AAV Mediated Angiogenic Therapy for Coronary Disease

描述(由申请人提供)：目前冠状动脉功能不全的血管成形术或冠状动脉搭桥术的治疗可能会在大约三分之一的病例中并发再狭窄。促进血管生长的血管生成因子如血管内皮生长因子和成纤维细胞生长因子的发现刺激了将其用于治疗冠心病的研究。直接注射生长因子只会产生短暂的效果。以血浆DNA或腺病毒载体的形式传递的血管生成因子的编码基因目前正在测试中。我们建议通过AAV载体来传递血管生成因子的编码基因。AAV是一种非致病性的血管生成因子载体，是理想的载体。肌肉注射AAV载体已被证明是运送促红细胞生成素和因子IX等分泌蛋白的一种有效方式。我们的初步研究表明，AAV载体携带的血管内皮生长因子可以刺激冠状动脉闭塞小鼠心肌内新生血管的生长。这项建议的目的是：(1)除了小鼠外，我们还将使用大鼠模型来验证和推广这些初步发现；大鼠是因为更好地了解冠状动脉闭塞的病理生理后果，并且测量它们的技术已经成熟；以及小鼠是因为可以通过新的CT技术可视化冠状动脉血管的三维结构。AAV递送的血管生成因子对左心功能的影响将通过超声心动图和压力-容量导管测量来确定。(2)调控血管生成因子基因的表达，避免过度表达可能导致血管瘤的形成。我们将首先研究EPO和血管内皮生长因子基因的缺氧反应元件。或者，也将测试其他诱导式系统。(3)比较血管内皮生长因子和血管生成素基因的AAV单独和不同联合应用的效果。这些研究可能为治疗冠状动脉功能不全提供一种有效的方法。

DESCRIPTION (provided by applicant): Current treatment of coronary insufficiency with angioplasty or coronary bypass could be complicated by restenosis in about one third of the cases. The discovery of angiogenic factors that promote blood vessel growth such as VEGF and FGF has stimulated the investigation of using them for the treatment of coronary disease. Direct injection of the growth factors only produces transient effect. The gene encoding for angiogenic factors delivered in the form of plasmic DNA, or by adenoviral vectors are currently being tested. We propose to deliver the genes encoding for angiogenic factors by AAV vectors. AAV appears to be an ideal vector for the delivery of angiogenic factors as it is nonpathogenic. Intramuscular injection of AAV vectors has been shown to be an efficient way of delivering secretory proteins such as erythropoietin and Factor IX. Our preliminary studies indicate that VEGF delivered by AAV vectors into the myocardium can stimulate new blood vessel growth in the myocardium of mice with occluded coronary arteries. The aims of this proposal are: (1) We will verify and extend these preliminary findings by using a rat model in addition to the mouse; rat because the pathophysiologic consequences of coronary occlusion are better understood and the techniques for measuring them well established; and mice because the 3 dimensional structure of the coronary vasculature can be visualized by a new CT technique. Effect of AAV delivered angiogenic factors on left ventricular functions will be determined by echocardiography and measurement with the pressure-volume catheter. (2) We will regulate the expression of the genes for angiogenic factors to avoid over expression, which may cause angioma formation. The hypoxia responsive element of the Epo and VEGF gene will first be investigated. Alternatively, other inducible system will also be tested. (3) We will compare the effectiveness of AAV delivery of the genes for VEGF and angiopoietins, alone and in different combinations. These studies may lead to an effective approach for the treatment of coronary insufficiency.