Abstract：
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.
摘要：
4-辛基衣康酸（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Behcet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。进行活性BU患者和健康个体的外周血单核细胞（PBMC）体外4-OI治疗以评估4-OI对促炎细胞因子产生的影响。EAU被诱导并用于研究4-OI对体内促炎细胞因子产生的影响。流式细胞术，qPCR,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。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，随着促炎细胞因子(IL-17，TNF-α，MCP-1和IL-6)通过PBMC，被下调，抗炎细胞因子（IL-10）表达上调，尽管IFN-γ表达不受影响。4-OI改善了EAU的严重程度，并降低了脾Th1/Th17细胞比例，并增加了核NRF2的表达。此外,4-OI下调了一组248个基因，它们富含免疫应答的正向调节途径。本研究显示4-OI对活性BU患者和EAU小鼠的促炎细胞因子产生的抑制作用,可能通过激活NRF2信号介导。这些发现表明，4-OI可以作为未来研究中治疗和预防BU的潜在治疗药物。
