牙龈卟啉单胞菌脂多糖对人主动脉内皮细胞表达ICAM-1影响的研究

目的:分别观察牙龈卟啉单胞菌(P.gingivalis)脂多糖(LPS)和大肠杆菌(E.coli)LPS对人主动脉内皮细胞(HAECs)在转录和翻译水平表达细胞间粘附分子-1(ICAM-1)的影响。方法:在体外分别以P.gingivalisLPS和E.coliLPS刺激HAECs,实时荧光定量PCR技术检测ICAM-1基因表达,蛋白质印迹技术检测ICAM-1膜蛋白表达。采用SPSS18.0软件包中ANOVA对数据进行分析。结果:P.gingivalisLPS作用6 h后开始诱导ICAM-1 mRNA表达,14 h达到高峰,22 h仍有高表达,各时间点与未刺激组相比,差异均有统计学意义(P<0.05);而E.coliLPS作用2 h后即开始诱导ICAM-1 mRNA表达,14 h达到高峰,22 h仍有高表达,各时间点与未刺激组相比差异均有统计学意义(P<0.05)。两种LPS均能在蛋白水平上调ICAM-1的表达,这种上调作用呈浓度和时间依赖,且P.gingivalisLPS的作用较之E.coliLPS要缓和。结论:P.gingivalisLPS能够在转录和翻译水平上调HAECs表达ICAM-1,提示P.gingivalisLPS在动脉粥样硬化(AS)的发生发展过程中可能发挥了重要作用。E.coliLPS可能与急性炎症性疾病有关而与AS无关。     

不同fimA基因型牙龈卟啉单胞菌对人脐静脉内皮细胞产生血管细胞黏附分子1和细胞间黏附分子1的影响

目的 观察不同fimA基因型牙龈卟啉单胞菌(Porphyromonas gingivalis,Pg)对人脐静脉内皮细胞(human umbilical vein endothelial cells,HUVEC)产生血管细胞黏附分子1(vascular cell adhesion molecule-1,VCAM-1)和细胞间黏附分子1(intercellular adhesion molecule-1,ICAM-1)的影响,探讨Pg在动脉粥样硬化发生、发展中的可能作用.方法 实验分别以PgATCC33277 (Ⅰ fimA ) 、WCSP115 (Ⅱ fimA)、W83 (Ⅳ fimA)和大肠杆菌脂多糖刺激HUVEC作为T1、T2、T3组(3个实验组)和阳性对照组,未受刺激的HUVEC作为阴性对照组;标准条件下厌氧培养上述3型Pg,将其以及大肠杆菌脂多糖分别与 HUVEC共同孵育2、6、24 h,采用流式细胞术检测HUVEC表面ICAM-1和VCAM-1的蛋白表达量,并通过激光共聚焦显微镜观察ICAM-1和VCAM-1的表达分布情况.结果 Ⅰ、Ⅱ、Ⅳ fimA型Pg刺激HUVEC后,细胞表面ICAM-1表达均增强(P<0.05),2、6、24 h表达量分别为Ⅰ fimA:60.27±5.43、80.81±1.44、85.94±2.56;Ⅱ fimA:86.69±8.81、90.19±0.00、96.18±0.48,Ⅳ fimA:59.66±0.40、85.79±4.86、96.04±2.07.除2 h时ⅠfimA与Ⅳ fimA型Pg刺激的HUVEC表面ICAM-1表达量差异无统计学意义外,其他各时间点Ⅱ、Ⅳ fimA型Pg的刺激作用均强于Ⅰ fimA型Pg(P<0.05).本研究条件下,Ⅰ、Ⅱ、Ⅳ fimA型Pg刺激HUVEC后2、6、24 h表达VCAM-1的水平均较低,各实验组与对照组间相比差异均无统计学意义(P>0.05).激光共聚焦显微镜观察显示,Pg刺激下HUVEC表达ICAM-1和VCAM-1增加,在Ⅱ、Ⅳ fimA型Pg刺激下,HUVEC中ICAM-1和VCAM-1荧光点相对较多且分布范围广.结论 牙周主要致病菌Pg毒力和致病性与其fimA基因型相关,Ⅱ fimA和Ⅳ fimA型Pg 有较强的上调HUVEC表达细胞黏附分子的能力,可能导致血管内皮功能紊乱.

Abstract：

Objective To investigate the effect of Porphyromonas gingivalis(Pg) with different fimA genotypes on vascular cell adhesion molecule-1(VCAM-1) and intercellular adhesion molecule-1(ICAM-1) production by human umbilical vein endothelial cells(HUVEC). Methods In the present study, PgATCC33277(type Ⅰ fimA genotype), WCSP 115(type Ⅱ fimA genotype), W83(type Ⅳ fimA genotype), and Escherichia coli-lipopolysaccharide (Ec-LPS) were designed as experimental group 1, 2, 3, and positive control group, respectively, to stimulate HUVEC, and the un-stimulated HUVEC were analyzed as negative control group. The three strains of Pg were cultured anaerobically in standard condition, and then the Pg cells and Ec-LPS were co-cultured with HUVEC for 2, 6, and 24 h, respectively. The amount of ICAM-1 and VCAM-1 produced by HUVEC was detected with flow cytometry(FCM). The expression of ICAM-1 and VCAM-1 by HUVEC were assayed with confocal laser scanning microscope(CLSM). ResultsThe expression of ICAM-1 on the surface of HUVEC were intensified after infected by Pg with Ⅰ, Ⅱ, and Ⅳ fimA genotypes (P<0.05). The amounts of ICAM-1 were 60.27±5.43, 80.81±1.44, and 85.94±2.56 for Pg with type Ⅰ fimA genotype, 86.69±8.81, 90.19±0.00, and 96.18±0.48 for Pg with type Ⅱ fimA genotype, 59.66±0.40, 85.79±4.86, and 96.04±2.07 for Pg with type Ⅳ fimA genotype at 2, 6 and 24 h after infection, respectively. The up-regulation effects caused by Pg with type Ⅱ and Ⅳ fimA genotypes were stronger than those caused by Pg with type Ⅰ fimA genotype at different time points except at 2 h(P<0.05). Under the present experimental condition, infected by Pg with type Ⅰ, Ⅱ and Ⅳ fimA genotypes stimulated low expression of VCAM-1 by HUVEC, it showed no significant differences among all the groups (P>0.05). Expression of ICAM-1 and VCAM-1 in Pg infected HUVEC were confirmed by CLSM. Infection of HUVEC with Pg resulted in more fluorescence staining of ICAM-1 and VCAM-1 compared with that in uninfected HUVEC cultures. Conclusions The virulence and pathogenicity of Pg is associated with its fimA genotypes, Pg with type Ⅱ and Ⅳ fimA genes possess stronger ability to stimulate HUVEC to up-regulate the expression of cell adhesion molecules, which may lead to disorders in vascular endothelial function.     

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.     

牙髓卟啉单胞菌内毒素诱导成骨细胞表达炎症因子的信号通路研究

目的检测细胞外信号调节激酶（ERK）1/2和p38丝裂原活化蛋白激酶抑制剂对牙髓卟啉单胞菌内毒素（LPS）诱导成骨细胞白细胞介素（IL）-1β mRNA和IL-6 mRNA的影响,探讨根尖周病变牙槽骨吸收的可能病理机制。方法成骨细胞MG-63经PD98059和SB203580预处理1 h后,加入牙髓卟啉单胞菌LPS作用6 h,应用逆转录聚合酶链反应（RT-PCR）检测IL-1β mRNA和IL-6 mRNA的表达水平。结果PD98059预处理后,牙髓卟啉单胞菌LPS诱导MG-63表达IL-1β mRNA的水平下降。SB203580预处理后,牙髓卟啉单胞菌LPS诱导MG-63表达IL-1β mRNA和IL-6 mRNA水平均下降。结论牙髓卟啉单胞菌LPS诱导MG-63细胞表达IL-1β mRNA依赖ERK1/2和p38MAPK信号转导通路,表达IL-6 mRNA依赖p38MAPK信号转导通路。     

牙龈卟啉单胞菌侵入对人血管内皮细胞分泌MCP-1影响的研究

目的　通过研究牙龈卟啉单胞菌（porphyrmonas gingivalis,P.g）侵入对人脐静脉内皮细胞（human umbilical vein endothelial cell,HUVEC）分泌单核细胞趋化蛋白（MCP-1）的影响,了解P.g对其趋化功能的影响。方法　建立P.g侵入HUVEC的体外模型,采用酶联免疫吸附法（ELISA）研究P.g381和P.g33277菌株侵入HUVEC 6、24 h后的培养上清液中MCP-1浓度。结果　ELISA结果显示当P.g381侵入HUVEC 6、24 h和P.g33277侵入HUVEC 6 h时,HUVEC分泌的MCP-1水平升高（P＜0.01）;P.g33277侵入HUVEC 24 h时,HUVEC分泌的MCP-1水平恢复最初水平（P=0.46）;P.g381诱导HUVEC表达MCP-1的水平高于P.g33277（P＜0.01）。结论　P.g侵入HUVEC后可促进其表达MCP-1,从而上调其趋化功能,在牙周炎与心血管疾病的相关性中可能发挥作用。     

牙龈卟啉单胞菌对不同组织来源血管内皮 细胞的作用及机制的研究进展

牙龈卟啉单胞菌是重要的牙周可疑致病菌。牙龈卟啉单胞菌可黏附、侵入并损伤血管内皮细胞,并进入远隔组织器官内,以此参与动脉粥样硬化、阿尔兹海默病等全身疾病的发生和发展过程。近年来研究发现牙龈卟啉单胞菌对不同组织来源血管内皮细胞的致病性及其作用机制均有不同。本文就牙龈卟啉单胞菌对不同组织来源血管内皮细胞的作用及机制作一综述,以拓宽牙龈卟啉单胞菌与全身性疾病的研究思路。     

Porphyromonas gingivalis and its lipopolysaccharide differentially regulate the expression of cathepsin B in endothelial cells

Porphyromonas gingivalis infection and cathepsins protease upregulation are independently implicated in atherosclerosis worsening. In this study, we evaluated the effects of P. gingivalis infection and P. gingivalis -purified lipopolysaccharide (Pg-LPS) stimulation on the expression of cathepsin B (CATB) in endothelial cells (ECs). Analysis of the enzymatic activity and expression of CATB were investigated at the messenger RNA, protein and protein-phosphorylation levels. Effects of Toll-like receptors 2 and 4 blocking on CATB activity were also analysed. Our results showed that P. gingivalis and Pg-LPS significantly increased the activity of CATB but with different kinetics. The peak of CATB activity was observed 3 h after P. gingivalis infection but it appeared 48 h after Pg-LPS stimulation. The increase of CATB activity was related to its rapid tyrosine-dephosphorylation during P. gingivalis infection, whereas the levels of CATB messenger RNAs and proteins did not vary after P. gingivalis infection or Pg-LPS stimulation. Inhibition of Toll-like-receptors 2 and 4 differentially decreased P. gingivalis and Pg-LPS CATB activations. These results showed for the first time that P. gingivalis infection rapidly affects ECs and modulates CATB activity, whereas Pg-LPS effects appear to be delayed. This study suggests that direct infection of ECs by P. gingivalis may worsen atherosclerotic plaque formation via activation of the CATB pathway.     

Differential expression of interleukin-8 and intercellular adhesion molecule-1 by human gingival epithelial cells in response to Actinobacillus actinomycetemcomitans or Porphyromonas gingivalis infection

Little is known regarding the molecules expressed by gingival epithelial cells that are involved in initiating and maintaining inflammation following the interaction with periodontal pathogens. Thus, we investigated the effect of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis infection on the expression of neutrophil chemoattractant interleukin 8 (IL-8) and the adhesion molecule intercellular adhesion molecule-1 by gingival epithelial cells. The data revealed that both IL-8 and intercellular adhesion molecule-1 expression increased after infection with A. actinomycetemcomitans (IL-8: 2- to 7-fold; intercellular adhesior molecule-1: 2.5- to 3.7-fold). IL-8 secretion reached a maximal level 6 h after the infection and the expression subsequently decreased to basal level. The increased cell surface intercellular adhesion molecule-1 expression started at 4 h after infection and reached a maximal level 14 h after the infection. In contrast, the expression of both molecules rapidly decreased 2 h after challenge with P. gingivalis. This opposite influence of A. actinomycetemcomitans and P. gingivalis infection on the expression of IL-8 and intercellular adhesion molecule-1 by gingival epithelial cells suggests that A. actinomycetemcomitans infection may initiate the recruitment of neutrophils, whereas the P. gingivalis infection may retard this process and therefore demonstrate a distinct perspective of virulence.     

牙龈卟啉单胞菌对脐静脉血管内皮细胞产生sICAM-1的影响

目的：观察牙龈卟啉单胞菌（Porphyromonas gingivalis,P.gingivalis)对人类脐静脉血管内皮细胞（human umbilical vein endothelial cells,HUVECs)产生可溶性细胞间粘附分子－1（soluble intercellular adhesion molecule-1,sICAM-1)的影响。方法：应用厌氧袋法培养P.gingivalis，并用其感染HUVECs，采和酶联免疫吸附实验（enzyme-linked immunosorbent assay,ELISA)测定培养上清中sICAM-1的含量，结果：HUVECs基础表达少量的sICAM-1;P.gingivalis剂量依赖性增强HUVECs产生sICAM-1蛋白的水平；紫外线、超声波和65℃的热处理都不能抑制P.gingivalis的作用；sICAM-1蛋白水平在P.gingivalis刺激后的4h未见改变，增高的作用从刺激后的8h开始，在12h,16h和20h继续增加。结论：活的和灭活的P.gingivalis都剂量依赖性和时间依赖性地增强HUVECs产生sICAM-1,P.gingivalis可能同样诱导牙龈血管内皮细胞表达sICAM-1，升高的sICAM-1可能参与调节牙周病炎症反应和免疫反应过程。     

Trypsin‐like protease‐active extracellular protein extracts from Porphyromonas gingivalis ATCC 33277 induce apoptosis in bovine aortic endothelial cells

Tian N, Ouyang XY. Trypsin‐like protease‐active extracellular protein extracts from Porphyromonas gingivalis ATCC 33277 induce apoptosis in bovine aortic endothelial cells. J Periodont Res 2010; 45: 650–657. © 2010 John Wiley & Sons A/S Background and Objective: Certain virulence factors participating in periodontitis may relate to cardiovascular diseases. This study was to evaluate the pro‐apoptotic effect of protein extracts from Porphyromonas gingivalis on bovine aortic endothelial cells (BAECs). Material and Methods: The BAECs were exposed to trypsin‐like protease ‐ active protein extracts from P. gingivalis, and apoptosis was examined by Hoechst 33342 staining, DNA fragmentation assay and cleaved caspase‐3 detection. When BAECs were exposed to protein extracts pretreated with trypsin‐like protease inhibitor (TLCK), the apoptosis rate was evaluated by Annexin V–propidium iodide staining. To further study the potential mechanism of the pro‐apoptotic effect, immunoblotting was used to detect expression of α‐tubulin, integrin β1 and activated ERK1/2 in BAECs treated with protein extracts or cultured in suspension. Results: After exposure to the protein extracts, BAECs exhibited loss of cell adhesion and apoptotic cell death. The pro‐apoptotic effect could be delayed by TLCK pretreatment. In addition, BAECs treated with protein extracts showed decreased levels of α‐tubulin, integrin β1 and activated ERK1/2. When BAECs were cultured in suspension, ERK1/2 activation was also inhibited, but the percentage decrease in ERK1/2 activation was less than that induced by protein extracts. Moreover, no significantly altered expression of α‐tubulin was detected in suspended cells. Conclusion: Trypsin‐like protease‐active protein extracts from P. gingivalis could induce apoptosis of BAECs. The destruction of α‐tubulin and integrin β1 and decrease of ERK1/2 activation might contribute to the pro‐apoptotic effect of the protein extracts.     

多粘菌素B和热处理对牙龈卟啉单胞菌诱导ECHUV产生sICAM-1的影响

目的：观察多粘菌素B和热处理对牙龈卟啉菌诱导人类脐静脉血管内皮细胞（endothelial cells of human umbilical vein,ECHUV）产生可溶性细胞间粘附分子－1（soluble intercellular adhesion molecule-1,sICAM-1）的影响，以探讨P．gingivalis诱导ECHUV产生sICAM-1的有效部位。方法：采用酶联免疫吸附试验（enzyme-linked immunosorbent assay,ELISA）测定培养上清中sICAM-1的含量。结果：P.gingivalis、大肠杆菌脂多糖（LPS）和肿瘤坏死因子－α（TNF－α）强烈诱导ECHUV产生sICAM-1，多粘菌素B明显抑制大肠杆菌LPS的诱导作用，热处理完全废除了TNF－α的作用，而这两种方法都不能降低P.gingivalis对ECHUV产生sICAM-1的影响。另外，P.gingivalis毒力株W83的诱导强度明显高于非毒力株ATCC33277。结论：P.gingivalis可能通过LPS以外的耐热的有效位点诱导ECHUV产生sICAM-1，这一位点可能与P.gingivalis的有效毒力因子有关。     

Porphorymonas gingivalis induces intracellular adhesion molecule‐1 expression in endothelial cells through the nuclear factor‐kappaB pathway,but not through the p38 MAPK pathway

Zhang D, Zheng H, Zhao J, Lin L, Li C, Liu J, Pan Y. Porphorymonas gingivalis induces intracellular adhesion molecule‐1 expression in endothelial cells through the nuclear factor‐kappaB pathway, but not through the p38 MAPK pathway. J Periodont Res 2011; 46: 31–38. © 2010 John Wiley & Sons A/S Background and Objective: Porphyromonas gingivalis is a major pathogen in the development and progression of periodontal disease. The aim of this study was to investigate whether endothelial intracellular adhesion molecule‐1 (ICAM‐1), an inflammation biomarker for periodontitis, could be modified by infection with either of two strains of P. gingivalis with different virulence capacities: avirulent ATCC 33277 and virulent W83. Material and Methods: We examined the expression of ICAM‐1, IκBα, phospho‐p38 MAPK and nuclear factor‐kappaB (NF‐κB) p65 in an umbilical vein endothelial cell line (ECV‐304) treated with ATCC 33277 and W83, with or without the NF‐κB antagonist MG132 and/or a specific p38 inhibitor (SB203580), by real‐time PCR, western blotting and immunofluorescence. Results: Both strains could induce ICAM‐1 expression; additionally W83 was able to increase ICAM‐1 expression more significantly than ATCC 33277. In P. gingivalis‐infected endothelial cells, both p38 MAPK and NF‐κB signaling pathways were triggered by a rapid increase of p38 MAPK phosphorylation and a more delayed degradation of IκBα, followed by the nuclear translocation of NF‐κB. It was found that ICAM‐1 production in endothelial cells was abrogated by inhibition of the NF‐κB pathway, but not by inhibition of the p38 MAPK pathway, using the inhibitors of the latter two molecules. Conclusion: The induction of ICAM‐1 by infection of umbilical vein endothelial cells with P. gingivalis might be mediated through the NF‐κB pathway, but not by the p38 MAPK pathway.     

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目的 探讨牙龈卟啉单胞菌(Porphyromonas gingivalis,P.gingivalis)W83、ATCC33277刺激人牙周膜成纤维细胞(HPDLFs)分泌基质金属蛋白酶-1(MMP-1)、金属蛋白酶组织抑制剂-1(TIMP-1)的变化.方法 本研究于2010年9月至2011年6月在中国医科大学口腔医学院中心实验室进行.将P.gingivalis W83、ATCC33277作用于HPDLFs0、6、12、24、48h后,运用酶联免疫吸附法(ELISA)检测细胞上清液中MMP-1、TIMP-1质量浓度变化,并计算MMP-1/TIMP-1值.结果 P.gingivalis感染HPDLFs的MMP-1和TIMP-1表达均增强,并呈时间依赖性;且MMP-1/TIMP-1值明显高于未感染的对照组(P＜0.05).P.gingivalis W83感染后MMP-1/TIMP-1值明显高于P.gingivalis ATCC33277(P＜ 0.05).结论 P.gingivalis具有促进HPDLFs分泌MMP-1、TIMP-1的作用,且可造成牙周组织破坏;P.gingivalis W83降解细胞外基质的能力高于P.gingivalisATCC33277.     

牙龈卟啉单胞菌脂多糖对人脐静脉内皮细胞表达趋化因子RANTES和分形素的影响

目的 观察牙龈卟啉单胞菌脂多糖（Pg-LPS）对人脐静脉内皮细胞（HUVEC）表达调节活化正常T细胞表达和分泌的趋化因子（RANTES）和分形素的影响。方法 应用不同质量浓度（200、500、1 000 ng·mL^-1）的Pg-LPS分别处理HUVEC 1、6、12、24 h,利用实时荧光定量聚合酶链反应（RT-PCR）及酶联免疫吸附（ELISA）法检测RANTES及分形素mRNA及蛋白质的表达变化。结果 在Pg-LPS与HUVEC共同培养1、6和12 h时,除培养时间为12 h、Pg-LPS质量浓度为200 ng·mL^-1组的RANTES mRNA和1 h、200 ng·mL^-1组RANTES蛋白表达与对照组无明显差异外,其余各实验组RANTES蛋白和mRNA表达量及分形素mRNA表达量均高于对照组,差异有统计学意义（P<0.05）;6 h时,二者mRNA表达量达到峰值,分别为对照组的4.88倍和6.20倍;刺激6 h后,RANTES蛋白和mRNA表达量及分形素的mRNA表达量均降低,24 h时,仅Pg-LPS质量浓度为500 ng·mL-1组与对照组相比有统计学差异（P<0.05）;分形素蛋白的表达量则仅在Pg-LPS浓度为1 000 ng·mL-1刺激6、12 h时与对照组相比有统计学差异（P<0.05）。结论 Pg-LPS感染具有上调HUVEC表达趋化因子RANTES和分形素的作用,可能在牙周炎促进动脉粥样硬化发生、发展的过程中起一定作用。     

Intracellular Adhesion Molecule‐1 Is Regulated by Porphyromonas gingivalis Through Nucleotide Binding Oligomerization Domain‐Containing Proteins 1 and 2 Molecules in Periodontal Fibroblasts

Background: The mechanism by which Porphyromonas gingivalis regulates intracellular adhesion molecule 1 (ICAM‐1) expression in human periodontal ligament cells (hPDLCs) and human gingival fibroblasts (hGFs) is unknown. The aim of this study is to investigate whether nucleotide binding oligomerization domain‐containing protein (NOD) 1 and NOD2 are involved in this process and the clinical significance of ICAM‐1 in periodontitis. Methods: hPDLCs and hGFs were treated with P. gingivalis, l ‐Ala‐γ‐d ‐glutamyl‐mesodiaminopimelic acid (an agonist for NOD1), and muramyl dipeptide (an agonist for NOD2). Alternatively, cells transfected with small interfering RNA targeting NOD1and NOD2 were treated with P. gingivalis. ICAM‐1, NOD1, and NOD2 were detected at mRNA and protein levels. In addition, clinical examinations were performed in 30 healthy controls and 40 patients with chronic periodontitis (CP) before and after treatment, and serum‐soluble ICAM‐1 (sICAM‐1) levels in these individuals were detected by enzyme‐linked immunosorbent assay. Results: This study shows that P. gingivalis caused an increase in ICAM‐1, NOD1, and NOD2 expression in periodontal fibroblasts. There was a linear correlation between ICAM‐1 and NOD1 and NOD2 levels. Activation of NOD1 and NOD2 by the specific agonist led to the upregulation of ICAM‐1, whereas knocking down NOD1 and NOD2 caused a reduction in P. gingivalis–induced ICAM‐1 production. Furthermore, sICAM‐1 levels were higher in patients with CP than in healthy controls and were positively related to the clinical periodontal parameters. After periodontal treatment, sICAM‐1 levels decreased significantly. Conclusions: The present results indicate that sICAM‐1 levels are correlated to the severity of periodontitis. NOD1 and NOD2 mediate P. gingivalis–induced ICAM‐1 production in periodontal fibroblasts. NOD1 and NOD2 could be considered potential targets for periodontal therapy.     

Porphyromonas gingivalis gingipains cause G1 arrest in osteoblastic/stromal cells

Introduction: The program for mammalian cell growth and division consists of four successive phases; G₁, S, G₂, and M. Porphyromonas gingivalis may manipulate the host cell cycle to benefit bacterial virulence expression, which likely causes the cell and tissue tropism observed in chronic periodontal infections. We examined P. gingivalis for its effects on cell‐cycle modulation in mouse ST2 osteoblastic/stromal cells. Methods: Synchronized ST2 cells were infected with P. gingivalis ATCC33277 (wild‐type, WT), gingipain‐mutants [KDP136 (ΔrgpAΔrgpBΔkgp), KDP129 (ΔrgpAΔrgpB), and KDP133 (Δkgp)], and a fimbria‐deficient mutant (KDP150) for 24 h, then the cell cycle was evaluated using flow cytometry. Cell‐cycle‐related molecule expression was examined with a microarray, as well as with quantitative real‐time polymerase chain reaction and Western blotting assays. Results: Both the WT and KDP150 strains significantly inhibited cellular proliferation and arrested the cell cycle in the G₀/G₁ phase, while the expression levels of the cell‐cycle regulatory molecules cyclin D and cyclin E were also decreased. In contrast, KDP136 did not show any effects. G₁ arrest was also clearly induced by KDP129 and KDP133, with KDP129 being more effective. Conclusion: The present findings suggest that P. gingivalis gingipains reduce cyclin expression and cause early G₁ arrest, leading to the inhibition of cellular proliferation.     

p38丝裂素活化蛋白激酶信号通路在应力调控成肌细胞分化中的作用

目的研究在C2C12细胞成肌分化过程中应力对丝裂原活化蛋白激酶（MAPKs）信号通路中p38丝裂素活化蛋白激酶（p38MAPK）信号通路的影响。方法将6孔Bio Flex培养板上贴壁培养的C2C12细胞,以0.5 Hz的加载频率和10%的细胞拉伸变形幅度,分别进行拉伸培养2、6、12、24 h,应用Western blot免疫印迹检测总p38和磷酸化p-p38（Thr180/Tyr182）蛋白的表达情况。结果周期性机械拉伸在调控C2C12成肌细胞分化过程中,p38MAPK信号通路被激活。p38MAPK信号通路蛋白磷酸化水平在较高水平;而p38MAPK通路总蛋白表达维持在一基线水平,各组之间差异无统计学意义。加入p38MAPK信号通路特异性抑制剂SB203580后再加力,Myogenin的表达明显降低。结论p38MAPK信号通路在应力介导的C2C12成肌细胞分化过程中发挥重要作用,但不是这一调控过程的唯一通路。