Lysine decarboxylase in periodontitis patients

描述(申请人提供)：在慢性牙周炎(以前是成人牙周炎)中，细菌破坏牙根-牙龈交界处，特别是其牙本质附着(DAT)细胞，角质形成细胞因咀嚼和口腔卫生造成的持续创伤而激活。这些快速分裂的细胞形成连接上皮(JE)的内部基底板，并维持上皮附着。DAT细胞的冠端生长在间质液体上，间质液体通过JE输送到靠近细菌感染部位的牙龈沟底部。我们推测，脑沟中的一种细菌酶赖氨酸脱羧酶(LDC)耗尽了赖氨酸的漏出液，导致DAT细胞饥饿。少量LDC会引起一系列事件，容易导致牙科附着丧失和众所周知的牙周病原体对牙槽的定植。口腔卫生控制着这种定植，但一些成年人是顽固的，并因增加的头细胞吞噬菌而受到歧视。和其他最不发达国家生产商。牙周沟细菌中LDC的活性可能是决定慢性牙周炎能否通过当前的(基于口腔卫生的)治疗方法控制的关键。这项研究的目的是：1)开发新的方法来测量牙龈微生物区系(菌斑)中活性LDC的数量；以及2)使用这些方法来测量难治性患者和成功治疗患者的牙槽中的活性酶。最不发达国家的活动将通过两种方法确定。第一项研究将测定难治和成功治疗患者全口菌斑提取液中含有饱和底物(赖氨酸)时的酶活性(身体合成)。第二个将使用H-a-二氟甲基DL-赖氨酸(DFML)，这是一种自杀抑制剂，在LDC的催化中心形成加合物。DFML没有商业用途，它将在没有标记的情况下合成，并作为该项目的放射性衍生品。放射性标记的加合物的形成应被过量的未标记的L-DFML或赖氨酸所抑制，斑点上的放射性数量将指示与菌斑提取物孵育后的活性酶的量。该应用程序预测，难治性斑块中的酶活性将高于成功治疗的患者斑块中的酶活性。这些结果将表明牙龈沟微生物区LDC活性与治疗结果的关系，以及DFML等LDC抑制剂是否有可能作为预防和控制慢性牙周炎的一种新的替代药物。

DESCRIPTION (provided by applicant): In chronic (formerly adult) periodontitis, bacteria destroy the dento-gingival junction, especially its Dentally attached (DAT) cells, keratinocytes that are activated by persistent trauma from mastication and oral hygiene. These rapidly dividing cells form the internal basement lamina of junctional epithelium (JE) and maintain the epithelial attachment. The DAT cell coronal extremity grows on interstitial fluid that transudes through the JE to the base of a gingival sulcus, near the site of infecting bacteria. We posit that lysine decarboxylase (LDC), a bacterial enzyme in the sulcus, depletes the transudate of lysine, starving the DAT cells. A small amount of LDC causes a cascade of events predisposing to loss of Dental attachment and colonization of the sulci by well-known periodontopathogens. Oral hygiene controls this colonization, but some adults are refractory and discriminated by increased Capnocytophaga spp. and other LDC producers. The activity of LDC from the bacteria in gingival sulci may be critical for determining whether chronic periodontitis can be controlled by current (oral hygiene-based) therapy. The Aims of this study are to: 1) develop new assays for measuring the amount of active LDC in the gingival microbiota (plaque); and 2) use these assays for measuring active enzyme in the sulci from refractory and successfully treated patients. LDC activity will be determined by two methods. The first will determine enzyme activity (cadaverine synthesis) in the presence of a saturating amount of substrate (lysine) in extracts of whole-mouth plaque from refractory and successfully treated patients. The second will use H-a-difluoromethyl DL-lysine (DFML), a suicide inhibitor that forms an adduct at the catalytic center of LDC. DFML is not commercially available and it will be synthesized unlabeled and as a radioactive derivative for this project. Radiolabeled adduct formation should be inhibited by an excess of unlabeled L-DFML or lysine and the amount of radioactivity on blots will indicate the amount of active enzyme after incubation with plaque extracts. The application predicts that there will be more enzyme activity in refractory than in successfully treated patient plaque. The results will indicate the relationship of LDC activity in the gingival sulcular microbiota to therapeutic outcome, and whether LDC inhibitors such as DFML might have utility as a new, alternative pharmacotherapeutic for preventing and controlling chronic periodontitis.