Na~+牛磺胆盐共转运体(NTCP)和顶端钠依赖性胆盐转运体(ASBT)遗传药理学研究
钠牛磺胆酸共转运多肽缺陷病临床特征及SLC10A1基因突变分析

!>?30!钠牛磺胆酸共转运多肽缺陷病临床特征及SLC10A1基因突变分析杨峰霞,曾凡森,谭丽梅,龚 余,刘玲丽,徐 翼广州市妇女儿童医疗中心感染性疾病科,广州510120摘要:目的 总结钠牛磺胆酸共转运多肽(NTCP)缺陷病的临床和基因突变特征。
方法 选取2020年6月—2021年6月于广州市妇女儿童医疗中心经基因检测确诊的10例NTCP缺陷病患儿(年龄<18岁),分析一般资料(性别、年龄、身高、体质量、家族史和既往病史)、临床表现、病情转归、实验室检查(血常规、肝功能、嗜肝病毒、自身免疫性肝炎筛查)及基因突变检测结果。
结果 10例患儿生长发育均正常,其中男8例,女2例;确诊年龄3~37个月。
首次就诊病因包括新生儿黄疸延长(5/10,50%)、转氨酶升高(2/10,20%)、体检(2/10,20%)和肺炎(1/10,10%)。
所有患儿确诊时血清TBA水平均明显升高;ALT、AST水平升高2例;TBil水平升高1例,且以DBil水平升高为主(DBil/TBil>50%)。
经第二代基因测序,10例患儿均为SLC10A1基因纯合突变:c.800C>T(p.Ser267Phe,chr14∶70245193)。
结论 尽管NTCP缺乏症往往无明显症状,但部分患儿早期可表现为婴儿胆汁淤积症,对于显著而持续的高胆汁酸血症,且血清总TBA水平与其他肝功能指标的变化趋势不一致时,应考虑NTCP缺陷病可能。
关键词:代谢疾病;钠牛磺胆酸共转运多肽;SLC10A1基因;胆汁淤积基金项目:广州市卫生健康科技项目(20201A011036)ClinicalfeaturesofsodiumtaurocholatecotransportingpolypeptidedeficiencyandananalysisofSLC10A1genemutationYANGFengxia,ZENGFansen,TANLimei,GONGYu,LIULingli,XUYi.(DepartmentofInfectiousDiseases,GuangzhouWomenandChil dren’sMedicalCenter,Guangzhou510120,China)Correspondingauthor:XUYi,xuyi70@163.com(ORCID:0000-0001-8971-9334)Abstract:Objective Toinvestigatetheclinicalandgenemutationfeaturesofsodiumtaurocholatecotransportingpolypeptide(NTCP)de ficiency.Methods Atotalof10children,aged<18years,whowerediagnosedwithNTCPdeficiencyinGuangzhouWomenandChil dren’sMedicalCenterfromJune2020toJune2021wereenrolled,andrelateddatawereanalyzed,includinggeneralinformation(sex,age,bodyheight,bodyweight,familyhistory,andpasthistory),clinicalmanifestation,diseaseoutcome,laboratoryexamination(routinebloodtest,liverfunction,hepatotropicvirus,andautoimmunehepatitisscreening),andgenemutation.Results All10childrenhadnor malgrowthanddevelopment,amongwhomtherewere8boysand2girls,withanageof3-37monthsatthetimeofdiagnosis.Theetiologyofchildrenattendingthehospitalforthefirsttimewasprolongedjaundice(5/10,50%),elevationofaminotransferases(2/10,20%),ab normalphysicalexaminationresults(2/10,20%),andpneumonia(1/10,10%).Atthetimeofdiagnosis,allchildrenhadasignificantincreaseinserumtotalbileacid(TBA),2childrenhadincreasesinalanineaminotransferaseandaspartateaminotransferase,and1childhadanincreaseintotalbilirubin(TBil),mainlydirectbilirubin(DBil)(DBil/TBilratio>50%).Second-generationgenesequencingshowedthatall10childrenhadahomozygousmutationoftheSLC10A1gene,i.e.,c.800C>T(p.Ser267Phe,chr14∶70245193).Conclusion AlthoughNTCPdeficiencyoftenhasnosymptoms,someofthechildrenmaymanifestasinfantcholestasisintheearlystage.ThepossibilityofNTCPdeficiencyshouldbeconsideredwhenthereispersistenthypercholanemiaandthechangingtrendofserumTBAisnotconsistentwiththatofotherliverfunctionparameters.Keywords:MetabolicDiseases;Sodium-TaurocholateCotransportingPolypeptide;SLC10A1Gene;CholestasisResearchfunding:GuangzhouHealthScienceandTechnologyProject(20201A011036)DOI:10.3969/j.issn.1001-5256.2022.03.022收稿日期:2021-08-17;录用日期:2021-09-20通信作者:徐翼,xuyi70@163.com 钠牛磺胆酸共转运多肽(sodiumtaurocholatecotrans-portingpolypeptide,NTCP)缺陷病是由于溶质转运蛋白家族10成员1(solutecarrierfamily10member1,SLC10A1)基因突变引起的一种遗传性胆汁酸代谢病。
胆汁酸代谢在原发性胆汁性胆管炎发病机制中的作用

胆汁酸代谢在原发性胆汁性胆管炎发病机制中的作用贾皖婷,刘晓晓,邰文琳昆明医科大学第二附属医院检验科,昆明650032摘要:原发性胆汁性胆管炎(PBC)是一种胆汁淤积性自身免疫性肝病,以中老年女性高发,小胆管淋巴细胞浸润和胆汁淤积为主要特征。
临床表现以疲惫和胆汁淤积造成的瘙痒为主。
目前被批准的治疗药物熊去氧胆酸和奥贝胆酸,主要是通过调节胆汁酸代谢,特异且有效的改善胆汁淤积而起作用。
本文介绍了胆汁酸生理及疾病状态下的病理改变,归纳了胆汁酸代谢参与疾病发病机制的可能方式,总结了目前针对胆汁酸代谢的疾病治疗方法。
指出PBC胆汁酸代谢改变主要与阴离子交换器2缺陷、胆汁酸代谢的转运体和核受体先天遗传变异及后天适应性改变、肠道菌群结构发生改变有关。
关键词:原发性胆汁性胆管炎;胆汁酸类和盐类;病理过程基金项目:国家自然科学基金(82060385)RoleofbileacidmetabolisminthepathogenesisofprimarybiliarycholangitisJIAWanting,LIUXiaoxiao,TAIWenlin.(DepartmentofClinicalLaboratory,TheSecondAffiliatedHospitalofKunmingMedicalUniversity,Kunming650032,China)Correspondingauthor:TAIWenlin,taiwenlinlin@sohu.com(ORCID:0000-0002-8278-929X)Abstract:Primarybiliarycholangitis(PBC)isacholestaticautoimmuneliverdiseasecharacterizedbyahighincidencerateinmiddle-agedandelderlywomen,lymphocyteinfiltrationinsmallbileducts,andcholestasis.Mainclinicalmanifestationsincludefatigueandpruri tuscausedbycholestasis.UrsodeoxycholicacidandobeticholicacidarecurrentlyapprovedtherapeuticdrugsforPBCandexertatherapeuticeffectbyregulatingbileacidmetabolismandspecificallyandeffectivelyimprovingcholestasis.Thisarticleintroducesthephysiologicalandpathologicalchangesofbileacidsindiseasestatesandsummarizesthepossiblewaysinwhichbileacidmetabolismisinvolvedinthepatho genesisofdiseasesandthecurrenttreatmentmethodsforbileacidmetabolism.ItispointedoutthatthechangesofbileacidmetabolisminPBCaremainlyassociatedwithanionexchanger2deficiency,innategeneticvariationandacquiredadaptivechangesofbileacidmetabolismtransportersandnuclearreceptors,andchangesinthestructureofintestinalflora.Keywords:PrimaryBiliaryCholangitis;BileAcidsandSalts;PathologicProcessesResearchfunding:NationalNaturalScienceFoundationofChina(82060385)DOI:10.3969/j.issn.1001-5256.2022.10.031收稿日期:2022-03-01;录用日期:2022-04-15通信作者:邰文琳,taiwenlinlin@sohu.com 原发性胆汁性胆管炎(primarybiliarycholangitis,PBC)属于胆汁淤积性肝病的一种,常在具有自身免疫遗传易感性的中老年女性中发生。
胆汁淤积与胆汁酸转运蛋白关系的研究进展

胆汁淤积与胆汁酸转运蛋白关系的研究进展王安红;刘路【摘要】胆汁不仅能够帮助消化和吸收脂肪,还能将某些代谢产物从肝脏排出体外,对正常的代谢活动起了至关重要的作用.机体内的胆汁在正常生理状况下处于肠肝循环的动态平衡之中,当胆汁的生成或是流动受到影响时就会引起胆汁淤积.胆汁酸作为胆汁主要成分之一,它的合成、转运、分泌以及重吸收的任何一个环节出现差错,胆汁的肝肠循环都会受到影响.%The bile not only can help digestion and absorption of fat,but also eliminate some metabolism product from the liver,which plays an important role on the normal metabolic activities. The bile in vivo is in the dynamic balance of enterohepatic circulation under the normal physiological conditions. But,the disorder of the bile generation or flow will cause cholestasis. The bile acid is a main component of the bile,when any error happens during thesynthesis,transport,secretion and reabsorption,the enterohepatic circulation will be affected.【期刊名称】《医学综述》【年(卷),期】2013(019)001【总页数】3页(P16-18)【关键词】胆汁淤积;胆汁酸;转运体【作者】王安红;刘路【作者单位】天津中医药大学中医药研究院,天津市中药药理重点实验室,天津,300193;河南大学药学院,河南,开封,475001【正文语种】中文【中图分类】R966胆汁淤积简称淤胆,是由胆汁生成障碍或胆汁流动障碍所致的一组疾病共同的临床症状,又名胆汁淤积综合征。
顶端钠依赖性胆汁酸转运蛋白(ASBT)在肝胆疾病中的作用

顶端钠依赖性胆汁酸转运蛋白(ASBT)在肝胆疾病中的作用谢晓暄,杜丽娜,郭紫云,杨燕国家儿童医学中心,首都医科大学附属北京儿童医院中医科,北京 100045通信作者:杨燕,***************(ORCID: 0000-0003-1070-9614)摘要:顶端钠依赖性胆汁酸转运蛋白(ASBT)是负责胆汁酸肠道重吸收的关键转运体,对维持胆汁酸和胆固醇稳态起重要作用,其表达受到转录因子、核受体和肠道微生物等多种因素的调控。
ASBT的表达和功能异常会导致胆汁酸及胆固醇代谢紊乱,引起多种肝胆相关疾病。
目前,ASBT作为一种治疗靶点已受到广泛关注。
本文阐述了ASBT的生物学特征及表达调控机制,并对ASBT在肝胆疾病中的作用进行了综述,为相关疾病的治疗提供新方向。
关键词:顶端钠依赖性胆汁酸转运蛋白;胆汁酸类;胆汁淤积基金项目:国家自然科学基金(82205184);北京市属医院科研培育计划(PZ2022027)Role of apical sodium-dependent bile acid transporter in hepatobiliary diseasesXIE Xiaoxuan, DU Lina, GUO Ziyun, YANG Yan.(Department of Traditional Chinese Medicine, National Center for Children’s Health, Beijing Children’s Hospital, Capital Medical University, Beijing 100045, China)Corresponding author: YANG yan,***************(ORCID: 0000-0003-1070-9614)Abstract:Apical sodium-dependent bile acid transporter (ASBT) is a key transporter responsible for intestinal reabsorption of bile acid and plays an important role in maintaining bile acid and cholesterol homeostasis, and its expression is regulated by various factors including transcription factors, nuclear receptors, and intestinal microflora. The abnormal expression and function of ASBT can lead to disorders in the metabolism of bile acid and cholesterol, causing a variety of hepatobiliary diseases. At present, ASBT has attracted wide attention as a therapeutic target. This article elaborates on the biological characteristics and expression regulation mechanism of ASBT and reviews the role of ASBT in hepatobiliary diseases, in order to provide a new direction for the treatment of related diseases.Key words:Apical Sodium Dependent Bile Acid Transporter; Bile Acid; CholestasisResearch funding:National Natural Science Foundation of China (82205184);Bejing Municipal Administration of Hospital Incubating Program (PZ2022027)胆汁酸(bile acid,BA)肝肠循环是维持胆酸池稳态的重要调控环节,位于回肠末端的顶端钠依赖性胆汁酸转运蛋白(apical sodium-dependent bile acid transporter,ASBT)是负责BA肠道重吸收的关键转运体。
2例钠牛磺胆酸共转运多肽缺陷病患儿临床分析

2例钠牛磺胆酸共转运多肽缺陷病患儿临床分析作者:孙文君于飞来源:《中国医药导报》2020年第17期[摘要] 钠牛磺胆酸共转运多肽(NTCP)缺陷病是近年来新发现的一种遗传性胆汁酸代谢障碍性疾病,本研究旨在提高对NTCP缺陷病的认识,选取华中科技大学附属湖北省妇幼保健院儿童内分泌遗传代谢科分别以生长发育落后及黄疸就诊的2例患儿,虽临床表现不同,但均发现有顽固性的高胆汁酸血症,并伴有25-羟维生素D下降,行基因分析发现SLC10A1突变,临床确诊为NTCP缺陷病,经积极对症治疗后临床症状缓解,预后较好。
该研究提示,对于显著而持续性的高胆汁酸血症的新生儿及儿童患者,需考虑NTCP缺陷病可能。
NTCP缺陷病患儿远期可能出现身材矮小等生长发育落后情况,生长激素或可改善NTCP缺陷病患者的终身高。
[关键词] 钠牛磺胆酸共转运多肽缺陷病;高胆汁酸血症;SLC10A1基因突变;患儿[中图分类号] R596.1 [文献标识码] A [文章编号] 1673-7210(2020)06(b)-0185-04Clinical analysis of two pediatric patients with sodium taurocholate cotransporting polypeptide deficiencySUN Wenjun YU fei▲Department of Endocrine Genetic Metabolism in Children, Maternal and Child Hospital of Hubei Province, Tongji Medical College Huazhong University of Science and Technology, Hubei Province, Wuhan 430000, China[Abstract] Sodium taurocholate cotransporting polypeptide (NTCP) deficiency is a newlydiscovered hereditary bile acid metabolic disorder in recent years. The aim of this research is to improve the understanding of NTCP deficiency. Two cases who presented with failure to thriveand jaundice in Department of Endocrine Genetic Metabolism in Children,Maternal and Child Hospital of Hubei Province, Tongji Medical College Huazhong University of Science and Technology were selected. Although the clinical manifestations were different, refractory hyperbile acidemia was found in all patients, and accompanied by a decrease in 25-hydroxy vitamin D. Genetic analysis revealed SLC10A1 mutation, which was clinically diagnosed as NTCP deficiency. After positive symptomatic treatment, the clinical symptoms were relieved and the prognosis was good. This study suggests that NTCP deficiency should be considered in neonates and children with significant and persistent hyperbile acidemia. Pediatric patients with NTCP deficiency may suffer from stunted growth and development in the long term and growth hormone may improve the lifetime height of patients with NTCP deficiency.[Key words] Sodium taurocholate cotransporting polypeptidedeficiency;Hypercholanemia;SLC10A1 gene mutation;Pediatric patients钠牛磺胆酸转运多肽(sodium taurocholate cotransporting polypeptide,NTCP)缺陷病是由于SLC10A1基因变异引起的一种遗传性胆汁酸代谢病,NTCP主要表达于肝、肾、胰腺等组织,分子量约为55 kD,主要功能是以钠依赖的方式,将血浆中的结合型胆汁酸摄取入肝细胞内参与某些激素的代谢,进而在肝肠循环中发挥作用[1],同时可转运某些与胆盐结合的药物,是潜在的药物作用靶点[2]。
新生儿胆汁淤积症胆汁酸转运体和转录调控的研究进展

新生儿胆汁淤积症胆汁酸转运体和转录调控的研究进展宾淑铭1 杨秀芳1.2 1 广东医科大学 (湛江 524023)2 广东省中山市人民医院新生儿科(中山 528403)【摘 要】 新生儿引起肝内胆汁淤积是由感染、遗传代谢性疾病、胃肠外营养、基因突变等各种不同病因导致胆汁形成、分泌和排泄障碍。
胆汁在体内淤积会影响新生儿的生长发育,严重者出现肝纤维化、肝功能衰竭等不可逆的改变,其发病的机制涉及参与肝脏胆汁酸分泌的各种转运体、肝细胞膜转运蛋白转录和和转录后的调控等。
本文归纳总结近年来国内外关于胆汁酸转运体及其转录和转录后的调控,从而为此疾病的防治提供理论依据,为将来降低其发生率和改善预后。
【关键词】 胆汁淤积;转运体;生物机制;转录调控DOI :10. 3969 / j. issn. 1000-8535. 2023. 04. 019Research progress of bile acid transporters and transcriptional regulation in neonatal cholestasis BIN Shuming 1,YANG Xiufang 1.2 1 Guangdong Medical University ,Zhanjiang 524023,China2 Department of Neonatology ,ZhongShan City People ’s Hospital ,Zhongshan 528403,China【Abstract 】 Neonatal intrahepatic cholestasis is caused by infection ,genetic metabolic diseases ,parenteral nutrition ,gene mutation and other different causes leading to bile formation ,secretion and excretion disorders .Bile stasis in the body will affect the growth and development of the newborn ,and in severe cases ,irreversible changes such as liver fibrosis and liver failure will occur .The pathogenesis of bile stasis involves various transporters involved in the secretion of bile acids in the liver ,transcription and post transcription regulation of liver cell membrane transporters .In this paper ,we summarized the recent studies on bile acid transporters and their transcriptional and post transcriptional regulation at home and abroad ,so as to provide a theoretical basis for the prevention and treatment of this disease ,and to reduce its incidence and improve its prognosis in the future.【Key words 】 cholestasis ;transporter ;biological mechanism ;transcriptional regulation通信作者:杨秀芳,E-mail :·综 述·新生儿肝内胆汁淤积是指各种原因导致胆汁形成、分泌和排泄功能障碍,胆汁流不能正常流入十二指肠,从而导致胆红素、脂肪酸和其他物质在血液、肝脏中储积以及肠道中胆汁酸的不足的病理状态[1]。
以FXR为核心的胆汁酸代谢机制研究进展

Hans Journal of Biomedicine 生物医学, 2018, 8(4), 62-68Published Online October 2018 in Hans. /journal/hjbmhttps:///10.12677/hjbm.2018.84008Advanced Progression in the Mechanism of Bile Acid Metabolism Targeting FXRXiuli Yang1, Sicong Tian1, Bo Pang1, Baolong Li2, Yujuan Shan1*1Department of Food Science and Engineering, Harbin Institute of Technology, Harbin Heilongjiang2Center of Drug Safety Evaluation, Heilongjiang University of Chinese Medicine, Harbin HeilongjiangReceived: Oct. 4th, 2018; accepted: Oct. 19th, 2018; published: Oct. 26th, 2018AbstractBile acids are important physiological factors that facilitate the digestion & absorption of dietary lipids and fat-soluble vitamins in the gut. In addition, they also act as signaling molecules to regu-late glucose homeostasis, lipid metabolism and energy expenditure. Disorders of bile acid meta-bolism can lead to a series of diseases. The nuclear receptor farnesoid X receptor (FXR) is a spe-cific bile acid receptor which plays an important role in the metabolism of bile acids through the regulation of multiple metabolic pathways and of corresponding target genes. Consequently, FXR is targeted to be a new drug for the therapy of disorders related to bile acid metabolism. This ar-ticle reviews the recent progressions of FXR in regulating bile acid metabolism and its mechanism, which aims to provide scientific strategies for the prevention/treatment of bile acid metabolic disorders, and new drugs exploration.KeywordsBile Acids, Farnesoid X Receptor, Bile Acid Metabolism以FXR为核心的胆汁酸代谢机制研究进展杨修利1,田思聪1,庞博1,李宝龙2,单毓娟1*1哈尔滨工业大学食品科学与工程系,黑龙江哈尔滨2黑龙江中医药大学药物安全性评价中心,黑龙江哈尔滨收稿日期:2018年10月4日;录用日期:2018年10月19日;发布日期:2018年10月26日*通讯作者。
胆汁酸代谢与胆固醇结石病

胆汁酸代谢与胆固醇结石病蔡强;韩天权;蒋兆彦【摘要】胆汁酸是胆汁的主要成分,由胆固醇在肝脏内转化合成。
胆汁酸具有调节胆固醇饱和度和排除机体过多胆固醇的作用。
胆固醇过饱和是胆固醇结石病发病机制中的重要因素。
本文综述胆汁酸代谢与胆固醇结石病发病关系的研究进展。
%Bile acid, a major component of bile, is converted from cholesterol in the liver. It regulates the cholesterol saturation and eliminates excessive cholesterol in the body. Cholesterol supersaturation is regarded as an essential factor for pathogenesis of cholesterol gallstone disease. This paper reviewes the progress in metabolism of bile acid and its relation to cholesterol gallstone disease.【期刊名称】《上海医药》【年(卷),期】2015(000)018【总页数】4页(P3-6)【关键词】胆汁酸;胆固醇结石病;肝脏【作者】蔡强;韩天权;蒋兆彦【作者单位】上海交通大学附属瑞金医院外科上海消化外科研究所上海 200025;上海交通大学附属瑞金医院外科上海消化外科研究所上海 200025;上海交通大学附属瑞金医院外科上海消化外科研究所上海 200025【正文语种】中文【中图分类】R657.4+2胆固醇结石病(简称胆石病)是临床上常见疾病之一,在西方国家成年人中的发病率为15%~20%,我国为7%~10%,随着我国人民生活水平的提高、生活方式的改变,其发病率呈不断上升趋势[1]。
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Na~+/牛磺胆盐共转运体(NTCP)和顶端钠依赖性胆盐转运体
(ASBT)遗传药理学研究
研究背景:肝脏中合成的胆汁对于肠道吸收,消化脂类物质,以及胆固醇代谢平衡至关重要。
胆汁从肝脏分泌后储存在胆囊中,食物刺激后,排入十二指肠和小肠,在回肠末端,大部分胆汁被肠壁吸收,经门静脉回流到肝脏,被肝细胞重摄取后供再次分泌,胆汁每天经过数次肝肠循环,这一过程和肝脏和肠道上分布的一系列转运体密切相关,其中最主要的是两个solute carrier 10A家族(SLC10A)成员:表达在肝细胞基底膜的Na~+/牛磺胆盐共转运体(NTCP,SLC10A1)和表达在回肠壁腔侧膜上的顶膜钠依赖性胆盐转运体(ASBT,SLC10A2)。
NTCP负责降门静脉血中的胆盐摄取回肝细胞,而ASBT则负责小肠对胆盐的重吸收。
基因遗传多态性是蛋白质功能变异和个体差异的一个主要来源,可以预计NTCP和ASBT基因多态性可以造成转运体功能改变,进而影响胆汁的肝肠循环。
负责肠道中胆盐的重吸收的ASBT转运体抑制后,肠道胆盐丢失增加,肝脏通过增加代谢胆固醇产生胆酸来代偿,因此ASBT抑制药可以模拟和胆盐螯合剂(如胆盐结合树脂)类似的机制降低胆固醇,这在动物实验中得到了证实。
因此ASBT
可以作为降脂药物开发的新靶点。
本研究从400个中药提取物中筛选ASBT转运体抑制剂。
方法:(1)我们对50个韩国人DNA样本的SLC10A1和SLC10A2基因外显子和启动子区进行测序。
对发现的新的编码区非同义突变,在韩国、中国和越南人大样本中用pyrosequencing方法进行基因分型。
随后在转染的MDCK细胞和爪蟾卵母细胞模型上,以[~3H]牛磺胆酸和[~3H]雌酮为底物检测NTCP蛋白野生型和两个突变型的摄取功能,同时观察已知的
NTCP抑制药牛磺胆酸、碘溴酞钠和环孢霉素A对NTCP野生和突变型摄取标记底物的影响。
(2)将稳定转染ASBT的MDCK细胞株,接种到96孔板,以[~3H]牛磺胆酸为底物,观察多种中药乙醇提取物对ASBT转运体摄取活性的影响。
MTT法
测定中药提取物对细胞有无毒性作用。
结果:(1)我们在SLC10A1基因编码区发现4个SNP,分别是1号外显子的
G18A、G190A和G225A突变和4号外显子C800T(*2)突变。
其中G190A是一个新的非同义突变,G190A突变导致64位丙氨酸变为苏氨酸,C800T突变导致267
位丝氨酸转变为苯丙氨酸。
G190A在150名韩国人样本中发现3个杂合子(等位
基因频率为1%),而在366个中国汉族人样本和152个越南Viet Kinh族人中
未发现该突变。
对于*2突变,在韩国人、中国人和越南人中等位基因频率分别为3.1%、7.4%和9.2%。
在SLC10A2编码区发现3个SNP:G429C、G501T和G990A,其中G501T 突变导致171位丙氨酸变为丝氨酸,此外我们还在基因内含子和上游启动子区发现多个SNP,但没有发现编码区新的突变。
(2) C800T(Ser267Phe)突变使NTCP
对[~3H]牛磺胆酸的摄取能力几乎完全丧失,但仍保持正常的摄取[~3H]雌酮的能力,而G190A(Ala64Thr)突变,使NTCP摄取[~3H]牛磺胆酸的能力大大减弱,而对[~3H]雌酮没有摄取功能。
三种已知抑制剂牛磺胆酸、碘溴酞钠和环孢霉素A可以有效抑制NTCP野生型和两个突变体对同位素标记底物的摄取。
RT-PCR证实G190A和C800T突变并
不影响基因在转染细胞中的mRNA表达量。
此外爪蟾卵母细胞模型上,和注射野生型NTCP cRNA的细胞相比,注射NTCP(C800T) cRNA的卵母细胞没有摄取[~3H]牛磺胆酸的活性,而注射了NTCP (G190A) cRNA的卵母细胞摄取[~3H]牛磺胆酸
的能力也大大减低。
(3)从400个中药提取物中,我们筛选出24个对ASBT转运体摄取功能抑制效应较大的,并做了剂量依赖性抑制实验计算其IC50。
这些中药中,有些如茯苓,其主要成分和胆酸的结构类似,另外一些如甘草皂苷类本身有降胆固醇效应。
根据IC50的高低以及参考这些中药的临床药理作用,我们最后选取了其中的4种,MTT法发现这些中药提取物培养48小时,对细胞无毒性作用,为后续动物实验提供基础。
结论:(1)我们在韩国人中发现SLC10A1基因新的非同义突变
G190A(Ala64Thr),该突变在中国汉族人和越南Viet Kinh人中没有找到。
该突变在细胞水平摄取牛磺胆盐和硫酸雌酮的能力大大减弱。
(2)在96孔板体外细胞摄取实验平台上,我们从400种中药提取物中筛选出若干种ASBT抑制剂,这些物质降胆固醇效应将通过动物实验来验证。