Reduced Production of JAK2V617F-positive Microparticles at Mild Hypothermia

The Philadelphia chromosome-negative (Ph-) myeloproliferative neoplasms (MPNs) are a group of blood cancers that arise from abnormal growth of blood cells in the bone marrow. Patients with MPNs are at increased risk for life-threatening thromboembolic complications. The detection of JAK2V617F in endothelial cells (ECs) brought a new perspective to the research of thromboembolic events. However, the mechanisms by which the mutation contributes to risk have yet to be entirely understood. Consequently, the objective of this study was to investigate how JAK2V617F impacts endothelial cells by considering thermoregulation.

We applied our previously created model for EC that was genetically modified with JAK2 wild type (WT)-GFP and JAK2V617F-GFP lentiviruses; the cells were cultured for 48 h at 37°C for normothermia and 32°C for mild hypothermia. We examined the effect of thermoregulation on infection efficiency and the expression of cell surface markers, including endothelial protein C receptor (EPCR), thrombomodulin (TM), and tissue factor (TF), which are related to the coagulation pathways. Furthermore, the microparticle production from the genetically modified EC (EMPs) was analyzed.

We found suppression of the expression of coagulation factors, including EPCR, TM, and TF in JAK2V617F positive ECs under mild hypothermia. JAK2V617F-positive ECs showed slightly higher EMP production under mild hypothermia.

Although the molecular mechanisms of the thermal effects on the tumor microenvironment with JAK2V617F and its effect on EMP production and coagulation are not known yet, the therapy-oriented effect of thermoregulation might be considered in future studies.