title: Crosslinking of CD44 on human osteoblastic cells upregulates ICAM-1 and VCAM-1.
abstract: Cell adhesion of osteoblasts and osteoclastic precursors of hematopoietic origin is a prerequisite for osteoclast maturation. We have investigated the relevance of osteoblast-matrix binding and regulation of adhesion molecules to this process. Human osteoblastic cells highly expressed CD44, a major receptor for hyaluronan present in the surrounding bone matrix. Crosslinking of CD44 on osteoblastic cells with specific antibodies augmented the expression of intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1. Hyaluronan, the major ligand of CD44, also up-regulated ICAM-1 expression. Stimulation of CD44 on osteoblastic cells amplified their adhesion to monocytic cells through ICAM-1 and VCAM-1. These results suggest that such crosstalk among distinct adhesion molecules may be relevant to bone metabolism, including osteoclastogenesis.
authors.affiliation: The First Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi, Kitakyushu 807-8555, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Fujii
authors.forename: Koichi
authors.initials: K
authors.lastname: Fujii
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Nakano
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Tanaka
mesh_terms: D002448:Cell Adhesion; D002478:Cells, Cultured; D003432:Cross-Linking Reagents; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism*; D006820:Hyaluronic Acid / Q000494:pharmacology; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis* / Q000502:physiology; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism*; D015398:Signal Transduction; D020298:U937 Cells; D015854:Up-Regulation; D019010:Vascular Cell Adhesion Molecule-1 / Q000096:biosynthesis* / Q000502:physiology
chemical_list: D003432:Cross-Linking Reagents; D018960:Hyaluronan Receptors; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1; D006820:Hyaluronic Acid