Abstract
Purpose:
The development of certain ocular diseases is associated with some environmental factors. Excess sodium chloride (Nacl) uptake is one of the most common environmental risk factors in a various diseases. In this study, we investigated whether the Nacl could directly influence the production of inflammatory cytokines by ARPE-19 cell, an immortalized cell line which has structural and functional properties characteristic of human RPE cells.
Methods:
ARPE-19 cells were cultured with LPS in the presence or absence of 20nM and 40nM Nacl. Mannitol was used to exclude the effect of osmotic pressure. The expression of IL-6, IL-8, MCP-1 and VEGF in ARPE-19 cells were detected by ELISA. Cell proliferation was determined by WST-8 assay using Cell Counting Kit-8. Flow cytometry were performed to study the effect of Nacl on cell apoptosis.
Results:
The concentration of 20nM Nacl did not show any effect on the expression of inflammatory cytokines. However, 40nM Nacl could significantly induced the expression of IL-6, IL-8, MCP-1 and VEGF in LPS-stimulated ARPE-19 cells. The osmotic pressure equaled to that of 40nM Nacl had no influence on the production of these four cytokines. There was no effect of 40nM Nacl on the proliferation and apoptosis of ARPE-19 cells.
Conclusions:
A concentration of 40nM Nacl could directly induce the expression of inflammatory cytokines in ARPE-19 cells. These results suggest that excess Nacl uptake may play a role in regulating RPE function and is possibly involved in the development of inflammatory diseases in the retina or choroid.