title: Role of lipid raft components and actin cytoskeleton in fibronectin-binding, surface expression, and de novo synthesis of integrin subunits in PGE2- or 8-Br-cAMP-stimulated mastocytoma P-815 cells.
abstract: Integrins are heterodimeric adhesion receptors essential for adhesion of non-adherent cells to extracellular ligands such as extracellular matrix components. The affinity of integrins for ligands is regulated through a process termed integrin activation and de novo synthesis. Integrin activation is regulated by lipid raft components and the actin structure. However, there is little information on the relationship between integrin activation and its de novo synthesis. Cancerous mouse mast cells, mastocytoma P-815 cells (P-815 cells) are known to bind to fibronectin through de novo synthesis of integrin subtypes by prostaglandin (PG) E2 stimulation. The purpose of this study was to clarify the relationship between lipid raft components and the actin cytoskeleton, and PGE2-induced P-815 cells adhesion to fibronectin and the increase in surface expression and mRNA and protein levels of αvβ3 and αIIbβ3 integrins. Cholesterol inhibitor 6-O-α-maltosyl-β cyclodextrin, glycosylphosphatidylinositol-anchored proteins inhibitor phosphatidylinositol-specific phospholipase C and actin inhibitor cytochalasin D inhibited PGE2-induced cell adhesion to fibronectin, but did not regulate the surface expression and mRNA and protein levels of αv and αIIb, and β3 integrin subunits. In addition, inhibitor of integrin modulate protein CD47 had no effect on PGE2- and 8-Br-cAMP-induced cell adhesion. These results suggest that lipid raft components and the actin cytoskeleton are directly involved in increasing of adhesion activity of integrin αIIb, αv and β3 subunits to fibronectin but not in stimulating of de novo synthesis of them in PGE2-stimulated P-815 cells. The modulation of lipid rafts and the actin structure is essential for P-815 cells adhesion to fibronectin.
authors: Department of Physiological Chemistry, Faculty of Pharmaceutical Sciences, Institute for Biosciences, Mukogawa Women's University, 11-68 Koshien-Kyubancho, Nishinomiya-shi, Hyogo 663-8179, Japan.
authors: Yasuyo
authors: Y
authors: Okada
authors: Department of Physiological Chemistry, Faculty of Pharmaceutical Sciences, Institute for Biosciences, Mukogawa Women's University, 11-68 Koshien-Kyubancho, Nishinomiya-shi, Hyogo 663-8179, Japan.
authors: Jyun-ichi
authors: J
authors: Nishikawa
authors: Department of Physiological Chemistry, Faculty of Pharmaceutical Sciences, Institute for Biosciences, Mukogawa Women's University, 11-68 Koshien-Kyubancho, Nishinomiya-shi, Hyogo 663-8179, Japan.
authors: Masanori
authors: M
authors: Semma
authors: Department of Physiological Chemistry, Faculty of Pharmaceutical Sciences, Institute for Biosciences, Mukogawa Women's University, 11-68 Koshien-Kyubancho, Nishinomiya-shi, Hyogo 663-8179, Japan. Electronic address: aichikaw@mukogawa-u.ac.jp.
authors: Atsushi
authors: A
authors: Ichikawa
mesh_terms: D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology*; D008841:Actin Cytoskeleton / Q000378:metabolism*; D000818:Animals; D051928:CD47 Antigen / Q000378:metabolism; D002448:Cell Adhesion; D045744:Cell Line, Tumor; D002784:Cholesterol / Q000378:metabolism; D015232:Dinoprostone / Q000494:pharmacology*; D005353:Fibronectins / Q000378:metabolism*; D039564:Integrin alphaV / Q000096:biosynthesis / Q000235:genetics; D039661:Integrin beta3 / Q000096:biosynthesis / Q000235:genetics; D016023:Integrins / Q000096:biosynthesis* / Q000235:genetics; D034801:Mastocytoma; D021962:Membrane Microdomains / Q000378:metabolism*; D051379:Mice; D040201:Platelet Membrane Glycoprotein IIb / Q000096:biosynthesis / Q000235:genetics; D011485:Protein Binding; D021122:Protein Subunits / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis
chemical_list: D051928:CD47 Antigen; D005353:Fibronectins; D039564:Integrin alphaV; D039661:Integrin beta3; D016023:Integrins; D040201:Platelet Membrane Glycoprotein IIb; D021122:Protein Subunits; D012333:RNA, Messenger; D015124:8-Bromo Cyclic Adenosine Monophosphate; D002784:Cholesterol; D015232:Dinoprostone
keywords: Cell adhesion; Fibronectin; Integrin; Lipid raft components; Prostaglandin E(2)