Xenobiotica-metabolizing enzyme (XME) induction is a relevant biological/biochemical process vital to understanding the toxicological profile of xenobiotics. Early recognition of XME induction potential of compounds under development is therefore important, yet its determination by traditional XME activity measurements is time consuming and cost intensive. A proof-of-principle study was therefore designed due to the advent of faster and less cost-intensive methods for determination of enzyme protein and transcript levels to determine whether two such methods may substitute for traditional measurement of XME activity determinations. The results of the study show that determination of enzyme protein levels by peptide group-specific immunoaffinity enrichment/MS and/or determination of gene expression by NanoString nCounter may serve as substitutes for traditional evaluation methodology and/or as an early predictor of potential changes in liver enzymes. In this study, changes of XME activity by the known standard XME inducers phenobarbital, beta-naphthoflavone and Aroclor 1254 were demonstrated by these two methods. To investigate the applicability of these methods to demonstrate XME-inducing activity of an unknown, TS was also examined and found to be an XME inducer. More specifically, TS was found to be a phenobarbital-type inducer (likely mediated by CAR rather than PXR as nuclear receptor), but not due to Ah receptor-mediated or antioxidant response element-mediated beta-naphthoflavone-type induction. The results for TS were confirmed via enzymatic activity measurements. The results of the present study demonstrate the potential applicability of NanoString nCounter mRNA quantitation and peptide group-specific immunoaffinity enrichment/MS protein quantitation for predicting compounds under development to be inducers of liver XME activity.

异种抗生素代谢酶（XME）的诱导是相关的生物/生化过程，对于理解异种生物的毒理学特性至关重要。因此，尽早识别正在开发的化合物对XME的诱导潜力非常重要，但是通过传统XME活性测量来确定其潜力既费时又费钱。因此，由于出现了更快，成本更低的测定酶蛋白和转录水平的方法来确定两种这样的方法是否可以替代传统的XME活性测定方法，因此设计了原理验证研究。研究结果表明，通过肽基团特异性免疫亲和富集/ MS确定酶蛋白水平和/或通过NanoString nCounter确定基因表达可以替代传统评估方法和/或作为潜在的潜在变化预测指标。肝酶。在这项研究中，通过这两种方法证明了已知的标准XME诱导剂苯巴比妥，β-萘黄酮和Aroclor 1254对XME活性的改变。为了调查这些方法的适用性以证明未知物的XME诱导活性，还检查了TS，发现它是XME诱导剂。更具体地说，发现TS是苯巴比妥型诱导剂（可能由CAR介导，而不是PXR作为核受体介导），但不是由于Ah受体介导的或抗氧化剂反应元件介导的β-萘黄酮型诱导。通过酶活性测量证实了TS的结果。本研究的结果表明，NanoString nCounter mRNA定量和肽基团特异性免疫亲和富集/ MS蛋白定量的潜在适用性可预测正在开发中的化合物是肝XME活性的诱导剂。