title: Dual effects of caspase-1, interleukin-1 beta, tumour necrosis factor-alpha and nerve growth factor receptor in inflammatory myopathies.
abstract: OBJECTIVE
  To analyse the expression of factors potentially involved in skeletal muscle degeneration and regeneration in dermatomyositis (DM), systemic sclerosis (SSc), polymyositis (PM), systemic lupus erythematosus (SLE) and non-inflammatory myopathies.
  
  
  METHODS
  Immunohistochemical staining of skeletal muscle biopsies (10 DM, 10 SSc, 10 PM, 10 SLE, 10 non-inflammatory myopathies) for tumour necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), activated caspase-1, pan-macrophage marker CD68, inducible nitric oxide synthase (NOS2) and nerve growth factor receptor (NGFR). TechMate staining robot and biotin-streptavidin protocol were used.
  
  
  RESULTS
  Expression of TNF-alpha, IL-1 beta, caspase-1 and NOS2 was found in the cytoplasm and sarcolemma of dystrophic skeletal muscle fibres. TNF-alpha and IL-1 beta immunoreactive profiles were faint and few and close to satellite nuclei-containing regenerating muscle fibres both in inflammatory and non-inflammatory myopathies. NGFR expression was found in comparable areas. In non-inflammatory inherited myopathies more nuclei were caspase-1 immunoreactive whereas caspase-1 expression was rarely seen in inflammatory myopathies, implying regeneration of the affected muscle fibres.
  
  
  CONCLUSIONS
  Prominent expression of the proinflammatory factors TNF-alpha, IL-1 beta and NOS2 and caspase-1 is associated with muscle fibre damage, albeit when expressed to a low degree these factors may, like NGFR, contribute to muscle regeneration and healing.
authors.affiliation: Institute of Biomedicine/Anatomy, Biomedicum Helsinki, University of Helsinki, Finland.
authors.forename: Z
authors.initials: Z
authors.lastname: Mackiewicz
authors.forename: M
authors.initials: M
authors.lastname: Hukkanen
authors.forename: D
authors.initials: D
authors.lastname: Povilenaite
authors.forename: A
authors.initials: A
authors.lastname: Sukura
authors.forename: J E
authors.initials: JE
authors.lastname: Fonseca
authors.forename: I
authors.initials: I
authors.lastname: Virtanen
authors.forename: Y T
authors.initials: YT
authors.lastname: Konttinen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D020170:Caspase 1 / Q000378:metabolism*; D003882:Dermatomyositis / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007375:Interleukin-1 / Q000378:metabolism*; D008180:Lupus Erythematosus, Systemic / Q000150:complications / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology; D017285:Polymyositis / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D020800:Receptor, Nerve Growth Factor / Q000378:metabolism*; D012038:Regeneration / Q000502:physiology; D012595:Scleroderma, Systemic / Q000150:complications / Q000378:metabolism / Q000473:pathology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D007375:Interleukin-1; D020800:Receptor, Nerve Growth Factor; D014409:Tumor Necrosis Factor-alpha; D020170:Caspase 1