Down-regulation of interleukin-1alpha-induced matrix metalloproteinase-13 expression via EP1 receptors by prostaglandin E2 in human periodontal ligament cells

In the present study, we investigated the effect of prostaglandin (PG) E2 on matrix metalloproteinase (MMP)-13 production in human periodontal ligament cells stimulated with interleukin (IL)-1alpha. IL-1alpha enhanced both MMP-13 and PGE2 production. Indomethacin, a nonselective cyclooxygenase inhibitor, and NS-398, a specific cyclooxygenase-2 (COX-2) inhibitor, significantly enhanced IL-1alpha-induced MMP-13 production in periodontal ligament cells, although both the agents completely inhibited IL-1alpha-induced PGE2 production. Exogenous PGE2 reduced IL-1alpha-induced MMP-13 mRNA and protein production in a dose-dependent manner. 17-phenyl-omega-trinor PGE2, a selective EP1 receptor agonist, mimicked the inhibitory effect of PGE2 on IL-1alpha-induced MMP-13 mRNA and protein production. On the basis of these data, we suggest that COX-2-dependent PGE2 down-regulates IL-1alpha-elicited MMP-13 production via EP1 receptors in human periodontal ligament cells. PGE2 may be involved in the regulation of destruction of extracellular matrix components in periodontal lesions.     

实验性牙根吸收组织中基质金属蛋白酶-1及其抑制剂-1的定位表达

目的检测小型猪实验性牙根吸收组织中基质金属蛋白酶(MMP)-1及基质金属蛋白酶抑制剂(TIMP)-1的表达,探讨二者在牙根吸收过程中的作用。方法选用6头小型猪的12颗下颌乳侧切牙,随机分为4组,每组3颗下颌乳侧切牙,分别加力0、0.98、1.96、2.94 N,每2周加力1次。第1次加力后45 d切取标本,应用SABC免疫组化方法检测MMP-1及TIMP-1在根吸收区牙周组织中的定位表达。结果加力0.98、1.96、2.94 N时牙根吸收区牙周组织中MMP-1阳性染色均比不加力强,加力0.98、1.96 N时牙根吸收区牙周组织中TIMP-1阳性染色均比不加力强。结论MMP-1与TIMP-1参与细胞外基质的代谢活动;MMP-1与TIMP-1在根吸收活动中起着重要的作用。     

口腔鳞癌淋巴结转移与丝裂原活化蛋白激酶 激酶4基因表达的关系及其临床意义

目的 研究丝裂原活化蛋白激酶激酶4 (MKK4)在口腔鳞癌(OSCC)中的表达及其与浸润转移的关系.方法 应用免疫组织化学技术及逆转录-聚合酶链反应(RT-PCR)检测口腔鳞癌原发灶及淋巴结转移灶中MKK4蛋白和mRNA的表达.结果 75例石蜡包埋口腔鳞癌组织中,MKK4蛋白的表达在48例转移组高于27例无淋巴结转移组...     

周期性牵张力对人牙周膜细胞MMP-1 mRNA表达的影响

目的:观察周期性牵张应力对人牙周膜细胞(HPDLF)的MMP-1 mRNA表达的影响.方法:对培养在弹性膜培养板上的HPDLF施加0.2 Hz、12%形变率的周期性牵张力,利用原位杂交和反转录聚合酶链反应(RT-PCR)技术观察HPDLF的MMP-1 mRNA的表达.结果:体外培养的HPDLF正常情况下表达MMP-1 mRNA,加载周期性牵张力12 h、24 h、48 h后,随着作用时间的延长,HPDLF的MMP-1 mRNA有持续增强的趋势.结论:周期性牵张力作用下,HPDLF的MMP-1 mRNA的表达增强,加速ECM的代谢活动.     

Intermittent administration of PTH(1-34) regulates the osteoblastic differentiation of human periodontal ligament cells via protein kinase C- and protein kinase A-dependent pathways in vitro

Lossdörfer S, Kraus D, Abuduwali N, Jäger A. Intermittent administration of PTH(1–34) regulates the osteoblastic differentiation of human periodontal ligament cells via protein kinase C‐ and protein kinase A‐dependent pathwaysin vitro. J Periodont Res 2011; 46: 318–326.© 2011 John Wiley & Sons A/S Background and Objective: Intermittent parathyroid hormone (PTH) is recognized as an anabolic agent in regenerative treatment strategies for bony tissues. Periodontal ligament (PDL) cells share features that are typical of osteoblasts, including an osteoblast‐like response to stimulation with PTH, which implies a role for these cells in the regulation of repair processes following inflammatory periodontal disease. In the present study we explored the effect of intermittent administration of a PTH fragment [PTH(1–34)] on the osteoblastic differentiation of human PDL cells in vitro, and we investigated the signaling pathways used by the cells to mediate this effect. Material and Methods: PDL cells at two stages of confluence were characterized and used as a model for the role of cell maturation in the cellular response. Results: In preconfluent, less mature cultures, intermittent administration of PTH(1–34) and PTH(1–31) fragments increased alkaline phosphatase (ALP) activity and osteocalcin production, whereas intermittent administration of PTH(3–34) and PTH(7–34) had no effect. RO‐32‐0432, a specific protein kinase C inhibitor, did not inhibit the PTH(1–34) effect, whereas the protein kinase A inhibitor, H8, antagonized the PTH(1–34)‐induced increase in ALP activity and osteocalcin. In contrast, in confluent, more mature cultures, intermittent administration of PTH(1–34), PTH(3–34) and PTH(7–34) fragments, but not of the PTH(1–31) fragment, decreased ALP activity, and osteocalcin and RO‐32‐0432, but not H8, inhibited the effect. Conclusions: This study showed that the PTH(1–34) effect on ALP activity and osteocalcin production in human PDL cells is maturation state‐dependent and specific in terms of the pathways involved. Whereas in less mature cells the PTH effect is associated with cyclic AMP/protein kinase A‐dependent signaling, more mature cells seem to mediate the PTH signal primarily via protein kinase C‐dependent pathways.     

生物力刺激和促丝裂原激活蛋白激酶对骨改建的影响

生物力信号转导是骨生物学研究的热点之一.通过研究流体剪切力、细胞外基质形变等生物力刺激下成骨细胞系的应答发现,生物力信号转导涉及促丝裂原激活蛋白激酶(MAPK)信号转导通路在内的多种信号系统.生物力刺激作用于整联蛋白、钙离子通道和脂筏等感受器,激活MAPK信号转导通路并通过级联反应调节下游分子的活性,如核心结合因子-α1和激活蛋白1等转录因子,进而调控成骨细胞的功能.同时生物力刺激诱导的MAPK信号转导通路与雌激素受体、甲状旁腺素受体和1,25-二羟胆骨化醇受体等信号转导通路存在交联作用,是生物力信号转导的重要途径.     

周期性牵张力对人牙周膜细胞MMP-3及TIMP-1表达的影响

目的 :探讨周期性牵张力对人牙周膜细胞MMP -3及TIMP -1蛋白表达的影响 ,进一步阐明正畸牙牙周组织改建过程中ECM代谢调节的分子机制 .方法 :通过体外细胞培养加载系统 ,选择频率为 6周 /min ,弹性基底膜发生 12 %形变率的周期性牵张力 ,利用免疫组化及夹心ELISA检测技术 ,观察HPDLC表达MMP -3及TIMP -1的相对强度。结果 :HPDLC在体外表达MMP -3及TIMP -1。加载 3d后 ,MMP -3表达明显增强 ,与对照组相比具有显著性差异。而TIMP -1对机械力无应答。结论 :在一定条件下 ,周期性牵张力可显著影响HPDLCMMP -3蛋白的表达。为机械力作用下MMP -3参与牙周组织ECM代谢提供了直接证据     

Matrix metalloproteinase-9 and tissue inhibitor of matrix metalloproteinase-1 in blood as markers for early atherosclerosis in subjects with chronic periodontitis

Background and Objectives: An association has been found between periodontal disease and the development of atherosclerosis. We investigated the hypothesis that periodontal disease triggers the expression of matrix metalloproteinase‐9 (MMP‐9) and tissue inhibitor of matrix metalloproteinase‐1 (TIMP‐1) in blood. Increased levels of these parameters might then indicate early atherosclerosis. Material and Methods: In this cross‐sectional study, the material comprised 80 subjects with chronic periodontitis and 31 subjects with no periodontal disease. Sixteen years after diagnosis of periodontal disease ultrasonography revealed a statistically significant difference (p < 0.001) of carotid intima–media thickness between the subjects with chronic periodontitis and the periodontally healthy subjects. Matrix metalloproteinase‐9 and TIMP‐1 were analyzed from blood as periodontal and systemic inflammatory markers. The relationship between MMP‐9, TIMP‐1 and MMP‐9/TIMP‐1 as dependent variables and several independent variables (age, sex, smoking, education, body mass index, hypertension, periodontal disease and cholesterol) were analyzed in multiple logistic regression models to assess the value of the inflammatory markers in predicting carotid atherosclerosis. Results: Matrix metalloproteinase‐9 and TIMP‐1 were significantly higher in plasma from subjects with periodontal disease and atherosclerosis. Periodontal disease was identified as the principal independent predictor both for atherosclerosis (odds ratio 3.89 for increase in bilateral carotid intima–media thickness) and for increased MMP‐9, TIMP‐1 and MMP‐9/TIMP‐1 (odds ratio 2.58, 5.53 and 3.41, respectively). Classical atherosclerosis risk factors, such as increased total cholesterol, age and sex (women), were significant predictors in the model. Conclusion: Matrix metalloproteinase‐9, TIMP‐1 and MMP‐9/TIMP‐1 in blood from subjects with periodontal disease could be useful laboratory markers for increased carotid artery intima–media thickness.     

釉基质蛋白对人牙周膜细胞总蛋白含量和超微结构的影响

目的：观察釉基质蛋白对人牙周膜细胞总蛋白含量及超微结构的影响。方法：组织块法培养人牙周膜细胞。考马斯亮蓝法测定人牙周膜细胞的总蛋白含量。透射电镜技术观察细胞超微结构。结果：釉基质蛋白质量浓度在50mg／L时即可明显增加人牙周膜细胞的总蛋白含量，l00mg／L时细胞的总蛋白含量增加到最大，此时，细胞的超微结构显示：核仁明显，粗面内质网及高尔基复合体发达。结论：釉基质蛋白能促进人牙周膜细胞核酸及蛋白质的合成活性。     

牙周炎症时基质金属蛋白酶-9的表达与胎膜早破的关系

目的分析牙周状况与胎膜早破的关系,为孕前及孕期妇女口腔疾病防治提供依据。方法选择18例早产胎膜早破孕妇设为PPROM组,20例足月胎膜早破孕妇设为PROM组,28例足月正常孕妇作为对照组,检查并记录3组的菌斑指数（PLI）、探诊深度（PD）和龈沟出血指数（SBI）,并采用免疫组织化学法检测宫颈部胎膜基质金属蛋白酶-9（MMP-9）的分布与表达,分析MMP-9与牙周状况的关系。结果PPROM组和PROM组胎膜MMP-9的表达强度均高于对照组,且差异有统计学意义。绒毛膜中MMP-9表达与PD没有相关性（r=0.053,P=0.075）,与SBI呈正相关（r=0.433,P<0.05）,与PLI呈正相关（r=0.310,P<0.05）。羊膜中MMP-9表达与PD没有相关性（r=0.077,P=0.597）,与SBI呈正相关（r=0.430,P<0.05）,与PLI呈正相关（r=0.324,P<0.05）。结论MMP-9参与了胎膜早破及牙周炎症的病理过程。     

Possible involvement of extracellular signal-regulated kinases 1/2 in mitogenic response of periodontal ligament cells to enamel matrix derivative

The efficacy of enamel matrix derivative (EMD) as an adjunct to periodontal regenerative therapy has been demonstrated in recent clinical studies, however, little is known about its molecular mechanism (s). We examined the mitogenic response of cultured periodontal ligament (PDL) cells to EMD and characterized associated changes in proliferation-related intracellular signaling molecules, including mitogen-activated protein kinases (MAPK) and Akt kinases/protein kinase B (Akt/PKB) kinases. The DNA synthesis of PDL cells increased following treatment with EMD at concentrations higher than 1 microg ml(-1). This mitogenic response to EMD was associated with the selective activation of extracellular signal-regulated kinase (ERK) 1/2. No other MAPKs, or Akt/PKB kinases, responded to EMD stimulation. The EMD induction of DNA synthesis and activation of ERK 1/2 were diminished by pretreatment with suramin, an inhibitor of receptor tyrosine kinases (RTK). The signaling pathway induced by EMD from RTK to ERK 1/2 was similar to that activated by epidermal growth factor (EGF), although the specific binding of 125I-EGF to PDL cells was not affected by pretreatment or concomitant treatment with EMD. These findings suggest that EMD elicits its mitogenic signal through an EMD-specific RTK towards ERK 1/2.     

Mitogen-activated protein kinases mediate interleukin-1beta-induced receptor activator of nuclear factor-kappaB ligand expression in human periodontal ligament cells

BACKGROUND AND OBJECTIVE: Interleukin-1beta-stimulated receptor activator of nuclear factor-kappaB ligand (RANKL) expression in human periodontal ligament cells is partially mediated by endogenous prostaglandin E2, whereas mitogen-activated protein kinases (MAPKs) are implicated in regulating various interleukin-1-responsive genes. We investigated herein the involvement of MAPKs in interleukin-1beta-stimulated RANKL expression in human periodontal ligament cells. MATERIAL AND METHODS: Human periodontal ligament cells were pretreated separately with specific inhibitors of MAPKs, including extracellular signal-regulated kinase, p38 MAPK and c-Jun N-terminal kinase, and subsequently treated with interleukin-1beta. Following each treatment, the phosphorylation of each MAPK, the expression of RANKL, and the production of prostaglandin E2 were determined. RANKL activity was evaluated using an assay to determine the survival of prefusion osteoclasts. RESULTS: Interleukin-1beta induced RANKL expression at the mRNA and protein levels, as well as RANKL activity in human periodontal ligament cells. Interleukin-1beta also activated extracellular signal-regulated kinase, p38 MAPK, and c-Jun N-terminal kinase. Pretreatment with each MAPK inhibitor partially, but significantly, suppressed interleukin-1beta-induced RANKL expression and its activity, as well as prostaglandin E2 production. CONCLUSION: In human periodontal ligament cells, three types of MAPK inhibitor may abrogate RANKL expression and activity induced by interleukin-1beta, directly or indirectly through partial suppression of prostaglandin E2 synthesis. In addition, extracellular signal-regulated kinase, p38 MAPK, and c-Jun N-terminal kinase signals may co-operatively mediate interleukin-1beta-stimulated RANKL expression and its activity in those cells.