Role of Protein S in early Diabetic Kidney Disease

蛋白 S 在早期糖尿病肾病中的作用

• 批准号: 9134973
• 负责人: John Cijiang He
• 金额: --
• 依托单位: JAMES J PETERS VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-01 至 2020-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9134973
• 关键词: Acetylation; Actins; Adhesions; Advanced Glycosylation End Products; Affect; Affinity; Animal Model; Anti-Inflammatory Agents; Anti-inflammatory; Apoptosis; Apoptotic; Binding; Cell Proliferation; Cell Survival; Cells; Chronic; Code; Complications of Diabetes Mellitus; Cytoprotection; Cytoskeleton; Data; Diabetes Mellitus; Diabetic Nephropathy; Diabetic mouse; Dialysis procedure; Disease; Disease Progression; Emotional; End stage renal failure; Endothelial Cells; Family; Foot Process; Funding; Gene Expression; Glomerulonephritis; Glucose; Healthcare; Histology; Human; Hypertrophy; In Vitro; Incidence; Incubated; Individual; Inflammation; Inflammatory; Inflammatory Response; Injury; Insulin; Kidney; Kidney Diseases; Kidney Failure; Knock-out; Knockout Mice; Major Depressive Disorder; Measures; Mediating; Mus; Pathogenesis; Patients; Pharmaceutical Preparations; Plasma; Post-Traumatic Stress Disorders; Preventive; Progress Reports; Protein S; Proteins; Proteinuria; Proteomics; Quality of life; Receptor Protein-Tyrosine Kinases; Regulation; Renal function; Research; Role; STAT3 gene; Signal Pathway; Streptozocin; TNF gene; Testing; Therapeutic; Vascular Endothelial Growth Factors; Veterans; Wild Type Mouse; activated Protein C; angiogenesis; base; cell injury; cell motility; cofactor; diabetic; diabetic rat; in vivo; knock-down; mesangial cell; migration; mortality; mouse model; non-diabetic; novel; novel strategies; overexpression; patient population; podocyte; prevent; protective effect; public health relevance; receptor

 DESCRIPTION (provided by applicant): Project Summary Diabetic kidney disease (DKD) is the common cause of kidney failure. Elucidating mechanisms that mediate the early stage of DKD may help to identify novel preventive and therapeutic measures for patients with DKD. In the previous funding period, we demonstrated a critical role of NF-κB and STAT3 acetylation in DKD through the regulation of inflammatory gene expression (see progress report). To further understand the mechanism of early DKD injury, we performed proteomic studies in the glomeruli of streptozotocin (STZ)-induced diabetic rats and identified protein S (PS) as one of the proteins which were highly regulated in early DKD. PS, coded by Pros1, is a cofactor for the formation of activated protein C (APC). APC formation has been shown to protect glomerular cells from apoptosis in DKD. In addition, PS shares structural similarities with GAS6, which is known to be involved in the pathogenesis of kidney disease. Both PS and GAS6 bind to TAM receptors (Tyro3, Axl, and Mer), which belong to a family of receptor tyrosine kinases that mediates regulation of inflammation as well as cell survival and migration. However, PS and GAS6 have different binding affinity to individual TAM receptors and appear to have different functions. The role of PS and TAM receptors in kidney disease is not known. Our preliminary data suggest that PS expression increased in the glomeruli of diabetic rats and in human kidneys with early DKD, but decreased in those with advanced DKD. Plasma concentrations of PS were not different between diabetic and non-diabetic rats or humans, suggesting a local regulation of PS expression. We found that knockdown of PS in podocytes enhanced high glucose-induced apoptosis while overexpression of PS inhibited TNF-α-induced pro-inflammatory gene expression, suggesting a protective role of PS against diabetes-induced podocyte injury. We found that Tyro3, one of the TMA receptors, was upregulated by high glucose and knockdown of Tyro3 expression abolished the protective effects of PS in podocytes. Tyro3 expression is also upregulated in human glomeruli at early DKD but downregulated at late DKD. We developed podocyte-specific Pros1 knockout mice (KO) and found that diabetic KO mice developed more proteinuria, mesangial expansion, and foot process effacement than diabetic wild-type mice. Based on these findings, we hypothesize that PS may protect glomerular cell injury in early DKD through the formation of APC and/or effects mediated by Tyro3. We will test our hypothesis by two aims: In the aim 1, we will determine the factors which upregulate PS and Tyro3 at early DKD and those suppress PS and Tyro3 at late DKD and the effects of PS and Tyro3 in podocytes cultured in diabetic condition. In the aim 2 we will determine the role of PS and Tyro3 in DKD progression in vivo using both conditional overexpression and knockout mouse models for PS and Tyro3. We believe that the proposed studies could help us to elucidate the mechanism of glomerular cell injury in early DKD and therefore we could develop more effective drugs to prevent the progression of DKD.

 描述（由申请人提供）： 项目摘要糖尿病肾病（DKD）是肾衰竭的常见原因。阐明介导DKD早期阶段的机制可能有助于确定DKD患者的新型预防和治疗方法。在上一个资金期间，通过调节炎症基因表达，我们证明了NF-κB和STAT3乙酰化在DKD中的关键作用（请参阅进度报告）。为了进一步了解早期DKD损伤的机制，我们在链霉菌蛋白（STZ）诱导的糖尿病大鼠的肾小球研究中进行了蛋白质组学研究，并鉴定出蛋白S（PS）是在DKD早期受到高度调节的蛋白质之一。 PS，由Pros1编码，是形成活化蛋白C（APC）的辅助因子。已显示APC的形成可保护肾小球细胞免受DKD中凋亡的影响。此外，PS与GAS6共享结构相似性，众所周知，这与肾脏疾病的发病机理有关。 PS和GAS6都与TAM受体（Tyro3，AXL和MER）结合，属于介导炎症调节以及细胞存活和迁移的受体酪氨酸激酶家族。但是，PS和GAS6与单个TAM受体具有不同的结合亲和力，并且似乎具有不同的功能。 PS和TAM受体在肾脏疾病中的作用尚不清楚。我们的初步数据表明，糖尿病大鼠的肾小球和患有早期DKD的人肾脏的PS表达增加，但在患有晚期DKD的肾脏中会降低。 PS的血浆浓度在糖尿病和非糖尿病大鼠或人类之间没有差异，这表明PS表达的局部调节。我们发现，足细胞中PS的敲低增强了高葡萄糖诱导的细胞凋亡，而PS的过表达抑制了TNF-α诱导的促炎基因表达，这表明PS对糖尿病诱导的足细胞损伤的受保护作用。我们发现，TYRO3是TMA受体之一，通过高葡萄糖和TYRO3表达的敲低进行了更新，从而消除了PS在足细胞中的受保护作用。 Tyro3表达在DKD早期的人Glomerulli中也被更新，但在DKD晚期被下调。我们开发了足细胞特异性的Pros1敲除小鼠（KO），发现糖尿病KO小鼠比糖尿病性野生型小鼠产生的蛋白尿，肾小球膨胀和足部过程效率更多。基于这些发现，我们假设PS可以通过形成APC和/或由Tyro3介导的APC和/或效应来保护DKD早期的肾小球细胞损伤。我们将通过两个目的检验我们的假设：在AIM 1中，我们将确定在DKD早期上调PS和Tyro3的因素，这些因素在DKD晚期抑制PS和TYRO3，以及PS和TYRO3在糖尿病状况下培养的足细胞中PS和TYRO3的影响。在AIM 2中，我们将使用有条件的过表达和PS和Tyro3的敲除小鼠模型来确定PS和TYRO3在DKD进展中的作用。我们认为，拟议的研究可以帮助我们阐明DKD早期肾小球细胞损伤的机制，因此我们可以开发更有效的药物以防止DKD的发展。