Enriched environment prevents oxidative stress in zebrafish submitted to unpredictable chronic stress

Background. The enriched environment (EE) is a laboratory housing model that emerged from efforts to minimize the impact of environmental conditions on laboratory animals. Recently, we showed that EE promoted positive effects on behavior and cortisol levels in zebrafish submitted to the unpredictable chronic stress (UCS) protocol. Here, we expanded the characterization of the effects of UCS protocol by assessing parameters of oxidative status in the zebrafish brain and reveal that EE protects against the oxidative stress induced by chronic stress. Methods. Zebrafish were exposed to EE (21 or 28 days) or standard housing conditions and subjected to the UCS protocol for seven days. Oxidative stress parameters (lipid peroxidation (TBARS), reactive oxygen species (ROS) levels, non-protein thiol (NPSH) and total thiol (SH) levels, superoxide dismutase (SOD) and catalase (CAT) activities were measured in brain homogenate. Results. Our results revealed that UCS increased lipid peroxidation and ROS levels, while decreased NPSH levels and SOD activity, suggesting oxidative damage. EE for 28 days prevented all changes induced by the UCS protocol, and EE for 21 days prevented the alterations on NPSH levels, lipid peroxidation and ROS levels. Both EE for 21 or 28 days increased CAT activity. Discussion. Our findings reinforce the idea that EE exerts neuromodulatory effects in the zebrafish brain. EE promoted positive effects as it helped maintain the redox homeostasis, which may reduce the susceptibility to stress and its oxidative impact

Investigation on the Anticonvulsant Potential of Luteolin and Micronized Luteolin in Adult Zebrafish (Danio rerio)

Epilepsy affects around 50 million people worldwide, and an important number of patients (30%) fail to respond to any available antiepileptic drug. Previous studies have shown that luteolin presents a promising potential as an anticonvulsant. On the other hand, different studies showed that luteolin does not promote anticonvulsant effects. Therefore, there is a lack of consensus about the use of luteolin for seizure control. Luteolin low bioavailability could be a limiting factor to obtain better results. Attractively, micronization technology has been applied to improve flavonoids bioavailability. Thus, the present study aimed to investigate the effects of luteolin on its raw form and micronized luteolin in a PTZ-induced seizure model in adult zebrafish (Danio rerio). Our results demonstrate that luteolin and micronized luteolin did not block PTZ-induced seizures in adult zebrafish. Also, luteolin and micronized luteolin did not provoke behavioral changes. Finally, our results show that 24 h after seizure occurrence, no changes were detected for p70S6Kb, interleukin 1β, and caspase-3 transcript levels. Altogether, we failed to observe an anticonvulsant potential of luteolin in adult zebrafish, even in its micronized form. However, we recommend new studies to investigate luteolin benefits in epilepsy.Fil: Garbinato, Cristiane. No especifíca;Fil: Alves Lima Rezende, Cássia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Schneider, Sabrina Ester. No especifíca;Fil: Pedroso, Jefferson. No especifíca;Fil: dos Santos, Aline E.. Universidade Federal de Santa Catarina; BrasilFil: Petry, Fernanda. No especifíca;Fil: Aguiar, Gean Pablo S.. No especifíca;Fil: Girardi Müller, Liz. No especifíca;Fil: Lanza, Marcelo. Universidade Federal de Santa Catarina; BrasilFil: Piato, Angelo. Universidade Federal do Rio Grande do Sul; BrasilFil: Vladimir Oliveira, J.. Universidade Federal de Santa Catarina; BrasilFil: Siebel, Anna Maria. No especifíca

Environmental/Occupational Exposure to Pesticides of Pregnant Women Living in a Countryside Municipality / Exposição Ambiental/Ocupacional aos Agrotóxicos em Gestantes Residentes em um Município Rural

RESUMO Objetivo: Analisar se a exposição ambiental ou ocupacional aos agrotóxicos causa alterações em gestantes residentes em um município rural. Métodos: Compuseram a amostra 23 gestantes, que responderam a um questionário e doaram amostras biológicas para a realização dos testes de micronúcleos (MN) em linfócitos, em células do epitélio oral, e para a dosagem da atividade da enzima acetilcolinesterase eritrocitária. Resultados: Obteve-se uma média de 8 ± 2,92 MN/1000 células do epitélio oral analisadas em amostras de participantes da zona urbana, 6,82 ± 3,43 MN/1000 de participantes da zona rural, e 100% das lâminas continham células com dois MN, o que demonstra lesões ao DNA de maior intensidade. Encontrou-se uma frequência elevada de casos de abortos espontâneos (34,8%), superior à encontrada no Brasil. Conclusão: A exposição de gestantes residentes em um município rural aos agrotóxicos eleva a taxa de abortos espontâneos, bem como as chances de ocorrência de efeitos mutagênicos

Environmental/Occupational Exposure to Pesticides of Pregnant Women Living in a Countryside Municipality / Exposição Ambiental/Ocupacional aos Agrotóxicos em Gestantes Residentes em um Município Rural

RESUMOObjetivo: Analisar se a exposição ambiental ou ocupacional aos agrotóxicos causa alterações em gestantes residentes em um município rural. Métodos: Compuseram a amostra 23 gestantes, que responderam a um questionário e doaram amostras biológicas para a realização dos testes de micronúcleos (MN) em linfócitos, em células do epitélio oral, e para a dosagem da atividade da enzima acetilcolinesterase eritrocitária. Resultados: Obteve-se uma média de 8 ± 2,92 MN/1000 células do epitélio oral analisadas em amostras de participantes da zona urbana, 6,82 ± 3,43 MN/1000 de participantes da zona rural, e 100% das lâminas continham células com dois MN, o que demonstra lesões ao DNA de maior intensidade. Encontrou-se uma frequência elevada de casos de abortos espontâneos (34,8%), superior à encontrada no Brasil. Conclusão: A exposição de gestantes residentes em um município rural aos agrotóxicos eleva a taxa de abortos espontâneos, bem como as chances de ocorrência de efeitos mutagênicos

Contribution of S6K1/MAPK signaling pathways in the response to oxidative stress: activation of RSK and MSK by hydrogen peroxide

Trobareu correccions de l'article a: http://dx.doi.org/10.1371/annotation/0b485bd9-b1b2-4c60-ab22-3ac5d271dc59Cells respond to different kind of stress through the coordinated activation of signaling pathways such as MAPK or p53. To find which molecular mechanisms are involved, we need to understand their cell adaptation. The ribosomal protein, S6 kinase 1 (S6K1), is a common downstream target of signaling by hormonal or nutritional stress. Here, we investigated the initial contribution of S6K1/MAPK signaling pathways in the cell response to oxidative stress produced by hydrogen peroxide (H2O2). To analyze S6K1 activation, we used the commercial anti-phospho-Thr389-S6K1 antibody most frequently mentioned in the bibliography. We found that this antibody detected an 80-90 kDa protein that was rapidly phosphorylated in response to H2O2 in several human cells. Unexpectedly, this phosphorylation was insensitive to both mTOR and PI3K inhibitors, and knock-down experiments showed that this protein was not S6K1. RSK and MSK proteins were candidate targets of this phosphorylation. We demonstrated that H2O2 stimulated phosphorylation of RSK and MSK kinases at residues that are homologous to Thr389 in S6K1. This phosphorylation required the activity of either p38 or ERK MAP kinases. Kinase assays showed activation of RSK and MSK by H2O2. Experiments with mouse embryonic fibroblasts from p38 animals" knockout confirmed these observations. Altogether, these findings show that the S6K1 signaling pathway is not activated under these conditions, clarify previous observations probably misinterpreted by non-specific detection of proteins RSK and MSK by the anti-phospho-Thr389-S6K1 antibody, and demonstrate the specific activation of MAPK signaling pathways through ERK/p38/RSK/MSK by H2O2

Association of Mortality and Risk of Epilepsy With Type of Acute Symptomatic Seizure After Ischemic Stroke and an Updated Prognostic Model

IMPORTANCE: Acute symptomatic seizures occurring within 7 days after ischemic stroke may be associated with an increased mortality and risk of epilepsy. It is unknown whether the type of acute symptomatic seizure influences this risk. OBJECTIVE: To compare mortality and risk of epilepsy following different types of acute symptomatic seizures. DESIGN, SETTING, AND PARTICIPANTS: This cohort study analyzed data acquired from 2002 to 2019 from 9 tertiary referral centers. The derivation cohort included adults from 7 cohorts and 2 case-control studies with neuroimaging-confirmed ischemic stroke and without a history of seizures. Replication in 3 separate cohorts included adults with acute symptomatic status epilepticus after neuroimaging-confirmed ischemic stroke. The final data analysis was performed in July 2022. EXPOSURES: Type of acute symptomatic seizure. MAIN OUTCOMES AND MEASURES: All-cause mortality and epilepsy (at least 1 unprovoked seizure presenting >7 days after stroke). RESULTS: A total of 4552 adults were included in the derivation cohort (2547 male participants [56%]; 2005 female [44%]; median age, 73 years [IQR, 62-81]). Acute symptomatic seizures occurred in 226 individuals (5%), of whom 8 (0.2%) presented with status epilepticus. In patients with acute symptomatic status epilepticus, 10-year mortality was 79% compared with 30% in those with short acute symptomatic seizures and 11% in those without seizures. The 10-year risk of epilepsy in stroke survivors with acute symptomatic status epilepticus was 81%, compared with 40% in survivors with short acute symptomatic seizures and 13% in survivors without seizures. In a replication cohort of 39 individuals with acute symptomatic status epilepticus after ischemic stroke (24 female; median age, 78 years), the 10-year risk of mortality and epilepsy was 76% and 88%, respectively. We updated a previously described prognostic model (SeLECT 2.0) with the type of acute symptomatic seizures as a covariate. SeLECT 2.0 successfully captured cases at high risk of poststroke epilepsy. CONCLUSIONS AND RELEVANCE: In this study, individuals with stroke and acute symptomatic seizures presenting as status epilepticus had a higher mortality and risk of epilepsy compared with those with short acute symptomatic seizures or no seizures. The SeLECT 2.0 prognostic model adequately reflected the risk of epilepsy in high-risk cases and may inform decisions on the continuation of antiseizure medication treatment and the methods and frequency of follow-up

O papel do sistema purin?rgico e da via de sinaliza??o TOR em crises convulsivas e estresse oxidativo

Made available in DSpace on 2015-04-14T14:51:28Z (GMT). No. of bitstreams: 1 451454.pdf: 6697842 bytes, checksum: 890c954db41088b36538c3133a7c2606 (MD5) Previous issue date: 2013-09-27Epilepsy, characterized by the occurrence of spontaneous and recurrent seizures, is one of the main chronic neurological diseases, affecting around 1% of the world's population. Adenosine is an endogenous modulator of neuronal excitability and has anticonvulsant properties. Thus, the modulation of adenosinergic signalling pathway may presents important effects on epilepsy. In this study we characterize different aspects of the adenosinergic signaling in a model of seizures induced by pentylenetetrazole (PTZ) in zebrafish. In this study we also analyzed the effect of different modulators of adenosinergic signaling on controlling the development of seizures. Our results showed that the activation of type A1 adenosine receptors has an important role in controlling seizures in zebrafish. Furthermore, we observed that ecto-5?-nucleotidase and ADA enzymes, in addition to nucleoside transporters, are directly involved in controlling extracellular adenosine levels and, consequently, in controlling the development of seizures in this teleost. In addition, we clarified the occurrence of controversial data related to the mTOR signaling pathway in oxidative stress. Previous studies have suggested the activation of this pathway in oxidative stress based on the misinterpretation of the phosphorylation of RSK and MSK proteins through the antibody anti-phospho-Thr389-S6K, in addition to protein S6 phosphorylation, regulated by the MAPK signaling pathway in this case. Therefore, these findings might contribute for a better understanding about the signaling pathways involved in the mechanisms of seizure control and represents na alternative for the development of antiepileptic drugs, increasing the therapeutic options in epilepsia. Our results may also contribute to future studies on the characterization and modulation of TOR signaling pathway in zebrafish.A epilepsia, caracterizada pela ocorr?ncia de crises convulsivas espont?neas e recorrentes, ? umas das principais doen?as neurol?gicas cr?nicas, afetando em torno de 1% da popula??o mundial. A adenosina ? um modulador end?geno da excitabilidade neuronal e apresenta propriedades anticonvulsivantes. Sendo assim, a modula??o da via de sinaliza??o adenosin?rgica pode apresentar um efeito importante na epilepsia. Neste estudo, n?s caracterizamos diferentes aspectos da sinaliza??o adenosin?rgica em modelo de crise convulsiva induzida por pentilenotetrazol (PTZ) em peixe-zebra. Nossos resultados demonstram um aumento nas atividades da adenosina desaminase (ADA), respons?vel pela desamina??o de adenosina em inosina, logo ap?s uma crise convulsiva. Al?m disso, foi observado que os f?rmacos antiepil?pticos gabapentina, fenito?na e ?cido valpr?ico preveniram o efeito estimulat?rio promovido pelo PTZ sobre as atividades da adenosina desaminase. Neste estudo, tamb?m analisamos o efeito de diferentes moduladores da sinaliza??o adenosin?rgica no controle do desenvolvimento de convuls?es induzidas por PTZ. Nossos resultados demonstraram que a ativa??o de receptores de adenosina do tipo A1 tem importante participa??o no controle de crises convulsivas em peixe-zebra. Al?m disso, observamos que as enzimas ecto-5?-nucleotidase e ADA, al?m dos transportadores de nucleos?deos est?o diretamente envolvidos no controle dos n?veis extracelulares de adenosina e, consequentemente, no controle do desenvolvimento de crises convulsivas neste tele?steo. Al?m disso, esclarecemos a ocorr?ncia de dados controversos relacionados ? via de sinaliza??o mTOR em estresse oxidativo. Estudos sugeriram a ativa??o desta via em estresse oxidativo baseados na interpreta??o equivocada da fosforila??o das prote?nas RSK e MSK pelo anticorpo anti-fosfo-Thr389-S6K, al?m da fosforila??o da prote?na S6, regulada neste caso pela via de sinaliza??o MAPK. Este estudo pode contribuir para um maior entendimento das vias de sinaliza??o envolvidas nos mecanismos de controle de crises convulsivas e representar uma alternativa para o desenvolvimento de f?rmacos antiepil?pticos, aumentando as op??es terap?uticas em epilepsia. Nossos resultados tamb?m podem contribuir para futuros estudos referentes ? caracteriza??o e modula??o da via de sinaliza??o TOR em peixe-zebra

Efeito de crises convulsivas e f?rmacos antiepil?pticos em par?metros neuroqu?micos e moleculares em peixe zebra (Danio rerio)

Made available in DSpace on 2015-04-14T14:51:06Z (GMT). No. of bitstreams: 1 431137.pdf: 15580738 bytes, checksum: 8de463b0a32f5623e6e47a0d1d0edad2 (MD5) Previous issue date: 2011-03-10A epilepsia ? uma desordem neuronal caracterizada pela ocorr?ncia de convuls?es espont?neas e recorrentes. Essa patologia e seu tratamento interferem em diversos mecanismos neurol?gicos. O sistema purin?rgico ? uma importante rota de sinaliza??o celular que emprega nucleot?deos e nucleos?deos extracelulares como mol?culas sinalizadoras. O neurotransmissor ATP atua atrav?s de receptores do tipo P2Y, acoplados ? prote?na G e receptores P2X, que s?o ionotr?picos. A degrada??o do ATP extracelular e a conseq?ente produ??o de adenosina ? realizada por uma fam?lia de enzimas de superf?cie celular conhecidas como ectonucleotidases, que inclui as NTPDases (nucleos?deo trifosfato difosfoidrolases) e a ecto-5?-nucleotidase. A adenosina ? um neuromodulador que atua atrav?s da ativa??o de receptores metabotr?picos do tipo P1 (A1, A2A, A2B, A3). Esse nucleos?deo pode agir como um anticonvulsivante end?geno, principalmente via receptores A1. As NTPDases hidrolisam nucleot?deos tri- e difosfatados originando a adenosina, que ? hidrolisada pela adenosina deaminase (ADA). Assim, as NTPDases, ecto-5 -nucleotidase e ADA controlam os n?veis de nucleot?deos e nucleos?deos, modulando o sistema purin?rgico. No sistema colin?rgico, a acetilcolina (ACh) atua atrav?s de receptores muscar?nicos (metabotr?picos) e nicot?nicos (ionotr?picos). Sua a??o ? encerrada atrav?s de sua hidr?lise catalisada pela acetilcolinesterase (AChE). O peixe zebra ? um pequeno tele?steo de ?gua doce que vem sendo amplamente utilizado como modelo experimental em pesquisa. Estudos mostram que o peixe zebra pode ser uma ferramenta importante para o entendimento da epilepsia, bem como para o screening de f?rmacos antiepil?pticos. Considerando que as sinaliza??es purin?rgica e colin?rgica t?m importante participa??o no sistema nervoso e que essas vias de neurotransmiss?o est?o identificadas e caracterizadas em peixe zebra, o objetivo desse estudo foi avaliar nesse tele?steo o efeito de convuls?es induzidas por pentilenotetrazol (PTZ), bem como de f?rmacos antiepil?pticos na atividade das ectonucleotidases, ADA e AChE, enzimas essenciais na modula??o destas vias de sinaliza??o. Foram avaliados os efeitos in vitro da carbamazepina, fenito?na e gabapentina na atividade das ectonucleotidases e AChE. A carbamazepina diminuiu a hidr?lise de ATP e tamb?m de ACh. A fenito?na aumentou a hidr?lise de AMP e a gabapentina n?o provocou altera??es enzim?ticas. Foi analisado tamb?m o efeito de crises convulsivas induzidas por PTZ na atividade das ectonucleotidases e da ADA. Os resultados n?o mostraram altera??es nas ectonucleotidases e ADA nas fra??es extracelular e intracelular, respectivamente. No entanto, a atividade extracelular da ADA foi inibida em animais expostos ao PTZ. As an?lises mostraram que os f?rmacos antiepil?pticos podem influenciar a atividade das enzimas envolvidas na degrada??o extracelular de nucleot?deos, bem como na hidr?lise de ACh. Al?m disso, a diminui??o na degrada??o de adenosina observada em nosso modelo de estudo pode sugerir a participa??o da ADA na modula??o nos n?veis de adenosina durante as crises convulsivas em peixe zebr