Lysosomal degradation of retinal glial AQP4 following its internalization induced by acute ocular hypertension

详细信息	查看全文 | 推荐本文 |

• 作者：Sheng-Wei Gan^a ; Jian-Hua Ran^a ; Hai Chen^b ; Zhong-Qin Ren^c ; Shan-Quan Sun^a ; ^{sunsq2151@cqmu.edu.cn} ; Shu-Juan Zhu^a ; Wei-Tian Lu^a ; Jin Xu^a ; Bo Zhang^a ; Juan Huang^a ; Ke-Jian Wang^a ; Zhen Chen^d
• 关键词：Aquaporin-4 ; Glial ; Endosome ; Lysosome ; Internalization ; Protein degradation
• 刊名：Neuroscience Letters
• 出版年：2012
• 期刊代码：52_03043940
• 类别：neu
• 出版时间：10 May, 2012
• 卷：516
• 期：1
• 页码：135-140
• 文件大小：1937 K

摘要

The membrane-bound water channel aquaporin-4 plays a significant role in the regulation of water movement within the retina. In retinal ischemia-reperfusion injury, changes in the expression and localization of aquaporin-4 have been reported. Previous studies also suggest that the internalization of several membrane-bound proteins, including aquaporin-4, may occur with or without lysosomal degradation. In this study, the internalization of aquaporin-4 was detected in the ischemic rat retina via double immunofluorescence labeling. Specifically, both aquaporin-4 and the mannose-6-phosphate receptor co-localized post-ischemic injury (10, 30 and 60 min). The same results were found during a 12-h reperfusion window (2, 4 and 8 h, respectively) following 60 min of ischemia. Moreover, the co-expression of aquaporin-4 and lysosomal-associated membrane protein-1 was observed at 1-12 h of reperfusion, with co-expression increasing followed by a gradual decrease. These combined findings suggest that AQP4 is internalized in the ischemic-reperfused retina, and the lysosome is involved in degrading the internalized aquaporin-4 during the reperfusion phase. Both the internalization of aquaporin-4 and its lysosomal degradation may serve as valuable therapeutic targets for managing ischemic-reperfused retinal injury.