The changes of AQP9 expression during astrocytes reaction to injury in vitro

Objective To investigate the expressions of aquaporin-9(AQP9) and its role in cultured rat astrocytes after exposure to injury. Methods Rat cerebral cortical astrocytes from 2 days newborn Wistar rats were undergone the pure culture. The cells were divided into control group and injury group randomly, in which group was examined at interval times of 1, 3 , 5 and 7 d, respectively, and its model of injury was established by scratching the cultured astrocytes. The reactivity and rules of AQP9 mRNA expression of astrocyte to injury were studied by morphological changes, immunocytochemistry, in situ hybridization and imaging analysis. Results After scratching, the astrocytes showed topical features of reactive gliosis, with the hypertrophic cell body, thickened and lengthened processes, and enhanced glial fibrillary acidic protein(GFAP) staining was markedly increased. In situ hybridization analysis confirmed that the expression of AQP9 mRNA was remarkably increased. These changes occurred 1 d after scratching and reached the peak 5 to 7 d after injuring. These changes in the injury group were much more than those in the control group (P 0. 05). Conclusion A model of reactive astrogliosis was successfully established in vitro which showed an active reaction to injury, and induced expression of AQP9 mRNA increased. The results suggest that AQP9 participated in the brain edema of injury formation.