Neural stem cells derived from epiblast stem cells display distinctive properties

Abstract

Pluripotent stem cells can be derived from preimplantation and postimplantation mouse embryos. Embryonic stem cells (ESCs) derived from blastocysts are in a “naive” pluripotent state and meet all of the criteria for pluripotency, including the ability to generate live pups through tetraploid complementation. Epiblast stem cells (EpiSCs) derived from postimplantation epiblasts are in a “primed” pluripotent state. ESCs and EpiSCs show different phenotypes and gene expression patterns, and EpiSCs are thought to be less pluripotent than ESCs. In this study, we addressed whether EpiSCs can be differentiated into specialized cell types in vitro. To do this, we first derived EpiSCs from E5.5–6.5 mouse embryos containing the Oct4-GFP transgene. We found that EpiSCs expressed pluripotency markers and differentiated into all three germ layers in intro and in vivo. Interestingly, EpiSCs also efficiently differentiated into a homogenous population of neural stem cells (NSCs) in vitro. The EpiSC-derived NSCs (EpiSC-NSCs) expressed NSC markers (Nestin, Sox2, and Musashi), self-renewed for more than 20 passages, and differentiated into neuronal and glial neural cell subtypes in vitro. We then transplanted the EpiSC-NSCs into the neonatal mouse brains, and found that they were able to survive and differentiate into robust neurons and glial cells in the mouse brains, demonstrating that primed pluripotent EpiSCs efficiently form functional NSCs. We compared the global gene expression patterns of NSCs differentiated from EpiSC-NSCs, ESCs, and brain tissue and found that the expression patterns of most genes, including pluripotency and NSC specificity, were similarly clustered, but that the developmental process-related genes were distantly clustered. Moreover, the global gene expression pattern of brain-derived NSCs was more similar to that of ESC-derived NSCs than that of EpiSC-derived NSCs. Taken together, these results indicate that although NSCs, regardless of their origins, display very similar in vitro and in vivo differentiation properties, their global gene expression profiles may differ, depending on the pluripotency state, i.e., naive or primed.