Modulation of the podocyte actin network

足细胞肌动蛋白网络的调节

• 批准号: 241702976
• 负责人: Professor Dr. Tobias B. Huber
• 金额: --
• 依托单位: III. Medizinische Klinik und Poliklinik (Nephrologie, Rheumatologie - Nierentransplantation - Sektion Endokrinologie/Diabetologie)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/241702976?language=en
• 关键词: Modulation; podocyte; actin; network

The glomerular filtration barrier is composed of fenestrated endothelium, the glomerular basement membrane and highly specialized epithelial cells, namely podocytes. Dysfunction in any of these components presents the basis for glomerular diseases, which represent the main cause for chronic kidney disease and end stage renal kidney disease. Podocytes have a highly complex cellular morphology with numerous extensions and rely on a specialized cytoskeleton in order to maintain their morphology. Most forms of podocyte injury are characterized by a restructuring of the cytoskeleton and a retraction of podocyte foot processes. We propose that a comprehensive understanding of the podocyte cytoskeleton will allow the development of novel diagnostic as well as therapeutic interventions. In the previous funding period we could demonstrate the fundamental role of the N-WASP/Arp2/3 actin nucleation machinery to maintain morphology and function of podocytes. Based on these results we are aiming to answer the following questions: 1) How does the cortical and branched actin network interact with other cytoskeletal machineries (e.g. actomyosin)? Can these interactions be modulated by pharmacological interventions? 2) How does the podocyte actin cytoskeleton modulate the interaction with the glomerular basement membrane? Is this interplay involved in the prevention of podocyte detachment? 3) Which role do podocyte specific RhoGTPase modulators play for the integrity of the glomerular filtration barrier? The first two questions will be answered by the use of newly established in vitro models including 3D-culture systems, biophysical measurements and proteomics. The actin cytoskeleton is regulated via numerous signaling pathways including RhoGTPases and their upstream activators/inhibitors (GAPs and GEFs). We could already identify one podocyte specific GAP based on highly pure single cell isolation procedures and subsequent application of multi-plattform omics-technologies. We´ve generated a novel conditional knockout model to study the in vivo relevance of this podocyte specific GAP under physiological as well as pathological conditions. Moreover, we will perform further functional in vitro studies and proteomics to understand the precise role of this GAP for podocytes.

肾小球滤过屏障由有孔内皮、肾小球基底膜和高度特化的上皮细胞（即足细胞）组成。任何这些组分的功能障碍都是肾小球疾病的基础，而肾小球疾病是慢性肾病和终末期肾病的主要原因。足细胞具有高度复杂的细胞形态，具有许多延伸，并依赖于专门的细胞骨架以维持其形态。大多数形式的足细胞损伤的特征在于细胞骨架的重构和足细胞足突的回缩。我们建议，足细胞细胞骨架的全面了解将允许开发新的诊断以及治疗干预措施。在上一个资助期，我们可以证明N-WASP/Arp 2/3肌动蛋白成核机制在维持足细胞形态和功能方面的基本作用。基于这些结果，我们旨在回答以下问题：1）皮层和分支肌动蛋白网络如何与其他细胞骨架机制（如肌动球蛋白）相互作用？这些相互作用可以通过药物干预来调节吗？2)足细胞肌动蛋白细胞骨架如何调节与肾小球基底膜的相互作用？这种相互作用是否与足细胞脱落的预防有关？3)足细胞特异性RhoGT 3调节剂对肾小球滤过屏障的完整性起什么作用？前两个问题将通过使用新建立的体外模型来回答，包括3D培养系统，生物物理测量和蛋白质组学。肌动蛋白细胞骨架通过许多信号传导途径调节，包括RhoGTP酶及其上游激活剂/抑制剂（GAP和GEF）。基于高纯度的单细胞分离程序和随后的多平台组学技术的应用，我们已经可以鉴定出一种足细胞特异性GAP。我们已经产生了一种新的条件性敲除模型来研究这种足细胞特异性GAP在生理和病理条件下的体内相关性。此外，我们将进行进一步的体外功能研究和蛋白质组学研究，以了解这种GAP对足细胞的确切作用。