Human extraocular muscles in ALS
2010 (English)In: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, Vol. 51, no 7, 3494-3501 p.Article in journal (Refereed) Published
PURPOSE. To investigate the general morphology, fiber type content, and myosin heavy chain (MyHC) composition of extraocular muscles (EOMs) from postmortem donors with amyotrophic lateral sclerosis (ALS) and to evaluate whether EOMs are affected or truly spared in this disease. METHODS. EOM and limb muscle samples obtained at autopsy from ALS donors and EOM samples from four control donors were processed for immunohistochemistry with monoclonal antibodies against distinct MyHC isoforms and analyzed by SDS-PAGE. In addition, hematoxylin and eosin staining and nicotinamide tetrazolium reductase (NADH-TR) activity were studied. RESULTS. Wide heterogeneity was observed in the appearance of the different EOMs from each single donor and between donors, irrespective of ALS type or onset. Pathologic morphologic findings in ALS EOMs included presence of atrophic and hypertrophic fibers, either clustered in groups or scattered; increased amounts of connective tissue; and areas of fatty replacement. The population of fibers stained with anti-MyHCslow tonic was smaller than that of MyHCIpositive fibers and was mostly located in the orbital layer in most of the ALS EOM samples, whereas an identical staining pattern for both fiber populations was observed in the control specimens. MyHCembryonic was notably absent from the ALS EOMs. CONCLUSIONS. The EOMs showed signs of involvement with altered fiber type composition, contractile protein content, and cellular architecture. However, when compared to the limb muscles, the EOMs were remarkably preserved. EOMs are a useful model for the study of the pathophysiology of ALS.
Place, publisher, year, edition, pages
Association for Research in Vision and Ophthalmology (ARVO) , 2010. Vol. 51, no 7, 3494-3501 p.
ALS, human extraocular muscles
Research subject Neurology; Ophtalmology; Pathology
IdentifiersURN: urn:nbn:se:umu:diva-35476DOI: 10.1167/iovs.09-5030ISI: 000279047500024PubMedID: 20181843OAI: oai:DiVA.org:umu-35476DiVA: diva2:344434
FunderSwedish Research Council, K2010-62x20399-04-02