Human embryonic stem cells (hESC) and induced pluripotent stem cells
(hiPSC) possess the capability of differentiating into all derivatives
of the three germ layers including neural cells. Human pluripotent stem
cell (hPSC) derived neural cells have been used for studying nervous
system development, modeling neurologic disorders, neurotoxicology and
drug screening. SMAD signaling plays a crucial role in neural induction.
Dual inhibition of SMAD signaling by Noggin and SB431542 is sufficient
to induce rapid and complete neural conversion of hPSCs [1]. In 2010,
Wenlin Li and colleagues found that synergistic inhibition of glycogen
synthase kinase 3 (GSK3) and transforming growth factor β (TGF-β) could
efficiently differentiate hPSCs to homogenous neural epithelium in 7
days [2]. The derived neural stem cells (NSCs) can self-renew in the
presence of human leukemia inhibitory factor (LIF) and inhibitors of
GSK3 and TGF-β. NSCs possess the multipotential of differentiating into
various neuronal and glial subtypes upon induction with specific
patterning cues [2].
Based on the advances in neural differentiation methodologies, we
developed hPSC Neural Induction Medium (PSCNIM, Cat. #5931), a
serum-free medium, to efficiently convert hPSCs to NSCs under adherent
culture conditions. The hPSCs are converted to homogenous neural
epithelium using neural induction medium (Figure 1). After a 7 – 10 day
treatment with PSCNIM, more than 90% of cells expressed the neural stem
cell markers: Nestin and Sox2; while the pluripotency marker Nanog
expression was lost (Figure 2). NSCs derived from hPSC can be maintained
in the induction medium for at least 5 passages (~24 days), can
efficiently form rosettes (Figure 3) and be expanded as neural
progenitor cells in EGF and FGF containing medium, or differentiated
into neural lineages such as neurons and astrocytes (Figure 3).
