Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR 72079, USA.
Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR 72079, USA.
Mutat Res Genet Toxicol Environ Mutagen. 2024 Jul;897:503786. doi: 10.1016/j.mrgentox.2024.503786. Epub 2024 Jun 24.
The human in vitro organotypic air-liquid-interface (ALI) airway tissue model is structurally and functionally similar to the human large airway epithelium and, as a result, is being used increasingly for studying the toxicity of inhaled substances. Our previous research demonstrated that DNA damage and mutagenesis can be detected in human airway tissue models under conditions used to assess general and respiratory toxicity endpoints. Expanding upon our previous proof-of-principle study, human airway epithelial tissue models were treated with 6.25-100 µg/mL ethyl methanesulfonate (EMS) for 28 days, followed by a 28-day recovery period. Mutagenesis was evaluated by Duplex Sequencing (DS), and clonal expansion of bronchial-cancer-specific cancer-driver mutations (CDMs) was investigated by CarcSeq to determine if both mutation-based endpoints can be assessed in the same system. Additionally, DNA damage and tissue-specific responses were analyzed during the treatment and following the recovery period. EMS exposure led to time-dependent increases in mutagenesis over the 28-day treatment period, without expansion of clones containing CDMs; the mutation frequencies remained elevated following the recovery. EMS also produced an increase in DNA damage measured by the CometChip and MultiFlow assays and the elevated levels of DNA damage were reduced (but not eliminated) following the recovery period. Cytotoxicity and most tissue-function changes induced by EMS treatment recovered to control levels, the exception being reduced proliferating cell frequency. Our results indicate that general, respiratory-tissue-specific and genotoxicity endpoints increased with repeat EMS dosing; expansion of CDM clones, however, was not detected using this repeat treatment protocol. DISCLAIMER: This article reflects the views of its authors and does not necessarily reflect those of the U.S. Food and Drug Administration. Any mention of commercial products is for clarification only and is not intended as approval, endorsement, or recommendation.
人体体外器官型气液界面 (ALI) 气道组织模型在结构和功能上与人体大气道上皮相似，因此越来越多地用于研究吸入物质的毒性。我们之前的研究表明，在用于评估一般毒性和呼吸毒性终点的条件下，可以检测到人体气道组织模型中的 DNA 损伤和突变。在我们之前的原理验证研究的基础上，我们用 6.25-100μg/ml 的乙磺酸（EMS）处理人气道上皮组织模型 28 天，然后进行 28 天的恢复期。通过双链测序（DS）评估突变，通过 CarcSeq 评估支气管癌特异性癌症驱动突变（CDM）的克隆扩张，以确定是否可以在同一系统中评估基于突变的终点。此外，还在治疗期间和恢复期后分析了 DNA 损伤和组织特异性反应。EMS 暴露导致突变在 28 天的治疗期间呈时间依赖性增加，而不扩张含有 CDM 的克隆；在恢复期后，突变频率仍保持升高。EMS 还通过 CometChip 和 MultiFlow 测定导致 DNA 损伤增加，并且升高的 DNA 损伤水平在恢复期后降低（但未消除）。用 EMS 处理引起的细胞毒性和大多数组织功能变化恢复到对照水平，例外是增殖细胞频率降低。我们的结果表明，随着 EMS 的重复给药，一般毒性、呼吸道组织特异性和遗传毒性终点增加；然而，在用这种重复治疗方案时，没有检测到 CDM 克隆的扩张。免责声明：本文反映了其作者的观点，不一定反映美国食品和药物管理局的观点。任何对商业产品的提及仅用于澄清，并不表示批准、认可或推荐。
