The role of NFAT in podocyte damage and proteinuric kidney disease

NFAT 在足细胞损伤和蛋白尿肾病中的作用

• 批准号: 8320645
• 负责人: ALEXIS JOANNA SLOAN
• 金额: $ 3.58万
• 依托单位: UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8320645
• 关键词: Accounting; Actins; Acute; Adult; Affect; Animal Model; Animals; Architecture; Bacterial Infections; Benign; Blood Pressure; Calcineurin; Calcium; Calcium Channel; Calcium Signaling; Cells; Cessation of life; Chronic Kidney Failure; Communities; Coupled; DNA Sequence Rearrangement; Data; Development; Disease; Doxycycline; Drug Delivery Systems; Electron Microscopy; Epigenetic Process; Event; Foot Process; Gene Expression; Gene Targeting; Genes; Genetic Transcription; Goals; Health; Healthcare; Hematoxylin and Eosin Staining Method; Histologic; Histological Techniques; Immunosuppressive Agents; In Vitro; Ion Channel; Kidney; Kidney Diseases; Kidney Failure; Kidney Glomerulus; Lead; Left; Life; Mediating; Microarray Analysis; Morphology; Mus; Nature; Nuclear; Pathology; Patients; Pattern; Periodic acid Schiff stain method; Permeability; Phenotype; Physiological; Population; Protein phosphatase; Proteins; Proteinuria; Public Health; Publishing; Quality of life; Renal function; Renal glomerular disease; Reporting; Research; Role; Second Messenger Systems; Signal Transduction; Staining method; Stains; Stimulus; System; T-Cell Activation; Testing; Time; Transgenes; Transgenic Mice; Transgenic Organisms; Trauma; Urine; base; calcineurin phosphatase; disease phenotype; extracellular; gain of function mutation; mutant; non-genetic; novel; nuclear factors of activated T-cells; overexpression; podocyte; premature; second messenger; slit diaphragm; synaptopodin; transcription factor

DESCRIPTION (provided by applicant): Chronic kidney disease (CKD) is a growing worldwide public health concern. Over 11% of adults living in the US are estimated to suffer from CKD, which leads to a diminished quality of life, financial health burden and premature death. Aberrant calcium signaling has been implicated in many scenarios of kidney disease and glomerular damage. Gain of function mutations in TRCP6 calcium channels can lead to alterations in proper podocyte morphology and the loss of the glomerular filter leading to loss of proteins into the urine (proteinura). Additionally, increases in intracellular calcium in the podocyte occur under other non-genetic insults such as increases in blood pressure, bacterial infection, and trauma. The calcium sensitive phosphatase calcineurin is activated in the presence of calcium, and our group has demostrated that constitutive activation of calcineurin leads to proteinuria. However, to date calcineurins canonical downstream target, the transcription factor nuclear factor of activated T-cells (NFAT), has not been well characterized for its role in changes that lead to disease phenotypes in the kidney. We have developed an animal model where the transcription factor, NFAT, is constitutively active in the podocyte in the presence of doxycycline. These animals develop profound proteinuria within fours days of doxycycline exposure and display foot process effacement upon analysis with electron microscopy. Our preliminary data also show that animals on prolonged doxycycline exposure (2 months) are unable to revert to normal podocyte morphology and glomerular filter function once the doxycycline is removed and normal animal chow is re-introduced. Interestingly, the glomerulus appears normal under histological techniques such as hematoxylin and eosin (H+E) staining and periodic acid Schiff staining (PAS). The proteinuric phenotype and podocyte foot process effacement of our animals coupled with the lack of observed pathology on H+E and PAS is reminiscent of the pathology of patients with Minimal Change Disease (MCD). The goals of the proposed study are two-fold. One, we intend to identify the NFAT target genes in our animal model that are responsible for the acute induction of proteinuria and recapitulate expression of those genes in vitro to assess possible changes in the podocyte. Two, we aim to completely characterize our animal model, both histologically and genetically, over several time courses of doxycycline exposure in comparison to MCD patient profiles. It is the hope that downstream targets of NFAT can be identified for the proteinuric phenotype of our animals and to provide the scientific community with an animal model for a debilitating disease. PUBLIC HEALTH RELEVANCE: Chronic kidney disease (CKD) affects over 11% of the US population, and accounts for nearly $60 billion in healthcare spending annually. Aberrant calcium signaling has been implicated in many scenarios of kidney disease and glomerular damage. Nuclear factor of activated T-cells (NFAT), a transcription factor, is activated upon increases in intracellular calcium. However, NFAT target genes remain un-characterized for their role in disease phenotypes in the kidney. Our research aims to identify NFAT target genes associated with disease phenotypes in the hope that new drug targets can be identified to ameliorate proteinuria in CKD patients.

描述（由申请人提供）：慢性肾脏疾病（CKD）在全球范围内不断增长。据估计，居住在美国的成年人中有11％的成年人患有CKD，这导致生活质量，财务健康负担和过早死亡的质量下降。异常的钙信号传导与肾脏疾病和肾小球损伤的许多情况有关。 TRCP6钙通道中功能突变的增益会导致适当的足细胞形态的改变以及肾小球滤波器的丧失，从而导致蛋白质损失到尿液中（proteinura）。另外，在其他非遗传损伤（例如血压，细菌感染和创伤）等其他非遗传损伤下，足细胞的细胞内钙增加。钙敏感的磷酸酶钙调蛋白在钙的存在下被激活，我们的组已解释了钙调蛋白的组成型激活导致蛋白尿。然而，迄今为止，钙调蛋白的下游靶标，即活化T细胞（NFAT）的转录因子核因子（NFAT），其在导致肾脏疾病表型的变化中的作用尚未得到很好的特征。我们已经开发了一种动物模型，其中转录因子NFAT在强力霉素的情况下在足细胞中具有组成性活性。这些动物在强力霉素暴露的四天内发展出深刻的蛋白尿，并在用电子显微镜分析后显示脚步过程。我们的初步数据还表明，长时间的强力霉素暴露（2个月）的动物无法恢复到正常的足细胞形态和肾小球滤波器功能，一旦去除多西环素并重新引入了正常的动物肉。有趣的是，在组织学技术（例如苏木精和曙红（H+E）染色和周期性酸Schiff染色（PAS））中，肾小球看起来正常。我们的动物的蛋白尿表型和足细胞脚步过程以及H+E和PAS上观察到的病理缺乏病理的效果使人联想到最小变化疾病（MCD）的患者的病理学。拟议的研究的目标是两个方面。第一，我们打算在动物模型中识别NFAT靶基因，这些基因负责急性诱导蛋白尿，并在体外概括这些基因的表达，以评估足细胞的可能变化。第二，与MCD患者概况相比，我们的目标是在组织学和遗传学上完全表征我们的动物模型。希望可以为我们动物的蛋白尿表型确定NFAT的下游靶标，并为科学界提供一种使人衰弱的疾病模型。 公共卫生相关性：慢性肾脏疾病（CKD）影响美国人口的11％以上，每年占医疗保健支出近600亿美元。异常的钙信号传导与肾脏疾病和肾小球损伤的许多情况有关。激活的T细胞（NFAT）的核因子是转录因子，随着细胞内钙的增加而激活。然而，NFAT靶基因在肾脏中的疾病表型中的作用仍然没有表征。我们的研究旨在鉴定与疾病表型相关的NFAT靶基因，希望可以鉴定出新的药物靶标可改善CKD患者的蛋白尿。