title: The upregulation of angiogenic gene expression in cultured retinal pigment epithelial cells grown on type I collagen.
abstract: OBJECTIVE
  Increases in matrix proteins, such as type I collagen and fibronectin, are observed with aging in the retinal pigment epithelium (RPE) basement membrane. However, little is known about altered gene expression profiles of RPE associated with increases in matrix proteins. We investigated changes in gene expression profiles of a human RPE cell line (ARPE-19) cultured on type I collagen.
  
  
  METHODS
  Visually confluent ARPE-19 cells were grown on either Matrigel (M group) or type I collagen (C group) without serum over 3 days. Total RNA was extracted and reverse transcribed. Gene expression profiles in both groups were compared using microarray analyses. Several angiogenic genes including integrin alpha V, integrin alpha 2, integrin beta 1, integrin beta 3, VEGF-A, VEGF-B, and VEGF-C were subjected to quantitative analyses using real-time PCR.
  
  
  RESULTS
  Out of 192 genes examined, angiogenesis-related genes (17.7%) and extracellular matrix-related genes (30.2%) were expressed highly (with more than 1.5-fold difference) in the C group when compared with the M group. In real-time PCR analyses, all VEGF and integrin family genes examined were expressed more in the C group than in the M group.
  
  
  CONCLUSIONS
  Type I collagen likely causes an upregulation in a number of angiogenic gene expression patterns as seen in RPE in vitro experiments.
authors.affiliation: Department of Surgery, Division of Ophthalmology, Kobe University Graduate School of Medicine, Chuo-ku, Kobe, Japan.
authors.forename: Hisanori
authors.initials: H
authors.lastname: Imai
authors.forename: Shigeru
authors.initials: S
authors.lastname: Honda
authors.forename: Naoshi
authors.initials: N
authors.lastname: Kondo
authors.forename: Kazuki
authors.initials: K
authors.lastname: Ishibashi
authors.forename: Yasutomo
authors.initials: Y
authors.lastname: Tsukahara
authors.forename: Akira
authors.initials: A
authors.lastname: Negi
mesh_terms: D002460:Cell Line; D024042:Collagen Type I / Q000494:pharmacology*; D003199:Computer Systems; D003470:Culture Media / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects*; D020869:Gene Expression Profiling; D006801:Humans; D007150:Immunohistochemistry; D038982:Integrin alpha2beta1 / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D010857:Pigment Epithelium of Eye / Q000166:cytology / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D015854:Up-Regulation / Q000187:drug effects*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D024042:Collagen Type I; D003470:Culture Media; D038982:Integrin alpha2beta1; D042461:Vascular Endothelial Growth Factor A