Charles River Laboratories Edinburgh Ltd, Elphinstone Research Centre, Tranent, East Lothian EH33 2NE, UK.
MatTek Life Sciences, Ashland, Massachusetts 01721, USA.
Toxicol Sci. 2023 Jul 28;194(2):178-190. doi: 10.1093/toxsci/kfad058.
In vivo models (mostly rodents) are currently accepted by regulatory authorities for assessing acute inhalation toxicity. Considerable efforts have been made in recent years to evaluate in vitro human airway epithelial models (HAEM) as replacements for in vivo testing. In the current work, an organotypic in vitro rat airway epithelial model (RAEM), rat EpiAirway, was developed and characterized to allow a direct comparison with the available HAEM, human EpiAirway, in order to address potential interspecies variability in responses to harmful agents. The rat and human models were evaluated in 2 independent laboratories with 14 reference chemicals, selected to cover a broad range of chemical structures and reactive groups, as well as known acute animal and human toxicity responses, in 3 replicate rounds of experiments. Toxicity endpoints included changes in tissue viability (MTT assay), epithelial barrier integrity (TEER, transepithelial electrical resistance), and tissue morphology (histopathology). The newly developed rat EpiAirway model produced reproducible results across all replicate experiments in both testing laboratories. Furthermore, a high level of concordance was observed between the RAEM and HAEM toxicity responses (determined by IC25) in both laboratories, with R2=0.78 and 0.88 when analyzed by TEER; and R2=0.92 for both when analyzed by MTT. These results indicate that rat and human airway epithelial tissues respond similarly to acute exposures to chemicals. The new in vitro RAEM will help extrapolate to in vivo rat toxicity responses and support screening as part of a 3Rs program.
目前,监管机构普遍接受体内模型(主要是啮齿动物)来评估急性吸入毒性。近年来,人们为评估体外人呼吸道上皮模型(HAEM)作为体内测试的替代品付出了相当大的努力。在目前的工作中,开发并表征了一种器官型体外大鼠呼吸道上皮模型(RAEM),即大鼠 EpiAirway,以便与现有的 HAEM,即人 EpiAirway 进行直接比较,从而解决对有害剂的反应中潜在的种间变异性。这两种模型在两个独立的实验室中用 14 种参考化学物质进行了评估,这些化学物质选择覆盖了广泛的化学结构和反应基团,以及已知的急性动物和人类毒性反应,在 3 轮重复实验中进行。毒性终点包括组织活力变化(MTT 测定)、上皮屏障完整性(TEER,跨上皮电阻)和组织形态学(组织病理学)。在两个测试实验室的所有重复实验中,新开发的大鼠 EpiAirway 模型均产生了可重复的结果。此外,在两个实验室中,RAEM 和 HAEM 的毒性反应(通过 IC25 确定)之间观察到高度一致性,通过 TEER 分析时 R2=0.78 和 0.88;通过 MTT 分析时 R2=0.92。这些结果表明,大鼠和人呼吸道上皮组织对化学物质的急性暴露具有相似的反应。新的体外 RAEM 将有助于推断大鼠体内毒性反应,并支持作为 3R 计划一部分的筛选。