Vorremmo ringraziare Mechthild Herschbach e Anke Dech per un&#39;eccellente assistenza tecnica.

Questo articolo descrive l&#39;utilizzo di un chip basato su piattaforma (fig. 1) per la tridimensionalità coltura di linee cellulari e cellule primarie. Dato che molte cellule fare esprimere le funzioni organotipica solo in un ambiente 3D, abbiamo sviluppato un chip polimero che fornisce una impalcatura a cui le cellule possono aderire in tutte le direzioni spaziali, e che può essere montato in un alloggiamento bioreattore per il controllo del flusso del fluido , la tensione di ossigeno ecc A seconda del disegno sperimentale, la superficie del polimero può essere modificato con tecniche diverse, ad esempio, l&#39;irradiazione UV, PECVD, γ-innesto o convenzionale chimica umida. <img src="/files/ftp_upload/old/564_2008_9_19_6/564_Figure-01.png" alt="564_Figure-01.png" width="546" height="386" /> Figura 01 1. De-aerazione e idrofilizzazione del chip Prima dell&#39;uso, il chip deve essere disaerata e hydrophilized. Per questo, una serie di alcol viene effettuata. Soluzioni isopropanolo composta al 100%, 70%, 50%, 30% di isopropanolo in DMPC trattati con acqua sono preparati e il chip viene immerso in ciascuna concentrazione, a cominciare dalla soluzione al 100%, per un massimo di 30 anni. La fase finale della serie è costituito da pura pirocarbonato Dimetil (DMPC)-acqua trattata. Da questo punto in poi, è importante mantenere il chip bagnato. 2. Collagene I rivestimento Dopo la serie di alcol, il chip è di solito ricoperto con una soluzione di collagene che dalla coda di ratto. Dalla soluzione di collagene stock di 2 mg / ml in 0,2% di acido acetico un&#39;aliquota pari al 30 mcg proteina collagene viene diluito con DMPC trattati con acqua ad un volume finale di 150 microlitri. Ciò si traduce in un rivestimento di collagene della superficie del chip con una densità di 10 mg di collagene I superficie per cm 2 di superficie. 3. Inoculazione di cellule di carcinoma epatocellulare Cellule di carcinoma epatocellulare di linea Hep G2 sono trypsinized e contati. A breve termine esperimenti (1 a 6 giorni) 5 * 10 6 cellule vengono inoculate in ogni chip e la relativa sorveglianza e 6 centimetri di tessuto cultura piastre Petri. Per inoculte, il chip 5 * 10 6 cellule sono risospese in 150 microlitri terreno di coltura e messo in cima alla zona microstrutturate del chip (fig. 2). In seguito, si è posto in un incubatore per 2-3 ore. Durante questo periodo di incubazione le cellule sedimento nella micro-contenitori e aderire al collagene I rivestite patibolo. <img src="/files/ftp_upload/old/564_2008_9_19_7/564_Figure-02.png" alt="564_Figure-02.png" width="300" height="225" /> Figura 2 4. L&#39;inserimento del chip nel corpo bioreattore Dopo il periodo di incubazione, il chip viene rimosso dal termostato e montato nella custodia bioreattore. Per questo, sotto il banco pulito, il bioreattore premontato viene rimosso dalla confezione sterile e smontato in una misura che consente l&#39;inserimento del chip. Il chip viene accuratamente gestita con una pinza sterile e posizionato nella scanalatura che contiene la guarnizione che sigilla il chip e che si traduce nella generazione di un vano superiore e inferiore del bioreattore. Poi, il bioreattore è montato di nuovo e trasferito l&#39;incubatore in cui è collegata alla pompa, la fornitura di gas e l&#39;analizzatore di ossigeno. 5. Riempimento del sistema Non appena il bioreattore è collegato al serbatoio di media, pompa e il ciclo di fornitura del gas a circuito chiuso è pieno di media. Questo viene fatto posizionando il 3-way-connettori in modo tale che superfusione, che è definito come il passaggio del fluido sopra la parte superiore del chip, è raggiunto. Questo porta a una scarica di aria racchiusa dalla circolazione bioreattore senza rimuovere le cellule dal patibolo. Dopo che il sistema è completamente piena di media, il 3-way-connettori sono collegati in modo tale che perfusione, che è definito come il flusso dal basso il chip attraverso il tessuto, è raggiunto. Nella configurazione di perfusione il flusso è regolato ai bisogni della cellula che per epatociti varia tipicamente 6-50 microlitri / min. 6. Campionatura Durante l&#39;esperimento i campioni mezzo può essere disegnato. Per questo, siringhe sono collegate alle porte sterile sulla parte superiore del serbatoio mezzo. Dopo il campionamento, le porte sono sterilizzati con il 70% di isopropanolo. 7. Isolamento di cellule intatte dal chip per le applicazioni a valle Alla fine dell&#39;esperimento, i bioreattori sono scollegati dalla rete del gas e la pompa a rulli, trasferiti al banco pulita e smontata, come descritto in precedenza. Con una pinza sterile, il chip viene rimosso dal corpo bioreattore, postoin un piatto cm 3.5 Petri e sciacquati con PBS. In seguito, il chip è incubato con tripsina / EDTA (0,25% / 0,53 mm) per 5-15 minuti in un incubatore per staccare le cellule dalla zona microstrutturata. La sospensione di cellule raccolte è centrifugato per 5 min a 600 g. Le cellule possono quindi essere utilizzati per tradizionali applicazioni a valle, ad esempio, l&#39;RNA totale o isolamento delle proteine. Di routine, isoliamo RNA totale (PARIS kit, Ambion Inc., Austin, Texas, USA) per l&#39;analisi microarray e real-time RT-PCR. Espressione della proteina è analizzata dopo colorazione immunoistochimica delle cellule all&#39;interno del chip con un microscopio a scansione laser, ma può anche essere analizzato in caso contrario, ad esempio, in citometria a flusso.

<ol>
	<li>Berry, M. N., Friend, D. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-yield+preparation+of+isolated+rat+liver+parenchymal+cells:+A+biochemical+and+fine+structural+study.">High-yield preparation of isolated rat liver parenchymal cells: A biochemical and fine structural study.</a> J. Cell Biol. 53, 506-520 (1969).</li><li>Seglen, P. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+rat+liver+cells.+3.+Enzymatic+requirements+for+tissue+dispersion.">Preparation of rat liver cells. 3. Enzymatic requirements for tissue dispersion.</a> Exp. Cell Res. 82, 391-398 (1973).</li><li>Giselbrecht, S., Gietzelt, T., Gottwald, E., Trautmann, C., Truckenmueller, R., Weibezahn, K. F., Welle, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3D+tissue+culture+substrates+produced+by+microthermoforming+of+pre-processed+polymer+films.">3D tissue culture substrates produced by microthermoforming of pre-processed polymer films.</a> Biomed. Microdev. 8, 191-199 (2006).</li><li>Welle, A., Gottwald, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=UV-based+patterning+of+polymeric+substrates+for+cell+culture+applications.">UV-based patterning of polymeric substrates for cell culture applications.</a> Biomed. Microdev. 4, 33-41 (2002).</li><li>Gottwald, E., Giselbrecht, S., Augspurger, C., Lahni, B., Dambrowsky, N., Truckenmueller, R., Piotter, V., Gietzelt, T., Wendt, O., Pfleging, W., Welle, A., Rolletschek, A., Wobus, A. M., Weibezahn, K. -. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+chip-based+platform+for+the+in+vitro+generation+of+tissues+in+three-dimensional+organization.">A chip-based platform for the in vitro generation of tissues in three-dimensional organization.</a> Lab Chip. 7, 777-785 (2007).</li><li>Eschbach, E., Chatterjee, S. S., Noldner, M., Gottwald, E., Dertinger, H., Weibezahn, K. -. F., Knedlitschek, G., G, <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microstructured+scaffolds+for+liver+tissue+with+high+density:+Morphological+and+biochemical+characterization+of+tissue+aggregates.">Microstructured scaffolds for liver tissue with high density: Morphological and biochemical characterization of tissue aggregates.</a> J. Cell. Biochem. 95, 243-255 (2005).</li></ol>

The authors have nothing to disclose.

Abbiamo sviluppato un chip basato su piattaforma per il tridimensionale coltura di cellule in bioreattori micro attivamente perfusi. I chip possono essere fabbricati da non biodegradabili e polimeri biodegradabili per stampaggio ad iniezione micro, goffratura a caldo ed micro tecniche di termoformatura 3. A seconda del disegno sperimentale, la superficie del polimero può essere modificato da irradiazione UV-4. Linee cellulari di epatociti così come epatociti primari di ratto può essere coltivata con successo in ques...

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		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Cells</td>
<td>Other</td>
<td>ATCC</td>
<td>HB-8065</td>
<td>&nbsp;</td>
<tr>
<td>Collagen I from rat tail</td>
<td>Reagent</td>
<td>Roche Diagnostics</td>
<td>11 179 179 001</td>
<td>&nbsp;</td>
<tr>
<td>PARIS kit</td>
<td>Reagent</td>
<td>Ambion Inc.</td>
<td>AM1921</td>
<td>&nbsp;</td>
<tr>
<td>Syto16</td>
<td>Reagent</td>
<td>Invitrogen</td>
<td>S7578</td>
<td>&nbsp;</td>
<tr>
<td>anti cytokeratin 18</td>
<td>Antibody</td>
<td>Abcam plc</td>
<td>ab668</td>
<td>Primary Ab, Mouse monoclonal, used 1/100 in PBS</td>
</tr>
<tr>
<td>Anti E-cadherin</td>
<td>Antibody</td>
<td>Abcam plc</td>
<td>ab1416</td>
<td>Primary Ab, Mouse monoclonal, used 1/50 in PBS.</td>
</tr>
<tr>
<td>Goat anti-albumin</td>
<td>Reagent</td>
<td>Bethyl Laboratories</td>
<td>E80-129</td>
<td>Primary Ab, goat anti-human Albumin, used 1/200 in PBS</td>
</tr>
<tr>
<td>Rabbit anti-mouse IgG1</td>
<td>Antibody</td>
<td>Invitrogen</td>
<td>A11059</td>
<td>Secondary Ab, Alexa Flour 488 conjugated, used 1/100 in PBS + 0.5 % BSA</td>
</tr>
<tr>
<td>Cy3 anti-goat IgG</td>
<td>Reagent</td>
<td>Jackson ImmunoResearch Lab</td>
<td>705-165-003</td>
<td>Cy3 AffiniPure donkey a-goat IgG Ab, used 1/700 in PBS + 0.5% BSA</td>
</tr>		</tbody>
		</table>
		</div>

chip-based three-dimensional cell culture in perfused micro-bioreactors

Abbiamo sviluppato un chip basato su sistema di coltura cellulare per la tridimensionalità coltivazione delle cellule. Il chip è tipicamente realizzati in polimeri non biodegradabili, per esempio, policarbonato o polimetilmetacrilato per stampaggio ad iniezione micro, micro caldo o goffratura micro termoformatura. Ma, può anche essere realizzati in polimeri biodegradabili. Le sue dimensioni sono 0,7 1 x 20 x 20 x 0,7 1 mm (AxPxL). Le principali caratteristiche del chip utilizzati sono sia una griglia di un massimo di 1156 mc micro-contenitori (cf-chip) ciascuno delle dimensioni di 120-300 x 300 x 300 μ (AxPxL) o recessi rotonda con diametro di 300 μ e una profondità di 300 μ (r-chip). L&#39;impalcatura può ospitare 10 milioni. cellule in una configurazione tridimensionale. Per un ottimale dei nutrienti e gas, il chip è inserito in un alloggiamento bioreattore. Il bioreattore è parte di un circuito chiuso sterile circolazione che, nella configurazione più semplice, è additionaly composto da una pompa a rulli ed un serbatoio con una media di fornitura di gas. Il bioreattore può essere eseguito in perfusione, superfusione, o anche una modalità di funzionamento misto. Abbiamo coltivato con successo linee cellulari e cellule primarie per periodi di diverse settimane. Per le cellule di fegato di ratto primarie si potrebbe mostrare una conservazione delle funzioni del organotipica per più di 2 settimane. Per linee cellulari di carcinoma epatocellulare potremmo mostrare l&#39;induzione di geni specifici del fegato o solo leggermente espresso in coltura monostrato standard. Il sistema potrebbe anche essere utile come sistema di cellule staminali dal esperimenti di coltivazione prima differenziazione di linee di cellule staminali sono promettenti.

Watch this Scientific Journal Video about Chip-based Three-dimensional Cell Culture in Perfused Micro-bioreactors at JoVE.com

Chip-based Three-dimensional Cell Culture in Perfused Micro-bioreactors

Descriviamo un chip basato su piattaforma per il tridimensionale coltura di cellule in micro-bioreattori. Un chip in grado di ospitare fino a 10 milioni. cellule che possono essere coltivate in condizioni ben definite in relazione al flusso del fluido, tensione ecc ossigeno in una sterile, la circolazione ad anello chiuso.

Basato su chip tridimensionale coltura cellulare in perfuso Micro-bioreattori

We have developed a chip-based cell culture system for the three-dimensional cultivation of cells. The chip is typically manufactured from ...

chip-based-three-dimensional-cell-culture-perfused-micro

Research

JoVE Journal

Biology

11.2K Views.  Forschungszentrum Karlsruhe. Descriviamo un chip basato su piattaforma per il tridimensionale coltura di cellule in micro-bioreattori. Un chip in grado di ospitare fino a 10 milioni. cellule che possono essere coltivate in condizioni ben definite in relazione al flusso del fluido, tensione ecc ossigeno in una sterile, la circolazione ad anello chiuso.

Video: Chip-based Three-dimensional Cell Culture in Perfused Micro-bioreactors

Microfabrication of Chip-sized Scaffolds for Three-dimensional Cell cultivation

Using microfabrication technologies is a prerequisite to create scaffolds of reproducible geometry and constant quality for three-dimensional cell cultivation. These technologies offer a wide spectrum of advantages not only for manufacturing but also for different applications. The size and shape of formed cell clusters can be influenced by the exact and reproducible architecture of the microfabricated scaffold and, therefore, the diffusion path length of nutrients and gases can be controlled.1 This is unquestionably a useful tool to prevent apoptosis and necrosis of cells due to an insufficient nutrient and gas supply or removal of cellular metabolites.
Our polymer chip, called CellChip, has the outer dimensions of 2 x 2 cm with a central microstructured area. This area is subdivided into an array of up to 1156 microcontainers with a typical dimension of 300 m edge length for the cubic design (cp- or cf-chip) or of 300 m diameter and depth for the round design (r-chip).2
So far, hot embossing or micro injection moulding (in combination with subsequent laborious machining of the parts) was used for the fabrication of the microstructured chips. Basically, micro injection moulding is one of the only polymer based replication techniques that, up to now, is capable for mass production of polymer microstructures.3 However, both techniques have certain unwanted limitations due to the processing of a viscous polymer melt with the generation of very thin walls or integrated through holes. In case of the CellChip, thin bottom layers are necessary to perforate the polymer and provide small pores of defined size to supply cells with culture medium e.g. by microfluidic perfusion of the containers.
In order to overcome these limitations and to reduce the manufacturing costs we have developed a new microtechnical approach on the basis of a down-scaled thermoforming process. For the manufacturing of highly porous and thin walled polymer chips, we use a combination of heavy ion irradiation, microthermoforming and track etching. In this so called "SMART" process (Substrate Modification And Replication by Thermoforming) thin polymer films are irradiated with energetic heavy projectiles of several hundred MeV introducing so-called "latent tracks" Subsequently, the film in a rubber elastic state is formed into three dimensional parts without modifying or annealing the tracks. After the forming process, selective chemical etching finally converts the tracks into cylindrical pores of adjustable diameter.

We present two processes for the microfabrication of porous polymer chips for three-dimensional cell cultivation. The first one is hot embossing combined with a solvent vapour welding process. The second one uses a recently developed microthermoforming process combined with ion track technology leading to a significant simplification of manufacture.

Microfabbricazione di chip di dimensioni Ponteggi per tridimensionale coltura cellulare

Using microfabrication technologies is a prerequisite to create scaffolds of reproducible geometry and constant quality for three-dimensional cell ...

Ricerca

Biologia

Hi-C: A Method to Study the Three-dimensional Architecture of Genomes.

The three-dimensional folding of chromosomes compartmentalizes the genome and and can bring distant functional elements, such as promoters and enhancers, into close spatial proximity 2-6. Deciphering the relationship between chromosome organization and genome activity will aid in understanding genomic processes, like transcription and replication. However, little is known about how chromosomes fold. Microscopy is unable to distinguish large numbers of loci simultaneously or at high resolution. To date, the detection of chromosomal interactions using chromosome conformation capture (3C) and its subsequent adaptations required the choice of a set of target loci, making genome-wide studies impossible 7-10.
We developed Hi-C, an extension of 3C that is capable of identifying long range interactions in an unbiased, genome-wide fashion. In Hi-C, cells are fixed with formaldehyde, causing interacting loci to be bound to one another by means of covalent DNA-protein cross-links. When the DNA is subsequently fragmented with a restriction enzyme, these loci remain linked. A biotinylated residue is incorporated as the 5' overhangs are filled in. Next, blunt-end ligation is performed under dilute conditions that favor ligation events between cross-linked DNA fragments. This results in a genome-wide library of ligation products, corresponding to pairs of fragments that were originally in close proximity to each other in the nucleus. Each ligation product is marked with biotin at the site of the junction. The library is sheared, and the junctions are pulled-down with streptavidin beads. The purified junctions can subsequently be analyzed using a high-throughput sequencer, resulting in a catalog of interacting fragments.
Direct analysis of the resulting contact matrix reveals numerous features of genomic organization, such as the presence of chromosome territories and the preferential association of small gene-rich chromosomes. Correlation analysis can be applied to the contact matrix, demonstrating that the human genome is segregated into two compartments: a less densely packed compartment containing open, accessible, and active chromatin and a more dense compartment containing closed, inaccessible, and inactive chromatin regions. Finally, ensemble analysis of the contact matrix, coupled with theoretical derivations and computational simulations, revealed that at the megabase scale Hi-C reveals features consistent with a fractal globule conformation.

The Hi-C method allows unbiased, genome-wide identification of chromatin interactions (1). Hi-C couples proximity ligation and massively parallel sequencing. The resulting data can be used to study genomic architecture at multiple scales: initial results identified features such as chromosome territories, segregation of open and closed chromatin, and chromatin structure at the megabase scale.

Hi-C: un metodo per studiare l&#39;architettura tridimensionale dei genomi.

The three-dimensional folding of chromosomes compartmentalizes the genome and and can bring distant functional elements, such as promoters and enhancers, ...

Isolation of Mammary Epithelial Cells from Three-dimensional Mixed-cell Spheroid Co-culture

While enormous efforts have gone into identifying signaling pathways and molecules involved in normal and malignant cell behaviors1-2, much of this work has been done using classical two-dimensional cell culture models, which allow for easy cell manipulation. It has become clear that intracellular signaling pathways are affected by extracellular forces, including dimensionality and cell surface tension3-4. Multiple approaches have been taken to develop three-dimensional models that more accurately represent biologic tissue architecture3. While these models incorporate multi-dimensionality and architectural stresses, study of the consequent effects on cells is less facile than in two-dimensional tissue culture due to the limitations of the models and the difficulty in extracting cells for subsequent analysis.
The important role of the microenvironment around tumors in tumorigenesis and tumor behavior is becoming increasingly recognized4. Tumor stroma is composed of multiple cell types and extracellular molecules. During tumor development there are bidirectional signals between tumor cells and stromal cells5. Although some factors participating in tumor-stroma co-evolution have been identified, there is still a need to develop simple techniques to systematically identify and study the full array of these signals6. Fibroblasts are the most abundant cell type in normal or tumor-associated stromal tissues, and contribute to deposition and maintenance of basement membrane and paracrine growth factors7.
Many groups have used three dimensional culture systems to study the role of fibroblasts on various cellular functions, including tumor response to therapies, recruitment of immune cells, signaling molecules, proliferation, apoptosis, angiogenesis, and invasion8-15. We have optimized a simple method for assessing the effects of mammary fibroblasts on mammary epithelial cells using a commercially available extracellular matrix model to create three-dimensional cultures of mixed cell populations (co-cultures)16-22. With continued co-culture the cells form spheroids with the fibroblasts clustering in the interior and the epithelial cells largely on the exterior of the spheroids and forming multi-cellular projections into the matrix. Manipulation of the fibroblasts that leads to altered epithelial cell invasiveness can be readily quantified by changes in numbers and length of epithelial projections23. Furthermore, we have devised a method for isolating epithelial cells out of three-dimensional co-culture that facilitates analysis of the effects of fibroblast exposure on epithelial behavior. We have found that the effects of co-culture persist for weeks after epithelial cell isolation, permitting ample time to perform multiple assays. This method is adaptable to cells of varying malignant potential and requires no specialized equipment. This technique allows for rapid evaluation of in vitro cell models under multiple conditions, and the corresponding results can be compared to in vivo animal tissue models as well as human tissue samples.

A simple method is described for analyzing effects of tissue fibroblasts on associated epithelial cells. The combination of this method and three-dimensional tissue culture can facilitate analysis of cells after isolation from 3D. The technique is applicable to cells of varying malignant potential, allowing systematic study of effects of tumor-associated stroma on tumor cells.

Isolamento di cellule epiteliali mammarie da tridimensionale Mixed-cell Spheroid Co-cultura

While enormous efforts have gone into identifying signaling pathways and molecules involved in normal and malignant cell behaviors1-2, much of this work ...

Two- and Three-Dimensional Live Cell Imaging of DNA Damage Response Proteins

Double-strand breaks (DSBs) are the most deleterious DNA lesions a cell can encounter. If left unrepaired, DSBs harbor great potential to generate mutations and chromosomal aberrations1. To prevent this trauma from catalyzing genomic instability, it is crucial for cells to detect DSBs, activate the DNA damage response (DDR), and repair the DNA. When stimulated, the DDR works to preserve genomic integrity by triggering cell cycle arrest to allow for repair to take place or force the cell to undergo apoptosis. The predominant mechanisms of DSB repair occur through nonhomologous end-joining (NHEJ) and homologous recombination repair (HRR) (reviewed in2). There are many proteins whose activities must be precisely orchestrated for the DDR to function properly. Herein, we describe a method for 2- and 3-dimensional (D) visualization of one of these proteins, 53BP1.
The p53-binding protein 1 (53BP1) localizes to areas of DSBs by binding to modified histones3,4, forming foci within 5-15 minutes5. The histone modifications and recruitment of 53BP1 and other DDR proteins to DSB sites are believed to facilitate the structural rearrangement of chromatin around areas of damage and contribute to DNA repair6. Beyond direct participation in repair, additional roles have been described for 53BP1 in the DDR, such as regulating an intra-S checkpoint, a G2/M checkpoint, and activating downstream DDR proteins7-9. Recently, it was discovered that 53BP1 does not form foci in response to DNA damage induced during mitosis, instead waiting for cells to enter G1 before localizing to the vicinity of DSBs6. DDR proteins such as 53BP1 have been found to associate with mitotic structures (such as kinetochores) during the progression through mitosis10.
In this protocol we describe the use of 2- and 3-D live cell imaging to visualize the formation of 53BP1 foci in response to the DNA damaging agent camptothecin (CPT), as well as 53BP1's behavior during mitosis. Camptothecin is a topoisomerase I inhibitor that primarily causes DSBs during DNA replication. To accomplish this, we used a previously described 53BP1-mCherry fluorescent fusion protein construct consisting of a 53BP1 protein domain able to bind DSBs11. In addition, we used a histone H2B-GFP fluorescent fusion protein construct able to monitor chromatin dynamics throughout the cell cycle but in particular during mitosis12. Live cell imaging in multiple dimensions is an excellent tool to deepen our understanding of the function of DDR proteins in eukaryotic cells.

This protocol describes a method for visualizing a DNA double-strand break signaling protein activated in response to DNA damage as well as its localization during mitosis.

Due-e tridimensionale Live Cell Imaging di proteine ​​danno al DNA di risposta

Double-strand breaks (DSBs) are the most deleterious DNA lesions a cell can encounter. If left unrepaired, DSBs harbor great potential to generate ...

Mouse Fetal Whole Intestine Culture System for Ex Vivo Manipulation of Signaling Pathways and Three-dimensional Live Imaging of Villus Development

Most morphogenetic processes in the fetal intestine have been inferred from thin sections of fixed tissues, providing snapshots of changes over developmental stages. Three-dimensional information from thin serial sections can be challenging to interpret because of the difficulty of reconstructing serial sections perfectly and maintaining proper orientation of the tissue over serial sections. Recent findings by Grosse et al., 2011 highlight the importance of three- dimensional information in understanding morphogenesis of the developing villi of the intestine1. Three-dimensional reconstruction of singly labeled intestinal cells demonstrated that the majority of the intestinal epithelial cells contact both the apical and basal surfaces. Furthermore, three-dimensional reconstruction of the actin cytoskeleton at the apical surface of the epithelium demonstrated that the intestinal lumen is continuous and that secondary lumens are an artifact of sectioning. Those two points, along with the demonstration of interkinetic nuclear migration in the intestinal epithelium, defined the developing intestinal epithelium as a pseudostratified epithelium and not stratified as previously thought1. The ability to observe the epithelium three-dimensionally was seminal to demonstrating this point and redefining epithelial morphogenesis in the fetal intestine. With the evolution of multi-photon imaging technology and three-dimensional reconstruction software, the ability to visualize intact, developing organs is rapidly improving. Two-photon excitation allows less damaging penetration deeper into tissues with high resolution. Two-photon imaging and 3D reconstruction of the whole fetal mouse intestines in Walton et al., 2012 helped to define the pattern of villus outgrowth2. Here we describe a whole organ culture system that allows ex vivo development of villi and extensions of that culture system to allow the intestines to be three-dimensionally imaged during their development.

Mouse Fetal Whole Intestine Culture System for Ex Vivo Manipulation of Signaling Pathways and Three-dimensional Live Imaging of Villus Development

Improved imaging technology is allowing three-dimensional imaging of organs during development. Here we describe a whole organ culture system that allows live imaging of the developing villi in the fetal mouse intestine.

Mouse fetale Whole Intestino Sistema Cultura per<em&gt; Ex Vivo</em&gt; La manipolazione delle vie di segnalazione e tridimensionale Imaging in diretta di Sviluppo del villo

Most morphogenetic processes in the fetal intestine have been inferred from thin sections of fixed tissues, providing snapshots of changes over ...

FRET Imaging in Three-dimensional Hydrogels

Imaging of F&#246;rster resonance energy transfer (FRET)&#160;is a powerful tool for examining cell biology in real-time. Studies utilizing FRET commonly employ two-dimensional (2D) culture, which does not mimic the three-dimensional (3D) cellular microenvironment. A method to perform quenched emission FRET imaging using conventional widefield epifluorescence microscopy of cells within a 3D hydrogel environment is presented. Here an analysis method for ratiometric FRET probes that yields linear ratios over the probe activation range is described. Measurement of intracellular cyclic adenosine monophosphate (cAMP) levels is demonstrated in chondrocytes under forskolin stimulation using a probe for EPAC1 activation (ICUE1) and the ability to detect differences in cAMP signaling dependent on hydrogel material type, herein a photocrosslinking hydrogel (PC-gel, polyethylene glycol dimethacrylate) and a thermoresponsive hydrogel (TR-gel). Compared with 2D FRET methods, this method requires little additional work. Laboratories already utilizing FRET imaging in 2D can easily adopt this method to perform cellular studies in a 3D microenvironment. It can further be applied to high throughput drug screening in engineered 3D microtissues. Additionally, it is compatible with other forms of FRET imaging, such as anisotropy measurement and fluorescence lifetime imaging (FLIM), and with advanced microscopy platforms using confocal, pulsed, or modulated illumination.

F&#246;rster resonance energy transfer (FRET) imaging is a powerful tool for real-time cell biology studies. Here a method for FRET imaging cells in physiologic three-dimensional (3D) hydrogel microenvironments using conventional epifluorescence microscopy is presented. An analysis for ratiometric FRET probes that yields linear ratios over the activation range is described.

FRET Imaging in idrogel tridimensionali

Imaging of F&#246;rster resonance energy transfer (FRET)&#160;is a powerful tool for examining cell biology in real-time. Studies utilizing FRET commonly ...

The Mouse Isolated Perfused Kidney Technique

The mouse isolated perfused kidney (MIPK) is a technique for keeping a mouse kidney under ex vivo conditions perfused and functional for 1 hr. This is a prerequisite for studying the physiology of the isolated organ and for many innovative applications that may be possible in the future, including perfusion decellularization for kidney bioengineering or the administration of anti-rejection or genome-editing drugs in high doses to prime the kidney for transplantation. During the time of the perfusion, the kidney can be manipulated, renal function can be assessed, and various pharmaceuticals administered. After the procedure, the kidney can be transplanted or processed for molecular biology, biochemical analysis, or microscopy.
This paper describes the perfusate and the surgical technique needed for the ex vivo perfusion of mouse kidneys. Details of the perfusion apparatus are given and data are presented showing the viability of the kidney&#39;s preparation: renal blood flow, vascular resistance, and urine data as functional, transmission electron micrographs of different nephron segments as morphological readouts, and western blots of transport proteins of different nephron segments as molecular readout.

The mouse isolated perfused kidney (MIPK) is a technique for keeping a mouse kidney under ex vivo conditions perfused and functional for 1 hr. The buffers and surgical technique are described in detail.

La tecnica del rene perfusi mouse isolato

The mouse isolated perfused kidney (MIPK) is a technique for keeping a mouse kidney under ex vivo conditions perfused and functional for 1 hr. This is a ...

Three-dimensional Reconstruction of the Vascular Architecture of the Passive CLARITY-cleared Mouse Ovary

The ovary is the main organ of the female reproductive system and is essential for the production of female gametes and for controlling the endocrine system, but the complex structural relationships and three-dimensional (3D) vasculature architectures of the ovary are not well described. In order to visualize the 3D connections and architecture of blood vessels in the intact ovary, the first important step is to make the ovary optically clear. In order to avoid tissue shrinkage, we used the hydrogel fixation-based passive CLARITY (Clear Lipid-exchanged Acrylamide-hybridized Rigid Imaging/ Immunostaining/In situ-hybridization-compatible Tissue Hydrogel) protocol method to clear an intact ovary. Immunostaining, advanced multiphoton confocal microscopy, and 3D image-reconstructions were then used for the visualization of ovarian vessels and follicular capillaries. Using this approach, we showed a significant positive correlation (P &#60;0.01) between the length of the follicular capillaries and volume of the follicular wall.

Here we present an adaptation of the passive CLARITY and 3D reconstruction method for visualization of the ovarian vasculature and follicular capillaries in intact mouse ovaries.

Ricostruzione tridimensionale dell'architettura vascolare dell'ovaia passiva sdoganate per la chiarezza del Mouse

The ovary is the main organ of the female reproductive system and is essential for the production of female gametes and for controlling the endocrine ...

Single-Cell Resolution Three-Dimensional Imaging of Intact Organoids

Organoid technology, in vitro 3D culturing of miniature tissue, has opened a new experimental window for cellular processes that govern organ development and function as well as disease. Fluorescence microscopy has played a major role in characterizing their cellular composition in detail and demonstrating their similarity to the tissue they originate from. In this article, we present a comprehensive protocol for high-resolution 3D imaging of whole organoids upon immunofluorescent labeling. This method is widely applicable for imaging of organoids differing in origin, size and shape. Thus far we have applied the method to airway, colon, kidney, and liver organoids derived from healthy human tissue, as well as human breast tumor organoids and mouse mammary gland organoids. We use an optical clearing agent, FUnGI, which enables the acquisition of whole 3D organoids with the opportunity for single-cell quantification of markers. This three-day protocol from organoid harvesting to image analysis is optimized for 3D imaging using confocal microscopy.

The entire 3D structure and cellular content of organoids, as well as their phenotypic resemblance to the original tissue can be captured using the single-cell resolution 3D imaging protocol described here. This protocol can be applied to a wide range of organoids varying in origin, size and shape.

Risoluzione a una cellula di immagini tridimensionali di organoidi intatti

Organoid technology, in vitro 3D culturing of miniature tissue, has opened a new experimental window for cellular processes that govern organ development ...

Evaluating the Angiogenetic Properties of Ovarian Cancer Stem-Like Cells using the Three-Dimensional Co-Culture System, NICO-1

Cancer stem cells (CSCs) reside in a supportive niche, constituting a microenvironment comprised of adjacent stromal cells, vessels, and extracellular matrix. The ability of CSCs to participate in the development of endothelium constitutes an important characteristic that directly contributes to the general understanding of the mechanisms of tumorigenesis and tumor metastasis. The purpose of this work is to establish a reproducible methodology to investigate the tumor-initiation capability of ovarian cancer stem cells (OCSCs). Herein, we examined the neovascularization mechanism between endothelial cells and OCSCs along with the morphological changes of endothelial cells using the in vitro co-culture model NICO-1. This protocol allows visualization of the neovascularization step surrounding the OCSCs in a time course manner. The technique can provide insight regarding the angiogenetic properties of OCSCs in tumor metastasis.

Ovarian cancer stem cells (OCSC) are responsible for cancer initiation, recurrence, therapeutic resistance, and metastasis. The OCSC vascular niche is considered to promote self-renewal of OCSCs, leading to chemoresistance. This protocol provides the basis for establishing a reproducible OCSC vascular niche model in vitro.

Valutazione delle proprietà angiogenetiche delle cellule staminali del cancro ovarico utilizzando il sistema di co-coltura tridimensionale, NICO-1

Cancer stem cells (CSCs) reside in a supportive niche, constituting a microenvironment comprised of adjacent stromal cells, vessels, and extracellular ...