Aquaporins (AQPs) are a family of transmembrane channel proteins permeable to water. They are likely to play an essential role in the outer blood retinal barrier allowing passive water transport through the retinal pigmented epithelium (RPE). The identification of AQPs expressed in the RPE could contribute to a better understanding of the development of macular edema in several eye diseases such as diabetic retinopathy. However, the type of AQPs expressed by the RPE is currently a subject of controversy.Methods
We investigated the expression of AQPs in the human RPE cell line ARPE-19, a model of human RPE. First, AQPs mRNA expression was determined by quantitative real-time PCR (qRT-PCR). Furthermore, protein expression was analyzed by both immunofluorescence (IF) and Western blot (WB).Results
The mRNA of AQP1, AQP4, AQP6 and AQP11 were expressed in ARPE-19 cells. However, the expression of AQP3, AQP4, AQP6, AQP7, AQP8, AQP9, AQP11 and AQP12 were found by IF. Finally, the expression of AQP4 and AQP6 was found by WB.Conclusion
In conclusion, several AQPs were detected both at the mRNA and at the protein level in ARPE-19 cells and may account for water movement in those cells.