Nanotechnology for Treatment of Diabetic Retinopathy

描述(由申请人提供)： 糖尿病视网膜病变(DR)是糖尿病的常见并发症，也是世界范围内致盲的主要原因。糖尿病黄斑水肿(DME)和视网膜新生血管(NV)是导致DR患者视力丧失的两种主要病理改变，视网膜血管内皮生长因子(VEGF)的过度表达是DR血管渗漏的主要原因。目前，还没有令人满意的治疗方法来治疗DME和视网膜NV，但可以肯定的是，迫切需要治疗。 CharLesson，LLC及其全资子公司LifeTrees，LLC是总部位于俄克拉何马城的公司，领导着治疗严重眼病的药物产品的发现和开发。该公司正在开发治疗上述疾病的第一种基于眼药水的疗法，并在过去12个月中取得了重大的商业里程碑。CharLesson最近在其执行管理团队中兼职增加了原子风险投资伙伴公司的一名创始人。AVP是一家早期风投基金，投资于制药公司，在硅谷、波士顿和俄克拉何马州设有办事处。此外，该公司与俄克拉荷马大学健康科学中心(OUHSC)建立了强大的研发合作伙伴关系，并与Dean McGee眼科研究所和OK医学研究基金会建立了关系。 据估计，新生血管、糖尿病视网膜病变和黄斑变性治疗的市场规模超过90亿美元，每年增长超过20%。糖尿病，包括糖尿病视网膜病变，正迅速成为工业化世界的流行病。大约有1820万美国人患有糖尿病，美国每年有270万新病例。所有患有糖尿病的人，无论是1型糖尿病还是2型糖尿病，都有患上糖尿病的风险。糖尿病视网膜病变是美国20至74岁成年人新增失明病例的主要原因，每年导致1.2万至2.4万新失明病例。 纤溶酶原kringle5(K5)是纤溶酶原的蛋白水解性片段。它是一种内源性血管生成抑制物。纤溶酶原含有5个kringle结构域，每个结构域由80个氨基酸组成。血管抑素由纤溶酶原的前4环(K1-4)组成。K5比血管抑素具有更强的抗血管生成活性。我们以前的研究表明，玻璃体内注射K5可以阻止氧诱导视网膜病变(OIR)和链脲佐菌素(STZ)诱导的糖尿病模型视网膜血管渗漏的发展和进展。注射K5也能有效改善OIR模型的视网膜NV。K5下调培养的视网膜M？ller细胞中的血管内皮生长因子的表达，M？ller细胞是视网膜和OIR大鼠视网膜中血管内皮生长因子的主要产生者。K5还抑制内皮细胞迁移，这是血管生成中的一个关键过程。 这一阶段项目的目标是开发一种新型的、非病毒的K5基因递送系统，该系统安全、具有强烈的组织特异性和K5在视网膜中的长期表达。巨噬细胞是血管内皮生长因子的主要产生者，而血管内皮生长因子是血管通透性和血管生成的重要介质。为了实现组织特异性表达，人类K5被构建在M？ller细胞特异性启动子的控制下，即胶质纤维酸性蛋白(GFAP)启动子。我们的初步研究表明，玻璃体内注射这些GFAP-K5纳米颗粒(GFP-K5-NP)可以减少OIR大鼠的视网膜血管渗漏，并减轻视网膜NV。该项目将扩展这些研究，确定1)GFAP-K5-NP是否介导K5在视网膜M？ller细胞的表达，2)K5的表达是否对降低STZ-糖尿病动物模型的视网膜血管内皮生长因子水平和血管渗漏有长期影响，并在OIR模型中减弱视网膜NV和减少视网膜血管渗漏。因此，在这一期项目中，我们将证明GFAP-K5-NP介导了K5的视网膜特异性表达，并对视网膜新生血管和血管渗漏具有治疗作用。这些研究将为这些非病毒疗法在第二阶段的进一步表征奠定坚实的基础。糖尿病黄斑水肿(DME)和视网膜新生血管(NV)是导致视力丧失的主要病理改变，Kringle博士5在视网膜血管泄漏和新生血管方面具有强大的抗血管生成作用。我们计划通过将纳米技术和天然血管生成抑制剂相结合，开发一种非病毒和组织特异性的基因疗法，可以减少血管渗漏和视网膜NV。这些新型纳米颗粒可能在治疗糖尿病血管并发症方面具有治疗潜力。

DESCRIPTION (provided by applicant): Diabetic retinopathy (DR) is a common complication of diabetes and a leading cause of blindness in the world. Diabetic macular edema (DME) and retinal neovascularization (NV) are the two major pathological alternations leading to vision loss in patients with DR. Over-expression of vascular endothelial growth factor (VEGF) in the retina is a major causative factor for vascular leakage in DR (2-4). Currently, there is no satisfactory therapy to treat DME and retinal NV but most certainly, a dire need exists. Charlesson, LLC and its wholly-owned subsidiary LifeTrees, LLC are Oklahoma City-based companiesthat are leading the discovery and development of drug products to treat severe eye disease. The company is developing the first eyedrop-based therapy for treatment of the aforementioned conditions, and has achieved significant commercial milestones in the past 12 months. Charlesson recently added a founder of Atomic Venture Partners to its executive management team on a part-time basis. AVP is an early-stage VC fund that invests in pharmaceutical companies and has offices in the Silicon Valley, Boston, and OKC. Additionally, the company has a strong R&D partnership with the University of Oklahoma Health Sciences Center (OUHSC), and relationships with the Dean McGee Eye Institute and the OK Medical Research Foundation. The market size for neovascularization, diabetic retinopathy, and macular degeneration treatments is estimated to be greater than $9 billion, growing in excess of 20% per year. Diabetes, including diabetic retinopathy, is quickly becoming an epidemic in the industrialized world. About 18.2 million Americans have diabetes, with 2.7 million new cases in the U.S. each year. All people with diabetes, both type 1 and type 2, are at risk to develop DR. Diabetic retinopathy is the leading cause of new cases of blindness among American adults between 20 and 74 years, causing 12,000 to 24,000 new cases of blindness each year. Plasminogen kringle 5 (K5) is a proteolytic fragment of plasminogen. It is an endogenous angiogenic inhibitor. Plasminogen contains 5 kringle domains, each consisting of 80 amino acids. Angiostatin consists of the first 4 kringles (K1-4) of plasminogen. K5 has a more potent anti-angiogenic activity than angiostatin. Our previous studies have shown that intravitreal injection of K5 prevents the development and arrests the progression of retinal vascular leakage in the oxygen-induced retinopathy (OIR) and streptozotocin (STZ)-induced diabetic models. K5 injection also effectively ameliorates the retinal NV in the OIR model. K5 down-regulates the VEGF expression in cultured retinal M¿ller cells, the major producer of VEGF in the retina and in the retina of OIR rats. K5 also inhibits endothelial cell migration, which is a critical process in angiogenesis. The goal of this phase I project is to develop a novel, non-viral K5 gene delivery system that is safe, has strong tissue specificity and long-term expression of K5 in the retina. The M¿ller cells are the major producer of VEGF which is a potent mediator of vascular permeability and angiogenesis. In order to achieve a tissue-specific expression, human K5 has been constructed under the control of a M¿ller cell-specific promoter, the glial fibrillary acidic protein (GFAP) promoter. Our preliminary study has demonstrated that the intravitreal administration of these GFAP-K5 nanoparticles (GFP-K5-NP) reduces the retinal vascular leakage and atenuates retinal NV in OIR rats. This project will extend these studies by defining 1) if GFAP-K5-NP mediates K5 expression in M¿ller cells in the retina, 2) if the K5 expression has long-term effects on reducing retinal VEGF levels and vascular leakage STZ-diabetic animal models, and attenuates retinal NV and reduces retinal vascular leakage in the OIR model. Therefore, in this phase I project, we will prove the concenpt that the GFAP-K5-NP mediates the retina-specific expression of K5 and has therapeutic effects on retinal NV and vascular leakage. These studies will lay a solid ground for the further characterization of these non-viral therapies in Phase II. Diabetic macular edema (DME) and retinal neovascularization (NV) are the major pathological alternations leading to the vision loss in DR. Kringle 5 has potent anti-angiogenic effect on retinal vascular leakge and neovascularization. We plan to develop a non-viral and tissue specific gene therapy by combining the nanotechnology and natural angiogenic inhibitors, which may attenuate vascular leakage and retinal NV. These novel nanoprticles may have the therapeutic potential in the treatment of diabetic vascular complications.