MagaininⅡ对EHEC O157:H7所致小鼠肠道屏障损伤及炎症状态的影响  

Effect of MagaininⅡon Intestinal Barrier Injury and Inflammatory State Induced by EHEC O157:H7 in Mice(Mus musculus)

作　　者：农可懿 房鑫 刘又铭 张海文[1] NONG Ke-Yi;FANG Xin;LIU You-Ming;ZHANG Hai-Wen(College of Animal Science and Technology,Hainan University,Haikou 570228,China)

机构地区：[1]海南大学动物科技学院,海口570228

出　　处：《农业生物技术学报》2023年第4期812-823,共12页Journal of Agricultural Biotechnology

基　　金：海南省自然科学基金(320RC463);海南省高等学校教育教学改革研究资助项目(Hnjg2020-23);海南大学教育教学改革研究项目(hdjy2026)。

摘　　要：O157:H7是一种肠出血性大肠杆菌(enterohaemorrhagic Escherichia coli,EHEC)菌株,作为食源性病原体可导致畜禽与人类(Homo sapiens)患病。马盖宁(magainins)是具有抗菌和抗肿瘤特性的阳离子肽,对革兰氏阴性和阳性菌具有抗菌活性。本研究旨在明确蛙(Xenopus laevis)源抗菌肽MagaininⅡ对EHEC O157:H7攻毒小鼠(Mus musculus)的肠道炎症及微生物区系的影响。以体重接近的C57/BL6雄性小鼠40只为受试对象,随机分为4组(每组10只):CK组,O157组,MagⅡ组,O157+MagⅡ组。在相同基础日粮条件下,分别在1、5和9 d对O157组和O157+MagⅡ组以0.1 mL O157菌液(浓度为106CFU/mL)灌胃,CK组和MagⅡ组灌胃相同体积的PBS溶液;1 h后,MagⅡ组和O157+MagⅡ组按照5 mg/kg体重,于腹腔注射0.25 mL MagaininⅡ溶液,CK组和O157组注射相应体积的无菌生理盐水;10 d后安乐处死全部受试小鼠,采集相应组织样本进行检测。结果表明,MagaininⅡ单独处理对小鼠血清炎性细胞因子浓度和空肠炎性细胞因子、屏障功能相关基因表达均无影响;EHEC O157:H7处理导致小鼠空肠白细胞介素-6(interleukin-6,IL-6)、IL-1β、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)基因表达水平及血清IL-1β、IL-6、TNF-α浓度显著升高(P<0.05),血清IL-10水平显著降低(P<0.05),空肠紧密连接蛋白claudin-1、黏蛋白-1(mucin-1,MUC-1)、MUC-2的表达水平显著降低(P<0.05);MagaininⅡ处理可显著改善EHEC O157:H7导致的IL-1β、IL-6、TNF-α、claudin-1、MUC-1、MUC-2基因表达及血清IL-1β、IL-6、IL-10浓度的异常(P<0.05)。另外,本研究通过16S rDNA测序来分析MagaininⅡ干预引起的肠道微生物变化。测序结果显示,在属水平上,O157组中普氏菌属(Prevotella)和拟杆菌属(Bacteroides)相对丰度显著升高(P<0.05),O157+MagⅡ组拟杆菌属相对丰度降低(P<0.05),即EHEC O157:H7攻毒后与炎症发展相关的普氏菌属和拟杆菌属丰度显著增加,MagaininⅡ处理使不利菌属拟杆菌O157:H7,an enterohemorrhagic Escherichia coli(EHEC)strain,is a foodborne pathogen that can cause disease in livestock,poultry and humans(Homo sapiens).Magainins is a cationic peptide with antibacterial and antitumor properties,and its antibacterial activity against Gram-negative and Gram-positive bacteria has been reported in previous studies.The purpose of this study was to explore the effect of frog(Xenopus laevis)derived MagaininⅡon intestinal inflammation and microflora in mice(Mus musculus)induced by EHEC O157:H7.Forty C57/BL6 male mice with similar weigh were randomly divided into 4groups with 10 replicates in each group,CK group,O157 group,MagⅡgroup,O157+MagⅡgroup,respectively.All the groups received the same basal diet.The O157 group and O157+MagⅡgroup were orally administered 0.1 mL O157 bacterial solution with a concentration of 106 CFU/mL on 1,5 and 9 d;CK group and MagⅡgroup were orally administered 0.1 mL PBS in the same time.After 1 h,MagⅡand O157+MagⅡgroup were intraperitoneally injected with 0.25 mL MagaininⅡsolution according to 5 mg/kg body weight,while CK and O157 group were intraperitoneally injected 0.25 mL sterilized saline.On the 10 d,mice were treatmented by euthanasia,and corresponding tissue samples were collected for testing.The results showed that MagaininⅡtreatment alone had no effect on the serum inflammatory cytokine concentration and the expression of jejunal inflammatory cytokines and barrier function related genes.EHEC O157:H7 treatment resulted in significant increase in the jejunum gene expression levels of interleukin-6(IL-6),IL-1β,and tumor necrosis factor-α(TNF-α)and serum concentration of IL-1β,IL-6,TNF-αin mice(P<0.05).The serum IL-10levels significantly decreased(P<0.05),as well as relative gene expression of jejunal tight junction proteins claudin-1,mucin-1(MUC-1),and MUC-2(P<0.05);MagaininⅡtreatment significantly improved EHEC O157:H7-induced relative gene expression of IL-1β,IL-6,TNF-α,claudin-1,MUC-1,MUC-2 in mouse jejunum and abnormal serum

关 键 词：抗菌肽 马盖宁Ⅱ 肠出血性大肠杆菌(EHEC) 肠道炎症 肠道菌群 

分 类 号：S859.79[农业科学—临床兽医学]