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Travert B, Rafat C, Mariani P, Cointe A, Dossier A, Coppo P, Joseph A. Shiga Toxin-Associated Hemolytic Uremic Syndrome: Specificities of Adult Patients and Implications for Critical Care Management. Toxins (Basel) 2021; 13:306. [PMID: 33925836 PMCID: PMC8145702 DOI: 10.3390/toxins13050306] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Revised: 04/21/2021] [Accepted: 04/21/2021] [Indexed: 01/28/2023] Open
Abstract
Shiga toxin-producing Escherichia coli-associated hemolytic uremic syndrome (STEC-HUS) is a form of thrombotic microangiopathy secondary to an infection by an enterohemorrhagic E. coli. Historically considered a pediatric disease, its presentation has been described as typical, with bloody diarrhea at the forefront. However, in adults, the clinical presentation is more diverse and makes the early diagnosis hazardous. In this review, we review the epidemiology, most important outbreaks, physiopathology, clinical presentation and prognosis of STEC-HUS, focusing on the differential features between pediatric and adult disease. We show that the clinical presentation of STEC-HUS in adults is far from typical and marked by the prevalence of neurological symptoms and a poorer prognosis. Of note, we highlight knowledge gaps and the need for studies dedicated to adult patients. The differences between pediatric and adult patients have implications for the treatment of this disease, which remains a public health threat and lack a specific treatment.
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Affiliation(s)
- Benoit Travert
- Service de Médecine Interne, Hôpital Bichat, Assistance Publique-Hôpitaux de Paris, 75018 Paris, France; (B.T.); (A.D.)
- Centre de Référence des Microangiopathies Thrombotiques (CNR-MAT), Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Antoine, 75012 Paris, France; (C.R.); (P.C.)
| | - Cédric Rafat
- Centre de Référence des Microangiopathies Thrombotiques (CNR-MAT), Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Antoine, 75012 Paris, France; (C.R.); (P.C.)
- Urgences Néphrologiques et Transplantation Rénale, Hôpital Tenon, Assistance Publique-Hôpitaux de Paris, 75020 Paris, France
| | - Patricia Mariani
- Service de Microbiologie, Hôpital Robert Debré, Assistance Publique-Hôpitaux de Paris, 75019 Paris, France; (P.M.); (A.C.)
| | - Aurélie Cointe
- Service de Microbiologie, Hôpital Robert Debré, Assistance Publique-Hôpitaux de Paris, 75019 Paris, France; (P.M.); (A.C.)
| | - Antoine Dossier
- Service de Médecine Interne, Hôpital Bichat, Assistance Publique-Hôpitaux de Paris, 75018 Paris, France; (B.T.); (A.D.)
- Centre de Référence des Microangiopathies Thrombotiques (CNR-MAT), Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Antoine, 75012 Paris, France; (C.R.); (P.C.)
| | - Paul Coppo
- Centre de Référence des Microangiopathies Thrombotiques (CNR-MAT), Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Antoine, 75012 Paris, France; (C.R.); (P.C.)
- Service d’Hématologie, Hôpital Saint-Antoine, Assistance Publique-Hôpitaux de Paris, 75012 Paris, France
| | - Adrien Joseph
- Centre de Référence des Microangiopathies Thrombotiques (CNR-MAT), Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Antoine, 75012 Paris, France; (C.R.); (P.C.)
- Médecine Intensive Réanimation, Hôpital Saint Louis, Assistance Publique-Hôpitaux de Paris, 75010 Paris, France
- Centre de Recherche des Cordeliers, Équipe Labellisée par la Ligue Contre le Cancer, Inserm U1138, Université de Paris, Sorbonne Université, 75006 Paris, France
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Nguyen TTN, Koerdt SN, Gerke V. Plasma membrane phosphatidylinositol (4,5)-bisphosphate promotes Weibel-Palade body exocytosis. Life Sci Alliance 2020; 3:3/11/e202000788. [PMID: 32826291 PMCID: PMC7442956 DOI: 10.26508/lsa.202000788] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 08/14/2020] [Accepted: 08/14/2020] [Indexed: 01/26/2023] Open
Abstract
Phosphatidylinositol (4,5)-bisphosphate transiently accumulates at sites of Weibel–Palade body–plasma membrane fusion and promotes agonist-evoked exocytosis of endothelial von-Willebrand factor. Weibel–Palade bodies (WPB) are specialized secretory organelles of endothelial cells that control vascular hemostasis by regulated, Ca2+-dependent exocytosis of the coagulation-promoting von-Willebrand factor. Some proteins of the WPB docking and fusion machinery have been identified but a role of membrane lipids in regulated WPB exocytosis has so far remained elusive. We show here that the plasma membrane phospholipid composition affects Ca2+-dependent WPB exocytosis and von-Willebrand factor release. Phosphatidylinositol (4,5)-bisphosphate [PI(4,5)P2] becomes enriched at WPB–plasma membrane contact sites at the time of fusion, most likely downstream of phospholipase D1-mediated production of phosphatidic acid (PA) that activates phosphatidylinositol 4-phosphate (PI4P) 5-kinase γ. Depletion of plasma membrane PI(4,5)P2 or down-regulation of PI4P 5-kinase γ interferes with histamine-evoked and Ca2+-dependent WPB exocytosis and a mutant PI4P 5-kinase γ incapable of binding PA affects WPB exocytosis in a dominant-negative manner. This indicates that a unique PI(4,5)P2-rich environment in the plasma membrane governs WPB fusion possibly by providing interaction sites for WPB-associated docking factors.
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Affiliation(s)
- Tu Thi Ngoc Nguyen
- Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, University of Münster, Münster, Germany
| | - Sophia N Koerdt
- Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, University of Münster, Münster, Germany
| | - Volker Gerke
- Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, University of Münster, Münster, Germany
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Barisano D, Frohman MA. Roles for Phospholipase D1 in the Tumor Microenvironment. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1259:77-87. [PMID: 32578172 DOI: 10.1007/978-3-030-43093-1_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
The lipid-modifying signal transduction enzyme phospholipase D (PLD) has been proposed to have roles in oncogenic processes for well-on 30 years, with most of the early literature focused on potential functions for PLD in the biology of the tumor cells themselves. While such roles remain under investigation, evidence has also now been generated to support additional roles for PLD, in particular PLD1, in the tumor microenvironment, including effects on neoangiogenesis, the supply of nutrients, interactions of platelets with circulating cancer cells, the response of the immune system, and exosome biology. Here, we review these lines of investigation, accompanied by a discussion of the limitations of the existing studies and some cautionary notes regarding the study and interpretation of PLD function using model systems.
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Affiliation(s)
- Daniela Barisano
- Center for Developmental Genetics and the Department of Pharmacological Sciences, Stony Brook University School of Medicine, Stony Brook, NY, USA
| | - Michael A Frohman
- Center for Developmental Genetics and the Department of Pharmacological Sciences, Stony Brook University School of Medicine, Stony Brook, NY, USA.
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Joseph A, Cointe A, Mariani Kurkdjian P, Rafat C, Hertig A. Shiga Toxin-Associated Hemolytic Uremic Syndrome: A Narrative Review. Toxins (Basel) 2020; 12:E67. [PMID: 31973203 PMCID: PMC7076748 DOI: 10.3390/toxins12020067] [Citation(s) in RCA: 100] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 01/13/2020] [Accepted: 01/17/2020] [Indexed: 01/28/2023] Open
Abstract
The severity of human infection by one of the many Shiga toxin-producing Escherichia coli (STEC) is determined by a number of factors: the bacterial genome, the capacity of human societies to prevent foodborne epidemics, the medical condition of infected patients (in particular their hydration status, often compromised by severe diarrhea), and by our capacity to devise new therapeutic approaches, most specifically to combat the bacterial virulence factors, as opposed to our current strategies that essentially aim to palliate organ deficiencies. The last major outbreak in 2011 in Germany, which killed more than 50 people in Europe, was evidence that an effective treatment was still lacking. Herein, we review the current knowledge of STEC virulence, how societies organize the prevention of human disease, and how physicians treat (and, hopefully, will treat) its potentially fatal complications. In particular, we focus on STEC-induced hemolytic and uremic syndrome (HUS), where the intrusion of toxins inside endothelial cells results in massive cell death, activation of the coagulation within capillaries, and eventually organ failure.
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Affiliation(s)
- Adrien Joseph
- Department of Nephrology, AP-HP, Hôpital Tenon, F-75020 Paris, France; (A.J.); (C.R.)
| | - Aurélie Cointe
- Department of Microbiology, AP-HP, Hôpital Robert Debré, F-75019 Paris, France; (A.C.); (P.M.K.)
| | | | - Cédric Rafat
- Department of Nephrology, AP-HP, Hôpital Tenon, F-75020 Paris, France; (A.J.); (C.R.)
| | - Alexandre Hertig
- Department of Renal Transplantation, Sorbonne Université, AP-HP, Hôpital Pitié Salpêtrière, F-75013 Paris, France
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Lenzi C, Stevens J, Osborn D, Hannah MJ, Bierings R, Carter T. Synaptotagmin 5 regulates Ca 2+-dependent Weibel-Palade body exocytosis in human endothelial cells. J Cell Sci 2019; 132:jcs.221952. [PMID: 30659119 DOI: 10.1242/jcs.221952] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 01/09/2019] [Indexed: 12/11/2022] Open
Abstract
Elevations of intracellular free Ca2+ concentration ([Ca2+]i) are a potent trigger for Weibel-Palade body (WPB) exocytosis and secretion of von Willebrand factor (VWF) from endothelial cells; however, the identity of WPB-associated Ca2+-sensors involved in transducing acute increases in [Ca2+]i into granule exocytosis remains unknown. Here, we show that synaptotagmin 5 (SYT5) is expressed in human umbilical vein endothelial cells (HUVECs) and is recruited to WPBs to regulate Ca2+-driven WPB exocytosis. Western blot analysis of HUVECs identified SYT5 protein, and exogenously expressed SYT5-mEGFP localised almost exclusively to WPBs. shRNA-mediated knockdown of endogenous SYT5 (shSYT5) reduced the rate and extent of histamine-evoked WPB exocytosis and reduced secretion of the WPB cargo VWF-propeptide (VWFpp). The shSYT5-mediated reduction in histamine-evoked WPB exocytosis was prevented by expression of shRNA-resistant SYT5-mCherry. Overexpression of SYT5-EGFP increased the rate and extent of histamine-evoked WPB exocytosis, and increased secretion of VWFpp. Expression of a Ca2+-binding defective SYT5 mutant (SYT5-Asp197Ser-EGFP) mimicked depletion of endogenous SYT5. We identify SYT5 as a WPB-associated Ca2+ sensor regulating Ca2+-dependent secretion of stored mediators from vascular endothelial cells.
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Affiliation(s)
- Camille Lenzi
- Molecular and Clinical Sciences Research Institute, St George's, University of London, London SW18 ORE, UK
| | | | - Daniel Osborn
- Molecular and Clinical Sciences Research Institute, St George's, University of London, London SW18 ORE, UK
| | - Matthew J Hannah
- Microbiology Services Colindale, Public Health England, London, NW9 5EQ, UK
| | - Ruben Bierings
- Plasma Proteins, Sanquin Research and Landsteiner Laboratory, Academic Medical Centre, University of Amsterdam, 1006 AD Amsterdam, PO Box 9190, The Netherlands
| | - Tom Carter
- Molecular and Clinical Sciences Research Institute, St George's, University of London, London SW18 ORE, UK
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Schillemans M, Karampini E, Kat M, Bierings R. Exocytosis of Weibel-Palade bodies: how to unpack a vascular emergency kit. J Thromb Haemost 2019; 17:6-18. [PMID: 30375718 PMCID: PMC7379738 DOI: 10.1111/jth.14322] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Indexed: 01/17/2023]
Abstract
The blood vessel wall has a number of self-healing properties, enabling it to minimize blood loss and prevent or overcome infections in the event of vascular trauma. Endothelial cells prepackage a cocktail of hemostatic, inflammatory and angiogenic mediators in their unique secretory organelles, the Weibel-Palade bodies (WPBs), which can be immediately released on demand. Secretion of their contents into the vascular lumen through a process called exocytosis enables the endothelium to actively participate in the arrest of bleeding and to slow down and direct leukocytes to areas of inflammation. Owing to their remarkable elongated morphology and their secretory contents, which span the entire size spectrum of small chemokines all the way up to ultralarge von Willebrand factor multimers, WPBs constitute an ideal model system for studying the molecular mechanisms of secretory organelle biogenesis, exocytosis, and content expulsion. Recent studies have now shown that, during exocytosis, WPBs can undergo several distinct modes of fusion, and can utilize fundamentally different mechanisms to expel their contents. In this article, we discuss recent advances in our understanding of the composition of the WPB exocytotic machinery and how, because of its configuration, it is able to support WPB release in its various forms.
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Affiliation(s)
- M. Schillemans
- Molecular and Cellular HemostasisSanquin Research and Landsteiner LaboratoryAmsterdam UMCUniversity of AmsterdamAmsterdamthe Netherlands
| | - E. Karampini
- Molecular and Cellular HemostasisSanquin Research and Landsteiner LaboratoryAmsterdam UMCUniversity of AmsterdamAmsterdamthe Netherlands
| | - M. Kat
- Molecular and Cellular HemostasisSanquin Research and Landsteiner LaboratoryAmsterdam UMCUniversity of AmsterdamAmsterdamthe Netherlands
| | - R. Bierings
- Molecular and Cellular HemostasisSanquin Research and Landsteiner LaboratoryAmsterdam UMCUniversity of AmsterdamAmsterdamthe Netherlands
- HematologyErasmus University Medical CenterRotterdamthe Netherlands
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McCormack JJ, Lopes da Silva M, Ferraro F, Patella F, Cutler DF. Weibel-Palade bodies at a glance. J Cell Sci 2017; 130:3611-3617. [PMID: 29093059 DOI: 10.1242/jcs.208033] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The vascular environment can rapidly alter, and the speed with which responses to both physiological and pathological changes are required necessitates the existence of a highly responsive system. The endothelium can quickly deliver bioactive molecules by regulated exocytosis of its secretory granules, the Weibel-Palade bodies (WPBs). WPBs include proteins that initiate both haemostasis and inflammation, as well those that modulate blood pressure and angiogenesis. WPB formation is driven by von Willebrand factor, their most abundant protein, which controls both shape and size of WPBs. WPB are generated in a range of sizes, with the largest granules over ten times the size of the smallest. In this Cell Science at a Glance and the accompanying poster, we discuss the emerging mechanisms by which WPB size is controlled and how this affects the ability of this organelle to modulate haemostasis. We will also outline the different modes of exocytosis and their polarity that are currently being explored, and illustrate that these large secretory organelles provide a model for how elements of secretory granule biogenesis and exocytosis cooperate to support a complex and diverse set of functions.
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Affiliation(s)
- Jessica J McCormack
- MRC Laboratory of Molecular Cell Biology, University College London, Gower Street, London, WC1E6BT, UK
| | - Mafalda Lopes da Silva
- MRC Laboratory of Molecular Cell Biology, University College London, Gower Street, London, WC1E6BT, UK
| | - Francesco Ferraro
- MRC Laboratory of Molecular Cell Biology, University College London, Gower Street, London, WC1E6BT, UK
| | - Francesca Patella
- MRC Laboratory of Molecular Cell Biology, University College London, Gower Street, London, WC1E6BT, UK
| | - Daniel F Cutler
- MRC Laboratory of Molecular Cell Biology, University College London, Gower Street, London, WC1E6BT, UK
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Biesemann A, Gorontzi A, Barr F, Gerke V. Rab35 protein regulates evoked exocytosis of endothelial Weibel-Palade bodies. J Biol Chem 2017; 292:11631-11640. [PMID: 28566286 PMCID: PMC5512060 DOI: 10.1074/jbc.m116.773333] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 05/15/2017] [Indexed: 12/22/2022] Open
Abstract
Weibel–Palade bodies (WPB) are secretory organelles of endothelial cells that undergo evoked exocytosis following intracellular Ca2+ or cAMP elevation, thereby supplying the vasculature with factors controlling hemostasis. Several cytosolic and membrane-associated proteins, including the Rab family members Rab3, Rab15, and Rab27a, have been implicated in regulating the acute exocytosis of WPB. Here, we carried out a genome-wide screen to identify Rab pathways affecting WPB exocytosis. Overexpression of a specific subset of Rab GTPase–activating proteins (RabGAPs) inhibited histamine-evoked, Ca2+-dependent WPB exocytosis, presumably by inactivating the target Rab GTPases. Among these RabGAPs, we concentrated on TBC1D10A and showed that the inhibitory effect depends on its GAP activity. We confirmed that Rab35 was a target Rab of TBC1D10A in human endothelial cells; Rab35 interacted with TBC1D10A, and expression of the GAP-insensitive Rab35(Q67A) mutant rescued the inhibitory effect of TBC1D10A overexpression on WPB exocytosis. Furthermore, knockdown of Rab35 and expression of a dominant-negative Rab35 mutant both inhibited histamine-evoked secretion of the WPB cargos von Willebrand factor and P-selectin. Pulldown and co-immunoprecipitation experiments identified the ArfGAP with coiled-coil, Ank repeat, and pleckstrin homology domain–containing protein ACAP2 as an Rab35 effector in endothelial cells, and depletion as well as overexpression approaches revealed that ACAP2 acts as a negative regulator of WPB exocytosis. Interestingly, a known ACAP2 target, the small GTPase Arf6, supported histamine-evoked WPB exocytosis, as shown by knockdown and overexpression of a dominant-negative Arf6 mutant. Our data identify Rab35 as a novel regulator of WPB exocytosis, most likely acting through the downstream effectors ACAP2 and Arf6.
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Affiliation(s)
- Anja Biesemann
- Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, University of Münster, D-48149 Münster, Germany
| | - Alexandra Gorontzi
- Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, University of Münster, D-48149 Münster, Germany
| | - Francis Barr
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Volker Gerke
- Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, University of Münster, D-48149 Münster, Germany.
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Geelen J, van den Biggelaar M, Linssen P, van der Velden T, Mertens K, Monnens L. The effect of shiga toxin on weibel-palade bodies in primary human endothelial cells. NEPHRON EXTRA 2014; 4:101-7. [PMID: 25177338 PMCID: PMC4130816 DOI: 10.1159/000363299] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Background/Aims Diarrhea-associated hemolytic uremic syndrome is associated with the presence of Shiga toxin (Stx1, Stx2 and several variants) in the circulation. The aim of this study is to examine the possible triggering effect of Stx1 on the exocytosis of Weibel-Palade bodies (WPbs). Methods Cultured human umbilical venous endothelial cells (HUVECs) and glomerular microvascular endothelial cells (GMVECs) were stimulated by thrombin and Stx1 in both static and flowing conditions. The amount of secreted von Willebrand factor (VWF) in the supernatant as well as the remaining intracellular fraction was determined. Results In HUVECs and in 2 out of 4 GMVECs, the stimulation of Stx1 in flow at 1 dyne/cm2 resulted in a decrease of intracellular VWF. This is contrary to the results of Stx1 applied in static conditions. At a higher flow rate of 5 dyne/cm2, no effect in GMVECs was observed. Conclusion Stx1 can contribute, via an effect on WPbs, to the exocytosis of WPbs in flow conditions in HUVECs and probably in GMVECs. This results in the release of VWF, suggesting an initiating role of the coagulation system in the pathogenesis.
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Affiliation(s)
- Joyce Geelen
- Department of Paediatric Nephrology, The Netherlands
| | - Maartje van den Biggelaar
- Department of Plasma Proteins, Sanquin Research, Amsterdam, The Netherlands ; Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht, The Netherlands
| | - Peter Linssen
- Central Hematology Laboratory, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | | | - Koen Mertens
- Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht, The Netherlands
| | - Leo Monnens
- Department of Paediatric Nephrology, The Netherlands
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cAMP-induced secretion of endothelial von Willebrand factor is regulated by a phosphorylation/dephosphorylation switch in annexin A2. Blood 2013; 122:1042-51. [PMID: 23757730 DOI: 10.1182/blood-2012-12-475251] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The large multimeric glyocoprotein von Willebrand factor (VWF) is a crucial component of both primary and secondary hemostasis. It is stored in secretory granules of vascular endothelial cells, the Weibel-Palade bodies (WPBs), and is released following stimulation by agonists that raise intracellular Ca(2+) or cyclic adenosine monophosphate (cAMP) levels. cAMP-induced exocytosis of WPBs requires protein kinase A activity, but downstream factors that are regulated by phosphorylation/dephosphorylation are not known. Here we identify the complex consisting of the lipid-binding protein annexin A2 (AnxA2) and S100A10 as such a factor. Knockdown and specific rescue approaches reveal that a functional AnxA2-S100A10 complex is required for the forskolin-induced, cAMP-dependent release of VWF. Forskolin triggers dephosphorylation of AnxA2 that is mediated by a calcineurin-like phosphatase and stabilizes the AnxA2-S100A10 complex, thereby promoting VWF release. Serine 11 of AnxA2 was identified as the target residue of this phosphorylation switch because a phosphomimicking mutation at this site prevents complex formation with S100A10 and, in contrast to wild-type or S11A-AnxA2, is unable to restore cAMP-dependent VWF secretion in AnxA2-depleted cells. Thus, complex formation of AnxA2 with S100A10 is a central regulatory mechanism in the acute release of VWF in response to cAMP-elevating agonists.
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