Riconosciamo Scott and White Hospital Assegni di Ricerca Programma per il sostegno finanziario e Texas A &amp; M Health Science Center College of Medicine Laboratorio Integrato Imaging per l&#39;utilizzo del microscopio laser confocale. Riconosciamo Mr. Glen Cryer per un aiuto con la modifica del manoscritto.

1. Semina delle cellule endoteliali <ol><li> Ottenere colture primarie di RBMEC di da adulti Sprague Dawley (o ottenerle in commercio). </li><li> Coltivare RBMECs a 100 centimetri fibronectina (50 mg / ml) capsule di Petri rivestita utilizzando il mezzo di crescita delle cellule endoteliali del cervello di ratto. Cambia il mezzo ogni due giorni, fino al raggiungimento di confluenza. </li><li> Giunti 80-90% di confluenza, lavare delicatamente le cellule in 5 ml di tampone fosfato salino (PBS) agitando. Le cellule sono poi staccate esponendoli a 1 ml di soluzione calda 0,25% trypsin- acido etilendiamminotetraacetico (EDTA), equilibrati a 37 ° C. </li><li> Incubare le cellule a 37 ° C per 2-5 minuti fino a quando le cellule vengono staccate e dispersi. NOTA: Toccare il piatto cultura per staccare le cellule. Vista cellule al microscopio per confermare completo distacco di cellule dalla superficie del piatto. </li><li> Aggiungere 5 ml completo supporto alla scatola Petri per neutralizzare tripsina.Pipettare il terreno contenente le cellule staccate e raccogliere in una provetta da centrifuga da 15 ml. . </li><li> Centrifugare il supporto contenente cellule endoteliali a 220 g per 5 min. </li><li> Aspirare il surnatante e conservare il pellet contenente cells.Suspend il pellet in 3-5 ml fresco cervello di ratto mezzo di crescita delle cellule endoteliali delicatamente mescolando su e giù con celle pipetta sarà quindi essere conteggiati con contatore di cellule automatico o un emocitometro. </li><li> Trasferire la sospensione cellulare in fibronectina (50 ug / ml) prerivestita 8 sistema di scorrimento camera ben sterile, 0.7 cm 2 / pozzetto con una densità di semina compreso tra 10.000-15.000 cellule per pozzetto. Far crescere le cellule a 37 ° C fino a confluenza NOTA: per l&#39;esecuzione di macchie occidentali o altri esperimenti, le cellule possono essere coltivate in 10 centimetri piatti di coltura di cellule o piatti speciali, come richiesto dal esperimento. </li></ol> 2. ossigeno e glucosio privazione-riossigenazione in vitroModello NOTA: Il seguente protocollo è stato adattato da Zulueta et al. 1997; Zhu H et al. 2012 8,9. <ol><li> Utilizza il sistema di coltura cellulare all&#39;ipossia per studiare gli effetti di di OGD-R RBMECs in (vedi Figura 1). Setup e calibrare il sistema di coltura cellulare ipossia prima di iniziare l&#39;esperimento, secondo le istruzioni del produttore. </li><li> Rimuovere i vetrini camera confluent (passo 1,8) dalla C incubatore 37 °. Sostituire il terreno completo nella diapositiva da camera con deossigenato, senza glucosio, Modified mezzo di Eagle Dulbecco (DMEM) e posto in camera di ipossia con il 95%, N 2 e 5% di CO 2 per 2 ore a 37 ° C, per rappresentare condizioni OGD. </li><li> Spostare le cellule indietro per l&#39;incubatore con 95% O 2, 5% CO 2 a 37 ° C e provvisto di fresco cervello di ratto cellule endoteliali terreno completo e incubare per un altro 1 ora a 37 ° C. NOTA: Questo passo rappresenta una situazione riossigenazione. </li><li> Utilizzare le diapositive da camera per la localizzazione e l&#39;etichettatura immunofluorescenza rodamina phalloidin (vedi sezione 3). </li></ol> 3. immunofluorescenza Localizzazione di ZO-1 e f Etichettatura actina Utilizzando Rhodamine falloidina <ol><li> Esporre le diapositive da camera contenenti monostrati RBMEC a 100 ml di Opti-MEM / siero ridotta media / bene per 1 ora. Lavare le diapositive camera 3 volte con 100 pl di tampone fosfato salino (PBS, pH 7.0-7.2). </li><li> Fissare le cellule con 100 ml di 4% paraformaldeide in PBS (pH 7.0-7.2) per 15 minuti e lavare i vetrini camera per 3 volte in PBS (pH 7.0-7.2). </li><li> Permeabilize le cellule utilizzando 100 ml di 0,5% Triton X-100 in PBS, pH (7.0-7.2) per altri 15 min. Blocco con 100 ml di 2% di albumina sierica bovina (BSA) in PBS per un&#39;ora. Dopo questo passaggio sia cellule macchia / etichetta sia per ZO-1 o f- actina. <ol><li> Per immunofluorescenza staining Incubare le cellule con un anticorpo anti-coniglio primaria contro ZO-1 a 1: 150, preparata in 2% BSA-PBS per O / N a 4 ° C. Lavare le cellule per 3 volte in PBS, (pH 7.0-7.2). Incubare con 100 ml di fluoresceina isotiocianato (FITC) -tagged anticorpo secondario anti-coniglio per 1 ora a temperatura ambiente. </li><li> Per l&#39;etichettatura Rodamina falloidina, dopo il blocco, esporre le cellule a 100 ml di rhodamine falloidina in diluizione 1:50, preparato nel 2% BSA-PBS, per 20 min. </li><li> Lavare le cellule da immunofluorescenza e l&#39;etichettatura rodamina falloidina in PBS, (pH 7.0-7.2). Montare le camere di utilizzo dei supporti di montaggio contenenti reagenti anti-dissolvenza con DAPI. </li></ol></li><li> Visualizzare le cellule utilizzando una lente immersione in acqua 60 X e le cellule sono scansionati in un unico piano ottico al microscopio confocale. </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. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rho+and+ROCK+signaling+in+VEGF-induced+microvascular+endothelial+hyperpermeability.">Rho and ROCK signaling in VEGF-induced microvascular endothelial hyperpermeability.</a> Microcirculation. 13 (3), 237-247 (2006).</li><li>Doggett, T. M., Breslin, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Study+of+the+actin+cytoskeleton+in+live+endothelial+cells+expressing+GFP+actin.">Study of the actin cytoskeleton in live endothelial cells expressing GFP actin.</a> J Vis Exp. (57), (2011).</li></ol>

The authors have nothing to disclose.

OGD-R come un modello in vitro per danno da ischemia-riperfusione è stato ben definito per studiare i neuroni 10,11. Ci sono anche studi che dimostrano l&#39;effetto di OGD sulle cellule endoteliali cerebrali e alterazioni nella permeabilità e TJ integrità 9. Tuttavia, il nostro studio mostra l&#39;effetto di OGD nonché reoxygenation, che è una rappresentazione più stretta di riperfusione ischemica in condizioni in vivo che si verificano ictus ischemico seguente. <p clas...

Ischemia-riperfusione (IR) ferita si trova ad essere la causa frequente di varie complicazioni debilitanti e decessi associati a ictus, infarto miocardico, trauma, malattia vascolare periferica e traumi cerebrali 1,2. Lesioni IR in vasi cerebrali è uno dei primi lesione secondaria che porta a infiammazione ed edema 3. Una delle complicazioni gravi che si verifica a causa di stress ossidativo e metabolico seguito infiammazione è la perdita di equilibrio omeostatico che porta alla formazione di radicali liberi, alterazioni della barriera emato-encefalica (BBB) ​​giunzioni strette (TJs) e la permeabilità microvascolare 4,5. Attualmente, in modelli in vivo utilizzati per studiare gli effetti di lesioni IR sul BBB includere mezzo occlusione dell&#39;arteria cerebrale (MCAO), microembolia, e transgenici o knockout animali. Tuttavia, ognuno ha i suoi svantaggi e limitazioni come discusso da Hossmann 6. Modello MCAO viene utilizzato per studiare il effects di stress redox, i cambiamenti nella comunicazione giunzionale della BBB e le interazioni tra il cervello e le cellule del sistema immunitario. Tuttavia, essi presentano vari problemi tecnici quali la necessità di precise procedure microchirurgia e le difficoltà in esso. Microembolia rompe istantaneamente lungo la BBB, mentre l&#39;uso di transgenici o knockout animali per studiare ischemia cerebrale può avere sfide come influenze gene-dipendente molecolari sulla formazione infarto, cambiamenti di anatomia vascolare e vari peso corporeo 6. Quindi, modelli in vitro di ischemia hanno trovato un crescente interesse negli ultimi tempi soprattutto a causa della loro applicabilità in esecuzione di studi meccanicistici per i farmaci. Tuttavia, i risultati degli studi in vitro non possono rappresentare appieno uno studio in vivo e devono essere interpretati con cautela 6. Effetto counteractive di basse concentrazioni di ossigeno su monostrati di cellule endoteliali e la permeabilità microvascolare sono statistudiato da Ogawa 7. Cellule endoteliali Rat microvascolari cerebrali (RBMECs) sono stati utilizzati per sviluppare in vitro BBB. La deprivazione di ossigeno e glucosio e riossigenazione (OGD-R) tecnica presentata in questo protocollo è stato adattato da studi di Zulueta et al e Zhu et al 8,9. Abbiamo esposto le cellule endoteliali cerebrali a OGD-R mettendoli in una camera di ipossia / anossia contenente 0% O 2, 5% di CO 2 e il 95% N 2. Le cellule sono state poi valutate per alterazioni TJ integrità e lo stress formazione fibra con localizzazione immunofluorescenza e l&#39;etichettatura falloidina rodamina rispettivamente. Immunofluorescenza colorazione per zonula occludere-1 (ZO-1) viene eseguita per determinare l&#39;integrità TJ, come ZO-1 è un importante membrana ponteggio legato proteina TJ. Etichettatura Rhodamine falloidina determina l&#39;actina filamentosa (f actina) nel citoscheletro cellulare ed è una chiara indicazione di formazione fibra sforzo actina in cellule endoteliali. &lt;p class = &quot;jove_content&quot;&gt; L&#39;obiettivo di questo metodo è quello di fornire una conoscenza di sviluppo OGD-R come un modello in vitro IR per lo studio BBB cellule endoteliali integrità TJ e la formazione di fibre di stress f-actina. I risultati forniranno informazioni sulla sorte di proteine ​​TJ, ZO-1 e la formazione di fibre di stress dopo OGD-R. La comprensione di queste relazioni sarà l&#39;occasione per determinare i meccanismi molecolari alla base che vengono attivati ​​seguendo OGD-R e sviluppare potenziali strategie terapeutiche per migliorare la perturbazione BBB in seguito al trattamento 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

Ischemia-riperfusione (IR) infortunio è noto per contribuire in modo significativo la morbilità e la mortalità associata con ictus ischemico. Accidenti cerebrovascolari ischemiche rappresentano l&#39;80% di tutti i colpi. Una causa comune di lesioni IR è il rapido afflusso di liquidi dopo occlusione acuta / cronica di sangue, nutrienti, ossigeno al tessuto innescando la formazione di radicali liberi. Ictus ischemico è seguito da barriera emato-encefalica (BBB) ​​erettile e edema cerebrale vasogenico. Strutturalmente, giunzioni strette (TJS) tra le cellule endoteliali svolgono un ruolo importante nel mantenimento dell&#39;integrità della barriera ematoencefalica (BBB). Lesioni IR è uno dei primi lesione secondaria che conduce a un non specifico, la risposta infiammatoria. Ossidativo e stress metabolico seguente infiammazione innesca un danno cerebrale secondario compresi BBB permeabilità e la rottura di giunzione a tenuta (TJ) integrità. Il nostro protocollo presenta in vitro &lt;/ Em&gt; esempio di deprivazione di ossigeno e glucosio e riossigenazione (OGD-R) su cellule endoteliali cervello di ratto TJ integrità e la formazione di fibre di stress. Attualmente, molti sperimentale in modelli in vivo vengono utilizzati per studiare gli effetti di lesioni IR; ma hanno alcune limitazioni, come le difficoltà tecniche per l&#39;esecuzione di interventi chirurgici, le influenze genetiche e molecolari dipendenti difficoltà di studiare le relazioni meccanicistiche. Tuttavia, i modelli in vitro possono aiutare a superare molti di questi limiti. Il protocollo presentato può essere usato per studiare i vari meccanismi molecolari e relazioni meccanicistici di fornire potenziali strategie terapeutiche. Tuttavia, i risultati degli studi in vitro possono essere diverse dallo standard studi in vivo e devono essere interpretati con cautela.

Le cellule coltivate su fibronectina pretrattata camera di diapositive Nunc II sono stati sottoposti ad OGD-R mettendo in un modello Biospherix ProOx 110 camera. Dopo aver sottoposto celle a OGD-R, sono stati trattati per ZO-1 giunzionale colorazione utilizzando la tecnica di immunofluorescenza come mostrato in figura 2 e l&#39;assemblaggio del citoscheletro indicando fibra formazione di stress F-actina usando label macchia rodamina falloidina come mostrato in figura 3. Le cellule di co...

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.

L&#39;ossigeno-glucosio Deprivazione e riossigenazione come<em&gt; In Vitro</em&gt; Ischemia-riperfusione Injury modello per lo studio barriera sanguigna del cervello Erettile

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

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Medicine

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

17.8K Views.  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.

Normotermico arresto cardiaco e rianimazione cardiopolmonare: un modello murino di ischemia-riperfusione

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 ...

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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.

Trapianto di cellule staminali in un In vitro Simulato ischemia / riperfusione Modello

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.

Ischemia-riperfusione Modello di danno renale acuta e post Infortunio fibrosi nei topi

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.

Stretch in microvascolari cerebrali cellule endoteliali (CEND) come<em&gt; In Vitro</em&gt; Trauma cranico modello della barriera ematoencefalica

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.

Istituzione di un<em&gt; In Vitro</em&gt; Modello di Rat barriera emato-encefalica (BBB): A Focus on BBB impermeabilità e Trasporti recettore-mediata

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.

Modello murino di ischemia-riperfusione intestinale Injury

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.

Migliorato il metodo per la creazione di un In Vitro barriera emato - encefalica modello basato sulle cellule endoteliali Porcine cervello

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.

Valutazione della riserva del flusso coronario dopo la miaocardia Ischemia Reperfusione nei ratti

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 modello di ratto preclinico per lo studio delle lesioni ischemia-reperfusione in microchirurgia ricostruttiva

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.

Consegna intramiocardica ritardata di cellule staminali dopo l'infortunio di ricottamento ischemia in un modello Murine

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