Open AccessInvolvement of Clusterin and the Aggresome in Abnormal Protein Deposits in Myofibrillar Myopathies and Inclusion Body Myositis
Author(s) -
Ferrer I.,
Carmona M.,
Blanco R.,
Moreno D.,
TorrejónEscribano B.,
Olivé M.
Publication year - 2005
Publication title -
brain pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.986
H-Index - 132
eISSN - 1750-3639
pISSN - 1015-6305
DOI - 10.1111/j.1750-3639.2005.tb00504.x
Subject(s) - aggresome , clusterin , inclusion body myositis , cytoplasmic inclusion , pathology , myofibril , biology , desmin , microbiology and biotechnology , chemistry , cytoplasm , vimentin , immunohistochemistry , myositis , anatomy , biochemistry , medicine , ubiquitin , apoptosis , gene
Myofibrillar myopathies (MM) are characterized morphologically by the presence of non‐hyaline structures corresponding to foci of dissolution of myofibrils, and hyaline lesions composed of aggregates of compacted and degraded myofibrillar elements. Inclusion body myositis (IBM) is characterized by the presence of rimmed vacuoles, eosinophilic inclusions in the cytoplasm, rare intranuclear inclusions, and by the accumulation of several abnormal proteins. Recent studies have demonstrated impaired proteasomal expression and activity in MM and IBM, thus accounting, in part, for the abnormal protein accumulation in these diseases. The present study examines other factors involved in protein aggregation in MM and IBM. Clusterin is a multiple‐function protein which participates in Aβ‐amyloid, PrP res and α‐synuclein aggregation in Alzheimer disease, prionopathies and α‐synucleinopathies, respectively. γ‐Tubulin is present in the centrosome and is an intracellular marker of the aggresome. Moderate or strong clusterin immunoreactivity has been found in association with abnormal protein deposits, as revealed by immunohistochemistry, single and double‐labeling immunofluorescence and confocal microscopy, in MM and IBM, and in target structures in denervation atrophy. γ‐Tubulin has also been observed in association with abnormal protein deposits in MM, IBM, and in target fibers in denervation atrophy. These morphological findings are accompanied by increased expression of clusterin and γ‐tubulin in muscle homogenates of MM and IBM cases, as revealed by gel electrophoresis and Western blots. Together, these observations demonstrate involvement of clusterin in protein aggregates, and increased expression of aggresome markers in association with abnormal protein inclusions in MM and IBM and in targets, as crucial events related with the pathogenesis of abnormal protein accumulation and degradation in these muscular diseases.