三丁酸甘油酯通过抑制铁死亡缓解2,4,6-三硝基苯磺酸诱导的大鼠肠道炎症

Tributyrin alleviating 2,4,6-trinitrobenzene sulfonic acid-induced intestinal inflammation in rats by inhibiting ferroptosis

目的:探讨三丁酸甘油酯(TB)缓解2,4,6-三硝基苯磺酸(TNBS)诱导的实验性结肠炎大鼠肠道炎症的机制。方法:选择雄性Sprague Dawley大鼠24只,随机分为4组(每组6只):对照组、模型组(TNBS组)、TB低剂量(TNBS+TB 600 mg/kg)组和TB高剂量(TNBS+TB 1000 mg/kg)组,低剂量和高剂量用药组在建模前和后1周内灌胃相应剂量的TB。造模后观察大鼠的活动情况和粪便性状,对大鼠进行疾病活动指数(DAI)评估,处死大鼠后观察结肠组织并进行苏木精-伊红染色及组织学损伤评分。采用酶联免疫吸附法(ELISA)、蛋白质免疫印迹法(western blotting)、免疫组化和生化检测方法来评估炎症表现以及与铁死亡相关信号通路的结果。结果:与对照组相比,TNBS组DAI评分、组织学损伤评分显著增高,GPX4和SLC7A11蛋白表达水平显著降低,ACSL4和FTH1表达水平增高;与TNBS相比,低剂量和高剂量TB治疗可明显减少DAI评分和组织学损伤评分,且TB高剂量组的治疗效果最佳(均P<0.05)。TB逆转了TNBS组肠上皮细胞中谷胱甘肽和丙二醛的表达,上调了GPX4和SLC7A11蛋白表达水平,同时下调了ACSL4和FTH1表达水平(均P<0.05)。结论:TB可改善TNBS诱导克罗恩病大鼠的氧化应激和肠道炎症损伤,其机制可能与抑制铁死亡通路有关。

Objective:To investigate the mechanism of tributyrin(TB)in alleviating 2,4,6-trinitrobenzene sulfonic acid(TNBS)-induced intestinal inflammation in rats with experimental colitis.Methods:A total of 24 male Sprague Dawley rats were randomly divided into four groups(6 rats in each group):control group,model group(TNBS group),low-dose TB group(TNBS+TB 600 mg/kg)and high-dose TB group(TNBS+TB 1,000 mg/kg),and the low-dose and high-dose TB groups were gavaged with the corresponding dose of TB for one week before and after modeling.After modeling,the rats were observed for activity and fecal characteristics,the rats were assessed for the disease activity index(DAI),and the colonic tissues were observed and stained with hematoxylineosin and scored for histological damage after the rats were put to death.Enzyme-linked immunosorbent assay(ELISA),western blotting,immunohistochemistry,and biochemical assays were used to assess the inflammation and the results of signaling pathways associated with ferroptosis.Results:Compared with the control group,the TNBS group had significantly higher DAI scores,histological damage scores,significantly lower protein expression levels of GPX4 and SLC7A11,and higher expression levels of ACSL4 and FTH1.Low-and high-dose TB treatment significantly reduced DAI scores and histological damage scores compared with the TNBS group,with the best treatment effect in the high-dose TB group(all P<0.05).TB reversed the expression of glutathione and malondialdehyde in intestinal epithelial cells from the TNBS group and up-regulated the GPX4 and SLC7A11 protein expression levels while down-regulating the ACSL4 and FTH1 expression levels(all P<0.05).Conclusion:TB ameliorates oxidative stress and intestinal inflammatory damage in TNBS-induced Crohn’s disease rats.Its mechanism may be related to the inhibition of the ferroptosis pathway.