NO Dysregulation of the Peripheral Clock in Diabetic Complications

糖尿病并发症中没有外周时钟失调

• 批准号: 8152123
• 负责人: Maria Bartolomeo Grant
• 金额: $ 29.98万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-30 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8152123
• 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

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（T2 D）大鼠模型，我们显示在2个月的T2 D时，骨髓祖细胞（BMPC）从糖尿病骨髓（BM）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自身中时钟基因表达的显著减少相关，这导致这些细胞的修复减少，并且到4个月的T2 D时，导致糖尿病视网膜病变（DR）的标志性特征，即脱细胞视网膜毛细血管。糖尿病BMPC功能障碍通过增加生物可利用的一氧化氮（NO）水平向正常的非糖尿病水平进行校正。由于NO调节时钟基因表达，生物可利用的NO水平降低导致时钟基因表达改变。纤溶酶原激活物抑制剂（派-1）是造血干细胞成熟和从骨髓释放的重要调节剂，是由时钟基因控制的直接下游代谢调节剂。派-1在健康中表现出强大的昼夜节律模式，但这种模式在糖尿病中发生改变，并且糖尿病患者的内皮细胞（EC）产生升高的水平。我们认为，这种NO调节的时钟基因功能障碍导致派-1昼夜节律调节的丧失，并代表了DR和动脉粥样硬化的潜在机制和治疗靶点，这两种疾病分别是糖尿病患者失明和死亡的主要原因。在本申请中，我们提出了以下假设：在糖尿病中，EC和BMPC中生物可利用的NO的减少导致时钟蛋白BMAL 1和PER-2的振荡模式的幅度和频率减小，导致派-1的昼夜节律调节的丧失，以及随后EC和BMPC中NO水平的进一步降低。降低NO生物利用度和持续增加派-1在神经血管导致BM神经病变的发展，这导致有缺陷的EPC动员进一步加剧终末器官并发症。为了验证我们的假设，我们提出了以下目标：1）确定NO生物利用度是否可以影响血管EC和BMPC的分子生物钟和昼夜节律，并确定NO水平是否会通过生物钟蛋白如BMAL 1和PER-2的S-亚硝基化直接或间接影响生物钟基因的表达; 2）确定内皮和BMPC的特异性时钟基因敲除是否再现了加速损伤和减少修复的糖尿病血管表型;和3）确定神经血管内NO和派-1的失调是否导致BM神经病变和BMPC进入循环的昼夜节律释放的丧失。 公共卫生相关性：这一建议代表了我们对糖尿病微血管和大血管并发症发病机制的理解的范式转变。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起关键作用。我们认为，当糖尿病中断时，它们必须在血管健康实现之前恢复。我们特别确定纤溶酶原激活物抑制剂作为糖尿病的新的治疗靶点，以恢复血管功能和血管和骨髓细胞中一氧化氮的昼夜节律振荡。