title: Cysteine suppresses oxidative stress-induced myofibrillar proteolysis in chick myotubes.
abstract: The effects of cysteine as an antioxidant nutrient on change in protein modification and myofibrillar proteolysis in chick myotubes by induction of oxidative stress by H(2)O(2) treatment were investigated. Myotubes were treated for 1 h with H(2)O(2) (1 mM). After this treatment, the H(2)O(2) was removed and the cells were cultured in cysteine (0.1 and 1 mM) containing serum-free medium for 24 h. Protein carbonyl content as an index of protein modification and N(tau)-methylhistidine release as an index of myofibrillar proteolysis were increased at 24 h after H(2)O(2) treatment, and the increment was reduced by cysteine. Calpain, proteasome and cathepsin (B+L and D) activities were increased at 24 h after H(2)O(2) treatment, and the increment was also reduced by cysteine. These results indicate that cysteine suppresses protein modification by oxidative stress, resulting in a decrease of protease acitivities, finally resulting in a decrease in myofibrillar proteolysis in chick myotubes.
authors.affiliation: Nutrient Function Laboratory, Department of Animal Physiology and Nutrition, National Institute of Livestock and Grassland Science, Ibaraki, Japan. kaznaka@affrc.go.jp
authors.forename: Kazuki
authors.initials: K
authors.lastname: Nakashima
authors.forename: Shigehiko
authors.initials: S
authors.lastname: Masaki
authors.forename: Makoto
authors.initials: M
authors.lastname: Yamazaki
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Abe
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002401:Cathepsin B / Q000378:metabolism; D056668:Cathepsin L; D002403:Cathepsins / Q000378:metabolism; D002478:Cells, Cultured; D002642:Chick Embryo; D002851:Chromatography, High Pressure Liquid; D003545:Cysteine / Q000494:pharmacology*; D003546:Cysteine Endopeptidases / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008762:Methylhistidines / Q000378:metabolism; D018485:Muscle Fibers, Skeletal / Q000187:drug effects / Q000378:metabolism*; D009210:Myofibrils / Q000187:drug effects / Q000378:metabolism*; D016877:Oxidants / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D010447:Peptide Hydrolases / Q000378:metabolism*; D011499:Protein Processing, Post-Translational / Q000187:drug effects
chemical_list: D000975:Antioxidants; D008762:Methylhistidines; D016877:Oxidants; D006861:Hydrogen Peroxide; D002403:Cathepsins; D010447:Peptide Hydrolases; D003546:Cysteine Endopeptidases; D002401:Cathepsin B; D056668:Cathepsin L; D003545:Cysteine; C028118:3-methylhistidine