The University of Georgia College of Veterinary Medicine

eorgia Veterinary Scholars Program

GVSP Summer 2008 Scholars

Georgia Veterinary Scholar	Faculty Mentor

Ai Tsuiki University of Tuskegee Class of 2010	Dr. Steve Stice

Glial Modulation of Differentiation of Human Embryonic Stem Cell Derived Neuroprogenitors

Tsuiki, Ai*. Dodla, Mahesh; Stice, Steven; School of Veterinary Medicine, Tuskegee University, Tuskegee, Alabama, Regenerative Bioscience Center, University of Georgia, Athens, Georgia

Human embryonic stem cell (hESCs)-derived neuroprogenitors (NPs) retain their multipotency (Nestin+ and Sox 2+) in vitro even after prolonged periods of culture. The NPs can be differentiated under various
conditions to give rise to all of the different neural cell types (neurons and glia). These neurons and glial cells can be identified using various markers, such as, beta-tubulin 3 (immature neurons), membrane associated protein (MAP2, mature neurons) and glial fibrillary protein (GFAP, astrocytes). These neurons and glial cells can then be used as models for studying the development of nervous system, pharmacological studies and cell replacement studies. However, the neurons derived from NPs do not form functional synapses spontaneously. In vivo and in vitro studies have shown that astrocytes play an important role in the regulation of neural stem cells. Astrocytes produce trophic factors that affect proliferation and differentiation of neural stem cells and potentiation of synapses. To examine the effects of astrocytes on differentiation of hESCsderived
NPs, we have differentiated them in glioblastoma-conditioned media and in direct co-culture with glioblastoma cells. NPs differentiated in regular differentiation media, without glioblastomas, were used as a control. The effect of astrocytic conditioned media and direct co-culture on neural differentiation was evaluated by immuno-staining for nestin, Sox 2, beta-tubulin 3, membrane associated protein 2 (MAP2), glialfibriallry protein (GFAP) and synaptophysin, after 3, 4 and 5 weeks of differentiation. The regulation of gene expression for various neural and astrocytic markers, and synaptic proteins will also be examined at 3, 4 and 5 weeks of differentiation.

Research Support: Department of Defence Grant
Student Support: T35 RR022685