P Khodabakhsh - Department of Pharmacology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
L Dargahi - Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
N Givzad - Department of Physiology, University of Saskatchewan, Sas-katchewan, Canada

Background: Epidermal neural crest stem cells (EPI-NCSCs) are multipotent stem cells able to undergo self-renewal and to generate all major neural crest derivatives, including neurons, Schwann cells, smooth muscle cells, bone/cartilage cells, and pigment cells. Previous studies reveal that insulin in neuro-sphere cultures promotes proliferation and differentiation of neural progenitors. These observations are highly relevant as the field of regenerative medicine moves closer to the devel-opment of tools to implement stem cell therapy for replacing damaged or lost neurons as a treatment for neurodegenerative diseases. Thus, the insulin signaling pathway may provide a ra-tional strategy to more efficiently proliferate in vitro and/or to improve the differentiation efficiency.Materials and Methods: Here, we studied the effects of met-formin (0.1, 1, 10, 100, 1000 and 10000 nM) on viability of EPI-NCSCs isolated from bulge of rat hair follicles through MTT assay.Results: The cells treated with most of the doses of metformin (0.1-100 nM) increased cell viability, dose dependently. It was also shown that cell viability was reduced in a decreasing man-ner in doses more than 1000 nM.Conclusion: Thus, metformin represents an optimal candidate neuro-regenerative agent that is capable of expanding the adult EPI-NCSC population. This study represents a vital step for-ward in the optimization of human EPI-NCSCs-based trans-plantation to promote neural damage recovery.

Insulin, Metformin, Epidermal Neural Crest Stem Cells, MTT, Rat