9
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Evaluation of an oral telomerase activator for early age-related macular degeneration - a pilot study

      research-article

      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

          Purpose

          Telomere attrition and corresponding cellular senescence of the retinal pigment epithelium contribute to the changes of age-related macular degeneration. Activation of the enzyme telomerase can add telomeric DNA to retinal pigment epithelium chromosomal ends and has been proposed as a treatment for age-related macular degeneration. We report the use of a small molecule, oral telomerase activator (TA)-65 in early macular degeneration. This study, focusing on early macular degeneration, provides a model for the use of TAs in age-related disease.

          Method

          Thirty-eight (38) patients were randomly assigned to a 1-year, double-blinded, placebo-controlled interventional study with arms for oral TA-65 or placebo. Macular functions via micro-perimetry were the primary measured outcomes.

          Results

          The macular function in the arm receiving the TA-65 showed significant improvement relative to the placebo control. The improvement was manifest at 6 months and was maintained at 1 year: macular threshold sensitivity (measured as average dB [logarithmic decibel scale of light attenuation]) improved 0.97 dB compared to placebo ( P-value 0.02) and percent reduced thresholds lessened 8.2% compared to the placebo arm ( P-value 0.04).

          Conclusion

          The oral TA significantly improved the macular function of treatment subjects compared to controls. Although this study was a pilot and a larger study is being planned, it is noteworthy in that it is, to our knowledge, the first randomized placebo-controlled study of a TA supplement.

          Related collections

          Most cited references41

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

          Extension of life-span by introduction of telomerase into normal human cells.

          Normal human cells undergo a finite number of cell divisions and ultimately enter a nondividing state called replicative senescence. It has been proposed that telomere shortening is the molecular clock that triggers senescence. To test this hypothesis, two telomerase-negative normal human cell types, retinal pigment epithelial cells and foreskin fibroblasts, were transfected with vectors encoding the human telomerase catalytic subunit. In contrast to telomerase-negative control clones, which exhibited telomere shortening and senescence, telomerase-expressing clones had elongated telomeres, divided vigorously, and showed reduced straining for beta-galactosidase, a biomarker for senescence. Notably, the telomerase-expressing clones have a normal karyotype and have already exceeded their normal life-span by at least 20 doublings, thus establishing a causal relationship between telomere shortening and in vitro cellular senescence. The ability to maintain normal human cells in a phenotypically youthful state could have important applications in research and medicine.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Prevalence of age-related macular degeneration in the United States.

            To estimate the prevalence and distribution of age-related macular degeneration (AMD) in the United States by age, race/ethnicity, and gender. Summary prevalence estimates of drusen 125 microm or larger, neovascular AMD, and geographic atrophy were prepared separately for black and white persons in 5-year age intervals starting at 40 years. The estimated rates were based on a meta-analysis of recent population-based studies in the United States, Australia, and Europe. These rates were applied to 2000 US Census data and to projected US population figures for 2020 to estimate the number of the US population with drusen and AMD. The overall prevalence of neovascular AMD and/or geographic atrophy in the US population 40 years and older is estimated to be 1.47% (95% confidence interval, 1.38%-1.55%), with 1.75 million citizens having AMD. The prevalence of AMD increased dramatically with age, with more than 15% of the white women older than 80 years having neovascular AMD and/or geographic atrophy. More than 7 million individuals had drusen measuring 125 microm or larger and were, therefore, at substantial risk of developing AMD. Owing to the rapidly aging population, the number of persons having AMD will increase by 50% to 2.95 million in 2020. Age-related macular degeneration was far more prevalent among white than among black persons. Age-related macular degeneration affects more than 1.75 million individuals in the United States. Owing to the rapid aging of the US population, this number will increase to almost 3 million by 2020.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Telomerase mutations in families with idiopathic pulmonary fibrosis.

              Idiopathic pulmonary fibrosis is progressive and often fatal; causes of familial clustering of the disease are unknown. Germ-line mutations in the genes hTERT and hTR, encoding telomerase reverse transcriptase and telomerase RNA, respectively, cause autosomal dominant dyskeratosis congenita, a rare hereditary disorder associated with premature death from aplastic anemia and pulmonary fibrosis. To test the hypothesis that familial idiopathic pulmonary fibrosis may be caused by short telomeres, we screened 73 probands from the Vanderbilt Familial Pulmonary Fibrosis Registry for mutations in hTERT and hTR. Six probands (8%) had heterozygous mutations in hTERT or hTR; mutant telomerase resulted in short telomeres. Asymptomatic subjects with mutant telomerase also had short telomeres, suggesting that they may be at risk for the disease. We did not identify any of the classic features of dyskeratosis congenita in five of the six families. Mutations in the genes encoding telomerase components can appear as familial idiopathic pulmonary fibrosis. Our findings support the idea that pathways leading to telomere shortening are involved in the pathogenesis of this disease. Copyright 2007 Massachusetts Medical Society.
                Bookmark

                Author and article information

                Journal
                Clin Ophthalmol
                Clin Ophthalmol
                Clinical Ophthalmology
                Clinical Ophthalmology (Auckland, N.Z.)
                Dove Medical Press
                1177-5467
                1177-5483
                2016
                28 January 2016
                : 10
                : 243-249
                Affiliations
                [1 ]McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, USA
                [2 ]Chippewa Valley Eye Clinic, Eau Claire, Wisconsin, WI, USA
                [3 ]Independent Telomere Biology Consultant, Murphys, CA, USA
                Author notes
                Correspondence: Coad Thomas Dow, Chippewa Valley Eye Clinic, 2715 Damon Street, Eau Claire, Wisconsin, WI, USA, Tel +1 715 834 8471, Fax +1 715 834 0373, Email ctdow@ 123456me.com
                Article
                opth-10-243
                10.2147/OPTH.S100042
                4734847
                26869760
                10a9797c-9457-4d4e-9091-14089af08ad0
                © 2016 Dow and Harley. This work is published and licensed by Dove Medical Press Limited

                The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution – Non Commercial (unported, v3.0) License ( http://creativecommons.org/licenses/by-nc/3.0/). By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed.

                History
                Categories
                Clinical Trial Report

                Ophthalmology & Optometry
                drusen,macular degeneration,micro-perimetry,senescence,telomerase activation,telomere

                Comments

                Comment on this article