Endothelial-to-Mesenchymal Transition in Bone Marrow and Spleen of Primary Myelofibrosis.

Endothelial-to-Mesenchymal Transition in Bone Marrow and Spleen of Primary Myelofibrosis.
Am J Pathol. 2017 Aug;187(8):1879-1892
Authors: Erba BG, Gruppi C, Corada M, Pisati F, Rosti V, Bartalucci N, Villeval JL, Vannucchi AM, Barosi G, Balduini A, Dejana E
Abstract
Primary myelofibrosis is characterized by the development of fibrosis in the bone marrow that contributes to ineffective hematopoiesis. Bone marrow fibrosis is the result of a complex and not yet fully understood interaction among megakaryocytes, myeloid cells, fibroblasts, and endothelial cells. Here, we report that >30% of the endothelial cells in the small vessels of the bone marrow and spleen of patients with primary myelofibrosis have a mesenchymal phenotype, which is suggestive of the process known as endothelial-to-mesenchymal transition (EndMT). EndMT can be reproduced in vitro by incubation of cultured endothelial progenitor cells or spleen-derived endothelial cells with inflammatory cytokines. Megakaryocytes appear to be implicated in this process, because EndMT mainly occurs in the microvessels close to these cells, and because megakaryocyte-derived supernatant fluid can reproduce the EndMT switch in vitro. Furthermore, EndMT is an early event in a JAK2-V617F knock-in mouse model of primary myelofibrosis. Overall, these data show for the first time that microvascular endothelial cells in the bone marrow and spleen of patients with primary myelofibrosis sho...

Source: The American Journal of Pathology - July 23, 2017 Category: Pathology Authors: Erba BG, Gruppi C, Corada M, Pisati F, Rosti V, Bartalucci N, Villeval JL, Vannucchi AM, Barosi G, Balduini A, Dejana E Tags: Am J Pathol Source Type: research