1
|
Gu C, Philipsen MH, Ewing AG. Omega-3 and -6 Fatty Acids Alter the Membrane Lipid Composition and Vesicle Size to Regulate Exocytosis and Storage of Catecholamines. ACS Chem Neurosci 2024; 15:816-826. [PMID: 38344810 PMCID: PMC10884999 DOI: 10.1021/acschemneuro.3c00741] [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: 11/15/2023] [Revised: 01/10/2024] [Accepted: 01/30/2024] [Indexed: 02/22/2024] Open
Abstract
The two essential fatty acids, alpha-linolenic acid and linoleic acid, and the higher unsaturated fatty acids synthesized from them are critical for the development and maintenance of normal brain functions. Deficiencies of these fatty acids have been shown to cause damage to the neuronal development, cognition, and locomotor function. We combined electrochemistry and imaging techniques to examine the effects of the two essential fatty acids on catecholamine release dynamics and the vesicle content as well as on the cell membrane phospholipid composition to understand how they impact exocytosis and by extension neurotransmission at the single-cell level. Incubation of either of the two fatty acids reduces the size of secretory vesicles and enables the incorporation of more double bonds into the cell membrane structure, resulting in higher membrane flexibility. This subsequently affects proteins regulating the dynamics of the exocytotic fusion pore and thereby affects exocytosis. Our data suggest a possible pathway whereby the two essential fatty acids affect the membrane structure to impact exocytosis and provide a potential treatment for diseases and impairments related to catecholamine signaling.
Collapse
Affiliation(s)
- Chaoyi Gu
- Department of Chemistry and Molecular
Biology, University of Gothenburg, 41390 Gothenburg, Sweden
| | - Mai H. Philipsen
- Department of Chemistry and Molecular
Biology, University of Gothenburg, 41390 Gothenburg, Sweden
| | - Andrew G. Ewing
- Department of Chemistry and Molecular
Biology, University of Gothenburg, 41390 Gothenburg, Sweden
| |
Collapse
|
2
|
Chang CW, Hsiao YT, Scheuer KS, Jackson MB. Full-Fusion and Kiss-and-Run in Chromaffin Cells controlled by Irreversible Vesicle Size-Dependent Fusion Pore Transitions. Cell Calcium 2022; 105:102606. [DOI: 10.1016/j.ceca.2022.102606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 05/18/2022] [Indexed: 11/02/2022]
|
3
|
He X, Ewing AG. Anionic Species Regulate Chemical Storage in Nanometer Vesicles and Amperometrically Detected Exocytotic Dynamics. J Am Chem Soc 2022; 144:4310-4314. [PMID: 35254807 PMCID: PMC8931764 DOI: 10.1021/jacs.2c00581] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Hofmeister effects have often been ignored in living organisms, although they affect the activity and functions of biological molecules. Herein, amperometry has been applied to show that the vesicular content, dynamics of exocytosis and vesicles opening, depend on the anionic species treatment. Compared to 100 μM Cl- treated chromaffin cells, a similar number of catecholamine molecules is released after chaotropic anions (ClO4- and SCN-) treatment, even though the vesicular catecholamine content significantly increases, suggesting a lower release fraction. In addition, there are opposite effects on the dynamics of vesicles release (shorter duration) and vesicle opening (longer duration) for chaotropic anions treated cells. Our results show anion-dependent vesicle release, vesicle opening, and vesicular content, providing understanding of the pharmacological and pathological processes induced by inorganic ions.
Collapse
Affiliation(s)
- Xiulan He
- Department of Chemistry and Molecular Biology, University of Gothenburg, 412 96 Gothenburg, Sweden
| | - Andrew G Ewing
- Department of Chemistry and Molecular Biology, University of Gothenburg, 412 96 Gothenburg, Sweden
| |
Collapse
|
4
|
He X, Ewing AG. Concentration of stimulant regulates initial exocytotic molecular plasticity at single cells. Chem Sci 2022; 13:1815-1822. [PMID: 35282618 PMCID: PMC8826951 DOI: 10.1039/d1sc05278k] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 01/20/2022] [Indexed: 11/21/2022] Open
Abstract
Activity-induced synaptic plasticity has been intensively studied, but is not yet well understood. We examined the temporal and concentration effects of exocytotic molecular plasticity during and immediately after chemical stimulation (30 s K+ stimulation) via single cell amperometry. Here the first and the second 15 s event periods from individual event traces were compared. Remarkably, we found that the amount of catecholamine release and release dynamics depend on the stimulant concentration. No changes were observed at 10 mM K+ stimulation, but changes observed at 30 and 50 mM (i.e., potentiation, increased number of molecules) were opposite to those at 100 mM (i.e., depression, decreased number of events), revealing changes in exocytotic plasticity based on the concentration of the stimulant solution. These results show that molecular changes initiating exocytotic plasticity can be regulated by the concentration strength of the stimulant solution. These different effects on early plasticity offer a possible link between stimulation intensity and synaptic (or adrenal) plasticity. Amperometric measurement of exocytosis (SCA) and vesicle content (IVIEC) over 15 s intervals reveals plasticity (none, potentiation, or depression), that is regulated by the concentration of stimulant solution (e.g., 30 s 10, 30, 50, and 100 mM K+).![]()
Collapse
Affiliation(s)
- Xiulan He
- Department of Chemistry and Molecular Biology, University of Gothenburg 412 96 Gothenburg Sweden
| | - Andrew G Ewing
- Department of Chemistry and Molecular Biology, University of Gothenburg 412 96 Gothenburg Sweden
| |
Collapse
|
5
|
Asadpour F, Zhang XW, Mazloum-Ardakani M, Mirzaei M, Majdi S, Ewing AG. Vesicular release dynamics are altered by the interaction between the chemical cargo and vesicle membrane lipids. Chem Sci 2021; 12:10273-10278. [PMID: 34447531 PMCID: PMC8336585 DOI: 10.1039/d1sc02247d] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 06/25/2021] [Indexed: 01/07/2023] Open
Abstract
The release of the cargo from soft vesicles, an essential process for chemical delivery, is mediated by multiple factors. Among them, the regulation by the interaction between the chemical cargo species and the vesicular membrane, widely existing in all vesicles, has not been investigated to date. Yet, these interactions hold the potential to complicate the release process. We used liposomes loaded with different monoamines, dopamine (DA) and serotonin (5-HT), to simulate vesicular release and to monitor the dynamics of chemical release from isolated vesicles during vesicle impact electrochemical cytometry (VIEC). The release of DA from liposomes presents a longer release time compared to 5-HT. Modelling the release time showed that DA filled vesicles had a higher percentage of events where the time for the peak fall was better fit to a double exponential (DblExp) decay function, suggesting multiple kinetic steps in the release. By fitting to a desorption-release model, where the transmitters adsorbed to the vesicle membrane, the dissociation rates of DA and 5-HT from the liposome membrane were estimated. DA has a lower desorption rate constant, which leads to slower DA release than that observed for 5-HT, whereas there is little difference in pore size. The alteration of vesicular release dynamics due to the interaction between the chemical cargo and vesicle membrane lipids provides an important mechanism to regulate vesicular release in chemical and physiological processes. It is highly possible that this introduces a fundamental chemical regulation difference between transmitters during exocytosis.
Collapse
Affiliation(s)
- Farzaneh Asadpour
- Department of Chemistry and Molecular Biology, University of Gothenburg 41296 Gothenburg Sweden .,Department of Chemistry, Faculty of Science, Yazd University Yazd 89195-741 Iran
| | - Xin-Wei Zhang
- Department of Chemistry and Molecular Biology, University of Gothenburg 41296 Gothenburg Sweden
| | | | - Meysam Mirzaei
- Department of Materials Science and Engineering, School of Engineering, Shiraz University Shiraz Iran
| | - Soodabeh Majdi
- Department of Chemistry and Molecular Biology, University of Gothenburg 41296 Gothenburg Sweden
| | - Andrew G Ewing
- Department of Chemistry and Molecular Biology, University of Gothenburg 41296 Gothenburg Sweden
| |
Collapse
|
6
|
He X, Ewing AG. Counteranions in the Stimulation Solution Alter the Dynamics of Exocytosis Consistent with the Hofmeister Series. J Am Chem Soc 2020; 142:12591-12595. [PMID: 32598145 PMCID: PMC7386575 DOI: 10.1021/jacs.0c05319] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
![]()
We
show that the Hofmeister series of ions can be used to explain
the cellular changes in exocytosis observed by single-cell amperometry
for different counteranions. The formation, expansion, and closing
of the membrane fusion pore during exocytosis was found to be strongly
dependent on the counteranion species in solution. With stimulation
of chaotropic anions (e.g., ClO4–), the
expansion and closing time of the fusion pore are longer, suggesting
chaotropes can extend the duration of exocytosis compared with kosmotropic
anions (e.g., Cl–). At a concentration of 30 mM,
the two parameters (e.g., t1/2 and tfall) that define the duration of exocytosis
vary with the Hofmeister series (Cl– < Br– < NO3– ≤ ClO4– < SCN–). More interestingly,
fewer (e.g., Nfoot/Nevents) and smaller (e.g., Ifoot) prespike events are observed when chaotropes are counterions in
the stimulation solution, and the values can be sorted by the reverse
Hofmeister series (Cl– ≥ Br– > NO3– > ClO4– > SCN–). Based on ion specificity,
an adsorption-repulsion
mechanism, we suggest that the exocytotic Hofmeister series effect
originates from a looser swelling lipid bilayer structure due to the
adsorption and electrostatic repulsion of chaotropes on the hydrophobic
portion of the membrane. Our results provide a chemical link between
the Hofmeister series and the cellular process of neurotransmitter
release via exocytosis and provide a better physical framework to
understand this important phenomenon.
Collapse
Affiliation(s)
- Xiulan He
- Department of Chemistry and Molecular Biology, University of Gothenburg, 41296 Gothenburg, Sweden
| | - Andrew G Ewing
- Department of Chemistry and Molecular Biology, University of Gothenburg, 41296 Gothenburg, Sweden
| |
Collapse
|
7
|
Jackson MB, Hsiao YT, Chang CW. Fusion Pore Expansion and Contraction during Catecholamine Release from Endocrine Cells. Biophys J 2020; 119:219-231. [PMID: 32562620 DOI: 10.1016/j.bpj.2020.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 04/26/2020] [Accepted: 06/01/2020] [Indexed: 11/28/2022] Open
Abstract
Amperometry recording reveals the exocytosis of catecholamine from individual vesicles as a sequential process, typically beginning slowly with a prespike foot, accelerating sharply to initiate a spike, reaching a peak, and then decaying. This complex sequence reflects the interplay between diffusion, flux through a fusion pore, and possibly dissociation from a vesicle's dense core. In an effort to evaluate the impacts of these factors, a model was developed that combines diffusion with flux through a static pore. This model accurately recapitulated the rapid phase of a spike but generated relations between spike shape parameters that differed from the relations observed experimentally. To explore the possible role of fusion pore dynamics, a transformation of amperometry current was introduced that yields fusion pore permeability divided by vesicle volume (g/V). Applying this transform to individual fusion events yielded a highly characteristic time course. g/V initially tracks the current, increasing ∼15-fold from the prespike foot to the spike peak. After the peak, g/V unexpectedly declines and settles into a plateau that indicates the presence of a stable postspike pore. g/V of the postspike pore varies greatly between events and has an average that is ∼3.5-fold below the peak value and ∼4.5-fold above the prespike value. The postspike pore persists and is stable for tens of milliseconds, as long as catecholamine flux can be detected. Applying the g/V transform to rare events with two peaks revealed a stepwise increase in g/V during the second peak. The g/V transform offers an interpretation of amperometric current in terms of fusion pore dynamics and provides a, to our knowledge, new frameworkfor analyzing the actions of proteins that alter spike shape. The stable postspike pore follows from predictions of lipid bilayer elasticity and offers an explanation for previous reports of prolonged hormone retention within fusing vesicles.
Collapse
Affiliation(s)
- Meyer B Jackson
- University of Wisconsin Medical School, Department of Neuroscience, Madison, Wisconsin.
| | - Yu-Tien Hsiao
- University of Wisconsin Medical School, Department of Neuroscience, Madison, Wisconsin
| | - Che-Wei Chang
- University of Wisconsin Medical School, Department of Neuroscience, Madison, Wisconsin; Gladstone Research Institute, University of California, San Francisco, San Francisco, California
| |
Collapse
|
8
|
Larsson A, Majdi S, Oleinick A, Svir I, Dunevall J, Amatore C, Ewing AG. Intracellular Electrochemical Nanomeasurements Reveal that Exocytosis of Molecules at Living Neurons is Subquantal and Complex. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201914564] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Anna Larsson
- Department of Chemistry and Molecular BiologyUniversity of Gothenburg Kemivägen 10 412 96 Gothenburg Sweden
| | - Soodabeh Majdi
- Department of Chemistry and Molecular BiologyUniversity of Gothenburg Kemivägen 10 412 96 Gothenburg Sweden
| | - Alexander Oleinick
- CNRS, Ecole Normale Superieure—PSL research UniversitySorbonne University UMR 8640 “PASTEUR”Departement de Chimie 24 rue Lhomond 75005 Paris France
| | - Irina Svir
- CNRS, Ecole Normale Superieure—PSL research UniversitySorbonne University UMR 8640 “PASTEUR”Departement de Chimie 24 rue Lhomond 75005 Paris France
| | - Johan Dunevall
- Department of Chemistry and Molecular BiologyUniversity of Gothenburg Kemivägen 10 412 96 Gothenburg Sweden
| | - Christian Amatore
- CNRS, Ecole Normale Superieure—PSL research UniversitySorbonne University UMR 8640 “PASTEUR”Departement de Chimie 24 rue Lhomond 75005 Paris France
- State Key Laboratory of Physical Chemistry of Solid SurfacesCollege of Chemistry and Chemical EngineeringXiamen University 361005 Xiamen China
| | - Andrew G. Ewing
- Department of Chemistry and Molecular BiologyUniversity of Gothenburg Kemivägen 10 412 96 Gothenburg Sweden
| |
Collapse
|
9
|
Roberts JG, Mitchell EC, Dunaway LE, McCarty GS, Sombers LA. Carbon-Fiber Nanoelectrodes for Real-Time Discrimination of Vesicle Cargo in the Native Cellular Environment. ACS NANO 2020; 14:2917-2926. [PMID: 32058693 PMCID: PMC7336535 DOI: 10.1021/acsnano.9b07318] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Carbon-fiber microelectrodes have proven to be an indispensable tool for monitoring exocytosis events using amperometry. When positioned adjacent to a cell, a traditional microdisc electrode is well suited for quantification of discrete exocytotic release events. However, the size of the electrode does not allow for intracellular electrochemical measurements, and the amperometric approach cannot distinguish between the catecholamines that are released. In this work, carbon nanoelectrodes were developed to permit selective electrochemical sampling of nanoscale vesicles in the cell cytosol. Classical voltammetric techniques and electron microscopy were used to characterize the nanoelectrodes, which were ∼5 μm long and sharpened to a nanometer-scale tip that could be wholly inserted into individual neuroendocrine cells. The nanoelectrodes were coupled with fast-scan cyclic voltammetry to distinguish secretory granules containing epinephrine from other catecholamine-containing granules encountered in the native cellular environment. Both vesicle subtypes were encountered in most cells, despite prior demonstration of populations of chromaffin cells that preferentially release one of these catecholamines. There was substantial cell-to-cell variability in relative epinephrine content, and vesicles containing epinephrine generally stored more catecholamine than the other vesicles. The carbon nanoelectrode technology thus enabled analysis of picoliter-scale biological volumes, revealing key differences between chromaffin cells at the level of the dense-core granule.
Collapse
|
10
|
Larsson A, Majdi S, Oleinick A, Svir I, Dunevall J, Amatore C, Ewing AG. Intracellular Electrochemical Nanomeasurements Reveal that Exocytosis of Molecules at Living Neurons is Subquantal and Complex. Angew Chem Int Ed Engl 2020; 59:6711-6714. [PMID: 31967714 DOI: 10.1002/anie.201914564] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Indexed: 11/07/2022]
Abstract
Since the early work of Bernard Katz, the process of cellular chemical communication through exocytosis, quantal release, has been considered to be all or none. Recent evidence has shown exocytosis to be partial or "subquantal" at single-cell model systems, but there is a need to understand this at communicating nerve cells. Partial release allows nerve cells to control the signal at the site of release during individual events, for which the smaller the fraction released, the greater the range of regulation. Herein, we show that the fraction of the vesicular octopamine content released from a living Drosophila larval neuromuscular neuron is very small. The percentage of released molecules was found to be only 4.5 % for simple events and 10.7 % for complex (i.e., oscillating or flickering) events. This large content, combined with partial release controlled by fluctuations of the fusion pore, offers presynaptic plasticity that can be widely regulated.
Collapse
Affiliation(s)
- Anna Larsson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemivägen 10, 412 96, Gothenburg, Sweden
| | - Soodabeh Majdi
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemivägen 10, 412 96, Gothenburg, Sweden
| | - Alexander Oleinick
- CNRS, Ecole Normale Superieure-PSL research University, Sorbonne University UMR 8640 "PASTEUR", Departement de Chimie, 24 rue Lhomond, 75005, Paris, France
| | - Irina Svir
- CNRS, Ecole Normale Superieure-PSL research University, Sorbonne University UMR 8640 "PASTEUR", Departement de Chimie, 24 rue Lhomond, 75005, Paris, France
| | - Johan Dunevall
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemivägen 10, 412 96, Gothenburg, Sweden
| | - Christian Amatore
- CNRS, Ecole Normale Superieure-PSL research University, Sorbonne University UMR 8640 "PASTEUR", Departement de Chimie, 24 rue Lhomond, 75005, Paris, France
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, China
| | - Andrew G Ewing
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemivägen 10, 412 96, Gothenburg, Sweden
| |
Collapse
|
11
|
Lasič E, Trkov Bobnar S, Wilhelmsson U, Pablo Y, Pekny M, Zorec R, Stenovec M. Nestin affects fusion pore dynamics in mouse astrocytes. Acta Physiol (Oxf) 2020; 228:e13399. [PMID: 31597221 DOI: 10.1111/apha.13399] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 09/17/2019] [Accepted: 09/30/2019] [Indexed: 12/15/2022]
Abstract
AIM Astrocytes play a homeostatic role in the central nervous system and influence numerous aspects of neurophysiology via intracellular trafficking of vesicles. Intermediate filaments (IFs), also known as nanofilaments, regulate a number of cellular processes including organelle trafficking and adult hippocampal neurogenesis. We have recently demonstrated that the IF protein nestin, a marker of neural stem cells and immature and reactive astrocytes, is also expressed in some astrocytes in the unchallenged hippocampus and regulates neurogenesis through Notch signalling from astrocytes to neural stem cells, possibly via altered trafficking of vesicles containing the Notch ligand Jagged-1. METHODS We thus investigated whether nestin affects vesicle dynamics in astrocytes by examining single vesicle interactions with the plasmalemma and vesicle trafficking with high-resolution cell-attached membrane capacitance measurements and confocal microscopy. We used cell cultures of astrocytes from nestin-deficient (Nes-/- ) and wild-type (wt) mice, and fluorescent dextran and Fluo-2 to examine vesicle mobility and intracellular Ca2+ concentration respectively. RESULTS Nes-/- astrocytes exhibited altered sizes of vesicles undergoing full fission and transient fusion, altered vesicle fusion pore geometry and kinetics, decreased spontaneous vesicle mobility and altered ATP-evoked mobility. Purinergic stimulation evoked Ca2+ signalling that was slightly attenuated in Nes-/- astrocytes, which exhibited more oscillatory Ca2+ responses than wt astrocytes. CONCLUSION These results demonstrate at the single vesicle level that nestin regulates vesicle interactions with the plasmalemma and vesicle trafficking, indicating its potential role in astrocyte vesicle-based communication.
Collapse
Affiliation(s)
- Eva Lasič
- Laboratory of Neuroendocrinology‐Molecular Cell Physiology Institute of Pathophysiology Faculty of Medicine University of Ljubljana Ljubljana Slovenia
| | - Saša Trkov Bobnar
- Laboratory of Neuroendocrinology‐Molecular Cell Physiology Institute of Pathophysiology Faculty of Medicine University of Ljubljana Ljubljana Slovenia
- Celica Biomedical Ljubljana Slovenia
| | - Ulrika Wilhelmsson
- Laboratory of Astrocyte Biology and CNS Regeneration Center for Brain Repair Department of Clinical Neuroscience Institute of Neuroscience and Physiology Sahlgrenska Academy at the University of Gothenburg Gothenburg Sweden
| | - Yolanda Pablo
- Laboratory of Astrocyte Biology and CNS Regeneration Center for Brain Repair Department of Clinical Neuroscience Institute of Neuroscience and Physiology Sahlgrenska Academy at the University of Gothenburg Gothenburg Sweden
| | - Milos Pekny
- Laboratory of Astrocyte Biology and CNS Regeneration Center for Brain Repair Department of Clinical Neuroscience Institute of Neuroscience and Physiology Sahlgrenska Academy at the University of Gothenburg Gothenburg Sweden
- Florey Institute of Neuroscience and Mental Health Parkville Vic. Australia
- University of Newcastle Newcastle NSW Australia
| | - Robert Zorec
- Laboratory of Neuroendocrinology‐Molecular Cell Physiology Institute of Pathophysiology Faculty of Medicine University of Ljubljana Ljubljana Slovenia
- Celica Biomedical Ljubljana Slovenia
| | - Matjaž Stenovec
- Laboratory of Neuroendocrinology‐Molecular Cell Physiology Institute of Pathophysiology Faculty of Medicine University of Ljubljana Ljubljana Slovenia
- Celica Biomedical Ljubljana Slovenia
| |
Collapse
|
12
|
Plasticity in exocytosis revealed through the effects of repetitive stimuli affect the content of nanometer vesicles and the fraction of transmitter released. Proc Natl Acad Sci U S A 2019; 116:21409-21415. [PMID: 31570594 DOI: 10.1073/pnas.1910859116] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Electrochemical techniques with disk and nano-tip electrodes, together with calcium imaging, were used to examine the effect of short-interval repetitive stimuli on both exocytosis and vesicular content in a model cell line. We show that the number of events decreases markedly with repeated stimuli suggesting a depletion of exocytosis machinery. However, repetitive stimuli induce a more stable fusion pore, leading to an increased amount of neurotransmitter release. In contrast, the total neurotransmitter content inside the vesicles decreases after repetitive stimuli, resulting in a higher average release fraction from each event. We suggest a possible mechanism regarding a link between activity-induced plasticity and fraction of release.
Collapse
|
13
|
Mechanistic study of PpIX accumulation using the JFCR39 cell panel revealed a role for dynamin 2-mediated exocytosis. Sci Rep 2019; 9:8666. [PMID: 31209282 PMCID: PMC6572817 DOI: 10.1038/s41598-019-44981-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 05/29/2019] [Indexed: 12/21/2022] Open
Abstract
5-aminolevulinic acid (5-ALA) has recently been employed for photodynamic diagnosis (ALA-PDD) and photodynamic therapy (ALA-PDT) of various types of cancer because hyperproliferating tumor cells do not utilize oxidative phosphorylation and do not efficiently produce heme; instead, they accumulate protoporphyrin IX (PpIX), which is a precursor of heme that is activated by violet light irradiation that results in the production of red fluorescence and singlet oxygen. The efficiencies of ALA-PDD and ALA-PDT depend on the efficient cellular uptake of 5-ALA and the inefficient excretion of PpIX. We employed the JFCR39 cell panel to determine whether tumor cells originating from different tissues can produce and accumulate PpIX. We also investigated cellular factors/molecules involved in PpIX excretion by tumor cells with the JFCR39 cell panel. Unexpectedly, the expression levels of ABCG2, which has been considered to play a major role in PpIX extracellular transport, did not show a strong correlation with PpIX excretion levels in the JFCR39 cell panel, although an ABCG2 inhibitor significantly increased intracellular PpIX accumulation in several tumor cell lines. In contrast, the expression levels of dynamin 2, which is a cell membrane-associated molecule involved in exocytosis, were correlated with the PpIX excretion levels. Moreover, inhibitors of dynamin significantly suppressed PpIX excretion and increased the intracellular levels of PpIX. This is the first report demonstrating the causal relationship between dynamin 2 expression and PpIX excretion in tumor cells.
Collapse
|
14
|
Shin M, Wang Y, Borgus JR, Venton BJ. Electrochemistry at the Synapse. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2019; 12:297-321. [PMID: 30707593 PMCID: PMC6989097 DOI: 10.1146/annurev-anchem-061318-115434] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Electrochemical measurements of neurotransmitters provide insight into the dynamics of neurotransmission. In this review, we describe the development of electrochemical measurements of neurotransmitters and how they started with extrasynaptic measurements but now are pushing toward synaptic measurements. Traditionally, biosensors or fast-scan cyclic voltammetry have monitored extrasynaptic levels of neurotransmitters, such as dopamine, serotonin, adenosine, glutamate, and acetylcholine. Amperometry and electrochemical cytometry techniques have revealed mechanisms of exocytosis, suggesting partial release. Advances in nanoelectrodes now allow spatially resolved, electrochemical measurements in a synapse, which is only 20-100 nm wide. Synaptic measurements of dopamine and acetylcholine have been made. In this article, electrochemical measurements are also compared to optical imaging and mass spectrometry measurements, and while these other techniques provide enhanced spatial or chemical information, electrochemistry is best at monitoring real-time neurotransmission. Future challenges include combining electrochemistry with these other techniques in order to facilitate multisite and multianalyte monitoring.
Collapse
Affiliation(s)
| | | | - Jason R Borgus
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22901, USA;
| | - B Jill Venton
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22901, USA;
| |
Collapse
|
15
|
Ye D, Gu C, Ewing A. Using Single-Cell Amperometry and Intracellular Vesicle Impact Electrochemical Cytometry To Shed Light on the Biphasic Effects of Lidocaine on Exocytosis. ACS Chem Neurosci 2018; 9:2941-2947. [PMID: 29976059 DOI: 10.1021/acschemneuro.8b00130] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Single cell amperometry and intracellular vesicle impact electrochemical cytometry were used to examine whether lidocaine can regulate neurotransmitter release or storage for PC12 cells to explain the biphasic effects whereby it can protect neurons and improve cognitive outcome at low concentration, but can cause neurotoxicity at high concentration. We show that lidocaine affects the behavior of PC12 cell exocytosis in a concentration dependent way, which exactly corresponds to its biphasic effects. At a relatively high concentration, it shows a much narrower pore size and a longer-duration fusion pore with less monoamine released than control cells. However, at a relatively low concentration, the fusion pore is open even longer than at high concentration, and with more monoamine released than control cells. Furthermore, intracellular vesicle impact electrochemical cytometry was used to confirm that lidocaine did not change the catecholamine content of the vesicles. These data provide a mechanism for the observed biphasic effects of the drug and suggest that lidocaine influences exocytosis through multiple mechanisms.
Collapse
Affiliation(s)
- Daixin Ye
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg 412 96, Sweden
| | - Chaoyi Gu
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg 412 96, Sweden
| | - Andrew Ewing
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg 412 96, Sweden
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg 412 96, Sweden
| |
Collapse
|
16
|
Lovrić J, Najafinobar N, Dunevall J, Majdi S, Svir I, Oleinick A, Amatore C, Ewing AG. On the mechanism of electrochemical vesicle cytometry: chromaffin cell vesicles and liposomes. Faraday Discuss 2018; 193:65-79. [PMID: 27711871 DOI: 10.1039/c6fd00102e] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The mechanism of mammalian vesicle rupture onto the surface of a polarized carbon fiber microelectrode during electrochemical vesicle cytometry is investigated. It appears that following adsorption to the surface of the polarized electrode, electroporation leads to the formation of a pore at the interface between a vesicle and the electrode and this is shown to be potential dependent. The chemical cargo is then released through this pore to be oxidized at the electrode surface. This makes it possible to quantify the contents as it restricts diffusion away from the electrode and coulometric oxidation takes place. Using a bottom up approach, lipid-only transmitter-loaded liposomes were used to mimic native vesicles and the rupture events occurred much faster in comparison with native vesicles. Liposomes with added peptide in the membrane result in rupture events with a lower duration than that of liposomes and faster in comparison to native vesicles. Diffusional models have been developed and suggest that the trend in pore size is dependent on soft nanoparticle size and diffusion of the content in the nanometer vesicle. In addition, it appears that proteins form a barrier for the membrane to reach the electrode and need to move out of the way to allow close contact and electroporation. The protein dense core in vesicles matrixes is also important in the dynamics of the events in that it significantly slows diffusion through the vesicle.
Collapse
Affiliation(s)
- Jelena Lovrić
- Chalmers University of Technology, Department of Chemistry and Chemical Engineering, Kemivägen 10, 412 96 Gothenburg, Sweden.
| | - Neda Najafinobar
- Chalmers University of Technology, Department of Chemistry and Chemical Engineering, Kemivägen 10, 412 96 Gothenburg, Sweden.
| | - Johan Dunevall
- Chalmers University of Technology, Department of Chemistry and Chemical Engineering, Kemivägen 10, 412 96 Gothenburg, Sweden.
| | - Soodabeh Majdi
- University of Gothenburg, Department of Chemistry and Molecular Biology, Kemivägen 10, 412 96 Gothenburg, Sweden
| | - Irina Svir
- Ecole Normale Supérieure-PSL Research University, Département de Chimie, Sorbonne Universités-UPMC Univ. Paris 06, CNRS UMR 8640 PASTEUR, 24 rue Lhomond, 75005 Paris, France
| | - Alexander Oleinick
- Ecole Normale Supérieure-PSL Research University, Département de Chimie, Sorbonne Universités-UPMC Univ. Paris 06, CNRS UMR 8640 PASTEUR, 24 rue Lhomond, 75005 Paris, France
| | - Christian Amatore
- Ecole Normale Supérieure-PSL Research University, Département de Chimie, Sorbonne Universités-UPMC Univ. Paris 06, CNRS UMR 8640 PASTEUR, 24 rue Lhomond, 75005 Paris, France
| | - Andrew G Ewing
- Chalmers University of Technology, Department of Chemistry and Chemical Engineering, Kemivägen 10, 412 96 Gothenburg, Sweden. and University of Gothenburg, Department of Chemistry and Molecular Biology, Kemivägen 10, 412 96 Gothenburg, Sweden
| |
Collapse
|
17
|
Ye D, Ewing A. On the Action of General Anesthetics on Cellular Function: Barbiturate Alters the Exocytosis of Catecholamines in a Model Cell System. Chemphyschem 2018; 19:1173-1179. [PMID: 29356266 DOI: 10.1002/cphc.201701255] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 01/18/2018] [Indexed: 11/08/2022]
Abstract
General anesthetics are essential in many areas, however, the cellular mechanisms of anesthetic-induced amnesia and unconsciousness are incompletely understood. Exocytosis is the main mechanism of signal transduction and neuronal communication through the release of chemical transmitters from vesicles to the extracellular environment. Here, we use disk electrodes placed on top of PC12 cells to show that treatment with barbiturate induces fewer molecules released during exocytosis and changes the event dynamics perhaps by inducing a less stable fusion pore that is prone to close faster during partial exocytosis. Larger events are essentially abolished. However, use of intracellular vesicle impact electrochemical cytometry using a nano-tip electrode inserted into a cell shows that the distribution of vesicle transmitter content does not change after barbiturate treatment. This indicates that barbiturate selectively alters the pore size of larger events or perhaps differentially between types of vesicles. Alteration of exocytosis in this manner could be linked to the effects of general anesthetics on memory loss.
Collapse
Affiliation(s)
- Daixin Ye
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemivägen 10, 41296, Gothenburg, Sweden
| | - Andrew Ewing
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemivägen 10, 41296, Gothenburg, Sweden.,Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Kemivägen 10, 41296, Gothenburg, Sweden
| |
Collapse
|
18
|
Jackson MB. Chemistry in a vesicle. J Gen Physiol 2017; 149:893-896. [PMID: 28899933 PMCID: PMC5694936 DOI: 10.1085/jgp.201711894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Slow fusion pore expansion could retain molecules within vesicles, enabling a chemical reaction that modifies secreted products.
Collapse
Affiliation(s)
- Meyer B Jackson
- Department of Neuroscience, University of Wisconsin, Madison, WI
| |
Collapse
|
19
|
How does the stimulus define exocytosis in adrenal chromaffin cells? Pflugers Arch 2017; 470:155-167. [DOI: 10.1007/s00424-017-2052-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 07/28/2017] [Accepted: 08/01/2017] [Indexed: 12/28/2022]
|
20
|
Li X, Dunevall J, Ren L, Ewing AG. Mechanistic Aspects of Vesicle Opening during Analysis with Vesicle Impact Electrochemical Cytometry. Anal Chem 2017; 89:9416-9423. [PMID: 28776974 DOI: 10.1021/acs.analchem.7b02226] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Vesicle impact electrochemical cytometry (VIEC) has been used to quantify the vesicular transmitter content in mammalian vesicles. In the present study, we studied the mechanism of VIEC by quantifying the catecholamine content in single vesicles isolated from pheochromocytoma (PC12) cells. These vesicles contain about one tenth of the catecholamine compared with adrenal chromaffin vesicles. The existence of a prespike foot for many events suggests the formation of an initial transiently stable pore at the beginning of vesicle rupture. Increasing the detection temperature from 6 to 30 °C increases the possibility of vesicle rupture on the electrode, implying that there is a temperature-dependent process that facilitates electroporation. Natively larger vesicles are shown to rupture earlier and more frequently than smaller ones in VIEC. Likewise, manipulating vesicle content and size with drugs leads to similar trends. These data support the hypothesis that electroporation is the primary force for pore opening in VIEC. We further hypothesize that a critical step for initiating vesicle opening by electroporation is diffusion of membrane proteins away from the membrane region of contact with the electrode to allow closer contact, increasing the lateral potential field and thus facilitating electroporation.
Collapse
Affiliation(s)
- Xianchan Li
- Department of Chemistry and Molecular Biology, University of Gothenburg , Kemivägen 10, 41296 Gothenburg, Sweden
| | - Johan Dunevall
- Department of Chemical and Chemical Engineering, Chalmers University of Technology , Kemivägen 10, 41296 Gothenburg, Sweden
| | - Lin Ren
- Department of Chemical and Chemical Engineering, Chalmers University of Technology , Kemivägen 10, 41296 Gothenburg, Sweden
| | - Andrew G Ewing
- Department of Chemistry and Molecular Biology, University of Gothenburg , Kemivägen 10, 41296 Gothenburg, Sweden.,Department of Chemical and Chemical Engineering, Chalmers University of Technology , Kemivägen 10, 41296 Gothenburg, Sweden
| |
Collapse
|
21
|
Majdi S, Najafinobar N, Dunevall J, Lovric J, Ewing AG. DMSO Chemically Alters Cell Membranes to Slow Exocytosis and Increase the Fraction of Partial Transmitter Released. Chembiochem 2017; 18:1898-1902. [PMID: 28834067 DOI: 10.1002/cbic.201700410] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Indexed: 01/08/2023]
Abstract
Dimethyl sulfoxide (DMSO) is frequently used as a solvent in biological studies and as a vehicle for drug therapy; but the side effects of DMSO, especially on the cell environment, are not well understood, and controls with DMSO are not neutral at higher concentrations. Herein, electrochemical measurement techniques are applied to show that DMSO increases exocytotic neurotransmitter release, while leaving vesicular contents unchanged. In addition, the kinetics of release from DMSO-treated cells are faster than that of untreated ones. The results suggest that DMSO has a significant influence on the chemistry of the cell membrane, leading to alteration of exocytosis. A speculative chemical mechanism of the effect on the fusion pore during exocytosis is presented.
Collapse
Affiliation(s)
- Soodabeh Majdi
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemivägen 10, 41296, Gothenburg, Sweden
| | - Neda Najafinobar
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Kemivägen 10, 41296, Gothenburg, Sweden
| | - Johan Dunevall
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Kemivägen 10, 41296, Gothenburg, Sweden
| | - Jelena Lovric
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Kemivägen 10, 41296, Gothenburg, Sweden
| | - Andrew G Ewing
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemivägen 10, 41296, Gothenburg, Sweden.,Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Kemivägen 10, 41296, Gothenburg, Sweden
| |
Collapse
|
22
|
Eich ML, Dembla E, Wahl S, Dembla M, Schwarz K, Schmitz F. The Calcineurin-Binding, Activity-Dependent Splice Variant Dynamin1xb Is Highly Enriched in Synapses in Various Regions of the Central Nervous System. Front Mol Neurosci 2017; 10:230. [PMID: 28790889 PMCID: PMC5524891 DOI: 10.3389/fnmol.2017.00230] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2017] [Accepted: 07/06/2017] [Indexed: 12/22/2022] Open
Abstract
In the present study, we generated and characterized a splice site-specific monoclonal antibody that selectively detects the calcineurin-binding dynamin1 splice variant dynamin1xb. Calcineurin is a Ca2+-regulated phosphatase that enhances dynamin1 activity and is an important Ca2+-sensing mediator of homeostatic synaptic plasticity in neurons. Using this dynamin1xb-specific antibody, we found dynamin1xb highly enriched in synapses of all analyzed brain regions. In photoreceptor ribbon synapses, dynamin1xb was enriched in close vicinity to the synaptic ribbon in a manner indicative of a peri-active zone immunolabeling. Interestingly, in dark-adapted mice we observed an enhanced and selective enrichment of dynamin1xb in both synaptic layers of the retina in comparison to light-adapted mice. This could be due to an illumination-dependent recruitment of dynamin1xb to retinal synapses and/or due to a darkness-induced increase of dynamin1xb biosynthesis. These latter findings indicate that dynamin1xb is part of a versatile and highly adjustable, activity-regulated endocytic synaptic machinery.
Collapse
Affiliation(s)
- Marie-Lisa Eich
- Department of Neuroanatomy, Medical School Homburg/Saar, Institute for Anatomy and Cell Biology, Saarland UniversityHomburg/Saar, Germany
| | - Ekta Dembla
- Department of Neuroanatomy, Medical School Homburg/Saar, Institute for Anatomy and Cell Biology, Saarland UniversityHomburg/Saar, Germany
| | - Silke Wahl
- Department of Neuroanatomy, Medical School Homburg/Saar, Institute for Anatomy and Cell Biology, Saarland UniversityHomburg/Saar, Germany
| | - Mayur Dembla
- Department of Neuroanatomy, Medical School Homburg/Saar, Institute for Anatomy and Cell Biology, Saarland UniversityHomburg/Saar, Germany
| | - Karin Schwarz
- Department of Neuroanatomy, Medical School Homburg/Saar, Institute for Anatomy and Cell Biology, Saarland UniversityHomburg/Saar, Germany
| | - Frank Schmitz
- Department of Neuroanatomy, Medical School Homburg/Saar, Institute for Anatomy and Cell Biology, Saarland UniversityHomburg/Saar, Germany
| |
Collapse
|
23
|
Lasič E, Stenovec M, Kreft M, Robinson PJ, Zorec R. Dynamin regulates the fusion pore of endo- and exocytotic vesicles as revealed by membrane capacitance measurements. Biochim Biophys Acta Gen Subj 2017; 1861:2293-2303. [PMID: 28669852 DOI: 10.1016/j.bbagen.2017.06.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/24/2017] [Accepted: 06/27/2017] [Indexed: 02/06/2023]
Abstract
BACKGROUND Dynamin is a multidomain GTPase exhibiting mechanochemical and catalytic properties involved in vesicle scission from the plasmalemma during endocytosis. New evidence indicates that dynamin is also involved in exocytotic release of catecholamines, suggesting the existence of a dynamin-regulated structure that couples endo- to exocytosis. METHODS Thus we here employed high-resolution cell-attached capacitance measurements and super-resolution structured illumination microscopy to directly examine single vesicle interactions with the plasmalemma in cultured rat astrocytes treated with distinct pharmacological modulators of dynamin activity. Fluorescent dextrans and the lipophilic plasmalemmal marker DiD were utilized to monitor uptake and distribution of vesicles in the peri-plasmalemmal space and in the cell cytosol. RESULTS Dynamin inhibition with Dynole™-34-2 and Dyngo™-4a prevented vesicle internalization into the cytosol and decreased fusion pore conductance of vesicles that remained attached to the plasmalemma via a narrow fusion pore that lapsed into a state of repetitive opening and closing - flickering. In contrast, the dynamin activator Ryngo™-1-23 promoted vesicle internalization and favored fusion pore closure by prolonging closed and shortening open fusion pore dwell times. Immunocytochemical staining revealed dextran uptake into dynamin-positive vesicles and increased dextran uptake into Syt4- and VAMP2-positive vesicles after dynamin inhibition, indicating prolonged retention of these vesicles at the plasmalemma. CONCLUSIONS Our results have provided direct evidence for a role of dynamin in regulation of fusion pore geometry and kinetics of endo- and exocytotic vesicles, indicating that both share a common dynamin-regulated structural intermediate, the fusion pore.
Collapse
Affiliation(s)
- Eva Lasič
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia
| | - Matjaž Stenovec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia; Celica Biomedical, Tehnološki Park 24, 1000 Ljubljana, Slovenia.
| | - Marko Kreft
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia; Celica Biomedical, Tehnološki Park 24, 1000 Ljubljana, Slovenia; University of Ljubljana, Biotechnical Faculty, Department of Biology, CPAE, Večna pot 111, 1000 Ljubljana, Slovenia
| | - Phillip J Robinson
- Children's Medical Research Institute, The University of Sydney, Australia
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia; Celica Biomedical, Tehnološki Park 24, 1000 Ljubljana, Slovenia.
| |
Collapse
|
24
|
Papadopulos A. Membrane shaping by actin and myosin during regulated exocytosis. Mol Cell Neurosci 2017; 84:93-99. [PMID: 28536001 DOI: 10.1016/j.mcn.2017.05.006] [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: 01/09/2017] [Revised: 04/21/2017] [Accepted: 05/19/2017] [Indexed: 12/01/2022] Open
Abstract
The cortical actin network in neurosecretory cells is a dense mesh of actin filaments underlying the plasma membrane. Interaction of actomyosin with vesicular membranes or the plasma membrane is vital for tethering, retention, transport as well as fusion and fission of exo- and endocytic membrane structures. During regulated exocytosis the cortical actin network undergoes dramatic changes in morphology to accommodate vesicle docking, fusion and replenishment. Most of these processes involve plasma membrane Phosphoinositides (PIP) and investigating the interactions between the actin cortex and secretory structures has become a hotbed for research in recent years. Actin remodelling leads to filopodia outgrowth and the creation of new fusion sites in neurosecretory cells and actin, myosin and dynamin actively shape and maintain the fusion pore of secretory vesicles. Changes in viscoelastic properties of the actin cortex can facilitate vesicular transport and lead to docking and priming of vesicle at the plasma membrane. Small GTPase actin mediators control the state of the cortical actin network and influence vesicular access to their docking and fusion sites. These changes potentially affect membrane properties such as tension and fluidity as well as the mobility of embedded proteins and could influence the processes leading to both exo- and endocytosis. Here we discuss the multitudes of actin and membrane interactions that control successive steps underpinning regulated exocytosis.
Collapse
Affiliation(s)
- Andreas Papadopulos
- The Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia.
| |
Collapse
|
25
|
Chang CW, Chiang CW, Jackson MB. Fusion pores and their control of neurotransmitter and hormone release. J Gen Physiol 2017; 149:301-322. [PMID: 28167663 PMCID: PMC5339513 DOI: 10.1085/jgp.201611724] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Revised: 01/06/2017] [Accepted: 01/19/2017] [Indexed: 11/20/2022] Open
Abstract
Chang et al. review fusion pore structure and dynamics and discuss the implications for hormone and neurotransmitter release Ca2+-triggered exocytosis functions broadly in the secretion of chemical signals, enabling neurons to release neurotransmitters and endocrine cells to release hormones. The biological demands on this process can vary enormously. Although synapses often release neurotransmitter in a small fraction of a millisecond, hormone release can be orders of magnitude slower. Vesicles usually contain multiple signaling molecules that can be released selectively and conditionally. Cells are able to control the speed, concentration profile, and content selectivity of release by tuning and tailoring exocytosis to meet different biological demands. Much of this regulation depends on the fusion pore—the aqueous pathway by which molecules leave a vesicle and move out into the surrounding extracellular space. Studies of fusion pores have illuminated how cells regulate secretion. Furthermore, the formation and growth of fusion pores serve as a readout for the progress of exocytosis, thus revealing key kinetic stages that provide clues about the underlying mechanisms. Herein, we review the structure, composition, and dynamics of fusion pores and discuss the implications for molecular mechanisms as well as for the cellular regulation of neurotransmitter and hormone release.
Collapse
Affiliation(s)
- Che-Wei Chang
- Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705
| | - Chung-Wei Chiang
- Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705
| | - Meyer B Jackson
- Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705
| |
Collapse
|
26
|
Ganesana M, Lee ST, Wang Y, Venton BJ. Analytical Techniques in Neuroscience: Recent Advances in Imaging, Separation, and Electrochemical Methods. Anal Chem 2017; 89:314-341. [PMID: 28105819 PMCID: PMC5260807 DOI: 10.1021/acs.analchem.6b04278] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
| | | | | | - B. Jill Venton
- Department of Chemistry, PO Box 400319, University of Virginia, Charlottesville, VA 22904
| |
Collapse
|
27
|
Trouillon R, Letizia MC, Menzies KJ, Mouchiroud L, Auwerx J, Schoonjans K, Gijs MAM. A multiscale study of the role of dynamin in the regulation of glucose uptake. Integr Biol (Camb) 2017; 9:810-819. [DOI: 10.1039/c7ib00015d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Cells- and organisms-on-a-chip strategies were used to highlight the role of the molecular motor dynamin in regulating the translocation of specific glucose transporters.
Collapse
Affiliation(s)
- Raphaël Trouillon
- Laboratory of Microsystems
- Ecole Polytechnique Fédérale de Lausanne
- EPFL-STI-IMT-LMIS2
- CH-1015 Lausanne
- Switzerland
| | - M. Cristina Letizia
- Laboratory of Microsystems
- Ecole Polytechnique Fédérale de Lausanne
- EPFL-STI-IMT-LMIS2
- CH-1015 Lausanne
- Switzerland
| | - Keir J. Menzies
- Laboratory of Metabolic Signaling
- Ecole Polytechnique Fédérale de Lausanne
- EPFL-SV-IBI-UPSCHOONJANS
- CH-1015 Lausanne
- Switzerland
| | - Laurent Mouchiroud
- Laboratory of Integrative and Systems Physiology
- Ecole Polytechnique Fédérale de Lausanne
- EPFL-SV-IBI-LISP
- CH-1015 Lausanne
- Switzerland
| | - Johan Auwerx
- Laboratory of Integrative and Systems Physiology
- Ecole Polytechnique Fédérale de Lausanne
- EPFL-SV-IBI-LISP
- CH-1015 Lausanne
- Switzerland
| | - Kristina Schoonjans
- Laboratory of Metabolic Signaling
- Ecole Polytechnique Fédérale de Lausanne
- EPFL-SV-IBI-UPSCHOONJANS
- CH-1015 Lausanne
- Switzerland
| | - Martin A. M. Gijs
- Laboratory of Microsystems
- Ecole Polytechnique Fédérale de Lausanne
- EPFL-STI-IMT-LMIS2
- CH-1015 Lausanne
- Switzerland
| |
Collapse
|
28
|
Oleinick A, Svir I, Amatore C. 'Full fusion' is not ineluctable during vesicular exocytosis of neurotransmitters by endocrine cells. Proc Math Phys Eng Sci 2017; 473:20160684. [PMID: 28265193 PMCID: PMC5312129 DOI: 10.1098/rspa.2016.0684] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 11/17/2016] [Indexed: 11/12/2022] Open
Abstract
Vesicular exocytosis is an essential and ubiquitous process in neurons and endocrine cells by which neurotransmitters are released in synaptic clefts or extracellular fluids. It involves the fusion of a vesicle loaded with chemical messengers with the cell membrane through a nanometric fusion pore. In endocrine cells, unless it closes after some flickering ('Kiss-and-Run' events), this initial pore is supposed to expand exponentially, leading to a full integration of the vesicle membrane into the cell membrane-a stage called 'full fusion'. We report here a compact analytical formulation that allows precise measurements of the fusion pore expansion extent and rate to be extracted from individual amperometric spike time courses. These data definitively establish that, during release of catecholamines, fusion pores enlarge at most to approximately one-fifth of the radius of their parent vesicle, hence ruling out the ineluctability of 'full fusion'.
Collapse
Affiliation(s)
| | | | - Christian Amatore
- Ecole Normale Supérieure-PSL Research University, Département de Chimie, Sorbonne Universités-UPMC Paris 06, CNRS UMR 8640 PASTEUR, 24 rue Lhomond, 75005 Paris, France
| |
Collapse
|
29
|
Single cell amperometry reveals curcuminoids modulate the release of neurotransmitters during exocytosis from PC12 cells. J Electroanal Chem (Lausanne) 2016; 781:30-35. [PMID: 28579928 DOI: 10.1016/j.jelechem.2016.10.025] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We used single cell amperometry to examine whether curcumin and bisdemethoxycurcumin (BDMC), substances that are suggested to affect learning and memory, can modulate monoamine release from PC12 cells. Our results indicate both curcumin and BDMC need long-term treatment (72 h in this study) to influence exocytosis effectively. By analyzing the parameters calculated from single exocytosis events, it can be concluded that curcumin and BDMC affect exocytosis through different mechanisms. Curcumin accelerates the event dynamics with no significant change of the monoamine amount released from single exocytotic events, whereas BDMC attenuates the amount from single exocytotic event with no significant change of the event dynamics. This comparison of the effect of curcumin and BDMC on exocytosis at the single cell level brings insight into their different mechanisms, which might lead to different biological actions. The effect of curcumin and BDMC on the opening and closing of the exocytotic fusion pore were also investigated. These results might be helpful for understanding the improvement of learning and memory and the anti-depression properties of curcuminoids.
Collapse
|
30
|
Abstract
Exocytosis is the fundamental process by which cells communicate with each other. The events that lead up to the fusion of a vesicle loaded with chemical messenger with the cell membrane were the subject of a Nobel Prize in 2013. However, the processes occurring after the initial formation of a fusion pore are very much still in debate. The release of chemical messenger has traditionally been thought to occur through full distention of the vesicle membrane, hence assuming exocytosis to be all or none. In contrast to the all or none hypothesis, here we discuss the evidence that during exocytosis the vesicle-membrane pore opens to release only a portion of the transmitter content during exocytosis and then close again. This open and closed exocytosis is distinct from kiss-and-run exocytosis, in that it appears to be the main content released during regular exocytosis. The evidence for this partial release via open and closed exocytosis is presented considering primarily the quantitative evidence obtained with amperometry.
Collapse
|
31
|
Li X, Dunevall J, Ewing AG. Using Single-Cell Amperometry To Reveal How Cisplatin Treatment Modulates the Release of Catecholamine Transmitters during Exocytosis. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201602977] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Xianchan Li
- Department of Chemistry and Molecular Biology; University of Gothenburg; Kemivägen 10 41296 Gothenburg Sweden
| | - Johan Dunevall
- Department of Chemistry and Chemical Engineering; Chalmers University of Technology; Kemivägen 10 41296 Gothenburg Sweden
| | - Andrew G. Ewing
- Department of Chemistry and Molecular Biology; University of Gothenburg; Kemivägen 10 41296 Gothenburg Sweden
- Department of Chemistry and Chemical Engineering; Chalmers University of Technology; Kemivägen 10 41296 Gothenburg Sweden
| |
Collapse
|
32
|
Li X, Dunevall J, Ewing AG. Using Single-Cell Amperometry To Reveal How Cisplatin Treatment Modulates the Release of Catecholamine Transmitters during Exocytosis. Angew Chem Int Ed Engl 2016; 55:9041-4. [PMID: 27239950 DOI: 10.1002/anie.201602977] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Indexed: 11/08/2022]
Abstract
The pretreatment of cultured pheochromocytoma (PC12) cells with cis-diamminedichloroplatinum (cisplatin), an anti-cancer drug, influences the exocytotic ability of the cells in a dose-dependent manner. Low concentrations of cisplatin stimulate catecholamine release whereas high concentrations inhibit it. Single-cell amperometry reflects that 2 μm cisplatin treatment increases the frequency of exocytotic events and reduces their duration, whereas 100 μm cisplatin treatment decreases the frequency of exocytotic events and increases their duration. Furthermore, the stability of the initial fusion pore that is formed in the lipid membrane during exocytosis is also regulated differentially by different cisplatin concentrations. This study thus suggests that cisplatin influences exocytosis by multiple mechanisms.
Collapse
Affiliation(s)
- Xianchan Li
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemivägen 10, 41296, Gothenburg, Sweden
| | - Johan Dunevall
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Kemivägen 10, 41296, Gothenburg, Sweden
| | - Andrew G Ewing
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemivägen 10, 41296, Gothenburg, Sweden. , .,Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Kemivägen 10, 41296, Gothenburg, Sweden. ,
| |
Collapse
|
33
|
Trouillon R, Gijs MAM. Dynamic electrochemical quantitation of dopamine release from a cells-on-paper system. RSC Adv 2016. [DOI: 10.1039/c6ra02487d] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
A simple hybrid microfluidic/electrochemical system is used to observe the secretion of neurotransmitters from a cells-on-paper system.
Collapse
Affiliation(s)
- Raphaël Trouillon
- Laboratory of Microsystems
- Ecole Polytechnique Fédérale de Lausanne
- CH-1015 Lausanne
- Switzerland
| | - Martin A. M. Gijs
- Laboratory of Microsystems
- Ecole Polytechnique Fédérale de Lausanne
- CH-1015 Lausanne
- Switzerland
| |
Collapse
|
34
|
Jackson J, Papadopulos A, Meunier FA, McCluskey A, Robinson PJ, Keating DJ. Small molecules demonstrate the role of dynamin as a bi-directional regulator of the exocytosis fusion pore and vesicle release. Mol Psychiatry 2015; 20:810-9. [PMID: 25939402 DOI: 10.1038/mp.2015.56] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 03/14/2015] [Accepted: 03/24/2015] [Indexed: 12/18/2022]
Abstract
Hormones and neurotransmitters are stored in specialised vesicles and released from excitable cells through exocytosis. During vesicle fusion with the plasma membrane, a transient fusion pore is created that enables transmitter release. The protein dynamin is known to regulate fusion pore expansion (FPE). The mechanism is unknown, but requires its oligomerisation-stimulated GTPase activity. We used a palette of small molecule dynamin modulators to reveal bi-directional regulation of FPE by dynamin and vesicle release in chromaffin cells. The dynamin inhibitors Dynole 34-2 and Dyngo 4a and the dynamin activator Ryngo 1-23 reduced or increased catecholamine released from single vesicles, respectively. Total internal reflection fluorescence (TIRF) microscopy demonstrated that dynamin stimulation with Ryngo 1-23 reduced the number of neuropeptide Y (NPY) kiss-and-run events, but not full fusion events, and slowed full fusion release kinetics. Amperometric stand-alone foot signals, representing transient kiss-and-run events, were less frequent but were of longer duration, similarly to full amperometric spikes and pre-spike foot signals. These effects are not due to alterations in vesicle size. Ryngo 1-23 action was blocked by inhibitors of actin polymerisation or myosin II. Therefore, we demonstrate using a novel pharmacological approach that dynamin not only controls FPE during exocytosis, but is a bi-directional modulator of the fusion pore that increases or decreases the amount released from a vesicle during exocytosis if it is activated or inhibited, respectively. As such, dynamin has the ability to exquisitely fine-tune transmitter release.
Collapse
Affiliation(s)
- J Jackson
- Discipline of Human Physiology, Centre for Neuroscience, Flinders University, Adelaide, Australia
| | - A Papadopulos
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia
| | - F A Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia
| | - A McCluskey
- Centre for Chemical Biology and Chemistry, School of Environmental and Life Sciences, The University of Newcastle, Callaghan, New South Wales, Australia
| | - P J Robinson
- Children's Medical Research Institute, University of Sydney, Westmead, New South Wales, Australia
| | - D J Keating
- 1] Discipline of Human Physiology, Centre for Neuroscience, Flinders University, Adelaide, Australia [2] South Australian Health and Medical Research Institute (SAHMRI), Adelaide, Australia
| |
Collapse
|
35
|
Read J, Clancy EK, Sarker M, de Antueno R, Langelaan DN, Parmar HB, Shin K, Rainey JK, Duncan R. Reovirus FAST Proteins Drive Pore Formation and Syncytiogenesis Using a Novel Helix-Loop-Helix Fusion-Inducing Lipid Packing Sensor. PLoS Pathog 2015; 11:e1004962. [PMID: 26061049 PMCID: PMC4464655 DOI: 10.1371/journal.ppat.1004962] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Accepted: 05/18/2015] [Indexed: 02/07/2023] Open
Abstract
Pore formation is the most energy-demanding step during virus-induced membrane fusion, where high curvature of the fusion pore rim increases the spacing between lipid headgroups, exposing the hydrophobic interior of the membrane to water. How protein fusogens breach this thermodynamic barrier to pore formation is unclear. We identified a novel fusion-inducing lipid packing sensor (FLiPS) in the cytosolic endodomain of the baboon reovirus p15 fusion-associated small transmembrane (FAST) protein that is essential for pore formation during cell-cell fusion and syncytiogenesis. NMR spectroscopy and mutational studies indicate the dependence of this FLiPS on a hydrophobic helix-loop-helix structure. Biochemical and biophysical assays reveal the p15 FLiPS preferentially partitions into membranes with high positive curvature, and this partitioning is impeded by bis-ANS, a small molecule that inserts into hydrophobic defects in membranes. Most notably, the p15 FLiPS can be functionally replaced by heterologous amphipathic lipid packing sensors (ALPS) but not by other membrane-interactive amphipathic helices. Furthermore, a previously unrecognized amphipathic helix in the cytosolic domain of the reptilian reovirus p14 FAST protein can functionally replace the p15 FLiPS, and is itself replaceable by a heterologous ALPS motif. Anchored near the cytoplasmic leaflet by the FAST protein transmembrane domain, the FLiPS is perfectly positioned to insert into hydrophobic defects that begin to appear in the highly curved rim of nascent fusion pores, thereby lowering the energy barrier to stable pore formation. The fusogenic ortho- and aquareoviruses are the only known nonenveloped viruses that induce syncytium formation. Cell-cell fusion is a virulence determinant of fusogenic reoviruses, and is mediated by a singular family of fusion-associated small transmembrane (FAST) proteins, the smallest known viral fusogens. Unlike their enveloped virus counterparts, reovirus FAST proteins have exceptionally small ectodomains and considerable larger cytoplasmic endodomains, suggesting FAST protein interactions with the cytoplasmic leaflet of the plasma membrane likely play a prominent role in the fusion process. We determined that the baboon reovirus p15 FAST protein endodomain contains a novel type of helix-loop-helix lipid packing sensor that partitions into hydrophobic defects present in highly curved membranes. This fusion-inducing lipid packing sensor (FLiPS) is required for pore formation, and can be functionally replaced by heterologous lipid packing sensors. By masking hydrophobic defects appearing in the highly curved rim of nascent fusion pores, the FliPS would make the forward reaction to pore formation a more energetically favored means of resolving an unstable hemifusion intermediate. These results define a new role for curvature sensing motifs, and reveal how viral fusion proteins can drive pore formation without having to rely on membrane stresses induced by complex refolding of large ectodomains.
Collapse
Affiliation(s)
- Jolene Read
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Eileen K. Clancy
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Muzaddid Sarker
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Roberto de Antueno
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - David N. Langelaan
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Hiren B. Parmar
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Kyungsoo Shin
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jan K. Rainey
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Roy Duncan
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Pediatrics, Dalhousie University, Halifax, Nova Scotia, Canada
- * E-mail:
| |
Collapse
|
36
|
Trouillon R, Gijs MA. Interplay between the potential waveform and diffusion layer dynamics determines the time-response of voltammetric detection in microchannels. Electrochim Acta 2015. [DOI: 10.1016/j.electacta.2015.02.165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
37
|
Pittsburgh Analytical Chemistry Award: A. G. Ewing / Charles N. Reilley Award: H. H. Girault / Alwin-Mittasch-Preis: R. Schlögl / Jochen-Block-Preis: M. Cokoja. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201502709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
38
|
Pittsburgh Analytical Chemistry Award: A. G. Ewing / Charles N. Reilley Award: H. H. Girault / Alwin Mittasch Prize: R. Schlögl / Jochen Block Prize: M. Cokoja. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/anie.201502709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
39
|
Wong MY, Cavolo SL, Levitan ES. Synaptic neuropeptide release by dynamin-dependent partial release from circulating vesicles. Mol Biol Cell 2015; 26:2466-74. [PMID: 25904335 PMCID: PMC4571301 DOI: 10.1091/mbc.e15-01-0002] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 04/17/2015] [Indexed: 12/13/2022] Open
Abstract
Neurons release neuropeptides, enzymes, and neurotrophins by exocytosis of dense-core vesicles (DCVs). Peptide release from individual DCVs has been imaged in vitro with endocrine cells and at the neuron soma, growth cones, neurites, axons, and dendrites but not at nerve terminals, where peptidergic neurotransmission occurs. Single presynaptic DCVs have, however, been tracked in native terminals with simultaneous photobleaching and imaging (SPAIM) to show that DCVs undergo anterograde and retrograde capture as they circulate through en passant boutons. Here dynamin (encoded by the shibire gene) is shown to enhance activity-evoked peptide release at the Drosophila neuromuscular junction. SPAIM demonstrates that activity depletes only a portion of a single presynaptic DCV's content. Activity initiates exocytosis within seconds, but subsequent release occurs slowly. Synaptic neuropeptide release is further sustained by DCVs undergoing multiple rounds of exocytosis. Synaptic neuropeptide release is surprisingly similar regardless of anterograde or retrograde DCV transport into boutons, bouton location, and time of arrival in the terminal. Thus vesicle circulation and bidirectional capture supply synapses with functionally competent DCVs. These results show that activity-evoked synaptic neuropeptide release is independent of a DCV's past traffic and occurs by slow, dynamin-dependent partial emptying of DCVs, suggestive of kiss-and-run exocytosis.
Collapse
Affiliation(s)
- Man Yan Wong
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
| | - Samantha L Cavolo
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
| | - Edwin S Levitan
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
| |
Collapse
|
40
|
Lemaître F, Guille Collignon M, Amatore C. Recent advances in Electrochemical Detection of Exocytosis. Electrochim Acta 2014. [DOI: 10.1016/j.electacta.2014.02.059] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
|
41
|
Trouillon R, Ewing AG. Actin controls the vesicular fraction of dopamine released during extended kiss and run exocytosis. ACS Chem Biol 2014; 9:812-20. [PMID: 24400601 PMCID: PMC3985473 DOI: 10.1021/cb400665f] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
![]()
The effect of latrunculin A, an inhibitor
of actin cross-linking,
on exocytosis in PC12 cells was investigated with single cell amperometry.
This analysis strongly suggests that the actin cytoskeleton might
be involved in regulating exocytosis, especially by mediating the
constriction of the pore. In an extended kiss-and-run release mode,
actin could actually control the fraction of neurotransmitters released
by the vesicle. This scaffold appears to contribute, with the lipid
membrane and the protein machinery, to the closing dynamics of the
pore, in competition with other forces mediating the opening of the
exocytotic channel.
Collapse
Affiliation(s)
- Raphaël Trouillon
- Department
of Chemistry and Molecular Biology, University of Gothenburg, S-41296 Gothenburg, Sweden
| | - Andrew G. Ewing
- Department
of Chemistry and Molecular Biology, University of Gothenburg, S-41296 Gothenburg, Sweden
- Department
of Chemical and Biological Engineering, Chalmers University of Technology, S-41296 Gothenburg, Sweden
| |
Collapse
|
42
|
Kulkarni A, Alpadi K, Sirupangi T, Peters C. A dynamin homolog promotes the transition from hemifusion to content mixing in intracellular membrane fusion. Traffic 2014; 15:558-71. [PMID: 24471450 DOI: 10.1111/tra.12156] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 01/24/2014] [Accepted: 01/28/2014] [Indexed: 01/02/2023]
Abstract
The convergence of the antagonistic reactions of membrane fusion and fission at the hemifusion/hemifission intermediate has generated a captivating enigma of whether Soluble N-ethylmaleimide sensitive factor Attachment Protein Receptor (SNAREs) and dynamin have unusual counter-functions in fission and fusion, respectively. SNARE-mediated fusion and dynamin-driven fission are fundamental membrane flux reactions known to occur during ubiquitous cellular communication events such as exocytosis, endocytosis and vesicle transport. Here we demonstrate the influence of the dynamin homolog Vps1 (Vacuolar protein sorting 1) on lipid mixing and content mixing properties of yeast vacuoles, and on the incorporation of SNAREs into fusogenic complexes. We propose a novel concept that Vps1, through its oligomerization and SNARE domain binding, promotes the hemifusion-content mixing transition in yeast vacuole fusion by increasing the number of trans-SNAREs.
Collapse
Affiliation(s)
- Aditya Kulkarni
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | | | | | | |
Collapse
|
43
|
Samasilp P, Lopin K, Chan SA, Ramachandran R, Smith C. Syndapin 3 modulates fusion pore expansion in mouse neuroendocrine chromaffin cells. Am J Physiol Cell Physiol 2014; 306:C831-43. [PMID: 24500282 DOI: 10.1152/ajpcell.00291.2013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Adrenal neuroendocrine chromaffin cells receive excitatory synaptic input from the sympathetic nervous system and secrete hormones into the peripheral circulation. Under basal sympathetic tone, modest amounts of freely soluble catecholamine are selectively released through a restricted fusion pore formed between the secretory granule and the plasma membrane. Upon activation of the sympathoadrenal stress reflex, elevated stimulation drives fusion pore expansion, resulting in increased catecholamine secretion and facilitating release of copackaged peptide hormones. Thus regulated expansion of the secretory fusion pore is a control point for differential hormone release of the sympathoadrenal stress response. Previous work has shown that syndapin 1 deletion alters transmitter release and that the dynamin 1-syndapin 1 interaction is necessary for coupled endocytosis in neurons. Dynamin has also been shown to be involved in regulation of fusion pore expansion in neuroendocrine chromaffin cells through an activity-dependent association with syndapin. However, it is not known which syndapin isoform(s) contributes to pore dynamics in neuroendocrine cells. Nor is it known at what stage of the secretion process dynamin and syndapin associate to modulate pore expansion. Here we investigate the expression and localization of syndapin isoforms and determine which are involved in mediating fusion pore expansion. We show that all syndapin isoforms are expressed in the adrenal medulla. Mutation of the SH3 dynamin-binding domain of all syndapin isoforms shows that fusion pore expansion and catecholamine release are limited specifically by mutation of syndapin 3. The mutation also disrupts targeting of syndapin 3 to the cell periphery. Syndapin 3 exists in a persistent colocalized state with dynamin 1.
Collapse
Affiliation(s)
- Prattana Samasilp
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio; and
| | | | | | | | | |
Collapse
|