Department of Biomedical Sciences, University of Ulsan College of Medicine, Seoul, Korea ; Department of Physiology, University of Ulsan College of Medicine, Seoul, Korea.
Stem Cell Institute at the James Graham Brown Cancer Center, University of Louisville, KY, USA.
Int J Stem Cells. 2014 Nov;7(2):55-62. doi: 10.15283/ijsc.2014.7.2.55.
Pluripotent stem cells (PSCs) have been considered as the most important cells in regenerative medicine as they are able to differentiate into all types of cells in the human body. PSCs have been established from several sources of embryo tissue or by reprogramming of terminally differentiated adult tissue by transduction of so-called Yamanaka factors (Oct4, Sox2, Klf4, and cMyc). Interestingly, accumulating evidence has demonstrated the residence of PSCs in adult tissue and with the ability to differentiate into multiple types of tissue-committed stem cells (TCSCs). We also recently demonstrated that a population of pluripotent Oct4(+) SSEA-1(+)Sca-1(+)Lin(-)CD45(-) very small embryonic-like stem cells (VSELs) resides in the adult murine bone marrow (BM) and in other murine tissue. These very small (∼3-6 μm) cells express pluripotent markers such as Oct4, Nanog, and SSEA-1. VSELs could be specified into several tissue-residing TCSCs in response to tissue/organ injury, and thus suggesting that these cells have a physiological role in the rejuvenation of a pool of TCSCs under steady-state conditions. In this review article, we discuss the molecular nature of the rare population of VSELs which have a crucial role in regulating the pluripotency, proliferation, differentiation, and aging of these cells.
多能干细胞（PSCs）被认为是再生医学中最重要的细胞，因为它们能够分化为人体中的所有类型的细胞。PSCs 已经从几种胚胎组织来源或通过转导所谓的 Yamanaka 因子（Oct4、Sox2、Klf4 和 cMyc）对终末分化的成体组织进行重编程而建立。有趣的是，越来越多的证据表明 PSCs 存在于成体组织中，并且具有分化为多种组织定向干细胞（TCSCs）的能力。我们最近还证明，在成年鼠骨髓（BM）和其他鼠组织中存在一群多能 Oct4(+)SSEA-1(+)Sca-1(+)Lin(-)CD45(-)非常小的胚胎样干细胞（VSELs）。这些非常小的（∼3-6μm）细胞表达多能标记物，如 Oct4、Nanog 和 SSEA-1。VSELs 可以在组织/器官损伤时被指定为几种组织驻留的 TCSCs，这表明这些细胞在稳态条件下 TCSCs 池的更新中具有生理作用。在这篇综述文章中，我们讨论了稀有 VSELs 群体的分子性质，它们在调节这些细胞的多能性、增殖、分化和衰老方面起着关键作用。
