title: Hindlimb unloading decreases thioredoxin-related antioxidant proteins and increases thioredoxin-binding protein-2 in rat skeletal muscle.
abstract: To investigate role(s) of thioredoxin-related antioxidant proteins in disuse muscle atrophy, we examined the levels of thioredoxin-1 (Trx-1), peroxiredoxin-3/SP-22 (Prx-3) and thioredoxin-binding protein-2 (TBP-2) in rat soleus muscle subjected to hindlimb unloading (HU) for 2, 4, 7 or 14 days. The muscle weight loss was initially observed on day 4. The increases in aclorein- and malondialdehyde-modified proteins, and the decreases in the levels of Trx-1, Prx-3 and Mn-SOD were observed in the late phase of muscle atrophy, whereas, the increase in mRNA expression of TBP-2, a negative regulator of thioredoxin, preceded muscle atrophy. These findings suggest that the decrease of those antioxidant proteins, particularly a marked decrease of Trx-1, may be responsible for the enhanced oxidative damage during the late phase of disuse muscle atrophy. Furthermore, the increase in TBP-2 preceding the muscle atrophy may suppress the thioredoxin-mediated redox signaling, which can be an initial trigger leading to disuse muscle atrophy.
authors.affiliation: Department of Rehabilitation Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan. y-matsu@med.uoeh-u.ac.jp
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Matsushima
authors.forename: Hiroki
authors.initials: H
authors.lastname: Nanri
authors.forename: Soichiro
authors.initials: S
authors.lastname: Nara
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Okufuji
authors.forename: Masanori
authors.initials: M
authors.lastname: Ohta
authors.forename: Kenji
authors.initials: K
authors.lastname: Hachisuka
authors.forename: Masaharu
authors.initials: M
authors.lastname: Ikeda
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D019417:Hindlimb Suspension; D008297:Male; D008315:Malondialdehyde; D018482:Muscle, Skeletal / Q000378:metabolism*; D009133:Muscular Atrophy / Q000378:metabolism*; D018384:Oxidative Stress; D010544:Peroxidases / Q000235:genetics / Q000378:metabolism*; D054464:Peroxiredoxins; D011499:Protein Processing, Post-Translational; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013482:Superoxide Dismutase / Q000378:metabolism; D013879:Thioredoxins / Q000235:genetics / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D012333:RNA, Messenger; C495697:Txn1 protein, rat; C504123:thioredoxin-binding protein-2, rat; D008315:Malondialdehyde; D013879:Thioredoxins; D010544:Peroxidases; D054464:Peroxiredoxins; D013482:Superoxide Dismutase