title: Expression of the stress proteins, ubiquitin, heat shock protein 72, and myofibrillar protein content after 12 weeks of leg cycling in persons with spinal cord injury.
abstract: OBJECTIVE
  To determine the effects of leg cycling exercise on ubiquitin (UBI), heat shock protein 72 (HSP-72) mRNA, protein expression, and myofibrillar protein content in individuals with spinal cord injury (SCI).
  
  
  METHODS
  Case series.
  
  
  METHODS
  Motor behavior laboratory.
  
  
  METHODS
  Seven subjects with motor-complete SCI (4 men, 3 women).
  
  
  METHODS
  A 12-week exercise program involving an electromagnetically braked recumbent bicycle ergometer, which allowed for passive exercise of the legs. Training occurred 2 days a week at approximately 75% of each subject's maximum heart rate.
  
  
  METHODS
  Total body mass (TBM) and muscle biopsies were obtained pre- and posttraining. The mRNA and protein expression of UBI, HSP-72, and myofibrillar protein content were determined.
  
  
  RESULTS
  Nonsignificant increases (P > .05) of 2.45% were observed for TBM. There were significant increases (P < .05) in the expression of both HSP-72 mRNA (33.71%) and protein (30.23%). For UBI, there were also significant decreases (P < .05) in the expression of both mRNA (26.86%) and protein (69.43%). Myofibrillar protein content increased significantly (P < .05, 41.86%).
  
  
  CONCLUSIONS
  Leg cycling exercise in SCI increases myofibrillar protein content, possibly because of up-regulation in the expression of HSP-72 with concomitant down-regulation in the expression of UBI.
authors: Department of Kinesiology, Texas Christian University, Fort Worth, TX 76129, USA. d.willoughby@tcu.edu
authors: Darryn S
authors: DS
authors: Willoughby
authors: Joe W
authors: JW
authors: Priest
authors: Matt
authors: M
authors: Nelson
mesh_terms: D000293:Adolescent; D000328:Adult; D001642:Bicycling / Q000502:physiology*; D005081:Exercise Therapy; D005260:Female; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000032:analysis* / Q000235:genetics; D006801:Humans; D007866:Leg / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D009124:Muscle Proteins / Q000032:analysis* / Q000235:genetics; D018482:Muscle, Skeletal / Q000473:pathology / Q000503:physiopathology; D009210:Myofibrils / Q000235:genetics / Q000473:pathology / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis* / Q000235:genetics; D013119:Spinal Cord Injuries / Q000473:pathology / Q000503:physiopathology* / Q000534:rehabilitation*; D013997:Time Factors; D025801:Ubiquitin / Q000032:analysis* / Q000235:genetics
chemical_list: D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D009124:Muscle Proteins; D012333:RNA, Messenger; D025801:Ubiquitin