Summary： In adult liver, CYP3A4 plays an important role in the metabolism of a wide range of en- dogenous and exogenous compounds. To investigate whether there is a single nucleotide polymorphism （SNP） of CYP3A4 in...Summary： In adult liver, CYP3A4 plays an important role in the metabolism of a wide range of en- dogenous and exogenous compounds. To investigate whether there is a single nucleotide polymorphism （SNP） of CYP3A4 intron 2 in the liver and its effects on the mRNA expression and enzymatic activity of CYP3A4, genomic DNA was extracted from 96 liver tissue samples obtained from patients who had undergone liver surgery. An SNP of CYP3A4 intron 2 was identified by polymerase chain reaction （PCR）-single-strand confirmation polymorphism and DNA sequencing. The mRNA expression of CYP3A4 was determined by the fluorescence quantitative PCR technique. The enzymatic activity of CYP3A4 was measured using erythromycin and testosterone as probe substrates. Twelve patients were found to have the SNP/T4127G CYP3A4 within intron 2. The mRNA levels of CYP3A4 in wild-type and SNP/T4127G samples were 2.62±1.09 and 2.79±1.63, respectively （P〉0.05）. Erythromycin N-demethylase activity in wild-type and SNP/T4127G samples were 121.2±32.8 and 124.7±61.6 nmol·mg^-1min^-1, respectively （P〉0.05）. The activity of testosterone 613-hydroxylase was significantly different between wild-type （648±173 pmol·mg^-1·min^-1） and SNP/T4127G samples （540-4-196 pmol.mg-l-minl; P〈0.05）. In conclusion, the SNP/T4127G of CYP3A4 intron 2 exists in the liver. This SNP does not affect the mRNA expression of CYP3A4 but significantly decreases the hepatic micro- somal testosterone 613-hydroxylase activity of CYP3A4. Furthermore, this study indicates that the ap- propriate selection of probe substrates is very important in studying the relationship between the geno- type and phenotype of CYP3A4.展开更多
目的:建立和验证人孕烷X受体(human pregnant X receptor,hPXR)介导的CYP3A4、MDR1药物诱导剂的体外筛选体系,考察豆腐果苷对hPXR介导的CYP3A4、MDR1的转录调节作用。方法:利用构建的双荧光素酶报告基因系统,将表达载体和报告载体共转染...目的:建立和验证人孕烷X受体(human pregnant X receptor,hPXR)介导的CYP3A4、MDR1药物诱导剂的体外筛选体系,考察豆腐果苷对hPXR介导的CYP3A4、MDR1的转录调节作用。方法:利用构建的双荧光素酶报告基因系统,将表达载体和报告载体共转染HepG2细胞,以10μmol/L利福平为阳性对照,用不同浓度(0.004、0.04、0.4μmol/L)豆腐果苷处理48h后裂解细胞进行双荧光素酶活性检测。结果:不同浓度的豆腐果苷均不能通过激活hPXR来介导CYP3A4和MDR1表达上调,各浓度处理组的双荧光素酶比活性值与DMSO溶媒组差异无统计学意义(P>0.05)。结论:成功构建了hPXR介导的CYP3A4和MDR1药物诱导剂的体外筛选体系,并发现豆腐果苷不能通过激活hPXR介导CYP3A4和MDR1的表达上调。展开更多
基金supported by grants from the Scientific Research Foundation for Returned Scholars of the Ministry of Education of ChinaPre-research Foundation of Wuhan University,China(No.301270050)
文摘Summary： In adult liver, CYP3A4 plays an important role in the metabolism of a wide range of en- dogenous and exogenous compounds. To investigate whether there is a single nucleotide polymorphism （SNP） of CYP3A4 intron 2 in the liver and its effects on the mRNA expression and enzymatic activity of CYP3A4, genomic DNA was extracted from 96 liver tissue samples obtained from patients who had undergone liver surgery. An SNP of CYP3A4 intron 2 was identified by polymerase chain reaction （PCR）-single-strand confirmation polymorphism and DNA sequencing. The mRNA expression of CYP3A4 was determined by the fluorescence quantitative PCR technique. The enzymatic activity of CYP3A4 was measured using erythromycin and testosterone as probe substrates. Twelve patients were found to have the SNP/T4127G CYP3A4 within intron 2. The mRNA levels of CYP3A4 in wild-type and SNP/T4127G samples were 2.62±1.09 and 2.79±1.63, respectively （P〉0.05）. Erythromycin N-demethylase activity in wild-type and SNP/T4127G samples were 121.2±32.8 and 124.7±61.6 nmol·mg^-1min^-1, respectively （P〉0.05）. The activity of testosterone 613-hydroxylase was significantly different between wild-type （648±173 pmol·mg^-1·min^-1） and SNP/T4127G samples （540-4-196 pmol.mg-l-minl; P〈0.05）. In conclusion, the SNP/T4127G of CYP3A4 intron 2 exists in the liver. This SNP does not affect the mRNA expression of CYP3A4 but significantly decreases the hepatic micro- somal testosterone 613-hydroxylase activity of CYP3A4. Furthermore, this study indicates that the ap- propriate selection of probe substrates is very important in studying the relationship between the geno- type and phenotype of CYP3A4.
文摘目的:建立和验证人孕烷X受体(human pregnant X receptor,hPXR)介导的CYP3A4、MDR1药物诱导剂的体外筛选体系,考察豆腐果苷对hPXR介导的CYP3A4、MDR1的转录调节作用。方法:利用构建的双荧光素酶报告基因系统,将表达载体和报告载体共转染HepG2细胞,以10μmol/L利福平为阳性对照,用不同浓度(0.004、0.04、0.4μmol/L)豆腐果苷处理48h后裂解细胞进行双荧光素酶活性检测。结果:不同浓度的豆腐果苷均不能通过激活hPXR来介导CYP3A4和MDR1表达上调,各浓度处理组的双荧光素酶比活性值与DMSO溶媒组差异无统计学意义(P>0.05)。结论:成功构建了hPXR介导的CYP3A4和MDR1药物诱导剂的体外筛选体系,并发现豆腐果苷不能通过激活hPXR介导CYP3A4和MDR1的表达上调。
