Nisin and non-essential amino acids: new perspective in differentiation of neural progenitors from human-induced pluripotent stem cells in vitro

Over the past decades, stem cell therapy has been investigated as a promising approach towards various diseases, including neurodegenerative disorders. Stem cells show the capability to differentiate into neuronal progenitor cells in vitro. In the present study, the differentiation potential of human-induced pluripotent stem cells (hiPSCs) into neural lineages was examined under the efficient induction media containing forskolin and 3-isobutyl-1-methyl-xanthine (IBMX) in the presence of nisin (Ni), non-essential amino acids (NEAA) and combination of those (NEAA-Ni) in vitro. The optimum concentrations of these factors were obtained by MTT assay and acridine orange (AO) staining. The effect of Ni and NEAA on the expression rate of neural-specific markers including NSE, MAP2, and s-tubulin III was studied via immunocytochemistry (ICC) and real-time RT-PCR analyses. Our results indicated that the induction medium containing Ni or NEAA increased the gene and protein expression of NSE, MAP2, and β-tubulin III on the 14th differentiation day. On the other hand, NEAA-Ni showed a less-differentiated hiPSCs compared to Ni and NEAA alone. In conclusion, the obtained results illustrated that Ni and NEAA could be applied as effective factors for neural differentiation of hiPSCs in the future.