Hepatocyte growth factor receptor signaling mediates the anti-fibrotic action of 9-cis-retinoic acid in glomerular mesangial cells

Am J Pathol. 2005 Oct;167(4):947-57. doi: 10.1016/S0002-9440(10)61185-6.

Abstract

Retinoic acid (RA), an active metabolite of vitamin A, plays a critical role in the regulation of cell proliferation, survival, and differentiation. RA action is primarily mediated through its receptors, ligand-dependent transcription factors of the steroid/thyroid/vitamin D nuclear receptor superfamily. Recent studies indicate that administration of RA mitigates progressive kidney disease, underscoring its renoprotective potential. In this study, we investigated the effects of 9-cis-RA on glomerular mesangial cell activation induced by transforming growth factor (TGF)-beta1 using an in vitro cell culture system. In human mesangial cells 9-cis-RA suppressed TGF-beta1-induced alpha-smooth muscle actin, fibronectin, and plasminogen activator inhibitor-1 expression, but it did not significantly affect cell proliferation and survival. Interestingly, 9-cis-RA induced hepatocyte growth factor (HGF) mRNA expression and protein secretion, stimulated HGF promoter activity, and activated c-met receptor phosphorylation. Similar to HGF, 9-cis-RA induced expression of the Smad transcriptional co-repressor TGIF in mesangial cells. Overexpression of exogenous TGIF by transfection or 9-cis-RA treatment suppressed trans-activation of the TGF-beta-responsive promoter. Moreover, conditional ablation of the c-met receptor completely abolished the anti-fibrotic effect of 9-cis-RA and abrogated TGIF induction. Collectively, these results indicate that 9-cis-RA possesses anti-fibrotic ability by antagonizing TGF-beta1 in mesangial cells and that 9-cis-RA activity is likely mediated through a mechanism dependent on HGF/c-met receptor signaling.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Actins / antagonists & inhibitors
  • Adenoviridae / genetics
  • Alitretinoin
  • Animals
  • Blotting, Western
  • Cell Culture Techniques
  • Cell Proliferation / drug effects
  • Cells, Cultured
  • Culture Media, Serum-Free
  • Dose-Response Relationship, Drug
  • Fibronectins / antagonists & inhibitors
  • Fibrosis / drug therapy*
  • Fluorescent Antibody Technique, Indirect
  • Glomerular Mesangium / cytology
  • Glomerular Mesangium / drug effects*
  • Humans
  • Luciferases / metabolism
  • Mice
  • Phosphorylation / drug effects
  • Plasminogen Activator Inhibitor 1 / metabolism
  • Promoter Regions, Genetic / drug effects
  • Proto-Oncogene Proteins c-met / metabolism*
  • RNA, Messenger / drug effects
  • Rats
  • Signal Transduction*
  • Transforming Growth Factor beta / antagonists & inhibitors
  • Transforming Growth Factor beta / pharmacology
  • Transforming Growth Factor beta1
  • Tretinoin / pharmacology*
  • Up-Regulation / drug effects

Substances

  • Actins
  • Culture Media, Serum-Free
  • Fibronectins
  • Plasminogen Activator Inhibitor 1
  • RNA, Messenger
  • TGFB1 protein, human
  • Tgfb1 protein, mouse
  • Tgfb1 protein, rat
  • Transforming Growth Factor beta
  • Transforming Growth Factor beta1
  • smooth muscle actin, rat
  • Alitretinoin
  • Tretinoin
  • Luciferases
  • Proto-Oncogene Proteins c-met