From Genotype to Phenotype: Content and Activities of Cytochromes P450 2A6 in Human Liver In Vitro and Predicted In Vivo
From Genotype to Phenotype: Content and Activities of Cytochromes P450 2A6 in Human Liver In Vitro and Predicted In Vivo
复制标题
从基因型到表型：人肝脏中细胞色素 P450 2A6 的含量和活性体外及体内预测
DOI：
10.1124/jpet.119.263152
复制
发表时间：
2020-03-01
影响因子：
3.5
通讯作者：
Qiao, Hai-Ling
中科院分区：
文献类型：
--
作者：
Fang, Yan;Wang, Tong;Qiao, Hai-Ling
解开细胞色素P450 2A 6的遗传变异导致不同代谢表型的分子机制仍然是一个长期存在但重要的挑战。CYP 2A 6是一种参与多种临床药物代谢以及致癌亚硝胺代谢活化的酶。在此，测定了90份人肝脏样本的CYP 2A 6基因型和表型，如蛋白质含量[通过液相色谱-质谱法（MS）/MS]和代谢活性[Vmax，清除率（CL）]所示。我们确定了微粒体、肝组织和全肝水平上CYP 2A 6含量和活性的中位数、范围以及个体间和个体内变异，并基于每种CYP 2A 6基因型的CYP 2A 6介导的香豆素代谢，通过体外-体内外推法预测肝脏体内清除率。这些结果揭示了不同的CYP 2A 6基因型如何在蛋白质含量和酶活性方面产生不同的表型特征。相对Vmax、CL和蛋白质含量的个体内百分比变异系数（ICV）分别为41.0%（18.8%-125.1%）、28.5%（2.39%-133.5%）和27.8%（2.68%-88.0%）。高ICV意味着在不同水平上存在较大的个体内变异，有时是以基因型依赖的方式。基因型间分析显示，CYP 2A 6 *4等位基因对蛋白质含量和代谢活性的表型结果表现出最明显的影响。事实上，CYP 2A 6 *4基因型的CYP 2A 6蛋白含量降低可能解释了从分子到生物体水平的代谢活性降低。这些发现可能允许有用的预测CYP 2A 6介导的药物代谢的个体患者的基础上，雅阁的目标，实现个性化医疗。显著性声明我们提供了通过液相色谱-质谱法（MS）/MS测定的微粒体、肝组织和全肝水平的CYP 2A 6含量的中位数、范围以及个体间和个体内变异，以及基于各CYP 2A 6基因型的CYP 2A 6介导的香豆素代谢的体外和生物体水平的蛋白质、微粒体、肝组织和全肝水平的活性，从而使我们能够阐明不同的CYP 2A 6基因型如何产生不同的表型性状（蛋白质含量和酶活性），促进个性化药物的开发。
Unraveling the molecular mechanisms by which genetic variants of cytochrome P450 2A6 lead to different metabolic phenotypes remains a long-standing but important challenge. CYP2A6 is an enzyme involved in the metabolism of several clinical drugs as well as the metabolic activation of carcinogenic nitrosamines. Herein, CYP2A6 genotypes and phenotypes, as indicated by protein content [by liquid chromatography–mass spectrometry (MS)/MS] and metabolic activities [Vmax, clearance (CL)], were determined for 90 human liver samples. We determined the median, range, and interindividual and intraindividual variation of CYP2A6 content and activity at the microsomal, liver tissue, and whole liver level and predicted hepatic in vivo clearance by in vitro–in vivo extrapolation based on CYP2A6-mediated coumarin metabolism by each CYP2A6 genotype. These results reveal how different CYP2A6 genotypes yield different phenotypic traits in protein content and enzyme activity. For relative Vmax, CL, and protein content, the intraindividual percentage coefficients of variation (ICVs) were 41.0% (18.8%–125.1%), 28.5% (2.39%–133.5%), and 27.8% (2.68%–88.0%), respectively. The high ICVs implied large intraindividual variation at different levels, sometimes in a genotype-dependent manner. Intergenotype analysis revealed that the CYP2A6*4 allele demonstrated the most obvious effect on phenotypic outcomes, both in protein content and in metabolic activity. Indeed, decreased CYP2A6 protein content with the CYP2A6*4 genotype might explain the decreased metabolic activity from the molecular to the organismal level. These findings may allow useful predictions for CYP2A6-mediated drug metabolism on an individual patient basis in accord with the goal of achieving personalized medicine. SIGNIFICANCE STATEMENT We provide the median, range, and interindividual and intraindividual variation in CYP2A6 content at the microsomal, liver tissue, and whole liver level by liquid chromatography–mass spectrometry (MS)/MS as well as activities at the protein, microsomal, liver tissue, and whole liver level both in vitro and at the organismal level based on CYP2A6-mediated coumarin metabolism with each CYP2A6 genotype, thereby allowing us to elucidate how different CYP2A6 genotypes yield differing phenotypic traits (protein content and enzyme activity), facilitating the development of personalized medicine.