Effects of calorie restriction and aging on the expression of antioxidant enzymes and ubiquitin in the liver of Emory mice.
We studied the effect of age and calorie restriction on the expression of genes involved in antioxidant defenses in livers of young (4.5-6 months) and old (22 months) Emory mice fed a control (C) or restricted (R) diet. Specifically examined were catalase (CAT), glutathione peroxidase (Gpx), Cu/Zn and Mn superoxide dismutase (Cu/ZnSOD and MnSOD). As an indicator of oxidative damage to the tissues we measured lipid peroxidation. As indicators of oxidative stress we determined ubiquitin mRNA levels and endogenous high molecular weight (HMW) ubiquitin conjugates. Lower mRNA levels of ubiquitin (P < 0.05), CAT (P < 0.01) and Gpx (P < 0.01) were observed in tissues from young R versus C animals. The old C group had a lower CAT mRNA level (P < 0.0001) compared with young C. In the R group, age did not affect the CAT mRNA levels or Gpx mRNA levels; however, ubiquitin mRNA levels were higher (P < 0.05). No significant changes in Cu/Zn or MnSOD mRNA were observed with age or diet. Cu/ZnSOD protein levels were lower in the young R at 4.5 months (P < 0.05) than young C, and higher in the old R group versus old C (P < 0.05). CAT protein levels were higher in the old C versus old R (P < 0.05). Changes of HMW ubiquitin conjugates with age r diet were not significant. Of the four groups, the old R group showed the highest levels of lipid peroxidation.
Laboratory for Nutrition and Vision Research, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA.
C V
CV
Mura
X
X
Gong
A
A
Taylor
R
R
Villalobos-Molina
M M
MM
Scrofano
D000375:Aging / Q000502:physiology*; D000818:Animals; D015415:Biomarkers; D015152:Blotting, Northern; D002374:Catalase / Q000096:biosynthesis* / Q000235:genetics; D018753:Diet, Protein-Restricted; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005979:Glutathione Peroxidase / Q000096:biosynthesis* / Q000235:genetics; D015227:Lipid Peroxidation / Q000502:physiology; D008099:Liver / Q000378:metabolism*; D008297:Male; D051379:Mice; D012333:RNA, Messenger / Q000032:analysis; D011897:Random Allocation; D013482:Superoxide Dismutase / Q000096:biosynthesis* / Q000235:genetics; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014452:Ubiquitins / Q000096:biosynthesis* / Q000235:genetics
D015415:Biomarkers; D012333:RNA, Messenger; D017392:Thiobarbituric Acid Reactive Substances; D014452:Ubiquitins; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase