Mechanisms of mitochondrial dysfunction in brain vasculature

脑血管线粒体功能障碍的机制

• 批准号: 8239203
• 负责人: Neetu Tyagi
• 金额: $ 37.42万
• 依托单位: UNIVERSITY OF LOUISVILLE
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-03-01 至 2017-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8239203
• 关键词: ATP Synthesis Pathway; Adenosine; Albumins; Angiography; Anti-Inflammatory Agents; Antihypertensive Agents; Antioxidants; Attenuated; Bioenergetics; Blood Vessels; Blood flow; Brain; Brain Injuries; Brain Stem; Caliber; Cerebrum; Clinical Data; Co-Immunoprecipitations; Cognitive; Collagen; Collagen Type IV; Connexin 43; Connexins; Curcumin; Cystathionine; Cytochromes; DNA; DNA Methylation; Diet; Dyes; Elastin; Electron Transport; Enzymes; Event; Extravasation; Functional disorder; Gel; Gelatin; Gelatinase B; Gene Transfer; Genes; Goals; Histocytochemistry; Homocysteine; Homocystine; Hydrolase; In Situ; Injection of therapeutic agent; Injury; Ischemia; Ischemic Stroke; Label; Lyase; Matrix Metalloproteinases; Measures; Mediating; Membrane Potentials; Messenger RNA; Metabolism; Methionine; Methylation; Mitochondria; Mitochondrial DNA; Mitochondrial Matrix; Mus; Operative Surgical Procedures; Oxidants; Oxidation-Reduction; Oxidative Stress; Oxidoreductase; Oxygen Consumption; Pathway interactions; Permeability; Plasmids; Production; Proteins; Proteolysis; Proteome; Reperfusion Injury; Reperfusion Therapy; Respiration; Reverse Transcriptase Polymerase Chain Reaction; Stress; Stroke; Testing; Therapeutic; Tight Junctions; Time; Vascular remodeling; Vasodilator Agents; Western Blotting; calcein AM; cerebrovascular; cytochrome c; gene therapy; middle cerebral artery; mitochondrial dysfunction; mitochondrial membrane; novel; prevent; repaired; response; sham surgery; small hairpin RNA; tetrahydrocurcumin

DESCRIPTION (provided by applicant): Clinical data suggest an association between elevated levels of Hcy, also known as hyperhomocysteine-mia (HHcy) and stroke. HHcy is generated due to increase in de-methylation of methionine by S-adenosine- homocysteine hydrolase (SAHH) and a decrease in methyltetrahydrofolate reductase (MTHFR) and cystathionine-y-lyase (CSE, an enzyme responsible for Hcy metabolism to H2S, a most potent vasodilator, antioxidant and anti-hypertensive agent) contribute to mitochondria dysfunction (mitophagy) and ischemic stroke. Cytochrome-C transports electrons and facilitates mitochondrial bioenergetics. Interestingly, during HHcy, cytochrome-C becomes homocysteinylated (N-Hcy-cyt-c). However, it's consequence to mitophagy and stroke is unclear. The long-term goal of this project is to understand the mechanism of mitophagy, mitochondrial repair and permeability in brain vasculature during I/R injury. Our preliminary studies suggest that during I/R ,total Hcy levels increases, causes N-Hcy-cyt-C , increases mitochondrial matrix metalloproteinase-9 (mtMMP-9), in-part degradation of mt-matrix (connexin and tight junction protein, TJP) which led to mitophagy and permeability in brain vasculature. Interestingly, THC decreases Hcy level and mitigates brain damage. Tetra hydro-curcumin (THC), a major herbal antioxidant and anti-inflammatory agent, has shown to protect brain against I/R injury. The central hypothesis of this proposal is that HHcy contributes to mitophagy mediated brain damage through N-Hcy-cyt-C in part, by increasing oxidative stress, mtMMP-9, degrades connexin-43 and TJP (Figure 1). The treatment with THC, CSE gene and SAHH shRNA gene transfer attenuates mitophagy and permeability. We will test this hypothesis by following three specific aims: Specific Aim #1: To determine whether the Hcy contributes to mitophagy, in part by inducing oxidative stress, exacerbating homocysteinylation of cytochrome-c in ischemia reperfusion and if THC, CSE and SAHH shRNA gene therapy mitigates these changes. Specific Aim #2: To determine whether the homocysteinylation of cytochrome-c activates mt-MMP-9, disruption of collagen/elastin ratio, mtCxn43 and mt-tight junction proteins in ischemia reperfusion and if THC, CSE and SAHH shRNA gene therapy ameliorate. Specific Aim #3: To determine whether Hcy alters mitochondrial (mt) bioenergetics and cerebro-vascular remodeling in ischemia reperfusion and if THC, CSE and SAHH shRNA gene therapy alleviate. These studies will demonstrate the novel mechanism of cerebrovascular remodeling and have therapeutic ramifications for mitochondrial repair in cerebral ischemic stroke. PUBLIC HEALTH RELEVANCE: These studies will delineate the mechanisms of mitophagy and cerebrovascular remodeling in brain vasculature. The treatment with dietary herbal antioxidant tetrahydrocurcumin, naked CSE DNA and SAHH shRNA gene therapy mediated stabilization of mitochondrial membrane potential by inhibition of mitochondrial DNA methylation; oxidant and proteolysis stress via novel mechanistic pathways will be powerful therapeutic strategy for preventing ischemic stroke.

描述（由申请人提供）：临床数据表明，HCY水平升高（也称为高层半胱氨酸 - 肌（HHCY）和中风）之间存在关联。由于S-腺苷 - 同半胱氨酸水解酶（SAHH）的甲基氨酸脱甲基化的增加以及甲基二氢叶酸还原酶（MTHFR）和胱胱氨而在硫代硫氨酸 - 溶剂酶（CSE）（CSE）（CSE，负责Hcy Angabolism and to h2s and topts and lytate vasipts vasipt vasipt，）代理）有助于线粒体功能障碍（线粒体）和缺血性中风。细胞色素-C传输电子并促进线粒体生物能学。有趣的是，在HHCY期间，细胞色素-C变为同型囊固醇（N-HCYT-C）。但是，这是线粒体和中风的结果尚不清楚。该项目的长期目标是了解I/R损伤过程中线粒体，线粒体修复和渗透性的机制。我们的初步研究表明，在I/R期间，总Hcy水平升高，导致N-HCYT-C，增加了线粒体基质金属蛋白酶9（MTMMP-9），主要的MT-矩阵降解（Connexin and connexin and tignexin and Inction Onkintion Protin，TJP），导致了Mitophagy和tefculitation conterity in conterity and Mitophagity and cantecation and cate incatuity。有趣的是，THC降低了HCY水平并减轻脑损伤。 TETRA氢素蛋白（THC）是一种主要草药抗氧化剂和抗炎剂，已证明可以保护大脑免受I/R损伤的影响。该提议的中心假设是，HHCY通过增加氧化应激，MTMMP-9，降解连接蛋白43和TJP来促进线索介导的脑损伤，部分地通过N-HCYT-C进行了部分损害（图1）。用THC，CSE基因和SAHH shRNA基因转移的处理可减弱线粒体和渗透性。我们将通过以下三个具体目的来检验这一假设：具体目的＃1：确定HCY是否有助于线粒体，部分是通过诱导氧化应激，加剧缺血再灌注中细胞色素-C的共生性凝固性化的，以及是否会导致THC，CSE和SAHH SHRNA GENE治疗是否会改变这些变化。具体目的＃2：确定细胞色素-C的同胱酰固定链酯化激活MT-MMP-9，胶原蛋白/弹性蛋白比的破坏，MTCXN43和MT-TOIGH连接蛋白在缺血性再灌注中是否会激活MT-MMP-9，以及是否会激活缺血性蛋白质的MT-MMP-9，以及是否会重新灌注，以及是否THC，CSE和SAHH SHHH SHRNA基因治疗。具体目的＃3：确定HCY在缺血再灌注中是否会改变线粒体（MT）生物能和脑血管重塑，以及是否可以减轻THC，CSE和SAHH SHRNA基因治疗。这些研究将证明脑血管重塑的新机制，并具有用于脑缺血性中风线粒体修复的治疗后果。 公共卫生相关性：这些研究将描述脑脉管系统中线粒体和脑血管重塑的机制。通过抑制线粒体DNA甲基化，用饮食中草药抗氧化剂四氢瓜蛋白，裸体CSE DNA和SAHH SHRNA基因治疗介导了线粒体膜电位的稳定；通过新机械途径通过新机械途径的氧化剂和蛋白水解应激将是预防缺血性中风的强大治疗策略。