Toll样受体3信号通路介导自身免疫性心肌炎炎症反应及作用机制

Inflammatory response mediated by Toll like receptor 3 in autoimmune myocarditis and its mechanism

目的探讨自身免疫性心肌炎大鼠心肌组织Toll样受体3(TLR3)表达水平及临床意义。方法将54只大鼠按照随机数字表法分为AM组、干预组和对照组,每组18只,对照组大鼠正常喂养,AM组、干预组建立自身免疫性心肌炎大鼠模型,干预组于模型建立第21天注射0.1 mg TLR3配体溶液,AM组、对照组大鼠注射等量PBS溶液。分别于模型建立第7、14、21、24、28、35天处死各组3只大鼠,观察各组大鼠心肌组织病理变化,酶联免疫吸附试验检测血清心肌肌凝蛋白自身抗体滴度,免疫组织化学染色法检测心肌组织TLR3蛋白表达,实时定量PCR检测心肌组织TLR3、TNF-αm RNA表达。结果对照组大鼠血清心肌肌凝蛋白自身抗体在不同时间点比较差异无统计学意义(P>0.05),干预组血清心肌肌凝蛋白自身抗体滴度在第28天达高峰,AM血清心肌肌凝蛋白自身抗体滴度在第21天达高峰;第14、21、24、28、35天AM组、干预组血清心肌肌凝蛋白自身抗体滴度显著高于对照组(P<0.05),第24、28、35天干预组血清心肌肌凝蛋白自身抗体滴度显著高于AM组(P<0.05)。对照组TLR3蛋白表达在不同时间点比较差异无统计学意义(P>0.05);第14、21、24、28、35天,AM组、干预组TLR3蛋白表达显著高于对照组(P<0.05),第24、28、35天,干预组TLR3蛋白表达显著高于AM组(P<0.05)。对照组TLR3、TNF-αm RNA相对表达量在不同时间点比较差异无统计学意义(P>0.05);第7、14、21、24、28、35天,AM组、干预组TLR3、TNF-αm RNA相对表达量显著高于对照组(P<0.05),第24、28、35天,干预组TLR3、TNF-αm RNA相对表达量显著高于AM组(P<0.05)。结论自身免疫性心肌炎心肌组织TLR3表达上调,TLR3信号通路介导的炎症反应参与了自身免疫性心肌炎的发病。

To explore the expression level and clinnical significance of Toll like receptor 3 and in myocardialtissue of autoimmune myocarditis rats, total of 54 rats, according to the random number table, were divided into AMgroup, intervention group and control group, with 18 rats in each group. Rats in control group were fed with normaldiet, while rats in AM and intervention group were all inducted to autoimmune myocarditis model. Rats inintervention group were injected with 0.1 mg TLR3 ligand on day 21 after model establishment, while AM group andcontrol group were given same amount of PBS solution. At days 7, 14, 21, 24, 28, 35 after model establishment, 3rats was killed in each group at every time point, and the pathological changes of myocardial tissue in rats of eachgroup were observed, serum myocardial myosin autoantibodies was detected by enzyme linked immunosorbent assay,TLR3 protein expression was detected by immunohistochemical staining, while TLR3, TNF-α m RNA expressionswere detected by real time quantitative PCR. Data showed that the serum myocardial myosin autoantibodies incontrol group rats showed no significant difference（P〉0.05） in different times; at day 28 after model establishment,the serum myocardial myosin autoantibodies titer reached the peak in intervention group, and at day 21 in AMgroup. At days 14, 21, 24, 28, and 35, serum myocardial myosin autoantibodies of AM group and intervention groupwere significantly higher than those in control group（P〈0.05）, and at days 24, 28 and 35, the serum myocardialmyosin autoantibodies in intervention group was significantly higher than that in AM group（P〈0.05）. TLR3 proteinexpression in control group rats at different times showed no significant difference（P〉0.05）; at days 14, 21, 24, 28,35, TLR3 protein expression of AM group andintervention group were significantly higher than that ofcontrol group（P〈0.05）. At days 24, 28, 35, TLR3 protein expression in intervention group was significantly higher than that in AM group（P〈0.05）. TLR3 and TNF-αm RNA expression in control group at different times showed no significant difference（P〉0.05）; at days 7, 14, 21, 24,28 and 35, TLR3 and TNF-α m RNA expression of AM group and intervention group were significantly higher thanthose in the control group（P〈0.05）. At days 24, 28 and 35, TLR3 and TNF-α m RNA expression in interventiongroup were significantly higher than those in AM group（P〈0.05）. In conclusion, TLR3 expression is up-regulated inthe myocardium of autoimmune myocarditis, and TLR3 signaling pathway-mediated inflammatory response isinvolved in the pathogenesis of autoimmune myocarditis.