Cytochrome P450 Oxidase 2C Inhibition Adds to ω-3 Long-Chain Polyunsaturated Fatty Acids Protection Against Retinal and Choroidal Neovascularization

Abstract

Objective Pathological ocular neovascularization is a major cause of blindness. Increased dietary intake of ω-3 long-chain polyunsaturated fatty acids (LCPUFA) reduces retinal and choroidal neovascularization, but ω-3 LCPUFA metabolites of a major metabolizing pathway, cytochrome P450 oxidase (CYP) 2C, promote ocular pathological angiogenesis. We hypothesized that inhibition of CYP2C activity will add to the protective effects of ω-3 LCPUFA on neovascular eye diseases. Approach and Results The mouse models of oxygen-induced retinopathy (OIR) and laser-induced choroidal neovascularization (CNV) were used to investigate pathological angiogenesis in the retina and choroid respectively. The plasma levels of ω-3 LCPUFA metabolites of CYP2C were determined by mass spectroscopy. Aortic ring and choroidal explant sprouting assays were used to investigate the effects of CYP2C inhibition and ω-3 LCPUFA derived CYP2C metabolic products on angiogenesis ex vivo. We found that inhibition of CYP2C activity by montelukast added to the protective effects of ω-3 LCPUFA on retinal and choroidal neovascularization by 30% and 20% respectively. In CYP2C8 over-expressing mice fed a ω-3 LCPUFA diet, montelukast suppressed retinal and choroidal neovascularization by 36% and 39% and reduced the plasma levels of CYP2C8 products. Soluble epoxide hydrolase inhibition, which blocks breakdown and inactivation of CYP2C ω-3 LCPUFA-derived active metabolites, increased OIR and CNV in vivo. Exposure to selected ω-3 LCPUFA metabolites of CYP2C significantly reversed the suppression of both angiogenesis ex vivo and endothelial cell functions in vitro by the CYP2C inhibitor montelukast. Conclusion Inhibition of CYP2C activity adds to the protective effects of ω-3 LCPUFA on pathological retinal and choroidal neovascularization.

Fenofibrate Inhibits Cytochrome P450 Epoxygenase 2C Activity to Suppress Pathological Ocular Angiogenesis

“…The ω-3 LCPUFA, DHA, inhibits angiogenesis ex vivo and endothelial functions in vitro, which is consistent with previous publications and likely related to its metabolites produced through cyclooxygenase and lipoxygenase, rather than through CYP pathways (Sapieha et al, 2011, Szymczak et al, 2008, Gong et al, 2016). The different effects reported on CNV of an exogenously delivered single ω-3 LCPUFA CYP metabolite might result from a different plasma concentration due to exogenous administration rather than an evaluation of the sum total of all metabolites after inhibition of CYP2C activity(Yanai et al, 2014, Gong et al, 2016). DHA supplementation did not reverse the angiogenesis inhibitory effects of fenofibrate, but further increased the suppression of angiogenesis, suggesting that DHA on balance was metabolized by other enzymes into anti -angiogenic metabolites and that fenofibrate functioned downstream of DHA.…”

Retinal energy demands control vascular supply of the retina in development and disease: The role of neuronal lipid and glucose metabolism

“…The biological impact of altering lipid intake is thought to be primarily through modification of membrane microdomain composition and specific receptors. Dietary ω3 to ω6 fatty acids may, therefore, impact retinal function and retinal neovascularization (Connor et al, 2007; Fu et al, 2015; Gong et al, 2015, 2016a, 2016b, 2017; Hård et al, 2013; Rezende et al, 2014; Sapieha et al, 2011, 2012; Shao et al, 2014; Stahl et al, 2010). There is no evidence these essential fatty acids are used for fuel, and without adequate synthetic machinery, it would be surprising if they were not used primarily in other capacities.…”

Dyslipidemia in retinal metabolic disorders

“…LOX ω‐3 LCPUFA metabolites show anti‐inflammatory and anti‐angiogenic effects, while LOX ω‐6 LCPUFA metabolites are pro‐inflammatory and pro‐angiogenic (Sapieha et al , ). However, both CYP2C8 ω‐3 and ω‐6 LCPUFA metabolites are pro‐angiogenic and inhibition of CYP2C8 decreases ocular neovascularization (Shao et al , ; Gong et al , ,b).…”

“…Fenofibrate is also a CYP2C antagonist (Schoonjans et al, 1996;Walsky et al, 2005). CYP2C metabolites from x-3 and x-6 LCPUFA show pro-angiogenic effects in mouse models of ROP and AMD (Shao et al, 2014;Gong et al, 2016a). Inhibition of CYP2C with fenofibrate decreases retinal neovascularization (Gong et al, 2016b).…”