Treating Endothelial Dysfunction with Targeted Nanoparticle-based BH4 Delivery

描述（由申请人提供）：我们的长期目标是了解内皮功能障碍的细胞和分子机制，以阐明药物干预的新靶点，以预防和/或减少血管并发症。将基因或药物靶向于被疾病损伤的特定血管，为逆转这种损伤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递送四氢生物蝶呤（BH4），一种内皮一氧化氮（NO）合成酶的关键辅助因子，以逆转或延缓糖尿病内皮细胞功能障碍。糖尿病患者缺乏BH4，阻止NO合成，刺激血管氧化损伤，导致内皮功能障碍。BH4缺乏可能是许多其他疾病（如高胆固醇血症、高血压、与慢性吸烟相关的心血管疾病）中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，专门针对内皮细胞表现出功能受损，并增加BH4合成NO的可用性。提出了两个具体目标：(1)通过可生物降解纳米颗粒介导的BH4递送，证明BH4和NO在培养大鼠内皮细胞、分离血管段和体内血管中的生物利用度的调节；(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涉及递送药物和/或基因，这些药物和/或基因将导致肿瘤细胞或为这些肿瘤提供营养的血管死亡。我们的创新方法包括给功能失调的内皮细胞带来有益的药物，以逆转疾病对这些细胞的影响，恢复血管功能。所提出的纳米颗粒也将改进基于病毒的基因治疗，因为纳米颗粒可以在几天或几周内释放封装的药物（基因和药物）。重要的是，氧化损伤内皮细胞中BH4水平的上调不仅可以逆转疾病引起的功能障碍，还可以通过增加内源性抗氧化剂来保护细胞免受未来的损伤/功能障碍。我们期望这些可生物降解的纳米颗粒将为美国和世界范围内数量惊人的与各种疾病相关的血管损伤患者提供多用途的预防和治疗干预。

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.