Piceatannol Increases Antioxidant Defense and Reduces Cell Death in Human Periodontal Ligament Fibroblast under Oxidative Stress

Piceatannol is a resveratrol metabolite that is considered a potent antioxidant and cytoprotector because of its high capacity to chelate/sequester reactive oxygen species. In pathogenesis of periodontal diseases, the imbalance of reactive oxygen species is closely related to the disorder in the cells and may cause changes in cellular metabolism and mitochondrial activity, which is implicated in oxidative stress status or even in cell death. In this way, this study aimed to evaluate piceatannol as cytoprotector in culture of human periodontal ligament fibroblasts through in vitro analyses of cell viability and oxidative stress parameters after oxidative stress induced as an injury simulator. Fibroblasts were seeded and divided into the following study groups: control, vehicle, control piceatannol, H2O2 exposure, and H2O2 exposure combined with the maintenance in piceatannol ranging from 0.1 to 20 µM. The parameters analyzed following exposure were cell viability by trypan blue exclusion test, general metabolism status by the 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) method, mitochondrial activity through the ATP production, total antioxidant capacity, and reduced gluthatione. Piceatannol was shown to be cytoprotective due the maintenance of cell viability between 1 and 10 µM even in the presence of H2O2. In a concentration of 0.1 µM piceatannol decreased significantly cell viability but increased cellular metabolism and antioxidant capacity of the fibroblasts. On the other hand, the fibroblasts treated with piceatannol at 1 µM presented low metabolism and antioxidant capacity. However, piceatannol did not protect cells from mitochondrial damage as measured by ATP production. In summary, piceatannol is a potent antioxidant in low concentrations with cytoprotective capacity, but it does not prevent all damage caused by hydrogen peroxide

Alterações de expressão gênica na linhagem de glioblastoma humano U87 após exposição ao MeHg e HgCl2

The organic and inorganic forms of mercury have been pointed as important contaminants in several world regions due to its toxicological characteristics. Various studies have reported that the intoxication by methylmercury (MeHg) and mercury chloride (HgCl2) can lead to central nervous system impairment. It is generally agreed that glial cells are important for the mechanisms responsible for cellular protection against the damages caused by the mercury. However, little is known about the influence of the mercury in the cells genome. Hence, in the present study we did a complete mapping of the humam glial cells genetic network after mercury exposition with the aim to indentify the possible genetic alterations that occurred via the organic and inorganic forms of mercury. Our results demonstrated that U87 lineage cells are more sensitive to MeHg exposition when compared with HgCl2 exposition. Using an analysis of the concentration curves the LC50 was obtained from 28.8μM and 10,68μM after 4h and 24h exposition to MeHg and a LC50 of 92.25μM and 62.75μM after the same time periods exposition to HgCl2. Regarding the genic pool, our results have shown that both metal forms led to alterations in the genic dosage where the MeHg exposition was highly influenced by the concentration and time, whereas the HgCl2 exposition seemed have been strongly influenced by the exposition time. In total there were 205 indentified genes with a lower genic dosage and 188 genes with elevated expression, (Fold change > 5) after 4h exposition and 5μM of MeHg, and 204 down-regulated genes; and 180 up-regulated genes after HgCl2 exposition in the same concentration. The analysis after 24h exposition showed 90 down-regulated genes and 3 up-regulated genes after 1μM of MeHg; 116 genes were down-regulated and 66 genes were up-regulated after a 10μM exposition of MeHg. As for the HgCl2, there were 98 down-regulated genes and 73 up-regulated genes for the groups exposed to 5μM of HgCl2; 326 down-regulated genes and 66 up-regulated genes for the groups exposed to 62,75μM of HgCl2. Our dataset suggests that both mercurial forms are able to alter the cell genetic expression profile thus interfering in important signaling paths prone to gives rise to biochemical impairments and glial cells phenotypes.CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorCNPq - Conselho Nacional de Desenvolvimento Científico e TecnológicoAs formas orgânicas e inorgânicas de mercúrio vem sendo apontadas como importantes contaminantes em várias regiões do mundo devido suas características toxicológicas. Diversos estudos já relataram que a intoxicação por metilmercúrio (MeHg) e cloreto de mercúrio (HgCl2) podem ocasionar danos ao SNC. Acredita-se que as células da glia são reconhecidamente importantes para os mecanismos de proteção celular frente aos danos ocasionados pelo mercúrio. No entanto, pouco se sabe a respeito da influência deste metal no genoma dessas células. Desta forma, neste trabalho nós realizamos um mapeamento completo da rede gênica de células da glia humana, da linhagem U87 após exposição mercurial, com o intuito de identificar as possíveis alterações genéticas ocasionadas pelas formas orgânicas e inorgânicas do mercúrio. Nossos resultados demonstraram que as células U87 são mais sensíveis a exposição ao MeHg quando comparado com a exposição ao HgCl2. Após análise de curvas de concentração, foi identificado uma LC50 de 28.8μM e 10,68μM após 4h e 24h de exposição a MeHg e uma LC50 de 92.25μM e 62.75μM após o mesmo tempo de exposição a HgCl2. Em relação ao conteúdo gênico, nossos resultados demonstraram que ambos os metais ocasionaram alteração na dosagem gênica, sendo a exposição ao MeHg altamente influenciada pela concentração e tempo de exposição, enquanto a exposição a HgCl2 parece ser fortemente influenciada pelo tempo de exposição. No total, foram identificados 205 genes com diminuição na dosagem gênica e 188 genes com expressão aumentada (Fold change > 5) após 4h de exposição a 5μM de MeHg e 204 genes down-regulados e 180 up-regulados após exposição na mesma concentração de HgCl2. As análises após 24h de exposição identificaram alteração em 90 genes down-regulados e 3 genes up-regulados após exposição a 1μM de MeHg, 116 genes down-regulados e 66 genes up-regulados após exposição a 10μM de MeHg. Já em relação ao HgCl2, foram identificados 98 genes down-regulados e 73 genes up-regulados nos grupos expostos a 5μM de HgCl2, 326 genes down-regulados e 66 genes up-regulados nos grupos expostos a 62,75μM de HgCl2. Nossos dados sugerem que ambas as formas mercuriais são capazes de alterar o perfil gênico das células da linhagem U87, interferindo assim em importantes vias de sinalização capazes de ocasionar alterações bioquímicas e fenotípicas nas células gliais

Análise do efeito tóxico e alterações transcriptomicas de células neuronais e gliais após exposição ao fluoreto

Despite being widely used in dentistry for dental carie control, in high amounts fluoride may be associated with side effects of which the best known is dental fluorosis. In addition, studies suggest that even at low concentrations fluoride may exerts toxicity leading to damage on CNS. Functional toxicogenomics analysis of gene profile after exposure to contaminants has been used as a tool for the identification of biomarkers of exposure, as well as for the identification of signaling pathways that may be used for treatment and / or prevention of damage caused by the toxicity of certain compounds. As the molecular mechanism of fluoride toxicity still unknow, analysis of F chronic exposure on gene expression profile of CNS cells are necessary. Here we aimed to show the effect of fluoride exposure of plasma concentration founded on population that used to be exposed to fluoridated drink water, on the main CNS cells. In this way, we have used human cell lineage IMR-32 (neurons) and U87 (glial cells) to analyze parameter of viability, morphology and cell metabolism, ATP-synthesis, oxidative stress, DNA damage and global gene expression profile after 10 days exposure. Our results have shown that fluoride does not induce changes in IMR-32 cells. On the other hand, it induces cell death by necrosis, increased metabolism, decrease in ATP and GSH / GSSG in U87 cells and DNA fragmentation. The U87 gene expression profile is differentially altered after fluoride exposure, decreasing 1735 genes and an increasing expression of 1047 genes after exposure to 0.095μg / mL and decreasing of 1863 gene expression and increasing of 1023 expression after exposure to 0.22μg / mL. We also highlighted the major molecular pathways altered after exposure, such as the signaling pathway TNF-alpha via NFK-B and mitochondrial process. We also showed genes with significant importance biology (hub genes) such as the genes PTGES3, EP300, CYP1B1, RPS27A. Our results suggests that glial cell are affected by fluorides exposure and mitochondria has a major role on the mechanism of fluoride toxicity.CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorApesar de ser amplamente utilizado na Odontologia para o controle da cárie dentária, quando ingerido em grandes quantidades o fluoreto pode causar efeitos colaterais, dos quais o mais conhecido é a fluorose dentária. Além disso, estudos também sugerem que mesmo em baixas concentrações o flúor pode originar quadros de toxicidade, levando a prejuízos no SNC. A toxicogenômica funcional, que fornece análises de perfis gênicos após exposição a contaminantes tem sido utilizada como ferramenta para a identificação de biomarcadores da intoxicação, bem como para a identificação de vias de sinalização que possam ser utilizadas para o tratamento e/ou prevenção dos danos ocasionados pela toxicidade de determinados compostos. Sabendo-se que os mecanismos moleculares da toxcidade do flúor no SNC ainda permanecem desconhecidos, a análise da exposição prolongada a fluoretos sobre o perfil gênico de poupulações de células do SNC se faz necessário. Nessa tese nós buscamos avaliar os efeitos da exposição a concentrações comumente encontradas no plasma sanguineo da população que ingere agua fluoretada nas principais células do SNC. Para isso, nós utilizados células humanas da linhagem IMR-32 (neurônio) e U87 (glia) e avaliamos parametros de viabilidade e morfologia celular, metabolismo, produção de ATP, estresse oxidativo, fragmentação do DNA e perfil global de expressão gênica após 10 dias de exposição. Nossos resultados demonstraram que o fluoreto não induz alterações fisologicas nas células IMR-32. Por outro lado, induz morte celular por necrose, aumento do metabolismo, diminuição no ATP e GSH/GSSG e fragementação do DNA nas células U87. O perfil de expressão gênica das células U87 foi diferencialmente alterado após exposição ao fluoreto, com diminuição de 1735 genes e aumento na expressão de 1047 genes após exposição a 0.095μg/mL e a diminuição da expressão de 1863 genes e aumento da expressão de 1023 após exposição a 0.22μg/mL. Nossos dados tambem sugerem uma significativa alteração na via TNF-alfa via NFK-B e em processos mitocondriais. Também evidenciamos genes com significativa importância biologia (genes hub) como os genes PTGES3, EP300, CYP1B1, RPS27A. Dessa forma, nossos dados sugerem que as células da glia são afetadas pela exposição ao flúor, sugerindo que a mitocôndria desempenha um importante papel no mecanismo toxicológico do flúor

Astrocyte-like cells transcriptome changes after exposure to a low and non-cytotoxic MeHg concentration

This study was financed in part by the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior-Brasil (CAPES)-Finance Code 001. Programa Nacional de PosGraduacao (PNPD/CAPES).Federal University of Pará. Institute of Biological Science. Laboratory of Functional and Structural Biology. Belém, PA, Brazil / Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Cultura de Tecidos e Citogenética. Ananindeua, PA, Brasil.Federal University of Pará. Institute of Biological Science. Laboratory of Functional and Structural Biology. Belém, PA, BrazilNational Council for Scientific and Technological Development. National Institute of Science and Technology in Stem Cell and Cell Therapy. Research Support Foundation of the State of São Paulo. Ribeirão Preto, SP, BrazilMinistério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Cultura de Tecidos e Citogenética. Ananindeua, PA, BrasilFederal University of Pará. Institute of Biological Science. Laboratory of Functional and Structural Biology. Belém, PA, BrazilThe central nervous system is the main target of MeHg toxicity and glial cells are the first line of defense; however, their true role remains unclear. This study aimed to identify the global map of human glial-like (U87) cells transcriptome after exposure to a non-toxic and non-lethal MeHg concentration and to investigate the related molecular changes. U87 cells were exposed upon 0.1, 0.5, and 1 mu M MeHg for 4 and 24 h. Although no changes were observed in the percentage of viable cells, the metabolic viability was significantly decreased after exposure to 1 mu M MeHg for 24 h; thus, the non-toxic concentration of 0.1 mu M MeHg was chosen to perform microarray analysis. Significant changes in U87 cells transcriptome were observed only after 24 h. The expression of 392 genes was down regulated while 431 genes were up-regulated. Gene ontology showed alterations in biological processes (75%), cellular components (21%), and molecular functions (4%). The main pathways showed by KEGG and Reactome were cell cycle regulation and Rho GTPase signaling. The complex mechanism of U87 cells response against MeHg exposure indicates that even a low and non-toxic concentration is able to alter the gene expression profile

Behavioral and neurochemical changes in the zebrafish leopard strain

<p>Abstract</p> <p>The zebrafish leopard phenotype (leo) displays abnormal pigmentation and increased anxiety-like behavior. The neurochemical changes associated with this anxious phenotype are not known. Here, we demonstrate that leo show increased anxiety-like behavior in the light/dark box and in the novel tank test. This anxious phenotype is rescued by acute treatment with a dose of a serotonin reuptake inhibitor, fluoxetine, that is inactive in wild-type animals. Moreover, leoshow decreased tissue levels of serotonin, increased serotonin turnover, and slightly increased monoamine oxidase activity. These results suggest that the anxious phenotype observed in leo zebrafish is caused by a decrease in serotonin uptake.</p

Human cultured IMR-32 neuronal-like and U87 glial-like cells have different patterns of toxicity under fluoride exposure

This study was supported by the Conselho Nacional de Desenvolvimento Científico e Tecnológico – Brasil (CNPq) (grant no. 435093/ 2018-5) and the Coordination of Personal Improvement of Higher Education – (CAPES) Brasil (Finance Code 001).Federal University of Para. Institute of Biological Sciences. Laboratory of Functional and Structural Biology. Belém, PA, Brazil / Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Cultura Celular e Citogenética. Ananindeua, PA, Brasil.Federal University of Para. Institute of Biological Sciences. Laboratory of Functional and Structural Biology. Belém, PA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Cultura Celular e Citogenética. Ananindeua, PA, Brasil.University of São Paulo. Department of Biological Sciences. Bauru Dental School. Bauru, SP, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Cultura Celular e Citogenética. Ananindeua, PA, Brasil.Federal University of Para. Institute of Biological Sciences. Laboratory of Functional and Structural Biology. Belém, PA, Brazil.Background Fluoride (F) is a naturally exists in nature but several studies have indicated it as an environmental toxicant to all leaving beings. Human F exposure has increased over the years since this ion has been used by industry on foods, beverages, toothpastes and on water supply. Although F is safe at optimal concentrations in water supply, human exposure to high levels could trigger neurofunctional deficits. Materials and methods In this study, human glial-like (U87) and neuronal-like (IMR-32) cells lineages were used to access F toxicity and CNS cell sensibility on both cell facing the same protocol. Cells were exposed to F over 3, 5 and 10 days on two different F concentrations. Fluoride exposed cells were evaluated by standard toxicity assays to cell viability, apoptosis, necrosis and general cell metabolism. Oxidative stress parameters were evaluated by ATP and ROS levels, lipid peroxidation, GSH/GSSG ratio and comet assay. Results No changes were observed in IMR-32 at any given time while after 10 days of exposure to 0.22μg/mL, U87 glial-like cells showed signs of toxicity such as decreased cell viability by necrosis while general cell metabolism was increased. Oxidative stress parameters were next evaluated only on U87 glial-like cells after 10 days of exposure. F induced a decrease on ATP levels while no changes were observed on reactive oxygen species and lipid peroxidation. GSH/GSSG ratio was decreased followed by DNA damage both on 0.22μg/mL F. Conclusions Our results suggest an important differential behavior of the distinct types of cells exposed to the different fluoride concentrations, pointing that the U87 glial-like cells as more susceptible to damage triggered by this ion. © 2021 Puty et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Mebendazole induces apoptosis via C-MYC inactivation in malignant ascites cell line (AGP01)

Federal University of Pará. Biological Science Institute. Laboratory of Experimental Neuropathology. Belém, PA, Brazil.Federal University of Ceará. Drug Research and Development Center. Laboratory of Pharmacogenetics. Fortaleza, CE, Brazil.Federal University of Pará. Biological Science Institute. Laboratory of Human Cytogenetics. Belém, PA, Brazil.Federal University of Ceará. Drug Research and Development Center. Laboratory of Pharmacogenetics. Fortaleza, CE, Brazil.Federal University of Pará. Laboratory of Structural and Functional Biology Science. Belém, PA, Brazil / Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Cultura Celular e Citogenética. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Cultura Celular e Citogenética. Ananindeua, PA, Brasil.Federal University of Pará. Biological Science Institute. Laboratory of Human Cytogenetics. Belém, PA, Brazil.Federal University of Ceará. Drug Research and Development Center. Laboratory of Pharmacogenetics. Fortaleza, CE, Brazil.The objective of study was to examine the role of MBZ on malignant ascites cells and the involvement of C-MYC. Comet assay was used to assess the genotoxic effects of MBZ in AGP01 cells and human lymphocytes; differential staining by ethidium bromide and acridine orange, caspase 3/7 and flow cytometry assay was done to access the mechanisms of apoptosis and cell cycle analysis of MBZ in AGP01 cells. C-MYC amplification, C-MYC mRNA and C-MYC protein expression were evaluated by FISH, RT-qPCR and Western blotting, respectively. In addition, cytotoxicity of MBZ was evaluated in AGP01 and AGP01 shRNA MYC by MTT. MBZ significantly increased the damage index and no produced in human lymphocytes. MBZ caused remarkable cell cycle arrest in G0/G1 and G2/M phases at 0.5μM and 1.0 μM, respectively and induced significantly apoptosis in higher concentrations. Additionally, MBZ (0.5 μM and 1.0 μM) increased caspase 3 and 7 activities. MBZ decreased signals, C-MYC mRNA and C-MYC protein expression in AGP01 cells. MBZ induced lower cell viability in AGP01 cells compared AGP01 shRNA MYC in the same concentration. Therefore, our results show the evidence of C-MYC gene as one of the pathways by which MBZ induces cell death in gastric cancer cells

Association of cerebral malaria and TNF-alpha levels: a systematic review

This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Código de Financiamento 001.Federal University of Pará. Institute of Biological Sciences. Laboratory of Functional and Structural Biology. Belém, PA, Brazil.Federal University of Pará. Institute of Health Sciences. Postgraduate Program in Pharmaceutical Sciences. Belém, PA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Federal University of Pará. Institute of Biological Sciences. Laboratory of Functional and Structural Biology. Belém, PA, Brazil.Federal University of Pará. Institute of Biological Sciences. Laboratory of Functional and Structural Biology. Belém, PA, Brazil.University of Alberta. Faculty of Medicine and Dentistry. School of Dentistry. Edmonton, Canada.Federal University of Rio de Janeiro. School of Dentistry. Department of Pediatric Dentistry and Orthodontics. Rio de Janeiro, RJ, Brazil.Federal University of Pará. Institute of Biological Sciences. Laboratory of Functional and Structural Biology. Belém, PA, Brazil.Background: Cerebral malaria is the most severe form of infection with Plasmodium falciparum characterized by a highly inflammatory response. This systematic review aimed to investigate the association between TNF-α levels and cerebral malaria. Methods: This review followed the Preferred Reporting of Systematic Review and Meta-analyses (PRISMA) guidelines. The search was performed at PubMed, LILACS, Scopus, Web of Science, The Cochrane Library, OpenGrey and Google Scholar. We have included studies of P. falciparum-infected humans with or without cerebral malaria and TNF-α dosage level. All studies were evaluated using a risk of bias tool and the GRADE approach. Results: Our results have identified 2338 studies, and 8 articles were eligible according to this systematic review inclusion criteria. Among the eight articles, five have evaluated TNF- α plasma dosage, while two have evaluated at the blood and one at the brain (post-Morten). Among them, only five studies showed higher TNF-α levels in the cerebral malaria group compared to the severe malaria group. Methodological problems were identified regarding sample size, randomization and blindness, but no risk of bias was detected. Conclusion: Although the results suggested that that TNF-α level is associated with cerebral malaria, the evidence is inconsistent and imprecise. More observational studies evaluating the average TNF-alpha are needed

Unraveling molecular characteristic of fluoride neurotoxicity on U87 glial-like cells: insights from transcriptomic and proteomic approach

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) from Brazilian Ministry of Science, Technology, Innovation and Communications.Federal University of Pará. Institute of Biological Sciences. Laboratory of Functional and Structural Biology. Belém, PA, Brazil / Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Cultura Celular e Citogenética. Ananindeua, PA, Brasil.Federal University of Pará. Institute of Biological Sciences. Laboratory of Functional and Structural Biology. Belém, PA, Brazil.Federal University of Pará. Institute of Biological Sciences. Laboratory of Functional and Structural Biology. Belém, PA, Brazil.National Council for Scientific and Technological Development. National Institute of Science and Technology in Stem Cell and Cell Therapy. Center for Cell-Based Therapy. Ribeirão Preto, SP, Brazil / Fundação de Amparo á Pesquisa do Estado de São Paulo. Centro de Pesquisa, Inovação e Desenvolvimento. Ribeirão Preto, SP, Brazil.University of São Paulo. Bauru School of Dentistry. Department of Biological Sciences. Bauru, SP, Brazil.University of São Paulo. Bauru School of Dentistry. Department of Biological Sciences. Bauru, SP, Brazil.Federal University of Pará. Institute of Biological Sciences. Laboratory of Neurophysiology Eduardo Oswaldo Cruz. Belém, PA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Cultura Celular e Citogenética. Ananindeua, PA, Brasil.Federal University of Pará. Institute of Biological Sciences. Laboratory of Functional and Structural Biology. Belém, PA, Brazil.The potential of fluoride (F) as a neurotoxicant in humans is still controversial in the literature. However, recent studies have raised the debate by showing different mechanism of F-induced neurotoxicity, as oxidative stress, energy metabolism and inflammation in the central nervous system (CNS). In the present study, we investigated the mechanistic action of two F concentration (0.095 and 0.22 µg/ml) on gene and protein profile network using a human glial cell in vitro model over 10 days of exposure. A total of 823 genes and 2,084 genes were modulated after exposure to 0.095 and 0.22 µg/ml F, respectively. Among them, 168 were found to be modulated by both concentrations. The number of changes in protein expression induced by F were 20 and 10, respectively. Gene ontology annotations showed that the main terms were related to cellular metabolism, protein modification and cell death regulation pathways, such as the MAP kinase (MAPK) cascade, in a concentration independent manner. Proteomics confirmed the changes in energy metabolism and also provided evidence of F-induced changes in cytoskeleton components of glial cells. Our results not only reveal that F has the potential to modulate gene and protein profiles in human U87 glial-like cells overexposed to F, but also identify a possible role of this ion in cytoskeleton disorganization