A farnesoid x receptor-small heterodimer partner regulatory cascade modulates tissue metalloproteinase inhibitor-1 and matrix metalloprotease expression in hepatic stellate cells and promotes resolution of liver fibrosis

J Pharmacol Exp Ther. 2005 Aug;314(2):584-95. doi: 10.1124/jpet.105.084905. Epub 2005 Apr 28.

Abstract

The farnesoid X receptor (FXR) is expressed by and regulates hepatic stellate cells (HSCs). In the present study, we investigated whether 6-ethyl chenodeoxycholic acid (6-ECDCA or INT-747), a semisynthetic derivative of chenodeoxycholic acid (CDCA), modulates tissue metalloproteinase inhibitor (TIMP)-1 and matrix metalloprotease (MMP)-2 expression/activity in HSCs and in the liver of rats rendered cirrhotic by 4-week administration of CCl(4). Exposure of HSCs to FXR ligands increases small heterodimer partner (SHP) mRNA by 3-fold and reduces basal and thrombin-stimulated expression of alpha1(I)collagen, alpha-smooth muscle actin (alpha-SMA), TIMP-1, and TIMP-2 by approximately 60 to 70%, whereas it increased matrix metalloprotease (MMP)-2 activity by 2-fold. In coimmunoprecipitation, electromobility shift, and transactivation experiments, FXR activation/overexpression caused a SHP-dependent inhibition of JunD binding to its consensus element in the TIMP-1 promoter. Inhibition of TIMP-1 expression by SHP overexpression enhanced the sensitivity of HSCs to proapoptogenic stimuli. Administration of 3 mg/kg 6-ECDCA, but not 15 mg/kg ursodeoxycholic acid, resulted in early (3-5-day) induction of SHP and prevention of early up-regulation of TIMP-1 mRNA induced by CCl(4). In the prevention protocol, 4-week administration of 6-ECDCA reduced alpha1(I)collagen, alpha-SMA, and TIMP-1 mRNA by 60 to 80%, whereas it increased MMP-2 activity by 5-fold. In the resolution protocol, administration of 3 mg/kg 6-ECDCA promoted liver fibrosis resolution and increased the apoptosis of nonparenchyma liver cells. By demonstrating that a FXR-SHP regulatory cascade promotes the development of a quiescent phenotype and increases apoptosis of HSCs, this study establishes that FXR ligands may be beneficial in treatment of liver fibrosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism
  • Animals
  • Apoptosis / physiology
  • Blotting, Western
  • Carbon Tetrachloride Poisoning / pathology
  • Cell Separation
  • DNA-Binding Proteins / physiology*
  • Electrophoretic Mobility Shift Assay
  • Gene Expression Regulation / physiology*
  • Hepatocytes / enzymology
  • Hepatocytes / metabolism*
  • Humans
  • Immunohistochemistry
  • Liver Cirrhosis / chemically induced
  • Liver Cirrhosis / metabolism
  • Liver Cirrhosis / pathology*
  • Matrix Metalloproteinase 2 / biosynthesis
  • Matrix Metalloproteinases / biosynthesis*
  • Plasmids / genetics
  • Proto-Oncogene Proteins c-jun / metabolism
  • Rats
  • Receptors, Cytoplasmic and Nuclear
  • Tissue Inhibitor of Metalloproteinase-1 / biosynthesis*
  • Transcription Factor AP-1 / metabolism
  • Transcription Factors / physiology*

Substances

  • Actins
  • DNA-Binding Proteins
  • Proto-Oncogene Proteins c-jun
  • Receptors, Cytoplasmic and Nuclear
  • Tissue Inhibitor of Metalloproteinase-1
  • Transcription Factor AP-1
  • Transcription Factors
  • farnesoid X-activated receptor
  • Matrix Metalloproteinases
  • Matrix Metalloproteinase 2