Targeting the Extracellular Matrix to Inhibit Saphenous Vein Graft (SVG) Failure

描述（由申请人提供）：本申请的目标是Matrexa开发一种蛋白质产品，用于预防人隐静脉移植物（SVG）的内膜增生，以降低这些手术过程中极高的失败率。该策略包括在手术时使用由Matrexa开发的专有药物对隐静脉进行急性预处理。干预的目标是大血管基质蛋白多糖（versican），它是平滑肌生长和增生、致动脉粥样硬化脂质积累和巨噬细胞进入病变发展的核心。我们已经成功地靶向了versican，并通过过表达versican小变体V3 （V3）和过表达versican反义序列，在动脉粥样硬化动物模型中阻止了这些事件。我们还发现了这些方法的另一个意想不到的好处，即V3促进了弹性纤维的合成和形成，并显着提高了处理血管的机械性能和稳定性。弹性纤维一旦形成，将保持血管壁的结构完整性、抗增生性和抗炎性。通过缺失研究，我们进一步发现V3的外显子3含有这种弹性活性。然而，我们认识到，由于安全和其他原因，基因传递和V3的过表达在治疗上存在问题，因此我们建议开发和使用rV3蛋白和小肽作为治疗剂。在初步研究中，我们已经成功地生产出具有弹性活性的rV3。该项目的目的是：1)制备足够数量和纯度的rV3蛋白，以在生化和体外细胞实验中检测其生物活性；2)在体外培养的人隐静脉中，证明rV3在预防内膜增生和促进弹性形成方面的功效。

DESCRIPTION (provided by applicant): The goal of this proposal is for Matrexa to develop a protein product that will prevent intimal hyperplasia in human saphenous vein grafts (SVG) with the objective of reducing the exceedingly high failure rate of these surgical procedures. The strategy involves acute pre-treatment of saphenous veins at the time of surgery with proprietary agents, developed by Matrexa. The target for intervention is the large vascular matrix proteoglycan, versican, which is central to smooth muscle growth and hyperplasia, accumulation of atherogenic lipids, and macrophage ingress into developing lesions. We have successfully targeted versican and prevented these events in animal models of atherosclerosis through over expression of the small variant versican V3 (V3) and through over expression of versican antisense sequences. We have also discovered an additional and unexpected benefit of these approaches in that V3 promotes the synthesis and formation of elastic fibers and markedly improves the mechanical properties and stability of treated vessels. Once formed, the elastic fibers will maintain the structural integrity, anti-hyperplastic and anti-inflammatory nature of the vascular wall. We have further discovered, through deletion studies, that exon 3 of V3 contains this elastogenic activity. We recognize, however, that gene delivery and overexpression of V3 is therapeutically problematic for safety and other reasons and we therefore propose to develop and use rV3 protein and small peptides as therapeutic agents. In preliminary studies we have been successful in producing rV3 which possesses elastogenic activity. The Aims of the project are 1) to prepare rV3 protein in enough quantity and purity to test its bioactivity in biochemical and in vitro cell-based assays and 2) to demonstrate the efficacy of rV3 to prevent intimal hyperplasia and promote elastogenesis in ex vivo cultures of human saphenous vein.