Targeting Atp6v1c1 Prevents Inflammation and Bone Erosion Caused by Periodontitis and Reveals Its Critical Function in Osteoimmunology.

Periodontal disease (Periodontitis) is a serious disease that affects a majority of adult Americans and is associated with other systemic diseases, including diabetes, rheumatoid arthritis, and other inflammatory diseases. While great efforts have been devoted toward understanding the pathogenesis of periodontitis, there remains a pressing need for developing potent therapeutic strategies for targeting this pervasive and destructive disease. In this study, we utilized novel adeno-associated virus (AAV)-mediated Atp6v1c1 knockdown gene therapy to treat bone erosion and inflammatory caused by periodontitis in mouse model. Atp6v1c1 is a subunit of the V-ATPase complex and regulator of the assembly of the V0 and V1 domains of the V-ATPase complex. We demonstrated previously that Atp6v1c1 has an essential function in osteoclast mediated bone resorption. We hypothesized that Atp6v1c1 may be an ideal target to prevent the bone erosion and inflammation caused by periodontitis. To test the hypothesis, we employed AAV RNAi knockdown of Atp6v1c1 gene expression to prevent bone erosion and gingival inflammation simultaneously. We found that lesion-specific injection of AAV-shRNA-Atp6v1c1 into the periodontal disease lesions protected against bone erosion (>85%) and gingival inflammation caused by P. gingivalis W50 infection. AAV-mediated Atp6v1c1 knockdown dramatically reduced osteoclast numbers and inhibited the infiltration of dendritic cells and macrophages in the bacteria-induced inflammatory lesions in periodontitis. Silencing of Atp6v1c1 expression also prevented the expressions of osteoclast-related genes and pro-inflammatory cytokine genes. Our data suggests that AAV-shRNA-Atp6v1c1 treatment can significantly attenuate the bone erosion and inflammation caused by periodontitis, indicating the dual function of AAV-shRNA-Atp6v1c1 as an inhibitor of bone erosion mediated by osteoclasts, and as an inhibitor of inflammation through down-regulation of pro-inflammatory cytokine expression. This study demonstrated that Atp6v1c1 RNAi knockdown gene therapy mediated by AAV-shRNA-Atp6v1c1 is a promising novel therapeutic approach for the treatment of bone erosion and inflammatory related diseases, such as periodontitis and rheumatoid arthritis.

Immunohistological expression of human ß-defensin-1 and human ß-defensin-2 in exacerbation of acute and secondary chronic osteomyelitis of the mandible.

BACKGROUND: The majority of patients diagnosed with osteomyelitis of the jaw have severe complaints. Unfortunately, the pathogenesis still remains unclear. Human ß-defensins expressed in epithelial and bone tissues as a part of the innate immunity may be involved in disease development. In this study, we hypothesize that expression levels of human ß-defensin-1 and -2 in the acute and secondary chronic osteomyelitis may be altered in comparison with healthy bone and with bisphosphonate-associated necrosis as well as irradiation from a previous study. METHODS: Bone samples were collected during surgical debridement in a total of eight patients suffering from acute or secondary chronic osteomyelitis of the jaw. Expression levels of hBD-1 and -2 were quantified and related to non-stained cells. Ratios were compared by one-way ANOVA and multiple tests by Holm-Bonferroni. RESULTS: Multiple testing revealed no significant differences for expression levels of human ß-defensin-1 between all groups, whereas labeling index of human ß-defensin-2 was significantly different between specimens of bisphosphonate-associated osteonecrosis of the jaws and all other groups. No significant difference occurred between samples of floride osteomyelitis and healthy bone for expression of hBD-1 and -2. CONCLUSIONS: Although the affected patients showed all clinical signs of acute inflammation, expression levels in acute and secondary chronic osteomyelitis in the jaws did not reveal statistically significant differences compared with healthy bone samples. The weak immunological host response in terms of a putative genetically predisposition should be further discussed as pathogenesis factor for osteomyelitis in the future.

T-cells and B-cells in osteoporosis.

PURPOSE OF REVIEW: Bone disease is a leading cause of fractures and continues to be a source of significant morbidity and mortality worldwide. As the underlying mechanisms of osteoporosis are elucidated, immune dysfunction continues to emerge as a key precipitating factor in multiple bone disease contexts. This review examines recent findings in the osteoimmunology field and their implications for bone disease and for novel future therapeutic approaches to rejuvenate the skeleton. RECENT FINDINGS: T-cells and B-cells have long been recognized to play important roles in the etiology of inflammatory bone disease; however, new findings continue to challenge our understanding of the depth of the immuno-skeletal interface. In this review, we examine recent evidence for new roles of B-cells in oestrogen deficiency bone loss; central actions of interleukin-7 in the cause of T-cell mediated tissue destruction in rheumatoid arthritis; novel RANKL-independent alveolar bone loss in periodontal infection; and a putative role for γδ T-cells in bisphosphonate-associated osteonecrosis of the jaw. Finally, evidence for novel bone anabolic activities mediated through T-cells by the CD28 antagonist CTLA-4Ig and by intermittently administered parathyroid hormone are examined. SUMMARY: As the field of osteoimmunology continues to mature, new interrelationships between immune cells and bone turnover continue to emerge.

The expression of macrophage migration inhibitory factor is correlated with receptor activator of nuclear factor kappa B ligand in induced rat periapical lesions.

INTRODUCTION: Macrophage migration inhibitory factor (MIF) has been defined as a key cytokine in regulation of innate and adaptive immunity. The purpose of this study was to investigate the immunohistochemical localization of MIF and its relationship with receptor activator of nuclear factor kappa B ligand (RANKL) protein during the development of periapical lesions in rats. METHODS: Apical periodontitis was induced in Wistar rats by occlusal pulp exposure in mandibular first molar teeth. The animals were randomly killed at 0, 7, 14, 21, 28, and 35 days after pulp exposure. The jaws that contained the first molar were obtained and were prepared for histologic analysis, enzyme histochemistry, immunohistochemistry, and double immunofluorescence staining. RESULTS: From day 0 to day 35, the areas of periapical bone loss increased and seemed to be stabilized on day 35. A few MIF-positive and RANKL-positive cells and osteoclasts could be observed on day 7, and all climaxed on day 14. From day 21 to day 35, the expression of MIF and RANKL protein decreased, and fewer osteoclasts could be observed. CONCLUSIONS: These findings showed that MIF might be associated with the differentiation of osteoclasts in the periapical lesions. MIF contributes to the pathogenesis of the periapical lesions through the induction of RANKL protein.

A novel ex vivo culture model for inflammatory bone destruction.

Pathological alterations in the balance of bone metabolism are central to the progression of inflammatory bone diseases such as periodontal disease. We have developed and characterized a novel ex vivo murine mandible model of inflammatory bone destruction. Slices of mandible were cultured for 14 days in the presence or absence of P. gingivalis lipopolysaccharide (LPS) or pro-inflammatory cytokines. Following culture, cell viability and tissue histomorphometry were assessed with quantification of matrix proteins, resident osteoclasts, ligament cells, monocytes, macrophages, and neutrophils. In the absence of inflammatory factors, culture viability, osteoclasts, and matrix components were maintained. LPS or TNFα stimulation demonstrated an increase in cellular proliferation, monocyte cells, osteoclast differentiation, and matrix degradation. Pathophysiological bone metabolism can be induced via exposure to LPS and direct influence of TNFα within the model despite the absence of systemic circulation, providing a model for inflammatory bone destruction and investigation of the effects of novel therapeutics.

Bisphosphonates-related osteonecrosis of the jaws: a preliminary study of salivary interleukins.

OBJECTIVE: The aim of this preliminary study was analyze the possible alterations in some salivary interleukins, usually associated with the inflammatory processes. MATERIAL AND METHODS: The study comprised three groups: group 1, with 26 cases with bisphosphonates-related osteonecrosis of the jaws (BRONJ). Group 2, with 29 patients who had received iBF but without BRONJ. Group 3, with 26 control patients not treated with BF and without oral lesions. We collected unstimulated whole saliva in all groups. A semiquantitative study was performed based on a cytokine array panel. We used the proteome profiler array for the study. We analyzed: Interleukin 1 alpha (IL-1α), interleukin-1 receptor antagonist (IL-1RA), and interleukin 1 beta (IL-1ß). RESULTS: We found higher salivary values for all the cytokines studied in group 1 than in group 2 and 3. IL-1ß showed the major differences compared with control group. (P < 0.05) CONCLUSIONS: This preliminary study confirms that there are alterations in these interleukins in patients with BRONJ. These results give support to further additional salivary studies on these biomarkers by quantitative measures.

Mandibular mucormycosis in immunocompromised patients: report of 2 cases and review of the literature.

Mucormycosis, also known as zygomycosis, is an opportunistic fungal infection caused by a series of fungi in the Mucorales family in people with immune disorders. It is harmless to a healthy person, but when it has invaded the internal organs, it is frequently fatal in immunocompromised patients. It is known for having a very poor prognosis; however, with aggressive medical and surgical management, survival rates are currently thought to exceed 80%. It has 7 predominant clinical forms: rhinocerebral, pulmonary, cutaneous, gastrointestinal, central nervous system, disseminated, and, rarely, miscellaneous (ie, bone, kidney, cardiac, mediastinum, oral). Although oral involvement of this condition has been reported relatively frequently in the literature, mandibular involvement is a rarer condition than oral involvement. The purpose of this article is to report the treatment of isolated cases of mandibular mucormycosis and a review of the literature.

Interleukin-17: a new paradigm in inflammation, autoimmunity, and therapy.

Chronic diseases, such as periodontal disease (PD) and rheumatoid arthritis (RA), are characterized by a robust immune response resulting in unresolved inflammation. Inflammation is mediated by proinflammatory cytokines; recently, a novel subset of T-helper (Th) cells was identified that plays a crucial role in inflammation and autoimmune disease. This population secretes several proinflammatory cytokines, including the novel cytokine interleukin (IL)-17, and, hence, has been termed "Th17." Inflammatory cytokines are implicated in the progression of localized chronic infections, such as PD, and in serious systemic pathologies, such as diabetes, chronic obstructive pulmonary disease, and cardiovascular disease. IL-17 mediates inflammation through a receptor (IL-17R) composed of two subunits, IL-17RA and IL-17RC. Drugs that antagonize inflammatory cytokines are used therapeutically to downregulate immune-mediated pathology in conditions such as RA, although not all patients respond well to this approach. Therefore, identification of potential novel therapeutic targets, such as the IL-17 signaling complex, may be clinically relevant for mitigating inflammatory pathology. However, the manner in which such a therapeutic may influence the onset and progression of PD is poorly understood. Therapeutics that antagonize inflammatory cytokines ameliorate inflammation and bone loss and may have broader implications for individuals with systemic diseases in which inflammation and autoimmunity predominate.

Glandular odontogenic cyst in China: report of 12 cases and immunohistochemical study.

OBJECTIVE: The purpose of this study was to present 12 additional cases of glandular odontogenic cyst (GOC) in the Department of Oral Pathology, School of Stomatology, Wuhan University, People's Republic of China, and to investigate their immunohistochemical cytokeratins (CKs) expression in the epithelial components. METHODS: A total of 12 GOCs were reviewed clinically and radiographically, and immunohistologic CKs AE1, 7, 8/18, 10/13, 14, 16, 19 and 20 were performed by using a standard biotin-streptavidin immunoperoxidase technique on paraffin sections. RESULTS: The present series showed that eight occurred in males and four in females. The mean age was 37.6 years with a peak incidence occurring in the third decades (six of 12). Mandibles were more affected than maxillas (7:5), especially anterior mandible (four of seven). Radiographically, ratio multilocular to unilocular radiolucencies was 5:7 usually with well-defined borders. Histologically, cystic spaces were lined by non-keratinized stratified epithelia containing focal plaque-like or whirlpool-like thickenings; surface epithelial layer-containing eosinophilic cuboidal cells; mucous cells; and mucin pools of microcystic areas in the epithelium. Immunohistochemistry showed that epithelium of GOCs stained for CKs AE1, 7, 8/18, 10/13, 14 and 19 with slight changes in their patterns, and no reaction to CKs 16 and 20. CONCLUSIONS: Most clinical and histologic features in this study were analogous to those reported west population, although with slight difference between them. Histologically, the morphology of the epithelium strongly suggested an odontogenic origin, and CKs expression of GOC was similar to that of odontogenic epithelium, suggesting histochemically that GOC might be derived from odontogenic epithelium.

Systemic leukocyte activation in patients with central giant cell lesions.

BACKGROUND: Central giant cell lesion (CGCL) is a reactive lesion of the jaws with an associated inflammatory infiltrate. Since cell circulation allows for intense communication between different compartments in the body, we investigated whether the CGCL would lead to phenotypic and/or functional changes in circulating leukocytes. METHODS: We obtained lymphocytes and monocytes from CGCL patients and control subjects, to evaluate cytokine and adhesion molecule expression using flow cytometry. RESULTS: Our results revealed that CD4(+) T cells and CD14(+) monocytes from CGCL express elevated levels of CD11a and CD11b, respectively, when compared with controls. The frequencies of CD4(+) T cells expressing interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha and the frequencies of CD4(+) and CD14(+) cells expressing interleukin (IL)-10 were increased in CGCL group, when compared with controls. CONCLUSIONS: Our data indicate that, although CGCL is a localized lesion, the patients show systemic functional alterations in circulating leukocytes, suggesting their role in the inflammatory pathogenesis of CGCL.

The aggressive nature of the odontogenic keratocyst: is it a benign cystic neoplasm? Part 1. Clinical and early experimental evidence of aggressive behaviour.

In this, the first of three articles on the aggressive nature of the odontogenic keratocyst (OKC), there is a review of clinical and histological observations which indicated that this was an aggressive lesion with a predilection for recurrence unlike the majority of other jaw cysts. This led to the tentative suggestion that the OKC might be a benign neoplasm. Subsequently there were early laboratory investigations that compared proliferation rates of the OKC epithelium with other jaw cysts, comparative enzyme histochemistry to assess aspects of its metabolism and markers that would enable accurate presurgical diagnosis of this cyst. Comparative studies were also pursued on the walls of the OKC and other jaw cysts to identify factors that might influence the capacity of the OKC to resorb the bone surrounding it. The clinical and laboratory studies reviewed in this section provided cogent presumptive evidence of the distinctively aggressive nature of the OKC that led numbers of investigators to pursue immunocytochemical and genetic studies on this cyst. Parts 2 and 3 of this series review this work.

[Ozone therapy of chronic mandibular osteomyelitis]. / Ozonoterapiia khronicheskikh osteomielitov nizhnei cheliusti.

Clinical picture, bacterial passage, and immune status were studied in patients with chronic traumatic and chronic odontogenic mandibular osteomyelitis. The deepest disorders of biocenosis and the highest incidence of immunodeficiencies were observed in patients with chronic odontogenic osteomyelitis. Local and total ozone therapy is suggested for antibacterial and immunomodulating treatment. Medical ozone exposure promoted more complete and rapid normalization of nonspecific resistance and T-cellular immunity, thus accelerating clinical cure and reducing the incidence of complications.

[Efficiency of immune correction in patients with chronic traumatic mandibular osteomyelitis]. / Osobennosti immunnykh rasstroistv i éffektivnost' ikh korrektsii u bol'nykh s khronicheskim travmaticheskim osteomielitom nizhnei cheliusti.

The effect of a new immunomodulator neovir was studied in 35 patients with chronic traumatic mandibular osteomyelitis. The immune status and clinical parameters notably improved.

Antibody response in patients with osteomyelitis of the mandible.

Patients with mandibular osteomyelitis had quantification of 10 antibodies against certain bacterial proteins and polysaccharides. Sera from 31 patients with acute or chronic osteomyelitis of the mandible and from 17 healthy controls were analyzed. Some patients showed low levels of investigated antibodies in general and a lack of specific antiteichoic acid antibodies, as well as of different antipneumococcal antibodies particularly. Two patients with therapy-resistant osteomyelitis showed IgG2 and IgG3 subclass deficiency. They had replacement therapy with intravenous 10 or 15 gm immunoglobulin every 3 weeks for 6 months. Both patients showed considerable improvement in their clinical symptoms after treatment with immunoglobulin. This study indicates that impaired humoral immune response may be of importance in subgroups of patients with osteomyelitis of the mandible.

Chronic sclerosing osteomyelitis of the mandible in monozygotic twins.

Identical female twins with chronic sclerosing osteomyelitis of the mandible are presented. The diagnoses of both at the age of 12 years were based on typical history, and on clinical, radiographic, and histologic findings. High concentrations of IgA and IgG were detected in the serum of both patients, but deviations were not observed in other immunologic variables. The normally commensal organism, Propionibacterium acnes grew from a bone biopsy specimen from the mandible of one twin. No oral focus of the disease was confirmed in either case. We suggest that hereditary factors must have played a role in the pathogenesis of these cases of chronic osteomyelitis.