Flow-stimulated endocytosis in the proximal tubule

近端小管中的流动刺激内吞作用

• 批准号: 9394003
• 负责人: Ora A Weisz
• 金额: $ 34万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-12-01 至 2018-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9394003
• 关键词: Actins; Acute; Albumins; Animal Model; Apical; Blood Volume; Cell Line; Cells; Chronic; Chronic Kidney Failure; Cilia; Clathrin; Cystinosis; Data; Defect; Dextrans; Diabetes Mellitus; Disease; Disease Pathway; Endocytosis; Enzymes; Equilibrium; Filtration; Glomerular Filtration Rate; Homeostasis; Hormones; Human; Impairment; In Situ; Individual; Injury; Ion Transport; Ions; Kidney; Kidney Diseases; Kidney Failure; LDL-Receptor Related Protein 2; Lead; Ligands; Link; Liquid substance; Mediating; Molecular; Molecular Weight; Morphology; Mus; Neurons; Oculocerebrorenal Syndrome; PKD2 protein; Pathogenesis; Pathway interactions; Patients; Phase; Phosphatidylinositols; Phosphoric Monoester Hydrolases; Plasma; Play; Prediabetes syndrome; Proteins; Proteinuria; Proximal Kidney Tubules; Recovery; Renal function; Research; Research Personnel; Role; Signal Transduction; Site; Sodium-Hydrogen Antiporter; Surface; Testing; Therapeutic Intervention; Translating; Tubular formation; Urine; Vitamins; Water; Wiskott-Aldrich Syndrome; Zebrafish; blood pressure regulation; cilium biogenesis; coated pit; combat; density; experimental study; extracellular; improved; insight; interest; intrinsic factor-cobalamin receptor; kidney cell; knock-down; metal poisoning; mouse model; novel; public health relevance; receptor; response; shear stress; small molecule; solute; therapeutic development; therapy design; uptake

DESCRIPTION (provided by applicant): The proximal tubule (PT) of the kidney is the primary site for reabsorption of ions, solutes, and filtered low molecular weight (LMW) proteins. PT cells acutely modulate ion transport capacity in respond to changes in fluid shear stress (FSS) that accompany alterations in glomerular filtration rate. This proposal is focused on understanding whether PT cells also adjust the capacity of megalin-and cubilin- mediated endocytosis of LMW proteins in response to altered demand. Defective uptake of these proteins leads to tubular proteinuria, which can eventually lead to renal failure. We have discovered that apical endocytosis of the megalin/cubilin ligand albumin as well as fluid phase markers is markedly increased upon exposure of PT cells to FSS. Moreover, primary cilia are required for this response. The aims of this proposal are to (1) determine how changes in FSS are transduced into effects on apical endocytosis and (2) determine whether defective modulation of flow-dependent endocytosis contributes to LMW proteinuria observed in animal models for Lowe Syndrome, an X- linked disorder that may involve defects in ciliogenesis. We have assembled an outstanding team of investigators with essential expertise to carry out this broad range of studies. The results of our experiments will provide key information about a newly discovered pathway that plays an essential role in maintaining kidney function.

描述（由申请人提供）：肾脏的近端小管（PT）是重吸收离子、溶质和过滤的低分子量（LMW）蛋白质的主要部位。 PT 细胞敏锐地调节离子转运能力，以响应伴随肾小球滤过率变化的流体剪切应力 (FSS) 的变化。该提案的重点是了解 PT 细胞是否也会调整巨蛋白和 cubilin 介导的 LMW 蛋白内吞作用的能力，以响应需求的变化。这些蛋白质的摄取缺陷会导致肾小管蛋白尿，最终导致肾衰竭。我们发现，当 PT 细胞暴露于 FSS 时，巨蛋白/cubilin 配体白蛋白以及液相标记的顶端内吞作用显着增加。此外，这种反应需要初级纤毛。该提案的目的是（1）确定 FSS 的变化如何转化为对顶端内吞作用的影响，以及（2）确定流依赖性内吞作用的缺陷调节是否会导致 Lowe 综合征动物模型中观察到的 LMW 蛋白尿，Lowe 综合征是一种可能涉及纤毛发生缺陷的 X 连锁疾病。我们组建了一支优秀的研究人员团队，拥有必要的专业知识来开展广泛的研究。我们的实验结果将提供有关新发现的途径的关键信息，该途径在维持肾功能中发挥重要作用。

项目成果

Ex vivo kidney slice preparations as a model system to study signaling cascades in kidney epithelial cells.

离体肾切片制剂作为研究肾上皮细胞信号级联的模型系统。

• DOI: 10.1016/bs.mcb.2019.04.017
• 发表时间: 2019
• 期刊: Methods in cell biology
• 作者: Saitta,Biagio;Jalili,MichaelF;Zohoorkari,Hamidreza;Rao,Renee;Hallows,KennethR;Baty,CatherineJ;Pastor-Soler,NuriaM
• 通讯作者: Pastor-Soler,NuriaM