Regulated Therapeutic Angiogenesis: for Ischemic Disease

调节治疗性血管生成：治疗缺血性疾病

• 批准号: 7035895
• 负责人: KEITH A WEBSTER
• 金额: $ 36.51万
• 依托单位: UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-04-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7035895
• 关键词: adeno associated virus group; angiogenesis; athymic mouse; cardiac myocytes; cardiovascular disorder chemotherapy; collateral circulation; gene induction /repression; gene therapy; genetic promoter element; hypoxia; ischemia; laboratory mouse; laboratory rabbit; laboratory rat; matrigel; myoblasts; myocardial ischemia /hypoxia; newborn animals; nonhuman therapy evaluation; tissue /cell culture; transfection /expression vector; vascular endothelium

DESCRIPTION (provided by applicant): Therapeutic angiogenesis involves the transfer of angiogenic growth factors to ischemic tissues to promote the growth of new blood vessels. It shows promise for the treatment of both peripheral limb ischemia andl myocardial ischemia. Current protocols including all of the clinical trials in progress use plasmid or adenoviral vectors with strong unregulated viral promoters to deliver and express vascular endothelial growth factor: (VEGF) or fibroblast growth factor genes. Powerful promoters are used because of the transient lifetime of the: vectors and the requirement for high-level short-term expression. Disadvantages include an absence of directional cues for vessel growth and lack of control over the local dose and time of exposure to the growth factors. Recent evidence suggests that this may lead to disorganized unstable vessels that are leaky and prone to form hemangiomas. We hypothesize that the signals for stimulating the growth of collateral vessels should emanate from the ischemic tissue and the duration of the stimulus should be related to the persistence of ischemia. This is the case during pathology-related angiogenesis in the adult where ischemic regions provide the directional and temporal cues for the growth of new vessels. We have developed a novel gene switch that provides such cues for pro-angiogenic growth factor genes delivered to ischemic muscle. The switch includes promoter elements that are activated by hypoxia and represser elements that conditionally silence gene expression under conditions of normal perfusion. We have confirmed the function of this switch in adenoviral vectors after transfer to ischemic skeletal and cardiac tissues. Studies are proposed here to characterize angiogenesis in models of PAOD and CAD in which the VEGF gene is delivered under the direction of the switch in semi-permanent AAV vectors. We propose to characterize the angiogenic pathway and determine the properties, function, and stability of the collateral vessels in these models. The spatial cues for collateral vessel growth, stability, and recruitment of endothelial progenitor cells will be analyzed in Matrigel plugs and intact muscle. These studies will provide a basis for evaluating the efficacy of adenoviral versus regulated vectors and address some of the outstanding mechanistic questions involved in therapeutic angiogenesis.

描述（由申请人提供）：治疗性血管生成涉及将血管生长因子转移到缺血组织以促进新血管生长的转移。 它显示出治疗两种外围肢体缺血和心肌缺血的有望。 当前的方案包括所有正在进行的临床试验，都使用具有强大不受管制病毒启动子的质粒或腺病毒载体来传递和表达血管内皮生长因子：（VEGF）或成纤维细胞生长因子基因。 使用强大的启动子是因为：向量的瞬时寿命和对高级短期表达的要求。 缺点包括缺乏方向提示血管生长以及对局部剂量的控制以及暴露于生长因子的时间。 最近的证据表明，这可能会导致漏水且容易形成血管瘤的不稳定血管。 我们假设刺激副血管生长的信号应从缺血组织中散发出来，刺激的持续时间应与缺血的持续性有关。 在成年人的病理相关血管生成期间，缺血性区域为新血管生长提供了方向和时间提示。 我们已经开发了一种新型的基因开关，该开关为递送至缺血性肌肉的促血管生长因子基因提供了这种提示。 该开关包括在正常灌注条件下有条件地沉默基因表达的缺氧和阻遏物元素激活的启动子元素。 我们已经证实了转移到缺血性骨骼和心脏组织后这种转换在腺病毒载体中的功能。 这里提出的研究是为了表征PAOD和CAD模型中的血管生成，其中VEGF基因在半永久AAV载体中的开关指导下传递。 我们建议在这些模型中表征血管生成途径，并确定附带血管的特性，功能和稳定性。 将在矩阵塞和完整的肌肉中分析副血管生长，稳定性和内皮祖细胞募集的空间提示。 这些研究将为评估腺病毒与受调节载体的功效提供基础，并解决治疗性血管生成所涉及的一些出色的机械问题。