title: EphB2 contributes to human naive B-cell activation and is regulated by miR-185.
abstract: EphB2 is an important member of the receptor tyrosine kinases. Recently, EphB2 was shown to facilitate T-cell migration and monocyte activation. However, the effects of EphB2 on B cells remain unknown. In this study, the expression of EphB2 on B cells was tested by Western blot, and the roles of EphB2 in B-cell proliferation, cytokine secretion, and immunoglobulin (Ig) production were evaluated using EphB2 siRNA interference in human B cells from healthy volunteers. Our study revealed that EphB2 was distributed on naive B cells and was up-regulated on activated B cells. Moreover, B-cell proliferation (decreased by 22%, P<0.05), TNF-α secretion (decreased by 40%, P<0.01) and IgG production (decreased by 26%, P < 0.05) were depressed concordantly with the down-regulated EphB2 expression. Subsequently, we screened microRNAs that could regulate EphB2 expression in B cells, and discovered that miR-185 directly targeted to EphB2 mRNA and suppressed its expression. Furthermore, miR-185 overexpression inhibited B-cell activation, and the inhibitor of miR-185 enhanced B-cell activation. Moreover, abatement of EphB2 through miR-185 mimics or EphB2 siRNA attenuated the activation of Src-p65 and Notch1 signaling pathways in human B cells. Our study first suggested that EphB2 was involved in human naive B cell activation through Src-p65 and Notch1 signaling pathways and could be regulated by miR-185.
authors.affiliation: Laboratory of Cardiovascular Immunology, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Miao
authors.initials: M
authors.lastname: Yu
authors.affiliation: Laboratory of Cardiovascular Immunology, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liang
authors.affiliation: Laboratory of Cardiovascular Immunology, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Wen
authors.affiliation: Laboratory of Cardiovascular Immunology, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Tong
authors.initials: T
authors.lastname: Zhao
authors.affiliation: Laboratory of Cardiovascular Immunology, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Ming-Xin
authors.initials: MX
authors.lastname: Zhu
authors.affiliation: Laboratory of Cardiovascular Immunology, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Huan-Huan
authors.initials: HH
authors.lastname: Li
authors.affiliation: Laboratory of Cardiovascular Immunology, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Long
authors.affiliation: Laboratory of Cardiovascular Immunology, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.affiliation: Laboratory of Cardiovascular Immunology, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Cheng
authors.affiliation: Laboratory of Cardiovascular Immunology, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China yhelen13@163.com liaoyh27@126.com.
authors.forename: Yu-Hua
authors.initials: YH
authors.lastname: Liao
authors.affiliation: Laboratory of Cardiovascular Immunology, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China yhelen13@163.com liaoyh27@126.com.
authors.forename: Jing
authors.initials: J
authors.lastname: Yuan
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology*; D036387:Ephrin-B1 / Q000096:biosynthesis / Q000235:genetics; D036388:Ephrin-B2 / Q000096:biosynthesis / Q000235:genetics; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000502:physiology*; D035683:MicroRNAs / Q000502:physiology*; D034622:RNA Interference; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D034741:RNA, Small Interfering / Q000494:pharmacology; D036183:Receptor, EphB2 / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D051881:Receptor, Notch1 / Q000502:physiology; D015398:Signal Transduction; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D036387:Ephrin-B1; D036388:Ephrin-B2; D007074:Immunoglobulin G; D007075:Immunoglobulin M; C552431:MIRN185 microRNA, human; D035683:MicroRNAs; C497761:NOTCH1 protein, human; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D051881:Receptor, Notch1; D014409:Tumor Necrosis Factor-alpha; C586310:EPHB2 protein, human; D036183:Receptor, EphB2
keywords: Notch1; microRNA; tyrosine kinases