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Dysregulated autophagy in the RPE is associated with increased susceptibility to oxidative stress and AMD.
Autophagy. 2014; 10(11):1989-2005.A

Abstract

Autophagic dysregulation has been suggested in a broad range of neurodegenerative diseases including age-related macular degeneration (AMD). To test whether the autophagy pathway plays a critical role to protect retinal pigmented epithelial (RPE) cells against oxidative stress, we exposed ARPE-19 and primary cultured human RPE cells to both acute (3 and 24 h) and chronic (14 d) oxidative stress and monitored autophagy by western blot, PCR, and autophagosome counts in the presence or absence of autophagy modulators. Acute oxidative stress led to a marked increase in autophagy in the RPE, whereas autophagy was reduced under chronic oxidative stress. Upregulation of autophagy by rapamycin decreased oxidative stress-induced generation of reactive oxygen species (ROS), whereas inhibition of autophagy by 3-methyladenine (3-MA) or by knockdown of ATG7 or BECN1 increased ROS generation, exacerbated oxidative stress-induced reduction of mitochondrial activity, reduced cell viability, and increased lipofuscin. Examination of control human donor specimens and mice demonstrated an age-related increase in autophagosome numbers and expression of autophagy proteins. However, autophagy proteins, autophagosomes, and autophagy flux were significantly reduced in tissue from human donor AMD eyes and 2 animal models of AMD. In conclusion, our data confirm that autophagy plays an important role in protection of the RPE against oxidative stress and lipofuscin accumulation and that impairment of autophagy is likely to exacerbate oxidative stress and contribute to the pathogenesis of AMD.

Authors+Show Affiliations

a Department of Ophthalmology ; Indiana University School of Medicine ; Indianapolis , IN USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

25484094

Citation

Mitter, Sayak K., et al. "Dysregulated Autophagy in the RPE Is Associated With Increased Susceptibility to Oxidative Stress and AMD." Autophagy, vol. 10, no. 11, 2014, pp. 1989-2005.
Mitter SK, Song C, Qi X, et al. Dysregulated autophagy in the RPE is associated with increased susceptibility to oxidative stress and AMD. Autophagy. 2014;10(11):1989-2005.
Mitter, S. K., Song, C., Qi, X., Mao, H., Rao, H., Akin, D., Lewin, A., Grant, M., Dunn, W., Ding, J., Bowes Rickman, C., & Boulton, M. (2014). Dysregulated autophagy in the RPE is associated with increased susceptibility to oxidative stress and AMD. Autophagy, 10(11), 1989-2005. https://doi.org/10.4161/auto.36184
Mitter SK, et al. Dysregulated Autophagy in the RPE Is Associated With Increased Susceptibility to Oxidative Stress and AMD. Autophagy. 2014;10(11):1989-2005. PubMed PMID: 25484094.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Dysregulated autophagy in the RPE is associated with increased susceptibility to oxidative stress and AMD. AU - Mitter,Sayak K, AU - Song,Chunjuan, AU - Qi,Xiaoping, AU - Mao,Haoyu, AU - Rao,Haripriya, AU - Akin,Debra, AU - Lewin,Alfred, AU - Grant,Maria, AU - Dunn,William,Jr AU - Ding,Jindong, AU - Bowes Rickman,Catherine, AU - Boulton,Michael, PY - 2014/12/9/entrez PY - 2014/12/9/pubmed PY - 2015/9/15/medline KW - 3-MA, 3-methyladenine KW - ACTB, β-actin KW - AMD, age-related macular degeneration KW - APOE4, apolipoprotein E4 KW - FACS, fluorescence-activated cell sorting KW - FBS, fetal bovine serum KW - GFP, green fluorescent protein KW - GSH, glutathione, reduced KW - GSSG, glutathione, oxidized KW - H2O2, hydrogen peroxide KW - HFC, high fat, cholesterol-enriched diet KW - LC3, microtubule-associated protein 1 light chain 3 KW - MMP, mitochondrial membrane potential KW - MTT, 3-(4 5-dimethylthiazol-3-yl)-2, 5-diphenyl tetrazolium bromide KW - ND, normal (rodent) diet KW - POS, photoreceptor outer segments KW - ROS, reactive oxygen species KW - RPE KW - RPE, retinal pigmented epithelium KW - SOD2/MnSOD, superoxide dismutase 2, mitochondrial KW - UPS, ubiquitin-proteasome system KW - age-related macular degeneration KW - aging KW - autophagy KW - oxidative stress SP - 1989 EP - 2005 JF - Autophagy JO - Autophagy VL - 10 IS - 11 N2 - Autophagic dysregulation has been suggested in a broad range of neurodegenerative diseases including age-related macular degeneration (AMD). To test whether the autophagy pathway plays a critical role to protect retinal pigmented epithelial (RPE) cells against oxidative stress, we exposed ARPE-19 and primary cultured human RPE cells to both acute (3 and 24 h) and chronic (14 d) oxidative stress and monitored autophagy by western blot, PCR, and autophagosome counts in the presence or absence of autophagy modulators. Acute oxidative stress led to a marked increase in autophagy in the RPE, whereas autophagy was reduced under chronic oxidative stress. Upregulation of autophagy by rapamycin decreased oxidative stress-induced generation of reactive oxygen species (ROS), whereas inhibition of autophagy by 3-methyladenine (3-MA) or by knockdown of ATG7 or BECN1 increased ROS generation, exacerbated oxidative stress-induced reduction of mitochondrial activity, reduced cell viability, and increased lipofuscin. Examination of control human donor specimens and mice demonstrated an age-related increase in autophagosome numbers and expression of autophagy proteins. However, autophagy proteins, autophagosomes, and autophagy flux were significantly reduced in tissue from human donor AMD eyes and 2 animal models of AMD. In conclusion, our data confirm that autophagy plays an important role in protection of the RPE against oxidative stress and lipofuscin accumulation and that impairment of autophagy is likely to exacerbate oxidative stress and contribute to the pathogenesis of AMD. SN - 1554-8635 UR - https://www.unboundmedicine.com/medline/citation/25484094/Dysregulated_autophagy_in_the_RPE_is_associated_with_increased_susceptibility_to_oxidative_stress_and_AMD_ L2 - http://www.tandfonline.com/doi/full/10.4161/auto.36184 DB - PRIME DP - Unbound Medicine ER -