TY - JOUR
T1 - Expression of transglutaminase 2 does not differentiate focal myositis from generalized inflammatory myopathies
AU - Macaione, V.
AU - Aguennouz, M.
AU - Mazzeo, A.
AU - De Pasquale, M. G.
AU - Russo, M.
AU - Toscano, A.
AU - De Luca, G.
AU - Di Giorgio, R. M.
AU - Vita, G.
AU - Rodolico, C.
PY - 2008/6
Y1 - 2008/6
N2 - Objectives - Idiopathic inflammatory myopathies (IIM), including dermatomyositis (DM), polymyositis (PM), sporadic inclusion-body myositis (s-IBM) and focal myositis (FM) are a heterogeneous group of autoimmune disorders of skeletal muscle. An increased transglutaminase 2 (TG2) expression has been found in DM, PM and s-IBM. The aim of our study was to investigate TG2 expression in FM in comparison with other IIM. Materials and methods - We re-examined tissue material we have gathered in the course of our previous studies on IIM, investigating muscle expression of TG2 in patients with FM in comparison with DM, PM and s-IBM using immunocytochemistry and real-time RT-PCR. Results - Immunocytochemistry revealed an increased TG2 signal in endomysial vessels, in atrophic and degenerating/regenerating muscle fibres in PM, DM, s-IBM and FM; in s-IBM, some vacuoles were immunostained too. Real-time RT-PCR study confirmed a significantly increased expression of TG2 in all IIM muscles examined. Conclusions - Our study demonstrates the presence of TG2 in FM muscles. The study suggests that TG2 expression does not represent a distinctive marker to differentiate FM from generalized IIM. TG2 over-expression in inflamed skeletal muscle does not seem have a pathogenetic role in such a disease, but it could represent a way to contain the inflammatory process.
AB - Objectives - Idiopathic inflammatory myopathies (IIM), including dermatomyositis (DM), polymyositis (PM), sporadic inclusion-body myositis (s-IBM) and focal myositis (FM) are a heterogeneous group of autoimmune disorders of skeletal muscle. An increased transglutaminase 2 (TG2) expression has been found in DM, PM and s-IBM. The aim of our study was to investigate TG2 expression in FM in comparison with other IIM. Materials and methods - We re-examined tissue material we have gathered in the course of our previous studies on IIM, investigating muscle expression of TG2 in patients with FM in comparison with DM, PM and s-IBM using immunocytochemistry and real-time RT-PCR. Results - Immunocytochemistry revealed an increased TG2 signal in endomysial vessels, in atrophic and degenerating/regenerating muscle fibres in PM, DM, s-IBM and FM; in s-IBM, some vacuoles were immunostained too. Real-time RT-PCR study confirmed a significantly increased expression of TG2 in all IIM muscles examined. Conclusions - Our study demonstrates the presence of TG2 in FM muscles. The study suggests that TG2 expression does not represent a distinctive marker to differentiate FM from generalized IIM. TG2 over-expression in inflamed skeletal muscle does not seem have a pathogenetic role in such a disease, but it could represent a way to contain the inflammatory process.
KW - Focal myositis
KW - Inflammatory myopathies
KW - Transglutaminase 2
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UR - http://www.scopus.com/inward/citedby.url?scp=43149118991&partnerID=8YFLogxK
U2 - 10.1111/j.1600-0404.2007.00957.x
DO - 10.1111/j.1600-0404.2007.00957.x
M3 - Article
C2 - 18005224
AN - SCOPUS:43149118991
SN - 0001-6314
VL - 117
SP - 393
EP - 398
JO - Acta Neurologica Scandinavica
JF - Acta Neurologica Scandinavica
IS - 6
ER -