title: Protective effect of the thioltransferase gene on in vivo UVR-300 nm-induced cataract.
abstract: OBJECTIVE
  To determine the protection factor (PF) for glutaredoxin-1 (Grx1) with regard to UVR-induced cataract by comparison of in vivo ultraviolet radiation (UVR) lens toxicity between double knockout Grx1⁻/⁻ and Grx1⁺/⁺ mice.
  
  
  METHODS
  Twenty Grx1⁺/⁺ mice and 20 Grx1⁻/⁻ mice were unilaterally exposed in vivo to UVR for 15 minutes. Groups of four animals each received 0.0, 2.1, 2.9, 3.6, and 4.1 kJ/m(2) UVR-300 nm. At 48 hours after UVR exposure, light-scattering in the exposed and contralateral nonexposed lenses was measured quantitatively. Macroscopic lens changes were documented with dark-field illumination photography.
  
  
  RESULTS
  UVR-300 nm induced subcapsular and cortical cataract in Grx1⁻/⁻ and Grx1⁺/⁺ mice. In both Grx1⁻/⁻ and Grx1⁺/⁺, the light-scattering intensified with increased in vivo exposure doses of UVR-300 nm. The intensity of forward light-scattering was higher in the lenses of Grx1⁻/⁻ mice than in the lenses of Grx1⁺/⁺ mice. The threshold dose for in vivo UVR-300 nm-induced cataract, expressed as MTD(2.3:16), was 3.8 in the Grx1⁺/⁺ group and 3.0 in the Grx1⁻/⁻ group, resulting in a PF of 1.3.
  
  
  CONCLUSIONS
  The PF is an objective relative measure of protective properties. The Grx1 gene is associated with an in vivo PF of 1.3. This result signifies that the presence of the gene allows a 1.3 times longer in vivo exposure to UVR, at equivalent irradiance, than the absence of the gene before early-onset, UVR-induced cataract occurs. This finding indicates the important role of the Grx1 gene in the oxidation defense system of the lens.
authors.affiliation: Gullstrand Lab, Ophthalmology, Department of Neuroscience, Uppsala University, Uppsala, Sweden. martin.kronschlager@ophthalmology.neuro.uu.se
authors.forename: Martin
authors.initials: M
authors.lastname: Kronschläger
authors.forename: Konstantin
authors.initials: K
authors.lastname: Galichanin
authors.forename: Joakim
authors.initials: J
authors.lastname: Ekström
authors.forename: Marjorie F
authors.initials: MF
authors.lastname: Lou
authors.forename: Per G
authors.initials: PG
authors.lastname: Söderberg
mesh_terms: D000818:Animals; D002386:Cataract / Q000209:etiology / Q000517:prevention & control*; D005786:Gene Expression Regulation / Q000502:physiology*; D054477:Glutaredoxins / Q000235:genetics*; D007908:Lens, Crystalline / Q000528:radiation effects*; D008027:Light; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010084:Oxidation-Reduction; D011833:Radiation Injuries, Experimental / Q000209:etiology / Q000517:prevention & control*; D012542:Scattering, Radiation; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: C516006:Glrx protein, mouse; D054477:Glutaredoxins