OVEREXPRESSION OF ENOS IN CRITICAL LIMB ISCHEMIA

描述(由申请人提供)： 尽管严重肢体缺血(CLI)的手术和基于导管的治疗取得了进展，但在美国，每年仍有15万名患者需要截肢。相信有效的分子治疗将对这些患者的残疾和肢体损失率产生显著的临床影响，本研究特别关注内皮型一氧化氮合酶(ENOS)在侧支动脉发育(动脉生成)中的作用。由于这种发育可以逆转CLI，我们的中心假说认为eNOS的过度表达将以一种逆转CLI的方式诱导侧支动脉有序和可持续的发展。具体地说，这项研究的目的是：1)确定大鼠后肢缺血模型的最佳基因转移条件；2)检查这些eNOS基因转移技术是否也可以逆转糖尿病、高龄、高胆固醇血症和吸烟的CLI临床相关动物模型；以及3)表征eNOS过度表达促进动脉形成的分子机制。为了实现这些目标，我们的研究计划采用了新的基因传递技术和传递部位。特别是，一种独特的血管隔离下动脉内基因转移的方法，导致高效和局部的转基因表达，将被用于基因转移和激光多普勒血流成像测量真皮血流将有助于实现上述目的。了解内皮型一氧化氮合酶在动脉形成中发挥强大作用的机制将有助于进一步了解调控动脉形成的基本机制，从而为CLI和其他血管疾病的治疗开辟新的治疗途径。

DESCRIPTION (provided by applicant): Despite advances in the surgical and catheter-based treatments for critical limb ischemia (CLI), 150,000 patients require lower limb amputation in the United States annually. Believing that an effective molecular therapy would have a significant clinical impact on the disability and limb loss rates in these patients, this study looks specifically at the role of endothelial nitric oxide synthase (eNOS) in collateral artery development (arteriogenesis). Because such development can reverse CLI, our central hypothesis maintains that the overexpression of eNOS will induce the ordered and sustainable development of collateral arteries in a way that will reverse CLI. Specifically, this research proposal aims 1) to identify the optimal gene transfer condition in a rat hind limb mode of ischemia; 2) to examine whether these eNOS gene transfer techniques can also reverse CLI clinically relevant animal models of diabetes, advanced age and hypercholesterolemia, and cigarette smoking; and 3) to characterize the molecular mechanisms by which eNOS overexpression increases arteriogenesis. To accomplish these aims, our research plan employs novel gene delivery techniques and sites of delivery. In particular, a unique method of intra-arterial gene transfer under vascular isolation that results in highly efficient and localized transgene expression will be used for gene transfer and laser Doppler perfusion imaging to measure dermal blood flow will facilitate the accomplishment of the above aims. Understanding the mechanisms by which eNOS exerts its powerful effects on arteriogenesis should provide additional insight into the fundamental mechanisms regulating arteriogenesis, and therefore open new therapeutic approaches for the treatment of CLI and other vascular diseases.