Redox-sensitive activation of REDD1 in diabetic retinopathy

糖尿病视网膜病变中 REDD1 的氧化还原敏感激活

• 批准号: 10275722
• 负责人: Michael D. Dennis
• 金额: $ 47.28万
• 依托单位: PENNSYLVANIA STATE UNIV HERSHEY MED CTR
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-30 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10275722
• 关键词: Acute-Phase Proteins; Address; Antioxidants; Autophagocytosis; Basic Science; Biochemical; Blindness; Cell Surface Receptors; Complex; Complication; DNA Binding; DNA Damage; Development; Diabetes Mellitus; Diabetic Retinopathy; Diabetic mouse; Early Intervention; Environment; Event; Exclusion; Gene Chips; Glycogen Synthase Kinase 3; Impairment; Inflammation; Inflammatory; Inflammatory Response; Innovative Therapy; Insulin-Dependent Diabetes Mellitus; Intervention; Knockout Mice; Knowledge; Laboratories; Lead; Mediating; Messenger RNA; Molecular; Molecular Chaperones; Molecular Target; Mutation; NF-kappa B; Non-Insulin-Dependent Diabetes Mellitus; Nuclear; Oxidation-Reduction; Oxidative Stress; Pathogenesis; Pathology; Patients; Pharmacology; Phosphotransferases; Play; Post-Translational Protein Processing; Pre-Clinical Model; Production; Proteins; Repression; Retina; Retinal Defect; Rodent Model; Role; S-nitro-N-acetylpenicillamine; Sampling; Signal Pathway; Small Interfering RNA; Stimulus; TXNIP gene; Therapeutic; Transcriptional Activation; Transducin; Vascular Permeabilities; Vision; Visual; Visual impairment; biological adaptation to stress; chemokine; combat; cytokine; design; diabetic; diabetic patient; disulfide bond; gene product; improved; in vivo; inhibitor/antagonist; insight; macular edema; novel; nuclear factor-erythroid 2; oxidation; pre-clinical; prevent; protein degradation; protein expression; response; role model; targeted treatment; therapeutic target; transcription factor; ubiquitin ligase; visual dysfunction

Project Summary Diabetic retinopathy (DR) is a leading cause of vision loss, yet much remains unknown regarding the molecular events that cause this pervasive complication. Diabetes promotes expression of the stress response protein regulated in development and DNA damage 1 (REDD1) in the retina, which has been implicated in visual deficits in both preclinical models and diabetic patients. REDD1 protein expression is increased in the retina of rodent models of type 1 and type 2 diabetes, and REDD1 deletion prevents the development of diabetes-induced retinal pathology and functional deficits in vision. Intravitreal administration of a siRNA targeting the REDD1 mRNA has also demonstrated promise for improving visual function in patients with diabetic macular edema. Together these findings provide strong support that REDD1 plays an important role in the functional deficits in vision that are caused by diabetes. The objective here is to address two critical unresolved basic research questions related to the role of REDD1 in DR. The proposed studies will investigate why retinal REDD1 protein expression is increased by diabetes. We will also explore the molecular events downstream of REDD1 to determine how it contributes to visual impairment. The rationale is that an understanding of the molecular events that lead to increased REDD1 protein content, as well as those that are responsible for its deleterious effects on vision, may identify molecular targets for improved therapeutic strategies that provide interventions early in the preclinical and non-proliferative stages of DR. The central hypothesis is that diabetes suppresses REDD1 protein degradation in the retina to promote oxidative stress, inflammation, and subsequent retinal pathology. Aim 1 will investigate a molecular switch in the REDD1 protein that is potentially activated by diabetes, leading to reduced REDD1 degradation. The proposed studies will use in vivo SNAP-tagging to define the biochemical events that regulate REDD1 degradation in the retina of diabetic mice. Aim 2 will build on recent evidence from our laboratory supporting that REDD1 acts as a dominant governor of the nuclear factor erythroid-2-related factor 2 (Nrf2) antioxidant response. We predict that diabetes prevents a proper antioxidant response in the retina by promoting Nrf2 nuclear exclusion via REDD1-dependent activation of glycogen synthase kinase 3 (GSK3). Aim 3 will investigate a role for REDD1 in retinal inflammation, as REDD1 was recently shown to promote atypical activation of nuclear factor kappa B (NF-κB) by directly interacting with and sequestering inhibitor of κB (IκB). It is well established that oxidative stress and inflammation are crucial factors in the development and progression of the complications that cause visual impairment. The proposed studies are designed to identify and characterize specific molecular events that contribute to the development of retinal oxidative stress and inflammation in type 1 and type 2 diabetes by addressing key knowledge gaps related to a cutting-edge therapeutic target. To do so, we will explore the entirely novel concept that non-enzymatic post-translational modification of the REDD1 protein is a shared mechanism for improper activation of Nrf2 and NF-κB in DR.

项目概要 糖尿病视网膜病变 (DR) 是视力丧失的主要原因，但关于其分子机制仍有许多未知之处。 导致这种普遍并发症的事件。糖尿病促进应激反应蛋白的表达 在视网膜的发育和 DNA 损伤 1 (REDD1) 中受到调节，该损伤与视力缺陷有关 在临床前模型和糖尿病患者中。啮齿动物视网膜中 REDD1 蛋白表达增加 1 型和 2 型糖尿病模型，REDD1 缺失可预防糖尿病引起的视网膜发育 视力的病理和功能缺陷。玻璃体内注射靶向 REDD1 mRNA 的 siRNA 还显示出改善糖尿病黄斑水肿患者视觉功能的前景。一起这些 研究结果有力地证明了 REDD1 在视觉功能缺陷中发挥着重要作用 糖尿病引起的。这里的目标是解决两个关键的未解决的基础研究问题： REDD1 在 DR 中的作用。拟议的研究将调查为什么视网膜 REDD1 蛋白表达 因糖尿病而增加。我们还将探索 REDD1 下游的分子事件，以确定它如何 导致视力障碍。基本原理是对导致的分子事件的理解 REDD1 蛋白含量的增加以及那些对视力产生有害影响的蛋白可能 确定改进治疗策略的分子靶标，在临床前早期提供干预措施 DR的非增殖期和非增殖期。中心假设是糖尿病抑制 REDD1 蛋白 视网膜退化，促进氧化应激、炎症和随后的视网膜病理。目标1将 研究 REDD1 蛋白中的一个分子开关，该开关可能被糖尿病激活，从而减少 REDD1 降解。拟议的研究将使用体内 SNAP 标签来定义生化事件 调节糖尿病小鼠视网膜中 REDD1 的降解。目标 2 将建立在我们实验室的最新证据之上 支持 REDD1 作为核因子 erythroid-2 相关因子 2 (Nrf2) 的主导调控者 抗氧化反应。我们预测糖尿病会通过促进视网膜中的抗氧化反应来阻止适当的抗氧化反应 Nrf2 通过 REDD1 依赖性糖原合酶激酶 3 (GSK3) 激活进行核排除。目标3将 研究 REDD1 在视网膜炎症中的作用，因为 REDD1 最近被证明可以促进非典型激活 通过直接与 κB (IκB) 抑制剂相互作用并隔离核因子 κ B (NF-κB)。很好 确定氧化应激和炎症是疾病发生和进展的关键因素 导致视力障碍的并发症。拟议的研究旨在识别和表征 导致视网膜氧化应激和炎症发展的特定分子事件 通过解决与前沿治疗目标相关的关键知识差距，研究 1 型和 2 型糖尿病。为此， 我们将探索一个全新的概念，即 REDD1 的非酶促翻译后修饰 蛋白是 DR 中 Nrf2 和 NF-κB 不当激活的共同机制。