Wang Gangan, Dong Yixin, Qiao Xiangyu, Jia Chunyu, Wang Jiahui, Chen Gang, Zheng Ke, Jiang Chengyu, Li Xuemei
Department of Nephrology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
State Key Laboratory of Common Mechanism Research for Major Diseases, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
Kidney Dis (Basel). 2025 May 9;11(1):450-468. doi: 10.1159/000546343. eCollection 2025 Jan-Dec.
Neutrophil extracellular traps (NETs) contribute to inflammation and are implicated in autoimmune diseases; however, their role in IgA nephropathy (IgAN) remains unclear. This study aimed to investigate the involvement of NETosis in IgAN and its impact on renal injury and mesangial cell function, utilizing patient samples, mouse models, and in vitro assays.
RNA sequencing was performed on peripheral blood mononuclear cells (PBMCs) from IgAN patients to identify differentially expressed genes (DEGs) and NETosis-related pathways. An IgAN mouse model was established using bovine serum albumin, carbon tetrachloride, and lipopolysaccharide. Mice were treated with the peptidyl arginine deiminase-4 inhibitor GSK484 to evaluate the effects of NETosis inhibition. In vitro assays assessed the impact of NETosis on mesangial cells.
RNA sequencing identified 905 DEGs in IgAN patients, with significant enrichment in neutrophil and NETosis pathways. Serum levels of NETosis markers - citrullinated histone H3 (CitH3), myeloperoxidase (MPO), and neutrophil elastase - were elevated in IgAN patients, with CitH3 levels correlating with Gd-IgA1. Inhibiting NETosis with GSK484 reduced CitH3 levels in IgAN mice and improved clinical outcomes, including decreased proteinuria and increased serum albumin. Histological analysis revealed reduced mesangial proliferation. In vitro, NETosis enhanced tumor necrosis factor-α (TNF-α) release from mesangial cells, an effect that was mitigated by GSK484. RNA-seq analysis of kidneys from GSK484-treated IgAN mice also revealed significant alterations in the PPAR signaling pathway. Additionally, TNF-α treatment of mesangial cells resulted in reduced PPARα expression, suggesting that NETosis may modulate this pathway through the release of TNF-α by mesangial cells.
Our findings demonstrate that NETosis is upregulated in IgAN and plays a key role in its pathogenesis by promoting inflammatory cytokine release. Inhibition of NETosis improves both clinical and pathological outcomes, highlighting its potential as a therapeutic approach for managing IgAN.
中性粒细胞胞外陷阱（NETs）参与炎症反应，并与自身免疫性疾病有关；然而，它们在IgA肾病（IgAN）中的作用仍不清楚。本研究旨在利用患者样本、小鼠模型和体外试验，探讨NETosis在IgAN中的作用及其对肾损伤和系膜细胞功能的影响。
对IgAN患者的外周血单个核细胞（PBMCs）进行RNA测序，以鉴定差异表达基因（DEGs）和NETosis相关途径。使用牛血清白蛋白、四氯化碳和脂多糖建立IgAN小鼠模型。用肽基精氨酸脱氨酶-4抑制剂GSK484处理小鼠，以评估抑制NETosis的效果。体外试验评估NETosis对系膜细胞的影响。
RNA测序在IgAN患者中鉴定出905个DEGs，在中性粒细胞和NETosis途径中显著富集。IgAN患者血清中NETosis标志物——瓜氨酸化组蛋白H3（CitH3）、髓过氧化物酶（MPO）和中性粒细胞弹性蛋白酶水平升高，CitH3水平与Gd-IgA1相关。用GSK484抑制NETosis可降低IgAN小鼠的CitH3水平，并改善临床结局，包括减少蛋白尿和增加血清白蛋白。组织学分析显示系膜增生减少。在体外，NETosis增强了系膜细胞中肿瘤坏死因子-α（TNF-α）的释放，GSK484可减轻这种作用。对用GSK484处理的IgAN小鼠肾脏进行RNA-seq分析还显示，PPAR信号通路有显著改变。此外，用TNF-α处理系膜细胞会导致PPARα表达降低，这表明NETosis可能通过系膜细胞释放TNF-α来调节该途径。
我们的研究结果表明，NETosis在IgAN中上调，并通过促进炎性细胞因子释放在其发病机制中起关键作用。抑制NETosis可改善临床和病理结局，突出了其作为治疗IgAN的潜在方法的可能性。
