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Mingzhu Yang; P2X7 antagonist attenuates retinal inflammation and neovascularization induced by oxidized low density lipoprotein in mice. Invest. Ophthalmol. Vis. Sci. 2019;60(9):368.
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© ARVO (1962-2015); The Authors (2016-present)
To investigate whether A740003, a P2X7 receptor antagonist, could prevent retinal inflammation and neovascularization induced by oxidized low density lipoprotein (ox-LDL) and to explore the underlying mechanisms in human RPE cells and in mice.
ARPE-19 cells were incubated with A740003 for 2 hours before ox-LDL treatment. Same concentrations of DMSO were used as vehicle controls. C57BL/6 mice were subretinally injected with ox-LDL to induce retinal inflammation and neovascularization and PBS was used as control. A740003 (30 mg/kg/d) or vehicle was administrated intraperitoneally starting from day 3 before to day 14 after ox-LDL injection (n=6). Retinal neovascularization was detected by whole flat mount of retinas stained with isolectin-B4, CD31 and VEGF antibodies. Retinal function was assessed by dark- and light-adapted ERG. The mRNA and protein levels of NLRP3, Caspase-1, pIKBα, IKBα, HIF-1α and VEGF in retinas of mice and ARPE-19 cells were detected by qPCR and Western bloting. IL-1β, IL-18 and TNF-α were determined by ELISA assay.
Compared to vehicle group, A740003 decreased the expression of NLRP3, Caspase-1, HIF-1α and VEGF in ARPE-19 cells at RNA and protein levels. Inflammatory cytokines including IL-1β, IL-18, TNF-α and phosphorylation of IKBα was also down-regulated by A740003. Whole flat mount of retinas showed that A740003 inhibited the angiogenesis in retinas induced by ox-LDL. Compared with vehicle treated mice, the mRNA and protein levels of NLRP3 Caspase-1, HIF-1α and VEGF decreased and the phosphorylation of IKBα was inhibited in the retinas of A740003 treated mice. The b- and a-wave amplitudes of ERG were alleviated in the A740003 treated mice compared with vehicle group.
A740003 significantly reduced ocular inflammatory responses and VEGF level in ARPE-19 cells. In addition, the P2X7 antagonist inhibited retinal inflammation and neovascularization, and protected retinal function in ox-LDL induced impairment in mice. The protective effects of A740003 were associated with regulating of NLRP3 inflammasome and NF-κB pathway, as well as inhibition of HIF-1α and VEGF.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.
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