Yan Hui, Chen Yadong, Zhou Shun, Li Chao, Gong Guangye, Chen Xuejie, Wang Tianzi, Chen Songlin, Sha Zhenxia
Key Lab for Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, 106 Nanjing Road, Qingdao, 266071, People's Republic of China.
Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266200, People's Republic of China.
Mar Biotechnol (NY). 2016 Feb;18(1):37-48. doi: 10.1007/s10126-015-9668-2. Epub 2015 Sep 29.
Half-smooth tongue sole (Cynoglossus semilaevis) is an important marine commercial fish species in China, which suffers from widespread disease outbreaks. Recently, in this regard, our group identified immune-related microRNAs (miRNAs) of C. semilaevis following Vibrio anguillarum infection. Furthermore, miRNA microarray was utilized to characterize the immune roles of important miRNA candidates in response to bacterial infection. Therefore, in the present study, we characterized miR-221 and miR-222 and profiled their expression after challenge. Here, miR-221 and miR-222 precursors were predicted to have a typical hairpin structure. Both miRNAs were expressed in a broad range of tissues in C. semilaevis, while miR-221 and miR-222 were significantly differentially expressed in the immune tissues of C. semilaevis among three small RNA libraries [control group (CG), bacteria-challenged fish without obvious symptoms of infection (NOSG), and bacteria-challenged fish with obvious symptoms of infection (HOSG)]. In order to further characterize and understand the immune response of miR-221 and miR-222, therefore, we profiled miR-221 and miR-222 expression in selected immune tissues after challenge with V. anguillarum. Both miR-221 and miR-222 were upregulated in the liver and spleen, while different expression patterns were observed in the head kidney. In addition, in half-smooth tongue sole head kidney cell line after challenge with lipopolysaccharide (LPS), polyinosinic:polycytidylic acid (poly I:C), peptidoglycan (PGN), and red-spotted grouper nervous necrosis virus (RGNNV), both miR-221 and miR-222 showed significant difference in expression response to pathogen. Meanwhile, the target gene of miR-221 and miR-222 was predicted, which indicated that tumor necrosis factor receptor-associated factor 6 (TRAF6) and interleukin-1 beta (IL-1β) were the target genes of miR-221 and miR-222, respectively. Collectively, these findings indicated that miR-221 and miR-222 have putative roles in innate immune response during C. semilaevis exposure to pathogens. Our findings could expand the knowledge of immune function of C. semilaevis miRNA and guide future studies on C. semilaevis immunity.
半滑舌鳎（Cynoglossus semilaevis）是中国重要的海洋商业鱼类品种，它遭受广泛的疾病爆发。最近，在这方面，我们的团队鉴定了鳗弧菌感染后半滑舌鳎的免疫相关微小RNA（miRNA）。此外，利用miRNA微阵列来表征重要miRNA候选物在应对细菌感染中的免疫作用。因此，在本研究中，我们对miR-221和miR-222进行了表征，并分析了它们在受到攻击后的表达情况。在此，预测miR-221和miR-222前体具有典型的发夹结构。这两种miRNA在半滑舌鳎的广泛组织中都有表达，而在三个小RNA文库[对照组（CG）、未出现明显感染症状的细菌攻击鱼（NOSG）和出现明显感染症状的细菌攻击鱼（HOSG）]中的半滑舌鳎免疫组织中，miR-221和miR-222有显著差异表达。为了进一步表征和理解miR-221和miR-222的免疫反应，因此，我们分析了鳗弧菌攻击后选定免疫组织中miR-221和miR-222的表达。miR-221和miR-222在肝脏和脾脏中均上调，而在头肾中观察到不同的表达模式。此外，在用脂多糖（LPS）、聚肌苷酸：聚胞苷酸（poly I:C）、肽聚糖（PGN）和红斑石斑鱼神经坏死病毒（RGNNV）攻击后半滑舌鳎头肾细胞系中，miR-221和miR-222在对病原体的表达反应中均显示出显著差异。同时，预测了miR-221和miR-222的靶基因，这表明肿瘤坏死因子受体相关因子6（TRAF6）和白细胞介素-1β（IL-1β）分别是miR-221和miR-222的靶基因。总体而言，这些发现表明miR-221和miR-222在半滑舌鳎暴露于病原体期间的先天免疫反应中具有假定作用。我们的发现可以扩展对半滑舌鳎miRNA免疫功能的认识，并指导未来对半滑舌鳎免疫的研究。
