García-Navarro Laura, Serna-Duque Jhon A, Cuesta Alberto, Esteban M Ángeles
Immunobiology for Aquaculture Group, Department of Cell Biology and Histology, Faculty of Biology, University of Murcia, 30100, Murcia, Spain.
Immunobiology for Aquaculture Group, Department of Cell Biology and Histology, Faculty of Biology, University of Murcia, 30100, Murcia, Spain.
Microb Pathog. 2025 Aug;205:107695. doi: 10.1016/j.micpath.2025.107695. Epub 2025 May 13.
Antimicrobial peptides (AMPs) are highly conserved small molecules present in various organisms, including fish. In gilthead seabream (Sparus aurata), one hamp1 and 15 hamp2 genes have been identified. This study aimed to characterize two novel hamp2 genes, hamp2.0 and hamp2.15, located on chromosome 17 of the gilthead seabream genome. Evolutionary analysis revealed that orthologs of both genes first appeared in the Clupeocephala clade 229 million years ago. In silico analysis predicted that the mature peptides, Hamp2α and Hamp2Ω, possess antimicrobial properties. Both peptides exhibited bactericidal activity against Vibrio harveyi, with Hamp2α showing concentration-dependent inhibition and Hamp2Ω demonstrating time-dependent inhibition. Neither peptide displayed cytotoxicity against SAF-1 cells; instead, they promoted cell proliferation. Basal expression of both genes was observed in all tissues analyzed, with the highest levels in liver and gonad. In head kidney leucocytes (HKLs), expression of both genes increased upon stimulation with lypopolysaccharide, poly I:C, nodavirus, or V. anguillarum. In vivo, hamp2.0 expression significantly increased in various tissues of V. harveyi-infected fish, while hamp2.15 expression increased in liver, spleen, head kidney, skin, and brain. In nodavirus-infected fish, hamp2.15 expression decreased in head kidney and brain. Finally, both genes showed significantly increased expression in head kidney and liver 72 h post-iron dextran injection. These findings suggest that the two novel hamp2 genes in gilthead seabream play a role in the immune response to bacterial and viral infections and may be involved in iron metabolism regulation.
抗菌肽（AMPs）是存在于包括鱼类在内的各种生物体中的高度保守的小分子。在金头鲷（Sparus aurata）中，已鉴定出1个hamp1基因和15个hamp2基因。本研究旨在表征位于金头鲷基因组17号染色体上的两个新的hamp2基因，即hamp2.0和hamp2.15。进化分析表明，这两个基因的直系同源物最早出现在2.29亿年前的栉鳞鱼亚派中。生物信息学分析预测，成熟肽Hamp2α和Hamp2Ω具有抗菌特性。两种肽均对哈维氏弧菌表现出杀菌活性，Hamp2α表现出浓度依赖性抑制，而Hamp2Ω表现出时间依赖性抑制。两种肽对SAF-1细胞均无细胞毒性；相反，它们促进细胞增殖。在所分析的所有组织中均观察到这两个基因的基础表达，在肝脏和性腺中的表达水平最高。在头肾白细胞（HKLs）中，用脂多糖、聚肌胞苷酸、诺达病毒或鳗弧菌刺激后，这两个基因的表达均增加。在体内，哈维氏弧菌感染的鱼的各个组织中hamp2.0表达显著增加，而hamp2.15在肝脏、脾脏、头肾、皮肤和大脑中的表达增加。在诺达病毒感染的鱼中，hamp2.15在头肾和大脑中的表达下降。最后。最后，在右旋糖酐铁注射72小时后，这两个基因在头肾和肝脏中的表达均显著增加。这些发现表明，金头鲷中的两个新的hamp2基因在对细菌和病毒感染的免疫反应中起作用，并且可能参与铁代谢调节。
