title: Extracellular Matrix Metalloproteinase Inducer (EMMPRIN) promotes lung fibroblast proliferation, survival and differentiation to myofibroblasts.
abstract: BACKGROUND
  Idiopathic pulmonary fibrosis (IPF) is a chronic progressively fatal disease. Extracellular Matrix Metalloproteinase Inducer (EMMPRIN) is a glycosylated transmembrane protein that induces the expression of some matrix metalloproteinase (MMP) in neighboring stromal cells through direct epithelial-stromal interactions. EMMPRIN is highly expressed in type II alveolar epithelial cells at the edges of the fibrotic areas in IPF lung sections. However, the exact role of EMMPRIN in IPF is unknown.
  
  
  METHODS
  To determine if EMMPRIN contributes to lung fibroblast proliferation, resistance to apoptosis, and differentiation to myofibroblasts, normal Human lung fibroblasts (NHLF) transiently transfected with either EMMPRIN/GFP or GFP were treated with TGF- β1 from 0 to 10 ng/ml for 48 h and examined for cell proliferation (thymidine incorporation), apoptosis (FACS analysis and Cell Death Detection ELISA assay), cell migration (Modified Boyden chamber) and differentiation to myofibroblasts using Western blot for α-smooth actin of cell lysates. The effect of EMMPRIN inhibition on NHLF proliferation, apoptosis, migration and differentiation to myofibroblasts after TGF- β1 treatment was examined using EMMPRIN blocking antibody. We examined the mechanism by which EMMPRIN induces its effects on fibroblasts by studying the β-catenin/canonical Wnt signaling pathway using Wnt luciferase reporter assays and Western blot for total and phosphorylated β-catenin.
  
  
  RESULTS
  Human lung fibroblasts overexpressing EMMPRIN had a significant increase in cell proliferation and migration compared to control fibroblasts. Furthermore, EMMPRIN promoted lung fibroblasts resistance to apoptosis. Lung fibroblasts overexpressing EMMPRIN showed a significantly increased expression of α- smooth muscle actin, a marker of differentiation to myofibroblasts compared to control cells. TGF-β1 increased the expression of EMMPRIN in lung fibroblasts in a dose-dependent manner. Attenuation of EMMPRIN expression with the use of an EMMPRIN blocking antibody markedly inhibited TGF-β1 induced proliferation, migration, and differentiation of fibroblasts to myofibroblasts. EMMPRIN overexpression in lung fibroblasts was found to induce an increase in TOPFLASH luciferase reporter activity when compared with control fibroblasts.
  
  
  CONCLUSIONS
  These findings indicate that TGF-β1 induces the release of EMMPRIN that activates β-catenin/canonical Wnt signaling pathway. EMMPRIN overexpression induces an anti-apoptotic and pro-fibrotic phenotype in lung fibroblasts that may contribute to the persistent fibro-proliferative state seen in IPF.
authors.affiliation: Department of Medicine and Research, Veterans Administration Medical Center, Northport, USA.|Department of Medicine, Stony Brook Medicine, Stony Brook, New York, USA.|Division of Pulmonary, Critical Care and Sleep Medicine, Stony Brook University Medical Center, Stony Brook, NY, 11794-8172, USA.
authors.forename: Nadia A
authors.initials: NA
authors.lastname: Hasaneen
authors.affiliation: Department of Medicine, Stony Brook Medicine, Stony Brook, New York, USA.
authors.forename: Jian
authors.initials: J
authors.lastname: Cao
authors.affiliation: Department of Medicine, Stony Brook Medicine, Stony Brook, New York, USA.
authors.forename: Ashleigh
authors.initials: A
authors.lastname: Pulkoski-Gross
authors.affiliation: Department of Medicine and Research, Veterans Administration Medical Center, Northport, USA.|Department of Medicine, Stony Brook Medicine, Stony Brook, New York, USA.
authors.forename: Stanley
authors.initials: S
authors.lastname: Zucker
authors.affiliation: Department of Medicine and Research, Veterans Administration Medical Center, Northport, USA. Hussein.Foda@va.gov.|Department of Medicine, Stony Brook Medicine, Stony Brook, New York, USA. Hussein.Foda@va.gov.|Division of Pulmonary, Critical Care and Sleep Medicine, Stony Brook University Medical Center, Stony Brook, NY, 11794-8172, USA. Hussein.Foda@va.gov.
authors.forename: Hussein D
authors.initials: HD
authors.lastname: Foda
mesh_terms: D051926:Basigin / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D049109:Cell Proliferation / Q000502:physiology; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D005347:Fibroblasts / Q000166:cytology* / Q000502:physiology*; D006801:Humans; D008168:Lung / Q000166:cytology* / Q000502:physiology*; D058628:Myofibroblasts / Q000166:cytology / Q000502:physiology
chemical_list: D051926:Basigin