Figure 8.

Mechanisms of AQP4-A25Q mutation-dependent neuroprotection in cerebral edema. In the normal brain, astrocytes occupy a strategic position between capillaries and neurons. Perivascular astrocytic endfeet at BBB maintain brain ion and water homeostasis. In the swollen brain, AQP4 facilitates water movement across the BBB into astrocytes, resulting in astrocyte swelling and astrocyte activation. The aquaporin 4-A25Q mutation causes OAP depolymerization and inhibits supramolecular clustering, resulting in less AQP4 anchored at glial endfeet, consequently decreasing water movement from the vasculature into astrocytes and alleviating neuronal injury.