Contribution of Necroptosis to Myofiber Death in Idiopathic Inflammatory Myopathies
Contribution of Necroptosis to Myofiber Death in Idiopathic Inflammatory Myopathies
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DOI：
10.1002/art.42071
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发表时间：
2022-05-13
影响因子：
13.3
通讯作者：
Wang, Guo-Chun
中科院分区：
文献类型：
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作者：
Peng, Qing-Lin;Zhang, Ya-Mei;Wang, Guo-Chun
目的肌纤维坏死是特发性炎性肌病（IIMs）的一个重要病理特征，其分子机制在很大程度上尚不清楚。坏死下垂是最近发现的一种受调节的坏死细胞死亡形式，其激活可能具有重要的生物学后果。本研究旨在探讨坏死性上睑下垂在IIM肌肉损伤中的作用。方法采用Western blot和免疫组化方法检测26例IIM患者和4例健康对照者中受体相互作用蛋白3 （RIP-3）和混合谱系激酶结构域样蛋白（MLKL）的表达以及坏死相关损伤相关的分子模式分子。采用肿瘤坏死因子（Tumor necrosis factor， TNF）刺激培养的C2C12成肌细胞，体外研究坏死坏死与C2C12细胞死亡的关系。结果与健康对照组相比，IIM患者肌肉组织中RIP-3和MLKL蛋白及其磷酸化形式的表达显著增加。RIP-3和MLKL蛋白的表达水平与IIM患者肌肉损伤的严重程度相关。在IIM患者的肌肉活检组织中观察到具有高迁移率组盒染色体蛋白1的MLKL在坏死性肌纤维中的显著共定位。用TNF和一种泛caspase抑制剂Z-VAD刺激C2C12成肌细胞，导致坏死下垂过度激活，坏死细胞死亡显著增加。采用坏死他汀-1抑制坏死下垂或敲低MLKL表达的策略均可成功阻止坏死下垂诱导的C2C12细胞死亡。结论过度激活的坏死性上睑下垂导致IIMs的肌肉损伤，提示坏死性上睑下垂抑制剂可能是IIMs治疗的新靶点。
Objective Myofiber necrosis is a significant pathologic characteristic of idiopathic inflammatory myopathies (IIMs), and its molecular mechanism is largely unknown. Necroptosis is a recently identified form of regulated necrotic cell death, and its activation might have crucial biologic consequences. The aim of the present study was to investigate the role of necroptosis in IIM muscle damage. Methods Western blot and immunohistochemistry analyses were performed to examine the expression of receptor-interacting protein 3 (RIP-3) and mixed-lineage kinase domain-like (MLKL) proteins in 26 IIM patients and 4 healthy controls, as well as necroptosis-related damage-associated molecular pattern molecules. Tumor necrosis factor (TNF) was used to stimulate cultured C2C12 myoblasts, and the involvement of necroptosis in cell death of C2C12 cells was studied in vitro. Results The expression of RIP-3 and MLKL proteins and their phosphorylated forms was significantly increased in the muscle tissue of IIM patients compared to that of healthy controls. The expression levels of RIP-3 and MLKL proteins were associated with the severity of muscle damage in patients with IIM. Significant colocalization of MLKL with high mobility group box chromosomal protein 1 in necrotizing myofibers was observed in muscle biopsy tissue from patients with IIM. Stimulation of C2C12 myoblasts with TNF and a pan-caspase inhibitor, Z-VAD, resulted in the overactivation of necroptosis and significantly increased necrotic cell death. Strategies involving either inhibition of necroptosis with necrostatin-1 or knockdown of MLKL expression successfully prevented necroptosis-induced cell death of C2C12 cells. Conclusion These findings demonstrate that overactivated necroptosis contributes to muscle damage in IIMs and suggest that necroptosis inhibitors could represent a new therapeutic target in the treatment of IIMs.