Nicotinamide suppresses bevacizumab-induced epithelial-mesenchymal transition of ARPE-19 cells by attenuating oxidative stress

摘要

AIM:To investigate the effects of nicotinamide(NAM)on bevacizumab(BEV)-induced epithelial-mesenchymal transition(EMT)of human retinal pigment epithelial cells(ARPE-19)and the underling mechanisms.METHODS:ARPE-19 cells were treated with BEV for 24,48,and 72 h,and the variation degrees of EMTrelated markers(fibronectin,α-SMA,vimentin,and ZO-1)were assessed by Western blotting to select the optimal treatment time point which exhibited the most obvious changes of EMT-related markers for the subsequent experiments.Furthermore,NAM was added to the medium,the m RNA and protein levels of the EMT-related markers were then measured.The accumulation of reactive oxygen species(ROS)and H_(2)O_(2)and the total antioxidant capacity(TAC)of the cells were also measured to evaluate the level of oxidative stress.RESULTS:After being treated with BEV for 72 h,the protein expression levels of EMT-related markers in ARPE-19 cells showed significant changes.Meanwhile the levels of ROS and H_(2)O_(2)were obviously increased,and the TAC of ARPE-19 cells was decreased.Totally 72 h was chosen to be the optimal treatment time point in subsequentexperiments.Furthermore,NAM inhibited BEV-induced EMT by downregulating fibronectin,α-SMA,and vimentin and upregulating ZO-1,decreased the accumulation of ROS and H_(2)O_(2),and enhanced TAC in BEV-treated ARPE-19 cells.CONCLUSION:This study demonstrates that NAM suppressed BEV-induced EMT in ARPE-19 cells by attenuating oxidative stress.Hence,NAM may be a potential therapeutic agent for alleviating neovascular fibrosis of the ocular fundus after anti-vascular endothelial growth factor therapy.