木瓜蛋白酶对MPA形成及其诱导的单核细胞活化的影响

Effects of papain on monocyte-platelet aggregates formation and monocyte activation induced by monocyte-platelet aggregates

目的:观察木瓜蛋白酶对单核细胞-血小板聚集物(MPA)形成及其诱导的单核细胞活化的抑制作用,并初步探讨其作用机制。方法:分离单核细胞和富血小板血浆(PRP),将实验分为3组:0、20、80U/L木瓜蛋白酶组,分别测定不同浓度木瓜蛋白酶与单核细胞和血小板(PLT)共孵育后以及木瓜蛋白酶与血小板单独孵育后MPA形成、P-选择素和CD11b表达水平,木瓜蛋白酶与单核细胞孵育后的MPA形成和CD11b表达水平,计算各浓度木瓜蛋白酶对MPA和CD11b的抑制率。结果:随药物浓度增加,木瓜蛋白酶与单核和PLT共孵育后以及木瓜蛋白酶与血小板单独孵育后MPA形成、P-选择素和CD11b表达水平显著降低,木瓜蛋白酶与单核细胞单独孵育后MPA形成和CD11b表达水平显著降低,差异均有统计学意义(P<0.01或0.001)。各处理组中,80U/L组对MPA和CD11b的抑制率均显著高于20U/L组(P<0.01),木瓜蛋白酶与血小板和单核细胞共孵育组MPA和CD11b抑制率均显著高于其余两组,差异均有统计学意义(P<0.001)。结论:木瓜蛋白酶可通过抑制血小板P-选择素表达和单核细胞与血小板结合途径而对MPA形成及其诱导的单核细胞活化有抑制作用,这可能作为其可应用于抗血栓和动脉粥样硬化防治的新机制。

AIM：To observe the effects of papain on monocyte-platelet aggregates（MPA）formation and monocyte activation induced by MPA,and to explore the primary mechanism.METHODS：Monocytes and platelet rich plasma（PRP）were separated from peripheral blood of volunteers. This study was assigned three groups：group 0U/L,20U/L and 80U/L of papain.Expression levels of MPA,P-selectin and CD11 bafter monocyte and platelet co-incubated with different concentration of papain aswell as after only platelet incubated with papain,and expression levels of MPA and CD11 bafter only monocyte incubated with papain were measured in different groups.The inhibitory rates of MPA and CD11 bexpression in different concentration of papain were calculated.RESULTS：With papain concentration increasing,MPA,Pselectin and CD11 bexpression levels were significantly decreased after monocyte and platelet coincubation with papain as well as after only platelet incubation with papain（P〈0.01）;and MPA and CD11 bexpression levels were remarkably decreased,too（P〈0.01）.From the different treatment groups,the inhibitory rates of MPA and CD11 bof group 80U/L were notably higher than that of group 20U/L（P〈0.001）.From the group of monocyte and platelet co-incubated with papain,the inhibitory rates of MPA and CD11 bwere markedly higher than that of other treatment groups（P〈0.01）.CONCLUSION：Papain is able to inhibit monocyte-platelet aggregate formation and monocyte activation induced by MPA mainly through inhibition of platelet p-selectin expression and monocyteplatelet interaction,which may be a new mechanism underlying the anti-thrombosis and antisclerosis effects of papain.