Abstract
Purpose: :
To investigate the effects of omega-3 polyunsaturated fatty acids (ω-3-PUFAs) on in vivo laser-induced choroidal neovascularization (CNV), and in vitro endothelial cell migration and tube formation.
Methods: :
We examined rats fed diets adequate (docosahexanoic acid (DHA) 1.3g/100g diet, α-linolenic acid (LNA) 2.6g/100g diet, n=5) or deficient (DHA un-detectable, LNA 0.04g/100g diet, n=4) in ω-3-PUFAs. We used an ND:YAG 532-nm laser to induce ~4 lesions per eye. Flatmounted specimens were imaged with a grid-confocal epifluorescent microscope and blood vessel volume was quantified using Volocity® software. Tube formation assays were conducted on human microvascular endothelial cells (HMVECs) on growth factor reduced matrigel, treated with or without DHA for 24h. We counted tube branch points from photographs (4x) in four fields per well. We used bovine retinal endothelial cells (BRECs) on fibronectin coated plates, treated with or without DHA or angiostatin in migration assays. A pipet tip was used to create an area without cells. After 24h and 48h, wells were examined for cell migration into scored areas.
Results: :
There was a 63% reduction (p ≤ 0.0002) in the volume of CNV lesions of rats fed with the ω-3-PUFA adequate diet (n= 20 lesions) relative to those fed the ω-3 deficient diet (n= 11 lesions). HMVECs in the DHA-free condition formed tubes with a mean (± SEM) of 64 (±2.5) branch points per field. HMVECs treated with DHA at 25 µM and 6.3 µM formed tubes with a mean of 68 (±2.8) and 74 (±2.4) branch points per field, respectively. In migration assays, BRECs appeared in scored areas within 24h and 48h. Treatments with 3.1 µM DHA for 24h decreased the number of BRECs in scored areas relative to those wells without DHA. However, migration of BRECs incubated with 25 µM DHA was not significantly different than the DHA-free controls after 24h. By 48h, only DHA at 3.1 µM showed decreased migration. Angiostatin at 10 nM and 100 nM inhibited migration of BRECs in this assay.
Conclusions: :
An increase of ω-3-PUFAs in the diet inhibited neovessel formation in an experimental rodent CNV model. DHA at 25 µM and 6.3 µM did not inhibit endothelial tube formation. DHA at 3.1 µM, but not at 25 µM, had an apparent inhibitory effect on endothelial cell migration.
Keywords: choroid: neovascularization • lipids