MiR-155 is reported as immune regulated miRNA in mammalian corresponding to immunity, antibacterial and antiviral effects regulation. However, the roles and mechanisms of the miRNA have remained largely undefined. We herein comprehensively investigated the functions of miR-155 in vitro and in vivo by miR-155 mimics, agomir and antagomir in Cyprinus carpio and Ictalurus punctatus, with the target genes in the SOSC1 pathway certified in I. punctatus via luciferase reporter assays. Results showed that the miR-155 regulated the expressions of cytokines, including TNF-α, IFN-γ, IL-1β, IL-6 and IL-10. Further research confirmed SOSC1 as one of the targets of the miRNA, and the JAK1/STAT3/SOSC1 signal pathway involved in the miR-155 effects on the expression of immune cytokines as well. Additionally, the changes of TLR2 in fish may also be related to miR-155 along with its target SOCS1, and the TLR2/MyD88 pathway may partly participate in the effects of the miR-155 on the cytokines. The research here confirmed that the miR-155 can regulate cytokines expression by SOSC1 signal pathways of fish in vitro and in vivo, which would provide resources for understanding and studying about immune regulation in fish.

据报道，MiR-155是哺乳动物中免疫调节的miRNA，与免疫力，抗菌和抗病毒作用调节相对应。但是，miRNA的作用和机制在很大程度上还不确定。本文我们研究了全面的miR-155的功能在体外和体内受miR-155模拟物，在agomir和RNA拮抗剂鲤鱼和斑点叉尾鮰，在认证中SOSC1途径中的靶基因I.毛虫通过萤光素酶报告基因检测。结果表明，miR-155调节TNF-α，IFN-γ，IL-1β，IL-6和IL-10等细胞因子的表达。进一步的研究证实，SOSC1是miRNA的靶标之一，而miK-155涉及的JAK1 / STAT3 / SOSC1信号途径也对免疫细胞因子的表达产生影响。另外，鱼类中TLR2的变化也可能与miR-155及其目标SOCS1有关，并且TLR2 / MyD88途径可能部分参与miR-155对细胞因子的影响。此处的研究证实，miR-155可以通过鱼类体内外的SOSC1信号途径调节细胞因子的表达，这将为理解和研究鱼类的免疫调节提供资源。