Figure 3

Blocking bone resorbing activity of OCs with ZSTK474. Mouse bone marrow derived monocytic OC precursors were co-cultured with osteoblasts in the presence of 1α,25-(OH)₂D₃ on a collagen gel-coated dish. The matured OCs were collected and transferred onto dentin slices and incubated for 72 hours in the presence or absence of ZSTK474 and other PI3-K inhibitors. The dentin slices were stained with hematoxylin, and the pits formed in the resorbed area on the slices were observed (a) and measured (b) under a light microscope. (c) Matured OCs, differentiated from bone marrow cells as described above, were further cultured with 5 ng/ml of TNF-α and the PI3-K inhibitors. After 24 hours, TRAP-positive multinucleated cells were counted, and the percentages of surviving cells were calculated. The columns and bars indicate the mean and S.D. from duplicated wells in a) and c).