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. 2016 Nov;13:201-211.
doi: 10.1016/j.ebiom.2016.09.025. Epub 2016 Sep 30.

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

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Free PMC article

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

Yan Gong et al. EBioMedicine. .
Free PMC article

Abstract

Neovascular eye diseases including retinopathy of prematurity, diabetic retinopathy and age-related-macular-degeneration are major causes of blindness. Fenofibrate treatment in type 2 diabetes patients reduces progression of diabetic retinopathy independent of its peroxisome proliferator-activated receptor (PPAR)α agonist lipid lowering effect. The mechanism is unknown. Fenofibrate binds to and inhibits cytochrome P450 epoxygenase (CYP)2C with higher affinity than to PPARα. CYP2C metabolizes ω-3 long-chain polyunsaturated fatty acids (LCPUFAs). While ω-3 LCPUFA products from other metabolizing pathways decrease retinal and choroidal neovascularization, CYP2C products of both ω-3 and ω-6 LCPUFAs promote angiogenesis. We hypothesized that fenofibrate inhibits retinopathy by reducing CYP2C ω-3 LCPUFA (and ω-6 LCPUFA) pro-angiogenic metabolites. Fenofibrate reduced retinal and choroidal neovascularization in PPARα-/-mice and augmented ω-3 LCPUFA protection via CYP2C inhibition. Fenofibrate suppressed retinal and choroidal neovascularization in mice overexpressing human CYP2C8 in endothelial cells and reduced plasma levels of the pro-angiogenic ω-3 LCPUFA CYP2C8 product, 19,20-epoxydocosapentaenoic acid. 19,20-epoxydocosapentaenoic acid reversed fenofibrate-induced suppression of angiogenesis ex vivo and suppression of endothelial cell functions in vitro. In summary fenofibrate suppressed retinal and choroidal neovascularization via CYP2C inhibition as well as by acting as an agonist of PPARα. Fenofibrate augmented the overall protective effects of ω-3 LCPUFAs on neovascular eye diseases.

Keywords: Choroidal neovascularization; Cytochrome P450 epoxygenase 2C; Fenofibrate; Omega-3 long-chain polyunsaturated fatty acids; Retinal neovascularization; Retinopathy.

Figures

Image 1
Fig. 1
Fig. 1
Fenofibrate suppressed retinal and choridal neovascularization in Pparα knockout mice. Wild-type (WT) C57BL/6 and Pparα knockout (KO) mice subjected to OIR (a, scale bar, 1 mm) or laser-induced CNV (b, scale bar, 500 μm; ON, optic nerve) were orally gavaged with fenofibrate (100 μg/g/day) or corn oil as vehicle control from P12 to P16 for OIR or for 7 days after laser photocoagulation. Retinal and choroidal whole-mount vessels were stained with isolectin GS-IB4 at P17 or 7 days after laser photocoagulation respectively. Fenofibrate reduced retinal (c, n = 10 mice/group) neovascularization (NV, white arrows) and laser-induced CNV lesion area (d, n = 17–23 mice/group) in both WT and Pparα KO mice. Retinal mRNA levels of Acox1 (e) and Pdk4 (f) were increased in WT and Pparα KO mice, normalized to cyclophilin A and related to WT vehicle control group. n = 6 mice/group. * P < 0.05; *** P < 0.001; n. s., not significant.
Fig. 2
Fig. 2
Fenofibrate at a low dose inhibited CYP2C8 activity without PPARα activation. (a) Fenofibrate (F) has different effects on PPARα and CYP2C pathways at different doses due to their different affinity to fenofibrate. (b) Tie2-driven CYP2C8 transgenic (Tg) and wild-type (WT) littermate mice were orally gavaged with fenofibrate (10 μg/g/day) or 10% DMSO as vehicle control for 5 days. Fenofibrate at the low dose reversed the induction of 19,20-EDP plasma levels in CYP2C8 Tg mice. n = 10 mice/group, * P < 0.05. The mRNA levels of CYP2C8 (c), Cyp2C29 (d), Acox1 (e) and Pdk4 (f) were not affected by fenofibrate at the low dose in both the WT and CYP2C8 Tg retina. n = 6 mice/group, n. s., not significant.
Fig. 3
Fig. 3
Fenofibrate at a low dose suppressed both retinal and choroidal neovascularization in mice overexpressing CYP2C8. Tie2-driven CYP2C8 overexpression transgenic (Tg) and wild-type (WT) littermate mice were subjected to OIR (a, scale bar, 1 mm) or laser-induced CNV (b, scale bar, 500 μm; ON, optic nerve). The mice were orally gavaged with fenofibrate (10 μg/g/day) or 10% DMSO as vehicle control from P12 to P16 for OIR or for 7 days after laser photocoagulation respectively. Retinal and choroidal whole-mount vessels were stained with isolectin GS-IB4 at P17 or 7 days after laser photocoagulation respectively. Fenofibrate at the lower dose suppressed the induction of retinal (c) neovascularization (NV, white arrows) and laser-induced CNV lesion area (d) in CYP2C8 Tg mice. n = 10–12 mice/group. * P < 0.05; *** P < 0.001.
Fig. 4
Fig. 4
Fenofibrate augmented the protective effects of ω-3 LCPUFAs against retinal and choridal neovascularization. Wild-type C57BL/6 mice fed with a ω-6 or ω-3 LCPUFA enriched diet were subjected to OIR (a, scale bar, 1 mm) or laser-induced CNV (b, scale bar, 500 μm; ON, optic nerve). The mice were orally gavaged with fenofibrate (100 μg/g/day) or corn oil as vehicle control from P12 to P16 for OIR or for 7 days after laser photocoagulation. Retinal and choroidal whole-mount vessels were stained with isolectin GS-IB4 at P17 or 7 days after laser photocoagulation respectively. Fenofibrate augmented the protective effects of ω-3 LCPUFAs on retinal (c) neovascularization (NV, white arrows) and laser-induced CNV lesion area (d). n = 10 mice/group. * P < 0.05; ** P < 0.01; *** P < 0.001.
Fig. 5
Fig. 5
19,20-EDP reversed the inhibition of angiogenesis ex vivo by fenofibric acid. Aortic rings (a) and choroidal explants (b) were treated with fenofibric acid (20 μM) or 1% DMSO as vehicle control, and 19,20-EDP (1 μM) or ethanol (ETOH) as vehicle control for 6 days after tissue planting. Scale bar, 1 mm. 19,20-EDP reversed the inhibition of aortic ring (c) and choroidal (d) sprouting by fenofibric acid. n = 6. ** P < 0.01.
Fig. 6
Fig. 6
DHA enhanced the inhibition of angiogenesis ex vivo by fenofibric acid. Aortic rings (a) and choroidal explants (b) were treated with fenofibric acid (20 μM) or 1% DMSO as vehicle control, and DHA (30 μM) or 10% BSA as vehicle control for 6 days after tissue planting. Scale bar, 1 mm. DHA enhanced the inhibition of aortic ring (c) and choroidal (d) sprouting by fenofibric acid. n = 6. * P < 0.05; ** P < 0.01; *** P < 0.001.
Fig. 7
Fig. 7
19,20-EDP reversed the inhibition of endothelial cell tubule formation and migration by fenofibric acid. Representative photos of HRMEC tubule formation (a) and scratch wound healing assays (b) treated with fenofibric acid (20 μM) or 1% DMSO as vehicle control, and 19,20-EDP (1 μM) or ETOH as vehicle control. Scale bar, 500 μm. Dashed lines indicate scratched area and white arrows indicate cell-free zone 24 h later. 19,20-EDP reversed the inhibition of endothelial cell tubule formation (c) and migration (d) by fenofibric acid. n = 6. * P < 0.05; ** P < 0.01; *** P < 0.001.
Fig. 8
Fig. 8
DHA enhanced the inhibition of human endothelial cell tubule formation and migration by fenofibric acid. Representative photos of HRMEC tubule formation (a) and scratch wound healing assays (b) with fenofibric acid treatment (20 μM) or 1% DMSO as vehicle control, and DHA (30 μM) or 10% BSA as vehicle control. Scale bar, 500 μm. Dashed lines indicate scratched area and white arrows indicate cell-free zone 24 h later. DHA enhanced the inhibition of endothelial cell tubule formation (c) and migration (d) by fenofibric acid. n = 6. *** P < 0.001.

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References

    1. Antonetti D.A., Klein R., gardner T.W. Diabetic retinopathy. N. Engl. J. Med. 2012;366:1227–1239. - PubMed
    1. Baker M., Robinson S.D., Lechertier T., Barber P.R., Tavora B., D'amico G., Jones D.T., Vojnovic B., Hodivala-Dilke K. Use of the mouse aortic ring assay to study angiogenesis. Nat. Protoc. 2012;7:89–104. - PubMed
    1. Bogdanov P., Hernandez C., Corraliza L., Carvalho A.R., SIMO R. Effect of fenofibrate on retinal neurodegeneration in an experimental model of type 2 diabetes. Acta Diabetol. 2015;52:113–122. - PubMed
    1. Cheung N., Lam D.S., Wong T.Y. Anti-vascular endothelial growth factor treatment for eye diseases. BMJ. 2012;344 - PubMed
    1. Chew E.Y., Ambrosius W.T., Howard L.T., Greven C.M., Johnson S., Danis R.P., Davis M.D., Genuth S., Domanski M., Group A.S. Rationale, design, and methods of the Action to Control Cardiovascular Risk in Diabetes Eye Study (ACCORD-EYE) Am. J. Cardiol. 2007;99:103i–111i. - PubMed

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