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El-Mansi S, Mitchell TP, Mobyen G, McKinnon TA, Miklavc P, Frick M, Nightingale TD. Myosin-1C augments secretion of von Willebrand factor by linking contractile actomyosin machinery to the plasma membrane. Blood Adv 2024:bloodadvances.2024012590. [PMID: 38669344 DOI: 10.1182/bloodadvances.2024012590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 04/15/2024] [Accepted: 04/16/2024] [Indexed: 04/28/2024] Open
Abstract
Blood endothelial cells control the hemostatic and inflammatory response by secreting von Willebrand factor (VWF) and P-selectin from storage organelles called Weibel-Palade bodies (WPB). Actin-associated motor proteins regulate this secretory pathway at multiple points. Prior to fusion, myosin Va forms a complex that anchors WPBs to peripheral actin structures allowing maturation of content. Post-fusion, an actomyosin ring/coat is recruited and compresses the WPB to forcibly expel the largest VWF multimers. Here we provide the first evidence for the involvement of class I myosins during regulated VWF secretion. We show that the unconventional myosin-1C (Myo1c) is recruited post-fusion via its pleckstrin homology domain in an actin-independent process. This provides a link between the actin ring and phosphatidylinositol 4,5-bisphosphate (PIP2) at the membrane of the fused organelle and is necessary to ensure maximal VWF secretion. This is an active process requiring Myo1c ATPase activity as inhibition of class I myosins using the inhibitor Pentachloropseudilin or expression of an ATPase deficient Myo1c rigor mutant perturbs the expulsion of VWF and alters the kinetics of the exocytic actin ring. These data offer a novel insight into the control of an essential physiological process and provide a new way in which it can be regulated.
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Affiliation(s)
| | | | | | | | - Pika Miklavc
- University of Salford, Manchester, United Kingdom
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2
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Bosseboeuf E, Chikh A, Chaker AB, Mitchell TP, Vignaraja D, Rajendrakumar R, Khambata RS, Nightingale TD, Mason JC, Randi AM, Ahluwalia A, Raimondi C. Neuropilin-1 interacts with VE-cadherin and TGFBR2 to stabilize adherens junctions and prevent activation of endothelium under flow. Sci Signal 2023; 16:eabo4863. [PMID: 37220183 PMCID: PMC7614756 DOI: 10.1126/scisignal.abo4863] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Accepted: 05/03/2023] [Indexed: 05/25/2023]
Abstract
Linear and disturbed flow differentially regulate gene expression, with disturbed flow priming endothelial cells (ECs) for a proinflammatory, atheroprone expression profile and phenotype. Here, we investigated the role of the transmembrane protein neuropilin-1 (NRP1) in ECs exposed to flow using cultured ECs, mice with an endothelium-specific knockout of NRP1, and a mouse model of atherosclerosis. We demonstrated that NRP1 was a constituent of adherens junctions that interacted with VE-cadherin and promoted its association with p120 catenin, stabilizing adherens junctions and inducing cytoskeletal remodeling in alignment with the direction of flow. We also showed that NRP1 interacted with transforming growth factor-β (TGF-β) receptor II (TGFBR2) and reduced the plasma membrane localization of TGFBR2 and TGF-β signaling. NRP1 knockdown increased the abundance of proinflammatory cytokines and adhesion molecules, resulting in increased leukocyte rolling and atherosclerotic plaque size. These findings describe a role for NRP1 in promoting endothelial function and reveal a mechanism by which NRP1 reduction in ECs may contribute to vascular disease by modulating adherens junction signaling and promoting TGF-β signaling and inflammation.
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Affiliation(s)
- Emy Bosseboeuf
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Centre of Cardiovascular Medicine and Devices, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Anissa Chikh
- Molecular and Clinical Sciences Research Institute, St. George’s, University of London, London SW17 0RE, UK
| | - Ahmed Bey Chaker
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Centre of Cardiovascular Medicine and Devices, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Tom P. Mitchell
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Centre for Microvascular Research, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Dhilakshani Vignaraja
- Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, London, W12 0NN, UK
| | - Ridhi Rajendrakumar
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Centre of Cardiovascular Medicine and Devices, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Rayomand S. Khambata
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Centre of Cardiovascular Medicine and Devices, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Thomas D. Nightingale
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Centre for Microvascular Research, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Justin C. Mason
- Vascular Sciences, National Heart & Lung Institute, Faculty of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London, W12 0HS, UK
| | - Anna M. Randi
- Vascular Sciences, National Heart & Lung Institute, Faculty of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London, W12 0HS, UK
| | - Amrita Ahluwalia
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Centre of Cardiovascular Medicine and Devices, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Claudio Raimondi
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Centre of Cardiovascular Medicine and Devices, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
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3
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El-Mansi S, Robinson CL, Kostelnik KB, McCormack JJ, Mitchell TP, Lobato-Márquez D, Rajeeve V, Cutillas P, Cutler DF, Mostowy S, Nightingale TD. Proximity proteomics identifies septins and PAK2 as decisive regulators of actomyosin-mediated expulsion of von Willebrand factor. Blood 2023; 141:930-944. [PMID: 36564030 PMCID: PMC10023740 DOI: 10.1182/blood.2022017419] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 11/07/2022] [Accepted: 11/27/2022] [Indexed: 12/25/2022] Open
Abstract
In response to tissue injury, within seconds the ultra-large glycoprotein von Willebrand factor (VWF) is released from endothelial storage organelles (Weibel-Palade bodies) into the lumen of the blood vasculature, where it leads to the recruitment of platelets. The marked size of VWF multimers represents an unprecedented burden on the secretory machinery of endothelial cells (ECs). ECs have evolved mechanisms to overcome this, most notably an actomyosin ring that forms, contracts, and squeezes out its unwieldy cargo. Inhibiting the formation or function of these structures represents a novel therapeutic target for thrombotic pathologies, although characterizing proteins associated with such a dynamic process has been challenging. We have combined APEX2 proximity labeling with an innovative dual loss-of-function screen to identify proteins associated with actomyosin ring function. We show that p21 activated kinase 2 (PAK2) recruits septin hetero-oligomers, a molecular interaction that forms a ring around exocytic sites. This cascade of events controls actomyosin ring function, aiding efficient exocytic release. Genetic or pharmacological inhibition of PAK2 or septins led to inefficient release of VWF and a failure to form platelet-catching strings. This new molecular mechanism offers additional therapeutic targets for the control of thrombotic disease and is highly relevant to other secretory systems that employ exocytic actomyosin machinery.
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Affiliation(s)
- Sammy El-Mansi
- Centre for Microvascular Research, William Harvey Research Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Christopher L. Robinson
- Centre for Microvascular Research, William Harvey Research Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Katja B. Kostelnik
- Centre for Microvascular Research, William Harvey Research Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Jessica J. McCormack
- MRC Laboratory of Molecular Cell Biology, University College London, London, United Kingdom
| | - Tom P. Mitchell
- Centre for Microvascular Research, William Harvey Research Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Damián Lobato-Márquez
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Vinothini Rajeeve
- Cell Signalling & Proteomics Group, Barts Cancer Institute, Queen Mary University of London, London, United Kingdom
| | - Pedro Cutillas
- Cell Signalling & Proteomics Group, Barts Cancer Institute, Queen Mary University of London, London, United Kingdom
| | - Daniel F. Cutler
- MRC Laboratory of Molecular Cell Biology, University College London, London, United Kingdom
| | - Serge Mostowy
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Thomas D. Nightingale
- Centre for Microvascular Research, William Harvey Research Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
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Reglero-Real N, Pérez-Gutiérrez L, Yoshimura A, Rolas L, Garrido-Mesa J, Barkaway A, Pickworth C, Saleeb RS, Gonzalez-Nuñez M, Austin-Williams SN, Cooper D, Vázquez-Martínez L, Fu T, De Rossi G, Golding M, Benoit-Voisin M, Boulanger CM, Kubota Y, Muller WA, Tooze SA, Nightingale TD, Collinson L, Perretti M, Aksoy E, Nourshargh S. Autophagy modulates endothelial junctions to restrain neutrophil diapedesis during inflammation. Immunity 2021; 54:1989-2004.e9. [PMID: 34363750 PMCID: PMC8459396 DOI: 10.1016/j.immuni.2021.07.012] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 05/13/2021] [Accepted: 07/13/2021] [Indexed: 02/06/2023]
Abstract
The migration of neutrophils from the blood circulation to sites of infection or injury is a key immune response and requires the breaching of endothelial cells (ECs) that line the inner aspect of blood vessels. Unregulated neutrophil transendothelial cell migration (TEM) is pathogenic, but the molecular basis of its physiological termination remains unknown. Here, we demonstrated that ECs of venules in inflamed tissues exhibited a robust autophagic response that was aligned temporally with the peak of neutrophil trafficking and was strictly localized to EC contacts. Genetic ablation of EC autophagy led to excessive neutrophil TEM and uncontrolled leukocyte migration in murine inflammatory models, while pharmacological induction of autophagy suppressed neutrophil infiltration into tissues. Mechanistically, autophagy regulated the remodeling of EC junctions and expression of key EC adhesion molecules, facilitating their intracellular trafficking and degradation. Collectively, we have identified autophagy as a modulator of EC leukocyte trafficking machinery aimed at terminating physiological inflammation. Inflamed venular ECs exhibit an autophagic response that localizes to EC contacts EC ATG5 deficiency promotes excessive and faster neutrophil TEM Ablation of EC autophagy increases cell surface expression of adhesion molecules Non-canonical autophagy operates in inflamed ECs and controls neutrophil migration
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Affiliation(s)
- Natalia Reglero-Real
- Centre for Microvascular Research, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK.
| | - Lorena Pérez-Gutiérrez
- Centre for Microvascular Research, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK
| | - Azumi Yoshimura
- Electron Microscopy Science Technology Platform, Francis Crick Institute, London NW1 1AT, UK
| | - Loïc Rolas
- Centre for Microvascular Research, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK
| | - José Garrido-Mesa
- Centre for Biochemical Pharmacology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK
| | - Anna Barkaway
- Centre for Microvascular Research, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK
| | - Catherine Pickworth
- Centre for Microvascular Research, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK
| | - Rebeca S Saleeb
- Centre for Microvascular Research, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK
| | - Maria Gonzalez-Nuñez
- Centre for Biochemical Pharmacology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK
| | - Shani N Austin-Williams
- Centre for Biochemical Pharmacology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK
| | - Dianne Cooper
- Centre for Biochemical Pharmacology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK; Centre for Inflammation and Therapeutic Innovation, Queen Mary University of London, London EC1M 6BQ, UK
| | - Laura Vázquez-Martínez
- Centre for Microvascular Research, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK
| | - Tao Fu
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Giulia De Rossi
- Department of Cell Biology, Institute of Ophthalmology, University College London, London EC1V9EL, UK
| | - Matthew Golding
- Centre for Microvascular Research, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK
| | - Mathieu Benoit-Voisin
- Centre for Microvascular Research, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK
| | | | - Yoshiaki Kubota
- Department of Anatomy, Keio University School of Medicine, Tokyo 113-0022, Japan
| | - William A Muller
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Sharon A Tooze
- Molecular Cell Biology of Autophagy Laboratory, Francis Crick Institute, London NW1 1AT, UK
| | - Thomas D Nightingale
- Centre for Microvascular Research, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK
| | - Lucy Collinson
- Electron Microscopy Science Technology Platform, Francis Crick Institute, London NW1 1AT, UK
| | - Mauro Perretti
- Centre for Biochemical Pharmacology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK; Centre for Inflammation and Therapeutic Innovation, Queen Mary University of London, London EC1M 6BQ, UK
| | - Ezra Aksoy
- Centre for Biochemical Pharmacology, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK
| | - Sussan Nourshargh
- Centre for Microvascular Research, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK; Centre for Inflammation and Therapeutic Innovation, Queen Mary University of London, London EC1M 6BQ, UK.
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5
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Kostelnik KB, Barker A, Schultz C, Mitchell TP, Rajeeve V, White IJ, Aurrand-Lions M, Nourshargh S, Cutillas P, Nightingale TD. Dynamic trafficking and turnover of JAM-C is essential for endothelial cell migration. PLoS Biol 2019; 17:e3000554. [PMID: 31790392 PMCID: PMC6907879 DOI: 10.1371/journal.pbio.3000554] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [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: 07/15/2019] [Revised: 12/12/2019] [Accepted: 11/14/2019] [Indexed: 12/26/2022] Open
Abstract
Junctional complexes between endothelial cells form a dynamic barrier that hinders passive diffusion of blood constituents into interstitial tissues. Remodelling of junctions is an essential process during leukocyte trafficking, vascular permeability, and angiogenesis. However, for many junctional proteins, the mechanisms of junctional remodelling have yet to be determined. Here, we used receptor mutagenesis, horseradish peroxidase (HRP), and ascorbate peroxidase 2 (APEX-2) proximity labelling, alongside light and electron microscopy (EM), to map the intracellular trafficking routes of junctional adhesion molecule-C (JAM-C). We found that JAM-C cotraffics with receptors associated with changes in permeability such as vascular endothelial cadherin (VE-Cadherin) and neuropilin (NRP)-1 and 2, but not with junctional proteins associated with the transmigration of leukocytes. Dynamic JAM-C trafficking and degradation are necessary for junctional remodelling during cell migration and angiogenesis. By identifying new potential trafficking machinery, we show that a key point of regulation is the ubiquitylation of JAM-C by the E3 ligase Casitas B-lineage lymphoma (CBL), which controls the rate of trafficking versus lysosomal degradation.
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Affiliation(s)
- Katja B. Kostelnik
- Centre for Microvascular Research, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom
| | - Amy Barker
- Centre for Microvascular Research, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom
| | - Christopher Schultz
- Centre for Microvascular Research, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom
| | - Tom P. Mitchell
- Centre for Microvascular Research, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom
| | - Vinothini Rajeeve
- Cell Signalling & Proteomics Group, Barts Cancer Institute, Queen Mary University of London, London, United Kingdom
| | - Ian J. White
- MRC Laboratory of Molecular Cell Biology, University College London, London, United Kingdom
| | - Michel Aurrand-Lions
- Aix Marseille University, CNRS, INSERM, Institut Paoli-Calmettes, CRCM, Marseille, France
| | - Sussan Nourshargh
- Centre for Microvascular Research, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom
| | - Pedro Cutillas
- Cell Signalling & Proteomics Group, Barts Cancer Institute, Queen Mary University of London, London, United Kingdom
| | - Thomas D. Nightingale
- Centre for Microvascular Research, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom
- * E-mail:
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Stevenson NL, White IJ, McCormack JJ, Robinson C, Cutler DF, Nightingale TD. Clathrin-mediated post-fusion membrane retrieval influences the exocytic mode of endothelial Weibel-Palade bodies. J Cell Sci 2017; 130:2591-2605. [PMID: 28674075 PMCID: PMC5558267 DOI: 10.1242/jcs.200840] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 06/10/2017] [Indexed: 01/15/2023] Open
Abstract
Weibel-Palade bodies (WPBs), the storage organelles of endothelial cells, are essential to normal haemostatic and inflammatory responses. Their major constituent protein is von Willebrand factor (VWF) which, following stimulation with secretagogues, is released into the blood vessel lumen as large platelet-catching strings. This exocytosis changes the protein composition of the cell surface and also results in a net increase in the amount of plasma membrane. Compensatory endocytosis is thought to limit changes in cell size and retrieve fusion machinery and other misplaced integral membrane proteins following exocytosis; however, little is known about the extent, timing, mechanism and precise function of compensatory endocytosis in endothelial cells. Using biochemical assays, live-cell imaging and correlative spinning-disk microscopy and transmission electron microscopy assays we provide the first in-depth high-resolution characterisation of this process. We provide a model of compensatory endocytosis based on rapid clathrin- and dynamin-mediated retrieval. Inhibition of this process results in a change of exocytic mode: WPBs then fuse with previously fused WPBs rather than the plasma membrane, leading, in turn, to the formation of structurally impaired tangled VWF strings. This article has an associated First Person interview with the first authors of the paper. Summary: Compensatory endocytosis plays key roles in Weibel-Palade body exocytosis. Inhibition of this process results in a change of exocytic mode and the release of von Willebrand factor as tangled strings.
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Affiliation(s)
- Nicola L Stevenson
- MRC Cell Biology Unit, Laboratory of Molecular Cell Biology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Ian J White
- MRC Cell Biology Unit, Laboratory of Molecular Cell Biology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Jessica J McCormack
- MRC Cell Biology Unit, Laboratory of Molecular Cell Biology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Christopher Robinson
- Centre for Microvascular Research, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Daniel F Cutler
- MRC Cell Biology Unit, Laboratory of Molecular Cell Biology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Thomas D Nightingale
- Centre for Microvascular Research, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
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Nightingale TD, Cutler DF, Cramer LP. Actin coats and rings promote regulated exocytosis. Trends Cell Biol 2012; 22:329-37. [DOI: 10.1016/j.tcb.2012.03.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2012] [Revised: 03/21/2012] [Accepted: 03/22/2012] [Indexed: 11/16/2022]
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Rojo Pulido I, Nightingale TD, Darchen F, Seabra MC, Cutler DF, Gerke V. Myosin Va acts in concert with Rab27a and MyRIP to regulate acute von-Willebrand factor release from endothelial cells. Traffic 2011; 12:1371-82. [PMID: 21740491 DOI: 10.1111/j.1600-0854.2011.01248.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Von-Willebrand factor (vWF) is a highly multimerized hemostatic glycoprotein that is stored in endothelial Weibel-Palade bodies (WPB) and secreted upon cell stimulation to act in recruiting platelets to sites of vessel injury. Only fully matured multimeric vWF represents an efficient anchor for platelets, and endothelial cells have developed mechanisms to prevent release of immature vWF. Full maturation of vWF occurs within WPB following their translocation from a perinuclear site of emergence at the trans-Golgi network (TGN) to the cell periphery. The WPB-associated small GTPase Rab27a is involved in restricting immature WPB exocytosis and we searched for links between Rab27a and the actin cytoskeleton that could anchor WPB inside endothelial cells until they are fully matured. We here identify myosin Va as such link. Myosin Va forms a tripartite complex with Rab27a and its effector MyRIP and depletion of or dominant-negative interference with myosin Va leads to an increase in the ratio of perinuclear to more peripheral WPB. Concomitantly, myosin Va depletion results in an elevated secretion of less-oligomeric vWF from histamine-stimulated endothelial cells. These results indicate that a Rab27a/MyRIP/myosin Va complex is involved in linking WPB to the peripheral actin cytoskeleton of endothelial cells to allow full maturation and prevent premature secretion of vWF.
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Affiliation(s)
- Inés Rojo Pulido
- Institute of Medical Biochemistry, Centre for Molecular Biology of Inflammation, University of Münster, Münster, Germany
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Nightingale TD, White IJ, Doyle EL, Turmaine M, Harrison-Lavoie KJ, Webb KF, Cramer LP, Cutler DF. Actomyosin II contractility expels von Willebrand factor from Weibel-Palade bodies during exocytosis. ACTA ACUST UNITED AC 2011; 194:613-29. [PMID: 21844207 PMCID: PMC3160584 DOI: 10.1083/jcb.201011119] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
High-resolution microscopy reveals how discrete actin cytoskeletal functions inhibit or promote specific exocytic steps during regulated secretion. The study of actin in regulated exocytosis has a long history with many different results in numerous systems. A major limitation on identifying precise mechanisms has been the paucity of experimental systems in which actin function has been directly assessed alongside granule content release at distinct steps of exocytosis of a single secretory organelle with sufficient spatiotemporal resolution. Using dual-color confocal microscopy and correlative electron microscopy in human endothelial cells, we visually distinguished two sequential steps of secretagogue-stimulated exocytosis: fusion of individual secretory granules (Weibel–Palade bodies [WPBs]) and subsequent expulsion of von Willebrand factor (VWF) content. Based on our observations, we conclude that for fusion, WPBs are released from cellular sites of actin anchorage. However, once fused, a dynamic ring of actin filaments and myosin II forms around the granule, and actomyosin II contractility squeezes VWF content out into the extracellular environment. This study therefore demonstrates how discrete actin cytoskeleton functions within a single cellular system explain actin filament–based prevention and promotion of specific exocytic steps during regulated secretion.
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Affiliation(s)
- Thomas D Nightingale
- Medical Research Council Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, England, UK
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Michaux G, Dyer CEF, Nightingale TD, Gallaud E, Nurrish S, Cutler DF. A role for Rab10 in von Willebrand factor release discovered by an AP-1 interactor screen in C. elegans. J Thromb Haemost 2011; 9:392-401. [PMID: 21070595 DOI: 10.1111/j.1538-7836.2010.04138.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Endothelial von Willebrand factor (VWF) mediates platelet adhesion and acts as a protective chaperone to clotting factor VIII. Rapid release of highly multimerized VWF is particularly effective in promoting hemostasis. To produce this protein, an elaborate biogenesis is required, culminating at the trans-Golgi network (TGN) in storage within secretory granules called Weibel-Palade bodies (WPB). Failure to correctly form these organelles can lead to uncontrolled secretion of low-molecular-weight multimers of VWF. The TGN-associated adaptor AP-1 and its interactors clathrin, aftiphilin and γ-synergin are essential to initial WPB formation at the Golgi apparatus, and thus to VWF storage and secretion. OBJECTIVES To identify new proteins implicated in VWF storage and/or secretion. METHODS A genomewide RNA interference (RNAi) screen was performed in the Nematode C. elegans to identify new AP-1 genetic interactors. RESULTS The small GTPase Rab10 was found to genetically interact with a partial loss of function of AP-1 in C. elegans. We investigated Rab10 in human primary umbilical vein endothelial cells (HUVECs). We report that Rab10 is enriched at the Golgi apparatus, where WPB are formed, and that in cells where Rab10 expression has been suppressed by siRNA, VWF secretion is altered: the amount of rapidly released VWF was significantly reduced. We also found that Rab8A has a similar function. CONCLUSION Rab10 and Rab8A are new cytoplasmic factors implicated in WPB biogenesis that play a role in generating granules that can rapidly respond to secretagogue.
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Affiliation(s)
- G Michaux
- INSERM Avenir team Trafic intracellulaire et polarité chez C. elegans, Rennes, France.
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Nightingale TD, Pattni K, Hume AN, Seabra MC, Cutler DF. Rab27a and MyRIP regulate the amount and multimeric state of VWF released from endothelial cells. Blood 2009; 113:5010-8. [PMID: 19270261 PMCID: PMC2686148 DOI: 10.1182/blood-2008-09-181206] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2008] [Accepted: 02/15/2009] [Indexed: 11/20/2022] Open
Abstract
Endothelial cells contain cigar-shaped secretory organelles called Weibel-Palade bodies (WPBs) that play a crucial role in both hemostasis and the initiation of inflammation. The major cargo protein of WPBs is von Willebrand factor (VWF). In unstimulated cells, this protein is stored in a highly multimerized state coiled into protein tubules, but after secretagogue stimulation and exocytosis it unfurls, under shear force, as long platelet-binding strings. Small GTPases of the Rab family play a key role in organelle function. Using siRNA depletion in primary endothelial cells, we have identified a role for the WPB-associated Rab27a and its effector MyRIP. Both these proteins are present on only mature WPBs, and this rab/effector complex appears to anchor these WPBs to peripheral actin. Depletion of either the Rab or its effector results in a loss of peripheral WPB localization, and this destabilization is coupled with an increase in both basal and stimulated secretion. The VWF released from Rab27a-depleted cells is less multimerized, and the VWF strings seen under flow are shorter. Our results indicate that this Rab/effector complex controls peripheral distribution and prevents release of incompletely processed WPB content.
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Affiliation(s)
- Thomas D Nightingale
- Medical Research Council Laboratory of Molecular Cell Biology, Cell Biology Unit, Department of Cell and Developmental Biology, University College London, London, United Kingdom. [corrected]
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Nightingale TD, Frayne MEF, Clasper S, Banerji S, Jackson DG. A mechanism of sialylation functionally silences the hyaluronan receptor LYVE-1 in lymphatic endothelium. J Biol Chem 2008; 284:3935-45. [PMID: 19033446 DOI: 10.1074/jbc.m805105200] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The major lymphatic endothelial hyaluronan receptor LYVE-1, a Link superfamily glycoprotein similar to the hyaluronan-binding/inflammatory leukocyte homing receptor CD44, was initially implicated in hyaluronan (HA)-mediated cell adhesion and lymph-borne hyaluronan metabolism. However, the apparently normal phenotype of Lyve-1 knock-out mice and the recent demonstration that the receptor undergoes cytokine-induced endocytosis independent of HA uptake have cast doubt on such functions. Here we present new data that reconcile these anomalies by showing that LYVE-1 is functionally "silenced" in a cell-specific fashion by autoinhibitory glycosylation. We demonstrate that LYVE-1 transfected in HEK 293T fibroblasts and Jurkat T cells is competent to bind HA, whereas the endogenous receptor in cultured lymphatic endothelial cells or the receptor transfected in Chinese hamster ovary and HeLa cells is not. Moreover, through a combination of mutagenesis and functional analysis in HEK 293T fibroblasts and glycosylation-defective Chinese hamster ovary cell lines, we reveal that the inhibitory mechanism is reversible and is exerted by terminal sialylation, most likely through alpha2-3 or alpha2-6 linkage to O-glycans. Finally, we provide evidence that the mechanism operates in vivo by showing that native LYVE-1 in primary lymphatic endothelial cells is extensively sialylated and that HA binding can be reactivated by neuraminidase treatment of the soluble ectodomain. These results reveal unexpected complexity in the regulation of LYVE-1 function and raise the possibility that this receptor, like CD44, may become active after appropriate unmasking in vivo.
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Affiliation(s)
- Thomas D Nightingale
- Medical Research Council, Human Immunology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, United Kingdom
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Lui-Roberts WWY, Ferraro F, Nightingale TD, Cutler DF. Aftiphilin and gamma-synergin are required for secretagogue sensitivity of Weibel-Palade bodies in endothelial cells. Mol Biol Cell 2008; 19:5072-81. [PMID: 18815278 DOI: 10.1091/mbc.e08-03-0301] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Formation of secretory organelles requires the coupling of cargo selection to targeting into the correct exocytic pathway. Although the assembly of regulated secretory granules is driven in part by selective aggregation and retention of content, we recently reported that adaptor protein-1 (AP-1) recruitment of clathrin is essential to the initial formation of Weibel-Palade bodies (WPBs) at the trans-Golgi network. A selective co-aggregation process might include recruitment of components required for targeting to the regulated secretory pathway. However, we find that acquisition of the regulated secretory phenotype by WPBs in endothelial cells is coupled to but can be separated from formation of the distinctive granule core by ablation of the AP-1 effectors aftiphilin and gamma-synergin. Their depletion by small interfering RNA leads to WPBs that fail to respond to secretagogue and release their content in an unregulated manner. We find that these non-responsive WPBs have density, markers of maturation, and highly multimerized von Willebrand factor similar to those of wild-type granules. Thus, by also recruiting aftiphilin/gamma-synergin in addition to clathrin, AP-1 coordinates formation of WPBs with their acquisition of a regulated secretory phenotype.
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Affiliation(s)
- Winnie W Y Lui-Roberts
- MRC Laboratory of Molecular Cell Biology, Cell Biology Unit and Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom
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Abstract
Weibel-Palade bodies (WPBs) are secretory organelles used for post-synthesis storage in endothelial cells that can, very rapidly, be triggered to release their contents. They carry a variety of bioactive molecules that are needed to mount a rapid response to the complex environment of cells that line blood vessels. They store factors that are essential to haemostasis and inflammation, as well as factors that modulate vascular tonicity and angiogenesis. The number of WPBs and their precise content vary between endothelial tissues, reflecting their differing physiological circumstances. The particular functional demands of the highly multimerised haemostatic protein von Willebrand Factor (VWF), which is stored in WPBs as tubules until release, are responsible for the cigar shape of these granules. How VWF tubules drive the formation of these uniquely shaped organelles, and how WPB density increases during maturation, has recently been revealed by EM analysis using high-pressure freezing and freeze substitution. In addition, an AP1/clathrin coat has been found to be essential to WPB formation. Following recruitment of cargo at the TGN, there is a second wave of recruitment that delivers integral and peripheral membrane proteins to WPBs, some of which is AP3 dependent.
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Affiliation(s)
- Daniel J Metcalf
- MRC Laboratory of Molecular Cell Biology, Cell Biology Unit, University College London, Gower Street, London, WC1E 6BT, UK
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