Armoo Albert, Diemer Tanner, Donkor Abigail, Fedorchik Jerrod, Van Slambrouck Severine, Willand-Charnley Rachel, Logue Brian A
Department of Chemistry & Biochemistry, South Dakota State University, Brookings, South Dakota 57007, United States.
Youngstown State University, Youngstown, Ohio 44555, United States.
ACS Bio Med Chem Au. 2023 Aug 9;3(5):448-460. doi: 10.1021/acsbiomedchemau.2c00087. eCollection 2023 Oct 18.
Sulfur mustard (SM), designated by the military as HD, is a highly toxic and dangerous vesicant that has been utilized as a chemical warfare agent since World War I. Despite SM's extensive history, an effective antidote does not exist. The effects of SM are predominantly based on its ability to alkylate important biomolecules. Also, with the potential for a fraction of SM to remain unreacted up to days after initial contact, a window of opportunity exists for direct neutralization of unreacted SM over the days following exposure. In this study, we evaluated the structure-activity relationship of multiple nucleophilic molecules to neutralize the toxic effects of 2-chloroethyl ethyl sulfide (CEES), a monofunctional analogue of SM, on human keratinocyte (HaCaT) cells. Cell viability, relative loss of extracellular matrix adhesions, and apoptosis caused by CEES were measured via MTT, cell-matrix adhesion (CMA), and apoptosis protein marker assays, respectively. A set of five two-carbon compounds with various functional groups served as a preliminary group of first-generation neutralizing agents to survey the correlation between mitigation of CEES's toxic effects and functional group nucleophilicity. Apart from thioacids, which produced additive toxicity, we generally observed the trend of increasing protection from cytotoxicity with increasing nucleophilicity. We extended this treatment strategy to second-generation agents which contained advantageous structural features identified from the first-generation molecules. Our results show that methimazole (MIZ), a currently FDA-approved drug used to treat hyperthyroidism, effectively reduced cytotoxicity, increased CMA, and decreased apoptosis resulting from CEES toxicity. MIZ selectively reacts with CEES to produce 2-(2-(ethylthio)ethylthio)-1-methyl-1-imidazole (EEMI) in media and cell lysate treatments resulting in the reduction of toxicity. Based on these results, future development of MIZ as an SM therapeutic may provide a viable approach to reduce both the immediate and long-term toxicity of SM and may also help mitigate slower developing SM toxicity due to residual intact SM.
硫芥（SM），军方代号为HD，是一种剧毒且危险的糜烂性毒剂，自第一次世界大战以来一直被用作化学战剂。尽管硫芥有着悠久的使用历史，但目前尚无有效的解毒剂。硫芥的作用主要基于其使重要生物分子烷基化的能力。此外，部分硫芥在初次接触后数天仍有可能未发生反应，因此在接触后的数天内存在直接中和未反应硫芥的机会窗口。在本研究中，我们评估了多种亲核分子的构效关系，以中和2-氯乙基乙硫醚（CEES，硫芥的单官能类似物）对人角质形成细胞（HaCaT细胞）的毒性作用。分别通过MTT法、细胞-基质黏附（CMA）测定法和凋亡蛋白标志物测定法，检测CEES导致的细胞活力、细胞外基质黏附相对丧失以及细胞凋亡情况。一组含有不同官能团的五个二碳化合物作为第一代中和剂的初步研究组，以探究减轻CEES毒性作用与官能团亲核性之间的相关性。除了产生相加毒性的硫代酸外，我们总体上观察到随着亲核性增加，细胞毒性保护作用增强的趋势。我们将这种治疗策略扩展到第二代试剂，这些第二代试剂包含从第一代分子中识别出的有利结构特征。我们的结果表明，甲巯咪唑（MIZ），一种目前美国食品药品监督管理局批准用于治疗甲状腺功能亢进的药物，能有效降低细胞毒性，增加CMA，并减少CEES毒性导致的细胞凋亡。在培养基和细胞裂解物处理中，MIZ与CEES选择性反应生成2-(2-(乙硫基)乙硫基)-1-甲基-1-咪唑（EEMI），从而降低毒性。基于这些结果，未来将MIZ开发为硫芥治疗药物可能为降低硫芥的即时和长期毒性提供一种可行的方法，也可能有助于减轻因残留完整硫芥导致的发展较慢的硫芥毒性。
