PUBLICATION
Transient acceleration of autophagic degradation by pharmacological Nrf2 activation is important for retinal pigment epithelium cell survival
- Authors
- Saito, Y., Kuse, Y., Inoue, Y., Nakamura, S., Hara, H., Shimazawa, M.
- ID
- ZDB-PUB-180915-7
- Date
- 2018
- Source
- Redox Biology 19: 354-363 (Journal)
- Registered Authors
- Keywords
- Autophagy, NF-E2-related factor 2, Non-exudative age-related macular degeneration, Retinal pigment epithelium, Sequestosome 1
- MeSH Terms
-
- Animals
- Antioxidants/pharmacology*
- Autophagy/drug effects*
- Cell Line
- Cell Survival/drug effects*
- Cytoprotection/drug effects
- Humans
- NF-E2-Related Factor 2/agonists*
- NF-E2-Related Factor 2/metabolism
- Oxidative Stress/drug effects*
- Retinal Pigment Epithelium/cytology
- Retinal Pigment Epithelium/drug effects*
- Signal Transduction/drug effects
- Triterpenes/pharmacology*
- Zebrafish
- PubMed
- 30216854 Full text @ Redox Biol.
Citation
Saito, Y., Kuse, Y., Inoue, Y., Nakamura, S., Hara, H., Shimazawa, M. (2018) Transient acceleration of autophagic degradation by pharmacological Nrf2 activation is important for retinal pigment epithelium cell survival. Redox Biology. 19:354-363.
Abstract
Non-exudative age-related macular degeneration (AMD) is mainly caused by the accumulation of lipofuscin and drusen on the retinal pigment epithelium (RPE). Both oxidative stress and autophagic dysfunction accelerate the deposition of lipofuscin at the RPE. One of the key regulators in the response against oxidative stress is the NF-E2-Related Factor 2 (Nrf2)-kelch like ECH associated protein 1 (Keap1) axis, which is also closely associated with the autophagy pathway. Nrf2 activation upregulates the expression levels of certain anti-oxidative enzymes [e.g. Heme oxygenase-1 (HO-1)], which attenuates oxidative damage. However, until now, the relationship between cytoprotective effects of Nrf2 activation and autophagic degradation remain unclear. To address these questions, we investigated the effects of a novel Nrf2 activator, RS9, on RPE damage. We found that RS9 protected ARPE-19 cells against NaIO3-induced oxidative damage, and that the protective effects of RS9 were inhibited by co-treatment with zinc protoporphyrin, an HO-1 inhibitor. Next, we examined the involvement of autophagic degradation in the protective effects of RS9. Co-treatment with RS9 and chloroquine, a lysosomal acidification inhibitor, inhibited the protective effect. Furthermore, western blotting and immunostaining showed that RS9 accelerated autophagy flux and induced transient upregulation of p62 [also known as sequestosome 1 (SQSTM1)]. Co-treatment with chloroquine and RS9 also inhibited the degradation of autophagosomes. Transient upregulation of SQSTM1 by RS9 was unaltered by HO-1 knockdown using siRNA. RS9 and chloroquine had the same actions in light damaged adult zebrafish retina as those in vitro. In conclusion, we clarified the relationship between acceleration of the autophagy pathway and the cytoprotective effects of Nrf2 activation in RPE cells and zebrafish retina. These findings indicated that Nrf2 activation could be a promising therapeutic approach for non-exudative AMD by supporting RPE maintenance.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping