Department of Chemical Engineering, Queen's University, Kingston, Ont., Canada.
Cells Tissues Organs. 2012;195(5):414-27. doi: 10.1159/000329254. Epub 2011 Sep 5.
Adipose-derived stem cells (ASCs) represent an excellent cell source for the development of regenerative therapies for a broad variety of tissue disorders. Commonly, in vitro expansion is necessary to obtain sufficient cell populations for research purposes and clinical applications. Although it has been demonstrated that human ASCs can maintain their adipogenic, chondrogenic and osteogenic potential in long-term culture (up to 15 passages), it is not guaranteed that a satisfactory level of differentiation is achievable in later passages. In this study, we investigated the self-renewal and multilineage differentiation capacity of bovine ASCs, isolated from the interdigital fat pad, and explored how serial passaging influences the cells. A proliferation study examined the changes in growth kinetics from passage 1 to 5, and multilineage (adipogenesis, chondrogenesis and osteogenesis) differentiation studies were conducted to compare the potential between passage 2 (P2) and passage 5 (P5). From the proliferation study, a statistically significant change in the doubling time did not appear until P5. In the differentiation study, both P2 and P5 ASCs could be stimulated to undergo multilineage differentiation under specific culturing conditions. However, adipogenic and chondrogenic cultures showed significantly lower levels of differentiation in the P5-induced cultures. In contrast, P5-induced osteogenic cultures had higher alkaline phosphatase enzyme activity than P2-induced cultures, suggesting an increase in the osteogenic response with serial passaging. Overall, bovine ASCs are capable of self-renewal and multilineage differentiation; however, long-term in vitro expansion has a negative effect on adipogenic and chondrogenic differentiation, while potentially favoring osteogenesis.
脂肪来源干细胞（ASCs）是一种非常优秀的细胞来源，可用于开发多种组织疾病的再生疗法。通常，为了获得用于研究和临床应用的足够细胞群体，需要进行体外扩增。尽管已经证明人类 ASC 可以在长期培养（长达 15 代）中保持其成脂、成软骨和成骨的潜力，但并不能保证在后期传代中能够达到令人满意的分化水平。在这项研究中，我们研究了从指间脂肪垫分离的牛 ASC 的自我更新和多能性分化能力，并探讨了连续传代如何影响细胞。增殖研究检查了从第 1 代到第 5 代的生长动力学变化，多能性（成脂、成软骨和成骨）分化研究用于比较第 2 代（P2）和第 5 代（P5）之间的潜力。从增殖研究来看，直到 P5 才出现倍增时间的统计学显著变化。在分化研究中，在特定培养条件下，均可以刺激 P2 和 P5 ASC 进行多能性分化。然而，在 P5 诱导的培养物中，成脂和成软骨培养物的分化水平明显较低。相比之下，P5 诱导的成骨培养物的碱性磷酸酶酶活性高于 P2 诱导的培养物，表明随着连续传代，成骨反应增加。总体而言，牛 ASC 具有自我更新和多能性分化的能力；然而，长期的体外扩增对成脂和成软骨分化有负面影响，而可能有利于成骨分化。
