1. Schematic diagram of the mechanisms underlying astrocyte-mediated brain ischemic tolerance.
Schematic diagram of the mechanisms underlying astrocyte-mediated brain ischemic tolerance. Severe ischemia induces neuronal death (without PC), whereas PC does not cause ischemic injury. Although neuron-derived HIF-1α is upregulated 1 d after PC, this event has no effect on brain injury by severe ischemia. In contrast, 3 d after PC, the upregulation of P2X7 receptors, followed by the upregulation of HIF-1α and neuroprotective molecules (EPO, etc.), is observed in activated astrocytes. Upregulation of P2X7 receptors provides neuroprotection against severe ischemia and induces ischemic tolerance.
Yuri Hirayama et al. J. Neurosci. 2015;35:
©2015 by Society for Neuroscience