ISCT Paris April 25 Ex vivo platelet production Dominique Baruch INSERM UMR-S1140, Paris
Platelet functions: to stop bleeding and beyond Adhesion Aggregation Clot retraction Secretion Procoagulant activity Microparticules «Additional platelet functions continue to come to light, and biologists have just described a novel way that the body might make these multitalented cells a finding that could one day ease the demand for donated blood.» Angiogenesis Source of growth factors Inflammation Immunity Sepsis Metastasis Post-natal vascular remodelling D.Baruch Platelet formation ISCT 25/04/2014 2
In vivo platelet production from megakaryocytes Science (2007) Migration of a mouse EYFP- IIb megakaryocyte near a sinusoid Passage of large MK fragments in the circulation 50 m Peripheral venous blood proplatelets D.Baruch Platelet formation ISCT 25/04/2014 3
Role of VWF and shear rates on platelet production To address the role of blood flow on megakaryocyte fragmentation into platelets using a VWF-coated surface Perfusion of human mature megakaryocytes in a parallel-plate flow chamber at high shear rates Videomicroscopy recording of single cell trajectories for 30 mins Human megakaryocytes 13 days culture D.Baruch Platelet formation ISCT 25/04/2014 4
Proplatelet and platelet formation from human megakaryocytes at high shear rates Flow D.Baruch Platelet formation ISCT 25/04/2014 5
Role of microtubules in proplatelet formation 10 images/s Flow D.Baruch Platelet formation ISCT 25/04/2014 6
Shear-derived platelets can be activated by thrombin No thrombin Thrombin D.Baruch Platelet formation ISCT 25/04/2014 7
Platelet production from mouse megakaryocytes Bioflux mvwf D.Baruch Platelet formation ISCT 25/04/2014 8
Shear-induced mouse platelets are functional in vivo in a thrombosis model Topical lesion by FeCl3 on mesenteric vessels Infusion of labelled platelets Intra-vital microscopy : real-time platelet thrombus formation Shear-derived platelets incorporate in thrombus of mesenteric vessels Static conditions or BSA do not support platelet thrombus formation D.Baruch Platelet formation ISCT 25/04/2014 9
Is platelet production regulated by Willebrand factor? Transition in circulating blood between different fragmentations states : from preplatelets to proplatelets and to platelets VWF? Adapted from Thon JN et al, JBC 2010 What would be the role of VWF in terminal platelet production? D.Baruch Platelet formation ISCT 25/04/2014 10
% proplatelets Terminal platelet production in Willebrand factor deficiency Role of exposure of platelets to VWF during their formation Experiments with human VWF deficient platelets of a patient with severe von Willebrand disease :absence of VWF in plasma, platelets, and endothelial cells A pre post C severe VWD 40 35 30 25 B pre post Control 20 15 10 5 0 0 4 6 8 12 16 20 24 28 Poirault-Chassac & al. PLOS One 2013 D.Baruch Platelet formation ISCT 25/04/2014 11
VWF Knock out mouse model proplatelet WT VWF -/- platelet WT KO VWF -/- Proplatelets D.Baruch Platelet formation ISCT 25/04/2014 12
Role of VWF in terminal platelet production VWF The role of VWF in terminal platelet production is: 1. To allow the conversion of preplatelets to proplatelets 2. To allow terminal fragmentation of proplatelets into platelets Proplatelets: reservoir of platelets ready to replace platelets needed to repair vessel injury Compatible model with small number of megakaryocytes leaving the bone marrow and the large daily circulating platelet production D.Baruch Platelet formation ISCT 25/04/2014 13
Megakaryocytic differentiation in 2D culture and 3D scaffolds D2 D12 D16 2D liquid culture Immature cells Mature MK D2 D6 D9 3D culture D12 D23 D30 Prolongation of cell survival and MK differentiation up to D30 in 3D scaffolds vs D16 in liquid culture D.Baruch Platelet formation ISCT 25/04/2014 14
Platelet production in 3D conditions 3D No activation Thrombin activation Liquid culture Increased platelet production in 3D conditions Platelets produced in flow conditions are functional D.Baruch Platelet formation ISCT 25/04/2014 15
Platelet production from induced pluripotent stem cells Takayama & al. J. Exp. Medicine 2010 The Nobel Prize in Physiology or Medicine 2012 D.Baruch Platelet formation ISCT 25/04/2014 16
Optimization of platelet production from induced pluripotent stem cells Eto & al. Cell Stem Cell 2014 D.Baruch Platelet formation ISCT 25/04/2014 17
Perspectives Innovative source of platelets for tomorrow s platelet transfusion? PLASMIS Large-scale platelet production from stem cells in microfluidic devices D.Baruch Platelet formation ISCT 25/04/2014 18
Acknowledgements INSERM UMR_S1140 and Paris Sorbonne University Claire Dunois-Lardé Sonia Poirault-Chassac Audrey Pietrzyk Alexandre Kauskot Kim-Anh Nguyen PLASTHER CONSORTIUM INSERM U1016 Isabelle Dusanter INSERM U770 Cécile Denis INSERM UMR_S1148 and Paris Sorbonne University Catherine Le Visage Didier Letourneur Mohamed Derkaoui PLASMIS CONSORTIUM UMR CNRS7083 INSERM U1009 Mathilde Reyssat Najet Debili INSERM U1016 INSERM U770 Isabelle Dusanter Cécile Denis Lab Hematology CHU Bichat Paris Nadine Ajzenberg Lab Hematology CHU HEGP Paris Pascale Gaussem Lab Thrombosis Research KU Leuven Hans Deckmyn D.Baruch Platelet formation ISCT 25/04/2014 19