Agradecemos Jianhua Ling, Raymond MacDonald, Galvin Swift, Michelle Griffin, Paul Grippo y Satyanarayana Rachagani por sus útiles comentarios, sugerencias y compartir sus protocolos. Este trabajo fue apoyado por U01CA111294 subvención y un premio de desarrollo de la idea del Programa de Investigación Intramural la Universidad Estatal de Ohio.

1. Preparación Las siguientes prácticas se adhieren a las políticas establecidas por el Cuidado de Animales y el empleo Comisión de la Institución (IACUC). <ol><li> Se recomienda aislar a no más de 6 páncreas de ratón en un día determinado. Tener todos los instrumentos quirúrgicos limpios y esterilizados en autoclave, un juego por animal. </li><li> Marque todos los tubos de microcentrífuga. Cuatro tubos de 2 ml por animal. </li><li> Coloque 8 ml de reactivo de lisis en 50 ml tubos de centrífuga en hielo. Nota: Mientras que el kit de purificación viene con un reactivo de fenol de tiocianato de guanidina que es adecuado para el aislamiento páncreas, reactivo de lisis se utiliza debido a los grandes volúmenes que son necesarios por el aislamiento. </li><li> Vierta aproximadamente 10 ml de las siguientes soluciones en 15 ml tubos de centrífuga para la limpieza de las cuchillas del homogeneizador. Etanol, 70% (2 tubos), agua de calidad HPLC (1 tubo) y agua de grado HPLC que contiene aproximadamente 200 l de RNasa visitante o inactivador ribonucleasa equivalente. </li></ol&gt; 2. Cirugía, Dissection Páncreas y homogeneización <ol><li> Coloque 1.2 ml de isoflurano en un frasco que contiene gasa de algodón o toallas de papel. Los ratones se colocan en una plataforma que les impide alcanzar la fuente de la isoflurano. Añadir isoflurano fresca en la jarra antes de anestesiar cada ratón. </li><li> Con cuidado, coloque el ratón en el frasco que contiene el isoflurano. Tapar el frasco y controlar los efectos de la anestesia, girando suavemente el frasco de un lado a otro. El animal se anestesia una vez que está en incapaz de soportar en su &#39;propia. </li><li> Para la confirmación de la anestesia, retire al animal del frasco y aplicar una pizca dedo del pie firme. Si el ratón no reacciona a la pizca dedo del pie, siga en el paso 2.5. </li><li> Si el ratón reacciona a la pizca dedo del pie, a continuación, repita los pasos 2.2 hasta 2.3. </li><li> Colocar el animal anestesiado en la mesa de trabajo en la posición prona. Dislocar el cuello uterino de ratón por fuerza colocando la mano izquierda sobre el cuello uterino de ratón. Nosotrosción de la mano derecha agarre la cola del ratón y tire hacia arriba de forma rápida a un ángulo aproximado de 45 ° para dislocar el cuello del útero. </li><li> Fije la carcasa a una superficie (una pieza nivel de espuma de poliestireno cubierta con toallas de papel) por la perforación de cada uno de cuatro patas de los animales en la superficie plana usando calibre 25 agujas hipodérmicas. </li><li> El uso de instrumentos quirúrgicos estériles, cortar la sección media del ratón abierta y rápidamente extirpar el páncreas del ratón. Utilice las pinzas para sujetar el páncreas y cortarlo del bazo y el intestino delgado utilizando tijeras de primavera. Tenga cuidado de no estirar el páncreas durante la eliminación del uso del ratón. La alteración del tejido podría liberar ribonucleasa. Nota: El tiempo que se necesita para extirpar el páncreas del ratón es crítica. Un experto en la materia debe ser capaz de diseccionar el páncreas en aproximadamente 1 min o menos. </li><li> Coloque todo el páncreas en un tubo de 50 ml que contiene 8 ml de hielo reactivo de lisis frío. Tapar el tubo y agitar brevemente para sumergir el tiN ú mero en el reactivo y proceder a la siguiente etapa sin demora. La proporción de reactivo de lisis a los tejidos es crítico. Ver la sección de resultados para una comparación de la integridad del ARN aislado usando diferentes volúmenes de reactivo de lisis. </li><li> Homogeneizar durante 5 seg. Es importante presionar las cuchillas homogeneizador para la parte inferior del tubo de centrífuga para permitir que el tejido sea arrastrado hacia las cuchillas para la homogeneización eficiente. </li></ol> 3. Eliminación de tejido no digerido Nota: Después de la homogeneización, pequeños trozos de tejido se mantendrán en el reactivo de lisis. Es más importante para lisar rápidamente el tejido dejando algo de tejido sin digerir en lugar de sobre la homogeneización y la degradación riesgo de ARN. <ol><li> Transferencia de 2 ml de reactivo de lisis que contiene el páncreas lisadas a un tubo de microcentrífuga de 2 ml. Recoge dos tubos de microcentrífuga de homogeneizado por el aislamiento. Deseche el material homogeneizado restante o almacenar a -80 ° C para futuros estudios. </li><li> Centavorifuge a 4 º C, 12000 × g durante 5 min para sedimentar el tejido no digerido. Este es un paso crítico como el arrastre de tejido no digerido en soluciones posteriores de ARN probablemente contamine la muestra con ribonucleasa (paso 5,13). </li><li> Transferencia de 1 ml del sobrenadante en un tubo de microcentrífuga de 2 ml. Proceda con el aislamiento inmediato y guarde el tubo de réplica a -80 ° C para su uso futuro. Coloque todos los tubos que contienen homogeneizado en hielo húmedo mientras se procede al siguiente paso. </li><li> Deseche el reactivo de lisis restante en un recipiente para desechos químicos apropiados. </li></ol> 4. Limpieza de las cuchillas Homogeneizador <ol><li> Antes de proceder a la siguiente aislamiento, limpiar las cuchillas homogeneizador colocándolos en 10 ml de etanol al 70%. Active el homogeneizador por alrededor de 20 segundos para quitar cualquier pedazo de tejido que pueden estar atrapados en las cuchillas. </li><li> Utilice una punta de pipeta de 200 l para eliminar las piezas que permanecen en las cuchillas homogeneizador. </li&gt; <li> Repita el paso 4.1 en el agua, en general inactivador Rnase y etanol al 70%. Secar el eje homogeneizador con una toallita limpia Kim. </li><li> Repita el paso 2.1 para el aislamiento del páncreas de los animales restantes, manteniendo ARN aislado de cada animal por separado en lugar de puesta en común de la ARN. </li></ol> 5. Aislamiento de ARN La siguiente sección es idéntica a el protocolo del kit de purificación. La ventaja de el kit de purificación es que va a aislar el ARN total, incluyendo pequeños RNAs. <ol><li> Si se utiliza la solución homogeneizado congelado, descongelar en hielo húmedo y dejar reposar a temperatura ambiente durante 5 min. </li><li> Añadir 200 l de cloroformo, tapar el tubo y agitar enérgicamente a mano durante 15 segundos. Deje reposar el tubo a temperatura ambiente durante 2-3 min. </li><li> Centrifugar durante 15 minutos a 12.000 xg, 4 º C </li><li> Transferir la capa acuosa superior a un tubo de microcentrífuga. Añadir 1,5 volúmenes de isopropanol y mezclar bien con la pipeta hacia arriba y abajo varias veces. </li><li> Traslado hasta el 700 l de la muestra en una columna de centrifugación que se coloca en un tubo de recogida de 2 ml. Cierre la tapa y centrifugar a 8000 xg durante 15 segundos a temperatura ambiente. </li><li> Deseche el flujo directo. </li><li> Repetir los pasos 5.5 a 5.6, utilizando el resto de la muestra. </li><li> Añadir 700 l Buffer TAR a la columna de centrifugación. Centrifugar durante 15 segundos a 8000 x g. Deseche el flujo directo. </li><li> Pipetear 500 l de tampón RPE en la columna de centrifugación. Centrifugar durante 15 segundos a 8.000 x g para lavar la columna. Deseche el flujo directo. </li><li> Añadir 500 l de tampón RPE a la columna de centrifugación. Centrifugar durante 2 min a 8000 xg para secar la columna. </li><li> Transferir la columna de centrifugación a un tubo de microcentrífuga de 1,5 ml. Pipetear 80 l de agua libre de ribonucleasa directamente sobre la membrana de la columna de centrifugación. Centrifugar durante 1 min a 8000 xg para eluir el ARN. </li><li> Añadir 1 l inhibidor de RNasa a la solución de ARN. Almacenar a -80 ° C o proceder a 5.13. </li><li> Para validar la integridad del ARN, primero calcular la conce ARNntration y 260/280 escala utilizando un espectrofotómetro. </li><li> Diluir una porción de la solución de ARN a aproximadamente 500 ng / l con agua de grado de biología molecular. </li><li> Determinar el ARN integridad (es decir, RIN) utilizando el análisis de electroforesis capilar. Aproximadamente 5 l de solución de ARN es suficiente para el análisis. </li><li> Alícuota de la solución de ARN (véase la Figura 2) y se almacena a -80 ° C. </li></ol>

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	<li>Chen, C., Ridzon, D. A., Broomer, A. J., Zhou, Z., Lee, D. H., Nguyen, J. T., Barbisin, M., Xu, N. L., Mahuvakar, V. R., Andersen, M. R., 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=Real-time+quantification+of+microRNAs+by+stem-loop+RT-PCR.">Real-time quantification of microRNAs by stem-loop RT-PCR.</a> Nucleic Acids Res. 33, e179 (2005).</li><li>Chirgwin, J. M., Przybyla, A. E., MacDonald, R. J., Rutter, W. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+of+biologically+active+ribonucleic+acid+from+sources+enriched+in+ribonuclease.">Isolation of biologically active ribonucleic acid from sources enriched in ribonuclease.</a> Biochemistry. 18, 5294-5299 (1979).</li><li>Chomczynski, P., Sacchi, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-step+method+of+RNA+isolation+by+acid+guanidinium+thiocyanate-phenol-chloroform+extraction.">Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction.</a> Anal Biochem. 162, 156-159 (1987).</li><li>Griffin, M., Abu-El-Haija, M., Abu-El-Haija, M., Rokhlina, T., Uc, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simplified+and+versatile+method+for+isolation+of+high-quality+RNA+from+pancreas.">Simplified and versatile method for isolation of high-quality RNA from pancreas.</a> Biotechniques. 52, 332-334 (2012).</li><li>Iyer, V. R., Eisen, M. B., Ross, D. T., Schuler, G., Moore, T., Lee, J. C., Trent, J. M., Staudt, L. M., Hudson Jr, J., Boguski, M. 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=The+transcriptional+program+in+the+response+of+human+fibroblasts+to+serum.">The transcriptional program in the response of human fibroblasts to serum.</a> Science. 283, 83-87 (1999).</li><li>Lenstra, J. A., Beintema, J. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+amino+acid+sequence+of+mouse+pancreatic+ribonuclease.+Extremely+rapid+evolutionary+rates+of+the+myomorph+rodent+ribonucleases.">The amino acid sequence of mouse pancreatic ribonuclease. Extremely rapid evolutionary rates of the myomorph rodent ribonucleases.</a> European journal of biochemistry FEBS. 98, 399-408 (1979).</li><li>Mullin, A. E., Soukatcheva, G., Verchere, C. B., Chantler, J. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Application+of+in+situ+ductal+perfusion+to+facilitate+isolation+of+high-quality+RNA+from+mouse+pancreas.">Application of in situ ductal perfusion to facilitate isolation of high-quality RNA from mouse pancreas.</a> Biotechniques. 40, 617-621 (2006).</li><li>Rio, D. C., Ares, M., Hannon, G. J., Nilsen, T. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> RNA A Laboratory Manual. , (2011).</li><li>Streit, S., Michalski, C. W., Erkan, M., Kleeff, J., Friess, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Northern+blot+analysis+for+detection+and+quantification+of+RNA+in+pancreatic+cancer+cells+and+tissues.">Northern blot analysis for detection and quantification of RNA in pancreatic cancer cells and tissues.</a> Nat Protoc. 4, 37-43 (2009).</li><li>Zmuda, E. J., Powell, C. A., Hai, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+method+for+murine+islet+isolation+and+subcapsular+kidney+transplantation.">A method for murine islet isolation and subcapsular kidney transplantation.</a> Journal of Visualized Experiments JoVE. , (2011).</li></ol>

The authors have nothing to disclose.

Aislar ARN de tejidos que se ribonucleasa rico representa un gran reto para los experimentos de biología molecular. Varios reactivos y kits están disponibles en el mercado que se basan principalmente en el método de tiocianato de guanidina fenol de la extracción de RNA. Tiocianato de guanidina desnaturaliza la proteína y por lo tanto reduce la actividad de la ribonucleasa. Sin embargo, la magnitud de la ribonucleasa en el páncreas requiere modificaciones adicionales a los protocolos estándar de aislamiento de ARN...

Se requiere Aislamiento de ARN con una alta integridad para los experimentos de biología molecular de rutina, como el norte de borrones 9, QRT-PCR 1 o perfiles de expresión genética 5. La mayoría de los métodos contemporáneos de aislamiento de ARN se basan en modificaciones de los protocolos de tiocianato de guanidina 2, 3. Tiocianato de guanidina es un fuerte desnaturalizante de proteínas y se interrumpir efectivamente la actividad de la ribonucleasa bajo la mayoría de condiciones. El método popular de Chomczynski y Sacchi 3 combinó fenol a la solución de tiocianato de guanidina de lisis, lo que reduce el tiempo de aislamiento a aproximadamente 4 horas. Muchos reactivos de extracción de ARN comercialmente disponibles se basan en el método de Chomczynski y Sacchi 3. Ribonucleasa tejidos ricos como humano o de ratón páncreas presenta un desafío adicional para el aislamiento de ARN. Ratón páncreas puede contener hasta 75 mg de ribonucleasa 6 algunos de los cuales se dará a conocer During interrupción del tejido pancreático que resulta en la autolisis de los tejidos. Las modificaciones de los protocolos de tiocianato de guanidina se han utilizado con éxito para aislar ARN a partir de páncreas con alta integridad 2, 4, 7, 10. Infusión de ARN de estabilización reactivo en páncreas de ratón aislamiento facilitado de ARN con alta integridad 4, 7, 10, sin embargo infusión de soluciones en el páncreas requiere una gran habilidad, pueden requerir instrumentos especializados tales como un microscopio de disección y alterar la arquitectura del tejido durante el procedimiento puede resultar en la lisis celular. Perfusión tisular con el reactivo de estabilización de ARN podría interferir con otras aplicaciones como el aislamiento de proteínas y la tinción histológica. Además, esta técnica no es adecuada para el aislamiento de ARN a partir de páncreas humano. Otros protocolos requieren la preparación de soluciones específicas del investigador 2. Se presenta un protocolo para aislar ARN con una alta integridad de páncreas de ratón. Thprotocolo de correo utiliza elementos de los métodos publicados anteriormente y se basa en gran parte de los protocolos de reactivo de lisis estándar de fenol / guanidina basado en tiocianato. No requiere la preparación de soluciones especializados ni requiere la infusión de los reactivos en el páncreas. Los pasos críticos para el aislamiento de ARN éxito incluyen un fenol alta / a base de guanidina lisis reactivo proporción de tejidos, extracción de tejido no digerido antes de la separación de fases y la inclusión de un inhibidor de ribonucleasa a la solución de ARN resultante. El uso de estas y otras modificaciones, que típicamente aislar el ARN con Rin mayor que 7 para ser utilizado para el análisis de la expresión génica de rutina.

<table><tbody><tr><td>Power Gen 500&amp;nbsp;</td><td>Fisher Scientific</td><td>14-261-03&amp;nbsp;</td><td>Homogenizer</td></tr><tr><td>5424R</td><td>Eppendorf</td><td></td><td>Refrigerated microcentifuge</td></tr><tr><td>Trizol reagent</td><td>Invitrogen</td><td>15596018</td><td>Lysis reagent</td></tr><tr><td>Student Vannas spring scissors</td><td>Fisher</td><td>91500-09&amp;nbsp;</td><td>Use to cut pancreas from attached tissues</td></tr><tr><td>Surgical scissors, 6 inch</td><td>Fisher</td><td>08-951-20</td><td>Use to cut scin of mouse</td></tr><tr><td>Blunt end forceps</td><td>Fisher</td><td>1381239</td><td>Use to hold pancreas while dissecting</td></tr><tr><td>Isoflurane USP</td><td>Abbott Labs</td><td>4/8/5210</td><td>Anesthetic</td></tr><tr><td>Rnase out (40 U/&amp;micro;l)</td><td>Invitrogen</td><td>10777-019</td><td>Rnase inhbitor</td></tr><tr><td>Rnase Away</td><td>Ambion</td><td>10328-011</td><td>General Rnase inactivator</td></tr><tr><td>HPLC grade water</td><td>Fisher</td><td>W5-4</td><td>For washing homogenizer blades</td></tr><tr><td>Molecular biology grade water</td><td>Hyclone</td><td>SH30538.03</td><td>Elution of RNA</td></tr><tr><td>miRNeasy Mini kit</td><td>Qiagen</td><td>217004</td><td>Purification Kit</td></tr><tr><td>2 ml microcentrifuge tubes, certified Rnase Dnase free</td><td>USA Scientific Plastics</td><td>1620-2700</td><td></td></tr><tr><td>15 ml centrifuge tubes</td><td>Falcon</td><td>352099</td><td></td></tr><tr><td>70% ethanol</td><td>Fisher</td><td></td><td></td></tr><tr><td>100% ethanol</td><td>Fisher</td><td></td><td></td></tr><tr><td>200 &amp;micro;l pipet tips</td><td>Rainin</td><td>GPL200F</td><td>For cleaning homogenizer blades</td></tr><tr><td>Chloroform</td><td>Fisher</td><td>BP1145-1</td><td></td></tr><tr><td>Nanodrop</td><td>Thermo</td><td>ND-1000</td><td>Spectrophotometer</td></tr><tr><td>Bioanalyzer</td><td>Agilent</td><td></td><td>Capillary electrophoresis analyzer to measue RNA integrity</td></tr><tr><td>RNAlater</td><td>Ambion</td><td></td><td>RNA Stabilization Reagent&amp;nbsp;</td></tr><tr><td>RNeasy&amp;nbsp;spin columns&amp;nbsp;</td><td>Qiagen</td><td></td><td>Spin columns&amp;nbsp;as a part of the miRNeasy Mini kit</td></tr><tr><td>Mice</td><td>Chales River</td><td>Strain C57BL/6</td><td>Their age ranged from 4 to 12 months.&amp;nbsp;&amp;nbsp;</td></tr><tr><td>Mice&amp;nbsp;</td><td>Jackson Lab</td><td>strain 129</td><td>Their age ranged from 4 to 12 months.&amp;nbsp;&amp;nbsp;</td></tr></tbody></table>

rna isolation from mouse pancreas: a ribonuclease-rich tissue

Isolation of high-quality RNA from ribonuclease-rich tissue such as mouse pancreas presents a challenge. As a primary function of the pancreas is to aid in digestion, mouse pancreas may contain as much a 75 mg of ribonuclease. We report modifications of standard phenol/guanidine thiocyanate lysis reagent protocols to isolate RNA from mouse pancreas. Guanidine thiocyanate is a strong protein denaturant and will effectively disrupt the activity of ribonuclease under most conditions. However, critical modifications to standard protocols are necessary to successfully isolate RNA from ribonuclease-rich tissues. Key steps include a high lysis reagent to tissue ratio, removal of undigested tissue prior to phase separation and inclusion of a ribonuclease inhibitor to the RNA solution. Using these and other modifications, we routinely isolate RNA with RNA Integrity Number (RIN) greater than 7. The isolated RNA is of suitable quality for routine gene expression analysis. Adaptation of this protocol to isolate RNA from ribonuclease rich tissues besides the pancreas should be readily achievable.

El rendimiento total de ARN a partir de 1 ml de homogeneizado de lisis es 20-40 mg. OD 260/280 ratios son típicamente alrededor de 2.0 y el RIN son consistentemente superior a 7,0. Si el RIN es ≤ 6, será necesario repetir el aislamiento. De vez en cuando, se consigue un RIN que es mayor que 8,0. Los dos métodos más utilizados de la eutanasia de los ratones antes de la extracción del páncreas son asfixia de CO 2 o la inhalación de isoflurano. Ambas técnicas son seguidos p...

Watch this Scientific Journal Video about RNA Isolation from Mouse Pancreas: A Ribonuclease-rich Tissue at JoVE.com

RNA Isolation from Mouse Pancreas: A Ribonuclease-rich Tissue

We report a procedure to isolate RNA with high integrity from the ribonuclease rich mouse pancreas.

Aislamiento de ARN de ratón Páncreas: Un tejido de ribonucleasa-rica

Isolation of high-quality RNA from ribonuclease-rich tissue such as mouse pancreas presents a challenge.  As a primary function of the pancreas is to aid ...

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27.5K vistas.  The Ohio State University. We report a procedure to isolate RNA with high integrity from the ribonuclease rich mouse pancreas.

Video: RNA Isolation from Mouse Pancreas: A Ribonuclease-rich Tissue

Murine Pancreatic Islet Isolation

Hi, I am Greg Zott. I'm with the UCSF Diabetes Center in the Bluestone Laboratory, and today I'm gonna show you the process for isolating mouse eyelets. The procedure involves the injection of a collagenase solution into the pancreas of a C3 H donor mouse, where we will then remove that pancreas, digest it away, purify the eyelets on a fial gradient, and then handpick them for ultimate transplant into the kidney capsule of a diabetic NOD mouse, Which will be our recipient.Before we start this procedure, we diluted our ATE solution in a modified Hanks buffer and we have adjusted the concentration specific for the strain of mouse that we're using the C3 H.We found digests better at a 0.8 mgs per mil collagenase solution, and we will use that to inject into the common bile duct to distend the pancreas.Performing. The procedure today Will be Pavo codre of the diabetes center. He will inject, open up the mouse, expose the the intestines, and then inject into the common bile duct.We will spray down the mouse with ethanol to keep the hair down, and then we will also verify that the mouse has been sacrificed properly with a toe pinch. Pavo will now open up the mouse and exposing the intestine and the pancreas with a midline incision. The diaphragm will also be cut to verify that the mouse will be sacrificed.Before we get started, I'd like to point out some of the important structures. The stomach is lying right here with the pancreas attached underneath into the duodenum and above. This is the liver where we'll find the gallbladder and the common bile duct, which you can see right here.So what Pavo will do next is he will isolate the small intestine, find where the common bile duct enters the small intestine. Once the intestine is exposed, we clamp on either side of the common bile duct with mosquito clamps. We find that this allows more collagenates to enter the pancreas while other groups try to direct the clamp on top of the common bile duct.We find that this is a better technique in allowing enzyme to enter the pancreas. This is a gentle procedure. You don't want to tear the bowel.You wanna allow the clamps to lie gently on either side of the common bile duct. Now we will find a gallbladder, and once the gallbladder's exposed, we will use that as a guide to injecting the collagenase into the common bile duct. Powell's using a 30 gauge needle with a five cc syringe containing three mills of collagenase solution.As he's entering the common bile duct, he's distending that duct with collagenase solution and then he travels down the common bile duct till he reaches near the intestine. And as he's going down, the enzyme solutions being pumped into the injected into the pancreas. Now that the pancreas is inflated with collagenase solution, Powell's gonna remove the hemostats and then remove the pancreas from the the mouse carefully tearing it away from the intestine.He removes it from the stomach. Okay, and then using the spleen as a handle, he lifts up the pancreas and then slowly snips it away in the common bile duct, and that's it. Pancreas is laid out and then the spleen is removed, and there he's removing the meso enteric tissue, and then the pancreas is placed in a two mill collagenase solution and a sterilized glass vial and it's placed back on Ice.The isolated pancreas that we put into the glass vials will now be placed into a 37 degree water bath for approximately 17 minutes. We placed them into a 50 mil conical rack so that they don't float up. Once during the bath, the timer starts and the digestion begins.Once the digestion time is completed, vials are removed, and then they are shaken and disrupted gently. And once the tissue starts falling apart, the vial is then placed on ice. A sterile screen is placed over a 400 mil beaker that contains washing buffer.The pancreas digest is then carefully poured over the screen into the wash buffer. For demonstration purposes, the hood has been turned off and the glass of the hood has been raised so we could see what we're doing. Once the pancreas digest is poured into the beaker, the vials are rinsed with the same washing buffer and the wash buffer placed over the screen.We have a syringe filled with washing buffer. We will use that to forcefully wash the tissue through the screen. The idea is to release any loose eyelets that are unattached to the matrix, but leaving the membranes and the undigested tissue on the screen.And when you're finished washing a tissue, this is what you usually See at the end of the procedure. The Pancreas tissue that's in the bottom of the tube will now be transferred to two 50 mil conical, and the tissue will be washed, the tissue's mixed evenly, and then distributed evenly so that we have a equal pellet volume in each tube. The beaker is now rinsed with more washing buffer.The sides are rinse so that you get all tissue that is entered the beaker again. Then it's equally distributed between each two, both 50 mil. Conical then are topped off with wash buffer.The tissue is inverted several times and then placed into a centrifuge. This is a quick spin. The centrifuge is allowed to reach a thousand RPM and then is turned off.The tissue at this time is very S eyelets are very sensitive, and you don't want to over compact them. The tubes are removed and we will do this wash step three more times. This is the end of the third wash.The components of the 50 mil conical tube are transferred to the 15 conical tube and centrifuge for a thousand RP M and then stopped. The supernat will be removed and the first part of the FI Call will be started. We are at the step where we Have our pelleted di pancreas digest.We'll resuspend that tissue so it's nice and loose to the pellets. We'll add the first density gradient, which is 1 1 0 8. We'll add five mils to each tube.The pellet is then mixed thoroughly in each of the gradients. It's important that you get good tissue distribution in your heaviest gradient. Now we will layer two mils of 1 0 9 6 density.We will then on top of that, layer two mils of 1 0 6 9 density, and then on top of that 1 0 3 7 density. It's important while you're layering the densities that you don't mix. Then all the layers have been added to the tube.And you can see this is the top of 1 1 0 8, the top of 9 1 0 9 6, the top of 1 0 6 9 and the top of 1 0 3 7. And you could see the tissue is already starting to move to its proper density even without centri fusion. The fial gradients are brought up to speed at 1800 RPM for 15 minutes, and remember to keep the brake off after the tubes are removed from the centrifuge.You can see between the 0 0 9 6 and 0 0 7 layer, there's a nice band of eyelet tissue Pablo's. Now removing the 0 3 7 layer to remove any tissue debris and DNA that might have been released during the processing. Using a sterile plastic pasture pipette, he will now remove the islet layer and transfer them to a 50 mil conical containing 25 mils of wash buffer.You want do this step quickly because fol is toxic to eyelets. We actually removed the entire 0 6 9 and 0 9 6 layer. Pavo cuts the top of the plastic pasture pipette and rinses it with wash buffer.The eyelets are then centrifuge like we centrifuge previously. Centrifuge is brought up to a Thousand RPM and then we stop it and We aspirate off. The supernatant eyelets will be washed three times with wash media.So we just completed the eyelid Isolation process we took from the digest to the fol gradient to the purified eyelets after our third wash with wash buffer, we resuspended the eyelets in our RPMI media and we played it in a tissue culture plate. These eyelets are now ready for in vitro assays or in vivo preps like eyelet Transplant.

Páncreas murino aislamiento Islet

Investigación

Biología

In Vitro Colony Assays for Characterizing Tri-potent Progenitor Cells Isolated from the Adult Murine Pancreas

Stem and progenitor cells from the adult pancreas could be a potential source of therapeutic beta-like cells for treating patients with type 1 diabetes. However, it is still unknown whether stem and progenitor cells exist in the adult pancreas. Research strategies using cre-lox lineage-tracing in adult mice have yielded results that either support or refute the idea that beta cells can be generated from the ducts, the presumed location where adult pancreatic progenitors may reside. These in vivo cre-lox lineage-tracing methods, however, cannot answer the questions of self-renewal and multi-lineage differentiation-two criteria necessary to define a stem cell. To begin addressing this technical gap, we devised 3-dimensional colony assays for pancreatic progenitors. Soon after our initial publication, other laboratories independently developed a similar, but not identical, method called the organoid assay. Compared to the organoid assay, our method employs methylcellulose, which forms viscous solutions that allow the inclusion of extracellular matrix proteins at low concentrations. The methylcellulose-containing assays permit easier detection and analyses of progenitor cells at the single-cell level, which are critical when progenitors constitute a small sub-population, as is the case for many adult organ stem cells. Together, results from several laboratories demonstrate in vitro self-renewal and multi-lineage differentiation of pancreatic progenitor-like cells from mice. The current protocols describe two methylcellulose-based colony assays to characterize mouse pancreatic progenitors; one contains a commercial preparation of murine extracellular matrix proteins and the other an artificial extracellular matrix protein known as a laminin hydrogel. The techniques shown here are 1) dissociation of the pancreas and sorting of CD133+Sox9/EGFP+ ductal cells from adult mice, 2) single cell manipulation of the sorted cells, 3) single colony analyses using microfluidic qRT-PCR and whole-mount immunostaining, and 4) dissociation of primary colonies into single-cell suspensions and re-plating into secondary colony assays to assess self-renewal or differentiation.

In Vitro Colony Assays for Characterizing Tri-potent Progenitor Cells Isolated from the Adult Murine Pancreas

In vitro colony assays to detect self-renewal and differentiation of progenitor cells isolated from adult murine pancreas are devised. In these assays, pancreatic progenitors give rise to cell colonies in 3-dimensional space in methylcellulose-containing semi-solid medium. Protocols for handling single cells and characterization of individual colonies are described.

Los ensayos in vitro de colonias para la caracterización de células progenitoras Tri-potentes Aislado de los murinos adultos Páncreas

Stem and progenitor cells from the adult pancreas could be a potential source of therapeutic beta-like cells for treating patients with type 1 diabetes. ...

Biología del Desarrollo

Effective Isolation of Functional Islets from Neonatal Mouse Pancreas

Perfusion-based islet-isolation protocols from large mammalian pancreata are well established. Such protocols are readily conducted in many laboratories due to the large size of the pancreatic duct that allows for ready collagenase injection and subsequent tissue perfusion. In contrast, islet isolation from small pancreata, like that of neonatal mice, is challenging because perfusion is not readily achievable in the small pancreata. Here we describe a detailed simple procedure that recovers substantial numbers of islets from newly born mice with visual assistance. Freshly dissected whole pancreata were digested with 0.5 mg/mL collagenase IV dissolved in Hanks&#39; Balanced Salt Solution (HBSS) at 37 &#176;C, in microcentrifuge tubes. Tubes were tapped regularly to aid tissue dispersal. When most of the tissue was dispersed to small clusters around 1 mm, lysates were washed three to four times with culture media with 10% fetal bovine serum (FBS). Islet clusters, devoid of recognizable acinar tissues, can then be recovered under dissecting stereoscope. This method recovers 20 - 80 small- to large-sized islets per pancreas of newly born mouse. These islets are suitable for most conceivable downstream assays, including insulin secretion, gene expression, and culture. An example of insulin secretion assay is presented to validate the isolation process. The genetic background and degree of digestion are the largest factors determining the yield. Freshly made collagenase solution with high activity is preferred, as it aids in endocrine-exocrine isolation. The presence of cations [calcium (Ca2+) and magnesium (Mg2+)] in all solutions and fetal bovine serum in the wash/picking media are necessary for good yield of islets with proper integrity. A dissecting scope with good contrast and magnification will also help.

We describe a protocol herein for isolating intact islets from neonatal mice. Pancreata were partially digested with collagenase, followed by washing and hand picking. 20 - 80 islet clusters can be obtained per pancreas from newly born mice, which are suitable for several islet studies.

El aislamiento efectivo de los islotes funcionales de páncreas de ratón neonatales

Perfusion-based islet-isolation protocols from large mammalian pancreata are well established. Such protocols are readily conducted in many laboratories ...

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

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

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

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

Lepr<sup&gt; Db</sup&gt; Modelo de ratón de la Diabetes Tipo 2: El aislamiento de los islotes pancreáticos y células en Vivo 2-Photon imágenes de islotes intactos

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

Medicina

Intraportal Transplantation of Pancreatic Islets in Mouse Model

Pancreatic islet transplantation to reduce hyperglycemia is highly successful in rodents with chemically-induced diabetes. The most common transplantation site in experimental islet transplantation is the kidney capsule. However, as less is known about the interaction of pancreatic islets with blood constituents, it also makes sense to utilize the portal vein approach in experimental islet transplantation.
This protocol demonstrates an intraportal islet transplantation technique in NMRI nude mice. Streptozotocin (180 mg/kg) is injected intraperitoneally to induce hyperglycemia in recipient mice. They are considered as diabetic at a non-fasting blood glucose level greater than 20 mmol/L. One day prior to transplantation, mouse pancreatic islets are isolated from the donor pancreas by collagenase digestion; a minimum of 350 islets are utilized per diabetic recipient. Depending upon the islet isolation yield, two or more donor mice are utilized per recipient. After overnight culture at 37 &#176;C, islets are administered into the recipient liver via the portal vein. After surgery, the mice are protected in red Makrolon houses and observed until are awake. This protocol maintains glycemic control for 120 days in syngeneic mice and 15 days in allogeneic mice.

Pancreatic islet transplantation is a way to achieve normoglycemia in type 1 diabetes. This article focuses on the transplantation technique through the intraportal route to maintain normal glucose levels in diabetic mice.

Intraportal trasplante de islotes pancreáticos en modelo murino

Pancreatic islet transplantation to reduce hyperglycemia is highly successful in rodents with chemically-induced diabetes. The most common transplantation ...

A Method for Mouse Pancreatic Islet Isolation and Intracellular cAMP Determination

Uncontrolled glycemia is a hallmark of diabetes mellitus and promotes morbidities like neuropathy, nephropathy, and retinopathy. With the increasing prevalence of diabetes, both immune-mediated type 1 and obesity-linked type 2, studies aimed at delineating diabetes pathophysiology and therapeutic mechanisms are of critical importance. The &#946;-cells of the pancreatic islets of Langerhans are responsible for appropriately secreting insulin in response to elevated blood glucose concentrations. In addition to glucose and other nutrients, the &#946;-cells are also stimulated by specific hormones, termed incretins, which are secreted from the gut in response to a meal and act on &#946;-cell receptors that increase the production of intracellular cyclic adenosine monophosphate (cAMP). Decreased &#946;-cell function, mass, and incretin responsiveness are well-understood to contribute to the pathophysiology of type 2 diabetes, and are also being increasingly linked with type 1 diabetes. The present mouse islet isolation and cAMP determination protocol can be a tool to help delineate mechanisms promoting disease progression and therapeutic interventions, particularly those that are mediated by the incretin receptors or related receptors that act through modulation of intracellular cAMP production. While only cAMP measurements will be described, the described islet isolation protocol creates a clean preparation that also allows for many other downstream applications, including glucose stimulated insulin secretion, [3H]-thymidine incorporation, protein abundance, and mRNA expression.

Assaying in vitro &#946;-cell function using isolated mouse islets of Langerhans is an important component in the study of diabetes pathophysiology and therapeutics. While many&#160;downstream applications are available, this protocol specifically describes the measurement of intracellular cyclic adenosine monophosphate (cAMP) as an essential parameter determining &#946;-cell function.

Un método para ratón islotes pancreáticos Aislamiento y cAMP intracelular Determinación

Uncontrolled glycemia is a hallmark of diabetes mellitus and promotes morbidities like neuropathy, nephropathy, and retinopathy. With the increasing ...

Isolation and Culture of Mouse Primary Pancreatic Acinar Cells

This protocol permits rapid isolation (in less than 1 hr) of murine pancreatic acini, making it possible to maintain them in culture for more than one week. More than 20 x 106 acinar cells can be obtained from a single murine pancreas. This protocol offers the possibility to independently process as many as 10 pancreases in parallel. Because it preserves acinar architecture, this model is well suited for studying the physiology of the exocrine pancreas in vitro in contrast to cell lines established from pancreatic tumors, which display many genetic alterations resulting in partial or total loss of their acinar differentiation.

In this publication, we describe a rapid and convenient procedure for isolating and culturing primary pancreatic acinar cells from the murine pancreas. This method constitutes a valuable approach to study the physiology of fresh primary normal/untransformed exocrine pancreatic cells.

Aislamiento y cultivo de ratón primarias células acinares pancreáticas

This protocol permits rapid isolation (in less than 1 hr) of murine pancreatic acini, making it possible to maintain them in culture for more than one ...

A Simple High Efficiency Protocol for Pancreatic Islet Isolation from Mice

Pancreatic islets, also called the Islets of Langerhans, are a cluster of endocrine cells which produces hormones for glucose regulation and other important biological functions. The islets primarily consist of five types of hormone-secreting cells: &#945; cells secrete glucagon, &#946; cells secrete insulin, &#948; cells secrete somatostatin, &#949; cells secrete ghrelin, and PP cells secrete pancreatic polypeptide. Sixty to 80% of the cells in the islets are &#946; cells, which are the most important cell population to study insulin secretion. Pancreatic islets are a crucial model system to study ex vivo insulin secretion. Acquiring high quality islets is of great importance for diabetes research. Most islet isolation procedures require technically difficult to access site of collagenase injection, harsh and complex digestion procedures, and multiple density gradient purification steps. This paper features a simple high yield mouse islet isolation method with detailed descriptions and realistic demonstrations, showing the following specific steps: 1) injection of collagenase P at the ampulla of Vater, a small area joining the pancreatic duct and the common bile duct, 2) enzymatic digestion and mechanical separation of the exocrine pancreas, and 3) a single gradient purification step. The advantages of this method are the injection of digestive enzyme using the more accessible ampulla of Vater, more complete digestion using combination of enzymatic and mechanical approaches, and a simpler single gradient purification step. This protocol produces approximately 250&#8212;350 islets per mouse; and islets are suitable for various ex vivo studies. Possible caveats of this procedure are potentially damaged islets due to enzymatic digestion and/or prolonged gradient incubation, all of which can be largely avoided by careful ad justification of incubation time.

This islet isolation protocol described a novel route of collagenase injection to digest the exocrine tissue and a simplified gradient procedure to purify the islets from mice. It involves enzymatic digestion, gradient separation/purification, and islet hand-picking. Successful isolation can yield 250&#8211;350 high quality and fully functional islets per mouse.

Un protocolo simple de alta eficiencia para el aislamiento de islotes pancreáticos de ratones

Pancreatic islets, also called the Islets of Langerhans, are a cluster of endocrine cells which produces hormones for glucose regulation and other ...

Imaging Calcium Dynamics in Subpopulations of Mouse Pancreatic Islet Cells

Pancreatic islet hormones regulate blood glucose homeostasis. Changes in blood glucose induce oscillations of cytosolic calcium in pancreatic islet cells that trigger secretion of three main hormones: insulin (from &#946;-cells), glucagon (&#945;-cells) and somatostatin (&#948;-cells). &#946;-Cells, which make up the majority of islet cells and are electrically coupled to each other, respond to the glucose stimulus as one single entity. The excitability of the minor subpopulations, &#945;-cells and &#948;-cells (making up around 20% (30%) and 4% (10%) of the total rodent1 (human2) islet cell numbers, respectively) is less predictable and is therefore of special interest.
Calcium sensors are delivered into the peripheral layer of cells within the isolated islet. The islet or a group of islets is then immobilized and imaged using a fluorescence microscope. The choice of the imaging mode is between higher throughput (wide-field) and better spatial resolution (confocal). Conventionally, laser scanning confocal microscopy is used for imaging tissue, as it provides the best separation of the signal between the neighboring cells. A wide-field system can be utilized too, if the contaminating signal from the dominating population of &#946;-cells is minimized.
Once calcium dynamics in response to specific stimuli have been recorded, data are expressed in numerical form as fluorescence intensity vs. time, normalized to the initial fluorescence and baseline-corrected, to remove the effects linked to bleaching of the fluorophore. Changes in the spike frequency or partial area under the curve (pAUC) are computed vs. time, to quantify the observed effects. pAUC is more sensitive and quite robust whereas spiking frequency provides more information on the mechanism of calcium increase.
Minor cell subpopulations can be identified using functional responses to marker compounds, such as adrenaline and ghrelin, that induce changes in cytosolic calcium in a specific populations of islet cells.

Here, we present a protocol for imaging and quantifying calcium dynamics in heterogeneous cell populations, such as pancreatic islet cells. Fluorescent reporters are delivered into the peripheral layer of cells within the islet, which is then immobilized and imaged, and per-cell analysis of the dynamics of fluorescence intensity is performed.

Imagen de la dinámica del calcio en subpoblaciones de células de islotes pancreáticos de ratón

Pancreatic islet hormones regulate blood glucose homeostasis. Changes in blood glucose induce oscillations of cytosolic calcium in pancreatic islet cells ...

<meta charset="utf8"></head><body>Optimización de la extracción de células endoteliales pancreáticas de ratón para estudios de enfermedades

Isolation of Mouse Pancreatic Endothelial Cells

The pancreas is a vital organ for maintaining metabolic balance within the body, in part due to its production of metabolic hormones such as insulin and glucagon, as well as digestive enzymes. The pancreas is also a highly vascularized organ, a feature facilitated by the intricate network of pancreatic capillaries. This extensive capillary network is made up of highly fenestrated endothelial cells (ECs) important for pancreas development and function. Accordingly, the dysfunction of ECs can contribute to that of the pancreas in diseases like diabetes and cancer. Thus, researching the function of pancreatic ECs (pECs) is important not only for understanding pancreas biology but also for developing its pathologies. Mouse models are valuable tools to study metabolic and cardiovascular diseases. However, there has not been an established protocol with sufficient details described for the isolation of mouse pECs due to the relatively small population of ECs and the abundant digestive enzymes potentially released from the acinar tissue that can lead to cell damage and, thus, low yield. To address these challenges, we devised a protocol to enrich and recover mouse pECs, combining gentle physical and chemical dissociation and antibody-mediated selection. The protocol presented here provides a robust method to extract intact and viable ECs from the whole mouse pancreas. This protocol is suitable for multiple downstream assays and may be applied to various mouse models.

<meta charset="utf8"></head><body>Aislamiento de células endoteliales pancreáticas de ratón

This protocol describes the isolation of mouse endothelial cells from whole pancreas.

Aislamiento de células endoteliales pancreáticas de ratón

The pancreas is a vital organ for maintaining metabolic balance within the body, in part due to its production of metabolic hormones such as insulin and ...