[Effect of accutase dissociation and passage on the apoptosis of human striatum derived neural stem cells].

Objective: To explore the status of apoptosis in human striatum derived neural stem cells (NSCs) aft er accutase dissociation and passage.
Methods: The NSCs were isolated from fetuses obtained through spontaneous abortion at 13- 18 weeks of pregnancy, which formed neurospheres in vitro. At passages of 3-5, the neurospheres were disassociated into single cell by accutase digestion and then passaged. At 1, 24 and 72 h after passage, the apoptosis of NSCs was measured by several methods, including active caspase-3 or TUNEL staining for fixed cells, Annexin V, Hoechst or PI staining for live cells.
Results: At all of the 3 time points, the staining of TUNEL and active caspase-3 overlapped perfectly. The apoptosis rate of NSCs increased significantly from 20%-25% at 1 h to 75%-80% at 24 h after passage (P<0.01). At 72 h, the apoptosis rate was significantly decreased as compared to that at 24 h time point because of the self-renewal and proliferation of survived NSCs (P<0.01).
Conclusion: Many cells in the neurospheres formed by human striatum-derived NSCs underwent apoptosis soon after accutase disassociation. For NSCs cultured in vitro, anti-apoptosis treatments might be a good method to increase the self-renewal and the proliferation of NSCs.