Key Laboratory of the Coastal and Wetland Ecosystems (Xiamen University), Ministry of Education, Xiamen University, Xiamen, Fujian 361005, China; Fujian Key Laboratory of Coastal Pollution Prevention and Control, Xiamen, Fujian 361005, China; Fudan University, Shanghai 200240, China.
Key Laboratory of the Coastal and Wetland Ecosystems (Xiamen University), Ministry of Education, Xiamen University, Xiamen, Fujian 361005, China; Bellastem Biotechnology Limited, Weifang, Shandong 261503, China.
Comp Biochem Physiol C Toxicol Pharmacol. 2020 May;231:108734. doi: 10.1016/j.cbpc.2020.108734. Epub 2020 Mar 6.
Chromium is toxic to marine animals and can cause damage to many of their organs, including the liver. To test the toxicity of chromium on marine organisms, we exposed the liver of the marine medaka (Oryzias melastigma) with hexavalent chromium [Cr(VI)]. Our results show that Cr enrichment in the liver demonstrates a positive correlation to the exposure concentration. With the increase of Cr(VI) concentration, pathological changes including nuclear migration, cell vacuolization, blurred intercellular gap, nuclear condensation, become noticeable. To further study changes in gene expression in the liver after Cr(VI) exposure, we used RNA-seq to compare expression profiles before and after Cr(VI) exposure. After acute Cr(VI) exposure (2.61 mg/l) for 96 h, 5862 transcripts significantly changed. It is the first time that the PPAR pathway was found to respond sensitively to Cr(VI) exposure in fish. Finally, combined with other published study, we found that there may be some difference between Cr(VI) toxicity in seawater fish and freshwater fish, due to degree of oxidative stress, distribution patterns and detailed Cr(VI) toxicological mechanisms. Not only does our study explore the mechanisms of Cr(VI) toxicity on the livers of marine medaka, it also points out different Cr(VI) toxicity levels and potential mechanisms between seawater fish and freshwater fish.
铬对海洋动物具有毒性，可对它们的许多器官（包括肝脏）造成损害。为了测试铬对海洋生物的毒性，我们用六价铬[Cr(VI)]处理海洋稻蝗（Oryzias melastigma）的肝脏。我们的结果表明，肝脏中铬的富集与暴露浓度呈正相关。随着 Cr(VI)浓度的增加，核迁移、细胞空泡化、细胞间间隙模糊、核浓缩等病变变得明显。为了进一步研究 Cr(VI)暴露后肝脏基因表达的变化，我们使用 RNA-seq 比较了 Cr(VI)暴露前后的表达谱。在急性 Cr(VI)暴露（2.61mg/l）96 小时后，有 5862 个转录本发生显著变化。这是首次发现鱼类的 PPAR 途径对 Cr(VI)暴露敏感。最后，结合其他已发表的研究，我们发现海水鱼和淡水鱼的 Cr(VI)毒性可能存在一些差异，这与氧化应激程度、分布模式和详细的 Cr(VI)毒理学机制有关。我们的研究不仅探讨了 Cr(VI)对海洋稻蝗肝脏的毒性机制，还指出了海水鱼和淡水鱼之间不同的 Cr(VI)毒性水平和潜在机制。
