Format

Send to

Choose Destination
Am J Pathol. 2000 Apr;156(4):1151-5.

Paired helical filaments of inclusion-body myositis muscle contain RNA and survival motor neuron protein.

Author information

1
University of Southern California Neuromuscular Center, Los Angeles, California 90017-1712, USA.

Abstract

Sporadic inclusion-body myositis (s-IBM) is the most common progressive muscle disease of older persons. Pathologically, the muscle biopsy manifests various degrees of inflammation and specific vacuolar degeneration of muscle fibers characterized by paired helical filaments (PHFs) composed of phosphorylated tau. IBM vacuolated fibers also contain accumulations of several other Alzheimer-characteristic proteins. Molecular mechanisms leading to formation of the PHFs and accumulations of proteins in IBM muscle are not known. We report that the abnormal muscle fibers of IBM contained (i) acridine-orange-positive RNA inclusions that colocalized with the immunoreactivity of phosphorylated tau and (ii) survival motor neuron protein immunoreactive inclusions, which by immuno-electron microscopy were confined to paired helical filaments. This study demonstrates two novel components of the IBM paired helical filaments, which may lead to better understanding of their pathogenesis.

PMID:
10751338
PMCID:
PMC1876899
DOI:
10.1016/S0002-9440(10)64983-8
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center