Cao Yanfei, Jiao Yu, Zhan Shuzhi, Liang Xueru, Li Zhixin, Chen Jiayi, Xiong Xinwei, Gu Zefeng, Du Xiaodong, Zheng Zhe
Fishery College, Guangdong Ocean University, Zhanjiang, China.
Pearl Breeding and Processing Engineering Technology Research Centre of Guangdong Province, Zhanjiang, China.
Front Physiol. 2021 Dec 10;12:781324. doi: 10.3389/fphys.2021.781324. eCollection 2021.
The polyamine putrescine (Put) is a ubiquitous small cationic amine. It plays an essential role in controlling the innate immune response. However, little is known about its function in mollusks. In this study, the Put content was observed to increase in the serum of pearl oyster after 6 and 24 h of lipopolysaccharide (LPS) stimulation. Activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) increased, and nitric oxide synthase was downregulated in the Put group (i.e., combined treatment with Put and LPS) compared with that in the LPS group (i.e., combined treatment with phosphate-buffered saline and LPS). Furthermore, activities of alkaline phosphatase and acid phosphatase were inhibited after 6 h of LPS stimulation. The expression levels of the nuclear factor kappa B, IκB kinase, Janus kinase, and signal transducer and activator of transcription proteins genes were all significantly suppressed at 12 and 24 h in the Put group. grew better after being incubated with the serum from the Put group than that from the LPS group. Additionally, the Put treatment remarkably inhibited the autophagy of hemocytes mediated by the AMP-activated protein kinase-mammalian target of rapamycin-Beclin-1 pathway. This study demonstrated that Put can effectively inhibit the inflammatory response induced by LPS in pearl oysters. These results provide useful information for further exploration of the immunoregulatory functions of polyamines in bivalves and contribute to the development of immunosuppressive agents.
多胺腐胺（Put）是一种普遍存在的小阳离子胺。它在控制先天免疫反应中起着至关重要的作用。然而，人们对其在软体动物中的功能知之甚少。在本研究中，观察到脂多糖（LPS）刺激6小时和24小时后，珍珠贝血清中的Put含量增加。与LPS组（即磷酸盐缓冲盐水和LPS联合处理）相比，Put组（即Put和LPS联合处理）中超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和谷胱甘肽过氧化物酶（GSH-Px）的活性增加，一氧化氮合酶下调。此外，LPS刺激6小时后碱性磷酸酶和酸性磷酸酶的活性受到抑制。在Put组中，核因子κB、IκB激酶、Janus激酶以及信号转导和转录激活蛋白基因的表达水平在12小时和24小时时均受到显著抑制。与LPS组血清孵育后，细胞生长得更好。此外，Put处理显著抑制了由AMP激活的蛋白激酶-雷帕霉素哺乳动物靶标-Beclin-1途径介导的血细胞自噬。本研究表明，Put可以有效抑制LPS诱导的珍珠贝炎症反应。这些结果为进一步探索多胺在双壳贝类中的免疫调节功能提供了有用信息，并有助于免疫抑制剂的开发。
