title: Intermediate filaments in the human extraocular muscles.
abstract: OBJECTIVE
  To investigate the distribution of the intermediate filament (IF) proteins desmin, vimentin, and nestin in human extraocular muscles (EOMs).
  
  
  METHODS
  Healthy adult EOM samples were serially sectioned (5 and 1 μm) and processed for immunohistochemistry, with specific antibodies (Abs) against desmin, vimentin, and nestin and different myosin heavy chains (MyHCs), including the newly characterized Ab MYH7b against MyHC slow tonic. The distribution of desmin was also studied in EOMs at 16 to 18 weeks of gestation.
  
  
  RESULTS
  Desmin was present in the vast majority of muscle fibers. Notably, muscle fibers that contained MyHC slow tonic were either unlabeled or very weakly labeled with three different Abs against desmin. These muscle fibers had normal cytoarchitecture and intact basement membrane. In fetal muscle, desmin was also absent or weak in myotubes containing MyHC slow tonic. Nestin was detected in a large proportion of muscle fibers in the orbital layer and to some extent also in the global layer, whereas no muscle fibers contained vimentin. Desmin and nestin were enriched at neuromuscular junctions, as in limb muscle. In contrast, some myotendinous junctions lacked desmin or nestin.
  
  
  CONCLUSIONS
  The human EOMs differed significantly from the other muscles in the body with respect to their IF composition. Desmin, hitherto regarded as a ubiquitous muscle cytoskeletal protein, was absent or only present in trace amounts in a subset of normal muscle fibers in adult and fetal EOMs. Nestin, normally downregulated early in the postnatal period, was present in a high proportion of adult muscle fibers.
authors.affiliation: Department of Clinical Sciences, Ophthalmology, Umeå University, Umeå, Sweden Department of Integrative Medical Biology, Section of Anatomy, Umeå University, Umeå, Sweden.
authors.forename: Adrihan H
authors.initials: AH
authors.lastname: Janbaz
authors.affiliation: Department of Integrative Medical Biology, Section of Anatomy, Umeå University, Umeå, Sweden.
authors.forename: Mona
authors.initials: M
authors.lastname: Lindström
authors.affiliation: Department of Integrative Medical Biology, Section of Anatomy, Umeå University, Umeå, Sweden.
authors.forename: Jing-Xia
authors.initials: JX
authors.lastname: Liu
authors.affiliation: Department of Clinical Sciences, Ophthalmology, Umeå University, Umeå, Sweden Department of Integrative Medical Biology, Section of Anatomy, Umeå University, Umeå, Sweden.
authors.forename: Fatima
authors.initials: F
authors.lastname: Pedrosa Domellöf
mesh_terms: D000328:Adult; D000368:Aged; D003893:Desmin / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D018656:Muscle Fibers, Fast-Twitch / Q000276:immunology / Q000378:metabolism*; D018995:Myosin Heavy Chains / Q000276:immunology / Q000378:metabolism; D064231:Nestin / Q000378:metabolism*; D009801:Oculomotor Muscles / Q000276:immunology / Q000378:metabolism*; D014746:Vimentin / Q000378:metabolism*
chemical_list: D003893:Desmin; D064231:Nestin; D014746:Vimentin; D018995:Myosin Heavy Chains
keywords: desmin; extraocular muscle; intermediate filament; myosin heavy chain slow tonic; nestin