牙龈卟啉单胞菌膜泡对牙龈上皮细胞MMPs基因表达的影响

目的:探讨牙龈卟啉单胞菌膜泡对牙龈上皮细胞基质金属蛋白酶(MMPs)基因表达的影响,揭示牙龈卟啉单胞菌在牙周炎中的致病作用.方法:以Real-time RT-PCR法检测牙龈卟啉单胞菌膜泡刺激下牙龈上皮细胞MMP-1和MMP-3的mRNA表达水平.结果:牙龈卟啉单胞菌膜泡显著地上调MMP-1和MMP-3 mRNA表达水平.结论:牙龈卟啉单胞菌诱导牙龈上皮细胞发生细胞炎症反应,可能是牙周炎发生、发展的重要因素.     

牙龈卟啉单胞菌膜泡诱导牙龈上皮细胞炎性反应的体外研究

目的建立牙龈卟啉单胞菌膜泡诱导牙龈上皮细胞炎性反应的体外模型，探讨牙龈卟啉单胞菌在牙周炎中的致病作用。方法用酶联免疫吸附法检测牙龈卟啉单胞菌膜泡对牙龈上皮细胞前列腺素E2（prostaglandin E2，PGE2）分泌的影响，以实时反转录聚合酶链反应法检测牙龈卟啉单胞菌膜泡对牙龈上皮细胞环氧化物酶（cyclooxygenase，COX）-2和白细胞介素（interleukin，IL）-6、IL-8基因表达的作用。结果牙龈卟啉单胞菌膜泡浓度依赖性地促进了牙龈上皮细胞PGE2的分泌，并使COX-2、IL-6、IL-8的mRNA表达水平显著上调。结论牙龈卟啉单胞菌膜泡诱导牙龈上皮细胞发生的细胞炎性反应，可能是牙周炎发生、发展的重要因素。     

LPS刺激对体外培养人牙龈成纤维细胞环氧合酶表达的影响

目的检测脂多糖（LPS）刺激后体外培养人牙龈成纤维细胞环氧合酶-1和环氧合酶-2（COX-1,COX-2）表达的改变,探讨牙龈成纤维细胞与牙周炎症发生发展的关系。方法组织块法原代培养正常人牙龈成纤维细胞并进行来源鉴定,MTT法检测不同浓度LPS刺激后活细胞数量的改变;以10ug/ml刺激第4代细胞,24h后用免疫细胞化学方法检测COX-1和COX-2在细胞中的表达,多功能彩色细胞分析管理系统进行图像分析和统计学分析。结果 LPS刺激可使牙龈成纤维细胞的增殖速度降低,生长曲线大致呈＂S＂形;10ug/ml LPS刺激24h后细胞数量未见明显变化。免疫细胞化学染色结果显示COX-1在LPS刺激前后均有表达但无显著差异（P〉0.05）,COX-2在LPS刺激前无表达,LPS刺激后则表达增强并有显著差异（P〈0.01）。结论 LPS对牙龈成纤维细胞生长增殖有抑制作用,不影响COX-1的表达强度,但可使COX-2表达显著增强,说明牙龈成纤维细胞对LPS刺激的反应可能影响牙周炎症进展。     

白细胞介素-1β对遗传性牙龈纤维瘤和正常牙龈上皮细胞β-防御素的影响

目的:比较白细胞介素1β(IL-1β)刺激体外培养的正常牙龈、遗传性牙龈纤维瘤(HGF)上皮细胞β-防御素(HBD)表达的差异,探讨该差异与遗传性牙龈纤维瘤发病机制的可能相关性。方法:体外培养3例遗传性牙龈纤维瘤病人和6例正常人牙龈上皮细胞,经0,0.01,0.1,1,10,100 ng/mL的IL-1β分别刺激12、24、36、48 h,提取细胞总RNA,逆转录后,采用HBD-1、2、3特异性引物经PCR扩增,以β-肌动蛋白为内参,计算HBD-1、2、3与内参扩增产物相对值,对HBD-1、2、3进行半定量分析,采用SPSS软件单向方差统计分析法分析结果。结果:HBD-1 mRNA在正常牙龈和遗传性牙龈纤维瘤上皮细胞中呈固有表达,不受IL-1β刺激的影响。IL-1β可上调两种牙龈上皮细胞HBD-2、3的表达,在浓度为0.1～10 ng/mL时,作用时间大于12 h,受刺激组与未受刺激组差异有显著性(P<0.01)。相同浓度IL-1β作用不同时间时,正常牙龈上皮细胞中HBD-2、3的表达水平显著高于遗传性牙龈纤维瘤上皮细胞中表达水平(P<0.05,P<0.01)。且随作用时间延长差异更加显著。结论:遗传性牙龈纤维瘤病变组织和正常牙龈组织中β-防御素的表达有差异,这种差异可能与遗传性牙龈纤维瘤上皮细胞的分化及发病机制相关。     

牙龈组织炎症程度与COX-2蛋白表达的关系

目的:运用免疫组化技术观察牙龈组织中COX-2的表达,探讨COX-2与牙周病的关系。方法:首先对选用组织采用普通苏木素-伊红(HE)制片,观察炎症细胞浸润程度,根据炎症水平高低,选择两组进一步进行免疫组化检测,结果与正常组织相比较。结果:实验组COX-2蛋白表达要明显高于对照组(P<0.01)。结论:COX-2表达与炎症程度有关,炎症程度越高,COX-2表达也越高,两者呈正相关。     

重组人β防御素3对牙龈卟啉单胞菌脂多糖致炎作用的影响

目的:以牙龈卟啉单胞菌脂多糖(P.g-LPS)诱发载脂蛋白E基因敲除(ApoE-/-)小鼠和RAW264.7小鼠单核巨噬细胞的急性炎症反应,并应用重组人β防御素3(rhBD3),观察其对炎症的干预效果。方法:20周龄雄性ApoE-/-小鼠随机均分为PBS对照组、P.g-LPS组和P.g-LPS+rhBD3组,分别经腹腔注射给药2h后,检测血清中不同炎症指标(MCP-1、TNF-α、IL-6、IL-1β和NO)的水平。同时,以rhBD3干预P.g-LPS对RAW264.7细胞的致炎作用,分别检测培养上清和细胞中炎症指标的水平及其mRNA的相对表达量。结果:经P.g-LPS刺激后,ApoE-/-小鼠血清MCP-1、TNF-α、IL-6和NO的水平较对照组显著上调;而同时应用rhBD3能明显降低MCP-1、TNF-α和NO表达量。P.g-LPS能显著上调RAW264.7细胞培养上清中TNF-α和NO的水平以及细胞中TNF-α和IL-6的mRNA相对表达量,rhBD3对此具有抑制作用。结论:rhBD3对P.g-LPS在体内、外诱导的急性炎症具有一定的抑制效应,可能在牙周炎与高脂血症的相互作用中发挥免疫调节作用。     

老年牙周炎牙龈组织诱导型一氧化氮合酶分布研究

目的 :观察慢性老年牙周炎患者牙龈组织中诱导型一氧化氮合酶 (iNOS)分布。方法 :采用免疫组织化学方法对 10例慢性老年牙周炎患者、10例慢性成人牙周炎患者、10例青少年牙周炎患者和 10例健康老年人牙龈组织中诱导型一氧化氮合酶分布进行了检测并比较研究。结果 :(1)牙周炎时牙龈组织中诱导型一氧化氮合酶主要在鳞状上皮细胞胞浆核周区颗粒状阳性表达 ,毛细血管壁内皮细胞、老化的胶原纤维及上皮下基底膜共同形成了一种乳头状轮廓样阳性表达形态 ,结缔组织和肉芽组织中各类炎症细胞也显阳性表达 ;(2 )慢性老年牙周炎组血管壁内皮细胞、结缔组织内炎症细胞、上皮乳头阳性表达例数明显低于青少年牙周炎组和慢性成人牙周炎组 (P <0 .0 5 )。血管壁内皮细胞和胶原纤维阳性表达例数低于健康老年人组 (P <0 .0 5 )。结论 :慢性老年牙周炎患者牙龈组织中诱导型一氧化氮合酶的表达明显降低 ,造成了局部一氧化氮(NO)合成减少 ,引起了局部牙龈组织免疫功能降低和免疫调节功能紊乱     

RECK、MMP-2在牙周炎患者牙龈组织中的表达

目的:研究RECK蛋白和MMP-2在牙周炎中的表达及其相互关系。方法:应用免疫组化SP法检测56例牙周炎患者牙周组织和16例正常牙龈组织中RECK和MMP-2的表达。结果:RECK在16例正常牙龈组织中的阳性表达率100%,而在牙周炎牙龈组织中的阳性表达率为51.8%。MMP-2在正常牙龈组织中的阳性表达率为31.3%,而在牙周炎牙龈组织中的阳性表达率为76.8%。牙周炎中RECK与MMP-2的表达呈负相关(P<0.01,r=-0.300)。结论:RECK可能通过调控MMP-2来影响牙周炎的发生与发展。     

桦木酸调节血红素加氧酶-1降低脂多糖和尼古丁联合诱导的炎症反应

目的:研究桦木酸(BA)对尼古丁和脂多糖联合刺激引起的人牙周韧带细胞(PDLCs)的炎症反应调节作用机理。方法:MTT法检测BA对人牙周韧带细胞的毒性。免疫印迹(蛋白质印迹法)用于检测BA(10μmol/L)对LPS和尼古丁联合诱导的人PDLCs中环氧合酶-2(COX-2)、诱导型一氧化氮合酶(iNOS)和血红素加氧酶-1(HO-1)表达的影响。使用Griess试剂和ELISA监测促炎介质一氧化氮(NO)和前列腺素E2(PGE2)量的变化。结果:在对人PDLCs无明显细胞毒性的条件下,10μmol/L BA可降低细胞经LPS和尼古丁联合诱导的HO-1蛋白表达和活性,同时BA显著抑制尼古丁和LPS联合上调的人PDLCs中iNOS/NO和COX-2/PGE2产量。血红素,一种选择性HO-1诱导剂,逆转了BA对尼古丁和LPS联合诱导的炎症反应。结论:BA对人牙周韧带细胞具有抗炎活性,涉及调控HO-1发挥作用。BA在预防和治疗与吸烟和牙龈卟啉单胞菌感染相关的牙周病方面具有潜在的益处。     

牙周基础治疗对口腔扁平苔藓伴慢性牙周炎患者外周血MMP-3及IFN-γ水平的影响

目的:观察牙周基础治疗前后口腔扁平苔藓伴慢性牙周炎患者血清中基质金属蛋白酶-3(MMP-3)和干扰素-γ(IFN-γ)浓度的变化.方法:选取60例诊断为伴有牙周炎的糜烂型口腔扁平苔藓患者,随机分为2组,其中实验组30例进行牙周基础治疗联合药物治疗,治疗前后,检测牙周指数PD、AL、BI和PLI.对照组30例采取药物治疗.用ELLSA检测治疗前后2组患者血清中MMP-3及IFN-γ的表达水平,分析各组细胞因子浓度的差异.结果:治疗后实验组牙周指数明显下降(P＜0.05);2组患者血清中的MMP-3及IFN-γ表达水平与治疗前相比下降(P＜0.05);经过治疗后,实验组MMP-3及IFN-γ表达水平下降趋势较对照组明显(P＜0.05).结论:牙周基础治疗在口腔扁平苔藓治疗中起到了积极作用,可有效降低炎症水平.     

Enhanced cyclooxygenase-2 mRNA expression in human gingival fibroblasts induced by cell contact with human lymphocytes

Prostaglandins, especially prostaglandin E2 (PGE2), play a crucial role in the pathogenesis of periodontal disease. We have previously reported that inflammatory mediators interleukin-1 (IL-1) and tumor necrosis factor alpha (TNFalpha) increase the production of PGE2 in human gingival fibroblasts. In this study, we investigated the effect of cell-to-cell interactions between gingival fibroblasts and lymphocytes on PGE2 production by using co-culture technique. Cell-to-cell contact between gingival fibroblasts and lymphocytes synergistically enhanced the production of PGE2 in co-cultures. In contrast to lymphocytes, the cyclooxygenase-2 (COX-2) mRNA expression in gingival fibroblasts was strongly enhanced following cell contact between gingival fibroblasts and lymphocytes. The level of COX-1 mRNA expression, however, was not affected either in gingival fibroblasts or in lymphocytes by the interactions between fibroblasts and lymphocytes. The study demonstrates that cell contact between gingival fibroblasts and lymphocytes strongly stimulates PGE2 production partly due to enhanced COX-2 mRNA expression in gingival fibroblasts. The cell-to-cell contact between gingival fibroblasts and lymphocytes should be considered as an important regulatory aspect for the enhancement of PGE2 in periodontal disease.     

Triclosan reduces microsomal prostaglandin E synthase-1 expression in human gingival fibroblasts

OBJECTIVE: The effect of triclosan (2,4,4'-trichloro-2'-hydroxydiphenyl ether) on the expression of cyclooxygenase-2 (COX-2) and microsomal prostaglandin E synthase-1 (mPGES-1) and on the translocation of the nuclear factor-kappaB (NF-kappaB) in relation to prostaglandin E2 (PGE2) production was investigated in human gingival fibroblasts challenged with tumor necrosis factor alpha (TNFalpha). METHODS: Fibroblasts were established from gingival biopsies obtained from six children. COX-2 mRNA and protein expression was quantified using mRNA quantitation and enzyme immunometric assay kits. mPGES-1 mRNA was analysed by RT-PCR, mPGES-1 protein and NF-kappaB translocation by immunoblotting. PGE2 was determined by radioimmunoassay. RESULTS: The cytokine TNFalpha enhanced the expression of mRNA as well as the protein levels of both COX-2 and mPGES-1 and subsequently the production of PGE2 in gingival fibroblasts. Treatment of gingival fibroblasts with triclosan (1 microg/ml) significantly reduced the stimulatory effect of TNFalpha (10 ng/ml) on the expression of mPGES-1 at both the mRNA and the protein level by an average of 21% and 43%, respectively, and subsequently the production of PGE2 (p<0.01). Triclosan did not, however, affect the translocation of NF-kappaB or the expression of COX-2 in TNFalpha-stimulated cells. CONCLUSION: The results show that triclosan reduces the augmented biosynthesis of PGE2 by inhibiting the mRNA and the protein expression of mPGES-1 in gingival fibroblasts. This finding may partly explain the anti-inflammatory effect of the agent previously reported in clinical studies.     

Arachidonic acid inhibits osteoblast differentiation through cytosolic phospholipase A2-dependent pathway

OBJECTIVE: Arachidonic acid, a precursor of prostaglandins (PGs), is released by phospholipase A2 (PLA2) and plays an important role in biological reactions. We examined the roles of arachidonic acid on the pathway of PG synthesis and osteoblast differentiation by using clone MC3T3-E1 cells. MATERIALS AND METHODS: The effect of arachidonic acid was evaluated by the measurement of alkaline phosphatase activity, cells shape, production of arachidonic acid and the expression of cyclooxygenase (COX). RESULTS: Arachidonic acid dose dependently decreased alkaline phosphatase activity and increased PGE2 production in MC3T3-E1 cells. The cell shape changed from polygonal to fibroblastic following treatment with arachidonic acid. These effects were recovered by the treatment of NS-398 and indomethacin. Arachidonic acid increased the expression of COX-2 mRNA and the PGE2 production. The exogenous arachidonic acid induced the release of cellular arachidonic acid in MC3T3-E1 cells. Moreover, methylarachidonyl fluorophosphonate suppressed the arachidonic acid release and the expression of COX-2 mRNA. CONCLUSION: The present results indicate that exogenous arachidonic acid stimulated the activity of PLA2, leading to the new release of membranous arachidonic acid. The amplified arachidonic acid enhanced PGE2 production by COX-2, which inhibits the differentiation of MC3T3-E1 cells. Our results provide a new insight into the molecular mechanisms by which exogenous arachidonic acid plays a role as a paracrine/autocrine amplifier of PGE2 biosynthesis by coupling with PLA2 and COX-2.