S100A9 Increases IL-6 and RANKL Expressions through MAPKs and STAT3 Signaling Pathways in Osteocyte-Like Cells

Figure 5

The effect of RAGE and TLR4 knockdown on IL-6 and RANKL expressions in osteocytes. When MLO-Y4-A2 cells reached 60–70% confluence, cells were transfected with RAGE-, TLR4-specific or negative control siRNA for 24 hours. ((a) and (b)) The effect of transfection with siRNA was determined by qRT-PCR. ((c) and (e)) Transfected cells were treated with S100A9 (50 nM) for 24 hours, and IL-6 and RANKL mRNA expressions were analyzed by qRT-PCR. ((d) and (f)) After 48 hours stimulation with S100A9 (50 nM), IL-6 and RANKL productions in transfected cells were measured using ELISA. All results of qRT-PCR were normalized by GAPDH mRNA expression levels. Data are means ± SD (n = 3). and show significant differences between the indicated groups.

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