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Transforming growth factor‐β signaling is upregulated in sporadic inclusion body myositis
Author(s) -
Noda Seiya,
Koike Haruki,
Maeshima Shinya,
Nakanishi Hirotaka,
Iijima Masahiro,
Matsuo Koji,
Kimura Seigo,
Katsuno Masahisa,
Sobue Gen
Publication year - 2017
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.25405
Subject(s) - transforming growth factor , inclusion body myositis , western blot , downregulation and upregulation , immunohistochemistry , receptor , myositis , signal transduction , dermatomyositis , myocyte , endocrinology , biology , medicine , pathology , microbiology and biotechnology , biochemistry , gene
In this study we aimed to determine whether transforming growth factor‐β (TGF‐β) signaling is dysregulated in sporadic inclusion body myositis (sIBM) muscle samples. Methods We examined TGF‐β signaling markers in muscle samples from 24 sIBM patients and compared them with those from 10 dermatomyositis (DM) patients using immunohistochemistry and Western blot analyses. Results Compared with the DM muscle fibers, the sIBM muscle fibers exhibited greater TGF‐β, TGF‐β receptor type I (TβRI), and TGF‐β receptor type II (TβRII) immunoreactivity in the cytoplasm, as well as greater phosphorylated Smad2 (pSmad2) immunoreactivity in the myonuclei. The signal intensities of TGF‐β, TβRI, and TβRII immunoreactivity correlated significantly with muscle fiber cross‐sectional areas. Western blot analyses indicated higher expression levels of TGF‐β, TβRI, TβRII, and pSmad2 in the sIBM muscle samples than in the DM muscle samples. Conclusions These data indicate that upregulation of TGF‐β signaling may be an important molecular event in sIBM. Muscle Nerve 55: 741–747, 2017