Figure 4. Oxidative lipid and DNA changes in the meibomian glands.

A, Late phase lipid peroxidation marker 4-HNE stainings show dense staining in the 50 week old Cu, Zn-Superoxide Dismutase-1 knockout (Sod1 ^−/−) mice. Wild type (WT) mice specimens also had some staining but not to the extent observed in the same age Sod1 ^−/− mice. Bar = 50 micrometer. B, The extent of cellular staining with 4-HNE was significantly higher in the Sod1 ^−/− than the WT mice at 50 weeks (p = 0.0022). Note the significant timewise elevation in the anti-4-HNE staining from 10 to 50 weeks in the Sod1 ^−/− mice. C, Staining with 8-OHdG antibodies in Sod1 ^−/− and WT mice samples at 10 and 50 weeks. Meibomian gland acinar cell nuclei showed scant staining in 10 week Sod1 ^−/− and WT mice. Bar = 100 micrometer. There was a marked increase in nuclear staining from 10 to 50 weeks, especially in Sod1 ^−/− mice. Relatively more acinar nuclei were stained with anti-8-OHdG antibodies in the Sod1 ^−/− mice at 50 weeks compared to meibomian gland specimens from the same age WT mice. D, Quantitative assessment for the cellular staining of anti-8-OHdG antibodies showed a statistically significant timewise increase from 10 to 50 weeks in Sod1 ^−/− and WT mice (p = 0.0003, p = 0.0011, respectively). A significant timewise elevation in staining was observed in the Sod1 ^−/− and WT mice at 50 weeks (p = 0.0133). Five tissue sections of each animal's eye were analyzed to produce the figure. Data represent the mean ± standard deviation for 7 mice from the Sod1 ^−/− group and 6 mice from the wild type group at 10 and 50 weeks.