Transient expression of Olig1 initiates the differentiation of neural stem cells into oligodendrocyte progenitor cells

In order to develop an efficient strategy to induce the in vitro differentiation of neural stem cells (NSCs) into oligodendrocyte progenitor cells (OPCs), NSCs were isolated from E14 mice and grown in medium containing epidermal growth factor and fibroblast growth factor (FGF). Besides supplementing the medium with oligodendrogenic factors such as Sonic Hedgehog (Shh), FGF2, and PDGF, we attempted to initiate the gene transcription program for OPC differentiation by transfection of the Olig1 gene, a transcription factor known to be involved in the induction of oligodendrocyte lineage formation during embryogenesis. Whereas addition of Shh, FGF-2, and PDGF could induce OPC differentiation in 12% of the NSCs, the transient expression of Olig1 by use of Nucleofector gene transfection initiated OPC differentiation in 55% of the NSCs. Our results show that nonviral transfection of genes encoding for oligodendrogenic transcription factors may be an efficient way to initiate the in vitro differentiation of NSCs into OPCs

Functionally deficient neuronal differentiation of mouse embryonic neural stem cells in vitro

Embryonic mouse neural stem cells (NSCs) were isolated from E14 mice, multiplied in medium containing epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) and plated in laminin-coated wells in basic serum-free neurobasal medium. After 7 days in vitro, approximately 20% of the embryonic mouse NSCs developed into morphologically and biochemically fully maturated neurons, with extensive dendrites and multiple synaptic contacts. However, even after 22 days of culture, none of these neurons developed voltage-dependent sodium-channels characteristic for a functional neuron. Apparently, the morphological differentiation and the electrophysiological maturation of an embryonic mouse NSC into a neuron are independently regulated. (C) 2004 Elsevier Ireland Ltd and The Japan Neuroscience Society. All rights reserved.</p