Fig. 1

AGE-R1 protein expression, ligand binding and degradation are reduced in NOD mouse peritoneal macrophages. (A) Peritoneal macrophage membrane AGE-R1, -R2, and -R3 were determined by Western blot analysis on membrane extracts from 3- to 4-month-old ND-NOD, D-NOD, and ILI (control) mice (n = 10 per group). After electrophoresis on 12% gels, samples were transferred and immunoblotted with the respective anti-lgG, and visualized by ECL (anti-R1, 50 µg/ml; anti-R2, 50 µg/ml; anti-R3, 10 ug/ml). Molecular weights are indicated on the right side of the panel. Protein concentration used was 20 µg per lane. Data are representative of five identical experiments. (B) Binding of AGE-BSA to NOD mouse peritoneal macrophages (1 × 10⁶ per well, at 4°C for 2 hrs) using ¹²⁵I-AGE-BSA (0.1–0.5 µm) as a probe in the presence or absence of 50-fold excess unlabeled AGE-BSA. (C) Degradation of AGE-BSA by NOD mouse macrophages was performed at 37°C for 4 hrs and determined by measurement of trichloroacetic acid-soluble radioactivity in the medium. Data represent triplicate values and are expressed as the mean ± SEM. For panel B: p values: ND-NOD versus ILI, <.005; D-NOD versus ILI, NS. For panel C: p values: ND-NOD versus ILI: <.002, D-NOD versus ILI: NS.