Kuru Satoshi, Inukai Akira, Kato Takashi, Liang Yideng, Kimura Seigo, Sobue Gen
Department of Neurology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Japan.
Acta Neuropathol. 2003 Mar;105(3):217-24. doi: 10.1007/s00401-002-0635-4. Epub 2002 Nov 22.
The expression level of tumor necrosis factor (TNF)-alpha is elevated in idiopathic inflammatory myopathies and Duchenne muscular dystrophy (DMD), but the precise role of TNF-alpha is unknown. To elucidate the possible role of TNF-alpha, we investigated the expression of TNF-alpha and its receptor in polymyositis (PM), dermatomyositis (DM), and DMD using in situ hybridization (ISH) and immunohistochemistry. We showed that TNF-alpha mRNA and protein were present in muscle fibers. TNF-alpha-positive fibers were observed in all cases of PM, DM and DMD, but were rare or absent in neurogenic disorders and normal controls. The proportion of TNF-alpha-positive fiber showed a significant positive correlation with the proportion of regenerating fibers that were positive for the developmental form of myosin heavy chain (MHC-d). The number of TNF receptor-positive fibers was small. Some muscle fibers expressed both TNF-alpha and its receptor simultaneously. Our results indicate that TNF-alpha is produced and expressed by muscle fibers and associated with muscle regeneration.
肿瘤坏死因子（TNF）-α在特发性炎性肌病和杜兴氏肌营养不良症（DMD）中表达水平升高，但TNF-α的确切作用尚不清楚。为了阐明TNF-α的可能作用，我们使用原位杂交（ISH）和免疫组织化学方法研究了TNF-α及其受体在多发性肌炎（PM）、皮肌炎（DM）和DMD中的表达。我们发现肌肉纤维中存在TNF-α mRNA和蛋白。在所有PM、DM和DMD病例中均观察到TNF-α阳性纤维，但在神经源性疾病和正常对照中罕见或不存在。TNF-α阳性纤维的比例与肌球蛋白重链发育形式（MHC-d）阳性的再生纤维比例呈显著正相关。TNF受体阳性纤维数量较少。一些肌肉纤维同时表达TNF-α及其受体。我们的结果表明，TNF-α由肌肉纤维产生和表达，并与肌肉再生相关。
