Fig. 6.

CP-25 inhibits arthritis progression in AA rats by modulating EP4 receptor signaling. a–b Effects of CP-25 on the expression of GRK2 and the EP4 receptor in FLSs in vivo. c Effects of CP-25 on the level of cAMP. *P < 0.05, **P < 0.01 vs. normal, ^#P < 0.05 vs. model ($\overline{x}$ ± s, n = 4). d–h Effects of CP-25 on the membrane EP4 receptor and GRK2 protein level on FLSs treated with an EP4 agonist in vitro. The EP4 receptor and GRK2 were identified by Western blotting d–f. The EP4 receptor was identified by flow cytometry g–h. *P < 0.05, **P < 0.01 vs. control, ^#P < 0.05, ^##P < 0.01 vs. CAY10598 ($\overline{x}$ ± s, n = 4)