RESULTS: We investigated the expression and the cellular localization of RNA polymerase II (RNAPII)-associated proteins (RPAPs) in muscle biopsies from patients with genetically proven and sporadic MFMs. Our data demonstrated that RPAP2, and to a lesser extent GPN1/RPAP4, are accumulated focally in the cytoplasm of MFM muscle fibres in which they co-localize with POLR2A/RPB1, the largest subunit of RNAPII, and correspond to αB-cystallin deposits in distribution and staining intensity. No abnormal staining for RPAP2 has been observed in muscle of patients with central cores, minicores and neurogenic target fibres.
CONCLUSIONS: Together, these findings could provide new insights into the molecular pathogenesis of MFMs and suggest that RPAP2 immunostaining can be a useful diagnostic tool to depict protein aggregates in MFMs.
结果:我们研究了RNA聚合酶II(RNAPII)相关蛋白(RPAP)在患有遗传证明和散发性MFM的患者的肌肉活检中的表达和细胞定位。我们的数据表明,RPAP2,以及在较小程度上GPN1/RPAP4,在MFM肌纤维的细胞中聚集,它们与最大的RNRAP2A/PB1共同定位在分布和染色强度上对应于αB-cystallin沉积物。在有中央核心的患者的肌肉中未观察到RPAP2的异常染色,微小核和神经源性靶纤维。
结论:一起,这些发现可以为了解MFM的分子发病机制提供新的见解,并表明RPAP2免疫染色可以成为描述MFM中蛋白质聚集体的有用诊断工具。