Regulation of RPE barrier function by all-trans retinoic acid in myopia

To investigate the effect of all-trans retinoic acid (atRA) on the barrier function of myopia retinal pigment epithelium (RPE), primary RPE cells from guinea pigs were cultured on the filters as monolayer and treated with 10⁻⁹ M atRA. Epithelial permeability was measured by transepithelial electrical resistance (TER) and HRP concentration, western blot was used to observe the expression of intercellular junction-associated proteins. Treatment of primary cultures of confluent myopia RPE cells with atRA resulted in a progressive increase in TER and a progressive decrease of HRP concentration in the basolateral compartment. The expression of E-cadherin, Occludin and Claudin-1 proteins were up-regulated after treatment with atRA for 6h to 48 h. We concluded that atRA could promote the epithelial barrier function of myopia RPE monolayer possibly by regulating expression of intercellular junction-associated proteins.