A novel role for endoplasmic reticulum protein 46 (ERp46) in platelet function and arterial thrombosis in mice.
A novel role for endoplasmic reticulum protein 46 (ERp46) in platelet function and arterial thrombosis in mice.
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DOI：
10.1182/blood.2021012055
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发表时间：
2021-11
期刊：
影响因子：
20.3
通讯作者：
Junsong Zhou;Yi Wu;L. Rauova;Gavin Koma;Lu Wang;M. Poncz;Hong Li;Tong Liu;K. Fong;J. Bennett;S. Kunapuli;D. Essex
中科院分区：
文献类型：
--
作者：
Junsong Zhou;Yi Wu;L. Rauova;Gavin Koma;Lu Wang;M. Poncz;Hong Li;Tong Liu;K. Fong;J. Bennett;S. Kunapuli;D. Essex
尽管蛋白质二硫键异构酶（PDI）家族的几个成员支持血栓形成，但其他具有CXYC基序的PDI家族成员仍未研究。ERp 46具有三个CGHC氧化还原活性位点和与其他PDI完全不同的分子结构。血小板表面ERp 46的表达随凝血酶刺激而增加。抗ERp 46抗体抑制血小板聚集、ATP释放和αIIbβ3活化。ERp 46蛋白增强αIIbβ3活化、血小板聚集和ATP释放，而失活的ERp 46抑制这些过程。ERp 46基因敲除小鼠尾部出血时间延长，并且通过输注ERp 46挽救的血栓形成模型中血小板聚集减少。ERp 46缺陷的血小板αIIbβ3活化、血小板聚集、ATP释放和P-选择素表达降低。这些缺陷被野生型ERp 46逆转，并且被含有三个活性位点中的任何一个的ERp 46部分逆转。抗ERp 46抗体可抑制αIIbβ3激活肽刺激的血小板聚集，并且在ERp 46缺陷型血小板中降低。ERp 46通过表面等离子体共振与αIIbβ3紧密结合，但与缺乏αIIbβ3的血小板结合较差，并且在血小板活化时与αIIbβ3物理结合。ERp 46介导凝块收缩和血小板扩散。ERp 46比其他PDI更强烈地还原β3亚基中的二硫键，并且与PDI相反，在β3中独立于纤维蛋白原产生巯基。ERp 46切割β3中的Cys 473-Cys 503二硫键，暗示ERp 46的靶点。最后，ERp 46缺陷型血小板β3中的巯基减少，这意味着ERp 46切割血小板中的二硫键。总之，ERp 46对血小板功能和血栓形成至关重要，并通过靶向二硫键促进αIIbβ3活化。
Although several members of protein disulfide isomerase (PDI) family support thrombosis, other PDI family members with the CXYC motif remain uninvestigated. ERp46 has three CGHC redox-active sites and a radically different molecular architecture than other PDIs. Expression of ERp46 on the platelet surface increased with thrombin stimulation. An anti-ERp46 antibody inhibited platelet aggregation, ATP release, and αIIbβ3 activation. ERp46 protein potentiated αIIbβ3 activation, platelet aggregation and ATP release, while inactive ERp46 inhibited these processes. ERp46-knockout mice had prolonged tail-bleeding times, and decreased platelet accumulation in thrombosis models that was rescued by infusion of ERp46. ERp46-deficient platelets had decreased αIIbβ3 activation, platelet aggregation, ATP release and P-selectin expression. The defects were reversed by wild-type ERp46 and partially reversed by ERp46 containing any of the three active sites. Platelet aggregation stimulated by an αIIbβ3-activating peptide was inhibited by the anti-ERp46 antibody and was decreased in ERp46-deficient platelets. ERp46 bound tightly to αIIbβ3 by surface plasmon resonance but poorly to platelets lacking αIIbβ3, and physically associated with αIIbβ3 upon platelet activation. ERp46 mediated clot retraction and platelet spreading. ERp46 more strongly reduced disulfide bonds in the β3 subunit than other PDIs, and in contrast to PDI generated thiols in β3 independently of fibrinogen. ERp46 cleaved the Cys473-Cys503 disulfide bond in β3 implicating a target for ERp46. Finally, ERp46-deficient platelets have decreased thiols in β3 implying that ERp46 cleaves disulfide bonds in platelets. In conclusion, ERp46 is critical for platelet function and thrombosis and facilitates αIIbβ3 activation by targeting disulfide bonds.