hirudin and Acute-Lung-Injury

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

Topics: Acute Lung Injury; Animals; Blood Coagulation; Chemokines; Chemotaxis, Leukocyte; Endothelial Cells; Hirudins; Humans; Inflammation; Leeches; Lipopolysaccharides; Lipoproteins; Lung; Mice, Inbred C57BL; Mice, Transgenic; Platelet Endothelial Cell Adhesion Molecule-1; Pseudomonas aeruginosa; Receptors, Proteinase-Activated; Recombinant Fusion Proteins; Thrombin; Thromboplastin

Acute lung injury (ALI) and systemic coagulopathy are serious complications of traumatic brain injury (TBI) that frequently lead to poor clinical outcomes. Although the release of tissue factor (TF), a potent initiator of the extrinsic pathway of coagulation, from the injured brain is thought to play a key role in coagulopathy after TBI, its function in ALI following TBI remains unclear. In this study, we investigated whether the systemic appearance of TF correlated with the ensuing coagulopathy that follows TBI in ALI using an anesthetized rat blunt trauma TBI model. Blood and lung samples were obtained after TBI. Compared with controls, pulmonary edema and increased pulmonary permeability were observed as early as 5 min after TBI without evidence of norepinephrine involvement. Systemic TF increased at 5 min and then diminished 60 min after TBI. Lung injury and alveolar hemorrhaging were also observed as early as 5 min after TBI. A biphasic elevation of TF was observed in the lungs after TBI, and TF-positive microparticles (MPs) were detected in the alveolar spaces. Fibrin(ogen) deposition was also observed in the lungs within 60 min after TBI. Additionally, preadministration of a direct thrombin inhibitor, Refludan, attenuated lung injuries, thus implicating thrombin as a direct participant in ALI after TBI. The results from this study demonstrated that enhanced systemic TF may be an initiator of coagulation activation that contributes to ALI after TBI.

Topics: Acute Lung Injury; Animals; Antithrombins; Blood Coagulation; Brain Injuries, Traumatic; Glial Fibrillary Acidic Protein; Hirudins; Macrophages, Alveolar; Male; Platelet Aggregation; Platelet Count; Rats, Sprague-Dawley; Recombinant Proteins

The aim of this study was to observe the effect of hirudin on the expression of lung tissue protease activated receptor-1 (PAR-1) and the correlation between inflammation factors and the expression of PAR-1 after hirudin pre-treatment and to provide the theoretical basis for the treatment of lung injury by hirudin. Wistar rats of the model group were intraperitoneally administered endotoxin by injection (LPS 10 mg/kg) to copy acute lung injury (ALI) animal models, while the rats of the control group were injected with an equal amount of physiological saline. The rats of the hirudin groups were injected with hirudin and endotoxin intraperitoneally at the same time. The lung tissue was stained by HE dye to detect tumor necrosis factor α (TNF-α) and matrix metallo-proteinase 12 (MMP12) content. RT-PCR was applied to test PAR-1 mRNA expression. The results showed that the expression of PAR-1 mRNA of lung tissue increased significantly, but declined with the increased doses of hirudin when lung injury due to endotoxin occurred. The content of TNF-α and MMP12 was significantly lower compared to that of the endotoxin group. The difference was statistically significant (p<0.05). Hirudin reduced the release of TNF-α and MMP12 in mice by inhibiting the production of PAR-1 and reduced the content of TNF-α and MMP12. Thus, we deduced that hirudin inhibits the inflammation and fibrosis caused by lung injury and plays a role in lung protection as an anti-inflammatory mediator.

Topics: Acute Lung Injury; Animals; Disease Models, Animal; Fibrinolytic Agents; Gene Expression Regulation; Hirudin Therapy; Hirudins; Lipopolysaccharides; Matrix Metalloproteinase 12; Rats; Rats, Wistar; Receptor, PAR-1; Tumor Necrosis Factor-alpha