CB2R inhibits the production of IL-1β but not IL-6 and TNF-α in cultured peritoneal macrophages stimulated with LPS/DSS.

After LPS (10 ng/ml) priming for 1 h, peritoneal macrophages were stimulated with 3% DSS in the presence or absence of HU 308 (10 μM) for 24 h. In another set of experiments, peritoneal macrophages from WT mice and CB2R KO mice were isolated and stimulated with/without LPS/DSS for 24 h. The levels of IL-1β, IL-6 and TNF-α were measured by ELISA. (A-C) Pre-incubated with HU 308 significantly decreased the level of IL-1β but have no effect on the levels of IL-6 and TNF-α. n = 6 per group. **P<0.01 vs. control, #P<0.05 vs. LPS/DSS+vehicle. (D-F) In comparison to WT group, the level of IL-1β was significantly increased in CB2R KO group, while the levels of IL-6 and TNF-α weren’t increased. n = 6 per group. **P<0.01 vs. control, ##P<0.01 vs. WT.