State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China.
State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao Marine Science and Technology Center, Qingdao, Shandong, 266237, China.
Fish Shellfish Immunol. 2024 Nov;154:109958. doi: 10.1016/j.fsi.2024.109958. Epub 2024 Oct 11.
Hepcidin belongs to a class of small cationic antimicrobial peptides rich in cysteine. It is synthesized by liver and is widely involved in host antimicrobial, antiviral and other immune responses. We identified and characterized three hepcidin genes (OpHep1, OpHep2 and OpHep3) in spotted knifejaw. All the OpHeps shared high identities with hepcidins in other teleost, containing alpha helix and β-sheets. Three OpHeps were all detected in healthy tissues, with the abundant expression in liver. They were significantly increased after Vibrio harveyi infection in the six immune-relevant tissues (liver, kidney, spleen, gill, skin and intestine). OpHeps knockdown in spotted knifejaw liver cells affected the mRNA levels of inflammation-related genes, including il1β, il6, il8, and nfκb. Further, the recombinant hepcidin proteins were effective in suppressing the growth of both Gram-negative and Gram-positive bacteria. To identify the function of OpHeps in vivo, we performed the overexpression of three OpHeps in zebrafish, and found OpHeps could significantly induce immune-related genes expression in transgenic zebrafish, including myd88, il10, il21, il16, tlr1, tlr3 and lysozyme. When infected with V. harveyi, OpHeps transgenic zebrafishes had a higher survival rate than wild-type zebrafishes. The expression of myd88, il10, il8, il1β, nfκb and lysozyme were all significantly up-regulated in transgenic fishes during bacterial infection. In summary, these results indicated that hepcidin could protect fish fight against pathogen through TLR/NFκB signaling cascade and Lysozyme. Three OpHeps would be potential targets for prevention of bacterial infections in aquaculture industry of spotted knifejaw, which provided a new idea for the molecular breeding of fish disease resistance.
亚铁调素属于富含半胱氨酸的小阳离子抗菌肽家族。它由肝脏合成，广泛参与宿主抗菌、抗病毒和其他免疫反应。我们在斑点刀颌鱼中鉴定和表征了三种亚铁调素基因（OpHep1、OpHep2 和 OpHep3）。所有 OpHeps 与其他硬骨鱼的亚铁调素有很高的同一性，含有α螺旋和β-折叠。三种 OpHeps 在健康组织中均有检测到，在肝脏中表达丰富。在 6 种免疫相关组织（肝脏、肾脏、脾脏、鳃、皮肤和肠道）受到哈维弧菌感染后，它们的表达均显著增加。斑点刀颌鱼肝细胞中的 OpHeps 敲低会影响炎症相关基因（包括 il1β、il6、il8 和 nfκb）的 mRNA 水平。此外，重组亚铁调素蛋白能有效抑制革兰氏阴性和革兰氏阳性细菌的生长。为了鉴定 OpHeps 在体内的功能，我们在斑马鱼中过表达了三种 OpHeps，发现 OpHeps 能显著诱导转基因斑马鱼中免疫相关基因的表达，包括 myd88、il10、il21、il16、tlr1、tlr3 和溶菌酶。当感染哈维弧菌时，OpHeps 转基因斑马鱼的存活率高于野生型斑马鱼。在细菌感染期间，转基因鱼类中 myd88、il10、il8、il1β、nfκb 和溶菌酶的表达均显著上调。综上所述，这些结果表明，亚铁调素可以通过 TLR/NFκB 信号级联和溶菌酶保护鱼类抵抗病原体。三种 OpHeps 可能成为斑点刀颌鱼水产养殖中预防细菌感染的潜在靶点，为鱼类抗病性的分子育种提供了新的思路。
