p63+/Krt5+ Distal Airway Stem Cells are Essential for Lung Regeneration (before and after in vitro differentiation). Mus musculus

The possibility of lung regeneration has been long discounted due to the irreversible nature of chronic lung diseases. However, patients who sustain massive loss of lung tissue during acute infections often recover full pulmonary function. Correspondingly, we previously demonstrated lung regeneration in mice following H1N1 influenza virus infection and implicated p63+Krt5+ distal airway stem cells, or DASCp63/Krt5, in this process. We show here that rare, preexisting DASCp63/K5 undergo a proliferative expansion in response to influenza and lineage-trace to nascent alveoli assembled at sites of interstitial inflammation. We also show that the ablation of DASCp63/Krt5 in vivo prevents the regeneration of lung tissue following influenza leading to pre-fibrotic lesions and deficient oxygen exchange. Finally, we demonstrate that exogenously cloned and propagated DASCp63/Krt5 readily contribute to lung regeneration following transplantation. The transplanted DASC ameliorated influenza-induced lung injury. These data suggest that DASCp63/K5 are required for lung regeneration and may have therapeutic utility in acute and chronic lung diseases. Overall design: Stem cells before and after in vitro differentiation were subjected to whole genome microarray analysis. Duplicates were included for each sample. We used the Affymetrix Mouse Exon 1.0 ST platform

长期以来，由于慢性肺部疾病具有不可逆性，肺部再生的可能性曾被广泛忽视。然而，在急性感染期间出现大量肺组织丢失的患者，往往能够恢复全部肺功能。
相应地，我们此前已证实H1N1流感病毒感染后的小鼠可发生肺部再生，并将p63+Krt5+远端气道干细胞（distal airway stem cells, DASCp63/Krt5）与该过程相关联。
本研究显示，罕见的预先存在的DASCp63/K5会在流感病毒感染的刺激下发生增殖扩张，经谱系追踪证实其可迁移至间质炎症部位并组装形成新生肺泡。
我们还发现，体内敲除DASCp63/Krt5会阻断流感感染后的肺组织再生，进而引发前纤维化病变并导致氧交换功能受损。
最后，我们证实体外克隆并扩增的DASCp63/Krt5在移植后可有效参与肺部再生过程，移植后的DASC可缓解流感诱导的肺损伤。
上述数据表明，DASCp63/K5是肺部再生所必需的细胞群，或可在急性与慢性肺部疾病中展现治疗应用价值。
实验设计：对体外分化前后的干细胞进行全基因组芯片分析，每个样本均设置生物学重复。本研究采用Affymetrix Mouse Exon 1.0 ST芯片平台开展检测。