PTEN and Perlecan in Reducing In-Stent Restenosis

描述（由申请人提供）：所有形式的动脉介入都会损伤病变血管并诱导对该损伤的反应。对损伤的反应是一个多因素的过程，通过血管重塑或内膜增厚导致管腔大小减少。血管平滑肌细胞（SMC）的增殖和迁移显著促进内膜增厚，是支架内再狭窄的主要机制。然而，尽管血管生物学取得了重大进展，但在新生内膜形成过程中，最终调节不受控制的SMC复制的机制在很大程度上是未知的，因此增加了成功临床治疗的挑战。在没有血管损伤的情况下，成熟血管仍然是一个高度静止的组织，SMC表现出极低的每日复制率（每天0.05%）。我们实验室的研究重点是确定内源性SMC生长抑制的机制。靶向这种内源性机制的可能性将为靶向分子方法减少血管干预后病变的形成开辟新的视角。我们发表的和初步的数据将证明成熟动脉中分化的SMC产生并沉积富含硫酸肝素的perlecan到SMC基膜中。Perlecan-SMC相互作用导致PTEN活性增加，从而促进未损伤动脉的SMC静止。然而，血管损伤（如球囊血管成形术、支架置入术）导致局部胰腺蛋白水解，PTEN活性降低，细胞快速自主生长。本研究的中心论点是，腺病毒介导的肿瘤抑制因子PTEN和富含肝素硫酸酯的perlecan亚域的过表达，两种内源性SMC生长抑制剂，使用局部的、基于支架的腺病毒递送，将有效抑制支架内新内膜的形成。第一个目的是验证腺病毒传递方法的效率，并在体外系统中验证我们的中心假设。第二个目标是在体内支架部署系统中测试我们的中心假设，使用Aim 1中确定的最佳涂层配方，该配方在支架部署后提供最高水平的涂层稳定性，并结合最大程度的SMC生长抑制。我们提出的实验方法应该产生非常重要的，关于减少支架内再狭窄的独特方法的新信息。

DESCRIPTION (provided by applicant): All forms of arterial interventions injure the diseased vessel and induce a response to that injury. The response to injury is a multifactorial process and results in a reduction in lumen size either by vessel remodeling or by intimal thickening. Proliferation and migration of vascular smooth muscle cells (SMC) significantly contribute to intimal thickening and are the predominant mechanisms of in-stent restenosis. However, despite major advances in vascular biology, the mechanisms ultimately regulating uncontrolled SMC replication during neointima formation are largely unknown thus compounding the challenge of successful clinical treatment. In the absence of vascular trauma, the mature blood vessel remains a highly quiescent tissue with SMC exhibiting extremely low daily replication rates (0.05% per day). The focus of the studies in our laboratory has been to identify mechanisms of endogenous SMC growth inhibition. The possibility of targeting such endogenous mechanisms would open up new perspectives for a targeted molecular approach to reducing lesion formation following vascular interventions. Our published and preliminary data will demonstrate differentiated SMC in mature arteries produce and deposit heparan sulfate- rich perlecan into the SMC basement membrane. Perlecan-SMC interactions result in increased activity of PTEN thus contributing to SMC quiescence in the uninjured artery. However, vascular injury (e.g. balloon angioplasty, stent placement) results in local perlecan proteolysis, decreased PTEN activity, and rapid, autonomous cell growth. Our central thesis for this proposal is that combined adenoviral-mediated overexpression of the tumor suppressor PTEN and the heparan sulfate-rich subdomains of perlecan, two endogenous SMC growth inhibitors, using a localized, stent-based delivery of adenovirus will effectively inhibit in-stent neointima formation. The first Aim is proposed to verify the efficiency of the adenovirus delivery method and to test our central hypothesis in an in vitro system. The second Aim is proposed to test our central hypothesis in an in vivo stent deployment system using the optimal coating formulation determined in Aim One that provides the highest level of coating stability following stent deployment combined with the greatest degree of SMC growth inhibition. Our proposed experimental approach should yield highly significant, new information regarding a unique approach to reducing in-stent restenosis.