Fig. 3.

KIM-1 mediated endocytosis of albumin was inhibited by specific KIM-1 antibody. A: NRK-52E cells were transfected with control GFP (green) plasmid for 48 h and then incubated with AF594-BSA (red) for 1 h. AF594-BSA intensities did not differ significantly between GFP positive (green) cells and negative (non-green) ones. B: Following transfection of NRK-52E cells with a fusion protein consisting of hKIM-1 and GFP (hKIM-GFP), AF594-BSA was accumulated in hKIM-GFP cells compared to hKIM-GFP negative ones (B: no hKIM Ab). Pre-incubation of the transfected cells with specific hKIM-1 antibody markedly inhibited AF594-BSA accumulation in hKIM-GFP cells, but it had no effect on endocytosis of AF594-BSA by hKIM-GFP-negative cells (B: +hKIM Ab). Staining was repeated at least three times with similar results. Images are Z-stack projections. C: AF594-dextran intensities were not different in hKIM-GFP-positive versus negative NRK-52E cells. D: Quantification of AF594-BSA fluorescence was done using the ImageJ Software directly on the microscopic images of labeled cells. n = 20–50 cells per group. *P < 0.01, **P < 0.001.