Linking endocytosis to cell signaling in proteinuria induced tubular apoptosis

将内吞作用与蛋白尿诱导的肾小管凋亡中的细胞信号传导联系起来

• 批准号: 8068852
• 负责人: Elif Erkan
• 金额: $ 13.93万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-05-15 至 2012-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8068852
• 关键词: Accounting; Adaptor Signaling Protein; Adolescent; Adult; Affect; Albumins; Apoptosis; Apoptotic; Arts; Atrophic; Binding; Biological Assay; Biotinylation; Cell Differentiation process; Cell Proliferation; Cell Survival; Cell model; Cells; Cellular biology; Cessation of life; Chronic Glomerulonephritis; Chronic Kidney Failure; Clathrin; Clinical; Cloning; Deterioration; Disabled Persons; Disease; Down-Regulation; End stage renal failure; Endocytosis; Epithelial Cells; Event; Fibrosis; Goals; Health; Human; Image; Impairment; In Vitro; Inflammatory; Injury; Kidney; Kidney Diseases; Knock-in Mouse; LDL-Receptor Related Protein 2; Lead; Learning; Ligand Binding; Link; Mediating; Mediator of activation protein; Medical; Mentors; Methods; Mitochondria; Modeling; Molecular; Monitor; Morbidity - disease rate; Nature; Nutrient; Outcome Measure; Pathologic; Pathway interactions; Patients; Phosphorylation; Physiologic pulse; Physiological; Plasma Proteins; Play; Prevention strategy; Principal Investigator; Process; Production; Prognostic Factor; Proteins; Proteinuria; Proto-Oncogene Proteins c-akt; Renal function; Renal glomerular disease; Role; Series; Signal Transduction; Site; Sorting - Cell Movement; Techniques; Testing; Therapeutic Intervention; Training; Tubular formation; cell injury; glomerular filtration; in vivo Model; knock-down; mortality; novel; prevent; protein complex; protein protein interaction; receptor; receptor mediated endocytosis; research study; response; tool; trafficking; uptake; yeast two hybrid system

DESCRIPTION (provided by applicant): Chronic glomerulonephritis is associated with progressive kidney disease in adults and adolescents. In glomerular disorders, high amounts of protein particularly albumin pass through the damaged glomerular filtration barrier. It has long been established that proteinuria is detrimental to kidneys and patients with heavy proteinuria show a rapid deterioration of their renal function. In the previous studies, the candidate showed that high concentrations of albumin, above the reabsorptive capacity of the proximal tubule cells, mimicking the nephrotic milieu result in apoptosis. Endocytosis of proteins and nutrients in the proximal tubule is regulated by a highly sophisticated machinery containing clathrin, receptors and adaptor proteins. The best described receptor-adaptor protein complex in the proximal tubule is megalin-disabled-2 (Dab2). Dab2 is also implicated in signal transduction events regulating cell proliferation and differentiation. The candidate proposes that there is an overlap between endocytosis and cell signaling event that mediate albumin induced apoptosis. Preliminary studies showed an interaction between the survival factor protein kinase B (PKB/Akt) and endocytic adaptor protein Dab2. The down regulation of this interaction associated with albumin-induced apoptosis allowed us to hypothesize that Dab2 is a key adaptor protein that regulates both apoptosis and endocytosis. The goal of this project is to elucidate the mechanism and implications of this interaction to cell survival. Thus in aim 1, the candidate will investigate the role of albumin endocytosis on Dab2-PKB interaction and the fate/trafficking of megalin/Dab2 with albumin overload. In aim 2, the candidate will study the role of Dab2 in albumin-induced apoptosis and the nature of Dab2-PKB interaction. Short-term goal of the candidate is to acquire further training that will enable her to learn the state-of-art cell biology techniques such as cloning, protein-protein interactions and confocal imaging under the guidance of her mentor Dr.Linton Traub. The long term objective is to discover therapeutic interventions that will halt the proteinuria induced progression of glomerular disease by investigating the molecular network of events that are associated with proximal tubule injury and albumin endocytosis. PUBLIC HEALTH RELEVANCE: Chronic glomerulonephritis is an important problem with high morbidity resulting in chronic renal failure. The degree of proteinuria correlates with the rate of progression. The main goal of this project is to dissect the mechanism of proteinuria induced kidney damage in an attempt to develop preventive strategies to halt progression of glomerular diseases.

描述（由申请人提供）： 慢性肾小球肾炎与成人和青少年的进行性肾脏疾病有关。在肾小球疾病中，大量蛋白质特别是白蛋白通过受损的肾小球滤过屏障。长期以来，人们已经确定蛋白尿对肾脏有害，并且具有大量蛋白尿的患者显示出其肾功能的迅速恶化。在先前的研究中，候选人表明，高浓度的白蛋白，高于近端小管细胞的重吸收能力，模拟肾病环境，导致细胞凋亡。近端小管中蛋白质和营养物质的内吞作用由包含网格蛋白、受体和衔接蛋白的高度复杂的机制调节。近端小管中最好描述的受体-衔接蛋白复合物是巨蛋白失能2（Dab 2）。Dab 2还涉及调节细胞增殖和分化的信号转导事件。该候选人提出，内吞作用和介导白蛋白诱导的细胞凋亡的细胞信号传导事件之间存在重叠。初步研究表明，生存因子蛋白激酶B（PKB/Akt）和内吞衔接蛋白Dab 2之间的相互作用。与白蛋白诱导的细胞凋亡相关的这种相互作用的下调允许我们假设Dab 2是调节细胞凋亡和内吞作用的关键衔接蛋白。该项目的目标是阐明这种相互作用对细胞存活的机制和影响。因此，在目标1中，候选人将研究白蛋白内吞作用对Dab 2-PKB相互作用的作用以及白蛋白超负荷的巨蛋白/Dab 2的命运/运输。在目标2中，候选人将研究Dab 2在白蛋白诱导的细胞凋亡中的作用以及Dab 2-PKB相互作用的性质。候选人的短期目标是获得进一步的培训，使她能够在导师林顿特劳布博士的指导下学习最先进的细胞生物学技术，如克隆，蛋白质-蛋白质相互作用和共聚焦成像。长期目标是通过研究与近端小管损伤和白蛋白内吞作用相关的事件的分子网络，发现将阻止蛋白尿诱导的肾小球疾病进展的治疗干预措施。 公共卫生相关性：慢性肾小球肾炎是一个重要的问题，发病率高，导致慢性肾衰竭。蛋白尿的程度与进展速度相关。本研究的主要目的是探讨蛋白尿导致肾脏损害的机制，并试图提出预防性策略来阻止肾小球疾病的进展。