The ratio of transforming growth factor-β1/bone morphogenetic protein-7 in the progression of the epithelial-mesenchymal transition contributes to rat liver fibrosis

Genet Mol Res. 2014 Feb 20;13(1):1005-14. doi: 10.4238/2014.February.20.2.

Abstract

This study was designed to show whether rat liver epithelial cells could undergo epithelial-mesenchymal transition (EMT), thereby directly contributing to liver fibrosis. The role of the ratio of transforming growth factor-β1 (TGF-β1)/bone morphogenetic protein-7 (BMP-7) was evaluated in the progression of EMT or mesenchymal-epithelial transition. Primary rat liver epithelial cells were stimulated with different ratios of TGF-β1/BMP-7 and examined for evidence of transition to a mesenchymal or epithelial phenotype. Liver sections were labeled to detect antigens associated with liver epithelial cells [E-cadherin (E-cad)], EMT [fibroblast-specific protein-1 (FSP-1), vimentin], myofibroblasts [α-smooth muscle actin (α-SMA)], and intracellular signal-transduction mediated by forming liver fibrosis undergo EMT, resulting in the formation of invasive fibroblasts; this process may be driven or impeded by a response to local TGF-β1 or BMP-7. BMP-7 downregulated α-SMA and phosphorylated Smad2/3. Stimulation of cultured cells with TGF-β1 induced the expression of pSmad2/3, FSP-1, and α-SMA. Stimulation of cultured cells with BMP-7 induced the expression of E-cad. We demonstrated that the cells upregulated E-cad release compared with untreated cells, but TGF-β1 was different. We found that the equilibrium of the ratio of TGF-β1/BMP-7 was 1/10. In summary, the mechanism for this process was not determined. Demonstration of the contribution of what the ratio of TGF-β1/BMP-7 induced to EMT to the chronic liver diseases would provide a new basis for understanding pathogenesis and potential treatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism
  • Animals
  • Bone Morphogenetic Protein 7 / metabolism*
  • Cadherins / genetics
  • Cadherins / metabolism
  • Calcium-Binding Proteins / metabolism
  • Cells, Cultured
  • Disease Models, Animal
  • Epithelial Cells / metabolism
  • Epithelial-Mesenchymal Transition*
  • Fibrosis
  • Gene Expression Regulation
  • Liver / metabolism
  • Liver / pathology*
  • Rats
  • Transforming Growth Factor beta1 / metabolism*

Substances

  • Actins
  • Bmp7 protein, rat
  • Bone Morphogenetic Protein 7
  • Cadherins
  • Calcium-Binding Proteins
  • FSP1 protein, rat
  • Tgfb1 protein, rat
  • Transforming Growth Factor beta1
  • smooth muscle actin, rat