Novel neuroprotective activities of flavonoids against retinal degenerative diseases

黄酮类化合物对视网膜退行性疾病的新型神经保护活性

基本信息

批准号：
10428740
负责人：
Beata Jastrzebska
金额：
$ 46.69万
依托单位：
CASE WESTERN RESERVE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-09-30 至 2026-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10428740
关键词：
11 cis Retinal Adjuvant Animals Apoproteins Apoptosis Architecture BCL2 gene Binding Binding Sites Biochemical Blindness Cell Culture Techniques Cell Death Cell physiology Cells Cellular Stress Cellular Stress Response Cessation of life Clinical Research Complex Crystallography Data Development Dietary Flavonoid Disease Enhancers Equilibrium Eye diseases Flavonoids G-Protein-Coupled Receptors Gene Expression Genes Genetic Health Hybrids Impairment In Vitro Inherited Knock-in Knock-out Knowledge Learning Libraries Light Link Mass Spectrum Analysis Mediating Membrane Modeling Molecular Molecular Chaperones Molecular Target Morphology Mus Mutation Natural regeneration Opsin Pathogenicity Pathologic Pathology Patients Pharmacology Phenotype Photoreceptors Phototransduction Quercetin Reporting Research Personnel Retina Retinal Degeneration Retinal Diseases Retinitis Pigmentosa Rhodopsin Role Signal Transduction Stress Techniques Testing Therapeutic Therapeutic Effect Transcriptional Regulation Variant Vertebral column Vision Visual system structure analog base biophysical analysis chromophore combat design disease phenotype effective therapy effectiveness evaluation fitness high throughput screening improved in vivo inhibitor injured mouse model mutant mutation screening neuroprotection novel novel therapeutics photoreceptor degeneration prevent response small molecule small molecule inhibitor therapeutically effective trafficking treatment effect

项目摘要

ABSTRACT Functional rhodopsin (Rho) composed of apoprotein opsin and covalently bound 11-cis-retinal chromophore is required for normal phototransduction and vision. Inherited mutations compromise proper folding, binding of 11-cis-retinal, and stability of Rho, leading to retinitis pigmentosa (RP), a progressive degenerative eye disease that causes blindness. Currently, there are no treatment options available to combat RP. Retinal- based pharmacological chaperones and non-retinal small molecules, including flavonoids, can stabilize certain Rho mutants in vitro. However, effective and safe therapy for RP has yet to be established. Dietary flavonoids have been reported to show beneficial effects in ocular impairments. Our preliminary studies showed that common flavonoid quercetin could stabilize pathogenic Rho, improve its folding, membrane integration, and retinal binding. We also found that quercetin inhibits stress-induced cellular responses related to pathogenic mutants triggering Bax-mediated apoptosis with beneficial consequences to retinal health. Here we propose to study, the therapeutic potential of quercetin and its combinations with retinal analogs, and novel small molecule Bax inhibitor to rescue RP pathology. First, we will evaluate quercetin positive effects on RP mutants independently of the genetic background in vitro. Then, we will assess their ability to revert the RP phenotype in vivo in mouse models of RP. To understand the underlying molecular mechanism of Rho mutant’s stabilization offered by quercetin we will perform structural studies to delineate the architecture of quercetin-Rho complexes by applying crystallographic and hybrid mass-spectrometry techniques. In addition, we will search for more effective compounds stabilizing Rho mutants by high-throughput screening of flavonoid-related compound libraries, which then will be validated with systematic biochemical and biophysical analyses (Aim 1). Second, we will examine the role of quercetin as an adjuvant for the specific retinal analogs stably accommodating the retinal-binding pocket. Some of these retinals improve the folding of the P23H pathogenic Rho mutant. We will examine the potential corrective effect of new locked retinal and backbone- modified retinal analogs for P23H Rho and determine if the binding of these retinals could be enhanced by quercetin to gain a greater therapeutic effect in RP (Aim 2). Third, we will study the cellular processes in RP. To gain a better understanding of RP pathology we will look for molecular targets activated by cellular stress signals in RP and assess if quercetin can modulate these cellular processes to revert the disease phenotype (Aim 3). At first, we will examine the effect of quercetin on Bax-mediated apoptosis to learn if its effect is related to direct or indirect inhibition of Bax, or both. In these studies, we will also use a novel bioavailable small molecule Bax inhibitor. We will determine the effectiveness of this new Bax inhibitor and its combination with quercetin against Rho-related RP. Altogether, the knowledge gained from this study will pave the way to design an effective therapeutic remedy to prevent or slow down RP pathology.

抽象的功能性视紫红质 (Rho) 由脱辅基蛋白视蛋白和共价结合的 11-顺式视网膜发色团组成正常光转导和视觉所需的遗传突变会损害正确的折叠、结合。 11-顺式视网膜和 Rho 的稳定性，导致色素性视网膜炎 (RP)，一种进行性眼睛退化目前，没有可用于对抗 RP 的治疗方案。基于药理伴侣和非视网膜小分子，包括类黄酮，可以稳定某些体外 Rho 突变体然而，尚未建立有效且安全的 RP 治疗方法。据报道，我们的初步研究表明，对眼部损伤有有益的作用。常见的黄酮类槲皮素可以稳定致病性 Rho，改善其折叠、膜整合和我们还发现槲皮素抑制与致病相关的应激诱导的细胞反应。突变体触发 Bax 介导的细胞凋亡，对视网膜健康产生有益的影响。在这里，我们建议研究槲皮素及其与视网膜类似物的组合的治疗潜力，以及新型小分子 Bax 抑制剂可挽救 RP 病理学首先，我们将评估槲皮素对 RP 病理的积极作用。然后，我们将评估它们恢复 RP 的能力。 RP 小鼠模型体内表型了解 Rho 的潜在分子机制。槲皮素提供突变体的稳定性，我们将进行结构研究来描述其结构通过应用晶体学和混合质谱技术形成槲皮素-Rho 复合物。我们将通过高通量筛选来寻找更有效的稳定Rho突变体的化合物类黄酮相关化合物库，然后将通过系统的生化和生物物理验证分析（目标 1）其次，我们将研究槲皮素作为特定视网膜类似物的佐剂的作用。稳定地容纳视网膜结合袋，其中一些视网膜改善了 P23H 的折叠。我们将检查新的锁定视网膜和骨干的潜在纠正作用。修饰 P23H Rho 的视网膜类似物，并确定这些视网膜的结合是否可以通过以下方式增强：槲皮素在 RP 中获得更大的治疗效果（目标 2）第三，我们将研究 RP 中的细胞过程。为了更好地了解 RP 病理学，我们将寻找由细胞应激激活的分子靶标 RP 中的信号并评估槲皮素是否可以调节这些细胞过程以恢复疾病表型（目标 3）首先，我们将检查槲皮素对 Bax 介导的细胞凋亡的影响，以了解其作用是否有效。与 Bax 的直接或间接抑制相关，或两者兼而有之。在这些研究中，我们还将使用一种新型的生物利用度。我们将确定这种新型 Bax 抑制剂及其组合的有效性。总而言之，从这项研究中获得的知识将为以下方面铺平道路：设计一种有效的治疗方法来预防或减缓 RP 病理。