Changes in AQP4 expression and the pathology of injured cultured astrocytes after AQP4 mRNA silencingAuthor(s): Jianqiang Chen, Qingjie Xia, Hong Lu
In this study, we investigated AQP4 expression in injured astrocytes in vitro, as well as the influence of AQP4 levels on pathology using gene silencing.
Astrocytes were cultured and the mechanical scratch method was used to simulate an injury. Cells were randomly divided into the control group, injury group, Scramble group (P-AQP4), and RNA interference group (siRNA-AQP4), and each group was divided into subgroups that were evaluated after 1, 3, 6, 12, 24, 48, and 72 h. Cell morphology and pathological changes were observed, and AQP4 protein abundance was measured.
The morphology of the interference group was unchanged at 12 h, but cellular edema was significantly reduced at 24-72 h in comparison with the injury and Scramble groups. In interference group, AQP4 abundance was reduced after 1 h and reached its minimum level after 12 h, then increased to a peak level at 48 h, after which it declined from 48-72 h. With the exception of the 1 h time point, AQP4 protein levels in the interference group and the control group were significantly different throughout the observation period. In the interference group, AQP4 protein abundance decreased during the first 12 h of observation, increased from 24-48 h, then decreased at 72 h.
These results suggest that up-regulation of AQP4 in injured astrocytes mediates the delayed occurrence of edema in vitro, and AQP4 gene silencing effectively prevents edema in the mechanical scratch injury model. AQP4 down-regulation in astrocytes in the early stages of injury is likely a self-protective response.