title: Effects of 17β-estradiol on proliferation, cell viability and intracellular redox status in native human lens epithelial cells.
abstract: OBJECTIVE
  The purpose of this study was to examine the effects of 17β-estradiol on proliferation, cell death and redox status in cultured human lens epithelial cells (HLECs).
  
  
  METHODS
  HLECs were exposed to 17β-estradiol after which cell viability was measured by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) and the number of mitotic and apoptotic cell nuclei was determined after staining with Hoechst 33342. Apoptosis was also determined by measuring caspase-3 activity and propidium iodide was used to determine the proportion of non-viable cells. Pro- and antioxidative effects of 17β-estradiol was investigated by measuring peroxides, superoxides and glutathione, using dichlorofluorescein diacetate (DCFH-DA), dihydroethidium (HET), and monochlorobimane (MCB), respectively. Effects on mitochondrial membrane potential were determined using 5,5',6,6'-tetrachloro-1,1',3,3'- tetraethylbenzimidazolylcarbocyanine iodide (JC-1). The ability of 17β-estradiol to prevent reactive oxygen species (ROS)-production in HLECs after exposure to 25 µM H₂O₂ for 24h was also measured.
  
  
  RESULTS
  This study demonstrates increased mitotic activity in HLECs exposed to physiologic concentrations of 17β-estradiol (1 nM). Pharmacological concentrations of 17β-estradiol caused increased number of apoptotic cell nuclei and caspase-3 activation. Physiologic concentrations of 17β-estradiol (0.1-10 nM) stabilized the mitochondrial membrane potential. Similar or slightly higher concentrations of 17β-estradiol (0.01-1 µM) protected against H₂O₂-induced oxidative stress as evident by decreased levels of peroxides and superoxides.
  
  
  CONCLUSIONS
  The present study demonstrates mitogenic and anti-oxidative effects of 17β-estradiol at physiologic concentrations, whereas pharmacological levels induced oxidative stress and acted pro-apoptotic in cultured lens cells.
authors.affiliation: Institute of Neuroscience and Physiology, Department of Clinical Neuroscience and Rehabilitation/Ophthalmology, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden. dragana.celojevic@gu.se
authors.forename: D
authors.initials: D
authors.lastname: Celojevic
authors.forename: A
authors.initials: A
authors.lastname: Petersen
authors.forename: J-O
authors.initials: JO
authors.lastname: Karlsson
authors.forename: A
authors.initials: A
authors.lastname: Behndig
authors.forename: M
authors.initials: M
authors.lastname: Zetterberg
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D053148:Caspase 3 / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology*; D005456:Fluorescent Dyes / Q000032:analysis; D005978:Glutathione / Q000032:analysis / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007908:Lens, Crystalline / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010545:Peroxides / Q000032:analysis; D061251:Primary Cell Culture; D011419:Propidium / Q000032:analysis; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors / Q000378:metabolism; D013481:Superoxides / Q000032:analysis
chemical_list: D005456:Fluorescent Dyes; D010545:Peroxides; D017382:Reactive Oxygen Species; D013481:Superoxides; D011419:Propidium; D004958:Estradiol; D006861:Hydrogen Peroxide; D053148:Caspase 3; D005978:Glutathione