張 莉,占 瓊,趙 軍,李建光,周 源,楊歡杰,王 寧
·論著·
新疆維吾爾族人群SLC22A1基因多態(tài)性頻率分布及糖尿病家族史對其突變的影響研究
張 莉1,占 瓊2,趙 軍3,李建光4,周 源1,楊歡杰1,王 寧5*
背景 轉(zhuǎn)運蛋白(OCT)是近年來備受關注的藥物轉(zhuǎn)運體,由SLC22A1基因編碼。SLC22A1基因具有顯著的遺傳多態(tài)性,已在多個種族中發(fā)現(xiàn)了多個基因突變,是引起2型糖尿病(T2DM)患者二甲雙胍生物利用度差異的重要原因。目的 研究新疆維吾爾族青年男性SLC22A1基因rs34059508、rs4646277位點等位基因和基因型的頻率分布,以及T2DM家族史對SLC22A1基因突變的影響,為T2DM患者基因?qū)蛐远纂p胍個體化治療提供理論依據(jù)。方法 2014年9月—2015年9月,招募新疆維吾爾族男性健康志愿者276例為研究對象。采集受試者外周血5 ml,提取DNA,采用Snapshot技術平臺分析受試者SLC22A1基因rs34059508、rs4646277位點等位基因、基因型頻率和基因突變情況。結果 SLC22A1基因rs34059508、rs4646277位點基因頻率分布符合Hardy-Weinberg遺傳平衡,具有群體代表性(χ2=0.009,P=0.976;χ2=0.246,P=0.620)。亞洲人群、高加索人群、非裔美國人群、新疆維吾爾族人群SLC22A1基因rs34059508位點等位基因及基因型頻率比較,差異有統(tǒng)計學意義(P<0.05);其中,新疆維吾爾族人群SLC22A1基因rs34059508位點等位基因A頻率低于高加索人群(P<0.001)。亞洲人群、漢族人群、新疆維吾爾族人群SLC22A1基因rs4646277位點等位基因及基因型頻率比較,差異有統(tǒng)計學意義(P<0.05);其中,新疆維吾爾族人群SLC22A1基因rs4646277位點等位基因T頻率高于漢族人群(P<0.017)。19例有T2DM家族史者中12例(63.2%)發(fā)生SLC22A1基因突變,208例無T2DM家族史者SLC22A1基因突變率為77.9%(162/208),差異無統(tǒng)計學意義(χ2=1.367,P=0.242)。結論 新疆維吾爾族男性SLC22A1基因rs34059508、rs4646277位點突變率分別為0.4%、5.8%;未發(fā)現(xiàn)T2DM家族史對SLC22A1基因突變產(chǎn)生影響。
糖尿病,2型;生物利用度;SLC22A1基因;多態(tài)性,單核苷酸;維吾爾族
糖尿病患者具有較高的患病率和較低的治療達標率,已成為全球性的公共衛(wèi)生問題。根據(jù)國際糖尿病聯(lián)合會(IDF)數(shù)據(jù),2014年中國有糖尿病患者9 629萬人,其中2型糖尿病(T2DM)是糖尿病的主要類型[1-2]。二甲雙胍是應用最為廣泛的降糖藥,也是我國指南推薦的一線用藥[3-4],具有抑制肝糖原合成、改善胰島素抵抗、保護胰島B細胞、減輕體質(zhì)量、調(diào)節(jié)血脂、保護心血管、降低C反應蛋白(CRP)水平等作用[5-8]。遺傳因素是引起T2DM患者二甲雙胍生物利用度差異的重要因素,而藥物轉(zhuǎn)運體的基因多態(tài)性又是其中更為重要的因素。轉(zhuǎn)運蛋白(OCT)是近年來備受關注的藥物轉(zhuǎn)運體,是溶質(zhì)轉(zhuǎn)運體超家族(SLC)重要成員。該蛋白由SLC22A1基因編碼,主要在肝臟中表達,可轉(zhuǎn)運二甲雙胍進入肝臟,對二甲雙胍的藥物代謝發(fā)揮極其重要作用。研究證明,不同種族SLC22A1~3基因多態(tài)性對二甲雙胍藥動學、藥效學、藥物間相互作用均有顯著影響[9-10]。SLC22A1基因位于染色體6q26,全長37 kb,含有11個外顯子和10個內(nèi)含子。SLC22A1具有顯著的遺傳多態(tài)性,已在多個種族中發(fā)現(xiàn)了多個基因突變,相當一部分基因突變可引起其功能改變,且多是導致OCT轉(zhuǎn)運效能降低甚至喪失[11-12]。
新疆維吾爾族人群因地理位置及文化信仰,較少與異族通婚,遺傳背景高度同源,是研究基因多態(tài)性的理想種族。本研究擬在維吾爾族健康人群中調(diào)查SLC22A1常見遺傳多態(tài)性的分布特征,為后續(xù)研究其多態(tài)性對二甲雙胍藥動學、藥效學影響,及嘗試個體化治療提供前期準備。
1.1 研究對象 2014年9月—2015年9月,招募新疆維吾爾族男性健康志愿者276例為研究對象,年齡18~25歲,平均年齡(20.9±1.2)歲。納入標準:(1)年齡18~30歲;(2)志愿者彼此無血緣關系;(3)同意參與本研究。受試者均簽署知情同意書,本研究獲得新疆醫(yī)科大學第一附屬醫(yī)院倫理委員會批準。
1.2 方法 由護士采集受試者外周血5 ml,置于乙二胺四乙酸(EDTA)抗凝管中,-80 ℃保存。加入細胞裂解液,10 000 r/min離心2 min(離心半徑為8 cm),向沉淀中加入200 μl緩沖液FG和2 μl蛋白酶K混合液,65 ℃水浴10 min,顛倒混勻。
加入200 μl異丙醇,顛倒充分混勻后以12 000 r/min離心2 min(離心半徑為8 cm)。加入500 μl無水乙醇,渦旋振蕩5 s,12 000 r/min離心2 min(離心半徑為8 cm),重復上一步后將離心管倒置在干凈的吸水紙上,空氣干燥DNA沉淀(至少5 min)。加入50 μl緩沖液TB,混勻,65 ℃加熱10~60 min溶解DNA。核酸蛋白定量儀檢測DNA濃度,1%瓊脂糖凝膠孔中上樣,120 V恒壓電泳30 min,使用凝膠成像儀觀察并保存結果。
將上述DNA稀釋到工作濃度5~10 ng/μl,引物均由歐易生物醫(yī)學有限公司合成,rs34059508位點引物序列上游:5′- TTCCTCCTGACCCCTGCAGTTT-3′,下游:5′- CACAGGGAGGAACACACCATCA-3′;rs4646277位點引物序列上游:5′- TGACCCACAGAGCTGTGACCTG-3′,下游:5′- AGCAGGAGGCAACTTCCCATTC-3′。PCR反應條件:變性95 ℃ 2 min,94 ℃ 20 s,65 ℃ 40 s,72 ℃ 1.5 min,11個循環(huán);退火94 ℃ 20 s,59 ℃ 30 s,72 ℃ 1.5 min,24個循環(huán)后72 ℃ 2 min;延伸:96 ℃ 1 min,96 ℃ 10 s,55 ℃ 5 s,60 ℃ 30 s,28個循環(huán)后保持4 ℃。延伸產(chǎn)物上ABI3730XL測序儀,Gene Mapper 4.1(Applied Biosystems Co.Ltd,USA)分析。
1.3 統(tǒng)計學方法 采用LDA 1.0軟件χ2檢驗判斷基因型頻率分布是否符合Hardy-Weinberg遺傳平衡,采用SPSS 17.0軟件進行統(tǒng)計學分析,計數(shù)資料的分析采用χ2檢驗。以P<0.05為差異有統(tǒng)計學意義,多重比較調(diào)整檢驗水準為0.05/比較次數(shù)。
2.1 Hardy-Weinberg遺傳平衡檢驗 SLC22A1基因rs34059508、rs4646277位點基因頻率分布符合Hardy-Weinberg遺傳平衡,具有群體代表性(χ2=0.009,P=0.976;χ2=0.246,P=0.620)。
2.2 不同種族人群SLC22A1基因rs34059508位點等位基因及基因型頻率比較 亞洲人群、高加索人群、非裔美國人群、新疆維吾爾族人群SLC22A1基因rs34059508位點等位基因及基因型頻率比較,差異有統(tǒng)計學意義(P<0.05);其中,新疆維吾爾族人群SLC22A1基因rs34059508位點等位基因A頻率低于高加索人群,差異有統(tǒng)計學意義(P<0.001,見表1)。
表1 不同種族人群SLC22A1基因rs34059508位點等位基因及基因型頻率比較〔n(%)〕
Table 1 Comparison of frequency of genotypes and alleles of rs34059508 sites of SLC22A1 gene of different racial populations
種族例數(shù)等位基因基因型GAGGGAAA亞洲人群178356(100.0)0178(100.0)00高加索人群200384(96.0)16(4.0)184(92.0)16(8.0)0非裔美國人群200400(100.0)0200(100.0)00新疆維吾爾族人群276551(99.8)1(0.2)275(99.6)1(0.4)0χ2值41.58542.083P值<0.001<0.001
注:亞洲人群、高加索人群、非裔美國人群SLC22A1基因rs34059508位點等位基因及基因型頻率數(shù)據(jù)來源于NCBI dbSNP數(shù)據(jù)庫
2.3 不同種族人群SLC22A1基因rs4646277位點等位基因及基因型頻率比較 亞洲人群、漢族人群、新疆維吾爾族人群SLC22A1基因rs4646277位點等位基因及基因型頻率比較,差異有統(tǒng)計學意義(P<0.05);其中,新疆維吾爾族人群SLC22A1基因rs4646277位點等位基因T頻率高于漢族人群,差異有統(tǒng)計學意義(P<0.017,見表2)。
表2 不同種族人群SLC22A1基因rs4646277位點等位基因及基因型頻率比較〔n(%)〕
Table 2 Comparison of frequency of genotypes and alleles of rs4646277 sites of SLC22A1 gene of different racial populations
種族例數(shù)等位基因基因型CTCCCTTT亞洲人群172340(98.8)4(1.2)168(97.7)4(2.3)0漢族人群170338(99.4)2(0.6)168(98.8)2(1.2)0新疆維吾爾族人群276536(97.1)16(2.9)260(94.2)16(5.8)0χ2值7.4627.600P值0.0240.022
注:亞洲人群、漢族人群SLC22A1基因rs4646277位點等位基因及基因型頻率數(shù)據(jù)來源于NCBI dbSNP數(shù)據(jù)庫
2.4 有無T2DM家族史對SLC22A1基因突變的影響 227例受試者具有T2DM家族史資料,SLC22A1基因突變率為76.6%(174/227)。19例有T2DM家族史者中12例(63.2%)發(fā)生SLC22A1基因突變,208例無T2DM家族史者SLC22A1基因突變率為77.9%(162/208),差異無統(tǒng)計學意義(χ2=1.367,P=0.242)。
性別、年齡、身高、體質(zhì)量等是決定藥物反應性的因素,而遺傳因素是決定藥物反應性的根本因素。藥物代謝酶、轉(zhuǎn)運體和受體等藥物作用靶點基因變異導致其功能改變,進一步使血藥濃度及藥物敏感性發(fā)生變化[12]。SHU等[13]在細胞和人體內(nèi)系統(tǒng)中研究了SLC22A1遺傳多態(tài)性對二甲雙胍藥物反應性的影響,發(fā)現(xiàn)在SLC22A1基因突變的HEK293細胞系中,轉(zhuǎn)染SLC22A1-S16F、SLC22A1-R61C、SLC22A1-S189L、SLC22A1-G220V、SLC22A1-G4015、SLC22A1-420del的細胞系在蛋白量表達相同的情況下,對二甲雙胍的轉(zhuǎn)運效能降低。因此,發(fā)現(xiàn)新疆維吾爾族人群SLC22A1基因的常見突變類型,可為查明SLC22A1底物藥物代謝及藥效的個體差異提供信息。
本研究發(fā)現(xiàn)維吾爾族人群SLC22A1基因rs34059508位點等位基因G、A分布頻率分別為99.8%、0.2%,基因型GG、GA分布頻率為99.6%、0.4%,無AA基因型。在亞洲人群中未發(fā)現(xiàn)SLC22A1基因rs34059508位點GA基因型,而本研究新疆維吾爾族人群GA基因型頻率為0.4%,說明新疆維吾爾族人群基因多態(tài)性總體符合亞洲人群基因型,但分布規(guī)律也有自身特異性。本研究發(fā)現(xiàn)維吾爾族人群SLC22A1基因rs4646277位點等位基因C、T分布頻率分別為97.1%、2.9%,基因型CC、CT分布頻率為94.2%、5.8%,無TT基因型。本研究SLC22A1基因rs34059508、rs4646277位點基因頻率分布符合Hardy-Weinberg遺傳平衡,具有群體代表性,結合上述結論,說明新疆維吾爾族基因多態(tài)性總體符合亞洲人群基因型,但多態(tài)性分布規(guī)律也有自身特異性[14]。新疆維吾爾族SLC22A1基因突變率高,SLC22A1基因rs34059508、rs4646277位點等位基因頻率分布尚未見報道,本研究豐富了該基因在我國不同地區(qū)、不同種族人群中的分布情況,可為今后進一步的研究提供更詳細的資料。
T2DM是由遺傳因素和環(huán)境因素共同作用導致的復雜疾病,由于同一家族中的成員具有共同的行為和生活方式,所以家族史可作為研究遺傳因素與疾病關系的替代指標[15]。有研究表明,T2DM的遺傳度為(83.42±5.84)%,先證者單卵雙生后代患T2DM的一致率為50%,異卵者為37%;有家族史者患T2DM的風險是無家族史者的1.56~6.91倍[16-18]。
目前,僅少數(shù)T2DM的易患基因(如TCF7L2基因rs7903146位點)在歐洲白種人、墨西哥裔美國人、印度、西非、日本等種族人群得到驗證(OR為1.41~1.67)[19-20]。VELASCO MONDRAGON等[15]于2006年首次報道在冰島、丹麥、美國人群中TCF7L2基因變異(尤其是內(nèi)含子3、4中的rs7903146和rs12255372位點)與T2DM具有較強的相關性。不同種族的遺傳背景及其生存環(huán)境存在差異,在不同種族中印證已報道的疾病相關基因或位點對人類復雜疾病病理機制研究具有重要意義[21]。本研究未發(fā)現(xiàn)T2DM家族史對SLC22A1基因突變率存在影響,即有無T2DM家族史者基因突變率無差異。
綜上所述,本研究初步探討新疆維吾爾族男性SLC22A1基因突變,可為二甲雙胍臨床用藥的個體化差異提供依據(jù)。同時T2DM是多基因遺傳疾病,基因多態(tài)性可能與T2DM遺傳存在一定的關聯(lián),需擴大樣本研究基因突變位點與糖脂代謝、胰島B細胞功能和胰島素抵抗的關系,從而研究T2DM家族史是否增加SLC22A1基因或者其他基因的突變頻率。
作者貢獻:張莉進行文章的構思與設計、數(shù)據(jù)整理、統(tǒng)計學處理、撰寫論文;占瓊、周源、楊歡杰進行數(shù)據(jù)收集;趙軍進行研究的實施與可行性分析;李建光進行論文的修訂;王寧進行文章的構思與設計、研究的實施與可行性分析、質(zhì)量控制及審校。
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(本文編輯:吳立波)
Frequency Distribution of SLC22A1 Gene Polymorphism and Effects of Family History of Diabetes on Mutation in Xinjiang Uygur Population
ZHANGLi1,ZHANQiong2,ZHAOJun3,LIJian-guang4,ZHOUYuan1,YANGHuan-jie1,WANGNing5*
1.TheFirstAffiliatedHospitalofXinjiangMedicalUniversity,Urumqi830011,China
2.DepartmentofPostgraduateManagement,GraduateSchoolofXinjiangMedicalUniversity,Urumqi830011,China
3.DepartmentofPharmacy,theFirstAffiliatedHospitalofXinjiangMedicalUniversity,Urumqi830011,China
4.UniversityHospital,XinjiangMedicalUniversity,Urumqi830011,China
5.DepartmentoftheFirstInternalMedicineintheCadreWards,theFirstAffiliatedHospitalofXinjiangMedicalUniversity,Urumqi830011,China
Background Transport protein is a drug transporter that has attracted much attention in recent years.It is encoded by SLC22A1 gene.SLC22A1 gene has significant genetic polymorphism,and its multiple mutations have been found in many races.It is an important cause of metformin bioavailability differences in patients with type 2 diabetes mellitus (T2DM).Objective To study the frequency distribution of alleles and genotypes of rs34059508 and rs4646277 sites of SLC22A1 gene in Xinjiang Uygur young men,explorer the effects of family history of diabetes on mutation,and provide theoretical basis for individualized treatment of metformin with gene orientation of T2DM patients.Methods From September 2014 to September 2015,276 Uygur male healthy volunteers in Xinjiang were recruited.The 5 ml peripheral blood was collected,and DNA were extracted.The alleles and genotypes of rs34059508 and rs4646277 sites of SLC22A1 gene and nutation among the subjects were analyzed by Snapshot technology platform.Results The frequency distribution of the alleles of rs34059508 and rs4646277 sites of SLC22A1 gene was consistent with the genetic equilibrium of Hardy-Weinberg,which presents group representativeness (χ2=0.009,P=0.976;χ2=0.246,P=0.620).There were significant differences in the frequency of alleles and genotypes of rs34059508 sites of SLC22A1 gene in the Asian population,Caucasian population,African American population,Xinjiang Uygur population (P<0.05);the frequency of allele A of rs34059508 sites of SLC22A1 gene in the Xinjiang Uygur population was lower than that of the Caucasian population(P<0.001).There were significant differences in the frequency of alleles and genotypes of rs4646277 sites of SLC22A1 gene in the Asian population,Han population,Xinjiang Uygur population (P<0.05);the frequency of allele T of rs4646277 sites of SLC22A1 gene in the Xinjiang Uygur population was higher than that of the Han population (P<0.017).SLC22A1 gene mutation occurred in 12 cases(63.2%) among the 19 patients with family history of T2DM,the mutation rate of SLC22A1 gene was 77.9%(162/208) in the 208 cases without family history of T2DM,the difference was not statistically significant (χ2=1.367,P=0.242).Conclusion The mutation rate of rs34059508 and rs4646277 sites of SLC22A1 gene among Xinjiang Uygur men is 0.4% and 5.8% respectively.No effects of family history of T2DM are found on SLC22A1 gene mutation.
Diabetes mellitus,type 2;Biological availability;SLC22A1 gene;Polymorphism,single nucleotide;Uygur nationality
國家自然科學基金資助項目(81360510)
R 587.1
A
10.3969/j.issn.1007-9572.2017.05.013
2016-08-28;
2016-12-20)
1.830011新疆烏魯木齊市,新疆醫(yī)科大學第一附屬醫(yī)院
2.830011新疆烏魯木齊市,新疆醫(yī)科大學研究生學院研究生管理科
3.830011新疆烏魯木齊市,新疆醫(yī)科大學第一附屬醫(yī)院藥學部
4.830011新疆烏魯木齊市,新疆醫(yī)科大學校醫(yī)院
5.830011新疆烏魯木齊市,新疆醫(yī)科大學第一附屬醫(yī)院干部病房內(nèi)一科
*通信作者:王寧,主任醫(yī)師,副教授,碩士生導師;E-mall:wnlsdr@163.com
張莉,占瓊,趙軍,等.新疆維吾爾族人群SLC22A1基因多態(tài)性頻率分布及糖尿病家族史對其突變的影響研究[J].中國全科醫(yī)學,2017,20(5):569-573.[www.chinagp.net]
ZHANG L,ZHAN Q,ZHAO J,et al.Frequency distribution of SLC22A1 gene polymorphism and effects of family history of diabetes on mutation in Xinjiang Uygur population[J].Chinese General Practice,2017,20(5):569-573.
*Correspondingauthor:WANGNing,Chiefphysician,Associateprofessor,Mastersupervisor;E-mail:wnlsdr@163.com