Rousselle Anthony, Lodka Dörte, Sonnemann Janis, Kling Lovis, Kettritz Ralph, Schreiber Adrian
Experimental and Clinical Research Center, Max Delbrück Center for Molecular Medicine (MDC) and Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.
Experimental and Clinical Research Center, Max Delbrück Center for Molecular Medicine (MDC) and Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany; Department of Nephrology and Medical Intensive Care Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany.
Kidney Int. 2025 Jun;107(6):1037-1050. doi: 10.1016/j.kint.2025.02.023. Epub 2025 Mar 22.
Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) are systemic autoimmune diseases featuring small blood vessel inflammation and organ damage, including necrotizing crescentic glomerulonephritis (NCGN). Persistent vascular inflammation leads to endothelial and kidney cell necrosis. Ferroptosis is a regulated cell death pathway executed by reactive oxygen species and iron-dependent lipid peroxidation culminating in cell membrane rupture. Here we show that ANCA-activated neutrophils induced endothelial cell (EC) death in vitro that was prevented by ferroptosis inhibition with Ferrostatin-1, Liproxstatin-1 and small inhibiting RNA against the enzyme AcylCoA Synthetase Long Chain Family Member 4 (ACSL4). In contrast, neither necroptosis nor apoptosis inhibition affected EC death. Moreover, both ferroptosis inhibitors alleviated lipid peroxide accumulation in EC. Increased lipid peroxidation was detected in kidney sections of AAV mice by immunohistochemistry. We generated MPO ACSL4 Tie2-Cre mice lacking ACSL4 specifically in EC (ACSL4) to study the significance of endothelial ferroptosis in vivo. ACSL4 chimeric mice, but not control mice (ACSL4), were protected from NCGN in an MPO-AAV bone-marrow transplantation model. These data establish that EC ferroptosis contributes to ANCA-induced glomerulonephritis. However, systemic pharmacological ferroptosis inhibition with Ferrostatin-1 or Liproxstatin-1 did not protect from NCGN in a murine AAV model. Ferrostatin-1 treatment both directly activated T-cell proliferation and indirectly myeloid-mediated T-cell proliferation and polarization in vitro. Conceivably, both effects may cancel the beneficial effect of endothelial ferroptosis inhibition. Mechanistically, we describe the importance of EC ferroptosis for the development of AAV. However, the lack of protection with systemic pharmacological ferroptosis inhibition should discourage clinicians from evaluating this treatment strategy in clinical AAV studies.
抗中性粒细胞胞浆抗体（ANCA）相关血管炎（AAV）是一类以小血管炎症和器官损害为特征的系统性自身免疫性疾病，包括坏死性新月体性肾小球肾炎（NCGN）。持续性血管炎症会导致内皮细胞和肾细胞坏死。铁死亡是一种由活性氧和铁依赖性脂质过氧化作用介导的程序性细胞死亡途径，最终导致细胞膜破裂。在此，我们发现ANCA激活的中性粒细胞在体外可诱导内皮细胞（EC）死亡，而铁死亡抑制剂Ferrostatin-1、Liproxstatin-1以及针对酰基辅酶A合成酶长链家族成员4（ACSL4）的小干扰RNA可阻止这种死亡。相比之下，坏死性凋亡或凋亡抑制均不影响内皮细胞死亡。此外，两种铁死亡抑制剂均可减轻内皮细胞中脂质过氧化物的积累。通过免疫组化在AAV小鼠的肾组织切片中检测到脂质过氧化增加。我们构建了特异性在内皮细胞（EC）中缺乏ACSL4的MPO ACSL4 Tie2-Cre小鼠（ACSL4），以研究体内内皮细胞铁死亡的意义。在MPO-AAV骨髓移植模型中，ACSL4嵌合小鼠而非对照小鼠（ACSL4）可免受NCGN的影响。这些数据表明，内皮细胞铁死亡参与了ANCA诱导的肾小球肾炎。然而，在小鼠AAV模型中，用Ferrostatin-1或Liproxstatin-1进行全身性药理学铁死亡抑制并不能预防NCGN。Ferrostatin-1治疗在体外可直接激活T细胞增殖，并间接促进髓系细胞介导的T细胞增殖和极化。可以想象，这两种作用可能会抵消内皮细胞铁死亡抑制的有益作用。从机制上讲，我们阐述了内皮细胞铁死亡在AAV发病过程中的重要性。然而，全身性药理学铁死亡抑制缺乏保护作用，这应使临床医生在临床AAV研究中不再考虑评估这种治疗策略。
