RESUMEN
ObjectiveTo explore the mechanisms of Astragali Radix-Curcumae Rhizoma （HQ-EZ） in alleviating hypercoagulability and inhibiting tumor growth and metastasis by modulating the formation of neutrophil extracellular traps （NETs） via the complement component 5a （C5a）/C5a receptor （C5aR） pathway. MethodForty male C57BL/6 mice were randomized into four groups： Blank， model， HQ-EZ （8.2 g·kg-1）， and PMX53 （1 mg·kg-1）. The mouse model of Lewis lung cancer was established in other three groups except the blank group. Mice were administrated with corresponding drugs from day 3 after modeling. Specifically， the HQ-EZ decoction was administrated for 14 consecutive days， while intraperitoneal injection of PMX53 was implemented on days 3， 6， 9， 12， and 15. Mouse body weight and tumor diameter were measured every two days. On the next day of the last administration， lung microCT was performed to observe the tumor metastasis in vivo. Blood samples were collected from the eyeball after anesthetization， and tumor and lungs were collected after the mice were sacrificed. Tumor weight was measured to calculate the tumor growth inhibitory rate. Enzyme-linked immunosorbent assay was employed to measure the levels of C5a， neutrophil elastase （NE）， citrullinated histone-H3 （Cit-H3）， myeloperoxidase （MPO）， matrix metallopeptidase-9 （MMP-9）， NETs， von Willebrand Factor （vWF）， tissue factor （TF）， and P-selectin in the serum and tumor tissue. Terminal-deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling was conducted to assess apoptosis in the tumor tissue. Hematoxylin-eosin staining was conducted to observe lung metastasis， and immunofluorescence （IF） was employed to observe the expression of NETs in the tumor tissue. Western blot was employed to determine the protein levels of C5aR， MPO， and Cit-H3 in the tumor tissue. ResultCompared with the blank group， the model group had nodules in the lung， increased areas with low X-ray transmittance， appearance of nodular foci and multiple hemorrhagic foci in the lungs， and darkening lung color. Furthermore， the modeling elevated the serum levels of C5a， NETs and related proteins， vWF， TF， and P-selectin （P<0.01）. Compared with the model group， HQ-EZ and PMX53 reduced the lung metastases， areas with low X-ray transmittance， and nodules in the lungs and lightened the lung color. Compared with the model group， the two drug intervention groups showed flat tumor growth curves， decreased tumor weight （P<0.01）， increased apoptosis of tumor cells （P<0.01）， lowered levels of C5a， NETs and related proteins， vWF， TF， and P-selectin both in the serum and tumor tissue （P<0.05）， and down-regulated protein levels of C5aR， MPO， and Cit-H3 （P<0.05）. ConclusionHQ-EZ inhibited the expression of NETs by suppressing the C5a/C5aR pathway， thereby alleviating hypercoagulability and inhibiting tumor growth and metastasis.
RESUMEN
To improve thrombolytic effect, a fusion protein SFH composed of staphylokinase (SAK) and hirudin (HV) with blood coagulation factor Xa (FXa) recognition peptide as a linker, was designed. SFH showed improved thrombolytic effect and low bleeding in vivo. Two thrombus-targeting mechanisms might account for the above features of SFH. This study was designed to study the two thrombus-targeting mechanisms of SFH. ELISA and immunohistochemistry assay were used to study the improved thrombus selectivity of SFH and the results showed that SFH, compared with SAK, displayed higher affinity for thrombin and thrombin-rich thrombus. To verify the thrombus-targeting release of anticoagulant activity of SFH, FH-a derivative of HV with only FXa recognition sequence at N terminus of HV was designed and used in animal tests. In inferior vena cava thrombosis model, FH showed equal antithrombotic effect as HV, indicating that HV could be successfully released from FH by FXa cleavage in vivo. More importantly, no prolongation of plasma TT, APTT and PT were found in FH group, but significant prolongations were discovered in HV group. This revealed that the anticoagulant activity of FH was released in thrombus-targeting way and limited in the vicinity of the thrombus, and this could be extrapolated to SFH. In conclusion, the high thrombus affinity and thrombus-targeting release of anticoagulant activity of SFH assigned low bleeding risk to SFH.