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.     

绿茶多酚对牙龈上皮细胞内炎症因子的抑制作用

目的:探讨绿茶多酚表没食子儿茶素没食子酸酯(epigallocatechin gallate,EGCg)对牙龈上皮细胞炎症反应的作用,从而为牙周病的预防和治疗开发安全有效的牙周炎症抑制剂提供依据。方法:通过建立牙龈卟啉单胞菌膜泡刺激牙龈上皮细胞引起细胞炎症反应的体外模型,以酶联免疫吸附法(ELISA)检测EGCg对牙龈上皮细胞分泌前列腺素E2(PGE2)的影响,以Real-time RT-PCR法检测EGCg对牙龈上皮细胞表达环氧化物酶-2(COX-2)和基质金属蛋白酶-3(MMP-3)mRNA的作用。结果:EGCg浓度依赖性抑制牙龈上皮细胞内PGE2分泌和COX-2、MMP-3 mRNA的表达水平。结论:EGCg对牙龈上皮细胞的炎症反应具有抑制作用,具有成为牙周炎症抑制剂的潜能。     

牙龈卟啉单胞菌感染对类风湿关节炎作用的研究

目的利用牙周炎与类风湿关节炎小鼠模型研究牙龈卟啉单胞菌感染对类风湿关节炎的影响。方法实验小鼠被分为单纯类风湿关节炎组与牙周炎合并类风湿关节炎组。实验中通过口腔涂抹牙龈卟啉单胞菌构建牙周炎模型,利用牛Ⅱ型胶原诱导小鼠类风湿关节炎模型的建立。通过比较牙龈卟啉单胞菌感染与否对类风湿关节炎严重程度的影响来探讨牙龈卟啉单胞菌感染是否会促进类风湿关节炎的发生及发展。实验中通过类风湿关节炎评分评估类风湿关节炎的严重程度;利用酶联免疫分析试剂盒检测血浆中类风湿关节炎相关因子的水平。结果牙龈卟啉单胞菌感染合并胶原诱导类风湿关节炎组的类风湿关节炎症状出现时间较单纯胶原诱导类风湿关节炎组明显缩短,并且在牙龈卟啉单胞菌感染情况下的类风湿关节炎的症状及类风湿关节炎相关炎症因子如TNF-α、IL-1、IL-6、IL-17的水平也明显升高。结论牙龈卟啉单胞菌感染能促进类风湿关节炎的发生并加重类风湿关节炎症状。     

牙周组织病

盐酸米诺环素微球凝胶的制备及对大鼠实验性牙龈炎的抑制作用；云南白药对比格犬牙龈炎的治疗作用；细胞凋亡相关基因Bcl-2和Bax在大鼠牙周膜改建中的作用；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；派丽奥软膏辅助治疗慢性牙周炎的疗效观察     

牙龈卟啉单胞菌侵入牙龈上皮细胞的分子机制

牙龈卟啉单胞菌是慢性牙周炎的主要致病菌，牙龈上皮细胞是宿主牙周组织防御机制的第一道天然屏障。牙龈卟啉单胞菌可通过特异性粘附素与牙龈上皮细胞相应配体结合，激活该细胞内多种信号传导途径，最终内化于牙龈上皮细胞。内化后可通过某些细胞因子的合成和分泌减少以及抑制细胞凋亡等机制造成该细胞功能紊乱。本文从分子水平对牙龈卟啉单胞菌侵入牙龈上皮细胞的机制作一综述，以进一步阐明牙龈卟啉单胞菌的致病机理。     

牙龈卟啉单胞菌侵入牙龈上皮细胞的分子机制

牙龈卟啉单胞菌是慢性牙周炎的主要致病菌,牙龈上皮细胞是宿主牙周组织防御机制的第一道天然屏障。牙龈卟啉单胞菌可通过特异性粘附素与牙龈上皮细胞相应配体结合,激活该细胞内多种信号传导途径,最终内化于牙龈上皮细胞。内化后可通过某些细胞因子的合成和分泌减少以及抑制细胞凋亡等机制造成该细胞功能紊乱。本文从分子水平对牙龈卟啉单胞菌侵入牙龈上皮细胞的机制作一综述,以进一步阐明牙龈卟啉单胞菌的致病机理。     

不同rag基因型牙龈卟啉单胞菌在慢性牙周炎患者中的分布

目的分析不同rag基因型牙龈卟啉单胞菌在慢性牙周炎患者中的分布状况。方法收集50例慢性牙周炎患者的150个龈下菌斑样本,采用16S rDNA 聚合酶链反应（PCR）法检测牙龈卟啉单胞菌在牙周炎病变位点的检出率,并根据各rag基因型的特异性引物检测牙龈卟啉单胞菌不同rag基因型在慢性牙周炎病变位点的分布。结果经16S rDNA PCR法检测,病变位点牙龈卟啉单胞菌阳性检出率为70.7%。各rag基因型在牙龈卟啉单胞菌阳性位点的总检出率：rag-1为60.4%,rag-2为23.6%,rag-3为44.3%,rag-4为15.1%;经统计学检验,rag-1和rag-3型检出率较高,高于rag-2和rag-4型（P<0.05）。结论慢性牙周炎患者龈下菌斑中的牙龈卟啉单胞菌存在rag基因多态性,rag-1和rag-3基因型牙龈卟啉单胞菌与中国辽宁地区人群慢性牙周炎的发生发展关系密切。     

丹皮酚对牙龈卟啉单胞菌诱导骨髓来源巨噬细胞功能的影响

目的 观察丹皮酚对牙龈卟啉单胞菌作用下对体外培养的小鼠骨髓来源巨噬细胞（BMM）炎性因子分泌及向破骨细胞分化能力的影响,并探讨其作用机制。方法 体外分离获得小鼠生长良好的BMM,加入不同浓度丹皮酚溶液处理1 h,再加入牙龈卟啉单胞菌进行24 h诱导刺激。采用流式细胞术检测炎症相关蛋白程序性死亡分子配体1（PD-L1）的表达量,采用酶联免疫吸附试验（ELISA）检测细胞上清液中肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）及白细胞介素-6（IL-6）水平;在核因子κB受体活化因子配体（RANKL）和巨噬细胞集落刺激因子（M-CSF）刺激后的BMM中加入不同浓度的丹皮酚溶液处理1 h后,加入牙龈卟啉单胞菌刺激,采用抗酒石酸性磷酸酶（TRAP）染色观察破骨细胞形成情况,Western blot检测破骨细胞形成相关蛋白TRAP和核因子κB受体活化因子（RANK）的表达。结果 丹皮酚在10~50 μmol·L^-1的范围内,对BMM无毒性作用。流式细胞术结果提示丹皮酚可以抑制牙龈卟啉单胞菌诱导PD-L1的表达,并存在剂量依赖效应。ELISA实验证明丹皮酚能以剂量依赖性方式抑制BMM释放TNF-α、IL-1β及IL-6（P<0.01）。牙龈卟啉单胞菌可以明显诱导BMM分化形成破骨细胞;TRAP染色显示丹皮酚各浓度组能抑制BMM向破骨细胞分化;Western blot结果显示丹皮酚抑制TRAP和RANK表达且存在剂量依赖效应。结论 丹皮酚可以剂量依赖方式抑制牙龈卟啉单胞菌诱导的BMM炎性因子TNF-α、IL-1β及IL-6的分泌及其向破骨细胞分化的能力。     

维吾尔族慢性牙周炎中牙龈卟啉单胞菌菌fimA毒力基因型的分布

目的：分析维吾尔族慢性牙周炎患者龈下菌斑中牙龈卟啉单胞菌菌毛fimA毒力基因型的分布情况。方法：收集52例维吾尔族慢性牙周炎患者的龈下菌斑，采用16SrRNA PCR法检测牙龈卟啉单胞菌，并根据菌毛fima毒力基因型的特异引物，用聚合酶链反应（PCR）检测Ⅱ型fimA和Ⅳ型fima菌株的分布。结果：16SrRNA PCR法检测牙龈卟啉单胞菌在龈下菌斑中阳性检出率是76．9％。牙周袋PPD〉6mm位点龈下菌斑标本的P．gingivalis检出率高于4〈PPD≤6mm采样的位点，2组差异有统计学意义（P〈0．05）。牙龈卟啉单胞菌菌毛．fimA毒力基因型在牙龈卟啉单胞菌感染者的检出率分别是：Ⅱ fimA型为37．5％，ⅣfimA型为22．5％。结论：维吾尔族慢性牙周炎患者龈下菌斑中牙龈卟啉单胞菌有较高的检出率。牙龈卟啉单胞菌存在fima毒力基因多态性。     

正畸患者牙龈卟啉单胞菌基因检测

目的 对正畸患者口腔中牙龈卟啉单胞菌等牙周致病菌进行检测。方法 选择１６例固定正畸患者发生牙周炎症的牙周袋和牙周健康的龄袋为取菌斑样本占。分成牙周炎症组和对照组。根据改良聚合酶链反应检测技术，直接检测临床标本中牙龈卟啉单力的ＦｉｍＡ基因，并做此检测技术的敏感性和特异性实验。结果 牙周炎组牙龈卟啉单胞菌的检测阳性率（５６．３５）显著大于对照组（１８．８％），Ｐ〈０．０５。检测技术的敏感性和特异性较高     

Cyclooxygenase-2-dependent prostaglandin production by peripheral blood monocytes stimulated with lipopolysaccharides isolated from periodontopathogenic bacteria

BACKGROUND: Prostaglandin E2 (PGE2) plays important roles in the pathogenesis of periodontal disease. Recent studies have revealed the existence of 2 isozymes of cyclooxygenase (COX), called COX-1 and COX-2. The purpose of the present study was to investigate the contribution of COX-1 and COX-2 to PGE2 production by human peripheral blood monocytes that are stimulated with lipopolysaccharides (LPS) from periodontopathogenic bacteria. METHODS: LPS were isolated from Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans) and Porphyromonas gingivalis (P. gingivalis) by the phenol-water method. Peripheral blood monocytes were stimulated with LPS for the indicated periods, and the levels of PGE2 or interleukin (IL)-1 beta in the culture media were measured by enzyme-linked immunosorbent assay. Expression of COX-1 and -2 proteins was studied by immunocytochemical staining, and COX-2 mRNA expression was examined by Northern blot analysis. RESULTS: Peripheral blood monocytes stimulated with A. actinomycetemcomitans- or P. gingivalis-LPS produced PGE2 in a time- and dose-dependent manner. Indomethacin, a non-selective COX-1/COX-2 inhibitor, and NS-398, a specific COX-2 inhibitor, completely inhibited PGE2 production. Immunocytochemical staining of COX-1 and COX-2 proteins showed that expression of COX-2 protein was increased in monocytes that were stimulated with A. actinomycetemcomitans- or P. gingivalis-LPS, compared with that in unstimulated monocytes, whereas expression of COX-1 protein was not altered. Northern blot analysis showed that monocytes stimulated with A. actinomycetemcomitans- or P. gingivalis-LPS expressed COX-2 mRNA, while COX-2 mRNA was not detectable in unstimulated cells. Treatment of A. actinomycetemcomitans-LPS-stimulated monocytes with NS-398 induced a significant increase of IL-1 beta production to the same extent as treatment with indomethacin. CONCLUSIONS: These results suggest that COX-2 is induced in monocytes stimulated with LPS derived from A. actinomycetemcomitans and P. gingivalis and that the COX-2 is primarily responsible for PGE2 production. COX-2 may be pivotal in PGE2 production in periodontal lesions and may be involved in inflammatory responses.     

Cyclooxygenase-2 inhibitors decrease interleukin-1beta-stimulated prostaglandin E2 and IL-6 production by human gingival fibroblasts

BACKGROUND: Previous work showed that normal and aggressive periodontitis (AgP) gingival fibroblasts produce the bone-resorbing cytokine IL-6. PGE2 is important in regulating IL-6 production. Non-steroidal anti-inflammatory drugs inhibit PG synthesis via COX-1 and/or COX-2 isoenzymes and may inhibit periodontal destruction. COX-2 is induced after cellular activation (i.e., by inflammatory cytokines such as IL-1beta). Little is known about IL-1beta-stimulated AgP fibroblast IL-6 and PGE2 production and their regulation by COX inhibitors. The objective of this study was to determine the effects of COX-2 inhibitors on amounts of PGE2 and IL-6 made by IL-1beta-stimulated gingival fibroblasts. METHODS: Gingival fibroblasts (2.5 x 10(4)) from healthy or severe periodontitis patients were cultured in serum-free medium, with or without IL-1beta (10(-11)M) for 24 hours, with or without the COX-1/2 inhibitor indomethacin or the selective COX-2 inhibitors NS-398, celecoxib, or rofecoxib. PGE2 and IL-6 in culture supernatants were determined by specific enzyme-linked immunosorbent assay (ELISA)s. RESULTS: All of the COX inhibitors caused dose-dependent decreases in IL-1beta-stimulated PGE2, to a maximum of > 90% in all cell lines (P < or = 0.0001). The selective COX-2 inhibitors, but not indomethacin, caused partial (generally up to approximately 60%), dose-dependent decreases in IL-1beta-stimulated IL-6 in all cell lines (P < or = 0.003). When exogenous PGE2 was added concurrently with COX-2 inhibitors before addition of IL-1beta, IL-6 production returned to levels at or approaching that produced by cells exposed only to IL-1beta (P < or = 0.04). CONCLUSION: The results suggest that COX-2 inhibition may be useful in helping to control fibroblast production of IL-6 in patients with severe periodontitis.     

The host cytokine response to Porphyromonas gingivalis is modified by gingipains

Background/aims:  Clinical studies indicate that primary proinflammatory cytokines, such as interleukin-1β (IL-1β) are elevated in the gingival crevice around teeth with periodontitis but the secondary cytokines and chemokines, IL-6 and IL-8, are not. The human gingival epithelial cells (HGECs) lining the gingival sulcus respond to perturbation by microbes of dental plaque by releasing a wide range of cytokines. Porphyromonas gingivalis , a putative periodontal pathogen, possesses numerous virulence factors some of which directly impact on the host response. In the present study, we sought to determine how P. gingivalis influences the inflammatory cytokine responses.
Methods:  HGECs were challenged with P. gingivalis and other putative periodontal pathogens, and the resultant production of IL-1β, IL-6, and IL-8 was assayed by enzyme-linked immunosorbent assay (ELISA). Culture supernatants and recombinant human cytokines were challenged with live P. gingivalis wild-type and gingipain-deficient strains and the resultant cytokine profile was assessed by ELISA and Western blot.
Results:  We show here that primary HGECs challenged with live P. gingivalis result in high levels of IL-1β but not the related secondary cytokines IL-6 and IL-8. We further demonstrate that cytokine response differences are the result of the action of P. gingivalis proteases, with lysine gingipain being the most effective.
Conclusion:  We conclude that P. gingivalis , through lysine gingipain, can subvert the protective host proinflammatory response by direct cytokine degradation. Changes in the crevicular cytokine profile have consequences in periodontal disease pathogenesis that should be considered in the development of diagnostic and therapeutic modalities.     

Involvement of cyclooxygenase-2 in interleukin-1alpha-induced prostaglandin production by human periodontal ligament cells.

BACKGROUND: Human periodontal ligament (PDL) cells produce prostaglandin (PG) E2 in response to proinflammatory cytokines. However, the mechanism of PGE2 production is not well understood. The purpose of the present study was to investigate the involvement of cyclooxygenase (COX)-1 and COX-2 in PGE2 production by PDL cells stimulated with a proinflammatory cytokine, interleukin-1alpha (IL-1alpha), and to examine the regulation of PGE2 production by cell-cell interaction of human gingival keratinocytes and PDL cells. METHODS: The levels of PGE2 in the culture media of PDL cells stimulated with IL-1alpha or culture media of human gingival keratinocytes were determined by an enzyme-linked immunosorbent assay. Expression of COX-1 and -2 mRNA and protein was studied by Northern blot analysis and Western blot analysis, respectively. RESULTS: IL-1alpha-stimulated PDL cells produced PGE2 in a time-dependent manner. Indomethacin, a non-selective COX-1/COX-2 inhibitor, and NS-398, a selective COX-2 inhibitor, completely inhibited PGE2 production by the IL-1alpha-stimulated cells. COX-2 mRNA was detected after IL-1alpha stimulation, although it was not detected in unstimulated cells. There was no difference in expression of COX-1 mRNA between unstimulated cells and IL-la-stimulated cells. Expression of COX-2 protein in IL-1alpha-stimulated cells was increased, compared with that in unstimulated cells, whereas COX-1 protein expression was almost the same in both the cells. Treatment of IL-1alpha-stimulated PDL cells with dexamethasone, known to inhibit COX-2 expression, prevented PGE2 production and COX-2 mRNA expression. Addition of the culture media of human gingival keratinocytes to PDL cells increased PGE2 production. The PGE2 production was depressed by treatment of the cells with IL-1 receptor antagonist and anti- IL-1alpha antibody, not with anti-IL-1beta antibody. The PGE2 production was also inhibited by treatment with NS-398 and dexamethasone. CONCLUSIONS: We suggest that PDL cells stimulated with IL-1alpha produce PGE2 through de novo synthesis of COX-2 and that the cell interaction of gingival keratinocytes and PDL cells controls COX-2 expression and PGE2 production via IL-1alpha or 1alpha IL-la-like factor(s). Selective COX-2 inhibitors, which have the advantage of reduced gastric toxicity, may provide a useful approach to treatment of periodontal disease.