ABCB11基因在妊娠期肝内胆汁淤积症中研究进展

ABCB11基因,也称BSEP基因,其编码的蛋白称为ABCB11蛋白,是ABC转运蛋白超家族B族成员之一。ABCB11基因的表达主要受法尼醇X受体(FXR)调控。近年研究发现,一些药物或体内的代谢产物等对ABCB11基因的调控及由基因变异等因素引起的相关蛋白功能障碍,可能在妊娠期肝内胆汁淤积症(ICP)发病中发挥重要作用,并且ABCB11基因有可能成为靶基因而作为ICP基因治疗的一种手段。     

ABCB11基因在妊娠期肝内胆汁淤积症中研究进展

ABCB11基因,也称BSEP基因,其编码的蛋白称为ABCB11蛋白,是ABC转运蛋白超家族B族成员之一.ABCB11基因的表达主要受法尼醇X受体(F3(R)调控.近年研究发现,一些药物或体内的代谢产物等对ABCB11基因的调控及由基因变异等因素引起的相关蛋白功能障碍,可能在妊娠期肝内胆汁淤积症(ICP)发病中发挥重要作用,并且ABCB11基因有可能成为靶基因而作为ICP基因治疗的一种手段.     

妊娠期肝内胆汁淤积症发病的分子机制研究进展

妊娠期肝内胆汁淤积症(ICP)发病机制尚不清楚,多数研究认为激素和遗传因素起重要作用.近年遗传性肝内胆汁淤积性疾病的研究取得重大进展,已确认若干胆淤基因如ABCB4、ABCB11及ATP8B1等.这些基因在ICP发病机制中所起的作用已引起关注.     

妊娠期肝内胆汁淤积症发病的分子机制研究进展

妊娠期肝内胆汁淤积症(ICP)发病机制尚不清楚，多数研究认为激素和遗传因素起重要作用。近年遗传性肝内胆汁淤积性疾病的研究取得重大进展，已确认若干胆淤基因如ABCB4、ABCB11及ATP881等。这些基因在ICP发病机制中所起的作用已引起关注。     

妊娠期肝内胆汁淤积症中MDR3基因表达的研究

目的:探讨MDR3基因mRNA的表达与妊娠期肝内胆汁淤积症(ICP)发病的关系.方法:从36例ICP患者和38例正常孕妇外周血标本中抽提总RNA,反转录.聚合酶链反应(RTPCR)技术扩增MDR3基因和β-Actin基因,采用凝胶分析软件对RT-PCR产物进行半定量分析,比较两组间差异.结果:MDR3基因mRNA的表达在ICP患者和正常孕妇组间差异无统计学意义(P＞0.05).结论:MDR3基因mRNA的表达异常可能与中国皖南地区ICP发生无关或关联很小,中国人ICP的发生可能存在其他的发病机制.     

妊娠期肝内胆汁淤积症患者多药耐药3基因外显子8和12突变的研究

目的:研究多药耐药3(MDR3)基因外显子8和12突变与妊娠期肝内胆汁淤积症(ICP)的关系,探讨ICP的发生机制。方法:从29例ICP患者及32例正常孕妇的外周血中提取DNA,聚合酶链反应(PCR)扩增MDR3基因外显子8和12,对PCR产物进行DNA测序分析。结果:ICP患者和对照组PCR均扩增出目的片段,且存在多态性位点G711A及A1260G,两组的8号外显子基因型频率和12号外显子基因型频率比较,差异均有统计学意义(P<0.05,P<0.01)。结论:云南临沧地区ICP的发生可能与MDR3外显子8和12的突变有关。     

妊娠期肝内胆汁淤积症MDR3基因突变的研究

目的:了解妊娠期肝内胆汁淤积症(ICP)患者MDR3基因外显子突变的分布,探讨此基因在ICP发病机制中的作用。方法:收集30例ICP孕妇,检测其肝功能、血清总胆汁酸(TBA)、γ-谷胺酰转肽酶(γ-GT)水平,同时用聚合酶链反应-单链构象多态性(PCR-SSCP)技术分析ICP患者MDR3基因5个外显子的突变情况。结果:4例ICP孕妇血清γ-GT升高。所有ICP患者及60例正常妊娠妇女PCR均扩增出目的片段,但SSCP分析没有发现异常迁移条带。结论:在MDR3基因突变频率较高的5个外显子中,本地区ICP孕妇未发现有突变。MDR3基因突变可能不是本地区ICP患者发病的主要原因。     

P-糖蛋白胎盘转运活性的个体差异及其与ABCB1基因多态性的相关性研究

目的:探讨人体胎盘上的P-糖蛋白(P-gp)转运活性是否存在个体差异,以及ATP结合盒B亚家族成员1转运蛋白基因(ABCB1)的基因多态性与胎盘上P-gp转运活性的相关性。方法:选取300例成熟的胎盘,提取胎盘微绒毛质膜囊泡(MVMVs),荧光标记法检测MVMVs的P-gp转运活性;Snapshot法检测胎盘上ABCB1基因9个单核苷酸多态性(SNPs)的基因型,并与相应MVMVs上P-gp转运活性进行相关性分析。结果:成功提取259例MVMVs,259例MVMVs的单位蛋白P-gp转运活性为0.111±0.047/mg。ABCB1基因rs12720464、rs28746504、rs57806198、rs1128503、rs2032582、rs1045642位点不同基因型与P-gp转运活性的个体差异无显著相关。结论:人体胎盘上的P-gp转运活性存在个体差异,但本研究探讨的ABCB1基因的9个SNPs可能不是影响人体胎盘上P-gp转运活性的关键因素。     

妊娠肝内胆汁淤积综合征的遗传学研究进展

妊娠肝内胆汁淤积症(ICP)病因复杂,遗传因素在发病机制中起相当关键作用.将胆汁淤积基因FIC、BSEP以及MDR3等作为ICP侯选基因,综述功能克隆、定位克隆及突变功能研究的进展.     

妊娠肝内胆汁淤积症患者血清甘胆酸水平变化与胎盘细胞凋亡调节基因表达的关系

目的　探讨妊娠肝内胆汁淤积症 (ICP)患者血清甘胆酸水平变化与胎盘细胞凋亡的关系 ,进一步分析ICP患者胎盘功能减退的可能机制。方法　应用放射免疫方法 ,测定 30例ICP患者(ICP组 )及 2 7例正常孕妇 (对照组 )分娩前血清甘胆酸水平 ,应用免疫组化方法测定两组孕妇胎盘细胞凋亡调节基因bax和bcl 2的表达。结果　 (1)ICP组甘胆酸水平为 (5 1 8± 5 9) μmol/L ,对照组为(9 4± 5 6 ) μmol/L ,两组比较 ,差异有显著性 (P <0 0 5 )。 (2 )ICP组胎盘合体滋养细胞bax阴性 2例 ,弱阳性 9例 ,中等阳性 11例 ,强阳性 8例 ;bcl 2弱阳性 12例 ,中等阳性 12例 ,强阳性 6例。对照组bax阴性 9例 ,弱阳性 13例 ,中等阳性 4例 ,强阳性 1例 ;bcl 2弱阳性 3例 ,中等阳性 4例 ,强阳性 2 0例。两组比较 ,ICP组bax表达阳性率显著高于对照组 (P <0 0 0 0 5 ) ,而bcl 2的表达阳性率又显著低于对照组 (P <0 0 0 0 5 )。 (3)孕妇血甘胆酸水平与胎盘bax表达阳性率呈线性正相关 (P <0 0 0 5 ) ,与胎盘bcl 2表达呈线性负相关 (P <0 0 0 5 )。结论　ICP患者血中高水平的甘胆酸使胎盘合体滋养细胞bax基因过度表达 ,这可能是ICP患者胎盘功能减退的机制之一。     

The role of genetic mutations in intrahepatic cholestasis of pregnancy

ObjectiveIntrahepatic cholestasis of pregnancy (ICP) is a liver disorder of pregnancy characterized by pruritus, elevated liver enzymes and fasting serum bile acids. Genetic predisposition has been suggested to play a role in its etiology and mutations in the ATP8B1(OMIM 1602397) (FIC1), ABCB11(OMIM 1603201) (BSEP), and ABCB4(OMIM 1171060) (MDR3) genes have been implicated.In the present study, we aimed to investigate the possible role of ATP8B1, ABCB11, and ABCB4 gene mutations in the patients with ICP.Materials and methodsA total of 25 patients who were diagnosed with ICP were included in the study. Genetic test results and mutation status of the patients as assessed by the next-generation sequencing technology were retrospectively retrieved from the hospital database.ResultsOf all patients, significant alterations in the ATP8B1 (n = 2), ABCB11 (n = 1), and ABCB4 (n = 7) genes were observed in 10 patients using the molecular analysis testing. All these alterations were heterozygous. Of these alterations, four were reported in the literature previously, while six were not. Using the in-silico parameters, there was a pathogenic alteration in the ABCB4 gene in one patient, while there was no clinically relevant alteration in the other gene mutations in the remaining nine patients.ConclusionConsidering the fact that the alterations were compatible with clinical presentations of the ICP patients and the incidence of these mutations is low in the general population, we believe that our study results are clinically relevant. Further molecular genetic tests in ICP patients and functional studies supporting the results would shed light into the clinical importance of these alterations.     

Effect of the maternal-fetal interface immunoregulation on the occurrence of intrahepatic cholestasis of pregnancy

Maternal immune tolerance of the fetus is indispensable for a healthy pregnancy. Currently, the study of the immune microenvironment of the maternal-fetal interface has been a heated topic in reproductive immunology research. More and more studies show that the immune imbalance in the maternal-fetal interface plays a very important role in the incidence of intrahepatic cholestasis of pregnancy(ICP). However, the precise etiology and mechanism of immune imbalance in the occurrence of ICP is still unknown. In order to clarify the potential immunologic mechanisms of ICP, this review summarizes the recent studies of the decidual immunology microenvironment and the potential immunologic mechanisms related to the development of ICP.     

肿瘤干细胞相关基因ABCB1、ABCG2表达与宫颈上皮恶变及发展关系的研究

目的:探讨肿瘤干细胞相关基因ABCB1、ABCG2表达与宫颈癌形成及临床病理参数之间的关系。方法:应用组织芯片技术和免疫组织化学检测宫颈浸润癌34例、微小浸润癌30例、CINⅢ30例、宫颈慢性炎症30例患者ABCB1、ABCG2的表达,并与临床病理资料进行相关性分析。结果:ABCB1在浸润癌、微小浸润癌、CINⅢ、宫颈慢性炎症中的阳性表达率分别是为76%(26/34)、60%(18/30)、40%(12/30)、20%(6/30),其阳性表达率随病变级别升高而明显增加;ABCB1在浸润癌中表达水平与肿瘤分化程度、TNM分期、淋巴结转移密切相关(P<0.05),与肿瘤体积无关(P>0.05);ABCG2在浸润癌、微小浸润癌、CINⅢ、宫颈慢性炎症中的阳性表达率分别为80%(27/34)、70%(21/30)、40%(12/30)、30%(9/30),其阳性表达率随病变级别增加而上升;ABCG2表达水平与肿瘤体积、TNM分期密切相关(P<0.05),与淋巴结转移、肿瘤分化程度无关(P>0.05)。结论:ABCB1、ABCG2在促进宫颈癌变过程中发挥主要作用,并且ABCB1的阳性表达是提示宫颈癌预后不良的客观指标。     

妊娠肝内胆汁淤积症患者脐带血管病变及血管活性物质的表达与胎儿窘迫发生的关系

目的 探讨妊娠肝内胆汁淤积症(ICP)患者脐带血管病理改变、脐带血管活性物质表达的变化与胎儿窘迫发生的关系.方法 应用HE染色法制片,光镜下观察25例ICP伴有胎儿窘迫(ICP窘迫组)、25例ICP不伴胎儿窘迫(ICP对照组)以及27例正常妊娠妇女(正常妊娠组)新生儿脐带血管病理改变;应用免疫组化辣根过氧化物酶-生物素标记(SABC)法测定内皮型一氧化氮合酶(eNOS)、诱导型一氧化氮合酶(iNOS)及内皮素1(ET-1)蛋白在各组脐静脉内皮细胞中的表达量,以平均吸光度(A)值表示;应用循环酶法测定脐静脉血总胆酸水平并进行相关性分析.结果 (1)脐静脉血总胆酸水平:ICP窘迫组为(19.0±2.3)μmol/L,ICP对照组为(9.0±1.7)μmol/L,正常妊娠组为(4.4±1.5)μmol/L,各组分别比较,差异均有统计学意义(P＜0.05).(2)脐静脉病理改变:ICP患者脐静脉内皮细胞单层扁平结构丧失,细胞向管腔耸立,梭形排列,细胞排列不均甚至脱落.ICP窘迫组患者脐静脉内皮细胞出现此病理改变的发生率(92%,23/25)明显高于ICP对照组(68%,17/25),差异有统计学意义(P＜0.05).(3)脐静脉内皮细胞中eNOS蛋白表达量:ICP窘迫组为0.09±0.06,ICP对照组为0.21±0.08,正常妊娠组为0.47±0.07,各组分别比较,差异均有统计学意义(P＜0.05).脐静脉内皮细胞中iNOS蛋白表达量:ICP窘迫组为0.20±0.04,ICP对照组为0.21±0.05,正常妊娠组为0.26±0.04,两ICP组分别与正常妊娠组比较,差异均有统计学意义(P＜0.01,P＜0.05);而ICP窘迫组与ICP对照组间比较,差异无统计学意义(P＞0.05).(4)脐静脉内皮细胞中ET-1蛋白表达量:ICP窘迫组为0.49±0.08,ICP对照组为0.32±0.07,正常妊娠组为0.14±0.06,两ICP组分别与正常妊娠组比较,差异均有统计学意义(P＜0.01,P＜0.05).(5)脐静脉血总胆酸水平与其病理改变的关系:脐静脉血总胆酸水平升高是脐静脉病理改变的危险因素;且与脐血管内皮细胞eNOS、iNOS的蛋白表达量呈负相关关系(r1=-0.88、r2=-0.45,P＜0.01);与脐血管内皮细胞ET-1蛋白的表达量呈正相关关系(r3=0.79,P＜0.01).结论 ICP患者脐静脉血高胆酸状态可能损伤脐静脉内皮细胞,且与其eNOS、iNOS蛋白表达下调、ET-1蛋白表达上调有关,脐静脉的这些改变可能与ICP患者胎儿窘迫的发生有关.     

Functional changes of mouse placental multidrug resistance phosphoglycoprotein (ABCB1) with advancing gestation and regulation by progesterone

Multidrug resistance phosphoglycoprotein (ABCB1) has been shown to limit maternal-fetal transfer by actively excluding ABCB1 substrates. The authors have previously demonstrated a marked decrease in placental ABCB1 expression in the human and mouse with advancing gestation. In the present study, it is hypothesized that the decrease in ABCB1 expression will result in increased transplacental transfer of ABCB1 substrates over the second half of gestation and that progesterone exhibits a regulatory role on placental ABCB1 expression and function. The authors demonstrate a significant increase in transplacental transfer of [(3)H]digoxin (an ABCB1 substrate) in late gestation (E18.5; P < .001) when compared to earlier embryonic days. Furthermore, maternal plasma progesterone levels did not influence expression or function of ABCB1. The authors conclude that the fetus is increasingly exposed to both endogenous and exogenous substrates of ABCB1 present in the maternal circulation with advancing gestation and that progesterone does not elicit a regulatory role on placental ABCB1 expression or function in vivo.     

Folate transporter expression decreases in the human placenta throughout pregnancy and in pre-eclampsia

The transport of folate across the placenta involves a number of different receptors including folate receptor-alpha (FR-α), reduced folate carrier (RFC) and proton coupled folate transporter (PCFT). In addition there are a number of ATP-dependent transporters which have also recently been shown to be involved in folate transport; these include ABCB1, ABCC2 and BCRP (ABCG2). The aim of the current study was to characterise the placental mRNA and protein expression of these folate transporters throughout gestation and also to see if expression is altered in pre-eclampsia. Placental tissue was collected from women undergoing termination of pregnancy (TOP) and from women undergoing elective Caesarean section. To investigate mRNA expression quantitative real time PCR was used with gene specific oligonucleotide primers to FR-α, RFC, PCFT, ABCB1, ABCC2, BCRP and the reference gene YWHAZ. Protein expression was also characterised using immunohistochemistry of paraffin embedded placental tissue. Both protein and mRNA expression of all transporters examined decreased as the gestation progressed. Expression of FR-α and PCFT mRNA and protein were decreased in pre-eclampsia compared with normal term pregnancy. The higher levels of expression of FR-α, RFC, PCFT, ABCB1, ABCC2 and BCRP in early pregnancy indicate that these transporters may have an important role in the establishment and development of the placenta, with expression reducing in preparation for parturition. Reductions in FR-α and PCFT in pre-eclampsia may be a mechanism involved in the pathogenesis of pre-eclampsia by limiting placental folate uptake resulting in reduced levels of angiogenesis, cell proliferation and antioxidant protection.     

Changes in hepatobiliary enzymes and its isoenzymes in intrahepatic cholestasis in pregnancy]

Serum alkaline phosphatase (AKP), gamma-glutamyl transpeptidase (gamma-GT), 5'-nucleotidase (5'-NT), leucine aminopeptidase (LAP), AKP gamma-GT isoenzymes, and lipoprotein-X (LP-X) were measured in 97 normal pregnant women and 40 patients with intrahepatic cholestasis of pregnancy (ICP). It was found that in ICP the changing patterns in the four hepatobiliary enzymes were different in different gestational weeks of 3 rd trimester. The changes of gamma-GT and 5'NT were more significant, especially the latter. Six bands were found both in serum AKP and gamma-GT isoenzymes. In ICP the rate of occurrence of AKP1 and AKP2 isoenzymes were elevated. Thus, gamma-GT, 5'-NT, AKP and gamma-GT isoenzymes might be more sensitive parameters for monitoring intrahepatic cholestasis of pregnancy.     

胎盘法尼醇X受体的表达及其与妊娠期肝内胆汁淤积症关系的研究

目的:探讨法尼醇X受体(FXR)在正常晚孕胎盘和妊娠期肝内胆汁淤积症(ICP)胎盘的表达,及其与母血、脐血总胆汁酸(TBA)水平的关系,分析胎盘FXR在ICP病理机制中的作用.方法:收集ICP患者(ICP组)及正常晚孕妇女(对照组)胎盘组织及母血、脐血各33例,并将ICP患者根据母血血清TBA是否≥40 μmoL/L将ICP组分为轻度ICP组和重度ICP组.并测定母血、脐血TBA水平和胎盘组织中FXR mRNA的相对表达量.结果:①羊水胎粪污染的发生率:ICP组羊水污染发生率高于对照组(χ~2:7.543,P=0.013);重度ICP组高于轻度ICP组(χ~2=7.637,P=0.013);②胎盘组织中FXR mRNA的表达情况:ICP组胎盘FXR mRNA表达量高于对照组(z=-2.391,P=0.017);重度ICP组胎盘FXR mRNA表达量高于轻度ICP组(z=-2.391,P=0.017);③ICP组胎盘FXR mRNA表达量与母血、脐血TBA呈正相关(r_s=0.348,P=0.047;r_s=0.284,P=0.027);对照组胎盘FXR mRNA表达量与母血、脐静脉血TBA无相关性(r_s=-0.068,P=0.716;r_s=0.010,P=0.959).结论:ICP时增高的胆汁酸水平上调胎盘FXRmRNA的表达,胎盘FXR表达增加可能为ICP时胎盘的一种对抗胎儿胆汁淤积的保护性机制.     

妊娠肝内胆汁淤积症患者胎儿缺氧的影响因素

目的　探讨妊娠肝内胆汁淤积症 (ICP)患者胎儿缺氧机理及其相关因素。方法　分别测定ICP患者 (30例 ,ICP组 )及正常妊娠妇女 (30例 ,对照组 )新生儿脐动脉血胆汁酸总量 (TBA)、次黄嘌呤 (HX)、内皮素 (ET)及有核红细胞 (NRBC)计数。结果　 (1)ICP组缺氧者 (10例 )脐血HX水平为(18.6 8± 15 .73) μmol/L ,明显高于ICP组无缺氧者 (2 0例 ) [(6 .87± 2 .82 ) μmol/L ]及对照组 [(6 .81±2 .83) μmol/L](P <0 .0 1) ;但NRBC[(4 .2 0± 2 .49)个 / 10 0白细胞 ,(3.40± 2 .2 6 )个 / 10 0白细胞 ,(3.5 0± 1.74)个 / 10 0白细胞 ]及ET水平 [(72 .44± 12 .2 3)ng/L ,(70 .16± 2 6 .6 1)ng/L ,(6 7.2 7± 43.5 6 )ng/L],各组相似 (P >0 .0 5 )。 (2 )ICP组缺氧者脐血TBA为 (2 3.77± 11.82 ) μmol/L ,明显高于ICP组无缺氧者 (14.86± 5 .46 ) μmol/L ,ICP组无缺氧者脐血TBA又高于对照组 [(9.2 8± 4.39) μmol/L](P <0 .0 1) ;且ICP组脐血TBA与HX水平呈正相关 (r=0 .6 89,P <0 .0 1) ;ICP组羊水胎粪污染率明显高于对照组 (5 3.3% ,13.3% ;P <0 .0 1) ,ICP组羊水胎粪污染者脐血TBA[(2 1.44± 9.92 ) μmol/L],明显高于羊水清亮者 [(13.6 9± 5 .74) μmol/L],差异有显著性 (P <0 .0 5 )。 结论　ICP时 ,