Differentiation of human neural stem cells into retinal cells

We have previously reported that transplanted human neural stem cells (HNSCs) display extensive migration and positional incorporation into the aged rat brain, which is associated with an improvement in cognitive function. In the current study, to investigate whether HNSCs are capable of differentiating into retinal cells, we treated HNSCs with human transforming growth factor-beta3 (TGF-beta3) under a serum-free differentiation condition. After 5 days of differentiation in vitro we detected opsin-immunopositive cells in the culture treated with TGF-beta3. We also transplanted TGF-beta3-treated HNSCs into the rat vitreous cavity. The donor cells migrated and differentiated into opsin-positive cells in the host retinal cell layer. Here we show for the first time that TGF-beta3-treated HNSCs differentiate into retinal cells.