Key Laboratory of Respiratory Disease of Zhejiang Province, Department of Respiratory and Critical Care Medicine, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China.
Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, Shanghai, 200032, China.
Acta Pharmacol Sin. 2019 Jun;40(6):769-780. doi: 10.1038/s41401-018-0175-7. Epub 2018 Nov 16.
Tissue factor (TF)-dependent coagulation contributes to lung inflammation and the pathogenesis of acute lung injury (ALI). In this study, we explored the roles of targeted endothelial anticoagulation in ALI using two strains of transgenic mice expressing either a membrane-tethered human tissue factor pathway inhibitor (hTFPI) or hirudin fusion protein on CD31 cells, including vascular endothelial cells (ECs). ALI was induced by intratracheal injection of LPS, and after 24 h the expression of TF and protease-activated receptors (PARs) on EC in lungs were assessed, alongside the extent of inflammation and injury. The expression of TF and PARs on the EC in lungs was upregulated after ALI. In the two strains of transgenic mice, expression of either of hTFPI or hirudin by EC was associated with significant reduction of inflammation, as assessed by the extent of leukocyte infiltration or the levels of proinflammatory cytokines, and promoted survival after LPS-induced ALI. The beneficial outcomes were associated with inhibition of the expression of chemokine CCL2 in lung tissues. The protection observed in the CD31-TFPI-transgenic strain was abolished by injection of an anti-hTFPI antibody, but not by prior engraftment of the transgenic strains with WT bone marrow, confirming that the changes observed were a specific transgenic expression of anticoagulants by EC. These results demonstrate that the inflammation in ALI is TF and thrombin dependent, and that expression of anticoagulants by EC significantly inhibits the development of ALI via repression of leukocyte infiltration, most likely via inhibition of chemokine gradients. These data enhance our understanding of the pathology of ALI and suggest a novel therapeutic strategy for treatment.
组织因子（TF）依赖性凝血会导致肺部炎症和急性肺损伤（ALI）的发病机制。在这项研究中，我们使用两种转染小鼠来探索靶向内皮抗凝在 ALI 中的作用，这两种转染小鼠在 CD31 细胞上表达膜结合的人组织因子途径抑制剂（hTFPI）或水蛭素融合蛋白，包括血管内皮细胞（EC）。通过气管内注射 LPS 诱导 ALI，然后评估肺 EC 上 TF 和蛋白酶激活受体（PARs）的表达，以及炎症和损伤的程度。ALI 后肺 EC 上 TF 和 PARs 的表达上调。在这两种转染小鼠中，hTFPI 或水蛭素的表达均可显著降低炎症程度，如白细胞浸润程度或促炎细胞因子水平，并且可促进 LPS 诱导的 ALI 后的存活。有益的结果与趋化因子 CCL2 在肺组织中的表达抑制有关。在 CD31-TFPI 转基因株中观察到的保护作用被抗 hTFPI 抗体的注射所消除，但不会被 WT 骨髓预先移植到转基因株中所消除，证实了所观察到的变化是 EC 中抗凝剂的特定转基因表达。这些结果表明，ALI 中的炎症是 TF 和凝血酶依赖性的，并且 EC 表达抗凝剂可通过抑制白细胞浸润来显著抑制 ALI 的发展，这很可能是通过抑制趋化因子梯度。这些数据增强了我们对 ALI 病理学的理解，并为治疗提供了一种新的治疗策略。
