UGT1A9C-2152T和UGT2B7G211T突变在中国汉族人群中的分布

目的建立Touch-down PCR/RFLP的方法检测UGT1A9 C-2152T突变,建立PCR/RFLP的方法检测UGT2B7 G211T突变,确定其在中国汉族人群中的突变频率.方法采用Touch-down PCR/RFLP方法,对100名无亲缘关系的汉族男性志愿者进行UGT1A9 C-2152T的基因分型.采用PCR/RFLP方法,对363名无亲缘关系的汉族志愿者(其中男性263名、女性100名)进行UGT2B7 G211T的基因分型.结果在100名中国汉族男性受试者中,末发现UGT1A9 C-2152T的突变,与亚洲人通过测序报道的结果基本一致.在363名汉族受试者中,UGT2B7 G211T突变发生频率为 0.158,与日本人通过测序报道的结果基本一致.中国男性和女性的等位基因频率分别为 0.128 和 0.110,男性的突变频率比女性高(χ2=6.784, P=0.034).结论用PCR/RFLP的方法对UGT2B7 G211T突变分型的方法简便、快速、重复性好,可用于大样本人群的基因检测.UGT2B7 G211T突变在中国汉族人中发生频率较高.     

焦磷酸测序技术检测UGT1A3和UGT2B7在中国汉族人群中的基因多态性

目的建立焦磷酸测序技术(pyrosequencing)研究二相代谢酶UGT1A3和UGT2B7基因多态性在中国汉族人群中的分布。方法应用带生物素标记扩增引物并经PCR扩增和Beads分离,制备UGT1A3和UGT2B7焦磷酸测序单倍摸板。在PYroMarkID焦磷酸测序上进行焦磷酸测序,检测233血样的DNA标本的17个SNP位点,以确定血样DNA标本的的基因型。结果 233例血样的DNA标本中,UGT1A3等位基因有9种表型,分别为UGT1A3*1*1、UGT1A3*1*2、UGT1A3*1*3、UGT1A3*1*4、UGT1A3*1*5、UGT1A3*2*3、UGT1A3*2*4、UGT1A3*3*3和UGT1A3*3*5。UGT2B7-1和UGT2B7-2各有3种基因型,分别为G/G型、G/T型、T/T和C/C型、C/T型、T/T型。结论我国汉族人群中UGT1A3和UGT2B7基因突变较高。     

UGT1A6、UGT1A9基因多态性对汉族癫痫患者丙戊酸血药浓度的影响

目的:考察尿苷二磷酸葡萄糖醛酸转移酶(UGT)1A6和1A9基因多态性对汉族癫痫患者丙戊酸血药浓度的影响。方法:选取2014年1月—2015年4月于我院门诊就诊的汉族癫痫患者107例,均使用丙戊酸单药治疗,治疗时间为3个月~6年。采用酶放大免疫法测定患者体内丙戊酸稳态血药浓度,采用基质辅助激光解吸电离飞行时间质谱法检测其UGT1A6(rs2070959、rs6759892)和UGT1A9(rs13418420、rs2741045、rs2741049、rs6731242、rs72551330)基因型,并考察基因多态性与丙戊酸标准化血药浓度(CDR)的相关性。结果:未检出UGT1A9 rs72551330突变型,其余6个位点基因型频率均符合Hardy-Weinberg平衡(P>0.05)。UGT1A6 rs2070959、rs6759892突变基因携带(AG+GG或TG+GG型)者丙戊酸CDR值显著低于其野生纯合子携带(AA或TT型)者,差异均有统计学意义(P<0.05);而携带UGT1A9 rs13418420、rs2741045、rs2741049和rs6731242野生纯合子和突变基因的患者丙戊酸CDR值比较,差异均无统计学意义(P>0.05)。结论:汉族癫痫患者UGT1A6 rs2070959、rs6759892基因多态性与丙戊酸血药浓度有关,且UGT1A6 rs2070959、rs6759892突变基因携带者可能需要更高的丙戊酸剂量。     

UGT2B7 C802T和G211T基因多态性对癫痫患者丙戊酸代谢的影响

目的:检测尿苷二磷酸葡糖醛酰转移酶UGT2B7 C802T和G211T等位基因在癫痫患者中的分布和突变频率,探讨UGT2B7 C802T和G211T基因型对癫痫患者丙戊酸代谢的影响。方法:直接化学发光法测定丙戊酸血药浓度,PCR-RFLP技术检测UGT2B7 C802T和G211T基因多态性,PCR扩增产物直接测序验证基因型检测方法的可靠性。结果:102例癫痫患者中UGT2B7 C802T位点野生型CC14例,杂合突变型和纯合突变型CT、TT分别为46例和42例;UGT2B7 G211T位点的野生型GG78例,突变型GT、TT分别为23例和1例;位点802CC野生基因型患者服用单位剂量(mg·kg^-1)后的血药浓度为(3.02±1.32) μg·kg·ml^-1·mg^-1,CT基因型患者为(2.11±1.26) μg·kg·ml^-1·mg^-1,TT基因型患者为(2.31±1.25) μg·kg·ml^-1·mg^-1,CT、TT患者血药浓度较CC患者明显偏低,差异有统计学意义。位点211GG基因型患者服用单位剂量(mg·kg^-1)引起的血药浓度为(2.28±1.32) μg·kg·ml^-1·mg^-1,GT基因型患者为(2.30±1.38) μg·kg·ml^-1·mg^-1,GG型与GT型患者间无统计学差异。结论:UGT2B7 C802T基因多态性与丙戊酸的血药浓度有显著相关性,UGT2B7 G211T位点基因多态性与丙戊酸的血药浓度无显著相关性。临床上个体血药浓度的差异可能与UGT2B7 C802T基因多态性有关。     

Plasma level of AcMPAG in renal transplant recipients is related to the polymorphism of UGT2B7 211G 〉 T

AIM： To clarify whether Mycophenolic acid（MPA） or its metabolite AcMPAG can cause gastrointestinal disturbances, and to explore the effect of UGT2B7 SNP 211G 〉 T on the pharmacokinetic of AcMPAG. METHODS： Twenty-four renal transplant patients were enrolled in this study. Pharmacokinetic study was performed on day 14 after transplantation and symptoms were recorded on the same day. Multiple blood samples were collected before dosing and 0.5,1,1.5,2,4,6,8, 10 and 12 hours after morning dosing. Plasma concentrations of MPA, MPAG and AcMPAG were detected by HPLC. Genotype of UGT2B7 211G 〉 T was determined using PCR-RFLP method. RESULTS： No significant difference was observed between patients with and without side effects for AUC（0-12） of MPA and MPAG. The values of AUC（0-12）/dose of MPA, MPAG and AcMPAG were （39.7 ± 12.3）,[第一段]     

染料木素临床不良反应与CYP1A2、UGT1A7基因多态性研究

目的：探讨染料木素临床不良反应与CYP1A2、UGT1A7基因多态性的相关性。方法：114例健康志愿者随机分为试验组与对照组,试验组分别口服染料木素一个剂量50、100、200mg,每人服药1次,观察3d了解有无不良反应发生;用限制性片段长度多态性聚合酶链反应（RFLR-PCR）扩增基因片段并酶切电泳观察分析CYP1A2G2964A、C734A和UGT1A7Trp208Arg的多态性。结果：试验组及对照组的基因型及等位基因分布差异无统计学意义（P〉0.05）。试验组受试者根据有无不良反应的出现分为两组基因,CYP1A2G2964A基因：不良反应组14例受试者中有10例的基因型为G/A（占71.43%）,而无不良反应组41例受试者中有22例的基因型为G/G（占53.66%）;CYP1A2C734A基因：不良反应组13例受试者中有7例的基因型为C/A（占53.85%）,而无不良反应组32例受试者中有16例的基因型为A/A（占50.00%）;UGT1A7Trp208Arg基因：不良反应组15例受试者中有12例的基因型为Trp/Trp（占80.00%）,并且无不良反应组53例受试者中有32例的基因型也为Trp/Trp（占60.38%）。结论：染料木素不良反应组中CYP1A2G2964A基因以G/A型较高,CYP1A2C734A基因以G/G型较高;UGT1A7基因以Trp/Trp型较高。     

中国汉族人群hGSTA1基因C-69T多态性分析

目的　研究中国汉族人群中人谷胱甘肽S 转移酶(hGSTA1 )C-69T基因多态性的分布。方法1 4 0例血样本来自中国2 5个省份的汉族人口,用聚合酶链反应 限制性片段长度多态性方法检测hGSTA1 69位点的变异。结果　中国汉族人群GSTA1基因 69位点的野生型纯合子(CC)基因型的分布频率为75 .0 %,突变型纯合子(TT)基因型为0 .7%,杂合子(CT)基因型为2 4 .3 %;C及T两种等位基因的频率分别为87.1 %及1 2 .9%。结论中国汉族人群GSTA1基因呈多态性分布,其等位基因和基因型频率不同于其他种族     

葡萄糖醛酸转移酶UGT2B7-A268G基因多态性对癫痫儿童丙戊酸血药浓度的影响

目的：在丙戊酸（VPA）单药治疗的癫痫儿童中评估葡萄糖醛酸转移酶UGT2B7-A268G位点的遗传基因多态性对VPA血清浓度的影响。方法：本研究纳入200例癫痫患儿的丙戊酸血药浓度,测定VPA稳态血清浓度。对UGT2B7编码区的A268G采用聚合酶链反应（RPLF）扩增进行基因鉴定分型。根据UGT2B7基因多态性分析VPA血清药物浓度与基因多态性的关系。结果：携带变异UGT2B7-268G一个基因型或纯合基因患儿的VPA血清药物浓度显著高于携带AA基因的患儿。由于儿童个体差异较大,根据年龄、体质量调整VPA浓度后与基因多态性仍然显著关联（P<0.05）。UGT2B7-A268G的基因多态性与Hardy-Weinberg平衡一致（P>0.05）,其中UGT2B7-268A>G等位基因频率分布的是30.00%,而G突变的基因分布频率为70.00%。结论：癫痫患儿UGT2B7基因的A268G突变可能改变丙戊酸的药物代谢动力学过程,并且不受年龄、体质量等因素干扰。UGT2B7的基因多态性对儿童丙戊酸血药浓度产生影响,测定其基因型对于获得适当的丙戊酸稳态浓度和设定起始用药剂量有积极意义     

基于肝药酶CYP3A4、SULT2A1和UGT1A1探究京尼平的代谢解毒路径（英文）

栀子主要药效成分京尼平具有明显的肝毒性,限制了京尼平以及栀子的应用和开发。本文主要以人源性Hepa RG肝细胞为研究对象,基于肝脏主要代谢解毒酶CYP3A4、SULT2A1和UGT1A1探究介导京尼平代谢解毒的具体路径。结果表明, CYP3A4、SULT2A1和UGT1A1协同介导了京尼平于肝脏的代谢解毒,且CYP3A4是起决定因素的限速酶;其最主要代谢解毒路径为:CYP3A4-SULT2A1/UGT1A1,即:京尼平进入肝细胞后,首先经CYP3A4代谢为毒性减轻的I相代谢产物,再经II相代谢酶SULT2A21和UGT1A1代谢为毒性进一步减轻的代谢产物。本研究的结果初步阐明了京尼平的肝代谢解毒路径,为今后京尼平及栀子的合理使用及研发提供了依据,也为将来京尼平以及中药栀子和含栀子的中药组方配伍解毒的研究奠定了基础。     

Glucuronidation of 1'-hydroxyestragole (1'-HE) by human UDP-glucuronosyltransferases UGT2B7 and UGT1A9.

Estragole (4-allyl-1-methoxybenzene) is a naturally occurring food flavoring agent found in basil, fennel, bay leaves, and other spices. Estragole and its metabolite, 1'-hydroxyestragole (1'-HE), are hepatocarcinogens in rodent models. Recent studies from our laboratory have shown that glucuronidation of 1'-HE is a major detoxification pathway for estragole and 1'-HE, accounting for as much as 30% of urinary metabolites of estragole in rodents. Therefore, this study was designed to investigate the glucuronidation of 1'-HE in human liver microsomes in vitro and identify the specific uridine diphosphate glucuronosyltransferase (UGT) isoforms responsible for 1'-HE glucuronidation. The formation of the glucuronide of 1'-HE (1'-HEG) followed atypical kinetics, and the data best fit to a Hill equation, resulting in apparent kinetic parameters of Km = 1.45 mM, Vmax = 164.5 pmoles/min/mg protein, and n = 1.4. There was a significant intersubject variation in 1'-HE glucuronidation in 27 human liver samples, with a CV of 42%. A screen of cDNA expressed UGT isoforms indicated that UGT2B7 (83.94 +/- 0.188 pmols/min/mg), UGT1A9 (51.36 +/- 0.72 pmoles/min/mg), and UGT2B15 (8.18 +/- 0.037 pmoles/min/mg) were responsible for 1'-HEG formation. Glucuronidation of 1'-HE was not detected in cells expressing UGT1A1, UGT1A3, UGT1A4, UGT1A6, UGT1A7, UGT1A8, and UGT1A10. 1'-HE glucuronidation in 27 individual human liver samples significantly (p < 0.05) correlated with the glucuronidation of other UGT2B7 substrates (morphine and ibuprofen). These results imply that concomitant chronic intake of therapeutic drugs and dietary components that are UGT2B7 and/or UGT1A9 substrates may interfere with estragole metabolism. Our results also have toxicogenetic significance, as UGT2B7 is polymorphic and could potentially result in genetic differences in glucuronidation of 1'-HE and, hence, toxicity of estragole.     

Limited influence of UGT1A1*28 and no effect of UGT2B7*2 polymorphisms on UGT1A1 or UGT2B7 activities and protein expression in human liver microsomes

AIMS: UGT1A1 and UGT2B7 are enzymes that commonly contribute to drug glucuronidation. Since genetic factors have been suggested to contribute to variability in activities and expression levels of these enzymes, a quantitative assessment of the influence of the major genotypes (UGT1A1*28 or UGT2B7*2) on enzyme activities was conducted. METHODS: Using a bank of microsomal samples from 59 human livers, the effect of UGT1A1*28 or UGT2B7*2 polymorphisms were investigated on rates of estradiol 3-glucuronidation (a marker of UGT1A1 enzyme activity) or zidovudine glucuronidation (a marker of UGT2B7 enzyme activity) and levels of immunoreactive protein for each enzyme. Glucuronidation rates for both enzymes were measured at K(m)/S(50) and 10 times K(m)/S(50) concentrations. RESULTS: UGT1A1 and UGT2B7 enzyme activities varied up to 16-fold and sixfold, respectively. Rates at K(m)/S(50) concentration closely correlated with rates at 10 times K(m)/S(50) concentration for both enzymes (but not at 1/10th K(m) for UGT2B7). Enzyme activities correlated with relative levels of immunoreactive protein for UGT1A1 and UGT2B7. Furthermore, rates of zidovudine glucuronidation correlated well with rates of glucuronidation of the UGT2B7 substrate gemcabene, but did not correlate with UGT1A1 enzyme activities. For the UGT1A1*28 polymorphism, consistent with levels of UGT1A1 immunoreactive protein, mean UGT1A1 activity was 2.5- and 3.2-fold lower for TA(6)/TA(7) (P < 0.05) and TA(7)/TA(7) (P < 0.001) genotypes in comparison with the TA(6)/TA(6) genotype. CONCLUSIONS: Relative to the observed 16-fold variability in UGT1A1 activity, these data indicate only a partial (approximately 40%) contribution of the UGT1A1*28 polymorphism to variability of interindividual differences in UGT1A1 enzyme activity. For the UGT2B7*2 polymorphism, genotype had no influence on immunoreactive UGT2B7 protein or the rate of 3'-azido-3'-deoxythymidine glucuronidation.     

Contribution of UDP-glucuronosyltransferases 1A9 and 2B7 to the glucuronidation of indomethacin in the human liver

Objective We characterized the kinetics of indomethacin glucuronidation by recombinant UDP-glucuronosyltransferase (UGT) isozymes and human liver microsomes (HLM) and identified the human UGT isozymes involved. Methods Indomethacin glucuronidation was investigated using HLM and recombinant human UGT isozymes. Human UGTs involved in indomethacin glucuronidation were assessed in kinetic studies, chemical inhibition studies, and correlation studies. Results Among the UGT isozymes investigated, UGT1A1, 1A3, 1A9, and 2B7 showed glucuronidation activity for indomethacin, with UGT1A9 possessing the highest activity, followed by UGT2B7. Glucuronidation of indomethacin by recombinant UGT1A9 and 2B7 showed substrate inhibition kinetics with K _m values of 35 and 32 μM, respectively. The glucuronidation of indomethacin was significantly correlated with morphine 3OH-glucuronidation (r = 0.69, p < 0.05) and 3′-azido-3′-deoxythymidine glucuronidation (r = 0.82, p < 0.05), a reaction mainly catalyzed by UGT2B7. Propofol inhibited indomethacin glucuronidation in HLM with an IC₅₀ value of 248 μM, which is between the IC₅₀ value in recombinant UGT1A9 (106 μM) and UGT2B7 (> 400 μM). Conclusions These findings suggest that UGT2B7 plays a predominant role in indomethacin glucuronidation in the human liver and that UGT1A9 is partially involved.     

Influence of UGT1A8 and UGT2B7 genetic polymorphisms on mycophenolic acid pharmacokinetics in Japanese renal transplant recipients

Objective UGT1A8 and UGT2B7 are important uridine diphosphate-glucuronosyltransferase isoforms for the glucuronidation of mycophenolic acid (MPA). The aim of this investigation was to elucidate MPA pharmacokinetics in UGT1A8 and UGT2B7 genotypes in Japanese renal transplant recipients. Methods Seventy-two recipients received repeated doses of mycophenolate mofetil and tacrolimus. On day 28 after renal transplantation, plasma MPA concentrations were measured for the next 24 h using high-performance liquid chromatography. UGT1A8*2 (A¹⁷³G) and UGT2B7*2 (Y²⁶⁸) were detected using a PCR-RFLP-based procedure. Results There were no significant differences in daytime and nighttime pharmacokinetics of MPA between UGT1A8 or UGT2B7 genotypes. The mean daytime dose-adjusted AUC_0–12 of MPA in UGT1A8*1/*1, *1/*2 and *2/*2 were 2.47, 2.33 and 2.57 ng·h/ml/mg/kg (P = 0.7711), and the mean nighttime AUC_0–12 were 2.15, 2.00 and 2.08 ng·h/ml/mg/kg (P = 0.4656). The mean daytime and nighttime dose-adjusted AUC_0–12 of MPA in UGT2B7*1/*1, *1/*2 and *2/*2 were 2.61, 2.24 and 2.03 ng·h/ml/mg/kg and 2.18, 1.94, and 1.45 ng·h/ml/mg/kg, respectively (P = 0.3475 and 0.2575). The mean nighttime C_max, t_max, and AUC_6–12/AUC_0–12 ratio (enterohepatic circulation and recirculation ratio) of MPA in all UGT1A8 and UGT2B7 genotypes were lower, longer, and higher, respectively, than the daytime values. Conclusions Both UGT1A8 and UGT2B7 allelic variants seem not to affect Japanese interindividual variability for plasma MPA concentration. Regardless of UGT1A8 and UGT2B7 genetic polymorphisms, the absorption of MPA through enterohepatic recirculation is higher at night.     

Glucuronidation of flavonoids by recombinant UGT1A3 and UGT1A9

Flavonoids are highlighted for their potential roles in the prevention of oxidative stress-associated diseases. Their metabolisms in vivo, such as glucuronidation, are the key points to determine their health beneficial properties. In this paper, we tested the glucuronidation of nineteen flavonoids by both recombinant human UGT1A3 and UGT1A9. Eleven compounds could be catalyzed by both enzymes. In general, both enzymes showed moderate to high catalyzing activity to most flavonoid aglycones, while the catalyzing efficiency changed with structures. Each flavonoid produced more than one monoglucuronide with no diglucuronide detected by liquid chromatography-mass spectrometry (LC-MS). Enzymatic kinetic analysis indicated that the catalyzing efficiency (Vmax/Km) of UGT1A9 was higher than that of UGT1A3, suggesting its important role in flavonoid glucuronidation. Both human UGT1A3 and UGT1A9 preferred flavonoid aglycone to flavonoid glycoside, and their metabolism to arabinoside was stronger than to other glycosides. Of the flavonoids studied, it is the first time to report isorhamnetin, morin, silybin, kaempferol, daidzein, quercetin-3',4'-OCHO-, quercetin xylopyranoside and avicularin as substrates of UGT1A3. Apigenin, morin, daidzein, quercetin-3',4'-OCHO-, quercetin xylopyranoside and avicularin were the newly reported substrates of UGT1A9.     

Structure-metabolism relationships for the glucuronidation of flavonoids by UGT1A3 and UGT1A9

Objectives This study tries to find structure–metabolism relationships between flavonoids and human UGT1A3 and UGT1A9. Methods The glucuronidation of flavonoids was studied with recombinant UGT1A3 and UGT1A9, and the glucuronidation activity was determined by HPLC. Key findings Of the flavonoids studied, it was shown for the first time that baicalein, quercetin‐3‐OCH₂OCH₃, quercetin‐4′‐CH₃, quercetin‐3′‐OCH₃ and quercetin‐3′‐Br are substrates of UGT1A3. Wogonin, baicalein, quercetin‐4′‐Cl, quercetin‐3‐OCH₂OCH₃, quercetin‐3‐O‐arabinoside, quercetin‐4′‐CH₃, quercetin‐3′‐OCH₃ and quercetin‐3′‐Br are the newly reported substrates of UGT1A9. The preferred substrates for UGT1A3 and UGT1A9 contain the hydroxyl group at the C7‐position. The glycon and the position of the B ring have conspicuous influences on the glucuronidation activity, and other chemical structures of flavonoids have minor effects. Conclusions From the quantitative study, UGT1A9 in general has higher glucuronidation efficiency than UGT1A3.     

Amino terminal domains of human UDP-glucuronosyltransferases (UGT) 2B7 and 2B15 associated with substrate selectivity and autoactivation

Despite the important role of UDP-glucuronosyltransferases (UGT) in the metabolism of drugs, environmental chemicals and endogenous compounds, the structural features of these enzymes responsible for substrate binding and selectivity remain poorly understood. Since UGT2B7 and UGT2B15 exhibit distinct, but overlapping, substrate selectivities, UGT2B7-UGT2B15 chimeras were constructed here to identify substrate binding domains. A UGT2B7-15-7 chimera that incorporated amino acids 61-194 of UGT2B15 glucuronidated the UGT2B15 substrates testosterone and phenolphthalein, but not the UGT2B7 substrates zidovudine and 11alpha-hydroxyprogesterone. Derived apparent K(m) values for testosterone and phenolphthalein glucuronidation by UGT2B7-15((61-194))-7 were similar in magnitude to those determined for UGT2B15. Moreover, glucuronidation of the non-selective substrate 4-methylumbelliferone (4MU) by UGT2B7-15((61-194))-7 and UGT2B15 followed Michaelis-Menten and weak substrate inhibition kinetics, respectively, whereas 4MU glucuronidation by UGT2B7 exhibited sigmoidal kinetics characteristic of autoactivation. Six UGT2B7-15-7 chimeras that incorporated smaller domains of UGT2B15 were subsequently generated. Of these, UGT2B7-15((61-157))-7, UGT2B7-15((91-157))-7 and UGT2B7-15((61-91))-7 glucuronidated 4MU, but activity towards the other substrates investigated here was not detected. Like UGT2B7, the UGT2B7-15((61-157))-7, UGT2B7-15((91-157))-7 and UGT2B7-15((61-91))-7 chimeras exhibited sigmoidal 4MU glucuronidation kinetics. The sigmoidal 4MU kinetic data were well modelled using both the Hill equation and the expression for a two-site model that assumes the simultaneous binding of two substrate molecules at equivalent sites. It may be concluded that residues 61-194 of UGT2B15 are responsible for substrate binding and for conferring the unique substrate selectivity of UGT2B15, while residues 158-194 of UGT2B7 appear to facilitate the binding of multiple 4MU molecules within the active site.