Abstract：
Brain oedema is a common pathological phenomenon following many diseases and may lead to severe secondary damage. Astrocytes are the most numerous cells in the brain. Five aquaporins (AQPs) have been found in mature astrocytes, which play crucial roles in water transportation. However, most studies have focused on AQP4 or AQP9 and whether another aquaporin such as AQP5 involved in brain oedema is unclear. Here, we addressed the issue that the expression pattern of AQP5 in rat astrocytes in vitro was altered in the hypotonic condition through some mitogen-activated protein kinases (MAPK) pathways. Primary astrocytes were randomly divided into the control group and the hypotonic group. Cell viability was evaluated by MTT test. Immunofluorescence, Western blotting and real-time PCR were used to detect the expression of AQP5. Western blotting was used to detect the variation of MAPK pathway. The present study demonstrated that incubation of astrocytes in the hypotonic medium produced an increase inAQP5 expression, and AQP5 peaked at 6-12 h after hypotension solution exposure. In addition, MAPK pathways were set in motion under hypotension, but not all branches. Only the p38 inhibitor can inhibit AQP5 expression in cultured astrocytes. AQP5 is directly related to the extracellular hypotonic stimuli in astrocytes, which could be regulated through the p38 MAPK pathway.
摘要：
脑水肿是许多疾病后常见的病理现象，可能导致严重的继发性损害。星形胶质细胞是大脑中数量最多的细胞。在成熟的星形胶质细胞中发现了五种水通道蛋白（AQP），在水路运输中起着至关重要的作用。然而,大多数研究都集中在AQP4或AQP9,而另一种水通道蛋白如AQP5是否参与脑水肿尚不清楚.这里,我们解决了AQP5在体外大鼠星形胶质细胞中的表达模式在低渗状态下通过一些丝裂原活化蛋白激酶(MAPK)途径改变的问题.将原代星形胶质细胞随机分为对照组和低张组。通过MTT测试评价细胞活力。免疫荧光,采用Westernblotting和real-timePCR检测AQP5的表达。采用蛋白质印迹法检测MAPK通路的变异。本研究表明，在低渗培养基中孵育星形胶质细胞会增加AQP5的表达，AQP5在低血压溶液暴露后6-12h达到峰值。此外,MAPK通路在低血压下运动，但不是所有的分支。只有p38抑制剂可以抑制培养的星形胶质细胞中AQP5的表达。AQP5与星形胶质细胞的细胞外低渗刺激直接相关,可以通过p38MAPK通路进行调节。
