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，细菌破坏牙-牙龈交界处，特别是其牙附着（DAT）细胞，角化细胞被咀嚼和口腔卫生的持续创伤激活。这些快速分裂的细胞形成结合上皮（JE）的内部基底层并维持上皮附着。DAT细胞冠状端生长在间质液上，间质液通过JE渗漏到牙龈沟的底部，靠近感染细菌的部位。我们认为，赖氨酸脱羧酶（LDC），在沟中的细菌酶，耗尽漏出液的赖氨酸，饥饿的DAT细胞。少量的LDC会引起一连串的事件，诱发牙齿附着丧失和众所周知的牙周病原体在沟中定植。口腔卫生控制这种殖民化，但一些成年人是难治性和歧视增加二氧化碳噬纤维菌属。和其他最不发达国家生产者。来自龈沟中细菌的LDC的活性可能对于确定慢性牙周炎是否可以通过当前（基于口服降冰片烯的）治疗来控制至关重要。本研究的目的是：1）开发用于测量牙龈微生物群（菌斑）中活性LDC的量的新测定法;和2）使用这些测定法测量来自难治性和成功治疗的患者的沟中的活性酶。最不发达国家的活动将通过两种方法确定。第一个将确定酶活性（尸胺合成）的存在下的饱和量的底物（赖氨酸）的提取物的全口牙菌斑从难治性和成功治疗的患者。第二种将使用H-α-二氟甲基DL-赖氨酸（DFML），一种在LDC的催化中心形成加合物的自杀抑制剂。DFML尚未上市，将在未标记的情况下合成，并作为本项目的放射性衍生物。过量的未标记L-DFML或赖氨酸应抑制放射性标记加合物的形成，印迹上的放射性量将指示与菌斑提取物孵育后活性酶的量。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。结果将表明牙龈沟微生物群中LDC活性与治疗结果的关系，以及LDC抑制剂如DFML是否可能作为预防和控制慢性牙周炎的新的替代药物。