title: Epidermal growth factor: the driving force in initiation of RPE cell proliferation.
abstract: BACKGROUND
  To analyze whether epidermal growth factor (EGF) exerts regulatory effects on proliferation and differentiation in ARPE19 cells after different incubation periods (24 vs. 48 h) for obtaining ideal conditions for feasible rejuvenation and autologous transplantation of retinal pigment epithelial cells (RPE cells).
  
  
  METHODS
  To evaluate gene expression patterns of RPE-specific differentiation and proliferation markers as well as transcriptional and translational changes of beta-catenin (ß-catenin)-signaling markers by fluorescence activated cell sorting (FACS) and reverse transcription - polymerase chain reaction (RT-PCR) after 24 h of EGF treatment.
  
  
  RESULTS
  After 24 h of EGF treatment, a significant decrease of retinal pigment epithelium-specific protein 65 (RPE 65), cellular retinaldehyde-binding protein (CRALBP) and cytokeratin 18 in ARPE-19 cells was scaled. In addition, an increase of cyclin D1 expression and a significant decrease of glycogen synthase kinase-3beta (GSK-3ß) and beta-catenin (ß-catenin) were equally observed after 24 and 48 h of EGF treatment. Cell-cycle studies revealed an increase of ARPE cells in S-G2/M phase after 24 h of EGF treatment.
  
  
  CONCLUSIONS
  Our data demonstrate the induction of proliferation and upregulation of the ß-catenin signaling pathway by EGF even after 24 h of incubation. As ideal cell culture conditions are essential for maintaining RPE-specific phenotypes, short incubation times enhance RPE cell quality for feasible rejuvenation and subsequent autologous transplantation of RPE cells.
authors.affiliation: Department of Ophthalmology, Ludwig Boltzmann Institute for Retinology and Biomicroscopic Lasersurgery, Rudolf Foundation Clinic, Juchgasse 25, 1030 Vienna, Austria. kerstin.steindl@aon.at
authors.forename: Kerstin
authors.initials: K
authors.lastname: Steindl-Kuscher
authors.forename: Michael E
authors.initials: ME
authors.lastname: Boulton
authors.forename: Paulina
authors.initials: P
authors.lastname: Haas
authors.forename: Astrid
authors.initials: A
authors.lastname: Dossenbach-Glaninger
authors.forename: Hans
authors.initials: H
authors.lastname: Feichtinger
authors.forename: Susanne
authors.initials: S
authors.lastname: Binder
mesh_terms: D015415:Biomarkers; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002453:Cell Cycle; D002454:Cell Differentiation / Q000187:drug effects*; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects*; D017931:DNA Primers / Q000737:chemistry; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D038362:Glycogen Synthase Kinase 3 / Q000235:genetics / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D053538:Keratin-18 / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D055213:Retinal Pigment Epithelium / Q000166:cytology* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051176:beta Catenin / Q000378:metabolism; D019745:cis-trans-Isomerases; D000099178:Retinoid Isomerohydrolase
chemical_list: D015415:Biomarkers; D002352:Carrier Proteins; D017931:DNA Primers; D004815:Epidermal Growth Factor; D005136:Eye Proteins; D038362:Glycogen Synthase Kinase 3; D000071679:Glycogen Synthase Kinase 3 beta; D053538:Keratin-18; D012333:RNA, Messenger; D051176:beta Catenin; D019745:cis-trans-Isomerases; D000099178:Retinoid Isomerohydrolase; C020932:11-cis-retinal-binding protein; C495270:CTNNB1 protein, human; C000605506:GSK3B protein, human