才开·莎热丽　徐思成　李超

[摘要] 目的 探讨大鼠肺缺血再灌注损伤（IRI）模型中Toll样受体4（TLR4）信号通路介导缺氧诱导因子-1α（HIF-1α）的变化及其意义。 方法 选取48只健康雄性SD大鼠，采用随机数字表法分为假手术组、IRI模型组、TLR4激活组（脂多糖干预）、TLR4抑制组（TAK-242干预），每组各12只大鼠。造模前3周时，IRI模型组和假手术组静脉注射生理盐水，TLR4激活组静脉注射脂多糖，TLR4抑制组静脉注射TAK-242，每周1次，连续3周。IRI模型组、TLR4激活组和TLR4抑制组均于末次注射30 min后建立肺缺血再灌注损伤模型。假手术组除不阻断肺门外，其他操作方法同前。再灌注损伤后3 h采用逆转录聚合酶联反应（RT-PCR）检测各组大鼠肺组织中Toll样受体4（TLR4）、缺氧诱导因子-1α（HIF-1α）、肿瘤坏死因子-α（TNF-α）和白细胞介素-6（IL-6）mRNA表达，采用免疫印迹法（Western-blot）检测各组大鼠肺组织中TLR4、HIF-1α、TNF-α和IL-6蛋白表达水平。 结果 肺湿重/干重值IRI模型组高于假手术组（P < 0.05），TLR4激活组高于IRI模型组（P < 0.05），TLR4抑制组低于IRI模型组（P < 0.05）；肺组织中TLR4、HIF-1α、TNF-α、IL-6 mRNA和蛋白表达水平IRI模型组高于假手术组（P < 0.05），TLR4激活组高于IRI模型组（P < 0.05），TLR4抑制组低于IRI模型组（P < 0.05）。 结论 大鼠肺IRI后，肺组织中TLR4信号通路介導HIF-1α的水平显著升高，会增加对肺组织的炎症损伤程度。

[关键词] 肺缺血再灌注损伤；Toll样受体4；缺氧诱导因子-1α

[中图分类号] R563 [文献标识码] A [文章编号] 1673-7210（2017）05（c）-0018-05

[Abstract] Objective To investigate the changes and significance of hypoxia inducible factor-1α （HIF-1α） mediated by Toll like receptor 4 （TLR4） signal pathway in the model of lung ischemia reperfusion injury （IRI） rats. Methods A total of 48 healthy male SD rats were selected and randomly divided into sham operation group， IRI model group， TLR4 activation group （LPS intervention） and TLR4 inhibition group （TAK-242 intervention） with 12 rats in each group. 3 weeks before model， IRI model group and sham operation group were injected with saline， TLR4 activation group was injected with lipopolysaccharide， TLR4 inhibition group was injected with TAK-242， once a week for three weeks. IRI model group， TLR4 activation group and TLR4 inhibition group were established a model of lung ischemia-reperfusion injury after last injection 30 minutes， sham operation group was treated same as the other groups except for not block the lung door. 3 hours after reperfusion injury， TLR4， HIF-1α， tumor necrosis factor-α （TNF-α） and interleukin-6 （IL-6） mRNA expression of lung tissue were tested by reverse transcriptase polymerase chain reaction （RT-PCR）. TLR4， HIF-1α， TNF-α and IL-6 protein expression of lung tissue were tested by Western-blot. Results The lung wet weight/dry weight ratio of the IRI model group was higher than that of the sham operation group （P < 0.05）， the TLR4 activation group was higher than that of the model group （P < 0.05）， and the TLR4 inhibition group was lower than that of the model group （P < 0.05）. The mRNA and protein expression levels of TLR4， HIF-1α， TNF-α， IL-6 in the lung tissues of IRI model group were higher than those of the sham operation group （P < 0.05）， the TLR4 activation were higher than those of the model group （P < 0.05）， and the TLR4 inhibition group were lower than those of the model group （P < 0.05）. Conclusion The TLR4 signal pathway in the lung tissue mediates the HIF-1α expression increased significantly after lung ischemia-reperfusion injury in rats， and increases the degree of inflammatory damage to the lung tissue.

[Key words] Ischemia reperfusion injury of lung； Toll like receptor 4； Hypoxia inducible factor-1α

肺缺血再灌注损伤（ischemia reperfusion injury，IRI）是临床心肺术后较为常见的并发症之一，其可诱发一系列复杂的级联反应并导致肺损伤，严重影响患者的预后效果[1-3]。研究表明，IRI的发生和发展是一个复杂的病理过程，涉及炎性反应、氧化应激反应、自由基产生、促炎介质释放等过程[4]。而局部炎性反应又可诱发全身性炎性反应甚至是器官衰竭的发生，最终可导致死亡[5-8]。Toll样受体4（TLR4）信号通路被认为是炎性反应的重要信号因子，而缺氧诱导因子-1α（HIF-1α）是缺氧的信号因子之一，且二者之间具有相互调控机制，可进一步导致促炎性反应的发生，进而参与IRI的发生和发展[9]。……