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Golomingi M, Kohler J, Jenny L, Hardy ET, Dobó J, Gál P, Pál G, Kiss B, Lam WA, Schroeder V. Complement lectin pathway components MBL and MASP-1 promote haemostasis upon vessel injury in a microvascular bleeding model. Front Immunol 2022; 13:948190. [PMID: 36032172 PMCID: PMC9412763 DOI: 10.3389/fimmu.2022.948190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 07/04/2022] [Indexed: 11/13/2022] Open
Abstract
BackgroundComplement lectin pathway components, in particular mannan-binding lectin (MBL) and MBL-associated serine proteases (MASPs) have been shown to interact with coagulation factors and contribute to clot formation. Here we investigated the role of MBL and MASP-1 in the haemostatic response following mechanical vessel injury in a human microfluidic bleeding model.MethodsWe studied haemostasis in a microvascular bleeding model in the presence of human endothelial cells and human whole blood under flow conditions. We monitored incorporation of proteins into the clot with fluorescently labelled antibodies and studied their effects on clot formation, platelet activation, and bleeding time with specific inhibitors. Platelet activation was also studied by flow cytometry.ResultsUpon vessel injury, MBL accumulated at the injury site in a well-defined wall-like structure. MBL showed partial colocalisation with fibrin, and strong colocalisation with von Willebrand factor and (activated) platelets. Flow cytometry ruled out direct binding of MBL to platelets, but confirmed a PAR4- and thrombin-dependent platelet-activating function of MASP-1. Inhibiting MBL during haemostasis reduced platelet activation, while inhibiting MASP-1 reduced platelet activation, fibrin deposition and prolonged bleeding time.ConclusionWe show in a microvascular human bleeding model that MBL and MASP-1 have important roles in the haemostatic response triggered by mechanical vessel injury: MBL recognises the injury site, while MASP-1 increases fibrin formation, platelet activation and shortens bleeding time. While the complement lectin pathway may be harmful in the context of pathological thrombosis, it appears to be beneficial during the physiological coagulation response by supporting the crucial haemostatic system.
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Affiliation(s)
- Murielle Golomingi
- Experimental Haemostasis Group, Department for BioMedical Research, DBMR, University of Bern, Bern, Switzerland
| | - Jessie Kohler
- Experimental Haemostasis Group, Department for BioMedical Research, DBMR, University of Bern, Bern, Switzerland
| | - Lorenz Jenny
- Experimental Haemostasis Group, Department for BioMedical Research, DBMR, University of Bern, Bern, Switzerland
| | - Elaissa T. Hardy
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States
| | - József Dobó
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
| | - Péter Gál
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
| | - Gábor Pál
- Department of Biochemistry, Eötvös Loránd University, Budapest, Hungary
| | - Bence Kiss
- Department of Biochemistry, Eötvös Loránd University, Budapest, Hungary
| | - Wilbur A. Lam
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States
| | - Verena Schroeder
- Experimental Haemostasis Group, Department for BioMedical Research, DBMR, University of Bern, Bern, Switzerland
- *Correspondence: Verena Schroeder,
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