: Investigating the Effect of microRNAs on Brain Progenitor Cells Population and Myelin Repair in an Experimental Model of Demyelination

Targeting endogenous stem cells via factors that affect their proliferation, migration and differentiation has been a priority in regenerative medicine. Beside various benefits, the most important bottleneck in this strategy is the limitation of endogenous stem cells resources. In recent years, the production of induced pluripotent stem cells (iPSCs) has led to more hopes to treat diseases. Application of Micro-RNAs and small molecules has been in the focus of attention over past few years to introduce safer methods in production of iPSCs. Recent reports showed the potential of miRs  in generation of iPSCs. Here we report the efficacy of microRNAS in converting neural cells into neural progenitors, in vivo. Viral particles was prepared for inducible expression of miRs cluster and injected i.c.v, and then induced for expression in presence of valproic acid for 7 days. Quantitative RT-PCR against neural progenitor markers and histochemical analysis were used to study the effect of miRs on the expression of neural progenitor markers. For assessing of myelin repair, we used Y-maze test and luxol fast blue staining.  qRT-PCR showed a significant increase in the expression level of Sox1, Oct4, c-Myc, Nestin but not in those of Sox2 and Nanog. Histochemical evaluation showed the expression of some neural progenitor markers in the rims of brain ventricle.Y- maze data revealed that this microRNAs could improve cuprizone induced demyelination. These findings suggest that microRNAs may increase progenitor cells by reprogramming of endogenous neural cells and provide new hope for increasing brain repair potential.