Platelet activation by Streptococcus sanguinis is accompanied by MAP kinase phosphorylation
Platelet activation by Streptococcus sanguinis is accompanied by MAP kinase phosphorylation
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DOI：
10.3109/09537104.2012.661105
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发表时间：
2013-01-01
期刊：
影响因子：
3.3
通讯作者：
McNicol, Archibald
中科院分区：
文献类型：
--
作者：
Abdulrehman, Ahmed Y.;Jackson, Elke C. G.;McNicol, Archibald
人们对感染在动脉粥样硬化血栓形成中的作用越来越感兴趣。特别是，细菌，特别是口腔来源的细菌，已经显示出使用多种机制激活血小板。以往的研究表明，S。血吸虫菌株2017-78诱导血小板聚集，这需要vWF和IgG两者的存在。这种聚集伴随着几种信号蛋白的连续磷酸化/去磷酸化/再磷酸化。前两个阶段是血栓素依赖性的，而再磷酸化阶段是由α IIb β 3整联蛋白介导的。在这里，信号事件，特别是MAP激酶的潜在作用，与S。使用免疫印迹方法进一步检查了血吸虫菌株2017-78诱导的血小板活化。S.血吸虫菌株2017-78引起血小板MAP激酶Erk 2的三相磷酸化谱与其他磷蛋白相似。用阿司匹林或RGDS预处理不影响2017-78诱导的Erk 2磷酸化或去磷酸化，但都抑制了再磷酸化阶段。相比之下，2017-78诱导的血小板MAP激酶p38磷酸化水平保持在升高的水平，这不受阿司匹林的影响。同样，2017-78诱导的cPLA（2）磷酸化在聚集过程中保持高于基础水平。p38抑制剂SB 203580对S.血吸虫诱导的聚集对p38或cPLA的磷酸化没有影响（2）。因此，目前的研究表明，在用S. sanguinis菌株2017-78中，并且与Erk 2而不是p38在响应S.吸血鬼
There is increasing interest in the role of infections in atherothrombotic conditions. In particular, bacteria, notably those of oral origin, have been shown to activate platelets using a variety of mechanisms. Previous studies have shown that S. sanguinis strain 2017-78 induces platelet aggregation which requires the presence of both vWF and IgG. This aggregation is accompanied by the consecutive phosphorylation/desphosphorylation/rephosphorylation of several signalling proteins. The first two phases are thromboxane-dependent whereas the rephosphorylation phase is mediated by engagement of the alpha IIb beta 3 integrin. Here signalling events, specifically the potential role of MAP kinases, associated with S. sanguinis strain 2017-78-induced platelet activation have been further examined using an immunoblotting approach. The addition of S. sanguinis strain 2017-78 caused a similar triphasic phosphorylation profile of the platelet MAP kinase Erk2 to that seen with other phosphoproteins. Pretreatment with aspirin or RGDS did not affect 2017-78-induced Erk2 phosphorylation or desphosphorylation but both inhibited the rephosphorylation phase. In contrast the level of 2017-78-induced platelet MAP kinase p38 phosphorylation remained at an elevated level, and this was unaffected by aspirin. Similarly, 2017-78-induced cPLA(2) phosphorylation remained above basal levels during the aggregation process. The p38 inhibitor SB203580 inhibited S. sanguinis-induced aggregation with no effect on the phosphorylation of either p38 or cPLA(2). Thus the current study demonstrates the activation of both the Erk2 and p38 forms of MAP kinases, and of cPLA(2), in platelets stimulated with S. sanguinis strain 2017-78, and is consistent with a role for Erk2, but not for p38, in the cPLA(2) phosphorylation in response to S. sanguinis.