During the reprogramming of mouse embryonic fibroblasts (MEFs) to induced pluripotent stem cells, the activation of pluripotency genes such as Nanog occurs after the mesenchymal to epithelial transition (MET). Here we report that both adult stem cells (neural stem cells- NSCs) and differentiated cells (astrocytes) of the neural lineage can activate Nanog in the absence of cadherin expression during reprogramming. Gene expression analysis revealed that only the Nanog+Ecadherin+ populations expressed stabilization markers and had upregulated several cell cycle genes; and were transgene independent. Inhibition of Dot1L activity, which has previously been shown to increase MET, enhanced both the numbers of Nanog+ and Nanog+E-cadherin+ colonies, suggesting a MET independent pathway for activation of Nanog in NSCs.  Expressing Sox2 in MEFs prior to reprogramming does not alter the ratio of Nanog colonies that express E-cadherin obtained. Taken together these results provide a novel pathway for reprogramming taken by cells of the neural lineage. SOURCE: Rupa Sridharan University of Wisconsin

Pluto Bioinformatics

GSE76130: Alternative routes to induced pluripotent stem cells revealed by reprogramming of neural lineage