Cargando…
Products of Docosahexaenoate Oxidation as Contributors to Photosensitising Properties of Retinal Lipofuscin
Retinal lipofuscin which accumulates with age in the retinal pigment epithelium (RPE) is subjected to daily exposures to high fluxes of visible light and exhibits potent photosensitising properties; however, the molecules responsible for its photoreactivity remain unknown. Here, we demonstrate that...
Autores principales: | , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2021
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8037991/ https://www.ncbi.nlm.nih.gov/pubmed/33805370 http://dx.doi.org/10.3390/ijms22073525 |
_version_ | 1783677271839604736 |
---|---|
author | Różanowska, Małgorzata B. Pawlak, Anna Różanowski, Bartosz |
author_facet | Różanowska, Małgorzata B. Pawlak, Anna Różanowski, Bartosz |
author_sort | Różanowska, Małgorzata B. |
collection | PubMed |
description | Retinal lipofuscin which accumulates with age in the retinal pigment epithelium (RPE) is subjected to daily exposures to high fluxes of visible light and exhibits potent photosensitising properties; however, the molecules responsible for its photoreactivity remain unknown. Here, we demonstrate that autooxidation of docosahexaenoate (DHE) leads to the formation of products absorbing, in addition to UVB and UVA light, also visible light. The products of DHE oxidation exhibit potent photosensitising properties similar to photosensitising properties of lipofuscin, including generation of an excited triplet state with similar characteristics as the lipofuscin triplet state, and photosensitised formation of singlet oxygen and superoxide. The quantum yields of singlet oxygen and superoxide generation by oxidised DHE photoexcited with visible light are 2.4- and 3.6-fold higher, respectively, than for lipofuscin, which is consistent with the fact that lipofuscin contains some chromophores which do contribute to the absorption of light but not so much to its photosensitising properties. Importantly, the wavelength dependence of photooxidation induced by DHE oxidation products normalised to equal numbers of incident photons is also similar to that of lipofuscin—it steeply increases with decreasing wavelength. Altogether, our results demonstrate that products of DHE oxidation include potent photosensitiser(s) which are likely to contribute to lipofuscin photoreactivity. |
format | Online Article Text |
id | pubmed-8037991 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-80379912021-04-12 Products of Docosahexaenoate Oxidation as Contributors to Photosensitising Properties of Retinal Lipofuscin Różanowska, Małgorzata B. Pawlak, Anna Różanowski, Bartosz Int J Mol Sci Article Retinal lipofuscin which accumulates with age in the retinal pigment epithelium (RPE) is subjected to daily exposures to high fluxes of visible light and exhibits potent photosensitising properties; however, the molecules responsible for its photoreactivity remain unknown. Here, we demonstrate that autooxidation of docosahexaenoate (DHE) leads to the formation of products absorbing, in addition to UVB and UVA light, also visible light. The products of DHE oxidation exhibit potent photosensitising properties similar to photosensitising properties of lipofuscin, including generation of an excited triplet state with similar characteristics as the lipofuscin triplet state, and photosensitised formation of singlet oxygen and superoxide. The quantum yields of singlet oxygen and superoxide generation by oxidised DHE photoexcited with visible light are 2.4- and 3.6-fold higher, respectively, than for lipofuscin, which is consistent with the fact that lipofuscin contains some chromophores which do contribute to the absorption of light but not so much to its photosensitising properties. Importantly, the wavelength dependence of photooxidation induced by DHE oxidation products normalised to equal numbers of incident photons is also similar to that of lipofuscin—it steeply increases with decreasing wavelength. Altogether, our results demonstrate that products of DHE oxidation include potent photosensitiser(s) which are likely to contribute to lipofuscin photoreactivity. MDPI 2021-03-29 /pmc/articles/PMC8037991/ /pubmed/33805370 http://dx.doi.org/10.3390/ijms22073525 Text en © 2021 by the authors. https://creativecommons.org/licenses/by/4.0/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/ (https://creativecommons.org/licenses/by/4.0/) ). |
spellingShingle | Article Różanowska, Małgorzata B. Pawlak, Anna Różanowski, Bartosz Products of Docosahexaenoate Oxidation as Contributors to Photosensitising Properties of Retinal Lipofuscin |
title | Products of Docosahexaenoate Oxidation as Contributors to Photosensitising Properties of Retinal Lipofuscin |
title_full | Products of Docosahexaenoate Oxidation as Contributors to Photosensitising Properties of Retinal Lipofuscin |
title_fullStr | Products of Docosahexaenoate Oxidation as Contributors to Photosensitising Properties of Retinal Lipofuscin |
title_full_unstemmed | Products of Docosahexaenoate Oxidation as Contributors to Photosensitising Properties of Retinal Lipofuscin |
title_short | Products of Docosahexaenoate Oxidation as Contributors to Photosensitising Properties of Retinal Lipofuscin |
title_sort | products of docosahexaenoate oxidation as contributors to photosensitising properties of retinal lipofuscin |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8037991/ https://www.ncbi.nlm.nih.gov/pubmed/33805370 http://dx.doi.org/10.3390/ijms22073525 |
work_keys_str_mv | AT rozanowskamałgorzatab productsofdocosahexaenoateoxidationascontributorstophotosensitisingpropertiesofretinallipofuscin AT pawlakanna productsofdocosahexaenoateoxidationascontributorstophotosensitisingpropertiesofretinallipofuscin AT rozanowskibartosz productsofdocosahexaenoateoxidationascontributorstophotosensitisingpropertiesofretinallipofuscin |