AQP4 and neuromyelitis optica: By using immunofluorescence staining, we discovered that CCL2 siRNA effectively prevented NMO-IgG-induced astrocyte damage, including preventing the accumulation of AQP4 in granules in the astrocyte cytosol and internalization to the cytoplasm as well as the reduction of AQP4 expressions (p < 0.001) (Figures 4C, D).