tailieunhanh - Báo cáo khoa học: Role of Ca2+/calmodulin regulated signaling pathways in chemoattractant induced neutrophil effector functions Comparison with the role of phosphotidylinositol-3 kinase

In human neutrophils, both changes in intracellular Ca 2+ concentrations, [Ca 2+ ] i , and activation of phosphatidyl-inositol-3 kinase (PtdIns3K) have been proposed to play a role in regulating cellular function induced by chemoattr-actants. In this studywe have investigated the role of [Ca 2+ ] i and its effector molecule calmodulin in human neutrophils. | Eur. J. Biochem. 269 4625-4634 2002 FEBS 2002 doi Role of Ca2 calmodulin regulated signaling pathways in chemoattractant induced neutrophil effector functions Comparison with the role of phosphotidylinositol-3 kinase Sandra Verploegen Caroline M. van Leeuwen Hanneke W. M. van Deutekom Jan-Willem J. Lammers Leo Koenderman and Paul J. Coffer Department of Pulmonary Diseases University Medical Center Utrecht the Netherlands In human neutrophils both changes in intracellular Ca2 concentrations Ca2 i and activation of phosphatidyl-inositol-3 kinase PtdIns3K have been proposed to play a role in regulating cellular function induced by chemoattractants. In this study we have investigated the role of Ca2 i and its effector molecule calmodulin in human neutrophils. Increased Ca2 i alone was sufficient to induce phosphorylation of extracellular signal-regulated protein kinase 2 ERK2 p38 mitogen activated kinase p38 MAPK protein kinase B PKB and glycogen synthase kinase-3a GSK-3a . Inhibition of calmodulin using a calmodulin antagonist N- 6-aminohexyl -5-chloro-1-naphthalenesulfo-namide W7 did not effect N-formyl-methionyl-leucyl-phenylalanine fMLP induced ERK p38 MAPK or GSK-3a phosphorylation but attenuated fMLP iduceed PKB phosphorylation. PCR analysis of human neutrophil cDNA demonstrated variable expression of members of the Ca2 calmodulin-dependent kinase family. The roles of calmodulin and PtdIns3K in regulating neutrophil effector functions were further compared. Neutrophil migration was abrogated by inhibition of calmodulin while no effect was observed when PtdIns3K was inhibited. In contrast production of reactive oxygen species was sensitive to inhibition of both calmodulin and PtdIns3K. Finally we demonstrated that chemoattractants are unable to modulate neutrophil survival despite activation of PtdIns3K and elevation Ca2 i. Taken together our data indicate critical roles for changes in Ca2 i and calmodulin activity in regulating .