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1.
Braz. j. biol ; 84: e251289, 2024. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1355889

RESUMO

Abstract The present research was made to determine the micronuclei and cytotoxic capacity of the antidepressant venlafaxine in an in vivo acute and subchronic assays in mouse. In the first study, we administered once 5, 50, and 250 mg/kg of the drug, and included a negative and a daunorubicin treated group. Observations were daily made during four days. The subchronic assay lasted 5 weeks with daily administration of venlafaxine (1, 5, and 10 mg/kg) plus a negative and an imipramine administered groups. Observations were made each week. In the first assay results showed no micronucleated polychromatic erythrocytes (MNPE) increase, except with the high dose at 72 h. The strongest cytotoxic effect was found with 250 mg/kg at 72 h (a 51% cytotoxic effect in comparison with the mean control level). In the subchronic assay no MNPE increase was found; however, with the highest dose a significant increase of micronucleated normochromatic erythrocytes was observed in the last three weeks (a mean of 51% respect to the mean control value). A cytotoxic effect with the two high doses in the last two weeks was observed (a polychromatic erythrocyte mean decrease of 52% respect to the mean control value). Results suggest caution with venlafaxine.


Resumo A presente pesquisa foi feita para determinar a capacidade micronuclei e citotóxica do antidepressivo venlafaxina em ensaios agudos e subcrônicos in vivo em camundongos. No primeiro estudo, administramos uma vez 5, 50 e 250 mg/kg do medicamento e incluímos um grupo negativo e um grupo tratado com daunorubicina. As observações foram feitas diariamente durante quatro dias. O ensaio subcrônico durou cinco semanas com administração diária de venlafaxina (1, 5, e 10 mg/kg) mais um grupo negativo e um grupo administrado de imipramina. As observações foram feitas a cada semana. No primeiro ensaio, os resultados não mostraram aumento de eritrócitos policromáticos micronucleados (MNPE), exceto com a dose elevada a 72 h. O efeito citotóxico mais forte foi encontrado com 250 mg/kg a 72 h (um efeito citotóxico de 51% em comparação com o nível médio de controle). No ensaio subcrônico não foi encontrado aumento de MNPE; entretanto, com a dose mais alta, um aumento significativo de eritrócitos normocromáticos micronucleados foi observado nas últimas três semanas (média de 51% em relação ao valor médio de controle). Foi observado um efeito citotóxico com as duas altas doses nas últimas duas semanas (uma diminuição média de 52% em relação ao valor médio de controle dos eritrócitos policromáticos). Os resultados sugerem cautela com a venlafaxina.


Assuntos
Animais , Coelhos , Dano ao DNA , Antineoplásicos , Testes para Micronúcleos , Relação Dose-Resposta a Droga , Eritrócitos , Cloridrato de Venlafaxina/toxicidade
2.
Methods Mol Biol ; 2519: 9-15, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36066705

RESUMO

Chromosomal aberrations are changes in structure and number of chromosomes. Metaphase chromosome can be analyzed by a standard light microscope to detect chromosomal aberrations. Recently, detailed analysis or rapid analysis was possible by using fluorescence probes and fluorescent microscope. The origins of chromosomal aberrations can be errors of DNA repair, cell divisions, and DNA synthesis. Analysis of chromosome aberrations can be used for the wide range of analysis. It includes a basic science connecting DNA damage to cellular death and mutagenesis and diagnostic tools for hereditary diseases and biodosimetry following radiation exposure.Specific DNA damages produce unique types of chromosomal aberrations. Analysis of chromosomal aberrations enables us to investigate the mechanisms of genotoxic stress. However, one type of DNA damage provides a variety of changes in chromosome structures. It is often confusing. This chapter introduces the standard technique of metaphase chromosome spread preparation and typical classification of chromosomal aberrations.


Assuntos
Aberrações Cromossômicas , Cromossomos , Dano ao DNA , Reparo do DNA , Humanos , Metáfase
3.
Methods Mol Biol ; 2519: 65-72, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36066710

RESUMO

The comet assay is an effective method for identifying DNA breaks and alkali-labile sites induced by genotoxins. Performed as a single-cell electrophoresis, this assay is especially simplistic, and the results are easily reproducible. DNA breakage can be quantitatively assessed by the induced comet tail regions, which can be measured using a variety of comet software. This protocol will finish within approximately two hours with adequate preparation, and digitized images can be taken using a confocal or standard fluorescence microscopes after staining the cell nucleus with a DNA dye.


Assuntos
Dano ao DNA , Mutagênicos , Ensaio Cometa/métodos , DNA , Coloração e Rotulagem
4.
Methods Mol Biol ; 2519: 93-98, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36066713

RESUMO

After DNAs are damaged, DNA repair proteins accumulate and are activated at the DNA damaged site. These accumulated proteins are visualized as foci by fluorescent immunocytochemistry technique. This allows the DNA damage responses in interphase nuclei to be detected; it was earlier times difficult to analyze DNA damage in situ. In order to analyze DNA damage in interphase cells, either DNA is extracted to assay breaks biochemically, or premature chromosome condensation is conducted to observe as chromatin breaks. Although DNA damage-induced foci are typically analyzed in interphase cells, these foci can be also visualized on mitotic chromosomes. The foci where the repair proteins accumulate at the damage site is observed as mitotic chromosome break site. Since mitotic cells attach loosely or not attached to cell culture vessels, it is difficult to analyze foci on chromosomes in culture vessels under a microscope, so metaphase chromosome spread must be prepared for accurate analysis. The cytocentrifuge system is an ideal method to adhere mitotic cells to microscope slides for the fluorescent immunocytochemistry. This chapter introduces cytocentrifuge method to prepare metaphase spread for DNA damage foci analysis.


Assuntos
Cromossomos , Dano ao DNA , DNA , Interfase , Metáfase
5.
Braz. j. biol ; 83: e251198, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1339350

RESUMO

Abstract The present study was designed to investigate the effects of Gundelia tournefortii L. plant extract on different tissues in terms of DNA damage, biochemical and antioxidant parameter values in rats with high-calorie diets. With this aim, Wistar albino male rats were divided into 4 groups containing 6 rats each and the study was completed over 12 weeks duration. At the end of the implementation process over the 12 weeks, rats were sacrificed and blood and tissue samples were obtained. Analyses were performed on blood and tissue samples. According to results for DNA damage (8-OHdG), in brain tissue the OG2 group was significantly reduced compared to the NC group. For MDA results in liver tissue, OG1 and OG2 groups were determined to increase by a significant degree compared to the control group, while the OG2 group was also increased significantly compared to the obese group. In terms of the other parameters, comparison between the groups linked to consumption of a high calorie diet (HCD) and administration of Gundelia tournefortii L. in terms of antioxidant activities and serum samples obtained statistically significant results. Gundelia tournefortii L. plant extracts had effects that may be counted as positive on antioxidant parameter activity and were especially identified to improve DNA damage and MDA levels in brain tissues. Additionally, consumption of Gundelia tournefortii L. plant extract in the diet may have antiobesity effects; thus, it should be evaluated for use as an effective weight-loss method and as a new therapeutic agent targeting obesity.


Resumo O presente estudo foi desenhado para investigar os efeitos do extrato da planta Gundelia tournefortii L. em diferentes tecidos em termos de danos ao DNA, valores de parâmetros bioquímicos e antioxidantes em ratos com dietas hipercalóricas. Com esse objetivo, ratos Wistar albinos machos foram divididos em 4 grupos contendo 6 ratos cada e o estudo foi concluído ao longo de 12 semanas de duração. No final desse processo de implementação, os ratos foram sacrificados e amostras de sangue e tecido foram obtidas. As análises foram realizadas em amostras de sangue e tecido. De acordo com os resultados para danos ao DNA (8-OHdG), no tecido cerebral o grupo OG2 foi significativamente reduzido em comparação com o grupo NC. Para os resultados de MDA no tecido hepático, os grupos OG1 e OG2 aumentaram significativamente em comparação ao grupo controle, enquanto o grupo OG2 também aumentou significativamente em comparação ao grupo obeso. Quanto aos demais parâmetros, a comparação entre os grupos ligados ao consumo de dieta hipercalórica (DC) e à administração de Gundelia tournefortii L. em termos de atividades antioxidantes e amostras de soro obteve resultados estatisticamente significativos. Os extratos de plantas de Gundelia tournefortii L. tiveram efeitos que podem ser considerados positivos na atividade dos parâmetros antioxidantes e foram especialmente identificados para melhorar os danos ao DNA e os níveis de MDA nos tecidos cerebrais. Além disso, o consumo de extrato vegetal de Gundelia tournefortii L. na dieta pode ter efeitos antiobesidade; portanto, deve ser avaliado para uso como um método eficaz de perda de peso e como um novo agente terapêutico voltado para a obesidade.


Assuntos
Animais , Ratos , Asteraceae , Antioxidantes , Dano ao DNA , Extratos Vegetais/farmacologia , Ratos Wistar , Obesidade/tratamento farmacológico
6.
Braz. j. biol ; 83: e240118, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1278559

RESUMO

Abstract For many centuries human populations have been suffering and trying to fight with disease-bearing mosquitoes. Emerging and reemerging diseases such as Dengue, Zika, and Chikungunya affect billions of people around the world and recently has been appealing to control with chemical pesticides. Malathion (MT) is one of the main pesticides used against mosquitoes, the vectors of these diseases. This study aimed to assess cytotoxicity and mutagenicity of the malathion for the bioindicator Allium cepa L. using a multivariate and integrative approach. Moreover, an appendix table was compiled with all available literature of insecticides assessed by the Allium cepa system to support our discussion. Exposures during 48h to 0.5 mg mL-1 and 1.0 mg mL-1 MT were compared to the negative control (distilled water) and positive control (MMS solution at 10 mg L-1). The presence of chromosomal aberrations, micronuclei frequency, and mitotic index abnormalities was evaluated. Anaphase bridges were the alterations with higher incidence and presented a significantly elevated rate in the concentration of 0.5 mg mL-1, including when compared to the positive control. The integrative discriminant analysis summarizes that MT in assessed concentrations presented effects like the positive control, corroborating its potential of toxicity to DNA. Therefore, it is concluded that MT in its pure composition and in realistic concentrations used, has genotoxic potential in the biological assessment of A. cepa cells. The multivariate integrative analysis was fundamental to show a whole response of all data, providing a global view of the effect of MT on DNA.


Resumo Por muitos séculos, as populações humanas sofrem e tentam combater os mosquitos transmissores de doenças. Doenças emergentes e reemergentes como Dengue, Zika e Chikungunya afetam bilhões de pessoas em todo o mundo e, recentemente, vem apelando ao controle com pesticidas químicos. O Malation (MT) é um dos principais pesticidas usados ​​contra mosquitos, vetores dessas doenças. O objetivo deste estudo foi avaliar a citotoxicidade e a mutagenicidade do MT para o bioindicador Allium cepa L. usando uma abordagem multivariada e integrativa. Além disso, uma tabela suplementar foi compilada com toda a literatura disponível de inseticidas avaliada pelo sistema Allium cepa para apoiar nossa discussão. Exposições ao MT durante 48h a 0,5 mg mL-1 e 1,0 mg mL-1 foram comparadas a um controle negativo (água destilada) e um controle positivo (10 mg L-1 de MMS). Foram avaliadas a presença de aberrações cromossômicas, frequência de micronúcleos e anormalidades no índice mitótico. As pontes anafásicas foram as alterações com maior incidência e apresentaram uma taxa significativamente elevada na concentração de 0,5 mg mL-1, inclusive quando comparadas ao controle positivo. A análise discriminante integrativa resume que o MT nas concentrações avaliadas apresentou efeitos semelhantes ao controle positivo, corroborando seu potencial de toxicidade para o DNA. Portanto, conclui-se que o MT, em sua composição pura e nas concentrações realistas utilizadas, possui potencial genotóxico na avaliação biológica de células de A. cepa. A análise integrativa multivariada foi fundamental para mostrar uma resposta completa de todos os dados, fornecendo uma visão global do efeito da MT no DNA.


Assuntos
Humanos , Animais , Zika virus , Infecção por Zika virus , Inseticidas/toxicidade , Dano ao DNA , Aberrações Cromossômicas , Raízes de Plantas , Cebolas , Mosquitos Vetores , Malation/toxicidade , Índice Mitótico
7.
Braz. j. biol ; 83: e243910, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1278525

RESUMO

Abstract Nucleotide excision repair (NER) acts repairing damages in DNA, such as lesions caused by cisplatin. Xeroderma Pigmentosum complementation group C (XPC) protein is involved in recognition of global genome DNA damages during NER (GG-NER) and it has been studied in different organisms due to its importance in other cellular processes. In this work, we studied NER proteins in Trypanosoma cruzi and Trypanosoma evansi, parasites of humans and animals respectively. We performed three-dimensional models of XPC proteins from T. cruzi and T. evansi and observed few structural differences between these proteins. In our tests, insertion of XPC gene from T. evansi (TevXPC) in T. cruzi resulted in slower cell growth under normal conditions. After cisplatin treatment, T. cruzi overexpressing its own XPC gene (TcXPC) was able to recover cell division rates faster than T. cruzi expressing TevXPC gene. Based on these tests, it is suggested that TevXPC (being an exogenous protein in T. cruzi) interferes negatively in cellular processes where TcXPC (the endogenous protein) is involved. This probably occurred due interaction of TevXPC with some endogenous molecules or proteins from T.cruzi but incapacity of interaction with others. This reinforces the importance of correctly XPC functioning within the cell.


Resumo O reparo por excisão de nucleotídeos (NER) atua reparando danos no DNA, como lesões causadas por cisplatina. A proteína Xeroderma Pigmentosum complementation group C (XPC) está envolvida no reconhecimento de danos pela via de reparação global do genoma pelo NER (GG-NER) e tem sido estudada em diferentes organismos devido à sua importância em outros processos celulares. Neste trabalho, estudamos proteínas do NER em Trypanosoma cruzi e Trypanosoma evansi, parasitos de humanos e animais, respectivamente. Modelos tridimensionais das proteínas XPC de T. cruzi e T. evansi foram feitos e observou-se poucas diferenças estruturais entre estas proteínas. Durante testes, a inserção do gene XPC de T. evansi (TevXPC) em T. cruzi resultou em crescimento celular mais lento em condições normais. Após o tratamento com cisplatina, T. cruzi superexpressando seu próprio gene XPC (TcXPC) foi capaz de recuperar as taxas de divisão celular mais rapidamente do que T. cruzi expressando o gene TevXPC. Com base nesses testes, sugere-se que TevXPC (sendo uma proteína exógena em T. cruzi) interfere negativamente nos processos celulares em que TcXPC (a proteína endógena) está envolvida. Isso provavelmente ocorreu pois TevXPC é capaz de interagir com algumas moléculas ou proteínas endógenas de T.cruzi, mas é incapaz de interagir com outras. Isso reforça a importância do correto funcionamento de XPC dentro da célula.


Assuntos
Humanos , Animais , Trypanosoma cruzi/genética , Xeroderma Pigmentoso , Dano ao DNA/genética , Biologia Computacional , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Reparo do DNA/genética
8.
Mol Hum Reprod ; 28(1)2022 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-34954800

RESUMO

Sperm DNA damage is considered a predictive factor for the clinical outcomes of patients undergoing ART. Laboratory evidence suggests that zygotes and developing embryos have adopted specific response and repair mechanisms to repair DNA damage of paternal origin. We have conducted a systematic review in accordance with guidelines from Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) to identify and review the maternal mechanisms used to respond and repair sperm DNA damage during early embryonic development, how these mechanisms operate and their potential clinical implications. The literature search was conducted in Ovid MEDLINE and Embase databases until May 2021. Out of 6297 articles initially identified, 36 studies were found to be relevant through cross referencing and were fully extracted. The collective evidence in human and animal models indicate that the early embryo has the capacity to repair DNA damage within sperm by activating maternally driven mechanisms throughout embryonic development. However, this capacity is limited and likely declines with age. The link between age and decreased DNA repair capacity could explain decreased oocyte quality in older women, poor reproductive outcomes in idiopathic cases and patients who present high sperm DNA damage. Ultimately, further understanding mechanisms underlying the maternal repair of sperm DNA damage could lead to the development of targeted therapies to decrease sperm DNA damage, improved oocyte quality to combat incoming DNA insults or lead to development of methodologies to identify individual spermatozoa without DNA damage.


Assuntos
Dano ao DNA , Reparo do DNA , Idoso , Animais , Dano ao DNA/genética , Reparo do DNA/genética , Desenvolvimento Embrionário/genética , Feminino , Humanos , Masculino , Oócitos/fisiologia , Gravidez , Espermatozoides/fisiologia
9.
Pathol Oncol Res ; 28: 1610401, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36061145

RESUMO

The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING)-mediated senescence-associated secretory phenotype (SASP) pathway has recently been identified in the suppression and promotion of cancers. However, its practical role in carcinogenesis remains to be comprehensively elucidated. Here, we describe an investigation analysing SASP activity and its correlations with DNA damage response (DDR), genomic mutations, and cell proliferation in gastric carcinogenesis among 30 cases with available endoscopic submucosal dissection (ESD) specimens of early neoplastic lesions (including low-grade dysplasia [LGD], high-grade dysplasia [HGD], and intramucosal carcinoma). The positive cells of senescence-associated ß-galactosidase staining and cGAS, STING, interferon-regulatory factor 3 (IRF3), and signal transducer and activator of transcription 6 (STAT6) expression levels using immunostaining were elevated in HGD and in cancers. Similarly, increased expression of the Fanconi anemia group D2 (FANCD2) protein, tumour suppressor p53 binding protein 1 (TP53BP1), and replication protein A (RPA2) (i.e., primary DDR factors) was detected in HGD and in cancers; these increased expression levels were closely correlated with high expression of Ki67 and minichromosome maintenance complex component 7 (MCM7) proteins. Moreover, genomic mutations in TP53 gene were detected in 56.67% of the evaluated cases (17/30) using next-generation sequencing, and positive staining was verified in HGD and in cancers. Statistical analysis revealed that cell proliferation closely correlated with the expression of DDR factors, of which TP53BP1 was positively associated with SASP factors and IRF3 was positively correlated with cell proliferation. In addition, an analysis evaluating clinical features demonstrated that STAT6-positive cases showed a longer progression-free survival time than STAT6-negative cases. Our evaluation, conducted using a limited number of specimens, suggests SASP may be prevalent in early gastric neoplastic lesions and could be activated by accelerated cell proliferation-induced DDR. The clinical significance of SASP still needs to be determined.


Assuntos
Senescência Celular , Neoplasias , Carcinogênese , Proliferação de Células/genética , Senescência Celular/genética , Dano ao DNA/genética , Humanos , Proteínas de Membrana , Nucleotidiltransferases/genética , Nucleotidiltransferases/metabolismo
10.
J Toxicol Environ Health A ; 85(22): 937-951, 2022 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-36068785

RESUMO

Coumarins and chalcones are compounds widely found in plants or obtained by synthetic methods which possess several biological properties including antioxidant, anti-inflammatory, and antitumor effects. A series of coumarin-chalcone hybrids were synthesized to improve their biological actions and reduce potential adverse effects. Considering the applications of these molecules, a coumarin-chalcone hybrid [7-methoxy-3-(E)-3-(3,4,5-trimethoxyphenyl) acryloyl-2 H-chromen-2-one] (4-MET) was synthesized and the genotoxic, cytotoxic, and protective effects assessed against damage induced by different mutagens. First, in silico tools were used to predict biological activity of 4-MET which indicated a chemopreventive potential. Subsequently, the genotoxic/antigenotoxic activities of 4-MET were determined both in vitro (Ames test) and in vivo (micronucleus (MN) test and comet assay). In addition, molecular docking simulations were performed between 4-MET and glutathione reductase, an important cellular detoxifying enzyme. Our results indicated that 4-MET was not mutagenic in the Ames test; however, when co-treated with sodium azide or 4-nitroquinoline 1-oxide (4-NQO), 4-MET significantly reduced the harmful actions of these mutagens. Except for a cytotoxic effect after 120 hr treatment, 4-MET alone did not produce cytotoxicity or genotoxicity in the MN test and comet assay. Nonetheless, all treatments of 4-MET with cyclophosphamide (CPA) showed a chemoprotective effect against DNA damage induced by CPA. Further, molecular docking analysis indicated a strong interaction between 4-MET and the catalytic site of glutathione reductase. These effects may be related to (1) damage prevention, (2) interaction with detoxifying enzymes, and (3) DNA-repair induction. Therefore, data demonstrated that 4-MET presents a favorable profile to be used in chemopreventive therapies.


Assuntos
Chalcona , Chalconas , Chalconas/farmacologia , Ensaio Cometa/métodos , Cumarínicos/farmacologia , Ciclofosfamida , Dano ao DNA , Reparo do DNA , Glutationa Redutase , Testes para Micronúcleos , Simulação de Acoplamento Molecular , Mutagênicos/toxicidade
11.
Cell Commun Signal ; 20(1): 135, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36050770

RESUMO

BACKGROUND: Nuclear hormone receptors are involved in transcriptional regulation and many important cellular processes including development and metabolism. However, its role in DNA damage-induced apoptosis remains elusive. METHODS: Synchronized young adult animals were irradiated with different doses of gamma-Ray, and then put back to culture at 20 °C. Germline cell apoptosis was scored at different time point. RESULTS: Deletion of nhr-14 led to decreased DNA damage-induced germline apoptosis, but not the physiological programmed cell death. We also demonstrate that nhr-14 functions downstream of the DNA damage checkpoint pathway. Moreover, we show that nhr-14 regulates egl-1 and ced-13 transcription upon DNA damage. Mechanistically, NHR-14 forms a complex with CEP-1/p53 and binds directly to the egl-1 promoter to promote egl-1 transcription.. CONCLUSIONS: Our results indicate that NHR-14/HNF4α cooperates with CEP-1/p53 to regulate DNA damage-induced apoptosis. Video abstract.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Apoptose , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Dano ao DNA , Proteína Supressora de Tumor p53/metabolismo
12.
J Exp Clin Cancer Res ; 41(1): 268, 2022 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-36071479

RESUMO

As our understanding of the mechanisms of cancer treatment has increased, a growing number of studies demonstrate pathways through which DNA damage repair (DDR) affects the immune system. At the same time, the varied response of patients to immune checkpoint blockade (ICB) therapy has prompted the discovery of various predictive biomarkers and the study of combination therapy. Here, our investigation explores the interactions involved in combination therapy, accompanied by a review that summarizes currently identified and promising predictors of response to immune checkpoint inhibitors (ICIs) that are useful for classifying oncology patients. In addition, this work, which discusses immunogenicity and several components of the tumor immune microenvironment, serves to illustrate the mechanism by which higher response rates and improved efficacy of DDR inhibitors (DDRi) in combination with ICIs are achieved.


Assuntos
Inibidores de Checkpoint Imunológico , Neoplasias , Dano ao DNA , Reparo do DNA , Humanos , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/metabolismo , Microambiente Tumoral
13.
Molecules ; 27(17)2022 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-36080487

RESUMO

Chlorfenapyr (CHL) is a type of insecticide with a wide range of insecticidal activities and unique targets. The extensive use of pesticides has caused an increase in potential risks to the environment and human health. However, the potential toxicity of CHL and its mechanisms of action on humans remain unclear. Therefore, human liver cells (HepG2) were used to investigate the cytotoxic effect and mechanism of toxicity of CHL at the cellular level. The results showed that CHL induced cellular toxicity in HepG2 cells and induced mitochondrial damage associated with reactive oxygen species (ROS) accumulation and mitochondrial calcium overload, ultimately leading to apoptosis and autophagy in HepG2 cells. Typical apoptotic changes occurred, including a decline in the mitochondrial membrane potential, the promotion of Bax/Bcl-2 expression causing the release of cyt-c into the cytosol, the activation of cas-9/-3, and the cleavage of PARP. The autophagic effects included the formation of autophagic vacuoles, accumulation of Beclin-1, transformation of LC3-II, and downregulation of p62. Additionally, DNA damage and cell cycle arrest were detected in CHL-treated cells. These results show that CHL induced cytotoxicity associated with mitochondria-mediated programmed cell death (PCD) and DNA damage in HepG2 cells.


Assuntos
Apoptose , Mitocôndrias , Autofagia , Dano ao DNA , Células Hep G2 , Humanos , Potencial da Membrana Mitocondrial , Mitocôndrias/metabolismo , Piretrinas , Espécies Reativas de Oxigênio/metabolismo
14.
Artigo em Chinês | MEDLINE | ID: mdl-36052584

RESUMO

Objective: To investigate the protective effect of diallyl sulfide (DAS) , against benzene-induced genetic damage in rat. Methods: In September 2018, Sixty adult male adaptive feeding 5 days, were randomly divided into six groups according to their weight. Control groups, DAS control groups, benzene model groups, benzene+low DAS groups, benzene+middle DAS groups, benzene+High DAS group, 10 in each group. Rats in the DAS and DAS control group were orally given DAS at 40, 80, 160, 160 mg/kg, blank control and benzene model groups were given corn oil in the same volume. 2 h later, the rats in the benzene model and DAS treatment groups were given gavage administration of benzene (1.3 g/kg) mixed with corn oil (50%, V/V) , blank and DAS control groups were given corn oil in the same volume. Once a day, for 4 weeks. Samples were collected for subsequent testing. Results: Compared with the blank control group, In benzene treated rat, peripheral WBC count was reduced 65.06% (P=0.003) , lymphocyte ratiowas reduced (P=0.000) , micronucleus rate was increased (P=0.000) , Mean fluorescent intensity and relative fluorescence intensity of γH2AX in BMCs were increased 32.69%、32.64% (P=0.001、0.008) , Mean fluorescent intensity and relative fluorescence intensity of γH2AX in PBLs were increased 397.70%、396.26% (P=0.000、P=0.003) respectively. Compared with the benzene model group, the WBC count increased respectively (P=0.000、0.003、0.006) and the micronucleus rate decreased (P=0.000、0.000、0.000) in the DAS groups, Mean fluorescent intensity and relative fluorescence intensity ofγH2AX in BMCs were significantly reduced in the high DAS groups (P=0.000、0.000) , Mean fluorescent intensity and relative fluorescence intensity ofγH2AX in PBLs were significantly reduced in the low, middle, high DAS groups (P=0.000、0.000) . Conclusion: DAS can effectively suppress benzene induced genotoxic damage in rats.


Assuntos
Compostos Alílicos , Benzeno , Ácido 4-Acetamido-4'-isotiocianatostilbeno-2,2'-dissulfônico/análogos & derivados , Compostos Alílicos/farmacologia , Animais , Benzeno/toxicidade , Óleo de Milho , Dano ao DNA , Masculino , Ratos , Sulfetos/farmacologia
15.
Int J Mol Sci ; 23(17)2022 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-36077022

RESUMO

DNA damage in early-stage embryos impacts development and is a risk factor for segregation of altered genomes. DNA damage response (DDR) encompasses a sophisticated network of proteins involved in sensing, signaling, and repairing damage. DDR is regulated by reversible post-translational modifications including acetylation, methylation, phosphorylation, ubiquitylation, and SUMOylation. While important regulators of these processes have been characterized in somatic cells, their roles in early-stage embryos remain broadly unknown. The objective of this study was to explore how ubiquitylation and SUMOylation are involved in the regulation of early development in porcine embryos by assessing the mRNA profile of genes encoding ubiquitination (UBs), deubiquitination (DUBs), SUMOylation (SUMOs) or deSUMOylation (deSUMOs) enzymes in oocyte and embryos at different stages of development, and to evaluate if the induction of DNA damage at different stages of embryo development would alter the mRNA abundance of these genes. Pig embryos were produced by in vitro fertilization and DNA damage was induced by ultraviolet (UV) light exposure for 10 s on days 2, 4 or 7 of development. The relative mRNA abundance of most UBs, DUBs, SUMOs, and deSUMOs was higher in oocytes and early-stage embryos than in blastocysts. Transcript levels for UBs (RNF20, RNF40, RNF114, RNF169, CUL5, DCAF2, DECAF13, and DDB1), DUBs (USP16), and SUMOs (CBX4, UBA2 and UBC9), were upregulated in early-stage embryos (D2 and/or D4) compared to oocytes and blastocysts. In response to UV-induced DNA damage, transcript levels of several UBs, DUBs, SUMOs, and deSUMOs decreased in D2 and D4 embryos, but increased in blastocysts. These findings revealed that transcript levels of genes encoding for important UBs, DUBs, SUMOs, and deSUMOs are regulated during early embryo development and are modulated in response to induced DNA damage. This study has also identified candidate genes controlling post-translational modifications that may have relevant roles in the regulation of normal embryo development, repair of damaged DNA, and preservation of genome stability in the pig embryo.


Assuntos
Blastocisto , Ubiquitina , Animais , Blastocisto/metabolismo , Dano ao DNA , Desenvolvimento Embrionário/genética , Oócitos/fisiologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Suínos , Ubiquitina/metabolismo
16.
Int J Mol Sci ; 23(17)2022 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-36077176

RESUMO

In response to DNA damage, cells have developed a sophisticated signaling pathway, consisting of DNA damage sensors, transducers, and effectors, to ensure efficient and proper repair of damaged DNA. During this process, posttranslational modifications (PTMs) are central events that modulate the recruitment, dissociation, and activation of DNA repair proteins at damage sites. Emerging evidence reveals that protein arginine methylation is one of the common PTMs and plays critical roles in DNA damage response. Protein arginine methyltransferases (PRMTs) either directly methylate DNA repair proteins or deposit methylation marks on histones to regulate their transcription, RNA splicing, protein stability, interaction with partners, enzymatic activities, and localization. In this review, we summarize the substrates and roles of each PRMTs in DNA damage response and discuss the synergistic anticancer effects of PRMTs and DNA damage pathway inhibitors, providing insight into the significance of arginine methylation in the maintenance of genome integrity and cancer therapies.


Assuntos
Histonas , Proteína-Arginina N-Metiltransferases , Arginina/metabolismo , Dano ao DNA , Histonas/metabolismo , Metilação , Processamento de Proteína Pós-Traducional , Proteína-Arginina N-Metiltransferases/genética , Proteína-Arginina N-Metiltransferases/metabolismo
17.
Proc Natl Acad Sci U S A ; 119(37): e2205201119, 2022 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-36067283

RESUMO

P53 is a widely studied tumor suppressor that plays important roles in cell-cycle regulation, cell death, and DNA damage repair. P53 is found throughout metazoans, even in invertebrates that do not develop malignancies. The prevailing theory for why these invertebrates possess a tumor suppressor is that P53 originally evolved to protect the germline of early metazoans from genotoxic stress such as ultraviolet radiation. This theory is largely based upon functional data from only three invertebrates, omitting important groups of animals including flatworms. Previous studies in the freshwater planarian flatworm Schmidtea mediterranea suggested that flatworm P53 plays an important role in stem cell maintenance and skin production, but these studies did not directly test for any tumor suppressor functions. To better understand the function of P53 homologs across diverse flatworms, we examined the function of two different P53 homologs in the parasitic flatworm Schistosoma mansoni. The first P53 homolog (p53-1) is orthologous to S. mediterranea P53(Smed-p53) and human TP53 and regulates flatworm stem cell maintenance and skin production. The second P53 homolog (p53-2) is a parasite-specific paralog that is conserved across parasitic flatworms and is required for the normal response to genotoxic stress in S. mansoni. We then found that Smed-p53 does not seem to play any role in the planarian response to genotoxic stress. The existence of this parasite-specific paralog that bears a tumor suppressor-like function in parasitic flatworms implies that the ability to respond to genotoxic stress in parasitic flatworms may have arisen from convergent evolution.


Assuntos
Evolução Biológica , Dano ao DNA , Planárias , Proteína Supressora de Tumor p53 , Animais , Humanos , Planárias/genética , Planárias/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Raios Ultravioleta
18.
Int J Mol Sci ; 23(17)2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36077459

RESUMO

Liver kinase B1 (LKB1) is a serine/threonine protein kinase that acts as a key tumor suppressor protein by activating its downstream kinases, such as AMP-activated protein kinase (AMPK). However, the regulatory actions of LKB1 and AMPK on DNA damage response (DDR) remain to be explored. In this study, we investigated the function of LKB1 in DDR induced by cisplatin, a representative DNA-damaging agent, and found that LKB1 stabilizes and activates p53 through the c-Jun N-terminal kinase (JNK) pathway, which promotes cisplatin-induced apoptosis in human fibrosarcoma cell line HT1080. On the other hand, we found that AMPKα1 and α2 double knockout (DKO) cells showed enhanced stabilization of p53 and increased susceptibility to apoptosis induced by cisplatin, suggesting that AMPK negatively regulates cisplatin-induced apoptosis. Moreover, the additional stabilization of p53 and subsequent apoptosis in AMPK DKO cells were clearly canceled by the treatment with the antioxidants, raising the possibility that AMPK suppresses the p53 activation mediated by oxidative stress. Thus, our findings unexpectedly demonstrate the reciprocal regulation of p53 by LKB1 and AMPK in DDR, which provides insights into the molecular mechanisms of DDR.


Assuntos
Quinases Proteína-Quinases Ativadas por AMP , Proteínas Quinases Ativadas por AMP , Cisplatino , Dano ao DNA , Quinases Proteína-Quinases Ativadas por AMP/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Apoptose , Linhagem Celular Tumoral , Cisplatino/metabolismo , Cisplatino/farmacologia , Humanos , Fosforilação , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
19.
Invest Ophthalmol Vis Sci ; 63(10): 7, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36094642

RESUMO

Purpose: Age-related macular degeneration (AMD) is currently the leading cause of blindness worldwide. Previously, we identified ubiquitin-protein ligase E3D (UBE3D) as an AMD-associated protein for East Asian populations, and here we further demonstrate that UBE3D could be associated with DNA damage response. Methods: The established I-SceI-inducible GFP reporter system was used to explore the effect of UBE3D on homologous recombination. Immunoprecipitation-mass spectrometry (MS) was used to explore potential UBE3D-interacting proteins and validated with coimmunoprecipitation assays and the pulldown assays. Micrococcal nuclease (MNase) assays were used to investigate the function of UBE3D on heterochromatin de-condensation upon DNA damage. An aged mouse model of blue light-induced eye damage was constructed, and electroretinography (ERG) and optical coherence tomography (OCT) were performed to compare the differences between wild-type and UBE3D+/- mice. Results: First, we show that GFP-UBE3D is recruited to damage sites by PCNA, through a PCNA-interacting protein (PIP) box. Furthermore, UBE3D interacts with KAP1 via R377R378 and oxidation of the AMD-associated V379M mutation abolishes KAP1-UBE3D binding. By MNase assays, UBE3D depletion reduces the chromatin relaxation levels upon DNA damage. In addition, UBE3D depletion renders less KAP1 recruitment. Compared with wild type, blue light induces less damage in UBE3D+/- mice as measured by ERG and OCT, consistent with our biochemical results. Conclusions: Hence, we propose that one potential mechanism that UBE3D-V379M contributes to AMD pathogenesis might be via defective DNA damage repair linked with oxidative stress and our results offered a potential direction for the treatment of AMD.


Assuntos
Degeneração Macular , Animais , Dano ao DNA , Eletrorretinografia , Luz , Degeneração Macular/genética , Camundongos , Antígeno Nuclear de Célula em Proliferação/genética
20.
Oncoimmunology ; 11(1): 2117321, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36117525

RESUMO

The concept of exploiting tumor intrinsic deficiencies in DNA damage repair mechanisms by inhibiting compensatory DNA repair pathways is well established. For example, ATM-deficient cells show increased sensitivity to the ATR inhibitor ceralasertib. DNA damage response (DDR)-deficient cells are also more sensitive to DNA damaging agents like the DNA crosslinker pyrrolobenzodiazepine (PBD) SG-3199. However, additional antitumor benefits from targeting the DDR pathways, which could operate through the activation of the innate immune system are less well studied. DNA accumulation in the cytosol acts as an immunogenic danger signal, inducing the expression of type-I interferon (IFN) stimulated genes (ISGs) by the activation of the cGAS-STING pathway. Here, we demonstrate that ATM -/- FaDu tumor cells have higher basal expression of ISGs when compared to WT cells and respond to ceralasertib and PBD SG-3199 by inducing higher levels of ISGs in a cGAS-STING-dependent manner. We show that sensitive tumor cells treated with ceralasertib and PBD SG-3199 activate dendritic cells (DCs) via a type-I IFN-dependent mechanism. However, STING deficiency in tumor cells does not prevent DC activation, suggesting that transactivation of the STING pathway occurs within DCs. Furthermore, depletion of the cytosolic DNA exonuclease TREX1 in tumor cells increases DC activation in response to PBD SG-3199-treated tumor cells, indicating that an increase in tumor-derived cytosolic DNA may further enhance DC activation. In summary, in this study, we show that ceralasertib and PBD SG-3199 treatment not only intrinsically target tumor cells but also extrinsically increase tumor cell immunogenicity by inducing DC activation, which is enhanced in ATM-deficient cells.


Assuntos
Interferon Tipo I , Neoplasias , DNA , Dano ao DNA , Células Dendríticas/metabolismo , Exodesoxirribonucleases , Indóis , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Morfolinas , Neoplasias/genética , Nucleotidiltransferases/genética , Nucleotidiltransferases/metabolismo , Pirimidinas , Sulfonamidas
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