普伐他汀和CRP对ADP诱导的血小板凝血酶受体 PAR-1表达的调节

目的：探讨普伐他汀对二磷酸腺苷（ADP）诱导的血小板PAR‐1表达的影响及机制。方法体外分离富血小板血浆，分别给予C反应蛋白（CRP）、普伐他汀干预和ADP刺激进行体外研究。试验分组分别为：对照组，单纯ADP组，低浓度普代他汀＋ADP组，高浓度普伐他汀组＋ADP组，CRP组，普伐他汀＋CRP联合组。采用流式细技术检测PAR‐1和LOX‐1平均荧光强度（M FI）。采用酶联免疫试验检测TXB2和F1＋2水平。结果5μmol／L ADP刺激能促使血小板PAR‐1表达增加35％。50μg／mL CRP显著降低ADP诱导的血小板PAR‐1的表达（P＜0．01）。1μmol／L、10μmol／L普伐他汀均显著降低ADP诱导的血小板PAR‐1的表达（P＜0．01）。联合应用CRP和普伐他汀更能降低ADP诱导的血小板PAR‐1表达，较单独使用CRP或普伐他汀降低更显著（P＜0．05）。单纯ADP刺激后TXB2较基础时明显增高（P＜0．01），50μg／mL CRP、10μmol／L普伐他汀干预后ADP刺激的TXB2分别下降为（112．68±24．48）pg／mL、（146．48±46．54）pg／mL ，与单纯ADP刺激比较，差异均有统计学意义（P＜0．01）。50μg／mL CRP显著增加ADP诱导的F1＋2水平（P＜0．01），10μmol／L普伐他汀对ADP诱导F1＋2的生成无明显影响。普伐他汀呈浓度依赖性的方式降低ADP诱导的血小板LOX‐1表达（1μmol／L和10μmol／L普伐他汀处理后M FI分别为：1．80±0．19和1．62±0．16），与单纯ADP刺激后LOX‐1表达（MFI：3．16±0．23）比较，差异有统计学意义（P＜0．01）。50μg／mL CRP对ADP刺激的血小板LOX‐1表达无明显影响。结论 PAR‐1在ADP诱导的血小板活化中起重要作用，普伐他汀和CRP通过不同机制明显降低ADP诱导的血小板PAR‐1的表达，提示在炎症状态下他汀仍能起着重要的抗血栓作用。

Modulation of PAR-1 expression by pravastatin and C reactive protein in vitro blood platelets

Objective To study the modulation of protease‐activated receptor‐1 (PAR‐1) expression by pravastatin and C re‐active protein(CRP) in vitro blood platelets .Methods Platelet‐rich plasma (PRP) was isolated from peripheral blood ,PRP were treated with CRP ,pravastatin and ADP stimulation in vitro study .Experimental groups:blank control group ,simple ADP stimulated group ,low concentration of pravastatin+ADP group ,high concentration pravastatin group+ ADP group ,CRP group ,pravastatin+CRP united group .PAR‐1 and LOX‐1 expression on platelets were detected by flow cytometry ,the result were shown by mean fluo‐rescence intensity (MFI) .TXB2 and F1+2 levels were detected by enzyme‐linked immunosorbent assay .Results The 5 μmol/L ADP stimulation significantly increased PAR‐1 expression on platelets by 35% .The 50 μg/mL CRP significantly reduced platelet PAR‐1 expression induced by ADP(P<0 .01) .1 ,10 μmol/L pravastatin significantly reduced platelet PAR‐1 expression induced by ADP(P<0 .01) .Platelet PAR‐1 expression induced by ADP was further reduction by combination treatment of CRP ,which were significantly reduced compared with treatment of CRP or pravastatin alone(P< 0 .05) .Simple ADP stimulation significantly in‐creased TXB2 level(P< 0 .01) .50 μg/mL CRP and 10 μmol/L pravastatin respectively reduced TXB2 level treated by ADP to (112 .68 ± 24 .48)pg/mL and (146 .48 ± 46 .54)pg/mL .Both were reduced significantly compared with ADP stimulation alone(P<0 .01) .The 50 μg/mL CRP significantly increased level of prothrombin fragment 1+ 2 induced by ADP(P< 0 .01) ,10 μmol/L pravastatin ,in contrast ,did not influence F1+2 level .Pravastatin reduced platelet LOX‐1 expression induced by ADP in a concen‐tration dependent manner ,MFI of LOX‐1 on platelets treated by 1μmol/L and 10μmol/L pravastatin were 1 .80 ± 0 .19 and 1 .62 ± 0 .16 respectively ,both were reduced significantly compared with that treated by ADP alone(MFI:3 .16 ± 0 .23) ,P<0 .01 .The 50μg/mL CRP had no significant effect on the expression of LOX‐1 stimulated by ADP .Conclusion PAR‐1 served as a critical mech‐anism to relay the platelet activation process induced by ADP .CRP and pravastatin reduced PAR‐1 expression in platelet induced by ADP in different way .It is suggested that statins can still play an important role in the antithrombotic effect in the inflammatory state .