Requirement for PI 3-kinase gamma in macrophage migration to MCP-1 and CSF-1

Exp Cell Res. 2003 Oct 15;290(1):120-31. doi: 10.1016/s0014-4827(03)00318-5.

Abstract

Phosphoinositide 3-kinases (PI3Ks) are important regulators of cell migration. The PI3K isoform gamma is primarily expressed in haematopoietic cells, and is activated by G protein-coupled receptors (GPCRs). Here, we investigate the contribution of PI3Kgamma to macrophage responses to chemoattractants, using bone marrow-derived macrophages from wild-type and PI3Kgamma-null mice. We observe that early membrane ruffling induced by MCP-1, which activates a GPCR, or by CSF-1, which activates a tyrosine kinase receptor, is unaltered in PI3Kgamma(-/-) mice, although by 30 min MCP-1-induced cell polarization was strongly reduced in PI3Kgamma(-/-) compared to wild-type macrophages. The migration behaviour of the macrophages was analysed by time-lapse microscopy in Dunn chemotaxis chambers. PI3Kgamma(-/-) macrophages showed reduced migration speed and translocation, and no chemotaxis to MCP-1. Interestingly, there was also a reduction in migration efficiency in PI3Kgamma(-/-) macrophages stimulated with CSF-1 although early CSF-1R signalling was normal. These results indicate that the initial actin reorganization induced by either a GPCR or tyrosine kinase receptor agonist is not dependent on PI3Kgamma, whereas PI3Kgamma is needed for optimal migration of macrophages to either agonist.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actin Cytoskeleton / metabolism
  • Animals
  • Cell Membrane Structures / metabolism
  • Cell Migration Inhibition
  • Cell Polarity / drug effects
  • Cell Polarity / physiology
  • Cells, Cultured
  • Chemokine CCL2 / pharmacology*
  • Chemotaxis / drug effects
  • Chemotaxis / physiology*
  • Class Ib Phosphatidylinositol 3-Kinase
  • GTP-Binding Proteins / metabolism
  • Isoenzymes / deficiency*
  • Isoenzymes / genetics
  • Macrophage Colony-Stimulating Factor / pharmacology*
  • Macrophages / drug effects
  • Macrophages / enzymology*
  • Mice
  • Mice, Knockout
  • Phosphatidylinositol 3-Kinases / deficiency*
  • Phosphatidylinositol 3-Kinases / genetics
  • Receptor Protein-Tyrosine Kinases / metabolism
  • Receptors, Cell Surface / metabolism
  • Signal Transduction / drug effects
  • Signal Transduction / physiology

Substances

  • Chemokine CCL2
  • Isoenzymes
  • Receptors, Cell Surface
  • Macrophage Colony-Stimulating Factor
  • Phosphatidylinositol 3-Kinases
  • Class Ib Phosphatidylinositol 3-Kinase
  • Pik3cg protein, mouse
  • Receptor Protein-Tyrosine Kinases
  • GTP-Binding Proteins