水通道蛋白4和内向整流性钾通道4.1在星形细胞瘤组织中的共定位及表达差异

Collocation and expression variations of aquporin4 and inward rectifying potassium channel 4.1 in astrocytoma

摘要:

目的：观察水通道蛋白4（aquaporin4，AQP4）与内向整流性钾通道4.1（inward rectifying potassium channel 4.1，Kir4.1）在人不同病理级别星形细胞瘤组织中的共定位现象及其二者的表达差异，探讨星形细胞瘤增殖、生长的病理机制。方法：共收集人不同病理级别星形细胞瘤标本50例。采用石蜡切片HE、激光共聚焦和Western blot分析，以肿瘤周围相对正常脑组织作为对照，观察AQP4与Kir4.1的共定位及其蛋白表达差异。结果：AQP4和Kir4.1在人不同病理级别星形细胞瘤组织中并没有完全共定位；与正常脑组织相比，人星形细胞瘤组织Kir4.1表达上调，并随着星形细胞瘤病理级别的升高表达增强。而AQP4在低级别肿瘤组织中却表达减弱，在高级别肿瘤组织中表达又逐渐增强。结论：AQP4和Kir4.1在各级别肿瘤组织中没有完全共定位，二者的蛋白含量与肿瘤病瘤级别相关，并表现出不同的变化规律，提示二者在肿瘤组织水与离子平衡的维持中可能具有不同的作用。

Abstract:

Objectives：To investigate the collocation and expression variations of aquporin4（AQP4） and inward rectifying potassium channel 4.1（Kir4.1） in astrocytoma of different pathological grades in order to discuss the pathomechanism of proliferation and growth in astrocytoma. Methods：Fifty astrocytoma samples of different pathologic grades were obtained and the relative normal brain tissues contributed to controls. Expression and collocation of AQP4 and Kir4.1 were detected by HE staining，laser scanning confocal mi－croscopy technology and Western blot. Results：Uncomplete collocation of AQP4 and Kir4.1 was present in astrocytoma. Expression of Kir4.1 at protein level was increased along with the ascending pathologic grade. However，expression of AQP4 at protein level was decreased in low-grade astrocytoma and was increased in high-grade astrocytoma. Conclusions：Uncomplete collocation of AQP4 and Kir4.1 is present in astrocytoma. Protein levels of AQP4 and Kir4.1 are correlated with pathological grade of astrocytoma and the vari－ations of AQP4 and Kir4.1 are different. These data suggest that AQP4 and Kir4.1 respectively play different roles in maintaining water and ionic balance.