Targeted Gene Therapy of Heart Failure Post Myocardial Infarction

项目总结 心力衰竭(HF)仍然是一个严重的公共卫生问题，尽管最近在医学上取得了进展。目前 现有的药物只针对心力衰竭的症状，因此迫切需要新的根治方法。 基因治疗已经被提出作为这样一种有希望的方法；不幸的是，许多候选基因 如果全身给药会导致严重的临床副作用。此外，相当大的交货损失 靶外器官的载体需要使用高剂量的载体才能达到治疗效果 病变组织部位。为了应对这些挑战，我们建议工程腺相关病毒(AAV) 可专门针对心肌梗死(MI)后受损的心脏组织的载体。关键的科学 这个项目的前提是观察到细胞外蛋白水解酶，特别是基质金属蛋白酶 (MMPs)在心肌梗死后受损的心脏组织中升高。我们已经开发了一个平台-- 可激活的AAV载体可以传递基因，以响应MMPs在心肌梗死后的升高。充满希望地，在 静脉注射，我们的工程化AAV载体能够获得显著改善的靶基因 体内递送到患病心脏的高基质金属蛋白酶区域，这种靶向递送伴随着 减少了对非靶器官的输送。在这个R01项目中，我们的目标是设计、构建和表征一个 用于HF治疗的可激活蛋白酶的AAV载体的改进组合。在目标1中，我们将创建AAV载体 可以针对心肌梗死后不同的疾病阶段。在目标2中，我们将使用分子建模和结构 研究AAV衣壳变异体并进一步改进我们的载体设计的方法。然后在《目标3》中，我们将 使用体内分子成像来表征工程载体的体内特异性 心肌梗死后心肌组织中基质金属蛋白酶水平升高。最后，在目标4中，我们将测试使用 心肌梗塞所致心力衰竭体内模型中可激活的AAV载体。总体而言，通过提高 AAV载体用于靶向心脏组织，我们的目标是(I)克服使用侵入性给药的需要 战略；(2)最大限度地减少对目标外器官的输送，从而减少副作用和减少 达到治疗效果所需的总载体剂量，以及(Iii)减少任何剂量依赖的免疫 对载体的响应。

PROJECT SUMMARY Heart failure (HF) remains a serious public health concern despite recent advances in medicine. Currently available drugs only address symptoms of HF, thus new approaches for curative therapies are sorely needed. Gene therapy has been proposed as one such promising approach; unfortunately, many candidate genes would lead to serious clinical side effects if delivered systemically. Additionally, considerable loss of delivery vectors to off-target organs require high vector doses to be used in order to achieve therapeutic effect at diseased tissue sites. To address these challenges, we propose to engineer adeno-associated virus (AAV) vectors that can specifically target cardiac tissue damaged after a myocardial infarction (MI). The key scientific premise of this project is the observation that extracellular proteases, specifically matrix metalloproteinases (MMPs) are elevated in damaged cardiac tissue post-MI. We have developed a platform of protease- activatable AAV vectors that can deliver genes in response to the MMPs elevated post-MI. Promisingly, upon intravenous injection, our engineered AAV vectors are able to achieve significantly improved targeted gene delivery to the high MMP region of the diseased heart in vivo, and this targeted delivery is accompanied by decreases in delivery to non-target organs. In this R01 project, we aim to design, build, and characterize an improved panel of protease-activatable AAV vectors for HF treatment. In aim 1, we will create AAV vectors that can target different disease stages post-MI. In aim 2, we will use molecular modeling and structural approaches to study the AAV capsid variants and to further improve our vector designs. Then in aim 3, we will use in vivo molecular imaging to characterize the in vivo specificity of the engineered vectors in relation to elevated MMP levels in the heart post-MI. Finally, in aim 4 we will test the therapeutic efficacy of using the protease-activatable AAV vectors in in vivo models of MI-induced HF. Overall, by improving the specificity of AAV vectors for target cardiac tissues, we aim to (i) overcome the need to use invasive administration strategies; (ii) minimize delivery to off-target organs, leading to decreased side effects as well as decreased overall vector dosage needed to achieve therapeutic effect, and (iii) reduce any dose-dependent immune responses against the vector.