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

Relação cêntrica: avaliação dos traçados gráficos dos movimentos mandibulares antes e durante a utilização de prótese totais com pistas deslizantes de Nóbilo

This study aimed to observe the graphs of mandibular movements and the usual closing point of mandible, without external influence, before and during the use of Nóbilo's Complete Denture with Sliding Plates, through intraoral graphic registers. Twelve completed toothless patients, alleast for 10 years, and in the age between 50 and 80 years old, were selected. The Nóbilo's Complete Dentures with Sliding Plates were made based on face's Vertical Dimension, equable to facial golden proportions. The rates of bipupilar-Iabial comissure and nose bases-chin were equivalent to those which the patients showed before the installation of the disfunction, evidenced by analyses of photographs taken in the time when the patients had their natural teeth. Theses Dentures presented plane and smooth occlusal plataforms, which permitted mandible movement with more liberty. Proposed Dentures were evaluated during 120 days, adjusted weekly in the first month, and fortnightly until the end of 120 days. Allregisters of maxillomandibular relations of the patients were obtained through the plataforms of the intraoral registers according to Nóbilo's technic. Although, to make easy the graphics registers ofhorizontal movements, we idealise interchangeable metallic plates that were used during the times: O (zero), 15,45,75 and 120 days, in 10 patients. We obtained registers of 8 of these patients after 365 days of use of Nóbilo's Complete Denture with Sliding Plates. With 120 days of use of the proposed Complete Dentures, we observed that in 70% of patients, there was harmony in their trace of the gothic arch, and 90% of patients brought near of the usual closing point of Centric Relation. The vertex of the gothic arch was considered as the position of Centric Relation.CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorEste trabalho foi realizado com o objetivo de avaliar os traçados gráficos dos movimentos mandibulares e o ponto de fechamento habitual da mandíbula, sem indução externa, antes e durante o uso de Próteses Totais com Pistas Deslizantes de Nóbilo, através de registros gráficos intra-orais. Foram selecionados 12 pacientes, desdentados totais há pelo menos 10 anos, na faixa etária entre 50 e 80 anos. As Próteses Totais com Pistas Deslizantes de Nóbilo foram confeccionadas na Dimensão Vertical da face, correspondente às proporções faciais áuricas. As relações plano bipupilar comissura labial e base" do nariz-mento foram correspondentes às que o paciente apresentava antes que a disfunção se instalasse, constatadas por análises de fotografias, de uma época em que o paciente ainda apresentava seus dentes naturais. Estas Próteses possuíam plataformas oclusais planas e lisas, permitindo maior liberdade dos movimentos mandibulares. As Próteses propostas foram avaliadas durante 120 dias, ajustadas semanalmente no primeiro mês, e quinzenalmente até o final de 120 dias. Todos os registros das relações maxilo-mandibulares dos pacientes foram obtidos através das plataformas de registro intra-oral, segundo técnica de Nóbilo modificada. Todavia, para facilitar os registros gráficos dos movimentos horizontais, idealizamos discos metálicos intercambiáveis que foram usados nos prazos de O (zero),15, 45, 75 e 120 dias, em 10 dos pacientes. Conseguimos registros de 8 desses pacientes após 365 dias de uso das Próteses Totais com Pistas Deslizantes de Nóbilo. Aos 120 dias de uso das Próteses Totais propostas observamos que para 70% dos pacientes houve harmonização do traçado do arco gótico e que 90% dos pacientes aproximaram o ponto de fechamento habitual da posição de Relação Cêntrica. O ápice do arco gótico foi considerado como a posição de Relação Cêntrica

Expression of stem cell markers SALL4, LIN28A, and KLF4 in ameloblastoma

Abstract Background Ameloblastoma (AME) is a benign odontogenic tumour of epithelial origin characterised by slow but aggressive growth, infiltration, and recurrence; it is capable of reaching large dimensions and invading adjacent structures. Stem cell research has proven to be significant in the sphere of tumour biology through these cells’ possible involvement in the aetiopathogenesis of this tumour. Methods Immunohistochemistry was performed on AME, dentigerous cyst (DC), and dental follicle (DF) samples, and indirect immunofluorescence was performed on the AME-hTERT cell line to determine the expression of SALL4, LIN28A, and KLF4. Results Expression of proteins related to cellular pluripotency was higher in AME cells than in DC and DF cells. The analysis revealed that the proteins in question were mainly expressed in the parenchyma of AME tissue samples and were detected in the nuclei of AME-hTERT cells. Conclusions Stem cells may be related to the origin and progression of AME

Oxidative damage in human periodontal ligament fibroblast (hPLF) after methylmercury exposure

This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasil (CAPES)-Finance Code 001. Lygia S. Nogueira was supported by Programa Nacional de Pós-Graduação (PNPD/CAPES).Universidade Federal do Pará. Laboratório de Biologia Estrutural e Funcional. Belém, PA, Brazil / Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Citogenética e Cultura de Tecidos. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Citogenética e Cultura de Tecidos. Ananindeua, PA, Brasil.Universidade Federal do Pará. Laboratório de Cultura Celular. Belém, PA, Brazil.Universidade Federal do Pará. Laboratório de Cultura Celular. Belém, PA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Toxicologia. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Citogenética e Cultura de Tecidos. Ananindeua, PA, Brasil / Universidade Federal do Pará. Instituto de Ciências Exatas e Naturais. Belém, PA, Brazil.Universidade Federal do Pará. Laboratório de Biologia Estrutural e Funcional. Belém, PA, Brazil.Human exposure to mercury (Hg) is primary associated with its organic form, methylmercury (MeHg), through the ingestion of contaminated seafood. However, Hg contamination is also positively correlated with the number of dental restorations, total surface of amalgam, and organic mercury concentration in the saliva. Among the cells existing in the oral cavity, human periodontal ligament fibroblast (hPLF) cells are important cells responsible for the production of matrix and extracellular collagen, besides sustentation, renewal, repair, and tissue regeneration. In this way, the present study is aimed at investigating the potential oxidative effects caused by MeHg on hPLF. Firstly, we analyzed the cytotoxic effects of MeHg (general metabolism status, cell viability, and mercury accumulation) followed by the parameters related to oxidative stress (total antioxidant capacity, GSH levels, and DNA damage). Our results demonstrated that MeHg toxicity increased in accordance with the rise of MeHg concentration in the exposure solutions (1-7 μM) causing 100% of cell death at 7 μM MeHg exposure. The general metabolism status was firstly affected by 2 μM MeHg exposure (43:8±1:7%), while a significant decrease of cell viability has arisen significantly only at 3 μM MeHg exposure (68:7±1:4%). The ratio among these two analyses (named fold change) demonstrated viable hPLF with compromised cellular machinery along with the range of MeHg exposure. Subsequently, two distinct MeHg concentrations (0.3 and 3 μM) were chosen based on LC50 value (4.2 μM). hPLF exposed to these two MeHg concentrations showed an intracellular Hg accumulation as a linear-type saturation curve indicating that metal accumulated diffusively in the cells, typical for metal organic forms such as methyl. The levels of total GSH decreased 50% at exposure to 3 μM MeHg when compared to control. Finally, no alteration in the DNA integrity was observed at 0.3 μM MeHg exposure, but 3 μM MeHg caused significant damage. In conclusion, it was observed that MeHg exposure affected the general metabolism status of hPLF with no necessary decrease on the cell death. Additionally, although the oxidative imbalance in the hPLF was confirmed only at 3 μM MeHg through the increase of total GSH level and DNA damage, the lower concentration of MeHg used (0.3 μM) requires attention since the intracellular mercury accumulation may be toxic at chronic exposures

Detection and activity of MMP-2 and MMP-9 in Leishmania amazonensis and Leishmania braziliensis promastigotes

Institute Evandro Chagas (IEC), Department of Health Surveillance, Ministry of Health: Laboratory of Electron Microscopy and Laboratory of Superficial and Systemic Mycoses, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES)—finance code 001.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Microscopia Eletrônica. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Microscopia Eletrônica. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Microscopia Eletrônica. Ananindeua, PA, Brasil.Federal University of Para. School of Dentistry. Department of Oral Pathology. Belém, PA, Brazil.Federal University of Para. School of Dentistry. Department of Oral Pathology. Belém, PA, Brazil.Federal University of Para. School of Dentistry. Department of Oral Pathology. Belém, PA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Microscopia Eletrônica. Ananindeua, PA, Brasil.Metalloproteinases (MMPs) are remarkable zinc-dependent endopeptidases, critical for degrading components of the extracellular matrix, thus actively influencing cell migration. Their impact on intracellular parasites, such as the enigmatic protozoan Leishmania, elicits intriguing queries. This study explores into the untapped territory of MMP-2 and MMP-9 within Leishmania spp. promastigotes. Notably, we successfully detected and quantified these MMPs, while also evaluating their activity in two distinct Leishmania species—L. amazonensis (La) and L. braziliensis (Lb)—at various growth stages and isolated from distinct clinical tegumentar disease forms. The results unveiled the presence of MMP-2 and MMP-9 in both species, albeit with distinct localization patterns. Specifically, MMP-9 exhibited significantly higher gelatinolytic activity in La when compared to Lb. Moreover, our data cleverly illustrated the presence and release of MMP-2 and MMP-9 by La and Lb promastigotes, exposing their ability to invade and migrate within a collagen matrix. This pioneering study establishes a compelling correlation between MMP-2 and MMP-9 and their potential role in the dynamics of La and Lb infection. Suggesting their potential as prognostic markers for severe leishmaniasis and promising target molecules for therapeutic interventions, this research opens new avenues for combatting this debilitating parasitic disease

Detection and activity of MMP-2 and MMP-9 in Leishmania amazonensis and Leishmania braziliensis promastigotes

Abstract Metalloproteinases (MMPs) are remarkable zinc-dependent endopeptidases, critical for degrading components of the extracellular matrix, thus actively influencing cell migration. Their impact on intracellular parasites, such as the enigmatic protozoan Leishmania, elicits intriguing queries. This study explores into the untapped territory of MMP-2 and MMP-9 within Leishmania spp. promastigotes. Notably, we successfully detected and quantified these MMPs, while also evaluating their activity in two distinct Leishmania species—L. amazonensis (La) and L. braziliensis (Lb)—at various growth stages and isolated from distinct clinical tegumentar disease forms. The results unveiled the presence of MMP-2 and MMP-9 in both species, albeit with distinct localization patterns. Specifically, MMP-9 exhibited significantly higher gelatinolytic activity in La when compared to Lb. Moreover, our data cleverly illustrated the presence and release of MMP-2 and MMP-9 by La and Lb promastigotes, exposing their ability to invade and migrate within a collagen matrix. This pioneering study establishes a compelling correlation between MMP-2 and MMP-9 and their potential role in the dynamics of La and Lb infection. Suggesting their potential as prognostic markers for severe leishmaniasis and promising target molecules for therapeutic interventions, this research opens new avenues for combatting this debilitating parasitic disease

Non-lethal concentration of MeHg causes marked responses in the DNA repair, integrity, and replication pathways in the exposed human salivary gland cell line

Brazilian National Council for Scientific and Technological Development (CNPq); Brazilian Government/Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)-Finance Code 001 and Programa Nacional de Pós Doutorado/Capes (PNPD/CAPES). The APC was funded by Pró-Reitoria de Pesquisa e Pós-graduação da Universidade Federal do Pará (PROPESP-UFPA).Federal University of Pará. Laboratory of Functional and Structural Biology. Belém, PA, BrazilMinistério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Cultura Celular e Citogenética. Ananindeua, PA, BrasilUniversity of São Paulo. Medical School. University Hospital of the Ribeirão Preto. Regional Blood Center. Ribeirão Preto, SP, BrazilFederal University of Pará. School of Dentistry. Belém, PA, BrazilFederal University of Pará. Laboratory of Functional and Structural Biology. Belém, PA, BrazilFederal University of Pará. School of Dentistry. Belém, PA, BrazilMinistério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Cultura Celular e Citogenética. Ananindeua, PA, BrasilFederal University of Pará. Laboratory of Functional and Structural Biology. Belém, PA, BrazilIn Brazilian northern Amazon, communities are potentially exposed and vulnerable to methylmercury (MeHg) toxicity through the vast ingestion of fish. In vivo and in vitro studies demonstrated that the salivary glands as a susceptible organ to this potent environmental pollutant, reporting alterations on physiological, biochemical, and proteomic parameters. However, the alterations caused by MeHg on the gene expression of the exposed human salivary gland cells are still unknown. Therefore, the goal was to perform the transcriptome profile of the human salivary gland cell line after exposure to MeHg, using the microarray technique and posterior bioinformatics analysis. The cell exposure was performed using 2.5 µM MeHg. A previously published study demonstrated that this concentration belongs to a range of concentrations that caused biochemical and metabolic alterations in this linage. As a result, the MeHg exposure did not cause lethality in the human salivary gland cells line but was able to alter the expression of 155 genes. Downregulated genes (15) are entirety relating to the cell metabolism impairment, and according to KEGG analysis, they belong to the glycosphingolipid (GSL) biosynthesis pathway. On the other hand, most of the 140 upregulated genes were related to cell-cycle progression, DNA repair, and replication pathway, or cellular defenses through the GSH basal metabolism. These genomic changes revealed the effort to the cell to maintain physiological and genomic stability to avoid cell death, being in accordance with the nonlethality in the toxicity test. Last, the results support in-depth studies on nonlethal MeHg concentrations for biomarkers identification that interpret transcriptomics data in toxicological tests serving as an early alert of physiological changes in vitro biological models