We would like to thank Andrea Portbury and Davin Townley-Tilson for critical reading of the manuscript and the NIH (grant # R01HL061656) for funding support.

NOTA: Todos los experimentos fueron aprobados por el Comité de Cuidado y Uso de Animales Institucional de la Universidad de Carolina del Norte en Chapel Hill. 1. Impuestos Especiales de la válvula aórtica <ol><li> Usando una técnica de eutanasia aprobadas para la etapa embrionaria de interés, la eutanasia a un ratón embarazada con cachorros en el día embrionario deseado (E) del desarrollo. </li><li> Utilice 70% de etanol para esterilizar el abdomen de la hembra embarazada. Levante la piel y los músculos de la parte inferior del abdomen hacia arriba y lejos de los órganos internos, y disecar la cavidad abdominal inferior Open femenino para permitir el acceso a la trompa uterina. </li><li> Para recuperar el cuerno uterino, mantenga el cuello del útero con una pinza y caudal cuidadosamente cortado al fórceps. Levante el cuerno uterino, cortar cualquier tejido conectivo que mantiene la bocina en su lugar, y completar la eliminación mediante la reducción de la unión de la trompa uterina con el oviducto. </li><li> Coloque el cuerno uterino diseccionado en una placa de Petri que contiene cold 0,1 M de tampón Tris (pH 7,6) y enjuague según sea necesario. A continuación, cortar el cuerno uterino en sentido longitudinal para exponer los sacos embrionarios abierta. </li><li> Para exponer el embrión, cortar y abrir un saco embrionario en la unión de la placenta y el embrión y cortar los vasos umbilicales para liberar el embrión. Coloque el embrión diseccionado en un segundo plato de Petri con frío tampón Tris 0,1 M. Devuelva la primera placa de Petri con los restantes embriones no seccionada a hielo hasta que esté listo para el próximo embrión. </li><li> Para mejorar el acceso de la pared torácica en el embrión, decapitar al embrión. Si genotipado es necesario, retire y guarde un pedazo de tejido extra en un tubo Eppendorf se colocó en hielo. </li><li> Coloque el embrión en su parte posterior, y cortar la pared torácica verticalmente a lo largo del lado de la caja torácica, cerca de una extremidad anterior, y horizontalmente por encima del diafragma para visualizar el corazón. Luego, abrir la pared torácica para exponer el corazón. </li><li> Con unas pinzas para mantener en alto a lo largo de los grandes vasos, levantar el corazón con unas pinzas y cortar los vasos debajo. Eln, corte por encima de la pinza para liberar el corazón. Si los vasos pulmonares permanecen sin cortar, los pulmones se pueden eliminar con el corazón y deben ser removidos antes de continuar. </li><li> Corte y retire la arteria pulmonar por encima del nivel de la válvula; en las etapas embrionarias descritos en este documento, la arteria pulmonar es ligeramente opaca, que ayuda en su discriminación de la región de la válvula. Corte justo debajo de la válvula pulmonar, evitando el miocardio ventricular trabeculado y recoger como se describe en el paso 1.10 si esta región es también de interés. Aquí y en la siguiente etapa, usar la acción capilar para extraer el exceso de tampón Tris lejos de la región de interés antes de la recogida en tampón de lisis. </li><li> Retire cuidadosamente la aorta distal a la válvula aórtica, justo por encima del nivel de la válvula; como la arteria pulmonar, la aorta se mantiene ligeramente opaca en estas etapas embrionarias, ayudar en su eliminación. Corte justo debajo de la válvula aórtica, evitando de nuevo el miocardio ventricular trabeculado, y transferir elválvula usando fórceps a un tubo Eppendorf con tampón de lisis 2 l (descrito en la Tabla de Materiales) que contiene inhibidores de la proteasa y fosfatasa en hielo. </li><li> Repetir los pasos 1.6 a 1.10 hasta que las válvulas han sido extirpados de todos los embriones, la recogida de cada válvula en un tubo Eppendorf separado. Si todos los embriones tienen el mismo genotipo, todas las válvulas pueden ser recogidos en un solo tubo Eppendorf. </li><li> Si el genotipado se va a realizar para determinar qué válvulas para agrupar juntos, colocar inmediatamente las muestras en tampón de lisis a -80 ° C hasta su uso posterior. Las muestras pueden luego ser agrupados después de genotipado (etapa 2.1.1). </li></ol> Extracción 2. Proteína <ol><li> Descongele tejidos recogidos en el hielo y se centrifuga a 13.100 xg durante 1 min para recoger los tejidos en tampón de lisis en la parte inferior del tubo. <ol><li> Si se genotipo embriones, utilizar una pipeta para recoger suavemente y tampón piscina lisis que contiene las regiones de la válvula a partir de embriones con genotipos similares. Para asegurar una fuerte by, la puesta en común 3-4 regiones de la válvula a partir de embriones E13.5 se recomienda por muestra. </li><li> Si todos los embriones eran de la misma genotipo y todas las regiones de la válvula se recogieron juntos en el paso 1.10, lisar toda la muestra, como se describe en el Paso 2.2. </li></ol></li><li> Compruebe el volumen de la muestra agrupada resultante y añadir tampón de lisis hasta un volumen total de 40 l; entonces, desarticular y homogeneizar muestras usando 5 mm bolas de acero inoxidable en tubos Eppendorf. Operar el Lyser durante 2-4 min a 50 Hz, según las instrucciones del fabricante. Centrifugar los tubos brevemente, (~ 13.100 xg durante 1 min), y transferencia de muestras a tubos nuevos, dejando atrás los restos insolubles. </li><li> Preparar y muestras separadas para SDS-PAGE y transferencia de Western blot posterior, siguiendo un protocolo como Eslami et al 9. Secante para una proteína de control de carga es esencial para la cuantificación de proteínas. </li></ol>

<ol>
	<li>Wirrig, E. E., Hinton, R. B., Yutzey, K. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+expression+of+cartilage+and+bone-related+proteins+in+pediatric+and+adult+diseased+aortic+valves.">Differential expression of cartilage and bone-related proteins in pediatric and adult diseased aortic valves.</a> J Mol Cell Cardiol. 50, 561-569 (2011).</li><li>Chakraborty, 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=Twist1+promotes+heart+valve+cell+proliferation+and+extracellular+matrix+gene+expression+during+development+in+vivo+and+is+expressed+in+human+diseased+aortic+valves.">Twist1 promotes heart valve cell proliferation and extracellular matrix gene expression during development in vivo and is expressed in human diseased aortic valves.</a> Dev Biol. 347, 167-179 (2010).</li><li>Lee, M. P., Yutzey, K. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Twist1+directly+regulates+genes+that+promote+cell+proliferation+and+migration+in+developing+heart+valves.">Twist1 directly regulates genes that promote cell proliferation and migration in developing heart valves.</a> PLoS One. 6 (e29758), (2011).</li><li>Peacock, J. D., Huk, D. J., Ediriweera, H. N., Lincoln, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sox9+transcriptionally+represses+Spp1+to+prevent+matrix+mineralization+in+maturing+heart+valves+and+chondrocytes.">Sox9 transcriptionally represses Spp1 to prevent matrix mineralization in maturing heart valves and chondrocytes.</a> PLoS One. 6 (e26769), (2011).</li><li>Chakraborty, S., Cheek, J., Sakthivel, B., Aronow, B. J., Yutzey, K. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Shared+gene+expression+profiles+in+developing+heart+valves+and+osteoblast+progenitor+cells.">Shared gene expression profiles in developing heart valves and osteoblast progenitor cells.</a> Physiol Genomics. 35, 75-85 (2008).</li><li>Vogel, C., Marcotte, E. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Insights+into+the+regulation+of+protein+abundance+from+proteomic+and+transcriptomic+analyses.">Insights into the regulation of protein abundance from proteomic and transcriptomic analyses.</a> Nat Rev Genet. 13, 227-232 (2012).</li><li>Meng, X., 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=Expression+of+functional+Toll-like+receptors+2+and+4+in+human+aortic+valve+interstitial+cells:+potential+roles+in+aortic+valve+inflammation+and+stenosis.">Expression of functional Toll-like receptors 2 and 4 in human aortic valve interstitial cells: potential roles in aortic valve inflammation and stenosis.</a> Am J Physiol Cell Physiol. 294, 29-35 (2008).</li><li>Dyer, L. A., Wu, Y., Moser, M., Patterson, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=BMPER-induced+BMP+signaling+promotes+coronary+artery+remodeling.">BMPER-induced BMP signaling promotes coronary artery remodeling.</a> Developmental Biology. 386, 385-394 (2014).</li><li>Eslami, A., Lujan, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Western+blotting:+sample+preparation+to+detection.">Western blotting: sample preparation to detection.</a> J Vis Exp. (44), (2010).</li><li>Garside, V. C., Chang, A. C., Karsan, A., Hoodless, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Co-ordinating+Notch,+BMP,+and+TGF-beta+signaling+during+heart+valve+development.">Co-ordinating Notch, BMP, and TGF-beta signaling during heart valve development.</a> Cell Mol Life Sci. 70, 2899-2917 (2013).</li><li>Jiang, X., Rowitch, D. H., Soriano, P., McMahon, A. P., Sucov, H. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fate+of+the+mammalian+cardiac+neural.">Fate of the mammalian cardiac neural.</a> Development. 127, 1607-1616 (2000).</li><li>Scherptong, R. W., 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=Morphogenesis+of+outflow+tract+rotation+during+cardiac+development:+the+pulmonary+push+concept.">Morphogenesis of outflow tract rotation during cardiac development: the pulmonary push concept.</a> Dev Dyn. 241, 1413-1422 (2012).</li><li>Mohler, E. R., Adam 3rd, L. P., McClelland, P., Graham, L., Hathaway, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+osteopontin+in+calcified+human+aortic+valves.">Detection of osteopontin in calcified human aortic valves.</a> Arterioscler Thromb Vasc Biol. 17, 547-552 (1997).</li></ol>

The authors have nothing to disclose.

La capacidad de cuantificar los niveles de proteína a principios de embriones de ratón y Chick regiones válvula cardíaca proporciona una herramienta adicional para la comprensión de los eventos de señalización celular críticas para el desarrollo de la válvula. Nuestro protocolo descrito en este documento no difiere en gran medida de los procedimientos de aislamiento de proteínas convencionales. Sin embargo, mediante la modificación de algunas medidas clave, que hemos obtenido con éxito proteínas fosforilada...

Ser capaz de identificar y cuantificar los niveles de expresión de proteínas es una técnica estándar para animal- y los experimentos basados ​​en células. Sin embargo, a pesar de un interés de larga data en el desarrollo de la válvula cardíaca embrionaria temprana, la evaluación de la expresión de proteínas en este tejido específico durante el desarrollo se limita actualmente a la inmunohistoquímica en tanto el pollo y 1,2 ratón. Parte de la dificultad de cuantificar la expresión de proteínas en las válvulas de desarrollo de la mayoría de organismos modelo (por ejemplo, de pollo y de ratón) es el pequeño tamaño de las válvulas, lo que limita la cantidad de proteína que se puede obtener. Por lo tanto, para los análisis cuantitativos, los investigadores normalmente se basan en la extracción de ARN y amplificación por PCR cuantitativa posterior o el análisis de microarrays 2-5. Sin embargo, los niveles de expresión de ARN y proteínas no son del todo correlativa 6, por lo que se centra en la expresión del ARN no pueden dar una explicación rigurosa de los numerosos cambios que se producen en cualquier señalización dadavía en varias ocasiones durante la evolución. Sobre la base de este límite en la metodología actualmente disponible, el objetivo de este procedimiento fue desarrollar un protocolo para la obtención fiable de cantidades suficientes de proteína a partir de las regiones de la válvula cardiaca de embriones de ratón en desarrollo para el análisis cuantitativo de los cambios que se producen en diversas vías de señalización que son importantes en la maduración de este tejido. Válvulas embrionarias son ya comúnmente disecados de los ratones para el aislamiento de ARN y análisis de expresión génica posterior 2-5. Sin embargo, estos estudios se han limitado a la utilización de la expresión génica como una lectura de salida de activación de la vía de señalización, que no permite la detección de detectar proteínas modificaciones post-traduccionales que pueden afectar a la señalización aguas abajo. Utilizando las técnicas de aislamiento de ARN como punto de partida, comenzamos con la disección de las regiones de interés. Debido a que nuestro interés se detecta proteínas fosforiladas que eran indicativos de pat señalizaciónhway actividad durante un período específico de desarrollo de la válvula aórtica (E13.5-14.5), que realiza todas las disecciones en tampón Tris-fosfato libre y se recogió las válvulas en un tampón de lisis a base de Tris con inhibidores de fosfatasa y proteasa. En nuestro caso específico, sólo se recogieron las regiones de la válvula aórtica, pero la región de la válvula pulmonar podrían obtenerse fácilmente al mismo tiempo. Las regiones de la válvula fueron entonces homogeneizada y combinado con un tampón de muestra que se utiliza actualmente para estudiar la expresión de proteínas en las válvulas cardiacas adultas 7. Mediante el uso de pequeños volúmenes de muestra (por ejemplo, 2 l) y puesta en común de las regiones de la válvula a partir de embriones con el mismo genotipo, hemos sido capaces de detectar las proteínas fosforiladas y no fosforilada en el día embrionario 13.5 8. Debido a que las regiones de válvula pueden ser congelados y almacenados en tampón de lisis, los embriones pueden ser genotipados si es necesario antes de la puesta en común. Esta técnica amplía el conjunto de herramientas que están disponibles para evaluar signalin celularg vías durante el desarrollo y ofrece un cumplido cuantitativa de inmunohistoquímica, específicamente para las válvulas cardíacas en desarrollo. Esta técnica debe ser de beneficio no sólo para los cardiólogos de desarrollo, sino también a todos los biólogos del desarrollo que trabajan con embriones en fase inicial están interesados ​​en regiones que contienen tejido limitado.

<table border="0" cellpadding="0" cellspacing="0" width="972">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Name of Reagent/ Equipment</td>
			<td style="width:125px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:512px;">Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Timed-pregnant mouse</td>
			<td style="width:125px;"></td>
			<td style="width:119px;"></td>
			<td>To be dissected at the embryonic stage of interest</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Stereoscopic microscope</td>
			<td style="width:125px;">Nikon</td>
			<td style="width:119px;">SMZ645</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">0.1 M Tris, pH 7.6</td>
			<td style="width:125px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Microscissors</td>
			<td style="width:125px;">Fine Science Tools</td>
			<td style="width:119px;">15003-08</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Fine forceps, #5</td>
			<td style="width:125px;">Fine Science Tools</td>
			<td style="width:119px;">11251-30</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Dissecting needle holders</td>
			<td style="width:125px;">Ted Pella Inc.</td>
			<td style="width:119px;">13560</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Dissecting needles</td>
			<td style="width:125px;">Ted Pella Inc.</td>
			<td style="width:119px;">13561-10</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Micropipette, 20 &#956;l, with tips</td>
			<td style="width:125px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Lysis buffer</td>
			<td style="width:125px;"></td>
			<td style="width:119px;"></td>
			<td>50 mM Tris-HCl, pH 7.5, 150 mM NaCl, 5 mM EDTA, 1% Triton</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">PhosSTOP</td>
			<td style="width:125px;">Roche</td>
			<td style="width:119px;">4906845001</td>
			<td>Add 1 tablet to 10 ml lysis buffer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">TissueLyser LT</td>
			<td style="width:125px;">Qiagen</td>
			<td style="width:119px;">85600</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Stainless steel beads</td>
			<td style="width:125px;">Qiagen</td>
			<td align="right">69989</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Microcentrifuge</td>
			<td style="width:125px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
	</tbody>
</table>

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.

Utilizando esta técnica de preparación, hemos sido capaces de detectar fosforilados Smad 1,5,8 (pSmad) en las regiones de la válvula aórtica individuales de E13.5 embriones. Como se muestra en la Figura 1A, la proteína aislada de incluso una sola región de la válvula es suficiente para detectar una banda pSmad débil. Intensidad de la señal aumenta proporcionalmente con el número de regiones de la válvula que se agruparon. Es importante destacar que la relación pSmad / β-actina se...

Watch this Scientific Journal Video about Protein Isolation from the Developing Embryonic Mouse Heart Valve Region at JoVE.com

Protein Isolation from the Developing Embryonic Mouse Heart Valve Region

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.

Proteína Aislamiento del desarrollo embrionario del corazón del ratón Válvula Región

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

protein-isolation-from-developing-embryonic-mouse-heart-valve

Research

JoVE Journal

Biology

9.3K vistas.  University of North Carolina at Chapel Hill. 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.

Video: Protein Isolation from the Developing Embryonic Mouse Heart Valve Region

Micro-dissection of Rat Brain for RNA or Protein Extraction from Specific Brain Region

Micro-dissection of rat brain into various regions is extremely important for the study of different neurodegenerative diseases. This video demonstrates micro-dissection of four major brain regions include olfactory bulb, frontal cortex, striatum and hippocampus in fresh rat brain tissue. Useful tips for quick removal of respective regions to avoid RNA and protein degradation of the tissue are given.

Micro-dissection of rat brain into various regions is extremely important for the study of different neurodegenerative diseases. This video demonstrates micro-dissection of four major brain regions include olfactory bulb, frontal cortex, striatum and hippocampus in fresh rat brain tissue. Useful tips for quick removal of respective regions to avoid RNA and protein degradation of the tissue are given.

Micro-disección de cerebro de rata para el ARN o la extracción de proteínas a partir de región específica del cerebro

Micro-dissection of rat brain into various regions is extremely important for the study of different neurodegenerative diseases. This video demonstrates ...

Investigación

Biología

Isolation and Derivation of Mouse Embryonic Germinal Cells

The ability of embryonic germinal cells (EG) to differentiate into primordial germinal cells (PGCs) and later into gametes during early developmental stages is a perfect model to address our hypothesis about cancer and infertility. This protocol shows how to isolate primordial germinal cells from developing gonads in 10.5-11.5 days post coitum (dpc) mouse embryos.  Developing gonadal ridges from mouse embryos (C57BL6J) were dissociated by mechanical disruption with collagenase, then plated in a mouse embryo fibroblast feeder layer (MEF-CF1) that was previously mitotically inactivated with mitomycin C in the presence of knockout media and supplemented with Leukemia Inhibitor Factor (LIF), basic Fibroblast Growth Factor (bFGF), and Stem Cell Factor (SCF).  Using these optimized methods for PCG identification, isolation, and establishment of culture conditions permits long term cultures of EG cells for more than 40 days.  The embryonic germinal cell lines showed embryonic phenotype and expression of common used markers of the pluripotent state.  Isolation and derivation of germinal cells in culture provide a tool to understand their development in vitro and offer the opportunity to monitor cumulative damage at genetic and epigenetic levels after exposure to oxidative stress.

The ability of embryonic germinal cells to differentiate into primordial germinal cells during early development stages is a perfect model to address our hypothesis about cancer and infertility. This protocol shows how to isolate primordial germinal cells from developing gonads in 10.5-11.5 days post coitum mouse embryos.

El aislamiento y la derivación de células embrionarias de ratón Germinal

The ability of embryonic germinal cells (EG) to differentiate into primordial germinal cells (PGCs) and later into gametes during early developmental ...

Isolation and Culture of Cells from the Nephrogenic Zone of the Embryonic Mouse Kidney

Embryonic development of the kidney has been extensively studied both as a model for epithelial-mesenchymal interaction in organogenesis and to gain understanding of the origins of congenital kidney disease. More recently, the possibility of steering na&iuml;ve embryonic stem cells toward nephrogenic fates has been explored in the emerging field of regenerative medicine. Genetic studies in the mouse have identified several pathways required for kidney development, and a global catalog of gene transcription in the organ has recently been generated <a href="http://www.gudmap.org/">http://www.gudmap.org/</a>, providing numerous candidate regulators of essential developmental functions. Organogenesis of the rodent kidney can be studied in organ culture, and many reports have used this approach to analyze outcomes of either applying candidate proteins or knocking down the expression of candidate genes using siRNA or morpholinos. However, the applicability of organ culture to the study of signaling that regulates stem/progenitor cell differentiation versus renewal in the developing kidney is limited as cultured organs contain a compact extracellular matrix limiting diffusion of macromolecules and virus particles. To study the cell signaling events that influence the stem/progenitor cell niche in the kidney we have developed a primary cell system that establishes the nephrogenic zone or progenitor cell niche of the developing kidney ex vivo in isolation from the epithelial inducer of differentiation. Using limited enzymatic digestion, nephrogenic zone cells can be selectively liberated from developing kidneys at E17.5. Following filtration, these cells can be cultured as an irregular monolayer using optimized conditions. Marker gene analysis demonstrates that these cultures contain a distribution of cell types characteristic of the nephrogenic zone in vivo, and that they maintain appropriate marker gene expression during the culture period. These cells are highly accessible to small molecule and recombinant protein treatment, and importantly also to viral transduction, which greatly facilitates the study of candidate stem/progenitor cell regulator effects. Basic cell biological parameters such as proliferation and cell death as well as changes in expression of molecular markers characteristic of nephron stem/progenitor cells in vivo can be successfully used as experimental outcomes. Ongoing work in our laboratory using this novel primary cell technique aims to uncover basic mechanisms governing the regulation of self-renewal versus differentiation in nephron stem/progenitor cells.

In this report we describe a method for the isolation and culture of the progenitor cell niche from the embryonic mouse kidney that can be used to study signaling pathways regulating stem/progenitor cells of the developing kidney. These cultured cells are highly accessible to small molecule and recombinant protein treatment, and importantly also to viral transduction, which allows efficient manipulation of candidate pathways.

Aislamiento y cultivo de células de la zona nefrogénica del riñón de embriones de ratón

Embryonic development of the kidney has been extensively studied both as a model for epithelial-mesenchymal interaction in organogenesis and  to gain ...

Immunostaining of Dissected Zebrafish Embryonic Heart

Zebrafish embryo becomes a popular in vivo vertebrate model for studying cardiac development and human heart diseases due to its advantageous embryology and genetics 1,2. About 100-200 embryos are readily available every week from a single pair of adult fish. The transparent embryos that develop ex utero make them ideal for assessing cardiac defects 3. The expression of any gene can be manipulated via morpholino technology or RNA injection 4. Moreover, forward genetic screens have already generated a list of mutants that affect different perspectives of cardiogenesis 5. 
Whole mount immunostaining is an important technique in this animal model to reveal the expression pattern of the targeted protein to a particular tissue 6. However, high resolution images that can reveal cellular or subcellular structures have been difficult, mainly due to the physical location of the heart and the poor penetration of the antibodies. 
 Here, we present a method to address these bottlenecks by dissecting heart first and then conducting the staining process on the surface of a microscope slide. To prevent the loss of small heart samples and to facilitate solution handling, we restricted the heart samples within a circle on the surface of the microscope slides drawn by an immEdge pen. After the staining, the fluorescence signals can be directly observed by a compound microscope. 
Our new method significantly improves the penetration for antibodies, since a heart from an embryonic fish only consists of few cell layers. High quality images from intact hearts can be obtained within a much reduced procession time for zebrafish embryos aged from day 2 to day 6. Our method can be potentially extended to stain other organs dissected from either zebrafish or other small animals.

A rapid way to conduct immunostaining of zebrafish embryonic heart is described. Compared to the whole mount immunostaining approach, this method dramatically increases the penetration of the antibodies, which allows obtaining high resolution images that reveal cellular/subcellular structures in the heart within a much reduced processing time.

Inmunotinción de Disección del corazón embrionario de pez cebra

Zebrafish embryo becomes a popular in vivo vertebrate model for studying cardiac development and human heart diseases due to its advantageous embryology ...

Generation of Mice Derived from Induced Pluripotent Stem Cells

The production of induced pluripotent stem cells (iPSCs) from somatic cells provides a means to create valuable tools for basic research and may also produce a source of patient-matched cells for regenerative therapies. iPSCs may be generated using multiple protocols and derived from multiple cell sources. Once generated, iPSCs are tested using a variety of assays including immunostaining for pluripotency markers, generation of three germ layers in embryoid bodies and teratomas, comparisons of gene expression with embryonic stem cells (ESCs) and production of chimeric mice with or without germline contribution2. Importantly, iPSC lines that pass these tests still vary in their capacity to produce different differentiated cell types2. This has made it difficult to establish which iPSC derivation protocols, donor cell sources or selection methods are most useful for different applications.
The most stringent test of whether a stem cell line has sufficient developmental potential to generate all tissues required for survival of an organism (termed full pluripotency) is tetraploid embryo complementation (TEC)3-5. Technically, TEC involves electrofusion of two-cell embryos to generate tetraploid (4n) one-cell embryos that can be cultured in vitro to the blastocyst stage6. Diploid (2n) pluripotent stem cells (e.g. ESCs or iPSCs) are then injected into the blastocoel cavity of the tetraploid blastocyst and transferred to a recipient female for gestation (see Figure 1). The tetraploid component of the complemented embryo contributes almost exclusively to the extraembryonic tissues (placenta, yolk sac), whereas the diploid cells constitute the embryo proper, resulting in a fetus derived entirely from the injected stem cell line.
Recently, we reported the derivation of iPSC lines that reproducibly generate adult mice via TEC1. These iPSC lines give rise to viable pups with efficiencies of 5-13%, which is comparable to ESCs3,4,7 and higher than that reported for most other iPSC lines8-12. These reports show that direct reprogramming can produce fully pluripotent iPSCs that match ESCs in their developmental potential and efficiency of generating pups in TEC tests. At present, it is not clear what distinguishes between fully pluripotent iPSCs and less potent lines13-15. Nor is it clear which reprogramming methods will produce these lines with the highest efficiency. Here we describe one method that produces fully pluripotent iPSCs and "all- iPSC" mice, which may be helpful for investigators wishing to compare the pluripotency of iPSC lines or establish the equivalence of different reprogramming methods.

Generating induced pluripotent stem cell (iPSC) lines produces lines of differing developmental potential even when they pass standard tests for pluripotency. Here we describe a protocol to produce mice derived entirely from iPSCs, which defines the iPSC lines as possessing full pluripotency1.

Generación de ratones derivados de células madre pluripotentes inducidas

The production of induced pluripotent stem cells (iPSCs) from somatic cells provides a means to create valuable tools for basic research and may also ...

Isolating Primary Melanocyte-like Cells from the Mouse Heart

We identified a novel population of melanocyte-like cells (also known as cardiac melanocytes) in the hearts of mice and humans that contribute to atrial arrhythmia triggers in mice. To investigate the electrical and biological properties of cardiac melanocytes we developed a procedure to isolate them from mouse hearts that we derived from those designed to isolate neonatal murine cardiomyocytes. In order to obtain healthier cardiac melanocytes suitable for more extensive patch clamp or biochemical studies, we developed a refined procedure for isolating and plating cardiac melanocytes based on those originally designed to isolate cutaneous melanocytes. The refined procedure is demonstrated in this review and produces larger numbers of healthy melanocyte-like cells that can be plated as a pure population or with cardiomyocytes.

In this protocol, we identified a novel population of melanocyte-like cells (also known as cardiac melanocytes) in the hearts of mice and humans that contribute to atrial arrhythmia triggers in mice.&#160;

Aislar las células melanocitos como primarios del corazón alfombrillas

We identified a novel population of melanocyte-like cells (also known as cardiac melanocytes) in the hearts of mice and humans that contribute to atrial ...

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; Método de la cultura para el corazón de embriones de ratón

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

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.

Aislamiento de células endoteliales embrionarias ventriculares

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

Cell Labeling and Injection in Developing Embryonic Mouse Hearts

Testing the fate of embryonic or pluripotent stem cell-derivatives in in vitro protocols has led to controversial outcomes that do not necessarily reflect their in vivo potential. Preferably, these cells should be placed in a proper embryonic environment in order to acquire their definite phenotype. Furthermore, cell lineage tracing studies in the mouse after labeling cells with dyes or retroviral vectors has remained mostly limited to early stage mouse embryos with still poorly developed organs. To overcome these limitations, we designed standard and ultrasound-mediated microinjection protocols to inject various agents in targeted regions of the heart in mouse embryos at E9.5 and later stages of development. &#160;Embryonic explant or embryos are then cultured or left to further develop in utero. These agents include fluorescent dyes, virus, shRNAs, or stem cell-derived progenitor cells. Our approaches allow for preservation of the function of the organ while monitoring migration and fate of labeled and/or injected cells. These technologies can be extended to other organs and will be very helpful to address key biological questions in biology of development.

We describe a series of methods to inject dyes, DNA vectors, virus, and cells in order to monitor both cell fate and phenotype of endogenous and grafted cells derived from embryonic or pluripotent cells within mouse embryos at embryonic day (E)9.5 and later stages of development.

Etiquetado de la célula y de inyección en Desarrollo de embriones de ratón Corazones

Testing the fate of embryonic or pluripotent stem cell-derivatives in in vitro protocols has led to controversial outcomes that do not necessarily reflect ...

Isolation of Murine Valve Endothelial Cells

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

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

Aislamiento de las células murinas de la válvula endoteliales

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