TOLL样受体2在大鼠肺移植缺血再灌注损伤期的时序性表达及意义

Dynamic TLR2 Expression and Its Significance in Lung Ischemia/Reperfusion Injury after Transplantation in Rats

目的探讨大鼠肺移植术后早期移植肺中Toll样受体2(TLR2)的表达情况及其意义。方法三套管法建立大鼠左肺原位移植模型,应用实时荧光定量逆转录多聚酶链反应动态观察TLR2 mRNA在移植肺中的表达水平,采用免疫印迹技术和免疫组织化学技术检测TLR2蛋白的表达,同时用ELISA法检测肺组织中TNF-α和IL-8的表达变化。结果左肺原位移植术后,再灌注4 h即有TLR2 mRNA表达上调趋势,但与对照组比较差异无统计学意义(P>0.05)。再灌注12 h和24 h组TLR2 mRNA表达量达峰值,明显高于对照组(P<0.01)。再灌注48 h组TLR2 mRNA表达量下调,与对照组比较差异无统计学意义(P>0.05)。TLR2蛋白在再灌注12 h和24 h组呈高表达(P<0.01)。免疫组织化学染色显示阳性细胞主要是肺泡上皮细胞和肺泡巨噬细胞。TNF-α和IL-8在移植肺各时间点均高表达(P<0.05),在12 h至24 h细胞因子含量达高峰。结论 TLR2 mRNA和蛋白在大鼠左肺原位移植术后缺血再灌注损伤期表达上调,参与肺移植术后缺血再灌注损伤的病理生理过程。

Objective To explore the Toll-like receptor 2（TLR2）expression in the graft after lung transplantation in rats and its significance.Methods Rat orthotopic lung transplantation model was established by cuff technique.The expression of TLR2 mRNA was detected quantitatively by using real-time RT-PCR,and that of TLR2 protein by Western blot and immunohistochemistry.The protein expression changes of TNF-α and IL-8 in the graft were examined by using ELISA.Results At the 4th h after reperfusion,the expression of TLR2 mRNA and protein had an up-regulated tendency in lung tissue as compared with control groups（P0.05）.At the 12th-24th h after reperfusion,the expression of TLR2 mRNA reached the peak,significantly higher than in control groups（P0.01）.The expression of TLR2 protein at the 12th to 24th h after reperfusion was up-regulated（P0.01）.Immunohistochemistry showed that TLR2 protein was mostly expressed in alveolar epithelial cells and macrophages.The expression of TNF-α and IL-8 was up-regulated from the 4th to 48th h（P0.05）,and reached the peak at the 12th to 24th h after reperfusion.Conclusion There is intensive expression of TLR2 in the graft soon after lung allograft reperfusion,suggesting TLR-2 may participate in the pathophysiology of lung ischemia/reperfusion injury after lung transplantation.