State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, P. R. China.
Cell Transplant. 2009;18(10):1093-109. doi: 10.3727/096368909X12483162197042. Epub 2009 Jun 22.
Multipotent mesenchymal stromal cells (MSCs) are a promising cell type for cell transplantation; however, their utilization remains limited until the availability of adequate alternative sources of MSCs and the thorough understanding of the biology of MSCs isolated from various sources are realized. Fetal lung has been identified as a rich source of MSCs. To explore the therapeutic potential of passaged fetal lung MSCs (FLMSCs), the present study evaluated their growth kinetics, telomere length, karyotype, immunophenotype, and the differentiation potential during in vitro expansion. FLMSCs could be easily amplified in vitro with no significant shorting of telomere length and had a normal karyotype. No significant differences between passage 5 or passage 25 were observed in the immunophenotype analysis using flow cytometry. Moreover, flow cytometry results provided the first demonstration, to our knowledge, that FLMSCs stably expressed pluripotent markers including Oct4, Nanog, Sox2, TRA-1-60, c-Myc, and SSEA-4 through 25 passages. In vitro differentiation studies as identified by confocal microscopy, flow cytometry, RT-PCR, and immunohistochemistry showed that FLMSCs had extended capacity of differentiating into mesodermal, ectodermal, and endodermal lineages, and that their potential for adipogenic, osteogenic, and chondrogenic differentiation may be maintained over 25 passages. Furthermore, osteogenic and chondrogenic differentiation was used as an indicator of their differentiation capability in vivo, as evidenced by ectopic bone and cartilage formation. In summary, these results suggest that FLMSCs are a primitive population and that their extensive in vitro expansion does not involve significant functional modification of the cells, including morphology, growth, karyotype, immunophenotype, and mesodermal differentiation potential. Hence, FLMSCs might constitute an attractive cell resource for cell transplantation to induce regeneration of damaged tissues/organs.
多能间充质干细胞（MSCs）是细胞移植有前途的细胞类型；然而，在获得足够的 MSCs 替代来源并彻底了解从各种来源分离的 MSCs 的生物学特性之前，它们的应用仍然受到限制。胎儿肺已被确定为 MSC 的丰富来源。为了探索传代胎儿肺 MSC（FLMSC）的治疗潜力，本研究评估了它们在体外扩增过程中的生长动力学、端粒长度、核型、免疫表型和分化潜能。FLMSCs 可以很容易地在体外扩增，端粒长度没有明显缩短，并且具有正常核型。使用流式细胞术进行的免疫表型分析中，在第 5 代或第 25 代之间没有观察到显著差异。此外，流式细胞术结果首次证明，据我们所知，FLMSCs 通过 25 代稳定表达多能标记物，包括 Oct4、Nanog、Sox2、TRA-1-60、c-Myc 和 SSEA-4。通过共聚焦显微镜、流式细胞术、RT-PCR 和免疫组织化学鉴定的体外分化研究表明，FLMSCs 具有向中胚层、外胚层和内胚层谱系分化的扩展能力，其成脂、成骨和成软骨分化的潜能可能在 25 代以上得到维持。此外，成骨和成软骨分化被用作其体内分化能力的指标，这一点可通过异位骨和软骨形成得到证明。总之，这些结果表明 FLMSCs 是原始群体，其广泛的体外扩增不涉及细胞的显著功能修饰，包括形态、生长、核型、免疫表型和中胚层分化潜能。因此，FLMSCs 可能构成用于细胞移植以诱导受损组织/器官再生的有吸引力的细胞资源。
