Regeneration of endothelial cells in the kidney by intrinsic cells

该应用程序的主要目的是表征和鉴定负责肾脏（肾小球和小管周围）微血管内皮损伤再生的相关细胞和信号通路，以便制定未来的治疗策略。除了对非典型溶血性尿毒综合征的补体抑制外，目前还没有专门针对肾内皮细胞的保护和保存或支持其修复的治疗方法。我们将采用肾微血管病变的选择性内皮细胞损伤模型，并辅以肾缺血再灌注模型来检验基本的研究概念。由于之前非常复杂的动物实验，我们知道没有外源性细胞作为局部微血管内皮细胞的替代物参与肾内皮的再生。另一方面，局部增殖的成人内皮细胞似乎在再生过程中起着必不可少的作用，但不是唯一的作用。应用程序中描述的实验能够表征和量化肾内皮细胞池的动态。这些实验将与非内皮细胞（祖细胞）池是否与局部内皮细胞增殖平行存在并在需要肾内皮细胞再生时受到调节的主要问题联系起来。一方面，这项拨款申请使用了其他肾小球细胞（肾素系细胞）再生的发现，另一方面，研究/表征了细胞转分化和克隆扩增的机制。采用几种不同的转基因小鼠，特别是具有诱导活性的内皮细胞报告系统的小鼠（Prof. Ralph Adams, m.nster），通过流式细胞仪、免疫组织化学和活体显微镜对内皮细胞的再生进行了密切的纵向分析。特别是各种不同的细胞追踪程序，不同的报告系统和不同的活性迹象，用于成人内皮细胞，克隆衍生的（Brainbow），细胞周期激活的（Fucci小鼠）或由非内皮细胞（祖细胞）新生的内皮细胞，将使内皮再生机制的总体视图。通过分别表征不同的成人内皮细胞和祖细胞群体（细胞分选）以及再生过程中克隆扩增的内皮细胞，将解码重要的细胞特征，这是随后定向治疗调节的基础。

The major aim of the application is the characterization and identification of relevant cells and signal pathways being responsible for the regeneration of microvascular endothelial injury in the kidney (glomerular and peritubular) in order to develop therapeutic strategies in future. Besides complement inhibition in atypical HUS, there are no specific therapeutic approaches at the moment aiming at protection and preservation of renal endothelial cells respectively or supporting their reparation. The basic research concept will be examined using our selective endothelial cell injury model of renal microangiopathy and supplemented by the renal ischemia reperfusion model.Due to previous very complex animal experiments, we know that no extrinsic cells are involved as substitute of local microvascular endothelial cells for the regeneration of the renal endothelium. On the other hand, local proliferating adult endothelial cells seem to have an essential but not exclusive part in the regeneration process. The experiments described in the application are able to characterize and quantify the dynamic of the renal endothelial cell pool. These experiments will be connected with the main question whether a non-endothelial (progenitor) cell pool exists in parallel to the local endothelial cell proliferation and is regulated if renal endothelial cell regeneration is needed. On one hand this grant application uses findings of the regeneration of other glomerular cells (of renin lineage cells) and on the other hand examines/characterizes mechanisms of cellular transdifferentiation and clonal expansion. By using several different transgenic mice especially with the inducible active, endothelial reporter system (Prof. Ralph Adams, Münster), the cellular regeneration of the endothelium will be analyzed closely longitudinal by FACS, immunohistochemistry and intravital microscopy. Especially the variety of different cellular tracing procedures with different reporter systems and different activity signs for adult endothelial cells, clonally derived (Brainbow), cell cycle-activated (Fucci mice) or endothelial cells emerging by neogenesis from non-endothelial cells (progenitor cells) will enable a general view of the involved endothelial regeneration mechanisms. By characterization of different adult endothelial cell and progenitor cell populations respectively (cell sorting) as well as clonally expanding endothelial cells during the regeneration process, significant cellular signatures will be decoded which are the basis for subsequent directed therapeutic modulation.