Department of Pharmacology and Toxicology, The University of Alabama at Birmingham, Birmingham, AL 35294, United States.
Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan.
Toxicol Sci. 2024 Sep 1;201(1):85-102. doi: 10.1093/toxsci/kfae075.
Inhalation exposures to dihydroxyacetone (DHA) occur through spray tanning and e-cigarette aerosols. Several studies in skin models have demonstrated that millimolar doses of DHA are cytotoxic, yet the genotoxicity was unclear. We examined the genotoxicity of DHA in cell models relevant to inhalation exposures. Human bronchial epithelial cells BEAS-2B, lung carcinoma cells A549, cardiomyocyte Ac16, and hepatocellular carcinoma HepG3 were exposed to DHA, and low millimolar doses of DHA were cytotoxic. IC90 DHA doses induced cell cycle arrest in all cells except the Ac16. We examined DHA's genotoxicity using strand break markers, DNA adduct detection by Repair Assisted Damage Detection (RADD), metaphase spreads, and a forward mutation assay for mutagenesis. Similar to results for skin, DHA did not induce significant levels of strand breaks. However, RADD revealed DNA adducts were induced 24 h after DHA exposure, with BEAS-2B and Ac16 showing oxidative lesions and A549 and HepG3 showing crosslink-type lesions. Yet, only low levels of reactive oxygen species or advanced glycation end products were detected after DHA exposure. Metaphase spreads revealed significant increases in chromosomal aberrations in the BEAS-2B and HepG3 with corresponding changes in ploidy. Finally, we confirmed the mutagenesis observed using the supF reporter plasmid. DHA increased the mutation frequency, consistent with methylmethane sulfonate, a mutagen and clastogen. These data demonstrate DHA is a clastogen, inducing cell-specific genotoxicity and chromosomal instability. The specific genotoxicity measured in the BEAS-2B in this study suggests that inhalation exposures pose health risks to vapers, requiring further investigation.
二羟丙酮（DHA）通过喷雾晒黑和电子烟气溶胶吸入暴露。几项皮肤模型研究表明，毫摩尔剂量的 DHA 具有细胞毒性，但遗传毒性尚不清楚。我们在与吸入暴露相关的细胞模型中研究了 DHA 的遗传毒性。人支气管上皮细胞 BEAS-2B、肺癌细胞 A549、心肌细胞 Ac16 和肝癌细胞 HepG3 暴露于 DHA，低毫摩尔剂量的 DHA 具有细胞毒性。除了 Ac16 之外，所有细胞的 IC90DHA 剂量都诱导细胞周期停滞。我们使用链断裂标志物、修复辅助损伤检测 (RADD) 检测 DNA 加合物、中期分裂象和正向突变试验检测诱变来检查 DHA 的遗传毒性。与皮肤结果相似，DHA 没有诱导明显水平的链断裂。然而，RADD 显示 DHA 暴露 24 小时后诱导了 DNA 加合物，BEAS-2B 和 Ac16 显示氧化损伤，A549 和 HepG3 显示交联型损伤。然而，DHA 暴露后仅检测到低水平的活性氧或晚期糖基化终产物。中期分裂象显示 BEAS-2B 和 HepG3 中的染色体畸变显著增加，相应的倍性也发生变化。最后，我们使用 supF 报告质粒证实了观察到的诱变。DHA 增加了突变频率，与致突变剂和断裂剂甲磺酸甲酯一致。这些数据表明 DHA 是一种断裂剂，诱导细胞特异性遗传毒性和染色体不稳定性。本研究中 BEAS-2B 中测量的特定遗传毒性表明，吸入暴露对电子烟使用者构成健康风险，需要进一步调查。
