| The phototoxicity of aged human retinal melanosomes. | |
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MedLine Citation:
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PMID: 18086241 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The purpose of this study was to determine whether an age-related increase in photoreactivity of human retinal melanosomes (MS) can cause phototoxicity to retinal pigment epithelium (RPE) cells. MS were isolated post mortem from young (20-30 years, young human melanosomes [YHMs]) and old (60-90 years, old human melanosomes [OHMs]) human eyes and from young bovine eyes (bovine melanosomes [BMs]). Confluent cultured ARPE-19 cells were fed equivalent numbers of OHMs or BMs and accumulated similar amounts of melanin as determined by electron paramagnetic resonance assay. Cells with and without MS were either maintained in the dark or exposed to blue light for up to 96 h and assessed for alterations in cell morphology, cell viability and lysosomal integrity. Incubation of cells in dark in the presence of internalized MS or irradiation of cells with blue light in the absence or presence of BMs did not significantly affect cell viability. However, exposures to blue light in the presence of OHMs resulted in abnormal cell morphology, up to approximately 75% decrease in mitochondrial activity, loss of lysosomal pH and cell death. OHMs contained significantly less melanin than YHMs, supporting the hypothesis that melanin undergoes degradation during RPE aging. Our results demonstrate that aged MS can be phototoxic to human RPE cells and support a contributing role of MS in RPE aging and in the pathogenesis of age-related macular degeneration. |
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Authors:
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Bartosz Rózanowski; Joyceline Cuenco; Sallyanne Davies; Farukh A Shamsi; Andrzej Zadło; Pierrette Dayhaw-Barker; Małgorzata Rózanowska; Tadeusz Sarna; Michael E Boulton |
Publication Detail:
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Type: Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't Date: 2007-12-17 |
Journal Detail:
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Title: Photochemistry and photobiology Volume: 84 ISSN: 0031-8655 ISO Abbreviation: Photochem. Photobiol. Publication Date: 2008 May-Jun |
Date Detail:
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Created Date: 2008-04-25 Completed Date: 2008-09-11 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 0376425 Medline TA: Photochem Photobiol Country: United States |
Other Details:
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Languages: eng Pagination: 650-7 Citation Subset: IM |
Affiliation:
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School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adult Age Factors Aged Aged, 80 and over Animals Cattle Cell Survival / radiation effects Cells, Cultured Free Radicals / metabolism Humans Hydrogen-Ion Concentration Light* Lysosomes / metabolism Melanosomes / metabolism, radiation effects* Middle Aged Pigment Epithelium of Eye / cytology, metabolism*, radiation effects* |
| Grant Support | |
ID/Acronym/Agency:
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R01 EY013722/EY/NEI NIH HHS; //Wellcome Trust |
| Chemical | |
Reg. No./Substance:
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0/Free Radicals |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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