Integrated Strategies for Novel Treatment of Myocardial Ischemia

描述（由申请人提供）：冠状动脉疾病（CAD）是美国发病率和死亡率的第一大原因。尽管医学治疗取得了进步，但一些患者仍然出现难治性症状，需要更积极的措施，如左心室辅助装置（LVAD）或原位心脏移植（OHT）。在过去的十年中，重组DNA技术的显著进步使CAD的分子和细胞治疗的发展成为可能。特别是，心脏基因治疗领域已经从体外研究发展到临床前试验，再到多中心试验。然而，最近的II/III期试验发现了一些问题，如在控制腺病毒载体的免疫原性、靶向表达到心脏组织以及重组基因递送后的体内监测等方面存在困难。因此，新型非病毒载体的发展是安全的，可以产生靶向组织递送将是一个重大的进步。另一个重要的进步将是评估基因表达的非侵入性技术的发展，为整个研究领域提供新的催化剂。本研究的目的是：(1)开发非免疫原性的“迷你环”DNA载体，以显著提高心脏转染效率；(2)利用遗传和分子检测的综合策略了解基因治疗的机制；(3)在临床前大型动物模型中评估安全性和有效性。在5年后，我们希望将这些发现转化为将来以微环为基础的基因疗法治疗CAD患者。

DESCRIPTION (provided by applicant): Coronary artery disease (CAD) is the number one cause of morbidity and mortality in the United States. Despite advances in medical therapies, some patients continue to develop refractory symptoms requiring more aggressive measures such as left ventricular assist device (LVAD) or orthotopic heart transplantation (OHT). Over the past decade, remarkable progress in recombinant DNA technology has enabled the development of molecular and cellular treatments for CAD. In particular, the field of cardiac gene therapy has evolved from in vitro studies to pre-clinical testing to multi-center trials. However, recent phase II/III trials have uncovered problems such as difficulties in controlling immunogenicity of adenoviral vectors, targeting expression to cardiac tissues, and in vivo monitoring of recombinant genes post delivery. Thus, the development of novel non-viral vectors that are safe and can yield targeted tissue delivery would be a major advance. Another significant advance will be the development of noninvasive techniques to assess gene expression, providing a new catalyst for the entire field of investigation. The aims of this proposal are to (1) develop non- immunogenic "minicircle" DNA vectors will significantly improve transfection efficiency in the heart, (2) understand the mechanisms of gene based therapy using integrated strategies of genetic and molecular assays, and (3) to evaluate the safety and efficacy in pre-clinical large animal models. At the end of 5 years, we hope to translate these findings to treatment of CAD patients with minicircle- based gene therapy in the future. PUBLIC HEALTH RELEVANCE: Progress in the field of cardiac gene therapy has been hindered by the lack of suitable delivery vectors. Our proposal uses a custom designed minicircles, which are supercoiled recombinant DNA molecules that can contain any transgene of interest. These minicircles have neither an origin or replication nor an antibiotic selection marker (thus minimizing immune response) and are of smaller size (thus facilitating gene transfer). We will improve its target specificity by incorporating a cardiac tissue specific promoter. Therapeutic angiogenesis will be achieved via a mutant hypoxia inducible factor (HIF-1a) transcriptional factor that is resistant to degradation and has exceptionally long half-life. Mechanisms of gene therapy will be evaluated using an integrative approach combining genetic and molecular approaches. Finally, the application of non-invasive imaging modalities in small and large animal models will help validate and translate gene therapy protocols in the clinical arena.