Decoding Endothelial MPL and JAK2V617F Mutation: Insight into Cardiovascular Dysfunction in Myeloproliferative Neoplasms

Background: Patients with JAK2V617F-positive myeloproliferative neoplasms (MPNs) and clonal hematopoiesis of indeterminate potential (CHIP) face a significantly elevated risk of cardiovascular diseases (CVDs). Endothelial cells (ECs) carrying the JAK2V617F mutation have been detected in many MPN patients. In this study, we investigated the molecular basis for the high incidence of cardiovascular complications in MPN patients. Methods: We investigated the impact of endothelial JAK2V617F mutation on CVD development using both transgenic murine models and MPN patient-derived induced pluripotent stem cell lines. Results and Conclusions: Our investigations revealed that JAK2V617F mutant ECs promote CVDs by impairing endothelial function and undergoing endothelial-to-mesenchymal transition (EndMT). Importantly, we discovered that inhibiting the endothelial thrombopoietin receptor MPL suppressed JAK2V617F-induced EndMT and prevented cardiovascular dysfunction caused by mutant ECs. Notably, the endothelial MPL receptor is not essential for the normal physiological regulation of blood cell counts and cardiac function, rendering it a promising therapeutic target for preventing or ameliorating cardiovascular complications in patients with MPNs. To gain insight into the transcriptomic changes associated with the JAK2V617F mutation and MPL inhibition on endothelial cells, we performed RNA sequencing on untreated and AMM2 MPL inhibitor treated endothelial cells of wild-type and JAK2V617F mutant mice.