Next, we evaluated ganglioside expression during neuronal differentiation of hDPSCs. The GD3 was expressed 1 week after neuronal differentiation, but that it was not expressed in undifferentiated hDPSCs. In addition, a significant increase in GD1a expression was detected upon application of hDPSCs to neuronal differentiation medium, and its expression level was maintained, even during later stages of neuronal differentiation. Moreover, GD3 and GD1a were co-expressed with MAP-2 and NeuN neuronal cell-specific genes. Previously, we demonstrated that the expression of GD3 increased along with early neuronal differentiation of ESCs, and that the expression of GD1a was only detected when ESCs further differentiated into neuronal
Vanoxerine dihydrochloride [16]. Therefore, our current findings suggest that the ganglioside expression patterns during neuronal differentiation of hDPSCs are similar to those of ESCs. However, the expression of GT1b and GQ1b was not observed when MAP-2 and NeuN were expressed, even at 2 weeks after neuronal differentiation. We previously demonstrated that GQ1b was co-expressed with MAP-2 in neuronal
cells differentiated from ESCs, which resulted in the formation of neuritis [16]. Although the expression of neuron-specific genes was detected, neurite-forming neuronal cells were not observed among the differentiated hDPSCs in the current study. It has been reported that undifferentiated/immature neurons express GD3, GD1a, and MAP-2 and that NeuN expression is not restricted to mature neurons [21], [22], [23] and [24]. Consequently, our findings suggest that hDPSC-derived neuronal cells that expressed MAP-2 and NeuN are immature neurons.
