Mechanism of Myocardial Angiogenesis in Transgenic/Knockout Animals

转基因/基因敲除动物心肌血管生成机制

• 批准号: 7138758
• 负责人: NILANJANA MAULIK
• 金额: $ 35.27万
• 依托单位: UNIVERSITY OF CONNECTICUT SCH OF MED/DNT
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-06-15 至 2011-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7138758
• 关键词: NAD(H) phosphate; angiogenesis; biological signal transduction; developmental genetics; free radical oxygen; gene expression; gene targeting; genetically modified animals; growth factor receptors; ischemic preconditioning; laboratory mouse; microarray technology; myocardial ischemia /hypoxia; myocardium; oxidation reduction reaction; redoxin; thioredoxin; vascular endothelial growth factors

DESCRIPTION (provided by applicant): Neovascularization, the natural physiological process of formation of new blood vessels, is extremely important to ameliorate the function of the heart that undergoes ischemic stress. This process is potentially important for the treatment of ischemic heart and limb ischemia which includes formation of capillaries (angiogenesis) and collateral arteries. We demonstrated that ischemic preconditioning (IP) of the heart can trigger angiogenesis. Reactive oxygen species (ROS) derived from gp91phox (Nox2)-containing NAD(P)H oxidase is found to be involved in angiogenic process which involves vascular endothelial growth factor (VEGF) signaling. The role of gp91phox-derived ROS in neovascularization in response to tissue ischemia is unknown. Again to determine this redox signaling we will examine the involvement of principal redox regulated genes, thioredoxin and glutaredoxin in the IP hearts. Discerning the myriad pathways that are possibly associated with this vascular growth process is therefore of utmost importance to develop targeted drugs and bring the therapy from bench to bedside. Previous studies, including ours, also have shown that transient ischemia upregulates VEGF protein in cardiac tissues. Thus, this study will attempt to address an important clinical issue by identifying potential candidates of VEGF signaling in several gene knockout animals such as Flk-1+/-, Flt-1+/-, gp-91 phox-/-, HO-1+/+, Trx-1+/+, Grx1+/+, Grx1-/-. This study will utilize a broad multidisciplinary approach that will combine various techniques, including latest molecular biology techniques, physiology and gene targeting. Aim 1. Activation and molecular mechanism of the GSK-3beta phosphorylation and beta-catenin translocation followed by pro-angiogenic molecule VEGF expression will be investigated. Aim 2. Genetically-engineered mice will be used such as MK2-/- to identify down stream target candidates of VEGF signaling through its receptors in IP as well as ischemic reperfused myocardium in vivo Aim 3. ROS mediated stress plays significant role in VEGF induced angiogenesis through Trx and Grx protein. Aim 4.To gain insights into the mechanisms and to identify candidate genes involved in VEGF- NAD(P)H oxidase signaling in gp91phox-/- homozygous mice we will use Affymetrix Gene chip Analysis. This proposal will provide and will identify important new insights into the cellular and molecular mechanisms of the cardioprotection provided by VEGF signaling through important candidate genes.

描述（由申请人提供）：新生血管形成是形成新血管的自然生理过程，对于改善经受缺血应激的心脏的功能极其重要。该过程对于治疗缺血性心脏和肢体缺血（包括毛细血管（血管生成）和侧支动脉的形成）具有潜在的重要性。我们证明了心脏的缺血预处理（IP）可以触发血管生成。研究发现含有NAD（P）H氧化酶的gp 91 phox（Nox 2）衍生的活性氧（ROS）参与血管生成过程，而血管生成过程涉及血管内皮生长因子（VEGF）信号转导。gp 91 phox衍生的ROS在组织缺血后新生血管形成中的作用尚不清楚。再次确定这种氧化还原信号，我们将检查参与的主要氧化还原调节基因，硫氧还蛋白和谷氧还蛋白在IP心脏。因此，识别可能与这种血管生长过程相关的无数途径对于开发靶向药物并将治疗从实验室带到床边至关重要。以前的研究，包括我们的研究，也表明短暂缺血上调心肌组织中的VEGF蛋白。因此，本研究将试图通过在几种基因敲除动物中鉴定VEGF信号传导的潜在候选者，如Flk-1+/-、Flt-1+/-、gp-91 phox-/-、HO-1+/+、Trx-1+/+、Grx 1 +/+、Grx 1-/-，来解决重要的临床问题。这项研究将利用广泛的多学科方法，将联合收割机各种技术，包括最新的分子生物学技术，生理学和基因靶向。目标1.将研究GSK-3 β磷酸化和β-连环蛋白易位以及促血管生成分子VEGF表达的激活和分子机制。目标2.将使用基因工程小鼠如MK2-/-来鉴定通过IP中的VEGF受体以及体内缺血再灌注心肌的VEGF信号传导的下游靶候选物。ROS介导的应激通过Trx和Grx蛋白在VEGF诱导的血管生成中起重要作用。目的4.利用Affyssin基因芯片技术，在gp 91 phox-/-纯合子小鼠中筛选出VEGF-NAD（P）H氧化酶信号通路的候选基因，以进一步了解VEGF-NAD（P）H氧化酶信号通路的机制。这项提案将提供并将确定重要的新的见解，通过重要的候选基因VEGF信号提供的心脏保护的细胞和分子机制。