title: Calcium citrate improves the epithelial-to-mesenchymal transition induced by acidosis in proximal tubular cells.
abstract: BACKGROUND
  Epithelial-to-mesenchymal transition (EMT) is a key event in renal fibrosis. The aims of the study were to evaluate acidosis induced EMT, transforming-growth-factor (TGF) β1 role and citrate effect on it.
  
  
  METHODS
  HK2 cells (ATCC 2290) were cultured in DMEM/HAM F12 medium, pH 7.4. At 80% confluence, after 24 hr under serum free conditions, cells were distributed in three groups (24 hours): A) Control: pH 7.4, B) Acidosis: pH 7.0 and C) Calcium citrate (0.2 mmol/L) + pH 7.0. Change (Δ) of intracellular calcium concentration, basal and after Angiotensin II (10-6M) exposition, were measured to evaluate cellular performance. EMT was evaluated by the expression of α-smooth muscle actin (α-SMA) and E-cadherin by immunocytochemistry and/or Western blot. TGF-β1 secretion was determined by ELISA in cell supernatant.
  
  
  RESULTS
  At pH 7.0 HK2 cells significantly reduced E-cadherin and increased α-SMA expression (EMT). Supernatant TGF-β1 levels were higher than in control group. Calcium citrate decreased acidosis induced EMT and improved cells performance, without reduction of TGF-β production.
  
  
  CONCLUSIONS
  Acidosis induces EMT and secretion of TGF-β1 in tubular proximal cells in culture and citrate improves cellular performance and ameliorates acidosis induced EMT.
authors: Dpto Fisiopatología, Facultad de Medicina, Universidad de la República, Uruguay.
authors: Maria José Rodriguez
authors: MJ
authors: Cabalgante
authors: Liliana
authors: L
authors: Gadola
authors: Leonella
authors: L
authors: Luzardo
authors: María
authors: M
authors: Márquez
authors: José
authors: J
authors: Boggia
authors: Mirian Aparecida
authors: MA
authors: Boim
mesh_terms: D000141:Acidosis, Renal Tubular / Q000188:drug therapy* / Q000473:pathology*; D019355:Calcium Citrate / Q000494:pharmacology* / Q000627:therapeutic use*; D002478:Cells, Cultured; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects*; D006801:Humans; D007687:Kidney Tubules, Proximal / Q000166:cytology* / Q000187:drug effects*
chemical_list: D019355:Calcium Citrate