Este trabajo fue apoyado por OTKA (Fondo de Investigación Científica de Hungría) D45933, T049621, TET (húngaro Fundación de Ciencia y Tecnología) A4/04, Arg-17/2006 y el SIN, Bolyai, Becas y Öveges TÁMOP 4.2.2-08 / 1 / KMR-2008-0004 y 4.2.1 / B 09/1/KMR-2010-0001. OTKA 83803. Nos gustaría dar las gracias a William Gesztes para proporcionar la voz en off.

1. Preparación de las células H9c2 cardiomyoblast H9c2 cardiomyoblasts rata se obtuvieron de ATCC (Wesel, Alemania) y ampliado en el alto nivel de glucosa (4,5 g / L) DMEM con 10% de suero fetal bovino, 4 mM L-glutamina, 100 U / ml de penicilina y estreptomicina 100 mg / ml. La línea de mioblastos H9c2 células se deriva de corazón de rata embrionaria, que se utiliza como un modelo in vitro para ambos músculo esquelético y cardíaco 8,9. Prepare 12 y placa de células H9c2: <ol><li> Quitar medio de cultivo de una placa de Petri de células H9c2. </li><li> Lavar las células dos veces con 5 ml de PBS y digerir con 2-3 ml de 0,05% de tripsina / EDTA. </li><li> Colocar placa de Petri durante 5 minutos en la incubadora a 37 ° C. </li><li> Inhibir la tripsina con 10 ml de medio de cultivo DMEM. </li><li> Centrifugar las células a 1200 rpm durante 8 minutos. </li><li> Después de la eliminación de las células sobrenadante, resuspender en 1 ml de medio de cultivo DMEM y las células cuentan con hemocitómetro utilizando tinción con azul tripán.</li><li> Semillas de 30.000 H9c2 células en 2 ml de DMEM por pocillo en una placa de 12 también. </li><li> Colocar la placa en los 37 ° C incubadora de CO 2 durante 24 horas. </li></ol> 2. Isquemia simulada / reperfusión Isquemia / reperfusión fue simulada in vitro mediante la realización de la privación de oxígeno la glucosa (OGD) en cultivos de células H9c2. Este procedimiento se realizó en la platina del microscopio confocal Zeiss con el sistema de incubación de células PECON (Erbach, Alemania), que permite la observación de las células durante la OGD. <ol><li> Quitar medio por aspiración de 12 pocillos de células H9c2. </li><li> Lavar las células dos veces con PBS. </li><li> Añadir 3 ml de medio de glucosa libre por pozo. </li><li> Colocar la placa en el sistema de incubación de células. </li><li> Inicio de gas nitrógeno para purgar el oxígeno fuera del sistema de incubación. </li><li> Espere hasta que el nivel de oxígeno llega a 0,5% luego iniciar el temporizador. 0,5% de oxígeno significa aproximadamente 3 mmHg la tensión parcial. Células sujetas a una50 minutos de isquemia simulada. </li><li> Al final de la isquemia simulada, eliminar el medio de glucosa libre de las células. </li><li> Pipetear 2 ml de medio de cultivo normal de los pozos. </li><li> Coloque la placa de 12 pocillos durante 30 minutos en los 37 ° C incubadora de CO 2, lo que es el &quot;período de reperfusión&quot;. </li></ol> 3. Preparación de las células madre mesenquimales de rescate La médula ósea de origen humano se ha tenido en frascos T75 y se diluye con medio modificado de Dulbecco Eagle (DMEM) medio de cultivo con 10% de suero fetal bovino (FCS), 100 de penicilina U / ml y 100 estreptomicina mg / ml, 4 mM L-glutamina y 1 g / l de glucosa. Los matraces se incubaron a 37 º C en una atmósfera completamente humidificada de 5% de CO 2 durante 3 días. Después del período de incubación de la BMSCs adherida a la superficie de los frascos y los restantes componentes de la médula ósea se han eliminado mediante el lavado con PBS. El BMSCs utilizados fueron entre 1 y 5 pasajes en los experimentos. La identidadtidad de las células fue confirmado por la presencia del linaje de los marcadores específicos de la superficie celular por citometría de flujo. Hematopoyéticas linaje específico de los marcadores de superficie (CD34, CD45) y marcadores mesenquimales de la superficie (CD73, CD90, CD105 y CD166) fueron investigados. Durante la isquemia simulada, preparar las células madre mesenquimales de rescate para el trasplante. <ol><li> Diluir el colorante fluorescente Vybrant hizo en relación 1:200 en medio de cultivo DMEM. </li><li> Aspirar medio de las células de rescate y añadir 300 l DMEM con Vybrant DID. </li><li> Colocar placa de Petri durante 30 minutos en los 37 ° C incubadora de CO 2. </li><li> Quitar medio de cultivo de una placa de Petri de células madre mesenquimales. </li><li> Lavar las células dos veces con 5 ml de PBS y digerir con 2-3 ml de 0,05% de tripsina / EDTA. </li><li> Colocar placa de Petri durante 5 minutos en la incubadora a 37 ° C. </li><li> Inhibir la tripsina con 10 ml de medio de cultivo DMEM. </li><li> Centrifugar las células a 1200 rpm durante 8 minutos. </li><li> Después de retirar la supecélulas rnatant, resuspender en 1 ml de medio de cultivo DMEM y las células cuentan con hemocitómetro utilizando tinción con azul tripán. </li><li> Después de 30 minutos al final de la reperfusión añadir 20.000 células madre mesenquimales por tanto a la post-isquémica cardiaca H9c2 mioblastos. </li><li> Lugar de co-cultivo de células en los 37 ° C incubadora de CO 2 durante 24 horas. </li></ol> 4. Análisis con microscopía confocal Después de la simulación de la isquemia / reperfusión, las células se incubaron en medio de cultivo normal durante 24 horas. <ol><li> Después de 24 horas, lave las células dos veces con PBS. </li><li> Tinción de las células en 500 l en vivo / muerto solución colorante durante 30 minutos (5 nM calceína y 400 Nm de etidio-homodímero-2 en PBS) (5x10 4 células / ml). </li></ol> La evaluación de las imágenes de confocal de las células vivas y muertas, seleccionados por la morfología y la fluorescencia se puede realizar con el software ImageJ (National Institutes of Health, EE.UU.). En el caso de co-las culturas, las MSC se pueden distinguir de las células H9c2 debido a su etiquetado Vybrant celular DID. La proporción de células muertas pueden ser evaluados en cuatro campos de vista independiente (objetivo 10x) para cada cultura a ciegas 10. H9c2 cardiomyoblasts cultivadas en cubreobjetos de 42 mm de cristal también puede ser investigado con el microscopio de vídeo lapso de tiempo durante y después de la lesión por isquemia / reperfusión mediante el sistema de incubación de células del microscopio confocal. Célula a célula de las interacciones, como la fusión celular y la formación de los nanotubos intercelulares, se pueden estudiar a través del tiempo. 5. Análisis por citometría de flujo Después de la simulación de la isquemia / reperfusión, las células se incubaron en medio de cultivo normal durante 24 horas. <ol><li> Después de 24 horas, la cosecha de los medios de cultivo. Es muy importante para recoger el medio de cultivo también porque algunas células muertas podría haber desprendido de la superficie de la placa de cultivo durante la incubación de 24 horasción. </li><li> Lavar las células dos veces con PBS y se digieren con 0,05% de tripsina-EDTA. </li><li> Inhibir la tripsina con medio de cultivo DMEM. </li><li> Centrifugar las células y el medio de cultivo cosechado a 1200 rpm (aproximadamente 150-200g) durante 8 minutos. </li><li> Eliminar el sobrenadante. </li><li> Suspender las células en 500 l en vivo / muerto solución colorante durante 30 minutos (5 nM calceína y 400 Nm de etidio-homodímero-2 en PBS) (5x10 4 células / ml). </li><li> La transferencia de las células de los tubos de flujo de citometría. </li><li> Inicie el software Pro CellQuest. </li><li> Para configurar el citómetro de flujo para la medición, el control de preparar muestras de células vivas y muertas. <ol class="lalpha"><li> Placa H9c2 células a una densidad de 3x10 4 en placas de 12 pocillos como se describe en el punto 1. </li><li> Prepare vivir controles de células con tripsinización solo como se describe en el punto 1. </li><li> Preparar los controles de las células muertas por el tratamiento con 10 mM H 2 O 2 durante 1 hora. </li><li> Después de tripsinización, resuspend vivir y los controles de las células muertas en la solución de 500 l tinte vivo / muerto (5 nM calceína-AM y 400 Nm de etidio-homodímero-2 en PBS). </li></ol></li><li> La configuración del instrumento se debe ajustar para que las células vivientes son calceína positivo y negativo homodímero de etidio, mientras que las células muertas son calceína negativos y positivos homodímero de etidio. </li><li> El porcentaje de estas poblaciones puede expresarse como barras en un gráfico y el análisis estadístico se pueden realizar en estos valores. </li><li> Medir los diferentes grupos experimentales. </li></ol> 6. Los resultados representativos: Nuestros resultados mostraron que añadir las células madre mesenquimales podrían mejorar la supervivencia de las células cardíacas postisquémica. Imágenes de microscopía confocal reveló directa de célula a célula interacciones, como la conexión a la membrana parcial o nanotubos intercelulares, lo que probablemente juegan un papel importante en la protección observada 10. Estos nanotubos abarcan distancias de varias células diameters, y sus diámetros son entre 200 y 500 nm (flechas blancas). <img src="/files/ftp_upload/3575/3575fig1.jpg" alt="Figura 1" /> Figura 1. La formación de nanotubos de entre las células. Formación de nanotubos (flecha blanca) se observó entre Vybrant cardiomyoblasts DiO etiquetados y marcados Vybrant SABÍA células madre mesenquimales. Análisis de citometría de flujo mostró las poblaciones de sobrevivir y cardiomyoblasts necrótico y las células madre mesenquimales. Curiosamente, también se observó una población cardiomyoblast tercero, &#39;herido&#39; de células que contiene calceína, pero también contiene el indicador de las células muertas, homodímero de etidio (Figura 2). <img src="/files/ftp_upload/3575/3575fig2.jpg" alt="Figura 2" /> Figura 2. Representante punto de parcelas de los diferentes poblaciones de células después de la isquemia simulada. La evaluación de varios experimentos showed que la adición de células madre mesenquimales a postisquémica cardiomyoblast H9c2 aumentó significativamente el porcentaje de células vivas en comparación con los mioblastos cardiacos cultivadas solo después de la isquemia (Figura 3). <img src="/files/ftp_upload/3575/3575fig3.jpg" alt="Figura 3" /> Figura 3. . Efecto del tratamiento con células madre en cardiomyoblasts postisquémica porcentaje de las células vivas se redujo significativamente después de la isquemia simulada en comparación con el control (control vs modelo IR: 90,36 ± 2,60 vs 10,52 ± 0,48, *** p&gt; 0,001), que aumentó después de la adición de células madre mesenquimales (IR modelo vs IR + BMSC: 10,52 ± 0,48 vs 25,21 ± 2,13, *** p&gt; 0,001). Los datos representan la media ± SEM. El análisis estadístico de los datos se realizó mediante un análisis de varianza con el mensaje comparación múltiple de Tukey hoc test.

<ol>
	<li>Dimmeler, S., Burchfield, J., Zeiher, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell-Based+Therapy+of+Myocardial+Infarction.">Cell-Based Therapy of Myocardial Infarction.</a> Arterioscler Thromb Vasc Biol. 28, (2008).</li><li>Kim, S. U., de Vellis, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stem+cell-based+cell+therapy+in+neurological+diseases:+A+review.">Stem cell-based cell therapy in neurological diseases: A review.</a> Journal of Neuroscience Research. 87, 2183-21 (2009).</li><li>Lee, K., Chan, C. K., Patil, N., Goodman, S. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+therapy+for+bone+regeneration-Bench+to+bedside.">Cell therapy for bone regeneration-Bench to bedside.</a> Journal of Biomedical Materials Research Part B: Applied Biomaterials. 89, 252-25 (2009).</li><li>Gaipa, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=GMP-based+CD133++cells+isolation+maintains+progenitor+angiogenic+properties+and+enhances+standardization+in+cardiovascular+cell+therapy.">GMP-based CD133+ cells isolation maintains progenitor angiogenic properties and enhances standardization in cardiovascular cell therapy.</a> Journal of Cellular and Molecular Medicine. 14, 1619-1619 (2010).</li><li>Trounson, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+perspectives+in+human+stem+cell+therapeutic+research.">New perspectives in human stem cell therapeutic research.</a> BMC medicine. 7, 29-29 (2009).</li><li>Mazhari, R., Hare, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanisms+of+action+of+mesenchymal+stem+cells+in+cardiac+repair:+potential+influences+on+the+cardiac+stem+cell+niche.">Mechanisms of action of mesenchymal stem cells in cardiac repair: potential influences on the cardiac stem cell niche.</a> Nat Clin Pract Cardiovasc Med. 4, S21-S21 (2007).</li><li>Kimes, B. W., Brandt, B. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Properties+of+a+clonal+muscle+cell+line+from+rat+heart.">Properties of a clonal muscle cell line from rat heart.</a> Experimental Cell Research. 98, 367-367 (1976).</li><li>Sardao, V. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vital+imaging+of+H9c2+myoblasts+exposed+to+tert-butylhydroperoxide--characterization+of+morphological+features+of+cell+death.">Vital imaging of H9c2 myoblasts exposed to tert-butylhydroperoxide--characterization of morphological features of cell death.</a> BMC Cell Biol. 8, 11-11 (2007).</li><li>Hescheler, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Morphological,+biochemical,+and+electrophysiological+characterization+of+a+clonal+cell+(H9c2)+line+from+rat+heart.">Morphological, biochemical, and electrophysiological characterization of a clonal cell (H9c2) line from rat heart.</a> Circulation research. 69, 1476-1476 (1991).</li><li>Cselenyak, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mesenchymal+stem+cells+rescue+cardiomyoblasts+from+cell+death+in+an+in+vitro+ischemia+model+via+direct+cell-to-cell+connections.">Mesenchymal stem cells rescue cardiomyoblasts from cell death in an in vitro ischemia model via direct cell-to-cell connections.</a> BMC Cell Biol. 11, 29-29 (2010).</li><li>Sauvant, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Implementation+of+an+in+vitro+model+system+for+investigation+of+reperfusion+damage+after+renal+ischemia.">Implementation of an in vitro model system for investigation of reperfusion damage after renal ischemia.</a> Cell Physiol Biochem. 24, 567-567 (2009).</li><li>Namas, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hypoxia-Induced+Overexpression+of+BNIP3+is+Not+Dependent+on+Hypoxia-Inducible+Factor+1alpha+in+Mouse+Hepatocytes.">Hypoxia-Induced Overexpression of BNIP3 is Not Dependent on Hypoxia-Inducible Factor 1alpha in Mouse Hepatocytes.</a> Shock. 36, 196-196 (2011).</li><li>Cao, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hypoxia/Reoxygenation+Up-Regulated+the+Expression+of+Death+Receptor+5+and+Enhanced+Apoptosis+in+Human+Hepatocyte+Line.">Hypoxia/Reoxygenation Up-Regulated the Expression of Death Receptor 5 and Enhanced Apoptosis in Human Hepatocyte Line.</a> Transplantation Proceedings. 38, 2207-2207 (2006).</li><li>Meloni, B. P., Meade, A. J., Kitikomolsuk, D., Knuckey, N. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterisation+of+neuronal+cell+death+in+acute+and+delayed+in+vitro+ischemia+(oxygen-glucose+deprivation)+models.">Characterisation of neuronal cell death in acute and delayed in vitro ischemia (oxygen-glucose deprivation) models.</a> Journal of Neuroscience Methods. 195, 67-67 (2011).</li><li>Mimeault, M., Hauke, R., Batra, S. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stem+cells:+a+revolution+in+therapeutics--recent+advances+in+stem+cell+biology+and+their+therapeutic+applications+in+regenerative+medicine+and+cancer+therapies.">Stem cells: a revolution in therapeutics--recent advances in stem cell biology and their therapeutic applications in regenerative medicine and cancer therapies.</a> Clinical Pharmacology &#38; Therapeutics. 82, 252-252 (2007).</li><li>Angoulvant, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mesenchymal+stem+cell+conditioned+media+attenuates+in+vitro+and+ex+vivo+myocardial+reperfusion+injury.">Mesenchymal stem cell conditioned media attenuates in vitro and ex vivo myocardial reperfusion injury.</a> J Heart Lung Transplant. 30, 95-95 (2010).</li><li>Lim, Y. J., Zheng, S., Zuo, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Morphine+Preconditions+Purkinje+Cells+against+Cell+Death+under+In+Vitro+Simulated+Ischemia/Reperfusion+Conditions.">Morphine Preconditions Purkinje Cells against Cell Death under In Vitro Simulated Ischemia/Reperfusion Conditions.</a> Anesthesiology. 100, 562-562 (2004).</li><li>Guo, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Estrogen-receptor-mediated+protection+of+cerebral+endothelial+cell+viability+and+mitochondrial+function+after+ischemic+insult+in+vitro.">Estrogen-receptor-mediated protection of cerebral endothelial cell viability and mitochondrial function after ischemic insult in vitro.</a> J Cereb Blood Flow Metab. 30, 545-545 (2010).</li></ol>

No hay conflictos de interés declarado.

El protocolo se ha demostrado un enfoque in vitro a la cuestión mucho más compleja de la terapia celular en infarto de miocardio, con todas las ventajas y desventajas de este modelo. Obviamente, no puede reflejar el complejo (inmunológicos, por ejemplo) los acontecimientos que ocurren durante y después del infarto de miocardio, pero puede centrarse en los efectos directos de las células añadido en las células postisquémica. Los efectos de la isquemia simulada en H9c2 cardiomyoblasts dependen en gran medida el mo...

<table border="1"><tbody><tr><td> Nombre del reactivo </td><td> Empresa </td><td> Número de catálogo </td><td> Comentarios </td></tr><tr><td> calceína-AM </td><td> Las sondas moleculares </td><td> L3224, C3099 </td><td> <a href="http://www.invitrogen.com">http://www.invitrogen.com</a> </td></tr><tr><td> homodímero de etidio-2 </td><td> Las sondas moleculares </td><td> L3224, E3599 </td><td> <a href="http://www.invitrogen.com">http://www.invitrogen.com</a> </td></tr><tr><td> ¿SABÍA Vybrant </td><td> Las sondas moleculares </td><td> V22887 </td><td> <a href="http://www.invitrogen.com">http://www.invitrogen.com</a> </td></tr></tbody></table> Tabla 1. Reactivos. <table border="1"><tbody><tr><td> Nombre del equipo </td><td> Empresa </td><td> Comentarios (opcional) </td></tr><tr><td> Celular PECON incubación sistema de microscopios Zeiss </td><td> PECON GmbH </td><td> <a href="http://www.pecon.biz/">www.pecon.biz/</a> </td></tr></tbody></table> Tabla 2. Equipo.

stem cell transplantation in an in vitro simulated ischemia/reperfusion model

El trasplante de células madre protocolos están encontrando su camino en la práctica clínica 1,2,3. Obtener mejores resultados, por lo que los protocolos más robustos, y la búsqueda de nuevas fuentes de células implantables son el foco de las investigaciones recientes 4,5. La investigación de la eficacia de las terapias con células no es una tarea fácil y se necesitan nuevas herramientas para investigar los mecanismos implicados en el proceso de tratamiento 6. Hemos diseñado un protocolo experimental de isquemia / reperfusión con el fin de permitir la observación de las conexiones celulares y los mecanismos subcelulares incluso durante la lesión por isquemia / reperfusión y después del trasplante de células madre y para evaluar la eficacia de la terapia celular. H9c2 células cardiomyoblast se colocaron en placas de cultivo celular 7,8. La isquemia se simuló con 150 minutos en un medio de glucosa libre con el nivel de oxígeno por debajo del 0,5%. Entonces, los medios de comunicación normales y los niveles de oxígeno se volvieron a introducir para simular la reperfusión. Después de la falta de oxígeno la glucosa,las células dañadas fueron tratados con trasplante de médula ósea humana etiquetados derivados de células madre mesenquimales mediante su inclusión en la cultura. Las células madre mesenquimales son las preferidas en los estudios clínicos porque son de fácil acceso con la cirugía mínimamente invasiva, ampliable fácilmente y autólogo. Después de 24 horas de co-cultivo, las células fueron teñidas con calceína y homodímero de etidio-para diferenciar entre células vivas y muertas. Esta configuración nos permite investigar las conexiones intercelulares mediante microscopía confocal de fluorescencia y para cuantificar la tasa de supervivencia de las células postisquémica por citometría de flujo. La microscopía confocal mostraron las interacciones de las dos poblaciones de células, como la fusión celular y la formación de los nanotubos intercelulares. Análisis de citometría de flujo reveló tres grupos de células dañadas que se pueden representar en un gráfico y se analizaron estadísticamente. Estas poblaciones pueden ser investigados por separado y se pueden sacar conclusiones sobre estos datos sobre la eficacia de la simulaciónenfoque terapéutico.

Watch this Scientific Journal Video about Stem Cell Transplantation in an in vitro Simulated Ischemia/Reperfusion Model at JoVE.com

Stem Cell Transplantation in an in vitro Simulated Ischemia/Reperfusion Model

Demostramos cómo configurar un<em&gt; In vitro</em&gt; Isquemia / reperfusión modelo y la forma de evaluar el efecto de la terapia con células madre en células cardíacas postisquémica.

Trasplante de células madre en un In vitro Simulación de isquemia / reperfusión modelo

Stem cell transplantation protocols are finding their way into clinical practice1,2,3. Getting better results, making the protocols more robust, and ...

stem-cell-transplantation-an-vitro-simulated-ischemiareperfusion

Research

JoVE Journal

Medicine

Stem Cell Transplantation in an in vitro Simulated Ischemia/Reperfusion Model

14.0K vistas.  Semmelweis University. Demostramos cómo configurar un In vitro Isquemia / reperfusión modelo y la forma de evaluar el efecto de la terapia con células madre en células cardíacas postisquémica.

Video: Stem Cell Transplantation in an in vitro Simulated Ischemia/Reperfusion Model

A Mouse Model of in Utero Transplantation

The transplantation of stem cells and viruses in utero has tremendous potential for treating congenital disorders in the human fetus. For example, in utero transplantation (IUT) of hematopoietic stem cells has been used to successfully treat patients with severe combined immunodeficiency.1,2 In several other conditions, however, IUT has been attempted without success.3 Given these mixed results, the availability of an efficient non-human model to study the biological sequelae of stem cell transplantation and gene therapy is critical to advance this field. We and others have used the mouse model of IUT to study factors affecting successful engraftment of in utero transplanted hematopoietic stem cells in both wild-type mice4-7 and those with genetic diseases.8,9 The fetal environment also offers considerable advantages for the success of in utero gene therapy. For example, the delivery of adenoviral10, adeno-associated viral10, retroviral11, and lentiviral vectors12,13 into the fetus has resulted in the transduction of multiple organs distant from the site of injection with long-term gene expression. in utero gene therapy may therefore be considered as a possible treatment strategy for single gene disorders such as muscular dystrophy or cystic fibrosis. Another potential advantage of IUT is the ability to induce immune tolerance to a specific antigen. As seen in mice with hemophilia, the introduction of Factor IX early in development results in tolerance to this protein.14 
In addition to its use in investigating potential human therapies, the mouse model of IUT can be a powerful tool to study basic questions in developmental and stem cell biology. For example, one can deliver various small molecules to induce or inhibit specific gene expression at defined gestational stages and manipulate developmental pathways. The impact of these alterations can be assessed at various timepoints after the initial transplantation. Furthermore, one can transplant pluripotent or lineage specific progenitor cells into the fetal environment to study stem cell differentiation in a non-irradiated and unperturbed host environment.
The mouse model of IUT has already provided numerous insights within the fields of immunology, and developmental and stem cell biology. In this video-based protocol, we describe a step-by-step approach to performing IUT in mouse fetuses and outline the critical steps and potential pitfalls of this technique.

A Mouse Model of in Utero Transplantation

The mouse model of in utero transplantation is a versatile tool that can be used to study the potential clinical applications of stem cell transplantation and gene therapy in the fetus. In this protocol, we present a general approach to performing this technique

Un modelo de ratón En el útero Trasplante

The transplantation of stem cells and viruses in utero has tremendous potential for treating congenital disorders in the human fetus.  For example, in ...

Investigación

Medicina

Using Quantitative Real-time PCR to Determine Donor Cell Engraftment in a Competitive Murine Bone Marrow Transplantation Model

Murine bone marrow transplantation models provide an important tool in measuring hematopoietic stem cell (HSC) functions and determining genes/molecules that regulate HSCs. In these transplant model systems, the function of HSCs is determined by the ability of these cells to engraft and reconstitute lethally irradiated recipient mice. Commonly, the donor cell contribution/engraftment is measured by antibodies to donor- specific cell surface proteins using flow cytometry. However, this method heavily depends on the specificity and the ability of the cell surface marker to differentiate donor-derived cells from recipient-originated cells, which may not be available for all mouse strains. Considering the various backgrounds of genetically modified mouse strains in the market, this cell surface/ flow cytometry-based method has significant limitations especially in mouse strains that lack well-defined surface markers to separate donor cells from congenic recipient cells. Here, we reported a PCR-based technique to determine donor cell engraftment/contribution in transplant recipient mice. We transplanted male donor bone marrow HSCs to lethally irradiated congenic female mice. Peripheral blood samples were collected at different time points post transplantation. Bone marrow samples were obtained at the end of the experiments. Genomic DNA was isolated and the Y chromosome specific gene, Zfy1, was amplified using quantitative Real time PCR. The engraftment of male donor-derived cells in the female recipient mice was calculated against standard curve with known percentage of male vs. female DNAs. Bcl2 was used as a reference gene to normalize the total DNA amount. Our data suggested that this approach reliably determines donor cell engraftment and provides a useful, yet simple method in measuring hematopoietic cell reconstitution in murine bone marrow transplantation models. Our method can be routinely performed in most laboratories because no costly equipment such as flow cytometry is required.

Determining donor cell engraftment presents a challenge in mouse bone marrow transplant models that lack well-defined phenotypical markers. We described a methodology to quantify male donor cell engraftment in female transplant recipient mice. This method can be used in all mouse strains for the study of HSC functions.

Usando cuantitativa en tiempo real PCR para determinar quimerismo de células donantes en un modelo competitivo Trasplante de médula ósea murina

Murine bone marrow transplantation models provide an important tool in measuring hematopoietic stem cell (HSC) functions and determining genes/molecules ...

Ischemia-reperfusion Model of Acute Kidney Injury and Post Injury Fibrosis in Mice

Ischemia-reperfusion induced acute kidney injury (IR-AKI) is widely used as a model of AKI in mice, but results are often quite variable with high, often unreported mortality rates that may confound analyses. Bilateral renal pedicle clamping is commonly used to induce IR-AKI, but differences between effective clamp pressures and/or renal responses to ischemia between kidneys often lead to more variable results. In addition, shorter clamp times are known to induce more variable tubular injury, and while mice undergoing bilateral injury with longer clamp times develop more consistent tubular injury, they often die within the first 3 days after injury due to severe renal insufficiency. To improve post-injury survival and obtain more consistent and predictable results, we have developed two models of unilateral ischemia-reperfusion injury followed by contralateral nephrectomy. Both surgeries are performed using a dorsal approach, reducing surgical stress resulting from ventral laparotomy, commonly used for mouse IR-AKI surgeries. For induction of moderate injury BALB/c mice undergo unilateral clamping of the renal pedicle for 26 min and also undergo simultaneous contralateral nephrectomy. Using this approach, 50-60% of mice develop moderate AKI 24 hr after injury but 90-100% of mice survive. To induce more severe AKI, BALB/c mice undergo renal pedicle clamping for 30 min followed by contralateral nephrectomy 8 days after injury. This allows functional assessment of renal recovery after injury with 90-100% survival. Early post-injury tubular damage as well as post injury fibrosis are highly consistent using this model.

We describe models of moderate and severe ischemia-reperfusion-induced kidney injury in which the mice undergo unilateral renal pedicle clamping followed by simultaneous or delayed contralateral nephrectomy, respectively. These models consistently give rise to renal dysfunction and post-injury fibrosis, but injury severity and survival are dependent on mouse background, age and surgical equipment.

La isquemia-reperfusión modelo de lesión renal aguda y post lesión fibrosis en ratones

Ischemia-reperfusion induced acute kidney injury (IR-AKI) is widely used as a model of AKI in mice, but results are often quite variable with high, often ...

Neural Stem Cell Transplantation in Experimental Contusive Model of Spinal Cord Injury

Spinal cord injury is a devastating clinical condition, characterized by a complex of neurological dysfunctions. Animal models of spinal cord injury can be used both to investigate the biological responses to injury and to test potential therapies. Contusion or compression injury delivered to the surgically exposed spinal cord are the most widely used models of the pathology. In this report the experimental contusion is performed by using the Infinite Horizon (IH) Impactor device, which allows the creation of a reproducible injury animal model through definition of specific injury parameters. Stem cell transplantation is commonly considered a potentially useful strategy for curing this debilitating condition. Numerous studies have evaluated the effects of transplanting a variety of stem cells. Here we demonstrate an adapted method for spinal cord injury followed by tail vein injection of cells in CD1 mice. In short, we provide procedures for: i) cell labeling with a vital tracer, ii) pre-operative care of mice, iii) execution of a contusive spinal cord injury, and iv) intravenous administration of post mortem neural precursors. This contusion model can be utilized to evaluate the efficacy and safety of stem cell transplantation in a regenerative medicine approach.

Spinal cord injury is a traumatic condition that causes severe morbidity and high mortality. In this work we describe in detail a contusion model of spinal cord injury in mice followed by a transplantation of neural stem cells.

Neural Trasplante de células madre en Experimental contuso Modelo de Lesión de la Médula Espinal

Spinal cord injury is a devastating clinical condition, characterized by a complex of neurological dysfunctions. Animal models of spinal cord injury can ...

Oxygen-Glucose Deprivation and Reoxygenation as an In Vitro Ischemia-Reperfusion Injury Model for Studying Blood-Brain Barrier Dysfunction

Ischemia-Reperfusion (IR) injury is known to contribute significantly to the morbidity and mortality associated with ischemic strokes. Ischemic cerebrovascular accidents account for 80% of all strokes. A common cause of IR injury is the rapid inflow of fluids following an acute/chronic occlusion of blood, nutrients, oxygen to the tissue triggering the formation of free radicals.
Ischemic stroke is followed by blood-brain barrier (BBB) dysfunction and vasogenic brain edema. Structurally, tight junctions (TJs) between the endothelial cells play an important role in maintaining the integrity of the blood-brain barrier (BBB). IR injury is an early secondary injury leading to a non-specific, inflammatory response. Oxidative and metabolic stress following inflammation triggers secondary brain damage including BBB permeability and disruption of tight junction (TJ) integrity.
Our protocol presents an in vitro example of oxygen-glucose deprivation and reoxygenation (OGD-R) on rat brain endothelial cell TJ integrity and stress fiber formation. Currently, several experimental in vivo models are used to study the effects of IR injury; however they have several limitations, such as the technical challenges in performing surgeries, gene dependent molecular influences and difficulty in studying mechanistic relationships. However, in vitro models may aid in overcoming many of those limitations. The presented protocol can be used to study the various molecular mechanisms and mechanistic relationships to provide potential therapeutic strategies. However, the results of in vitro studies may differ from standard in vivo studies and should be interpreted with caution.

Oxygen-Glucose Deprivation and Reoxygenation as an In Vitro Ischemia-Reperfusion Injury Model for Studying Blood-Brain Barrier Dysfunction

Ischemia-Reperfusion (IR) injury is associated with a high rate of morbidity and mortality. The goal of the in vitro model of oxygen-glucose deprivation and reoxygenation (OGD-R) described here is to assess the effects of ischemia reperfusion injury on a variety of cells, particularly in blood-brain barrier (BBB) endothelial cells.

Oxígeno-Glucosa Privación y Reoxigenación como<em&gt; In Vitro</em&gt; La isquemia-reperfusión modelo para el estudio de la disfunción barrera hematoencefálica

Ischemia-Reperfusion (IR) injury is known to contribute significantly to the morbidity and mortality associated with ischemic strokes. Ischemic ...

Studying Pancreatic Cancer Stem Cell Characteristics for Developing New Treatment Strategies

Pancreatic ductal adenocarcinoma (PDAC) contains a subset of exclusively tumorigenic cancer stem cells (CSCs) which have been shown to drive tumor initiation, metastasis and resistance to radio- and chemotherapy. Here we describe a specific methodology for culturing primary human pancreatic CSCs as tumor spheres in anchorage-independent conditions. Cells are grown in serum-free, non-adherent conditions in order to enrich for CSCs while their more differentiated progenies do not survive and proliferate during the initial phase following seeding of single cells. This assay can be used to estimate the percentage of CSCs present in a population of tumor cells. Both size (which can range from 35 to 250 micrometers) and number of tumor spheres formed represents CSC activity harbored in either bulk populations of cultured cancer cells or freshly harvested and digested tumors 1,2. Using this assay, we recently found that metformin selectively ablates pancreatic CSCs; a finding that was subsequently further corroborated by demonstrating diminished expression of pluripotency-associated genes/surface markers and reduced in vivo tumorigenicity of metformin-treated cells. As the final step for preclinical development we treated mice bearing established tumors with metformin and found significantly prolonged survival. Clinical studies testing the use of metformin in patients with PDAC are currently underway (e.g., NCT01210911, NCT01167738, and NCT01488552). Mechanistically, we found that metformin induces a fatal energy crisis in CSCs by enhancing reactive oxygen species (ROS) production and reducing mitochondrial transmembrane potential. In contrast, non-CSCs were not eliminated by metformin treatment, but rather underwent reversible cell cycle arrest. Therefore, our study serves as a successful example for the potential of in vitro sphere formation as a screening tool to identify compounds that potentially target CSCs, but this technique will require further in vitro and in vivo validation to eliminate false discoveries.

Pancreatic cancer stem cells (CSCs) can be expanded in vitro using the anchorage-independent sphere culture technique, which represents a powerful tool to study CSC biology and can serve as the first step to develop novel CSC-targeting therapies. Here the methodology for expanding, analyzing and targeting of pancreatic CSCs is provided.

El estudio de cáncer de páncreas Tallo Características de las células para el desarrollo de nuevas estrategias de tratamiento

Pancreatic ductal adenocarcinoma (PDAC) contains a subset of exclusively tumorigenic cancer stem cells (CSCs) which have been shown to drive tumor ...

Murine Model of Intestinal Ischemia-reperfusion Injury

Intestinal ischemia is a life-threatening condition associated with a broad range of clinical conditions including atherosclerosis, thrombosis, hypotension, necrotizing enterocolitis, bowel transplantation, trauma and chronic inflammation. Intestinal ischemia-reperfusion (IR) injury is a consequence of acute mesenteric ischemia, caused by inadequate blood flow through the mesenteric vessels, resulting in intestinal damage. Reperfusion following ischemia can further exacerbate damage of the intestine. The mechanisms of IR injury are complex and poorly understood. Therefore, experimental small animal models are critical for understanding the pathophysiology of IR injury and the development of novel therapies.
Here we describe a mouse model of acute intestinal IR injury that provides reproducible injury of the small intestine without mortality. This is achieved by inducing ischemia in the region of the distal ileum by temporally occluding the peripheral and terminal collateral branches of the superior mesenteric artery for 60 min using microvascular clips. Reperfusion for 1 hr, or 2 hr after injury results in reproducible injury of the intestine examined by histological analysis. Proper position of the microvascular clips is critical for the procedure. Therefore the video clip provides a detailed visual step-by-step description of this technique. This model of intestinal IR injury can be utilized to study the cellular and molecular mechanisms of injury and regeneration.

Here we describe the detailed procedure of intestinal ischemia-reperfusion in mice which results in reproducible injury without mortality to encourage the standardization of this technique across the field. This model of intestinal ischemia-reperfusion injury can be utilized to study the cellular and molecular mechanisms of injury and regeneration.

Modelo murino de isquemia-reperfusión intestinal Lesiones

Intestinal ischemia is a life-threatening condition associated with a broad range of clinical conditions including atherosclerosis, thrombosis, ...

Creation and Transplantation of an Adipose-derived Stem Cell (ASC) Sheet in a Diabetic Wound-healing Model

Artificial skin has achieved considerable therapeutic results in clinical practice. However, artificial skin treatments for wounds in diabetic patients with impeded blood flow or with large wounds might be prolonged. Cell-based therapies have appeared as a new technique for the treatment of diabetic ulcers, and cell-sheet engineering has improved the efficacy of cell transplantation. A number of reports have suggested that adipose-derived stem cells (ASCs), a type of mesenchymal stromal cell (MSC), exhibit therapeutic potential due to their relative abundance in adipose tissue and their accessibility for collection when compared to MSCs from other tissues. Therefore, ASCs appear to be a good source of stem cells for therapeutic use. In this study, ASC sheets from the epididymal adipose fat of normal Lewis rats were successfully created using temperature-responsive culture dishes and normal culture medium containing ascorbic acid. The ASC sheets were transplanted into Zucker diabetic fatty (ZDF) rats, a rat model of type 2 diabetes and obesity, that exhibit diminished wound healing. A wound was created on the posterior cranial surface, ASC sheets were transplanted into the wound, and a bilayer artificial skin was used to cover the sheets. ZDF rats that received ASC sheets had better wound healing than ZDF rats without the transplantation of ASC sheets. This approach was limited because ASC sheets are sensitive to dry conditions, requiring the maintenance of a moist wound environment. Therefore, artificial skin was used to cover the ASC sheet to prevent drying. The allogenic transplantation of ASC sheets in combination with artificial skin might also be applicable to other intractable ulcers or burns, such as those observed with peripheral arterial disease and collagen disease, and might be administered to patients who are undernourished or are using steroids. Thus, this treatment might be the first step towards improving the therapeutic options for diabetic wound healing.

Creation and Transplantation of an Adipose-derived Stem Cell ASC Sheet in a Diabetic Wound-healing Model

Adipose-derived stem cells (ASCs) are easily isolated and harvested from the fat of normal rats. ASC sheets can be created using cell-sheet engineering and can be transplanted into Zucker diabetic fatty rats exhibiting full-thickness skin defects with exposed bone and then covered with a bilayer of artificial skin.

Creación y el transplante de una hoja de células madre derivadas de adiposo (ASC) en un modelo de curación de herida diabética

Artificial skin has achieved considerable therapeutic results in clinical practice. However, artificial skin treatments for wounds in diabetic patients ...

Two-vessel Occlusion Mouse Model of Cerebral Ischemia-reperfusion

In this study, a middle cerebral artery (MCA) occlusion mouse model is employed to study cerebral ischemia-reperfusion. A reproducible and reliable mouse model is useful for investigating the pathophysiology of cerebral ischemia-reperfusion and determining potential therapeutic strategies for patients with stroke. Variations in the anatomy of the circle of Willis of C57BL/6 mice affects their infarct volume after cerebral-ischemia-induced injury. Studies have indicated that distal MCA occlusion (MCAO) can overcome this problem and result in a stable infarct size. In this study, we establish a two-vessel occlusion mouse model of cerebral ischemia-reperfusion through the interruption of the blood flow to the right MCA. We distally ligate the right MCA and right common carotid artery (CCA) and restore blood flow after a certain period of ischemia. This ischemia-reperfusion injury induces an infarct of stable size and a behavioral deficit. Peripheral immune cells infiltrate the ischemic brain within the 24 h infiltration period. Additionally, the neuronal loss in the cortical area is less for a longer reperfusion duration. Therefore, this two-vessel occlusion model is suitable for investigating the immune response and neuronal recovery during the reperfusion period after cerebral ischemia.

A mouse model of cerebral ischemia-reperfusion is established to investigate the pathophysiology of stroke. We distally ligate the right middle cerebral artery and right common carotid artery and restore blood flow after 10 or 40 min of ischemia.

Oclusión de los vasos dos ratón modelo de isquemia-reperfusión Cerebral

In this study, a middle cerebral artery (MCA) occlusion mouse model is employed to study cerebral ischemia-reperfusion. A reproducible and reliable mouse ...

A Pre-clinical Rat Model for the Study of Ischemia-reperfusion Injury in Reconstructive Microsurgery

Ischemia-reperfusion injury is the main cause of flap failure in reconstructive microsurgery. The rat is the preferred preclinical animal model in many areas of biomedical research due to its cost-effectiveness and its translation to humans. This protocol describes a method to create a preclinical free skin flap model in rats with ischemia-reperfusion injury. The described 3 cm x 6 cm rat free skin flap model is easily obtained after the placement of several vascular ligatures and the section of the vascular pedicle. Then, 8 h after the ischemic insult and completion of the microsurgical anastomosis, the free skin flap develops the tissue damage. These ischemia-reperfusion injury-related damages can be studied in this model, making it a suitable model for evaluating therapeutic agents to address this pathophysiological process. Furthermore, two main monitoring techniques are described in the protocol for the assessment of this animal model: transit-time ultrasound technology and laser speckle contrast analysis.

Here, we describe a pre-clinical animal model for studying the pathophysiology of ischemia-reperfusion injury in reconstructive microsurgery. This free skin flap model based on the superficial caudal epigastric vessels in the rat may also allow for the evaluation of different therapies and compounds to counteract ischemia-reperfusion injury-related damage.

Un modelo preclínico de rata para el estudio de la lesión por isquemia-reperfusión en microcirugía reconstructiva

Ischemia-reperfusion injury is the main cause of flap failure in reconstructive microsurgery. The rat is the preferred preclinical animal model in many ...