Neutrophil dysfunction in guanosine 3',5'-cyclic monophosphate-dependent protein kinase I-deficient mice.
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.
Werner
Claudia G
CG
Institut für Pharmakologie und Toxikologie, Technische Universität München, München, Germany. pharma@ipt.med-tu-muenchen.de
Godfrey
Virginia
V
Arnold
Roland R
RR
Featherstone
Gerald L
GL
Bender
Diane
D
Schlossmann
Jens
J
Schiemann
Matthias
M
Hofmann
Franz
F
Pryzwansky
Katherine B
KB
D000818:Animals; D001202:Ascitic Fluid / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D001854:Bone Marrow Cells / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D002118:Calcium / Q000037:antagonists & inhibitors / Q000378:metabolism; D019070:Cell Lineage / Q000235:genetics; D002464:Cell Migration Inhibition; D002634:Chemotaxis, Leukocyte / Q000235:genetics; D017869:Cyclic GMP-Dependent Protein Kinases / Q000096:biosynthesis / Q000172:deficiency* / Q000235:genetics* / Q000502:physiology; D003594:Cytoplasmic Granules / Q000201:enzymology / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D007958:Leukocyte Count; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018375:Neutrophil Activation / Q000235:genetics; D009504:Neutrophils / Q000201:enzymology* / Q000378:metabolism / Q000473:pathology*; D016897:Respiratory Burst / Q000235:genetics; D013481:Superoxides / Q000378:metabolism
D013481:Superoxides; D017869:Cyclic GMP-Dependent Protein Kinases; D002118:Calcium