Aquaporin‐4 and transient receptor potential vanilloid 4 balance in early postnatal neurodevelopment

In the adult brain, the water channel aquaporin‐4 (AQP4) is expressed in astrocyte endfoot, in supramolecular assemblies, called “Orthogonal Arrays of Particles” (OAPs) together with the transient receptor potential vanilloid 4 (TRPV4), finely regulating the cell volume. The present study aimed at investigating the contribution of AQP4 and TRPV4 to CNS early postnatal development using WT and AQP4 KO brain and retina and neuronal stem cells (NSCs), as an in vitro model of astrocyte differentiation. Western blot analysis showed that, differently from AQP4 and the glial cell markers, TRPV4 was downregulated during CNS development and NSC differentiation. Blue native/SDS‐PAGE revealed that AQP4 progressively organized into OAPs throughout the entire differentiation process. Fluorescence quenching assay indicated that the speed of cell volume changes was time‐related to NSC differentiation and …