title: The role of Prdx6 in the protection of cells of the crystalline lens from oxidative stress induced by UV exposure.
abstract: OBJECTIVE
  The immediate aim of this study was to investigate alterations in peroxiredoxin (Prdx) 6 at posttranslational levels, and the levels of protein oxidation, lipid peroxidation, and reactive oxygen species (ROS) in lens epithelial cells (LECs) after exposure to severe oxidative stress, such as ultraviolet-B (UV-B). Our ultimate aim was to provide new information on antioxidant defenses in the lens and their regulation, thereby broadening existing knowledge of the role of Prdx6 in lens physiology and pathophysiology.
  
  
  METHODS
  The expression of the hyperoxidized form of Prdx6 and oxidation of protein were analyzed by western blotting and the OxyBlot assay in human LECs (hLECs). ROS levels were quantified using DCFH-DA dye, and cell viability was quantified by the MTS and TUNEL assays. To evaluate the protective effect of Prdx6, we cultured lenses with or without the TAT transduction domain (TAT-HA-Prdx6) and observed (and photographed) the cultures at specified time-points after the exposure to UV-B for the development of opacity.
  
  
  RESULTS
  Prdx6 in hLECs was hyperoxidized after exposure to high amounts of UV-B. UV-B treatment of hLECs increased the levels of cell death, protein oxidation, and ROS. hLECs exposed to UV-B showed higher levels of ROS, which could be reduced by the application of extrinsic TAT-HA-Prdx6, attenuating UV-B-induced lens opacity and apoptotic cell death.
  
  
  CONCLUSIONS
  Excessive oxidative stress induces the hyperoxidation of Prdx6 and may reduce the ability of Prdx6 to protect LECs against ROS or stresses. Because extrinsic Prdx6 could attenuate UV-B-induced abuse, this molecule may have a potential in preventing cataractogenesis.
authors.affiliation: Department of Ophthalmology, Kanazawa Medical University, 1-1 Daigaku, Uchinada, Kahoku, Ishikawa, 920-0293, Japan.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Shibata
authors.affiliation: Department of Ophthalmology, Kanazawa Medical University, 1-1 Daigaku, Uchinada, Kahoku, Ishikawa, 920-0293, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Shibata
authors.affiliation: Department of Ophthalmology, Kanazawa Medical University, 1-1 Daigaku, Uchinada, Kahoku, Ishikawa, 920-0293, Japan.
authors.forename: Teppei
authors.initials: T
authors.lastname: Shibata
authors.affiliation: Department of Ophthalmology, Kanazawa Medical University, 1-1 Daigaku, Uchinada, Kahoku, Ishikawa, 920-0293, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sasaki
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, USA.
authors.forename: Dhirendra P
authors.initials: DP
authors.lastname: Singh
authors.affiliation: Department of Ophthalmology, Kanazawa Medical University, 1-1 Daigaku, Uchinada, Kahoku, Ishikawa, 920-0293, Japan. kuboe@kanazawa-med.ac.jp.
authors.forename: Eri
authors.initials: E
authors.lastname: Kubo
mesh_terms: D000818:Animals; D017209:Apoptosis; D002470:Cell Survival; D002478:Cells, Cultured; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D020287:In Situ Nick-End Labeling; D007908:Lens, Crystalline / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects; D018384:Oxidative Stress / Q000187:drug effects*; D054465:Peroxiredoxin VI / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: C515977:PRDX6 protein, human; D054465:Peroxiredoxin VI
keywords: Cataract; Lens epithelial cells; Oxidative stress; Peroxiredoxin 6; Ultraviolet-B