Aggregatibacter actinomycetemcomitans Outer Membrane Proteins 29 and 29 Paralogue Induce Evasion of Immune Response.

Aggregatibacter actinomycetemcomitans (Aa) is abundant within the microbial dysbiotic community of some patients with periodontitis. Aa outer membrane protein 29 (OMP29), a member of the OMPA family, mediates the invasion of Aa to gingival epithelial cells (GECs). This study evaluated the effect of OMP29 and its paralogue OMP29par on the response of GECs to Aa. The omp29 or/and omp29 par deletion mutants AaΔ29, AaΔ29P, and AaΔ29Δ29P were constructed, and recombinant Aa OMP29His was obtained. Microarray analysis and the evaluation of cxcl-8 gene expression were performed to examine the response of GECs line OBA-09 to Aa and its mutants. The expression of cxcl-8 and its product CXCL-8 was examined in LPS-stimulated OBA-09 cells with Aa OMP29His. Proteomics analysis showed that the deletion of omp29 led to overexpression of both OMP29par and another membrane protein OMP39, the expression of which was further increased in AaΔ29Δ29P. OBA-09 cells challenged with AaΔ29Δ29P exhibited a higher expression of cxcl-8 in comparison to wildtype Aa strain AaD7S or single-deletion mutants AaΔ29 or AaΔ29P. LPS-stimulated OBA-09 cells challenged with Aa OMP29His showed reduced expressions of cxcl-8 and its product CXCL-8. OBA-09 cells challenged with AaΔ29Δ29P in comparison to Aa strain AaD7S resulted in higher expressions of genes involved in apoptosis and inflammatory response such as bcl2, birc3, casp3, c3, ep300, fas, fosb, grb2, il-1α, il-1ß, il-6, cxcl-8, nr3c1, prkcq, socs3, and tnfrsf1ß and reduced expressions of cd74, crp, faslg, tlr1, and vcam1. The results suggested a novel strategy of Aa, mediated by OMP29 and OMP29par, to evade host immune response by inhibiting CXCL-8 expression and modulating the genes involved in apoptosis and inflammatory response in GECs. Pending further confirmation, the strategy might interfere with the recruitment of neutrophils and dampen the host inflammatory response, leading to a more permissive subgingival niche for bacterial growth.

Effects of Monolaurin on Oral Microbe-Host Transcriptome and Metabolome.

The aim of this in vitro study was to evaluate the effects of monolaurin against Aggregatibacter actinomycetemcomitans (Aa) and determine their effects on the host transcriptome and metabolome, using an oral cell/bacteria co-culture dual-chamber model to mimic the human periodontium. For this, the Aa, was applied to cross the monolayer of epithelial keratinocytes (OBA-9) to reach the fibroblasts layer (HGF-1) in the basal chamber. The Monolaurin treatments (25 or 50 µM) were added immediately after the inoculation of the dual-chamber with Aa. After 24 h, the transcriptional factors and metabolites produced were quantified in the remaining cell layers (insert and basal chamber) and in supernatant released from the cells. The genes IL-1α, IL-6, IL-18, and TNF analyzed in HGF-1 concentrations showed a decreased expression when treated with both concentration of Monolaurin. In keratinocytes, the genes IL-6, IL-18, and TNF presented a higher expression and the expression of IL-1α decreased when treated with the two cited concentrations. The production of glycerol and pyruvic acid increased, and the 2-deoxytetronic acid NIST, 4-aminobutyric acid, pinitol and glyceric acid, presented lower concentrations because of the treatment with 25 and/or 50 µM of Monolaurin. Use of monolaurin modulated the immune response and metabolite production when administered for 24 h in a dual-chamber model inoculated with A. actinomycetemcomitans. In summary, this study indicates that monolaurin had antimicrobial activity and modulated the host immune response and metabolite production when administered for 24 h in a dual-chamber model inoculated with A. actinomycetemcomitans.

Physical Exercise Improves Glycemic and Inflammatory Profile and Attenuates Progression of Periodontitis in Diabetic Rats (HFD/STZ).

The authors aimed to evaluate the effects of physical exercise on the metabolism and progression of periodontal disease (PD), induced by ligature in diabetic rats induced by high fat diet and streptozotocin (HFD/STZ). Diabetes Mellitus (DM) was induced by four weeks of a hyperlipidic diet associated with a single low-dose of streptozotocin (35 mg/kg/animal). The exercise groups swam for 60 min/day for eight weeks (five times/week). In the last two weeks of exercise, a ligature was placed around the right and left mandibular first molars. The authors determined alveolar bone loss by morphometry. Blood biochemical profile and serum levels of IL-10 and TNF-α were evaluated by colorimetric and enzyme-linked immunosorbent assays (ELISA), respectively. The diabetic animals subjected to exercise showed decreased alveolar bone loss, lower glycemia, triacylglycerols and glycosylated hemoglobin levels than the controls. Total cholesterol and its fractions (High density lipoprotein-HDL-c, Low density lipoprotein-LDL-c and Very low density lipoprotein-VLDL-c) remained similar among the groups. Animals with PD showed higher levels of TNF-α and lower levels of IL-10, when compared to animals without PD. In diabetic animals with PD, physical exercise decreased TNF-α levels and increased IL-10 levels as well as the IL10/TNF-α ratio. In conclusion, eight weeks of physical exercise improved glycemic control and systemic inflammatory profile, and attenuated alveolar bone loss in rats with DM and PD.

Benefits of Fish Oil Consumption over Other Sources of Lipids on Metabolic Parameters in Obese Rats.

This study evaluated the effect of the consumption of different levels and sources of lipids on metabolic parameters of Wistar rats. Animals were fed with high-fat diet (HFD) containing 20% of lard for 12 weeks to cause metabolic obesity. Subsequently, the animals were divided into six groups and were fed diets with lipid concentrations of 5% or 20% of lard (LD), soybean oil (SO) or fish oil (FO), for 4 weeks. Data were submitted to analysis of variance (two-way) followed by Tukey post hoc test (p < 0.05). The groups that consumed FO showed less weight gain and lower serum levels of triacylglycerol (TAG), total cholesterol and fractions, aspartate aminotransferase (AST) activity, atherogenic index, less amount of fat in the carcass, decreased Lee index and lower total leukocyte counting (p < 0.05). These same parameters were higher in LD treatment (p < 0.05). In the concentration of 20%, carcass fat content, blood glucose levels, as well as alanine aminotransferase (ALT) and gamma glutamyl transferase (GGT) decreased in FO groups (p < 0.05). The SO group had intermediate results regarding the other two treatments (FO and LD). We concluded that fish oil intake was able to modulate positively the metabolic changes resulting from HFD.

Oral microbe-host interactions: influence of ß-glucans on gene expression of inflammatory cytokines and metabolome profile.

BACKGROUND: The aim of this study was to evaluate the effects of ß-glucan on the expression of inflammatory mediators and metabolomic profile of oral cells [keratinocytes (OBA-9) and fibroblasts (HGF-1) in a dual-chamber model] infected by Aggregatibacter actinomycetemcomitans. The periodontopathogen was applied and allowed to cross the top layer of cells (OBA-9) to reach the bottom layer of cells (HGF-1) and induce the synthesis of immune factors and cytokines in the host cells. ß-glucan (10 µg/mL or 20 µg/mL) were added, and the transcriptional factors and metabolites produced were quantified in the remaining cell layers and supernatant. RESULTS: The relative expression of interleukin (IL)-1-α and IL-18 genes in HGF-1 decreased with 10 µg/mL or 20 µg/mL of ß-glucan, where as the expression of PTGS-2 decreased only with 10 µg/mL. The expression of IL-1-α increased with 20 µg/mL and that of IL-18 increased with 10 µg/mL in OBA-9; the expression of BCL 2, EP 300, and PTGS-2 decreased with the higher dose of ß-glucan. The production of the metabolite 4-aminobutyric acid presented lower concentrations under 20 µg/mL, whereas the concentrations of 2-deoxytetronic acid NIST and oxalic acid decreased at both concentrations used. Acetophenone, benzoic acid, and pinitol presented reduced concentrations only when treated with 10 µg/mL of ß-glucan. CONCLUSIONS: Treatment with ß-glucans positively modulated the immune response and production of metabolites.

ß-Glucans (Saccharomyces cereviseae) Reduce Glucose Levels and Attenuate Alveolar Bone Loss in Diabetic Rats with Periodontal Disease.

The objective of this study was to assess the effects of oral ingestion of ß-glucans isolated from Saccharomyces cereviseae on the metabolic profile, expression of gingival inflammatory markers and amount of alveolar bone loss in diabetic rats with periodontal disease. Diabetes mellitus was induced in 48 Wistar rats by intraperitoneal injection of streptozotocin (80 mg/kg). After confirming the diabetes diagnosis, the animals were treated with ß-glucans (by gavage) for 28 days. On the 14th day of this period, periodontal disease was induced using a ligature protocol. ß-glucans reduced the amount of alveolar bone loss in animals with periodontal disease in both the diabetic and non-diabetic groups (p < 0.05). ß-glucans reduced blood glucose, cholesterol and triacylglycerol levels in diabetic animals, both with and without periodontal disease (p < 0.05). Furthermore, treatment with ß-glucans reduced the expression of cyclooxygenase-2 and receptor activator of nuclear factor kappa-B ligand and increased osteoprotegerin expression in animals with diabetes and periodontal disease (p < 0.05). It was concluded that treatment with ß-glucans has beneficial metabolic and periodontal effects in diabetic rats with periodontal disease.

Metabolic effects of B-glucans (Saccharomyces cerevisae) per os administration in rats with streptozotocin-induced diabetes / Efectos metabólicos de los β-glucanos (saccharomyces cerevisiae) a través de la administración oral en ratas con diabetes inducida por estreptozotocina

Introduction: beta-glucans (BG) derived from plant tissues are reported to show metabolic effects. In contrast, those fibers isolated from yeast seem to be more related to immune response modulation. Since diabetic individuals are more susceptible to exacerbation of inflammatory signs, the ingestion of fibers that could conjugate both metabolic and immune effects would be of great importance. Objective: we investigated the effect of BG - Saccharomyses cerevisae - ingestion on glycemic and lipoprotein profile of diabetic rats. Design: twenty-four adult Wistar rats were used, distributed into 4 groups in a design of entirely casualized delineation with a 2 x2 factorial model (with and without diabetes; with and without BG). Diabetes Mellitus was induced by an intraperitoneal injection of 80mg/kg of strepzotocin. Thus, animals with fasting glycemia of over 250mg/dl were considered diabetic. Forty-eight hours after induction, the rats received daily doses of 30 mg/kg of BG or saline solution by gavage during 28 days. Results and discussion: the Groups with DM presented a higher glycemic index and lower C peptide levels than the control groups, in addition to lower weight gain and higher ration consumption, water ingestion and urinary volume. Total cholesterol levels (CT), LDL-C + VLDL-C, plasma triacylglycerides (TAG) and alanine aminotransferase (ALT) were also higher in the diabetic animals (p<0.05). No histopathological hepatic alterations were observed in any of the groups. Furthermore, the diabetic animals present increase in villous:crypt ratio (V:C) in the duodenum, without interference of BG. No alterations in the carcass were observed between the groups. Conclusion: it was concluded that the use of BG significantly reduced the glycemic, TAG and ALT levels, showing its therapeutic potential (AU)

Introdución: los beta-glucanos (BG) derivados de tejidos vegetales se ha informado que muestran efectos metabólicos. Por el contrario, esas fibras aisladas de levadura parecen estar más relacionadas con la modulación de la respuesta inmune. Dado que los individuos con diabetes son más susceptibles a la exacerbación de los signos inflamatorios, la ingestión de fibras sí podría conjugar ambos efectos metabólicos e inmunológicos, lo cual sería de gran importancia. Objetivo: el objetivo de este estudio fue investigar los efectos de la ingestión de los BG —Saccharomyses cerevisiae— en el perfil glucémico y la lipoproteína de ratas diabéticas. Metodos: en el diseño de delineación, totalmente precario, fueron utilizadas 24 ratas Wistar macho adultas distribuidas en cuatro grupos, con un modelo factorial 2x2 (con y sin diabetes, con y sin BG). La diabetes mellitus fue inducida por la inyección intraperitoneal de un 80 mg/kg de estrepzotocina. Por lo tanto, los animales con glucemia en ayunas de más de 250 mg/dl fueron considerados diabéticos. Cuarenta y ocho horas después de la inducción, las ratas recibieron dosis diarias de 30 mg/kg de BG o solución salina mediante alimentación forzada durante 28 días. Resultados y discusión: los grupos con DM presentó el mayor índice glucémico y menores niveles de péptido C que los grupos de control, además de reducir el aumento de peso y un mayor consumo de la ración, la ingestión de agua y el volumen urinario. Los niveles de colesterol total (CT), LDL-C + VLDL-C, triacilglicéridos plasmáticos (TAG) y alanina aminotransferasa (ALT) también fueron más altos en los animales diabéticos (p<0,05), y había alteraciones en los niveles de HDL-C. La ingestión de BG redujo las concentraciones de glucosa en sangre (30%), TAG (32%) y ALT (41%) (p<0.05). No se observaron alteraciones hepáticas en ninguno de los grupos. Además, los animales diabéticos presentaron un aumento de la relación cripta:vellosidades (V:C) en el duodeno, sin interferencia de BG. No se observaron alteraciones en la carcasa entre los grupos. Conclusión: se concluyó que el uso de BG redujo significativamente la glucemia, los niveles de TAG Y ALT, mostrando su potencial terapéutico (AU)

Comparação de métodos para mensuração da perda óssea alveolar periodontal em ratos submetidos aestresse / Comparison of methods for measurement of periodontal bone loss in rats submitted to stress

Objetivo: Comparar os métodos radiográfico, morfométrico e histométrico para avaliação da perdado osso alveolar em ratos com doença periodontal induzida por ligadura e submetidos a estresse crônico.Materiais e Métodos: Ratos Wistar (Rattus norvegicus albinus) machos adultos foram distribuídos emdelineamento inteiramente casualizado em esquema fatorial 2x2 (com e sem doença periodontal (DP), come sem estresse crônico (EC)) com oito repetições em cada grupo. O EC foi realizado por meio de imobilizaçãodiária por 2,5 horas por 30 dias, enquanto que a DP foi induzida com o protocolo de ligadura no primeiro molarmandibular direito e esquerdo nos últimos 14 dias. Após esse período, os ratos foram eutanasiados. Resultados:Na análise radiográfica e histométrica foi determinado o suporte ósseo periodontal (SOP). Adicionalmente,na análise histométrica foi calculada a perda do osso alveolar (POA) e a perda de inserção epitelial (PIE) naface distal do primeiro molar. Na análise morfométrica, a perda do osso alveolar foi obtida pela determinaçãodas distâncias lineares da junção cemento-esmalte (JEC) até crista óssea (CO) no centro das raízes linguaise distais. Observou-se aumento dos níveis de corticosterona (p<0,05) nos animais submetidos a imobilizaçãoe a perda do osso alveolar foi superior (p<0,05) nos animais que receberam a ligadura, independentemente daassociação com estresse, enquanto que a imobilização isoladamente não influenciou esses parâmetros. Houvecorrelação significativa entre as três variáveis utilizadas para avaliação da perda óssea (p<0,05). Conclusão:Métodos histométricos, radiográficos e morfométricos não apresentaram resultados divergentes na avaliaçãoda perda óssea alveolar em ratos com DP e submetidos ao EC.

Influence of integral and decaffeinated coffee brews on metabolic parameters of rats fed with hiperlipidemic diets

The objective of this study was to evaluate the influence of integral and decaffeinated coffee brews (Coffea arabica L and C. canephora Pierre) on the metabolic parameters of rats fed with hyperlipidemic diet. Thirty male Wistar rats (initial weight of 270 g ± 20 g) were used in the study, which were divided into six groups five each. The treatments were normal diet, hyperlipidemic diet, hyperlipidemic diet associated with integral coffee arabica or canephora brews (7.2 mL/kg/day) and hyperlipidemic diet associated to decaffeinated arabica, or canephora brews, using the same dosage. After 41 days, performance analyses were conducted.The rats were then euthanized and the carcasses were used for the analysis of dried ether extract and crude protein. Fractions of adipose tissue were processed for histological analysis. There was a reduction in weight gain and accumulation of lipids in the carcasses, lower diameter of adipocytes and a lower relative weight of the liver and kidneys of rats fed with hyperlipidemic diet associated with integral coffee brew. Integral coffee brew reduced the obesity in the rats receiving hyperlipidemic diet, but the same effect did not occur with the decaffeinated types.

Effect of probiotic administration on the immune response: a systematic review of experimental models in rats

The probiotic influence on the immune system, especially under pathogenic challenge conditions, still remains controversial. To address this, a systematic review of current studies concerning the efficacy of probiotics on the immune response of rats subjected to experimental challenges was conducted. The survey was conducted using PubMed, ISI Web of Science and Scielo databases. Only studies which tested probiotics in vivo in rats were included. The experimental design, methodological quality, and results of the articles were analyzed. In total 21 articles were selected for this study. The most commonly used microorganisms in the experiments were those of the genus Lactobacillus, which was reported in 12 articles. The second most often used genus was Bifidobacterium (B. animalis and B.longum). In general, the probiotics use against experimental pathogenic challenges was successful: 86% of the selected articles reported a beneficial effect on the immune response associated with the use of probiotics.