NO Dysregulation of the Peripheral Clock in Diabetic Complications

糖尿病并发症中没有外周时钟失调

基本信息

批准号：
8304286
负责人：
Maria Bartolomeo Grant
金额：
$ 29.96万
依托单位：
UNIVERSITY OF FLORIDA
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-09-30 至 2013-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8304286
关键词：
Affect Albumins Animals Arterial Fatty Streak Atherosclerosis Binding Proteins Bioavailable Biological Availability Blindness Blood Circulation Blood Vessels Blood capillaries Bone Marrow Bone Marrow Cells Cell Aging Cell Maturation Cells Circadian Rhythms Clock protein Complications of Diabetes Mellitus Defect Development Diabetes Mellitus Diabetic Angiopathies Diabetic Retinopathy Down-Regulation Endothelial Cells Endothelium Equilibrium Feedback Frequencies Functional disorder Gene Expression Gene Targeting Genes Health Homeostasis Hyperplasia Injury Knock-out Knockout Mice Lead Literature Maintenance Metabolic Metabolic Control Modeling Molecular Neuropathy Nitric Oxide Non-Insulin-Dependent Diabetes Mellitus Organ Pacemakers Pathogenesis Pathology Pathway interactions Pattern Periodicity Peripheral Peroxisome Proliferator-Activated Receptors Peroxonitrite Phase Phenotype Plasminogen Plasminogen Activator Inhibitor 1 Plasminogen Inactivators Play Post-Translational Protein Processing Proteins Publishing Rattus Reactive Oxygen Species Regulation Retinal Role Site Stem cells Testing Vasa Nervorum Vasopressins Work arm base capillary cell type diabetic human NOS3 protein inhibitor/antagonist mortality new therapeutic target non-diabetic public health relevance repaired response to injury restoration therapeutic target

项目摘要

DESCRIPTION (provided by applicant): Using a rat model of type 2 diabetes (T2D), we showed that at 2 months of T2D the decrease in bone marrow progenitor cell (BMPC) release from diabetic bone marrow (BM) is caused by BM neuropathy and that these changes precede the development of diabetic retinopathy (DR). BM neuropathy was associated with a marked reduction in clock gene expression in the BMPCs themselves which led to diminished repair by these cells and by 4 months of T2D resulted in the hallmark feature of diabetic retinopathy (DR), acellular retinal capillaries. Diabetic BMPC dysfunction was corrected by increasing levels of bioavailable nitric oxide (NO) towards normal non-diabetic levels. Since NO modulates clock gene expression, the reduced levels of bioavailable NO results in altered clock gene expression. Plaminogen activator inhibitor (PAI-1), an important modulator of hematopoetic stem cell maturation and release from the BM is an immediate downstream metabolic regulator controlled by clock genes. PAI-1 demonstrates a robust circadian pattern in health, but this pattern is altered in diabetes and elevated levels are produced by endothelial cells (EC) from diabetics. We believe this NO-modulated clock gene dysfunction leads to the loss of circadian regulation of PAI-1 and represents an underlying mechanism and therapeutic target for DR and atherosclerosis, which are the major causes of blindness and mortality in diabetics, respectively. In this application, we propose the following hypothesis: In diabetes, a reduction in bioavailable NO in ECs and BMPCs causes a diminished amplitude and frequency of the oscillatory pattern of the clock proteins, BMAL1 and PER-2, leading to a loss of circadian regulation of PAI-1 and subsequent further diminution of NO levels in EC and BMPCs. Decreasing NO bioavailability and persistent increase in PAI-1 in the vasa nervorum leads to development of BM neuropathy which results in defective EPC mobilization further exacerbating end organ complications. To test our hypothesis, we propose the following aims: 1) to determine whether NO bioavailability can affect the molecular clock and circadian rhythms in vascular ECs and BMPCs and to determine whether levels of NO will have direct and indirect effects on clock gene expression via S-nitrosylation of essential clock proteins such as BMAL1 and PER-2; 2) to determine whether specific clock gene knock-out of the endothelium and BMPC recapitulates the diabetic vascular phenotype of accelerated injury and reduced repair; and 3) to determine whether dysregulation of NO and PAI-1 within the vasa nervorum leads to BM neuropathy and loss of circadian release of BMPCs into the circulation. PUBLIC HEALTH RELEVANCE: This proposal represents a paradigm shift in our understanding of the pathogenesis of diabetic micro- and macro-vascular complications. We are testing whether circadian oscillators play a pivotal role in endothelial cell and bone marrow progenitor cells homeostasis. We believe that when disrupted in diabetes, they must be restored before vascular health is achieved. We specifically identify plasminogen activator inhibitor as a novel therapeutic target in diabetes to restore vascular function and circadian oscillation of nitric oxide in vascular and bone marrow cells.

描述（由申请人提供）：使用 2 型糖尿病 (T2D) 大鼠模型，我们发现在 T2D 2 个月时，糖尿病骨髓 (BM) 中骨髓祖细胞 (BMPC) 释放的减少是由 BM 神经病变引起的并且这些变化先于糖尿病视网膜病变（DR）的发展。 BM 神经病变与 BMPC 本身的时钟基因表达显着减少有关，这导致这些细胞的修复能力减弱，到 2D 4 个月时，导致糖尿病视网膜病变 (DR) 的标志性特征，即视网膜毛细血管脱细胞。通过将生物可利用的一氧化氮 (NO) 水平提高到正常的非糖尿病水平来纠正糖尿病 BMPC 功能障碍。由于 NO 调节时钟基因表达，生物可利用的 NO 水平降低会导致时钟基因表达改变。纤溶酶原激活剂抑制剂 (PAI-1) 是造血干细胞成熟和从 BM 释放的重要调节剂，是受时钟基因控制的直接下游代谢调节剂。 PAI-1 在健康状况下表现出强大的昼夜节律模式，但这种模式在糖尿病中发生了改变，并且糖尿病患者的内皮细胞 (EC) 产生了升高的水平。我们相信，这种 NO 调节的时钟基因功能障碍会导致 PAI-1 昼夜节律调节的丧失，并代表 DR 和动脉粥样硬化的潜在机制和治疗靶点，而 DR 和动脉粥样硬化分别是糖尿病患者失明和死亡的主要原因。在本申请中，我们提出以下假设：在糖尿病中，EC 和 BMPC 中生物可利用的 NO 减少会导致时钟蛋白 BMAL1 和 PER-2 振荡模式的幅度和频率降低，从而导致昼夜节律调节丧失PAI-1 的减少以及随后 EC 和 BMPC 中 NO 水平的进一步降低。 NO 生物利用度的降低和神经血管中 PAI-1 的持续增加会导致 BM 神经病变的发生，从而导致 EPC 动员缺陷，进一步加剧终末器官并发症。为了检验我们的假设，我们提出以下目标：1）确定NO生物利用度是否会影响血管EC和BMPC中的分子钟和昼夜节律，并确定NO水平是否会通过S对时钟基因表达产生直接和间接影响-必需时钟蛋白（例如 BMAL1 和 PER-2）的亚硝基化； 2) 确定内皮和BMPC的特定时钟基因敲除是否概括了加速损伤和减少修复的糖尿病血管表型； 3) 确定神经血管内 NO 和 PAI-1 的失调是否会导致 BM 神经病变和 BMPC 昼夜节律释放到循环中的损失。公众健康相关性：该提案代表了我们对糖尿病微血管和大血管并发症发病机制理解的范式转变。我们正在测试昼夜节律振荡器是否在内皮细胞和骨髓祖细胞稳态中发挥关键作用。我们相信，当糖尿病发生中断时，它们必须在血管恢复健康之前得到恢复。我们特别将纤溶酶原激活剂抑制剂确定为糖尿病的新型治疗靶点，以恢复血管功能以及血管和骨髓细胞中一氧化氮的昼夜节律振荡。