pEF-RNMB-transfected or pEF-BOS-transfected COS-7 cells (10 μg) and non-transfected cells were grown on 100-mm dishes as described above. After two days, transfected and non-transfected cells were harvested by scraping in PBS containing 1% (w/v) EDTA, pelleted by centrifugation at 400 ×g for 10 min at 4°C, and stored at –80°C. The cell pellets and freshly dissected rat brains were homogenized in 3 mL of a solution containing 0.25 M sucrose, 1 mM EDTA (pH 8.0), and protease inhibitor Inhibitors,research,lifescience,medical cocktails (Complete Mini; Roche Applied Science, Mannheim, Germany) using a Teflon/glass homogenizer.
The homogenates were centrifuged at 1600 ×g for 10 min at 4°C, and the supernatant was centrifuged at
84,000 ×g for 30 min at 4°C. The pellets were resuspended in 3 mL of 50 mM Tris-HCl and 1 mM EDTA and recentrifuged at 84,000 ×g for 30 min at 4°C. The obtained pellets were resuspended in 0.1% SDS. Protein concentration was estimated by Inhibitors,research,lifescience,medical the BCA protein assay kit (Thermo Scientific, Rockford, IL) using BSA as a standard. Membrane preparations (3 or 20 μg of protein) were fractionated on SDS-polyacrylamide gels and electrophoretically transferred to polyvinylidene difluoride membranes (Millipore, Bedford, Inhibitors,research,lifescience,medical MA). The membranes were stained with 0.1% Coomassie Brilliant Blue R-250 (CBB) containing 10% acetic acid and 40% methanol, photographed, and rinsed in 100% methanol. Next, the membranes were blocked for 1 h at RT in PBS containing 0.1% Tween 20, 5% skimmed dry milk, 1% BSA, and 5% normal horse serum, followed by selleckchem overnight incubation at 4°C with anti-Gpnmb antibodies (0.3 μg/mL) in the Inhibitors,research,lifescience,medical blocking solution. The blots were washed and incubated with HRP-conjugated donkey anti-rabbit IgG antibody (1:3000; GE Healthcare). Immunoreactive (IR) bands were detected by chemiluminescence
on X-ray film (RX-U; Fuji Photo Film, Tokyo, Japan) using ECL reagents (GE Healthcare). Inhibitors,research,lifescience,medical Images were obtained using an image scanner (ES2200; Seiko Epson, Nagano, Japan) and Adobe Photoshop software. Immunoperoxidase staining Rats were transcardially perfused with PBS followed by perfusion with a fixative containing 4% PFA in 0.1 M PB after deep anesthetia with diethyl ether and chloral hydrate. Brains were removed Casein kinase 1 immediately and postfixed in the same fixative overnight at 4°C and then cryoprotected for two days at 4°C with 30% sucrose in 0.1 M PB. Sections at a thickness of 16 or 18 μm were cut using a cryostat and collected in PBS. Free-floating sections were sequentially incubated in (1) blocking solution (PBS containing 0.3% Triton X-100, 1% BSA, and 1.5% normal goat serum) for 1 h at 4°C; (2) affinity-purified anti-rat Gpnmb antibodies (0.3 μg/mL in the blocking solution) overnight at 4°C; (3) PBS containing 0.