Interleukin-20 Acts as a Promotor of Osteoclastogenesis and Orthodontic Tooth Movement

Figure 4

Robust expression of IL-20 significantly activated the RANKL-mediated downstream signalling pathway. siRNA reduction of IL-20 expression in BMMs led to significant inhibition of the RANKL-mediated downstream signalling pathway; moreover, siRNA reduction of IL-20RB, a key receptor for IL-20, in BMMs led to inhibition of IL-20-modulated downstream signalling pathways. (a) Bone marrow-derived mononuclear cells were transfected with siRNA carrying Cy3 dye and imaged with a fluorescence-inverted microscope to confirm the presence of siRNA within the cells. (b and c) qRT-PCR and western blotting analyses verified the inhibition of IL-20 and IL-20RB expression by siRNA at different concentrations (10–100 μM of each siRNA sequence); three siRNA sequences were designed and synthesised for each gene. (d and e) Western blotting analysis was used to detect the RANKL-mediated downstream signalling pathway protein expression levels in BMMs transfected with IL-20 siRNA, IL-20RB siRNA with 20 ng/mL IL-20, and the IL-20 overexpression plasmid for 2 days; examined proteins included p-Iκkα, p-Iκkβ, p-p65, JNK, TRAF6, IκK, NF-κB, NFATc1, and p-38. Bars represent the of three independent experiments (). vs. control group; N.S.: not significant.

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