青黛通过影响GPR41/43信号通路调控溃疡性结肠炎大鼠Treg/Th17免疫平衡的机制研究

目的探讨青黛通过影响GPR41/43信号通路调控溃疡性结肠炎大鼠Treg/Th17免疫平衡的机制。方法将24只健康的SPF级雄性SD大鼠随机分为空白组、模型组与青黛组。模型组和青黛组大鼠自由饮用4.5%DSS溶液以制备结肠炎模型,空白组自由饮用去离子水作为对照,同时青黛组大鼠给予青黛(600 mg/kg)灌胃,模型组、空白组大鼠给予去离子水处理,每天观察大鼠一般情况,记录体质量、粪便性状,检测粪便潜血,计算疾病活动指数,干预7 d,麻醉后处死大鼠,取血及结肠组织。RT-qPCR法检测结肠RORγt mRNA、Foxp3mRNA的表达;Western Blotting法检测结肠GPR41、GPR43、RORγt、Foxp3蛋白的含量,ELISA法检测血清IL-10、IL-17水平。结果与空白组相比,DSS诱导的结肠炎大鼠结肠GPR41、GPR43、FOXP3,血清IL-10的表达明显降低(P <0.05或P <0.01),结肠RORγt、血清IL-17表达明显升高(P <0.05或P <0.01);青黛干预后,大鼠结肠GPR41、GPR43、FOXP3、FOXP3 m RNA,血清IL-10的表达较模型组明显升高(P <0.05或P <0.01),结肠RORγt、RORγt mRNA、血清IL-17表达较模型组明显降低(P <0.05)。结论青黛能够上调GPR41、GPR43的表达,进而调节Treg/Th17免疫平衡治疗溃疡性结肠炎。

Study on the Mechanism of Indigo Naturalis Regulating the Immune Balance of Treg/Th17 by Affecting GPR41/43 Signaling Pathway in DSS-Induced Ulcerative Colitis of Rats

Objective:To explore the mechanism of Indigo Naturalis regulating the immune balance of colonic Treg/Th17 by affecting GPR41/43 signaling pathway in rats with DSS-induced colitis.Methods:A total of 24 healthy SPF male SD rats were randomly divided into the control group,model group and Indigo Naturalis group.The rats in the model group and Indigo naturalis group had free access to drink 4.5%DSS to establish the colitis model.Rats in the control group had free access to distilled water.At the same time,rats in control group,model group and Indigo Naturalis group were treated with distilled water or Indigo Naturalis(600 mg/kg)gavage,respectively.Weight,scores of stool consistency and rectal bleeding were measured daily to calculate disease activity index.After 7 days of intervention,all rats were sacrificed and sampled for blood and colonic tissue.The expression of RORγt and Foxp3 mRNA in colon tissue was detected by RT-PCR.Western Blot was used to detect the protein content of GPR41,GPR43,RORγt and FOXP3 in colon.Elisa was used to detect IL-10 and IL-17 in serum.Results:Compared with the control group,the expression of GPR41,GPR43,FOXP3 in colon and IL-10 in serum in DSS-induced colitis rats were significant decrease(P<0.05 or P<0.01);RORγt in colon and IL-17 in serum were significant increase(P<0.05 or P<0.01).Compared with the model group,the administration of Indigo Naturalis elicited significant increase in the expression of GPR41,GPR43,FOXP3 mRNA,FOXP3 protein in colon and IL-10 in serum(P<0.05);the expression of RORγt mRNA,RORγt protein in colon and IL-17 in serum obviously decreased(P<0.05).Conclusion:Indigo Naturalis protects against DSS-induced colitis through regulating the immune balance of Treg/Th17 via up-regulating the expression of GPR41 and GPR43.