Inhibition of autophagy induces retinal pigment epithelial cell damage by the lipofuscin fluorophore A2E
In this study, we show augmented autophagy in the retinal pigment epithelial cell line ARPE-19 when cultured in the presence of the lipofuscin pigment A2E. A2E alone does not induce RPE cell death, but cell death was induced in the presence of A2E with the autophagy inhibitor 3-methyladenine (3MA),...
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| Format: | Article |
| Language: | English |
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Wiley
2014-01-01
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| Series: | FEBS Open Bio |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2211546314001090 |
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| author | Khandakar A.S.M. Saadat Yusuke Murakami Xue Tan Yoko Nomura Tsutomu Yasukawa Eiichi Okada Yasuhiro Ikeda Yasuo Yanagi |
| author_facet | Khandakar A.S.M. Saadat Yusuke Murakami Xue Tan Yoko Nomura Tsutomu Yasukawa Eiichi Okada Yasuhiro Ikeda Yasuo Yanagi |
| author_sort | Khandakar A.S.M. Saadat |
| collection | DOAJ |
| description | In this study, we show augmented autophagy in the retinal pigment epithelial cell line ARPE-19 when cultured in the presence of the lipofuscin pigment A2E. A2E alone does not induce RPE cell death, but cell death was induced in the presence of A2E with the autophagy inhibitor 3-methyladenine (3MA), with a concomitant increase in the generation of mitochondrial reactive oxygen species. On the other hand, the ATP production capacity of mitochondria was decreased in the presence of A2E, and pharmacological inhibition of autophagy had no additional effects. The altered mRNA expression level of mitochondrial function markers was confirmed by real-time polymerase chain reaction, which showed that the antioxidant enzymes SOD1 and SOD2 were not reduced in the presence of A2E alone, but significantly suppressed with the addition of 3MA. Furthermore, transmission electron micrography revealed autophagic vacuole formation in the presence of A2E, and inhibition of autophagy resulted in the accumulation of abnormal mitochondria with loss of cristae. Spheroid culture of human RPE cells demonstrated debris accumulation in the presence of A2E, and this accumulation was accelerated in the presence of 3MA. These results indicate that autophagy in RPE cells is a vital cytoprotective process that prevents the accumulation of damaged cellular molecules. |
| first_indexed | 2024-12-23T20:37:59Z |
| format | Article |
| id | doaj.art-45cf403767784a70bbb609c546a73954 |
| institution | Directory Open Access Journal |
| issn | 2211-5463 |
| language | English |
| last_indexed | 2024-12-23T20:37:59Z |
| publishDate | 2014-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | FEBS Open Bio |
| spelling | doaj.art-45cf403767784a70bbb609c546a739542022-12-21T17:32:00ZengWileyFEBS Open Bio2211-54632014-01-014C1007101410.1016/j.fob.2014.11.003Inhibition of autophagy induces retinal pigment epithelial cell damage by the lipofuscin fluorophore A2EKhandakar A.S.M. Saadat0Yusuke Murakami1Xue Tan2Yoko Nomura3Tsutomu Yasukawa4Eiichi Okada5Yasuhiro Ikeda6Yasuo Yanagi7Department of Ophthalmology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, JapanDepartment of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, JapanDepartment of Ophthalmology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, JapanDepartment of Ophthalmology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, JapanDepartment of Ophthalmology and Visual Science, Nagoya City University Graduate School of Medical Sciences, Aichi 467-8601, JapanOkada Eye Clinic, Kanagawa 234-0054, JapanDepartment of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, JapanDepartment of Ophthalmology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, JapanIn this study, we show augmented autophagy in the retinal pigment epithelial cell line ARPE-19 when cultured in the presence of the lipofuscin pigment A2E. A2E alone does not induce RPE cell death, but cell death was induced in the presence of A2E with the autophagy inhibitor 3-methyladenine (3MA), with a concomitant increase in the generation of mitochondrial reactive oxygen species. On the other hand, the ATP production capacity of mitochondria was decreased in the presence of A2E, and pharmacological inhibition of autophagy had no additional effects. The altered mRNA expression level of mitochondrial function markers was confirmed by real-time polymerase chain reaction, which showed that the antioxidant enzymes SOD1 and SOD2 were not reduced in the presence of A2E alone, but significantly suppressed with the addition of 3MA. Furthermore, transmission electron micrography revealed autophagic vacuole formation in the presence of A2E, and inhibition of autophagy resulted in the accumulation of abnormal mitochondria with loss of cristae. Spheroid culture of human RPE cells demonstrated debris accumulation in the presence of A2E, and this accumulation was accelerated in the presence of 3MA. These results indicate that autophagy in RPE cells is a vital cytoprotective process that prevents the accumulation of damaged cellular molecules.http://www.sciencedirect.com/science/article/pii/S2211546314001090AutophagyRetinal pigment epitheliumLipofuscinMitochondriaReactive oxygen species |
| spellingShingle | Khandakar A.S.M. Saadat Yusuke Murakami Xue Tan Yoko Nomura Tsutomu Yasukawa Eiichi Okada Yasuhiro Ikeda Yasuo Yanagi Inhibition of autophagy induces retinal pigment epithelial cell damage by the lipofuscin fluorophore A2E FEBS Open Bio Autophagy Retinal pigment epithelium Lipofuscin Mitochondria Reactive oxygen species |
| title | Inhibition of autophagy induces retinal pigment epithelial cell damage by the lipofuscin fluorophore A2E |
| title_full | Inhibition of autophagy induces retinal pigment epithelial cell damage by the lipofuscin fluorophore A2E |
| title_fullStr | Inhibition of autophagy induces retinal pigment epithelial cell damage by the lipofuscin fluorophore A2E |
| title_full_unstemmed | Inhibition of autophagy induces retinal pigment epithelial cell damage by the lipofuscin fluorophore A2E |
| title_short | Inhibition of autophagy induces retinal pigment epithelial cell damage by the lipofuscin fluorophore A2E |
| title_sort | inhibition of autophagy induces retinal pigment epithelial cell damage by the lipofuscin fluorophore a2e |
| topic | Autophagy Retinal pigment epithelium Lipofuscin Mitochondria Reactive oxygen species |
| url | http://www.sciencedirect.com/science/article/pii/S2211546314001090 |
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