Shear-Mediated Platelet Microparticles Demonstrate Phenotypic Heterogeneity as to Morphology, Receptor Distribution,...

Area of Science:

• Biomedical Engineering
• Hematology
• Cardiovascular Research

Background:

• Implantable cardiovascular therapeutic devices (CTDs) can cause device-related coagulopathy, leading to thrombotic and bleeding complications.
• Previous research indicated shear-mediated platelet dysfunction is linked to receptor downregulation via platelet-derived microparticles (PDMPs).

Approach:

• Human platelets were subjected to shear stress and sonication.
• Platelet morphology was analyzed via transmission electron microscopy.
• Flow cytometry quantified receptor expression and PDMP generation, while thrombin generation and aggregation were measured.

Key Points:

• Shear stress alters platelet morphology and generates distinct PDMP types.
• PDMPs exhibit heterogeneous surface receptor expression, including adhesion and agonist-evoked receptors.
• Shear-mediated PDMPs bidirectionally affect hemostasis, promoting thrombin generation while inhibiting aggregation.

Conclusions:

• Shear-generated PDMPs display phenotypic heterogeneity in morphology and receptor expression.
• This heterogeneity suggests complex microvesiculation mechanisms contributing to CTD coagulopathy.
• Understanding PDMP heterogeneity offers potential therapeutic targets for managing device-related bleeding and clotting.