Association of Dietary and Supplementary Calcium Intake With Age-Related Macular Degeneration: Age-Related Eye Disease Study Report 39.

Importance: Previous studies of the role of dietary and supplementary calcium in age-related macular degeneration (AMD) have produced mixed results, suggesting that supplementation and decreased dietary intake are both harmful. Objective: To evaluate the association of baseline dietary and supplementary calcium intake with progression of AMD. Design, Setting, and Participants: This study involved secondary analyses of participants enrolled in the Age-Related Eye Disease Study (AREDS). The AREDS study (1992-2001) enrolled patients from academic and community-based retinal practices in the United States. Men and women with varying severity of AMD were included. Data analysis for this article occurred from September 2015 to December 2018. Exposures: Baseline self-reported dietary or supplementary calcium intake. Main Outcomes and Measures: Development of late AMD, geographic atrophy (central or noncentral), or neovascular AMD detected on centrally graded baseline and annual fundus photographs. Results: A total of 4751 participants were included (mean [SD] age, 69.4 [5.1] years); 4543 (95.6%) were white, and 2655 (55.9%) were female. Compared with those who were in the lowest quintile, the participants in the highest quintile of dietary calcium intake had a lower risk of developing late AMD (hazard ratio [HR], 0.73 [95% CI, 0.59-0.90]), central geographic atrophy (HR, 0.64 [95% CI, 0.48-0.86]), and any geographic atrophy (HR, 0.80 [95% CI, 0.64-1.00]). The participants in the highest tertile of supplementary calcium intake had a lower risk of developing neovascular AMD (HR, 0.70 [95% CI, 0.50-0.97]) compared with those who did not take calcium supplements. When stratified by sex, women in the highest quintile of dietary calcium intake had a lower risk of developing late AMD (HR, 0.73 [95% CI, 0.56-0.97]) compared with those in the lowest quintile. Women in the highest tertile of calcium supplementation had a lower risk of progression to neovascular AMD (HR, 0.67 [95% CI, 0.48-0.94]) compared with those who did not take calcium supplements. Similar findings were found in men for dietary calcium. Too few men took calcium supplements to allow for analyses. Conclusions and Relevance: In this secondary analysis, higher levels of dietary and supplementary calcium intake were associated with lower incidence of progression to late AMD in AREDS participants. The results may be owing to uncontrolled confounding or chance and should be considered hypothesis development requiring additional study.

Endostatin lowers blood pressure via nitric oxide and prevents hypertension associated with VEGF inhibition.

Antiangiogenesis therapy has become a vital part of the armamentarium against cancer. Hypertension is a dose-limiting toxicity for VEGF inhibitors. Thus, there is a pressing need to address the associated adverse events so these agents can be better used. The hypertension may be mediated by reduced NO bioavailability resulting from VEGF inhibition. We proposed that the hypertension may be prevented by coadministration with endostatin (ES), an endogenous angiogenesis inhibitor with antitumor effects shown to increase endothelial NO production in vitro. We determined that Fc-conjugated ES promoted NO production in endothelial and smooth muscle cells. ES also lowered blood pressure in normotensive mice and prevented hypertension induced by anti-VEGF antibodies. This effect was associated with higher circulating nitrate levels and was absent in eNOS-knockout mice, implicating a NO-mediated mechanism. Retrospective study of patients treated with ES in a clinical trial revealed a small but significant reduction in blood pressure, suggesting that the findings may translate to the clinic. Coadministration of ES with VEGF inhibitors may offer a unique strategy to prevent drug-related hypertension and enhance antiangiogenic tumor suppression.

Poly(ß-amino ester)-nanoparticle mediated transfection of retinal pigment epithelial cells in vitro and in vivo.

A variety of genetic diseases in the retina, including retinitis pigmentosa and leber congenital amaurosis, might be excellent targets for gene delivery as treatment. A major challenge in non-viral gene delivery remains finding a safe and effective delivery system. Poly(beta-amino ester)s (PBAEs) have shown great potential as gene delivery reagents because they are easily synthesized and they transfect a wide variety of cell types with high efficacy in vitro. We synthesized a combinatorial library of PBAEs and evaluated them for transfection efficacy and toxicity in retinal pigment epithelial (ARPE-19) cells to identify lead polymer structures and transfection formulations. Our optimal polymer (B5-S5-E7 at 60 w/w polymer:DNA ratio) transfected ARPE-19 cells with 44±5% transfection efficacy, significantly higher than with optimized formulations of leading commercially available reagents Lipofectamine 2000 (26±7%) and X-tremeGENE HP DNA (22±6%); (p<0.001 for both). Ten formulations exceeded 30% transfection efficacy. This high non-viral efficacy was achieved with comparable cytotoxicity (23±6%) to controls; optimized formulations of Lipofectamine 2000 and X-tremeGENE HP DNA showed 15±3% and 32±9% toxicity respectively (p>0.05 for both). Our optimal polymer was also significantly better than a gold standard polymeric transfection reagent, branched 25 kDa polyethyleneimine (PEI), which achieved only 8±1% transfection efficacy with 25±6% cytotoxicity. Subretinal injections using lyophilized GFP-PBAE nanoparticles resulted in 1.1±1×10(3)-fold and 1.5±0.7×10(3)-fold increased GFP expression in the retinal pigment epithelium (RPE)/choroid and neural retina respectively, compared to injection of DNA alone (p = 0.003 for RPE/choroid, p<0.001 for neural retina). The successful transfection of the RPE in vivo suggests that these nanoparticles could be used to study a number of genetic diseases in the laboratory with the potential to treat debilitating eye diseases.