星形胶质细胞水通道4表达变化与胶质瘤性脑水肿的关系

Relationship between aquaporin-4 expression in astrocytes and brain edema caused by glioma

目的研究脑胶质瘤细胞对体外血脑屏障模型水转运及星形胶质细胞水通道4的影响。方法利用重水的荧光特性及高效液相系统检测体外血脑屏障模型对水转运的变化。采用半定量RT-PCR的方法分析胶质瘤细胞作用后星形胶质细胞水通道4的表达变化。结果胶质瘤细胞可以明显增强体外血脑屏障模型对水由内皮细胞腔面至基底面的扩散。这一过程不依赖于白蛋白等大分子物质的通透性变化。同时,胶质瘤细胞明显降低了胶质细胞水通道4的表达水平。结论胶质瘤细胞可以明显增强体外血脑屏障模型对水由内皮细胞腔面向基底面的扩散。胶质瘤性脑水肿不一定是血浆中大分子物质通透性增加的结果。胶质瘤细胞对胶质细胞水通道4的影响可能是胶质瘤性脑水肿产生的分子机制之一。

Objective To investigate the relationship between aquaporin-4 (AQP4) water channel expression in astrocytes and brain edema caused by glioma. Methods The changes of water transport in in vitro blood-brain barrier models were examined using high-performance liquid chromatography (HPLC), and the expression level of AQP4 was assayed by semiquantitative RT-PCR. Results The water transport of the in vitro blood-brain barrier model from the luminal side to basolateral side was increased after coculture with glioma cells, which induced significantly decreased expression level of AQP4 in the astrocytes. Conclusions Glioma cells can promote water transport in in vitro blood-brain barrier model from the luminal side to abluminal side, and the brain edema induced by the glioma cells may not necessarily be the result of hyperpermeability of the blood-brain barrier to macromolecules in the plasma. The decreased expression level of AQP4 induced by glioma cells may be a molecular mechanism for neoplastic brain edema in patients with glioma.