The metabolite of organophosphate pesticide chlorpyrifos (CPF), 3,5,6-Trichloro-2-pyridinol (TCP), is persistent and mobile toxic substance in soil and water environments, exhibiting cytotoxic, genotoxic, and neurotoxic properties. However, little is known about its effects on the peripheral auditory system. Herein, we investigated the effects of TCP exposure on mouse postnatal day 3 (P3) cochlear culture and an auditory cell line HEI-OC1 to elucidate the underlying molecular mechanisms of ototoxicity. The damage of TCP to outer hair cells (OHC) and support cells (SC) was observed in a dose and time-dependent manner. OHC and SC were a significant loss from basal to apical turn of the cochlea under exposure over 800 μM TCP for 96 h. As TCP concentrations increased, cell viability was reduced whereas reactive oxygen species (ROS) generation, apoptotic cells, and the extent of DNA damage were increased, accordingly. TCP-induced phosphorylation of the p38 and JNK MAPK are the downstream effectors of ROS. The antioxidant agent, N-acetylcysteine (NAC), could reverse TCP-mediated intracellular ROS generation, inhibit the expressive level of cleaved-caspase 3 and block phosphorylation of p38/JNK. Overall, this is the first demonstration of TCP damaging to peripheral sensory HCs and SC in organotypic cultures from the postnatal cochlea. Data also showed that TCP exposure induced oxidase stress, cell apoptosis and DNA damage in the HEI-OC1 cells. These findings serve as an important reference for assessing the risk of TCP exposure.

有机磷农药毒死蜱(CPF)的代谢产物3,5,6-三氯-2-吡啶酚 (TCP) 是土壤和水环境中持久性、可移动的有毒物质，具有细胞毒性、基因毒性和神经毒性。然而，人们对其对周围听觉系统的影响知之甚少。在此，我们研究了 TCP 暴露对小鼠出生后第 3 天 (P3) 耳蜗培养物和听觉细胞系 HEI-OC1 的影响，以阐明耳毒性的潜在分子机制。TCP 对外毛细胞 (OHC) 和支持细胞 (SC) 的损伤以剂量和时间依赖性方式进行观察。在暴露于超过 800 μM TCP 96 小时的情况下，OHC 和 SC 是耳蜗从基部到顶端转的显着损失。随着 TCP 浓度的增加，细胞活力降低，而活性氧 (ROS) 生成、细胞凋亡和 DNA 损伤程度相应增加。TCP 诱导的 p38 和 JNK MAPK 磷酸化是 ROS 的下游效应器。抗氧化剂N-乙酰半胱氨酸 (NAC) 可以逆转 TCP 介导的细胞内 ROS 生成，抑制 cleaved-caspase 3 的表达水平并阻断 p38/JNK 的磷酸化。总体而言，这是首次证明 TCP 在产后耳蜗器官型培养物中损害外周感觉 HC 和 SC。数据还表明，TCP 暴露会诱导HEI-OC1 细胞氧化酶应激、细胞凋亡和 DNA 损伤。这些发现为评估TCP暴露风险提供了重要参考。