Cardiovascular Research Institute and Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang, China.
Cardiovascular Research Institute and Department of Cardiology, General Hospital of Shenyang Military Region, Shenyang, China.
Biochim Biophys Acta Mol Basis Dis. 2018 Sep;1864(9 Pt B):2901-2912. doi: 10.1016/j.bbadis.2018.05.025. Epub 2018 Jun 1.
Studies indicate that chemokine CC-motif ligand 2 (CCL2) is involved in inflammation and atherosclerosis. However, the roles and mechanisms of CCL2 on platelet function and arterial thrombosis are unknown.
The expressions of CCL2 or CCR2 in the plasma, platelets and coronary thrombus of ST-elevated myocardial infarction (STEMI) patients were examined by ELISA, Western blot, immunohistochemistry and immunofluorescence. The roles of CCL2 on platelet aggregation, activation and secretion were examined by light transmission aggregometry, flow cytometry and ELISA.
The expressions of CCL2 or CCR2 in the plasma or platelets of STEMI patients with platelet high response were higher than those with platelet normal response; In vitro, exogenous recombinant human CCL2 markedly increased platelet aggregation, activation and granule secretion, which were abolished by CCL2 neutralizing antibody or CCR2 inhibiter. CCL2 increased the phosphorylation levels of PKCα (Thr638), P38MAPK (Thr180/Tyr182) and HSP27 (S78/S82) in human platelets, which were abrogated by PKCα inhibitor (RO 318220) or P38MAPK inhibitor (SB 203580). RO 318220 or SB 203580 diminished CCL2-induced platelet function. In CCL2 mice, platelet aggregation and secretion were attenuated; the phosphorylation of PKCα, P38MAPK and HSP27 were decreased. In a carotid arterial thrombus mouse model, CCL2 mice displayed a significantly extended carotid artery occlusion time compared with wild type.
CCL2 played important roles in regulating platelet function and arterial thrombosis through the PKCα-P38MAPK-HSP27 pathway, which might provide theoretical basis for searching new antiplatelet drugs and the treatment for cardiovascular diseases.
研究表明趋化因子 CC 基元配体 2（CCL2）参与炎症和动脉粥样硬化。然而，CCL2 对血小板功能和动脉血栓形成的作用和机制尚不清楚。
通过 ELISA、Western blot、免疫组化和免疫荧光法检测 ST 段抬高型心肌梗死（STEMI）患者血浆、血小板和冠状动脉血栓中 CCL2 或 CCR2 的表达。通过透光比浊法、流式细胞术和 ELISA 检测 CCL2 对血小板聚集、活化和分泌的作用。
血小板高反应性 STEMI 患者的血浆或血小板中 CCL2 或 CCR2 的表达高于血小板正常反应性患者；体外，外源性重组人 CCL2 明显增加血小板聚集、活化和颗粒分泌，CCL2 中和抗体或 CCR2 抑制剂可消除这些作用。CCL2 增加人血小板中 PKCα（Thr638）、P38MAPK（Thr180/Tyr182）和 HSP27（S78/S82）的磷酸化水平，PKCα 抑制剂（RO 318220）或 P38MAPK 抑制剂（SB 203580）可消除这些作用。RO 318220 或 SB 203580 可减弱 CCL2 诱导的血小板功能。在 CCL2 小鼠中，血小板聚集和分泌减弱；PKCα、P38MAPK 和 HSP27 的磷酸化减少。在颈动脉血栓形成小鼠模型中，与野生型相比，CCL2 小鼠的颈动脉闭塞时间明显延长。
CCL2 通过 PKCα-P38MAPK-HSP27 通路在调节血小板功能和动脉血栓形成中发挥重要作用，为寻找新的抗血小板药物和治疗心血管疾病提供了理论依据。
