Activin as an anti-inflammatory cytokine produced by microglia

The main objective of the present study was to determine if activin might inhibit microglial activation. In murine MG6 microglial cell cultures, lipopolysaccharide (LPS)-induced activation of these cells was mitigated by pretreatment with activin as assessed by compromised up-regulation of proinflammatory markers, including IL-18, IL-6 and iNOS. The suppressive effects of activin on microglial activation were similarly observed in rat brains administered with LPS into the lateral ventricle. The expression of activin mRNA was induced by treatment with LPS in both cell cultures and brains. Thus, activin might act as an anti-inflammatory cytokine produced by microglia, presumably modulating inflammation through an autocrine fashion.