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

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 20μmol/L)on the expression of endoplasmic reticulum stress(ERS)markers in vitro were evaluated by Western blot and realtime 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(2.5-20μmol/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.