Edwardsiella tarda-induced miR-7a functions as a suppressor in PI3K/AKT/GSK3β signaling pathway by targeting insulin receptor substrate-2 (IRS2a and IRS2b) in Paralichthys olivaceus. Issue 89 (June 2019)

• Record Type: Journal Article
• Authors: Liu, Yuezhong; Liu, Yuxiang; Han, Miao; Du, Xinxin; Liu, Xiumei; Zhang, Quanqi; Liu, Jinxiang
• Is Part Of: Fish & shellfish immunology. Issue 89(2019)
• Page Start: 477
• Page End: 485
• Publication Date: 2019-06
• Subjects: Paralichthys olivaceus -- Edwardsiella tarda -- High-throughput sequencing -- miR-7a -- IRS2 -- PI3K/AKT/GSK3β pathway; Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2019.03.076
• Languages: English
• ISSNs: 1050-4648

Abstract

Abstract: To study the effect of Edwardsiella tarda infection on miRNAs expression profile in Japanese flounder, fish were injected intraperitoneally with E. tarda . The miRNAs involved in regulating immune responses were analyzed by high-throughput sequencing. A total of 164 mature miRNAs were identified, of which 17 miRNAs were differentially expressed (DE miRNAs) after E. tarda infection, indicating that they were immune-related miRNAs. To further examine the relationship between the miRNAs and their predicted target mRNAs, a total of 22 predicted target mRNAs, mainly related to endocytic signaling pathway, NF- κ B signaling pathway, and p53 signaling pathway, were detected with miRNA mimics in HEK-293T cells by dual-luciferase reporter experiments. Finally, we confirmed that insulin receptor substrate-2 ( IRS2a and IRS2b ) were regulated by miR-7a. And the target sites of the 3' untranslated region (UTR) of IRS2a and IRS2b were verified by dual-luciferase reporter experiments. Furthermore, we found that the E. tarda and LPS significantly increased host miR-7a expression. In vivo and in vitro studies revealed that IRS2-mediated PI3K/AKT/GSK3β signaling pathway was suppressed. Taken together, these results implied that miR-7a might be a key regulator of PI3K/AKT/GSK3β signaling pathway via suppressing the IRS2a and IRS2b genes. Highlights: Totals of 164 mature miRNAs were identified from Paralichthys olivaceus liver. Seventeen miRNAs were differentially expressed post Edwardsiella tarda infection. IRS2a and IRS2b were target genes of miR-7a. miR-7a was maybe a new negative regulator of IRS2-mediated PI3K/AKT/GSK3β pathway.