UMMS Affiliation

Department of Ophthalmology; Gene Therapy Center; Department of Microbiology and Physiological Systems

Date

3-29-2017

Document Type

Article

Disciplines

Cellular and Molecular Physiology | Eye Diseases | Molecular Biology | Ophthalmology

Abstract

The accumulation of lipofuscin in the retinal pigment epithelium (RPE) is dependent on the effectiveness of photoreceptor outer segment material degradation. This study explored the role of autophagy in the fate of RPE lipofuscin degradation. After seven days of feeding with either native or modified rod outer segments, ARPE-19 cells were treated with enhancers or inhibitors of autophagy and the autofluorescence was detected by fluorescence-activated cell sorting. Supplementation with different types of rod outer segments increased lipofuscin-like autofluorescence (LLAF) after the inhibition of autophagy, while the induction of autophagy (e.g., application of rapamycin) decreased LLAF. The effects of autophagy induction were further confirmed by Western blotting, which showed the conversion of LC3-I to LC3-II, and by immunofluorescence microscopy, which detected the lysosomal activity of the autophagy inducers. We also monitored LLAF after the application of several autophagy inhibitors by RNA-interference and confocal microscopy. The results showed that, in general, the inhibition of the autophagy-related proteins resulted in an increase in LLAF when cells were fed with rod outer segments, which further confirms the effect of autophagy in the fate of RPE lipofuscin degradation. These results emphasize the complex role of autophagy in modulating RPE autofluorescence and confirm the possibility of the pharmacological clearance of RPE lipofuscin by small molecules.

Rights and Permissions

Copyright © 2017 by the authors.

DOI of Published Version

10.3390/ijms18040728

Source

Int J Mol Sci. 2017 Mar 29;18(4). pii: E728. doi: 10.3390/ijms18040728. Link to article on publisher's site

Related Resources

Link to Article in PubMed

Keywords

age-related macular degeneration, autofluorescence, autophagy, degradation, lipofuscin, mTOR, retinal pigment epithelium

Journal Title

International journal of molecular sciences

PubMed ID

28353645

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

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