Expression of steroid receptor coactivator-1 is elevated during neuronal differentiation of murine neural stem cells

The cell-lineage-specific fate of neural stem cells (NSCs) is defined by spatial and temporal gene expression regulated by various transcription factors and their coregulators, including coactivators and corepressors. To clarify the cellular distribution of the steroid receptor coactivator-1 (SRC-1), a ligand-dependent nuclear receptor coactivator, during neurogenesis, we examined the expression profiles of SRC-1 during the proliferation and differentiation in culture of NSCs derived from the ganglionic eminence of mouse embryos. We found that SRC-1 was rarely expressed in proliferating cells and multipotent precursors with the typical characters of NSCs. Under conditions that promote the differentiation of NSCs, both the SRC-1 transcript and protein levels were elevated and the population of SRC-1-positive cells was found to be higher in the mature neurons than in the immature neurons. In contrast, SRC-1 expression was rarely localized in the glial lineage cells, including astrocytes and oligodendrocytes. These results indicate that SRC-1 expression accompanies the appearance of neuronal-fate-committed cells derived from multipotent NSCs and is preferentially expressed in neuronal lineage cells during the differentiation of NSCs.