P2X7 Receptor Regulation of Hippocampal Neural Progenitor Cells

Hannah Caitlin Leeson, University, My, Jeremy Brownlie, Michael Weible
Adult hippocampal neurogenesis plays an essential role in the formation and consolidation of new memories, spatial processing and some forms of learning. Identifying the molecular mechanisms that regulate hippocampal neural progenitor cells as they proliferate, differentiate, and are selected for either survival or cell death will provide a fundamental understanding of how this neurogenic niche coordinates these activities. Here, the roles of P2X7 receptors are examined for their influence over
more » ... neural progenitor cell biology, particularly cell death, proliferation, and phagocytosis of apoptotic progenitors that have undergone programmed cell death. As a purinergic cation channel, P2X7 receptors are exceptionally versatile; their primary role is as ATP-gated calcium channels, and they have notable roles in the immune system, where they regulate cytokine release and form large transmembrane pores resulting in cell death. By acting as scavenger receptors, they can also mediate phagocytosis. These diverse roles were investigated in neural progenitor cells of the adult murine hippocampal neurogenic niche. Primary cultures of hippocampal neural progenitor cells were derived from adult female C57BL/6 mice and characterised using multimarker immunocytochemistry as P2X7 receptor positive type 2 neural progenitor cells, as defined by Sox2pos, nestinpos, BLBPpos, Mash1pos/neg, vimentinpos, Pax6pos, Prox1pos, DCXneg, GFAPneg staining patterns. For some experiments, cultures derived from P2X7 knock out mice (Pfizer) were also used. Calcium influx assays using the indicator dye Fluo-8-AM demonstrated functional activity of P2X7 receptors with the general agonist ATP (1 mM) and the more specific agonist BzATP (100 μM). Ethidium bromide uptake demonstrated that P2X7 receptors were able to form large transmembrane pores, a canonical function unique to this receptor, and confirmed the presence of a full length protein, as opposed to various splice variants. Live cell confocal microscopy revealed hippocampal neural progenitors are [...]
doi:10.25904/1912/2024 fatcat:nbseqqvsujbltaj6z6oegeu7ni