Fig. 5

AMPK activation is required for AICAR to attenuate CFA-induced inflammatory pain in mice. Compound C (20 μg, 80 μg/20 μl) was administrated at post-injection of CFA day 4 before AICAR (15 μg/20 μl) treatment for 30 min. a–d AMPK inhibitor Compound C (80 μg/20 μl) reversed the effects of AICAR (15 μg/20 μl). Effects of a single injection of Compound C (20 μg or 80 μg/20 μl) on mechanical allodynia (a) and thermal hyperalgesia (b) in CFA-injected mice with 15 μg/20 μl AICAR administration. Two-way ANOVA revealed a significant difference at ^*P < 0.05 vs. Control group and ^#P < 0.05 vs. CFA+VEH group (n = 8 each group). Skin tissues were collected at 2 h after AICAR treatment for Western blotting. Representative gels and quantification for p-AMPK and AMPK bands are shown (c, d). One-way ANOVA revealed a significant difference at ^*P < 0.05 vs. Control group and ^#P < 0.05 vs. CFA+VEH group. e–h Effects of AMPKα shRNA on CFA-induced mechanical allodynia, thermal hyperalgesia, and AICAR (15 μg/20 μl) treatment in mice (n = 5 mice/group). After the local administration of AMPKα shRNA, AICAR could not attenuate mechanical allodynia (e) and thermal hyperalgesia (f) and downregulated the level of AMPKα in inflamed tissues (g, h). Two-way ANOVA revealed a significant difference at ^#P < 0.05 vs. CFA + shRNA + 15μg AI group (e and f). One-way ANOVA revealed a significant difference at ^*P < 0.05 vs. CFA +scramble group (h). The abbreviations used here are VEH (vehicle of AICAR) and CC (Compound C, dissolve in DMSO (dimethyl sulphoxide))