Objective:To investigate the effects of gut microbiota in patients with hepatitis B cirrhosis on function of intestinal mucosal barrier and progression of cirrhosis in mice.Methods:Fecal samples of 12 patients and 12 healthy individuals in the Second Affiliated Hospital of Xi′an Jiaotong University from September 2017 to June 2018 were collected. Gut microbiota structure was analyzed through 16S rDNA sequencing and bacterial suspension was prepared. Male C57BL/6 mice were randomly (random number) divided into four groups: healthy control group (HC group), cirrhosis model group (LC group), model group+ bacterial suspension of healthy individuals (FMT-HC group), model group+ bacterial suspension of patients (FMT-LC group). Cirrhosis model was established and mice were gavaged with bacterial suspension, lasting for 12 weeks. Colon pathological morphology was observed by hematoxylin-eosin staining, injury of intestinal mucosal barrier was detected using enzyme-linked immunosorbent assay and fluorescent probe, the expression of intestinal mucosal barrier and hepatic fibrosis related factors were detected by real-time quantitative polymerase chain reaction and immunofluorescence.Results:The expression levels of mucin-2 and claudins-2 in the colon of mice in FMT-LC group were significantly lower than those in FMT-HC group (0.36±0.21 vs. 1.00±0.36, t=4.659, P<0.01 and 0.61±0.42 vs. 1.00±0.17, t=2.596, P<0.05), and the concentrations of FITC-dextran and lipopolysaccharide in the peripheral blood were significantly higher than those in FMT-HC group [(9.32±2.24) μg/ml vs. (5.23±1.34) μg/ml, F=15.118, P<0.01 and (88.55±10.50) ng/ml vs. (76.48±10.13) ng/ml, F=5.473, P<0.05]. The expression levels of transforming growth factor-β1 (3.39±2.67 vs. 0.95±0.12, t=2.744, P<0.05) and other pro-fibrotic factors, as well as α-smooth muscle actin in the liver of mice in FMT-LC group were significantly higher than those in FMT-HC group, and the liver injury was aggravated. Conclusion:The gut microbiota of patients with hepatitis B cirrhosis can reduce the intestinal mucosal barrier function and promote cirrhosis development in mice.

目的 探讨miR-20a-5p在人肝癌细胞系中表达及其对肝癌细胞Bel-7402增殖及凋亡的影响.方法 通过反转录实时定量聚合酶链反应(RT-qPCR)考察miR-20a在肝细胞L-02和7种肝癌细胞中的表达;构建过表达或沉默miR-20a-5p的人肝癌Bel-7402细胞株;通过噻唑蓝(MTT)实验考察过表达或沉默miR-20a-5p后对细胞增殖的影响;通过AnnexinV-FITC/PI流式实验考察对细胞凋亡的影响,并进一步通过蛋白质免疫印迹试验考察对凋亡相关基因蛋白表达水平的影响.结果 与人肝细胞L-02相比,6种细胞系的miR-20a-5p表达水平较低.过表达miR-20a-5p后细胞增殖能力显著下降(P=0.011),沉默后显著上升(P=0.007).高表达miR-20a-5p后细胞凋亡和早期凋亡比例均显著增加(P=0.009、0.017),沉默miR-20a-5p均明显降低(P=0.012、0.007).高表达miR-20a-5p后细胞中凋亡抑制蛋白XIAP、Survivin、Bcl-2表达下调,凋亡促进蛋白Bax表达上调;沉默miR-20a-5p后XIAP、Survivin、Bcl-2表达上调,Bax表达下调.结论 miR-20a-5p在6种肝癌细胞中低表达,可促进肝癌细胞Bel-7402凋亡,抑制细胞增殖能力.