The acute stress response is well-characterized, with rainbow trout as a teleost model for physiological and molecular responses. Air exposure, which stimulates an acute stress response, modulates liver microRNAs in rainbow trout; however, these highly conserved non-coding RNAs that bind to mRNA and repress translation, have never been measured in brook trout and it is unknown how miRNA expression responds following air exposure in this less studied salmonid. Our objective was to characterize the effects of air exposure on rainbow and brook trout liver miRNA expression, as well as the mRNA expression and enzyme activity that the miRNAs are predicted to target. Brook and rainbow trout were sampled pre- and 1-, 3-, and 24-h post- a three-minute air exposure. Plasma cortisol, glucose, and lactate were measured. Relative expression of miR-21a-5p, miR-143-3p, let-7a-5p and relative expression and enzyme activities of five predicted targets (pyruvate kinase, glucokinase, citrate synthase, cytochrome c oxidase, and catalase) were measured in liver. Rainbow and brook trout both had increases in plasma cortisol and lactate, while only rainbow trout had significant post-stress increases in plasma glucose. Furthermore, both trout species had increased miR-143-3p and miR-21a-5p relative expression 24-h post-stress. Four of the five enzymes measured had altered activity following stress. Brook trout miRNAs had inverse relative expression with relative catalase mRNA expression and cytochrome c oxidase enzyme activity, but no relationship was found in rainbow trout. Therefore, we have further characterized the transcriptional and enzymatic response to air exposure in two salmonids.

急性应激反应得到了很好的表征，虹鳟鱼是生理和分子反应的硬骨鱼模型。空气暴露会刺激急性应激反应，调节虹鳟鱼的肝脏 microRNA；然而，这些与 mRNA 结合并抑制翻译的高度保守的非编码 RNA 从未在鳟鱼中进行过测量，并且未知在这种研究较少的鲑鱼中 miRNA 表达在暴露于空气后有何反应。我们的目标是表征空气暴露对虹鳟和鳟鱼肝脏 miRNA 表达的影响，以及 miRNA 预计靶向的 mRNA 表达和酶活性。在三分钟的空气暴露前和 1、3 和 24 小时后对布鲁克鳟鱼和虹鳟鱼进行采样。测量血浆皮质醇、葡萄糖和乳酸。miR-21a-5p的相对表达，c氧化酶和过氧化氢酶）在肝脏中测量。虹鳟鱼和鳟鱼的血浆皮质醇和乳酸均增加，而只有虹鳟鱼的血浆葡萄糖在应激后显着增加。此外，两种鳟鱼物种在应激后 24 小时都增加了 miR-143-3p 和 miR-21a-5p 的相对表达。测量的五种酶中有四种在压力后活性改变。Brook trout miRNAs与过氧化氢酶mRNA的相对表达量和细胞色素c氧化酶活性呈负相关，但虹鳟鱼中未发现相关性。因此，我们进一步表征了两种鲑鱼对空气暴露的转录和酶促反应。