Induced neural stem cells have protective effects on cortical neuronal cells in vitro.

Reprogramming of fibroblasts into induced neural stem cells (NSCs) is a potentially unlimited source of neurons. In this study, we cocultured cortical neuronal cells with iNSCs in a transwell system. We then investigated the effects of coculture on apoptosis and the secretion of cytokines and growth factors. Compared with the cultured cortical neuronal culture alone, cortical neuronal cells cocultured with iNSCs exhibited increased proliferation. TUNEL assay was used to assess the rate of apoptosis at selected time intervals (24, 48 and 72 h). Cells cocultured with iNSCs had fewer apoptotic cells than those cultured without iNSCs. When TUNEL assay was performed in parallel with staining for the neuronal marker Tuj1, the number of neuronal apoptotic cells was found to be lower in cells cocultured with iNSCs than in those cultured without iNSCs for 72 h. Secretion of cytokines and growth factors by iNSCs was evaluated by ELISA. Compared to cells cultured without iNSCs, coculture decreased levels of the inflammatory cytokines and increased levels of HGF and VEGF. These findings indicated that iNSCs could be used as a new treatment strategy for neurodegenerative conditions by promoting proliferation and decreasing apoptosis of cortical neuronal cells.