Regeneration of endothelial cells in the kidney by intrinsic cells

应用的主要目的是鉴定与肾(肾小球和肾小管周围)微血管内皮损伤再生有关的细胞和信号通路，以便制定未来的治疗策略。除了对非典型HUS的补体抑制作用外，目前还没有针对肾内皮细胞的保护和保存或支持其修复的具体治疗方法。基本的研究思路将使用我们的选择性肾微血管病变内皮细胞损伤模型，并辅之以肾缺血再灌注模型。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品参与肾内皮细胞的再生。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重要但非排他性的作用。申请书中描述的实验能够表征和量化肾内皮细胞池的动态。这些实验将涉及的主要问题是，是否存在与局部内皮细胞增殖平行的非内皮(祖细胞)细胞池，并在需要肾内皮细胞再生时受到调控。一方面，这项赠款申请使用了其他肾小球细胞(肾素谱系细胞)再生的结果，另一方面检查/表征了细胞转分化和克隆性扩张的机制。通过使用几种不同的转基因小鼠，特别是使用可诱导的活性内皮报告系统(教授拉尔夫·亚当斯，Münster)，将通过流式细胞仪、免疫组织化学和活体显微镜对内皮细胞的再生进行纵向分析。尤其是针对成体内皮细胞、克隆性内皮细胞(脑弓细胞)、细胞周期激活细胞(Fucci小鼠)或由非内皮细胞(前体细胞)新生的内皮细胞，采用不同的报告系统和不同的活动标志进行不同的细胞示踪，将使人们对涉及的内皮再生机制有一个大致的了解。通过对不同的成体内皮细胞和祖细胞分别进行鉴定(细胞分选)以及在再生过程中克隆扩增内皮细胞，重要的细胞特征将被解码，这是后续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.