title: An invertebrate-specific and immune-responsive microRNA augments oyster haemocyte phagocytosis by targeting CgIκB2.
abstract: Nuclear factor (NF)-κB pathway is an evolutionally conserved pathway in activating immune response, in which IκBs can repress the activation. In the present study, cgi-miR-2d, an invertebrate-specific microRNA, was proved to regulate CgIκB2 expression and haemocyte phagocytosis during bacterial infection in oyster Crassostrea gigas. The expression of cgi-miR-2d was significantly up-regulated after Vibrio splendidus challenge, while CgIκB2 transcripts decreased. Significant decreases in both luminescence and CgIκB2 3'UTR level was observed after transfection of cgi-miR-2d in CgIκB2 3'UTR luciferase reporter assay. CgIκB2 mRNA level decreased significantly (0.51-fold of control group, p < 0.05) in gain-of-function assay of cgi-miR-2d in vivo while it increased markedly (1.27-fold, p < 0.05) when cgi-miR-2d was repressed (0.10-fold, p < 0.01). A significant increase of haemocyte phagocytosis rate was observed in cgi-miR-2d overexpression group (p < 0.01), consistent with results in CgIκB2 knock-down group (p < 0.01). Moreover, the apoptosis rate of haemocytes was found significantly declined (28.57%, p < 0.01) in gain-of-function assay of cgi-miR-2d. Together, those results not only depicted the functional conservation of miR-2d family in anti-apoptosis of oysters but also highlighted its interaction with phagocytosis by modulating NF-κB pathway, which might dedicate critically to the well-balance of host immune response.
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Chen
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.affiliation: Key Laboratory of Mariculture &Stock enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian 116023, China.
authors.forename: Lingling
authors.initials: L
authors.lastname: Wang
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Weilin
authors.initials: W
authors.lastname: Wang
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Liu
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors.forename: Limei
authors.initials: L
authors.lastname: Qiu
authors.affiliation: Key Laboratory of Mariculture &Stock enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian 116023, China.
authors.forename: Linsheng
authors.initials: L
authors.lastname: Song
mesh_terms: D000818:Animals; D017209:Apoptosis; D049896:Crassostrea / Q000276:immunology* / Q000821:virology*; D006434:Hemocytes / Q000276:immunology*; D020672:I-kappa B Proteins / Q000378:metabolism*; D035683:MicroRNAs / Q000276:immunology*; D010587:Phagocytosis; D014733:Vibrio / Q000502:physiology*; D014735:Vibrio Infections
chemical_list: C083487:I kappa B beta protein; D020672:I-kappa B Proteins; D035683:MicroRNAs