Figure 6.

Cubilin antibodies inhibit HDL internalization and degradation. (a–c) RA/Bt₂cAMP-treated F9 cells were incubated with apoE-free DiI-HDL alone or in the presence of unlabeled HDL, RAP, anticubilin IgG, antimegalin/LRP-2, or control IgG. (d) Treated F9 cells were incubated with DiO-LDL alone or in the presence of unlabeled LDL, HDL, RAP, antimegalin/LRP-2 IgG, or control IgG. (a, c, and d) Percentage of cells that internalized DiI-HDL or DiO-LDL in the presence or absence of the indicated agents. (b) Mean fluorescence intensity values of the cells (in a) that internalized DiI-HDL in the presence or absence of the indicated agents. Cells (1 × 10⁴) were analyzed for each value plotted in a–d. Data in a–d are representative of three experiments. (e and f) Amounts of ¹²⁵I-HDL internalized (e) and degraded (f) by RA/Bt₂cAMP-treated F9 cells incubated with apoE-free ¹²⁵I-HDL in assay medium alone or in assay medium containing unlabeled HDL, RAP, chloroquine, BSA, anticubilin IgG, or control IgG. Values in e and f are means ± SD of triplicate values.