Zhou Zhenzhen, Chen Fangyi, Hao Hua, Wang Ke-Jian
State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China.
State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China; State-Province Joint Engineering Laboratory of Marine Bioproducts and Technology, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China; Fujian Innovation Research Institute for Marine Biological Antimicrobial Peptide Industrial Technology, College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China.
Fish Shellfish Immunol. 2025 Jun;161:110279. doi: 10.1016/j.fsi.2025.110279. Epub 2025 Mar 13.
Antimicrobial peptides (AMPs) are considered a key component of innate immunity, playing a vital role in host defense. In the study, a novel functional gene, named Larimicin, was identified from large yellow croaker Larimichthys crocea. The Larimicin gene was widely distributed in multiple tissues of healthy L. crocea and was significantly induced in the liver after Vibrio alginolyticus or Vibrio parahaemolyticus infection. Larimicin, a truncated peptide derived from Larimicin, showed broad-spectrum antimicrobial activity and a binding affinity with LPS. It exhibited effective bactericidal activity against the common aquatic pathogens Vibrio fluvialis, Pseudomonas fluorescens, and Pseudomonas putida. It also showed anti-biofilm activity against three aquatic pathogens. Moreover, Larimicin disrupted the integrity of the outer and inner membranes, resulting in ATP leakage and intracellular ROS accumulation, which ultimately led to bacterial cell death. Larimicin exhibited good thermal stability and cation tolerance, with no obvious cytotoxicity or hemolytic activity. Notably, Larimicin significantly improved the survival rate of L. crocea infected with V. fluvialis, raising it to 95 %, indicating its anti-infective role in vivo. In addition, Larimicin significantly reduced the expression of the pro-inflammatory cytokines TNF-α and IL-1β, while up-regulating the anti-inflammatory factor IL-4 mRNA level. It also elevated the expression levels of piscidin, hepcidin, and lysozyme, as well as enhanced the enzymatic activity of lysozyme. Taken together, Larimicin is a potential antibacterial agent for use in aquaculture to combat V. fluvialis infection diseases in the future.
抗菌肽（AMPs）被认为是固有免疫的关键组成部分，在宿主防御中发挥着至关重要的作用。在这项研究中，从大黄鱼（Larimichthys crocea）中鉴定出一个名为Larimicin的新型功能基因。Larimicin基因广泛分布于健康大黄鱼的多个组织中，在溶藻弧菌或副溶血性弧菌感染后，肝脏中的该基因表达显著上调。Larimicin是一种源自Larimicin的截短肽，具有广谱抗菌活性并与脂多糖（LPS）有结合亲和力。它对常见的水生病原菌河流弧菌、荧光假单胞菌和恶臭假单胞菌表现出有效的杀菌活性。它还对三种水生病原菌显示出抗生物膜活性。此外，Larimicin破坏了细菌外膜和内膜的完整性，导致三磷酸腺苷（ATP）泄漏和细胞内活性氧（ROS）积累，最终导致细菌细胞死亡。Larimicin表现出良好的热稳定性和阳离子耐受性，没有明显的细胞毒性或溶血活性。值得注意的是，Larimicin显著提高了感染河流弧菌的大黄鱼的存活率，将其提高到95%，表明其在体内的抗感染作用。此外，Larimicin显著降低了促炎细胞因子肿瘤坏死因子-α（TNF-α）和白细胞介素-1β（IL-1β）的表达，同时上调了抗炎因子白细胞介素-4（IL-4）的mRNA水平。它还提高了鱼抗菌肽、抗菌肽和溶菌酶的表达水平，并增强了溶菌酶的酶活性。综上所述，Larimicin是一种潜在的抗菌剂，未来可用于水产养殖以对抗河流弧菌感染疾病。
