Polyunsaturated fatty acids alter the formation of lipid droplets and eicosanoid production in Leishmania promastigotes

BACKGROUND The knowledge about eicosanoid metabolism and lipid droplet (LD) formation in the Leishmania is very limited and new approaches are needed to identify which bioactive molecules are produced of them. OBJECTIVES Herein, we compared LDs and eicosanoids biogenesis in distinct Leishmania species which are etiologic agents of different clinical forms of leishmaniasis. METHODS For this, promastigotes of Leishmania amazonensis, L. braziliensis and L. infantum were stimulated with polyunsaturated fatty acids (PUFA) and LD and eicosanoid production was evaluated. We also compared mutations in structural models of human-like cyclooxygenase-2 (GP63) and prostaglandin F synthase (PGFS) proteins, as well as the levels of these enzymes in parasite cell extracts. FINDINGS PUFAs modulate the LD formation in L. braziliensis and L. infantum. Leishmania spp with equivalent tissue tropism had same protein mutations in GP63 and PGFS. No differences in GP63 production were observed among Leishmania spp, however PGFS production increased during the parasite differentiation. Stimulation with arachidonic acid resulted in elevated production of hydroxyeicosatetraenoic acids compared to prostaglandins. MAIN CONCLUSIONS Our data suggest LD formation and eicosanoid production are distinctly modulated by PUFAS dependent of Leishmania species. In addition, eicosanoid-enzyme mutations are more similar between Leishmania species with same host tropism.

Leukotriene B4 Loaded in Microspheres Inhibits Osteoclast Differentiation and Activation

Abstract To investigate osteoclast formation in vivo and if leukotriene B4 (LTB4) loaded in microspheres (MS) could be used as a therapeutical strategy to promote a sustained delivery of the mediator and prevent osteoclast differentiation. Methods: In vivo, apical periodontitis was induced in mice to investigate osteoclast differentiation and signaling in absence of 5-lipoxygenase (5-LO). In vitro, LTB4-MS were prepared using an oil-in-water emulsion solvent extraction-evaporation process. Characterization and efficiency of LTB4 encapsulation were investigated. J774A.1 macrophages were cultured in the presence of monocyte colony-stimulating factor (M-CSF) and ligand for receptor activator of nuclear factor kappa B (RANKL) and then stimulated with LTB4-MS. Cytotoxicity, in vitro MS-LTB4 uptake, osteoclast formation and gene expression were measured. Results: We found that 5-LO negatively regulates osteoclastic formation in vivo during apical periodontitis development. In vitro, LTB4-MS were up-taken by macrophages and were not cytotoxic to the cells. LTB4-MS inhibited osteoclast formation and the synthesis of osteoclastogenic genes Acp5, Mmp9, Calcr and Ctsk. LTB4-MS inhibited differentiation of macrophages into an osteoclastic phenotype and cell activation under M-CSF and RANKL stimulus.

Resumo O objetivo deste trabalho foi Investigar a formação de osteoclastos in vivo e se o leucotrieno B4 (LTB4) incorporado em microesferas (MS) poderia ser usado como estratégia terapêutica para promover uma entrega sustentada do mediador e prevenir a diferenciação dos osteoclastos. Métodos: In vivo, a periodontite apical foi induzida em camundongos para investigar a diferenciação e sinalização de osteoclastos na ausência de 5-lipoxigenase (5-LO). In vitro, LTB4-MS foi preparado usando um processo de evaporação e extração de solvente de emulsão de óleo em água. A caracterização e a eficiência do encapsulamento do LTB4 foram investigadas. Macrófagos J774A.1 foram cultivados na presença de fator estimulador de colônia de monócitos (M-CSF) e ligante para o receptor ativador do fator nuclear kappa B (RANKL) e, então, estimulados com LTB4-MS. Citotoxicidade, captação in vitro de MS-LTB4, formação de osteoclastos e expressão gênica foram avaliadas. Resultados: A via 5-LO regula negativamente a formação de osteoclastos in vivo durante o desenvolvimento da periodontite apical. In vitro, LTB4-MS foram fagocitadas pelos macrófagos e não foram citotóxicos para as células. LTB4-MS inibiu a formação de osteoclastos e a síntese dos genes pró-osteoclastogênicos Acp5, Mmp9, Calcr e Ctsk. Conclusões: LTB4-MS inibiu a diferenciação de macrófagos em um fenótipo osteoclástico e a ativação celular sob estímulo de M-CSF e RANKL.

M1 and M2 macrophages phenotypes modulation after stimuli with materials used in endodontic treatment

Abstract The aim of this study was to evaluate the M1 and M2 macrophage modulation after stimuli with different materials used during endodontic treatment. In bone marrow-derived macrophage cell culture, from males C57BL/6 wild-type (WT) mice, gene expression analysis of markers to M1 and M2 macrophages was performed by qRT-PCR (Cxcl10, CxCL9, iNOS, Arg1, Chil3, Retnla and MRC1) and cytokine quantification by Luminex® (GM-CSF, IL-10, IL-6, IL-1β and TNF-α) after exposure to the five endodontic sealers: AH Plus, Sealapex Xpress, Endosequence BC Sealer, BioRoot RCS and a calcium hydroxide-based paste. For normal values, ANOVA test was used, followed by Tukey post-test. For non-normal values, the Kruskall-Wallis test was used. BioRootTM RCS and EndoSequence BC SealerTM stimulated the highest expression of markers for M1 macrophages, while calcium hydroxide-based paste stimulated the lowest expression of these gene markers. For M2 protein markers, BioRootTM RCS presented the highest stimulation while calcium hydroxide-based paste also presented the lowest stimulation. It was concluded that all the evaluated filling materials increased the genetic expression of pro- and anti-inflammatory markers: TNF-α and IL-10 respectively. The others proinflammatory mediators showed differences against the filling materials. However, this process did not induce the inflammatory response polarization, resulting in a hybrid macrophage.

Resumo O objetivo deste estudo foi avaliar a modulação dos macrófagos M1 e M2 após estímulos com diferentes materiais utilizados durante o tratamento endodôntico. Em cultura de células de macrófagos derivados da medula óssea de camundongos machos C57BL/6 wild-type (WT), após a exposição à cinco cimentos endodônticos: AH Plus, Sealapex Xpress, Endosequence BC Sealer, BioRoot RCS e pasta à base de hidróxido de cálcio foi realizada a análise da expressão gênica dos marcadores para macrófagos M1 e M2 por qRT-PCR (Cxcl10, CxCL9, iNOS, Arg1, Chil3, Retnla e MRC1) e quantificação de citocinas por Luminex® (GM -CSF, IL-10, IL-6, IL-1β e TNF-α). Para valores normais, foi utilizado o teste ANOVA, seguido do pós-teste de Tukey. Para valores não normais, foi utilizado o teste de Kruskall-Wallis. BioRootTM RCS e EndoSequence BC SealerTM estimularam maior expressão de marcadores para macrófagos M1, enquanto a pasta à base de hidróxido de cálcio estimulou expressão mais baixa desses marcadores gênicos. Para o marcador de proteínas para M2, BioRootTM RCS apresentou a maior estimulação, enquanto a pasta à base de hidróxido de cálcio também apresentou menor estimulação. Concluiu-se que os materiais obturadores avaliados aumentaram a expressão genética de marcadores pró- e anti-inflamatórios: TNF-α e IL-10 respectivamente. Os demais marcadores pró inflamatórios mostraram diferenças em relação aos materiais obturadores. No entanto, esse processo não induziu a polarização da resposta inflamatória, resultando em um macrófago híbrido.

Cytotoxicity and inflammatory mediators release by macrophages exposed to real seal xt and sealapex xpress

Abstract This study evaluated the cytotoxicity of Sealapex Xpress and Real Seal XT and their effect on macrophage activation. J774.1 macrophages were incubated with Sealapex Xpress and Seal Real XT (0.1, 1.0, and 10 mg/mL) for 24 and 48 h. Cell viability was assessed by the MTT assay and macrophage activation was measured by pro- and anti-inflammatory cytokine production using ELISA. Data were analyzed using one-way ANOVA and Tukey's post-test (a=0.05). Cell viability was not affected with 0.1 or 1.0 mg/mL of extracts of Sealapex Xpress and Real Seal XT at 24 and 48 h (p>0.05), but was significantly lower when cells were exposed to 10 mg/mL of both sealers (p<0.05). Sealapex Xpress inhibited the production of TNF-a, whereas Real Seal XT induced TNF-a secretion at 24 h (p<0.05). IL-6 production was induced by Real Seal XT, but not by Sealapex Xpress (p<0.05). Real Seal XT and Sealapex Xpress induced the secretion of anti-inflammatory IL-10. IL-4 was not detected in any group. In conclusion, both sealers had low toxicity but differentially activated macrophages. Macrophage activation by Sealapex Xpress was characterized by inhibition of TNF-a and induction of IL-10, whereas Real Seal XT induced IL-6 solely.

Resumo O objetivo deste estudo foi avaliar in vitro a citotoxicidade dos cimentos endodônticos Sealapex Xpress e Real Seal XT pelo ensaio de MTT e a ativação de macrófagos J774.1. Os cimentos endodônticos Sealapex Xpress e Real Seal XT foram pesados e os extratos foram obtidos a partir da diluição em meio de cultura DMEM por 48 horas (10mg/mL, 1mg/m, e 0,1 mg/mL). A viabilidade celular foi avaliada pelo ensaio MTT e a produção de citocinas (TNF-a, IL-6 e IL-10) foi investigada pelo ensaio imunoenzimático (ELISA) em células de linhagem (macrofagos J774.1). Os dados obtidos foram analisados utilizando-se análise de variância de uma via e pós-teste de Tukey (a=0,05). A viabilidade celular após 24 ou 48 horas não foi afetada nas concentrações de 0,1 ou 1 mg/mL dos dois cimentos estudados (p>0,05). Por outro lado, na concentração 10 mg/mL, a viabilidade celular foi significativamente mais baixa (p <0,05). Observou-se que o Sealapex Xpress inibiu a produção de TNF-a, enquanto o Real Seal XT induziu a secreção de TNF-a às 24 h (p<0,05). A produção de IL-6 foi induzida pelo Real Seal XT, mas não pelo Sealapex Xpress (p<0,05). A secreção da citocina anti-inflamatória IL-10 foi induzida tanto pelo Real Seal XT quanto pelo Sealapex Xpress. IL-4 não foi detectada em nenhum grupo. Em conclusão, os dois cimentos obturadores apresentaram baixa toxicidade, mas ativaram os macrófagos de modo distinto. A ativação pelo Sealapex Xpress foi caracterizada pela inibição do TNF-a e indução da IL-10, enquanto o Real Seal XT induziu somente IL-6.

Root canal contamination or exposure to lipopolysaccharide differentially modulate prostaglandin E 2 and leukotriene B 4 signaling in apical periodontitis

Abstract Purpose To evaluate the kinetics of apical periodontitis development in vivo , induced either by contamination of the root canals by microorganisms from the oral cavity or by inoculation of bacterial lipopolysaccharide (LPS) and the regulation of major enzymes and receptors involved in the arachidonic acid metabolism. Methodology Apical periodontitis was induced in C57BL6 mice (n=96), by root canal exposure to oral cavity (n=48 teeth) or inoculation of LPS (10 µL of a suspension of 0.1 µg/µL) from E. coli into the root canals (n= 48 teeth). Healthy teeth were used as control (n=48 teeth). After 7, 14, 21 and 28 days the animals were euthanized and tissues removed for histopathological and qRT-PCR analyses. Histological analysis data were analyzed using two-way ANOVA followed by Sidak's test, and qRT-PCR data using two-way ANOVA followed by Tukey's test (α=0.05). Results Contamination by microorganisms led to the development of apical periodontitis, characterized by the recruitment of inflammatory cells and bone tissue resorption, whereas inoculation of LPS induced inflammatory cells recruitment without bone resorption. Both stimuli induced mRNA expression for cyclooxygenase-2 and 5-lipoxygenase enzymes. Expression of prostaglandin E 2 and leukotriene B 4 cell surface receptors were more stimulated by LPS. Regarding nuclear peroxisome proliferator-activated receptors (PPAR), oral contamination induced the synthesis of mRNA for PPARδ, differently from inoculation of LPS, that induced PPARα and PPARγ expression. Conclusions Contamination of the root canals by microorganisms from oral cavity induced the development of apical periodontitis differently than by inoculation with LPS, characterized by less bone loss than the first model. Regardless of the model used, it was found a local increase in the synthesis of mRNA for the enzymes 5-lipoxygenase and cyclooxygenase-2 of the arachidonic acid metabolism, as well as in the surface and nuclear receptors for the lipid mediators prostaglandin E2 and leukotriene B4.

Successful and failed mini-implants: microbiological evaluation and quantification of bacterial endotoxin

Abstract Objectives Using two groups of mini-implants (successful and failed) the objectives of this in vivo study were: to evaluate the microbial contamination by the checkerboard DNA-DNA hybridization technique and to quantify the bacterial endotoxin by the limulus amebocyte lysate assay. Material and Methods The 15 successful and 10 failed mini-implants (1.6 mm diameter × 7.0 or 9.0 mm long), placed in the maxilla and/or mandible, were obtained from 15 patients undergoing orthodontic treatment. Data were analyzed statistically by the Wilcoxon rank-sum test using the SAS software (a=0.05). Results All 40 microbial species were detected in both groups of mini-implants, with different frequencies. No differences were observed between the groups with respect to microbial complexes (blue, purple, yellow, green, orange, red and other species) and endotoxin quantification (p>0.05). Conclusion Neither microbial contamination nor endotoxin quantification was determinant for the early loss of stability of the mini-implants.

Cytotoxicity and cytokine expression induced by silorane and methacrylate-based composite resins

ABSTRACT The successful use of composite resins in Dentistry depends on physicochemical properties, but also on the biological compatibility of resins, because of the close association between pulp and dentin. Objective The aim of this study was to evaluate cytotoxicity and cytokine production induced by light-cured or non-light-cured methacrylate-based and silorane composite resins in RAW 264.7 macrophages. Material and Methods Cells were stimulated with the extracts from light-cured or non-light-cured composite resins. After incubation for 24 h, cytotoxicity was assessed with the lactate dehydrogenase (LDH) and methyl thiazolyl tetrazolium (MTT) assays, and total protein was quantified using the Lowry method. TNF-α detection was examined with an enzyme-linked immunosorbent assay (ELISA) conducted with cell supernatants after cell stimulation for 6, 12, and 24 h. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey’s post hoc test (α=0.05). Results KaloreTM and FiltekTM Silorane were cytotoxic with or without light curing (p<0.05) after 24 h of incubation. KaloreTM stimulated the early production of TNF-α in comparison with control (p<0.05), whereas FiltekTM Silorane did not affect TNF-α levels after 6 and 12 h (p>0.05). However, after 24 h FiltekTM Silorane inhibited the production of TNF-α (p<0.05). Conclusions KaloreTM and FiltekTM Silorane were cytotoxic regardless of light curing. The extract obtained from KaloreTM after 15 days of incubation stimulated the production of TNF-α, unlike that obtained from FiltekTM Silorane.

Toxocara canis and the allergic process

The protective effect of infectious agents against allergic reactions has been thoroughly investigated. Current studies have demonstrated the ability of some helminths to modulate the immune response of infected hosts. The objective of the present study was to investigate the relationship between Toxocara canis infection and the development of an allergic response in mice immunised with ovalbumin (OVA). We determined the total and differential blood and bronchoalveolar lavage fluid cells using BALB/c mice as a model. To this end, the levels of interleukin (IL)-4, IL-5 and IL-10 and anti-OVA-IgE were measured using an ELISA. The inflammatory process in the lungs was observed using histology slides stained with haematoxylin and eosin. The results showed an increase in the total number of leukocytes and eosinophils in the blood of infected and immunised animals at 18 days after infection. We observed a slight lymphocytic inflammatory infiltrate in the portal space in all infected mice. Anti-OVA-IgE levels were detected in smaller proportions in the plasma of immunised and infected mice compared with mice that were only infected. Therefore, we concluded that T. canis potentiates inflammation in the lungs in response to OVA, although anti-OVA-IgE levels suggest a potential reduction of the inflammatory process through this mechanism.

Influência do biofármaco DNA-hsp65 na lesão pulmonar induzida por bleomicina / Influence of a DNA-hsp65 vaccine on bleomycin-induced lung injury

OBJETIVO: Avaliar a influência do biofármaco DNA-hsp65 em um modelo de distúrbio fibrosante pulmonar experimental. MÉTODOS: Foram estudados 120 camundongos machos C57BL/6, divididos em quatro grupos: grupo SS, animais tratados com salina (placebo) e injetados com salina intratraqueal (IT); grupo SB, tratados com salina (placebo) e injetados com bleomicina IT; grupo PB, tratados com plasmídeo, sem gene bacteriano, e injetados com bleomicina IT; e grupo BB, tratados com DNA-hsp65 e injetados com bleomicina IT. A bleomicina foi injetada 15 dias após a última imunização, e os animais sacrificados seis semanas após o uso da droga IT. O pulmão esquerdo retirado foi utilizado para análise morfológica, e o pulmão direito para dosagens de hidroxiprolina. RESULTADOS: A proporção de camundongos que apresentaram morte não-programada depois de 48 h da injeção IT foi maior no grupo SB em comparação ao grupo SS (57,7% vs. 11,1%). A área percentual média de interstício septal foi maior nos grupos SB e PB (53,1 ± 8,6% e 53,6 ± 9,3%, respectivamente) em comparação aos grupos SS e BB (32,9 ± 2,7% e 34,3 ± 6,1%, respectivamente). Os grupos SB, PB e BB mostraram aumentos nos valores médios da área de interstício septal corada por picrosirius em comparação ao grupo SS (SS: 2,0 ± 1,4%; SB: 8,2 ± 4,9%; PB: 7,2 ± 4,2%; e BB:6,6±4,1%).O conteúdo pulmonar de hidroxiprolina no grupo SS foi inferior ao dos demais grupos (SS: 104,9 ± 20,9 pg/pulmão; SB: 160,4 ±47,8 pg/pulmão; PB:170,0 ± 72,0 pg/pulmão; e BB: 162,5 ± 39,7 pg/pulmão). CONCLUSÕES: A imunização com o biofármaco DNA-hsp65 interferiu na deposição de matriz não-colágena em um modelo de lesão pulmonar induzida por bleomicina.

OBJECTIVE: To evaluate the effects of immunization with a DNA-hsp65 vaccine in an experimental model of pulmonary fibrosis. METHODS: A total of 120 male C57BL/6 mice were distributed into four groups: SS, injected with saline (placebo) and then receiving intratracheal (IT) instillation of saline; SB, injected with saline (placebo) and then receiving IT instillation of bleomycin; PB, treated with plasmid only, without bacterial genome, and then receiving IT instillation of bleomycin; and BB, treated with the vaccine and then receiving IT instillation of bleomycin. Bleomycin was instilled 15 days after the last immunization, and the animals were killed six weeks thereafter. The left and right lungs were removed, the former for morphological analysis and the latter for hydroxyproline measurements. RESULTS: The proportion of deaths within the first 48 h after the IT instillation (deaths attributed to the surgical procedure) was higher in the SB group than in the SS group (57.7% vs. 11.1%). The mean area of pulmonary interstitial septa was greater in the SB and PB groups (53.1 ± 8.6% and 53.6±9.3%, respectively) than in the SS and BB groups (32.9 ± 2.7% and 34.3 ± 6.1%, respectively). The mean area of interstitial septa stained by picrosirius was greater in the SB, PB and BB groups than in the SS group (8.2 ± 4.9%, 7.2 ± 4.2% and 6.6 ± 4.1%, respectively, vs. 2.0±1.4%). The total hydroxyproline content in the lung was significantly lower in the SS group (104.9 ± 20.9 pg/lung) than in the other groups (SB: 160.4 ± 47.8 pg/lung; PB: 170.0 ± 72.0 pg/lung; and BB: 162.5 ± 39.7 pg/lung). CONCLUSIONS: Immunization with the DNA-hsp65 vaccine reduced the deposition of noncollagen matrix in a model of bleomycin-induced lung lesion.

Effect of different methods of sterilization on the inactivation of bacterial endotoxin (LPS) in endodontic files

This study evaluated the presence of lipopolysaccharide (LPS) in endodontic files after in vitro contamination with E. coli LPS and sterilization in dry heat or wet heat, with or without previous immersion in a Ca(OH)2 suspension. LPS was quantified using the Kinetic QCL TM test and data were analyzed statistically by the t-test. LPS was quantified only in the contaminated group, not submitted to any immersion or sterilization procedure (0.262±0.1296 endotoxin units/mL) (p=0.0003). In conclusion, both wet heat and dry heat sterilization were effective in inactivating LPS without the need of previous immersion of the files in a Ca(OH)2 suspension.

Este estudo avaliou a presença de endotoxina (LPS) em limas endodônticas após contaminação in vitro com LPS de E. coli e esterilização em autoclave ou forno de Pasteur, com ou sem imersão prévia em suspensão de hidróxido de cálcio. A quantificação do LPS foi efetuada pelo teste Kinetic QCL TM, e os resultados submetidos à análise estatística (teste t). LPS foi quantificado apenas no grupo contaminado e não submetido a nenhum procedimento de imersão ou esterilização (0,262±0,1296 unidades de endotoxina/mL) (p=0,0003). Concluiu-se que a esterilização das limas em autoclave ou forno de Pasteur foi eficaz na inativação do LPS, não sendo necessária a sua imersão prévia em suspensão de hidróxido de cálcio.

É possível uma vacina gênica auxiliar no controle da tuberculose? / Could a DNA vaccine be useful in the control of tuberculosis?

Vacinas de DNA, ainda em fase de experimentação e testes clínicos, podem se tornar uma importante ferramenta de combate a doenças infecciosas para as quais, até hoje, não existe prevenção segura e eficaz, como a tuberculose. Nos últimos anos vários estudos têm sido dedicados ao desenvolvimento de vacinas de DNA que codificam proteínas de micobactérias, entre as quais destacam-se as que codificam o antígeno 85 (Ag 85) e a proteína de choque térmico de 65 kDa (hsp65). Estes dois antígenos foram os mais estudados apresentando resultados bastante satisfatórios em ensaios pré-clínicos e com grande volume de dados registrados na literatura. Além de proteger contra infecção experimental por Mycobacterium tuberculosis virulenta, a vacina DNA-hsp65 também apresenta atividade terapêutica, ou seja, é capaz de curar os animais previamente infectados, inclusive aqueles com bacilos resistentes a múltiplas drogas. Esta vacina, hoje em avaliação clínica no Brasil também para o tratamento de câncer, é capaz de induzir a produção de citocinas de padrão Th1 tal como IFN- interferon-gama, associadas ao controle da doença. Além disso, a vacina de DNA-hsp65 é capaz de estimular clones de células CD8 citotóxicos e CD4 que podem ser caracterizados como células de memória sendo responsáveis por conferir imunidade duradoura contra a infecção. Quando utilizada na terapia da infecção, a vacina de DNA-hsp65 faz com que haja uma mudança no padrão de resposta imune, induzindo a secreção de citocinas de padrão Th1 criando um ambiente favorável à erradicação do bacilo. Os resultados demonstram ainda que a via de administração e a formulação na qual a vacina é administrada exerce fundamental influência no padrão e duração da resposta imune desencadeada. O conjunto de resultados hoje disponíveis mostra que uma vacina de DNA contra a tuberculose contribuirá de maneira significativa no controle desta doença.

Strongyloides venezuelensis alkaline extract for the diagnosis of human strongyloidiasis by enzyme-linked immunosorbent assay

The present study was conducted to detected IgG antibodies using Strongyloides venezuelensis alkaline extract for the diagnosis of human strongyloidiasis by the enzyme-linked immunosorbent assay (ELISA). Sera from 90 subjects were analyzed (30 with strongyloidiasis, 30 with other parasites and 30 healthy individuals). Results were expressed in antibody titers, which were considered as positive when titer was > 80. Sensibility and specificity of the assay were 100 percent and 96.7 percent, respectively. It can be concluded that the heterologous alkaline extract could be employed in ELISA as a diagnostic aid in human strongyloidiasis, due to its advantages as easiness of obtaining, practicability in preparing, and high indexes of sensitivity and specificity