Endothelial cell cortactin coordinates intercellular adhesion molecule-1 clustering and actin cytoskeleton remodeling during polymorphonuclear leukocyte adhesion and transmigration.
Endothelial cell ICAM-1 interacts with leukocyte beta(2) integrins to mediate adhesion and transmit outside-in signals that facilitate leukocyte transmigration. ICAM-1 redistribution and clustering appear necessary for leukocyte transmigration, but the mechanisms controlling ICAM-1 redistribution and clustering have not been identified. We recently reported that Src kinase phosphorylation of endothelial cortactin regulates polymorphonuclear cell (PMN) transmigration. In this study, we tested the hypotheses that the Src family kinase-cortactin pathway mediates association of ICAM-1 with the actin cytoskeleton and that this association is required for ICAM-1 clustering and leukocyte transmigration. Cross-linking ICAM-1 induced cytoskeletal remodeling and a decrease in ICAM-1 lateral mobility, as assessed by fluorescence recovery after photobleaching. Cytoskeletal remodeling after ICAM-1 cross-linking was reduced by knockdown of cortactin by small interfering RNA, by expression of a cortactin mutant deficient in Src phosphorylation sites (cortactin3F), and by the Src kinase inhibitor PP2. Pretreatment of cytokine-activated human endothelial monolayers with cortactin small interfering RNA significantly decreased both actin and ICAM-1 clustering around adherent PMN and the formation of actin-ICAM-1 clusters required for PMN transmigration. Our data suggest a model in which tyrosine phosphorylation of cortactin dynamically links ICAM-1 to the actin cytoskeleton, enabling ICAM-1 to form clusters and facilitate leukocyte transmigration.
Yang
Lin
L
Center for Excellence in Vascular Biology, Departments of Pathology, Brigham and Women's Hospital and Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA.
Kowalski
Jennifer R
JR
Yacono
Patrick
P
Bajmoczi
Milan
M
Shaw
Sunil K
SK
Froio
Richard M
RM
Golan
David E
DE
Thomas
Sheila M
SM
Luscinskas
Francis W
FW
D008841:Actin Cytoskeleton / Q000378:metabolism*; D000199:Actins / Q000378:metabolism; D002448:Cell Adhesion / Q000235:genetics; D002465:Cell Movement / Q000235:genetics; D002478:Cells, Cultured; D051356:Cortactin / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism; D042783:Endothelial Cells / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism*; D009504:Neutrophils / Q000276:immunology*; D010766:Phosphorylation; D011743:Pyrimidines / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000235:genetics / Q000494:pharmacology; D014443:Tyrosine; D019061:src-Family Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
C412373:AG 1879; D000199:Actins; C495868:CTTN protein, human; D051356:Cortactin; D004791:Enzyme Inhibitors; D011743:Pyrimidines; D034741:RNA, Small Interfering; D018799:Intercellular Adhesion Molecule-1; D014443:Tyrosine; D019061:src-Family Kinases