病毒性心肌炎小鼠心肌颗粒酶B的表达及清心胶囊的干预作用

Expression of Granzyme B in Myocardium of Mice with Viral Myocarditis and Intervention Effect of Qingxin Capsule on it

目的:探讨颗粒酶B对病毒性心肌炎(VMC)心肌病变的影响,进一步阐明VMC的发病机理和清心胶囊治疗VMC的作用机制。方法:将62只5～6周龄雄性BALB/c小鼠随机分成3组:正常组10只,模型组和治疗组各26只。于第11天处死小鼠取出心脏观察心肌病变,并以半定量RT-PCR和免疫组化方法检测心肌颗粒酶B的表达。结果:模型组和治疗组小鼠心肌组织中均检测到颗粒酶BmRNA的表达,且模型组表达明显高于治疗组,两组中颗粒酶B阳性细胞数分别为2.7333±3.1043、0.8000±0.9487个/高倍视野(P<0.01);正常组心肌中未检测到颗粒酶B的表达。结论:心肌浸润细胞中颗粒酶B的表达可能在病毒性心肌炎心肌损伤中起一定作用;清心胶囊对CVB3病毒性心肌炎的治疗机理,还可能与其能够抑制活化的CTL和NK细胞中颗粒酶B的表达,减轻炎症反应的损伤作用有关。

Objective:To explore effect of expression of granzyem B(GzmB) in infiltrating myocardial cells of mice with viral myocarditis(VMC) induced by coxsackievirus B_3(CVB_3) on the injury of myocardium and intervening action of Qingxin capsule on it,and further to elucidate the pathogenesis of VMC and action mechanism of treatment of Qingxin capsule for VMC.Methods:Sixty-two BALBc male mice,5 to 6 weeks old,were randomly divided into three groups:the normal group,10;the model one,26;and the treated one,26.on the eleventh day all mice were killed and the hearts were taken out for inspection whether there were pathological changes in the myocardium by macroscopy and microscopy.The expression of GzmB was detected in myocardium with immunohistochemistry and hemi-quantitive reverse transcript-polymerase chain reaction(RT-PCR).Results:(1)GzmB positive cells in myocardium detected by immunohistochemistry were significantly more in the model group than those in the treated group,and the number of positive cells of GzmB in the former and the latter was 2.7333±3.1043 and 0.8000±0.9487 per highpower field(HP) respectively(P<0.01),however,no such cells were discovered in the normal murine hearts.(2)Test of RT-PCR showed markedly higher expression of GzmB mRNA in mice myocardium of the model group compared with the treated group,however,no expression of GzmB mRNA in the normal group.Conclusions:(1)The expression of GzmB in the infiltrating myocardiocytes probably plays some role in the injury of myocardium;(2)The action mechanism of treatment of Qingxin capsule for CVB_3-induced viral myocarditis also possibly is associated with its capability of suppressing the expression of GzmB in the cytoplasm of cytetoxic T lymphocytes(CTLs) and natural killer(NK) cells,which can relieve the inflammatory injury to myocardium.