Purchase this article with an account.
Roy Chze Khai Chze Khai Kong, Alison J Cox, Sylwia Glowacka, Darren J. Kelly, Fay Khong; OCX063, A Novel Small Molecule Drug, Exhibits Anti-Inflammatory and Anti-Fibrotic Properties in Retinal Cultures. Invest. Ophthalmol. Vis. Sci. 2017;58(8):1204. doi: https://doi.org/.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Retinal microglia are the resident immune cells in the central nervous system, which undergo activation and release inflammatory cytokines in injury. During injury, Muller cells can also become activated and exhibit a fibroblast-like phenotype. Since it has been shown that microglia and Muller cells interact functionally, we hypothesize that inhibiting inflammatory cytokine release from activated microglia can have anti-inflammatory/anti-fibrotic effects on Muller cells. We tested this using OCX063 which we have shown to be anti-inflammatory in mesenchymal and immune cells.
To assess OCX063’s effect on activated microglia, primary rat retinal microglia were induced using low pH6.8 medium, in the presence of 10, 30 and 100μM OCX063. Low pH induction was chosen to mimic an acidified extracellular environment, representative of metabolic abnormality as seen in inflammatory/proliferative retinal diseases. We then co-cultured microglia under these conditions with non-activated Muller cells in a Transwell system. Cells were analyzed for inflammatory and fibrotic markers via RT-qPCR/ELISA.
pH6.8 caused an inflammatory phenotype in microglia as shown by the significantly elevated expression of interleukin (IL) 6 and IL1β gene and protein, compared to physiological pH7.6. Excitingly, the gene expression of IL6 and IL1β was decreased by 100μM OCX063 (both p<0.05) while their protein expression was decreased by OCX63 at concentrations as low as 10μM (IL6, p<0.01; IL1β, p<0.05). Subsequent co-culture of Muller cells with activated microglia also led to significant up-regulation of inflammatory and fibrotic gene markers in Muller cells including IL6, IL1β and inducible nitric oxide synthase (iNOS) as well as collagen type IV (ColIV) and matrix metalloproteinase-9 (MMP9), respectively. As hypothesized, these pathological effects were reduced when the Muller cells were co-cultured with OCX063-treated (30μM) microglia (IL6, p<0.01; IL1β, p<0.05; iNOS, p<0.05; ColIV, p<0.05; MMP9, p<0.001).
Our findings show that OCX063 not only exerts anti-inflammatory effects on retinal microglia, but also has protective anti-inflammatory/anti-fibrotic effects on other cells, like Muller cells, which exhibit pathological phenotypes due to microglial activation. Thus, OCX063 may be a strategy for treating proliferative retinal diseases.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.
This PDF is available to Subscribers Only