Figure 3.

Noggin expression in bone marrow–derived macrophages. Bone marrow–derived macrophages (Mφ) isolated from bone marrow cell cultures in the presence of M-CSF examined for noggin and BMP-4 expression by real-time PCR (a) and Western blot (b and c). Expression levels in macrophages in a were described as a ratio to those in U-33 preosteoblasts. In b, noggin expression in macrophages and U-33 cells were detected by Western blotting. In c, macrophages were cultured in the presence or absence of 300 ng/ml BMP-2 for 3 days, and noggin expression was analyzed by Western blotting. *P < 0.05, significantly different from U-33 cells by ANOVA. Cont, control.