La GFP-β-actina plasmide è stato generosamente offerto dal Dr. Wayne Orr, LSUHSC-S Dipartimento di Patologia, ed è stato amplificato nel laboratorio del Dr. Becky Worthylake, LSUHSC-NO Dipartimento di Farmacologia. Questo lavoro è stato sostenuto dalle concessioni dal National Institutes of Health (P20 RR-018766) e l&#39;American Heart Association (05835386N).

<ol>
	<li>Spindler, V., Schlegel, N., Waschke, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+GTPases+in+control+of+microvascular+permeability.">Role of GTPases in control of microvascular permeability.</a> Cardiovasc. Res. 87, 243-253 (2010).</li><li>Wojciak-Stothard, B., Ridley, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rho+GTPases+and+the+regulation+of+endothelial+permeability.">Rho GTPases and the regulation of endothelial permeability.</a> Vascul. Pharmacol. 39, 187-199 (2002).</li><li>Yuan, S. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Signal+transduction+pathways+in+enhanced+microvascular+permeability.">Signal transduction pathways in enhanced microvascular permeability.</a> Microcirculation. 7, 395-403 (2000).</li><li>Birukov, K. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Small+GTPases+in+mechanosensitive+regulation+of+endothelial+barrier.">Small GTPases in mechanosensitive regulation of endothelial barrier.</a> Microvasc. Res. 77, 46-52 (2009).</li><li>Duran, W. N., Sanchez, F. A., Breslin, J. W., Tuma, R. F., Duran, W. N., Ley, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microcirculatory+Exchange+Function.">Microcirculatory Exchange Function.</a> Handbook of Physiology: Microcirculation. , 81-124 (2008).</li><li>Hu, Y. L., Chien, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamic+motion+of+paxillin+on+actin+filaments+in+living+endothelial+cells.">Dynamic motion of paxillin on actin filaments in living endothelial cells.</a> Biochem. Biophys. Res. Commun. 357, 871-876 (2007).</li><li>Borm, B., Requardt, R. P., Herzog, V., Kirfel, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Membrane+ruffles+in+cell+migration:+indicators+of+inefficient+lamellipodia+adhesion+and+compartments+of+actin+filament+reorganization.">Membrane ruffles in cell migration: indicators of inefficient lamellipodia adhesion and compartments of actin filament reorganization.</a> Exp. Cell. Res. 302, 83-95 (2005).</li><li>Hotulainen, P., Lappalainen, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stress+fibers+are+generated+by+two+distinct+actin+assembly+mechanisms+in+motile+cells.">Stress fibers are generated by two distinct actin assembly mechanisms in motile cells.</a> J. Cell. Biol. 173, 383-394 (2006).</li><li>Pellegrin, S., Mellor, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Actin+stress+fibres.">Actin stress fibres.</a> J. Cell. Sci. 120, 3491-3499 (2007).</li><li>Ballestrem, C., Wehrle-Haller, B., Imhof, B. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Actin+dynamics+in+living+mammalian+cells.">Actin dynamics in living mammalian cells.</a> J. Cell. Sci. 111, 1649-1658 (1998).</li><li>Helmke, B. P., Rosen, A. B., Davies, P. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mapping+mechanical+strain+of+an+endogenous+cytoskeletal+network+in+living+endothelial+cells.">Mapping mechanical strain of an endogenous cytoskeletal network in living endothelial cells.</a> Biophys. J. 84, 2691-2699 (2003).</li><li>Birukova, A. A., Smurova, K., Birukov, K. G., Kaibuchi, K., Garcia, J. G., Verin, A. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+Rho+GTPases+in+thrombin-induced+lung+vascular+endothelial+cells+barrier+dysfunction.">Role of Rho GTPases in thrombin-induced lung vascular endothelial cells barrier dysfunction.</a> Microvasc. Res. 67, 64-77 (2004).</li><li>van Nieuw Amerongen, G. P., van Delft, S., Vermeer, M. A., Collard, J. G., van Hinsbergh, V. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Activation+of+RhoA+by+thrombin+in+endothelial+hyperpermeability:+role+of+Rho+kinase+and+protein+tyrosine+kinases.">Activation of RhoA by thrombin in endothelial hyperpermeability: role of Rho kinase and protein tyrosine kinases.</a> Circ. Res. 87, 335-340 (2000).</li><li>Moy, A. B., Blackwell, K., Kamath, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+effects+of+histamine+and+thrombin+on+endothelial+barrier+function+through+actin-myosin+tension.">Differential effects of histamine and thrombin on endothelial barrier function through actin-myosin tension.</a> Am J Physiol Heart Circ Physiol. 282, H21-H29 (2002).</li><li>Wittman, T., Littlefield, R., Waterman-Storer, C., Goldman, R. D., Spector, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorescent+speckle+microscopy+of+cytoskeletal+dynamics+in+living+cells.">Fluorescent speckle microscopy of cytoskeletal dynamics in living cells.</a> Live Cell Imaging: A Laboratory Manual. , 184-204 (2005).</li><li>Rabut, G., Ellenberg, J., Goldman, R. D., Spector, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photobleaching+techniques+to+study+mobility+and+molecular+dynamics+of+proteins+in+live+cells:+FRAP,+iFRAP,+and+FLIP.">Photobleaching techniques to study mobility and molecular dynamics of proteins in live cells: FRAP, iFRAP, and FLIP.</a> Live Cell Imaging: A Laboratory Manual. , 101-126 (2005).</li></ol>

Nessun conflitto di interessi dichiarati.

L&#39;imaging di GFP-actina in cellule endoteliali consente di vivere una dettagliata analisi delle dinamiche del citoscheletro di actina in risposta a stimoli infiammatori. Questo metodo può essere utile anche a sviluppare i risultati precedenti che mostrano rimodellamento del citoscheletro in risposta a forze fisiche come lo stress di taglio 11. Inoltre, questo metodo permette una valutazione dettagliata del contributo delle dinamiche di actina del citoscheletro a diverse attività delle cellule endoteliali, compresa la migrazione, la mitosi, la formazione di giunzioni intercellulari e maturazione giunzionale, e il mantenimento della funzione di barriera. Nei dati riportati, il comportamento del citoscheletro di actina endoteliali possono essere osservati prima e dopo il trattamento con trombina. Lamellipodia locali tutti lungo i bordi delle cellule endoteliali è stata osservata formazione e regredire nel tempo in monostrati cellulari sia nonconfluent e confluenti. Il trattamento con trombina interrotto brevemente forma lamellipodiazione e fatturato. La trombina anche causato alle cellule di contratto leggermente, in accordo con i rapporti precedenti che lo stress provoca la formazione di trombina in fibra di actina e il rafforzamento dello sviluppo centripeto tensione nelle cellule endoteliali 12-14. Tuttavia, da studi di imaging dal vivo delle cellule di questo tipo, l&#39;origine delle fibre di stress può essere determinato. In HUVEC, la maggior parte delle fibre di stress origine alla periferia delle cellule e fibre assomigliano arco trasversale nella migrazione delle cellule 8, 9. Altro punto di forza di questo metodo rispetto all&#39;uso di cellule fissa è che il numero di fibre di stress può essere quantificato in celle individuali prima e dopo il trattamento trombina, eliminando bias di selezione tra i gruppi sperimentali. Con questo protocollo si valuta il movimento dinamico del bordo delle cellule e le fibre di stress di actina. Per capire le dinamiche monomero di actina in cellule endoteliali, le tecniche più avanzate, come il recupero di fluorescenza dopo photobleaching (FRAP) o fluorescenza speckle microcopia (FSM) può essere applicato 15, 16. Inoltre, poiché cellule endoteliali possono rappresentare un modello migliore della funzione di barriera microvascolare, l&#39;ottimizzazione dei protocolli di trasfezione per esprimere efficacemente GFP-actina in cellule endoteliali rappresenta una direzione logica futuro. In sintesi, l&#39;imaging dal vivo di cellule endoteliali che esprimono GFP-actina rappresenta un potente strumento per determinare come il citoscheletro delle cellule endoteliali risponde a vari tipi di stimoli. Gli studi che utilizzano monostrati endoteliali strettamente confluenti aiuterà a determinare i ruoli delle strutture dinamiche come actina-lamellipodia ricco e trasversale delle fibre arco stress in funzione di barriera endoteliale. Inoltre, l&#39;imaging cellulare dal vivo delle cellule endoteliali che esprimono GFP-actina o altre proteine ​​di fusione che consentono la visualizzazione di altre strutture subcellulari fornirà dettagliate informazioni spazio-temporali necessarie per comprendere i meccanismi di segnalazione e strutturali che determine barriera integrità.

<table border="1"><tbody><tr><td colspan="4"> 1. Suoneria Archivi 5x </td></tr><tr><td> Chimico </td><td> Azienda </td><td> Numero di catalogo </td><td> Quantità </td></tr><tr><td> Cloruro di sodio </td><td> EMD </td><td> SX0420-3 </td><td> 35 g </td></tr><tr><td> Cloruro di potassio </td><td> JT Baker </td><td> 3040 </td><td> 1,75 g </td></tr><tr><td> Cloruro di calcio </td><td> Sigma </td><td> C-3881 </td><td> 1,47 g </td></tr><tr><td> Solfato di Magnesio </td><td> Sigma </td><td> M-9397 </td><td> 1,44 g </td></tr><tr><td> Acqua sterile filtrata </td><td> N / A </td><td> N / A </td><td> Portare a 1 L </td></tr><tr><td colspan="4"> Filtro sterile in bottiglie in autoclave e negozi a 4 ° C </td></tr><tr><td colspan="4"></td></tr><tr><td colspan="4"> 2. MOPS buffer di </td></tr><tr><td> Chimico </td><td>Azienda </td><td> Numero di catalogo </td><td> Quantità </td></tr><tr><td> MOPS </td><td> Sigma </td><td> M3183 </td><td> 125,6 g </td></tr><tr><td> Acqua sterile filtrata </td><td> N / A </td><td> N / A </td><td> Portare a 1 L </td></tr><tr><td colspan="4"> Filtro sterile in bottiglie in autoclave e negozi a 4 ° C </td></tr><tr><td colspan="4"></td></tr><tr><td colspan="4"> 3. Albumina soluzione fisiologica (APSS) </td></tr><tr><td> Chimico </td><td> Azienda </td><td> Numero di catalogo </td><td> Quantità </td></tr><tr><td> Ringer magazzino (5x) </td><td> N / A </td><td> N / A </td><td> 200 mL </td></tr><tr><td> Mops Buffer </td><td> N / A </td><td> N / A </td><td> 5 mL </td></tr><tr><td> Fosfato di sodio </td><td> Sigma </td><td> S-9638 </td><td> 0,168 g </td></tr><tr><td> Piruvato di sodio &lt;/ Td&gt; <td> Sigma </td><td> P5280 </td><td> 0,22 g </td></tr><tr><td> EDTA sale di sodio </td><td> Sigma </td><td> ED2SS </td><td> 0,0074 g </td></tr><tr><td> Glucosio </td><td> Sigma </td><td> G7528 </td><td> 0,901 g </td></tr><tr><td> Albumina, bovina </td><td> USB </td><td> 10856 </td><td> 10 g </td></tr><tr><td> Acqua sterile filtrata </td><td> N / A </td><td> N / A </td><td> Portare a 1 L </td></tr><tr><td colspan="4"> Regolare il pH a 7,4 a 37 ° C, poi filtro sterile in bottiglia in autoclave e conservare a 4 ° C. </td></tr><tr><td colspan="4"></td></tr><tr><td colspan="4"> 4. 0,9% Saline </td></tr><tr><td> Chimico </td><td> Azienda </td><td> Numero di catalogo </td><td> Quantità </td></tr><tr><td> Cloruro di sodio </td><td> EMD </td><td> SX0420-3 </td><td> 9 g </td></tr><tr><td> Acqua sterile filtrata </td><td> N / A </td><td> N / A </td><td> Portare a 1 L </td></tr><tr><td colspan="4"> Filtro sterile in bottiglie in autoclave e negozi a 4 ° C </td></tr><tr><td colspan="4"></td></tr><tr><td colspan="4"> 5. 1,5% Soluzione di gelatina </td></tr><tr><td> Gelatina da pelle del maiale </td><td> Sigma </td><td> G2500 </td><td> 15 g </td></tr><tr><td> 0,9% Saline </td><td> N / A </td><td> N / A </td><td> Portare a 1 L </td></tr><tr><td colspan="4"> Caldo la soluzione a 37 ° C per sciogliere la gelatina a sufficienza. Mentre sono ancora calde, filtro sterile in bottiglie in autoclave e conservare a 4 ° C </td></tr></tbody></table>

study of the actin cytoskeleton in live endothelial cells expressing gfp-actin

L&#39;endotelio microvascolare svolge un ruolo importante come una barriera selettiva permeabile ai fluidi e soluti. Le giunzioni adesive tra cellule endoteliali regolano la permeabilità dell&#39;endotelio, e molti studi hanno indicato l&#39;importante contributo del citoscheletro a determinare l&#39;integrità giunzionale 1-5. Una cintura di actina corticale è pensato per essere importante per il mantenimento di stabili svincoli 1, 2, 4, 5. Al contrario, lo stress delle fibre di actina sono pensati per generare tensione centripeta all&#39;interno delle cellule endoteliali che indebolisce giunzioni 2-5. Gran parte di questa teoria si è basata su studi in cui sono trattate le cellule endoteliali con i mediatori infiammatori noti per aumentare la permeabilità endoteliale, e poi fissare le cellule e l&#39;etichettatura di F-actina per l&#39;osservazione microscopica. Tuttavia, questi studi forniscono una comprensione molto limitata del ruolo del citoscheletro delle cellule perché le immagini fisse fornire istantanee solo neltempo con nessuna informazione sulla dinamica delle strutture actina 5. Live-cell imaging consente l&#39;incorporazione della natura dinamica del citoscheletro di actina in studio dei meccanismi per determinare l&#39;integrità endoteliale barriera. Uno dei principali vantaggi di questo metodo è che l&#39;impatto di vari stimoli infiammatori sulle strutture di actina in cellule endoteliali può essere valutata alla stessa serie di cellule viventi, prima e dopo il trattamento, eliminando potenziali bias che possono verificarsi quando si osservano campioni fissati. Cellule endoteliali della vena ombelicale (HUVEC) sono transfettate con un GFP-β-actina plasmide e cresciuto fino a confluenza su lamelle di vetro. Time-lapse immagini di GFP-actina in HUVEC confluenti vengono catturati prima e dopo l&#39;aggiunta di mediatori infiammatori che provocano tempo-dipendente cambiamenti nella integrità barriera endoteliale. Questi studi consentono l&#39;osservazione visuale della sequenza fluida di cambiamenti nel citoscheletro di actina che contribuiscono a endotelil interruzione barriera e restauro. I nostri risultati dimostrano costantemente locali, ricche di actina formazione lamellipodia e fatturato in cellule endoteliali. La formazione e la circolazione delle fibre di actina lo stress può anche essere osservato. L&#39;analisi della frequenza di formazione e di fatturato del locale lamellipodia, prima e dopo il trattamento con stimoli infiammatori possono essere documentate da analisi chimografo. Questi studi forniscono informazioni importanti sulla natura dinamica del citoscheletro di actina in cellule endoteliali che può essere usato per scoprire i meccanismi molecolari precedentemente identificati importante per il mantenimento dell&#39;integrità della barriera endoteliale.

Watch this Scientific Journal Video about Study of the Actin Cytoskeleton in Live Endothelial Cells Expressing GFP-Actin at JoVE.com

Study of the Actin Cytoskeleton in Live Endothelial Cells Expressing GFP-Actin

Immagini microscopiche dal vivo di cellule endoteliali che esprimono GFP-actina permette la caratterizzazione dei cambiamenti dinamici nelle strutture del citoscheletro. A differenza delle tecniche che utilizzano campioni fissati, questo metodo fornisce una valutazione dettagliata delle variazioni temporali del citoscheletro di actina nelle cellule stesse prima, durante e dopo vari stimoli fisici, farmacologici o infiammatoria.

Studio del citoscheletro di actina in vivo le cellule endoteliali Esprimendo GFP-Actina

The microvascular endothelium plays an important role as a selectively permeable barrier to fluids and solutes. The adhesive junctions between endothelial ...

study-actin-cytoskeleton-live-endothelial-cells-expressing-gfp

Research

Education

JoVE Journal

JoVE Core

Cell Biology

Biology

Unit 1

The Cytoskeleton I: Actin and Microfilaments

SCIENTISTS IN ACTION

27.0K Views.  Louisiana State University Health Sciences Center. Immagini microscopiche dal vivo di cellule endoteliali che esprimono GFP-actina permette la caratterizzazione dei cambiamenti dinamici nelle strutture del citoscheletro. A differenza delle tecniche che utilizzano campioni fissati, questo metodo fornisce una valutazione dettagliata delle variazioni temporali del citoscheletro di actina nelle cellule stesse prima, durante e dopo vari stimoli fisici, farmacologici o infiammatoria.

Video: Study of the Actin Cytoskeleton in Live Endothelial Cells Expressing GFP-Actin

Testing Visual Sensitivity to the Speed and Direction of Motion in Lizards

Testing visual sensitivity in any species provides basic information regarding behaviour, evolution, and ecology. However, testing specific features of the visual system provide more empirical evidence for functional applications. Investigation into the sensory system provides information about the sensory capacity, learning and memory ability, and establishes known baseline behaviour in which to gauge deviations (Burghardt, 1977). However, unlike mammalian or avian systems, testing for learning and memory in a reptile species is difficult. Furthermore, using an operant paradigm as a psychophysical measure of sensory ability is likewise as difficult. Historically, reptilian species have responded poorly to conditioning trials because of issues related to motivation, physiology, metabolism, and basic biological characteristics. Here, I demonstrate an operant paradigm used a novel model lizard species, the Jacky dragon (Amphibolurus muricatus) and describe how to test peripheral sensitivity to salient speed and motion characteristics. This method uses an innovative approach to assessing learning and sensory capacity in lizards. I employ the use of random-dot kinematograms (RDKs) to measure sensitivity to speed, and manipulate the level of signal strength by changing the proportion of dots moving in a coherent direction. RDKs do not represent a biologically meaningful stimulus, engages the visual system, and is a classic psychophysical tool used to measure sensitivity in humans and other animals. Here, RDKs are displayed to lizards using three video playback systems. Lizards are to select the direction (left or right) in which they perceive dots to be moving. Selection of the appropriate direction is reinforced by biologically important prey stimuli, simulated by computer-animated invertebrates.

Testing visual sensitivity in lizards using an operant conditioning paradigm that employs video playback of random-dot kinematograms and computer-generated invertebrates.

Test di sensibilità visiva alla velocità e direzione del movimento in lucertole

Testing visual sensitivity in any species provides basic information regarding behaviour, evolution, and ecology. However, testing specific features of ...

Ricerca

Biologia

Live Cell Imaging of F-actin Dynamics via Fluorescent Speckle Microscopy (FSM)

In this protocol we describe the use of Fluorescent Speckle Microscopy (FSM) to capture high-resolution images of actin dynamics in PtK1 cells. A unique advantage of FSM is its ability to capture the movement and turnover kinetics (assembly/disassembly) of the F-actin network within living cells. This technique is particularly useful in deriving quantitative measurements of F-actin dynamics when paired with computer vision software (qFSM).  We describe  the selection, microinjection and visualization of fluorescent actin probes in living cells. Importantly, similar procedures are applicable to visualizing other macomolecular assemblies. FSM has been demonstrated for microtubules, intermediate filaments, and adhesion complexes.  

Live Cell Imaging of F-actin Dynamics via Fluorescent Speckle Microscopy FSM

Selection, microinjection, and imaging of fluorescently-labeled F-actin via fluorescent speckle microscopy (FSM).

Imaging cellulare dal vivo di F-actina Dynamics tramite microscopia a fluorescenza Speckle (FSM)

In this protocol we describe the use of Fluorescent Speckle Microscopy (FSM) to capture high-resolution images of actin dynamics in PtK1 cells. A unique ...

Live Imaging of Cell Motility and Actin Cytoskeleton of Individual Neurons and Neural Crest Cells in Zebrafish Embryos

The zebrafish is an ideal model for imaging cell behaviors during development in vivo. Zebrafish embryos are externally fertilized and thus easily accessible at all stages of development. Moreover, their optical clarity allows high resolution imaging of cell and molecular dynamics in the natural environment of the intact embryo. We are using a live imaging approach to analyze cell behaviors during neural crest cell migration and the outgrowth and guidance of neuronal axons.
Live imaging is particularly useful for understanding mechanisms that regulate cell motility processes. To visualize details of cell motility, such as protrusive activity and molecular dynamics, it is advantageous to label individual cells. In zebrafish, plasmid DNA injection yields a transient mosaic expression pattern and offers distinct benefits over other cell labeling methods. For example, transgenic lines often label entire cell populations and thus may obscure visualization of the fine protrusions (or changes in molecular distribution) in a single cell. In addition, injection of DNA at the one-cell stage is less invasive and more precise than dye injections at later stages.
Here we describe a method for labeling individual developing neurons or neural crest cells and imaging their behavior in vivo. We inject plasmid DNA into 1-cell stage embryos, which results in mosaic transgene expression. The vectors contain cell-specific promoters that drive expression of a gene of interest in a subset of sensory neurons or neural crest cells. We provide examples of cells labeled with membrane targeted GFP or with a biosensor probe that allows visualization of F-actin in living cells1.
Erica Andersen, Namrata Asuri, and Matthew Clay contributed equally to this work.

This protocol describes imaging of individual neurons or neural crest cells in living zebrafish embryos. This method is used to examine cellular behaviors and actin localization using fluorescence confocal time-lapse microscopy.

Immagini dal vivo della motilità cellulare e citoscheletro dei singoli neuroni e cellule della cresta neurale in embrioni di zebrafish

The zebrafish is an ideal model for imaging cell behaviors during development in vivo. Zebrafish embryos are externally fertilized and thus easily ...

Transplantation of GFP-expressing Blastomeres for Live Imaging of Retinal and Brain Development in Chimeric Zebrafish Embryos

Cells change extensively in their locations and property during embryogenesis. These changes are regulated by the interactions between the cells and their environment. Chimeric embryos, which are composed of cells of different genetic background, are great tools to study the cell-cell interactions mediated by genes of interest. The embryonic transparency of zebrafish at early developmental stages permits direct visualization of the morphogenesis of tissues and organs at the cellular level. Here, we demonstrate a protocol to generate chimeric retinas and brains in zebrafish embryos and to perform live imaging of the donor cells. The protocol covers the preparation of transplantation needles, the transplantation of GFP-expressing donor blastomeres to GFP-negative hosts, and the examination of donor cell behavior under live confocal microscopy. With slight modifications, this protocol can also be used to study the embryonic development of other tissues and organs in zebrafish. The advantages of using GFP to label donor cells are also discussed. 

We demonstrate a protocol to generate chimeric zebrafish embryos for live imaging cellular behavior during embryogenesis.

Il trapianto di GFP che esprimono blastomeri per dell&#39;immagine in tempo reale dello sviluppo della retina e del cervello in embrioni di zebrafish Chimerico

Cells change extensively in their locations and property during embryogenesis. These changes are regulated by the interactions between the cells and their ...

Do-It-Yourself Device for Recovery of Cryopreserved Samples Accidentally Dropped into Cryogenic Storage Tanks

Liquid nitrogen is colorless, odorless, extremely cold (-196 &deg;C) liquid kept under pressure. It is commonly used as a cryogenic fluid for long term storage of biological materials such as blood, cells and tissues 1,2. The cryogenic nature of liquid nitrogen, while ideal for sample preservation, can cause rapid freezing of live tissues on contact - known as 'cryogenic burn'2, which may lead to severe frostbite in persons closely involved in storage and retrieval of samples from Dewars. Additionally, as liquid nitrogen evaporates it reduces the oxygen concentration in the air and might cause asphyxia, especially in confined spaces2.
In laboratories, biological samples are often stored in cryovials or cryoboxes stacked in stainless steel racks within the Dewar tanks1. These storage racks are provided with a long shaft to prevent boxes from slipping out from the racks and into the bottom of Dewars during routine handling. All too often, however, boxes or vials with precious samples slip out and sink to the bottom of liquid nitrogen filled tank. In such cases, samples could be tediously retrieved after transferring the liquid nitrogen into a spare container or discarding it. The boxes and vials can then be relatively safely recovered from emptied Dewar. However, the cryogenic nature of liquid nitrogen and its expansion rate makes sunken sample retrieval hazardous. It is commonly recommended by Safety Offices that sample retrieval be never carried out by a single person. Another alternative is to use commercially available cool grabbers or tongs to pull out the vials3. However, limited visibility within the dark liquid filled Dewars poses a major limitation in their use.
In this article, we describe the construction of a Cryotolerant DIY retrieval device, which makes sample retrieval from Dewar containing cryogenic fluids both safe and easy.

Here we present a low cost, durable cryotolerant device for sample retrieval from Dewar tanks filled with liquid nitrogen. The ease of construction and modular design of the device makes the process of sample retrieval from cryogenic tanks safe and easy.

Do-It-Yourself dispositivo per il recupero di campioni crioconservati cadere accidentalmente nelle cisterne criogeniche

Liquid nitrogen is colorless, odorless, extremely cold (-196 &deg;C) liquid kept under pressure. It is commonly used as a cryogenic fluid for long term ...

Live Imaging of Apoptotic Cell Clearance during Drosophila Embryogenesis

The proper elimination of unwanted or aberrant cells through apoptosis and subsequent phagocytosis (apoptotic cell clearance) is crucial for normal development in all metazoan organisms. Apoptotic cell clearance is a highly dynamic process intimately associated with cell death; unengulfed apoptotic cells are barely seen in vivo under normal conditions. In order to understand the different steps of apoptotic cell clearance and to compare 'professional' phagocytes - macrophages and dendritic cells to 'non-professional' - tissue-resident neighboring cells, in vivo live imaging of the process is extremely valuable. Here we describe a protocol for studying apoptotic cell clearance in live Drosophila embryos. To follow the dynamics of different steps in phagocytosis we use specific markers for apoptotic cells and phagocytes. In addition, we can monitor two phagocyte systems in parallel: 'professional' macrophages and 'semi-professional' glia in the developing central nervous system (CNS). The method described here employs the Drosophila embryo as an excellent model for real time studies of apoptotic cell clearance.

Live Imaging of Apoptotic Cell Clearance during Drosophila Embryogenesis

Here we describe an effective method for studying dynamics of apoptotic cell clearance in vivo. This method employs live Drosophila embryos as a powerful model for monitoring phagocytosis of apoptotic cells using specific labeling of apoptotic cells and phagocytes.

Vivere Imaging di apoptotica delle cellule libera nel corso<em&gt; Drosophila</em&gt; Embriogenesi

The  proper elimination of unwanted or aberrant cells through apoptosis and  subsequent phagocytosis (apoptotic cell clearance) is crucial for normal  ...

Intravital Microscopy for Imaging Subcellular Structures in Live Mice Expressing Fluorescent Proteins

Here we describe a procedure to image subcellular structures in live rodents that is based on the use of confocal intravital microscopy. As a model organ, we use the salivary glands of live mice since they provide several advantages. First, they can be easily exposed to enable access to the optics, and stabilized to facilitate the reduction of the motion artifacts due to heartbeat and respiration. This significantly facilitates imaging and tracking small subcellular structures. Second, most of the cell populations of the salivary glands are accessible from the surface of the organ. This permits the use of confocal microscopy that has a higher spatial resolution than other techniques that have been used for in vivo imaging, such as two-photon microscopy. Finally, salivary glands can be easily manipulated pharmacologically and genetically, thus providing a robust system to investigate biological processes at a molecular level.
In this study we focus on a protocol designed to follow the kinetics of the exocytosis of secretory granules in acinar cells and the dynamics of the apical plasma membrane where the secretory granules fuse upon stimulation of the beta-adrenergic receptors. Specifically, we used a transgenic mouse that co-expresses cytosolic GFP and a membrane-targeted peptide fused with the fluorescent protein tandem-Tomato. However, the procedures that we used to stabilize and image the salivary glands can be extended to other mouse models and coupled to other approaches to label in vivo cellular components, enabling the visualization of various subcellular structures, such as endosomes, lysosomes, mitochondria, and the actin cytoskeleton.

Intravital microscopy is a powerful tool that enables imaging various biological processes in live animals. In this article, we present a detailed method for imaging the dynamics of subcellular structures, such as the secretory granules, in the salivary glands of live mice.

Intravitale Microscopia per le strutture Imaging subcellulari in topi vivi Esprimere proteine ​​fluorescenti

Here we describe a procedure to image subcellular structures in live rodents that is based on the use of confocal intravital microscopy. As a model organ, ...

Endothelial Cell Tube Formation Assay for the In Vitro Study of Angiogenesis

Angiogenesis is a vital process for normal tissue development and wound healing, but is also associated with a variety of pathological conditions. Using this protocol, angiogenesis may be measured in vitro in a fast, quantifiable manner. Primary or immortalized endothelial cells are mixed with conditioned media and plated on basement membrane matrix. The endothelial cells form capillary like structures in response to angiogenic signals found in conditioned media. The tube formation occurs quickly with endothelial cells beginning to align themselves within 1&#160;hr and lumen-containing tubules beginning to appear within 2 hr. Tubes can be visualized using a phase contrast inverted microscope, or the cells can be treated with calcein AM prior to the assay and tubes visualized through fluorescence or confocal microscopy. The number of branch sites/nodes, loops/meshes, or number or length of tubes formed can be easily quantified as a measure of in vitro angiogenesis. In summary, this assay can be used to identify genes and pathways that are involved in the promotion or inhibition of angiogenesis in a rapid, reproducible, and quantitative manner.

Endothelial Cell Tube Formation Assay for the In Vitro Study of Angiogenesis

The tube formation assay is a fast, quantifiable method for measuring in vitro angiogenesis. Endothelial cells are combined with conditioned media and plated on basement membrane extract. Tube formation occurs within hours and newly formed tubules easily quantified.

Endoteliali Tubo cellulare saggio Formazione per la<em&gt; In Vitro</em&gt; Studio di Angiogenesi

Angiogenesis is a vital process for normal tissue development and wound healing, but is also associated with a variety of pathological conditions. Using ...

Isolation of Murine Valve Endothelial Cells

Normal valve structures consist of stratified layers of specialized extracellular matrix (ECM) interspersed with valve interstitial cells (VICs) and surrounded by a monolayer of valve endothelial cells (VECs). VECs play essential roles in establishing the valve structures during embryonic development, and are important for maintaining life-long valve integrity and function. In contrast to a continuous endothelium over the surface of healthy valve leaflets, VEC disruption is commonly observed in malfunctioning valves and is associated with pathological processes that promote valve disease and dysfunction. Despite the clinical relevance, focused studies determining the contribution of VECs to development and disease processes are limited. The isolation of VECs from animal models would allow for cell-specific experimentation. VECs have been isolated from large animal adult models but due to their small population size, fragileness, and lack of specific markers, no reports of VEC isolations in embryos or adult small animal models have been reported. Here we describe a novel method that allows for the direct isolation of VECs from mice at embryonic and adult stages. Utilizing the Tie2-GFP reporter model that labels all endothelial cells with Green Fluorescent Protein (GFP), we have been successful in isolating GFP-positive (and negative) cells from the semilunar and atrioventricular valve regions using fluorescence activated cell sorting (FACS). Isolated GFP-positive VECs are enriched for endothelial markers, including CD31 and von Willebrand Factor (vWF), and retain endothelial cell expression when cultured; while, GFP-negative cells exhibit molecular profiles and cell shapes consistent with VIC phenotypes. The ability to isolate embryonic and adult murine VECs allows for previously unattainable molecular and functional studies to be carried out on a specific valve cell population, which will greatly improve our understanding of valve development and disease mechanisms.

The ability to isolate heart valve endothelial cells (VECs) is critical for understanding mechanisms of valve development, maintenance, and disease. Here we describe the isolation of VECs from embryonic and adult Tie2-GFP mice using FACS that will allow for studies determining the contribution of VECs in developmental and disease processes.

Isolamento di cellule murine endoteliali Valve

Normal valve structures consist of stratified layers of specialized extracellular matrix (ECM) interspersed with valve interstitial cells (VICs) and ...

High-resolution Time-lapse Imaging and Automated Analysis of Microtubule Dynamics in Living Human Umbilical Vein Endothelial Cells

The physiological process by which new vasculature forms from existing vasculature requires specific signaling events that trigger morphological changes within individual endothelial cells (ECs). These processes are critical for homeostatic maintenance such as wound healing, and are also crucial in promoting tumor growth and metastasis. EC morphology is defined by the organization of the cytoskeleton, a tightly regulated system of actin and microtubule (MT) dynamics that is known to control EC branching, polarity and directional migration, essential components of angiogenesis. To study MT dynamics, we used high-resolution fluorescence microscopy coupled with computational image analysis of fluorescently-labeled MT plus-ends to investigate MT growth dynamics and the regulation of EC branching morphology and directional migration. Time-lapse imaging of living Human Umbilical Vein Endothelial Cells (HUVECs) was performed following transfection with fluorescently-labeled MT End Binding protein 3 (EB3) and Mitotic Centromere Associated Kinesin (MCAK)-specific cDNA constructs to evaluate effects on MT dynamics. PlusTipTracker software was used to track EB3-labeled MT plus ends in order to measure MT growth speeds and MT growth lifetimes in time-lapse images. This methodology allows for the study of MT dynamics and the identification of how localized regulation of MT dynamics within sub-cellular regions contributes to the angiogenic processes of EC branching and migration.

Protocols for Human Umbilical Vein Endothelial Cell (HUVEC) culture, transient transfection of fluorescently-labeled markers of microtubule growth, live-cell imaging and automated analysis of interphase microtubule growth dynamics are detailed.

Ad alta risoluzione Time-lapse imaging e analisi automatizzata dei microtubuli Dynamics in Living ombelicale umano cellule endoteliali Vena

The physiological process by which new vasculature forms from existing vasculature requires specific signaling events that trigger morphological changes ...

Methods Article

Studio del citoscheletro di actina in vivo le cellule endoteliali Esprimendo GFP-Actina