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）疾病是一组临床和遗传多样的视网膜变性疾病。 营养不良包括Leber先天性黑蒙（LCA）和常染色体显性视网膜色素变性（ADRP）。 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，但细胞凋亡仍然是一个重要的问题。 遗传性视力丧失的机制需要进一步研究，有效的治疗方法仍然存在。 正在开发中。因此，我们集中研究税务局的机制，以及 治疗策略特别是，我们解决的作用，翻译衰减的视网膜发病机制， 小鼠模拟人ADRP和LCA，并提出基于蛋白质修复的治疗方法 受影响的光感受器中的合成。该建议得到了我们的科学家们所创造的强有力的科学前提的支持。 已发表的和初步的数据，以及其他人的作品。他们认为有IRD经历的老鼠 未折叠蛋白反应（UPR）的持续激活和视网膜中的翻译衰减。在 此外，我们的初步数据表明，PERK（蛋白激酶R [PKR]样内质网激酶） UPR臂负责应激光感受器中的持续翻译抑制。为了支持这一点， 我们将研究三个PERK诱导的靶点，它们独立调节翻译的共识工作 机械.首先，我们计划评估平移衰减对视网膜变性的影响， 磷酸化eIF 2a，翻译阻断的主要标志。其次，我们计划评估TRB 3在以下方面的作用： 通过改变其表达，从而测试TRB 3在IRD期间增加的假设， IRD进展是细胞毒性的，而其下调增强蛋白质合成并延缓IRD进展。 最后，我们计划检验通过失活来稳定5 '帽mRNA识别复合物的假设， 真核生物起始因子4 E（4 E-BP）是一种负性翻译调节因子，它通过以下途径减缓IRD的发生： 增加蛋白质合成。表达改变的UPR和mRNA水平的转基因小鼠 预防相关标志物;小鼠模拟人IRD;改变UPR水平的药理学方法 标记物;和腺相关病毒基因递送将用于研究中以调节蛋白质合成， 探索治疗方法。据我们所知，这是第一次全面研究翻译 调节健康和患病的光感受器。如果成功，这项研究将不仅提高我们的 从分子水平了解退化的PR如何死亡，同时也为治疗干预创造了平台 来阻止IRD在人类中的发展。PERK通路靶向治疗可以作为一种突变- 对于经历慢性ER应激的视网膜的独立治疗或作为补充策略， 加强现有的基因替代方法。它们对突变特别有吸引力， 大的基因，不能使用常规的AAV介导的基因疗法治疗。