osteoprotegerin and Periodontitis

A new classification for periodontitis has been adopted in clinical practice. However, there are still discussions regarding this new classification and difficulties in its adoption, both by professionals and researchers. Thus, this study aimed to evaluate which salivary biomarkers are present in periodontitis, following the new classification of periodontal diseases through meta-analysis.. A literature search was carried out in the scientific databases: PubMed, Scielo and Google scholar to select studies. The selection of studies was followed by two authors upon reading of the title, abstract and full text. The necessary data were collected and statistical analyses were performed using the Review Manager statistical software version 5.4, with calculation of Mean Difference, heterogeneity (I²) and funnel plot with P < 0.05.. After following the selection criteria, 9 articles were selected for comparison. The studies address the presence of biomarkers in the saliva of patients with periodontitis and their possible use in the monitoring and diagnosis of the disease. For the meta-analytic comparison, a sample size of 1,983 individuals was used. Statistical analyses showed that nitric oxide, IL-6, IL-1B and osteoprotegerin are substances that are significantly present in patients with periodontitis (P < 0.05).. IL-6, nitric oxide, IL-1B, TNF-α and osteoprotegerin are among the most present biomarkers in patients with periodontitis, and may be used in the future as a monitoring of periodontal disease. The present study also revealed that there was no statistically significant difference in the concentration of these biomarkers for clinical distinction from periodontitis.

Topics: Biomarkers; Chronic Periodontitis; Humans; Interleukin-6; Nitric Oxide; Osteoprotegerin; Periodontitis; Saliva

Periodontal disease is characterized by inflammation of the periodontal tissue and subsequent destruction of the alveolar bone. It is one of the most common infectious diseases in humans, being the leading cause of tooth loss in adults. Recently, it has been shown that the receptor activator of NF-κB ligand (RANKL) produced by osteoblasts and periodontal ligament fibroblasts critically contributes to the bone destruction caused by periodontal disease. Activation of the immune system plays an important role in the induction of RANKL during periodontal inflammation. Here we discuss the molecular mechanisms of periodontal bone destruction by focusing on the osteoimmune molecule RANKL.

Topics: Humans; Inflammation; Osteoclasts; Osteoprotegerin; Periodontal Diseases; Periodontal Ligament; Periodontitis; RANK Ligand

Periodontopathic bacteria constantly stimulate the host, which causes an immune response, leading to host-induced periodontal tissue damage. The complex interaction and imbalance between Th17 and Treg cells may be critical in the pathogenesis of periodontitis. Furthermore, the RANKL/RANK/OPG system plays a significant role in periodontitis bone metabolism, and its relationship with the Th17/Treg cell imbalance may be a bridge between periodontal bone metabolism and the immune system. This article reviews the literature related to the Th17/Treg cell imbalance mediated by pathogenic periodontal microbes, and its mechanism involving RANKL/RANK/OPG in periodontitis bone metabolism, in an effort to provide new ideas for the study of the immunopathological mechanism of periodontitis.

Topics: Alveolar Bone Loss; Humans; Osteoprotegerin; Periodontitis; RANK Ligand; T-Lymphocytes, Regulatory; Th17 Cells

The process of bone remodeling is the result of the regulated balance between bone cell populations, namely bone-forming osteoblasts, bone-resorbing osteoclasts, and the osteocyte, the mechanosensory cell type. Osteoclasts derived from the hematopoietic stem cell lineage are the principal cells involved in bone resorption. In osteolytic diseases such as rheumatoid arthritis, periodontitis, and osteoporosis, the balance is lost and changes in favor of bone resorption. Therefore, it is vital to elucidate the mechanisms of osteoclast formation and bone resorption. It has been reported that osteocytes express Receptor activator of nuclear factor κΒ ligand (RANKL), an essential factor for osteoclast formation. RANKL secreted by osteocytes is the most important factor for physiologically supported osteoclast formation in the developing skeleton and in pathological bone resorption such as experimental periodontal bone loss. TNF-α directly enhances RANKL expression in osteocytes and promotes osteoclast formation. Moreover, TNF-α enhances sclerostin expression in osteocytes, which also increases osteoclast formation. These findings suggest that osteocyte-related cytokines act directly to enhance osteoclast formation and bone resorption. In this review, we outline the most recent knowledge concerning bone resorption-related cytokines and discuss the osteocyte as the master regulator of bone resorption and effector in osteoclast formation.

Topics: Adaptor Proteins, Signal Transducing; Animals; Arthritis, Rheumatoid; Bone Resorption; Cytokines; Gene Expression Regulation, Developmental; Humans; Intercellular Signaling Peptides and Proteins; Osteoclasts; Osteocytes; Osteogenesis; Osteoporosis; Osteoprotegerin; Periodontitis; RANK Ligand; Signal Transduction

The impact of diabetes mellitus on the prevalence, severity and progression of periodontal disease has been known for many years and intense efforts have been made to elucidate the underlying mechanisms. It is widely reported that hyperglycemia causes numerous systemic changes, including altered innate immune-cell function and metabolic changes. The aim of this review was to summarize and discuss the evidence for mechanisms that probably play a role in the altered local inflammatory reactions in the periodontium of patients with diabetes, focusing on local changes in cytokine levels, matrix metalloproteinases, reactive oxygen species, advanced glycation end-products, immune-cell functions, the RANKL/osteoprotegerin axis and toll-like receptors. Apart from the systemic effects of diabetes, recent evidence suggests that local changes in the periodontal tissues are characterized by enhanced interactions between leukocytes and endothelial cells and by altered leukocyte functions [resulting in increased levels of reactive oxygen species and of proinflammatory cytokines (interleukin-1β, interleukin-6 and tumor necrosis factor-α)]. These local changes are amplified by the enhanced accumulation of advanced glycation end-products and their interaction with receptors for advanced glycation end-products. Furthermore, the increased levels of proinflammatory cytokines lead to an up-regulation of RANKL in periodontal tissues, stimulating further periodontal tissue breakdown.

Topics: Animals; Cytokines; Diabetes Complications; Gingival Crevicular Fluid; Glycation End Products, Advanced; Humans; Immunity, Innate; Matrix Metalloproteinases; Osteoprotegerin; Periodontitis; Periodontium; RANK Ligand; Reactive Oxygen Species; Toll-Like Receptors

The receptor activator of NF-κB ligand-osteoprotegerin (RANKL-OPG) bi-molecular system is the "bottle-neck" regulator of osteoclastogenesis and bone resorption, both in physiological and pathological conditions. This review aims to elaborate the current knowledge on RANKL and OPG in periodontal disease, and to evaluate their diagnostic and prognostic potential as biomarkers of the disease.. To pursue this aim, electronic and manual searches were performed for identifying clinical and in vivo studies on RANKL and OPG in gingival tissue, gingival crevicular fluid, saliva and blood. Smoking and diabetes mellitus were also considered for their potential effects.. Papers fulfilling the inclusion criteria demonstrate that RANKL is up-regulated, whereas OPG is down-regulated in periodontitis, compared to periodontal health, resulting in an increased RANKL/OPG ratio. This ratio is further up-regulated in smokers and diabetics, and is not affected by conventional periodontal treatment.. The increased RANKL/OPG ratio may serve as a biomarker that denotes the occurrence of periodontitis, but may not necessarily predict on-going disease activity. Its steadily elevated levels post treatment may indicate that the molecular mechanisms of bone resorption are still active, holding an imminent risk for relapse of the disease. Additional adjunct treatment modalities that would "switch-off" the RANKL/OPG ratio may therefore be required.

Topics: Alveolar Bone Loss; Animals; Biomarkers; Dental Plaque; Diabetes Mellitus; Gingiva; Gingival Crevicular Fluid; Humans; Lymphocytes; Osteoblasts; Osteoporosis; Osteoprotegerin; Periodontal Ligament; Periodontitis; RANK Ligand; Saliva; Smoking

To review current knowledge on cytokine interactions and the cytokine-mediated links between innate and adaptive immunity that are relevant to the pathophysiology of periodontitis.. A structured review of the literature was undertaken to identify relevant research publications using a Medline search from 1950 to September 2010. The focus of the search was on the functional role of cytokines, i.e. their actions and responses relevant to the pathogenesis of periodontal disease rather than more descriptive studies of their expression in tissues and body fluids. It was not possible to conduct a traditional systematic review with a focussed question due to the heterogeneity of published research.. There is enormous heterogeneity in the periodontal literature in terms of experimental approaches. We have the deepest understanding of the role of the pro-inflammatory cytokines [e.g. interleukin (IL)-1β, tumour necrosis factor-α, IL-6] with accumulating data on T-cell regulatory cytokines (e.g. IL-12, IL-18), chemokines and cytokines which mediate bone cell development and function (e.g. receptor activator of NF-κB ligand, osteoprotegerin). It is clear that there are multiple, overlapping and complex functional links between cytokines with regulatory control exerted at a number of levels and involving numerous cell types (both immune cells and resident cells in the periodontium).. Cytokines appear to interact functionally in networks in the periodontium and integrate aspects of innate and adaptive immunity. However, our understanding is far from complete, particularly how molecular and cellular pathways relate to disease pathogenesis. We should adopt consistent experimental approaches to gain better insight into the totality of cytokine networks and how they drive immune responses in the periodontium.

Topics: Adaptive Immunity; Chemokines; Cytokines; Humans; Immunity, Innate; Inflammation Mediators; Interleukin-1beta; Interleukins; Osteoprotegerin; Periodontitis; Receptor Activator of Nuclear Factor-kappa B; Tumor Necrosis Factor-alpha

Topics: Alveolar Bone Loss; Animals; Cytokines; fas Receptor; Humans; Inflammation Mediators; Intracellular Signaling Peptides and Proteins; Macrophage Colony-Stimulating Factor; Osteoclasts; Osteoprotegerin; Periodontitis; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B

Osteoimmunology is defined as the research area focusing on the crosstalk between the immune system and the muskoskeletal system. After nearly a decade of research, we are now beginning to understand the basic principles of this crosstalk. It seems that almost all immune cells are capable of communicating with osteoblasts, osteoclasts, and their respective progenitors - and vice versa. Diseases that fall into the category of osteoimmunology including osteoporosis, rheumatoid arthritis, and periodontal disease are of particular significance considering their implications in quality of life, their increased incidence in the population, and socioeconomic issues. To better understand the underlying pathogenesis, the main pathways of the crosstalk between the immune system and the muskoskeletal system need to be uncovered. Our current understanding has already provided the scientific basis for the development of targeted therapies. However, the challenge of future studies is to further decipher this crosstalk at cellular and molecular levels.

Topics: Arthritis, Rheumatoid; Bone and Bones; Bone Diseases; Cell Communication; Hematopoietic Stem Cells; Humans; Immunity, Cellular; Osteoblasts; Osteoclasts; Osteoporosis; Osteoprotegerin; Periodontitis; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; T-Lymphocytes

Inflammation and bone loss are hallmarks of periodontal disease (PD). The question is how the former leads to the latter. Accumulated evidence demonstrates that PD involves bacterially derived factors and antigens that stimulate a local inflammatory reaction and activation of the innate immune system. Proinflammatory molecules and cytokine networks play essential roles in this process. Interleukin-1 and tumor necrosis factor-alpha seem to be primary molecules that, in turn, influence cells in the lesion. Antigen-stimulated lymphocytes (B and T cells) also seem to be important. Eventually, a cascade of events leads to osteoclastogenesis and subsequent bone loss via the receptor activator of nuclear factor-kappa B (RANK)-RANK ligand (RANKL)-osteoprotegerin (OPG) axis. This axis and its regulation are not unique to PD but rather are critical for pathologic lesions involving chronic inflammation. Multiple lines of evidence in models of PD clearly indicate that increases in RANKL mRNA expression and protein production increase the RANKL/OPG ratio and stimulate the differentiation of macrophage precursor cells into osteoclasts. They also stimulate the maturation and survival of the osteoclast, leading to bone loss. OPG mRNA expression and protein production do not generally seem to be increased in the periodontitis lesion. Studies of RANKL and OPG transgenic and knockout animals provide further support for the involvement of these molecules in the tissue loss observed in PD. Ironically, periodontal practitioners have focused on the bacterial etiology of PD and believed that plaque removal was aimed at eliminating specific bacteria or bacterial complexes. However, it seems that the reduction of inflammation and attenuation of the host's immune reaction to the microbial plaque, eventually leading to a decrease in the ratio of RANKL/OPG and a decrease in associated bone loss, are the actual and desired outcomes of periodontal therapy. Future therapeutic options are likely to have regulation of the RANK-RANKL-OPG axis as their goal.

Topics: Alveolar Bone Loss; Antigens; Humans; Immunity, Innate; Inflammation; Inflammation Mediators; Osteoclasts; Osteoprotegerin; Periodontal Diseases; Periodontitis; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B

Topics: Alveolar Bone Loss; Animals; Antibodies, Bacterial; Bacterial Vaccines; Gingiva; Humans; Inflammation Mediators; Osteoblasts; Osteoprotegerin; Periodontal Ligament; Periodontitis; RANK Ligand

Periodontitis and rheumatoid arthritis (RA) appear to share many pathologic features. In this review, the common pathologic mechanisms of these two common chronic conditions are explored. Emerging evidence now suggests a strong relationship between the extent and severity of periodontal disease and RA. While this relationship is unlikely to be causal, it is clear that individuals with advanced RA are more likely to experience more significant periodontal problems compared to their non-RA counterparts, and vice versa. A case is made that these two diseases could be very closely related through common underlying dysfunction of fundamental inflammatory mechanisms. The nature of such dysfunction is still unknown. Nonetheless, there is accruing evidence to support the notion that both conditions manifest as a result of an imbalance between proinflammatory and anti-inflammatory cytokines. As a result, new treatment strategies are expected to emerge for both diseases that may target the inhibition of proinflammatory cytokines and destructive proteases. The clinical implications of the current data dictate that patients with RA should be carefully screened for their periodontal status.

Topics: Animals; Antirheumatic Agents; Arthritis, Rheumatoid; Carrier Proteins; Cytokines; Genetic Predisposition to Disease; Glycoproteins; Humans; Immunosuppressive Agents; Inflammation Mediators; Membrane Glycoproteins; Osteoclasts; Osteoprotegerin; Periodontitis; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor

Over the past decade there have been major advances in our understanding of the factors that regulate osteoclast formation and activity. It is now apparent that receptor activator NFkappaB (RANK), its ligand, RANKL (also known as TRANCE, osteoclast differentiation factor and osteoprotegerin (OPG) ligand) and the natural RANKL inhibitor, OPG, are the key factors regulating osteoclast formation in normal bone physiology. The molecular interactions of these molecules regulate osteoclast formation and subsequent bone loss in disease and there is now strong evidence that the bone loss associated with inflammatory diseases, such as rheumatoid arthritis, periodontal disease and peri-implant loosening, is regulated by the action of RANK, RANKL, and OPG. These molecules are targets for the pharmacological regulation of severe bone loss in several common inflammatory diseases.

Topics: Animals; Arthritis, Rheumatoid; Bone Resorption; Carrier Proteins; Cell Differentiation; Glycoproteins; Humans; Ligands; Membrane Glycoproteins; NF-kappa B; Osteitis; Osteoclasts; Osteolysis; Osteoprotegerin; Periodontitis; Prosthesis Failure; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor

To measure the changes in tooth mobility, alveolar bone, and receptor activator of nuclear factor kappa-B ligand (RANKL)/osteoprotegerin (OPG) in the gingival crevicular fluid (GCF) during orthodontic treatment to regain incisal function in the presence and absence of biting exercises.. Thirty-six females (42.3 ± 6.5 years old) with periodontally compromised upper incisors received orthodontic treatment to obtain ideal incisor relationships. Eighteen subjects in the experimental biting exercise group were instructed to bite a soft plastic roll for 5 min/d; the 18 control subjects were not given plastic rolls. Alveolar bone thickness, height, and density around the upper incisors were assessed at three root levels using cone-beam computed tomography. GCF was collected at the labial and palatal sites of the upper incisors at pretreatment (T0), end of treatment (T1), 1 month after T1 (T2), and 7 months after T1 (T3). RANKL/OPG was determined using enzyme-linked immunosorbent assays.. Labial and palatal bone thickness significantly increased (>twofold) from T1 to T3 in the experimental group at all three root levels (all P < .05). Bone thickness correlated negatively with RANKL/OPG ratio between T1 and T2 ( P < .05). Tooth mobility, bone height, and density were not significantly different between T1 and T3.. Biting exercises significantly increased bone thickness but did not affect tooth mobility, bone height, or density. The RANKL/OPG ratio decreased 1 month after treatment (T2) and correlated with increased bone thickness. ( ClinicalTrials.in.th TCTR20170625001).

Topics: Adult; Alveolar Bone Loss; Cone-Beam Computed Tomography; Exercise Therapy; Female; Gingival Crevicular Fluid; Humans; Incisor; Maxilla; Osteoprotegerin; Periodontitis; RANK Ligand; Tooth Mobility; Treatment Outcome

The present study aimed to evaluate proinflammatory cytokine and vitamin D levels in rheumatoid arthritis (RA) and chronic periodontitis (CP) patients and healthy individuals before and after initial periodontal treatment. Overall, 17 CP patients with RA (RA + CP), 18 systemically healthy CP patients (CP), and 18 healthy controls (C) were included. Clinical periodontal measurements were recorded and gingival crevicular fluid (GCF) and blood samples were recorded. RA + CP and CP patients received nonsurgical periodontal treatment. Vitamin D, tumor necrosis factor (TNF)-α, receptor activator of nuclear factor-KB ligand (RANKL), and OPG levels were determined in GCF and serum. Baseline clinical parameters were similar in all periodontitis groups (P > 0.05) but were higher than that in controls (P < 0.05). Periodontal treatment improved clinical parameters in all periodontitis groups (P < 0.05). GCF vitamin D levels were higher in RA + CP and CP groups than in healthy controls, but these levels decreased in the RA + CP group after periodontal treatment (P < 0.05). Serum RANKL and GCF TNF-α levels in RA patients decreased after periodontal treatment (P < 0.05). Within the limitations of this study, the results suggested that GCF vitamin D levels are increased in RA patients and decrease after periodontal treatment; therefore, local vitamin D levels might be an important indicator of periodontal bone loss.

Topics: Adult; Arthritis, Rheumatoid; Case-Control Studies; Female; Gingival Crevicular Fluid; Humans; Male; Middle Aged; Osteoprotegerin; Periodontitis; RANK Ligand; Tumor Necrosis Factor-alpha; Vitamin D

Assess the ability of a panel of gingival crevicular fluid (GCF) biomarkers as predictors of periodontal disease progression (PDP).. In this study, 100 individuals participated in a 12-month longitudinal investigation and were categorized into four groups according to their periodontal status. GCF, clinical parameters and saliva were collected bi-monthly. Subgingival plaque and serum were collected bi-annually. For 6 months, no periodontal treatment was provided. At 6 months, patients received periodontal therapy and continued participation from 6 to 12 months. GCF samples were analysed by ELISA for MMP-8, MMP-9, Osteoprotegerin, C-reactive Protein and IL-1β. Differences in median levels of GCF biomarkers were compared between stable and progressing participants using Wilcoxon Rank Sum test (p = 0.05). Clustering algorithm was used to evaluate the ability of oral biomarkers to classify patients as either stable or progressing.. Eighty-three individuals completed the 6-month monitoring phase. With the exception of GCF C-reactive protein, all biomarkers were significantly higher in the PDP group compared to stable patients. Clustering analysis showed highest sensitivity levels when biofilm pathogens and GCF biomarkers were combined with clinical measures, 74% (95% CI = 61, 86).. Signature of GCF fluid-derived biomarkers combined with pathogens and clinical measures provides a sensitive measure for discrimination of PDP (ClinicalTrials.gov NCT00277745).

Topics: Biofilms; Biomarkers; C-Reactive Protein; Chronic Periodontitis; Cohort Studies; Dental Plaque; Dental Scaling; Disease Progression; Follow-Up Studies; Forecasting; Gingival Crevicular Fluid; Gingivitis; Humans; Interleukin-1beta; Longitudinal Studies; Matrix Metalloproteinase 8; Matrix Metalloproteinase 9; Osteoprotegerin; Periodontitis; Root Planing; Saliva; Sensitivity and Specificity

Smoking can be considered a risk factor for chronic apical periodontitis (CAP). This study compared the immunoexpression of biomarkers receptor activator of nuclear factor kappa B ligand (RANKL), osteoprotegerin (OPG), osteopontin (OPN), and tumor necrosis factor alpha (TNF-α) in CAP in smokers and nonsmokers.. Twelve smokers and 12 nonsmokers diagnosed with CAP and indicated for tooth extraction were selected. Exclusion factors were teeth with a diagnosis of root fracture, previous endodontic treatment, or endoperiodontal injury, in addition to individuals with systemic diseases, under 18 years of age, users of anti-inflammatory and/or antibiotics in the last 3 months, and drug users. Specimens were processed for histopathologic and immunohistochemical analysis.. Qualitative analysis of RANKL expression showed 66.66% weak/moderate and 33.33% strong in smokers and 100% weak/moderate in nonsmokers. OPG and OPN expressions were 100% negative to focal in the smoker group and 50% negative to focal and 50% weak/moderate in the nonsmoker group. TNF-α was 25% negative to focal and 75% weak/moderate in the smoker group and 33.33% negative to focal and 66.66% weak/moderate in the nonsmoker group. Quantitative analysis of the data using the Mann-Whitney U test showed that there was a significant difference in the immunoexpression of RANKL (P < .05), OPG (P < .05), and OPN (P < .05), but there was no statistical difference in the immunoexpression of TNF-α (P > .05) between the 2 groups.. These findings suggest that smoking is capable of altering the inflammatory response, influencing the evolution of CAP.

Topics: Adolescent; Humans; Infant; NF-kappa B; Osteopontin; Osteoprotegerin; Periapical Periodontitis; Periodontitis; RANK Ligand; Smokers; Tumor Necrosis Factor-alpha

During orthodontic treatment, diverse cytokines, enzymes, and osteolytic mediators produced within the teeth surrounding periodontal tissues determine the rate of alveolar bone remodeling and consequent teeth movement. In patients with teeth presenting reduced periodontal support, periodontal stability should be ensured during orthodontic treatment. Thus, therapies based on the application of low-intensity intermittent orthodontic forces are recommended. To determine if this kind of treatment is periodontally well tolerated, this study aimed to analyze the production of receptor activator of nuclear factor kappa-B ligand (RANKL), osteoprotegerin (OPG), interleukin (IL)-6, IL-17A, and matrix metalloproteinase (MMP)-8 in periodontal tissues of protruded anterior teeth with reduced periodontal support and undergoing orthodontic treatment. Patients with periodontitis-associated anterior teeth migration received non-surgical periodontal therapy and a specific orthodontic treatment involving controlled low-intensity intermittent orthodontic forces. Samples were collected before periodontitis treatment, after periodontitis treatment, and at 1 week to 24 months of the orthodontic treatment. During the 2 years of orthodontic treatment, no significant differences were detected in the probing depth, clinical attachment level, supragingival bacterial plaque, and bleeding on probing. In line with this, the gingival crevicular levels of RANKL, OPG, IL-6, IL-17A, and MMP-8 did not vary between the different evaluation time-points of the orthodontic treatment. When compared with the levels detected during the periodontitis, the RANKL/OPG ratio was significantly lower at all the analyzed time-points of the orthodontic treatment. In conclusion, the patient-specific orthodontic treatment based on intermittent orthodontic forces of low intensities was well tolerated by periodontally compromised teeth with pathological migration.

Topics: Bone Resorption; Cytokines; Gingiva; Gingival Crevicular Fluid; Humans; Interleukin-17; Interleukin-6; Orthodontics; Osteoprotegerin; Periodontitis; RANK Ligand

Periodontitis (POD) is an infectious process directed at the structures supporting the teeth. Destruction of alveolar bone is considered one of the main causes of tooth loss in humans and is mediated by the host immune response. Osteoprotegerin (OPG), a protein that inhibits bone resorption by binding to the RANK ligand (RANKL), prevents osteoclastic differentiation. The aim of the study was to determine the plasma levels of OPG in patients with POD.. a case-control study with forty-nine patients with POD and 49 healthy controls were included in the study. OPG levels were determined by an ELISA test in plasma samples.. OPG values (1.6203 ng/mL) were higher in the POD group compared with control group (1.2824 ng/mL). Among the studied groups, we detected significant differences in age, glycosylated haemoglobin (HbA1C), and plasma concentration of OPG (p < 0.05).. plasma OPG levels are associated with bone formation and destruction processes, suggesting that OPG acts in a protective manner.

Topics: Alveolar Bone Loss; Case-Control Studies; Humans; Osteoprotegerin; Periodontitis; RANK Ligand

To investigate the effect of voluntary physical activity (VPA) on inflammatory profile and the progression of experimental periodontal disease (PD) in mice.. Male C57BL/6 mice were randomly distributed into Control; VPA; PD and PD/VPA groups. We registered VPA (total volume of revolutions) and average speed (revolutions/minute) in a free running wheel for 30 days. On the 15th day, animals from the PD and PD/VPA groups received ligatures on the upper second molars bilaterally. On the 30th day animals were euthanized, and PD progression was assessed by measuring alveolar bone loss (ABL - the linear distance between the cemento-enamel junction and the alveolar bone crest on the teeth buccal surface). Gene expression of RANKL (kappa nuclear factor B receptor) OPG (osteoprotegerin), IL-1β (interleukin 1 beta), IL-6 (interleukin 6) and TNF-α (tumor necrosis factor alpha) were evaluated by real-time PCR (quantitative Polymerase Chain Reaction - relative gene expression).. The total volume of physical activity and the activity speed decreased along the seven days after ligature-placement (p < 0.05), returning to a similar pattern in relation to VPA group. Ligature placement produced significant bone resorption, and increased RANKL, IL-1β, IL-6 and TNF-α expression. VPA reduced ABL (p < 0,05) and the expression of TNF-α and IL-1β, whereas increased OPG expression.. Animals induced to PD with access to the VPA wheel presented both lower gingival inflammation and less alveolar bone resorption in comparison to animals without access to the wheel.

Topics: Alveolar Bone Loss; Animals; Interleukin-6; Male; Mice; Mice, Inbred C57BL; Osteoprotegerin; Periodontitis; RANK Ligand; Tumor Necrosis Factor-alpha

To investigate whether periodontitis impacts bone homeostasis via gut microbiota regulation.. Experimental periodontitis was induced by ligatures (LIG group). ApoE. Periodontitis may impair systemic bone homeostasis through gut microbiota.

Topics: Alveolar Bone Loss; Animals; Anti-Bacterial Agents; Apolipoproteins E; Biomarkers; Gastrointestinal Microbiome; Homeostasis; Mice; Mice, Knockout, ApoE; Osteoclasts; Osteoprotegerin; Periodontitis; RANK Ligand

The aim of the present study was to evaluate the inhibitory effects of oxytocin on the development of periodontitis based on its properties against bone loss and resorption. Thirty-two Wistar albino rats were divided into four equal groups: control, periodontitis + saline, periodontitis + 0.5 mg/kg/day oxytocin, and periodontitis + 1 mg/kg/day oxytocin. Periodontitis groups received 4.0 silk ligatures around their cervixes of the right and left mandibular incisors in an "8" shape, kept for 14 days. Animals in oxytocin groups were injected once every day during 14 days with oxytocin. The mandibles were fixed and scanned using microcomputed tomography to quantify bone resorption and volumetric measurements. Blood samples were collected to analyze the concentrations of macrophage colony-stimulating factor (M-CSF), receptor activator of nuclear factor-κΒ ligand (RANKL), osteoprotegerin (OPG), matrix metalloproteinase-8 (MMP-8), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, glutathione peroxidase (GPx), superoxide dismutase (SOD), and malondialdehyde (MDA). Histopathological evaluations were conducted to examine the gingiva and alveolar bone. Oxytocin prevented the development of periodontitis by decreasing ligament deteriorations and leukocytes in the gingival connective tissue and promoting reintegration with the alveolar bone. Bone resorption in all regions was less in the periodontitis + 1 mg/kg/day oxytocin group than in the periodontitis + saline group. Although TNF-α, IL-6, and RANKL values were lower in the periodontitis + 1 mg/kg/day oxytocin group, OPG was higher than that in the periodontitis + saline group. M-CSF, MMP-8, and MDA were lower in the oxytocin groups than in the periodontitis + saline group. Oxytocin may be an effective agent for periodontal diseases because it decreased bone resorption, oxidative stress, and inflammation in an experimental periodontitis.

Topics: Alveolar Bone Loss; Animals; Female; Interleukin-1beta; Macrophage Colony-Stimulating Factor; Matrix Metalloproteinase 8; Osteoprotegerin; Oxytocin; Periodontitis; RANK Ligand; Rats; Rats, Wistar; Tumor Necrosis Factor-alpha; X-Ray Microtomography

This study evaluated the effects of Bifidobacterium animalis subsp. lactis HN019 (B. lactis HN019) in the development of periodontitis (PE), associated or not with metabolic syndrome, (MS) in rats.. Ninety-six rats were grouped according to a food protocol: high-fat diet for induction of MS or standard diet for the control groups (C). They were subdivided into groups with (+) and without (-) PE, receiving (*) or not (**) probiotic (PROB): C-**, CP-*, PE+**, PEP+*, MS- MSP-*, MSPE+**, and MSPEP+*. PROB administration started on the eighth week of the study and PE was induced on the 14th week by placing ligature on the animals' lower first molars. Euthanasia occurred in the 16th week. Biomolecular analyzes, immunoenzymatic assays, and microtomographic analyses were performed. The data obtained were analyzed statistically (P < 0.05).. The PEP and MSPEP groups showed lower levels of alveolar bone loss when compared with the PE and MSPE groups, respectively (P < 0.05). The immunoenzymatic analysis showed higher levels of interleukin (IL)-1β and a higher receptor activator of NF-kappaB ligand (RANKL)/osteoprotegerin (OPG) ratio in the MSPE group when compared with the MSPEP group (P < 0.05). The PEP group showed lower levels of tumor necrosis factor (TNF)-α and IL-6 when compared with the PE group. The use of PROB attenuated dyslipidemia parameters in animals with MS, with or without PE.. B. lactis HN019 reduced more significantly the severity of PE in rats with MS, modulating both systemic metabolic and immunoinflammatory parameters in periodontal tissues.

Topics: Alveolar Bone Loss; Animals; Bifidobacterium animalis; Metabolic Syndrome; Osteoprotegerin; Periodontitis; Probiotics; RANK Ligand; Rats; Rats, Wistar; Tumor Necrosis Factor-alpha

To investigate the effect of chitosan oligosaccharide on alveolar bone resorption, Th17/Treg balance and OPG/RANKL/RANK pathway in rats with periodontitis.. Rat model of periodontitis was established, and the periodontitis rats were randomly divided into model group, low-dose chitosan oligosaccharide group, middle-dose chitosan oligosaccharide group, high-dose chitosan oligosaccharide group and metronidazole group, with 12 rats in each group, another 12 rats were set as control group. After treatment, gingival index and alveolar bone absorption were evaluated. H-E staining was used to observe the pathological changes of periodontal tissues. The ratio of Th17/Treg cells in peripheral blood was detected by flow cytometry, the levels of serum IL-17, TGF-β, RANKL and OPG were detected by ELISA, and the expressions of OPG and RANKL mRNA in periodontal tissues of rats in each group were detected by real-time fluorescent quantitative PCR(qRT-PCR). SPSS 24.0 software package was used to analyze the data.. Compared with the control group, the periodontal tissue of the model group showed periodontal membrane fiber bundle rupture, disordered arrangement, capillary expansion, proliferation, inflammatory cell infiltration and other pathological damage. Gingival index, alveolar bone resorption value, Th17/Treg ratio, serum RANKL and IL-17 levels, and periodontal RANKL mRNA level were significantly increased(P<0.05), while the levels of serum OPG, TGF-β and OPG mRNA in periodontal tissues were significantly decreased (P<0.05). Compared with the model group, the pathological damage of periodontal tissue in the low-middle-and high-dose chitosan oligosaccharide groups and metronidazole group was reduced; gingival index, alveolar bone resorption value, Th17/Treg ratio, serum RANKL and IL-17 levels, and periodontal RANKL mRNA level were significantly decreased(P<0.05), while the levels of serum OPG, TGF-β and OPG mRNA in periodontal tissues were significantly increased(P<0.05); there was a dose-dependent relationship between the chitosan oligosaccharide groups, and there was no significant difference between the high-dose chitosan oligosaccharide group and metronidazole group(P>0.05).. Chitosan oligosaccharide can promote Th17/Treg balance to return to normal, up-regulate OPG expression, down-regulate RANKL expression, inhibit alveolar bone resorption in periodontitis rats and improve their clinical symptoms.

Topics: Alveolar Bone Loss; Animals; Chitosan; Oligosaccharides; Osteoprotegerin; Periodontitis; RANK Ligand; Rats; Receptor Activator of Nuclear Factor-kappa B; T-Lymphocytes, Regulatory

MicroRNA-146a (miR-146a) is a regulator of inflammatory response. Periodontitis is a disease with immune pathophysiology of the periodontium in which the inflammation results in the destruction of the soft tissues and alveolar bone. Therefore, the aim of this study was to investigate the expressions of miR-146a, OPG, and RANKL in diseased and healthy periodontal tissues to understand whether miR-146a expression level may associate with OPG and RANKL mRNA levels and OPG/RANKL ratio after non-surgical periodontal treatment.. The levels of miR-146a, RANKL, and OPG in gingival tissues from patients with generalized periodontitis stages II and III and grades A and B (n = 15, group A), patients with generalized periodontitis stages III and IV and grade C (n = 15, group B), and healthy individuals (n = 10) were determined by real-time PCR. The associations of miR-146a expression with OPG and RANKL levels were evaluated.. The levels of miR-146a in two subgroups within periodontitis patients were significantly higher than healthy subjects (P < 0.0001). MiR-146a showed the increased level in group A of patients compared with group B (P < 0.05). Clinical parameters such as probing depth (PD) and clinical attachment loss (CAL) were significantly higher in patients than control group (P < 0.05). The levels of OPG and RANKL were increased in patients compared with healthy subjects, although the elevated levels were not statistically significant. MiR-146a was not associated with OPG and RANKL levels and OPG/RANKL ratio.. The results of this study failed to show the associations of miR-146a level with OPG and RANKL levels and OPG/RANKL ratio in periodontitis after non-surgical periodontal treatment.

Topics: Gingiva; Humans; Inflammation; MicroRNAs; Osteoprotegerin; Periodontitis; RANK Ligand

Periodontitis is a chronic disease clinically defined by loss of alveolar bone and connective tissue degeneration. Although Moringa oleifera Lam. (MO), a tree belonging to the Moringacea family, is widely used as an anti-inflammatory agent, its effect on periodontitis is still unclear. In this work, the phenol compounds in MO leaf extract (MOL) were identified by UPLC-ESI-MS/MS, and the anti-periodontitis effects and mechanism of MOL were predicted using network pharmacology and molecular docking. Moreover, the cytotoxic, antioxidant, and anti-periodontitis properties of MOL were confirmed in vivo and in vitro. In total, 88 phenolic compounds and 234 potential MOL periodontitis targets were screened, involving 2916 biological processes (BP). The p38α MAPK (MAPK14) pathway and OPG/RANKL complex were predicted to be involved in the process of molecular docking. Furthermore, experimental validation suggested that MOL significantly ameliorated inflammation and reduced alveolar bone resorption. The OPG/RANKL ratio was regulated through the inhibition of MAPK14, and the anti-periodontitis effect was realized by the antioxidant properties of MOL. Hematoxylin and eosin (H&E) staining of rat vital organs and the survival rate of RAW 264.7 cells confirmed the safety of MOL. The present study provides valuable insights into how MOL reduces inflammation and alveolar bone resorption associated with periodontitis. In conclusion, MOL safely inhibits chronic periodontitis highly likely by regulating the expression of p38α/MAPK14-OPG/RANKL. Network pharmacology coupled with experimental validation is an effective way to find new drugs in the future. DATA AVAILABILITY STATEMENT: The original data presented in the study are included in the article. Further inquiries can be directed to the corresponding authors.

Topics: Alveolar Bone Loss; Animals; Mitogen-Activated Protein Kinase 14; Molecular Docking Simulation; Moringa oleifera; Osteoprotegerin; Periodontitis; Plant Extracts; RANK Ligand; Rats; Tandem Mass Spectrometry

Nanomaterials of biomedicine and tissue engineering have been proposed for the treatment of periodontitis in recent years. This study aimed to investigate the effects of gold nanoparticles (AuNPs) combined with human β-defensin 3 (hBD3) on the repair of the alveolar bones of experimental periodontitis in rats.. A model of experimental periodontitis was established by ligation of the maxillary second molars with silk thread in rats, which were treated with or without AuNPs combined with hBD3. Micro-computerized tomography (micro-CT) scanning, enzyme-linked immunosorbent assay, and histological and immunohistochemical staining, including alkaline phosphatase (ALP), osteoprotegerin (OPG), tartrate-resistant acid phosphatase (TRAP), and receptor activator of NF-κB ligand (RANKL), were used to analyze the samples.. Micro-CT demonstrated that the alveolar bone resorption was significantly reduced after the treatment with AuNPs combined with hBD3. Levels of TNF-α and IL-6 were decreased markedly compared with the ligation group. H&E and Masson staining showed that AuNPs combined with hBD3 group had less inflammatory cell infiltration, collagen fibrosis and fracture, but higher calcification in the new bone tissue. Moreover, the administration of AuNPs combined with hBD3 increased the expression levels of ALP and OPG (related to bone formation) while decreasing the expression levels of TRAP and RANKL (related to bone resorption) expression.. AuNPs combined with hBD3 had a protective effect on the progression of experimental periodontitis in rats and played a certain role in suppressing osteoclastogenesis and alleviating the inflammatory destruction of periodontitis along with the promotion of bone repair.

Topics: Alveolar Bone Loss; Animals; beta-Defensins; Gold; Humans; Metal Nanoparticles; Osteoprotegerin; Periodontitis; Rats

During periodontitis, tooth-supporting alveolar bone is resorbed when there is an increased expression of the pro-osteolytic factor termed receptor activator of nuclear factor κB ligand (RANKL), which is responsible for osteoclast differentiation and activation. In periodontitis-affected tissues, the imbalance between T-helper type-17 (Th17) and T-regulatory (Treg) lymphocyte activity favors this RANKL overexpression. In this context, immunotherapeutic strategies aimed at modulating this Th17/Treg imbalance could eventually arrest the RANKL-mediated alveolar bone loss. Boldine has been reported to protect from pathological bone loss during rheumatoid arthritis and osteoporosis, whose pathogenesis is associated with a Th17/Treg imbalance. However, the effect of boldine on alveolar bone resorption during periodontitis has not been elucidated yet. This study aimed to determine whether boldine inhibits alveolar bone resorption by modulating the Th17/Treg imbalance during periodontitis.. Mice with ligature-induced periodontitis were orally treated with boldine (10/20/40 mg/kg) for 15 consecutive days. Non-treated periodontitis-affected mice and non-ligated mice were used as controls. Alveolar bone loss was analyzed by micro-computed tomography and scanning electron microscopy. Osteoclasts were quantified by histological identification of tartrate-resistant acid phosphatase-positive cells. Production of RANKL and its competitive antagonist osteoprotegerin (OPG) were analyzed by ELISA, quantitative polymerase chain reaction (qPCR), and immunohistochemistry. The Th17 and Treg responses were analyzed by quantifying the T-cell frequency and number by flow cytometry. Also, the expression of their signature transcription factors and cytokines were quantified by qPCR.. Boldine inhibited the alveolar bone resorption. Consistently, boldine caused a decrease in the osteoclast number and RANKL/OPG ratio in periodontal lesions. Besides, boldine reduced the Th17-lymphocyte detection and response and increased the Treg-lymphocyte detection and response in periodontitis-affected tissues.. Boldine, administered orally, inhibited the alveolar bone resorption and modulated the Th17/Treg imbalance during experimental periodontitis.

Topics: Alveolar Bone Loss; Animals; Aporphines; Bone Resorption; Mice; Osteoclasts; Osteoprotegerin; Periodontitis; RANK Ligand; T-Lymphocytes, Regulatory; X-Ray Microtomography

This study aimed to evaluate the effects of toluidine blue-mediated photodynamic therapy (TB-PDT) on the periodontitis-induced bone resorption in periodontitis in rats. Periodontal disease was induced by cotton ligature around the right second maxillary molar in 64 rats. After 4 weeks, the rats were randomly divided into four groups: sterile saline solution (control group); laser therapy (laser group); TB (100 μg/mL); TB plus laser (0.15 W/cm

Topics: Alveolar Bone Loss; Animals; Bone Resorption; Gene Expression Regulation; Male; Osteoprotegerin; Periodontitis; Photochemotherapy; RANK Ligand; Rats, Wistar; RNA, Messenger; Tolonium Chloride

Notch signalling cascade has recently been connected to alveolar bone resorption in periodontitis. Hence, the present cross-sectional study aimed to analyze the expression of Notch signalling pathway (Notch 1, Notch 2, Jagged 1, Hes 1, Hey 1) and periodontitis-related (tumor necrosis factor alpha- TNF-α, interleukin 17-IL-17, receptor activator of nuclear factor-kappa B ligand-RANKL, osteoprotegerin-OPG) molecules and correlate it with clinical parameters in aggressive (AP) and chronic (CP) periodontitis. Additionally, the aforementioned markers' expression was evaluated in periodontitis patients with different RANKL/OPG ratios.. Eighty patients were enrolled either in AP or CP group. Clinical attachment level (CAL), bleeding on probing (BOP), periodontal probing depth (PPD) and plaque index (PI) were recorded for each patient. Total RNA was extracted from gingival crevicular fluid samples. Relative gene expression of investigated markers was determined by reverse transcriptase-real-time polymerase chain reaction.. Significantly higher values of PPD were observed in AP compared to CP (P = .010). Negative correlations between OPG and CAL, and OPG and PI, were found in AP (P = .045, P = .006, respectively), while Hey 1 and PI had a positive correlation (P = .049). In multivariate linear regression analysis, OPG and Notch 2 were predictors of CAL in AP group. TNF-α and IL-17 were higher in RANKL predominant than in OPG predominant cases (P = .007, P = .001, respectively). In RANKL predominant lesions Notch 1 and Jagged 1 were down-regulated in AP compared to CP patients (P = .010, P = .025, respectively).. The present study demonstrated that changes in Notch 2 expression affected CAL in AP cases hence this molecule could be considered as a contributor to alveolar bone loss. In RANKL-activated settings, the down-regulation of Notch 1 might participate in more severe bone resorption in AP.

Topics: Bone Resorption; Cross-Sectional Studies; Gingival Crevicular Fluid; Humans; Osteoprotegerin; Periodontitis; RANK Ligand; Signal Transduction; Tumor Necrosis Factor-alpha

Periodontitis is a lifestyle-related disease that is characterized by chronic inflammation in gingival tissue. Febuxostat, a xanthine oxidase inhibitor, exerts anti-inflammatory and antioxidant effects.. The present study investigated the effects of febuxostat on periodontitis in a rat model.. Male Wistar rats were divided into 3 groups: control, periodontitis, and febuxostat-treated periodontitis groups. Periodontitis was induced by placing a ligature wire around the 2nd maxillary molar and the administration of febuxostat (5 mg/kg/day) was then initiated. After 4 weeks, alveolar bone loss was assessed by micro-computed tomography and methylene blue staining. The expression of osteoprotegerin (OPG), a bone resorption inhibitor, was detected by quantitative RT-PCR and immunological staining, and the number of osteoclasts in gingival tissue was assessed by tartrate-resistant acid phosphatase staining. The mRNA and protein expression levels of the proinflammatory cytokines, tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β), in gingival tissue were measured using quantitative RT-PCR and immunological staining. Oxidative stress in gingival tissue was evaluated by the expression of 4-hydroxy-2-nonenal (4-HNE), and 8-hydroxy-2-deoxyguanosine (8-OHdG). To clarify the systemic effects of periodontitis, blood pressure and glucose tolerance were examined.. In rats with periodontitis, alveolar bone resorption was associated with reductions in OPG and increases in osteoclast numbers. The gingival expression of TNF-α, IL-1β, 4-HNE, and 8-OHdG was up-regulated in rats with periodontitis. Febuxostat significantly reduced alveolar bone loss, proinflammatory cytokine levels, and oxidative stress. It also attenuated periodontitis-induced glucose intolerance and blood pressure elevations.. Febuxostat prevented the progression of periodontitis and associated systemic effects by inhibiting proinflammatory mediators and oxidative stress.

Topics: Alveolar Bone Loss; Animals; Anti-Inflammatory Agents; Antioxidants; Blood Glucose; Blood Pressure; Body Weight; Disease Models, Animal; Febuxostat; Gingiva; Insulin Resistance; Interleukin-1beta; Ligation; Male; Osteoclasts; Osteoprotegerin; Oxidative Stress; Periodontitis; Rats, Wistar; Tumor Necrosis Factor-alpha; X-Ray Microtomography; Xanthine Dehydrogenase

Minocycline hydrochloride (MINO) has been one of the most frequently used antibiotics in the treatment of periodontitis due to its antibacterial activity and osteogenesis effects; however, high levels of MINO administered during the treatment halt the formation of new bone. Therefore, the purpose of the present study was to prepare a MINO-microsphere/sucrose acetate isobutyrate (SAIB) hybrid depot to reduce the burst release of MINO and ensure antibacterial and osteogenesis effects of MINO in the treatment of periodontitis. Uniform microspheres, approximately 5 µm size, with a slightly rough surface and different MINO loading (10, 12, and 14%) were prepared, and the microspheres were added into SAIB, after which the burst release significantly decreased from 66.18 to 2.92%, from 71.82 to 3.82%, and from 73.35 to 4.45%, respectively, and the release from all the MINO-microspheres/SAIB hybrid depots lasted for 77 days. In addition, cytotoxicity test showed that the MINO-microsphere with 12% drug loading promoted the proliferation of osteoblasts the most and was subsequently used in vivo experiments. Moreover, in the model of ligatured-induced periodontitis in SD rats, the MINO-microsphere/SAIB hybrid depot not only significantly increased the alveolar bone height and bone volume but also reduced the inflammation of the periodontal tissue. Additionally, it also inhibited the expression of the receptor activator of nuclear factor-kappa B ligand (RANKL) and promoted the expression of osteoprotegerin (OPG).. These results indicated that the MINO-microsphere/SAIB hybrid depot might be promising in the treatment of periodontitis.

Topics: Animals; Anti-Bacterial Agents; Chemistry, Pharmaceutical; Delayed-Action Preparations; Drug Implants; Drug Liberation; Microspheres; Minocycline; Osteoblasts; Osteogenesis; Osteoprotegerin; Periodontitis; Polylactic Acid-Polyglycolic Acid Copolymer; Rats; Rats, Sprague-Dawley; Receptor Activator of Nuclear Factor-kappa B; Sucrose

An important factor in periodontitis pathogenesis relates to a network of interactions of various cytokines. Thrombospondin-1 (TSP-1) is upregulated in several inflammatory diseases. We previously found that Porphyromonas gingivalis lipopolysaccharide (P. gingivalis LPS)-induced TSP-1 production, and that TSP-1 simultaneously and effectively elevated inflammatory cytokines in THP-1 macrophages. This suggests that TSP-1 plays an important role in the pathology of periodontitis. However, the function of TSP-1 on oral cells is largely unknown. This study aimed to elucidate the underlying molecular mechanisms of TSP-1 in human periodontal fibroblasts (hPDLFs). We demonstrated that TSP-1 is highly expressed in the gingival crevicular fluid of patients with chronic periodontitis and in the inflammatory gingival tissues of rats. TSP-1 overexpression or treatment with recombinant human TSP-1(rTSP-1) promoted the expression of MMP-2, MMP-9 and RANKL/OPG in hPDLFs, while anti-TSP-1 inhibited cytokines production from P. gingivalis LPS-treated hPDLFs. Additional experiments showed that SB203580 (a special p38MAPK inhibitor) inhibited MMP-2, MMP-9 and RANKL/OPG expression induced by rTSP-1. Thus, TSP-1 effectively promoted P. gingivalis LPS-induced periodontal tissue (extracellular matrix (ECM) and alveolar bone) destruction by the p38MAPK signalling pathway, indicating that it may be a potential therapeutic target against periodontitis.

Topics: Alveolar Bone Loss; Animals; Cytokines; Disease Models, Animal; Extracellular Matrix; Fibroblasts; Gingiva; Gingival Crevicular Fluid; Humans; Male; MAP Kinase Signaling System; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Osteoprotegerin; Periodontitis; Primary Cell Culture; RANK Ligand; Rats, Sprague-Dawley; Recombinant Proteins; Thrombospondin 1; Up-Regulation

Strontium ranelate is a medication indicated for the treatment of osteoporosis that presents concomitant anti-resorptive and osteoanabolic dual biological activity. However, the effects of strontium ranelate on alveolar bone have been poorly explored. Furthermore, to date, there are no data on the effects of this medication on alveolar bone loss (BL) during conditions of estrogen deficiency. Therefore, the aim of this study was to evaluate the effects of strontium ranelate on ligature-induced periodontitis in estrogen-deficient and estrogen-sufficient rats.. Ninety-six rats were assigned to one of the following groups: sham-surgery + water (estrogen-sufficient; n = 24); ovariectomy + water (estrogen-deficient; n = 24), sham-surgery + strontium ranelate (ranelate/estrogen-sufficient; n = 24) and; ovariectomy + strontium ranelate (ranelate/estrogen-deficient; n = 24). The rats received strontium ranelate or water from the 14th day after ovariectomy until the end of the experiment. On the 21st day after ovariectomy, one first mandibular molar received a ligature, while the contralateral tooth was left unligated. Eight rats per group were killed at 10, 20, and 30 days after ligature placement. Bone loss (BL) and trabecular bone area (TBA) were analyzed in the furcation area of ligated and unligated teeth at all experimental times by histometry. Tartrate-resistant acid phosphatase (TRAP) positive cells and immunohistochemical staining for osteocalcin (OCN), osteopontin (OPN), osteoprotegerin (OPG), and receptor activator of NF-КB ligand (RANKL) were assessed in the ligated teeth at 30 days after ligature placement.. At 10 and 30 days, ligated teeth of the estrogen-deficient group exhibited higher BL, when compared to all other groups (P < .05). At 10 days, TBAs were higher in the unligated teeth of strontium ranelate-treated groups, when compared to those of untreated groups (P < .05). At 30 days, the ligated teeth of the estrogen-deficient group exhibited lower TBA than the other groups (P < .05). There were no differences among groups regarding the number of TRAP-stained cells (P < .05). The strontium ranelate-treated groups exhibited lower expressions of OCN and RANKL than the untreated groups (P < .05). The estrogen-sufficient group presented higher staining for OPG than both treated and untreated estrogen-deficient groups (P < .05).. Strontium ranelate prevented ligature-induced BL in an estrogen-deficiency condition and, to a certain extent, increased TBA in the presence and absence of periodontal collapse in states of estrogen deficiency and estrogen sufficiency. Furthermore, strontium ranelate also affected the expression of bone markers, appearing to have acted predominantly as an anti-resorptive agent.

Topics: Alveolar Bone Loss; Animals; Estrogens; Osteocalcin; Osteopontin; Osteoprotegerin; Ovariectomy; Periodontitis; RANK Ligand; Rats; Rats, Wistar; Thiophenes

This study aims to investigate the levels of SLIT3 in gingival crevicular fluid (GCF) of healthy and periodontal disease subjects, and their correlations to periodontal disease. A total of 45 periodontal patients and 45 periodontally healthy volunteers were enrolled. The clinical parameters, radiographic bone loss and the levels of SLIT3, receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) in GCF were measured. The prevalences of Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia in subgingival plaque were also analyzed. The expression of SLIT3 and RANKL was detected in the periodontium of experimental periodontitis in rats and lipopolysaccharide (LPS)-induced mouse macrophage. The total amounts and concentrations of SLIT3 and RANKL were significantly higher in periodontitis than those in healthy, while the level of OPG was significantly lower (p < .05). Significant positive correlations were observed between the level of GCF SLIT3 and clinical attachment level and radiographic bone loss (p < .05). There existed a significant positive correlation between SLIT3 and RANKL (p < .05). Increased expression of SLIT3 and RANKL was observed in the periodontium of periodontal rats. SLIT3 expression was induced by LPS stimulation in macrophages. These results suggest that SLIT3 may act as a diagnostic indicator of periodontal disease and should be further investigated.

Topics: Adult; Animals; Dental Plaque; Female; Gingival Crevicular Fluid; Humans; Male; Membrane Proteins; Mice; Osteoprotegerin; Periodontitis; Periodontium; Porphyromonas gingivalis; RANK Ligand; Rats; Rats, Sprague-Dawley; RAW 264.7 Cells; Tannerella forsythia; Treponema denticola

Both substance P and hypoxia-inducible factor 1 alpha (HIF-1α) are involved in inflammation and angiogenesis. However, the relationship between substance P and HIF-1α in rat periodontitis is still unknown.. Ligation-induced rat periodontitis was established to observe the distribution and expression of substance P and HIF-1α by immunohistochemistry. Rat gingival fibroblasts were cultured and stimulated with Porphyromonas gingivalis lipopolysaccharide (LPS). Recombinant substance P was applied to elaborate the relationship between substance P and HIF-1α in gingival fibroblasts in vitro. Primary mouse bone marrow-derived macrophages (BMMs) were isolated and cultured to observe the effect of substance P on receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis by TRAP staining. Western blotting was used to investigate the expression of HIF-1α, osteoprotegerin (OPG) and RANKL.. Rat experimental periodontitis was successfully established 6 weeks after ligation. Gingival inflammatory infiltration and alveolar bone loss were observed. Positive expression of substance P was found in the infiltrating cells. Higher HIF-1α levels were observed in periodontitis compared to that of normal tissues. Substance P upregulated the level of HIF-1α in gingival fibroblasts with or without 1 μg/ml LPS in vitro (*P < 0.05). Substance P upregulated the expression of HIF-1α in RANKL-stimulated BMMs in vitro. Substance P also increased the RANKL/OPG ratio in gingival fibroblasts (*P < 0.05). Both 10 nM and 50 nM substance P promoted RANKL-induced osteoclast differentiation (*P < 0.05).. Substance P participates in periodontitis by upregulating HIF-1α and the RANKL/OPG ratio.

Topics: Animals; Gene Expression Regulation; Gingiva; Hypoxia-Inducible Factor 1, alpha Subunit; Male; Mice; Osteoclasts; Osteoprotegerin; Periodontitis; Porphyromonas gingivalis; RANK Ligand; Rats; Rats, Wistar; Substance P; Up-Regulation

Periodontitis is the chronic destructive disease of the periodontium, which causes severe inflammation in the tissues. Cinnamic acid as an unsaturated carboxylic acid might prevent inflammation and periodontal destruction. The present study aimed to evaluate the effects of cinnamic acid in two different forms as free cinnamic acid and cinnamic acid liposome on experimental periodontitis in Wistar rats.. Thirty-two female rats were used in the present study. Four main groups were created as follows: C: control group; P: periodontitis group; C-P: free cinnamic acid-administered periodontitis group; and CL-P: cinnamic acid liposome applied group. Periodontitis was induced via ligating 4-0 silk sutures around lower first molar teeth on both right and left mandibles. The study duration was 30 days, and the ligatures were removed from half of the rats in the periodontitis-induced groups. The other half carried the ligatures throughout 30 days, and all rats were euthanized at 30th day. Mandibles were removed and evaluated via stereomicroscope and underwent histological procedures. Inflammatory cell counts, osteoblast, and osteoclast cell counts were determined in hematoxylin-eosin-stained slides, and peroxisome proliferator-activated receptor (PPAR)-γ, cyclooxygenase (COX)-2, receptor activator of nuclear factor κ-B (RANKL), and osteoprotegerin (OPG) expressions were evaluated by immunohistochemistry.. Control group had the lowest bone loss, and periodontitis group which kept ligatures had the highest bone loss compared to the other groups. Ligature removal provided significant improvement in bone measurements. Cinnamic acid groups also showed lower bone loss compared to the periodontitis group. The inflammatory cell and osteoclast counts were also higher in the periodontitis group, and both applications of cinnamic acid decreased these values. Osteoblast cells were the lowest in the periodontitis group, and cinnamic acid increased these counts. PPAR-γ and COX-2 levels were higher in the periodontitis group, and cinnamic acid decreased these levels but not to a significant level except for the cinnamic acid liposome ligature removal group, which had significantly lower values in the PPAR-γ and COX-2. OPG levels were lower in the periodontitis group compared to the other groups. Cinnamic acid significantly decreased RANKL and increased OPG levels.. Periodontitis caused increased inflammation and bone destruction accompanied by increased PPAR-γ, COX-2, and RANKL levels and osteoclast counts. Cinnamic acid decreased osteoclast counts and inflammation and increased osteoblast counts and OPG expression in the present animal model of periodontitis.

Topics: Alveolar Bone Loss; Animals; Anti-Inflammatory Agents; Cinnamates; Female; Inflammation; Osteoclasts; Osteoprotegerin; Periodontitis; RANK Ligand; Rats; Rats, Wistar

Many species of theBauhinia genus have been widely used in folk medicine as analgesic, anti-inflammatory and antioxidant agents. (-)-Fisetinidol palmitate is a semi-syntetic flavonoid obtained from the ethanolic extract of the stem of Bauhinia pulchella. This study aimed to evaluate the antiresorptive effect of the semi-syntetic (-)-fisetinidol palmitate in ligature-induced periodontitis in rats. Also, it evaluated the mechanism of action of (-)-fisetinidol palmitate and its toxicity.. Periodontitis was inducedvia a nylon thread ligature (3.0) around the second upper left molars. Rats were treated (oral gavage) once a day for 11 days with (-)-fisetinidol palmitate (0.01 or 0.1 mg/kg) or saline vehicle.. (-)-Fisetinidol palmitate (0.1 mg/kg) reduced alveolar bone loss, increased bone alkaline phosphatase (BALP), superoxide dismutase (SOD), and catalase (CAT) activity; also, it decreased IL1-β, IL-8/CINC-1, nitrite/nitrate levels and myeloperoxidase activity. (-)-Fisetinidol palmitate reduced the mRNA levels of IL1-β, IL-6, RANK, and RANK-L, while it increased the OPG ones. No statistical differences (P > 0.05) were observed in the transaminases (ALT, AST) and Total Alkaline Phosphatase (TALP) levels among groups.. Fisetinidol palmitate did not result in any signs of toxicity and had anti-resorptive effects in a pre-clinical trial of periodontitis, showing antioxidant activity with the involvement of the RANK/RANKL/OPG pathway.

Topics: Alveolar Bone Loss; Animals; Antioxidants; Bauhinia; Cytokines; Flavonoids; Osteolysis; Osteoprotegerin; Oxidative Stress; Periodontitis; Phytochemicals; Plant Stems; RANK Ligand; Rats; Rats, Wistar

The genus Uncaria (Rubiaceae) has several biological properties significant to human health. However, the mechanisms underlying the protective effect of this plant on bone diseases are uncertain.. The present study investigated the role of Uncaria tomentosa extract (UTE) on alveolar bone loss in rats and on osteoclastogenesis in vitro.. UTE was characterized by an Acquity UPLC (Waters) system, coupled to an Electrospray Ionization (ESI) interface and Quadrupole/Flight Time (QTOF, Waters) Mass Spectrometry system (MS). The effect of UTE treatment for 11 days on the ligature-induced bone loss was assessed focusing on several aspects: macroscopic and histological analysis of bone loss, neutrophil and osteoclast infiltration, and anabolic effect. The effect of UTE on bone marrow cell differentiation to osteoclasts was assessed in vitro.. The analysis of UTE by UPLC-ESI-QTOF-MS/MS identified 24 compounds, among pentacyclic or tetracyclic oxindole alkaloids and phenols. The administration of UTE for 11 days on ligature-induced rat attenuated the periodontal attachment loss and alveolar bone resorption. It also diminished neutrophil migration to the gingiva tissue, demonstrated by a lower level of MPO. UTE treatment also decreased the level of RANKL/OPG ratio, the main osteoclast differentiation-related genes, followed by reduced TRAP-positive cell number lining the alveolar bone. Additionally, the level of bone-specific alkaline phosphatase, an anabolic bone marker, was elevated in the plasma of UTE treated rats. Next, we determined a possible direct effect of UTE on osteoclast differentiation in vitro. The incubation of primary osteoclast with UTE decreased RANKL-induced osteoclast differentiation without affecting cell viability. This effect was supported by downregulation of the nuclear factor activated T-cells, cytoplasmic 1 expression, a master regulator of osteoclast differentiation, and other osteoclast-specific activity markers, such as cathepsin K and TRAP.. UTE exhibited an effective anti-resorptive and anabolic effects, which highlight it as a potential natural product for the treatment of certain osteolytic diseases, such as periodontitis.

Topics: Alveolar Bone Loss; Animals; Bone Density Conservation Agents; Bone Marrow Cells; Bone Resorption; Cat's Claw; Cell Differentiation; Cell Survival; Chromatography, High Pressure Liquid; Down-Regulation; Male; Mice, Inbred C57BL; Osteoclasts; Osteogenesis; Osteoprotegerin; Periodontitis; Plant Extracts; RANK Ligand; Rats, Wistar; Tandem Mass Spectrometry

Biomarkers represent promising aids in periodontitis, host-mediate diseases of the tooth-supporting tissues. We assessed the diagnostic potential of matrix metalloproteinase-8 (MMP-8), tartrate-resistant acid phosphatase-5 (TRAP-5), and osteoprotegerin (OPG) to discriminate between healthy patients', mild and severe periodontitis sites. Thirty-one otherwise healthy volunteers with and without periodontal disease were enrolled at the Faculty of Dentistry, University of Chile. Periodontal parameters were examined and gingival crevicular fluid was sampled from mild periodontitis sites (M;

Topics: Adult; Biomarkers; Chronic Periodontitis; Diagnosis, Differential; Female; Gingival Crevicular Fluid; Humans; Male; Matrix Metalloproteinase 8; Middle Aged; Osteoprotegerin; Periodontitis; Severity of Illness Index; Tartrate-Resistant Acid Phosphatase

Mesenchymal stem cell therapy brings hope for regenerating damaged periodontal tissues. The present study aimed to investigate the therapeutic role of local bone marrow stem cell (BMSC) injection in ligation-induced periodontitis and the underlying mechanisms. Alveolar bone lesion was induced by placing ligatures subgingivally around the bilateral maxillary second molars for 28 days. The alveolar bone lesion was confirmed by micro-CT analysis and bone histomorphometry. Allogeneic BMSC transplantation was carried out at 28 day after ligation. The survival state of the transplanted BMSC was observed by bioluminescent imaging. The implantation of the BMSC into the gingival tissues and periodontal ligament was confirmed by green fluorescent protein (GFP) immunohistochemical staining. The expression level of pro-inflammatory, tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), and receptor activator of nuclear factor-κ B ligand (RANKL) and osteoprotegerin (OPG) in periodontal tissues were evaluated by immunohistochemical staining and real-time PCR. Significant reverse of alveolar bone lesion was observed after BMSC transplantation. The expression of TNF-α and IL-1β was down-regulated by BMSC transplantation. The number of tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts in the periodontal ligament was reduced, and the increased RANKL expression and decreased OPG expression were also reversed after BMSC transplantation. It is concluded that allogeneic BMSC local injection could inhibit the inflammation of the periodontitis tissue and promote periodontal tissue regeneration.

Topics: Alveolar Bone Loss; Animals; Bone Marrow; Disease Models, Animal; Humans; Osteoprotegerin; Periodontitis; RANK Ligand; Rats; Stem Cells

To monitor early periodontal disease progression and to investigate clinical and molecular profile of inflamed sites by means of crevicular fluid and gingival biopsy analysis.. Eighty-one samples of twenty-seven periodontitis subjects and periodontally healthy individuals were collected for the study. Measurements of clinical parameters were recorded at day -15, baseline and 2 months after basic periodontal treatment aiming at monitoring early variations ofthe clinical attachment level. Saliva, crevicular fluid and gingival biopsies were harvested from clinically inflamed and non-inflamed sites from periodontal patients and from control sites of healthy patients for the assessment of IL-10, MMP-8, VEGF, RANKL, OPG and TGF-β1 protein and gene expression levels.. Baseline IL-10 protein levels from inflamed sites were higher in comparison to both non-inflamed and control sites (p<0.05). Higher expression of mRNA for IL-10, RANK-L, OPG, e TGF-β1 were also observed in inflamed sites at day -15 prior treatment (p<0.05). After the periodontal treatment and the resolution of inflammation, seventeen percent of evaluated sites still showed clinically detectable attachment loss without significant differences in the molecular profile.. Clinical attachment loss is a negative event that may occur even after successful basic periodontal therapy, but it is small and limited to a small percentage of sites. Elevated inflammation markers of inflamed sites from disease patients reduced to the mean levels of those observed in healthy subjects after successful basic periodontal therapy. Significantly elevated both gene and protein levels of IL-10 in inflamed sites prior treatment confirms its modulatory role in the disease status.

Topics: Adult; Biomarkers; Biopsy; Case-Control Studies; Cytokines; Female; Gingiva; Gingival Crevicular Fluid; Humans; Male; Matrix Metalloproteinase 8; Middle Aged; Osteoprotegerin; Periodontal Attachment Loss; Periodontitis; Real-Time Polymerase Chain Reaction; Saliva; Statistics, Nonparametric; Time Factors; Vascular Endothelial Growth Factor A

IMD-0354 is a novel I kappa-B kinase (IKK) inhibitor, which regulates inflammation. The purpose of this study was to examine the effect of the reagent on bone loss for ligature-induced periodontitis.. We ligated around the upper right second molars of 8-week-old C57BL/6J mice in the split-mouth model. The test mice were injected intraperitoneally with IMD-0354 before the placement of the ligature. The control mice were injected intraperitoneally with 0.5% carboxymethylcellulose (CMC) as vehicle before the placement of the ligature. To determine the optimum concentration of the reagent on ligature-induced periodontitis in the mice, we examined the effect of three types of concentration, which were 1, 5, and 10 mg/kg of IMD-0354, as a preliminary experiment. After we determined 10 mg/kg as the optimum concentration for the IMD group by micro-CT analysis, both the IMD and CMC groups (n = 15 each in total, including all the analyses) were subdivided into two small groups, respectively, for further analyses: I group (unligated side of IMD group), IL group (ligated side of IMD group), C group (unligated side of CMC group) and CL group (ligated side of CMC group). The mice in the IMD and CMC groups were treated with each reagent daily and sacrificed 8 days after the ligation. For assessment of bone resorption, we performed micro-CT and histological analyses. We also carried out real-time PCR to investigate proinflammatory and bone metabolic markers.. There were significant differences for linear bone loss and volumetric parameter in the test (IMD) group compared to the control (CMC) group 8 days after ligation. In terms of the mRNA expression level of gingival tissue, the level of RANKL was significantly suppressed in the IMD group compared to the CMC group. IMD-0354 also tended to suppress the levels of interleukin-1 beta, tumor necrosis factor-alpha, and osteoprotegerin. For histological analysis, the relative numbers of TRAP-positive multinucleated cells decreased significantly in the IMD group compared to the CMC group.. IMD-0354 regulated bone resorption by ligature-induced periodontitis, and it is suggested that the inhibition of IKK via down-regulation of NF kappa-B may provide periodontal patients with an effective approach to prevent or suppress the disease.

Topics: Alveolar Bone Loss; Animals; Benzamides; Disease Models, Animal; Dose-Response Relationship, Drug; Enzyme Inhibitors; Gene Expression; Gingiva; I-kappa B Kinase; Injections, Intraperitoneal; Interleukin-1beta; Ligation; Mice, Inbred C57BL; Osteoprotegerin; Periodontitis; RANK Ligand; RNA, Messenger; Tumor Necrosis Factor-alpha; X-Ray Microtomography

The aim of this study was to evaluate the levels of salivary biomarkers IL-1β, IL-10, RANK, OPG, MMP-2, TG-β and TNF-α in individuals with diagnosis of peri-implant mucositis in the absence or presence of periodontal and peri-implant maintenance therapy (TMPP) over 5 years.. Eighty individuals diagnosed with peri-implant mucositis were divided into two groups: one group that underwent periodontal and peri-implant regularly maintenance therapy, called GTP (n=39), and a second group that received no regular maintenance GNTP (n=41). Each participant underwent a complete periodontal and peri-implant clinical examination. Collection of saliva samples and radiographic examination to evaluate peri-implant bone levels were conducted at two times: initial examination (T1) and after 5 years (T2). The salivary samples were evaluated through ELISA for the following markers: IL-1β, IL-10, RANK, OPG, MMP-2, TGF and TNF-α.. A higher incidence of peri-implantitis was observed in the GNTP group (43.9%) than in the GTP group (18%) (p=0.000). All individuals (n=12) who presented peri-implant mucositis and had resolution at T2 were in the GTP group. After 5 years, there was an increase in the incidence of periodontitis in the GNTP group compared to the GTP group (p=0.001). The results of the study revealed an increase in the salivary concentration of TNF-α in the GNTP group compared to the GTP group. The other salivary biomarkers that were evaluated did not show statistically significant differences between the two groups.. The salivary concentration of TNF-α was increased in individuals with worse periodontal and peri-implant clinical condition and in those with a higher incidence of peri-implantitis, especially in the GNTP group. Longitudinal studies in larger populations are needed to confirm these findings and elucidate the role of this biomarker in peri-implant disease.

Topics: Biomarkers; Case-Control Studies; Cytokines; Dental Implants; Disease Progression; Enzyme-Linked Immunosorbent Assay; Follow-Up Studies; Humans; Osteoprotegerin; Periodontitis; Receptor Activator of Nuclear Factor-kappa B; Reference Values; Risk Factors; Saliva; Statistics, Nonparametric; Stomatitis

Although the immunomodulatory properties of calcitriol in bone metabolism have been documented for decades, its therapeutic role in the management of periodontitis remains largely unexplored. In this study, we hypothesized that calcitriol suppresses lipopolysaccharide (LPS)-induced alveolar bone loss by regulating T helper (Th) cell subset polarization.. To test this hypothesis, we determined the effect of calcitriol intervention on the development of LPS-induced periodontitis in rats in terms of bone loss (micro-CT analysis), local inflammatory infiltration levels, the number of osteoclasts (hematoxylin and eosin staining) and the level of osteoclastogenesis (tartrate-resistant acid phosphatase method). Furthermore, immunohistochemistry was used to assess the expression levels of the receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) as well as the cytokine levels of interferon-γ (IFN-γ), interleukin-4 (IL-4), IL-17, and IL-10 throughout the LPS-injected region. Finally, the polarization potential of Th cells in peripheral blood was analyzed using flow cytometry.. Calcitriol intervention decreased alveolar bone loss in response to LPS injection and inflammatory cell infiltration. Analysis of osteoclast number and RANKL and OPG expression showed that bone resorption activity was largely suppressed in response to calcitriol administration, along with decreased IL-17 levels but increased IL-4 and IL-10 levels in periodontal tissues (the LPS-injected region). Similarly, the percentages of Th2 and Treg cells in peripheral blood increased, but the percentages of Th1 and Th17 cells decreased in rats receiving calcitriol.. Our findings suggest that calcitriol can be used to inhibit bone loss in experimental periodontitis, likely via the regulation of local and systemic Th cell polarization.

Topics: Alveolar Bone Loss; Animals; Calcitriol; Cytokines; Lipopolysaccharides; Male; Osteoclasts; Osteogenesis; Osteoprotegerin; Periodontitis; RANK Ligand; Rats; Rats, Sprague-Dawley; T-Lymphocytes, Helper-Inducer

Periodontal disease is the chronic infectious disease of the periodontium. Because of irreversibility, prevention of disease is one of the most important goals of periodontal treatment. The aim of this study was to evaluate the effect of luteolin, a powerful anti-inflammatory agent, on the prevention of experimental periodontitis by determining morphological and histological tissue alterations.. This study consisted of 28 rats and four experimental groups: healthy control group (C, n = 6); periodontitis group (P, n = 6); periodontitis and 50 mg/kg luteolin administered group (L-50, n = 8); and periodontitis and 100 mg/kg luteolin administered group (L-100, n = 8). Experimental periodontitis was induced via ligature method around lower right first molar teeth. All rats were euthanized 11 days after. The severity of periodontal destruction was determined by measuring alveolar bone loss under a stereomicroscope. Osteoblast and inflammatory cell counts were counted on hematoxylin-eosin-stained slides and osteoclasts were counted on tartrate-resistant acid phosphatase-stained slides. The levels of inducible nitric oxide synthase (iNOS), bone morphogenetic protein (BMP)-2, matrix metalloproteinase (MMP)-8, tissue inhibitor of MMP (TIMP)-1, receptor activator of nuclear factor κB ligand (RANKL), and osteoprotegerin (OPG) were determined by immunohistochemistry.. The highest alveolar bone loss was observed in the periodontitis group and the luteolin administration decreased bone loss in both groups. Osteoblast cell number was higher and osteoclast and inflammatory cell numbers were lower in the P group compared to C, L-50, and L-100 groups. Luteolin, dose-dependently increased osteoblast cell counts. Luteolin attenuated periodontal inflammation in both L-50 and L-100 groups. Like osteoblast cell numbers, BMP-2 expressions were also elevated in luteolin groups. Both doses of luteolin significantly increased TIMP-1 and BMP-2 expressions and decreased MMP-8 levels. iNOS expressions increased in P group and L-100 significantly decreased iNOS levels. RANKL increased and OPG decreased in P group and 100 mg/kg luteolin increased OPG and decreased RANKL levels significantly.. Within the limits of present experimental study, luteolin successfully improved periodontal health in a ligature-induced experimental periodontitis model in Wistar rats. The decrease in inflammation, osteoclastic and collagenase activity and increase in osteoblastic activity are possibly involved in this process.

Topics: Alveolar Bone Loss; Animals; Luteolin; Osteoclasts; Osteoprotegerin; Periodontitis; RANK Ligand; Rats; Rats, Wistar

Topics: Acute Disease; Adult; Bone Remodeling; Chronic Disease; Female; Hemorrhage; Humans; Male; Middle Aged; Osteoprotegerin; Periodontitis; RANK Ligand; Saliva; Up-Regulation; Young Adult

Peri-implantitis and periodontitis are different entities in immune characteristics even though they share similar features in clinical and radiologic signs. Toll-like receptor 2 (TLR-2), one of the key pathogen-recognition receptors in the innate immune system, plays an important role in the progression of periodontitis. However, the role of TLR-2 in peri-implantitis remains unclear. The objective of this study was to investigate the role of TLR-2 in inflammation and alveolar bone loss in a murine model of ligature-induced peri-implantitis and to compare it with ligature-induced periodontitis.. Smooth-surface titanium implants were placed in the alveolar bone of the left maxillary molars of wild-type (WT) and Tlr2 knockout (Tlr2-KO) mice 6 weeks after tooth extraction. Silk ligatures were applied to the left implant fixtures and the right maxillary second molars to induce peri-implantitis and periodontitis 4 weeks after implant placement. Two weeks after ligation, bone loss around the implants and maxillary second molars was analysed by micro-computed tomography (micro-CT), and inflammation around the implants and maxillary second molars was assessed at the same time point using histology and TRAP staining, respectively. Expression of mRNA for proinflammatory cytokines (interleukin-1β [Il1β], tumor necrosis factor-α [Tnfα]), an anti-inflammatory cytokine (interleukin-10 [Il10]) and osteoclastogenesis-related cytokines (Rankl, osteoprotegerin [Opg]) were evaluated, in gingival tissue, using real-time quantitative PCR (RT-qPCR).. The success rate of implant osseointegration was significantly higher in Tlr2-KO mice (85.71%) compared with WT mice (53.66%) (P = .0125). Micro-CT revealed significantly decreased bone loss in Tlr2-KO mice compared with WT mice (P = .0094) in peri-implantitis. The levels of mRNA for Il1β (P = .0055), Tnfα (P = .01) and Il10 (P = .0019) in gingiva were significantly elevated in the peri-implantitis tissues of WT mice, but not in Tlr2-KO mice, compared with controls. However, the gingival mRNA ratios of Rankl/Opg in peri-implant tissues were significantly upregulated in both WT (P = .0488) and Tlr2-KO (P = .0314) mice. Ligature-induced periodontitis exhibited similar patterns of bone loss and inflammatory cytokine profile in both groups of mice, except that the level of Il10 was elevated (P = .0114) whereas the Rankl/Opg ratio was not elevated (P = .9755) in Tlr2-KO mice compared with control mice. Histological findings showed increased numbers of TRAP-positive cells and infiltrated inflammatory cells in ligature-induced peri-implantitis in both WT (P < .01) and Tlr2-KO mice (P < .05), and the numbers of both types of cell were significantly higher in WT mice than in Tlr2-KO mice (P < .01).. This study suggests that TLR-2 mediates bone loss in both peri-implantitis and periodontitis. However, different molecular features may exist in the pathogenesis of the two diseases.

Topics: Alveolar Bone Loss; Animals; Cytokines; Dental Implants; Disease Models, Animal; Mice, Knockout; Osseointegration; Osteoprotegerin; Peri-Implantitis; Periodontitis; RANK Ligand; RNA, Messenger; Toll-Like Receptor 2

This study assessed the influence of obesity on the progression of ligature-induced periodontitis in rats.. Forty-eight adult Wistar rats were randomly divided into two groups: the HL group (n = 24) was fed high-fat animal food to induce obesity, and the NL group (n = 24) was fed normolipidic animal food. Obesity was induced within a period of 120 days, and the induction of experimental periodontitis (EP) was subsequently performed for 30 days. The animals were euthanized after 7, 15, and 30 days, and the jaws were removed for histopathological, histometric, and immunohistochemical analyses. Tartrate-resistant acid phosphatase (TRAP), receptor activator of nuclear factor kappa beta ligand (RANKL), and osteoprotegerin (OPG) were analyzed via immunolabeling.. Histological findings indicated that the inflammation was more extensive and lasted longer in the HL⁄EP; however, advanced destruction also occurred in the NL/EP. Greater bone loss was verified in the HL/EP group (2.28 ± 0.35) in the period of 7 days than in the NL/EP group (1.2 ± 0.29). High immunolabeling was identified in the HL/EP group in the initial periods for RANKL and TRAP, whereas the NL⁄EP group presented with moderate immunolabeling for both factors. The HL/EP and NL/EP groups showed low immunolabeling for OPG.. Obesity induced by a high-fat diet influenced alveolar bone metabolism when associated with experimental periodontitis and caused a more severe local inflammatory response and alveolar bone loss.. Obesity is related to greater alveolar bone loss and an accentuated local inflammatory response, which may be reflected in the clinical severity of periodontitis and dental loss.

Topics: Alveolar Bone Loss; Animals; Immunohistochemistry; Male; Obesity; Osteoprotegerin; Periodontitis; Random Allocation; RANK Ligand; Rats; Rats, Wistar; Tartrate-Resistant Acid Phosphatase

Periodontitis, an infective disease caused by oral pathogens and the intrinsic aging process, results in the destruction of periodontal tissues and the loss of alveolar bone. This study investigated whether

Topics: Alveolar Bone Loss; Animals; Cathepsin K; Collagen Type I; Collagen Type I, alpha 1 Chain; Gingiva; Inflammation; Interleukin-1beta; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 8; Models, Animal; NF-kappa B; Osteoporosis; Osteoprotegerin; Periodontal Diseases; Periodontitis; Plant Extracts; Proto-Oncogene Proteins c-fos; RANK Ligand; Rats; Rats, Inbred F344; RNA, Messenger; Tartrate-Resistant Acid Phosphatase; Transcription Factors; X-Ray Microtomography; Zingiberaceae

Periodontitis (PD) is an inflammatory disease characterized by gingival inflammation and resorption of alveolar bone. Impaired receptor activator of nuclear factor-kappa B ligand/osteoprotegerin (RANKL/OPG) signaling caused by enhanced production of pro-inflammatory cytokines plays an essential role in the pathogenesis of PD. Considering melatonin possesses significant anti-inflammatory property, this study aimed to determine whether prophylactic treatment with melatonin would effectively normalize RANKL/OPG signaling, depress toll-like receptor 4/myeloid differentiation factor 88 (TLR4/MyD88)-mediated pro-inflammatory cytokine activation, and successfully suppress the pathogenesis of PD. PD was induced in adult rats by placing the ligature at molar subgingival regions. Fourteen days before PD induction, 10, 50, or 100 mg/kg of melatonin was intraperitoneally injected for consecutive 28 days. Biochemical and enzyme-linked immunosorbent assay were used to detect TLR4/MyD88 activity, RANKL, OPG, interleukin 1β, interleukin 6, and tumor necrosis factor-α levels, respectively. The extent of bone loss, bone mineral intensity, and calcium intensity was further evaluated by scanning electron microscopy, micro-computed tomography, and energy-dispersive X-ray spectroscopy. Results indicated that high RANKL/OPG ratio, TLR4/MyD88 activity, and pro-inflammatory cytokine levels were detected following PD. Impaired biochemical findings paralleled well with severe bone loss and reduced calcium intensity. However, in rats pretreated with melatonin, all above parameters were successfully returned to nearly normal levels with maximal change observed in rats receiving 100 mg/kg. As prophylactic treatment with melatonin effectively normalizes RANKL/OPG signaling by depressing TLR4/MyD88-mediated pro-inflammatory cytokine production, dietary supplement with melatonin may serve as an advanced strategy to strengthen oral health to counteract PD-induced destructive damage.

Topics: Animals; Antioxidants; Male; Melatonin; Myeloid Differentiation Factor 88; Osteoprotegerin; Periodontitis; Pre-Exposure Prophylaxis; RANK Ligand; Rats; Rats, Wistar; Signal Transduction; Toll-Like Receptor 4

The aim of the study was to investigate the effects of colchicine on cytokine production, apoptosis, alveolar bone loss, and oxidative stress in an experimental model of periodontitis in rats.. Forty-eight rats were divided equally into four groups: healthy (H); periodontitis (P); periodontitis+colchicine low dose (CL, 30 μg/kg/day), and periodontitis+colchicine high dose (CH, 100 μg/kg/day). After 11 days, interleukin (IL) -1β, IL-8, and IL-10 were analyzed in gingival samples using Enzyme-Linked ImmunoSorbent Assay. Receptor activator of nuclear factor kappa-B ligand (RANKL), osteoprotegerin (OPG), total oxidative stress (TOS), total antioxidant status (TAS), and oxidative stress index (OSI) were measured in gingiva and serum. Alveolar bone volume was evaluated via micro-CT. Apoptotic cells were detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay in histological sections.. Colchicine treatment significantly reduced IL-1β, IL-8, RANKL, RANKL/OPG, TOS, OSI, and bone volume ratio levels, and increased TAS levels compared to group P (p < 0.05). High dose colchicine treatment (CH) significantly decreased TUNEL+ cell counts compared to group P (p < 0.05).. These finding suggest that colchicine has a prophylactic potential for the prevention of periodontal tissue destruction through anti-inflammatory, anti-oxidative, anti-apoptotic, and bone-protective effects.

Topics: Alveolar Bone Loss; Animals; Apoptosis; Colchicine; Inflammation; Osteoprotegerin; Periodontitis; RANK Ligand; Rats; Rats, Wistar

Curcumin exhibits anti-inflammatory effects and has been suggested as a treatment for inflammatory diseases. The aim of this study was to investigate the effects of curcumin on the lipopolysaccharide induced inflammatory response in rat gingival fibroblasts in vitro and ligation-induced experimental periodontitis in vivo, and to speculate the possible anti-inflammatory mechanism of curcumin.. The gingival fibroblasts were incubated with different concentrations of curcumin in the absence or presence of lipopolysaccharide (LPS). Concentrations of interleukin-1β(IL-1β), tumor necrosis factor-α (TNF-α), osteoprotegerin (OPG) and soluble receptor activator of nuclear factor kappa-B ligand (RANKL) culture supernatants of rat gingival fibroblasts were determined by enzyme linked immunosorbent assay. The nuclear fraction of rat gingival fibroblasts was extracted and nuclear factor kappa-B (NF-κB) activation was assessed by western blotting to elucidate related mechanisms. Curcumin was given every two days by oral gavage. The gingival inflammation and alveolar bone loss between the first and second molars were observed by hematoxylin and eosin staining. Collagen fibers were observed by picro-sirius red staining. Alveolar bone loss was assessed by micro-CT analysis.. Curcumin attenuated the production of IL-1β and TNF-α in rat gingival fibroblasts stimulated by LPS, and inhibited the LPS-induced decrease in OPG/sRANKL ratio and NF-κB activation. Curcumin significantly reduced gingival inflammation and modulated collagen fiber and alveolar bone loss in vivo.. curcumin modulates inflammatory activity in rat periodontitis by inhibiting NF-κB activation and decreasing the OPG/sRANKL ratio induced by LPS.

Topics: Animals; Cells, Cultured; Curcumin; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Fibroblasts; Gingiva; Interleukin-1beta; Male; Osteoprotegerin; Periodontitis; Random Allocation; Rats; Rats, Wistar; Reference Values; Sensitivity and Specificity; Tumor Necrosis Factor-alpha; X-Ray Microtomography

Topics: Acetylation; Butyrates; Cell Line; Dental Pulp Cavity; Gene Expression Regulation; Histones; Humans; Isoprostanes; Osteoblasts; Osteoprotegerin; Periodontitis; RANK Ligand

This study assessed the effect of curcumin as a photosensitizer in antimicrobial photodynamic therapy (aPDT) for the treatment of induced periodontitis in rats. Periodontitis was induced via a ligature around the mandibular first molar on the left side of 96 rats. The ligature was removed 7 days later, and the animals were randomized into four groups: NT, no local treatment; CUR, irrigation with curcumin solution (40 μM); LED, irradiation with a light-emitting diode (LED, InGaN, 465-485 nm, 200 mW/cm

Topics: Animals; Curcumin; Inflammation; Male; Mandible; Molar; Osteoprotegerin; Periodontitis; Photochemotherapy; Proliferating Cell Nuclear Antigen; RANK Ligand; Rats, Wistar; Tartrate-Resistant Acid Phosphatase

Intermittent administration of parathyroid hormone (PTH) has been demonstrated to have anabolic effects on bone metabolism and is approved for use in the treatment of osteoporosis. This study evaluates the role of intermittent PTH administration on alveolar bone loss in streptozotocin (STZ)-induced diabetic rats.. Fifty male Sprague Dawley rats were randomly divided into the following five groups: (1) a control group (saline placebo without ligature and STZ injection), (2) a PTH group (PTH administration without ligature and STZ injection), (3) an L group (saline placebo with ligature), (4) an L+STZ group (saline placebo with ligature and STZ injection), and (5) an L+STZ+PTH group (PTH administration with ligature and STZ injection). PTH was administered at 75μg/kg per dose four times a week for 28days. Subsequently, all rats were sacrificed, and their mandibles were extracted for micro-computed tomography (micro-CT) scanning, as well as histological and immunochemical evaluation.. Micro-CT scanning demonstrated the anabolic effect of PTH on alveolar bone metabolism in STZ-induced diabetic rats (P<0.05), and histomorphometry indicated that PTH inhibited inflammation of the periodontium and increased the level of osteoblastic activity (P<0.05). Immunochemical evaluation showed that rats subjected to both ligature placement and STZ injection had the highest receptor activator of nuclear factor kappa B ligand (RANKL)/osteoprotegerin (OPG) ratio and that PTH administration decreased this ratio.. Intermittent systemic PTH administration effectively reduced alveolar bone loss and ameliorated the manifestation of experimental periodontitis in STZ-induced diabetic rats.

Topics: Alveolar Bone Loss; Animals; Diabetes Mellitus, Experimental; Male; Maxilla; Osteoblasts; Osteoclasts; Osteoprotegerin; Parathyroid Hormone; Periodontitis; RANK Ligand; Rats; Rats, Sprague-Dawley; Streptozocin; X-Ray Microtomography

The aim of this study is to investigate effects of strontium ranelate (SR) on alveolar bone loss (ABL) in rats with experimental periodontitis.. Forty Wistar rats were randomly divided into five groups: 1) control (n = 8); 2) ligated (n = 8); 3) 300 mg/kg SR (SR300, n = 8); 4) 625 mg/kg SR (SR625, n = 8); and 5) 900 mg/kg SR (SR900, n = 8). To create experimental periodontitis, 4/0 silk ligatures were inserted submarginally around first molars at the right mandible. After 11 days, rats were sacrificed. ABL was calculated by measuring cemento-enamel junction and alveolar crest distance. Interleukin (IL)-1β, osteoprotegerin (OPG), and bone-specific alkaline phosphatase (BALP) serum levels were determined by enzyme-linked immunosorbent assay. Histopathologic analysis was used to evaluate inflammatory cell infiltration, numbers of osteoblasts and osteoclasts, and receptor activator of nuclear factor-kappa B ligand (RANKL) activity.. ABL was significantly lower in SR900 group than in the ligated group (P <0.05). Osteoclast numbers in ligated group were significantly higher than in the control, SR300, and SR900 groups (P <0.05). In ligated, SR625, and SR900 groups, significantly higher osteoblast numbers were detected than in control group (P <0.05). Osteoblast numbers in SR625 group were significantly higher than in the SR300 group (P <0.05). RANKL activities in SR900 and control groups were close to each other (P >0.05). Serum IL-1β, OPG, and BALP levels revealed no significant difference (P >0.05).. It can be concluded that SR can reduce RANKL activity and osteoclast numbers, as well as ABL.

Topics: Alkaline Phosphatase; Alveolar Bone Loss; Animals; Biomarkers; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Interleukin-1beta; Male; Osteoclasts; Osteoprotegerin; Periodontitis; Random Allocation; RANK Ligand; Rats; Rats, Wistar; Thiophenes

It is recognized that orthodontic force (OF) has an aggravating effect on the progression of destructive periodontitis if periodontitis have not been well controlled. However, the underlying mechanism is not completely clear. This study was to investigate the effect of antibiotic administration on OF-aggravated, ligature-induced experimental periodontitis in mice.. C57BL/6 mice (male, 8 wk old) were divided into three groups (n = 8). Silk ligatures (SL) were tied around the maxillary right (group 1) or both (groups 2 and 3) first molars on day 0, removed on day 8 and systemic antibiotics was administered through drinking water (group 3) since day 8. OF was applied on the maxillary right first molars since day 13 (groups 2 and 3). All mice were killed on day 20.. Total oral bacteria load was significantly higher in group 2 when compared to group 1 on day 20, whereas such count was greatly reduced in group 3 when antibiotics were administered. Periodontal bone loss was significantly increased on SL side vs. control side in group 1. Periodontal bone loss was significantly increased on OF + SL side vs. SL side in group 2 (p < 0.05) but not in group 3 when systemic antibiotics were administered. Gingival mRNA and protein expressions of receptor activator of nuclear factor kappa-B ligand/osteoprotegerin were significantly increased on OF + SL side vs. SL side in group 2 (p < 0.01) but not in group 3. However, comparable levels of tartrate-resistant acid phosphatase-positive cell formation within periodontal space and tooth movement were observed on OF + SL side in groups 2 and 3.. Our results suggest that reduction of oral bacterial load by antibiotic administration alleviate orthodontic force-aggravated periodontitis bone loss.

Topics: Alveolar Bone Loss; Animals; Anti-Bacterial Agents; Biomarkers; Disease Models, Animal; Disease Progression; Enzyme-Linked Immunosorbent Assay; Immunoglobulin G; Ligation; Male; Maxilla; Mice; Mice, Inbred C57BL; Osteoclasts; Osteoprotegerin; Periodontitis; Real-Time Polymerase Chain Reaction; Receptor Activator of Nuclear Factor-kappa B; RNA, Messenger; Tartrate-Resistant Acid Phosphatase; Tooth Movement Techniques

A dual relationship between glycemic status and bone remodeling was suggested recently. The present study aimed to 1) analyze salivary levels of receptor activator for nuclear factor κ-B ligand (RANKL), osteoprotegerin, osteocalcin, and osteopontin as potential biomarkers of alveolar bone loss and 2) determine whether the glycemic status affects the relationship between bone remodeling markers and periodontal status.. Salivary levels of RANKL, osteoprotegerin, osteocalcin, osteopontin, and serum glycosylated hemoglobin A1c, insulin, and glucose were analyzed in 220 participants divided into four groups according to their periodontal health status: 1) 79 participants had at least 14 teeth with probing depth (PD) ≥4 mm (generalized periodontitis [GP]); 2) 65 participants had either two or seven teeth with PD ≥4 mm (two groups of localized periodontitis [LP1 and LP2, respectively]); and 3) 76 participants had no teeth with PD ≥4 mm (non-periodontitis control group).. Salivary concentrations of RANKL, osteocalcin, and osteopontin were higher, and osteoprotegerin was lower in females than in males. Salivary osteoprotegerin concentrations were higher in the GP and LP2 groups than in the control group, whereas RANKL, osteocalcin, and osteopontin were not related with periodontal status. Salivary osteopontin correlated positively with serum and salivary insulin. The association observed between increased osteoprotegerin concentrations and periodontitis was lost after salivary insulin was included into the analyses as a confounding factor.. Salivary concentrations of bone markers are either affected by glycemic status or detected at very low levels. These factors hinder their use as salivary biomarkers of periodontitis.

Topics: Alveolar Bone Loss; Bone Remodeling; Female; Humans; Male; Osteocalcin; Osteoprotegerin; Periodontitis; RANK Ligand

This study aimed to assess the effect of multiple sessions of a low-level laser therapy (LLLT) adjuvant to scaling and root planing (SRP) on the treatment of experimental periodontitis (EP) in rats treated with 5-fluorouracil (5-FU).. A total of 120 rats were divided into five groups: no treatment (NT); treatment with 5-FU (60 and 40 mg/kg) and no local periodontal treatment (5FU); treatment with 5-FU and SRP (5FU-SRP); treatment with 5-FU, SRP and one LLLT session (660 nm; 0.035 W; 4.2 J; 120 s) (5FU-SRP-1LLLT); and treatment with 5-FU, SRP and four LLLT sessions (0, 24, 48 and 72 h) (5FU-SRP-4LLLT). EP was induced in the mandibular molars through ligature placement. The alveolar bone loss (ABL) area in the furcation region was analysed histometrically. TRAP, proliferating cell nuclear antigen, RANKL, osteoprotegerin and activated caspase-3 patterns were analysed by immunolabeling. Prostaglandin E2 was quantified using an ELISA, and tumour necrosis factor α and interleukin-6 were assessed using the multiplex method. The prevalence rates of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella nigrescens, Prevotella intermedia and Fusobacterium nucleatum were assessed using the PCR method. The data were subjected to statistical analysis (α = 5%).. 5FU, 5FU-SRP and 5FU-SRP-1LLLT treatment groups showed higher ABL compared with the NT group (p < 0.05), whereas the 5FU-SRP-4LLLT group showed lower ABL compared with the 5FU group on day 7 and decreased RANKL immunolabeling (p < 0.05).. Treatment with 5-FU worsened EP, and multiple LLLT sessions adjuvant to SRP seemed to improve periodontitis in rats subjected to 5-FU chemotherapy.

Topics: Alveolar Bone Loss; Animals; Bacteria; Caspase 3; Combined Modality Therapy; Dental Scaling; Dinoprostone; Drug Therapy; Fluorouracil; Inflammation; Interleukin-6; Low-Level Light Therapy; Male; Mandible; Molar; Osteoprotegerin; Periodontitis; RANK Ligand; Rats; Rats, Wistar; Root Planing; Tumor Necrosis Factor-alpha

Matricaria recutita L. (chamomile) has demonstrated anti-inflammatory activity. Accordingly, the ability of the Matricaria recutita extract (MRE) to inhibit proinflammatory cytokines and its influence on alveolar bone resorption (ABR) in rats.. Wistar rats were subjected to ABR by ligature with nylon thread in the second upper-left molar, with contralateral hemiarcade as control. Rats received polysorbate TW80 (vehicle) or MRE (10, 30, and 90 mg/kg) 1 hour before ligature and daily until day 11. The periodontium was analyzed by macroscopy, histometry, histopathology, and immunohistochemistry for the receptor activator of nuclear factor-kappa B ligand (RANKL), osteoprotegerin (OPG), and tartrate-resistant acid phosphatase (TRAP). The gingival tissue was used to quantify the myeloperoxidase (MPO) activity and tumor necrosis factor (TNF)-α and interleukin (IL)-1β levels by enzyme-linked immunosorbent assay. Blood samples were collected to evaluate bone-specific alkaline phosphatase (BALP), leukogram, and dosages of aspartate and alanine transaminases, urea, and creatinine. Aspects of liver, kidneys, spleen, and body mass variations were also evaluated.. The 11 days of ligature induced bone resorption, low levels of BALP, leukocyte infiltration; increase of MPO, TNF-α, and IL-1β; immunostaining increase for RANKL and TRAP; reduction of OPG and leukocytosis, which were significantly prevented by MRE, except for the low levels of BALP and the leukocytosis. Additionally, MRE did not alter organs or body weights of rats.. MRE prevented the inflammation and ABR by reducing TNF-α and IL-1β, preventing the osteoclast activation via the RANKL-OPG axis, without interfering with bone anabolism.

Topics: Alveolar Bone Loss; Animals; Bone Resorption; Chamomile; Interleukin-1beta; Matricaria; Osteoclasts; Osteoprotegerin; Periodontitis; Plant Extracts; RANK Ligand; Rats; Rats, Wistar; Tumor Necrosis Factor-alpha

The purposes of this study were to evaluate, in rats: i) the effects of Bacillus species on the development of experimental periodontitis (EP) via microtomographic, immunological and hematological assays (Experiment 1-E1); ii) the effects of Bacillus species as adjuncts to scaling and root planing (SRP) for the treatment of EP via histomorphometric and immunohistochemical analyses (Experiment 2-E2).. In E1, 24 rats were divided into groups C1 (control), PROB1, EP1 and EP-PROB1. In groups with EP, the mandibular first molar of each animal received a ligature for 14 days. In groups PROB1, animals received Bacillus species for 44 days, starting 30 days before EP induction in Group EP-PROB1. In E2, 24 rats were assigned to groups C2 (control), PROB2, EP-SRP2 and EP-SRP-PROB2. In groups with SRP, EP was induced as described in E1. The ligatures were removed after 14 days and SRP was performed. In groups PROB2, animals received Bacillus species for 15 days, starting after SRP in Group EP-SRP-PROB2.. In E1, Group EP1 presented bone loss (BL) and eosinophil numbers greater than Group EP-PROB1 (P<0.05). In Group EP-PROB1, the receptor activator of nuclear factor-kB ligand (RANKL)/osteoprotegerin (OPG) ratio was similar to that of groups without EP. In E2, Group EP-SRP-PROB2 presented fewer TRAP-positive osteoclasts, lower immunolabeling pattern for a proinflammatory cytokine and decreased BL and attachment loss than Group EP-SRP2 (P<0.05).. Bacillus species supplementation provided a protective effect against BL and enhanced the effects of SRP in the treatment of EP in rats.

Topics: Alveolar Bone Loss; Animals; Bacillus licheniformis; Bacillus subtilis; Dental Scaling; Immunohistochemistry; Male; Molar; Osteoclasts; Osteoprotegerin; Periodontitis; Probiotics; Random Allocation; Rats; Rats, Wistar; Root Planing; X-Ray Microtomography

The aim of this study was to evaluate the effects of systemic fucoxanthin treatment on alveolar bone resorption in rats with periodontitis. Thirty rats were divided into control, experimental periodontitis (EP), and experimental periodontitis-fucoxanthin (EP-FUCO) groups. Periodontitis was induced by ligature for four weeks. After removal of the ligature, the rats in the EP-FUCO group were treated with a single dose of fucoxanthin (200 mg/kg bw) per day for 28 consecutive days. At the end of the study, all of the rats were euthanized and intracardiac blood and mandible tissue samples were obtained for biochemical, immunohistochemical, and histometric analyses. Fucoxanthin treatment resulted in a slight decrease in tumor necrosis factor-α, interleukin-1β, and interleukin-6 levels and a significant decrease in oxidative stress index. It was observed that fucoxanthin caused a significant reduction in receptor activator of nuclear factor kappa-β ligand (RANKL) levels and a statistically non-significant elevation in osteoprotegerin and bone-alkaline phosphatase levels. There were no significant differences in alveolar bone loss levels between the EP and EP-FUCO groups. This experimental study revealed that fucoxanthin provides a limited reduction in alveolar bone resorption in rats with periodontitis. One of the mechanisms underlying the mentioned limited effect might be related to the ability of fucoxanthin to inhibit oxidative stress-related RANKL-mediated osteoclastogenesis.

Topics: Alveolar Bone Loss; Animals; Bone and Bones; Interleukin-1beta; Interleukin-6; Male; Molar; Osteoclasts; Osteoprotegerin; Oxidative Stress; Periodontitis; Phosphoric Monoester Hydrolases; RANK Ligand; Rats; Rats, Sprague-Dawley; Tumor Necrosis Factor-alpha; Xanthophylls

To study the expression and possible role of OPG/RANK/RANKLin the rat dental pulp of periodontitis combined with vascular calcification.. Thirty-six male Wister rats were randomly divided into 4 groups: control group(group C), periodontitis group(group CP), vascular calcification group(group VDN) and compound group(group CP+VDN). Each group underwent corresponding management to establish animal model. When the model was successful, the maxillae including molars were sectioned, pulp tissue was examined by H-E staining; Immunohistochemical staining method was used to evaluate the expression and ratio of OPG and RANKL in pulp tissues. Statistical analysis was carried out using SPSS 19.0 software package.. The pulp tissue of group CP, VDN, CP+VDN showed varied degrees of damage, neutrophil infiltration, pulp vascular congestion, odontoblasts vacuolar changes, pulp necrosis by H-E staining, and the changes in CP+VDN group was the most significant, followed by CP group, VDN group. Immunohistochemistry showed OPG in pulp tissues in group CP, VDN, CP+VDN were significantly lower than that in normal group (P<0.05), and the expression in group CP+VDN was the least;Expression of RANKL in pulp tissues in group CP, VDN, CP+VDN were significantly higher than that in normal group(P<0.05)，and the expression in group CP+VDN was the highest. The ratio of OPG/RANKL in normal group was the highest, and the ratio in CP+VDN group was the lowest.. Periodontitis and vascular calcification can damage the pulp tissue, periodontitis compound with vascular calcification may aggravate the injury; OPG/RANKL/RANK system may play an important role in pulp tissue injury.

Topics: Animals; Dental Pulp; Disease Models, Animal; Immunohistochemistry; Inflammation; Male; Molar; Osteoprotegerin; Periodontitis; RANK Ligand; Rats; Rats, Wistar; Vascular Calcification

The objective of this study was to investigate the effects of osteoprotegerin (OPG) gene therapy on alveolar bone resorption caused by experimental periodontitis in rats, thus forming a foundation for potential clinical applications of OPG gene therapy in the treatment of periodontitis and peri-implantitis.. To study the effects of OPG on alveolar bone protection, an experimental periodontitis model was used by placing a bacterial plaque retentive silk ligature in the gingival sulcus around the maxillary second molar tooth, injection of Porphyromonas gingivalis and high carbohydrate diet. A total of 30 Sprague-Dawley rats were randomly divided into three groups, with 10 rats in each group: group I (control) was treated with 10 μL normal saline injection; group II with 10 μL mock vector; and group III with 10 μL local OPG gene transfer by transfection with in vitro constructed pcDNA3.1-human OPG (pcDNA3.1-hOPG). A subperiosteal injection was done adjacent to the second molars on days 0, 7, 14 and 21. Four weeks later, all animals were killed and radiographic, histological and immunohistochemical examinations were performed. Statistical analysis included ANOVA and LSD-Bonferroni test.. Group III (OPG gene therapy) had significantly enhanced (p < 0.05) integrated optical density of OPG, had significantly decreased alveolar bone resorption volume and active osteoclast number (p < 0.05) through descriptive histological examination when compared with the other two groups at week 4.. Local recombinant OPG plasmid-mediated gene therapy suppresses osteoclastogenesis in vivo and inhibits alveolar bone height reduction caused by experimental periodontitis in rats. OPG gene therapy may be beneficial in preventing progressive periodontal bone loss.

Topics: Alveolar Bone Loss; Animals; Cell Line; Female; Gene Transfer Techniques; Genetic Therapy; Genetic Vectors; Humans; Microscopy, Electron, Scanning; Myoblasts; Osteoclasts; Osteoprotegerin; Periodontitis; Plasmids; Porphyromonas gingivalis; Random Allocation; Rats; Rats, Sprague-Dawley; Transfection

Interleukin-33 (IL-33) controls T-helper type 2 (Th2) cytokines and the development of mast cells. This study aimed to investigate the expression of IL-33 and its association with RANKL and osteoprotegerin (OPG) in periodontal health and experimental periodontitis.. Eighteen Wistar rats were assigned to two study groups of nine animals each: ligature only (LO) and nonligated (NL). Silk sutures were placed subgingivally, surrounding the right lower first molars. The animals were killed on day 11 after ligature placement, and the alveolar bone loss at the first molars was determined histometrically. Periodontal tissues were examined histopathologically to evaluate the differences between the groups. The expression of IL-33, RANKL and OPG was detected immunohistochemically.. The LO group showed significantly greater alveolar bone loss compared with the NL group (p < 0.05). The numbers of osteoclasts, osteoblasts and inflammatory cells were significantly higher in the LO group compared with the NL group (p < 0.05). Osteoblastic activity was significantly lower in the LO group than in the NL group (p < 0.05). There was significantly higher expression of IL-33 and RANKL and a greater number of OPG-positive cells in the LO group (p < 0.05). IL-33 expression showed a positive correlation with RANKL expression and with the number of mast cells (p < 0.05).. The experimental periodontitis group exhibited increased expression of IL-33 and RANKL compared with the healthy group. Additionally, there was a positive correlation between these expressions. According to these results, IL-33 could be associated with the pathogenesis of periodontal disease.

Topics: Alveolar Bone Loss; Animals; Cell Count; Inflammation; Interleukin-33; Mast Cells; Osteoblasts; Osteoclasts; Osteogenesis; Osteoprotegerin; Periodontitis; RANK Ligand; Rats; Rats, Wistar; Sutures

Acupuncture has shown the capability of modulating the immuno-inflammatory response of the host. This study aims to evaluate the effects of electroacupuncture (EA) on ligature-induced periodontitis in rats.. Thirty-two animals were divided into four groups: 1) control; 2) experimental periodontitis (EP); 3) sham-treated (EP/EA-sham); and 4) treated with EA (EP/EA). For the EP groups, a ligature was placed around the right mandibular first molars at day 1. Sessions of EA or EA-sham were assigned every other day. For EA treatment, large intestine meridian points LI4 and LI11 and stomach meridian points ST36 and ST44 were used. EA-sham was performed in off-meridian points. Animals were euthanized at day 11. Histomorphometric and microtomographic analyses were performed. Immunolabeling patterns for the receptor activator of nuclear factor κB ligand (RANKL), osteoprotegerin (OPG), and tartrate-resistant acid phosphatase (TRAP) were assessed. Expressions of interleukin (IL)-1β, matrix metalloproteinase (MMP)-8, IL-6, and cyclooxygenase (COX)-2 messenger RNAs (mRNAs) were evaluated by quantitative reverse transcription-polymerase chain reaction. Data were analyzed statistically (P <0.05, analysis of variance).. Histomorphometric and microtomographic analyses demonstrated that group EP/EA presented reduced alveolar bone loss when compared to group EP (P <0.05). Reduced RANKL immunolabeling and fewer TRAP-positive multinucleated cells were observed in the EA-treated group in relation to group EP. No differences were observed in OPG expression among groups. EA treatment decreased the genic expression of IL-1β and MMP-8 (P <0.05), increased the mRNA expression of IL-6 (P <0.05), and did not modify the genic expression of COX-2 in animals with EP (P >0.05).. It can be concluded that EA reduced periodontal tissue breakdown and the expression of some proinflammatory mediators and a proresorptive factor in EP in rats.

Topics: Acid Phosphatase; Acupuncture Points; Alveolar Bone Loss; Animals; Bone Density; Cyclooxygenase 2; Electroacupuncture; Giant Cells; Image Processing, Computer-Assisted; Interleukin-1beta; Interleukin-6; Isoenzymes; Male; Matrix Metalloproteinase 8; Osteoprotegerin; Periodontal Ligament; Periodontitis; Rats; Rats, Wistar; Receptor Activator of Nuclear Factor-kappa B; Tartrate-Resistant Acid Phosphatase; X-Ray Microtomography

Periodontitis and osteoporosis are bone destructive diseases with a high prevalence in the adult population. The concomitant presence of osteoporosis may be a risk factor of progression of periodontal destruction. We studied the effect of sclerostin-neutralizing monoclonal antibody (Scl-Ab) on alveolar bone endpoints in an ovariectomized (OVX) rat model of induced experimental periodontitis.. Sixty female, 4-month-old Sprague-Dawley rats underwent sham operation or bilateral OVX and were left untreated for 2 months. Experimental periodontitis (ligature) was established by placing silk sutures subgingival to the right maxillary first and second molar teeth for 4 weeks, and feeding the rats food and high-sugar drinking water during this period. Thereafter, ligatures were removed and 25mg/kg vehicle or Scl-Ab was administered subcutaneously twice weekly for 6 weeks. Rats were randomized into four groups: (1) Control (Sham+Vehicle), (2) Sham+Ligature+Vehicle, (3) OVX+Ligature+Vehicle, and (4) OVX + Ligature + Scl-Ab. Terminal blood and right maxilla specimens were collected for analyses.. Group 3 rats showed lower bone volume fraction (BVF) of alveolar bone with higher bone resorption and lower bone formation than Group 2 rats. Group 4 rats had higher alveolar crest height, as assessed by linear distance of cementoenamel junction to the alveolar bone crest and greater alveolar bone mass using Micro CT, than Group 3 rats. Significantly higher values of mineral apposition rate (MAR) and mineralizing surface/bone surface (MS/BS) were also observed in Group 4 rats by analyzing polychrome sequential labeling data. Increased serum osteocalcin and osteoprotegerin, and deceased serum tartrate-resistant acid phosphatase and CTx-1 illustrate the ability of Scl-Ab to increase alveolar bone mass by enhancing bone formation and decreasing bone resorption in an animal model of estrogen deficiency osteopenia plus periodontitis.. Scl-Ab could be a potential bone anabolic agent for improving alveolar crest height and higher alveolar bone mass in conditions where alveolar bone loss in periodontitis is compounded by estrogen deficiency osteopenia.

Topics: Alveolar Process; Animals; Antibodies, Neutralizing; Bone Density; Bone Morphogenetic Proteins; Disease Models, Animal; Female; Genetic Markers; Osteocalcin; Osteoprotegerin; Ovariectomy; Periodontitis; Rats; Rats, Sprague-Dawley; X-Ray Microtomography

This study assesses the effects of topical sodium alendronate (SA) as an adjuvant to the mechanical treatment of ligature-induced periodontitis in rats.. Ninety animals were subjected to the induction of periodontitis via the installation of a ligature around the mandibular left first molar. After 7 days, the ligature was removed, and the animals were distributed into the following groups: 1) NT group (n = 30), no treatment; 2) SRP group (n = 30), scaling and root planing (SRP) and local irrigation with physiologic saline solution; and 3) SRP/SA group (n = 30), SRP and local irrigation with SA (10(-5) M). Ten animals from each group were euthanized at 7, 15, and 30 days after treatment. Histologic and histometric analyses were performed in the furcation region. The percentage of bone in the furcation (PBF) was measured. Immunohistochemical analyses for detecting the receptor activator of nuclear factor-κB ligand (RANKL), osteoprotegerin (OPG), tartrate-resistant acid phosphatase (TRAP), and activated caspase-3 were performed at the furcation region.. Compared with the other groups, the SRP/SA group showed less local inflammation and better tissue reparation during the entire experiment. There was more PBF in the SRP/SA group than in the other groups at days 7 and 15. Stronger OPG immunolabeling and weaker RANKL immunolabeling were observed in the SRP/SA group at 15 and 30 days. There were fewer TRAP-positive cells in the SRP/SA group than in the NT group at all of the time points. There was no difference in the number of activated caspase-3-positive osteocytes among groups and time points.. It can be concluded that topical use of SA as an adjuvant to SRP is effective in the treatment of experimental periodontitis.

Topics: Alendronate; Alveolar Process; Animals; Apoptosis; Bone Density Conservation Agents; Caspase 3; Combined Modality Therapy; Dental Scaling; Osteoclasts; Osteocytes; Osteoprotegerin; Periodontitis; RANK Ligand; Rats; Rats, Wistar; Root Planing; Tartrate-Resistant Acid Phosphatase; Therapeutic Irrigation; Time Factors

Accumulating evidence points to the importance of the innate immune system in inflammation-induced bone loss in infectious and autoimmune diseases. TLRs are well known for being activated by ligands expressed by bacteria, viruses, and fungi. Recent findings indicate that also endogenous ligands in inflammatory processes are important, one being a TLR5 agonist present in synovial fluid from patients with rheumatoid arthritis (RA). We found that activation of TLR5 by its specific ligand, flagellin, caused robust osteoclast formation and bone loss in cultured mouse neonatal parietal bones dependent on increased receptor activator of NF-κB ligand (RANKL):osteoprotegerin ratio, with half-maximal stimulation at 0.01 μg/ml. Flagellin enhanced Rankl mRNA in isolated osteoblasts by a myeloid differentiation primary response gene 88 and NF-κB-dependent mechanism. Injection of flagellin locally over skull bones in 5-wk-old mice resulted in increased mRNA expression of Rankl and osteoclastic genes, robust osteoclast formation, and bone loss. The effects in vitro and in vivo were absent in Tlr5(-/-) mice. These data show that TLR5 is a novel activator of RANKL and osteoclast formation and, therefore, a potential key factor in inflammation-induced bone erosions in diseases like RA, reactive arthritis, and periodontitis. TLR5 might be a promising novel treatment target for prevention of inflammatory bone loss.

Topics: Animals; Arthritis; Immunity, Innate; Mice; Mice, Knockout; Myeloid Differentiation Factor 88; NF-kappa B; Osteoblasts; Osteoclasts; Osteoprotegerin; Periodontitis; RANK Ligand; Toll-Like Receptor 5

To investigate changes in the levels and relative ratios of sclerostin, osteoprotegerin (OPG), and receptor activator of nuclear factor-κB ligand (RANKL) in the gingival crevicular fluid (GCF) of patients with periodontitis after non-surgical periodontal treatment.. Fifty-four individuals (27 healthy controls and 27 patients with chronic periodontitis [CP]) were enrolled in the study. Periodontitis patients received non-surgical periodontal therapy. GCF sampling and clinical periodontal parameters were assessed before and 6 weeks after therapy. Sclerostin, OPG, and RANKL levels were measured by enzyme-linked immunosorbent assay, and their relative ratios were calculated.. Total amounts and concentrations of sclerostin were significantly higher in patients with CP than in healthy individuals (P <0.025) and decreased after treatment (P <0.05). The RANKL/OPG ratio was significantly lower in healthy individuals than in patients with periodontitis before and after treatment (P <0.025), but no significant difference was observed in patients with periodontitis after treatment (P >0.05). The sclerostin/OPG and sclerostin/RANKL ratios were significantly lower in healthy individuals than in patients with periodontitis before and after treatment (P <0.025) and decreased in patients with periodontitis after treatment (P <0.05).. The GCF sclerostin level may be more reliable than the RANKL/OPG ratio as a diagnostic and prognostic marker of periodontal disease and treatment outcome. Regulation of sclerostin levels may aid the development of new therapeutic strategies for the treatment of periodontal disease.

Topics: Gingival Crevicular Fluid; Humans; Osteoprotegerin; Periodontitis; RANK Ligand

The aim of this study is to characterize and evaluate the host response caused by three different models of experimental periodontitis in mice.. C57BL/6 wild-type female mice were distributed into six experimental groups and sacrificed at 7, 15, and 30 days after the induction of periodontal disease: 1) group C: no treatment control group; 2) group L: periodontal disease induced by ligature; 3) group G-Pg: oral gavage with Porphyromonas gingivalis (Pg); 4) group G-PgFn: oral gavage with Fusobacterium nucleatum + Pg; 5) group I-Pg: heat-killed Pg injected into the palatal mucosa between the molars; and 6) group I-V: phosphate-buffered saline injected into the palatal mucosa. The samples were used to analyze the immune-inflammatory process in the gingival tissue via descriptive histologic and real-time polymerase chain reaction analyses. The alveolar bone loss was evaluated using microcomputed tomography. The data were analyzed using the Kruskal-Wallis test, followed by a post hoc Dunn test and analysis of variance, followed by a Tukey test using a 5% significance level.. Only the ligature model displayed significant alveolar bone loss in the initial period (7 days), which was maintained with time. The group injected with heat-killed Pg displayed significant alveolar bone loss starting from day 15, which continued to progress with time (P <0.05). A significant increase (P <0.05) in the gene expression of proinflammatory cytokines (interleukin-6 and -1β) and proteins involved in osteoclastogenesis (receptor activator of nuclear factor-κB ligand and osteoprotegerin) was observed in the ligature group on day 7.. The ligature and injection of heat-killed Pg models were the most representative of periodontal disease in humans, whereas the oral gavage models were not effective at inducing the disease under the experimental conditions.

Topics: Administration, Oral; Alveolar Bone Loss; Animals; Coinfection; Disease Progression; Female; Fusobacterium nucleatum; Host-Pathogen Interactions; Inflammation Mediators; Injections; Interleukin-1beta; Interleukin-6; Leukocytes; Macrophages; Mice; Mice, Inbred C57BL; Mouth Mucosa; Osteoclasts; Osteoprotegerin; Periodontal Attachment Loss; Periodontitis; Porphyromonas gingivalis; Random Allocation; RANK Ligand; Time Factors; X-Ray Microtomography

T-helper type 17 (Th17) cells produce interleukin-17 (IL-17) and help to protect against inflammation and infection in periodontal disease. Furthermore, while follicular dendritic cell-secreted protein (FDC-SP) may be involved in the inflammation of periodontal tissue, the biological role of FDP-SP in periodontal disease is still unknown. The purpose of the present study was to clarify the expression of IL-17 and FDC-SP in experimental periodontitis in rats.. Seven-week-old male Wistar rats were divided into baseline control, sham and test groups. Experimental periodontitis was induced by placing a ligature in the mesiopalatal area, and untreated rats served as a baseline control group. Morphological changes in alveolar bone were investigated 7, 14 and 28 d after treatment. Expression of the Rankl, osteoprotegerin (Opg) and Il17 genes was analyzed 5 and 7 d after the induction of experimental periodontitis.. Alveolar bone resorption progressed in the test group for 7 d, but not thereafter. At 5 d after the induction of periodontitis, the Rankl/Opg mRNA ratio and the expression of IL-17 in the test group were significantly increased compared with the respective values in the baseline control group; however, there were no significant differences between the test and control groups at 7 d. The expression of FDC-SP was significantly decreased in the test group compared with the baseline control group at 5 and 7 d after the induction of periodontitis, and this value had returned to normal levels at 14 and 28 d.. These results suggest that both IL-17 and FDC-SP could be involved in the inflammatory response, and FDC-SP in the junctional epithelium might play an important role in the Th17 cell-related immune response.

Topics: Alveolar Bone Loss; Alveolar Process; Animals; Dendritic Cells, Follicular; Disease Progression; Interleukin-17; Male; Osteoprotegerin; Periodontitis; Polymerase Chain Reaction; Proteins; RANK Ligand; Rats; Rats, Wistar; Th17 Cells; Time Factors; X-Ray Microtomography

The goal of the present study was to evaluate the effects of systemic boric acid on the levels of expression of RANKL and osteoprotegerin (OPG) and on histopathologic and histometric changes in a rat periodontitis model.. Twenty-four Wistar rats were divided into three groups of eight animals each: nonligated (NL); ligature only (LO); and ligature plus treatment with boric acid (BA) (3 mg/kg per day for 11 d). A 4/0 silk suture was placed in a subgingival position around the mandibular right first molars; after 11 d the rats were killed, and alveolar bone loss in the first molars was histometrically determined. Periodontal tissues were examined histopathologically to assess the differences among the study groups. RANKL and OPG were detected immunohistochemically.. Alveolar bone loss was significantly higher in the LO group than in the BA and NL groups (p < 0.05). The number of inflammatory infiltrate and osteoclasts in the LO group was significantly higher than that in the NL and BA groups (p < 0.05). The numbers of osteoblasts in LO and BA groups were significantly higher compared with NL group (p < 0.05). There were significantly more RANKL-positive cells in the LO group than in the BA and NL groups (p < 0.05). There was a higher number of OPG-positive cells in the BA group than in the LO and NL groups (p < 0.05).. The present study shows that systemic administration of boric acid may reduce alveolar bone loss by affecting the RANKL/OPG balance in periodontal disease in rats.

Topics: Administration, Oral; Alveolar Bone Loss; Alveolar Process; Animals; Boric Acids; Cell Count; Connective Tissue; Disease Models, Animal; Fibroblasts; Mandible; Osteoblasts; Osteoclasts; Osteoprotegerin; Periodontal Ligament; Periodontitis; RANK Ligand; Rats; Rats, Wistar

Porphyromonas gingivalis (Pg) may cause an immune-inflammatory response in host cells leading to bone degradation by osteoclasts. We investigated the osteoclast-inducing capacity of periodontal ligament fibroblasts from periodontitis patients and non-periodontitis donors after a challenge with viable Pg.. PDLFs from periodontitis patients (n = 8) and non-periodontitis donors (n = 7) were incubated for 6 h with or without viable Pg and subsequently co-cultured with osteoclast precursors from peripheral blood mononuclear cells (PBMCs). The number of multinucleated tartrate-resistant acid phosphatase-positive cells was determined at 21 days. Expression of osteoclastogenesis-associated genes was assessed after infection of PDLFs mono-cultures and in PDLFs-PBMCs co-cultures. Resorption activity was analysed on bone slices.. Pg induced the expression of osteoclastogenesis-associated genes by PDLFs. After bacterial challenge the formation of osteoclast-like cell was decreased in co-cultures of PBMCs with non-periodontitis PDLFs, but not with PDLFs from periodontitis patients.. PDLFs from sites free of periodontitis respond to an infection with Pg by tempering formation of osteoclast-like cells, probably promoting clearance of the infection. PDLFs from periodontitis sites are desensitized to a Pg challenge in terms of their osteoclast-inducing capacity.

Topics: Acid Phosphatase; Actins; Bone Resorption; Carbonic Anhydrase II; Cell Culture Techniques; Cell Differentiation; Coculture Techniques; Female; Fibroblasts; Giant Cells; Humans; Isoenzymes; Leukocytes, Mononuclear; Male; Middle Aged; Osteoclasts; Osteoprotegerin; Periodontal Ligament; Periodontitis; Porphyromonas gingivalis; RANK Ligand; Tartrate-Resistant Acid Phosphatase; Time Factors

This study evaluates the effects of probiotic therapy (PT) in rats with ligature-induced periodontitis associated with restraint stress.. Sixty-four rats were divided into control, stress (STR), probiotic (PROB), periodontal disease (PD), STR-PROB, STR-PD, STR-PROB-PD, and PROB-PD groups. The probiotic was added to the drinking water for 44 days. PD was induced by a ligature. In STR groups, the animals were subjected to restraint stress for 2.5 hours per day for 30 days.. Rats with PD exhibited increased alveolar bone loss (P <0.05), as well as increased levels of cyclooxygenase-2, serum C-terminal telopeptide (CTX), p38 mitogen-activated protein kinase (p38), and receptor activator of nuclear factor-κB ligand and decreased levels of osteoprotegerin (OPG). Stressed rats presented high levels of C-peptide, corticosterone, and glucose (P <0.05). In general, the presence of stress reduced the expression of CTX and p38 (P <0.05). PT reduced alveolar bone loss in unstressed animals. It also decreased expression of CTX and induced increased expression of OPG in unstressed animals with PD. However, PT was not effective in preventing bone loss or altering the expression of inflammatory markers in stressed animals. PT decreased the number of inflammatory cells in the periodontal tissue (P <0.05). Groups with stress and PD showed decreased villous height and crypt depth. Stress seemed to prevent part of the probiotic beneficial effects on the small intestine.. Based on the methodology used, PT may reduce tissue breakdown resulting from PD in unstressed rats. The protocol used for restraint stress influenced the immunomodulatory effects of PT in intestinal and periodontal tissues.

Topics: Alveolar Bone Loss; Animals; Blood Glucose; C-Peptide; Collagen Type I; Corticosterone; Cyclooxygenase 2; Gingivitis; Intestinal Mucosa; Intestine, Small; Male; Osteoprotegerin; p38 Mitogen-Activated Protein Kinases; Peptides; Periodontitis; Probiotics; RANK Ligand; Rats; Rats, Wistar; Stress, Physiological; Stress, Psychological

The aim of the present study was to assess the impact of chronic consumption of Cachaça on alveolar bone loss (BL) induced by ligature and on alveolar bone density (BD) in peripubertal rats.. Male Wistar rats were assigned into one of the following groups:. non-ingestion of Cachaça (n=15); Cachaça: ingestion of ascending concentrations of Cachaça during 100 days (n=15). 70th day after the beginning of Cachaça ingestion, one first mandibular molar received a ligature while the contralateral tooth was left unligated. After 30 days, the rats were killed. BL, BD, the positive cells for tartrate-resistant acid phosphatase (TRAP), receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) were analyzed in the furcation area of the ligated and unligated mandibular molars.. The Cachaça group presented greater BL (0.75±0.1mm(2) for Cachaça and 0.66±0.1mm(2) for control group, respectively) and number of RANKL and OPG+ cells and lower BD (60.3±4.2% for Cachaça and 76.8±3.8% for control group, respectively) and number of TRAP+ cells around ligated teeth (p<0.05), when compared to the control group. The Cachaça group (0.42±0.02mm(2)) also presented a higher BL around unligated teeth when compared to control group (0.31±0.05mm(2)).. Cachaça consumption per se and in the presence of ligature negatively affects alveolar bone by increasing the alveolar BL and reducing BD.

Topics: Acid Phosphatase; Alveolar Bone Loss; Animals; Bone Density; Ethanol; Isoenzymes; Ligation; Male; Mandible; Osteoprotegerin; Periodontitis; RANK Ligand; Rats; Rats, Wistar; Tartrate-Resistant Acid Phosphatase

Antimicrobial therapy can suppress periodontal pathogens and increase the effectiveness of conventional mechanical treatment. The aim of this study was to assess bone loss and the immune inflammatory response of rats under the influence of two photosensitizing agents (MB and TBO) at two different concentrations in antimicrobial photodynamic therapy (aPDT), used as an adjuvant therapy in the treatment of periodontitis.. Periodontitis was induced in the mandibular first molars of 162 rats. The animals were divided into nine groups: G1 - scaling and root planing (SRP); G2 - SRP plus 100 μg/mL of methylene blue (MB); G3 - SRP plus 10 mg/mL of MB; G4 - SRP plus 100 μg/mL of toluidine blue (TBO); G5 - SRP plus 10 mg/mL of TBO; G6 - SRP plus 100 μg/mL of MB and laser; G7 - SRP plus 10 mg/mL of MB and laser; G8 - SRP plus 100 μg/mL of TBO and laser; and G9 - SRP plus 10 mg/mL of TBO and laser. Six animals from each group were euthanized 7, 15, or 30 d after treatment. Bone loss (BL) in the furcation region was evaluated using histomorphometric and immunohistochemical analyses to detect the receptor activator of nuclear factor-Κappa B ligand (RANKL), osteoprotegerin (OPG) and tartrate-resistant acid phosphatase (TRAP).. There was significantly less BL in animals treated with aPDT using low concentrations of MB and TBO at 7, 15 and 30 d. Immunohistochemical analysis revealed decreased RANKL and increased OPG in the aPDT groups and decreased TRAP-positive cells in G6 and G8.. aPDT, using low concentrations of MB and TBO, was the most effective adjuvant therapy to SRP, acting indirectly as a downregulator of the molecular mechanisms that control bone resorption in periodontitis.

Topics: Acid Phosphatase; Alveolar Bone Loss; Animals; Combined Modality Therapy; Connective Tissue; Dental Scaling; Isoenzymes; Low-Level Light Therapy; Lymphocytes; Male; Methylene Blue; Neutrophils; Osteoclasts; Osteoprotegerin; Periodontitis; Phenothiazines; Photochemotherapy; Photosensitizing Agents; RANK Ligand; Rats; Rats, Wistar; Root Planing; Tartrate-Resistant Acid Phosphatase; Time Factors; Tolonium Chloride

There is evidence that histamine released during inflammation plays a role in bone metabolism via the H2 receptor, stimulating bone resorption. The purpose of this study is to evaluate whether cimetidine, a histamine H2-receptor antagonist, interferes with the initiation and progression of induced periodontal disease in rat molars.. Forty male rats received 100 mg/kg body weight of cimetidine (cimetidine group [CimG]) or saline solution (sham group [SG]). Periodontal disease was induced in the maxillary left first molars (PDSG and PDCimG); maxillary right molars were used as non-ligature controls. After 7, 15, 30, and 50 days, maxillary fragments were embedded in paraffin. The sections were stained with Masson trichrome and hematoxylin and eosin and subjected to the tartrate-resistant acid phosphatase (TRAP) method. The distances between the cemento-enamel junction (CEJ) and alveolar process (AP) crest, as well as between the CEJ and junctional epithelium (JE) level, were measured; the number of inflammatory cells was computed. Receptor activator of nuclear factor kappa B ligand (RANKL) and osteoprotegerin (OPG) immunohistochemistry was carried out, and the RANKL/OPG ratio was calculated.. In PDSG and PDCimG, a significant increase (P ≤0.05) was observed in CEJ-AP and CEJ-JE distances. However, the increases in both distances were significantly less in PDCimG compared with PDSG at 15, 30, and 50 days. Numerous TRAP-positive osteoclasts were found in the PDSG and PDCimG. In PDCimG, the volume density of inflammatory cells and the RANKL/OPG ratio were significantly lower (P ≤0.05) than in PDSG.. Cimetidine exerts a beneficial effect on periodontal disease in rats, decreasing the RANKL/OPG ratio in gingival connective tissue and reducing alveolar bone resorption.

Topics: Acid Phosphatase; Alveolar Bone Loss; Alveolar Process; Animals; Cimetidine; Coloring Agents; Connective Tissue; Disease Models, Animal; Disease Progression; Epithelial Attachment; Fibroblasts; Gingiva; Histamine H2 Antagonists; Isoenzymes; Male; Maxilla; Molar; Osteoprotegerin; Periodontitis; RANK Ligand; Rats; Rats, Sprague-Dawley; Tartrate-Resistant Acid Phosphatase; Time Factors; Tooth Cervix

The interleukin-1 receptor antagonist (IL-1Ra) binds to IL-1 receptors and inhibits IL-1 activity. However, it is not clear whether IL-1Ra plays a protective role in periodontal disease. This study was undertaken to compare experimental periodontitis induced by Aggregatibacter actinomycetemcomitans in IL-1Ra knockout (KO) mice and wild-type (WT) mice. Computed tomography (CT) analysis and hematoxylin-and-eosin (H&E) and tartrate-resistant acid phosphatase (TRAP) staining were performed. In addition, osteoblasts were isolated; the mRNA expression of relevant genes was assessed by real-time quantitative PCR (qPCR); and calcification was detected by Alizarin Red staining. Infected IL-1Ra KO mice exhibited elevated (P, <0.05) levels of antibody against A. actinomycetemcomitans, bone loss in furcation areas, and alveolar fenestrations. Moreover, protein for tumor necrosis factor alpha (TNF-α) and IL-6, mRNA for macrophage colony-stimulating factor (M-CSF), and receptor activator of NF-κB ligand (RANKL) in IL-1Ra KO mouse osteoblasts stimulated with A. actinomycetemcomitans were increased (P, <0.05) compared to in WT mice. Alkaline phosphatase (ALP), bone sialoprotein (BSP), osteocalcin (OCN)/bone gla protein (BGP), and runt-related gene 2 (Runx2) mRNA levels were decreased (P, <0.05). IL-1α mRNA expression was increased, and calcification was not observed, in IL-1 Ra KO mouse osteoblasts. In brief, IL-1Ra deficiency promoted the expression of inflammatory cytokines beyond IL-1 and altered the expression of genes involved in bone resorption in A. actinomycetemcomitans-infected osteoblasts. Alterations consistent with rapid bone loss in infected IL-Ra KO mice were also observed for genes expressed in bone formation and calcification. In short, these data suggest that IL-1Ra may serve as a potential therapeutic drug for periodontal disease.

Topics: Aggregatibacter actinomycetemcomitans; Animals; Bone Diseases, Metabolic; Bone Resorption; Gene Expression Regulation; Inflammation; Interleukin 1 Receptor Antagonist Protein; Macrophage Colony-Stimulating Factor; Mice; Mice, Knockout; Osteoprotegerin; Pasteurellaceae Infections; Periodontitis; RANK Ligand

Periodontitis is a chronic inflammatory disease accompanied by alveolar bone resorption by osteoclasts. Porphyromonas gingivalis, an etiological agent for periodontitis, produces cysteine proteases called gingipains, which are classified based on their cleavage site specificity (i.e. arginine (Rgps) and lysine (Kgps) gingipains). We previously reported that Kgp degraded osteoprotegerin (OPG), an osteoclastogenesis inhibitory factor secreted by osteoblasts, and enhanced osteoclastogenesis induced by various Toll-like receptor (TLR) ligands (Yasuhara, R., Miyamoto, Y., Takami, M., Imamura, T., Potempa, J., Yoshimura, K., and Kamijo, R. (2009) Lysine-specific gingipain promotes lipopolysaccharide- and active-vitamin D3-induced osteoclast differentiation by degrading osteoprotegerin. Biochem. J. 419, 159-166). Osteoclastogenesis is induced not only by TLR ligands but also by proinflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-17A, in inflammatory conditions, such as periodontitis. Although Kgp augmented osteoclastogenesis induced by TNF-α and IL-1β in co-cultures of mouse osteoblasts and bone marrow cells, it suppressed that induced by IL-17A. In a comparison of proteolytic degradation of these cytokines by Kgp in a cell-free system with that of OPG, TNF-α and IL-1β were less susceptible, whereas IL-17A and OPG were equally susceptible to degradation by Kgp. These results indicate that the enhancing effect of Kgp on cytokine-induced osteoclastogenesis is dependent on the difference in degradation efficiency between each cytokine and OPG. In addition, elucidation of the N-terminal amino acid sequences of OPG fragments revealed that Kgp primarily cleaved OPG in its death domain homologous region, which might prevent dimer formation of OPG required for inhibition of receptor activator of nuclear factor κB ligand. Collectively, our results suggest that degradation of OPG by Kgp is a crucial event in the development of osteoclastogenesis and bone loss in periodontitis.

Topics: Adhesins, Bacterial; Amino Acid Sequence; Animals; Animals, Outbred Strains; Bacteroidaceae Infections; Bone Marrow Cells; Cell Differentiation; Cells, Cultured; Cysteine Endopeptidases; Gingipain Cysteine Endopeptidases; Humans; Interleukin-17; Interleukin-1beta; Mice; Molecular Sequence Data; Osteoblasts; Osteoclasts; Osteoprotegerin; Periodontitis; Porphyromonas gingivalis; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Tumor Necrosis Factor-alpha

The aim of this study was to evaluate the effects of azilsartan (AZT) on bone loss, inflammation, and the expression of matrix metallo proteinases (MMPs), receptor activator of nuclear factor κB ligand (RANKL), receptor activator of nuclear factor κB (RANK), osteoprotegerin (OPG), cyclooxygenase-2 (COX-2), and cathepsin K in periodontal tissue in a rat model of ligature-induced periodontitis.. Male Wistar albino rats were randomly divided into 5 groups of 10 rats each: (1) nonligated, water; (2) ligated, water; (3) ligated, 1 mg/kg AZT; (4) ligated, 5 mg/kg AZT; and (5) ligated, 10 mg/kg AZT. All groups were treated with saline or AZT for 10 days. Periodontal tissues were analyzed by histopathology and immunohistochemical detection of MMP-2, MMP-9, COX-2, RANKL, RANK, OPG, and cathepsin K. Levels of IL-1β, IL-10, TNF-α, myeloperoxidase (MPO), and glutathione (GSH) were determined by ELISA.. Treatment with 5 mg/kg AZT resulted in reduced MPO (p<0.05) and IL-1β (p<0.05), increased levels of IL-10 (p<0.05), and reduced expression of MMP-2, MMP-9, COX-2, RANK, RANKL, cathepsin K, and increased expression of OPG.. These findings reveal that AZT increases anti-inflammatory cytokines and GSH and decreases bone loss in ligature-induced periodontitis in rats.

Topics: Animals; Benzimidazoles; Cathepsin K; Interleukin-10; Interleukin-1beta; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Osteoprotegerin; Oxadiazoles; Periodontitis; Rats; Rats, Wistar; Receptor Activator of Nuclear Factor-kappa B; Tumor Necrosis Factor-alpha

The aim of the present research was to investigate the ultrastructural aspects and the immunoexpression of receptor activator of NFκB ligand (RANKL) and osteoprotegerin (OPG) on experimental periodontal disease of alendronate (ALN)-treated rats. Male Wistar rats received daily injections of 2.5 mg/kg body weight of ALN during 7 days previously and 7, 14, and 21 days after the insertion of a 4.0 silk suture into the gingival sulcus around the right upper second molar. Specimens were fixed in 0.1% glutaraldehyde + 4% formaldehyde under microwave irradiation, decalcified in 4.13% EDTA and paraffin embedded for TRAP histochemistry and immunohistochemistry for RANKL and OPG, or embedded in Spurr epoxy resin for TEM analysis. ALN reduced the activity of osteoclasts and significantly decreased the resorption of the alveolar crest. In the control group the alveolar crest appeared resorbed by TRAP-positive osteoclasts, which presented ultrastructural features of activated cells. The immunoexpression of RANKL was not inhibited by the drug; however, the expression of OPG was increased in the treated animals. The alveolar crest of ALN-treated specimens at 21 days showed signs of osteonecrosis, like empty osteocyte lacunae, the exposed bone regions and bacterial infection. The results showed that ALN treatment in individuals with periodontal disease represents a risk of osteonecrosis because of the reduced activity of osteoclasts resultant of the increased immunoexpression of OPG.

Topics: Alendronate; Alveolar Process; Animals; Dental Papilla; Disease Progression; Gingiva; Male; Microscopy; Microscopy, Electron, Transmission; Osteoprotegerin; Periodontitis; RANK Ligand; Rats; Rats, Wistar

β-cryptoxanthin (β-cry) is a type of carotenoid found in certain fruits and vegetables. Although it has been shown that β-cry inhibits alveolar bone resorption, the molecular mechanisms for this have not yet been clarified. In the present study, we investigated the effects of β-cry on bone resorption related-cytokine production in human periodontal ligament (hPDL) cells.. hPDL cells were stimulated with β-cry (1×10(-7)mol/l), mechanical stress (1 or 6MPa), and P. gingivalis. The production of interleukin (IL)-1β, IL-6, IL-8, tumour necrosis factor (TNF)-α, osteoprotegerin (OPG), and receptor activator of nuclear factor kappa-B ligand (RANKL) were analyzed by RT-PCR and ELISA.. The production of IL-1β, IL-6, IL-8, and TNF-α was not induced in hPDL cells after stimulation with β-cry, although these cytokines were produced after stimulation with P. gingivalis. On the other hand, IL-6 and IL-8 were produced after exposure to 6MPa of mechanical stress. The production of IL-6 and IL-8 was significantly decreased by the addition of β-cry. Furthermore, β-cry up-regulated the production of OPG, but not RANKL.. β-cry inhibited the production of IL-6 and IL-8 induced by mechanical stress and periodontopathogenic bacteria in hPDL cells. Moreover, β-cry up-regulated OPG production. These results suggest that β-cry may prevent bone resorption in periodontitis.

Topics: Bacteroidaceae Infections; Bone Resorption; Cells, Cultured; Cryptoxanthins; Cytokines; Enzyme-Linked Immunosorbent Assay; Gene Expression; Humans; Osteoprotegerin; Periodontal Ligament; Periodontitis; Porphyromonas gingivalis; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Stress, Mechanical; Up-Regulation; Xanthophylls

Besides their role in bone metabolism, receptor activator of nuclear factor-kappaB ligand (RANKL) and osteoprotegerin (OPG) are also known to be associated with inflammation. We explored associations between the extent/severity of periodontitis and circulating levels of sRANKL and OPG and their ratio using a cross-sectional study design.. The extent of periodontal inflammation and tissue destruction and the serum levels of sRANKL (pg/ml) and OPG (pg/ml) were determined in 80 subjects with type 1 diabetes mellitus (T1DM). Plaque-, age-, gender-, smoking-, HbA1c- and body mass index-adjusted associations between periodontal parameters and serum sRANKL, OPG and their ratio were studied using multiple linear regression analysis.. Adjusted regression analyses of all the subjects indicated a significant positive association between AL ≥ 4 mm and severity of periodontitis and the level of serum OPG. A major drop in the strength and statistical significance of the above association was observed when the analyses included only non-smokers. Serum sRANKL level and sRANKL/OPG ratio were not associated with periodontitis.. Our observations suggest that serum OPG may be an indicator of periodontal tissue destruction in T1DM.

Topics: Adolescent; Adult; Age Factors; Aged; Alveolar Bone Loss; Body Mass Index; Cross-Sectional Studies; Dental Plaque Index; Diabetes Mellitus, Type 1; Female; Gingival Hemorrhage; Glycated Hemoglobin; Humans; Longitudinal Studies; Male; Middle Aged; Osteoprotegerin; Periodontal Attachment Loss; Periodontal Pocket; Periodontitis; RANK Ligand; Retrospective Studies; Sex Factors; Smoking; Young Adult

The objective of this study is to investigate the participation of inflammatory and oxidative stress mediators and the effects on the expression of matrix metalloproteinase (MMP)-2, MMP-9, and receptor activator of NF-κB ligand (RANKL)/receptor activator of NF-κB (RANK)/osteoprotegerin (OPG) pathway in the response to treatment with olmesartan, an angiotensin II type 1 receptor blocker. Male Wistar albino rats were randomly divided into five groups of ten rats each: (1) non-ligature with water, (2) ligature with water, (3) ligature with 1 mg/kg olmesartan, (4) ligature with 6 mg/kg olmesartan, and (5) ligature with 10 mg/kg olmesartan. All groups were treated with olmesartan or the vehicle by gavage daily for 10 days. Following the treatment course, the periodontal tissue of the animals was analyzed by histopathology and immunohistochemistry to determine the expression of cyclooxygenase-2 (COX-2), MMP-2, MMP-9, and members of the RANKL/RANK/OPG pathway and by ELISA and spectroscopic assay to determine the levels of interleukin (IL)-1β, IL-10, tumor necrosis factor (TNF)-α, myeloperoxidase (MPO), malonaldehyde (MDA), and glutathione. The concentrations of MPO and MDA were reduced in the group that received 6 mg/kg olmesartan (p < 0.05). In addition, the group that was treated with 6 mg/kg olmesartan showed a decreased level of IL-1β (p < 0.05), and all doses of olmesartan resulted in decreased levels of TNF-α. Furthermore, treatment with 6 mg/kg olmesartan led to downregulation of the expression of COX-2, MMP-2, MMP-9, RANKL, and RANK and to upregulation of the expression of OPG. These findings suggest that 6 mg/kg olmesartan reduces the inflammatory process and bone loss by downregulating MMPs and RANKL in osteoblasts and by upregulating OPG.

Topics: Alveolar Bone Loss; Animals; Anti-Inflammatory Agents; Cyclooxygenase 2; Gingiva; Imidazoles; Interleukin-1beta; Male; Malondialdehyde; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Osteoprotegerin; Periodontitis; Peroxidase; RANK Ligand; Rats; Rats, Wistar; Receptor Activator of Nuclear Factor-kappa B; Tetrazoles; Tumor Necrosis Factor-alpha

Periodontal diseases are initiated primarily by Gram-negative, tooth-associated microbial biofilms that elicit a host response that causes osseous and soft tissue destruction. Carvedilol is a β-blocker used as a multifunctional neurohormonal antagonist that has been shown to act not only as an anti-oxidant but also as an anti-inflammatory drug. This study evaluated whether Carvedilol exerted a protective role against ligature-induced periodontitis in a rat model and defined how Carvedilol affected metalloproteinases and RANKL/RANK/OPG expression in the context of bone remodeling. Rats were randomly divided into 5 groups (n = 10/group): (1) non-ligated (NL), (2) ligature-only (LO), and (3) ligature plus Carvedilol (1, 5 or 10 mg/kg daily for 10 days). Periodontal tissue was analyzed for histopathlogy and using immunohistochemical analysis characterized the expression profiles of MMP-2, MMP-9, COX-2, and RANKL/RANK/OPG and determined the presence of IL-1β, IL-10 and TNF-α, myeloperoxidase (MPO), malonaldehyde (MDA) and, glutathione (GSH). MPO activity in the group with periodontal disease was significantly increased compared to the control group (p<0.05). Rats treated with 10 mg/kg Carvedilol presented with significantly reduced MPO and MDA concentrations (p<0.05) in addition to presenting with reduced levels of the pro-inflammatory cytokines IL-1 β and TNF-α (p<0.05). IL-10 levels in Carvedilol-treated rats remained unaltered. Immunohistochemical analysis demonstrated reduced expression of MMP-2, MMP-9, RANK, RANKL, COX-2, and OPG in rats treated with 10 mg/kg Carvedilol. This study demonstrated that Carvedilol affected bone formation/destruction and anti-inflammatory activity in a rat model of periodontitis.

Topics: Animals; Carbazoles; Carvedilol; Cyclooxygenase 2; Disease Models, Animal; Interleukin-1beta; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Osteoprotegerin; Oxidative Stress; Periodontitis; Propanolamines; RANK Ligand; Rats; Tumor Necrosis Factor-alpha

The aim of this study was to evaluate the effect of telmisartan (TELM) on inflammation, oxidation and the expression of matrix metalloproteinases (MMPs) and the expression RANKL/RANK/OPG in the periodontal tissue of a rat model for ligature-induced periodontitis.. Male Wistar albino rats were randomly divided into five groups of 10 rats each: (i) non-ligated, given water; (ii) ligated, given water; (iii) ligated, given 1 mg/kg TELM; (iv) ligated, given 5 mg/kg TELM; and (v) ligated, given 10 mg/kg TELM. All groups were treated with saline or TELM for 10 days. Periodontal tissue was analysed by histopathology; by the immunohistochemical examination of COX-2, MMP-2, MMP-9 and the RANKL/RANK/OPG pathway; and by ELISA analysis of the levels of IL-1β, IL-10, TNF-α, myeloperoxidase (MPO), malonaldehyde (MDA) and glutathione (GSH).. Treatment with 10 mg/kg TELM resulted in reduced concentrations of MPO, MDA (p < 0.05) and the pro-inflammatory cytokine IL-1β (p < 0.05); reduced expression of MMP-2, MMP-9, RANK, RANKL and COX-2; and an increase in OPG. The levels of TNF-α were significantly reduced in all TELM-treated groups.. These findings confirm the involvement of TELM in reducing the inflammatory response, oxidative stress and bone loss in ligature-induced periodontitis in rats.

Topics: Alveolar Bone Loss; Animals; Anti-Inflammatory Agents; Antioxidants; Benzimidazoles; Benzoates; Cyclooxygenase 2; Disease Models, Animal; Down-Regulation; Glutathione; Interleukin-10; Interleukin-1beta; Male; Malondialdehyde; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Osteoprotegerin; Oxidative Stress; Periodontitis; Peroxidase; Random Allocation; RANK Ligand; Rats; Rats, Wistar; Receptor Activator of Nuclear Factor-kappa B; Telmisartan; Tumor Necrosis Factor-alpha

To investigate the levels of biomarkers associated with osteoclastogenesis in patients suffering peri-implantitis and to compare them with levels in healthy peri-implant sites and severe chronic periodontitis.. Peri-implant/gingival crevicular fluid samples and clinical parameters including: bleeding on probing, modified Plaque Index (PlI), pocket depth and clinical attachment level were collected from 70 patients (23 with peri-implantitis, 25 with healthy peri-implant tissues and 22 with severe chronic periodontitis). The concentrations of sRANKL, RANK and OPG were evaluated using enzyme-linked immunosorbent assays; they were compared between the groups and correlated with the clinical findings.. sRANKL (P = 0.01), RANK (P = 0.01) and OPG (P = 0.03) concentrations were significantly higher in peri-implantitis sites when compared to those in healthy implant sites, although differences in the sRANKL/OPG ratio were not statistically significant. In these sites all three markers were significantly correlated with the clinical parameters, with exception of OPG/PI correlation that remained insignificant (P = 0.121). When comparing peri-implantitis and periodontitis findings, RANK was significantly higher in peri-implantitis sites whereas, sRANKL (P = 0.03) and sRANKL/OPG ratio (P = 0.004) were significantly higher in periodontitis sites. Among periodontitis and healthy implant sites the same differences have been observed for both sRANKL (P = 0.000) and sRANKL/OPG ratio (P = 0.000), furthermore RANK was higher in periodontitis sites as well (P = 0.010).. The findings of this preliminary study on a relatively small sample size suggest that the PICF levels of biomarkers sRANKL, RANK, and OPG are associated with peri-implant tissue destruction and the pattern of these biomarkers differed when compared to periodontitis.

Topics: Adult; Biomarkers; Cross-Sectional Studies; Enzyme-Linked Immunosorbent Assay; Female; Gingival Crevicular Fluid; Humans; Male; Middle Aged; Osteoprotegerin; Peri-Implantitis; Periodontitis; RANK Ligand

Simvastatin is a cholesterol-lowering drug whose pleiotropic effects may have a therapeutic impact on bone. This study evaluates the effect of simvastatin on rats subjected to experimental periodontal disease.. Periodontitis was induced by ligature placement around the maxillary left second molar of rats for 11 days. Groups of six animals received oral saline or simvastatin (3, 10, and 30 mg/kg/day) until sacrifice on day 11. Alveolar bone loss was determined by macroscopic and histologic examination. The serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total alkaline phosphatase (TAP) were evaluated. Gingival myeloperoxidase activity and gingival levels of interleukin-1β (IL-1β), tumor necrosis factor-α, IL-10, reduced glutathione, malonaldehyde, and nitrate/nitrite were analyzed to investigate oxidative stress and inflammation. Expression of inducible nitric oxide synthase (iNOS), matrix metalloproteinases 1 and 8 (MMP-1 and -8), bone morphogenetic protein-2 (BMP-2), receptor activator of nuclear factor κB (RANK), RANK ligand (RANKL), and osteoprotegerin (OPG) were also investigated by immunohistochemistry to assess bone turnover and metabolism. Immunofluorescence microscopy was used to confirm the expression of RANKL in rats' maxillae.. Treatment with simvastatin improved alveolar bone loss within all of the parameters studied, thus demonstrating anti-inflammatory and antioxidant activity. Simvastatin reduced expression of iNOS, MMP-1 and -8, RANK, and RANKL and increased BMP-2 and OPG levels in the periodontal tissue. Simvastatin (30 mg/kg) increased TAP activity on day 11 compared with the saline group. No differences were found in the levels of AST and ALT in any of the groups studied.. The present data suggest that simvastatin prevents inflammatory bone resorption in experimental periodontitis, which may be mediated by its anti-inflammatory and antioxidant properties.

Topics: Alanine Transaminase; Alkaline Phosphatase; Alveolar Bone Loss; Animals; Anti-Inflammatory Agents; Antioxidants; Aspartate Aminotransferases; Bone Morphogenetic Protein 2; Female; Gingiva; Glutathione; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Interleukin-10; Interleukin-1beta; Malondialdehyde; Matrix Metalloproteinase 1; Matrix Metalloproteinase 8; Nitrates; Nitric Oxide Synthase Type II; Nitrites; Osteoprotegerin; Oxidative Stress; Periodontitis; Peroxidase; RANK Ligand; Rats; Rats, Wistar; Receptor Activator of Nuclear Factor-kappa B; Simvastatin; Tumor Necrosis Factor-alpha

The polyunsaturated ω-3 fatty acid eicosapentaenoic acid-derived resolvin E1 (RvE1) enhances resolution of inflammation, prevents bone loss, and induces bone regeneration. Although the inflammation-resolving actions of RvE1 are characterized, the molecular mechanism of its bone-protective actions are of interest. To test the hypothesis that receptor-mediated events impact bone changes, we prepared transgenic mice overexpressing the RvE1 receptor chemokine-like receptor 1 (chemR23) on leukocytes. In zymosan-initiated peritonitis, neutrophil polymorphonuclear leukocyte infiltration in response to RvE1 was limited requiring log order lower doses in chemR23tg mice. Ligature-induced alveolar bone loss was diminished in chemR23tg mice. Local RvE1 treatment of uniform craniotomy in the parietal bone significantly accelerated regeneration of the bone defect. In in vitro bone cultures, RvE1 significantly enhanced expression of osteoprotegerin (OPG) without inducing change in receptor activator of NF-κB ligand levels, whereas the osteogenic markers alkaline phosphatase, bone sialoprotein, and Runt-related transcription factor 2 remained unchanged. These results indicate that RvE1 modulates osteoclast differentiation and bone remodeling by direct actions on bone, rescuing OPG production and restoring a favorable receptor activator of NF-κB ligand/OPG ratio, in addition to known anti-inflammatory and proresolving actions.

Topics: Alveolar Bone Loss; Animals; Bone and Bones; Cell Line; Eicosapentaenoic Acid; Female; Gene Expression; Gene Expression Regulation; Homeostasis; Humans; Leukocytes; Male; Mice; Mice, Transgenic; Osteoblasts; Osteogenesis; Osteoprotegerin; Periodontitis; Peritoneal Cavity; Receptors, Chemokine; Wound Healing

Periodontitis, an inflammatory disease of periodontal tissues, is characterized by excessive alveolar bone resorption. An increase in the receptor activator of nuclear factor-κB ligand (RANKL) to osteoprotegerin (OPG) ratio is thought to reflect the severity of periodontitis. Here, we examined alveolar bone loss in OPG-deficient (OPG(-/-)) mice and RANKL-overexpressing transgenic (RANKL-Tg) mice. Alveolar bone loss in OPG(-/-) mice at 12 weeks was significantly higher than that in RANKL-Tg mice. OPG(-/-) but not RANKL-Tg mice exhibited severe bone resorption especially in cortical areas of the alveolar bone. An increased number of osteoclasts was observed in the cortical areas in OPG(-/-) but not in RANKL-Tg mice. Immunohistochemical analyses showed many OPG-positive signals in osteocytes but not osteoblasts. OPG-positive osteocytes in the cortical area of alveolar bones and long bones were abundant in both wild-type and RANKL-Tg mice. This suggests the resorption in cortical bone areas to be prevented by OPG produced locally. To test the usefulness of OPG(-/-) mice as an animal model for screening drugs to prevent alveolar bone loss, we administered an antimouse RANKL antibody or risedronate, a bisphosphonate, to OPG(-/-) mice. They suppressed alveolar bone resorption effectively. OPG(-/-) mice are useful for screening therapeutic agents against alveolar bone loss.

Topics: Alveolar Bone Loss; Animals; Male; Mandibular Diseases; Mice; Mice, Transgenic; Osteoclasts; Osteoprotegerin; Periodontitis; RANK Ligand

This study is performed to evaluate gingival crevicular fluid (GCF) and serum levels of soluble receptor activator of nuclear factor-κB ligand (sRANKL), interleukin (IL)-17A, IL-17E, IL-17F, IL-17A/F, and osteoprotegerin (OPG) in women with rheumatoid arthritis (RA), osteoporosis (OPR), and those who are systemically healthy (SH), all with periodontal disease.. GCF and serum samples were obtained before any periodontal intervention from 17 women with RA, 19 with OPR, and 13 who were SH with periodontitis. Full-mouth clinical periodontal measurements were recorded. sRANKL, OPG, and IL-17 levels were determined by enzyme-linked immunosorbent assay.. Clinical periodontal measurements were similar in the three study groups. Although the total amounts of GCF albumin, OPG, IL-17A, and IL-17A/F were similar in the study groups, there were statistically significant differences in GCF concentrations of sRANKL, OPG, IL-17A, IL-17E, IL-17F, and IL-17A/F. The sRANKL/OPG ratios were significantly higher in the RA group than in the OPR and SH groups (P <0.05). Serum sRANKL, sRANKL/OPG, and IL-17A/IL-17E ratios were significantly higher, whereas OPG concentrations were significantly lower in the RA group compared to other groups (P <0.05). Serum IL-17A concentrations were significantly higher in the RA and OPR groups than in the SH group (P <0.05).. Increased inflammatory mediator levels in patients with RA, despite the long-term use of various anti-inflammatory drugs, suggest that these patients may have a propensity to overproduce these inflammatory mediators.

Topics: Adult; Aged; Albumins; Arthritis, Rheumatoid; Female; Gingival Crevicular Fluid; Humans; Inflammation Mediators; Interleukin-17; Male; Middle Aged; Osteoporosis; Osteoprotegerin; Periodontal Attachment Loss; Periodontal Index; Periodontal Pocket; Periodontitis; RANK Ligand

Periodontal infections are independent risk factors for atherosclerosis. However, the exact mechanisms underlying this link are yet unclear. Here, we evaluate the in vivo effects of bacteremia with a periodontal pathogen on endothelial progenitors, bone marrow-derived cells capable of endothelial regeneration, and delineate the critical pathways for these effects.. 12-week old C57bl6 wildtype or toll-like receptor (TLR)-2 deficient mice were repeatedly intravenously challenged with 10⁹ live P. gingivalis 381 or vehicle. Numbers of Sca1+/flk1+ progenitors, circulating angiogenic cells, CFU-Hill, and late-outgrowth EPC were measured by FACS/culture. Endothelial function was assessed using isolated organ baths, reendothelization was measured in a carotid injury model. RANKL/osteoprotegerin levels were assessed by ELISA/qPCR.. In wildtype mice challenged with intravenous P.gingivalis, numbers of Sca1+/flk1+ progenitors, CAC, CFU-Hill, and late-outgrowth EPC were strongly increased in peripheral circulation and spleen, whereas Sca1+/flk1+ progenitor numbers in bone marrow decreased. Circulating EPCs were functional, as indicated by improved endothelial function and improved reendothelization in infected mice. The osteoprotegerin/RANKL ratio was increased after P. gingivalis challenge in the bone marrow niche of wildtype mice and late-outgrowth EPC in vitro. Conversely, in mice deficient in TLR2, no increase in progenitor mobilization or osteoprotegerin/RANKL ratio was detected.. Recurrent transient bacteremias, a feature of periodontitis, increase peripheral EPC counts and decrease EPC pools in the bone marrow, thereby possibly reducing overall endothelial regeneration capacity, conceivably explaining pro-atherogenic properties of periodontal infections. These effects are seemingly mediated by toll-like receptor (TLR)-2.

Topics: Animals; Bacteremia; Bacteroidaceae Infections; Bone Marrow Cells; Endothelial Cells; Female; Mice; Mice, Knockout; Neovascularization, Physiologic; Osteoprotegerin; Periodontitis; Porphyromonas gingivalis; RANK Ligand; Stem Cells; Toll-Like Receptor 2

To evaluate the expression of the receptor activator of NF-κB (RANK), the receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG), in the gingival tissue of patients with periodontitis.. Gingival tissue was obtained from 14 systemically healthy subjects with chronic periodontitis during conventional periodontal surgery. Immunohistochemistry was used to detect the expression of RANK, RANKL and OPG in the oral and periodontal pocket epithelium as well as in the connective tissue cells.. RANKL was negatively expressed in both oral and periodontal pocket epithelium. OPG was also negative or weakly positive in the whole epithelium. RANK showed moderate/strong positive staining mainly in the basal and suprabasal layer of oral and periodontal pocket epithelium. In most of the cases, more than 60% of the inflammatory cell infiltrate stained for RANK and RANKL. In these cases the intensity of the stained cells ranged from moderate-to-strong. In less than half of the cases, OPG was positive in more than 60% of the stained cells of the inflammatory cell infiltrate.. The RANK, RANKL and OPG proteins are differentially expressed in periodontal tissues and may play a major role in the bone loss occurring in periodontitis.

Topics: Gingiva; Humans; Immunohistochemistry; Osteoprotegerin; Periodontitis; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B

Evaluate expression of inducible negative regulators of JAK/STAT pathway and their target proteins during the course of ligature-induced experimental periodontal disease in rats.. Rats were sacrificed 07, 15 and 30 days after disease induction for histological evaluation of periodontal inflammation and macroscopic analysis of alveolar bone loss. SOCS expression and the activation status of STAT1 and STAT3 were evaluated in gingival biopsies by real time PCR and Western blot.. Ligature-induced model presented significant progressive bone loss from 7 to 30 days. Inflammation was evident and similar for 07 and 15 days; however, a decrease on severity at the end of the experimental period was observed. There was a significant (p<0.05) increase on SOCS1 and SOCS3 gene expression in PD compared to control group at 15 and 30days. The SOCS1 and SOCS3 protein expression and activation of STAT1 and STAT3 were increased in earlier periods in the ligature model.. This study suggests that SOCS1 and SOCS3 were directly correlated with regulatory mechanism of the inflammatory process responsible for the periodontal disease destruction.

Topics: Alveolar Bone Loss; Animals; Collagen; Connective Tissue; Disease Models, Animal; Fibroblasts; Gingiva; Image Processing, Computer-Assisted; Interleukin-10; Interleukin-6; Janus Kinases; Male; Osteoprotegerin; Periodontitis; RANK Ligand; Rats; Rats, Wistar; Signal Transduction; STAT Transcription Factors; STAT1 Transcription Factor; STAT3 Transcription Factor; Suppressor of Cytokine Signaling 1 Protein; Suppressor of Cytokine Signaling 3 Protein; Suppressor of Cytokine Signaling Proteins; Time Factors; Tumor Necrosis Factor-alpha

Periodontitis is a very prevalent disease. Therefore, biomarkers for the early and standard diagnoses of periodontitis are urgently needed. TACE is a membrane-bound metalloprotease. Although a recent study suggested that TACE levels in GCF are elevated during periodontal disease, the levels of TACE in GCF at different stages of chronic periodontitis have not been determined. Here, we analyzed the protein levels of TACE in GCF from periodontal disease subjects and confirmed that the protein levels of TACE were higher in the moderate periodontitis groups. TACE is known to be a NF-κB ligand that stimulates RANKL secretion in osteoblasts. To understand the effects of TACE on RANKL and OPG in osteoblasts, we treated MG63 cells with TACE. We observed an increase in RANKL protein expression but a decrease in OPG protein expression. Our data suggest that TACE can induce RANKL expression and promote osteoclastogenesis, thus worsening the outcome of periodontitis.

Topics: ADAM Proteins; ADAM17 Protein; Adult; Biomarkers; Cell Line, Tumor; Female; Gingiva; Gingival Crevicular Fluid; Humans; Male; Middle Aged; Osteoblasts; Osteoprotegerin; Periodontitis; RANK Ligand; Reproducibility of Results

The purpose of this study was to assess the role of anti-bone resorptive agents and an anti-inflammatory compound in murine Porphyromonas gingivalis (P. gingivalis)-induced periodontitis.. Six randomly assigned groups were administered vehicle (saline, control) (n = 6), P. gingivalis infection only (untreated) (n = 6), human-Fc (n = 4), Kavain (n = 6), OPG-Fc (n = 6) and Receptor activator of nuclear factor-kappa B (RANK)-Fc (n = 6) intraperitoneally at day 0, 3 and 7. Animals were euthanized on day 10 and subjected to comprehensive histomorphometric analysis. To capture the progress of inflammation, serum samples were collected at days 0, 3, 7 and 10 for levels of pro-inflammatory cytokines.. Compared with control group, OPG-Fc, RANK-Fc and Kavain treatment showed significant bone loss reduction with OPG-Fc performing better than RANK-Fc or Kavain. Epithelial down-growth showed significant reduction in treatment groups with OPG-Fc performing better than RANK-Fc or Kavain. Finally, Kavain, OPG-Fc and RANK-Fc-treated mice displayed reduced inflammatory cell counts and cytokine expression particularly at day 7 postinfection.. RANKL antagonists and Kavain effectively reduced alveolar bone loss in P. gingivalis-induced periodontitis in our mice model. Compared with RANK-Fc, Kavain-treated animals showed milder improvement of bone and connective tissue inflammation. Therapeutic implications in the prevention of periodontal bone loss are discussed.

Topics: Alveolar Bone Loss; Animals; Chemokine CCL2; Interleukin-6; Male; Mice; Mice, Inbred C57BL; Osteoprotegerin; Periodontitis; Porphyromonas gingivalis; Pyrones; Random Allocation; RANK Ligand; Recombinant Fusion Proteins; Tumor Necrosis Factor-alpha

The aim of this study was to compare antimicrobial photodynamic therapy (aPDT) as an adjunctive treatment to scaling and root planing (SRP) for induced periodontitis in nicotine-modified rats.. A total of 240 rats were evenly divided into two groups: C - saline solution treatment; N - nicotine treatment. Periodontal disease was induced in both groups at the first mandibular molar. After 7 days, the ligature was removed. All animals were submitted to SRP and were divided according to the following treatments: SRP - irrigation with saline solution; Toluidine Blue-O (TBO) - irrigation with phenothiazinium dye (100 μg/ml); LLLT - laser irradiation (660 nm; 0.03 W; 4 J); and aPDT - TBO and laser irradiation. Ten animals in each group/treatment were euthanized at 7, 15 and 30 days. The histometric and immunohistochemical values were statistically analysed.. Intragroup analysis demonstrated that in both groups the aPDT treatment resulted in lower bone loss (BL) when compared to SRP in all experimental periods. Intergroup analysis demonstrated that aPDT treatment resulted in lower BL in Group N than in Group C treated with SRP in all experimental periods.. Antimicrobial photodynamic therapy was an effective adjunctive treatment to SRP for induced periodontitis in nicotine-modified rats.

Topics: Alveolar Bone Loss; Animals; Bacteria; Combined Modality Therapy; Dental Prophylaxis; Disease Models, Animal; Immunohistochemistry; Immunosuppressive Agents; Male; Mandible; Molar; Nicotine; Osteoprotegerin; Periodontitis; Photochemotherapy; Photosensitizing Agents; Random Allocation; RANK Ligand; Rats; Rats, Wistar

Recent research evidence shows that the receptor activator of nuclear factor-kappa B ligand (RANKL) and osteoprotegerin (OPG) play an important role in osteoclastogenesis and the inflammatory bone loss during periodontitis. Bone remodeling process is dependent on the balance of these two proteins while a high ratio of RANKL/OPG characterizes the increased osteolytic process and it has been reported in inflammatory diseases including the periodontal disease. The purpose of this study was to determine the OPG and RANKL mRNA levels in periodontal tissues derived from patients with advanced chronic periodontitis after non-surgical periodontal therapy (SRP) and to compare the RANKL/OPG ration with that in healthy persons. Gingival biopsies were obtained from subjects with clinically healthy periodontium (H) (N = 11) and patients with advanced chronic periodontitis (CP) (N = 14). Total RNA was isolated from the gingival samples and 1 microg RNA was reverse transcribed to cDNA, followed by polymerase chain reaction (PCR) using specific primers for OPG and RANKL. The efficiency of reverse transcription was verified by the amplification of the GAPDH gene. The intensity of RT-PCR products was analyzed by a densitometer and was normalized to the intensity of the band for the housekeeping gene GAPDH. Immunohistochemical evaluation of the RANKL and OPG expression was also performed. The expression of RANKL as well as of OPG was reduced in CP specimens in comparison to that of healthy persons in a statistical significant way. However, the RANKL/OPG ratio showed to be slightly elevated in CP compared to H specimens but this finding was not of statistical significance. The immunohistochemical analysis revealed a non-uniform expression pattern for both proteins. Although further investigation is needed to identify the specific role of RANKL and OPG protein in periodontitis progression, our data after SRP might indicate the possible involvement of these proteins in the activation of pathways, which regulate the repair of the periodontal tissues.

Topics: Adult; Biopsy; Gene Expression; Gingiva; Humans; Immunohistochemistry; Middle Aged; Mouth Mucosa; Osteoprotegerin; Periodontitis; RANK Ligand; RNA, Messenger; Severity of Illness Index; Signal Transduction

Bovine lactoferrin (bLF) modulates the production of proinflammatory cytokines including tumor necrosis factor (TNF)-alpha, and may thus control alveolar bone destruction associated with periodontitis. In this study, the effects of bLF on mRNA expression in lipopolysaccharide (LPS)-stimulated osteoblasts (OBs) and on LPS-induced osteoclastogenesis were examined. The inhibitory effects of oral administration of liposomal-bLF (L-bLF), which improved the robustness of bLF to digestive enzymes, on alveolar bone resorption using LPS-induced periodontitis rat model are also reported. Three groups of 7-week-old male Wistar rats were treated with L-bLF (L-bLF group), bLF (bLF group), or the vehicle (control group) in drinking water (n=6 in each group). On day 7, LPS was topically applied into the gingival sulcus. Number of osteoclasts and immunoexpression of TNF-alpha were analyzed. The bLF inhibited the upregulation of TNF-alpha-mRNA- and upregulation of receptor activator of NF kappaB (RANKL)-mRNA expression and eliminated downregulation of osteoprotegerin (OPG)-mRNA expression in LPS-stimulated OBs and reduced LPS-induced osteoclastogenesis in co-culture with primary OBs and bone marrow cells. In the control group, the number of osteoclasts increased after LPS treatment. The number of osteoclasts that appeared along the alveolar bone margin was significantly reduced (P<0.01) in the L-bLF but not in the bLF group. Furthermore, L-bLF suppressed upregulation of TNF-alpha immunoexpression in periodontal tissue and TNF-alpha and interleukin (IL)-1 beta-mRNA level in gingival tissue. The results of this study indicate that oral administration of L-bLF significantly reduces alveolar bone resorption induced by LPS stimulation through inhibition of TNF-alpha production and modulation of RANKL/OPG balance in OBs. It is suggested that L-bLF could be a potent therapeutic and preventive agent for attenuating alveolar bone destruction in periodontitis patients.

Topics: Alveolar Bone Loss; Animals; Bone Marrow Cells; Bone Resorption; Cattle; Coculture Techniques; Cytokines; Gingiva; Interleukin-1; Lactoferrin; Lipopolysaccharides; Male; Osteoblasts; Osteoclasts; Osteoprotegerin; Periodontitis; Rats; Rats, Wistar; Receptor Activator of Nuclear Factor-kappa B; Tumor Necrosis Factor-alpha

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.. 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.. 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.. 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.

Topics: Actinobacillus Infections; Aggregatibacter actinomycetemcomitans; Alveolar Bone Loss; Animals; C-Reactive Protein; Cell Movement; Colony Count, Microbial; Disease Susceptibility; Host-Pathogen Interactions; Interleukin-17; Interleukin-1beta; Leukocyte Count; Leukocytes; Male; Matrix Metalloproteinase 13; Matrix Metalloproteinase 2; Mice; Nitric Oxide Synthase Type II; Osteoprotegerin; Periodontitis; Peroxidase; RANK Ligand; Tissue Inhibitor of Metalloproteinase-1; Tissue Inhibitor of Metalloproteinase-3; Tumor Necrosis Factor-alpha

The objectives of this study were to clinically and immunologically assess the effects of mechanical anti-infective therapies for mucositis and peri-implantitis and to compare the levels of cytokines in untreated and treated peri-implant diseased sites to healthy ones.. Titanium dental implants were assigned to one of the following groups: healthy (n = 10) = control; mucositis (n = 10) = mechanical debridement using abrasive sodium carbonate air-powder and resin curets; and peri-implantitis (n = 20) = open surgical debridement using abrasive sodium carbonate air-powder and resin curets. Visible plaque accumulation, marginal bleeding, bleeding on probing, suppuration, and probing depth were assessed at baseline for all groups and at 3 months after therapies for diseased groups. At these times, the total amounts of interleukin (IL)-4, -10, and -12, tumor necrosis factor-alpha (TNF-alpha), receptor activator of nuclear factor-kappa B ligand (RANKL), and osteoprotegerin (OPG) in the peri-implant crevicular fluid (PICF) were measured by enzyme-linked immunosorbent assay.. At 3 months, the anti-infective treatments resulted in a significant improvement in all clinical parameters for mucositis and peri-implantitis (P <0.05). Moreover, the total amounts of TNF-alpha in PICF were significantly higher in untreated diseased implants compared to healthy ones, and the OPG/RANKL ratio was higher for healthy implants than for untreated peri-implantitis (P <0.05). TNF-alpha levels were significantly reduced for both diseased groups (P <0.05), achieving the same level as the healthy group at 3 months after therapies (P >0.05).. The proposed anti-infective therapies may locally modulate the levels of TNF-alpha and the OPG/RANKL ratio and improve clinical parameters around peri-implant tissues.

Topics: Adult; Aged; Anti-Infective Agents, Local; Case-Control Studies; Chlorhexidine; Cytokines; Dental Implantation, Endosseous; Dental Implants; Dental Plaque Index; Dental Scaling; Female; Gingival Crevicular Fluid; Humans; Interleukins; Male; Middle Aged; Mouthwashes; Mucositis; Osteoprotegerin; Periodontal Index; Periodontitis; RANK Ligand; Stomatitis; Tumor Necrosis Factor-alpha

This study assessed gene expression by quantitative polymerase chain reaction of inflammatory- [interleukin (IL)-12, tumor necrosis factor-alpha (TNF-alpha), IL-4, and IL-10] and osteoclastogenesis-related factors [receptor activator of NF-kappaB ligand (RANKL) and osteoprotegerin (OPG)] in sites exhibiting different severities of peri-implant disease.. Peri-implant soft tissue biopsies (n=48) were harvested from healthy implant (HI), mucositis (MC), initial peri-implantitis (IP) and severe peri-implantitis (SP) sites.. IL-12 and TNF-alpha mRNA levels were higher in SP, followed by IP and MC (P <0.05). IL-4 was higher in HI, followed by MC, SP and IP (P <0.05). IL-10 was the lowest in HI, while no differences were detected among the diseased groups (P>0.05). OPG mRNA levels were higher in HI, followed by IP, SP and MC, whereas RANKL was increased as the peri-implantitis severity increased (P<0.05). The highest OPG/RANKL ratio was observed in HI and the lowest in SP (P<0.01).. These findings suggest that expressions of inflammatory- and osteoclastogenesis-related factors may play an important role in the onset and severity of the peri-implant diseases.

Topics: Adult; Analysis of Variance; Cell Differentiation; Cytokines; Dental Implants; Female; Gene Expression Regulation; Humans; Interleukin-10; Interleukin-12; Interleukin-4; Jaw, Edentulous; Male; Middle Aged; Mucositis; Osteoclasts; Osteoprotegerin; Periodontitis; RANK Ligand; Reference Values; RNA, Messenger; Severity of Illness Index; Tumor Necrosis Factor-alpha

To compare the levels of the soluble receptor activator of nuclear factor kappa B ligand (sRANKL), osteoprotegerin (OPG) and their relative ratio in gingival crevicular fluid (GCF) among periodontitis patients with varying smoking histories.. GCF samples were collected from 149 periodontitis patients who were never smokers (n=58), former smokers (n=39) and current smokers (n=52). sRANKL and OPG concentrations in GCF were measured by enzyme-linked immunosorbent assays.. sRANKL, OPG and their relative ratio were not statistically significant among the never smokers, former smokers and current smokers. However, OPG was significantly reduced and subsequently the sRANKL:OPG ratio was significantly increased in the high pack-years group as compared with never smokers. The positive correlation between pack-years and the sRANKL:OPG ratio remained statistically significant after adjusting for age and current smoking status.. Increased lifetime exposure to cigarette smoking above a minimum threshold suppresses OPG production and leads to increased sRANKL:OPG. This may partially explain increased bone loss in smoking-related periodontitis.

Topics: Adult; Age Factors; Aged; Aged, 80 and over; Alveolar Bone Loss; Case-Control Studies; Enzyme-Linked Immunosorbent Assay; Female; Gingival Crevicular Fluid; Humans; Male; Middle Aged; Osteoprotegerin; Periodontitis; RANK Ligand; Smoking

To determine plasma concentrations of bone metabolism markers in type 1 diabetes mellitus patients and non-diabetic and to evaluate the influence of periodontitis on biomarkers of bone formation in these patient groups.. Plasma concentrations of receptor activator of nuclear factor-kappaB ligand (RANKL), osteoprotegerin (OPG), C-terminal telopeptide of type 1 collagen and osteocalcin were measured in type 1 diabetes mellitus patients (n=63) and non-diabetics (n=38) who were also subdivided on the basis of their periodontal status.. Diabetics had significantly lower osteocalcin concentrations, lower RANKL to OPG ratios and higher OPG concentrations (as shown by other researchers) than non-diabetics. The ratio of RANKL to OPG was altered by the periodontal status. Osteocalcin had a negative correlation and OPG a positive correlation with the percentage of glycated haemoglobin in the blood.. Because, osteocalcin, a biomarker of bone formation, is lower in patients with periodontitis and in patients with type 1 diabetes mellitus with and without periodontitis than in non-diabetics without periodontitis, this might indicate that diabetics are less able to replace bone lost during active bursts of periodontitis and explain the greater severity of disease seen in studies of patients with diabetes.

Topics: Adult; Biomarkers; Bone Resorption; Collagen Type I; Diabetes Mellitus, Type 1; Female; Gingival Hemorrhage; Gingival Recession; Glycated Hemoglobin; Humans; Male; Middle Aged; Osteocalcin; Osteogenesis; Osteoprotegerin; Peptide Fragments; Peptides; Periodontal Attachment Loss; Periodontal Pocket; Periodontitis; Procollagen; RANK Ligand; Young Adult

The aim of the present study was to evaluate the therapeutic efficacy of vasoactive intestinal peptide (VIP), an immunoregulatory molecule, in experimental periodontitis.. Sixty-three male Sprague-Dawley rats were divided into five groups: control; lipopolysaccharide (LPS); LPS + 0.1 nmol VIP; LPS + 1 nmol VIP; and LPS + 10 nmol VIP. Saline was injected into the gingiva of control rats on days 1, 3, and 5, whereas the other groups received injections of Escherichia coli LPS. VIP groups received intraperitoneal injections of relevant dosages on days 2, 4, 6, 8, and 10. The control and LPS groups were given saline instead of VIP in the same manner. On day 11, serum samples were obtained, and rats were sacrificed. Alveolar bone loss; serum levels of tumor necrosis factor-alpha, interleukin (IL)-1beta, -10, and -18, soluble receptor activator of nuclear factor-kappa B ligand (sRANKL), and osteoprotegerin (OPG); and the immune expression of RANKL and OPG were evaluated.. The application of VIP caused a dose-dependent decline in alveolar bone loss compared to the LPS group, but the differences were not significant (P >0.05). A reduction in the histologic findings of inflammation was observed in all VIP groups. The 1- and 10-nmol VIP groups showed significantly lower serum sRANKL and OPG levels compared to the LPS group (P <0.05). The number of positively stained vessels for endothelial OPG was greater in the 1-nmol VIP group than in the LPS group (P <0.05).. When periodontitis was induced by E. coli LPS, VIP downregulated the inflammatory response and inhibited alveolar bone loss, possibly by differentially regulating the tissue levels of RANKL and OPG.

Topics: Alveolar Bone Loss; Animals; Dose-Response Relationship, Drug; Down-Regulation; Endothelium, Vascular; Escherichia coli; Immunologic Factors; Injections, Intraperitoneal; Interleukin-10; Interleukin-18; Interleukin-1beta; Lipopolysaccharides; Male; Osteoprotegerin; Periodontitis; Random Allocation; RANK Ligand; Rats; Rats, Sprague-Dawley; Sodium Chloride; Time Factors; Treatment Outcome; Tumor Necrosis Factor-alpha; Vasoactive Intestinal Peptide

Chronic kidney disease (CKD) is a complex disorder, which results in several complications involving disturbance of mineral metabolism. Periodontal disease is an infectious disease that appears to be an important cause of systemic inflammation in CKD patients. Periodontal disease is characterized by clinical attachment loss (CAL) caused by alveolar bone resorption around teeth, which may lead to tooth loss. Osteoprotegerin (OPG) is a key regulator of osteoclastogenesis. Polymorphisms are the main source of genetic variation, and single nucleotide polymorphisms (SNPs) have been reported as major modulators of disease susceptibility. The aim of this study was to investigate the association of a polymorphism located at position -223 in the untranslated region of the OPG gene, previously known as -950, with susceptibility to CKD and periodontal disease.. A sample of 224 subjects without and with CKD (in hemodialysis) was divided into groups with and without periodontal disease. The OPG polymorphism was analyzed by polymerase chain reaction and restriction fragment length polymorphism.. No association was found between the studied OPG polymorphism and susceptibility to CKD or periodontal disease.. It was concluded that polymorphism OPG-223 (C/T) was not associated with CKD and periodontal disease in a Brazilian population. Studies on other polymorphisms in this and other genes of the host response could help to clarify the involvement of bone metabolism mediators in the susceptibility to CKD and periodontal disease.

Topics: Adult; Aged; Brazil; Female; Gene Frequency; Genetic Predisposition to Disease; Humans; Kidney Failure, Chronic; Male; Middle Aged; Osteoprotegerin; Periodontitis; Polymorphism, Restriction Fragment Length; Polymorphism, Single Nucleotide; Promoter Regions, Genetic; Young Adult

It has been demonstrated that genetic variation accounts for approximately half of the variance in periodontitis. The reported association of polymorphisms in the osteoprotegerin (OPG) gene with osteoporosis suggests that the OPG gene may also influence the genetic risk for periodontitis.. We investigated the distribution of OPG gene polymorphisms in 49 patients with aggressive (n = 14) or chronic (n = 35) periodontitis and 49 control subjects without periodontitis, using polymerase chain reaction (PCR)-restriction fragment length polymorphism and PCR-single strand conformation polymorphism followed by direct sequencing.. A total of seven known polymorphisms and one new mutation, G373A, were identified. The T950 and G1181 alleles were more common in patients with periodontitis (P = 0.028 and P = 0.047, respectively) than in control subjects. Especially, G1181 allele was associated with patients with aggressive periodontitis.. The TG haplotype of T950C and G1181C polymorphisms in the OPG gene may be useful genetic markers for the prediction of periodontitis. Further studies in a larger population are required to determine whether these alleles directly contribute to periodontitis susceptibility.

Topics: Adult; Case-Control Studies; Chronic Disease; Female; Gene Frequency; Genetic Predisposition to Disease; Haplotypes; Humans; Male; Middle Aged; Osteoprotegerin; Periodontitis; Polymorphism, Genetic; Reference Values; Severity of Illness Index

To investigate the effects of estrogen-deficiency upon the expression of osteoprotegerin (OPG) in alveolar bone so as to clarify the role of estrogen in alveolar bone metabolism.. Fifty-three SD rats were randomly divided into 3 groups: OVX group (n=18) undergoing bilateral ovariectomy, OVX + E2 group (n=18), undergoing bilateral ovariectomy and subcutaneous injection of estradiol once 3 days since day 2 after the operation, and sham operation group (n=17) undergoing sham operation. Four weeks after the operation periodontal ligature was conducted and high-sugar diet was fed to establish periodontitis models. Four weeks later the rats were killed. The morphological changes and expression of OPG in alveolar bone were observed by light microscopy and immunohistochemistry.. All the rats showed sparseness of bone trabeculae in alveolar bone and osteoclasts and lacuna at the surface of alveolar bone, especially the rate of the group OVX. The A values (absorption of the OPG expression) in the alveolar bone of the OVX groups was 27 854 +/- 5246, significantly lower than those of the sham operation group and OVX + E2 group (38 799 +/- 6228 and 37 146 +/- 6394 respectively, both P < 0.05) without significant difference between the sham operation group and OVX + E2 group (P > 0.05).. Estrogen deficiency decreases the expression of OPG in alveolar bone, and enhances the absorption of alveolar bone.

Topics: Alveolar Process; Animals; Estrogens; Female; Immunohistochemistry; Osteoprotegerin; Ovariectomy; Periodontitis; Rats; Rats, Sprague-Dawley

To evaluate the levels of soluble receptor activator of nuclear factor-kappaB ligand (sRANKL) and osteoprotegerin (OPG) in crevicular fluid of endosseous dental implants.. Eighty-six implants in 39 patients were evaluated. All patients were treated with root-type implants placed at least 16 months and loaded at least 12 months before the examination. Peri-implant crevicular fluid (PICF) samples were obtained from buccal and lingual aspects of implants. Modified plaque index, probing depth, gingival index, and bleeding on probing (BOP) were recorded at four sites per implant. PICF levels of sRANKL and OPG were analysed by ELISA. Spearman's correlations were utilised to relate biochemical data and clinical parameters.. The PICF level of sRANKL did not show significant correlation with the clinical parameters or the OPG level. The total amount of OPG was positively correlated with PICF volume, gingival index, and BOP (P<0.05) and negatively correlated with pack years (P<0.05).. The findings of this preliminary study suggest that the crevicular fluid level of OPG deserves further investigation as a possible marker to evaluate the health status of surrounding tissues of dental implants, as this was not the case for the sRANKL level. Larger scale studies, particularly in peri-implantitis cases, may shed more light on this subject.

Topics: Adult; Aged; Alveolar Bone Loss; Biomarkers; Dental Implantation, Endosseous; Dental Implants; Enzyme-Linked Immunosorbent Assay; Female; Gingival Crevicular Fluid; Humans; Male; Middle Aged; Osteoprotegerin; Periodontal Index; Periodontitis; RANK Ligand; Statistics, Nonparametric

The present study aimed to evaluate whether chronic stress (CS) affects ligature-induced periodontal disease and to investigate the impact of CS on the mRNA levels of interleukin (IL)-1beta, -1 receptor antagonist, -6, and -10, interferon-gamma (IFN-gamma), receptor activator of nuclear factor-kappa B ligand (RANKL), and osteoprotegerin in the gingival tissues of rats.. Sixty male Wistar rats were assigned randomly to three groups: G1 (control; non-ligated sites), G2 (periodontal disease), and G3 (periodontal disease associated with restraint stress for 12 hours/day for the entire study). After 30 days, all animals were sacrificed by decapitation. Blood samples were taken, and the concentrations of corticosterone and catecholamines were measured as biomarkers of CS. Marginal tissues around ligated and non-ligated teeth were harvested, and gene expression was assessed by quantitative polymerase chain reaction. Moreover, the area of bone loss (ABL) was determined histometrically.. Data analysis showed that CS increased serum levels of stress biomarkers (P <0.05), ligature placement resulted in a significant ABL compared to non-ligated sites, CS significantly increased the amount of ABL in inflamed sites (P <0.001), and CS significantly increased mRNA levels of proinflammatory (IL-1beta and -6 and IFN-gamma) and anti-inflammatory (IL-10) cytokines and proresorptive factor (RANKL) in ligated sites (P <0.05).. CS significantly increased bone loss resulting from ligature-induced periodontitis by a local increase in proinflammatory and proresorptive factors.

Topics: Alveolar Bone Loss; Animals; Biomarkers; Catecholamines; Chronic Disease; Corticosterone; Gingiva; Inflammation Mediators; Interferon-gamma; Interleukin 1 Receptor Antagonist Protein; Interleukin-10; Interleukin-1beta; Interleukin-6; Male; Osteoprotegerin; Periodontitis; Random Allocation; RANK Ligand; Rats; Rats, Wistar; Receptors, Interleukin-1; RNA, Messenger; Stress, Physiological

This study evaluated the effect of smoking on the gene expression of interleukin-1alpha, -1ra, -6, -8 and -10, tumor necrosis factor-alpha, matrix metalloproteinase (MMP)-2 and -8, receptor activator of NF-kappaB ligand (RANKL) and osteoprotegerin, in sites with periodontitis.. Gingival biopsies were divided into three groups: the healthy group (periodontally healthy subjects; n=10); the periodontitis group [subjects with severe chronic periodontitis who never smoked (probing depth>or=7 mm) (n=25)]; and the smoking group (subjects diagnosed with severe chronic periodontitis who smoked>or=1 pack per day for at least 10 years; n=25). Gene and protein expressions were analyzed by quantitative polymerase chain reaction and enzyme-linked immunosorbent assay, respectively.. Data analysis demonstrated that, except for MMP-8 and osteoprotegerin, the levels of all factors were increased by inflammation (p<0.001). The levels of interleukin-1alpha, -1ra, -6 and -8, and RANKL, were higher in smokers with periodontitis compared with controls, whereas the levels of interleukin-10, MMP-8 and osteoprotegerin were lower (p<0.001). Smoking lowered the levels of interleukin-1alpha, -8, -10, tumor necrosis factor-alpha, MMP-8 and osteoprotegerin, and increased the levels of interleukin-6 and -1ra in sites with a comparable type of periodontitis (p<0.001).. In conclusion, smoking modulates gene expression in the periodontium, and the influence of smoking on periodontal disease may involve effects of interleukin-6:interleukin-10 and RANKL:osteoprotegerin ratios.

Topics: Analysis of Variance; Case-Control Studies; Chronic Disease; Enzyme-Linked Immunosorbent Assay; Female; Gene Expression; Humans; Interleukins; Male; Matrix Metalloproteinases; Osteoprotegerin; Periodontitis; RANK Ligand; Reverse Transcriptase Polymerase Chain Reaction; Smoking; Statistics, Nonparametric; Tumor Necrosis Factor-alpha

Receptor activator of NF-kappaB ligand (RANKL) and osteoprotegerin (OPG) are a system of molecules that regulate bone resorption. This study aims to compare the levels of RANKL, OPG and their relative ratio in gingival crevicular fluid (GCF) of healthy and periodontal disease subjects.. GCF was obtained from healthy (n=21), gingivitis (n=22), chronic periodontitis (n=28), generalized aggressive periodontitis (n=25) and chronic periodontitis subjects under immunosuppressant therapy (n=11). RANKL and OPG concentrations in GCF were measured by enzyme-linked immunosorbent assays.. RANKL levels were low in health and gingivitis groups, but increased in all three forms of periodontitis. OPG levels were higher in health than all three periodontitis, or gingivitis groups. There were no differences in RANKL and OPG levels between chronic and generalized aggressive periodontitis groups, whereas these were lower in the immunosuppressed chronic periodontitis group. The RANKL/OPG ratio was significantly elevated in all three periodontitis forms, compared with health or gingivitis, and positively correlated to probing pocket depth and clinical attachment level.. GCF RANKL and OPG levels were oppositely regulated in periodontitis, but not gingivitis, resulting in an enhanced RANKL/OPG ratio. This ratio was similar in all three periodontitis groups and may therefore predict disease occurrence.

Topics: Adolescent; Adult; Alveolar Bone Loss; Case-Control Studies; Female; Gingival Crevicular Fluid; Gingivitis; Humans; Immunosuppression Therapy; Male; Middle Aged; Osteoprotegerin; Periodontitis; RANK Ligand; Statistics, Nonparametric

The serum concentrations of receptor activator of nuclear factor kappaB ligand (RANKL) and osteoprotegerin (OPG) in age- and sex-matched groups of smokers and non-smokers with almost identical levels of periodontal disease were determined by an enzyme-linked immunosorbent assay (ELISA). We ensured that the 35 smokers were gender, age and clinically matched with a group of 35 non-smokers (confirmed by cotinine immunoassay) from the same population of maintained patients with susceptibility to periodontitis.. Cigarette smoker patients tended to have lower serum concentrations of RANKL and OPG than non-smoker patients. While no statistically significant difference was observed for RANKL, there were significant differences in the median serum concentration of OPG (smokers 23.76 pM, non-smokers 59.28 pM) and the ratio of serum concentrations of RANKL and OPG. Concentrations of OPG in the smoker patients also had a statistically significant negative correlation with tobacco consumption.. Bone loss in smoker-related periodontitis patients may be partially explained by suppression of OPG production.

Topics: Adult; Alveolar Bone Loss; Case-Control Studies; Dental Prophylaxis; Enzyme-Linked Immunosorbent Assay; Female; Humans; Male; Middle Aged; Osteoprotegerin; Periodontitis; RANK Ligand; Smoking

Receptor activator of nuclear factor-kappa B (NF-kappaB) ligand (RANKL) and osteoprotegerin (OPG) are critical for homeostatic control of osteoclast activity, suggesting their vital roles in the progression of bone loss in periodontitis. In this study, the expression of RANKL and OPG mRNA and the relationship between these factors and periodontopathic bacteria in periodontal tissue were studied.. Gingival tissue and subgingival plaque samples were collected from 15 patients with chronic periodontitis and 15 periodontally healthy subjects. RNA was extracted from the tissue and subjected to reverse transcription-polymerase chain reaction (RT-PCR) using primers specific for RANKL or OPG. Beta-actin was amplified as a control to ensure equal loading. The intensity of RT-PCR products was analyzed by a densitometer in proportion to the intensity of beta-actin. The numbers of Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans were determined by quantitative real-time PCR.. Our results showed increased levels of RANKL mRNA in chronic periodontitis tissues. The RANKL/OPG expression ratio was significantly higher in the periodontitis group compared to the healthy control group (P = 0.001). Interestingly, the expression of RANKL (r = 0.64; P <0.001), but not OPG (r = -0.24; P = 0.20), was significantly correlated with increased numbers of P. gingivalis. A. actinomycetemcomitans was detected in only 6.7% of all sites.. Chronic periodontitis was associated with RANKL mRNA upregulation and increased RANKL/OPG mRNA expression ratio. In addition, our data showed for the first time to our knowledge an association between upregulated RANKL levels and the number of P. gingivalis in clinically obtained periodontal tissues.

Topics: Actins; Adult; Age Factors; Aggregatibacter actinomycetemcomitans; Chronic Disease; Dental Plaque; Epidemiologic Methods; Female; Gingiva; Humans; Male; Middle Aged; Osteoprotegerin; Periodontitis; Porphyromonas gingivalis; RANK Ligand; Reverse Transcriptase Polymerase Chain Reaction; RNA; RNA, Messenger; Sex Factors; Up-Regulation

Periodontitis is an inflammatory bone disease caused by Gram-negative anaerobic bacteria. Osteoclast differentiation is regulated by the balance between receptor activator of nuclear factor kappa B ligand (RANKL) and osteoprotegerin (OPG). The purpose of this study was to examine the mechanism of OPG production in human gingival fibroblasts (HGF) stimulated by lipopolysaccharide (LPS) from periodontopathic bacteria. The expressions of Toll-like receptor 2 (TLR-2) and TLR-4 in HGF were examined using flow-cytometry. HGF were stimulated with whole cell extracts or LPS from Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis with or without polymyxin B, a LPS inhibitor. In addition, HGF were stimulated with LPS, prostaglandin E(2) (PGE(2)), various agonists of PGE receptors (EP1, EP2, EP3 and EP4 agonists) with or without indomethacin (IND), a prostaglandin synthesis inhibitor. OPG and PGE(2) production was measured using an enzyme-linked immunosorbent assay (ELISA). HGF expressed both TLR-2 and TLR-4. Both A. actinomycetemcomitans and P. gingivalis LPS augmented OPG expression in HGF. Whole cell extracts from A. actinomycetemcomitans and P. gingivalis augmented OPG production by HGF; the augmentation was suppressed by polymyxin B. IND suppressed OPG production in LPS-stimulated HGF. PGE(2) stimulated HGF to produce OPG. EP1 and EP2 agonists, but not EP3 and EP4 agonists, increased OPG production by HGF. These results suggest that LPS-induced OPG production by HGF is regulated via EP1 and/or EP2 receptors by endogenously generated PGE(2).

Topics: Cells, Cultured; Chronic Disease; Dinoprostone; Dose-Response Relationship, Drug; Fibroblasts; Gingiva; Humans; Lipopolysaccharides; Osteoprotegerin; Periodontitis; Receptors, Prostaglandin E; Toll-Like Receptor 2; Toll-Like Receptor 4

Receptor activator of nuclear factor-kappaB ligand (RANKL) is responsible for the induction of osteoclastogenesis and bone resorption, whereas its decoy receptor, osteoprotegerin, can directly block this action. Because this dyad of cytokines is crucial for regulating the bone remodelling process, imbalances in their expression may cause a switch from the physiological state to enhanced bone resorption or formation. This study investigated the mRNA expression of RANKL and osteoprotegerin, as well as their relative ratio, in the gingival tissues of patients with various forms of periodontal diseases.. Gingival tissue was obtained from nine healthy subjects and 41 patients, who had gingivitis, chronic periodontitis, generalized aggressive periodontitis, and chronic periodontitis and were receiving immunosuppressant therapy. Quantitative real-time polymerase chain reaction was employed to evaluate the mRNA expression of RANKL and osteoprotegerin in these tissues.. Compared with healthy individuals, patients in all periodontitis groups, but not those with gingivitis, exhibited stronger RANKL expression and a higher relative RANKL/osteoprotegerin ratio. In addition, osteoprotegerin expression was weaker in patients with chronic periodontitis. When patients with generalized aggressive periodontitis and chronic periodontitis were compared, the former exhibited stronger RANKL expression, whereas the latter exhibited weaker osteoprotegerin expression, and there was no difference in their relative ratio. When chronic periodontitis patients were compared with chronic periodontitis patients receiving immunosuppressant therapy, osteoprotegerin, but not RANKL, expression was stronger in the latter.. This study demonstrates that RANKL and osteoprotegerin expression are differentially regulated in various forms of periodontitis, and the relative RANKL/osteoprotegerin ratio appears to be indicative of disease occurrence. This information may confer diagnostic and therapeutic value in periodontitis.

Topics: Adolescent; Adult; Case-Control Studies; Chronic Disease; Female; Gingiva; Humans; Immunocompromised Host; Male; Middle Aged; Osteoprotegerin; Periodontal Attachment Loss; Periodontal Index; Periodontitis; RANK Ligand; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Statistics, Nonparametric

Prevention of alveolar bone destruction is a clinical challenge in periodontal disease treatment. The receptor activator of nuclear factor-kappa B ligand (RANKL) inhibitor osteoprotegerin (OPG) inhibits osteoclastogenesis and suppresses bone resorption.. To study the effects of RANKL inhibition on alveolar bone loss, an experimental ligature-induced model of periodontitis was used. A total of 32 rats were administered human OPG-Fc fusion protein (10 mg/kg) or vehicle by subcutaneous delivery twice weekly for 6 weeks. Negative or positive controls received no treatment or disease through vehicle delivery, respectively. Biopsies were harvested after 3 and 6 weeks, and mandibulae were evaluated by microcomputed tomography (microCT) and histology. Serum levels of human OPG-Fc and tartrate-resistant acid phosphatase-5b (TRAP-5b) were measured throughout the study by enzyme-linked immunosorbent assay (ELISA). Statistical analyses included analysis of variance (ANOVA) and Tukey tests.. Human OPG-Fc was detected in the sera of OPG-Fc-treated animals by 3 days and throughout the study. Serum TRAP-5b was sharply decreased by OPG-Fc treatment soon after OPG-Fc delivery and remained low for the observation period. Significant preservation of alveolar bone volume was observed among OPG-Fc-treated animals compared to the controls at weeks 3 and 6 (P <0.05). Descriptive histology revealed that OPG-Fc significantly suppressed osteoclast surface area at the alveolar crest.. Systemic delivery of OPG-Fc inhibits alveolar bone resorption in experimental periodontitis, suggesting that RANKL inhibition may represent an important therapeutic strategy for the prevention of progressive alveolar bone loss.

Topics: Acid Phosphatase; Alveolar Bone Loss; Analysis of Variance; Animals; Disease Models, Animal; Gene Expression Regulation; Humans; Isoenzymes; Male; Mandible; Osteoprotegerin; Periodontitis; RANK Ligand; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Statistics, Nonparametric; Tartrate-Resistant Acid Phosphatase

To investigate the association of polymorphisms in the osteoprotegerin (OPG) and interleukin 1 (IL-1) genes with chronic periodontitis (CP).. One hundred and ninety-four individuals (97 CP patients, 97 controls) were genotyped for the OPG polymorphisms Lys3Asn and Met256Val and for the IL-1 polymorphisms IL-1A (-889C/T) and IL-1B (+3953C/T).. The homozygous variants coding for Lys3 were present at a higher frequency, whereas Asn3 and Met256 were present at a lower frequency in CP patients/controls (Lys3: 31%/25%, Asn3: 23%/32% and Met256: 66%/73%). Heterozygosity for Lys3Asn was observed at a higher frequency in CP patients/controls (46%/43%). Homozygosity for the Val256 genotype was observed in two CP patients (one in controls). Met256Val heterozygosity was more prevalent in CP patients/controls (32%/20%). All differences were statistically not significant between CP patients and controls. In contrast, both IL-1 polymorphisms were statistically significant. The heterozygous variant for IL-1A was present in 32% of the CP patients and in 20% of the controls (homozygosity (patients/controls) CC: 10%/21% and TT: 55%/33%). Heterozygosity for IL-1B was observed in 37% of the CP patients versus 34% in the controls (homozygosity (patients/controls) CC: 26%/57% and TT: 37%/9%).. While the association between the IL-1 polymorphisms and CP was confirmed, no association between the OPG polymorphisms and CP could be found.

Topics: Adult; Alleles; Case-Control Studies; Chronic Disease; DNA Primers; Female; Genotype; Humans; Interleukin-1; Male; Middle Aged; Osteoprotegerin; Periodontitis; Polymorphism, Genetic

To explore certain principle of how osteoprotegerin (OPG) and osteoprotegerin ligand (OPGL) take part in the periodontal tissues remodeling under the combined influence of inflammation and orthodontic force.. The positive signals of OPG and OPGL mRNA were measured with in situ hybridzation after orthodontic tooth movement in the experimental periodontitis groups and control ones.. The OPG and OPGL mRNA expression intensity in the experimental group showed difference from control. All their optical density index reached a peak in day 2, respectively.. OPG and OPGL play important roles in the periodontal reconstruction induced by inflammation irritation and orthodontic force, and complex interaction could exist between the two factors.

Topics: Humans; Osteoprotegerin; Periodontitis; RANK Ligand; RNA, Messenger; Tooth Movement Techniques

Chronic periodontitis (CP) risk is influenced by environmental and genetic factors. Using a case-control design, we tested for associations between CP and selected DNA sequence variations (single nucleotide polymorphisms [SNPs]) in or near genes coding for proteins that play a role in the pathogenesis of this disease.. DNA was analyzed from 219 whites who were examined clinically. Cases (N=137) were >or=35 years of age with eight or more teeth having >or=5 mm of proximal clinical attachment loss. Controls (N=82) were >or=45 years of age with minimal or no proximal attachment loss or pocketing. Nine diallelic polymorphisms (gene and SNP descriptor) were studied in subjects: cytotoxic T-lymphocyte antigen-4 (CTLA-4, 49 A>G), human beta-defensin-1 (DEFB1, 692 G>A), intercellular adhesion molecule-1 (ICAM-1, 1548 A>G), Fas ligand (fasL, -844 C>T), inducible costimulator (ICOS, 3990 G>T), interleukin-6 (IL-6, -174 G>C), cysteine-cysteine chemokine receptor-5 (CCR5, 59653 C>T), osteoprotegerin (OPG, 245 T>G), and osteopontin (OPN, 707 C>T). Genotypes were determined using an automated fluorogenic 5'-nuclease, polymerase chain reaction-based assay. Gender and smoking history (pack-years) were included as covariates in logistic regression analyses.. Heavy smoking (>10 pack-years) and male gender were significantly associated with disease (P<0.001). For all SNPs tested, the allele frequencies and distributions of genotypes did not differ between cases and controls (P>0.05). No unadjusted or adjusted odds ratios (comparing genotypes in cases versus controls) were significantly different than 1.0 (P>0.05) under any additive, dominant, or recessive inheritance model.. None of the SNPs tested were strongly associated with generalized severe chronic periodontitis in North American whites. A potentially more fruitful approach in future studies will be to test for associations between periodontitis and haplotype blocks constructed from either multiple SNPs in candidate gene regions or from panels of markers that span the entire genome.

Topics: Adult; Antigens, CD; Antigens, Differentiation; Antigens, Differentiation, T-Lymphocyte; beta-Defensins; Case-Control Studies; Chronic Disease; CTLA-4 Antigen; Fas Ligand Protein; Female; Genetic Predisposition to Disease; Glycoproteins; Humans; Inducible T-Cell Co-Stimulator Protein; Intercellular Adhesion Molecule-1; Interleukin-6; Logistic Models; Male; Membrane Glycoproteins; Middle Aged; Osteopontin; Osteoprotegerin; Periodontitis; Polymorphism, Single Nucleotide; Receptors, CCR5; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Sialoglycoproteins; Tumor Necrosis Factors

Recent findings have suggested that osteoclastogenesis is directly regulated by receptor activator of nuclear factor-kappa B ligand (RANKL) and its decoy receptor, osteoprotegerin (OPG). However, no studies have described interactions of OPG/RANKL and the gp130 cytokine family in periodontal disease. This study aimed to identify and quantify OPG/RANKL in the gingival crevicular fluid (GCF) and connective tissue of patients with periodontitis, and to clarify possible correlations with disease severity and interleukin-6 (IL-6) cytokines.. Ninety-five sites in 20 patients with generalized chronic periodontitis were divided into four groups by site based on probing depth (PD) and bleeding on probing (BOP). In periodontitis patients, GCF was obtained using sterile paper strips from clinically healthy sites (PD 6 mm with BOP, n = 27). Fourteen clinically healthy sites from four periodontally healthy individuals were used as the control group. The levels of OPG, RANKL and two gp130 cytokines - IL-6 and oncostatin M (OSM) - in the GCF were determined by an enzyme-linked immunosorbent assay (ELISA) and are expressed as total amounts (pg/site). Immunohistochemical localization of OPG- and RANKL-positive cells was also performed on gingival connective tissues harvested from patients with periodontitis (inflammatory group, n = 8 biopsies) and from non-diseased individuals (healthy group, n = 8 biopsies).. GCF RANKL, but not OPG, was elevated in diseased sites of patients with periodontitis. However, the expressions of OPG and RANKL showed no correlation with disease severity (r = 0.174 and 0.056, respectively), but the content of RANKL in the GCF was significantly positively correlated with those of IL-6 (r = 0.207) and OSM (r = 0.231) (p < 0.01). Immunohistochemical staining showed that RANKL-positive cells were significantly distributed in the inflammatory connective tissue zone of diseased gingiva, compared with those of samples from non-diseased persons (p < 0.01). However, few OPG-positive cells were found in connective tissue zones of either the diseased gingiva or healthy biopsies.. These findings imply that in this cross-sectional study of GCF, RANKL, IL-6 and OSM were all prominent in periodontitis sites, whereas OPG was inconsistently found in a few samples of diseased sites but was undetectable in any of the control sites. The results also imply that the expression of RANKL was positively correlated with IL-6 and OSM in the GCF.

Topics: Adult; Analysis of Variance; Carrier Proteins; Case-Control Studies; Chronic Disease; Cytokines; Female; Gingiva; Gingival Crevicular Fluid; Glycoproteins; Humans; Immunohistochemistry; Interleukin-6; Male; Membrane Glycoproteins; Middle Aged; Oncostatin M; Osteoprotegerin; Periodontal Index; Periodontitis; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Statistics, Nonparametric

Receptor activator of nuclear factor-kappaB (RANKL)-mediated osteoclastogenesis plays a pivotal role in inflammatory bone resorption. The aim of this study was to identify the cellular source of RANKL in the bone resorptive lesions of periodontal disease. The concentrations of soluble RANKL, but not its decoy receptor osteoprotegerin, measured in diseased tissue homogenates were significantly higher in diseased gingival tissues than in healthy tissues. Double-color confocal microscopic analyses demonstrated less than 20% of both B cells and T cells expressing RANKL in healthy gingival tissues. By contrast, in the abundant mononuclear cells composed of 45% T cells, 50% B cells, and 5% monocytes in diseased gingival tissues, more than 50 and 90% of T cells and B cells, respectively, expressed RANKL. RANKL production by nonlymphoid cells was not distinctly identified. Lymphocytes isolated from gingival tissues of patients induced differentiation of mature osteoclast cells in a RANKL-dependent manner in vitro. However, similarly isolated peripheral blood B and T cells did not induce osteoclast differentiation, unless they were activated in vitro to express RANKL; emphasizing the osteoclastogenic potential of activated RANKL-expressing lymphocytes in periodontal disease tissue. These results suggest that activated T and B cells can be the cellular source of RANKL for bone resorption in periodontal diseased gingival tissue.

Topics: B-Lymphocytes; Bone Resorption; Carrier Proteins; Cell Differentiation; Cells, Cultured; Gene Expression Regulation; Gingiva; Glycoproteins; Humans; Lymphocyte Activation; Membrane Glycoproteins; Microscopy, Confocal; Osteoclasts; Osteoprotegerin; Periodontitis; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; T-Lymphocytes

Aggressive periodontitis (AgP) is a specific type of periodontal disease that is characterized by rapid attachment loss and bone destruction. While attempting to identify genetic polymorphisms associated with AgP, previous research has focused on candidate genes that may be involved in immune responses to microbial infections. In this study, the focus was on single nucleotide polymorphisms (SNPs) in the key mediators of osteoclast differentiation and activation, which involve receptor activator of nuclear factor-kappaB (RANK), RANK ligand (RANKL) and osteoprotegrin (OPG), in the Japanese population. The aim of this study was to evaluate the association of RANK/RANKL/OPG gene polymorphisms with AgP in the Japanese population.. We examined 99 patients with AgP and 89 controls from the Japanese population to explore the possibility of RANK/RANKL/OPG loci as candidate regions associated with the disease. All exons and relevant exon-intron boundaries of these three candidate genes were amplified by polymerase chain reaction (PCR) using 19 primers, followed by direct sequencing. The polymorphisms were identified by comparing the sequences obtained from 48 subjects.. We identified 27 SNPs in RANK, including 10 novel SNPs and seven SNPs each in both RANKL and OPG. A pairwise linkage disequilibrium analysis using the r2 statistic showed that some SNP pairs from the three loci are in tight linkage disequilibrium.. An association analysis with allelotypes showed that SNPs identified in the RANK/RANKL/OPG genes have no significant association with AgP in the Japanese population.

Topics: Acute Disease; Adolescent; Adult; Alveolar Bone Loss; Base Sequence; Case-Control Studies; Female; Gene Frequency; Humans; Japan; Linkage Disequilibrium; Male; Middle Aged; Osteoclasts; Osteoprotegerin; Periodontitis; Polymerase Chain Reaction; Polymorphism, Single Nucleotide; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B

Actinobacillus actinomycetemcomitans is associated with localized aggressive periodontitis, a disease characterized by rapid loss of the alveolar bone surrounding the teeth. Receptor activator of NF-kappaB Ligand (RANKL) and osteoprotegerin (OPG) are two molecules that regulate osteoclast formation and bone resorption. RANKL induces osteoclast differentiation and activation, whereas OPG blocks this process by acting as a decoy receptor for RANKL. The purpose of this study was to investigate the effect of A. actinomycetemcomitans on the expression of RANKL and OPG in human gingival fibroblasts and periodontal ligament cells. RANKL mRNA expression was induced in both cell types challenged by A. actinomycetemcomitans extract, whereas OPG mRNA expression remained unaffected. Cell surface RANKL protein was also induced by A. actinomycetemcomitans, whereas there was no change in OPG protein secretion. A cytolethal distending toxin (Cdt) gene-knockout strain of A. actinomycetemcomitans did not induce RANKL expression, in contrast to its wild-type strain. Purified Cdt from Haemophilus ducreyi alone, or in combination with extract from the A. actinomycetemcomitans cdt mutant strain, induced RANKL expression. Pretreatment of A. actinomycetemcomitans wild-type extract with Cdt antiserum abolished RANKL expression. In conclusion, A. actinomycetemcomitans induces RANKL expression in periodontal connective tissue cells. Cdt is crucial for this induction and may therefore be involved in the pathological bone resorption during the process of localized aggressive periodontitis.

Topics: Aggregatibacter actinomycetemcomitans; Bacterial Toxins; Bone Resorption; Carrier Proteins; Cells, Cultured; Exotoxins; Fibroblasts; Gene Expression Regulation; Gingiva; Glycoproteins; Humans; Lipopolysaccharides; Membrane Glycoproteins; Osteoprotegerin; Periodontal Ligament; Periodontitis; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; RNA, Messenger

Periodontitis is an inflammatory disease that often leads to destruction of alveolar bone; a number of bacteria in subgingival plaque are associated with bone destruction in periodontitis. To understand the mechanism of how periodontopathogens induce osteoclastogenesis, we determined which mediators are involved in the osteoclastogenesis.. We investigated effects of sonicates from three periodontopathic bacteria, Porphyromonas gingivalis, Treponema denticola, and Treponema socranskii, on osteoclast formation in a co-culture system of mouse calvaria-derived osteoblasts and bone marrow cells. The osteoclast formation was determined by tartrate resistant acid phosphatase (TRAP) staining. The expression of the receptor activator of nuclear factor-kappa B ligand (RANKL), prostaglandin E(2) (PGE(2)) and osteoprotegerin (OPG) in mouse calvaria-derived osteoblasts was determined by immunoassay.. Each bacterial sonicate induced the osteoclast formation in the co-culture system. These bacterial sonicates increased the expression of RANKL and PGE(2), and decreased the expression of OPG in osteoblasts. The addition of OPG, an inhibitor of RANKL, in the co-culture completely suppressed the osteoclastogenesis that was stimulated by each bacterial sonicate. Indomethacin, which is an inhibitor of PGE(2) synthesis, reduced more than 88% of the osteoclast formation induced by each bacterial sonicate. Indomethacin inhibited more than 80% of RANKL expression in osteoblasts induced by T. denticola and T. socranskii, and 59% by P. gingivalis. Indomethacin completely recovered the depression of OPG expression in osteoblasts by T. denticola and T. socranskii to the level of the untreated osteoblasts. Indomethacin recovered the reduction of OPG expression by P. gingivalis to 67%.. These findings suggest that the osteoclastogenesis by P. gingivalis, T. denticola, and T. socranskii is mediated by a RANKL-dependent pathway and that PGE(2) is a main factor in the pathway by the enhancing of RANKL expression and the depression of osteoprotegerin, a RANKL inhibitor.

Topics: Acid Phosphatase; Animals; Carrier Proteins; Cattle; Cell Differentiation; Dinoprostone; Glycoproteins; Indomethacin; Isoenzymes; Membrane Glycoproteins; Mice; NF-kappa B; Osteoblasts; Osteoclasts; Osteoprotegerin; Periodontitis; Porphyromonas gingivalis; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Skull; Statistics, Nonparametric; Tartrate-Resistant Acid Phosphatase; Treponema; Treponema denticola

The receptor activator for NF-kappaB ligand (RANKL) plays an important role in osteoclast formation. A recent study with animal models suggests the involvement of RANKL in the pathogenesis of this periodontal disease. However, no one has examined the level of RANKL in the body fluid of human subjects. This communication reports on the in vivo concentrations of RANKL and the RANKL decoy receptor osteoprotegerin (OPG) in the gingival crevicular fluid (GCF) of periodontal subjects with severe, moderate, and mild forms of the disease. An increased concentration of RANKL and a decreased concentration of OPG were detected in GCF from patients with periodontitis (*p < 0.05 vs. control subjects). The ratio of the concentration of RANKL to that of OPG in the GCF was significantly higher for periodontal disease patients than for healthy subjects (*p < 0.01). Taken together, these data suggest that RANKL and OPG contribute to osteoclastic bone destruction in periodontal disease.. GCF, gingival crevicular fluid; IL, interleukin; OPG, osteoprotegerin; RANKL, receptor activator for NF-kappaB ligand.

Topics: Adult; Bone Resorption; Carrier Proteins; Gingival Crevicular Fluid; Gingival Hemorrhage; Glycoproteins; Humans; Ligands; Membrane Glycoproteins; Middle Aged; NF-kappa B; Osteoclasts; Osteoprotegerin; Periodontal Attachment Loss; Periodontal Pocket; Periodontitis; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Tumor Necrosis Factor-alpha

The effects of the potassium channel (Kv1.3) blocker kaliotoxin on T-cell-mediated periodontal bone resorption were examined in rats. Systemic administration of kaliotoxin abrogated the bone resorption in conjunction with decreased RANKL mRNA expression by T-cells in gingival tissue. This study suggests a plausible therapeutic approach for inflammatory bone resorption by targeting Kv1.3.. Kv1.3 is a critical potassium channel to counterbalance calcium influx at T-cell receptor activation. It is not known if Kv1.3 also regulates RANKL expression by antigen-activated T-cells, and consequently affects in vivo bone resorption mediated by activated T-cells.. Actinobacillus actinomycetemcomitans 29-kDa outer membrane protein-specific Th1-clone cells were used to evaluate the expression of Kv1.3 (using reverse transcriptase-polymerase chain reaction [RT-PCR] and Western blot analyses) and the effects of the potassium channel blocker kaliotoxin (0-100 nM) on T-cell activation parameters ([3H]thymidine incorporation assays and ELISA) and expression of RANKL and osteoprotegerin (OPG; flow cytometry, Western blot, and RT-PCR analyses). A rat periodontal disease model based on the adoptive transfer of activated 29-kDa outer membrane protein-specific Th1 clone cells was used to analyze the effects of kaliotoxin in T-cell-mediated alveolar bone resorption and RANKL and OPG mRNA expression by gingival T-cells. Stimulated 29-kDa outer membrane protein-specific Th1 clone cells were transferred intravenously on day 0 to all animals used in the study (n = 7 animals per group). Ten micrograms of kaliotoxin were injected subcutaneously twice per day on days 0, 1, 2, and 3, after adoptive transfer of the T-cells. The control group of rats was injected with saline as placebo on the same days as injections for the kaliotoxin-treated group. The MOCP-5 osteoclast precursor cell line was used in co-culture studies with fixed 29-kDa outer membrane protein-specific Th1-clone cells to measure T-cell-derived RANKL-mediated effects on osteoclastogenesis and resorption pit formation assays in vitro. Statistical significance was evaluated by Student's t-test.. Kaliotoxin decreased T-cell activation parameters of 29-kDa outer membrane protein-specific Th1 clone cells in vitro and in vivo. Most importantly, kaliotoxin administration resulted in an 84% decrease of the bone resorption induced in the saline-treated control group. T-cells recovered from the gingival tissue of kaliotoxin-treated rats displayed lower ratios of RANKL and OPG mRNA expression than those recovered from the control group. The ratio of RANKL and osteoprotegerin protein expression and induction of RANKL-dependent osteoclastogenesis by the activated T-cells were also markedly decreased after kaliotoxin treatments in vitro.. The use of kaliotoxin or other means to block Kv1.3 may constitute a potential intervention therapy to prevent alveolar bone loss in periodontal disease.

Topics: Acid Phosphatase; Adoptive Transfer; Aggregatibacter actinomycetemcomitans; Alveolar Bone Loss; Animals; Antigen Presentation; Bacterial Outer Membrane Proteins; Blotting, Western; Carrier Proteins; CD3 Complex; Cell Differentiation; Coculture Techniques; Down-Regulation; Female; Gene Expression; Glycoproteins; Immunoglobulin G; Interferon-gamma; Isoenzymes; Kv1.3 Potassium Channel; Lipopolysaccharides; Lymphocyte Activation; Maxilla; Membrane Glycoproteins; Osteoclasts; Osteoprotegerin; Periodontitis; Potassium Channels; Potassium Channels, Voltage-Gated; RANK Ligand; Rats; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Scorpion Venoms; Spleen; T-Lymphocytes; Tartrate-Resistant Acid Phosphatase

Periodontitis is a complex, multifactorial process affected by bacterial plaque-components and host defense mechanisms. Inflammation of the periodontitium may lead the destruction of the underlying ligament and alveolar bone. Receptor activator of NF-kappaB ligand (RANKL), a novel TNF receptor-related protein is an important factor for osteoclast differentiation and activation. Given osteolysis by osteoclast has been demonstrated in periodontitis, we hypothesized that RANKL expression may be associated with bone destruction in periodontitis. We used semi-quantitative RT-PCR to compare the gene expression of RANKL and osteoprogerin (OPG), a decoy receptor of RANKL, between moderate and advanced periodontitis, and healthy subjects. The level of RANKL mRNA was highest in advanced periodontitis. In contrast, the level of OPG mRNA in both advanced and moderate periodontitis was lower than that in the healthy group. It appears that the ratio of RANKL to OPG mRNA in periodontitis has increased. To determine the localization of RANKL gene transcripts in gingival tissue at the cellular level, in situ hybridization was performed using digoxigenin-labeled specific riboprobes. RANKL mRNA was expressed in inflammatory cells, mainly lymphocyte and macrophages. In addition, proliferating epithelium in the vicinity of inflammatory cells expressed high levels of RANKL mRNA. In short, our data suggest that up regulation of RANKL mRNA in both inflammatory cells and epithelium may be associated with the activation of osteoclastic bone destruction in periodontitis.

Topics: Adult; Aged; Bone Diseases; Carrier Proteins; Gingiva; Glycoproteins; Humans; In Situ Hybridization; Membrane Glycoproteins; Middle Aged; Osteoprotegerin; Periodontitis; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Reference Values; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Transcription, Genetic

This study investigated the expression of key mediators that regulate differentiation of osteoclasts, receptor activator of nuclear factor kappaB ligand (RANKL), and its natural inhibitor, osteoprotegerin (OPG), in periodontitis. We aimed to compare the levels of the RANKL and OPG in the granulomatous tissue adjacent to areas of alveolar bone loss from patients with periodontitis to that present in tissue from patients without periodontitis. In addition, we aimed to determine the types of cells expressing these factors in these tissues and to demonstrate the expression of the osteoclastic markers, RANK and tartrate-resistant acid phosphatase (TRAP), in periodontitis.. Frozen biopsy specimens were analysed using specific monoclonal antibodies and were evaluated by semiquantitative analysis and digital image analysis to compare levels of RANKL and OPG protein expression. Double labelling of frozen sections with antibodies to different cell lineage specific markers was used to determine the types of cells expressing these proteins. In situ hybridization was used to detect cells expressing RANK mRNA.. Semiquantitative image analysis demonstrated that significantly higher levels of RANKL protein (P < 0.05) were expressed in the periodontitis tissue. Conversely, OPG protein was significantly lower (P < 0.05) in the periodontitis tissues. RANKL protein was associated with lymphocytes and macrophages. OPG protein was associated with endothelial cells in both tissues. Many leukocytes expressing RANK mRNA and TRAP were observed in periodontitis tissues.. The change in the levels of these key regulators of osteoclast differentiation may play a major role in the bone loss seen in periodontitis.

Topics: Acid Phosphatase; Adolescent; Adult; Aged; Alveolar Bone Loss; Biomarkers; Carrier Proteins; Cell Differentiation; Endothelium, Vascular; Female; Gene Expression Regulation; Glycoproteins; Humans; Isoenzymes; Leukocytes, Mononuclear; Ligands; Male; Membrane Glycoproteins; Middle Aged; NF-kappa B; Osteoclasts; Osteoprotegerin; Periodontitis; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Tartrate-Resistant Acid Phosphatase

Periodontitis is an inflammatory bone disease caused by Gram-negative anaerobic bacteria, but the precise mechanism of bone destruction remains unknown. Activated T lymphocytes secrete receptor activator of NF-kappaB ligand (RANKL) and support the differentiation of monocytes into mature osteoclasts. The purpose of this study was to examine the expression of RANKL and its inhibitor, osteoprotegerin (OPG), in inflamed gingival tissue and to clarify the role of human gingival fibroblasts (HGFs) in osteoclastogenesis regulated by RANKL. HGFs and gingival mononuclear cells (GMCs) were obtained from chronic periodontitis patients during routine periodontal surgery. Expression of OPG and RANKL mRNA in gingival tissue and HGFs was examined with RT-PCR. OPG production was measured using ELISA. Expression of RANKL, CD4, CD8 and CD69 on GMCs was determined by flow-cytometry using RANK-Fc fusion protein and the respective monoclonal antibodies. Osteoclastogenesis by RANKL was assayed by counting the number of tartarate-resistant acid phosphatase (TRAP)-positive cells after culturing human peripheral blood monocytes with recombinant human RANKL and macrophage-colony stimulating factor (M-CSF) for 10 days. OPG and RANKL mRNA were expressed in 80% (16/20) and 25% (5/20) of periodontitis lesions, respectively. OPG, but not RANKL, mRNA was expressed within HGFs. OPG mRNA expression and production by HGFs was augmented by LPS stimulation. All GMC samples expressed CD69, and two of five GMC samples expressed RANKL. The culture supernatant of LPS-stimulated gingival fibroblasts significantly reduced the number of TRAP positive cells generated by culturing monocytes with RANKL and M-CSF. The present study suggests that LPS-stimulated HGFs inhibit monocyte differentiation into osteoclasts through the production of OPG.

Topics: Antigens, CD; Antigens, Differentiation, T-Lymphocyte; Carrier Proteins; Cell Differentiation; Cells, Cultured; Chronic Disease; Culture Media, Conditioned; Fibroblasts; Gingiva; Glycoproteins; Humans; Kinetics; Lectins, C-Type; Lipopolysaccharides; Membrane Glycoproteins; Monocytes; Osteoclasts; Osteoprotegerin; Periodontitis; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; RNA, Messenger; Stem Cells

Periodontitis, a prime cause of tooth loss in humans, is implicated in the increased risk of systemic diseases such as heart failure, stroke, and bacterial pneumonia. The mechanisms by which periodontitis and antibacterial immunity lead to alveolar bone and tooth loss are poorly understood. To study the human immune response to specific periodontal infections, we transplanted human peripheral blood lymphocytes (HuPBLs) from periodontitis patients into NOD/SCID mice. Oral challenge of HuPBL-NOD/SCID mice with Actinobacillus actinomycetemcomitans, a well-known Gram-negative anaerobic microorganism that causes human periodontitis, activates human CD4(+) T cells in the periodontium and triggers local alveolar bone destruction. Human CD4(+) T cells, but not CD8(+) T cells or B cells, are identified as essential mediators of alveolar bone destruction. Stimulation of CD4(+) T cells by A. actinomycetemcomitans induces production of osteoprotegerin ligand (OPG-L), a key modulator of osteoclastogenesis and osteoclast activation. In vivo inhibition of OPG-L function with the decoy receptor OPG diminishes alveolar bone destruction and reduces the number of periodontal osteoclasts after microbial challenge. These data imply that the molecular explanation for alveolar bone destruction observed in periodontal infections is mediated by microorganism-triggered induction of OPG-L expression on CD4(+) T cells and the consequent activation of osteoclasts. Inhibition of OPG-L may thus have therapeutic value to prevent alveolar bone and/or tooth loss in human periodontitis.

Topics: Adult; Aggregatibacter actinomycetemcomitans; Alveolar Bone Loss; Animals; Bacterial Proteins; Carrier Proteins; CD4-Positive T-Lymphocytes; Disease Models, Animal; Female; Glycoproteins; Histocytochemistry; Humans; Lymphocyte Activation; Male; Membrane Glycoproteins; Mice; Mice, Inbred BALB C; Mice, Inbred NOD; Mice, SCID; Osteoclasts; Osteoprotegerin; Periodontitis; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; RNA-Binding Proteins; Transcription Factors