Role of proteolytic suPAR fragment in insulin dependent diabetes and kidney disease

蛋白水解suPAR片段在胰岛素依赖性糖尿病和肾脏疾病中的作用

• 批准号: 10654224
• 负责人: Jochen Reiser
• 金额: $ 69.56万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-01 至 2028-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10654224
• 关键词: Address; Applications Grants; Chronic; Chronic Kidney Failure; Clinical; Complications of Diabetes Mellitus; Cyclic GMP; Data; Development; Diabetes Mellitus; Diabetic Nephropathy; Disease; Disease Progression; Drug Targeting; Epidemic; Etiology; Female; Fibrosis; Goals; Gonadal Steroid Hormones; Human; Inflammation; Inflammatory; Injury; Injury to Kidney; Insulin-Dependent Diabetes Mellitus; Kidney; Kidney Diseases; Knowledge; Link; Malignant Neoplasms; Mitochondria; Modeling; Molecular; Non obese; Organ; Pancreas; Pathway interactions; Pharmaceutical Preparations; Pharmacologic Substance; Physiological; Pilot Projects; Plasma; Play; Population; Publishing; Rattus; Renin-Angiotensin-Aldosterone System; Reporting; Research; Risk Factors; Role; Sex Differences; Signal Pathway; Signaling Protein; Stimulator of Interferon Genes; Structure of beta Cell of islet; Study models; Therapeutic; Tubular formation; Type 2 diabetic; Urokinase; Virulence Factors; Woman; cell type; defined contribution; design; diabetic; disease phenotype; drug development; hypertensive; in vivo; inhibitor; interest; male; men; novel; podocyte; receptor; sex; sexual dimorphism; translational potential

The global epidemic of chronic kidney disease (CKD) is progressing at an alarming rate. CKD affects an estimated 37 million people in the U.S. (15% of the adult population; more than 1 in 7 adults), and this number has more than doubled in the last two decades. Kidney-related diseases are rapidly eluding present treatment options and resources. The three common causes of CKD are diabetes mellitus, hypertension, and glomerulonephritis. We and others have implicated soluble urokinase activating receptor (suPAR) as one of the significant risk factors for both, the onset as well as the progression of CKD, regardless of its etiologies. In addition to its role as a biomarker, we and others have suggested that suPAR is a pathogenic/scarring factor that underlies podocyte injury by activating v3 integrin on podocytes. Podocytes are terminally differentiated cells essential for maintaining the specificity of the kidney filter. Our preliminary data suggest that the presence of the proteolytic fragment of suPAR, D2D3 fragment, in the plasma induces glomerular injury by activating v3 integrin on podocytes. In addition, and highly unexpectedly, our preliminary studies suggest that the D2D3 fragment also injures -cells of the pancreas. Together, these insights suggest a hypothesis that circulating D2D3 fragment simultaneously causes injury to two organs, the kidney and pancreas. We test this hypothesis in 3 Specific Aims. In Specific Aim 1, we define the physiological mechanisms by which D2D3 induces kidney and pancreas injuries by examining organ functions in D2D3-Tg mice on regular- and high-fat- diet challenged by nephrotoxic serum or Adriamycin. In addition, we will cross D2D3-Tg mice with Non-Obese Diabetic (NOD) mice to examine synergy upon pancreas injury. Anti-suPAR antibodies and small molecules that target regulatory GTPases (dynamin, Cdc42, Rac1), whose roles will be elucidated in Aims 2 and 3, will be tested as potential therapeutics. As D2D3-Tg mice exhibit dual organ injury, combination treatments targeting diverse pathways in distinct cell types will also be investigated. In Specific Aim 2, we examine the effects of the D2D3 fragment on the actin cytoskeleton, regulatory GTPases, mitochondrial function, and gene expression in terminally differentiated and primary podocytes in the presence and absence of lipotoxic stimuli or high glucose levels. We focus on the effects of D2D3 on a feedback loop between the actin cytoskeleton and mitochondrial function, and its modifications by changes in podocyte physiology. In Specific Aim 3, we examine the effects of D2D3 on glucose uptake, intracellular Ca2+ dynamics, cytoskeleton dynamics, and gene expression in -cells, isolated mouse islets, and tissue slices. The proposed study, delineating molecular mechanisms and the physiological relevance of dual organ injury, is a critical step in developing novel mechanism-specific therapeutics for CKD and insulin-dependent diabetes mellitus.

慢性肾脏疾病（CKD）的全球流行病正在以惊人的速度发展。 CKD在美国影响约3700万人（占成年人口的15％；在7个成年人中有1人），在过去的二十年中，这一数字增加了一倍以上。与肾脏有关的疾病正在迅速避免目前的治疗选择和资源。 CKD的三个常见原因是糖尿病，高血压和肾小球肾炎。我们和其他人已经实施了可溶性尿激酶激活受体（SUPAR），作为CKD的发作和进展的重要危险因素之一，无论其病因如何。除了作为生物标志物的作用外，我们和其他人还建议SUPAR是一种致病/疤痕因子，它是通过在足细胞上激活V3整合素来构成足细胞损伤的基础。足细胞是维持肾脏过滤的特异性必不可少的终末分化细胞。我们的初步数据表明，血浆中Supar，D2D3片段的蛋白水解片段的存在通过激活足细胞上的V3整合素来诱导肾小球损伤。此外，高度出乎意料的是，我们的初步研究表明D2D3片段也受伤。这些见解共同提出了一个假设，即循环D2D3碎片只是对两个器官，肾脏和胰腺造成伤害。我们以3个特定目的检验了这一假设。在特定目标1中，我们定义了D2D3通过检查肾毒性血清或adriamycin挑战的常规和高脂肪饮食中D2D3-TG小鼠的器官功能来诱导肾脏和胰腺损伤的物理机制。此外，我们将与非肥胖糖尿病（NOD）小鼠穿越D2D3-TG小鼠，以检查胰腺损伤时的协同作用。抗舒巴抗体和针对调节性GTPases的小分子（Dynamin，cdc42，rac1），其作用将在AIM 2和3中阐明，将被视为潜在的治疗。随着D2D3-TG小鼠暴露了双器官损伤，还将研究针对不同细胞类型的潜水途径的组合处理。在特定的目标2中，我们检查了D2D3片段对肌动蛋白细胞骨架，调节性GTPase，线粒体功能和基因表达在终端分化和原发性足细胞中的基因表达中的影响，在存在和不存在Lipototototoxic刺激或高葡萄糖水平的情况下。我们专注于D2D3对肌动蛋白细胞骨架和线粒体功能之间的反馈回路的影响，以及通过Podocyte生理学的变化进行的修饰。在特定目标3中，我们检查了D2D3对细胞，分离的小鼠胰岛和组织切片中葡萄糖摄取，细胞内CA2+动力学，细胞骨架动力学和基因表达的影响。拟议的研究，描述分子机制和双器官损伤的物理相关性，是开发针对CKD和胰岛素依赖性糖尿病的新型机制治疗的关键步骤。