Hackett Tillie-Louise, Shaheen Furquan, Johnson Andrew, Wadsworth Samuel, Pechkovsky Dmitri V, Jacoby David B, Kicic Anthony, Stick Stephen M, Knight Darryl A
James Hogg iCAPTURE Centre for Cardiovascular and Pulmonary Disease, St Paul's Hospital, Vancouver, British Columbia, Canada.
Stem Cells. 2008 Oct;26(10):2576-85. doi: 10.1634/stemcells.2008-0171. Epub 2008 Jul 24.
The airway epithelium is the first line of contact with the inhaled external environment and is continuously exposed to and injured by pollutants, allergens, and viruses. However, little is known about epithelial repair and in particular the identity and role of tissue resident stem/progenitor cells that may contribute to epithelial regeneration. The aims of the present study were to identify, isolate, and characterize side population (SP) cells in human tracheobronchial epithelium. Epithelial cells were obtained from seven nontransplantable healthy lungs and four asthmatic lungs by pronase digestion. SP cells were identified by verapamil-sensitive efflux of the DNA-binding dye Hoechst 33342. Using flow cytometry, CD45(-) SP, CD45(+) SP, and non-SP cells were isolated and sorted. CD45(-) SP cells made up 0.12% +/- 0.01% of the total epithelial cell population in normal airway but 4.1% +/- 0.06% of the epithelium in asthmatic airways. All CD45(-) SP cells showed positive staining for epithelial-specific markers cytokeratin-5, E-cadherin, ZO-1, and p63. CD45(-) SP cells exhibited stable telomere length and increased colony-forming and proliferative potential, undergoing population expansion for at least 16 consecutive passages. In contrast with non-SP cells, fewer than 100 CD45(-) SP cells were able to generate a multilayered and differentiated epithelium in air-liquid interface culture. SP cells are present in human tracheobronchial epithelium, exhibit both short- and long-term proliferative potential, and are capable of generation of differentiated epithelium in vitro. The number of SP cells is significantly greater in asthmatic airways, providing evidence of dysregulated resident SP cells in the asthmatic epithelium. Disclosure of potential conflicts of interest is found at the end of this article.
气道上皮是与吸入的外部环境接触的第一道防线，不断受到污染物、过敏原和病毒的侵害和损伤。然而，关于上皮修复，尤其是可能有助于上皮再生的组织驻留干细胞/祖细胞的身份和作用，我们知之甚少。本研究的目的是鉴定、分离和表征人气管支气管上皮中的侧群（SP）细胞。通过胰蛋白酶消化从七个不可移植的健康肺和四个哮喘肺中获取上皮细胞。通过维拉帕米敏感的DNA结合染料Hoechst 33342外排来鉴定SP细胞。使用流式细胞术分离并分选CD45(-) SP、CD45(+) SP和非SP细胞。CD45(-) SP细胞在正常气道上皮细胞总数中占0.12%±0.01%，但在哮喘气道上皮中占4.1%±0.06%。所有CD45(-) SP细胞对上皮特异性标志物细胞角蛋白-5、E-钙黏蛋白、紧密连接蛋白-1和p63均呈阳性染色。CD45(-) SP细胞表现出稳定的端粒长度，具有增加的集落形成和增殖潜力，能够连续传代至少16次进行群体扩增。与非SP细胞相比，在气液界面培养中，少于100个CD45(-) SP细胞就能产生多层分化的上皮。SP细胞存在于人气管支气管上皮中，具有短期和长期增殖潜力，并且能够在体外产生分化的上皮。哮喘气道中SP细胞的数量明显更多，这为哮喘上皮中驻留SP细胞失调提供了证据。潜在利益冲突的披露见本文末尾。
