Department of Cardiology and Angiology I, Heart Center Freiburg University, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
Baker IDI Heart and Diabetes Institute, Melbourne, Australia.
PLoS One. 2019 Oct 23;14(10):e0224181. doi: 10.1371/journal.pone.0224181. eCollection 2019.
Platelets are key components in atherogenesis and determine the course of its clinical sequelae acute coronary syndrome (ACS). Components of the innate immune system-the superfamily of TLR receptors-are present in platelets and represent a link between atherothrombosis and inflammation. We hypothesize that alteration in platelet TLR mRNA expression is a result of inflammation driving coronary atherosclerosis and may represent an alternative platelet activation pathway in ACS. TLR2-, TLR4- and TLR9- mRNA-expression was determined in ACS patients and compared to patients with invasive exclusion of atherosclerotic lesions of coronary arteries.
A total of fifty-four patients were enrolled in this clinical retrospective cohort single centre study. Total RNA from sepharose-filtered highly purified platelets was isolated using acid guanidinium thiocyanate-phenol-chloroform extraction and transcribed to cDNA using a first strand cDNA synthesis kit. To determine absolute copy numbers of TLR2, TLR4 and TLR9 we used plasmid based quantitative PCR with normalisation to an internal control.
We found that mRNA expression levels of TLR2 but not TLR 4 and 9 are up-regulated in platelets of patients with ACS when compared to patients without coronary atherosclerosis.
Our results suggest elevated TLR2 mRNA expression in platelets as a biomarker reflecting the underlying inflammation in ACS and possibly severity of coronary atherosclerosis. Platelet TLR2 may represent a link between inflammation and atherothrombosis in ACS.
血小板是动脉粥样硬化形成过程中的关键成分，决定了其临床后果急性冠状动脉综合征（ACS）的进程。先天免疫系统的组成部分——TLR 受体超家族存在于血小板中，是动脉粥样硬化血栓形成和炎症之间的联系。我们假设血小板 TLR mRNA 表达的改变是炎症驱动冠状动脉粥样硬化的结果，并且可能代表 ACS 中血小板激活的另一种途径。在 ACS 患者中测定 TLR2、TLR4 和 TLR9-mRNA 表达，并与经血管内检查排除冠状动脉粥样硬化病变的患者进行比较。
这项临床回顾性队列单中心研究共纳入了 54 名患者。使用酸胍硫氰酸盐-酚-氯仿提取法从 sepharose 过滤的高度纯化血小板中分离总 RNA，并使用第一链 cDNA 合成试剂盒将其转录为 cDNA。使用基于质粒的定量 PCR 并以内参进行标准化，以确定 TLR2、TLR4 和 TLR9 的绝对拷贝数。
我们发现，与无冠状动脉粥样硬化的患者相比，ACS 患者的血小板中 TLR2 的 mRNA 表达水平上调，但 TLR4 和 TLR9 则不然。
我们的结果表明，血小板中 TLR2 mRNA 表达的升高可作为反映 ACS 中潜在炎症的生物标志物，并且可能与冠状动脉粥样硬化的严重程度有关。血小板 TLR2 可能代表 ACS 中炎症与动脉粥样硬化血栓形成之间的联系。
