Nutrient supplementation with n3 polyunsaturated fatty acids, lutein, and zeaxanthin decrease A2E accumulation and VEGF expression in the retinas of Ccl2/Cx3cr1-deficient mice on Crb1rd8 background

J Nutr. 2013 Jul;143(7):1129-35. doi: 10.3945/jn.112.169649. Epub 2013 May 15.

Abstract

The Age-Related Eye Diseases Study 2 (AREDS2) clinical trial is assessing the effects of higher dietary xanthophyll (lutein and zeaxanthin) and long-chain n3 polyunsaturated fatty acid (LCPUFA) docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) intake on progression to advanced age-related macular degeneration (AMD). This study's purpose was to examine the retinal effects of the AREDS2 formulation on Chemokine (C-C motif) ligand 2 (Ccl2(-/-))/CX3C chemokine receptor 1 (Cx3cr1(-/-)) mice on Crumbs homolog 1 retinal degeneration phenotype 8 (Crb1(rd8)) background (DKO), which develop focal retinal lesions with certain features similar to AMD. DKO and C57BL/6N rd8 background mice (WT) were bred and randomized into 4 groups. Two groups, WT mice on AREDS2 diet (A-WT) and DKO mice on AREDS2 diet (A-DKO), were supplemented daily with 1.76 μmol of lutein, 35.1 μmol of zeaxanthin, 215 μmol EPA, and 107 μmol of DHA, and 2 control groups, WT mice on control diet (C-WT) and DKO mice on control diet (C-DKO), were fed an isocaloric diet. All mice had monthly fundus photos and were killed after 3 mo for biochemical and histologic analyses. After 3 mo, 81% of A-DKO mice had lesion regression compared with 25% of C-DKO mice (P < 0.05). Toxic retinal 2-[2,6-dimethyl-8-(2,6,6-trimethyl-1-cyclohexen-1-yl)-1E,3E,5E,7E-octatetra-enyl]-1-(2-hydroxyethyl)-4-[4-methyl-6(2,6,6-trimethyl-1-cyclohexen-1-yl) 1E,3E,5E,7E-hexatrienyl]-pyridinium (A2E) concentrations were significantly lower in A-DKO compared with C-DKO mice. The outer nuclear layer thickness in A-DKO mice was significantly greater than that in C-DKO mice. Retinal expression of inducible nitric oxide synthase (iNos) tumor necrosis factor-α (Tnf-α), Cyclooxygenase-2 (Cox-2), interleukin1beta (IL-1β), and vascular endothelial growth factor (Vegf) was significantly lower in A-DKO compared with C-DKO mice. Xanthophylls and LCPUFAs have antiinflammatory, neuroprotective, and antiangiogenic properties. Our data provide potential mechanisms by which the AREDS2 formula has a protective effect on retinal lesions in DKO mice.

Publication types

  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiogenesis Inhibitors / administration & dosage
  • Animals
  • Anti-Inflammatory Agents / administration & dosage
  • CX3C Chemokine Receptor 1
  • Chemokine CCL2 / genetics
  • Chemokine CCL2 / metabolism
  • Cyclooxygenase 2 / genetics
  • Cyclooxygenase 2 / metabolism
  • Dietary Supplements*
  • Docosahexaenoic Acids / administration & dosage*
  • Eicosapentaenoic Acid / administration & dosage*
  • Gene Expression Profiling
  • Interleukin-1beta / genetics
  • Interleukin-1beta / metabolism
  • Lutein / administration & dosage*
  • Macular Degeneration / drug therapy
  • Macular Degeneration / genetics
  • Macular Degeneration / pathology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Microscopy, Electron, Transmission
  • Nitric Oxide Synthase Type II / genetics
  • Nitric Oxide Synthase Type II / metabolism
  • Phenotype
  • Pyridinium Compounds / pharmacokinetics
  • Receptors, Chemokine / genetics
  • Receptors, Chemokine / metabolism
  • Retina / drug effects
  • Retina / metabolism
  • Retinal Degeneration / drug therapy
  • Retinal Degeneration / genetics
  • Retinal Degeneration / pathology
  • Retinoids / pharmacokinetics
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / metabolism
  • Vascular Endothelial Growth Factor A / genetics*
  • Vascular Endothelial Growth Factor A / metabolism
  • Xanthophylls / administration & dosage*
  • Zeaxanthins

Substances

  • A2-E (N-retinylidene-N-retinylethanolamine)
  • Angiogenesis Inhibitors
  • Anti-Inflammatory Agents
  • CX3C Chemokine Receptor 1
  • Ccl2 protein, mouse
  • Chemokine CCL2
  • Cx3cr1 protein, mouse
  • Interleukin-1beta
  • Pyridinium Compounds
  • Receptors, Chemokine
  • Retinoids
  • Tumor Necrosis Factor-alpha
  • Vascular Endothelial Growth Factor A
  • Xanthophylls
  • Zeaxanthins
  • vascular endothelial growth factor A, mouse
  • Docosahexaenoic Acids
  • Eicosapentaenoic Acid
  • Nitric Oxide Synthase Type II
  • Nos2 protein, mouse
  • Ptgs2 protein, mouse
  • Cyclooxygenase 2
  • Lutein