急性高眼压大鼠视网膜胶质细胞水通道蛋白-4的内化

Internalization of retinal glial aquaporin-4 induced by acute ocular hypertension

目的：观察急性高眼压时大鼠视网膜胶质细胞水通道蛋白-4（AQP4）内化的时空变化及其规律,并探讨其与视网膜水肿的关系.方法：建模并分组；应用免疫荧光双标鉴定视网膜AQP4阳性细胞；观察AQP4与早期内涵体抗原1（EEA1）及晚期内涵体标记物甘露糖-6-磷酸受体（MPR）的共表达规律.结果：在正常视网膜内,表达AQP4的星形胶质细胞胞体位于节细胞层,Müller细胞的胞体位于内核层.正常及假手术组未见AQP4与EEA-1、MPR的共表达；高眼压作用不同时间,AQP4与EEA1共表达细胞的分布部位及其占AQP4阳性细胞比例都有改变,在高眼压作用60 min,AQP4与EEA1共表达细胞的比例达到最高值,AQP4与MPR共表达细胞分布的部位也有变化.结论：高眼压可诱导视网膜胶质细胞AQP4的内化,即AQP4经过内吞进入早期内涵体,再转运至晚期内涵体.AQP4的内化可能对肿胀的胶质细胞起保护作用.

Objective： To investigate the dynamic spatiotemporal regularity of retinal aquaporin-4 （AQP4） and the occurrence of AQP4 internalization under acute ocular hypertension （AOH）, so as to study the possible role of its internalization in the glial edema of retina. Methods ： The animal models of AOH were made by perfusing D-hanks buffer into the anterior chamber of rats, and double-immunofluorescence labelings were applied to identity the retinal glial cells and detect the co-expression of AQP4~EEA1 and AQP4^-MPtL Results： Double irnmunofluorescence labelings demonstrated that the cell bodies of astrocytes were located in the ganglion cell layer, while the Mialler cells in the inner nuclear layer; The distribution and proportion of AQP4~EEA1 co-expressing cells and distribution of AQP4~MPR was varied in different AOH groups： AQP4~EEA1 were co-localized in the ganglion cell layer from 5 min to 90 min of ocular hypertension, yet in the inner nuclear layer from 10 to 90 min; At the 60 min of AOH, proportion of AQP4 ~EEA1 co-expressing cells climaxed, occupying 72.97 % 9. 89 % in ganglion cell layer and 58. 94 % ~ 10. 03 ~ in the inner nuclear layer. AQP48~MPR were co-localized from 10 min to 60 min of AOH. Conelusion： AQP4 internalization can be induced by AOH. During this procedure, AQP4 is transported from the membrane to the early endosome, and then to late endosome, which has a potential protective effect on the swollen glial cells.