Role of Tamm-Horsfall Protein in Urinary Tract Defense

Tamm-Horsfall 蛋白在尿路防御中的作用

• 批准号: 8785878
• 负责人: XUE-RU WU
• 金额: $ 8.39万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-01-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8785878
• 关键词: Acute; Acute Renal Failure with Renal Papillary Necrosis; Apatites; Apical; Apoptosis; Biological Process; Blood; Calcinosis; Calcium Oxalate; Calculi; Caveolins; Cells; Chemicals; Clathrin; Cultured Cells; Defect; Deposition; Development; Diagnosis; Disease; Employee Strikes; Endocytosis; Endoplasmic Reticulum; Epithelial Cells; Escherichia coli; Exhibits; Failure; Foundations; Funding; Future; Gene Mutation; Genetic Engineering; Genetically Engineered Mouse; Goals; Health; Human; Hydroxyapatites; Hyperoxaluria; Hyperuricemia; Inflammation; Inherited; Injury; Kidney; Kidney Calculi; Kidney Diseases; Kidney Failure; Kidney Papilla; Knockout Mice; Knowledge; Lead; Limb structure; Location; Lysosomes; Molecular; Molecular Chaperones; Mus; Mutation; Names; Nephrolithiasis; Papillary; Pathway interactions; Patients; Point Mutation; Protein Deficiency; Proteins; Renal function; Role; Series; Specialized Epithelial Cell; Specificity; Spectrum Analysis; Staging; Stress; Structure of ascending limb of Henle' s loop; Testing; Therapeutic; Thick; Transgenic Mice; Transgenic Model; Transgenic Organisms; Transmission Electron Microscopy; Tubular formation; UMOD gene; Uric Acid; Urinary tract; Urinary tract infection; Urine; Ursidae Family; Wild Type Mouse; absorption; calcification; calcium phosphate; cytokine; cytotoxic; cytotoxicity; design; genome wide association study; human disease; hypercalciuria; improved; in vivo; insight; interstitial; laser capture microdissection; macromolecule; mouse model; mutant; osteopontin; prevent; response; small molecule; spatial relationship; tandem mass spectrometry; uptake; urinary

DESCRIPTION (provided by applicant): Of all the proteins in human urine, Tamm-Horsfall protein (abbreviated as THP; also named uromodulin) is by far the most abundant. THP is made by kidneys' functionally specialized epithelial cells comprising the thick ascending limb of loop o Henle. Despite its abundance, kidney-specificity and evolutionary conservation, questions about THP's function(s) remain. During the last funding period, we have made major progress in understanding not only the in vivo biological functions of THP, but also its involvement in kidney diseases. Our approach has been to generate, using genetic engineering, knockout (KO) mice deficient for THP or transgenic mice expressing a point mutation of THP. We found that the THP KO mice are highly prone to experimental urinary tract infections by type 1-fimbriated E. coli; that they spontaneously develop intra-renal calcification consisting of calcium phosphate in the interstitial space of the renal papillae; and that they are more susceptible to experimental acute kidney injury than their wild-type counterparts. Additionally, we found that the transgenic mice expressing a THP mutation exhibit marked defects in tubular function and hyperuricemia. Importantly, the intra-renal calcification and hyperuricemia observed in our mouse models bear striking resemblances to certain types of idiopathic kidney stones and hereditary hyperuricemic nephropathies in humans, respectively. The main goal of this renewal proposal is to significantly expand and deepen our understanding of the molecular and cellular mechanisms whereby defects of THP lead to human-relevant disease conditions. Specifically, we will investigate how interstitial calcification in THP KO mice originate and evolve in a spatial and temporal manner by performing ultra-structural and chemical and protein composition analyses. We will examine how renal epithelial cells uptake the intratubular crystals and how this leads to cytotoxicity. We will determine whether formation of bona-fide kidney stones in THP KO mice relies on urinary super saturation of calcium phosphate or calcium oxalate by generating compound, genetically engineered mice that naturally develop these conditions. Finally, we will determine the in vivo effects of specific chemical chaperones in relieving the pathological effects of human-relevant THP mutation, utilizing the transgenic models we recently generated. Together, these four interconnected series of studies should have a major impact on understanding the biological functions and disease contributions of THP and offer insights into how THP-associated kidney diseases can be better managed clinically.

描述（由申请人提供）：在人尿液中的所有蛋白质中，Tamm-Horsfall蛋白（缩写为THP;也称为尿调素）是迄今为止最丰富的。THP是由肾脏功能特化的上皮细胞组成的，包括Henle袢的粗升支。尽管它的丰富性，肾脏特异性和进化保守性，THP的功能问题仍然存在。在上一个资助期内，我们不仅在了解THP的体内生物学功能方面取得了重大进展，而且还了解了其在肾脏疾病中的作用。我们的方法是使用基因工程产生THP缺陷的敲除（KO）小鼠或表达THP点突变的转基因小鼠。我们发现THP基因敲除小鼠极易发生1型菌毛大肠杆菌实验性尿路感染。大肠杆菌;它们自发地在肾乳头的间隙中形成由磷酸钙组成的肾内钙化;并且它们比它们的野生型对应物更容易受到实验性急性肾损伤的影响。此外，我们发现表达THP突变的转基因小鼠表现出明显的肾小管功能缺陷和高尿酸血症。重要的是，在我们的小鼠模型中观察到的肾内钙化和高尿酸血症分别与人类某些类型的特发性肾结石和遗传性高尿酸血症肾病具有显著的相似性。这项更新提案的主要目标是显着扩大和加深我们对THP缺陷导致人类相关疾病的分子和细胞机制的理解。具体来说，我们将研究如何在THP KO小鼠间质钙化起源和演变的空间和时间的方式进行超微结构和化学和蛋白质组成分析。我们将研究肾上皮细胞如何摄取小管内晶体以及这如何导致细胞毒性。我们将确定THP KO小鼠中真正肾结石的形成是否依赖于尿中磷酸钙或草酸钙的过饱和，通过产生自然发展这些条件的复合基因工程小鼠。最后，我们将利用我们最近建立的转基因模型，确定特定化学分子伴侣在减轻人类相关THP突变的病理效应方面的体内作用。总而言之，这四个相互关联的系列研究应该对了解THP的生物学功能和疾病贡献产生重大影响，并为如何在临床上更好地管理THP相关肾脏疾病提供见解。