Bax抑制因子1对人妊娠期肝内胆汁淤积症胎盘滋养细胞凋亡的影响及其机制  

Effect of over-expression of Bax inhibitor 1 on placental trophoblast cell apoptosis in intrahepatic cholestasis during pregnancy and its mechanism

作　　者：冯国惠[1] 美丽班·买买提祖农 黄莺[1] Feng Guohui;Meiliban·Maimaiti Zunong;Huang Ying(Department of Obstetrics,People's Hospital of Xinjiang Uygur Autonomous Region,Urumqi 830000,China)

机构地区：[1]新疆维吾尔自治区人民医院产科,乌鲁木齐830000

出　　处：《解剖学杂志》2021年第5期375-381,F0002,共8页Chinese Journal of Anatomy

基　　金：新疆维吾尔自治区自然科学基金(2018D01C101,2021D01C170)。

摘　　要：目的:探讨Bax抑制因子1(BI-1)对人妊娠期肝内胆汁淤积症(ICP)胎盘滋养细胞凋亡的影响及其机制。方法:选取2018年5月至2019年5月新疆维吾尔自治区人民医院产科住院分娩的ICP孕产妇15例为研究对象,设为ICP组,另取15例正常孕产妇作为对照组,免疫组织化学显色检测ICP组和对照组孕妇胎盘组织BI-1的表达;体外培养滋养细胞系HTR8,应用不同浓度(10、50、100μmol/L)的牛磺胆酸(TCA)进行刺激,RT-PCR及免疫印迹检测HTR8细胞BI-1 mRNA及蛋白的表达;用过表达BI-1的慢病毒载体感染HTR8细胞,荧光显微镜及RT-PCR检测感染效率后,将细胞分为对照组(NC组)、TCA处理的感染LV-NC细胞组(TCA+LV-NC组)、TCA处理感染LV-BI-1细胞组(TCA+LV-BI-1组);分别用Annexin V-FITC、透射电镜及JC-1流式线粒体膜电位检测试剂盒检测3组滋养细胞凋亡、线粒体超微结构及线粒体膜电位;免疫印迹检测3组细胞Cyt-C及凋亡相关蛋白Bcl-2、Bax及cleaved caspase-3的表达。结果:与对照组相比,ICP组胎盘组织BI-1表达显著降低;体外实验结果显示,TCA能够显著降低HTR8细胞BI-1 mRNA及蛋白表达,且呈浓度依赖性;应用慢病毒成功建立过表达BI-1的滋养细胞系。与NC组细胞相比,TCA+LV-NC组与TCA+LV-BI-1组细胞凋亡率和线粒体损伤水平均显著增加,线粒体膜电位明显降低;而与TCA+LV-NC组相比,LV+BI-1组细胞凋亡率与线粒体损伤水平均明显降低,线粒体膜电位显著增加;过表达BI-1能够有效阻止TCA导致的滋养细胞Bcl-2/Bax比值的降低,以及线粒体Cyt-C的释放及cleaved caspase-3表达的增加。结论:BI-1在ICP患者胎盘组织中的表达显著降低,而体外过表达BI-1可能通过上调滋养细胞中Bcl-2/Bax比值,抑制细胞线粒体膜电位降低及结构损伤,从而减少Cyt-C的释放,最终降低凋亡蛋白caspase-3活化而改善TCA诱导的凋亡作用。Objective:To explore the effect and mechanism of Bax inhibitor 1(BI-1)on apoptosis of human placental trophoblast in intrahepatic cholestasis of pregnancy(ICP).Methods:Fifteen patients with ICP who hospitalized in Department of Obstetrics,People’s Hospital of Xinjiang Uygur Autonomous Region from May 2018 to May 2019 were enrolled in this study and designed as ICP group.Meanwhile,fifteen healthy pregnant women were enrolled as control group.The expression of BI-1 in placenta of ICP pregnant women and normal control group was detected by immunohistochemistry.The trophoblast line HTR8 was cultured in vitro and stimulated by taurocholate(TCA)of different concentrations(0,50,100μmol/L).The mRNA and protein expression level of BI-1 in HTR8 were detected by RT-PCR and Western blotting.HTR8 cells were infected with lentivirus to overexpress BI-1,and the infection efficiency was detected by fluorescence microscopy and RT-PCR.The cells were divided into three groups:negative control group(NC),TCA treated LV-NC group(TCA+LV-NC),and TCA treated LV-BI-1 group(TCA+LV-BI-1).Annexin V-FITC,transmission electron microscopy and JC-1 flow cytometry were used to detect trophoblast apoptosis,mitochondrial ultrastructure and mitochondrial membrane potential.Western blotting was used to detect the expression of Cyt-C and apoptosis related proteins Bcl-2,Bax and cleaved caspase-3 in TCA induced trophoblasts.Results:Compared with the NC group,the expression of BI-1 in the placenta of ICP patients was significantly decreased.In vitro experiments showed that TCA could significantly reduce the expression of BI-1 mRNA and protein in trophoblasts in a concentration dependent manner.A trophoblast cell line overexpressing BI-1 was successfully established by lentivirus.Compared with NC group,TCA+LV-NC group and TCA+LV-BI-1 group significantly increased the apoptosis rate and mitochondrial damage level,and significantly decreased the mitochondrial membrane potential.Compared with TCA+LV-NC group,the apoptosis rate and mitochondrial damage le

关 键 词：妊娠期肝内胆汁淤积症 滋养细胞 Bax抑制因子1 凋亡 线粒体 

分 类 号：R714.255[医药卫生—妇产科学]