Cell Culture <ol><li> Stammkulturen von humanen embryonalen Nierenzellen 293 (HEK293-Zellen) sind in 10-cm Kulturschalen in &quot;Medium A &#39;, bestehend aus Dulbecco modifiziertem Eagle-Medium (DMEM) mit einem Cocktail von Antibiotika (100 Einheiten pro ml Penicillin und 100 ug ergänzt gewachsen pro ml Streptomycin-Sulfat) und 10% fötalem Rinderserum (FBS). </li><li> Zum Einrichten Zellen für ein Experiment, das Medium wird abgesaugt, und die Zellen werden zweimal mit 5 ml Phosphat-gepufferter Kochsalzlösung (PBS)-Lösung. </li><li> Das PBS wird dann entfernt und durch 0,6 ml einer Lösung mit 0,25% Trypsin. </li><li> Das Gericht wird bei 37 ˚ C für ca. 2 min inkubiert, bis die Zellen begonnen haben, zu lösen. </li><li> 5,5 ml Medium A zugesetzt wird, um das Trypsin zu neutralisieren und die Zellen mit einer Zählkammer gezählt. </li><li> Die Zellen werden auf 320.000 Zellen pro ml verdünnt und verzichtet auf 0,1 ml pro Vertiefung in einem Polylysin-beschichteten 96-well-Kulturplatte. </li><li> Setzen Sie die Schüssel in einer Gewebekultur-Inkubator bei 37 ˚ C mit einer Atmosphäre, die 8,8% CO2 und wachsen für 24 Stunden. </li></ol> Transfektionen <ol><li> In Vorbereitung für Transfektionen, sollte überlegt werden, wie viele Wiederholungen sind pro experimentellen Bedingungen durchgeführt werden und welche Mengen von Plasmid wird transfiziert werden. Wir routinemäßig alle Bedingungen in dreifacher Ausfertigung und transfizieren insgesamt 50 bis 100 ng Plasmid-DNA pro Vertiefung. Plasmid vermischt sollte mindestens ein Reporter Ausdruck Glühwürmchenluciferase und eine Kontroll-Plasmid Ausdruck Renilla Luziferase aus einem konstitutiven Promotor-Konstrukts. </li><li> Plasmid-Lösungen sind in 1,5-ml Reaktionsgefäße pipettiert und ergänzt mit 10 ul pro Probe von Serum-freien und Antibiotika-freien DMEM. Zum Beispiel, wenn 20 Vertiefungen mit 50 ug DNA transfiziert werden, fügen Sie 200 ul DMEM auf 1 pg DNA. </li><li> Um das DMEM / DNA-Lösung add 3 ul &#39;Transit 293 Reagenz &quot;(Mirus) pro pg DNA. Mix durch Pipettieren up &amp; down und lassen Sie die Proben bei Raumtemperatur stehen für mindestens 10 min. </li><li> Während dieser Zeit, entfernen Sie die Medien aus dem 96-Loch-Kulturplatte und ersetzen mit 90 ml frisches Medium A. </li><li> Zu jedem Well 10 ul der DMEM / DNA / Transit 293 Mischung. </li><li> Setzen Sie die Schüssel in einer Gewebekultur-Inkubator bei 37 ˚ C mit einer Atmosphäre, die 8,8% CO2 und wachsen für 24 Stunden. </li></ol> Phagozytose <ol><li> Bereiten Suspensionen, die mittel-B (ein 1:1-Gemisch von DMEM und Hams F12-Medium plus Antibiotika und 10% FBS) plus 0,75-um Latexkügelchen auf Null zu 1 mg pro ml. </li><li> Entfernen Sie die Medien aus dem 96-Loch-Kulturplatte und ersetzen mit 0,1 ml Bead-Suspensionen in Medium B </li><li> Drehen Sie die Platte für 2 min bei 1000 x g. </li><li> Die Zellen werden dann bei 37 ˚ C für 6 bis 16 Stunden kultiviert. Abhängig von den Bedingungen und der Promotor verwendet werden, um Laufwerk Luciferase, erhöhte Expression des Reportergens nach 1 bis 3 Stunden nachgewiesen werden können. </li><li> In denselben Fällen kann es erforderlich sein, um die Zellen mit Perlen für 30-60 min inkubieren, dann 2 Wäschen mit PBS auf unincorporated Perlen zu entfernen, und fügen Sie neue Medien vor Inkubation der Zellen für zusätzliche Zeiträume. </li></ol> Dual-GloTM Luciferase Assay <ol><li> Hinweis: unser Protokoll für die Verwendung dieses Kit unterscheidet sich in einigen Punkten von dem vom Hersteller empfohlen. Es wurde geändert, um die Menge an Reagenzien pro Probe zu reduzieren. </li><li> Bereiten Sie eine Lösung von 1 M DTT, teilen sich in mehrere kleine Portionen und bei -20 ˚ C. </li><li> Bereiten Sie eine Lyse-Puffer mit 20 mM Tris-HCl (pH 7,8), 10% (v / v) Glycerin und 0,5% (v / v) Triton X-100. Vor dem Gebrauch aliquoten Betrag für das Experiment benötigte und fügen Sie 1 ul pro ml von 1 M DTT und Protease-Inhibitor-Cocktail auf eine Endkonzentration von 0,5 bis 1x. Nicht wiederverwenden Überbleibsel DTT-Lösung. </li><li> Bei Verwendung der Dual-GloTM Kit zum ersten Mal, bereiten Sie die (firefly) Luciferase-Reagenz durch die Übertragung der gesamte Inhalt einer Flasche Dual-Luciferase GloTM Buffer (im Lieferumfang des Kits), um eine Flasche Dual-GloTM Luciferase Substrat (vorausgesetzt, mit dem Kit). Teilen Sie die unbenutzten Luciferase-Reagenz in 10-ml-Portionen und bei -20 ˚ C. </li><li> Entfernen Sie die 96-Well-Platte aus der Gewebekultur-Inkubator und legen Sie sie auf Eis. Entfernen Sie die Medien durch Aspiration, dann werden 40 ul pro Well Lysepuffer, und dann lassen Sie die Platte auf Eis für 30 min. </li><li> In einem weißen, undurchsichtigen 96-Well-Platte (OptiplateTM-96, Perkin Elmer Bestellnummer 6005290) Aliquot 15 ul pro Well Luciferase Reagenz, und fügen Sie dann 15 ul Zelllysat. </li><li> Die Platte bei Raumtemperatur für 10 min und lesen Sie dann die Lumineszenz in einem Mikroplatten-Reader. </li><li> Unmittelbar vor dem Gebrauch vorbereiten eine entsprechende Menge an Renilla Luciferase-Substrat-Lösung durch Zugabe von 1 Teil Dual-GloTM Stop &amp; Glo ®; Reagent (im Lieferumfang des Kits) und 100 Teile Dual-GloTM Stop &amp; Glo ® Buffer (im Lieferumfang des Kits). </li><li> Zu jedem Well 15 ul pro Well der Renilla Luciferase-Substrat-Lösung bei Raumtemperatur für 10 min inkubieren und messen Sie dann die Lumineszenz wieder. </li></ol>

The authors have nothing to disclose.

studying membrane biogenesis with a luciferase-based reporter gene assay

Zur Untersuchung der Koordination der verschiedenen Lipid-Synthesewege in Membran-Biogenese ist es sinnvoll, mit einem experimentellen System, in dem Membran-Biogenese erfolgt schnell und in einem induzierbaren Weise zu arbeiten. Wir haben festgestellt, dass die Phagozytose von Latex-Beads praktisch für diese Zwecke als Zellen schnell synthetisieren Membranlipide zu Membran-Pools als Verpackungsmaterial während Partikel engulfment verloren aufzufüllen. Hier beschreiben wir Verfahren für die Untersuchung von Veränderungen in Phagozytose-induzierte Genexpression mit einem Luciferase-basierten Reportergen-Ansatz mit dem Dual-Glo Luciferase Assay System von Promega.

Watch this Scientific Journal Video about Studying Membrane Biogenesis with a Luciferase-Based Reporter Gene Assay at JoVE.com

Studying Membrane Biogenesis with a Luciferase-Based Reporter Gene Assay

Hier beschreiben wir Verfahren für die Untersuchung von Veränderungen in Phagozytose-induzierte Genexpression mit einem Luciferase-basierten Reportergen-Ansatz mit dem Dual-GloTM Luciferase Assay System von Promega.

Studieren Membrane Biogenesis mit einem Luciferase-Based Reporter Gene Assay

To study the coordination of different lipid synthesis pathways during membrane biogenesis it is useful to work with an experimental system where membrane ...

studying-membrane-biogenesis-with-luciferase-based-reporter-gene

Research

JoVE Journal

Biology

12.8K Aufrufe.  Harvard. Hier beschreiben wir Verfahren für die Untersuchung von Veränderungen in Phagozytose-induzierte Genexpression mit einem Luciferase-basierten Reportergen-Ansatz mit dem Dual-GloTM Luciferase Assay System von Promega.

Serie: Studying Membrane Biogenesis with a Luciferase-Based Reporter Gene Assay

A Microfluidic Device with Groove Patterns for Studying Cellular Behavior

We describe a microfluidic device with microgrooved patterns for studying cellular behavior. This microfluidic platform consists of a top fluidic channel and a bottom microgrooved substrate. To fabricate the microgrooved channels, a top poly(dimethylsiloxane) (PDMS) mold containing the impression of the microfluidic channels was aligned and bonded to a microgrooved substrate. Using this device, mouse fibroblast cells were immobilized and patterned within microgrooved substrates (25, 50, 75, and 100 &mu;m wide). To study apoptosis in a microfluidic device, media containing hydrogen peroxide, Annexin V, and propidium iodide was perfused into the fluidic channel for 2 hours. We found that cells exposed to the oxidative stress became apoptotic. These apoptotic cells were confirmed by Annexin V that bound to phosphatidylserine at the outer leaflet of the plasma membrane during the apoptosis process. Using this microfluidic device with microgrooved patterns, the apoptosis process was observed in real-time and analyzed by using an inverted microscope containing an incubation chamber (37&deg;C, 5% CO2). Therefore, this microfluidic device incorporated with microgrooved substrates could be useful for studying the cellular behavior and performing high-throughput drug screening.

We describe a protocol for the fabrication of microfluidic devices that can enable cell capture and culture. In this approach patterned microstructures such as grooves within microfluidic channels are used to create low shear stress regions within which cell can dock.

Einer mikrofluidischen Vorrichtung mit Groove Patterns für ein Studium Cellular Behavior

We describe a microfluidic device with microgrooved patterns for studying cellular behavior.  This microfluidic platform consists of a top fluidic channel ...

Forschung

Biologie

Using the Gene Pulser MXcell Electroporation System to Transfect Primary Cells with High Efficiency

It is becoming increasingly apparent that electroporation is the most effective way to introduce plasmid DNA or siRNA into primary cells. The Gene Pulser MXcell electroporation system and Gene Pulser electroporation buffer (Bio-Rad) were specifically developed to easily transfect nucleic acids into mammalian cells and difficult-to-transfect cells, such as primary and stem cells. We will demonstrate how to perform a simple experiment to quickly identify the best electroporation conditions. We will demonstrate how to run several samples through a range of electroporation conditions so that an experiment can be conducted at the same time as optimization is performed. We will also show how optimal conditions identified using 96-well electroporation plates can be used with standard electroporation cuvettes, facilitating the switch from electroporation plates to electroporation cuvettes while maintaining the same electroporation efficiency. In the video, we will also discuss some of the key factors that can lead to the success or failure of electroporation experiments.

This procedure shows how to use the Gene Pulser MXcell electroporation system to rapidly and easily identify the best electroporation conditions for mouse embryonic fibroblasts (MEFs) or other primary cells. Considerations for troubleshooting are also discussed in the associated video.

Mit dem Gene Pulser MXcell Elektroporation System zur Primary Cells mit hohem Wirkungsgrad zu transfizieren

It is becoming increasingly apparent that electroporation is the most effective way to introduce plasmid DNA or siRNA into primary cells. The Gene Pulser ...

Floral-dip Transformation of Arabidopsis thaliana to Examine pTSO2::&beta;-glucuronidase Reporter Gene Expression

The ability to introduce foreign genes into an organism is the foundation for modern biology and biotechnology. In the model flowering plant Arabidopsis thaliana, the floral-dip transformation method1-2 has replaced all previous methods because of its simplicity, efficiency, and low cost. Specifically, shoots of young flowering Arabidopsis plants are dipped in a solution of Agrobacterium tumefaciens carrying specific plasmid constructs. After dipping, the plants are returned to normal growth and yield seeds, a small percentage of which are transformed with the foreign gene and can be selected for on medium containing antibiotics. This floral-dip method significantly facilitated Arabidopsis research and contributed greatly to our understanding of plant gene function. In this study, we use the floral-dip method to transform a reporter gene, &beta;-glucuronidase (GUS), under the control of TSO2 promoter. TSO2, coding for the Ribonucleotide Reductase (RNR) small subunit3, is a cell cycle regulated gene essential for dNDP biosynthesis in the S-phase of the cell cycle. Examination of GUS expression in transgenic Arabidopsis seedlings shows that TSO2 is expressed in actively dividing tissues. The reported experimental method and materials can be easily adapted not only for research but also for education at high school and college levels.

Floral-dip Transformation of Arabidopsis thaliana to Examine pTSO2::&#946;-glucuronidase Reporter Gene Expression

This article illustrates the floral-dip method of Agrobacterium tumefaciens -mediated transformation of Arabidopsis thaliana. By introducing a cell-cycle regulated promoter-reporter, pTSO2::&beta;-glucuronidase (GUS), into Arabidopsis, we illustrates how one detects GUS reporter expression in transgenic seedlings.

Floral-dip Transformation von Arabidopsis thaliana Zum Untersuchen PTSO2: β-Glucuronidase Reporter Gene Expression

The ability to introduce foreign genes into an organism is the foundation for modern biology and biotechnology. In the model flowering plant Arabidopsis ...

Agrobacterium-Mediated Virus-Induced Gene Silencing Assay In Cotton

Cotton (Gossypium hirsutum) is one of the most important crops worldwide. Considerable efforts have been made on molecular breeding of new varieties. The large-scale gene functional analysis in cotton has been lagged behind most of the modern plant species, likely due to its large size of genome, gene duplication and polyploidy, long growth cycle and recalcitrance to genetic transformation1. To facilitate high throughput functional genetic/genomic study in cotton, we attempt to develop rapid and efficient transient assays to assess cotton gene functions.
Virus-Induced Gene Silencing (VIGS) is a powerful technique that was developed based on the host Post-Transcriptional Gene Silencing (PTGS) to repress viral proliferation2,3. Agrobacterium-mediated VIGS has been successfully applied in a wide range of dicots species such as Solanaceae, Arabidopsis and legume species, and monocots species including barley, wheat and maize, for various functional genomic studies3,4. As this rapid and efficient approach avoids plant transformation and overcomes functional redundancy, it is particularly attractive and suitable for functional genomic study in crop species like cotton not amenable for transformation.
In this study, we report the detailed protocol of Agrobacterium-mediated VIGS system in cotton. Among the several viral VIGS vectors, the tobacco rattle virus (TRV) invades a wide range of hosts and is able to spread vigorously throughout the entire plant yet produce mild symptoms on the hosts5. To monitor the silencing efficiency, GrCLA1, a homolog gene of Arabidopsis Cloroplastos alterados 1 gene (AtCLA1) in cotton, has been cloned and inserted into the VIGS binary vector pYL156. CLA1 gene is involved in chloroplast development6, and previous studies have shown that loss-of-function of AtCLA1 resulted in an albino phenotype on true leaves7, providing an excellent visual marker for silencing efficiency. At approximately two weeks post Agrobacterium infiltration, the albino phenotype started to appear on the true leaves, with 100% silencing efficiency in all replicated experiments. The silencing of endogenous gene expression was also confirmed by RT-PCR analysis. Significantly, silencing could potently occur in all the cultivars we tested, including various commercially grown varieties in Texas. This rapid and efficient Agrobacterium-mediated VIGS assay provides a very powerful tool for rapid large-scale analysis of gene functions at genome-wide level in cotton.

We present the detailed protocol for Agrobacterium-mediated virus-induced gene silencing (VIGS) assay in cotton. The tobacco rattle virus (TRV)-derived VIGS vectors were deployed to induce RNA silencing of cotton GrCLA1, Cloroplastos alterados 1 gene. The albino phenotype caused by silencing GrCLA1 was observed at the seedling stage within 2 weeks after inoculation.

Agrobacterium-vermittelte Virus-induced gene silencing Assay In Cotton

Cotton (Gossypium hirsutum) is one of the most important crops worldwide. Considerable efforts have been made on molecular breeding of new varieties.  The ...

A Chemical Screening Procedure for Glucocorticoid Signaling with a Zebrafish Larva Luciferase Reporter System

Glucocorticoid stress hormones and their artificial derivatives are widely used drugs to treat inflammation, but long-term treatment with glucocorticoids can lead to severe side effects. Test systems are needed to search for novel compounds influencing glucocorticoid signaling in vivo or to determine unwanted effects of compounds on the glucocorticoid signaling pathway. We have established a transgenic zebrafish assay which allows the measurement of glucocorticoid signaling activity in vivo and in real-time, the GRIZLY assay (Glucocorticoid Responsive In vivo Zebrafish Luciferase activitY). The luciferase-based assay detects effects on glucocorticoid signaling with high sensitivity and specificity, including effects by compounds that require metabolization or affect endogenous glucocorticoid production. We present here a detailed protocol for conducting chemical screens with this assay. We describe data acquisition, normalization, and analysis, placing a focus on quality control and data visualization. The assay provides a simple, time-resolved, and quantitative readout. It can be operated as a stand-alone platform, but is also easily integrated into high-throughput screening workflows. It furthermore allows for many applications beyond chemical screening, such as environmental monitoring of endocrine disruptors or stress research.

We describe the procedure and data analysis of a chemical screening system for glucocorticoid stress hormone signaling using zebrafish larvae: the Glucocorticoid Responsive In vivo Zebrafish Luciferase activitY (GRIZLY) assay. The assay sensitively and specifically detects effects on glucocorticoid signaling by compounds that require metabolization or affect endogenous glucocorticoid production.

Eine Stoff Screening Verfahren für die Glucocorticoid-Signalisierung mit einem Zebrafisch-Larve Luciferase-Reportersystems

Glucocorticoid stress hormones and their artificial derivatives are widely used drugs to treat inflammation, but long-term treatment with glucocorticoids ...

Imaging Plasma Membrane Deformations With pTIRFM

To gain novel insights into the dynamics of exocytosis, our group focuses on the changes in lipid bilayer shape that must be precisely regulated during the fusion of vesicle and plasma membranes. These rapid and localized changes are achieved by dynamic interactions between lipids and specialized proteins that control membrane curvature. The absence of such interactions would not only have devastating consequences for vesicle fusion, but a host of other cellular functions that involve control of membrane shape. In recent years, the identity of a number of proteins with membrane-shaping properties has been determined. What remains missing is a roadmap of when, where, and how they act as fusion and content release progress.
Our understanding of the molecular events that enable membrane remodeling has historically been limited by a lack of analytical methods that are sensitive to membrane curvature or have the temporal resolution to track rapid changes. PTIRFM satisfies both of these criteria. We discuss how pTIRFM is implemented to visualize and interpret rapid, submicron changes in the orientation of chromaffin cell membranes during dense core vesicle (DCV) fusion. The chromaffin cells we use are isolated from bovine adrenal glands. The membrane is stained with a lipophilic carbocyanine dye,1,1&#39;-dioctadecyl-3,3,3&#39;,3&#39;-tetramethylindodicarbocyanine, 4-chlorobenzenesulfonate, or&#160;diD. DiD intercalates in the membrane plane with a &#34;fixed&#34; orientation and is therefore sensitive to the polarization of the evanescent field. The diD-stained cell membrane is sequentially excited with orthogonal polarizations of a 561&#160;nm laser (p-pol, s-pol). A 488&#160;nm laser is used to visualize vesicle constituents and time the moment of fusion. Exocytosis is triggered by locally perfusing cells with a depolarizing KCl solution. Analysis is performed offline using custom-written software to understand how diD emission intensity changes relate to fusion pore dilation.

Polarization-based Total Internal Reflection Fluorescence Microscopy (pTIRFM) enables real-time detection of cell membrane dynamics. This article describes the implementation of pTIRFM for the study of membrane remodeling during regulated exocytosis. The technique is generalizable to other processes in cell biology that directly or indirectly involve changes in membrane shape.

Imaging Plasmamembran Verformungen Mit pTIRFM

To gain novel insights into the dynamics of exocytosis, our group focuses on the changes in lipid bilayer shape that must be precisely regulated during ...

Reporter-based Growth Assay for Systematic Analysis of Protein Degradation

Protein degradation by the ubiquitin-proteasome system (UPS) is a major regulatory mechanism for protein homeostasis in all eukaryotes. The standard approach to determining intracellular protein degradation relies on biochemical assays for following the kinetics of protein decline. Such methods are often laborious and time consuming and therefore not amenable to experiments aimed at assessing multiple substrates and degradation conditions. As an alternative, cell growth-based assays have been developed, that are, in their conventional format, end-point assays that cannot quantitatively determine relative changes in protein levels.
Here we describe a method that faithfully determines changes in protein degradation rates by coupling them to yeast cell-growth kinetics. The method is based on an established selection system where uracil auxotrophy of URA3-deleted yeast cells is rescued by an exogenously expressed reporter protein, comprised of a fusion between the essential URA3 gene and a degradation determinant (degron). The reporter protein is designed so that its synthesis rate is constant whilst its degradation rate is determined by the degron. As cell growth in uracil-deficient medium is proportional to the relative levels of Ura3, growth kinetics are entirely dependent on the reporter protein degradation.
This method accurately measures changes in intracellular protein degradation kinetics. It was applied to: (a) Assessing the relative contribution of known ubiquitin-conjugating factors to proteolysis (b) E2 conjugating enzyme structure-function analyses (c) Identification and characterization of novel degrons. Application of the degron-URA3-based system transcends the protein degradation field, as it can also be adapted to monitoring changes of protein levels associated with functions of other cellular pathways.

Here we describe a robust biological assay for quantifying the relative rate of proteolysis by the ubiquitin-proteasome system. The assay readout is yeast growth rate in liquid culture, which is dependent on the cellular levels of a reporter protein comprising a degradation signal fused to an essential metabolic marker.

Reporter-basierten Wachstumstest für die systematische Analyse von Proteinabbau

Protein degradation by the ubiquitin-proteasome system (UPS) is a major regulatory mechanism for protein homeostasis in all eukaryotes. The standard ...

Transfecting RAW264.7 Cells with a Luciferase Reporter Gene

Transfection of desired genetic materials into cells is an inevitable procedure in biomedical research studies. While numerous methods have been described, certain types of cells are resistant to many of these methods and yield low transfection efficiency1, potentially hindering research in those cell types. In this protocol, we present an optimized transfection procedure to introduce luciferase reporter genes as a plasmid DNA into the RAW264.7 macrophage cell line. Two different types of transfection reagents (lipid-based and polyamine-based) are described, and important notes are given throughout the protocol to ensure that the RAW264.7 cells are minimally altered by the transfection procedure and any experimental data obtained are the direct results of the experimental treatment. While transfection efficiency may not be higher compared to other transfection methods, the described procedure is robust enough for detecting luciferase signal in RAW264.7 without changing the physiological response of the cells to stimuli.

Transfection into the macrophage cell line, RAW264.7, is difficult due to the cell&#8217;s natural response against foreign materials. We described here a gentle yet robust procedure for transfecting luciferase reporter genes into RAW264.7 cells.

Transfizieren RAW264.7-Zellen mit einem Luciferase-Reportergen

Transfection of desired genetic materials into cells is an inevitable procedure in biomedical research studies. While numerous methods have been ...

Visualizing Stromule Frequency with Fluorescence Microscopy

Stromules, or "stroma-filled tubules", are narrow, tubular extensions from the surface of the chloroplast that are universally observed in plant cells but whose functions remain mysterious. Alongside growing attention on the role of chloroplasts in coordinating plant responses to stress, interest in stromules and their relationship to chloroplast signaling dynamics has increased in recent years, aided by advances in fluorescence microscopy and protein fluorophores that allow for rapid, accurate visualization of stromule dynamics. Here, we provide detailed protocols to assay stromule frequency in the epidermal chloroplasts of Nicotiana benthamiana, an excellent model system for investigating chloroplast stromule biology. We also provide methods for visualizing chloroplast stromules in vitro by extracting chloroplasts from leaves. Finally, we outline sampling strategies and statistical approaches to analyze differences in stromule frequencies in response to stimuli, such as environmental stress, chemical treatments, or gene silencing. Researchers can use these protocols as a starting point to develop new methods for innovative experiments to explore how and why chloroplasts make stromules.

Protocols to investigate the dynamics of chloroplast stromules, the stroma-filled tubules that extend from the surface of chloroplasts, are described.

Visualizing Stromulus Frequenz mit Fluoreszenzmikroskopie

Stromules, or "stroma-filled tubules", are narrow, tubular extensions from the surface of the chloroplast that are universally observed in plant cells but ...

An In Vitro Model for Studying Cellular Transformation by Kaposi Sarcoma Herpesvirus

Kaposi sarcoma (KS) is an unusual tumor composed of proliferating spindle cells that is initiated by infection of endothelial cells (EC) with KSHV, and develops most often in the setting of immunosuppression. Despite decades of research, optimal treatment of KS remains poorly defined and clinical outcomes are especially unfavorable in resource-limited settings. KS lesions are driven by pathological angiogenesis, chronic inflammation, and oncogenesis, and various in vitro cell culture models have been developed to study these processes. KS arises from KSHV-infected cells of endothelial origin, so EC-lineage cells provide the most appropriate in vitro surrogates of the spindle cell precursor. However, because EC have a limited in vitro lifespan, and as the oncogenic mechanisms employed by KSHV are less efficient than those of other tumorigenic viruses, it has been difficult to assess the processes of transformation in primary or telomerase-immortalized EC. Therefore, a novel EC-based culture model was developed that readily supports transformation following infection with KSHV. Ectopic expression of the E6 and E7 genes of human papillomavirus type 16 allows for extended culture of age- and passage-matched mock- and KSHV-infected EC and supports the development of a truly transformed (i.e., tumorigenic) phenotype in infected cell cultures. This tractable and highly reproducible model of KS has facilitated the discovery of several essential signaling pathways with high potential for translation into clinical settings.

An In Vitro Model for Studying Cellular Transformation by Kaposi Sarcoma Herpesvirus

Kaposi sarcoma (KS) is a tumor induced by infection with the oncogenic virus human herpesvirus-8/KS herpesvirus (HHV-8/KSHV). The endothelial cell culture model described here is uniquely suited for studying the mechanisms by which KSHV transforms host cells.

Ein In-vitro- Modell für die Erforschung der zellulären Transformation von Kaposi-Sarkom-Herpesvirus

Kaposi sarcoma (KS) is an unusual tumor composed of proliferating spindle cells that is initiated by infection of endothelial cells (EC) with KSHV, and ...