Ion Channels and Ionotrophic Receptors in a Human Embryonic Stem Cell Derived Neural Progenitors

• Published in: Neuroscience Vol. 192; pp. 793 - 805
• Main Authors: Young, Amber, Machacek, Dave W., Dhara, Sujoy K., MacLeish, Peter R., Benveniste, Morris, Dodla, Mahesh C., Sturkie, Carla D., Stice, Steven L.
• Format: Journal Article
• Language: English
• Published: 07.06.2011
• ISSN: 0306-4522; 1873-7544
• DOI: 10.1016/j.neuroscience.2011.04.039

Human neural progenitor cells differentiated from human embryonic stem cells offer a potential cell source for studying neurodegenerative diseases and for drug screening assays. Previously, we demonstrated that human neural progenitors could be maintained in a proliferative state with the addition of leukemia inhibitory factor and basic fibroblast growth factor. Here we demonstrate that 96 hours after removal of basic fibroblast growth factor the neural progenitor cell culture was significantly altered and cell replication halted. 14 days after the removal of basic fibroblast growth factor, most cells expressed MAP2 and TUJ1, markers characterizing a post-mitotic neuronal phenotype as well as neural developmental markers Cdh2 and Gbx2 . Real-time PCR was performed to determine the ionotrophic receptor subunit expression profile. Differentiated neural progenitors express subunits of glutamatergic, GABAergic, nicotinic, purinergic and transient receptor potential receptors. In addition, sodium and calcium channel subunits were also expressed. Functionally, virtually all the NP cells tested under whole-cell voltage clamp exhibited delayed rectifier potassium channel currents and some differentiated cells exhibited tetrodotoxin-sensitive, voltage-dependent sodium channel current. Action potentials could also be elicited by current injection under whole-cell current clamp in a minority of cells. These results indicate that removing basic fibroblast growth factor from the neural progenitor cell cultures leads to a post-mitotic state, and has the capability to produce excitable cells that can generate action potentials, a landmark characteristic of a neuronal phenotype. This is the first report of an efficient and simple means of generating human neuronal cells for ionotrophic receptor assays and ultimately for electrically active human neural cell assays for drug discovery.