Convergence of the mammalian target of rapamycin complex 1- and glycogen synthase kinase 3-β-signaling pathways regulates the innate inflammatory response

J Immunol. 2011 May 1;186(9):5217-26. doi: 10.4049/jimmunol.1002513. Epub 2011 Mar 21.

Abstract

The PI3K pathway and its regulation of mammalian target of rapamycin complex 1 (mTORC1) and glycogen synthase kinase 3 (GSK3) play pivotal roles in controlling inflammation. In this article, we show that mTORC1 and GSK3-β converge and that the capacity of mTORC1 to affect the inflammatory response is due to the inactivation of GSK3-β. Inhibition of mTORC1 attenuated GSK3 phosphorylation and increased its kinase activity. Immunoprecipitation and in vitro kinase assays demonstrated that GSK3-β associated with a downstream target of mTORC1, p85S6K, and phosphorylated GSK3-β. Inhibition of S6K1 abrogated the phosphorylation of GSK3-β while increasing and decreasing the levels of IL-12 and IL-10, respectively, in LPS-stimulated monocytes. In contrast, the direct inhibition of GSK3 attenuated the capacity of S6K1 inhibition to influence the levels of IL-10 and IL-12 produced by LPS-stimulated cells. At the transcriptional level, mTORC1 inhibition reduced the DNA binding of CREB and this effect was reversed by GSK3 inhibition. As a result, mTORC1 inhibition increased the levels of NF-κB p65 associated with CREB-binding protein. Inhibition of NF-κB p65 attenuated rapamycin's ability to influence the levels of pro- or anti-inflammatory cytokine production in monocytes stimulated with LPS. These studies identify the molecular mechanism by which mTORC1 affects GSK3 and show that mTORC1 inhibition regulates pro- and anti-inflammatory cytokine production via its capacity to inactivate GSK3.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Blotting, Western
  • Bone Marrow Cells / immunology
  • Bone Marrow Cells / metabolism
  • Cell Separation
  • Cytokines / biosynthesis
  • Dendritic Cells / immunology
  • Dendritic Cells / metabolism
  • Enzyme-Linked Immunosorbent Assay
  • Flow Cytometry
  • Gene Expression
  • Gene Expression Profiling
  • Gene Expression Regulation / immunology
  • Glycogen Synthase Kinase 3 / immunology*
  • Glycogen Synthase Kinase 3 / metabolism
  • Glycogen Synthase Kinase 3 beta
  • Humans
  • Immunity, Innate / immunology*
  • Immunoprecipitation
  • Inflammation / immunology
  • Inflammation / metabolism
  • Macrophages / immunology
  • Macrophages / metabolism
  • Mechanistic Target of Rapamycin Complex 1
  • Monocytes / immunology
  • Monocytes / metabolism
  • Multiprotein Complexes
  • Proteins / immunology*
  • Proteins / metabolism
  • Signal Transduction / immunology*
  • TOR Serine-Threonine Kinases

Substances

  • Cytokines
  • Multiprotein Complexes
  • Proteins
  • TOR Serine-Threonine Kinases
  • Glycogen Synthase Kinase 3 beta
  • Mechanistic Target of Rapamycin Complex 1
  • Glycogen Synthase Kinase 3

Associated data

  • GEO/GSE25520