Browse
Submit Data
Databases
API
Help

Dataset Information

22 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Reporter gene assay for membrane fusion of extracellular vesicles.

ABSTRACT: Extracellular vesicles (EVs) secreted by living cells are expected to deliver biological cargo molecules, including RNA and proteins, to the cytoplasm of recipient cells. There is an increasing need to understand the mechanism of intercellular cargo delivery by EVs. However, the lack of a feasible bioassay has hampered our understanding of the biological processes of EV uptake, membrane fusion, and cargo delivery to recipient cells. Here, we describe a reporter gene assay that can measure the membrane fusion efficiency of EVs during cargo delivery to recipient cells. When EVs containing tetracycline transactivator (tTA)-fused tetraspanins are internalized by recipient cells and fuse with cell membranes, the tTA domain is exposed to the cytoplasm and cleaved by tobacco etch virus protease to induce tetracycline responsive element (TRE)-mediated reporter gene expression in recipient cells. This assay (designated as EV-mediated tetraspanin-tTA delivery assay, ETTD assay), enabled us to assess the cytoplasmic cargo delivery efficiency of EVs in recipient cells. With the help of a vesicular stomatitis virus-derived membrane fusion protein, the ETTD assay could detect significant enhancement of cargo delivery efficiency of EVs. Furthermore, the ETTD assay could evaluate the effect of potential cargo delivery enhancers/inhibitors. Thus, the ETTD assay may contribute to a better understanding of the underlying mechanism of the cytoplasmic cargo delivery by EVs.

SUBMITTER: Somiya M

PROVIDER: S-EPMC8607979 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Dynamic biodistribution of extracellular vesicles in vivo using a multimodal imaging reporter.

Project description:Extracellular vesicles (EVs) are nanosized vesicles released by normal and diseased cells as a novel form of intercellular communication and can serve as an effective therapeutic vehicle for genes and drugs. Yet, much remains unknown about the in vivo properties of EVs such as tissue distribution, blood levels, and urine clearance, important parameters that will define their therapeutic effectiveness and potential toxicity. Here we combined Gaussia luciferase and metabolic biotinylation to create a sensitive EV reporter (EV-GlucB) for multimodal imaging in vivo, as well as monitoring of EV levels in the organs and biofluids ex vivo after administration of EVs. Bioluminescence and fluorescence-mediated tomography imaging on mice displayed a predominant localization of intravenously administered EVs in the spleen followed by the liver. Monitoring EV signal in the organs, blood, and urine further revealed that the EVs first undergo a rapid distribution phase followed by a longer elimination phase via hepatic and renal routes within six hours, which are both faster than previously reported using dye-labeled EVs. Moreover, we demonstrate systemically injected EVs can be delivered to tumor sites within an hour following injection. Altogether, we show the EVs are dynamically processed in vivo with accurate spatiotemporal resolution and target a number of normal organs as well as tumors with implications for disease pathology and therapeutic design.

| S-EPMC3934350 | biostudies-literature

A cell-based assay for CD63-containing extracellular vesicles.

Project description:Extracellular vesicles (EVs) are thought to be important in cell-cell communication and have elicited extraordinary interest as potential biomarkers of disease. However, quantitative methods to enable elucidation of mechanisms underlying release are few. Here, we describe a cell-based assay for monitoring EV release using the EV-enriched tetraspanin CD63 fused to the small, ATP-independent reporter enzyme, Nanoluciferase. Release of CD63-containing EVs from stably expressing cell lines was monitored by comparing luciferase activity in culture media to that remaining in cells. HEK293, U2OS, U87 and SKMel28 cells released 0.3%-0.6% of total cellular CD63 in the form of EVs over 5 hrs, varying by cell line. To identify cellular machinery important for secretion of CD63-containing EVs, we performed a screen of biologically active chemicals in HEK293 cells. While a majority of compounds did not significantly affect EV release, treating cells with the plecomacrolides bafilomycin or concanamycin, known to inhibit the V-ATPase, dramatically increased EV release. Interestingly, alkalization of the endosomal lumen using weak bases had no effect, suggesting a pH-independent enhancement of EV release by V-ATPase inhibitors. The ability to quantify EVs in small samples will enable future detailed studies of release kinetics as well as further chemical and genetic screening to define pathways involved in EV secretion.

| S-EPMC6655660 | biostudies-literature

Broadly Applicable, Virus-Free Dual Reporter Assay to Identify Compounds Interfering with Membrane Fusion: Performance for HSV-1 and SARS-CoV-2.

Project description:Membrane fusion constitutes an essential step in the replication cycle of numerous viral pathogens, hence it represents an important druggable target. In the present study, we established a virus-free, stable reporter fusion inhibition assay (SRFIA) specifically designed to identify compounds interfering with virus-induced membrane fusion. The dual reporter assay is based on two stable Vero cell lines harboring the third-generation tetracycline (Tet3G) transactivator and a bicistronic reporter gene cassette under the control of the tetracycline responsive element (TRE3G), respectively. Cell-cell fusion by the transient transfection of viral fusogens in the presence of doxycycline results in the expression of the reporter enzyme secreted alkaline phosphatase (SEAP) and the fluorescent nuclear localization marker EYFPNuc. A constitutively expressed, secreted form of nanoluciferase (secNLuc) functioned as the internal control. The performance of the SRFIA was tested for the quantification of SARS-CoV-2- and HSV-1-induced cell-cell fusion, respectively, showing high sensitivity and specificity, as well as the reliable identification of known fusion inhibitors. Parallel quantification of secNLuc enabled the detection of cytotoxic compounds or insufficient transfection efficacy. In conclusion, the SRFIA reported here is well suited for high-throughput screening for new antiviral agents and essentially will be applicable to all viral fusogens causing cell-cell fusion in Vero cells.

| S-EPMC9322530 | biostudies-literature

Active endocannabinoids are secreted on extracellular membrane vesicles.

Project description:Endocannabinoids primarily influence neuronal synaptic communication within the nervous system. To exert their function, endocannabinoids need to travel across the intercellular space. However, how hydrophobic endocannabinoids cross cell membranes and move extracellularly remains an unresolved problem. Here, we show that endocannabinoids are secreted through extracellular membrane vesicles produced by microglial cells. We demonstrate that microglial extracellular vesicles carry on their surface N-arachidonoylethanolamine (AEA), which is able to stimulate type-1 cannabinoid receptors (CB1), and inhibit presynaptic transmission, in target GABAergic neurons. This is the first demonstration of a functional role of extracellular vesicular transport of endocannabinoids.

| S-EPMC4328748 | biostudies-literature

Reporter mice for isolating and auditing cell type-specific extracellular vesicles in vivo.

Project description:Extracellular vesicles (EVs) are abundant, lipid-enclosed vectors that contain nucleic acids and proteins, they can be secreted from donor cells and freely circulate, and they can be engulfed by recipient cells thus enabling systemic communication between heterotypic cell types. However, genetic tools for labeling, isolating, and auditing cell type-specific EVs in vivo, without prior in vitro manipulation, are lacking. We have used CRISPR-Cas9-mediated genome editing to generate mice bearing a CD63-emGFPloxP/stop/loxP knock-in cassette that enables the specific labeling of circulating CD63+ vesicles from any cell type when crossed with lineage-specific Cre recombinase driver mice. As proof-of-principle, we have crossed these mice with Cdh5-CreERT2 mice to generate CD63emGFP+ vasculature. Using these mice, we show that developing vasculature is marked with emerald GFP (emGFP) following tamoxifen administration to pregnant females. In adult mice, quiescent vasculature and angiogenic vasculature (in tumors) is also marked with emGFP. Moreover, whole plasma-purified EVs contain a subpopulation of emGFP+ vesicles that are derived from the endothelium, co-express additional EV (e.g., CD9 and CD81) and endothelial cell (e.g., CD105) markers, and they harbor specific miRNAs (e.g., miR-126, miR-30c, and miR-125b). This new mouse strain should be a useful genetic tool for generating cell type-specific, CD63+ EVs that freely circulate in serum and can subsequently be isolated and characterized using standard methodologies.

| S-EPMC7405599 | biostudies-literature

Membrane-binding peptides for extracellular vesicles on-chip analysis.

Project description:Small extracellular vesicles (sEVs) present fairly distinctive lipid membrane features in the extracellular environment. These include high curvature, lipid-packing defects and a relative abundance in lipids such as phosphatidylserine and ceramide. sEV membrane could be then considered as a "universal" marker, alternative or complementary to traditional, characteristic, surface-associated proteins. Here, we introduce the use of membrane-sensing peptides as new, highly efficient ligands to directly integrate sEV capturing and analysis on a microarray platform. Samples were analysed by label-free, single-particle counting and sizing, and by fluorescence co-localisation immune staining with fluorescent anti-CD9/anti-CD63/anti-CD81 antibodies. Peptides performed as selective yet general sEV baits and showed a binding capacity higher than anti-tetraspanins antibodies. Insights into surface chemistry for optimal peptide performances are also discussed, as capturing efficiency is strictly bound to probes surface orientation effects. We anticipate that this new class of ligands, also due to the versatility and limited costs of synthetic peptides, may greatly enrich the molecular toolbox for EV analysis.

| S-EPMC7178839 | biostudies-literature

Extracellular membrane vesicles and phytopathogenicity of Acholeplasma laidlawii PG8.

Project description:For the first time, the phytopathogenicity of extracellular vesicles of Acholeplasma laidlawii PG8 (a ubiquitous mycoplasma that is one of the five common species of cell culture contaminants and is a causative agent for phytomycoplasmoses) in Oryza sativa L. plants was studied. Data on the ability of extracellular vesicles of Acholeplasma laidlawii PG8 to penetrate from the nutrient medium into overground parts of Oryza sativa L. through the root system and to cause alterations in ultrastructural organization of the plants were presented. As a result of the analysis of ultrathin leaf sections of plants grown in medium with A. laidlawii PG8 vesicles, we detected significant changes in tissue ultrastructure characteristic to oxidative stress in plants as well as their cultivation along with bacterial cells. The presence of nucleotide sequences of some mycoplasma genes within extracellular vesicles of Acholeplasma laidlawii PG8 allowed a possibility to use PCR (with the following sequencing) to perform differential detection of cells and bacterial vesicles in samples under study. The obtained data may suggest the ability of extracellular vesicles of the mycoplasma to display in plants the features of infection from the viewpoint of virulence criteria--invasivity, infectivity--and toxigenicity--and to favor to bacterial phytopathogenicity.

| S-EPMC3515904 | biostudies-literature

Alveolar macrophage-derived extracellular vesicles inhibit endosomal fusion of influenza virus.

Project description:Alveolar macrophages (AMs) and epithelial cells (ECs) are the lone resident lung cells positioned to respond to pathogens at early stages of infection. Extracellular vesicles (EVs) are important vectors of paracrine signaling implicated in a range of (patho)physiologic contexts. Here we demonstrate that AMs, but not ECs, constitutively secrete paracrine activity localized to EVs which inhibits influenza infection of ECs in vitro and in vivo. AMs exposed to cigarette smoke extract lost the inhibitory activity of their secreted EVs. Influenza strains varied in their susceptibility to inhibition by AM-EVs. Only those exhibiting early endosomal escape and high pH of fusion were inhibited via a reduction in endosomal pH. By contrast, strains exhibiting later endosomal escape and lower fusion pH proved resistant to inhibition. These results extend our understanding of how resident AMs participate in host defense and have broader implications in the defense and treatment of pathogens internalized within endosomes.

| S-EPMC7429743 | biostudies-literature

FRET-Based Assay for the Quantification of Extracellular Vesicles and Other Vesicles of Complex Composition.

Project description:Research in the field of extracellular vesicles is rapidly expanding and finding footholds in many areas of medical science. However, the availability of methodologies to quantify the concentration of membrane material present in a sample remains limited. Herein, we present a novel approach for the quantification of vesicle material, specifically the quantification of the total lipid membrane surface area, found in a sample using Förster resonance energy transfer (FRET). In this assay, sonication is used to drive the fusion between vesicles in the sample to be quantified and liposomes containing a pair of FRET fluorophores. The change in emission spectrum upon vesicle fusion is directly related to the total membrane surface area of the sample added, and a calibration curve allows for the quantification of a variety of vesicle species, including enveloped viruses, bacterial outer membrane vesicles, and mammalian extracellular vesicles. Without extensive optimization of experimental parameters, we were able to quantify down to ∼109 vesicles/mL, using as little as 60 μL of the sample. The assay precision was comparable to that of a commercial nanoparticle tracking analysis system. While its limit of detection was slightly higher, the FRET assay is superior for the detection of small vesicles, as its performance is vesicle-size-independent. Taken together, the FRET assay is a simple, robust, and versatile method for the quantification of a variety of purified vesicle samples.

| S-EPMC7735656 | biostudies-literature

Alveolar Macrophage-Derived Extracellular Vesicles Inhibit Endosomal Fusion of Influenza Virus

| S-SCDT-EMBOJ-2020-105057 | biostudies-other