Age-related Maculopathy Susceptibility2(ARMS2) Participates In The Phagocytosis Functions Of The Retinal Pigment Epithelium

Purposes: To study the expression of age-related maculopathy susceptibility2(ARMS2) in the ARPE-19cells and in human retina, and to observe the effect of ARMS2on the phagocytosis of latex beads by the ARPE-19cells, then to investigate a potentialrole for this molecule in the development of the age-related macular degeneration.Methods: We have used immunofluorescence, reverse transcriptase PCR todemonstrate the presence and location of ARMS2in the ARPE-19cells and in humanretina. siRNA technology was used to knock down ARMS2mRNA and to study the effectof such knockdown on the phagocytosis of latex beads by the ARPE-19cells at differenttime points.Results: ARMS2is present in the ARPE-19cells and in human retina. In ARPE-19cells, ARMS2is localized in the cytosol of the perinuclear region. In human retina,ARMS2is expression in RPE and is enrichment in the apical surface which have a largenumber of microvilli. The expression of ARMS2in ARPE-19cells transfected withARMS2-siRNA (0.73±0.08) was decreased obviously when compared with normal cells(1.00±0.00) or cells transfected with scrambled siRNA (0.95±0.13), p＜0.05. Afterincubated the cells with latex beads medium for12,18, or24hours, the fluorescenceintensity of ARMS2-siRNA transfected groups were38.04±1.02，68.92±0.92，78.00±0.12respectively, and the fluorescence intensity of scrambled siRNA transfected groups were 77.98±5.43，94.87±0.60，98.30±0.11respectively. We compared the two groups using theStudent’s t-test, p values were all less than0.01at different time points.Conclusions: There are endogenous expression of ARMS2both in ARPE-19cells andin human retina. ARMS2may play a role in phagocytosis of latex beads by the RPE andthis may be one of the mechanism that they participate in the development of AMD.