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1.
Anticancer Res ; 40(11): 6123-6135, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33109550

RESUMO

BACKGROUND/AIM: The importance of hadron therapy in the cancer management is growing. We aimed to refine the biological effect detection using a vertebrate model. MATERIALS AND METHODS: Embryos at 24 and 72 h postfertilization were irradiated at the entrance plateau and the mid spread-out Bragg peak of a 150 MeV proton beam and with reference photons. Radiation-induced DNA double-strand breaks (DSB) and histopathological changes of the eye, muscles and brain were evaluated; deterioration of specific organs (eye, yolk sac, body) was measured. RESULTS: More and longer-lasting DSBs occurred in eye and muscle cells due to proton versus photon beams, albeit in different numbers. Edema, necrosis and tissue disorganization, (especially in the eye) were observed. Dose-dependent morphological deteriorations were detected at ≥10 Gy dose levels, with relative biological effectiveness between 0.99±0.07 (length) and 1.12±0.19 (eye). CONCLUSION: Quantitative assessment of radiation induced changes in zebrafish embryos proved to be beneficial for the radiobiological characterization of proton beams.


Assuntos
Fótons , Prótons , Peixe-Zebra/fisiologia , Animais , Encéfalo/efeitos da radiação , Dano ao DNA , Modelos Animais de Doenças , Relação Dose-Resposta à Radiação , Embrião não Mamífero/efeitos da radiação , Olho/patologia , Olho/efeitos da radiação , Cinética , Tamanho do Órgão/efeitos da radiação , Eficiência Biológica Relativa , Saco Vitelino/patologia , Saco Vitelino/efeitos da radiação , Peixe-Zebra/embriologia
2.
Nat Commun ; 11(1): 5476, 2020 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-33127887

RESUMO

The formation of vascular tubes is driven by extensive changes in endothelial cell (EC) shape. Here, we have identified a role of the actin-binding protein, Marcksl1, in modulating the mechanical properties of EC cortex to regulate cell shape and vessel structure during angiogenesis. Increasing and depleting Marcksl1 expression level in vivo results in an increase and decrease, respectively, in EC size and the diameter of microvessels. Furthermore, endothelial overexpression of Marcksl1 induces ectopic blebbing on both apical and basal membranes, during and after lumen formation, that is suppressed by reduced blood flow. High resolution imaging reveals that Marcksl1 promotes the formation of linear actin bundles and decreases actin density at the EC cortex. Our findings demonstrate that a balanced network of linear and branched actin at the EC cortex is essential in conferring cortical integrity to resist the deforming forces of blood flow to regulate vessel structure.


Assuntos
Vasos Sanguíneos/anatomia & histologia , Vasos Sanguíneos/fisiologia , Proteínas de Ligação a Calmodulina/metabolismo , Células Endoteliais/metabolismo , Hemodinâmica/fisiologia , Proteínas dos Microfilamentos/metabolismo , Actinas/metabolismo , Actomiosina/metabolismo , Animais , Animais Geneticamente Modificados , Vasos Sanguíneos/citologia , Proteínas de Ligação a Calmodulina/genética , Células Endoteliais/citologia , Regulação da Expressão Gênica no Desenvolvimento , Proteínas dos Microfilamentos/genética , Modelos Animais , Transcriptoma , Peixe-Zebra/embriologia
3.
Nat Commun ; 11(1): 5319, 2020 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-33087700

RESUMO

Arterial networks enlarge in response to increase in tissue metabolism to facilitate flow and nutrient delivery. Typically, the transition of a growing artery with a small diameter into a large caliber artery with a sizeable diameter occurs upon the blood flow driven change in number and shape of endothelial cells lining the arterial lumen. Here, using zebrafish embryos and endothelial cell models, we describe an alternative, flow independent model, involving enlargement of arterial endothelial cells, which results in the formation of large diameter arteries. Endothelial enlargement requires the GEF1 domain of the guanine nucleotide exchange factor Trio and activation of Rho-GTPases Rac1 and RhoG in the cell periphery, inducing F-actin cytoskeleton remodeling, myosin based tension at junction regions and focal adhesions. Activation of Trio in developing arteries in vivo involves precise titration of the Vegf signaling strength in the arterial wall, which is controlled by the soluble Vegf receptor Flt1.


Assuntos
Células Endoteliais/citologia , Células Endoteliais/fisiologia , Fatores de Troca do Nucleotídeo Guanina/fisiologia , Fator A de Crescimento do Endotélio Vascular/fisiologia , Remodelação Vascular/fisiologia , Animais , Animais Geneticamente Modificados , Tamanho Celular , Células Cultivadas , Fatores de Troca do Nucleotídeo Guanina/genética , Células Endoteliais da Veia Umbilical Humana , Humanos , Modelos Cardiovasculares , Fator de Crescimento Placentário/genética , Fator de Crescimento Placentário/fisiologia , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/fisiologia , Transdução de Sinais , Fator A de Crescimento do Endotélio Vascular/genética , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/fisiologia , Remodelação Vascular/genética , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Peixe-Zebra/fisiologia , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/fisiologia , Proteínas rac1 de Ligação ao GTP/genética , Proteínas rac1 de Ligação ao GTP/fisiologia
4.
Chemosphere ; 254: 126608, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957262

RESUMO

Al2O3 Nanoparticles (Al2O3-NPs) have been widely used because of their unique physical and chemical properties, and Al2O3-NPs can be released into the environment directly or indirectly. Our previous research found that 13 nm Al2O3-NPs can induce neural cell death and autophagy in primarily cultured neural cells in vitro. The aim of this study was to determine where Al2O3-NPs at 13 nm particle size can cause neural cells in vivo and assess related behavioural changes and involved potential mechanisms. Zebrafish from embryo to adult were selected as animal models. Learning and memory as functional indicators of neural cells in zebrafish were measured during the development from embryo to adult. Our results indicate that Al2O3-NPs treatment in zebrafish embryos stages can cause the accumulation of aluminium content in zebrafish brain tissue, leading to progressive impaired neurodevelopmental behaviours and latent learning and memory performance. Additionally, oxidative stress and disruption of dopaminergic transmission in zebrafish brain tissues are correlated with the dose-dependent and age-dependent accumulation of aluminium content. Moreover, the number of neural cells in the telencephalon tissue treated with Al2O3-NPs significantly declined, and the ultramicroscopic morphology indicated profound autophagy alternations. The results suggest that Al2O3-NPs has dose-dependent and time-dependent progressive damage on learning and memory performance in adult zebrafish when treated in embryos. This is the first study of the effects of Al2O3-NPs on learning and memory during the development of zebrafish from embryo to adult.


Assuntos
Óxido de Alumínio/toxicidade , Aprendizagem/efeitos dos fármacos , Memória/efeitos dos fármacos , Nanopartículas/toxicidade , Alumínio/farmacologia , Óxido de Alumínio/química , Animais , Embrião não Mamífero , Nanopartículas Metálicas , Estresse Oxidativo/efeitos dos fármacos , Tamanho da Partícula , Peixe-Zebra/embriologia
5.
Chemosphere ; 254: 126792, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957266

RESUMO

Iron oxide nanoparticles (IONPs) are used in several medical and environmental applications, but their mechanism of action and hazardous effects to early developmental stages of fish remain unknown. Thus, the present study aimed to assess the developmental toxicity of citrate-functionalized IONPs (γ-Fe2O3 NPs), in comparison with its dissolved counterpart, in zebrafish (Danio rerio) after static and semi-static exposure. Embryos were exposed to environmental concentrations of both iron forms (0.3, 0.6, 1.25, 2.5, 5 and 10 mg L-1) during 144 h, jointly with negative control group. The interaction and distribution of both Fe forms on the external chorion and larvae surface were measured, following by multiple biomarker assessment (mortality, hatching rate, neurotoxicity, cardiotoxicity, morphological alterations and 12 morphometrics parameters). Results showed that IONPs were mainly accumulated on the zebrafish chorion, and in the digestive system and liver of the larvae. Although the IONPs induced low embryotoxicity compared to iron ions in both exposure conditions, these nanomaterials induced sublethal effects, mainly cardiotoxic effects (reduced heartbeat, blood accumulation in the heart and pericardial edema). The semi-static exposure to both iron forms induced high embryotoxicity compared to static exposure, indicating that the nanotoxicity to early developmental stages of fish depends on the exposure system. This is the first study concerning the role of the exposure condition on the developmental toxicity of IONPs on fish species.


Assuntos
Compostos Férricos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Cloretos , Embrião não Mamífero/efeitos dos fármacos , Ferro/farmacologia , Larva/efeitos dos fármacos , Nanopartículas/toxicidade , Peixe-Zebra/embriologia
6.
Ecotoxicol Environ Saf ; 202: 110936, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800219

RESUMO

Developmental toxicity refers to the occurrence of adverse effects on a developing organism as a consequence of exposure to hazardous chemicals. The assessment of developmental toxicity has become relevant to the safety assessment process of chemicals. The zebrafish embryo developmental toxicology assay is an emerging test used to screen the teratogenic potential of chemicals and it is proposed as a promising test to replace teratogenic assays with animals. Supported by the increased availability of data from this test, the developmental toxicity assay with zebrafish has become an interesting endpoint for the in silico modelling. The purpose of this study was to build up quantitative structure-activity relationship (QSAR) models. In this work, new in silico models for the evaluation of developmental toxicity were built using a well-defined set of data from the ToxCastTM Phase I chemical library on the zebrafish embryo. Categorical and continuous QSAR models were built by gradient boosting machine learning and the Monte Carlo technique respectively, in accordance with Organization for Economic Co-operation and Development principles and their statistical quality was satisfactory. The classification model reached balanced accuracy 0.89 and Matthews correlation coefficient 0.77 on the test set. The regression model reached correlation coefficient R2 0.70 in external validation and leave-one-out cross-validated Q2 0.73 in internal validation.


Assuntos
Embrião não Mamífero/efeitos dos fármacos , Testes de Toxicidade/métodos , Poluentes Químicos da Água/toxicidade , Animais , Simulação por Computador , Substâncias Perigosas , Aprendizado de Máquina , Relação Quantitativa Estrutura-Atividade , Teratogênios , Peixe-Zebra/embriologia
7.
Nat Commun ; 11(1): 3920, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32764605

RESUMO

How the genome activates or silences transcriptional programmes governs organ formation. Little is known in human embryos undermining our ability to benchmark the fidelity of stem cell differentiation or cell programming, or interpret the pathogenicity of noncoding variation. Here, we study histone modifications across thirteen tissues during human organogenesis. We integrate the data with transcription to build an overview of how the human genome differentially regulates alternative organ fates including by repression. Promoters from nearly 20,000 genes partition into discrete states. Key developmental gene sets are actively repressed outside of the appropriate organ without obvious bivalency. Candidate enhancers, functional in zebrafish, allow imputation of tissue-specific and shared patterns of transcription factor binding. Overlaying more than 700 noncoding mutations from patients with developmental disorders allows correlation to unanticipated target genes. Taken together, the data provide a comprehensive genomic framework for investigating normal and abnormal human development.


Assuntos
Deficiências do Desenvolvimento/genética , Epigênese Genética , Organogênese/genética , Animais , Animais Geneticamente Modificados , Bases de Dados Genéticas , Elementos Facilitadores Genéticos , Regulação da Expressão Gênica no Desenvolvimento , Código das Histonas/genética , Humanos , Modelos Genéticos , Mutação , Organogênese/fisiologia , Regiões Promotoras Genéticas , Distribuição Tecidual , Fatores de Transcrição/metabolismo , Peixe-Zebra/embriologia , Peixe-Zebra/genética
8.
J Vis Exp ; (162)2020 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-32831299

RESUMO

There are many endocrine disrupting compounds (EDC) in the environment, especially estrogenic substances. The detection of these substances is difficult due to their chemical diversity; therefore, increasingly more effect-detecting methods are used, such as estrogenic effect-sensitive biomonitor/bioindicator organisms. These biomonitoring organisms include several fish models. This protocol covers the use of zebrafish Tg(vtg1: mCherry) transgenic line as a biomonitoring organism, including the propagation of fish and the treatment of embryos, with an emphasis on the detection, documentation, and evaluation of fluorescent signals induced by EDC. The goal of the work is the demonstration of the use of the Tg(vtg1: mCherry) transgenic line embryos to detect estrogenic effects. This work documents the use of transgenic zebrafish embryos Tg(vtg1: mCherry) for the detection of estrogenic effects by testing two estrogenic substances, α- and ß-zearalenol. The described protocol is only a basis for designing assays; the test method can be varied according to the test endpoints and the samples. Moreover, it can be combined with other assay methods, thereby facilitating the future use of the transgenic line.


Assuntos
Bioensaio/métodos , Disruptores Endócrinos/farmacologia , Estrogênios/farmacologia , Animais , Animais Geneticamente Modificados , Monitoramento Biológico , Embrião não Mamífero/efeitos dos fármacos , Peixe-Zebra/embriologia
9.
Int J Nanomedicine ; 15: 4091-4104, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32606666

RESUMO

Introduction: Humans are intentionally exposed to gold nanoparticles (AuNPs) where they are used in variety of biomedical applications as imaging and drug delivery agents as well as diagnostic and therapeutic agents currently in clinic and in a variety of upcoming clinical trials. Consequently, it is critical that we gain a better understanding of how physiochemical properties such as size, shape, and surface chemistry drive cellular uptake and AuNP toxicity in vivo. Understanding and being able to manipulate these physiochemical properties will allow for the production of safer and more efficacious use of AuNPs in biomedical applications. Methods and Materials: Here, AuNPs of three sizes, 5 nm, 10 nm, and 20 nm, were coated with a lipid bilayer composed of sodium oleate, hydrogenated phosphatidylcholine, and hexanethiol. To understand how the physical features of AuNPs influence uptake through cellular membranes, sum frequency generation (SFG) was utilized to assess the interactions of the AuNPs with a biomimetic lipid monolayer composed of a deuterated phospholipid 1.2-dipalmitoyl-d62-sn-glycero-3-phosphocholine (dDPPC). Results and Discussion: SFG measurements showed that 5 nm and 10 nm AuNPs are able to phase into the lipid monolayer with very little energetic cost, whereas, the 20 nm AuNPs warped the membrane conforming it to the curvature of hybrid lipid-coated AuNPs. Toxicity of the AuNPs were assessed in vivo to determine how AuNP curvature and uptake influence cell health. In contrast, in vivo toxicity tested in embryonic zebrafish showed rapid toxicity of the 5 nm AuNPs, with significant 24 hpf mortality occurring at concentrations ≥20 mg/L, whereas the 10 nm and 20 nm AuNPs showed no significant mortality throughout the five-day experiment. Conclusion: By combining information from membrane models using SFG spectroscopy with in vivo toxicity studies, a better mechanistic understanding of how nanoparticles (NPs) interact with membranes is developed to understand how the physiochemical features of AuNPs drive nanoparticle-membrane interactions, cellular uptake, and toxicity.


Assuntos
Membrana Celular/química , Ouro/toxicidade , Lipídeos/química , Membranas Artificiais , Nanopartículas Metálicas/toxicidade , Tamanho da Partícula , Testes de Toxicidade , Animais , Embrião não Mamífero/anormalidades , Embrião não Mamífero/efeitos dos fármacos , Humanos , Espectrofotometria Ultravioleta , Análise Espectral , Peixe-Zebra/embriologia
10.
Int J Nanomedicine ; 15: 4407-4415, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32606685

RESUMO

Objective: Silica nanoparticles (SiO2 NPs) have been extensively employed in biomedical field. SiO2 NPs are primarily designed to enter the circulatory system; however, little information is available on potential adverse effects of SiO2 NPs on the nervous system. Methods: The neurotoxicity of SiO2 NPs at different concentrations (3, 6, 12 ng/nL) on zebrafish embryos was determined using immunofluorescence and microarray techniques, and subsequently confirmed by qRT-PCR. Results: SiO2 NPs disrupt the axonal integrity and decrease the length of axons in Tg (NBT: EGFP) transgenic lines. The number of apoptotic cells in the brain and central nervous system of zebrafish embryos was increased in the presence of 12 ng/nL of SiO2 NPs, but the difference did not reach statistical significance. Screening for changes in the expression of genes involved in the neuroactive ligand-receptor interaction pathway was performed by microarray and confirmed by qRT-PCR. These analyses demonstrated that SiO2 NPs markedly downregulated genes associated with neural function (grm6a, drd1b, chrnb3b, adrb2a, grin2ab, npffr2.1, npy8br, gabrd, chrma3, gabrg3, gria3a, grm1a, adra2b, and glra3). Conclusion: The obtained results documented that SiO2 NPs can induce developmental neurotoxicity by affecting the neuroactive ligand-receptor interaction signaling pathway. This new evidence may help to clarify the mechanism of SiO2 NPs-mediated neurotoxicity.


Assuntos
Embrião não Mamífero/metabolismo , Nanopartículas/toxicidade , Neurotoxinas/toxicidade , Receptores de Superfície Celular/metabolismo , Transdução de Sinais , Dióxido de Silício/toxicidade , Peixe-Zebra/embriologia , Animais , Apoptose/efeitos dos fármacos , Embrião não Mamífero/efeitos dos fármacos , Ligantes , Transdução de Sinais/efeitos dos fármacos
11.
PLoS One ; 15(7): e0232559, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32658922

RESUMO

PRESENILIN 2 (PSEN2) is one of the genes mutated in early onset familial Alzheimer's disease (EOfAD). PSEN2 shares significant amino acid sequence identity with another EOfAD-related gene PRESENILIN 1 (PSEN1), and partial functional redundancy is seen between these two genes. However, the complete range of functions of PSEN1 and PSEN2 is not yet understood. In this study, we performed targeted mutagenesis of the zebrafish psen2 gene to generate a premature termination codon close downstream of the translation start with the intention of creating a null mutation. Homozygotes for this mutation, psen2S4Ter, are viable and fertile, and adults do not show any gross psen2-dependent pigmentation defects, arguing against significant loss of γ-secretase activity. Also, assessment of the numbers of Dorsal Longitudinal Ascending (DoLA) interneurons that are responsive to psen2 but not psen1 activity during embryogenesis did not reveal decreased psen2 function. Transcripts containing the S4Ter mutation show no evidence of destabilization by nonsense-mediated decay. Forced expression in zebrafish embryos of fusions of psen2S4Ter 5' mRNA sequences with sequence encoding enhanced green fluorescent protein (EGFP) indicated that the psen2S4Ter mutation permits utilization of cryptic, novel downstream translation start codons. These likely initiate translation of N-terminally truncated Psen2 proteins lacking late endosomal/lysosomal localization sequences and that obey the "reading frame preservation rule" of PRESENILIN EOfAD mutations. Transcriptome analysis of entire brains from a 6-month-old family of wild type, heterozygous and homozygous psen2S4Ter female siblings revealed profoundly dominant effects on gene expression likely indicating changes in ribosomal, mitochondrial, and anion transport functions.


Assuntos
Códon de Terminação/genética , Perfilação da Expressão Gênica , Mitocôndrias/genética , Mutação , Presenilina-2/genética , Ribossomos/genética , Proteínas de Peixe-Zebra/genética , Alelos , Animais , Contagem de Células , Homozigoto , Hipóxia/genética , Neurônios/citologia , Estabilidade de RNA/genética , Peixe-Zebra/embriologia , Peixe-Zebra/genética
12.
Chem Biol Interact ; 328: 109193, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32668205

RESUMO

Embryonic studies have demonstrated the neurotoxic, teratogenic, and neurobehavioral toxicity of ethanol (EtOH). Although multiple mechanisms may contribute to these effects, oxidative stress has been described as the major damage pathway. In this regard, natural antioxidants have the potential to counteract oxidative stress-induced cellular damage. Therefore, the present study aimed to investigate the potential protective role of 24-epibrassinolide (24-EPI), a natural brassinosteroid with proved antioxidant properties, in EtOH-induced teratogenic effects during early zebrafish development. Embryos (~2 h post-fertilization - hpf) were exposed to 1 % EtOH, co-exposed to 24-EPI (0.01, 0.1 and 1 µM) and to 24-EPI alone (1 µM) for 24 h. Following exposure, biochemical evaluations were made at 26 hpf, developmental analysis was made throughout the embryo-larval period, and behavioural responses were evaluated at 120 hpf. Exposure to 1 % EtOH caused an increase in the number of malformations, which were diminished by 24-EPI. In addition, EtOH induced an accumulation of GSSG and consequent reduction of GSH:GSSG ratio, indicating the involvement of oxidative mechanisms in the EtOH-induced effects. These were reverted by 24-EPI as proved by the GSSG levels and GSH:GSSG ratio that returned to control values. Furthermore, exposure to EtOH resulted in behavioural deficits at 120 hpf as observed by the disrupted response to an aversive stimulus, suggesting the involvement of neurotoxic mechanisms. 24-EPI restored the behavioural deficits observed in a dose-dependent manner. The absence of effects in the embryos exposed solely to 24-EPI showed its safety during the exposure period. In conclusion, EtOH caused developmental teratogenicity and behavioural toxicity by inducing glutathione changes, which were prevented by 24-EPI.


Assuntos
Comportamento Animal , Brassinosteroides/farmacologia , Embrião não Mamífero/patologia , Etanol/toxicidade , Substâncias Protetoras/farmacologia , Esteroides Heterocíclicos/farmacologia , Teratogênese/efeitos dos fármacos , Peixe-Zebra/embriologia , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Embrião não Mamífero/anormalidades , Embrião não Mamífero/efeitos dos fármacos , Glutationa/metabolismo , Larva/efeitos dos fármacos , Comportamento Social
13.
PLoS One ; 15(7): e0235869, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645106

RESUMO

The rapid deployment of 5G spectrum by the telecommunication industry is intended to promote better connectivity and data integration among various industries. However, since exposures to radio frequency radiations (RFR) >2.4 GHz are still uncommon, concerns about their potential health impacts are ongoing. In this study, we used the embryonic zebrafish model to assess the impacts of a 3.5 GHz RFR on biology- a frequency typically used by 5G-enabled cell phones and lies within the 4G and 5G bandwidth. We established a plate-based exposure setup for RFRs, exposed developing zebrafish to 3.5 GHz RFR, specific absorption rate (SAR) ≈ 8.27 W/Kg from 6 h post fertilization (hpf) to 48 hpf, and measured a battery of morphological and behavioral endpoints at 120 hpf. Our results revealed no significant impacts on mortality, morphology or photomotor response and a modest inhibition of startle response suggesting some levels of sensorimotor disruptions. This suggests that the cell phone radiations at low GHz-level frequencies are likely benign, with subtle sensorimotor effects. Through this assessment, we have established a robust setup for zebrafish RFR exposures readily amenable to testing various powers and frequencies. Future developmental exposure studies in zebrafish will evaluate a wider portion of the radio frequency spectrum to discover the bioactive regions, the potential molecular targets of RFR and the potential long-term effects on adult behavior.


Assuntos
Desenvolvimento Embrionário/efeitos da radiação , Ondas de Rádio/efeitos adversos , Peixe-Zebra/embriologia , Animais , Telefone Celular , Feminino , Masculino , Reflexo de Sobressalto/efeitos da radiação
14.
Chemosphere ; 259: 127380, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32634720

RESUMO

Fomesafen is widely used in agriculture and can be detected in the environment and agricultural products. Research on the developmental toxicity of fomesafen in animals is currently very limited. Here, we used zebrafish as an animal model to evaluate the toxicity of fomesafen in developing aquatic vertebrates and higher animals. From 6h to 72h following fertilization, exposure of zebrafish embryos to 5, 10 and 20 mg/L of fomesafen resulted in pericardial edema, a reduction in heart rate, shortening of body length, and yolk sac edema. Fomesafen reduced the number of immune cells such as neutrophils and macrophages, increased the expression of a number of inflammatory factors, induced the up-regulation of the oxidative stress response and apoptosis, and disrupted the activity of enzymes related to nerve development, which affected the motility of the embryos. In conclusion, the results provide new evidence for the comprehensive assessment of fomesafen toxicity in aquatic vertebrates.


Assuntos
Benzamidas/toxicidade , Embrião não Mamífero/efeitos dos fármacos , Desenvolvimento Embrionário/efeitos dos fármacos , Herbicidas/toxicidade , Animais , Apoptose/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Regulação para Cima , Peixe-Zebra/embriologia , Peixe-Zebra/metabolismo
15.
PLoS Biol ; 18(7): e3000561, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32702011

RESUMO

Maternal ß-catenin activity is essential and critical for dorsal induction and its dorsal activation has been thoroughly studied. However, how the maternal ß-catenin activity is suppressed in the nondorsal cells remains poorly understood. Nanog is known to play a central role for maintenance of the pluripotency and maternal -zygotic transition (MZT). Here, we reveal a novel role of Nanog as a strong repressor of maternal ß-catenin signaling to safeguard the embryo against hyperactivation of maternal ß-catenin activity and hyperdorsalization. In zebrafish, knockdown of nanog at different levels led to either posteriorization or dorsalization, mimicking zygotic or maternal activation of Wnt/ß-catenin activities, and the maternal zygotic mutant of nanog (MZnanog) showed strong activation of maternal ß-catenin activity and hyperdorsalization. Although a constitutive activator-type Nanog (Vp16-Nanog, lacking the N terminal) perfectly rescued the MZT defects of MZnanog, it did not rescue the phenotypes resulting from ß-catenin signaling activation. Mechanistically, the N terminal of Nanog directly interacts with T-cell factor (TCF) and interferes with the binding of ß-catenin to TCF, thereby attenuating the transcriptional activity of ß-catenin. Therefore, our study establishes a novel role for Nanog in repressing maternal ß-catenin activity and demonstrates a transcriptional switch between ß-catenin/TCF and Nanog/TCF complexes, which safeguards the embryo from global activation of maternal ß-catenin activity.


Assuntos
Desenvolvimento Embrionário/genética , Proteína Homeobox Nanog/metabolismo , Transativadores/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/embriologia , Peixe-Zebra/genética , beta Catenina/metabolismo , Animais , Padronização Corporal/genética , Núcleo Celular/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Silenciamento de Genes , Masculino , Mutação/genética , Proteína Homeobox Nanog/química , Proteína Homeobox Nanog/genética , Ligação Proteica , Transporte Proteico , Proteínas Repressoras/metabolismo , Transcrição Genética , Via de Sinalização Wnt/genética , Proteínas de Peixe-Zebra/química , Proteínas de Peixe-Zebra/genética , Zigoto/metabolismo
16.
F1000Res ; 92020.
Artigo em Inglês | MEDLINE | ID: mdl-32528656

RESUMO

Early animal development is characterized by intense reorganization of the embryonic genome, including large-scale changes in chromatin structure and in the DNA and histone modifications that help shape this structure. Particularly profound shifts in the chromatin landscape are associated with the maternal-to-zygotic transition, when the zygotic genome is first transcribed and maternally loaded transcripts are degraded. The accessibility of the early zebrafish embryo facilitates the interrogation of chromatin during this critical window of development, making it an important model for early chromatin regulation. Here, we review our current understanding of chromatin dynamics during early zebrafish development, highlighting new advances as well as similarities and differences between early chromatin regulation in zebrafish and other species.


Assuntos
Cromatina/genética , Embrião não Mamífero , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Peixe-Zebra , Peixe-Zebra/embriologia , Animais , Zigoto
17.
Chemosphere ; 257: 127170, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32497837

RESUMO

Ammonia (including NH3 and NH4+) is a major pollutant of freshwater environments. However, the toxic effects of ammonia on the early stages of fish are not fully understood, and little is known about the effects on the sensory system. In this study, we hypothesized that ammonia exposure can cause adverse effects on embryonic development and impair the lateral line system of fish. Zebrafish embryos were exposed to high-ammonia water (10, 15, 20, 25, and 30 mM NH4Cl; pH 7.0) for 96 h (0-96 h post-fertilization). The body length, heart rate, and otic vesicle size had significantly decreased with ≥15 mM NH4Cl, while the number and function of lateral-line hair cells had decreased with ≥10 mM NH4Cl. The mechanoelectrical transduction (MET) channel-mediated Ca2+ influx was measured with a scanning ion-selective microelectrode technique to reveal the function of hair cells. We found that NH4+ (≥5 mM NH4Cl) entered hair cells and suppressed the Ca2+ influx of hair cells. Neomycin and La3+ (MET channel blockers) suppressed NH4+ influx, suggesting that NH4+ enters hair cells via MET channels in hair bundles. In conclusion, this study showed that ammonia exposure (≥10 mM NH4Cl) can cause adverse effects in zebrafish embryos, and lateral-line hair cells are sensitive to ammonia exposure.


Assuntos
Amônia/metabolismo , Sistema da Linha Lateral/efeitos dos fármacos , Amônia/toxicidade , Animais , Desenvolvimento Embrionário , Células Ciliadas Auditivas/efeitos dos fármacos , Mecanotransdução Celular/efeitos dos fármacos , Mecanotransdução Celular/fisiologia , Peixe-Zebra/embriologia , Peixe-Zebra/fisiologia
18.
Nat Commun ; 11(1): 2984, 2020 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-32533114

RESUMO

ADNP (Activity Dependent Neuroprotective Protein) is a neuroprotective protein whose aberrant expression has been frequently linked to neural developmental disorders, including the Helsmoortel-Van der Aa syndrome (also called the ADNP syndrome). However, its role in neural development and pathology remains unclear. Here, we show that ADNP is required for neural induction and differentiation by enhancing Wnt signaling. Mechanistically, ADNP functions to stabilize ß-Catenin through binding to its armadillo domain which prevents its association with key components of the degradation complex: Axin and APC. Loss of ADNP promotes the formation of the degradation complex and ß-Catenin degradation via ubiquitin-proteasome pathway, resulting in down-regulation of key neuroectoderm developmental genes. In addition, adnp gene disruption in zebrafish leads to defective neurogenesis and reduced Wnt signaling. Our work provides important insights into the role of ADNP in neural development and the pathology of the Helsmoortel-Van der Aa syndrome caused by ADNP gene mutation.


Assuntos
Diferenciação Celular/genética , Proteínas de Homeodomínio/genética , Células-Tronco Embrionárias Murinas/metabolismo , Proteínas do Tecido Nervoso/genética , Neurônios/metabolismo , Via de Sinalização Wnt/genética , beta Catenina/genética , Animais , Células Cultivadas , Regulação da Expressão Gênica no Desenvolvimento , Células HEK293 , Proteínas de Homeodomínio/metabolismo , Humanos , Hibridização In Situ/métodos , Camundongos , Camundongos Knockout , Células-Tronco Embrionárias Murinas/citologia , Mutação , Proteínas do Tecido Nervoso/metabolismo , Neurônios/citologia , Ligação Proteica , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo , beta Catenina/metabolismo
19.
PLoS Comput Biol ; 16(6): e1007417, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32579554

RESUMO

During embryogenesis, morphogens form a concentration gradient in responsive tissue, which is then translated into a spatial cellular pattern. The mechanisms by which morphogens spread through a tissue to establish such a morphogenetic field remain elusive. Here, we investigate by mutually complementary simulations and in vivo experiments how Wnt morphogen transport by cytonemes differs from typically assumed diffusion-based transport for patterning of highly dynamic tissue such as the neural plate in zebrafish. Stochasticity strongly influences fate acquisition at the single cell level and results in fluctuating boundaries between pattern regions. Stable patterning can be achieved by sorting through concentration dependent cell migration and apoptosis, independent of the morphogen transport mechanism. We show that Wnt transport by cytonemes achieves distinct Wnt thresholds for the brain primordia earlier compared with diffusion-based transport. We conclude that a cytoneme-mediated morphogen transport together with directed cell sorting is a potentially favored mechanism to establish morphogen gradients in rapidly expanding developmental systems.


Assuntos
Padronização Corporal/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Vertebrados/embriologia , Proteínas Wnt/fisiologia , Animais , Apoptose , Encéfalo/embriologia , Linhagem da Célula , Movimento Celular , Biologia Computacional , Simulação por Computador , Desenvolvimento Embrionário , Crista Neural/embriologia , Placa Neural/embriologia , Transporte Proteico , Transdução de Sinais , Software , Processos Estocásticos , Peixe-Zebra/embriologia , beta Catenina/fisiologia
20.
Nat Commun ; 11(1): 2724, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32483144

RESUMO

Proteolytical processing of the growth factor VEGFC through the concerted activity of CCBE1 and ADAMTS3 is required for lymphatic development to occur. How these factors act together in time and space, and which cell types produce these factors is not understood. Here we assess the function of Adamts3 and the related protease Adamts14 during zebrafish lymphangiogenesis and show both proteins to be able to process Vegfc. Only the simultaneous loss of both protein functions results in lymphatic defects identical to vegfc loss-of-function situations. Cell transplantation experiments demonstrate neuronal structures and/or fibroblasts to constitute cellular sources not only for both proteases but also for Ccbe1 and Vegfc. We further show that this locally restricted Vegfc maturation is needed to trigger normal lymphatic sprouting and directional migration. Our data provide a single-cell resolution model for establishing secretion and processing hubs for Vegfc during developmental lymphangiogenesis.


Assuntos
Fibroblastos/metabolismo , Linfangiogênese/genética , Neurônios/metabolismo , Fator C de Crescimento do Endotélio Vascular/genética , Proteínas de Peixe-Zebra/genética , Peixe-Zebra/genética , Proteínas ADAMTS/genética , Proteínas ADAMTS/metabolismo , Animais , Animais Geneticamente Modificados , Regulação da Expressão Gênica no Desenvolvimento , Células HEK293 , Humanos , Vasos Linfáticos/embriologia , Vasos Linfáticos/metabolismo , Microscopia Confocal , Pró-Colágeno N-Endopeptidase/genética , Pró-Colágeno N-Endopeptidase/metabolismo , Fator C de Crescimento do Endotélio Vascular/metabolismo , Peixe-Zebra/embriologia , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/metabolismo
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