Neurogenin 2 enhances the neuronal differentiation of skin-derived precursors

Skin-derived precursors (SKPs), a novel stem cell population isolated from mammalian skin, can differentiate into neural and mesodermal lineages. Cell therapy using SKPs seems like a promising approach for the treatment of neural diseases, however, the low efficiency of neuronal differentiation limited their clinical application. In the present study, we transfected neurogenin 2 (Ngn2), a member of the bHLH transcription factor family, into SKPs by lentivirus. Morphological analysis, immunocytochemistry, Western blot, and electrophysiological analysis were performed to identify the cells derived from SKPs following 7-14 d neural induction. The results of immunocytochemistry staining showed that expression of neuronal markers, including MAP2, NF and NeuN were significantly elevated compared with those in GFP-SKPs and parental SKPs. Western blot confirmed the increased expression of NF-M and NeuN in Ngn2-SKPs-derived cells. Moreover, electrophysiological analysis showed that Ngn2-SKPs-derived neurons also acquired voltage-gated Na+ channels, which were absent in GFP-SKPs. Furthermore, western blot showed that Ngn2 enhanced the expression of Delta-like1, which reduced the level of Hes1 and suppressed Notch pathway. Therefore, overexpression of Ngn2 enhanced the neural differentiation of SKPs, probably through cis-inhibiting of Notch signal pathway.