Les résultats montrent une relation dose-effet et un effet de débit de dose, ainsi qu'une disparition du signal après 3 heures à 37 °C. La présence de la PARP semble donc bien refléter la fragmentation radioinduite de l'ADN.

  3. 多聚ADP核糖聚合酶-1及其依赖性细胞死亡在神经系统疾病中的研究进展%The advance of poly ADP-ribose polymerase-1 and poly ADP-ribose polymerase-1-dependent cell death in nervous system diseases

    Institute of Scientific and Technical Information of China (English)

    刘宏伟; 华宁; 于泳浩

    2013-01-01

    Background Poly ADP-ribose polymerase-1 (PARP-1),a main DNA repair enzyme,mediates PARP-1-dependent cell death under stress while it maintains genome stability under physiologic status.Objective To review the effect of PARP-1 and PARthanatos in the pathogenesis of nervous system diseases and discuss the therapeutic value of PARP-1 blocking.Content Persistent DNA stress induces hyper-activation of PARP-1 and translocation of apoptosis induced factor (AIF) from mitochondria into nucleus,followed with chromosome condensation,which is characteristics of PARthanatos.Ischemic/reperfusion in strokes produces robust reactive oxygen species,glutamate and other substances trigger release of superoxide and reactive oxygen species,mediate neurodegenerative diseases.Sustained activation of PARP-1 and PARthanatos through oxidative stress is involved in these diseases and its inhibition had significant alleviation of neuron death.Trend Hyper activation of PARP-1 triggers pathologic changes in stroke and neurodegenerative diseases.PARP-1 blockade may be a new strategy to promote neuron survival in stroke and neurodegenerative diseases.%背景 多聚ADP核糖聚合酶-1(poly ADP-ribose polymerase-1,PARP-1)作为一种DNA修复酶,具有维持基因组稳定的生理作用,应激条件下介导细胞程序性死亡,即PARP-1依赖性细胞死亡(PARP-1-dependent cell death,PARthanatos).目的 研究PARP-1及其介导的细胞死亡在脑卒中和神经退行性疾病等神经系统疾病中作用,探讨PARP-1阻断对神经细胞的保护作用. 内容 持续氧化应激可使PARP-1过度活化,促进凋亡诱导因子(apoptosis induced factor,AIF)转位至细胞核,介导PARthanatos.缺血/再灌注以及谷氨酸兴奋性毒性作用均可产生大量氧自由基,是神经系统疾病主要致病物质.脑卒中和神经退行性疾病中存在持续氧化应激和PARP-1活化,其介导的PARthanatos是神经元死亡的主要方式之一.抑制PARP-1

  4. Approche morphologique de la fragmentation de l'ADN radio-induite par immunomarquage anti-poly (ADP-ribose) polymérase (PARP) : étude de cultures d'oligodendrogliomes

    Science.gov (United States)

    Varlet, P.; Beuvon, F.; Cervera, P.; Averbeck, D.; Daumas-Duport, C.

    1998-04-01

    Poly (ADP-ribose) polymerase (PARP) is a nuclear enzyme encompassing two zinc finger motifs which specifically binds to radiation induced DNA strand breaks. We develop a new immuno-labelling of poly ADP-ribose which coupled together with the immunodetection of cells in cycle with MIB1, permits to detect and quantify the DNA fragmentation induced by radiations (Cesium137). This method, applied to organotypical cultures of human oligodendroglioma, submitted to radiation, a dose dependant nuclear signal. This one increased significantly in the presence of a radiosensitizer like iododeoxyuridine (IUDR 5 g/ml). This poly ADP-ribose immunodetection can be useful, to detect furtherly the individual radiosensitivity of human glioma. Les protéases “ICE-like" ou caspases, sont les homologues humaines du produit du gène ced-3 du ver Caenorhabditis elegans et sont activées lors des étapes précoces de l'apoptose. L'objectif de ce travail vise à déterminer dans quelle mesure l'inhibition de l'une d'entre elles, la caspase-3 est susceptible de modifier la sensibilité des cellules vis-à-vis de l'apoptose radioinduite. Des lymphocytes spléniques murins irradiés en présence de Ac-DVED-CHO un inhibiteur spécifique de la caspase-3 présentent un taux de particules hypodiploïdes radioinduites bien inférieur à celui des contrôles et une diminution drastique de la fragmentation internucléosomale de l'ADN. Toutefois, ni l'externalisation des phospholipides anioniques, autre marqueur spécifique de l'apoptose, ni la viabilité ne sont affectées.

  5. Sphingosine 1-phosphate inhibits activation of caspases that cleave poly(ADP-ribose) polymerase and lamins during Fas- and ceramide-mediated apoptosis in Jurkat T lymphocytes.

    Science.gov (United States)

    Cuvillier, O; Rosenthal, D S; Smulson, M E; Spiegel, S

    1998-01-30

    Ceramide, a sphingolipid generated by the hydrolysis of membrane-associated sphingomyelin, appears to play a role as a gauge of apoptosis. A further metabolite of ceramide, sphingosine 1-phosphate (SPP), prevents ceramide-mediated apoptosis, and it has been suggested that the balance between intracellular ceramide and SPP levels may determine the cell fate (Cuvillier, O., Pirianov, G, Kleuser, B., Vanek, P. G., Coso, O. A., Gutkind, J. S., and Spiegel, S. (1996) Nature 381, 800-803). Here, we investigated the role of SPP and the protein kinase C activator, phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA), in the caspase cascade leading to the proteolysis of poly(ADP-ribose) polymerase (PARP) and lamins. In Jurkat T cells, Fas ligation or addition of exogenous C2-ceramide induced activations of caspase-3/CPP32 and caspase-7/Mch3 followed by PARP cleavage, effects that can be blocked either by SPP or TPA. Furthermore, both SPP and TPA inhibit the activation of caspase-6/Mch2 and subsequent lamin B cleavage. Ceramide, in contrast to Fas ligation, did not induce activation of caspase-8/FLICE and neither SPP nor TPA were able to prevent this activation. Thus, SPP, likely generated via protein kinase C-mediated activation of sphingosine kinase, suppresses the apoptotic pathway downstream of FLICE but upstream of the executioner caspases, caspase-3, -6, and -7. PMID:9446602

  6. Cross talk between poly(ADP-ribose polymerase 1 methylation and oxidative stress involved in the toxic effect of anatase titanium dioxide nanoparticles

    Directory of Open Access Journals (Sweden)

    Bai W

    2015-09-01

    Full Text Available Wenlin Bai,1,2 Yujiao Chen,1,2 Ai Gao1,2 1Department of Occupational Health and Environmental Health, School of Public Health, 2Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, People’s Republic of China Abstract: Given the tremendous growth in the application of titanium dioxide nanoparticles (TNPs, concerns about the potential health hazards of TNPs to humans have been raised. Poly(ADP-ribose polymerase 1 (PARP-1, a highly conserved DNA-binding protein, is involved in many molecular and cellular processes. Limited data demonstrated that certain nanomaterials induced the aberrant hypermethylation of PARP-1. However, the mechanism involved in TNP-induced PARP-1 abnormal methylation has not been studied. A549 cells were incubated with anatase TNPs (22.1 nm for 24 hours pretreatment with or without methyltransferase inhibitor 5-aza-2'-deoxycytidine and the reactive oxygen species (ROS scavenger α-lipoic acid to assess the possible role of methylation and ROS in the toxic effect of TNPs. After TNPs characterization, a battery of assays was performed to evaluate the toxic effect of TNPs, PARP-1 methylation status, and oxidative damage. Results showed that TNPs decreased the cell viability in a dose-dependent manner, in accordance with the increase of lactate dehydrogenase activity, which indicated membrane damage of cells. Similar to the high level of PARP-1 methylation, the generation of ROS was significantly increased after exposure to TNPs for 24 hours. Furthermore, α-lipoic acid decreased TNP-induced ROS generation and then attenuated TNP-triggered PARP-1 hypermethylation. Meanwhile, 5-aza-2'-deoxycytidine simultaneously decreased the ROS generation induced by TNPs, resulting in the decline of PARP-1 methylation. In summary, TNPs triggered the aberrant hypermethylation of the PARP-1 promoter and there was a cross talk between oxidative stress and PARP-1 methylation in the toxic effect of TNPs

  7. Poly (ADP-ribose polymerase plays an important role in intermittent hypoxia-induced cell death in rat cerebellar granule cells

    Directory of Open Access Journals (Sweden)

    Chiu Sheng-Chun

    2012-03-01

    Full Text Available Abstract Background Episodic cessation of airflow during sleep in patients with sleep apnea syndrome results in intermittent hypoxia (IH. Our aim was to investigate the effects of IH on cerebellar granule cells and to identify the mechanism of IH-induced cell death. Methods Cerebellar granule cells were freshly prepared from neonatal Sprague-Dawley rats. IH was created by culturing the cerebellar granule cells in the incubators with oscillating O2 concentration at 20% and 5% every 30 min for 1-4 days. The results of this study are based on image analysis using a confocal microscope and associated software. Cellular oxidative stress increased with increase in IH. In addition, the occurrence of cell death (apoptosis and necrosis increased as the duration of IH increased, but decreased in the presence of an iron chelator (phenanthroline or poly (ADP-ribose polymerase (PARP inhibitors [3-aminobenzamide (3-AB and DPQ]. The fluorescence of caspase-3 remained the same regardless of the duration of IH, and Western blots did not detect activation of caspase-3. However, IH increased the ratio of apoptosis-inducing factor (AIF translocation to the nucleus, while PARP inhibitors (3-AB reduced this ratio. Results According to our findings, IH increased oxidative stress and subsequently leading to cell death. This effect was at least partially mediated by PARP activation, resulting in ATP depletion, calpain activation leading to AIF translocation to the nucleus. Conclusions We suggest that IH induces cell death in rat primary cerebellar granule cells by stimulating oxidative stress PARP-mediated calpain and AIF activation.

  8. Modulation of farnesoid X receptor results in post-translational modification of poly (ADP-ribose) polymerase 1 in the liver

    International Nuclear Information System (INIS)

    The farnesoid X receptor (FXR) is a bile acid-activated transcription factor belonging to the nuclear receptor superfamily. FXR deficiency in mice results in cholestasis, metabolic disorders, and tumorigenesis in liver and intestine. FXR is known to contribute to pathogenesis by regulating gene transcription; however, changes in the post-transcriptional modification of proteins associated with FXR modulation have not been determined. In the current study, proteomic analysis of the livers of wild-type (WT) and FXR knockout (FXR-KO) mice treated with a FXR synthetic ligand or vehicle was performed. The results identified five proteins as novel FXR targets. Since FXR deficiency in mice leads to liver tumorigenesis, poly (ADP-ribose) polymerase family, member 1 (Parp1) that is important for DNA repair, was validated in the current study by quantitative real-time PCR, and 1- and 2-dimensional gel electrophoresis/western blot. The results showed that Parp1 mRNA levels were not altered by FXR genetic status or by agonist treatment. However, total Parp1 protein levels were increased in FXR-KO mice as early as 3 month old. Interestingly, total Parp1 protein levels were increased in WT mice in an age-dependent manner (from 3 to 18 months), but not in FXR-KO mice. Finally, activation of FXR in WT mice resulted in reduction of phosporylated Parp1 protein in the liver without affecting total Parp1 protein levels. In conclusion, this study reveals that FXR genetic status and agonist treatment affects basal levels and phosphorylation state of Parp1, respectively. These alterations, in turn, may be associated with the hepatobiliary alterations observed in FXR-KO mice and participate in FXR agonist-induced protection in the liver. -- Highlights: ► Proteomic analysis identified novel FXR targets. ► FXR modification altered post-translational modification of the Parp1 protein. ► Altered Parp1 function may contribute to mechanisms of FXR regulation of liver functions.

  9. Modulation of farnesoid X receptor results in post-translational modification of poly (ADP-ribose) polymerase 1 in the liver

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yan [Department of General Surgery, Xuanwu Hospital, Capital Medical University, Beijing (China); Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Li, Guodong [Department of Surgical Oncology, Cancer Treatment Center, Fourth Affiliated Hospital of Harbin Medical University, Harbin (China); Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Dong, Yafeng; Zhou, Helen H. [Department of Obstetrics and Gynecologic, University of Kansas Medical Center, Kansas City, KS (United States); Kong, Bo; Aleksunes, Lauren M. [Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ (United States); Richardson, Jason R. [Environmental and Occupational Medicine, UMDNJ—Robert Wood Johnson Medical School, Piscataway, NJ (United States); Li, Fei, E-mail: xw_lifei@yahoo.com.cn [Department of General Surgery, Xuanwu Hospital, Capital Medical University, Beijing (China); Guo, Grace L., E-mail: guo@eohsi.rutgers.edu [Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ (United States)

    2013-01-15

    The farnesoid X receptor (FXR) is a bile acid-activated transcription factor belonging to the nuclear receptor superfamily. FXR deficiency in mice results in cholestasis, metabolic disorders, and tumorigenesis in liver and intestine. FXR is known to contribute to pathogenesis by regulating gene transcription; however, changes in the post-transcriptional modification of proteins associated with FXR modulation have not been determined. In the current study, proteomic analysis of the livers of wild-type (WT) and FXR knockout (FXR-KO) mice treated with a FXR synthetic ligand or vehicle was performed. The results identified five proteins as novel FXR targets. Since FXR deficiency in mice leads to liver tumorigenesis, poly (ADP-ribose) polymerase family, member 1 (Parp1) that is important for DNA repair, was validated in the current study by quantitative real-time PCR, and 1- and 2-dimensional gel electrophoresis/western blot. The results showed that Parp1 mRNA levels were not altered by FXR genetic status or by agonist treatment. However, total Parp1 protein levels were increased in FXR-KO mice as early as 3 month old. Interestingly, total Parp1 protein levels were increased in WT mice in an age-dependent manner (from 3 to 18 months), but not in FXR-KO mice. Finally, activation of FXR in WT mice resulted in reduction of phosporylated Parp1 protein in the liver without affecting total Parp1 protein levels. In conclusion, this study reveals that FXR genetic status and agonist treatment affects basal levels and phosphorylation state of Parp1, respectively. These alterations, in turn, may be associated with the hepatobiliary alterations observed in FXR-KO mice and participate in FXR agonist-induced protection in the liver. -- Highlights: ► Proteomic analysis identified novel FXR targets. ► FXR modification altered post-translational modification of the Parp1 protein. ► Altered Parp1 function may contribute to mechanisms of FXR regulation of liver functions.

  10. Discovery of novel poly(ADP-ribose) glycohydrolase inhibitors by a quantitative assay system using dot-blot with anti-poly(ADP-ribose)

    Energy Technology Data Exchange (ETDEWEB)

    Okita, Naoyuki, E-mail: nokita7@rs.noda.tus.ac.jp [Genome and Drug Research Center, Tokyo University of Science (Japan); Ashizawa, Daisuke; Ohta, Ryo [Department of Biochemistry, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-0022 (Japan); Abe, Hideaki [Genome and Drug Research Center, Tokyo University of Science (Japan); Department of Biochemistry, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-0022 (Japan); Tanuma, Sei-ichi, E-mail: tanuma@rs.noda.tus.ac.jp [Genome and Drug Research Center, Tokyo University of Science (Japan); Department of Biochemistry, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-0022 (Japan)

    2010-02-19

    Poly(ADP-ribosyl)ation, which is mainly regulated by poly(ADP-ribose) polymerase (PARP) and poly(ADP-ribose) glycohydrolase (PARG), is a unique protein modification involved in cellular responses such as DNA repair and replication. PARG hydrolyzes glycosidic linkages of poly(ADP-ribose) synthesized by PARP and liberates ADP-ribose residues. Recent studies have suggested that inhibitors of PARG are able to be potent anti-cancer drug. In order to discover the potent and specific Inhibitors of PARG, a quantitative and high-throughput screening assay system is required. However, previous PARG assay systems are not appropriate for high-throughput screening because PARG activity is measured by radioactivities of ADP-ribose residues released from radioisotope (RI)-labeled poly(ADP-ribose). In this study, we developed a non-RI and quantitative assay system for PARG activity based on dot-blot assay using anti-poly(ADP-ribose) and nitrocellulose membrane. By our method, the maximum velocity (V{sub max}) and the michaelis constant (k{sub m}) of PARG reaction were 4.46 {mu}M and 128.33 {mu}mol/min/mg, respectively. Furthermore, the IC50 of adenosine diphosphate (hydroxymethyl) pyrrolidinediol (ADP-HPD), known as a non-competitive PARG inhibitor, was 0.66 {mu}M. These kinetics values were similar to those obtained by traditional PARG assays. By using our assay system, we discovered two novel PARG inhibitors that have xanthene scaffold. Thus, our quantitative and convenient method is useful for a high-throughput screening of PARG specific inhibitors.

  11. Poly (ADP) ribose polymerase enzyme inhibitor, veliparib, potentiates chemotherapy and radiation in vitro and in vivo in small cell lung cancer

    International Nuclear Information System (INIS)

    Poly (ADP) ribose polymerase (PARP) plays a key role in DNA repair and is highly expressed in small cell lung cancer (SCLC). We investigated the therapeutic impact of PARP inhibition in SCLC. In vitro cytotoxicity of veliparib, cisplatin, carboplatin, and etoposide singly and combined was determined by MTS in 9 SCLC cell lines (H69, H128, H146, H526, H187, H209, DMS53, DMS153, and DMS114). Subcutaneous xenografts in athymic nu/nu mice of H146 and H128 cells with relatively high and low platinum sensitivity, respectively, were employed for in vivo testing. Mechanisms of differential sensitivity of SCLC cell lines to PARP inhibition were investigated by comparing protein and gene expression profiles of the platinum sensitive and the less sensitive cell lines. Veliparib showed limited single-agent cytotoxicity but selectively potentiated (≥50% reduction in IC50) cisplatin, carboplatin, and etoposide in vitro in five of nine SCLC cell lines. Veliparib with cisplatin or etoposide or with both cisplatin and etoposide showed greater delay in tumor growth than chemotherapy alone in H146 but not H128 xenografts. The potentiating effect of veliparib was associated with in vitro cell line sensitivity to cisplatin (CC = 0.672; P = 0.048) and DNA-PKcs protein modulation. Gene expression profiling identified differential expression of a 5-gene panel (GLS, UBEC2, HACL1, MSI2, and LOC100129585) in cell lines with relatively greater sensitivity to platinum and veliparib combination. Veliparib potentiates standard cytotoxic agents against SCLC in a cell-specific manner. This potentiation correlates with platinum sensitivity, DNA-PKcs expression and a 5-gene expression profile

  12. Evaluation of poly (ADP-ribose) polymerase inhibitor ABT-888 combined with radiotherapy and temozolomide in glioblastoma

    International Nuclear Information System (INIS)

    The cytotoxicity of radiotherapy and chemotherapy can be enhanced by modulating DNA repair. PARP is a family of enzymes required for an efficient base-excision repair of DNA single-strand breaks and inhibition of PARP can prevent the repair of these lesions. The current study investigates the trimodal combination of ABT-888, a potent inhibitor of PARP1-2, ionizing radiation and temozolomide(TMZ)-based chemotherapy in glioblastoma (GBM) cells. Four human GBM cell lines were treated for 5 h with 5 μM ABT-888 before being exposed to X-rays concurrently with TMZ at doses of 5 or 10 μM for 2 h. ABT-888′s PARP inhibition was measured using immunodetection of poly(ADP-ribose) (pADPr). Cell survival and the different cell death pathways were examined via clonogenic assay and morphological characterization of the cell and cell nucleus. Combining ABT-888 with radiation yielded enhanced cell killing in all four cell lines, as demonstrated by a sensitizer enhancement ratio at 50% survival (SER50) ranging between 1.12 and 1.37. Radio- and chemo-sensitization was further enhanced when ABT-888 was combined with both X-rays and TMZ in the O6-methylguanine-DNA-methyltransferase (MGMT)-methylated cell lines with a SER50 up to 1.44. This effect was also measured in one of the MGMT-unmethylated cell lines with a SER50 value of 1.30. Apoptosis induction by ABT-888, TMZ and X-rays was also considered and the effect of ABT-888 on the number of apoptotic cells was noticeable at later time points. In addition, this work showed that ABT-888 mediated sensitization is replication dependent, thus demonstrating that this effect might be more pronounced in tumour cells in which endogenous replication lesions are present in a larger proportion than in normal cells. This study suggests that ABT-888 has the clinical potential to enhance the current standard treatment for GBM, in combination with conventional chemo-radiotherapy. Interestingly, our results suggest that the use of PARP inhibitors

  13. p38γ Mitogen-Activated Protein Kinase Contributes to Oncogenic Properties Maintenance and Resistance to Poly (ADP-Ribose-Polymerase-1 Inhibition in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Fanyan Meng

    2011-05-01

    Full Text Available p38γ MAPK, one of the four members of p38 mitogen-activated protein kinases (MAPKs, has previously been shown to harbor oncogenic functions. However, the biologic function of p38γ MAPK in breast cancer has not been well defined. In this study, we have shown that p38γ MAPK is overexpressed in highly metastatic human and mouse breast cancer cell lines and p38γ MAPK expression is preferentially associated with basal-like and metastatic phenotypes of breast tumor samples. Ectopic expression of p38γ MAPK did not lead to an increase in oncogenic properties in vitro in most tested mammary epithelial cells. However, knockdown of p38γ MAPK expression resulted in a dramatic decrease in cell proliferation, colony formation, cell migration, invasion in vitro and significant retardation of tumorigenesis, and long-distance metastasis to the lungs in vivo. Moreover, knockdown of p38γ MAPK triggered the activation of AKT signaling. Inhibition of this feedback loop with various PI3K/AKT signaling inhibitors facilitated the effect of targeting p38γ MAPK. We further found that overexpression of p38γ MAPK did not promote cell resistance to chemotherapeutic agents doxorubicin and paclitaxel but significantly increased cell resistance to PJ-34, a DNA damage agent poly (ADP-ribose-polymerase-1 (PARP inhibitor in vitro and in vivo. Finally, we identified that p38γ MAPK overexpression led to marked cell cycle arrest in G2/M phase. Our study for the first time clearly demonstrates that p38γ MAPK is a promising target for the design of targeted therapies for basal-like breast cancer with metastatic characteristics and for overcoming potential resistance against the PARP inhibitor.

  14. Vault Poly(ADP-Ribose) Polymerase Is Associated with Mammalian Telomerase and Is Dispensable for Telomerase Function and Vault Structure In Vivo

    OpenAIRE

    Liu, Yie; Snow, Bryan E.; Kickhoefer, Valerie A; Erdmann, Natalie; Zhou, Wen; Wakeham, Andrew; Gomez, Marla; Rome, Leonard H.; Harrington, Lea

    2004-01-01

    Vault poly(ADP-ribose) polymerase (VPARP) was originally identified as a minor protein component of the vault ribonucleoprotein particle, which may be involved in molecular assembly or subcellular transport. In addition to the association of VPARP with the cytoplasmic vault particle, subpopulations of VPARP localize to the nucleus and the mitotic spindle, indicating that VPARP may have other cellular functions. We found that VPARP was associated with telomerase activity and interacted with ex...

  15. Beyond DNA Repair: Additional Functions of PARP-1 in Cancer

    OpenAIRE

    Weaver, Alice N.; Eddy S. Yang

    2013-01-01

    Poly(ADP-ribose) polymerases (PARPs) are DNA-dependent nuclear enzymes that transfer negatively charged ADP-ribose moieties from cellular nicotinamide-adenine-dinucleotide (NAD+) to a variety of protein substrates, altering protein–protein and protein-DNA interactions. The most studied of these enzymes is poly(ADP-ribose) polymerase-1 (PARP-1), which is an excellent therapeutic target in cancer due to its pivotal role in the DNA damage response. Clinical studies have shown susceptibility to P...

  16. The Sound of Silence: RNAi in Poly (ADP-Ribose Research

    Directory of Open Access Journals (Sweden)

    Felix R. Althaus

    2012-12-01

    Full Text Available Poly(ADP-ribosyl-ation is a nonprotein posttranslational modification of proteins and plays an integral part in cell physiology and pathology. The metabolism of poly(ADP-ribose (PAR is regulated by its synthesis by poly(ADP-ribose polymerases (PARPs and on the catabolic side by poly(ADP-ribose glycohydrolase (PARG. PARPs convert NAD+ molecules into PAR chains that interact covalently or noncovalently with target proteins and thereby modify their structure and functions. PAR synthesis is activated when PARP1 and PARP2 bind to DNA breaks and these two enzymes account for almost all PAR formation after genotoxic stress. PARG cleaves PAR molecules into free PAR and finally ADP-ribose (ADPR moieties, both acting as messengers in cellular stress signaling. In this review, we discuss the potential of RNAi to manipulate the levels of PARPs and PARG, and consequently those of PAR and ADPR, and compare the results with those obtained after genetic or chemical disruption.

  17. Deficiency of terminal ADP-ribose protein glycohydrolase TARG1/C6orf130 in neurodegenerative disease

    Science.gov (United States)

    Sharifi, Reza; Morra, Rosa; Denise Appel, C; Tallis, Michael; Chioza, Barry; Jankevicius, Gytis; Simpson, Michael A; Matic, Ivan; Ozkan, Ege; Golia, Barbara; Schellenberg, Matthew J; Weston, Ria; Williams, Jason G; Rossi, Marianna N; Galehdari, Hamid; Krahn, Juno; Wan, Alexander; Trembath, Richard C; Crosby, Andrew H; Ahel, Dragana; Hay, Ron; Ladurner, Andreas G; Timinszky, Gyula; Williams, R Scott; Ahel, Ivan

    2013-01-01

    Adenosine diphosphate (ADP)-ribosylation is a post-translational protein modification implicated in the regulation of a range of cellular processes. A family of proteins that catalyse ADP-ribosylation reactions are the poly(ADP-ribose) (PAR) polymerases (PARPs). PARPs covalently attach an ADP-ribose nucleotide to target proteins and some PARP family members can subsequently add additional ADP-ribose units to generate a PAR chain. The hydrolysis of PAR chains is catalysed by PAR glycohydrolase (PARG). PARG is unable to cleave the mono(ADP-ribose) unit directly linked to the protein and although the enzymatic activity that catalyses this reaction has been detected in mammalian cell extracts, the protein(s) responsible remain unknown. Here, we report the homozygous mutation of the c6orf130 gene in patients with severe neurodegeneration, and identify C6orf130 as a PARP-interacting protein that removes mono(ADP-ribosyl)ation on glutamate amino acid residues in PARP-modified proteins. X-ray structures and biochemical analysis of C6orf130 suggest a mechanism of catalytic reversal involving a transient C6orf130 lysyl-(ADP-ribose) intermediate. Furthermore, depletion of C6orf130 protein in cells leads to proliferation and DNA repair defects. Collectively, our data suggest that C6orf130 enzymatic activity has a role in the turnover and recycling of protein ADP-ribosylation, and we have implicated the importance of this protein in supporting normal cellular function in humans. PMID:23481255

  18. 聚(ADP-核糖)聚合酶-1在糖尿病神经病变中的作用%Role of poly(ADP-ribose) polymerase-1 in diabetic neuropathy

    Institute of Scientific and Technical Information of China (English)

    项舟弘; 苏青

    2010-01-01

    聚(ADP-核糖)聚合酶(PARP)-1是一类具有重要生理功能的核酶,它在糖尿病神经病变的发病中发挥重要作用.PARP-1活化导致NAD~+耗竭、能量衰竭、转录调控和基因表达发生改变、3-磷酸甘油醛脱氧酶受抑制,从而参与糖尿病神经病变的发生、发展.多个动物实验显示PARP-1抑制剂对糖尿病神经病变有改善作用,为治疗糖尿病神经病变的新药研发指明了方向.%Poly(ADP-ribose) polymerase (PARP)-1 is a nuclear enzyme with multiple physiologi-cal functions,emerging as a fundamental mechanism in the pathogenesis of diabetic neuropathy.PARP-1 acti-vation results in NAD~+ depletion, energy failure, changes of transcriptional regulation and gene expression,in-hibition of the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase,which towards the pathways im-plicated in diabetic neuropathy.Several animal tests showed that treatment with PARP-1 inhibitor could im-prove diabetic neuropathy, so it may be a new spot in new drug research.

  19. 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; 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. PMID:26627003

  20. The Poly(ADP-ribose) Polymerase Enzyme Tankyrase Antagonizes Activity of the β-Catenin Destruction Complex through ADP-ribosylation of Axin and APC2.

    Science.gov (United States)

    Croy, Heather E; Fuller, Caitlyn N; Giannotti, Jemma; Robinson, Paige; Foley, Andrew V A; Yamulla, Robert J; Cosgriff, Sean; Greaves, Bradford D; von Kleeck, Ryan A; An, Hyun Hyung; Powers, Catherine M; Tran, Julie K; Tocker, Aaron M; Jacob, Kimberly D; Davis, Beckley K; Roberts, David M

    2016-06-10

    Most colon cancer cases are initiated by truncating mutations in the tumor suppressor, adenomatous polyposis coli (APC). APC is a critical negative regulator of the Wnt signaling pathway that participates in a multi-protein "destruction complex" to target the key effector protein β-catenin for ubiquitin-mediated proteolysis. Prior work has established that the poly(ADP-ribose) polymerase (PARP) enzyme Tankyrase (TNKS) antagonizes destruction complex activity by promoting degradation of the scaffold protein Axin, and recent work suggests that TNKS inhibition is a promising cancer therapy. We performed a yeast two-hybrid (Y2H) screen and uncovered TNKS as a putative binding partner of Drosophila APC2, suggesting that TNKS may play multiple roles in destruction complex regulation. We find that TNKS binds a C-terminal RPQPSG motif in Drosophila APC2, and that this motif is conserved in human APC2, but not human APC1. In addition, we find that APC2 can recruit TNKS into the β-catenin destruction complex, placing the APC2/TNKS interaction at the correct intracellular location to regulate β-catenin proteolysis. We further show that TNKS directly PARylates both Drosophila Axin and APC2, but that PARylation does not globally regulate APC2 protein levels as it does for Axin. Moreover, TNKS inhibition in colon cancer cells decreases β-catenin signaling, which we find cannot be explained solely through Axin stabilization. Instead, our findings suggest that TNKS regulates destruction complex activity at the level of both Axin and APC2, providing further mechanistic insight into TNKS inhibition as a potential Wnt pathway cancer therapy. PMID:27068743

  1. Effect of the regimen of Gaoshan Hongjingtian on the mechanism of poly(ADP-ribose) polymerase regulation of nuclear factor kappa B in the experimental diabetic retinopathy

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hong-shu; SHI Xiang-yu; WEI Wen-bin; WANG Ning-li

    2013-01-01

    Background Poly(ADP-ribose) polymerase (PARP) plays an important role in the death of retinal capillary cells indiabetic retinopathy (DR) partly via its regulation of nuclear factor kappa B (NF-κB).The current study investigated theeffect of the regimen of Gaoshan Hongjingtian (RG) on the mechanism of PARP regulation of NF-KB,and demonstratedthe possible impact of the RG and Gaoshan Hongjingtian (Rhodiola sachalinensis,RS) on diabetic retinopathy.Methods Wistar rats were made diabetic by administering streptozotocin.They were then assigned to three groups atrandom.After 2 months,the three groups of these diabetic rats were treated with RS or RG,or untreated.Analyses ofexpression levels of PARP,NF-κB,and intercellular adhesion molecule-1 (ICAM-1) in the retinas of rats in differentgroups were performed by Western blotting and immunohistochemical assays,and mRNA levels of NF-κB and ICAM-1were determined by real-time polymerase chain reaction (PCR).In addition,the basement membranes of capillaries inthe rats' retinas were observed using electron microscopy,and diabetes-induced capillary degeneration (ghost pericytesand acellular capillaries) were quantitated.Results From the third month after the injection of streptozotocin,the diabetic rats were given daily RG,RS or tap water separately.The diabetic rats failed to gain weight compared with normal age-matched rats,whereas their glycated hemoglobin levels were significantly increased.After 5 months,the mRNA levels of NF-κB and ICAM-1 and the protein expression of PAPP,NF-κB,and ICAM-1 were significantly increased in the retinas of diabetic rats in the untreated group compared with the nondiabetic controls.After 8 months,the number of degenerated retinal capillaries (ghost pericytes and acellular capillaries) was significantly increased in the diabetic rats in the untreated group compared with normal age-matched rats.RG and RS inhibited diabetes-induced over-expression of PARP,NF-κB,and ICAM-1 in the retinas of

  2. Altered poly(ADP-ribose) metabolism impairs cellular responses to genotoxic stress in a hypomorphic mutant of poly(ADP-ribose) glycohydrolase

    International Nuclear Information System (INIS)

    Genotoxic stress activates nuclear poly(ADP-ribose) (PAR) metabolism leading to PAR synthesis catalyzed by DNA damage activated poly(ADP-ribose) polymerases (PARPs) and rapid PAR turnover by action of nuclear poly(ADP-ribose) glycohydrolase (PARG). The involvement of PARP-1 and PARP-2 in responses to DNA damage has been well studied but the involvement of nuclear PARG is less well understood. To gain insights into the function of nuclear PARG in DNA damage responses, we have quantitatively studied PAR metabolism in cells derived from a hypomorphic mutant mouse model in which exons 2 and 3 of the PARG gene have been deleted (PARG-Δ2,3 cells), resulting in a nuclear PARG containing a catalytic domain but lacking the N-terminal region (A domain) of the protein. Following DNA damage induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), we found that the activity of both PARG and PARPs in intact cells is increased in PARG-Δ2,3 cells. The increased PARG activity leads to decreased PARP-1 automodification with resulting increased PARP activity. The degree of PARG activation is greater than PARP, resulting in decreased PAR accumulation. Following MNNG treatment, PARG-Δ2,3 cells show reduced formation of XRCC1 foci, delayed H2AX phosphorylation, decreased DNA break intermediates during repair, and increased cell death. Our results show that a precise coordination of PARPs and PARG activities is important for normal cellular responses to DNA damage and that this coordination is defective in the absence of the PARG A domain

  3. Profiling of Biomarkers for the Exposure of Polycyclic Aromatic Hydrocarbons: Lamin-A/C Isoform 3, Poly[ADP-ribose] Polymerase 1, and Mitochondria Copy Number Are Identified as Universal Biomarkers

    Directory of Open Access Journals (Sweden)

    Hwan-Young Kim

    2014-01-01

    Full Text Available This study investigated the profiling of polycyclic aromatic hydrocarbon- (PAH- induced genotoxicity in cell lines and zebrafish. Each type of cells displayed different proportionality of apoptosis. Mitochondrial DNA (mtDNA copy number was dramatically elevated after 5-day treatment of fluoranthene and pyrene. The notable deregulated proteins for PAHs exposure were displayed as follows: lamin-A/C isoform 3 and annexin A1 for benzopyrene; lamin-A/C isoform 3 and DNA topoisomerase 2-alpha for pentacene; poly[ADP-ribose] polymerase 1 (PARP-1 for fluoranthene; and talin-1 and DNA topoisomerase 2-alpha for pyrene. Among them, lamin-A/C isoform 3 and PARP-1 were further confirmed using mRNA and protein expression study. Obvious morphological abnormalities including curved backbone and cardiomegaly in zebrafish were observed in the 54 hpf with more than 400 nM of benzopyrene. In conclusion, the change of mitochondrial genome (increased mtDNA copy number was closely associated with PAH exposure in cell lines and mesenchymal stem cells. Lamin-A/C isoform 3, talin-1, and annexin A1 were identified as universal biomarkers for PAHs exposure. Zebrafish, specifically at embryo stage, showed suitable in vivo model for monitoring PAHs exposure to hematopoietic tissue and other organs.

  4. Poly(ADP-ribose) polymerase inhibitors suppress UV-induced human immunodeficiency virus type 1 gene expression at the posttranscriptional level

    International Nuclear Information System (INIS)

    Gene expression of human immunodeficiency virus type 1 (HIV-1) is induced not only by trans activation mediated through a gene product (tat) encoded by the virus but also by treatment of virus-carrying cells with DNA-damaging agents such as UV light. Employing an artificially constructed DNA in which the chloramphenicol acetyltransferase gene was placed under the control of the HIV-1 long terminal repeat, we analyzed the induction process in HeLa cells and found that inhibitors of poly(ADP-ribose) polymerase suppressed UV-induced HIV-1 gene expression but not tat-mediated expression. We also found that suppression occurs at the posttranscriptional level. These results indicate that HIV-1 gene expression is activated by at least two different mechanisms, one of which involves poly-ADP ribosylation. A possible new role of poly-ADP ribosylation in the regulation of specific gene expression is also discussed

  5. Dual roles of PARP-1 promote cancer growth and progression

    OpenAIRE

    Schiewer, Matthew J.; Goodwin, Jonathan F.; Han, Sumin; Brenner, J. Chad; Augello, Michael A.; Dean, Jeffry L.; Liu, Fengzhi; Planck, Jamie L.; Ravindranathan, Preethi; Chinnaiyan, Arul M.; McCue, Peter; Gomella, Leonard G.; Raj, Ganesh V; Dicker, Adam P.; Brody, Jonathan R

    2012-01-01

    Poly(ADP-ribose) polymerase-1 (PARP-1) is an abundant nuclear enzyme that modifies substrates by poly(ADP-ribose)-ylation. PARP-1 has well-described functions in DNA damage repair, and also functions as a context-specific regulator of transcription factors. Using multiple models, data demonstrate that PARP-1 elicits pro-tumorigenic effects in androgen receptor (AR)-positive prostate cancer (PCa) cells, both in the presence and absence of genotoxic insult. Mechanistically, PARP-1 is recruited ...

  6. Basal Activity of a PARP1-NuA4 Complex Varies Dramatically across Cancer Cell Lines

    OpenAIRE

    Kristin A. Krukenberg; Ruomu Jiang; Judith A. Steen; Timothy J. Mitchison

    2014-01-01

    Poly(ADP-ribose) polymerases (PARPs) catalyze poly(ADP-ribose) addition onto proteins, an important post-translational modification involved in transcription, DNA damage repair, and stem cell identity. Previous studies established the activation of PARP1 in response to DNA damage, but little is known about PARP1 regulation outside of DNA repair. We developed a new assay for measuring PARP activity in cell lysates, and found that the basal activity of PARP1 was highly variable across breast ca...

  7. Glycyrrhetinic acid and its derivatives as inhibitors of poly(ADP-ribose)polymerases 1 and 2, apurinic/apyrimidinic endonuclease 1 and DNA polymerase β

    OpenAIRE

    Salakhutdinov N. F.; Schreiber V.; Khodyreva S. N.; Ilina E. S.; Kutuzov M. M.; Sukhanova M. V.; Salomatina O. V.; Zakharenko A. L.; Lavrik O. I.

    2012-01-01

    Aim. For strengthening the efficiency of monofunctional alkylating antineoplastic drugs it is important to lower the capacity of base excision repair (BER) system which corrects the majority of DNA damages caused by these reagents. The objective was to create inhibitors of the key BER enzymes (PARP1, PARP2, DNA polymerase β, and APE1) by the directed modification of glycyrrhetinic acid (GA). Methods. Amides of GA were produced from the GA acetate by formation of the corresponding acyl chlorid...

  8. Beyond DNA repair: additional functions of PARP-1 in cancer.

    OpenAIRE

    AliceNWeaver; EddySYang

    2013-01-01

    Poly(ADP-ribose) polymerases (PARPs) are DNA-dependent nuclear enzymes that transfer negatively charged ADP-ribose moieties from cellular nicotinamide-adenine-dinucleotide (NAD+) to a variety of protein substrates, altering protein-protein and protein-DNA interactions. The most studied of these enzymes is PARP-1, which is an excellent therapeutic target in cancer due to its pivotal role in the DNA damage response. Clinical studies have shown susceptibility to PARP inhibitors in DNA repair d...

  9. Identification of poly(ADP-ribose) polymerase-1 as the OXPHOS-generated ATP sensor of nuclei of animal cells

    International Nuclear Information System (INIS)

    Our results show that in the intact normal animal cell mitochondrial ATP is directly connected to nuclear PARP-1 by way of a specific adenylate kinase enzymatic path. This mechanism is demonstrated in two models: (a) by its inhibition with a specific inhibitor of adenylate kinase, and (b) by disruption of ATP synthesis through uncoupling of OXPHOS. In each instance the de-inhibited PARP-1 is quantitatively determined by enzyme kinetics. The nuclear binding site of PARP-1 is Topo I, and is identified as a critical 'switchpoint' indicating the nuclear element that connects OXPHOS with mRNA synthesis in real time. The mitochondrial-nuclear PARP-1 pathway is not operative in cancer cells

  10. Wnt/Wingless Pathway Activation Is Promoted by a Critical Threshold of Axin Maintained by the Tumor Suppressor APC and the ADP-Ribose Polymerase Tankyrase.

    Science.gov (United States)

    Wang, Zhenghan; Tacchelly-Benites, Ofelia; Yang, Eungi; Thorne, Curtis A; Nojima, Hisashi; Lee, Ethan; Ahmed, Yashi

    2016-05-01

    Wnt/β-catenin signal transduction directs metazoan development and is deregulated in numerous human congenital disorders and cancers. In the absence of Wnt stimulation, a multiprotein "destruction complex," assembled by the scaffold protein Axin, targets the key transcriptional activator β-catenin for proteolysis. Axin is maintained at very low levels that limit destruction complex activity, a property that is currently being exploited in the development of novel therapeutics for Wnt-driven cancers. Here, we use an in vivo approach in Drosophila to determine how tightly basal Axin levels must be controlled for Wnt/Wingless pathway activation, and how Axin stability is regulated. We find that for nearly all Wingless-driven developmental processes, a three- to fourfold increase in Axin is insufficient to inhibit signaling, setting a lower-limit for the threshold level of Axin in the majority of in vivo contexts. Further, we find that both the tumor suppressor adenomatous polyposis coli (APC) and the ADP-ribose polymerase Tankyrase (Tnks) have evolutionarily conserved roles in maintaining basal Axin levels below this in vivo threshold, and we define separable domains in Axin that are important for APC- or Tnks-dependent destabilization. Together, these findings reveal that both APC and Tnks maintain basal Axin levels below a critical in vivo threshold to promote robust pathway activation following Wnt stimulation. PMID:26975665

  11. Zinc carnosine protects against hydrogen peroxide-induced DNA damage in WIL2-NS lymphoblastoid cell line independent of poly (ADP-Ribose) polymerase expression.

    Science.gov (United States)

    Ooi, Theng Choon; Mohammad, Nur Hafiza; Sharif, Razinah

    2014-12-01

    The aim of this study is to investigate the ability of zinc carnosine to protect the human lymphoblastoid (WIL2-NS) cell line from hydrogen peroxide-induced DNA damage. Cells were cultured with medium containing zinc carnosine at the concentrations of 0.4, 4, 16 and 32 μM for 9 days prior to treatment with 30 μM of hydrogen peroxide (30 min). Zinc carnosine at the concentration 16 μM was optimal in protecting cells from hydrogen peroxide-induced cytotoxicity and gave the lowest percentage of apoptotic and necrotic cells. Results showed that zinc carnosine was able to induce glutathione production and protect cells from hydrogen peroxide-induced oxidative stress at all concentration and the highest protection was observed at 32-μM zinc carnosine culture. Cytokinesis-block micronucleus cytome assay showed that cells cultured with 4-32 μM of zinc carnosine showed significant reduction in micronuclei formation, nucleoplasmic bridges and nuclear bud frequencies (p carnosines possess antioxidant properties and are able to reduce hydrogen peroxide-induced DNA damage in vitro independent of poly(ADP-ribose) polymerase. Further studies are warranted to understand the mechanism of protection of zinc carnosine against hydrogen peroxide-induced damage. PMID:25326781

  12. Vault poly(ADP-ribose) polymerase is associated with mammalian telomerase and is dispensable for telomerase function and vault structure in vivo.

    Science.gov (United States)

    Liu, Yie; Snow, Bryan E; Kickhoefer, Valerie A; Erdmann, Natalie; Zhou, Wen; Wakeham, Andrew; Gomez, Marla; Rome, Leonard H; Harrington, Lea

    2004-06-01

    Vault poly(ADP-ribose) polymerase (VPARP) was originally identified as a minor protein component of the vault ribonucleoprotein particle, which may be involved in molecular assembly or subcellular transport. In addition to the association of VPARP with the cytoplasmic vault particle, subpopulations of VPARP localize to the nucleus and the mitotic spindle, indicating that VPARP may have other cellular functions. We found that VPARP was associated with telomerase activity and interacted with exogenously expressed telomerase-associated protein 1 (TEP1) in human cells. To study the possible role of VPARP in telomerase and vault complexes in vivo, mVparp-deficient mice were generated. Mice deficient in mVparp were viable and fertile for up to five generations, with no apparent changes in telomerase activity or telomere length. Vaults purified from mVparp-deficient mouse liver appeared intact, and no defect in association with other vault components was observed. Mice deficient in mTep1, whose disruption alone does not affect telomere function but does affect the stability of vault RNA, showed no additional telomerase or telomere-related phenotypes when the mTep1 deficiency was combined with an mVparp deficiency. These data suggest that murine mTep1 and mVparp, alone or in combination, are dispensable for normal development, telomerase catalysis, telomere length maintenance, and vault structure in vivo. PMID:15169895

  13. Pyridine Nucleotide Cycling and Control of Intracellular Redox State in Relation to Poly (ADP-Ribose) Polymerase Activity and Nuclear Localization of Glutathione during Exponential Growth of Arabidopsis Cells in Culture

    Institute of Scientific and Technical Information of China (English)

    Till K.Pellny; Vittoria Locato; Pedro Diaz Vivancos; Jelena Markovic; Laura De Gara; Federico V.Pallardó; Christine H.Foyer

    2009-01-01

    Pyridine nucleotides,ascorbate and glutathione are major redox metabolites in plant cells,with specific roles in cellular redox homeostasis and the regulation of the cell cycle.However,the regulation of these metabolite pools during exponential growth and their precise functions in the cell cycle remain to be characterized.The present analysis of the abundance of ascorbate,glutathione,and pyridine nucleotides during exponential growth of Arabidopsis cells in culture provides evidence for the differential regulation of each of these redox pools.Ascorbate was most abundant early in the growth cycle,but glutathione was low at this point.The cellular ascorbate to dehydroascorbate and reduced glutathione (GSH) to glutathione disulphide ratios were high and constant but the pyridine nucleotide pools were largely oxidized over the period of exponential growth and only became more reduced once growth had ceased.The glutathione pool increased in parallel with poly (ADP-ribose) polymerase (PARP) activities and with increases in the abundance of PARP1 and PARP2 mRNAs at a time of high cell cycle activity as indicated by transcriptome information.Marked changes in the intracellular partitioning of GSH between the cytoplasm and nucleus were observed.Extension of the exponential growth phase by dilution or changing the media led to increases in the glutathione and nicotinamide adenine dinucleotide,ox-idized form (NAD)-plus-nicotinamide adenine dinucleotide,reduced form (NADH) pools and to higher NAD/NADH ratios but the nicotinamide adenine dinucleotide phosphate,oxidized form (NADP)-plus-nicotinamide adenine dinucleotide phosphate,reduced form (NADPH) pool sizes,and NAPD/NADPH ratios were much less affected.The ascorbate,glutathi-one,and pyridine nucleotide pools and PARP activity decreased before the exponential growth phase ended.We concludethat there are marked changes in intracellular redox state during the growth cycle but that redox homeostasis is main-rained by interplay

  14. Loss of poly(ADP-ribose) polymerase-1 causes increased tumour latency in p53-deficient mice

    OpenAIRE

    Conde, Carmen; Mark, Manuel; Oliver, F. Javier; Huber, Aline; de Murcia, Gilbert; Ménissier-de Murcia, Josiane

    2001-01-01

    PARP-1-deficient mice display a severe defect in the base excision repair pathway leading to radiosensitivity and genomic instability. They are protected against necrosis induced by massive oxidative stress in various inflammatory processes. Mice lacking p53 are highly predisposed to malignancy resulting from defective cell cycle checkpoints, resistance to DNA damage-induced apoptosis as well as from upregulation of the iNOS gene resulting in chronic oxidative stress. Here, we report the gene...

  15. Cells deficient in PARP1 show an accelerated accumulation of DNA single strand breaks, but not AP sites, over the PARP1-proficient cells exposed to MMS

    OpenAIRE

    Pachkowski, Brian F.; TANO, KEIZO; Afonin, Valeriy; Elder, Rhoderick H.; Takeda, Shunichi; WATANABE, MASAMI; Swenberg, James A; Nakamura, Jun

    2009-01-01

    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, natural...

  16. Poly(ADP-ribose) Regulates Stress Responses and microRNA Activity in the Cytoplasm

    OpenAIRE

    Leung, Anthony K. L.; Vyas, Sejal; Rood, Jennifer E.; Bhutkar, Arjun; Sharp, Phillip A.; Chang, Paul

    2011-01-01

    Poly(ADP-ribose) is a major regulatory macromolecule in the nucleus, where it regulates transcription, chromosome structure and DNA damage repair. Functions in the interphase cytoplasm are less understood. Here we identify a requirement for poly(ADP-ribose) in the assembly of cytoplasmic stress granules, which accumulate RNA-binding proteins that regulate the translation and stability of mRNAs upon stress. We show that poly(ADP-ribose), 6 specific poly(ADP-ribose) polymerases and 2 poly(ADP-r...

  17. A specific isoform of poly(ADP-ribose) glycohydrolase is targeted to the mitochondrial matrix by a N-terminal mitochondrial targeting sequence

    International Nuclear Information System (INIS)

    Poly(ADP-ribose) polymerases (PARPs) convert NAD to polymers of ADP-ribose that are converted to free ADP-ribose by poly(ADP-ribose) glycohydrolase (PARG). The activation of the nuclear enzyme PARP-1 following genotoxic stress has been linked to release of apoptosis inducing factor from the mitochondria, but the mechanisms by which signals are transmitted between nuclear and mitochondrial compartments are not well understood. The study reported here has examined the relationship between PARG and mitochondria in HeLa cells. Endogenous PARG associated with the mitochondrial fraction migrated in the range of 60 kDa. Transient transfection of cells with PARG expression constructs with amino acids encoded by exon 4 at the N-terminus was targeted to the mitochondria as demonstrated by subcellular fractionation and immunofluorescence microscopy of whole cells. Deletion and missense mutants allowed identification of a canonical N-terminal mitochondrial targeting sequence consisting of the first 16 amino acids encoded by PARG exon 4. Sub-mitochondrial localization experiments indicate that this mitochondrial PARG isoform is targeted to the mitochondrial matrix. The identification of a PARG isoform as a component of the mitochondrial matrix raises several interesting possibilities concerning mechanisms of nuclear-mitochondrial cross talk involved in regulation of cell death pathways.

  18. Cytokine-mediated β-cell damage in PARP-1-deficient islets

    OpenAIRE

    Andreone, Teresa; Meares, Gordon P.; Hughes, Katherine J.; Hansen, Polly A.; Corbett, John A.

    2012-01-01

    Poly(ADP)-ribose polymerase (PARP) is an abundant nuclear protein that is activated by DNA damage; once active, it modifies nuclear proteins through attachment of poly(ADP)-ribose units derived from β-nicotinamide adenine dinucleotide (NAD+). In mice, the deletion of PARP-1 attenuates tissue injury in a number of animal models of human disease, including streptozotocin-induced diabetes. Also, inflammatory cell signaling and inflammatory gene expression are attenuated in macrophages isolated f...

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

    OpenAIRE

    Alexander Jonathan S; Chaitanya Ganta; Babu Phanithi

    2010-01-01

    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 ...

  20. Excitotoxicity in the Lung: N-Methyl-D-Aspartate-Induced, Nitric Oxide-Dependent, Pulmonary Edema is Attenuated by Vasoactive Intestinal Peptide and by Inhibitors of Poly(ADP-Ribose) Polymerase

    Science.gov (United States)

    Said, Sami I.; Berisha, Hasan I.; Pakbaz, Hedayatollah

    1996-05-01

    Excitatory amino acid toxicity, resulting from overactivation of N-methyl-D-aspartate (NMDA) glutamate receptors, is a major mechanism of neuronal cell death in acute and chronic neurological diseases. We have investigated whether excitotoxicity may occur in peripheral organs, causing tissue injury, and report that NMDA receptor activation in perfused, ventilated rat lungs triggered acute injury, marked by increased pressures needed to ventilate and perfuse the lung, and by high-permeability edema. The injury was prevented by competitive NMDA receptor antagonists or by channel-blocker MK-801, and was reduced in the presence of Mg2+. As with NMDA toxicity to central neurons, the lung injury was nitric oxide (NO) dependent: it required L-arginine, was associated with increased production of NO, and was attenuated by either of two NO synthase inhibitors. The neuropeptide vasoactive intestinal peptide and inhibitors of poly(ADP-ribose) polymerase also prevented this injury, but without inhibiting NO synthesis, both acting by inhibiting a toxic action of NO that is critical to tissue injury. The findings indicate that: (i) NMDA receptors exist in the lung (and probably elsewhere outside the central nervous system), (ii) excessive activation of these receptors may provoke acute edematous lung injury as seen in the ``adult respiratory distress syndrome,'' and (iii) this injury can be modulated by blockade of one of three critical steps: NMDA receptor binding, inhibition of NO synthesis, or activation of poly(ADP-ribose) polymerase.

  1. Normal telomere length and chromosomal end capping in poly(ADP-ribose) polymerase–deficient mice and primary cells despite increased chromosomal instability

    OpenAIRE

    Samper, Enrique; Goytisolo, Fermín A.; Murcia, Josiane Ménissier-de; González-Suárez, Eva; Cigudosa, Juan C.; de Murcia, Gilbert; Blasco, María A

    2001-01-01

    Poly(ADP-ribose) polymerase (PARP)-1, a detector of single-strand breaks, plays a key role in the cellular response to DNA damage. PARP-1–deficient mice are hypersensitive to genotoxic agents and display genomic instability due to a DNA repair defect in the base excision repair pathway. A previous report suggested that PARP-1–deficient mice also had a severe telomeric dysfunction consisting of telomere shortening and increased end-to-end fusions (d'Adda di Fagagna, F., M.P. Hande, W.-M. Tong,...

  2. Protective effect of the poly(ADP-ribose polymerase inhibitor PJ34 on mitochondrial depolarization-mediated cell death in hepatocellular carcinoma cells involves attenuation of c-Jun N-terminal kinase-2 and protein kinase B/Akt activation

    Directory of Open Access Journals (Sweden)

    Radnai Balazs

    2012-05-01

    Full Text Available Abstract Background 2,4-Dimethoxyphenyl-E-4-arylidene-3-isochromanone (IK11 was previously described to induce apoptotic death of A431 tumor cells. In this report, we investigated the molecular action of IK11 in the HepG2 human hepatocellular carcinoma cell line to increase our knowledge of the role of poly (ADP-ribose-polymerase (PARP, protein kinase B/Akt and mitogen activated protein kinase (MAPK activation in the survival and death of tumor cells and to highlight the possible role of PARP-inhibitors in co-treatments with different cytotoxic agents in cancer therapy. Results We found that sublethal concentrations of IK11 prevented proliferation, migration and entry of the cells into their G2 phase. At higher concentrations, IK11 induced reactive oxygen species (ROS production, mitochondrial membrane depolarization, activation of c-Jun N-terminal kinase 2 (JNK2, and substantial loss of HepG2 cells. ROS production appeared marginal in mediating the cytotoxicity of IK11 since N-acetyl cysteine was unable to prevent it. However, the PARP inhibitor PJ34, although not a ROS scavenger, strongly inhibited both IK11-induced ROS production and cell death. JNK2 activation seemed to be a major mediator of the effect of IK11 since inhibition of JNK resulted in a substantial cytoprotection while inhibitors of the other kinases failed to do so. Inhibition of Akt slightly diminished the effect of IK11, while the JNK and Akt inhibitor and ROS scavenger trans-resveratrol completely protected against it. Conclusions These results indicate significant involvement of PARP, a marginal role of ROS and a pro-apoptotic role of Akt in this system, and raise attention to a novel mechanism that should be considered when cancer therapy is augmented with PARP-inhibition, namely the cytoprotection by inhibition of JNK2.

  3. A high-throughput screening-compatible homogeneous time-resolved fluorescence assay measuring the glycohydrolase activity of human poly(ADP-ribose) glycohydrolase.

    Science.gov (United States)

    Stowell, Alexandra I J; James, Dominic I; Waddell, Ian D; Bennett, Neil; Truman, Caroline; Hardern, Ian M; Ogilvie, Donald J

    2016-06-15

    Poly(ADP-ribose) (PAR) polymers are transient post-translational modifications, and their formation is catalyzed by poly(ADP-ribose) polymerase (PARP) enzymes. A number of PARP inhibitors are in advanced clinical development for BRCA-mutated breast cancer, and olaparib has recently been approved for BRCA-mutant ovarian cancer; however, there has already been evidence of developed resistance mechanisms. Poly(ADP-ribose) glycohydrolase (PARG) catalyzes the hydrolysis of the endo- and exo-glycosidic bonds within the PAR polymers. As an alternative strategy, PARG is a potentially attractive therapeutic target. There is only one PARG gene, compared with 17 known PARP family members, and therefore a PARG inhibitor may have wider application with fewer compensatory mechanisms. Prior to the initiation of this project, there were no known existing cell-permeable small molecule PARG inhibitors for use as tool compounds to assess these hypotheses and no suitable high-throughput screening (HTS)-compatible biochemical assays available to identify start points for a drug discovery project. The development of this newly described high-throughput homogeneous time-resolved fluorescence (HTRF) assay has allowed HTS to proceed and, from this, the identification and advancement of multiple validated series of tool compounds for PARG inhibition. PMID:27036617

  4. Poly(ADP-ribose) in the bone: from oxidative stress signal to structural element.

    Science.gov (United States)

    Hegedűs, Csaba; Robaszkiewicz, Agnieszka; Lakatos, Petra; Szabó, Éva; Virág, László

    2015-05-01

    Contrary to common perception bone is a dynamic organ flexibly adapting to changes in mechanical loading by shifting the delicate balance between bone formation and bone resorption carried out by osteoblasts and osteoclasts, respectively. In the past decades numerous studies demonstrating production of reactive oxygen or nitrogen intermediates, effects of different antioxidants, and involvement of prototypical redox control mechanisms (Nrf2-Keap1, Steap4, FoxO, PAMM, caspase-2) have proven the central role of redox regulation in the bone. Poly(ADP-ribosyl)ation (PARylation), a NAD-dependent protein modification carried out by poly(ADP-ribose) polymerase (PARP) enzymes recently emerged as a new regulatory mechanism fine-tuning osteoblast differentiation and mineralization. Interestingly PARylation does not simply serve as a signaling mechanism during osteoblast differentiation but also couples it to osteoblast death. Even more strikingly, the poly(ADP-ribose) polymer likely released from succumbed cells at the terminal stage of differentiation is incorporated into the bone matrix representing the first structural role of this versatile biopolymer. Moreover, this new paradigm explains why and how osteodifferentiation and death of cells entering this pathway are closely coupled to each other. Here we review the role of reactive oxygen and nitrogen intermediates as well as PARylation in osteoblast and osteoclast differentiation, function, and cell death. PMID:25660995

  5. Poly(ADP-ribose) binding to Chk1 at stalled replication forks is required for S-phase checkpoint activation

    Science.gov (United States)

    Min, Wookee; Bruhn, Christopher; Grigaravicius, Paulius; Zhou, Zhong-Wei; Li, Fu; Krüger, Anja; Siddeek, Bénazir; Greulich, Karl-Otto; Popp, Oliver; Meisezahl, Chris; Calkhoven, Cornelis F.; Bürkle, Alexander; Xu, Xingzhi; Wang, Zhao-Qi

    2013-12-01

    Damaged replication forks activate poly(ADP-ribose) polymerase 1 (PARP1), which catalyses poly(ADP-ribose) (PAR) formation; however, how PARP1 or poly(ADP-ribosyl)ation is involved in the S-phase checkpoint is unknown. Here we show that PAR, supplied by PARP1, interacts with Chk1 via a novel PAR-binding regulatory (PbR) motif in Chk1, independent of ATR and its activity. iPOND studies reveal that Chk1 associates readily with the unperturbed replication fork and that PAR is required for efficient retention of Chk1 and phosphorylated Chk1 at the fork. A PbR mutation, which disrupts PAR binding, but not the interaction with its partners Claspin or BRCA1, impairs Chk1 and the S-phase checkpoint activation, and mirrors Chk1 knockdown-induced hypersensitivity to fork poisoning. We find that long chains, but not short chains, of PAR stimulate Chk1 kinase activity. Collectively, we disclose a previously unrecognized mechanism of the S-phase checkpoint by PAR metabolism that modulates Chk1 activity at the replication fork.

  6. PARP-1 and Ku compete for repair of DNA double strand breaks by distinct NHEJ pathways

    OpenAIRE

    Wang, Minli; Wu, Weizhong; Wu, Wenqi; Rosidi, Bustanur; Zhang, Lihua; Wang, Huichen; Iliakis, George

    2006-01-01

    Poly(ADP-ribose)polymerase 1 (PARP-1) recognizes DNA strand interruptions in vivo and triggers its own modification as well as that of other proteins by the sequential addition of ADP-ribose to form polymers. This modification causes a release of PARP-1 from DNA ends and initiates a variety of responses including DNA repair. While PARP-1 has been firmly implicated in base excision and single strand break repair, its role in the repair of DNA double strand breaks (DSBs) remains unclear. Here, ...

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

    Directory of Open Access Journals (Sweden)

    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.

  8. 系统性红斑狼疮患者外周血单个核细胞中多ADP-核糖聚合酶的表达及其与细胞凋亡的关系%Expression of the poly (ADP-ribose) polymerase and its relationship with apoptosis on peripheral blood mononuclear cells in patients with systemic lupus erythematosus

    Institute of Scientific and Technical Information of China (English)

    陈东育; 李芳; 舒强

    2015-01-01

    目的:探讨多ADP-核糖聚合酶(PARP)在SLE患者外周血单个核细胞中的表达水平及其与细胞凋亡的关系。方法选择SLE活动性、SLE缓解患者和健康对照,应用蛋白印迹法检测各组PBMCs中PARP的表达水平和PARP的裂解片断,应用流式细胞仪检测各组PBMCs的凋亡。统计学方法采用t检验。结果 SLE活动性患者PBMCs凋亡率(16.3±4.0)%明显高于SLE非活动性组患者(5.6±2.9)%和健康对照(5.2±4.2)%(t值分别为4.83和5.05,P<0.05),SLE活动性患者PBMCs PARP的表达(3.2±0.8)明显低于SLE非活动性组患者(7.1±2.2)和健康对照(7.1±2.4)(t值分别为7.66和7.07,P<0.05)。而PARP的裂解片断增多。PBMCs凋亡率和PARP的表达水平在SLE缓解组患者和健康对照组间差异无统计学意义。结论 SLE患者PBMCs中PARP的表达水平显著低于健康对照,随着SLE患者病情的好转,PARP的表达水平逐渐增高。提示PARP的降低可能促进SLE的发生和发展。另外PARP的裂解可能导致SLE患者PBMCs的凋亡增加。%Objective Poly (ADP-ribose) polymerase (PARP) have been demonstrated to play an important role in systemic lupus erythematosus (SLE). In this study we assessed the expression of PARP on peripheral blood mononuclear cells with active or inacte SLE and tried to investigate the relationship between PARP and cell apoptosis on SLE. Methods Thirty definitive SLE patients and 10 healthy controls were enrolled. PBMC were separated from the peripheral blood samples. Western blot technique was applied to analyze the expression of PARP. Flow cytometry were applied to analyze the cell apoptosis. T test were used. Results The cell apoptosis in active patients with SLE was significantly higher than that of inactive patients with SLE and normal controls (the t values were 4.83 and 5.05 respectively, P<0.05). The level of PARP expression was significantly decreased in active patients with SLE as

  9. PARP Inhibitors for the Treatment and Prevention of Breast Cancer

    OpenAIRE

    Vinayak, Shaveta; Ford, James M.

    2010-01-01

    Poly (ADP-ribose) polymerase (PARP) inhibitors, a novel class of drugs that target tumors with DNA repair defects, have received tremendous enthusiasm. Early preclinical studies identified BRCA1 and BRCA2 tumors to be highly sensitive to PARP inhibitors as a result of homologous recombination defect. Based on this premise, PARP inhibitors have been tested in early phase clinical trials as a single agent in BRCA1 or BRCA2 mutation carriers and in combination with chemotherapy in triple-negativ...

  10. PARP-1 Deficiency Increases the Severity of Disease in a Mouse Model of Multiple Sclerosis*

    OpenAIRE

    Selvaraj, Vimal; Soundarapandian, Mangala M.; Chechneva, Olga; Williams, Ambrose J.; Sidorov, Maxim K.; Soulika, Athena M.; Pleasure, David E.; Deng, Wenbin

    2009-01-01

    Poly(ADP-ribose) polymerase-1 (PARP-1) has been implicated in the pathogenesis of several central nervous system (CNS) disorders. However, the role of PARP-1 in autoimmune CNS injury remains poorly understood. Therefore, we studied experimental autoimmune encephalomyelitis (EAE), a model for multiple sclerosis in mice with a targeted deletion of PARP-1. We identified inherent physiological abnormalities in the circulating and splenic immune composition between PARP-1−/− and wild type (WT) mic...

  11. PARP1 inhibitors attenuate AKT phosphorylation via the upregulation of PHLPP1

    OpenAIRE

    Wang, Shuai; Wang, Huibo; Davis, Ben C.; Liang, Jiyong; Cui, Rutao; Chen, Sai-Juan; Xu, Zhi-Xiang

    2011-01-01

    Poly (ADP-ribose) polymerase-1 (PARP1) inhibitors are emerging as an important class of drugs for treating BRCA-deficient cancers. Recent discoveries have shown that PARP1 inhibitors may treat other cancer patients in addition to the relatively small proportion of patients carrying BRCA mutations. However, the additional targets by which PARP1 inhibitor-mediated tumor suppression remain poorly understood. In this study, we show that two PARP1 inhibitors, PJ-34 and 3-AB, attenuate AKT phosphor...

  12. Poly(ADP-ribose) synthesis, a marker of granulocyte differentiation.

    OpenAIRE

    Ikai, K; Ueda, K; Fukushima, M.; Nakamura, T.; Hayaishi, O

    1980-01-01

    By using an indirect immunofluorescence technique, the distribution of poly(ADP-ribose) synthesis in human blood cells was investigated. The antibody used was reactive with poly(ADP-ribose) larger than trimers. The specific immunofluorescence of poly(ADP-ribose) synthesized in situ from NAD+ was observed in nuclei of lymphocytes and monocytes in normal peripheral blood. No immunofluorescence, however, was detected in granulocytes and erythrocytes. In agreement with this finding, no incorporat...

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

    International Nuclear Information System (INIS)

    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 (Cdk5KD or PARP-2KD 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 Cdk5KD and PARP-2KD cells, show that an

  14. PARP-1 activity is required for the reconsolidation and extinction of contextual fear memory

    OpenAIRE

    Inaba, Hiroyoshi; Tsukagoshi, Akinori; Kida, Satoshi

    2015-01-01

    Background Memory consolidation, reconsolidation, and extinction have been shown to require new gene expression. Poly ADP-ribosylation mediated by poly (ADP-ribose) polymerase-1 (PARP-1) is known to regulate transcription through histone modification. Recent studies have suggested that PARP-1 positively regulates the formation of long-term memory (LTM); however, the roles of PARP-1 in memory processes, especially processes after retrieval, remain unknown. Results Here, we show critical roles ...

  15. The XRCC1 phosphate-binding pocket binds poly (ADP-ribose) and is required for XRCC1 function.

    Science.gov (United States)

    Breslin, Claire; Hornyak, Peter; Ridley, Andrew; Rulten, Stuart L; Hanzlikova, Hana; Oliver, Antony W; Caldecott, Keith W

    2015-08-18

    Poly (ADP-ribose) is synthesized at DNA single-strand breaks and can promote the recruitment of the scaffold protein, XRCC1. However, the mechanism and importance of this process has been challenged. To address this issue, we have characterized the mechanism of poly (ADP-ribose) binding by XRCC1 and examined its importance for XRCC1 function. We show that the phosphate-binding pocket in the central BRCT1 domain of XRCC1 is required for selective binding to poly (ADP-ribose) at low levels of ADP-ribosylation, and promotes interaction with cellular PARP1. We also show that the phosphate-binding pocket is required for EGFP-XRCC1 accumulation at DNA damage induced by UVA laser, H2O2, and at sites of sub-nuclear PCNA foci, suggesting that poly (ADP-ribose) promotes XRCC1 recruitment both at single-strand breaks globally across the genome and at sites of DNA replication stress. Finally, we show that the phosphate-binding pocket is required following DNA damage for XRCC1-dependent acceleration of DNA single-strand break repair, DNA base excision repair, and cell survival. These data support the hypothesis that poly (ADP-ribose) synthesis promotes XRCC1 recruitment at DNA damage sites and is important for XRCC1 function. PMID:26130715

  16. The XRCC1 phosphate-binding pocket binds poly (ADP-ribose) and is required for XRCC1 function

    Science.gov (United States)

    Breslin, Claire; Hornyak, Peter; Ridley, Andrew; Rulten, Stuart L.; Hanzlikova, Hana; Oliver, Antony W.; Caldecott, Keith W.

    2015-01-01

    Poly (ADP-ribose) is synthesized at DNA single-strand breaks and can promote the recruitment of the scaffold protein, XRCC1. However, the mechanism and importance of this process has been challenged. To address this issue, we have characterized the mechanism of poly (ADP-ribose) binding by XRCC1 and examined its importance for XRCC1 function. We show that the phosphate-binding pocket in the central BRCT1 domain of XRCC1 is required for selective binding to poly (ADP-ribose) at low levels of ADP-ribosylation, and promotes interaction with cellular PARP1. We also show that the phosphate-binding pocket is required for EGFP-XRCC1 accumulation at DNA damage induced by UVA laser, H2O2, and at sites of sub-nuclear PCNA foci, suggesting that poly (ADP-ribose) promotes XRCC1 recruitment both at single-strand breaks globally across the genome and at sites of DNA replication stress. Finally, we show that the phosphate-binding pocket is required following DNA damage for XRCC1-dependent acceleration of DNA single-strand break repair, DNA base excision repair, and cell survival. These data support the hypothesis that poly (ADP-ribose) synthesis promotes XRCC1 recruitment at DNA damage sites and is important for XRCC1 function. PMID:26130715

  17. PARP1 Inhibitors: antitumor drug design

    OpenAIRE

    MALYUCHENKO N.V.; Kotova, E. Yu.; Kulaeva, O. I.; Kirpichnikov, M P; STUDITSKIY V.M.

    2015-01-01

    The poly (ADP-ribose) polymerase 1 (PARP1) enzyme is one of the promising molecular targets for the discovery of antitumor drugs. PARP1 is a common nuclear protein (1–2 million molecules per cell) serving as a “sensor” for DNA strand breaks. Increased PARP1 expression is sometimes observed in melanomas, breast cancer, lung cancer, and other neoplastic diseases. The PARP1 expression level is a prognostic indicator and is associated with a poor survival prognosis. There is evidence that high PA...

  18. PARP1 INHIBITORS: ANTITUMOR DRUG DESIGN

    OpenAIRE

    MALYUCHENKO N.V.; KOTOVA E. YU.; Kulaeva, O. I.; Kirpichnikov, M P; STUDITSKIY V.M.

    2015-01-01

    The poly (ADP-ribose) polymerase 1 (PARP1) enzyme is one of the promising molecular targets for the discovery of antitumor drugs. PARP1 is a common nuclear protein (1-2 million molecules per cell) serving as a “sensor” for DNA strand breaks. Increased PARP1 expression is sometimes observed in melanomas, breast cancer, lung cancer, and other neoplastic diseases. The PARP1 expression level is a prognostic indicator and is associated with a poor survival prognosis. There is evidence that high PA...

  19. Correlation Between PARP-1 Immunoreactivity and Cytomorphological Features of Parthanatos, a Specific Cellular Death in Breast Cancer Cells

    OpenAIRE

    Donizy, P.; Halon, A.; Surowiak, P.; Pietrzyk, G.; C. Kozyra; Matkowski, R.

    2013-01-01

    In parthanatos, a PARP-1 (poly (ADP-ribose) polymerase 1)-mediated cell death, dissipation of mitochondrial membrane potential, large-scale DNA fragmentation and chromatin condensation were observed. In contrast to apoptosis, it does not cause apoptotic bodies formation. Although PARP-1-mediated cell death presents loss of membrane integrity similar to necrosis, it does not induce cell swelling. The purpose of the study was to correlate the immunohistochemical parameters of PARP-1 reactivity ...

  20. Mitochondrial Localization of PARP-1 Requires Interaction with Mitofilin and Is Involved in the Maintenance of Mitochondrial DNA Integrity*

    OpenAIRE

    Rossi, Marianna N.; Carbone, Mariarosaria; Mostocotto, Cassandra; Mancone, Carmine; Tripodi, Marco; Maione, Rossella; Amati, Paolo

    2009-01-01

    Poly(ADP-ribose)polymerase-1 (PARP-1) is a predominantly nuclear enzyme that exerts numerous functions in cellular physiology and pathology, from maintenance of DNA stability to transcriptional regulation. Through a proteomic analysis of PARP-1 co-immunoprecipitation complexes, we identified Mitofilin, a mitochondrial protein, as a new PARP-1 interactor. This result prompted us to further investigate the presence and the role of the enzyme in mitochondria. Using laser confocal microscopy and ...

  1. The Histone Methyltransferase SMYD2 Methylates PARP1 and Promotes Poly(ADP-ribosyl)ation Activity in Cancer Cells

    OpenAIRE

    Lianhua Piao; Daechun Kang; Takehiro Suzuki; Akiko Masuda; Naoshi Dohmae; Yusuke Nakamura; Ryuji Hamamoto

    2014-01-01

    Poly(ADP-ribose) polymerase-1 (PARP1) catalyzes the poly(ADP-ribosyl)ation of protein acceptors using NAD+ as the substrate is now considered as an important target for development of anticancer therapy. PARP1 is known to be post-translationally modified in various ways including phosphorylation and ubiquitination, but the physiological role of PARP1 methylation is not well understood. Herein we demonstrated that the histone methyltransferase SMYD2, which plays critical roles in human carcino...

  2. Genome-Wide Profiling of PARP1 Reveals an Interplay with Gene Regulatory Regions and DNA Methylation

    OpenAIRE

    Nalabothula, Narasimharao; Al-jumaily, Taha; Eteleeb, Abdallah M.; Flight, Robert M; Xiaorong, Shao; Moseley, Hunter; Rouchka, Eric C; Fondufe-Mittendorf, Yvonne N.

    2015-01-01

    Poly (ADP-ribose) polymerase-1 (PARP1) is a nuclear enzyme involved in DNA repair, chromatin remodeling and gene expression. PARP1 interactions with chromatin architectural multi-protein complexes (i.e. nucleosomes) alter chromatin structure resulting in changes in gene expression. Chromatin structure impacts gene regulatory processes including transcription, splicing, DNA repair, replication and recombination. It is important to delineate whether PARP1 randomly associates with nucleosomes or...

  3. The Histone Methyltransferase SMYD2 Methylates PARP1 and Promotes Poly(ADP-ribosyl)ation Activity in Cancer Cells12

    OpenAIRE

    Piao, Lianhua; Kang, Daechun; Suzuki, Takehiro; Masuda, Akiko; Dohmae, Naoshi; Nakamura, Yusuke; Hamamoto, Ryuji

    2014-01-01

    Poly(ADP-ribose) polymerase-1 (PARP1) catalyzes the poly(ADP-ribosyl)ation of protein acceptors using NAD+ as the substrate is now considered as an important target for development of anticancer therapy. PARP1 is known to be post-translationally modified in various ways including phosphorylation and ubiquitination, but the physiological role of PARP1 methylation is not well understood. Herein we demonstrated that the histone methyltransferase SMYD2, which plays critical roles in human carcino...

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

    OpenAIRE

    Godon, Camille; Cordelières, Fabrice P.; Biard, Denis; Giocanti, Nicole; Mégnin-Chanet, Frédérique; Hall, Janet; Favaudon, Vincent

    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, isogenic HeLa cells stably silenced or not for poly(ADP-ribose) polymerase-1 (PARP-1) (PARP-1KD) or XRCC1 (XRCC1KD). 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...

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

    OpenAIRE

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

    2013-01-01

    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 hypo...

  6. PARP1 activation/expression modulates regional-specific neuronal and glial responses to seizure in a hemodynamic-independent manner

    OpenAIRE

    Kim, J-E; Kim, Y-J; Kim, J.Y.; Kang, T-C

    2014-01-01

    Poly(ADP-ribose) polymerase-1 (PARP1) plays a regulatory role in apoptosis, necrosis and other cellular processes after injury. Status epilepticus (SE) induces neuronal and astroglial death that show regional-specific patterns in the rat hippocampus and piriform cortex (PC). Thus, we investigated whether PARP1 regulates the differential neuronal/glial responses to pilocarpine (PILO)-induced SE in the distinct brain regions. In the present study, both CA1 and CA3 neurons showed PARP1 hyperacti...

  7. Radiation-induced DNA breaks detected by immuno labelling of poly(ADP-ribose) in CHO cells. Standardization by pulsed-field gel electrophoresis

    International Nuclear Information System (INIS)

    The poly (ADP-ribose) polymerase is an ubiquitous nuclear protein capable of binding specifically to DNA strand breaks. It synthesizes ADP-ribose polymers proportionally to DNA breaks. The actual method of reference to determine DNA double strand breaks is pulsed-field gel electrophoresis, but this requires many cells. It thus appeared of interest to use poly (ADP-ribos)ylation to follow and estimate γ-ray-induced DNA fragmentation at the level of isolated cells after γ-irradiation in chinese hamster ovary cells (CHO-K1). The results obtained by the immuno-labelling technique of ADP-ribose polymers were compared to those obtained by pulsed-field gel electrophoresis. They show that poly (ADP-ribos)ylation reflects the occurrence of radiation-induced DNA strand breaks. A clear relationship exists between the amount of ADP-ribose polymers detected and DNA double strand breaks after γ-irradiation. (authors)

  8. Nanosecond pulsed electric fields induce poly(ADP-ribose) formation and non-apoptotic cell death in HeLa S3 cells

    Energy Technology Data Exchange (ETDEWEB)

    Morotomi-Yano, Keiko; Akiyama, Hidenori [Institute of Pulsed Power Science, Kumamoto University, Kumamoto 860-8555 (Japan); Yano, Ken-ichi, E-mail: yanoken@kumamoto-u.ac.jp [Priority Organization for Innovation and Excellence, Kumamoto University, Kumamoto 860-8555 (Japan)

    2013-08-30

    Highlights: •Nanosecond pulsed electric field (nsPEF) is a new and unique means for life sciences. •Apoptosis was induced by nsPEF exposure in Jurkat cells. •No signs of apoptosis were detected in HeLa S3 cells exposed to nsPEFs. •Formation of poly(ADP-ribose) was induced in nsPEF-exposed HeLa S3 cells. •Two distinct modes of cell death were activated by nsPEF in a cell-dependent manner. -- Abstract: Nanosecond pulsed electric fields (nsPEFs) have recently gained attention as effective cancer therapy owing to their potency for cell death induction. Previous studies have shown that apoptosis is a predominant mode of nsPEF-induced cell death in several cell lines, such as Jurkat cells. In this study, we analyzed molecular mechanisms for cell death induced by nsPEFs. When nsPEFs were applied to Jurkat cells, apoptosis was readily induced. Next, we used HeLa S3 cells and analyzed apoptotic events. Contrary to our expectation, nsPEF-exposed HeLa S3 cells exhibited no molecular signs of apoptosis execution. Instead, nsPEFs induced the formation of poly(ADP-ribose) (PAR), a hallmark of necrosis. PAR formation occurred concurrently with a decrease in cell viability, supporting implications of nsPEF-induced PAR formation for cell death. Necrotic PAR formation is known to be catalyzed by poly(ADP-ribose) polymerase-1 (PARP-1), and PARP-1 in apoptotic cells is inactivated by caspase-mediated proteolysis. Consistently, we observed intact and cleaved forms of PARP-1 in nsPEF-exposed and UV-irradiated cells, respectively. Taken together, nsPEFs induce two distinct modes of cell death in a cell type-specific manner, and HeLa S3 cells show PAR-associated non-apoptotic cell death in response to nsPEFs.

  9. BCL2 suppresses PARP1 function and non-apoptotic cell death

    OpenAIRE

    Dutta, Chaitali; Day, Tovah; Kopp, Nadja; van Bodegom, Diederik; Davids, Matthew S.; Ryan, Jeremy; Bird, Liat; Kommajosyula, Naveen; Weigert, Oliver; Yoda, Akinori; Fung, Hua; Brown, Jennifer R; Shapiro, Geoffrey I.; Letai, Anthony; Weinstock, David M.

    2012-01-01

    BCL2 suppresses apoptosis by binding the BH3 domain of pro-apoptotic factors and thereby regulating outer mitochondrial membrane permeabilization. Many tumor types, including B-cell lymphomas and chronic lymphocytic leukemia, are dependent on BCL2 for survival, but become resistant to apoptosis after treatment. Here we identified a direct interaction between the anti-apoptotic protein BCL2 and the enzyme poly(ADP) ribose polymerase 1 (PARP1), which suppresses PARP1 enzymatic activity and inhi...

  10. Association between the PARP1 Val762Ala Polymorphism and Cancer Risk: Evidence from 43 Studies

    OpenAIRE

    Hua, Rui-Xi; Li, He-Ping; Liang, Yan-bing; Zhu, Jin-Hong; Zhang, Bing; Ye, Sheng; Dai, Qiang-Sheng; Xiong, Shi-Qiu; Gu, Yong; Sun, Xiang-Zhou

    2014-01-01

    Background Poly (ADP-ribose) polymerase-1 (PARP-1) plays critical roles in the detection and repair of damaged DNA, as well as cell proliferation and death. Numerous studies have examined the associations between PARP1 Val762Ala (rs1136410 T>C) polymorphism and cancer susceptibility; nevertheless, the findings from different research groups remain controversial. Methods We searched literatures from MEDLINE, EMBASE and CBM pertaining to such associations, and then calculated pooled odds ratio ...

  11. PARP1 genomics: chromatin immunoprecipitation approach using anti-PARP1 antibody (ChIP and ChIP-seq)

    OpenAIRE

    Lodhi, Niraj; Tulin, Alexei V.

    2011-01-01

    Poly(ADP-ribose) polymerase1 (PARP1) is a global regulator of different cellular mechanisms, ranging from DNA damage repair to control of gene expression. Since PARP1 protein and pADPr have been shown to persist in chromatin through cell cycle, they may both act as epigenetic markers. However, it is not known how many loci are occupied by PARP1 protein during mitosis genome-wide. To reveal the genome-wide PARP1 binding sites, we used the ChIP-seq approach, an emerging technique to study genom...

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

    OpenAIRE

    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.

    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...

  13. PARP-1 ensures regulation of replication fork progression by homologous recombination on damaged DNA

    OpenAIRE

    Sugimura, Kazuto; Takebayashi, Shin-ichiro; Taguchi, Hiroshi; Takeda, Shunichi; Okumura, Katsuzumi

    2008-01-01

    Poly-ADP ribose polymerase 1 (PARP-1) is activated by DNA damage and has been implicated in the repair of single-strand breaks (SSBs). Involvement of PARP-1 in other DNA damage responses remains controversial. In this study, we show that PARP-1 is required for replication fork slowing on damaged DNA. Fork progression in PARP-1 −/− DT40 cells is not slowed down even in the presence of DNA damage induced by the topoisomerase I inhibitor camptothecin (CPT). Mammalian cells treated with a PARP in...

  14. Biological and clinical significance of PARP1 protein expression in breast cancer

    OpenAIRE

    Green, Andrew R.; Caracappa, Daniela; Benhasouna, Ahmed A.; Alshareeda, Alaa; Nolan, Christopher C.; Macmillan, R. Douglas; Madhusudan, Srinivasan; Ellis, Ian O; Rakha, Emad A

    2014-01-01

    Poly(ADP-ribose) polymerase-1 (PARP1) is a key facilitator of DNA repair. PARP inhibitors have gained recent attention as promising therapeutic agents for the treatment of solid tumours including breast cancer (BC). However, the biological and clinical significance of PARP1 expression in BC and its role in DNA-damage response (DDR) remain to be defined. We investigated the expression of PARP1 expression, cleaved (PARP1c) and non-cleaved (PAR1nc) forms, in a large and well-characterised cohort...

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

    OpenAIRE

    Ji-Eun Kim

    2015-01-01

    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). Therefo...

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

    OpenAIRE

    Shang, Fenqing; Zhang, Jiao; Li, Zhao; Zhang, Jin; Yin, Yanjun; Wang, Yaqiong; Marin, Traci L.; Gongol, Brendan; Xiao, Han; Zhang, You-Yi; Chen, Zhen; Shyy, John Y-J; Lei, Ting

    2016-01-01

    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 pro...

  17. Recent advances in the Okamoto model: the CD38-cyclic ADP-ribose signal system and the regenerating gene protein (Reg)-Reg receptor system in beta-cells.

    Science.gov (United States)

    Okamoto, Hiroshi; Takasawa, Shin

    2002-12-01

    Twenty years ago, we first proposed our hypothesis on beta-cell damage and its prevention (the Okamoto model), according to which poly(ADP-ribose) synthetase/polymerase (PARP) activation is critically involved in the consumption of NAD(+), leading to energy depletion and cell death by necrosis. Recently, the model was reconfirmed by results using PARP knockout mice and has been recognized as providing the basis for necrotic death of various cells and tissues. Based on the model, we proposed two signal systems in beta-cells: one is the CD38-cyclic ADP-ribose (cADPR) signal system for insulin secretion, and the other is the regenerating gene protein (Reg)-Reg receptor system for beta-cell regeneration. The physiological and pathological significance of the two signal systems in a variety of cells and tissues as well as in pancreatic beta-cells has recently been recognized. Here, we describe the Okamoto model and its descendents, the CD38-cADPR signal system and the Reg-Reg receptor system, focusing on recent advances and how their significance came to light. Because PARP is involved in Reg gene transcription to induce beta-cell regeneration, and the PARP activation reduces the cellular NAD(+) to decrease the formation of cADPR (a second messenger for insulin secretion) and further to cause necrotic beta-cell death, PARP and its inhibitors have key roles in the induction of beta-cell regeneration, the maintenance of insulin secretion, and the prevention of beta-cell death. PMID:12475791

  18. Correlation between the expression of PTEN and anti-tumor activity of PARP inhibitor and radiation in cultured endometrial carcinoma cells

    International Nuclear Information System (INIS)

    PTEN inactivation is the most frequent genetic aberration in endometrial cancer. One of the phosphatase-independent roles of PTEN is associated with homologous recombination (HR) in the nucleus. Poly (ADP-ribose) polymerase (PARP) plays key roles in the repair of DNA single-strand breaks, and a PARP inhibitor induces synthetic lethality in cancer cells with HR deficiency. Radiation also causes double strand break, which is repaired through HR. We examined the anti-tumor activity of PARP inhibitor and radiation on endometrial cancer cell lines with different PTEN status. Here we introduce this work, which was recently published (Aki Miyasaka, Katsutoshi Oda, Yuji Ikeda et al. Anti-tumor activity of olaparib, a poly (ADP-ribose) polymerase (PARP) inhibitor, in cultured endometrial carcinoma cell line BMC Cancer 2014, 14: 179). (author)

  19. PARP-1 expression in breast cancer including BRCA1-associated, triple negative and basal-like tumors: possible implications for PARP-1 inhibitor therapy

    OpenAIRE

    Domagala, Pawel; Huzarski, Tomasz; Lubinski, Jan; Gugala, Karol; Domagala, Wenancjusz

    2011-01-01

    Abstract Despite ongoing trials of PARP inhibitors in the treatment of breast cancer (BC), the extent of poly(ADP-ribose)polymerase-1 (PARP-1) protein expression in BCs, which may influence treatment results, is not known. The purpose of this report is to assess expression of PARP-1 in BC including BRCA1-associated, triple negative (TN), and basal-like tumors. Immunohistochemistry with a PARP-1 antibody on tissue microarrays from 130 BRCA1-associated and 594 BRCA1-non-related BCs w...

  20. DNA-dependent SUMO modification of PARP-1 ☆

    OpenAIRE

    Zilio, Nicola; Williamson, Chris T.; Eustermann, Sebastian; Shah, Rajvee; West, Stephen C.; Neuhaus, David; Ulrich, Helle D.

    2013-01-01

    Poly(ADP-ribose) polymerase 1 (PARP-1) plays an important role in DNA repair, but also contributes to other aspects of nucleic acid metabolism, such as transcriptional regulation. Modification of PARP-1 with the small ubiquitin-related modifier (SUMO) affects its function as a transcriptional co-activator of hypoxia-responsive genes and promotes induction of the heat shock-induced HSP70.1 promoter. We now report that PARP-1 sumoylation is strongly influenced by DNA. Consistent with a function...

  1. Protective Effects of PARP-1 Knockout on Dyslipidemia-Induced Autonomic and Vascular Dysfunction in ApoE−/− Mice: Effects on eNOS and Oxidative Stress

    OpenAIRE

    Hans, Chetan P.; Feng, Yumei; Naura, Amarjit S; Zerfaoui, Mourad; Rezk, Bashir M.; Xia, Huijing; Kaye, Alan D.; Matrougui, Khalid; Lazartigues, Eric; Boulares, A Hamid

    2009-01-01

    The aims of this study were to investigate the role of poly(ADP-ribose) polymerase (PARP)-1 in dyslipidemia-associated vascular dysfunction as well as autonomic nervous system dysregulation. Apolipoprotein (ApoE) −/− mice fed a high-fat diet were used as a model of atherosclerosis. Vascular and autonomic functions were measured in conscious mice using telemetry. The study revealed that PARP-1 plays an important role in dyslipidemia-associated vascular and autonomic dysfunction. Inhibition of ...

  2. YY1-Binding Sites Provide Central Switch Functions in the PARP-1 Gene Expression Network.

    OpenAIRE

    Doetsch, Martina; Gluch, Angela; Poznanović, Goran; Bode, Juergen; Vidaković, Melita

    2012-01-01

    Evidence is presented for the involvement of the interplay between transcription factor Yin Yang 1 (YY1) and poly(ADP-ribose) polymerase-1 (PARP-1) in the regulation of mouse PARP-1 gene (muPARP-1) promoter activity. We identified potential YY1 binding motifs (BM) at seven positions in the muPARP-1 core-promoter (−574/+200). Binding of YY1 was observed by the electrophoretic supershift assay using anti-YY1 antibody and linearized or supercoiled forms of plasmids bearing the core promoter, as ...

  3. PARP-1 Controls Immunosuppressive Function of Regulatory T Cells by Destabilizing Foxp3

    OpenAIRE

    Zhang, Pin; Maruyama, Takashi; Konkel, Joanne E.; Abbatiello, Brittany; Zamarron, Brian; Wang, Zhao-Qi; Chen, Wanjun

    2013-01-01

    Poly (ADP-ribose) polymerase-1 (PARP-1) is a nuclear enzyme and transcription factor that is involved in inflammatory response, but its role in T cell response remains largely unknown. We show here that PARP-1 regulates the suppressive function of CD4+CD25+Foxp3+ regulatory T cells (Tregs). Specifically, Tregs in mice with a null mutation of the PARP-1 gene (PARP-1–/–) showed significantly stronger suppressive activity than did wild-type Tregs in culture. We elucidate that this enhanced suppr...

  4. Quantitative site-specific ADP-ribosylation profiling of DNA-dependent PARPs.

    Science.gov (United States)

    Gagné, Jean-Philippe; Ethier, Chantal; Defoy, Daniel; Bourassa, Sylvie; Langelier, Marie-France; Riccio, Amanda A; Pascal, John M; Moon, Kyung-Mee; Foster, Leonard J; Ning, Zhibin; Figeys, Daniel; Droit, Arnaud; Poirier, Guy G

    2015-06-01

    An important feature of poly(ADP-ribose) polymerases (PARPs) is their ability to readily undergo automodification upon activation. Although a growing number of substrates were found to be poly(ADP-ribosyl)ated, including histones and several DNA damage response factors, PARPs themselves are still considered as the main acceptors of poly(ADP-ribose). By monitoring spectral counts of specific hydroxamic acid signatures generated after the conversion of the ADP-ribose modification onto peptides by hydroxylamine hydrolysis, we undertook a thorough mass spectrometry mapping of the glutamate and aspartate ADP-ribosylation sites onto automodified PARP-1, PARP-2 and PARP-3. Thousands of hydroxamic acid-conjugated peptides were identified with high confidence and ranked based on their spectral count. This semi-quantitative approach allowed us to locate the preferentially targeted residues in DNA-dependent PARPs. In contrast to what has been reported in the literature, automodification of PARP-1 is not predominantly targeted towards its BRCT domain. Our results show that interdomain linker regions that connect the BRCT to the WGR module and the WGR to the PRD domain undergo prominent ADP-ribosylation during PARP-1 automodification. We also found that PARP-1 efficiently automodifies the D-loop structure within its own catalytic fold. Interestingly, additional major ADP-ribosylation sites were identified in functional domains of PARP-1, including all three zinc fingers. Similar to PARP-1, specific residues located within the catalytic sites of PARP-2 and PARP-3 are major targets of automodification following their DNA-dependent activation. Together our results suggest that poly(ADP-ribosyl)ation hot spots make a dominant contribution to the overall automodification process. PMID:25800440

  5. Structural studies of the PARP-1 BRCT domain

    Directory of Open Access Journals (Sweden)

    Gabel Scott A

    2011-10-01

    Full Text Available Abstract Background Poly(ADP-ribose polymerase-1 (PARP-1 is one of the first proteins localized to foci of DNA damage. Upon activation by encountering nicked DNA, the PARP-1 mediated trans-poly(ADP-ribosylation of DNA binding proteins occurs, facilitating access and accumulation of DNA repair factors. PARP-1 also auto-(ADP-ribosylates its central BRCT-containing domain forming part of an interaction site for the DNA repair scaffolding protein X-ray cross complementing group 1 protein (XRCC1. The co-localization of XRCC1, as well as bound DNA repair factors, to sites of DNA damage is important for cell survival and genomic integrity. Results Here we present the solution structure and biophysical characterization of the BRCT domain of rat PARP-1. The PARP-1 BRCT domain has the globular α/β fold characteristic of BRCT domains and has a thermal melting transition of 43.0°C. In contrast to a previous characterization of this domain, we demonstrate that it is monomeric in solution using both gel-filtration chromatography and small-angle X-ray scattering. Additionally, we report that the first BRCT domain of XRCC1 does not interact significantly with the PARP-1 BRCT domain in the absence of ADP-ribosylation. Moreover, none of the interactions with other longer PARP-1 constructs which previously had been demonstrated in a pull-down assay of mammalian cell extracts were detected. Conclusions The PARP-1 BRCT domain has the conserved BRCT fold that is known to be an important protein:protein interaction module in DNA repair and cell signalling pathways. Data indicating no significant protein:protein interactions between PARP-1 and XRCC1 likely results from the absence of poly(ADP-ribose in one or both binding partners, and further implicates a poly(ADP-ribose-dependent mechanism for localization of XRCC1 to sites of DNA damage.

  6. Acceptor proteins for poly(ADP-ribose) in irradiated normal human and ataxia telangiectasia (AT) fibroblasts

    International Nuclear Information System (INIS)

    Poly(ADP-ribose) polymerase activity is stimulated by DNA strand breaks and may participate in DNA repair. Since treatment of cells with DNA damaging agents stimulated the poly(ADP-ribosylation) of a specific set of proteins, the authors have analyzed the acceptors in irradiated human fibroblasts from normal individuals and from patients with AT, a disease associated with a hypersensitivity to ionizing radiation. Cells were permeabilized and incubated with /sup 32/P-NAD, proteins were separated by polyacrylamide gel electrophoresis, and the poly (ADP-ribose) acceptors were detected by autoradiography. In all four strains, the major acceptor was the 116 kd auto-modified polymerase, while other prominent radioactive bands were at 2, 45, and 60 kd. Labeling of these bands was increased following irradiation of the cells with 3-30 Gy. Of interest was the detection of a poly (ADP-ribosylated) protein at 19 kd in the two normal strains but not in either AT strain. The results suggest that a defect in the ADP-ribosylation of the 19 kd protein is associated with AT and possible with the hypersensitivity of AT cells to ionizing radiation

  7. Low concentration of arsenite exacerbates UVR-induced DNA strand breaks by inhibiting PARP-1 activity

    OpenAIRE

    Qin, Xu-Jun; Hudson, Laurie G.; Liu, Wenlan; Timmins, Graham S.; Liu, Ke Jian

    2008-01-01

    Epidemiological studies have associated arsenic exposure with many types of human cancers. Arsenic has also been shown to act as a co-carcinogen even at low concentrations. However, the precise mechanism of its co-carcinogenic action is unknown. Recent studies indicate that arsenic can interfere with DNA repair processes. Poly (ADP-ribose) polymerase (PARP)-1 is a zinc-finger DNA repair protein, which can promptly sense DNA strand breaks and initiate DNA repair pathways. In the present study,...

  8. Characterization of the interactions of PARP-1 with UV-damaged DNA in vivo and in vitro

    OpenAIRE

    Nupur K. Purohit; Mihaela Robu; Rashmi G. Shah; Geacintov, Nicholas E.; Shah, Girish M.

    2016-01-01

    The existing methodologies for studying robust responses of poly (ADP-ribose) polymerase-1 (PARP-1) to DNA damage with strand breaks are often not suitable for examining its subtle responses to altered DNA without strand breaks, such as UV-damaged DNA. Here we describe two novel assays with which we characterized the interaction of PARP-1 with UV-damaged DNA in vivo and in vitro. Using an in situ fractionation technique to selectively remove free PARP-1 while retaining the DNA-bound PARP-1, w...

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

    OpenAIRE

    Park, See-Hyoung; JANG, KYU YUN; Kim, Min Jae; 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...

  10. 3′-5′ Phosphoadenosine phosphate is an inhibitor of PARP-1 and a potential mediator of the lithium-dependent inhibition of PARP-1 in vivo

    OpenAIRE

    Toledano, Elie; Ogryzko, Vasily; Danchin, Antoine; Ladant, Daniel; Mechold, Undine

    2012-01-01

    pAp (3′-5′ phosphoadenosine phosphate) is a by-product of sulfur and lipid metabolism and has been shown to have strong inhibitory properties on RNA catabolism. In the present paper we report a new target of pAp, PARP-1 [poly(ADP-ribose) polymerase 1], a key enzyme in the detection of DNA single-strand breaks. We show that pAp can interact with PARP-1 and inhibit its poly(ADP-ribosyl)ation activity. In vitro, inhibition of PARP-1 was detectable at micromolar concentrations of pAp and altered ...

  11. PARP-1 inhibition influences the oxidative stress response of the human lens

    OpenAIRE

    Smith, Andrew J.O.; Simon S.R. Ball; Bowater, Richard P.; I. Michael Wormstone

    2016-01-01

    Poly(ADP-ribose) polymerase-1 (PARP-1) is best characterised for its involvement in DNA repair. PARP-1 activity is also linked to cell fate, confounding its roles in maintaining genome integrity. The current study assessed the functional roles of PARP-1 within human lens cells in response to oxidative stress. The human lens epithelial cell line FHL124 and whole human lens cultures were used as experimental systems. Hydrogen peroxide (H2O2) was employed to induce oxidative stress and cell deat...

  12. PARP1-Driven Apoptosis in Chronic Lymphocytic Leukemia

    OpenAIRE

    2014-01-01

    Chronic lymphocytic leukemia (CLL) is considered a malignancy resulting from defects in apoptosis. For this reason, targeting apoptotic pathways in CLL may be valuable for its management. Poly [ADP-ribose] polymerase 1 (PARP1) is the main member of a family of nuclear enzymes that act as DNA damage sensors. Through binding on DNA damaged structures, PARP1 recruits repair enzymes and serves as a survival factor, but if the damage is severe enough, its action may lead the cell to apoptosis thro...

  13. Proximal ADP-ribose Hydrolysis in Trypanosomatids is Catalyzed by a Macrodomain.

    Science.gov (United States)

    Haikarainen, Teemu; Lehtiö, Lari

    2016-01-01

    ADP-ribosylation is a ubiquitous protein modification utilized by both prokaryotes and eukaryotes for several cellular functions, such as DNA repair, proliferation, and cell signaling. Higher eukaryotes, such as humans, utilize various enzymes to reverse the modification and to regulate ADP-ribose dependent signaling. In contrast, some lower eukaryotes, including trypanosomatids, lack many of these enzymes and therefore have a much more simplified ADP-ribose metabolism. Here we identified and characterized ADP-ribose hydrolases from Trypanosoma brucei and Trypanosoma cruzi, which are homologous to human O-acetyl-ADP-ribose deacetylases MacroD1 and MacroD2. The enzymes are capable for hydrolysis of protein linked ADP-ribose and a product of sirtuin-mediated lysine deacetylation, O-acetyl-ADP-ribose. Crystal structures of the trypanosomatid macrodomains revealed a conserved catalytic site with distinct differences to human MacroD1 and MacroD2. PMID:27064071

  14. Binding to WGR Domain by Salidroside Activates PARP1 and Protects Hematopoietic Stem Cells from Oxidative Stress

    OpenAIRE

    Li, Xue; Erden, Ozlem; Li, Liang; Ye, Qidong; Wilson, Andrew; Du, Wei

    2014-01-01

    Aims: A component of the base excision repair pathway, poly(ADP-ribose) polymerase-1 (PARP1) functions in multiple cellular processes, including DNA repair and programmed cell death. We previously showed that Salidroside, a phenylpropanoid glycoside isolated from medicinal plants, prevented the loss of hematopoietic stem cells (HSCs) in native mice and rescued HSCs repopulating in transplanted recipients under oxidative stress. The aim of this study was to investigate the mechanism by which P...

  15. Blocking c-Met-mediated PARP1 phosphorylation enhances anti-tumor effects of PARP inhibitors.

    Science.gov (United States)

    Du, Yi; Yamaguchi, Hirohito; Wei, Yongkun; Hsu, Jennifer L; Wang, Hung-Ling; Hsu, Yi-Hsin; Lin, Wan-Chi; Yu, Wen-Hsuan; Leonard, Paul G; Lee, Gilbert R; Chen, Mei-Kuang; Nakai, Katsuya; Hsu, Ming-Chuan; Chen, Chun-Te; Sun, Ye; Wu, Yun; Chang, Wei-Chao; Huang, Wen-Chien; Liu, Chien-Liang; Chang, Yuan-Ching; Chen, Chung-Hsuan; Park, Morag; Jones, Philip; Hortobagyi, Gabriel N; Hung, Mien-Chie

    2016-02-01

    Poly (ADP-ribose) polymerase (PARP) inhibitors have emerged as promising therapeutics for many diseases, including cancer, in clinical trials. One PARP inhibitor, olaparib (Lynparza, AstraZeneca), was recently approved by the FDA to treat ovarian cancer with mutations in BRCA genes. BRCA1 and BRCA2 have essential roles in repairing DNA double-strand breaks, and a deficiency of BRCA proteins sensitizes cancer cells to PARP inhibition. Here we show that the receptor tyrosine kinase c-Met associates with and phosphorylates PARP1 at Tyr907 (PARP1 pTyr907 or pY907). PARP1 pY907 increases PARP1 enzymatic activity and reduces binding to a PARP inhibitor, thereby rendering cancer cells resistant to PARP inhibition. The combination of c-Met and PARP1 inhibitors synergized to suppress the growth of breast cancer cells in vitro and xenograft tumor models, and we observed similar synergistic effects in a lung cancer xenograft tumor model. These results suggest that the abundance of PARP1 pY907 may predict tumor resistance to PARP inhibitors, and that treatment with a combination of c-Met and PARP inhibitors may benefit patients whose tumors show high c-Met expression and who do not respond to PARP inhibition alone. PMID:26779812

  16. Basal Activity of a PARP1-NuA4 Complex Varies Dramatically across Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    Kristin A. Krukenberg

    2014-09-01

    Full Text Available Poly(ADP-ribose polymerases (PARPs catalyze poly(ADP-ribose addition onto proteins, an important posttranslational modification involved in transcription, DNA damage repair, and stem cell identity. Previous studies established the activation of PARP1 in response to DNA damage, but little is known about PARP1 regulation outside of DNA repair. We developed an assay for measuring PARP activity in cell lysates and found that the basal activity of PARP1 was highly variable across breast cancer cell lines, independent of DNA damage. Sucrose gradient fractionation demonstrated that PARP1 existed in at least three biochemically distinct states in both high- and low-activity lines. A discovered complex containing the NuA4 chromatin-remodeling complex and PARP1 was responsible for high basal PARP1 activity, and NuA4 subunits were required for this activity. These findings present a pathway for PARP1 activation and a direct link between PARP1 and chromatin remodeling outside of the DNA damage response.

  17. Carcinogen-inflicted DNA damage causes a dramatic increase in the degradation of chromatin-bound poly(ADP-ribose) in mammalian cells

    International Nuclear Information System (INIS)

    A characteristic response of eukaryotic cells to treatment with carcinogens is de novo poly(ADP-ribosylation) of chromatin proteins, a reaction which acts to modulate subsequent DNA excision repair by a hitherto unidentified molecular mechanism. DNA strand breaks represent the molecular signal which activates the chromatin enzyme poly(ADP-ribose) polymerase and thus stimulates poly(ADP-ribose) biosynthesis. They have now observed that carcinogen-inflicted DNA damage may also cause a more than 600-fold stimulation of the degradation of protein-bound poly(ADP-ribose) in chromatin of rat hepatocytes in primary culture. As a consequence, the metabolic half-life of the polymer decreases from 7.7 h in undamaged control cells to 5.5 min and 2.5 min following damage of cells with 45 and 150 J/m2 of UV light of 254 nm, respectively. Similarly, damage of hepatocellular DNA inflicted with either 20, 50 or 200 μM N-methyl-N'-nitro-N-nitrosoguanidine, a monofunctional alkylating agent, caused a dramatic decrease in the polymer half-life to 5.1 min, 2.3 min, and 41 sec, respectively. Therefore, their results suggest that the dynamic removal of polymeric ADP-ribose residues from their chromatin acceptors represents an obligatory postincisional event in DNA excision repair of mammalian cells

  18. 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

    (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......Impaired DNA damage response pathways may create vulnerabilities of cancer cells that can be exploited therapeutically. One such selective vulnerability is the sensitivity of BRCA1- or BRCA2-defective tumors (hence defective in DNA repair by homologous recombination, HR) to inhibitors of the poly...... to PARP-1i. Here we addressed these issues using PARP-1i on 20 human cell lines from carcinomas of the breast, prostate, colon, pancreas and ovary. Aberrations of the Mre11-Rad50-Nbs1 (MRN) complex sensitized cancer cells to PARP-1i, while p53 status was less predictive, even in response to PARP-1i...

  19. PARP-1 and Ku compete for repair of DNA double strand breaks by distinct NHEJ pathways

    Science.gov (United States)

    Wang, Minli; Wu, Weizhong; Wu, Wenqi; Rosidi, Bustanur; Zhang, Lihua; Wang, Huichen; Iliakis, George

    2006-01-01

    Poly(ADP-ribose)polymerase 1 (PARP-1) recognizes DNA strand interruptions in vivo and triggers its own modification as well as that of other proteins by the sequential addition of ADP-ribose to form polymers. This modification causes a release of PARP-1 from DNA ends and initiates a variety of responses including DNA repair. While PARP-1 has been firmly implicated in base excision and single strand break repair, its role in the repair of DNA double strand breaks (DSBs) remains unclear. Here, we show that PARP-1, probably together with DNA ligase III, operates in an alternative pathway of non-homologous end joining (NHEJ) that functions as backup to the classical pathway of NHEJ that utilizes DNA-PKcs, Ku, DNA ligase IV, XRCC4, XLF/Cernunnos and Artemis. PARP-1 binds to DNA ends in direct competition with Ku. However, in irradiated cells the higher affinity of Ku for DSBs and an excessive number of other forms of competing DNA lesions limit its contribution to DSB repair. When essential components of the classical pathway of NHEJ are absent, PARP-1 is recruited for DSB repair, particularly in the absence of Ku and non-DSB lesions. This form of DSB repair is sensitive to PARP-1 inhibitors. The results define the function of PARP-1 in DSB repair and characterize a candidate pathway responsible for joining errors causing genomic instability and cancer. PMID:17088286

  20. PARP-1 and Ku compete for repair of DNA double strand breaks by distinct NHEJ pathways.

    Science.gov (United States)

    Wang, Minli; Wu, Weizhong; Wu, Wenqi; Rosidi, Bustanur; Zhang, Lihua; Wang, Huichen; Iliakis, George

    2006-01-01

    Poly(ADP-ribose)polymerase 1 (PARP-1) recognizes DNA strand interruptions in vivo and triggers its own modification as well as that of other proteins by the sequential addition of ADP-ribose to form polymers. This modification causes a release of PARP-1 from DNA ends and initiates a variety of responses including DNA repair. While PARP-1 has been firmly implicated in base excision and single strand break repair, its role in the repair of DNA double strand breaks (DSBs) remains unclear. Here, we show that PARP-1, probably together with DNA ligase III, operates in an alternative pathway of non-homologous end joining (NHEJ) that functions as backup to the classical pathway of NHEJ that utilizes DNA-PKcs, Ku, DNA ligase IV, XRCC4, XLF/Cernunnos and Artemis. PARP-1 binds to DNA ends in direct competition with Ku. However, in irradiated cells the higher affinity of Ku for DSBs and an excessive number of other forms of competing DNA lesions limit its contribution to DSB repair. When essential components of the classical pathway of NHEJ are absent, PARP-1 is recruited for DSB repair, particularly in the absence of Ku and non-DSB lesions. This form of DSB repair is sensitive to PARP-1 inhibitors. The results define the function of PARP-1 in DSB repair and characterize a candidate pathway responsible for joining errors causing genomic instability and cancer. PMID:17088286

  1. Lethality in PARP-1/Ku80 double mutant mice reveals physiologicalsynergy during early embryogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Henrie, Melinda S.; Kurimasa, Akihiro; Burma, Sandeep; Menissier-de Murcia, Josiane; de Murcia, Gilbert; Li, Gloria C.; Chen,David J.

    2002-09-24

    Ku is an abundant heterodimeric nuclear protein, consisting of 70-kDa and 86-kDa tightly associated subunits that comprise the DNA binding component of DNA-dependent protein kinase. Poly(ADP)ribose polymerase-1 (PARP-1) is a 113-kDa protein that catalyzes the synthesis of poly(ADP-ribose) on target proteins. Both Ku and PARP-1 recognize and bind to DNA ends. Ku functions in the non-homologous end joining (NHEJ) repair pathway whereas PARP-1 functions in the single strand break repair and base excision repair (BER) pathways. Recent studies have revealed that PARP-1 and Ku80 interact in vitro. To determine whether the association of PARP-1 and Ku80 has any physiological significance or synergistic function in vivo, mice lacking both PARP-1 and Ku80 were generated. The resulting offspring died during embryonic development displaying abnormalities around the gastrulation stage. In addition, PARP-1-/-Ku80-/- cultured blastocysts had an increased level of apoptosis. These data suggest that the functions of both Ku80 and PARP-1 are essential for normal embryogenesis and that a loss of genomic integrity leading to cell death through apoptosis is likely the cause of the embryonic lethality observed in these mice.

  2. PARP1 Val762Ala polymorphism reduces enzymatic activity

    International Nuclear Information System (INIS)

    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

  3. Novel PARP-1 inhibitors based on a 2-propanoyl-3H-quinazolin-4-one scaffold.

    Science.gov (United States)

    Giannini, Giuseppe; Battistuzzi, Gianfranco; Vesci, Loredana; Milazzo, Ferdinando M; De Paolis, Francesca; Barbarino, Marcella; Guglielmi, Mario Berardino; Carollo, Valeria; Gallo, Grazia; Artali, Roberto; Dallavalle, Sabrina

    2014-01-15

    Poly(ADP-ribose)polymerase-I (PARP-1) enzyme is involved in maintaining DNA integrity and programmed cell death. A virtual screening of commercial libraries led to the identification of five novel scaffolds with inhibitory profile in the low nanomolar range. A hit-to-lead optimization led to the identification of a group of new potent PARP-1 inhibitors, acyl-piperazinylamides of 3-(4-oxo-3,4-dihydro-quinazolin-2-yl)-propionic acid. Molecular modeling studies highlighted the preponderant role of the propanoyl side chain. PMID:24388690

  4. In Silico Investigation of Potential PARP-1 Inhibitors from Traditional Chinese Medicine

    Directory of Open Access Journals (Sweden)

    Kuan-Chung Chen

    2014-01-01

    Full Text Available Poly(ADP-ribose polymerases (PARPs are nuclear enzymes which catalyze the poly-ADP-ribosylation involved in gene transcription, DNA damage repair, and cell-death signaling. As PARP-1 protein contains a DNA-binding domain, which can bind to DNA strand breaks and repair the damaged DNA over a low basal level, the inhibitors of poly(ADP-ribose polymerase 1 (PARP-1 have been indicated as the agents treated for cancer. This study employed the compounds from TCM Database@Taiwan to identify the potential PARP-1 inhibitors from the vast repertoire of TCM compounds. The binding affinities of the potential TCM compounds were also predicted utilized several distinct scoring functions. Molecular dynamics simulations were performed to optimize the result of docking simulation and analyze the stability of interactions between protein and ligand. The top TCM candidates, isopraeroside IV, picrasidine M, and aurantiamide acetate, had higher potent binding affinities than control, A927929. They have stable H-bonds with residues Gly202 and, Ser243 as A927929 and stable H-bonds with residues Asp105, Tyr228, and His248 in the other side of the binding domain, which may strengthen and stabilize ligand inside the binding domain of PARP-1 protein. Hence, we propose isopraeroside IV and aurantiamide acetate as potential lead compounds for further study in drug development process with the PARP-1 protein.

  5. Histone deacetylase inhibitors decrease NHEJ both by acetylation of repair factors and trapping of PARP1 at DNA double-strand breaks in chromatin

    Science.gov (United States)

    Robert, Carine; Nagaria, Pratik K.; Pawar, Nisha; Adewuyi, Adeoluwa; Gojo, Ivana; Meyers, David J.; Cole, Philip A.; Rassool, Feyruz V.

    2016-01-01

    Histone deacetylase inhibitors (HDACi) induce acetylation of histone and non-histone proteins, and modulate the acetylation of proteins involved in DNA double-strand break (DSB) repair. Non-homologous end-joining (NHEJ) is one of the main pathways for repairing DSBs. Decreased NHEJ activity has been reported with HDACi treatment. However, mechanisms through which these effects are regulated in the context of chromatin are unclear. We show that pan-HDACi, trichostatin A (TSA), causes differential acetylation of DNA repair factors Ku70/Ku80 and poly ADP-ribose polymerase-1 (PARP1), and impairs NHEJ. Repair effects are reversed by treatments with p300/CBP inhibitor C646, with significantly decreased acetylation of PARP1. In keeping with these findings, TSA treatment significantly increases PARP1 binding to DSBs in chromatin. Notably, AML patients treated with HDACi entinostat (MS275) in vivo also show increased formation of poly ADP-ribose (PAR) that co-localizes with DSBs. Further, we demonstrate that PARP1 bound to chromatin increases with duration of TSA exposure, resembling PARP “trapping”. Knockdown of PARP1 inhibits trapping and mitigates HDACi effects on NHEJ. Finally, combination of HDACi with potent PARP inhibitor talazoparib (BMN673) shows a dose-dependent increase in PARP “trapping”, which correlates with increased apoptosis. These results provide a mechanism through which HDACi inhibits deacetylation and increases binding of PARP1 to DSBs, leading to decreased NHEJ and cytotoxicity of leukemia cells. PMID:27064363

  6. Histone deacetylase inhibitors decrease NHEJ both by acetylation of repair factors and trapping of PARP1 at DNA double-strand breaks in chromatin.

    Science.gov (United States)

    Robert, Carine; Nagaria, Pratik K; Pawar, Nisha; Adewuyi, Adeoluwa; Gojo, Ivana; Meyers, David J; Cole, Philip A; Rassool, Feyruz V

    2016-06-01

    Histone deacetylase inhibitors (HDACi) induce acetylation of histone and non-histone proteins, and modulate the acetylation of proteins involved in DNA double-strand break (DSB) repair. Non-homologous end-joining (NHEJ) is one of the main pathways for repairing DSBs. Decreased NHEJ activity has been reported with HDACi treatment. However, mechanisms through which these effects are regulated in the context of chromatin are unclear. We show that pan-HDACi, trichostatin A (TSA), causes differential acetylation of DNA repair factors Ku70/Ku80 and poly ADP-ribose polymerase-1 (PARP1), and impairs NHEJ. Repair effects are reversed by treatments with p300/CBP inhibitor C646, with significantly decreased acetylation of PARP1. In keeping with these findings, TSA treatment significantly increases PARP1 binding to DSBs in chromatin. Notably, AML patients treated with HDACi entinostat (MS275) in vivo also show increased formation of poly ADP-ribose (PAR) that co-localizes with DSBs. Further, we demonstrate that PARP1 bound to chromatin increases with duration of TSA exposure, resembling PARP "trapping". Knockdown of PARP1 inhibits trapping and mitigates HDACi effects on NHEJ. Finally, combination of HDACi with potent PARP inhibitor talazoparib (BMN673) shows a dose-dependent increase in PARP "trapping", which correlates with increased apoptosis. These results provide a mechanism through which HDACi inhibits deacetylation and increases binding of PARP1 to DSBs, leading to decreased NHEJ and cytotoxicity of leukemia cells. PMID:27064363

  7. Advances in using PARP inhibitors to treat cancer

    Directory of Open Access Journals (Sweden)

    Kummar Shivaani

    2012-03-01

    Full Text Available Abstract The poly (ADP-ribose polymerase (PARP family of enzymes plays a critical role in the maintenance of DNA integrity as part of the base excision pathway of DNA repair. PARP1 is overexpressed in a variety of cancers, and its expression has been associated with overall prognosis in cancer, especially breast cancer. A series of new therapeutic agents that are potent inhibitors of the PARP1 and PARP2 isoforms have demonstrated important clinical activity in patients with breast or ovarian cancers that are caused by mutations in either the BRCA1 or 2 genes. Results from such studies may define a new therapeutic paradigm, wherein simultaneous loss of the capacity to repair DNA damage may have antitumor activity in itself, as well as enhance the antineoplastic potential of cytotoxic chemotherapeutic agents.

  8. PARP-1 inhibitors: are they the long-sought genetically specific drugs for BRCA1/2-associated breast cancers?

    OpenAIRE

    De Soto, Joseph A.; Deng, Chu-Xia

    2006-01-01

    Recent studies demonstrated that PARP-1 [poly(ADP-ribose) polymerase-1] inhibitors kill breast cancer associated gene-1 and –2 (BRCA1/2) deficient cells with extremely high efficiency while BRCA+/- and BRCA+/+ cells are relatively non-responsive to the treatment. It was therefore proposed that PARP-1 inhibitors might be the long-sought genetically specific drugs that are both safe and effective for treating BRCA1/2-associated breast cancers. However, a report published in a recent issue of th...

  9. An affinity matrix for the purification of poly(ADP-ribose) glycohydrolase.

    OpenAIRE

    Thomassin, H; Jacobson, M K; Guay, J; Verreault, A; Aboul-Ela, N; Menard, L.; Poirier, G G

    1990-01-01

    The preparation of quantities of poly(ADP-ribose) glycohydrolase sufficient for detailed structural and enzymatic characterizations has been difficult due to the very low tissue content of the enzyme and its lability in late stages of purification. To date, the only purification of this enzyme to apparent homogeneity has involved a procedure requiring 6 column chromatographic steps. Described here is the preparation of an affinity matrix which consists of ADP-ribose polymers bound to dihydrox...

  10. Trial watch – inhibiting PARP enzymes for anticancer therapy

    Science.gov (United States)

    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

  11. Trial watch - inhibiting PARP enzymes for anticancer therapy.

    Science.gov (United States)

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

    2016-03-01

    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

  12. PARP-1 modulates amyloid beta peptide-induced neuronal damage.

    Directory of Open Access Journals (Sweden)

    Sara Martire

    Full Text Available Amyloid beta peptide (Aβ causes neurodegeneration by several mechanisms including oxidative stress, which is known to induce DNA damage with the consequent activation of poly (ADP-ribose polymerase (PARP-1. To elucidate the role of PARP-1 in the neurodegenerative process, SH-SY5Y neuroblastoma cells were treated with Aβ25-35 fragment in the presence or absence of MC2050, a new PARP-1 inhibitor. Aβ25-35 induces an enhancement of PARP activity which is prevented by cell pre-treatment with MC2050. These data were confirmed by measuring PARP-1 activity in CHO cells transfected with amylod precursor protein and in vivo in brains specimens of TgCRND8 transgenic mice overproducing the amyloid peptide. Following Aβ25-35 exposure a significant increase in intracellular ROS was observed. These data were supported by the finding that Aβ25-35 induces DNA damage which in turn activates PARP-1. Challenge with Aβ25-35 is also able to activate NF-kB via PARP-1, as demonstrated by NF-kB impairment upon MC2050 treatment. Moreover, Aβ25-35 via PARP-1 induces a significant increase in the p53 protein level and a parallel decrease in the anti-apoptotic Bcl-2 protein. These overall data support the hypothesis of PARP-1 involvment in cellular responses induced by Aβ and hence a possible rationale for the implication of PARP-1 in neurodegeneration is discussed.

  13. PARP1 expression, activity and ex vivo sensitivity to the PARP inhibitor, talazoparib (BMN 673), in chronic lymphocytic leukaemia.

    Science.gov (United States)

    Herriott, Ashleigh; Tudhope, Susan J; Junge, Gesa; Rodrigues, Natalie; Patterson, Miranda J; Woodhouse, Laura; Lunec, John; Hunter, Jill E; Mulligan, Evan A; Cole, Michael; Allinson, Lisa M; Wallis, Jonathan P; Marshall, Scott; Wang, Evelyn; Curtin, Nicola J; Willmore, Elaine

    2015-12-22

    In chronic lymphocytic leukemia (CLL), mutation and loss of p53 and ATM abrogate DNA damage signalling and predict poorer response and shorter survival. We hypothesised that poly (ADP-ribose) polymerase (PARP) activity, which is crucial for repair of DNA breaks induced by oxidative stress or chemotherapy, may be an additional predictive biomarker and a target for therapy with PARP inhibitors.We measured PARP activity in 109 patient-derived CLL samples, which varied widely (192 - 190052 pmol PAR/10⁶ cells) compared to that seen in healthy volunteer lymphocytes (2451 - 7519 pmol PAR/10⁶ cells). PARP activity was associated with PARP1 protein expression and endogenous PAR levels. PARP activity was not associated with p53 or ATM loss, Binet stage, IGHV mutational status or survival, but correlated with Bcl-2 and Rel A (an NF-kB subunit). Levels of 8-hydroxy-2'-deoxyguanosine in DNA (a marker of oxidative damage) were not associated with PAR levels or PARP activity. The potent PARP inhibitor, talazoparib (BMN 673), inhibited CD40L-stimulated proliferation of CLL cells at nM concentrations, independently of Binet stage or p53/ATM function.PARP activity is highly variable in CLL and correlates with stress-induced proteins. Proliferating CLL cells (including those with p53 or ATM loss) are highly sensitive to the PARP inhibitor talazoparib. PMID:26539646

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

    International Nuclear Information System (INIS)

    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. 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.

  16. 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).

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

    International Nuclear Information System (INIS)

    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. [PARP inhibitors and radiotherapy: rational and prospects for a clinical use].

    Science.gov (United States)

    Pernin, V; Mégnin-Chanet, F; Pennaneach, V; Fourquet, A; Kirova, Y; Hall, J

    2014-12-01

    Poly(ADP-ribosyl)ation is a ubiquitous protein modification involved in the regulation of many cellular processes that is carried out by the poly(ADP-ribose) polymerase (PARP) family. The PARP-1, PARP-2 and PARP-3 are the only PARPs known to be activated by DNA damage. The absence of PARP-1 and PARP-2, that are both activated by DNA damage and participate in DNA damage repair processes, results in hypersensitivity to ionizing radiation and alkylating agents. PARP inhibitors that compete with NAD(+) at the enzyme's activity site can be used in BRCA-deficient cells as single agent therapies acting through the principle of synthetic lethality exploiting these cells deficient DNA double-strand break repair. Preclinical data showing an enhancement of the response of tumors to radiation has been documented for several PARP inhibitors. However, whether this is due exclusively to impaired DNA damage responses or whether tumor re-oxygenation contributes to this radio-sensitization via the vasoactive effects of the PARP inhibitors remains to be fully determined. These promising results have paved the way for the evaluation of PARP inhibitors in combination with radiotherapy in phase I and phase II clinical trials for malignant glioma, head and neck, and breast cancers. A number of challenges remain that are also reviewed in this article, including the optimization of treatment schedules for combined therapies and the validation of biomarkers that will identify which patients will most benefit from either PARP inhibitors in combination with radiotherapy. PMID:25441760

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

    Science.gov (United States)

    Shang, Fenqing; Zhang, Jiao; Li, Zhao; Zhang, Jin; Yin, Yanjun; Wang, Yaqiong; Marin, Traci L; Gongol, Brendan; Xiao, Han; Zhang, You-Yi; Chen, Zhen; Shyy, John Y-J; Lei, Ting

    2016-01-01

    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-ribosyl)ation (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. PMID:26986624

  20. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  2. PARP-1 protein expression in glioblastoma multiforme

    Directory of Open Access Journals (Sweden)

    A. Galia

    2012-02-01

    Full Text Available One of the most common type of primary brain tumors in adults is the glioblastoma multiforme (GBM (World Health Organization grade IV astrocytoma. It is the most common malignant and aggressive form of glioma and it is among the most lethal ones. Poly (ADP-ribose polymerase 1 (PARP-1 gene, located to 1q42, plays an important role for the efficient maintenance of genome integrity. PARP-1 protein is required for the apoptosis-inducing factor (AIF translocation from the mitochondria to the nucleus. PARP-1 is proteolytically cleaved at the onset of apoptosis by caspase-3. Microarray analysis of PARP-1 gene expression in more than 8,000 samples revealed that PARP-1 is more highly expressed in several types of cancer compared with the equivalent normal tissues. Overall, the most differences in PARP-1 gene expression have been observed in breast, ovarian, endometrial, lung, and skin cancers, and non-Hodgkin’s lymphoma. We evaluated the expression of PARP-1 protein in normal brain tissues and primary GBM by immunohistochemistry. Positive nuclear PARP-1 staining was found in all samples with GBM, but not in normal neurons from controls (n=4 and GBM patients (n=27. No cytoplasmic staining was observed in any sample. In conclusion, PARP-1 gene is expressed in GBM. This finding may be envisioned as an attempt to trigger apoptosis in this tumor, as well as in many other malignancies. The presence of the protein exclusively at the nucleus further support the function played by this gene in genome integrity maintenance and apoptosis. Finally, PARP-1 staining may be used as GBM cell marker.

  3. PARP-1 inhibition induces a late increase in the level of reactive oxygen species in cells after ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Cieslar-Pobuda, Artur [Biosystems Group, Institute of Automatic Control, Silesian University of Technology, Akademicka 16, 44-100 Gliwice (Poland); Saenko, Yuriy [Biosystems Group, Institute of Automatic Control, Silesian University of Technology, Akademicka 16, 44-100 Gliwice (Poland); Center of Nanotechnology, Ulyanovsk State University, 432700 Ulyanovsk (Russian Federation); Rzeszowska-Wolny, Joanna, E-mail: Joanna.Rzeszowska@polsl.pl [Biosystems Group, Institute of Automatic Control, Silesian University of Technology, Akademicka 16, 44-100 Gliwice (Poland)

    2012-04-01

    Poly(ADP-ribose) polymerase 1 (PARP1), an enzyme activated by DNA strand breaks, synthesizes polymers of poly(ADP-ribose) (PAR) that modify chromatin and other proteins and play a role in DNA repair. Inhibition of PARP1 activity is considered a potentially important strategy in clinical practice, especially to sensitize tumor cells to chemo- and radiotherapy. Here we examined the influence of inhibition of PARP1 on formation of reactive oxygen species (ROS) and on DNA repair in cells exposed to ionizing radiation (IR). K562 (human myelogenous leukaemia) cells were grown and exposed to 4 or 12 Gy of ionizing radiation in presence or absence of the PARP inhibitor NU1025 (100 {mu}M). Intracellular ROS were assayed using the probe 2,7-dichlorofluorescein with detection by flow cytometry and the rejoining of DNA strand breaks were followed by alkaline single cell gel electrophoresis (comet) assays. In untreated cells a significant increase in PAR formation occurred during the first 5 min after IR, followed by a gradual decrease up to 30 min. Addition of a PARP inhibitor arrested the production of PAR almost completely and decreased the rate of rejoining of DNA strand breaks significantly; however, 3 h after irradiation we observed no difference in the amount of DNA strand breaks between PARP inhibitor-treated and untreated cells. Twelve to 48 h after irradiation, an increase of ROS concentration was observed in irradiated cells and ROS levels in PARP inhibitor-treated cells were significantly higher than in cells without inhibitor. Irradiated cells grown in the presence or absence of PARP inhibitor did not differ in the frequencies of apoptotic and necrotic cells or in the activity of caspases at 24, 48 and 72 h after irradiation. Poly(ADP-ribosylation) and inhibition of PARP1 appeared to modulate DNA strand break rejoining and influence the concentration of ROS in irradiated cells.

  4. PARP-1 inhibition induces a late increase in the level of reactive oxygen species in cells after ionizing radiation

    International Nuclear Information System (INIS)

    Poly(ADP-ribose) polymerase 1 (PARP1), an enzyme activated by DNA strand breaks, synthesizes polymers of poly(ADP-ribose) (PAR) that modify chromatin and other proteins and play a role in DNA repair. Inhibition of PARP1 activity is considered a potentially important strategy in clinical practice, especially to sensitize tumor cells to chemo- and radiotherapy. Here we examined the influence of inhibition of PARP1 on formation of reactive oxygen species (ROS) and on DNA repair in cells exposed to ionizing radiation (IR). K562 (human myelogenous leukaemia) cells were grown and exposed to 4 or 12 Gy of ionizing radiation in presence or absence of the PARP inhibitor NU1025 (100 μM). Intracellular ROS were assayed using the probe 2,7-dichlorofluorescein with detection by flow cytometry and the rejoining of DNA strand breaks were followed by alkaline single cell gel electrophoresis (comet) assays. In untreated cells a significant increase in PAR formation occurred during the first 5 min after IR, followed by a gradual decrease up to 30 min. Addition of a PARP inhibitor arrested the production of PAR almost completely and decreased the rate of rejoining of DNA strand breaks significantly; however, 3 h after irradiation we observed no difference in the amount of DNA strand breaks between PARP inhibitor-treated and untreated cells. Twelve to 48 h after irradiation, an increase of ROS concentration was observed in irradiated cells and ROS levels in PARP inhibitor-treated cells were significantly higher than in cells without inhibitor. Irradiated cells grown in the presence or absence of PARP inhibitor did not differ in the frequencies of apoptotic and necrotic cells or in the activity of caspases at 24, 48 and 72 h after irradiation. Poly(ADP-ribosylation) and inhibition of PARP1 appeared to modulate DNA strand break rejoining and influence the concentration of ROS in irradiated cells.

  5. Insights into the binding of PARP inhibitors to the catalytic domain of human tankyrase-2.

    Science.gov (United States)

    Qiu, Wei; Lam, Robert; Voytyuk, Oleksandr; Romanov, Vladimir; Gordon, Roni; Gebremeskel, Simon; Vodsedalek, Jakub; Thompson, Christine; Beletskaya, Irina; Battaile, Kevin P; Pai, Emil F; Rottapel, Robert; Chirgadze, Nickolay Y

    2014-10-01

    The poly(ADP-ribose) polymerase (PARP) family represents a new class of therapeutic targets with diverse potential disease indications. PARP1 and PARP2 inhibitors have been developed for breast and ovarian tumors manifesting double-stranded DNA-repair defects, whereas tankyrase 1 and 2 (TNKS1 and TNKS2, also known as PARP5a and PARP5b, respectively) inhibitors have been developed for tumors with elevated β-catenin activity. As the clinical relevance of PARP inhibitors continues to be actively explored, there is heightened interest in the design of selective inhibitors based on the detailed structural features of how small-molecule inhibitors bind to each of the PARP family members. Here, the high-resolution crystal structures of the human TNKS2 PARP domain in complex with 16 various PARP inhibitors are reported, including the compounds BSI-201, AZD-2281 and ABT-888, which are currently in Phase 2 or 3 clinical trials. These structures provide insight into the inhibitor-binding modes for the tankyrase PARP domain and valuable information to guide the rational design of future tankyrase-specific inhibitors. PMID:25286857

  6. Free energy calculation provides insight into the action mechanism of selective PARP-1 inhibitor.

    Science.gov (United States)

    Cao, Ran

    2016-04-01

    Selective poly (ADP-ribose) polymerase (PARP)-1 inhibitor represents promising therapy against cancers with a good balance between efficacy and safety. Owing to the conserved structure between PARP-1 and PARP-2, most of the clinical and experimental drugs show equivalent inhibition against both targets. Most recently, it's disclosed a highly selective PARP-1 inhibitor (NMS-P118) with promising pharmacokinetic properties. Herein, we combined molecular simulation with free energy calculation to gain insights into the selective mechanism of NMS-P118. Our results suggest the reduction of binding affinity for PARP-2 is attributed to the unfavorable conformational change of protein, which is accompanied by a significant energy penalty. Alanine-scanning mutagenesis study further reveals the important role for a tyrosine residue of donor loop (Tyr889(PARP-1) and Tyr455(PARP-2)) in contributing to the ligand selectivity. Retrospective structural analysis indicates the ligand-induced movement of Tyr455(PARP-2) disrupts the intra-molecule hydrogen bonding network, which partially accounts for the "high-energy" protein conformation in the presence of NMS-P118. Interestingly, such effect isn't observed in other non-selective PARP inhibitors including BMN673 and A861695, which validates the computational prediction. Our work provides energetic insight into the subtle variations in the crystal structures and could facilitate rational design of new selective PARP inhibitor. PMID:26969680

  7. Targeting PARP-1 allosteric regulation offers therapeutic potential against cancer

    OpenAIRE

    Steffen, Jamin D.; Tholey, Renee M.; Langelier, Marie-France; Planck, Jamie L.; Schiewer, Matthew J.; Lal, Shruti; Bildzukewicz, Nikolai A.; Yeo, Charles J.; Knudsen, Karen E.; Brody, Jonathan R; Pascal, John M.

    2013-01-01

    PARP-1 is a nuclear protein that has important roles in maintenance of genomic integrity. During genotoxic stress, PARP-1 recruits to sites of DNA damage where PARP-1 domain architecture initiates catalytic activation and subsequent poly(ADP-ribose)-dependent DNA repair. PARP-1 inhibition is a promising new way to selectively target cancers harboring DNA repair deficiencies. However, current inhibitors target other PARPs raising important questions concerning long-term off-target effects. Her...

  8. PARP inhibitors – theoretical basis and clinical application

    Directory of Open Access Journals (Sweden)

    Sylwia Dębska

    2012-05-01

    Full Text Available  Poly-ADP-ribose polymerases (PARP are involved in a number of processes that are vital for every living cell. Once activated by the presence of DNA damage they trigger poly-ADP-ribosylation of various proteins which are crucial for DNA repair, preserving of genom integrity, regulation of transcription, proliferation and apoptosis. PARP1, which is the best known enzyme of PARP protein family, plays a role in single-strand breaks (SSB repair. Decrease of its activity results in accumulation of single strand DNA breaks (SSB which leads as a consequence to double- strand breaks (DSBs. This disorder is particularly harmful to cells with deficiency of BRCA1/2 protein which is involved in repair of DNA double-strand breaks.This phenomenon is an example of “synthetic lethality” concept and contributes to research on application of PARP inhibitors in treatment of cancers associated with BRCA1/2 protein defect (breast or ovarian cancer.Noticed synergism between PARP inhibitors and genotoxic chemotherapy or radiotherapy determined another direction of research on application of these medicaments.After promising results of phase I and II trials with most commonly investigated PARP inhibitors – iniparib and olaparib- which recruited patients with triple negative breast cancer and ovarian cancer, further studies started.This paper presents theoretical basis of PARP inhibitors action as well as critical review of most important clinical trials of these medicaments.

  9. PARP1-Driven Apoptosis in Chronic Lymphocytic Leukemia

    Directory of Open Access Journals (Sweden)

    Panagiotis T. Diamantopoulos

    2014-01-01

    Full Text Available Chronic lymphocytic leukemia (CLL is considered a malignancy resulting from defects in apoptosis. For this reason, targeting apoptotic pathways in CLL may be valuable for its management. Poly [ADP-ribose] polymerase 1 (PARP1 is the main member of a family of nuclear enzymes that act as DNA damage sensors. Through binding on DNA damaged structures, PARP1 recruits repair enzymes and serves as a survival factor, but if the damage is severe enough, its action may lead the cell to apoptosis through caspase activation, or necrosis. We measured the PARP1 mRNA and protein pretreatment levels in 26 patients with CLL and the corresponding posttreatment levels in 15 patients after 3 cycles of immunochemotherapy, as well as in 15 healthy blood donors. No difference was found between the pre- and posttreatment levels of PARP1, but we found a statistically significant relative increase of the 89 kDa fragment of PARP1 that is cleaved by caspases in the posttreatment samples, indicating PARP1-related apoptosis in CLL patients after treatment. Our findings constitute an important step in the field, especially in the era of PARP1 inhibitors, and may serve as a base for future clinical trials with these agents in CLL.

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Ya-Chen; Hsu, Chiao-Yu [Institute of Molecular Biology, National Chung Hsing University, Taichung 40227, Taiwan (China); Yao, Ya-Li [Department of Biotechnology, Asia University, Taichung 41354, Taiwan (China); Yang, Wen-Ming, E-mail: yangwm@nchu.edu.tw [Institute of Molecular Biology, National Chung Hsing University, Taichung 40227, Taiwan (China)

    2013-02-01

    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. 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.

  13. Nuclear PARP1 expression and its prognostic significance in breast cancer patients.

    Science.gov (United States)

    Mazzotta, Annalisa; Partipilo, Giulia; De Summa, Simona; Giotta, Francesco; Simone, Giovanni; Mangia, Anita

    2016-05-01

    Poly(adenosine diphosphate [ADP]-ribose) polymerase 1 (PARP1) plays important roles in DNA damage response pathways and is often overexpressed in various human tumors. Currently, the use of PARP inhibitors for breast cancer (BC) therapy is the subject of debate, and there is an urgent need to understand much the expression and prognostic role of the PARP1 protein. The aim was to investigate the clinicopathological and prognostic significance of PARP1 in BC patients. The PARP1 and breast cancer susceptibility gene 1 (BRCA1) protein expressions were evaluated in 114 BCs by immunohistochemistry. Disease-free survival (DFS) and overall survival (OS) were determined based on the Kaplan-Meier method. Our results showed that nuclear PARP1 expression was significantly associated with peritumoral vascular invasion (P = 0.046), chemotherapeutic treatment (P = 0.026), oestrogen receptor (ER; P = 0.013), human epidermal growth factor receptor 2 (HER2; P = 0.003) and BRCA1 (P PARP1 expression was associated with decreased DFS (P = 0.012) and OS (P = 0.026). In conclusion, PARP1 expression may be used as an independent prognostic factor in BC patients. In addition, this study demonstrated that high PARP1 expression may represent a marker of poorer prognosis both for patients with worse clinical outcome and in less aggressive clinical conditions. PMID:26614429

  14. What Is the Place of PARP Inhibitors in Ovarian Cancer Treatment?

    Science.gov (United States)

    Liu, Joyce F; Matulonis, Ursula A

    2016-05-01

    Poly-ADP-ribose polymerase (PARP) inhibitors have been one of the most exciting developments in the treatment of ovarian cancer in recent years. Demonstration of anti-cancer activity has led to the European Medicines Agency (EMA) approval of the PARP inhibitor (PARPi) olaparib as maintenance therapy in women with BRCA-mutated (BRCAm) ovarian cancer with platinum-sensitive recurrence following response to platinum therapy and the US Food and Drug Administration (US FDA) approval of olaparib in relapsed germline BRCA-mutated (gBRCAm) ovarian cancer in women who have received at least three prior chemotherapy treatments, both occurring in 2014. Additional trials are underway or awaiting final analysis with olaparib, other PARPis, and PARPi combinations to further elucidate the activity of these drugs in various clinical settings. This review will focus on the current clinical experience and ongoing trials with PARPis in ovarian cancer. PMID:26984416

  15. Characterization of the interactions of PARP-1 with UV-damaged DNA in vivo and in vitro.

    Science.gov (United States)

    Purohit, Nupur K; Robu, Mihaela; Shah, Rashmi G; Geacintov, Nicholas E; Shah, Girish M

    2016-01-01

    The existing methodologies for studying robust responses of poly (ADP-ribose) polymerase-1 (PARP-1) to DNA damage with strand breaks are often not suitable for examining its subtle responses to altered DNA without strand breaks, such as UV-damaged DNA. Here we describe two novel assays with which we characterized the interaction of PARP-1 with UV-damaged DNA in vivo and in vitro. Using an in situ fractionation technique to selectively remove free PARP-1 while retaining the DNA-bound PARP-1, we demonstrate a direct recruitment of the endogenous or exogenous PARP-1 to the UV-lesion site in vivo after local irradiation. In addition, using the model oligonucleotides with single UV lesion surrounded by multiple restriction enzyme sites, we demonstrate in vitro that DDB2 and PARP-1 can simultaneously bind to UV-damaged DNA and that PARP-1 casts a bilateral asymmetric footprint from -12 to +9 nucleotides on either side of the UV-lesion. These techniques will permit characterization of different roles of PARP-1 in the repair of UV-damaged DNA and also allow the study of normal housekeeping roles of PARP-1 with undamaged DNA. PMID:26753915

  16. Inhibition of PARP1 by small interfering RNA enhances docetaxel activity against human prostate cancer PC3 cells

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Wenqi, E-mail: wwqwml@163.com [Department of Urology, Minimally Invasive Surgery Center, The First Affiliated Hospital of Guangzhou Medical University, Guangdong Key Laboratory of Urology (China); Kong, Zhenzhen; Duan, Xiaolu; Zhu, Hanliang; Li, Shujue; Zeng, Shaohua; Liang, Yeping [Department of Urology, Minimally Invasive Surgery Center, The First Affiliated Hospital of Guangzhou Medical University, Guangdong Key Laboratory of Urology (China); Iliakis, George [Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School, Essen (Germany); Gui, Zhiming [Department of Urology, The Affiliated Hospital of Guangdong Medical College (China); Yang, Dong [Department of Urology, Minimally Invasive Surgery Center, The First Affiliated Hospital of Guangzhou Medical University, Guangdong Key Laboratory of Urology (China)

    2013-12-06

    Highlights: •PARP1 siRNA enhances docetaxel’s activity against PC3 cells. •PARP1 siRNA enhances docetaxel’s activity against EGFR/Akt/FOXO1 pathway. •PARP1 siRNA and PARP1 inhibitor differently affect the phosphorylation and expression of FOXO1. -- Abstract: Though poly(ADP-ribose) polymerase 1 (PARP1) inhibitors have benefits in combination with radiotherapy in prostate cancers, few is known about the exactly role and underlying mechanism of PARP1 in combination with chemotherapy agents. Here our data revealed that inhibition of PARP1 by small interfering RNA (siRNA) could enhance docetaxel’s activity against PC3 cells, which is associated with an accelerate repression of EGF/Akt/FOXO1 signaling pathway. Our results provide a novel role of PARP1 in transcription regulation of EGFR/Akt/FOXO1 signaling pathway and indicate that PARP1 siRNA combined with docetaxel can be an innovative treatment strategy to potentially improve outcomes in CRPC patients.

  17. Inhibition of PARP1 by small interfering RNA enhances docetaxel activity against human prostate cancer PC3 cells

    International Nuclear Information System (INIS)

    Highlights: •PARP1 siRNA enhances docetaxel’s activity against PC3 cells. •PARP1 siRNA enhances docetaxel’s activity against EGFR/Akt/FOXO1 pathway. •PARP1 siRNA and PARP1 inhibitor differently affect the phosphorylation and expression of FOXO1. -- Abstract: Though poly(ADP-ribose) polymerase 1 (PARP1) inhibitors have benefits in combination with radiotherapy in prostate cancers, few is known about the exactly role and underlying mechanism of PARP1 in combination with chemotherapy agents. Here our data revealed that inhibition of PARP1 by small interfering RNA (siRNA) could enhance docetaxel’s activity against PC3 cells, which is associated with an accelerate repression of EGF/Akt/FOXO1 signaling pathway. Our results provide a novel role of PARP1 in transcription regulation of EGFR/Akt/FOXO1 signaling pathway and indicate that PARP1 siRNA combined with docetaxel can be an innovative treatment strategy to potentially improve outcomes in CRPC patients

  18. PARP1 Links CHD2-Mediated Chromatin Expansion and H3.3 Deposition to DNA Repair by Non-homologous End-Joining.

    Science.gov (United States)

    Luijsterburg, Martijn S; de Krijger, Inge; Wiegant, Wouter W; Shah, Rashmi G; Smeenk, Godelieve; de Groot, Anton J L; Pines, Alex; Vertegaal, Alfred C O; Jacobs, Jacqueline J L; Shah, Girish M; van Attikum, Haico

    2016-02-18

    The response to DNA double-strand breaks (DSBs) requires alterations in chromatin structure to promote the assembly of repair complexes on broken chromosomes. Non-homologous end-joining (NHEJ) is the dominant DSB repair pathway in human cells, but our understanding of how it operates in chromatin is limited. Here, we define a mechanism that plays a crucial role in regulating NHEJ in chromatin. This mechanism is initiated by DNA damage-associated poly(ADP-ribose) polymerase 1 (PARP1), which recruits the chromatin remodeler CHD2 through a poly(ADP-ribose)-binding domain. CHD2 in turn triggers rapid chromatin expansion and the deposition of histone variant H3.3 at sites of DNA damage. Importantly, we find that PARP1, CHD2, and H3.3 regulate the assembly of NHEJ complexes at broken chromosomes to promote efficient DNA repair. Together, these findings reveal a PARP1-dependent process that couples ATP-dependent chromatin remodeling with histone variant deposition at DSBs to facilitate NHEJ and safeguard genomic stability. PMID:26895424

  19. PARP inhibitors: its role in treatment of cancer

    Institute of Scientific and Technical Information of China (English)

    Alice Chen

    2011-01-01

    PARP is an important protein in DNA repair pathways especially the base excision repair (BER).BER is involved in DNA repair of single strand breaks (SSBs). If BER is impaired, inhibiting poly(ADP-ribose) polymerase (PARP), SSBs accumulate and become double stand breaks (DSBs). The cells with increasing number of DSBs become more dependent on other repair pathways, mainly the homologous recombination (HR) and the nonhomologous end joining. Patients with defective HR, like BRCA-deficient cell lines, are even more susceptible to impairment of the BER pathway. Inhibitors of PARP preferentially kill cancer cells in BRCA-mutation cancer cell lines over normal cells. Also, PARP inhibitors increase cytotoxicity by inhibiting repair in the presence of chemotherapies that induces SSBs. These two principles have been tested clinically. Over the last few years, excitement over this class of agents has escalated due to reported activity as single agent in BRCA1- or BRCA2-associated ovarian or breast cancers, and in combination with chemotherapy in tdple negative breast cancer. This review covers the current results of clinical trials testing those two principles. It also evaluates future directions for the field of PARP inhibitor development.

  20. Prediction of PARP Inhibition with Proteochemometric Modelling and Conformal Prediction.

    Science.gov (United States)

    Cortés-Ciriano, Isidro; Bender, Andreas; Malliavin, Thérèse

    2015-06-01

    Poly(ADP-ribose) polymerases (PARPs) play a key role in DNA damage repair. PARP inhibitors act as chemo- and radio- sensitizers and thus potentiate the cytotoxicity of DNA damaging agents. Although PARP inhibitors are currently investigated as chemotherapeutic agents, their cross-reactivity with other members of the PARP family remains unclear. Here, we apply Proteochemometric Modelling (PCM) to model the activity of 181 compounds on 12 human PARPs. We demonstrate that PCM (R0 (2) test =0.65-0.69; RMSEtest =0.95-1.01 °C) displays higher performance on the test set (interpolation) than Family QSAR and Family QSAM (Tukey's HSD, α 0.05), and outperforms Inductive Transfer knowledge among targets (Tukey's HSD, α 0.05). We benchmark the predictive signal of 8 amino acid and 11 full-protein sequence descriptors, obtaining that all of them (except for SOCN) perform at the same level of statistical significance (Tukey's HSD, α 0.05). The extrapolation power of PCM to new compounds (RMSE=1.02±0.80 °C) and targets (RMSE=1.03±0.50 °C) is comparable to interpolation, although the extrapolation ability is not uniform across the chemical and the target space. For this reason, we also provide confidence intervals calculated with conformal prediction. In addition, we present the R package conformal, which permits the calculation of confidence intervals for regression and classification caret models. PMID:27490382

  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. Differential Localisation of PARP-1 N-Terminal Fragment in PARP-1+/+ and PARP-1−/− Murine Cells

    OpenAIRE

    Rajiah, Ida Rachel; Skepper, Jeremy

    2014-01-01

    Human PARP family consists of 17 members of which PARP-1 is a prominent member and plays a key role in DNA repair pathways. It has an N-terminal DNA-binding domain (DBD) encompassing the nuclear localisation signal (NLS), central automodification domain and C-terminal catalytic domain. PARP-1 accounts for majority of poly-(ADP-ribose) polymer synthesis that upon binding to numerous proteins including PARP itself modulates their activity. Reduced PARP-1 activity in ageing human samples and its...

  3. 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)

    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

  4. Modulation of PARP-1 and PARP-2 expression by L-carnosine and trehalose after LPS and INFγ-induced oxidative stress.

    Science.gov (United States)

    Spina-Purrello, Vittoria; Giliberto, Salvatrice; Barresi, Vincenza; Nicoletti, Vincenzo G; Giuffrida Stella, Anna Maria; Rizzarelli, Enrico

    2010-12-01

    Poly(ADP-ribose) polymerases (PARPs) play a crucial role in DNA damage surveillance through their nick sensor functions. Since PARPs' over activation leads to an excessive consumption of NAD(+) and ATP depletion, these enzymes also are involved in the early events of programmed cell death as well as in necrosis. In order to verify the protective action of L: -carnosine and trehalose against NO induced cell death, in the present study we examined their effects on the expression of PARP-1, PARP-2 and iNOS in primary rat astrocyte and oligodendrocyte cells, treated with lipopolysaccharide (LPS) and interferon gamma (INFγ), through semi-quantitative PCR and western analysis. To further characterize the molecular mechanisms underlying L-carnosine and trehalose action, we measured cell viability, nitrite production and LDH release. The data obtained clearly demonstrate that in the stress model employed L-carnosine and trehalose down regulate PARP-1 and PARP-2 expression in both cell phenotypes, thus suggesting their possible application in clinical trials. PMID:21053069

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. [PARP1 inhibitors: contemporary attempts at their use in anticancer therapy and future perspective].

    Science.gov (United States)

    Wiśnik, Ewelina; Ryksa, Marcin; Koter-Michalak, Maria

    2016-01-01

    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. PMID:27117104

  8. PARP-1 transcriptional activity is regulated by sumoylation upon heat shock.

    Science.gov (United States)

    Martin, Nadine; Schwamborn, Klaus; Schreiber, Valérie; Werner, Andreas; Guillier, Christelle; Zhang, Xiang-Dong; Bischof, Oliver; Seeler, Jacob-S; Dejean, Anne

    2009-11-18

    Heat shock and other environmental stresses rapidly induce transcriptional responses subject to regulation by a variety of post-translational modifications. Among these, poly(ADP-ribosyl)ation and sumoylation have received growing attention. Here we show that the SUMO E3 ligase PIASy interacts with the poly(ADP-ribose) polymerase PARP-1, and that PIASy mediates heat shock-induced poly-sumoylation of PARP-1. Furthermore, PIASy, and hence sumoylation, appears indispensable for full activation of the inducible HSP70.1 gene. Chromatin immunoprecipitation experiments show that PIASy, SUMO and the SUMO-conjugating enzyme Ubc9 are rapidly recruited to the HSP70.1 promoter upon heat shock, and that they are subsequently released with kinetics similar to PARP-1. Finally, we provide evidence that the SUMO-targeted ubiquitin ligase RNF4 mediates heat-shock-inducible ubiquitination of PARP-1, regulates the stability of PARP-1, and, like PIASy, is a positive regulator of HSP70.1 gene activity. These results, thus, point to a novel mechanism for regulating PARP-1 transcription function, and suggest crosstalk between sumoylation and RNF4-mediated ubiquitination in regulating gene expression in response to heat shock. PMID:19779455

  9. Connexin-43 hemichannels mediate cyclic ADP-ribose generation and its Ca2+-mobilizing activity by NAD+/cyclic ADP-ribose transport.

    Science.gov (United States)

    Song, Eun-Kyung; Rah, So-Young; Lee, Young-Rae; Yoo, Chae-Hwa; Kim, Yu-Ri; Yeom, Ji-Hyun; Park, Kwang-Hyun; Kim, Jong-Suk; Kim, Uh-Hyun; Han, Myung-Kwan

    2011-12-30

    The ADP-ribosyl cyclase CD38 whose catalytic domain resides in outside of the cell surface produces the second messenger cyclic ADP-ribose (cADPR) from NAD(+). cADPR increases intracellular Ca(2+) through the intracellular ryanodine receptor/Ca(2+) release channel (RyR). It has been known that intracellular NAD(+) approaches ecto-CD38 via its export by connexin (Cx43) hemichannels, a component of gap junctions. However, it is unclear how cADPR extracellularly generated by ecto-CD38 approaches intracellular RyR although CD38 itself or nucleoside transporter has been proposed to import cADPR. Moreover, it has been unknown what physiological stimulation can trigger Cx43-mediated export of NAD(+). Here we demonstrate that Cx43 hemichannels, but not CD38, import cADPR to increase intracellular calcium through RyR. We also demonstrate that physiological stimulation such as Fcγ receptor (FcγR) ligation induces calcium mobilization through three sequential steps, Cx43-mediated NAD(+) export, CD38-mediated generation of cADPR and Cx43-mediated cADPR import in J774 cells. Protein kinase A (PKA) activation also induced calcium mobilization in the same way as FcγR stimulation. FcγR stimulation-induced calcium mobilization was blocked by PKA inhibition, indicating that PKA is a linker between FcγR stimulation and NAD(+)/cADPR transport. Cx43 knockdown blocked extracellular cADPR import and extracellular cADPR-induced calcium mobilization in J774 cells. Cx43 overexpression in Cx43-negative cells conferred extracellular cADPR-induced calcium mobilization by the mediation of cADPR import. Our data suggest that Cx43 has a dual function exporting NAD(+) and importing cADPR into the cell to activate intracellular calcium mobilization. PMID:22033928

  10. Inhibition of PARP-1 participates in the mechanisms of propofol-induced amnesia in mice and human.

    Science.gov (United States)

    Jia, Lijie; Wang, Wenyuan; Luo, Yan; Zhang, Fujun; Lu, Han; Xue, Qingsheng; Yu, Buwei

    2016-04-15

    Poly(ADP-ribose) polymerase 1 (PARP-1) has emerged as an important regulator in learning and memory. Propofol leads to amnesia, however, the mechanism remains unclear. The present study was designed to examine whether and how PARP-1 plays a role in propofol-induced amnesia. Mice were injected intraperitoneally with propofol before acquisition training. Cognitive function was evaluated by object recognition test. PARP-1 and PAR expression was determined through Western blot. The protein and mRNA levels of Arc and c-Fos were detected by Western blot and real-time PCR. Thirty volunteers were assigned to three groups according to codon 762 variation of PARP-1 gene (rs1136410). They learned word lists awake and during propofol sedation. Their cognitive traits were evaluated through fMRI. Rodent data demonstrated that propofol inhibited acquisition-induced increase in PARP-1 and PAR, thereby suppressing Arc and c-Fos, which impaired object recognition 24h after learning. Consistent with this, carriers of a low-catalyzing function PARP-1 variant (Val762Ala) exhibited decreased retrieval-induced hippocampal reactivity 24h after learning under propofol-sedative condition. These findings suggested that inhibition of PARP-1 might participate in the mechanism of propofol-induced amnesia in mice and human. More generally, our approach illustrated a potential translational research bridging animal models and human studies. PMID:26921778

  11. 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.

  12. PARP1 inhibitors attenuate AKT phosphorylation via the upregulation of PHLPP1

    International Nuclear Information System (INIS)

    Highlights: → PARP1 inhibitors cause a cytotoxic effect independent of DNA repair impairment. → PARP1 inhibitors attenuated AKT-FOXO3A signaling by activating PHLPP1. → PHLPP1 regulates the sensitivity of cancer cells to PARP1 inhibitors. -- Abstract: Poly(ADP-ribose) polymerase-1 (PARP1) inhibitors are emerging as an important class of drugs for treating BRCA-deficient cancers. Recent discoveries have shown that PARP1 inhibitors may treat other cancer patients in addition to the relatively small proportion of patients carrying BRCA mutations. However, the additional targets by which PARP1 inhibitor-mediated tumor suppression remain poorly understood. In this study, we show that two PARP1 inhibitors, PJ-34 and 3-AB, attenuate AKT phosphorylation at serine 473 (S473) independent of DNA repair impairment. These inhibitors decrease the AKT-associated phosphorylation of FOXO3A, enhance the nuclear retention of FOXO3A, and activate its transcriptional activity. We further demonstrate that treatment with PJ-34 or 3-AB dramatically increases the level of PHLPP1. Overexpression of PHLPP1 enhances the PARP1 inhibitor-induced downregulation of AKT phosphorylation and increases tumor cell death. In contrast, knockdown of PHLPP1 abrogates the PARP1 inhibitor-mediated AKT inhibition and desensitizes cells to its treatment. Therefore, our findings not only show the robust role of PARP1 inhibitors in AKT inhibition but also develop a novel strategy to increase the effectiveness of cancer treatment via PARP1 inhibitor-induced PHLPP1 upregulation.

  13. PARP1 inhibitors attenuate AKT phosphorylation via the upregulation of PHLPP1

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shuai [State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025 (China); Division of Hematology and Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35205 (United States); Wang, Huibo; Davis, Ben C. [Division of Hematology and Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35205 (United States); Liang, Jiyong [Department of Systems Biology, University of Texas MD Anderson Cancer Center, Houston, TX 77054 (United States); Cui, Rutao [Department of Dermatology, Boston University School of Medicine, Boston, MA 02118 (United States); Chen, Sai-Juan, E-mail: sjchen@stn.sh.cn [State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025 (China); Xu, Zhi-Xiang, E-mail: zhi-xiang.xu@ccc.uab.edu [Division of Hematology and Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35205 (United States)

    2011-08-26

    Highlights: {yields} PARP1 inhibitors cause a cytotoxic effect independent of DNA repair impairment. {yields} PARP1 inhibitors attenuated AKT-FOXO3A signaling by activating PHLPP1. {yields} PHLPP1 regulates the sensitivity of cancer cells to PARP1 inhibitors. -- Abstract: Poly(ADP-ribose) polymerase-1 (PARP1) inhibitors are emerging as an important class of drugs for treating BRCA-deficient cancers. Recent discoveries have shown that PARP1 inhibitors may treat other cancer patients in addition to the relatively small proportion of patients carrying BRCA mutations. However, the additional targets by which PARP1 inhibitor-mediated tumor suppression remain poorly understood. In this study, we show that two PARP1 inhibitors, PJ-34 and 3-AB, attenuate AKT phosphorylation at serine 473 (S473) independent of DNA repair impairment. These inhibitors decrease the AKT-associated phosphorylation of FOXO3A, enhance the nuclear retention of FOXO3A, and activate its transcriptional activity. We further demonstrate that treatment with PJ-34 or 3-AB dramatically increases the level of PHLPP1. Overexpression of PHLPP1 enhances the PARP1 inhibitor-induced downregulation of AKT phosphorylation and increases tumor cell death. In contrast, knockdown of PHLPP1 abrogates the PARP1 inhibitor-mediated AKT inhibition and desensitizes cells to its treatment. Therefore, our findings not only show the robust role of PARP1 inhibitors in AKT inhibition but also develop a novel strategy to increase the effectiveness of cancer treatment via PARP1 inhibitor-induced PHLPP1 upregulation.

  14. PARP inhibition and postinfarction myocardial remodeling.

    Science.gov (United States)

    Halmosi, Robert; Deres, Laszlo; Gal, Roland; Eros, Krisztian; Sumegi, Balazs; Toth, Kalman

    2016-08-01

    Coronary artery disease accounts for the greatest proportion of cardiovascular diseases therefore it is the major cause of death worldwide. Its therapeutic importance is indicated by still high mortality of myocardial infarction, which is one of the most severe forms of CVDs. Moreover, the risk of developing heart failure is very high among survivors. Heart failure is accompanied by high morbidity and mortality rate, therefore this topic is in the focus of researchers' interest. After a myocardial infarct, at first ventricular hypertrophy develops as a compensatory mechanism to decrease wall stress but finally leads to left ventricular dilation. This phenomenon is termed as myocardial remodeling. The main characteristics of underlying mechanisms involve cardiomyocyte growth, vessel changes and increased collagen production, in all of which several mechanical stress induced neurohumoral agents, oxidative stress and signal transduction pathways are involved. The long term activation of these processes ultimately leads to left ventricular dilation and heart failure with decreased systolic function. Oxidative stress causes DNA breaks producing the activation of nuclear poly(ADP-ribose) polymerase-1 (PARP-1) enzyme that leads to energy depletion and unfavorable modulation of different kinase cascades (Akt-1/GSK-3β, MAPKs, various PKC isoforms) and thus it promotes the development of heart failure. Therefore inhibition of PARP enzyme could offer a promising new therapeutical approach to prevent the onset of heart failure among postinfarction patients. The purpose of this review is to give a comprehensive summary about the most significant experimental results and mechanisms in postinfarction remodeling. PMID:27392900

  15. PARP-1 inhibition influences the oxidative stress response of the human lens

    Directory of Open Access Journals (Sweden)

    Andrew J.O. Smith

    2016-08-01

    Full Text Available Poly(ADP-ribose polymerase-1 (PARP-1 is best characterised for its involvement in DNA repair. PARP-1 activity is also linked to cell fate, confounding its roles in maintaining genome integrity. The current study assessed the functional roles of PARP-1 within human lens cells in response to oxidative stress. The human lens epithelial cell line FHL124 and whole human lens cultures were used as experimental systems. Hydrogen peroxide (H2O2 was employed to induce oxidative stress and cell death was assessed by LDH release. The functional influence of PARP-1 was assessed using targeted siRNA and chemical inhibition (by AG14361. Immunocytochemistry and western blotting were used to assess PARP-1 expression and the alkaline comet assay determined the levels of DNA strand breaks. PARP-1 was generally observed in the cell nucleus in both the FHL124 cell line and whole human lenses. PARP-1 inhibition rendered FHL124 cells more susceptible to H2O2-induced DNA strand breaks. Interestingly, reduction of PARP-1 activity significantly inhibited H2O2-induced cell death relative to control cells. Inhibition of PARP-1 in whole human lenses resulted in a reduced level of lens opacity and cell death following exposure to H2O2 relative to matched pair controls. Thus, we show that PARP-1 could play a role in the fate of human lens cells, and these first observations in human lenses suggest that it could impact on lens opacity. Further studies are required to elucidate the regulatory processes that give rise to these effects.

  16. PARP-1 inhibition influences the oxidative stress response of the human lens.

    Science.gov (United States)

    Smith, Andrew J O; Ball, Simon S R; Bowater, Richard P; Wormstone, I Michael

    2016-08-01

    Poly(ADP-ribose) polymerase-1 (PARP-1) is best characterised for its involvement in DNA repair. PARP-1 activity is also linked to cell fate, confounding its roles in maintaining genome integrity. The current study assessed the functional roles of PARP-1 within human lens cells in response to oxidative stress. The human lens epithelial cell line FHL124 and whole human lens cultures were used as experimental systems. Hydrogen peroxide (H2O2) was employed to induce oxidative stress and cell death was assessed by LDH release. The functional influence of PARP-1 was assessed using targeted siRNA and chemical inhibition (by AG14361). Immunocytochemistry and western blotting were used to assess PARP-1 expression and the alkaline comet assay determined the levels of DNA strand breaks. PARP-1 was generally observed in the cell nucleus in both the FHL124 cell line and whole human lenses. PARP-1 inhibition rendered FHL124 cells more susceptible to H2O2-induced DNA strand breaks. Interestingly, reduction of PARP-1 activity significantly inhibited H2O2-induced cell death relative to control cells. Inhibition of PARP-1 in whole human lenses resulted in a reduced level of lens opacity and cell death following exposure to H2O2 relative to matched pair controls. Thus, we show that PARP-1 could play a role in the fate of human lens cells, and these first observations in human lenses suggest that it could impact on lens opacity. Further studies are required to elucidate the regulatory processes that give rise to these effects. PMID:26990173

  17. PARP1 gene knock-out increases resistance to retinal degeneration without affecting retinal function.

    Directory of Open Access Journals (Sweden)

    Ayse Sahaboglu

    Full Text Available Retinitis pigmentosa (RP is a group of inherited neurodegenerative diseases affecting photoreceptors and causing blindness in humans. Previously, excessive activation of enzymes belonging to the poly-ADP-ribose polymerase (PARP group was shown to be involved in photoreceptor degeneration in the human homologous rd1 mouse model for RP. Since there are at least 16 different PARP isoforms, we investigated the exact relevance of the predominant isoform - PARP1 - for photoreceptor cell death using PARP1 knock-out (KO mice. In vivo and ex vivo morphological analysis using optic coherence tomography (OCT and conventional histology revealed no major alterations of retinal phenotype when compared to wild-type (wt. Likewise, retinal function as assessed by electroretinography (ERG was normal in PARP1 KO animals. We then used retinal explant cultures derived from wt, rd1, and PARP1 KO animals to test their susceptibility to chemically induced photoreceptor degeneration. Since photoreceptor degeneration in the rd1 retina is triggered by a loss-of-function in phosphodiesterase-6 (PDE6, we used selective PDE6 inhibition to emulate the rd1 situation on non-rd1 genotypes. While wt retina subjected to PDE6 inhibition showed massive photoreceptor degeneration comparable to rd1 retina, in the PARP1 KO situation, cell death was robustly reduced. Together, these findings demonstrate that PARP1 activity is in principle dispensable for normal retinal function, but is of major importance for photoreceptor degeneration under pathological conditions. Moreover, our results suggest that PARP dependent cell death or PARthanatos may play a major role in retinal degeneration and highlight the possibility to use specific PARP inhibitors for the treatment of RP.

  18. Low concentration of arsenite exacerbates UVR-induced DNA strand breaks by inhibiting PARP-1 activity.

    Science.gov (United States)

    Qin, Xu-Jun; Hudson, Laurie G; Liu, Wenlan; Timmins, Graham S; Liu, Ke Jian

    2008-10-01

    Epidemiological studies have associated arsenic exposure with many types of human cancers. Arsenic has also been shown to act as a co-carcinogen even at low concentrations. However, the precise mechanism of its co-carcinogenic action is unknown. Recent studies indicate that arsenic can interfere with DNA-repair processes. Poly(ADP-ribose) polymerase (PARP)-1 is a zinc-finger DNA-repair protein, which can promptly sense DNA strand breaks and initiate DNA-repair pathways. In the present study, we tested the hypothesis that low concentrations of arsenic could inhibit PAPR-1 activity and so exacerbate levels of ultraviolet radiation (UVR)-induced DNA strand breaks. HaCat cells were treated with arsenite and/or UVR, and then DNA strand breaks were assessed by comet assay. Low concentrations of arsenite (mechanism. Combination treatments of arsenite with PARP-1 inhibitor 3-aminobenzamide or PARP-1 siRNA demonstrate that PARP-1 is the target of arsenite. Together, these findings show that arsenite at low concentration exacerbates UVR-induced DNA strand breaks by inhibiting PARP-1 activity, which may represent an important mechanism underlying the co-carcinogenicity of arsenic. PMID:18619636

  19. In Silico Screening Identifies a Novel Potential PARP1 Inhibitor Targeting Synthetic Lethality in Cancer Treatment.

    Science.gov (United States)

    Li, Jian; Zhou, Nan; Cai, Peiling; Bao, Jinku

    2016-01-01

    Synthetic lethality describes situations in which defects in two different genes or pathways together result in cell death. This concept has been applied to drug development for cancer treatment, as represented by Poly (ADP-ribose) polymerase (PARPs) inhibitors. In the current study, we performed a computational screening to discover new PARP inhibitors. Among the 11,247 compounds analyzed, one natural product, ZINC67913374, stood out by its superior performance in the simulation analyses. Compared with the FDA approved PARP1 inhibitor, olaparib, our results demonstrated that the ZINC67913374 compound achieved a better grid score (-86.8) and amber score (-51.42). Molecular dynamics simulations suggested that the PARP1-ZINC67913374 complex was more stable than olaparib. The binding free energy for ZINC67913374 was -177.28 kJ/mol while that of olaparib was -159.16 kJ/mol. These results indicated ZINC67913374 bound to PARP1 with a higher affinity, which suggest ZINC67913374 has promising potential for cancer drug development. PMID:26907257

  20. In Silico Screening Identifies a Novel Potential PARP1 Inhibitor Targeting Synthetic Lethality in Cancer Treatment

    Directory of Open Access Journals (Sweden)

    Jian Li

    2016-02-01

    Full Text Available Synthetic lethality describes situations in which defects in two different genes or pathways together result in cell death. This concept has been applied to drug development for cancer treatment, as represented by Poly (ADP-ribose polymerase (PARPs inhibitors. In the current study, we performed a computational screening to discover new PARP inhibitors. Among the 11,247 compounds analyzed, one natural product, ZINC67913374, stood out by its superior performance in the simulation analyses. Compared with the FDA approved PARP1 inhibitor, olaparib, our results demonstrated that the ZINC67913374 compound achieved a better grid score (−86.8 and amber score (−51.42. Molecular dynamics simulations suggested that the PARP1-ZINC67913374 complex was more stable than olaparib. The binding free energy for ZINC67913374 was −177.28 kJ/mol while that of olaparib was −159.16 kJ/mol. These results indicated ZINC67913374 bound to PARP1 with a higher affinity, which suggest ZINC67913374 has promising potential for cancer drug development.

  1. PARP inhibitor ABT-888 affects response of MDA-MB-231 cells to doxorubicin treatment, targeting Snail expression.

    Science.gov (United States)

    Mariano, Germano; Ricciardi, Maria Rosaria; Trisciuoglio, Daniela; Zampieri, Michele; Ciccarone, Fabio; Guastafierro, Tiziana; Calabrese, Roberta; Valentini, Elisabetta; Tafuri, Agostino; Del Bufalo, Donatella; Caiafa, Paola; Reale, Anna

    2015-06-20

    To overcome cancer cells resistance to pharmacological therapy, the development of new therapeutic approaches becomes urgent. For this purpose, the use of poly(ADP-ribose) polymerase (PARP) inhibitors in combination with other cytotoxic agents could represent an efficacious strategy. Poly(ADP-ribosyl)ation (PARylation) is a post-translational modification that plays a well characterized role in the cellular decisions of life and death. Recent findings indicate that PARP-1 may control the expression of Snail, the master gene of epithelial-mesenchymal transition (EMT). Snail is highly represented in different resistant tumors, functioning as a factor regulating anti-apoptotic programmes. MDA-MB-231 is a Snail-expressing metastatic breast cancer cell line, which exhibits chemoresistance properties when treated with damaging agents. In this study, we show that the PARP inhibitor ABT-888 was capable to modulate the MDA-MB-231 cell response to doxorubicin, leading to an increase in the rate of apoptosis. Our further results indicate that PARP-1 controlled Snail expression at transcriptional level in cells exposed to doxorubicin. Given the increasing interest in the employment of PARP inhibitors as chemotherapeutic adjuvants, our in vitro results suggest that one of the mechanisms through which PARP inhibition can chemosensitize cancer cells in vivo, is targeting Snail expression thus promoting apoptosis. PMID:25938539

  2. The PARP1/ARTD1-Mediated Poly-ADP-Ribosylation and DNA Damage Repair in B Cell Diversification

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    Jackline J.M. Lasola

    2014-01-01

    Full Text Available ADP-ribosylation is an essential post-translational modification, mediated by a family of proteins named poly-ADP-ribose polymerases/Diphtheria toxin-like ADP-ribosyltransferases (PARPs/ARTDs, that functions to assist in cellular homeostasis through an array of mechanisms. Although the function of PARP1/ARTD1-mediated poly-ADP-ribosylation (PARylation in response to environmental genotoxic stressors has been extensively studied, its role in the regulation and maintenance of cellular events under times of programmed DNA damage and repair remains to be elucidated. In the case of B cell maturation and differentiation, processes such as V(DJ recombination, somatic hypermutation, and class switch recombination, require the induction of DNA strand breaks for the generation of a varied immunoglobulin repertoire and, thus, serve as a model system to explore the function of PARylation in immunological processes. In this review, we summarize the current understanding of ADP-ribosylation and the PARPs/ARTDs family proteins, in particular PARP1/ARTD1-conferred PARylation, in B cells. Following an overview of PARylation in cellular responses to environmental and spontaneous DNA damage, we discuss the emerging function of PARP1/ARTD1 and PARylation in DNA damage-induced nuclear factor kappaB (NF-κB signaling and B cell maturation and differentiation. Finally, we conclude by underlining further efforts that are needed to understand how the PARPs/ARTDs family proteins and ADP-ribosylation control the development and function of B cells.

  3. Metabotropic glutamate receptor activation and intracellular cyclic ADP-ribose release Ca2+ from the same store in cultured DRG neurones.

    Science.gov (United States)

    Pollock, J; Crawford, J H; Wootton, J F; Seabrook, G R; Scott, R H

    1999-01-01

    The whole cell patch clamp technique has been used to record Ca(2+)-activated cation and chloride conductances evoked by release of Ca2+ from intracellular stores of cultured neonatal dorsal root ganglion neurones. The aim of this study was to investigate metabotropic glutamate receptor (mGluR) mechanisms and evaluate a possible role for cyclic ADP-ribose as an intracellular signalling molecule. Glutamate and the metabotropic glutamate receptor agonist (1S, 3R)-ACPD-evoked transient depolarizations, Ca(2+)-activated inward currents and rises in intracellular Ca2+. The (1S, 3R)-ACPD-activated currents were insensitive to InsP3 signalling inhibitors, heparin and pentosan polysulphate. Intracellular application of ryanodine alone activated currents in this study and proved a difficult tool to use as a potential inhibitor of cyclic ADP-ribose-mediated responses. However, intracellular dantrolene did attenuate both (1S, 3R)-ACPD and cyclic ADP-ribose responses. Intracellular photo-release of cGMP and cyclic ADP-ribose mimicked the responses to mGluR receptor activation. Intracellular application of nicotinamide and W7 inhibited the responses to photo-released cGMP but did not prevent responses to mGluR activation. The cyclic ADP-ribose receptor antagonist 8-amino cyclic ADP-ribose attenuated responses to (1S, 3R)-ACPD, cGMP and cyclic ADP-ribose, but some Ca(2+)-activated inward currents were still observed in the presence of this antagonist. In conclusion, mGluR receptor activation, cGMP and cyclic ADP-ribose release Ca2+ from intracellular stores. Some evidence suggests that pharmacologically related pathways are involved. PMID:10598278

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

    Directory of Open Access Journals (Sweden)

    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.

  5. PARP-1 inhibitors DPQ and PJ-34 negatively modulate proinflammatory commitment of human glioblastoma cells.

    Science.gov (United States)

    Scalia, Marina; Satriano, Cristina; Greca, Rossana; Stella, Anna Maria Giuffrida; Rizzarelli, Enrico; Spina-Purrello, Vittoria

    2013-01-01

    Poly(ADP-ribose) polymerases (PARPs) are recognized as key regulators of cell survival or death. PARP-1 is essential to the repair of DNA single-strand breaks via the base excision repair pathway. The enzyme may be overactivated in response to inflammatory cues, thus depleting cellular energy pools and eventually causing cell death. Accordingly, PARP-1 inhibitors, acting by competing with its physiological substrate NAD(+), have been proposed to play a protective role in a wide range of inflammatory and ischemia/reperfusion-associated diseases. Recently, it has also been reported that PARP-1 regulates proinflammatory mediators, including cytokines, chemokines, adhesion molecules, and enzymes (e.g., iNOS). Furthermore, PARP-1 has been shown to act as a coactivator of NF-κB- and other transcription factors implicated in stress/inflammation, as AP-1, Oct-1, SP-1, HIF, and Stat-1. To further substantiate this hypothesis, we tested the biomolecular effects of PARP-1 inhibitors DPQ and PJ-34 on human glioblastoma cells, induced to a proinflammatory state with lipopolysaccharide and Interferon-γ. PARP-1 expression was evaluated by laser scanning confocal microscopy immunofluorescence (LSM); nitrite production, LDH release and cell viability were also determined. LSM of A-172, SNB-19 and CAS-1 cells demonstrated that DPQ and PJ-34 downregulate PARP-1 expression; they also cause a decrease of LDH release and nitrite production, while increasing cell viability. Similar effects were caused in all three cell lines by N-mono-methyl-arginine, a well known iNOS inhibitor, and by L-carnosine and trehalose, two antioxidant molecules. These results demonstrate that, similar to other well characterized drugs, DPQ and PJ-34 reduce cell inflammation and damage that follow PARP-1 overexpression, while they increase cell survival: this suggests their potential exploitation in clinical Medicine. PMID:23011206

  6. Morin Mitigates Chronic Constriction Injury (CCI)-Induced Peripheral Neuropathy by Inhibiting Oxidative Stress Induced PARP Over-Activation and Neuroinflammation.

    Science.gov (United States)

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

    2016-08-01

    Neuropathic pain is initiated or caused due to the primary lesion or dysfunction in the nervous system and is proposed to be linked to a cascade of events including excitotoxicity, oxidative stress, neuroinflammation and apoptosis. Oxidative/nitrosative stress aggravates the neuroinflammation and neurodegeneration through poly (ADP) ribose polymerase (PARP) overactivation. Hence, the present study investigated the antioxidant and anti-inflammatory effects of the phytoconstituent; morin in chronic constriction injury (CCI) induced neuropathy. Neuropathic pain was induced by chronic constriction of the left sciatic nerve in rats, and the effect of morin (15 and 30 mg/kg, p.o.) was evaluated by measuring behavioural and biochemical changes. Mechanical, chemical and thermal stimuli confirmed the CCI-induced neuropathic pain and treatment with morin significantly improved these behavioural deficits and improved the sciatic functional index by the 14th day after CCI induction. After 14 days of CCI induction, oxidative/nitrosative stress and inflammatory markers were elevated in rat lumbar spinal cord. Oxidative stress induced PARP overactivation resulted in depleted levels of ATP and elevated levels of poly (ADP) ribose (PAR). Treatment with morin reduced the levels of nitrites, restored glutathione levels and abrogated the oxidant induced DNA damage. It also mitigated the increased levels of TNF-α and IL-6. Protein expression studies confirmed the PARP inhibition and anti-inflammatory activity of morin. Findings of this study suggest that morin, by virtue of its antioxidant properties, limited PARP overactivation and neuroinflammation and protected against CCI induced functional, behavioural and biochemical deficits. PMID:27084773

  7. Detection and delineation of oral cancer with a PARP1 targeted optical imaging agent

    Science.gov (United States)

    Kossatz, Susanne; Brand, Christian; Gutiontov, Stanley; Liu, Jonathan T. C.; Lee, Nancy Y.; Gönen, Mithat; Weber, Wolfgang A.; Reiner, Thomas

    2016-01-01

    Earlier and more accurate detection of oral squamous cell carcinoma (OSCC) is essential to improve the prognosis of patients and to reduce the morbidity of surgical therapy. Here, we demonstrate that the nuclear enzyme Poly(ADP-ribose)Polymerase 1 (PARP1) is a promising target for optical imaging of OSCC with the fluorescent dye PARPi-FL. In patient-derived OSCC specimens, PARP1 expression was increased 7.8 ± 2.6-fold when compared to normal tissue. Intravenous injection of PARPi-FL allowed for high contrast in vivo imaging of human OSCC models in mice with a surgical fluorescence stereoscope and high-resolution imaging systems. The emitted signal was specific for PARP1 expression and, most importantly, PARPi-FL can be used as a topical imaging agent, spatially resolving the orthotopic tongue tumors in vivo. Collectively, our results suggest that PARP1 imaging with PARPi-FL can enhance the detection of oral cancer, serve as a screening tool and help to guide surgical resections. PMID:26900125

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

    Science.gov (United States)

    Benavente, Claudia A; Schnell, Stephanie A; Jacobson, Elaine L

    2012-01-01

    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. PMID:22860104

  9. Detection and delineation of oral cancer with a PARP1 targeted optical imaging agent.

    Science.gov (United States)

    Kossatz, Susanne; Brand, Christian; Gutiontov, Stanley; Liu, Jonathan T C; Lee, Nancy Y; Gönen, Mithat; Weber, Wolfgang A; Reiner, Thomas

    2016-01-01

    Earlier and more accurate detection of oral squamous cell carcinoma (OSCC) is essential to improve the prognosis of patients and to reduce the morbidity of surgical therapy. Here, we demonstrate that the nuclear enzyme Poly(ADP-ribose)Polymerase 1 (PARP1) is a promising target for optical imaging of OSCC with the fluorescent dye PARPi-FL. In patient-derived OSCC specimens, PARP1 expression was increased 7.8 ± 2.6-fold when compared to normal tissue. Intravenous injection of PARPi-FL allowed for high contrast in vivo imaging of human OSCC models in mice with a surgical fluorescence stereoscope and high-resolution imaging systems. The emitted signal was specific for PARP1 expression and, most importantly, PARPi-FL can be used as a topical imaging agent, spatially resolving the orthotopic tongue tumors in vivo. Collectively, our results suggest that PARP1 imaging with PARPi-FL can enhance the detection of oral cancer, serve as a screening tool and help to guide surgical resections. PMID:26900125

  10. Targeted radiosensitization of ETS fusion-positive prostate cancer through PARP1 inhibition.

    Science.gov (United States)

    Han, Sumin; Brenner, J Chad; Sabolch, Aaron; Jackson, Will; Speers, Corey; Wilder-Romans, Kari; Knudsen, Karen E; Lawrence, Theodore S; Chinnaiyan, Arul M; Feng, Felix Y

    2013-10-01

    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 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. PMID:24204199

  11. 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.

  12. PARP-1 expression in CD34+ leukemic cells in childhood acute lymphoblastic leukemia: relation to response to initial therapy and other prognostic factors.

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    Kruk, Agnieszka; Ociepa, Tomasz; Urasiński, Tomasz; Grabarek, Jerzy; Urasińska, Elzbieta

    2015-09-01

    Poly(ADP-ribose) polymerase-1 (PARP-1) is a nuclear protein that impacts DNA repair and apoptosis. Both experimental and ongoing clinical studies indicate that PARP-1 inhibitors are potent and promising anticancer agents. However, the outcome of treatment with PARP-1 inhibitors depends on the expression of PARP-1 protein in the tumor cells. This study aimed to assess PARP-1 expression in peripheral blood CD34+ leukemic cells before and after 12 hours of prednisone administration as well as the relation between PARP-1 expression and early treatment response to initial therapy and other prognostic factors (immunophenotype, age, initial peripheral blood white blood count [WBC], and risk factor group). The study comprised 43 children with de novo ALL. Cytospins of peripheral blood were stained with mouse anti-CD34-FITC and anti-PARP-1 antibody followed by goat anti-mouse APC-conjugated antibody. DNA was counterstained with PI (propidium iodide). Cellular fluorescence was measured by a laser scanning cytometer. Statistically significant differences in baseline PARP-1 expression with respect to early treatment response (good vs. poor), ALL immunophenotype (ALL B vs. ALL T), age (children 6 years vs. children 1-6 years), initial WBC (< 20 000/µl vs. ≥ 20 000/µl), and risk factor group (SR vs. IR vs. HR) were not found. PARP-1 expression was increased 12 hours after treatment in poor early treatment responders, whereas it remained statistically unchanged with respect to ALL immunophenotype, age, initial WBC, risk factor group and early treatment response. The overexpression of PARP-1 in poor early treatment responders suggests that it may contribute to treatment failure in this group of children with ALL. Our observation - if confirmed by other studies - may form the rationale for administration of PARP inhibitors in selected subsets of ALL children. PMID:26619102

  13. Association Between PARP1 Single Nucleotide Polymorphism and Brain Tumors.

    Science.gov (United States)

    Wang, Hong; Zhang, Kun; Qin, Haifeng; Yang, Lin; Zhang, Liyu; Cao, Yanyan

    2016-05-01

    To systematically evaluate the association between poly(ADP-ribose) polymerase 1 (PARP1) rs1136410 T>C and brain tumor risk, a meta-analysis has been carried out. We performed a meta-analysis of 2004 brain tumor patients and 2944 controls by use of STATA version 12.0 to determine whether the risk of brain tumors was associated with the genotypes or alleles of rs1136410 T>C. We found a significantly decreased risk (ranging from 0.18- to 0.16-fold) in the dominant model (OR = 0.84, 95 % CI = 0.75-0.95), the C vs. T model (OR = 0.82, 95 % CI = 0.74-0.91), and the CT vs. TT model (OR = 0.86, 95 % CI = 0.76-0.98). The same genetic models demonstrated noteworthy associations when analysis was restrained to glioma (OR = 0.85, 95 % CI = 0.75-0.96; OR = 0.83, 95 % CI = 0.74-0.92; OR = 0.87, 95 % CI = 0.76-0.99, respectively). This meta-analysis suggests that PARP1 rs1136410 T>C may play a significant role in the protection against the development of brain tumors and glioma. PMID:25911198

  14. 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

  15. Sensitization of prostate cancer to ionizing radiation by targeting poly(ADP-robose) polymerase: preclinical studies

    International Nuclear Information System (INIS)

    Poly(ADP-ribose) polymerase (PARP) is a DNA-binding enzyme which plays important roles in the maintenance of genome stability, immediate cellular responses to DNA damage, and apoptosis. A DNA-binding domain of PARP (PARP-DBD) acts as a dominant-negative mutant by binding to DNA strand breaks irreversibly and sensitizing mammalian cells to DNA-damaging agents (1, 2). To direct the expression of human PARP-DBD to prostate we developed recombinant plasmids expressing the PARP-DBD under the control of the 5'-flanking sequences of the human prostate-specific antigen (PSA) gene. In vitro studies revealed that PSA promoter driven expression of the PARP-DBD showed prostate tissue specificity and androgen responsiveness and sensitized LNCaP cells to DNA-damaging agents, such as ionizing radiation and etoposide (3). To assess the efficiency of this strategy in vivo, we developed a cationic liposome-mediated gene delivery of PARP-DBD plasmid in tumor xenografts of PSA producing and androgen sensitive prostate cancer cells (LNCaP and 22Rv1). Tumor bearing mice were treated with intratumoral liposome-complexed PARP-DBD (LE-PARP-DBD), ionizing radiation (IR) or a combination of LE-PARP-DBD and IR. Control groups received blank liposomes or were left untreated. Administration of LE-PARP-DBD resulted in expression of dominant-negative mutant of PARP in tumor cells and enhanced radiation-induced inhibition of tumor growth. These results provide a proof-of- principle for a novel therapeutic strategy to control prostate cancer. The study was supported in part by grants from the U.S. Army Medical Research and Development Command DAMD 17-00-1-0019 and DAMD 17-00-1-0276 (to V.S.). (1) J.Biol.Chem., 265:18721-18724, 1990; (2) Cancer Research, 58: 3495-3498, 1998; (3) Cancer Research, 62: 6879-6883, 2002

  16. Low concentration of arsenite exacerbates UVR-induced DNA strand breaks by inhibiting PARP-1 activity

    International Nuclear Information System (INIS)

    Epidemiological studies have associated arsenic exposure with many types of human cancers. Arsenic has also been shown to act as a co-carcinogen even at low concentrations. However, the precise mechanism of its co-carcinogenic action is unknown. Recent studies indicate that arsenic can interfere with DNA-repair processes. Poly(ADP-ribose) polymerase (PARP)-1 is a zinc-finger DNA-repair protein, which can promptly sense DNA strand breaks and initiate DNA-repair pathways. In the present study, we tested the hypothesis that low concentrations of arsenic could inhibit PAPR-1 activity and so exacerbate levels of ultraviolet radiation (UVR)-induced DNA strand breaks. HaCat cells were treated with arsenite and/or UVR, and then DNA strand breaks were assessed by comet assay. Low concentrations of arsenite (≤ 2 μM) alone did not induce significant DNA strand breaks, but greatly enhanced the DNA strand breaks induced by UVR. Further studies showed that 2 μM arsenite effectively inhibited PARP-1 activity. Zinc supplementation of arsenite-treated cells restored PARP-1 activity and significantly diminished the exacerbating effect of arsenite on UVR-induced DNA strand breaks. Importantly, neither arsenite treatment, nor zinc supplementation changed UVR-triggered reactive oxygen species (ROS) formation, suggesting that their effects upon UVR-induced DNA strand breaks are not through a direct free radical mechanism. Combination treatments of arsenite with PARP-1 inhibitor 3-aminobenzamide or PARP-1 siRNA demonstrate that PARP-1 is the target of arsenite. Together, these findings show that arsenite at low concentration exacerbates UVR-induced DNA strand breaks by inhibiting PARP-1 activity, which may represent an important mechanism underlying the co-carcinogenicity of arsenic

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

    International Nuclear Information System (INIS)

    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)

  18. Poly(ADP-ribose) synthesis following DNA damage in cells heterozygous or homozygous for the xeroderma pigmentosum genotype

    International Nuclear Information System (INIS)

    Treatment of normal human cells with DNA-damaging agents such as uv light or N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) stimulates the conversion of NAD to the chromosomal polymer poly(ADP-ribose) which in turn results in a rapid depletion of the cellular NAD pool. The effect of uv light or MNNG on the NAD pools of seven cell lines of human fibroblasts either homozygous or heterozygous for the xeroderma pigmentosum genotype has been studied. Xeroderma pigmentosum cells of genetic complementation groups A, C, and D are deficient in the excision repair of DNA damage caused by uv light. Following uv treatment, the NAD content of these cells was unchanged or only slightly reduced. All of the cell lines are able to excise DNA damage caused by MNNG and all of the cell lines had a greatly reduced content of NAD following MNNG treatment. The results demonstrate a close relationship between the conversion of NAD to poly(ADP-ribose) and DNA excision repair in human cells

  19. Silencing of poly(ADP-ribose) glycohydrolase sensitizes lung cancer cells to radiation through the abrogation of DNA damage checkpoint

    Energy Technology Data Exchange (ETDEWEB)

    Nakadate, Yusuke [Shien-Lab, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Department of Bioengineering, Graduate School of Engineering, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585 (Japan); Kodera, Yasuo; Kitamura, Yuka [Shien-Lab, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Tachibana, Taro [Department of Bioengineering, Graduate School of Engineering, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585 (Japan); Tamura, Tomohide [Division of Thoracic Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Koizumi, Fumiaki, E-mail: fkoizumi@ncc.go.jp [Division of Thoracic Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan)

    2013-11-29

    Highlights: •Radiosensitization by PARG silencing was observed in multiple lung cancer cells. •PAR accumulation was enhanced by PARG silencing after DNA damage. •Radiation-induced G2/M arrest and checkpoint activation were impaired by PARG siRNA. -- Abstract: Poly(ADP-ribose) glycohydrolase (PARG) is a major enzyme that plays a role in the degradation of poly(ADP-ribose) (PAR). PARG deficiency reportedly sensitizes cells to the effects of radiation. In lung cancer, however, it has not been fully elucidated. Here, we investigated whether PARG siRNA contributes to an increased radiosensitivity using 8 lung cancer cell lines. Among them, the silencing of PARG induced a radiosensitizing effect in 5 cell lines. Radiation-induced G2/M arrest was largely suppressed by PARG siRNA in PC-14 and A427 cells, which exhibited significantly enhanced radiosensitivity in response to PARG knockdown. On the other hand, a similar effect was not observed in H520 cells, which did not exhibit a radiosensitizing effect. Consistent with a cell cycle analysis, radiation-induced checkpoint signals were not well activated in the PC-14 and A427 cells when treated with PARG siRNA. These results suggest that the increased sensitivity to radiation induced by PARG knockdown occurs through the abrogation of radiation-induced G2/M arrest and checkpoint activation in lung cancer cells. Our findings indicate that PARG could be a potential target for lung cancer treatments when used in combination with radiotherapy.

  20. Protective effects of PARP-1 knockout on dyslipidemia-induced autonomic and vascular dysfunction in ApoE mice: effects on eNOS and oxidative stress.

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    Chetan P Hans

    Full Text Available The aims of this study were to investigate the role of poly(ADP-ribose polymerase (PARP-1 in dyslipidemia-associated vascular dysfunction as well as autonomic nervous system dysregulation. Apolipoprotein (ApoE(-/- mice fed a high-fat diet were used as a model of atherosclerosis. Vascular and autonomic functions were measured in conscious mice using telemetry. The study revealed that PARP-1 plays an important role in dyslipidemia-associated vascular and autonomic dysfunction. Inhibition of this enzyme by gene knockout partially restored baroreflex sensitivity in ApoE(-/- mice without affecting baseline heart-rate and arterial pressure, and also improved heart-rate responses following selective blockade of the autonomic nervous system. The protective effect of PARP-1 gene deletion against dyslipidemia-induced endothelial dysfunction was associated with preservation of eNOS activity. Dyslipidemia induced PARP-1 activation was accompanied by oxidative tissue damage, as evidenced by increased expression of iNOS and subsequent protein nitration. PARP-1 gene deletion reversed these effects, suggesting that PARP-1 may contribute to vascular and autonomic pathologies by promoting oxidative tissue injury. Further, inhibition of this oxidative damage may account for protective effects of PARP-1 gene deletion on vascular and autonomic functions. This study demonstrates that PARP-1 participates in dyslipidemia-mediated dysregulation of the autonomic nervous system and that PARP-1 gene deletion normalizes autonomic and vascular dysfunctions. Maintenance of eNOS activity may be associated with the protective effect of PARP-1 gene deletion against dyslipidemia-induced endothelial dysfunction.

  1. Interaction of PARP2 with DNA structures mimicking DNA repair intermediates

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    Lavrik O. I.

    2011-10-01

    Full Text Available Poly(ADP-ribosylation is a posttranslational protein modification significant for the genomic stability and cell survival in response to DNA damage. Poly(ADP-ribosylation is catalyzed by poly(ADP-ribosepolymerases (PARPs. Whereas the role of PARP1 in response to DNA damage has been widely illustrated, the contribution of another DNA-dependent PARP, PARP2, has not been studied so far. Aim. To find out specific DNA targets of PARP2. Methods. The EMSA and the PARP activity tests were used. Results. We evaluated Kd values of PARP2-DNA complexes for several DNA structures mimicking intermediates of different DNA metabolizing processes and tested these DNA as «activators» of PARP1 and PARP2 in poly(ADP-ribose synthesis. Conclusions. Like PARP1, PARP2 does not show correlation between the activation efficiency and Kd values for DNA. PARP2 was activated most effectively in the presence of over5DNA.

  2. PARP inhibition attenuates early brain injury through NF-κB/MMP-9 pathway in a rat model of subarachnoid hemorrhage.

    Science.gov (United States)

    Chen, Ting; Wang, Wei; Li, Jian-Ru; Xu, Hang-Zhe; Peng, Yu-Cong; Fan, Lin-Feng; Yan, Feng; Gu, Chi; Wang, Lin; Chen, Gao

    2016-08-01

    Poly (ADP-ribose) polymerases (PARPs) play an important role in a range of neurological disorders, however, the role of PARP in early brain injury after subarachnoid hemorrhage (SAH) remains unclear. This study was designed to explore the role and the potential mechanisms of PARP in early brain injury after SAH. Eighty-nine male SD rats were randomly divided into the Sham group, SAH+Vehicle group and SAH+PARP inhibitor (PJ34) group. An endovascular perforation model was used to induce SAH in rats. PJ34 (10mg/kg) or vehicle (0.9% NaCl) was intraperitoneally administered at 5min and 8h after SAH induction. Mortality, SAH grades, neurological function, evans blue extravasation, brain edema, immunofluorescence staining and western blotting were performed. PJ34 reduced BBB permeability and brain edema, improved neurological function and attenuated neuronal cell death in the rat model of SAH. Moreover, PJ34 inhibited the nuclear translocation of NF-κB, decreased the expression of the proinflammatory cytokines IL-1ß, IL-6 and TNF-α, reduced the expression of MMP-9, prevented the degradation of tight junction proteins, and decreased microglia activation. These data indicated that PARP inhibition through PJ34 might be an important therapeutic drug for SAH. PMID:27157545

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

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    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.

  4. Roles of PARP inhibitor in synthetic lethality and as a sensitizer in cancer therapy

    International Nuclear Information System (INIS)

    In a search for novel chemotherapeutic targets for cancer, recent interest has focused on DNA repair pathways. Poly (ADP-ribose) polymerase (PARP)-1 is an important protein for base excision repair and inhibitors of this pathway show anti-cancer effects when used as a mono-therapy for BRCA-deficient cancers in clinical trials. The results of such studies proved the concept of ''synthetic lethality'' by targeting DNA repair pathways. Considering the action of the PARP inhibitor (PARPi) in DNA repair pathways, PARPi is also predicted to act as a sensitizer for DNA damaging agents, such as certain chemotherapeutic drugs and radiation. A number of clinical trials using PARPi in combination with existing therapies are underway. We investigated the use of PARPi as a radiosensitizer for high LET (linear energy transfer) radiation. PARPi showed the radiosensitization effect of carbon-ion radiation, and the radiosensitization effect of PARPi was attributed to a delay in the DNA damage response and double strand break processing. Via its effects on DNA repair, the PARP inhibitor might be applicable as a radiosensitizer for a wide range of therapeutic LET radiation. This study suggests that development of research into DNA repair pathways could yield still further targets for cancer therapy. (author)

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

    Science.gov (United States)

    Hirai, Takahisa; Saito, Soichiro; Fujimori, Hiroaki; Matsushita, Keiichiro; Nishio, Teiji; Okayasu, Ryuichi; Masutani, Mitsuko

    2016-09-01

    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. PMID:27425251

  6. 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.

  7. 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. PMID:27427773

  8. PARP-1 Val762Ala polymorphism is associated with reduced risk of non-Hodgkin lymphoma in Korean males

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    Kim Hyeoung-Joon

    2010-03-01

    Full Text Available Abstract Background Poly(ADP-ribose polymerase-1 (PARP-1 is a nuclear enzyme that plays a role in DNA repair, differentiation, proliferation, and cell death. The polymorphisms of PARP-1 have been associated with the risk of various carcinomas, including breast, lung, and prostate. We investigated whether PARP-1 polymorphisms are associated with the risk of non-Hodgkin lymphoma (NHL. Methods Subjects from a Korean population consisting of 573 NHL patients and 721 controls were genotyped for 5 PARP-1 polymorphisms (Asp81Asp, Ala284Ala, Lys352Lys, IVS13+118A>G, and Val762Ala using High Resolution Melting polymerase chain reaction (PCR and an automatic sequencer. Results None of the 5 polymorphisms were associated with overall risk for NHL. However, the Val762Ala polymorphism was associated with reduced risk for NHL in males [odds ratio (OR, 0.62; 95% confidence interval (CI, 0.41-0.93 for CC genotype and OR, 0.84; 95% CI, 0.60-1.16 for TC genotype] with a trend toward a gene dose effect (p for trend, 0.02. The Asp81Asp (p for trend, 0.04 and Lys352Lys (p for trend, 0.03 polymorphisms revealed the same trend. In an association study of PARP-1 haplotypes, the haplotype-ACAAC was associated with decreased risk of NHL in males (OR, 0.75; 95% CI, 0.59-0.94. Conclusion The present data suggest that Val762Ala, Asp81Asp, and Lys352Lys polymorphisms and the haplotype-ACAAC in PARP-1 are associated with reduced risk of NHL in Korean males.

  9. Cordycepin induces apoptosis of C6 glioma cells through the adenosine 2A receptor-p53-caspase-7-PARP pathway.

    Science.gov (United States)

    Chen, Ying; Yang, Shih-Hung; Hueng, Dueng-Yuan; Syu, Jhih-Pu; Liao, Chih-Chen; Wu, Ya-Chieh

    2014-06-01

    Cordycepin, 3'-deoxyadenosine from Cordyceps sinensis, has been shown to exert anti-tumor effects in several cancer cell lines. This study investigated the effect of cordycepin on a rat glioma cell line. Cordycepin caused apoptosis in C6 glioma cells in a time- and concentration-dependent manner, but did not affect the survival of primary cultured rat astrocytes. Cordycepin increased the total protein levels of p53 and phosphorylated p53 in the C6 cells. Levels of cleaved caspase-7 and poly (ADP-ribose) polymerase (PARP), but not cleaved caspase-3, were also increased after cordycepin treatment. Specific inhibitors for p53 and caspases abrogated cordycepin-induced caspase-7 and PARP cleavage, and prevented cordycepin-induced apoptosis. Moreover, siRNA knockdown of p53 blocked cordycepin-induced cleavage of caspase-7 and PARP. Both adenosine 2A receptor (A2AR) antagonist and small interference RNA (siRNA) knockdown of A2AR blocked cordycepin-induced apoptosis, p53 activation, and caspase-7 and PARP cleavage. These may provide a new strategy of cordycepin for glioma therapy in the future. PMID:24704558

  10. Nuclear ULK1 promotes cell death in response to oxidative stress through PARP1.

    Science.gov (United States)

    Joshi, A; Iyengar, R; Joo, J H; Li-Harms, X J; Wright, C; Marino, R; Winborn, B J; Phillips, A; Temirov, J; Sciarretta, S; Kriwacki, R; Peng, J; Shelat, A; Kundu, M

    2016-02-01

    Reactive oxygen species (ROS) may cause cellular damage and oxidative stress-induced cell death. Autophagy, an evolutionarily conserved intracellular catabolic process, is executed by autophagy (ATG) proteins, including the autophagy initiation kinase Unc-51-like kinase (ULK1)/ATG1. Although autophagy has been implicated to have both cytoprotective and cytotoxic roles in the response to ROS, the role of individual ATG proteins, including ULK1, remains poorly characterized. In this study, we demonstrate that ULK1 sensitizes cells to necrotic cell death induced by hydrogen peroxide (H2O2). Moreover, we demonstrate that ULK1 localizes to the nucleus and regulates the activity of the DNA damage repair protein poly (ADP-ribose) polymerase 1 (PARP1) in a kinase-dependent manner. By enhancing PARP1 activity, ULK1 contributes to ATP depletion and death of H2O2-treated cells. Our study provides the first evidence of an autophagy-independent prodeath role for nuclear ULK1 in response to ROS-induced damage. On the basis of our data, we propose that the subcellular distribution of ULK1 has an important role in deciding whether a cell lives or dies on exposure to adverse environmental or intracellular conditions. PMID:26138443

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

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    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.

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

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    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.

  13. The proposed channel-enzyme transient receptor potential melastatin 2 does not possess ADP ribose hydrolase activity.

    Science.gov (United States)

    Iordanov, Iordan; Mihályi, Csaba; Tóth, Balázs; Csanády, László

    2016-01-01

    Transient Receptor Potential Melastatin 2 (TRPM2) is a Ca(2+)-permeable cation channel essential for immunocyte activation, insulin secretion, and postischemic cell death. TRPM2 is activated by ADP ribose (ADPR) binding to its C-terminal cytosolic NUDT9-homology (NUDT9H) domain, homologous to the soluble mitochondrial ADPR pyrophosphatase (ADPRase) NUDT9. Reported ADPR hydrolysis classified TRPM2 as a channel-enzyme, but insolubility of isolated NUDT9H hampered further investigations. Here we developed a soluble NUDT9H model using chimeric proteins built from complementary polypeptide fragments of NUDT9H and NUDT9. When expressed in E.coli, chimeras containing up to ~90% NUDT9H sequence remained soluble and were affinity-purified. In ADPRase assays the conserved Nudix-box sequence of NUDT9 proved essential for activity (kcat~4-9s(-1)), that of NUDT9H did not support catalysis. Replacing NUDT9H in full-length TRPM2 with soluble chimeras retained ADPR-dependent channel gating (K1/2~1-5 μM), confirming functionality of chimeric domains. Thus, TRPM2 is not a 'chanzyme'. Chimeras provide convenient soluble NUDT9H models for structural/biochemical studies. PMID:27383051

  14. Trypanosoma cruzi Induces the Reactive Oxygen Species-PARP-1-RelA Pathway for Up-regulation of Cytokine Expression in Cardiomyocytes*

    OpenAIRE

    Ba, Xueqing; Gupta, Shivali; Davidson, Mercy; Garg, Nisha Jain

    2010-01-01

    In this study, we demonstrate that human cardiomyocytes (AC16) produce reactive oxygen species (ROS) and inflammatory cytokines in response to Trypanosoma cruzi. ROS were primarily produced by mitochondria, some of which diffused to cytosol of infected cardiomyocytes. These ROS resulted in an increase in 8-hydroxyguanine lesions and DNA fragmentation that signaled PARP-1 activation evidenced by poly(ADP-ribose) (PAR) modification of PARP-1 and other proteins in infected cardiomyocytes. Phenyl...

  15. Aryl Hydrocarbon Receptor Repressor and TiPARP (ARTD14 Use Similar, but also Distinct Mechanisms to Repress Aryl Hydrocarbon Receptor Signaling

    Directory of Open Access Journals (Sweden)

    Laura MacPherson

    2014-05-01

    Full Text Available The aryl hydrocarbon receptor (AHR regulates the toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD. The AHR repressor (AHRR is an AHR target gene and functions as a ligand-induced repressor of AHR; however, its mechanism of inhibition is controversial. Recently, we reported that TCDD-inducible poly (ADP-ribose polymerase (TiPARP; ARTD14 also acts as a repressor of AHR, representing a new player in the mechanism of AHR action. Here we compared the ability of AHRR- and TiPARP-mediated inhibition of AHR activity. TCDD increased AHRR mRNA levels and recruitment of AHRR to cytochrome P450 1A1 (CYP1A1 in MCF7 cells. Knockdown of TiPARP, but not AHRR, increased TCDD-induced CYP1A1 mRNA and AHR protein levels. Similarly, immortalized TiPARP−/− mouse embryonic fibroblasts (MEFs and AHRR−/− MEFs exhibited enhanced AHR transactivation. However, unlike TiPARP−/− MEFs, AHRR−/− MEFs did not exhibit increased AHR protein levels. Overexpression of TiPARP in AHRR−/− MEFs or AHRRΔ8, the active isoform of AHRR, in TiPARP−/− MEFs reduced TCDD-induced CYP1A1 mRNA levels, suggesting that they independently repress AHR. GFP-AHRRΔ8 and GFP-TiPARP expressed as small diffuse nuclear foci in MCF7 and HuH7 cells. GFP-AHRRΔ8_Δ1-49, which lacks its putative nuclear localization signal, localized to both the nucleus and the cytoplasm, while the GFP-AHRRΔ8_Δ1-100 mutant localized predominantly in large cytoplasmic foci. Neither GFP-AHRRΔ8_Δ1-49 nor GFP-AHRRΔ8_Δ1-100 repressed AHR. Taken together, AHRR and TiPARP repress AHR transactivation by similar, but also different mechanisms.

  16. Structure of spinach acetohydroxyacid isomeroreductase complexed with its reaction product dihydroxymethylvalerate, manganese and (phospho)-ADP-ribose.

    Science.gov (United States)

    Thomazeau, K; Dumas, R; Halgand, F; Forest, E; Douce, R; Biou, V

    2000-04-01

    Acetohydroxyacid isomeroreductase catalyses a two-step reaction composed of an alkyl migration followed by an NADPH-dependent reduction. Both steps require a divalent cation and the first step has a strong preference for magnesium. Manganese ions are highly unfavourable to the reaction: only 3% residual activity is observed in the presence of this cation. Acetohydroxyacid isomeroreductase has been crystallized with its substrate, 2-aceto-2-hydroxybutyrate (AHB), Mn(2+) and NADPH. The 1.6 A resolution electron-density map showed the reaction product (2,3-dihydroxy-3-methylvalerate, DHMV) and a density corresponding to (phospho)-ADP-ribose instead of the whole NADP(+). This is one of the few structures of an enzyme complexed with its reaction product. The structure of this complex was refined to an R factor of 19.3% and an R(free) of 22.5%. The overall structure of the enzyme is very similar to that of the complex with the reaction-intermediate analogue IpOHA [N-hydroxy-N-isopropyloxamate; Biou et al. (1997), EMBO J. 16, 3405-3415]. However, the active site shows some differences: the nicotinamide is cleaved and the surrounding amino acids have rearranged accordingly. Comparison between the structures corresponding to the reaction intermediate and to the end of the reaction allowed the proposal of a reaction scheme. Taking this result into account, the enzyme was crystallized with Ni(2+) and Zn(2+), for which only 0.02% residual activity were measured; however, the crystals of AHB/Zn/NADPH and of AHB/Ni/NADPH also contain the reaction product. Moreover, mass-spectrometry measurements confirmed the -cleavage of nicotinamide. PMID:10739911

  17. Characterization of Danio rerio Mn2+-dependent ADP-ribose/CDP-alcohol diphosphatase, the structural prototype of the ADPRibase-Mn-like protein family.

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    Joaquim Rui Rodrigues

    Full Text Available The ADPRibase-Mn-like protein family, that belongs to the metallo-dependent phosphatase superfamily, has different functional and structural prototypes. The functional one is the Mn(2+-dependent ADP-ribose/CDP-alcohol diphosphatase from Rattus norvegicus, which is essentially inactive with Mg(2+ and active with low micromolar Mn(2+ in the hydrolysis of the phosphoanhydride linkages of ADP-ribose, CDP-alcohols and cyclic ADP-ribose (cADPR in order of decreasing efficiency. The structural prototype of the family is a Danio rerio protein with a known crystallographic structure but functionally uncharacterized. To estimate the structure-function correlation with the same protein, the activities of zebrafish ADPRibase-Mn were studied. Differences between zebrafish and rat enzymes are highlighted. The former showed a complex activity dependence on Mn(2+, significant (≈25% Mg(2+-dependent activity, but was almost inactive on cADPR (150-fold less efficient than the rat counterpart. The low cADPR hydrolase activity agreed with the zebrafish genome lacking genes coding for proteins with significant homology with cADPR-forming enzymes. Substrate-docking to zebrafish wild-type protein, and characterization of the ADPRibase-Mn H97A mutant pointed to a role of His-97 in catalysis by orientation, and to a bidentate water bridging the dinuclear metal center as the potential nucleophile. Finally, three structural elements that delimit the active site entrance in the zebrafish protein were identified as unique to the ADPRibase-Mn-like family within the metallo-dependent phosphatase superfamily.

  18. Impact of PARP-1 and DNA-PK expression on survival in patients with glioblastoma multiforme

    International Nuclear Information System (INIS)

    Purpose: To analyze, whether higher tumor levels of DNA repair enzymes contribute to worse treatment results of glioblastoma multiforme (GBM) patients after postoperative radiotherapy. Materials and methods: Thirty four patients with GBM received postoperative radiotherapy. Tumor sections were examined for poly-ADP ribose polymerase-1 (PARP-1) and DNA protein kinase (DNA-PK) expression. Immunohistochemical staining intensities of PARP-1 and DNA-PK were determined (score 0–3) and expression levels were correlated with patients overall survival. Results: Median survival time of the whole study group was 10.0 months (95% CI 8.1–11.9). Median survival of patients with high and low (⩾median and < median) tumor PARP-1 levels were 10.0 months (95% CI 7.9–12.1) and 12.0 months (95% CI 8.3–15.7), respectively (p = 0.93). In contrast, median survival of patients with high and low tumor DNA-PK levels were 9.0 months (95% CI 7.2–10.8) and 13.0 months (95% CI 10.7–15.3), respectively (p = 0.02). In multivariate analysis, DNA-PK expression emerged as a significant independent predictor for overall survival (HR 3.9, 95% CI 1.5–10.7, p = 0.01). Conclusion: This hypothesis generating study showed that high tumor levels of DNA-PK correlate with poor survival of GBM patients. Further studies are needed to confirm these results and to clarify whether DNA-PK inhibitors might have a potential to radiosensitize GBM and improve the treatment outcome of this devastating disease.

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

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    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.

  20. Single molecule detection of PARP1 and PARP2 interaction with DNA strand breaks and their poly(ADP-ribosyl)ation using high-resolution AFM imaging.

    Science.gov (United States)

    Sukhanova, Maria V; Abrakhi, Sanae; Joshi, Vandana; Pastre, David; Kutuzov, Mikhail M; Anarbaev, Rashid O; Curmi, Patrick A; Hamon, Loic; Lavrik, Olga I

    2016-04-01

    PARP1 and PARP2 are implicated in the synthesis of poly(ADP-ribose) (PAR) after detection of DNA damage. The specificity of PARP1 and PARP2 interaction with long DNA fragments containing single- and/or double-strand breaks (SSBs and DSBs) have been studied using atomic force microscopy (AFM) imaging in combination with biochemical approaches. Our data show that PARP1 localizes mainly on DNA breaks and exhibits a slight preference for nicks over DSBs, although the protein has a moderately high affinity for undamaged DNA. In contrast to PARP1, PARP2 is mainly detected at a single DNA nick site, exhibiting a low level of binding to undamaged DNA and DSBs. The enhancement of binding affinity of PARP2 for DNA containing a single nick was also observed using fluorescence titration. AFM studies reveal that activation of both PARPs leads to the synthesis of highly branched PAR whose size depends strongly on the presence of SSBs and DSBs for PARP1 and of SSBs for PARP2. The initial affinity between the PARP1, PARP2 and the DNA damaged site appears to influence both the size of the PAR synthesized and the time of residence of PARylated PARP1 and PARP2 on DNA damages. PMID:26673720

  1. 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

  2. APR-246 (PRIMA-1(MET)) strongly synergizes with AZD2281 (olaparib) induced PARP inhibition to induce apoptosis in non-small cell lung cancer cell lines.

    Science.gov (United States)

    Deben, Christophe; Lardon, Filip; Wouters, An; Op de Beeck, Ken; Van den Bossche, Jolien; Jacobs, Julie; Van Der Steen, Nele; Peeters, Marc; Rolfo, Christian; Deschoolmeester, Vanessa; Pauwels, Patrick

    2016-06-01

    APR-246 (PRIMA-1(Met)) is able to bind mutant p53 and restore its normal conformation and function. The compound has also been shown to increase intracellular ROS levels. Importantly, the poly-[ADP-ribose] polymerase-1 (PARP-1) enzyme plays an important role in the repair of ROS-induced DNA damage. We hypothesize that by blocking this repair with the PARP-inhibitor AZD2281 (olaparib), DNA damage would accumulate in the cell leading to massive apoptosis. We observed that APR-246 synergistically enhanced the cytotoxic response of olaparib in TP53 mutant non-small cell lung cancer cell lines, resulting in a strong apoptotic response. In the presence of wild type p53 a G2/M cell cycle block was predominantly observed. NOXA expression levels were significantly increased in a TP53 mutant background, and remained unchanged in the wild type cell line. The combined treatment of APR-246 and olaparib induced cell death that was associated with increased ROS production, accumulation of DNA damage and translocation of p53 to the mitochondria. Out data suggest a promising targeted combination strategy in which the response to olaparib is synergistically enhanced by the addition of APR-246, especially in a TP53 mutant background. PMID:26975633

  3. AcEST: DK961662 [AcEST

    Lifescience Database Archive (English)

    Full Text Available ASQLKGFSLLSAEDKE 193 >sp|P31669|PARP1_XENLA Poly [ADP-ribose] polymerase (Fragment) OS=Xenopus laevis GN=parp1... to vertebrate ADP-r... 79 4e-18 tr|Q2NLA7|Q2NLA7_XENLA PARP protein OS=Xenopus laevis GN=parp1 P... 7... (NAD+; poly (ADP-ribose) polymerase) (ADPRT) OS=Danio rerio GN=parp1 PE=4 SV=1 L...008|PARP1_RAT Poly [ADP-ribose] polymerase 1 OS=Rattus norvegicus GN=Parp1 PE=2 S..._MOUSE Poly [ADP-ribose] polymerase 1 OS=Mus musculus GN=Parp1 PE=1 SV=3 Length =

  4. PARP Inhibitors in Clinical Use Induce Genomic Instability in Normal Human Cells

    Science.gov (United States)

    Ito, Shuhei; Murphy, Conleth G.; Doubrovina, Ekaterina; Jasin, Maria; Moynahan, Mary Ellen

    2016-01-01

    Poly(ADP-ribose) polymerases (PARPs) are the first proteins involved in cellular DNA repair pathways to be targeted by specific inhibitors for clinical benefit. Tumors harboring genetic defects in homologous recombination (HR), a DNA double-strand break (DSB) repair pathway, are hypersensitive to PARP inhibitors (PARPi). Early phase clinical trials with PARPi have been promising in patients with advanced BRCA1 or BRCA2-associated breast, ovary and prostate cancer and have led to limited approval for treatment of BRCA-deficient ovary cancer. Unlike HR-defective cells, HR-proficient cells manifest very low cytotoxicity when exposed to PARPi, although they mount a DNA damage response. However, the genotoxic effects on normal human cells when agents including PARPi disturb proficient cellular repair processes have not been substantially investigated. We quantified cytogenetic alterations of human cells, including primary lymphoid cells and non-tumorigenic and tumorigenic epithelial cell lines, exposed to PARPi at clinically relevant doses by both sister chromatid exchange (SCE) assays and chromosome spreading. As expected, both olaparib and veliparib effectively inhibited poly-ADP-ribosylation (PAR), and caused marked hypersensitivity in HR-deficient cells. Significant dose-dependent increases in SCEs were observed in normal and non-tumorigenic cells with minimal residual PAR activity. Clinically relevant doses of the FDA-approved olaparib led to a marked increase of SCEs (5-10-fold) and chromatid aberrations (2-6-fold). Furthermore, olaparib potentiated SCE induction by cisplatin in normal human cells. Our data have important implications for therapies with regard to sustained genotoxicity to normal cells. Genomic instability arising from PARPi warrants consideration, especially if these agents will be used in people with early stage cancers, in prevention strategies or for non-oncologic indications. PMID:27428646

  5. Design, Synthesis, and Chemical and Biological Properties of Cyclic ADP-4-Thioribose as a Stable Equivalent of Cyclic ADP-Ribose

    Science.gov (United States)

    Tsuzuki, Takayoshi; Takano, Satoshi; Sakaguchi, Natsumi; Kudoh, Takashi; Murayama, Takashi; Sakurai, Takashi; Hashii, Minako; Higashida, Haruhiro; Weber, Karin; Guse, Andreas H.; Kameda, Tomoshi; Hirokawa, Takatsugu; Kumaki, Yasuhiro; Arisawa, Mitsuhiro; Potter, Barry V. L.; Shuto, Satoshi

    2016-01-01

    Here we describe the successful synthesis of cyclic ADP-4-thioribose (cADPtR, 3), designed as a stable mimic of cyclic ADP-ribose (cADPR, 1), a Ca2+-mobilizing second messenger, in which the key N1-β-thioribosyladenosine structure was stereoselectively constructed by condensation between the imidazole nucleoside derivative 8 and the 4-thioribosylamine 7 via equilibrium in 7 between the α-anomer (7α) and the β-anomer (7β) during the reaction course. cADPtR is, unlike cADPR, chemically and biologically stable, while it effectively mobilizes intracellular Ca2+ like cADPR in various biological systems, such as sea urchin homogenate, NG108-15 neuronal cells, and Jurkat T-lymphocytes. Thus, cADPtR is a stable equivalent of cADPR, which can be useful as a biological tool for investigating cADPR-mediated Ca2+-mobilizing pathways.

  6. Poly (ADP-ribose) synthetase inhibitor has a heart protective effect in a rat model of experimental sepsis

    OpenAIRE

    Zhang, Lianshuang; Yao, Jinpeng; Wang, Xifeng; Li, Hongxing; Liu, Tongshen; Zhao, Wei

    2015-01-01

    The aim of this study is to investigate whether PARP inhibitor could reduce cell apoptosis and injury in the heart during sepsis. Materials and methods: 60 healthy male Sprague-Dawley (SD) rats were randomly divided into 4 groups---sham group, modal group, 3-AB pretreatment group and 3-AB treatment group, 15 rats per group. The cecal ligation and puncture (CLP) model of sepsis was used. The following were determined--levels of malondialdehyde (MDA), ATP and nicotinamide adenine dinucleotide (...

  7. The formation of vault-tubes: a dynamic interaction between vaults and vault PARP

    OpenAIRE

    Zon, Arend; Mossink, Marieke; Schoester, Martijn; Houtsmuller, Adriaan; Scheffer, George; Scheper, Rik; Sonneveld, Pieter; Wiemer, Erik

    2003-01-01

    textabstractVaults are barrel-shaped cytoplasmic ribonucleoprotein particles that are composed of a major vault protein (MVP), two minor vault proteins [telomerase-associated protein 1 (TEP1), vault poly(ADP-ribose) polymerase (VPARP)] and small untranslated RNA molecules. Not all expressed TEP1 and VPARP in cells is bound to vaults. TEP1 is known to associate with the telomerase complex, whereas VPARP is also present in the nuclear matrix and in cytoplasmic clusters (VPARP-rods). We examined...

  8. Parp1 localizes within the Dnmt1 promoter and protects its unmethylated state by its enzymatic activity.

    Directory of Open Access Journals (Sweden)

    Michele Zampieri

    Full Text Available BACKGROUND: Aberrant hypermethylation of CpG islands in housekeeping gene promoters and widespread genome hypomethylation are typical events occurring in cancer cells. The molecular mechanisms behind these cancer-related changes in DNA methylation patterns are not well understood. Two questions are particularly important: (i how are CpG islands protected from methylation in normal cells, and how is this protection compromised in cancer cells, and (ii how does the genome-wide demethylation in cancer cells occur. The latter question is especially intriguing since so far no DNA demethylase enzyme has been found. METHODOLOGY/PRINCIPAL FINDINGS: Our data show that the absence of ADP-ribose polymers (PARs, caused by ectopic over-expression of poly(ADP-ribose glycohydrolase (PARG in L929 mouse fibroblast cells leads to aberrant methylation of the CpG island in the promoter of the Dnmt1 gene, which in turn shuts down its transcription. The transcriptional silencing of Dnmt1 may be responsible for the widespread passive hypomethylation of genomic DNA which we detect on the example of pericentromeric repeat sequences. Chromatin immunoprecipitation results show that in normal cells the Dnmt1 promoter is occupied by poly(ADP-ribosylated Parp1, suggesting that PARylated Parp1 plays a role in protecting the promoter from methylation. CONCLUSIONS/SIGNIFICANCE: In conclusion, the genome methylation pattern following PARG over-expression mirrors the pattern characteristic of cancer cells, supporting our idea that the right balance between Parp/Parg activities maintains the DNA methylation patterns in normal cells. The finding that in normal cells Parp1 and ADP-ribose polymers localize on the Dnmt1 promoter raises the possibility that PARylated Parp1 marks those sequences in the genome that must remain unmethylated and protects them from methylation, thus playing a role in the epigenetic regulation of gene expression.

  9. JNK Phosphorylates SIRT6 to Stimulate DNA Double-Strand Break Repair in Response to Oxidative Stress by Recruiting PARP1 to DNA Breaks.

    Science.gov (United States)

    Van Meter, Michael; Simon, Matthew; Tombline, Gregory; May, Alfred; Morello, Timothy D; Hubbard, Basil P; Bredbenner, Katie; Park, Rosa; Sinclair, David A; Bohr, Vilhelm A; Gorbunova, Vera; Seluanov, Andrei

    2016-09-01

    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. PMID:27568560

  10. The NarE protein of Neisseria gonorrhoeae catalyzes ADP-ribosylation of several ADP-ribose acceptors despite an N-terminal deletion.

    Science.gov (United States)

    Rodas, Paula I; Álamos-Musre, A Said; Álvarez, Francisca P; Escobar, Alejandro; Tapia, Cecilia V; Osorio, Eduardo; Otero, Carolina; Calderón, Iván L; Fuentes, Juan A; Gil, Fernando; Paredes-Sabja, Daniel; Christodoulides, Myron

    2016-09-01

    The ADP-ribosylating enzymes are encoded in many pathogenic bacteria in order to affect essential functions of the host. In this study, we show that Neisseria gonorrhoeae possess a locus that corresponds to the ADP-ribosyltransferase NarE, a previously characterized enzyme in N. meningitidis The 291 bp coding sequence of gonococcal narE shares 100% identity with part of the coding sequence of the meningococcal narE gene due to a frameshift previously described, thus leading to a 49-amino-acid deletion at the N-terminus of gonococcal NarE protein. However, we found a promoter region and a GTG start codon, which allowed expression of the protein as demonstrated by RT-PCR and western blot analyses. Using a gonococcal NarE-6xHis fusion protein, we demonstrated that the gonococcal enzyme underwent auto-ADP-ribosylation but to a lower extent than meningococcal NarE. We also observed that gonoccocal NarE exhibited ADP-ribosyltransferase activity using agmatine and cell-free host proteins as ADP-ribose acceptors, but its activity was inhibited by human β-defensins. Taken together, our results showed that NarE of Neisseria gonorrhoeae is a functional enzyme that possesses key features of bacterial ADP-ribosylating enzymes. PMID:27465490

  11. Biodistribution of 3,4-dihydro-5-[11c]methoxy-1(2h)-isoquinolinone, a potential PET tracer for poly(adp-ribose) synthetase

    International Nuclear Information System (INIS)

    Poly(adenosine diphosphate-ribose) synthetase (PARS) is a nuclear enzyme that is activated by deoxyribonucleic acid (DNA) strand breaks and participates in DNA repair. Excessive PARS activation, however, leads to cell death due to depletion of adenosine triphosphate (ATP). To evaluate whether it is possible to detect excessive activation of PARS with positron emission tomography (PET), we examined the pharmacokinetics of 3,4-dihydro-5-[11C]methoxy-1(2H)-isoquinolinone ([11C]MIQO), a potent poly(ADP-ribose) synthetase inhibitor, in the brain of rats and monkeys. Although the uptake of [11C]MIQO in the brain of normal rats was low, [11C]MIQO was rapidly incorporated into and then quickly washed out from the brain. The uptake of the radiotracer in the brain of normal monkeys was also low; however, [11C]MIQO gave a distribution image that differed from that of cerebral blood flow obtained by [15O]water-PET. No localization of [11C]MIQO in the brain of normal monkeys was observed. Low accumulation of some radioactivity was also observed in muscles surrounding the brain of monkeys, but did not seem to interfere with measurement of [11C]MIQO uptake in the brain with PET. Thus, detection of [11C]MIQO uptake with PET may be useful for detecting PARS activity in ischemic injury

  12. TIMELESS Forms a Complex with PARP1 Distinct from Its Complex with TIPIN and Plays a Role in the DNA Damage Response

    OpenAIRE

    Lauren M. Young; Antonio Marzio; Pablo Perez-Duran; Dylan A. Reid; Daniel N. Meredith; Domenico Roberti; Ayelet Star; Eli Rothenberg; Beatrix Ueberheide; Michele Pagano

    2015-01-01

    SUMMARY PARP1 is the main sensor of single- and double-strand breaks in DNA and, in building chains of poly(ADP-ribose), promotes the recruitment of many downstream signaling and effector proteins involved in the DNA damage response (DDR). We show a robust physical interaction between PARP1 and the replication fork protein TIMELESS, distinct from the known TIMELESS-TIPIN complex, which activates the intra-S phase checkpoint. TIMELESS recruitment to laser-induced sites of DNA damage is depende...

  13. NIH study uncovers new mechanism of action for class of chemotherapy drugs

    Science.gov (United States)

    NIH researchers have discovered a significant new mechanism of action for a class of chemotherapy drugs known as poly (ADP-ribose) polymerase inhibitors, or PARP inhibitors. They have also identified differences in the toxic capabilities of three drugs in

  14. Effect of DENND2D on the cisplatinum cytotoxicity in H1299 cells by regulating PARP1%DENND2D通过调控PARP1对非小细胞肺癌细胞系H1299中顺铂细胞毒性的影响

    Institute of Scientific and Technical Information of China (English)

    凌兵; 冯林; 程书钧

    2013-01-01

    OBJECTIVE: To investigate the effect of DENN/MADD domain containing 2D (DENND2D) gene on the cytotoxity of cisplatinum in non-small cell lung cancer cell line H1299 and explore the mechanism preliminarily. METHODS:DENND2D gene was transient & stably transfected into H1299 cells. CCK-8 assay was used to test the cell counts of DENND2D transfected H1299 cells treated with various concentrations of cisplatinum and IC results were 50 attained. PARP1 protein expression was evaluated by western blot. DENND2D over-expressed H1299 cells were treated with cisplatinum for 0,1,2,4 and 8 h. The PAR expressions were measured by Western blot. RESULTS:IC was 50 decreased in DENND2D over-expressed group compared to vector group. PARP1 and PAR were down-regulated in DENND2D over-expressed H1299 cells. With the prolonged platinum treatment time,the expression of PAR was downregulated in DENND2D group whereas it was opposite in the vector group. CONCLUSION:DENND2D may enhanced the cytotoxicity of cisplatinum in H1299 cells by down regulating PARP1.%目的:检测肺癌细胞系H1299细胞中DENN/MADD domain containing 2D (DENND2D)基因过表达对顺铂细胞毒性的影响,并初步探讨其机制.方法:应用瞬时和稳定转染两种方法使H1299细胞外源过表达DENND2D基因,以空载体组作为对照组,应用CCK-8比色法检测不同浓度顺铂作用下H1299细胞的存活情况,据此计算出IC 值.利用Western blot方法检测外源过表达50DENND2D的H1299细胞多聚ADP核糖聚合酶 [poly (ADP-ribose) polymerase-1,PARP1]的表达情况.利用顺铂处理外源过表达DENND2D的H1299细胞,并检测不同处理时间点 (0、1、2、4和8 h)H1299细胞多聚ADP核糖[poly (ADP-ribose),PAR]的表达情况.结果:顺铂对外源过表达DENND2D基因的H1299细胞毒性明显高于空载体组 (IC 值降低,P<0.05).外源过表达DENND2D的50H1299细胞PARP1蛋白和PAR蛋白的表达均比空载体对照组低,且空载体对照组PAR的表达

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Expressions of Poly(ADP-ribose)Glycohydrolase(PARG)and Membrane Type 1 Matrix Metalloproteinase(MT1-MMP)in Colorectal Carcinoma

    Institute of Scientific and Technical Information of China (English)

    Xian Li; Guang-jie Duan; Ya-lan Wang; N.Jasmine Fauzee; Qiao-zhuan Li

    2010-01-01

    Objective:To investigate the significance of Poly(ADP-ribose)glycolhydrolase(PARG)and membrane type 1matrix metalloproteinase(MT1-MMP)expressions in human colorectal carcinoma.Methods:Immunohistochemical staining for PARG and MT1-MMP was carried out on colorectal adenoma-carcinoma tissue microarrays containing normal colorectal mucosae,adenoma,adenoma with malignant transformation and adenocarcinoma(total 130 specimens).The expressions of PARG and MT1-MMP in the GLTN[Gallotannin]-treated and GLTN-untreated lovo cells were detected by Western Blot.Results:PARG expression in adenocarcinoma(83.1%)and adenoma with malignant transformation(66.7%)was significantly higher than that in normal colorectal mucosa(10%)and adenoma(10.5%).Expression of MT1-MMp in normal colorectal mucosa and adenoma was negative,while the expression in adenocarcinoma(80.3%)and adenoma with malignant transformation(72.2%)was high.The expressions of PARG and MT1-MMP in adenocarcinoma with metastasis and in late tumor stages were significantly higher than those in adenocarcinoma with no metastasis and in early tumor stages.Thus,PARG expression shows a positive correlation with the expression of MT1-MMP.The expressions of PARG and MT1-MMP in GLTN-treated lovo cells were weaker than that in GLTN-untreated lovo cells.Conclusion:The expression of PARG was probably related to the development of colorectal carcinoma.PARG may play an important role for the regulation of MT1-MMP expression in colorectal carcinoma.

  17. Association between the PARP1 Val762Ala polymorphism and cancer risk: evidence from 43 studies.

    Directory of Open Access Journals (Sweden)

    Rui-Xi Hua

    Full Text Available BACKGROUND: Poly (ADP-ribose polymerase-1 (PARP-1 plays critical roles in the detection and repair of damaged DNA, as well as cell proliferation and death. Numerous studies have examined the associations between PARP1 Val762Ala (rs1136410 T>C polymorphism and cancer susceptibility; nevertheless, the findings from different research groups remain controversial. METHODS: We searched literatures from MEDLINE, EMBASE and CBM pertaining to such associations, and then calculated pooled odds ratio (OR and 95% confidence interval (CI by using random-effects model. The false-positive report probability (FPRP analysis was used to confirm the validity of significant findings. Moreover, potential effects of rs1136410 variants on PARP1 mRNA expression were analyzed for three ethnicities by combining data from HapMap (genotype and SNPexp (mRNA expression. RESULTS: The final meta-analysis incorporated 43 studies, consisting of 17,351 cases and 22,401 controls. Overall, our results did not suggest significant associations between Ala variant (Ala/Ala or Ala/Val genotype and cancer risk. However, further stratification analysis showed significantly increased risk for gastric cancer (Ala/Ala vs. Val/Val: OR = 1.56, 95% CI = 1.01-2.42, Ala/Val vs. Val/Val: OR = 1.34, 95% CI = 1.14-1.58, dominant model: OR = 1.41, 95% CI = 1.21-1.65 and Ala vs. Val: OR = 1.29, 95% CI = 1.07-1.55. On the contrary, decreased risk for brain tumor (Ala/Val vs. Val/Val: OR = 0.77, 95% CI = 0.68-0.87, dominant model: OR = 0.77, 95% CI = 0.68-0.87 and Ala vs. Val: OR = 0.82, 95% CI = 0.74-0.91. Additionally, we found that the Ala carriers had a significantly increased risk in all models for Asians. Our mRNA expression data provided further biological evidence to consolidate this finding. CONCLUSIONS: Despite some limitations, this meta-analysis found evidence for an association between the PAPR1 Val762Ala and cancer susceptibility within gastric cancer, brain tumor and Asian subgroups.

  18. PARP-1 Val762Ala polymorphism and risk of cancer: a meta-analysis based on 39 case-control studies.

    Directory of Open Access Journals (Sweden)

    Qin Qin

    Full Text Available BACKGROUND: Poly(ADP-ribose polymerase-1 (PARP-1 is a nuclear chromatin-associated enzyme involved in several important cellular processes, particularly in the DNA repair system. PARP-1 rs1136410: C>T is among the most studied polymorphisms and likely involved in human carcinogenesis. However, results from previous studies are inconclusive. Thus, a meta-analysis was conducted to derive a more precise estimation of the effects of this enzyme. METHODOLOGY AND PRINCIPAL FINDINGS: A comprehensive search was conducted in the PubMed and EMBASE databases until December 9, 2013. A total of 39 studies with 16,783 cancer cases and 23,063 control subjects were included in the meta-analysis on the basis of the inclusion and exclusion criteria. No significant association between the PARP-1 Val762Ala polymorphism and cancer risk was found when all of the studies were pooled into the analysis (VA + AA vs. VV: OR = 1.03, 95% CI = 0.95-1.11. The subgroup analysis of cancer types revealed that the -762Ala allele was associated with increased risk of gastric, cervical, and lung cancers and a decreased risk of glioma. In addition, a significantly increased risk of cancer associated with the polymorphism was observed in Asian descendents (VA + AA vs. VV: OR = 1.17, 95% CI = 1.09-1.25; AA vs. VV: OR = 1.28, 95% CI = 1.08-1.51; VA vs. VV: OR = 1.12, 95% CI = 1.04-1.20; AA vs. VA + VV: OR = 1.09, 95% CI = 1.03-1.39. These results also indicated that a joint effect between PARP-1 Val762Ala and XRCC1 Arg399Gln could be involved in the risk of cancer development (OR = 3.53, 95% CI = 1.30-9.59. CONCLUSION: The present meta-analysis provides evidence that the PARP-1 Val762Ala may be involved in cancer development at least in some ethnic groups (Asian or some specific cancer types (gastric, cervical, and lung cancers, and glioma.

  19. Modulation of farnesoid X receptor results in post-translational modification of poly (ADP-ribose) polymerase 1 in the liver

    OpenAIRE

    Zhu, Yan; Li, Guodong; Dong, Yafeng; Zhou, Helen H.; Kong, Bo; Aleksunes, Lauren M.; Richardson, Jason R.; Li, Fei; Guo, Grace L.

    2012-01-01

    The farnesoid X receptor (FXR) is a bile acid-activated transcription factor belonging to the nuclear receptor superfamily. FXR deficiency in mice results in cholestasis, metabolic disorders, and tumorigenesis in liver and intestine. FXR is known to contribute to pathogenesis by regulating gene transcription; however, changes in the post-transcriptional modification of proteins associated with FXR modulation have not been determined. In the current study, proteomic analysis of the livers of w...

  20. Absence of Poly(ADP-Ribose) Polymerase 1 Delays the Onset of Salmonella enterica Serovar Typhimurium-Induced Gut Inflammation▿ †

    OpenAIRE

    Altmeyer, Matthias; Barthel, Manja; Eberhard, Matthias; Rehrauer, Hubert; Hardt, Wolf-Dietrich; Hottiger, Michael O

    2010-01-01

    The immune system comprises an innate and an adaptive immune response to combat pathogenic agents. The human enteropathogen Salmonella enterica serovar Typhimurium invades the intestinal mucosa and triggers an early innate proinflammatory host gene response, which results in diarrheal disease. Several host factors, including transcription factors and transcription coregulators, are involved in the acute early response to Salmonella infection. We found in a mouse model of enterocolitis induced...

  1. Methotrexate induces poly(ADP-ribose) polymerase-dependent, caspase 3-independent apoptosis in subsets of proliferating CD4+ T cells

    DEFF Research Database (Denmark)

    Nielsen, C H; Albertsen, L; Bendtzen, K;

    2007-01-01

    The mechanism of action of methotrexate (MTX) in autoimmune diseases (AID) is unclear. A pro-apoptotic effect has been demonstrated in mitogen-stimulated peripheral blood mononuclear cells (PBMC), but studies employing conventional antigens have disputed a pro-apoptotic effect. CD4+ T helper (Th...

  2. Poly(ADP-ribose) polymerase-1-induced NAD+ depletion promotes nuclear factor-κB transcriptional activity by preventing p65 de-acetylation

    OpenAIRE

    Kauppinen, Tiina M; Gan, Li; Swanson, Raymond A.

    2013-01-01

    NF-κB is a transcription factor that integrates pro-inflammatory and pro-survival responses in diverse cell types. The activity of NF-κB is regulated in part by acetylation of its p65 subunit at lysine 310,which is required for transcription complex formation. De-acetylation at this site is performed by sirtuin 1(SIRT1) and possibly other sirtuins in an NAD+ dependent manner, such that SIRT1 inhibition promotes NF-κB transcriptional activity. It is unknown, however, whether changes in NAD+ le...

  3. Methotrexate induces poly(ADP-ribose) polymerase-dependent, caspase 3-independent apoptosis in subsets of proliferating CD4+ T cells

    DEFF Research Database (Denmark)

    Nielsen, C H; Albertsen, L; Bendtzen, K;

    2007-01-01

    ) cells play a significant role in most AID. We therefore examined directly, by flow cytometry, the uptake of MTX by the T helper (Th) cells stimulated for 6 days with Candida albicans (CA) or tetanus toxoid (TT), and its consequences with respect to induction of apoptosis. While none of the resting Th...

  4. Cyclic ADP-Ribose and Heat Regulate Oxytocin Release via CD38 and TRPM2 in the Hypothalamus during Social or Psychological Stress in Mice

    Science.gov (United States)

    Zhong, Jing; Amina, Sarwat; Liang, Mingkun; Akther, Shirin; Yuhi, Teruko; Nishimura, Tomoko; Tsuji, Chiharu; Tsuji, Takahiro; Liu, Hong-Xiang; Hashii, Minako; Furuhara, Kazumi; Yokoyama, Shigeru; Yamamoto, Yasuhiko; Okamoto, Hiroshi; Zhao, Yong Juan; Lee, Hon Cheung; Tominaga, Makoto; Lopatina, Olga; Higashida, Haruhiro

    2016-01-01

    Hypothalamic oxytocin (OT) is released into the brain by cyclic ADP-ribose (cADPR) with or without depolarizing stimulation. Previously, we showed that the intracellular free calcium concentration ([Ca2+]i) that seems to trigger OT release can be elevated by β-NAD+, cADPR, and ADP in mouse oxytocinergic neurons. As these β-NAD+ metabolites activate warm-sensitive TRPM2 cation channels, when the incubation temperature is increased, the [Ca2+]i in hypothalamic neurons is elevated. However, it has not been determined whether OT release is facilitated by heat in vitro or hyperthermia in vivo in combination with cADPR. Furthermore, it has not been examined whether CD38 and TRPM2 exert their functions on OT release during stress or stress-induced hyperthermia in relation to the anxiolytic roles and social behaviors of OT under stress conditions. Here, we report that OT release from the isolated hypothalami of male mice in culture was enhanced by extracellular application of cADPR or increasing the incubation temperature from 35°C to 38.5°C, and simultaneous stimulation showed a greater effect. This release was inhibited by a cADPR-dependent ryanodine receptor inhibitor and a nonspecific TRPM2 inhibitor. The facilitated release by heat and cADPR was suppressed in the hypothalamus isolated from CD38 knockout mice and CD38- or TRPM2-knockdown mice. In the course of these experiments, we noted that OT release differed markedly between individual mice under stress with group housing. That is, when male mice received cage-switch stress and eliminated due to their social subclass, significantly higher levels of OT release were found in subordinates compared with ordinates. In mice exposed to anxiety stress in an open field, the cerebrospinal fluid (CSF) OT level increased transiently at 5 min after exposure, and the rectal temperature also increased from 36.6°C to 37.8°C. OT levels in the CSF of mice with lipopolysaccharide-induced fever (+0.8°C) were higher than those

  5. AcEST: BP918533 [AcEST

    Lifescience Database Archive (English)

    Full Text Available lymerase (Fragment) OS=Xenopus laevis GN=parp1 PE=2 SV=1 Length = 998 Score = 97.4 bits (241), Expect = 2e-2...19 tr|Q2NLA7|Q2NLA7_XENLA PARP protein OS=Xenopus laevis GN=parp1 P... 97 3e-19 tr|B8AIZ7|B8AIZ7_ORYSI Putative unchar...|PARP1_RAT Poly [ADP-ribose] polymerase 1 OS=Rattus norvegicus GN=Parp1 PE=2 SV=4...oly [ADP-ribose] polymerase 1 OS=Mus musculus GN=Parp1 PE=1 SV=3 Length = 1013 Sc...AARVFS 350 >tr|Q921K2|Q921K2_MOUSE Poly (ADP-ribose) polymerase family, member 1 OS=Mus musculus GN=Parp1

  6. 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.

  7. AcEST: BP915227 [AcEST

    Lifescience Database Archive (English)

    Full Text Available RKWGRVGNEK 558 >sp|P31669|PARP1_XENLA Poly [ADP-ribose] polymerase (Fragment) OS=Xenopus laevis GN=parp1 PE=...+G Sbjct: 183 IQALESDAG-GNFMVYSRWGRVG 204 >sp|O88554|PARP2_MOUSE Poly [ADP-ribose] polymerase 2 OS=Mus musculus GN=Parp...15227 CL802Contig1 Show BP915227 Clone id YMU001_000069_A06 Library YMU01 Length 513 Definition Adiantum cap...CCTTAATGGACTCATCCTCTTTTGATTCCTCGTCAA GATCTTCTTTTTCCTCTCGATTATCACCTGATT ■■Homology search results ■■ - Swiss-...a new generation of protein database search programs, Nucleic Acids Res. 25:3389-

  8. 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.

  9. PARP inhibitor 3-aminobenzamide does not increase the yields of chromosomal aberrant cells induced by boron neutron capture reaction in V79 Chinese hamster cells

    International Nuclear Information System (INIS)

    Full text: Mechanistic knowledge on DNA and cell damage induced by alpha-particles remains limited. It is well known that high-LET radiation induces both DNA single (ssb) and double strand breaks (dsb), being the latter frequently associated with cell death. The repair of these DNA lesions and specially dsb are thus fundamental for the understanding of high-LET radiation effects. Poly (ADP-ribose) polymerase is a nuclear enzyme, which detects and signals DNA strand breaks (ssb and dsb). The important role of this enzyme in the maintenance of DNA integrity has been extensively studied for genotoxic chemicals and low-LET ionizing radiation. Nevertheless, sparse information concerning the role of PARP in high-LET radiation effects is available. The purpose of this work is to examine whether the PARP inhibitor 3-aminobenzamide (3-AB) enhances the yields of chromosomal aberrations induced by the boron neutron capture (BNC) reaction in V79 Chinese hamster cells. Wild-type V79 cells were pre-incubated for 48 hours with different concentrations (0.48-2.4 mM) of the boron delivery agent 4-borono-L-phenylalanine (BPA) and then irradiated for different periods of time with thermal neutrons. In the 3-AB treated cultures, four hours before the irradiation the cells were incubated with different concentrations of this inhibitor (1.5-10 mM) which remained in culture until colchicine was added. The chromosomal aberrations assay was performed according to standard protocol. A clear dose-response in the frequencies of chromosomal aberrant cells excluding gaps (%CAEG) induced by the BNC reaction was observed for both BPA concentration and thermal neutron fluence. There was no evidence of an increase in the % CAEG induced after incubation with 3-AB. Some cytoxicity was observed (mitotic index) after 3-AB incubation in BPA irradiated cells. In conclusion, the clastogenic potential of the alpha-particles generated through the BNC reaction was not affected by using a classic PARP

  10. 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.

  11. Poly(ADP-ribosyl)ation links the chromatin remodeler SMARCA5/SNF2H to RNF168-dependent DNA damage signaling

    DEFF Research Database (Denmark)

    Smeenk, G.; Wiegant, W.W.; Luijsterburg, M.S.; Costelloe, T.; Romeijn, R.J.; Pastink, A.; van Attikum, H.; Marteijn, J.A.; Vermeulen, W.; Sroczynski, Nicholas; Mailand, N.

    2013-01-01

    unexplored. Here, we show that SMARCA5/SNF2H, the catalytic subunit of ISWI chromatin remodeling complexes, is recruited to DSBs in a poly(ADP-ribose) polymerase 1 (PARP1)-dependent manner. Remarkably, PARP activity, although dispensable for the efficient spreading of νH2AX into damaged chromatin...

  12. 和厚朴酚通过抑制脑MPTP开放和调节PARP-1活性保护全脑缺血的作用研究%Honokiol protects brain against global brain ischemia in mice through inhibiting MPTP opening and PARP-1 activity

    Institute of Scientific and Technical Information of China (English)

    杨爽; 刘晓岩; 胡振宇; 陈世忠; 王银叶

    2012-01-01

    目的 研究和厚朴酚微乳剂对全脑缺血的影响,探讨其可能的作用机制.方法 用断头法制备小鼠急性全脑缺血模型;用分光光度法观察脑线粒体通透性转换孔(MPTP)开放程度;用荧光法测定聚腺苷二磷酸核糖聚合酶-1(PARP-1)活性;用MTT法侧细胞活力.结果 和厚朴酚(7~70 μg*kg-1)单次静注可剂量依赖地增加小鼠断头后喘息次数、降低小鼠脑匀浆液中乳酸的含量,升高脑匀浆液中ATP的含量.和厚朴酚(2.5 μmol*L-1~10 μmol*L-1)可浓度依赖地降低脑组织MPTP的开放,它可浓度依赖地抑制聚腺苷二磷酸核糖聚合酶(PARP-1)活性,其IC50=76.82 μmol*L-1,和厚朴酚可明显提高缺氧损伤的PC12细胞存活率.结论 和厚朴酚对全脑缺血有保护作用,该作用与其可能减轻缺血状态、抑制能量耗竭和乳酸堆积有关,可能与抑制神经细胞MPTP开放、抑制PARP-1的活性、从而保护神经细胞有关.这些结果为其治疗全脑缺血提供了实验依据.%Aim To investigate the influence of hono-kiol microemulsion on global ischemia in mice, and explore its potential action mechanism. Methods Global ischemia model in mice was prepared by decapitation, the opening of mitochondria permeability transition pore ( MPTP ) was detected by spectrophotometry, and the activity of poly-ADP ribose polymerase-1 ( PARP-1 ) was determined by fluorometric method. Results Honokiol ( 7 ~ 70 μg · kg -1 bolus iv ) significantly increased the breath times of mice, and decreased lactic acid contents and augmented ATP level in brain ho-mogenate in this model. Honokiol ( 2. 5 μmol · L -1 ~ 10 μmol ·L-1 ) concentration dependently reduced ΔA520 of mitochondria suspension and inhibited PARP-1 activity. In addition, honokiol enhanced the viability of PC 12 cells injured by anoxia. Conclusions This study first discovers the protection of honokiol on global ischemia. The mechanism of its action may be correlated with its

  13. Increased poly(ADP-ribosyl)ation in skeletal muscle tissue of pediatric patients with severe burn injury: prevention by propranolol treatment

    OpenAIRE

    Oláh, Gábor; Finnerty, Celeste; Sbrana, Elena; Elijah, Itoro; Gerö, Domokos; Herndon, David; Szabó, Csaba

    2011-01-01

    Activation of the nuclear enzyme poly (ADP-ribose) polymerase (PARP) has been shown to promote cellular energetic collapse and cellular necrosis in various forms of critical illness. Most of the evidence implicating the PARP pathway in disease processes is derived from preclinical studies. With respect to PARP and burns, studies in rodent and large animal models of burn injury have demonstrated the activation of PARP in various tissues and the beneficial effect of its pharmacological inhibiti...

  14. Essential role of poly(ADP-ribosyl)ation in cocaine action

    OpenAIRE

    Scobie, Kimberly N.; Damez-Werno, Diane; Sun, HaoSheng; Shao, NingYi; Gancarz, Amy; Panganiban, Clarisse H.; Dias, Caroline; Koo, Jawook; Caiafa, Paola; Kaufman, Lewis; Neve, Rachael L.; Dietz, David M.; Shen, Li; Nestler, Eric J.

    2014-01-01

    We demonstrate that chronic cocaine, including cocaine self-administration, induces poly(ADP-ribose) polymerase-1 (PARP-1) in the nucleus accumbens (NAc). Using a combination of viral-mediated gene transfer and pharmacological tools, we show that upregulation of PARP-1 in NAc dramatically enhances behavioral responses to cocaine, whereas downregulation of PARP-1 has the opposite effect. We used chromatin immunoprecipitation sequencing to map genome-wide binding of PARP-1 in NAc. The data demo...

  15. How to kill tumor cells with inhibitors of poly(ADP-ribosyl)ation

    OpenAIRE

    Mangerich, Aswin; Bürkle, Alexander

    2011-01-01

    Poly(ADP-ribosyl)ation is a post-translational modification catalyzed by the enzyme family of poly(ADP-ribose) polymerases (PARPs). PARPs exhibit pleiotropic cellular functions ranging from maintenance of genomic stability and chromatin remodeling to regulation of cell death, thereby rendering PARP homologues promising targets in cancer therapy. Depending on the molecular status of a cancer cell, low-molecular weight PARP inhibitors can (i) either be used as monotherapeutic agents following t...

  16. TOPBP1 regulates RAD51 phosphorylation and chromatin loading and determines PARP inhibitor sensitivity

    DEFF Research Database (Denmark)

    Moudry, Pavel; Watanabe, Kenji; Wolanin, Kamila M; Bartkova, Jirina; Wassing, Isabel E; Watanabe, Sugiko; Strauss, Robert; Troelsgaard Pedersen, Rune; Oestergaard, Vibe H; Lisby, Michael; Andújar-Sánchez, Miguel; Maya-Mendoza, Apolinar; Esashi, Fumiko; Lukas, Jiri; Bartek, Jiri

    2016-01-01

    Topoisomerase IIβ-binding protein 1 (TOPBP1) participates in DNA replication and DNA damage response; however, its role in DNA repair and relevance for human cancer remain unclear. Here, through an unbiased small interfering RNA screen, we identified and validated TOPBP1 as a novel determinant...... whose loss sensitized human cells to olaparib, an inhibitor of poly(ADP-ribose) polymerase. We show that TOPBP1 acts in homologous recombination (HR) repair, impacts olaparib response, and exhibits aberrant patterns in subsets of human ovarian carcinomas. TOPBP1 depletion abrogated RAD51 loading to...... serine 14, a modification required for RAD51 recruitment to chromatin. Overall, our results provide mechanistic insights into TOPBP1's role in HR, with potential clinical implications for cancer treatment....

  17. AcEST: BP915741 [AcEST

    Lifescience Database Archive (English)

    Full Text Available cDNA FLJ58629, highly similar to Poly (AD... 92 3e-28 tr|Q2NLA7|Q2NLA7_XENLA PARP protein OS=Xenopus laevis GN=parp1...ADP-ribose] polymerase 1 OS=Rattus norvegicus GN=Parp1 PE=2 SV=4 Length = 1014 Score = 95.1 bits (235), Expe... Poly [ADP-ribose] polymerase 1 OS=Mus musculus GN=Parp1 PE=1 SV=3 Length = 1013 Score = 95.1 bits (235), Ex...ribose) polymerase family, member 1 OS=Mus musculus GN=Parp1 PE=2 SV=1 Length = 1014 Score = 95.1 bits (235)...RGGSDDSSKDPIDVNYEKLKTDIKVVDRDSEE 810 >tr|Q3UJ03|Q3UJ03_MOUSE Putative uncharacterized protein OS=Mus musculus GN=Parp1

  18. PARP-1 inhibitor, DPQ, attenuates LPS-induced acute lung injury through inhibiting NF-κB-mediated inflammatory response.

    Directory of Open Access Journals (Sweden)

    Gang Wang

    Full Text Available Acute lung injury (ALI is characterized by overwhelming lung inflammation and anti-inflammation treatment is proposed to be a therapeutic strategy for ALI. Poly (ADP-ribose polymerase-1 has been demonstrated to be involved in tissue inflammation and one of its inhibitors, 3, 4-Dihydro-5[4-(1-piperindinylbutoxy]-1(2H-isoquinoline (DPQ, exerts anti-inflammatory effect. However, it is still unclear whether the DPQ possesses the protective effect on ALI and what mechanisms are involved. In this study, we tested the effect of DPQ on the lung inflammation induced by lipopolysaccharide (LPS challenge in mice. We found that 6 h-LPS challenge induced significant lung inflammation and vascular leakage in mice. Treatment with DPQ at the dose of 10 μg/kg markedly reduced the neutrophil infiltration, myeloperoxidase activity and up-regulation of pro-inflammatory mediators and cytokines. LPS-elevated vascular permeability was decreased by DPQ treatment, accompanied by the inhibition of apoptotic cell death in mice lungs. In addition, we isolated mice peritoneal macrophages and showed pretreatment with DPQ at 10 μM inhibited the production of cytokines in the macrophages following LPS stimulation. DPQ treatment also inhibited the phosphorylation and degradation of IκB-α, subsequently blocked the activation of nuclear factor (NF-κB induced by LPS in vivo and in vitro. Taken together, our results show that DPQ treatment inhibits NF-κB signaling in macrophages and protects mice against ALI induced by LPS, suggesting inhibition of Poly (ADP-ribose polymerase-1 may be a potential and effective approach to resolve inflammation for the treatment of ALI.

  19. Inhibition of matrix metalloproteinase-2 by PARP inhibitors

    OpenAIRE

    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 dete...

  20. ARTD1/PARP1 negatively regulates glycolysis by inhibiting hexokinase 1 independent of NAD+ depletion

    Science.gov (United States)

    Fouquerel, Elise; Goellner, Eva M.; Yu, Zhongxun; Gagné, Jean-Philippe; de Moura, Michelle Barbi; Feinstein, Tim; Wheeler, David; Redpath, Philip; Li, Jianfeng; Romero, Guillermo; Migaud, Marie; Van Houten, Bennett; Poirier, Guy G.; Sobol, Robert W.

    2014-01-01

    Summary ARTD1 (PARP1) is a key enzyme involved in DNA repair by synthesizing poly(ADP-ribose) (PAR) in response to strand breaks and 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 directly 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 new insight on the importance of nucleus to mitochondria communication via ARTD1 activation. PMID:25220464

  1. 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.

  2. Age-Associated Changes In Oxidative Stress and NAD+ Metabolism In Human Tissue

    OpenAIRE

    Hassina Massudi; Ross Grant; Nady Braidy; Jade Guest; Bruce Farnsworth; Guillemin, Gilles J

    2012-01-01

    Nicotinamide adenine dinucleotide (NAD(+)) is an essential electron transporter in mitochondrial respiration and oxidative phosphorylation. In genomic DNA, NAD(+) also represents the sole substrate for the nuclear repair enzyme, poly(ADP-ribose) polymerase (PARP) and the sirtuin family of NAD-dependent histone deacetylases. Age associated increases in oxidative nuclear damage have been associated with PARP-mediated NAD(+) depletion and loss of SIRT1 activity in rodents. In this study, we furt...

  3. Age-Associated Changes In Oxidative Stress and NAD+ Metabolism In Human Tissue

    OpenAIRE

    Massudi, Hassina; Grant, Ross; Braidy, Nady; Guest, Jade; Farnsworth, Bruce; Guillemin, Gilles J.

    2012-01-01

    Nicotinamide adenine dinucleotide (NAD+) is an essential electron transporter in mitochondrial respiration and oxidative phosphorylation. In genomic DNA, NAD+ also represents the sole substrate for the nuclear repair enzyme, poly(ADP-ribose) polymerase (PARP) and the sirtuin family of NAD-dependent histone deacetylases. Age associated increases in oxidative nuclear damage have been associated with PARP-mediated NAD+ depletion and loss of SIRT1 activity in rodents. In this study, we further in...

  4. DNA polymerase activity and radiation-induced unscheduled synthesis of DNA at the nuclear matrix

    International Nuclear Information System (INIS)

    It is shown that both DNA polymerase α and β are involved in DNA synthesis at the nuclear matrix. DNA polymerase β is more firmly attached to the nuclear matrix of normal than of regenerating liver cells. In the nuclear matrix of UV- and gamma-irradiated cells of Zajdela hepatoma a higher level of hydroxyurea-resistant DNA synthesis has been observed in the initial 1.5-5 min of postradiation incubation if compared to that of total nuclear DNA. However 1-β-D-arabinofuranosylcytosine-resistant radiation-induced synthesis of DNA is similar in both the nuclear matrix and the whole nuclei of these cells. Poly(ADP-ribose)synthetase activity is shown to be associated with the nuclear matrix. Inhibition of this activity results in increase of the hydroxyurea-resistant synthesis of DNA at nuclear matrix. (author)

  5. 筋脉通含药血清降低高糖培养大鼠雪旺细胞活性氧水平及PARP-1蛋白表达%Effects of Chinese herbal medicine Jinmaitong-containing serum on the ROS level and expression of PARP-1 of rat Schwann cells cultured in high-glucose medium

    Institute of Scientific and Technical Information of China (English)

    石玥; 梁晓春; 张宏; 王普艳; 赵丽

    2012-01-01

    Objective To investigate the effects of medicated serum prepared by administration of Jinmaitong (JMT) , a compound Chinese herbal medicine, on oxidative damage and poly ADP-ribose polymerase-1 (PARP-1) of Schwann cells cultured in high-glucose medium. Methods SD rats were divided into normal control group ( distilled water) ,JMT group and vitamin C group to prepare medicated serum. Bilateral sciatic nerves of new born SD rats were used to separate Schwann cells. Schwann cells cultured in high-glucose medium were divided into high glucose group (50 mmol/L glucose medium,JMT group( JMT-medica-ted serum) and vitamin C( VC) group (VC-medicated serum). Schwann cells cultured in DMEM were used as the normal control. After48 h culturing, the level of ROS was measured by confocal laser scanning microscope with 2',7'-dichlorofluorescein( DCF) as a molecular probe and the expression of PARP-1 protein was detected by Western blot. Results 1) Compared with high glucose group, the fluorescence intensities of ROS-DEC in Schwann cells cultured in JMT and VC groups were weaker significantly (P <0. 01). There were no significant differences between these two treated groups. 2) Compared with high glucose group,the expression of PARP-1 (89 ku) in Schwann cells cultrued in JMT group decreased significantly (P <0. 01). The expression of JMT group was also much lower than that of VC group (P <0. 01). Conclusions The medicated serum of JMT down-regulates the expression of ROS and PARP-1 of Schwann cells cultured in high glucose medium and reduces the oxidative DNA damage.%目的 研究筋脉通含药血清对体外高糖培养雪旺细胞活性氧(ROS)水平及多聚(ADP-核糖)聚合酶-1(PARP-1)蛋白表达的影响.方法 30只雄性SD大鼠随机分为3组,分别灌胃筋脉通(JMT)、维生素C(VC)或蒸馏水制备含药血清和对照血清.取新出生大鼠的双侧坐骨神经用于制备雪旺细胞,分为高糖组、JMT组(加入筋脉通含药血清)、VC组(加入维生

  6. Parthanatos, a messenger of death

    OpenAIRE

    David, Karen Kate; Andrabi, Shaida Ahmad; Dawson, Ted Murray; Dawson, Valina Lynn

    2009-01-01

    Poly-ADP-ribose polymerase-1 (PARP-1)'s multiple roles in the cell span from maintaining life to inducing death. The processes PARP-1 is involved in include, but are not limited to DNA repair, DNA transcription, mitosis, and cell death. Of PARP-1's different cellular functions, its active role in cell death is of particular interest to designing therapies for diseases. Genetic deletion of PARP-1 revealed that PARP-1 over activation underlies cell death in experimental models of stroke, diabet...

  7. The formation of vault-tubes: a dynamic interaction between vaults and vault PARP.

    Science.gov (United States)

    van Zon, Arend; Mossink, Marieke H; Schoester, Martijn; Houtsmuller, Adriaan B; Scheffer, George L; Scheper, Rik J; Sonneveld, Pieter; Wiemer, Erik A C

    2003-11-01

    Vaults are barrel-shaped cytoplasmic ribonucleoprotein particles that are composed of a major vault protein (MVP), two minor vault proteins [telomerase-associated protein 1 (TEP1), vault poly(ADP-ribose) polymerase (VPARP)] and small untranslated RNA molecules. Not all expressed TEP1 and VPARP in cells is bound to vaults. TEP1 is known to associate with the telomerase complex, whereas VPARP is also present in the nuclear matrix and in cytoplasmic clusters (VPARP-rods). We examined the subcellular localization and the dynamics of the vault complex in a non-small cell lung cancer cell line expressing MVP tagged with green fluorescent protein. Using quantitative fluorescence recovery after photobleaching (FRAP) it was shown that vaults move temperature independently by diffusion. However, incubation at room temperature (21 degrees C) resulted in the formation of distinct tube-like structures in the cytoplasm. Raising the temperature could reverse this process. When the vault-tubes were formed, there were fewer or no VPARP-rods present in the cytoplasm, suggesting an incorporation of the VPARP into the vault-tubes. MVP molecules have to interact with each other via their coiled-coil domain in order to form vault-tubes. Furthermore, the stability of microtubules influenced the efficiency of vault-tube formation at 21 degrees C. The dynamics and structure of the tubes were examined using confocal microscopy. Our data indicate a direct and dynamic relationship between vaults and VPARP, providing further clues to unravel the function of vaults. PMID:13130096

  8. Incorporating PARP Inhibition in Cancer Therapy: Key Questions, Expert Answers

    Directory of Open Access Journals (Sweden)

    Tristin Abair

    2015-11-01

    Full Text Available This engaging symposium focussed on the rationale and current evidence supporting the role for poly(adenosine diphosphate-ribose polymerase (PARP inhibition in patients with cancer. The meeting opened with an overview of DNA repair and the biological basis for targeting this process in oncology, delivered by Prof Calvert. This was followed by a discussion from Prof Pujade-Lauraine that focussed on patient selection for PARP inhibition and the role for these agents in BRCA -mutated and BRCA -like cancers. Next, Prof Colombo presented a clinical scenario of BRCA -associated ovarian cancer and examined optimal treatment options in the first-line setting and for progressive disease. She also highlighted current clinical data and ongoing trials evaluating PARP inhibition in advanced ovarian cancer. Prof Tutt then discussed the potential role for PARP inhibitors in patients with breast cancer, focussing on a clinical scenario of triple-negative disease and emphasising current and investigational treatment options. Lastly, Prof Van Cutsem described emerging data and ongoing clinical studies evaluating PARP inhibition in the treatment of patients with pancreatic and gastric cancers, and how this could impact future clinical practice. The programme also included a PARP quiz, in which participants were polled at the beginning and conclusion of the symposium to examine their knowledge and practice patterns regarding the use of PARP inhibitors in oncology. The key highlights from these presentations and the PARP quiz are summarised herein.

  9. Tankyrase Inhibitors Stimulate the Ability of Tankyrases to Bind Axin and Drive Assembly of β-Catenin Degradation-Competent Axin Puncta

    OpenAIRE

    Martino-Echarri, Estefania; Brocardo, Mariana G.; Mills, Kate M.; Henderson, Beric R.

    2016-01-01

    Activation of the wnt signaling pathway is a major cause of colon cancer development. Tankyrase inhibitors (TNKSi) have recently been developed to block the wnt pathway by increasing axin levels to promote degradation of the wnt-regulator β-catenin. TNKSi bind to the PARP (poly(ADP)ribose polymerase) catalytic region of tankyrases (TNKS), preventing the PARylation of TNKS and axin that normally control axin levels through ubiquitination and degradation. TNKSi treatment of APC-mutant SW480 col...

  10. Pancreatic Cancer in 2014

    Directory of Open Access Journals (Sweden)

    Serafim Kaltsas

    2014-03-01

    Full Text Available 5-FU/LV: 5-fluorouracil and leucovorin; FOLFIRINOX: 5-fluorouracil, leucovorin, irinotecan, and oxaliplatin; FOLFOX: 5-flouorouracil, leucovorin and oxaliplatin; HA: hyaluronic acid; JAK: Janus kinase; MM-398: irinotecan sucrosofate; MPACT: Metastatic Pancreatic Adenocarcinoma Clinical Trial; PARP: poly (ADP-ribose polymerase; PEGPH: pegylated recombinant human hyaluronidase; PSCA: prostate stem cell antigen; SN-38: active metabolite of irinotecan; SPARC: secreted protein acidic and rich in cysteine

  11. Prevention of acute/severe hypoglycemia-induced neuron death by lactate administration

    OpenAIRE

    Won, Seok Joon; Jang, Bong Geom; Yoo, Byung Hoon; Sohn, Min; Lee, Min Woo; Choi, Bo Young; Kim, Jin Hee; Song, Hong Ki; Suh, Sang Won

    2012-01-01

    Hypoglycemia-induced cerebral neuropathy can occur in patients with diabetes who attempt tight control of blood glucose and may lead to cognitive dysfunction. Accumulating evidence from animal models suggests that hypoglycemia-induced neuronal death is not a simple result of glucose deprivation, but is instead the end result of a multifactorial process. In particular, the excessive activation of poly (ADP-ribose) polymerase-1 (PARP-1) consumes cytosolic nicotinamide adenine dinucleotide (NAD+...

  12. Nitrosative stress and pharmacological modulation of heart failure

    OpenAIRE

    Pacher, Pal; Schulz, Richard; Liaudet, Lucas; Szabó, Csaba

    2005-01-01

    Dysregulation of nitric oxide (NO) and increased oxidative and nitrosative stress are implicated in the pathogenesis of heart failure. Peroxynitrite is a reactive oxidant that is produced from the reaction of nitric oxide with superoxide anion and impairs cardiovascular function through multiple mechanisms, including activation of matrix metalloproteinases (MMPs) and nuclear enzyme poly(ADP-ribose) polymerase (PARP). Recent studies suggest that the neutralization of peroxynitrite or pharmacol...

  13. NAD+ and Sirtuins in Aging and Disease

    OpenAIRE

    Imai, Shin-ichiro; Guarente, Leonard

    2014-01-01

    Nicotinamide adenine dinucleotide (NAD+) is a classical coenzyme mediating many redox reactions. NAD+ also plays an important role in the regulation of NAD+-consuming enzymes, including sirtuins, poly-ADP-ribose polymerases (PARPs), and CD38/157 ectoenzymes. NAD+ biosynthesis, particularly mediated by nicotinamide phosphoribosyltransferase (NAMPT), and SIRT1 function together to regulate metabolism and circadian rhythm. NAD+ levels decline during the aging process and may be an Achilles’ heel...

  14. Protective Pleiotropic Effect of Flavonoids on NAD + Levels in Endothelial Cells Exposed to High Glucose

    OpenAIRE

    Boesten, Daniëlle M. P. H. J.; von Ungern-Sternberg, Saskia N. I.; den Hartog, Gertjan J. M.; Aalt Bast

    2015-01-01

    NAD+ is important for oxidative metabolism by serving as an electron transporter. Hyperglycemia decreases NAD+ levels by activation of the polyol pathway and by overactivation of poly(ADP-ribose)-polymerase (PARP). We examined the protective role of three structurally related flavonoids (rutin, quercetin, and flavone) during high glucose conditions in an in vitro model using human umbilical vein endothelial cells (HUVECs). Additionally we assessed the ability of these flavonoids to inhibit al...

  15. Strategies to Potentiate the Cellular Poly(ADP-ribosyl)ation Response to DNA Damage

    OpenAIRE

    Kunzmann, Andrea

    2009-01-01

    Poly(ADP-ribosyl)ation is a posttranslational modification of cellular proteins, which is mainly catalyzed by poly(ADP-ribose) polymerase 1 (PARP1) by using NAD+ as substrate. The catalytic activity of PARP1 is known to be triggered by the binding of PARP1 to broken DNA via its two aminoterminal zinc finger motifs. DNA strand break-induced poly(ADP-ribosyl)ation is linked to DNA repair and maintenance of genomic stability.Up to now, little information exists on the biological consequences of ...

  16. Parthanatos, a messenger of death.

    Science.gov (United States)

    David, Karen Kate; Andrabi, Shaida Ahmad; Dawson, Ted Murray; Dawson, Valina Lynn

    2009-01-01

    Poly-ADP-ribose polymerase-1 (PARP-1)'s roles in the cell span from maintaining life to inducing death. The processes PARP-1 is involved in include DNA repair, DNA transcription, mitosis, and cell death. Of PARP-1's different cellular functions, its role in cell death is of particular interest to designing therapies for diseases. Genetic deletion of PARP-1 revealed that PARP-1 overactivation underlies cell death in models of stroke, diabetes, inflammation and neurodegeneration. Since interfering with PARP-1 mediated cell death will be clinically beneficial, great effort has been invested into understanding mechanisms downstream of PARP-1 overactivation. Recent evidence shows that poly-ADP ribose (PAR) polymer itself can act as a cell death effector downstream of PARP-1. We coined the term parthanatos after Thanatos, the personification of death in Greek mythology, to refer to PAR-mediated cell death. In this review, we will present evidence and questions raised by these recent findings, and summarize the proposed mechanisms by which PARP-1 overactivation kills. It is evident that further understanding of parthanatos opens up new avenues for therapy in ameliorating diseases related to PARP-1 overactivation. PMID:19273119

  17. Synthesis of alkylcarbonate analogs of O-acetyl-ADP-ribose

    Czech Academy of Sciences Publication Activity Database

    Dvořáková, Marcela; Nencka, Radim; Dejmek, Milan; Zborníková, Eva; Březinová, Anna; Přibylová, Marie; Pohl, Radek; Migaud, M. E.; Vaněk, Tomáš

    2013-01-01

    Roč. 11, č. 34 (2013), s. 5702-5713. ISSN 1477-0520 Institutional support: RVO:61389030 ; RVO:61388963 Keywords : DEACETYLASES * FURANOSIDES * METABOLITE Subject RIV: CC - Organic Chemistry Impact factor: 3.487, year: 2013

  18. Inhibition of matrix metalloproteinase-2 by PARP inhibitors

    International Nuclear Information System (INIS)

    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 IC50 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.

  19. Inhibition of matrix metalloproteinase-2 by PARP inhibitors

    Science.gov (United States)

    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 IC50 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. PMID:19619515

  20. 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.

  1. Adrenomedullin in inflammatory process associated with experimental pulmonary fibrosis

    Directory of Open Access Journals (Sweden)

    Bramanti Placido

    2011-04-01

    Full Text Available Abstract Background Adrenomedullin (AM, a 52-amino acid ringed-structure peptide with C-terminal amidation, was originally isolated from human pheochromocytoma. AM are widely distributed in various tissues and acts as a local vasoactive hormone in various conditions. Methods In the present study, we investigated the efficacy of AM on the animal model of bleomycin (BLM-induced lung injury. Mice were subjected to intratracheal administration of BLM and were assigned to receive AM daily by an intraperitoneal injection of 200 ngr/kg. Results and Discussion Myeloperoxidase activity, lung histology, immunohistochemical analyses for cytokines and adhesion molecules expression, inducible nitric oxide synthase (iNOS, nitrotyrosine, and poly (ADP-ribose polymerase (PARP were performed one week after fibrosis induction. Lung histology and transforming growth factor beta (TGF-β were performed 14 and 21 days after treatments. After bleomycin administration, AM-treated mice exhibited a reduced degree of lung damage and inflammation compared with BLM-treated mice, as shown by the reduction of (1 myeloperoxidase activity (MPO, (2 cytokines and adhesion molecules expression, (3 nitric oxide synthase expression, (4 the nitration of tyrosine residues, (5 poly (ADP-ribose (PAR formation, a product of the nuclear enzyme poly (ADP-ribose polymerase (PARP (6 transforming growth factor beta (TGF-β (7and the degree of lung injury. Conclusions Our results indicate that AM administration is able to prevent bleomycin induced lung injury through the down regulation of proinflammatory factors.

  2. Olaparib for the treatment of ovarian cancer.

    Science.gov (United States)

    Bornstein, E; Jimeno, A

    2016-01-01

    Olaparib, an oral poly(ADP-ribose) polymerase (PARP) inhibitor, is the first FDA-approved drug in its class for patients with ovarian cancer, specifically in a subset of patients with BRCA mutations and prior chemotherapy treatments. PARP inhibitors have had other implications in different solid tumor types including breast, gastric and pancreatic malignancies. In light of the recent FDA approval of olaparib for the treatment of ovarian cancer, this article aims to outline the mechanisms and implications of the drug. With a favorable adverse event profile and improved outcomes, including progression-free survival, olaparib has demonstrated augmentation to therapeutic options in the treatment of ovarian cancer. PMID:26937492

  3. Targeting DNA repair with combination veliparib (ABT-888) and temozolomide in patients with metastatic castration-resistant prostate cancer

    OpenAIRE

    Hussain, Maha; Carducci, Michael A.; Slovin, Susan; Cetnar, Jeremy; Qian, Jiang; McKeegan, Evelyn M.; Refici-Buhr, Marion; Chyla, Brenda; Shepherd, Stacie P.; Giranda, Vincent L.; Alumkal, Joshi J.

    2014-01-01

    Androgen receptor-mediated transcription is directly coupled with the induction of DNA damage, and castration-resistant tumor cells exhibit increased activity of poly (ADP-ribose) polymerase (PARP)-1, a DNA repair enzyme. This study assessed the efficacy and safety of low dose oral PARP inhibitor veliparib (ABT-888) and temozolomide (TMZ) in docetaxel-pretreated patients with metastatic castration-resistant prostate cancer (mCRPC) in a single-arm, open-label, pilot study. Patients with mCRPC ...

  4. -- mRNA expression in human breast cancer: a meta-analysis

    OpenAIRE

    Gonçalves, Anthony; Finetti, Pascal; Sabatier, Renaud; Gilabert, Marine; Adelaide, José; Borg, Jean-Paul; Chaffanet, Max; Viens, Patrice; Birnbaum, Daniel; Bertucci, François

    2010-01-01

    Although poly(ADP-ribose) polymerase-1 (PARP1) inhibition is a recent promising therapy in breast cancer, PARP1 expression in this disease is not known. Using DNA microarray and array-based comparative genomic hybridization (arrayCGH), we examined mRNA expression and copy number alterations in 326 invasive breast cancer samples and normal breast (NB) samples. A meta-analysis was performed on a large public retrospective gene expression data set ( = 2,485) to analyze correlation between mRNA e...

  5. Nitric Oxide: Genomic Instability And Synthetic Lethality

    Directory of Open Access Journals (Sweden)

    Vasily A. Yakovlev

    2015-08-01

    Loss or inhibition of Poly(ADP-ribose polymerase 1 (PARP1 activity results in accumulation of DNA single-strand breaks, which are subsequently converted to DSB by the transcription machinery. In BRCA-positive cells, DSB are repaired by HRR, but they cannot be properly repaired in BRCA1-deficient cells, leading to genomic instability, chromosomal rearrangements, and cell death. Our data demonstrated that combination of NO-donors with PARP inhibitors significantly sensitized the BRCA1-positive cancer cells to DNA-damaging agents.

  6. Regulation of Bone Morphogenetic Protein Signaling by ADP-ribosylation.

    Science.gov (United States)

    Watanabe, Yukihide; Papoutsoglou, Panagiotis; Maturi, Varun; Tsubakihara, Yutaro; Hottiger, Michael O; Heldin, Carl-Henrik; Moustakas, Aristidis

    2016-06-10

    We previously established a mechanism of negative regulation of transforming growth factor β signaling mediated by the nuclear ADP-ribosylating enzyme poly-(ADP-ribose) polymerase 1 (PARP1) and the deribosylating enzyme poly-(ADP-ribose) glycohydrolase (PARG), which dynamically regulate ADP-ribosylation of Smad3 and Smad4, two central signaling proteins of the pathway. Here we demonstrate that the bone morphogenetic protein (BMP) pathway can also be regulated by the opposing actions of PARP1 and PARG. PARG positively contributes to BMP signaling and forms physical complexes with Smad5 and Smad4. The positive role PARG plays during BMP signaling can be neutralized by PARP1, as demonstrated by experiments where PARG and PARP1 are simultaneously silenced. In contrast to PARG, ectopic expression of PARP1 suppresses BMP signaling, whereas silencing of endogenous PARP1 enhances signaling and BMP-induced differentiation. The two major Smad proteins of the BMP pathway, Smad1 and Smad5, interact with PARP1 and can be ADP-ribosylated in vitro, whereas PARG causes deribosylation. The overall outcome of this mode of regulation of BMP signal transduction provides a fine-tuning mechanism based on the two major enzymes that control cellular ADP-ribosylation. PMID:27129221

  7. Sex differences in minocycline-induced neuroprotection after experimental stroke

    OpenAIRE

    Li, Jun; McCullough, Louise D.

    2009-01-01

    Minocycline is neuroprotective in clinical and experimental stroke studies, due in part to its ability to inhibit poly (ADP-ribose) polymerase. Previous preclinical data have shown that interference with poly (ADP-ribose) polymerase signaling leads to sex-specific neuroprotection, reducing stroke injury only in males. In this study, we show that minocycline is ineffective at reducing ischemic damage in females after middle cerebral artery occlusion, likely due to effects on poly (ADP-ribose) ...

  8. In Vitro and In Vivo Enhancement of Chemoradiation Using the Oral PARP Inhibitor ABT-888 in Colorectal Cancer Cells

    Energy Technology Data Exchange (ETDEWEB)

    Shelton, Joseph W., E-mail: jwshelt@emory.edu [Department of Radiation Oncology, Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Waxweiler, Timothy V.; Landry, Jerome; Gao, Huiying; Xu, Yanbo; Wang, Lanfang [Department of Radiation Oncology, Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); El-Rayes, Bassel [Department of Hematology and Oncology, Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Shu, Hui-Kuo G. [Department of Radiation Oncology, Winship Cancer Institute, Emory University, Atlanta, Georgia (United States)

    2013-07-01

    Purpose: Poly(ADP-ribose) polymerase plays a critical role in the recognition and repair of DNA single-strand breaks and double-strand breaks (DSBs). ABT-888 is an orally available inhibitor of this enzyme. This study seeks to evaluate the use of ABT-888 combined with chemotherapy and radiation therapy (RT) in colorectal carcinoma models. Methods and Materials: RT clonogenic assays were performed on HCT116 and HT29 cells treated with 5-fluorouracil, irinotecan, or oxaliplatin with or without ABT. The surviving fraction at 2 Gy and dose-modifying factor at 10% survival were analyzed. Synergism was assessed by isobologram analysis for combination therapies. γH2AX and neutral comet assays were performed to assess the effect of therapy on DSB formation/repair. In vivo assessments were made by use of HCT116 cells in a xenograft mouse model. Tumor growth delay was measured at a volume of 500 mm{sup 3}. Results: Both lines were radiosensitized by ABT alone, and ABT further increased chemotherapy dose-modifying factors to the 1.6 to 1.8 range. All combinations were synergistic (combination indices <0.9). ABT treatment significantly increased DSB after RT (γH2AX, 69% vs 43%; P=.017) and delayed repair. We found tumor growth delays of 7.22 days for RT; 11.90 days for RT and ABT; 13.5 days for oxaliplatin, RT, and ABT; 14.17 days for 5-fluorouracil, RT, and ABT; and 23.81 days for irinotecan, RT, and ABT. Conclusion: ABT-888 radiosensitizes at similar or higher levels compared with classic chemotherapies and acts synergistically with these chemotherapies to enhance RT effects. In vivo confirmation of these results indicates a potential role for combining its use with existing chemoradiation regimens.

  9. In Vitro and In Vivo Enhancement of Chemoradiation Using the Oral PARP Inhibitor ABT-888 in Colorectal Cancer Cells

    International Nuclear Information System (INIS)

    Purpose: Poly(ADP-ribose) polymerase plays a critical role in the recognition and repair of DNA single-strand breaks and double-strand breaks (DSBs). ABT-888 is an orally available inhibitor of this enzyme. This study seeks to evaluate the use of ABT-888 combined with chemotherapy and radiation therapy (RT) in colorectal carcinoma models. Methods and Materials: RT clonogenic assays were performed on HCT116 and HT29 cells treated with 5-fluorouracil, irinotecan, or oxaliplatin with or without ABT. The surviving fraction at 2 Gy and dose-modifying factor at 10% survival were analyzed. Synergism was assessed by isobologram analysis for combination therapies. γH2AX and neutral comet assays were performed to assess the effect of therapy on DSB formation/repair. In vivo assessments were made by use of HCT116 cells in a xenograft mouse model. Tumor growth delay was measured at a volume of 500 mm3. Results: Both lines were radiosensitized by ABT alone, and ABT further increased chemotherapy dose-modifying factors to the 1.6 to 1.8 range. All combinations were synergistic (combination indices <0.9). ABT treatment significantly increased DSB after RT (γH2AX, 69% vs 43%; P=.017) and delayed repair. We found tumor growth delays of 7.22 days for RT; 11.90 days for RT and ABT; 13.5 days for oxaliplatin, RT, and ABT; 14.17 days for 5-fluorouracil, RT, and ABT; and 23.81 days for irinotecan, RT, and ABT. Conclusion: ABT-888 radiosensitizes at similar or higher levels compared with classic chemotherapies and acts synergistically with these chemotherapies to enhance RT effects. In vivo confirmation of these results indicates a potential role for combining its use with existing chemoradiation regimens

  10. Increased poly(ADP-ribosyl)ation in skeletal muscle tissue of pediatric patients with severe burn injury: prevention by propranolol treatment

    Science.gov (United States)

    Oláh, Gábor; Finnerty, Celeste; Sbrana, Elena; Elijah, Itoro; Gerö, Domokos; Herndon, David; Szabó, Csaba

    2011-01-01

    Summary Activation of the nuclear enzyme poly (ADP-ribose) polymerase (PARP) has been shown to promote cellular energetic collapse and cellular necrosis in various forms of critical illness. Most of the evidence implicating the PARP pathway in disease processes is derived from preclinical studies. With respect to PARP and burns, studies in rodent and large animal models of burn injury have demonstrated the activation of PARP in various tissues and the beneficial effect of its pharmacological inhibition. The aim of the current study was to measure the activation of PARP in human skeletal muscle biopsies at various stages of severe pediatric burn injury and to identify the cell types where this activation may occur. Another aim of the study was to test the effect of propranolol (an effective treatment of patients with burns), on the activation of PARP in skeletal muscle biopsies. PARP activation was measured by Western blotting for its product, poly(ADP-ribose) (PAR). The localization of PARP activation was determined by PAR immunohistochemistry. The results showed that PARP becomes activated in the skeletal muscle tissue after burns, with the peak of the activation occurring in the middle stage of the disease (13–18 days after burns). Even at the late stage of the disease (69–369 days post-burn) an elevated degree of PARP activation persisted in some of the patients. Immunohistochemical studies localized the staining of PAR primarily to vascular endothelial cells, and occasionally to resident mononuclear cells. There was a marked suppression of PARP activation in the skeletal muscle biopsies of patients who received propranolol treatment. We conclude that human burn injury is associated with the activation of PARP. We hypothesize that this response may contribute to the inflammatory responses and cell dysfunction in burns. Some of the clinical benefit of propranolol in burns may be related to its inhibitory effect on PARP activation. PMID:21368715

  11. Dual Roles for PARP1 during Heat Shock: Transcriptional Activator and Posttranscriptional Inhibitor of Gene Expression

    OpenAIRE

    Vyas, Sejal; Chang, Paul

    2013-01-01

    In this issue of Molecular Cell, Di Giammartino et al. (2012) identify a new function for PARP1 in the post-transcriptional regulation of mRNAs via ADP-ribosylation of poly(A) polymerase, a mRNA 3′ processing enzyme.

  12. The role of Kif4A in doxorubicin-induced apoptosis in breast cancer cells.

    Science.gov (United States)

    Wang, Hui; Lu, Changqing; Li, Qing; Xie, Jun; Chen, Tongbing; Tan, Yan; Wu, Changping; Jiang, Jingting

    2014-11-01

    This study was to investigate the mechanism and role of Kif4A in doxorubicin-induced apoptosis in breast cancer. Using two human breast cancer cell lines MCF-7 (with wild-type p53) and MDA-MB-231 (with mutant p53), we quantitated the expression levels of kinesin super-family protein 4A (Kif4A) and poly (ADP-ribose) Polymerase-1 (PARP-1) by Western blot after doxorubicin treatment and examined the apoptosis by flow cytometry after treatment with doxorubicin and PARP-1 inhibitor, 3-Aminobenzamide (3-ABA). Our results showed that doxorubicin treatment could induce the apoptosis of MCF-7 and MDA-MB-231 cells, the down-regulation of Kif4A and upregulation of poly(ADP-ribose) (PAR). The activity of PARP-1 or PARP-1 activation was significantly elevated by doxorubicin treatment in dose- and time-dependent manners (P 0.05). We further demonstrated that overexpression of Kif4A could reduce the level of PAR and significantly increase apoptosis. The effect of doxorubicin on apoptosis was more profound in MCF-7 cells compared with MDA-MB-231 cells (P breast cancer cells is achieved by inhibiting the activity of PARP-1. PMID:25377255

  13. Minor grove binding ligands disrupt PARP-1 activation pathways

    OpenAIRE

    Kirsanov, Kirill I.; Kotova, Elena; Makhov, Petr; Golovine, Konstantin; Lesovaya, Ekaterina A.; Kolenko, Vladimir M.; Yakubovskaya, Marianna G.; Tulin, Alexei V.

    2014-01-01

    PARP-1 is a nuclear enzyme regulating transcription, chromatin restructuring, and DNA repair. PARP-1 is activated by interaction with NAD+, DNA, and core histones. Each route of PARP-1 activation leads to somewhat different outcomes. PARP-1 interactions with core histones control PARP-1 functions during transcriptional activation in euchromatin. DNA-dependent regulation of PARP-1 determines its localization in heterochromatin and PARP-1-dependent silencing. Here we address the biological sign...

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

    Directory of Open Access Journals (Sweden)

    Ben Buelow

    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.

  15. Insights from the crystal structure of the sixth BRCT domain of topoisomerase IIβ binding protein 1

    OpenAIRE

    Leung, Charles Chung Yun; Kellogg, Elizabeth; Kuhnert, Anja; Hänel, Frank; Baker, David; Glover, J N Mark

    2009-01-01

    Topoisomerase IIβ binding protein 1 (TopBP1) is a major player in the DNA damage response and interacts with a number of protein partners via its eight BRCA1 carboxy-terminal (BRCT) domains. In particular, the sixth BRCT domain of TopBP1 has been implicated in binding to the phosphorylated transcription factor, E2F1, and poly(ADP-ribose) polymerase 1 (PARP-1), where the latter interaction is responsible for the poly(ADP-ribosyl)ation of TopBP1. To gain a better understanding of the nature of ...

  16. Synthesis of apoptotic chalcone analogues in HepG2 human hepatocellular carcinoma cells.

    Science.gov (United States)

    Park, Cheon-Soo; Ahn, Yongchel; Lee, Dahae; Moon, Sung Won; Kim, Ki Hyun; Yamabe, Noriko; Hwang, Gwi Seo; Jang, Hyuk Jai; Lee, Heesu; Kang, Ki Sung; Lee, Jae Wook

    2015-12-15

    Eight chalcone analogues were prepared and evaluated for their cytotoxic effects in human hepatoma HepG2 cells. Compound 5 had a potent cytotoxic effect. The percentage of apoptotic cells was significantly higher in compound 5-treated cells than in control cells. Exposure to compound 5 for 24h induced cleavage of caspase-8 and -3, and poly (ADP-ribose) polymerase (PARP). Our findings suggest that compound 5 is the active chalcone analogue that contributes to cell death in HepG2 cells via the extrinsic apoptotic pathway. PMID:26564263

  17. MVP and vaults: a role in the radiation response

    OpenAIRE

    Lara, P C; Pruschy, M; Zimmermann, M; Henríquez-Hernández, L A

    2011-01-01

    Vaults are evolutionary highly conserved ribonucleoproteins particles with a hollow barrel-like structure. The main component of vaults represents the 110 kDa major vault protein (MVP), whereas two minor vaults proteins comprise the 193 kDa vault poly(ADP-ribose) polymerase (vPARP) and the 240 kDa telomerase-associated protein-1 (TEP-1). Additionally, at least one small and untranslated RNA is found as a constitutive component. MVP seems to play an important role in the development of multidr...

  18. MVP and vaults: a role in the radiation response

    OpenAIRE

    Zimmermann Martina; Pruschy Martin; Lara Pedro C; Henríquez-Hernández Luis

    2011-01-01

    Abstract Vaults are evolutionary highly conserved ribonucleoproteins particles with a hollow barrel-like structure. The main component of vaults represents the 110 kDa major vault protein (MVP), whereas two minor vaults proteins comprise the 193 kDa vault poly(ADP-ribose) polymerase (vPARP) and the 240 kDa telomerase-associated protein-1 (TEP-1). Additionally, at least one small and untranslated RNA is found as a constitutive component. MVP seems to play an important role in the development o...

  19. Neuronal trauma model: in search of Thanatos.

    Science.gov (United States)

    Cole, Kasie; Perez-Polo, J Regino

    2004-11-01

    Trauma to the nervous system triggers responses that include oxidative stress due to the generation of reactive oxygen species (ROS). DNA is a major macromolecular target of ROS, and ROS-induced DNA strand breaks activate poly(ADP-ribose)polymerase-1 (PARP-1). Upon activation PARP-1 uses NAD(+) as a substrate to catalyze the transfer of ADP-ribose subunits to a host of nuclear proteins. In the face of extensive DNA strand breaks, PARP-1 activation can lead to depletion of intracellular NAD(P)(H) pools, large decreases in ATP, that threaten cell survival. Accordingly, inhibition of PARP-1 activity after acute oxidative injury has been shown to increase cell survival. When NGF-differentiated PC12 cells, an in vitro neuronal model, are exposed to H(2)O(2) there is increased synthesis of poly ADP-ribose and decreases in intracellular NAD(P)(H) and ATP. Addition of the chemical PARP inhibitor 3-aminobenzamide (AB) prior to H(2)O(2) exposure blocks the synthesis of poly ADP-ribose and maintains intracellular NAD(P)(H) and ATP levels. H(2)O(2) injury is characterized by an immediate, necrotic cell death 2h after injury and a delayed apoptotic-like death 12-24h after injury. This apoptotic-like death is characterized by apoptotic membrane changes and apoptotic DNA fragmentation but is not associated with measurable caspase-3 activity. AB delays cell death beyond 24h and increases cell survival by approximately 25%. This protective effect is accompanied by significantly decreased necrosis and the apoptotic-like death associated with H(2)O(2) exposure. AB also restores caspase-3 which can be attributed to the activation of the upstream activator of caspase-3, caspase-9. Thus, the maintenance of intracellular ATP levels associated with PARP-1 inhibition shifts cell death from necrosis to apoptosis and from apoptosis to cell survival. Furthermore, the shift from necrosis to apoptosis may be explained, in part, by an energy-dependent activation of caspase-9. PMID:15465278

  20. Parg deficiency confers radio-sensitization through enhanced cell death in mouse ES cells exposed to various forms of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Shirai, Hidenori; Fujimori, Hiroaki [Division of Genome Stability Research, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Gunji, Akemi [Biochemistry Division, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Maeda, Daisuke [Biochemistry Division, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); ADP-Ribosylation in Oncology Project, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Hirai, Takahisa [Division of Genome Stability Research, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Department of Radiation Oncology, Juntendo University Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Poetsch, Anna R. [ADP-Ribosylation in Oncology Project, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Harada, Hiromi [Division of Genome Stability Research, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Yoshida, Tomoko [Biochemistry Division, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Kyoritsu College of Pharmacy, 1-5-30 Shibakoen, Minatoku, Tokyo 105-8512 (Japan); Sasai, Keisuke [Department of Radiation Oncology, Juntendo University Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Okayasu, Ryuichi [International Open Laboratory, National Institute of Radiological Science, 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan); Masutani, Mitsuko, E-mail: mmasutan@ncc.go.jp [Division of Genome Stability Research, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); Biochemistry Division, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan); ADP-Ribosylation in Oncology Project, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045 (Japan)

    2013-05-24

    Highlights: •Parg{sup −/−} ES cells were more sensitive to γ-irradiation than Parp-1{sup −/−} ES cells. •Parg{sup −/−} cells were more sensitive to carbon-ion irradiation than Parp-1{sup −/−} cells. •Parg{sup −/−} cells showed defects in DSB repair after carbon-ion irradiation. •PAR accumulation was enhanced after carbon-ion irradiation compared to γ-irradiation. -- Abstract: Poly(ADP-ribose) glycohydrolase (Parg) is the main enzyme involved in poly(ADP-ribose) degradation. Here, the effects of Parg deficiency on sensitivity to low and high linear-energy-transfer (LET) radiation were investigated in mouse embryonic stem (ES) cells. Mouse Parg{sup −/−} and poly(ADP-ribose) polymerase-1 deficient (Parp-1{sup −/−}) ES cells were used and responses to low and high LET radiation were assessed by clonogenic survival and biochemical and biological analysis methods. Parg{sup −/−} cells were more sensitive to γ-irradiation than Parp-1{sup −/−} cells. Transient accumulation of poly(ADP-ribose) was enhanced in Parg{sup −/−} cells. Augmented levels of phosphorylated H2AX (γ-H2AX) from early phase were observed in Parg{sup −/−} ES cells. The induction level of p53 phophorylation at ser18 was similar in wild-type and Parp-1{sup −/−} cells and apoptotic cell death process was mainly observed in the both genotypes. These results suggested that the enhanced sensitivity of Parg{sup −/−} ES cells to γ-irradiation involved defective repair of DNA double strand breaks. The effects of Parg and Parp-1 deficiency on the ES cell response to carbon-ion irradiation (LET13 and 70 keV/μm) and Fe-ion irradiation (200 keV/μm) were also examined. Parg{sup −/−} cells were more sensitive to LET 70 keV/μm carbon-ion irradiation than Parp-1{sup −/−} cells. Enhanced apoptotic cell death also accompanied augmented levels of γ-H2AX in a biphasic manner peaked at 1 and 24 h. The induction level of p53 phophorylation at ser18 was

  1. Parg deficiency confers radio-sensitization through enhanced cell death in mouse ES cells exposed to various forms of ionizing radiation

    International Nuclear Information System (INIS)

    Highlights: •Parg−/− ES cells were more sensitive to γ-irradiation than Parp-1−/− ES cells. •Parg−/− cells were more sensitive to carbon-ion irradiation than Parp-1−/− cells. •Parg−/− cells showed defects in DSB repair after carbon-ion irradiation. •PAR accumulation was enhanced after carbon-ion irradiation compared to γ-irradiation. -- Abstract: Poly(ADP-ribose) glycohydrolase (Parg) is the main enzyme involved in poly(ADP-ribose) degradation. Here, the effects of Parg deficiency on sensitivity to low and high linear-energy-transfer (LET) radiation were investigated in mouse embryonic stem (ES) cells. Mouse Parg−/− and poly(ADP-ribose) polymerase-1 deficient (Parp-1−/−) ES cells were used and responses to low and high LET radiation were assessed by clonogenic survival and biochemical and biological analysis methods. Parg−/− cells were more sensitive to γ-irradiation than Parp-1−/− cells. Transient accumulation of poly(ADP-ribose) was enhanced in Parg−/− cells. Augmented levels of phosphorylated H2AX (γ-H2AX) from early phase were observed in Parg−/− ES cells. The induction level of p53 phophorylation at ser18 was similar in wild-type and Parp-1−/− cells and apoptotic cell death process was mainly observed in the both genotypes. These results suggested that the enhanced sensitivity of Parg−/− ES cells to γ-irradiation involved defective repair of DNA double strand breaks. The effects of Parg and Parp-1 deficiency on the ES cell response to carbon-ion irradiation (LET13 and 70 keV/μm) and Fe-ion irradiation (200 keV/μm) were also examined. Parg−/− cells were more sensitive to LET 70 keV/μm carbon-ion irradiation than Parp-1−/− cells. Enhanced apoptotic cell death also accompanied augmented levels of γ-H2AX in a biphasic manner peaked at 1 and 24 h. The induction level of p53 phophorylation at ser18 was not different between wild-type and Parg−/− cells. The augmented level of poly(ADP-ribose

  2. Interaction between PARP-1 and ATR in mouse fibroblasts is blocked by PARP inhibition

    OpenAIRE

    Kedar, Padmini S.; Stefanick, Donna F.; Horton, Julie K.; Wilson, Samuel H.

    2008-01-01

    Inhibition of PARP activity results in extreme sensitization to MMS-induced cell killing in cultured mouse fibroblasts. In these MMS-treated cells, PARP inhibition is accompanied by an accumulation of S-phase cells that requires signaling by the checkpoint kinase ATR (Horton et al. (2005) J. Biol. Chem., 280, 15773-15785). Here, we examined mouse fibroblast extracts for formation of a complex that may reflect association between the damage responsive proteins PARP-1 and ATR. Co-immunoprecipit...

  3. The BRCT domain of PARP-1 is required for immunoglobulin gene conversion.

    Directory of Open Access Journals (Sweden)

    Marcia N Paddock

    Full Text Available Genetic variation at immunoglobulin (Ig gene variable regions in B-cells is created through a multi-step process involving deamination of cytosine bases by activation-induced cytidine deaminase (AID and their subsequent mutagenic repair. To protect the genome from dangerous, potentially oncogenic effects of off-target mutations, both AID activity and mutagenic repair are targeted specifically to the Ig genes. However, the mechanisms of targeting are unknown and recent data have highlighted the role of regulating mutagenic repair to limit the accumulation of somatic mutations resulting from the more widely distributed AID-induced lesions to the Ig genes. Here we investigated the role of the DNA damage sensor poly-(ADPribose-polymerase-1 (PARP-1 in the repair of AID-induced DNA lesions. We show through sequencing of the diversifying Ig genes in PARP-1(-/- DT40 B-cells that PARP-1 deficiency results in a marked reduction in gene conversion events and enhanced high-fidelity repair of AID-induced lesions at both Ig heavy and light chains. To further characterize the role of PARP-1 in the mutagenic repair of AID-induced lesions, we performed functional analyses comparing the role of engineered PARP-1 variants in high-fidelity repair of DNA damage induced by methyl methane sulfonate (MMS and the mutagenic repair of lesions at the Ig genes induced by AID. This revealed a requirement for the previously uncharacterized BRCT domain of PARP-1 to reconstitute both gene conversion and a normal rate of somatic mutation at Ig genes, while being dispensable for the high-fidelity base excision repair. From these data we conclude that the BRCT domain of PARP-1 is required to initiate a significant proportion of the mutagenic repair specific to diversifying antibody genes. This role is distinct from the known roles of PARP-1 in high-fidelity DNA repair, suggesting that the PARP-1 BRCT domain has a specialized role in assembling mutagenic DNA repair complexes

  4. Structural basis of selective inhibition of human tankyrases.

    Science.gov (United States)

    Narwal, Mohit; Venkannagari, Harikanth; Lehtiö, Lari

    2012-02-01

    Tankyrases are poly(ADP-ribose) polymerases that have many cellular functions. They play pharmaceutically important roles, at least in telomere homeostasis and Wnt signaling, by covalently ADP-ribosylating target proteins and consequently regulating their functions. These features make tankyrases potential targets for treatment of cancer. We report here crystal structures of human tankyrase 2 catalytic fragment in complex with a byproduct, nicotinamide, and with selective inhibitors of tankyrases (IWR-1) and PARPs 1 and 2 (olaparib). Binding of these inhibitors to tankyrase 2 induces specific conformational changes. The crystal structures explain the selectivity of the inhibitors, reveal the flexibility of a substrate binding loop, and explain existing structure-activity relationship data. The first crystal structure of a PARP enzyme in complex with a potent inhibitor, IWR-1, that does not bind to the widely utilized nicotinamide-binding site makes the structure valuable for development of PARP inhibitors in general. PMID:22233320

  5. AcEST: DK958126 [AcEST

    Lifescience Database Archive (English)

    Full Text Available ment) OS=Xenopus laevis GN=parp1 PE=2 SV=1 Length = 998 Score = 67.8 bits (164), ...MVYSRWGRVGTR 206 >sp|O88554|PARP2_MOUSE Poly [ADP-ribose] polymerase 2 OS=Mus musculus GN=Parp2 PE=1 SV=3 Le...E0_PHYPA Predicted protein OS=Physcomitrella paten... 140 7e-32 tr|A2ZSW8|A2ZSW8_ORYSJ Putative unchar...3. 5' end sequence. DK958126 CL802Contig1 Show DK958126 Clone id TST39A01NGRL0030_C23 Library TST39 Length 5...AAGCGAAGTTTCTTGACAAAACTAGAAATACTTGGGCACAGAGAGCAAATTT ■■Homology search results ■■ - Swiss-Prot (release 56.9

  6. Mammalian Base Excision Repair: Functional Partnership between PARP-1 and APE1 in AP-Site Repair.

    Directory of Open Access Journals (Sweden)

    Rajendra Prasad

    Full Text Available The apurinic/apyrimidinic- (AP- site in genomic DNA arises through spontaneous base loss and base removal by DNA glycosylases and is considered an abundant DNA lesion in mammalian cells. The base excision repair (BER pathway repairs the AP-site lesion by excising and replacing the site with a normal nucleotide via template directed gap-filling DNA synthesis. The BER pathway is mediated by a specialized group of proteins, some of which can be found in multiprotein complexes in cultured mouse fibroblasts. Using a DNA polymerase (pol β immunoaffinity-capture technique to isolate such a complex, we identified five tightly associated and abundant BER factors in the complex: PARP-1, XRCC1, DNA ligase III, PNKP, and Tdp1. AP endonuclease 1 (APE1, however, was not present. Nevertheless, the complex was capable of BER activity, since repair was initiated by PARP-1's AP lyase strand incision activity. Addition of purified APE1 increased the BER activity of the pol β complex. Surprisingly, the pol β complex stimulated the strand incision activity of APE1. Our results suggested that PARP-1 was responsible for this effect, whereas other proteins in the complex had no effect on APE1 strand incision activity. Studies of purified PARP-1 and APE1 revealed that PARP-1 was able to stimulate APE1 strand incision activity. These results illustrate roles of PARP-1 in BER including a functional partnership with APE1.

  7. AcEST: DK949962 [AcEST

    Lifescience Database Archive (English)

    Full Text Available C1B2|PARPT_MOUSE TCDD-inducible poly [ADP-ribose] polymerase OS=Mus musculus GN=Tiparp PE=2 SV=1 Length = 65...olymerase 11 OS=Mus musculus GN=Parp11 PE=2 SV=1 Length = 331 Score = 45.1 bits (105), Expect = 3e-04 Identi...] polymerase 14 OS=Mus musculus GN=Parp14 PE=1 SV=2 Length = 1817 Score = 42.0 bits (97), Expect = 0.002 Ide...6. 5' end sequence. DK949962 - Show DK949962 Clone id TST38A01NGRL0007_G06 Library TST38 Length 593 Definiti...CAAACACAGGAAATTAACAGAG GCATTGACATGTTGGATGATTTTTGCAGATCTTATGATGTTTAGGAACGGAAG ■■Homology sear

  8. Emerging therapeutic roles for NAD(+) metabolism in mitochondrial and age-related disorders.

    Science.gov (United States)

    Srivastava, Sarika

    2016-12-01

    Nicotinamide adenine dinucleotide (NAD(+)) is a central metabolic cofactor in eukaryotic cells that plays a critical role in regulating cellular metabolism and energy homeostasis. NAD(+) in its reduced form (i.e. NADH) serves as the primary electron donor in mitochondrial respiratory chain, which involves adenosine triphosphate production by oxidative phosphorylation. The NAD(+)/NADH ratio also regulates the activity of various metabolic pathway enzymes such as those involved in glycolysis, Kreb's cycle, and fatty acid oxidation. Intracellular NAD(+) is synthesized de novo from L-tryptophan, although its main source of synthesis is through salvage pathways from dietary niacin as precursors. NAD(+) is utilized by various proteins including sirtuins, poly ADP-ribose polymerases (PARPs) and cyclic ADP-ribose synthases. The NAD(+) pool is thus set by a critical balance between NAD(+) biosynthetic and NAD(+) consuming pathways. Raising cellular NAD(+) content by inducing its biosynthesis or inhibiting the activity of PARP and cADP-ribose synthases via genetic or pharmacological means lead to sirtuins activation. Sirtuins modulate distinct metabolic, energetic and stress response pathways, and through their activation, NAD(+) directly links the cellular redox state with signaling and transcriptional events. NAD(+) levels decline with mitochondrial dysfunction and reduced NAD(+)/NADH ratio is implicated in mitochondrial disorders, various age-related pathologies as well as during aging. Here, I will provide an overview of the current knowledge on NAD(+) metabolism including its biosynthesis, utilization, compartmentalization and role in the regulation of metabolic homoeostasis. I will further discuss how augmenting intracellular NAD(+) content increases oxidative metabolism to prevent bioenergetic and functional decline in multiple models of mitochondrial diseases and age-related disorders, and how this knowledge could be translated to the clinic for human relevance. PMID

  9. How to kill tumor cells with inhibitors of poly(ADP-ribosyl)ation.

    Science.gov (United States)

    Mangerich, Aswin; Bürkle, Alexander

    2011-01-15

    Poly(ADP-ribosyl)ation is a post-translational modification catalyzed by the enzyme family of poly(ADP-ribose) polymerases (PARPs). PARPs exhibit pleiotropic cellular functions ranging from maintenance of genomic stability and chromatin remodeling to regulation of cell death, thereby rendering PARP homologues promising targets in cancer therapy. Depending on the molecular status of a cancer cell, low-molecular weight PARP inhibitors can (i) either be used as monotherapeutic agents following the concept of synthetic lethality or (ii) to support classical chemotherapy or radiotherapy. The rationales are the following: (i) in cancers with selective defects in homologous recombination repair, inactivation of PARPs directly causes cell death. In cancer treatment, this phenomenon can be employed to specifically target tumor cells while sparing nonmalignant tissue. (ii) PARP inhibitors can also be used to sensitize cells to cytotoxic DNA-damaging treatments, as some PARPs actively participate in genomic maintenance. Apart from that, PARP inhibitors possess antiangiogenic functions, thus opening up a further option to inhibit tumor growth. In view of the above, a number of high-potency PARP inhibitors have been developed during the last decade and are currently evaluated as cancer therapeutics in clinical trials by several leading pharmaceutical companies. PMID:20853319

  10. 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...

  11. Evaluation and Structural Basis for the Inhibition of Tankyrases by PARP Inhibitors.

    Science.gov (United States)

    Haikarainen, Teemu; Narwal, Mohit; Joensuu, Päivi; Lehtiö, Lari

    2014-01-01

    Tankyrases, an enzyme subfamily of human poly(ADP-ribosyl)polymerases, are potential drug targets especially against cancer. We have evaluated inhibition of tankyrases by known PARP inhibitors and report five cocrystal structures of the most potent compounds in complex with human tankyrase 2. The inhibitors include the small general PARP inhibitors Phenanthridinone, PJ-34, and TIQ-A as well as the more advanced inhibitors EB-47 and rucaparib. The compounds anchor to the nicotinamide subsite of tankyrase 2. Crystal structures reveal flexibility of the ligand binding site with implications for drug development against tankyrases and other ADP-ribosyltransferases. EB-47 mimics the substrate NAD(+) and extends from the nicotinamide to the adenosine subsite. The clinical ARTD1 inhibitor candidate rucaparib was the most potent tankyrase inhibitor identified (24 and 14 nM for tankyrases), which indicates that inhibition of tankyrases would affect the cellular responses of this compound. PMID:24900770

  12. 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. PMID:26880244

  13. Liquid demixing of intrinsically disordered proteins is seeded by poly(ADP-ribose)

    DEFF Research Database (Denmark)

    Altmeyer, Matthias; Neelsen, Kai J; Teloni, Federico;

    2015-01-01

    Intrinsically disordered proteins can phase separate from the soluble intracellular space, and tend to aggregate under pathological conditions. The physiological functions and molecular triggers of liquid demixing by phase separation are not well understood. Here we show in vitro and in vivo...... disordered proteins at DNA break sites. Demixing, which relies on electrostatic interactions between positively charged RGG repeats and negatively charged PAR, is amplified by aggregation-prone prion-like domains, and orchestrates the earliest cellular responses to DNA breakage. We propose that PAR......-seeded liquid demixing is a general mechanism to dynamically reorganize the soluble nuclear space with implications for pathological protein aggregation caused by derailed phase separation....

  14. DEK Is a Poly(ADP-Ribose) Acceptor in Apoptosis and Mediates Resistance to Genotoxic Stress

    OpenAIRE

    Kappes, Ferdinand; Fahrer, Jörg; Khodadoust, Michael A.; Tabbert, Anja; Strasser, Christine; Mor-Vaknin, Nirit; Moreno-Villanueva, María; Bürkle, Alexander; Markovitz, David M; May, Elisa

    2008-01-01

    DEK is a nuclear phosphoprotein implicated in oncogenesis and autoimmunity and a major component of metazoan chromatin. The intracellular cues that control the binding of DEK to DNA and its pleiotropic functions in DNA- and RNA-dependent processes have remained mainly elusive so far. Our recent finding that the phosphorylation status of DEK is altered during death receptor-mediated apoptosis suggested a potential involvement of DEK in stress signaling. In this study, we show that in cells com...

  15. Hyper-active non-homologous end joining selects for synthetic lethality resistant and pathological Fanconi anemia hematopoietic stem and progenitor cells.

    Science.gov (United States)

    Du, Wei; Amarachintha, Surya; Wilson, Andrew F; Pang, Qishen

    2016-01-01

    The prominent role of Fanconi anemia (FA) proteins involves homologous recombination (HR) repair. Poly[ADP-ribose] polymerase1 (PARP1) functions in multiple cellular processes including DNA repair and PARP inhibition is an emerging targeted therapy for cancer patients deficient in HR. Here we show that PARP1 activation in hematopoietic stem and progenitor cells (HSPCs) in response to genotoxic or oxidative stress attenuates HSPC exhaustion. Mechanistically, PARP1 controls the balance between HR and non-homologous end joining (NHEJ) in double strand break (DSB) repair by preventing excessive NHEJ. Disruption of the FA core complex skews PARP1 function in DSB repair and led to hyper-active NHEJ in Fanca(-/-) or Fancc(-/-) HSPCs. Re-expression of PARP1 rescues the hyper-active NHEJ phenotype in Brca1(-/-)Parp1(-/-) but less effective in Fanca(-/-)Parp1(-/-) cells. Inhibition of NHEJ prevents myeloid/erythroid pathologies associated with synthetic lethality. Our results suggest that hyper-active NHEJ may select for "synthetic lethality" resistant and pathological HSPCs. PMID:26916217

  16. Role of Nicotinamide in DNA Damage, Mutagenesis, and DNA Repair

    Directory of Open Access Journals (Sweden)

    Devita Surjana

    2010-01-01

    Full Text Available Nicotinamide is a water-soluble amide form of niacin (nicotinic acid or vitamin B3. Both niacin and nicotinamide are widely available in plant and animal foods, and niacin can also be endogenously synthesized in the liver from dietary tryptophan. Nicotinamide is also commercially available in vitamin supplements and in a range of cosmetic, hair, and skin preparations. Nicotinamide is the primary precursor of nicotinamide adenine dinucleotide (NAD+, an essential coenzyme in ATP production and the sole substrate of the nuclear enzyme poly-ADP-ribose polymerase-1 (PARP-1. Numerous in vitro and in vivo studies have clearly shown that PARP-1 and NAD+ status influence cellular responses to genotoxicity which can lead to mutagenesis and cancer formation. This paper will examine the role of nicotinamide in the protection from carcinogenesis, DNA repair, and maintenance of genomic stability.

  17. Data on four apoptosis-related genes in the colonial tunicate Botryllus schlosseri.

    Science.gov (United States)

    Franchi, Nicola; Ballin, Francesca; Manni, Lucia; Schiavon, Filippo; Ballarin, Loriano

    2016-09-01

    The data described are related to the article entitled "Recurrent phagocytosis-induced apoptosis in the cyclical generation change of the compound ascidian Botryllus schlosseri" (Franchi et al., 2016) [1]. Four apoptosis-related genes, showing high similarity with mammalian Bax (a member of the Bcl-2 protein family), AIF1 (apoptosis-inducing factor-1), PARP1 (poly ADP ribose polymerase-1) and IAP7 (inhibitor of apoptosis-7) were identified from the analysis of the trascriptome of B. schlosseri. They were named BsBax, BsAIF1, BsPARP1 and BsIAP7. Here, their deduced amino acid sequence were compared with known sequences of orthologous genes from other deuterostome species together with a study of their identity/similarity. PMID:27294183

  18. PARP Inhibitors in Epithelial Ovarian Cancer: State of Art and Perspectives of Clinical Research.

    Science.gov (United States)

    Gadducci, Angiolo; Guerrieri, Maria Elena

    2016-05-01

    Homologous recombination (HR) and base excision repair (BER) are two of the major DNA-repair pathways. The proteins encoded by breast-related cancer antigen (BRCA) and poly(adenosine diphosphate-ribose) polymerases (PARP) are involved in HR and BER, respectively. Tumors with HR deficiency, including those in BRCA mutation carriers, are sensitive to BER blockade via PARP inhibitors. These represent novel therapeutic tools for HR-deficient ovarian cancer, able to improve progression-free survival of women with recurrent, platinum-sensitive disease in response to recent platinum-based chemotherapy. More research is needed to assesses whether inhibitors of PARP have any role as maintenance treatment after first-line chemotherapy and as palliative treatment of platinum-resistant disease. Germline BRCA testing should be offered to all patients with ovarian cancer, regardless of age and family history. HR deficiency has been observed not only in germline BRCA mutation carriers, but also in patients with somatic mutations or epigenetic silencing of BRCA, and with loss of function of other genes. Half of all high-grade ovarian carcinomas are HR-deficient, and additional biological and clinical investigations are strongly warranted to identify patients with this subset of tumors. PMID:27127105

  19. Profile of olaparib in the treatment of advanced ovarian cancer

    Science.gov (United States)

    Chase, Dana M; Patel, Shreya; Shields, Kristin

    2016-01-01

    Olaparib is a poly(ADP-ribose) polymerase inhibitor that received accelerated approval from the US Food and Drug Administration as monotherapy for patients with germline BRCA mutations and ovarian cancer treated with three or more prior lines of chemotherapy. This article summarizes the mechanism of poly(ADP-ribose) polymerase inhibition, therapeutic profile and uses of olaparib, and current and ongoing literature pertaining to olaparib in advanced ovarian cancer. PMID:27186080

  20. Analysis list: Parp1 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Parp1 Neural + mm9 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Parp1.1.tsv http://dbar...chive.biosciencedbc.jp/kyushu-u/mm9/target/Parp1.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Par...p1.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Parp1.Neural.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Neural.gml ...

  1. Analysis list: PARP1 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available PARP1 Breast + hg19 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/PARP1.1.tsv http://dbar...chive.biosciencedbc.jp/kyushu-u/hg19/target/PARP1.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/PAR...P1.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/PARP1.Breast.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/Breast.gml ...

  2. HPF1/C4orf27 Is a PARP-1-Interacting Protein that Regulates PARP-1 ADP-Ribosylation Activity

    OpenAIRE

    Gibbs-Seymour, Ian; Fontana, Pietro; Rack, Johannes Gregor Matthias; Ahel, Ivan

    2016-01-01

    Summary We report the identification of histone PARylation factor 1 (HPF1; also known as C4orf27) as a regulator of ADP-ribosylation signaling in the DNA damage response. HPF1/C4orf27 forms a robust protein complex with PARP-1 in cells and is recruited to DNA lesions in a PARP-1-dependent manner, but independently of PARP-1 catalytic ADP-ribosylation activity. Functionally, HPF1 promotes PARP-1-dependent in trans ADP-ribosylation of histones and limits DNA damage-induced hyper-automodificatio...

  3. Oxaliplatin triggers necrosis as well as apoptosis in gastric cancer SGC-7901 cells

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Ping; Zhu, Xueping [Department of Immunology, Anhui Medical University, Hefei 230032 (China); Jin, Wei [Department of Otolaryngology, Chaohu Hospital of Anhui Medical University, Chaohu 238000 (China); Hao, Shumei; Liu, Qi [Department of Immunology, Anhui Medical University, Hefei 230032 (China); Zhang, Linjie, E-mail: zlj33@ahmu.edu.cn [Department of Immunology, Anhui Medical University, Hefei 230032 (China)

    2015-05-01

    Intrinsic apoptotic pathway is considered to be responsible for cell death induced by platinum anticancer drugs. While in this study, we found that, necrosis is an indispensable pathway besides apoptosis in oxaliplatin-treated gastric cancer SGC-7901 cells. Upon exposure to oxaliplatin, both apoptotic and necrotic features were observed. The majority of dead cells were double positive for Annexin V and propidium iodide (PI). Moreover, mitochondrial membrane potential collapsed and caspase cascades were activated. However, ultrastructural changes under transmission electron microscope, coupled with the release of cellular contents, demonstrated the rupture of the plasma membrane. Oxaliplatin administration did not stimulate reactive oxygen species (ROS) production and autophagy, but elevated the protein level of Bmf. In addition, receptor interacting protein 1 (RIP1), but not receptor interacting protein 3 (RIP3) and its downstream components participated in this death process. Necrostatin-1 (Nec-1) blocked oxaliplatin-induced cell death nearly completely, whereas z-VAD-fmk could partially suppress cell death. Oxaliplatin treatment resulted in poly(ADP-ribose) polymerase-1 (PARP-1) overactivation, as indicated by the increase of poly(ADP-ribose) (PAR), which led to NAD{sup +} and ATP depletion. PARP-1 inhibitor, olaparib, could significantly block oxaliplatin-induced cell death, thus confirming that PARP-1 activation is mainly responsible for the cytotoxicity of oxaliplatin. Phosphorylation of H2AX at Ser139 and translocalization of apoptosis-inducing factor (AIF) are critical for this death process. Taken together, these results indicate that oxaliplatin can bypass canonical cell death pathways to kill gastric cancer cells, which may be of therapeutic advantage in the treatment of gastric cancer. - Highlights: • Oxaliplatin induces apoptotic and necrotic cell death. • Nec-1 can inhibit oxaliplatin-induced cell death nearly completely. • RIP3 and its

  4. Oxaliplatin triggers necrosis as well as apoptosis in gastric cancer SGC-7901 cells

    International Nuclear Information System (INIS)

    Intrinsic apoptotic pathway is considered to be responsible for cell death induced by platinum anticancer drugs. While in this study, we found that, necrosis is an indispensable pathway besides apoptosis in oxaliplatin-treated gastric cancer SGC-7901 cells. Upon exposure to oxaliplatin, both apoptotic and necrotic features were observed. The majority of dead cells were double positive for Annexin V and propidium iodide (PI). Moreover, mitochondrial membrane potential collapsed and caspase cascades were activated. However, ultrastructural changes under transmission electron microscope, coupled with the release of cellular contents, demonstrated the rupture of the plasma membrane. Oxaliplatin administration did not stimulate reactive oxygen species (ROS) production and autophagy, but elevated the protein level of Bmf. In addition, receptor interacting protein 1 (RIP1), but not receptor interacting protein 3 (RIP3) and its downstream components participated in this death process. Necrostatin-1 (Nec-1) blocked oxaliplatin-induced cell death nearly completely, whereas z-VAD-fmk could partially suppress cell death. Oxaliplatin treatment resulted in poly(ADP-ribose) polymerase-1 (PARP-1) overactivation, as indicated by the increase of poly(ADP-ribose) (PAR), which led to NAD+ and ATP depletion. PARP-1 inhibitor, olaparib, could significantly block oxaliplatin-induced cell death, thus confirming that PARP-1 activation is mainly responsible for the cytotoxicity of oxaliplatin. Phosphorylation of H2AX at Ser139 and translocalization of apoptosis-inducing factor (AIF) are critical for this death process. Taken together, these results indicate that oxaliplatin can bypass canonical cell death pathways to kill gastric cancer cells, which may be of therapeutic advantage in the treatment of gastric cancer. - Highlights: • Oxaliplatin induces apoptotic and necrotic cell death. • Nec-1 can inhibit oxaliplatin-induced cell death nearly completely. • RIP3 and its downstream

  5. Carnosine and its possible roles in nutrition and health.

    Science.gov (United States)

    Hipkiss, Alan R

    2009-01-01

    The dipeptide carnosine has been observed to exert antiaging activity at cellular and whole animal levels. This review discusses the possible mechanisms by which carnosine may exert antiaging action and considers whether the dipeptide could be beneficial to humans. Carnosine's possible biological activities include scavenger of reactive oxygen species (ROS) and reactive nitrogen species (RNS), chelator of zinc and copper ions, and antiglycating and anticross-linking activities. Carnosine's ability to react with deleterious aldehydes such as malondialdehyde, methylglyoxal, hydroxynonenal, and acetaldehyde may also contribute to its protective functions. Physiologically carnosine may help to suppress some secondary complications of diabetes, and the deleterious consequences of ischemic-reperfusion injury, most likely due to antioxidation and carbonyl-scavenging functions. Other, and much more speculative, possible functions of carnosine considered include transglutaminase inhibition, stimulation of proteolysis mediated via effects on proteasome activity or induction of protease and stress-protein gene expression, upregulation of corticosteroid synthesis, stimulation of protein repair, and effects on ADP-ribose metabolism associated with sirtuin and poly-ADP-ribose polymerase (PARP) activities. Evidence for carnosine's possible protective action against secondary diabetic complications, neurodegeneration, cancer, and other age-related pathologies is briefly discussed. PMID:19595386

  6. Tankyrases Promote Homologous Recombination and Check Point Activation in Response to DSBs.

    Directory of Open Access Journals (Sweden)

    Zita Nagy

    2016-02-01

    Full Text Available DNA lesions are sensed by a network of proteins that trigger the DNA damage response (DDR, a signaling cascade that acts to delay cell cycle progression and initiate DNA repair. The Mediator of DNA damage Checkpoint protein 1 (MDC1 is essential for spreading of the DDR signaling on chromatin surrounding Double Strand Breaks (DSBs by acting as a scaffold for PI3K kinases and for ubiquitin ligases. MDC1 also plays a role both in Non-Homologous End Joining (NHEJ and Homologous Recombination (HR repair pathways. Here we identify two novel binding partners of MDC1, the poly (ADP-ribose Polymerases (PARPs TNKS1 and 2. We find that TNKSs are recruited to DNA lesions by MDC1 and regulate DNA end resection and BRCA1A complex stabilization at lesions leading to efficient DSB repair by HR and proper checkpoint activation.

  7. Tankyrases Promote Homologous Recombination and Check Point Activation in Response to DSBs.

    Science.gov (United States)

    Nagy, Zita; Kalousi, Alkmini; Furst, Audrey; Koch, Marc; Fischer, Benoit; Soutoglou, Evi

    2016-02-01

    DNA lesions are sensed by a network of proteins that trigger the DNA damage response (DDR), a signaling cascade that acts to delay cell cycle progression and initiate DNA repair. The Mediator of DNA damage Checkpoint protein 1 (MDC1) is essential for spreading of the DDR signaling on chromatin surrounding Double Strand Breaks (DSBs) by acting as a scaffold for PI3K kinases and for ubiquitin ligases. MDC1 also plays a role both in Non-Homologous End Joining (NHEJ) and Homologous Recombination (HR) repair pathways. Here we identify two novel binding partners of MDC1, the poly (ADP-ribose) Polymerases (PARPs) TNKS1 and 2. We find that TNKSs are recruited to DNA lesions by MDC1 and regulate DNA end resection and BRCA1A complex stabilization at lesions leading to efficient DSB repair by HR and proper checkpoint activation. PMID:26845027

  8. Induction of intrachromosomal homologous recombination in whole plants

    International Nuclear Information System (INIS)

    The influence of different factors on frequencies of intrachromosomal homologous recombination in whole Arabidopsis thaliana and tobacco plants was analyzed using a disrupted β-glucuronidase marker gene. Recombination frequencies were enhanced several fold by DNA damaging agents like UV-light or MMS (methyl methanesulfonate). Applying 3-methoxybenzamide (3-MB), an inhibitor of poly(ADP)ribose polymerase (PARP), an enzyme that is postulated to be involved in DNA repair, enhanced homologous recombination frequencies strongly. These findings indicate that homologous recombination is involved in DNA repair and can (at least partially) compensate for other DNA repair pathways. Indications that recombination in plants can be induced by environmental stress factors that are not likely to be involved in DNA metabolism were also found; Arabidopsis plants growing in a medium containing 0.1 M NaCl exhibited elevated recombination frequencies. The possible general effects of ‘environmental’ challenges on genome flexibility are discussed. (author)

  9. Development of novel dual binders as potent, selective, and orally bioavailable tankyrase inhibitors.

    Science.gov (United States)

    Hua, Zihao; Bregman, Howard; Buchanan, John L; Chakka, Nagasree; Guzman-Perez, Angel; Gunaydin, Hakan; Huang, Xin; Gu, Yan; Berry, Virginia; Liu, Jingzhou; Teffera, Yohannes; Huang, Liyue; Egge, Bryan; Emkey, Renee; Mullady, Erin L; Schneider, Steve; Andrews, Paul S; Acquaviva, Lisa; Dovey, Jennifer; Mishra, Ankita; Newcomb, John; Saffran, Douglas; Serafino, Randy; Strathdee, Craig A; Turci, Susan M; Stanton, Mary; Wilson, Cindy; Dimauro, Erin F

    2013-12-27

    Tankyrases (TNKS1 and TNKS2) are proteins in the poly ADP-ribose polymerase (PARP) family. They have been shown to directly bind to axin proteins, which negatively regulate the Wnt pathway by promoting β-catenin degradation. Inhibition of tankyrases may offer a novel approach to the treatment of APC-mutant colorectal cancer. Hit compound 8 was identified as an inhibitor of tankyrases through a combination of substructure searching of the Amgen compound collection based on a minimal binding pharmacophore hypothesis and high-throughput screening. Herein we report the structure- and property-based optimization of compound 8 leading to the identification of more potent and selective tankyrase inhibitors 22 and 49 with improved pharmacokinetic properties in rodents, which are well suited as tool compounds for further in vivo validation studies. PMID:24294969

  10. Anti-lipid peroxidation and induction of apoptosis in the erythroleukaemic cell line K562 by extracts from (Tunisian) Rhamnus alaternus L. (Rhamnaceae).

    Science.gov (United States)

    Ammar, Rebai Ben; Neffati, Aicha; Skandrani, Ines; Sghaier, Mohamed Ben; Bhouri, Wissem; Ghedira, Kamel; Chekir-Ghedira, Leila

    2011-07-01

    Total oligomer flavonoids (TOF) enriched and ethyl acetate (EA) extracts from Rhamnus alaternus induce apoptotic death in human chronic myelogenous leukaemia K562 cell line, as demonstrated by gel electrophoresis, which demonstrates the characteristic ladder patterns of DNA fragmentation and the proteolytic cleavage of poly(ADP ribose) polymerase (PARP). The effect of R. alaternus extract in reducing oxidative stress was evaluated by anti-lipid peroxidation which was monitored by measuring malondialdehyde level in K562 cultured cells. The TOF and EA extracts were found to be effective to protect against lipid peroxidation. Their IC₅₀ values were 196 and 273 µg mL⁻¹, respectively. These findings suggest that R. alaternus extracts exhibit potential antioxidant and proapoptotic properties. PMID:21726127

  11. Breast cancer in BRCA mutation carriers: medical treatment.

    Science.gov (United States)

    Milani, Andrea; Geuna, Elena; Zucchini, Giorgia; Aversa, Caterina; Martinello, Rossella; Montemurro, Filippo

    2016-10-01

    About 10% of breast cancers are associated with the inheritance of autosomal dominant breast cancer susceptibility alleles BRCA1 and BRCA2. Until recently, the medical management of BRCA mutation-associated breast cancer has not differed from that of the sporadic breast cancer counterpart. However, there is mounting evidence that this molecular alteration confers sensitivity or resistance to systemic therapies that can be exploited in terms of medical management. For example, studies support the use of platinum salts chemotherapy in BRCA mutated cancers. Moreover, a number of targeted therapies are showing activity in BRCA mutation carriers. Above all, BRCA defective tumor cells are particularly sensitive to Poly(ADP-ribose) polymerase (PARP) inhibitors. This review will summarize the state of the art of the medical treatment of breast cancer in BRCA mutation carriers, with a particular focus on chemotherapies and targeted therapies. PMID:26799758

  12. The Sarin-like Organophosphorus Agent bis (isopropyl methyl)phosphonate Induces Apoptotic Cell Death and COX-2 Expression in SK-N-SH Cells.

    Science.gov (United States)

    Arima, Yosuke; Yoshimoto, Kanji; Namera, Akira; Makita, Ryosuke; Murata, Kazuhiro; Nagao, Masataka

    2016-03-01

    Organophosphorus compounds, such as sarin, are highly toxic nerve agents that inhibit acetylcholinesterase (AChE), but not cholinesterase, via multiple mechanisms. Recent studies have shown that organophosphorus compounds increase cyclooxygenase-2 (COX-2) expression and induce neurotoxicity. In this study, we examined the toxicity of the sarin-like organophosphorus agent bis(isopropyl methyl)phosphonate (BIMP) and the effects of BIMP on COX-2 expression in SK-N-SH human neuroblastoma cells. Exposure to BIMP changed cell morphology and induced caspase-dependent apoptotic cell death accompanied by cleavage of caspase 3, caspase 9, and poly (ADP-ribose) polymerase (PARP). It also increased COX-2 expression, while pretreatment with a COX inhibitor, ibuprofen, decreased BIMP-dependent cell death and COX-2 expression in SK-N-SH cells. Thus, our findings suggest that BIMP induces apoptotic cell death and upregulates COX-2 expression. PMID:27348899

  13. Pheophorbide a mediated photodynamic therapy against human epidermoid carcinoma cells (A431)

    Science.gov (United States)

    Chen, Yi-Chun; Li, Wen-Tyng

    2011-02-01

    The objective of this study was to characterize the death mechanism of human epidermoid carcinoma cells (A431) triggered by photodynamic therapy (PDT) with pheophorbide a. First of all, significant inhibition on the survival of A431 cells (N-Acetyl cysteine prevented ROS production and increased cell survival thereafter. The decrease in cellular ATP level was also observed at 6 hrs after PDT. Typical apoptotic cellular morphology and a collapse of mitochondrial membrane potential occurred after PDT. The loss of mitochondrial membrane potential led to the release of cytochrome c from the mitochondria to the cytosol, followed by activation of caspase-9 and caspase-3. The activation of caspase-3 resulted in poly(ADP-ribose) polymerase (PARP) cleavage in A431 cells, followed by DNA fragmentation. In conclusion, the results demonstrated that pheophorbide a possessed photodynamic action against A431 cells, mainly through apoptosis mediated by mitochondrial intrinsic pathway triggered by ROS.

  14. 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

  15. PARP inhibition restores extrinsic apoptotic sensitivity in glioblastoma.

    Directory of Open Access Journals (Sweden)

    Georg Karpel-Massler

    Full Text Available 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.

  16. Parp3 negatively regulates immunoglobulin class switch recombination.

    Science.gov (United States)

    Robert, Isabelle; Gaudot, Léa; Rogier, Mélanie; Heyer, Vincent; Noll, Aurélia; Dantzer, Françoise; Reina-San-Martin, Bernardo

    2015-05-01

    To generate highly specific and adapted immune responses, B cells diversify their antibody repertoire through mechanisms involving the generation of programmed DNA damage. Somatic hypermutation (SHM) and class switch recombination (CSR) are initiated by the recruitment of activation-induced cytidine deaminase (AID) to immunoglobulin loci and by the subsequent generation of DNA lesions, which are differentially processed to mutations during SHM or to double-stranded DNA break intermediates during CSR. The latter activate the DNA damage response and mobilize multiple DNA repair factors, including Parp1 and Parp2, to promote DNA repair and long-range recombination. We examined the contribution of Parp3 in CSR and SHM. We find that deficiency in Parp3 results in enhanced CSR, while SHM remains unaffected. Mechanistically, this is due to increased occupancy of AID at the donor (Sμ) switch region. We also find evidence of increased levels of DNA damage at switch region junctions and a bias towards alternative end joining in the absence of Parp3. We propose that Parp3 plays a CSR-specific role by controlling AID levels at switch regions during CSR. PMID:26000965

  17. Parp3 negatively regulates immunoglobulin class switch recombination.

    Directory of Open Access Journals (Sweden)

    Isabelle Robert

    2015-05-01

    Full Text Available To generate highly specific and adapted immune responses, B cells diversify their antibody repertoire through mechanisms involving the generation of programmed DNA damage. Somatic hypermutation (SHM and class switch recombination (CSR are initiated by the recruitment of activation-induced cytidine deaminase (AID to immunoglobulin loci and by the subsequent generation of DNA lesions, which are differentially processed to mutations during SHM or to double-stranded DNA break intermediates during CSR. The latter activate the DNA damage response and mobilize multiple DNA repair factors, including Parp1 and Parp2, to promote DNA repair and long-range recombination. We examined the contribution of Parp3 in CSR and SHM. We find that deficiency in Parp3 results in enhanced CSR, while SHM remains unaffected. Mechanistically, this is due to increased occupancy of AID at the donor (Sμ switch region. We also find evidence of increased levels of DNA damage at switch region junctions and a bias towards alternative end joining in the absence of Parp3. We propose that Parp3 plays a CSR-specific role by controlling AID levels at switch regions during CSR.

  18. E1B and E4 oncoproteins of adenovirus antagonize the effect of apoptosis inducing factor

    International Nuclear Information System (INIS)

    Adenovirus inundates the productively infected cell with linear, double-stranded DNA and an abundance of single-stranded DNA. The cellular response to this stimulus is antagonized by the adenoviral E1B and E4 early genes. A mutant group C adenovirus that fails to express the E1B-55K and E4ORF3 genes is unable to suppress the DNA-damage response. Cells infected with this double-mutant virus display significant morphological heterogeneity at late times of infection and frequently contain fragmented nuclei. Nuclear fragmentation was due to the translocation of apoptosis inducing factor (AIF) from the mitochondria into the nucleus. The release of AIF was dependent on active poly(ADP-ribose) polymerase-1 (PARP-1), which appeared to be activated by viral DNA replication. Nuclear fragmentation did not occur in AIF-deficient cells or in cells treated with a PARP-1 inhibitor. The E1B-55K or E4ORF3 proteins independently prevented nuclear fragmentation subsequent to PARP-1 activation, possibly by altering the intracellular distribution of PAR-modified proteins. - Highlights: • E1B-55K or E4orf3 prevents nuclear fragmentation. • Nuclear fragmentation requires AIF and PARP-1 activity. • Adenovirus DNA replication activates PARP-1. • E1B-55K or E4orf3 proteins alter the distribution of PAR

  19. E1B and E4 oncoproteins of adenovirus antagonize the effect of apoptosis inducing factor

    Energy Technology Data Exchange (ETDEWEB)

    Turner, Roberta L. [Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC 27157 (United States); Wilkinson, John C., E-mail: john.wilkinson@ndsu.edu [Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC 27157 (United States); Ornelles, David A., E-mail: ornelles@wakehealth.edu [Department of Microbiology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC 27157 (United States)

    2014-05-15

    Adenovirus inundates the productively infected cell with linear, double-stranded DNA and an abundance of single-stranded DNA. The cellular response to this stimulus is antagonized by the adenoviral E1B and E4 early genes. A mutant group C adenovirus that fails to express the E1B-55K and E4ORF3 genes is unable to suppress the DNA-damage response. Cells infected with this double-mutant virus display significant morphological heterogeneity at late times of infection and frequently contain fragmented nuclei. Nuclear fragmentation was due to the translocation of apoptosis inducing factor (AIF) from the mitochondria into the nucleus. The release of AIF was dependent on active poly(ADP-ribose) polymerase-1 (PARP-1), which appeared to be activated by viral DNA replication. Nuclear fragmentation did not occur in AIF-deficient cells or in cells treated with a PARP-1 inhibitor. The E1B-55K or E4ORF3 proteins independently prevented nuclear fragmentation subsequent to PARP-1 activation, possibly by altering the intracellular distribution of PAR-modified proteins. - Highlights: • E1B-55K or E4orf3 prevents nuclear fragmentation. • Nuclear fragmentation requires AIF and PARP-1 activity. • Adenovirus DNA replication activates PARP-1. • E1B-55K or E4orf3 proteins alter the distribution of PAR.

  20. Adenovirus type 5 E1A sensitizes hepatocellular carcinoma cells to gemcitabine.

    Science.gov (United States)

    Lee, Wei-Ping; Tai, Dar-In; Tsai, Sun-Lung; Yeh, Chau-Ting; Chao, Yee; Lee, Shou-Dong; Hung, Mien-Chie

    2003-10-01

    Hepatocellular carcinoma (HCC) is resistant to conventional chemotherapy. A few clinical trials have shown that the cytidine analogue gemcitabine appears to have antitumor activity for HCC, but the overall survival times remain to be improved. In this study, we examined the synergistic effect of adenovirus type 5 E1A (E1A) and gemcitabine on HCC and found that E1A sensitized J5, J7, Huh7, and HepG2 HCC cells to gemcitabine. To further study the E1A-mediated chemosensitization, we established stable cell lines that expressed the E1A gene and then examined whether E1A could have proapoptotic activity while expressed in HCC cells. Our results clearly showed that E1A sensitized HCC cells to gemcitabine through induction of apoptosis. To study the underlying mechanism, we tested nuclear factor (NF)-kappaB activity and found that NF-kappaB was activated in HCC cells treated with gemcitabine but not in HCC cells that expressed E1A. Occurrence of apoptosis entails cleavage of poly (ADP-ribose) polymerase (PARP), a nuclear protein involved in DNA repair, genome stability, and maintenance of telomere length. Our study showed that gemcitabine enhanced PARP expression. However, E1A did not induce PARP cleavage but rather suppressed PARP expression at the transcriptional level. Further study showed that both NF-kappaB and PARP played protective roles in the prevention of E1A+gemcitabine-induced apoptosis. PMID:14559808

  1. PARP-1 expression of Ishikawa cells treated with different concentration of MPA%不同浓度MPA对Ishikawa细胞PARP-1表达的影响

    Institute of Scientific and Technical Information of China (English)

    赵成志; 毕芳芳; 王光伟; 杨清

    2014-01-01

    Objective:To study the effect of PARP-1 expression of Ishikawa cells treated with different concen-tration of MPA,discussed the role of PARP-1 in the development of endometrial cancer,and the mutual relations be-tween PARP-1 and progesterone. Methods:The expression of PARP-1 was detected by immunohistochemical tech-nique,and PARP-1 mRNA by real-time PCR. Results:Immunohistochemistry showed that PARP-1 protein ex-pression in Ishikawa cell nucleus,with the increase of the concentration of MPA PARP-1 expression showed a down-ward trend. RT-PCR detected MPA concentration -dependent inhibition of PARP -1mRNA expression. Conclu-sion:Medroxyprogesterone acetate can affect DNA repair protein PARP-1 expression,to some extent,inhibited the expression of PARP-1 showed a concentration dependent,and also suggest progesterone may directly or indirectly by inhibiting PARP-1 play a role in the treatment of endometrial cancer.%目的:研究不同浓度孕激素作用子宫内膜癌Ishikawa细胞后DNA损伤修复蛋白PARP-1的表达变化,探讨PARP-1在子宫内膜腺癌中的作用及PARP-1和孕激素相互关系。方法:免疫组化SP法和实时荧光定量PCR(Real-time PCR)法检测不同浓度的醋酸甲羟孕酮(Medroxyprogesterone acetate,MPA)干预Ish-ikawa细胞后PARP-1蛋白及PARP-1 mRNA表达的变化。结果:免疫组化显示PARP-1蛋白表达于Ish-ikawa细胞核,随着MPA浓度的增加PARP-1的表达呈下降趋势。RT-PCR检测到MPA呈浓度依赖性地抑制PARP-1 mRNA表达。结论:醋酸甲羟孕酮呈浓度依赖性地抑制PARP-1的表达,提示孕激素可能间接或直接通过抑制PARP-1而发挥治疗子宫内膜癌的作用。

  2. Poly(ADP-ribosepolymerase-1 modulates microglial responses to amyloid β

    Directory of Open Access Journals (Sweden)

    Kauppinen Tiina M

    2011-11-01

    Full Text Available Abstract Background Amyloid β (Aβ accumulates in Alzheimer's disease (AD brain. Microglial activation also occurs in AD, and this inflammatory response may contribute to disease progression. Microglial activation can be induced by Aβ, but the mechanisms by which this occurs have not been defined. The nuclear enzyme poly(ADP-ribose polymerase-1 (PARP-1 regulates microglial activation in response to several stimuli through its interactions with the transcription factor, NF-κB. The purpose of this study was to evaluate whether PARP-1 activation is involved in Aβ-induced microglial activation, and whether PARP-1 inhibition can modify microglial responses to Aβ. Methods hAPPJ20 mice, which accumulate Aβ with ageing, were crossed with PARP-1-/- mice to assess the effects of PARP-1 depletion on microglial activation, hippocampal synaptic integrity, and cognitive function. Aβ peptide was also injected into brain of wt and PARP-1-/- mice to directly determine the effects of PARP-1 on Aβ-induced microglial activation. The effect of PARP-1 on Aβ-induced microglial cytokine production and neurotoxicity was evaluated in primary microglia cultures and in microglia-neuron co-cultures, utilizing PARP-1-/- cells and a PARP-1 inhibitor. NF-κB activation was evaluated in microglia infected with a lentivirus reporter gene. Results The hAPPJ20 mice developed microglial activation, reduced hippocampal CA1 calbindin expression, and impaired novel object recognition by age 6 months. All of these features were attenuated in hAPPJ20/PARP-1-/- mice. Similarly, Aβ1-42 injected into mouse brain produced a robust microglial response in wild-type mice, and this was blocked in mice lacking PARP-1 expression or activity. Studies using microglial cultures showed that PARP-1 activity was required for Aβ-induced NF-κB activation, morphological transformation, NO release, TNFα release, and neurotoxicity. Conversely, PARP-1 inhibition increased release of the

  3. The PARP promoter of Trypanosoma brucei is developmentally regulated in a chromosomal context

    DEFF Research Database (Denmark)

    Biebinger, S; Rettenmaier, S; Flaspohler, J; Hartmann, C; Pena Diaz, Javier; Wirtz, L E; Hotz, H R; Barry, J D; Clayton, C

    1996-01-01

    African trypanosomes are extracellular protozoan parasites that are transmitted from one mammalian host to the next by tsetse flies. Bloodstream forms express variant surface glycoprotein (VSG); the tsetse fly (procyclic) forms express instead the procyclic acidic repetitive protein (PARP). PARP ...

  4. Hypomethylation of ETS Transcription Factor Binding Sites and Upregulation of PARP1 Expression in Endometrial Cancer

    OpenAIRE

    Fang-Fang Bi; Da Li; Qing Yang

    2013-01-01

    Although PARP1 promoter methylation is involved in the regulation of PARP1 expression in human keratinocyte lines and lymphoblastoid cell lines, its roles in human endometrial cancer are unknown. DNA from forty normal endometrium (NE) and fifty endometrial adenocarcinoma (EAC) tissues were analyzed by bisulfite sequencing using primers focusing on the core promoter region of PARP1. Expression levels of PARP1 were assessed by immunohistochemistry and real-time PCR. Associations between patient...

  5. Radiosensitivity and Induction of Apoptosis by High LET Carbon Ion Beam and Low LET Gamma Radiation: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Atanu Ghorai

    2014-01-01

    Full Text Available Cancer treatment with high LET heavy ion beam, especially, carbon ion beam (12C, is becoming very popular over conventional radiotherapy like low LET gamma or X-ray. Combination of Poly(ADP-ribose polymerase (PARP inhibitor with xenotoxic drugs or conventional radiation (gamma or X-ray is the newer approach for cancer therapy. The aim of our study was to compare the radiosensitivity and induction of apoptosis by high LET 12C and low LET gamma radiation in HeLa and PARP-1 knocked down cells. We did comet assay to detect DNA breaks, clonogenic survival assay, and cell cycle analysis to measure recovery after DNA damage. We measured apoptotic parameters like nuclear fragmentation and caspase-3 activation. DNA damage, cell killing, and induction of apoptosis were significantly higher for 12C than gamma radiation in HeLa. Cell killing and apoptosis were further elevated upon knocking down of PARP-1. Both 12C and gamma induced G2/M arrest although the 12C had greater effect. Unlike the gamma, 12C irradiation affects DNA replication as detected by S-phase delay in cell cycle analysis. So, we conclude that high LET 12C has greater potential over low LET gamma radiation in killing cells and radiosensitization upon PARP-1 inhibition was several folds greater for 12C than gamma.

  6. Ataxia-telangiectasia cells are not uniformly deficient in poly(ADP-ribose) synthesis following X-irradiation

    International Nuclear Information System (INIS)

    The synthesis of poly(adenosine diphosphoribose [poly(ADP-R)] follows the DNA strand breakage produced by a number of physical and chemical agents, including X-radiation, and may be important for repair of several types of DNA damage. The reduction or abolition of its synthesis following X-irradiation might explain the enhanced sensitivity of ataxia-telangiectasia (A-T) cells to X-ray. We have examined 8 lines of human fibroblasts (including 4 A-T lines) for stimulation of the synthesis of poly(ADP-R) by X-irradiation. Similar amounts of X-ray-stimulated synthesis of poly(ADP-R) were detected in 4 lines of A-T fibroblasts, and in fibrolasts from a xeroderma pigmentosum (XP) patient, a Fanconi's anemia (FA) patient and 2 normal patients. 6 lines of human lymphoblastoid lines were also examined for X-ray-stimulated poly(ADP-R) synthesis. 4 A-T lines displayed an unusually high synthesis of poly(ADP-R) in unirradiated cells compared with 2 normal lines. (orig./AJ)

  7. Parp2 is required for the differentiation of post-meiotic germ cells: Identification of a spermatid-specific complex containing Parp1, Parp2, TP2 and HSPA2

    Energy Technology Data Exchange (ETDEWEB)

    Quenet, Delphine [IREBS-FRE 3211, Ecole Superieure de Biotechnologie de Strasbourg, F-67412 Illkirch cedex (France); Mark, Manuel [Institut de Genetique et de Biologie Moleculaire et Cellulaire (IGBMC), Institut Clinique de la souris (ICS), F-67404 Illkirch cedex (France); Govin, Jerome [INSERM, U823, Grenoble, F-38706 (France); Universite Joseph Fourier, Institut Albert Bonniot, Grenoble, F-38706 (France); Dorsselear, A. van [Laboratoire de Spectrometrie de Masse Bio-organique, UMR7178, Ecole de Chimie, Polymeres et Materiaux, Strasbourg (France); Schreiber, Valerie [IREBS-FRE 3211, Ecole Superieure de Biotechnologie de Strasbourg, F-67412 Illkirch cedex (France); Khochbin, Saadi [INSERM, U823, Grenoble, F-38706 (France); Universite Joseph Fourier, Institut Albert Bonniot, Grenoble, F-38706 (France); Dantzer, Francoise, E-mail: francoise.dantzer@unistra.fr [IREBS-FRE 3211, Ecole Superieure de Biotechnologie de Strasbourg, F-67412 Illkirch cedex (France)

    2009-10-01

    Spermiogenesis is a complex male germ cell post-meiotic differentiation process characterized by dramatic changes in chromatin structure and function, including chromatin condensation, transcriptional inhibition and the sequential replacement of histones by transition proteins and protamines. Recent advances, in mammalian cells, suggest a possible role of poly(ADP-ribosyl)ation catalyzed by Parp1 and/or Parp2 in this process. We have recently reported severely compromised spermiogenesis in Parp2-deficient mice characterized by a marked delay in nuclear elongation whose molecular mechanisms remain however unknown. Here, using in vitro protein-protein interaction assays, we show that Parp2 interacts significantly with both the transition protein TP2 and the transition chaperone HSPA2, whereas Parp1 binds weakly to HSPA2. Parp2-TP2 interaction is partly mediated by poly(ADP-ribosyl)ation. Only Parp1 poly(ADP-ribosyl)ates HSPA2. In addition, a detailed analysis of spermatid maturation in Parp2-deficient mice, combining immunohistochemistry and electron microscopic approaches, reveals a loss of spermatids expressing TP2, a defect in chromatin condensation and abnormal formation of the manchette microtubules that, together, contribute to spermatid-specific cell death. In conclusion, we propose both Parps as new participants of a spermatid-specific protein complex involved in genome reorganization throughout spermiogenesis.

  8. Parp2 is required for the differentiation of post-meiotic germ cells: Identification of a spermatid-specific complex containing Parp1, Parp2, TP2 and HSPA2

    International Nuclear Information System (INIS)

    Spermiogenesis is a complex male germ cell post-meiotic differentiation process characterized by dramatic changes in chromatin structure and function, including chromatin condensation, transcriptional inhibition and the sequential replacement of histones by transition proteins and protamines. Recent advances, in mammalian cells, suggest a possible role of poly(ADP-ribosyl)ation catalyzed by Parp1 and/or Parp2 in this process. We have recently reported severely compromised spermiogenesis in Parp2-deficient mice characterized by a marked delay in nuclear elongation whose molecular mechanisms remain however unknown. Here, using in vitro protein-protein interaction assays, we show that Parp2 interacts significantly with both the transition protein TP2 and the transition chaperone HSPA2, whereas Parp1 binds weakly to HSPA2. Parp2-TP2 interaction is partly mediated by poly(ADP-ribosyl)ation. Only Parp1 poly(ADP-ribosyl)ates HSPA2. In addition, a detailed analysis of spermatid maturation in Parp2-deficient mice, combining immunohistochemistry and electron microscopic approaches, reveals a loss of spermatids expressing TP2, a defect in chromatin condensation and abnormal formation of the manchette microtubules that, together, contribute to spermatid-specific cell death. In conclusion, we propose both Parps as new participants of a spermatid-specific protein complex involved in genome reorganization throughout spermiogenesis.

  9. Assessment of calpain and caspase systems activities during ageing of two bovine muscles by degradation patterns of αII spectrin and PARP-1.

    Science.gov (United States)

    Saccà, Elena; Pizzutti, Nicoletta; Corazzin, Mirco; Lippe, Giovanna; Piasentier, Edi

    2016-03-01

    The activities of calpain and caspase systems during ageing in Longissimus lumborum (LL) and Infraspinatus (IS) muscles of Italian Simmental young bulls (Bos taurus) were assessed. Samples from 10 animals were collected within 20 min of exsanguination (T0), after 48 h (T1) and 7 days (T2) post mortem. Calpain and caspase activity were evaluated based on the formation of αII spectrin cleavage products of 145 kDa (SBDP145) and 120 kDa (SBDP120), respectively. Caspase activity was also assessed by the presence of poly (adenosine diphosphate-ribose) polymerase-1 (PARP-1) cleavage product. At T0, LL showed higher levels of SBDP145 than IS (P spectrin nor PARP-1 cleavage products were found. LL and IS showed different proteolysis after slaughter that was influenced more by calpain than caspase activity, which was detectable only in the early post mortem period. PMID:26950517

  10. Curcumin induces apoptosis through the mitochondria-mediated apoptotic pathway in HT-29 cells

    Institute of Scientific and Technical Information of China (English)

    Jin-bo WANG; Li-li QI; Shui-di ZHENG; Tian-xing WU

    2009-01-01

    Objective:To investigate the effects of curcumin on release of cytochrome c and expressions of Bcl-2,Bax,Bad,Bcl-xL,caspase-3,poly ADP-ribose polymerase (PARP),and survivin of HT-29 cells.Methods:HT-29 cells were treated with curcumin (0~80 μmol/L) for 24 h.The release of cytochrome c from the mitochondria and the apoptosis-related proteins Bax,Bcl-2,Bci-xL,Bad,caspase-3,PARP,and survivin were determined by Western blot analysis and their mRNA expressions by reverse transcriptase-polymerase chain reaction (RT-PCR).Results:Curcumin significantly induced the growth inhibition and apoptosis of HT-29 ceils.A decrease in expressions of Bcl-2,Bci-xL and survivin was observed after exposure to 10~80 μmol/L curcumin,while the levels of Bax and Bad increased in the curcumin-treated cells.Curcumin also induced the release of cytochrome c,the activation ofcaspase-3,and the cleavage of PARP in a dose-dependent manner.Conclusion:These data suggest that curcumin induced the HT-29 cell apoptosis possibly via the mitochondria-mediated pathway.

  11. Cytological and molecular studies of chromosomal radiosensitivity in Down Syndrome cells

    International Nuclear Information System (INIS)

    Molecular, cellular and cytogenetic studies were conducted to determine if altered levels of poly(ADP-ribose) polymerase, a DNA repair-related enzyme, is responsible for the reported formation of excess X-ray induced chromosome aberrations in cells derived from Down Syndrome (DS) patients. Nonstimulated lymphocytes from normal and DS subjects were pretreated with 3-aminobenzamide, an inhibitor of poly(ADP-ribose) polymerase, for 30 minutes before exposure to X-rays and the levels of induced chromosome aberrations were determined in mitotic cells. DS lymphocytes exhibited significantly higher frequencies of chromosome aberrations in the presence of 3-aminobenzamide that normal lymphocytes. No difference was observed in the absence of 3-aminobenzamide. Additional studies were done using normal and DS lymphoblastoid cell lines which exhibited a similar response at the DNA level as the lymphocytes. Analysis of poly(ADP-ribose) polymerase activity based on incorporation of the substrate, NAD+, into acid insoluble materials, revealed that there was no significant difference in the ability to form poly (ADP-ribose) in the DS or normal cells. 3-aminobenzamide effectively inhibited poly(ADP-ribose) polymerase in both the normal and DS cells

  12. PARP-1 Regulates Chromatin Structure and Transcription Through a KDM5B-Dependent Pathway

    OpenAIRE

    Krishnakumar, Raga; Kraus, W. Lee

    2010-01-01

    PARP-1 is an abundant nuclear enzyme that regulates gene expression, although the underlying mechanisms are unclear. We examined the interplay between PARP-1, histone 3 lysine 4 trimethylation (H3K4me3), and linker histone H1 in the chromatin-dependent control of transcription. We show that PARP-1 is required for a series of molecular outcomes at the promoters of PARP-1 regulated genes, leading to a permissive chromatin environment that allows loading of the RNA Pol II machinery. PARP-1 does ...

  13. Hypomethylation of ETS Transcription Factor Binding Sites and Upregulation of PARP1 Expression in Endometrial Cancer

    Directory of Open Access Journals (Sweden)

    Fang-Fang Bi

    2013-01-01

    Full Text Available Although PARP1 promoter methylation is involved in the regulation of PARP1 expression in human keratinocyte lines and lymphoblastoid cell lines, its roles in human endometrial cancer are unknown. DNA from forty normal endometrium (NE and fifty endometrial adenocarcinoma (EAC tissues were analyzed by bisulfite sequencing using primers focusing on the core promoter region of PARP1. Expression levels of PARP1 were assessed by immunohistochemistry and real-time PCR. Associations between patient clinicopathological characteristics and PARP1 protein levels were assessed by Fisher’s exact test. Here, PARP1 mRNA and protein were overexpressed in EAC tissues (P<0.05. CpG sites within the ETS motif in the PARP1 promoter exhibited significant hypomethylation in EAC tissues, and there was a significant negative correlation between PARP1 mRNA levels and the number of methylated sites in both NE and EAC tissues (R2=0.262, P<0.001. Notably, PARP1 protein expression was associated with FIGO stage (P=0.026, histological grade (P=0.002 , and body mass index (P=0.04. Our findings imply that PARP1 overexpression may participate in endometrial cancer progression, and abnormal hypomethylation of CpG sites within the ETS motif in the core promoter region may be responsible for PARP1 overexpression in EAC tissues.

  14. Pelargonium quercetorum Agnew induces apoptosis without PARP or cytokeratin 18 cleavage in non-small cell lung cancer cell lines

    Science.gov (United States)

    Aztopal, Nazlihan; Cevatemre, Buse; Sarimahmut, Mehmet; Ari, Ferda; Dere, Egemen; Ozel, Mustafa Zafer; Firat, Mehmet; Ulukaya, Engin

    2016-01-01

    Pelargonium species have various uses in folk medicine as traditional remedies, and several of them have been screened for their biological activity, including anticancer. Pelargonium quercetorum Agnew (P. quercetorum) is traditionally used for its anthelminthic activity. However, little is known about its biological activity or its effect on cancer cells. The aim of the present study was to determine the cytotoxic activity of P. quercetorum extract on lung cancer cell lines with varying properties. Following the analyses of its chemical composition, the cytotoxic activity was screened by the adenosine triphosphate viability test. M30-Apoptosense® and M65 EpiDeath® enzyme-linked immunosorbent assays were used to determine the cell death mode (apoptosis vs. necrosis). For apoptosis, additional methods, including Annexin-V-fluorescein isothiocyanate (FITC) and Hoechst 33342 staining, were employed. The cleavage of poly (adenosine diphosphate-ribose) polymerase (PARP) was assayed by western blotting to further dissect the apoptosis mechanism. The methanol extract of P. quercetorum caused cytotoxic activity in a dose-dependent manner. The mode of cell death was apoptosis, as evidenced by the positive staining of the cells for Annexin-V-FITC and the presence of pyknotic nuclei. Notably, neither PARP cleavage nor cytokeratin 18 fragmentation were observed. P.quercetorum caused cell death by an apoptosis mechanism that is slightly different from classical apoptosis. Therefore, future in vivo experiments are required for further understanding of the effect of this plant on cancer cells.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Miltefosine induces metacaspase and PARP genes expression in Leishmania infantum

    Directory of Open Access Journals (Sweden)

    Shahram Khademvatan

    2011-10-01

    Full Text Available OBJECTIVES: Apoptosis is the process of programmed cell death (PCD that occurs in both animal and plant cells. Protozoan parasites possess metacaspase and these caspase-related proteases could be involved in the PCD pathways in these organisms. Therefore we analyzed the activities of metacaspase and PARP genes in Leishmania infantum (MCAN/IR/96/LON49 treated with miltefosine. MATERIALS AND METHODS: Anti-leishmania activity of miltefosine was studied by treatment of cultured promastigotes with various concentration of miltefosine. MTT assay and Annexin-V FLUOS staining by using FACS flow cytometry methods were used. Cytotoxic potential of HePC on the amastigots of L.infantum was evaluated in J774 cell line. In addition, metacaspase and PARP genes expression of treated L. infantum were studied. RESULTS: Miltefosine led to dose-dependent death of L. infantumwith features compatible with apoptosis. Over expression of metacaspase and PARP was seen 6 hr after treatment. CONCLUSIONS: Our study showed that miltefosine exerts cytotoxic effect on L. infantum via an apoptotic-related mechanism.

  17. Lifestyle influences human sperm functional quality

    Institute of Scientific and Technical Information of China (English)

    Mnica Ferreira; Joana Vieira Silva; Vladimiro Silva; Antnio Barros; Margarida Fardilha

    2012-01-01

    Objective:To investigate the impact of acute lifestyle changes on human sperm functional quality.Methods:In the academic festivities week, young and apparently healthy male students who voluntarily submit themselves to acute lifestyle alterations(among the potentially important variations are increase in alcohol, caffeine, and tobacco consumption and circadian rhythm shifts) were used as a model system.Sperm samples were obtained before and after the academic week and compared by traditional semen analysis(n=54) and also tested for cleavedPolyADP-ribose polymerase(PARP) protein, an apoptotic marker(n=35).Results:Acute lifestyle changes that occurred during the academic week festivities(the study model) resulted both in a significant reduction in sperm quality, assessed by basic semen analysis(decrease in sperm concentration, total number of spermatozoa, progressive and non-progressive motility and increase in sperm morphological abnormalities) and by an increase in the expression of the apoptotic marker, cleavedPARP, in the ejaculate.Conclusions:Acute lifestyle changes have clear deleterious effects on sperm quality.We propose cleavedPARP as a novel molecular marker, valuable for assessing spermquality in parallel with the basic semen analysis method.

  18. In silico characterization of the family of PARP-like poly(ADP-ribosyltransferases (pARTs

    Directory of Open Access Journals (Sweden)

    Dittmar Katharina

    2005-10-01

    Full Text Available Abstract Background ADP-ribosylation is an enzyme-catalyzed posttranslational protein modification in which mono(ADP-ribosyltransferases (mARTs and poly(ADP-ribosyltransferases (pARTs transfer the ADP-ribose moiety from NAD onto specific amino acid side chains and/or ADP-ribose units on target proteins. Results Using a combination of database search tools we identified the genes encoding recognizable pART domains in the public genome databases. In humans, the pART family encompasses 17 members. For 16 of these genes, an orthologue exists also in the mouse, rat, and pufferfish. Based on the degree of amino acid sequence similarity in the catalytic domain, conserved intron positions, and fused protein domains, pARTs can be divided into five major subgroups. All six members of groups 1 and 2 contain the H-Y-E trias of amino acid residues found also in the active sites of Diphtheria toxin and Pseudomonas exotoxin A, while the eleven members of groups 3 – 5 carry variations of this motif. The pART catalytic domain is found associated in Lego-like fashion with a variety of domains, including nucleic acid-binding, protein-protein interaction, and ubiquitylation domains. Some of these domain associations appear to be very ancient since they are observed also in insects, fungi, amoebae, and plants. The recently completed genome of the pufferfish T. nigroviridis contains recognizable orthologues for all pARTs except for pART7. The nearly completed albeit still fragmentary chicken genome contains recognizable orthologues for twelve pARTs. Simpler eucaryotes generally contain fewer pARTs: two in the fly D. melanogaster, three each in the mosquito A. gambiae, the nematode C. elegans, and the ascomycete microfungus G. zeae, six in the amoeba E. histolytica, nine in the slime mold D. discoideum, and ten in the cress plant A. thaliana. GenBank contains two pART homologues from the large double stranded DNA viruses Chilo iridescent virus and Bacteriophage Aeh1

  19. PARP3 is a sensor of nicked nucleosomes and monoribosylates histone H2BGlu2

    Science.gov (United States)

    Grundy, Gabrielle J.; Polo, Luis M.; Zeng, Zhihong; Rulten, Stuart L.; Hoch, Nicolas C.; Paomephan, Pathompong; Xu, Yingqi; Sweet, Steve M.; Thorne, Alan W.; Oliver, Antony W.; Matthews, Steve J.; Pearl, Laurence H.; Caldecott, Keith W.

    2016-01-01

    PARP3 is a member of the ADP-ribosyl transferase superfamily that we show accelerates the repair of chromosomal DNA single-strand breaks in avian DT40 cells. Two-dimensional nuclear magnetic resonance experiments reveal that PARP3 employs a conserved DNA-binding interface to detect and stably bind DNA breaks and to accumulate at sites of chromosome damage. PARP3 preferentially binds to and is activated by mononucleosomes containing nicked DNA and which target PARP3 trans-ribosylation activity to a single-histone substrate. Although nicks in naked DNA stimulate PARP3 autoribosylation, nicks in mononucleosomes promote the trans-ribosylation of histone H2B specifically at Glu2. These data identify PARP3 as a molecular sensor of nicked nucleosomes and demonstrate, for the first time, the ribosylation of chromatin at a site-specific DNA single-strand break. PMID:27530147

  20. Dicty_cDB: CHQ634 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available d pieces. 40 0.44 5 AC014505 |AC014505.1 Drosophila melanogaster, WORKING DRAFT SEQUENCE, in ordered piec...nts: (bits) Value (Q9ZP54) RecName: Full=Poly [ADP-ribose] polymerase 1; ... 75 2e-12 (Q7EYV7) RecName...l=Poly [ADP-ribose] polymerase; Sh... 65 2e-09 protein update 2009. 4.12 PSORT psg: 0.58 gvh: 0.23 alm: 0.54...EYQC KGWISGFTKCDWKGDSIERWAVQFPDDLSKNKFLSTFKYSK--- Frame B: akekwqqkihllmrlnmqrvidqhvqpvkevlikkqfvlvikqnqntlme...nf*ifkr--- Homology vs CSM-cDNA Score E Sequences producing significant alignments: (bits) Value CHQ634 (CHQ

  1. PARP-1 inhibition as a targeted strategy to treat Ewing's sarcoma

    OpenAIRE

    Brenner, J. Chad; Feng, Felix Y.; Han, Sumin; Patel, Sonam; Goyal, Siddharth V.; Bou-Maroun, Laura M.; Liu, Meilan; Lonigro, Robert; Prensner, John R.; Tomlins, Scott A.; Chinnaiyan, Arul M.

    2012-01-01

    Ewing's sarcoma family tumors (ESFTs) are aggressive malignancies which frequently harbor characteristic EWS-FLI1 or EWS-ERG genomic fusions. Here we report that these fusion products interact with the DNA damage response protein and transcriptional co-regulator PARP-1. ESFT cells, primary tumor xenografts and tumor metastases were all highly sensitive to PARP1 inhibition. Addition of a PARP1 inhibitor to the second-line chemotherapeutic agent temozolamide resulted in complete responses of al...

  2. A PARP1-ERK2 synergism is required for the induction of LTP

    OpenAIRE

    Visochek, L.; Grigoryan, G.,; Kalal, A.; H. Milshtein-Parush; Gazit, N.; Slutsky, I.; Yeheskel, A.; Shainberg, A.; Castiel, A.; Seger, R.; M. F. Langelier; F. Dantzer; Pascal, J. M.; Segal, M; Cohen-Armon, M

    2016-01-01

    Unexpectedly, a post-translational modification of DNA-binding proteins, initiating the cell response to single-strand DNA damage, was also required for long-term memory acquisition in a variety of learning paradigms. Our findings disclose a molecular mechanism based on PARP1-Erk synergism, which may underlie this phenomenon. A stimulation induced PARP1 binding to phosphorylated Erk2 in the chromatin of cerebral neurons caused Erk-induced PARP1 activation, rendering transcription factors and ...

  3. PARP-1 Val762Ala Polymorphism Is Associated with Risk of Cervical Carcinoma

    OpenAIRE

    Ye, Feng; Cheng, Qi; Hu, Yuting; Jing ZHANG; Chen, Huaizeng

    2012-01-01

    PARP-1 is a nuclear enzyme that plays an important role in DNA repair, recombination, proliferation and the genome stability. The PARP-1 Val762Ala polymorphism has been associated with increased risk of developing cancers of the prostate, esophagus and lung. The aim of this study was to determine whether the PARP-1 Val762Ala polymorphism is associated with the risk of cervical carcinoma. MA-PCR was used to genotype the PARP-1 Val762Ala polymorphism in 539 women with cervical carcinoma, 480 wo...

  4. The determination of apoptosis rates on articular cartilages of ovariectomized rats with and without alendronate treatment.

    Science.gov (United States)

    Acar, Nuray; Balkarli, Huseyin; Soyuncu, Yetkin; Ozbey, Ozlem; Celik-Ozenci, Ciler; Korkusuz, Petek; Ustunel, Ismail

    2016-06-01

    Osteoporosis (OP) is a major health problem characterized by compromised bone strength. Osteoarthritis (OA) is a joint disease that progresses slowly and is characterized by breakdown of the cartilage matrix. Alendronate (ALN), a nitrogen-containing bisphosphonate (BIS), inhibits bone loss and increases bone mineralization, and has been used clinically for the treatment of OP. It is still controversial whether BIS is effective in inhibiting the progression of OA. Chondrocyte apoptosis has been described in both human and experimentally induced OA models. In our study we aimed to detect whether ALN could protect articular cartilage from degeneration and reduce apoptosis rates in experimentally OA induced rats. For this rats were ovariectomized (ovex), nine weeks after operation rats were injected 30 µg/kg/week ALN subcutaneously for six weeks. After six weeks articular cartilages were obtained. We did Safranin O staining and Mankin and Pritzker scorings to evaluate degeneration and investigated the expressions of p53, cleaved caspase 3, Poly ADP-ribose (PAR), Poly ADP-ribose polymerase 1 (PARP 1), and applied TUNEL technique to determine apoptotis rates. We found a significant decrease in glycosaminoglycan (GAG) amount and increased apoptosis which indicates damage on articular cartilages of ovex rats. GAG amount was higher and apoptosis rate was lower on articular cartilages of ALN treated ovex rats compared to the ovex group. In contrary to studies showing that early ALN treatment has a protective effect, our study shows late ALN treatment has a chondroprotective effect on articular cartilage since we treated rats nine weeks after ovariectomy. PMID:26631351

  5. An Entamoeba histolytica ADP-ribosyl transferase from the diphtheria toxin family modifies the bacterial elongation factor Tu.

    Science.gov (United States)

    Avila, Eva E; Rodriguez, Orlando I; Marquez, Jaqueline A; Berghuis, Albert M

    2016-06-01

    ADP-ribosyl transferases are enzymes involved in the post-translational modification of proteins; they participate in multiple physiological processes, pathogenesis and host-pathogen interactions. Several reports have characterized the functions of these enzymes in viruses, prokaryotes and higher eukaryotes, but few studies have reported ADP-ribosyl transferases in lower eukaryotes, such as parasites. The locus EHI_155600 from Entamoeba histolytica encodes a hypothetical protein that possesses a domain from the ADP-ribosylation superfamily; this protein belongs to the diphtheria toxin family according to a homology model using poly-ADP-ribosyl polymerase 12 (PARP12 or ARTD12) as a template. The recombinant protein expressed in Escherichia coli exhibited in vitro ADP-ribosylation activity that was dependent on the time and temperature. Unlabeled βNAD(+), but not ADP-ribose, competed in the enzymatic reaction using biotin-βNAD(+) as the ADP-ribose donor. The recombinant enzyme, denominated EhToxin-like, auto-ADP-ribosylated and modified an acceptor from E. coli that was identified by MS/MS as the elongation factor Tu (EF-Tu). To the best of our knowledge, this is the first report to identify an ADP-ribosyl transferase from the diphtheria toxin family in a protozoan parasite. The known toxins from this family (i.e., the diphtheria toxin, the Pseudomonas aeruginosa toxin Exo-A, and Cholix from Vibrio cholerae) modify eukaryotic elongation factor two (eEF-2), whereas the amoeba EhToxin-like modified EF-Tu, which is another elongation factor involved in protein synthesis in bacteria and mitochondria. PMID:27234208

  6. Progress in the treatment of ovarian cancer-lessons from homologous recombination deficiency-the first 10 years.

    Science.gov (United States)

    Kaye, S B

    2016-04-01

    For several years, a major obstacle in the systemic treatment of ovarian cancer has been the lack of a therapeutic strategy tailored to specific biomarkers present in the individual patient's tumour. However, considerable progress has been made recently through the development of drugs targeting cells deficient in the key mechanism of double-strand DNA repair, known as homologous recombination (HRD). These drugs, inhibitors of the enzyme poly (ADP) ribose polymerase (PARP), selectively kill HRD cells through a process known as tumour-selective synthetic lethality. Olaparib is the first such agent, now approved for the treatment of ovarian cancer associated with mutations in the BRCA 1/2 genes, since these are characterised by cells with HRD. Importantly, another group of patients with tumours bearing a similar repair deficiency but without BRCA mutations may also be susceptible to PARP inhibition and efforts to develop an HRD assay are therefore a priority so that these patients can be identified as PARPi candidates. In addition, combination strategies are an area of intense research; these include combinations with antiangiogenic agents and with inhibitors of the P13K/AKT pathway and others are likely to merit assessment since resistance to PARP inhibitors will certainly emerge as the next challenge. While olaparib is the first PARP inhibitor to receive approval for ovarian cancer treatment, others including rucaparib and niraparib are clearly effective in this disease and, within the next year or two, the results of ongoing randomised trials will clarify their respective roles. PARP inhibitors are generally well tolerated; regulatory approval at present supports their use as a maintenance therapy (in Europe) and as treatment for advanced recurrent disease (in the United States), but it is likely that these indications will extend as the results of ongoing trials become available. Ten years have elapsed between the first pre-clinical publications and the

  7. Synthetic lethality of cohesins with PARPs and replication fork mediators.

    Directory of Open Access Journals (Sweden)

    Jessica L McLellan

    Full Text Available Synthetic lethality has been proposed as a way to leverage the genetic differences found in tumor cells to affect their selective killing. Cohesins, which tether sister chromatids together until anaphase onset, are mutated in a variety of tumor types. The elucidation of synthetic lethal interactions with cohesin mutants therefore identifies potential therapeutic targets. We used a cross-species approach to identify robust negative genetic interactions with cohesin mutants. Utilizing essential and non-essential mutant synthetic genetic arrays in Saccharomyces cerevisiae, we screened genome-wide for genetic interactions with hypomorphic mutations in cohesin genes. A somatic cell proliferation assay in Caenorhabditis elegans demonstrated that the majority of interactions were conserved. Analysis of the interactions found that cohesin mutants require the function of genes that mediate replication fork progression. Conservation of these interactions between replication fork mediators and cohesin in both yeast and C. elegans prompted us to test whether other replication fork mediators not found in the yeast were required for viability in cohesin mutants. PARP1 has roles in the DNA damage response but also in the restart of stalled replication forks. We found that a hypomorphic allele of the C. elegans SMC1 orthologue, him-1(e879, genetically interacted with mutations in the orthologues of PAR metabolism genes resulting in a reduced brood size and somatic cell defects. We then demonstrated that this interaction is conserved in human cells by showing that PARP inhibitors reduce the viability of cultured human cells depleted for cohesin components. This work demonstrates that large-scale genetic interaction screening in yeast can identify clinically relevant genetic interactions and suggests that PARP inhibitors, which are currently undergoing clinical trials as a treatment of homologous recombination-deficient cancers, may be effective in treating

  8. φ29 DNA polymerase

    OpenAIRE

    Blanco, Luis; Bernad, Antonio; Salas, Margarita

    1996-01-01

    An improved method for determining the nucleotide base sequence of a DNA molecule employs a φ-29 type DNA polymerase modified to have reduced or no exonuclease activity. The method includes annealing the DNA molecule with a primer molecule able to hybridize to the DNA molecule; incubating the annealed mixture in a vessel containing four different deoxynucleoside triphosphates, a DNA polymerase, and one or more DNA synthesis terminating agents which terminate DNA synthesis at a specific nucleo...

  9. 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.

  10. A PARP1-ERK2 synergism is required for the induction of LTP

    Science.gov (United States)

    Visochek, L.; Grigoryan, G.; Kalal, A.; Milshtein-Parush, H.; Gazit, N.; Slutsky, I.; Yeheskel, A.; Shainberg, A.; Castiel, A.; Seger, R.; Langelier, M. F.; Dantzer, F.; Pascal, J. M.; Segal, M.; Cohen-Armon, M.

    2016-01-01

    Unexpectedly, a post-translational modification of DNA-binding proteins, initiating the cell response to single-strand DNA damage, was also required for long-term memory acquisition in a variety of learning paradigms. Our findings disclose a molecular mechanism based on PARP1-Erk synergism, which may underlie this phenomenon. A stimulation induced PARP1 binding to phosphorylated Erk2 in the chromatin of cerebral neurons caused Erk-induced PARP1 activation, rendering transcription factors and promoters of immediate early genes (IEG) accessible to PARP1-bound phosphorylated Erk2. Thus, Erk-induced PARP1 activation mediated IEG expression implicated in long-term memory. PARP1 inhibition, silencing, or genetic deletion abrogated stimulation-induced Erk-recruitment to IEG promoters, gene expression and LTP generation in hippocampal CA3-CA1-connections. Moreover, a predominant binding of PARP1 to single-strand DNA breaks, occluding its Erk binding sites, suppressed IEG expression and prevented the generation of LTP. These findings outline a PARP1-dependent mechanism required for LTP generation, which may be implicated in long-term memory acquisition and in its deterioration in senescence. PMID:27121568

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

    International Nuclear Information System (INIS)

    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

  12. A PARP1-ERK2 synergism is required for the induction of LTP.

    Science.gov (United States)

    Visochek, L; Grigoryan, G; Kalal, A; Milshtein-Parush, H; Gazit, N; Slutsky, I; Yeheskel, A; Shainberg, A; Castiel, A; Seger, R; Langelier, M F; Dantzer, F; Pascal, J M; Segal, M; Cohen-Armon, M

    2016-01-01

    Unexpectedly, a post-translational modification of DNA-binding proteins, initiating the cell response to single-strand DNA damage, was also required for long-term memory acquisition in a variety of learning paradigms. Our findings disclose a molecular mechanism based on PARP1-Erk synergism, which may underlie this phenomenon. A stimulation induced PARP1 binding to phosphorylated Erk2 in the chromatin of cerebral neurons caused Erk-induced PARP1 activation, rendering transcription factors and promoters of immediate early genes (IEG) accessible to PARP1-bound phosphorylated Erk2. Thus, Erk-induced PARP1 activation mediated IEG expression implicated in long-term memory. PARP1 inhibition, silencing, or genetic deletion abrogated stimulation-induced Erk-recruitment to IEG promoters, gene expression and LTP generation in hippocampal CA3-CA1-connections. Moreover, a predominant binding of PARP1 to single-strand DNA breaks, occluding its Erk binding sites, suppressed IEG expression and prevented the generation of LTP. These findings outline a PARP1-dependent mechanism required for LTP generation, which may be implicated in long-term memory acquisition and in its deterioration in senescence. PMID:27121568

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

    Directory of Open Access Journals (Sweden)

    Eddy S. Yang

    2013-07-01

    Full Text Available 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.

  14. PARP-1 Val762Ala polymorphism is associated with risk of cervical carcinoma.

    Directory of Open Access Journals (Sweden)

    Feng Ye

    Full Text Available PARP-1 is a nuclear enzyme that plays an important role in DNA repair, recombination, proliferation and the genome stability. The PARP-1 Val762Ala polymorphism has been associated with increased risk of developing cancers of the prostate, esophagus and lung. The aim of this study was to determine whether the PARP-1 Val762Ala polymorphism is associated with the risk of cervical carcinoma. MA-PCR was used to genotype the PARP-1 Val762Ala polymorphism in 539 women with cervical carcinoma, 480 women with CIN and 800 controls. The genotyping method was confirmed by the DNA sequencing analysis. The PARP-1 Val762Ala polymorphism was not associated with the risk of CIN. However, women carrying the PARP-1 Ala762Ala genotype were significantly susceptible to cervical carcinoma (OR: 2.70, 95% CI: 1.47-3.70, and the similar results were also found in squamous cell carcinoma (OR: 2.56, 95% CI: 1.47-3.70. In HPV positive population, the PARP-1 Ala762Ala genotype was also associated with increased risk of cervical carcinoma (OR: 5.56, 95% CI: 2.08-14.3. Our results indicate that the PARP-1 Ala762Ala genotype increases the risk of cervical carcinoma.

  15. MGMT Expression Predicts PARP-Mediated Resistance to Temozolomide.

    Science.gov (United States)

    Erice, Oihane; Smith, Michael P; White, Rachel; Goicoechea, Ibai; Barriuso, Jorge; Jones, Chris; Margison, Geoffrey P; Acosta, Juan C; Wellbrock, Claudia; Arozarena, Imanol

    2015-05-01

    Melanoma and other solid cancers are frequently resistant to chemotherapies based on DNA alkylating agents such as dacarbazine and temozolomide. As a consequence, clinical responses are generally poor. Such resistance is partly due to the ability of cancer cells to use a variety of DNA repair enzymes to maintain cell viability. Particularly, the expression of MGMT has been linked to temozolomide resistance, but cotargeting MGMT has proven difficult due to dose-limiting toxicities. Here, we show that the MGMT-mediated resistance of cancer cells is profoundly dependent on the DNA repair enzyme PARP. Both in vitro and in vivo, we observe that MGMT-positive cancer cells strongly respond to the combination of temozolomide and PARP inhibitors (PARPi), whereas MGMT-deficient cells do not. In melanoma cells, temozolomide induced an antiproliferative senescent response, which was greatly enhanced by PARPi in MGMT-positive cells. In summary, we provide compelling evidence to suggest that the stratification of patients with cancer upon the MGMT status would enhance the success of combination treatments using temozolomide and PARPi. PMID:25777962

  16. Dicty_cDB: CHO804 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available CKNFDILFNGI EYQCKGWISGFTKCDWKGDSIER--- Frame B: xlliakekwqqkihllmrlnmqrvidqhvqpvkevlikkqfvlvikqnqntlme...Q) /CSM/CH/CHH5-D/CHH590Q.Seq.d/ 1197 0.0 own update 2004. 5. 9 Homology vs DNA Score E Sequences producing significant alignme... sapiens clone RP11-657G2, WORKING DRAFT SEQUENCE, 15 unordered pieces. 50 0.053 ...dna update 2005. 9. 9 Homology vs Protein Score E Sequences producing significant alignments: (bits) Value (Q9ZP54) RecName...: Full=Poly [ADP-ribose] polymerase 1; ... 75 2e-12 ( P26446 ) RecName: Full=Poly [ADP-ribose] polymer

  17. Dicty_cDB: SHF580 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 66 1e-09 ( Q11208 ) RecName: Full=Poly [ADP-ribose] polymerase; Sh... 62 3e-08 protein update 2009. 4.18 PSO...rlnmqrvidqhvqpvkevlikkqfvlvikqnqntlmewmyhgi i*nvnvhkyhhlqi*ftgntfvgktnyqlkqlifhlksmiqnqhqrykerni*r... E Sequences producing significant alignments: (bits) Value (Q9ZP54) RecName: Full=Poly [ADP-ribose] polymer...Seq.d/ 1172 0.0 own update 2004.12.25 Homology vs DNA Score E Sequences producing significant alignme...s sp. 2410 lytA gene for N-acetylmuramoyl-L-alanine amidase, strain 2410. 50 0.083 1 AM113502 |AM113502.1 Stre

  18. Rapid Evolution of PARP Genes Suggests a Broad Role for ADP-Ribosylation in Host-Virus Conflicts

    Science.gov (United States)

    Daugherty, Matthew D.; Young, Janet M.; Kerns, Julie A.; Malik, Harmit S.

    2014-01-01

    Post-translational protein modifications such as phosphorylation and ubiquitinylation are common molecular targets of conflict between viruses and their hosts. However, the role of other post-translational modifications, such as ADP-ribosylation, in host-virus interactions is less well characterized. ADP-ribosylation is carried out by proteins encoded by the PARP (also called ARTD) gene family. The majority of the 17 human PARP genes are poorly characterized. However, one PARP protein, PARP13/ZAP, has broad antiviral activity and has evolved under positive (diversifying) selection in primates. Such evolution is typical of domains that are locked in antagonistic ‘arms races’ with viral factors. To identify additional PARP genes that may be involved in host-virus interactions, we performed evolutionary analyses on all primate PARP genes to search for signatures of rapid evolution. Contrary to expectations that most PARP genes are involved in ‘housekeeping’ functions, we found that nearly one-third of PARP genes are evolving under strong recurrent positive selection. We identified a >300 amino acid disordered region of PARP4, a component of cytoplasmic vault structures, to be rapidly evolving in several mammalian lineages, suggesting this region serves as an important host-pathogen specificity interface. We also found positive selection of PARP9, 14 and 15, the only three human genes that contain both PARP domains and macrodomains. Macrodomains uniquely recognize, and in some cases can reverse, protein mono-ADP-ribosylation, and we observed strong signatures of recurrent positive selection throughout the macro-PARP macrodomains. Furthermore, PARP14 and PARP15 have undergone repeated rounds of gene birth and loss during vertebrate evolution, consistent with recurrent gene innovation. Together with previous studies that implicated several PARPs in immunity, as well as those that demonstrated a role for virally encoded macrodomains in host immune evasion, our

  19. Perinatal asphyxia: CNS development and deficits with delayed onset

    Directory of Open Access Journals (Sweden)

    MarioHerrera-Marschitz

    2014-03-01

    Full Text Available Perinatal asphyxia constitutes a prototype of obstetric complications occurring when pulmonary oxygenation is delayed or interrupted. The primary insult relates to the duration of the period lacking oxygenation, leading to death if not re-established. Re-oxygenation leads to a secondary insult, related to a cascade of biochemical events required for restoring proper function. Perinatal asphyxia interferes with neonatal development, resulting in long-term deficits associated to mental and neurological diseases with delayed clinical onset, by mechanisms not yet clarified.In the experimental scenario, the effects observed long after perinatal asphyxia have been explained by over expression of sentinel proteins, such as poly(ADP-ribose polymerase-1 (PARP-1, competing for NAD+ during re-oxygenation, leading to the idea that sentinel protein inhibition constitutes a suitable therapeutic strategy. Asphyxia induces transcriptional activation of pro-inflammatory factors, in tandem with PARP-1 overactivation, and pharmacologically induced PARP-1 inhibition also down-regulates the expression of proinflammatory cytokines. Nicotinamide has been proposed as a suitable PARP-1 inhibitor. Its effect has been studied in an experimental model of global hypoxia in rats. In that model, the insult is induced by immersing rat foetuses into a water bath for various periods of time. Following asphyxia, the pups are delivered, treated, and nursed by surrogate dams, pending further experiments. Nicotinamide rapidly distributes into the brain following systemic administration, reaching steady state concentrations sufficient to inhibit PARP-1 activity for several hours, preventing several of the long-term consequences of perinatal asphyxia, supporting the idea that it constitutes a lead for exploring compounds with similar or better pharmacological profiles.

  20. A diphenyl diselenide-supplemented diet and swimming exercise promote neuroprotection, reduced cell apoptosis and glial cell activation in the hypothalamus of old rats.

    Science.gov (United States)

    Leite, Marlon R; Cechella, José L; Pinton, Simone; Nogueira, Cristina W; Zeni, Gilson

    2016-09-01

    Aging is a process characterized by deterioration of the homeostasis of various physiological systems; although being a process under influence of multiple factors, the mechanisms involved in aging are not well understood. Here we investigated the effect of a (PhSe)2-supplemented diet (1ppm, 4weeks) and swimming exercise (1% of body weight, 20min per day, 4weeks) on proteins related to glial cells activation, apoptosis and neuroprotection in the hypothalamus of old male Wistar rats (27month-old). Old rats had activation of astrocytes and microglia which was demonstrated by the increase in the levels of glial fibrillary acidic protein (GFAP) and ionized calcium-binding adaptor molecule 1 (Iba-1) in hypothalamus. A decrease of B-cell lymphoma 2 (Bcl-2) and procaspase-3 levels as well as an increase of the cleaved PARP/full length PARP ratio (poly (ADP-ribose) polymerase, PARP) and the pJNK/JNK ratio (c-Jun N-terminal kinase, JNK) were observed. The levels of mature brain-derived neurotrophic factor (mBDNF), the pAkt/Akt ratio (also known as protein kinase B) and NeuN (neuronal nuclei), a neuron marker, were decreased in the hypothalamus of old rats. Old rats that received a (PhSe)2-supplemented diet and performed swimming exercise had the hypothalamic levels of Iba-1 and GFAP decreased. The combined treatment also increased the levels of Bcl-2 and procaspase-3 and decreased the ratios of cleaved PARP/full length PARP and pJNK/JNK in old rats. The levels of mBDNF and NeuN, but not the pAkt/Akt ratio, were increased by combined treatment. In conclusion, a (PhSe)2-supplemented diet and swimming exercise promoted neuroprotection in the hypothalamus of old rats, reducing apoptosis and glial cell activation. PMID:27215802

  1. Comparing the therapeutic efficiency of aminoguanidine and 3-aminobenzamide in lung and intestine toxicity caused by nitrogen mustard in rats

    International Nuclear Information System (INIS)

    Nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS) and peroxynitrite are responsible for sulfur mustard (SM) induced toxicity. Since endogenous production of peroxynitrite is known to lead to poly(ADP-ribose) polymerase (PARP) activation and sometimes ultimately cell death, in this study, it was aimed to compare the therapeutic efficiencies of aminoguanidine (iNOS inhibitor) and 3 aminobenzamide (PARP inhibitor) in lung and intestine toxicity caused by nitrogen mustard in rats. A total of 40 male Sprague-Dawley rats were divided into 4 groups. Group 1 served as control and given 2 ml saline, three groups received single dose of mechlorethamine (MEC) (3.5 mg/kg subcutaneously) with the same time intervals. Group 2 received MEC only, group 3 received selective iNOS inhibitor aminoguanidine (AG) (100 mg/kg i.p.) and, group 4 received PARP inhibitor 3 aminobenzamide (3-AB) (20 mg/kg i.p.). MEC injection resulted in severe lung toxicity with strong interstitial and alveolar edema, hemorrhage, emphysematous changes, Mild inflammatory cell infiltration and septal thickening. MEC injection also caused mucosal thinning, mild inflammatory cell infiltration, ischemic changes and multifocal, superficial ulcerations (erosions) in small intestine. In AG group, interstitial and alveolar edema, hemorrhage slightly reduced in lung comparing to MEC group. Inflammatory cell infiltration was minimal, septal thickening was similar to MEC group at densely edematous and hemorrhagical areas. In 3 AB group, edematous and hemorrhagic areas were very small, inflammatory cell infiltration was minimal and there were no densly densely edematous and hemorrhagical areas in lung. The results were better than AB group. In intestine, results of AG group were better than MEC group but worse than 3 AB group. These results suggest that both iNOS and PARP inhibitors are effective but PARP inhibitors may be more promising for treatment of SM induced early lung and intestinal toxicity.(author)

  2. Combined olaparib and oxaliplatin inhibits tumor proliferation and induces G2/M arrest and γ-H2AX foci formation in colorectal cancer

    Directory of Open Access Journals (Sweden)

    Xu K

    2015-10-01

    Full Text Available Kaiwu Xu,1* Zhihui Chen,2* Yi Cui,1 Changjiang Qin,2 Yulong He,2 Xinming Song2 1Endoscopy Center, 2Gastrointestinal Surgery Center, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong Province, People’s Republic of China *These authors contributed equally to this work Background: Poly (ADP-ribose polymerase 1 (PARP1 has an important role in homologous recombination repair. The purpose of this study was to investigate the effect of PARP1 inhibitor on oxaliplatin treatment for colorectal cancer (CRC. Methods: A cell counting kit-8 assay was used to determine the sensitivity of CRC cells to olaparib and/or oxaliplatin. The gene and protein expressions of PARP1 and the gamma histone variant H2AX (γH2AX were measured by real-time quantitative polymerase chain reaction and western blotting, respectively. The γH2AX foci formation assay was used to investigate the influence of treatments on cells. Flow cytometry was used to examine the changes in cell cycle distribution. Finally, we investigated the combination of olaparib and oxaliplatin in the CRC tumor model. Results: Olaparib changed the expression of γH2AX and PARP1, and increased the sensitivity of CRC cells to oxaliplatin. The γH2AX foci assay showed that olaparib did not induce double-strand breaks (DSBs alone, but it enhanced the induction of DSBs by oxaliplatin. The flow cytometry results showed that cells exposed to combination treatment had more G2/M-phase cells than control. Additionally, tumor xenograft studies suggested that combined treatment inhibited the growth of CRC. Conclusion: CRC cells are sensitized to combined treatment with olaparib and oxaliplatin, and this could be a promising strategy for clinical chemotherapy in CRC. Keywords: olaparib, oxaliplatin, chemosensitization, colorectal cancer

  3. 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.

  4. Signaling pathways involved in apoptosis induced by novel angucycline antibiotic landomycin E in Jurkat T leukemia cells

    Directory of Open Access Journals (Sweden)

    Panchuk R. R.

    2011-04-01

    Full Text Available Aim. To study the molecular mechanisms of action of novel anticancer antibiotic landomycin E (LE. Methods. Annexin V/propidium iodide, DAPI (4',6-diamidino-2-phenylindole staining, Western-blot analysis. Results. LE applied in 2 µg/ml dose (IC50, induced reactive oxygen species (ROS-dependent splitting of poly [ADP-ribose] polymerase 1 (PARP-1 and DNA Fragmentation Factor 45 (DFF45 proteins involved in DNA reparation. This effect was observed 6 h after the start of treatment and it positively correlated with phosphatidyl serine externalization (early morphological marker of apoptosis. We suggest that cleavage of PARP-1 and DFF45 was mediated by active caspase-7 which is a key effector caspase in the LE-induced apoptosis in leukemia cells. We found that activation of initiator procaspase-10 (involved in receptor- mediated apoptosis was the earliest detected event in LE-induced apoptotic signaling pathways; however, this activation was shown to be ROS-independent. We also demonstrated that the induction of apoptosis by LE is accompanied by activation of apoptosis-inducing factor (AIF in mitochondria. Conclusions. Our data suggest that LE-induced cascade of apoptotic events is started by the initiator caspase-10 which leads to activation of the effector caspase-7 and AIF that is known to induce caspase-independent apoptosis involving ROS generation.

  5. Withaferin A induces apoptosis through the generation of thiol oxidation in human head and neck cancer cells.

    Science.gov (United States)

    Park, Jong Won; Min, Kyoung-Jin; Kim, Dong Eun; Kwon, Taeg Kyu

    2015-01-01

    Withaferin A is a steroidal lactone purified from the Indian medicinal plant, Withania somnifera. Withaferin A has been shown to inhibit the proliferation, metastasis, invasion and angiogenesis of cancer cells. In the present study, we investigated whether withaferin A induces apoptosis in the human head and neck cancer cells, AMC-HN4. Withaferin A markedly increased the sub-G1 cell population and the cleavage of poly(ADP-ribose) polymerase (PARP), which are markers of apoptosis. Pan-caspase inhibitor, z-VAD-fmk (z-VAD), markedly inhibited the withaferin A-induced apoptosis. However, the withaferin A-induced increase in the expression of COX-2 was not affected by treatment with z-VAD. Furthermore, withaferin A upregulated cyclooxygenase-2 (COX-2) expression. The COX-2 inhibitor, NS-398, reduced the withaferin A-induced production of prostaglandin E2. However, treatment with NS-398 did not affect the sub-G1 population and the cleavage of PARP. In addition, the withaferin A-induced apoptosis was independent of reactive oxygen species production. Thiol donors [N-acetylcysteine (NAC) and dithiothreitol (DTT)] reversed withaferin A-induced apoptosis. Therefore, our data suggest that withaferin A induces apoptosis through the mechanism of thiol oxidation in head and neck carcinoma cells. PMID:25351115

  6. Enediyne lidamycin induces apoptosis in human multiple myeloma cells through activation of p38 mitogen-activated protein kinase and c-Jun NH2-terminal kinase.

    Science.gov (United States)

    Zhen, Yong-Zhan; Lin, Ya-Jun; Shang, Bo-Yang; Zhen, Yong-Su

    2009-07-01

    In the present study, the effects of lidamycin (LDM), a member of the enediyne antibiotic family, on two human multiple myeloma (MM) cell lines, U266 and SKO-007, were evaluated. In MTS assay, LDM showed much more potent cytotoxicity than conventional anti-MM agents to both cell lines. The IC(50) values of LDM for the U266 and SKO-007 cells were 0.0575 +/- 0.0015 and 0.1585 +/- 0.0166 nM, respectively, much lower than those of adriamycin, dexamethasone, and vincristine. Mechanistically, LDM triggered MM cells apoptosis by increasing the levels of cleaved poly ADP-ribose polymerase (PARP) and caspase-3/7. In addition, activation of p38 mitogen-activated protein kinase (MAPK) and c-Jun NH2-terminal kinase (JNK) was a critical mediator in LDM-induced cell death. Inhibition of the expression of p38 MAPK and JNK by pharmacological inhibitors reversed the LDM-induced apoptosis through decreasing the level of cleaved PARP and caspase-3/7. Interestingly, phosphorylation of extracellular signal-related kinase was increased by LDM; conversely, MEK inhibitor synergistically enhanced LDM-induced cytotoxicity and apoptosis in MM cells. The results demonstrated that LDM suppresses MM cell growth through the activation of p38 MAPK and JNK, with the potential to be developed as a chemotherapeutic agent for MM. PMID:19468799

  7. Prevention of acute/severe hypoglycemia-induced neuron death by lactate administration.

    Science.gov (United States)

    Won, Seok Joon; Jang, Bong Geom; Yoo, Byung Hoon; Sohn, Min; Lee, Min Woo; Choi, Bo Young; Kim, Jin Hee; Song, Hong Ki; Suh, Sang Won

    2012-06-01

    Hypoglycemia-induced cerebral neuropathy can occur in patients with diabetes who attempt tight control of blood glucose and may lead to cognitive dysfunction. Accumulating evidence from animal models suggests that hypoglycemia-induced neuronal death is not a simple result of glucose deprivation, but is instead the end result of a multifactorial process. In particular, the excessive activation of poly (ADP-ribose) polymerase-1 (PARP-1) consumes cytosolic nicotinamide adenine dinucleotide (NAD(+)), resulting in energy failure. In this study, we investigate whether lactate administration in the absence of cytosolic NAD(+) affords neuroprotection against hypoglycemia-induced neuronal death. Intraperitoneal injection of sodium L-lactate corrected arterial blood pH and blood lactate concentration after hypoglycemia. Lactate administered without glucose was not sufficient to promote electroencephalogram recovery from an isoelectric state during hypoglycemia. However, supplementation of glucose with lactate reduced neuronal death by ∼80% in the hippocampus. Hypoglycemia-induced superoxide production and microglia activation was also substantially reduced by administration of lactate. Taken together, these results suggest an intriguing possibility: that increasing brain lactate following hypoglycemia offsets the decrease in NAD(+) due to overactivation of PARP-1 by acting as an alternative energy substrate that can effectively bypass glycolysis and be fed directly to the citric acid cycle to maintain cellular ATP levels. PMID:22453629

  8. Inhibition of Myeloid Cell Leukemia 1 and Activation of Caspases Are Critically Involved in Gallotannin-induced Apoptosis in Prostate Cancer Cells.

    Science.gov (United States)

    Park, Eunkyung; Kwon, Hee Young; Jung, Ji Hoon; Jung, Deok-Beom; Jeong, Arong; Cheon, Jinhong; Kim, Bonglee; Kim, Sung-Hoon

    2015-08-01

    Although gallotannin contained in several medicinal plants was known to have multi-biological activities, such as antioxidant, antiinflammatory, antimicrobial, immunomodulatory, and antitumor effects, the underlying apoptotic mechanism of gallotannin is not fully understood so far. Thus, in the present study, the apoptotic mechanism of gallotannin was elucidated in DU145, PC-3, and M2182 prostate cancer cells in association with myeloid cell leukemia 1 (Mcl-1) signaling. Gallotannin exerted dose-dependent cytotoxicity in DU145, PC-3, and M2182 prostate cancer cells. Also, gallotannin showed apoptotic morphological features and increased the number of terminal deoxynucleotidyl transferase dUTP nick end labeling positive cells and sub-G1 accumulation in three prostate cancer cell lines. Consistently, gallotannin cleaved poly (ADP-ribose) polymerase (PARP) and attenuated the expression of procaspases 9 and 3 in three prostate cancer cell lines. Furthermore, gallotannin attenuated the expression of survival genes such as Mcl-1, B-cell lymphoma 2, and B-cell lymphoma 2 extra large in three prostate cancer cell lines. Interestingly, overexpression of Mcl-1 reversed the ability of gallotannin to cleave PARP and increase sub-G1 population in three prostate cancer cell lines. Conversely, silencing of Mcl-1 enhanced apoptosis by gallotannin in three prostate cancer cell lines by FACSCalibur (Becton Dickinson, Franklin Lakes, NJ, USA). Taken together, our findings demonstrate that inhibition of Mcl-1 and activation of caspases are critically involved in gallotannin-induced apoptosis in prostate cancer cells. PMID:26014377

  9. Protective effect of whey protein hydrolysates on H₂O₂-induced PC12 cells oxidative stress via a mitochondria-mediated pathway.

    Science.gov (United States)

    Jin, Man-Man; Zhang, Li; Yu, Hui-Xin; Meng, Jun; Sun, Zhen; Lu, Rong-Rong

    2013-11-15

    Whey protein hydrolysates (WPHs) were prepared with pepsin and trypsin. A PC12 cell model was built to observe the protective effect of WPHs against H2O2-induced oxidative stress. The results indicated that WPHs reduced apoptosis by 14% and increased antioxidant enzyme activities. Flow cytometry was used to assess the accumulation of reactive oxygen species (ROS), Ca(2+) levels and the mitochondrial membrane potential (MMP). The results showed that WPHs suppressed ROS elevation and Ca(2+) levels and stabilised MMP by 16%. The anti-apoptosis/pro-apoptosis proteins Bcl-2/Bax and poly (ADP-ribose) polymerase (PARP) were investigated by Western-blot analysis, which indicated that WPHs increased the expression of Bcl-2 while inhibiting the expression of Bax and the degradation of PARP. WPHs also blocked Caspase-3 activation by 62%. The results demonstrate that WPHs can significantly protect PC12 cells against oxidative stress via a mitochondria-mediated pathway. These findings indicate the potential benefits of WPHs as valuable food antioxidative additives. PMID:23790857

  10. Caffeine-based gold(I) N-heterocyclic carbenes as possible anticancer agents: synthesis and biological properties.

    Science.gov (United States)

    Bertrand, Benoît; Stefan, Loic; Pirrotta, Marc; Monchaud, David; Bodio, Ewen; Richard, Philippe; Le Gendre, Pierre; Warmerdam, Elena; de Jager, Marina H; Groothuis, Geny M M; Picquet, Michel; Casini, Angela

    2014-02-17

    A new series of gold(I) N-heterocyclic carbene (NHC) complexes based on xanthine ligands have been synthesized and characterized by mass spectrometry, NMR, and X-ray diffraction. The compounds have been tested for their antiproliferative properties in human cancer cells and nontumorigenic cells in vitro, as well as for their toxicity in healthy tissues ex vivo. The bis-carbene complex [Au(caffein-2-ylidene)2][BF4] (complex 4) appeared to be selective for human ovarian cancer cell lines and poorly toxic in healthy organs. To gain preliminary insights into their actual mechanism of action, two biologically relevant in cellulo targets were studied, namely, DNA (more precisely a higher-order DNA structure termed G-quadruplex DNA that plays key roles in oncogenetic regulation) and a pivotal enzyme of the DNA damage response (DDR) machinery (poly-(adenosine diphosphate (ADP)-ribose) polymerase 1 (PARP-1), strongly involved in the cancer resistance mechanism). Our results indicate that complex 4 acts as an efficient and selective G-quadruplex ligand while being a modest PARP-1 inhibitor (i.e., poor DDR impairing agent) and thus provide preliminary insights into the molecular mechanism that underlies its antiproliferative behavior. PMID:24499428

  11. Editorial

    Directory of Open Access Journals (Sweden)

    Khong HT

    2011-04-01

    Full Text Available Hung T KhongUniversity of South Alabama, Mitchell Cancer institute, Mobile, AL, USAWith the completion of the human genome project and the explosion of knowledge derived from genomics, proteomics, metabolomics, and other-omics, there are a vast and ever increasing number of potential druggable targets and therapeutic candidates. Each of these targets can be considered a potential biomarker that serves as a risk assessment tool and/or a biological predictor of prognosis and treatment outcome. For example, the risk of developing breast cancer in a woman who has inherited a deleterious breast cancer antigen (BRCA1 mutation is five times that of a woman in the general population.1 When cells are damaged by chemotherapy, DNA damages are often repaired by the BRCA pathway. In cells that are deficient in BRCA functionality, an alternative pathway such as the base excision repair pathway is utilized. This pathway is dependent on poly (ADP-ribose polymerase (PARP being fully functional.2 Therefore, BRCA1-deficient cancer cells are exquisitely sensitive to the combination of PARP inhibitor and chemotherapy.3,4 In this case, BRCA1 serves as a biomarker for both risk of developing breast cancer and favorable outcome to certain treatments.

  12. Pyrimidinone nicotinamide mimetics as selective tankyrase and wnt pathway inhibitors suitable for in vivo pharmacology.

    Science.gov (United States)

    Johannes, Jeffrey W; Almeida, Lynsie; Barlaam, Bernard; Boriack-Sjodin, P Ann; Casella, Robert; Croft, Rosemary A; Dishington, Allan P; Gingipalli, Lakshmaiah; Gu, Chungang; Hawkins, Janet L; Holmes, Jane L; Howard, Tina; Huang, Jian; Ioannidis, Stephanos; Kazmirski, Steven; Lamb, Michelle L; McGuire, Thomas M; Moore, Jane E; Ogg, Derek; Patel, Anil; Pike, Kurt G; Pontz, Timothy; Robb, Graeme R; Su, Nancy; Wang, Haiyun; Wu, Xiaoyun; Zhang, Hai-Jun; Zhang, Yue; Zheng, Xiaolan; Wang, Tao

    2015-03-12

    The canonical Wnt pathway plays an important role in embryonic development, adult tissue homeostasis, and cancer. Germline mutations of several Wnt pathway components, such as Axin, APC, and ß-catenin, can lead to oncogenesis. Inhibition of the poly(ADP-ribose) polymerase (PARP) catalytic domain of the tankyrases (TNKS1 and TNKS2) is known to inhibit the Wnt pathway via increased stabilization of Axin. In order to explore the consequences of tankyrase and Wnt pathway inhibition in preclinical models of cancer and its impact on normal tissue, we sought a small molecule inhibitor of TNKS1/2 with suitable physicochemical properties and pharmacokinetics for hypothesis testing in vivo. Starting from a 2-phenyl quinazolinone hit (compound 1), we discovered the pyrrolopyrimidinone compound 25 (AZ6102), which is a potent TNKS1/2 inhibitor that has 100-fold selectivity against other PARP family enzymes and shows 5 nM Wnt pathway inhibition in DLD-1 cells. Moreover, compound 25 can be formulated well in a clinically relevant intravenous solution at 20 mg/mL, has demonstrated good pharmacokinetics in preclinical species, and shows low Caco2 efflux to avoid possible tumor resistance mechanisms. PMID:25815142

  13. Nitrosative stress mediated misfolded protein aggregation mitigated by Na-D-{beta}-hydroxybutyrate intervention

    Energy Technology Data Exchange (ETDEWEB)

    Kabiraj, Parijat; Pal, Rituraj [Department of Chemistry, University of Texas at El Paso, El Paso, TX (United States); Varela-Ramirez, Armando [Department of Biological Sciences, Border Biomedical Research Center, University of Texas at El Paso, El Paso, TX (United States); Miranda, Manuel [Department of Biological Sciences, University of Texas at El Paso, El Paso, TX (United States); Narayan, Mahesh, E-mail: mnarayan@utep.edu [Department of Chemistry, University of Texas at El Paso, El Paso, TX (United States)

    2012-09-28

    Highlights: Black-Right-Pointing-Pointer Rotenone is a model for inducing apoptosis and synphilin-1 accumulation in Parkinson Prime s studies. Black-Right-Pointing-Pointer The metabolite sodium betahydroxybutryate mitigates these effects in SHSY5Y cell lines. Black-Right-Pointing-Pointer Results reveal a novel and innate mechanism to prevent neurodegeneration/cell death. -- Abstract: Mitochondrial dysfunction, leading to elevated levels of reactive oxygen species, is associated with the pathogenesis of neurodegenerative disorders. Rotenone, a mitochondrial stressor induces caspase-9 and caspase-3 activation leading proteolytic cleavage of substrate nuclear poly(ADP-ribose) polymerase (PARP). PARP cleavage is directly related to apoptotic cell death. In this study, we have monitored the aggregation of green-fluorescent protein (GFP)-tagged synphilin-1, as a rotenone-induced Parkinsonia-onset biomarker. We report that the innate ketone body, Na-D-{beta}-hydroxybutyrate (Na{beta}HB) reduces markedly the incidence of synphilin-1 aggregation. Furthermore, our data reveal that the metabolic byproduct also prevents rotenone-induced caspase-activated apoptotic cell death in dopaminergic SH-SY5Y cells. Together, these results suggest that Na{beta}HB is neuroprotective; it attenuates effects originating from mitochondrial insult and can serve as a scaffold for the design and development of sporadic neuropathies.

  14. Crimean-Congo haemorrhagic fever replication interplays with regulation mechanisms of apoptosis.

    Science.gov (United States)

    Karlberg, Helen; Tan, Yee-Joo; Mirazimi, Ali

    2015-03-01

    Pathogenesis of viral haemorrhagic fevers is associated with alteration of vascular barrier function and haemorrhage. To date, the specific mechanism behind this is unknown. Programmed cell death and regulation of apoptosis in response to viral infection is an important factor for host or virus survival but this has not been well-studied in the case of Crimean-Congo hemorrhagic fever virus (CCHFV). In this study, we demonstrated that CCHFV infection suppresses cleavage of poly(ADP-ribose) polymerase (PARP), triggered by staurosporine early post-infection. We also demonstrated that CCHFV infection suppresses activation of caspase-3 and caspase-9. Most interestingly, we found that CCHFV N can suppress induction of apoptosis by Bax and inhibit the release of cytochrome c from the inner membrane of mitochondria to cytosol. However, CCHFV infection induces activation of Bid late post-infection, suggesting activation of extrinsic apoptotic signalling. Consistently, supernatant from cells stimulated late post-infection was found to induce PARP cleavage, most probably through the TNF-α death receptor pathway. In summary, we found that CCHFV has strategies to interplay with apoptosis pathways and thereby regulate caspase cascades. We suggest that CCHFV suppresses caspase activation at early stages of the CCHFV replication cycle, which perhaps benefits the establishment of infection. Furthermore, we suggest that the host cellular response at late stages post-infection induces host cellular pro-apoptotic molecules through the death receptor pathway. PMID:25481756

  15. Persistence and prevention of aluminium- and paraquat-induced adaptive response to methyl mercuric chloride in plant cells in vivo.

    Science.gov (United States)

    Patra, Jita; Sahoo, Malaya K; Panda, Brahma B

    2003-07-01

    Induction and persistence of adaptive response by aluminium (Al), 1 or 10 microM, and paraquat (PQ), 5 or 10 microM, against genotoxicity of methyl mercuric chloride (MMCl), 1.26 microM, a standard environmental genotoxin, was investigated in root meristem cells of Allium cepa. Subsequently, three metabolic inhibitors, namely, 3-aminobezamide (3-AB, 10 or 100 microM), an inhibitor of poly(ADP-ribose) polymerase (PARP) implicated in DNA repair and/or apoptosis, cycloheximide (CH, 0.1 or 1 microM), an inhibitor of protein synthesis, and buthionine sulfoximine (BSO, 100 microM or 1mM), an inhibitor of glutathione synthesis were tested for their ability to prevent the adaptive response induced by conditioning doses of Al, 10 or 100 microM; and PQ, 5 or 100 microM, against MMCl-challenge, 1.26 or 100 microM, in root meristems of A. cepa or embryonic shoots of Hordeum vulgare, respectively. The findings demonstrated that once triggered, the Al- or PQ-adaptive response to MMCl could persist for at least 48h in root meristems of A. cepa. Furthermore, the adaptive response could effectively be prevented by 3-AB, to a lesser degree by CH, and the least by BSO, suggesting primarily the involvement of PARP and implicating DNA repair in the underlying mechanisms of adaptive response in plant cells in vivo. PMID:12834754

  16. Sensitization by wortmannin of heat- or X-ray induced cell death in cultured Chinese hamster V79 cells

    International Nuclear Information System (INIS)

    Here we found that wortmannin sensitized Chinese hamster V79 cells to hyperthermic treatment at 44.0 deg C as determined either by colony formation assay or by dye exclusion assay. Wortmannin enhanced heat-induced cell death accompanying cleavage of poly (ADP-ribose) polymerases (PARP). Additionally, the induction of heat shock protein HSP70 was suppressed and delayed in wortmannin-treated cells. Heat sensitizing effect of wortmannin was obvious at more than 5 or 10 μM of final concentrations, while radiosensitization was apparent at 5 μM. Requirement for high concentration of wortmannin, i.e., order of μM, suggests a possible role of certain protein kinases, such as DNA-PK and/or ATM among PI3-kinase family. The sensitization was minimal when wortmannin was added at the end of heat treatment. This was similar to the case of X-ray. Since heat-induced cell death and PARP cleavage preceded HSP70 induction phenomenon, the sensitization to the hyperthermic treatment was considered mainly caused by enhanced apoptotic cell death rather than secondary to suppression or delay by wortmannin of HSP70 induction. Further, in the present system radiosensitization by wortmannin was also at least partly mediated through enhancement of apoptotic cell death. (author)

  17. DSePA Antagonizes High Glucose-Induced Neurotoxicity: Evidences for DNA Damage-Mediated p53 Phosphorylation and MAPKs and AKT Pathways.

    Science.gov (United States)

    Wang, Kun; Fu, Xiao-Yan; Fu, Xiao-Ting; Hou, Ya-Jun; Fang, Jie; Zhang, Shuai; Yang, Ming-Feng; Li, Da-Wei; Mao, Lei-Lei; Sun, Jing-Yi; Yuan, Hui; Yang, Xiao-Yi; Fan, Cun-Dong; Zhang, Zong-Yong; Sun, Bao-Liang

    2016-09-01

    Hyperglycemia as the major hallmark of diabetic neuropathy severely limited its therapeutic efficiency. Evidences have revealed that selenium (Se) as an essential trace element could effectively reduce the risk of neurological diseases. In the present study, 3,3'-diselenodipropionic acid (DSePA), a derivative of selenocystine, was employed to investigate its protective effect against high glucose-induced neurotoxicity in PC12 cells and evaluate the underlying mechanism. The results suggested that high glucose showed significant cytotoxicity through launching mitochondria-mediated apoptosis in PC12 cells, accompanied by poly (ADP-ribose) polymerase (PARP) cleavage, caspase activation, and mitochondrial dysfunction. Moreover, high glucose also triggered DNA damage and dysregulation of MAPKs and AKT pathways through reactive oxygen species (ROS) overproduction. p53 RNA interference partially suppressed high glucose-induced cytotoxicity and apoptosis, indicating the role of p53 in high glucose-induced signal. However, DSePA pretreatment effectively attenuated high glucose-induced cytotoxicity, inhibited the mitochondrial dysfunction through regulation of Bcl-2 family, and ultimately reversed high glucose-induced apoptotic cell death in PC12 cells. Attenuation of caspase activation, PARP cleavage, DNA damage, and ROS accumulation all confirmed its protective effects. Moreover, DSePA markedly alleviated the dysregulation of AKT and MAPKs pathways induced by high glucose. Our findings revealed that the strategy of using DSePA to antagonize high glucose-induced neurotoxicity may be a highly effective strategy in combating high glucose-mediated neurological diseases. PMID:26232068