title: Melatonin and amfenac modulate calcium entry, apoptosis, and oxidative stress in ARPE-19 cell culture exposed to blue light irradiation (405 nm).
abstract: OBJECTIVE
  Under conditions of oxidative stress, cell apoptosis is triggered through the mitochondrial intrinsic pathway. Increased levels of reactive oxygen species (ROS) are linked to excess cell loss and mediate the initiation of apoptosis in a diverse range of cell types. The aims of this study were to assess intracellular Ca(2+) release, ROS production, and caspase-3, and -9 activation in ARPE-19 cells during the blue light-mediated cell death, and to examine a potential protective effect of melatonin and amfenac, in the apoptotic cascade.
  
  
  METHODS
  ARPE-19 cells were cultured in their medium. First, MTT tests were performed to determine the protective effects of amfenac and melatonin. Cells were then exposed to blue light irradiation in an incubator. Intracellular Ca(2+) release experiments, mitochondrial membrane depolarization, apoptosis assay, glutathione (GSH), glutathione peroxidase (GSH-Px), and ROS experiments were done according to the method stated in the Materials and methods section.
  
  
  RESULTS
  Cell death was clearly associated with increased levels of ROS production, as measured by 2',7'-dichlorofluorescein fluorescence, and associated increase in Ca(2+) levels, as measured by Fura-2-AM. Blue light-induced cell death was associated with an increased level of caspase-3 and 9, suggesting mediation via the apoptotic pathway. Cell death was also associated with mitochondrial depolarization. Melatonin was shown to delay these three steps.
  
  
  CONCLUSIONS
  Melatonin, amfenac, and their combination protect ARPE-19 cells against blue light-triggered ROS accumulation and caspase-3 and -9 activation. The antiapoptotic effect of melatonin and amfenac at doses inhibiting caspase synthesis modified Ca(2+) release and prevented excessive ROS production, suggesting a new therapeutic approach to age-related macular degeneration.
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Süleyman Demirel University, Isparta, Turkey.
authors.forename: M
authors.initials: M
authors.lastname: Argun
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Süleyman Demirel University, Isparta, Turkey.
authors.forename: L
authors.initials: L
authors.lastname: Tök
authors.affiliation: 1] Department of Biophysics, Faculty of Medicine, Süleyman Demirel University, Isparta, Turkey [2] Neuroscience Research Center, Süleyman Demirel University, Isparta, Turkey.
authors.forename: A C
authors.initials: AC
authors.lastname: Uğuz
authors.affiliation: 1] Department of Biophysics, Faculty of Medicine, Süleyman Demirel University, Isparta, Turkey [2] Neuroscience Research Center, Süleyman Demirel University, Isparta, Turkey.
authors.forename: Ö
authors.initials: Ö
authors.lastname: Çelik
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Süleyman Demirel University, Isparta, Turkey.
authors.forename: Ö Y
authors.initials: ÖY
authors.lastname: Tök
authors.affiliation: 1] Department of Biophysics, Faculty of Medicine, Süleyman Demirel University, Isparta, Turkey [2] Neuroscience Research Center, Süleyman Demirel University, Isparta, Turkey.
authors.forename: M
authors.initials: M
authors.lastname: Naziroğlu
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism*; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D002460:Cell Line; D002470:Cell Survival; D004338:Drug Combinations; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects; D008550:Melatonin / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects*; D010648:Phenylacetates / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D055213:Retinal Pigment Epithelium / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000975:Antioxidants; D004338:Drug Combinations; D010648:Phenylacetates; D017382:Reactive Oxygen Species; C014285:amfenac; D005979:Glutathione Peroxidase; D053148:Caspase 3; D053453:Caspase 9; D005978:Glutathione; D008550:Melatonin; D002118:Calcium