ROLE OF NRF2 IN NITRERGIC MEDIAITED STOMACH MOTILITY

NRF2 在氮介导的胃动力中的作用

• 批准号: 9209154
• 负责人: PANDU R GANGULA
• 金额: $ 35.69万
• 依托单位: MEHARRY MEDICAL COLLEGE
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-12 至 2021-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9209154
• 关键词: Abdominal Pain; Adenoviruses; Affect; Age; Animals; Antioxidants; Biochemical; Biological; Biological Assay; CUL1 gene; CUL3 gene; Chronic; Complications of Diabetes Mellitus; Data; Defect; Development; Diabetes Mellitus; Diabetic mouse; Diet; Dimerization; Disease; Drug Metabolic Detoxication; Erythroid; Estradiol; Estrogens; Exclusion; Female; Functional disorder; Gastric Emptying; Gastric Tissue; Gastroparesis; Gene Expression; Gene Targeting; Gene Transfer; Genes; Glycogen Synthase Kinases; Goals; Gonadal Steroid Hormones; Hyperglycemia; Impairment; In Vitro; Intervention; Laboratories; Light; Link; Measures; Mechanics; Mediating; Methods; Molecular; Mus; NF-E2-related factor 2; Nature; Nausea and Vomiting; Neurons; Nitrergic Neurons; Nitric Oxide; Nitric Oxide Synthase Type I; Nuclear; Oxidative Stress; Pathogenicity; Pathway interactions; Patients; Pharmacology; Phase; Play; Progesterone; RBX1 gene; Reactive Oxygen Species; Relaxation; Research; Rodent Model; Role; SOD2 gene; Societies; Stomach; Supplementation; Syndrome; Testing; Transfection; Wild Type Mouse; Woman; Xenobiotics; antioxidant enzyme; antioxidant therapy; catalase; cell motility; cofactor; copper zinc superoxide dismutase; diabetic; diabetic gastroparesis; dimer; early satiety; enzyme activity; glutathione peroxidase; glycogen synthase kinase 3 beta; in vivo; motility disorder; mouse model; novel; receptor; restoration; stomach motility; tetrahydrobiopterin; transcription factor; ubiquitin-protein ligase; vector

ABSTRACT The long term goal of this proposal is to develop interventions for diabetic gastroparesis, a syndrome of delayed gastric emptying predominantly affecting women. Gastric motility dysfunction is a common complication of diabetes and can involve pathogenic oxidative stress. In rodent models, reduced nitric oxide (NO) availability as a result of inhibition of neuronal nitric oxide synthase (nNOS) and increased reactive oxygen species (ROS) has been shown to play a detrimental role in gastric motility. The transcription factor nuclear factor (erythroid-derived-2)-like 2 (NRF2) regulates the expression of Phase II antioxidant and detoxification genes. NRF2 protein stability is mainly regulated by two E3 ubiquitin ligase adaptors: CUL3/Keap1 and CUL1/SCF/TrCP. Independent of CUL3/Keap1, the GSK3/TrCP axis influences the nuclear exclusion and inactivation of NRF2. Preliminary studies indicate that expression of NRF2 and its target genes, Gclc and Gclm, are suppressed while oxidative stress is elevated in a rodent model of diabetes. We have demonstrated that loss of NRF2 (Nfe2/2-/-) resulted in decreased levels of tetrahydrobiopterin (BH4, a critical cofactor for nNOS dimerization and enzyme activity) and that this led to oxidative stress, inhibition of nNOS, reduced NO levels & gastric nitrergic neuron (neurons synthesizes nNOS)motility, and delayed gastric emptying compared to age-matched wild-type mice. These data support the notion that loss of NRF2 expression in diabetes impairs antioxidant gene expression, which deregulates NO synthesis, thereby contributing to the development of gastroparesis. We provide evidence that sex hormone estradiol-17β (E2) mediated NRF2/nNOS expression and gastric motility is impaired in the onset of diabetes. In addition, we have shown that glycogen synthase kinase 3beta (GSK-3β) or E2 regulate the synthesis of NO in female gastric tissue. This data suggest that loss of NRF2 expression during hyperglycemia is a consequence of activation of a GSK-3β/CUL1/SCF/TrCP/RBX1 axis . Our central hypothesis is that nitrergic mediated gastric motility is regulated by NRF2. Specific Aim 1 will test the hypothesis that loss of NRF2 expression during hyperglycemia is a consequence of activation of a GSK-3β/CUL1/SCF/TrCP/RBX1 axis. Specific Aim 2 will test the hypothesis that restoration of NRF2 and NRF2-regulated antioxidant enzyme expression will result in normal gastric motility and gastric emptying; and Specific Aim 3. will test the hypothesis that NRF2 and nNOS mediated gastric motility are regulated by female sex hormones; 17-estradiol (E2), progesterone and/or their gastric receptors in diabetic animals. These studies will shed light on the mechanisms of NRF2-mediated gastric nNOS motility function and thereby enhance our understanding of the pathophysiology of gastroparesis. The research outlined will potentially identify novel treatment options for diabetes-induced gastric dysmotility, particularly in females.

抽象的 该提案的长期目标是开发针对糖尿病性胃轻瘫（一种糖尿病综合征）的干预措施 胃排空延迟主要影响女性。 糖尿病并发症，并可能涉及啮齿动物模型中的致病性氧化应激，一氧化氮减少。 由于抑制神经元一氧化氮合酶 (nNOS) 和增加反应性而导致 (NO) 的可用性 氧物质（ROS）已被证明在胃蠕动中发挥着不良作用转录因子。 核因子（红细胞衍生-2）样 2 (NRF2) 调节 II 期抗氧化剂和 NRF2 蛋白稳定性主要由两个 E3 泛素连接酶接头调节： CUL3/Keap1 和 CUL1/SCF/TrCP 独立于 CUL3/Keap1，GSK3/TrCP 轴影响核。 NRF2的排除和失活初步研究表明NRF2及其靶基因的表达， 在糖尿病啮齿动物模型中，Gclc 和 Gclm 受到抑制，而氧化应激则升高。 证明 NRF2 (Nfe2/2-/-) 的缺失会导致四氢生物蝶呤 (BH4，一种关键的生物蝶呤) 水平下降。 nNOS 二聚化和酶活性的辅助因子），这导致氧化应激，抑制 nNOS， 降低一氧化氮水平和胃硝能神经元（神经元合成 nNOS）运动，并延迟胃 与年龄匹配的野生型小鼠相比，这些数据支持 NRF2 缺失的观点。 糖尿病中的表达会损害抗氧化基因的表达，从而失调一氧化氮的合成，从而 我们提供的证据表明，性激素雌二醇-17β (E2) 会导致胃轻瘫。 此外，糖尿病发病时介导的 NRF2/nNOS 表达和胃动力受损。 表明糖原合成酶激酶 3β (GSK-3β) 或 E2 调节女性胃中 NO 的合成 该数据表明，高血糖期间 NRF2 表达的丧失是 NRF2 激活的结果。 GSK-3β/CUL1/SCF/TrCP/RBX1 轴 我们的中心假设是氮能介导的胃运动是。 具体目标 1 将检验高血糖期间 NRF2 表达缺失的假设。 是 GSK-3β/CUL1/SCF/TrCP/RBX1 轴激活的结果 具体目标 2 将测试 假设恢复 NRF2 和 NRF2 调节的抗氧化酶表达将导致正常 胃动力和胃排空；以及具体目标 3. 将检验 NRF2 和 nNOS 的假设 介导的胃动力由女性性激素（17-雌二醇（E2）、黄体酮和/或其）调节； 这些研究将揭示 NRF2 介导的机制。 胃 nNOS 运动功能，从而增强我们对胃轻瘫病理生理学的理解。 概述的研究将有可能确定糖尿病引起的胃动力障碍的新治疗方案， 尤其是女性。