低渗液对星形胶质细胞水通道蛋白-9表达的影响

目的探讨体外培养星形胶质细胞在低渗状态下水通道蛋白-9(aquaporin-9,AQP9)表达的变化特点及其所起的作用。方法取生后2d的Wistar大鼠大脑皮层进行星形胶质细胞纯培养,随机分为对照组和低渗组(又分268、254、240mmol/L三个组),每组分为3、6、12、24h共4个时间点,每个时间点细胞孔数为6。对照组予正常培养液常规培养,低渗组分别予不同渗透压的低渗液作用于细胞,建立星形胶质细胞对低渗液反应的实验模型。通过采用原位杂交检测AQP9mRNA的表达,乳酸脱氢酶活性的测定及图像分析等方法研究星形胶质细胞对低渗液的反应及AQP9的表达变化。结果对照组在正常渗透压培养液中培养3、6、12、24h后,AQP9表达差异无统计学意义(P>0.05)。在相同的作用时间条件下,各低渗组细胞AQP9mRNA表达水平均明显高于对照组(P<0.05)。尤以作用12h后明显,而且与作用时间和低渗液的程度密切相关;同时细胞存活能力明显下降,其严重程度与低渗液的作用时间和渗透压有关。结论低渗液可导致细胞的生存能力下降、AQP9mRNA表达增强,提示星形胶质细胞AQP9的表达与渗透压可能直接相关,AQP9可能参与脑水肿的形成。

Effect of hypotonic medium on expression of aquaporin - 9 in astrocytes

Objective To investigate the expressions of aquaporin-9(AQP9) and its role in cultured rat astrocytes after exposure to hypotonic medium.Methods Rat cerebral cortical astrocytes from 2 days newborn Wistar rats were undergone the pure culture.The cells were divided into control group and hypotonic groups randomly,in which group was examined at interval times of:3,6,12 and 24 h,respectively(n=6),and its model of cell edema was established by exposed to hypotonic medium.The cells of the control group were cultured in normal culture medium.The reactivity and rules of AQP9 mRNA expression of astrocyte to hypotonic medium were studied by in situ hybridizution,the activity of LDH and imaging analysis.Results There was no significant change in the control group.After astrocytes cultured for 3,6,12,24 h with hypotonic medium(268,254,240 mmol/L),The activity of LDH showed a significant change than those in the control group after astrocytes exposed to hypotonic medium(P<0.05).Analysis confirmed that the expression of AQP9 mRNA was remarkably increased(P<0.05),especially expression of AQP9 was significantly increased with hypotonic medium for 12 hours.Up-graduated expression of AQP9 was correlated with hypotonic medium and time dependent manner.Conclusion Hypotonic medium could induce expression of AQP9 mRNA increased,and vibility of astrocytes inhibited.The AQP9 expression showed a positive relationship with the osmolality.The results suggest that AQP9 participated in the brain edema formation.