Monosodium Urate in the Presence of RANKL Promotes Osteoclast Formation through Activation of c-Jun N-Terminal Kinase

Figure 1

Osteoclast formation induced by stimulation with MSU crystals in the presence of RANKL. (a) RAW 264.7 cells alone (controls) were incubated with MSU crystals alone (0.1 mg/mL), RANKL alone (100 ng/mL), or both for 24 h. , , and . (b) TRAP staining and actin ring staining were performed in cells incubated with MSU crystals alone (0.1 mg/mL), RANKL alone (100 ng/mL), or both for 10 days. and . (c) Production of TRAP protein was measured using the TRAP activity assay. RAW 264.7 cells alone (controls) were incubated with MSU crystals alone (0.1 mg/mL), RANKL alone (100 ng/mL), or both for 24 h. , , and . (d) The mRNA expression of osteoclast-specific genes was measured. RAW 264.7 cells were treated with both MSU crystals (0.1 mg/mL) and RANKL (100 ng/mL) for 24 h. and . (e) TRAP and actin ring staining were performed after stimulation of RAW 264.7 cells with both MSU crystals (0.1 mg/mL) and RANKL (100 ng/mL). and . (f) TRAP activity was measured and compared between RAW 264.7 cells incubated with both MSU crystals (0.1 mg/mL) and RANKL (100 ng/mL) and control cells. by ANOVA. (g) Functional assessment for activated osteoclasts was performed using the pit formation assay. The assay was performed at days 5, 7, and 10 after stimulation with both MSU crystals (0.1 mg/mL) and RANKL (100 ng/mL). Arrows indicate pits formed by activated osteoclasts. The experimental data were determined by at least three independent tests.

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