Biogenesis of blood platelets
Platelets are corpuscular blood components and essential for hemostasis. Platelet counts in humans are normally between 150000 and 400000 in every µl blood. If the platelet count drops below 150000 the lack is referred to as thrombocytopenia and often associated with prolonged bleeding. A low platelet count can be acquired, for instance through the use of drugs like heparin or as by formation of auto-antibodies that recognize the body-own platelets as a consequence of an infection. The thrombocytopenia can also be congenital due to a genetic defect.
Platelets are generated by shedding from precursor cells in the bone marrow, designated megakaryocytes. Every single megakaryocyte can release about 1000 platelets from the bone marrow cavity into the blood stream. During the fascinating cell biological process every platelet becomes equipped with a microtubule marginal coil, a cytoskeletal scaffold that is essential to maintain a discoid platelet shape. Platelets also contain assorted granules that are released when platelets are activated at the site of blood vessel injury in order to help stopping the bleeding.
My group is focused on two aspects of platelet biogenesis: First, we are interested to identify the cell biological mechanisms and key players that regulate the shedding of platelets from a megakaryocyte. Second, we are analyzing the different defects that lead to thrombocytopenia, especially in case due to a decreased production in congenital thrombocytopenia like in the "thrombocytopenia-absent radii" (TAR)-syndrome.