INRAE, E2S UPPA, Nutrition Metabolism, Aquaculture, Univ. Pau & Pays Adour, 64310 Saint Pée-sur-Nivelle, France; INRAE, UR1037 Fish Physiology and Genomic Laboratory, F-35000 Rennes, France.
IRISA, INRIA, CNRS, University of Rennes 1, UMR 6074, F-35000, Rennes, France.
Sci Total Environ. 2022 Dec 20;853:158584. doi: 10.1016/j.scitotenv.2022.158584. Epub 2022 Sep 8.
Stresses associated with changes in diet or environmental disturbances are common situations that fish encounter during their lifetime. The stability and ease of measuring microRNAs (miRNAs) present in biological fluids make these molecules particularly interesting biomarkers for non-lethal assessment of stress in animals. Rainbow trout were exposed for four weeks to abiotic stress (moderate hypoxia) and/or nutritional stress (a high-carbohydrate/low-protein diet). Blood plasma and epidermal mucus were sampled at the end of the experiment, and miRNAs were assessed using small RNA sequencing. We identified four miRNAs (miR-122-5p, miR-184-3p, miR-192-5p and miR-194a-5p) and three miRNAs (miR-210-3p, miR-153a-3p and miR-218c-5p) that accumulated in response to stress in blood plasma and epidermal mucus, respectively. In particular, the abundance of miR-210-3p, a hypoxamiR in mammals, increased strongly in the epidermal mucus of rainbow trout subjected to moderate hypoxia, and can thus be considered a relevant biomarker of hypoxic stress in trout. We explored the contribution of 22 tissues/organs to the abundance of circulating miRNAs (c-miRNAs) in blood plasma and epidermal mucus influenced by the treatments. Some miRNAs were tissue-specific, while others were distributed among several tissues. Some c-miRNAs (e.g., miR-210-3p, miR184-3p) showed similar variations in both tissues and fluids, while others showed an inverse trend (e.g., miR-122-5p) or no apparent relationship (e.g. miR-192-5p, miR-194a-5p. Overall, these results demonstrate that c-miRNAs can be used as non-lethal biomarkers to study stress in fish. In particular, the upregulation of miR-210-3p in epidermal mucus induced by hypoxia demonstrates the potential of using epidermal mucus as a matrix for identifying non-invasive biomarkers of stress. This study provides information about the tissue sources of c-miRNAs and highlights the potential difficulty in relating variations in miRNA abundance in biological fluids to that in tissues.
与饮食变化或环境干扰相关的应激是鱼类在其一生中经常遇到的常见情况。生物体液中存在的 microRNAs (miRNAs) 的稳定性和易于测量使得这些分子成为研究动物非致死性应激的特别有趣的生物标志物。虹鳟鱼被暴露于非生物应激（中度缺氧）和/或营养应激（高碳水化合物/低蛋白饮食）下四周。在实验结束时采集血浆和表皮黏液样本，并使用小 RNA 测序评估 miRNAs。我们鉴定了四个在血浆中响应应激而积累的 miRNAs（miR-122-5p、miR-184-3p、miR-192-5p 和 miR-194a-5p）和三个在表皮黏液中响应应激而积累的 miRNAs（miR-210-3p、miR-153a-3p 和 miR-218c-5p）。特别是，哺乳动物中的缺氧诱导 miRNA miR-210-3p 的丰度在中度缺氧的虹鳟鱼的表皮黏液中强烈增加，因此可以被认为是虹鳟鱼缺氧应激的相关生物标志物。我们探讨了 22 种组织/器官对受处理影响的血浆和表皮黏液中循环 miRNAs (c-miRNAs) 丰度的贡献。一些 miRNAs 是组织特异性的，而其他则分布在几种组织中。一些 c-miRNAs（例如，miR-210-3p、miR184-3p）在组织和液体中表现出相似的变化，而其他则表现出相反的趋势（例如，miR-122-5p）或没有明显的关系（例如，miR-192-5p、miR-194a-5p）。总的来说，这些结果表明 c-miRNAs 可以用作研究鱼类应激的非致死性生物标志物。特别是，缺氧诱导的表皮黏液中 miR-210-3p 的上调表明，使用表皮黏液作为鉴定非侵入性应激生物标志物的基质具有潜力。本研究提供了有关 c-miRNAs 组织来源的信息，并强调了将生物体液中 miRNA 丰度的变化与组织中 miRNA 丰度的变化相关联的潜在困难。
