Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Plasmonic imaging of subcellular electromechanical deformation in mammalian cells.

ABSTRACT: A membrane potential change in cells is accompanied with mechanical deformation. This electromechanical response can play a significant role in regulating action potential in neurons and in controlling voltage-gated ion channels. However, measuring this subtle deformation in mammalian cells has been a difficult task. We show a plasmonic imaging method to image mechanical deformation in single cells upon a change in the membrane potential. Using this method, we have studied the electromechanical response in mammalian cells and have observed the local deformation within the cells that are associated with cell-substrate interactions. By analyzing frequency dependence of the response, we have further examined the electromechanical deformation in terms of mechanical properties of cytoplasm and cytoskeleton. We demonstrate a plasmonic imaging approach to quantify the electromechanical responses of single mammalian cells and determine local variability related to cell-substrate interactions.

SUBMITTER: Yang Y

PROVIDER: S-EPMC6586072 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Plasmonic imaging of subcellular electromechanical deformation in mammalian cells.

Yang Yunze Y Liu Xianwei X Wang Shaopeng S Tao Nongjian N

Journal of biomedical optics 20190601 6

A membrane potential change in cells is accompanied with mechanical deformation. This electromechanical response can play a significant role in regulating action potential in neurons and in controlling voltage-gated ion channels. However, measuring this subtle deformation in mammalian cells has been a difficult task. We show a plasmonic imaging method to image mechanical deformation in single cells upon a change in the membrane potential. Using this method, we have studied the electromechanical ...[more]

PMID: 31222988

Similar Datasets

4D cardiac electromechanical activation imaging.

Project description:Cardiac abnormalities, a major cause of morbidity and mortality, affect millions of people worldwide. Despite the urgent clinical need for early diagnosis, there is currently no noninvasive technique that can infer to the electrical function of the whole heart in 3D and thereby localize abnormalities at the point of care. Here we present a new method for noninvasive 4D mapping of the cardiac electromechanical activity in a single heartbeat for heart disease characterization such as arrhythmia and infarction. Our novel technique captures the 3D activation wave of the heart in vivo using high volume-rate (500 volumes per second) ultrasound with a 32?×?32 matrix array. Electromechanical activation maps are first presented in a normal and infarcted cardiac model in silico and in canine heart during pacing and re-entrant ventricular tachycardia in vivo. Noninvasive 4D electromechanical activation mapping in a healthy volunteer and a heart failure patient are also determined. The technique described herein allows for direct, simultaneous and noninvasive visualization of electromechanical activation in 3D, which provides complementary information on myocardial viability and/or abnormality to clinical imaging.

| S-EPMC6817394 | biostudies-literature

Optimized Vivid-derived Magnets photodimerizers for subcellular optogenetics in mammalian cells.

Project description:Light-inducible dimerization protein modules enable precise temporal and spatial control of biological processes in non-invasive fashion. Among them, Magnets are small modules engineered from the Neurospora crassa photoreceptor Vivid by orthogonalizing the homodimerization interface into complementary heterodimers. Both Magnets components, which are well-tolerated as protein fusion partners, are photoreceptors requiring simultaneous photoactivation to interact, enabling high spatiotemporal confinement of dimerization with a single excitation wavelength. However, Magnets require concatemerization for efficient responses and cell preincubation at 28°C to be functional. Here we overcome these limitations by engineering an optimized Magnets pair requiring neither concatemerization nor low temperature preincubation. We validated these 'enhanced' Magnets (eMags) by using them to rapidly and reversibly recruit proteins to subcellular organelles, to induce organelle contacts, and to reconstitute OSBP-VAP ER-Golgi tethering implicated in phosphatidylinositol-4-phosphate transport and metabolism. eMags represent a very effective tool to optogenetically manipulate physiological processes over whole cells or in small subcellular volumes.

| S-EPMC7735757 | biostudies-literature

Targeted nanodiamonds for identification of subcellular protein assemblies in mammalian cells.

Project description:Transmission electron microscopy (TEM) can be used to successfully determine the structures of proteins. However, such studies are typically done ex situ after extraction of the protein from the cellular environment. Here we describe an application for nanodiamonds as targeted intensity contrast labels in biological TEM, using the nuclear pore complex (NPC) as a model macroassembly. We demonstrate that delivery of antibody-conjugated nanodiamonds to live mammalian cells using maltotriose-conjugated polypropylenimine dendrimers results in efficient localization of nanodiamonds to the intended cellular target. We further identify signatures of nanodiamonds under TEM that allow for unambiguous identification of individual nanodiamonds from a resin-embedded, OsO4-stained environment. This is the first demonstration of nanodiamonds as labels for nanoscale TEM-based identification of subcellular protein assemblies. These results, combined with the unique fluorescence properties and biocompatibility of nanodiamonds, represent an important step toward the use of nanodiamonds as markers for correlated optical/electron bioimaging.

| S-EPMC5479563 | biostudies-literature

Biocompatibility, uptake and subcellular localization of bacterial magnetosomes in mammalian cells.

Project description:Magnetosomes represent biogenic, magnetic nanoparticles biosynthesized by magnetotactic bacteria. Subtle biological control on each step of biomineralization generates core-shell nanoparticles of high crystallinity, strong magnetization and uniform shape and size. These features make magnetosomes a promising alternative to chemically synthesized nanoparticles for many applications in the biotechnological and biomedical field, such as their usage as biosensors in medical diagnostics, as drug-delivery agents, or as contrast agents for magnetic imaging techniques. Thereby, the particles are directly applied to mammalian cells or even injected into the body. In the present work, we provide a comprehensive characterization of isolated magnetosomes as potential cytotoxic effects and particle uptake have not been well studied so far. Different cell lines including cancer cells and primary cells are incubated with increasing particle amounts, and effects on cell viability are investigated. Obtained data suggest a concentration-dependent biocompatibility of isolated magnetosomes for all tested cell lines. Furthermore, magnetosome accumulation in endolysosomal structures around the nuclei is observed. Proliferation rates are affected in the presence of increasing particle amounts; however, viability is not affected and doubling times can be restored by reducing the magnetosome concentration. In addition, we evidence magnetosome-cell interactions that are strong enough to allow for magnetic cell sorting. Overall, our study not only assesses the biocompatibility of isolated magnetosomes, but also evaluates effects on cell proliferation and the fate of internalized magnetosomes, thereby providing prerequisites for their future in vivo application as biomedical agents.

| S-EPMC8243654 | biostudies-literature

Magnetic Separation of Autophagosomes from Mammalian Cells Using Magnetic-Plasmonic Hybrid Nanobeads.

Project description:Developments in subcellular fractionation strategies have provided the means to analyze the protein and lipid composition of organelles by proteomics. Here, we developed ultrasmall magnetic-plasmonic hybrid nanobeads and applied them to the isolation of autophagosomes by applying a magnetic field. The beads were chemically synthesized and comprised an Ag/FeCo/Ag core/shell/shell structure with a mean diameter of 15 nm. The Ag core and the FeCo shell conferred imaging and magnetic separation capabilities, respectively. The nanobeads were transfected into mammalian cells by lipofection. Thirty minutes after lipofection, the nanobeads colocalized with Vps26 and subsequently with LC3. Cell lysates were prepared at the appropriate time points and were subjected to magnetic separation. The separated fraction contained LC3-II, transferrin receptor, and LAMP2, but not LC3-I, suggesting that autophagosomes engulfing endosomal origin had been isolated. The magnetic separation process was completed in less than 30 min, providing a rapid method for isolation of autophagosomes. The present organelle isolation technique using the hybrid nanobeads with imaging and magnetic separation capabilities is highly promising for isolation of other types of organelles such as endosomes and endosome-related organelles.

| S-EPMC6044991 | biostudies-literature

Subcellular Imaging of Liquid Silicone Coated-Intestinal Epithelial Cells.

Project description:Surface contamination and the formation of water bridge at the nanoscopic contact between an atomic force microscope tip and cell surface limits the maximum achievable spatial resolution on cells under ambient conditions. Structural information from fixed intestinal epithelial cell membrane is enhanced by fabricating a silicone liquid membrane that prevents ambient contaminants and accumulation of water at the interface between the cell membrane and the tip of an atomic force microscope. The clean and stable experimental platform permits the visualisation of the structure and orientation of microvilli present at the apical cell membrane under standard laboratory conditions together with registering subcellular details within a microvillus. The method developed here can be implemented for preserving and imaging contaminant-free morphology of fixed cells which is central for both fundamental studies in cell biology and in the emerging field of digital pathology.

| S-EPMC6050225 | biostudies-literature

Plasmonic labeling of subcellular compartments in cancer cells: multiplexing with fine-tuned gold and silver nanoshells.

Project description:Fine-tuned gold and silver nanoshells were produced via an entirely reformulated synthesis. The new method yielded ultramonodisperse samples, with polydispersity indexes (PI) as low as 0.02 and narrow extinction bands suited for multiplex analysis. A library of nanoshell samples with localized surface plasmon resonances (LSPR) spanning across the visible range was synthesized. Hyperspectral analysis revealed that the average scattering spectrum of 100 nanoshells matched closely to the spectrum of a single nanoshell, indicating an unprecedented low level of nanoparticle-to-nanoparticle variation for this type of system. A cell labeling experiment, targeting different subcellular compartments in MCF-7 human breast cancer cells, demonstrated that these monodisperse nanoparticles can be used as a multiplex platform for single cell analysis at the intracellular and extracellular level. Antibody-coated gold nanoshells targeted the plasma membrane, while silver nanoshells coated with a nuclear localization signal (NLS) targeted the nuclear membrane. A fluorescence counterstaining experiment, as well as single cell hyperspectral microscopy showed the excellent selectivity and specificity of each type of nanoparticle for its designed subcellular compartment. A time-lapse photodegradation experiment confirmed the enhanced stability of the nanoshells over fluorescent labeling and their capabilities for long-term live cell imaging.

| S-EPMC5380877 | biostudies-literature

Imaging through plasmonic nanoparticles.

Project description:The optical properties of metallic nanoparticles with plasmon resonances have been studied extensively, typically by measuring the transmission of light, as a function of wavelength, through a nanoparticle suspension. One question that has not yet been addressed, however, is how an image is transmitted through such a suspension of absorber-scatterers, in other words, how the various spatial frequencies are attenuated as they pass through the nanoparticle host medium. Here, we examine how the optical properties of a suspension of plasmonic nanoparticles affect the transmitted image. We use two distinct ways to assess transmitted image quality: the structural similarity index (SSIM), a perceptual distortion metric based on the human visual system, and the modulation transfer function (MTF), which assesses the resolvable spatial frequencies. We show that perceived image quality, as well as spatial resolution, are both dependent on the scattering and absorption cross-sections of the constituent nanoparticles. Surprisingly, we observe a nonlinear dependence of image quality on optical density by varying optical path length and nanoparticle concentration. This work is a first step toward understanding the requirements for visualizing and resolving objects through media consisting of subwavelength absorber-scatterer structures, an approach that should also prove useful in the assessment of metamaterial or metasurface-based optical imaging systems.

| S-EPMC4878496 | biostudies-literature

Predicting the targeting of tail-anchored proteins to subcellular compartments in mammalian cells.

Project description:Tail-anchored (TA) proteins contain a single transmembrane domain (TMD) at the C-terminus that anchors them to the membranes of organelles where they mediate critical cellular processes. Accordingly, mutations in genes encoding TA proteins have been identified in a number of severe inherited disorders. Despite the importance of correctly targeting a TA protein to its appropriate membrane, the mechanisms and signals involved are not fully understood. In this study, we identify additional peroxisomal TA proteins, discover more proteins that are present on multiple organelles, and reveal that a combination of TMD hydrophobicity and tail charge determines targeting to distinct organelle locations in mammals. Specifically, an increase in tail charge can override a hydrophobic TMD signal and re-direct a protein from the ER to peroxisomes or mitochondria and vice versa. We show that subtle changes in those parameters can shift TA proteins between organelles, explaining why peroxisomes and mitochondria have many of the same TA proteins. This enabled us to associate characteristic physicochemical parameters in TA proteins with particular organelle groups. Using this classification allowed successful prediction of the location of uncharacterized TA proteins for the first time.

| S-EPMC5450235 | biostudies-literature

Plasmonic-Based Electrochemical Impedance Imaging of Electrical Activities in Single Cells.

Project description:Studying electrical activities in cells, such as action potential and its propagation in neurons, requires a sensitive and non-invasive analytical tool that can image local electrical signals with high spatial and temporal resolutions. Here we report a plasmonic-based electrochemical impedance imaging technique to study transient electrical activities in single cells. The technique is based on the conversion of the electrical signal into a plasmonic signal, which is imaged optically without labels. We demonstrate imaging of the fast initiation and propagation of action potential within single neurons, and validate the imaging technique with the traditional patch clamp technique. We anticipate that the plasmonic imaging technique will contribute to the study of electrical activities in various cellular processes.

| S-EPMC5837822 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data