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）：骨盆区域的辐射可导致膀胱炎症和功能障碍。这种膀胱炎或其可能性还会增加膀胱癌的发病率，禁止对膀胱肿瘤进行放射治疗，并限制治疗其他盆腔恶性肿瘤的允许放射剂量。放射性膀胱炎的发病机制尚不清楚。它可能涉及伞细胞特有的线粒体一氧化氮（NO）合酶（mtNOS）的激活、渗透性屏障的破坏以及尿液渗入固有层。这反过来会导致炎症和固有层中胶原蛋白 III 沉积的增加。导致膀胱顺应性降低和功能障碍。我们开发了放射性膀胱炎的啮齿动物模型，其中照射导致跨上皮阻力降低，并在 12 小时内增加尿素和水的渗透性。六个月时，膀胱测压图显示膀胱顺应性和收缩间隔减少，而残余容量和基线压力增加，这些特征表明纤维化。预先用辐射防护剂锰超氧化物歧化酶 (MnSOD) 转染仅部分有效，很可能是由于过氧化物酶活性降低和过氧化氢形成过多。然而，在照射过程中使用 NOS 抑制剂进行新型膀胱内治疗，或对不含 mtNOS 的膀胱进行照射，可提供几乎完全的保护。抑制NO可阻止其与超氧化物(O2)反应形成过氧亚硝酸盐(ONO2-)，过氧亚硝酸盐可损害呼吸链的复合物I和III并导致细胞凋亡/坏死。具体目标 1 将检验电离辐射激活 mtNOS 的假设，从而产生活性氮和氧物质（RNS 和 ROS），从而破坏尿路上皮通透性屏障。我们开发了 NO 和 ONO2- 微传感器，使我们能够同时实时测量完整小鼠膀胱和培养的尿路上皮细胞中这些代谢物的变化水平。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：膀胱内给予 NOS 拮抗剂或具有过氧化物酶活性的 MnSOD 或 SOD 模拟物可保护膀胱免受放射性膀胱炎的影响。这些疗法在受辐射小鼠膀胱中的有效性将在 1 至 6 个月时通过采用渗透性测量、膀胱测量和胶原蛋白沉积的组织化学分析来评估。