FIGURE 4.

Osteopontin deficiency enhanced bone resorption activities of Col1a1-caPPR transgenic mice. a, TRAP staining of decalcified sections of the mesial metaphyses of the tibiae. Shown are osteoclast number per area (N.Oc, #/mm²) (b), osteoclast number per bone surface (N.Oc/BS, #/mm) (c), and osteoclast surface per bone surface (OcS/BS, %) (d) (*, p < 0.05; **, p < 0.01, n = 4 per group). e, urinary deoxypyridinoline (Dpyd) excretion levels (n = 6 per group). Cr, creatinine. OPN deficiency enhanced not only the number but also the activity of osteoclasts of Col1a1-caPPR transgenic mice. f, TRAP-positive multinucleated cell development of bone marrow cells. Osteoclastic cell cultures were set up from bone marrow tissues derived from all four mouse genotypes (n = 3 per group). Similar numbers of TRAP-positive multinucleated cells were generated in these cultures with no differences noted between genotypes.