PRKAB1 and rheumatoid arthritis: To evaluate the role of AMPK in regulating synovial inflammation, RA FLSs were treated with the AMPK agonist AICAR or inhibitor Compound C. Treatment with AICAR alone reduced the expression of IL-1β, IL-6, IL-8, and MMP-9 in TNFα-induced RA FLSs (Figure 4A), and Compound C had opposite effects.