巨噬细胞移动抑制因子在病毒性心肌炎小鼠心肌中的表达

Expression of macrophage migration inhibitory factor in myocardial tissue of mice with viral myocarditis

目的探讨病毒性心肌炎(VMC)发病过程中心肌组织巨噬细胞移动抑制因子(MIF)表达的动态变化及意义。方法70只4周龄雄性BALB/C小鼠腹腔接种0.1ml的coxasckievirusB3(CVB3)建立VMC模型,10只同周龄同品系小鼠腹腔接种Eagle’s液作为对照组。VMC组于接种后第3、7、15、30天随机各取10只处死,对照组于30天处死,采用RT-PCR、免疫组化检测心肌MIFmRNA及蛋白表达,并对MIF表达水平与心肌病变积分进行相关性分析。结果VMC组3～30d各时点心肌MIFmRNA及蛋白表达水平均明显增高,以第7天为最高,与对照组比较,差异均有统计学意义(P<0.05,<0.01),MIF蛋白表达水平与心肌病变积分呈显著正相关(r=0.90,P<0.05)。结论MIF过度表达可能在VMC的发病机制中起重要作用。

Objectives To investigate the dynamic changes and significance of macrophage migration inhibitory factor （MIF） expression in murine myocardial tissues with viral myocarditis （VMC） . Methods Eighty 4-week-old male BALB/C mice were randomly divided into two groups. Mice in the VMC group （n = 70） were inoculated intraperitoneally with 0.1 ml coxasckievirus B3 （CVB3）. Control mice （n = 10） were treated with 0.1 ml of Eagle＇s solution. Ten infected mice were sacrificed on Days 3, 7, 15 and 30 after inoculation while the control mice were sacrificed on Day 30 post-inoculation.The mRNA and protein expression of myocardial MIF was determined by RT-PCR and immunohistochemistry. In addition, the relationship between MIF expression and myocardial histopathological scores were analyzed. Results Compared with the control group, the mRNA and protein expression of myocardial MIF on Day 3 to 30 in VMC group increased and reached the peak on Day 7 after virus inoculation （P 〈 0.05 or 0.01）. Furthermore, significantly positive correlation was found between the protein expression level of MIF and myocardial histopathologic scores （r = 0.90, P 〈 0.05）. Conclusions Over-expression of MIF may play a critical role in the pathogenesis of viral myocarditis.