Adler S, Pellizzer C, Paparella M, Hartung T, Bremer S
ECVAM, Joint Research Centre, Institute for Health and Consumer Protection, Via E. Fermi 1, 21020 Ispra (VA), Italy.
Toxicol In Vitro. 2006 Apr;20(3):265-71. doi: 10.1016/j.tiv.2005.06.043. Epub 2005 Aug 19.
Dimethyl sulfoxide (DMSO) and ethanol are common organic solvents used for dissolving lipophilic substances for in vitro testing. However, DMSO is known to induce differentiation in embryonic stem (ES) and embryonic teratocarcinoma (EC) cells. In order to clarify if solvents like DMSO and ethanol have an influence on in vitro developmental toxicity test systems, the presented study has evaluated their effects on differentiation by using different test systems. ES and EC cells were transfected with a construct containing the mTert promoter combined with the green fluorescent protein gene (GFP). A down-regulation of mTert, a marker for undifferentiated cells, results in a lower expression of GFP, which could be measured by flow cytometry. Taking the specific characteristics of ES and EC cells into account this effect could be a hint for the interaction of DMSO with embryonic development. Additionally, the effects of the solvents ethanol and DMSO on Oct-4 expression, another marker for undifferentiated cells, were measured in wild-type ES cells. Both selected molecular markers demonstrated an induction of differentiation after exposure to DMSO; in wild-type ES cells at a concentration of 0.125% and in transgenic EC cells at a concentration of 0.25% DMSO. All other differences from controls, including those which attained a level of statistical significance, were minor or not dosage related in degree, or were not consistent over time and are, therefore, considered to be of little toxicological importance. In addition, a cytotoxicity test demonstrated that the solvents affected the employed molecular markers in non-cytotoxic concentrations. The ES cells were the most sensitive towards the cytotoxic effects of the solvent DMSO while the EC cells were more sensitive when treated with the solvent ethanol.
二甲基亚砜（DMSO）和乙醇是用于溶解亲脂性物质以进行体外测试的常见有机溶剂。然而，已知DMSO会诱导胚胎干细胞（ES）和胚胎性癌（EC）细胞分化。为了阐明像DMSO和乙醇这样的溶剂是否会对体外发育毒性测试系统产生影响，本研究通过使用不同的测试系统评估了它们对分化的影响。ES细胞和EC细胞用含有mTert启动子与绿色荧光蛋白基因（GFP）的构建体进行转染。未分化细胞的标志物mTert的下调会导致GFP表达降低，这可以通过流式细胞术进行测量。考虑到ES细胞和EC细胞的特定特征，这种效应可能暗示DMSO与胚胎发育之间的相互作用。此外，在野生型ES细胞中测量了溶剂乙醇和DMSO对未分化细胞的另一个标志物Oct-4表达的影响。两种选定的分子标志物在暴露于DMSO后均显示出分化诱导；在野生型ES细胞中，DMSO浓度为0.125%时出现这种情况，在转基因EC细胞中，DMSO浓度为0.25%时出现这种情况。与对照组的所有其他差异，包括那些达到统计学显著水平的差异，在程度上较小或与剂量无关，或者随时间不一致，因此被认为在毒理学上重要性不大。此外，细胞毒性测试表明，这些溶剂在非细胞毒性浓度下影响所使用的分子标志物。ES细胞对溶剂DMSO的细胞毒性作用最敏感，而EC细胞在用溶剂乙醇处理时更敏感。
