Autoimmunity & Immune Regulation (AIR), Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden; Regional Cancer Center South East Sweden and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden.
Autoimmunity & Immune Regulation (AIR), Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden.
Int Immunopharmacol. 2020 Aug;85:106598. doi: 10.1016/j.intimp.2020.106598. Epub 2020 May 19.
Previous studies in a rat model of Sephadex induced lung inflammation showed that 4-Thiouridine (4SU), a thiol substituted nucleoside, was very effective in reducing edema, leukocyte influx and TNF levels in bronchoalvelolar lavage fluid. However, little is known about the factors and mechanisms underlying these effects. In the present study, we have used two separate mouse models of chronic inflammation, a model of dextran sulphate sodium (DSS) induced colitis and a model of antigen induced arthritis, to evaluate the anti-inflammatory effect of 4-thiouridine. We have analyzed a broad spectrum of inflammatory mediators in order to delineate the mechanisms behind a potential anti-inflammatory effect of 4SU. Colitis was induced in C57BL/6 mice by administration of 3.5% DSS in drinking water for 5 days and the potential anti-colitic effect of 4SU was assessed by monitoring the disease activity index (DAI), measurement of colon length and histopathological analysis of colon tissue. We analyzed tissue myeloperoxidase (MPO) activity, serum pro-inflammatory cytokines (IL-1β, IL-6 and TNF), mRNA and protein expression of pro-inflammatory cytokines, COX-2, and NF-κB activity in colitis tissue. Intracolonic administration of 4SU (5 mg/kg & 10 mg/kg.) significantly inhibited MPO activity and reduced the levels of pro-inflammatory cytokines (IL-1β, IL-6 and TNF) as well as COX-2. Further, NF-κB activation was also blocked by attenuating the phosphorylation of IkB kinase (IKK α/β) in DSS-induced colitis tissues. Arthritis was induced by intra-articular injection of mBSA in the knee of NMRI mice pre-immunized with mBSA and 4SU was administered locally by direct injection into the knee joint. The antiarthritic potential of 4SU was calculated by histopathological scores and histochemical analysis of joint tissue. Further, immunohistochemistry was used to study inflammatory cell infiltration and expression of cytokines and adhesion molecules in the synovium. Local administration of 50-100 mg/kg 4SU at the time of arthritis onset clearly prevented development of joint inflammation and efficiently inhibited synovial expression of CD18, local cytokine production and recruitment of leukocytes to the synovium. Taken together, our data clearly demonstrates a potent anti-inflammatory effect of 4SU in two experimental models. In conclusion 4SU could be a new promising candidate for therapeutic modulation of chronic inflammatory diseases like ulcerative colitis and arthritis.
先前的研究表明，在角叉菜胶诱导的大鼠肺炎症模型中，巯基取代核苷 4-硫尿苷（4SU）在减少肺泡灌洗液中的水肿、白细胞浸润和 TNF 水平方面非常有效。然而，关于这些作用的基础的因素和机制知之甚少。在本研究中，我们使用了两种慢性炎症的小鼠模型，即葡聚糖硫酸钠（DSS）诱导的结肠炎模型和抗原诱导的关节炎模型，来评估 4-硫代尿苷的抗炎作用。我们分析了广泛的炎症介质，以描绘 4SU 潜在抗炎作用的机制。通过给予饮用水中的 3.5% DSS 5 天来诱导 C57BL/6 小鼠结肠炎，并通过监测疾病活动指数（DAI）、测量结肠长度和结肠组织的组织学分析来评估 4SU 的潜在抗结肠炎作用。我们分析了组织髓过氧化物酶（MPO）活性、血清促炎细胞因子（IL-1β、IL-6 和 TNF）、促炎细胞因子、COX-2 和 NF-κB 活性的结肠组织中的 mRNA 和蛋白表达。在结肠炎组织中，4SU（5mg/kg 和 10mg/kg）的腔内给药显著抑制了 MPO 活性并降低了促炎细胞因子（IL-1β、IL-6 和 TNF）以及 COX-2 的水平。此外，NF-κB 的激活也通过减弱 DSS 诱导的结肠炎组织中 IkB 激酶（IKKα/β）的磷酸化而被阻断。关节炎通过在预先用 mBSA 免疫的 NMRI 小鼠膝关节内关节内注射 mBSA 诱导，并通过直接将 4SU 注射到膝关节内来局部给药。通过关节组织的组织病理学评分和组织化学分析计算 4SU 的抗关节炎潜力。此外，免疫组织化学用于研究滑膜中炎症细胞浸润和细胞因子及粘附分子的表达。关节炎发病时局部给予 50-100mg/kg 的 4SU 可明显预防关节炎症的发生，并有效抑制滑膜中 CD18 的表达、局部细胞因子的产生和白细胞向滑膜的募集。综上所述，我们的数据清楚地表明 4SU 在两种实验模型中具有很强的抗炎作用。总之，4SU 可能是治疗溃疡性结肠炎和关节炎等慢性炎症性疾病的一种有前途的新候选药物。
