Visualization of specific interaction between biomimetic glycopolymer containing reducing glucose moiety and HepG2 cell mediated by GLUT-1.

Abstract

Poly [3-O-(4'-vinylbenzyl)-D-glucose] (PVG) is a polystyrene derivative that contains glucose moieties, which interact with glucose transporter (GLUT-1)-carrying HepG2 cells. To clarify the specific interaction between the PVG and HepG2 cells, PVG polymer labeled with fluorescent rhodamine-B isothiocyanate (RITC) was used to follow the specific interaction, which was visualized by confocal laser microscopy. We found that PVG binds strongly to HepG2 cells, probably because of a specific interaction mediated by the presence of GLUT-1 on the cell membrane. The fluorescence intensity of PVG and HepG2 cells was up to fourfold (0.11 +/- 0.04) that of any other glycopolymer and HepG2 cell interaction (0.025 +/- 0.01). Moreover, cellular fluorescence increased significantly on increasing the incubation time and the polymer concentration. To verify the specific nature of the interaction between PVG and HepG2 cells, the cells were pretreated with phloretin, an inhibitor of GLUT-1 before adding RITC-labeled PVG polymer to the cell culture medium; this treatment was found to suppress the action of PVG on HepG2 cells.