Gao Feng, Shi Xiaowei, Zhao Yanjing, Qiao Dan, Pei Chao, Li Chen, Zhao Xianliang, Kong Xianghui
Engineering Lab of Henan Province for Aquatic Animal Disease Control, College of Fisheries, Henan Normal University, Henan Province, PR China.
Engineering Lab of Henan Province for Aquatic Animal Disease Control, College of Fisheries, Henan Normal University, Henan Province, PR China; Sanquan Medical College, Henan Province, PR China.
Fish Shellfish Immunol. 2023 Oct;141:109058. doi: 10.1016/j.fsi.2023.109058. Epub 2023 Sep 8.
Prostaglandin-endoperoxide synthase 2 (PTGS2), a crucial enzyme in prostaglandin synthesis, catalyzes the conversion of arachidonic acid to prostaglandins and plays a significant role in the inflammatory response. This investigation aimed to determine the regulatory role of PTGS2a in the innate immune response to bacterial infection in fish. To achieve this objective, the CcPTGS2a gene was identified and characterized in common carp (Cyprinus carpio), and its function in immune defense was investigated. According to the sequence and structural analysis results, CcPTGS2a had an open reading frame of 1806 bp that encoded 602 amino acids. It was estimated that the protein's theoretical molecular weight was 69.0 kDa, and its isoelectric point was 8.10. The structure of CcPTGS2a was observed to be conserved, with an epidermal growth factor domain and a peroxidase domain present. Moreover, the amino acid sequence of CcPTGS2a exhibited significant homology with the amino acid sequences of several fish species. CcPTGS2a mRNA was detected in the healthy tissues of common carp, with higher expression in the head kidney, spleen, gills, and liver. Following the challenges with Aeromonas hydrophila and lipopolysaccharide, CcPTGS2a mRNA showed unique geographic and temporal expression patterns, with significant increases detected in the head kidney, gills, spleen, and liver. Additionally, the recombinant CcPTGS2a protein exhibited detectable bacterial binding to various bacteria. As determined by subcellular localization analysis, CcPTGS2a was predominantly localized in the nucleus and cytoplasm. Furthermore, it was discovered that the overexpression of CcPTGS2a stimulated the up-regulation of ferroptosis-related genes and inflammatory cytokine mRNA expression in fish and EPC (Epithelioma papulosum cyprinid) cells while concurrently reducing the bacterial load of A. hydrophila. In contrast, the interference of CcPTGS2a decreased the mRNA expression of ferroptosis-related genes and inflammatory cytokines in fish and EPC cells and increased the bacterial load of A. hydrophila. Notably, A. hydrophila stimulation resulted in the up-regulation of CcPTGS2a protein expression in EPC cells. These results suggested that CcPTGS2a was involved in the immune response to bacterial infections in common carp.
前列腺素 - 内过氧化物合酶2（PTGS2）是前列腺素合成中的一种关键酶，催化花生四烯酸转化为前列腺素，并在炎症反应中发挥重要作用。本研究旨在确定PTGS2a在鱼类对细菌感染的先天免疫反应中的调节作用。为实现这一目标，在鲤鱼（Cyprinus carpio）中鉴定并表征了CcPTGS2a基因，并研究了其在免疫防御中的功能。根据序列和结构分析结果，CcPTGS2a具有1806 bp的开放阅读框，编码602个氨基酸。估计该蛋白的理论分子量为69.0 kDa，其等电点为8.10。观察到CcPTGS2a的结构保守，存在表皮生长因子结构域和过氧化物酶结构域。此外，CcPTGS2a的氨基酸序列与几种鱼类的氨基酸序列具有显著同源性。在鲤鱼的健康组织中检测到CcPTGS2a mRNA，在头肾、脾脏、鳃和肝脏中表达较高。在用嗜水气单胞菌和脂多糖刺激后，CcPTGS2a mRNA呈现独特的时空表达模式，在头肾、鳃、脾脏和肝脏中检测到显著增加。此外，重组CcPTGS2a蛋白显示出与各种细菌的可检测结合。通过亚细胞定位分析确定，CcPTGS2a主要定位于细胞核和细胞质中。此外，发现CcPTGS2a的过表达刺激了鱼类和EPC（鲤鱼上皮瘤）细胞中与铁死亡相关基因和炎性细胞因子mRNA表达的上调，同时降低了嗜水气单胞菌的细菌载量。相反，CcPTGS2a的干扰降低了鱼类和EPC细胞中与铁死亡相关基因和炎性细胞因子的mRNA表达，并增加了嗜水气单胞菌的细菌载量。值得注意的是，嗜水气单胞菌刺激导致EPC细胞中CcPTGS2a蛋白表达上调。这些结果表明CcPTGS2a参与了鲤鱼对细菌感染的免疫反应。
