Vescovi A L, Galli R, Gritti A
Stem Cell Research Institute, DIBIT H. San Raffaele, Milan, Italy.
Biomed Pharmacother. 2001 May;55(4):201-5. doi: 10.1016/s0753-3322(01)00056-7.
Stem cells play a critical role during embryo and tissue formation throughout development. Thanks to their multipotentiality - i.e., the ability to give rise to different lineages of mature cells - and to their extensive capacity for self-renewal and expansive growth, stem cells can also contribute to the maintenance of tissue integrity in adulthood. Historically, it has been held that fetal and adult (somatic) stem cells are tissue-specific 'entities' whose differentiation potential is limited to the generation of mature cell types of the tissue/organ in which they reside. Yet, recent years have seen the publication of an impressive sequence of reports dealing with what is now emerging as one of the most striking functional attributes of somatic stem cells, that is, their capacity to undergo transdifferentiation. Thanks to this peculiar characteristic adult stem cells display an unexpected ability to give rise to differentiated cells of tissues and organs different from those in which they reside. This commentary briefly illustrates the characteristics of the neural stem cell and its capacity as a neuroectodermal derivative to undergo transdifferentiation, thus giving rise to differentiated cells that normally originate from the mesoderm, like blood or skeletal muscle cells.
在整个发育过程中,干细胞在胚胎和组织形成过程中发挥着关键作用。由于其多能性——即产生不同成熟细胞谱系的能力——以及自我更新和广泛增殖生长的能力,干细胞在成年期也有助于维持组织完整性。从历史上看,人们一直认为胎儿和成体(体细胞)干细胞是组织特异性的“实体”,其分化潜能仅限于产生它们所驻留的组织/器官的成熟细胞类型。然而,近年来,一系列令人印象深刻的报告相继发表,这些报告涉及体细胞干细胞目前正在显现的最显著功能特性之一,即它们的转分化能力。由于这一独特特性,成体干细胞展现出意想不到的能力,能够产生与其所驻留组织和器官不同的分化细胞。本评论简要阐述了神经干细胞的特征及其作为神经外胚层衍生物进行转分化的能力,从而产生通常源自中胚层的分化细胞,如血细胞或骨骼肌细胞。