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> Physiology > Cell Function > Exocytosis

Exocytosis

Exocytosis is the process by which membrane-bound vesicles containing proteins, hormones, neurotransmitters, and other substances are released from the cell by fusing with the plasma membrane.
This fundamental cellular process is essential for a wide range of physiological functions, including neurotransmitter release, hormone secretion, and immune response.
Exocytosis involves the regulated movement and fusion of vesicles with the cell membrane, enabling the extracellular release of the vesicle contents.
Defects in exocytosis have been implicated in various diseases, making it an important area of biomedical research.
Optimizing exocytosis research through reliable protocol identification and comparison can enhance reproducibility and accuracy, leading to advancements in our understanding and treatment of related disorders.

Most cited protocols related to «Exocytosis»

1
Modeling Particle-Cell Interactions
In standard liquid-based cell culture systems, the amount of particles associated with cells at any time is a function of the rate of delivery of particles to the cells, how strongly particles adhere to the cell surface, and the rates of cellular uptake and loss by degradation or exocytosis.
ISDD applies well established, long-used principles of diffusional and gravitational transport of particles in viscous media to calculate the movement of particles from the media to the bottom of a vessel where cells reside. The net rate of transport downward toward the bottom of the vessel is calculated within a single partial differential equation, which is solved numerically to calculate the fraction of material transported from media to the bottom of the vessel. Simulations are conducted using commonly available inputs for monodisperse particles: temperature, media density and viscosity, media height, hydrodynamic particle size in the test media, and particle density. Simulations of agglomerates also require two additional parameters describing how the primary particles are packed to form the agglomerate. The model produces a time-course of particle surface area, number and mass transported to the bottom of the vessel, referred to as the delivered dose, which can be compared to measured values in a cell free environment. The delivered dose can also be compared to measured amounts associated with cells (in or adhered to), which is an appropriate, but possibly less certain comparison because the roles of cellular uptake, adherence, and loss of adhered material during washing are not accounted for explicitly in the current formulation of ISDD. ISDD focuses on particle transport because this process can be rate limiting, is very valuable for the experimentalist to understand, can be simulated with a relatively small set of easy to access parameters, and is independent of cell type and other experimental conditions that affect cellular uptake. Moreover, at this time, it is experimentally difficult to separate particle uptake (particles in a cell) from cell associated particles (on a cell or in a cell). If necessary, modifications to the boundary conditions or assumptions regarding fractional uptake can be used to account for cellular uptake. Thus, ISDD calculates the delivered dose, which is equivalent to particles associated with the cell (on a cell or in a cell), the only commonly available experimental measure of target cell dose.
Hinderliter P.M., Minard K.R., Orr G., Chrisler W.B., Thrall B.D., Pounds J.G, & Teeguarden J.G. (2010). ISDD: A computational model of particle sedimentation, diffusion and target cell dosimetry for in vitro toxicity studies. Particle and Fibre Toxicology, 7, 36.
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Publication 2010
Blood Vessel Cell Culture Techniques Diffusion Exocytosis Gravitation Hydrodynamics Movement Obstetric Delivery Tunica Media Viscosity
2
Astrocyte Calcium Signaling in Hippocampal LTP
Whole-cell recordings from passive astrocytes (n = 146) were made in stratum radiatum, area CA1 in acute transverse hippocampal slices prepared from adult rats. Cells (30-100 μm deep inside the slice) were loaded with a bright morphological tracer Alexa Fluor 594 and the high-affinity Ca2+ indicator Oregon Green BAPTA (OGB-1) and imaged in two-photon excitation mode (λ2px = 800 nm). Field EPSPs were recorded using either an extracellular recording electrode placed in the immediate vicinity of the visualised astrocyte dendritic arbour or through the astrocytic patch pipette, as described. Whole-cell EPSCs were recorded from CA1 pyramidal cells. Electric stimuli were applied to Schaffer collateral fibres. LTP was induced by a standard high-frequency stimulation protocol (three 100-pulse trains at 100 Hz, 60 or 20 seconds apart). Inside the recorded astrocyte, conditions of Ca2+ homeostasis were altered using intracellular solutions containing EGTA, Oregon Green BAPTA-1, and CaCl2; the exocytosis machinery was suppressed using light-chain tetanus toxin; synthesis of D-serine was inhibited with serine racemase inhibitor L-erythro-3-hydroxyaspartate (HOAsp).
Henneberger C., Papouin T., Oliet S.H, & Rusakov D.A. (2010). Long term potentiation depends on release of D-serine from astrocytes. Nature, 463(7278), 232-236.
Publication 2009
1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid Adult Alexa594 Anabolism Astrocytes Cells Conditioning, Psychology Dendrites Egtazic Acid Electricity Excitatory Postsynaptic Potentials Exocytosis Fibrosis Homeostasis Light Neoplasm Metastasis Protoplasm Pulse Rate Pyramidal Cells Rattus norvegicus Schaffer Collaterals Serine SRR protein, human Toxin, Tetanus
3
Astrocyte Calcium Signaling in Hippocampal LTP
Whole-cell recordings from passive astrocytes (n = 146) were made in stratum radiatum, area CA1 in acute transverse hippocampal slices prepared from adult rats. Cells (30-100 μm deep inside the slice) were loaded with a bright morphological tracer Alexa Fluor 594 and the high-affinity Ca2+ indicator Oregon Green BAPTA (OGB-1) and imaged in two-photon excitation mode (λ2px = 800 nm). Field EPSPs were recorded using either an extracellular recording electrode placed in the immediate vicinity of the visualised astrocyte dendritic arbour or through the astrocytic patch pipette, as described. Whole-cell EPSCs were recorded from CA1 pyramidal cells. Electric stimuli were applied to Schaffer collateral fibres. LTP was induced by a standard high-frequency stimulation protocol (three 100-pulse trains at 100 Hz, 60 or 20 seconds apart). Inside the recorded astrocyte, conditions of Ca2+ homeostasis were altered using intracellular solutions containing EGTA, Oregon Green BAPTA-1, and CaCl2; the exocytosis machinery was suppressed using light-chain tetanus toxin; synthesis of D-serine was inhibited with serine racemase inhibitor L-erythro-3-hydroxyaspartate (HOAsp).
Henneberger C., Papouin T., Oliet S.H, & Rusakov D.A. (2010). Long term potentiation depends on release of D-serine from astrocytes. Nature, 463(7278), 232-236.
Publication 2009
1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid Adult Alexa594 Anabolism Astrocytes Cells Conditioning, Psychology Dendrites Egtazic Acid Electricity Excitatory Postsynaptic Potentials Exocytosis Fibrosis Homeostasis Light Neoplasm Metastasis Protoplasm Pulse Rate Pyramidal Cells Rattus norvegicus Schaffer Collaterals Serine SRR protein, human Toxin, Tetanus
4
Influenza Virus Infection of BMDCs
BMDC were generated as described 34 (link). On day 6–7, BMDC were harvested and infected with influenza virus at approximated 100 EIU per cell for 5–6 h. Then BMDC were counted and mixed with total lung, MLN or spleen cells at a 1.5 to 1 ratio in the presence of Golgi-Stop (BD Biosciences, 1 μl ml−1) and hIL-2 (40 U ml−1) for additional 6h. The surface staining of cell surface markers, intracellular staining of cytokines, T-bet and Foxp-3 were performed as described before 35 (link) or according to manufacturer manuals. For the measuring of granule exocytosis by CD107a, fluorescence labeled CD107a-specific mAb or isotype control mAb were added to the in vitro stimulation cultures and the surface accumulation of CD107a was measured by flow cytometry 36 (link).
Sun J., Madan R., Karp C.L, & Braciale T.J. (2009). Effector T cells control lung inflammation during acute influenza virus infection by producing IL-10. Nature medicine, 15(3), 277-284.
Publication 2009
Cytokine Cytoplasmic Granules Exocytosis Flow Cytometry Fluorescence Golgi Apparatus Immunoglobulin Isotypes Lung Orthomyxoviridae Protoplasm Spleen
5
Ultrastructural Analysis of Microglial Function
The analysis of microglial cell bodies and processes comprised several ultrastructural measures of morphology, phagocytic activity, cellular stress, and physiological function. Experimenters were blinded to the experimental conditions throughout the analysis. Size and shape descriptors were determined using ImageJ. For each microglial cell body and process, phagocytic inclusions (appearing electron-lucent and named “empty” versus containing materials and named “non-empty”), lysosomes (primary, secondary, versus tertiary), lipid bodies, fibrillar materials, ER dilation, vacuoles (diameter < 100 nm), and extracellular space pockets containing debris were counted, according to the quantitative code 0, 1, 2, and 3+ (designating 3 and more occurrences). Lysosomes were identified by their dense, heterogeneous contents enclosed by a single membrane [49 (link)]. Primary lysosomes possessed a homogenous granular content and their diameter ranged from 0.3 to 0.5 μm [50 (link)]. Secondary lysosomes were 1 to 2 μm across, and their content was heterogeneous showing fusion with vacuoles. Tertiary lysosomes ranged in diameter between 1.5 and 2.5 μm, and they were usually fused to one or two vacuoles associated with lipofuscin granules, as well as lipidic inclusions showing signs of degradation [51 (link)]. Lipidic inclusions were identified as the clustering of round organelles with an electron dense, either opaque or limpid, cytoplasm enclosed by a single membrane. Lipofuscin granules were identified by their oval or round shapes, finely granular composition, and associated amorphous materials [51 (link)]. Extracellular fAβ was identified as densely packed fibrils and filaments, according to previous ultrastructural descriptions [52 (link)]. ER dilation was recognized by a swelling of the cisternal space ranging from 50 to 300 nm [53 (link)]. Extracellular space pockets containing debris, which could result from “exophagy” (degradation of cellular constituents by lysosomal enzymes released extracellularly), exocytosis (the process of expelling the contents of a membrane-bound vesicle into the extracellular space, often lysosomal and in preparation for phagocytosis; [54 (link)]), or pinocytosis (also named bulk-phase endocytosis, by which cells can take up extracellular contents in a non-phagocytic manner; [55 (link)]) was defined by the appearance of degraded materials (including cellular membranes and organelles) or debris in the extracellular space juxtaposing the microglia [54 (link)].
For microglial processes, their encirclement of neuropil compartments (axon terminals, dendritic spines, synapses between axon terminals and dendritic spines, cellular elements with signs of degradation) was also quantified. Encirclement was defined as microglial interactions with these neuropil compartments that displayed at least two points of contact, sometimes extending over several hundreds of nanometers. They were scored using the quantitative code 0, 1, 2, and 3+ (designating 3 and more elements). The encircled elements were identified according to the following criteria: axon terminals contained synaptic vesicles and were frequently seen branching from axons or making synapses onto dendritic branches and spines, and dendritic spines were identified as extensions from dendrites often forming synapses where a postsynaptic density was observed. Moreover, microglial encirclement of extracellular debris was determined.
El Hajj H., Savage J.C., Bisht K., Parent M., Vallières L., Rivest S, & Tremblay M.È. (2019). Ultrastructural evidence of microglial heterogeneity in Alzheimer’s disease amyloid pathology. Journal of Neuroinflammation, 16, 87.
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Publication 2019
Axon Cells Cellular Structures Cytoplasm Cytoplasmic Granules Cytoskeletal Filaments Dendrites Dendritic Spines Dietary Fiber Dilatation Electrons Endocytosis Enzymes Exocytosis Extracellular Space Genetic Heterogeneity Homozygote Human Body Inclusion Bodies Lipid Droplet Lipofuscin Lysosomes Microglia Neuropil Organelles Phagocytes Phagocytosis Pinocytosis Plasma Membrane Post-Synaptic Density Presynaptic Terminals Synapses Synaptic Vesicles Tissue, Membrane Vacuole Vertebral Column Vision

Most recents protocols related to «Exocytosis»

1
Genetic Models of Rab27 Effector Deficiency
Animal experiments were performed according to the rules and regulations of the Animal Care and Experimental Committees of Gunma University (permit number: 22-010; Maebashi, Japan). Only male mice and their tissues and cells were phenotypically characterized in this study. Leaden (C57J/L) mice with nonfunctional mutation of the gene encoding melanophilin (Mlph) (Matesic et al., 2001 (link)) were purchased from The Jackson Laboratory (Strain #:000668, RRID:IMSR_JAX:000668), and were backcrossed with C57BL/6N mice 10 times to generate MlphKO mice. Exo8KO mice in the genetic background of C57BL/6N mice were described previously (Fan et al., 2017 (link)). ME8DKO mice were obtained by mating Exo8KO mice with the MlphKO mice described above. GrphKO mice in the genetic background of C3H/He mice were described previously (Gomi et al., 2005 (link)). The male Exo8KO mice were mated with the female GrphKO mice. Because the granuphilin and exophilin-8 genes are on the mouse X and 9 chromosomes, respectively, the resultant F1 generation is either male (Grph-/Y, Exo8+/-) or female (Grph+/-, Exo8+/-). By crossing these F1 mice, GE8DKO mice, as well as the WT, GrphKO, and Exo8KO mice, were generated in the F2 generation and used for experiments. Although the resultant F2 mice have a mixture of C57BL/6N and C3H/He genomes, we expected that significant phenotypic changes due to the loss of Rab27 effectors may be preserved despite any influences due to randomly distributed differences in the genome. In fact, we found similar differences in exocytic profiles between WT and Exo8KO cells both in the C57BL/6N background (Figure 2) and in the mixture of the C57BL/6N and C3H/He backgrounds (Figure 6). Furthermore, GrphKO cells in the mixture of the C57BL/6N and C3H/He backgrounds showed changes in granule localization and exocytosis (Figure 6), consistent with the reported phenotypes of GrphKO cells in the C3H/He background (Gomi et al., 2005 (link)). Pancreatic islet isolation and dissociation into monolayer cells and insulin secretion assays were performed as described previously (Gomi et al., 2005 (link); Wang et al., 2020 (link)). Briefly, islets were isolated from cervically dislocated mice by pancreatic duct injection of collagenase solution, and size-matched five islets were cultured overnight in a 24-well plate. Monolayer islet cells were prepared by incubation with trypsin-EDTA solution and were cultured for further 2 days. Insulin released from isolated islets or monolayer cells was measured by an AlphaLISA insulin kit (PerkinElmer) or insulin high range and ultra-sensitive kits (Cisbio).
Zhao K., Matsunaga K., Mizuno K., Wang H., Okunishi K, & Izumi T. (2023). Functional hierarchy among different Rab27 effectors involved in secretory granule exocytosis. eLife, 12, e82821.
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Publication 2023
Animals Biological Assay Cells Chromosomes, Human, Pair 9 Collagenase Cytoplasmic Granules Edetic Acid Exocytosis Females Genes Genetic Background Genome Insulin Insulin Secretion Islets of Langerhans Males Mice, House Mice, Inbred C3H Mice, Inbred C57BL Mus Mutation Pancreatic Duct Phenotype SLAC2-A protein, human Strains Tissues Trypsin
2
Paxillin Colocalization during Exocytosis
The average paxillin fluorescence intensity was measured at the locations of exocytosis event. The significance was accessed using Monte Carlo simulations (see corresponding section). The comparison of the observed average intensity with simulated ones allows classifying cells with a colocalization index (Iobs/Isim) under two categories: co-appearing (Iobs/Isim > 1), no-co-appearing (Iobs/Isim < 1). The separation of central and peripheral FAs subpopulations in S2D has been done according to a threshold distance from cell borders. FAs with a distance superior to 3 µm from cell borders are classified as central, whereas the others are classified as peripheral. Note that we tested different threshold distances and the analysis remained robust and leads to similar conclusions.
Lachuer H., Le L., Lévêque-Fort S., Goud B, & Schauer K. (2023). Spatial organization of lysosomal exocytosis relies on membrane tension gradients. Proceedings of the National Academy of Sciences of the United States of America, 120(8), e2207425120.
Publication 2023
Cells Exocytosis Fluorescence Population Group PXN protein, human
3
Analyzing Exocytosis Patterns with Spatial Statistics
On micropatterns, exocytosis events were described with polar coordinates (with the origin at the center of the pattern). The modulus is the distance between an event and the center (normalized by the cell radius). For each cell a modulus distribution was computed using KDE. To avoid boundary effects, an asymmetric beta kernel was used (89 (link)) using the evmix function dbckden(). The depicted modulus distribution is an average over the population ±SEM. This distribution can be compared to the expected distribution in case of CSR: pCSRr=2r.
The 95% CSR envelope was computed using Monte-Carlo simulations (see corresponding section). Despite beta edge correction, the simulations do not fit perfectly pcsr. In order to avoid any bias due to kernels, we also conducted the same analysis using empirical cumulative distributions. The empirical cumulative distribution PCSR under CSR hypothesis is: PCSRr=∫0rpCSRxdx=r2.
Lachuer H., Le L., Lévêque-Fort S., Goud B, & Schauer K. (2023). Spatial organization of lysosomal exocytosis relies on membrane tension gradients. Proceedings of the National Academy of Sciences of the United States of America, 120(8), e2207425120.
Publication 2023
Cells Exocytosis Radius
4
Anisotropic Exocytosis Event Analysis
The cell was cut in 30 angular sections (from the center of mass). An angle θi was associated to each section. The number of exocytosis event was computed in each section and divided by the surface of the corresponding section giving a coefficient wi (normalized by the sum of the coefficients). The anisotropy/polarization measurement is based on the average resultant length computed as: R=(∑i=130wicos(θi))2+(∑i=130wisin(θi))2.
This polarization index ranged between 0 and 1. The significance was accessed using Monte Carlo simulations (see corresponding section). Observed average resultant lengths were divided by the average simulated resultant length allowing a classification of the cells into two categories: polarized (ratio > 1) or non-polarized (ratio < 1).
Lachuer H., Le L., Lévêque-Fort S., Goud B, & Schauer K. (2023). Spatial organization of lysosomal exocytosis relies on membrane tension gradients. Proceedings of the National Academy of Sciences of the United States of America, 120(8), e2207425120.
Publication 2023
Anisotropy Cells Exocytosis
5
Nearest Neighbor Distance Analysis
The NND of a given exocytosis event is the distance to the closest exocytosis event. These distances give information on the short scale spatial structure. NND was used to test CSR hypothesis according to the procedure presented in Lachuer et al. (49 (link)) and detailed in the Monte Carlo section. Simulated average NND are compared to the observed NND. This allowed to classify the cell as clustered (NNDobserved < NNDsimulated), or dispersed (NNDobserved > NNDsimulated). Note that temporal NND were treated similarly to spatial NND, just by reducing the dimension of the analysis.
Lachuer H., Le L., Lévêque-Fort S., Goud B, & Schauer K. (2023). Spatial organization of lysosomal exocytosis relies on membrane tension gradients. Proceedings of the National Academy of Sciences of the United States of America, 120(8), e2207425120.
Publication 2023
Exocytosis

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1
Fm1 43 by Thermo Fisher Scientific
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FM1-43 is a fluorescent styryl dye used for the labeling and visualization of cell membranes and synaptic vesicle recycling in live cells. It is a lipophilic dye that inserts into the outer leaflet of the plasma membrane.
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GolgiPlug is a laboratory product designed to inhibit protein transport from the Golgi apparatus to the cell surface. It functions by blocking the secretory pathway, preventing the release of proteins from the Golgi complex. GolgiPlug is intended for use in cell biology research applications.
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Epc 10 amplifier by HEKA Elektronik
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The EPC-10 is a patch clamp amplifier designed for electrophysiology research. It provides the necessary voltage and current control for single-cell studies. The device offers high precision and low noise performance to enable accurate measurements of ionic currents and membrane potentials.
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RPMI 1640 is a common cell culture medium used for the in vitro cultivation of a variety of cells, including human and animal cells. It provides a balanced salt solution and a source of essential nutrients and growth factors to support cell growth and proliferation.
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More about "Exocytosis"

Exocytosis is the fundamental cellular process by which membrane-bound vesicles containing a variety of substances, such as proteins, hormones, neurotransmitters, and other biomolecules, are released from the cell.
This critical mechanism is essential for numerous physiological functions, including neurotransmitter release, hormone secretion, and immune response.
The regulated movement and fusion of these vesicles with the cell membrane enables the extracellular release of their contents.
Defects in exocytosis have been implicated in various diseases, making it an important area of biomedical research.
Optimizing exocytosis research is crucial for enhancing reproducibility and accuracy, leading to advancements in our understanding and treatment of related disorders.
Researchers often utilize techniques and tools like FM1-43 (a fluorescent dye used to study vesicle dynamics), GolgiPlug (a protein transport inhibitor), EPC-10 amplifier (a patch-clamp system for recording cellular electrical activity), RPMI 1640 (a cell culture medium), Lipofectamine 2000 (a transfection reagent), Patchmaster software (for electrophysiological data acquisition and analysis), FM4-64 (another fluorescent dye), Axio Observer Z1 (a fluorescence microscope), FBS (fetal bovine serum), and FV1000 (a confocal laser scanning microscope) to investigate the complex processes involved in exocytosis.
By leveraging these tools and techniques, researchers can optimize their exocytosis studies and enhance the reliability and reproducibility of their findings.