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：
10704506
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/10704506
关键词：
11 cis Retinal Adjuvant Animals Apoproteins Apoptosis Architecture BCL2 gene Binding Binding Sites Biochemical Biological Availability Blindness Cell Culture Techniques Cell Death Cell physiology Cells Cellular Stress Cessation of life Clinical Research Complex Crystallography Cytoprotection Data Development Dietary Flavonoid Disease Enhancers Equilibrium Eye diseases Flavonoids G-Protein-Coupled Receptors Gene Expression Genes Genetic Health Hybrids Impairment In Vitro Inherited Inhibition of Apoptosis 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 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 analog biophysical analysis chromophore combat design disease phenotype effective therapy effectiveness evaluation fitness high throughput screening improved in vivo inhibitor injured invention mouse model mutant mutation screening neuroprotection novel novel therapeutics pharmacologic 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.

抽象的由载脂蛋白Opsin组成的功能性视紫红质（Rho）和共价结合的11- cis-视染色体IS 正常的光转导和视力所必需的。继承的突变损害了适当的折叠，结合 Rho的11次视网膜和稳定性，导致色素性视网膜炎（RP），一种进行性退行性眼睛引起失明的疾病。目前，没有可与RP作战的治疗选择。视网膜基于的药物链酮和包括类黄酮在内的非视网膜小分子可以稳定确定体外Rho突变体。但是，RP的有效且安全的治疗尚未确定。饮食类黄酮据报道，在眼部障碍中显示出有益的作用。我们的初步研究表明普通类黄酮槲皮素可以稳定致病性RHO，改善其折叠，膜整合和视网膜结合。我们还发现槲皮素抑制了与致病性有关的应激诱导的细胞反应突变体触发Bax介导的细胞凋亡，对永久健康产生有益的后果。在这里，我们建议研究槲皮素的治疗潜力及其与残留类似物的组合以及新型的小分子BAX抑制剂可挽救RP病理学。首先，我们将评估槲皮素对 RP突变体在体外独立于遗传背景。然后，我们将评估他们恢复RP的能力 RP小鼠模型中体内表型。了解Rho的潜在分子机制槲皮素提供的突变体稳定，我们将进行结构研究，以描述槲皮素-RHO复合物通过应用晶体学和杂交质谱技术。此外，我们将通过高通量筛选来搜索更有效的化合物稳定Rho突变体类黄酮相关的化合物库，然后将使用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对特定残差类似物的调整的作用非常可容纳残留的固定口袋。其中一些退休改善了p23h的折叠致病性Rho突变体。我们将研究新的锁定视网膜和骨干的潜在纠正效果 - 修改了P23H RHO的残留类似物，并确定这些退休的结合是否可以通过槲皮素在RP中获得更大的治疗作用（AIM 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，我们将寻找由细胞应力激活的分子靶标 RP中的信号和评估是否可以调节这些细胞过程以恢复疾病表型（目标3）。首先，我们将研究槲皮素对Bax介导的细胞凋亡的影响，以了解其作用是否为与直接或间接抑制Bax或两者有关。在这些研究中，我们还将使用一种新颖的生物利用小分子抑制剂。我们将确定这种新的Bax抑制剂及其组合的有效性与槲皮素对抗RHO相关的RP。总之，这项研究所获得的知识将为通往设计有效的疗法，以防止或减慢RP病理。