College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animal, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Institutes, Southern Marine Science and Engineering Guangdong Laboratory, Zhanjiang, China.
College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animal, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Institutes, Southern Marine Science and Engineering Guangdong Laboratory, Zhanjiang, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China; Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen, China.
Fish Shellfish Immunol. 2024 Oct;153:109845. doi: 10.1016/j.fsi.2024.109845. Epub 2024 Aug 17.
High mobility group protein B2 (HMGB2) is an abundant chromatin-associated protein with pivotal roles in transcription, cell proliferation, differentiation, inflammation, and tumorigenesis. However, its immune function in Nile tilapia (Oreochromis niloticus) remains unclear. In this study, we identified a homologue of HMGB2 from Nile tilapia (On-HMGB2) and investigated its functions in the immune response against streptococcus infection. The open reading frame (ORF) of On-HMGB2 spans 642 bp, encoding 213 amino acids, and contains two conserved HMG domains. On-HMGB2 shares over 80 % homology with other fish species and 74%-76 % homology with mammals. On-HMGB2 was widely distributed in various tissues, with its highest transcript levels in the liver and the lowest in the intestine. Knockdown of On-HMGB2 promoted the inflammatory response in Nile tilapia, increased the bacterial load in the tissues, and led to elevated mortality in Nile tilapia following Streptococcus agalactiae infection. Taken together, On-HMGB2 significantly influences the immune system of Nile tilapia in response to streptococcus infection.
高迁移率族蛋白 B2（HMGB2）是一种丰富的染色质相关蛋白，在转录、细胞增殖、分化、炎症和肿瘤发生中具有关键作用。然而，其在尼罗罗非鱼（Oreochromis niloticus）中的免疫功能尚不清楚。在本研究中，我们从尼罗罗非鱼（On-HMGB2）中鉴定出 HMGB2 的同源物，并研究了其在链球菌感染免疫反应中的功能。On-HMGB2 的开放阅读框（ORF）跨越 642bp，编码 213 个氨基酸，包含两个保守的 HMG 结构域。On-HMGB2 与其他鱼类物种的同源性超过 80%，与哺乳动物的同源性为 74%-76%。On-HMGB2 在各种组织中广泛分布，其在肝脏中的转录水平最高，在肠道中的转录水平最低。On-HMGB2 的敲低促进了尼罗罗非鱼的炎症反应，增加了组织中的细菌负荷，并导致链球菌感染后尼罗罗非鱼的死亡率升高。综上所述，On-HMGB2 显著影响尼罗罗非鱼对链球菌感染的免疫系统。
