在个体发育过程中,药物代谢酶(drug metabolizing enzyme,DME)的表达发生明显变化,根据个体发育特点分为3类:第一类酶在妊娠前3个月胎儿表达水平高,至妊娠末仍然保持高水平或略微下降,出生后1~2年表达水平则明显降低。第二类酶在妊娠期表达水平稳定,出生后仅发生微小变化。第三类酶在胎儿体内不表达或表达水平较低,出生后1~2年则明显升高。表观遗传调控是不涉及DNA序列改变的基因组修饰,主要包括DNA甲基化、组蛋白修饰及非编码RNAs调控。在肝脏发育过程中,表观遗传机制对DME发育表达发挥重要的调控作用。该综述全面回顾DME发育表达模式,揭示药物代谢与处置的潜在表观遗传调控机制,以明显提高儿童患者药物处置的预测能力,促进儿童患者合理、安全、有效用药。
Great changes in drug metabolizing enzyme (DME) expression occur in the fetus and child during development. Individual hepatic DME ontogeny can be categorized into one of three groups based on developmental trajectories.Some enzymes such as CYP3A7,are expressed at highest level in the fetus dur-ing the first trimester and either remain elevated or slightly de-crease during gestation,but are silenced or reduced to relatively low levels within one to two years after birth.SULT1 A1 is an ex-ample of the second group of DME.These enzymes are ex-pressed at relatively constant levels throughout gestation and into adulthood.CYP3A4 belongs to the third DME group .These en-zymes are expressed at negligible or low levels in the fetus.Sig-nificant increases in enzyme levels are exhibited within the first one to two years after birth.The epigenetic regulation refers to genomic modifications that do not involve changes in DNA se-quence and include DNA methylation,histone modifications, and non-coding RNAs.The epigenetic regulation mechanisms are responsible for the developmental expression of DME genes dur-ing liver maturation.This review will provide a summary of DME developmental expression profiles and reveal epigenetic mecha-nisms underlying variable drug metabolism and drug response. Thus,knowledge regarding DME ontogeny has permitted im-proved capability to predict drug disposition in pediatric pa-tients,which is crucial for improving drug dosing leading to opti-mal safety and efficacy in children.