title: Ultraviolet radiation-induced cataract in mice: the effect of age and the potential biochemical mechanism.
abstract: OBJECTIVE
  To study the effect of age on the morphologic and biochemical alterations induced by in vivo exposure of ultraviolet radiation (UV).
  
  
  METHODS
  Young and old C57BL/6 mice were exposed to broadband UVB+UVA and euthanized after 2 days. Another batch of UV-exposed young mice was monitored for changes after 1, 2, 4, and 8 days. Age-matched nonexposed mice served as controls. Lens changes were documented in vivo by slit-lamp biomicroscopy and dark field microscopy photographs ex vivo. Lens homogenates were analyzed for glutathione (GSH) level, and the activities of thioredoxin (Trx), thioltransferase (TTase), and glyceraldehyde-3-phosphate dehydrogenase (G3PD). Glutathionylated lens proteins (PSSGs) were detected by immunoblotting using GSH antibody. Western blot analysis was also done for the expression levels of TTase and Trx.
  
  
  RESULTS
  Both age groups developed epithelial and superficial anterior subcapsular cataract at 2 days postexposure. The lens GSH level and G3PD activity were decreased, and PSSGs were elevated in both age groups, but more prominent in the older mice. TTase and Trx activity and protein expression were elevated only in the young mice. Interestingly, lens TTase and Trx in the young mice showed a transient increase, peaking at 2 days after UV exposure and returning to baseline at day 8, corroborated by lens transparency.
  
  
  CONCLUSIONS
  The lenses of old mice were more susceptible to UV radiation-induced cataract. The upregulated TTase and Trx likely provided oxidation damage repair in the young mice.
authors.affiliation: Department of Ophthalmology, Tangdu Hospital, the Fourth Military Medical University, Xi'an, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.forename: Hong
authors.initials: H
authors.lastname: Yan
authors.forename: Stefan
authors.initials: S
authors.lastname: Löfgren
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Tian
authors.forename: Marjorie F
authors.initials: MF
authors.lastname: Lou
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D002386:Cataract / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D003459:Crystallins / Q000096:biosynthesis*; D004195:Disease Models, Animal; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D054477:Glutaredoxins / Q000096:biosynthesis; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000096:biosynthesis; D007908:Lens, Crystalline / Q000378:metabolism / Q000528:radiation effects; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018384:Oxidative Stress; D013879:Thioredoxins / Q000096:biosynthesis; D014466:Ultraviolet Rays / Q000009:adverse effects; D015854:Up-Regulation
chemical_list: D003459:Crystallins; D054477:Glutaredoxins; D013879:Thioredoxins; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases