1
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Higashio H, Yokoyama T, Saino T. A convenient fluorimetry-based degranulation assay using RBL-2H3 cells. Biosci Biotechnol Biochem 2024; 88:181-188. [PMID: 37968134 DOI: 10.1093/bbb/zbad160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 11/12/2023] [Indexed: 11/17/2023]
Abstract
Type I hypersensitivity is triggered by mast cell degranulation, a stimulus-induced exocytosis of preformed secretory granules (SGs) containing various inflammatory mediators. The degree of degranulation is generally expressed as a percentage of secretory granule markers (such as β-hexosaminidase and histamine) released into the external solution, and considerable time and labor are required for the quantification of markers in both the supernatants and cell lysates. In this study, we developed a simple fluorimetry-based degranulation assay using rat basophilic leukemia (RBL-2H3) mast cells. During degranulation, the styryl dye FM1-43 in the external solution fluorescently labeled the newly exocytosed SGs, whose increase in intensity was successively measured using a fluorescence microplate reader. In addition to the rate of β-hexosaminidase secretion, the cellular FM1-43 intensity successfully represented the degree and kinetics of degranulation under various conditions, suggesting that this method facilitates multi-sample and/or multi-time-point analyses required for screening substances regulating mast cell degranulation.
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Affiliation(s)
- Hironori Higashio
- Department of Chemistry, Center for Liberal Arts and Sciences, Iwate Medical University, Yahaba, Iwate, Japan
| | - Takuya Yokoyama
- Division of Cell Biology, Department of Anatomy, Iwate Medical University, Yahaba, Iwate, Japan
| | - Tomoyuki Saino
- Division of Cell Biology, Department of Anatomy, Iwate Medical University, Yahaba, Iwate, Japan
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2
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Vastert SJ, Canny SP, Canna SW, Schneider R, Mellins ED. Cytokine Storm Syndrome Associated with Systemic Juvenile Idiopathic Arthritis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 1448:323-353. [PMID: 39117825 DOI: 10.1007/978-3-031-59815-9_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/10/2024]
Abstract
The cytokine storm syndrome (CSS) associated with systemic juvenile idiopathic arthritis (sJIA) has widely been referred to as macrophage activation syndrome (MAS). In this chapter, we use the term sJIA-associated CSS (sJIA-CSS) when referring to this syndrome and use the term MAS when referencing publications that specifically report on sJIA-associated MAS.
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Affiliation(s)
- Sebastiaan J Vastert
- Department of Paediatric Rheumatology & Immunology and Center for Translational Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Susan P Canny
- Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - Scott W Canna
- Department of Pediatrics and Institute for Immunology, University of Pennsylvania, Philadelphia, PA, USA
| | - Rayfel Schneider
- Department of Paediatrics, University of Toronto and The Hospital for Sick Children, Toronto, ON, Canada
| | - Elizabeth D Mellins
- Divisions of Human Gene Therapy and Allergy, Immunology & Rheumatology, Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA.
- Stanford Program in Immunology, Stanford University School of Medicine, Stanford, CA, USA.
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3
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Alam MR, Rahman MM, Li Z. The link between intracellular calcium signaling and exosomal PD-L1 in cancer progression and immunotherapy. Genes Dis 2024; 11:321-334. [PMID: 37588227 PMCID: PMC10425812 DOI: 10.1016/j.gendis.2023.01.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 01/24/2023] [Accepted: 01/30/2023] [Indexed: 03/29/2023] Open
Abstract
Exosomes are small membrane vesicles containing microRNA, RNA, DNA fragments, and proteins that are transferred from donor cells to recipient cells. Tumor cells release exosomes to reprogram the factors associated with the tumor microenvironment (TME) causing tumor metastasis and immune escape. Emerging evidence revealed that cancer cell-derived exosomes carry immune inhibitory molecule program death ligand 1 (PD-L1) that binds with receptor program death protein 1 (PD-1) and promote tumor progression by escaping immune response. Currently, some FDA-approved monoclonal antibodies are clinically used for cancer treatment by blocking PD-1/PD-L1 interaction. Despite notable treatment outcomes, some patients show poor drug response. Exosomal PD-L1 plays a vital role in lowering the treatment response, showing resistance to PD-1/PD-L1 blockage therapy through recapitulating the effect of cell surface PD-L1. To enhance therapeutic response, inhibition of exosomal PD-L1 is required. Calcium signaling is the central regulator of tumorigenesis and can regulate exosome biogenesis and secretion by modulating Rab GTPase family and membrane fusion factors. Immune checkpoints are also connected with calcium signaling and calcium channel blockers like amlodipine, nifedipine, lercanidipine, diltiazem, and verapamil were also reported to suppress cellular PD-L1 expression. Therefore, to enhance the PD-1/PD-L1 blockage therapy response, the reduction of exosomal PD-L1 secretion from cancer cells is in our therapeutic consideration. In this review, we proposed a therapeutic strategy by targeting calcium signaling to inhibit the expression of PD-L1-containing exosome levels that could reduce the anti-PD-1/PD-L1 therapy resistance and increase the patient's drug response rate.
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Affiliation(s)
- Md Rakibul Alam
- Department of Toxicology and Cancer Biology, College of Medicine, University of Kentucky, Lexington, KY 40506, USA
| | - Md Mizanur Rahman
- Department of Medicine (Nephrology), Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6E2H7, Canada
| | - Zhiguo Li
- Department of Toxicology and Cancer Biology, College of Medicine, University of Kentucky, Lexington, KY 40506, USA
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4
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Han QF, Li WJ, Hu KS, Gao J, Zhai WL, Yang JH, Zhang SJ. Exosome biogenesis: machinery, regulation, and therapeutic implications in cancer. Mol Cancer 2022; 21:207. [PMID: 36320056 PMCID: PMC9623991 DOI: 10.1186/s12943-022-01671-0] [Citation(s) in RCA: 136] [Impact Index Per Article: 68.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 10/13/2022] [Indexed: 12/14/2022] Open
Abstract
Exosomes are well-known key mediators of intercellular communication and contribute to various physiological and pathological processes. Their biogenesis involves four key steps, including cargo sorting, MVB formation and maturation, transport of MVBs, and MVB fusion with the plasma membrane. Each process is modulated through the competition or coordination of multiple mechanisms, whereby diverse repertoires of molecular cargos are sorted into distinct subpopulations of exosomes, resulting in the high heterogeneity of exosomes. Intriguingly, cancer cells exploit various strategies, such as aberrant gene expression, posttranslational modifications, and altered signaling pathways, to regulate the biogenesis, composition, and eventually functions of exosomes to promote cancer progression. Therefore, exosome biogenesis-targeted therapy is being actively explored. In this review, we systematically summarize recent progress in understanding the machinery of exosome biogenesis and how it is regulated in the context of cancer. In particular, we highlight pharmacological targeting of exosome biogenesis as a promising cancer therapeutic strategy.
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Affiliation(s)
- Qing-Fang Han
- grid.412633.10000 0004 1799 0733Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052 Henan China ,grid.412633.10000 0004 1799 0733Henan Research Centre for Organ Transplantation, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052 Henan China
| | - Wen-Jia Li
- grid.412536.70000 0004 1791 7851Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation Medical Research Center, Sun Yat-Sen Memorial Hospital Sun Yat-Sen University, Guangzhou, 510120 China
| | - Kai-Shun Hu
- grid.412536.70000 0004 1791 7851Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation Medical Research Center, Sun Yat-Sen Memorial Hospital Sun Yat-Sen University, Guangzhou, 510120 China
| | - Jie Gao
- grid.412633.10000 0004 1799 0733Henan Research Centre for Organ Transplantation, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052 Henan China ,Henan Diagnosis & Treatment League for Hepatopathy, Zhengzhou, 450052 Henan China
| | - Wen-Long Zhai
- grid.412633.10000 0004 1799 0733Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052 Henan China
| | - Jing-Hua Yang
- grid.412633.10000 0004 1799 0733Clinical Systems Biology Key Laboratories of Henan, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052 Henan China
| | - Shui-Jun Zhang
- grid.412633.10000 0004 1799 0733Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052 Henan China ,grid.412633.10000 0004 1799 0733Henan Research Centre for Organ Transplantation, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052 Henan China ,Henan Diagnosis & Treatment League for Hepatopathy, Zhengzhou, 450052 Henan China ,Henan Engineering & Research Center for Diagnosis and Treatment of Hepatobiliary and Pancreatic Surgical Diseases, Zhengzhou, 450052 Henan China
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5
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The biogenesis and secretion of exosomes and multivesicular bodies (MVBs): Intercellular shuttles and implications in human diseases. Genes Dis 2022. [PMID: 37492712 PMCID: PMC10363595 DOI: 10.1016/j.gendis.2022.03.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Exosomes carry and transmit signaling molecules used for intercellular communication. The generation and secretion of exosomes is a multistep interlocking process that allows simultaneous control of multiple regulatory sites. Protein molecules, mainly RAB GTPases, cytoskeletal proteins and soluble N-ethylmaleimide-sensitive fusion attachment protein receptor (SNARE), are specifically regulated in response to pathological conditions such as altered cellular microenvironment, stimulation by pathogenic factors, or gene mutation. This interferes with the smooth functioning of endocytosis, translocation, degradation, docking and fusion processes, leading to changes in the secretion of exosomes. Large numbers of secreted exosomes are disseminated by the flow of body fluids and absorbed by the recipient cells. By transmitting characteristic functional proteins and genetic information produced under disease conditions, exosomes can change the physiological state of the recipient cells and their microenvironment. The microenvironment, in turn, affects the occurrence and development of disease. Therefore, this review will discuss the mechanism by which exosome secretion is regulated in cells following the formation of mature secretory multivesicular bodies (MVBs). The overall aim is to find ways to eliminate disease-derived exosomes at their source, thereby providing an important new basis for the clinical treatment of disease.
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6
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Ménasché G, Longé C, Bratti M, Blank U. Cytoskeletal Transport, Reorganization, and Fusion Regulation in Mast Cell-Stimulus Secretion Coupling. Front Cell Dev Biol 2021; 9:652077. [PMID: 33796537 PMCID: PMC8007931 DOI: 10.3389/fcell.2021.652077] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 02/03/2021] [Indexed: 01/16/2023] Open
Abstract
Mast cells are well known for their role in allergies and many chronic inflammatory diseases. They release upon stimulation, e.g., via the IgE receptor, numerous bioactive compounds from cytoplasmic secretory granules. The regulation of granule secretion and its interaction with the cytoskeleton and transport mechanisms has only recently begun to be understood. These studies have provided new insight into the interaction between the secretory machinery and cytoskeletal elements in the regulation of the degranulation process. They suggest a tight coupling of these two systems, implying a series of specific signaling effectors and adaptor molecules. Here we review recent knowledge describing the signaling events regulating cytoskeletal reorganization and secretory granule transport machinery in conjunction with the membrane fusion machinery that occur during mast cell degranulation. The new insight into MC biology offers novel strategies to treat human allergic and inflammatory diseases targeting the late steps that affect harmful release from granular stores leaving regulatory cytokine secretion intact.
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Affiliation(s)
- Gaël Ménasché
- Laboratory of Molecular Basis of Altered Immune Homeostasis, Imagine Institute, INSERM UMR 1163, Université de Paris, Paris, France
| | - Cyril Longé
- Laboratory of Molecular Basis of Altered Immune Homeostasis, Imagine Institute, INSERM UMR 1163, Université de Paris, Paris, France
| | - Manuela Bratti
- Centre de Recherche sur l'Inflammation, INSERM UMR 1149, CNRS ERL8252, Faculté de Médecine site Bichat, Université de Paris, Paris, France.,Laboratoire d'Excellence Inflamex, Université de Paris, Paris, France
| | - Ulrich Blank
- Centre de Recherche sur l'Inflammation, INSERM UMR 1149, CNRS ERL8252, Faculté de Médecine site Bichat, Université de Paris, Paris, France.,Laboratoire d'Excellence Inflamex, Université de Paris, Paris, France
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7
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Ayo TE, Adhikari P, Sugita S, Xu H. TNF Production in Activated RBL-2H3 Cells Requires Munc13-4. Inflammation 2021; 43:744-751. [PMID: 31897916 DOI: 10.1007/s10753-019-01161-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Mast cell activation triggers intricate signaling pathways that promote the expression and/or release of a wide range of mediators including tumor necrosis factor (TNF; also known as TNFα). In this study, we investigated the connection between TNF secretion and TNF production, exploiting RBL-2H3 cells (a tumor analog of mucosal mast cells) that are depleted of Munc13-4, a crucial component of the mast cell exocytic machinery. We showed that antigen/IgE elicited robust TNF production in RBL-2H3 cells, but not in Munc13-4 knockout cells. The production defect was corrected when Munc13-4 was reintroduced into the knockout cell line, suggesting that the phenotype was not caused by any secondary effect derived from the knockout approach. Furthermore, pre-incubation of RBL-2H3 cells with R-7050, an antagonist of TNF receptor-dependent signaling, was shown to block TNF production without inhibiting TNF release. These observations provide fresh evidence for a robust feed-back loop to boost TNF production in activated mast cells.
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Affiliation(s)
- Tolulope E Ayo
- Department of Cell and Molecular Biology, School of Biological, Environmental, and Earth Sciences, University of Southern Mississippi, Hattiesburg, MS, 39406, USA
| | - Pratikshya Adhikari
- Department of Cell and Molecular Biology, School of Biological, Environmental, and Earth Sciences, University of Southern Mississippi, Hattiesburg, MS, 39406, USA
| | - Shuzo Sugita
- Division of Fundamental Neurobiology, University Health Network, Toronto, ON, M5T 2S8, Canada.,Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Hao Xu
- Department of Cell and Molecular Biology, School of Biological, Environmental, and Earth Sciences, University of Southern Mississippi, Hattiesburg, MS, 39406, USA.
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8
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Chelombitko MA, Chernyak BV, Fedorov AV, Zinovkin RA, Razin E, Paruchuru LB. The Role Played by Mitochondria in FcεRI-Dependent Mast Cell Activation. Front Immunol 2020; 11:584210. [PMID: 33178217 PMCID: PMC7596649 DOI: 10.3389/fimmu.2020.584210] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 08/20/2020] [Indexed: 11/13/2022] Open
Abstract
Mast cells play a key role in the regulation of innate and adaptive immunity and are involved in pathogenesis of many inflammatory and allergic diseases. The most studied mechanism of mast cell activation is mediated by the interaction of antigens with immunoglobulin E (IgE) and a subsequent binding with the high-affinity receptor Fc epsilon RI (FcεRI). Increasing evidences indicated that mitochondria are actively involved in the FcεRI-dependent activation of this type of cells. Here, we discuss changes in energy metabolism and mitochondrial dynamics during IgE-antigen stimulation of mast cells. We reviewed the recent data with regards to the role played by mitochondrial membrane potential, mitochondrial calcium ions (Ca2+) influx and reactive oxygen species (ROS) in mast cell FcεRI-dependent activation. Additionally, in the present review we have discussed the crucial role played by the pyruvate dehydrogenase (PDH) complex, transcription factors signal transducer and activator of transcription 3 (STAT3) and microphthalmia-associated transcription factor (MITF) in the development and function of mast cells. These two transcription factors besides their nuclear localization were also found to translocate in to the mitochondria and functions as direct modulators of mitochondrial activity. Studying the role played by mast cell mitochondria following their activation is essential for expanding our basic knowledge about mast cell physiological functions and would help to design mitochondria-targeted anti-allergic and anti-inflammatory drugs.
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Affiliation(s)
- Maria A. Chelombitko
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Boris V. Chernyak
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Artem V. Fedorov
- Department of Cell Biology and Histology, Biology Faculty, Lomonosov Moscow State University, Moscow, Russia
| | - Roman A. Zinovkin
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- Institute of Molecular Medicine, I.M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Ehud Razin
- Department of Biochemistry and Molecular Biology, School of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Lakhsmi Bhargavi Paruchuru
- Department of Biochemistry and Molecular Biology, School of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
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9
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Galgano D, Soheili T, Voss M, Torralba-Raga L, Tesi B, Cichocki F, Andre I, Rettig J, Cavazzana M, Bryceson Y. Alternative UNC13D Promoter Encodes a Functional Munc13-4 Isoform Predominantly Expressed in Lymphocytes and Platelets. Front Immunol 2020; 11:1154. [PMID: 32582217 PMCID: PMC7296141 DOI: 10.3389/fimmu.2020.01154] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 05/11/2020] [Indexed: 12/17/2022] Open
Abstract
Autosomal recessive mutations in genes required for cytotoxicity are causative of a life-threatening, early-onset hyperinflammatory syndrome termed familial hemophagocytic lymphohistiocytosis (FHL). Mutations in UNC13D cause FHL type 3. UNC13D encodes Munc13-4, a member of the Unc13 protein family which control SNARE complex formation and vesicle fusion. We have previously identified FHL3-associated mutations in the first intron of UNC13D which control transcription from an alternative transcriptional start site. Using isoform specific antibodies, we demonstrate that this alternative Munc13-4 isoform with a unique N-terminus is preferentially expressed in human lymphocytes and platelets, as compared to the conventional isoform that was mostly expressed in monocytes and neutrophils. The distinct N-terminal of the two isoforms did not impact on Munc13-4 localization or trafficking to the immunological synapse of cytotoxic T cells. Moreover, ectopic expression of both isoforms efficiently restored exocytosis by FHL3 patient-derived Munc13-4 deficient T cells. Thus, we demonstrate that the conventional and alternative Munc13-4 isoforms have different expression pattern in hematopoietic cell subsets, but display similar localization and contribution to T cell exocytosis. The use of an alternative transcriptional starting site (TSS) in lymphocytes and platelets could be selected for increasing the overall levels of Munc13-4 expression for efficient secretory granule release.
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Affiliation(s)
- Donatella Galgano
- Department of Medicine, Center for Hematology and Regenerative Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Tayebeh Soheili
- Human Lymphohematopoiesis Laboratory, INSERM UMR 1163, IMAGINE Institute, Paris, France
| | - Matthias Voss
- Department of Medicine, Center for Hematology and Regenerative Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Lamberto Torralba-Raga
- Department of Medicine, Center for Hematology and Regenerative Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Bianca Tesi
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Frank Cichocki
- Division of Hematology, Oncology and Transplantation, University of Minnesota, Minneapolis, MN, United States
| | - Isabelle Andre
- Human Lymphohematopoiesis Laboratory, INSERM UMR 1163, IMAGINE Institute, Paris, France.,Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, Paris, France
| | - Jens Rettig
- Cellular Neurophysiology Laboratory, Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Marina Cavazzana
- Human Lymphohematopoiesis Laboratory, INSERM UMR 1163, IMAGINE Institute, Paris, France.,Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, Paris, France.,Biotherapy Department, Hôpital Necker-Enfants malades, Assistance Publique-Hôpitaux de Paris, Paris, France.,Biotherapy Clinical Investigation Center, Groupe Hospitalier Universitaire Ouest, Assistance Publique-Hôpitaux de Paris, INSERM, Paris, France
| | - Yenan Bryceson
- Department of Medicine, Center for Hematology and Regenerative Medicine, Karolinska Institutet, Stockholm, Sweden.,Broegelmann Research Laboratory, Department of Clinical Sciences, University of Bergen, Bergen, Norway
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10
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Hays CL, Grassmeyer JJ, Wen X, Janz R, Heidelberger R, Thoreson WB. Simultaneous Release of Multiple Vesicles from Rods Involves Synaptic Ribbons and Syntaxin 3B. Biophys J 2019; 118:967-979. [PMID: 31653448 DOI: 10.1016/j.bpj.2019.10.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 09/25/2019] [Accepted: 10/03/2019] [Indexed: 02/05/2023] Open
Abstract
First proposed as a specialized mode of release at sensory neurons possessing ribbon synapses, multivesicular release has since been described throughout the central nervous system. Many aspects of multivesicular release remain poorly understood. We explored mechanisms underlying simultaneous multivesicular release at ribbon synapses in salamander retinal rod photoreceptors. We assessed spontaneous release presynaptically by recording glutamate transporter anion currents (IA(glu)) in rods. Spontaneous IA(glu) events were correlated in amplitude and kinetics with simultaneously measured miniature excitatory postsynaptic currents in horizontal cells. Both measures indicated that a significant fraction of events is multiquantal, with an analysis of IA(glu) revealing that multivesicular release constitutes ∼30% of spontaneous release events. IA(glu) charge transfer increased linearly with event amplitude showing that larger events involve greater glutamate release. The kinetics of large and small IA(glu) events were identical as were rise times of large and small miniature excitatory postsynaptic currents, indicating that the release of multiple vesicles during large events is highly synchronized. Effects of exogenous Ca2+ buffers suggested that multiquantal, but not uniquantal, release occurs preferentially near Ca2+ channels clustered beneath synaptic ribbons. Photoinactivation of ribbons reduced the frequency of spontaneous multiquantal events without affecting uniquantal release frequency, showing that spontaneous multiquantal release requires functional ribbons. Although both occur at ribbon-style active zones, the absence of cross-depletion indicates that evoked and spontaneous multiquantal release from ribbons involve different vesicle pools. Introducing an inhibitory peptide into rods to interfere with the SNARE protein, syntaxin 3B, selectively reduced multiquantal event frequency. These results support the hypothesis that simultaneous multiquantal release from rods arises from homotypic fusion among neighboring vesicles on ribbons and involves syntaxin 3B.
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Affiliation(s)
- Cassandra L Hays
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska; Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, Nebraska
| | - Justin J Grassmeyer
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, Nebraska; Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska
| | - Xiangyi Wen
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, Nebraska; West China Hospital, Sichuan University, Chengdu, Sichuan, P.R. China
| | - Roger Janz
- Department of Neurobiology and Anatomy, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas; The University of Texas MD Anderson Cancer Center University of Texas Health Graduate School of Biomedical Sciences, Houston, Texas
| | - Ruth Heidelberger
- Department of Neurobiology and Anatomy, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas; The University of Texas MD Anderson Cancer Center University of Texas Health Graduate School of Biomedical Sciences, Houston, Texas
| | - Wallace B Thoreson
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, Nebraska; Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska.
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11
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Delevoye C, Marks MS, Raposo G. Lysosome-related organelles as functional adaptations of the endolysosomal system. Curr Opin Cell Biol 2019; 59:147-158. [PMID: 31234051 PMCID: PMC6726539 DOI: 10.1016/j.ceb.2019.05.003] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/10/2019] [Accepted: 05/13/2019] [Indexed: 12/19/2022]
Abstract
Unique functions of specialised cells such as those of the immune and haemostasis systems, skin, blood vessels, lung, and bone require specialised compartments, collectively referred to as lysosome-related organelles (LROs), that share features of endosomes and lysosomes. LROs harbour unique morphological features and cell type-specific contents, and most if not all undergo regulated secretion for diverse functions. Ongoing research, largely driven by analyses of inherited diseases and their model systems, is unravelling the mechanisms involved in LRO generation, maturation, transport and secretion. A molecular understanding of these features will provide targets and markers that can be exploited for diagnosis and therapy of a myriad of diseases.
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Affiliation(s)
- Cédric Delevoye
- Structure and Membrane Compartments, Institut Curie, Paris Sciences and Lettres Research University, Centre National de la Recherche Scientifique, UMR144, Paris, France
| | - Michael S Marks
- Dept. of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, PA 19104, USA; Dept. of Pathology and Laboratory Medicine and Dept. of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Graça Raposo
- Structure and Membrane Compartments, Institut Curie, Paris Sciences and Lettres Research University, Centre National de la Recherche Scientifique, UMR144, Paris, France.
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12
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Klein O, Sagi-Eisenberg R. Anaphylactic Degranulation of Mast Cells: Focus on Compound Exocytosis. J Immunol Res 2019; 2019:9542656. [PMID: 31011586 PMCID: PMC6442490 DOI: 10.1155/2019/9542656] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Accepted: 12/26/2018] [Indexed: 01/15/2023] Open
Abstract
Anaphylaxis is a notorious type 2 immune response which may result in a systemic response and lead to death. A precondition for the unfolding of the anaphylactic shock is the secretion of inflammatory mediators from mast cells in response to an allergen, mostly through activation of the cells via the IgE-dependent pathway. While mast cells are specialized secretory cells that can secrete through a variety of exocytic modes, the most predominant mode exerted by the mast cell during anaphylaxis is compound exocytosis-a specialized form of regulated exocytosis where secretory granules fuse to one another. Here, we review the modes of regulated exocytosis in the mast cell and focus on compound exocytosis. We review historical landmarks in the research of compound exocytosis in mast cells and the methods available for investigating compound exocytosis. We also review the molecular mechanisms reported to underlie compound exocytosis in mast cells and expand further with reviewing key findings from other cell types. Finally, we discuss the possible reasons for the mast cell to utilize compound exocytosis during anaphylaxis, the conflicting evidence in different mast cell models, and the open questions in the field which remain to be answered.
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Affiliation(s)
- Ofir Klein
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ronit Sagi-Eisenberg
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
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13
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Dingjan I, Linders PTA, Verboogen DRJ, Revelo NH, Ter Beest M, van den Bogaart G. Endosomal and Phagosomal SNAREs. Physiol Rev 2018; 98:1465-1492. [PMID: 29790818 DOI: 10.1152/physrev.00037.2017] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein family is of vital importance for organelle communication. The complexing of cognate SNARE members present in both the donor and target organellar membranes drives the membrane fusion required for intracellular transport. In the endocytic route, SNARE proteins mediate trafficking between endosomes and phagosomes with other endosomes, lysosomes, the Golgi apparatus, the plasma membrane, and the endoplasmic reticulum. The goal of this review is to provide an overview of the SNAREs involved in endosomal and phagosomal trafficking. Of the 38 SNAREs present in humans, 30 have been identified at endosomes and/or phagosomes. Many of these SNAREs are targeted by viruses and intracellular pathogens, which thereby reroute intracellular transport for gaining access to nutrients, preventing their degradation, and avoiding their detection by the immune system. A fascinating picture is emerging of a complex transport network with multiple SNAREs being involved in consecutive trafficking routes.
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Affiliation(s)
- Ilse Dingjan
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; and Department of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen , Groningen , The Netherlands
| | - Peter T A Linders
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; and Department of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen , Groningen , The Netherlands
| | - Danielle R J Verboogen
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; and Department of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen , Groningen , The Netherlands
| | - Natalia H Revelo
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; and Department of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen , Groningen , The Netherlands
| | - Martin Ter Beest
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; and Department of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen , Groningen , The Netherlands
| | - Geert van den Bogaart
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; and Department of Molecular Immunology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen , Groningen , The Netherlands
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14
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Madera-Salcedo IK, Danelli L, Tiwari N, Dema B, Pacreau E, Vibhushan S, Birnbaum J, Agabriel C, Liabeuf V, Klingebiel C, Menasche G, Macias-Silva M, Benhamou M, Charles N, González-Espinosa C, Vitte J, Blank U. Tomosyn functions as a PKCδ-regulated fusion clamp in mast cell degranulation. Sci Signal 2018; 11:11/537/eaan4350. [DOI: 10.1126/scisignal.aan4350] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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15
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Messenger SW, Woo SS, Sun Z, Martin TFJ. A Ca 2+-stimulated exosome release pathway in cancer cells is regulated by Munc13-4. J Cell Biol 2018; 217:2877-2890. [PMID: 29930202 PMCID: PMC6080937 DOI: 10.1083/jcb.201710132] [Citation(s) in RCA: 136] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 02/22/2018] [Accepted: 04/02/2018] [Indexed: 12/21/2022] Open
Abstract
Cancer cells secrete copious amounts of exosomes, and elevated intracellular Ca2+ is critical for tumor progression and metastasis, but the underlying cellular mechanisms are unknown. Munc13-4 is a Ca2+-dependent SNAP receptor- and Rab-binding protein required for Ca2+-dependent membrane fusion. Here we show that acute elevation of Ca2+ in cancer cells stimulated a fivefold increase in CD63+, CD9+, and ALIX+ exosome release that was eliminated by Munc13-4 knockdown and not restored by Ca2+ binding-deficient Munc13-4 mutants. Direct imaging of CD63-pHluorin exosome release confirmed its Munc13-4 dependence. Depletion of Munc13-4 in highly aggressive breast carcinoma MDA-MB-231 cells reduced the size of CD63+ multivesicular bodies (MVBs), indicating a role for Munc13-4 in MVB maturation. Munc13-4 used a Rab11-dependent trafficking pathway to generate MVBs competent for exosome release. Membrane type 1 matrix metalloproteinase trafficking to MVBs by a Rab11-dependent pathway was also Munc13-4 dependent, and Munc13-4 depletion reduced extracellular matrix degradation. These studies identify a novel Ca2+- and Munc13-4-dependent pathway that underlies increased exosome release by cancer cells.
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Affiliation(s)
- Scott W Messenger
- Department of Biochemistry University of Wisconsin-Madison, Madison, WI
| | - Sang Su Woo
- Department of Biochemistry University of Wisconsin-Madison, Madison, WI
| | - Zhongze Sun
- Department of Biochemistry University of Wisconsin-Madison, Madison, WI
| | - Thomas F J Martin
- Department of Biochemistry University of Wisconsin-Madison, Madison, WI
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16
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Bruinsma S, James DJ, Quintana Serrano M, Esquibel J, Woo SS, Kielar-Grevstad E, Crummy E, Qurashi R, Kowalchyk JA, Martin TFJ. Small molecules that inhibit the late stage of Munc13-4-dependent secretory granule exocytosis in mast cells. J Biol Chem 2018; 293:8217-8229. [PMID: 29615494 PMCID: PMC5971468 DOI: 10.1074/jbc.ra117.001547] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 03/30/2018] [Indexed: 01/05/2023] Open
Abstract
Ca2+-dependent secretory granule fusion with the plasma membrane is the final step for the exocytic release of inflammatory mediators, neuropeptides, and peptide hormones. Secretory cells use a similar protein machinery at late steps in the regulated secretory pathway, employing protein isoforms from the Rab, Sec1/Munc18, Munc13/CAPS, SNARE, and synaptotagmin protein families. However, no small-molecule inhibitors of secretory granule exocytosis that target these proteins are currently available but could have clinical utility. Here we utilized a high-throughput screen of a 25,000-compound library that identified 129 small-molecule inhibitors of Ca2+-triggered secretory granule exocytosis in RBL-2H3 mast cells. These inhibitors broadly fell into six different chemical classes, and follow-up permeable cell and liposome fusion assays identified the target for one class of these inhibitors. A family of 2-aminobenzothiazoles (termed benzothiazole exocytosis inhibitors or bexins) was found to inhibit mast cell secretory granule fusion by acting on a Ca2+-dependent, C2 domain–containing priming factor, Munc13-4. Our findings further indicated that bexins interfere with Munc13-4–membrane interactions and thereby inhibit Munc13-4–dependent membrane fusion. We conclude that bexins represent a class of specific secretory pathway inhibitors with potential as therapeutic agents.
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Affiliation(s)
- Stephen Bruinsma
- Department of Biochemistry, University of Wisconsin, Madison Wisconsin 53706
| | - Declan J James
- Department of Biochemistry, University of Wisconsin, Madison Wisconsin 53706
| | | | - Joseph Esquibel
- Department of Biochemistry, University of Wisconsin, Madison Wisconsin 53706
| | - Sang Su Woo
- Department of Biochemistry, University of Wisconsin, Madison Wisconsin 53706
| | | | - Ellen Crummy
- Department of Biochemistry, University of Wisconsin, Madison Wisconsin 53706
| | - Rehan Qurashi
- Department of Biochemistry, University of Wisconsin, Madison Wisconsin 53706
| | - Judy A Kowalchyk
- Department of Biochemistry, University of Wisconsin, Madison Wisconsin 53706
| | - Thomas F J Martin
- Department of Biochemistry, University of Wisconsin, Madison Wisconsin 53706.
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17
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Rodarte EM, Ramos MA, Davalos AJ, Moreira DC, Moreno DS, Cardenas EI, Rodarte AI, Petrova Y, Molina S, Rendon LE, Sanchez E, Breaux K, Tortoriello A, Manllo J, Gonzalez EA, Tuvim MJ, Dickey BF, Burns AR, Heidelberger R, Adachi R. Munc13 proteins control regulated exocytosis in mast cells. J Biol Chem 2017; 293:345-358. [PMID: 29141910 DOI: 10.1074/jbc.m117.816884] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 11/02/2017] [Indexed: 01/01/2023] Open
Abstract
Mast cells (MCs) are involved in host defenses against pathogens and inflammation. Stimulated MCs release substances stored in their granules via regulated exocytosis. In other cell types, Munc13 (mammalian homolog of Caenorhabditis elegans uncoordinated gene 13) proteins play essential roles in regulated exocytosis. Here, we found that MCs express Munc13-2 and -4, and we studied their roles using global and conditional knock-out (KO) mice. In a model of systemic anaphylaxis, we found no difference between WT and Munc13-2 KO mice, but global and MC-specific Munc13-4 KO mice developed less hypothermia. This protection correlated with lower plasma histamine levels and with histological evidence of defective MC degranulation but not with changes in MC development, distribution, numbers, or morphology. In vitro assays revealed that the defective response in Munc13-4-deficient MCs was limited to regulated exocytosis, leaving other MC secretory effector responses intact. Single cell capacitance measurements in MCs from mouse mutants differing in Munc13-4 expression levels in their MCs revealed that as levels of Munc13-4 decrease, the rate of exocytosis declines first, and then the total amount of exocytosis decreases. A requirement for Munc13-2 in MC exocytosis was revealed only in the absence of Munc13-4. Electrophysiology and EM studies uncovered that the number of multigranular compound events (i.e. granule-to-granule homotypic fusion) was severely reduced in the absence of Munc13-4. We conclude that although Munc13-2 plays a minor role, Munc13-4 is essential for regulated exocytosis in MCs, and that this MC effector response is required for a full anaphylactic response.
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Affiliation(s)
- Elsa M Rodarte
- Department of Pulmonary Medicine, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030; Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Monterrey, Nuevo León 64710, México
| | - Marco A Ramos
- Department of Pulmonary Medicine, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030
| | - Alfredo J Davalos
- Department of Pulmonary Medicine, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030; Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Monterrey, Nuevo León 64710, México
| | - Daniel C Moreira
- Department of Pulmonary Medicine, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030; Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Monterrey, Nuevo León 64710, México
| | - David S Moreno
- Department of Pulmonary Medicine, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030; Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Monterrey, Nuevo León 64710, México
| | - Eduardo I Cardenas
- Department of Pulmonary Medicine, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030; Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Monterrey, Nuevo León 64710, México
| | - Alejandro I Rodarte
- Department of Pulmonary Medicine, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030; Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Monterrey, Nuevo León 64710, México
| | - Youlia Petrova
- Department of Pulmonary Medicine, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030
| | - Sofia Molina
- Department of Pulmonary Medicine, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030; Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Monterrey, Nuevo León 64710, México
| | - Luis E Rendon
- Department of Pulmonary Medicine, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030
| | - Elizabeth Sanchez
- Department of Pulmonary Medicine, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030
| | - Keegan Breaux
- Department of Pulmonary Medicine, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030
| | - Alejandro Tortoriello
- Department of Pulmonary Medicine, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030; Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Monterrey, Nuevo León 64710, México
| | - John Manllo
- Department of Pulmonary Medicine, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030
| | - Erika A Gonzalez
- Department of Pulmonary Medicine, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030; Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Monterrey, Nuevo León 64710, México
| | - Michael J Tuvim
- Department of Pulmonary Medicine, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030
| | - Burton F Dickey
- Department of Pulmonary Medicine, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030
| | - Alan R Burns
- College of Optometry, University of Houston, Houston, Texas 77204
| | - Ruth Heidelberger
- Department of Neurobiology and Anatomy, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas 77030
| | - Roberto Adachi
- Department of Pulmonary Medicine, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030.
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18
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Klein O, Roded A, Zur N, Azouz NP, Pasternak O, Hirschberg K, Hammel I, Roche PA, Yatsu A, Fukuda M, Galli SJ, Sagi-Eisenberg R. Rab5 is critical for SNAP23 regulated granule-granule fusion during compound exocytosis. Sci Rep 2017; 7:15315. [PMID: 29127297 PMCID: PMC5681557 DOI: 10.1038/s41598-017-15047-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 10/19/2017] [Indexed: 12/22/2022] Open
Abstract
Compound exocytosis is considered the most massive mode of exocytosis, during which the membranes of secretory granules (SGs) fuse with each other to form a channel through which the entire contents of their granules is released. The underlying mechanisms of compound exocytosis remain largely unresolved. Here we show that the small GTPase Rab5, a known regulator of endocytosis, is pivotal for compound exocytosis in mast cells. Silencing of Rab5 shifts receptor-triggered secretion from a compound to a full exocytosis mode, in which SGs individually fuse with the plasma membrane. Moreover, we show that Rab5 is essential for FcεRI-triggered association of the SNARE protein SNAP23 with the SGs. Direct evidence is provided for SNAP23 involvement in homotypic SG fusion that occurs in the activated cells. Finally, we show that this fusion event is prevented by inhibition of the IKKβ2 kinase, however, neither a phosphorylation-deficient nor a phosphomimetic mutant of SNAP23 can mediate homotypic SG fusion in triggered cells. Taken together our findings identify Rab5 as a heretofore-unrecognized regulator of compound exocytosis that is essential for SNAP23-mediated granule-granule fusion. Our results also implicate phosphorylation cycles in controlling SNAP23 SNARE function in homotypic SG fusion.
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Affiliation(s)
- Ofir Klein
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Amit Roded
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Neta Zur
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Nurit P Azouz
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel.,Division of Allergy and Immunology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, USA
| | - Olga Pasternak
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Koret Hirschberg
- Department of Pathology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Ilan Hammel
- Department of Pathology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Paul A Roche
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, 20892, USA
| | - Ayaka Yatsu
- Laboratory of Membrane Trafficking Mechanisms, Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Miyagi, 980-8578, Japan
| | - Mitsunori Fukuda
- Laboratory of Membrane Trafficking Mechanisms, Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Miyagi, 980-8578, Japan
| | - Stephen J Galli
- Departments of Pathology and of Microbiology and Immunology, and Sean N. Parker Center for Allergy and Asthma Research, Stanford University School of Medicine, Stanford, California, 94305-5176, USA
| | - Ronit Sagi-Eisenberg
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel.
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19
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Zhang X, Jiang S, Mitok KA, Li L, Attie AD, Martin TFJ. BAIAP3, a C2 domain-containing Munc13 protein, controls the fate of dense-core vesicles in neuroendocrine cells. J Cell Biol 2017. [PMID: 28626000 PMCID: PMC5496627 DOI: 10.1083/jcb.201702099] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Zhang et al. conducted a siRNA screen of C2 domain proteins involved in regulated peptide secretion. One of the hits, a Munc13 family member BAIAP3, was characterized as endosome localized involved in post-exocytic dense-core vesicle protein recycling to the TGN. BAIAP3 knockdown inhibited dense-core vesicle maturation/stability in neuroendocrine/endocrine cells. Dense-core vesicle (DCV) exocytosis is a SNARE (soluble N-ethylmaleimide–sensitive fusion attachment protein receptor)-dependent anterograde trafficking pathway that requires multiple proteins for regulation. Several C2 domain–containing proteins are known to regulate Ca2+-dependent DCV exocytosis in neuroendocrine cells. In this study, we identified others by screening all (∼139) human C2 domain–containing proteins by RNA interference in neuroendocrine cells. 40 genes were identified, including several encoding proteins with known roles (CAPS [calcium-dependent activator protein for secretion 1], Munc13-2, RIM1, and SYT10) and many with unknown roles. One of the latter, BAIAP3, is a secretory cell–specific Munc13-4 paralog of unknown function. BAIAP3 knockdown caused accumulation of fusion-incompetent DCVs in BON neuroendocrine cells and lysosomal degradation (crinophagy) of insulin-containing DCVs in INS-1 β cells. BAIAP3 localized to endosomes was required for Golgi trans-Golgi network 46 (TGN46) recycling, exhibited Ca2+-stimulated interactions with TGN SNAREs, and underwent Ca2+-stimulated TGN recruitment. Thus, unlike other Munc13 proteins, BAIAP3 functions indirectly in DCV exocytosis by affecting DCV maturation through its role in DCV protein recycling. Ca2+ rises that stimulate DCV exocytosis may stimulate BAIAP3-dependent retrograde trafficking to maintain DCV protein homeostasis and DCV function.
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Affiliation(s)
- Xingmin Zhang
- Department of Biochemistry, University of Wisconsin, Madison, WI.,Program in Cellular and Molecular Biology, University of Wisconsin, Madison, WI
| | - Shan Jiang
- School of Pharmacy, University of Wisconsin, Madison, WI
| | - Kelly A Mitok
- Department of Biochemistry, University of Wisconsin, Madison, WI
| | - Lingjun Li
- School of Pharmacy, University of Wisconsin, Madison, WI
| | - Alan D Attie
- Department of Biochemistry, University of Wisconsin, Madison, WI
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20
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Abstract
The functions of four of the five proteins in the mammalian uncoordinated-13 (Munc13) family have been identified as priming factors in SNARE-dependent exocytosis. In this issue, Zhang et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201702099) show that the fifth member, BAIAP3 (brain-specific angiogenesis inhibitor I-associated protein 3), acts in retrograde trafficking by returning secretory vesicle material to the trans-Golgi network. In its absence, secretory vesicle formation is impaired, leading to accumulation of immature vesicles, or lysosomal vesicle degradation.
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Affiliation(s)
- Jakob B Sørensen
- Center for Neuroscience, University of Copenhagen, Copenhagen, Denmark
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