Novel Peptide/siRNA Nanoparticles for Treatment of Acute Lung Injury

项目总结/摘要 急性肺损伤（ALI）及其更严重的形式急性呼吸窘迫综合征（ARDS）是一种严重的肺损伤。 危重病人呼吸衰竭的常见原因。目前所有针对ALI/ARDS的疗法都依赖于 支持性护理以改善临床结果。没有开发出有效的药物。迫切需要 开发新的安全、有效的ALI/ARDS治疗策略，并基于对ALI/ARDS的深入了解， ALI发病机制的研究进展。我们已经发现，MTOR在 与ALI相关炎症和肺上皮细胞中MTOR的下调有可能 缓解这种炎症。然而，肺内皮细胞中MTOR的下调具有相反的作用。 并加剧炎症。因此，为了将这些发现转化为潜在的治疗方法，我们必须减少 MTOR水平和活性选择性地在肺上皮中。我们最近还报道了 二硫键限制的环状两亲肽（CAPS），其结合siRNA以形成纳米复合物， 在功能上影响siRNA货物向肺的细胞内递送以进行蛋白质沉默。我们假设 CAP-siRNA纳米颗粒是一种理想的载体，可选择性地将siRNA递送至肺上皮细胞， 简单的愿望。该提案的总体目标是表征细胞内siRNA的机制， 通过CAP-siRNA纳米颗粒的递送，并通过这些颗粒优化MTOR沉默，以验证 它们作为ALI的药物治疗的应用。我们将利用跨学科的战略， 实现既定的研究目标。该提案的具体目的是：1）描述 我们最近报道的CAP用于siRNA细胞内递送的易位机制。2)进行 结构-活性研究，以优化CAP的细胞内siRNA递送和基因沉默的效率- siRNA纳米复合物。3)验证CAP-siRNA纳米颗粒用于选择性敲低MTOR的用途 在ALI的体内模型中的肺上皮细胞中。拟议中的工作需要在物理和 和生物科学。该研究小组利用肽设计，肺生物学和基因方面的专业知识， 疗法拟议的工作将扩大尼尔森，院长和 拉赫曼集团。实现既定的研究目标将解决在理解方面的重大差距， 目的：探讨急性肺损伤的病因，验证下调MTOR治疗急性肺损伤的有效性，为临床治疗急性肺损伤提供理论依据。 肽/siRNA纳米颗粒，其促进MTOR特异性siRNA向肺的体内递送。此夕h 提出的CAP试剂代表了一类新的创新的细胞穿透肽基序， 其生产便宜并且不需要共价连接货物以促进细胞进入。是 预期所提出的CAP-siRNA纳米颗粒也可用于其他肺肿瘤的基因沉默。 作为一种平台技术，它可以靶向一系列疾病以及其他组织。

Project Summary/Abstract Acute Lung Injury (ALI) and its more severe form Acute Respiratory Distress Syndrome (ARDS) are a common cause of respiratory failure in critically ill patients. All current therapies for ALI/ARDS rely on supportive care to improve clinical outcome. No effective drugs have been developed. There is an urgent need to develop new treatment strategies for ALI/ARDS that are safe, effective, and based on deeper understanding of the mechanisms involved in ALI pathogenesis. We have discovered that MTOR plays a key role in the inflammation associated with ALI and that downregulation of MTOR in lung epithelial cells has the potential to alleviate this inflammation. However, downregulation of MTOR in lung endothelial cells has the opposite effect and exacerbates inflammation. Thus, to translate these findings into a potential treatment, we must reduce MTOR levels and activity selectively in the lung epithelium. We have also recently reported the discovery of disulfide-constrained, cyclic amphipathic peptides (CAPS) that bind to siRNA to form nanocomplexes that can functionally affect intracellular delivery of siRNA cargo to the lung for protein silencing. We hypothesize that CAP-siRNA nanoparticles represent an ideal vector for selective delivery of siRNA to lung epithelial cells by simple aspiration. The overall objective of this proposal is to characterize the mechanism of intracellular siRNA delivery by CAP-siRNA nanoparticles and to optimize MTOR silencing by these particles toward validation of their application as a pharmacologic treatment for ALI. We will utilize a cross-disciplinary strategy to accomplish the stated research objective. The Specific Aims of the proposal are: 1) To characterize the mechanism of translocation for intracellular delivery of siRNA by our recently reported CAPs. 2) To conduct structure-activity studies to optimize the efficiency of intracellular siRNA delivery and gene silencing by CAP- siRNA nanocomplexes. 3) To validate the use of CAP-siRNA nanoparticles for selective knockdown of MTOR in lung epithelial cells in an in vivo model for ALI. The proposed work requires expertise in both the physical and biological sciences. The research team draws on expertise in peptide design, lung biology, and gene therapy. The proposed work will extend existing collaborative relationships between the Nilsson, Dean, and Rahman groups. Accomplishment of the stated research goal will address significant gaps in understanding of the disease etiology of ALI, validate the efficacy of MTOR downregulation for treatment of ALI, and provide peptide/siRNA nanoparticles that facilitate in vivo delivery of MTOR-specific siRNA to the lung. Further, the proposed CAP agents represent a new class of innovative cell-penetrating peptide motif that is simple and inexpensive to produce and that does not require covalent attachment of cargo to promote cell entry. It is anticipated that the proposed CAP-siRNA nanoparticles will be also useful for gene silencing of other lung targets in a range of disorders as well as in other tissues as a platform technology.