title: Epidermal growth factor inhibits glycogen synthase kinase-3 (GSK-3) and beta-catenin transcription in cultured ARPE-19 cells.
abstract: BACKGROUND
  Culture of retinal pigment epithelium (RPE) cells might be a future option in the therapy of various degenerative retinal diseases. However, the molecular changes which occur during in vitro expansion of RPE cells during culture are not fully elucidated. The aim of this study was to evaluate molecular changes in the RPE cell line ARPE-19 after stimulation with different growth factors.
  
  
  METHODS
  Cultured ARPE-19 cells were stimulated for 72 hours with rh-EGF, rh-IGF-1, rh-VEGF or rh-bFGF, and transcriptional changes of the differentiation markers cytokeratin 18 and RPE65 and of the key molecules of the wnt pathway, beta-catenin, and glycogen synthase kinase-3 (GSK-3) were evaluated by real time RT-PCR.
  
  
  RESULTS
  We found a significant decrease of cytokeratin 18 and RPE65 transcription after stimulation with rh-EGF (0.47 +/- 0.42 and 0.32 +/- 0.57-fold, respectively; p < 0.05). A significant reduction of beta-catenin and GSK-3 mRNA was found in ARPE-19 cells stimulated with rh-IGF-1 (0.61 +/- 0.25 and 0.52 +/- 0.02-fold, respectively) or rh-EGF (0.55 +/- 0.19 and 0.76 +/- 0.26-fold, respectively). No changes of beta-catenin mRNA were observed after stimulation with rh-VEGF or bFGF.
  
  
  CONCLUSIONS
  Our data suggest an inhibition of the beta-catenin-pathway in ARPE-19 cells by IGF-1 and EGF, suggesting that ARPE-19 cell proliferation is, at least in part, driven by the beta-catenin pathway. Furthermore, induction of proliferation by EGF results in a loss of differentiation markers in these cells. Maintaining the RPE phenotype is still one of the main problems for RPE- transplantation.
authors: Department of Clinical Chemistry, The Ludwig Boltzmann Institut of Retinology and Biomicroscopic Lasersurgery, Rudolfstiftung Hospital, Vienna, Austria.
authors: Walter
authors: W
authors: Krugluger
authors: Stefan
authors: S
authors: Seidel
authors: Kerstin
authors: K
authors: Steindl
authors: Susanne
authors: S
authors: Binder
mesh_terms: D002352:Carrier Proteins / Q000235:genetics; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D005136:Eye Proteins / Q000235:genetics; D038362:Glycogen Synthase Kinase 3 / Q000235:genetics*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D053538:Keratin-18 / Q000235:genetics; D010857:Pigment Epithelium of Eye / Q000187:drug effects* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic / Q000187:drug effects*; D051176:beta Catenin / Q000235:genetics*; D019745:cis-trans-Isomerases; D000099178:Retinoid Isomerohydrolase
chemical_list: D002352:Carrier Proteins; D004815:Epidermal Growth Factor; D005136:Eye Proteins; D038362:Glycogen Synthase Kinase 3; D007334:Insulin-Like Growth Factor I; D053538:Keratin-18; D012333:RNA, Messenger; D011994:Recombinant Proteins; D051176:beta Catenin; D019745:cis-trans-Isomerases; D000099178:Retinoid Isomerohydrolase
references: J Cell Sci. 2003 Apr 1;116(Pt 7):1175-86
references: 12615961
references: Oncogene. 2006 Jan 5;25(1):43-50
references: 16278684
references: Cell. 2003 Jun 13;113(6):685-700
references: 12809600
references: Biochem J. 1994 Oct 1;303 ( Pt 1):21-6
references: 7945242
references: BMC Ophthalmol. 2005 Nov 01;5:25
references: 16262907
references: J Cell Biol. 2005 Jan 3;168(1):29-33
references: 15631989
references: Mol Vis. 2002 Dec 20;8:483-93
references: 12500177
references: Invest Ophthalmol Vis Sci. 2004 Nov;45(11):4151-60
references: 15505069
references: J Cell Sci. 2004 Mar 15;117(Pt 8):1339-50
references: 14996911
references: Biochem J. 1998 Jan 15;329 ( Pt 2):209-23
references: 9425102
references: Exp Eye Res. 2004 Jul;79(1):51-9
references: 15183100
references: Invest Ophthalmol Vis Sci. 2002 Aug;43(8):2782-90
references: 12147616
references: Am J Ophthalmol. 2002 Feb;133(2):215-25
references: 11812425
references: Prog Retin Eye Res. 2004 May;23(3):307-80
references: 15177205
references: Vision Res. 1996 Dec;36(24):4121-5
references: 9068863
references: Invest Ophthalmol Vis Sci. 2002 Sep;43(9):3091-8
references: 12202534
references: J Biol Chem. 1995 Jan 20;270(3):987-90
references: 7836418
references: Curr Eye Res. 1998 Apr;17(4):392-402
references: 9561831
references: Lab Invest. 2004 Oct;84(10 ):1245-58
references: 15273699
references: J Cell Biol. 1994 Dec;127(5):1375-80
references: 7962096
references: Curr Eye Res. 1998 Oct;17(10):962-9
references: 9788298
references: J Cell Sci Suppl. 1993;17:189-95
references: 8144697
references: Invest Ophthalmol Vis Sci. 2002 Feb;43(2):546-55
references: 11818403
references: Invest Ophthalmol Vis Sci. 1999 Aug;40(9):2062-72
references: 10440262
references: Aust N Z J Ophthalmol. 1998 May;26 Suppl 1:S50-2
references: 9685022
references: Nature. 2005 Apr 14;434(7035):843-50
references: 15829953
references: J Cell Physiol. 2002 Apr;191(1):1-16
references: 11920677
references: J Cell Sci. 2002 Nov 15;115(Pt 22):4227-36
references: 12376555
references: Exp Cell Res. 2001 Jun 10;266(2):239-49
references: 11399052
references: Nat Rev Cancer. 2002 Jun;2(6):442-54
references: 12189386