title: Monitoring changes in thioredoxin and over-oxidised peroxiredoxin in response to exercise in humans.
abstract: BACKGROUND
  Peroxiredoxin (PRDX) and thioredoxin (TRX) are antioxidant proteins that control cellular signalling and redox balance, although their response to exercise is unknown. This study aimed to assess key aspects of the PRDX-TRX redox cycle in response to three different modes of exercise.
  
  
  METHODS
  Healthy males (n = 10, mean ± SD: 22 ± 3 yrs) undertook three exercise trials on separate days: two steady-state cycling trials at moderate (60% [Formula: see text]O2MAX; 27 min, MOD) and high (80% [Formula: see text]O2MAX; 20 min, HIGH) intensities, and a low-volume high-intensity interval training trial (10 × 1 min 90% [Formula: see text]O2MAX, LV-HIIT). Peripheral blood mononuclear cells were assessed for TRX-1 and over-oxidised PRDX (isoforms I-IV) protein expression before, during, and 30 min following exercise (post + 30). The activities of TRX reductase (TRX-R) and the nuclear factor kappa B (NF-κB) p65 subunit were also assessed.
  
  
  RESULTS
  TRX-1 increased during exercise in all trials (MOD, + 84.5%; HIGH, + 64.1%; LV-HIIT, + 205.7%; p < 05), whereas over-oxidised PRDX increased during HIGH only (MOD, - 28.7%; HIGH, + 202.9%; LV-HIIT, - 22.7%; p < .05). TRX-R and NF-κB p65 activity increased during exercise in all trials, with the greatest response in TRX-R activity seen in HIGH (p < 0.05).
  
  
  CONCLUSIONS
  All trials stimulated a transient increase in TRX-1 protein expression during exercise. Only HIGH induced a transient over-oxidation of PRDX, alongside the greatest change in TRX-R activity. Future studies are needed to clarify the significance of heightened peroxide exposure during continuous high-intensity exercise and the mechanisms of PRDX-regulatory control.
authors.affiliation: School of Sport, Exercise & Rehabilitation Sciences, University of Birmingham , Edgbaston, Birmingham , UK.
authors.forename: A J
authors.initials: AJ
authors.lastname: Wadley
authors.forename: Y W
authors.initials: YW
authors.lastname: Chen
authors.forename: S J
authors.initials: SJ
authors.lastname: Bennett
authors.forename: G Y H
authors.initials: GY
authors.lastname: Lip
authors.forename: J E
authors.initials: JE
authors.lastname: Turner
authors.forename: J P
authors.initials: JP
authors.lastname: Fisher
authors.forename: S
authors.initials: S
authors.lastname: Aldred
mesh_terms: D000328:Adult; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000201:enzymology; D008297:Male; D016328:NF-kappa B / Q000378:metabolism; D010084:Oxidation-Reduction; D054464:Peroxiredoxins / Q000378:metabolism*; D015398:Signal Transduction; D013880:Thioredoxin-Disulfide Reductase / Q000378:metabolism; D013879:Thioredoxins / Q000378:metabolism*; D055815:Young Adult
chemical_list: D016328:NF-kappa B; C491203:TXN protein, human; D013879:Thioredoxins; D054464:Peroxiredoxins; D013880:Thioredoxin-Disulfide Reductase
keywords: Redox status; antioxidant; cytokines; exercise; inflammation