Effects of Foxp3 gene silencing on the expression of inflammatory cytokines and the proliferation and migration of human periodontal ligament fibroblasts in an inflammatory environment / 华西口腔医学杂志

OBJECTIVES@#This study aimed to clarify the effects of Foxp3 silencing on the expression of inflammatory cytokines in human periodontal ligament cells (hPDLFs) in an inflammatory environment and on cell proliferation and invasiveness, as well as to explore the role of Foxp3 gene in the development of periodontitis.@*METHODS@#An small interfering RNA (siRNA) construct specific for Foxp3 was transfected into hPDLFs. Foxp3 silencing efficiency was verified by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting, and the siRNA with the optimum silencing effect of Foxp3 gene was screened. Using lipopolysaccharide to simulate an inflammatory environment in vitro, CCK-8 detected the effect of silencing Foxp3 on hPDLFs proliferation under inflammatory conditions. Wound-healing experiments and transwell assays were conducted to detect the effect of silencing Foxp3 on hPDLF migration under inflammatory conditions. The expression of the inflammatory cytokines interleukin (IL)-6 and IL-8 was detected by RT-PCR and Western blotting under inflammatory conditions.@*RESULTS@#After siRNA transfection, RT-PCR and Western blotting analyses showed that the expression of Foxp3 mRNA in the Foxp3-si3 group decreased significantly (t=21.03, P<0.000 1), and the protein expression of Foxp3 also decreased significantly (t=12.8, P<0.001). In the inflammatory environment, Foxp3 gene silencing had no significant effect on hPDLFs proliferation (P>0.05), and Foxp3 gene silencing promoted hPDLFs migration (P<0.05). Moreover, the expression of IL-6 and IL-8 increased (P<0.05).@*CONCLUSIONS@#In an inflammatory environment, Foxp3 gene silencing promoted hPDLFs migration but had no significant effect on hPDLFs proliferation. The expression of inflammatory factors expressed in hPDLFs increased after Foxp3 gene silencing, indicating that Foxp3 gene inhibited inflammation in periodontitis.

Overview of the main biological mechanisms linked to changes in periodontal ligament stem cells and the inflammatory microenvironment / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Periodontitis is a complex chronic inflammatory disease. The invasion of pathogens induces the inflammatory microenvironment in periodontitis. Cell behavior changes in response to changes in the microenvironment, which in turn alters the local inflammatory microenvironment of the periodontium through factors secreted by cells. It has been confirmed that periodontal ligament stem cells (PDLSCs) are vital in the development of periodontal disease. Moreover, PDLSCs are the most effective cell type to be used for periodontium regeneration. This review focuses on changes in PDLSCs, their basic biological behavior, osteogenic differentiation, and drug effects caused by the inflammatory microenvironment, to provide a better understanding of the influence of these factors on periodontal tissue homeostasis. In addition, we discuss the underlying mechanism in detail behind the reciprocal responses of PDLSCs that affect the microenvironment.

Concentración de mucina salival en pacientes con enfermedad periodontal / Concentração de mucina salivar em pacientes com doença periodontal / Salivary mucin concentration in patients with periodontal disease

Resumen El objetivo de este trabajo fue estudiar la relación entre la concentración de mucina salival y la enfermedad periodontal. La muestra se dividió en tres grupos de 20 individuos cada uno: Grupo 1 sin enfermedad periodontal; Grupo 2 con gingivitis; y Grupo 3 con periodontitis. En todas las muestras salivales se confirmó la presencia de mucina, el Grupo 1 presentó un valor promedio de 1,27 mg/ml. En el Grupo 2 se registró un promedio de 1,93 mg/ml. En el Grupo 3 se observó un promedio de 3,01 mg/ml. El Análisis de la Variancia y posterior prueba de F (F = 25,01, p < 0,0001) confirman diferencias significativas en los contenidos de mucina entre grupos. El aumento de la concentración de mucina salival en pacientes periodontales podría representar un marcador químico de utilidad como coadyuvante en el diagnóstico clínico de esta enfermedad.

Resumo O objetivo deste trabalho foi estudar a relação entre a concentração de mucina salivar e a doença periodontal. A amostra foi dividida em três grupos de 20 indivíduos cada: Grupo 1 sem doença periodontal; Grupo 2 com gengivite; e Grupo 3 com periodontite. Em todas as amostras salivares foi confirmada a presença de mucina, o Grupo 1 apresentou valor médio de 1,27 mg / ml. No Grupo 2, foi registrada uma média de 1,93 mg / ml. No Grupo 3 foi observada uma média de 3,01 mg / ml. A Análise de Variância e o teste F subsequente (F = 25,01, p <0,0001) confirmam diferenças significativas nos conteúdos de mucina entre os grupos. O aumento da concentração de mucina salivar em pacientes periodontais pode representar um marcador químico útil como adjuvante no diagnóstico clínico desta doença.

Abstract This work aimed to study the relationship between salivary mucin concentration and periodontal disease. The sample was divided into three groups of 20 individuals each: Group 1 with no periodontal disease, Group 2 with gingivitis, and Group 3 with periodontitis. Mucin was detected in all the saliva samples. Group 1 had an average value of 1.27 mg/ml. Group 2 had an average value of 1.93 mg/ml. Group 3 had an average value of 3.01 mg/ml. The analysis of variance and subsequent F test (F = 25.01, p < 0.0001) confirmed significant differences in mucin content between the groups. Increased salivary mucin concentration in periodontal patients could be a useful chemical marker for the clinical diagnosis of periodontal disease.

Signs of alveolar bone damage in early stages of periodontitis and its prevention by stimulation of cannabinoid receptor 2. Model in rats / Signos de daño óseo alveolar en estadios tempranos de periodontitis y su prevención por estimulación del receptor cannabinoide 2. Modelo en ratas microcisalhamento do cimento resinoso

ABSTRACT The aims of the present study were, first, to identify signs of alveolar bone damage in early stages of experimental periodontitis (EP) and, second, to assess its possible prevention by treatment with cannabinoid receptor 2 agonist HU 308. Experimental periodontitis was induced by injections of lipopolysaccharide (LPS) (1mg/ml) in gums surrounding maxillary and mandibular first molar, 3 days per week, and untreated controls were kept for comparison. Then, a 3-week study was conducted including eighteen new rats (six rats per group): 1) controls; 2) experimental periodontitis rats; and 3) experimental periodontitis rats treated daily with HU 308 (500 ng/ml). After euthanasia, alveolar bone loss was assessed by morphometric and histomorphometric techniques, and the content of prostaglandin E2 (PGE2) in gingival tissue was evaluated by radioimmunoassay. The first signs of alveolar bone loss were apparent at 3 weeks of experimental periodontitis (ρ<0.05) in the mandibular first molar, but there was no detectable change at 1 week, leading us to establish 3 weeks as an early stage of experimental periodontitis. Rats subjected to 3-week experimental periodontitis showed less interradicular bone volume, less whole bone perimeter and fewer bone formation areas, and higher periodontal space height, bone resorption areas, number of osteoclasts and gingival content of prostaglandin E2 than controls, while HU 308 prevented, at least partially, the deleterious effects (ρ<0.001). We can conclude that a 3-week term of lipopolysaccharide-induced periodontitis in rats provides a valid model of the early stage of the disease, as emerging damage is observed in bone tissue. Furthermore, harmful effects at 3 weeks could be prevented by local stimulation of cannabinoid receptor 2, before greater damage is produced.

RESUMEN El objetivo del presente trabajo fue, en primer lugar, identificar signos de daño óseo alveolar en estadios tempranos de periodontitis experimental y, en segundo lugar, evaluar su posible prevención mediante el tratamiento con el agonista del receptor cannabinoide 2, HU 308. La periodontitis experimental fue inducida por inyecciones de lipopolisacárido (1mg/ml) en la encía circundante al primer molar maxilar y mandibular, 3 días por semana, en tanto que controles no tratados fueron mantenidos para la comparación. Posteriormente, un estudio de 3 semanas con dieciocho nuevas ratas (seis por grupo) fue desarrollado: 1) controles; 2) ratas con periodontitis experimental, y 3) ratas con periodontitis experimental tratadas diariamente con HU 308 (500ng/ml). Luego de la euthanasia, la pérdida ósea alveolar fue evaluada por técnicas morfométricas e histomorfométricas, y el contenido de prostaglandina E2 en el tejido gingival fue determinado por radioinmunoensayo. Los primeros signos de pérdida ósea alveolar fueron evidentes a las 3 semanas de inducción de periodontitis experimental (ρ<0.05) en el primer molar mandibular, mientras que no hubo cambios detectables luego de 1 semana de inducción, hecho que nos condujo a establecer a las 3 semanas como un estadio temprano de periodontitis experimental, Las ratas sometidas a perdiodontitis experimental de 3 semanas mostraron menor volumen óseo interradicular, menor perímetro óseo y menos áreas de formación ósea, y mayor altura del espacio periodontal, más áreas de reabsorción ósea, mayor número de osteoclastos y mayor contenido gingival de prostaglandina E2, en comparación a los controles, mientras que el tratamiento con HU 308 previno, al menos parcialmente, los efectos deletéreos (ρ<0.001). Podemos concluir que el término de 3 semanas de periodontitis inducida por lipopolisacárido es un modelo válido de estadio inicial de la enfermedad experimental, dado que se evidencia daño emergente en el tejido óseo. Asimismo, los efectos deletéreos de 3 semanas podrían ser prevenidos por la estimulación local del receptor cannabinoide 2, antes que un daño mayor sea producido.

Upregulation of IL-10 expression inhibits the proliferation of human periodontal ligament stem cells

Abstract: The abnormal increase in proliferation rate of human periodontal ligament stem cells (PDLSCs) is considered to be involved in the pathogenesis of periodontitis, a disease in which the IL-10-mediated anti-inflammatory pathway plays a critical role. This study aimed to investigate the involvement of microRNA-466l in periodontitis and to explore the possible interaction between IL-10 and microRNA-466l. PDLSCs were obtained from periodontitis-affected teeth and healthy control teeth. The expression of microRNA-466l and IL-10 mRNA was measured in PDLSCs using RT-qPCR. The proliferation ability of PDLSCs was analyzed using CCK-8 assays. Overexpression of microRNA-466l in a PDLSC cell line was established using two different types of PDLSCs, and the effect of microRNA-466l overexpression on IL-10 expression and cell proliferation were detected by western blot and CCK-8 assays, respectively. We found that expression levels of microRNA-466l and IL-10 mRNA were significantly lower (P < 0.05) in PDLSCs derived from periodontitis-affected teeth compared to those derived from healthy teeth. However, the cell proliferation ability was significantly higher in the PDLSCs derived from periodontitis-affected teeth. Meanwhile microRNA-466l overexpression decreased cell proliferation rates of both types of PDLSCs and upregulated IL-10 expression. Together, these data suggest that microRNA-466l can upregulate IL-10 and reduce the proliferation rate of PDLSCs.

The role of visfatin levels in gingival crevicular fluid as a potential biomarker in the relationship between obesity and periodontal disease

Abstract Objectives Visfatin is an adipokine that plays an important role in immune functions as a growth factor, enzyme, and pro-inflammatory mediator. We aimed to determine the levels of visfatin, interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in gingival crevicular fluid (GCF) in both obese/non-obese patients, with/without generalized chronic periodontitis (GCP). Methodology Patients were categorized as obese (O) (n=31) or non-obese (nO) (n=19). Groups were divided into four subgroups according to periodontal conditions: (1) periodontally healthy without obesity (nO-Ctrl); (2) GCP without obesity (nO-CP); (3) periodontally healthy with obesity (O-Ctrl); and (4) GCP with obesity (O-CP). Demographic variables, anthropometric and laboratory data were recorded. Periodontal parameters were measured at baseline and 3rd months after either non-surgical periodontal treatment or calorie -restricted diet therapy. At the same time, GCF samples were taken from patients to analyze TNF-alpha, IL-6,and visfatin levels. Results Periodontal parameters were significantly higher in the O group than in the nO group (P<0.05). IL-6 levels were higher in the O group than in the nO group (P<0.001). The visfatin levels of the obese patients were reduceddecreased following the treatments (P<0.05). Cholesterol levels were higher in the O group than in the nO groups (P<0.05). IL-6 levels were higher in O-CP and O-Ctrl groups than in the nO-Ctrl group (P<0.05). Compared to the other groups, visfatin levels were significantly higher in the O-CP group but decreased following treatment (P<0.05). Conclusions Our findings suggest that visfatin and IL-6 levels in GCF are associated with the pathogenesis of obesity and periodontitis. Within the limits of this study, we considered that there might be an association between the lipid profile and periodontitis on systemically healthy individuals.

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.

Oxymatrine alleviates periodontitis in rats by inhibiting inflammatory factor secretion and regulating MMPs/TIMP protein expression

Abstract Purpose: To investigate the effect of oxymatrine on periodontitis in rats and related mechanism. Methods: Ninety SD rats were divided into control, model, 10, 20 and 40 mg/kg oxymatrine and tinidazole groups. The periodontitis model was established in later 5 groups. The 10, 20 and 40 mg/kg oxymatrine groups were intragastrically administrated with 10, 20 and 40 mg/kg oxymatrine, respectively. The tinidazole group was intragastrically administrated with 100 mg/kg tinidazole. The treatment duration was 4 weeks. The tooth mobility, gingival and plaque indexes, serum inflammatory factor levels and gingival tissue matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase (TIMP) protein levels were detected. Results: After treatment, compared with model group, in 40 mg/kg oxymatrine group the rat general conditions were obviously improved, the tooth mobility, gingival index and plaque index were significantly decreased (P<0.05), the serum tumor necrosis factor-α, interleukin-1β and prostaglandin E2 levels were significantly decreased (P<0.05), the MMP-2 and MMP-9 protein levels were significantly decreased (P<0.05), and the TIMP-2 protein level was significantly increased (P<0.05). Conclusions: Oxymatrine can alleviate the experimental periodontitis in rats. The mechanism may be related to its inhibiting inflammatory factor secretion and regulating MMPs/TIMP protein expression.

The role of potassium channels in the endothelial dysfunction induced by periodontitis

Abstract Objective: Periodontitis is associated with endothelial dysfunction, which is clinically characterized by a reduction in endothelium-dependent relaxation. However, we have previously shown that impairment in endothelium-dependent relaxation is transient. Therefore, we evaluated which mediators are involved in endothelium-dependent relaxation recovery. Material and methods: Rats were subjected to ligature-induced experimental periodontitis. Twenty-one days after the procedure, the animals were prepared for blood pressure recording, and the responses to acetylcholine or sodium nitroprusside were obtained before and 30 minutes after injection of a nitric oxide synthase inhibitor (L-NAME), cyclooxygenase inhibitor (Indomethacin, SC-550 and NS- 398), or calcium-dependent potassium channel blockers (apamin plus TRAM- 34). The maxilla and mandible were removed for bone loss analysis. Blood and gingivae were obtained for C-reactive protein (CRP) and myeloperoxidase (MPO) measurement, respectively. Results: Experimental periodontitis induces bone loss and an increase in the gingival MPO and plasmatic CRP. Periodontitis also reduced endothelium-dependent vasodilation, a hallmark of endothelial dysfunction, 14 days after the procedure. However, the response was restored at day 21. We found that endothelium-dependent vasodilation at day 21 in ligature animals was mediated, at least in part, by the activation of endothelial calcium-activated potassium channels. Conclusions: Periodontitis induces impairment in endothelial-dependent relaxation; this impairment recovers, even in the presence of periodontitis. The recovery is mediated by the activation of endothelial calcium-activated potassium channels in ligature animals. Although important for maintenance of vascular homeostasis, this effect could mask the lack of NO, which has other beneficial properties.

Cell Derived Microparticles in Gingival Crevicular Fluid from Periodontitis Patients with Type 2 Diabetes

Abstract Cell-derived microparticles (MPs) have been described as vital contributors to the inflammatory process. However, its role in the periodontal disease pathogenesis remains unclear. Therefore, we aimed to detect the presence neutrophil (CD66b+) and platelet (CD41b+) derived microparticles in gingival crevicular fluid from individuals having periodontitis aggravated by type 2 diabetes. Twelve patients (56.2 ±7.2 yrs) with severe form of chronic periodontitis aggravated by type 2 diabetes were included. Clinical and metabolic data were gathered. Gingival crevicular fluid was collected using filter strips from deep and shallow sites. MPs were detected by flow cytometry according to their size (< 1 µm) and the expression of surface markers (CD66b for neutrophil-derived MPs and CD41b for platelet-derived MPs). All samples were positive for the antibodies. Median levels of CD66b+ MPs and CD41b+ MPs were, respectively, 3,677.0 (2,553.2 - 9,059.8) MP/µL and 520.7 (432.9 - 766.1) MP/µL in deep sites. In shallow sites, the corresponding values were 2,644.9 (1,451.5 - 3,858.9) MP/µL and 371.2 (287.2 - 692.7) MP/µL. There was no significant difference between deep and shallow sites (p>0.05). In conclusion, this study reported the presence of neutrophil and platelet derived microparticles in gingival crevicular fluid from individuals having severe periodontitis and type 2 diabetes.

Resumo As micropartículas derivadas de células (MPs) têm sido descritas como contribuintes vitais para o processo inflamatório. No entanto, seu papel na patogênese da doença periodontal permanece obscuro. Por isso, nosso objetivo foi detectar a presença de micropartículas derivadas de neutrófilos (CD66b +) e plaquetas (CD41b +) no fluido gengival de indivíduos com periodontite e diabetes tipo 2. Doze pacientes (56,2 ± 7,2 anos) com periodontite crônica severa e diabetes tipo 2 foram incluídos no estudo. Foram coletados dados clínicos e metabólicos. O fluido gengival foi coletado usando tiras de filtro de papel em sítios rasos e profundos. As MPs foram detectadas por citometria de fluxo de acordo com o seu tamanho (<1 μm) e pela expressão de marcadores de superfície (CD66b para MPs derivadas de neutrófilos e CD41b para MPs derivadas de plaquetas). Todas as amostras foram positivas para os anticorpos. Os níveis médios de CD66b + MPs e CD41b + MPs foram, respectivamente, 3.677.0 (2,553.2 - 9,059.8) MP/μL e 520.7 (432.9 - 766.1) MP/μL nos sítios profundos. Nos sítios rasos, os valores correspondentes foram 2,644.9 (1,451.5 - 3,858.9) MP/μL e 371.2 (287.2 - 692.7) MP/μL. Não houve diferença significativa entre os sítios rasos e profundos (p>0.05). Concluindo, o presente estudo reportou a presença de micropartículas derivadas de neutrófilos e plaquetas no fluido gengival de pacientes com periodontite e com diabetes tipo 2 .

Periodontitis and type 2 diabetes among women with previous gestational diabetes: epidemiological and immunological aspects in a follow-up of three years

Abstract Periodontitis can contribute to the development of insulin resistance. Gestational diabetes is a risk factor for type 2 diabetes. Therefore, periodontitis, when associated with gestational diabetes, could increase the risk for the development of type 2 diabetes after pregnancy. Objective The aim of this study was to verify the incidence on the development of type 2 diabetes in women with previous gestational diabetes with and without periodontitis after a three-year time interval. Material and Methods Initial sample of this follow-up study consisted of 90 women diagnosed with gestational diabetes who underwent periodontal examination. After three years, 49 women were subjected to new periodontal examination and biological, behavioral, and social data of interest were collected. Additionally, the quantification of the C-reactive protein in blood samples was performed. Fasting glucose and glycated hemoglobin levels were requested. Saliva samples were collected for quantification of interleukin 6 and 10, tumor necrosis factor α, matrix metalloproteinase 2 and 9. Results The incidence of type 2 diabetes mellitus was 18.4% and of periodontitis was 10.2%. There was no significant difference in the incidence of type 2 diabetes mellitus among women with and without periodontitis. It was observed impact of C-reactive protein in the development of type 2 diabetes mellitus. However, it was not observed impact of periodontitis on the development of type 2 diabetes mellitus among women with previous gestational diabetes. Conclusions It was not observed impact of periodontitis on the development of type 2 diabetes among women with previous gestational diabetes. The impact of C-reactive protein in the development of type 2 diabetes mellitus highlights the importance of an inflammatory process in the diabetes pathogenesis.

Suppressor of cytokine signaling 1 expression during LPS-induced inflammation and bone loss in rats

Abstract This study aimed to characterize the dynamics of suppressor of cytokine signaling (SOCS1) expression in a rat model of lipopolysaccharide-induced periodontitis. Wistar rats in the experimental groups were injected three times/week with LPS from Escherichia coli on the palatal aspect of the first molars, and control animals were injected with vehicle (phosphate-buffered saline). Animals were sacrificed 7, 15, and 30 days after the first injection to analyze inflammation (stereometric analysis), bone loss (macroscopic analysis), gene expression (qRT-PCR), and protein expression/activation (Western blotting). The severity of inflammation and bone loss associated with LPS-induced periodontitis increased from day 7 to day 15, and it was sustained through day 30. Significant (p < 0.05) increases in SOCS1, RANKL, OPG, and IFN-γ gene expression were observed in the experimental group versus the control group at day 15. SOCS1 protein expression and STAT1 and NF-κB activation were increased throughout the 30-day experimental period. Gingival tissues affected by experimental periodontitis express SOCS1, indicating that this protein may potentially downregulate signaling events involved in inflammatory reactions and bone loss and thus may play a relevant role in the development and progression of periodontal disease.

Periodontitis and systemic lupus erythematosus / Doença periodontal e lúpus eritematoso sistêmico

ABSTRACT A large number of studies have shown a potential association between periodontal and autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus (SLE). Similar mechanisms of tissue destruction concerning periodontitis and other autoimmune diseases have stimulated the study of a possible relationship between these conditions. This study aims to review the literature about this potential association and their different pathogenic mechanisms. Considering that periodontal disease is a disease characterized by inflammation influenced by infectious factors, such as SLE, it is plausible to suggest that SLE would influence periodontal disease and vice-versa. However, this issue is not yet fully elucidated and several mechanisms have been proposed to explain this association, as deregulation mainly in innate immune system, with action of phagocytic cells and proinflammatory cytokines such as IL-1β and IL-18 in both conditions’ pathogenesis, leading to tissue destruction. However, studies assessing the relationship between these diseases are scarce, and more studies focused on common immunological mechanisms should be conducted to further understanding.

RESUMO Um grande número de estudos tem mostrado uma potencial associação entre doenças periodontais e doenças autoimunes, como artrite reumatoide e lúpus eritematoso sistêmico (LES). Os mecanismos de destruição tecidual semelhantes entre a periodontite e as demais doenças autoimunes têm estimulado o estudo de possíveis relações entre essas condições. O presente estudo tem como objetivo revisar a literatura acerca dessa potencial associação e dos seus diferentes mecanismos patogênicos. Considerando-se a doença periodontal uma doença de caráter inflamatório que sofre influência de fatores infecciosos, assim como o LES, é plausível sugerir que o LES influenciaria sua progressão, assim como a periodontite influenciaria a progressão do LES. Entretanto, essa questão ainda não é totalmente elucidada e vários mecanismos têm sido propostos para explicar tal associação, como desregulações, principalmente no sistema imune inato, com ações de células fagocíticas e de citocinas pró-inflamatórias, como IL-1β e IL-18, na patogênese de ambas as condições, o que contribui para a destruição tecidual. Existem, contudo, poucos estudos na literatura que avaliam a relação entre essas doenças e mais trabalhos focados nos mecanismos imunológicos comuns a ambas as condições devem ser feitos para um maior entendimento.

Antimicrobial peptides and nitric oxide production by neutrophils from periodontitis subjects

Neutrophils play an important role in periodontitis by producing nitric oxide (NO) and antimicrobial peptides, molecules with microbicidal activity via oxygen-dependent and -independent mechanisms, respectively. It is unknown whether variation in the production of antimicrobial peptides such as LL-37, human neutrophil peptides (HNP) 1-3, and NO by neutrophils influences the pathogenesis of periodontal diseases. We compared the production of these peptides and NO by lipopolysaccharide (LPS)-stimulated neutrophils isolated from healthy subjects and from patients with periodontitis. Peripheral blood neutrophils were cultured with or without Aggregatibacter actinomycetemcomitans-LPS (Aa-LPS), Porphyromonas gingivalis-LPS (Pg-LPS) and Escherichia coli-LPS (Ec-LPS). qRT-PCR was used to determine quantities of HNP 1-3 and LL-37 mRNA in neutrophils. Amounts of HNP 1-3 and LL-37 proteins in the cell culture supernatants were also determined by ELISA. In addition, NO levels in neutrophil culture supernatants were quantitated by the Griess reaction. Neutrophils from periodontitis patients cultured with Aa-LPS, Pg-LPS and Ec-LPS expressed higher HNP 1-3 mRNA than neutrophils from healthy subjects. LL-37 mRNA expression was higher in neutrophils from patients stimulated with Aa-LPS. Neutrophils from periodontitis patients produced significantly higher LL-37 protein levels than neutrophils from healthy subjects when stimulated with Pg-LPS and Ec-LPS, but no difference was observed in HNP 1-3 production. Neutrophils from periodontitis patients cultured or not with Pg-LPS and Ec-LPS produced significantly lower NO levels than neutrophils from healthy subjects. The significant differences in the production of LL-37 and NO between neutrophils from healthy and periodontitis subjects indicate that production of these molecules might influence individual susceptibility to important periodontal pathogens.

The presence of periodontopathogens associated with the tumour necrosis factor-alpha expression in patients with different periodontal status / Presencia de periodontopatogenos asociados con expresión de factor-alpha necrosis tumoral - en pacientes con diferente estado periodontal

El propósito de este trabajo fue fue investigar la relación entreP. gingivalis, T. forsythia, T. denticola, P.intermedia, y A. actinomycetemcomitanspresentes en surcos y/o bolsas de pacientes con gingivitis (G), periodontitis crónica leve (MiCP), periodontitis crónica moderada (MoCP) y periodontitis severa (PS) y la expresi¨®n de TNF-¦Á en tejido gingival segun el estado clínico periodontal. Para ello se seleccionaron seis pacientes con G, 7 con MiCP, 23 con MoCP y 7 con PS. Los patogenos extraidos de los surcos y/o bolsas se identificaron mediante PCR con cebadores especificos para cada especie, Se detectó la expresión de TNF-¦Á en tejido gingival. Se registraron los siguientes parametros clinicos: profundidad al sondaje (PD), perdida de inserción clónica (CAL) y perdida de hueso. Se detectó P. gingivalis con la siguiente frecuencia: 16,6 por ciento en sujetos con G, 57,1 por ciento en MiCP, 57.8 por ciento en MoCP y 58.1 por ciento en PS (p < 0,05). P. intermedia no fue detectada en pacientes con G y A. actinomycetemcomitans fue solamenteidentificado en MoCP (31,5 por ciento) y PS (42.8 por ciento) T denticola y T. forsythia se identificaron en todos los grupos. Las combinaciones bacterianas P. denticola + P. intermedia y P. intermedia + T. forsythia se identificaron asociadas significativamente (p = 0,04, p =0,02) con la presencia de mRNA TNF-¦Á en 20 por ciento y 25 por ciento de los sujetos, respectivamente. P. gingivalis + A. actinomycetemcomitans y A. actinomycetemcomitans + T. forsythia se asociaron con valores de PD y CAL de gravedad. La asociación entre la presencia de P. intermedia y los niveles de expresi¨®n de TNF-¦Á fue significativa(p = 0,05). Estos resultados indican que la proporción de pacientes con P. gingivalis aumenta con la progresión de la enfermedad. Observamos que la presencia de P.intermedia desencadenaria la expresión de TNF-¦Á y provocaria un empeoramiento del estado clinico del paciente.

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.

In vitro studies on inhibitory effect of proanthocyanidins in modulation of neutrophils and macrophages.

The role of proanthocyanidins (PC), a novel flavonoid extracted from grape seeds was studied in vitro in the modulation of neutrophil and macrophage function. We attempted to assess the levels of non-enzymatic and enzymatic mediators in the presence or absence of PC in 4-phorbol-12--myristate-13-acetate (PMA)-stimulated neutrophils isolated from humans and rats, E. coli endotoxin-stimulated macrophages and macrophages isolated from E. coli endotoxin-induced experimental periodontitis in rats. Addition of PC at a concentration of 50 µg/ml effectively blocked the release of reactive oxygen species (ROS) and reactive nitrogen species (RNS) and exhibited a marked inhibition of myeloperoxidase (MPO) and lysosomal enzymes (p<0.001), as compared to PMA-stimulated neutrophils (human and rats) and neutrophils isolated from experimental periodontitis in rats. The levels of ROS, RNS and lysosomal enzymes were found to be elevated (p<0.001) and addition of PC significantly (p<0.001) reduced these levels as compared to those from E. coli endotoxin-stimulatedmacrophages from rats and macrophages isolated from experimental periodontitis in rats (p<0.001). Thus, the study demonstrated that PC decreased the levels of ROS and RNS and also inhibited the MPO and lysosomal enzymes activities in experimental periodontitis in rats. In addition, this study clearly indicated that PC could be developed as an effective antiinflammatory agent.

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.

Determination of systemically & locally induced periodontal defects in rats.

BACKGROUND & OBJECTIVE: The role of lathyrogens on bone metabolism is unclear, therefore we undertook this study to observe periodontal and systemic alterations in experimental lathyrism in rat and compare these changes to that observed in the locally induced periodontitis group. METHODS: A total of 45 male Wistar rats were equally divided in the lathyritic group (group 1), ligature-induced periodontitis group (group 2), and healthy controls (group 3). Experimental lathyrism was induced by once daily subcutaneous administration of beta-aminoproprionitrile (beta-APN), at a dose of 5 mg/0.4 ml per 100 g of body weight for 40 days. Ligature-induced periodontitis was created by tying silk ligatures on the necks of mandibular molars. After 40 days, blood samples were obtained and the animals were decapitated. Radiographic observations, extraction tests, histologic evaluations were performed, and serum ALP activity and gingival tissue IL-1beta levels were measured. RESULTS: Significant alveolar bone resorption around the mandibular molar teeth (P<0.001); lower extraction force levels (P<0.001); higher numbers of lymphocytes and macrophages (P<0.01) (both in connective tissue and epithelium at the dentogingival junction); decreased ALP activity (P<0.001); and increased gingival tissue IL-1beta levels (P<0.001) were observed in groups 1 and 2, compared to those in group 3. ALP activity was higher in group 1 than in group 2 rats (P<0.05). INTERPRETATION & CONCLUSION: Similar radiographical and histopathological findings and comparable increases in gingival tissue IL-1beta levels both in groups 1 and 2 showed that in addition to resorption of alveolar bone, chronic inflammation of periodontium also occurred both in the lathyritic rats as well as in ligature-induced periodontitis group rats.