Molecular mechanisms in Notch3-dependent immune cell infiltration, fibrogenic niche formation and kidney fibrosis

Notch3依赖性免疫细胞浸润、纤维化生态位形成和肾纤维化的分子机制

• 批准号: 178644716
• 负责人: Professor Dr. Peter Rene Mertens
• 金额: --
• 依托单位: Universitätsklinik für Nieren- und Hochdruckkrankheiten, Diabetologie und Endokrinologie
• 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/178644716?language=en
• 关键词: Molecular; mechanisms; Notch3; dependent; immune

Chronic kidney diseases affect about 10% of the general population and constitute a major burden to the health care system due to high costs and chronicity. In the majority of affected individuals a relentless decline of kidney function takes place. Underlying causes are diverse, ranging from arterial hypertension, hyperglycemia to autoimmune diseases. A close temporal and spatial link of kidney tissue damage with tubulointerstitial cell infiltration and an “activated” fibrogenic niche is frequently detected. The findings from our group identified receptors of the Notch family as pivotal regulators of kidney damage. Mice with genetic ablation of receptor Notch3 are protected from experimental kidney diseases. The fundamental role of receptor Notch3 for the tissue damage response is underscored by the findings of blunted integrin activation, less leukocyte transmigration and absent NF-B signaling. The project outline will address the following questions: (i) To which extent does receptor Notch3 perform exquisite tasks in leukocyte transmigration and activation of the fibrogenic niche in bone marrow chimeric animals? Are β1-integrin activation and Notch3 expression functionally linked with neutrophil transmigration? The cell-specific contribution of Notch3 to kidney damage will be clarified. Novel chimeric animal models will be established to reconstitute intracellular Notch3 signaling in specific cell subsets on an otherwise Notch3 knockout background. Phenotyping of animals for the inflammatory response and organ fibrosis will be performed following disease induction (UUO, I/R). The formation of the fibrogenic niche with crosstalk of cells that express tenascin-C or receptor Notch3 will be visualized for temporal changes and induction of partial epithelial-to-mesenchymal transition in tubular cells. (ii) Why do circulating Notch3 knockout immune cells not transmigrate into “inflamed” tissue? Experiments will scrutinize the Notch3-dependent interaction of immune cells adherent to endothelial cells. (iii) Does cell-specific blockade of receptor Notch3 in tubular or Gli1-positive cells improve the course of experimental kidney disease comparable to receptor Notch3 knockout animals? An intervention strategy is envisioned with delivery of adeno-associated as well as lentiviruses. Small interfering RNA will be introduced to specifically down-regulate receptor Notch3 expression in tubular and Gli-1 positive cells. In parallel, an expression system for soluble Notch3 decoy receptors will be set up.Overall, this grant application will deepen our understanding of chronic kidney disease pathophysiology centered around a key receptor molecule. Ultimately, the results will enable intervention strategies to combat inflammatory responses as well as organ fibrosis at the cellular level.

慢性肾病影响着大约 10% 的总人口，由于费用高且慢性，对医疗保健系统构成重大负担。在大多数受影响的个体中，肾功能会不断下降。潜在原因多种多样，从动脉高血压、高血糖到自身免疫性疾病。经常检测到肾组织损伤与肾小管间质细胞浸润和“激活的”纤维形成生态位之间存在密切的时间和空间联系。我们小组的研究结果确定了 Notch 家族的受体是肾脏损伤的关键调节因子。受体Notch3基因被消除的小鼠可以免受实验性肾脏疾病的影响。整合素激活减弱、白细胞迁移减少和 NF-κB 信号传导缺失的发现强调了受体 Notch3 在组织损伤反应中的基本作用。该项目大纲将解决以下问题：（i）受体Notch3在骨髓嵌合动物的白细胞迁移和纤维形成生态位激活中执行精细任务的程度如何？ β1-整合素激活和 Notch3 表达与中性粒细胞迁移有功能相关吗？ Notch3 对肾损伤的细胞特异性贡献将得到阐明。将建立新型嵌合动物模型，以在 Notch3 敲除背景下重建特定细胞亚群中的细胞内 Notch3 信号传导。将在疾病诱导（UUO、I/R）后对动物进行炎症反应和器官纤维化的表型分析。纤维化生态位的形成与表达生腱蛋白-C 或受体 Notch3 的细胞的串扰将被可视化，以实现时间变化并诱导肾小管细胞中部分上皮到间质的转变。 (ii) 为什么循环中的 Notch3 敲除免疫细胞不会迁移到“发炎”组织中？实验将仔细检查与内皮细胞粘附的免疫细胞之间依赖于 Notch3 的相互作用。 (iii) 与Notch3受体敲除动物相比，肾小管或Gli1阳性细胞中受体Notch3的细胞特异性阻断是否可以改善实验性肾病的病程？设想通过递送腺相关病毒和慢病毒来进行干预策略。将引入小干扰 RNA 以特异性下调肾小管细胞和 Gli-1 阳性细胞中受体 Notch3 的表达。与此同时，将建立可溶性Notch3诱饵受体的表达系统。总体而言，这项资助申请将加深我们对以关键受体分子为中心的慢性肾病病理生理学的理解。最终，这些结果将使干预策略能够在细胞水平上对抗炎症反应以及器官纤维化。