title: Indocyanine green increases light-induced oxidative stress, senescence, and matrix metalloproteinases 1 and 3 in human RPE cells.
abstract: OBJECTIVE
  Indocyanine green (ICG) is a commonly used vital dye for macular surgery. Recent reports implicate that its use might be associated with less favourable results regarding postoperative visual outcome and damage of retinal cells, and atrophic degeneration of the retinal pigment epithelium (RPE) has been described. This study investigates the effects of ICG on light-induced senescence of RPE cells.
  
  
  METHODS
  Primary human RPE cells were either pre-incubated with ICG in concentrations of 0.005% and 0.05% or not and then exposed to white light. After 10 min of irradiation viability, induction of intracellular reactive oxygen species (ROS) and senescence-associated β-galactosidase activity (SA β-Gal) were determined. Expression and secretion of matrix metalloproteinases (MMPs) 1 and 3 and their mRNA were determined by RT-PCR and ELISA.
  
  
  RESULTS
  Light exposure decreased RPE cell viability by 46%. Treatment with 0.005% and 0.05% ICG alone decreased RPE cell viability by 7% and 21%. In addition, expression of ROS, SA β-Gal, and MMP-1 and 3 was significantly increased. When 0.005% and 0.05% ICG treatments were combined with light exposure, viability decreased by 69% and 82% compared to the untreated control. Effects on the expression of ROS, SA β-Gal, and MMP-1 and 3 were, depending on the ICG dose, significantly increased when cells were pre-incubated with ICG and then illuminated.
  
  
  CONCLUSIONS
  In this study, pretreatment with ICG significantly increased light-induced oxidative stress and senescence. This might indicate a potential, supplementary mechanism that could explain RPE alterations and reduced functional results after ICG-assisted internal limiting membrane peeling.
authors.affiliation: Department of Ophthalmology, Ludwig Maximilian University, Munich, Germany. marcus.kernt@med.uni-muenchen.de
authors.forename: Marcus
authors.initials: M
authors.lastname: Kernt
authors.forename: Christoph
authors.initials: C
authors.lastname: Hirneiss
authors.forename: Armin
authors.initials: A
authors.lastname: Wolf
authors.forename: Raffael
authors.initials: R
authors.lastname: Liegl
authors.forename: Johann
authors.initials: J
authors.lastname: Rueping
authors.forename: Aljoscha
authors.initials: A
authors.lastname: Neubauer
authors.forename: Claudia
authors.initials: C
authors.lastname: Alge
authors.forename: Michael
authors.initials: M
authors.lastname: Ulbig
authors.forename: Arndt
authors.initials: A
authors.lastname: Gandorfer
authors.forename: Anselm
authors.initials: A
authors.lastname: Kampik
authors.forename: Christos
authors.initials: C
authors.lastname: Haritoglou
mesh_terms: D002478:Cells, Cultured; D016922:Cellular Senescence / Q000528:radiation effects*; D004396:Coloring Agents / Q000633:toxicity*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007208:Indocyanine Green / Q000633:toxicity*; D008027:Light; D020781:Matrix Metalloproteinase 1 / Q000235:genetics / Q000378:metabolism*; D019278:Matrix Metalloproteinase 3 / Q000235:genetics / Q000378:metabolism*; D018384:Oxidative Stress / Q000528:radiation effects*; D012333:RNA, Messenger / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D055213:Retinal Pigment Epithelium / Q000187:drug effects* / Q000201:enzymology / Q000528:radiation effects; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D004396:Coloring Agents; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; C061901:GLB1 protein, human; D001616:beta-Galactosidase; D019278:Matrix Metalloproteinase 3; D020781:Matrix Metalloproteinase 1; D007208:Indocyanine Green