Atox1通过调控线粒体蛋白表达抵抗铜损伤的机制研究

铜是动物生长发育必需的微量营养元素之一，具有促生长和抗菌等作用，被广泛添加到畜禽日粮中促进生产。然而，持续添加超过生理范围的铜对动物造成毒害，其中绵羊最为敏感。摄入过量铜会引起细胞活性氧升高，生物大分子氧化，导致细胞损伤，引发病理反应。Atox1主要功能为转运铜离子，同时有抗氧化和转录调控功能，但其抵抗铜氧化损伤机制还不清楚。本申请前期发现，敲低Atox1的绵羊胰腺类器官对铜毒性敏感，细胞游离铜增加，线粒体功能失调。进一步研究发现，Atox1能调控线粒体功能基因表达，且与排铜密切相关，暗示Atox1通过调控线粒体蛋白表达促进游离铜外排抵抗氧化损伤。本项目拟通过绵羊活体和离体铜耐受实验、线粒体功能分析、转录组测序、CHIP-Seq、基因功能分析等手段，深入解析Atox1调控线粒体功能促进游离铜外排抵抗氧化损伤机制，为利用Atox1促进动物健康和生长，通过育种促进铜营养利用提供靶点和新策略。

Copper is one of the micronutrients necessary for the growth and development of livestock and poultry. It has been demonstrated that copper could promote individual growth and antibacterial, and is widely added to diets to promote animal production. However, different animals have different thresholds of copper tolerance. Among them, sheep are the most sensitive. Sustaining ingestion of copper beyond the appropriate range will cause the increase of reactive oxygen species, oxidation of biological macromolecules, resulting in cell damage and triggering pathological reactions. Atox1's main function is to transport copper ions to Golgi body, and it also has antioxidant and transcriptional regulation functions, but its mechanism of resisting copper oxidative damage is unclear. In the early stage of this application, we found that Atox1 knocked-down sheep pancreatic organoids (SPDOs) showed intolerance to copper, increased cell free copper ion, and occurred mitochondrial dysfunction. Further experiments found that Atox1 is closely related to the expression of genes involved in mitochondrial function and copper exclusion, indicating that Atox1 promotes free copper efflux and resist oxidative damage by regulating mitochondrial protein expression. This project intends to deeply analyze the mechanism of Atox1 on the regulation of mitochondrial function and promotion of free copper efflux against oxidative damage through in vivo and in vitro copper tolerance experiments, mitochondrial function analysis, transcriptome sequencing, CHIP-Seq, gene function analysis, etc. This study will provide evidence for using Atox1 in promoting of animal healthy growth and usage of copper nutrient through animal breeding.