Ventricular Remodeling in the Adapted Heart

描述（由申请人提供）：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具有吸引力，无论是作为病理条件（如癌症）的抗血管生成药物的治疗靶点，还是作为治疗缺血性心脏病的促血管生成细胞因子。VEGF通过其两种酪氨酸激酶受体VEGFR1/Flt-1或VEGFR2/Flk1/KDR中的任何一种，通过其靶蛋白MK2调节血管生成的复杂过程和内皮细胞功能的其他各个方面。在目前的提议中，我们将使用Flk-1， Flt-1和MK2-/- (MAPKAPKinase2)敲除小鼠，试图解决一个重要的临床问题，即通过其受体在缺血预处理（IP）期间触发心脏保护信号来识别VEGF信号的潜在下游候选者。通过Affymetrix基因芯片分析，我们首次证实了Pellino-1或Pellino-1、Epiregulin和NF？B)与WT相比，Flk-1小鼠缺血损伤后的Flk-1小鼠。研究已经确定了Pellino家族的候选基因，作为介导MAPKAP激酶途径激活的新型上游调节因子。PELLINO （Peli）和EPIREGULIN （Ereg）是新近发现的VEGF信号下游分子，可能在心肌血管生成中起重要作用，从而抑制心室重构。Ereg具有血管生成潜能，可能通过缺血/梗死心肌的血管生成或血管生成促进血管的新生发育。我们这个项目的长期目标是通过我们最近在缺血心肌中发现的新描述的分子Peli-1和Ereg来了解VEGF在缺血心肌中的信号传导机制。这些是可能参与触发PI3Kinase/MK2/NF的分子？B通路参与血管生成。特异性Aim I将确定Peli-1、2和3参与IP介导的血管生成，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，Aim IV将决定NF的作用和参与？B在VEGF/Pellino/epiregulin/MK2介导的心肌血管生成。基因工程NF？B基因敲除（KO）小鼠将用于鉴定VEGF介导的信号传导，这可能是通过NF？B，心肌血管生成相关的最终靶基因之一。本研究将采用多学科方法，包括现代分子生物学、影像学、基因靶向、siRNA技术和生理学等多种技术。总的来说，这一建议将有助于我们理解VEGF诱导血管生成的分子机制，并在未来可能为缺血性心脏病提供新的治疗策略。公共卫生相关性：了解VEGF信号机制在治疗缺血方面是一个有希望的医学进展，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.