坏死样细胞死亡已被认为与多种炎症性疾病有关，包括肿瘤坏死因子-α（TNF-α）诱导的全身炎症反应综合征（SIRS）。二甲基富马酸酯（DMF）是治疗复发缓解型多发性硬化症（RRMS）的一线药物，已被证明对多种炎症性疾病有效。然而，目前尚不清楚DMF是否可以抑制坏死样细胞死亡并对抗SIRS。在这项研究中，我们发现DMF显著抑制了不同坏死诱导的巨噬细胞的坏死样细胞死亡。DMF可强烈抑制受体相互作用丝氨酸/苏氨酸激酶1（RIPK1）和RIPK3的自动磷酸化以及下游MLKL的磷酸化和寡聚化。随着坏死性信号的抑制，DMF阻断了坏死诱导的线粒体逆向电子传递（RET），这与其亲电性特性有关。几个著名的抗逆向电子传递试剂也明显抑制了RIPK1-RIPK3-MLKL轴的活化，伴随着坏死细胞死亡的减少，表明RET在坏死性信号中起着重要作用。DMF和其他抗逆向电子传递试剂抑制了RIPK1和RIPK3的泛素化，并减弱了坏死体的形成。此外，DMF的口服给药显著减轻了TNF-α诱导的小鼠SIRS的严重程度。与此一致，DMF减轻了TNF-α诱导的盲肠，子宫和肺损伤，伴随着RIPK3-MLKL信号的减弱。综上所述，DMF是一种新的抑制坏死样细胞死亡的药物，通过阻止线粒体RET来抑制RIPK1-RIPK3-MLKL轴。我们的研究突显了DMF在治疗与SIRS相关的疾病方面的潜在治疗应用。 © 2023 The Authors。发表于Elsevier Ltd。版权所有。

Necroptosis has been implicated in various inflammatory diseases including tumor-necrosis factor-α (TNF-α)-induced systemic inflammatory response syndrome (SIRS). Dimethyl fumarate (DMF), a first-line drug for treating relapsing-remitting multiple sclerosis (RRMS), has been shown to be effective against various inflammatory diseases. However, it is still unclear whether DMF can inhibit necroptosis and confer protection against SIRS. In this study, we found that DMF significantly inhibited necroptotic cell death in macrophages induced by different necroptotic stimulations. Both the autophosphorylation of receptor-interacting serine/threonine kinase 1 (RIPK1) and RIPK3 and the downstream phosphorylation and oligomerization of MLKL were robustly suppressed by DMF. Accompanying the suppression of necroptotic signaling, DMF blocked the mitochondrial reverse electron transport (RET) induced by necroptotic stimulation, which was associated with its electrophilic property. Several well-known anti-RET reagents also markedly inhibited the activation of the RIPK1-RIPK3-MLKL axis accompanied by decreased necrotic cell death, indicating a critical role of RET in necroptotic signaling. DMF and other anti-RET reagents suppressed the ubiquitination of RIPK1 and RIPK3, and they attenuated the formation of necrosome. Moreover, oral administration of DMF significantly alleviated the severity of TNF-α-induced SIRS in mice. Consistent with this, DMF mitigated TNF-α-induced cecal, uterine, and lung damage accompanied by diminished RIPK3-MLKL signaling. Collectively, DMF represents a new necroptosis inhibitor that suppresses the RIPK1-RIPK3-MLKL axis through blocking mitochondrial RET. Our study highlights DMF's potential therapeutic applications for treating SIRS-associated diseases.Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.