Stem Cells. 2009 Sep 1.

Developmental Regulation of Human Embryonic Stem Cell-Derived Neurons by Calcium Entry via Transient Receptor Potential (Trp) Channels.

Weick JP, Johnson MA, Zhang SC.

Waisman Center, University of Wisconsin, 651 Waisman Center, 1500 Highland Ave., Madison, WI 53705.

Spontaneous calcium (Ca(2+)) transients in the developing nervous system can affect proliferation, migration, neuronal subtype specification and neurite outgrowth. Here we show that telencephalic human neuroepithelia (hNE) and post-mitotic neurons (PMNs) generated from embryonic stem cells display robust Ca(2+) transients. Unlike previous reports in animal models, transients occurred by a Gd(3+)/La(3+)-sensitive, but thapsigargin- and Cd(2+)-insensitive mechanism, strongly suggestive of a role for transient receptor potential (Trp) channels. Furthermore, Ca(2+) transients in PMNs exhibited an additional sensitivity to the TrpC antagonist SKF96365 as well as shRNA-mediated knock down of the TrpC1 subunit. Functionally, inhibition of Ca(2+) transients in dividing hNE cells led to a significant reduction in proliferation, while either pharmacological inhibition or shRNA-mediated knockdown of the TrpC1 and TrpC4 subunits significantly reduced neurite extension in PMNs. Primary neurons cultured from fetal human cortex displayed nearly identical Ca(2+) transients and pharmacological sensitivities to Trp channel antagonists. Together these data suggest that Trp channels present a novel mechanism for controlling Ca(2+) transients in human neurons and may offer a target for regulating proliferation and neurite outgrowth when engineering cells for therapeutic transplantation.