Effect of bevacizumab on the expression of fibrosis-related inflammatory mediators in ARPE-19 cells

AIM：To investigate the effect of anti-vascular epithelial growth factor（VEGF）agents on the expression of fibrosisrelated inflammatory mediators under normoxic and hypoxic conditions,and to further clarify the mechanism underlying fibrosis after anti-VEGF therapy. METHODS：Human retinal pigment epithelial（RPE）cells were incubated under normoxic and hypoxic conditions.For hypoxia treatment,CoCl_2 at 200μmol/L was added to the media. ARPE-19 cells were treated as following：1）control group：no treatment; 2）bevacizumab group：bevacizumab at 0.25 mg/mL was added to the media; 3）hypoxia group：CoCl_2 at 200 μmol/L was added to the media; 4）hypoxia＋bevacizumab group：CoCl_2 at 200 μmol/L and bevacizumab at 0.25 mg/mL were added to the media.The expression of interleukin（IL）-1β,IL-6,IL-8 and tumor necrosis factor（TNF）-α were evaluated using real-time polymerase chain reaction（RT-PCR）and enzyme-linked immunosorbent assay（ELISA）at 6,12,24 and 48 h. RESULTS：Both m RNA and protein levels of IL-1β,IL-6 and IL-8 were statistically significantly higher in the bevacizumab group than in the control group at each time point,and TNF-α gene and protein expression was only significantly higher only at 24 and 48h（P〈0.05）. Under hypoxic conditions,bevacizumab significantly increased the expression of IL-1β,IL-6,IL-8 and TNF-α at 6,12,24 and 48h（P〈0.05）. IL-1β,IL-8 and TNF-α peaked at 24 h and IL-6 peaked at 12 h after the bevacizumab treatment under both normoxic and hypoxic conditions. CONCLUSION：Treatment of ARPE-19 cells with bevacizumab can significantly increase the expression of fibrosis-related inflammatory mediators under bothnormoxic and hypoxic conditions. Inflammatory factors might be involved in the process of fibrosis after antiVEGF therapy,and the up-regulation of inflammatory factors induced by anti-VEGF drugs might promote the fibrosis process.