Neutrophil dysfunction in guanosine 3',5'-cyclic monophosphate-dependent protein kinase I-deficient mice

J Immunol. 2005 Aug 1;175(3):1919-29. doi: 10.4049/jimmunol.175.3.1919.

Abstract

The regulation of neutrophil functions by Type I cGMP-dependent protein kinase (cGKI) was investigated in wild-type (WT) and cGKI-deficient (cGKI-/-) mice. We demonstrate that murine neutrophils expressed cGKIalpha. Similar to the regulation of Ca2+ by cGKI in other cells, there was a cGMP-dependent decrease in Ca2+ transients in response to C5a in WT, but not cGKI-/- bone marrow neutrophils. In vitro chemotaxis of bone marrow neutrophils to C5a or IL-8 was significantly greater in cGKI-/- than in WT. Enhanced chemotaxis was also observed with cGKI-/- peritoneal exudate neutrophils (PE-N). In vivo chemotaxis with an arachidonic acid-induced inflammatory ear model revealed an increase in both ear weight and myeloperoxidase (MPO) activity in ear punches of cGKI-/- vs WT mice. These changes were attributable to enhanced vascular permeability and increased neutrophil infiltration. The total extractable content of MPO, but not lysozyme, was significantly greater in cGKI-/- than in WT PE-N. Furthermore, the percentage of MPO released in response to fMLP from cGKI-/- (69%) was greater than that from WT PE-N (36%). PMA failed to induce MPO release from PE-N of either genotype. In contrast, fMLP and PMA released equivalent amounts of lysozyme from PE-N. However, the percentage released was less in cGKI-/- (approximately 60%) than in WT (approximately 90%) PE-N. Superoxide release (maximum velocity) revealed no genotype differences in responses to PMA or fMLP stimulation. In summary, these results show that cGKIalpha down-regulates Ca2+ transients and chemotaxis in murine neutrophils. The regulatory influences of cGKIalpha on the secretagogue responses are complex, depending on the granule subtype.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Ascitic Fluid / enzymology
  • Ascitic Fluid / metabolism
  • Ascitic Fluid / pathology
  • Bone Marrow Cells / enzymology
  • Bone Marrow Cells / metabolism
  • Bone Marrow Cells / pathology
  • Calcium / antagonists & inhibitors
  • Calcium / metabolism
  • Cell Lineage / genetics
  • Cell Migration Inhibition
  • Chemotaxis, Leukocyte / genetics
  • Cyclic GMP-Dependent Protein Kinases / biosynthesis
  • Cyclic GMP-Dependent Protein Kinases / deficiency*
  • Cyclic GMP-Dependent Protein Kinases / genetics*
  • Cyclic GMP-Dependent Protein Kinases / physiology
  • Cytoplasmic Granules / enzymology
  • Cytoplasmic Granules / metabolism
  • Cytosol / metabolism
  • Leukocyte Count
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Neutrophil Activation / genetics
  • Neutrophils / enzymology*
  • Neutrophils / metabolism
  • Neutrophils / pathology*
  • Respiratory Burst / genetics
  • Superoxides / metabolism

Substances

  • Superoxides
  • Cyclic GMP-Dependent Protein Kinases
  • Calcium