Long term expandable mouse and human induced nephron progenitor cells enable organoid modeling of kidney maturation, plasticity and disease

Nephron progenitor cells (NPCs) self-renew and differentiate into nephrons, the functional unit of the kidney. Here, manipulation of p38 and YAP activity allowed for long-term clonal expansion of primary mouse and human NPCs, and induced NPCs (iNPCs) from human pluripotent stem cells. Molecular analyses demonstrated cultured iNPCs resemble closely primary human NPCs. iNPCs generated nephron organoids with minimal off-target cell types and enhanced maturation of podocytes relative to published human kidney organoid protocols. Surprisingly, NPC culture medium uncovered plasticity in human podocyte programs, enabling podocyte reprogramming to an NPC-like state. Scalability and ease of genome-editing facilitated genome-wide CRISPR screening in NPC culture, uncovering novel genes associated with kidney development and dis-ease. Further, NPC-directed modeling of autosomal-dominant polycystic kidney disease (ADPKD) identified a small molecule inhibitor of cystogenesis. These findings highlight a broad application for the reported iNPC platform in the study of kidney development, disease, plasticity, and regeneration.

肾祖细胞（Nephron progenitor cells, NPCs）具备自我更新能力，可分化为肾脏的功能单位——肾单位。本研究通过调控p38与YAP的活性，实现了原代小鼠及人肾祖细胞的长期克隆扩增，同时可由人类多能干细胞诱导生成诱导性肾祖细胞（induced NPCs, iNPCs）。分子分析结果显示，体外培养的诱导性肾祖细胞与原代人肾祖细胞高度相似。相较于已发表的人类肾脏类器官构建方案，利用该体系生成的肾单位类器官仅含极少脱靶细胞类型，且可显著促进足细胞的成熟。令人意外的是，该肾祖细胞培养条件揭示了人类足细胞程序的可塑性，能够将足细胞重编程为肾祖细胞样状态。依托该体系的可扩展性与便捷的基因编辑操作，研究团队在肾祖细胞培养中完成了全基因组CRISPR筛选，鉴定出一批与肾脏发育及疾病相关的新基因。此外，基于诱导性肾祖细胞构建的常染色体显性遗传性多囊肾病（autosomal-dominant polycystic kidney disease, ADPKD）模型，筛选得到一种可抑制囊泡形成的小分子抑制剂。上述研究成果凸显了本报告所报道的诱导性肾祖细胞平台在肾脏发育、疾病、细胞可塑性及再生研究中的广泛应用前景。