Akt2 is required for macrophage chemotaxis

Eur J Immunol. 2009 Mar;39(3):894-901. doi: 10.1002/eji.200838809.

Abstract

Tumor-associated macrophages play an important role in tumorigenesis and metastasis. Trafficking of macrophages to the proximity of tumors is mediated by CSF-1, a growth factor. In this study, we investigated the role of PKB/Akt in CSF-1-induced macrophage migration. Disruption of Akt2 expression by small interference RNA impaired chemotaxis of both THP-1 cells and mouse peritoneal macrophages. Phosphorylation of PKCzeta, an essential component in chemotaxis signaling pathway, was reduced. LIMK/Cofilin, downstream of PKCzeta, regulated cytoskeleton rearrangement during cell migration. Disruption of Akt2 expression inhibited CSF-1-induced LIMK/Cofilin phosphorylation, which contributed to defects in actin polymerization and chemotaxis. Furthermore, MCP-1, a chemokine, -induced macrophage chemotaxis was also impaired. Taken together, our results demonstrated that Akt2 plays an essential role in both CSF-1- and chemokine-induced chemotaxis of macrophages.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actin Depolymerizing Factors / immunology
  • Actin Depolymerizing Factors / metabolism
  • Actins / immunology
  • Actins / metabolism
  • Animals
  • Cell Line
  • Chemokine CCL2 / immunology*
  • Chemokine CCL2 / metabolism
  • Chemotaxis / genetics
  • Chemotaxis / immunology*
  • Down-Regulation / immunology
  • Humans
  • Lim Kinases / immunology
  • Lim Kinases / metabolism
  • Macrophage Colony-Stimulating Factor / immunology
  • Macrophage Colony-Stimulating Factor / metabolism
  • Macrophages, Peritoneal / immunology*
  • Macrophages, Peritoneal / metabolism
  • Mice
  • Mice, Inbred BALB C
  • Proto-Oncogene Proteins c-akt / genetics
  • Proto-Oncogene Proteins c-akt / immunology*
  • RNA, Small Interfering / genetics

Substances

  • Actin Depolymerizing Factors
  • Actins
  • Chemokine CCL2
  • RNA, Small Interfering
  • Macrophage Colony-Stimulating Factor
  • AKT2 protein, human
  • Akt2 protein, mouse
  • Lim Kinases
  • Proto-Oncogene Proteins c-akt