Methotrexate decreases mRNA and protein expression of RANKL and RANK in rheumatoid arthritis synovial-derived fibroblasts. A significant decrease in the receptor activator of the NF-κB ligand (RANKL) mRNA levels (A) with no changes in osteoprotegerin (OPG) mRNA levels (B) in the presence of methotrexate (MTX). Representative blots and graphs showing decrease of cellular RANKL protein expression (C and D) with no changes in the cellular OPG expression (C and E) in the presence of MTX. Decrease of soluble RANKL protein expression (F) with no changes in the soluble OPG expression (G) in the presence of MTX, where results are quantified by enzyme-linked immunosorbent assay. *p<0.05.