Resveratrol As Inducer Of Autophagy And Prosurvival Stimulus In Cultured ARPE-19 Cells

Abstract

Purpose: : To investigate the effect of resveratrol (3,5,4'-trihydroxy-trans-stilbene), a polyphenolic natural plant product, on cell death and autophagy in human retinal pigment epithelium-derived ARPE-19 cells.

Methods: : ARPE-19 cells were exposed to different treatment regimens: 10-50microM resveratrol, 50-100 nM rapamycin (RAP), 50 microM chloroquine (CQ) and 50-100 nM proteasome inhibitor MG-312 over 48 hours. The levels of LC3-II, mammalian target of rapamycin (mTOR), Hsp70, p62 were determined by Western blot analysis; autophagic vacuoles (AVs) formation was detected by acridine orange, LC3 immunostaining and transmission electron microscopy; cell death was quantified using annexin-V-FITC/propidium iodide (PI) labeling on flow cytometry.

Results: : Exposure to RAP and MG-132 caused a time- and concentration dependent induction of autophagy that could be inhibited by 3-methyladenine (3-MA), while the induction of an active autophagic flux could be verified with CQ treatment, a blocker of the autophagosome-lysosome fusion. Similarly, resveratrol alone could induce autophagy in ARPE-19 cells, serving as a pro-survival signal in ARPE-19 cells (<2% of the cells were annexin-V+ and <1% were annexin-V+/PI+ at 24 hrs). Inhibition with 3-MA increased the death rate of resveratrol treated ARPE-19 cell, further proving the autophagy-related protective role of resveratrol. RAP and resveratrol co-treatment did not significantly affect the amount of AVs nor its cell survival effects.

Conclusions: : Resveratrol at lower concentrations can provide a pro-survival stimulus to ARPE-19 cells by inducing autophagy. This property can possibly be used for prolonging the lifespan of retinal pigment epithelium in diseases such as age-related macular degeneration.

Keywords: retinal pigment epithelium • apoptosis/cell death • age-related macular degeneration