Aged human mesenchymal stem cells: the duration of bone morphogenetic protein-2 stimulation determines induction or inhibition of osteogenic differentiation
Aged human mesenchymal stem cells: the duration of bone morphogenetic protein-2 stimulation determines induction or inhibition of osteogenic differentiation
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DOI：
10.4081/or.2014.5242
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发表时间：
2014-01-01
影响因子：
2.1
通讯作者：
Prall, Wolf Christian
中科院分区：
文献类型：
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作者：
Heggeboe, Jostein;Haasters, Florian;Prall, Wolf Christian
骨形态发生蛋白2（BMP-2）是一种强有力的骨诱导细胞因子，越来越多的体外研究分析了其对来自老年或骨质疏松供体的人间充质干细胞（hMSC）的作用。在这些研究中，成骨分化能力的精确定量是基本的兴趣。然而，老年hMSC的成骨分化的实验条件尚未得到系统的评价，并在相当大的程度上变化。本研究的目的是评估细胞密度、成骨分化培养基（ODM）变化间隔和BMP 2刺激持续时间对骨诱导的影响。此外，对ODM/BMP-2细胞培养上清液中的成骨分化和BMP-2浓度进行时间序列。使用从接受髋关节置换的老年患者的股骨头分离的hMSC进行实验。与较短的间隔相比，96小时的ODM更换间隔导致显著更高的钙沉积。与较高的细胞密度相比，刺激前80%的细胞密度导致更强的骨诱导。在ODM中，老化的hMSC在9天后显示出显著的钙沉积诱导。加入ODM中，BMP-2在细胞培养上清液中显示稳定浓度至少96小时。与单独的ODM相比，在最初的4天向ODM中添加BMP-2导致显著更高的成骨分化诱导。另一方面，添加BMP-2 21天几乎消除了ODM的骨诱导作用。我们可以证明，调查的因素对老年人hMSC的成骨分化的程度有实质性的影响。因此，最重要的是使实验条件标准化，以使不同研究之间具有可比性。我们在这里定义的标准条件，成骨分化方面的具体特点，老年人骨髓基质细胞。BMP-2以时间依赖性方式诱导或抑制成骨分化的发现表明hMSC信号转导的年龄相关改变，需要进一步研究。
Bone morphogenetic protein 2 (BMP-2) is a potent osteoinductive cytokine and a growing number of in vitro studies analyze its effects on human mesenchymal stem cells (hMSC) derived from aged or osteoporotic donors. In these studies the exact quantification of osteogenic differentiation capacity is of fundamental interest. Nevertheless, the experimental conditions for osteogenic differentiation of aged hMSC have not been evaluated systematically and vary to a considerable extend. Aim of the study was to assess the influence of cell density, osteogenic differentiation media (ODM) change intervals and duration of BMP2 stimulation on osteoinduction. Furthermore, time series were carried out for osteogenic differentiation and BMP-2 concentration in ODM/BMP-2 cell culture supernatants. The experiments were performed using hMSC isolated from femoral heads of aged patients undergoing hip joint replacement. ODM change intervals of 96 hours resulted in significantly higher calcium deposition compared to shorter intervals. A cell density of 80% prior to stimulation led to stronger osteoinduction compared to higher cell densities. In ODM, aged hMSC showed a significant induction of calcium deposition after 9 days. Added to ODM, BMP-2 showed a stable concentration in the cell culture supernatants for at least 96 hours. Addition of BMP-2 to ODM for the initial 4 days led to a significantly higher induction of osteogenic differentiation compared to ODM alone. On the other hand, addition of BMP-2 for 21 days almost abrogated the osteoinductive effect of ODM. We could demonstrate that the factors investigated have a substantial impact on the extent of osteogenic differentiation of aged hMSC. Consequently, it is of upmost importance to standardize the experimental conditions in order to enable comparability between different studies. We here define standard conditions for osteogenic differentiation in regard to the specific features of aged hMSC. The finding that BMP-2 induces or inhibits osteogenic differentiation in a time dependent manner indicates an age related alteration in signal transduction of hMSC and requires further investigation.