title: Hydroxyproline-containing collagen analogs trigger the release and activation of collagen-sequestered proMMP-2 by competition with prodomain-derived peptide P33-42.
abstract: BACKGROUND
  Fibrolytic and profibrotic activities of the matrix metalloproteinases (MMPs)-2 and -9 play a central role in liver fibrosis. Since binding to the extracellular matrix influences the activity of both gelatinases, here the role of fibrillar collagens as the most abundant matrix components in fibrotic tissue was investigated.
  
  
  RESULTS
  In situ zymography and immunohistology showed association of enzymatically inactive prodomain-containing proMMP-2 and proMMP-9 but not of their activated forms to fibrillar collagen structures, which are not substrates of these gelatinases. In solid-phase binding studies with human collagens and collagen fragments, up to 45% of [125I]-labeled proMMP-2 and proMMP-9 but not of active (act)MMP-2 and actMMP-9 were retained by natural collagenous molecules and by synthetic analogs containing repeated Gly-Pro-Hyp triplets (GPO). Surface plasmon resonance yielded binding constants for the interaction of collagen type I (CI) with proMMP-2 and proMMP-9 in a nanomolar range. Values for actMMP-2 and actMMP-9 were 30-40 times higher. Tenfold molar excesses of (GPO)10 reduced the interaction of CI with pro- and actMMP-2 by 22- or 380-fold and resulted in prodomain release accompanied by high enzymatic activation and activity. Pointing to gelatine substrate displacement, higher (GPO)10 concentrations blocked the enzymatic activity. The MMP-2 prodomain-derived collagen-binding domain peptide (P33-42) binds to the collagen-binding domain of MMP-2, thereby preserving enzymatic inactivity. Synthetic P33-42 peptide competed with proMMP-2 binding to CI and prevented (GPO)10-mediated proMMP-2 activation. In contrast to (GPO)10, P33-42 did not activate proMMP-2, making triple helical and hydroxyproline-containing (GPO)10 unique in modulating gelatinase availability and activity.
  
  
  CONCLUSIONS
  These findings suggest novel strategies using collagen analogs for the resolution of liver fibrosis via fibrotic matrix-sequestered gelatinases.
authors.affiliation: Department of Gastroenterology and Hepatology, Charité, Campus Benjamin Franklin, Hindenburgdamm 30, D-12200 Berlin, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Ruehl
authors.affiliation: Department of Gastroenterology and Hepatology, Charité, Campus Benjamin Franklin, Hindenburgdamm 30, D-12200 Berlin, Germany.
authors.forename: Marion
authors.initials: M
authors.lastname: Muche
authors.affiliation: Department of Gastroenterology and Hepatology, Charité, Campus Benjamin Franklin, Hindenburgdamm 30, D-12200 Berlin, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Freise
authors.affiliation: Department of Gastroenterology and Hepatology, Charité, Campus Benjamin Franklin, Hindenburgdamm 30, D-12200 Berlin, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Erben
authors.affiliation: Department of Surgery, Charité Campus Virchow, Augustenburger Platz 1, D-13353 Berlin, Germany.
authors.forename: Ulf
authors.initials: U
authors.lastname: Neumann
authors.affiliation: Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA.
authors.forename: Detlef
authors.initials: D
authors.lastname: Schuppan
authors.affiliation: Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA.
authors.forename: Yury
authors.initials: Y
authors.lastname: Popov
authors.affiliation: Department of Medicine I, Friedrich-Alexander-University Erlangen-Nuernberg, Glücksstrasse 10, D-91054 Erlangen, Germany.
authors.forename: Walburga
authors.initials: W
authors.lastname: Dieterich
authors.affiliation: Department of Gastroenterology and Hepatology, Charité, Campus Benjamin Franklin, Hindenburgdamm 30, D-12200 Berlin, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Zeitz
authors.affiliation: Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK.
authors.forename: Richard W
authors.initials: RW
authors.lastname: Farndale
authors.affiliation: Department of Gastroenterology and Hepatology, Charité, Campus Benjamin Franklin, Hindenburgdamm 30, D-12200 Berlin, Germany.
authors.forename: Rajan
authors.initials: R
authors.lastname: Somasundaram