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1.
J Nanobiotechnology ; 22(1): 228, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38715049

RESUMO

Development of ferroptosis-inducible nanoplatforms with high efficiency and specificity is highly needed and challenging in tumor ferrotherapy. Here, we demonstrate highly effective tumor ferrotherapy using iron (II)-based metal-organic framework (FessMOF) nanoparticles, assembled from disulfide bonds and ferrous ions. The as-prepared FessMOF nanoparticles exhibit peroxidase-like activity and pH/glutathione-dependent degradability, which enables tumor-responsive catalytic therapy and glutathione depletion by the thiol/disulfide exchange to suppress glutathione peroxidase 4, respectively. Upon PEGylation and Actinomycin D (ActD) loading, the resulting FessMOF/ActD-PEG nanoplatform induces marked DNA damage and lipid peroxidation. Concurrently, we found that ActD can inhibit Xc- system and elicit ferritinophagy, which further boosts the ferrotherapeutic efficacy of the FessMOF/ActD-PEG. In vivo experiments demonstrate that our fabricated nanoplatform presents excellent biocompatibility and a high tumor inhibition rate of 91.89%.


Assuntos
Dano ao DNA , Ferroptose , Ferro , Estruturas Metalorgânicas , Estruturas Metalorgânicas/química , Estruturas Metalorgânicas/farmacologia , Ferroptose/efeitos dos fármacos , Animais , Humanos , Camundongos , Dano ao DNA/efeitos dos fármacos , Ferro/química , Linhagem Celular Tumoral , Reparo do DNA/efeitos dos fármacos , Nanopartículas/química , Neoplasias/tratamento farmacológico , Camundongos Endogâmicos BALB C , Feminino
2.
Chem Biol Drug Des ; 103(5): e14536, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38725079

RESUMO

This research was designed to prospect the mechanism and impact of glycyrrhizic acid (GA) on DNA damage repair and cisplatin (CP)-induced apoptosis of melanoma cells. First, human melanoma cell SK-MEL-28 was stimulated using GA for 24, 48, and 72 h. Then, the optimal treatment time and dosage were selected. After that, cell counting kit-8 (CCK-8) was employed for testing the cell viability, flow cytometry for the apoptosis, comet assay for the DNA damage of cells, and western blot for the cleaved-Caspase3, Caspase3, Bcl-2, and γH2AX protein expression levels. The experimental outcomes exhibited that as the GA concentration climbed up, the SK-MEL-28 cell viability dropped largely, while the apoptosis level raised significantly, especially at the concentration of 100 µm. In addition, compared with GA or CPtreatment only, CP combined with GA notably suppressed the viability of melanoma cells and promoted cell apoptosis at the cytological level. At the protein level, the combined treatment notably downregulated the Bcl-2 and Caspase3 expression levels, while significantly upregulated the cleaved-Caspase3 and γH2AX expression levels. Besides, CP + GA treatment promoted DNA damage at the DNA molecular level. Collectively, both GA and CP can inhibit DNA damage repair and enhance the apoptosis of SK-MEL-28 cells, and the synergistic treatment of both exhibits better efficacy.


Assuntos
Apoptose , Cisplatino , Dano ao DNA , Reparo do DNA , Ácido Glicirrízico , Melanoma , Cisplatino/farmacologia , Humanos , Ácido Glicirrízico/farmacologia , Ácido Glicirrízico/química , Apoptose/efeitos dos fármacos , Melanoma/tratamento farmacológico , Melanoma/metabolismo , Melanoma/patologia , Linhagem Celular Tumoral , Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Antineoplásicos/farmacologia , Antineoplásicos/química , Caspase 3/metabolismo , Sinergismo Farmacológico , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo
3.
An Acad Bras Cienc ; 96(2): e20240014, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38747842

RESUMO

Despite the prevalence of substance use during pregnancy, studies focusing exclusively on Neonatal Intensive Care Units (NICU) admissions remain limited. This study investigates the impact of maternal use of tobacco, alcohol, and/or crack, on neonatal outcomes among infants admitted to three Brazilian NICUs. Additionally, the investigation explores the impact of substance use on DNA damage in newborns. Over a one-year period, data from 254 newborns were collected through medical records, accompanied by blood samples. Findings revealed that 16.1% of newborns had mothers reporting substance use during pregnancy. Significant associations were found between maternal substance use and adverse neonatal outcomes, including low birth weight, preterm birth, and sexually transmitted infections. Maternal variables linked to substance use encompassed non-white skin color, low education, non-masonry housing, lower income, diseases in other children, and fewer prenatal consultations. Notably, neonatal DNA damage showed no significant association with substance use. Our results underscore the substantial impact of maternal substance use on NICU-admitted infants, emphasizing the necessity for targeted interventions that address both neonatal health and maternal well-being, thereby underscoring the crucial role of comprehensive care in NICU settings.


Assuntos
Consumo de Bebidas Alcoólicas , Unidades de Terapia Intensiva Neonatal , Humanos , Gravidez , Feminino , Recém-Nascido , Brasil/epidemiologia , Adulto , Consumo de Bebidas Alcoólicas/efeitos adversos , Complicações na Gravidez , Masculino , Adulto Jovem , Resultado da Gravidez , Recém-Nascido de Baixo Peso , Cocaína Crack/efeitos adversos , Transtornos Relacionados ao Uso de Cocaína/epidemiologia , Fatores de Risco , Fatores Socioeconômicos , Dano ao DNA , Efeitos Tardios da Exposição Pré-Natal
4.
Int J Mol Sci ; 25(9)2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38732262

RESUMO

Vitamin B12 (cobalamin) is an essential nutrient for humans and animals. Metabolically active forms of B12-methylcobalamin and 5-deoxyadenosylcobalamin are cofactors for the enzymes methionine synthase and mitochondrial methylmalonyl-CoA mutase. Malfunction of these enzymes due to a scarcity of vitamin B12 leads to disturbance of one-carbon metabolism and impaired mitochondrial function. A significant fraction of the population (up to 20%) is deficient in vitamin B12, with a higher rate of deficiency among elderly people. B12 deficiency is associated with numerous hallmarks of aging at the cellular and organismal levels. Cellular senescence is characterized by high levels of DNA damage by metabolic abnormalities, increased mitochondrial dysfunction, and disturbance of epigenetic regulation. B12 deficiency could be responsible for or play a crucial part in these disorders. In this review, we focus on a comprehensive analysis of molecular mechanisms through which vitamin B12 influences aging. We review new data about how deficiency in vitamin B12 may accelerate cellular aging. Despite indications that vitamin B12 has an important role in health and healthy aging, knowledge of the influence of vitamin B12 on aging is still limited and requires further research.


Assuntos
Envelhecimento , Inflamação , Deficiência de Vitamina B 12 , Vitamina B 12 , Humanos , Vitamina B 12/metabolismo , Animais , Envelhecimento/metabolismo , Deficiência de Vitamina B 12/metabolismo , Inflamação/metabolismo , Epigênese Genética , Senescência Celular , Mitocôndrias/metabolismo , Dano ao DNA
5.
Nat Commun ; 15(1): 4002, 2024 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-38734692

RESUMO

Precise genome editing is crucial for establishing isogenic human disease models and ex vivo stem cell therapy from the patient-derived hPSCs. Unlike Cas9-mediated knock-in, cytosine base editor and prime editor achieve the desirable gene correction without inducing DNA double strand breaks. However, hPSCs possess highly active DNA repair pathways and are particularly susceptible to p53-dependent cell death. These unique characteristics impede the efficiency of gene editing in hPSCs. Here, we demonstrate that dual inhibition of p53-mediated cell death and distinct activation of the DNA damage repair system upon DNA damage by cytosine base editor or prime editor additively enhanced editing efficiency in hPSCs. The BE4stem system comprised of p53DD, a dominant negative p53, and three UNG inhibitor, engineered to specifically diminish base excision repair, improves cytosine base editor efficiency in hPSCs. Addition of dominant negative MLH1 to inhibit mismatch repair activity and p53DD in the conventional prime editor system also significantly enhances prime editor efficiency in hPSCs. Thus, combined inhibition of the distinct cellular cascades engaged in hPSCs upon gene editing could significantly enhance precise genome editing in these cells.


Assuntos
Sistemas CRISPR-Cas , Dano ao DNA , Reparo do DNA , Edição de Genes , Proteína Supressora de Tumor p53 , Edição de Genes/métodos , Humanos , Proteína Supressora de Tumor p53/metabolismo , Proteína Supressora de Tumor p53/genética , Linhagem Celular , Proteína 1 Homóloga a MutL/genética , Proteína 1 Homóloga a MutL/metabolismo , Citosina/metabolismo
6.
Cell Mol Life Sci ; 81(1): 210, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38717553

RESUMO

The cytoophidium is an evolutionarily conserved subcellular structure formed by filamentous polymers of metabolic enzymes. In vertebrates, inosine monophosphate dehydrogenase (IMPDH), which catalyses the rate-limiting step in guanosine triphosphate (GTP) biosynthesis, is one of the best-known cytoophidium-forming enzymes. Formation of the cytoophidium has been proposed to alleviate the inhibition of IMPDH, thereby facilitating GTP production to support the rapid proliferation of certain cell types such as lymphocytes, cancer cells and pluripotent stem cells (PSCs). However, past studies lacked appropriate models to elucidate the significance of IMPDH cytoophidium under normal physiological conditions. In this study, we demonstrate that the presence of IMPDH cytoophidium in mouse PSCs correlates with their metabolic status rather than pluripotency. By introducing IMPDH2 Y12C point mutation through genome editing, we established mouse embryonic stem cell (ESC) lines incapable of forming IMPDH polymers and the cytoophidium. Our data indicate an important role of IMPDH cytoophidium in sustaining a positive feedback loop that couples nucleotide biosynthesis with upstream metabolic pathways. Additionally, we find that IMPDH2 Y12C mutation leads to decreased cell proliferation and increased DNA damage in teratomas, as well as impaired embryo development following blastocoel injection. Further analysis shows that IMPDH cytoophidium assembly in mouse embryonic development begins after implantation and gradually increases throughout fetal development. These findings provide insights into the regulation of IMPDH polymerisation in embryogenesis and its significance in coordinating cell metabolism and development.


Assuntos
Proliferação de Células , IMP Desidrogenase , Animais , IMP Desidrogenase/metabolismo , IMP Desidrogenase/genética , Camundongos , Desenvolvimento Fetal/genética , Células-Tronco Pluripotentes/metabolismo , Células-Tronco Pluripotentes/citologia , Feminino , Guanosina Trifosfato/metabolismo , Dano ao DNA , Camundongos Endogâmicos C57BL
7.
Nat Commun ; 15(1): 3883, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38719805

RESUMO

The long interspersed nuclear element-1 (LINE-1 or L1) retrotransposon is the only active autonomously replicating retrotransposon in the human genome. L1 harms the cell by inserting new copies, generating DNA damage, and triggering inflammation. Therefore, L1 inhibition could be used to treat many diseases associated with these processes. Previous research has focused on inhibition of the L1 reverse transcriptase due to the prevalence of well-characterized inhibitors of related viral enzymes. Here we present the L1 endonuclease as another target for reducing L1 activity. We characterize structurally diverse small molecule endonuclease inhibitors using computational, biochemical, and biophysical methods. We also show that these inhibitors reduce L1 retrotransposition, L1-induced DNA damage, and inflammation reinforced by L1 in senescent cells. These inhibitors could be used for further pharmacological development and as tools to better understand the life cycle of this element and its impact on disease processes.


Assuntos
Endonucleases , Elementos Nucleotídeos Longos e Dispersos , Humanos , Elementos Nucleotídeos Longos e Dispersos/genética , Endonucleases/metabolismo , Endonucleases/genética , Endonucleases/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Dano ao DNA , Bibliotecas de Moléculas Pequenas/farmacologia , Bibliotecas de Moléculas Pequenas/química , Senescência Celular/efeitos dos fármacos , Desoxirribonuclease I
8.
Cell Death Dis ; 15(5): 321, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38719812

RESUMO

RAD18, an important ubiquitin E3 ligase, plays a dual role in translesion DNA synthesis (TLS) and homologous recombination (HR) repair. However, whether and how the regulatory mechanism of O-linked N-acetylglucosamine (O-GlcNAc) modification governing RAD18 and its function during these processes remains unknown. Here, we report that human RAD18, can undergo O-GlcNAcylation at Ser130/Ser164/Thr468, which is important for optimal RAD18 accumulation at DNA damage sites. Mechanistically, abrogation of RAD18 O-GlcNAcylation limits CDC7-dependent RAD18 Ser434 phosphorylation, which in turn significantly reduces damage-induced PCNA monoubiquitination, impairs Polη focus formation and enhances UV sensitivity. Moreover, the ubiquitin and RAD51C binding ability of RAD18 at DNA double-strand breaks (DSBs) is O-GlcNAcylation-dependent. O-GlcNAcylated RAD18 promotes the binding of RAD51 to damaged DNA during HR and decreases CPT hypersensitivity. Our findings demonstrate a novel role of RAD18 O-GlcNAcylation in TLS and HR regulation, establishing a new rationale to improve chemotherapeutic treatment.


Assuntos
Acetilglucosamina , Proteínas de Ligação a DNA , Antígeno Nuclear de Célula em Proliferação , Rad51 Recombinase , Reparo de DNA por Recombinação , Ubiquitina-Proteína Ligases , Humanos , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/genética , Ubiquitina-Proteína Ligases/metabolismo , Acetilglucosamina/metabolismo , Rad51 Recombinase/metabolismo , Antígeno Nuclear de Célula em Proliferação/metabolismo , Fosforilação , Replicação do DNA , Ubiquitinação , Quebras de DNA de Cadeia Dupla , DNA Polimerase Dirigida por DNA/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Dano ao DNA , DNA/metabolismo , Células HEK293 , Raios Ultravioleta , Ligação Proteica , Glicosilação , Síntese de DNA Translesão
9.
Saudi Med J ; 45(5): 468-475, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38734439

RESUMO

OBJECTIVES: To compare the genotoxic effects of desflurane and propofol using comet assay in patients undergoing elective discectomy surgery. METHODS: This was a randomized controlled study. Patients who underwent elective lumbar discectomy under general anesthesia with propofol or desflurane were included in the study. Venous blood samples were obtained at 4 different time points: 5 minutes before anesthesia induction (T1), 2 hours after the start of anesthesia (T2), the first day after surgery (T3), and the fifth day following surgery (T4). Deoxyribonucleic acid damage in lymphocytes was assessed via the comet assay. RESULTS: A total of 30 patients, 15 in each group, were included in the analysis. The groups were similar in terms of age and gender distribution. There were no significant differences in demographics, duration of surgery, total remifentanil consumption, and total rocuronium bromide consumption. The comet assay revealed that head length, head intensity, tail intensity, tail moment at T1 were similar in the desflurane and propofol groups. Head length, tail length and tail moment measured in the desflurane group at T4 were significantly higher compared to the propofol group. Tail lengths of the desflurane group at T1, T2 and T3 were significantly higher than the corresponding values in the propofol group. CONCLUSION: Propofol and desflurane do not appear to induce DNA damage in lymphocytes. However, when the quantitative data were compared, it was determined that propofol had relatively lower genotoxic potential than desflurane.ClinicalTrials.gov Reg. No.: NCT05185167.


Assuntos
Anestésicos Inalatórios , Ensaio Cometa , Dano ao DNA , Desflurano , Discotomia , Linfócitos , Propofol , Humanos , Propofol/efeitos adversos , Discotomia/métodos , Ensaio Cometa/métodos , Masculino , Linfócitos/efeitos dos fármacos , Feminino , Adulto , Pessoa de Meia-Idade , Anestésicos Inalatórios/efeitos adversos , Dano ao DNA/efeitos dos fármacos , Vértebras Lombares/cirurgia , Anestésicos Intravenosos/efeitos adversos , Isoflurano/análogos & derivados , Isoflurano/efeitos adversos
10.
Int J Mol Med ; 53(6)2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38695243

RESUMO

Numerous studies have attempted to develop biological markers for the response to radiation for broad and straightforward application in the field of radiation. Based on a public database, the present study selected several molecules involved in the DNA damage repair response, cell cycle regulation and cytokine signaling as promising candidates for low­dose radiation­sensitive markers. The HuT 78 and IM­9 cell lines were irradiated in a concentration­dependent manner, and the expression of these molecules was analyzed using western blot analysis. Notably, the activation of ataxia telangiectasia mutated (ATM), checkpoint kinase 2 (CHK2), p53 and H2A histone family member X (H2AX) significantly increased in a concentration­dependent manner, which was also observed in human peripheral blood mononuclear cells. To determine the radioprotective effects of cinobufagin, as an ATM and CHK2 activator, an in vivo model was employed using sub­lethal and lethal doses in irradiated mice. Treatment with cinobufagin increased the number of bone marrow cells in sub­lethal irradiated mice, and slightly elongated the survival of lethally irradiated mice, although the difference was not statistically significant. Therefore, KU60019, BML­277, pifithrin­α, and nutlin­3a were evaluated for their ability to modulate radiation­induced cell death. The use of BML­277 led to a decrease in radiation­induced p­CHK2 and γH2AX levels and mitigated radiation­induced apoptosis. On the whole, the present study provides a novel approach for developing drug candidates based on the profiling of biological radiation­sensitive markers. These markers hold promise for predicting radiation exposure and assessing the associated human risk.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia , Dano ao DNA , Radiação Ionizante , Transdução de Sinais , Dano ao DNA/efeitos da radiação , Dano ao DNA/efeitos dos fármacos , Humanos , Animais , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/efeitos da radiação , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Camundongos , Quinase do Ponto de Checagem 2/metabolismo , Quinase do Ponto de Checagem 2/genética , Histonas/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Proteína Supressora de Tumor p53/genética , Masculino , Imidazóis/farmacologia , Protetores contra Radiação/farmacologia , Linhagem Celular Tumoral , Relação Dose-Resposta à Radiação
11.
Part Fibre Toxicol ; 21(1): 24, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38760761

RESUMO

BACKGROUND: Significant variations exist in the forms of ZnO, making it impossible to test all forms in in vivo inhalation studies. Hence, grouping and read-across is a common approach under REACH to evaluate the toxicological profile of familiar substances. The objective of this paper is to investigate the potential role of dissolution, size, or coating in grouping ZnO (nano)forms for the purpose of hazard assessment. We performed a 90-day inhalation study (OECD test guideline no. (TG) 413) in rats combined with a reproduction/developmental (neuro)toxicity screening test (TG 421/424/426) with coated and uncoated ZnO nanoforms in comparison with microscale ZnO particles and soluble zinc sulfate. In addition, genotoxicity in the nasal cavity, lungs, liver, and bone marrow was examined via comet assay (TG 489) after 14-day inhalation exposure. RESULTS: ZnO nanoparticles caused local toxicity in the respiratory tract. Systemic effects that were not related to the local irritation were not observed. There was no indication of impaired fertility, developmental toxicity, or developmental neurotoxicity. No indication for genotoxicity of any of the test substances was observed. Local effects were similar across the different ZnO test substances and were reversible after the end of the exposure. CONCLUSION: With exception of local toxicity, this study could not confirm the occasional findings in some of the previous studies regarding the above-mentioned toxicological endpoints. The two representative ZnO nanoforms and the microscale particles showed similar local effects. The ZnO nanoforms most likely exhibit their effects by zinc ions as no particles could be detected after the end of the exposure, and exposure to rapidly soluble zinc sulfate had similar effects. Obviously, material differences between the ZnO particles do not substantially alter their toxicokinetics and toxicodynamics. The grouping of ZnO nanoforms into a set of similar nanoforms is justified by these observations.


Assuntos
Exposição por Inalação , Óxido de Zinco , Animais , Óxido de Zinco/toxicidade , Óxido de Zinco/química , Masculino , Feminino , Nanopartículas Metálicas/toxicidade , Nanopartículas Metálicas/química , Tamanho da Partícula , Administração por Inalação , Dano ao DNA , Ratos , Ensaio Cometa , Ratos Wistar , Reprodução/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo
12.
Sci Rep ; 14(1): 11468, 2024 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-38769339

RESUMO

Diffusing alpha-emitters radiation therapy (Alpha-DaRT) is a unique method, in which interstitial sources carrying 224Ra release a chain of short-lived daughter atoms from their surface. Although DNA damage response (DDR) is crucial to inducing cell death after irradiation, how the DDR occurs during Alpha-DaRT treatment has not yet been explored. In this study, we temporo-spatially characterized DDR such as kinetics of DNA double-strand breaks (DSBs) and cell cycle, in two-dimensional (2D) culture conditions qualitatively mimicking Alpha-DaRT treatments, by employing HeLa cells expressing the Fucci cell cycle-visualizing system. The distribution of the alpha-particle pits detected by a plastic nuclear track detector, CR-39, strongly correlated with γH2AX staining, a marker of DSBs, around the 224Ra source, but the area of G2 arrested cells was more widely spread 24 h from the start of the exposure. Thereafter, close time-lapse observation revealed varying cell cycle kinetics, depending on the distance from the source. A medium containing daughter nuclides prepared from 224Ra sources allowed us to estimate the radiation dose after 24 h of exposure, and determine surviving fractions. The present experimental model revealed for the first time temporo-spatial information of DDR occurring around the source in its early stages.


Assuntos
Partículas alfa , Quebras de DNA de Cadeia Dupla , Humanos , Células HeLa , Quebras de DNA de Cadeia Dupla/efeitos da radiação , Dano ao DNA/efeitos da radiação , Ciclo Celular/efeitos da radiação , Histonas/metabolismo , Técnicas de Cultura de Células/métodos
13.
Sci Rep ; 14(1): 11502, 2024 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-38769353

RESUMO

Astronauts travelling in space will be exposed to mixed beams of particle radiation and photons. Exposure limits that correspond to defined cancer risk are calculated by multiplying absorbed doses by a radiation-type specific quality factor that reflects the biological effectiveness of the particle without considering possible interaction with photons. We have shown previously that alpha radiation and X-rays may interact resulting in synergistic DNA damage responses in human peripheral blood lymphocytes but the level of intra-individual variability was high. In order to assess the variability and validate the synergism, blood from two male donors was drawn at 9 time points during 3 seasons of the year and exposed to 0-2 Gy of X-rays, alpha particles or 1:1 mixture of both (half the dose each). DNA damage response was quantified by chromosomal aberrations and by mRNA levels of 3 radiation-responsive genes FDXR, CDKN1A and MDM2 measured 24 h post exposure. The quality of response in terms of differential expression of alternative transcripts was assessed by using two primer pairs per gene. A consistently higher than expected effect of mixed beams was found in both donors for chromosomal aberrations and gene expression with some seasonal variability for the latter. No synergy was detected for alternative transcription.


Assuntos
Aberrações Cromossômicas , Linfócitos , Radiação Ionizante , Humanos , Linfócitos/efeitos da radiação , Linfócitos/metabolismo , Masculino , Aberrações Cromossômicas/efeitos da radiação , Raios X/efeitos adversos , Dano ao DNA , Voo Espacial , Partículas alfa/efeitos adversos , Transcrição Gênica/efeitos da radiação , Adulto , Regulação da Expressão Gênica/efeitos da radiação , Relação Dose-Resposta à Radiação
14.
Curr Biol ; 34(10): R504-R507, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38772339

RESUMO

Tardigrades withstand ionizing irradiation levels ∼500 times higher than humans can tolerate. Two recent papers shed light on how this might be achieved - via the transcriptional induction of DNA repair genes, the induction of a radioprotective DNA-binding protein, and possibly also the heightened capacity of repair proteins.


Assuntos
Dano ao DNA , Reparo do DNA , Tardígrados , Tardígrados/genética , Tardígrados/fisiologia , Animais , Radiação Ionizante
15.
Int J Mol Sci ; 25(9)2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38732093

RESUMO

The chromatin organization and its dynamic remodeling determine its accessibility and sensitivity to DNA damage oxidative stress, the main source of endogenous DNA damage. We studied the role of the VRK1 chromatin kinase in the response to oxidative stress. which alters the nuclear pattern of histone epigenetic modifications and phosphoproteome pathways. The early effect of oxidative stress on chromatin was studied by determining the levels of 8-oxoG lesions and the alteration of the epigenetic modification of histones. Oxidative stress caused an accumulation of 8-oxoG DNA lesions that were increased by VRK1 depletion, causing a significant accumulation of DNA strand breaks detected by labeling free 3'-DNA ends. In addition, oxidative stress altered the pattern of chromatin epigenetic marks and the nuclear phosphoproteome pathways that were impaired by VRK1 depletion. Oxidative stress induced the acetylation of H4K16ac and H3K9 and the loss of H3K4me3. The depletion of VRK1 altered all these modifications induced by oxidative stress and resulted in losses of H4K16ac and H3K9ac and increases in the H3K9me3 and H3K4me3 levels. All these changes were induced by the oxidative stress in the epigenetic pattern of histones and impaired by VRK1 depletion, indicating that VRK1 plays a major role in the functional reorganization of chromatin in the response to oxidative stress. The analysis of the nuclear phosphoproteome in response to oxidative stress detected an enrichment of the phosphorylated proteins associated with the chromosome organization and chromatin remodeling pathways, which were significantly decreased by VRK1 depletion. VRK1 depletion alters the histone epigenetic pattern and nuclear phosphoproteome pathways in response to oxidative stress. The enzymes performing post-translational epigenetic modifications are potential targets in synthetic lethality strategies for cancer therapies.


Assuntos
Epigênese Genética , Histonas , Estresse Oxidativo , Proteínas Serina-Treonina Quinases , Humanos , Histonas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteoma/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Fosfoproteínas/metabolismo , Fosfoproteínas/genética , Dano ao DNA , Núcleo Celular/metabolismo , Cromatina/metabolismo , Cromatina/genética , Linhagem Celular Tumoral , Acetilação , Processamento de Proteína Pós-Traducional
16.
J Cell Mol Med ; 28(9): e18342, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38693852

RESUMO

Urothelial carcinoma (UC) urgently requires new therapeutic options. Histone deacetylases (HDAC) are frequently dysregulated in UC and constitute interesting targets for the development of alternative therapy options. Thus, we investigated the effect of the second generation HDAC inhibitor (HDACi) quisinostat in five UC cell lines (UCC) and two normal control cell lines in comparison to romidepsin, a well characterized HDACi which was previously shown to induce cell death and cell cycle arrest. In UCC, quisinostat led to cell cycle alterations, cell death induction and DNA damage, but was well tolerated by normal cells. Combinations of quisinostat with cisplatin or the PARP inhibitor talazoparib led to decrease in cell viability and significant synergistic effect in five UCCs and platinum-resistant sublines allowing dose reduction. Further analyses in UM-UC-3 and J82 at low dose ratio revealed that the mechanisms included cell cycle disturbance, apoptosis induction and DNA damage. These combinations appeared to be well tolerated in normal cells. In conclusion, our results suggest new promising combination regimes for treatment of UC, also in the cisplatin-resistant setting.


Assuntos
Apoptose , Inibidores de Histona Desacetilases , Inibidores de Poli(ADP-Ribose) Polimerases , Neoplasias da Bexiga Urinária , Humanos , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/farmacologia , Dano ao DNA/efeitos dos fármacos , Sinergismo Farmacológico , Inibidores de Histona Desacetilases/farmacologia , Inibidores de Histona Desacetilases/uso terapêutico , Ácidos Hidroxâmicos/farmacologia , Ácidos Hidroxâmicos/uso terapêutico , Ftalazinas/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Neoplasias da Bexiga Urinária/tratamento farmacológico , Neoplasias da Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/metabolismo , Neoplasias Urológicas/tratamento farmacológico , Neoplasias Urológicas/patologia
17.
J Toxicol Environ Health A ; 87(14): 592-603, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38712866

RESUMO

Punica granatum, popularly known as pomegranate, is a fruit tree with wide worldwide distribution, containing numerous phytochemicals of great medicinal value. The aim of the present study was to determine the phytochemical profile and antioxidant potential of a protein fraction (PF) derived from P. granatum sarcotesta which is rich in lectin. In addition, the acute oral toxicity, genotoxicity and antigenotoxicity of this protein fraction (PF) from P. granatum sarcotesta was measured. The phytochemical profile of PF was determined using HPLC. The in vitro antioxidant effect was assessed using the methods of total antioxidant capacity (TAC) and DPPH and ABTS+ radical scavenging. Acute oral toxicity was determined in female Swiss mice administered a single dose of 2000 mg/kg. This PF was examined for genotoxicity and antigenotoxicity at doses of 500, 1000 and 2000 mg/kg, utilizing mouse peripheral blood cells. Phytochemical characterization detected a high content of ellagic acid and antioxidant capacity similar to that of ascorbic acid (positive control). PF was not toxic (LD50 >2000 mg/kg) and did not exert a genotoxic effect in mice. PF protected the DNA of peripheral blood cells against damage induced by cyclophosphamide. In conclusion, this PF fraction exhibited significant antioxidant activity without initiating toxic or genotoxic responses in mice.


Assuntos
Antioxidantes , Extratos Vegetais , Punica granatum , Animais , Camundongos , Antioxidantes/farmacologia , Feminino , Extratos Vegetais/toxicidade , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Punica granatum/química , Lectinas/toxicidade , Testes de Mutagenicidade , Dano ao DNA/efeitos dos fármacos , Testes de Toxicidade Aguda
18.
J Cell Biol ; 223(7)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38717338

RESUMO

Senataxin is an evolutionarily conserved RNA-DNA helicase involved in DNA repair and transcription termination that is associated with human neurodegenerative disorders. Here, we investigated whether Senataxin loss affects protein homeostasis based on previous work showing R-loop-driven accumulation of DNA damage and protein aggregates in human cells. We find that Senataxin loss results in the accumulation of insoluble proteins, including many factors known to be prone to aggregation in neurodegenerative disorders. These aggregates are located primarily in the nucleolus and are promoted by upregulation of non-coding RNAs expressed from the intergenic spacer region of ribosomal DNA. We also map sites of R-loop accumulation in human cells lacking Senataxin and find higher RNA-DNA hybrids within the ribosomal DNA, peri-centromeric regions, and other intergenic sites but not at annotated protein-coding genes. These findings indicate that Senataxin loss affects the solubility of the proteome through the regulation of transcription-dependent lesions in the nucleus and the nucleolus.


Assuntos
DNA Helicases , Enzimas Multifuncionais , RNA Helicases , RNA não Traduzido , Humanos , Nucléolo Celular/metabolismo , Nucléolo Celular/genética , Dano ao DNA , DNA Helicases/metabolismo , DNA Helicases/genética , DNA Ribossômico/genética , DNA Ribossômico/metabolismo , Enzimas Multifuncionais/metabolismo , Enzimas Multifuncionais/genética , Agregados Proteicos , Proteostase , Estruturas R-Loop/genética , RNA Helicases/metabolismo , RNA Helicases/genética , RNA não Traduzido/genética , RNA não Traduzido/metabolismo
19.
Ren Fail ; 46(1): 2349139, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38712768

RESUMO

BACKGROUND: NOP2/Sun RNA methyltransferase 5 (NSUN5) is an RNA methyltransferase that has a broad distribution and plays critical roles in various biological processes. However, our knowledge of the biological functions of NSUN5 in mammals is very limited. Therefore, in this study, we investigate the role of NSUN5 in mice. METHODS: In the present research, we built a mouse model (Nsun5-/-) using the CRISPR/Cas9 system to investigated the specific role of NSUN5. RESULTS: We observed that Nsun5-/- mice had a reduced body weight compared to wild-type mice. Additionally, their survival rate gradually decreased to 20% after postnatal day (PD) 21. Further examination revealed the Nsun5-/- mice had multiple organ damage, with the most severe damage occurring in the kidneys. Moreover, we observed glycogen deposition and fibrosis, along with a notable shorting of the primary foot processes of glomeruli in Nsun5-/- kidneys. Furthermore, we found that the kidneys of Nsun5-/- mice showed increased expression of the apoptotic signal Caspase-3 and accumulated stronger DNA damage at PD 21. CONCLUSIONS: In our study, we found that mice lacking NSUN5 died before puberty due to kidney fatal damage caused by DNA damage and cell apoptosis. These results suggest that NSUN5 plays a vital role in preventing the accumulation of DNA damage and cell apoptosis in the kidney.


Assuntos
Apoptose , Rim , Metiltransferases , Camundongos Knockout , Animais , Camundongos , Metiltransferases/genética , Metiltransferases/metabolismo , Metiltransferases/deficiência , Rim/patologia , Modelos Animais de Doenças , Dano ao DNA , Nefropatias/genética , Nefropatias/patologia , Masculino , Camundongos Endogâmicos C57BL , Sistemas CRISPR-Cas , Caspase 3/metabolismo
20.
Gut Microbes ; 16(1): 2350149, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38709233

RESUMO

Mucinous colorectal cancer (CRC) is a common histological subtype of colorectal adenocarcinoma, associated with a poor response to chemoradiotherapy. The commensal facultative anaerobes fusobacteria, have been associated with poor prognosis specifically in mesenchymal CRC. Interestingly, fusobacterial infection is especially prevalent in mucinous CRC. The objective of this study was therefore to increase our understanding of beneficial and detrimental effects of fusobacterial infection, by contrasting host cell signaling and immune responses in areas of high vs. low infection, using mucinous rectal cancer as a clinically relevant example. We employed spatial transcriptomic profiling of 106 regions of interest from 8 mucinous rectal cancer samples to study gene expression in the epithelial and immune segments across regions of high versus low fusobacterial infection. Fusobacteria high regions were associated with increased oxidative stress, DNA damage, and P53 signaling. Meanwhile regions of low fusobacterial prevalence were characterized by elevated JAK-STAT, Il-17, Il-1, chemokine and TNF signaling. Immune masks within fusobacterial high regions were characterized by elevated proportions of cytotoxic (CD8+) T cells (p = 0.037), natural killer (NK) cells (p < 0.001), B-cells (p < 0.001), and gamma delta T cells (p = 0.003). Meanwhile, fusobacteria low regions were associated with significantly greater M2 macrophage (p < 0.001), fibroblast (p < 0.001), pericyte (p = 0.002), and endothelial (p < 0.001) counts.


Assuntos
Dano ao DNA , Perfilação da Expressão Gênica , Neoplasias Retais , Transdução de Sinais , Humanos , Neoplasias Retais/genética , Neoplasias Retais/imunologia , Neoplasias Retais/microbiologia , Masculino , Feminino , Pessoa de Meia-Idade , Transcriptoma , Idoso
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