Zhang Hai-Feng, Wang Huan-Huan, Gao Na, Wei Jun-Ying, Tian Xin, Zhao Yan, Fang Yan, Zhou Jun, Wen Qiang, Gao Jie, Zhang Yang-Jun, Qian Xiao-Hong, Qiao Hai-Ling
Institute of Clinical Pharmacology, Zhengzhou University, Zhengzhou, Henan, China (H.-F.Z., N.G., X.T., Y.F., J.Z., Q.W., J.G., H.-L.Q.); and State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing, China (H.-H.W., J.-Y.W., Y.-J.Z., Y.Z, X.-H.Q.).
Institute of Clinical Pharmacology, Zhengzhou University, Zhengzhou, Henan, China (H.-F.Z., N.G., X.T., Y.F., J.Z., Q.W., J.G., H.-L.Q.); and State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing, China (H.-H.W., J.-Y.W., Y.-J.Z., Y.Z, X.-H.Q.)
J Pharmacol Exp Ther. 2016 Jul;358(1):83-93. doi: 10.1124/jpet.116.233635. Epub 2016 May 9.
Due to a lack of physiologic cytochrome P450 (P450) isoform content, P450 activity is typically only determined at the microsomal level (per milligram of microsomal protein) and not at the isoform level (per picomole of P450 isoform), which could result in the misunderstanding of variations in P450 activity between individuals and further hinder development of personalized medicine. We found that there were large variations in protein content, mRNA levels, and intrinsic activities of the 10 P450s in 100 human liver samples, in which CYP2E1 and CYP2C9 showed the highest expression levels. P450 gene polymorphisms had different effects on activity at two levels: CYP3A53 and CYP2A69 alleles conferred increased activity at the isoform level but decreased activity at the microsomal level; CYP2C93 had no effect at the isoform level but decreased activity at the microsomal level. The different effects at each level stem from the different effects of each polymorphism on the resulting P450 protein. Individuals with CYP2A61/4, CYP2A61/9, CYP2C91/3, CYP2D6 100C>T TT, CYP2E1 7632T>A AA, CYP3A513, and CYP3A53*3 genotypes had significantly lower protein content, whereas CYP2D6 1661G>C mutants had a higher protein content. In conclusion, we first offered the physiologic data of 10 P450 isoform contents and found that some single nucleotide polymorphisms had obvious effects on P450 expression in human normal livers. The effects of gene polymorphisms on intrinsic P450 activity at the isoform level were quite different from those at the microsomal level, which might be due to changes in P450 protein content.
由于缺乏生理细胞色素P450（P450）同工型含量，P450活性通常仅在微粒体水平（每毫克微粒体蛋白）测定，而非在同工型水平（每皮摩尔P450同工型）测定，这可能导致对个体间P450活性差异的误解，并进一步阻碍个性化医疗的发展。我们发现，在100个人类肝脏样本中，10种P450的蛋白质含量、mRNA水平和内在活性存在很大差异，其中CYP2E1和CYP2C9表达水平最高。P450基因多态性在两个水平上对活性有不同影响：CYP3A53和CYP2A69等位基因在同工型水平上使活性增加，但在微粒体水平上使活性降低；CYP2C93在同工型水平上无影响，但在微粒体水平上使活性降低。每个水平的不同影响源于每种多态性对产生的P450蛋白的不同影响。具有CYP2A61/4、CYP2A61/9、CYP2C91/3、CYP2D6 100C>T TT、CYP2E1 7632T>A AA、CYP3A513和CYP3A53*3基因型的个体蛋白质含量显著较低，而CYP2D6 1661G>C突变体的蛋白质含量较高。总之，我们首次提供了10种P450同工型含量的生理数据，并发现一些单核苷酸多态性对人类正常肝脏中P450的表达有明显影响。基因多态性对同工型水平内在P450活性的影响与微粒体水平的影响有很大不同，这可能是由于P450蛋白含量的变化所致。
