Development of probiotics with antioxidant action for treatment of inflammatory bowel disease

1. 我们研究了硫氧还蛋白在炎症性肠病（IBD）患者中的意义，发现IBD患者血清硫氧还蛋白和巨噬细胞迁移抑制因子（MIF）水平显著高于正常对照组1。血清硫氧还蛋白水平与疾病活动度相关。硫氧还蛋白改善葡聚糖硫酸钠（DSS）诱导的白介素10敲除小鼠结肠炎和结肠炎症。硫氧还蛋白显著抑制小鼠结肠组织中肿瘤坏死因子-α和干扰素-γ的升高。抗硫氧还蛋白治疗加重了dss诱导的结肠炎，MIF升高。重组硫氧还蛋白在体外细胞培养中抑制人单核细胞MIF的产生。因此，我们推测硫氧还蛋白不仅通过其抗氧化和抗炎作用，还通过下调MIF的产生来改善结肠炎症。由于硫氧还蛋白对实验性结肠炎的治疗是有效的，我们的目标是开发分泌硫氧还蛋白的益生菌，因为具有抗氧化作用的益生菌由于具有清除活性氧和调节肠道菌群的双重作用，预计比抗氧化药物或单独的益生菌更有益。我们构建了硫氧还蛋白表达质粒，并将其转染到乳酸杆菌中，乳酸杆菌将硫氧还蛋白分泌到培养基中。然而，分泌硫氧还蛋白的乳杆菌并没有显著改善实验性结肠炎，这可能是由于肠道中硫氧还蛋白的产生较低。我们现在正在开发另一种有效产生硫氧还蛋白的益生菌。

1. We investigated the significance of thioredoxin in patients with inflammatory bowel disease (IBD) and found that serum thioredoxin and macrophage migration inhibitory factor (MIF) levels were significantly higher in patients1 with the IBD than normal controls. Serum thioredoxin levels correlated with disease activity.2. Thioredoxin ameliorated dextran sulfate sodium (DSS)-induced colitis and colonic inflammation of interleukin 10 knockout mice. Increase of tumor necrosis factor-α and interferon-γ in colonic tissues was significantly suppressed in thioredoxin-treated mice. Anti-thioredoxin treatment exacerbated DSS-induced colitis with increase of MIF. Recombinant thioredoxin suppressed MIF production in human monocyte cells in in vitro cell culture. Therefore, we speculated that thioredoxin ameliorates colonic inflammation not only by its antioxidative and anti-inflammatory effects but also down-regulating MIF production.3. As thioredoxin administration was effective for the treatment of experimental colitis, we aimed to develop probiotics that secrete thioredoxin because probiotics with antioxidant action is expected to be more beneficial than antioxidant drugs or probiotics alone due to the dual action of scavengery of reactive oxygen species and modulation of intestinal flora. We constructed a thioredoxin expression plasmid and transfected it into Lactobacillus Lactis, which secreted thioredoxin into the culture media. However, administration of thioredoxin-secreting Lactobacillus did not significantly improve experimental colitis, possibly due to low thioredoxin production in the intestine. We are now developing another probiotics which efficiently produces thioredoxin.