Roles of Nitric Oxide and Superoxide in Cystitis

一氧化氮和超氧化物在膀胱炎中的作用

• 批准号: 6913876
• 负责人: Anthony John Kanai
• 金额: $ 32.79万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-01 至 2010-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6913876
• 关键词: biosensor device; collagen; digital imaging; drug screening /evaluation; enzyme activity; enzyme inhibitors; free radical oxygen; histochemistry /cytochemistry; interstitial cystitis; laboratory mouse; mitochondria; neoplasm /cancer radiation therapy; nitric oxide; nitric oxide synthase; nonhuman therapy evaluation; pelvis neoplasms; peroxynitrites; radioprotective agents; superoxide dismutase; superoxides; therapy adverse effect; tissue /cell culture; urinary bladder epithelium

DESCRIPTION (provided by applicant): Irradiation of the pelvic region can result in bladder inflammation and dysfunction. This cystitis or its likelihood also increases the incidence of bladder cancer, prohibits radiation treatment for bladder tumors, and limits the allowable radiation dose for treating other pelvic malignancies. The mechanism of radiation cystitis is unclear. It may involve activation of a mitochondria nitric oxide (NO) synthase (mtNOS) unique to the umbrella cells, disruption of the permeability barrier and infiltration of urine into the lamina propria. This in turn can lead to inflammation and increased collagen III deposition in the lamina propria. Decreased bladder compliance and dysfunction result. We have developed rodent models of radiation cystitis where irradiation results in decreased transepithelial resistance and increased urea and water permeabilities within 12 hours. At six months, cystometrograms show that bladder compliances and intercontractile intervals are decreased while residual volumes and baseline pressures are increased-features indicative of fibrosis. Prior transfection with the radioprotectant manganese superoxide dismutase (MnSOD) is only partially effective, most likely due to decreased peroxidase activity and excess hydrogen peroxide formation. However, novel intravesical therapy with a NOS inhibitor during irradiation, or irradiation of bladders devoid of mtNOS, offers almost complete protection. Inhibition of NO can prevent its reaction with superoxide (O2) to form peroxynitrite (ONO2-), which can damage complexes I and III of the respiratory chain and lead to apoptotic/necrotic cell death. Specific Aim 1 will test the hypothesis that ionizing radiation activates mtNOS, resulting in reactive nitrogen and oxygen species (RNS and ROS) which disrupt the urothelial permeability barrier. We have developed NO and ONO2- microsensors which allow us to simultaneously measure in real-time, the changing levels of these metabolites in intact mouse bladders and cultured urothelial cells. These measurements will be correlated with assayed changes in mitochondrial enzyme functions. Specific Aim 2 will test the hypothesis that the intravesical administration of NOS antagonists or MnSOD or SOD mimetics with peroxidase activity protect the bladder against radiation cystitis. The effectiveness of these therapies in irradiated mouse bladders will be assessed at 1 to 6 months by employing permeability measurements, cystometry and histochemical analyses for collagen deposition.

描述（由申请人提供）：骨盆区域的照射会导致膀胱炎症和功能障碍。这种膀胱炎或其可能性也增加了膀胱癌的发生，禁止膀胱肿瘤的辐射治疗，并限制了治疗其他骨盆恶性肿瘤的允许辐射剂量。辐射膀胱炎的机制尚不清楚。它可能涉及激活线粒体一氧化氮（NO）合酶（MTNOS），伞状细胞独有的激活，破坏了渗透性屏障和尿液浸润到普遍的层中。反过来，这可能导致炎症并增加胶原蛋白III的沉积。膀胱依从性和功能障碍结果降低。我们已经开发了辐射膀胱炎的啮齿动物模型，在12小时内，辐射会导致递增的旋转耐药性降低，尿素和水的渗透率增加。六个月时，膀胱图表明，膀胱征服和收缩间隔减少，而残余体积和基线压力增加表明纤维化。先前用放射保护剂锰超氧化物歧化酶（MNSOD）转染仅部分有效，这很可能是由于过氧化物酶活性降低和过量的过氧化氢的形成。然而，在辐照过程中使用NOS抑制剂的新型静脉疗法或没有mtnos的膀胱辐射提供了几乎完全的保护。抑制NO可以阻止其与超氧化物（O2）的反应形成过氧亚硝酸盐（ONO2-），这会损害呼吸链的复合物I和III并导致凋亡/坏死细胞死亡。具体目标1将测试电离辐射激活mTNO的假设，从而导致反应性氮和氧（RNS和ROS）破坏了尿路上皮通透性屏障。我们已经开发了NO和ONO2-微传感器，使我们可以实时测量这些代谢物在完整的小鼠膀胱和培养的尿路上皮细胞中的变化水平。这些测量结果将与线​​粒体酶功能的测定变化相关。具体目标2将检验以下假设：静脉内施用NOS拮抗剂或MNSOD或具有过氧化物酶活性的SOD MIMETICS可保护膀胱免受辐射膀胱炎的影响。这些疗法在辐照小鼠膀胱中的有效性将在1到6个月时通过采用渗透性测量，囊肿和组织化学分析来评估胶原蛋白沉积。