Division of Laboratory Medicine, Nevada Cancer Institute, 1 Breakthrough Way, Las Vegas, NV 89135, USA.
Differentiation. 2011 Sep;82(2):89-98. doi: 10.1016/j.diff.2011.05.001. Epub 2011 May 18.
Induced pluripotent stem (iPS) cells are derived from reprogrammed somatic cells and are similar to embryonic stem (ES) cells in morphology, gene/protein expression, and pluripotency. In this study, we explored the potential of iPS cells to differentiate into alveolar Type II (ATII)-like epithelial cells. Analysis using quantitative real time polymerase chain reaction and immunofluorescence staining showed that pulmonary surfactant proteins commonly expressed by ATII cells such as surfactant protein A (SPA), surfactant protein B (SPB), and surfactant protein C (SPC) were upregulated in the differentiated cells. Microphilopodia characteristics and lamellar bodies were observed by transmission electron microscopy and lipid deposits were verified by Nile Red and Periodic Acid Schiff staining. C3 complement protein, a specific feature of ATII cells, was present at high levels in culture supernatants demonstrating functionality of these cells in culture. These data show that the differentiated cells generated from iPS cells using a culture method developed previously (Rippon et al., 2006) are ATII-like cells. To further characterize these ATII-like cells, we tested whether they could undergo epithelial to mesenchymal transition (EMT) by exposure to drugs that induce lung fibrosis in mice, such as bleomycin, and the combination of transforming growth factor beta1 (TGF(b1)) and epidermal growth factor (EGF). When the ATII-like cells were exposed to either bleomycin or a TGF(b1)-EGF cocktail, they underwent phenotypic changes including acquisition of a mesenchymal/fibroblastic morphology, upregulation of mesenchymal markers (Col1, Vim, a-Sma, and S100A4), and downregulation of surfactant proteins and E-cadherin. We have shown that ATII-like cells can be derived from skin fibroblasts and that they respond to fibrotic stimuli. These cells provide a valuable tool for screening of agents that can potentially ameliorate or prevent diseases involving lung fibrosis.
诱导多能干细胞（iPS 细胞）来源于重编程的体细胞，在形态、基因/蛋白表达和多能性方面与胚胎干细胞（ES 细胞）相似。在这项研究中，我们探讨了 iPS 细胞分化为肺泡 II 型（ATII）样上皮细胞的潜力。定量实时聚合酶链反应和免疫荧光染色分析显示，ATII 细胞中常见的肺表面活性蛋白如表面活性蛋白 A（SPA）、表面活性蛋白 B（SPB）和表面活性蛋白 C（SPC）等在分化细胞中上调。透射电子显微镜观察到微丝足特征和板层小体，尼罗红和过碘酸希夫染色验证了脂质沉积。C3 补体蛋白是 ATII 细胞的一个特征，在培养上清中高水平存在，证明这些细胞在培养中具有功能。这些数据表明，使用先前开发的培养方法（Rippon 等人，2006）从 iPS 细胞中产生的分化细胞是 ATII 样细胞。为了进一步表征这些 ATII 样细胞，我们测试了它们是否可以通过暴露于在小鼠中诱导肺纤维化的药物（如博来霉素）以及转化生长因子β1（TGF(b1)）和表皮生长因子（EGF）的组合来发生上皮间质转化（EMT）。当 ATII 样细胞暴露于博来霉素或 TGF(b1)-EGF 鸡尾酒时，它们经历了表型变化，包括获得间充质/成纤维细胞形态、间充质标志物（Col1、Vim、α-Sma 和 S100A4）上调以及表面活性蛋白和 E-钙黏蛋白下调。我们已经表明，ATII 样细胞可以从皮肤成纤维细胞中获得，并且它们对纤维化刺激有反应。这些细胞为筛选可能改善或预防涉及肺纤维化的疾病的药物提供了有价值的工具。
