Fig. 2.

Overexpression of CPE enhances osteoclast formation. BMMs were transduced with pMX vector (control) or CPE (pMX-CPE) retrovirus. (A) CPE expression was analyzed by RT-PCR. (B) BMMs were cultured with M-CSF (10 ng/ml) and the indicated concentrations of RANKL and stained for TRAP after 4 days. (C) The TRAP-positive multinucleated cells (MNCs) were counted. (D) TRAP activity was determined by measuring the OD values at 405 nm on day 4. The data are expressed as the means ± SD. *P < 0.05, **P < 0.001.