title: Anti-β2 glycoprotein I antibodies in complex with β2 glycoprotein I induce platelet activation via two receptors: apolipoprotein E receptor 2' and glycoprotein I bα.
abstract: Anti-β2 glycoprotein I (anti-β2GPI ) antibodies are important contributors to thrombosis, especially in patients with antiphospholipid syndrome (APS). However, the mechanism by which anti-β2GPI antibodies are involved in the pathogenesis of thrombosis is not fully understood. In this report, we investigated the role of anti- β2GPI antibodies in complexes with β2GPI as mediators of platelet activation, which can serve as a potential source contributing to thrombosis. We examined the involvement of the apolipoprotein E receptor 2' (apoER2') and glycoprotein I ba (GP I ba) in platelet activation induced by the anti-β2GPI /β2GPI complex. The interaction between the anti-β2GPI /β2GPI complex and platelets was examined using in vitro methods, in which the Fc portion of the antibody was immobilized using protein A coated onto a microtiter plate. Platelet activation was assessed by measuring GPII b/III a activation and P-selectin expression and thromboxane B2 production as well as p38 mitogen-activated protein kinase phosphorylation. Our results revealed that the anti-β2GPI /β2GPI complex was able to activate platelets, and this activation was inhibited by either the anti-GP I bα antibody or the apoER2' inhibitor. Results showed that the anti-β2GPI /β2GPI complex induced platelet activation via GPI ba and apoER2', which may then contribute to the prothrombotic tendency in APS patients.
authors.affiliation: Department of Laboratory Diagnosis, the Second Affiliated Hospital of Harbin Medical University, Harbin, 150086, China.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Laboratory Diagnosis, the Second Affiliated Hospital of Harbin Medical University, Harbin, 150086, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Gao
authors.affiliation: Department of Laboratory Diagnosis, the Second Affiliated Hospital of Harbin Medical University, Harbin, 150086, China.
authors.forename: Donghe
authors.initials: D
authors.lastname: Lu
authors.affiliation: Department of Laboratory Diagnosis, the Second Affiliated Hospital of Harbin Medical University, Harbin, 150086, China.
authors.forename: Na
authors.initials: N
authors.lastname: Sun
authors.affiliation: Department of Laboratory Diagnosis, the Second Affiliated Hospital of Harbin Medical University, Harbin, 150086, China.
authors.forename: Xiaoxue
authors.initials: X
authors.lastname: Yin
authors.affiliation: Department of Laboratory Diagnosis, the Second Affiliated Hospital of Harbin Medical University, Harbin, 150086, China.
authors.forename: Meili
authors.initials: M
authors.lastname: Jin
authors.affiliation: Department of Laboratory Diagnosis, the Second Affiliated Hospital of Harbin Medical University, Harbin, 150086, China. liuusa1964@yahoo.com.
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Liu
mesh_terms: D001323:Autoantibodies / Q000276:immunology*; D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006023:Glycoproteins / Q000502:physiology*; D006801:Humans; D007136:Immunoglobulins / Q000502:physiology*; D026502:LDL-Receptor Related Proteins / Q000502:physiology*; D015539:Platelet Activation / Q000502:physiology*; D053482:beta 2-Glycoprotein I / Q000276:immunology* / Q000502:physiology
chemical_list: C048566:A1BG protein, human; D001323:Autoantibodies; D006023:Glycoproteins; D007136:Immunoglobulins; D026502:LDL-Receptor Related Proteins; D053482:beta 2-Glycoprotein I; C098773:low density lipoprotein receptor-related protein 8
keywords: GPI bα; anti-β2GPI/β2GPI complex; apoER2′; platelet; thrombosis