miR-26a and toll-like receptor (TLR)3 expression in pristine-induced arthritis (PIA) rats with and without treatment with methotrexate (MTX). (A) Arthritis scores and (B), foot-pad perimeter in PIA rats with and without treatment with MTX. (C) RT-qPCR results of tlr3 mRNA and miR-26a expression in rat spleens from control, saline-treated PIA and MTX-treated PIA group on day 20 after pristane injection. U6 snRNA and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were used as internal controls in RT-qPCR for miRNA and mRNA expression detection, respectively. Bars represent the standard error of the mean from eight rats used in each group. *Statistically significant differences, (Mann–Whitney U-test), *PIA plus saline against control; ^PIA plus saline against PIA plus MTX; *,^P <0.05; **,^^P <0.01; ***,^^^P <0.001.