Wang Peng, Zhang Yajiao, Chen Jia, Guo Lei, Xu Bin, Wang Lili, Xu Hua, Xie Jianwei
†State Key Laboratory of Toxicology and Medical Countermeasures, and Laboratory of Toxicant Analysis, Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, 27 Taiping Road, Haidian District, 100850, Beijing, China.
‡State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, 27 Taiping Road, Haidian District, 100850, Beijing, China.
Chem Res Toxicol. 2015 Jun 15;28(6):1224-33. doi: 10.1021/acs.chemrestox.5b00055. Epub 2015 May 20.
Sulfur mustard (SM) is a powerful alkylating vesicant that can rapidly penetrate skin, ocular, and lung bronchus mucous membranes and react with numerous nucleophiles in vivo. Although the lesion mechanisms of SM remain unclear, DNA damage is believed to be the most crucial factor in initiating SM-induced toxicity. Four major DNA adducts were identified for retrospective detection and DNA lesion evaluation, namely, N(7)-[2-[(2-hydroxyethyl)thio]-ethyl]guanine (N(7)-HETEG), bis(2-ethyl-N(7)-guanine)thioether (Bis-G), N(3)-(2-hydroxyethylthioethyl)-2'-adenine (N(3)-HETEA), and O(6)-[2-[(2-hydroxyethyl)thio]-ethyl]guanine (O(6)-HETEG). Because of previous observations that the levels of SM-DNA adducts were relatively higher in adipose-rich organs, such as the brain, we focused on the in vitro and in vivo fates of the DNA adducts in exposed adipocytes. A UPLC-MS/MS method developed in our laboratory was used to profile the N(7)-HETEG, Bis-G, and N(3)-HETEA levels in human mature adipocytes (HA-s) that had differentiated from human subcutaneous preadipocytes (HPA-s). This method was also used to profile three other cell lines related to the targeting of major tissues, including human keratinocytes (HaCaT), human hepatocytes (L-02), and human lung fibroblasts (HLF). Long-lasting adduct persistence and a high proportion of Bis-G were found in exposed adipocytes in vitro. The survival properties of exposed adipocytes were also tested. At the same time, the fate of SM-DNA adducts in vivo was characterized using a rat model exposed to 1 and 10 mg/kg doses of SM. The level of DNA adducts in the exposed adipose tissue (AT) was much lower than those in other organs studied in our previous work. The adduct persistence behavior was observed in AT with an extremely high proportion of Bis-G, which was higher than N(7)-HETEG. In light of these results, we suggest that an adipose-rich environment may promote the formation of Bis-G and that adipocyte-specific DNA repair mechanisms may result in adduct persistence and the survival of adipocytes after SM exposure. These conclusions should be further investigated.
硫芥（SM）是一种强大的烷基化糜烂剂，可迅速穿透皮肤、眼部和肺支气管黏膜，并在体内与众多亲核试剂发生反应。尽管硫芥的损伤机制尚不清楚，但DNA损伤被认为是引发硫芥诱导毒性的最关键因素。已鉴定出四种主要的DNA加合物用于回顾性检测和DNA损伤评估，即N(7)-[2-[(2-羟乙基)硫代]乙基]鸟嘌呤（N(7)-HETEG）、双(2-乙基-N(7)-鸟嘌呤)硫醚（Bis-G）、N(3)-(2-羟乙硫基乙基)-2'-腺嘌呤（N(3)-HETEA）和O(6)-[2-[(2-羟乙基)硫代]乙基]鸟嘌呤（O(6)-HETEG）。由于之前观察到硫芥-DNA加合物在富含脂肪的器官（如大脑）中的水平相对较高，我们重点研究了暴露的脂肪细胞中DNA加合物的体外和体内命运。我们实验室开发的一种超高效液相色谱-串联质谱法（UPLC-MS/MS）用于分析从人皮下前脂肪细胞（HPA-s）分化而来的人成熟脂肪细胞（HA-s）中N(7)-HETEG、Bis-G和N(3)-HETEA的水平。该方法还用于分析与主要组织靶向相关的其他三种细胞系，包括人角质形成细胞（HaCaT）、人肝细胞（L-02）和人肺成纤维细胞（HLF）。在体外暴露的脂肪细胞中发现了加合物的长期持续存在以及高比例的Bis-G。还测试了暴露脂肪细胞的存活特性。同时，使用暴露于1和10 mg/kg剂量硫芥的大鼠模型来表征硫芥-DNA加合物在体内的命运。暴露的脂肪组织（AT）中DNA加合物的水平远低于我们之前工作中研究的其他器官。在AT中观察到加合物的持续存在行为，其中Bis-G的比例极高，高于N(7)-HETEG。鉴于这些结果，我们认为富含脂肪的环境可能促进Bis-G的形成，并且脂肪细胞特异性DNA修复机制可能导致加合物的持续存在以及硫芥暴露后脂肪细胞的存活。这些结论应进一步研究。
