Acute intermittent hypoxia alters cell fate choice in postnatal neural precursors

Abstract

In vitro exposure of neural progenitor cells (NPCs) to relative hypoxia (e.g. 3% versus 20% O2) can increase their proliferation, survival and neuronal differentiation both in culture and following transplantation. Recently, chronic intermittent hypoxia (CIH) was shown to increase proliferation in the dentate gyrus and subventricular zone (SVZ)—sites of postnatal neurogenesis. Our objective was to determine if in vivo exposure to acute intermittent hypoxia (AIH) could alter expansion and differentiation of subsequent in vitro cultures of SVZ NPCs. Neonatal C57BL/6 mice (postnatal day 4) were subjected to AIH (20×1 minute; alternating 21% and 10% O2), and sacrificed within 15 minutes of protocol termination. SVZ tissue was isolated and NPCs cultured as neurospheres (NS) or adherent monolayers (MASC). Expression of proliferation and neuronal fate markers was assessed with a range of methods including immunocytochemistry, western blot, fluorescence‐activated cell sorting and PCR. Our preliminary results indicate that in vivo exposure to AIH increases expression of proliferation and neuronal differentiation markers as subsequently assessed in in vitro NPC cultures. These data suggest that AIH protocols may provide a means to “prime” NPCs prior to harvest for subsequent transplantation into the injured central nervous system. This work is supported by 5K12HD055929 (HHR); 1R01HD052682‐01A1 (DDF)