Molecular mechanisms of translational control in mice with inherited retinal degeneration

遗传性视网膜变性小鼠翻译控制的分子机制

• 批准号: 10091441
• 负责人: Marina Gorbatyuk
• 金额: $ 36.01万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-02-01 至 2023-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10091441
• 关键词: AKT inhibition; Acute; Address; Affect; Animal Model; Attenuated; Basic Science; Binding; Binding Proteins; Blindness; Cell Death; Cells; Cellular biology; Chronic; Chronic stress; Clinical; Complex; Data; Development; Disease; Down-Regulation; EIF4EBP1 gene; Endoplasmic Reticulum; Eukaryotic Initiation Factor-4E; Eukaryotic Initiation Factors; FRAP1 gene; Genes; Genetic Translation; Genetically Modified Animals; Glucose; Heat shock proteins; Homologous Gene; Human; Individual; Inherited; Investigational Therapies; Leber' s amaurosis; Literature; Mediating; Mediator of activation protein; Methods; Molecular; Molecular Target; Mus; Mutation; Pathogenesis; Pathologic; Pathway interactions; Pharmacology; Phosphorylation; Phosphotransferases; Photoreceptors; Protein Biosynthesis; Protein Kinase; Proteins; Proto-Oncogene Proteins c-akt; Publishing; Recovery; Repression; Retina; Retinal Degeneration; Retinal Diseases; Retinal Dystrophy; Retinitis Pigmentosa; Rhodopsin; Role; Signal Transduction; Sphingolipids; Stress; System; Testing; Therapeutic; Therapeutic Intervention; Time; Translational Regulation; Translations; Up-Regulation; Viral Genes; Work; arm; attenuation; base; biological adaptation to stress; cytotoxic; effective therapy; endoplasmic reticulum stress; experience; gene replacement; gene therapy; human model; improved; inherited retinal degeneration; lipid metabolism; mRNA capping; mouse model; protein kinase R; response; response biomarker; restoration; retinal rods; targeted treatment; therapeutic development; therapeutically effective; translational impact; viral gene delivery

Inherited retinal degeneration (IRD) diseases are a clinically and genetically diverse group of retinal dystrophies including Leber congenital amaurosis (LCA) and autosomal dominant retinitis pigmentosa (ADRP). Despite significant progress in the basic science and clinical aspects of many retinopathies, the cellular mechanisms responsible for inherited vision loss require further investigation, and effective therapies are still under development. Therefore, we focused on the elucidation of the IRD mechanism and the development of therapeutic strategies. In particular, we address the role of translational attenuation in retinal pathogenesis of mice-mimicking human ADRP and LCA and propose therapeutic approaches based on the restoration of protein synthesis in affected photoreceptors. The proposal is supported by strong scientific premises created by our published and preliminary data, as well as the works of others. They suggest that mice with IRD experience persistent activation of the unfolded protein response (UPR) and translational attenuation in the retinas. In addition, our preliminary data demonstrate that PERK (protein kinase R [PKR]-like endoplasmic reticulum kinase) UPR arm is responsible for the sustained translational suppression in stressed photoreceptors. To support this, we will investigate three PERK-induced targets that independently regulate the consensual work of translational machinery. First, we plan to evaluate the impact of translational attenuation on retinal degeneration provided by phosphorylated eIF2a, a major hallmark of translational block. Second, we plan to assess the role of TRB3 in retinal degeneration by modifying its expression, thereby testing the hypothesis that TRB3 increase during IRD progression is cytotoxic, while its down-regulation enhances protein synthesis and retards IRD progression. Finally, we plan to test the hypothesis that stabilization of the 5'cap mRNA recognition complex by deactivation of eukaryotic initiation factor 4E (4E-BP), a negative translational regulator slows the onset of IRD through augmentation of protein synthesis. Genetically modified mice expressing altered levels of UPR and mRNA translation-associated markers; mice-modeling human IRD; pharmacological approaches altering levels of UPR markers; and adeno-associated viral gene delivery will be used in the study to regulate protein synthesis and explore therapeutic approaches. To our knowledge, this is the first comprehensive study of translational regulation in healthy and diseased photoreceptors. If successful, this study will not only enhance our molecular understanding of how degenerating PRs die but also create a platform for therapeutic intervention to halt IRD progression in humans. PERK pathway-targeted therapies could be used as a mutation- independent treatment for retinas experiencing chronic ER stress or as a supplemental strategy to enhance pre-existing gene replacement approaches. They would be particularly attractive for mutations in large genes that cannot be treated using conventional AAV-mediated gene therapy.

遗传性视网膜变性（IRD）疾病是临床和遗传多样的视网膜 包括Leber先天性症（LCA）和常染色体显性视网膜炎色素炎（ADRP）在内的营养不良。 尽管在许多视网膜病的基础科学和临床方面取得了重大进展，但细胞仍在 负责遗传视力丧失的机制需要进一步研究，有效的疗法仍在 正在开发。因此，我们专注于阐明IRD机制和发展 治疗策略。特别是，我们解决了翻译衰减在视网膜发病机理中的作用 模仿人ADRP和LCA的小鼠并根据蛋白质的恢复提出治疗方法 受影响的光感受器的合成。该提案得到了我们的强大科学前提的支持 已发布和初步数据以及他人的作品。他们建议具有IRD经验的老鼠 视网膜中展开的蛋白质反应（UPR）和翻译衰减的持续激活。在 此外，我们的初步数据表明，PERK（蛋白激酶R [PKR]样性内质网激酶） UPR臂负责压力感光体中持续的翻译抑制。为了支持这一点， 我们将研究三个振兴诱导的目标，这些目标独立规范了转化的共识工作 机械。首先，我们计划评估翻译衰减对由 磷酸化EIF2A，转化块的主要标志。其次，我们计划评估trb3在 视网膜变性通过修饰其表达，从而测试了IRD期间TRB3增加的假设 进展为细胞毒性，而其下调则增强了蛋白质的合成并阻碍了IRD进展。 最后，我们计划检验以下假设，即停用5'CAP mRNA识别复合物的稳定 真核开始因子4E（4E-BP）的负转化调节器减慢了IRD的发作 蛋白质合成的增强。表达UPR和mRNA水平改变的转基因小鼠 与翻译相关的标记；老鼠模拟人类IRD；药理学方法改变​​UPR水平 标记；研究中将使用腺相关的病毒基因递送来调节蛋白质的合成和 探索治疗方法。据我们所知，这是翻译的首次全面研究 健康和患病感受器的调节。如果成功，这项研究不仅会增强我们的 分子对退化PR的死亡方式的理解，但也为治疗干预创造了平台 阻止人类进步。靶向PERK途径的疗法可以用作突变 - 独立治疗视网膜经历慢性ER压力或作为补充策略的独立治疗 增强先前存在的基因替代方法。它们对突变特别有吸引力 无法使用常规AAV介导的基因疗法进行治疗的大基因。