Ventricular Remodeling in the Adapted Heart

描述(申请人提供)：血管内皮生长因子(VEGF)在血管生成健康和疾病中的核心作用使其作为抗血管生成药物在癌症等病理条件下的治疗靶点和作为促进血管生成的细胞因子治疗缺血性心脏病具有吸引力。血管内皮生长因子通过其两个酪氨酸激酶受体VEGFR1/Flt-1或VEGFR2/Flk1/KDR通过其靶蛋白MK2调节血管生成和其他方面的内皮细胞功能的复杂过程。在目前的方案中，我们将使用Flk-1、Flt-1和MK2-/-(MAPKAPKinase2)基因敲除小鼠，试图解决一个重要的临床问题，以确定在缺血预适应(IP)过程中通过其受体触发心肌保护信号的潜在下游候选血管内皮生长因子信号。通过Affymetrix基因芯片分析，我们首次证明了与WT相比，缺血损伤后Flk-1小鼠基因(Pellino-1或Peli-1、EpiRegin和NF？b)表达下调。研究已经确定了Pellino家族的候选成员，作为一种新的上游调节因子，介导MAPKAP激酶途径的激活。PELLINO(PELI)和EPIREGULIN(EPIREGULIN)是新近发现的位于血管内皮生长因子信号转导通路下游的分子，它们可能在心肌血管生成中发挥重要作用，从而抑制心室重构。ERG具有血管生成潜能，可能通过血管生成或缺血/梗死心肌血管生成促进新生血管的形成。我们这个项目的长期目标是通过我们最近在缺血心肌中探索的新分子PELI-1和ERG来了解缺血心肌中血管内皮生长因子信号转导的机制。这些分子可能参与触发PI3Kinase/MK2/NF？B通路，参与血管生成。具体目的I将确定PELI-1、2和3在IP介导的血管生成中的作用，AIM II将确定MK2和NF？B在Pellino介导的血管生成中的作用，Aim III将研究Ereg在VEGF/PI3-Kinase/MK2/NF？B介导的血管生成中的作用，Aim IV将确定NF？B在VEGF/Pellino/Pellino/EuRegulin/MK2介导的心肌血管生成中的作用和参与。基因工程的核因子B基因敲除(KO)小鼠将被用来鉴定血管内皮生长因子(VEGF)介导的信号转导，其可能通过与心肌血管生成相关的最终靶基因之一的核因子B。本研究将采用多学科的方法，包括现代分子生物学、成像、基因打靶、siRNA技术和生理学等多种技术。总之，该提议将有助于我们理解血管内皮生长因子诱导血管生成的分子机制，并可能在未来为治疗缺血性心脏病提供新的治疗策略。公共卫生相关性：了解血管内皮生长因子的信号机制是治疗缺血性心脏病的一个很有前途的医学发展，可能会改善严重缺血性心脏病患者的生活质量。

DESCRIPTION (provided by applicant): The central role of vascular endothelial growth factor (VEGF) in angiogenesis health and disease makes it attractive both as a therapeutic target for anti-angiogenic drugs in pathological conditions such as cancer and as a pro-angiogenic cytokine for the treatment of ischemic heart disease. VEGF modulates the complex process of angiogenesis and other various aspects of endothelial cell function through either of its two tyrosine kinase receptors, VEGFR1/Flt-1 or VEGFR2/Flk1/KDR via its target protein MK2. In the present proposal we will use Flk-1 , Flt-1 and MK2-/- (MAPKAPKinase2) knockout mice in an attempt to address an important clinical issue to identify potential downstream candidates of VEGF signaling through its receptors that trigger cardioprotective signal during ischemic preconditioning (IP). By Affymetrix gene chip analysis we demonstrated for the first time down regulation of genes (Pellino-1 or Peli-1, Epiregulin and NF?B) after ischemic insult to the Flk-1 mice compared to WT. Studies have identified candidates of the Pellino family as a novel upstream regulator in mediating activation of MAPKAP kinase pathway. PELLINO (Peli) and EPIREGULIN (Ereg) are the newly described molecules downstream of VEGF signaling which might play significant role in myocardial angiogenesis leading to the inhibition of ventricular remodeling. Ereg has angiogenic potential, which may contribute to de novo development of vessels by vasculogenesis or angiogenesis in ischemic/infarcted myocardium. Our long-term goal of this project is to understand the mechanism of VEGF signaling in the ischemic myocardium through newly described molecules Peli-1 and Ereg that we have explored in ischemic myocardium very recently. These are the molecules that may be involved in triggering PI3Kinase/MK2/NF?B pathway involved in angiogenesis. Specific Aim I will determine the involvement of Peli-1, 2 and 3 in IP mediated angiogenesis, Aim II will determine the involvement of MK2 and NF?B in Pellino mediated angiogenesis, Aim III will study the involvement of Ereg in VEGF/PI3-kinase/MK2/NF?B mediated angiogenesis, Aim IV will determine the role and involvement of NF?B in VEGF/Pellino/epiregulin/MK2 mediated myocardial angiogenesis. Genetically engineered NF?B knockout (KO) mice will be used to identify VEGF mediated signaling which may be through NF?B, one of the final target genes related to myocardial angiogenesis. This study will adapt multidisciplinary approach that will consist of various techniques such as modern molecular biology, imaging, gene targeting, siRNA technique and physiology. Collectively, the proposal will contribute to our understanding of the molecular mechanism of VEGF induced angiogenesis and in future may provide novel therapeutic treatment strategies against ischemic heart disease. PUBLIC HEALTH RELEVANCE: To understand VEGF signaling mechanism is a promising medical development in the treatment of ischemia that will likely improve the quality of life in patients who have severe ischemic heart disease.