基于肠道特异性丙酮酸激酶M2基因敲除小鼠研究布拉氏酵母菌治疗溃疡性结肠炎的作用及机制

Study on the effects and mechanism of S.boulardii on ulcerative colitis based on intestinal specific PKM2 knockout mice

目的基于肠道特异性丙酮酸激酶M2(PKM2)基因敲除小鼠研究布拉氏酵母菌治疗溃疡性结肠炎(ulcerative colitis,UC)的作用及机制.方法选择野生型C57BL/6J小鼠并随机分为PKM2-WT组、PKM2-WT+UC组、PKM2-WT+UC+布拉氏酵母菌组,选择肠道特异性PKM2基因敲除小鼠并随机分为PKM2-KO组、PKM2-KO+UC组、PKM2-KO+UC+布拉氏酵母菌组,采用葡聚糖硫酸钠(dextran so-dium sulfate,DSS)诱导UC模型,给予布拉氏酵母菌灌胃干预.比较各组间疾病活动指数(disease activi-ty index,DAI)、肠黏膜组织病理评分、血清中二胺氧化酶及D-乳酸含量、肠黏膜中炎症因子及紧密连接蛋白表达量的差异.结果PKM2-WT+UC组的DAI指数、肠黏膜组织病理评分、血清中二胺氧化酶及D-乳酸含量、肠黏膜中TNF-α及IL-1β含量均高于PKM2-WT组,肠黏膜中PKM2、ZO-1、Occludin、Claudin-1的表达量低于PKM2-WT组;PKM2-WT+UC+布拉氏酵母菌组的DAI指数、肠黏膜组织病理评分、血清中二胺氧化酶及D-乳酸含量、肠黏膜中TNF-α及IL-1β含量均低于PKM2-WT+UC组,肠黏膜中PKM2、ZO-1、Occludin、Claudin-1的表达量高于PKM2-WT+UC组;PKM2-KO+UC+布拉氏酵母菌组肠黏膜中PKM2不表达,DAI指数、肠黏膜组织病理评分、血清中二胺氧化酶及D-乳酸含量、肠黏膜中TNF-α及IL-1β含量均高于PKM2-WT+UC+布拉氏酵母菌组,肠黏膜中ZO-1、Occludin、Claudin-1的表达量PKM2-WT+UC+布拉氏酵母菌组.结论布拉氏酵母菌治疗DSS诱导UC小鼠能够改善肠黏膜病理改变、减轻炎症反应及黏膜屏障损伤,且这一作用与增加PKM2的表达有关.

Objective To study the effects and mechanism of S.boulardii on ulcerative colitis(UC)based on intestinal specific PKM2 knockout mice.Methods The wild C57BL/6J mice were randomly divided into PKM2⁃WT,PKM2⁃WT+UC,PKM2⁃WT+UC+S.boulardii groups.The intestinal specific PKM2 knockout mice were randomly divided into PKM2⁃KO,PKM2⁃KO+UC and PKM2⁃KO+UC+S.boulardii groups.The UC model was in⁃duced by dextran sodium sulfate(DSS)and the S.boulardii was given intragastric intervention.The differences of dis⁃ease activity index(DAI),histopathological score of intestinal mucosa,the contents of diamine oxidase and D⁃lac⁃tate in serum,the contents of inflammatory factors and the expression of tight junction protein in intestinal mucosa were compared.Results In PKM2⁃WT+UC group,the DAI index,the histopathological score of intestinal muco⁃sa,the contents of diamine oxidase and D⁃lactate in serum,the contents of TNF⁃αand IL⁃1βin intestinal mucosa were higher than those in PKM2⁃WT group,and the expressions of PKM2,ZO⁃1,occludin and Claudin⁃1 in intesti⁃nal mucosa were lower than those in PKM2⁃WT group;in PKM2⁃WT+UC+s.boulardii group,the DAI index,the histopathological score of intestinal mucosa,the contents of diamine oxidase and D⁃lactate in serum,the contents of TNF⁃αand IL⁃1βin intestinal mucosa were lower than those in PKM2⁃WT+UC group,and the expressions of PKM2,ZO⁃1,occludin and Claudin⁃1 in intestinal mucosa were higher than those in PKM2⁃WT+UC group;PKM2⁃KO+UC+s.boulardii group,PKM2 was not expressed,the DAI index,the histopathological score of intestinal mu⁃cosa,the contents of diamine oxidase and D⁃lactate in serum,the contents of TNF⁃αand IL⁃1βin intestinal mucosa were higher than those in PKM2⁃WT+UC+s.boulardii group,and the expressions of PKM2,ZO⁃1,occluding and Claudin⁃1 in intestinal mucosa were lower than those in PKM2⁃WT+UC+s.boulardii group.Conclusion S.boular⁃dii can improve the pathological changes of intestinal mucosa,reduce the inflammatory response and mucosal barrier damage in DSS induced UC mice,and this effect is related to the increase of PKM2 expression.