Toll样受体2和4在大鼠心肌缺血/再灌注损伤模型中的动态表达  

Dynamic expression of Toll like receptor 2 and 4 in a rat model of myocardial ischemia/reperfusion injury*

作　　者：刘千萍[1] 潘坤颖[1] 周欣[1] 于海龙[1] 韩国亮[1] 李玉明[1] 姜铁民[1] 张梅[1] 

机构地区：[1]中国人民武装警察部队后勤学院附属医院,天津300162

出　　处：《中国应用生理学杂志》2013年第4期326-330,I0003,共6页Chinese Journal of Applied Physiology

摘　　要：目的:通过观察大鼠心肌组织缺血/再灌注(I/R)急性期Toll样受体2(TLR2)和4(TLR4)mRNA及蛋白质的表达,探讨TLR2和TLR4在心肌缺血/再灌注损伤中的作用。方法:雄性Wistar大鼠随机分为缺血/再灌注组(I/R组)和假手术组(sham组),建立大鼠心肌缺血/再灌注模型,按不同的再灌注时间(1、2、4、6、12、24 h和7 d)处死动物(n=42)。光镜下观察心肌组织形态改变。实时定量聚合酶链式反应(RT-PCR)定量心肌TLR2及TLR4mRNA水平。逆转录聚合酶链式反应(r-t PCR)测定心肌白介素-6(IL-6)和单核细胞趋化因子-1(MCP-1)的mRNA水平。结果:①随着再灌注时间的延长,心肌梗死面积逐渐增大,在再灌注4 h时达最大值,再灌注4 h、6 h、12 h、24 h,再灌注7 d已发生心室重塑。②在再灌注早期,sham组心肌组织形态未见明显改变,I/R组心肌结构有不同程度损伤,在复灌7 d时可见心室重塑,左室壁厚度明显变薄,大量成纤维细胞替代原有的心肌细胞。③sham组和I/R组TLR2、TLR4、MCP-1和IL-6mRNA水平均出现不同程度上调,其中TLR2和TLR4均在再灌注4 h时达高峰,随后逐渐下降,至再灌注7 d时TLR4水平再次升高。IL-6在6 h达到高峰后开始下降,到24 h时基本降至sham组水平,再灌注7 d时再次有升高趋势。MCP-1在缺血/再灌注后一直保持与sham组相当水平,在再灌注7 d时才有明显升高。结论:在心肌缺血/再灌注早期,心肌组织中TLR2和TLR4基因水平迅速上调,并促进下游炎症因子的产生造成心肌早期的损伤。在再灌注后期,TLR2和TLR4的再次升高使得炎症因子的表达再一次增加,从而影响心肌重塑,损伤心肌结构及功能。Objective： To explore the role of toll-like receptor 2（TLR2） and toll-like receptor 4（TLR4） in myocardial ischemia/reperfusion injury（MI/RI） by observing the dynamic expression changes at mRNA and protein levels early after myocardial ischemia/reperfusion（I/R）.Methods： The Wistar rats were randomly divided into Sham and I/R group（n=42）,and killed according to different reperfusion time（1,2,4,6,12,24 h and 7 d）.Structural and morphous changes of myocytes were observed under optical microscope.The mRNA and protein levels of TLR2 and TLR4 were detected using real-time PCR（RT-PCR）.Monocyte chemokine protein-1（MCP-1） and interleukine-6（IL-6） mRNA levels were measured by reverse transcriptase-polymerase chain reaction（rt-PCR）.Results： ① With the extension of reperfusion time,the myocardial infarct size increased smoothly,and reached the plateau at 4 h,then stayed in the platform.After reperfusion for 7 d,the ventricular had been remodeled.②At the beginning of reperfusion,myocardial structure showed no significant change in Sham group,but had different degrees of injury in I/R group.In rats of the group reperfused for 7 d the left ventricular remodeling could be visible.③Compared to sham group,TIR2,TLR4,MCP-1,IL-6 mRNA level were increased in myocardium in I/R group.TLR2 and TLR4 both peaked at 4 h of reperfusion,IL-6 peaked at 6 h,followed by a gradually decrease.TLR4 and IL-6 mRNA levels rose again at 7 d.MCP-1 level in I/R group remained fairly with sham group at the beginning of reperfusion,and markedly elevated at 7 d.Conclusion： Expression of TLRs mRNA in myocardium during early after myocardial ischemia/reperfusion increased rapidly and activated TLRs might play an important role in MI/RI through promoting the generation of inflammatory factors.At the late reperfusion,TLRs levels raise again and the expression of inflammatory factors increase once again,Those may probably affect the remodeling of ventricular,and injure myocardial structure and function.

关 键 词：心肌缺血 再灌注损伤 TOLL样受体2 TOLL样受体4 

分 类 号：R543.3[医药卫生—心血管疾病]