Cheng Wei, Zhou Ren, Liang Fan, Wei Hongying, Feng Yan, Wang Yan
College of Public Health, School of Medicine, Shanghai Jiaotong University , Shanghai 200025, P.R. China.
Hongqiao International Institute of Medicine, School of Medicine, Shanghai Jiaotong University , Shanghai 200336, P.R. China.
Chem Res Toxicol. 2016 Sep 19;29(9):1519-33. doi: 10.1021/acs.chemrestox.6b00197. Epub 2016 Aug 10.
Gender effect is an inherent property of chemicals, characterized by variations caused by the chemical-biology interaction. It has widely existed, but the shortage of an appropriate model restricts the study on gender-specific effect. The embryonic stem cell test (EST) has been utilized as an alternative test for developmental toxicity. Despite its numerous improvements, mouse embryonic stem cells with an XX karyotype have not been used in the EST, which restricts the ability of the EST to identify gender-specific effects during high-throughput-screening (HTS) of chemicals to date. To address this, the embryonic stem cell (ESC) SP3 line with an XX karyotype was used to establish a "female" model as a complement to EST. Here, we proposed a "double-objects in unison" (DOU)-EST, which consisted of male ESC and female ESC; a seven-day EST protocol was utilized, and the gender-specific effect of chemicals was determined and discriminated; the replacement of myosin heavy chain (MHC) with myosin light chain (MLC) provided a suitable molecular biomarker in the DOU-EST. New linear discriminant functions were given in the purpose of distinguishing chemicals into three classes, namely, no gender-specific effect, male-susceptive, and female-susceptive. For 15 chemicals in the training set, the concordances of prediction result as no gender effect, male susceptive, and female susceptive were 86.67%, 86.67%, and 93.33%, respectively, the sensitivities were 66.67%, 83.33%, and 83.33%, respectively, and the specificities were 91.67%, 88.89%, and 100%, respectively; the total accuracy of DOU-EST was 86.67%. For three chemicals in the test set, one was incorrectively predicted. The possible reason for misclassification may due to the absence of hormone environment in vitro. Leave-one-out cross-validation (LOOCV) indicated a mean error rate of 18.34%. Taken together, these data suggested a good performance of the proposed DOU-EST. Emerging chemicals with undiscovered gender-specific effects are anticipated to be screened with the DOU-EST.
性别效应是化学物质的一种固有属性，其特征在于化学物质与生物相互作用所引起的差异。它广泛存在，但缺乏合适的模型限制了对性别特异性效应的研究。胚胎干细胞试验（EST）已被用作发育毒性的替代试验。尽管有诸多改进，但具有XX核型的小鼠胚胎干细胞尚未用于EST，这限制了EST在迄今为止化学物质高通量筛选（HTS）过程中识别性别特异性效应的能力。为了解决这一问题，使用具有XX核型的胚胎干细胞（ESC）SP3系建立了一个“雌性”模型作为EST的补充。在此，我们提出了一种“双对象协同”（DOU）-EST，它由雄性ESC和雌性ESC组成；采用了为期七天的EST方案，并确定和区分了化学物质的性别特异性效应；用肌球蛋白轻链（MLC）替代肌球蛋白重链（MHC）在DOU-EST中提供了一个合适的分子生物标志物。给出了新的线性判别函数，目的是将化学物质分为三类，即无性别特异性效应、雄性敏感和雌性敏感。对于训练集中的15种化学物质，预测结果为无性别效应、雄性敏感和雌性敏感的一致性分别为86.67%、86.67%和93.33%，灵敏度分别为66.67%、83.33%和83.33%，特异性分别为91.67%、88.89%和100%；DOU-EST的总准确率为86.67%。对于测试集中的三种化学物质，有一种预测错误。错误分类的可能原因可能是体外缺乏激素环境。留一法交叉验证（LOOCV）表明平均错误率为18.34%。综上所述，这些数据表明所提出的DOU-EST性能良好。预计将用DOU-EST筛选出具有未发现的性别特异性效应的新型化学物质。
