title: Effect of bevacizumab on the expression of fibrosis-related inflammatory mediators in ARPE-19 cells.
abstract: OBJECTIVE
  To investigate the effect of anti-vascular epithelial growth factor (VEGF) agents on the expression of fibrosis-related 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, CoCl2at 200 µmol/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: CoCl2at 200 µmol/L was added to the media; 4) hypoxia+bevacizumab group: CoCl2at 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 48h.
  
  
  RESULTS
  Both mRNA 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 24h and IL-6 peaked at 12h after the bevacizumab treatment under both normoxic and hypoxic conditions.
  
  
  CONCLUSIONS
  Treatment of ARPE-19 cells with bevacizumab can significantly increase the expression of fibrosis-related inflammatory mediators under both normoxic and hypoxic conditions. Inflammatory factors might be involved in the process of fibrosis after anti-VEGF therapy, and the up-regulation of inflammatory factors induced by anti-VEGF drugs might promote the fibrosis process.
authors.affiliation: Qingdao University Medical College, Qingdao 266071, Shandong Province, China; Qingdao Eye Hospital, Shandong Eye Institute, Shandong Academy of Medical Sciences, Qingdao 266071, Shandong Province, China.
authors.forename: San-Jun
authors.initials: SJ
authors.lastname: Chu
authors.affiliation: Qingdao University Medical College, Qingdao 266071, Shandong Province, China; Qingdao Eye Hospital, Shandong Eye Institute, Shandong Academy of Medical Sciences, Qingdao 266071, Shandong Province, China.
authors.forename: Zhao-Hua
authors.initials: ZH
authors.lastname: Zhang
authors.affiliation: Qingdao Eye Hospital, Shandong Eye Institute, Shandong Academy of Medical Sciences, Qingdao 266071, Shandong Province, China.
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.affiliation: Qingdao Eye Hospital, Shandong Eye Institute, Shandong Academy of Medical Sciences, Qingdao 266071, Shandong Province, China.
authors.forename: Hai-Feng
authors.initials: HF
authors.lastname: Xu
keywords: bevacizumab; fibrosis; human retinal pigment epithelial cells; inflammatory mediators