Proteoglycan and collagen in porcine gingivae

The sequential extractability of uronic acid containing macromolecules, proteoglycans (mucopolysaccharides), from pig gingivae under associative and dissociative aqueous conditions has been investigated. Some of the macromolecular material thus extracted formed highly insoluble precipitates following dialysis against 0.1 M-sodium acetate. Both soluble and insoluble fractions from associative and dissociative extraction regimes were assayed for uronic acid. The residual glycosaminoglycan in the tissue was assayed following papain digestion of the tissue. The limitation of assay reproducibility for various sized source tissue indicates that at least 100 mg dry weight of gingivae is required. When epithelium was removed from the underlying gingival connective tissue, the reproducibility of hydroxyproline estimation was improved. These data emphasize that the epithelium contributes an uncontrollable variable to the basic dry weights of gingivae as a whole against which such measurements as collagen content may be assessed. Furthermore, the data generated from sequential extraction of macromolecular uronates from pig gingivae indicated that there was less susceptibility of intercellular material to dissolution under associative conditions than previously reported for human gingivae. This resistance to salt extraction implies a greater degree of macromolecular organization. In consequence, the different macromolecular structure of the pig gingival intercellular matrix may be less susceptible to degradative processes, a suggestion which is supported by the low incidence of periodontal inflammation observed in these pigs.     

Isolation of noncollagenous proteins from gingival connective tissue

Noncollagenous proteins form an integral part of gingiva and other connective tissues. We have performed studies aimed at purification and partial characterization of the gingival noncollagenous proteins. Healthy gingival tissues from mongrel dogs were extracted in neutral buffers, acetic acid, and 6 mol/L urea. Immunoblots using anti-keratin antibodies and CNBr peptide patterns revealed that the majority of the proteins present in these extracts were keratins. To exclude keratins, gingival connective tissue was separated from the epithelium and then extracted. Acid extracts of the connective tissue contained very little protein, whereas urea extracts contained collagen and other noncollagenous proteins. The noncollagenous proteins present in the urea extract were partially purified by DEAE-cellulose chromatography and separated by affinity chromatography through a Sepharose 4B-type I collagen column. At least eight proteins, which ranged in molecular size from 15 to 75 kilodaltons, were obtained by this procedure. We conclude that keratins are major components of whole gingiva extracts and that epithelium must first be removed in order for connective tissue proteins to be obtained. The gingival connective tissue appears to contain several collagen-binding proteins, and these proteins may play an important role in the structure and function of the gingival matrix.     

Mucopolysaccharide localization in gingival epithelium Factors affecting biosynthesis of sulphated proteoglycans in organ cultures of gingival epithelium

The effect of extraneous hyaluronidase, trypsin, hyaluronic acid, chrondroitin sulphate, and commercial heparin on the synthesis and secretion of proteoglycans (mucopolysaccharides) by gingival epithelium in short term incubations was investigated by autoradiography. Small pieces of human gingivae were incubated at 37°C in tissue culture medium (T.C. 199) for 75 min. The first 15 min incubation included a “pulse” of (³⁵S)-sulphate, after which the radioactive incorporation was “chased” in radioactive free medium. Cryostat sections of these pieces were cut, air dried, slide fixed with cetylpyridinium chloride, and prepared for autoradiography. The effect of the various additives in the “pulse” or the “chase” incubations on the autoradiographic localization of incorporated (³⁵S)-sulphate in the epithelium was noted. The responses by the epithelium to the enzymes hyaluronidase and trypsin were different. The former caused marked tissue disruption, probably due in part to degradation of the ground substance. Synthesis and secretion of sulphated macromolecules were evident when the lower concentrations of hyaluronidase were used. Tissue disruption appeared to be less severe. Trypsin in the medium of the gingival incubations appeared to cause both metabolic and secretory disruption. Both the sulphated polyanions, chrondroitin sulphate and heparin, when added to gingival incubations, showed inhibition of localization of (³⁵S)-sulphate label inlercellularly. Chrondroitin sulphate included in the “chase” incubations alone resulted in the inhibition, while only low concentrations of heparin caused any inhibition. These latter data were curious. The interpretations of a comparison of the data from “pulse” and “chase” additions of the non-sulphated hyaluronic acid imply that there was an initial inhibitory effect on secretion which in turn resulted in a subsequent regulation of synthesis of the intercellular sulphated macromolecules. These data and those derived from other tissues such as endothelium, cartilage, and chondrocyte cultures are briefly contrasted.     

The effect of chronic inflammation on gingival connective tissue proteoglycans and hyaluronic acid

Proteoglycans have been isolated and analysed from extracts of normal and chronically inflamed human gingiva in order to determine the effects of chronic inflammation on these important soft connective tissue extracellular macromolecules. The uronic acid content of glycosaminoglycans isolated by papain digestion of normal and inflamed gingiva did not differ significantly. Likewise, electrophoretic analysis revealed that the content of hyaluronic acid, heparan sulfate, dermatan sulfate and chondroitin sulfute was similar. The sulfated glycosaminoglycans from both sources eluted from a Sepharose C1-6B column with a Kav of 0.45 (approximate M_r 25,000). However, hyaluronic acid from normal gingiva was predominantly of a large size eluting in the void volume of a Sepharose. CL-6B column, while that isolated from inflamed tissue was mostly a small molecular weight species which elutccl in the included volume of a Sepharose CL-6B column. Using dissociative conditions, intact proteoglycans could be more readily extracted from inflamed tissues (90% of the total tissue uronic acid) than from normal tissues where only 80% of the total tissue uronic acid was extractable. Even though DEAE-Sephacel ion-exchange chromatography revealed no differences in charge between normal and inflamed gingival proteoglycans, Sepharose CL-4B chromatography revealed more molecular size polydispersity in samples from inflamed tissue than from normal tissue. Taken together, these results indicate that while hyaluronic acid is depolymerized in inflamed tissue, no evidence of sulfated glycosaminoglycan degradation was found. Therefore, the most likely cause for disruption to the molecular integrity of the proteoglycans is via proteolytic alteration to the proteoglycan core protein.     

Development and characterization of an in vitro gingival epithelial model

A 3-dimensional gingival epithelial model has been developed and characterized. Oral epithelial cells and connective tissue fibroblasts were isolated from human gingival tissue and used to create an in vitro oral mucosa co-culture model. Fibroblasts were seeded on a scaffold of nylon mesh, allowed to proliferate and secrete collagen and extracellular matrix proteins to form a stroma capable of supporting the growth of epithelial cells. Epithelial cells were seeded on top of a confluent stromal layer, proliferated and differentiated to form a stratified squamous epithelium. Resident epithelial cells were stimulated, by manipulation of growth medium and culture conditions, to form a multi-layered oral mucosa-like tissue. Histologic analyses revealed cellular architecture exhibiting stromal-epithelial interaction which supports the growth and differentiation of an epithelial layer. lmmunohistochemical analyses confirmed production of types I and III collagen. Immunofluorescence of the stromal layer identified type IV collagen and fibronectin. Fibronectin was also detected on surface epithelium. Differentiation of basal, spinous and granular cells was observed, and the presence of differentiation markers, acidic (K10, 14–16, 19) and basic (Kl–8) cytokeratins were confirmed using broad spectrum cytokeratin antibodies, AE1 and AE3. Development of a discontinuous basal lamina zone, with hemidesmosomes, was observed by electron microscopy. The co-culture was metabolically active, as measured by the thiazoyl blue (MTT) assay for mitchondrial function and [³H] thymidine incorporation into DNA. The human gingival epithelial co-culture model was viable up to 35 days post-epithelial seed. This model may offer opportunities for limited study of periodontal tissue responsiveness.     

Distribution of chondroitin sulfate and dermatan sulfate in normal and inflamed human gingivae.

The effect of inflammation on the distribution of chondroitin sulfate and dermatan sulfate proteoglycans was assessed after normal and inflamed human gingivae were stained with monoclonal antibodies against these extracellular matrix macromolecules. The tissues were obtained following periodontal surgery and reacted with specific antibodies after pre-treatment with chondroitinase ACII or chondroitinase ABC, and staining was visualized by the immunoperoxidase technique. The results indicated that these two proteoglycans were present in both the 4-sulfated and 6-sulfated isomeric forms. While chondroitin sulfate appeared to be uniformly distributed throughout the connective tissue, dermatan sulfate showed greater intensity of staining in the areas immediately subjacent to the epithelium. Positive staining for chondroitin sulfate was noted in the intercellular spaces of the epithelium. In inflamed tissues, there was significant staining associated with 4-sulfated dermatan sulfate and chondroitin sulfate, but this had lost the structured pattern of staining noted in normal sections. The 6-sulfated isomeric forms were greatly reduced in inflamed tissues and tended to show a predilection to be localized within the perivascular tissues. In the inflamed tissues, there was intense staining for chondroitin sulfate associated with the infiltrating inflammatory cells. These findings corroborate earlier biochemical studies on normal and inflamed gingival tissues. The specific tissue localization of dermatan sulfate and chondroitin sulfate in tissues damaged by inflammation indicates that, as opposed to the large loss of collagenous material noted during inflammation, there is not a corresponding large loss of proteoglycan. Indeed, at specific inflammatory foci, the intensity of staining for these macromolecules may intensify.     

Langerhans cells in oral epithelium of chronically inflamed human gingivae

This study describes the histopathological features and the distribution of oral epithelial Langerhans cells in 19 gingival biopsies originating from an adult Tanzanian population characterized by very poor oral hygiene and severe gingival inflammation. Light-microscopically, all biopsies contained often large inflammatory connective tissue infiltrates, 6 of which predominantly contained plasma cells while the rest were dominated by lymphocytes. Seven specimens contained peculiar accumulations of round lymphoid and dendritic cells in the lower cell layers of the oral epithelium. These phenomena have not previously been demonstrated in human gingiva and deserve further attention in studies on the pathogenesis of periodontal diseases. Immuno-histochemical staining with OKT6, OKT4 and OKT8 antibodies showed markedly increased numbers of OKT6-positive cells in 7 specimens and clusters of OKT4- and OKT8-positive cells in the oral epithelium of 4 specimens. High numbers of OKT6-positive cells were not related to the presence of intra-epithelial, non-keratinocyte infiltrates or large connective tissue infiltrates. The variable numbers of oral epithelial Langerhans cells may therefore result from different bacterial antigens elucidating different responses or, alternatively, reflect different responses to similar plaque antigens penetrating the surface of the oral epithelium.     

Collagenases and tissue inhibitors of metalloproteinases: a functional balance in tissue degradation

BACKGROUND: Members of the family of matrix metalloproteinases (MMPs; also called collagenases or matrixins) are key enzymes in matrix degradation. They function at neutral pH and can digest synergistically all the matrix macromolecules. Biochemical and clonal studies indicate that there are three major groups: the specific collagenases cleave interstitial collagens; the gelatinases degrade types IV, V, VII and XI collagens and act synergistically with collagenases by degrading denatured collagens (gelatins): and the stromelysins have broader specificity and can degrade basement membrane collagens as well as proteoglycans and matrix gly-coproteins. Others not in these groups are matrilysin, metalloelastase and a recently cloned membrane-bound metalloproteinase. MMPs are Zn²⁺- and Ca²⁺-requiring endopeptidases and are secreted in a latent proform: activation involves the loss of a propeptide. Naturally occurring inhibitors, TlMPs (Tissue Inhibitors of MetalloProteinases), are important controlling factors in the actions of MMPs, and tissue destruction in disease processes often correlates with an imbalance of MMPs over TIMPs. The major inhibitor is TIMP-I (or TIMP), a 30-kDa glycoprotein that is synthesised by most cells. A second unglycosylated inhibitor, TIMP-2, which is less abundant, has the interesting property of binding to the proform of gelatinase A and is involved in controlling its activation. BIOLOGICAL AND PSYCHOLOGICAL IMPLICATIONS: The expression of MMPs and TlMPs by cells is regulated by many cytokines (particularly interleukin-I, IL-I), growth factors and hormones, some of which are specific to cell type and others that are ubiquitous (eg transforming growth factor β, TGF-β). Many of these factors are products of monocytes/macrophages and their production in inflammatory situations is therefore part of the chain of events leading to tissue degradation. From many recent studies it seems that tissue destruction, both physiological and pathological, is correlated with an imbalance of inhibitors over proteinases. We proposed that one way in which pathogenic organisms might mediate tissue degradation in periodontal diseases is through the ability of cell wall antigens to stimulate cytokine production by circulating mononuclear cells. These would then induce MMP synthesis by resident gingival cells (or by the mononuclear cells themselves), thereby initiating degradative events. We have identified MMPs in human gingival biopsy specimens by using specific poly-clonal antibodies and indirect immunofluorescence. Their distributions are extremely variable, both in the connective tissue and the epithelium, but the results indicate that host cell production of MMPs may contribute to tissue degradation in periodontal disease. TIMP could also be found in some situations and could be a limiting factor.     

Cytolethal distending toxin damages the oral epithelium of gingival explants

The cytolethal distending toxin (Cdt), expressed by the periodontal pathogen Aggregatibacter actinomycetemcomitans, inhibits the proliferation of cultured epithelial cells by arresting the cell cycle. The gingival epithelium is an early line of defense against microbial assault. When damaged, bacteria collectively gain entry into underlying connective tissue where microbial products can affect infiltrating inflammatory cells, leading to the destruction of the attachment apparatus. Histological evaluation of rat and healthy human gingival tissue exposed ex vivo to the Cdt for 36 and 18 hours, respectively, revealed extensive detachment of the keratinized outer layer and distention of spinous and basal cells in the oral epithelium. Treated human tissue also exhibited disruption of rete pegs and dissolution of cell junctions. Cells in the connective tissue appeared unaffected. Primary gingival epithelial cells, but not gingival fibroblasts, isolated from the same healthy human tissue were cell-cycle-arrested when treated with the toxin. These findings provide new evidence that the Cdt severely damages the oral epithelium, ex vivo, by specifically targeting epithelial cells, in situ. The Cdt shows preferential targeting of the epithelium as opposed to connective tissue in animal and human gingival explant models. Abbreviations: cytolethal distending toxin (Cdt), connective tissue (CT), 4',6-diamidino-2-phenylindole (DAPI), human gingival epithelial cells (HGEC), human gingival explants (HGX), human gingival fibroblasts (HGF), junctional epithelium (JE), oral epithelium (OE), rete pegs (RP), sulcular epithelium (SE).     

Localization of interleukin-1 (IL-1) mRNA-expressing macrophages in human inflamed gingiva and lL-1 activity in gingival crevicular fluid

The exact cell type and site(s) involved in interleukin-1 (lL-1) production during gingival inflammation was determined by combining immunohistochemistry and in situ hybridization. IL-1 messenger RNA (mRNA)-expressing cells in human inflamed gingiva were identified as macrophages. The rate of IL-α mRNA expression in these macrophages was the same as IL-1 β mRNA expression. The rate of IL-1 mRNA expression was higher in connective tissue furthest from the pocket epithelium, although more macrophages were present at the connective tissue subjacent to the pocket epithelium. The IL-1 activity in gingival crevicular fluid (GCF) obtained from inflamed gingiva was higher than that from healthy gingiva and decreased after periodontal therapy. The IL-1 activity in GCF was almost completely abolished by the addition of anti-IL-1α antibody but not by anti-IL-1 β antibody, indicating that IL-1α is the predominant form in GCF. However, the IL-1 activity in GCF was unrelated to the number of IL-1 mRNA-exprerssing macrophages in the same gingival site where the GCF was obtained at the same time. The results suggest that macrophages in the connective tissue subjacent to the oral epithelium contribute to the production of IL-1 but those in connective tissue subjacent to the pocket epithelium play a different role in the generation of gingival inflammation.     

In situ hybridization study on tissue inhibitors of metalloproteinases (TIMPs) mRNA-expressing cells in human inflamed gingival tissue

This study presents the exact cell types and localization of tissue inhibitors of metalloproteinases (TIMPs) production sites in periodontal diseased gingiva by means of in situ hybridization. Gingival tissue specimens were fixed, embedded and hybridized in situ with specific digoxigenin-labeled cRNA probes (386 and 496 bp). TIMP-1 and -2 mRNAs were expressed on macrophages, mononuclear cells, capillary endothelial cells and some fibroblasts throughout the gingival tissue. In periodontitis, TIMP-1 and -2 mRNA-expressing cells showed significantly different localization. TIMP-1 mRNA was broadly observed in the gingival connective tissue while TIMP-2 mRNA was predominantly expressed in the connective tissue adjacent to the pocket epithelium (p < 0.01). Fewer TIMPs mRNA were observed in minimal gingivitis than in periodontitis, especially in the middle zone of gingival tissue. Thus, TIMP-1 and TIMP-2 mRNA was detected differentially and site-specifically in periodontal diseased gingival tissue.     

Expression of integrins in human gingiva

The distribution of the alpha 1-alpha 6 subunits of beta 1 integrins was studied by using a panel of monoclonal antibodies in indirect immunofluorescence microscopy. The results showed that the beta 1 subunit was expressed at the cell membrane of basal cells of gingival epithelium, throughout the cells of junctional epithelium (JE), and in cells of connective tissue, including endothelial cells and, more faintly, in inflammatory cells in gingival connective tissue. The alpha 4 subunit was expressed selectively in inflammatory cells, and the alpha 5 subunit was expressed in cells throughout gingival connective tissue. An overall cell membrane immunoreactivity for the alpha 2 and alpha 3 subunits was shown in basal cells of gingival epithelium and in cells of JE, corresponding to the epithelial localization of the beta 1 subunit. The alpha 6 subunit was polarized to the basal aspects of basal epithelial cells, but was also present in an overall cell surface distribution in basal cells and in cells of JE. The beta 4 integrin subunit was mainly expressed at the basal aspects of basal cells in gingival epithelium and JE. The results indicate that the alpha 2/beta 1, alpha 3/beta 1, alpha 6/beta 1, and alpha 6/beta 4 integrins are all expressed in human gingival epithelium. Of these, the alpha 6/beta 4 integrin complex is the major candidate for mediation of the attachment of epithelial cells to the basement membrane facing the connective tissue and probably also the tooth.     

The oxytalan connective tissue fibres in gingival hyperplasia in patients treated with sodium diphenyl-hydantoin

Oxytalan fibres in hyperplastic gingival papillae from 12 young epileptics who had been treated with sodium diphenyl-hydantoin were studied with modifications of Fullmer and Lillie's (1958) and Löe and Nuki's (1964) staining methods. These fibres were compared with the fibres in clinically normal gin-givac and in tissue from fibrous epulides.
Fibres reacting with peracetic acid-aldehyde fuchsin (i.e. oxytalan fibres) were present throughout the connective tissue and were especially numerous near the surface epithelium and in areas of inflammatory infiltration. The oxytalan fibres were especially prominent along the junction with epithelium, between the rete pegs and in the deeper connective tissue near bone where they tended to be arranged in large parallel bundles. In cases of fibrous epulis, however, there were very few oxytalan fibres in the connective tissue adjacent to the surface epithelium.
It is concluded that the connective tissue performs an important supportive function to the epithelium in gingival hyperplasia, and is of special importance in the genesis of gingival hyperplasia in patients under treatment with sodium diphenyl-hydantoin.     

The role of gingival connective tissue in determining epithelial differentiation

Free grafts of connective tissue, without epithelium, were transplanted from either the keratinized gingiva or the non-keratinized alveolar mucosa (controls) into areas of the alveolar mucosa in seven monkeys. The grafts were placed in pouches created in the connective tissue as close as possible to the overlying epithelium. After 3–4 weeks, the transplants were exposed by removal of the overlying tissue in order to allow epithelialization from the surrounding non-keratinized alveolar mucosa. The transplants were examined clinically and histologically at time periods between 1 and 12 months.
The gingival connective tissue grafts became covered with keratinized epithelium displaying the same characteristics as those of normal gingival epithelium. The alveolar mucosa transplants were covered with non-keratinized epithelium. This indicates that gingival connective tissue is capable of inducing the formation of a keratinized gingival epithelium.     

Detection and possible biological role of chondroitinase and heparitinase enzymes produced by Porphyromonas gingivalis W50

Gingival crevicular fluid levels of the glycosaminoglycan (GAG) chondroitin-4-sulphate (C-4-S) have received increased attention as potential indicators of periodontal tissue turnover. However, little is known about the relationship between crevicular fluid connective tissue metabolites and microbial factors. In this study Porphyromonas gingivalis , a periodontopathogen, was investigated for its ability to degrade the GAGs C-4-S, dermatan sulphate (DS) and heparan sulphate (HS) in vitro . The effect of P. gingivalis extracts on the proteoglycans (PG) derived from human gingiva were also investigated. The presence of chondroitinase and heparitinase eliminase enzymes were identified from the vesicle fraction of P. gingivalis W50. These enzymes were extracted from the vesicle fraction by a differential centrifugation technique and partially purified by non-denaturing gel filtration chromatography which revealed heparitinase enzyme peaks at 200 and 150 kDa and chondroitinase at 70 kDa. Gingival proteoglycans for use as substrates were purified using 4 M guanidinium chloride extraction and anion exchange chromatography; these proteoglycans contained 48% DS, 27% C-4-S and 13% HS P. gingivalis chondroitinase and heparitinase enzymes were capable of the degradation of C-4-S and HS but not DS GAGs. The presence of chondroitinase enzymes produced by P. gingivalis may influence levels of connective tissue metabolites in crevicular fluid. Furthermore these enzymes, particularly the heparitinase, may be involved in the initial permeation of the gingival epithelium, permitting the ingress of further microbial virulence factors.     

Effect of oxygen tension and indomethacin on production of collagenase and neutral proteinase enzymes and their latent forms by porcine gingival explants in culture.

Porcine gingival explants cultured in a serum-free minimally essential medium produced at least two distinct neutral proteinases which, in combination, digested tissue collagen. One proteolytic activity was typical of collagenases with a specific, limited activity on native gingival collagens. The second degraded denatured collagen. Both enzymes also existed in latent forms which were activated during culture. The enzymes were inhibited by EDTA and O-phenanthroline, and to some extent by dithiothreitol and cysteine. By increasing the O₂ tension of the culture medium from pO₂ of 150mm Hg to pO₂ of 280mm Hg, the production of both enzymes and their precursors was increased two-fold. Conversely. 5 μg/ml indornethacin in the medium significantly depressed the synthesis of these enzymes. When gingival epithelial tissue and connective tissue were cultured separately, neutral proteinases were only produced by the connective tissue. The production of the collagenolytic enzymes was accompanied by a marked general loss of tissue cellularity and cell necrosis. Radioautography with ³H-proline indicated that protein synthesis was most active at the epithelium-connective tissue junction. The collagenase and neutral proteinase appear to have a similar catalytic mechanism and may be secreted as a collagenolytic enzyme package by the connective tissue cells. The inhibition of the production of these enzymes by indomethacin indicates that prostaglandins may have an important role in the degradation of gingival connective tissue.     

硫酸软骨素蛋白多糖与牙周炎的相关性

本实验旨在研究硫酸软骨素蛋白多糖与牙周炎的相关性。采用免疫组织化学方法,对牙周炎引起的硫酸软骨素蛋白多糖变化进行研究。结果显示硫酸软骨素(DS、C4S、C6S)广泛分布于上皮下结缔组织、牙周韧带和血管周围,在牙槽骨局限于哈佛氏管和骨小腔内壁。牙周炎时随着组织溶解破坏,其染色反应减弱消失,说明硫酸软骨素是牙周组织的基本成分,与牙周炎关系密切。     

Healing following implantation of periodontitis-affected roots into gingival connective tissue

Abstract The aim of the present investigation was to examine if a new connective tissue attachment can be established on a previously periodontitis involved root surface, located in contact with gingival connective tissue during healing. A total of 28 teeth in one dog (beagle) and two monkeys (Macaca cynomolgus) were subjected to experimental periodontal tissue breakdown by placing cotton floss ligatures or orthodontic elastics around the teeth. The ligatures were left in situ until about 50% of the supporting tissues had been lost. Following resection of the crowns, the teeth were root filled and the exposed parts of the roots thoroughly scaled and planed. Each root was extracted and implanted into grooves prepared in edentulous areas of the jaws in such a way that the root was embedded to half its circumference in bone, leaving the remaining part to be covered by the gingival connective tissue of the repositioned flap of the recipient site. Root implantation and sacrifice of the animals were scheduled to allow for observation periods of 2 and 3 months of healing. An analysis of histologic specimens, obtained from biopsies of the recipient site tissues, disclosed that a new fibrous attachment failed to form on a previously “exposed” root surface located in contact with gingival connective tissue. In areas of the roots where the periodontal ligament tissue was preserved prior to transplantation, a fibrous reattachment occurred between the root and the adjacent gingival tissue. The results indicate that gingival connective tissue does not possess the ability to establish conditions which enable the formation of a new connective tissue attachment.     

Immunohistochemical localization of CD1a and S100 in gingival tissues of healthy and chronic periodontitis subjects

Oral Diseases (2012) 18, 778-785 Objective: The aim of this study was to evaluate the presence and distribution of CD1a and S100 protein markers in states of gingival health and chronic periodontitis in human subjects. Materials and Methods: Gingival tissue samples were derived from 10 healthy and 10 chronic periodontitis-affected human subjects. The presence and distribution of CD1a and S100 protein was assessed using immunohistochemistry, and the cell types involved in their expression was determined. Results: The presence and distribution of CD1a was confined only to the gingival epithelium, whereas S100 was seen in the epithelium and connective tissue. However, increased expression of both CD1a and S100 protein was seen in periodontitis-affected gingival tissues compared with healthy gingiva. Immunohistochemistry demonstrated that CD1a- and S100-positive cells in the epithelium are Langerhans cells (LCs) and S100 positive cells in the connective tissue are dendritic cells (DCs). Conclusion: Our findings suggest the transition of CD1a-positive LCs to S100-positive DCs from epithelium to connective tissue in response to an antigenic challenge. Demonstration of increased number of S100-positive DCs in the gingival connective tissue in chronic periodontitis possibly suggests their involvement in bone resorption in addition to their antigen presentation property.     

Density of CD1a-labeled Langerhans' cells in normal human gingiva and in nifedipine- and immunosuppressive medication-induced gingival overgrowth.

BACKGROUND: The purpose of this study was to compare the distribution of Langerhans' cells in normal human gingiva and in nifedipine- and immunosuppressive medication-induced gingival overgrowth by means of an immunohistochemical study. METHODS: Gingival samples were collected from 11 nifedipine-medicated cardiac patients, 22 triple-medicated (azathioprine, prednisolone, and cyclosporin A) renal transplant recipients, and 28 generally healthy individuals. Patients were grouped into the immunosuppression group, the combined immunosuppression and nifedipine group, the nifedipine group, and the generally healthy control group. Five microm-thick cryostat sections were stained with monoclonal antibody (mAb) for CD1a using an avidin-biotin-enzyme complex (ABC) method. Numbers of CD1a-labeled cells/mm2 were determined in 6 areas: oral epithelium, oral sulcular epithelium, sulcular epithelium, middle connective tissue, connective tissue beneath the oral epithelium, and connective tissue beneath the sulcular epithelium. Significances of differences between the groups were tested by means of the Kruskall-Wallis test, and significances of differences between pairs of results by the Mann-Whitney U-test and the t test. RESULTS: Numbers of CD1a-labeled cells were significantly lower in the medicated groups than in controls in all 3 epithelial areas (P <0.0001) and in the connective tissue beneath the sulcular epithelium (P <0.0021). There were significantly fewer CD1a-labeled cells in the sulcular epithelium in the nifedipine group than in the other medication groups. CONCLUSIONS: The reduced numbers of CD1a-labeled cells found in nifedipine-induced gingival overgrowth were similar to the reduced numbers of CD1a-labeled cells in gingival overgrowth associated with immunosuppressive medication.