Analysis of new transcription factors induced by stretch force in periodontal ligament cells

咬合创伤和牙菌斑被认为是牙周炎快速发展的协同作用，但我们对其潜在的机制知之甚少。在这项研究中，我检测了周期牵张力和牙周病细菌脂多糖对人牙周膜细胞培养上炎性细胞因子表达的影响。在高效液相培养条件下，通过循环牵拉力产生IL-6、IL-8、粒细胞集落刺激因子(G-CSF)、巨噬细胞集落刺激因子(M-CSF)和血管内皮生长因子(VEGF)。当中间普氏杆菌内毒素同时或在循环拉力刺激之前加入到高效液相培养物中时。IL-1α在高效液相培养中大量产生。循环牵拉力和中间假单胞菌联合刺激可促进IL-6、IL-8和血管内皮生长因子的产生，而t-…则可降低M-CSF的产生。更多的是协同刺激。为了阐明诱导增强的分子机制，我们检测了拉伸的HPLC上CD14的表达，CD14是一种内毒素受体，虽然非拉伸的HPLC不表达CD14，但在循环拉伸4-8h的HPLC中，CD14的表达被强烈地诱导。循环拉伸24 h，HPLC表面和上清液中的CD14的产生分别增加。蛋白激酶C(PKC)抑制剂H7可阻断拉伸后HPLC中CD14mRNA的表达，H7和抗CD14单抗MY4也可抑制拉伸后HPLC培养上清液中IL-6的产生。此外。DNA探针含有SSRE的共同序列，它与拉伸后的HPLC核提取液结合，但不与非拉伸后的HPLC核提取液结合。这些结果表明，循环拉伸力通过激活PKC诱导CD14在高效液相中的表达，SSRE与此表达有关。此外，CD14的表达可能增加了高效液相色谱对内毒素的敏感性。较少

It is thought that occlusal trauma and dental plaque synergistically contribute to the rapid progression of periodontitis, but we have little information about the underlying mechanism. In this study, I examine the effects of cyclic-stretch force and lipopolysaccharide (LPS) from periodontopathic bacteria on expressions of proinflammatory cytokines in human periodontal ligament cell (HPLC) cultures. Interleukin (IL)-6, IL-8, granulocyte colony stimulating factor (G-CSF), and macrophage colony stimulating factor (M-CSF), and vascular endothelial growth factor (VEGF) were produced by cyclic-stretch force in HPLC cultures. When Prevotella intermedia LPS added to the HPLC cultures simultaneously with or prior to the stimulation with cyclic-stretch force. IL-1α was strongly produced in the HPLC cultures. The productions of IL-6, IL-8, and VEGF were enhanced by the costimulation with cyclic-stretch force and P.intermedia LPS.On the other hand, M-CSF production in HPLC cultures decreased by t … More he costimulation. To clarify molecular mechanism of the enhancement of the induction, we examined expression of CD14, which is a LPS receptor, on stretched HPLC.Although CD14 mRNA was not expressed in non-stretched HPLC, the expression was strongly induced by cyclic-stretch force for 4-8 h in HPLC.Productions of membrane CD14 and soluble CD14 were enhanced by the cyclic-stretch force for 24 h on the surface of and in the supernatants of HPLC respectively. IL-6 production was observed even in the supernatants of stretched and non-stretched HPLC, but the production was enhanced upon serial stimulation with stretch force and P.intermedia LPS on HPLC.The protein kinase C (PKC) inhibitor H7 blocked the expression of CD14 mRNA in stretched HPLC, H7 and the anti-CD14 monoclonal antibody MY4 also suppressed the enhancement of IL-6 production in the HPLC cultures upon serial stimutation with stretch force and P.intermedia LPS.The consensus sequence of shear stress-responsive element (SSRE) was found in the 5' flanking region of the CD14 gene. In addition. a DNA probe which contained the consensus sequence of SSRE bound to nuclear extracts from stretched HPLC but not from non-stretched HPLC.These results suggest that cyclic-stretch force induces CD14 expression in HPLC through PKC activation and that SSRE is associated with the expression. In addition, the expression of CD14 may increase the sensitivity of HPLC to LPS. Less