title: Saccharides mediate the attachment of rat macrophages to bone in vitro.
abstract: Macrophages (M phi) are multipotential cells capable of giving rise to osteoclasts and of resorbing bone. Since both of these processes are ultimately dependent upon the attachment of cells to a mineralized bone surface, we have examined in this study the mechanism by which such attachment is achieved. The data show that elicited rat peritoneal M phi bind to bone in a temperature-dependent and -saturable manner with half-maximal attachment occurring within 10 min at 37 degrees C and reaching a plateau by approximately 60 min. The kinetics of binding are essentially the same whether devitalized bone particles or viable calvaria are used as a substrate. The attachment of M phi to bone is inhibited by some sugars (e.g., N-acetyl-galactosamine, thiogalactoside, beta-lactose), fetuin and asialofetuin, and by pretreating the bone with periodate. Binding is also significantly reduced when M phi are preincubated with tunicamycin and swainsonine at nontoxic concentrations sufficient to inhibit or alter glycosylation. On the other hand, exposing the cells to neuraminidase increases the capacity of M phi to bind to bone. Collectively, our observations indicate that the attachment of M phi to bone is a highly regulated process and is mediated, at least in part, by saccharides located on both the cell and the bone surface.
mesh_terms: D000818:Animals; D001665:Binding Sites / Q000187:drug effects; D001667:Binding, Competitive; D001862:Bone Resorption; D001842:Bone and Bones / Q000378:metabolism*; D050260:Carbohydrate Metabolism; D002241:Carbohydrates / Q000502:physiology*; D002448:Cell Adhesion; D007700:Kinetics; D007785:Lactose / Q000494:pharmacology; D008264:Macrophages / Q000378:metabolism*; D008297:Male; D009844:Oligosaccharides / Q000378:metabolism; D010504:Periodic Acid / Q000494:pharmacology; D051381:Rats; D012794:Sialic Acids / Q000494:pharmacology; D013696:Temperature; D013862:Thiogalactosides / Q000494:pharmacology
chemical_list: D002241:Carbohydrates; D009844:Oligosaccharides; D012794:Sialic Acids; D013862:Thiogalactosides; D010504:Periodic Acid; C009288:metaperiodate; D007785:Lactose