Abstract
Purpose:
We have previously shown that Bevacizumab is taken up in RPE cells and stored for at least seven days. In this study, we further investigate the mechanisms of uptake, focussing on the influence of sugar moieties.
Methods:
For the experiments, Arpe19 cells and primary porcine RPE cells of passage 2 and 3 were used. Cells were treated with 250 µg/ml Bevacizumab and evaluated after different time intervals (1 h - 7 d). Fucoidan or Mannan, respectively, was applied at a concentration of 100 µg/ml. Bevacizumab uptake was evaluated with immunofluorescence. Phagocytosis was measured in a phagocytosis assay using opsonized FITC latex beads. VEGF expression was determined in Western blot.
Results:
Fucoidan, but not Mannan, strongly reduces Bevacizumab uptake in RPE cells. Phagocytotic ability was not compromised by either Fucoidan or Mannan. Fucoidan, but not Mannan, significantly reduces VEGF165 and VEGF121 expression in Western blot.
Conclusions:
Fucoidan inhibits Bevacizumab uptake, which is not mediated via phagocytosis but may be connected to the reduction of VEGF expression in RPE cells by Fucoidan. This may hint towards uptake mechanism that involves immunocomplex binding.
Keywords: 701 retinal pigment epithelium •
748 vascular endothelial growth factor •
503 drug toxicity/drug effects