UKY DENTAL COBRE: ORAL INFECTIONS: COX-2

英国牙科 COBRE：口腔感染：COX-2

• 批准号: 7382115
• 负责人: Charles David Loftin
• 金额: $ 29.51万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-01 至 2007-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7382115
• 关键词: UKY; DENTAL; COBRE; ORAL; INFECTIONS

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Specific Aim 1. Determine the role of COX-2 in P. gingivalis-induced periodontal disease and atherosclerosis. Periodontitis is a chronic inflammatory disease resulting from microbial infection of the oral cavity. The disease is initiated by gram-negative anaerobic species including Porphyromonas gingivalis. P. gingivalis infection may produce inflammation localized within the oral cavity which results in alveolar bone resorption and may produce a systemic inflammatory response resulting from bacteremia. The systemic inflammatory response is thought to account for the increased risk of developing complications of cardiovascular disease in patients with periodontitis. Prostaglandins are a class of inflammatory mediators that are significantly increased in diseased periodontal tissues. The synthesis of prostaglandins requires the activity of a cyclooxygenase, and cyclooxygenase-2 (COX-2) is the isoform that is highly induced by gram-negative bacterial products and is increased in atherosclerotic lesions. The current studies utilized an established mouse model of P. gingivalis-induced periodontitis to examine the role of COX-2-derived prostaglandins in alveolar bone resorption and atherosclerosis. Alveolar bone resorption and cardiovascular disease resulting from P. gingivalis requires chronic infection to be established in the oral cavity of the mice. Therefore, the mice are inoculated with P. gingivalis 4 days a week, every 3rd week, over a 12 week course. We have optimized the PCR technique to confirm that chronic infection with P. gingivalis is established in the mice. We have also utilized the highly sensitive technique, real-time PCR, to examine the expression of COX-2, as well as downstream prostaglandin synthases in aortic tissue. Furthermore, we have optimized immunohistochemical analysis for detection of COX-2 protein expression in the aortas of mice. These procedures will allow us to examine the effects of P. gingivalis infection on the expression of COX-2 and downstream prostaglandin synthases. Studies are in progress to examine the effectiveness of genetic or pharmacological inactivation of COX-2 in reducing P. gingivalis-induced alveolar bone resorption and atherosclerosis in mice. Specific Aim 2. Define the role of 12/15-lipoxygenase in P. gingivalis-induced periodontal disease and atherosclerosis. Angiotensin II (AngII) markedly accelerates atherogenesis in hyperlipidemic mice. Moreover, AngII increases the expression of 12/15-lipoxygenase (12/15-LO). Deficiency of 12/15-LO markedly attenuates atherosclerosis in hyperlipidemic mice. Therefore, we sought to determine if 12/15-LO plays a role in AngII-induced vascular disease. Age matched male apolipoproteinE deficient (apoE-/-) mice or 12/15-LO deficient apoE-/- mice were infused with AngII (1,000 ng/kg/min) for 28 days. Total serum cholesterol or lipoprotein profile was not altered in 12/15-LO deficient mice following AngII infusion compared to control. 12/15-LO modestly decreased AngII-induced atherosclerotic lesion formation (12/15-LO+/+: 1.26% vs 12/15-LO-/-: 1.99%; P = 0.12) on the intimal surface of the aortic arch however, this decrease did not reach statistical significance. Additionally, 12/15-LO deficiency decreased the incidence of AngII-induced abdominal aortic aneurysm formation (12/15-LO+/+: 42% vs 12/15-LO-/-: 17%; P = 0.12) and the abdominal aortic diameter (12/15-LO+/+: 1.6 mm vs 12/15-LO-/-: 1.1 mm; P = 0.11), however, the reduction in both of these parameters did not reach statistical significance. While these results suggest 12/15-LO does not significantly alter AngII-induced atherosclerosis and AAA formation, the number of mice utilized in these studies did not result in a power of 0.08. This coupled with the trend toward a decrease in both atherosclerosis and AAA formation suggest that additional studies are required to define the effect of 12/15-LO on AngII-induced vascular disease.

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。明确目的1.探讨环氧合酶-2在牙周炎和动脉粥样硬化中的作用。牙周炎是一种由口腔微生物感染引起的慢性炎症性疾病。这种疾病是由革兰氏阴性厌氧菌引起的，包括牙龈卟啉单胞菌。牙龈假单胞菌感染可在口腔内产生炎症，导致牙槽骨吸收，并可因菌血症而产生全身炎症反应。全身炎症反应被认为是牙周炎患者发生心血管疾病并发症风险增加的原因。前列腺素是一类炎症介质，在病变牙周组织中显著增加。前列腺素的合成需要环氧合酶的活性，而环氧合酶-2(COX-2)是由革兰氏阴性细菌产物高度诱导的亚型，在动脉粥样硬化病变中增加。目前的研究利用已建立的牙龈假单胞菌诱导的小鼠牙周炎模型来研究COX-2衍生的前列腺素在牙槽骨吸收和动脉粥样硬化中的作用。牙龈假单胞菌引起的牙槽骨吸收和心血管疾病需要在小鼠的口腔中建立慢性感染。因此，在12周的疗程中，每隔3周，每周4天给小鼠接种牙龈假单胞菌。我们已经优化了聚合酶链式反应技术，以确认在小鼠中建立了牙龈假单胞菌的慢性感染。我们还利用高灵敏度的实时荧光聚合酶链式反应技术，检测了COX-2及其下游前列腺素合成酶在主动脉组织中的表达。此外，我们还优化了检测小鼠主动脉中COX-2蛋白表达的免疫组织化学分析方法。这些程序将使我们能够检查牙龈假单胞菌感染对COX-2及其下游前列腺素合成酶表达的影响。目前正在研究COX-2基因失活或药物失活在减少牙龈假单胞菌诱导的小鼠牙槽骨吸收和动脉粥样硬化中的作用。明确12/15-脂氧合酶在牙周炎和动脉粥样硬化中的作用。血管紧张素II(AngII)显著加速高脂血症小鼠的动脉粥样硬化形成。此外，血管紧张素转换酶促进12/15-脂氧合酶(12/15-LO)的表达。12/15-LO缺乏可显著减轻高脂血症小鼠的动脉粥样硬化。因此，我们试图确定12/15-LO在血管紧张素转换酶诱导的血管疾病中是否起作用。年龄匹配的雄性载脂蛋白E缺陷(apoE-/-)小鼠和12/15-LO缺陷的apoE-/-小鼠静脉注射血管紧张素转换酶II(1,000 ng/kg/min)28天。与对照组相比，12/15-LO缺陷小鼠注射血管紧张素转换酶抑制剂后，血清总胆固醇或脂蛋白水平没有改变。12/15-LO轻度减少血管紧张素Ⅱ诱导的动脉粥样硬化病变的形成(12/15-LO+/+：1.26%vs12/15-LO-/-：1.99%；P=0.12)，但这一减少无统计学意义。此外，12/15-LO缺乏降低了血管紧张素Ⅱ诱导的腹主动脉瘤的发生率(12/15-LO+/+：42%vs12/15-LO-/-：17%；P=0.12)和腹主动脉直径(12/15-LO+/+：1.6 mm vs12/15-LO-/-：1.1 mm；P=0.11)，但这两个参数的降低均无统计学意义。虽然这些结果表明12/15-LO不能显著改变血管紧张素转换酶诱导的动脉粥样硬化和AAA的形成，但这些研究中使用的小鼠数量并没有导致0.08的幂。再加上动脉粥样硬化和AAA形成均有减少的趋势，提示需要更多的研究来确定12/15-LO对血管紧张素转换酶诱导的血管疾病的影响。