Objective The purpose of this study was to establish a rapid and efficient liquid chromatography tandem mass spectrometry（LC-MS/MS） for simultaneous determination of 15 bile acids in mouse liver tissues. Methods The activated charcoal was utilized to prepare bile acid-free liver, which served as the biological matrix for the preparation of standard and quality control samples. The mouse liver tissue was homogenized, and a basic acetonitrile solution, including 5% NH 4 OH was added to precipitate proteins. The proteins were separated on an Agilent Poroshell 120 EC C18 column（100 mm×4.6 mm, 2.7 μm） by using ~2H 4 -DCA, GUDCA-d 5 , and LCA-d 4 as internal standards. The mobile phase is ammonium acetate aqueous solution and methanol acetonitrile mixed solution for gradient elution, the column temperature was 30℃, the flow rate was 0.3mL/min, and the injection volume was 2 μL. The electrospray ion source（ESI） was operated in negative ion mode, and in multiple reaction monitoring（MRM）. Results The linearity of the 15 bile acids was good with R 2 greater than 0.993, the limits of determination were less than 2 ng/mL, and the matrix effects were 90.76%-109.25%; the intra-day and inter-day accuracy and precision were less than 15%, and the stability was good under 4℃ for 24 h, repeated freeze-thaw, and freeze-storage for one month, meeting the analytical requirements of biological samples; the detection of mouse liver tissues showed that both unconjugated BAs and conjugated BAs（G-BAs, T-BAs） were dominated by maternal CA, with the highest content of TCA; the concentration of unconjugated BAs was（723.89±50.65） ng/mL, significantly higher than that of G-BAs [（56.90±11.28） ng/mL, P＜0.001]; the concentration of T-BAs was（40322.90±14034.80）ng/mL, significantly higher than unconjugated BAs（P＜0.001）, and also significantly higher than G-BAs（P＜0.001）. Conclusion The LC-MS/MS method we established is sensitive, accurate, reliable, and suitable for the determination of bile acids concentrations in mouse liver tissues, which might help for further studies.

目的 研究错配修复基因(MMR)在乙型肝炎病毒(HBV)相关肝细胞癌中表达的影响因素.方法 回顾性分析2019年12月至2021年6月首都医科大学附属北京佑安医院收治的125例HBV相关肝细胞癌术后MMR免疫组织化学结果,将其分为MMR缺失(dMMR)组(18例)和MMR正常(pMMR)组(107例),比较两组病理特征和临床指标,进一步分析HBV相关肝细胞癌患者发生dMMR的影响因素.结果 dMMR组缺失情况包括MutL蛋白同系物1(MLH1)/减数分裂后分离蛋白2(PMS2)表达缺失(4例)、MLH1表达缺失(1例)、MutS蛋白同系物2(MSH2)/PMS2表达缺失(1例)、PMS2表达缺失(12例).dMMR组坏死率、微血管侵犯率、谷草转氨酶水平、异常凝血酶原水平低于pMMR组,差异有统计学意义(P＜0.05).两组分化程度、Edmondson分级、P53蛋白强度比较,差异有统计学意义(P＜0.05).多因素分析结果显示,Edmondson分级、谷草转氨酶水平是发生dMMR的独立影响因素(P＜0.05).结论 dMMR在HBV相关肝细胞癌中是一种低频事件,与患者Edmondson分级、谷草转氨酶水平有关,可能是治疗疾病的一种有效的靶标.

Understanding the underlying mechanism of HBV maturation and subviral particle production is critical to control HBV infection and develop new antiviral strategies. Here, we demonstrate that deoxycholic acid (DCA) plays a central role in HBV production. HBV infection increased DCA levels, whereas elimination of DCA-producing microbiome decreased HBV viral load. DCA can bind to HBs antigen via LXXLL motif at TM1 and TM2 region to regulate HBs-HBc interaction and the production of mature HBV. Plasma DCA levels from patients undergoing antiviral therapy were significantly higher in those with positive HBV viral load. These results suggest that intestinal DCA-producing microbiome can affect the efficiency of antiviral therapy and provide a potential novel strategy for HBV antiviral therapy.