Aberrant expression of myogenin in inclusion body myositis: Immunohistochemical studies of transcription factors regulating myogenesis in inflammatory myopathies.
Aberrant expression of myogenin in inclusion body myositis: Immunohistochemical studies of transcription factors regulating myogenesis in inflammatory myopathies.
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包涵体肌炎中肌生成素的异常表达：炎症性肌病中调节肌生成的转录因子的免疫组织化学研究。
DOI：
10.1111/cen3.12000
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Tsuji S.
中科院分区：
文献类型：
--
作者：
Kubota A;Shimizu J;Iwata A;Tsuji S.
目的：研究炎症性肌病中调控肌肉发生的转录因子(Pax7、MyoD1和Mygenin)的免疫组织化学与组织病理学严重程度的关系，以及特发性炎症性肌病(IIM)和包涵体肌炎(IBM)的免疫组织化学结果是否存在差异。每个标本被分为四个组织病理学严重程度等级之一。结果Pax7、MyoD1和Mygenin均显示出特定的核染色模式。此外，在IBM患者的退行性肌纤维内观察到肌生成素阳性的斑块状信号，双重免疫荧光染色显示肌生成素聚集在Aβ42阳性包涵体内。Pax7、MyoD1或mygenin阳性的细胞核数量与组织病理学严重程度相关。在中度至重度组织病理学改变的标本中，IBM患者的再生肌纤维较IIM患者少(45.00±0.022.9个/百肌纤维；IBM，17.7%±17.8个/百肌纤维；P=0.0007)，较少的肌生成素阳性核(IIM，平均4.70%±1.40个/百肌纤维；IBM，4.70%±1.40个/百肌纤维；P=0.0352)。有必要进行进一步的研究，以确定在IBM中是否存在肌生成素的表达受损。
ObjectivesWe aimed to assess the immunohistochemistry of transcription factors that regulate myogenesis (Pax7, MyoD1, and myogenin) in inflammatory myopathies in relation to histopathological severity, and to determine whether there are some differences in immunohistochemical findings between idiopathic inflammatory myopathy (IIM) and inclusion body myositis (IBM).MethodsWe assessed 49 biopsied muscle specimens: 32 from IIM patients, 13 from IBM patients, and four from control subjects. Each specimen was classified into one of four grades of histopathological severity. The numbers of regenerative myofibers and nuclei positive for Pax7, MyoD1, or myogenin were counted.ResultsPax7, MyoD1, and myogenin showed specific nuclear staining patterns. Moreover, myogenin‐positive plaque‐shaped signals were observed within degenerative myofibers in IBM patients, and double immunofluorescence staining showed aggregation of myogenin within Aβ42‐positive inclusion bodies. The number of nuclei positive for Pax7, MyoD1, or myogenin correlated with histopathological severity. In the specimens with moderate to severe histopathological changes, specimens from IBM patients showed less regenerative myofibers (IIM, mean ± SD, 45.0 ± 22.9 per 100 myofibers; IBM, 17.7 ± 7.8 per 100 myofibers;P=0.0007) and less myogenin‐positive nuclei (IIM, mean ± SD, 7.28 ± 3.70 per 100 myofibers; IBM, 4.70 ± 1.40 per 100 myofibers;P=0.0352) than those from IIM patients.ConclusionAberrant localization of myogenin within degenerative myofibers in IBM may be related to the reduced numbers of regenerative fibers and myogenin‐positive nuclei in IBM. Further study is necessary to determine whether the expression of myogenin might be impaired in IBM.