Adhesion Of Gingival Epithelial Cells Research Articles

Anodic oxidation- and hydrogenation-produced TiO2 nanotubes on titanium and its effect on gingival epithelial cell adhesion ability

The gingival epithelium plays a crucial role in achieving long-term stability of dental implants, and the hydrogenated TiO2 nanotubes with a superhydrophilic surface exhibit more excellent biological activity than pure titanium implants. However, the effects of the hydrogenated TiO2 nanotubes on human gingival epithelial cells remain unclear. Here, we fabricated hydrogenated TiO2 nanotubes using anodization and hydrogenation to investigate the adhesion of human gingival epithelial cells (HGEs) on structured surfaces in vitro. The topography, roughness, and wettability of three sample types—titanium (Ti), TiO2 nanotubes (TNTs), and hydrogenated TiO2 nanotubes (H2-TNTs)—were characterized. To evaluate cell adhesion, the HGEs were co-cultured with these specimens. This allowed for the examination of both the adhesion morphology and the number of cells adhering to each material’s surface. Expression levels of genes and proteins related to cell adhesion were also assessed. H2-TNTs demonstrated nanoscale topography similar to TNTs in terms of diameter and height and maintained a superhydrophilic surface (with a static water contact angle of < 5°). The number of HGEs adhering to H2-TNTs was notably higher. Furthermore, HGEs on H2-TNTs displayed a more stretched morphology in comparison to the other two groups. Notably, the expression levels of adhesion-related genes and proteins in H2-TNTs surpassed those of the other two groups. Hence superhydrophilic H2-TNTs significantly enhance the adhesion ability of HGEs on the material surface.

Surface modification affects human gingival epithelial cell behavior on polyetheretherketone surfaces.

Gingival epithelial attachment to the abutment is important for the prevention of peri-implantitis. Polyetheretherketone (PEEK) has recently gained attention as an alternative material to titanium; however, it is biologically inert, which is disadvantageous for obtaining soft tissue sealing of the transmucosal part of the implant abutment. Therefore, ultraviolet (UV) irradiation, argon plasma irradiation, and buffing were selected as treatments to modify the PEEK surface. None of the treatments had any effect on the material's mechanical strength. The UV and plasma treatments did not significantly affect the surface morphology. Surface elemental analysis showed a decrease in carbon content and an increase in oxygen content and wettability for all treatments. Human gingival epithelial cell adhesion, proliferation, and the expression of adhesion proteins integrin β4 and laminin 332, were increased. Surface modification to PEEK was suggested to enhance cell activity on PEEK.

Effect of Citrus aurantium L. Essential Oil on Streptococcus mutans Growth, Biofilm Formation and Virulent Genes Expression.

In an oral cavity, dental caries, periodontal disease, and endodontic lesions are caused by well-known bacterial and fungal pathogens. Essential oils (EOs) have demonstrated antimicrobial activity suggesting their use for oral hygiene. The goal of this study was to evaluate the interaction of bitter orange flower (Citrus aurantium L.) essential oil with cariogenic bacteria Streptococcus mutans and human gingival epithelial cells. After extraction, the chemical composition of the essential oil was analyzed by gas chromatography, and its antimicrobial activity was evaluated against the growth and the expression of virulent genes in S. mutans. Finally, the effects of this essential oil on human gingival epithelial cell adhesion and growth were assessed using cell adhesion and proliferation assays. We showed that the major constituents of the tested essential oil were limonene, linalool, and β-ocimene. The essential oil reduced the growth of S. mutans, and decreased expression of comC, comD, comE, gtfB, gtfC, and gbpB genes. It should, however, be noted that essential oil at high concentration was toxic to gingival epithelial cells. Overall, this study suggests that C. aurantium L. essential oil could be used to prevent/control oral infections.

Antibody drug for control of gingival epithelial cell adhesion

Antibody drug for control of gingival epithelial cell adhesion

Interactions of AMTN, ODAM and SCPPPQ1 proteins of a specialized basal lamina that attaches epithelial cells to tooth mineral

A specialized basal lamina (sBL) mediates adhesion of certain epithelial cells to the tooth. It is distinct because it does not contain collagens type IV and VII, is enriched in laminin-332, and includes three novel constituents called amelotin (AMTN), odontogenic ameloblast-associated (ODAM), and secretory calcium-binding phosphoprotein proline-glutamine rich 1 (SCPPPQ1). The objective of this study was to clarify the structural organization of the sBL. Fluorescence and immunogold labeling showed that the three proteins co-localize. Quantitative analysis of the relative position of gold particles on the sBL demonstrates that the distribution of ODAM is skewed towards the cell while that of AMTN and SCPPPQ1 tends towards the tooth surface. Bacterial two-hybrid analysis and co-immunoprecipitation, gel filtration of purified proteins and transmission electron and atomic force microscopies highlight the propensity of AMTN, ODAM, and SCPPPQ1 to interact with and among themselves and form supramolecular aggregates. These data suggest that AMTN, ODAM and SCPPPQ1 participate in structuring an extracellular matrix with the distinctive capacity of attaching epithelial cells to mineralized surfaces. This unique feature is particularly relevant for the adhesion of gingival epithelial cells to the tooth surface, which forms a protective seal that is the first line of defense against bacterial invasion.

Smad2 overexpression enhances adhesion of gingival epithelial cells

ObjectiveGingival epithelial cells play an important role in preventing the initiation of periodontitis, by their hemidesmosomal adhesion to the tooth root surface. Adhesion requires integrin-extracellular matrix (ECM) interactions that are intricately regulated by transforming growth factor-β (TGF-β) signaling. However, the mechanisms underlying the interplay between adhesion molecules and TGF-β, especially the respective roles of Smad2 and Smad3, remain elusive. In this study, we examined the effects of Smad overexpression on gingival epithelial cell adhesion and expression profiles of integrin and ECM-related genes. MethodsHuman gingival epithelial cells immortalized by the SV40 T-antigen were transfected with Smad2- and Smad3-overexpression vectors. A cell adhesion assay involving fluorescence detection of attached cells was performed using the ArrayScan imaging system. Real-time PCR was performed to examine the kinetics of integrin and ECM gene expression. In vitro and in vivo localization of adhesion molecules was examined by immunofluorescence analysis. ResultsBy using SB431542, a specific inhibitor of the TGF-β type I receptor, Smad2/3 signaling was confirmed to be dominant in TGF-β1-induced cell adhesion. The Smad2-transfectant demonstrated higher potency for cell adhesion and integrin expression (α2, α5, β4, and β6) than the Smad3-transfectant, whereas little or no change in ECM expression was observed in either transfectant. Moreover, the gingival epithelium of transgenic mice that overexpressed Smad2 driven by the keratin 14 promoter showed increased integrin α2 expression. ConclusionThese findings indicate the crucial role of Smad2 in increased adhesion of gingival epithelial cells via upregulation of integrin α2.

Anodized-hydrothermally treated titanium with a nanotopographic surface structure regulates integrin-α6β4 and laminin-5 gene expression in adherent murine gingival epithelial cells

PurposePeri-implant epithelium associated with the structure of the internal basal lamina is in contact with a transmucosal portion of the endosseous implant surface. This contact is important to protect the many complex factors required for the long-term stability and maintenance of the implant. This study investigated the effect of initial adhesion of gingival epithelial cells to anodized-hydrothermally treated commercially pure titanium with nanotopographic structure (SA-treated c.p.Ti). Changes in cell morphology and gene expression of integrin-α6β4 and laminin-5 were assessed. MethodsMurine immortalized gingival epithelial (GE1) cells were cultured for 1–3 days on c.p.Ti, anodic oxide (AO) c.p.Ti, and SA-treated c.p.Ti disks. Cell morphology was analyzed using scanning electron microscopy (SEM). Cell proliferation was analyzed using the WST-1 assay. Integrin-α6β4 and laminin-5 (α3, β3, γ2) mRNA levels were measured using real-time quantitative RT-PCR. ResultsThe GE1 cells appeared flattened with extensions on all disks by SEM analysis. Filopodium-like extensions were bound closely to the nanotopographic structure surface of SA-treated c.p.Ti especially at day 3 of culture. GE1 cell proliferation as well as the expression of integrin-α6β4 and laminin-5 (α3, β3, γ2) mRNAs was significantly higher on SA-treated c.p.Ti than on c.p.Ti and AO c.p.Ti disks after 3 days (P<0.05). ConclusionsGingival epithelial cells initially attach to a transmucosal portion of SA-treated c.p.Ti implant material and subsequently express the integrin-α6β4 adhesion molecule and the laminin-5 extracellular matrix molecule. This cell behavior may play a key role in maintaining the peri-implant oral mucosal tissue barrier.

Fabrication and Cell Culturing on Carbon Nanofibers/Nanoparticles Reinforced Membranes for Bone-Tissue Regeneration

Poly-L-lactic acid (PLLA), PLLA/hydroxyapatite (HA), PLLA/multiwalled carbon nanotubes (MWNTs)/HA, PLLA/trifluoroethanol (TFE), PLLA/gelatin, and carbon nanofibers (CNFs)/β-tricalcium phosphate (β-TCP) composite membranes (scaffolds) were fabricated by electrospinning and their morphologies, and mechanical properties were characterized for use in bone tissue regeneration/guided tissue regeneration. MWNTs and HA nanoparticles were well distributed in the membranes and the degradation characteristics were improved. PLLA/MWNTs/HA membranes enhanced the adhesion and proliferation of periodontal ligament cells (PDLCs) by 30% and inhibited the adhesion of gingival epithelial cells by 30%. Osteoblast-like MG-63 cells on the randomly fiber oriented PLLA/TEF membrane showed irregular forms, while the cells exhibited shuttle-like shapes on the parallel fiber oriented membrane. Classical supersaturated simulated body fluids were modified by CO2 bubbling and applied to promote the biomineralization of the PLLA/gelatin membrane; this resulted in predictions of bone bonding bioactivity of the substrates. The β-TCP membranes exhibit good biocompatibility, have an effect on PDLC growth comparable to that of pure CNF membrane, and can be applied as scaffolds for bone tissue regeneration.

Effect of Titanium Surface Calcium and Magnesium on Adhesive Activity of Epithelial-Like Cells and Fibroblasts

In the present study, we investigated the hydrothermal treatment of titanium with divalent cation solutions and its effect in promoting the adhesion of gingival epithelial cells and fibroblasts in vitro. Gingival keratinocyte-like Sa3 cells or fibroblastic NIH3T3 cells were cultured for 1 h on experimental titanium plates hydrothermally-treated with CaCl(2) (Ca) or MgCl(2) (Mg) solution, or distilled water (DW). The number and adhesive strengths of attached cells on the substrata were then analyzed. The number of Sa3 cells adhering to the Ca- and Mg-treated plates was significantly larger than in the DW group, but the strength of this adhesion did not differ significantly between groups. In contrast, NIH3T3 cell adhesion number and strength were increased in both the Ca and Mg groups compared to the DW group. Fluorescent microscopic observation indicated that, in all groups, Sa3 had identical expression levels of integrin β4 and development of actin filaments, whereas NIH3T3 cells in the Ca and Mg groups displayed much stronger punctate cytoplasmic signals for vinculin and more bundle-shaped actin filaments than cells in the DW group. As a result, it was indicated that the hydrothermal treatment of titanium with Ca or Mg solution improved the integration of soft tissue cells with the substrata, which may facilitate the development of a soft tissue barrier around the implant.

Lutheran Blood Group Antigen as a Receptor for α5 Laminins in Gingival Epithelia

Lutheran blood group glycoprotein (Lu) is a transmembrane receptor of the immunoglobulin superfamily. Lu serves as a receptor for alpha5 laminins (Lm). The Lm alpha5 chain is a constituent of Lms-511 and -521. Lm-511 is found in most human basement membranes (BMs) and also is detected in BM of gingival epithelia. Recent studies indicated that Lu mediates cell adhesion to Lms-511/521 independently or in concert with integrins. This study focused on the expression of Lu in gingival epithelia and on cultured immortalized gingival keratinocytes. The role of Lu and alpha(3) and beta(1) integrin subunits in the adhesion of oral epithelial cells to Lms-511/521 was also studied. Immunofluorescence microscopy was used to study the expression of Lu in gingival tissues and in cultured gingival keratinocytes. Immunoprecipitation of radioactively metabolically labeled cells was used to detect Lu. Cell adhesion to Lm-511/521 preparation and to pure Lm-511 was studied in quantitative cell adhesion experiments. Morphological adhesion assays were carried out for visualization of the morphology and adhesion structure formation of the adhering cells. Immunofluorescence studies on gingiva showed complete coalignment of Lu on basal epithelial cells with the BM Lm alpha5 chain. A surface-confined, punctate immunoreaction for Lu was detected throughout cell surfaces on cultured gingival cells. Immunoprecipitation showed a broad polypeptide with molecular weight 85,000. In quantitative cell adhesion assays, the adhesion of cells to both Lm alpha5 preparations was diminished with monoclonal antibodies (MAbs) against integrin alpha(3) and even more effectively with MAbs against the beta(1) subunit. When the adhesion sites were blocked with soluble recombinant Lu (sol-Lu), the adhesion of gingival epithelial cells to Lms-511/521 was reduced significantly, and sol-Lu increased the inhibition with integrin alpha(3) antibody. Lm-511 did not induce lamellipodia or focal contacts in cultured gingival keratinocytes. Lu was in coalignment with Lm alpha5 chain in gingival epithelia. Lu also seemed to have a role in gingival epithelial cell adhesion together with integrin alpha(3)beta(1).

Function of laminins and laminin-binding integrins in gingival epithelial cell adhesion.

In human gingiva, epithelial cells attach to their adjacent tissues by means of specialized molecular adhesion complexes and a basement membrane. Little is known about the synthesis of adhesion proteins by gingival keratinocytes; we, therefore, studied how cultured immortalized gingival epithelial cells produce laminins and express laminin-binding integrins. We presumed that different laminins and integrins would be involved in the adhesion of gingival epithelial cells. We cultured gingival keratinocytes and studied their production of laminins and expression of integrins using immunofluorescence microscopy, immunoprecipitation, and immunoblotting methods and by quantitative cell adhesion experiments. We also studied how gingival tissue expresses these adhesion proteins in vivo by using immunofluorescence microscopy. In immunofluorescence microscopy, the cells were seen to organize chains of laminin-5 (alpha3beta03gamma2) to extracellular patches, whereas the alpha5 chain of laminin-10 (alpha5betalgamma1) could only be seen intracellularly. Of the laminin-binding integrin subunits, integrin a6 subunit was organized to dotted arrays, typical of prehemidesmosomal adhesions, whereas integrin alpha3 subunit was located at cell-cell junctions, in prehemidesmosomal structures, and at some locations also in small focal-contact like patches. Integrin beta1 subunit was found at cell-cell junctions and in focal contacts. Immunoprecipitation experiments showed that the cells synthesize and secrete chains of laminin-5 and laminin-10. In quantitative cell adhesion experiments, the cells adhered efficiently to these laminins by using cooperatively integrin alpha3beta1 and alpha6beta1 integrin complexes. None of the other known laminin-binding integrin subunits appeared to be significantly involved in cell adhesion to these laminin isoforms. Our results provide new information on gingival epithelial cell adhesion and extracellular matrix production and may thus aid in the understanding of periodontal physiology.