| First Author | Talia DM | Year | 2016 |
| Journal | Arterioscler Thromb Vasc Biol | Volume | 36 |
| Issue | 6 | Pages | 1186-96 |
| PubMed ID | 27055905 | Mgi Jnum | J:246149 |
| Mgi Id | MGI:5921771 | Doi | 10.1161/ATVBAHA.115.307080 |
| Citation | Talia DM, et al. (2016) Inhibition of the Nuclear Receptor RORgamma and Interleukin-17A Suppresses Neovascular Retinopathy: Involvement of Immunocompetent Microglia. Arterioscler Thromb Vasc Biol 36(6):1186-96 |
| abstractText | OBJECTIVE: Although inhibitors of vascular endothelial growth factor (VEGF) provide benefit for the management of neovascular retinopathies, their use is limited to end-stage disease and some eyes are resistant. We hypothesized that retinoic acid-related orphan nuclear receptor gamma (RORgamma) and its downstream effector, interleukin (IL)-17A, upregulate VEGF and hence are important treatment targets for neovascular retinopathies. APPROACH AND RESULTS: Utilizing a model of oxygen-induced retinopathy, confocal microscopy and flow cytometry, we identified that retinal immunocompetent cells, microglia, express IL-17A. This was confirmed in primary cultures of rat retinal microglia, where hypoxia increased IL-17A protein as well as IL-17A, RORgamma, and tumor necrosis factor-alpha mRNA, which were reduced by the RORgamma inhibitor, digoxin, and the RORalpha/RORgamma inverse agonist, SR1001. By contrast, retinal macroglial Muller cells and ganglion cells, key sources of VEGF in oxygen-induced retinopathy, did not produce IL-17A when exposed to hypoxia and IL-1beta. However, they expressed IL-17 receptors, and in response to IL-17A, secreted VEGF. This suggested that RORgamma and IL-17A inhibition might attenuate neovascular retinopathy. Indeed, digoxin and SR1001 reduced retinal vaso-obliteration, neovascularization, and vascular leakage as well as VEGF and VEGF-related placental growth factor. Digoxin and SR1001 reduced microglial-derived IL-17A and Muller cell and ganglion cell damage. The importance of IL-17A in oxygen-induced retinopathy was confirmed by IL-17A neutralization reducing vasculopathy, VEGF, placental growth factor, tumor necrosis factor-alpha, microglial density and Muller cell, and ganglion cell injury. CONCLUSIONS: Our findings indicate that an RORgamma/IL-17A axis influences VEGF production and neovascular retinopathy by mechanisms involving neuroglia. Inhibition of RORgamma and IL-17A may have potential for the improved treatment of neovascular retinopathies. |
