RESUMO
Periodontal and periapical lesions are infectious inflammatory osteolitytic conditions in which a complex inflammatory immune response mediates bone destruction. However, the uncertainty of a lesion's progressive or stable phenotype complicates understanding of the cellular and molecular mechanisms triggering lesion activity. Evidence from clinical and preclinical studies of both periodontal and periapical lesions points to a high receptor activator of NF-κB ligand/osteoprotegerin (RANKL/OPG) ratio as the primary determinant of osteolytic activity, while a low RANKL/OPG ratio is often observed in inactive lesions. Proinflammatory cytokines directly modulate RANKL/OPG expression and consequently drive lesion progression, along with pro-osteoclastogenic support provided by Th1, Th17, and B cells. Conversely, the cooperative action between Th2 and Tregs subsets creates an anti-inflammatory and proreparative milieu associated with lesion stability. Interestingly, the trigger for lesion status switch from active to inactive can originate from an unanticipated RANKL immunoregulatory feedback, involving the induction of Tregs and a host response outcome with immunological tolerance features. In this context, dendritic cells (DCs) appear as potential determinants of host response switch, since RANKL imprint a tolerogenic phenotype in DCs, described to be involved in both Tregs and immunological tolerance generation. The tolerance state systemically and locally suppresses the development of exacerbated and pathogenic responses and contributes to lesions stability. However, immunological tolerance break by comorbidities or dysbiosis could explain lesions relapse toward activity. Therefore, this article will provide a critical review of the current knowledge concerning periodontal and periapical lesions activity and the underlying molecular mechanisms associated with the host response. Further studies are required to unravel the role of immunological responsiveness or tolerance in the determination of lesion status, as well as the potential cooperative and/or inhibitory interplay among effector cells and their impact on RANKL/OPG balance and lesion outcome.
Assuntos
Osteoprotegerina , Ligante RANK , Doença Crônica , Citocinas , Humanos , Células Th17RESUMO
Short-chain fatty acids (SCFAs) exert a variety of immune and metabolic functions by binding to G-protein-coupled receptors, mainly free fatty acid receptor 2 (FFAR2). However, the effects of SCFAs and FFARs on bone remodeling, especially in alveolar bone, have been less explored. In this study, we investigated the influence of the SCFA/FFAR2 axis on alveolar bone. Bone samples from wild-type (WT) and FFAR2-deficient mice (FFAR2-/-) were analyzed using micro-CT, histology and qPCR. WT and FFAR2-/- animals received a high-fiber diet (HFD) reported to increase circulating levels of SCFAs. Additionally, we analyzed the effects of SCFAs and a synthetic FFAR2 agonist, phenylacetamide-1 (CTMB), on bone cell differentiation. The participation of histone deacetylase inhibitors (iHDACs) in the effects of SCFAs was further assessed in vitro. CTMB treatment was also evaluated in vivo during orthodontic tooth movement (OTM). FFAR2-/- mice exhibited deterioration of maxillary bone parameters. Consistent with this, FFAR2-/- mice exhibited a significant increase of OTM and changes in bone cell numbers and in the expression of remodeling markers. The HFD partially reversed bone loss in the maxillae of FFAR2-/- mice. In WT mice, the HFD induced changes in the bone markers apparently favoring a bone formation scenario. In vitro, bone marrow cells from FFAR2-/- mice exhibited increased differentiation into osteoclasts, while no changes in osteoblasts were observed. In line with this, differentiation of osteoclasts was diminished by SCFAs and CTMB. Moreover, CTMB treatment significantly reduced OTM. Pretreatment of osteoclasts with iHDACs did not modify the effects of SCFAs on these cells. In conclusion, SCFAs function as regulators of bone resorption. The effects of SCFAs on osteoclasts are dependent on FFAR2 activation and are independent of the inhibition of HDACs. FFAR2 agonists may be useful to control bone osteolysis.
Assuntos
Ácidos Graxos Voláteis/farmacologia , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Animais , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Reabsorção Óssea/tratamento farmacológico , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Receptores Acoplados a Proteínas G/genética , Microtomografia por Raio-XRESUMO
AIM: To investigate the DNA methylation profiles of immune response-related genes in apical periodontitis (AP) lesions. METHODOLOGY: The methylation profiles on the cytosine-phosphate-guanine (CpG) regions of 22 gene promoters involved in inflammation and autoimmunity were assessed in 60 human AP lesions and 24 healthy periodontal ligaments (controls) using a pathway-specific real-time polymerase chain reaction array (EpiTect® Methyl Signature PCR Array Human Inflammatory Response). Differentially methylated genes were subsequently assessed for their mRNA expression. Data analyses (One-way anova, Tukey's multiple comparisons tests and Mann-Whitney tests) were performed using GraphPad Prism 6 software. P values ≤ 0.05 were considered statistically significant. RESULTS: Significant DNA hypermethylation was observed for CXCL3 and FADD gene promoters in AP lesions when compared to control tissues (P < 0.001) and among other genes (P < 0.05). In contrast, IL12B and IL4R were associated with significant hypomethylation in comparison to other genes (P < 0.05). IL12B, IL4R, CXCL3 and FADD had differential mRNA expression in AP lesions and controls (P < 0.001). CONCLUSIONS: Differential methylation profiles of immune response-related genes, such as FADD, CXCL3, IL12B and IL4R, may have an influence on individual AP susceptibility and patient treatment outcomes, through their potential contributions to altered expression of disease-relevant genes. Methylation and/or genetic variations in additional genes may also contribute to the dynamics of AP development and should be considered in future studies.
Assuntos
Metilação de DNA , Periodontite Periapical/genética , Periodontite Periapical/imunologia , Periodontite Periapical/metabolismo , Transcriptoma , Adolescente , Adulto , Idoso , Autoimunidade/genética , Brasil , Quimiocinas/genética , Quimiocinas CXC/genética , Citocinas/genética , Proteína de Domínio de Morte Associada a Fas/genética , Regulação da Expressão Gênica , Humanos , Inflamação , Subunidade p40 da Interleucina-12/genética , Subunidade alfa de Receptor de Interleucina-4/genética , Pessoa de Meia-Idade , Ligamento Periodontal , Regiões Promotoras Genéticas , RNA Mensageiro/biossíntese , Reação em Cadeia da Polimerase em Tempo Real , Receptores de Citocinas/genética , Adulto JovemRESUMO
The chronic inflammatory immune response triggered by the infection of the tooth root canal system results in the local upregulation of RANKL, resulting in periapical bone loss. While RANKL has a well-characterized role in the control of bone homeostasis/pathology, it can play important roles in the regulation of the immune system, although its possible immunoregulatory role in infectious inflammatory osteolytic conditions remains largely unknown. Here, we used a mouse model of infectious inflammatory periapical lesions subjected to continuous or transitory anti-RANKL inhibition, followed by the analysis of lesion outcome and multiple host response parameters. Anti-RANKL administration resulted in arrest of bone loss but interfered in the natural immunoregulation of the lesions observed in the untreated group. RANKL inhibition resulted in an unremitting proinflammatory response, persistent high proinflammatory and effector CD4 response, decreased regulatory T-cell (Treg) migration, and lower levels of Treg-related cytokines IL-10 and TGFb. Anti-RANKL blockade impaired the immunoregulatory process only in early disease stages, while the late administration of anti-RANKL did not interfere with the stablished immunoregulation. The impaired immunoregulation due to RANKL inhibition is characterized by increased delayed-type hypersensitivity in vivo and T-cell proliferation in vitro to the infecting bacteria, which mimic the effects of Treg inhibition, reinforcing a possible influence of RANKL on Treg-mediated suppressive response. The adoptive transfer of CD4+FOXp3+ Tregs to mice receiving anti-RANKL therapy restored the immunoregulatory capacity, attenuating the inflammatory response in the lesions, reestablishing normal T-cell response in vivo and in vitro, and preventing lesion relapse upon anti-RANKL therapy cessation. Therefore, while RANKL inhibition efficiently limited the periapical bone loss, it promoted an unremitting host inflammatory response by interfering with Treg activity, suggesting that this classic osteoclastogenic mediator plays a role in immunoregulation.
Assuntos
Osteólise/imunologia , Doenças Periapicais/imunologia , Ligante RANK/imunologia , Linfócitos T Reguladores/imunologia , Transferência Adotiva , Perda do Osso Alveolar/imunologia , Perda do Osso Alveolar/microbiologia , Animais , Anticorpos Monoclonais/farmacologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Expressão Gênica , Imunidade nas Mucosas , Inflamação/imunologia , Inflamação/microbiologia , Infliximab/farmacologia , Interleucina-10/imunologia , Ativação Linfocitária/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Osteólise/microbiologia , Doenças Periapicais/microbiologia , Ligante RANK/antagonistas & inibidores , Reação em Cadeia da Polimerase em Tempo Real , Fator de Crescimento Transformador beta/imunologiaRESUMO
OBJECTIVES: The aim of this study was to analyze MMP-1 transcript levels in periodontal tissues of rats that underwent orthodontic treatment using potassium diclofenac and dexamethasone at different stages of tooth movement. SETTING AND SAMPLE POPULATION: The sample comprised of ninety male Wistar rats. MATERIAL AND METHODS: A closed nickel-titanium coil spring was used to apply a force of 50 cN to move the maxillary right first molars mesially. One group received daily doses of 0.9% saline solution, the second group received daily doses of 5 mg/kg potassium diclofenac, and the third group received daily doses of 0.5 mg/kg dexamethasone. Tooth movement was observed on days 0, 1, 3, 7, and 14. MMP-1 transcript levels were evaluated by real-time polymerase chain reaction and the results were compared between groups by three-way ANOVA, with a significance level of 0.05. RESULTS: Transcript levels increased in groups that received the coil spring treatment on all days of the experiment. MMP-1 expression was found to be decreased in groups treated with potassium diclofenac and dexamethasone compared to that in the control group, on days 1, 3, 5, and 7. CONCLUSIONS: The application of orthodontic forces significantly increased MMP-1 transcript levels. The use of anti-inflammatory drugs may have an inhibitory effect on MMP-1 expression.
Assuntos
Anti-Inflamatórios/farmacologia , Dexametasona/farmacologia , Diclofenaco/farmacologia , Metaloproteinase 1 da Matriz/efeitos dos fármacos , Técnicas de Movimentação Dentária , Animais , Masculino , Metaloproteinase 1 da Matriz/metabolismo , Periodonto/efeitos dos fármacos , Periodonto/metabolismo , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/metabolismo , Ratos WistarRESUMO
Estrogen deficiency results in disruption of maxillary alveolar bone microarchitecture. Most of the actions of estrogen in long bones occur via estrogen receptor α (ERα). However, the function of ERα in the maxillary bone has not been defined. We aimed to investigate the role and underlying mechanisms of ERα in the physiological and mechanically induced alveolar bone remodeling in female and male mice. Wild-type (WT) and ERα(-/-) (ERKOα) mice were subjected to mechanically stimulated bone remodeling by inducing orthodontic tooth movement (OTM). The maxillary bone was analyzed using histomorphometric analysis, micro-computed tomography, quantitative polymerase chain reaction, and energy-dispersive spectroscopy. Bone marrow cells (BMCs) from WT and ERKOα mice were tested for their capacity to differentiate into osteoblasts and osteoclasts. Both male and female ERKOα mice exhibited marked reduction of alveolar bone mass and increased OTM. This response was associated with an increased number of osteoclasts and reduced number of apoptotic cells and osteoblasts in the periodontium and alveolar bone. Consistently, ERKOα mice exhibited lower levels of calcium in bone and increased expression of IL-33 (interleukin-33), TNF-α (tumor necrosis factor α), and IL-1ß (interleukin-1ß) and decreased expression of dentin matrix acidic phosphoprotein and alkaline phosphatase in periodontal tissues. Moreover, the differentiation of osteoclasts and osteoblasts in vitro was significantly higher in BMCs obtained from ERKOα. ERα is required to maintain the microarchitecture of maxillary alveolar bone. This process is linked to bone cell differentiation and apoptosis, as well as local production of inflammatory molecules such as IL-33, TNF-α, and IL-1ß.
Assuntos
Perda do Osso Alveolar/prevenção & controle , Receptor alfa de Estrogênio/fisiologia , Maxila/fisiologia , Fosfatase Alcalina/metabolismo , Animais , Apoptose , Células da Medula Óssea/fisiologia , Remodelação Óssea , Cálcio/metabolismo , Diferenciação Celular , Proteínas da Matriz Extracelular/metabolismo , Feminino , Interleucina-1beta/metabolismo , Interleucina-33/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Osteoblastos/metabolismo , Osteoclastos/metabolismo , Ovariectomia , Fenótipo , Reação em Cadeia da Polimerase , Transdução de Sinais , Espectrometria por Raios X , Técnicas de Movimentação Dentária , Fator de Necrose Tumoral alfa/metabolismo , Microtomografia por Raio-XRESUMO
5-Lipoxygenase (5-LO) metabolites are important pro-inflammatory lipid mediators. However, much still remains to be understood about the role of such mediators in bone remodeling. This study aimed to investigate the effect of 5-LO metabolites, LTB4 and CysLTs, in a model of mechanical loading-induced bone remodeling. Strain-induced tooth movement and consequently alveolar bone resorption/apposition was achieved by using a coil spring placed on molar and attached to incisors of C57BL6 (wild-type-WT), 5-LO deficient mice (5-LO(-/-)) and mice treated with 5-LO inhibitor (zileuton-ZN) or with antagonist of CysLTs receptor (montelukast-MT). The amount of bone resorption and the number of osteoclasts were determined morphometrically. The expression of inflammatory and bone remodeling markers in periodontium was analyzed by qPCR. Osteoclast differentiation and TNF-α production were evaluated in vitro using RAW 264.7 cells treated with LTB4 or LTD4. Bone resorption, TRAP(+) cells and expression of Tnfa, Il10 and Runx2 were significantly diminished in 5-LO(-/-), ZN- and MT-treated mice. The expression of Rank was also reduced in 5-LO(-/-) and MT-treated mice. Accordingly, LTB4 and LTD4 in association with RANKL promoted osteoclast differentiation and increased TNF-α release in vitro. These data demonstrate that the absence of 5-LO metabolites, LTB4 and CysLTs reduces osteoclast recruitment and differentiation, consequently diminishing bone resorption induced by mechanical loading. Thus, 5-LO might be a potential target for controlling bone resorption in physiological and pathological conditions.
Assuntos
Araquidonato 5-Lipoxigenase/metabolismo , Reabsorção Óssea/metabolismo , Leucotrienos/metabolismo , Osteoclastos/metabolismo , Animais , Diferenciação Celular/fisiologia , Linhagem Celular , Ensaio de Imunoadsorção Enzimática , Leucotrieno B4/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Osteoclastos/citologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estresse MecânicoRESUMO
The disruption of host-microbe homeostasis at the site of periodontal disease is considered a key factor for disease initiation and progress. While the downstream mechanisms responsible for the tissue damage per se are relatively well-known (involving various patterns of immune response operating toward periodontal tissue destruction), we are only beginning to understand the complexity of host-microbe interactions in the periodontal environment. Unfortunately, most of the research has been focused on the disruption of host-microbe homeostasis instead of focusing on the factors responsible for maintaining homeostasis. In this context, regulatory T-cells (Tregs) comprise a CD4+FOXp3 +T-cell subset with a unique ability to regulate other leukocyte functions to avoid excessive immune activation and its pathological consequences. Tregs act as critical determinants of host-microbe homeostasis, as well as determinants of a balanced host response after the disruption of host-microbe homeostasis by pathogens. In periodontitis, Tregs play a protective role, with their natural recruitment being responsible for conversion of active into inactive lesions. With controlled-release technology, it is now possible to achieve a selective chemoattraction of Tregs to periodontal tissues, attenuating experimental periodontitis evolution due to the local control of inflammatory immune response and the generation of a pro-reparative environment.
Assuntos
Quimiotaxia de Leucócito/imunologia , Homeostase/imunologia , Interações Hospedeiro-Patógeno/imunologia , Periodontite/microbiologia , Linfócitos T Reguladores/imunologia , Linfócitos T CD4-Positivos/imunologia , Fatores de Transcrição Forkhead/imunologia , Humanos , Imunidade nas Mucosas/imunologia , Periodontite/imunologia , Cicatrização/imunologiaRESUMO
We have identified impaired neutrophils in elderly individuals which could be involved with Candida-related denture stomatitis (DS), an oral infection predominantly caused by Candida albicans, affecting especially elderly individuals using dental prosthesis. However, specific mechanisms performed by neutrophil contributing to the susceptibility of the elderly to DS are not fully understood. This study evaluated activation features of blood neutrophils from elderly and young individuals with DS. Blood neutrophils cultured with C. albicans from elderly subjects secreted decreased levels of CXCL8. However, C. albicans challenged-neutrophils from DS patients produced high IL-4 and IL-10, and low GM-CSF levels, regardless of age. Additional elastase activity of neutrophils from both elderly groups was detected after incubation with C. albicans, but only neutrophils from elderly DS demonstrated high myeloperoxidase activity. Therefore, DS patients have affected neutrophils, and the advance of age intensifies these damages. In summary, individuals with Candida-related denture stomatitis presented variation in the neutrophil phenotype and activation. Such alterations were more intense in neutrophils from infected elderly individuals.
Assuntos
Sangue/imunologia , Candida albicans/imunologia , Candidíase Bucal/imunologia , Ativação de Neutrófilo , Estomatite sob Prótese/imunologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Candida albicans/patogenicidade , Células Cultivadas , Citocinas/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Elastase Pancreática/metabolismo , Peroxidase/metabolismoRESUMO
Periodontal disease (PD) progression involves the selective leukocyte infiltration into periodontium, supposedly mediated by the chemokine/chemokine receptor system. In this study, we investigated the role of chemokine receptor CCR5 in the immunoregulation of experimental PD in C57BL/6 (WT) and CCR5KO mice. Aggregatibacter actinomycetem comitans infection triggered the chemoattraction of distinct CCR5+ leukocyte subpopulations (determined by flow cytometry): CCR5+F4/80+ leukocytes, which co-express CD14 , CCR2, TNF-α, and IL-1ß, indicative of activated macrophages; and CCR5+CD4+ cells, which co-express CXCR3, IFN-γ, and RANKL, indicative of Th1 lymphocytes, therefore comprising pro-osteoclastic and osteoclastogenic cell subsets, respectively. CCR5KO mice presented a lower PD severity (lower inflammation and alveolar bone loss) when compared with the WT strain, since the migration of F4/80+, TNF-α+, CD4+, and RANKL+ cells specifically decreased due to the lack of CCR5. Also, ELISA analysis demonstrated that the production of TNF-α, IL-1ß, IL-6, IFN-γ, and RANKL in periodontal tissues was significantly decreased in the CCR5KO strain. The periodontal bacterial load and antimicrobial patterns were unaltered in CCR5KO mice. Our results demonstrate that the chemokine receptor is involved in the migration of distinct leukocyte subpopulations throughout experimental PD, being a potential target for therapeutic intervention in PD.
Assuntos
Perda do Osso Alveolar/imunologia , Quimiotaxia de Leucócito/imunologia , Periodontite Crônica/imunologia , Osteoclastos/imunologia , Receptores CCR5/imunologia , Aggregatibacter actinomycetemcomitans/fisiologia , Perda do Osso Alveolar/metabolismo , Animais , Carga Bacteriana , Periodontite Crônica/metabolismo , Citocinas/biossíntese , Interferon gama/biossíntese , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ligante RANK/biossíntese , Receptores CCR5/biossíntese , Células Th1/imunologiaRESUMO
Periodontal diseases (PD) are chronic infectious inflammatory diseases characterized by the destruction of tooth-supporting structures, being the presence of periodontopathogens required, but not sufficient, for disease development. As a general rule, host inflammatory mediators have been associated with tissue destruction, while anti-inflammatory mediators counteract and attenuate disease progression. With the discovery of several T-cell subsets bearing distinct immunoregulatory properties, this pro- vs. anti-inflammatory scenario became more complex, and a series of studies has hypothesized protective or destructive roles for Th1, Th2, Th17, and Treg subpopulations of polarized lymphocytes. Interestingly, the "protective vs. destructive" archetype is usually considered in a framework related to tissue destruction and disease progression. However, it is important to remember that periodontal diseases are infectious inflammatory conditions, and recent studies have demonstrated that cytokines (TNF-α and IFN-γ) considered harmful in the context of tissue destruction play important roles in the control of periodontal infection. Therefore, in this review, the state-of-the-art knowledge concerning the protective and destructive roles of host inflammatory immune response will be critically evaluated and discussed from the tissue destruction and control-of-infection viewpoints.
Assuntos
Citocinas/imunologia , Periodontite/imunologia , Imunidade Adaptativa/imunologia , Progressão da Doença , Humanos , Imunidade Inata/imunologia , Mediadores da Inflamação/imunologia , Interferon gama/imunologia , Periodontite/microbiologia , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Reguladores/imunologia , Fator de Necrose Tumoral alfa/imunologiaRESUMO
Periodontitis (PD) and rheumatoid arthritis (RA) have been found to be clinically associated and to share the chronic nature of the inflammatory reaction associated with bone resorption activity. However, the mechanisms underlying such association are unknown. Therefore, we examined the basis of Actinobacillus actinomycetemcomitans- and Porphyromonas gingivalis-induced PD and pristane-induced arthritis (PIA) interaction in mice. Higher severity PD in the genetically inflammation prone acute inflammatory reactivity maximum (AIRmax) mice strain was associated with higher levels of TNF-alpha, IL-1beta, IL-17, matrix metalloproteinase (MMP)-13, and RANKL, whereas PD/PIA co-induction resulted in even higher levels of IL-1beta, IFN-gamma, IL-17, RANKL, and MMP-13 levels. Conversely, PD/PIA co-induction in AIRmin strain did not alter the course of both pathologies. PIA/PD co-induction resulted in altered expression of T-cell subsets transcription factors expression, with T-bet and RORgamma levels being upregulated, whereas GATA-3 levels were unaltered. Interestingly, PIA induction resulted in alveolar bone loss, such response being highly dependent on the presence of commensal oral bacteria. No differences were found in PIA severity parameters by PD co-induction. Our results show that the interaction between experimental PD and arthritis in mice involves a shared hyper-inflammatory genotype and functional interferences in innate and adaptive immune responses.
Assuntos
Artrite Reumatoide/genética , Artrite Reumatoide/imunologia , Genótipo , Mediadores da Inflamação/fisiologia , Periodontite/genética , Periodontite/imunologia , Animais , Artrite Reumatoide/patologia , Inflamação/genética , Inflamação/imunologia , Inflamação/patologia , Mediadores da Inflamação/metabolismo , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/patologia , Camundongos , Camundongos Transgênicos , Periodontite/patologiaRESUMO
Periodontitis (PD) and rheumatoid arthritis (RA) have been found to be clinically associated and to share the chronic nature of the inflammatory reaction associated with bone resorption activity. However, the mechanisms underlying such association areunknown. Therefore, we examined the basis of Actinobacillus actinomycetemcomitans- and Porphyromonas gingivalis-inducedPD and pristane-induced arthritis (PIA) interaction in mice. Higher severity PD in the genetically inflammation prone acute inflammatory reactivity maximum (AIRmax) mice strain was associated with higher levels of TNF-a, IL-1b, IL-17, matrix metalloproteinase (MMP)-13, and RANKL, whereas PD/PIA co-induction resulted in even higher levels of IL-1b, IFN-g, IL-17, RANKL, and MMP-13 levels. Conversely, PD/PIA co-induction in AIRmin strain did not alter the course of both pathologies. PIA/PD co-induction resulted in altered expression of T-cell subsets transcription factors expression, with T-bet and RORg levels being upregulated, whereas GATA-3 levels were unaltered. Interestingly, PIA induction resulted in alveolar bone loss, such response being highly dependent on the presence of commensal oral bacteria. No differences were found in PIA severity parameters by PD co-induction. Our results show that the interaction between experimental PD and arthritis in mice involves a shared hyper-inflammatory genotype and functional interferences in innate and adaptive immune responses.
Assuntos
Animais , Ratos , Artrite Reumatoide , Doenças Periodontais , Doenças Periodontais/genética , Doenças Periodontais/imunologia , Inflamação , Aggregatibacter actinomycetemcomitans , Citocinas , Porphyromonas gingivalisRESUMO
During orthodontic tooth movement, there is local production of chemokines and an influx of leukocytes into the periodontium. CCL5 plays an important role in osteoclast recruitment and activation. This study aimed to investigate whether the CCR5-receptor influences these events and, consequently, orthodontic tooth movement. An orthodontic appliance was placed in wild-type mice (WT) and CCR5-deficient mice (CCR5(-/-)). The expression of mediators involved in bone remodeling was evaluated in periodontal tissues by Real-time PCR. The number of TRAP-positive osteoclasts and the expression of cathepsin K, RANKL, and MMP13 were significantly higher in CCR5(-/-). Meanwhile, the expression of two osteoblastic differentiation markers, RUNX2 and osteocalcin, and that of bone resorption regulators, IL-10 and OPG, were lower in CCR5(-/-). Analysis of the data also showed that CCR5(-/-) exhibited a greater amount of tooth movement after 7 days of mechanical loading. The results suggested that CCR5 might be a down-regulator of alveolar bone resorption during orthodontic movement.
Assuntos
Regulação para Baixo/fisiologia , Osteoclastos/fisiologia , Receptores CCR5/fisiologia , Técnicas de Movimentação Dentária , Fosfatase Ácida/análise , Animais , Biomarcadores/análise , Remodelação Óssea/fisiologia , Reabsorção Óssea/fisiopatologia , Catepsina K , Catepsinas/análise , Movimento Celular/fisiologia , Quimiocina CCL2/análise , Quimiocina CCL3/análise , Quimiocina CCL5/análise , Subunidade alfa 1 de Fator de Ligação ao Core/análise , Cisteína Endopeptidases/análise , Citocinas/análise , Interleucina-10/análise , Isoenzimas/análise , Metaloproteinase 13 da Matriz/análise , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Osteocalcina/análise , Osteoprotegerina/análise , Ligante RANK/análise , Estresse Mecânico , Fosfatase Ácida Resistente a TartaratoRESUMO
INTRODUCTION: Periodontal disease is a chronic inflammation of the attachment structures of the teeth, triggered by potentially hazardous microorganisms and the consequent immune-inflammatory responses. In humans, the T helper type 17 (Th17) lineage, characterized by interleukin-17 (IL-17) production, develops under transforming growth factor-beta (TGF-beta), IL-1beta, and IL-6 signaling, while its pool is maintained by IL-23. Although this subset of cells has been implicated in various autoimmune, inflammatory, and bone-destructive conditions, the exact role of T lymphocytes in chronic periodontitis is still controversial. Therefore, in this study we investigated the presence of Th17 cells in human periodontal disease. METHODS: Gingival and alveolar bone samples from healthy patients and patients with chronic periodontitis were collected and used for the subsequent assays. The messenger RNA expression for the cytokines IL-17, TGF-beta, IL-1beta, IL-6, and IL-23 in gingiva or IL-17 and receptor activator for nuclear factor-kappaB ligand in alveolar bone was evaluated by real-time polymerase chain reaction. The production of IL-17, TGF-beta, IL-1beta, IL-6, and IL-23 proteins was evaluated by immunohistochemistry and the presence of Th17 cells in the inflamed gingiva was confirmed by immunofluorescence confocal microscopy for CD4 and IL-17 colocalization. RESULTS: Our data demonstrated elevated levels of IL-17, TGF-beta, IL-1beta, IL-6, and IL-23 messenger RNA and protein in diseased tissues as well as the presence of Th17 cells in gingiva from patients with periodontitis. Moreover, IL-17 and the bone resorption factor RANKL were abundantly expressed in the alveolar bone of diseased patients, in contrast to low detection in controls. CONCLUSION: These results provided strong evidence for the presence of Th17 cells in the sites of chronic inflammation in human periodontal disease.
Assuntos
Perda do Osso Alveolar/imunologia , Periodontite Crônica/imunologia , Interleucina-17/biossíntese , Linfócitos T Auxiliares-Indutores/imunologia , Adulto , Perda do Osso Alveolar/metabolismo , Estudos de Casos e Controles , Feminino , Imunofluorescência , Expressão Gênica , Humanos , Imuno-Histoquímica , Interleucina-1beta/biossíntese , Interleucina-23/biossíntese , Interleucina-6/biossíntese , Masculino , Microscopia Confocal , Ligante RANK/biossíntese , RNA Mensageiro/biossíntese , Linfócitos T Auxiliares-Indutores/metabolismo , Fator de Crescimento Transformador beta/biossínteseRESUMO
INTRODUCTION: Periapical chronic lesion formation involves activation of the immune response and alveolar bone resorption around the tooth apex. However, the overall roles of T helper type 1 (Th1), Th2, and T-regulatory cell (Treg) responses and osteoclast regulatory factors in periapical cysts and granulomas have not been fully determined. This study aimed to investigate whether different forms of apical periodontitis, namely cysts and granulomas, show different balances of Th1, Th2 regulators, Treg markers, and factors involved in osteoclast chemotaxis and activation. METHODS: Gene expression of these factors was assessed using quantitative real-time polymerase chain reaction, in samples obtained from healthy gingiva (n = 8), periapical granulomas (n = 20), and cysts (n = 10). RESULTS: Periapical cysts exhibited a greater expression of GATA-3, while a greater expression of T-bet, Foxp3, and interleukin-10 (IL-10) was seen in granulomas. The expression of interferon-gamma, IL-4, and transforming growth factor-beta was similar in both lesions. Regarding osteoclastic factors, while the expression of SDF-1alpha/CXCL12 and CCR1 was higher in cysts, the expression of RANKL was significantly higher in granulomas. Both lesions exhibited similar expression of CXCR4, CKbeta8/CCL23, and osteoprotegerin, which were significantly higher than in control. CONCLUSION: Our results showed a predominance of osteoclast activity in granulomas that was correlated with the Th1 response. The concomitant expression of Treg cell markers suggests a possible suppression of the Th1 response in granulomas. On the other hand, in cysts the Th2 activity is augmented. The mechanisms of periradicular lesion development are still not fully understood but the imbalance of immune and osteoclastic cell activity in cysts and granulomas seems to be critically regulated by Treg cells.
Assuntos
Osteoclastos/fisiologia , Granuloma Periapical/imunologia , Cisto Radicular/imunologia , Linfócitos T Reguladores/imunologia , Células Th1/imunologia , Células Th2/imunologia , Adulto , Perda do Osso Alveolar/imunologia , Perda do Osso Alveolar/metabolismo , Quimiocina CCL3/biossíntese , Quimiocina CXCL12/biossíntese , Quimiocinas CC/biossíntese , Quimiotaxia , Doença Crônica , Fatores de Transcrição Forkhead/biossíntese , Fator de Transcrição GATA3/biossíntese , Expressão Gênica , Humanos , Interferon gama/biossíntese , Interleucina-10/biossíntese , Pessoa de Meia-Idade , Osteoprotegerina/biossíntese , Granuloma Periapical/metabolismo , Ligante RANK/biossíntese , Cisto Radicular/metabolismo , Receptores CCR1/biossíntese , Receptores CXCR4/biossíntese , Proteínas com Domínio T/biossínteseRESUMO
BACKGROUND AND OBJECTIVE: Inflammatory cytokines such as tumor necrosis factor-alpha are involved in the pathogenesis of periodontal diseases. A high between-subject variation in the level of tumor necrosis factor-alpha mRNA has been verified, which may be a result of genetic polymorphisms and/or the presence of periodontopathogens such as Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola (called the red complex) and Aggregatibacter actinomycetemcomitans. In this study, we investigated the effect of the tumor necrosis factor-alpha (TNFA) -308G/A gene polymorphism and of periodontopathogens on the tumor necrosis factor-alpha levels in the periodontal tissues of nonsmoking patients with chronic periodontitis (n = 127) and in control subjects (n = 177). MATERIAL AND METHODS: The TNFA -308G/A single nucleotide polymorphism was investigated using polymerase chain reaction-restriction fragment length polymorphism analysis, whereas the tumor necrosis factor-alpha levels and the periodontopathogen load were determined using real-time polymerase chain reaction. RESULTS: No statistically significant differences were found in the frequency of the TNFA -308 single nucleotide polymorphism in control and chronic periodontitis groups, in spite of the higher frequency of the A allele in the chronic periodontitis group. The concomitant analyses of genotypes and periodontopathogens demonstrated that TNFA -308 GA/AA genotypes and the red-complex periodontopathogens were independently associated with increased levels of tumor necrosis factor-alpha in periodontal tissues, and no additive effect was seen when both factors were present. P. gingivalis, T. forsythia and T. denticola counts were positively correlated with the level of tumor necrosis factor-alpha. TNFA -308 genotypes were not associated with the periodontopathogen detection odds or with the bacterial load. CONCLUSION: Our results demonstrate that the TNFA -308 A allele and red-complex periodontopathogens are independently associated with increased levels of tumor necrosis factor-alpha in diseased tissues of nonsmoking chronic periodontitis patients and consequently are potentially involved in determining the disease outcome.
Assuntos
Adenina , Bacteroides/fisiologia , Periodontite Crônica/imunologia , Guanina , Polimorfismo de Nucleotídeo Único/genética , Porphyromonas gingivalis/fisiologia , Treponema denticola/fisiologia , Fator de Necrose Tumoral alfa/genética , Adulto , Aggregatibacter actinomycetemcomitans/fisiologia , Periodontite Crônica/microbiologia , Feminino , Frequência do Gene/genética , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Perda da Inserção Periodontal/imunologia , Perda da Inserção Periodontal/microbiologia , Bolsa Periodontal/imunologia , Bolsa Periodontal/microbiologia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição/genética , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
BACKGROUND AND OBJECTIVE: Inflammatory immune reactions that occur in response to periodontopathogens are thought to protect the host against infection, but may trigger periodontal destruction. However, the molecular and genetic mechanisms underlying host susceptibility to periodontal infection and to periodontitis development have still not been established in detail. MATERIAL AND METHODS: In this study, we examined the mechanisms that modulate the outcome of Aggregatibacter (Actinobacillus) actinomycetemcomitans-induced periodontal disease in mice mouse strains selected for maximal (AIRmax) or minimal (AIRmin) inflammatory reactions. RESULTS: Our results showed that AIRmax mice developed a more severe periodontitis than AIRmin mice in response to A. actinomycetemcomitans infection, and this periodontitis was characterized by increased alveolar bone loss and inflammatory cell migration to periodontal tissues. In addition, enzyme-linked immunosorbent assays demonstrated that the levels of the cytokines interleukin-1beta, tumor necrosis factor-alpha and interleukin-17 were higher in AIRmax mice, as were the levels of matrix metalloproteinase (MMP)-2, MMP-13 and receptor activator of nuclear factor-kappaB ligand (RANKL) mRNA levels. However, the more intense inflammatory immune reaction raised by the AIRmax strain, in spite of the higher levels of antimicrobial mediators myeloperoxidase and inducible nitric oxide synthase, did not enhance the protective immunity to A. actinomycetemcomitans infection, because both AIRmax and AIRmin strains presented similar bacterial loads in periodontal tissues. In addition, the AIRmax strain presented a trend towards higher levels of serum C-reactive protein during the course of disease. CONCLUSION: Our results demonstrate that the intensity of the inflammatory immune reaction is associated with the severity of experimental periodontitis, but not with the control of A. actinomycetemcomitans periodontal infection, suggesting that the occurrence of hyperinflammatory genotypes may not be an evolutionary advantage in the complex host-pathogen interaction observed in periodontal diseases.
Assuntos
Infecções por Actinobacillus/imunologia , Aggregatibacter actinomycetemcomitans/imunologia , Perda do Osso Alveolar/imunologia , Periodontite/imunologia , Perda do Osso Alveolar/microbiologia , Animais , Proteína C-Reativa/análise , Movimento Celular/fisiologia , Contagem de Colônia Microbiana , Suscetibilidade a Doenças/imunologia , Interações Hospedeiro-Patógeno , Interleucina-17/análise , Interleucina-1beta/análise , Contagem de Leucócitos , Leucócitos/imunologia , Masculino , Metaloproteinase 13 da Matriz/análise , Metaloproteinase 2 da Matriz/análise , Camundongos , Óxido Nítrico Sintase Tipo II/análise , Osteoprotegerina/análise , Periodontite/sangue , Periodontite/microbiologia , Peroxidase/análise , Ligante RANK/análise , Inibidor Tecidual de Metaloproteinase-1/análise , Inibidor Tecidual de Metaloproteinase-3/análise , Fator de Necrose Tumoral alfa/análiseRESUMO
Nitric oxide (NO) derived from inducible nitric oxide synthase (iNOS) plays an important role in host defense, as well as in inflammation-induced tissue lesions. Here we evaluated the role of NO in bone loss in bacterial infection-induced apical periodontitis by using iNOS-deficient mice (iNOS(-/-)). The iNOS(-/-) mice developed greater inflammatory cell recruitment and osteolytic lesions than WT mice. Moreover, tartrate-resistant acid-phosphatase-positive (TRAP(+)) osteoclasts were significantly more numerous in iNOS(-/-) mice. Furthermore, the increased bone resorption in iNOS(-/-) mice also correlated with the increased expression of receptor activator NF-kappaB (RANK), stromal-cell-derived factor-1 alpha (SDF-1 alpha/CXCL12), and reduced expression of osteoprotegerin (OPG). These results show that NO deficiency was associated with an imbalance of bone-resorption-modulating factors, leading to severe infection-stimulated bone loss.