Proximal tubule endocytosis in normal and nephrotic kidneys

正常和肾病肾脏的近端小管内吞作用

基本信息

批准号：
10132740
负责人：
Ora A Weisz
金额：
$ 45.21万
依托单位：
UNIVERSITY OF PITTSBURGH AT PITTSBURGH
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-04-16 至 2023-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10132740
关键词：
Acute Adaptor Signaling Protein Address Albumins Animal Model Apical Apoptosis Binding Blood Cell Culture System Cell Culture Techniques Cell membrane Cell physiology Cells Chronic Chronic Kidney Failure Complex Cultured Cells Cytoplasmic Tail Development Didelphidae Disabled Homolog 2 Protein Disease Endocytosis Enzymes Excretory function Filtration Glomerular Filtration Rate Human Impairment In Vitro Individual Injury Ion Transport Ions Kidney Kidney Diseases Knockout Mice LDL-Receptor Related Protein 2 Ligands Link Lipids Liquid substance Mediating Modeling Molecular Morphology Mus Nephrons Pathologic Pathway interactions Plasma Plasma Proteins Predisposition Proteins Proteinuria Proximal Kidney Tubules Recovery Renal function Research Role Sex Differences Signal Transduction Surface Testing Therapeutic Time Transmembrane Domain Tubular formation Urine Variant Water Work blood pressure regulation combat cytotoxic glomerular filtration in vivo intrinsic factor-cobalamin receptor kidney cell kidney cortex mouse model preservation prevent protein expression receptor response shear stress therapy design trafficking transcriptome sequencing uptake urinary

项目摘要

Abstract A major function of cells linking the proximal tubule (PT) of the kidney is to recover proteins that escape the glomerular filtration barrier to maintain a protein-free urine. Apical endocytosis in PT cells is acutely modulated by changes in fluid shear stress (FSS), presumably to enable efficient protein uptake over normal variations in glomerular filtration rate (GFR). The large multiligand receptors megalin and cubilin/amnionless (CUBAM) are expressed at the apical surface of PT cells and mediate the internalization of >50 different plasma proteins. Despite the critical role of the PT in reclaiming proteins from the ultrafiltrate, we know surprisingly little about how the cells lining this segment accommodate variations in filtered load to maintain a protein free urine. Fundamental issues, including how the robust PT apical endocytic pathway is developed and maintained, the individual role of megalin and CUBAM receptors in albumin uptake, how PT cells respond to changes in albumin concentration or tubular flow rate, and the fate of internalized albumin remain controversial. We have developed a new cell culture model that recapitulates morphological and functional features of PT cells in vivo necessary for efficient and rapidly modulated apical endocytosis of albumin. We will use these cells in conjunction with studies in mouse models to address the following questions about how PT cells respond to normal and pathologic variations in flow and filtered protein load: 1) How do PT cells develop and maintain a high capacity apical endocytic pathway? 2) How do megalin and CUBAM contribute to albumin uptake under normal and nephrotic conditions? 3) How does the PT respond endocytically to acute changes in GFR? and 4) How does endocytosis contribute to cytotoxic responses of PT cells during albumin overload?

抽象的连接肾脏近端小管（PT）的细胞的主要功能是恢复逃脱的蛋白质肾小球滤过屏障以保持无蛋白质尿液。 PT细胞中的根尖内吞作用急性由流体剪应力（FSS）的变化调节，大概是为了使有效的蛋白质吸收肾小球滤过率（GFR）的正常变化。大型多数受体Megalin和 Cubilin/amnionless（cubam）在PT细胞的顶部表面表达，并介导 > 50种不同的血浆蛋白的内在化。尽管PT在回收蛋白质中起着至关重要的作用从超滤液中，我们几乎不知道该节段的细胞如何容纳过滤负荷的变化以维持无蛋白质的尿液。基本问题，包括如何健壮 PT顶端内吞途径是开发和维护的，Megalin和Cubam的个体作用白蛋白摄取中的受体，PT细胞如何响应白蛋白浓度或管状流的变化速率和内在白蛋白的命运仍然有争议。我们已经开发了一种新的细胞文化概括为有效的体内PT细胞的形态和功能特征的模型和快速调节白蛋白的顶端内吞作用。我们将与研究结合使用这些细胞在鼠标模型中，以解决以下问题，有关PT细胞如何响应正常和流量和过滤蛋白质负荷的病理变异：1）PT细胞如何发展和维持高容量顶端内吞途径？ 2）Megalin和Cubam如何为白蛋白摄入做出贡献正常和肾病状况？ 3）PT对GFR的急性变化有何反应？ 4）在白蛋白过载期间，内吞作用如何导致PT细胞的细胞毒性反应？