Involvement of inflammasome activation in lipopolysaccharide-induced mice depressive-like behaviors.

Aims: The NLRP3 inflammasome is a cytoplasmic multiprotein complex of the innate immune system that regulates the cleavage of interleukin-1β and interleukin-18 precursors. It can detect a wide range of danger signals and trigger a series of immune-inflammatory reactions. There were plenty of studies indicating that activation of the immune system played pivotal roles in depression. However, the underlying mechanisms of immune-depression interactions remained elusive and there was no report about the involvement of inflammasome activation in depression.
Methods: We established an acute depression mouse model with lipopolysaccharide to explore the involvement of inflammasome activation in depression.
Results: The lipopolysaccharide-treated mice displayed depressive-like behaviors and pro-inflammatory cytokine interleukin-1β protein and mRNA levels significantly increased. The NLRP3 inflammasome mRNA expression level also significantly elevated in depressed mice brain. Pretreatment with the NLRP3 inflammasome inhibitor Ac-YVAD-CMK significantly abrogated the depressive-like behaviors induced by lipopolysaccharide.
Conclusion: These data suggest for the first time that the NLRP3 inflammasome is involved in lipopolysaccharide-induced mice depressive-like behaviors. The NLRP3 inflammasome may be a central mediator between immune activation and depression, which raises the possibility that it may be a more specific target for the depression treatments in the near future.
(© 2013 John Wiley & Sons Ltd.)