HPA deficiency alleviates tissue factor expression in sepsis-induced coagulopathy by regulating HS/NLRP3 inflammasome pathway.

BACKGROUND

Heparanase (HPA) is activated in sepsis with the consequent degradation of heparan sulfate (HS) and compromising glycocalyx integrity. The NLR-family pyrin domain-containing 3 (NLRP3) inflammasome plays a critical role in initiating the coagulation cascade. Nonetheless, it remains uncertain whether HS fragments contribute to the activation of coagulation via the NLRP3 inflammasome during sepsis.

METHODS

Serum concentrations of HPA, HS, and tissue factor (TF) in sepsis patients were quantified using enzyme-linked immunosorbent assay (ELISA). Mechanistic studies were conducted using wild-type and HPA-knockout C57BL/6 mice, as well as human umbilical vein endothelial cells (HUVECs).

RESULTS

Patients diagnosed with sepsis or sepsis-induced coagulopathy (SIC) exhibited significantly elevated serum levels of HPA, HPA enzymatic activity, HS, and TF compared to healthy controls. A positive correlation was observed between TF levels and both HPA and HS concentrations, as well as with the severity of the disease. The area under the curve (AUC) for TF in predicting SIC was 0.786. In both in vivo sepsis models and lipopolysaccharide (LPS)-stimulated HUVECs, either genetic deletion or pharmacological inhibition of HPA attenuated HS degradation, preserved endothelial glycocalyx, reduced TF expression, suppressed the release of IL-1β, and ameliorated coagulation dysfunction. HPA deficiency also mitigated lung histopathological injury and improved survival rate in septic mice. Supplementation with exogenous HS upregulated TF expression and activated the NLRP3/caspase-1/gasdermin D (GSDMD) pathway in HUVECs. Inhibition of the NLRP3 inflammasome suppressed HS-induced TF expression and pyroptotic cell death.

CONCLUSION

HPA modulates the HS/NLRP3 inflammasome pathway, which seem linked to protection against LPS-induced coagulation dysfunction. The detailed results warrant deep studies in the potential of that pathway as therapeutic target.