基于UPLC-Q-TOF/MS代谢组学探究虹鳟鳃对热应激的生理反应

全球气温日趋升高导致的水温上升可引起虹鳟(Oncorhynchus mykiss)代谢紊乱,为解析其在热应激下的代谢变化特征,研究基于UPLC-Q-TOF/MS代谢组学技术,探究了虹鳟鳃靶器官在高温暴露(20℃和24℃)及恢复到初始温度(14℃)下的代谢生理反应。研究结果表明,与对照组相比,在20℃、24℃高温组和14℃恢复组中分别鉴定出128、130和108种差异显著代谢物。在高温暴露下,亚油酸、花生四烯酸等与脂质代谢相关的代谢物及还原型辅酶Ⅱ(NADPH)、谷胱甘肽(GSH)、谷胱甘肽二硫化物(GSSG)等与细胞氧化还原状态相关的代谢物均发生显著改变。富集分析表明这些代谢物主要涉及虹鳟鳃的甘油磷脂代谢、鞘脂代谢、亚油酸代谢、花生四烯酸代谢、磷酸戊糖途径和谷胱甘肽代谢等代谢通路,但在温度恢复到14℃后,除鞘脂代谢外,其他代谢途径均未恢复至正常状态。上述结果表明,热激导致了虹鳟鳃靶器官的脂质代谢紊乱,可能导致鳃细胞膜的结构和功能的损伤,诱使鳃细胞出现炎症反应,并产生免疫应答。同时,虹鳟鳃细胞通过磷酸戊糖途径产生的NADPH来调节谷胱甘肽代谢中GSH/GSSG比值以提高细胞的抗氧化能力来...

PHYSIOLOGICAL RESPONSES TO HEAT STRESS IN THE GILL OF RAINBOW TROUT (ONCORHYNCHUS MYKISS) REVEALED BASED ON UPLC-Q-TOF/MS METABOLOMICS

Rainbow trout (Oncorhynchus mykiss) is a cold-water fish widely cultivated in the world. Heat stress has a great impact on its growth and reproduction. At present, global warming and extreme high temperature in summer have seriously affected its growth and survival. To characterise their metabolic changes under heat stress, this study explored the metabolic physiological responses of rainbow trout gill target organs under high temperature exposure (20℃and 24℃) and subsequent return to initial temperature (14℃) based on UPLC-Q-TOF/MS metabolomics techniques. The results showed that compared to the control group, 128, 130 and 108 differentially significant metabolites were identified in the high temperature groups (20℃ and 24℃) and the recovery group(14℃), respectively. Metabolites related to lipid metabolism such as linoleic acid and arachidonic acid, as well as metabolites related to cellular redox status such as reduced coenzyme Ⅱ (NADPH), glutathione (GSH) and glutathione disulfide (GSSG) were significantly altered by high temperature exposure. Enrichment analysis showed that these metabolites were mainly involved in metabolic pathways such as glycerophospholipid metabolism, sphingolipid metabolism, linoleic acid metabolism, arachidonic acid metabolism, pentose phosphate pathway and glutathione metabolism in rainbow trout gills. Notably, none of the metabolic pathways, except sphingolipid metabolism, returned to normal after the temperature returned to initial. The above results suggested that heat stress led to disruption of lipid metabolism in rainbow trout gill target organs, which may lead to structural and functional damage to gill cell membranes, induced an inflammatory response in gill cells and generated an immune response. At the same time, rainbow trout gill cells regulated the GSH/GSSG ratio in glutathione metabolism through NADPH production by the pentose phosphate pathway to increase the antioxidant capacity of cells to counter oxidative stress and prevent apoptosis. The results of this study provided a scientific basis for understanding the physiological responses of rainbow trout under heat stress.