title: Retinal pigment epithelial cell behavior is modulated by alterations in focal cell-substrate contacts.
abstract: OBJECTIVE
  To investigate how the cellular behavior of cultured retinal pigment epithelial (RPE) cells was affected by the manipulation of early focal contact.
  
  
  METHODS
  To manipulate early focal contact, a reduced focal cell-substrate contact area on the micropatterned surfaces was implemented by microfabrication with polydimethylsiloxane (PDMS). The micropatterned PDMS surfaces had a circular pillar with a diameter of 5 microm. The human retinal pigment epithelial cell line, ARPE-19, was seeded onto the fibronectin-coated PDMS surfaces. Cell adhesion, growth, cell cycle, morphology, and interleukin-6 (IL-6) expression were observed for 3 weeks.
  
  
  RESULTS
  The fluorescent images of localized vinculin and actin stress fibers appeared to be more prominent on smooth PDMS surfaces. Although there was no significant effect on cell adhesion, a statistically significant inhibition of cell cycle progression was observed for micropatterned PDMS surfaces. Similarly, micropatterned surfaces showed significantly less cell growth than that of smooth surfaces. Cultures over a period of 3 weeks showed a distinct cell-cell phenotype discrepancy. Furthermore, IL-6 mRNA and secreted protein induced by IL-1beta in ARPE-19 were downregulated on micropatterned PDMS surfaces.
  
  
  CONCLUSIONS
  Disturbed focal contact in ARPE-19 cells grown on micropatterned surfaces altered cell cycle, growth, morphology, and the expression of IL-6 in vitro.
authors.affiliation: School of Electrical Engineering and Computer Science, Seoul National University, Korea.
authors.forename: Jung-Min
authors.initials: JM
authors.lastname: Lim
authors.forename: Sangwon
authors.initials: S
authors.lastname: Byun
authors.forename: Seok
authors.initials: S
authors.lastname: Chung
authors.forename: Tai Hyun
authors.initials: TH
authors.lastname: Park
authors.forename: Jong-Mo
authors.initials: JM
authors.lastname: Seo
authors.forename: Choun-Ki
authors.initials: CK
authors.lastname: Joo
authors.forename: Hum
authors.initials: H
authors.lastname: Chung
authors.forename: Dong-Il
authors.initials: DI
authors.lastname: Cho
mesh_terms: D000199:Actins / Q000378:metabolism; D002448:Cell Adhesion / Q000502:physiology*; D002453:Cell Cycle / Q000502:physiology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D004129:Dimethylpolysiloxanes; D004797:Enzyme-Linked Immunosorbent Assay; D005353:Fibronectins; D006801:Humans; D007150:Immunohistochemistry; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D008562:Membrane Glycoproteins; D010857:Pigment Epithelium of Eye / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012828:Silicones; D016596:Vinculin / Q000378:metabolism
chemical_list: D000199:Actins; D004129:Dimethylpolysiloxanes; D005353:Fibronectins; D015850:Interleukin-6; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D012828:Silicones; C048022:substrate adhesion molecules; D016596:Vinculin; C013830:baysilon