Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 47
Filtrar
Mais filtros

País/Região como assunto
Intervalo de ano de publicação
1.
Trop Anim Health Prod ; 55(4): 270, 2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37452899

RESUMO

This study aimed to evaluate the reproductive performance of Nellore suckled cows inseminated 55 (n = 304) or 65 (n = 296) h after progesterone (P4) removal in a 7-d protocol. The protocol consisted of the insertion of a device with 2 g of P4 and 2 mg of estradiol benzoate on d 0, with the device remaining in the cows for 7 d. Cows in the 55-h treatment had the P4 device removed in the morning, while cows in the 65-h treatment had the P4 device removed in the afternoon. At P4 removal, cows received intramuscularly 300 IU of eCG, 0.6 mg of estradiol cypionate and 0.52 mg cloprostenol sodium. Artificial insemination was performed according to treatments (55 vs. 65 h after P4 removal). The results of the study showed that the estrus detection rate (69% vs 65%) and pregnancy per AI (P/AI; 49% vs 49%) did no differ in cows inseminated 55 or 65 h after P4 removal, respectively. Furthermore, ovulation rate, the diameter of the largest follicle at the time of AI, and P4 concentration after AI were not affected by treatments. The probability of P/AI was not affected by parity, BCS, age, diameter of largest follicle at AI, days postpartum, BW and time to AI. This study suggests that performing AI from 55 to 65 h after the P4 removal in the 7-d-P4 protocol did not affect the reproductive performance in Nellore cows, and opens the possibility for producers to take more time to perform AI of cows in the field without affecting P/AI.


Assuntos
Remoção de Dispositivo , Progesterona , Gravidez , Feminino , Bovinos , Animais , Remoção de Dispositivo/veterinária , Reprodução , Estradiol , Ovulação , Inseminação Artificial/veterinária , Inseminação Artificial/métodos , Sincronização do Estro/métodos
2.
Trop Anim Health Prod ; 55(1): 58, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36719488

RESUMO

Progesterone (P4) is a steroid hormone that has a regulatory role in the female reproductive system. Studies on the effects of injectable progesterone on ewes are scarce, mainly related to their reproductive responses in the breeding season. This study aimed to compare reproductive performance and serum P4 concentration using injectable or intravaginal P4 in ewes. Two hundred and forty and eight Santa Inês x Dorper ewes (BW; 52.67 ± 11.76 kg; mean ± SE), body condition score (BCS; 2.5 ± 0.8; scale of 1-5), were distributed in four treatments: (i) Control: without administration of P4; (ii) CIDR: intravaginal implantation of 330 mg of P4 for 7 days; (iii) 1P4: 15 mg of P4 intramuscular (IM); and (iv) 2P4I: 30 mg of P4 IM. The first 18 days of breeding season were considered the synchronization period. Except for ewes in the control group, all other ewes received 263 µg IM of cloprostenol sodium for lysis of eventual CL at 24 h before the P4 treatment. After the synchronization period, all ewes were kept together with males for extra 28 days in the breeding season. At the beginning of breeding season, 90% of the ewes had serum P4 concentration less than 1 ng/mL. The estrus rate was greater (P < 0.01) in ewes on the CIDR treatment, with similar estrus rate among the other treatments. The P4 implant was able to keep blood P4 concentration greater than 1 ng/mL in ewes that received an implant of P4 during the 7 days. After implant removal, there was a great increase in the estrus manifestation on ewes in the CIDR treatment, leading to an increase in pregnancy rate at the beginning of breeding season. The current study demonstrated that ewes that received an intramuscular injection of 15 or 30 mg of P4 had similar reproductive performance than ewes that did not receive any P4 intramuscular injection. However, when ewes were implanted with P4 (CIDR), these animals had an increase in estrus manifestation, leading to greater pregnancy earlier during the breeding season.


Assuntos
Sincronização do Estro , Progesterona , Gravidez , Masculino , Ovinos , Feminino , Animais , Estações do Ano , Reprodução , Estro , Administração Intravaginal
3.
Trop Anim Health Prod ; 55(2): 105, 2023 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-36859568

RESUMO

Diets without forage increase the productivity in less time and favor greater practicality and better quality carcass. The corn grain is mostly used associated with pellets but processing these ingredients can bring benefits. The present study evaluated the effect of diets without forage based on whole or coarse ground corn associated with pelleted or ground protein supplement on performance, eating behavior, carcass characteristics, and ruminal morphology of feedlot lambs. Thirty-five Dorper × Santa Inês lambs were used, with 23.85 ± 3.88 kg of initial body weight and 88 ± 9 days old. The experimental design was in a randomized complete block, defined by body weight and age. The experimental diets were control (CONT), containing 90% of concentrate and 10% of forage (coastcross hay), and 4 diets without forage: WC+P, 70% whole flint corn and 30% pelleted protein supplement; WC+G, 70% whole flint corn and 30% ground protein supplement; GC+P, 70% ground flint corn and 30% pelleted protein supplement; and GC+G, 70% ground flint corn and 30% ground protein supplement. There was an interaction between treatments and experimental periods for DMI in kg/day (P = 0.01) and g/kg of BW0.75 (P < 0.01; Table 3). For the DMI in kg/day, no significant differences were observed between the treatments in any of the experimental periods. However, for DMI expressed in g/kg of BW0.75, the animals fed WC+P had lower DMI than the animals on the CONT (P < 0.01) only in the first period. The ADG, FBW, and FE were not affected by the treatments. Compared to CONT, forage-free diets decreased ingestion time (min/day) and rumination and chewing (min/day and min/g of dry matter). There was no effect of treatments for any of the carcass traits evaluated. The diets did not cause lesions suggestive of ruminitis. Forage-free diets containing whole or ground corn associated with pelleted or ground protein supplement can be used successfully for feedlot lambs; they provide proper performance and carcass characteristics, without harming the animal's health.


Assuntos
Dieta , Zea mays , Animais , Ovinos , Peso Corporal , Minerais , Fenótipo
4.
Arch Toxicol ; 95(8): 2691-2718, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34151400

RESUMO

5-Fluorouracil (5-FU) is a widely used chemotherapeutical that induces acute toxicity in the small and large intestine of patients. Symptoms can be severe and lead to the interruption of cancer treatments. However, there is limited understanding of the molecular mechanisms underlying 5-FU-induced intestinal toxicity. In this study, well-established 3D organoid models of human colon and small intestine (SI) were used to characterize 5-FU transcriptomic and metabolomic responses. Clinically relevant 5-FU concentrations for in vitro testing in organoids were established using physiologically based pharmacokinetic simulation of dosing regimens recommended for cancer patients, resulting in exposures to 10, 100 and 1000 µM. After treatment, different measurements were performed: cell viability and apoptosis; image analysis of cell morphological changes; RNA sequencing; and metabolome analysis of supernatant from organoids cultures. Based on analysis of the differentially expressed genes, the most prominent molecular pathways affected by 5-FU included cell cycle, p53 signalling, mitochondrial ATP synthesis and apoptosis. Short time-series expression miner demonstrated tissue-specific mechanisms affected by 5-FU, namely biosynthesis and transport of small molecules, and mRNA translation for colon; cell signalling mediated by Rho GTPases and fork-head box transcription factors for SI. Metabolomic analysis showed that in addition to the effects on TCA cycle and oxidative stress in both organoids, tissue-specific metabolic alterations were also induced by 5-FU. Multi-omics integration identified transcription factor E2F1, a regulator of cell cycle and apoptosis, as the best key node across all samples. These results provide new insights into 5-FU toxicity mechanisms and underline the relevance of human organoid models in the safety assessment in drug development.


Assuntos
Colo/efeitos dos fármacos , Fluoruracila/toxicidade , Intestino Delgado/efeitos dos fármacos , Modelos Biológicos , Antimetabólitos Antineoplásicos/administração & dosagem , Antimetabólitos Antineoplásicos/farmacocinética , Antimetabólitos Antineoplásicos/toxicidade , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Colo/patologia , Relação Dose-Resposta a Droga , Feminino , Fluoruracila/administração & dosagem , Fluoruracila/farmacocinética , Humanos , Intestino Delgado/patologia , Masculino , Metabolômica , Organoides/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Transcriptoma
5.
J Toxicol Environ Health A ; 83(4): 135-152, 2020 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-32114934

RESUMO

Triplaris gardneriana Wedd. is a tree used in folk medicine to treat venereal diseases and inflammation as well as a source of biological compounds with antioxidant capacity. In order to assess the safety of these bioactive compounds, the present study aimed to determine the toxicity of an ethanolic extract of T. gardneriana, (EETg). Toxicological tests included hemolytic activity, toxicity toward the brine shrimp Artemia, cytotoxicity against breast cancer cells (MCF7) and acute oral toxicity in rodents. In addition, toxicogenomics techniques were used to determine genome expression in MCF7 cells exposed to EETg. The results showed that the extract exhibits approximately 60% of hemolytic activity at the highest tested concentration (64 µg/ml) and toxicity against nauplii of Artemia sp. (LC50 of 67.85 µg/ml). Further, EETg appears to be cytotoxic to MCF7 (cell viability reduced to 40% at 250 µg/ml after 24 hr). Genomic data demonstrated differential expression of 14 genes. Data analysis indicated possible altered pathways (e.g., xenobiotic metabolism), possible adverse health risks (e.g., hepatotoxicity), and drugs with similar gene expression profile (e.g., antimicrobials). The investigation provides important information on potentially adverse aspects of EETg, which need to be considered prior to the therapeutic utilization of this plant.Abbreviations: EETg: ethanolic extract of T. gardneriana seeds; MCF7: michigan cancer foundation-7 which refers to a human breast cell line (adenocarcinoma); NGS: next-generation sequencing; edgeR: empirical analysis of digital gene expression data in R; Consensus: consensus path database; FDR: false discovery rate; NCBI: national center for biotechnology information; KEGG: kyoto encyclopedia of genes and genomes; Ingenuity: ingenuity pathway analysis software; CMAP: connectivity map; OECD: organization for economic co-operation and development; HL-60: human promyelocytic leukemia cells; PC3: prostate cancer cells.


Assuntos
Hemólise/efeitos dos fármacos , Extratos Vegetais/toxicidade , Polygonaceae/química , Sementes/química , Adulto , Animais , Artemia , Sobrevivência Celular/efeitos dos fármacos , Etanol/química , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Células MCF-7 , Camundongos , Extratos Vegetais/química , Transcriptoma , Aumento de Peso/efeitos dos fármacos , Adulto Jovem
6.
Environ Toxicol ; 35(8): 849-860, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32170993

RESUMO

The zebrafish (Danio rerio) is a small teleost fish that is becoming increasingly popular in laboratories worldwide and several attributes have also placed the zebrafish under the spotlight of (eco)toxicological studies. Since the 1990s, international organizations such as ISO and OECD have published guidelines for the use of zebrafish in ecotoxicological assessment of environmental toxicants such as the Fish Embryo Acute Toxicity (FET) test, OECD n° 236 guideline. This protocol uses 3,4-dichloroaniline (DCA), an aniline pesticide whose toxicity to fish species at early life stages is well known, as a positive control. Despite its use, little is known about its molecular mechanisms, especially in the context of the FET test. Therefore, this study aimed to investigate such changes in zebrafish larvae exposed to DCA (4 mg/L) for 96 hours using gel-free proteomics. Twenty-four proteins detected in both groups were identified as significantly affected by DCA exposure, and, when considering group-specific entities, 48 proteins were exclusive to DCA (group-specific proteins) while 248 were only detected in the control group. Proteins modulated by DCA treatment were found to be involved in metabolic processes, especially lipids and hormone metabolism (eg, Apoa1 and Apoa1b and vitelogenins), as well as proteins important for developmental processes and organogenesis (eg, Myhc4, Acta2, Sncb, and Marcksb). The results presented here may therefore provide a better understanding of the relationships between molecular changes and phenotype in zebrafish larvae treated with DCA, the reference compound of the FET test.


Assuntos
Compostos de Anilina/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Ecotoxicologia , Embrião de Mamíferos , Embrião não Mamífero/metabolismo , Larva , Proteômica , Testes de Toxicidade Aguda , Peixe-Zebra/metabolismo
7.
Arch Toxicol ; 91(6): 2343-2352, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28032149

RESUMO

Unravelling gene regulatory networks (GRNs) influenced by chemicals is a major challenge in systems toxicology. Because toxicant-induced GRNs evolve over time and dose, the analysis of global gene expression data measured at multiple time points and doses will provide insight in the adverse effects of compounds. Therefore, there is a need for mathematical methods for GRN identification from time-over-dose-dependent data. One of the current approaches for GRN inference is Time Series Network Identification (TSNI). TSNI is based on ordinary differential equations (ODE), describing the time evolution of the expression of each gene, which is assumed to be dependent on the expression of other genes and an external perturbation (i.e. chemical exposure). Here, we present Dose-Time Network Identification (DTNI), a method extending TSNI by including ODE describing how the expression of each gene evolves with dose, which is supposed to depend on the expression of other genes and the exposure time. We also adapted TSNI in order to enable inclusion of time-over-dose-dependent data from multiple compounds. Here, we show that DTNI outperforms TSNI in inferring a toxicant-induced GRN. Moreover, we show that DTNI is a suitable method to infer a GRN dose- and time-dependently induced by a group of compounds influencing a common biological process. Applying DTNI on experimental data from TG-GATEs, we demonstrate that DTNI provides in-depth information on the mode of action of compounds, in particular key events and potential molecular initiating events. Furthermore, DTNI also discloses several unknown interactions which have to be verified experimentally.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/genética , Expressão Gênica/efeitos dos fármacos , Redes Reguladoras de Genes/efeitos dos fármacos , Substâncias Perigosas/toxicidade , Modelos Biológicos , Toxicogenética/métodos , Algoritmos , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/genética , Simulação por Computador , Relação Dose-Resposta a Droga , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/etiologia , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Análise de Regressão , Reprodutibilidade dos Testes , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Fatores de Tempo
8.
Arch Toxicol ; 90(6): 1449-58, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26238291

RESUMO

Benzo(a)pyrene (BaP) is a ubiquitous carcinogen resulting from incomplete combustion of organic compounds and also present at high levels in cigarette smoke. A wide range of biological effects has been attributed to BaP and its genotoxic metabolite BPDE, but the contribution to BaP toxicity of intermediary metabolites generated along the detoxification path remains unknown. Here, we report for the first time how 3-OH-BaP, 9,10-diol and BPDE, three major BaP metabolites, temporally relate to BaP-induced transcriptomic alterations in HepG2 cells. Since BaP is also known to induce AhR activation, we additionally evaluated TCDD to source the expression of non-genotoxic AhR-mediated patterns. 9,10-Diol was shown to activate several transcription factor networks related to BaP metabolism (AhR), oxidative stress (Nrf2) and cell proliferation (HIF-1α, AP-1) in particular at early time points, while BPDE influenced expression of genes involved in cell energetics, DNA repair and apoptotic pathways. Also, in order to grasp the role of BaP and its metabolites in chemical hepatocarcinogenesis, we compared expression patterns from BaP(-metabolites) and TCDD to a signature set of approximately nine thousand gene expressions derived from hepatocellular carcinoma (HCC) patients. While transcriptome modulation by TCDD appeared not significantly related to HCC, BaP and BPDE were shown to deregulate metastatic markers via non-genotoxic and genotoxic mechanisms and activate inflammatory pathways (NF-κß signaling, cytokine-cytokine receptor interaction). BaP also showed strong repression of genes involved in cholesterol and fatty acid biosynthesis. Altogether, this study provides new insights into BaP-induced toxicity and sheds new light onto its mechanism of action as a hepatocarcinogen.


Assuntos
Benzo(a)pireno/toxicidade , Carcinógenos Ambientais/toxicidade , Adutos de DNA/genética , Dano ao DNA , Neoplasias Hepáticas/genética , Transcriptoma/efeitos dos fármacos , 7,8-Di-Hidro-7,8-Di-Hidroxibenzo(a)pireno 9,10-óxido/metabolismo , 7,8-Di-Hidro-7,8-Di-Hidroxibenzo(a)pireno 9,10-óxido/toxicidade , Benzo(a)pireno/metabolismo , Benzopirenos/metabolismo , Benzopirenos/toxicidade , Carcinógenos Ambientais/metabolismo , Adutos de DNA/metabolismo , Di-Hidroxi-Di-Hidrobenzopirenos/metabolismo , Di-Hidroxi-Di-Hidrobenzopirenos/toxicidade , Células Hep G2 , Humanos , Neoplasias Hepáticas/induzido quimicamente
9.
Methods Mol Biol ; 2753: 151-157, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38285337

RESUMO

An Adverse Outcome Pathway (AOP) is an analytical model that describes, through a graphical representation, a linear sequence of biologically connected events at different levels of biological organization, causally leading to an adverse effect on human health or the environment. In general, AOPs are constructed based on five central principles: systematic development and review, chemical-agnostic, modular, networks, and living documents. Furthermore, AOPs have the potential to be used, for example, to investigate certain molecular targets; relate the regulation of specific genes or proteins among AOPs; extrapolate biological processes, pathways, or diseases from one species to another; and even predict adverse effects in particular populations. AOPs also emerge as an alternative to animal experimentation in studies of developmental malformations. It's even possible now to develop a quantitative AOP to predict teratogenic effects for some substances. However, the construction of high-quality AOPs requires standardization in the way these models are developed and reviewed, ensuring an adequate degree of flexibility and guaranteeing efficiency. The development of AOPs should strictly be based on the guidance documents developed by the OECD. Nevertheless, an important step for those developing AOPs is the choice of an apical endpoint or an initiating molecular event in order to initiate the construction of the pathway. Another crucial step is a systematic literature review based on the random combination of the blocks of information. With these two fundamental steps completed, it only remains to follow the guidance documents on Developing and Assessing Adverse Outcome Pathways and AOP Developers' Handbook supplement provided by the OECD to organize and construct an AOP. This modern approach will bring radical changes in the field of toxicity testing, regarding the prediction of apical toxic effects using molecular-level effects.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Teratogênese , Teratologia , Animais , Humanos , Suplementos Nutricionais , Alternativas ao Uso de Animais
10.
Methods Mol Biol ; 2753: 469-482, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38285360

RESUMO

Liver plays a crucial role in detoxification processes and metabolism of xenobiotics, and therefore, it is a target organ of toxicity of different classes of chemicals. In this context, some key enzymes present in liver are considered to be good biochemical markers of hepatic damage and can have their activities determined via spectrophotometry. Aspartate and alanine aminotransferases, alkaline phosphatase, lactate dehydrogenase, and glutathione peroxidase are enzymes that have activities often changed in response to hepatotoxic compounds and can be accessed through the larval period of zebrafish (Danio rerio). In this chapter, we described methodologies for analyses of these five biomarkers in pooled zebrafish larvae through spectrophotometry.


Assuntos
Perciformes , Peixe-Zebra , Animais , Fígado , Alanina Transaminase , Biomarcadores , Larva
11.
Toxics ; 12(1)2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38250991

RESUMO

2,4-dichlorophenoxyacetic acid (2,4-D) is a widely used herbicide worldwide and is frequently found in water samples. This knowledge has prompted studies on its effects on non-target organisms, revealing significant alterations to liver structure and function. In this review, we evaluated the literature on the hepatotoxicity of 2,4-D, focusing on morphological damages, toxicity biomarkers and affected liver functions. Searches were conducted on PubMed, Web of Science and Scopus and 83 articles were selected after curation. Among these studies, 72% used in vivo models and 30% used in vitro models. Additionally, 48% used the active ingredient, and 35% used commercial formulations in exposure experiments. The most affected biomarkers were related to a decrease in antioxidant capacity through alterations in the activities of catalase, superoxide dismutase and the levels of malondialdehyde. Changes in energy metabolism, lipids, liver function, and xenobiotic metabolism were also identified. Furthermore, studies about the effects of 2,4-D in mixtures with other pesticides were found, as well as hepatoprotection trials. The reviewed data indicate the essential role of reduction in antioxidant capacity and oxidative stress in 2,4-D-induced hepatotoxicity. However, the mechanism of action of the herbicide is still not fully understood and further research in this area is necessary.

12.
Parasitol Res ; 112(5): 1953-8, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23435925

RESUMO

This study assessed new insecticidal activities of essential oils from Lippia sidoides and Croton species (Croton zehntneri, Croton nepetaefolius, Croton argyrophylloides, and Croton sonderianus) against Aedes aegypti mosquito. In addition, the acute toxicity upon mice was determined. All essential oils showed inhibition of egg hatching, with IC50 values ranging from 66.4 to 143.2 µg mL(-1), larvicidal activity with LC50 ranging from 25.5 to 94.6 µg mL(-1), and pupicidal action with PC50 ranging from 276.8 to over 500 µg mL(-1). Only L. sidoides, C. zehntneri, and C. argyrophylloides essential oils were able to inhibit the oviposition of female gravid mosquitoes with OD50 values of 35.3, 45.3, and 45.8 µg mL(-1), respectively. Oral acute toxicity in mice showed that C. sonderianus and C. argyrophylloides oils are nontoxic (LD50 > 6,000 mg.kg(-1)) while C. nepetaefolius, C. zehntneri, and L. sidoides oils are moderately toxic (LD50 3,840; 3,464, and 2,624 mg.kg(-1), respectively). The results indicate that these oils are promising sources of bioactive compounds, showing low or no toxicity to mammals.


Assuntos
Aedes/efeitos dos fármacos , Croton/química , Inseticidas/farmacologia , Lippia/química , Óleos Voláteis/farmacologia , Aedes/anatomia & histologia , Aedes/classificação , Aedes/fisiologia , Animais , Feminino , Inseticidas/toxicidade , Larva/efeitos dos fármacos , Dose Letal Mediana , Camundongos , Óleos Voláteis/toxicidade , Oviposição/efeitos dos fármacos , Óvulo/efeitos dos fármacos , Óvulo/crescimento & desenvolvimento , Óleos de Plantas/farmacologia , Óleos de Plantas/toxicidade , Especificidade da Espécie
13.
Environ Toxicol Chem ; 42(12): 2519-2528, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37849373

RESUMO

We propose an adverse outcome pathway (AOP) for reproductive dysfunction via oxidative stress (OS). The AOP was developed based on Organisation for Economic Co-operation and Development (OECD) Guidance Document 184 and on the specific considerations of the OECD users' handbook supplement to the guidance document for developing and assessing AOPs (no. 233). According to the qualitative and quantitative experimental data evaluation, glutathione (GSH) conjugation is the first upstream key event (KE) of this AOP to reproductive dysfunction triggering OS. This event causes depletion of GSH basal levels (KE2 ). Consequently, this drop of free GSH induces an increase of reactive oxygen species (KE3 ) generated by the natural cellular metabolic processes (cellular respiration) of the organism. Increased levels of these reactive species, in turn, induce an increase of lipid peroxidation (KE4 ). This KE consequently leads to a rise in the amount of toxic substances, such as malondialdehyde and hydroxynonenal, which are associated with decreased quality and competence of gamete cell division, consequently impairing fertility (KE5 and adverse outcome). The overall assessment of the general biological plausibility, the empirical support, and the essentiality of KE relationships was considered as high for this AOP. We conclude that GSH conjugation is able to lead to reproductive disorder in fishes and mammals, via OS, but that the amount of stressor needed to trigger the AOP differs between stressors. Environ Toxicol Chem 2023;42:2519-2528. © 2023 SETAC.


Assuntos
Rotas de Resultados Adversos , Animais , Estresse Oxidativo , Espécies Reativas de Oxigênio , Peixes , Glutationa , Medição de Risco , Mamíferos
14.
Toxics ; 11(8)2023 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-37624215

RESUMO

Organophosphate pesticides (OPs) are toxic substances that contaminate aquatic environments, interfere with the development of the nervous system, and induce Neurodevelopmental Toxicity (NDT) in animals and humans. The canonical mechanism of OP neurotoxicity involves the inhibition of acetylcholinesterase (AChE), but other mechanisms non-AChE are also involved and not fully understood. We used network toxicology and molecular docking to identify molecular targets and toxicity mechanisms common to OPs. Targets related to diazinon-oxon, chlorpyrifos oxon, and paraoxon OPs were predicted using the Swiss Target Prediction and PharmMapper databases. Targets related to NDT were compiled from GeneCards and OMIM databases. In order to construct the protein-protein interaction (PPI) network, the common targets between OPs and NDT were imported into the STRING. Network topological analyses identified EGFR, MET, HSP90AA1, and SRC as hub nodes common to the three OPs. Using the Reactome pathway and gene ontology, we found that signal transduction, axon guidance, cellular responses to stress, and glutamatergic signaling activation play key roles in OP-induced NDT.

15.
CPT Pharmacometrics Syst Pharmacol ; 12(10): 1511-1528, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37621010

RESUMO

We have built a quantitative systems toxicology modeling framework focused on the early prediction of oncotherapeutic-induced clinical intestinal adverse effects. The model describes stem and progenitor cell dynamics in the small intestinal epithelium and integrates heterogeneous epithelial-related processes, such as transcriptional profiles, citrulline kinetics, and probability of diarrhea. We fitted a mouse-specific version of the model to quantify doxorubicin and 5-fluorouracil (5-FU)-induced toxicity, which included pharmacokinetics and 5-FU metabolism and assumed that both drugs led to cell cycle arrest and apoptosis in stem cells and proliferative progenitors. The model successfully recapitulated observations in mice regarding dose-dependent disruption of proliferation which could lead to villus shortening, decrease of circulating citrulline, increased diarrhea risk, and transcriptional induction of the p53 pathway. Using a human-specific epithelial model, we translated the cytotoxic activity of doxorubicin and 5-FU quantified in mice into human intestinal injury and predicted with accuracy clinical diarrhea incidence. However, for gefitinib, a specific-molecularly targeted therapy, the mice failed to reproduce epithelial toxicity at exposures much higher than those associated with clinical diarrhea. This indicates that, regardless of the translational modeling approach, preclinical experimental settings have to be suitable to quantify drug-induced clinical toxicity with precision at the structural scale of the model. Our work demonstrates the usefulness of translational models at early stages of the drug development pipeline to predict clinical toxicity and highlights the importance of understanding cross-settings differences in toxicity when building these approaches.


Assuntos
Citrulina , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Camundongos , Humanos , Animais , Fluoruracila/toxicidade , Fluoruracila/metabolismo , Mucosa Intestinal/metabolismo , Diarreia/induzido quimicamente , Doxorrubicina/toxicidade
16.
Nat Commun ; 14(1): 3074, 2023 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-37244912

RESUMO

Paediatric rhabdomyosarcoma (RMS) is a soft tissue malignancy of mesenchymal origin that is thought to arise as a consequence of derailed myogenic differentiation. Despite intensive treatment regimens, the prognosis for high-risk patients remains dismal. The cellular differentiation states underlying RMS and how these relate to patient outcomes remain largely elusive. Here, we use single-cell mRNA sequencing to generate a transcriptomic atlas of RMS. Analysis of the RMS tumour niche reveals evidence of an immunosuppressive microenvironment. We also identify a putative interaction between NECTIN3 and TIGIT, specific to the more aggressive fusion-positive (FP) RMS subtype, as a potential cause of tumour-induced T-cell dysfunction. In malignant RMS cells, we define transcriptional programs reflective of normal myogenic differentiation and show that these cellular differentiation states are predictive of patient outcomes in both FP RMS and the less aggressive fusion-negative subtype. Our study reveals the potential of therapies targeting the immune microenvironment of RMS and suggests that assessing tumour differentiation states may enable a more refined risk stratification.


Assuntos
Rabdomiossarcoma Embrionário , Rabdomiossarcoma , Criança , Humanos , Transcriptoma , Proliferação de Células/genética , Rabdomiossarcoma/genética , Rabdomiossarcoma/patologia , Perfilação da Expressão Gênica , Linhagem Celular Tumoral , Microambiente Tumoral/genética
17.
Noncoding RNA Res ; 7(2): 106-113, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35415316

RESUMO

Aims: Anthracyclines (ANTs) are essential chemotherapeutic agents; however, their adverse effects can lead to heart failure in cancer survivors. While long non-coding RNAs (lncRNAs) have become new players in cellular processes, there is limited knowledge on lncRNA expression related to anthracyclines-induced cardiotoxicity. This study investigates the lncRNA profiles in human cardiac microtissues exposed to 3 popular ANTs, namely doxorubicin, epirubicin, and idarubicin, as well as in heart biopsies from ANT-treated patients. Methods and results: The in vitro microtissues were exposed to each ANT at 2 doses over 2 weeks; the transcriptome data was collected at 7 time points. The human biopsies were collected from heart failure patients who underwent ANT treatment and control subjects. Over 100 lncRNAs were differentially expressed in each in vitro ANT treatment condition compared to control samples; 16 of them were differentially expressed across all ANT-treated conditions. The lncRNA databases and literature revealed insight on how these lncRNAs relate to heart failure and cellular functions. For instance, H19 and RMRP are involved in heart failure progression, while BDNF-AS is a cardiomyocyte damage-associated gene; SNHG7 is a cardiac hypertrophy regulator. PCAT19 can promote the miR-182/PDK4 axis and modulate p53 expression, whereas SNHG29 can regulate the Wnt/ß-catenin signaling pathway via the miR-223-3p/CTNND1 axis. Other lncRNAs, which were only differentially expressed in particular ANT-treated conditions, are also involved in cardiomyocyte damage and heart failure disease. The alterations of these lncRNA expressions in the in vitro cardiac tissue were also affirmed by similar changes in the human biopsies. Conclusion: This study revealed several lncRNAs that can be potential biomarkers or targets for further ANT-induced cardiotoxicity investigation, according to the transcriptome in both human cardiac microtissues expose to ANTs as well as in heart biopies form ANT-treated patients. Especially, H19 lncRNA showed its contribution to on-target toxicity, in which it is involved in both chemoresistance and cardiotoxic mechanism.

18.
EMBO Mol Med ; 14(10): e16001, 2022 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-35916583

RESUMO

Rhabdomyosarcomas (RMS) are mesenchyme-derived tumors and the most common childhood soft tissue sarcomas. Treatment is intense, with a nevertheless poor prognosis for high-risk patients. Discovery of new therapies would benefit from additional preclinical models. Here, we describe the generation of a collection of 19 pediatric RMS tumor organoid (tumoroid) models (success rate of 41%) comprising all major subtypes. For aggressive tumors, tumoroid models can often be established within 4-8 weeks, indicating the feasibility of personalized drug screening. Molecular, genetic, and histological characterization show that the models closely resemble the original tumors, with genetic stability over extended culture periods of up to 6 months. Importantly, drug screening reflects established sensitivities and the models can be modified by CRISPR/Cas9 with TP53 knockout in an embryonal RMS model resulting in replicative stress drug sensitivity. Tumors of mesenchymal origin can therefore be used to generate organoid models, relevant for a variety of preclinical and clinical research questions.


Assuntos
Organoides , Rabdomiossarcoma , Criança , Humanos , Organoides/patologia , Rabdomiossarcoma/diagnóstico , Rabdomiossarcoma/patologia
19.
An Acad Bras Cienc ; 83(3): 1045-58, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21779655

RESUMO

This study assessed the antiproliferative and cytotoxic potential against tumor lines of ethanolic seed extracts of 21 plant species belonging to different families from Northeastern Brazil. In addition, some underlying mechanisms involved in this cytotoxicity were also investigated. Among the 21 extracts tested, the MTT assay after 72 h of incubation demonstrated that only the ethanolic extract obtained from Myracrodruon urundeuva seeds (EEMUS), which has steroids, alkaloids and phenols, showed in vitro cytotoxic activity against human cancer cells, being 2-fold more active on leukemia HL-60 line [IC(50) value of 12.5 (9.5-16.7) µg/mL] than on glioblastoma SF-295 [IC(50) of 25.1 (17.3-36.3) µg/mL] and Sarcoma 180 cells [IC(50) of 38.1 (33.5-43.4) µg/mL]. After 72h exposure, flow cytometric and morphological analyses of HL-60-treated cells showed that EEMUS caused decrease in cell number, volume and viability as well as internucleosomal DNA fragmentation in a dose-dependent way, suggesting that the EEMUS triggers apoptotic pathways of cell death.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Animais , Brasil , Linhagem Celular Tumoral/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Citometria de Fluxo , Humanos , Camundongos , Plantas Medicinais/classificação , Sementes/química
20.
Toxicol Lett ; 350: 40-51, 2021 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-34229068

RESUMO

In recent years, network-based methods have become an attractive analytical approach for toxicogenomics studies. They can capture not only the global changes of regulatory gene networks but also the relationships between their components. Among them, a causal reasoning approach depicts the mechanisms of regulation that connect upstream regulators in signaling networks to their downstream gene targets. In this work, we applied CARNIVAL, a causal network contextualisation tool, to infer upstream signaling networks deregulated in drug-induced liver injury (DILI) from gene expression microarray data from the TG-GATEs database. We focussed on six compounds that induce observable histopathologies linked to DILI from repeated dosing experiments in rats. We compared responses in vitro and in vivo to identify potential cross-platform concordances in rats as well as network preservations between rat and human. Our results showed similarities of enriched pathways and network motifs between compounds. These pathways and motifs induced the same pathology in rats but not in humans. In particular, the causal interactions "LCK activates SOCS3, which in turn inhibits TFDP1" was commonly identified as a regulatory path among the fibrosis-inducing compounds. This potential pathology-inducing regulation illustrates the value of our approach to generate hypotheses that can be further validated experimentally.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/genética , Doença Hepática Induzida por Substâncias e Drogas/patologia , Perfilação da Expressão Gênica/métodos , Redes Reguladoras de Genes/fisiologia , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Toxicogenética , Animais , Humanos , Modelos Animais , Ratos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA