12
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Potential Treatment of Retinal Diseases with Iron Chelators

      review-article
      1 , 2 , 1 , *
      Pharmaceuticals
      MDPI
      chelation, iron, retina, age-related macular degeneration (AMD)

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Iron is essential for life, while excess iron can be toxic. Iron generates hydroxyl radical, which is the most reactive free radical, causing oxidative stress. Since iron is absorbed through the diet but not excreted from the body, it accumulates with age in tissues, including the retina, consequently leading to age-related toxicity. This accumulation is further promoted by inflammation. Hereditary diseases such as aceruloplasminemia, Friedreich’s ataxia, pantothenate kinase-associated neurodegeneration, and posterior column ataxia with retinitis pigmentosa involve retinal degeneration associated with iron dysregulation. In addition to hereditary causes, dietary or parenteral iron supplementation has been recently reported to elevate iron levels in the retinal pigment epithelium (RPE) and promote retinal degeneration. Ocular siderosis from intraocular foreign bodies or subretinal hemorrhage can also lead to retinopathy. Evidence from mice and humans suggests that iron toxicity may contribute to age-related macular degeneration pathogenesis. Iron chelators can protect photoreceptors and RPE in various mouse models. The therapeutic potential for iron chelators is under investigation.

          Related collections

          Most cited references84

          • Record: found
          • Abstract: found
          • Article: not found

          Age-related macular degeneration.

          Age-related macular degeneration is the leading cause of blindness in elderly populations of European descent. The most consistent risk factors associated with this ocular condition are increasing age and cigarette smoking. Genetic investigations have shown that complement factor H, a regulator of the alternative complement pathway, and LOC387715/HtrA1 are the most consistent genetic risk factors for age-related macular degeneration. Although the pathogenesis of this disease is unknown, oxidative stress might have an important role. Treatment with antioxidant vitamins and zinc can reduce the risk of developing advanced age-related macular degeneration by about a quarter in those at least at moderate risk. Intravitreal injections of ranibizumab, a monoclonal antibody that inhibits all forms of vascular endothelial growth factor, have been shown to stabilise loss of vision and, in some cases, improve vision in individuals with neovascular age-related macular degeneration. These findings, combined with assessments of possible environmental and genetic interactions and new approaches to modulate inflammatory pathways, will hopefully further expand our ability to understand and treat age-related macular degeneration.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Regulation of iron metabolism by hepcidin.

            Hepcidin, a peptide hormone made in the liver, is the principal regulator of systemic iron homeostasis. Hepcidin controls plasma iron concentration and tissue distribution of iron by inhibiting intestinal iron absorption, iron recycling by macrophages, and iron mobilization from hepatic stores. Hepcidin acts by inhibiting cellular iron efflux through binding to and inducing the degradation of ferroportin, the sole known cellular iron exporter. Synthesis of hepcidin is homeostatically increased by iron loading and decreased by anemia and hypoxia. Hepcidin is also elevated during infections and inflammation, causing a decrease in serum iron levels and contributing to the development of anemia of inflammation, probably as a host defense mechanism to limit the availability of iron to invading microorganisms. At the opposite side of the spectrum, hepcidin deficiency appears to be the ultimate cause of most forms of hemochromatosis, either due to mutations in the hepcidin gene itself or due to mutations in the regulators of hepcidin synthesis. The emergence of hepcidin as the pathogenic factor in most systemic iron disorders should provide important opportunities for improving their diagnosis and treatment.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Long-term effects of vitamins C and E, β-carotene, and zinc on age-related macular degeneration: AREDS report no. 35.

              To describe the long-term effects (10 years) of the Age-Related Eye Disease Study (AREDS) formulation of high-dose antioxidants and zinc supplement on progression of age-related macular degeneration (AMD). Multicenter, randomized, controlled, clinical trial followed by an epidemiologic follow-up study. We enrolled 4757 participants with varying severity of AMD in the clinical trial; 3549 surviving participants consented to the follow-up study. Participants were randomly assigned to antioxidants C, E, and β-carotene and/or zinc versus placebo during the clinical trial. For participants with intermediate or advanced AMD in 1 eye, the AREDS formulation delayed the progression to advanced AMD. Participants were then enrolled in a follow-up study. Eye examinations were conducted with annual fundus photographs and best-corrected visual acuity assessments. Medical histories and mortality were obtained for safety monitoring. Repeated measures logistic regression was used in the primary analyses. Photographic assessment of progression to, or history of treatment for, advanced AMD (neovascular [NV] or central geographic atrophy [CGA]), and moderate visual acuity loss from baseline (≥15 letters). Comparison of the participants originally assigned to placebo in AREDS categories 3 and 4 at baseline with those originally assigned to AREDS formulation at 10 years demonstrated a significant (P<0.001) odds reduction in the risk of developing advanced AMD or the development of NV AMD (odds ratio [OR], 0.66, 95% confidence interval [CI], 0.53-0.83 and OR, 0.60; 95% CI, 0.47-0. 78, respectively). No significant reduction (P = 0.93) was seen for the CGA (OR, 1.02; 95% CI, 0.71-1.45). A significant reduction (P = 0.002) for the development of moderate vision loss was seen (OR 0.71; 95% CI, 0.57-0.88). No adverse effects were associated with the AREDS formulation. Mortality was reduced in participants assigned to zinc, especially death from circulatory diseases. Five years after the clinical trial ended, the beneficial effects of the AREDS formulation persisted for development of NV AMD but not for CGA. These results are consistent with the original recommendations that persons with intermediate or advanced AMD in 1 eye should consider taking the AREDS formulation. The authors have no proprietary or commercial interest in any of the materials discussed in this article. Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.
                Bookmark

                Author and article information

                Journal
                Pharmaceuticals (Basel)
                Pharmaceuticals (Basel)
                pharmaceuticals
                Pharmaceuticals
                MDPI
                1424-8247
                22 October 2018
                December 2018
                : 11
                : 4
                : 112
                Affiliations
                [1 ]F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, 305 Stellar-Chance Laboratory, Philadelphia, PA 19104, USA; shuwanting@ 123456sjtu.edu.cn
                [2 ]Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai 200080, China
                Author notes
                [* ]Correspondence: jdunaief@ 123456pennmedicine.upenn.edu ; Tel.: +1-215-898-5235
                Article
                pharmaceuticals-11-00112
                10.3390/ph11040112
                6316536
                30360383
                caf33281-e8cb-4597-914e-4db908bbbf79
                © 2018 by the authors.

                Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ( http://creativecommons.org/licenses/by/4.0/).

                History
                : 01 September 2018
                : 10 October 2018
                Categories
                Review

                chelation,iron,retina,age-related macular degeneration (amd)

                Comments

                Comment on this article