铁离子对斑马鱼肝脏细胞应激低氧胁迫的影响

水体急性低氧一直是水产养殖中的棘手问题，而铁代谢在鱼类低氧应激中发挥着极其重要的作用。为探究铁离子对鱼类应激低氧胁迫的影响，本研究以模式生物斑马鱼的肝脏细胞（ZFL）为研究对象，利用柠檬酸铁胺（FAC）对ZFL细胞进行外源补铁，同时用去铁胺（DFO）清除ZFL细胞的内源及外源铁，比较不同处理条件下ZFL细胞对低氧胁迫的应激反应。结果表明，低氧胁迫显著降低了ZFL细胞的增殖能力和存活率，而与清除内源及外源铁相比，补充外源铁能够明显改善ZFL细胞的增殖能力和存活率。同时，Western blot的结果显示补充外源铁显著提高了低氧胁迫下的ZFL细胞中铁蛋白的表达量。此外，通过qRT-PCR比较在该条件下与铁吸收（tfa）、铁储存（fthl27、fthl28、fthl31）和铁输出（fpn）相关基因的mRNA表达水平，结果表明均显著提高。进一步对低氧胁迫下ZFL细胞内活性氧（ROS）水平进行检测，发现补充外源铁能够在一定程度上恢复ZFL细胞中ROS的水平，由此证明在一定范围内胞内ROS水平的增加有利于ZFL细胞抵抗低氧胁迫。可为探究低氧导致的鱼类相关疾病提供理论基础，为低氧导致养殖鱼类产量低下提供解决办法。

Effect of iron on zebrafish liver cells under hypoxic stress

Acute hypoxia in water has always been a thorny problem in aquaculture, and iron metabolism plays an extremely important role in hypoxia stress in fish. To explore the effect of iron ions on hypoxia stress in fish, the zebrafish liver cells (ZFL) as the research object, ammonium ferric citrate (FAC) was used to supplement ZFL cells with exogenous iron, at the same time endogenous and exogenous iron in ZFL cells were also removed with desferrioxamine (DFO), then compare the stress response of ZFL cells to hypoxia stress under different treatment conditions. The results showed that hypoxic stress significantly reduced the proliferation ability and survival rate of ZFL cells, and supplementation with exogenous iron significantly improved the proliferation ability and survival rate of ZFL cells compared with scavenging endogenous and exogenous iron. Meanwhile, Western blot results showed that supplementation with exogenous iron significantly increased the ferritin expression in ZFL cells under hypoxia stress. In addition, qRT-PCR was used to compare the mRNA expression levels of iron absorption (tfa), iron storage (fthl27, fthl28, fthl31) and iron output (fpn) under this condition, and the results showed that the mRNA expression levels were significantly increased. Further detection of reactive oxygen species (ROS) levels in ZFL cells under hypoxic stress showed that supplemental exogenous iron could restore ROS levels in ZFL cells to a certain extent, which proved that the increase of intracellular ROS levels in a certain range was beneficial to the resistance of ZFL cells to hypoxic stress. It can provide a theoretical basis for exploring the fish-related diseases caused by hypoxia and provide a solution for the low yield of farmed fish caused by hypoxia.