Laboratory of Aquatic Animal Health Management, Department of Aquaculture, Faculty of Fisheries, Kasetsart University, 50 Paholayothin Rd, Ladyao, Chatuchak, Bangkok 10900, Thailand.
Department of Fish Health Management and Aquaculture, Faculty of Fisheries and Marine, Universitas Airlangga, Campus C Mulyorejo, Surabaya 60115, Indonesia.
Biomolecules. 2020 Jul 31;10(8):1132. doi: 10.3390/biom10081132.
In this study, the functions of a recombinant propeptide (rPro-Hep1) and the synthetic FITC-labelled mature peptides sMat-Hep1 and sMat-Hep2 were analyzed. Moreover, sMat-Hep1 and sMat-Hep2 were mildly detected in the lymphocytes of peripheral blood mononuclear cells (PBMCs) and strongly detected in head kidney macrophages. The in vitro binding and antibacterial activities of these peptides were slightly effective against several pathogenic bacteria. Immune regulation by sMat-Hep1 was also analyzed, and only sMat-Hep1 significantly enhanced the phagocytic index in vitro ( < 0.05). Interestingly, intraperitoneal injection of sMat-Hep1 (10 or 100 µg) significantly elevated the phagocytic activity, phagocytic index, and lysozyme activity and clearly decreased the iron ion levels in the livers of the treated fish ( < 0.05). Additionally, sMat-Hep1 enhanced the expression levels of and , and both -Hep genes in the liver, spleen and head kidney, for 1-96 h after injection, but did not properly protect the experimental fish from infection after 7 days of treatment. However, the injection of and -Heps indicated that 100 μg of sMat-Hep1 was very effective, while 100 μg of rPro-Hep1 and sMat-Hep2 demonstrated moderate protection. Therefore, -Hep is a crucial iron-regulating molecule and a key immune regulator of disease resistance in Nile tilapia.
在这项研究中，分析了重组前肽（rPro-Hep1）和合成 FITC 标记的成熟肽 sMat-Hep1 和 sMat-Hep2 的功能。此外，sMat-Hep1 和 sMat-Hep2 在外周血单个核细胞（PBMCs）的淋巴细胞中轻度检测到，在头肾巨噬细胞中强烈检测到。这些肽的体外结合和抗菌活性对几种致病菌具有轻微的效果。还分析了 sMat-Hep1 的免疫调节作用，只有 sMat-Hep1 显著增强了体外的吞噬指数（<0.05）。有趣的是，腹腔注射 sMat-Hep1（10 或 100μg）可显著提高吞噬活性、吞噬指数和溶菌酶活性，并明显降低处理鱼肝脏中的铁离子水平（<0.05）。此外，sMat-Hep1 增强了注射后 1-96 小时肝脏、脾脏和头肾中 、 和 的表达水平，而在治疗 7 天后，sMat-Hep1 不能很好地保护实验鱼免受感染。然而，注射 和 -Heps 表明 100μg 的 sMat-Hep1 非常有效，而 100μg 的 rPro-Hep1 和 sMat-Hep2 则表现出中等保护作用。因此，-Hep 是尼罗罗非鱼中关键的铁调节分子和疾病抗性的关键免疫调节剂。
