Nous remercions Erika Mileti pour un excellent support technique et le Dr Antonio Di Sabatino pour fournir des chambres à oxygène. Financement: Ce travail a été soutenu par des subventions du programme-cadre de l&#39;UE 7 (IBDase, ERC: Dendroworld) et la Fondazione Cariplo à MR et le soutien d&#39;un réseau international Marie Curie de formation à la mobilité (Cross-Talk, accord de subvention n °: 21553-2) à KT.

1. Obtention et préparation du tissu <ol><li> Tissue (saine ou IBD muqueuse) est obtenue pendant la chirurgie. Une fois que l&#39;échantillon est excisé transfert au laboratoire dès que possible, en le gardant dans + + tampon HBSS sans Ca + + / Mg complété avec Pen / Strep à 4 ° C ou sur de la glace. </li></ol> * La taille de l&#39;échantillon dépend de la disponibilité du tissu: la partie du tissu obtenu est strictement ce qui n&#39;est pas nécessaire pour le diagnostic et peut varier considérablement entre les sujets sains et les MII. Les tissus sains est excisé de patients subissant une chirurgie pour le cancer du côlon. <ol start="2"><li> Laver le tissu doucement et nettoyer tout le matériel mésentérique. Séparer la couche muqueuse de la sous-muqueuse avec des ciseaux et des pinces stériles tout en gardant le tissu dans un tampon HBSS dans une boîte de Pétri (pas nécessairement immergée). Touchez la surface de la muqueuse avec la pince aussi peu que possible. </li><li> Couper la muqueuse en bandes au moins 1 cm de large et le plus longtemps possible. Utilisez deux scalpels stériles, un peu comme si vous coupiez votre nourriture. </li><li> Laver nettoyer la muqueuse doucement dans HBSS et l&#39;étendre sur une boîte de Pétri avec le côté apical vers le haut. </li></ol> 2. Montage de la soie <ol><li> Préparer un milieu frais (tisDMEM). Utilisez DMEM supplémenté avec de la glutamine (2 mM) et NaPyr (1 mM), et ajouter 15% de FBS-Na (sérum de veau foetal - Amérique du Nord), 1% ITS-X et 200 ng / ml d&#39;EGF au moment de l&#39;utilisation. </li><li> Remplissez une boîte de Pétri 10 cm avec le reste de la FBS-Na (utiliser environ 30 ml de sorte que les grilles métalliques seront complètement immergés) et submerger les grilles métalliques. Gardez la plaque ouvrir et soutenir les bouteilles en plastique sur son robinet. </li></ol> * Les grilles en métal sont en fer. La maille est de forme carrée avec un côté de 0,5 mm. <ol start="3"><li> Prenez 3 pi de colle chirurgicale avec un 10 ou 20 pipette ul. Appliquez-le soigneusement à l&#39;une des frontières d&#39;un cylindre en plastique tout en le tenant f auIRM avec les forceps. </li><li> Placer doucement le cylindre sur le côté apical de la muqueuse, au plus près de l&#39;un des bords de la bande que possible. </li><li> Pour donner le temps de la colle pour fixer fermement le cylindre sur le tissu, préparer la plaque de culture orgue centre-bien: Verser 850 ml ul-1 de milieu dans le centre de bien et de soutenir la grille métallique sur les bords du puits central de la plaque. </li><li> Coupez l&#39;excès de tissu à partir des frontières du cylindre à l&#39;aide de deux scalpels stériles comme avant. </li><li> Soulever légèrement le cylindre avec le tissu joint et placer le côté basolatéral de la grille métallique dans le centre de la plaque. </li></ol> 3. Stimulation <ol><li> Utilisez les stimuli de votre choix dans votre concentration préférée. </li><li> Appliquer un volume approprié au centre du cylindre en matière plastique, sans perturber le cylindre ou la surface d&#39;une muqueuse avec la pointe de pipette. Assurez-vous que votre volume choisi couvre uniformément la surface à l&#39;intérieur du cylindre. Envolumes dicated: Grand cylindre en plastique: 200 pi Moyen plastique cylindre: 100 pi Petit cylindre en plastique: 50 pi </li><li> Incuber jusqu&#39;à 3 heures dans un incubateur classique. </li></ol> * Si vous souhaitez incuber points de plus longues périodes, assurez-vous d&#39;utiliser un volume beaucoup plus petit de stimuli (10-20 pi) et de placer directement le tissu dans une atmosphère de 100% d&#39;O 2 dans la pression de 1 atm (voir 3.5) . <ol start="4"><li> Prenez le milieu avec les stimuli de la surface apicale du tissu et ne remplacent pas un milieu frais, parce que le tissu ne reçoit pas assez d&#39;O 2 si une épaisse couche de support sur ​​la face apicale empêche les échanges gazeux. Recouvrir la plaque. </li><li> Placer le tissu dans une atmosphère de 100% d&#39;O 2 à la pression de 1 atm. </li></ol> 4. La récolte <ol><li> Après 24 h de temps de culture totale (± 2,5 h) retirer délicatement le cylindre de etissu e avec l&#39;aide d&#39;un scalpel colle grattant doucement et de le stocker en fonction de l&#39;analyse souhaitée (fixe pour l&#39;immunohistochimie et / ou immunofluorescence, ou refroidissement rapide en N2 liquides pour l&#39;ARN purification et le profilage de l&#39;expression génique ou la purification des protéines et des dosages de Western blot ). </li><li> Récolter le milieu basolatéral de la sécrétion de cytokines profilage. Centrifuger à 8000 rpm pendant 7 min de débris granulés, transférer le surnageant dans un tube Eppendorf (alternativement aliquote) et stocker immédiatement à -20 ° C. </li></ol> * Si vous voulez garder surnageants de plus, les stocker à -80 ° C.

<ol>
	<li>Schuller, S., Lucas, M., Kaper, J. B., Giron, J. A., Phillips, 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=The+ex+vivo+response+of+human+intestinal+mucosa+to+enteropathogenic+Escherichia+coli+infection.">The ex vivo response of human intestinal mucosa to enteropathogenic Escherichia coli infection.</a> Cell. Microbiol. 11, 521-530 (2009).</li><li>Tsilingiri, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Probiotic+and+postbiotic+activity+in+health+and+disease:+comparison+on+a+novel+polarised+ex-vivo+organ+culture+model.">Probiotic and postbiotic activity in health and disease: comparison on a novel polarised ex-vivo organ culture model.</a> Gut. , (2012).</li><li>Tsilingiri, K., Rescigno, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Should+probiotics+be+tested+on+ex+vivo+organ+culture+models?.">Should probiotics be tested on ex vivo organ culture models?.</a> Gut Microbes. , (2012).</li><li>Mileti, E., Matteoli, G., Iliev, I. D., Rescigno, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+the+immunomodulatory+properties+of+three+probiotic+strains+of+Lactobacilli+using+complex+culture+systems:+prediction+for+in+vivo+efficacy.">Comparison of the immunomodulatory properties of three probiotic strains of Lactobacilli using complex culture systems: prediction for in vivo efficacy.</a> PLoS One. 4, e7056 (2009).</li><li>Cencic, A., Langerholc, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+cell+models+of+the+gut+and+their+applications+in+food+microbiology--a+review.">Functional cell models of the gut and their applications in food microbiology--a review.</a> Int. J. Food Microbiol. 141, S4-S14 (2010).</li><li>te Velde, A. A., Verstege, M. A., Hommes, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Critical+appraisal+of+the+current+practice+in+murine+TNBS-induced+colitis.">Critical appraisal of the current practice in murine TNBS-induced colitis.</a> Inflamm. Bowel Dis. 12, 995-999 (2006).</li><li>Senior, P. V., Pritchett, C. J., Sunter, J. P., Appleton, D. R., Watson, 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=Crypt+regeneration+in+adult+human+colonic+mucosa+during+prolonged+organ+culture.">Crypt regeneration in adult human colonic mucosa during prolonged organ culture.</a> J. Anat. 134, 459-469 (1982).</li><li>Browning, T. H., Trier, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Organ+culture+of+mucosal+biopsies+of+human+small+intestine.">Organ culture of mucosal biopsies of human small intestine.</a> J. Clin. Invest. 48, 1423-1432 (1969).</li><li>Besselink, M. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Probiotic+prophylaxis+in+predicted+severe+acute+pancreatitis:+a+randomised,+double-blind,+placebo-controlled+trial.">Probiotic prophylaxis in predicted severe acute pancreatitis: a randomised, double-blind, placebo-controlled trial.</a> Lancet. 371, 651-659 (2008).</li><li>Lakhdari, O., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+NF-kappaB+modulation+capabilities+within+human+intestinal+commensal+bacteria.">Identification of NF-kappaB modulation capabilities within human intestinal commensal bacteria.</a> J. Biomed. Biotechnol. 2011, 282356 (2011).</li></ol>

Aucun conflit d&#39;intérêt déclaré.

La nécessité pour les modèles physiologiquement pertinents sur lesquels les traitements pour la muqueuse intestinale humaine peuvent être valablement testées a longtemps été soulignée. De nombreux chercheurs ont identifié les artefacts et les défauts potentiels dans les deux cellules 5 et 6 modèles murins utilisés jusqu&#39;ici à cette fin. En effet, même si les données précliniques prometteurs sont souvent obtenus, ceux-ci se traduisent rarement à l&#39;avantage clinique significa...

<table border="1">
	<tbody>
		<tr>
			<td>Regeant</td>
			<td>Company</td>
			<td>Catalog No.</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>Reagents</td>
		</tr>
		<tr>
			<td>10X HBSS</td>
			<td>Eurocalne</td>
			<td>ECM4006XL</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Peni/Strepto</td>
			<td>Lonza</td>
			<td>DE17602E</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Gentamycin</td>
			<td>Gibco</td>
			<td>15750-037</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>DMEM</td>
			<td>Lonza</td>
			<td>BE12614</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>FBS-Na</td>
			<td>Gibco</td>
			<td>16000-044</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>100X ITS-X</td>
			<td>Gibco</td>
			<td>51500-056</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>EGF</td>
			<td>Tebu-bio</td>
			<td>100-15</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>L-Glutamine</td>
			<td>Lonza</td>
			<td>BE17605E</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Non essential aminoacids 100X</td>
			<td>Gibco</td>
			<td>11140-035</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>NaPyr</td>
			<td>Gibco</td>
			<td>11360-039</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>Materials</td>
		</tr>
		<tr>
			<td>Cloning cylinders 6x8 mm</td>
			<td>BellCo</td>
			<td>2090-00608</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Cloning cylinders 8x8 mm</td>
			<td>BellCo</td>
			<td>2090-0080</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Cloning cylinders 10x10 mm</td>
			<td>BellCo</td>
			<td>2090-01010</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Metal grids</td>
			<td>Home made</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Centre well organ culture plate</td>
			<td>BD Falcon</td>
			<td>353037</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Surgical glue (Vetbond)</td>
			<td>3M</td>
			<td>1469SB</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Oxygen Jars</td>
			<td>Home made</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Oxygen tanks</td>
			<td>Air Liquid Sanit&agrave;</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
	</tbody>
</table>

a novel method for the culture and polarized stimulation of human intestinal mucosa explants

Peu de modèles existent actuellement pour simuler de façon réaliste micro-environnement de la complexité humaine intestin, où une variété d&#39;interactions ont lieu. Homéostasie correcte dépend directement de ces interactions, comme elles façonnent une réponse immunologique toute tolérance inducteur contre des antigènes alimentaires tandis que dans le même temps de montage des réponses immunitaires efficaces contre les microbes pathogènes accidentellement ingéré avec les aliments. Homéostasie intestinale est préservée aussi à travers diverses interactions complexes entre le microbiote (y compris les souches bactériennes bénéfiques liés à des aliments) et l&#39;hôte, qui régulent l&#39;attachement / dégradation de mucus, la production de peptides antimicrobiens par la barrière épithéliale, et «l&#39;éducation» des cellules épithéliales »qui contrôlent le phénotype tolérogénique ou immunogène de cellules lymphoïdes uniques, gut-résidents» des populations. Ces interactions ont été jusqu&#39;à présent très difficile à reproduire avec des essais in vitroen utilisant soit des lignées de cellules en culture ou des cellules mononucléaires du sang périphérique. En outre, des modèles de souris diffèrent sensiblement dans les composants de la muqueuse intestinale (organisation de la couche de mucus, de la communauté des bactéries commensales) par rapport à l&#39;intestin humain. Ainsi, des études sur une variété de traitements soient traduits dans les cliniques pour les conditions importantes liées au stress ou pathologiques tels que le syndrome du côlon irritable, les maladies inflammatoires de l&#39;intestin ou de cancer colorectal ont été difficiles à réaliser. Pour répondre à ces questions, nous avons développé un nouveau système qui nous permet de stimuler des explants de muqueuse intestinale de l&#39;homme qui conservent leur in situ conditionné par le microbiote hôte et la réponse immunitaire, d&#39;une manière polarisée. Stimulation apicale polarisée est d&#39;une grande importance pour l&#39;issue de la réponse immunitaire provoquée. Il a été démontré à plusieurs reprises que les mêmes stimuli peuvent produire des réponses complètement différentes quand ils contournent la face apicale de l&#39;épidémie intestinalethelium, en stimulant les cellules épithéliales basolatéral ou d&#39;entrer en contact direct avec les composants de la lamina propria, le passage du phénotype de tolérogénique à immunogène et provoquant une inflammation excessive et inutile dans la région. Nous avons atteint stimulation polarisée par collage d&#39;une bouteille de cave qui délimitait la zone de stimulation sur la face apicale de la muqueuse comme cela sera décrit dans le protocole. Nous avons utilisé ce modèle pour examiner, entre autres, les effets différentiels des trois souches de lactobacilles différentes. Nous montrons que ce système modèle est très puissant pour évaluer les propriétés immunomodulatrices des probiotiques dans des conditions saines et la maladie.

Nous avons réussi à maintenir la muqueuse intestinale humaine saine et IBD en culture pendant au moins 24 heures en préservant le bien-être du tissu. Conformément à ses précédentes observations 1, cela n&#39;était possible que si la majorité du temps de culture (au moins 85% du total) a eu lieu en O 2, que le tissu n&#39;a pas survécu pendant 24 heures dans des incubateurs classiques (Figure 2). Nous avons aussi montré que les différentes réponses des explants peuvent...

Watch this Scientific Journal Video about A Novel Method for the Culture and Polarized Stimulation of Human Intestinal Mucosa Explants at JoVE.com

A Novel Method for the Culture and Polarized Stimulation of Human Intestinal Mucosa Explants

Nous introduisons une nouvelle méthode pour le maintien de la muqueuse intestinale humaine dans la culture et le suivi de la réponse à différents types de stimuli sur au moins 24 heures. Avec notre procédé, la polarité de la conservation du tissu, ce qui permet une stimulation physiologique par voie apicale.

Une nouvelle méthode pour la Culture et polarisé stimulation des explants de muqueuse intestinale de l&#39;homme

Few models currently exist to realistically simulate the complex human intestine's micro-environment, where a variety of interactions take place. Proper ...

a-novel-method-for-culture-polarized-stimulation-human-intestinal

Research

JoVE Journal

Biology

13.0K vues.  European Institute of Oncology. Nous introduisons une nouvelle méthode pour le maintien de la muqueuse intestinale humaine dans la culture et le suivi de la réponse à différents types de stimuli sur au moins 24 heures. Avec notre procédé, la polarité de la conservation du tissu, ce qui permet une stimulation physiologique par voie apicale.

Vidéo: A Novel Method for the Culture and Polarized Stimulation of Human Intestinal Mucosa Explants

Method for Culture of Early Chick Embryos ex vivo (New Culture)

The chick embryo is a valuable tool in the study of early embryonic development. Its transparency, accessibility and ease of manipulation, make it an ideal tool for studying  the formation and patterning of brain, neural tube, somite and heart primordia. Applications of chick embryo culture include electroporation of DNA or RNA constructs in order to analyze gene function, grafts of growth factor coated beads such as FGFs and BMPs , as well as whole mount in situ hybridization and immunohistochemistry. This video demonstrates the different steps in chick embryo culture; First, the embryo is explanted in saline. Then, the embryo is centered on a glass ring. The membranes surrounding the embryo are lifted along the walls of the ring. The ring is then placed in a culture dish containing a pool of albumine. The culture dish is sealed and placed in a humid chamber, where the embryo is cultured for up to 24 hrs. Finally, the embryo is removed from the ring, fixed and processed for further applications. A troubleshooting guide is also presented.

Method for Culture of Early Chick Embryos ex vivo New Culture

This video demonstrates New culture, a method by which chick embryos are cultured outside the egg for up to 24 hr. This method enables one to study early development (primitive streak to 14 som.), a period corresponding to E7-9 in mouse. Applications of this technique include electroporation, in situ hybridization and immunohistochemistry.

Méthode pour la culture d&#39;embryons de poulet Early ex vivo (Nouvelle Culture)

The chick embryo is a valuable tool in the study of early embryonic development. Its transparency, accessibility and ease of manipulation, make it an ...

Recherche

Biologie

Preparation and Culture of Rat Lens Epithelial Explants for Studying Terminal Differentiation

The anterior surface of the ocular lens is covered by a monolayer of epithelial cells, which proliferate in an annular zone underlying the ciliary body.  Following division, these cells migrate posteriorly, where FGF diffusing from the retina induces them to differentiate into a posterior array of elongated lens fiber cells, which compose the bulk of the lens.  Differentiation of lens epithelial cells into lens fibers can be induced in vitro by culturing explants of the central region of the anterior epithelium in the presence of FGF-2.  Explants are prepared from lenses of neonatal rats by removing the lens from the eye and grasping the lens capsule on the posterior side with dissecting tweezers.  The posterior capsule is then gently torn open and pressed down into the plastic bottom of a tissue culture dish. The peripheral regions of the explant are removed with a scalpel and the central area is then cultured in the presence of 100ng/ml FGF-2 for as long as 2-3 weeks, depending on the parameters to be studied.  Since epithelial cells in cultured explants differentiate in approximate synchrony over a period of days to weeks, the time course of signaling and gene expression can be determined using molecular, biochemical, and pharmacological techniques.  Immunofluorescence microscopy is a powerful adjunct to these methods as it demonstrates the subcellular localization of proteins of interest and can reveal the physiological consequences of experimental manipulations of signaling pathways.

Explants of the central region of rat lens epithelia differentiate synchronously when cultured in the presence of FGF-2. Immunofluorescence microscopy of such cultures can provides novel information about gene expression and signaling events associated with terminal differentiation.

Préparation et de la culture d&#39;explants Objectif Rat épithéliales pour l&#39;étude de la différenciation terminale

The anterior surface of the ocular lens is covered by a monolayer of epithelial cells, which proliferate in an annular zone underlying the ciliary body.  ...

The Method of Rodent Whole Embryo Culture using the Rotator-type Bottle Culture System

Whole embryo culture (WEC) technique has been developed in 1950's by New and his colleagues, and applied for developmental biology 1. Although development and growth of mammalian embryos are critically dependent on the function of the placenta, WEC technique allows us to culture mouse and rat embryos ex vivo condition during limited periods corresponding to midgestation stages during embryonic day (E) 6.5-E12.5 in the mouse or E8.5-E14.5 in the rat 2, 3, 4. In WEC, we can directly target desired areas of embryos using fine glass capillaries because embryos can be manipulated under the microscope. Therefore, rodent WEC is very useful technique when we want to study dynamic developmental processes of postimplanted mammalian embryos. Up to date, several types of WEC systems have been developed 1. Among those, the rotator-type bottle culture system is most popular and suitable for long-term culture of embryos at midgestation, i.e., after E9.5 and E11.5 in the mouse and rat, respectively 1. In this video protocol, we demonstrate our standard procedures of rat WEC after E12.5 using a refined model of the original rotator system, which was designed by New and Cockroft 5, 6, and introduce various applications of WEC technique for studies in mammalian developmental biology.

Whole embryo culture technique allows us to culture mouse and rat embryos ex vivo condition during limited periods corresponding to midgestation stages. In this video protocol, we demonstrate our standard procedures of rat whole embryo culture after E12.5 using the rotator-type bottle culture system.

La méthode de culture des embryons rongeurs entier en utilisant le système des rotateurs de type flacon de culture

Whole embryo culture (WEC) technique has been developed in 1950's by New and his colleagues, and applied for developmental biology 1. Although development ...

Blastomere Explants to Test for Cell Fate Commitment During Embryonic Development

Fate maps, constructed from lineage tracing all of the cells of an embryo, reveal which tissues descend from each cell of the embryo. Although fate maps are very useful for identifying the precursors of an organ and for elucidating the developmental path by which the descendant cells populate that organ in the normal embryo, they do not illustrate the full developmental potential of a precursor cell or identify the mechanisms by which its fate is determined. To test for cell fate commitment, one compares a cell's normal repertoire of descendants in the intact embryo (the fate map) with those expressed after an experimental manipulation. Is the cell's fate fixed (committed) regardless of the surrounding cellular environment, or is it influenced by external factors provided by its neighbors? Using the comprehensive fate maps of the Xenopus embryo, we describe how to identify, isolate and culture single cleavage stage precursors, called blastomeres. This approach allows one to assess whether these early cells are committed to the fate they acquire in their normal environment in the intact embryo, require interactions with their neighboring cells, or can be influenced to express alternate fates if exposed to other types of signals.

The fate of an individual embryonic cell can be influenced by inherited molecules and/or by signals from neighboring cells. Utilizing fate maps of the cleavage stage Xenopus embryo, single blastomeres can be identified for culture in isolation to assess the contributions of inherited molecules versus cell-cell interactions.

Les explants blastomères à l&#39;essai pour l&#39;engagement du destin cellulaire au cours du développement embryonnaire

Fate maps, constructed from lineage tracing all of the cells of an embryo, reveal  which tissues descend from each cell of the embryo.  Although fate maps ...

A Novel Ex vivo Culture Method for the Embryonic Mouse Heart

Developmental studies in the mouse are hampered by the inaccessibility of the embryo during gestation. Thus, protocols to isolate and culture individual organs of interest are essential to provide a method of both visualizing changes in development and allowing novel treatment strategies. To promote the long-term culture of the embryonic heart at late stages of gestation, we developed a protocol in which the excised heart is cultured in a semi-solid, dilute Matrigel. This substrate provides enough support to maintain the three-dimensional structure but is flexible enough to allow continued contraction. In brief, hearts are excised from the embryo and placed in a mixture of cold Matrigel diluted 1:1 with growth medium. After the diluted Matrigel solidifies, growth medium is added to the culture dish. Hearts excised as late as embryonic day 16.5 were viable for four days post-dissection. Analysis of the coronary plexus shows that this method does not disrupt coronary vascular development. Thus, we present a novel method for long-term culture of embryonic hearts.

A Novel Ex vivo Culture Method for the Embryonic Mouse Heart

Developmental studies in the mouse are hampered by the inaccessibility of the embryo during gestation. To promote the long-term culture of the embryonic heart at late stages of gestation, we developed a protocol in which the excised heart is cultured in a semi-solid, dilute Matrigel.

A Novel<em&gt; Ex vivo</em&gt; Méthode de la culture pour le embryonnaire Souris Coeur

Developmental studies in the mouse are hampered  by the inaccessibility of the embryo during gestation. Thus, protocols to  isolate and culture individual ...

The Slice Culture Method for Following Development of Tooth Germs In Explant Culture

Explant culture allows manipulation of developing organs at specific time points&#160;and is therefore an important method for the developmental biologist. For many organs it is difficult to access developing tissue to allow monitoring during ex vivo culture. The slice culture method allows access to tissue so that morphogenetic movements can be followed and specific cell populations can be targeted for manipulation or lineage tracing.
In this paper we describe a method of slice culture that has been very successful for culture of tooth germs in a range of species. The method provides excellent access to the tooth germs, which develop at a similar rate to that observed in vivo, surrounded by the other jaw tissues. This allows tissue interactions between the tooth and surrounding tissue to be monitored. Although this paper concentrates on tooth germs, the same protocol can be applied to follow development of a number of other organs, such as salivary glands, Meckel&#39;s cartilage, nasal glands, tongue, and ear.

Here we detail a method to culture tooth germs in mandible slices using a tissue chopper. This method allows unique access to the tooth during development, providing excellent opportunity for manipulation and lineage tracing, not available using more traditional culture methods.

La méthode la Culture Slice pour la suite du développement des germes de dents dans explantation Culture

Explant culture allows manipulation of developing organs at specific time points&#160;and is therefore an important method for the developmental ...

Subcloning Plus Insertion (SPI) - A Novel Recombineering Method for the Rapid Construction of Gene Targeting Vectors

Gene targeting refers to the precise modification of a genetic locus using homologous recombination. The generation of novel cell lines and transgenic mouse models using this method necessitates the construction of a &#8216;targeting&#8217; vector, which contains homologous DNA sequences to the target gene, and has for many years been a limiting step in the process. Vector construction can be performed in vivo in Escherichia coli cells using homologous recombination mediated by phage recombinases using a technique termed recombineering. Recombineering is the preferred technique to subclone the long homology sequences (>4kb) and various targeting elements including selection markers that are required to mediate efficient allelic exchange between a targeting vector and its cognate genomic locus. Typical recombineering protocols follow an iterative scheme of step-wise integration of the targeting elements and require intermediate purification and transformation steps. Here, we present a novel recombineering methodology of vector assembly using a multiplex approach. Plasmid gap repair is performed by the simultaneous capture of genomic sequence from mouse Bacterial Artificial Chromosome libraries and the insertion of dual bacterial and mammalian selection markers. This subcloning plus insertion method is highly efficient and yields a majority of correct recombinants. We present data for the construction of different types of conditional gene knockout, or knock-in, vectors and BAC reporter vectors that have been constructed using this method. SPI vector construction greatly extends the repertoire of the recombineering toolbox and provides a simple, rapid and cost-effective method of constructing these highly complex vectors.

Subcloning Plus Insertion SPI - A Novel Recombineering Method for the Rapid Construction of Gene Targeting Vectors

Gene targeting methodologies can be used to generate transgenic mice with knockout, knock-in and tagged alleles. Here, we describe an improved method of recombineering in E. coli, that we term &#8216;subcloning plus insertion&#8217;, which can be used to generate custom gene targeting vectors rapidly.

Sous-clonage plus insertion (SPI) - Un Recombineering nouveau procédé pour la construction rapide de ciblage de gène Vecteurs

Gene targeting refers to the precise modification of a genetic locus using homologous recombination. The generation of novel cell lines and transgenic ...

A Protocol for Lentiviral Transduction and Downstream Analysis of Intestinal Organoids

Intestinal crypt-villus structures termed organoids, can be kept in sustained culture three dimensionally when supplemented with the appropriate growth factors. Since organoids are highly similar to the original tissue in terms of homeostatic stem cell differentiation, cell polarity and presence of all terminally differentiated cell types known to the adult intestinal epithelium, they serve as an essential resource in experimental research on the epithelium. The possibility to express transgenes or interfering RNA using lentiviral or retroviral vectors in organoids has increased opportunities for functional analysis of the intestinal epithelium and intestinal stem cells, surpassing traditional mouse transgenics in speed and cost. In the current video protocol we show how to utilize transduction of small intestinal organoids with lentiviral vectors illustrated by use of doxycylin inducible transgenes, or IPTG inducible short hairpin RNA for overexpression or gene knockdown. Furthermore, considering organoid culture yields minute cell counts that may even be reduced by experimental treatment, we explain how to process organoids for downstream analysis aimed at quantitative RT-PCR, RNA-microarray and immunohistochemistry. Techniques that enable transgene expression and gene knock down in intestinal organoids contribute to the research potential that these intestinal epithelial structures hold, establishing organoid culture as a new standard in cell culture.

In this video protocol we give a step by step explanation of lentiviral transduction in organoids of primary intestinal epithelium and of processing and downstream analysis of these cultures by quantitative RT-PCR, RNA-microarray and immunohistochemistry.

Un protocole pour Lentiviral transduction et analyse aval de intestinale organoïdes

Intestinal crypt-villus structures termed organoids, can be kept in sustained culture three dimensionally when supplemented with the appropriate growth ...

A Method for Selecting Structure-switching Aptamers Applied to a Colorimetric Gold Nanoparticle Assay

Small molecules provide rich targets for biosensing applications due to their physiological implications as biomarkers of various aspects of human health and performance. Nucleic acid aptamers have been increasingly applied as recognition elements on biosensor platforms, but selecting aptamers toward small molecule targets requires special design considerations. This work describes modification and critical steps of a method designed to select structure-switching aptamers to small molecule targets. Binding sequences from a DNA library hybridized to complementary DNA capture probes on magnetic beads are separated from nonbinders via a target-induced change in conformation. This method is advantageous because sequences binding the support matrix (beads) will not be further amplified, and it does not require immobilization of the target molecule. However, the melting temperature of the capture probe and library is kept at or slightly above RT, such that sequences that dehybridize based on thermodynamics will also be present in the supernatant solution. This effectively limits the partitioning efficiency (ability to separate target binding sequences from nonbinders), and therefore many selection rounds will be required to remove background sequences. The reported method differs from previous structure-switching aptamer selections due to implementation of negative selection steps, simplified enrichment monitoring, and extension of the length of the capture probe following selection enrichment to provide enhanced stringency. The selected structure-switching aptamers are advantageous in a gold nanoparticle assay platform that reports the presence of a target molecule by the conformational change of the aptamer. The gold nanoparticle assay was applied because it provides a simple, rapid colorimetric readout that is beneficial in a clinical or deployed environment. Design and optimization considerations are presented for the assay as proof-of-principle work in buffer to provide a foundation for further extension of the work toward small molecule biosensing in physiological fluids.

A protocol is provided to select structure-switching aptamers for small molecule targets based on a tunable stringency magnetic bead selection method. Aptamers selected with structure-switching properties are beneficial for assays that require a conformational change to signal the presence of a target, such as the described gold nanoparticle assay.

Une méthode de sélection aptamères Structure commutation Appliqué à un colorimétrique Or nanoparticules Assay

Small molecules provide rich targets for biosensing applications due to their physiological implications as biomarkers of various aspects of human health ...

Cryosectioning Method for Microdissection of Murine Colonic Mucosa

The colonic mucosal tissue provides a vital barrier to luminal antigens. This barrier is composed of a monolayer of simple columnar epithelial cells. The colonic epithelium is dynamically turned over and epithelial cells are generated in the stem cell containing crypts of Lieberk&#252;hn. Progenitor cells produced in the crypt-bases migrate toward the luminal surface, undergoing a process of cellular differentiation before being shed into the gut lumen. In order to study these processes at the molecular level, we have developed a simple method for the microdissection of two spatially distinct regions of the colonic mucosa; the proliferative crypt zone, and the differentiated surface epithelial cells. Our objective is to isolate specific crypt and surface epithelial cell populations from mouse colonic mucosa for the isolation of RNA and protein.

Here we describe a simple method for the isolation of spatially distinct murine colonic epithelial surface cells from the underlying crypt-base cells.

Cryosectioning Méthode de microdissection de murin côlon Muqueuse

The colonic mucosal tissue provides a vital barrier to luminal antigens. This barrier is composed of a monolayer of simple columnar epithelial cells. The ...