Endothelial Cells Harbouring the JAK2V617F Mutation Display Pro-Adherent and Pro-Thrombotic Features.

Thromboembolic events are the main cause of mortality in BCR-ABL1-negative myeloproliferative neoplasms (MPNs) but their underlying mechanisms are largely unrecognized. The Janus kinase 2 (JAK2) mutation is the most frequent genetic alteration leading to MPN. Usually found in haematopoietic progenitors and stem cells, this mutation has also been described in endothelial cells (ECs) of MPN patients. In this study, we have questioned the impact of the JAK2 mutation on EC phenotype and functions. We developed an induced pluripotent stem cells strategy to compare JAK2 mutant and wild-type ECs. Transcriptomic assays showed that several genes and pathways involved in inflammation, cell adhesion and thrombotic events were over-represented in JAK2 ECs and expression levels of von Willebrand factor and P-selectin (CD62P) proteins were increased. Finally, we found that leucocytes from MPN patients adhere more tightly to JAK2 ECs. Our results show that JAK2 ECs have a pro-inflammatory and pro-thrombotic phenotype and were functionally pro-adherent.