PA6-induced human embryonic stem cell-derived neurospheres: a new source of human peripheral sensory neurons and neural crest cells.

Human embryonic stem cells (hESC) have been directed to differentiate into CNS cells with clinical importance. However, for study of development and regeneration of the human PNS, and peripheral neuropathies, it would be useful to have a source of human PNS derivatives. We have demonstrated that peripheral sensory neuron-like cells (PSN) can also be derived from hESC via neural crest-like (NC) intermediates, and from neural progenitors induced from hESC using noggin. Here we report the generation of higher purity PSN from passagable neurospheres (NSP) induced by murine PA6 stromal cells. hESC were cultured with PA6, and colonies that developed a specific morphology were cut from the plates. Culture of these colonies under non-adhesive conditions yielded NSPs. Several NC marker genes were expressed in the NSP, and these were also detected in 3-5week gestation human embryos containing migrating NC. These NSPs passaged for 2-8weeks and re-plated on PA6 gave rise to many Brn3a+/peripherin+ cells, characteristic of early sensory-like neurons. Re-culturing PA6-induced NSP cells with PA6 resulted in about 25% of the human cells in the co-cultures differentiating to PSN after 1week, compared to only about 10% PSN obtained after 3 weeks when noggin-induced NSP were used. Two month adherent cultures of PA6-induced NSP cells contained neurons expressing several PSN neuropeptides, and voltage-dependent currents and action potentials were obtained from a molecularly identified PSN. hESC-derived PA6-induced NSP cells are therefore an excellent potential source of human PSN for study of differentiation and modeling of PNS disease.