Hyperglycemia-induced translational control of gene expression in the retina

高血糖诱导的视网膜基因表达翻译控制

• 批准号: 8567775
• 负责人: Michael D. Dennis
• 金额: $ 8.51万
• 依托单位: PENNSYLVANIA STATE UNIV HERSHEY MED CTR
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2015-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8567775
• 关键词: Ablation; Accounting; Acetylglucosamine; Address; Affect; Age; American; Angiogenic Factor; Binding; Binding Proteins; Blindness; Blood Vessels; C-terminal; Complex; Data; Development; Diabetes Mellitus; Diabetic Retinopathy; Diabetic mouse; Disease; Evidence based treatment; Figs - dietary; Functional disorder; Future; Gene Expression; Gene Expression Profile; Genetic Translation; Glucose; Goals; Growth Factor; Hexosamines; Hyperglycemia; Impairment; Incidence; Individual; Innovative Therapy; Insulin; Internal Ribosome Entry Site; Intervention; Laboratories; Lasers; Lead; Link; Mediating; Mentors; Messenger RNA; Metabolic; Methodology; Modification; Molecular; Outcome; Pathogenesis; Pathway interactions; Patients; Peptide Initiation Factors; Phase; Phosphorylation; Physiological; Play; Poly(A)-Binding Proteins; Prevalence; Prevention; Preventive; Preventive Intervention; Proteins; Regulation; Research; Retina; Retinal; Retinal Detachment; Role; Serine; Signal Transduction; Site; Systems Analysis; Technical Expertise; Testing; Therapeutic Intervention; Threonine; Time; TimeLine; Training; Translations; United States; Up-Regulation; Vascular Endothelial Growth Factors; Vascular Permeabilities; Vision; Work; base; diabetic; innovation; mRNA capping; macular edema; middle age; molecular pathology; neovascularization; novel; pre-clinical; prevent; proliferative diabetic retinopathy; protein degradation; public health relevance; retinal damage; skills

Project Summary/Abstract Diabetic retinopathy is the leading cause of blindness in working age Americans, accounting for more than 12,000 new cases in the United States each year. The principle evidenced based treatment for proliferative diabetic retinopathy involves laser-mediated ablation, which fails to alter the molecular pathology of the disease, and as such, nearly half of patients require future treatments. Thus, our overall goal is to identify new targets for intervention at the molecular level that will lead to development of innovative, nondestructive therapies that address treatment of the cause of diabetic retinopathy, rather than the effect. The pathogenesis of this disease is caused by a combination of hyperglycemia and a reduction in insulin mediated signaling, which results in diabetic neurovascular complications through the induction of structural and physiological changes in the retina. The research proposed in this application is innovative, because it represents an entirely different approach to address the molecular basis of diabetic retinopathy, i.e. hyperglycemia-induced alterations in the translational control of gene expression. The central hypothesis is that the addition of O- linked N-Acetylglucosamine (O-GlcNAcylation) to serine or threonine residues of translation initiation factors mediates a shift from cap-dependent to cap-independent mRNA translation, resulting in an altered gene expression pattern that contributes to the pathophysiology of diabetic retinopathy. The hypothesis is supported by findings of elevated flux of glucose through the hexosamine biosynthetic pathway and O-GlcNAcylation of key components of the mRNA cap-binding complex, including eIF4E binding protein 1, eIF4G, eIF4A, and poly(A)-binding protein, under conditions of diabetes-induced hyperglycemia. Furthermore, herein we provide preliminary evidence that hyperglycemia favors the translation of mRNAs with internal ribosome entry sites, such as those encoding key vascular growth factors, in a manner that is dependent on the disruption of eIF4F complex assembly. During the mentored phase, the PI will acquire technical expertise from the laboratory of Dr. Gerald Hart on the methodology used to identify O-GlcNAcylation sites in proteins that control mRNA translation. Once the modified sites have been identified, the mechanisms through which hyperglycemia impairs eIF4F complex assembly will be defined. The mentored phase will also provide time for the candidate to receive guidance from Dr. Thomas Gardner to evaluate if preventing disruption of eIF4F complex assembly is sufficient to inhibit early preclinical phases of the pathogenesis of this disease in a mouse model of diabetes. With respect to outcomes, this project is expected to not only expand the PI's skills and systems of analysis, but will also identify novel mechanisms that link the metabolic abnormalities associated with diabetes to enhanced vascular growth factor expression in the retina. Identification of such mechanisms is significant because it is expected to validate new targets for the development of preventive and/or therapeutic interventions aimed at addressing the molecular basis of diabetic retinopathy and promoting healthy vision.

项目摘要/摘要 糖尿病性视网膜病是美国人失明的主要原因 每年美国有12,000个新案件。基于增生的基于基于的原理治疗 糖尿病性视网膜病涉及激光介导的消融，这不会改变 疾病，因此，将近一半的患者需要将来治疗。因此，我们的总体目标是确定新的 在分子水平上进行干预的靶标，这将导致创新，无损的发展 解决糖尿病性视网膜病因的治疗方法的治疗方法，而不是影响。发病机理 这种疾病是由高血糖和胰岛素介导的信号传导减少的组合引起的 通过诱导结构和生理，导致糖尿病神经血管并发症 视网膜变化。本应用程序中提出的研究具有创新性，因为它代表了 完全不同的方法来解决糖尿病性视网膜病的分子基础，即高血糖诱导的 基因表达的翻译控制的改变。中心假设是添加O- 连接的N-乙酰葡萄糖（O-Glcnacylation）与翻译起始因子的丝氨酸或苏氨酸残基 介导了从帽依赖性到帽独立的mRNA翻译的转变，导致基因改变 有助于糖尿病性视网膜病理生理学的表达模式。支持该假设 通过发现葡萄糖升高的发现通过己糖胺生物合成途径和O-Glcnacylation的发现 mRNA帽结合复合物的关键成分，包括EIF4E结合蛋白1，EIF4G，EIF4A和 在糖尿病诱导的高血糖症的条件下，聚（A）结合蛋白。此外，我们在此提供 高血糖有利于使用内部核糖体进入位点的MRNA翻译的初步证据， 例如那些编码关键血管生长因子的人，以依赖EIF4F的破坏方式 复杂的组件。在指导阶段，PI将从实验室中获得技术专长 杰拉尔德·哈特（Gerald Hart）博士在控制mRNA的蛋白质中用于识别O-Glcnacylation位点的方法 翻译。一旦确定了修改的位点，高血糖的机制 将定义损害EIF4F复合体组件。指导阶段还将为候选人提供时间 要从托马斯·加德纳（Thomas Gardner）博士获得指导，以评估是否防止EIF4F复合组装的破坏 在糖尿病小鼠模型中，足以抑制该疾病发病机理的早期临床前阶段。 关于结果，预计该项目不仅会扩大PI的技能和分析系统，而且还会扩大 但还将确定将与糖尿病相关的代谢异常联系起来的新型机制 视网膜中增强的血管生长因子表达。这种机制的识别很重要 因为预计将验证预防和/或治疗的新目标 旨在解决糖尿病性视网膜病的分子基础并促进健康视力的干预措施。