Fig. 5

A mechanical compressive force upregulates RANKL expression by PDLSCs, which further promotes osteoclast differentiation of mononuclear cells. A–B RT-PCR results showing that mechanical compressive forces significantly up-regulate RANKL expression by PDLSCs and it was significantly higher than DPSCs (P < 0.05), while the OPG expression of PDLSCs and DPSCs showed no significant difference (P > 0.05). C–D TRAP staining shows that the cell culture medium of PDLSCs after compressive stimulation can promote the osteoclast differentiation of mononuclear cells. The TRAP positive cell number was significantly higher than in the positive control group and in the DPSC group (P < 0.05), and OCs in the PDLSC group created significantly more erosion areas on osteo assay surface plates (P < 0.05). All results are representative of three repeated experiments. *p < 0.05; **p < 0.01. The scale bars in (C) and (E) are 10 μm