Accumulation of autophagosome cargo protein p62 is common in idiopathic inflammatory myopathies.
Clin Exp Rheumatol
; 39(2): 351-356, 2021.
Article
em En
| MEDLINE
| ID: mdl-32896253
OBJECTIVES: The subsarcolemmal accumulation of p62 aggregates in myofibres has been proposed to be characteristic of sporadic inclusion body myositis (sIBM). The objective of this study was to analyse the patterns and prevalence of p62 immunostaining and to quantitate p62 gene expression in muscle biopsies from a large number of patients with different types of myopathic and neurogenic disorders. METHODS: For the p62 immunostaining analysis, all patients with a muscle biopsy immunostained for p62 at the Johns Hopkins Neuromuscular Pathology Laboratory from 2013 to 2017 were included (n=303). The prevalence and pattern of p62 immunostaining were compared between patients with histologically normal muscle (n=29), inflammatory myopathies (n=136), non-inflammatory myopathies (n=53), and neurogenic disorders (n=85). p62 expression levels were analysed using an existing RNAseq dataset including data from dermatomyositis (DM; n=39), immune-mediated necrotising myopathy (IMNM; n=49), antisynthetase syndrome (AS; n=18), and sIBM (n=23) patients as well as 20 histologically normal muscle biopsies. RESULTS: p62 staining was absent in normal biopsies, but present in biopsies from those with polymyositis (29%), non-inflammatory myopathies (all <31%), neurogenic disorders (31%), dermatomyositis (57%), sIBM (92%) and IMNM (87%). In all diseases studied, p62 accumulation was more prevalent in biopsies with more severe muscle damage. sIBM biopsies had decreased p62 expression levels compared to the other groups (corrected p<0.04). CONCLUSIONS: p62 accumulation is a general response to muscle injury and not a specific marker for sIBM. Also, in sIBM, p62 RNA levels are decreased, suggesting that, in this disease, p62 aggregation is not due to overexpression.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Doenças Autoimunes
/
Polimiosite
/
Miosite de Corpos de Inclusão
/
Miosite
Tipo de estudo:
Risk_factors_studies
Limite:
Humans
Idioma:
En
Revista:
Clin Exp Rheumatol
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Espanha