Intercalated Cells of the Distal Nephron Defend the Urinary System

远端肾单位的闰细胞保护泌尿系统

• 批准号: 8279970
• 负责人: Neal Paragas
• 金额: $ 9万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8279970
• 关键词: ATP phosphohydrolase; Acute; Acute Renal Failure with Renal Papillary Necrosis; Animals; Anti-Bacterial Agents; Automobile Driving; Bacteria; Binding; Bladder; Cell Count; Cell Lineage; Cell physiology; Cells; Chronic; Cisplatin; Clinical; Complement; Data; Dependence; Development; Diagnosis; Diet; Diet Modification; Disease; Distal; Enterobactin; Epithelial; Escherichia coli; Evaluation; Exposure to; Focal Infection; Gelatinase A; Genetic; Genitourinary system; Gram-Negative Bacteria; Grant; Growth; HIV; Hospitals; Host Defense Mechanism; Hour; Infection; Injection of therapeutic agent; Injury; Intercalated Cell; Iron; Kidney; Kidney Diseases; Kidney Transplantation; Knock-out; Knockout Mice; Label; Ligation; Link; Mediating; Medicine; Modeling; Modification; Molecular; Mus; Natural Immunity; Nature; Nephrons; Obstruction; Pathway interactions; Pattern; Physicians' Offices; Population; Proteins; Public Health; Reporter; Research Personnel; Resources; Sepsis; Shock; Siderophores; Signal Pathway; Signal Transduction; Site; Source; Stimulus; Taxes; Techniques; Testing; Therapeutic; Time; Tubular formation; Urinary system; Urinary tract; Urinary tract infection; Uropathogenic E. coli; Visit; Woman; artery occlusion; base; cost; hensin; in vivo; kidney cell; kidney epithelial cell; men; mouse model; novel; pathogenic bacteria; promoter; prophylactic; renal artery; septic; transcription factor; urinary

DESCRIPTION (provided by applicant): Urogenital tract infection is highly prevalent disease that annually afflicts more than 250 million people worldwide, with 90% of these infections caused by gram negative E. coli. We believe that the uroepithelia of the distal tubule detects and secretes a bacteriostatic molecule called neutrophil gelatinase-associated lipocalin (NGAL). We have shown that urinary NGAL (uNGAL) is expressed at mg/L levels after either septic or aseptic diseases of the kidney (Paragas, Nature Medicine 2011) and has two potential functions, epithelial growth and/or bacteriostasis. NGAL is critical to innate immunity because it binds siderophores which bacteria require to import iron. We were surprised to find that uNGAL was secreted specifically by the Intercalated Cell of the distal tubule (Paragas, Nature Medicine, 2011). Here we will examine hypothesis that an unrecognized function of the distal tubular cells of the kidney is to deliver the bacteriostatic protein, NGAL to the bladder from the alpha Intercalated Cell. We believe that NGAL is sufficient to inhibit iron acquisition from the urinary milieu as a previously unrecognized means to control bacterial growth. We will test this function in the urinary tract using a model of localized infection, transurethral bacterial injection, a wel characterized mouse model of urinary tract infections (UTI). We will determine whether the intercalated cells are sufficient and necessary to inhibit a pathogenic strain of E. coli (CFT073) from colonizing the bladder by secreting NGAL. First we will examine the molecular actions of NGAL by studying whether its inhibition of bacterial growth depends on the expression of Enterochelin (Ent), the cognate siderophore of NGAL as well as the recognition sites for Ent in the NGAL calyx. Next we will test whether dietary and genetic modifications of distal tubular cells leads to more or less severe UTIs. We examine whether intercalated cells are necessary for NGAL secretion in a UTI using genetically modified mouse models. Finally we will use reporter mice to immuno-dissect the kidney to generate pure populations of distal tubular cells by FACS for ChiP analysis of NGAL transcription factors. These data are of great significance to the millions of people who suffer from acute and chronic urinary tract infections worldwide and they may permit the development of novel bacteriostatic therapeutics based on NGAL to complement antibacterial agents. PUBLIC HEALTH RELEVANCE: Urinary tract infections (UTIs) are one of the most prevalent and resource taxing diseases in the USA with an annual cost of $3.5 billion for evaluation and treatment. In 2000 there were an estimated 11.02 million visits (2.05 million men; 8.97 million women) to a physician's office or hospital with UTI listed as any diagnosis. Uropathogenic E. coli (UPEC) represent 70-95% of all cases of uncomplicated UTI. Therefore the study of how the urogenital tract defends itself from pathogenic bacterial invasion and colonization is an important public health concern.

描述（由申请人提供）：泌尿生殖道感染是高度普遍的疾病，每年都会在全球范围内遭受超过2.5亿人的影响，其中90％是由革兰氏阴性大肠杆菌引起的。我们认为，远端小管的尿中心检测并分泌一种称为中性粒细胞明胶酶相关的脂肪蛋白（NGAL）的抑菌分子。我们已经表明，肾脏ngal（UNGAL）在肾脏或无菌疾病后以Mg/L水平表达（Paragas，Nature Medicine 2011），并且具有两种潜在功能，即上皮生长和/或菌落。 NGAL对于先天免疫至关重要，因为它结合了细菌需要进口铁的铁载体。我们很惊讶地发现，Ungal是由远端小管的插入细胞专门分泌的（Paragas，Nature Medicine，2011年）。在这里，我们将研究假设，即肾脏的远端管状细胞无法识别的功能是将抑菌蛋白（NGAL）从α插入的细胞中输送到膀胱。我们认为，NGAL足以抑制从泌尿环境中获得铁的习得，这是一种先前无法识别的方法来控制细菌生长。我们将使用局部感染，尿道细菌注射模型在尿路中测试该功能，这是一种尿路感染（UTI）的WEL特征的小鼠模型。我们将确定插入的细胞是否足够且需要通过分泌Ngal抑制大肠杆菌（CFT073）的致病菌株（CFT073）。首先，我们将通过研究其对细菌生长的抑制是否取决于NGAL（ENT）的表达，NGAL的同源辅助以及NGAL Calyx中ENT的识别位点来检查NGAL的分子作用。接下来，我们将测试远端管状细胞的饮食和遗传修饰会导致或多或少严重的UTI。我们检查了使用转基因的小鼠模型在UTI中进行NGAL分泌是否需要进行插入的细胞。最后，我们将使用报告基因小鼠免疫肾脏，通过FACS通过FACS来产生纯远端管细胞的种群，以分析NGAL转录因子。这些数据对于全球遭受急性和慢性尿路感染的数百万人具有重要意义，它们可能允许基于NGAL的新型抑菌治疗剂的发展来补充抗菌剂。 公共卫生相关性：尿路感染（UTI）是美国最普遍，最普遍的资源征税疾病之一，评估和治疗的年成本为35亿美元。在2000年，估计有1,102万次访问（205万男性； 897万名女性）对医师办公室或医院进行了uti列为任何诊断。肝病大肠杆菌（UPEC）占所有简单UTI病例中的70-95％。因此，关于泌尿生殖道如何捍卫自己免受致病细菌侵袭和殖民化的研究是一个重要的公共卫生问题。