Regulation of vitamin A metabolism in the eye

摘要： 在健康的眼睛中，适当的维生素A(全反式视黄醇，atROL)的动态平衡在 各种照明条件。然而，某些环境侮辱加上不利的 遗传背景可以克服眼部视黄醇代谢的适应能力和妥协 视网膜功能。临床上的例子是Stargardt病，一种遗传性青少年黄斑 变性和老年性黄斑变性(AMD)，其中视黄醇代谢失衡 一个重要的病因。尽管进行了密集的研究，FDA还是批准了对遗传性或获得性的治疗 退行性视网膜疾病非常有限。在这个项目中，我们建议扩大潜在的治疗选择 通过开发一种安全有效的方法来控制视网膜退行性疾病的眼流量 维甲酸通过靶向维生素A结合蛋白。以洞察其潜在的治疗应用 这种方法，我们建议进行综合研究，结合不同的生化，生物物理和 旨在开发候选药物并评估其动物生物学效应的生理学方法 人类视网膜退行性疾病的模型。 为了实现这些目标，我们提出了三个具体目标。在目标1中，我们将利用高通量筛选 (HTS)技术鉴定细胞视黄醇结合蛋白(CRBP1)的小分子拮抗剂。我们会 选择先导化合物并表征其结合性能。我们还将验证它们的生物活性 一种基于细胞的二次化验。最终，我们将预先选择一流的候选药物，以允许 维甲酸代谢的药物操作。在目标2中，CRBP1配体的治疗潜力将 通过评估体内视网膜的生化和病理生理过程的变化来进行评估。 实验性治疗的结果将通过视网膜电图仪、非侵入性成像进行监测。 技术，包括光学相干断层扫描、扫描激光眼底镜和双光子 眼部的视黄醇代谢将用先进的分析工具进行检查。最终， 我们将CRBP1拮抗剂的生化特性与其治疗效果联系起来，从而提供 可靠的概念验证数据，可进一步发展为初步临床试验。在目标3中，我们将结合 非维A酸类配体与CRBP1相互作用方式的结构信息及研究方法 药物化学，合理提高候选药物的药效学性质。我们还将 根据所选候选药物的跨境能力确定其药代动力学 血/视网膜屏障。这些实验的完成将确定提供 先导化合物的最佳功效配置。 我们的研究将共同为失明眼部疾病提供一种新的基于机制的治疗策略。 一流的候选药物在体内进行了预先测试，将扩大数百万患者的治疗选择 受视网膜退行性疾病的影响。

ABSTRACT: In a healthy eye, the proper homeostasis of vitamin A (all-trans-retinol, atROL) supports visual function under a variety of lighting conditions. However, certain environmental insults in combination with an unfavorable genetic background can overcome the adaptive capabilities of ocular retinoid metabolism and compromise retinal function. The clinical examples are Stargardt disease, an inherited form of juvenile macular degeneration and Age-related macular degeneration (AMD), in which an imbalance in retinoid metabolism is an important etiologic factor. Despite intensive studies, FDA approved treatments for inherited or acquired degenerative retinal diseases are very limited. In this project, we propose to expand potential treatment options for the retinal degenerative diseases by developing a safe and effective method of controlling the ocular flux of retinoids by targeting vitamin A binding proteins. To obtain insight into the potential therapeutic applications of this approach, we propose comprehensive studies that combine diverse biochemical, biophysical, and physiological methods aimed at developing candidate drugs and assessing their biological effects in animal models of human retinal degenerative diseases. To achieve these goals, we propose three specific aims. In Aim 1, we will utilize high-throughput screening (HTS) technology to identify small-molecule antagonists of cellular retinol-binding protein (CRBP1). We will select lead compounds and characterize their binding properties. We will also validate their biological activity in a cell-based secondary assay. Ultimately, we will pre-select the first-in-class drug candidates that allow for the pharmaceutical manipulation of retinoid metabolism. In Aim 2, the therapeutic potential of CRBP1 ligands will be assessed by evaluating changes in biochemical and pathophysiological processes in the retinas in vivo. The results of experimental therapies will be monitored by electroretinograms, non-invasive imaging techniques, including optical coherence tomography, scanning laser ophthalmoscopy, and two-photon microscopy, whereas ocular retinoid metabolism will be examined with advanced analytical tools. Ultimately, we will link the biochemical properties of CRBP1 antagonists with their therapeutic effects, and thus provide solid proof-of-concept data that could be further developed into initial clinical trials. In Aim 3, we will combine the structural information about the mode of non-retinoid ligands interaction with CRBP1 and methods of medicinal chemistry to rationally improve pharmacodynamic properties of drug candidates. We will also determine pharmacokinetics of the selected drug candidates in the context of their ability to cross the blood/retina barrier. The completion of these experiments will identify the chemical properties that provide the best efficacy profile for the lead compounds. Together, our studies will contribute a novel mechanism-based therapeutic strategy for blinding eye conditions and first-in-class drug candidates pre-tested in vivo that will expand treatment options for millions of patients affected by retinal degenerative diseases.