Eeffect Of All-trans Retinoic And Acid On The Barrier Function In Human Reginal Pigment Epithelial Cells

Objective:To investigate the effects of all-trans Retinoic Acid (atRA) on the barrier function in human retinal pigment epithelial (RPE) cells.Methods:A human RPE cell line (ARPE-19) were cultured on the filters as monolayer and atRA was added in the apical side. Transepithelial electrical resistance (TER) of confluent RPE cells was measured by epithelial voltmeter. The permeability of the RPE cells to horseradish peroxidase (HRP) was measured. The expressions of tight junctions (TJ)-associated proteins were determined by Western Blot and immunofluorescence analysis.Results:Within a certain range of concentration (10-7 to10-8M), atRA dose-dependently maintained the increased TER in ARPE-19 cells during a long-term culture. A significantly decrease of HRP permeability occurred in 10-6M atRA-supplemented medium than in other mediums. The expression of ZO-1 and occludin were upregulated in 10'7M atRA-supplemented medium than in other mediums.Conclusions:atRA provides barrier-positive elements to the RPE cell, and the atRA bioavailability regulates the epithelial barrier accompanied by altering expression of tight junctions (TJ)-associated proteins.