FIGURE 6.

IRAK4 is a specific target for pathological osteolysis. A–D, PBS or LPS (50 mg/kg) was administered subcutaneously to the skull of wild-type or IRAK4-deficient mice. Five days later, osteolysis in calvariae was evaluated by micro-computed tomography (A), and osteoclast formation in calvariae was examined by TRAP staining (B) and immunohistochemical staining for cathepsin K or ISO-type control antibody (C) (bar, 100 μm; n = 3–5). Expression of Trap, Ctsk, and Rankl was also analyzed by real time PCR (D). Data represent means ± S.D. of Trap/Gapdh, Ctsk/Gapdh, or Rankl/Gapdh levels (*, p < 0.05; **, p < 0.01; NS, not significant; n = 4–11).