All-trans retinoic acid increases ARPE-19 cell apoptosis via activation of reactive oxygen species and endoplasmic reticulum stress pathways

Int J Ophthalmol. 2020 Sep 18;13(9):1345-1350. doi: 10.18240/ijo.2020.09.01. eCollection 2020.

Abstract

Aim: To explore the apoptosis of ARPE-19 cells after the treatment with different doses of all-trans-retinoic acid (ATRA).

Methods: ARPE-19 cells were used in the in-vitro experiment. Flow cytometry assay was employed to evaluate the level of reactive oxygen species (ROS) and apoptosis. The effects of ATRA (concentrations from 2.5 to 20 µmol/L) on the expression of endoplasmic reticulum stress (ERS) markers in vitro were evaluated by Western blot and real-time quantitative polymerase chain reaction (qRT-PCR) assays. The contribution of ROS and ERS-induced apoptosis in vitro was determined by using N-acetyl-L-cysteine (NAC) and Salubrinal, an antagonist of NAC and ERS, respectively.

Results: Flow cytometry showed that ATRA significantly increased ARPE-19 cell apoptosis and ROS levels in each group (F=86.39, P<0.001; F=116.839, P<0.001). Western blot and qRT-PCR revealed that levels of CHOP and BIP were elevated in a concentration-dependent pattern after the cells were incubated with ATRA (2.5-20 µmol/L). The upregulation of VEGF-A and CHOP induced by ATRA could be inhibited by NAC (antioxidant) and Salubrinal (ERS inhibitor) in vitro.

Conclusion: ATRA induces the apoptosis of ARPE-19 cells via activated ROS and ERS signaling pathways.

Keywords: all-trans-retinoic acid; apoptosis; endoplasmic reticulum stress; reactive oxygen species; retinal pigment epithelium.