JWH133 inhibits MPP+ -induced inflammatory response and iron influx in astrocytes

Background: We investigated the anti- inflammatory effect of type II cannabinoid receptor (CB2 receptor) activation and their relationship to iron influx on 1-methyl-4-phenylpyridinium (MPP+) treated astrocytes. Methods and Results: By western blots, real-time PCR and ELISA, the expressions of CB2 receptor, divalent metal transporter-1 (DMT1), cyclooxygenase-2 (COX-2), inducible nitric oxide (iNOS), interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) were measured. Iron influx into astrocytes was determined by the quenching of calcein fluorescence. We found that pre-treatment with JWH133, a selective CB2 receptor agonist, significantly suppressed the MPP+-induced up-regulation of COX-2, iNOS, IL- 1 beta and TNF-alpha in astrocytes. In addition, JWH133 significantly inhibited the MPP+-induced up- regulation of DMT1. Further studies indicated that JWH133 suppressed the MPP+-accelerated iron influx into astrocytes. These effects were blocked by co-treatment with AM630, the CB2 receptor antagonist. Conclusions: These results suggest that activation of CB2 receptor inhibit MPP+-induced inflammatory response and iron influx in astrocytes.