title: Effects of coagulation on the autofluorescence pattern of ARPE-19 cells: an in vitro study.
abstract: OBJECTIVE
  Changes in fundus autofluorescence (AF) are observed in various retinal disorders. Lipofuscin accumulation within the retinal pigment epithelium (RPE) is a source of fundus AF (FAF); however, the causes of short-term increases in FAF observed in inflammatory conditions or after laser treatment are unknown. Here, we describe an RPE cell culture model that is useful for investigations of FAF.
  
  
  METHODS
  ARPE-19 cells were cultured in 2-well chamber slides. Cells were exposed to isolated rabbit photoreceptor outer segments (POS) to mimic in vivo phagocytic activity. The AF of RPE cells exposed to POS was measured before and after focal coagulation of the cultures. AF was measured over a period of 4 weeks. Cell lysates were examined by two-dimensional (2D) gel electrophoresis and mass spectrometry analysis.
  
  
  RESULTS
  The exposure of ARPE cells to POS did not lead to increased AF; however, after coagulation, cells exposed to POS showed a statistically significant increase in AF (p < 0.05). 2D electrophoresis of the cell lysates revealed changes in 3 proteins. One of these proteins, identified by mass spectrometry as ezrin-radixin-moesin-binding phosphoprotein 50, was reduced in the coagulated cell population.
  
  
  CONCLUSIONS
  We have established an in vitro model of RPE cells in culture that can be used to evaluate the development of AF and changes in cellular proteins that accompany laser photocoagulation.
authors.affiliation: Department of Ophthalmology, RWTH Aachen University, Aachen, Germany. akoutsonas@ukaachen.de
authors.forename: Antonis
authors.initials: A
authors.lastname: Koutsonas
authors.forename: Doerthe
authors.initials: D
authors.lastname: Carstesen
authors.forename: Corinna
authors.initials: C
authors.lastname: Henkel
authors.forename: Peter
authors.initials: P
authors.lastname: Walter
authors.forename: Gabriele
authors.initials: G
authors.lastname: Thumann
authors.forename: Andreas W A
authors.initials: AW
authors.lastname: Weinberger
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D005453:Fluorescence; D017075:Laser Coagulation; D008954:Models, Biological; D011817:Rabbits; D055213:Retinal Pigment Epithelium / Q000378:metabolism*; D012374:Rod Cell Outer Segment / Q000502:physiology / Q000528:radiation effects*