TLR-2和TLR-4与牙周病发生发展的相互关系

牙周炎是一种以细菌为主要病因的慢性感染性疾病，牙龈卟啉菌被认为是引起牙周炎的最重要细菌之一。近年来在研究牙龈卟啉菌与牙周炎的关系中发现，Toll样受体在牙周炎的免疫过程起着重要作用。本文对近年来对Toll样受体与牙龈卟啉菌在牙周炎中的研究进展作一综述。     

不同牙周状况龈下菌斑中牙龈卟啉单胞菌和福赛斯坦纳菌的分布

目的 分析中国牙周健康者和慢性牙周炎患者龈下菌斑中牙龈卟啉单胞菌和福赛斯坦纳菌的分布情况,探讨两种细菌在中国慢性牙周炎患者中的分布及其致病机理.方法 收集65例牙周健康者、62例慢性牙周炎患者的龈下菌斑,采用16S rRNA PCR方法检测牙龈卟啉单胞菌和福赛斯坦纳菌的分布.结果 牙周健康者牙龈卟啉单胞菌和福赛斯坦纳菌的检出率分别是21.6%、12.3%,慢性牙周炎患者病变位点两菌检出率分别为74.2%、58.1%,牙周炎健康位点两菌的检出率分别是22.6%、4.8%.牙周炎病变位点两种细菌的检出率均明显高于牙周健康者和牙周炎健康位点(P＜0.001);福赛斯坦纳菌在牙周健康者中的检出率高于牙周炎健康位点(P＜0.05);牙周健康者和牙周炎健康位点牙龈卟啉单胞菌的检出率没有差异.慢性牙周炎患者两菌联合检出率为51.6%.结论 牙龈卟啉单胞菌、福赛斯坦纳菌以及两种细菌联合感染与牙周炎密切相关.     

牙龈蛋白酶及其致病作用

牙龈卟啉单胞菌是引起和加重牙周炎的重要致病菌,其分泌的牙龈蛋白酶是其主要的毒力因子之一。本文就牙龈卟啉单胞菌牙龈蛋白酶以及牙龈蛋白酶对细菌生长和黏附的影响、对组织的破坏作用、对宿主防御机制的作用等研究进展作一综述。     

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.     

慢性牙周炎患者牙周袋内硫化物水平与厌氧细菌分布的相关性研究

目的:探讨慢性牙周炎患者牙周袋内硫化物水平(sulfide levels in periodontal pockets,SUL)与牙龈卟啉单胞菌、中间普氏菌、伴放线放线杆菌分布的相关性.方法:用perio2000 system金刚探针牙周诊断仪测定慢性牙周炎患者SUL,采用PCR方法检测龈下菌斑中牙龈卟啉单胞菌、中间普氏菌和伴放线放线杆菌.结果:慢性牙周炎患者随着牙周袋内SUL浓度的增加牙龈卟啉单胞菌、中间普氏菌的检出率逐渐增加,相关系数分别为0.812和0.651(P<0.05);SUL阳性位点与阴性位点中牙龈卟啉单胞菌的检出率分别是为85.6%、26.7%,中间普氏菌的检出率分别为95.2%、53.3%.SUL阳性位点中牙龈卟啉单胞菌和中间普氏菌的检出率明显高于SUL阴性位点;在80.9%的SUL阳性位点中牙龈卟啉单胞菌与中间普氏菌共存.SUL阳性位点与阴性位点均未检出伴放线放线杆菌.结论:慢性牙周炎患者SUL与牙龈卟啉单胞菌和中间普氏菌分布关系较为密切.     

牙龈卟啉菌、中间普氏菌的分离、培养和鉴定

目的：采用厌氧培养和鉴定技术，分离牙周炎患者龈下菌斑中的牙龈卟啉菌和中间普氏菌。方法：采集牙周炎患者的龈下菌斑，厌氧培养，分离产黑色素菌。经长波长紫外灯观察，各种生化分析和间接免疫荧光染色，分离和鉴定牙龈卟啉菌，中间普氏菌。结果：在受检的33例牙周炎患者中，24例患者检出了牙龈卟啉菌，总检出率为72．77％，共分离了79株。18例患者检出了中间普氏菌，总检出率为54．54％。共分离了32株。结论：厌氧培养，生化反应鉴定技术的发展，使牙龈卟啉菌和中间普氏菌的分离与培养准确可靠，为今后在分子水平上了解各菌株的致病机理打下了基础。     

应用实时荧光定量PCR定量检测慢性牙周炎患者龈下菌斑中牙龈卟啉单胞菌

目的 检测慢性牙周交患者和牙周健康人龈下菌斑中牙龈卟啉单胞菌、总菌量和牙龈卟啉单胞菌所占比例,探讨牙龈卟啉单胞菌与牙周炎发生发展的关系.方法 采集经常规PCR方法检测牙龈卟啉单胞菌为阳性的76例慢性牙周炎患者和25例牙周健康者的龈下菌斑,应用TaqMan实时荧光定量PCR方法定量检测样本中牙龈卟啉单胞菌、总菌量;构建含有牙龈卟啉单胞菌和真细菌扩增片断的重组质粒,建立定量标准.结果 本研究设计的引物和探针具有良好的特异性及敏感性.病变位点龈下菌斑中牙龈卟啉单胞菌数量和总菌量均比健康位点高(P<0.001),两组位点牙龈卟啉单胞菌在菌斑中的比例没有差异(P>0.05);细菌数量与探诊深度间存在显著正相关关系(P<0.001),不同的探诊深度牙龈卟啉单胞菌所占比例无统计学差异(P>0.05).结论 龈下菌斑中牙龈卟啉单胞菌的数量水平及细菌总量与牙周状况、牙周炎发展有密切关系,实时荧光定量PCR对牙周病学研究具有广泛的应用前景.     

牙龈卟啉单胞菌的研究进展

牙龈卟啉单胞菌( Porphyromonas gingivalis,P. gingivalis)是牙周感染最重要的致病菌,与慢性牙周炎的发生发展密切相关。其致病性归因于一系列毒力因子如菌毛、荚膜、脂多糖、牙龈蛋白酶等。相关毒力因子的致病机制引起了国内外学者的广泛关注和重视。本文就牙龈卟啉单胞菌表面结构菌毛、荚膜及菌体分泌脂多糖、牙龈蛋白酶等重要致病因子的致病机制研究进展做一综述,以期为牙周炎的防治提供新的靶点和思路。     

慢性牙周炎龈下菌斑中五种牙周可疑致病微生物的分布

目的研究五种牙周可疑致病微生物在慢性牙周炎患者龈下菌斑的分布。方法选择27例慢性牙周炎患者,每位患者选取牙周袋最深的两个位点作为观察位点,采集龈下微生物样本,采用多重聚合酶链反应和反杂交的方法对伴放线菌嗜血菌、牙龈卟啉单胞菌、福赛斯坦纳菌、中间普雷沃菌和齿垢密螺旋体五种微生物进行半定量检测。结果在所检测的54个位点中,牙龈卟啉单胞菌、中间普雷沃菌、福赛斯坦纳菌和齿垢密螺旋体均有较高的检出率,分别为98.15%、92.59%、100%和98.15%;伴放线菌嗜血菌检出率较低,为20.37%。牙龈卟啉单胞菌和福赛斯坦纳菌的检出量明显高于其他三种微生物,其差异有统计学意义（P<0.05）。结论慢性牙周炎患者多存在牙龈卟啉单胞菌、福赛斯坦纳菌、中间普雷沃菌和齿垢密螺旋体的同时感染,且牙龈卟啉单胞菌和福赛斯坦纳菌的感染量较高。     

牙龈蛋白酶R和蛋白酶激活受体在牙周炎中的作用

牙龈卟啉单胞菌是公认的牙周重要的致病菌,其分泌的牙龈蛋白酶R是其主要的毒力因子之一。蛋白酶激活受体是一种可识别多种分子的跨膜蛋白,牙龈蛋白酶R通过激活该受体在牙周炎的发生发展过程中发挥着重要的作用。本文就牙龈蛋白酶R和蛋白酶激活受体组成和生物学特性,牙龈蛋白酶R对蛋白酶激活受体的激活作用等研究进展作一综述。     

Ovine periodontitis as a potential model for periodontal studies. Cross-sectional analysis of clinical,microbiological, and serum immunological parameters

OBJECTIVES: : To investigate infection and host immunity patterns in sheep with naturally occurring "broken-mouth" periodontitis. MATERIALS AND METHODS: : Eight periodontally healthy (HS) and eight periodontally diseased ewes (PDS) were selected. Subgingival plaque and sera were collected and examined for evidence of human periodontitis-associated pathogens. Serum IgG titers were measured by ELISA to multiple strains of Porphyromonas gingivalis, Bacteroides forsythus, Dichelobacter nodosus, Actinobacillus actinomycetemcomitans, Prevotella intermedia, and Fusobacterium nucleatum as well as several purified antigens (cysteine proteases, LPS, K, and fimbriae). RESULTS: : Neither the organism Aa nor antigens to Aa were found in any animal. Most animals were positive for Pg, Bf, and Pi, but DNA probes detected no difference between HS and PDS relative to amounts of pathogens in subgingival plaque. PDS had significantly higher serum IgG titers to all Pg strains, to 50% of Bf strains, to the Pi and Fn strains, and to fimbriae and the two cysteine proteases (p-values ranging from 0.05 to 0.001). Regression analysis demonstrated a significant association between number of teeth lost and serum IgG antibody titers to whole-cell sonicate antigens of P. gingivalis strains (p<0.01) and body weight (p<0.01). CONCLUSIONS: : The presence of pathogens associated with periodontitis was reflected in differences in serum IgG titers between healthy and diseased sheep. This may have influenced animal body weight and might have systemic health and economic consequences. The data suggest that susceptible and non-susceptible sheep can be identified for periodontal research.     

Influence of resin coating materials on Porphyromonas gingivalis attachment

Resin coating materials have been used for composite resin or provisional restoration in order to prevent plaque accumulation on their surfaces. However, it is not clear whether the coating materials influence attachment of periodontal bacteria. Therefore, we investigated the effect of resin coating materials on the attachment of Porphyromonas gingivalis (Pg). The polymerized auto cure resin plates were coated with two resin coating materials. To estimate the Pg attachment, each plate was immersed in brain heart infusion medium containing Pg. The quantity of bacteria attached on each plate was evaluated by crystal violet quantification. Morphological change of Pg was recorded using scanning electron microscopy. Both coating groups presented significantly lower Pg attachment compared to the control. The Pg shapes on the plates with resin coating materials were similar to the non-treated control plates. The resin coating materials clearly prevent Pg attachment on the polymerized auto cure resin plate.     

Porphyromonas gingivalis virulence factors and invasion of cells of the cardiovascular system

Our laboratory is interested in the genes and gene products involved in the interactions between Porphyromonas gingivalis (Pg) and the host. These interactions may occur in either the periodontal tissues or other non-oral host tissues such as those of the cardiovascular system. We have previously reported the cloning of several genes encoding hemagglutinins, surface proteins that interact with the host tissues, and are investigating their roles in the disease process. Primary among these is HagA, a very large protein with multiple functional groups that have significant sequence homology to protease genes of this species. Preliminary evidence indicates that an avirulent Salmonella typhimurium strain containing hagA is virulent in mice. These data indicate that HagA may be a key virulence factor of Pg. Additionally, we are investigating the invasion of primary human coronary artery endothelial cells (HCAEC) by Pg because of the recent epidemiological studies indicating a correlation between periodontal disease (PD) and coronary heart disease (CHD). We found that some, but not all, strains of Pg are able to invade these cells. Scanning electron microsopy of the infected HCAEC demonstrated that the invading organisms initially attached to the host cell surface as aggregates and by a "pedestal"-like structure. By transmission electronmicroscopy it could be seen that internalized bacteria were present within multimembranous compartments localized with rough endoplasmic reticulum. In addition, invasion of the HCAEC by Pg resulted in an increase in the degradation of long-lived cellular proteins. These data indicate that Pg are present within autophagosomes and may use components of the autophagic pathway as a means to survive intracellularly. However, Pg presence within autophagosomes in KB cells could not be observed or detected. It is therefore likely that Pg uses different invasive mechanisms for different host cells. This and the role of HagA in invasion is currently being investigated further.     

Relationship of periodontal bacteria and Porphyromonas gingivalis fimA variations with phenytoin-induced gingival overgrowth

OBJECTIVES: We investigated the relationship between phenytoin-induced gingival overgrowth (GO) and the harboring of periodontal bacteria. MATERIALS AND METHODS: Periodontal conditions and subgingival bacterial profiles were examined in 450 sites of 75 subjects. A polymerase chain reaction method was used to detect six bacterial species; Porphyromonas gingivalis (Pg), Actinobacillus actinomycetemcomitans (Aa), Tannerella forsythia, Treponema denticola (Td), Prevotella intermedia (Pi), and Prevotella nigrescens (Pn). Genetic variations of the Pg fimA gene were also examined. Bacterial occurrence was compared with the severity of GO, and alterations in the bacterial occurrence rate and quantities were monitored following periodontal treatment. RESULTS: The occurrences of Aa, Td, Pi, Pn, and Pg with type II fimA (type II Pg) were significantly associated with the severity of GO. Td occurrence was reduced in association with gingival improvement following ultrasonic scaling, however, no such relationship was observed with Aa, Pi, Pn, and Pg. In addition, Pg and Pi markedly persisted after treatment. Clinical improvement of the sites, following an Er:YAG laser treatment, significantly associated with quantitative reduction of Pg in improved sites, however, not that of Pi. CONCLUSION: Type II Pg and Td were each found to have a significant relationship with the development and deterioration of GO.     

慢性牙周炎唾液牙龈卟啉单胞菌的定量PCR检测

目的:定量检测慢性牙周炎患者、牙周健康人群唾液中牙龈卟啉单胞菌的含量,比较其在各组人群分布的差异。方法:应用SYBR Green模式的实时荧光定量PCR技术,针对Pg特异基因Arg-gingipain设计引物,检测20例慢性牙周炎和20例牙周健康者唾液内Pg的含量,t检验分析比较在各组人群中Pg定植的差异。结果:慢性牙周炎患者唾液中,Pg的检出数目为(1.78×10³~1.99×10⁵),检出率为85%;牙周健康者唾液中,Pg的检出数目为(2.19×10³~2.30×10³),检出率为10%。Pg在慢性牙周炎和牙周健康者唾液中检出数目和检出率的差异具有统计学意义(P<0.05)。结论:慢性牙周炎唾液中,牙龈卟啉单胞菌较正常人群明显升高,在今后的研究及防治中,不仅要观察龈沟液中的牙龈卟啉单胞菌,也应注意其在唾液中含量的变化。     

牙髓源性牙周牙髓联合病变牙周袋内牙龈卟啉单胞菌定量PCR检测

目的 比较牙髓源性牙周牙髓联合病变与重度慢性牙周炎患牙牙周袋内牙龈卟啉单胞菌的数量差异,为临床诊断牙髓源性牙周牙髓联合病变提供科学依据.方法 采集牙髓源性牙周牙髓联合病变、重度慢性牙周炎牙周袋内的龈下菌斑及正常人群龈沟液标本,应用实时定量PCR法检测牙龈卟啉单胞菌(Porphyromonas gingivalis,Pg)数量.结果 3组标本中Pg检出率差异无统计学意义;Pg数量差异有统计学意义.牙髓源性牙周牙髓联合病变中Pg数量显著性低于重度慢性牙周炎患牙(P<0.01),与正常人群Pg数量差异无统计学意义.结论 牙髓源性牙周牙髓联合病变中Pg数量低于重度慢性牙周炎患牙,与正常人龈沟液内的水平一致,Pg数量有可能作为鉴别牙髓源性与牙周源性牙周牙髓联合病变的指标.     

牙龈卟啉单胞菌对人脐静脉内皮细胞一氧化氮生成的影响

目的 观察牙龈卟啉单胞茵(Porphyromonas gingivalis,Pg)对人脐静脉内皮细胞皮细胞功能损伤的途径,以期为牙周病在动脉粥样硬化发病机制中的作用提供依据.方法 应用厌氧罐培养Pg ATCC33277,用感染复数(multiplicity of infection,MOI)1:10、1:100、1:1000的Pg干预HUVEC,未受Pg干预的HUVEC作为阴性对照组,分别于4、8、12、24 h时收集细胞上清液,利用硝酸还原酶法测定细胞上清液中NO的浓度.结果 在24 h内,Pg MOI 1:10、1:100均能促进HUVEC NO的生成,与阴性对照组相比差异有统计学意义(P＜0.05);Pg MOI 1:1000干预HUVEC后,12 h内可促进HUVEC NO的生成,但与阴性对照组相比差异无统计学意义,24 h时HUVEC NO的生成降低[(57.83±9.09)mmol/L],与其他各组相比差异均有统计学意义(P＜0.05).结论 Pg对内皮细胞NO的生成有影响.Pg MOI 1:10、1:100能够促进内皮细胞NO的生成,Pg MOI 1:1000则抑制内皮细胞NO的生成.     

牙龈卟啉单胞菌感染血管平滑肌细胞的超微结构观察

目的:观察牙龈卟啉单胞菌(Porphyromonas gingivalis,Pg)对大鼠胸大动脉平滑肌细胞黏附及入侵情况,探讨Pg对血管平滑肌细胞的损伤途径,为牙周病在动脉粥样硬化发病机制中的研究提供依据.方法:用感染复数(multiplicity of infection,MOD为100∶1 Pg感染大鼠胸大动脉平滑肌细胞,分别于8、16 h TEM观察Pg对血管平滑肌细胞的黏附和入侵能力.结果:Pg感染大鼠胸大动脉平滑肌细胞16h时,Pg能利用表面菌毛黏附于血管平滑肌细胞表面并入侵胞质内.结论:Pg能够黏附于大鼠胸大动脉平滑肌细胞,并入侵细胞质,定植于细胞内.     

Porphyromonas gingivalis fimbriae induce unique dendritic cell subsets via Toll-like receptor 2

Backgound and Objective:  Dendritic cells (DCs) play a critical role in the activation of T cells as well as in shaping immune responses. We have reported previously that Porphyromonas gingivalis lipopolysaccharides ( Pg LPS) induced a CD14⁺CD16⁺ DC subset with a weak immuno-stimulatory activity. In contrast, Escherichia coli LPS ( Ec LPS) induced fully matured DCs with strong immunostimulatory activities. Since Pg LPS as well as Pg fimbriae have been indicated to work as Toll-like receptor (TLR) 2 ligands, we speculate that the TLR usage of bacterial antigens may be critical for DC maturation.
Material and Methods:  We investigated the effect of Pg fimbriae on the phenotype and function of human peripheral blood DCs in comparison with a TLR2 ligand, peptidoglycan, and a TLR4 ligand, Ec LPS.
Results:  Flow cytometry revealed that Pg fimbriae and peptidoglycan but not Ec LPS induced CD14 and CD16 expression on peripheral blood DCs (CD14⁻CD16⁻). A monoclonal antibody against TLR2 abrogated this induction, but an antibody against TLR4 had no effect. Dendritic cells stimulated with Pg fimbriae had a weaker capability to induce allogenic T cell proliferation and exhibited a weaker production of interleukin-8 and regulated upon activation, normal T cell expressed and secreted (RANTES) than DCs stimulated with Ec LPS.
Conclusion:  These results indicate that different TLR usage affects mature DC phenotype and function and is thus crucial to the regulation of immunity to the pathogen.     

Effects of experimental periodontitis on the metabolic system in rats with diet-induced obesity (DIO): an analysis of serum biochemical parameters

Recent studies have shown that periodontitis accelerates the progression of obesity-associated metabolic diseases. Thus, we examined the influence of periodontitis on serum biochemical parameters of metabolic disease in a diet-induced obesity (DIO) rat. First, we established the DIO model using ten male rats fed with either basal diet (lean group) or high-fat diet (DIO group) for 12 weeks. Second, to examine the interaction between periodontitis and obesity, we divided 24 DIO rats into the following four groups. (1) Porphyromonas gingivalis (Pg) group was applied with Pg around the maxillary first molar (M1). (2) Ligature group was applied with ligature placement around M1. (3) Ligature/Pg group was treated with both ligature placement and Pg. (4) Control was non-treatment group. Serum biochemical parameters and maxillary histopathology were evaluated at 12 weeks. The DIO model demonstrated significant increases in body weight, serum insulin, alanine aminotransaminase (ALT) levels, and insulin resistance (HOMA-IR) compared to the lean group. In the DIO ligature and ligature/Pg groups, alveolar bone resorption and inflammatory cell infiltration were significantly increased compared to the control. Serum levels of fasting glucose, lactate dehydrogenase, and uric acid were also significantly higher, while the liver damage markers ALT and aspartate aminotransferase were only higher in ligature/Pg group. However, we observed no significant differences between the Pg group and Control. The present study suggested a possibility that periodontitis induced by ligature placement changed serum metabolic parameter regarding organs such as the liver in DIO rat.