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（由适用提供）：高水平的同型半胱氨酸（HCY）称为高型心脏病血症（HHCY）与脑血管疾病，痴呆症，中风和阿尔茨海默氏病有关。 ？氨基丁酸（GABA）刺激抑制性神经递质GABA-A受体，并降低血管痴呆和中风。该提议的新颖性是HCY专门与GABA-A受体竞争，并充当兴奋性神经递质。 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）：该提议的长期目标是了解HHCY中大脑血管重塑的机制。该提议的假设是HCY诱导MMP并抑制金属蛋白酶（TIMP）的组织抑制剂，部分是通过抑制GABA-A受体。这导致基质的降解和血脑屏障的破坏，我们将通过三个特定目的检验这一假设：具体目的＃1：确定HCY是否通过减弱GABA-A受体来衰减HCY是否会增加NADH氧化酶和ROS的水平，并降低硫氧还蛋白和过氧蛋白的水平。 NADH氧化酶活性和硫氧还蛋白在HHCy的转基因小鼠模型（胱淀粉酶（Cystathionine»合成酶，CBS-/+）和GABA-A受体无效的HHCY的脑皮层中的水平和硫氧还蛋白水平将测量和无肌酚（GABA-A受体激动剂）处理。 mRNA水平将通过Q-RT-PCR测量。特定目的＃2：确定HCY是否通过拮抗GABA-A受体来增加金属蛋白酶活性并降低TIMP活性。 MMP -2，-9，-13和TIMP -1，-2，-3和-4的水平将通过创新的2 -D Zymography，功能蛋白质组，Western印迹和Q -RT -PCR分析来测量。特定目的＃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渗透性。脑微血管通透性将通过体内视频荧光图测量，使用荧光标记的专辑。血管反应性将通过血管活性剂的局部应用来测量。这些研究将证明一种新的机制，即HHCY和血管性痴呆症期间脑微血管渗透性的变化，并将对阿尔茨海默氏病的微血管疾病产生治疗后果。