Thioredoxin Interacting Protein (TXNIP) expression is critical in the development of early diabetic retinopathy

硫氧还蛋白相互作用蛋白 (TXNIP) 表达对于早期糖尿病视网膜病变的发展至关重要

• 批准号: 9389495
• 负责人: LALIT SINGH PUKHRAMBAM
• 金额: $ 34.65万
• 依托单位: WAYNE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-12-02 至 2019-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9389495
• 关键词: Address; Antioxidants; Apoptosis; Area; Binding Proteins; Blood Vessels; Cells; Cellular Stress; Cessation of life; Chromatin; Chronic; Chronic Disease; Citric Acid Cycle; Complications of Diabetes Mellitus; Data; Defect; Development; Diabetes Mellitus; Diabetic Retinopathy; Diabetic mouse; Dissection; Dynamin; Electron Transport; Enzymes; Functional disorder; Gene Expression; Gene Expression Profile; Generations; Genes; Gliosis; Glucose; Growth Factor; HMGB1 Protein; Health; Heat shock proteins; Homeostasis; Hyperglycemia; In Vitro; Inflammation; Injury; Ischemia; Knowledge; Lead; Mediating; Mitochondria; Molecular; Molecular Chaperones; Muller' s cell; Mus; Nerve Degeneration; Neuroglia; Neuronal Injury; Neurons; Nuclear; Oxidation-Reduction; Oxidative Stress; Pathogenesis; Pathology; Pharmacotherapy; Play; Prevention; Process; Production; Protein Overexpression; Protein S; Proteins; Publications; Publishing; Reactive Oxygen Species; Reperfusion Therapy; Research; Research Personnel; Retina; Retinal; Role; Signal Pathway; Signal Transduction; Small Interfering RNA; Streptozocin; Stress; Sulfhydryl Compounds; TXN gene; TXNIP gene; Testing; base; biological adaptation to stress; cell injury; cell type; cytokine; diabetic rat; dopaminergic neuron; enzyme activity; experimental study; gene induction; gene therapy; glial activation; in vivo; innovation; knock-down; mitochondrial dysfunction; mouse model; neurotrophic factor; novel; novel strategies; preservation; prevent; promoter; protein expression; public health relevance; response; synaptopodin; transcription factor; type I diabetic

DESCRIPTION (provided by applicant): Mitochondrial (MT) dysregulation and resultant energy imbalance is associated with various chronic diseases including neuro-degeneration, ischemia/reperfusion, and diabetic complications such as diabetic retinopathy (DR). Recently, we published that pro-oxidant thioredoxin interacting protein (TXNIP) is significantly up-regulated in DR and under hyperglycemia in retinal cells in culture including Muller cells (MC) and mediates cellular oxidative stress and inflammation. TXNIP has recently been implicated by several studies as a critical protein in the pathogenesis of diabetes and its complications including DR. TXNIP binds to thioredoxin (Trx), a redox anti-oxidant protein, inhibiting its reactive oxygen species (ROS) scavenging and thiol reducing capacity; therefore, results in cellular oxidative/nitrosative (ROS/RNS) stress and aberrant protein s-nitrosylation. Furthermore, MC are important for retinal health and activated MC (gliosis) induces aberrant gene expression for cytokines and growth factors to maintain retinal homeostasis. However, prolonged MC activation is injurious in DR. Therefore, our overall hypothesis is that TXNIP is critical for MT dysfunction and MC activation in the development of DR. We propose to test two specific aims: aim 1. that TXNIP induces MT dysfunction and evokes nuclear stress responses in early DR; and aim 2. that TXNIP regulates MT fission and mitophagy in early DR. To address the objectives, we will use streptozotocin (STZ)-induced type 1 diabetic models of rat and mouse in conjunction with manipulation of TXNIP expression levels in the retina. In vitro studies using retinal MC will also be performed to dissect the molecular mechanisms as to how TXNIP induces MT dysfunction and mitophagy, which specifically removes damaged MT. Our proposal is innovative because we address still unexplored important areas of research in DR. These include: (i) MT retrograde stress signaling to maintain MT homeostasis in DR; (ii) molecular mechanism(s) of MT fission and mitophagy, critical for preservation of MT homeostasis in DR: (iii) understanding the role played by TXNIP in retinal MC activation (gliosis) and retinal neuronal injury/death in DR; and (iv) development of a novel strategy for TXNIP knock down in the retina by siRNA-targeted to TXNIP promoter and chromatin closing (RNAi eTGS). Hence, our proposed innovative studies will fill the knowledge gap that currently exists in understanding DR initiation and progression. Furthermore, the results will allow us to identify potential targets for developing new gene/drug therapies and ameliorate the ocular complications of diabetes.

描述（由申请人提供）：线粒体（MT）失调和由此产生的能量失衡与各种慢性疾病相关，包括神经变性、缺血/再灌注和糖尿病并发症，如糖尿病视网膜病变（DR）。最近，我们发表了促氧化剂硫氧还蛋白相互作用蛋白（TXNIP）在DR和高血糖下在培养的视网膜细胞（包括Muller细胞（MC））中显著上调，并介导细胞氧化应激和炎症。TXNIP是糖尿病及其并发症（包括DR）发病机制中的关键蛋白质。TXNIP与硫氧还蛋白（Trx）（一种氧化还原抗氧化蛋白）结合，抑制其活性氧（ROS）清除和巯基还原能力;因此，导致细胞氧化/亚硝化（ROS/RNS）应激和异常蛋白质S-亚硝基化。此外，MC对于视网膜健康是重要的，并且活化的MC（神经胶质增生）诱导细胞因子和生长因子的异常基因表达以维持视网膜稳态。然而，延长MC激活是有害的DR。因此，我们的总体假设是，TXNIP是MT功能障碍和MC激活的DR的发展至关重要。我们建议测试两个具体的目标：目的1。TXNIP在早期DR中诱导MT功能障碍并引起核应激反应;和目的2。TXNIP调节MT分裂和线粒体自噬在早期DR。为了解决的目标，我们将使用链脲佐菌素（STZ）诱导的1型糖尿病模型的大鼠和小鼠在视网膜中的TXNIP表达水平的操纵。还将进行使用视网膜MC的体外研究，以剖析TXNIP如何诱导MT功能障碍和线粒体自噬的分子机制，其特异性地去除受损的MT。我们的建议是创新的，因为我们解决了DR中尚未探索的重要研究领域。这些领域包括：（i）MT逆行应激信号传导以维持DR中MT稳态;（ii）MT分裂和线粒体自噬的分子机制，这对于DR中MT稳态的维持至关重要;（iii）理解TXNIP在DR中视网膜MC激活（胶质增生）和视网膜神经元损伤/死亡中所起的作用;和（iv）通过靶向TXNIP启动子和染色质封闭的siRNA（RNAi eTGS）开发了在视网膜中敲低TXNIP的新策略。因此，我们提出的创新研究将填补目前在理解DR启动和进展方面存在的知识空白。此外，这些结果将使我们能够确定潜在的目标， 用于开发新的基因/药物疗法和改善糖尿病的眼部并发症。