Diese Arbeit wurde durch Forschungsstipendien (NRF-2018-R1D1A1B07050175, HURF-2017-66) der National Research Foundation (NRF) korea und hallym University Research Fund unterstützt.

Alle Forschungsprotokolle mit ICR-Mäusen wurden vom Institutional Animal Care and Use Committee (IACUC) der Yonsei University am Wonju College of Medicine genehmigt. Die Experimente wurden nach dem Ethikkodex der World Medical Association durchgeführt. In diesem Protokoll wurden schwangere ICR-Mäuse in einem 12/12 h Licht/Dunkel-Zyklus mit freiem Zugang zu Nahrung und Wasser gehalten.
1. Cochlea-Sektion
<ol><li>Sterilisieren Sie die laminare Strömungsgewebekulturhaube, indem Sie das ultraviolette Licht für 30 min einschalten, und sprühen Sie alle Oberflächen vor der Anwendung mit 70% Ethanol. Lassen Sie die Oberflächen trocknen.</li>
	<li>Sezierinstrumente in 70% Ethanol für 10 min legen und vor der Verwendung trocknen.</li>
	<li>Verwenden Sie eine Operationsklinge, um postnatale 3-4 Tage alte Mäuse zu enthaupten (Abbildung 2A).</li>
	<li>Legen Sie den Schädel unter ein Stereomikroskop in die laminare Strömungshaube und tränken Sie das Gewebe in 70% Ethanol.</li>
	<li>Das Gewebe in einer Gewebesektionslösung (1x Hank es Balanced Salt Solution, 1 mM HEPES) schnell einweichen, um das Ethanol zu entfernen.</li>
	<li>Schneiden Sie die Mittellinie des Schädels mit einer chirurgischen Klinge (Abbildung 2B,C).</li>
	<li>Setzen Sie den Schädel aus, indem Sie die Haut vordergründ herunterziehen und den äußeren Gehörgang des Ohres schneiden (Abbildung 2D).</li>
	<li>Schneiden Sie vom vorderen zum hinteren Teil des Schädels über die Augenlinie (Abbildung 2E).</li>
	<li>Öffnen Sie den Schädel und entfernen Sie vordem, Kleinhirn und Hirnstamm mit stumpfer Zange (Abbildung 2F,G).</li>
	<li>Mit Mikrozangen, trennen Sie die Cochlea vom temporalen Knochen (Abbildung 2H).</li>
	<li>Übertragen Sie die Cochleae in eine Petrischale, die eine Gewebesektionslösung enthält.</li>
	<li>Sezieren Sie sorgfältig die gesamte Cochlea-Otikkapsel, so dass nur das interne Cochlea-Weichgewebe übrig bleibt (Abbildung 2I,J).</li>
	<li>Halten Sie den Modiolus der Cochleae mit Zangen und den Cochlea-Kanal mit einem weiteren Zangenpaar und trennen Sie langsam die beiden Gewebe (Abbildung 2K).</li>
	<li>Entfernen Sie die Stria vascularis und die tektoriale Membran, indem Sie sie vorsichtig abschälen (Abbildung 2L,M).</li>
	<li>Legen Sie einen sterilisierten Kunststoffdeckel in eine neue Gewebedissektionslösung und legen Sie dann das Organ von Corti auf einen Abdeckzettel von 9 mm Durchmesser, um sicherzustellen, dass die Basilarmembran nach unten zeigt (Abbildung 2N-P).</li>
	<li>Immobilisieren Sie das Gewebe, indem Sie die Reissner-Membran und das verbleibende Modiolusgewebe mit Zangen auf den Deckelschlupf drücken (Abbildung 2N-P).</li>
	<li>Übertragen Sie den Deckelrutsch mit dem eingebetteten Gewebe in die Mitte einer konfokalen Schale mit 35 mm Durchmesser.</li>
	<li>Legen Sie den Glasklonzylinder auf die Schale, mit dem Cochlea-Explant in der Mitte der Schale positioniert, und fügen Sie 100 L Explant Culture Medium (DMEM/F12, 10% fetales Rinderserum (FBS), 1% N2-Ergänzung, Ampicillin (10 g/ml))10 in den Zylinder(Abbildung 2Q).</li>
	<li>Platte 5 × 103 Zellen des aus der Maus knochenknochenförmigen grünen Fluoreszenzproteins (GFP) getaggten MSCs in 2 ml Kulturmedium (45% DMEM + 45% DMEM/F12, 10% FBS, 1% N2-Ergänzung, 10 g/ml Ampicillin) außerhalb des Glaszylinders(Abbildung 2R).<ol>
<li>Wenn die MSCs 80-90% konfluent sind, durchtrennen Sie sie, indem Sie sie mit Trypsin-Ethylendiamin-Tetraessigsäure lösen.</li>
	</ol>
</li>
	<li>Die konfokale Schale vorsichtig in einen befeuchteten Inkubator geben und bei 37 °C in einer 5%CO2-Atmosphäre über Nacht bebrüten.</li>
	<li>Alle Mittleren innerhalb und außerhalb des Zylinders ansaugen und dann den Glaszylinder aus der konfokalen Schale entfernen.</li>
	<li>Fügen Sie dem konfokalen Gericht 2 ml frisches Kulturmedium hinzu und brüten Sie das Gewebekulturgericht in einem befeuchteten Inkubator, bis es zur Analyse bereit ist.</li>
</ol><img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/61947/61947fig2v2.jpg"> Abbildung 2. Zerlegung einer Maus-Cochlea und Kokultur des Organs von Corti und MSCs. (A) Enthauptung der Maus, (B) und (C) Mittellinie sagittale Zerlegung des Kopfes, (D) und (E) koronale Zerlegung des Gehirns, (F) und (G) Entfernung des Gehirns und des Temporalknochens, (H) die Cochlea, (I) Entfernung der knöchernen Cochlea-Wand, (J) Isolierung der Cochlea, (K) Trennung des Cochlea-Kanals (L) Trennung von Stria vascularis (SV) und Spiralband (SL) vom Organ von Corti, (M) Entfernung der tektorialen Membran, (N-P) Fixierung der Cochlea auf einem Kunststoffdeckel, (Q) Lage des Deckel- und Glaszylinders in der konfokalen Schale, (R) Inokulation von MSCs. Weiße Skala bar (A-E) = 1 cm; orange (F, G, P) und gelber Skalenbalken (H,I) = 1 mm; Grüne Skala (J-O) = 0,5 mm. Bitte klicken <a href="https://www.jove.com/files/ftp_upload/61947/61947fig2v2large.jpg" target="_blank">Sie hier, um eine größere Version dieser Abbildung anzuzeigen.</a>
2. Zeitraffer-Bildgebung
<ol><li>Verwenden Sie für die hier vorgestellten Experimente ein konfokales Mikroskopiesystem mit einem Bühnen-Inkubator-System.</li>
	<li>Schalten Sie das konfokale Mikroskop, das Fluoreszenzlicht und den Computer ein.</li>
	<li>Stellen Sie die Bedingungen des Bühneninkubators auf der Bühne des konfokalen Mikroskops auf 37 °C und 5%CO2-Atmosphäre.</li>
	<li>Legen Sie die Probenschale auf das Tellerbefestigungsgefäß, decken Sie sie mit dem Tellerbefestigungsdeckel ab und schließen Sie die Kammer mit dem oberen Heizdeckel.</li>
	<li>Passen Sie den Zoom und Fokus an, um das Organ von Corti und MSCs im Sichtfeld zu lokalisieren.</li>
	<li>Öffnen Sie die Bildverarbeitungssoftware. Wählen Sie unter der Option Suchen ein 20-faches Plan-Apochromat-Objektiv (numerische Blende 0,8) und eine 0,5-fache Anbauflächeaus.</li>
	<li>Klicken Sie unter Akquisitionauf Smart Setup und wählen Sie EGFP.</li>
	<li>Öffnen Sie die Kanal-Registerkarte unter Anschaffung, und stellen Sie die Laserleistung auf 0,2%, das Loch auf 44 m, die Master-Verstärkung auf 750 Vund die digitale Verstärkung auf 1,0.</li>
	<li>Klicken Sie auf ESID unter Imaging-Setup, und stellen Sie die ESID-Verstärkung auf 4 und die digitale Verstärkung auf 7.5.</li>
	<li>Klicken Sie auf Fliesen und Pfahl, um 210 Fliesen zu produzieren.</li>
	<li>Öffnen Sie die Focus-Strategie und wählen Sie den Fokusmodusaus.</li>
	<li>Legen Sie unter Zeitreihendie Dauer auf 24 h und das Intervall auf 10 minfest.</li>
	<li>Legen Sie unter Aufnahmedie Framegröße auf 512 x 512 Pixel, die Scangeschwindigkeit auf 8, die Richtung auf bidirektional,die Mittelung auf 4xund die Bits pro Pixel auf 16fest.</li>
	<li>Klicken Sie auf Experiment starten, um das Experiment zu starten.</li>
</ol>3. Bilddatei-Änderung
<ol><li>Klicken Sie unter Verarbeitungauf Heften, und legen Sie die minimale Überlagerung auf 5 % und die maximale Verschiebung auf 10 %fest.</li>
	<li>Klicken Sie auf Filmexport, setzen Sie unkomprimiert, und stellen Sie die Geschwindigkeit auf 7.5.</li>
</ol>4. Immunostaining
<ol><li>Das Medium vorsichtig ansaugen und die Probe zweimal mit phosphatgepufferter Saline (PBS) 5 min waschen.</li>
	<li>Fixieren Sie die Probe mit 4% Formalin in PBS für 15 min, und waschen Sie die Probe 3 mal mit PBS für 5 min.</li>
	<li>Permeabilisieren Sie die Probe in 0,1% Triton X-100 in PBS für 10 min, und waschen Sie 3 mal mit PBS für 5 min.</li>
	<li>Fügen Sie 250 L Phalloidin-iFluor 647 Reagenz (1:1000 Verdünnung in PBS) hinzu und inkubieren Sie die Probe für 1 h bei Raumtemperatur auf dem Shaker.</li>
	<li>Waschen Sie die Probe 3 mal mit PBS für 5 min.</li>
	<li>Übertragen Sie den Deckelrutsch auf den Glasschlitten und fügen Sie 2 Tropfen Montagelösung hinzu.</li>
	<li>Legen Sie einen Deckelzettel vorsichtig auf die Folie.</li>
	<li>Versiegeln Sie den Deckelrutsch mit klarem Nagellack und lagern Sie bei 4 °C im Dunkeln, bis Zellen beobachtet werden.</li>
	<li>Stellen Sie den Dia mit einem konfokalen Mikroskop mit einem geeigneten Filter bei Anregung/Emission (Ex/Em)=650/665 nm für Phalloidin und bei Ex/Em=488/507 nm für EGFP auf.</li>
</ol>

<ol>
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Die Autoren haben nichts zu verraten.

Die Transplantation von MSCs an beschädigten Stellen zur Förderung der Regeneration geschädigter Zellen wurde ausgiebig untersucht, und die therapeutische Wirkung ist offensichtlich. Die Transplantation und die anschließende Differenzierung von MSCs wurden berichtet, um das Gehör bei Ratten mit Hörverlust durch 3-Nitropropionsäure13induziert wiederherzustellen. Obwohl Lee et al. MSCs auf Menschen transvenös anwendeten, erreichten sie keine signifikante Verbesserung im Hören<sup class="xre...

Hörverlust kann angeboren auftreten oder kann schrittweise durch mehrere Faktoren verursacht werden, einschließlich Alterung, Medikamente, und Lärm. Hörverlust ist oft schwierig zu behandeln, weil es sehr schwierig ist, beeinträchtigte Funktion wiederherzustellen, sobald die für das Gehör verantwortlichen Haarzellen geschädigt sind1. Nach Angaben der Weltgesundheitsorganisation leiden weltweit schätzungsweise 461 Millionen Menschen an Hörverlust, was 6,1 % der Weltbevölkerung ausmacht. Von den Menschen mit Hörverlust sind 93 % Erwachsene und 7 % Kinder.
Es wurde versucht, eine Reihe von Ansätzen zur Behandlung von Hörverlust zu finden; insbesondere hat sich ein Regenerationsansatz mit MsC als vielversprechende Behandlung herausgestellt. Wenn Gewebe geschädigt ist, werden MSCs natürlicherweise in das Kreislaufsystem freigesetzt und wandern an die Verletzungsstelle, wo sie verschiedene Moleküle absondern, um eine Mikroumgebung zu bilden, die die Regeneration fördert2. Daher ist es wichtig, eine Methode zur Behandlung von geschädigtem Gewebe durch die Migration von extern implantierten MSCs auf Zielorgane und deren anschließende Sekretion von Molekülen zu entwickeln, die eine starke Immunregulation, Angiogenese und Anti-Apoptose verursachen, um die Wiederherstellung der beschädigten Zellfunktion3,4,5zu verbessern.
Der Homing-Prozess, bei dem MSCs in beschädigte Gewebe migrieren, könnte das wichtigste Hindernis sein, das überwunden werden muss. MSCs verfügen über einen systemischen Homing-Mechanismus mit sequenziellen Schritten des Tethering/Rollings, der Aktivierung, des Arrests, der Transmigration/Diapedese und der Migration6,7,8. Derzeit werden Anstrengungen unternommen, um Wege zur Verbesserung dieser Schritte zu finden. Verschiedene Strategien, einschließlich genetischer Veränderung, Zelloberflächentechnik, In-vitro-Primierung und magnetische Rführung, wurden getestet6,7. Darüber hinaus wurden mehrere Versuche unternommen, den Schutz und die Regeneration von auditiven Haarzellen zu fördern, indem MSCs an die Stelle der beschädigten Cochlea homing. Die Verfolgung von MSCs in vivo ist jedoch zeitaufwändig und arbeitsintensiv und erfordert hochspezialisierte Fähigkeiten9.
Um dieses Problem zu lösen, wurde eine Methode entwickelt, um das Homing von MSCs in der Cochlea durch zeitraffende konfokale Mikroskopie zu beobachten, die die Migration von Zellen über mehrere Stunden fotografiert(Abbildung 1). Es wurde im frühen20. Jahrhundert entwickelt und hat sich vor kurzem zu einem leistungsfähigen Werkzeug für die Untersuchung der Migration von bestimmten Zellen.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/61947/61947fig01.jpg" style="font-size: 14px;"> Abbildung 1: Grafische Zusammenfassung. (A) Nachdem das sezierte Organ von Corti mit Zangen auf einem Kunststoffdeckel aufeinem Kunststoffdeckel aufkleben wird, wird der Deckelaufschub auf eine 35 mm Glasboden-Konfokalmikroskopische Schale gelegt, und (B) wird der Glaszylinder positioniert. (C) Nach dem Befüllen der Innenseite des Glaszylinders mit Medium(D) werden GFP-beschriftete MSCs mit Medium sorgfältig außerhalb des Zylinders hinzugefügt. (E) Nach der Inkubation über Nacht (F) wird der Glaszylinder entfernt und Die Bilder werden mit einem konfokalen Mikroskop aufgenommen. Abkürzungen: GFP = grünes fluoreszierendes Protein; MSCs = mesenchymale Stammzellen. <a href="https://www.jove.com/files/ftp_upload/61947/61947fig01large.jpg" style="font-size: 14px;" target="_blank">Bitte klicken Sie hier, um eine größere Version dieser Abbildung anzuzeigen.</a>

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>10X PBS Buffer</td>
			<td>GenDEPOT</td>
			<td>P2100-104</td>
			<td></td>
		</tr>
		<tr>
			<td>4% Formalin</td>
			<td>T&#38;I</td>
			<td>BPP-9004</td>
			<td></td>
		</tr>
		<tr>
			<td>Ampicillin</td>
			<td>sigma&#160;</td>
			<td>A5354-10ml</td>
			<td></td>
		</tr>
		<tr>
			<td>BSA</td>
			<td>sigma&#160;</td>
			<td>A4503-100G</td>
			<td></td>
		</tr>
		<tr>
			<td>confocal dish</td>
			<td>SPL</td>
			<td>200350</td>
			<td></td>
		</tr>
		<tr>
			<td>confocal microscope&#160;</td>
			<td>ZEISS</td>
			<td>LSM800</td>
			<td></td>
		</tr>
		<tr>
			<td>coverslip</td>
			<td>SPL</td>
			<td>20009</td>
			<td></td>
		</tr>
		<tr>
			<td>DMEM/F12</td>
			<td>Gibco</td>
			<td>10565-018</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum</td>
			<td>Thermo Fisher scientific</td>
			<td>16140071</td>
			<td></td>
		</tr>
		<tr>
			<td>Fluorsheild with DAPI</td>
			<td>sigma&#160;</td>
			<td>F6057</td>
			<td></td>
		</tr>
		<tr>
			<td>Forcep</td>
			<td>Dumont</td>
			<td>0508-L5-P0</td>
			<td></td>
		</tr>
		<tr>
			<td>HBSS</td>
			<td>Thermo Fisher scientific</td>
			<td>14065056</td>
			<td></td>
		</tr>
		<tr>
			<td>HEPES</td>
			<td>Thermo Fisher scientific</td>
			<td>15630080</td>
			<td></td>
		</tr>
		<tr>
			<td>N2 supplement</td>
			<td>Gibco</td>
			<td>17502-048</td>
			<td></td>
		</tr>
		<tr>
			<td>Phalloidin-iFluor 647 Reagent</td>
			<td>abcam</td>
			<td>ab176759</td>
			<td></td>
		</tr>
		<tr>
			<td>Stage Top Incubator</td>
			<td>TOKAI HIT</td>
			<td>WELSX</td>
			<td></td>
		</tr>
		<tr>
			<td>Strain C57BL/6 mouse messenchymal stem cells with GFP</td>
			<td>cyagen</td>
			<td>MUBMX-01101</td>
			<td></td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>sigma&#160;</td>
			<td>T8787</td>
			<td></td>
		</tr>
	</tbody>
</table>

in vitro time-lapse live-cell imaging to explore cell migration toward the organ of corti

Um die Auswirkungen von mesenchymalen Stammzellen (MSCs) auf die Zellregeneration und -behandlung zu untersuchen, verfolgt diese Methode MSC-Migration und morphologische Veränderungen nach Derkokultur mit Cochlea-Epithel. Das Organ von Corti wurde auf einem Kunststoffdeckel immobilisiert, indem ein Teil der Reissner-Membran gedrückt wurde, der während der Zerlegung erzeugt wurde. MSCs, die durch einen Glaszylinder begrenzt waren, migrierten zum Cochlea-Epithel, als der Zylinder entfernt wurde. Ihre vorherrschende Lokalisation wurde im Modiolus des Organs von Corti beobachtet, ähnlich ausgerichtet in eine Richtung, die der der Nervenfasern ähnelt. Einige MSCs wurden jedoch im Limbusbereich lokalisiert und zeigten eine horizontal längliche Form. Darüber hinaus wurde die Migration in den Haarzellbereich erhöht, und die Morphologie der MSCs änderte sich nach der Kanamycin-Behandlung in verschiedene Formen. Zusammenfassend deuten die Ergebnisse dieser Studie darauf hin, dass die Kokultur von MSCs mit Cochlea-Epithel für die Entwicklung von Therapeutika durch Zelltransplantation und für Studien zur Zellregeneration nützlich sein wird, die verschiedene Bedingungen und Faktoren untersuchen können.

Die In-vitro-Migration von MSCs im dreidimensionalen Modus wurde durch ein Transwell-System oder durch die traditionelle Wundheilungsmethode zur Beobachtung der Migration im zweidimensionalen (2D) Modus11bewertet. Das Organ von Corti ist eine komplexe Struktur, die aus verschiedenen Zellen wie Boettcherzellen, Claudius-Zellen, Deiter-Zellen, Säulenzellen, Hensen-Zellen, äußeren Haarzellen, inneren Haarzellen, Nervenfasern, Basilarmembran und Reikularlamina<sup c...

Watch this Scientific Journal Video about In vitro Time-lapse Live-Cell Imaging to Explore Cell Migration toward the Organ of Corti at JoVE.com

In vitro Time-lapse Live-Cell Imaging to Explore Cell Migration toward the Organ of Corti

In dieser Studie stellen wir ein Echtzeit-Bildgebungsverfahren unter Verwendung der konfokalen Mikroskopie vor, um Zellen zu beobachten, die sich durch Ex-vivo-Inkubation mit dem Cochlea-Epithel, das das Organ von Corti enthält, in Richtung geschädigtes Gewebe bewegen.

In vitro Time-lapse Live-Cell Imaging zur Erforschung der Zellmigration zum Organ von Corti

To study the effects of mesenchymal stem cells (MSCs) on cell regeneration and treatment, this method tracks MSC migration and morphological changes after ...

in-vitro-time-lapse-live-cell-imaging-to-explore-cell-migration

Research

JoVE Journal

Medicine

3.7K Aufrufe.  Yonsei University Wonju College of Medicine. In dieser Studie stellen wir ein Echtzeit-Bildgebungsverfahren unter Verwendung der konfokalen Mikroskopie vor, um Zellen zu beobachten, die sich durch Ex-vivo-Inkubation mit dem Cochlea-Epithel, das das Organ von Corti enthält, in Richtung geschädigtes Gewebe bewegen.

Serie: In vitro Time-lapse Live-Cell Imaging to Explore Cell Migration toward the Organ of Corti

Evaluation of Cancer Stem Cell Migration Using Compartmentalizing Microfluidic Devices and Live Cell Imaging

In the last 40 years, the United States invested over 200 billion dollars on cancer research, resulting in only a 5% decrease in death rate. A major obstacle for improving patient outcomes is the poor understanding of mechanisms underlying cellular migration associated with aggressive cancer cell invasion, metastasis and therapeutic resistance1. Glioblastoma Multiforme (GBM), the most prevalent primary malignant adult brain tumor2, exemplifies this difficulty. Despite standard surgery, radiation and chemotherapies, patient median survival is only fifteen months, due to aggressive GBM infiltration into adjacent brain and rapid cancer recurrence2. The interactions of aberrant cell migratory mechanisms and the tumor microenvironment likely differentiate cancer from normal cells3. Therefore, improving therapeutic approaches for GBM require a better understanding of cancer cell migration mechanisms. Recent work suggests that a small subpopulation of cells within GBM, the brain tumor stem cell (BTSC), may be responsible for therapeutic resistance and recurrence. Mechanisms underlying BTSC migratory capacity are only starting to be characterized1,4.
Due to a limitation in visual inspection and geometrical manipulation, conventional migration assays5 are restricted to quantifying overall cell populations. In contrast, microfluidic devices permit single cell analysis because of compatibility with modern microscopy and control over micro-environment6-9.
We present a method for detailed characterization of BTSC migration using compartmentalizing microfluidic devices. These PDMS-made devices cast the tissue culture environment into three connected compartments: seeding chamber, receiving chamber and bridging microchannels. We tailored the device such that both chambers hold sufficient media to support viable BTSC for 4-5 days without media exchange. Highly mobile BTSCs initially introduced into the seeding chamber are isolated after migration though bridging microchannels to the parallel receiving chamber. This migration simulates cancer cellular spread through the interstitial spaces of the brain. The phase live images of cell morphology during migration are recorded over several days. Highly migratory BTSC can therefore be isolated, recultured, and analyzed further. 
Compartmentalizing microfluidics can be a versatile platform to study the migratory behavior of BTSCs and other cancer stem cells. By combining gradient generators, fluid handling, micro-electrodes and other microfluidic modules, these devices can also be used for drug screening and disease diagnosis6. Isolation of an aggressive subpopulation of migratory cells will enable studies of underlying molecular mechanisms.

A compartmentalizing microfluidic device for investigating cancer stem cell migration is described. This novel platform creates a viable cellular microenvironment and enables microscopic visualization of live cell locomotion. Highly motile cancer cells are isolated to study molecular mechanisms of aggressive infiltration, potentially leading to more effective future therapies.

Evaluation of Cancer Stem Cell Migration Mit Abschottung Mikrofluidiksysteme und Live Cell Imaging

In the last 40 years, the United States invested over 200 billion dollars on cancer research, resulting in only a 5% decrease in death rate. A major ...

Forschung

Medizin

MAME Models for 4D Live-cell Imaging of Tumor: Microenvironment Interactions that Impact Malignant Progression

We have developed 3D coculture models, which we term MAME (mammary architecture and microenvironment engineering), and used them for live-cell imaging in real-time of cell:cell interactions. Our overall goal was to develop models that recapitulate the architecture of preinvasive breast lesions to study their progression to an invasive phenotype. Specifically, we developed models to analyze interactions among pre-malignant breast epithelial cell variants and other cell types of the tumor microenvironment that have been implicated in enhancing or reducing the progression of preinvasive breast epithelial cells to invasive ductal carcinomas. Other cell types studied to date are myoepithelial cells, fibroblasts, macrophages and blood and lymphatic microvascular endothelial cells. In addition to the MAME models, which are designed to recapitulate the cellular interactions within the breast during cancer progression, we have developed comparable models for the progression of prostate cancers. 
Here we illustrate the procedures for establishing the 3D cocultures along with the use of live-cell imaging and a functional proteolysis assay to follow the transition of cocultures of breast ductal carcinoma in situ (DCIS) cells and fibroblasts to an invasive phenotype over time, in this case over twenty-three days in culture. The MAME cocultures consist of multiple layers. Fibroblasts are embedded in the bottom layer of type I collagen. On that is placed a layer of reconstituted basement membrane (rBM) on which DCIS cells are seeded. A final top layer of 2% rBM is included and replenished with every change of media. To image proteolysis associated with the progression to an invasive phenotype, we use dye-quenched (DQ) fluorescent matrix proteins (DQ-collagen I mixed with the layer of collagen I and DQ-collagen IV mixed with the middle layer of rBM) and observe live cultures using confocal microscopy. Optical sections are captured, processed and reconstructed in 3D with Volocity visualization software. Over the course of 23 days in MAME cocultures, the DCIS cells proliferate and coalesce into large invasive structures. Fibroblasts migrate and become incorporated into these invasive structures. Fluorescent proteolytic fragments of the collagens are found in association with the surface of DCIS structures, intracellularly, and also dispersed throughout the surrounding matrix. Drugs that target proteolytic, chemokine/cytokine and kinase pathways or modifications in the cellular composition of the cocultures can reduce the invasiveness, suggesting that MAME models can be used as preclinical screens for novel therapeutic approaches.

We have developed 3D coculture models for live-cell imaging in real-time of interactions among breast tumor cells and other cells in their microenvironment that impact progression to an invasive phenotype. These models can serve as preclinical screens for drugs to target paracrine-induced proteolytic, chemokine/cytokine and kinase pathways implicated in invasiveness.

MAME Modelle für die 4D-Bildgebung lebender Zellen von Tumor: Mikroumgebung Wechselwirkungen, die Einfluss auf maligne Progression

We have developed 3D coculture models, which we term MAME (mammary architecture and microenvironment engineering), and used them for live-cell imaging in ...

The Use of Pharmacological-challenge fMRI in Pre-clinical Research: Application to the 5-HT System

Pharmacological MRI (phMRI) is a new and promising method to study the effects of substances on brain function that can ultimately be used to unravel underlying neurobiological mechanisms behind drug action and neurotransmitter-related disorders, such as depression and ADHD. Like most of the imaging methods (PET, SPECT, CT) it represents a progress in the investigation of brain disorders and the related function of neurotransmitter pathways in a non-invasive way with respect of the overall neuronal connectivity. Moreover it also provides the ideal tool for translation to clinical investigations. MRI, while still behind in molecular imaging strategies compared to PET and SPECT, has the great advantage to have a high spatial resolution and no need for the injection of a contrast-agent or radio-labeled molecules, thereby avoiding the repetitive exposure to ionizing radiations. Functional MRI (fMRI) is extensively used in research and clinical setting, where it is generally combined with a psycho-motor task. phMRI is an adaptation of fMRI enabling the investigation of a specific neurotransmitter system, such as serotonin (5-HT), under physiological or pathological conditions following activation via administration of a specific challenging drug.
The aim of the method described here is to assess brain 5-HT function in free-breathing animals. By challenging the 5-HT system while simultaneously acquiring functional MR images over time, the response of the brain to this challenge can be visualized. Several studies in animals have already demonstrated that drug-induced increases in extracellular levels of e.g. 5-HT (releasing agents, selective re-uptake blockers, etc) evoke region-specific changes in blood oxygenation level dependent (BOLD) MRI signals (signal due to a change of the oxygenated/deoxygenated hemoglobin levels occurring during brain activation through an increase of the blood supply to supply the oxygen and glucose to the demanding neurons) providing an index of neurotransmitter function. It has also been shown that these effects can be reversed by treatments that decrease 5-HT availability16,13,18,7. In adult rats, BOLD signal changes following acute SSRI administration have been described in several 5-HT related brain regions, i.e. cortical areas, hippocampus, hypothalamus and thalamus9,16,15. Stimulation of the 5-HT system and its response to this challenge can be thus used as a measure of its function in both animals and humans2,11.

The goal of this technique is to assess serotonin (5-HT) neurotransmitter function in the live and free-breathing animal with pharmacological magnetic resonance imaging (phMRI) and an intravenous challenge with a selective serotonin reuptake inhibitor (SSRI), fluoxetine.

Die Verwendung von pharmakologischen fMRT-Herausforderung in der präklinischen Forschung: Anwendung auf die 5-HT-System

Pharmacological MRI (phMRI) is a new and promising method to study the effects of substances on brain function that can ultimately be used to unravel ...

Time-lapse Imaging of Primary Preneoplastic Mammary Epithelial Cells Derived from Genetically Engineered Mouse Models of Breast Cancer

Time-lapse imaging can be used to compare behavior of cultured primary preneoplastic mammary epithelial cells derived from different genetically engineered mouse models of breast cancer. For example, time between cell divisions (cell lifetimes), apoptotic cell numbers, evolution of morphological changes, and mechanism of colony formation can be quantified and compared in cells carrying specific genetic lesions. Primary mammary epithelial cell cultures are generated from mammary glands without palpable tumor. Glands are carefully resected with clear separation from adjacent muscle, lymph nodes are removed, and single-cell suspensions of enriched mammary epithelial cells are generated by mincing mammary tissue followed by enzymatic dissociation and filtration. Single-cell suspensions are plated and placed directly under a microscope within an incubator chamber for live-cell imaging. Sixteen 650 &mu;m x 700 &mu;m fields in a 4x4 configuration from each well of a 6-well plate are imaged every 15 min for 5 days. Time-lapse images are examined directly to measure cellular behaviors that can include mechanism and frequency of cell colony formation within the first 24 hr of plating the cells (aggregation versus cell proliferation), incidence of apoptosis, and phasing of morphological changes. Single-cell tracking is used to generate cell fate maps for measurement of individual cell lifetimes and investigation of cell division patterns. Quantitative data are statistically analyzed to assess for significant differences in behavior correlated with specific genetic lesions.

Time-lapse imaging is used to assess behavior of primary preneoplastic mammary epithelial cells derived from genetically engineered mouse models of breast cancer risk to determine if there are correlations between specific behavioral parameters and distinct genetic lesions.

Zeitraffer-Imaging of Primary Präkanzeröse Brustepithelzellen aus gentechnisch veränderten Mausmodellen der Breast Cancer Abgeleitet

Time-lapse  imaging can be used to compare behavior of cultured primary preneoplastic  mammary epithelial cells derived from different genetically ...

The Use of Reverse Phase Protein Arrays (RPPA) to Explore Protein Expression Variation within Individual Renal Cell Cancers

Currently there is no curative treatment for metastatic clear cell renal cell cancer, the commonest variant of the disease. A key factor in this treatment resistance is thought to be the molecular complexity of the disease 1. Targeted therapy such as the tyrosine kinase inhibitor (TKI)-sunitinib have been utilized, but only 40% of patients will respond, with the overwhelming majority of these patients relapsing within 1 year 2. As such the question of intrinsic and acquired resistance in renal cell cancer patients is highly relevant 3.
In order to study resistance to TKIs, with the ultimate goal of developing effective, personalized treatments, sequential tissue after a specific period of targeted therapy is required, an approach which had proved successful in chronic myeloid leukaemia 4. However the application of such a strategy in renal cell carcinoma is complicated by the high level of both inter- and intratumoral heterogeneity, which is a feature of renal cell carcinoma5,6 as well as other solid tumors 7. Intertumoral heterogeneity due to transcriptomic and genetic differences is well established even in patients with similar presentation, stage and grade of tumor. In addition it is clear that there is great morphological (intratumoral) heterogeneity in RCC, which is likely to represent even greater molecular heterogeneity. Detailed mapping and categorization of RCC tumors by combined morphological analysis and Fuhrman grading allows the selection of representative areas for proteomic analysis.
Protein based analysis of RCC8 is attractive due to its widespread availability in pathology laboratories; however, its application can be problematic due to the limited availability of specific antibodies 9. Due to the dot blot nature of the Reverse Phase Protein Arrays (RPPA), antibody specificity must be pre-validated; as such strict quality control of antibodies used is of paramount importance. Despite this limitation the dot blot format does allow assay miniaturization, allowing for the printing of hundreds of samples onto a single nitrocellulose slide. Printed slides can then be analyzed in a similar fashion to Western analysis with the use of target specific primary antibodies and fluorescently labelled secondary antibodies, allowing for multiplexing. Differential protein expression across all the samples on a slide can then be analyzed simultaneously by comparing the relative level of fluorescence in a more cost-effective and high-throughput manner.

The Use of Reverse Phase Protein Arrays RPPA to Explore Protein Expression Variation within Individual Renal Cell Cancers

RPPA enables the protein expression of hundreds of samples, printed on nitrocellulose slides to be interrogated simultaneously, using fluorescently labelled antibodies. This technique has been applied to study the effect of drug treatment heterogeneity within clear cell renal carcinoma.

Der Einsatz von Reverse Phase Protein Arrays (RPPA) an Protein Expression Variation innerhalb der einzelnen Renal Cell Cancers erkunden

Currently there is no curative treatment for metastatic clear cell renal cell cancer, the commonest variant of the disease. A key factor in this treatment ...

Confocal Time Lapse Imaging as an Efficient Method for the Cytocompatibility Evaluation of Dental Composites

It is generally accepted that in vitro cell material interaction is a useful criterion in the evaluation of dental material biocompatibility. The objective of this study was to use 3D CLSM time lapse confocal imaging to assess the in vitro biocompatibility of dental composites. This method provides an accurate and sensitive indication of viable cell rate in contact with dental composite extracts. The ELS extra low shrinkage, a dental composite used for direct restoration, has been taken as example. In vitro assessment was performed on cultured primary human gingival fibroblast cells using Live/Dead staining. Images were obtained with the FV10i confocal biological inverted system and analyzed with the FV10-ASW 3.1 Software. Image analysis showed a very slight cytotoxicity in the presence of the tested composite after 5 hours of time lapse. A slight decrease of cell viability was shown in contact with the tested composite extracts compared to control cells. The findings highlighted the use of 3D CLSM time lapse imaging as a sensitive method to qualitatively and quantitatively evaluate the biocompatibility behavior of dental composites.

The most studied aspect of the biocompatibility of dental composites is their cytotoxicity 3D CLSM time lapse imaging combined with fluorescent signal quantification allows sensitive evaluation of the cell fate over time. Utilizing this method could be an efficient tool to assess the cytocompatibility of dental composites.

Konfokale Zeitraffer Imaging als eine effiziente Methode für die Bewertung der Cytocompatibility Dental Composites

It is generally accepted that in vitro cell material interaction is a useful criterion in the evaluation of dental material biocompatibility. The ...

Cardiac Catheterization in Mice to Measure the Pressure Volume Relationship: Investigating the Bowditch Effect

Animal models that mimic human cardiac disorders have been created to test potential therapeutic strategies. A key component to evaluating these strategies is to examine their effects on heart function. There are several techniques to measure in vivo cardiac mechanics (e.g., echocardiography, pressure/volume relations, etc.). Compared to echocardiography, real-time left ventricular (LV) pressure/volume analysis via catheterization is more precise and insightful in assessing LV function. Additionally, LV pressure/volume analysis provides the ability to instantaneously record changes during manipulations of contractility (e.g., &#946;-adrenergic stimulation) and pathological insults (e.g., ischemia/reperfusion injury). In addition to the maximum (+dP/dt) and minimum (-dP/dt) rate of pressure change in the LV, an accurate assessment of LV function via several load-independent indexes (e.g., end systolic pressure volume relationship and preload recruitable stroke work) can be attained. Heart rate has a significant effect on LV contractility such that an increase in the heart rate is the primary mechanism to increase cardiac output (i.e., Bowditch effect). Thus, when comparing hemodynamics between experimental groups, it is necessary to have similar heart rates. Furthermore, a hallmark of many cardiomyopathy models is a decrease in contractile reserve (i.e., decreased Bowditch effect). Consequently, vital information can be obtained by determining the effects of increasing heart rate on contractility. Our and others data has demonstrated that the neuronal nitric oxide synthase (NOS1) knockout mouse has decreased contractility. Here we describe the procedure of measuring LV pressure/volume with increasing heart rates using the NOS1 knockout mouse model.

This article describes the measurement of murine left ventricular function via pressure/volume analysis at different heart rates.

Herzkatheter in Mäuse, um den Druck Volumen Relationship Maßnahme: Untersuchung der Bowditch Effect

Animal models that mimic human cardiac disorders have been created to test potential therapeutic strategies. A key component to evaluating these ...

Leprdb Mouse Model of Type 2 Diabetes: Pancreatic Islet Isolation and Live-cell 2-Photon Imaging Of Intact Islets

Type 2 diabetes is a chronic disease affecting 382 million people in 2013, and is expected to rise to 592 million by 2035 1. During the past 2 decades, the role of beta-cell dysfunction in type 2 diabetes has been clearly established 2. Research progress has required methods for the isolation of pancreatic islets. The protocol of the islet isolation presented here shares many common steps with protocols from other groups, with some modifications to improve the yield and quality of isolated islets from both the wild type and diabetic Leprdb (db/db) mice. A live-cell 2-photon imaging method is then presented that can be used to investigate the control of insulin secretion within islets.

Leprdb Mouse Model of Type 2 Diabetes: Pancreatic Islet Isolation and Live-cell 2-Photon Imaging Of Intact Islets

We present here a protocol for the isolation of islets from the mouse model of type 2 diabetes, Leprdb and details of a live-cell assay for measurement of insulin secretion from intact islets that utilizes 2 photon microscopy.

Lepr<sup&gt; Db</sup&gt; Mausmodell des Typ-2-Diabetes: Pancreatic Islet Isolation und Live-cell 2-Photonen-Imaging von intakten Inseln

Type 2 diabetes is a chronic disease affecting 382 million people in 2013, and is expected to rise to 592 million by 2035 1. During the past 2 decades, ...

Through the Looking Glass: Time-lapse Microscopy and Longitudinal Tracking of Single Cells to Study Anti-cancer Therapeutics

The response of single cells to anti-cancer drugs contributes significantly in determining the population response, and therefore is a major contributing factor in the overall outcome. Immunoblotting, flow cytometry and fixed cell experiments are often used to study how cells respond to anti-cancer drugs. These methods are important, but they have several shortcomings. Variability in drug responses between cancer and normal cells, and between cells of different cancer origin, and transient and rare responses are difficult to understand using population averaging assays and without being able to directly track and analyze them longitudinally. The microscope is particularly well suited to image live cells. Advancements in technology enable us to routinely image cells at a resolution that enables not only cell tracking, but also the observation of a variety of cellular responses. We describe an approach in detail that allows for the continuous time-lapse imaging of cells during the drug response for essentially as long as desired, typically up to 96 hr. Using variations of the approach, cells can be monitored for weeks. With the employment of genetically encoded fluorescent biosensors numerous processes, pathways and responses can be followed. We show examples that include tracking and quantification of cell growth and cell cycle progression, chromosome dynamics, DNA damage, and cell death. We also discuss variations of the technique and its flexibility, and highlight some common pitfalls.

Here, we describe a method of long-term time-lapse microscopy to longitudinally track single cells in response to anti-cancer therapeutics.

Durch den Spiegel: Zeitraffer-Mikroskopie und Longitudinal-Tracking von Einzelzellen Anti-Krebs-Therapeutika zu studieren

The response of single cells to anti-cancer drugs contributes significantly in determining the population response, and therefore is a major contributing ...

Extended Time-lapse Intravital Imaging of Real-time Multicellular Dynamics in the Tumor Microenvironment

In the tumor microenvironment, host stromal cells interact with tumor cells to promote tumor progression, angiogenesis, tumor cell dissemination and metastasis. Multicellular interactions in the tumor microenvironment can lead to transient events including directional tumor cell motility and vascular permeability. Quantification of tumor vascular permeability has frequently used end-point experiments to measure extravasation of vascular dyes. However, due to the transient nature of multicellular interactions and vascular permeability, the kinetics of these dynamic events cannot be discerned. By labeling cells and vasculature with injectable dyes or fluorescent proteins, high-resolution time-lapse intravital microscopy has allowed the direct, real-time visualization of transient events in the tumor microenvironment. Here we describe a method for using multiphoton microscopy to perform extended intravital imaging in live mice to directly visualize multicellular dynamics in the tumor microenvironment. This method details cellular labeling strategies, the surgical preparation of a mammary skin flap, the administration of injectable dyes or proteins by tail vein catheter and the acquisition of time-lapse images. The time-lapse sequences obtained from this method facilitate the visualization and quantitation of the kinetics of cellular events of motility and vascular permeability in the tumor microenvironment.

This protocol describes the use of multiphoton microscopy to perform extended time-lapse imaging of multicellular interactions in real time, in vivo at single cell resolution.

Erweiterte Zeitraffer-Intravital Imaging von Echtzeit-Vielzellige Dynamics im Tumormikromilieu

In the tumor microenvironment, host stromal cells interact with tumor cells to promote tumor progression, angiogenesis, tumor cell dissemination and ...