An assay to evaluate heparanase procoagulant activity

Area of Science:

• Biochemistry
• Hematology
• Reproductive Medicine

Background:

• Heparanase, abundant in the placenta, is linked to cell invasion, metastasis, and angiogenesis.
• Previous research established heparanase's role in regulating the hemostatic system by forming complexes with tissue factor (TF) and enhancing Factor Xa production.
• A novel assay is proposed to quantify heparanase's procoagulant activity.

Purpose of the Study:

• To develop and validate a new assay for measuring heparanase procoagulant activity.
• To investigate the role of heparanase in the procoagulant state of pregnant women.
• To compare heparanase activity with other hemostatic markers in pregnancy.

Main Methods:

• Utilized purified proteins (heparanase, TF, Factor VIIa, Factor X) to establish the assay.
• Validated the assay in 55 plasma samples (35 from third-trimester pregnant women, 20 from non-pregnant controls).
• Compared assay results with ELISA for heparanase and TFPI, and chromogenic substrates for Factor Xa, thrombin, and antithrombin levels.

Main Results:

• The assay successfully differentiated heparanase's procoagulant effect from TF activity in purified systems.
• Heparanase procoagulant activity was significantly elevated in pregnant women compared to non-pregnant controls (p < 0.005).
• Heparanase's relative contribution to TF/heparanase complex activity increased by 29% in pregnant women (p < 0.0001), exceeding changes in other measured markers.

Conclusions:

• The developed assay reliably determines heparanase procoagulant activity.
• Heparanase significantly contributes to the procoagulant state in late pregnancy and during delivery.
• This assay provides a valuable tool for assessing heparanase's role in pregnancy-related hemostatic changes.