Aquaculture of rainbow trout (Oncorhynchus mykiss) is severely hampered by high temperatures in summer, and understanding the regulatory mechanisms controlling responses to chronic heat stress may assist the development of measures to relieve heat stress. In the present study, biochemical parameters revealed a strong stress response in rainbow trout at 24 °C, including activation of stress defence and immune systems. Liver proteome analysis under heat stress (24 °C) and control (18 °C) conditions using DIA/SWATH identified precursors (90,827), peptides (67,028), proteins (6770) and protein groups (5124), among which 460 differentially abundant proteins (DAPs; q-value < 0.05, fold change >1.5), 201 and 259 were up- and down-regulated, respectively. Many were related to heat shock proteins (HSPs), metabolism and immunity. Gene Ontology (GO) analysis showed that some DAPs induced at high temperature were involved in regulating cell homeostasis, metabolism, adaptive stress and stimulation. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis identified metabolic pathways, protein processing in endoplasmic reticulum, PPAR signalling, and complement and coagulation cascades. Protein-protein interaction (PPI) network analysis indicated that HSP90b1 and C3 may cooperative to affect cell membrane integrity under heat stress. Our findings assist the development of strategies to relieve heat stress in rainbow trout.

夏季的高温严重阻碍了虹鳟（Oncorhynchus mykiss）的水产养殖，了解控制慢性热应激反应的调节机制可能有助于缓解热应激的措施的开发。在本研究中，生化参数显示虹鳟在24°C时具有强烈的应激反应，包括应激防御和免疫系统的激活。使用DIA / SWATH在热应激（24°C）和对照（18°C）条件下进行肝蛋白质组分析，确定了前体（90,827），肽（67,028），蛋白质（6770）和蛋白质组（5124），其中460个差异丰富蛋白质（DAP; q值 <0.05，倍数变化> 1.5），分别将201和259上调和下调。许多与热休克蛋白（HSP），新陈代谢和免疫力有关。基因本体论（GO）分析表明，高温诱导的某些DAP参与调节细胞稳态，代谢，适应性应激和刺激。京都基因与基因组百科全书（KEGG）分析确定了代谢途径，内质网中的蛋白质加工，PPAR信号传导以及补体和凝血级联反应。蛋白质-蛋白质相互作用（PPI）网络分析表明，HSP90b1和C3可能在热胁迫下协同影响细胞膜的完整性。我们的发现有助于开发缓解虹鳟鱼热应激的策略。