Department of Chemical and Biomolecular Engineering, Tulane University, Boggs Center, Room 300, New Orleans, Louisiana 70118, USA.
Biotechnol Bioeng. 2011 Nov;108(11):2716-26. doi: 10.1002/bit.23193. Epub 2011 May 10.
Human mesenchymal stem cells (MSCs) from bone marrow are a heterogeneous ensemble of progenitors and lineage-committed cells, with a broad range of regenerative properties. Ex vivo expansion to produce sufficient quantities of MSCs is essential for most therapeutic applications. The present study resolves the relationship between proliferation potential of MSCs and their potency. Clonal analysis generated single-cell derived colonies of MSCs that were classified according to their trilineage potential to exhibit adipo- (A), chondro- (C), and osteogenesis (O) as a measure of potency. Multipotent OAC clones were highly proliferative with colony-forming efficiencies that ranged from 35% to 90%; whereas, O clones formed colonies with an efficiency of 5% or less (P < 0.01). Similar trends were evident during ex vivo expansion: for example, the median specific growth rate was 0.8 day(-1) (20 h doubling time) for cultures inoculated with OAC clones and was 5-fold less for inocula of O clones (P < 0.01). OA and OC clones had similar proliferation potentials. More than 75% of cells in subconfluent cultures inoculated with O clones stained positive for senescence-associated β-galactosidase activity vs. less than 10% for OAC clones (P < 0.001). Apoptotic cells were in the minority for all potency groups. Preliminary data generated during clonal analysis suggest that osteogenic potential of MSCs to produce mineralized matrix is a function of potency, as well. These results are discussed in the context of the preparation of efficacious MSC therapies by ex vivo expansion.
骨髓间充质干细胞（MSCs）是一个异质性的祖细胞和谱系定向细胞的集合体，具有广泛的再生特性。体外扩增以产生足够数量的 MSCs 是大多数治疗应用的关键。本研究解决了 MSCs 增殖潜力与其潜能之间的关系。克隆分析产生了由单个细胞衍生的 MSC 克隆，这些克隆根据其三系潜能进行分类，以表现出脂肪生成（A）、软骨生成（C）和成骨作用（O），作为其潜能的衡量标准。多能 OAC 克隆具有高度增殖能力，集落形成效率范围为 35%至 90%；而 O 克隆的集落形成效率则低于 5%（P<0.01）。在体外扩增过程中也出现了类似的趋势：例如，接种 OAC 克隆的培养物的中位特定生长率为 0.8 天（20 小时倍增时间），而接种 O 克隆的培养物的生长率则低 5 倍（P<0.01）。OA 和 OC 克隆具有相似的增殖潜力。接种 O 克隆的亚汇合培养物中超过 75%的细胞染色呈衰老相关β-半乳糖苷酶活性阳性，而 OAC 克隆则不到 10%（P<0.001）。所有潜能组的凋亡细胞都较少。克隆分析过程中产生的初步数据表明，MSC 产生矿化基质的成骨潜力也是其潜能的一个功能。这些结果在通过体外扩增制备有效 MSC 治疗的背景下进行了讨论。
