Twente University, Institute for Biomedical Technology, Enschede, The Netherlands.
J Tissue Eng Regen Med. 2011 Mar;5(3):180-90. doi: 10.1002/term.303. Epub 2010 Aug 17.
For more than a decade, human mesenchymal stem cells (hMSCs) have been used in bone tissue-engineering research. More recently some of the focus in this field has shifted towards the use of embryonic stem cells. While it is well known that hMSCs are able to form bone when implanted subcutaneously in immune-deficient mice, the osteogenic potential of embryonic stem cells has been mainly assessed in vitro. Therefore, we performed a series of studies to compare the in vitro and in vivo osteogenic capacities of human and mouse embryonic stem cells to those of hMSCs. Embryonic and mesenchymal stem cells showed all characteristic signs of osteogenic differentiation in vitro when cultured in osteogenic medium, including the deposition of a mineralized matrix and expression of genes involved in osteogenic differentiation. As such, based on the in vitro results, osteogenic ES cells could not be discriminated from osteogenic hMSCs. Nevertheless, although osteogenic hMSCs formed bone upon implantation, osteogenic cells derived from both human and mouse embryonic stem cells did not form functional bone, indicated by absence of osteocytes, bone marrow and lamellar bone. Although embryonic stem cells show all signs of osteogenic differentiation in vitro, it appears that, in contrast to mesenchymal stem cells, they do not possess the ability to form bone in vivo when a similar culture method and osteogenic differentiation protocol was applied.
十多年来，人类间充质干细胞（hMSCs）一直被用于骨组织工程研究。最近，该领域的一些研究重点已经转向胚胎干细胞的使用。虽然众所周知，hMSCs 可以在免疫缺陷小鼠的皮下植入时形成骨，但胚胎干细胞的成骨潜能主要是在体外评估的。因此，我们进行了一系列研究，以比较人源和鼠源胚胎干细胞与 hMSCs 的体外和体内成骨能力。当在成骨培养基中培养时，胚胎干细胞和间充质干细胞在体外均表现出所有成骨分化的特征迹象，包括矿化基质的沉积和参与成骨分化的基因的表达。因此，基于体外结果，不能将成骨性 ES 细胞与成骨性 hMSCs 区分开来。然而，尽管成骨性 hMSCs 在植入后形成骨，但源自人和鼠胚胎干细胞的成骨细胞并未形成功能性骨，这表明缺乏骨细胞、骨髓和板层骨。尽管胚胎干细胞在体外表现出所有成骨分化的迹象，但似乎与间充质干细胞不同，当应用类似的培养方法和成骨分化方案时，它们在体内不具有形成骨的能力。
