Cisplatin-related ototoxicity is a critical side effect of chemotherapy and can lead to irreversible hearing loss. This study aimed to assess the potential effect of the DNA methyltransferase (DNMT) inhibitor RG108 on cisplatin-induced ototoxicity. Immunohistochemistry, apoptosis assay, and auditory brainstem response (ABR) were employed to determine the impacts of RG108 on cisplatin-induced injury in murine hair cells (HCs) and spiral ganglion neurons (SGNs). Rhodamine 123 and TMRM were utilized for mitochondrial membrane potential (MMP) assessment. Reactive oxygen species (ROS) amounts were evaluated by Cellrox green and Mitosox-red probes. Mitochondrial respiratory function evaluation was performed by determining oxygen consumption rates (OCRs). The results showed that RG108 can markedly reduce cisplatin induced damage in HCs and SGNs, and alleviate apoptotic rate by protecting mitochondrial function through preventing ROS accumulation. Furthermore, RG108 upregulated BCL-2 and downregulated APAF1, BAX, and BAD in HEI-OC1 cells, and triggered the PI3K/AKT pathway. Decreased expression of low-density lipoprotein receptor-related protein 1 (LRP1) and high methylation of the LRP1 promoter were observed after cisplatin treatment. RG108 treatment can increase LRP1 expression and decrease LRP1 promoter methylation. In conclusion, RG108 might represent a new potential agent for preventing hearing loss induced by cisplatin via activating the LRP1-PI3K/AKT pathway.

顺铂相关的耳毒性是化疗的严重副作用，可导致不可逆的听力损失。本研究旨在评估 DNA 甲基转移酶 (DNMT) 抑制剂 RG108 对顺铂诱导的耳毒性的潜在影响。免疫组织化学、细胞凋亡测定和听觉脑干反应 (ABR) 用于确定 RG108 对顺铂诱导的小鼠毛细胞 (HC) 和螺旋神经节神经元 (SGN) 损伤的影响。罗丹明 123 和 TMRM 用于线粒体膜电位 (MMP) 评估。通过 Cellrox green 和 Mitosox-red 探针评估活性氧 (ROS) 的量。通过确定耗氧率 (OCR) 进行线粒体呼吸功能评估。结果表明，RG108可以显着降低顺铂诱导的HCs和SGNs损伤，并通过防止 ROS 积累来保护线粒体功能，从而降低细胞凋亡率。此外，RG108 上调 HEI-OC1 细胞中的 BCL-2 并下调 APAF1、BAX 和 BAD，并触发 PI3K/AKT 通路。在顺铂治疗后观察到低密度脂蛋白受体相关蛋白 1 (LRP1) 的表达降低和 LRP1 启动子的高度甲基化。RG108 处理可增加 LRP1 表达并降低 LRP1 启动子甲基化。总之，RG108 可能代表一种新的潜在预防顺铂引起的听力损失的药物 在顺铂治疗后观察到低密度脂蛋白受体相关蛋白 1 (LRP1) 的表达降低和 LRP1 启动子的高度甲基化。RG108 处理可增加 LRP1 表达并降低 LRP1 启动子甲基化。总之，RG108 可能代表一种新的潜在预防顺铂引起的听力损失的药物 在顺铂治疗后观察到低密度脂蛋白受体相关蛋白 1 (LRP1) 的表达降低和 LRP1 启动子的高度甲基化。RG108 处理可增加 LRP1 表达并降低 LRP1 启动子甲基化。总之，RG108 可能代表一种新的潜在预防顺铂引起的听力损失的药物通过激活 LRP1-PI3K/AKT 通路。