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Zifkos K, Bochenek ML, Gogiraju R, Robert S, Pedrosa D, Kiouptsi K, Moiko K, Wagner M, Mahfoud F, Poncelet P, Münzel T, Ruf W, Reinhardt C, Panicot-Dubois L, Dubois C, Schäfer K. Endothelial PTP1B Deletion Promotes VWF Exocytosis and Venous Thromboinflammation. Circ Res 2024; 134:e93-e111. [PMID: 38563147 DOI: 10.1161/circresaha.124.324214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 03/25/2024] [Indexed: 04/04/2024]
Abstract
BACKGROUND Endothelial activation promotes the release of procoagulant extracellular vesicles and inflammatory mediators from specialized storage granules. Endothelial membrane exocytosis is controlled by phosphorylation. We hypothesized that the absence of PTP1B (protein tyrosine phosphatase 1B) in endothelial cells promotes venous thromboinflammation by triggering endothelial membrane fusion and exocytosis. METHODS Mice with inducible endothelial deletion of PTP1B (End.PTP1B-KO) underwent inferior vena cava ligation to induce stenosis and venous thrombosis. Primary endothelial cells from transgenic mice and human umbilical vein endothelial cells were used for mechanistic studies. RESULTS Vascular ultrasound and histology showed significantly larger venous thrombi containing higher numbers of Ly6G (lymphocyte antigen 6 family member G)-positive neutrophils in mice with endothelial PTP1B deletion, and intravital microscopy confirmed the more pronounced neutrophil recruitment following inferior vena cava ligation. RT2 PCR profiler array and immunocytochemistry analysis revealed increased endothelial activation and adhesion molecule expression in primary End.PTP1B-KO endothelial cells, including CD62P (P-selectin) and VWF (von Willebrand factor). Pretreatment with the NF-κB (nuclear factor kappa B) kinase inhibitor BAY11-7082, antibodies neutralizing CD162 (P-selectin glycoprotein ligand-1) or VWF, or arginylglycylaspartic acid integrin-blocking peptides abolished the neutrophil adhesion to End.PTP1B-KO endothelial cells in vitro. Circulating levels of annexin V+ procoagulant endothelial CD62E+ (E-selectin) and neutrophil (Ly6G+) extracellular vesicles were also elevated in End.PTP1B-KO mice after inferior vena cava ligation. Higher plasma MPO (myeloperoxidase) and Cit-H3 (citrullinated histone-3) levels and neutrophil elastase activity indicated neutrophil activation and extracellular trap formation. Infusion of End.PTP1B-KO extracellular vesicles into C57BL/6J wild-type mice most prominently enhanced the recruitment of endogenous neutrophils, and this response was blunted in VWF-deficient mice or by VWF-blocking antibodies. Reduced PTP1B binding and tyrosine dephosphorylation of SNAP23 (synaptosome-associated protein 23) resulting in increased VWF exocytosis and neutrophil adhesion were identified as mechanisms, all of which could be restored by NF-κB kinase inhibition using BAY11-7082. CONCLUSIONS Our findings show that endothelial PTP1B deletion promotes venous thromboinflammation by enhancing SNAP23 phosphorylation, endothelial VWF exocytosis, and neutrophil recruitment.
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Affiliation(s)
- Konstantinos Zifkos
- Center for Thrombosis and Hemostasis (K.Z., M.L.B., D.P., K.K., W.R., C.R.), University Medical Center Mainz, Germany
| | - Magdalena L Bochenek
- Center for Thrombosis and Hemostasis (K.Z., M.L.B., D.P., K.K., W.R., C.R.), University Medical Center Mainz, Germany
- Department of Cardiology, Cardiology I (M.L.B., R.G., K.M., T.M., K.S.), University Medical Center Mainz, Germany
| | - Rajinikanth Gogiraju
- Department of Cardiology, Cardiology I (M.L.B., R.G., K.M., T.M., K.S.), University Medical Center Mainz, Germany
| | - Stéphane Robert
- Aix Marseille University, National Institute of Health and Medical Research (INSERM) 1263, National Research Institute for Agriculture, Food and Environment (INRAE), Cardiovascular and Nutrition Research Center (C2VN), France (S.R., L.P.-D., C.D.)
| | - Denise Pedrosa
- Center for Thrombosis and Hemostasis (K.Z., M.L.B., D.P., K.K., W.R., C.R.), University Medical Center Mainz, Germany
| | - Klytaimnistra Kiouptsi
- Center for Thrombosis and Hemostasis (K.Z., M.L.B., D.P., K.K., W.R., C.R.), University Medical Center Mainz, Germany
| | - Kateryna Moiko
- Department of Cardiology, Cardiology I (M.L.B., R.G., K.M., T.M., K.S.), University Medical Center Mainz, Germany
| | - Mathias Wagner
- Institute of Pathology, Saarland University Medical Center and Saarland University Faculty of Medicine, Homburg, Germany (M.W.)
| | - Felix Mahfoud
- Department of Internal Medicine III, Cardiology, Angiology and Internal Intensive Care Medicine, Saarland University Hospital and Saarland University, Homburg, Germany (F.M.)
| | | | - Thomas Münzel
- Department of Cardiology, Cardiology I (M.L.B., R.G., K.M., T.M., K.S.), University Medical Center Mainz, Germany
| | - Wolfram Ruf
- Center for Thrombosis and Hemostasis (K.Z., M.L.B., D.P., K.K., W.R., C.R.), University Medical Center Mainz, Germany
| | - Christoph Reinhardt
- Center for Thrombosis and Hemostasis (K.Z., M.L.B., D.P., K.K., W.R., C.R.), University Medical Center Mainz, Germany
| | - Laurence Panicot-Dubois
- Aix Marseille University, National Institute of Health and Medical Research (INSERM) 1263, National Research Institute for Agriculture, Food and Environment (INRAE), Cardiovascular and Nutrition Research Center (C2VN), France (S.R., L.P.-D., C.D.)
| | - Christophe Dubois
- Aix Marseille University, National Institute of Health and Medical Research (INSERM) 1263, National Research Institute for Agriculture, Food and Environment (INRAE), Cardiovascular and Nutrition Research Center (C2VN), France (S.R., L.P.-D., C.D.)
| | - Katrin Schäfer
- Department of Cardiology, Cardiology I (M.L.B., R.G., K.M., T.M., K.S.), University Medical Center Mainz, Germany
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Laurie K, Holcomb D, Kames J, Komar AA, DiCuccio M, Ibla JC, Kimchi-Sarfaty C. In Silico Evaluation of Cyclophilin Inhibitors as Potential Treatment for SARS-CoV-2. Open Forum Infect Dis 2021; 8:ofab189. [PMID: 34109257 PMCID: PMC8083350 DOI: 10.1093/ofid/ofab189] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 04/10/2021] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND The advent of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) provoked researchers to propose multiple antiviral strategies to improve patients' outcomes. Studies provide evidence that cyclosporine A (CsA) decreases SARS-CoV-2 replication in vitro and decreases mortality rates of coronavirus disease 2019 (COVID-19) patients. CsA binds cyclophilins, which isomerize prolines, affecting viral protein activity. METHODS We investigated the proline composition from various coronavirus proteomes to identify proteins that may critically rely on cyclophilin's peptidyl-proline isomerase activity and found that the nucleocapsid (N) protein significantly depends on cyclophilin A (CyPA). We modeled CyPA and N protein interactions to demonstrate the N protein as a potential indirect therapeutic target of CsA, which we propose may impede coronavirus replication by obstructing nucleocapsid folding. RESULTS Finally, we analyzed the literature and protein-protein interactions, finding evidence that, by inhibiting CyPA, CsA may impact coagulation proteins and hemostasis. CONCLUSIONS Despite CsA's promising antiviral characteristics, the interactions between cyclophilins and coagulation factors emphasize risk stratification for COVID patients with thrombosis dispositions.
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Affiliation(s)
- Kyle Laurie
- Center for Biologics Evaluation and Research, Office of Tissues and Advanced Therapies, Division of Plasma Protein Therapeutics, Food and Drug Administration, Silver Spring, Maryland, USA
| | - David Holcomb
- Center for Biologics Evaluation and Research, Office of Tissues and Advanced Therapies, Division of Plasma Protein Therapeutics, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Jacob Kames
- Center for Biologics Evaluation and Research, Office of Tissues and Advanced Therapies, Division of Plasma Protein Therapeutics, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Anton A Komar
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological and Environmental Sciences, Cleveland State University, Cleveland, Ohio, USA
| | - Michael DiCuccio
- National Center of Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - Juan C Ibla
- Division of Cardiac Anesthesia, Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Chava Kimchi-Sarfaty
- Center for Biologics Evaluation and Research, Office of Tissues and Advanced Therapies, Division of Plasma Protein Therapeutics, Food and Drug Administration, Silver Spring, Maryland, USA
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3
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Song SY, Wang ZA, Ding YC, Ji XM, Meng R. Cyclosporine-A-Induced Intracranial Thrombotic Complications: Systematic Review and Cases Report. Front Neurol 2021; 11:563037. [PMID: 33643175 PMCID: PMC7906016 DOI: 10.3389/fneur.2020.563037] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 12/23/2020] [Indexed: 12/04/2022] Open
Abstract
This study reported two cases of intracranial thrombotic events of aplastic anemia (AA) under therapy with cyclosporine-A (CsA) and reviewed both drug-induced cerebral venous thrombosis (CVT) and CsA-related thrombotic events systematically. We searched PubMed Central (PMC) and EMBASE up to Sep 2019 for publications on drug-induced CVT and Cs-A-induced thrombotic events. Medical subject headings and Emtree headings were used with the following keywords: "cyclosporine-A" and "cerebral venous thrombosis OR cerebral vein thrombosis" and "stroke OR Brain Ischemia OR Brain Infarction OR cerebral infarction OR intracerebral hemorrhage OR intracranial hemorrhage." We found that CsA might be a significant risk factor in inducing not only CVT but also cerebral arterial thrombosis in patients with AA.
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Affiliation(s)
- Si-ying Song
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
- Advanced Center of Stroke, Beijing Institute for Brain Disorders, Beijing, China
- Department of China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Zhong-ao Wang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
- Advanced Center of Stroke, Beijing Institute for Brain Disorders, Beijing, China
- Department of China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Yu-chuan Ding
- Department of China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China
- Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI, United States
| | - Xun-ming Ji
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
- Advanced Center of Stroke, Beijing Institute for Brain Disorders, Beijing, China
- Department of China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Ran Meng
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
- Advanced Center of Stroke, Beijing Institute for Brain Disorders, Beijing, China
- Department of China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China
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Ferraro F, Patella F, Costa JR, Ketteler R, Kriston‐Vizi J, Cutler DF. Modulation of endothelial organelle size as an antithrombotic strategy. J Thromb Haemost 2020; 18:3296-3308. [PMID: 32881285 PMCID: PMC8436738 DOI: 10.1111/jth.15084] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 07/31/2020] [Accepted: 08/24/2020] [Indexed: 12/15/2022]
Abstract
BACKGROUND It is long established that von Willebrand factor (VWF) is central to hemostasis and thrombosis. Endothelial VWF is stored in cell-specific secretory granules, Weibel-Palade bodies (WPBs), organelles generated in a wide range of lengths (0.5-5.0 µm). WPB size responds to physiological cues and pharmacological treatment, and VWF secretion from shortened WPBs dramatically reduces platelet and plasma VWF adhesion to an endothelial surface. OBJECTIVE We hypothesized that WPB-shortening represented a novel target for antithrombotic therapy. Our objective was to determine whether compounds exhibiting this activity do exist. METHODS Using a microscopy approach coupled to automated image analysis, we measured the size of WPB bodies in primary human endothelial cells treated with licensed compounds for 24 hours. RESULTS AND CONCLUSIONS A novel approach to identification of antithrombotic compounds generated a significant number of candidates with the ability to shorten WPBs. In vitro assays of two selected compounds confirm that they inhibit the pro-hemostatic activity of secreted VWF. This set of compounds acting at a very early stage of the hemostatic process could well prove to be a useful adjunct to current antithrombotic therapeutics. Further, in the current SARS-CoV-2 pandemic, with a considerable fraction of critically ill COVID-19 patients affected by hypercoagulability, these WPB size-reducing drugs might also provide welcome therapeutic leads for frontline clinicians and researchers.
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Affiliation(s)
- Francesco Ferraro
- Endothelial Cell Biology Group, MRC Laboratory for Molecular Cell BiologyUniversity College LondonLondonUK
- Present address:
Department of Biology and Evolution of Marine Organisms (BEOM)Stazione Zoologica Anton DohrnVilla ComunaleNaplesItaly
| | - Francesca Patella
- Endothelial Cell Biology Group, MRC Laboratory for Molecular Cell BiologyUniversity College LondonLondonUK
| | - Joana R. Costa
- Cell Signalling and Autophagy GroupMRC Laboratory for Molecular Cell BiologyUniversity College LondonLondonUK
- Present address:
Leukaemia Biology Research GroupDepartment of Haematology, Cancer InstituteUniversity College LondonLondonUK
| | - Robin Ketteler
- Cell Signalling and Autophagy GroupMRC Laboratory for Molecular Cell BiologyUniversity College LondonLondonUK
| | - Janos Kriston‐Vizi
- Bioinformatics Image Core (BIONIC)MRC Laboratory for Molecular Cell BiologyUniversity College LondonLondonUK
| | - Daniel F. Cutler
- Endothelial Cell Biology Group, MRC Laboratory for Molecular Cell BiologyUniversity College LondonLondonUK
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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: 77] [Impact Index Per Article: 15.4] [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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6
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Francis CE, Bai Y. Differential expression of cyclosporine A-Induced calcineurin isoform-specific matrix metalloproteinase 9 (MMP-9) in renal fibroblasts. Biochem Biophys Res Commun 2018; 503:2549-2554. [PMID: 30007437 DOI: 10.1016/j.bbrc.2018.07.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 07/04/2018] [Indexed: 01/19/2023]
Abstract
Long-term treatment with the potent immunosuppressive drug cyclosporine A (CsA) results in chronic nephrotoxicity. Its immunosuppressive properties are due to the inhibition of the calcium- and calmodulin-dependent phosphatase protein calcineurin A (CnA) which has three catalytic isoforms. Of those, the CnAα and β isoforms are ubiquitously expressed, particularly in the kidney. Additionally, chronic nephrotoxicity has been associated with an imbalance of extracellular matrix (ECM) synthesis and degradation resulting in an accumulation of ECM molecules. This study evaluates whether the expressions of matrix metalloproteinases (MMP-2 and MMP-9) induced by CsA are calcineurin isoform specific. Wild-type (WT), CnAα knockout (CnAα-/-) and CnAβ knockout (CnAβ-/-) kidney fibroblast cell lines (an in vitro innovative tool that was previously created in our lab) were treated with CsA at 10 ng/ml for 48 h. ELISA analysis demonstrated that the CsA-induced secretion profile of MMP-9 was highest in CnAα-/- cells and lowest in CnAβ-/- cells vs. WT cells. In contrast, CsA did not induce an increase in MMP-2 protein levels in WT, CnAα-/- nor CnAβ-/- renal fibroblasts. These results indicate that MMP-9 secretion is CnA-isoform specific, i.e. the CnAβ isoform contributes to the CsA-induced upregulation of MMP-9 while the CnAα does not. As such, understanding the role of calcineurin A isoforms in the regulation of the homeostasis of ECM degradation in the kidney after long-term CsA treatment needs to be further investigated.
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Affiliation(s)
- Cynthia E Francis
- Department of Pharmaceutical Science, School of Pharmacy, Philadelphia College of Osteopathic Medicine, Suwanee, GA, USA.
| | - Yun Bai
- Department of Pharmaceutical Science, School of Pharmacy, Philadelphia College of Osteopathic Medicine, Suwanee, GA, USA.
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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: 70] [Impact Index Per Article: 10.0] [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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A combined approach to early detect in vitro drug-induced hemostatic changes in preclinical safety. ACTA ACUST UNITED AC 2017; 69:275-283. [DOI: 10.1016/j.etp.2017.01.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 01/12/2017] [Accepted: 01/23/2017] [Indexed: 11/30/2022]
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9
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Da Q, Shaw T, Pradhan S, Roche PA, Cruz MA, Vijayan KV. Disruption of protein complexes containing protein phosphatase 2B and Munc18c reduces the secretion of von Willebrand factor from endothelial cells. J Thromb Haemost 2017; 15:1032-1039. [PMID: 28294518 PMCID: PMC5413388 DOI: 10.1111/jth.13671] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Indexed: 12/01/2022]
Abstract
Essentials Endothelial secretion of von Willebrand factor (VWF) promotes inflammation and thrombosis. We studied the role of protein phosphatase 2B (PP2B) and Munc18c protein complex in VWF secretion. Disruption of PP2B-Munc18c complex in endothelial cells reduced agonist-induced VWF secretion. PP2B-Munc18c complex represents a potential target for thrombotic and inflammatory conditions. SUMMARY Background Aberrant secretion of von Willebrand factor (VWF) from endothelial cells contributes to inflammation and vascular thrombosis. Agonist-induced VWF secretion is facilitated by protein kinase and phosphatase-mediated signaling. Although the catalytic subunit of protein phosphatase 2B (PP2B-Aα) is targeted to the secretory machinery via an interaction with the vesicle trafficking protein Munc18c in endothelial cells, the functional relevance of this phosphatase complex is unclear. Objective To assess the contribution of the PP2B-Aα-Munc18c complex to endothelial VWF secretion. Results Here, we show that amino acids 120-130 of PP2B-Aα are important to support an interaction with Munc18c. A synthetic myristylated cell-permeable peptide, which is derived from amino acids 121-130 of PP2B-Aα, disrupted endogenous PP2B-Aα-Munc18c complexes in human umbilical vein endothelial cells, and decreased low-dose histamine-stimulated and thrombin-stimulated VWF secretion. Conclusion These studies indicate that PP2B-Aα-Munc18c complex supports agonist-induced VWF secretion, and suggest the potential of targeting this phosphatase complex in thrombotic and inflammatory conditions.
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Affiliation(s)
- Qi Da
- Department of Medicine, Michael E. DeBakey Veterans Affairs Medical Center (MEDVAMC), Houston, TX 77030, U.S.A
- Baylor College of Medicine and Center for Translational Research on Inflammatory Diseases (CTRID), Michael E. DeBakey Veterans Affairs Medical Center (MEDVAMC), Houston, TX 77030, U.S.A
| | - Tanner Shaw
- Department of Medicine, Michael E. DeBakey Veterans Affairs Medical Center (MEDVAMC), Houston, TX 77030, U.S.A
- Baylor College of Medicine and Center for Translational Research on Inflammatory Diseases (CTRID), Michael E. DeBakey Veterans Affairs Medical Center (MEDVAMC), Houston, TX 77030, U.S.A
| | - Subhashree Pradhan
- Department of Medicine, Michael E. DeBakey Veterans Affairs Medical Center (MEDVAMC), Houston, TX 77030, U.S.A
- Baylor College of Medicine and Center for Translational Research on Inflammatory Diseases (CTRID), Michael E. DeBakey Veterans Affairs Medical Center (MEDVAMC), Houston, TX 77030, U.S.A
| | - Paul A. Roche
- National Cancer Institute, Bethesda, MD 20892, U.S.A
| | - Miguel A. Cruz
- Department of Medicine, Michael E. DeBakey Veterans Affairs Medical Center (MEDVAMC), Houston, TX 77030, U.S.A
- Baylor College of Medicine and Center for Translational Research on Inflammatory Diseases (CTRID), Michael E. DeBakey Veterans Affairs Medical Center (MEDVAMC), Houston, TX 77030, U.S.A
- Department of Pediatrics, Michael E. DeBakey Veterans Affairs Medical Center (MEDVAMC), Houston, TX 77030, U.S.A
- Department of Molecular Physiology and Biophysics, Michael E. DeBakey Veterans Affairs Medical Center (MEDVAMC), Houston, TX 77030, U.S.A
| | - K. Vinod Vijayan
- Department of Medicine, Michael E. DeBakey Veterans Affairs Medical Center (MEDVAMC), Houston, TX 77030, U.S.A
- Baylor College of Medicine and Center for Translational Research on Inflammatory Diseases (CTRID), Michael E. DeBakey Veterans Affairs Medical Center (MEDVAMC), Houston, TX 77030, U.S.A
- Department of Pediatrics, Michael E. DeBakey Veterans Affairs Medical Center (MEDVAMC), Houston, TX 77030, U.S.A
- Department of Molecular Physiology and Biophysics, Michael E. DeBakey Veterans Affairs Medical Center (MEDVAMC), Houston, TX 77030, U.S.A
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Khatlani T, Pradhan S, Da Q, Gushiken FC, Bergeron AL, Langlois KW, Molkentin JD, Rumbaut RE, Vijayan KV. The β isoform of the catalytic subunit of protein phosphatase 2B restrains platelet function by suppressing outside-in αII b β3 integrin signaling. J Thromb Haemost 2014; 12:2089-101. [PMID: 25330904 PMCID: PMC4268338 DOI: 10.1111/jth.12761] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 10/07/2014] [Indexed: 01/25/2023]
Abstract
BACKGROUND Calcium-dependent signaling mechanisms play a critical role in platelet activation. Unlike calcium-activated protease and kinase, the contribution of calcium-activated protein serine/threonine phosphatase in platelet activation is poorly understood. OBJECTIVE To assess the role of catalytic subunit of protein phosphatase 2B (PP2B) or calcineurin in platelet function. RESULTS Here, we showed that an increase in PP2B activity was associated with agonist-induced activation of human and murine platelets. Pharmacological inhibitors of the catalytic subunit of protein phosphatase 2B (PP2B-A) such as cyclosporine A or tacrolimus (FK506) potentiated aggregation of human platelets. Murine platelets lacking the β isoform of PP2B-A (PP2B-Aβ(-/-) ) displayed increased aggregation with low doses of agonist concentrations. Loss of PP2B-Aβ did not affect agonist-induced integrin αII b β3 inside-out signaling, but increased basal Src activation and outside-in αII b β3 signaling to p38 mitogen-activated protein kinase (MAPK), with a concomitant enhancement in platelet spreading on immobilized fibrinogen and greater fibrin clot retraction. Fibrinogen-induced increased p38 activation in PP2B-Aβ(-/-) platelets were blocked by Src inhibitor. Both PP2B-Aβ(-/-) platelets and PP2B-Aβ-depleted human embryonal kidney 293 αII b β3 cells displayed increased adhesion to immobilized fibrinogen. Filamin A, an actin crosslinking phosphoprotein that is known to associate with β3 , was dephosphorylated on Ser(2152) in fibrinogen-adhered wild-type but not in PP2B-Aβ(-/-) platelets. In a FeCl3 injury thrombosis model, PP2B-Aβ(-/-) mice showed decreased time to occlusion in the carotid artery. CONCLUSION These observations indicate that PP2B-Aβ by suppressing outside-in αII b β3 integrin signaling limits platelet response to vascular injury.
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Affiliation(s)
- Tanvir Khatlani
- Department of Medicine, Michael E. DeBakey VA Medical Center, Houston, TX 77030, USA
| | - Subhashree Pradhan
- Department of Medicine, Michael E. DeBakey VA Medical Center, Houston, TX 77030, USA
| | - Qi Da
- Department of Medicine, Michael E. DeBakey VA Medical Center, Houston, TX 77030, USA
| | - Francisca C. Gushiken
- Department of Medicine, Michael E. DeBakey VA Medical Center, Houston, TX 77030, USA
| | - Angela L. Bergeron
- Department of Medicine, Michael E. DeBakey VA Medical Center, Houston, TX 77030, USA
| | - Kimberly W. Langlois
- Department of Pediatrics, Molecular Physiology, Michael E. DeBakey VA Medical Center, Houston, TX 77030, USA
| | - Jeffery D. Molkentin
- Molecular Cardiovascular Biology Program, Howard Hughes Medical Institute, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Rolando E. Rumbaut
- Department of Medicine, Michael E. DeBakey VA Medical Center, Houston, TX 77030, USA
- Department of Pediatrics, Molecular Physiology, Michael E. DeBakey VA Medical Center, Houston, TX 77030, USA
- Center for Translational Research on Inflammatory Diseases (CTRID), Michael E. DeBakey VA Medical Center, Houston, TX 77030, USA
| | - K. Vinod Vijayan
- Department of Medicine, Michael E. DeBakey VA Medical Center, Houston, TX 77030, USA
- Department of Pediatrics, Molecular Physiology, Michael E. DeBakey VA Medical Center, Houston, TX 77030, USA
- Center for Translational Research on Inflammatory Diseases (CTRID), Michael E. DeBakey VA Medical Center, Houston, TX 77030, USA
- Department of Biophysics, Baylor College of Medicine, Michael E. DeBakey VA Medical Center, Houston, TX 77030, USA
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11
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Vasauskas AA, Chen H, Wu S, Cioffi DL. The serine-threonine phosphatase calcineurin is a regulator of endothelial store-operated calcium entry. Pulm Circ 2014; 4:116-27. [PMID: 25006427 DOI: 10.1086/675641] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 01/15/2014] [Indexed: 01/25/2023] Open
Abstract
Disruption of the endothelium leads to increased permeability, allowing extravasation of macromolecules and other solutes from blood vessels. Calcium entry through a calcium-selective, store-operated calcium (SOC) channel, I soc, contributes to barrier disruption. An understanding of the mechanisms surrounding the regulation of I soc is far from complete. We show that the calcium/calmodulin-activated phosphatase calcineurin (CN) plays a role in regulation of SOC entry, possibly through the dephosphorylation of stromal interaction molecule 1 (STIM1). Phosphorylation has been implicated as a regulatory mechanism of activity for a number of canonical transient receptor potential (TRPC) and SOC channels, including I soc. Our results show that STIM1 phosphorylation increases in pulmonary artery endothelial cells (PAECs) upon activation of SOC entry. However, the phosphatases involved in STIM1 dephosphorylation are unknown. We found that a CN inhibitor (calcineurin inhibitory peptide [CIP]) increases the phosphorylation pattern of STIM1. Using a fura 2-acetoxymethyl ester approach to measure cytosolic calcium in PAECs, we found that CIP decreases SOC entry following thapsigargin treatment in PAECs. Luciferase assays indicate that thapsigargin induces activation of CN activity and confirm inhibition of CN activity by CIP in PAECs. Also, I soc is significantly attenuated in whole-cell patch-clamp studies of PAECs treated with CIP. Finally, PAECs pretreated with CIP exhibit decreased interendothelial cell gap formation in response to thapsigargin-induced SOC entry, as compared to control cells. Taken together, our data show that CN contributes to the phosphorylation status of STIM1, which is important in regulation of endothelial SOC entry and I soc activity.
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Affiliation(s)
- Audrey A Vasauskas
- Departments of Biochemistry and Molecular Biology and Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA
| | - Hairu Chen
- Department of Anesthesiology and Perioperative Medicine, Georgia Regents University, Augusta, Georgia, USA
| | - Songwei Wu
- Department of Anesthesiology and Perioperative Medicine, Georgia Regents University, Augusta, Georgia, USA
| | - Donna L Cioffi
- Departments of Biochemistry and Molecular Biology and Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA
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12
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Nwaba A, MacQuillan G, Adams LA, Garas G, Delriviere L, Augustson B, DeBoer B, Moody H, Jeffrey GP. Tacrolimus-induced thrombotic microangiopathy in orthotopic liver transplant patients: case series of four patients. Intern Med J 2013; 43:328-33. [PMID: 23441660 DOI: 10.1111/imj.12048] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Accepted: 08/26/2012] [Indexed: 12/23/2022]
Abstract
Thrombotic microangiopathy (TMA) is a potentially fatal complication in solid organ and bone marrow transplant patients, with reported incidence of 0.5-3% and mortality of about 75%. To emphasise the importance of early diagnosis and prompt commencement of therapy results in improved clinical outcomes. A retrospective study of all patients who underwent orthotopic liver transplantation (OLTX) at the Western Australian Liver Transplantation Service from May 1994 to December 2010 was conducted to identify patients who developed tacrolimus-induced TMA. We identified four patients with tacrolimus-induced TMA post-OLTX, derived from a cohort of 104 patients treated with tacrolimus in our institution. The mean age at diagnosis was 40 years, and the mean time of onset was 63 ± 7.5 weeks after OLTX. The indications for OLTX in the four patients were fulminant hepatic failure in three (Wilson disease, paracetamol overdose and post-partum thrombotic thrombocytopenic purpura) and hepatitis C virus-related cirrhosis. All patients had tacrolimus post-OLTX. At diagnosis, tacrolimus was discontinued in all patients, and three of the four patients underwent plasma exchange and all patients improved clinically. Mean duration of follow up was 15 ± 7.5 months. There was no mortality 6 months post-TMA. Early diagnosis with immediate discontinuation or conversion of calcineurin inhibitors and plasma exchange should be offered to OLTX patients with TMA as it results in good outcomes.
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Affiliation(s)
- A Nwaba
- West Australian Liver Transplant Service, University of Western Australia, Perth, Australia.
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13
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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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14
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Casonato A, Pontara E, Battiston M, Morpurgo M, Cattini MG, Casarin E, Saga G, Daidone V, De Marco L. C2362F mutation gives rise to an ADAMTS13-resistant von Willebrand factor. Thromb Haemost 2013; 109:999-1006. [PMID: 23446343 DOI: 10.1160/th12-11-0808] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Accepted: 02/05/2013] [Indexed: 11/05/2022]
Abstract
von Willebrand factor (VWF) multimers result from proteolysis by the metalloprotease ADAMTS13. Since C2362F-VWF features abnormally large multimers with their triplet oligomer structure replaced by a diffuse smear, we explored the susceptibility of C2362F-VWF to ADAMTS13. VWF-enriched blood samples, obtained by cryoethanol precipitation of plasma from a patient with von Willebrand disease (VWD) homozygous for the C2362F mutation and a normal subject, were submitted to cleavage by recombinant ADAMTS13 under static conditions in the presence of urea. C2362F-VWF proved completely ADAMTS13-resistant in vitro. At any concentration of recombinant ADAMTS13 (from 0.1 µM to 1 µM), there was no evidence of the abnormally large VWF multimers of C2362F-VWF disappearing, nor any increased representation of triplet multimer bands, unlike the situation seen in normal VWF. This is due partly to a defective ADAMTS13 binding to C2362F-VWF under static conditions, as seen in both the patient's and recombinant mutated VWF proteins. These findings were associated with a significantly shorter than normal survival of C2362F-VWF after DDAVP, demonstrating that proteolysis and VWF survival may be independent phenomena. Our findings clearly demonstrate that the loss of cysteine 2362 makes VWF resistant to proteolysis by ADAMTS13, at least partly due to an impaired ADAMTS13 binding to VWF. This suggests that the B2 domain of VWF is involved in modulating ADAMTS13 binding to VWF and the consequent proteolytic process. The C2362F-VWF mutation also enables a new abnormality to be identified in the VWF-ADAMTS13 relationship, i.e. an ADAMTS13-resistant VWF.
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Affiliation(s)
- Alessandra Casonato
- Dept. of Cardiologic, Thoracic and Vascular Sciences, Via Ospedale Civile 105, Padua, Italy.
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15
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Kessler CS, Khan BA, Lai-Miller K. Thrombotic Thrombocytopenic Purpura: A Hematological Emergency. J Emerg Med 2012; 43:538-44. [DOI: 10.1016/j.jemermed.2012.01.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 09/23/2011] [Accepted: 01/16/2012] [Indexed: 12/11/2022]
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16
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Czubkowski P, Pawłowska J, Jankowska I, Teisseyre M, Kamińska D, Markiewicz M, Ryżko J. Successful sirolimus rescue in tacrolimus-induced thrombotic microangiopathy after living-related liver transplantation. Pediatr Transplant 2012; 16:E261-4. [PMID: 22066835 DOI: 10.1111/j.1399-3046.2011.01601.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
TMA is a rare complication of tacrolimus. Disruption of endothelial cells, platelet aggregation, and intravascular mechanical fragmentation of red cells are core mechanisms of injury; however, exact pathways of toxicity are not clear. The clinical presentation may vary but TMA is a potentially life-threatening condition usually demanding aggressive treatment. We present the case of TMA in a child after living-related liver transplantation (LRLTx) on tacrolimus-based immunosuppressive regiment successfully converted to sirolimus.
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Affiliation(s)
- Piotr Czubkowski
- Department of Gastroenterology, The Children's Memorial Health Institute, Warsaw, Poland.
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17
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Obeidat M, Obeidat M, Ballermann BJ. Glomerular endothelium: A porous sieve and formidable barrier. Exp Cell Res 2012; 318:964-72. [DOI: 10.1016/j.yexcr.2012.02.032] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2011] [Accepted: 02/24/2012] [Indexed: 12/20/2022]
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18
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Abstract
Weibel-Palade bodies (WPBs) are elongated secretory organelles specific to endothelial cells that contain von Willebrand factor (VWF) and a variety of other proteins that contribute to inflammation, angiogenesis, and tissue repair. The remarkable architecture of WPBs is because of the unique properties of their major constituent VWF. VWF is stored inside WPBs as tubules, but on its release, forms strikingly long strings that arrest bleeding by recruiting blood platelets to sites of vascular injury. In recent years considerable progress has been made regarding the molecular events that underlie the packaging of VWF multimers into tubules and the processes leading to the formation of elongated WPBs. Mechanisms directing the conversion of tightly packaged VWF tubules into VWF strings on the surface of endothelial cells are starting to be unraveled. Several modes of exocytosis have now been described for WPBs, emphasizing the plasticity of these organelles. WPB exocytosis plays a role in the pathophysiology and treatment of von Willebrand disease and may have impact on common hematologic and cardiovascular disorders. This review summarizes the major advances made on the biogenesis and exocytosis of WPBs and places these recent discoveries in the context of von Willebrand disease.
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19
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Pulido IR, Jahn R, Gerke V. VAMP3 is associated with endothelial weibel-palade bodies and participates in their Ca(2+)-dependent exocytosis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2010; 1813:1038-44. [PMID: 21094665 DOI: 10.1016/j.bbamcr.2010.11.007] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2010] [Revised: 10/25/2010] [Accepted: 11/06/2010] [Indexed: 11/27/2022]
Abstract
Weibel-Palade bodies (WPBs) are secretory organelles of endothelial cells that store the thrombogenic glycoprotein von Willebrand factor (vWF). Endothelial activation, e.g. by histamine and thrombin, triggers the Ca(2+)-dependent exocytosis of WPB that releases vWF into the vasculature and thereby initiates platelet capture and thrombus formation. Towards understanding the molecular mechanisms underlying this regulated WPB exocytosis, we here identify components of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) machinery associated with WPB. We show that vesicle-associated membrane protein (VAMP) 3 and VAMP8 are present on WPB and that VAMP3, but not VAMP8 forms a stable complex with syntaxin 4 and SNAP23, two plasma membrane-associated SNAREs in endothelial cells. By introducing mutant SNARE proteins into permeabilized endothelial cells we also show that soluble VAMP3 but not VAMP8 mutants comprising the cytoplasmic domain interfere with efficient vWF secretion. This indicates that endothelial cells specifically select VAMP 3 over VAMP8 to cooperate with syntaxin 4 and SNAP23 in the Ca(2+)-triggered fusion of WPB with the plasma membrane. This article is part of a Special Issue entitled: 11th European Symposium on Calcium.
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Affiliation(s)
- Inés Rojo Pulido
- Institute of Medical Biochemistry, Centre for Molecular Biology of Inflammation, University of Münster, D-48149 Münster, Germany
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20
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Moake J. Thrombotic microangiopathies: multimers, metalloprotease, and beyond. Clin Transl Sci 2010; 2:366-73. [PMID: 20443921 DOI: 10.1111/j.1752-8062.2009.00142.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The pathophysiology of various types of thrombotic microangiopathies is coming progressively into focus. Therapeutic advances are likely to follow at a quickening pace. This discussion focuses on thrombotic thrombocytopenic purpura (TTP), the hemolytic-uremic syndrome (HUS), thrombotic microangiopathies associated with transplantation-immunosuppression or anti-angiogenesis therapy, and the preeclampsia/hemolysis-elevated liver enzymes and low platelets syndrome (HELLP).
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21
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Jewell JL, Oh E, Thurmond DC. Exocytosis mechanisms underlying insulin release and glucose uptake: conserved roles for Munc18c and syntaxin 4. Am J Physiol Regul Integr Comp Physiol 2010; 298:R517-31. [PMID: 20053958 DOI: 10.1152/ajpregu.00597.2009] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Type 2 diabetes has been coined "a two-hit disease," as it involves specific defects of glucose-stimulated insulin secretion from the pancreatic beta cells in addition to defects in peripheral tissue insulin action required for glucose uptake. Both of these processes, insulin secretion and glucose uptake, are mediated by SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) protein core complexes composed of syntaxin, SNAP-23/25, and VAMP proteins. The SNARE core complex is regulated by the Sec1/Munc18 (SM) family of proteins, which selectively bind to their cognate syntaxin isoforms with high affinity. The process of insulin secretion uses multiple Munc18-syntaxin isoform pairs, whereas insulin action in the peripheral tissues appears to use only the Munc18c-syntaxin 4 pair. Importantly, recent reports have linked obesity and Type 2 diabetes in humans with changes in protein levels and single nucleotide polymorphisms (SNPs) of Munc18 and syntaxin isoforms relevant to these exocytotic processes, although the molecular mechanisms underlying the observed phenotypes remain incomplete (5, 104, 144). Given the conservation of these proteins in two seemingly disparate processes and the need to design and implement novel and more effective clinical interventions, it will be vitally important to delineate the mechanisms governing these conserved SNARE-mediated exocytosis events. Thus, we provide here an up-to-date historical review of advancements in defining the roles and molecular mechanisms of Munc18-syntaxin complexes in the pathophysiology of Type 2 diabetes.
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Affiliation(s)
- Jenna L Jewell
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
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22
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Moake J. Thrombotic thrombocytopenia purpura (TTP) and other thrombotic microangiopathies. Best Pract Res Clin Haematol 2009; 22:567-76. [DOI: 10.1016/j.beha.2009.07.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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23
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Zhang Z, Li W. [Formation and function of Weibel-Palade bodies]. YI CHUAN = HEREDITAS 2009; 31:882-8. [PMID: 19819840 DOI: 10.3724/sp.j.1005.2009.00882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Weibel-Palade bodies (WPB) are specialized cigar-shaped secretory organelles in endothelial cells, which contain a variety of biologically active molecules. These contents can be released rapidly by stimulation and involved in hemostasis, inflammation and angiogenesis. The main component of WPB is von Willebrand factor (vWF), whose expression and tubulation are necessary for the formation of the unique rod-like WPBs. Different molecules such as vWF, P-selectin, CD63, Rab27A and Rab3D are recruited into WPB mediated by the AP-1, AP-3 or other transport machinery. The underlying mechanism of the formation of WPB remains further investigation, which will gain insights into its function. The molecular mechanism of WPB formation and its function were discussed in this review.
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Affiliation(s)
- Zhe Zhang
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
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