Breath-borne volatile organic compounds (VOCs) have been increasingly studied as non-invasive biomarkers in both medical diagnosis and environmental health research. Recently, changes in breath-borne VOC fingerprints were demonstrated in rats and humans following pollutant exposures. In this study, the eukaryotic model Saccharomyces cerevisiae was used to study the release of cellular VOCs resulting from toxicant exposures (i.e., O₃, H₂O₂, and CO₂) and its underlying biological mechanism. Our results showed that different toxicant exposures caused the release of distinctive VOC profiles of yeast cells. The levels of ethyl acetate and ethyl n-propionate were altered in response to all the toxicants used in this study and could thus be targeted for future environmental toxicity monitoring. The RNA-seq results revealed significant changes in the metabolic or signaling pathways related to the ribosome, carbohydrate, and amino acid metabolisms after exposures. Notably, the shift from glycolysis to the pentose phosphate pathway of carbohydrate metabolism and the inhabitation of the aspartate pathway in the lysine synthesis was essential to the cellular antioxidation by providing reduced nicotinamide adenine dinucleotide phosphate (NADPH). The reprogrammed metabolisms could have resulted in the observed changes of VOCs released, e.g., the production of ethyl acetate for detoxification from yeast cells. This study provides further evidence that VOCs released from living organisms could be used to monitor and guard against toxic exposures while providing better mechanistic insights of the changes in breath-borne VOCs previously observed in rats and humans exposed to air toxicants.

中文翻译：

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受压活细胞中独特挥发性有机化合物的基因调控释放

呼吸传播的挥发性有机化合物 (VOC) 作为非侵入性生物标志物在医学诊断和环境健康研究中的研究越来越多。最近，在暴露于污染物后，大鼠和人类的呼吸传播的 VOC 指纹发生了变化。在这项研究中，真核模型酿酒酵母用于研究有毒物质暴露（即O ₃、H ₂ O ₂和CO ₂）引起的细胞VOCs的释放及其潜在的生物学机制。我们的结果表明，不同的毒物暴露导致酵母细胞释放出独特的 VOC 特征。乙酸乙酯和乙酸乙酯的含量-丙酸盐响应本研究中使用的所有毒物而改变，因此可以作为未来环境毒性监测的目标。RNA-seq 结果显示，暴露后与核糖体、碳水化合物和氨基酸代谢相关的代谢或信号通路发生了显着变化。值得注意的是，碳水化合物代谢从糖酵解到磷酸戊糖途径的转变以及赖氨酸合成中天冬氨酸途径的抑制对于通过提供还原的烟酰胺腺嘌呤二核苷酸磷酸 (NADPH) 来进行细胞抗氧化是必不可少的。重新编程的新陈代谢可能导致观察到释放的 VOC 的变化，例如，用于从酵母细胞中解毒的乙酸乙酯的产生。