Comparative analysis of neuroectodermal differentiation capacity of human bone marrow stromal cells by various conversion protocols

Marrow stromal cells (MSCs) are capable of differentiating into multiple mesodermal tissues, including bone, cartilage, fat, and muscle. In addition, these cells were reported to differentiate in vitro and in vivo into cells expressing neuronal and glial markers. However, some controversy persists regarding the in vitro differentiation potential of MSCs into neurons and glia. Several in vitro studies, could not reproduce some of the transdifferentiation protocols. To clarify the neuroectodermal potential of human MSCs, we reevaluated some recent protocols used for the neuroectodermal differentiation of human MSCs in the present study. hMSCs expressed high levels of FN, FDZ1, PTCH as well as the multipotency marker OCT-4. Importantly, we found that many neuroectodermal genes, such as NES, ß-tubulin III, GFAP are already expressed by hMSCs. Interestingly, when comparing six common protocols for conversion of hMSCs towards neurons and glia only our multistep conversion and differentiation protocol was able to further induce a functional neuroectodermal phenotype with subsequent loss of their mesenchymal potential. All other protocols failed to further induce a functional neuroectodermal phenotype. At present we perform multiple co-culture analyses to further define the differentiation potential of hMSCs. Therefore we provide impetus that hMSCs can be efficiently differentiated into functional neuroectodermal cells by a multistep protocol. Our cell culture system provides a powerful tool for investigating the molecular mechanisms of neural differentiation in adult human NSCs. hmNSCs may therefore ultimately help to treat acute and chronic neurodegenerative diseases.