CpG Oligodeoxynucleotides Inhibit RANKL-Induced Osteoclast Formation by Upregulating A20 Deubiquitinase in RAW 264.7 Cells

Figure 3

Deficiency of A20 deubiquitinase restored osteoclast formation. (a) c-Fos mRNA expression in A20 knockdown cells under stimulation with both RANKL (100 ng/ml) for 8 days and CpG-ODN for 6 days. (b) c-Fos, p-IκBα, and p-NF-κB protein expression in cells transfected with A20 siRNA under stimulation with both RANKL and CpG-ODN. (c, d) Under the same experimental conditions, osteoclast-specific molecules such as NFATc1, TRAP, cathepsin K, and CA-II were measured in A20 siRNA transfected RAW 264.7 cells incubated with both RANKL and CpG-ODN. (e–g) TRAP staining, number of TRAP-positive MNCs, and F-actin ring staining in cells transfected with A20 siRNA in the presence of both RANKL and CpG-ODN were preformed, respectively. Abbreviation: NC: negative control; NFATc1: nuclear factor of activated T cells c1; TRAP: tartrate-resistant acid phosphatase; CA-II: carbonic anhydrase-II. Error bars represent standard deviation of the measurement of three separate samples ( and ).

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