Fig. 6.

RelA and RelB increase RANKL expression by MPCs. Calvarial pre-osteoblasts from 7-day-old WT mice were infected with GFP control, RelA, or RelB retroviruses for 48 h. a RelA and b RelB mRNA expression tested by real-time PCR to confirm successful over-expression. Mean ± SD (n = 3 biologically independent samples; **p < 0.01; unpaired Student's t test). c RANKL mRNA expression tested by real-time PCR. Mean ± SD (n = 3; *p < 0.05, **p < 0.01; one-way ANOVA with Tukey’s post-hoc test). d Culture media collected from culture wells and RANKL protein levels measured by ELISA. Mean ± SD (n = 3 biologically independent samples; no significant difference; one-way ANOVA with Tukey’s post-hoc test). e Membrane-bound RANKL levels in 50,000 CD45-Sca-1+ MPCs tested by flow cytometry and expressed as mean fluorescence intensity (MFI). Average of 2 biologically independent samples from two individual experiments. All the in vitro experiments were repeated twice with similar results