Université de Pau et des Pays de l'Adour, E2S UPPA, INRAE, NUMEA, 64310 Saint-Pée-sur-Nivelle, France.
Evonik Operations GmbH, Rodenbacher Chaussee 4, 4D-63457 Hanau, Germany.
Int J Mol Sci. 2022 Mar 8;23(6):2935. doi: 10.3390/ijms23062935.
The replacement of fishmeal by plant proteins in aquafeeds imposes the use of synthetic methionine (MET) sources to balance the amino acid composition of alternative diets and so to meet the metabolic needs of fish of agronomic interest such as rainbow trout (RT-). Nonetheless, debates still exist to determine if one MET source is more efficiently used than another by fish. To address this question, the use of fish cell lines appeared a convenient strategy, since it allowed to perfectly control cell growing conditions notably by fully depleting MET from the media and studying which MET source is capable to restore cell growth/proliferation and metabolism when supplemented back. Thus, results of cell proliferation assays, Western blots, RT-qPCR and liquid chromatography analyses from two RT liver-derived cell lines revealed a better absorption and metabolization of DL-MET than DL-Methionine Hydroxy Analog (MHA) with the activation of the mechanistic Target Of Rapamycin (mTOR) pathway for DL-MET and the activation of integrated stress response (ISR) pathway for MHA. Altogether, the results clearly allow to conclude that both synthetic MET sources are not biologically equivalent, suggesting similar in vivo effects in RT liver and, therefore, questioning the MHA efficiencies in other RT tissues.
在水产饲料中用植物蛋白替代鱼粉会迫使使用合成蛋氨酸（MET）来源来平衡替代饲料的氨基酸组成，以满足如虹鳟（RT-）等具有农业意义的鱼类的代谢需求。然而，关于鱼类对一种 MET 来源的利用率是否高于另一种，仍存在争议。为了解决这个问题，使用鱼类细胞系似乎是一种方便的策略，因为它可以完全控制细胞的生长条件，特别是通过从培养基中完全耗尽 MET，并研究哪种 MET 来源在补充回细胞时能够恢复细胞生长/增殖和代谢。因此，来自两个 RT 肝衍生细胞系的细胞增殖测定、Western blot、RT-qPCR 和液相色谱分析的结果表明，DL-MET 的吸收和代谢优于 DL-蛋氨酸羟基类似物（MHA），DL-MET 激活了雷帕霉素靶蛋白（mTOR）途径，而 MHA 激活了综合应激反应（ISR）途径。总的来说，这些结果清楚地表明，两种合成 MET 来源在生物学上并不等效，这表明它们在 RT 肝脏中有类似的体内效应，因此质疑 MHA 在其他 RT 组织中的效率。
