title: Impaired expression of insulin-like growth factor-1 system in skeletal muscle of amyotrophic lateral sclerosis patients.
abstract: BACKGROUND
  Adult muscle fibers are a source of growth factors, including insulin-like growth factor-1 (IGF-1). These factors influence neuronal survival, axonal growth, and maintenance of synaptic connections.
  
  
  METHODS
  We investigated the components of the IGF system in skeletal muscle samples obtained from 17 sporadic amyotrophic lateral sclerosis patients (sALS) and 29 control subjects (17 with normal muscle and 12 with denervated muscle unrelated to ALS).
  
  
  RESULTS
  The muscle expression of IGF-1 and IGF-binding proteins 3, 4, and 5 (IGF-BP3, -4, and -5, respectively), assessed by immunohistochemistry, was differently decreased in sALS compared with both control groups; conversely, IGF-1 receptor β subunit (IGF-1Rβ) was significantly increased. Western blot analysis confirmed the severe reduction of IGF-1, IGF-BP3, and -BP5 with the increment of IGF-1Rβ in sALS.
  
  
  CONCLUSIONS
  In this study we describe the abnormal expression of the IGF-1 system in skeletal muscle of sALS patients that could participate in motor neuron degeneration and should be taken into account when developing treatments with IGF-1.
authors.affiliation: Department of Neurology and Laboratory of Neuroscience, Dino Ferrari Center, IRCCS Istituto Auxologico Italiano, Università degli Studi di Milano, Milano, Italy. christian.lunetta@centrocliniconemo.it
authors.forename: Christian
authors.initials: C
authors.lastname: Lunetta
authors.forename: Massimo
authors.initials: M
authors.lastname: Serafini
authors.forename: Alessandro
authors.initials: A
authors.lastname: Prelle
authors.forename: Paolo
authors.initials: P
authors.lastname: Magni
authors.forename: Elena
authors.initials: E
authors.lastname: Dozio
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Ruscica
authors.forename: Jenny
authors.initials: J
authors.lastname: Sassone
authors.forename: Clarissa
authors.initials: C
authors.lastname: Colciago
authors.forename: Maurizio
authors.initials: M
authors.lastname: Moggio
authors.forename: Massimo
authors.initials: M
authors.lastname: Corbo
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Silani
mesh_terms: D000328:Adult; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000473:pathology*; D000704:Analysis of Variance; D002478:Cells, Cultured; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism* / Q000503:physiopathology*; D017526:Receptor, IGF Type 1 / Q000378:metabolism
chemical_list: D018969:Insulin-Like Growth Factor Binding Proteins; D007334:Insulin-Like Growth Factor I; D017526:Receptor, IGF Type 1