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1.
Nutrients ; 13(8)2021 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-34444947

RESUMO

Chronic obstructive pulmonary disease (COPD) is a respiratory disease associated with airways inflammation and lung parenchyma fibrosis. The primary goals of COPD treatment are to reduce symptoms and risk of exacerbations, therefore pulmonary rehabilitation is considered the key component of managing COPD patients. Oxidative airway damage, inflammation and reduction of endogenous antioxidant enzymes are known to play a crucial role in the pathogenesis of COPD. Recently, also natural antioxidants have been considered as they play an important role in metabolism, DNA repair and fighting the effects of oxidative stress. In this paper we evaluated the response of 105 elderly COPD patients to pulmonary rehabilitation (PR), based on high or low vegetable consumption, by analyzing clinical parameters and biological measurements at baseline and after completion of the three weeks PR. We found that daily vegetable intake in normal diet, without any specific intervention, can increase the probability to successfully respond to rehabilitation (65.4% of responders ate vegetables daily vs. 40.0% of non-responders, p = 0.033). The association was especially evident in subjects ≥ 80 year of age (OR = 17.0; p < 0.019). Three weeks of pulmonary rehabilitation are probably too short to reveal a reduction of the oxidative stress and DNA damage, but are enough to show an improvement in the patient's inflammatory state.


Assuntos
Dieta Saudável/métodos , Ingestão de Alimentos/fisiologia , Fenômenos Fisiológicos da Nutrição do Idoso/fisiologia , Doença Pulmonar Obstrutiva Crônica/reabilitação , Verduras , Administração por Inalação , Corticosteroides/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Broncodilatadores/administração & dosagem , Dano ao DNA/fisiologia , Inquéritos sobre Dietas , Feminino , Humanos , Inflamação , Pulmão/metabolismo , Masculino , Estresse Oxidativo/fisiologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Resultado do Tratamento
2.
Viruses ; 13(7)2021 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-34372559

RESUMO

The human BK polyomavirus (BKPyV) is latent in the kidneys of most adults, but can be reactivated in immunosuppressed states, such as following renal transplantation. If left unchecked, BK polyomavirus nephropathy (PyVAN) and possible graft loss may result from viral destruction of tubular epithelial cells and interstitial fibrosis. When coupled with regular post-transplant screening, immunosuppression reduction has been effective in limiting BKPyV viremia and the development of PyVAN. Antiviral drugs that are safe and effective in combating BKPyV have not been identified but would be a benefit in complementing or replacing immunosuppression reduction. The present study explores inhibition of the host DNA damage response (DDR) as an antiviral strategy. Immunohistochemical and immunofluorescent analyses of PyVAN biopsies provide evidence for stimulation of a DDR in vivo. DDR pathways were also stimulated in vitro following BKPyV infection of low-passage human renal proximal tubule epithelial cells. The role of Chk1, a protein kinase known to be involved in the replication stress-induced DDR, was examined by inhibition with the small molecule LY2603618 and by siRNA-mediated knockdown. Inhibition of Chk1 resulted in decreased replication of BKPyV DNA and viral spread. Activation of mitotic pathways was associated with the reduction in BKPyV replication. Chk1 inhibitors that are found to be safe and effective in clinical trials for cancer should also be evaluated for antiviral activity against BKPyV.


Assuntos
Vírus BK/genética , Quinase 1 do Ponto de Checagem/metabolismo , Infecções por Polyomavirus/tratamento farmacológico , Vírus BK/patogenicidade , Células Cultivadas , Quinase 1 do Ponto de Checagem/fisiologia , Dano ao DNA/fisiologia , Reparo do DNA/fisiologia , Humanos , Rim/patologia , Rim/virologia , Transplante de Rim , Compostos de Fenilureia/farmacologia , Infecções por Polyomavirus/genética , Infecções por Polyomavirus/imunologia , Pirazinas/farmacologia , Infecções Tumorais por Vírus/tratamento farmacológico , Infecções Tumorais por Vírus/genética , Replicação Viral/efeitos dos fármacos , Replicação Viral/fisiologia
3.
Mol Cell Biol ; 41(10): e0008121, 2021 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-34251884

RESUMO

Cullin-4 ubiquitin ligase (CRL4) complexes are differentially composed and highly dynamic protein assemblies that control many biological processes, including the global genome nucleotide excision repair (GG-NER) pathway. Here, we identified the kinase mitogen-activated protein kinase kinase kinase 1 (MEKK1) as a novel constitutive interactor of a cytosolic CRL4 complex that disassembles after DNA damage due to the caspase-mediated cleavage of MEKK1. The kinase activity of MEKK1 was important to trigger autoubiquitination of the CRL4 complex by K48- and K63-linked ubiquitin chains. MEKK1 knockdown prohibited DNA damage-induced degradation of the CRL4 component DNA-damage binding protein 2 (DDB2) and the CRL4 substrate p21 and also cell recovery and survival. A ubiquitin replacement strategy revealed a contribution of K63-branched ubiquitin chains for DNA damage-induced DDB2/p21 decay, cell cycle regulation, and cell survival. These data might also have implications for cancer, as frequently occurring mutations of MEKK1 might have an impact on genome stability and the therapeutic efficacy of CRL4-dependent immunomodulatory drugs such as thalidomide derivatives.


Assuntos
Reparo do DNA/fisiologia , MAP Quinase Quinase Quinase 1/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Pontos de Checagem do Ciclo Celular , Linhagem Celular Tumoral , Sobrevivência Celular , Inibidor de Quinase Dependente de Ciclina p21/genética , DNA/química , Dano ao DNA/fisiologia , Reparo do DNA/genética , Proteínas de Ligação a DNA/metabolismo , Células HEK293 , Células HeLa , Humanos , MAP Quinase Quinase Quinase 1/genética , Proteínas Nucleares/metabolismo , Ubiquitina-Proteína Ligases/fisiologia , Ubiquitinação
4.
Artigo em Inglês | MEDLINE | ID: mdl-34266626

RESUMO

Nucleotide excision repair (NER) is the main pathway to repair bulky DNA damages including pyrimidine dimers, and the genetic dysregulation of NER associated proteins is well known to cause diseases such as cancer and neurological disorder. Other than the genetic defects, 'external factors' such as oxidative stress and environmental chemicals also affect NER. In this study, we examined the impact of extracellular pH on NER. We prepared the culture media, whose pH values are 8.4 (normal condition), 7.6, 6.6 and 6.2 under atmospheric CO2 conditions. Human keratinocytes, HaCaT, slightly died after 48 h incubation in DMEM at pH 8.4, 7.6 and 6.6, while in pH 6.2 condition, marked cell death was induced. UV-induced pyrimidine dimers, pyrimidine (6-4) pyrimidone photoproducts (6-4PPs) and cyclobutane pyrimidine dimers (CPDs), were effectively repaired at 60 min and 24 h, respectively, which were remarkably inhibited at pH 6.6 and 6.2. The associated repair molecule, TFIIH, was accumulated to the damaged sites 5 min after UVC irradiation in all pH conditions, but the release was delayed as the pH got lower. Furthermore, accumulation of XPG at 5 min was delayed at pH 6.2 and 6.6, and the release at 60 min was completely suppressed. At the low pH, the DNA synthesis at the gaps created by incision of oligonucleotides containing pyrimidine dimers was significantly delayed. In this study, we found that the low extracellular pH inhibited NER pathway. This might partially contribute to carcinogenesis in inflamed tissues, which exhibit acidic pH.


Assuntos
Reparo do DNA/genética , Morte Celular/genética , Morte Celular/fisiologia , Células Cultivadas , Dano ao DNA/genética , Dano ao DNA/fisiologia , Replicação do DNA/genética , Replicação do DNA/fisiologia , Fibroblastos/fisiologia , Humanos , Concentração de Íons de Hidrogênio , Queratinócitos/efeitos dos fármacos , Queratinócitos/fisiologia , Dímeros de Pirimidina/genética , Raios Ultravioleta/efeitos adversos
5.
Molecules ; 26(12)2021 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-34205449

RESUMO

Restriction endonucleases (REs) are intra-bacterial scissors that are considered tools in the fight against foreign genetic material. SspI and BsmAI, examined in this study, cleave dsDNA at their site of recognition or within a short distance of it. Both enzymes are representatives of type II REs, which have played an extremely important role in research on the genetics of organisms and molecular biology. Therefore, the study of agents affecting their activity has become highly important. Ionizing radiation may damage basic cellular mechanisms by inducing lesions in the genome, with 5',8-cyclo-2'-deoxypurines (cdPus) as a model example. Since cdPus may become components of clustered DNA lesions (CDLs), which are unfavorable for DNA repair pathways, their impact on other cellular mechanisms is worthy of attention. This study investigated the influence of cdPus on the elements of the bacterial restriction-modification system. In this study, it was shown that cdPus present in DNA affect the activity of REs. SspI was blocked by any cdPu lesion present at the enzyme's recognition site. When lesions were placed near the recognition sequence, the SspI was inhibited up to 46%. Moreover, (5'S)-5',8-cyclo-2'-deoxyadenosine (ScdA) present in the oligonucleotide sequence lowered BsmAI activity more than (5'R)-5',8-cyclo-2'-deoxyadenosine (RcdA). Interestingly, in the case of 5',8-cyclo-2'-deoxyguanosine (cdG), both 5'S and 5'R diastereomers inhibited BsmAI activity (up to 55% more than cdA). The inhibition was weaker when cdG was present at the recognition site rather than the cleavage site.


Assuntos
Enzimas de Restrição do DNA/metabolismo , DNA/metabolismo , Desoxiadenosinas/metabolismo , Desoxiguanosina/metabolismo , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Animais , Dano ao DNA/fisiologia , Reparo do DNA/fisiologia , Humanos , Oligonucleotídeos/metabolismo
6.
Int J Mol Sci ; 22(13)2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-34203408

RESUMO

TENT4A (PAPD7) is a non-canonical poly(A) polymerase, of which little is known. Here, we show that TENT4A regulates multiple biological pathways and focuses on its multilayer regulation of translesion DNA synthesis (TLS), in which error-prone DNA polymerases bypass unrepaired DNA lesions. We show that TENT4A regulates mRNA stability and/or translation of DNA polymerase η and RAD18 E3 ligase, which guides the polymerase to replication stalling sites and monoubiquitinates PCNA, thereby enabling recruitment of error-prone DNA polymerases to damaged DNA sites. Remarkably, in addition to the effect on RAD18 mRNA stability via controlling its poly(A) tail, TENT4A indirectly regulates RAD18 via the tumor suppressor CYLD and via the long non-coding antisense RNA PAXIP1-AS2, which had no known function. Knocking down the expression of TENT4A or CYLD, or overexpression of PAXIP1-AS2 led each to reduced amounts of the RAD18 protein and DNA polymerase η, leading to reduced TLS, highlighting PAXIP1-AS2 as a new TLS regulator. Bioinformatics analysis revealed that TLS error-prone DNA polymerase genes and their TENT4A-related regulators are frequently mutated in endometrial cancer genomes, suggesting that TLS is dysregulated in this cancer.


Assuntos
Proteínas Cromossômicas não Histona/metabolismo , Reparo do DNA/fisiologia , DNA Polimerase Dirigida por DNA/metabolismo , Neoplasias do Endométrio/metabolismo , Mutação/genética , Polinucleotídeo Adenililtransferase/metabolismo , RNA Mensageiro/metabolismo , Western Blotting , Linhagem Celular Tumoral , Proteínas Cromossômicas não Histona/genética , Biologia Computacional , Dano ao DNA/genética , Dano ao DNA/fisiologia , Reparo do DNA/genética , Replicação do DNA/genética , Replicação do DNA/fisiologia , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , DNA Polimerase Dirigida por DNA/genética , Neoplasias do Endométrio/genética , Feminino , Células HEK293 , Humanos , Imunoprecipitação , Células MCF-7 , Reação em Cadeia da Polimerase , Polinucleotídeo Adenililtransferase/genética , Estabilidade de RNA/genética , Estabilidade de RNA/fisiologia , RNA Mensageiro/genética , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação/genética , Ubiquitinação/fisiologia
7.
Int J Mol Sci ; 22(14)2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34298882

RESUMO

Platelets can modulate cancer through budding of platelet microparticles (PMPs) that can transfer a plethora of bioactive molecules to cancer cells upon internalization. In acute myelogenous leukemia (AML) this can induce chemoresistance, partially through a decrease in cell activity. Here we investigated if the internalization of PMPs protected the monocytic AML cell line, THP-1, from apoptosis by decreasing the initial cellular damage inflicted by treatment with daunorubicin, or via direct modulation of the apoptotic response. We examined whether PMPs could protect against apoptosis after treatment with a selection of inducers, primarily associated with either the intrinsic or the extrinsic apoptotic pathway, and protection was restricted to the agents targeting intrinsic apoptosis. Furthermore, levels of daunorubicin-induced DNA damage, assessed by measuring gH2AX, were reduced in both 2N and 4N cells after PMP co-incubation. Measuring different BCL2-family proteins before and after treatment with daunorubicin revealed that PMPs downregulated the pro-apoptotic PUMA protein. Thus, our findings indicated that PMPs may protect AML cells against apoptosis by reducing DNA damage both dependent and independent of cell cycle phase, and via direct modulation of the intrinsic apoptotic pathway by downregulating PUMA. These findings further support the clinical relevance of platelets and PMPs in AML.


Assuntos
Apoptose/fisiologia , Micropartículas Derivadas de Células/fisiologia , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/fisiologia , Daunorrubicina/farmacologia , Células THP-1/fisiologia , Apoptose/efeitos dos fármacos , Plaquetas , Micropartículas Derivadas de Células/efeitos dos fármacos , Micropartículas Derivadas de Células/metabolismo , Células Cultivadas , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/fisiologia , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Células THP-1/efeitos dos fármacos , Células THP-1/metabolismo
8.
Int J Mol Sci ; 22(13)2021 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-34281248

RESUMO

Age-related macular degeneration (AMD), the main cause of vision loss in the elderly, is associated with oxidation in the retina cells promoting telomere attrition. Activation of telomerase was reported to improve macular functions in AMD patients. The catalytic subunit of human telomerase (hTERT) may directly interact with proteins important for senescence, DNA damage response, and autophagy, which are impaired in AMD. hTERT interaction with mTORC1 (mTOR (mechanistic target of rapamycin) complex 1) and PINK1 (PTEN-induced kinase 1) activates macroautophagy and mitophagy, respectively, and removes cellular debris accumulated over AMD progression. Ectopic expression of telomerase in retinal pigment epithelium (RPE) cells lengthened telomeres, reduced senescence, and extended their lifespan. These effects provide evidence for the potential of telomerase in AMD therapy. Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) may be involved in AMD pathogenesis through decreasing oxidative stress and senescence, regulation of vascular endothelial growth factor (VEGF), and improving autophagy. PGC-1α and TERT form an inhibitory positive feedback loop. In conclusion, telomerase activation and its ectopic expression in RPE cells, as well as controlled clinical trials on the effects of telomerase activation in AMD patients, are justified and should be assisted by PGC-1α modulators to increase the therapeutic potential of telomerase in AMD.


Assuntos
Degeneração Macular/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Telomerase/metabolismo , Envelhecimento/metabolismo , Autofagia/fisiologia , Dano ao DNA/fisiologia , Reparo do DNA/fisiologia , Humanos , Degeneração Macular/fisiopatologia , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Mitocôndrias/metabolismo , Estresse Oxidativo/fisiologia , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/fisiologia , Fenótipo , Espécies Reativas de Oxigênio/metabolismo , Epitélio Pigmentado da Retina/metabolismo , Transdução de Sinais , Telomerase/fisiologia , Telômero/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo
9.
Mutat Res Rev Mutat Res ; 787: 108371, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34083035

RESUMO

The alkaline comet assay, or single cell gel electrophoresis, is one of the most popular methods for assessing DNA damage in human population. One of the open issues concerning this assay is the identification of those factors that can explain the large inter-individual and inter-laboratory variation. International collaborative initiatives such as the hCOMET project - a COST Action launched in 2016 - represent a valuable tool to meet this challenge. The aims of hCOMET were to establish reference values for the level of DNA damage in humans, to investigate the effect of host factors, lifestyle and exposure to genotoxic agents, and to compare different sources of assay variability. A database of 19,320 subjects was generated, pooling data from 105 studies run by 44 laboratories in 26 countries between 1999 and 2019. A mixed random effect log-linear model, in parallel with a classic meta-analysis, was applied to take into account the extensive heterogeneity of data, due to descriptor, specimen and protocol variability. As a result of this analysis interquartile intervals of DNA strand breaks (which includes alkali-labile sites) were reported for tail intensity, tail length, and tail moment (comet assay descriptors). A small variation by age was reported in some datasets, suggesting higher DNA damage in oldest age-classes, while no effect could be shown for sex or smoking habit, although the lack of data on heavy smokers has still to be considered. Finally, highly significant differences in DNA damage were found for most exposures investigated in specific studies. In conclusion, these data, which confirm that DNA damage measured by the comet assay is an excellent biomarker of exposure in several conditions, may contribute to improving the quality of study design and to the standardization of results of the comet assay in human populations.


Assuntos
Ensaio Cometa/métodos , Biomarcadores/sangue , Dano ao DNA/genética , Dano ao DNA/fisiologia , Humanos
10.
PLoS Pathog ; 17(6): e1009596, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34061905

RESUMO

The rapid evolution of RNA viruses has been long considered to result from a combination of high copying error frequencies during RNA replication, short generation times and the consequent extensive fixation of neutral or adaptive changes over short periods. While both the identities and sites of mutations are typically modelled as being random, recent investigations of sequence diversity of SARS coronavirus 2 (SARS-CoV-2) have identified a preponderance of C->U transitions, proposed to be driven by an APOBEC-like RNA editing process. The current study investigated whether this phenomenon could be observed in datasets of other RNA viruses. Using a 5% divergence filter to infer directionality, 18 from 36 datasets of aligned coding region sequences from a diverse range of mammalian RNA viruses (including Picornaviridae, Flaviviridae, Matonaviridae, Caliciviridae and Coronaviridae) showed a >2-fold base composition normalised excess of C->U transitions compared to U->C (range 2.1x-7.5x), with a consistently observed favoured 5' U upstream context. The presence of genome scale RNA secondary structure (GORS) was the only other genomic or structural parameter significantly associated with C->U/U->C transition asymmetries by multivariable analysis (ANOVA), potentially reflecting RNA structure dependence of sites targeted for C->U mutations. Using the association index metric, C->U changes were specifically over-represented at phylogenetically uninformative sites, potentially paralleling extensive homoplasy of this transition reported in SARS-CoV-2. Although mechanisms remain to be functionally characterised, excess C->U substitutions accounted for 11-14% of standing sequence variability of structured viruses and may therefore represent a potent driver of their sequence diversification and longer-term evolution.


Assuntos
Mamíferos/virologia , Mutação , Vírus de RNA/genética , SARS-CoV-2/genética , Desaminases APOBEC/metabolismo , Animais , Sequência de Bases , COVID-19/virologia , Citidina/genética , Dano ao DNA/fisiologia , Evolução Molecular , Regulação Viral da Expressão Gênica , Genoma Viral , Interações Hospedeiro-Patógeno/genética , Humanos , Conformação de Ácido Nucleico , Filogenia , Edição de RNA/fisiologia , Vírus de RNA/classificação , RNA Viral/química , RNA Viral/genética , SARS-CoV-2/química , SARS-CoV-2/classificação , Análise de Sequência de RNA , Transcrição Genética/genética , Uridina/genética
11.
Mutat Res Rev Mutat Res ; 787: 108367, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34083034

RESUMO

Chronic diseases such as cardiovascular diseases, type 2 diabetes or cancer are the global leading cause of mortality. Lifestyle interventions are most effective in reducing metabolic risk factors, disease progression or even side effects of a disease. They are also contributing to decelerate the aging process. Genome instability is very often associated with aging or the above-mentioned diseases, and triggered by inflammation and oxidative stress. An established method to measure chromosomal damage is the cytokinesis block micronucleus (CBMN) cytome assay. The aim of this review and meta-analysis is to collect and analyse the current literature regarding the effects of a lifestyle based (dietary) intervention on changes of micronuclei (MNi), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) in elderly subjects or people diagnosed with diabetes, metabolic disorders, cardiovascular disease, cancer or micronutrient deficiency. Although the main important diseases were considered as well as the large topic of aging, the number and methodological quality in terms of samples size, duration and rationale of the intervention or an inclusion of a control group of available intervention studies with these backgrounds was low. Most of the studies used antioxidant vitamins or folate, few investigated the whole diet. Only one study showed a physical activity intervention approach. The interventions did not lead to decreased genomic marker despite a few cancer related studies, where particularly MN frequency in mucosa lesions and leukoplakia was reduced by green tea and antioxidants. The performed meta-analysis of the available RCTs did not show a significant reduction of MNi, NBUDs or NPBs of most of the interventions performed, except for green tea. Data show in general a lack of an appropriate number of sound lifestyle based intervention studies linking cytogenetic damage and chronic diseases.


Assuntos
Doenças Cardiovasculares/metabolismo , Diabetes Mellitus/metabolismo , Doenças Metabólicas/metabolismo , Doenças Cardiovasculares/genética , Dano ao DNA/genética , Dano ao DNA/fisiologia , Diabetes Mellitus/genética , Humanos , Doenças Metabólicas/genética , Testes para Micronúcleos , Neoplasias/genética , Neoplasias/metabolismo
12.
Mutat Res Rev Mutat Res ; 787: 108346, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34083038

RESUMO

DNA replication stress is a major source of DNA damage, including double-stranded breaks that promote DNA damage response (DDR) signaling. Inefficient repair of such lesions can affect genome integrity. During DNA replication different factors act on chromatin remodeling in a coordinated way. While recent studies have highlighted individual molecular mechanisms of interaction, less is known about the orchestration of chromatin changes under replication stress. In this review we attempt to explore the complex relationship between DNA replication stress, DDR and genome integrity in mammalian cells, taking into account the role of chromatin disposition as an important modulator of DNA repair. Recent data on chromatin restoration and epigenetic re-establishment after DNA replication stress are reviewed.


Assuntos
Dano ao DNA/fisiologia , Replicação do DNA/fisiologia , Instabilidade Genômica/fisiologia , Animais , Cromatina/metabolismo , Montagem e Desmontagem da Cromatina/genética , Montagem e Desmontagem da Cromatina/fisiologia , Dano ao DNA/genética , Replicação do DNA/genética , Instabilidade Genômica/genética , Humanos
13.
Mutat Res Rev Mutat Res ; 787: 108349, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34083037

RESUMO

About 40 million workers are occupationally exposed to crystalline silica (CS) which was classified as a human carcinogen by the IARC. It is assumed that damage of the genetic material via inflammation and reactive oxygen species by CS lead to formation of malignant cells. We conducted a systematic literature search to find out if inhalation of CS containing dusts at workplaces causes damage of the genetic material. Thirteen studies were found eligible for this review, in most of them (n = 9) micronuclei (MN) which reflect structural/numerical chromosomal aberrations were monitored in lymphocytes and/or in exfoliated buccal cells. In 5 investigations DNA damage was measured in blood cells in single cell gel electrophoresis (comet) experiments. Frequently studied groups were potters, stone cutters, miners and construction workers. Results of meta-analyses show that exposure to CS causes formation of MN and DNA breaks, the overall ratio values were in exposed workers 2.06- and 1.96-fold higher than in controls, respectively. Two studies reported increased levels of oxidized guanine, and higher levels of DNA adducts with malondialdehyde indicating that exposure to CS leads to oxidative damage. The exposure of the workers to CS was quantified only in two studies, information concerning the size and chemical structures of the particles is lacking in most investigations. Therefore, it is not possible to use the results to derive occupational exposure limits of workers to CS which vary strongly in different countries. Nevertheless, the evaluation of the current state of knowledge shows that biomonitoring studies in which damage of the genetic material is measured in CS exposed workers can contribute to assess adverse health effects as consequence of DNA instability in specific occupations.


Assuntos
Ensaio Cometa/métodos , Dano ao DNA/fisiologia , Dano ao DNA/genética , Micronúcleos com Defeito Cromossômico , Dióxido de Silício/química
14.
Mutat Res Rev Mutat Res ; 787: 108376, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34083040

RESUMO

Aurora Kinase B (AURKB) and Mitotic Arrest Deficient 2 Like 2 (MAD2L2) are emerging anticancer therapeutic targets. AURKB and MAD2L2 are the least well studied members of their protein families, compared to AURKA and MAD2L1. Both AURKB and MAD2L2 play a critical role in mitosis, cell cycle checkpoint, DNA damage response (DDR) and normal physiological processes. However, the oncogenic roles of AURKB and MAD2L2 in tumorigenesis and genomic instability have also been reported. DDR acts as an arbitrator for cell fate by either repairing the damage or directing the cell to self-destruction. While there is strong evidence of interphase DDR, evidence of mitotic DDR is just emerging and remains largely unelucidated. To date, inhibitors of the DDR components show effective anti-cancer roles. Contrarily, long-term resistance towards drugs that target only one DDR target is becoming a challenge. Targeting interactions between protein-protein or protein-DNA holds prominent therapeutic potential. Both AURKB and MAD2L2 play critical roles in the success of mitosis and their emerging roles in mitotic DDR cannot be ignored. Small molecule inhibitors for AURKB are in clinical trials. A few lead compounds towards MAD2L2 inhibition have been discovered. Targeting mitotic DDR components and their interaction is emerging as a potent next generation anti-cancer therapeutic target. This can be done by developing small molecule inhibitors for AURKB and MAD2L2, thereby targeting DDR components as anti-cancer therapeutic targets and/or targeting mitotic DDR. This review focuses on AURKB and MAD2L2 prospective synergy to deregulate the p53 DDR pathway and promote favourable conditions for uncontrolled cell proliferation.


Assuntos
Aurora Quinase B/metabolismo , Proteínas Mad2/metabolismo , Aurora Quinase B/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Proliferação de Células/fisiologia , Dano ao DNA/genética , Dano ao DNA/fisiologia , Humanos , Proteínas Mad2/genética , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
15.
Mutat Res Rev Mutat Res ; 787: 108364, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34083043

RESUMO

The purpose of this review is to evaluate the literature on the genotoxicity of cumene (CAS # 98-82-8) and to assess the role of mutagenicity, if any, in the mode of action for cumene-induced rodent tumors. The studies reviewed included microbial mutagenicity, DNA damage/ repair, cytogenetic effects, and gene mutations. In reviewing these studies, attention was paid to their conformance to applicable OECD test guidelines which are considered as internationally recognized standards for performing these assays. Cumene was not a bacterial mutagen and did not induce Hprt mutations in CHO cell cultures. In the primary rat hepatocyte cultures, cumene induced unscheduled DNA synthesis in one study but this response could not be reproduced in an independent study using a similar protocol. In a study that is not fully compliant to the current OECD guideline, no increase in chromosomal aberrations was observed in CHO cells treated with cumene. The weight of the evidence (WoE) from multiple in vivo studies indicates that cumene is not a clastogen or aneugen. The weak positive response in an in vivo comet assay in the rat liver and mouse lung tissues is of questionable significance due to several study deficiencies. The genotoxicity profile of cumene does not match that of a classic DNA-reactive molecule and the available data does not support a conclusion that cumene is an in vivo mutagen. As such, mutagenicity does not appear to be an early key event in cumene-induced rodent tumors and alternate hypothesized non-mutagenic modes-of-action are presented. Further data are necessary to rule in or rule out a particular MoA.


Assuntos
Dano ao DNA/fisiologia , Animais , Células CHO , Ensaio Cometa , Cricetulus , Dano ao DNA/genética , Humanos , Mutagênese/genética , Mutagênese/fisiologia , Testes de Mutagenicidade , Mutação/genética , Ratos
16.
Mutat Res Rev Mutat Res ; 787: 108347, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34083046

RESUMO

APE2 is a rising vital player in the maintenance of genome and epigenome integrity. In the past several years, a series of studies have shown the critical roles and functions of APE2. We seek to provide the first comprehensive review on several aspects of APE2 in genome and epigenome integrity. We first summarize the distinct functional domains or motifs within APE2 including EEP (endonuclease/exonuclease/phosphatase) domain, PIP box and Zf-GRF motifs from eight species (i.e., Homo sapiens, Mus musculus, Xenopus laevis, Ciona intestinalis, Arabidopsis thaliana, Schizosaccharomyces pombe, Saccharomyces cerevisiae, and Trypanosoma cruzi). Then we analyze various APE2 nuclease activities and associated DNA substrates, including AP endonuclease, 3'-phosphodiesterase, 3'-phosphatase, and 3'-5' exonuclease activities. We also examine several APE2 interaction proteins, including PCNA, Chk1, APE1, Myh1, and homologous recombination (HR) factors such as Rad51, Rad52, BRCA1, BRCA2, and BARD1. Furthermore, we provide insights into the roles of APE2 in various DNA repair pathways (base excision repair, single-strand break repair, and double-strand break repair), DNA damage response (DDR) pathways (ATR-Chk1 and p53-dependent), immunoglobulin class switch recombination and somatic hypermutation, as well as active DNA demethylation. Lastly, we summarize critical functions of APE2 in growth, development, and diseases. In this review, we provide the first comprehensive perspective which dissects all aspects of the multiple-function protein APE2 in genome and epigenome integrity.


Assuntos
Proteínas de Arabidopsis/genética , Endonucleases/genética , Animais , Proteínas de Arabidopsis/metabolismo , Dano ao DNA/genética , Dano ao DNA/fisiologia , Desmetilação do DNA , Reparo do DNA/genética , Reparo do DNA/fisiologia , Epigenoma/genética , Humanos , Imunidade/genética , Imunidade/fisiologia , Rad51 Recombinase/genética , Rad51 Recombinase/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo
17.
Mutat Res Rev Mutat Res ; 787: 108348, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34083055

RESUMO

Coronary artery disease (CAD) is the leading cause of morbidity and mortality worldwide. Coronary angiography allows an accurate assessment of the extent and severity of atherosclerotic coronary narrowing, but it provides little characterization of early detection of potentially asymptomatic vulnerable plaque. The identification of the coronary "vulnerable patient" or high-risk plaques remains a major challenge in the treatment of CAD. Recently, growing evidence shows that DNA damage plays a role in the initiation and progression of atherosclerotic plaque. Cytokinesis-block micronucleus (CBMN) assay is one of the most frequently used and validated method for assessing chromosomal damage and genetic instability. Accordingly, the purpose of this systematic review was to retrieve and discuss existing literature on the studies assessing the association between MN and angiographically-proven CAD. A total of 8 studies published between 2001 and 2017 were included in the meta-analysis. Despite a large heterogeneity between studies (I2= 99.7 %, p < 0.0001), an overall increase of MN frequencies was found in patients with CAD compared with control group (meta-MR = 1.96; 95 % CI, 1.5-3.2, p = 0.009). A subgroup analysis showed an increase in the frequency of MN formation for both two- vessel (MR = 2.13, 95 % CI: 0.9-6.9, p = 0.08) and three-vessel disease (MR = 2.89, 95 % CI: 1.84-4.55, P = 0.06). Overall, the results of this meta-analysis provide evidence of an association between CBMN and presence, extent and severity of angiographically-assessed CAD. However, the small number of papers analyzed requires further large and more rigorously designed studies, carefully considering a series of clinical confounding factors, such as the quality of the metabolic control, the influence of drugs and radiation imaging treatments.


Assuntos
Doença da Artéria Coronariana/genética , Animais , Citocinese/genética , Citocinese/fisiologia , Dano ao DNA/genética , Dano ao DNA/fisiologia , Humanos , Micronúcleos com Defeito Cromossômico , Testes para Micronúcleos
18.
Mutat Res Rev Mutat Res ; 787: 108372, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34083057

RESUMO

Micronucleus (MN) assay has been widely used as a biomarker of DNA damage, chromosomal instability, cancer risk and accelerated aging in many epidemiological studies. In this narrative review and meta-analysis we assessed the association between lymphocyte micronuclei (MNi) and cancers of the skin, blood, digestive tract, and prostate. The review identified nineteen studies with 717 disease subjects and 782 controls. Significant increases in MRi for MNi were observed in the following groups: subjects with blood cancer (MRi = 3.98; 95 % CI: 1.98-7.99; p = 0.000) and colorectal cancer (excluding IBD) (MRi = 2.69; 95 % CI: 1.82-3.98, p < 0.000). The results of this review suggest that lymphocyte MNi are a biomarker of DNA damage and chromosomal instability in people with haematological or colorectal cancers. However, the MRi for lymphocyte MNi in subjects with cancers of skin, prostate, esophagus was not significantly increased. More case-control and prospective studies are warranted to further verify the observed trends and to better understand the role of lymphocyte MNi as a biomarker of cancer risk in blood, skin, digestive tract and prostate.


Assuntos
Neoplasias Colorretais/genética , Testes para Micronúcleos/métodos , Instabilidade Cromossômica/genética , Dano ao DNA/genética , Dano ao DNA/fisiologia , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/patologia , Humanos , Masculino
19.
Biochim Biophys Acta Proteins Proteom ; 1869(8): 140669, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33957291

RESUMO

Covalent binding of DNA to proteins produces DNA-protein cross-links (DPCs). DPCs are formed as intermediates of enzymatic processes, generated from the reactions of protein nucleophiles with DNA electrophiles, and produced by endogenous and exogenous cross-linking agents. DPCs are heterogeneous due to the variations of DNA conjugation sites, flanking DNA structures, protein sizes, and cross-link bonds. Unrepaired DPCs are toxic because their bulky sizes physically block DNA replication and transcription, resulting in impaired genomic integrity. Compared to other types of DNA lesions, DPC repair is less understood. Emerging evidence suggests a general repair model that DPCs are proteolyzed by the proteasome and/or DPC proteases, followed by the peptide removal through canonical repair pathways. Herein, we first describe the recently discovered DPCs. We then review the mechanisms of DPC proteolysis with the focus on recently identified DPC proteases. Finally, distinct pathways that bypass or remove the cross-linked peptides following proteolysis are discussed.


Assuntos
Reparo do DNA/fisiologia , Proteínas de Ligação a DNA/metabolismo , DNA/metabolismo , Reagentes para Ligações Cruzadas/química , DNA/química , Dano ao DNA/fisiologia , Replicação do DNA/fisiologia , Proteínas de Ligação a DNA/fisiologia , Biossíntese de Proteínas , Proteólise
20.
Neurochem Res ; 46(8): 1970-1980, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33973102

RESUMO

Reportedly, TWIK-related spinal cord K+ (TRESK) deficiency in spinal cord neurons positively correlates with the mechanism underlying neuropathic pain (NP). However, the precise effects of TRESK on neurons of the spinal cord remain elusive. In the present study, we investigated the impact of TRESK silencing on spinal cord neurons to further elucidate the downstream mechanisms of TRESK. Herein, neurons of the dorsal spinal cord were cultured as a cell model for investigations. Apoptosis, oxidative stress, and DNA damage-related proteins were evaluated. Additionally, flow cytometry, microarray profiling, real-time polymerase chain reaction (PCR), western blotting, fluorescence in situ hybridization (FISH), immunofluorescence, and enzyme-linked immunosorbent assay (ELISA) were performed. In cultured neurons, the downregulation of TRESK mRNA expression induced apoptosis of dorsal spinal cord neurons. Using real-time PCR and western blotting, the upregulation of LncRNA Gm11874 (Gm11874) and ATP5i, screened from the gene chip, was confirmed. On silencing TRESK, expression levels of γ-H2AX, poly [ADP-ribose] polymerase 1 (PARP-1), FoxO1, FoxO3, MitoSOX, malondialdehyde (MDA), and 8-hydroxy-2' -deoxyguanosine (8-OHdG), which are known indices of oxidative stress and DNA damage, were significantly elevated. Moreover, ATP induced oxidative stress, DNA damage, and apoptosis were reduced by ATP5i siRNA. Finally, Gm11874 and ATP5i were co-expressed in spinal cord neurons in a FISH experiment, and the expression of ATP5i was positively regulated by Gm11874. These results implied that ATP5i induced oxidative stress and DNA damage, resulting in neuronal apoptosis, and Gm11874 was confirmed to act upstream of ATP5i. Our study revealed that TRESK silencing upregulated Gm11874 to induce apoptosis of spinal cord neurons, which resulted in ATP5i promoting oxidative stress and DNA damage. These findings could highlight the TRESK-mediated NP mechanism.


Assuntos
Apoptose/fisiologia , Dano ao DNA/fisiologia , Neurônios/metabolismo , Estresse Oxidativo/fisiologia , Canais de Potássio/metabolismo , RNA Longo não Codificante/metabolismo , Animais , Camundongos , RNA Interferente Pequeno/farmacologia , Medula Espinal/citologia , Medula Espinal/metabolismo , Regulação para Cima/fisiologia
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