Department of Rheumatology and Immunology, Xiangya Hospital.
Institute of Rheumatology and Immunology, Central South University, Changsha.
Rheumatology (Oxford). 2021 May 14;60(5):2177-2189. doi: 10.1093/rheumatology/keaa473.
Muscle cell necrosis is the most common pathological manifestation of idiopathic inflammatory myopathies. Evidence suggests that glycolysis might participate in it. However, the mechanism is unclear. This study aimed to determine the role of glycolysis in the muscle damage that occurs in DM/PM.
Mass spectrometry was performed on muscle lesions from DM/PM and control subjects. The expression levels of pyruvate kinase isozyme M2 (PKM2), the nucleotide-binding and oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome and pyroptosis-related genes in muscle tissues or plasma were determined by real-time PCR, western blot analysis, IF and ELISA. In addition, IFNγ was used to stimulate myotubes, and the relationships among PMK2 expression, NLRP3 inflammasome activation and pyroptosis were investigated.
Mass spectrometry and bioinformatics analysis suggested that multiple glycolysis processes, the NLRP3 inflammasome and programmed cell death pathway-related proteins were dysregulated in the muscle tissues of DM/PM. PKM2 and the NLRP3 inflammasome were upregulated and positively correlated in the muscle fibres of DM/PM. Moreover, the pyroptosis-related proteins were increased in muscle tissues of DM/PM and were further increased in PM. The levels of PKM2 in muscle tissues and IL-1β in plasma were high in patients with anti-signal recognition particle autoantibody expression. The pharmacological inhibition of PKM2 in IFNγ-stimulated myotubes attenuated NLRP3 inflammasome activation and subsequently inhibited pyroptosis.
Our study revealed upregulated glycolysis in the lesioned muscle tissues of DM/PM, which activated the NLRP3 inflammasome and leaded to pyroptosis in muscle cells. The levels of PKM2 and IL-1β were high in patients with anti-signal recognition particle autoantibody expression. These proteins might be used as new biomarkers for muscle damage.
肌细胞坏死是特发性炎性肌病最常见的病理表现。有证据表明糖酵解可能参与其中。然而，其机制尚不清楚。本研究旨在确定糖酵解在 DM/PM 肌肉损伤中的作用。
对 DM/PM 和对照受试者的肌肉病变进行质谱分析。通过实时 PCR、western blot 分析、IF 和 ELISA 测定肌肉组织或血浆中丙酮酸激酶同工酶 M2（PKM2）、核苷酸结合寡聚化结构域样受体家族吡咯烷域包含 3（NLRP3）炎症小体和细胞焦亡相关基因的表达水平。此外，用 IFNγ刺激肌管，研究 PMK2 表达、NLRP3 炎症小体激活和细胞焦亡之间的关系。
质谱和生物信息学分析表明，DM/PM 肌肉组织中多种糖酵解过程、NLRP3 炎症小体和程序性细胞死亡途径相关蛋白发生失调。在 DM/PM 的肌纤维中，PKM2 和 NLRP3 炎症小体上调且呈正相关。此外，DM/PM 肌肉组织中细胞焦亡相关蛋白增加，PM 中进一步增加。具有抗信号识别颗粒自身抗体表达的患者肌肉组织中 PKM2 水平和血浆中 IL-1β 水平较高。IFNγ 刺激的肌管中 PKM2 的药理学抑制减弱了 NLRP3 炎症小体的激活，从而抑制了细胞焦亡。
本研究揭示了 DM/PM 病变肌肉组织中糖酵解的上调，激活了 NLRP3 炎症小体，导致肌肉细胞发生细胞焦亡。具有抗信号识别颗粒自身抗体表达的患者中 PKM2 和 IL-1β 水平较高。这些蛋白可能可作为肌肉损伤的新生物标志物。
