Sitagliptin inhibits lipopolysaccharide-induced inflammatory response in human gingival fibroblasts by blocking nuclear factor-κB signaling pathway / 华西口腔医学杂志

OBJECTIVES@#This study was performed to clarify the effects of sitagliptin on @*METHODS@#Healthy gingival samples were collected from the donors. HGFs were isolated with enzymic digestion method and identified. The effects of LPS and sitagliptin on cell viability were detected by cell-counting kit-8 (CCK8). The mRNA levels of inflammatory cytokines, namely, interleukin (IL)-6, IL-8, C-C motif ligand 2 (CCL2), and superoxide dismutase 2 (SOD2), were evaluated by quantity real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immune sorbent assay (ELISA) was used to measure the secretion protein levels of IL-6, IL-8, and CCL2. Western blot analysis was used to further investigate the activation of nuclear factor (NF)-κB signaling pathway. The effect of NF-κB pathway inhibitor BAY11-7082 on LPS-induced HGF inflammatory cytokines at the gene level was verified by qRT-PCR.@*RESULTS@#Low concentrations of sitagliptin (0.1, 0.25, and 0.5 µmol·L@*CONCLUSIONS@#Sitagliptin could significantly inhibit LPS-induced HGF inflammatory response by blocking the NF-κB signaling pathway activation.

Effects of 1, 25-dihydroxyvitamin D3 on experimental periodontitis and AhR/NF-κB/NLRP3 inflammasome pathway in a mouse model

Abstract Vitamin D has been known to have important regulatory functions in inflammation and immune response and shows inhibitory effects on experimental periodontitis in animal models. However, the potential mechanism has yet to be clarified. Recent studies have highlighted Aryl hydrocarbon receptor (AhR) and its downstream signaling as a crucial regulator of immune homeostasis and inflammatory regulation. Objective: This study aimed to clarify the effect of 1,25-dihydroxyvitamin D3 (VD3) on experimental periodontitis and AhR/nuclear factor-κB (NF-κB)/NLR pyrin domain-containing 3 (NLRP3) inflammasome pathway in the gingival epithelium in a murine model. Methodology: We induced periodontitis in male C57BL/6 wild-type mice by oral inoculation of Porphyromonas gingivalis (P. gingivalis), and subsequently gave intraperitoneal VD3 injection to the mice every other day for 8 weeks. Afterwards, we examined the alveolar bone using scanning electron microscopy (SEM) and detected the gingival epithelial protein using western blot analysis and immunohistochemical staining. Results: SEM images demonstrated that alveolar bone loss was reduced in the periodontitis mouse model after VD3 supplementation. Western blot analyses and immunohistochemical staining of the gingival epithelium showed that the expression of vitamin D receptor, AhR and its downstream cytochrome P450 1A1 were enhanced upon VD3 application. Additionally, VD3 decreased NF-κB p65 phosphorylation, and NLRP3, apoptosis-associated speck-like protein, caspase-1, interleukin-1β (IL-1β) and IL-6 protein expression. Conclusions: These results implicate the alleviation of periodontitis and the alteration of AhR/NF-κB/NLRP3 inflammasome pathway by VD3 in the mouse model. The attenuation of this periodontal disease may correlate with the regulation of AhR/NF-κB/NLRP3 inflammasome pathway by VD3.

Effects of TiO2 NPs coating-titanium for fibroblast adhesion / Efectos del recubrimiento de NPs de TiO2 sobre placas de titanio para la adhesión de fibroblastos

The objective of this study was to determine the effects of coating nanoparticles of titanium dioxide (TiO2 NPs) and irradiation -UV on plates of titanium (Ti) for the adhesion and proliferation of human gingival fibroblasts (HGF). A total of 15 Ti plates were divided into three groups (n = 5); (i) control Ti, (ii) experimental: Ti+TiO2 NPs, (iii) experimental: Ti+TiO2 NPs+UV. The plates were analyzed with atomic force microscopy (AFM) and the roughness (Ra and Rmax) was determined. UV irradiation was performed for 20 min. HGF were subcultured in DMEM+10 % fetal bovine serum (FBS) at 37 °C with 5 % CO2. 2x106 cells/mL were inoculated on the plates and incubated for 1 h and washed with phosphate buffer saline (PBS). In the case of cell proliferation, cells were incubated for further 24 h more. Cell viability was determined with the MTT method, the formazan was dissolved with dimethylsulfoxide (DMSO) and analyzed at 540 nm. Experiments were performed of three independent experiments and data were analyzed by Kruskall-Wallis and multiple comparison of Mann-Whitney test. The surface topography of samples corresponded as follow: Ti (Ra= 0,492 µm y Rms= 0.640 µm), Ti+NPs TiO2, (Ra= 0.55 µm y Rms= 0.714 µm), respectively. The coating with TiO2 NPs significantly (p <0.05) increased the adhesion and proliferation of HGF compared with the group. The modification of Ti plates by coated with TiO2 NPs significantly increased adhesion and proliferation of HGF with the formation of a hydrophilic surface which favors the humectancy. This treatment may be reported here convenient to accelerate osseointegration of dental implants based titanium.

El objetivo fue determinar los efectos del recubrimiento con nanopartículas de dióxido de titanio (TiO2 NPs) e irradiación UV sobre placas de titanio (Ti) para la adhesión y proliferación de fibroblastos gingivales humanos (FGH). Un total de 15 placas de Ti se dividieron en tres grupos (n= 5); (i) control Ti, (ii) experimental Ti+NPs TiO2, (iii) experimental: Ti+NPs TiO2+UV. Las placas fueron analizadas en microscopía de fuerza atómica (MFA) y se determinó la rugosidad (Ra y Rmax). La irradiación con UV se realizó durante 20 min. FGH fueron subcultivados en DMEM+10 % de suero fetal bovino a 37 °C con 5 % de CO2. 2x106 células/mL fueron inoculadas sobre las placas e incubadas durante 1 h, se lavaron con solución salina de buffer fosfato. En el caso de la proliferación celular, las células se incubaron por 24 h más. La viabilidad celular se determinó con el método de MTT, el formazan fue disuelto con dimetilsulfoxido y se analizó a 540 nm. Los experimentos se realizaron a partir de tres experimentos independientes y los datos se analizaron por Kruskall-Wallis y por comparación múltiple de Mann-Whitney. La topografía de la superficie de las muestras correspondio de la siguiente manera: Ti (Ra= 0,492 µm y Rms= 0,640 µm), Ti+NPs TiO2, (Ra= 0,55 µm y Rms= 0,714 µm), respectivamente. El recubrimiento con NPs TiO2 aumentó significativamente la adhesión y proliferación de HGF en comparación con el grupo de Ti control (p <0,05). La modificación de la superficie de las placas de Ti recubiertas con NPs TiO2 aumentó significativamente la adhesión y proliferación de HGF con la formación de una superficie hidrófila que favorece la humectancia. Este tratamiento aquí informado tal vez sea un método conveniente para acelerar el proceso de la osteointegración de los implantes dentales a base de titanio.

Immunoexpression of HIF-1α and VEGF in Periodontal Disease and Healthy Gingival Tissues

Abstract Hypoxia-inducible factor 1 alpha (HIF-1α) and vascular endothelial growth factor (VEGF) are proteins that stimulate the proliferation and migration of endothelial cells. These proteins have been described in many pathologic and inflammatory conditions, but their involvement in the development of periodontitis has not been thoroughly investigated. This study compared the immunohistochemical expression of these proteins, involved in angiogenesis and hypoxia, by imunnostained inflammatory and endothelial cells in periodontal disease and healthy gingival tissues. Gingival tissue samples were divided as follows: 30 samples with chronic periodontitis, 30 with chronic gingivitis, and 30 of healthy gingiva. Results were analyzed statistically by the Kruskal-Wallis, Mann-Whitney and Spearman correlation tests (p=0.01). Inflammatory and endothelial cells were found to express these proteins. Periodontitis showed median percentage of HIF-1α-positive cells of 39.6%, 22.0% in cases of gingivitis and 0.9% in the healthy gingiva group (p=0.001). For VEGF, median percentage of immunopositive cells was 68.7% for periodontitis, 66.1% in cases for gingivitis, and 19.2% for healthy gingival specimens (p<0.001). Significant correlation between VEGF and HIF-1α was also observed in healthy gingiva (p<0.001).The increased expression of HIF-1αα and VEGF in periodontitis, compared to gingivitis and healthy gingiva, suggests possible activation of the HIF-1α pathway in advanced periodontal disease. The correlation between HIF-1α and VEGF expression in healthy gingiva suggests a physiological function for these proteins in conditions of homeostasis. In periodontal disease, HIF-1 and VEGF expression may be regulated by other factors, in addition to hypoxia, such as bacterial endotoxins and inflammatory cytokines.

Resumo O fator induzível por hipóxia 1 alfa (HIF-1α) e o fator de crescimento endotelial vascular (VEGF) são proteínas que estimulam a proliferação e a migração de células endoteliais. Estas proteínas têm sido descritas em muitas condições patológicas e inflamatórias, mas o envolvimento dessas no desenvolvimento de periodontite não foi completamente investigado. Este estudo comparou a expressão imunohistoquímica destas proteínas, envolvidas na angiogênese e hipóxia, na doença periodontal e em tecidos gengivais saudáveis por meio de contagem de células inflamatórias e endoteliais imunomarcadas. As amostras de tecido gengival foram divididas da seguinte forma: 30 amostras com periodontite crônica, 30 com gengivite crônica e 30 de gengiva saudável. Os resultados foram analisados estatisticamente pelos testes de Kruskal-Wallis e Mann-Whitney (p=0.01). As células inflamatórias e endoteliais foram positivas para estas proteínas. A porcentagem média de células positivas para HIF-1α foi de 39,6% nos casos de periodontite, 22,0% nos casos de gengivite e de 0,9% no grupo de gengiva saudável (p = 0,001). A porcentagem média de células imunopositivas para o VEGF foi de 68,7% nos casos de periodontite, 66,1% nos casos de gengivite, e 19,2% em espécimes gengivais saudáveis (p<0,001). Correlação significativa entre o VEGF e HIF-1α foi observada em gengival. A expressão elevada do HIF-1α e VEGF em periodontite, comparada a gengivite e gengiva saudável, sugere ativação da via do HIF-1α, na doença periodontal avançada. A correlação entre o HIF-1α e expressão de VEGF na gengiva saudável, sugere uma função fisiológica para estas proteínas em condições de homeostase. Na doença periodontal, a expressão de HIF-1α e VEGF pode ser regulada por outros fatores, além da hipóxia, tais como endotoxinas bacterianas e citocinas inflamatórias.

Osteopontin expression in reactive lesions of gingiva

Reactive proliferations of the gingiva comprise lesions such as pyogenic granuloma (PG), inflammatory fibroepithelial hyperplasia (IFH), peripheral ossifying fibroma (POF), and peripheral giant cell lesion. Osteopontin (OPN) has a dual role, it promotes mineralization when it is bound to solid substrate, and on the other hand, it inhibits mineralization when it is seen in association with solution. Objectives The study aimed to evaluate the expression of osteopontin in normal gingival tissue and different types of focal reactive proliferations of gingival tissue, and its role in the development of calcification within it. Material and Methods The presence and distribution of osteopontin was assessed using immunohistochemistry in five cases of normal gingival tissue and 30 cases of focal reactive proliferations of gingiva. Results There was no expression of osteopontin in normal subjects. Few cases of pyogenic granuloma, inflammatory fibroepithelial hyperplasia, and all the cases of peripheral ossifying fibroma showed positivity for osteopontin in the inflammatory cells, stromal cells, extracellular matrix, and in the calcifications. Conclusion The expression of osteopontin in all the cases of peripheral ossifying fibroma speculates that the majority of the cases of peripheral ossifying fibroma originate from the periodontal ligament cells. The treatment modalities for peripheral ossifying fibroma should differ from other focal reactive proliferations of gingiva. .

Activity of platelet activating factor acetylhydrolase following phase I periodontal therapy / Actividad de la acetilhidrolasa del factor activador de las plaquetas tras la fase I de la terapia periodontal

OBJECTIVE: Elevated levels of platelet activating factor (PAF), a potent inflammatory mediator, in perio-dontal disease and decreased PAF levels following periodontal surgical therapy have been previously detected in gingival tissues and gingival crevicular fluid (GCF). Platelet activating factor acetylhydrolase (PAF-AH) is a calcium-independent phospholipase A2 that catalyses the hydrolysis of PAF, thereby inactivating this mediator. The hypothesis, a relationship between activity of PAF-AH and healing following periodontal therapy, was tested by detecting activity of PAF-AH in GCF samples collected from sites that had undergone phase I periodontal therapy with generalized chronic periodontitis. METHODS: Twenty patients with generalized chronic periodontitis were divided into two groups (n = 10): group 1 with probing pocket depth (PPD) 4-5 mm and group 2 with PPD > 6-8 mm. Clinical parameters were recorded and GCF was sampled before phase I periodontal therapy and at the 2nd, 7th, 14th, 21st and 28th day follow-up evaluation visits. Activity of PAF-AH in GCF was analysed by enzyme-linked immunosorbent assay (ELISA). RESULTS: Probing pocket depth at the 21st and 28th day in group 1, and PPD at the 14th, 21st and 28th day in group 2 were significantly decreased when compared to the baseline values (p < 0.001). Activity of PAF-AH (µmol/ml) was significantly decreased at the 7th, 14th, 21st and 28th day following phase I periodontal therapy in both groups 1 and 2 compared to the baseline values (p < 0.05). CONCLUSION: Platelet activating factor acetylhydrolase is detectable in GCF by ELISA and showed a continuous decrease following phase I periodontal therapy. Changes in the PAF-AH activity would be a progressive marker of periodontal healing to evaluate the success of periodontal therapies.

OBJETIVO: Niveles elevados del factor activador de las plaquetas (PAF) - un potente mediador inflamatorio en la enfermedad periodontal - y niveles disminuidos de PAF tras la terapia quirúrgica periodontal, han sido detectados previamente en los tejidos gingivales y el fluido crevicular gingival (FCG). La acetilhidrolasa del factor activador de las plaquetas(PAF-AH) es una fosfolipasa A2 independiente del calcio, que cataliza la hidrólisis de PAF, inactivando así este mediador. La hipótesis - la existencia de una relación entre la actividad de PAF-AH y la curación tras la terapia periodontal - fue sometida a comprobación mediante la detección de la actividad de PAF-AH en muestras de FCG recogidas de sitios que pasaron por la fase I de la terapia periodontal por periodontitis crónica generalizada. MÉTODOS: Veinte pacientes con periodontitis crónica generalizada fueron divididos en dos grupos (n = 10): grupo 1 con una profundidad de bolsa al sondeo (PPD) de 4-5 mm, y grupo 2 con PPD = 6-8 mm. Se registraron los parámetros clínicos, y se obtuvieron muestras de FCG antes de la fase I de la terapia periodontal, y en las visitas de evaluación de seguimiento los días 2, 7, 14, 21 y 28. La actividad de PAF-AH en FCG se analizó mediante ensayo por inmunoabsorción ligada a enzimas (ELISA). RESULTADOS: La profundidad de bolsa al sondeo los días 21 y 28 en el grupo 1, y PPD los días 14, 21 y 28 en el grupo 2 se vieron disminuidas significativamente cuando se les comparó con los valores iniciales (p < 0.001). La actividad de PAF-AH (µmol/ml) disminuyó significativamente los días 7, 14, 21 y 28 tras la fase I de la terapia periodontal en ambos grupos 1 y 2 en comparación con los valores al inicio del estudio (p< 0.05). CONCLUSIÓN: La acetilhidrolasa del factor activador de las plaquetases detectable en FCG mediante ELISA, y mostró una disminución continua tras la fase I de la terapia periodontal. Los cambios en la actividad de la PAF-AH sería un marcador progresivo de la curación periodontal para evaluar el éxito de las terapias periodontales.

Estudo da expressão e produção de componentes do sistema renina-angiotensina por fibroblastos de gengiva e ligamento periodontal humanos / Study of expression and production of the renin-angiotensin system components by gingival and periodontal ligament human fibroblasts

O Sistema Renina-angiotensina (SRA), e um sistema capaz de gerar hormonios peptideos com grande impacto na regulacao cardiovascular e na patogenese das doencas cardiovasculares. Este sistema opera, por meio das acoes da Angiotensina II, tanto em nivel sistemico (endocrino) quanto tecidual (local, paracrino/autocrino) controlando importantes funcoes, varias delas relacionadas a facilitacao da instalacao e progressao do processo inflamatorio. Por este motivo, a producao desta proteina nos tecidos pode estar relacionada a patogenese de muitas doencas, dentre elas a doenca periodontal (DP), tendo em vista seu carater infeccioso-inflamatorio e os achados da literatura que mostram que a inibicao da formacao de Ang II, diminui a perda óssea da DP em animais. Desta forma, o presente trabalho teve como objetivos: Avaliar in vitro, a) A expressao de componentes do SRA (ANGT, RENINA, ECA, ECA-2, AT1, AT2 e Mas) por fibroblastos de gengiva e ligamento periodontal humanos, por RT-qPCR; b) A producao de componentes do SRA (RENINA, ECA, ECA-2) no sobrenadante de culturas de fibroblastos de gengiva e ligamento periodontal humanos, por ELISA; c) A producao dos receptores do SRA (AT1, AT2 e Mas), nestes fibroblastos, por Imunofluorescencia e d) Se a expressao e a producao dos componentes do SRA por fibroblastos de gengiva e ligamento periodontal humanos, se alteram com a estimulacao por LPS de P. gingivalis e E. coli. Apos a coleta, os dados foram analisados com o auxilio do programa GraphPad Prism 5.0. por meio da analise de variancia a 2 criterios (ANOVA-two way) seguida do pos teste de Bonferroni, com nivel de significancia de 5% para a verificacao das possíveis diferencas. Foi detectada a expressao genica para alguns dos componentes do SRA (ANGT, RENINA, ECA, AT1) por fibroblastos tanto de gengiva quanto de ligamento periodontal. Foi detectada ainda uma expressao genica diferenciada entre fibroblastos de gengiva e ligamento periodontal para...

The Renin-angiotensin system (RAS) can generate hormones that have a high-impact on cardiovascular regulation as well as in the pathogenesis of cardiovascular disease. This system acts through both systemic (endocrine) and local (paracrine/autocrine) effects of Angiotensin II, controlling important functions related to the facilitation of installation and progression of the inflammatory process. For this reason, this proteins production in tissues can be associated to the pathogenesis of many diseases, including periodontal disease (PD). In the PD setting, a infectious-inflammatory characterized disease, the literature findings shows that inhibition of the Ang II formation can decrease the bone loss in animals. In this context, the aims of the present study were: to investigate in vitro: a) the expression of RAS components (ANGT, RENIN, ECA, ECA- 2, AT1, AT2 and Mas) by human gingival and periodontal ligament fibroblasts by RT-qPCR; b) the production of RAS receptors (AT1, AT2 and Mas) by human cultured gingival and periodontal ligament fibroblasts by Immunofluorescence and d) the production of RAS components (RENIN, ECA, ECA-2) if the expression and production of RAS components by gingival and periodontal ligament fibroblasts modify under P. gingivalis and E. coli LPS stimulation. After collected, the data were analysed using GraphPad Prism 5.0, by the two way ANOVA followed by Bonferroni post test with a significance level of 5%. Gene expression was detected for some of the RAS components (ANGT, RENIN, ECA, AT1) by both gingival and periodontal ligament fibroblasts. It was detected a differential gene expression between gingival and periodontal ligament fibroblasts for ECA, being significantly higher in gingival fibroblasts. There was a stain in Immunofluorescence compatible with the production of RAS receptors (AT1 and Mas). It must be noted that the...

Estudo da expressão e produção de componentes do sistema renina-angiotensina por fibroblastos de gengiva e ligamento periodontal humanos / Study of expression and production of the renin-angiotensin system components by gingival and periodontal ligament human fibroblasts

O Sistema Renina-angiotensina (SRA), e um sistema capaz de gerar hormonios peptideos com grande impacto na regulacao cardiovascular e na patogenese das doencas cardiovasculares. Este sistema opera, por meio das acoes da Angiotensina II, tanto em nivel sistemico (endocrino) quanto tecidual (local, paracrino/autocrino) controlando importantes funcoes, varias delas relacionadas a facilitacao da instalacao e progressao do processo inflamatorio. Por este motivo, a producao desta proteina nos tecidos pode estar relacionada a patogenese de muitas doencas, dentre elas a doenca periodontal (DP), tendo em vista seu carater infeccioso-inflamatorio e os achados da literatura que mostram que a inibicao da formacao de Ang II, diminui a perda óssea da DP em animais. Desta forma, o presente trabalho teve como objetivos: Avaliar in vitro, a) A expressao de componentes do SRA (ANGT, RENINA, ECA, ECA-2, AT1, AT2 e Mas) por fibroblastos de gengiva e ligamento periodontal humanos, por RT-qPCR; b) A producao de componentes do SRA (RENINA, ECA, ECA-2) no sobrenadante de culturas de fibroblastos de gengiva e ligamento periodontal humanos, por ELISA; c) A producao dos receptores do SRA (AT1, AT2 e Mas), nestes fibroblastos, por Imunofluorescencia e d) Se a expressao e a producao dos componentes do SRA por fibroblastos de gengiva e ligamento periodontal humanos, se alteram com a estimulacao por LPS de P. gingivalis e E. coli. Apos a coleta, os dados foram analisados com o auxilio do programa GraphPad Prism 5.0. por meio da analise de variancia a 2 criterios (ANOVA-two way) seguida do pos teste de Bonferroni, com nivel de significancia de 5% para a verificacao das possíveis diferencas. Foi detectada a expressao genica para alguns dos componentes do SRA (ANGT, RENINA, ECA, AT1) por fibroblastos tanto de gengiva quanto de ligamento periodontal. Foi detectada ainda uma expressao genica diferenciada entre fibroblastos de gengiva e ligamento periodontal para...

The Renin-angiotensin system (RAS) can generate hormones that have a high-impact on cardiovascular regulation as well as in the pathogenesis of cardiovascular disease. This system acts through both systemic (endocrine) and local (paracrine/autocrine) effects of Angiotensin II, controlling important functions related to the facilitation of installation and progression of the inflammatory process. For this reason, this proteins production in tissues can be associated to the pathogenesis of many diseases, including periodontal disease (PD). In the PD setting, a infectious-inflammatory characterized disease, the literature findings shows that inhibition of the Ang II formation can decrease the bone loss in animals. In this context, the aims of the present study were: to investigate in vitro: a) the expression of RAS components (ANGT, RENIN, ECA, ECA- 2, AT1, AT2 and Mas) by human gingival and periodontal ligament fibroblasts by RT-qPCR; b) the production of RAS receptors (AT1, AT2 and Mas) by human cultured gingival and periodontal ligament fibroblasts by Immunofluorescence and d) the production of RAS components (RENIN, ECA, ECA-2) if the expression and production of RAS components by gingival and periodontal ligament fibroblasts modify under P. gingivalis and E. coli LPS stimulation. After collected, the data were analysed using GraphPad Prism 5.0, by the two way ANOVA followed by Bonferroni post test with a significance level of 5%. Gene expression was detected for some of the RAS components (ANGT, RENIN, ECA, AT1) by both gingival and periodontal ligament fibroblasts. It was detected a differential gene expression between gingival and periodontal ligament fibroblasts for ECA, being significantly higher in gingival fibroblasts. There was a stain in Immunofluorescence compatible with the production of RAS receptors (AT1 and Mas). It must be noted that the...

Comparison of inflammatory microRNA expression in healthy and periodontitis tissues

MicroRNAs (miRNAs) are short RNA molecules that negatively regulate gene expression primarily by degrading target mRNA or inhibit the translation of protein product. Recently, many reports have shown the altered miRNA expression in various diseases. However, there are no reports on miRNA expression related to periodontitis. Thus, this study aimed to compare the miRNAs differentially expressed in healthy and chronic periodontitis tissues and to determine the miRNAs closely associated with chronic periodontitis. To find out the miRNAs differentially induced in healthy and chronic periodontitis tissues, miRNA microarray was carried out and the expression of miRNAs was confirmed by real-time PCR. According to miRNA microarray analyses, six miRNA genes, let-7a, let-7c, miR-130a, miR301a, miR-520d, and miR-548a, were up-regulated more than 8 fold compared to the healthy gingiva. The expression of twenty-two miRNAs was increased more than 4 fold. Among these miRNAs, eight miRNAs which are known to be closely related to inflammation were selected. Six of these miRNA genes, miR-181b, miR-19b, miR-23a, miR-30a, miR-let7a, and miR-301a, were amplified successfully and increased much more in periodontitis gingivae than in healthy ones. In summary, this study indicate that six miRNAs up-regulated in periodontitis gingiva may play a key role in chronic periodontitis.

Correlation between leptin and the health of the gingiva: A predictor of medical risk.

Context: Over the past decade, a growing body of scientific evidence has suggested an exquisite association between oral infection and systemic diseases (e.g. atherosclerosis, cardiovascular diseases, premature or low birth weight babies, pulmonary diseases, etc.) and also between systemic diseases (e.g. arthritis, diabetes, HIV infection and osteoporosis) and oral and craniofacial diseases and disorders. Leptin is a hormone secreted by the adipocytes in varying quantities and regulates the body weight. The present study was undertaken in the context of knowing the role of leptin in the inflammatory process occurring in the gingiva as the disease progressed from gingivitis to periodontitis. Aims: The present study was done to correlate the concentrations of leptin and interleukin (IL)-6 within the gingiva in healthy, gingivitis and periodontitis groups of patients and to correlate gingival leptin and IL-6 concentrations with plasma leptin and IL-6 concentrations in the healthy, gingivitis and periodontitis groups of patients. Settings and Design: This was a cross-sectional study and was carried out on the patients from the out-patient department of Periodontics in A B Shetty Memorial Institute of Dental Sciences. Patients and Methods: Seventy-five patients in the age group of 18-60 years were selected and grouped based on the gingival index (Loe and Sillness) and their clinical attachment levels into healthy, gingivitis and periodontitis groups. Leptin and IL-6 levels were estimated within gingiva and the plasma of each subject using an enzyme-linked immunosorbent assay kit. The results of this study were tabulated and subjected to statistical analysis. Mean and the standard deviation were calculated using analysis of variance Fisher's F-test and then the results were subjected to Tukey's Honest significance difference method for multiple comparison among the three groups. Correlation among the three groups was estimated using Pearson's correlation analysis. Results: Results showed a statistically significant decrease in the concentration of gingival leptin and a statistically significant increase in the concentration of plasma leptin as the gingival disease progressed. Conclusion: It was concluded that as the gingival disease progressed, the gingival leptin concentration decreased, whereas the plasma leptin concentration increased, indicating a possible correlation between leptin concentration in the gingiva and the risk of developing systemic disease like the cardiovascular disease.

Melanin: A scavenger in gingival inflammation.

Background: One of the major direct or indirect targets of ultraviolet exposure of skin is the melanocyte or the melanin -forming cell. Epidermal melanocytes act as a trap for free radicals. Based on the protective role of melanocytes in medical literature, the role of melanin pigmentation in gingiva needs to be elucidated. Periodontal pathogens and their products demonstrate the ability to induce the generation of reactive oxygen species. Hence purpose of this study was to unravel the protective role of melanin (if any) against the gingival inflammation. Materials and Methods: A total of 80 subjects; 20 in each group were selected. The selection of subjects regarding gingival pigmentation was based on Dummett's scoring criteria 0, 3. A complete medical, dental history and an informed consent were obtained from the patients. After evaluation of clinical parameters the GCF was collected using microcapillary pipettes at the selected sites. IL-1β levels were quantitated using ELISA. Results: In non-pigmented healthy and gingivitis groups, there was a positive correlation between plaque index, gingival index and bleeding index versus IL-1β level: indicating an increase in the biochemical mediator of inflammation corresponding to an increase in the clinical parameters of inflammation. Also a positive correlation was found between the gingival index and bleeding index versus the IL-1β levels in the pigmented healthy group. The pigmented gingivitis groups showed a negative correlation between the plaque index, gingival index and bleeding index. Conclusions: The clinical markers of inflammation such as gingival index, bleeding index was of low numerical value in pigmented group than in the non-pigmented group, supposedly due to the protective action of melanin. The negative correlation of clinical markers of inflammation to the IL-1β levels in the pigmented gingivitis group could possibly be attributed to the protective role of melanins.

Caracterização do sistema renina-angiotensina local no tecido gengival humano sadio e com doença periodontal / Characterization of the local human renin-angiotensin system in healthy and periodontally-affected ginvgival tissue

A doença periodontal (DP) compreende um grupo de lesões que afetam os tecidos periodontais de proteção (gengivite) e suporte (periodontite), envolvendo a participação de células residentes, células estruturais e mediadores inflamatórios. Pesquisas recentes do laboratório mostraram a existência de um Sistema Renina-Angiotensina (SRA) local no tecido gengival de ratos e sugeriram que o SRA pode participar do início e da progressão da DP. Portanto, os objetivos deste trabalho foram investigar no tecido gengival humano com saúde clínica (SG, n=12), com gengivite (G, n = 10) e com periodontite (P, n=12): 1) a existência e eventuais diferenças na expressão e localização dos componentes do SRA local; 2) in vitro, a funcionalidade deste possível SRA local quanto à formação de peptídeos do SRA. Após a coleta dos tecidos gengivais, foram utilizadas as seguintes técnicas: contagem celular de infiltrado inflamatório, reação em cadeia da polimerase quantitativa (qPCR), imunoistoquímica, ensaio fluorimétrico para medida da atividade da enzima conversora de Ang I (ECA) e cromatografia líquida de alto desempenho de fase reversa (HPLC). Os dados foram analisados por meio de ANOVA a 1 e 2 critérios e adotado nível de significância de 5%. Houve expressão gênica de RNAm sem diferenças estatísticas entre as três condições testadas para angiotensinogênio, renina, ECA, ECA2, receptor de Ang I tipo 1(AT1) e receptor do tipo MAS. Houve imunomarcação para os receptores de angiotensina AT1 e AT2 sem diferenças estatísticas entre as três condições testadas. Os testes fluorimétricos mostraram maior atividade da ECA nas amostras afetadas por gengivite em comparação às amostras com saúde gengival (p<0,05). Nos ensaios de HPLC, quando os homogenatos de tecido gengival foram incubados com Ang I, houve formação de Ang 1-7, Ang 1-9 e Ang II. Para as formações de Ang 1-7 e Ang II não houve diferenças estatísticas entre as três condições clínicas, enquanto que para Ang 1-9 houve maior...

Periodontal disease (PD) comprises a group of lesions that affect protection (gingivitis) and support periodontal tissues (periodontitis) involving the participation of resident and structural cells as well as inflammatory mediators. Recent research in our laboratory showed the existence of a local gingival renin-angiotensin system (RAS) in rats and suggested that it might participate in the initiation and progression of PD. Therefore, the aims of this study were to investigate in human gingival tissue under three conditions, clinically healthy (HG, n = 12), gingivitis (G) and periodontitis (P): 1) the existence and differences in the expression and localization of the local RAS components; 2) the in vitro functionality of this local RAS regarding the formation of RAS peptides. After surgical procedure the human gingival tissue was analyzed using the following techniques: inflammatory cells counting, quantitative real-time polymerase chain reaction (qPCR), immunohistochemistry, fluorimetric tests to measure Angiotensin converting enzyme (ACE) activity and reverse phase high performance liquid chromatography (HPLC). Data were submitted to 1 and 2 way ANOVA with significance level established at 5%. There was genic expression (mRNA) for angiotensinogen, renin, ACE, ACE2, AT1 and Mas receptors, without statistically significant difference between all the three conditions analyzed. There was positive immunostaining for AT1 and AT2 receptors in all three conditions without statistically significant difference. Fluorimetric assays showed increased ACE activity in the samples affected by gingivitis as compared to healthy controls (p<0.05). In HPLC assays there was release of Ang-1-7, Ang-1-9 and Ang II after incubation of gingival tissue homogenates with Ang I. The formation of Ang-1-7 and Ang II was not statistically significant different between the three conditions whereas in periodotitis group there was an increase in Ang-1-9 formation when compared to...

Caracterização do sistema renina-angiotensina local no tecido gengival humano sadio e com doença periodontal / Characterization of the local human renin-angiotensin system in healthy and periodontally-affected ginvgival tissue

A doença periodontal (DP) compreende um grupo de lesões que afetam os tecidos periodontais de proteção (gengivite) e suporte (periodontite), envolvendo a participação de células residentes, células estruturais e mediadores inflamatórios. Pesquisas recentes do laboratório mostraram a existência de um Sistema Renina-Angiotensina (SRA) local no tecido gengival de ratos e sugeriram que o SRA pode participar do início e da progressão da DP. Portanto, os objetivos deste trabalho foram investigar no tecido gengival humano com saúde clínica (SG, n=12), com gengivite (G, n = 10) e com periodontite (P, n=12): 1) a existência e eventuais diferenças na expressão e localização dos componentes do SRA local; 2) in vitro, a funcionalidade deste possível SRA local quanto à formação de peptídeos do SRA. Após a coleta dos tecidos gengivais, foram utilizadas as seguintes técnicas: contagem celular de infiltrado inflamatório, reação em cadeia da polimerase quantitativa (qPCR), imunoistoquímica, ensaio fluorimétrico para medida da atividade da enzima conversora de Ang I (ECA) e cromatografia líquida de alto desempenho de fase reversa (HPLC). Os dados foram analisados por meio de ANOVA a 1 e 2 critérios e adotado nível de significância de 5%. Houve expressão gênica de RNAm sem diferenças estatísticas entre as três condições testadas para angiotensinogênio, renina, ECA, ECA2, receptor de Ang I tipo 1(AT1) e receptor do tipo MAS. Houve imunomarcação para os receptores de angiotensina AT1 e AT2 sem diferenças estatísticas entre as três condições testadas. Os testes fluorimétricos mostraram maior atividade da ECA nas amostras afetadas por gengivite em comparação às amostras com saúde gengival (p<0,05). Nos ensaios de HPLC, quando os homogenatos de tecido gengival foram incubados com Ang I, houve formação de Ang 1-7, Ang 1-9 e Ang II. Para as formações de Ang 1-7 e Ang II não houve diferenças estatísticas entre as três condições clínicas, enquanto que para Ang 1-9 houve maior...

Periodontal disease (PD) comprises a group of lesions that affect protection (gingivitis) and support periodontal tissues (periodontitis) involving the participation of resident and structural cells as well as inflammatory mediators. Recent research in our laboratory showed the existence of a local gingival renin-angiotensin system (RAS) in rats and suggested that it might participate in the initiation and progression of PD. Therefore, the aims of this study were to investigate in human gingival tissue under three conditions, clinically healthy (HG, n = 12), gingivitis (G) and periodontitis (P): 1) the existence and differences in the expression and localization of the local RAS components; 2) the in vitro functionality of this local RAS regarding the formation of RAS peptides. After surgical procedure the human gingival tissue was analyzed using the following techniques: inflammatory cells counting, quantitative real-time polymerase chain reaction (qPCR), immunohistochemistry, fluorimetric tests to measure Angiotensin converting enzyme (ACE) activity and reverse phase high performance liquid chromatography (HPLC). Data were submitted to 1 and 2 way ANOVA with significance level established at 5%. There was genic expression (mRNA) for angiotensinogen, renin, ACE, ACE2, AT1 and Mas receptors, without statistically significant difference between all the three conditions analyzed. There was positive immunostaining for AT1 and AT2 receptors in all three conditions without statistically significant difference. Fluorimetric assays showed increased ACE activity in the samples affected by gingivitis as compared to healthy controls (p<0.05). In HPLC assays there was release of Ang-1-7, Ang-1-9 and Ang II after incubation of gingival tissue homogenates with Ang I. The formation of Ang-1-7 and Ang II was not statistically significant different between the three conditions whereas in periodotitis group there was an increase in Ang-1-9 formation when compared to...

Expression of Toll-like receptors 2 and 4 in gingivitis and chronic periodontitis.

Periodontal disease is the major cause of adult tooth loss and is commonly characterized by a chronic inflammation caused by infection by oral bacteria. Members of Toll-like receptor (TLR) family recognize conserved microbial structures, such as bacterial lipopolysaccharides, and activate signaling pathways that result in immune responses against microbial infections. The aim of the present study was to assess the mRNA expression of TLR-2 and TLR-4 in gingivitis and chronic periodontitis. Gingival tissue samples were collected from patients with chronic periodontitis, gingivitis, and healthy controls. Total RNA was extracted and RT-PCR was done for TLR-2 and TLR-4. The results showed that TLR-2 was significantly increased in gingivitis compared to TLR-4 expression and decreased in chronic periodontitis.

Effects of dimethoate on collagen metabolism in rats.

The effects of three different doses of dimethoate on the collagen metabolism in the tissues of female albino rats were studied by measuring the specific and total activities of 3H-hydroxyproline in the dermal, gingival and uteral collagen fractions and in the urine. Compared to controls, the total activity of 3H-hydroxyproline in the soluble collagen and in the urine at 12 h after the administration of 3H-proline was significantly lower by 44.45 and 58.12 per cent in the higher dose (2.25 mg/100 g body weight) of dimethoate treated groups respectively. The urinary excretion of hydroxyproline and the total activity of urinary 3H-hydroxyproline measured after 28 days of injection of labelled proline were decreased by 45.56 and 32.68 per cent in higher doses of dimethoate treated animals respectively but the excretions of urinary 3H-hydroxyproline were decreased by 6.36 and 2.88 per cent in lower doses of dimethoate (0.56 mg/100 g body weight) treated animals. The results of the present investigation clearly indicate that the synthesis of collagen is decreased in the higher doses of dimethoate treated animals compared to lower doses of dimethoate treated animals. In addition, the rates of catabolism of both soluble and insoluble collagens were decreased in higher doses of dimethoate treated rats. In concludes that the lower doses of dimethoate (0.56 mg) treated rats were less affected than the higher doses of dimethoate (2.25 mg) treated rats.