Bevacizumab modulates retinal pigment epithelial-to-mesenchymal transition via regulating Notch signaling

AIM: To Investigate the effect of bevacizumab treatment on Notch signaling and the induction of epithelial -of -mesenchymal transition (EMT) in human retinal pigment epithelial cells (ARPE-19) in win,. METHODS: In vitro cultivated ARPE -19 cells were treated with 0.25 mg/mL bevacizumab for 12, 24, and 48h. Cell morphology changes were observed under an inverted microscope. The expression of zonula occludens-1 (ZO-1), vimentin and Notch-1 intracellular domain (NICD) was examined by immunofluorescence. The mRNA levels of ZO-1, alpha-SMA, Notch-1, Notch-2, Notch-4, D114, Jagged-1, RBP-Jk and Hes-1 expression were evaluated with quantitative real -time polymerase chain reaction (qRT-PCR). The protein levels of alpha-SMA, NICD, Hes -1 and DII-4 expression were examined with Western blot. RESULTS: Bevacizumab stimulation increased the expression of alpha -SMA and vimentin in ARPE -19 cells which changed into spindle-shaped fibroblast-like cells. Meanwhile, the mRNA expression of Hes -1 increased and the protein expression of Hes -1 and NICD also increased, which Notch signaling was activated. The mRNA expression of Notch -1, Jagged -1 and RBP -Jk Increased at 48h, and while DII4 mRNA and protein expression did not change after bevacizumab treatment. CONCLUSION: Jagged-1/Notch-1 signaling may play a critical role in bevacizumab -induced EMT in ARPE -19 cells, which provides a novel insight into the pathogenesis of intravitreal bevacizumab -associated complication.