- [Show abstract] [Hide abstract] ABSTRACT: Purpose To study the expression of aquaporins 1 and 4 on blood retinal barrier cells during EAU.Methods Experimental Autoimmune Uveitis (EAU) was induced in C57Bl6 mice by immunization with interphotoreceptor retinoid-binding peptide 1-16. Four weeks later animal were sacrificed. The severity of the disease was graded and the expression of AQP1 and AQP4 were detected by immunofluorescence (IF). In vitro using ARPE-19 cells, basal expression of AQP1 and 4 was analysed by RT-PCR, Western blot(WB) and IF. The effects of IFN-gamma and TNF-alpha on AQP1 and AQP4 expression in ARPE-19 cells were determined by WB.Results In controls animals, AQP1 expression was limited to the photoreceptor layer while AQP4 expression extended from the internal limiting membrane to the external limiting membrane. The patterns of AQP1 and AQP4 expressions were not changed during uveitis. Neither AQP1 nor AQP4 were found in RPE cells in controls or EAU animals. However AQP4 was expressed in ARPE-19 cells and its expression somewhat upregulated by IFN-gamma and TNF-alpha.Conclusion The patterns of AQP1 and AQP4 expressions in the internal blood retinal barrier are not modulated during EAU. Besides, in vivo, the AQP1 or AQP4 expressions could not be detected on the external blood retinal barrier (RPE cells). In contrast, in vitro, AQP4 expression was detected in a human ARPE cell line and slightly increased by proinflammatory cytokines.