Airway basal cells are crucial for regeneration of the human lung airway epithelium and are believed to be important contributors to chronic obstructive pulmonary disease (COPD) and other lung disorders. To reveal how basal cells contribute to disease and to discover novel therapeutic targets, these basal cells need to be further characterized. In this study, we optimized a flow cytometry–based cell sorting protocol for primary human airway basal cells dependent on cell size and NGFR (nerve-growth factor receptor) expression. The basal cell population was found to be molecularly and functionally heterogeneous, in contrast to cultured basal cells. In addition, significant differences were found, such as KRT14 expression exclusively existing in cultured cells. Also, colony-forming capacity was significantly increased in cultured cells showing a clonal enrichment in vitro. Next, by single-cell RNA sequencing on primary basal cells from healthy donors and patients with Global Initiative for Chronic Obstructive Lung Disease stage IV COPD, the gene expression revealed a continuum ranging from healthy basal cell signatures to diseased basal cell phenotypes. We identified several upregulated genes that may indicate COPD, such as stress response–related genes GADD45B and AHSA1, together with with genes involved in the response to hypoxia, such as CITED2 and SOD1. Taken together, the presence of healthy basal cells in stage IV COPD demonstrates the potential for regeneration through the discovery of novel therapeutic targets. In addition, we show the importance of studying primary basal cells when investigating disease mechanisms as well as for developing future cell-based therapies in the human lung.

气道基底细胞对于人肺气道上皮的再生至关重要，并且被认为是慢性阻塞性肺病 (COPD) 和其他肺部疾病的重要原因。为了揭示基底细胞如何导致疾病并发现新的治疗靶点，需要进一步表征这些基底细胞。在这项研究中，我们根据细胞大小和 NGFR（神经生长因子受体）表达优化了基于流式细胞术的细胞分选方案，用于原代人气道基底细胞。与培养的基底细胞相比，发现基底细胞群在分子和功能上是异质的。此外，还发现了显着差异，例如KRT14仅存在于培养细胞中的表达。此外，培养细胞的集落形成能力显着增加，显示体外克隆富集。接下来，通过对来自健康供体和慢性阻塞性肺疾病 IV 期 COPD 全球倡议患者的原代基底细胞进行单细胞 RNA 测序，基因表达揭示了从健康基底细胞特征到患病基底细胞表型的连续性。我们确定了几个可能表明 COPD 的上调基因，如应激反应相关基因GADD45B和AHSA1，以及参与缺氧反应的基因，如CITED2和SOD1. 总之，在 IV 期 COPD 中健康基底细胞的存在证明了通过发现新的治疗靶点进行再生的潜力。此外，我们展示了在研究疾病机制以及在人类肺中开发未来基于细胞的疗法时研究原代基底细胞的重要性。