To determine whether adult kidney papillary label-retaining cells (pLRCs) are specialized precursors, we analyzed their transcription profile. Among genes overexpressed in pLRCs, we selected candidate genes to perform qPCR and immunodetection of their encoded proteins. We found that Zfyve27, which encodes protrudin, identified a subpopulation of pLRCs. With Zfyve27-CreERT2 transgenic and reporter mice we generated bitransgenic animals and performed cell-lineage analysis. Post tamoxifen, Zfyve27-CreERT2 marked cells preferentially located in the upper part of the papilla. These cells were low cycling and did not generate progeny even after long-term observation, thus they did not appear to contribute to kidney homeostasis. However, after kidney injury, but only if severe, they activated a program of proliferation, migration, and morphogenesis generating multiple and long tubular segments. Remarkably these regenerated tubules were located preferentially in the kidney medulla, indicating that repair of injury in the kidney is regionally specified. These results suggest that different parts of the kidney have different progenitor cell pools.

为了确定成人肾乳头状标记保留细胞（pLRCs）是否是专门的前体，我们分析了它们的转录特征。在pLRCs中过表达的基因中，我们选择了候选基因进行qPCR和对其编码蛋白的免疫检测。我们发现，编码protrudin的Zfyve27鉴定出pLRC的亚群。使用Zfyve27-CreERT2转基因和报告基因小鼠，我们产生了双转基因动物并进行了细胞谱系分析。他莫昔芬发布后，Zfyve27-CreERT2标记的细胞优先位于乳头上部。这些细胞周期低，即使长期观察也不会产生后代，因此它们似乎没有促进肾脏的稳态。但是，在肾脏受伤后，但只有在严重的情况下，它们才能激活增殖，迁移和形态发生程序，从而生成多个长管状段。值得注意的是，这些再生的肾小管优先位于肾脏髓质，这表明肾脏损伤的修复是区域性的。这些结果表明，肾脏的不同部分具有不同的祖细胞库。