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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2005-9-20
pubmed:abstractText
The nuclear receptors farnesoid X receptor (FXR) and peroxisome proliferator-activated receptor (PPAR)gamma exert counter-regulatory effects on hepatic stellate cells (HSCs) and protect against liver fibrosis development in rodents. Here, we investigated whether FXR ligands regulate PPARgamma expression in HSCs and models of liver fibrosis induced in rats by porcine serum and carbon tetrachloride administration and bile duct ligation. Our results demonstrate that HSCs trans-differentiation associated with suppression of PPARgamma mRNA expression, whereas FXR mRNA was unchanged. Exposure of cells to natural and synthetic ligands of FXR, including 6-ethyl chenodeoxycholic acid (6-ECDCA), a synthetic derivative of chenodeoxycholic acid, reversed this effect and increased PPARgamma mRNA by approximately 40-fold. Submaximally effective concentrations of FXR and PPARgamma ligands were additive in inhibiting alpha1(I) collagen mRNA accumulation induced by transforming growth factor (TGF)beta1. Administration of 6-ECDCA in rats rendered cirrhotic by porcine serum and carbon tetrachloride administration or bile duct ligation reverted down-regulation of PPARgamma mRNA expression in HSCs. Cotreatment with 6-ECDCA potentiates the antifibrotic activity of rosiglitazone, a PPARgamma ligand, in the porcine serum model as measured by morphometric analysis of liver collagen content, hydroxyproline, and liver expression of alpha1(I) collagen mRNA, alpha-smooth muscle actin, fibronectin, TGFbeta1, and tissue inhibitor of metalloprotease 1 and 2, whereas it enhanced the expression of PPARgamma and uncoupling protein 2, a PPARgamma-regulated gene, by 2-fold. In conclusion, by using an in vitro and in vivo approach, we demonstrated that FXR ligands up-regulate PPARgamma mRNA in HSCs and in rodent models of liver fibrosis. A FXR-PPARgamma cascade exerts counter-regulatory effects in HSCs activation.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0022-3565
pubmed:author
pubmed:issnType
Print
pubmed:volume
315
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
58-68
pubmed:dateRevised
2009-4-27
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Cross-talk between farnesoid-X-receptor (FXR) and peroxisome proliferator-activated receptor gamma contributes to the antifibrotic activity of FXR ligands in rodent models of liver cirrhosis.
pubmed:affiliation
Dipartimento de Medicina Clinica e Sperimentale, Università degli Studi di Perugia, Italy. fiorucci@unipg.it
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't