Microarray analysis of neural progenitor cells (hNPC) derived from the developing cortex (CTX) and ventral midbrain (VM)

Neural progenitor cells (hNPC) derived from the developing human brain can be expanded in culture and subsequently differentiated into neurons and glia. They provide an interesting source of tissue for both modeling brain development and future cellular replacement therapies. It is becoming clear that hNPC are regionally and temporally specified depending on which brain region they were isolated from and its developmental stage. We show here that hNPC derived from the developing cortex (hNPCCTX) and ventral midbrain (hNPCVM) have similar morphological characteristics and express the progenitor cell marker nestin. However, hNPCCTX cultures were highly proliferative and produced large numbers of neurons, while hNPCVM divided slowly and produced less neurons but more astrocytes. Microarray analysis revealed a similar expression pattern for some stemness markers between the two growing cultures, overlaid with a regionally specific profile that identified some important differentially expressed neurogenic transcription factors. By over expressing one of these, the transcription factor ASCL1, we were able to regain neurogenesis from hNPCVM cultures which produced larger neurons with more neurites than hNPCCTX, but no fully mature dopamine neurons. Thus hNPC are regionally specified and can be induced to undergo neurogenesis following genetic manipulation. While this restores neuronal production with a region specific phenotype, it does not restore full neurochemical maturation which may require additional factors.

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Kim HJ, McMillan E, Han F, Svendsen CN