4-octyl itaconate (4-OI) is an anti-inflammatory metabolite that activates the nuclear-factor-E2-related factor 2 (NRF2) signaling. In the current work, we investigated whether 4-OI could affect the production of proinflammatory cytokines in Behcet’s uveitis (BU) and experimental autoimmune uveitis (EAU). Peripheral blood mononuclear cells (PBMCs) of active BU patients and healthy individuals with in vitro 4-OI treatment were performed to assess the influence of 4-OI on the proinflammatory cytokine production. EAU was induced and used for investigating the influence of 4-OI on the proinflammatory cytokine production in vivo. The flow cytometry, qPCR, and ELISA were performed to detect proinflammatory cytokine expression. NRF2 signaling activation was evaluated by qPCR and western blotting (WB). Splenic lymphocyte transcriptome was performed by RNA sequencing. The NRF2 expression by BU patients-derived PBMCs was lower than that by healthy individuals. After treatment with 4-OI, the proportion of Th17 cells, along with the expression of proinflammatory cytokines (IL-17, TNF-α, MCP-1, and IL-6) by PBMCs, were downregulated, and anti-inflammatory cytokine (IL-10) expression was upregulated, although IFN-γ expression was unaffected. The EAU severity was ameliorated by 4-OI in association with a lower splenic Th1/Th17 cell proportion and increased nuclear NRF2 expression. Additionally, 4-OI downregulated a set of 248 genes, which were enriched in pathways of positive regulation of immune responses. The present study shows an inhibitory effect of 4-OI on the proinflammatory cytokine production in active BU patients and EAU mice, possibly mediated through activating NRF2 signaling. These findings suggest that 4-OI could act as a potential therapeutic drug for the treatment and prevention of BU in the future study.

衣康酸 4-辛酯 (4-OI) 是一种抗炎代谢物，可激活核因子 E2 相关因子 2 (NRF2) 信号传导。在目前的工作中，我们研究了 4-OI 是否会影响白塞葡萄膜炎 (BU) 和实验性自身免疫性葡萄膜炎 (EAU) 中促炎细胞因子的产生。对接受体外4-OI 治疗的活动性 BU 患者和健康个体的外周血单核细胞 (PBMC)进行评估，以评估 4-OI 对促炎细胞因子产生的影响。诱导EAU并用于研究4-OI对体内促炎细胞因子产生的影响。采用流式细胞术、qPCR 和 ELISA 检测促炎细胞因子的表达。通过 qPCR 和蛋白质印迹 (WB) 评估 NRF2 信号传导激活。通过RNA测序进行脾淋巴细胞转录组分析。BU 患者来源的 PBMC 的 NRF2 表达低于健康个体。用 4-OI 治疗后，Th17 细胞的比例以及 PBMC 促炎细胞因子（IL-17、TNF-α、MCP-1 和 IL-6）的表达均下调，抗炎细胞因子（尽管 IFN-γ 表达不受影响，但 IL-10 表达上调。4-OI 可改善 EAU 严重程度，并降低脾脏 Th1/Th17 细胞比例和增加核 NRF2 表达。此外，4-OI 下调了一组 248 个基因，这些基因富含免疫反应正向调节途径。本研究表明，4-OI 对活动性 BU 患者和 EAU 小鼠的促炎细胞因子产生具有抑制作用，这可能是通过激活 NRF2 信号传导介导的。这些发现表明，4-OI 在未来的研究中可以作为治疗和预防 BU 的潜在治疗药物。