title: Cu/Zn superoxide dismutase is differentially regulated in period gene-mutant mice.
abstract: The circadian clock in the brain coordinates the phase of peripheral oscillators that regulate tissue-specific physiological outputs. Here we report that circadian variations in the expression and activity of Cu/Zn superoxide dismutase (SOD1; EC 1.15.1.1) are present in liver homogenates from mice. The SOD1 mRNA expression from wild-type (WT) mice peaked at Zeitgeber Time 9 (ZT9; 9h after lights-on time). While there was no rhythmicity in that from period2 (per2) gene knockout (P2K) mice, the level of SOD1 from per1/per2 double knockout (DKO) mice was significantly elevated at ZT5. The enzyme activity of SOD1 was also rhythmic in the mouse liver. Moreover, the total amount of the SOD1 exhibited a rhythmic oscillation with a peak at ZT9 in the liver from WT mice. We also found that tert-butylhydroperoxide (t-BHP)-induced oxidative damage in both WT and P2K mouse embryonic fibroblast (MEF) cells resulted in the up-regulation of SOD1 levels. Our data suggest that the expression of an important antioxidant enzyme, SOD1, is under circadian clock control and that mice are more susceptible to oxidative stress depending on the time of day.
authors.affiliation: Division of Biological Science and Technology, Yonsei University, Wonju, Republic of Korea.
authors.forename: Yeong-Su
authors.initials: YS
authors.lastname: Jang
authors.forename: Myung-Han
authors.initials: MH
authors.lastname: Lee
authors.forename: Sang-Hyuk
authors.initials: SH
authors.lastname: Lee
authors.forename: Kiho
authors.initials: K
authors.lastname: Bae
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002940:Circadian Rhythm / Q000235:genetics*; D005347:Fibroblasts / Q000187:drug effects / Q000201:enzymology; D008099:Liver / Q000201:enzymology; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D018384:Oxidative Stress / Q000235:genetics*; D056950:Period Circadian Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D013482:Superoxide Dismutase / Q000096:biosynthesis* / Q000235:genetics; D000072105:Superoxide Dismutase-1; D020122:tert-Butylhydroperoxide / Q000494:pharmacology
chemical_list: C513312:Per2 protein, mouse; D056950:Period Circadian Proteins; D012333:RNA, Messenger; D020122:tert-Butylhydroperoxide; C000606291:Sod1 protein, mouse; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1