S632A3 promotes LPS-induced IFN-β production through inhibiting the activation of GSK-3β

LPS stimulation of macrophages production of IFN-β plays a key role in innate immunity defending the microbial invasion.  In this study, the effect of S632A3 promoting LPS-induced IFN-β production and the underlying mechanism were investigated.  mRNA level was measured by real-time PCR, cytokine production was determined by ELISA, GSK-3β activity was investigated by kinase assay, protein phosphorylation and expression were evaluated by Western blotting.  The results revealed that S632A3 significantly augmented IFN-β production by LPS-stimulated macrophages.  S632A3 inhibition of the activation of GSK-3β, reduced the threonine 239 phosphorylation of transcription factor c-Jun but increased the total level of c-Jun in LPS-stimulated macrophages.  Moreover, small interfering RNA-mediated knockdown of c-Jun level abrogated the ability of S632A3 to augment IFN-β.  The study thus demonstrates S632A3 being a new anti-inflammation lead compound and provides a molecular mechanism by which S632A3 promoted LPS-induced IFN-β production in macrophages through inhibiting the activation of GSK-3β.