976 resultados para HUMAN ORAL FIBROBLASTS


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Implant topography is an important factor that influences many cell types. To understand the role of topography in the inflammatory events, we evaluated the response of human gingival fibroblasts (HGFs) by the release pattern of cytokines. HGFs were cultured on Ti discs for 24 and 48 h. Four different surface treatments were used: machining method (turned), blasting followed by an acid-etching method (BAE), oxidative nanopatterning (ON) method, and an association of blasting followed by an acid-etching plus oxidative nanopatterning (BAE+ON) method. Extracellular levels of IL-6, IL-8, transforming growth factor beta (TGF-beta), IL-4, and IL-10 were measured by enzyme-linked immunosorbant assay. Increased levels of IL-6 and IL-8 were observed in all surfaces after 24 h which decreased after 48 h. BAE, ON, and BAE+ON surfaces showed a reduction in IL-6 levels compared with the turned after 48 h (p < 0.05). On one hand, IL-8 production was lower in BAE+ON in comparison to the turned surface (p < 0.05). On the other hand, IL-4 showed increased levels with 48 h, which were significantly different between turned, BAE, and ON surfaces, but not with BAE+ON. Additionally, TGF-beta and IL-10 production were not detected. This study indicates that nanotopography might be important in the modulation of the inflammatory response in cultured HGFs. (c) 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A:2629-2636, 2012.

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Background and Objective: Substance P may play a role in the pathogenesis of periodontal disease; however, its mechanisms of modulation are not clear. This study evaluated the effect of two concentrations of Substance P on the expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in cultured human gingival fibroblasts. Materials and Methods: Fibroblasts were stimulated for 48 h with 10(-4) or 10(-9) m Substance P; untreated fibroblasts served as controls. The expression of MMP-1, -2, -3, -7 and -11 and of TIMP-1 and -2 was evaluated using real-time polymerase chain reaction and western blotting. Resulsts: There was a significant, concentration-dependent stimulatory effect of Substance P on MMP-1, -2, -3 and -7 and TIMP-2 gene expression (p < 0.05), and a probable effect on MMP-11 (p = 0.06). At the higher concentration (10(-4) m Substance P), MMP-1, -2, -3, -7 and -11 and TIMP-2 showed the greatest up-regulation; at the lower concentration (10(-9) (M) Substance P), MMP-1, -3 and -7 and TIMP-2 exhibited diminished up-regulation, with MMP-2 and -11 showing down-regulation (p < 0.05). Expression of TIMP-1 was not affected by Substance P (p > 0.05). Western blotting confirmed that Substance P up-regulated MMP-1, -2, -3 and -11 and TIMP-2. MMP-1, -3 and -11 and TIMP-2 showed greater up-regulation at the higher Substance P concentration and diminished up-regulation at the lower concentration. MMP-2 was up-regulated to a similar degree at both Substance P concentrations. Conclusion: In gingival fibroblast cells, Substance P at the higher concentration (10(-4) m) induced greater up-regulation of MMP-1, -3 and -11 and TIMP-2 expression, but at the lower concentration (10(-9) (M)) induced diminished up-regulation, which may represent a mechanism for modulating periodontal breakdown.

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Both tissue plasminogen activator (t-PA) and plasminogen activator inhibitor 2 (PAI-2) are important proteolysis factors present in inflamed human periodontal tissues. The aim of the present study was to investigate the effect of lipopolysaccharide (LPS) on the synthesis: of t-PA and PAI-2 by human gingival fibroblasts (HGF). LPS from different periodontal pathogens including Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Fusobacterium nucleatum were extracted by the hot phenol water method. The levels of t-PA and PAI-2 secreted into the cell culture media were measured by enzyme-linked immunosorbent assays (ELISA). The mRNA for t-PA and PAI-2 were measured by RT-PCR. The results showed t-PA synthesis was increased in response to all types of LPS studied and PAI-2 level was increased by LPS from A. actinomycetemcomitans and F. nucleatum, but not P. gingivalis. When comparing the effects of LPS from non-periodontal bacteria (Escherichia coli and Salmonella enteritidis) with the LPS from periodontal pathogens, we found that the ratio of t-PA to PAI-2 was greater following exposure of the cells to LPS from periodontal pathogens. The highest ratio of t-PA to PAI-2 was found in those cells exposed to LPS from P. gingivalis. These results indicate that LPS derived from periodontal pathogens may cause unbalanced regulation of plasminogen activator and plasminogen activator inhibitor by HGF and such an effect may, in part, contribute to the destruction of periodontal connective tissue through dysregulated pericellular proteolysis.

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The effects of laser phototherapy on the release of growth factors by human gingival fibroblasts were studied in vitro. Cells from a primary culture were irradiated twice (6 h interval), with continuous diode laser [gallium-aluminum-arsenium (GaAlAs), 780 nm, or indium-gallium-aluminum-phosphide (InGaAlP),_660 nm] in punctual and contact mode, 40 mW, spot size 0.042 cm(2), 3 J/cm(2) and 5 J/cm(2) (3 s and 5 s, respectively). Positive [10% fetal bovine serum (FBS)] and negative (1%FBS) controls were not irradiated. Production of keratinocyte growth factor (KGF) and basic fibroblast growth factor (bFGF) was quantified by enzyme-linked immunosorbent assay (ELISA). The data were statistically compared by analysis of variance (ANOVA) followed by Tukey`s test (P a parts per thousand currency signaEuro parts per thousand 0.05). The characterization of the cell line indicated a mesenchymal nature. KGF release was similar in all groups, while that of bFGF was significantly greater (1.49-times) in groups treated with infra-red laser. It was concluded that increased production of bFGF could be one of the mechanisms by which infra-red laser stimulates wound healing.

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Cell-surface proteoglycans participate in several biological functions including interactions with a variety of growth factors and cytokines. Regulation of syndecan-1 and -2 gene expression was investigated in human periodontal ligament fibroblasts (PDLF), osteoblasts (OB) and gingival fibroblasts (GF), in response to platelet-derived growth factor (PDGF-BB), transforming growth factor (TGF-beta(1)), and interleukin (IL-1beta) by Northern blot analyses. We also compared the effect of PDGF-BB and TGF-beta(1), separately and in combination, in the prolonged presence of IL-1beta on the expression of both syndecan genes. The results demonstrated that the three cell lines regulated the expression of syndecan-1 and -2 in response to growth factors and cytokines in different manners. These cell lines increased syndecan-1 mRNA levels in response to either PDGF-BB or TGF-beta(1) and decreased levels in response to IL-1beta. The effect of IL-1beta on syndecan-1 mRNA synthesis was partially reversed after adding PDGF-BB and TGF-beta(1), separately or in combination, in the presence of IL-1beta. In contrast, syndecan-2 mRNA level was markedly upregulated in response to either TGF-beta(1) or IL-1beta in OB when compared with the other two cell lines. However, the stimulatory effect of TGF-beta(1) on syndecan-2 mRNA production in OB was abolished in the prolonged presence of IL-1beta. These findings lend support to the notion that syndecan-1 and syndecan-2 have distinct functions which correlate with their source and functions within the periodontium.

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Background: Growth hormone (GH) is a potent regulator of bone formation. The proposed mechanism of GH action is through the stimulation of osteogenic precursor Cell proliferation and, following clonal expansion of these cells. promotion of differentiation along the osteogenic lineage. Objectives: We tested this hypothesis by studying the effects of GH on primary cell populations of human periodontal ligament cells (PLC) and alveolar bone cells (ABC), which contain a spectrum of osteogenic precursors. Method: The cell populations were assessed for mineralization potential after long-term culture in media containing beta-glycerophosphate and ascorbic acid, by the demonstration of mineral deposition by Von Kossa staining. The proliferative response of the cells to GH was determined over a 48-h period using a crystal violet dye-binding assay. The profile of the cells in terms of osteogcnic marker expression was established using quantitative reverse transcriptase polymerase chain reaction (RT-PCR) for alkaline phosphatase (ALP), osteopontin. osteocalcin, bone sialoprotein (BSP), as well as the bone morphogenetic proteins BMP-2, BMP-4 and BMP-7. Results: As expected, a variety of responses were observed ranging from no mineralization in the PLC populations to dense mineralized deposition observed in one GH-treated ABC population. Over a 48-h period GH was found to be non-mitogenic for all cell populations. Quantitative reverse transcriptase polymerase chain reaction (RT-PCR) BSP mRNA expression correlated well with mineralizing potential of the cells. The change in the mRNA expression of the osteogenic markers was determined following GH treatment of the cells over a 48-h period. GH caused an increase in ALP in most cell populations, and also in BMP expression in some cell populations. However a decrease in BSP. osteocalcin and osteopontin expression in the more highly differentiated cell populations was observed in response to GH. Conclusion: The response of the cells indicates that while long-term treatment with GH may promote mineralization, short-term treatment does not promote proliferation of osteoblast precursors nor induce expression of late osteogenic markers.

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Reconstruction of large oral mucosa defects is often challenging, since the shortage of healthy oral mucosa to replace the excised tissues is very common. In this context, tissue engineering techniques may provide a source of autologous tissues available for transplant in these patients. In this work, we developed a new model of artificial oral mucosa generated by tissue engineering using a fibrin-agarose scaffold. For that purpose, we generated primary cultures of human oral mucosa fibroblasts and keratinocytes from small biopsies of normal oral mucosa using enzymatic treatments. Then we determined the viability of the cultured cells by electron probe quantitative X-ray microanalysis, and we demonstrated that most of the cells in the primary cultures were alive and had high K/Na ratios. Once cell viability was determined, we used the cultured fibroblasts and keratinocytes to develop an artificial oral mucosa construct by using a fibrin-agarose extracellular matrix and a sequential culture technique using porous culture inserts. Histological analysis of the artificial tissues showed high similarities with normal oral mucosa controls. The epithelium of the oral substitutes had several layers, with desmosomes and apical microvilli and microplicae. Both the controls and the oral mucosa substitutes showed high suprabasal expression of cytokeratin 13 and low expression of cytokeratin 10. All these results suggest that our model of oral mucosa using fibrin-agarose scaffolds show several similarities with native human oral mucosa.

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Background: the effect of triclosan plus the cationic detergent cetylpyridinium chloride (CPC) was evaluated for prostaglandin inhibition in human gingival fibroblasts. Since triclosan has previously been shown to inhibit proinflammatory cytokine induced prostaglandin E-2 (PGE(2)) production, we wanted to determine if triclosan, in the presence of CPC, could enhance these effects.Methods: Initial studies determined that both triclosan and CPC were cytotoxic to human gingival fibroblasts in concentrations exceeding 1.0 mu g/ml for either agent longer than 24 hours in a tissue culture. Therefore, subsequent studies measuring prostaglandin biosynthesis and cyclooxygenase (COX)-1 and COX-2 mRNA expression were performed in concentrations and times that did not significantly affect cell viability.Results: PGE2 biosynthesis was dose dependently inhibited by both triclosan and triclosan and CPC when challenged by tumor necrosis factor (TNF)-alpha or interleukin (IL)-1 beta. At pharmacologically relevant concentrations, triclosan and CPC inhibited ILAP-induced PGE(2) production to a greater extent than triclosan alone (P = 0.02). Moreover, enhanced COX-2 mRNA repression was observed with triclosan and CPC in comparison to triclosan alone in IL-1 beta and TNF-alpha stimulated cells. No effect on COX-I gene expression was observed. Further analysis of cell signaling mechanisms of triclosan and CPC indicates that nuclear factor-kappa B (NF-kappa B) and not p38 mitogen-activated protein kinase (MAPK) signaling may be impaired in the presence of triclosan and CPC.Conclusion: This study indicates that triclosan and CPC are more effective at inhibiting PGE(2) at the level of COX-2 gene regulation, and this combination may offer a potentially better anti -inflammatory agent in the treatment of inflammatory lesions in the oral cavity.

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Adipokines, such as nicotinamide phosphoribosyltransferase (NAMPT), are molecules, which are produced in adipose tissue. Recent studies suggest that NAMPT might also be produced in the tooth-supporting tissues, that is, periodontium, which also includes the gingiva. The aim of this study was to examine if and under what conditions NAMPT is produced in gingival fibroblasts and biopsies from healthy and inflamed gingiva. Gingival fibroblasts produced constitutively NAMPT, and this synthesis was significantly increased by interleukin-1β and the oral bacteria P. gingivalis and F. nucleatum. Inhibition of the MEK1/2 and NFκB pathways abrogated the stimulatory effects of F. nucleatum on NAMPT. Furthermore, the expression and protein levels of NAMPT were significantly enhanced in gingival biopsies from patients with periodontitis, a chronic inflammatory infectious disease of the periodontium, as compared to gingiva from periodontally healthy individuals. In summary, the present study provides original evidence that gingival fibroblasts produce NAMPT and that this synthesis is increased under inflammatory and infectious conditions. Local synthesis of NAMPT in the inflamed gingiva may contribute to the enhanced gingival and serum levels of NAMPT, as observed in periodontitis patients. Moreover, local production of NAMPT by gingival fibroblasts may represent a possible mechanism whereby periodontitis may impact on systemic diseases.

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In this study, oral carcinoma cells were used to evaluate chloroaluminum-phthalocyanine encapsulated in liposomes as the photosensitizer agent in support of photodynamic therapy (PDT). The genotoxicity and cytotoxicity behavior of the encapsulated photosensitizer in both dark and under irradiation using the 670-nm laser were investigated with the classical trypan blue cell viability test, the acridine orange/ethidium bromide staining organelles test, micronucleus formation frequency, DNA fragmentation, and cell morphology. The cell morphology investigation was carried out using light and electronic microscopes. Our findings after PDT include reduction in cell viability (95%) associated with morphologic alterations. The neoplastic cell destruction was predominantly started by a necrotic process, according to the assay with acridine orange and ethidium bromide, and this was confirmed by electronic microscopy analysis. Neither the PDT agent nor laser irradiation alone showed cytotoxicity, genotoxicity, or even morphologic alterations. Our results reinforce the efficiency of tight-irradiated chloroaluminum-phthalocyanine in inducing a positive effect of PDT. (C) 2008 Elsevier Ltd. All rights reserved.

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The pathways involved in the maintenance of human embryonic stem (hES) cells remain largely unknown, although some signaling pathways have been identified in mouse embryonic stem (mES) cells. Fibroblast feeder layers are used to maintain the undifferentiated growth of hES cells and an examination of the conditioned media (CM) of human neonatal fibroblasts (HNFs) could provide insights into the maintenance of hES cells. The neonatal foreskin fibroblast line (HNF02) used in this study was shown to have a normal 2n = 46, XY chromosomal complement and to support the undifferentiated growth of the Embryonic Stem Cell International Pte. Ltd.-hES3 cell line. The CM of HNF02 was examined using two-dimensional liquid chromatography-tandem mass spectrometry (2-D LCMS) and two-dimensional electrophoresis (2-DE) followed by matrix-assisted laser desorption/ionization-time of flight tandem mass spectrometry (2-DE/MALDI). A total of 102 proteins were identified, 19 by 2-DE/MALDI, 53 by 2-D LCMS and 30 by both techniques. These proteins were classified into 15 functional groups. Proteins identified in the extracellular matrix and differentiation and growth factor functional categories were considered most likely to be involved in the maintenance of hES cell growth, differentiation and pluripotency as these groups contained proteins involved in a variety of events including cell adhesion, cell proliferation and inhibition of cell proliferation, Writ signaling and inhibition of bone morphogenetic proteins.

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Little is known about the physiological mechanisms related to low-intensity laser therapy (LILT), particularly in acute inflammation and subsequent wound healing. The objective of this study was to verify the effect of LILT on mast cell degranulation. Epulis fissuratum tissues from eight patients were used. One part of the lesion was irradiated with an AsGaAl laser (lambda = 670 nm, 8.0 J/cm(2), 5 mW, 4 min). The other part was not irradiated. Then, the specimens were immediately removed, fixed and examined by light microscopy. The number of mast cells was similar in laser-treated samples when compared with non-irradiated specimens. The degranulation indexes of the mast cells observed in the irradiated samples were significantly higher than those of controls (P < 0.05). LILT with the parameters used increased the number of degranulated mast cells in oral mucosa.

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The possibility of obtaining transplantable oral epithelia opens new perspectives for oral treatments. Most of them are surgical, resulting in mucosal failures. As reconstructive material this in vitro epithelia would be also useful for other parts of the human body. Many researchers still use controversial methods; therefore it was evaluated and compared the efficiency of the enzymatic and direct explant methods to obtain oral keratinocytes. To this project oral epithelia fragments were used. This work compared: time needed for cell obtainment, best cell amount, life-span and epithelia forming cell capacity. The results showed the possibility to obtain keratinocytes from a small oral fragment and we could verify the advantages and peculiar restrictions. We concluded that under our conditions the enzymatic method showed the best results: in the cells obtaining time needed, cell amount and life-span. Both methods showed the same capacity to form in vitro epithelia.

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Use of specific histone deacetylase inhibitors has revealed critical roles for the histone deacetylases (HDAC) in controlling proliferation. Although many studies have correlated the function of HDAC inhibitors with the hyperacetylation of histones, few studies have specifically addressed whether the accumulation of acetylated histones, caused by HDAC inhibitor treatment, is responsible for growth inhibition. In the present study we show that HDAC inhibitors cause growth inhibition in normal and transformed keratinocytes but not in normal dermal fibroblasts, This was despite the observation that the HDAC inhibitor, suberic bishydroxamate (SBHA), caused a kinetically similar accumulation of hyperacetylated histones, This cell type-specific response to SBHA was not due to the inactivation of SBHA by fibroblasts, nor was it due to differences in the expression of specific HDAC family members. Remarkably, overexpression of HDACs 1, 4, and 6 in normal human fibroblasts resulted in cells that could be growth-inhibited by SBHA. These data suggest that, although histone acetylation is a major target for HDAC inhibitors, the accumulation of hyperacetylated histones is not sufficient to cause growth inhibition in all cell types, This suggests that growth inhibition, caused by HDAC inhibitors, may be the culmination of histone hyperacetylation acting in concert with other growth regulatory pathways.