Department of Anesthesiology, Harvard Medical School, Brigham and Women's Hospital, Boston, MA 02115, USA.
Tissue Eng Part A. 2011 Mar;17(5-6):607-15. doi: 10.1089/ten.TEA.2010.0385. Epub 2011 Jan 10.
Mature adult tissues contain stem cells that express many genes normally associated with the early stage of embryonic development, when maintained in appropriate environments. Cells procured from adult tissues representative of the three germ layers (spinal cord, muscle, and lung), each exhibiting the potential to mature into cells representative of all three germ layers. Cells isolated from adult tissues of different germ layer origin were propagated as nonadherent clusters or spheres that were composed of heterogeneous populations of cells. When the clusters or spheres were dissociated, the cells had the ability to reform new, nonadherent spheres for several generations. When implanted in vivo, in association with biodegradable scaffolds, into immunodeficient mice, tissue containing cells characteristic of the three germ layers was generated. These findings suggest the existence of a population of stem cells in adult tissues that is quite different and distinct from embryonic stem cells that demonstrate a greater potency for differentiation across germ lines than previously believed. Such cells could potentially be as useful as embryonic stem cells in tissue engineering and regenerative medicine.
成熟的成人组织中含有干细胞，这些干细胞表达许多与胚胎发育早期相关的基因，这些基因在适当的环境中被维持。从代表三个胚层（脊髓、肌肉和肺）的成人组织中获得的细胞，每个细胞都有成熟为代表所有三个胚层的细胞的潜力。从不同胚层来源的成人组织中分离出的细胞作为非贴壁的细胞团或球体进行增殖，这些细胞团或球体由异质细胞群体组成。当细胞团或球体被解离时，细胞具有形成新的、非贴壁球体的能力，可以连续几代进行。当将这些细胞与可生物降解的支架一起植入免疫缺陷小鼠体内时，会产生含有具有三个胚层特征的细胞的组织。这些发现表明，成人组织中存在一种与胚胎干细胞截然不同的干细胞群体，其分化潜能比以前认为的跨越种系更为强大。与胚胎干细胞相比，这些细胞在组织工程和再生医学中可能具有同样的用途。
