Megakaryocytes are large cells that play an important role in haemostasis through the production of platelets, cell-to-cell communication, and maintenance of the bone marrow niche. In particular, platelets are critical to the clotting process and maintenance of vascular integrity. Despite their importance, in vitro production of megakaryocytes and platelets is limited, and the main supply of platelets still relies on plasma donations.
In the bone marrow, megakaryocytes mature from hematopoietic stem cells (HSCs). Within the HSC compartment, two populations can be distinguished based on their self-renewal capacity: long term hematopoietic stem cells (LT-HSCs) and short-term hematopoietic stem cells (ST-HSCs). In the mouse, there are three proposed pathways for megakaryocyte development: classical, alternative, and myeloid bypass. For both the classical and alternative pathway, megakaryocyte progenitors are differentiated from ST-HSCs through multipotent progenitors, and development from these cells occur in a stepwise manner. Unique to the classical model are more restricted progenitors, the common myeloid progenitor (CMP) as well as megakaryocyte-erythroid progenitor (MEP), which have both been shown to develop into megakaryocyte progenitors. In the myeloid bypass pathway, LT-HSCs directly differentiate into megakaryocyte progenitors.
Using flow cytometry, all cells involved in each megakaryocyte maturation pathway were isolated and sequenced through the 10x single cell sequencing platform. With this in vivo dataset, we will investigate and compare megakaryocyte differentiation. In the future, we plan to compare this dataset with an in vitro dataset which will comprise of high-end stem/multipotent progenitor populations that have been isolated and matured into megakaryocytes in culture. This will provide insight into the path to megakaryopoiesis and inform in vitrosystems of megakaryocyte - and ultimately platelet - production.