Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210023, China.
Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210023, China; Co-Innovation Center for Marine Bio-Industry Technology of Jiangsu Province, Lianyungang, Jiangsu 222005, China.
Fish Shellfish Immunol. 2018 May;76:21-26. doi: 10.1016/j.fsi.2018.02.036. Epub 2018 Feb 21.
Serpin families classified serine protease inhibitors regulate various physiological processes. However, there is not study on the role of serpin in immune responses against Spiroplasma eriocheiris as a novel causative pathogen in the Chinese mitten crab, Eriocheir sinensis. In our study, quantitative real-time PCR (qRT-PCR) revealed that the mRNA transcripts of Esserpin-2 were ubiquitous in every tissue, relative higher expression in hepatopancreas, gill and hemocytes, while the intestine, muscle, heart and nerve showed relative lower expression. Followed by infection with S. eriocheiris, the transcripts of Esserpin-2 were significantly down-regulated from 1 d to 7 d. After double-stranded RNA injection, the transcripts of Esserpin-2 dramatically declined from 48 h to 96 h. The transcripts of proPO were found to be obviously increased after Esserpin-2 silenced, meanwhile, LGBP with no significant difference. The copy number of S. eriocheiris and subsequently the mortality of crabs in a silencing Esserpin-2 group were significantly less than control groups during infection. The subcellular localization experiment suggested that recombinant Esserpin-2 was mainly located in the cytoplasm. Finally, over-expression assay in Drosophila S2 cells indicated that Esserpin-2 could increase copies of S. eriocheiris and result in cell death. These findings demonstrated that Esserpin-2 involved in the innate immune mechanism of E. sinensis in response to S. eriocheiris infection.
丝氨酸蛋白酶抑制剂家族分类调节各种生理过程。然而，目前还没有关于丝氨酸蛋白酶抑制剂在中华绒螯蟹（Eriocheir sinensis）新型病原体 S. eriocheiris 免疫反应中的作用的研究。在本研究中，实时定量 PCR（qRT-PCR）显示，Esserpin-2 的 mRNA 转录本在所有组织中普遍存在，在肝胰腺、鳃和血细胞中相对较高表达，而肠、肌肉、心脏和神经中相对较低表达。接着感染 S. eriocheiris 后，Esserpin-2 的转录本从第 1 天到第 7 天显著下调。注射双链 RNA 后，Esserpin-2 的转录本从 48 小时到 96 小时急剧下降。沉默 Esserpin-2 后发现 proPO 的转录本明显增加，同时 LGBP 没有明显差异。沉默 Esserpin-2 组中 S. eriocheiris 的拷贝数和随后螃蟹的死亡率在感染期间明显低于对照组。亚细胞定位实验表明重组 Esserpin-2主要位于细胞质中。最后，在果蝇 S2 细胞中的过表达实验表明，Esserpin-2 可以增加 S. eriocheiris 的拷贝数并导致细胞死亡。这些发现表明，Esserpin-2 参与了中华绒螯蟹对 S. eriocheiris 感染的先天免疫机制。
