biostudies-literatureBourne JHMarie Sklodowska-Curie ActionsBritish Heart FoundationFS/IBSRF/20/25039766118CH/03/003AA/18/2/342181988-2000https://www.ebi.ac.uk/biostudies/studies/S-EPMC9718592biostudies-literatureUnknown122(12)C-type lectin-like receptor 2 (CLEC-2) is highly expressed on platelets and a subpopulation of myeloid cells, and is critical in lymphatic development. CLEC-2 has been shown to support thrombus formation at sites of inflammation, but to have a minor/negligible role in hemostasis. This identifies CLEC-2 as a promising therapeutic target in thromboinflammatory disorders, without hemostatic detriment. We utilized a GPIbα-Cre recombinase mouse for more restricted deletion of platelet-CLEC-2 than the previously used PF4-Cre mouse. clec1b^fl/flGPIbα-Cre⁺ mice are born at a Mendelian ratio, with a mild reduction in platelet count, and present with reduced thrombus size post-FeCl₃-induced thrombosis, compared to littermates. Antibody-mediated depletion of platelet count in C57BL/6 mice, to match clec1b^fl/flGPIbα-Cre⁺ mice, revealed that the reduced thrombus size post-FeCl₃-injury was due to the loss of CLEC-2, and not mild thrombocytopenia. Similarly, clec1b^fl/flGPIbα-Cre⁺ mouse blood replenished with CLEC-2-deficient platelets <i>ex vivo</i> to match littermates had reduced aggregate formation when perfused over collagen at arterial flow rates. In contrast, platelet-rich thrombi formed following perfusion of human blood under flow conditions over collagen types I or III, atherosclerotic plaque, or inflammatory endothelial cells were unaltered in the presence of CLEC-2-blocking antibody, AYP1, or recombinant CLEC-2-Fc. The reduction in platelet aggregation observed in clec1b^fl/flGPIbα-Cre⁺ mice during arterial thrombosis is mediated by the loss of CLEC-2 on mouse platelets. In contrast, CLEC-2 does not support thrombus generation on collagen, atherosclerotic plaque, or inflamed endothelial cells in human at arterial shear.Thrombosis and haemostasisCLEC-2 Supports Platelet Aggregation in Mouse but not Human Blood at Arterial Shear.PMC9718592Marie Sklodowska-Curie ActionsBritish Heart FoundationFS/IBSRF/20/25039CH/03/003/15571766118CH/03/003AA/18/2/34218Poulter NSWatson SPBourne JHBrown HCSmith CWMontague SJDi YJooss NJThomas MRRayes JfalseCLEC-2 Supports Platelet Aggregation in Mouse but not Human Blood at Arterial Shear.C-type lectin-like receptor 2 (CLEC-2) is highly expressed on platelets and a subpopulation of myeloid cells, and is critical in lymphatic development. CLEC-2 has been shown to support thrombus formation at sites of inflammation, but to have a minor/negligible role in hemostasis. This identifies CLEC-2 as a promising therapeutic target in thromboinflammatory disorders, without hemostatic detriment. We utilized a GPIbα-Cre recombinase mouse for more restricted deletion of platelet-CLEC-2 than the previously used PF4-Cre mouse. clec1b^fl/flGPIbα-Cre⁺ mice are born at a Mendelian ratio, with a mild reduction in platelet count, and present with reduced thrombus size post-FeCl₃-induced thrombosis, compared to littermates. Antibody-mediated depletion of platelet count in C57BL/6 mice, to match clec1b^fl/flGPIbα-Cre⁺ mice, revealed that the reduced thrombus size post-FeCl₃-injury was due to the loss of CLEC-2, and not mild thrombocytopenia. Similarly, clec1b^fl/flGPIbα-Cre⁺ mouse blood replenished with CLEC-2-deficient platelets <i>ex vivo</i> to match littermates had reduced aggregate formation when perfused over collagen at arterial flow rates. In contrast, platelet-rich thrombi formed following perfusion of human blood under flow conditions over collagen types I or III, atherosclerotic plaque, or inflammatory endothelial cells were unaltered in the presence of CLEC-2-blocking antibody, AYP1, or recombinant CLEC-2-Fc. The reduction in platelet aggregation observed in clec1b^fl/flGPIbα-Cre⁺ mice during arterial thrombosis is mediated by the loss of CLEC-2 on mouse platelets. In contrast, CLEC-2 does not support thrombus generation on collagen, atherosclerotic plaque, or inflamed endothelial cells in human at arterial shear.2022-01-01T00:00:00Z2022 Dec2025-04-19T17:28:41.247Z2025-04-19T17:28:41.247ZS-EPMC97185923581708310.1055/a-1896-6992