Characterizing the effect of supplements on the phenotype of cultured macrophages from patients with age-related macular degeneration.

Purpose: Oral vitamin and mineral supplements reduce the risk of visual loss in age-related macular degeneration (AMD). However, the pathways that mediate this beneficial effect are poorly understood. Macrophages may exert oxidative, inflammatory, and angiogenic effects in the context of AMD. We aim to assess if oral supplements can modulate the macrophage phenotype in this disease. Methods: Monocytes were isolated from patients with neovascular AMD (nvAMD), cultured, matured to macrophages, and polarized to classical [M1 (stimulated by IFNγ and lipopolysaccharide (LPS))] and alternative [M2 (stimulated with IL-4 and IL-13)] phenotypes. Combinations of antioxidants including lutein+zeaxanthin (1 µM; 0.2 µM), zinc (10 µM), carnosic acid (2 µM), beta-carotene (2 µM), and standardized tomato extract containing lycopene and other tomato phytonutrients were added to the culture media. Levels of anti-inflammatory, antioxidant, and pro-angiogenic gene and protein expression were then evaluated. Results: Combinations of lutein and carnosic acid with zinc and standardized tomato extract or with beta-carotene yielded an antioxidative, anti-inflammatory, and antiangiogenic effect in M1 and M2 macrophages. These effects manifested in the upregulation of antioxidative genes (HMOX1, SOD1) and the downregulation of pro-angiogenic genes and pro-inflammatory genes (SDF-1, TNF-alpha, IL-6, MCP-1). Lutein monotherapy or a combination of lutein and zinc had less effect on the expression of these genes. Conclusions: Combinations of supplements can modify the expression of genes and proteins that may be relevant for the involvement of macrophages in the pathogenesis of AMD. Further studies are required to evaluate if the modulation of the macrophage phenotype partially accounts for the beneficial effect of oral supplements in AMD and if modification of the AREDS formula can improve its effect on macrophages.

Plasma long-chain omega-3 polyunsaturated fatty acids and macular pigment in subjects with family history of age-related macular degeneration: the Limpia Study.

PURPOSE: In numerous epidemiological studies, omega-3 polyunsaturated fatty acids (PUFAs) have been associated with a decreased risk of age-related macular degeneration (AMD). Beyond their structural, functional and neuroprotective roles, omega-3 PUFAs may favour the retinal accumulation of lutein and zeaxanthin and thus increase macular pigment optical density (MPOD). We examined the associations of MPOD with plasma omega-3 PUFAs in subjects with family history of AMD. METHODS: The Limpia study is a double-blind, placebo-controlled, prospective randomized clinical trial performed in 120 subjects. Subjects with at least one parent treated for neovascular AMD, aged 40-70, with a best corrected visual acuity (BCVA) >20/25, free of late AMD and other major eye conditions and with no use of supplement containing lutein or zeaxanthin the preceding year were recruited in Bordeaux and Dijon, France. At baseline, MPOD within 1° of eccentricity was measured by modified Heidelberg retinal analyser (Heidelberg, Germany) and plasma omega-3 PUFAs by gas chromatography. Medical history and lifestyle data were collected from a standardized questionnaire. Associations of MPOD with plasma omega-3 PUFAs were assessed at the baseline examination, using mixed linear models adjusted for age, gender, centre, body mass index, smoking, plasma high-density lipoprotein (HDL) cholesterol and lutein+zeaxanthin. RESULTS: After multivariate adjustment, high MPOD was significantly associated with higher level of plasma docosapentaenoic acid (DPA) (ß = 0.029, 95% CI: 0.003, 0.055; p = 0.03). Plasma alpha linolenic, eicosapentaenoic and docosahexaenoic acids were not significantly associated with MPOD. CONCLUSION: In the Limpia study, high MPOD within 1° was significantly associated with higher plasma levels of omega-3 DPA.

Risk factors for exudative age-related macular degeneration in a large French case-control study.

PURPOSE: The purpose of the CAP (Creteil AMD PHRC-funded) Study was to analyze risk factors of exudative age-related macular degeneration (AMD) in a large French case-control population. PATIENTS AND METHODS: One thousand and twenty-four patients with exudative AMD and 275 controls were recruited. Information about lifestyle, medical history, and dietary intake were collected. Associations of risk factors were estimated using logistic regression. RESULTS: After multivariate adjustment, CFH Y402H and ARMS2 A69S polymorphisms were associated with very high risk for exudative AMD (OR = 6.21 and OR = 11.7, respectively, p < 0.0001). Risk for exudative AMD was increased in current smokers (OR = 3.79, p = 0.0003) and former smokers having quitted since less than 20 years ago (OR = 2.30, p = 0.002), but not in former smokers having quitted since 20 years or more ago (OR = 0.81, p = 0.43). Heavy smokers (at least 25 pack-years) were particularly at risk (OR = 3.61, p < 0.0001). Use of cooking oils rich in omega 3 fatty acids was significantly associated with a reduced risk of exudative AMD (OR = 0.55, 95 % CI: 0.36-0.84, p = 0.006), as well as a high consumption of fruits (OR = 0.60, 95 % CI: 0.37-0.98, p = 0.04), but not the consumption of fish, vegetables or oils rich in omega 6. High waist circumference was associated with increased risk for exudative AMD (OR = 2.53, p < 0.0001), but not hypercholesterolemia, hypertension, or body mass index. CONCLUSIONS: The CAP Study confirms major genetic risk factors for exudative AMD. It further documents the high risk in heavy smokers and the long persistence of risk after smoking cessation, and the associations with waist circumference and fruit consumption. Furthermore, we observed an inverse correlation between AMD and cooking oils harboring a beneficial omega-3 fatty acid profile.

Prospective study of common variants in CX3CR1 and risk of macular degeneration: pooled analysis from 5 long-term studies.

IMPORTANCE: The CX3CR1 gene is implicated as a candidate gene for age-related macular degeneration (AMD) through several lines of evidence. There is uncertainty, however, as to whether common genetic variants in CX3CR1 alter risk of AMD, since prior studies have been inconsistent and mostly limited to evaluation of 2 nonsynonymous variants, T280M (rs3732378) and V249I (rs3732379). OBJECTIVE: To determine if common variants in CX3CR1 predict future risk of AMD. DESIGN, SETTING, AND PARTICIPANTS: Prospective nested case-control study within 5 large study populations with long-term follow-up. We measured genotypes for T280M, V249I, and 13 other common single-nucleotide polymorphisms (SNPs) of the CX3CR1 gene among people who developed AMD (n = 1110, including 369 with neovascular AMD) and 2532 age- and sex-matched controls. MAIN OUTCOMES AND MEASURES: We determined the incidence rate ratios (RR) and 95% CIs for incidence of AMD for each variant and examined interactions with other AMD-associated variants and modifiable risk factors. RESULTS: In additive genetic models, we identified nonsignificant associations with AMD for T280M (RR, 0.87; P = .07) and 3 other SNPs, rs2853707 (RR, 0.88; P = .07), rs12636547 (RR, 0.85; P = .10), and rs1877563 (RR, 0.84; P = .06), 1 of which, rs2853707, is positioned in the CX3CR1 promoter region and was associated with neovascular AMD (RR, 0.75; P = .03). We observed that a recessive model was a better fit to the data for some SNPs, with associations between rs11715522 and AMD (RR, 1.27; P = .03) and between rs2669845 (RR, 3.10; P = .04), rs2853707 (RR, 0.48; P = .050), and rs9868689 (RR, 0.31; P = .02) and neovascular AMD. Moreover, in exploratory analyses, we identified a number of possible interactions including between V249I and rs2669845 and dietary intake of ω-3 fatty acids (P = .004 and P = .009, respectively) for AMD; between rs2669845 and obesity (P = .03) for neovascular AMD; between T280M and complement component 3 (C3) R102G for AMD (P = .03); between rs2669845 and Y402H in complement factor H for AMD (P = .04); and between rs2669845, rs2853707, and V249I and C3 R102G for neovascular AMD (P = .008; .04; and .002, respectively). CONCLUSIONS AND RELEVANCE: This study failed to identify significant associations between common CX3CR1 variants and AMD after considering the number of SNPs analyzed and multiple comparisons. However, we observed evidence consistent with recessive modes of association and that an effect of CX3CR1 variants may depend on other factors including dietary intake of ω-3 fatty acids, obesity, and genotypes at CFH Y402H and C3 R102G. If replicated in other populations, these findings would support a role for CX3CR1 in AMD but also suggest that its role may involve mechanisms that are independent of the T280M/V249I variations.