title: Specific heparanase inhibition reverses glucose-induced mesothelial-to-mesenchymal transition.
abstract: BACKGROUND
  Epithelial-to-mesenchymal transition (EMT) of peritoneal mesothelial cells induced by high glucose (HG) levels is a major biological mechanism leading to myofibroblast accumulation in the omentum of patients on peritoneal dialysis (PD). Heparanase (HPSE), an endoglycosidase that cleaves heparan sulfate chains, is involved in the EMT of several cell lines, and may have a major role in this pro-fibrotic process potentially responsible for the failure of dialysis. Its specific inhibition may therefore plausibly minimize this pathological condition.
  
  
  METHODS
  An in vitro study employing several biomolecular strategies was conducted to assess the role of HPSE in the HG-induced mesothelial EMT process, and to measure the effects of its specific inhibition by SST0001, a N-acetylated glycol-split heparin with a strong anti-HPSE activity. Rat mesothelial cells were grown for 6 days in HG (200 mM) culture medium with or without SST0001. Then EMT markers (VIM, α-SMA, TGF-β) and vascular endothelial growth factor (VEGF) (a factor involved in neoangiogenesis) were measured by real-time PCR and immunofluorescence/western blotting. As a functional analysis, trans-epithelial resistance (TER) and permeability to albumin were also measured in our in vitro model using a Millicell-ERS ohmmeter and a spectrophotometer, respectively.
  
  
  RESULTS
  Our results showed that 200 mM of glucose induced a significant gene and protein up-regulation of VEGF and all EMT markers after 6 days of culture. Intriguingly, adding SST0001 on day 3 reversed these biological and cellular effects. HPSE inhibition also restored the normal TER and permeability lost during the HG treatment.
  
  
  CONCLUSIONS
  Taken together, our data confirm that HG can induce EMT of mesothelial cells, and that HPSE plays a central part in this process. Our findings also suggest that pharmacological HPSE inhibition could prove a valuable therapeutic tool for minimizing fibrosis and avoiding a rapid decline in the efficacy of dialysis in patients on PD, though clinical studies and/or trials would be needed to confirm the clinical utility of this treatment.
authors.affiliation: Renal Unit, Department of Medicine, Verona University Hospital, Verona, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Masola
authors.affiliation: Renal Unit, Department of Medicine, Verona University Hospital, Verona, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Granata
authors.affiliation: Renal Unit, Department of Medicine, Verona University Hospital, Verona, Italy.
authors.forename: Gloria
authors.initials: G
authors.lastname: Bellin
authors.affiliation: Nephrology and Dialysis Division, Columbus-Gemelli Hospital, Catholic University School of Medicine, Rome, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Gambaro
authors.affiliation: Department of Biomedical Sciences, University of Padova, Padova, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Onisto
authors.affiliation: Renal Unit, Department of Medicine, Verona University Hospital, Verona, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Rugiu
authors.affiliation: Renal Unit, Department of Medicine, Verona University Hospital, Verona, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Lupo
authors.affiliation: Renal Unit, Department of Medicine, Verona University Hospital, Verona, Italy.
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Zaza
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects*; D004848:Epithelium / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D005355:Fibrosis / Q000503:physiopathology*; D005947:Glucose / Q000494:pharmacology*; D005966:Glucuronidase / Q000037:antagonists & inhibitors*; D006493:Heparin / Q000031:analogs & derivatives* / Q000494:pharmacology; D010537:Peritoneum / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D051381:Rats; D016212:Transforming Growth Factor beta / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D000099175:Heparanase
chemical_list: D005947:Glucose; D005966:Glucuronidase; D006493:Heparin; D016212:Transforming Growth Factor beta; D042461:Vascular Endothelial Growth Factor A; D000099175:Heparanase; C559639:SST 0001
keywords: SST0001; epithelial-to-mesenchymal transition; fibrosis; heparanase; peritoneal dialysis