Treating Endothelial Dysfunction with Targeted Nanoparticle-based BH4 Delivery

描述(申请人提供)：我们的长期目标是了解内皮功能障碍的细胞和分子机制，以便阐明药物干预的新靶点，以预防和/或减少疾病的血管并发症。针对疾病损害的特定血管的基因或药物靶向为逆转这种损害和预防这些血管并发症提供了治疗希望。我们将合成纳米颗粒来传递四氢生物蝶呤(BH4)，四氢生物蝶呤(BH4)是内皮型一氧化氮合酶(NO)的关键辅助因子，以逆转或延缓糖尿病患者的内皮细胞功能障碍。糖尿病患者缺乏BH4会阻止NO的合成，并刺激血管中的氧化损伤，导致内皮功能障碍。BH4缺乏可能是许多其他疾病(例如，高胆固醇血症、高血压、与长期吸烟有关的心血管疾病)的血管功能障碍的共同基础。该R21的目标是开发可生物降解的纳米颗粒，以特异性靶向功能受损的内皮细胞，并增加BH4合成NO的利用率。提出了两个特定的目标：(1)通过可生物降解的纳米颗粒介导的BH4递送，证实BH4在体内培养的大鼠内皮细胞、分离的血管节段和血管中调节BH4和NO的生物利用度；(2)通过利用LOX-1抗体结合的纳米颗粒治疗特定的细胞/血管靶点，验证BH4靶向递送到特定内皮细胞的概念。将使用I型和II型糖尿病的动物模型。这是纳米颗粒的一种新用途，因为目前大多数纳米颗粒介导的疾病治疗方法都涉及到递送药物和/或基因，这些药物和/或基因将导致供应这些肿瘤的肿瘤细胞或血管的死亡。我们的创新方法包括给功能失调的内皮细胞带来一种有益的物质，以逆转疾病对这些细胞的影响，恢复血管功能。建议的纳米粒子还将改进基于病毒的基因治疗，因为纳米粒子可以在几天或几周内释放包封剂(包括基因和药物)。重要的是，氧化损伤的内皮细胞中BH4水平的上调不仅可以逆转疾病造成的功能障碍，还可以通过增加细胞内源性抗氧化剂来保护细胞免受未来的损伤/功能障碍。我们预计，这些可生物降解的纳米颗粒将为美国和世界各地与各种疾病相关的血管损伤人数惊人的个人提供一种多功能的预防和治疗干预。 公共卫生相关性：糖尿病患者除了无法调节血糖外，还有许多健康问题。最严重的问题之一是血管疾病。我们将开发专门针对功能受损的血管细胞的微观颗粒(即纳米颗粒)，并带来修复功能并提供未来保护免受疾病诱导的损害的试剂。我们的研究结果将为潜在的干预措施提供洞察力，这些干预措施可以改善糖尿病患者的生活，并将与这种疾病相关的心血管并发症降至最低。

DESCRIPTION (provided by applicant): Our long-range goal is to understand the cellular and molecular mechanisms of endothelial dysfunction in order to elucidate new targets for pharmacological intervention that will prevent and/or minimize vascular complications of disease. Targeting genes or drugs to specific vessels damaged by disease offers therapeutic promise for reversing that damage and preventing these vascular complications. We will synthesize nanoparticles to deliver tetrahydrobiopterin (BH4), a critical cofactor for endothelial nitric oxide (NO) synthase, to reverse or retard endothelial cell dysfunction in diabetes. A BH4 deficiency in diabetes prevents synthesis of NO and stimulates oxidative injury in blood vessels, leading to endothelial dysfunction. BH4 deficiency may be a common basis for vascular dysfunction in many other diseases (e.g., hypercholesterolemia, hypertension, cardiovascular disease associated with chronic cigarette smoking). The objective of this R21 is to develop biodegradable nanoparticles to specifically target endothelial cells exhibiting impaired function and increase availability of BH4 for NO synthesis. Two specific aims are proposed: (1) Demonstrate modulation of BH4 and NO bioavailability in cultured rat endothelial cells, isolated vessel segments, and blood vessels in vivo by biodegradable nanoparticle-mediated BH4 delivery, and (2) Validate the concept of targeted BH4 delivery to specific endothelial cells by utilizing Lox-1 antibody-conjugated nanoparticles to treat specific cell/vessel targets. Animal models of both type I and type II diabetes will be utilized. This is a novel use of nanoparticles, as most current approaches to nanoparticle-mediated disease treatment involve delivery of agents and/or genes that will bring about death of tumors cells or blood vessels feeding those tumors. Our innovative approach involves bringing a beneficial agent to dysfunctional endothelial cells in order to reverse the effects of disease on those cells and restore vascular function. The proposed nanoparticles will also improve upon viral- based gene therapy because nanoparticles can release encapsulated agents (both genes AND drugs) over a period of days or weeks. Importantly, upregulation of BH4 levels in oxidatively damaged endothelial cells will not only reverse the dysfunction caused by disease but will protect cells from future damage/dysfunction by increasing their endogenous pool of antioxidants. We expect that these biodegradable nanoparticles will provide a versatile preventative and therapeutic intervention for the alarming number of individuals in the United States and worldwide who have vascular impairment associated with a myriad of diseases. PUBLIC HEALTH RELEVANCE: People with diabetes have many health problems in addition to their inability to regulate blood sugar. One of the most serious problems is vascular disease. We will develop microscopic particles (i.e. nanoparticles) that will specifically target vascular cells exhibiting impaired function and bring agents that will repair function and provide future protection from disease-induced damage. Results of our studies will provide insight into potential interventions that can improve life for people with diabetes and minimize the cardiovascular complications associated with this disease.