Macropinocytosis is involved in late phase of amylin oligomer internalization in RIN-m5F cells.

<p>Cells were either treated with EIPA, CytD and Wort for 1 hour or transfected with dynamin mutant construct, DN dyn1K44A for 16–18 hours followed by human amylin (10 µM) incubation for an additional 24 hours at 37°C. Dextran was finally added for 30 minutes. Confocal microscopy (<b>A</b>) and whole cell analysis (<b>B–C</b>) demonstrated a significant reduction in internalization and increase in PM accumulation of oligomers (<b>B</b>) and dextran (<b>C</b>) in the presence of macropinocytotic inhibitors. **P<0.01, hA vs. hA/inhibitors and^##P<0.01, dextran vs. dextran/inhibitors, n = 9. In contrast, expression of DN dyn1K44A in these cells failed to prevent entry of both oligomers and dextran. NS P>0.1, hA vs. hA/dyn1K44A and NS P>0.1, dextran vs. dextran/dyn1K44A, n = 9. Significance established by ANOVA followed by Dunnett-Square test. Bar 5µm.