Apoyado con fondos de la Universidad de Illinois en Chicago, así como células de los islotes del Centro de Recursos NIH (RFA-05-003 RR), la Fundación Christopher, la Fundación Efroymson, y la Fundación Tellabs.

1. Facilidad de configuración <ol><li> El aislamiento de islotes humanos es un procedimiento sensible al tiempo que implica el trabajo en equipo, y por lo tanto, cuatro personas se necesitan para llevar a cabo este procedimiento. El equipo está liderado por el cirujano, que disecciona y cannulates el páncreas. </li><li> El aislamiento de islotes comienza en el momento que el equipo entra en la instalación de aislamiento de islotes UIC. Miembros del equipo de asegurarse de que todos los instrumentos necesarios, como la centrífuga, se comprueba y se enciende. También asegúrese de desinfectar todas las campanas y las superficies. </li><li> Dos personas se creó la mesa de la canalización, máquina granizado, el circuito de la digestión, la unidad de la perfusión, la máquina de purificación de COBE, y mesas quirúrgicas. </li><li> Al mismo tiempo, dos miembros del equipo preparará los medios de comunicación que se necesita durante el aislamiento. </li><li> A continuación, los tubos de la bacteriología (botellas, tubos, la forma y la bolsa), los tubos de muestreo (pre-llenado con lavado), y los tubos de evaluación y las placas están preparadas. </li><li> Prepare el tubo de depuración establecidos de la siguiente manera: El tubo de vacío y primera marca de 150 ml, tubos de 2.12 con 200 ml de M199 medios suplementados con albúmina humana (solución de lavado) y marcados con 230 ml y, finalmente, un tubo de 50 ml cónicos llena con 50 ml de solución de lavado. Una vez que estos pasos de preparación se completa estamos listos para empezar a preparar la perfusión y el páncreas. </li></ol> 2. Páncreas preparación y la perfusión <ol><li> Para comenzar la preparación y la perfusión del páncreas, un operario retira el órgano de los envases utilizando una técnica estéril. El cirujano de transferencia de páncreas a la mesa de la descontaminación. </li><li> El cirujano llenar una jeringa de 60 ml con la solución de preservación de páncreas original y entregarlo a un operador, que se utiliza para rellenar preparado &quot;Adquisiciones&quot; botellas de bacteriología. </li><li> Después de una inspección visual para determinar si el órgano es adecuado para el aislamiento de los islotes (Si el páncreas está dañado durante la adquisición o anormal anatómica, no se puede utilizar para el aislamiento de los islotes), el cirujano le preguntará al operador preparar la colagenasa. Recuerde que el tiempo que re-suspensión varía entre las marcas de enzimas diferentes y mucho. </li><li> Cuando el cirujano está listo, poner las soluciones de descontaminación (Betadine, Fungizone / cefazolina y HBSS) a la mesa de la descontaminación y verter en los contenedores apropiados. Cirujano realiza la descontaminación del páncreas de lavado de un minuto, el páncreas en cada una de las soluciones de descontaminación. El páncreas se coloca en un pequeño frasco estéril en el que se pesaba. Después de que el peso se introduce en el registro del lote, el páncreas se coloca en la bandeja de la canalización con alguna solución de preservación. </li><li> El cirujano exponer y cortar parcialmente el conducto principal y canular cada mitad del páncreas con una cánula. La cánula se asegura con sutura. Para la perfusión del páncreas, en primer lugar pasar a la unidad de la perfusión y se vierte la solución de la enzima en la cuenca. Tiempo de perfusión total es de unos 10 minutos, a 80 mmHg durante 5 minutos, luego a 180 mmHg durante 5 minutos. Páncreas distendido después de la perfusión. </li><li> Mueva el páncreas perfundido a la sartén la canalización, donde se recorta el tejido graso del páncreas con cuidado. A continuación, corte el páncreas en 10-12 piezas y traslado a Ricordi Cámara para la digestión. </li></ol> 3. Páncreas digestión <ol><li> Para empezar a paso de digestión, el páncreas para la transferencia de la cámara de Ricordi vacía, añadir un 2,5 ml frasco de Pulmozyme, poner en la pantalla (evitar gran parte de bloque de tejido de la cámara), cerca de la cámara, y llenar el sistema. </li><li> Comenzar a bombear la solución durante 5 minutos. Agite suavemente la cámara para dispersar uniformemente la solución caliente a través. Después de cinco minutos, agitar suavemente la cámara para la fase de digestión de todo. Mantener la temperatura a 37 ˚ C. </li><li> Roca de la cámara suavemente hasta que la temperatura alcanza los 37 °, se sacude la cámara. Tomar una muestra cada dos minutos y detectar si islotes libres se encuentran bajo el ámbito de aplicación. Registrar la información de la evaluación de los islotes en la mesa de la digestión del registro del lote. Seguir para determinar el porcentaje de islotes hasta que haya un 50% de ellos flotando libremente y aislado en la solución. </li></ol> 4. Tejido colección <ol><li> Una vez que el 50% de los islotes se encuentran libres en las muestras, la digestión se detiene mediante la adición de una solución fría de dilución RPMI en el circuito. Tejido se recoge en 500 ml tubos cónicos precargada con 30 ml de albúmina humana. Una vez que los tubos se hacen girar, aspiración el sobrenadante y lavar el precipitado con solución de lavado en frío. Girar los tubos cónicos a 1100 RPM (revoluciones por minuto) durante 1 minuto, 4 ˚ C. </li><li> Combine todos los tubos de recogida de suspensión de tejido pancreático digieren en un solo cónico de 500 ml. Cuando el tubo está lleno de tejido lavado, centrifugado y repita el proceso de lavado hasta que todo el tejido ha sido lavada varias veces. Girar el tubo y la transferencia de los tejidos en un solo tubo de 250 ml cónico. Llevar el volumen hasta 250 ml conM199 solución de lavado suplementado con HA y prepararse para el muestreo. </li><li> Tomar una muestra de 1 ml con una pipeta y se añade a un tubo cónico de 15 ml precargada con 9 ml de solución de lavado. A continuación, mezclar suavemente invirtiendo el tubo cónico de 15 ml y de esto, la muestra de 1 ml directamente en una placa de red de conteo. Contar las células, y calcular el número de células con un factor de dilución de 2500 (10x250). </li><li> Girar el tubo de 250 ml y añadir 150 ml de la Universidad de Washington (Universidad de Wisconsin), solución que suele utilizar para la preservación de órganos. Cuando la Universidad de Washington, se añade, mezcla de la suspensión celular a fondo con la pipeta. Registrar y comunicar al operador de la purificación, el tiempo de inicio en la Universidad de Washington. Deje el tubo (s) en el hielo y agitar de vez en cuando. Ahora los islotes se pueden purificar aún más. </li></ol>

<ol>
	<li>Shapiro, A. 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=Islet+transplantation+in+seven+patients+with+type+1+diabetes+mellitus+using+a+glucocorticoid-free+immunosuppressive+regimen.">Islet transplantation in seven patients with type 1 diabetes mellitus using a glucocorticoid-free immunosuppressive regimen.</a> N Engl J Med. 343, 230-238 (2000).</li><li>Nano, 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=Islet+isolation+for+allotransplantation:+variables+associated+with+successful+islet+yield+and+graft+function.">Islet isolation for allotransplantation: variables associated with successful islet yield and graft function.</a> Diabetologia. 48, 906-912 (2005).</li><li>Barbaro, B., 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=Improved+human+pancreatic+islet+purification+with+the+refined+UIC-UB+density+gradient.">Improved human pancreatic islet purification with the refined UIC-UB density gradient.</a> Transplantation. 84, 1200-1203 (2007).</li><li>Lakey, J. R., Rajotte, R. V., Warnock, G. L., Kneteman, N. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+pancreas+preservation+prior+to+islet+isolation.+Cold+ischemic+tolerance.">Human pancreas preservation prior to islet isolation. Cold ischemic tolerance.</a> Transplantation. 59, 689-694 (1995).</li><li>Fridell, J. A., 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=Comparison+of+histidine-tryptophan-ketoglutarate+solution+and+University+of+Wisconsin+solution+for+organ+preservation+in+clinical+pancreas+transplantation.">Comparison of histidine-tryptophan-ketoglutarate solution and University of Wisconsin solution for organ preservation in clinical pancreas transplantation.</a> Transplantation. 77, 1304-1306 (2004).</li><li>Potdar, 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=Initial+experience+using+histidine-tryptophan-ketoglutarate+solution+in+clinical+pancreas+transplantation.">Initial experience using histidine-tryptophan-ketoglutarate solution in clinical pancreas transplantation.</a> Clin Transplant. 18, 661-665 (2004).</li><li>Salehi, P., 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=Human+islet+isolation+outcomes+from+pancreata+preserved+with+Histidine-Tryptophan+Ketoglutarate+versus+University+of+Wisconsin+solution.">Human islet isolation outcomes from pancreata preserved with Histidine-Tryptophan Ketoglutarate versus University of Wisconsin solution.</a> Transplantation. 82, 983-985 (2006).</li><li>Ricordi, C., Lacy, P. E., Scharp, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Automated+islet+isolation+from+human+pancreas.">Automated islet isolation from human pancreas.</a> Diabetes. 38, 140-142 (1989).</li><li>Hanley, S. C., Paraskevas, S., Rosenberg, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Donor+and+isolation+variables+predicting+human+islet+isolation+success.">Donor and isolation variables predicting human islet isolation success.</a> Transplantation. 85, 950-955 (2008).</li><li>Toso, C., 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=Factors+affecting+human+islet+of+Langerhans+isolation+yields.">Factors affecting human islet of Langerhans isolation yields.</a> Transplant Proc. 34, 826-827 (2002).</li></ol>

Hay una variedad de factores que afectan el resultado de aislamiento 9,10. Entre ellos, la digestión del tejido pancreático desempeña un papel destacado. Con base en nuestra propia experiencia humana aislamiento de islotes, se resumieron los siguientes puntos críticos, que podrían influir en el rendimiento y la calidad de los islotes. <ol><li> El tiempo de digestión es diferente cuando los diferentes tipos de enzimas que se utilizan. </li><li> Tan pronto como el 40-50% de los islotes completamente separados de...

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<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">	
		
		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Ice Slush Machine</td>
<td>equipment</td>
<td>Taylor Company</td>
<td>K4036546</td>
<td>make sterile ice</td>
</tr>
<tr>
<td>Centrifuge</td>
<td>equipment</td>
<td>Beckman Coulter</td>
<td>424803</td>
<td>&nbsp;</td>
<tr>
<td>MZ6 Inverted Microscopy TLBD4.1</td>
<td>equipment</td>
<td>Leica Diagnostic Instrument Co</td>
<td>4103</td>
<td>&nbsp;</td>
<tr>
<td>Cell Culture Dish with 2 mm Grid</td>
<td>equipment</td>
<td>Nunc Brand Products</td>
<td>174926</td>
<td>islet counting</td>
</tr>
<tr>
<td>Digital Water Bath EX7</td>
<td>equipment</td>
<td>NesLab</td>
<td>105361058</td>
<td>&nbsp;</td>
<tr>
<td>Thermometer</td>
<td>equipment</td>
<td>IBI:IR</td>
<td>60444</td>
<td>&nbsp;</td>
<tr>
<td>MonoBloc Balance AB 104-S</td>
<td>equipment</td>
<td>Metler Toledo</td>
<td>1119430864</td>
<td>measure pancreas weight</td>
</tr>
<tr>
<td>MasterFlex II Speed Controller</td>
<td>equipment</td>
<td>Cole Parmer Instrument Co</td>
<td>J00006445</td>
<td>adjust flow speed during degestion</td>
</tr>
<tr>
<td>Digital Sight DS L1</td>
<td>equipment</td>
<td>Nikon</td>
<td>217267</td>
<td>&nbsp;</td>
<tr>
<td>Perfusion Unit</td>
<td>equipment</td>
<td>Custom Made/Swiss</td>
<td>n/a</td>
<td>&nbsp;</td>
<tr>
<td>Cooler for perfusion unit</td>
<td>equipment</td>
<td>Fisher Scientific</td>
<td>3013P</td>
<td>&nbsp;</td>
<tr>
<td>Ricordi Chamber</td>
<td>equipment</td>
<td>University of Miami</td>
<td>n/a</td>
<td>&nbsp;</td>
<tr>
<td>RPMI dilution solution</td>
<td>reagent</td>
<td>Mediatech Inc</td>
<td>99783024</td>
<td>&nbsp;</td>
<tr>
<td>University of Wisconcin (UW) solution</td>
<td>reagent</td>
<td>DURAMED</td>
<td>1000-46-06</td>
<td>&nbsp;</td>
<tr>
<td>Hank's Buffered Salt Solution (HBSS)</td>
<td>reagent</td>
<td>Mediatech Inc</td>
<td>99-597-CM</td>
<td>&nbsp;</td>
<tr>
<td>25% Human Albumin</td>
<td>reagent</td>
<td>GRIFOLS</td>
<td>NDC 61953-0002-2</td>
<td>&nbsp;</td>
<tr>
<td>M199 media (wash solution)</td>
<td>reagent</td>
<td>Mediatech Inc</td>
<td>99-784-CM</td>
<td>&nbsp;</td>
<tr>
<td>Collagenase NB1 GMP grade</td>
<td>reagent</td>
<td>SERVA Electrophoresis</td>
<td>N0002937</td>
<td>&nbsp;</td>
<tr>
<td>Neutral Protease NB1 GMP grade</td>
<td>reagent</td>
<td>SERVA Electrophoresis</td>
<td>N0002936</td>
<td>&nbsp;</td>
<tr>
<td>Betadine</td>
<td>reagent</td>
<td>Cardinal Health</td>
<td>29906-004</td>
<td>&nbsp;</td>
<tr>
<td>Cefazolin</td>
<td>reagent</td>
<td>West-Ward Pharmaceutical</td>
<td>NDC 0143-9924-90</td>
<td>&nbsp;</td>
<tr>
<td>Dithizone</td>
<td>reagent</td>
<td>Sigma </td>
<td>D5130</td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

human pancreatic islet isolation: part i: digestion and collection of pancreatic tissue

Gestión de la diabetes tipo 1 es una carga, tanto para el individuo y la sociedad, con un costo de más de 100 millones de dólares anuales. A pesar del uso generalizado de la monitorización de la glucosa y las nuevas formulaciones de insulina, muchas personas aún se desarrollan devastadoras complicaciones secundarias. El trasplante de islotes pancreáticos puede restaurar un control casi normal a la glucosa en pacientes diabéticos<sup&gt; 1</sup&gt;, Sin el riesgo de episodios hipoglucémicos graves que se asocian a la terapia intensiva de insulina. Proporcionar la masa suficiente de islotes es importante para el trasplante de islotes exitosos. Pero lo más característico de los donantes, la obtención de órganos y la preservación de afectar el resultado de aislamiento<sup&gt; 2</sup&gt;. En la Universidad de Illinois en Chicago (UIC), hemos desarrollado un protocolo de éxito en el aislamiento con un gradiente de depuración mejorada<sup&gt; 3</sup&gt;. El programa se inició en enero de 2004, y más de 300 aislamientos se realizaron hasta noviembre de 2008. El páncreas se enviaron en soluciones de preservación en frío (UW de la Universidad de Wisconsin o HTK, histidina-triptófano-cetoglutarato)<sup&gt; 7.4</sup&gt; Para el Laboratorio de aislamiento de células en la UIC para el aislamiento de los islotes. Islotes pancreáticos fueron aislados usando el método de la UIC, que es una versión modificada del método descrito originalmente por Ricordi<em&gt; Et al</em&gt;<sup&gt; 8</sup&gt;. En pocas palabras, después de limpiar el páncreas del tejido circundante, que fue perfundido con solución enzimática (colagenasa Serva + neutro de la proteasa o enzima Sigma V). El páncreas distendido fue trasladado a la cámara de digestión Ricordi, conectado a una modificación, el sistema de tubería cerrada la circulación, y calentado a 37 ° C. Durante la digestión, la cámara se agita suavemente. Las muestras se toman de forma continua para controlar el progreso de digestión. Una vez islotes libres fueron detectados en el microscopio, la digestión fue detenido por lavado en frío (4 ° C) RPMI solución de dilución (Mediatech, Herndon, VA) en el sistema de circulación para diluir la enzima. Después de ser recogidos y lavados en los medios de comunicación M199 suplementado con albúmina humana, el tejido se tomaron muestras para el recuento de pre-purificación y se incubaron con solución UW antes de la purificación. Proceso de purificación se describe en la Parte II: el saneamiento y la cultura de los islotes.

Watch this Scientific Journal Video about Human Pancreatic Islet Isolation: Part I: Digestion and Collection of Pancreatic Tissue at JoVE.com

Human Pancreatic Islet Isolation: Part I: Digestion and Collection of Pancreatic Tissue

Lograr una alta calidad y la cantidad adecuada de islotes humanos es uno de los requisitos importantes para el trasplante de islotes exitosos. En este video se describe paso a paso los procedimientos para el aislamiento de los islotes pancreáticos humanos (I parte: la digestión y la acumulación de tejido de páncreas), utilizando un método modificado automatizado.

Aislamiento humanos islote pancreático: Parte I: La digestión y la acumulación de tejido pancreático

Management of Type 1 diabetes is burdensome, both to the individual and society, costing over 100 billion dollars annually. Despite the widespread use of ...

human-pancreatic-islet-isolation-part-i-digestion-collection

Research

JoVE Journal

Biology

19.2K vistas.  University of Illinois, Chicago. Lograr una alta calidad y la cantidad adecuada de islotes humanos es uno de los requisitos importantes para el trasplante de islotes exitosos. En este video se describe paso a paso los procedimientos para el aislamiento de los islotes pancreáticos humanos (I parte: la digestión y la acumulación de tejido de páncreas), utilizando un método modificado automatizado.

Video: Human Pancreatic Islet Isolation: Part I: Digestion and Collection of Pancreatic Tissue

Murine Pancreatic Islet Isolation

Páncreas murino aislamiento Islet

Investigación

Biología

Human Pancreatic Islet Isolation: Part II: Purification and Culture of Human Islets

Management of Type 1 diabetes is burdensome, both to the individual and society, costing over 100 billion dollars annually. Despite the widespread use of glucose monitoring and new insulin formulations, many individuals still develop devastating secondary complications. Pancreatic islet transplantation can restore near normal glucose control in diabetic patients 1, without the risk of serious hypoglycemic episodes that are associated with intensive insulin therapy. Providing sufficient islet mass is important for successful islet transplantation. However, donor characteristics, organ procurement and preservation affect the isolation outcome 2. At University of Illinois at Chicago (UIC) we developed a successful isolation protocol with an improved purification gradient 3. The program started in January 2004 and more than 300 isolations were performed up to November 2008. The pancreata were sent in cold preservation solutions (UW, University of Wisconsin or HTK, Histidine-Tryptophan Ketoglutarate) 4-7 to the Cell Isolation Laboratory at UIC for islet isolation. Pancreatic islets were isolated using the UIC method, which is a modified version of the method originally described by Ricordi et al 8. As described in Part I: Digestion and Collection of Pancreatic Tissue, human pancreas was trimmed, cannulated, perfused, and digested. After collection and at least 30 minutes of incubation in UW solution, the tissue was loaded in the cell separator (COBE 2991, Cobe, Lakewood, CO) for purification 3. Following purification, islet yield (expressed as islet equivalents, IEQ), tissue volume, and purity was determined according to standard methods 9. Isolated islets were cultured in CMRL-1066 media (Mediatech, Herndon, VA), supplemented with 1.5% human albumin, 0.1% insulin-transferrin-selenium (ITS), 1 ml of Ciprofloxacin, 5 ml o f 1M HEPES, and 14.5 ml of 7.5% Sodium Bicarbonate in T175 flasks at 37&deg;C overnight culture before islets were transplanted or used for research.

Achieving high quality and appropriate quantity of human islets is one of the prominent prerequisites for successful islet transplantation. In this video, we describe step by step the procedures for human pancreatic islet isolation (part II: purification and culture of human islets) using a modified automated method.

De páncreas humano de aislamiento Islet: Parte II: Purificación y Cultura de los islotes

Isolation of Stem Cells from Human Pancreatic Cancer Xenografts

Cancer stem cells (CSCs) have been identified in a growing number of malignancies and are functionally defined by their ability to undergo self-renewal and produce differentiated progeny1. These properties allow CSCs to recapitulate the original tumor when injected into immunocompromised mice. CSCs within an epithelial malignancy were first described in breast cancer and found to display specific cell surface antigen expression (CD44+CD24low/-)2. Since then, CSCs have been identified in an increasing number of other human malignancies using CD44 and CD24 as well as a number of other surface antigens. Physiologic properties, including aldehyde dehydrogenase (ALDH) activity, have also been used to isolate CSCs from malignant tissues3-5.
Recently, we and others identified CSCs from pancreatic adenocarcinoma based on
ALDH activity and the expression of the cell surface antigens CD44 and CD24, and CD1336-8. These highly tumorigenic populations may or may not be overlapping and display other functions. We found that ALDH+ and CD44+CD24+ pancreatic CSCs are similarly tumorigenic, but ALDH+ cells are relatively more invasive8. In this protocol we describe a method to isolate viable pancreatic CSCs from low-passage human
xenografts9. Xenografted tumors are harvested from mice and made into a single-cell suspension. Tissue debris and dead cells are separated from live cells and then stained using antibodies against CD44 and CD24 and using the ALDEFLUOR reagent,
a fluorescent substrate of ALDH10. CSCs are then isolated by fluorescence activated cell sorting. Isolated CSCs can then be used for analytical or functional assays requiring viable cells.

Cancer stem cells (CSCs) have been identified in a number of malignancies. In this protocol we describe a flow cytometric method utilizing aldehyde dehydrogenase activity and CD44 and CD24 expression to isolate CSCs from human pancreatic adenocarcinoma xenografts. These viable cells can then be used in functional and analytical studies.

El aislamiento de células madre de cáncer de páncreas xenoinjertos

Cancer stem cells (CSCs) have been identified in a growing number of malignancies and are functionally defined by their ability to undergo self-renewal ...

Computer-assisted Large-scale Visualization and Quantification of Pancreatic Islet Mass, Size Distribution and Architecture

The pancreatic islet is a unique micro-organ composed of several hormone secreting endocrine cells such as beta-cells (insulin), alpha-cells (glucagon), and delta-cells (somatostatin) that are embedded in the exocrine tissues and comprise 1-2% of the entire pancreas. There is a close correlation between body and pancreas weight. Total beta-cell mass also increases proportionately to compensate for the demand for insulin in the body. What escapes this proportionate expansion is the size distribution of islets. Large animals such as humans share similar islet size distributions with mice, suggesting that this micro-organ has a certain size limit to be functional. The inability of large animal pancreata to generate proportionately larger islets is compensated for by an increase in the number of islets and by an increase in the proportion of larger islets in their overall islet size distribution. Furthermore, islets exhibit a striking plasticity in cellular composition and architecture among different species and also within the same species under various pathophysiological conditions. In the present study, we describe novel approaches for the analysis of biological image data in order to facilitate the automation of analytic processes, which allow for the analysis of large and heterogeneous data collections in the study of such dynamic biological processes and complex structures. Such studies have been hampered due to technical difficulties of unbiased sampling and generating large-scale data sets to precisely capture the complexity of biological processes of islet biology. Here we show methods to collect unbiased "representative" data within the limited availability of samples (or to minimize the sample collection) and the standard experimental settings, and to precisely analyze the complex three-dimensional structure of the islet. Computer-assisted automation allows for the collection and analysis of large-scale data sets and also assures unbiased interpretation of the data. Furthermore, the precise quantification of islet size distribution and spatial coordinates (i.e. X, Y, Z-positions) not only leads to an accurate visualization of pancreatic islet structure and composition, but also allows us to identify patterns during development and adaptation to altering conditions through mathematical modeling. The methods developed in this study are applicable to studies of many other systems and organisms as well.

Novel computer-assisted methods of large-scale procurement and analysis of immunohistochemically stained pancreatic specimens are described: (1) Virtual Slice capture of the entire section; (2) Mass analysis of large-scale data; (3) Reconstruction of 2D Virtual Slices; (4) 3D islet mapping; and (5) Mathematical analysis.

Asistida por ordenador a gran escala de visualización y cuantificación de los islotes pancreáticos, distribución de tamaño y arquitectura

The pancreatic islet is a unique micro-organ composed of several hormone secreting endocrine cells such as beta-cells (insulin), alpha-cells (glucagon), ...

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 ...

Pancreatic Islet Embedding for Paraffin Sections

Experiments using isolated pancreatic islets are important for diabetes research, but islets are expensive and of limited abundance. Islets contain a mixed cell population in a structured architecture that impacts function, and human islets are widely variable in cell type composition. Current frequently used methods to study cultured islets include molecular studies performed on whole islets, lumping disparate islet cell types together, or microscopy or molecular studies on dispersed islet cells, disrupting islet architecture. For in vivo islet studies, paraffin-embedded pancreas sectioning is a powerful technique to assess cell-specific outcomes in the native pancreatic environment. Studying post-culture islets by paraffin sectioning would offer several advantages: detection of multiple outcomes on the same islets (potentially even the exact-same islets, using serial sections), cell-type-specific measurements, and maintaining native islet cell-cell and cell-substratum interactions both during experimental exposure and for analysis. However, existing techniques for embedding isolated islets post-culture are inefficient, time consuming, prone to loss of material, and generally produce sections with inadequate islet numbers to be useful for quantifying outcomes. Clinical pathology laboratory cell block preparation facilities are inaccessible and impractical for basic research laboratories. We have developed an improved, simplified bench-top method that generates sections with robust yield and distribution of islets. Fixed islets are resuspended in warm histological agarose gel and pipetted into a flat disc on a standard glass slide, such that the islets are distributed in a plane. After standard dehydration and embedding, multiple (10+) 4 - 5 &#181;m sections can be cut from the same islet block. Using this method, histological&#160;and immunofluorescent analyses can be performed on mouse, rat, and human islets. This is an effective, inexpensive, time-saving approach to assess cell-type-specific, intact-architecture outcomes from cultured islets.

Ex vivo pancreatic islet studies are important for diabetes research. Existing techniques to study cultured islets in their native 3-dimensional architecture are time consuming, inefficient, and infrequently used. This work describes a new, simple, and efficient method for generating high-quality paraffin sections of whole cultured islets.

Islote pancreático inclusión de secciones de la parafina

Experiments using isolated pancreatic islets are important for diabetes research, but islets are expensive and of limited abundance. Islets contain a ...

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 ...

Diferenciación de células madre pluripotentes humanas en células β pancreáticas

Optimized Protocol for Generating Functional Pancreatic Insulin-secreting Cells from Human Pluripotent Stem Cells

Human pluripotent stem cells (hPSCs) can differentiate into any kind of cell, making them an excellent alternative source of human pancreatic &#946;-cells. hPSCs can either be embryonic stem cells (hESCs) derived from the blastocyst or induced pluripotent cells (hiPSCs) generated directly from somatic cells using a reprogramming process. Here a video-based protocol is presented to outline the optimal culture and passage conditions for hPSCs, prior to their differentiation and subsequent generation of insulin-producing pancreatic cells. This methodology follows the six-stage process for &#946;-cell directed differentiation, wherein hPSCs differentiate into definitive endoderm (DE), primitive gut tube, posterior foregut fate, pancreatic progenitors, pancreatic endocrine progenitors, and ultimately pancreatic &#946;-cells. It is noteworthy that this differentiation methodology takes a period of 27 days to generate human pancreatic &#946;-cells. The potential of insulin secretion was evaluated through two experiments, which included immunostaining and glucose-stimulated insulin secretion.

Autor destacado: Avances y desafíos en la diferenciación de células β a partir de células madre pluripotentes

This article presents a protocol for directed differentiation and functional analysis of &#946;-cell like cells. We describe optimal culture conditions and passages for human pluripotent stem cells before generating insulin-producing pancreatic cells. The six-stage differentiation progresses from definitive endoderm formation to functional &#946;-cell like cells secreting insulin in response to glucose.

Methods Article

Aislamiento humanos islote pancreático: Parte I: La digestión y la acumulación de tejido pancreático