Protective effect of the thioltransferase gene on in vivo UVR‐300 nm induced cataract

Abstract

Abstract Purpose To determine the protective effect of the thioltransferase glutaredoxin 1 (Grx1), a critical protein‐thiol repair enzyme, on in vivo UVR‐induced cataract. Further, to estimate the MTD(2.3:16) for Grx1+/+ and Grx1‐/‐ mice and to calculate the protection factor for the thioltransferase gene on UVR‐induced cataract. Methods 20 Grx1+/+ and 20 Grx1‐/‐ mice were unilaterally exposed in vivo to UVR‐300 nm for 15 min. Altogether, 5 groups of 4 animals received 0.0, 2.1, 2.9, 3.6 or 4.1 kJ/m2 each. At 48 h post UVR exposure, light scattering in the exposed and contralateral not exposed lens was measured quantitatively. Macroscopic lens changes were documented with dark field illumination photography. Results Subcapsular and cortical opacities were observed in both the Grx1+/+ and Grx1‐/‐ mice. Forward light scattering in the lenses from the Grx1+/+ group was lower than in the lenses from the Grx1‐/‐ group and increased with increasing radiant exposure. The MTD(2.3:16) was for the Grx1+/+ group 3.81 (CI(0.95) = [2.82;6.37]) and for the Grx1‐/‐ group 2.99 (CI(0.95)= [2.33;4.00]) resulting in a protection factor of 1.28. Conclusion Deficiency of the Grx1 gene makes the lens 28 % more sensitive to early onset UVR‐300 nm induced cataract, indicating the important role of the Grx1 gene in the oxidation defense of the lens.