Pharmazentrum Frankfurt / ZAFES, Goethe University, University Hospital Frankfurt, Frankfurt am Main, Germany.
Pharmazentrum Frankfurt / ZAFES, Goethe University, University Hospital Frankfurt, Frankfurt am Main, Germany.
J Autoimmun. 2024 Jun;146:103229. doi: 10.1016/j.jaut.2024.103229. Epub 2024 Apr 22.
Primary sclerosing cholangitis (PSC) is an (auto)immune-mediated cholestatic liver disease with a yet unclear etiology. Increasing evidence points to an involvement of neutrophils in chronic liver inflammation and cirrhosis but also liver repair. Here, we investigate the role of the neutrophil extracellular trap (NET) component myeloperoxidase (MPO) and the therapeutic potential of DNase I and of neutrophil elastase (NE) inhibitor GW311616A on disease outcome in the multidrug resistance 2 knockout (Mdr2) mouse, a PSC animal model. Initially, we observed the recruitment of MPO expressing cells and the formation of NETs in liver biopsies of PSC patients and in Mdr2 livers. Furthermore, sera of Mdr2 mice contained perinuclear anti-neutrophil cytoplasmic antibody (p-ANCA)-like reactivity similar to PSC patient sera. Also, hepatic NE activity was significantly higher in Mdr2 mice than in wild type littermates. Flow cytometry analyses revealed that during disease development a highly active neutrophil subpopulation established specifically in the liver of Mdr2 mice. However, absence of their MPO activity, as in MPO-deficient Mdr2 mice, showed no effect on hepatobiliary disease severity. In contrast, clearance of extracellular DNA by DNase I reduced the frequency of liver-resident neutrophils, plasmacytoid dendritic cells (pDCs) and CD103 conventional DCs and decreased cholangiocyte injury. Combination of DNase I with a pDC-depleting antibody was additionally hepatocyte-protective. Most importantly, GW311616A, an orally bioavailable inhibitor of human NE, attenuated hepatobiliary injury in a TNFα-dependent manner and damped hyperproliferation of biliary epithelial cells. Further, hepatic immigration and activity of CD11b DCs as well as the secretion of IFNγ by hepatic CD4 and CD8 T cells were reduced. Our findings delineate neutrophils as important participants in the immune cell crosstalk that drives cholestatic liver disease and identify NET components as potential therapeutic targets.
原发性硬化性胆管炎（PSC）是一种（自身）免疫介导的胆汁淤积性肝病，其病因尚不清楚。越来越多的证据表明中性粒细胞参与慢性肝炎症和肝硬化，但也参与肝修复。在这里，我们研究了中性粒细胞胞外诱捕网（NET）成分髓过氧化物酶（MPO）以及脱氧核糖核酸酶 I 和中性粒细胞弹性蛋白酶（NE）抑制剂 GW311616A 在多药耐药 2 敲除（Mdr2）小鼠（PSC 动物模型）疾病结果中的作用。最初，我们观察到 PSC 患者的肝活检和 Mdr2 肝脏中表达 MPO 的细胞的募集和 NET 的形成。此外，Mdr2 小鼠的血清中含有类似于 PSC 患者血清的核周抗中性粒细胞胞质抗体（p-ANCA）样反应性。此外，Mdr2 小鼠的肝 NE 活性明显高于野生型同窝小鼠。流式细胞术分析显示，在疾病发展过程中，一种高度活跃的中性粒细胞亚群特异性建立在 Mdr2 小鼠的肝脏中。然而，缺乏 MPO 活性，如在 MPO 缺陷型 Mdr2 小鼠中，对肝胆疾病严重程度没有影响。相反，脱氧核糖核酸酶 I 清除细胞外 DNA 减少了肝固有中性粒细胞、浆细胞样树突状细胞（pDC）和 CD103 常规树突状细胞的频率，并减少了胆管细胞损伤。DNase I 与耗竭 pDC 的抗体联合使用还具有肝细胞保护作用。最重要的是，GW311616A，一种人 NE 的口服生物可利用抑制剂，以 TNFα 依赖的方式减轻肝胆损伤，并抑制胆管上皮细胞的过度增殖。此外，肝内 CD11b DC 的迁移和活性以及肝 CD4 和 CD8 T 细胞分泌的 IFNγ 减少。我们的研究结果描绘了中性粒细胞作为驱动胆汁淤积性肝病的免疫细胞串扰的重要参与者，并确定了 NET 成分作为潜在的治疗靶点。
