(funded until June 2022 by TR 240)
Platelets, also called thrombocytes, are a component of blood which are important to stop bleeding by clumping, thereby initiating a blood clot. Circulating platelets are lens-shaped structures, 2–3 µm in greatest diameter. Platelets are produced by bone marrow megakaryocytes (MKs), which extend long cytoplasmic pro-trusions, designated proplatelets, into sinusoidal blood vessels where these proplatelets undergo fission to release platelets. Patients with defects in platelet production have a low platelet count (thrombocytopenia), which can lead to an increased bleeding risk. There is still a remarkable gap of understanding the underlying molecular mechanisms of platelet production and a more detailed un-derstanding of this biological process is warranted to better treat patients suffering from bleedings due to low platelet counts. Optogenetics is a method that uses light to modulate cellular activity or animal behaviour by gene transfer of photo-sensitive proteins. Recent developments in the field tend to address a broader scope of cellular and molecular biology besides neurobiology. In this proposal, we intend to establish optogenetics in the field of platelet research in order to precisely control and manipulate platelet production using light and thereby identify key players and mechanisms involved in this complex process, see figure.