Este trabalho foi financiado pela OTKA (Hungarian Fundo de Investigação Científica) D45933, T049621, TET (Hungarian Ciência e Tecnologia Foundation) A4/04, Arg-17/2006 e SIN, Bolyai, Bolsas e Öveges TÁMOP 4.2.2-08 / 1 / KMR-2008-0004 e 4.2.1 / B 09/1/KMR-2010-0001. OTKA 83803. Gostaríamos de agradecer Gesztes William para fornecer a voz-over.

1. Preparando H9c2 células cardiomyoblast H9c2 cardiomyoblasts ratos foram obtidos a partir ATCC (Wesel, Alemanha) e ampliado em glicose (4,5 g / L) DMEM contendo 10% de soro fetal bovino, 4 mM L-glutamina, 100 U / ml de penicilina e estreptomicina 100 mg / ml. O H9c2 linha celular de mioblastos é derivada de coração de rato embrionárias, é usada como um modelo in vitro para ambos os músculos esqueléticos e cardíaco 8,9. Prepare 12 placa bem de H9c2 células: <ol><li> Remova o meio de cultura de Petri prato de H9c2 células. </li><li> Lave as células duas vezes com 5 ml de PBS e digerir com 2-3 ml 0,05% tripsina / EDTA. </li><li> Coloque placa de Petri por 5 minutos nos 37 ° C incubadora. </li><li> Inibir a tripsina com 10 ml meio de cultura DMEM. </li><li> Girar as células a 1200 RPM por 8 minutos. </li><li> Depois de retirar o sobrenadante, ressuspender as células em um meio de cultura DMEM ml e contagem de células com hemocitômetro usando Trypan coloração azul.</li><li> Semente H9c2 30.000 células em 2 ml DMEM por bem em uma placa de 12 poços. </li><li> Coloque a placa no 37 ° C incubadora de CO 2 por 24 horas. </li></ol> 2. Isquemia simulada / reperfusão Isquemia / reperfusão foi simulada in vitro através da realização de privação de oxigênio glicose (OGD) em H9c2 culturas de células. Este procedimento foi realizado no palco do microscópio confocal Zeiss com o sistema de incubação de células Pecon (Erbach, Alemanha), permitindo a observação das células durante OGD. <ol><li> Remova o meio por aspiração de 12 placa bem de H9c2 células. </li><li> Lave as células duas vezes com PBS. </li><li> Adicionar 3 ml de glicose livre médio por poço. </li><li> Coloque a placa no sistema de incubação de células. </li><li> Iniciar gás nitrogênio para purgar o oxigênio do sistema de incubação. </li><li> Aguarde até que o nível de oxigênio atinge 0,5%, em seguida, iniciar o temporizador. De oxigênio de 0,5% significa aproximadamente 3 mmHg de tensão parcial. Células sujeitas a uma50 minutos de isquemia simulada. </li><li> No final da isquemia simulada, remova a mídia de glicose livre das células. </li><li> Pipetar 2 ml meio de cultura normal para os poços. </li><li> Coloque a placa de 12 poços por 30 minutos nos 37 ° C incubadora de CO 2, este é o &quot;período de reperfusão&quot;. </li></ol> 3. Preparar resgate células-tronco mesenquimais Medula óssea de origem humana foi levada em T75 frascos e diluídas com meio modificado Dulbecco Águia (DMEM) meio de cultura contendo 10% de soro fetal bovino (FCS), 100 U / ml de penicilina e 100 estreptomicina mcg / ml, 4 mM L-glutamina e 1 g / l de glicose. Os frascos foram incubados a 37 ° C em uma atmosfera totalmente umidificado de 5% de CO 2 para 3 dias. Após o período de incubação, a BMSCs aderidos à superfície dos frascos e os demais componentes da medula óssea foram eliminados por lavagem com PBS. O BMSCs utilizadas foram entre 1 e 5 passagens nos experimentos. A identidade de células foi confirmada pela presença de marcadores de linhagem específica de superfície celular por citometria de fluxo. Marcadores de linhagem hematopoiéticas específicos de superfície (CD34, CD45) e marcadores de superfície mesenquimais (CD73, CD90, CD105 e CD166) foram investigados. Durante a isquemia simulada, preparar resgate de células-tronco mesenquimais para transplante. <ol><li> Diluir o corante fluorescente Vybrant fez em razão de 1:200 em meio de cultura DMEM. </li><li> Aspirar médio das células de resgate e adicionar 300 mL com DMEM Vybrant DiD. </li><li> Prato de Petri lugar por 30 minutos nos 37 ° C incubadora de CO 2. </li><li> Remova o meio de cultura de Petri prato de células-tronco mesenquimais. </li><li> Lave as células duas vezes com 5 ml de PBS e digerir com 2-3 ml 0,05% tripsina / EDTA. </li><li> Coloque placa de Petri por 5 minutos nos 37 ° C incubadora. </li><li> Inibir a tripsina com 10 ml meio de cultura DMEM. </li><li> Girar as células a 1200 RPM por 8 minutos. </li><li> Depois de retirar o supernatant, ressuspender as células em um meio de cultura DMEM ml e contagem de células com hemocitômetro usando Trypan coloração azul. </li><li> Depois de 30 minutos no final da reperfusão adicionar 20.000 células-tronco mesenquimais por bem ao pós-isquêmica H9c2 mioblastos cardíacos. </li><li> Lugar de co-cultura de células para a 37 ° C incubadora de CO 2 por 24 horas. </li></ol> 4. Análise com microscopia confocal Após a lesão de isquemia / reperfusão simulados, as células são incubadas em meio de cultura normal para 24 horas. <ol><li> Após 24 horas de lavagem células duas vezes com PBS. </li><li> Mancha as células em 500 solução vivo / morto mL de corante por 30 minutos (5 nM e 400 nM calceína etídio-homodímero-2 em PBS) (5x10 4 células / ml). </li></ol> A avaliação das imagens confocal para as células vivas e mortas selecionados pela morfologia e de fluorescência pode ser realizada com o software ImageJ (National Institutes of Health, EUA). Em caso de co-culturas, MSCs pode ser distinguido do H9c2 células, devido à sua rotulagem célula Vybrant DiD. A proporção de células mortas pode ser avaliada em 4 campos independentes de vista (objetiva de 10x) para cada cultura de uma forma cega 10. H9c2 cardiomyoblasts cultivadas em lamínulas de vidro 42 mm, podem também ser investigado com o tempo de vídeo microscopia de lapso durante e depois da isquemia / reperfusão usando o sistema de incubação de células do microscópio confocal. Célula a célula-interações como a fusão celular e formação de nanotubos intercelular pode ser estudada ao longo do tempo. 5. A análise por citometria de fluxo Após a lesão de isquemia / reperfusão simulados, as células são incubadas em meio de cultura normal para 24 horas. <ol><li> Após 24 horas, colher os meios de cultura. É muito importante recolher o meio de cultura também, porque algumas células mortas poderiam ter separado da superfície da placa de cultura durante a incubação 24 horasção. </li><li> Lave as células duas vezes com PBS e digerir com 0,05% de tripsina-EDTA. </li><li> Inibir a tripsina com meio de cultura DMEM. </li><li> Girar as células eo meio de cultura colhida em 1200 RPM (aproximadamente 150-200g) por 8 minutos. </li><li> Desprezar o sobrenadante. </li><li> Suspender as células em 500 solução vivo / morto mL de corante por 30 minutos (5 nM e 400 nM calceína etídio-homodímero-2 em PBS) (5x10 4 células / ml). </li><li> Transferência de células para citometria de fluxo de tubos. </li><li> Inicie o software Pro CellQuest. </li><li> Para configurar o citômetro de fluxo para medição, controle de preparar amostras de células vivas e mortas. <ol class="lalpha"><li> Placa H9c2 células a uma densidade de 3x10 4 em 12 placas bem como descrito no ponto 1. </li><li> Prepare viver controles célula com trypsinisation única como descrito no ponto 1. </li><li> Prepare os controles de células mortas através de tratamento com 10 mM H 2 O 2 por 1 hora. </li><li> Depois trypsinisation, resuspend viver e controles de células mortas em 500 mL de solução de corante ao vivo / morto (5 nM calceína-AM e 400 nM de etídio-homodímero-2 em PBS). </li></ol></li><li> As configurações de instrumento deve ser ajustado de modo que as células vivas são calceína positivo e de etídeo homodímero negativo, enquanto as células mortas são calceína negativos e de etídeo homodímero positivo. </li><li> A porcentagem dessas populações pode ser expressa como barras em um gráfico e análise estatística podem ser realizadas sobre esses valores. </li><li> Medir os diferentes grupos experimentais. </li></ol> 6. Resultados representativos: Nossos resultados mostraram que acrescentou células-tronco mesenquimais pode melhorar a sobrevivência de células cardíacas pós-isquêmica. Imagens de microscopia confocal revelou direta célula-célula para interações, como a ligação da membrana parcial ou nanotubos intercelular, o que provavelmente desempenham um papel importante na proteção observada 10. Esses nanotubos decorrerá ao longo de distâncias de várias células diameters, e seus diâmetros foram entre 200 e 500 nm (setas brancas). <img src="/files/ftp_upload/3575/3575fig1.jpg" alt="Figura 1" /> Figura 1. Formação de nanotubos entre as células. Nanotubos de formação (seta branca) foi observada entre cardiomyoblasts Vybrant Dio rotulados e DiD Vybrant rotulados células-tronco mesenquimais. Citometria de fluxo mostraram as populações de sobreviver e cardiomyoblasts necrótico e células-tronco mesenquimais. Curiosamente, também observamos uma terceira, &#39;feridos&#39; população de células que continha cardiomyoblast calceína mas também continha o indicador das células mortas, homodímero de etídio (Figura 2). <img src="/files/ftp_upload/3575/3575fig2.jpg" alt="Figura 2" /> Figura 2. Representante dot-plot dos diferentes populações de células após a isquemia simulada. A avaliação de vários experimentos showed que a adição de células-tronco mesenquimais para cardiomyoblast H9c2 pós-isquêmica aumentou significativamente a percentagem de células vivas em comparação com os mioblastos cardíacos cultivadas somente após a isquemia (Figura 3). <img src="/files/ftp_upload/3575/3575fig3.jpg" alt="Figura 3" /> Figura 3. . Efeito do tratamento com células-tronco em cardiomyoblasts pós-isquêmica Percentagem de células vivas foi significativamente reduzida após isquemia simulada em relação ao controle (controle versus modelo de IR: 90,36 ± 2,60 vs 10,52 ± 0,48, *** p &lt;0,001), que aumentou após a adição de células-tronco mesenquimais (IR modelo vs IR + BMSC: 10,52 ± 0,48 vs 25,21 ± 2,13, *** p &lt;0,001). Os dados representam média ± SEM. Análise estatística dos dados foi realizada utilizando uma forma de análise de variância com pós Tukey de comparações múltiplas hoc teste.

<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>

Não há conflitos de interesse declarados.

O protocolo demonstrado in vitro é uma abordagem para a questão muito mais complexa da terapia com células-tronco em infarto do miocárdio, com todas as vantagens e desvantagens de tal modelo. Obviamente, ele não pode refletir a complexa (imunológica, por exemplo) eventos que ocorrem durante e após infarto do miocárdio, mas pode se concentrar sobre os efeitos diretos das células adicionado nas células pós-isquêmica. Os efeitos da isquemia simulada sobre H9c2 cardiomyoblasts depende muito do tempo de OGD, sobr...

<table border="1"><tbody><tr><td> Nome do reagente </td><td> Companhia </td><td> Número de catálogo </td><td> Comentários </td></tr><tr><td> calceína-AM </td><td> 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 etídio-2 </td><td> Sondas moleculares </td><td> L3224, E3599 </td><td> <a href="http://www.invitrogen.com">http://www.invitrogen.com</a> </td></tr><tr><td> Vybrant DiD </td><td> Sondas moleculares </td><td> V22887 </td><td> <a href="http://www.invitrogen.com">http://www.invitrogen.com</a> </td></tr></tbody></table> Tabela 1. Reagentes. <table border="1"><tbody><tr><td> Nome do equipamento </td><td> Companhia </td><td> Comments (opcional) </td></tr><tr><td> Pecon sistema de incubação de células para microscópios Zeiss </td><td> Pecon GmbH </td><td> <a href="http://www.pecon.biz/">www.pecon.biz/</a> </td></tr></tbody></table> Equipamentos tabela 2..

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

Protocolos de transplante de células-tronco estão encontrando seu caminho na prática clínica 1,2,3. Obter melhores resultados, fazendo com que os protocolos mais robustos, e encontrar novas fontes de células implantáveis ​​são o foco de pesquisas recentes 4,5. Investigar a eficácia de terapias celulares não é uma tarefa fácil e novas ferramentas são necessários para investigar os mecanismos envolvidos no processo de tratamento 6. Nós projetamos um protocolo experimental de isquemia / reperfusão, a fim de permitir a observação de conexões celulares e mecanismos subcelulares mesmo durante a isquemia / reperfusão e após o transplante de células-tronco e para avaliar a eficácia da terapia celular. H9c2 cardiomyoblast células foram colocadas em placas de cultura de células 7,8. Isquemia foi simulado com 150 minutos em um meio de glicose livre com nível de oxigênio abaixo de 0,5%. Então, a mídia normal e os níveis de oxigênio foram reintroduzidos para simular reperfusão. Após a privação de glicose oxigênio,as células danificadas foram tratados com transplante de medula óssea humana rotulados derivados de células-tronco mesenquimais, adicionando-os à cultura. Células-tronco mesenquimais são as preferidas em ensaios clínicos, porque eles são facilmente acessíveis com cirurgia minimamente invasiva, facilmente expansível e autólogo. Após 24 horas de co-cultivo, as células foram coradas com calceína e de etídeo-homodímero de diferenciar entre células vivas e mortas. Esta configuração permitiu investigar as conexões intercelulares por microscopia de fluorescência confocal e quantificar a taxa de sobrevivência de células pós-isquêmica por citometria de fluxo. Microscopia confocal mostrou as interações das duas populações de células, tais como fusão celular e formação de nanotubos intercelular. Citometria de fluxo revelou três grupos de células danificadas que podem ser plotados em um gráfico e analisados ​​estatisticamente. Essas populações podem ser investigados separadamente e conclusões podem ser tiradas destes dados sobre a eficácia do simuladoabordagem terapêutica.

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

Demonstramos como configurar um<em&gt; In vitro</em&gt; Isquemia / reperfusão modelo e como avaliar o efeito da terapia com células-tronco em células cardíacas pós-isquêmica.

Transplante de Células-tronco em um In vitro Modelo de isquemia / reperfusão Simulated

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

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Medicine

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

14.0K visualizações.  Semmelweis University. Demonstramos como configurar um In vitro Isquemia / reperfusão modelo e como avaliar o efeito da terapia com células-tronco em células cardíacas pós-isquêmica.

Vídeo: 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

Um modelo do rato de No Utero Transplante

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

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 Quantitative PCR em tempo real para determinar enxerto célula dadora num modelo murino de osso Competitiva Marrow Transplantation

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.

Isquemia-reperfusão modelo de lesão renal aguda e Pós Lesão fibrose em camundongos

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 Stem Cell Transplantation em Experimental contusão 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 ...

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.

Oxigênio-Glucose Privação e reoxigenação como um<em&gt; In Vitro</em&gt; Isquemia e reperfusão Lesão modelo para estudar Disfunção Barreira 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.

Estudar o cancro do pâncreas Stem características celulares para desenvolver estratégias Novo tratamento

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-reperfusão

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.

Criação e transplante de uma folha de células-tronco adiposo-derivado (ASC) em um modelo de cicatrização de feridas 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.

Modelo de Mouse de dois vasos oclusão de isquémia-reperfusão 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.

Um modelo pré-clínico do rato para o estudo da lesão da Isquemia-reperfusion na microcirurgia reconstrutiva

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