Endocytosed factor V is trafficked to CD42b+ proplatelet extensions during differentiation of human umbilical cord blood‐derived megakaryocytes

• DOI: 10.1002/jcp.26749
• Publication Date: 2018-05-15T11:39:38Z
• Authors: Jacqueline M. Gertz; Kelley C. McLean; Beth A. Bouchard
• Keywords: Cord blood

Plasma‐ and platelet‐derived factor Va are essential for thrombin generation catalyzed by the prothrombinase complex; however, several observations demonstrate that cofactor, which is formed following megakaryocyte endocytosis modification of plasma procofactor, V, more hemostatically relevant. Factor V endocytosis, as a function differentiation proplatelet formation, was assessed flow cytometry microscopy in CD34 + hematopoietic progenitor cells isolated from human umbilical cord blood cultured 12 days presence cytokines to induce ex vivo into megakaryocytes. Expression an early marker differentiation, CD41, percentage CD41 endocytosed increased 6 differentiation. In contrast, statistically significant decreases expression stem cell marker, CD34, were observed. A increase CD42b, late also observed over time, such Day 12, all CD42b expressed CD41. This trafficked extensions localized punctate pattern cytoplasm consistent with its storage α‐granules. conclusion, loss define capable trafficking during megakaryocytes blood.