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.

摘要 该提案的长期目标是开发糖尿病胃轻瘫的干预措施， 胃排空延迟主要影响女性。胃动力障碍是一种常见的 糖尿病并发症，并可能涉及致病性氧化应激。在啮齿动物模型中， (NO)由于神经元型一氧化氮合酶（nNOS）的抑制和反应性增加， 氧物质（ROS）已显示在胃运动中起有害作用。转录因子 核因子（红细胞衍生的-2）样2（NRF2）调节II相抗氧化剂的表达， 解毒基因NRF2蛋白稳定性主要由两个E3泛素连接酶衔接子调节： CUL3/Keap1和CUL1/SCF/TrCP。不依赖于CUL3/Keap1，GSK 3/TrCP轴影响细胞核的表达。 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被抑制，而氧化应激升高。我们有 研究表明，NRF2（Nfe 2/2-/-）的缺失导致四氢生物蝶呤（BH 4，一种关键的 nNOS二聚化和酶活性的辅因子），这导致氧化应激，nNOS的抑制， 降低NO水平和胃氮能神经元（合成nNOS的神经元）运动，并延迟胃排空。 与年龄匹配的野生型小鼠相比，这些数据支持了NRF2的缺失 在糖尿病中的表达损害抗氧化剂基因的表达，从而使NO合成失调， 从而导致胃轻瘫我们提供的证据表明，性激素雌二醇-17 β（E2） 在糖尿病的发病中，NRF2/nNOS介导的表达和胃动力受损。另外我们有 结果表明，糖原合成酶激酶3 β（GSK-3 β）或E2调节女性胃粘膜NO的合成， 组织.这些数据表明，在高血糖期间NRF2表达的丧失是高血糖时NRF2激活的结果。 GSK-3 β/CUL1/SCF/TrCP/RBX1轴。我们的中心假设是，氮能介导的胃动力是 由NRF2控制。特异性目的1将检验高血糖期间NRF2表达丧失的假设， 是GSK-3 β/CUL1/SCF/TrCP/RBX1轴激活的结果。具体目标2将测试 假设NRF2和NRF2调节抗氧化酶表达的恢复将导致正常的 胃运动和胃排空;和特异性目标3。将检验NRF2和nNOS 介导的胃运动由雌性性激素调节; 17 β-雌二醇（E2）、孕酮和/或它们的组合。 糖尿病动物的胃受体。这些研究将阐明NRF2介导的细胞凋亡的机制。 胃nNOS运动功能，从而提高我们对胃轻瘫的病理生理学的理解。 这项研究将有可能为糖尿病引起的胃动力障碍确定新的治疗选择， 尤其是女性。