驴食草酚调控ERK1/2和p38 MAPK信号通路防治溃疡性结肠炎的研究

Vestitol prevents and treats for ulcerative colitis through regulating ERK1/2 and p38 MAPK signaling pathway

目的基于ERK1/2和p38 MAPK信号通路探讨驴食草酚对溃疡性结肠炎小鼠的干预作用。方法将32只雄性C57BL/6小鼠随机分为正常组、模型组、驴食草酚组和柳氮磺吡啶组,每组8只。模型组、驴食草酚组和柳氮磺吡啶组小鼠均采用饮水中添加3%葡聚糖硫酸钠溶液方法构建溃疡性结肠炎模型,连续7 d。从实验第1天起,驴食草酚组给予驴食草酚10 mg/kg灌胃,柳氮磺吡啶组给予柳氮磺吡啶0.5 g/kg灌胃,正常组和模型组灌喂等量生理盐水,均连续7 d。干预期间观察各组小鼠体重、粪便性状及便血情况,计算疾病活动指数(DAI)。末次灌胃后处死小鼠,测量结肠长度,HE染色观察结肠组织病理形态,酶联免疫吸附法检测血清白细胞介素(IL)-17A含量,流式细胞术检测结肠组织中中性粒细胞比例,Western blot法检测结肠组织中ERK1/2、p-ERK1/2、p38 MAPK、p-p38 MAPK蛋白表达情况。结果模型组小鼠体重明显低于正常组(P<0.05),DAI明显高于正常组(P<0.05),结肠长度明显短于正常组(P<0.05),驴食草酚组和柳氮磺吡啶组各指标均较模型组明显改善(P均<0.05)。模型组小鼠结肠黏膜上皮组织破损严重,黏膜下层有大量的炎性细胞浸润,驴食草酚组和柳氮磺吡啶组结肠组织损伤程度明显减轻。模型组小鼠血清IL-17A含量、结肠组织中中性粒细胞比例、结肠组织中p-ERK1/2/ERK1/2和p-p38 MAPK/p38 MAPK比值均明显高于正常组(P均<0.05),驴食草酚组和柳氮磺吡啶组各指标均明显低于模型组(P均<0.05)。结论驴食草酚可能通过下调ERK1/2和p38 MAPK的磷酸化表达,抑制IL-17A分泌,降低结肠组织中性粒细胞比例,减轻溃疡性结肠炎炎性损伤。

Objective It is to explore the intervention of vestitol on ulcerative colitis(UC)in mice based on ERK1/2 and p38 MAPK signaling pathways.Methods Thirty-two male C57BL/6 mice were randomly divided into normal group,model group,vestitol group and sulfasalazine group,8 mice in each group.The mice in the model group,vestitol group and sulfasalazine group were given 3%Dextran sodium sulfate(DSS)solution in the drinking water to establish models of UC,continuously treated for 7 days.From the first day of the experiment,the vestitol group was given vestitol 10 mg/kg by gavage,the sulfasalazine group was given sulfasalazine 0.5 g/kg by gavage,and the normal group and model group were given the same amount of normal saline,all treated for 7 days.During the treatment,the changes of body weight,fecal traits and hematochezia of the mice in each group were observed,and the disease active index(DAI)was calculated.After the last administration,the mice were killed,the length of their colon was measured,the pathological morphology of colon tissue was observed by HE staining,the content of serum interleukin-17A(IL-17A)was detected by enzyme-linked immunosorbent assay,the proportion of neutrophils in colon tissue was detected by flow cytometry,and the protein expression of ERK1/2,p-ERK1/2,p38 MAPK,and p-p38 MAPK in colon tissue was detected by Western blot.Results The weight of mice in the model group was significantly lower than that in the normal group(P<0.05),the DAI was significantly higher than that in the normal group(P<0.05),the length of colon was significantly shorter than that in the normal group(P<0.05),and the indexes in the vestitol group and sulfasalazine group were significantly improved compared with those in the model group(all P<0.05).In the model group,the epithelial tissue of colon mucosa was seriously damaged,and there were a large number of inflammatory cells infiltrating in the submucosa.The degree of colon tissue damage in the vestitol group and sulfasalazine group was significantly improved.In the model group,the content of IL-17A in serum,the proportion of neutrophils in colon tissue,and the ratios of p-ERK1/2/ERK1/2 and p-p38 MAPK/p38 MAPK in colon tissue were significantly higher than those in the normal group(all P<0.05),while the indexes in the vestitol group and sulfasalazine group were significantly lower than those in the model group(all P<0.05).Conclusion Vestitol can down-regulate the phosphorylation expression of ERK1/2 and P38 MAPK to inhibit the secretion of IL-17A,reduce the proportion of neutrophils in colon tissue,thus to relive inflammatory damage of UC.