Inhibition of expression (siRNAs) and phosphorylation (SIS3). Effect of silencing (siRNA) the expression of MAZ, NMP4, NFAT1-5, and SMAD3 on A) WWP2 and B) miR-140 expression in human osteoarthritic chondrocytes (n = 7 to 10). Effect of inhibiting SMAD3 phosphorylation following incubation of osteoarthritic chondrocytes (n = 8) without (control) or with the specific SMAD3 phosphorylation inhibitor SIS3 on the C) WWP2 and D) miR-140 expression. Each control (random-treated cells) was assigned an arbitrary value of 1 and the effect of the treatment evaluated as fold change over control. P values were assessed by the one-sample t-test, comparing the treated chondrocytes to the controls.