Eicosapentaenoic acid is anti-inflammatory in preventing choroidal neovascularization in mice.
OBJECTIVE
To investigate the role of eicosapentaenoic acid (EPA), the major omega-3 polyunsaturated fatty acid (PUFA), in the development of choroidal neovascularization (CNV), together with underlying molecular mechanisms.


METHODS
Six-week-old C57BL/6 mice were fed with laboratory chow with 5% EPA or the omega-6 PUFA linoleic acid (LA) for 4 weeks. Laser photocoagulation was performed to induce CNV, and the volume of CNV tissue was evaluated by volumetric measurements. The expression and production of intercellular adhesion molecule (ICAM)-1, monocyte chemotactic protein (MCP)-1, vascular endothelial growth factor (VEGF) and interleukin (IL)-6 in the retinal pigment epithelium (RPE)-choroid in vivo, and stimulated b-End3 endothelial cells and RAW264.7 macrophages in vitro were evaluated by RT-PCR and ELISA. Fatty acid composition in the serum and the RPE-choroid was analyzed by gas chromatography and high-performance liquid chromatography, respectively. Serum levels of C-reactive protein (CRP), IL-6, VEGF, MCP-1, and soluble ICAM-1 were examined by ELISA.


RESULTS
The CNV volume in EPA-fed animals was significantly suppressed compared with that in control mice, whereas the LA-rich diet did not affect CNV. The mRNA expression and protein levels of ICAM-1, MCP-1, VEGF, and IL-6 after CNV induction were significantly reduced in EPA-supplemented mice. In vitro, EPA application led to significant inhibition of mRNA and protein levels of ICAM-1 and MCP-1 in endothelial cells and VEGF and IL-6 in macrophages. EPA-fed mice exhibited significantly higher levels of EPA and lower levels of the omega-6 PUFA arachidonic acid in the serum and the RPE-choroid than control animals. EPA supplementation also led to significant reduction of serum levels of IL-6 and CRP after CNV induction.


CONCLUSIONS
The present study demonstrates for the first time that an EPA-rich diet results in significant suppression of CNV and CNV-related inflammatory molecules in vivo and in vitro. These results suggest that frequent consumption of omega-3 PUFAs may prevent CNV and lower the risk of blindness due to age-related macular degeneration.
Koto
Takashi
T
Laboratory of Retinal Cell Biology, Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan.
Nagai
Norihiro
N
Mochimaru
Hiroshi
H
Kurihara
Toshihide
T
Izumi-Nagai
Kanako
K
Satofuka
Shingo
S
Shinoda
Hajime
H
Noda
Kousuke
K
Ozawa
Yoko
Y
Inoue
Makoto
M
Tsubota
Kazuo
K
Oike
Yuichi
Y
Ishida
Susumu
S
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage*; D018932:Chemokine CCL2 / Q000235:genetics / Q000378:metabolism; D002829:Choroid / Q000378:metabolism / Q000601:surgery; D020256:Choroidal Neovascularization / Q000378:metabolism / Q000517:prevention & control*; D002849:Chromatography, Gas; D002851:Chromatography, High Pressure Liquid; D004032:Diet; D004195:Disease Models, Animal; D015118:Eicosapentaenoic Acid / Q000008:administration & dosage*; D004730:Endothelium, Vascular / Q000187:drug effects; D004797:Enzyme-Linked Immunosorbent Assay; D005227:Fatty Acids / Q000097:blood; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D017075:Laser Coagulation; D019787:Linoleic Acid / Q000008:administration & dosage; D008264:Macrophages / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D010857:Pigment Epithelium of Eye / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism
D000893:Anti-Inflammatory Agents; C491768:Ccl2 protein, mouse; D018932:Chemokine CCL2; D005227:Fatty Acids; C090509:Icam1 protein, mouse; D015850:Interleukin-6; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse; D018799:Intercellular Adhesion Molecule-1; D019787:Linoleic Acid; D015118:Eicosapentaenoic Acid