State Key Laboratory for Biocontrol, Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-sen University, No.132 Waihuan Dong Road, Higher Education Mega Center, Guangzhou, Guangdong, 510006, PR China.
State Key Laboratory for Biocontrol, Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-sen University, No.132 Waihuan Dong Road, Higher Education Mega Center, Guangzhou, Guangdong, 510006, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou, 510275, PR China.
Fish Shellfish Immunol. 2019 Oct;93:406-415. doi: 10.1016/j.fsi.2019.07.069. Epub 2019 Jul 29.
Mandarin fish (Siniperca chuatsi) is a universally farmed fish species in China and has a large farming scale and economic value. With the high-density cultural mode in mandarin fish, viral diseases, such as infectious spleen and kidney necrosis virus (ISKNV) and Siniperca chuatsi rhabdovirus (SCRV), have increased loss, which has seriously restricted the development of aquaculture. Y-Box binding protein 1 (YB-1) is a member of cold shock protein family that regulates multiple cellular processes. The roles of mammalian YB-1 protein in environmental stress and innate immunity have been studied well, but its roles in teleost fishes remain unknown. In the present study, the characteristic of S. chuatsi YB-1 (scYB-1) and its roles in cold stress and virus infection were investigated. The scYB-1 obtained an 1541 bp cDNA that contains a 903 bp open reading frame encoding a protein of 300 amino acids. Tissue distribution results showed that the scYB-1 is a ubiquitously expressed gene found among tissues from mandarin fish. Overexpression of scYB-1 can increase the expression levels of cold shock-responsive genes, such as scHsc70a, scHsc70b, and scp53. Furthermore, the role of scYB-1 in innate immunity was also investigated in mandarin fish fry (MFF-1) cells. The expression level of scYB-1 was significant change in response to poly (I:C), poly (dG:dC), PMA, ISKNV, or SCRV stimulation. The overexpression of scYB-1 can significantly increase the expression levels of NF-κB-responsive genes, including scIL-8, scTNF-α, and scIFN-h. The NF-κB-luciferase report assay results showed that the relative expression of luciferin was significantly increased in the cells overexpressed with scYB-1 compared with those in cells overexpressed with control plasmid. These results indicate that scYB-1 can induce the NF-κB signaling pathway in MFF-1 cells. Overexpressed scYB-1 can downregulate the expression of ISKNV viral major capsid protein (mcp) gene but upregulates the expression of SCRV mcp gene. Moreover, knockdown of scYB-1 using siRNA can upregulate the expression of ISKNV mcp gene but downregulates the expression of SCRV mcp gene. These results indicate that scYB-1 suppresses ISKNV infection while enhancing SCRV infection. The above observations suggest that scYB-1 is involved in cold stress and virus infection. Our study will provide an insight into the roles of teleost fish YB-1 protein in stress response and innate immunity.
鳜鱼（Siniperca chuatsi）是中国广泛养殖的鱼类品种，养殖规模大，经济价值高。随着鳜鱼高密度养殖模式的发展，传染性脾肾坏死病毒（ISKNV）和鳜鱼虹彩病毒（SCRV）等病毒性疾病的发病率不断上升，给养殖业造成了严重损失。Y 盒结合蛋白 1（YB-1）是冷休克蛋白家族的一员，调节多种细胞过程。哺乳动物 YB-1 蛋白在环境应激和固有免疫中的作用已得到很好的研究，但在硬骨鱼类中的作用尚不清楚。本研究探讨了鳜鱼 YB-1（scYB-1）的特性及其在冷应激和病毒感染中的作用。获得了 scYB-1 的 1541bp cDNA，其中包含一个 903bp 的开放阅读框，编码 300 个氨基酸的蛋白质。组织分布结果表明，scYB-1 是一种广泛表达的基因，在鳜鱼组织中均有表达。scYB-1 的过表达可以增加冷应激反应基因，如 scHsc70a、scHsc70b 和 scp53 的表达水平。此外，还研究了 scYB-1 在鳜鱼仔鱼（MFF-1）细胞中的固有免疫作用。scYB-1 的表达水平在 Poly（I:C）、Poly（dG:dC）、PMA、ISKNV 或 SCRV 刺激后发生显著变化。scYB-1 的过表达可以显著增加 NF-κB 反应基因，如 scIL-8、scTNF-α 和 scIFN-h 的表达水平。NF-κB-荧光素酶报告基因检测结果表明，与对照组质粒转染的细胞相比，scYB-1 过表达的细胞中荧光素酶的相对表达明显增加。这些结果表明，scYB-1 可以诱导 MFF-1 细胞中的 NF-κB 信号通路。过表达 scYB-1 可以下调 ISKNV 病毒主要衣壳蛋白（mcp）基因的表达，但上调 SCRV mcp 基因的表达。此外，使用 siRNA 敲低 scYB-1 可以上调 ISKNV mcp 基因的表达，但下调 SCRV mcp 基因的表达。这些结果表明，scYB-1 抑制 ISKNV 感染，同时增强 SCRV 感染。上述观察结果表明，scYB-1 参与了冷应激和病毒感染。本研究将为硬骨鱼类 YB-1 蛋白在应激反应和固有免疫中的作用提供新的认识。
