Figure 1.

HIF stimulates osteoclast-mediated bone resorption. A, B) Osteoclast cultures used for the microarray were exposed to normoxic or hypoxic conditions for 24 h and assessed for comparative osteoclast (OC) survival by counting the number of VNR-positive, multinucleated cells (A) and relative resorption by quantifying area of resorption and normalizing to osteoclast number (B). C) Western blot showing induction of HIF-1α and HIF-2α (5× overexposed compared with HIF-1α) in osteoclasts after 16 h of exposure to CoCl₂ (100 μM), desferrioxamine (DFO, 100 μM), MMOG (1 mM), or l-mimosine (l-mim, 100 μM). D, E) Quantification of osteoclast survival (D) and relative resorption (E) observed in osteoclasts exposed to these agents for 24 h. *P < 0.05; **P < 0.01; ***P < 0.001.