title: Functional and morphological evaluation of blue light-emitting diode-induced retinal degeneration in mice.
abstract: OBJECTIVE
  The purpose of this study was to evaluate a retinal degeneration (RD) model induced by exposing mice to a blue light-emitting diode (LED), which led to photoreceptor cell death.
  
  
  METHODS
  RD was induced in BALB/c mice by exposure to a blue LED (460 nm) for 2 hours. Retinal function was examined using scotopic electroretinography (ERG). Histopathological changes were assessed by hematoxylin and eosin (H&E) staining and electron microscopy. Apoptotic cell death was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. In addition, retinal inflammation and oxidative stress were evaluated by immunohistochemistry with anti-glial fibrillary acidic protein (GFAP) and anti-8-hydroxy-2'-deoxyguanosine (8-OHdG), respectively.
  
  
  RESULTS
  Scotopic ERG showed that blue LED exposure resulted in a decrease in both a-waves and b-waves in mice retinas in an illuminance-dependent manner. H&E, TUNEL assay, and electron microscopy revealed massive photoreceptor cell death by apoptosis in the central region of the retina. Retinal stress and inflammation were detected by increased expression of GFAP and by electron microscopy findings demonstrating microglia infiltration in the outer nuclear layer and subretinal space. In addition, increased labeling of 8-OHdG was observed in the retinas from blue LED exposure.
  
  
  CONCLUSIONS
  These results suggest that blue LED-induced RD may be a useful animal model in which to study the pathogenesis of RD, including age-related macular degeneration, and to evaluate the effects of new therapeutic agents prior to clinical trials, where oxidative stress and inflammation are the underlying RD mechanisms.
authors.affiliation: Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul, 137-701, Korea.
authors.forename: Gyu Hyun
authors.initials: GH
authors.lastname: Kim
authors.affiliation: Gyeongju St. Mary's Eye Clinic, 293 Wonhwa-ro, Gyeongju-si, Gyeongsangbuk-do, 780-946, Korea.
authors.forename: Hyung Il
authors.initials: HI
authors.lastname: Kim
authors.affiliation: Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul, 137-701, Korea.
authors.forename: Sun-Sook
authors.initials: SS
authors.lastname: Paik
authors.affiliation: Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul, 137-701, Korea.
authors.forename: Sung Won
authors.initials: SW
authors.lastname: Jung
authors.affiliation: Department of Ophthalmology, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul, 137-701, Korea.
authors.forename: Seungbum
authors.initials: S
authors.lastname: Kang
authors.affiliation: Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul, 137-701, Korea. ibkimmd@catholic.ac.kr.|Catholic Institute for Applied Anatomy, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul, 137-701, Korea. ibkimmd@catholic.ac.kr.
authors.forename: In-Beom
authors.initials: IB
authors.lastname: Kim
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000818:Animals; D016923:Cell Death; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D004596:Electroretinography; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D008027:Light / Q000009:adverse effects*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008854:Microscopy, Electron; D020419:Photoreceptor Cells, Vertebrate / Q000473:pathology / Q000528:radiation effects*; D011833:Radiation Injuries, Experimental / Q000209:etiology*; D012162:Retinal Degeneration / Q000209:etiology*
chemical_list: D005904:Glial Fibrillary Acidic Protein; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine
keywords: Animal model; Apoptotic cell death; Blue light-emitting diode; Photoreceptor; Retinal degeneration