复方嗜酸乳杆菌对腹泻型肠易激综合征模型大鼠肠黏膜屏障功能的保护作用

Protective effect of compound lactobacillus acidophilus on intestinal mucosal barrier function in rats with diarrhea-predominant irritable bowel syndrome

目的研究复方嗜酸乳杆菌对腹泻型肠易激综合征(IBS-D)模型大鼠肠黏膜屏障功能的保护作用,及其与过氧化物酶体增殖物激活受体γ/核因子-κB(PPARγ/NF-κB)通路的关系。方法SPF级SD大鼠用束缚应激联合20 mL·kg^(-1)番泻叶建立IBS-D模型,并随机分为模型组、对照组和实验组,每组10只;另取10只正常大鼠作为空白组。空白组和模型组均灌胃给予等量0.9%NaCl;对照组灌胃给予20 mL·kg^(-1)曲格列酮;实验组灌胃给予20 mL·kg^(-1)复方嗜酸乳杆菌片。4组大鼠每天给药1次,连续14 d。末次给药24 h后,用免疫印迹检测肠黏膜组织中紧密连接蛋白1(ZO-1)、封闭蛋白1(Claudin 1)、PPARγ和NF-κB p65蛋白的表达水平。结果实验组、对照组、模型组和空白组的肠黏膜组织ZO-1蛋白水平分别为0.72±0.09,0.71±0.10,0.22±0.05和0.97±0.12,Claudin 1蛋白水平分别为0.65±0.08,0.68±0.07,0.34±0.06和0.96±0.11,PPARγ蛋白水平分别为1.84±0.15,1.73±0.14,1.11±0.12和2.54±0.23,胞核NF-κB p65蛋白水平分别为0.62±0.08,0.61±0.07,1.32±0.14和0.02±0.01,胞浆NF-κB p65蛋白水平分别为1.13±0.09,1.14±0.09,0.55±0.08和1.31±0.12,实验组和对照组的上述指标与模型组比较,差异均有统计学意义(均P<0.05)。结论复方嗜酸乳杆菌可通过上调ZO-1和Claudin 1蛋白表达,有效保护IBS-D大鼠肠黏膜屏障,降低肠黏膜通透性,其机制可能与调节PPARγ/NF-κB通路,抑制炎症反应有关。

Objective To study the protective effect of compound lactobacillus acidophilus on intestinal mucosal barrier function in rats with diarrhea-predominant irritable bowel syndrome(IBS-D)and its relationship with peroxisome proliferator-activated receptorγ/nuclear factor-κB(PPARγ/NF-κB)pathway.Methods SPF SD rats were treated by binding joint stress and senna 20 mL·kg-1 to set up IBS-D model.According to random number table method,the rats were divided into model group,experimental group and control group,10 cases in each group,another set of 10 normal rats as blank group.Experimental group was given the compound lactobacillus acidophilus 20 mL·kg^(-1).Control group received troglitazone 20 mL·kg^(-1)lavage.Blank group and model group were given the equal 0.9%saline lavage.Four groups were givencontinuous intervention for 14 days with once a day.Western blot was used to detect the expression levels of zonula occludin 1(ZO-1),Claudin 1,peroxisome proliferator-activated receptorγ(PPARγ)and nuclear factor-kappa B p65(NF-κB p65)proteins in the intestinal mucosa.Results The ZO-1 proteins of the intestinal mucosal tissues in experimental,control,model and blank groups were 0.72±0.09,0.71±0.10,0.22±0.05 and 0.97±0.12,the Claudin 1 proteins were 0.65±0.08,0.68±0.07,0.34±0.06 and 0.96±0.11,the PPAR proteins were1.84±0.15,1.73±0.14,1.11±0.12 and 2.54±0.23,the nuclei NF-κB p65 proteins were 0.62±0.08,0.61±0.07,1.32±0.14 and 0.02±0.01,the cytoplasm NF-κB p65 proteins were 1.13±0.09,1.14±0.09,0.55±0.08 and 1.31±0.12,respectively.There were significant differences in the above-mentioned indexes between experimental group,control group and model group(all P<0.05).Conclusion Compound lactobacillus acidophilus can effectively protect IBS-D rats’intestinal barrier and reduce intestinal mucosal permeability by up-regulating the expressions of ZO-1 and Claudin 1 proteins.The mechanism may be related to the regulation of PPARγ/NF-κB pathway and the inhibition of inflammatory response.