Gostaríamos de agradecer a Andrea Portbury para a leitura crítica do manuscrito e do NIH (Grant # R01HL061656) para apoio financeiro.

1. Extirpando os corações embrionárias <ol><li> Sacrificá um rato timed-grávida no dia embrionário desejado usando uma técnica de eutanásia aprovado. Todos os experimentos foram aprovados pelo Institutional Animal Care e do Comitê Use da Universidade da Carolina do Norte em Chapel Hill. </li><li> Liberalmente pulverizar a fêmea com etanol 70% antes da dissecação. Abra cavidade abdominal da fêmea para recuperar e impostos especiais de consumo do corno uterino. </li><li> Coloque a trompa uterina de uma placa de Petri contendo a frio 1x salina tamponada com fosfato (PBS) e lavagem conforme necessário. Cortar abrir o corno uterino através da linha média para expor os sacos embrionários em anexo. </li><li> Cortar abrir um saco embrionário e recuperar um embrião. Coloque o embrião de uma segunda placa de Petri com o frio PBS. Retorne a placa de Petri com o corno uterino em gelo. </li><li> Decapitar o embrião para melhorar o acesso à parede torácica. Se a genotipagem é necessário, remover e guardar a cauda num tubo Eppendorf colocada em gelo. </li><li> Com oembrião em suas costas, cortou a parede torácica para visualizar o coração e os pulmões. Dependendo da fase, a parede torácica pode ser transparente. </li><li> Levante cuidadosamente o coração usando uma pinça e cortar os vasos abaixo. Em seguida, corte acima dos grandes vasos para libertar o coração. Se necessário, remover os tecidos estranhos. </li><li> Colocar o coração num poço de um prato de 24 poços cheios com PBS frio e colocar o prato em gelo. </li><li> Repita os passos anteriores até que os corações foram retirados de todos os embriões. </li></ol> 2. Cultura Set-up <ol><li> Num capuz laminar, combinar Matrigel frio e o meio de cultura desejada (por exemplo, 10% de soro fetal bovino (FBS) em Meio Eagle Modificado por Dulbecco (DMEM)) numa proporção de 1:1. Não pré-aquecer o meio de cultura. </li><li> Mantendo o Matrigel diluído em gelo, pipeta 500-1.000 ul da solução diluída para um poço de uma placa de cultura de 24 poços que também é mantido em gelo. </li><li> Na capa, escolha com cuidado e coloque o excisadascoração num poço da placa de cultura de Matrigel contendo mantendo a placa de cultura em gelo. </li><li> Se a orientação do coração encaixado é crucial: Liberalmente pulverizar um microscópio invertido e o espaço circundante com etanol a 70%. Na capa, colocar o coração retirado de uma cavidade da placa de cultura de Matrigel contendo, enquanto ainda no gelo. Em seguida, coloca a placa em um microscópio e orientar rapidamente o coração excisado como o Matrigel começa a solidificar. </li><li> Colocar a placa de cultura de 37 ° C humidificado incubadora (5% de CO 2) e permitir que o Matrigel para solidificar durante aproximadamente 30 min. </li><li> Adicionar 1 ml de meio de cultura pré-aquecido a cada poço contendo um coração. </li><li> Corações podem permanecer em cultura durante pelo menos quatro dias. A alteração do meio de cultura de dois em dois dias é recomendado. </li></ol> 3. Fixação e Visualização <ol><li> Se se desejar, adicionar um corante fluorescente em células vivas (por exemplo, Syto-16) para visualizar o coração vivo. Fotografia serálimitado ao lado do coração, que é visível com base na posição em que foi incorporado. </li><li> Se as análises pós-cultura (por exemplo, toda a imagem de montagem ou o corte) será realizada, remova o meio de cultura e substituir com frio formaldeído 4%. Coloque o prato no gelo por 30 min. </li><li> Após o formaldeído frio e gelo promover a dissolução do Matrigel, substituir o fixador (e Matrigel) com formaldeído fresco e corrigir corações durante a noite a 4 ° C. </li><li> Lave os corações com tampão (eg PBS ou Tris) e armazenar a 4 ° C até as análises. </li></ol>

<ol>
	<li>Tu, S., Chi, N. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Zebrafish+models+in+cardiac+development+and+congenital+heart+birth+defects.">Zebrafish models in cardiac development and congenital heart birth defects.</a> Differentiation. 84, 4-16 (2012).</li><li>Lavine, K. J., 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=Fibroblast+growth+factor+signals+regulate+a+wave+of+Hedgehog+activation+that+is+essential+for+coronary+vascular+development.">Fibroblast growth factor signals regulate a wave of Hedgehog activation that is essential for coronary vascular development.</a> Genes Dev. 20, 1651-1666 (2006).</li><li>Red-Horse, K., Ueno, H., Weissman, I. L., Krasnow, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coronary+arteries+form+by+developmental+reprogramming+of+venous+cells.">Coronary arteries form by developmental reprogramming of venous cells.</a> Nature. 464, 549-553 (2010).</li><li>Stuckmann, I., Evans, S., Lassar, A. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Erythropoietin+and+retinoic+acid,+secreted+from+the+epicardium,+are+required+for+cardiac+myocyte+proliferation.">Erythropoietin and retinoic acid, secreted from the epicardium, are required for cardiac myocyte proliferation.</a> Dev. Biol. 255, 334-349 (2003).</li><li>Zhang, J., 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=The+FGF-BMP+signaling+axis+regulates+outflow+tract+valve+primordium+formation+by+promoting+cushion+neural+crest+cell+differentiation.">The FGF-BMP signaling axis regulates outflow tract valve primordium formation by promoting cushion neural crest cell differentiation.</a> Circ. Res. 107, 1209-1219 (2010).</li><li>Pillekamp, F., 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=Establishment+and+characterization+of+a+mouse+embryonic+heart+slice+preparation.">Establishment and characterization of a mouse embryonic heart slice preparation.</a> Cellular Physiology and Biochemistry: international journal of experimental cellular physiology, biochemistry, and pharmacology. 16, 127-132 (2005).</li><li>Habeler, W., Peschanski, M., Monville, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Organotypic+heart+slices+for+cell+transplantation+and+physiological+studies.">Organotypic heart slices for cell transplantation and physiological studies.</a> Organogenesis. 5, 62-66 (2009).</li><li>Janssen, P. M., Lehnart, S. E., Prestle, J., Hasenfuss, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preservation+of+contractile+characteristics+of+human+myocardium+in+multi-day+cell+culture.">Preservation of contractile characteristics of human myocardium in multi-day cell culture.</a> J. Mol. Cell Cardiol. 31, 1419-1427 (1999).</li><li>Brandenburger, M., 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=Organotypic+slice+culture+from+human+adult+ventricular+myocardium.">Organotypic slice culture from human adult ventricular myocardium.</a> Cardiovasc. Res. 93, 50-59 (2012).</li><li>Weaver, M., Dunn, N. R., Hogan, B. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bmp4+and+Fgf10+play+opposing+roles+during+lung+bud+morphogenesis.">Bmp4 and Fgf10 play opposing roles during lung bud morphogenesis.</a> Development. , 127-2695 (2000).</li><li>Viragh, S., Challice, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+origin+of+the+epicardium+and+the+embryonic+myocardial+circulation+in+the+mouse.">The origin of the epicardium and the embryonic myocardial circulation in the mouse.</a> Anat. Rec. 201, 157-168 (1981).</li><li>Kirby, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Cardiac Development. , (2007).</li><li>Arima, S., 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=Angiogenic+morphogenesis+driven+by+dynamic+and+heterogeneous+collective+endothelial+cell+movement.">Angiogenic morphogenesis driven by dynamic and heterogeneous collective endothelial cell movement.</a> Development. 138, 4763-4776 (2011).</li></ol>

Os autores declaram que não têm interesses financeiros concorrentes.

O atual sistema de cultura apresenta vantagens significativas para os estudos cardíacas embrionárias de camundongos. Este sistema de cultura preserva a contractilidade do miocárdio e do plexo coronária, com sinais limitadas de necrose, mesmo após quatro dias de cultura. Além disso, a matriz semi-sólida proporciona suporte suficiente para manter a morfologia tridimensional do coração em desenvolvimento, permitindo flexibilidade de contrato e também para segurar esferas revestidas no lugar durante a cultura. Ape...

Nos últimos anos, o ratinho transgénico tem sido o sistema modelo para o estudo predominante de desenvolvimento de defeitos cardíacos. No entanto, outros organismos modelo, tal como o peixe-zebra, provaram ter vantagens significativas sobre o rato. Três importantes vantagens do peixe-zebra são a colocação externa de ovos, para facilidade de acesso para os embriões, a transparência óptica dos embriões, o que permite a fácil visualização do desenvolvimento cardíaco e a facilidade de aplicação de pequenas tratamentos moleculares para modular o desenvolvimento do embrião 1. Assim, o desenvolvimento de uma técnica de cultura que permitiu o crescimento ex utero de um dos órgãos embrionários seria ignorar, pelo menos em parte, as limitações actualmente experimentado por investigadores que estudam processos de desenvolvimento de ratinhos transgénicos. Sistemas de cultura ex vivo cardíacos foram desenvolvidos tanto em embrião do pinto e do rato que permitem que o tratamento com pequenas moléculas e análise de como differentes regiões do coração comunicar 2-6. Para a cultura do coração de rato inteiro, corações feita a partir de embriões até embrionária (E), 12,5 de idade podem ser colocados em meio de cultura com ou sem balançar 2,3,5. Usando esta técnica, os corações embrionários foram incubadas com êxito para a equivalência de E13.5, e os corações foram cultivadas com agitação foi mantida enquanto três dias (a partir de E10.5) 3. No entanto, não existem estudos têm relatado a cultura de sucesso de corações de embriões mais velhos. Da mesma forma, as experiências de resgate foram limitadas a aplicação do agente terapêutico a nível mundial para o meio de cultura 2. Um sistema de cultura fatia, em que corações são excisadas, incorporado, e seccionados usando um vibratome, também tem sido utilizada para ambos os corações mais jovens, como E12.5 corações de rato e Hamburger-Hamilton estágio 36 (cerca de E16 no mouse) bico corações 2,4,6, ou mais corações, como o pós-natal e do rato adulto hearts e corações humanos adultos 7,8. Enquanto as análises embrionárias têm tipicamente utilizado de espessura 150 mícrons 2,4, espessura de corte pode ser um grande como 500 mM, sem evidências de privação de oxigênio 8. Estas culturas foram mantidas de fatia, enquanto dois meses em cultura, com a maioria das fatias mantendo contractilidade ao longo deste período de 9. Em comparação com estudos em cardiomiócitos isoladas, estas culturas fatia permitir a co-cultura de cardiomiócitos com os seus tipos de células vizinhas e fornecem um método útil para a análise ex vivo. Contudo, estas culturas requerem mais elaborada configurar do que simplesmente colocar o coração no meio de cultura (por exemplo, incorporando o coração vivo para o seccionamento num vibratome), e qualquer análise é, obviamente, limitada a parte do coração no interior da secção. Dadas as limitações descritas acima para a cultura de coração de rato embrionárias ea riqueza de camundongos transgênicos available para o estudo, foi desenvolvido um sistema de cultura do coração de rato ex vivo semelhante a um sistema de cultura ex vivo de pulmão desenvolvidas por Weaver, et al 10 O nosso sistema de cultura. permite a cultura a longo prazo e a visualização da circulação coronária remodelação corações inteiros dentro embrionárias de ratinho. Além disso, a utilização de grânulos de Matrigel permite ser mantido no lugar perto do coração, proporcionando assim um tratamento localizado de agentes terapêuticos. Estas experiências podem ser realizadas em momentos diferentes de desenvolvimento para comparar o efeito de um determinado tratamento com um processo tal como a formação da artéria coronária. Porque as moléculas pequenas podem difundir através de Matrigel, este sistema de cultura pode também ser utilizada para a cultura regiões dissecadas do coração perto uns dos outros para determinar se os contactos célula-célula específicos são necessários para certos processos do desenvolvimento ou se parácrinos sinalização de uma região para a outra é necessário. Este sistema de culturaé relativamente simples e, ao contrário do sistema de cultura fatia, faz uso de reagentes básicos da cultura e set-ups que estão disponíveis na maioria dos laboratórios. Em resumo, os corações são excisados ​​de embriões cultivados em Matrigel diluído, o qual proporciona um suporte semi-sólido. Este apoio é suficiente para manter a morfologia tridimensional do coração, ao mesmo tempo, permitindo que o coração contrato. Usando este sistema, corações inteiros de embriões de ratos mais velhos (E14.5, E16.5) podem ser mantidas em cultura durante quatro dias. Todo o plexo coronário é mantido, ao contrário das culturas de fatia, de modo quaisquer sinais de sinalização que ocorrem a partir de diferentes regiões do coração continuar presente. Além disso, corantes fluorescentes em células vivas, podem permear o Matrigel para permitir a visualização do coração, ao vivo, e os grânulos de proteína conjugada pode ser colocado perto do coração para proporcionar uma fonte de sinalização localizada. Juntos, esses benefícios fazem desta técnica um método ideal para o estudo de processos de desenvolvimento no embryoncoração do mouse ic.

<table border="1">
<tbody>
 <tr>
 <td></td>
 <td></td>
 <td></td>
 <td>REAGENTS</td>
 </tr>
 <tr>
 <td>Timed-pregnant mice</td>
 <td></td>
 <td></td>
 <td>To be dissected at the embryonic stage of interest</td>
 </tr>
 <tr>
 <td>PBS (1x)</td>
 <td></td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>DMEM</td>
 <td>Cellgro </td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>FBS</td>
 <td>Sigma-Aldrich </td>
 <td>F2442 </td>
 <td></td>
 </tr>
 <tr>
 <td>Growth factor-reduced Matrigel</td>
 <td>BD Bioscience </td>
 <td>356231 </td>
 <td></td>
 </tr>
 <tr>
 <td>Syto-16</td>
 <td>Invitrogen </td>
 <td>S7578 </td>
 <td>Used as directed in 13 </td>
 </tr>
 <tr>
 <td>24-well culture plate</td>
 <td>Fisher Scientific</td>
 <td>07-200-84</td>
 <td></td>
 </tr>
 <tr>
 <td></td>
 <td></td>
 <td></td>
 <td>EQUIPMENT</td>
 </tr>
 <tr>
 <td>Stereoscopic microscope</td>
 <td>Nikon </td>
 <td>SMZ645</td>
 <td></td>
 </tr>
 <tr>
 <td>Cell culture incubator</td>
 <td>Thermo </td>
 <td>3110 </td>
 <td></td>
 </tr>
</tbody>
 </table>

a novel ex vivo culture method for the embryonic mouse heart

Estudos de desenvolvimento no rato são dificultados pela inacessibilidade do embrião durante a gestação. Assim, os protocolos de cultura e para isolar os órgãos individuais de interesse são essenciais para proporcionar um método de visualização de ambas as alterações no desenvolvimento e permitindo que novas estratégias de tratamento. Para promover a cultura de longo prazo do coração embrionário em fases tardias da gestação, foi desenvolvido um protocolo no qual o coração excisado é cultivada num Matrigel semi-sólido, diluída. Este substrato proporciona suporte suficiente para manter a estrutura tridimensional, mas é suficientemente flexível para permitir a contracção continuada. Em resumo, os corações são cortados a partir do embrião e colocado numa mistura de Matrigel frio diluído 1:1 com meio de crescimento. Após o Matrigel diluída solidifica, meio de crescimento é adicionado à placa de cultura. Corações excisadas tão tarde como dia embrionário 16,5 eram viáveis ​​por quatro dias após a dissecação. A análise do plexo coronária mostra que este método não fazperturbar o desenvolvimento vascular coronária. Assim, apresenta-se um novo método para a cultura de longo prazo de corações embrionárias.

Utilizando esta técnica, o coração mantém a sua morfologia tridimensional permanece viável e, como indicado por contracções contínuas filme (1). Essas contrações são consistentemente mais proeminente nos átrios do que nos ventrículos. Após a cultura, os corações podem ser fixadas e processadas para histologia e imuno-histoquímica ou para examinar a expressão do marcador específico ou estruturas. Figura 1A mostra a base dos ventrículos e grandes artérias do coração...

Watch this Scientific Journal Video about A Novel Ex vivo Culture Method for the Embryonic Mouse Heart at JoVE.com

A Novel Ex vivo Culture Method for the Embryonic Mouse Heart

Estudos de desenvolvimento no rato são dificultados pela inacessibilidade do embrião durante a gestação. Para promover a cultura de longo prazo do coração embrionário em fases tardias da gestação, foi desenvolvido um protocolo no qual o coração excisado é cultivada num Matrigel semi-sólido, diluída.

A Novel<em&gt; Ex vivo</em&gt; Método de Cultura para o Rato coração embrionário

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

a-novel-ex-vivo-culture-method-for-the-embryonic-mouse-heart

Research

JoVE Journal

Biology

A Novel Ex vivo Culture Method for the Embryonic Mouse Heart

13.2K visualizações.  University of North Carolina at Chapel Hill. Estudos de desenvolvimento no rato são dificultados pela inacessibilidade do embrião durante a gestação. Para promover a cultura de longo prazo do coração embrionário em fases tardias da gestação, foi desenvolvido um protocolo no qual o coração excisado é cultivada num Matrigel semi-sólido, diluída.

Vídeo: A Novel Ex vivo Culture Method for the Embryonic Mouse Heart

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.

Método para a Cultura de Embriões início pintainho ex vivo (Nova Cultura)

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

Biologia

In utero and ex vivo Electroporation for Gene Expression in Mouse Retinal Ganglion Cells

The retina and its sole output neuron, the retinal ganglion cell (RGC), comprise an excellent model in which to examine biological questions such as cell differentiation, axon guidance, retinotopic organization and synapse formation[1]. One drawback is the inability to efficiently and reliably manipulate gene expression in RGCs in vivo, especially in the otherwise accessible murine visual pathways. Transgenic mice can be used to manipulate gene expression, but this approach is often expensive, time consuming, and can produce unwanted side effects. In chick, in ovo electroporation is used to manipulate gene expression in RGCs for examining retina and RGC development. Although similar electroporation techniques have been developed in neonatal mouse pups[2], adult rats[3], and embryonic murine retinae in vitro[4], none of these strategies allow full characterization of RGC development and axon projections in vivo. To this end, we have developed two applications of electroporation, one in utero and the other ex vivo, to specifically target embryonic murine RGCs[5, 6]. 
With in utero retinal electroporation, we can misexpress or downregulate specific genes in RGCs and follow their axon projections through the visual pathways in vivo, allowing examination of guidance decisions at intermediate targets, such as the optic chiasm, or at target regions, such as the lateral geniculate nucleus. Perturbing gene expression in a subset of RGCs in an otherwise wild-type background facilitates an understanding of gene function throughout the retinal pathway. Additionally, we have developed a companion technique for analyzing RGC axon growth in vitro. We electroporate embryonic heads ex vivo, collect and incubate the whole retina, then prepare explants from these retinae several days later. Retinal explants can be used in a variety of in vitro assays in order to examine the response of electroporated RGC axons to guidance cues or other factors. In sum, this set of techniques enhances our ability to misexpress or downregulate genes in RGCs and should greatly aid studies examining RGC development and axon projections.

In utero and ex vivo Electroporation for Gene Expression in Mouse Retinal Ganglion Cells

Here we present two techniques for manipulating gene expression in murine retinal ganglion cells (RGCs) by in utero and ex vivo electroporation. These techniques enable one to examine how alterations in gene expression affect RGC development, axon guidance, and functional properties.

No útero e ex eletroporação in vivo para Expressão Gênica em células ganglionares da retina do rato

The retina and its sole output neuron, the retinal ganglion cell (RGC), comprise an excellent model in which to examine biological questions such as cell ...

Mouse Embryonic Lung Culture, A System to Evaluate the Molecular Mechanisms of Branching

Lung primordial specification as well as branching morphogenesis, and the formation of various pulmonary cell lineages requires a specific interaction of the lung endoderm with its surrounding mesenchyme and mesothelium. Lung mesenchyme has been shown to be the source of inductive signals for lung branching morphogenesis. Epithelial-mesenchymal-mesothelial interactions are also critical to embryonic lung morphogenesis. Early embryonic lung organ culture is a very useful system to study epithelial-mesenchymal interactions. Both epithelial and mesenchymal morphogenesis proceeds under specific conditions that can be readily manipulated in this system (in the absence of maternal influence and blood flow). More importantly this technique can be readily done in a serumless, chemically defined culture media. Gain and loss of function can be achieved using expressed proteins, recombinant viral vectors and/or analysis of transgenic mouse strains, antisense RNA, as well as RNA interference gene knockdown.

Early embryonic lung organ culture is a very useful system to study epithelial-mesenchymal interactions. Both epithelial and mesenchymal morphogenesis proceeds under specific conditions that can be readily manipulated in this system.

Cultura do mouse pulmão embrionário, um sistema para avaliar os mecanismos moleculares de Ramificação

Lung primordial specification as well as branching morphogenesis, and the formation of various pulmonary cell lineages requires a specific interaction of ...

A System for ex vivo Culturing of Embryonic Pancreas

The pancreas controls vital functions of our body, including the production of digestive enzymes and regulation of blood sugar levels1. Although in the past decade many studies have contributed to a solid foundation for understanding pancreatic organogenesis, important gaps persist in our knowledge of early pancreas formation2. A complete understanding of these early events will provide insight into the development of this organ, but also into incurable diseases that target the pancreas, such as diabetes or pancreatic cancer. Finally, this information will generate a blueprint for developing cell-replacement therapies in the context of diabetes.
 During embryogenesis, the pancreas originates from distinct embryonic outgrowths of the dorsal and ventral foregut endoderm at embryonic day (E) 9.5 in the mouse embryo3,4. Both outgrowths evaginate into the surrounding mesenchyme as solid epithelial buds, which undergo proliferation, branching and differentiation to generate a fully mature organ2,5,6. Recent evidences have suggested that growth and differentiation of pancreatic cell lineages, including the insulin-producing &beta;-cells, depends on proper tissue-architecture, epithelial remodeling and cell positioning within the branching pancreatic epithelium7,8. However, how branching morphogenesis occurs and is coordinated with proliferation and differentiation in the pancreas is largely unknown. This is in part due to the fact that current knowledge about these developmental processes has relied almost exclusively on analysis of fixed specimens, while morphogenetic events are highly dynamic.
 Here, we report a method for dissecting and culturing mouse embryonic pancreatic buds ex vivo on glass bottom dishes, which allow direct visualization of the developing pancreas (Figure 1). This culture system is ideally devised for confocal laser scanning microscopy and, in particular, live-cell imaging. Pancreatic explants can be prepared not only from wild-type mouse embryos, but also from genetically engineered mouse strains (e.g. transgenic or knockout), allowing real-time studies of mutant phenotypes. Moreover, this ex vivo culture system is valuable to study the effects of chemical compounds on pancreatic development, enabling to obtain quantitative data about proliferation and growth, elongation, branching, tubulogenesis and differentiation. In conclusion, the development of an ex vivo pancreatic explant culture method combined with high-resolution imaging provides a strong platform for observing morphogenetic and differentiation events as they occur within the developing mouse embryo.

A System for ex vivo Culturing of Embryonic Pancreas

Here, we describe a method for isolation, culture and manipulation of mouse embryonic pancreas. This represents an excellent ex vivo system for studying various aspects of pancreatic development, including morphogenesis, differentiation and growth. Pancreatic bud explants can be cultured for several days and used in a range of different applications, including whole-mount immunofluorescence and live imaging.

Um Sistema de<em&gt; Ex vivo</em&gt; A cultura de Pâncreas embrionárias

The pancreas controls vital functions of our body,  including the production of digestive enzymes and regulation of blood sugar  levels1. Although in the ...

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

Few models currently exist to realistically simulate the complex human intestine's micro-environment, where a variety of interactions take place. Proper homeostasis directly depends on these interactions, as they shape an entire immunological response inducing tolerance against food antigens while at the same time mounting effective immune responses against pathogenic microbes accidentally ingested with food.
Intestinal homeostasis is preserved also through various complex interactions between the microbiota (including food-associated beneficial bacterial strains) and the host, that regulate the attachment/degradation of mucus, the production of antimicrobial peptides by the epithelial barrier, and the "education" of epithelial cells' that controls the tolerogenic or immunogenic phenotype of unique, gut-resident lymphoid cells' populations. These interactions have been so far very difficult to reproduce with in vitro assays using either cultured cell lines or peripheral blood mononuclear cells. In addition, mouse models differ substantially in components of the intestinal mucosa (mucus layer organization, commensal bacteria community) with respect to the human gut. Thus, studies of a variety of treatments to be brought in the clinics for important stress-related or pathological conditions such as irritable bowel syndrome, inflammatory bowel disease or colorectal cancer have been difficult to carry out.
To address these issues, we developed a novel system that enables us to stimulate explants of human intestinal mucosa that retain their in situ conditioning by the host microbiota and immune response, in a polarized fashion. Polarized apical stimulation is of great importance for the outcome of the elicited immune response. It has been repeatedly shown that the same stimuli can produce completely different responses when they bypass the apical face of the intestinal epithelium, stimulating epithelial cells basolaterally or coming into direct contact with lamina propria components, switching the phenotype from tolerogenic to immunogenic and causing unnecessary and excessive inflammation in the area.
We achieved polarized stimulation by gluing a cave cylinder which delimited the area of stimulation on the apical face of the mucosa as will be described in the protocol. We used this model to examine, among others, differential effects of three different Lactobacilli strains. We show that this model system is very powerful to assess the immunomodulatory properties of probiotics in healthy and disease conditions.

We introduce a novel method for the maintenance of human intestinal mucosa in culture and monitoring of the response to various types of stimuli over at least 24 hrs. With our method, the polarity of the tissue is maintained, allowing for a physiological stimulation via the apical route.

Um novo método para a Cultura e polarizada Estimulação dos Humanos explantes mucosa intestinal

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

Isolation of Embryonic Ventricular Endothelial Cells

Cell culture has greatly enhanced our ability to assess individual populations of cells under myriad culture conditions. While immortalized cell lines offer significant advantages for their ease of use, these cell lines are unavailable for all potential cell types. By isolating primary cells from a specific region of interest, particularly from a transgenic mouse, more nuanced studies can be performed. The basic technique involves dissecting the organ or partial organ of interest (e.g. the heart or a specific region of the heart) and dissociating the organ to single cells. These cells are then incubated with magnetic beads conjugated to an antibody that recognizes the cell type of interest. The cells of interest can then be isolated with the use of a magnet, with a short trypsin incubation dissociating the cells from the beads. These isolated cells can then be cultured and analyzed as desired. This technique was originally designed for adult mouse organs but can be easily scaled down for use with embryonic organs, as demonstrated herein. Because our interest is in the developing coronary vasculature, we wanted to study this population of cells during specific embryonic stages. Thus, the original protocol had to be modified to be compatible with the small size of the embryonic ventricles and the low potential yield of endothelial cells at these developmental stages. Utilizing this scaled-down approach, we have assessed coronary plexus remodeling in transgenic embryonic ventricular endothelial cells.

Primary cell culture is a useful technique for analyzing specific populations of cells, particularly from transgenic mouse embryos at specific developmental stages. Herein, embryonic ventricles are dissected and dissociated, and antibody-conjugated beads recognize and separate out the endothelial cells for further analysis.

Isolamento de Células Embrionárias ventriculares endoteliais

Cell culture has greatly enhanced our ability to assess individual populations of cells under myriad culture conditions. While immortalized cell lines ...

Mouse Embryonic Development in a Serum-free Whole Embryo Culture System

Mid-gestation stage mouse embryos were cultured utilizing a serum-free culture medium prepared from commercially available stem cell media supplements in an oxygenated rolling bottle culture system. Mouse embryos at E10.5 were carefully isolated from the uterus with intact yolk sac and in a process involving precise surgical maneuver the embryos were gently exteriorized from the yolk sac while maintaining the vascular continuity of the embryo with the yolk sac. Compared to embryos prepared with intact yolk sac or with the yolk sac removed, these embryos exhibited superior survival rate and developmental progression when cultured under similar conditions. We show that these mouse embryos, when cultured in a defined medium in an atmosphere of 95% O2 / 5% CO2 in a rolling bottle culture apparatus at 37 &#176;&#8203;C for 16-40 hr, exhibit morphological growth and development comparable to the embryos developing in utero. We believe this method will be useful for investigators needing to utilize whole embryo culture to study signaling interactions important in embryonic organogenesis.

Serum utilized in embryo cultures contains unknown components that can affect the outcome of experiments especially in studies involving signaling interactions. Here we utilized a serum-free oxygenated culture system and show that mid-gestation mouse embryos cultured for 16-40 hr&#160;exhibit morphological development comparable to embryos developing in utero.

Rato Desenvolvimento Embrionário em todo um sistema de cultura de embriões sem soro

Mid-gestation stage mouse embryos were cultured utilizing a serum-free culture medium prepared from commercially available stem cell media supplements in ...

Ex vivo Culture of Mouse Embryonic Skin and Live-imaging of Melanoblast Migration

Melanoblasts are the neural crest derived precursors of melanocytes; the cells responsible for producing the pigment in skin and hair. Melanoblasts migrate through the epidermis of the embryo where they subsequently colonize the developing hair follicles1,2. Neural crest cell migration is extensively studied in vitro but in vivo methods are still not well developed, especially in mammalian systems. One alternative is to use ex vivo organotypic culture3-6. Culture of mouse embryonic skin requires the maintenance of an air-liquid interface (ALI) across the surface of the tissue3,6. High resolution live-imaging of mouse embryonic skin has been hampered by the lack of a good method that not only maintains this ALI but also allows the culture to be inverted and therefore compatible with short working distance objective lenses and most confocal microscopes. This article describes recent improvements to a method that uses a gas permeable membrane to overcome these problems and allow high-resolution confocal imaging of embryonic skin in ex vivo culture6. By using a melanoblast specific Cre-recombinase expressing mouse line combined with the R26YFPR reporter line we are able to fluorescently label the melanoblast population within these skin cultures. The technique allows live-imaging of melanoblasts and observation of their behavior and interactions with the tissue in which they develop. Representative results are included to demonstrate the capability to live-image 6&#160;cultures in parallel.

Ex vivo Culture of Mouse Embryonic Skin and Live-imaging of Melanoblast Migration

We describe the dissection and ex vivo culture of mouse embryonic skin. The culture system maintains an air-liquid interface across the tissue surface and allows imaging on an inverted microscope. Melanoblasts, a component of the developing skin, are fluorescently labeled allowing their behavior to be observed using confocal microscopy.

Ex vivo Cultura do Rato Embryonic pele e Live-imaging de Migração melanoblasto

Melanoblasts are the neural crest derived precursors of melanocytes; the cells responsible for producing the pigment in skin and hair. Melanoblasts ...

Protein Isolation from the Developing Embryonic Mouse Heart Valve Region

Western blot analysis is a commonly employed technique for detecting and quantifying protein levels. However, for small tissue samples, this analysis method may not be sufficiently sensitive to detect a protein of interest. To overcome these difficulties, we examined protocols for obtaining protein from adult human cardiac valves and modified these protocols for the developing early embryonic mouse counterparts. In brief, the mouse embryonic aortic valve regions, including the aortic valve and surrounding aortic wall, are collected in the minimal possible volume of a Tris-based lysis buffer with protease inhibitors. If required based on the breeding strategy, embryos are genotyped prior to pooling four embryonic aortic valve regions for homogenization. After homogenization, an SDS-based sample buffer is used to denature the sample for running on an SDS-PAGE gel and subsequent western blot analysis. Although the protein concentration remains too low to quantify using spectrophotometric protein quantification assays and have sample remaining for subsequent analyses, this technique can be used to successfully detect and semi-quantify phosphorylated proteins via western blot from pooled samples of four embryonic day 13.5 mouse aortic valve regions, each of which yields approximately 1 &#956;g of protein. This technique will be of benefit for studying cell signaling pathway activation and protein expression levels during early embryonic mouse valve development.

The analysis of protein expression in young embryonic mouse valves has been hampered by the limited tissue available. This manuscript provides a protocol for preparing protein from developing embryonic mouse valve regions for western blot analysis.

Isolamento de proteínas a partir da Embryonic Rato Coração Região Válvula Desenvolvimento

Western blot analysis is a commonly employed technique for detecting and quantifying protein levels. However, for small tissue samples, this analysis ...

The c-FOS Protein Immunohistological Detection: A Useful Tool As a Marker of Central Pathways Involved in Specific Physiological Responses In Vivo and Ex Vivo

Many studies seek to identify and map the brain regions involved in specific physiological regulations. The proto-oncogene c-fos, an immediate early gene, is expressed in neurons in response to various stimuli. The protein product can be readily detected with immunohistochemical techniques leading to the use of c-FOS detection to map groups of neurons that display changes in their activity. In this article, we focused on the identification of brainstem neuronal populations involved in the ventilatory adaptation to hypoxia or hypercapnia. Two approaches were described to identify involved neuronal populations in vivo in animals and ex vivo in deafferented brainstem preparations. In vivo, animals were exposed to hypercapnic or hypoxic gas mixtures. Ex vivo, deafferented preparations were superfused with hypoxic or hypercapnic artificial cerebrospinal fluid. In both cases, either control in vivo animals or ex vivo preparations were maintained under normoxic and normocapnic conditions. The comparison of these two approaches allows the determination of the origin of the neuronal activation i.e., peripheral and/or central. In vivo and ex vivo, brainstems were collected, fixed, and sliced into sections. Once sections were prepared, immunohistochemical detection of the c-FOS protein was made in order to identify the brainstem groups of cells activated by hypoxic or hypercapnic stimulations. Labeled cells were counted in brainstem respiratory structures. In comparison to the control condition, hypoxia or hypercapnia increased the number of c-FOS labeled cells in several specific brainstem sites that are thus constitutive of the neuronal pathways involved in the adaptation of the central respiratory drive.

The c-FOS Protein Immunohistological Detection: A Useful Tool As a Marker of Central Pathways Involved in Specific Physiological Responses In Vivo and Ex Vivo

Here, we present a protocol based on c-FOS protein immunohistological detection, a classical technique used for the identification of neuronal populations involved in specific physiological responses in vivo and ex vivo.

A proteína c-Fos Detecção imuno: Uma ferramenta útil como um marcador de vias centrais envolvidos em respostas fisiológicas específicas<em&gt; In Vivo</em&gt; e<em&gt; Ex Vivo</em

Many studies seek to identify and map the brain regions involved in specific physiological regulations. The proto-oncogene c-fos, an immediate early gene, ...