Lysine decarboxylase in periodontitis patients

牙周炎患者的赖氨酸脱羧酶

• 批准号: 6572218
• 负责人: MARTIN LEVINE
• 金额: $ 14.6万
• 依托单位: UNIVERSITY OF OKLAHOMA HLTH SCIENCES CTR
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2005-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6572218
• 关键词: bacteria infection mechanism; biomarker; chronic disease /disorder; clinical research; decarboxylases; dental disorder chemotherapy; dental disorder diagnosis; dental plaque; diagnosis design /evaluation; enzyme activity; enzyme inhibitors; gingival sulcus; human subject; longitudinal human study; lysine; molecular pathology; oral bacteria; patient oriented research; periodontitis

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.

描述（由申请人提供）：在慢性（以前为成人）牙周炎中，细菌会破坏牙齿-牙龈交界处，特别是其牙齿附着（DAT）细胞，即因咀嚼和口腔卫生造成的持续创伤而激活的角质形成细胞。这些快速分裂的细胞形成连接上皮 (JE) 的内部基底层并维持上皮附着。 DAT 细胞冠状端在间质液上生长，间质液通过乙脑渗入牙龈沟底部，靠近感染细菌的部位。我们假设赖氨酸脱羧酶 (LDC)（一种存在于沟中的细菌酶）会耗尽赖氨酸的漏出液，从而使 DAT 细胞挨饿。少量的 LDC 会引起一系列事件，导致牙齿附着丧失和众所周知的牙周病原体在牙槽中定殖。口腔卫生可以控制这种定植，但一些成年人难以控制，并且会被嗜二氧化碳菌属的增加所歧视。和其他最不发达国家生产商。龈沟中细菌的 LDC 活性对于确定当前（基于口腔卫生的）治疗是否可以控制慢性牙周炎可能至关重要。本研究的目的是：1) 开发新的检测方法来测量牙龈微生物群（菌斑）中活性 LDC 的数量； 2) 使用这些测定来测量难治性和成功治疗的患者脑沟中的活性酶。 LDC 活动将通过两种方法确定。第一个将测定难治性和成功治疗患者的全口腔牙菌斑提取物中存在饱和量底物（赖氨酸）时的酶活性（尸胺合成）。第二种将使用 H-a-二氟甲基 DL-赖氨酸 (DFML)，这是一种自杀抑制剂，可在 LDC 的催化中心形成加合物。 DFML 尚未商业化，它将在未标记的情况下合成，并作为该项目的放射性衍生物。放射性标记的加合物形成应被过量的未标记的 L-DFML 或赖氨酸抑制，并且印迹上的放射性量将指示与噬菌斑提取物孵育后活性酶的量。该应用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。结果将表明龈沟微生物群中 LDC 活性与治疗结果的关系，以及 DFML 等 LDC 抑制剂是否可作为预防和控制慢性牙周炎的新的替代药物疗法。