Argininosuccinate lyase is an essential regulator of systemic nitric oxide produc

精氨基琥珀酸裂解酶是全身一氧化氮生成的重要调节剂

• 批准号: 8748299
• 负责人: Brendan Lee
• 金额: $ 49.13万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8748299
• 关键词: Antihypertensive Agents; Arginine; Argininosuccinate lyase deficiency; Biochemical; Biological; Blood Pressure; Blood Vessels; Case Study; Caveolins; Cells; Clinical; Clinical Research; Cohort Analysis; Complex; Cross-Over Studies; Data; Defect; Diagnosis; Dilatation - action; Disease; Dose; Double-Blind Method; Endothelial Cells; Enzymes; Equilibrium; Fibroblasts; Genetic; Genotype; Heat-Shock Proteins 90; Human; Hyperammonemia; Hypertension; Immunoprecipitation; In Vitro; Inborn Errors of Metabolism; Lead; Liver; Liver diseases; Measures; Mediating; Modeling; Morbidity - disease rate; Mus; Mutation; Natural History; Neonatal Screening; Neurocognitive; Nitrates; Nitric Oxide; Nitric Oxide Synthase; Nitrites; Pathogenesis; Patients; Pharmaceutical Preparations; Phenotype; Placebo Control; Plasma; Production; Proteins; Recurrence; Refractory; Regulation; Relative (related person); Reporting; Residual state; Risk; Sodium Nitrite; Source; Structural Models; Supplementation; Testing; Tissues; Tracer; Translating; Vascular Diseases; Vascular Endothelium; argininosuccinate lyase; base; brachial artery; endothelial dysfunction; enzyme activity; extracellular; gene therapy; hepatic ureagenesis; in vitro Assay; in vivo; insight; liver function; mouse model; novel; preclinical study; prevent; public health relevance; research study; response; stable isotope; treatment strategy; urea cycle

Project Abstract This renewal application focuses on studying the efficacy of nitric oxide (NO) supplementation as a treatment for the vascular complications in argininosuccinic aciduria (ASA) caused by deficiency of argininosuccinate lyase (ASL), the second most common urea cycle disorder and a human model of nitric oxide (NO) deficiency. ASL serves distinct catalytic vs. structural functions that provide a structural model for understanding why ASA patients defy the arginine paradox, i.e., they are unable to generate NO efficiently in spite of supplemental arginine therapy. In a proof-of-principle case study, we successfully treated an ASA patient with severe hypertension refractory to multiple antihypertensive medications with NO supplementation. Our data imply that NO deficiency at the tissue level contributes to the complications of ASA and preventing hyperammonemia alone may not prevent long-term morbidity. To translate this discovery into a new treatment strategy, we propose to answer the following questions: Aim 1. Can NO supplementation be used to treat endothelial dysfunction in patients with ASA? We will perform a double-blind, placebo-controlled, cross over study in patients with ASA. We hypothesize that a subset of ASA patients will demonstrate endothelial dysfunction due to lack of NOS-dependent NO production from the vascular endothelium and that supplementation with an NOS-independent NO source such as low dose sodium nitrite via the nutriceutical Neo40(R) would correct this defect. Aim 2. Can we develop in vitro assays that predict in vivo clinical response to NO supplementation and clinical variability? We will determine the ability of ASA trial patient fibroblasts to produce NO as measured by nitrite and nitrosothiols and correlate the clinical response and phenotype in Aim 1 with in vitro production of NO in response to arginine supplementation. Aim 3. What is the mechanistic basis of NO regulation by the ASL/NOS complex? NO synthesis may be regulated in part by the participation of NOS in both positive and negative regulatory complexes. To explore the mechanisms that regulate these structural complexes, we will test the hypothesis that NO production is controlled by a balance of negative regulatory complex involving NOS and caveolin vs. a positive, synthetic complex involving NOS and ASL. The insights from these studies may offer a paradigm for studying the diverse biological effects of NO in other disease contexts. While the pathogenesis of ASA is complex and may extend to other arginine- dependent mechanisms, our preclinical and clinical studies support the dominant contribution of NO deficiency on the endpoints tested in this study. Moreover, the approaches and mechanisms proposed here may be broadly application to dysregulation of NO in other disease states.

项目摘要 这种更新应用的重点是研究一氧化氮（NO）补充的功效 因缺乏而引起的精氨酸酸性酸尿（ASA）血管并发症的治疗 Argininoscicate裂解酶（ASL），第二常见的尿素循环障碍和人类氮模型 氧化物（否）缺乏。 ASL具有独特的催化与结构功能，为结构模型提供了 了解为什么ASA患者无视精氨酸悖论，即他们无法有效产生 补充精氨酸疗法。在原则案例研究中，我们成功治疗了ASA 患有严重高血压性耐药性多种降压药的患者，没有补充。 我们的数据表明，组织水平没有缺陷会导致ASA的并发症并防止 仅单独使用高症血症可能不能预防长期发病率。将这一发现转化为新的治疗方法 策略，我们建议回答以下问题：目标1。不能补充来治疗 ASA患者的内皮功能障碍？我们将执行双盲，安慰剂对照，交叉 ASA患者的学习过度研究。我们假设一部分ASA患者将证明内皮 功能障碍由于缺乏血管内皮的NOS依赖性NO产生而引起的功能障碍，并且 补充非NOS独立的无源来源，例如通过营养素的低剂量亚硝酸钠 Neo40（R）将纠正此缺陷。目标2。我们可以开发体外测定法以预测体内临床 对没有补充和临床变异性的反应？我们将确定ASA试用患者的能力 成纤维细胞可产生NO，如亚硝酸盐和硝基硫醇测量，并将临床反应与 AIM 1中的表型，在补充精氨酸的体外产生NO。目标3。什么是 ASL/NOS复合物没有调节的机械基础？不能部分调节合成 通过NOS参与正调节复合物。探索机制 调节这些结构复合物，我们将检验以下假设：没有生产由A控制 涉及NOS和小窝蛋白与阳性合成复合物的负调节配合物的平衡 nos和asl。这些研究的见解可能会为研究多种生物学作用提供范式 在其他疾病的情况下没有。虽然ASA的发病机理很复杂，并且可能延伸到其他精氨酸 - 依赖机制，我们的临床前和临床研究支持无缺乏的主要贡献 在本研究中测试的端点上。而且，这里提出的方法和机制可能是 在其他疾病状态中广泛应用NO失调。