title: Proteomic changes in rat gastrocnemius muscle after botulinum toxin a injection.
abstract: OBJECTIVE
  To observe the changes in protein expression induced by botulinum toxin A (BoNT-A) injection and to characterize the molecular and cellular action of mechanisms of BoNT-A injection on skeletal muscles using proteomic elements as biomarkers.
  
  
  METHODS
  BoNT-A was injected into left gastrocnemius muscles of 12 Sprague-Dawley rats (2 months of age) at a dosage of 5 units/kg body weight. For the controls same volume of normal saline was injected to right gastrocnemius muscle of each rat. Muscle samples were obtained at 4 time points (3 rats per time point): 3, 7, 14, and 56 day post-injection. To reveal the alterations in muscle protein, we performed 2-dimensional electrophoresis (2DE) and compared Botox group and normal saline group at each time point. Altered protein spots in 2DE were identified using matrix-assisted laser desorption/ionization-time-of-flight mass spectrometer (MALDI-TOF MS) proteomics analysis.
  
  
  RESULTS
  Compared with normal saline group, 46 protein spots showed changed protein expression. Twelve protein spots demonstrated increased volume and 34 protein spots demonstrated decreased volume. Among spots of decreased volume, 17 spots showed statistically significant differences. Thirty-eight identified proteins were associated with alterations in energy metabolism, muscle contractile function, transcription, translation, cell proliferation, and cellular stress response.
  
  
  CONCLUSIONS
  BoNT-A gives influences on muscle contractile function and energy metabolism directly or indirectly besides neurotoxic effects. Proteomic expression provides better understanding about the effect of BoNT-A on skeletal muscle.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Inje University Busan Paik Hospital, Inje University College of Medicine, Busan, Korea.
authors.forename: Nami
authors.initials: N
authors.lastname: Han
authors.forename: Hyun Dong
authors.initials: HD
authors.lastname: Kim
authors.forename: Mi-Ja
authors.initials: MJ
authors.lastname: Eom
authors.forename: Jun Myeong
authors.initials: JM
authors.lastname: You
authors.forename: Jin
authors.initials: J
authors.lastname: Han
authors.forename: Hyoung Kyu
authors.initials: HK
authors.lastname: Kim
authors.forename: Mi Seon
authors.initials: MS
authors.lastname: Kang
keywords: Botulinum toxins; Proteomics; Skeletal muscle; Two-dimensional gel electrophoresis