20-06-08(14:52:53)
Authors:
Shin E, Palmer MJ, Fricker-Gates RA
Institutions:
Institute for Science and Technology in Medicine, Keele University, Staffordshire ST5 5BG, United Kingdom
Title of abstract : Generation of functional GABA neurons from mouse embryonic stem cells
Abstract text:
Huntington’s disease (HD) is caused by the mutant protein huntingtin, resulting in selective neuronal cell death in the striatum and cortex. Cell replacement using fetal tissues has been tried showing some success, but we need substitue cells becuase of technical and ethical issues of using fetal tissues. Because of their pluripotency and indefinite cell division, embryonic stem cells (ESCs) are very good candidate. We have been trying to differentiate mouse ESCs to functional striatal GABA neurons efficiently to transplant cells to a mouse HD model. Three different differentiation protocols - monolayer method, embryoid body method, and five stage method - have been used and all of them yielded similar percentage of GABA neurons from ESCs, based on immunocytochemical expression of appropriate markers. GABA neurons derived from ESCs using monolayer method were tested for their function compared to primary lateral ganglionic eminence (LGE) neurons, using patch clamp techniques. Primary and ESC-derived neurons had inward sodium and outward potassium currents, fired sodium channel-dependent action potentials (APs), and showed spontaneous AP firing and APs after hyperpolarization. Both LGE neurons and ESC-derived neurons had comparable resting membrane potentials, AP thresholds, AP amplitudes, and input resistances; but significantly different current thresholds for AP firing, AP durations, and membrane capacitances. Both types of neurons responded to L-glutamate, AMPA, and aspartate, proving the existence of functional glutamate receptors. Therefore ESC-derived cells not only look like neurons but also function similarly to striatal neurons derived from the LGE.
