title: Mechanism of macrophage activation by chitin derivatives.
abstract: In order to analyze the detailed mechanisms responsible for macrophage activation by chitin derivatives, resident peritoneal macrophages were prepared and stimulated with chitin, chitosan and low-molecular weight chitosan. Our findings were as follows: (i) chitosan induced apoptosis of peritoneal macrophages, but this did not occur when chitin or water soluble low-molecular weight chitosan were used; (ii) chitosan treatment induced activation markers, such as the major histocompatibility complex (MHC) class I, class II, Fc receptors, transferrin receptor, mannose receptor, Fas, and macrophage inflammatory protein (MIP)-2, whereas chitin and low molecular weight soluble chitosan induced only the expression of MHC class I and II molecules; (iii) apoptosis induced by chitosan was mediated by the Fas signaling pathway, in response to phagocytosis via the mannose receptor. We conclude that since chitosan activates macrophages, this may be the mechanism by which it accelerates wound healing.
authors.affiliation: Laboratory of Veterinary Surgery, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Mori
authors.forename: Masaaki
authors.initials: M
authors.lastname: Murakami
authors.forename: Masahiro
authors.initials: M
authors.lastname: Okumura
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kadosawa
authors.forename: Toshimitsu
authors.initials: T
authors.lastname: Uede
authors.forename: Toru
authors.initials: T
authors.lastname: Fujinaga
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015415:Biomarkers / Q000378:metabolism; D002478:Cells, Cultured; D002686:Chitin / Q000494:pharmacology*; D048271:Chitosan / Q000494:pharmacology*; D005936:Glucans; D037181:Lectins, C-Type / Q000187:drug effects / Q000502:physiology; D008262:Macrophage Activation / Q000187:drug effects*; D017737:Macrophages, Peritoneal; D008351:Mannans / Q000494:pharmacology; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins / Q000187:drug effects / Q000502:physiology; D051379:Mice; D008815:Mice, Inbred Strains; D011134:Polysaccharides / Q000494:pharmacology; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000502:physiology; D015398:Signal Transduction
chemical_list: D015415:Biomarkers; D005936:Glucans; D037181:Lectins, C-Type; D008351:Mannans; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D011134:Polysaccharides; D011956:Receptors, Cell Surface; D002686:Chitin; C008247:laminaran; D048271:Chitosan