title: 20-Hydroxyecdysone attenuates TGF-β1-induced renal cellular fibrosis in proximal tubule cells.
abstract: Renal fibrosis progresses to end stage of diabetes kidney disease, which causes irreversible progressive proximal tubular injury. In a previous study, 20-hydroxyecdysterone (20-HE), a phytoecdysteroid, attenuated renal injury in diabetes models. However, the fibrosis regulatory role remains to be investigated.
  
  
  METHODS
  The proximal tubular epithelial cells (designated as HK-2) were treated for 48 h with TGF-β1 (5 ng/ml) in different concentrations of 20-HE (0 to 500 nM/ml) in the last 24 h of culture. The extracellular fibronectin was measured by ELISA assay. Western blot and immunofluorescence were used to evaluate the expression of TGF-β1/Smads transducer (including Smad2/3, 4, and 7), epithelial and mesenchymal markers (e.g. E-cadherin and α-smooth muscle actin) and Snail (transcriptional regulators for EMT).
  
  
  RESULTS
  20-HE reverses TGF-β1-induced increase in fibronectin (both intracellular and extracellular fibronectin). Simultaneously, 20-HE reverses TGF-β1-induced down-regulation of Smad7. In addition, 20-HE significantly attenuates TGF-β1-induced upregulation of Smad2/3 and pSmad2/3, and downregulation of E-Cadherin. Moreover, 20-HE dramatically suppresses TGF-β1-induced increases in the expression of Snail.
  
  
  CONCLUSIONS
  We propose that 20-HE is a potential fibrosis antagonist for renal proximal tubule cells. 20-HE might act through suppressing post-receptor signaling of TGF-β1 and restoring tubule epithelial character by blocking the expression of Snail.
authors.affiliation: Department of Graduate Institute of Biomedical Science, Chung Hwa University of Medical Technology, Tainan, Taiwan.
authors.forename: Tsung-Jen
authors.initials: TJ
authors.lastname: Hung
authors.forename: Wei-Ming
authors.initials: WM
authors.lastname: Chen
authors.forename: Shu-Fen
authors.initials: SF
authors.lastname: Liu
authors.forename: Tung-Nan
authors.initials: TN
authors.lastname: Liao
authors.forename: Tao-Chen
authors.initials: TC
authors.lastname: Lee
authors.forename: Lea-Yea
authors.initials: LY
authors.lastname: Chuang
authors.forename: Jinn-Yuh
authors.initials: JY
authors.lastname: Guh
authors.forename: Chien-Ya
authors.initials: CY
authors.lastname: Hung
authors.forename: Yu-Ju
authors.initials: YJ
authors.lastname: Hung
authors.forename: Po-Yi
authors.initials: PY
authors.lastname: Chen
authors.forename: Pei-Fang
authors.initials: PF
authors.lastname: Hsieh
authors.forename: Yu-Lin
authors.initials: YL
authors.lastname: Yang
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D002460:Cell Line; D003928:Diabetic Nephropathies / Q000517:prevention & control; D015536:Down-Regulation / Q000187:drug effects*; D004441:Ecdysterone / Q000494:pharmacology* / Q000627:therapeutic use; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects; D005353:Fibronectins / Q000378:metabolism; D005355:Fibrosis; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D007687:Kidney Tubules, Proximal / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D058990:Molecular Targeted Therapy; D009994:Osmolar Concentration; D010840:Phytosterols / Q000494:pharmacology / Q000627:therapeutic use; D020011:Protective Agents / Q000494:pharmacology* / Q000627:therapeutic use; D015398:Signal Transduction / Q000187:drug effects*; D051785:Smad Proteins / Q000378:metabolism; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors / Q000378:metabolism; D053773:Transforming Growth Factor beta1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D015415:Biomarkers; D005353:Fibronectins; D007004:Hypoglycemic Agents; D010840:Phytosterols; D020011:Protective Agents; D051785:Smad Proteins; D000071250:Snail Family Transcription Factors; C508960:TGFB1 protein, human; D014157:Transcription Factors; D053773:Transforming Growth Factor beta1; D004441:Ecdysterone