Neutrophils lacking platelet-endothelial cell adhesion molecule-1 exhibit loss of directionality and motility in CXCR2-mediated chemotaxis.
Time-lapsed videomicroscopy was used to study the migration of platelet-endothelial cell adhesion molecule-1-deficient (PECAM-1(-/-)) murine neutrophils undergoing chemotaxis in Zigmond chambers containing IL-8, KC, or fMLP gradients. PECAM-1(-/-) neutrophils failed to translocate up the IL-8, KC, and fMLP gradients. Significant reductions in cell motility and cell spreading were also observed in IL-8 or KC gradients. In wild-type neutrophils, PECAM-1 and F-actin were colocalized at the leading fronts of polarized cells toward the gradient. In contrast, in PECAM-1(-/-) neutrophils, although F-actin also localized to the leading front of migrating cells, F-actin polymerization was unstable, and cycling was remarkably increased compared with that of wild-type neutrophils. This may be due to the decreased cytokine-induced mobilization of the actin-binding protein, moesin, into the cytoskeleton of PECAM-1(-/-) neutrophils. PECAM-1(-/-) neutrophils also exhibited intracellularly dislocalized Src homology 2 domain containing phosphatase 1 (SHP-1) and had less IL-8-induced SHP-1 phosphatase activity. These results suggest that PECAM-1 regulates neutrophil chemotaxis by modulating cell motility and directionality, in part through its effects on SHP-1 localization and activation.
Wu
Yue
Y
Department of Pathology, Yale University Medical School, New Haven, CT 06520, USA.
Stabach
Paul
P
Michaud
Michael
M
Madri
Joseph A
JA
D000199:Actins / Q000378:metabolism; D000818:Animals; D048430:Cell Shape; D054360:Chemokine CXCL1; D018925:Chemokines; D019743:Chemokines, CXC; D002634:Chemotaxis, Leukocyte; D016207:Cytokines / Q000494:pharmacology; D016209:Interleukin-8 / Q000494:pharmacology; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D009504:Neutrophils / Q000166:cytology / Q000502:physiology*; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D054645:Protein Phosphatase 1; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism; D023063:Receptors, Interleukin-8B / Q000502:physiology*
D000199:Actins; D054360:Chemokine CXCL1; D018925:Chemokines; D019743:Chemokines, CXC; C475895:Cxcl1 protein, mouse; D016207:Cytokines; D016209:Interleukin-8; D047908:Intracellular Signaling Peptides and Proteins; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D023063:Receptors, Interleukin-8B; C074302:keratinocyte-derived chemokines; D054645:Protein Phosphatase 1; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D017027:Protein Tyrosine Phosphatases; C509248:Ptpn6 protein, mouse