Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands.
Toxicol In Vitro. 2012 Sep;26(6):970-8. doi: 10.1016/j.tiv.2012.05.015. Epub 2012 Jun 7.
The embryonic stem cell test (ESTc), in which the effect of chemical compounds on cardiomyocyte differentiation is evaluated, is one of the most studied in vitro alternatives for developmental toxicity testing. Because the assay readout is restricted to a single endpoint of differentiation, compounds that affect alternative differentiation pathways might be overlooked. It has therefore been suggested that the predictive value of the EST may be improved by including alternative differentiation endpoints. The aim of the present study was to evaluate the effect of five teratogenic compounds as well as one non-teratogenic compound on the differentiation of murine embryonic stem cells into osteoblasts (ESTo) and to compare results with those in the classical ESTc. We established an ESTo assay which proved robust, stable and reproducible. In this study, we showed that the evaluated compounds affected osteoblast differentiation both at the level of calcium concentrations in the culture as well as on multiple gene expression. Furthermore, we showed that the effect on calcium concentrations appeared to be primarily mediated by a general apoptotic effect and not by a specific effect on differentiation. The compounds tested showed little difference in their potency in the ESTo as compared to the ESTc. Before a definitive statement can be made regarding the added value of including an osteoblast differentiation endpoint into the EST, more compounds need to be evaluated.
胚胎干细胞测试（ESTc）是研究最多的体外替代发育毒性测试方法之一，用于评估化合物对心肌细胞分化的影响。由于该测定的读数仅限于分化的单一终点，因此可能会忽略影响替代分化途径的化合物。因此，有人建议通过纳入替代分化终点来提高 EST 的预测价值。本研究旨在评估五种致畸化合物以及一种非致畸化合物对鼠胚胎干细胞向成骨细胞分化的影响（ESTo），并将结果与经典 ESTc 进行比较。我们建立了一个 ESTo 测定法，该方法被证明是稳健、稳定和可重复的。在这项研究中，我们表明，所评估的化合物在培养物中的钙浓度水平以及多个基因表达水平上均影响成骨细胞分化。此外，我们表明，对钙浓度的影响似乎主要是通过一般的凋亡作用介导的，而不是通过对分化的特异性作用介导的。与 ESTc 相比，在 ESTo 中，测试的化合物的效力差异很小。在确定将成骨细胞分化终点纳入 EST 的附加价值之前，需要对更多的化合物进行评估。
