title: Production of type VI collagen by human macrophages: a new dimension in macrophage functional heterogeneity.
abstract: Macrophages derived from human blood monocytes perform many tasks related to tissue injury and repair. The main effect of macrophages on the extracellular matrix is considered to be destructive in nature, because macrophages secrete metalloproteinases and ingest foreign material as part of the remodeling process that occurs in wound healing and other pathological conditions. However, macrophages also contribute to the extracellular matrix and hence to tissue stabilization both indirectly, by inducing other cells to proliferate and to release matrix components, and directly, by secreting components of the extracellular matrix such as fibronectin and type VIII collagen, as we have recently shown. We now report that monocytes and macrophages express virtually all known collagen and collagen-related mRNAs. Furthermore, macrophages secrete type VI collagen protein abundantly, depending upon their mode of activation, stage of differentiation, and cell density. The primary function of type VI collagen secreted by macrophages appears to be modulation of cell-cell and cell-matrix interactions. We suggest that the production of type VI collagen is a marker for a nondestructive, matrix-conserving macrophage phenotype that could profoundly influence physiological and pathophysiological conditions in vivo.
authors.affiliation: Leibniz Institute of Arteriosclerosis Research, Münster, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Schnoor
authors.forename: Paul
authors.initials: P
authors.lastname: Cullen
authors.forename: Julia
authors.initials: J
authors.lastname: Lorkowski
authors.forename: Katrin
authors.initials: K
authors.lastname: Stolle
authors.forename: Horst
authors.initials: H
authors.lastname: Robenek
authors.forename: David
authors.initials: D
authors.lastname: Troyer
authors.forename: Jürgen
authors.initials: J
authors.lastname: Rauterberg
authors.forename: Stefan
authors.initials: S
authors.lastname: Lorkowski
mesh_terms: D000595:Amino Acid Sequence; D002460:Cell Line; D002478:Cells, Cultured; D003094:Collagen / Q000096:biosynthesis* / Q000097:blood / Q000235:genetics; D024142:Collagen Type VI / Q000096:biosynthesis* / Q000097:blood / Q000235:genetics; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D008264:Macrophages / Q000378:metabolism* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D009000:Monocytes / Q000378:metabolism*; D032389:Myocytes, Smooth Muscle / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism
chemical_list: D024142:Collagen Type VI; D016326:Extracellular Matrix Proteins; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D003094:Collagen