Dynamic functional contribution of the water channel AQP5 to the water permeability of peripheral lens fiber cells.
Dynamic functional contribution of the water channel AQP5 to the water permeability of peripheral lens fiber cells.
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水通道 AQP5 对周围晶状体纤维细胞透水性的动态功能贡献。
DOI：
10.1152/ajpcell.00214.2017
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Petrova RS
中科院分区：
文献类型：
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作者：
Petrova RS
虽然透镜水通道水通道蛋白1（AQP 1;上皮）和AQP 0（纤维细胞）的功能已被充分确立，但关于AQP 5在透镜中的作用知之甚少。由于在其他组织中，AQP 5作为一种受调节的水通道，其水渗透性（PH 2 O）比AQP 0高约20倍，因此AQP 5可以调节透镜纤维细胞中的PH 2 O。为了测试这种可能性，荧光染料稀释法被用来计算相对pH 20的上皮细胞和纤维膜囊泡分离的小鼠或大鼠透镜，在存在和不存在的氯化汞，AQP 1和AQP 5的抑制剂。免疫标记的透镜部分和纤维膜囊泡从小鼠和大鼠的晶状体揭示了不同物种之间的AQP 5在外皮层的亚细胞分布，AQP 5主要是在小鼠膜，但主要是在大鼠细胞质。相比之下，AQP 0标记总是膜在这两个物种。这种物种特异性的异质性AQP 5膜定位反映在测量的PH 2 O，只有纤维膜囊泡分离的小鼠透镜，表现出显着的Hg 2+敏感的贡献PH 2 O。当大鼠晶状体的第一个器官培养，免疫标记显示AQP 5插入皮质纤维细胞，并在膜囊泡中检测到Hg 2+敏感的PH 2 O显着增加。我们的研究结果表明，AQP 5在啮齿类动物透镜中形成功能性水通道，并且它们表明AQP 5的动态膜插入可能通过调节外皮层的PH 2 O来调节透镜中的水通量。
Although the functionality of the lens water channels aquaporin 1 (AQP1; epithelium) and AQP0 (fiber cells) is well established, less is known about the role of AQP5 in the lens. Since in other tissues AQP5 functions as a regulated water channel with a water permeability (PH2O) some 20 times higher than AQP0, AQP5 could function to modulate PH2Oin lens fiber cells. To test this possibility, a fluorescence dye dilution assay was used to calculate the relative PH2Oof epithelial cells and fiber membrane vesicles isolated from either the mouse or rat lens, in the absence and presence of HgCl2, an inhibitor of AQP1 and AQP5. Immunolabeling of lens sections and fiber membrane vesicles from mouse and rat lenses revealed differences in the subcellular distributions of AQP5 in the outer cortex between species, with AQP5 being predominantly membranous in the mouse but predominantly cytoplasmic in the rat. In contrast, AQP0 labeling was always membranous in both species. This species-specific heterogeneity in AQP5 membrane localization was mirrored in measurements of PH2O, with only fiber membrane vesicles isolated from the mouse lens, exhibiting a significant Hg2+-sensitive contribution to PH2O. When rat lenses were first organ cultured, immunolabeling revealed an insertion of AQP5 into cortical fiber cells, and a significant increase in Hg2+-sensitive PH2Owas detected in membrane vesicles. Our results show that AQP5 forms functional water channels in the rodent lens, and they suggest that dynamic membrane insertion of AQP5 may regulate water fluxes in the lens by modulating PH2Oin the outer cortex.