线粒体钙离子单向转运蛋白(MCU)介导的SQSTM1/p62乙酰化在顺铂耳毒性中的作用机制研究

顺铂作为治疗癌症最广泛使用的药物之一，可由于其耳毒性的并发症，造成了部分患者永久性听力丧失。我们前期研究发现，敲除巨噬细胞中线粒体钙离子单向转运蛋白(MCU)可增强其对李斯特菌的杀伤。此外有研究表明，在内耳毛细胞中，线粒体内钙离子过载对毛细胞有损伤作用。我们前期在HEI-OC1细胞系中应用顺铂，并阻断MCU后发现其细胞内自噬水平升高、凋亡水平下降，且自噬关键分子p62的乙酰化水平升高。基于上述研究，本项目首先在动物水平上应用MCU抑制剂，通过检测小鼠ABR、耳蜗毛细胞形态分布及自噬、凋亡因子变化，验证阻断MCU离子通道对顺铂耳毒性的作用机制；然后应用HEI-OC1细胞系行特异性小干扰RNA和慢病毒介导的基因转染技术，沉默MCU的表达，研究MCU在顺铂耳毒性中的详细机制，并明确乙酰化p62分子在其中的具体作用。本研究对于探索顺铂耳毒性治疗的新靶点、研发有效的抗顺铂耳毒性药物有着重要意义。

Cisplatin, as one of the most widely used drugs for the treatment of cancer, may cause permanent hearing loss in some patients due to its ototoxic complications. Our previous studies have found that knocking out the mitochondrial calcium uniporter (MCU) in macrophages can enhance its killing of L.monocytogenes. In addition, studies have shown that in inner ear hair cells, calcium ion overload in mitochondria has a damaging effect on hair cells. We used cisplatin in the HEI-OC1 cell line in the early stage, and after blocking the MCU, we found that the level of intracellular autophagy increased, the level of apoptosis decreased, and the level of acetylation of the key autophagy molecule p62 increased. Based on the above research, this project first applied MCU inhibitors at the animal level to verify the mechanism of blocking the MCU ion channel on the ototoxicity of cisplatin by detecting the changes in mouse ABR, cochlear hair cell morphology, autophagy and apoptosis factors ; Then use the HEI-OC1 cell line to perform specific small interfering RNA and lentivirus-mediated gene transfection technology to silence the expression of MCU, study the detailed mechanism of MCU in cisplatin ototoxicity, and clarify the acetylated p62 molecule in it the specific role. This study is of great significance for exploring new targets for the treatment of cisplatin ototoxicity and developing effective anti-cisplatin ototoxic drugs.