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1.
Toxicol Appl Pharmacol ; 410: 115360, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33279515

RESUMO

People living in southwest part of United States are exposed to uranium (U) through drinking water, air, and soil. U is radioactive, but independent of this radioactivity also has important toxicological considerations as an environmental metal. At environmentally relevant concentrations, U is both mutagenic and carcinogenic. Emerging evidence shows that U inhibits DNA repair activity, but how U interacts with DNA repair proteins is still largely unknown. Herein, we report that U directly interacts with the DNA repair protein, Protein Poly (ADP-ribose) Polymerase 1 (PARP-1) through direct binding with the zinc finger motif, resulting in zinc release from zinc finger and DNA binding activity loss of the protein. At the peptide level, instead of direct competition with zinc ion in the zinc finger motif, U does not show thermodynamic advantages over zinc. Furthermore, zinc pre-occupied PARP-1 zinc finger is insensitive to U treatment, but U bound to PARP-1 zinc finger can be partially replaced by zinc. These results provide mechanistic basis on molecular level to U inhibition of DNA repair.


Assuntos
Reparo do DNA/fisiologia , Reparo do DNA/efeitos da radiação , Poli(ADP-Ribose) Polimerase-1/metabolismo , Poli(ADP-Ribose) Polimerase-1/efeitos da radiação , Urânio/metabolismo , Urânio/toxicidade , Sequência de Aminoácidos , Células Cultivadas , Exposição Ambiental/efeitos adversos , Humanos , Recém-Nascido , Queratinócitos/metabolismo , Queratinócitos/efeitos da radiação , Poli(ADP-Ribose) Polimerase-1/genética , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/fisiologia
2.
Mol Cell ; 80(5): 862-875.e6, 2020 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-33275888

RESUMO

The anti-tumor potency of poly(ADP-ribose) polymerase (PARP) inhibitors (PARPis) has been linked to trapping of PARP1 on damaged chromatin. However, little is known about their impact on PARP2, an isoform with overlapping functions at DNA lesions. Whether the release of PARP1/2 from DNA lesions is actively catalyzed by molecular machines is also not known. We found that PARPis robustly trap PARP2 and that the helicase ALC1 (CHD1L) is strictly required for PARP2 release. Catalytic inactivation of ALC1 quantitatively traps PARP2 but not PARP1. ALC1 manipulation impacts the response to single-strand DNA breaks through PARP2 trapping, potentiates PARPi-induced cancer cell killing, and mediates synthetic lethality upon BRCA deficiency. The chromatin remodeler ALC1 actively drives PARP2 turnover from DNA lesions, and PARP2 contributes to the cellular responses of PARPi. This suggests that disrupting the ATP-fueled remodeling forces of ALC1 might enable therapies that selectively target the DNA repair functions of PARPs in cancer.


Assuntos
Quebras de DNA de Cadeia Simples , DNA Helicases/metabolismo , Proteínas de Ligação a DNA/metabolismo , Neoplasias/enzimologia , Inibidores de Poli(ADP-Ribose) Polimerases/metabolismo , Poli(ADP-Ribose) Polimerases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Linhagem Celular Tumoral , DNA Helicases/genética , Proteínas de Ligação a DNA/genética , Humanos , Neoplasias/genética , Neoplasias/patologia , Poli(ADP-Ribose) Polimerase-1/genética , Poli(ADP-Ribose) Polimerase-1/metabolismo , Poli(ADP-Ribose) Polimerases/genética , Proteínas Proto-Oncogênicas/genética
3.
Nucleic Acids Res ; 48(21): 12234-12251, 2020 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-33211885

RESUMO

Altered oncogene expression in cancer cells causes loss of redox homeostasis resulting in oxidative DNA damage, e.g. 8-oxoguanine (8-oxoG), repaired by base excision repair (BER). PARP1 coordinates BER and relies on the upstream 8-oxoguanine-DNA glycosylase (OGG1) to recognise and excise 8-oxoG. Here we hypothesize that OGG1 may represent an attractive target to exploit reactive oxygen species (ROS) elevation in cancer. Although OGG1 depletion is well tolerated in non-transformed cells, we report here that OGG1 depletion obstructs A3 T-cell lymphoblastic acute leukemia growth in vitro and in vivo, validating OGG1 as a potential anti-cancer target. In line with this hypothesis, we show that OGG1 inhibitors (OGG1i) target a wide range of cancer cells, with a favourable therapeutic index compared to non-transformed cells. Mechanistically, OGG1i and shRNA depletion cause S-phase DNA damage, replication stress and proliferation arrest or cell death, representing a novel mechanistic approach to target cancer. This study adds OGG1 to the list of BER factors, e.g. PARP1, as potential targets for cancer treatment.


Assuntos
Neoplasias do Colo/tratamento farmacológico , DNA Glicosilases/genética , DNA de Neoplasias/genética , Regulação Neoplásica da Expressão Gênica , Poli(ADP-Ribose) Polimerase-1/imunologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Neoplasias do Colo/mortalidade , Dano ao DNA , DNA Glicosilases/antagonistas & inibidores , DNA Glicosilases/metabolismo , Reparo do DNA/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , DNA de Neoplasias/metabolismo , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Guanina/análogos & derivados , Guanina/metabolismo , Células HCT116 , Humanos , Camundongos , Camundongos Nus , Terapia de Alvo Molecular , Estresse Oxidativo , Poli(ADP-Ribose) Polimerase-1/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Análise de Sobrevida , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
4.
Sci Rep ; 10(1): 20210, 2020 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-33214574

RESUMO

The overall prognosis for pancreatic cancer remains dismal and potent chemotherapeutic agents that selectively target this cancer are critically needed. Elevated expression of NAD(P)H:quinone oxidoreductase 1 (NQO1) is frequent in pancreatic cancer, and it offers promising tumor-selective targeting. Recently, KP372-1 was identified as a novel NQO1 redox cycling agent that induces cytotoxicity in cancer cells by creating redox imbalance; however, the mechanistic basis of KP372-1-induced cytotoxicity remains elusive. Here, we show that KP372-1 sensitizes NQO1-expressing pancreatic cancer cells and spares immortalized normal pancreatic duct cells, hTERT-HPNE. Notably, we found that KP372-1 is ~ 10- to 20-fold more potent than ß-lapachone, another NQO1 substrate, against pancreatic cancer cells. Mechanistically, our data strongly suggest that reactive oxygen species produced by NQO1-dependent redox cycling of KP372-1 cause robust DNA damage, including DNA breaks. Furthermore, we found that KP372-1-induced DNA damage hyperactivates the central DNA damage sensor protein poly(ADP-ribose) polymerase 1 (PARP1) and activates caspase-3 to initiate cell death. Our data also show that the combination of KP372-1 with PARP inhibition creates enhanced cytotoxicity in pancreatic cancer cells. Collectively, our study provides mechanistic insights into the cytotoxicity instigated by KP372-1 and lays an essential foundation to establish it as a promising chemotherapeutic agent against cancer.


Assuntos
Antineoplásicos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Neoplasias Pancreáticas/tratamento farmacológico , Poli(ADP-Ribose) Polimerase-1/metabolismo , Tetrazóis/farmacologia , Antineoplásicos/uso terapêutico , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Compostos Heterocíclicos de 4 ou mais Anéis/uso terapêutico , Humanos , NAD(P)H Desidrogenase (Quinona)/metabolismo , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Espécies Reativas de Oxigênio/metabolismo , Tetrazóis/uso terapêutico
5.
Mol Cell ; 80(4): 560-561, 2020 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-33217315

RESUMO

Bilokapic at al. (2020) capture PARP2 and its accessory factor HPF1 bridging a DNA break between two nucleosomes, providing a captivating view of the context in which PARP2/HPF1 employ ADP-ribose protein modification to coordinate DNA repair and alter chromatin structure.


Assuntos
Cromatina , Poli Adenosina Difosfato Ribose , Cromatina/genética , Quebras de DNA , Reparo do DNA , Poli(ADP-Ribose) Polimerase-1/metabolismo
6.
Nucleic Acids Res ; 48(21): e122, 2020 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-33053171

RESUMO

Protein-protein interactions are essential to ensure timely and precise recruitment of chromatin remodellers and repair factors to DNA damage sites. Conventional analyses of protein-protein interactions at a population level may mask the complexity of interaction dynamics, highlighting the need for a method that enables quantification of DNA damage-dependent interactions at a single-cell level. To this end, we integrated a pulsed UV laser on a confocal fluorescence lifetime imaging (FLIM) microscope to induce localized DNA damage. To quantify protein-protein interactions in live cells, we measured Förster resonance energy transfer (FRET) between mEGFP- and mCherry-tagged proteins, based on the fluorescence lifetime reduction of the mEGFP donor protein. The UV-FLIM-FRET system offers a unique combination of real-time and single-cell quantification of DNA damage-dependent interactions, and can distinguish between direct protein-protein interactions, as opposed to those mediated by chromatin proximity. Using the UV-FLIM-FRET system, we show the dynamic changes in the interaction between poly(ADP-ribose) polymerase 1, amplified in liver cancer 1, X-ray repair cross-complementing protein 1 and tripartite motif containing 33 after DNA damage. This new set-up complements the toolset for studying DNA damage response by providing single-cell quantitative and dynamic information about protein-protein interactions at DNA damage sites.


Assuntos
Osteoblastos/efeitos da radiação , Poli(ADP-Ribose) Polimerase-1/genética , Mapeamento de Interação de Proteínas/métodos , Fatores de Transcrição/genética , Proteína 1 Complementadora Cruzada de Reparo de Raio-X/genética , Linhagem Celular Tumoral , Cromatina/química , Cromatina/metabolismo , Cromatina/efeitos da radiação , Dano ao DNA , Transferência Ressonante de Energia de Fluorescência , Regulação da Expressão Gênica , Genes Reporter , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Lasers , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Imagem Óptica , Osteoblastos/citologia , Osteoblastos/metabolismo , Poli(ADP-Ribose) Polimerase-1/metabolismo , Ligação Proteica , Transdução de Sinais , Análise de Célula Única , Fatores de Transcrição/metabolismo , Raios Ultravioleta , Proteína 1 Complementadora Cruzada de Reparo de Raio-X/metabolismo
7.
Proc Natl Acad Sci U S A ; 117(42): 26356-26365, 2020 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-33020270

RESUMO

Understanding differences in DNA double-strand break (DSB) repair between tumor and normal tissues would provide a rationale for developing DNA repair-targeted cancer therapy. Here, using knock-in mouse models for measuring the efficiency of two DSB repair pathways, homologous recombination (HR) and nonhomologous end-joining (NHEJ), we demonstrated that both pathways are up-regulated in hepatocellular carcinoma (HCC) compared with adjacent normal tissues due to altered expression of DNA repair factors, including PARP1 and DNA-PKcs. Surprisingly, inhibiting PARP1 with olaparib abrogated HR repair in HCC. Mechanistically, inhibiting PARP1 suppressed the clearance of nucleosomes at DNA damage sites by blocking the recruitment of ALC1 to DSB sites, thereby inhibiting RPA2 and RAD51 recruitment. Importantly, combining olaparib with NU7441, a DNA-PKcs inhibitor that blocks NHEJ in HCC, synergistically suppressed HCC growth in both mice and HCC patient-derived-xenograft models. Our results suggest the combined inhibition of both HR and NHEJ as a potential therapy for HCC.


Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Cromonas/farmacologia , Morfolinas/farmacologia , Ftalazinas/farmacologia , Piperazinas/farmacologia , Animais , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Dano ao DNA , Reparo do DNA por Junção de Extremidades/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Proteínas de Ligação a DNA/metabolismo , Quimioterapia Combinada/métodos , Técnicas de Introdução de Genes , Recombinação Homóloga , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Camundongos , Camundongos Nus , Poli(ADP-Ribose) Polimerase-1/antagonistas & inibidores , Poli(ADP-Ribose) Polimerase-1/metabolismo , Reparo de DNA por Recombinação/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
8.
PLoS One ; 15(10): e0240844, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33079963

RESUMO

Cruciform DNA is a causing factor of genome instability and chromosomal translocation, however, most studies about cruciform DNA in mammalian cells were based on palindromic sequences containing plasmids and reports about endogenous cruciform DNA are rare. In this study we observed the dynamics of endogenous cruciform DNA in mouse growing oocytes using immunofluorescence labeling method. We found cruciform DNA foci exist in transcription active growing oocytes but not in transcription inactive fully grown oocytes and colocalized with Parp1 but not with DNA damage marker γH2A.X. By analyzing the Genotype-Tissue Expression data, we found cruciform DNA-mediated chromosomal translocation in human spermatocytes is associated with the specific DNA transcription in testis. When inhibiting the transcription with α-amanitin in mouse oocytes, we found oocyte cruciform DNA foci decreased significantly. In summary, we observed the endogenous cruciform DNA in growing oocytes and our results showed that the cruciform DNA formation is transcription-dependent.


Assuntos
DNA Cruciforme/metabolismo , Oócitos , Transcrição Genética/fisiologia , Alfa-Amanitina/efeitos adversos , Animais , Imunofluorescência/métodos , Histonas/metabolismo , Masculino , Camundongos , Oócitos/citologia , Oócitos/crescimento & desenvolvimento , Oogênese , Poli(ADP-Ribose) Polimerase-1/metabolismo , Espermatogênese , Testículo/citologia , Testículo/metabolismo
9.
Anesth Analg ; 131(5): 1616-1625, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33079886

RESUMO

BACKGROUND: Anesthesia in pregnant rodents causes neurotoxicity in fetal and offspring rodents. However, the underlying mechanisms and targeted treatments remain largely to be determined. Isoflurane and propofol are among commonly used anesthetics. Thus, we set out to investigate whether propofol can mitigate the isoflurane-induced neurotoxicity in mice. METHODS: Pregnant C57BL/6 mice at gestational day 15 (G15) were randomly assigned to 4 groups: control, isoflurane, propofol, and isoflurane plus propofol. Levels of interleukin (IL)-6 and poly-ADP ribose polymerase (PARP) fragment were measured in the brains of G15 embryos, and levels of postsynaptic density (PSD)-95 and synaptophysin were determined in the hippocampal tissues of postnatal day 31 (P31) offspring using Western blotting and immunohistochemical staining. Learning and memory functions in P31 offspring were determined using a Morris water maze test. RESULTS: Isoflurane anesthesia in pregnant mice at G15 significantly increased brain IL-6 (222.6% ± 36.45% vs 100.5% ± 3.43%, P < .0001) and PARP fragment (384.2% ± 50.87% vs 99.59% ± 3.25%, P < .0001) levels in fetal mice and reduced brain PSD-95 (30.76% ± 2.03% vs 100.8% ± 2.25%, P < .0001) and synaptophysin levels in cornu ammonis (CA) 1 region (57.08% ± 4.90% vs 100.6% ± 2.20%, P < .0001) and dentate gyrus (DG; 56.47% ± 3.76% vs 99.76% ± 1.09%, P < .0001) in P31 offspring. Isoflurane anesthesia also impaired cognitive function in offspring at P31. Propofol significantly mitigated isoflurane-induced increases in brain IL-6 (117.5% ± 10.37% vs 222.6% ± 36.45%, P < .0001) and PARP fragment (205.1% ± 35.99% vs 384.2% ± 50.87%, P < .0001) levels in fetal mice, as well as reductions in PSD-95 (49.79% ± 3.43% vs 30.76% ± 2.03%, P < .0001) and synaptophysin levels in CA1 region (85.57% ± 2.97% vs 57.08% ± 4.90%, P < .0001) and DG (85.05% ± 1.87% vs 56.47% ± 3.76%, P < .0001) in hippocampus of P31 offspring. Finally, propofol attenuated isoflurane-induced cognitive impairment in offspring. CONCLUSIONS: These findings suggest that gestational isoflurane exposure in mice induces neuroinflammation and apoptosis in embryos and causes cognitive impairment in offspring. Propofol can attenuate these isoflurane-induced detrimental effects.


Assuntos
Anestésicos Inalatórios/toxicidade , Anestésicos Intravenosos/farmacologia , Disfunção Cognitiva/induzido quimicamente , Disfunção Cognitiva/prevenção & controle , Isoflurano/antagonistas & inibidores , Isoflurano/toxicidade , Doenças do Sistema Nervoso/induzido quimicamente , Doenças do Sistema Nervoso/prevenção & controle , Propofol/farmacologia , Animais , Animais Recém-Nascidos , Química Encefálica/efeitos dos fármacos , Região CA1 Hipocampal/efeitos dos fármacos , Região CA1 Hipocampal/metabolismo , Disfunção Cognitiva/psicologia , Proteína 4 Homóloga a Disks-Large/metabolismo , Feminino , Feto , Interleucina-6/metabolismo , Aprendizagem em Labirinto , Camundongos , Camundongos Endogâmicos C57BL , Poli(ADP-Ribose) Polimerase-1/metabolismo , Gravidez , Sinaptofisina/metabolismo
10.
Nat Commun ; 11(1): 5239, 2020 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-33067475

RESUMO

The alternative non-homologous end-joining (NHEJ) pathway promotes DNA double-strand break (DSB) repair in cells deficient for NHEJ or homologous recombination, suggesting that it operates at all stages of the cell cycle. Here, we use an approach in which DNA breaks can be induced in G1 cells and their repair tracked, enabling us to show that joining of DSBs is not functional in G1-arrested XRCC4-deficient cells. Cell cycle entry into S-G2/M restores DSB repair by Pol θ-dependent and PARP1-independent alternative NHEJ with repair products bearing kilo-base long DNA end resection, micro-homologies and chromosome translocations. We identify a synthetic lethal interaction between XRCC4 and Pol θ under conditions of G1 DSBs, associated with accumulation of unresolved DNA ends in S-G2/M. Collectively, our results support the conclusion that the repair of G1 DSBs progressing to S-G2/M by alternative NHEJ drives genomic instability and represent an attractive target for future DNA repair-based cancer therapies.


Assuntos
Ciclo Celular , Quebras de DNA de Cadeia Dupla , Reparo do DNA por Junção de Extremidades , Animais , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Fase G1 , Camundongos , Poli(ADP-Ribose) Polimerase-1/genética , Poli(ADP-Ribose) Polimerase-1/metabolismo
11.
J Food Sci ; 85(11): 4070-4079, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33089532

RESUMO

Piperine, a bioactive alkaloid, is known to have anticancer activities. Hence, in this study, the effectiveness of piperine pretreatment as a strategy for radio-sensitizing colorectal adenocarcinoma cell line (HT-29) was analyzed. For this, HT-29 cells were pretreated with piperine (12.5 and 25 µg/mL) and exposed to γ-radiation (1.25 Gy) and analyzed for various effector pathways to elucidate the possible mode of action in comparison to individual treatments. The proliferation efficiency of the cells was analyzed by trypan blue dye exclusion assay and MTT assay. The synergistic effects of the combination treatment were analyzed with compuSyn software. Downstream signaling pathways leading to apoptosis were studied using flowcytometry, immunofluorescence, and immunoblot assays. It was observed that combination treatment arrested HT-29 cells at G2/M phase nearly 2.8 folds higher than radiation treatment alone, inducing the radio-resistant cells to undergo apoptosis through mitochondria-dependent pathway. In addition, activation of caspase-3 and cleavage of poly(ADP-ribose) polymerases-1, the key molecular events in apoptotic signaling, were significantly enhanced. Activation of estrogen receptor beta (ERß), a nuclear hormone transcription factor promoting tumor suppression represents a novel clinical advance towards management and prevention of cancers. Interestingly, the expression of ERß was increased in the cells treated with piperine. In conclusion, piperine pretreatment enhances radio-sensitization in HT-29 cells by inducing the cells to undergo apoptosis hence, can be used as a classic candidate for colon cancer sensitization towards radiotherapy. PRACTICAL APPLICATION: Piperine induces enhanced radiosensitization of colon cancer cell line (HT-29) by interfering with the cancer cell line proliferation, DNA damage, and apoptosis.


Assuntos
Alcaloides/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Benzodioxóis/farmacologia , Neoplasias/fisiopatologia , Piperidinas/farmacologia , Alcamidas Poli-Insaturadas/farmacologia , Caspase 3/genética , Caspase 3/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Células HT29 , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/efeitos da radiação , Neoplasias/genética , Neoplasias/metabolismo , Poli(ADP-Ribose) Polimerase-1/genética , Poli(ADP-Ribose) Polimerase-1/metabolismo , Radiação , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/efeitos da radiação
12.
Biosci Rep ; 40(10)2020 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-33063092

RESUMO

COVID-19 induces a proinflammatory environment that is stronger in patients requiring intensive care. The cytokine components of this environment may determine efficacy or otherwise of glucocorticoid therapy. The immunity modulators, the aryl hydrocarbon receptor (AhR) and the nuclear NAD+-consuming enzyme poly (ADP-ribose) polymerase 1 (PARP 1) may play a critical role in COVID-19 pathophysiology. The AhR is overexpressed in coronaviruses, including COVID-19 and, as it regulates PARP gene expression, the latter is likely to be activated in COVID-19. PARP 1 activation leads to cell death mainly by depletion of NAD+ and adenosine triphosphate (ATP), especially when availability of these energy mediators is compromised. PARP expression is enhanced in other lung conditions: the pneumovirus respiratory syncytial virus (RSV) and chronic obstructive pulmonary disease (COPD). I propose that PARP 1 activation is the terminal point in a sequence of events culminating in patient mortality and should be the focus of COVID-19 immunotherapy. Potent PARP 1 inhibitors are undergoing trials in cancer, but a readily available inhibitor, nicotinamide (NAM), which possesses a highly desirable biochemical and activity profile, merits exploration. It conserves NAD+ and prevents ATP depletion by PARP 1 and Sirtuin 1 (silent mating type information regulation 2 homologue 1) inhibition, enhances NAD+ synthesis, and hence that of NADP+ which is a stronger PARP inhibitor, reverses lung injury caused by ischaemia/reperfusion, inhibits proinflammatory cytokines and is effective against HIV infection. These properties qualify NAM for therapeutic use initially in conjunction with standard clinical care or combined with other agents, and subsequently as an adjunct to stronger PARP 1 inhibitors or other drugs.


Assuntos
Infecções por Coronavirus/tratamento farmacológico , Niacinamida/farmacologia , Pneumonia Viral/tratamento farmacológico , Poli(ADP-Ribose) Polimerase-1/antagonistas & inibidores , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Betacoronavirus/efeitos dos fármacos , Linhagem Celular , Infecções por Coronavirus/patologia , Citocinas/sangue , Humanos , Imunoterapia/métodos , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Cinurenina/metabolismo , Pandemias , Pneumonia Viral/patologia , Poli(ADP-Ribose) Polimerase-1/metabolismo , Receptores de Hidrocarboneto Arílico/metabolismo
13.
J Med Chem ; 63(19): 11012-11033, 2020 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-32924477

RESUMO

The nuclear protein poly(ADP-ribose) polymerase-1 (PARP1) has a well-established role in the signaling and repair of DNA and is a validated therapeutic target for cancers and other human diseases. Here, we have designed, synthesized, and evaluated a series of small-molecule PARP1 degraders based on the proteolysis-targeting chimera (PROTAC) concept. Our efforts have led to the discovery of highly potent PARP1 degraders, as exemplified by compound 18 (SK-575). SK-575 potently inhibits the growth of cancer cells bearing BRCA1/2 mutations and induces potent and specific degradation of PARP1 in various human cancer cells even at low picomolar concentrations. SK-575 achieves durable tumor growth inhibition in mice when used as a single agent or in combination with cytotoxic agents, such as temozolomide and cisplatin. These data demonstrate that SK-575 is a highly potent and efficacious PARP1 degrader.


Assuntos
Antineoplásicos/uso terapêutico , Quimera , Desenho de Fármacos , Neoplasias/tratamento farmacológico , Ftalazinas/química , Piperazinas/química , Poli(ADP-Ribose) Polimerase-1/metabolismo , Animais , Antineoplásicos/química , Linhagem Celular Tumoral , Humanos , Ligantes , Camundongos , Proteólise
14.
Life Sci ; 260: 118472, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32971106

RESUMO

AIMS: Testicular torsion/detorsion (T/D) is a critical medical condition that necessitates prompt surgical intervention to avoid testicular atrophy and infertility. The use of natural compounds may protect against the associated detrimental oxidative stress and inflammatory responses. Interestingly, acetyl-11-keto-ß-boswellic acid (AKBA), the main active constituent of Boswellia resin, has shown potent inhibitory effect on 5-lipoxygenase enzyme which converts arachidonic acid into inflammatory mediators. Therefore, this study was conducted to assess the protective mechanisms by which AKBA may protect against testicular T/D injury in rats. MAIN METHODS: Male rats were randomly distributed into five groups: Sham, AKBA (50 mg/kg, p.o.), unilateral testicular T/D, AKBA at two dose levels (25 or 50 mg/kg for 15 successive days) followed by T/D. Histological examination and Johnsen's score were performed to assess testicular injury and perturbations in spermatogenesis. Biochemical parameters included markers of testicular function (serum testosterone), oxidant/antioxidant status (malondialdehyde, glutathione), inflammation (5-lipoxygenase, leukotriene-B4, myeloperoxidase, interleukin-1ß, interleukin-6), apoptosis (Bax, Bcl2, caspase-3), DNA integrity (quantitative DNA fragmentation, DNA laddering, PARP-1), energy production (ATP), in addition to p38 MAPK and JNK protein expression. KEY FINDINGS: In a dose dependent manner, AKBA significantly inhibited testicular T/D-induced upregulation of 5-LOX/LTB4 and p38-MAPK/JNK/Bax pathways and their associated downstream inflammatory and apoptotic cascades. These effects were accompanied with ATP replenishment and DNA preservation, resulting ultimately in salvage of the testis. SIGNIFICANCE: Unprecedentedly, the present mechanistic study revealed the pathways by which AKBA may inhibit testicular T/D injury and offered a novel protective approach that may attenuate the severity of this condition.


Assuntos
Araquidonato 5-Lipoxigenase/metabolismo , Torção do Cordão Espermático/metabolismo , Torção do Cordão Espermático/prevenção & controle , Testículo/efeitos dos fármacos , Triterpenos/farmacologia , Trifosfato de Adenosina/metabolismo , Animais , Caspase 3/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Leucotrieno B4/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Redes e Vias Metabólicas/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Poli(ADP-Ribose) Polimerase-1/metabolismo , Ratos Wistar , Testículo/metabolismo , Testículo/patologia , Testosterona/metabolismo , Triterpenos/administração & dosagem , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
15.
Nucleic Acids Res ; 48(17): 9694-9709, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32890402

RESUMO

DNA breaks recruit and activate PARP1/2, which deposit poly-ADP-ribose (PAR) to recruit XRCC1-Ligase3 and other repair factors to promote DNA repair. Clinical PARP inhibitors (PARPi) extend the lifetime of damage-induced PARP1/2 foci, referred to as 'trapping'. To understand the molecular nature of 'trapping' in cells, we employed quantitative live-cell imaging and fluorescence recovery after photo-bleaching. Unexpectedly, we found that PARP1 exchanges rapidly at DNA damage sites even in the presence of clinical PARPi, suggesting the persistent foci are not caused by physical stalling. Loss of Xrcc1, a major downstream effector of PAR, also caused persistent PARP1 foci without affecting PARP1 exchange. Thus, we propose that the persistent PARP1 foci are formed by different PARP1 molecules that are continuously recruited to and exchanging at DNA lesions due to attenuated XRCC1-LIG3 recruitment and delayed DNA repair. Moreover, mutation analyses of the NAD+ interacting residues of PARP1 showed that PARP1 can be physically trapped at DNA damage sites, and identified H862 as a potential regulator for PARP1 exchange. PARP1-H862D, but not PARylation-deficient PARP1-E988K, formed stable PARP1 foci upon activation. Together, these findings uncovered the nature of persistent PARP1 foci and identified NAD+ interacting residues involved in the PARP1 exchange.


Assuntos
Dano ao DNA , Reparo do DNA/efeitos dos fármacos , Poli(ADP-Ribose) Polimerase-1/genética , Poli(ADP-Ribose) Polimerase-1/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Sítios de Ligação , Domínio Catalítico , Linhagem Celular Tumoral , Reparo do DNA/fisiologia , Transferência Ressonante de Energia de Fluorescência , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Indazóis/farmacologia , Cinética , Imagem Molecular , NAD/metabolismo , Piperidinas/farmacologia , Poli(ADP-Ribose) Polimerases/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteína 1 Complementadora Cruzada de Reparo de Raio-X/genética , Proteína 1 Complementadora Cruzada de Reparo de Raio-X/metabolismo
16.
Anticancer Res ; 40(9): 4907-4912, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32878778

RESUMO

BACKGROUND/AIM: We investigated the effects of luteolin (LUT) on classical Hodgkin's lymphoma (cHL), since such studies in malignant lymphomas are lacking. MATERIALS AND METHODS: Effect of LUT on cell growth was assessed with water-soluble tetrazolium 1 (WST-1) cell proliferation assay and automated hemocytometry on trypan blue-exclusion assay. Cell death was investigated with acridine orange/ethidium bromide live-dead assay, propidium iodide (PI) flow cytometry, and Annexin-V-PI microscopy. Caspase activation was studied using CellEvent Caspase-3/7 Green detection reagent. High resolution immunofluorescence microscopy was used to detect cleaved-PARP-1. RESULTS: LUT induced a dose-dependent decrease in the growth of KMH2 and L428 cells, cellular models of mix-cellularity (MC) and nodular sclerosis (NS) cHL, respectively. However, LUT induced cell death only in KMH2, at a higher concentration, and this was associated with caspase activation and cleaved PARP-1. CONCLUSION: LUT induces cytotoxicity in the MC-cHL cellular model KMH2 via caspase activation.


Assuntos
Antineoplásicos/farmacologia , Caspases/metabolismo , Morte Celular/efeitos dos fármacos , Luteolina/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Doença de Hodgkin/tratamento farmacológico , Doença de Hodgkin/patologia , Humanos , Poli(ADP-Ribose) Polimerase-1/metabolismo
17.
Sci Rep ; 10(1): 14253, 2020 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-32859985

RESUMO

Persistent R-loops (RNA-DNA hybrids with a displaced single-stranded DNA) create DNA damage and lead to genomic instability. The 5'-3'-exoribonuclease 2 (XRN2) degrades RNA to resolve R-loops and promotes transcription termination. Previously, XRN2 was implicated in DNA double strand break (DSB) repair and in resolving replication stress. Here, using tandem affinity purification-mass spectrometry, bioinformatics, and biochemical approaches, we found that XRN2 associates with proteins involved in DNA repair/replication (Ku70-Ku80, DNA-PKcs, PARP1, MCM2-7, PCNA, RPA1) and RNA metabolism (RNA helicases, PRP19, p54(nrb), splicing factors). Novel major pathways linked to XRN2 include cell cycle control of chromosomal replication and DSB repair by non-homologous end joining. Investigating the biological implications of these interactions led us to discover that XRN2 depletion compromised cell survival after additional knockdown of specific DNA repair proteins, including PARP1. XRN2-deficient cells also showed enhanced PARP1 activity. Consistent with concurrent depletion of XRN2 and PARP1 promoting cell death, XRN2-deficient fibroblast and lung cancer cells also demonstrated sensitivity to PARP1 inhibition. XRN2 alterations (mutations, copy number/expression changes) are frequent in cancers. Thus, PARP1 inhibition could target cancers exhibiting XRN2 functional loss. Collectively, our data suggest XRN2's association with novel protein partners and unravel synthetic lethality between XRN2 depletion and PARP1 inhibition.


Assuntos
Exorribonucleases/metabolismo , Poli(ADP-Ribose) Polimerase-1/metabolismo , Estruturas R-Loop/fisiologia , Células A549 , Quebras de DNA de Cadeia Dupla , Dano ao DNA/fisiologia , Reparo do DNA por Junção de Extremidades/fisiologia , Reparo do DNA/fisiologia , Replicação do DNA/fisiologia , Proteínas de Ligação a DNA/genética , Exorribonucleases/fisiologia , Instabilidade Genômica/fisiologia , Células HEK293 , Células HeLa , Humanos , Poli(ADP-Ribose) Polimerase-1/fisiologia , Poli(ADP-Ribose) Polimerases/metabolismo , Estruturas R-Loop/genética , RNA Helicases/metabolismo , Mutações Sintéticas Letais/genética
18.
Sci Rep ; 10(1): 13907, 2020 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-32807821

RESUMO

Cytidine deaminase (CDA) deficiency causes pyrimidine pool disequilibrium. We previously reported that the excess cellular dC and dCTP resulting from CDA deficiency jeopardizes genome stability, decreasing basal poly(ADP-ribose) polymerase 1 (PARP-1) activity and increasing ultrafine anaphase bridge (UFB) formation. Here, we investigated the mechanism underlying the decrease in PARP-1 activity in CDA-deficient cells. PARP-1 activity is dependent on intracellular NAD+ concentration. We therefore hypothesized that defects of the NAD+ salvage pathway might result in decreases in PARP-1 activity. We found that the inhibition or depletion of nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in the NAD+ salvage biosynthesis pathway, mimicked CDA deficiency, resulting in a decrease in basal PARP-1 activity, regardless of NAD+ levels. Furthermore, the expression of exogenous wild-type NAMPT fully restored basal PARP-1 activity and prevented the increase in UFB frequency in CDA-deficient cells. No such effect was observed with the catalytic mutant. Our findings demonstrate that (1) the inhibition of NAMPT activity in CDA-proficient cells lowers basal PARP-1 activity, and (2) the expression of exogenous wild-type NAMPT, but not of the catalytic mutant, fully restores basal PARP-1 activity in CDA-deficient cells; these results strongly suggest that basal PARP-1 activity in CDA-deficient cells decreases due to a reduction of NAMPT activity.


Assuntos
Citidina Desaminase/deficiência , NAD/metabolismo , Poli(ADP-Ribose) Polimerase-1/metabolismo , Citidina Desaminase/metabolismo , Citocinas/antagonistas & inibidores , Citocinas/genética , Citocinas/metabolismo , Células HeLa , Humanos , Mutação/genética , Niacinamida/metabolismo , Nicotinamida Fosforribosiltransferase/antagonistas & inibidores , Nicotinamida Fosforribosiltransferase/genética , Nicotinamida Fosforribosiltransferase/metabolismo
19.
BMC Complement Med Ther ; 20(1): 218, 2020 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-32660602

RESUMO

BACKGROUND: Pulmonary artery hypertension (PAH) is a vascular disease in the lung characterized by elevated pulmonary arterial pressure (PAP). Many miRNAs play a role in the pathophysiology of PAH. Perillyle alcohol (PA) and Quercetin (QS) are plant derivatives with antioxidant and anti-proliferative properties. We investigated the effect of PA and QS on PAP, expression of PARP1, miR-204, and their targets, HIF1α and NFATc2, in experimental PAH. METHODS: Thirty rats were divided into control, MCT, MCT + Veh, MCT + PA and MCT + QS groups. MCT (60 mg/kg) was injected subcutaneously to induce PAH. PA (50 mg/kg daily) and QS (30 mg/kg daily) were administered for 3 weeks after inducing PAH. PAP, lung pathology, expression of miRNA and mRNA, and target proteins were evaluated through right ventricle cannulation, H&E staining, real-time qPCR, and western blotting, respectively. RESULTS: Inflammation and lung arteriole thickness in the MCT group increased compared to control group. PA and QS ameliorated inflammation and reduced arteriole thickness significantly. miR-204 expression decreased in PAH rats (p < 0.001). PA (p < 0.001) and QS (p < 0.01) significantly increased miR-204 expression. Expression of PARP1, HIF1α, NFATc2, and α-SMA mRNA increased significantly in MCT + veh rats (all p < 0.001), and these were reduced after treatment with PA and QS (both p < 0.01). PA and QS also decreased the expression of PARP1, HIF1α, and NFATc2 proteins that had increased in MCT + Veh group. CONCLUSION: PA and QS improved PAH possibly by affecting the expression of PARP1 and miR-204 and their downstream targets, HIF1a and NFATc2. PA and QS may be therapeutic goals in the treatment of PAH.


Assuntos
Hipertensão Pulmonar/tratamento farmacológico , MicroRNAs/metabolismo , Monoterpenos/farmacologia , Poli(ADP-Ribose) Polimerase-1/metabolismo , Quercetina/farmacologia , Animais , Modelos Animais de Doenças , Regulação para Baixo , Hipertrofia Ventricular Direita/tratamento farmacológico , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Masculino , Monocrotalina , Fatores de Transcrição NFATC/metabolismo , Artéria Pulmonar , Ratos , Ratos Wistar
20.
Am J Respir Cell Mol Biol ; 63(5): 571-590, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32640172

RESUMO

PARP1, the major isoform of a family of ADP-ribosylating enzymes, has been implicated in the regulation of various biological processes including DNA repair, gene transcription, and cell death. The concept that PARP1 becomes activated in acute lung injury (ALI) and that pharmacological inhibition or genetic deletion of this enzyme can provide therapeutic benefits emerged over 20 years ago. The current article provides an overview of the cellular mechanisms involved in the pathogenetic roles of PARP1 in ALI and provides an overview of the preclinical data supporting the efficacy of PARP (poly[ADP-ribose] polymerase) inhibitors. In recent years, several ultrapotent PARP inhibitors have been approved for clinical use (for the therapy of various oncological diseases): these newly-approved PARP inhibitors were recently reported to show efficacy in animal models of ALI. These observations offer the possibility of therapeutic repurposing of these inhibitors for patients with ALI. The current article lays out a potential roadmap for such repurposing efforts. In addition, the article also overviews the scientific basis of potentially applying PARP inhibitors for the experimental therapy of viral ALI, such as coronavirus disease (COVID-19)-associated ALI.


Assuntos
Lesão Pulmonar Aguda/tratamento farmacológico , Antivirais/uso terapêutico , Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/tratamento farmacológico , Pulmão/efeitos dos fármacos , Pneumonia Viral/tratamento farmacológico , Poli(ADP-Ribose) Polimerase-1/antagonistas & inibidores , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Lesão Pulmonar Aguda/enzimologia , Lesão Pulmonar Aguda/virologia , Animais , Antivirais/efeitos adversos , Betacoronavirus/patogenicidade , Infecções por Coronavirus/enzimologia , Infecções por Coronavirus/virologia , Interações Hospedeiro-Patógeno , Humanos , Pulmão/enzimologia , Pulmão/virologia , Pandemias , Pneumonia Viral/enzimologia , Pneumonia Viral/virologia , Poli(ADP-Ribose) Polimerase-1/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/efeitos adversos , Transdução de Sinais/efeitos dos fármacos
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