Effects of MIP-1α on osteoclast-like cell formation induced by PTHrP or RANKL.

Long-term marrow cultures were treated with either PTHrP (0-50 ng/mL) or RANKL (0-50 ng/mL) (■), or with a combination of MIP-1α (100 pg/mL) and PTHrP or RANKL (▪). MIP-1α enhanced the effects of PTHrP (A) or RANKL (B) on osteoclast-like cell formation in long-term human marrow cultures. Results represent the mean ± SEM for quadruplicate determinations for a typical experiment. Similar results were seen in 2 independent experiments. *P < .05 compared to cultures lacking MIP-1α.