In conclusion, we demonstrated that the epigenetic marks 3me-H3K27, 2me-H3K4, Ac-H4, and 5-MeC are prevalent throughout quiescent NSCs. Reduction of these epigenetic marks right before differentiation of the NSCs, indicates that these epigenetic marks are associated with the genes that maintain the quiescent state of the NSCs. A new wave of epigenetic marks appears as further differentiation proceeds in a subpopulation of NSCs. Meanwhile, characteristic translocation of the Ac-H4, 5-MeC, DNMT1, and DNMT3a occurred during differentiation, which may mediate the heterochromatin and euchromatin dynamics. AZA disrupted intracellular distribution patterns of the 2me-H3K4, DNMT1, and 5-MeC of the migrated NSCs, affecting chromatin remodeling at differentiation. These alterations are in parallel with the retarded migration and differentiation of the NSCs. The reported epigenetic dynamics in these distinct states of the NSC provide useful information for future investigation, including chromatin immunoprecipitation analysis of the specific genes, which associates with the epigenetic marks in mediating the awakening of neural stem cells from quiescent states.
