Mechanisms of Cerebral Vascular Remodeling

脑血管重塑的机制

• 批准号: 7845565
• 负责人: Suresh C. Tyagi
• 金额: $ 32.05万
• 依托单位: UNIVERSITY OF LOUISVILLE
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-06-01 至 2012-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7845565
• 关键词: A Mouse; Abbreviations; Adenosine Diphosphate; Agonist; Albumins; Alteplase; Alzheimer' s Disease; Antioxidants; Arginine; Attenuated; Basement membrane; Blood - brain barrier anatomy; Blood Vessels; Brain; Butyric Acids; Caliber; Cerebrum; Collagen; Cystathionine; Dementia; Diabetic Angiopathies; Disintegrins; Endothelial Cells; Extracellular Matrix; Extravasation; Fluorescence; Functional disorder; GABA-A Receptor; Gelatinase A; Gelatinase B; Goals; Heterozygote; Homocysteine; Homocystine; Hydrolase; Hyperhomocysteinemia; Knock-out; Knockout Mice; Label; Ligase; MTHFR gene; Matrix Metalloproteinases; Measures; Mediating; Messenger RNA; Metalloproteases; Methionine; Methylenetetrahydrofolate reductase (NADPH); Microvascular Permeability; Muscimol; N-Methylaspartate; NADH oxidase; NADP; Neurotransmitters; Niacinamide; Nitric Oxide Synthase; Norepinephrine; Oxidation-Reduction; Patients; Permeability; Plasma; Polymerase Chain Reaction; Process; Proteome; Reactive Nitrogen Species; Reactive Oxygen Species; Research Personnel; Secondary to; Seizures; Stress; Stroke; Structure of thyroid parafollicular cell; Testing; Therapeutic; Thioredoxin; Time; Tissue Inhibitor of Metalloproteinase-1; Tissue Inhibitor of Metalloproteinases; Topical application; Transgenic Mice; Vascular Dementia; Vascular Diseases; Vascular remodeling; Western Blotting; Wild Type Mouse; cerebrovascular; constriction; gamma-Aminobutyric Acid; human NOS3 protein; in vivo; innovation; micrography; mouse model; novel; peroxiredoxin; programs; receptor; relating to nervous system; tempol; tetrahydrobiopterin; tissue inhibitor of metalloproteinase 4; vasoactive agent

DESCRIPTION (provided by applicant): High levels of homocysteine (Hcy) known as hyperhomocysteinemia (HHcy) are associated with cerebral- vascular disease, dementia, stroke, and Alzheimer's disease. The ?-amino butyric acid (GABA) stimulates the inhibitory neurotransmitter GABA-A receptor and decreases vascular dementia and stroke. The novelty of this proposal is that Hcy specifically competes with the GABA-A receptors and acts as an excitotoxic neurotransmitter. Hcy activates cerebral vascular matrix metalloproteinases (MMPs) by inducing redox stress and reactive oxygen species (ROS): The long-term goal of this proposal is to understand the mechanisms of cerebral vascular remodeling in HHcy. The hypothesis of this proposal is that Hcy induces MMPs and suppresses tissue inhibitors of metalloproteinase (TIMPs), in part, by inhibiting the GABA-A receptor. This leads to degradation of the matrix and disruption of the blood brain barrier We will test this hypothesis by three specific aims: Specific aim #1: To determine whether Hcy increases levels of NADH oxidase and ROS, and decreases levels of thioredoxin and peroxiredoxin by attenuating the GABA-A receptor. Levels of NADH oxidase activity and thioredoxin in brain cortex of transgenic mouse model of HHcy (cystathionine ¿ synthetase, CBS -/+) and GABA-A receptor null mice treated with and without muscimol (GABA-A receptor agonist) will be measured. The mRNA levels will be measured by Q-RT-PCR. Specific aim #2: To determine whether Hcy increases metalloproteinase activity and decreases TIMP activity by antagonizing the GABA-A receptor. Levels of MMP-2, -9, -13, and TIMP-1, -2, -3, and -4 will be measured by innovative 2-D zymography, functional proteome, Western blots and Q-RT-PCR analyses. Specific aim #3: To determine whether Hcy alters brain microvascular reactivity and increases permeability of brain microvessels by augmenting GABA-A receptor. Brain microvascular permeability will be measured by in vivo video fluorography, using fluorescence-labeled albumin. The vascular reactivity will be measured by a topical application of vasoactive agents. These studies will demonstrate a novel mechanism in which brain microvascular permeability changes during HHcy and vascular dementias, and will have therapeutic ramifications for microvascular disease in Alzheimer's patients.

描述（由申请人提供）：高水平的同型半胱氨酸（Hcy）被称为高同型半胱氨酸血症（HHcy），与脑血管疾病、痴呆、中风和阿尔茨海默病有关。γ-氨基丁酸（GABA）会刺激抑制作用。该提案的新颖之处在于，Hcy 与 GABA-A 受体特异性竞争并充当神经递质 GABA-A 受体并减少血管性痴呆和中风。 Hcy 通过诱导氧化还原应激和活性氧 (ROS) 激活脑血管基质金属蛋白酶 (MMP)：该提案的长期目标是了解 HHcy 脑血管重塑的机制。 Hcy 部分地通过抑制 GABA-A 受体来诱导 MMP 并抑制金属蛋白酶组织抑制剂 (TIMP)，这会导致基质降解和基质破坏。我们将通过三个具体目标来检验这一假设： 具体目标#1：确定 Hcy 是否会增加 NADH 氧化酶和 ROS 的水平，并通过减弱 NADH 氧化酶的 GABA-A 受体水平来降低硫氧还蛋白和过氧化还原蛋白的水平。 HHcy（胱硫醚 ¿）转基因小鼠模型脑皮层的活性和硫氧还蛋白将通过 Q-RT-PCR 测量用或不用蝇蕈醇（GABA-A 受体激动剂）治疗的小鼠和 GABA-A 受体缺失小鼠的 mRNA 水平。 Hcy 是否通过拮抗 MMP-2、-9、-13 和 TIMP-1、-2、-3 和 GABA-A 受体水平来增加金属蛋白酶活性并降低 TIMP 活性。 -4 将通过创新的 2-D 酶谱、功能蛋白质组、蛋白质印迹和 Q-RT-PCR 分析进行测量 具体目标 #3：确定 Hcy 是否通过增强 GABA-A 受体来改变脑微血管反应性并增加脑微血管的通透性。脑微血管通透性将通过体内视频荧光检查，使用荧光标记的白蛋白进行测量。这些研究将通过局部应用血管活性药物来测量。证明了在 HHcy 和血管性痴呆期间脑微血管通透性发生变化的新机制，并将对阿尔茨海默病患者的微血管疾病产生治疗影响。