Plasmin-mediated proteolysis is required for hepatocyte growth factor activation during liver repair

J Biol Chem. 2009 May 8;284(19):12917-23. doi: 10.1074/jbc.M807313200. Epub 2009 Mar 13.

Abstract

The physiological relevance of the activation of hepatocyte growth factor (Hgf) by the plasminogen (Plg) system of proteases and its contribution to tissue repair are largely undefined. Here, we investigated whether the defective liver repair in mice lacking Plg is due to impaired activation of Hgf. Loss of Plg in vivo suppressed Hgf activation and signaling through its Met tyrosine kinase receptor. Without Plg, hepatocytes were unresponsive to Hgf-induced proliferation and migration, with a more pronounced impairment in hepatocyte movement within the hepatic environment. Most notably, circumventing the defect in proteolytic activation of Hgf by the downstream expression of an activated Met receptor corrected the functional deficits and improved liver repair in Plg-deficient mice. These findings support a fibrinolysis-unrelated role for Plg in modulating cell proliferation and migration by activation of Hgf.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Blotting, Western
  • Carbon Tetrachloride / metabolism
  • Cell Movement / physiology
  • Cell Proliferation
  • Cells, Cultured
  • Chemical and Drug Induced Liver Injury / metabolism*
  • Chemical and Drug Induced Liver Injury / pathology
  • Fibrinolysin / physiology*
  • Hepatocyte Growth Factor / genetics
  • Hepatocyte Growth Factor / metabolism*
  • Hepatocytes / cytology
  • Hepatocytes / metabolism
  • Liver / physiology*
  • Liver Regeneration / physiology*
  • Mice
  • Mice, Knockout
  • Plasminogen / physiology
  • Proto-Oncogene Proteins c-met / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Wound Healing / physiology*

Substances

  • RNA, Messenger
  • Hepatocyte Growth Factor
  • Plasminogen
  • Carbon Tetrachloride
  • Proto-Oncogene Proteins c-met
  • Fibrinolysin