title: Role of glycogen synthase kinase-3β and PPAR-γ on epithelial-to-mesenchymal transition in DSS-induced colorectal fibrosis.
abstract: BACKGROUND
  Intestinal fibrosis is characterized by abnormal production and deposition of extracellular matrix (ECM) proteins by activated myofibroblasts. The main progenitor cells of activated myofibroblasts are the fibroblasts and the epithelial cells, the latter through the epithelial-mesenchymal transition (EMT).
  
  
  OBJECTIVE
  To evaluate the action of the new PPAR-γ modulator, GED-0507-34 Levo (GED) on the expression of EMT associated and regulatory proteins such as TGF-β, Smad3, E-cadherin, Snail, ZEB1, β-catenin, and GSK-3β, in a mouse model of DSS-induced intestinal fibrosis.
  
  
  METHODS
  Chronic colitis and fibrosis were induced by oral administration of 2.5% DSS (w/v) for 6 weeks. GW9662 (GW), a selective PPAR-γ inhibitor, was also administered by intraperitoneal injection at the dose of 1 mg/kg/day combined with GED treatment. All drugs were administered at the beginning of the second cycle of DSS (day 12). 65 mice were randomly divided into five groups (H2O as controls n = 10, H2O+GED n = 10, DSS n = 15, DSS+GED n = 15, DSS+GED+GW n = 15). The colon was excised for macroscopic examination and histological and morphometric analyses. The level of expression of molecules involved in EMT and fibrosis, like TGF-β, Smad3, E-cadherin, Snail, ZEB1, β-catenin, GSK-3β and PPAR-γ, was assessed by immunohistochemistry, immunofluorescence, western blot and Real Time PCR.
  
  
  RESULTS
  GED improved the DSS-induced chronic colitis and fibrosis. GED was able to reduce the expression of the main fibrosis markers (α-SMA, collagen I-III and fibronectin) as well as the pivotal pro-fibrotic molecules IL-13, TGF-β and Smad3, while it increased the anti-fibrotic PPAR-γ. All these GED effects were nullified by co-administration of GW with GED. Furthermore, GED was able to normalize the expression levels of E-cadherin and β-catenin and upregulated GSK-3β, that are all known to be involved both in EMT and fibrosis.
  
  
  CONCLUSIONS
  The DSS-induced intestinal fibrosis was improved by the new PPAR-γ modulator GED-0507-34 Levo through the modulation of EMT mediators and pro-fibrotic molecules and through GSK-3β induction.
authors.affiliation: Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy.
authors.forename: Jacopo
authors.initials: J
authors.lastname: Di Gregorio
authors.affiliation: Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Sferra
authors.affiliation: University of Lille, U995, Lille Inflammation Research International Center (LIRIC), F-59000 Lille, France.|IBD, Lille, France.
authors.forename: Silvia
authors.initials: S
authors.lastname: Speca
authors.affiliation: Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Vetuschi
authors.affiliation: IBD, Lille, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Dubuquoy
authors.affiliation: University of Lille, U995, Lille Inflammation Research International Center (LIRIC), F-59000 Lille, France.|IBD, Lille, France.|CHR Lille, Service des Maladies de l'Appareil Digestif et de la Nutrition, Hôpital Claude Huriez, Lille, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Desreumaux
authors.affiliation: Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Pompili
authors.affiliation: Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy.
authors.forename: Loredana
authors.initials: L
authors.lastname: Cristiano
authors.affiliation: Department of Human Anatomy, University of Rome La Sapienza, Rome, Italy.
authors.forename: Eugenio
authors.initials: E
authors.lastname: Gaudio
authors.affiliation: Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Flati
authors.affiliation: Department of Life, Health and Environmental Sciences, Gastroenterology Unit, University of L'Aquila, L'Aquila, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Latella
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003092:Colitis / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology*; D016264:Dextran Sulfate / Q000633:toxicity*; D058750:Epithelial-Mesenchymal Transition; D005355:Fibrosis / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology*; D000071679:Glycogen Synthase Kinase 3 beta / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D047495:PPAR gamma / Q000235:genetics / Q000378:metabolism*; D012007:Rectum / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D015398:Signal Transduction; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism
chemical_list: D047495:PPAR gamma; D016212:Transforming Growth Factor beta; D016264:Dextran Sulfate; D000071679:Glycogen Synthase Kinase 3 beta