目的 研究S100钙结合蛋白A8（S100 calcium-binding protein A8，S100A8）调控Toll样受体4（Toll-like receptor 4，TLR4）/核因子-κB（nuclear factor-κB，NF-κB）通路在溃疡性结肠炎（ulcerative colitis，UC）铁死亡中的作用以及雷公藤多苷（Tripterygium wilfordii polycoride，TWP）治疗UC的作用机制。方法 用脂多糖（lipopolysaccharides，LPS）和铁死亡抑制剂ferrostatin-1（Fer-1）联合干预THP-1细胞，检测炎症和铁死亡指标。构建S100A8敲减（S100A8 knock-down，S100A8-KD）细胞模型，LPS干预后检测TLR4/NF-κB通路、炎症因子和铁死亡指标。构建S100A8敲除（S100A8 knock-out，S100A8-KO）小鼠模型，葡聚糖硫酸钠（dextran sodium sulfate，DSS）诱导结肠炎症，监测小鼠情况并检测相关指标。在细胞实验和野生型（wild type，WT）小鼠中评价TWP的药效。结果 细胞实验结果显示，Fer-1干预、敲减S100A8及TWP干预均能增加THP-1细胞铁死亡后的细胞活力（P＜0.05、0.001），降低Fe²⁺、丙二醛（malondialdehyde，MDA）、活性氧（reactive oxygen species，ROS）水平（P＜0.01、0.001），降低前列腺素内过氧化物合酶2（prostaglandin-endoperoxide synthase 2，PTGS2）、铁蛋白重链（ferritin heavy chain，FTH）、p53、TLR4、NF-κB、肿瘤坏死因子-α（tumor necrosis factor-α，TNF-α）、白细胞介素-1β（interleukin-1β，IL-1β）表达（P＜0.05、0.01、0.001），增加谷胱甘肽过氧化物酶4（glutathione peroxidase 4，GPX4）、溶质载体家族7成员11（solute carrier family 7 member 11，SLC7A11）表达（P＜0.05、0.01、0.001），并且TWP的作用呈剂量相关性。动物实验结果显示，与WT模型组比较，S100A8-KO模型组与WT-TWP组小鼠体质量下降幅度、疾病活动指数（disease activity index，DAI）、结肠长度缩短、结肠病理情况均明显改善（P＜0.05、0.01、0.001），PTGS2、FTH、p53、TLR4、NF-κB、TNF-α、IL-1β表达降低（P＜0.05、0.01、0.001），GPX4、SLC7A11表达增加（P＜0.05、0.001）。结论 TWP能减轻UC肠道炎症反应，其机制与调控S100A8/TLR4/NF-κB通路进而抑制结肠铁死亡有关。

Objective To investigate the effect of S100 calcium-binding protein A8 (S100A8) on regulating Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) pathway in ferroptosis associated with ulcerative colitis (UC), as well as the therapeutic mechanism of Tripterygium wilfordii polycoride (TWP) in treatment of UC. Methods THP-1 cells were treated with LPS and Fer-1 to detect inflammatory and ferroptosis-related indicators. An S100A8 knock-down (S100A8-KD) cell model was constructed, and after LPS intervention, TLR4/NF-κB pathway, inflammatory cytokines and ferroptosis-related indicators were detected. An S100A8 knock-out (S100A8-KO) mouse model was constructed, and colitis was induced by dextran sodium sulfate (DSS), the general condition of mice was monitored, and relevant indicators were detected. The therapeutic effects of TWP were evaluated in cell experiments and wild-type (WT) mice. Results The results of cell experiments showed that Fer-1 treatment, S100A8 knockdown and TWP intervention all increased cell viability after ferroptosis in THP-1 cells (P < 0.05, 0.001), levels of Fe²⁺, malondialdehyde (MDA) and reactive oxygen species (ROS) were decreased (P < 0.01, 0.001), expressions of prostaglandin-endoperoxide synthase 2 (PTGS2), ferritin heavy chain (FTH), p53, TLR4, NF-κB, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were reduced (P < 0.05, 0.01, 0.001), expressions of glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11) were increased (P < 0.05, 0.01, 0.001). Moreover, the effect of TWP was dose-dependent. The results of animal experiments showed that compared with WT model group, S100A8-KO model group and WT-TWP group exhibited significantly reduced body weight loss, disease activity index (DAI), colonic shortening, and improved colonic pathological conditions (P < 0.05, 0.01, 0.001), expressions of PTGS2, FTH, p53, TLR4, NF-κB, TNF-α and IL-1β were decreased (P < 0.05, 0.01, 0.001), while expressions of GPX4 and SLC7A11 were increased (P < 0.05, 0.001). Conclusion TWP could alleviate intestinal inflammatory responses in UC, and its mechanism is related to the regulation of S100A8/TLR4/NF-κB pathway to inhibit colon ferroptosis.

R285.5

国家自然科学基金资助项目（81973617）；杭州市红十字会医院青年基金资助项目（HHQN2024001）；浙江中医药大学研究生科学研究基金项目（2022YKJ02）