低渗状态下星形胶质细胞AQP4mRNA的表达和Ca^(2+)浓度的关系  

Study on the relationship between AQP4mRNA expression and Ca^(2+)of astrocytes during hypotonic medium

作　　者：李燕华[1] 孙善全[2] 李吕力[1] 王铁建[1] 

机构地区：[1]广西壮族自治区人民医院神经内科,广西南宁530021 [2]重庆医科大学神经生物学研究室,重庆400016

出　　处：《中风与神经疾病杂志》2005年第4期292-295,i0001,共5页Journal of Apoplexy and Nervous Diseases

基　　金：国家自然科学基金资助课题(30070247)

摘　　要：目的探讨低渗培养液对星形胶质细胞AQP4mRNA的表达变化和Ca2+浓度的影响及其之间的关系。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,分别予不同程度的低渗培养液作用于细胞,建立细胞对低渗液反应的实验模型。应用台盼蓝测定细胞存活率,采用原位杂交检测AQP4mRNA的表达,Fura-2/AM荧光法测定细胞内Ca2+浓度。结果体外培养的星形胶质细胞在低渗培养液分别作用3h、6h、12h、24h后,低渗组的细胞存活率较对照组明显减少,各时间点AQP4mRNA表达水平与细胞内Ca2+含量均明显高于对照组,与对照组相比差异有显著意义(P<0.05),而且与作用时间以及低渗液的严重程度密切相关;AQP4mRNA的表达强度与Ca2+浓度的变化呈明显正相关。结论低渗液可引起星形胶质细胞AQP4mRNA的表达上调,导致细胞内Ca2+超载,AQP4和Ca2+可能共同参与脑水肿的形成,提示AQP4可能是脑水肿的重要致病因素之一。Objective To investigate the expression of aquaporin-4mRNA and influence of Ca^2＋concentration in cultured rat astrocytes after exposure to hypotonic medium and its relationship, Methods Rat cerebral cortical astrocytes from 2 days newborn Wistar rat were undergone the pure culture and its model of cell edema was established by exposeure to hypotonic medium. Cell viability and AQP4mRNA expression of astrocyte to hypotonic medium were assessed by the number of dead cells and in situ hybridizution. Fura-2/AM fluoremetry technique was used to determine the cellular free calcium concentration of astrocytes. Results Astrocytes exposed to hypotonic medium showed a significantly change in cell viability. The expression of AQP4mRNA and Ca^2＋ concentration of astrocytes cultured for 3,6.12,24 hours with hypotonic medium（268,254 and 240mmol/L） were remarkably increased than those in control group（P〈0. 05）,hypotonic medium inhibit the proliferation of astrocytes and induce expression of AQP4mRNA in hypotonic-osmolality and time-dependent manner. The AQP4mRNA expression showed a positive relationship with the Ca^2＋concentration. Conclusion Hypotonic medium can induce the expression of AQP4mRNA. The up-graduated AQP4 may mediate the focal concentration of cytosolic free calcium,which indicated that the AQP4 and Ca^2＋might participated the formation of intracellular edema. The results demonstrate that AQP4 plays an important role in the pathological course of the brain edema.

关 键 词：低渗培养液 水通道蛋白-4 钙离子 星形胶质细胞 

分 类 号：R329.2[医药卫生—人体解剖和组织胚胎学]