title: Dynamic study of the transition from hyaluronan- to integrin-mediated adhesion in chondrocytes.
abstract: Membrane-bound hyaluronan mediates the initial adhesive interactions between many cell types and external surfaces. In RCJ-P chondrocytes, such early contacts are mediated through a thick hyaluronidase-sensitive coat. The early adhesion is followed by integrin-mediated interactions and the formation of stable focal adhesions. During this process, the distance between the cell membrane and the surface is reduced from micrometers to few tens of nanometers. The transition from hyaluronan- to integrin-mediated adhesion was studied on glass surfaces by total internal reflection fluorescence microscopy. Hyaluronan-mediated adhesion precedes focal adhesions formation by 2-10 min. After these initial interactions, the pericellular hyaluronan remains sequestered into discrete pockets between the cell and the surface, which are a few hundreds nanometers thick and a few micrometers wide, and are flanked by focal adhesions. The hyaluronan coat facilitates the nucleation of small paxillin-rich contacts, which later mature into focal adhesions. These dynamic studies demonstrate that pericellular hyaluronan mediates initial cell-surface adhesion, and regulates the formation of focal adhesions.
authors.affiliation: Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Miriam
authors.initials: M
authors.lastname: Cohen
authors.forename: Zvi
authors.initials: Z
authors.lastname: Kam
authors.forename: Lia
authors.initials: L
authors.lastname: Addadi
authors.forename: Benjamin
authors.initials: B
authors.lastname: Geiger
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000502:physiology*; D019902:Chondrocytes / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D005109:Extracellular Matrix / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D006820:Hyaluronic Acid / Q000378:metabolism*; D007150:Immunohistochemistry; D016023:Integrins / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D051419:Paxillin; D045663:Quantum Dots; D051381:Rats
chemical_list: D016023:Integrins; D051419:Paxillin; D049452:Green Fluorescent Proteins; D006820:Hyaluronic Acid