随着全世界饲料中抗生素的禁止，抗菌肽（AMP）被认为是更有前途的替代抗生素用作饲料添加剂，在牲畜喂养研究中已经报道了积极的结果。然而,膳食补充AMPs是否可以促进鱼类等海水养殖动物的生长及其潜在机制尚未阐明。在研究中,Scy-hepc的重组AMP产品用作膳食补充剂（10mg/kg），以平均初始体重（BW）为52.9g的海水养殖幼鱼大黄鱼（Larimichthyscrocea）喂养150天。在喂养试验期间，饲喂Scy-hepc的鱼表现出显著的促生长性能。尤其是在进食后60天，用Scy-hepc喂养的鱼比对照组重约23%。进一步证实了生长相关的信号通路如GH-Jak2-STAT5-IGF1生长轴,Scy-hepc喂养后，肝脏中的PI3K-Akt和Erk/MAPK通路均被激活。此外，第二次重复喂养试验计划使用小得多的幼年大黄鱼，平均初始BW为6.3g，为期30天，并观察到类似的阳性结果。进一步的研究表明，PI3K-Akt通路的下游效应子，如p70S6K和4EBP1，被显著磷酸化，提示Scy-hepc喂养可能促进肝脏中的翻译起始和蛋白质合成过程。一起来看,作为先天免疫的效应器，AMPScy-hepc在促进大黄鱼的生长中起作用，其潜在机制与GH-Jak2-STAT5-IGF1轴的激活有关，以及PI3K-Akt和Erk/MAPK信号通路。
With the antibiotics prohibition in feedstuffs worldwide, antimicrobial peptides (AMPs) are considered a more promising substitute for antibiotics to be used as feed additives, and positive results have been reported in livestock feeding studies. However, whether dietary supplementation of AMPs could promote the growth of mariculture animals such as fish and the underlying mechanism has not been elucidated yet. In the study, a recombinant AMP product of Scy-hepc was used as a dietary supplement (10 mg/kg) to feed mariculture juvenile large yellow croaker (Larimichthys crocea) with an average initial body weight (BW) of 52.9 g for 150 days. During the feeding trial, the fish fed with Scy-hepc showed a significant growth-promoting performance. Especially at 60 days after feeding, fish fed with Scy-hepc weighed approximately 23% more than the control group. It was further confirmed that the growth-related signaling pathways such as the GH-Jak2-STAT5-IGF1 growth axis, the PI3K-Akt and Erk/MAPK pathways were all activated in the liver after Scy-hepc feeding. Furthermore, a second repeated feeding trial was scheduled for 30 days using much smaller juvenile L. crocea with an average initial BW of 6.3 g, and similar positive results were observed. Further investigation revealed that the downstream effectors of the PI3K-Akt pathway, such as p70S6K and 4EBP1, were significantly phosphorylated, suggesting that Scy-hepc feeding might promote translation initiation and protein synthesis processes in the liver. Taken together, as an effector of innate immunity, AMP Scy-hepc played a role in promoting the growth of L. crocea and the underlying mechanism was associated with the activation of the GH-Jak2-STAT5-IGF1 axis, as well as the PI3K-Akt and Erk/MAPK signaling pathways.
