title: Epitope-defined monoclonal antibodies against multiplexin collagens demonstrate that type XV and XVIII collagens are expressed in specialized basement membranes.
abstract: Type XV and type XVIII collagens are classified as part of multiplexin collagen superfamily and their C-terminal parts, endostatin and restin, respectively, have been shown to be anti-angiogenic in vivo and in vitro. The alpha1(XV) and alpha1(XVIII) collagen chains are reported to be localized mainly in the basement membrane zone, but their distributions in blood vessels and nonvascular tissues have yet to be thoroughly clarified. In the present study, we raised monoclonal antibodies against synthetic peptides of human alpha1(XV) and alpha1(XVIII) chains and used them for extensive investigation of the distribution of these chains. We came to the conclusion that nonvascular BMs contain mainly one of two types: subepithelial basement membranes that contained type XVIII in general, or skeletal and cardiac muscles that harbored mainly type XV. But basement membranes surrounding smooth muscle cells in vascular tissues contained one or both of them, depending on their locations. Interestingly, continuous capillaries contained both type XV and type XVIII collagens in their basement membranes; however, fenestrated or specialized capillaries such as glomeruli, liver sinusoids, lung alveoli, and splenic sinusoids expressed only type XVIII in their basement membranes, lacking type XV. This observation could imply that different functions of basement membranes in various tissues and organs use different mechanisms for the endogenous control of angiogenesis.
authors.affiliation: Division of Molecular and Cell Biology, Shigei Medical Research Institute, Okayama, Japan.
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Tomono
authors.forename: Ichiro
authors.initials: I
authors.lastname: Naito
authors.forename: Kaori
authors.initials: K
authors.lastname: Ando
authors.forename: Tomoko
authors.initials: T
authors.lastname: Yonezawa
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Sado
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hirakawa
authors.forename: Jirô
authors.initials: J
authors.lastname: Arata
authors.forename: Tohru
authors.initials: T
authors.lastname: Okigaki
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Ninomiya
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D001485:Basement Membrane / Q000378:metabolism; D002196:Capillaries / Q000378:metabolism* / Q000648:ultrastructure; D003094:Collagen / Q000276:immunology / Q000378:metabolism*; D043170:Collagen Type XVIII; D004847:Epithelial Cells / Q000378:metabolism* / Q000648:ultrastructure; D000939:Epitopes / Q000276:immunology; D006801:Humans; D007150:Immunohistochemistry; D009132:Muscles / Q000378:metabolism* / Q000648:ultrastructure; D014018:Tissue Distribution
chemical_list: D000911:Antibodies, Monoclonal; C085811:COL15A1 protein, human; D043170:Collagen Type XVIII; D000939:Epitopes; D003094:Collagen