Premium
Chemokine‐like factor expression in the idiopathic inflammatory myopathies
Author(s) -
Chowdhury M. H.,
Nagai A.,
Terashima M.,
Md Sheikh A.,
Murakawa Y.,
Kobayashi S.,
Yamaguchi S.
Publication year - 2008
Publication title -
acta neurologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.967
H-Index - 95
eISSN - 1600-0404
pISSN - 0001-6314
DOI - 10.1111/j.1600-0404.2007.00990.x
Subject(s) - myogenesis , polymyositis , myocyte , myosin , dermatomyositis , chemokine , myopathy , biology , inflammation , medicine , pathology , endocrinology , chemistry , microbiology and biotechnology , immunology
Objectives – We evaluated the expression of chemokine‐like factor (CKLF) in biopsied muscle fibers in inflammatory myopathies, non‐inflammatory myopathies and neurologically diseased controls. Materials and methods – We studied the expression of CKLF in 15 polymyositis (PM), five dermatomyositis (DM), 15 non‐inflammatory myopathies and nine neurologically diseased patients by immunohistochemistry. Results – Chemokine‐like factor was mostly expressed in small diameter muscle fibers surrounded by infiltrated lymphocytes of inflammatory myopathies patients. Parts of them were also positive for the staining of the developmental form of myosin heavy chain, a maker of regenerating muscle fibers. Thrombin immunoreactivity was observed in endomysium in PM and perimysium in DM. In vitro differentiation study showed a constitutive expression of CKLF in myoblasts that was abolished in myotubes during differentiation process and was induced again by thrombin. Thrombin regulates CKLF expression through protease‐activated receptor‐1 in myotubes. Treatment of a protein kinase C inhibitor partially blocked CKLF expression in myoblasts, while it remarkably inhibited that in myotubes. Conclusion – Chemokine‐like factor expression is differentially regulated in myoblasts and myotubes. Thrombin could be a strong regulator for its expression. As CKLF is immunohistochemically positive in regenerating muscle fibers, we postulate here that CKLF is a useful marker for regenerating muscle fibers in inflammatory myopathies.