星形胶质细胞AQP9在体外损伤反应中的表达变化

目的 通过体外培养星形胶质细胞,探讨星形胶质细胞水通道蛋白-9（aquaporin-9,AQP9）对损伤反应的表达变化及其所起的作用.方法 取出生后2 d的Wistar大鼠乳鼠大脑皮层进行星形胶质细胞纯培养,随机分为对照组和损伤组,每组分为1、3、5、7 d共4个时间点,采用划伤的方法建立星形胶质细胞对损伤反应的实验模型,通过形态学观察、免疫细胞化学染色、原位杂交图像分析等方法研究星形胶质细胞对损伤的反应及AQP9的表达变化.结果 星形胶质细胞受损后,形态学上表现为胞体肥大、突起增粗,呈反应性胶质化的典型特征;胶质纤维酸性蛋白（GFAP）免疫细胞化学染色增强;原位杂交分析表明,AQP9 mRNA表达在损伤后1 d显著增高,第3天至第5天达到高峰,与对照组相比,差异有统计学意义（P〈0.05）.结论 体外培养的星形胶质细胞对损伤表现为反应性胶质化、AQP9 mRNA表达增强,提示AQP9可能直接参与损伤性脑水肿的形成.

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.