Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, 04100, Latina (LT), Italy.
Department of Internal Medicine and Medical Specialties, Sapienza University of Rome, 00161, Rome (RM), Italy.
Sci Rep. 2017 Jun 19;7(1):3797. doi: 10.1038/s41598-017-03679-9.
Subjects carrying the C2238 variant of the atrial natriuretic peptide (ANP) gene have a higher occurrence of stroke and acute coronary syndrome, suggesting an increased predisposition to acute thrombotic events in these subjects. We evaluated for the first time the direct effects of mutant ANP (C2238/αANP) on platelet activation in vitro and in human subjects. In vitro, platelets were incubated with no peptide, with T2238/αANP (WT) or with C2238/αANP at different concentrations. C2238/αANP (10 M) induced higher collagen-induced platelet aggregation with respect to both control without ANP and T2238/αANP. This effect was even stronger at a higher concentration (10 M). Mechanistically, C2238/αANP significantly lowered platelet cAMP levels, increased ROS production and activated Nox2, with respect to both control and T2238/αANP. Forskolin, a cAMP activator, and sNOX2-tat, a Nox2 inhibitor, significantly reduced the pro-aggregant effects of C2238/αANP. In vivo, we found that platelet aggregation resulted to be higher in patients with atrial fibrillation carrying the C2238 ANP gene variant with respect to non-carriers. In conclusions, C2238/αANP promotes platelet aggregation through the activation of Nox2 and the reduction of cAMP.
携带心房利钠肽（ANP）基因 C2238 变异的受试者中风和急性冠状动脉综合征的发生率更高，这表明这些受试者发生急性血栓事件的倾向增加。我们首次评估了突变型 ANP（C2238/αANP）对体外和人体血小板激活的直接影响。在体外，将血小板与无肽、T2238/αANP（WT）或不同浓度的 C2238/αANP 孵育。与无 ANP 的对照和 T2238/αANP 相比，C2238/αANP（10 μM）诱导更高的胶原诱导的血小板聚集。在更高的浓度（10 μM）下，这种作用甚至更强。从机制上讲，与对照和 T2238/αANP 相比，C2238/αANP 显著降低血小板 cAMP 水平、增加 ROS 产生并激活 Nox2。cAMP 激活剂forskolin 和 Nox2 抑制剂 sNOX2-tat 显著降低了 C2238/αANP 的促聚集作用。在体内，我们发现携带心房颤动 C2238 ANP 基因变异的患者的血小板聚集明显高于非携带者。总之，C2238/αANP 通过激活 Nox2 和降低 cAMP 促进血小板聚集。
