title: Frutalin, a galactose-binding lectin, induces chemotaxis and rearrangement of actin cytoskeleton in human neutrophils: involvement of tyrosine kinase and phosphoinositide 3-kinase.
abstract: Several lectin-like molecules have been shown as potent activators of leukocytes. Galactose-binding lectins are of special interest since they could interact with several endogenous molecules involved in the innate and specific immune responses. The effects of Frutalin (FTL), an alpha-D-galactose (Gal)-binding plant lectin, on the modulation of neutrophil (PMN) functions were investigated. FTL induced a dose-dependent PMN migration in mice pleural cavity. Moreover, FTL was also a potent direct chemotactic for human PMN, in vitro, and triggered oxidative burst in these cells. These effects were accompanied by a rearrangement of the actin cytoskeleton dynamic, activation of tyrosine kinase (TK) pathways, increase in focal adhesion kinase (FAK) phosphorylation, and its subsequent association to phosphoinositide3-kinase (PI3K). All those effects were inhibited in the presence of Gal, suggesting specific carbohydrate recognition for FTL effects. The activations of TK and PI3K pathways are essential events for FTL-induced chemotaxis, since inhibitors of these pathways, genistein and LY294002, inhibited neutrophil migration in vitro. The data indicate that sugar-protein interactions between a soluble lectin and galacto-components on neutrophil surface trigger the TK pathway, inducing FAK and PI3K activation, interfering with cell motility and oxidative response.
authors.affiliation: Departamento de Farmacologia, Instituto de Biologia, Universidade do Estado do Rio de Janeiro, Av. 28 de setembro 87 fds, Vila Izabel, Rio de Janeiro RJ 20551-030, Brazil.
authors.forename: Aline C
authors.initials: AC
authors.lastname: Brando-Lima
authors.forename: Roberta F
authors.initials: RF
authors.lastname: Saldanha-Gama
authors.forename: Maria das Graças M O
authors.initials: Md
authors.lastname: Henriques
authors.forename: Ana C O
authors.initials: AC
authors.lastname: Monteiro-Moreira
authors.forename: Renato A
authors.initials: RA
authors.lastname: Moreira
authors.forename: Christina
authors.initials: C
authors.lastname: Barja-Fidalgo
mesh_terms: D000199:Actins / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D031622:Artocarpus / Q000737:chemistry; D015153:Blotting, Western; D002634:Chemotaxis, Leukocyte / Q000187:drug effects*; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D005434:Flow Cytometry; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D005690:Galactose / Q000378:metabolism; D037161:Galectins / Q000494:pharmacology*; D047468:Immunoprecipitation; D037102:Lectins / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D010998:Pleurisy / Q000473:pathology; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D016897:Respiratory Burst / Q000187:drug effects; D012639:Seeds / Q000737:chemistry; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D000199:Actins; D037161:Galectins; D037102:Lectins; D009240:N-Formylmethionine Leucyl-Phenylalanine; D019869:Phosphatidylinositol 3-Kinases; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496051:Ptk2 protein, mouse; D005690:Galactose