p38 MAPK在LPS诱导牙龈成纤维细胞表达uPA中作用的研究

目的：研究p38 MAPK在LPS诱导牙龈成纤维细胞表达uPA中的作用。方法：采用Western blotting观察LPS对牙龈成纤维细胞内p38 MAPK活性的影响；蛋白激酶活性实验SB203580地p38 MAPK活性的抑制作用；Northern blotting观察SB203580对LPS诱导uPA表达的影响。结果：LPS能够迅速地激活牙龈成纤维细胞内p38 MAPK的活性；SB203580能够有效地抑制牙龈成纤维细胞内的p38 MAPK的活性；经SB203580处理后，LPS对uPA的诱导作用受到显著的抑制。结论：LPS通过p38 MAPK信号转导途径诱导牙龈成纤维细胞表达uPA。     

Regulation of TNF-alpha-induced IL-6 production in MG-63 human osteoblast-like cells

Tumor necrosis factor-alpha (TNF-alpha) stimulates osteoblast production of interleukin-6 (IL-6), an inflammatory cytokine implicated in osteoclastic bone resorption. Therefore, we tested the hypothesis that TNF-alpha-induced IL-6 production in MG-63 osteosarcoma cells occurs via the p38 mitogen-activated protein kinase (MAPK) pathway. TNF-alpha activated p38 MAPK and stimulated IL-6 secretion by MG-63 cells, and pre-incubation of cells with the p38 MAPK inhibitor abrogated TNF-alpha-dependent IL-6 secretion. Transfection of IL-6 full-length and 5-deletion gene promoter reporter constructs indicated that p38 MAPK activation by TNF-alpha enhanced IL-6 gene expression, and that the p38 MAPK-responsive region resided in the proximal 260-bp segment. Transfection of NFkappaB and C/EBPbeta-sensitive reporter promoter constructs demonstrated that NFkappaB activity was enhanced and that constitutive C/EBPbeta was inhibited by TNF-alpha, with both effects being p38 MAPK-dependent. In conclusion, although p38 MAPK activation by TNF-alpha stimulates IL-6 secretion by MG-63 cells, it has opposing effects on c/EBPbeta and NFkappaB activity.     

Gamma-interferon enhances expression of CD14/MyD88 and subsequent responsiveness to lipopolysaccharide from Actinobacillus actinomycetemcomitans in human gingival fibroblasts

OBJECTIVES: CD14, toll-like receptor 4 (TLR4) and MyD88 have been shown to mediate responsiveness in host cells to lipopolysaccharide. We investigated here the regulatory effects of inflammatory cytokines on the expression of membrane CD14 (mCD14), TLR4 and MyD88, and on subsequent responsiveness to lipopolysaccharide from Actinobacillus actinomycetemcomitans in human gingival fibroblasts. MATERIALS AND METHODS: Following treatment with either interleukin-1beta, tumor necrosis factor-alpha (TNF-alpha) or gamma-interferon (IFN-gamma), expression of mCD14/TLR4 and MyD88 was determined by flow cytometry and western blotting, respectively. After pretreatment with IFN-gamma, cells were pre-incubated with either anti-CD14 antibody MY4 or anti-TLR4 antibody HTA125 and subsequently treated with A. actinomycetemcomitans lipopolysaccharide. Then, phosphorylation of mitogen-activated protein (MAP) kinases and IkappaBalpha was examined by western blotting, and production of interleukin-6 and interleukin-8 was measured by their respective enzyme-linked immunosorbent assay (ELISA) kits. RESULTS: IFN-gamma stimulated expression of mCD14, whereas -1beta and TNF-alpha did not. Expression of MyD88 but not TLR4 was also enhanced by IFN-gamma. The lipopolysaccharide activated MAP kinases, such as extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38, and IkappaBalpha and stimulated production of interleukin-6 and interleukin-8. The lipopolysaccharide-stimulated interleukin-6 and interleukin-8 production was markedly inhibited by MY4 or HTA125. Pretreatment with IFN-gamma augmented the following activation of MAP kinases and IkappaBalpha and production of interleukin-6 and interleukin-8 in response to the lipopolysaccharide. CONCLUSIONS: These results suggest that the augmentation by IFN-gamma of the responsiveness to A. actinomycetemcomitans lipopolysaccharide, such as activation of MAP kinases and IkappaBalpha and terminal cytokine production in human gingival fibroblasts, may be partially mediated by up-regulation of CD14 and MyD88 expression.     

Tumor necrosis factor-alpha and its receptors, p55 and p75, in gingiva of adult periodontitis

Tumor necrosis factor-alpha (TNF-alpha), a pro-inflammatory cytokine, can stimulate matrix metalloproteinase synthesis and osteoclastic bone resorption. We hypothesized that elevated expression of TNF-alpha and its p55 and p75 receptors (TNF-R) in gingival tissue might associate with periodontitis. Immunohistochemistry was used for the study of the localization of TNF-alpha and its p55 and p75 TNF-R in adult periodontitis (AP) gingival tissue, in comparison with that in healthy control specimens. TNF-alpha and p55 TNF-R were detected in sulcular epithelial basal cells and in monocyte/macrophages, fibroblasts, and endothelial cells in the AP gingival tissue specimens, but mainly in fibroblasts and endothelial cells in control specimens. P75 TNF-R was occasionally found in monocyte/macrophage-like cells in gingival tissue specimens. The percentage of TNF-alpha-containing cells was not increased in AP compared with controls (13.2%+/-6.1% vs. 12.8%+/-7.6%), but, due to the increased cellularity of AP samples, the number of TNF-alpha positive cells/mm2 was clearly increased (1621+/-663 vs. 664+/-191, p > 0.001). Thus, AP gingival tissue has an elevated expression of TNF-alpha and especially its p55 receptor, suggesting that TNF-alpha may contribute to tissue degradation in periodontitis.     

白藜芦醇对高糖环境下牙龈上皮细胞TLR4表达及炎症因子分泌的影响

目的:研究白藜芦醇对高糖环境下牙龈上皮细胞TLR4表达及炎症因子分泌的影响,探讨白藜芦醇对伴糖尿病牙周炎患者的治疗作用及相关分子机制.方法:体外培养牙龈上皮细胞,按照作用方式不同分为正常对照组、高糖组和高糖+白藜芦醇组.荧光定量PCR检测TLR4表达情况;取第3代牙龈上皮细胞,高糖环境下采用或不采用白藜芦醇处理24 h,随后用100 ng/mL LPS处理2 h,ELISA检测IL-1β 、IL-6、IL-8和TNF-α分泌;Western印迹法检测TLR4信号通路下游分子NF-κB p65、p38MAPK和STAT3磷酸化.采用SPSS 17.0软件包对数据进行统计学分析.结果:白藜芦醇可以逆转高糖环境下牙龈上皮细胞TLR4水平的升高,同时抑制高糖环境下LPS诱导的IL-1β、IL-6、IL-8和TNF-α表达.Western印迹结果显示,白藜芦醇也可抑制TLR4信号通路下游分子NF-κB p65、p38MAPK和STAT3磷酸化.结论:白藜芦醇通过负向调控TLR4信号通路减轻高糖环境下牙龈上皮细胞炎症因子的分泌.     

The induction expression of human β-defensins in gingival epithelial cells and fibroblasts

ObjectiveThe gingival epithelial cells and fibroblasts can produce antimicrobial peptides when stimulated by inflammatory cytokines. The purpose of the present study was to test whether gingival keratinocytes and gingival fibroblasts respond differently to inflammatory cytokine activation. This will enable us to understand the chronic inflammatory response in the process of periodontal disease.DesignGingival keratinocytes and fibroblasts were isolated and treated with different concentrations of IL-1β and quantitative real-time PCR was performed to evaluate the induced expressions of hBD-1, hBD-2 and hBD-3. The induced response was compared between the gingival epithelial cells and fibroblasts. The inhibitors of p38 protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) were applied to explore the molecular mechanism during the induction of hBDs in both cells.ResultsThe results showed that the hBDs expressions were found to be induced by different concentrations of IL-1β, but with several differences between gingival epithelial cells and fibroblasts. The hBDs mRNA expression in gingival fibroblasts was more sensitive compared with keratinocytes to different concentrations of IL-1β. The hBD-1 and hBD-3 expressions in these two cells were down-regulated by IL-1β and hBD-2 expression was up-regulated. The inflammatory cytokine IL-1β had dual effect on hBDs expression.ConclusionsThe gingival epithelial cells and fibroblasts respond differently to the inflammatory cytokine IL-1β which indicated different roles played by the two cells in the host defense. The dual effect of IL-1β on hBDs expression may contribute to the defensins down-regulation in periodontal disease.     

Signaling pathways regulating IL-1alpha-induced COX-2 expression

Interleukin-1alpha(IL-1alpha) stimulates the production of prostaglandin E(2) (PGE(2)) in odontogenic keratocyst fibroblasts. However, the signaling pathways remain obscure. In this study, we investigated IL-1alphasignaling pathways that regulate cyclooxygenase-2 (COX-2) expression in odontogenic keratocyst fibroblasts. IL-1alphaincreased the expression of COX-2 mRNA and protein, and PGE(2) secretion in the fibroblasts. IL-1alphaincreased the phosphorylation of extracellular signal-regulated protein kinase-1/2 (ERK1/2), p38 mitogen-activated protein kinase (MAPK), and c-Jun N-terminal kinase (JNK). PD-98059, SB-203580, SP-600125, and PDTC-which are inhibitors of ERK1/2, p38, JNK, and nuclear factor-kappaB (NF-kappaB), respectively-attenuated the IL-1alpha-induced COX-2 mRNA expression and activated protein kinase C PGE(2) secretion. IL-1alpha(PKC), and PKC inhibitor staurosporine inhibited IL-1alpha-induced phosphorylation of ERK1/2, p38, and JNK, and decreased IL-1alpha-induced COX-2 mRNA expression. Thus, in odontogenic keratocyst fibroblasts, IL-1alphamay stimulate COX-2 expression both through the PKC-dependent activation of ERK1/2, p38, and JNK signaling pathways, and through the NF-kappaB cascade.     

Interferon-γ stimulates CD14, TLR2 and TLR4 mRNA expression in gingival fibroblasts increasing responsiveness to bacterial challenge

ObjectiveTo investigate the potential effects of IFN-03A5 on the responsiveness of human gingival fibroblasts to bacterial challenge.DesignmRNA and protein expression of CD14, TLR2 and TLR4 in human gingival fibroblasts was detected by quantitative polymerase chain reaction (Q-PCR) and flow cytometry. The effect of preincubation with IFN-03A5 on subsequent bacterial LPS-induced expression of IL-6 and IL-8 by gingival fibroblasts was determined by ELISA. Bacterial LPS-induced IκBα degradation in human gingival fibroblasts was investigated by western blot.ResultsHuman gingival fibroblasts express CD14, TLR2 and TLR4 mRNAs. IFN-03A5, but not IL-103B2, induced mRNA expression of all three receptors and the expression of membrane bound CD14 protein. Pre-incubation of fibroblasts with IFN-03A5 and subsequent stimulation with Escherichia coli LPS or Porphyromonas gingivalis LPS led to increased production of IL-6 and IL-8. LPS-induced pro-inflammatory cytokine production was abrogated by a blocking antibody to CD14. Both E. coli LPS and P. gingivalis LPS induced IκBα degradation in human gingival fibroblasts.ConclusionOur data indicate that IFN-03A5 primes human gingival fibroblasts, through the upregulation of CD14 expression, which results in increased responsiveness to bacterial LPS challenge, as determined by pro-inflammatory cytokine production.     

High IL-6 synthesis in cultured fibroblasts isolated from radicular cysts

OBJECTIVE: Inflammatory cytokines have been reported to be related with inflammation and expansion of jaw cysts. In this study, to examine the relationship between radicular cysts and inflammatory cytokines, it was found that there was notable unique evidence on cytokine synthesis from fibroblasts isolated from radicular cysts. METHODS: The expression of such cytokines, namely, interleukin-1beta, IL-1beta, IL-6, IL-8, IL-10, tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), transforming growth factor-beta1 (TGF-beta1), and granulocyte-macrophage colony-stimulating (GM-CSF) mRNA, in nine radicular cysts was examined and compared with that detected in six specimens of healthy gingival mucosa. Furthermore, separating all fibroblasts from their respective radicular cysts, healthy gingival mucosa, and healthy periodontal ligaments, these fibroblast groups were cultured without stimulators and a supernatant for each was obtained to analyse IL-1beta, IL-6, IL-8, TNF-alpha, and IFN-gamma by ELISA. RESULTS: Differences between radicular cysts and healthy gingival mucosa were not clearly shown by the expression of cytokine mRNA. Analysing inflammatory cytokine synthesis in fibroblast groups from these three kinds of tissues, surprisingly, the levels of IL-6 mRNA and protein were recognised to be higher in fibroblasts of radicular cysts than in those of control tissues by ELISA and a real-time RT-PCR. Significant differences in the cultured supernatants of these fibroblast groups were not recognised in the release of IL-1beta, IL-8, TNF-alpha, and IFN-gamma by ELISA. CONCLUSIONS: From these results, it was suggested that fibroblasts inducing IL-6 production might play important roles in the expansion of radicular cysts. It is considered that fibroblasts around radicular cysts may lead to high IL-6 synthesis over time in chronic inflammation.     

一氧化碳对炎症环境下人牙龈成纤维细胞黏附分子表达影响的机制研究

目的 研究一氧化碳对炎症环境下人牙龈成纤维细胞（HGF）黏附分子表达影响的分子机制。方法 体外培养HGF,以50 ng•mL-1的TNF-α和10 ng•mL-1的IL-1β刺激加入或不加入500 μmol•L-1一氧化碳释放分子-3（CORM-3）的HGF;分别在刺激10、20 min后收集部分细胞,用Western blot法检测丝裂原激活蛋白激酶（MAPK）通路中细胞外调节蛋白激酶（ERK）、c-Jun氨基末端激酶（JNK）和p38的磷酸化水平;在刺激4 h后用Western blot法检测核转录因子-κB（NF-κB）的核内表达;在部分实验中,HGF在TNF-α、IL-1β及CORM-3刺激前以鸟苷酸环化酶特异性抑制剂1H-[1,2,4]噁二唑[4,3-α]喹喔啉-1-酮（ODQ）预处理8 h,刺激24 h后用Western blot法检测细胞间黏附分子-1（ICAM-1）的表达。结果 在TNF-α和IL-1β刺激细胞10 min后,MAPK通路中p38、ERK和JNK的磷酸化水平即有明显升高,CORM-3能够明显抑制p38的磷酸化,而对ERK和JNK的磷酸化水平无明显影响;4 h后,CORM-3可明显抑制NF-κB-p65的核内表达。ODQ不能改变CORM-3对TNF-α和IL-1β共同刺激下ICAM-1表达水平的影响,说明CORM-3的作用并非通过鸟苷酸环化酶系统实现。结论 一氧化碳对炎症环境下HGF黏附分子表达的抑制作用可能是通过对NF-κB的活性抑制和对MAPK p38磷酸化水平的抑制作用来实现的。     

牡荆素对脂多糖诱导牙髓干细胞表达炎症因子的影响

目的：探讨牡荆素（vitexin,VTX）对脂多糖（lipopolysaccharide,LPS）诱导的人牙髓干细胞（human dental stem pulp cells,hDPSCs）表达炎症因子的影响,并初步探讨其相关作用机制。方法：分离、培养hDPSCs,以CCK-8法检测VTX对hDPSCs增殖的影响,检测VTX毒性浓度范围。铺种hDPSCs,分为4组,空白组以不含LPS和VTX的无血清DMEM,LPS组仅加入含LPS终浓度为2 μg/mL的无血清DMEM培养,VTX处理组1(V1组)加入2 μg/mL LPS+25 μmol/L VTX,VTX处理组2(V2组)加入2 μg/mL LPS + 50 μmol/L VTX。培养48 h,实时荧光定量PCR检测各组细胞中IL-1β、IL-6及IL-8基因转录,蛋白质免疫印迹检测hDPSCs内MPAK信号通路及COX-2等蛋白的变化。采用SPSS 16.0软件包对数据进行统计学分析。结果：VTX在200 μmol/L范围内时细胞活力不受影响(P>0.05);VTX抑制LPS刺激hDPSCs转录IL-1β、IL-6及IL-8,抑制效果与VTX的浓度呈正相关;VTX可显著抑制LPS激活p38及ERK信号通路。结论：VTX可能通过抑制p38及ERK信号通路的激活,降低LPS诱导的hDPSCs转录IL-1β、IL-6及IL-8。     

Cyclosporin A inhibits collagenase gene expression via AP-1 and JNK suppression in human gingival fibroblasts

A frequent side effect of cyclosporin A (CsA) administration is gingival overgrowth. Although the molecular mechanisms of CsA-induced gingival overgrowth are still unknown, it has been postulated that CsA acts on lipopolysaccharide (LPS) to induce fibroblastic activity, which results in an increase of the extracellular matrix. Here we provide evidence that CsA is able to affect signal transduction of LPS-induced collagenase expression in fibroblasts. Treatment of fibroblasts with LPS caused activation of collagenase gene, activator protein-1 (AP-1) and c-Jun N-terminal kinase (JNK). These activations were blocked by CsA. We suggest that inhibitory effects of CsA on LPS-induced signal transduction may contribute to the mechanism of CsA-induced gingival overgrowth.     

Interleukin-1beta induces matrix metalloproteinase-1 expression in cultured human gingival fibroblasts: role of cyclooxygenase-2 and prostaglandin E2

OBJECTIVE: Matrix metalloproteinases (MMPs) degrade extracellular matrices and are responsible for excessive connective tissue breakdown in inflammatory disorders. We investigated the mechanism of MMP-1 expression in human gingival fibroblasts in response to the stimulation with interleukin-1beta (IL-1beta), and the role of inducible-type cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2) in the regulation of MMP-1 expression. MATERIALS AND METHODS: We stimulated cultured human gingival fibroblasts with r(h)IL-1beta, and examined the expression of MMP-1 mRNA and protein by quantitative polymerase chain reaction and enzyme-linked immunosorbent assay. The effect of indomethacin, dexamethasone, or cycloheximide (CHX) on the IL-1beta-induced expression of MMP-1 was examined. The expression of MMP-1 in gingival fibroblasts stimulated with PGE2 was also examined. RESULTS: IL-1beta stimulated the expressions of mRNA and protein for MMP-1, in cultured fibroblasts, in time- and concentration-dependent manners. Pretreatment of the cells with indomethacin or dexamethasone inhibited the IL-1beta-induced MMP-1 expression. CHX, a protein synthesis inhibitor, also suppressed the MMP-1 expression. IL-1beta also induced COX-2 expression in gingival fibroblasts, and PGE2, a major COX-2 product, was found to enhance MMP-1 expression. CONCLUSION: The IL-1beta-induced MMP-1 expression in gingival fibroblasts may be mediated, at least in part, by COX-2 and its product PGE2.     

Prostaglandin production by human gingival fibroblasts inhibited by triclosan in the presence of cetylpyridinium chloride

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 E2 (PGE2) 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 microg/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)-1beta. At pharmacologically relevant concentrations, triclosan and CPC inhibited IL-1beta-induced PGE2 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-1beta and TNF-alpha stimulated cells. No effect on COX-1 gene expression was observed. Further analysis of cell signaling mechanisms of triclosan and CPC indicates that nuclear factor-kappa B (NF-kappaB) 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 PGE2 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.