Reconocemos Programa de Subvenciones del Hospital Blanca, Scott y de apoyo financiero y de Texas A &amp; M Health Science Center College de Medicina de Laboratorio Integrado de imagen para el uso del microscopio láser confocal. Reconocemos el Sr. Glen Cryer para obtener ayuda con la edición de manuscritos.

1. Siembra de las células endoteliales <ol><li> Obtener cultivos primarios de RBMEC de de ratas Sprague Dawley adultas (u obtener comercialmente). </li><li> Cultivar RBMECs en 100 cm fibronectina (50 mg / ml) placas de Petri recubiertas utilizando el medio de crecimiento de células endoteliales de cerebro de rata. Cambiar el medio cada dos días, hasta que se alcanza la confluencia. </li><li> Al llegar a 80-90% de confluencia, lavar suavemente las células en 5 ml de solución salina tamponada con fosfato (PBS) por agitación. Las células se separaron entonces al exponerlos a 1 ml de solución caliente 0,25% tripsina ácido etilendiaminotetraacético (EDTA), equilibrada a 37 ° C. </li><li> Se incuban las células a 37 ° C durante 2-5 min hasta que las células se separan y se dispersan. NOTA: Toque en la placa de cultivo para separar las células. Ver las células bajo el microscopio para confirmar desprendimiento completo de células de la superficie del plato. </li><li> Añadir 5 ml de medios completa a la placa de Petri con el fin de neutralizar la tripsina.Pipetear el medio que contiene células desprendidas y recoger en un tubo de centrífuga de 15 ml. . </li><li> Centrifugar el medio que contiene las células endoteliales a 220 xg durante 5 min. </li><li> Aspirar el sobrenadante y el sedimento que contiene preservar cells.Suspend el sedimento en 3-5 medio de crecimiento de células endoteliales de cerebro de rata fresco por ml de mezcla suavemente arriba y abajo con pipeta células serán entonces ser contado usando un contador de células automatizado o un hemocitómetro. </li><li> Transferir la suspensión celular en la fibronectina (50 mg / ml) pre-revestido 8 sistema de diapositiva cámara de pocillo estéril, 0,7 cm 2 / pocillo con una densidad de siembra varía entre 10.000-15.000 células por pocillo. Cultivar las células a 37 ° C hasta que se logra la confluencia NOTA: Para la realización de transferencias Western u otros experimentos, las células se pueden cultivar en placas de 10 cm de cultivo de células o platos especiales como es requerido por el experimento. </li></ol> 2. El oxígeno y glucosa Privación-Reoxigenación In VitroModelo NOTA: El siguiente protocolo se ha adaptado de Zulueta et al. 1997; Zhu H et al. 2012 8,9. <ol><li> Utilice el sistema de cultivo celular hipoxia para estudiar los efectos de de la OGD-R en RBMECs en (ver Figura 1). Configuración y calibrar el sistema de cultivo celular hipoxia antes de comenzar el experimento, de acuerdo con las instrucciones del fabricante. </li><li> Retire los portaobjetos de cámara confluentes (paso 1.8) de la 37 ° C incubadora. Sustituir el medio completo en el portaobjetos de cámara con desoxigenada, no glucosa, Medio de Eagle Modificado de Dulbecco (DMEM) y se coloca en la cámara de hipoxia con 95%, N 2 y 5% de CO 2 durante 2 horas a 37 ° C, para representar condición OGD. </li><li> Mover las células de nuevo a la incubadora con 95% O 2, 5% de CO2 a 37 ° C y provisto de medio completo de células endoteliales de cerebro de rata fresco y se incuba durante otra 1 hora a 37 ° C. NOTA: Este paso representa una situación reoxigenación. </li><li> Utilice los portaobjetos de cámara para la localización de inmunofluorescencia y el etiquetado rodamina phalloidin (ver sección 3). </li></ol> 3. Inmunofluorescencia localización de ZO-1 y F-actina Etiquetado Usando Rodamina faloidina <ol><li> Exponer los portaobjetos de cámara que contienen monocapas RBMEC a 100 l de Opti-MEM / suero reducida medios de comunicación / pocillo durante 1 hr. Lavar los portaobjetos de cámara 3 veces en 100 l de solución salina tamponada con fosfato (PBS, pH 7,0 a 7,2). </li><li> Fijar las células utilizando 100 l de paraformaldehído al 4% en PBS (pH 7,0-7,2) durante 15 min y se lavan los portaobjetos de cámara de 3 veces más en PBS (pH 7,0-7,2). </li><li> Permeabilizar las células usando 100 l de 0,5% de Triton X-100 en PBS, (pH 7,0-7,2) durante otros 15 min. Bloquear con 100 l de 2% de albúmina de suero bovino (BSA) en PBS durante una hora. Después de este paso, ya sea células mancha / etiqueta, ya sea para ZO-1 o f- actina. <ol><li> Para sta inmunofluorescenciacaniza incuban las células con un anticuerpo anti-conejo primaria contra ZO-1 en 1: 150, preparado en 2% BSA-PBS durante O / N a 4 ° C. Lavar las células 3 veces en PBS, (pH 7,0-7,2). Incubar con 100 l de isotiocianato de fluoresceína (FITC)-etiquetados anti-conejo anticuerpo secundario durante 1 hr a RT. </li><li> Para el etiquetado rodamina faloidina, tras el bloqueo, exponer las células a 100 l de rodamina faloidina en dilución 1:50, preparado en 2% BSA-PBS, durante 20 min. </li><li> Lavar las células de la tinción de inmunofluorescencia y rodamina faloidina etiquetado en PBS, (pH 7,0-7,2). Montar las cámaras que utilizan medios de fijación que contienen reactivo anti-fade con DAPI. </li></ol></li><li> Visualizar las células usando una lente de inmersión en agua 60 X y las células se escanean en un solo plano óptico bajo un microscopio confocal. </li></ol>

<ol>
	<li>Eltzschig, H. K., Eckle, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ischemia+and+reperfusion--from+mechanism+to+translation.">Ischemia and reperfusion--from mechanism to translation.</a> Nat Med. 17 (11), 1391-1401 (2011).</li><li>Kalogeris, T., Baines, C. P., Krenz, M., Korthuis, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+biology+of+ischemia/reperfusion+injury.">Cell biology of ischemia/reperfusion injury.</a> Int Rev Cell Mol Biol. 298, 229-317 (2012).</li><li>Yang, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lycium+barbarum+polysaccharides+reduce+intestinal+ischemia/reperfusion+injuries+in+rats.">Lycium barbarum polysaccharides reduce intestinal ischemia/reperfusion injuries in rats.</a> Chem Biol Interact. 204 (3), 166-172 (2013).</li><li>Kaur, C., Ling, E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blood+brain+barrier+in+hypoxic-ischemic+conditions.">Blood brain barrier in hypoxic-ischemic conditions.</a> Curr Neurovasc Res. 5 (1), 71-81 (2008).</li><li>Khatri, R., McKinney, A. M., Swenson, B., Janardhan, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blood-brain+barrier,+reperfusion+injury,+and+hemorrhagic+transformation+in+acute+ischemic+stroke.">Blood-brain barrier, reperfusion injury, and hemorrhagic transformation in acute ischemic stroke.</a> Neurology. 79 (13), S52-S57 (2012).</li><li>Hossmann, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+models+for+the+investigation+of+brain+ischemia.">Experimental models for the investigation of brain ischemia.</a> Cardiovasc Res. 39, 106-120 (1998).</li><li>Ogawa, S., Gerlach, H., Esposito, C., Pasagian-Macaulay, A., Brett, J., Stern, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hypoxia+modulates+the+barrier+and+coagulant+function+of+cultured+bovineendothelium.+Increased+monolayer+permeability+and+induction+of+procoagulant+properties.">Hypoxia modulates the barrier and coagulant function of cultured bovineendothelium. Increased monolayer permeability and induction of procoagulant properties.</a> J Clin Invest. 85 (4), 1090-108 (1990).</li><li>Zulueta, J. J., Sawhney, R., Yu, F. S., Cote, C. C., Hassoun, P. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intracellular+generation+of+reactive+oxygen+species+in+endothelial+cellsexposed+to+anoxia-reoxygenation.">Intracellular generation of reactive oxygen species in endothelial cellsexposed to anoxia-reoxygenation.</a> Am J Physiol. 272 (5 Pt 1), L897-L902 (1997).</li><li>Zhu, H., 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=Baicalin+reduces+the+permeability+of+the+blood-brain+barrier+during+hypoxia+in+vitro+by+increasing+the+expression+of+tight+junction+proteins+in+brain+microvascular+endothelial+cells.">Baicalin reduces the permeability of the blood-brain barrier during hypoxia in vitro by increasing the expression of tight junction proteins in brain microvascular endothelial cells.</a> J Ethnopharmacol. 141 (2), 714-720 (2012).</li><li>Abramov, A. Y., Scorziello, A., Duchen, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three+distinct+mechanisms+generate+oxygen+free+radicals+in+neurons+and+contribute+to+cell+death+during+anoxia+and+reoxygenation.">Three distinct mechanisms generate oxygen free radicals in neurons and contribute to cell death during anoxia and reoxygenation.</a> J Neurosci. 27 (5), 1129-1138 (2007).</li><li>Gundimeda, U., 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=Green+tea+polyphenols+precondition+against+cell+death+induced+by+oxygen-glucose+deprivation+via+stimulation+of+laminin+receptor,+generation+of+reactive+oxygen+species,+and+activation+of+protein+kinase+Cepsilon.">Green tea polyphenols precondition against cell death induced by oxygen-glucose deprivation via stimulation of laminin receptor, generation of reactive oxygen species, and activation of protein kinase Cepsilon.</a> J Biol Chem. 287 (41), 34694-34708 (2012).</li><li>Mehta, S. L., Manhas, N., Raghubir, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+targets+in+cerebral+ischemia+for+developing+novel+therapeutics.">Molecular targets in cerebral ischemia for developing novel therapeutics.</a> Brain Res Rev. 54 (1), 34-66 (2007).</li><li>Alluri, H., 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=Reactive+Oxygen+Species-Caspase-3+Relationship+in+Mediating+Blood-Brain+Barrier+Endothelial+Cell+Hyperpermeability+Following+Oxygen-Glucose+Deprivation+and+Reoxygenation.">Reactive Oxygen Species-Caspase-3 Relationship in Mediating Blood-Brain Barrier Endothelial Cell Hyperpermeability Following Oxygen-Glucose Deprivation and Reoxygenation.</a> Microcirculation. 21 (2), 187-195 (1111).</li><li>Sun, H., Breslin, J. W., Zhu, J., Yuan, S. Y., Wu, M. 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The authors have nothing to disclose.

OGD-R como un modelo in vitro para la lesión por isquemia-reperfusión ha sido bien establecido para el estudio de las neuronas 10,11. También hay estudios que muestran el efecto de la OGD en las células endoteliales cerebrales y alteraciones en la permeabilidad y TJ integridad 9. Sin embargo, nuestro estudio muestra el efecto de OGD, así como la reoxigenación, que es una representación más cercana de la lesión por reperfusión isquémica en condiciones in vivo que se prod...

-Isquemia-reperfusión (IR) lesión se encuentra que es la causa frecuente de diversas complicaciones debilitantes y muertes asociadas con el accidente cerebrovascular, infarto de miocardio, trauma, enfermedad vascular periférica y lesión cerebral traumática 1,2. IR lesión en los vasos cerebrales es una lesión secundaria temprana conduce a la inflamación y el edema 3. Una de las complicaciones graves que se produce como resultado de estrés oxidativo y metabólica después de la inflamación es la pérdida de equilibrio homeostático conduce a la formación de radicales libres, alteraciones en la barrera hematoencefálica (BBB) ​​uniones estrechas (TJs) y la permeabilidad microvascular 4,5. Actualmente, en modelos in vivo utilizados para estudiar los efectos de la lesión por IR en la BBB incluir oclusión de la arteria cerebral media (MCAO), microembolismo, y transgénicos o knockout animales. Sin embargo, cada uno tiene sus inconvenientes y limitaciones como se comenta por Hossmann 6. Modelo MCAO se utiliza para estudiar la effects de estrés redox, cambios en las comunicaciones de unión de la acreditación y las interacciones entre el cerebro y las células inmunes. Sin embargo, presentan varios desafíos técnicos, como la necesidad de procedimientos de microcirugía precisas y las dificultades en el mismo. Microembolismo instantáneamente rompe la acreditación mientras que el uso de transgénicos o knockout animales para estudiar la isquemia cerebral puede tener retos como influencias de genes dependientes moleculares sobre la formación del infarto, los cambios en la anatomía vascular y diferentes pesos corporales 6. Por lo tanto, los modelos in vitro de isquemia han encontrado un interés creciente en los últimos tiempos debido principalmente a su aplicabilidad en la realización de estudios mecanísticos de drogas. Sin embargo, los resultados de los estudios in vitro no pueden representar plenamente un estudio in vivo y deben ser interpretados con cautela 6. Efecto contraproducente de bajas concentraciones de oxígeno en monocapas de células endoteliales y la permeabilidad microvascular haber sidoestudiado por Ogawa 7. Células endoteliales microvasculares de cerebro de rata (RBMECs) se utilizaron para desarrollar in vitro BBB. La técnica de la privación y la reoxigenación con oxígeno glucosa (OGD-R) se presenta en este protocolo ha sido adaptado de estudios de Zulueta y otros y Zhu et al 8,9. Se expuso células endoteliales cerebrales a OGD-R colocándolos en una cámara de hipoxia / anoxia que contiene 0% de O 2, 5% de CO 2 y 95% N 2. Las células fueron posteriormente evaluados por alteraciones en la formación de fibras integridad y el estrés TJ utilizando la localización de inmunofluorescencia y el etiquetado rodamina phalloidin respectivamente. La tinción de inmunofluorescencia para occludens-1 zonula (ZO-1) se realiza para determinar la integridad de TJ, como ZO-1 es una membrana andamios importante obligado proteínas TJ. Etiquetado rodamina faloidina determina la actina filamentosa (F-actina) en el citoesqueleto celular y es una clara indicación de la formación de fibras de estrés de actina en las células endoteliales. &lt;p class = &quot;jove_content&quot;&gt; El objetivo de este método es para proporcionar una visión en el desarrollo de OGD-R como un modelo in vitro para el estudio de IR BBB células endoteliales integridad TJ y la formación de fibras de estrés de actina-f. Los resultados proporcionarán información sobre la suerte de proteínas TJ, ZO-1 y la formación de fibras de estrés después de la OGD-R. La comprensión de estas relaciones será una oportunidad para determinar los mecanismos moleculares subyacentes que se activan siguiendo OGD-R y desarrollar posibles estrategias terapéuticas para mejorar la interrupción acreditación después del tratamiento OGD-R.

<table border="0" cellpadding="0" cellspacing="0" width="917">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:371px;">Name of Material/ Equipment</td>
			<td style="width:167px;">Company</td>
			<td style="width:129px;">Catalog Number</td>
			<td style="width:251px;">Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:371px;">Proox model 110</td>
			<td style="width:167px;">Biospherix</td>
			<td style="width:129px;">Model 110</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:371px;">DMEM, no glucose</td>
			<td style="width:167px;">Gibco, Life technologies</td>
			<td style="width:129px;">11966-025</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:371px;">Rhodamine Phalloidin</td>
			<td style="width:167px;">Life technologies</td>
			<td style="width:129px;">R415</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:371px;">ZO-1 Rabbit Polyclonal Antibody</td>
			<td style="width:167px;">Life technologies</td>
			<td align="right" style="width:129px;">617300</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Nunc Lab Tek II-CC 8&#160;well sterile, glass&#160;slides&#160;</td>
			<td style="width:167px;">Thermo scientific</td>
			<td align="right" style="width:129px;">177402</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">FITC-tagged anti-rabbit secondary antibody&#160;</td>
			<td style="width:167px;">Santa cruz</td>
			<td style="width:129px;">sc-2090</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:371px;">DPBS 1X</td>
			<td style="width:167px;">Thermo scientific</td>
			<td style="width:129px;">SH 30028.03</td>
			<td>Any other PBS available can be used</td>
		</tr>
	</tbody>
</table>

oxygen-glucose deprivation and reoxygenation as an in vitro ischemia-reperfusion injury model for studying blood-brain barrier dysfunction

La isquemia-reperfusión (IR) lesión se sabe que contribuyen significativamente a la morbilidad y la mortalidad asociadas con accidentes cerebrovasculares isquémicos. Accidentes cerebrovasculares isquémicos representan el 80% de todos los accidentes cerebrovasculares. Una causa común de lesión IR es el rápido flujo de entrada de fluidos después de una oclusión crónica / aguda de sangre, nutrientes, oxígeno al tejido desencadenar la formación de radicales libres. El ictus isquémico es seguido por la barrera hematoencefálica (BBB) ​​y la disfunción edema cerebral vasogénico. Estructuralmente, las uniones estrechas (TJS) entre las células endoteliales juegan un papel importante en el mantenimiento de la integridad de la barrera hematoencefálica (BBB). IR lesión es una lesión secundaria temprana que conduce a una respuesta no específica, inflamatoria. Oxidativo y estrés metabólico después de la inflamación desencadena el daño cerebral secundario que incluye la acreditación de la permeabilidad y la interrupción de uniones estrechas (TJ) integridad. Nuestro protocolo presenta in vitro &lt;/ Em&gt; ejemplo de la privación de oxígeno y glucosa reoxigenación (OGD-R) en las células endoteliales de cerebro de rata integridad TJ y la formación de fibras de estrés. Actualmente, varios experimental en modelos in vivo se utilizan para estudiar los efectos de la lesión IR; sin embargo, tienen varias limitaciones, como los desafíos técnicos en la realización de cirugías, gen influencias moleculares dependientes y dificultad en el estudio de las relaciones mecanicistas. Sin embargo, los modelos in vitro puede ayudar a superar muchas de esas limitaciones. El protocolo presentado puede ser usado para estudiar los diversos mecanismos moleculares y relaciones mecanicistas para proporcionar estrategias terapéuticas potenciales. Sin embargo, los resultados de los estudios in vitro pueden diferir de serie en estudios in vivo y deben ser interpretados con cautela.

Las células cultivadas en portaobjetos prerrevestidas fibronectina cámara Nunc II fueron sometidos a OGD-R mediante la colocación en un modelo de cámara de 110 Biospherix ProOx. Después de someter las células a OGD-R, que se procesaron para ZO-1 tinción de unión utilizando la técnica de inmunofluorescencia como se muestra en la Figura 2 y el conjunto de citoesqueleto que indica la formación de fibras de estrés de actina F usando etiqueta mancha faloidina rodamina como se muestra en la...

Watch this Scientific Journal Video about Oxygen-Glucose Deprivation and Reoxygenation as an In Vitro Ischemia-Reperfusion Injury Model for Studying Blood-Brain Barrier Dysfunction at JoVE.com

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 ...

oxygen-glucose-deprivation-reoxygenation-as-an-vitro-ischemia

Research

JoVE Journal

Medicine

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

17.8K vistas.  Texas A&M University Health Science Center College of Medicine. 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. 

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

Normothermic Cardiac Arrest and Cardiopulmonary Resuscitation: A Mouse Model of Ischemia-Reperfusion Injury

Acute Kidney Injury (AKI) is a common, highly lethal, complication of critical illness which has a high mortality1-4 and which is most 
frequently caused by whole-body hypoperfusion.5,6 Successful reproduction of whole-body hypoperfusion in rodent models has been fraught with 
difficulty.7-9,9,10 Models which employ focal ischemia have repeatedly demonstrated results which do not translate to the clinical setting, and larger 
animal models which allow for whole body hypoperfusion lack access to the full toolset of genetic manipulation possible in the mouse.11,12 However, in recent 
years a mouse model of cardiac arrest and cardiopulmonary resuscitation has emerged which can be adapted to model AKI.13 This model reliably reproduces 
physiologic, functional, anatomic, and histologic outcomes seen in clinical AKI, is rapidly repeatable, and offers all of the significant advantages of a murine surgical 
model, including access to genetic manipulative techniques, low cost relative to large animals, and ease of use. Our group has developed extensive experience 
with use of this model to assess a number of organ-specific outcomes in AKI.14,15

A powerful model for perioperative and critical care related acute kidney injury is presented. Using whole body hypoperfusion induced by cardiac arrest it is possible to nearly replicate the histologic and functional changes of clinical AKI.

Arresto normotérmica cardiaca y reanimación cardiopulmonar: un modelo de ratón de la lesión por isquemia-reperfusión

Acute Kidney Injury (AKI) is a common, highly lethal, complication of critical illness which has a high mortality1-4 and which is most 
frequently caused ...

Investigación

Medicina

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

Stem cell transplantation protocols are finding their way into clinical practice1,2,3. Getting better results, making the protocols more robust, and finding new sources for implantable cells are the focus of recent research4,5. Investigating the effectiveness of cell therapies is not an easy task and new tools are needed to investigate the mechanisms involved in the treatment process6. We designed an experimental protocol of ischemia/reperfusion in order to allow the observation of cellular connections and even subcellular mechanisms during ischemia/reperfusion injury and after stem cell transplantation and to evaluate the efficacy of cell therapy. H9c2 cardiomyoblast cells were placed onto cell culture plates7,8. Ischemia was simulated with 150 minutes in a glucose free medium with oxygen level below 0.5%. Then, normal media and oxygen levels were reintroduced to simulate reperfusion. After oxygen glucose deprivation, the damaged cells were treated with transplantation of labeled human bone marrow derived mesenchymal stem cells by adding them to the culture. Mesenchymal stem cells are preferred in clinical trials because they are easily accessible with minimal invasive surgery, easily expandable and autologous. After 24 hours of co-cultivation, cells were stained with calcein and ethidium-homodimer to differentiate between live and dead cells. This setup allowed us to investigate the intercellular connections using confocal fluorescent microscopy and to quantify the survival rate of postischemic cells by flow cytometry. Confocal microscopy showed the interactions of the two cell populations such as cell fusion and formation of intercellular nanotubes. Flow cytometry analysis revealed 3 clusters of damaged cells which can be plotted on a graph and analyzed statistically. These populations can be investigated separately and conclusions can be drawn on these data on the effectiveness of the simulated therapeutical approach.

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

We demonstrate how to set up an in vitro ischemia/reperfusion model and how to evaluate the effect of stem cell therapy on postischemic cardiac cells.

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 ...

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 ...

Stretch in Brain Microvascular Endothelial Cells (cEND) as an In Vitro Traumatic Brain Injury Model of the Blood Brain Barrier

Due to the high mortality incident brought about by traumatic brain injury (TBI), methods that would enable one to better understand the underlying mechanisms involved in it are useful for treatment. There are both in vivo and in vitro methods available for this purpose. In vivo models can mimic actual head injury as it occurs during TBI. However, in vivo techniques may not be exploited for studies at the cell physiology level. Hence, in vitro methods are more advantageous for this purpose since they provide easier access to the cells and the extracellular environment for manipulation.
Our protocol presents an in vitro model of TBI using stretch injury in brain microvascular endothelial cells. It utilizes pressure applied to the cells cultured in flexible-bottomed wells. The pressure applied may easily be controlled and can produce injury that ranges from low to severe. The murine brain microvascular endothelial cells (cEND) generated in our laboratory is a well-suited model for the blood brain barrier (BBB) thus providing an advantage to other systems that employ a similar technique. In addition, due to the simplicity of the method, experimental set-ups are easily duplicated. Thus, this model can be used in studying the cellular and molecular mechanisms involved in TBI at the BBB.

Stretch in Brain Microvascular Endothelial Cells cEND as an In Vitro Traumatic Brain Injury Model of the Blood Brain Barrier

In vitro traumatic brain injury models are being developed to reproduce in vivo brain deformation. Stretch-induced injury has been employed for astrocytes, neurons, glial cells, aortic, and brain endothelial cells. However, our system uses a blood brain barrier (BBB) model that possesses properties constituting a legitimate model of the BBB to establish an in vitro&#160;TBI model.

Estirar en Brain células endoteliales microvasculares (CEND) como<em&gt; In Vitro</em&gt; Lesión cerebral traumática Modelo de la barrera hematoencefálica

Due to the high mortality incident brought about by traumatic brain injury (TBI), methods that would enable one to better understand the underlying ...

Setting-up an In Vitro Model of Rat Blood-brain Barrier (BBB): A Focus on BBB Impermeability and Receptor-mediated Transport

The blood brain barrier (BBB) specifically regulates molecular and cellular flux between the blood and the nervous tissue. Our aim was to develop and characterize a highly reproducible rat syngeneic in vitro model of the BBB using co-cultures of primary rat brain endothelial cells (RBEC) and astrocytes to study receptors involved in transcytosis across the endothelial cell monolayer. Astrocytes were isolated by mechanical dissection following trypsin digestion and were frozen for later co-culture. RBEC were isolated from 5-week-old rat cortices. The brains were cleaned of meninges and white matter, and mechanically dissociated following enzymatic digestion. Thereafter, the tissue homogenate was centrifuged in bovine serum albumin to separate vessel fragments from nervous tissue. The vessel fragments underwent a second enzymatic digestion to free endothelial cells from their extracellular matrix. The remaining contaminating cells such as pericytes were further eliminated by plating the microvessel fragments in puromycin-containing medium. They were then passaged onto filters for co-culture with astrocytes grown on the bottom of the wells. RBEC expressed high levels of tight junction (TJ) proteins such as occludin, claudin-5 and ZO-1 with a typical localization at the cell borders. The transendothelial electrical resistance (TEER) of brain endothelial monolayers, indicating the tightness of TJs reached 300 ohm&#183;cm2 on average. The endothelial permeability coefficients (Pe) for lucifer yellow (LY) was highly reproducible with an average of 0.26 &#177;&#160;0.11 x 10-3 cm/min. Brain endothelial cells organized in monolayers expressed the efflux transporter P-glycoprotein (P-gp), showed a polarized transport of rhodamine 123, a ligand for P-gp, and showed specific transport of transferrin-Cy3 and DiILDL across the endothelial cell monolayer. In conclusion, we provide a protocol for setting up an in vitro BBB model that is highly reproducible due to the quality assurance methods, and that is suitable for research on BBB transporters and receptors.

Setting-up an In Vitro Model of Rat Blood-brain Barrier BBB: A Focus on BBB Impermeability and Receptor-mediated Transport

The aim of the present study was to validate the reproducibility of an in vitro BBB model involving a rat syngeneic co-culture of endothelial cells and astrocytes. The endothelial cell monolayer presented high TEER and low LY permeability. Expression of specific TJ proteins, functional responses to inflammation and functionality of transporters and receptors were assessed.

Establecimiento de un<em&gt; In Vitro</em&gt; Modelo de Rata barrera hematoencefálica (BBB): Un Enfoque en la acreditación Impermeabilidad y transporte mediado por los receptores

The blood brain barrier (BBB) specifically regulates molecular and cellular flux between the blood and the nervous tissue. Our aim was to develop and ...

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, ...

Improved Method for the Establishment of an In Vitro Blood-Brain Barrier Model Based on Porcine Brain Endothelial Cells

The aim of this protocol presents an optimized procedure for the purification and cultivation of pBECs and to establish in vitro blood-brain barrier (BBB) models based on pBECs in mono-culture (MC), MC with astrocyte-conditioned medium (ACM), and non-contact co-culture (NCC) with astrocytes of porcine or rat origin. pBECs were isolated and cultured from fragments of capillaries from the brain cortices of domestic pigs 5-6 months old. These fragments were purified by careful removal of meninges, isolation and homogenization of grey matter, filtration, enzymatic digestion, and centrifugation. To further eliminate contaminating cells, the capillary fragments were cultured with puromycin-containing medium. When 60-95% confluent, pBECs growing from the capillary fragments were passaged to permeable membrane filter inserts and established in the models. To increase barrier tightness and BBB characteristic phenotype of pBECs, the cells were treated with the following differentiation factors: membrane permeant 8-CPT-cAMP (here abbreviated cAMP), hydrocortisone, and a phosphodiesterase inhibitor, RO-20-1724 (RO). The procedure was carried out over a period of 9-11 days, and when establishing the NCC model, the astrocytes were cultured 2-8 weeks in advance. Adherence to the described procedures in the protocol has allowed the establishment of endothelial layers with highly restricted paracellular permeability, with the NCC model showing an average transendothelial electrical resistance (TEER) of 1249 &#177; 80 &#937; cm2, and paracellular permeability (Papp) for Lucifer Yellow of 0.90 10-6 &#177; 0.13 10-6 cm sec-1 (mean &#177; SEM, n=55). Further evaluation of this pBEC phenotype showed good expression of the tight junctional proteins claudin 5, ZO-1, occludin and adherens junction protein p120 catenin. The model presented can be used for a range of studies of the BBB in health and disease and, with the highly restrictive paracellular permeability, this model is suitable for studies of transport and intracellular trafficking.

Improved Method for the Establishment of an In Vitro Blood-Brain Barrier Model Based on Porcine Brain Endothelial Cells

The aim of the protocol is to present an optimized procedure for the establishment of an in vitro blood-brain barrier (BBB) model based on primary porcine brain endothelial cells (pBECs). The model shows high reproducibility, high tightness, and is suitable for studies of transport and intracellular trafficking in drug discovery.

Mejor método para el establecimiento de un In Vitro Barrera Blood - Brain modelo basado en las células endoteliales de cerebro porcino

The aim of this protocol presents an optimized procedure for the purification and cultivation of pBECs and to establish in vitro blood-brain barrier (BBB) ...

Evaluation of Coronary Flow Reserve After Myocardial Ischemia Reperfusion in Rats

Coronary artery disease is the leading cause of death worldwide. After an acute myocardial infarction, early and successful myocardial intervention via recanalization of the coronary artery is the most effective strategy for reducing the size of ischemic myocardium. The coronary microvasculature cannot be visualized and imaged&#160;in vivo, but there are several invasive and noninvasive techniques that can be used to assess parameters which depend directly on coronary microvascular function. The endothelial function after ischemia reperfusion can be assessed also at the level of the coronary circulation via the coronary flow reserve (CFR).&#160;In this study, peak velocity of left anterior descending (LAD) coronary arteries was measured in rats in vivo via Transthoracic Doppler Echocardiography during resting and stress challenge (induced by Dobutamine). A normal heart can increase its coronary blood flow up to four times above the resting values during stress induction. Following ischemia reperfusion, we found a significantly diminished CFR, which can be used as a marker of coronary microvascular dysfunction. CFR has opened a window on the importance of microvascular dysfunction and has been shown to predict cardiovascular risk independent of whether the severe obstructive disease is present.

Coronary flow reserve (CFR), is defined as the ratio of maximal coronary blood flow to the resting coronary blood flow. We present a protocol for evaluating CFR in rats via ultrasound, which offers the opportunity to predict cardiovascular risk factors in the absence of obstructive coronary disease.

Evaluación de la Reserva de Flujo Coronario Después de la Reperfusión de Isquemia Miocárdica en Ratas

Coronary artery disease is the leading cause of death worldwide. After an acute myocardial infarction, early and successful myocardial intervention via ...

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 ...

Delayed Intramyocardial Delivery of Stem Cells after Ischemia Reperfusion Injury in a Murine Model

There is significant interest in the use of stem cells (SCs) for the recovery of cardiac function in individuals with myocardial injuries. Most commonly, cardiac stem cell therapy is studied by delivering SCs concurrently with the induction of myocardial injury. However, this approach presents two significant limitations: the early hostile pro-inflammatory ischemic environment may affect the survival of transplanted SCs, and it does not represent the subacute infarction scenario where SCs will likely be used. Here we describe a two-part series of surgical procedures for the induction of ischemia-reperfusion injury and delivery of mesenchymal stem cells (MSCs). This method of stem cell administration may allow for the longer viability and retention around damaged tissue by circumventing the initial immune response. A model of ischemia reperfusion injury was induced in mice accompanied by the delivery of mesenchymal stem cells (3.0 x 105), stably expressing the reporter gene firefly luciferase under the constitutively expressed CMV promoter, intramyocardially 7 days later. The animals were imaged via ultrasound and bioluminescent imaging for confirmation of injury and injection of cells, respectively. Importantly, there was no added complication rate when performing this two-procedure approach for SC delivery. This method of stem cell administration, collectively with the utilization of state-of-the-art reporter genes, may allow for the in vivo study of viability and retention of transplanted SCs in a situation of chronic ischemia commonly seen clinically, while also circumventing the initial pro-inflammatory response. In summary, we established a protocol for the delayed delivery of stem cells into the myocardium, which can be used as a potential new approach in promoting regeneration of the damaged tissue.

Stems cells are continuously investigated as potential treatments for individuals with myocardial damage, however, their decreased viability and retention within injured tissue can impact their long-term efficacy. In this manuscript we describe an alternative method for stem cell delivery in a murine model of ischemia reperfusion injury.

Retraso en la administración intramiocardio de células madre después de la lesión por reperfusión de isquemia en un modelo murino

There is significant interest in the use of stem cells (SCs) for the recovery of cardiac function in individuals with myocardial injuries. Most commonly, ...