Fluid shear stress induces actin polymerization in human neutrophils.
We have previously reported that a physiological range of shear stress induces neutrophil homotypic aggregation mediated by lymphocyte function-associated antigen-1 (LFA-1) and intercellular adhesion molecule-3 (ICAM-3) interactions. To further characterized the homotypic aggregation, actin polymerization was investigated in neutrophils stimulated by shear stress in comparison with formyl-methionyl-leucyl-phenylalanine (fMLP). In fMLP-stimulated neutrophils, actin polymerization was localized in the pseudopods, and this reaction was not mediated by a cytosolic level of Ca2+. In contrast to fMLP stimulation, the actin polymerization induced by shear stress in a cone-plate viscometer was localized in cell-cell contact regions, and this polymerization required the increase of intracellular Ca2+. This shear stress-induced actin polymerization was not observed when neutrophils were pretreated with anti-LFA-1 or anti-ICAM-3 antibody. In conclusion, LFA-1 and ICAM-3 interaction mediated by the increase of [Ca2+]i generated the intercellular signal in order to accumulate F-actin in the cell-cell contact regions.
Okuyama
M
M
Department of Surgery II, Osaka University Medical School, Japan.
Ohta
Y
Y
Kambayashi
J
J
Monden
M
M
D000199:Actins / Q000187:drug effects / Q000378:metabolism*; D019138:Antibodies, Blocking / Q000276:immunology; D015703:Antigens, CD; D000943:Antigens, Differentiation; D002118:Calcium / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000276:immunology; D003600:Cytosol / Q000378:metabolism; D006801:Humans; D016169:Lymphocyte Function-Associated Antigen-1 / Q000276:immunology; D018613:Microscopy, Confocal; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D018375:Neutrophil Activation; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D011108:Polymers / Q000378:metabolism*; D011554:Pseudopodia / Q000378:metabolism; D015398:Signal Transduction; D013314:Stress, Mechanical
D000199:Actins; D019138:Antibodies, Blocking; D015703:Antigens, CD; D000943:Antigens, Differentiation; D015815:Cell Adhesion Molecules; C483616:ICAM3 protein, human; D016169:Lymphocyte Function-Associated Antigen-1; D011108:Polymers; D009240:N-Formylmethionine Leucyl-Phenylalanine; D002118:Calcium