In vitro testing the potential of a novel chimeric IgG variant for inhibiting collagen fibrils formation in recurrent hereditary gingival fibromatosis: chimeric antibody in a gingival model

Gingival fibromatosis is a progressive enlargement of the gingiva. It may hinder oral cavity hygiene and result in underlying bone loss. The long-term benefits of surgery cannot be predicted. On the other hand, alternative, efficient and non-invasive methods are not available at present. The aim of this study was to test the inhibitory effects of a chimeric IgG variant on collagen fibril formation in the cell culture of gingival fibroblasts taken from a patient with hereditary gingival fibromatosis with a high propensity for recurrence. Gingival biopsies were collected from the mandibular gingiva and used for histological evaluation as well as to establish a fibroblast culture. A histological evaluation was made in haematoxylin-eosin and Heidenhain's trichrome stained tissue sections. The inhibitory effect of a chimeric antibody on collagen fibril formation was determined in fibroblast cultures by using a collagen-specific Western blot and immunofluorescent staining. A histological evaluation revealed epithelial acanthosis with singular elongated rete pegs extending into the underlying connective tissue stroma that consisted of locally abundant, irregular collagen bundles. Based on observations with an in vitro model we conclude that a chimeric anti-collagen antibody efficiently inhibits collagen fibril accumulation in cell culture derived from diffuse, hereditary gingival fibromatosis that is characterized by a high propensity for recurrence (high proliferation index). Employing cell cultures from standardized group of patients with recurrent hereditary gingival fibromatosis as well as standarizing relevant 3D (tissue-like) models will be crucial for further tests of the antibody

BET bromodomain inhibitors suppress inflammatory activation of gingival fibroblasts and epithelial cells from periodontitis patients

BET bromodomain proteins are important epigenetic regulators of gene expression that bind acetylated histone tails and regulate the formation of acetylation-dependent chromatin complexes. BET inhibitors suppress inflammatory responses in multiple cell types and animal models, and protect against bone loss in experimental periodontitis in mice. Here, we analyzed the role of BET proteins in inflammatory activation of gingival fibroblasts (GFs) and gingival epithelial cells (GECs). We show that the BET inhibitors I-BET151 and JQ1 significantly reduced expression and/or production of distinct, but overlapping, profiles of cytokine-inducible mediators of inflammation and bone resorption in GFs from healthy donors (IL6, IL8, IL1B, CCL2, CCL5, COX2, and MMP3) and the GEC line TIGK (IL6, IL8, IL1B, CXCL10, MMP9) without affecting cell viability. Activation of mitogen-activated protein kinase and nuclear factor-κB pathways was unaffected by I-BET151, as was the histone acetylation status, and new protein synthesis was not required for the anti-inflammatory effects of BET inhibition. I-BET151 and JQ1 also suppressed expression of inflammatory cytokines, chemokines, and osteoclastogenic mediators in GFs and TIGKs infected with the key periodontal pathogen Porphyromonas gingivalis. Notably, P. gingivalis internalization and intracellular survival in GFs and TIGKs remained unaffected by BET inhibitors. Finally, inhibition of BET proteins significantly reduced P. gingivalis-induced inflammatory mediator expression in GECs and GFs from patients with periodontitis. Our results demonstrate that BET inhibitors may block the excessive inflammatory mediator production by resident cells of the gingival tissue and identify the BET family of epigenetic reader proteins as a potential therapeutic target in the treatment of periodontal disease

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Association of distinct fine specificities of anti-citrullinated peptide antibodies with elevated immune responses to Prevotella intermedia in a subgroup of patients with rheumatoid arthritis and periodontitis

Objective In addition to the long-established link with smoking, periodontitis (PD) is also a risk factor for rheumatoid arthritis (RA). To elucidate the mechanism by which PD could induce antibodies to citrullinated peptides (ACPA), we examine the antibody response to a novel citrullinated peptide from cytokeratin type I 13 identified in gingival crevicular fluid (GCF), and compare the response to 4 other citrullinated peptides in patients with RA, well-characterized for PD and smoking. Methods The citrullinomes of GCF and periodontal tissue from people with PD were mapped by mass spectrometry. Antibodies to citrullinated peptides from cytokeratin type I 13 (cCK13), tenascin-C (cTNC5), vimentin (cVIM), enolase (CEP-1) and fibrinogen β (cFIBβ) were examined by ELISA in patients with RA (n=287) and osteoarthritis (OA) (n=330), and cross-reactivity assessed by inhibition assays. Results A novel citrullinated peptide cCK13-1 (444TSNASGR-cit-TSDV-cit-RP458) identified in GCF, exhibited elevated antibody responses in RA patients (24%). Anti-cCK13-1 antibodies correlated with anti-cTNC5 antibodies, and absorption experiments confirmed this was not due to cross-reactivity. Only anti-cCK13-1 and anti-cTNC5 were associated with antibodies to the periodontal pathogen Prevotella intermedia (p=0.05 and p =0.001 respectively), but not with antibodies to Porphyromonas gingivalis arginine gingipains. Antibodies to CEP-1, cFIBβ and cVIM correlated with each other, and with smoking and shared epitope risk factors in RA. Conclusion This study identifies two groups of ACPA fine specificities associated with different RA risk factors; one predominantly linked to smoking and shared epitope, the other linking anti- cTNC5 and cCK13-1 to infection with the periodontal pathogen P. intermedia

Peptidylarginine deiminase from Porphyromonas gingivalis contributes to infection of gingival fibroblasts and induction of prostaglandin E_{2}-signaling pathway

Porphyromonas gingivalis (Pg) expresses the enzyme peptidylarginine deiminase (PPAD), which has a strong preference for C-terminal arginines. Due to the combined activity of PPAD and Arg-specific gingipains, Pg on the cell surface is highly citrullinated. To investigate the contribution of PPAD to the interaction of Pg with primary human gingival fibroblasts (PHGF) and Pg-induced synthesis of prostaglandin E2 (PGE2), PHGF were infected with wild-type Pg ATCC 33277, an isogenic PPAD-knockout strain (Δppad) or a mutated strain (C351A) expressing an inactive enzyme in which the catalytic cysteine has been mutated to alanine (PPAD(C351A)). Cells were infected in medium containing the mutants alone or in medium supplemented with purified, active PPAD. PHGF infection was assessed by colony-forming assay, microscopic analysis and flow cytometry. Expression of COX-2 and mPGES-1, key factors in the prostaglandin synthesis pathway, was examined by qRT-PCR, while PGE2 synthesis was evaluated by EIA. PHGF were infected more efficiently by wt-Pg than the Δppad strain, which correlated with strong induction of COX-2 and mPGES-1 expression by wt-Pg, but not by the PPAD activity-null mutant strains (ΔPPAD and C351A). The impaired ability of the ΔPPAD strain to adhere to and/or invade PHGF and both ΔPPAD and C351A to stimulate the PGE2-synthesis pathway was fully restored by the addition of purified PPAD. The latter effect was strongly inhibited by aspirin. Collectively, our results implicate PPAD activity, but not PPAD itself, as an important factor for gingival fibroblast infection and activation of PGE2 synthesis, the latter of which may strongly contribute to bone resorption and eventual tooth loss

EFP Delphi study on the trends in Periodontology and Periodontics in Europe for the year 2025

Aim The aim was to assess the potential trends in Periodontology and Periodontics in Europe that might be anticipated by the year 2025, using the Delphi method. Material and Methods The expert opinion of 120 experts was sought through the use of an open-ended questionnaire, developed by an advisory group, containing 40 questions concerning the various trends in periodontology. Results The experts (113 responders) expect a stabilization of the prevalence of periodontitis, both for the chronic as well as the aggressive cases, but an increase in implant-related diseases up to the year 2025. Concurrently, the importance of implants is seen to be increasing. They foresee an increased demand for postgraduate periodontology and implantology training. This is mirrored in an increase in publications for implant dentistry and increase in demand and need for training. Concerning the patients, better-informed individuals seeking more routine check-ups are expected. Conclusion A continued need for specialized periodontists, but also well trained dental practitioners is foreseen for next decade in Europe. Apart from periodontology they will be increasingly exposed to and trained in implant dentistry. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd

Association of distinct fine specificities of anti-citrullinated peptide antibodies with elevated immune responses to prevotella intermedia in a subgroup of patients with rheumatoid arthritis and periodontitis

In addition to the long-established link with smoking, periodontitis (PD) is a risk factor for rheumatoid arthritis (RA). This study was undertaken to elucidate the mechanism by which PD could induce antibodies to citrullinated peptides (ACPAs), by examining the antibody response to a novel citrullinated peptide of cytokeratin 13 (CK-13) identified in gingival crevicular fluid (GCF), and comparing the response to 4 other citrullinated peptides in patients with RA who were well-characterized for PD and smoking.The citrullinomes of GCF and periodontal tissue from patients with PD were mapped by mass spectrometry. ACPAs of CK13 (cCK13), tenascin-C (cTNC5), vimentin (cVIM), α-enolase (CEP-1), and fibrinogen β (cFIBβ) were examined by enzyme-linked immunosorbent assay in patients with RA (n = 287) and patients with osteoarthritis (n = 330), and cross-reactivity was assessed by inhibition assays.A novel citrullinated peptide cCK13-1 (444 TSNASGR-Cit-TSDV-Cit-RP458 ) identified in GCF exhibited elevated antibody responses in RA patients (24%). Anti-cCK13-1 antibody levels correlated with anti-cTNC5 antibody levels, and absorption experiments confirmed this was not due to cross-reactivity. Only anti-cCK13-1 and anti-cTNC5 were associated with antibodies to the periodontal pathogen Prevotella intermedia (P = 0.05 and P = 0.001, respectively), but not with antibodies to Porphyromonas gingivalis arginine gingipains. Levels of antibodies to CEP-1, cFIBβ, and cVIM correlated with each other, and with smoking and shared epitope risk factors in RA.This study identifies 2 groups of ACPA fine specificities associated with different RA risk factors. One is predominantly linked to smoking and shared epitope, and the other links anti-cTNC5 and cCK13-1 to infection with the periodontal pathogen P intermedia