NADPH oxidase, mitochondrial dysfunction and diabetic retinopathy

NADPH 氧化酶、线粒体功能障碍和糖尿病视网膜病变

基本信息

批准号：
10357931
负责人：
RENU A. KOWLURU
金额：
$ 37.35万
依托单位：
WAYNE STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-04-01 至 2024-02-29
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10357931
关键词：
Address Anabolism Animal Model Apoptosis Apoptotic Binding Biological Blindness Blood capillaries Cells Ceramides Complex Complications of Diabetes Mellitus Cytosine DNA DNA Methylation DNA Modification Methylases DNA Modification Process DNA Sequence Data Development Diabetes Mellitus Diabetic Retinopathy Disease Dyslipidemias Electron Transport Endothelial Cells Enzymes Epigenetic Process Exposure to Funding G-Protein Signaling Pathway GTP Binding GTPase-Activating Proteins Gene Expression Genes Genetic Transcription Goals Guanine Guanine Nucleotide Dissociation Inhibitors Guanine Nucleotide Exchange Factors Holoenzymes Human Hydroxyl Radical Hydroxylation Hyperglycemia Hyperlipidemia Laboratories Lipids Mediating Membrane Messenger RNA Methodology Methylation Mitochondria Modification Molecular Monomeric GTP-Binding Proteins NADPH Oxidase NF-kappa B Non-Insulin-Dependent Diabetes Mellitus Pathogenesis Patients Pattern Pharmacology Post-Translational Protein Processing Prediabetes syndrome Process Production Protein Isoprenylation Publishing Reactive Oxygen Species Regulation Reporting Research Retina Retinal Diseases Rodent Rodent Model Role Signal Transduction Structure Testing Tetanus Helper Peptide Therapeutic Transcript Transcriptional Activation Transcriptional Regulation Translating Type 2 diabetic Vision Work base diabetic gene induction gene repression in vitro Model in vivo inhibitor innovation member methyl group mitochondrial dysfunction multidisciplinary new therapeutic target novel predictive modeling prenylation prevent promoter rac1 GTP-Binding Protein small molecule inhibitor thermozymocidin translational impact translational potential translocase young adult

项目摘要

Diabetic retinopathy remains a major cause of blindness, and despite cutting edge research in the field, the molecular mechanism of its pathogenesis remains unclear. Our recent research has shown that during early stages of this progressing disease, activation of cytosolic NADPH oxidase 2 (Nox2) generates reactive oxygen species (ROS), and sustained increase in cytosolic ROS damages mitochondrial structure and its DNA, dysregulating the electron transport chain and initiating a vicious cycle of ROS. Furthermore, we have shown that dyslipidemia accelerates Nox2-mediated mitochondrial damage and the development of diabetic retinopathy in a type 2 diabetic animal model. An integral part of the cytosolic core of Nox2 holoenzyme is the small G-protein, Rac1, and diabetes increases Rac1 activity and gene transcripts in retinal microvasculature. Rac1 functional activation is mediated by its binding with the guanine exchange factors (GEFs) and guanine nucleotide dissociation inhibitors (GDIs). Many epigenetic modifications are also favored by diabetic milieu, and these covalent modifications regulate gene expression without altering the DNA sequence. Thus, the central hypothesis of the current application is that covalent modifications of Rac1 modulate its functional and transcriptional activation, and activated Rac1, via Nox2-mediated ROS production, damages the mitochondria, resulting in accelerated apoptosis and the development of diabetic retinopathy. Aim 1 will investigate the molecular mechanism(s) by which hyperglycemia promotes activation of Rac1. Our model predicts that defective prenylation of Rac1 results in its sustained activation and mislocalization, and dynamic DNA methylation- hydroxymethylation of Rac1 promoter facilitates its transcriptional activation. Aim 2 will delineate the mechanism(s) by which gluco/lipotoxicity accelerates the development of diabetic retinopathy, and will investigate the effect of dyslipidemia on functional and transcriptional activation of Rac1. Questions asked under Aim 3 will address the therapeutic potential of regulation of Rac1 activation on inhibition of diabetic retinopathy, and will test novel small molecule inhibitors of GEF and of ceramide biosynthesis. The plan will employ fully optimized molecular biological and pharmacological approaches to assess the effect of diabetes on functional and transcriptional regulation of Rac1 activation in isolated retinal endothelial cells in culture, and in retinal microvessels from (pre-, type 1 and type 2) diabetic rodent models and from human donors with established diabetic retinopathy. Our overall goal is to identify novel regulatory mechanisms involved in the pathogenesis of diabetic retinopathy, specifically at the level of functional and transcriptional regulation of Rac1. The proposal is based on a testable central hypothesis, and these innovative studies carry a significant translational impact as they are expected to identify novel therapeutic targets to inhibit the development and progression of diabetic retinopathy.

糖尿病性视网膜病仍然是失明的主要原因，尽管该领域的尖端研究，但其发病机理的分子机制尚不清楚。我们最近的研究表明，早期这种进展疾病的阶段，胞质NADPH氧化酶2（NOX2）的激活产生活性氧气物种（ROS），胞质ROS损害线粒体结构及其DNA的持续增加，电子传输链失调并启动ROS的恶性循环。此外，我们已经显示血脂异常加速了NOX2介导的线粒体损伤和糖尿病的发展 2型糖尿病动物模型中的视网膜病变。 Nox2全酶的胞质核的组成部分是小型G蛋白，RAC1和糖尿病会增加视网膜微脉管系统中的Rac1活性和基因转录本。 RAC1功能激活是由其与鸟嘌呤交换因子（GEF）和鸟嘌呤结合的介导的核苷酸解离抑制剂（GDI）。许多表观遗传修饰也受到糖尿病环境的青睐，这些共价修饰调节基因表达而不改变DNA序列。因此，当前应用的中心假设是Rac1的共价修改调节其功能和通过NOX2介导的ROS产生的转录激活和激活的Rac1损害线粒体，导致加速凋亡和糖尿病性视网膜病的发展。 AIM 1将研究高血糖促进Rac1激活的分子机制。我们的模型预测，Rac1的缺陷核化导致其持续的激活和错误定位，并且 RAC1启动子的动态DNA甲基化 - 羟基甲基化促进其转录激活。目标2 将描述葡萄糖/脂肪毒性加速糖尿病性视网膜病的发展的机制，并将研究血脂异常对RAC1功能和转录激活的影响。问题在AIM 3下被问到将解决Rac1激活对抑制的治疗潜力糖尿病性视网膜病，将测试GEF和神经酰胺生物合成的新型小分子抑制剂。这计划将采用完全优化的分子生物学和药理学方法来评估 RAC1激活在分离的视网膜内皮细胞中Rac1激活功能和转录调控的糖尿病培养，以及来自（预，1型和2型）糖尿病啮齿动物模型的视网膜微血管和人类患有糖尿病性视网膜病的供体。我们的总体目标是确定新颖的监管机制参与糖尿病性视网膜病的发病机理，特别是在功能和转录水平上 Rac1的调节。该提案基于可检验的中央假设，这些创新研究携带他们预计将确定新型治疗靶标以抑制的重大翻译影响糖尿病性视网膜病的发展和进展。

项目成果

期刊论文数量（5）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Potential roles of PP2A-Rac1 signaling axis in pancreatic β-cell dysfunction under metabolic stress: Progress and promise.

DOI：
10.1016/j.bcp.2020.114138
发表时间：
2020-10
期刊：
BIOCHEMICAL PHARMACOLOGY
影响因子：
5.8
作者：
Kowluru, Anjaneyulu
通讯作者：
Kowluru, Anjaneyulu

P-Rex1 Mediates Glucose-Stimulated Rac1 Activation and Insulin Secretion in Pancreatic β-Cells.

DOI：
10.33594/000000310
发表时间：
2020-12-12
期刊：
CELLULAR PHYSIOLOGY AND BIOCHEMISTRY
影响因子：
0
作者：
Thamilselvan, Vijayalakshmi;Gamage, Suhadinie;Harajli, Ali;Chundru, Sri Aneesha;Kowluru, Anjaneyulu
通讯作者：
Kowluru, Anjaneyulu

Regulatory roles of CARD9-BCL10-Rac1 (CBR) signalome in islet β-cell function in health and metabolic stress: Is there room for MALT1?