The Role Of Soluble Thrombomodulin In Sepsis With Capillary Leak

Sepsis is a common complication of burns,trauma,and severe infections,which may lead to disseminated intravascular coagulation(DIC),shock to multiple organ dysfunctions and it serves as the first cause of death in critically ill patients.Thrombomodulin(TM)is a single-chain transmembrane glycoprotein mainly expressed on the surface of endothelial cells,but it can also be enzymatically digested by inflammatory factors to form soluble fragments of different sizes.It has been reported that the levels of soluble thrombomodulin in the blood of patients with multiple organ dysfunctions due to sepsis or trauma are significantly higher than those of healthy individuals.Vascular leak caused by increased endothelial permeability may be an important link in the development of sepsis and play a key impact on the progress of the disease.In this study,with an aim to explore the role of soluble thrombomodulin in sepsis capillary leak,and specifically the effect of the soluble epidermal growth factor-like domain(TM-D2)on endothelial monolayer permeability,we carried out ELISA detection,construction of endothelial monolayer model,permeability evaluation,cell viability measurement,plasmid construction,expression and purification of the recombinant protein to achieve the following results:1.The release of thrombomodulin on the surface of endothelial cells was significantly increased by elastase.2.Cellular supernatants containing soluble thrombomodulin can decrease the permeability of the endothelial monolayer to macromolecules,and the antithrombomodulin EGF-2 antibody can partially block this protective effect.3.Recombinant pichia yeast strain was successfully obtained and the recombinant protein rTM-D2 was obtained after induction and purification.