Purchase this article with an account.
Claire H. Mitchell, Sonia Guha, Gabriel Baltazar, Jason C. Lim, Thor Eysteinsson, Alan M. Laties; Release Of Il-6 And MCP-1 From Rpe Cells Follows Stimulation Of The P2X7 Receptor For ATP. Invest. Ophthalmol. Vis. Sci. 2011;52(14):1227.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Inflammatory signals around RPE cells contribute to the pathology in age-related macular degeneration. The mechanisms controlling release of cytokines from RPE cells are key in this regard. In several immune cells, stimulation of the P2X7 receptor (P2X7R) by agonist ATP leads to the release of IL-1β and other cytokines. Extracellular ATP activates a variety of receptors on RPE cells. We asked whether P2X7R agonists triggered cytokine release from RPE cells and began to probe the release pathways.
ARPE-19 cells were exposed to P2X7R agonist BzATP and extracellular levels of cytokines determined using standard Elisa assays. Ca2+ was determined using Fura-2 and lysosomal pH using Lysosensor Yellow/Blue. Gene levels were determined using qPCR.
P2X7R agonist BzATP triggered a significant release of IL-6 and MCP-1, but not IL-1β, into the extracellular bath. Release was rapid, occurring within a few minutes. The release of IL-6 following BzATP application was prevented by the removal of extracellular Ca2+, consistent with the increase in intracellular Ca2+ by BzATP. BzATP also raised lysosomal pH; this alkainization was blocked by inhibitors Brilliant Blue G and A438079. Further, P2X7R stimulation acted synergistically with oxidized photoreceptor outer segments to increase expression of genes for IL-6 and MCP-1.
Stimulation of the P2X7R on RPE cells raised Ca2+, elevated lysosomal pH and enhanced cytokine release.
This PDF is available to Subscribers Only