title: O-GlcNAc protein modification in C2C12 myoblasts exposed to oxidative stress indicates parallels with endogenous antioxidant defense.
abstract: A growing body of evidence demonstrates the involvement of protein modification with O-linked β-N-acetylglucosamine (O-GlcNAc) in the stress response and its beneficial effects on cell survival. Here we investigated protein O-GlcNAcylation in skeletal muscle cells exposed to oxidative stress and the crosstalk with endogenous antioxidant system. The study focused on antioxidant enzymes superoxide dismutase 2 (SOD2), catalase (CAT), and glutathione peroxidase 1 (GPX1), and transcriptional regulators proliferator-activated receptor gamma coactivator 1-α (PGC-1α) and forkhead box protein O1 (FOXO1), which play important roles in oxidative stress response and are known to be O-GlcNAc-modified. C2C12 myoblasts were subjected to 24 h incubation with different reagents, including hydrogen peroxide, diethyl maleate, high glucose, and glucosamine, and the inhibitors of O-GlcNAc cycling enzymes. Surprisingly, O-GlcNAc levels were significantly increased only with glucosamine, whilst other treatments showed no effect. Significant changes at the mRNA level were observed with concomitant upregulation of the genes for O-GlcNAc enzymes and stress-related proteins with oxidizing agents and downregulation of these genes with agents promoting O-GlcNAcylation. Our findings suggest a role of O-GlcNAc in the stress response and indicate an inhibitory mechanism controlling O-GlcNAc levels in the muscle cells. This could represent an important homeostatic regulation of the cellular defense system.
authors.affiliation: a Antioxidant Research Group, School of Human Movement Studies, The University of Queensland, Brisbane, QLD, Australia.
authors.forename: Tina Tinkara
authors.initials: TT
authors.lastname: Peternelj
authors.forename: Susan A
authors.initials: SA
authors.lastname: Marsh
authors.forename: Christudas
authors.initials: C
authors.lastname: Morais
authors.forename: David M
authors.initials: DM
authors.lastname: Small
authors.forename: Vincent J
authors.initials: VJ
authors.lastname: Dalbo
authors.forename: Patrick S
authors.initials: PS
authors.lastname: Tucker
authors.forename: Jeff S
authors.initials: JS
authors.lastname: Coombes
mesh_terms: D000117:Acetylglucosamine / Q000494:pharmacology*; D000818:Animals; D000975:Antioxidants; D002374:Catalase / Q000235:genetics; D002460:Cell Line; D000071161:Forkhead Box Protein O1; D051858:Forkhead Transcription Factors / Q000235:genetics; D005979:Glutathione Peroxidase / Q000235:genetics; D006360:Heat-Shock Proteins; D051379:Mice; D032446:Myoblasts / Q000378:metabolism*; D016877:Oxidants; D018384:Oxidative Stress / Q000187:drug effects*; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D011499:Protein Processing, Post-Translational; D013482:Superoxide Dismutase / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics; D000094765:Glutathione Peroxidase GPX1; D000099156:Superoxide Dismutase 2
chemical_list: D000117:Acetylglucosamine; D000975:Antioxidants; D002374:Catalase; D000071161:Forkhead Box Protein O1; D051858:Forkhead Transcription Factors; D005979:Glutathione Peroxidase; D006360:Heat-Shock Proteins; D016877:Oxidants; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D013482:Superoxide Dismutase; D014157:Transcription Factors; D000094765:Glutathione Peroxidase GPX1; D000099156:Superoxide Dismutase 2; C467200:Foxo1 protein, mouse; C485290:Ppargc1a protein, mouse; C000722068:Gpx1 protein, mouse
keywords: O-GlcNAc; adaptive response; antioxidant enzyme; enzyme anti-oxydante; myoblastes; myoblasts; oxidant; oxydant; réponse adaptative