Fig. 4

miR-449a and YY1 form a mutual inhibition loop in RA-FLS. RA-FLS were transfected with the YY1-siRNA, negative control siRNA (NC-siRNA), YY1 expression vector (YY1), or YY1 negative control vector (YY1-NC). The expression of YY1 was detected by qPCR (a, c) and western blotting (b, d). The expression of miR-449a was detected using qPCR (e). qPCR and western blotting were performed to detect the expression of YY1 after the transfection of miR-449a or miR-NC (f, g). h A putative miR-449a-binding site exists in the 3′UTR of YY1 mRNA. A Dual-Luciferase Reporter Assay was performed to validate the target relationship between miR-449a and YY1 (i). The IL-6 production in cell culture supernatants was detected by ELISA (j, n = 5). The results shown are the mean ± SD from three independent experiments. Student’s t test with Welch’s correction was used for the data analyses (a, c, f, and j). One-way ANOVA was used for the data analysis (e). Student’s t test was used for the data analysis in (i). *p < 0.05, **p < 0.01