title: [All-trans-retinol (atR) inhibits expression of the metalloproteinase stromelysin in retinal pigment epithelium (RPE)].
abstract: BACKGROUND
  The pathobiology in proliferative vitreoretinopathy (PVR) is complex. The mechanism of the release of retinal cells from their cellular bond is unknown. The metalloproteinase stromelysin cleaves proteins of the extracellular matrix (ECM). This may liberate retinal cells. The expression of stromelysin in human RPE cells has been demonstrated. Here, stromelysin gene expression under all-trans-Retinal (atR) was investigated.
  
  
  METHODS
  Human RPE-cells were used from passage 2 to 5. The expression of the human stromelysin gene was determined by reverse transcriptase-polymerase chain reaction using specific oligonucleotides. RPE-cells were incubated with 162 nmol/l tetraphorbolester (TPA) alone or simultaneous with 1 mumol/l atR.
  
  
  RESULTS
  TPA increased the expression of stromelysin in RPE cells. Incubation with TPA and atR lowered this increase. The decrease of expression was calculated semiquantitatively.
  
  
  CONCLUSIONS
  The expression of stromelysin in RPE cells is lowered after incubation with 1 mumol/l atR. The dedifferentiation of RPE-cells may decrease intracellular atR levels. This could turn an inhibition of stromelysin gene expression to an increase. This may then release retinal cells from their cellular bond and therefore be one of the initial steps in the development of PVR.
authors.affiliation: Augenklinik der Ludwig Maximilians Universität München. cschoenf@ak-i.med.uni-muenchen.de
authors.forename: C L
authors.initials: CL
authors.lastname: Schönfeld
mesh_terms: D002478:Cells, Cultured; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D019278:Matrix Metalloproteinase 3 / Q000235:genetics; D061965:Matrix Metalloproteinase Inhibitors; D010857:Pigment Epithelium of Eye / Q000187:drug effects* / Q000201:enzymology; D014212:Tretinoin / Q000494:pharmacology*; D018630:Vitreoretinopathy, Proliferative / Q000201:enzymology
chemical_list: D061965:Matrix Metalloproteinase Inhibitors; D014212:Tretinoin; D019278:Matrix Metalloproteinase 3