Opposing roles of gp130-mediated STAT-3 and ERK-1/ 2 signaling in liver progenitor cell migration and proliferation

Hepatology. 2007 Feb;45(2):486-94. doi: 10.1002/hep.21535.

Abstract

Gp130-mediated IL-6 signaling may play a role in oval cell proliferation in vivo. Levels of IL-6 are elevated in livers of mice treated with a choline-deficient ethionine-supplemented (CDE) diet that induces oval cells, and there is a reduction of oval cells in IL-6 knockout mice. The CDE diet recapitulates characteristics of chronic liver injury in humans. In this study, we determined the impact of IL-6 signaling on oval cell-mediated liver regeneration in vivo. Signaling pathways downstream of gp130 activation were also dissected. Numbers of A6(+ve) liver progenitor oval cells (LPCs) in CDE-treated murine liver were detected by immunohistochemistry and quantified. Levels of oval cell migration and proliferation were compared in CDE-treated mouse strains that depict models of gp130-mediated hyperactive ERK-1/2 signaling (gp130(deltaSTAT)), hyperactive STAT-3 signaling (gp130(Y757F) and Socs-3(-/deltaAlb)) or active ERK-1/2 as well as active STAT-3 signaling (wild-type). The A6(+ve) LPC numbers were increased with IL-6 treatment in vivo. The gp130(Y757F) mice displayed increased A6(+ve) LPCs numbers compared with wild-type and gp130(deltaSTAT) mice. Numbers of A6(+ve) LPCs were also increased in the livers of CDE treated Socs-3(-/deltaAlb) mice compared with their control counterparts. Lastly, inhibition of ERK-1/2 activation in cultured oval cells increased hyper IL-6-induced cell growth. For the first time, we have dissected the gp130-mediated signaling pathways, which influence liver progenitor oval cell proliferation.

Conclusion: Hyperactive STAT-3 signaling results in enhanced oval cell numbers, whereas ERK-1/2 activation suppresses oval cell proliferation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • Cell Movement / physiology*
  • Cell Proliferation*
  • Cytokine Receptor gp130 / physiology*
  • Humans
  • Interleukin-6 / physiology*
  • Liver / cytology
  • Liver / metabolism
  • Liver Regeneration / physiology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mitogen-Activated Protein Kinase 3 / metabolism*
  • STAT3 Transcription Factor / physiology*
  • Signal Transduction / physiology*
  • Stem Cells / physiology*
  • Suppressor of Cytokine Signaling 3 Protein
  • Suppressor of Cytokine Signaling Proteins / metabolism

Substances

  • Il6st protein, mouse
  • Interleukin-6
  • STAT3 Transcription Factor
  • Socs3 protein, mouse
  • Stat3 protein, mouse
  • Suppressor of Cytokine Signaling 3 Protein
  • Suppressor of Cytokine Signaling Proteins
  • Cytokine Receptor gp130
  • Mitogen-Activated Protein Kinase 3