Disruption of the nuclear pore protein 93 in podocyte injury

足细胞损伤中核孔蛋白 93 的破坏

• 批准号: 527981127
• 负责人: Privatdozentin Dr. Daniela Anne Braun
• 金额: --
• 依托单位: Medizinische Klinik D: Allg. Innere Medizin und Notaufnahme sowie Nieren- und Hochdruckkrankheiten und Rheumatologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/527981127?language=en
• 关键词: Disruption; nuclear; pore; protein; 93

In previous studies, we have identified recessive mutations in NUP93 and six other genes that encode functionally-related structural proteins of the nuclear pore complex (NPC), a gated channel across the nuclear envelope of eukaryotic cells, as inherited causes of chronic glomerular kidney disease in paediatric patients. Surprisingly, despite the essential cellular function, ubiquitous expression, and high evolutionary conservation of NPCs, affected patients mostly presented with a kidney-specific phenotype, thus indicating a specific vulnerability of glomerular epithelial cells for disruption of NPCs. As specific therapies for most types of glomerular disease are lacking, further insights into the molecular pathogenesis are urgently need to improve therapy for affected patients. In preliminary studies, we have developed a mouse model with podocyte-specific knockout of the Nup93 gene that recapitulates the human phenotype of progressive glomerular kidney disease. In this proposal, we aim to elucidate the molecular mechanisms of podocyte injury due to NUP93 depletion. Therefore, we will utilize nephrocytes of Drosophila melanogaster as a model system to study the impact of pathogenic NUP93 mutations on nuclear pores, nuclear morphology, nuclear transport, and their consequences on the nephrocyte’s cytoskeleton and slit diaphragm. In the second aim, we will define the specific transcriptional alterations that drive podocyte injury and glomerular disease upon knockout of the Nup93 in mice by using single-nucleus RNA sequencing. Finally, we will implement a kidney organoid model from human induced pluripotent stem cells to study the impact of NUP93 mutations and pharmacological modulation of nuclear transport on podocyte development and differentiation. Further, newly identified molecular injury pattern will be validated in this human model system and will be tested as potential targets for therapy. In summary, our aim is to refine the role of NUP93 in glomerular development and disease and to understand the particular vulnerability of podocytes, specialized glomerular epithelial cells, to alterations in nuclear pores.

在以前的研究中，我们已经确定了NUP93和其他六个基因的隐性突变，这些基因编码核孔复合物（NPC）的功能相关结构蛋白，NPC是一种跨真核细胞核膜的门控通道，是儿科患者慢性肾小球肾病的遗传原因。令人惊讶的是，尽管NPCs具有基本的细胞功能、普遍的表达和高度的进化保守性，但受影响的患者大多呈现肾脏特异性表型，从而表明肾小球上皮细胞对NPC破坏的特异性脆弱性。由于大多数类型的肾小球疾病缺乏特异性治疗，迫切需要进一步了解分子发病机制，以改善受影响患者的治疗。在初步研究中，我们已经开发了一种足细胞特异性敲除Nup93基因的小鼠模型，该模型重现了人类进行性肾小球肾病的表型。在这个建议中，我们的目标是阐明足细胞损伤的分子机制，由于NUP93耗尽。因此，我们将利用黑腹果蝇的肾细胞作为模型系统来研究致病NUP93突变对核孔，核形态，核运输的影响，以及它们对肾细胞的细胞骨架和狭缝隔膜的后果。在第二个目标中，我们将通过使用单核RNA测序来定义在敲除小鼠中Nup93后驱动足细胞损伤和肾小球疾病的特定转录改变。最后，我们将从人诱导多能干细胞中构建肾类器官模型，以研究NUP93突变和核转运的药理学调节对足细胞发育和分化的影响。此外，新鉴定的分子损伤模式将在该人类模型系统中得到验证，并将作为治疗的潜在靶点进行测试。总之，我们的目的是细化NUP93在肾小球发育和疾病中的作用，并了解足细胞（特化的肾小球上皮细胞）对核孔改变的特殊脆弱性。