鼠李糖乳杆菌对感染人轮状病毒乳鼠空肠黏膜上皮细胞的保护作用

Protective Effect of Lactobacillus Rhamnosus GG on Jejunum Mucosal Epithelial Cells of Human Rotavirus-infected Neonatal Mice

目的观察鼠李糖乳杆菌(Lactobacillus rhamnosus GG,LGG)对感染人轮状病毒(human rotavirus,HRV)乳鼠空肠黏膜上皮细胞的保护作用。方法将60只昆明种乳鼠均分为4组:灌服HRV作为感染组;灌服HRV前和后灌服LGG作为预处理组和治疗组;正常对照组灌服细胞培养液。从第4天开始,连续5d观察各组乳鼠的临床症状,每天2次检测乳鼠大便HRV抗原。在实验的第9天随机处死每组中的8只乳鼠,取出空肠段苏木精-伊红染色,利用Image-Pro Plus 5.1图像软件分析各组乳鼠空肠黏膜厚度、绒毛高度和隐窝深度。利用光学显微镜和透射电子显微镜观察乳鼠空肠黏膜上皮细胞的病理变化。结果至第9天,对照组乳鼠无腹泻、无死亡。HRV感染组、预处理组、治疗组乳鼠腹泻率和死亡率分别为100.00%、46.67%,13.33%、0%,26.66%、6.67%。对照组、HRV感染组、预处理组、治疗组乳鼠空肠黏膜隐窝深度分别为(35.2±2.4)、(45.9±3.6)、(35.8±5.6)和(38.9±2.9)μm,HRV感染组明显高于其它3组(均P<0.01)。病理检测发现HRV感染组乳鼠空肠黏膜上皮细胞出现广泛的空泡样变性,而预处理组和治疗组乳鼠空肠黏膜上皮细胞空泡样变性的情况均有减少。预处理组与治疗组相比,前者对乳鼠空肠黏膜上皮细胞的保护效果更好。结论 LGG对感染HRV的乳鼠空肠黏膜上皮细胞有一定的保护作用,感染前灌服LGG的保护效果好于感染后灌服。

Objective To investigate the possible protective effect of Lactobacillus rhamnosus GG（LGG）on jejunum mucosal epithelial cells of human rotavirus（HRV）-infected neonatal mice.Methods Sixty 4-day-old Kunming mice were randomly divided into control group,HRV infected group,LGG pretreated group（treated before HRV infection）and LGG treated group（treated after HRV infection）.From 4th to 9th day,the clinical manifestation of neonatal mice was observed,and stool HRV antigen was examined.On the 9th day,8 mice in every group were killed,and the jejunum was taken out from the mice.The thickness of jejunum mucosa,height of villi and depth of crypt were assessed by Image-Pro Plus 5.1 software after HE staining,and the pathological changes of jejunum mucosal epithelial cells were observed under the light microscopy and transmission electron microscopy.Results The mice in normal control group didn＇t suffer from diarrhea and there was no death on the 9th day.The diarrhea and mortality rate of HRV infected group,LGG pretreated group and LGG treated group was 100.00%,46.67%;13.33%,0% and 26.66%,6.67% respectively.The crypt depth of control group,HRV infected group,LGG pretreated group and LGG treated group was（35.2±2.4）,（45.9±3.6）,（35.8±5.6） and（38.9±2.9） μm respectively.The crypt depth in HRV infected group was obviously greater than other groups（P0.01）.Pathologically,jejunum mucosal epithelial cells in HRV infected group showed extensive vacuolate degeneration,and the vacuolate degeneration of LGG pretreated and treated groups turned obviously milder than HRV infected group.The protective effect of LGG on jejunum mucosal epithelial cells in LGG pretreated group was better than LGG treated group.Conclusion The LGG possessed protective effect on jejunum mucosal epithelial cells of HRV-infected neonatal mice,and the protective effect of LGG pretreated group was better than LGG treated group.