Functional role of a polymorphism in the Pannexin1 gene in collagen-induced platelet aggregation
Functional role of a polymorphism in the Pannexin1 gene in collagen-induced platelet aggregation
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DOI：
10.1160/th14-11-0981
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发表时间：
2015-08-01
影响因子：
6.7
通讯作者：
Kwak, Brenda R.
中科院分区：
文献类型：
--
作者：
Molica, Filippo;Morel, Sandrine;Kwak, Brenda R.
Pannexin1 (Panx1) 形成 ATP 通道，通过增强免疫突触中的嘌呤能信号放大，在免疫反应中发挥关键作用。血小板表达 Panx1，鉴于血小板中 ATP 释放的重要性，我们研究了 Panx1 在血小板聚集中的功能以及遗传多态性对 Panx1 通道的潜在影响。我们在此表明 Panx1 在人血小板中形成 ATP 释放通道，并且用丙磺舒、甲氟喹或特定 (10)Panx1 肽抑制 Panx1 通道功能可减少胶原诱导的血小板聚集，但不会减少花生四烯酸或 ADP 诱导的反应。使用 Panx(1-/-) 血小板证实了这些结果。人类 Panx1 基因中已经描述了自然变异，预计这些变异会在其编码序列中诱导非保守氨基酸取代。与具有 Panx1-400A 等位基因的健康受试者相比，Panx1-400C 纯合子的健康受试者表现出增强的血小板对胶原蛋白的反应性。相反，与血小板反应低的患者相比，血小板反应高的心血管患者中 Panx1-400C 纯合子的频率增加。多态性 Panx1 通道在 Panx 缺陷细胞系中的外源表达表明，与表达 Panx1-400A 的转染子相比，转染 Panx1-400C 通道的细胞的基础和刺激 ATP 释放增加。总之，我们证明了 Panx1 通道在导致胶原诱导血小板聚集的信号通路中的特定作用。我们的研究首次进一步确定了 Panx1-400A>C 基因多态性与胶原诱导的血小板反应性之间的关联。 Panx1-400C 变体编码功能获得通道，该通道可能通过特异性增强胶原蛋白诱导的 ATP 释放和血小板聚集而对动脉粥样硬化血栓形成产生不利影响。
Pannexin1 (Panx1) forms ATP channels that play a critical role in the immune response by reinforcing purinergic signal amplification in the immune synapse. Platelets express Panx1 and given the importance of ATP release in platelets, we investigated Panx1 function in platelet aggregation and the potential impact of genetic polymorphisms on Panx1 channels. We show here that Panx1 forms ATP release channels in human platelets and that inhibiting Panx1 channel function with probenecid, mefloquine or specific (10)Panx1 peptides reduces collagen-induced platelet aggregation but not the response induced by arachidonic acid or ADP. These results were confirmed using Panx(1-/-) platelets. Natural variations have been described in the human Panx1 gene, which are predicted to induce non-conservative amino acid substitutions in its coding sequence. Healthy subjects homozygous for Panx1-400C, display enhanced platelet reactivity in response to collagen compared with those bearing the Panx1-400A allele. Conversely, the frequency of Panx1-400C homozygotes was increased among cardiovascular patients with hyper-reactive platelets compared with patients with hypo-reactive platelets. Exogenous expression of polymorphic Panx1 channels in a Panx-deficient cell line revealed increased basal and stimulated ATP release from cells transfected with Panx1-400C channels compared with Panx1-400A expressing transfectants. In conclusion, we demonstrate a specific role for Panx1 channels in the signalling pathway leading to collagen-induced platelet aggregation. Our study further identifies for the first time an association between a Panx1-400A>C genetic polymorphism and collagen-induced platelet reactivity. The Panx1-400C variant encodes for a gain-of-function channel that may adversely affect atherothrombosis by specifically enhancing collagen-induced ATP release and platelet aggregation.