This work was supported by a Pilot and Feasibility Grants from the Indiana University School of Medicine Center (IUSM) for Excellence in Molecular Hematology (NIDDK, 5P30DK090948). Additional funding was provided by a Biomedical Enhancement Grant from IUSM. We would like to thank Dr. Karen Cowden Dahl for commenting on the manuscript.

1. embrioides Corporal (EB) Formação <ol><li> Gelatina-se adaptar CES que foram mantidos em fibroblastos de embrião de ratinho (MEFs). CES passagem 3 vezes na placa de 6 poços de cultura de tecidos revestidas com gelatina a 0,1% para remover MEFs. <ol><li> Cultivar células em meio de manutenção com LIF ESC para manter as células indiferenciadas (Tabela 1). Faça células certeza nunca superior a 80% de confluência. Use baixa passagem (10 ou menos passagens após a remoção de MEFs) células de diferenciação. </li></ol></li><li> No dia antes da CES são cultivadas durante a diferenciação EB, a passagem das células, de forma que será de aproximadamente 50-70% confluentes no dia seguinte. Continuar a cultura de células em meio de manutenção de ESC para reter pluripotência das células. </li><li> No dia da diferenciação, meios de manutenção aspirado ESC e lava-se com 1 ml de fosfato salino tamponado (PBS: NaCl 137 mM, KCl 2,7 mM e 11,9 mM de tampão fosfato, pH 7,4) por poço de uma placa de 6 poços. <ol><li> Adicionar 200 ul de 0,25% Trypsem / EDTA a cada poço e incuba-se a 37 ° C durante 3 min. </li><li> Inactivar a tripsina / EDTA com 800 ul de meios de diferenciação. Pipeta cima e para baixo em um 2 ml pipeta sorológica com uma ponta p200 para quebrar-se as células em uma suspensão de células individuais. Certifique-se de que a ponta p200 se encaixa perfeitamente no final, para a mídia não subir entre a pipeta e interface de ponta. </li><li> Pipeta cima e para baixo cerca de 5-10 vezes. Tome cuidado para não criar bolhas durante a pipetagem. </li></ol></li><li> Transferência de células para um tubo cônico de 15 ml. Traga-se o volume para 10 ml com PBS. Centrifugar a 315 xg durante 5 min à temperatura ambiente. </li><li> Remover o sobrenadante. Lavar duas vezes com 5 ml de PBS para remover a mídia restantes contendo LIF. Centrifuga-se como no passo 1.4 para cada lavagem. <ol><li> Ressuspender o sedimento final de células em 2 ml de meio de diferenciação (Tabela 2). </li></ol></li><li> Contar as células com um hemocitómetro ou contador de células e a placa 6.000-10.000 células / ml numa placa de 10 centímetros de Petri(Cultura de tecido não-tratado). <ol><li> Determine as exatas células / ml empiricamente para cada linha ESC. Use placas de Petri estéreis normalmente utilizados para o trabalho bacteriana ou placas de baixa adesão. NOTA: Para obter os melhores resultados de diferenciação, as EBs devem formar esferas que permanecem em suspensão sem anexar a placa. Teste várias marcas de placas para encontrar aquelas com menos aderência. </li><li> Incubar os CES diferenciadores em um 37 ° C tecido cultura incubadora com 5% de CO 2. </li></ol></li></ol><table border="0" cellpadding="0" cellspacing="0"><colgroup><col /><col span="2" /><col /><col /><col /></colgroup><tbody><tr><td> Reagente </td><td> Banco </td><td> Concentração final </td><td> Volume </td><td> Empresa </td><td> Número de Catálogo </td></tr><tr><td> DMEM </td><td> 1x </td><td></td><td> 410 ml </td><td> S<html> IGMA / Aldrich </td><td> D5796 </td></tr><tr><td> FBS (ES filtrada) </td><td> 100% </td><td> 15% </td><td> 75 ml </td><td> Hyclone </td><td> SH30070.03E </td></tr><tr><td> Não-essencial Aminoácidos </td><td> 100x </td><td> 1x </td><td> 5 ml </td><td> Life Technologies </td><td> 11140 </td></tr><tr><td> L-Glutamina </td><td> 100x </td><td> 1x </td><td> 5 ml </td><td> Life Technologies </td><td> 35050 </td></tr><tr><td> Penncillin / Estreptomicina </td><td> 100x </td><td> 1x </td><td> 5 ml </td><td> Life Technologies </td><td> 15070 </td></tr><tr><td> β-mercaptoetanol </td><td> 14,3 M </td><td> 114 mM </td><td> 4 l </td><td> Sigma / Aldrich </td><td> M3148 </td></tr><tr><td> Fator Inibidor de Leucemia (LIF) </td><td> 10 7 unidades / ml </td><td> 1000 unidades / ml </td><td> 50 ul </td><td> Millipore </td><td> ESG1107 </td></tr></tbody></table>ONTEÚDO &quot;&gt; Tabela 1: ESC Manutenção Media. <table border="0" cellpadding="0" cellspacing="0"><colgroup><col /><col span="2" /><col /><col span="2" /></colgroup><tbody><tr><td> Reagente </td><td> Banco </td><td> Concentração final </td><td> Volume </td><td> Empresa </td><td> Número de Catálogo </td></tr><tr><td> DMEM </td><td> 1x </td><td></td><td> 410 ml </td><td> Sigma / Aldrich </td><td> D5796 </td></tr><tr><td> FBS (User selecionados para diferenciação ideal) </td><td> 100% </td><td> 15% </td><td> 75 ml </td><td> Hyclone </td><td> SH30070.03E </td></tr><tr><td> Não-essencial Aminoácidos </td><td> 100x </td><td> 1x </td><td> 5 ml </td><td> Life Technologies </td><td> 11140 </td></tr><tr><td> L-Glutamina </td><td> 100x </td><td> 1x </td><td> 5 ml </td><td> Vida Tecnologia degias </td><td> 35050 </td></tr><tr><td> Penncillin / Estreptomicina </td><td> 100x </td><td> 1x </td><td> 5 ml </td><td> Life Technologies </td><td> 15070 </td></tr><tr><td> β-mercaptoetanol </td><td> 14,3 M </td><td> 114 mM </td><td> 4 l </td><td> Sigma / Aldrich </td><td> M3148 </td></tr></tbody></table> Tabela 2: Diferenciação Media. 2. preparação de células EB à infecção pelo Vírus <ol><li> Na fase de desenvolvimento desejado (entre o dia 2 e dia 3), transfira as EBs do 10 centímetros de Petri para tubo de 15 ml. Lava-se a placa com 5 ml de PBS e adicionar a lavagem para o tubo cónico. </li><li> Agregar as CEs a 315 xg à temperatura ambiente durante 5 min. Lave as células EB com 5 ml de PBS. </li><li> Adicionar 1 ml de solução de separação de células descongelado (contendo enzimas proteolíticas e colagenolíticas) e colocar os tubos num banho de água a 37 C ° (incubadora) ou durante 30 minutos com occagitação asional (a partir de um movimento súbito ou luz vórtice). </li><li> Adicionar 1 ml de mídia diferenciação. Pipeta cima e para baixo com uma pipeta 2 ml com uma ponta de pipeta p200. Colocar o tubo em banho-maria a 37 ° C de novo durante 30-60 minutos. </li><li> Girar as células a 315 xg durante 5 min e lava-se as células com PBS. </li></ol> Infecção 3 Vírus <ol><li> Ressuspender as células em 1,5 ml de meio de diferenciação. Transferência da suspensão de células para uma de 6 poços de cultura de tecidos não-placa tratada. </li><li> Prepare a retrovírus por técnicas convencionais antes do tempo. Adicionar 5 a 100 mL de sobrenadante virai para células dependendo título viral. Não adicione polibrene para melhorar a infecção, pois isso inibe a reforma posterior da EBS. </li><li> Spinoculate as células com o vírus por centrifugação a 2120 xg durante 90 min à temperatura ambiente. </li></ol> 4. Diferenciando virais células EB infectados em gotas de suspensão <ol><li> Adicionar 2 ml de meio de diferenciação em cada poço de infected EB suspensão de células. </li><li> Pipetar 3,5 ml de suspensão de células infectadas em EB um reservatório de reagente estéril para multipipettors. Utilizar a pipeta de multipipettor 15-20 filas de oito 20 ul gotas sobre a tampa invertida da placa de Petri 15 centímetros. </li><li> Adicionar 10 ml de PBS estéril ou água para a metade inferior da placa de Petri. Em seguida, inverter a tampa com as gotas e coloque sobre a placa de Petri. Certifique-se de que as gotas estão pendurados de cabeça para baixo a partir da tampa com PBS ou água abaixo para manter a câmara úmida. </li><li> Coloque os pratos no 37 ° C tecido cultura incubadora com 5,0% de CO 2. </li><li> Após 2 dias, recolher EB formadas na suspensão, invertendo a tampa cai e lavagem com 4,5 mL de meios de diferenciação. <ol><li> Transferência de Mídia e EBS para uma nova cultura 10 centímetros não-tecido placa de Petri. Lava-se a tampa, uma vez mais com 3 ml de meio de diferenciação e de transferência para a placa de 10 cm. </li></ol></li><li> Células colheita para análise por citometria de fluxo depois de um total de 8dias de cultura a partir da transferência inicial de células de mídia diferenciação (-LIF). </li></ol> 5. As células que se preparam para Análise de Fluxo Cytometer <ol><li> Transferir as células para um tubo de 15 ml com uma pipeta de 10 ml. Lava-se a placa com 5 ml de PBS e transferir para o mesmo tubo cónico. </li><li> Células de pellets em 315 x g. Lave pellets com 10 ml PBS. </li><li> Adicionar 1 ml de solução de separação de células descongelada e colocar os tubos num banho de água a 37 C ° durante 30 min, com agitação ocasional. Para a detecção de alguns antigénios de superfície celular, a tripsina pode ser usado em substituição. </li><li> Adicionar 1 ml de mídia de diferenciação e pipeta cima e para baixo com uma pipeta de 2 ml. Utilizar uma ponta de p200 para a ponta da pipeta para ajudar a quebrar-se digerido EB em suspensão de célula única. <ol><li> Colocar o tubo num banho de água a 37 ° C de novo durante 60 minutos a fim de que as proteínas de membrana integrais para reciclar para a superfície da célula. </li></ol></li><li> Sedimentar as células a 315 xg durante 5 min. </li><li> Lave o wi célulasth 0,1% Albumina de soro bovino Fracção V (BSA) preparada em PBS (PBS / BSA) e incuba-se as células com anticorpos específicos fluorescente etiquetado. </li></ol> 6 Análise do Fluxo Citometria de Progenitores hematopoiéticos <ol><li> Colocam-se 10 6 células EB derivados em 5 ml 12 x 75 mm redondo tubo inferior. Para ajustar as definições de compensação citômetro de fluxo, use esferas de compensação de acordo com as instruções do fabricante. </li><li> Células de pellets em 315 x g. Decantar o sobrenadante e ressuspender o pellet em solução de PBS / BSA residual no tubo. </li><li> Para detectar ESC HPCs, incubar as células com anticorpos fluorescentes rotulado: anti-rato CD41-PE (R-Phycoerytherin) e anti rato-CD117 (c-kit) -APC / Cy7 (aloficocianina Cyanine 7). <ol><li> Dilui-se os anticorpos 1: 100 em PBS / BSA. Adicionar 100 ul de anticorpo diluído em cada amostra. Determine a diluição correta de anticorpos para cada fornecedor, clone, e muito ou anticorpo. Determinar a diluição óptima para a marcação de células individualmente. </li&gt; </ol></li><li> Incubar as amostras em gelo no escuro durante 30 min. </li><li> Adicionar 2 ml de células de PBS / BSA e pelotas a 315 xg durante 5 min. </li><li> Aspirar o sobrenadante e pellet ressuspender em 300 mL de PBS ou outro tampão isotônica. </li><li> Filtrar ressuspensas células através de um coador de células tampão (0,35 M) para remover grandes agregados celulares. </li><li> Analise as células em um citômetro de fluxo. </li></ol>

<ol>
	<li>Williams, R. L., 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=Myeloid+leukaemia+inhibitory+factor+maintains+the+developmental+potential+of+embryonic+stem+cells.">Myeloid leukaemia inhibitory factor maintains the developmental potential of embryonic stem cells.</a> Nature. 336, 684-687 (1988).</li><li>Desbaillets, I., Ziegler, U., Groscurth, P., Gassmann, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Embryoid+bodies:+an+in+vitro+model+of+mouse+embryogenesis.">Embryoid bodies: an in vitro model of mouse embryogenesis.</a> Experimental physiology. 85, 645-651 (2000).</li><li>Hopfl, G., Gassmann, M., Desbaillets, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differentiating+embryonic+stem+cells+into+embryoid+bodies.">Differentiating embryonic stem cells into embryoid bodies.</a> Methods Mol Biol. 254, 79-98 (2004).</li><li>Tian, X., Kaufman, D. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differentiation+of+embryonic+stem+cells+towards+hematopoietic+cells:+progress+and+pitfalls.">Differentiation of embryonic stem cells towards hematopoietic cells: progress and pitfalls.</a> Curr Opin Hematol. 15, 312-318 (2008).</li><li>Thomas, K. R., Capecchi, 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=Site-directed+mutagenesis+by+gene+targeting+in+mouse+embryo-derived+stem+cells.">Site-directed mutagenesis by gene targeting in mouse embryo-derived stem cells.</a> Cell. 51, 503-512 (1987).</li><li>Mansour, S. L., Thomas, K. R., Capecchi, 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=Disruption+of+the+proto-oncogene+int-2+in+mouse+embryo-derived+stem+cells:+a+general+strategy+for+targeting+mutations+to+non-selectable+genes.">Disruption of the proto-oncogene int-2 in mouse embryo-derived stem cells: a general strategy for targeting mutations to non-selectable genes.</a> Nature. 336, 348-352 (1988).</li><li>Robertson, E., Bradley, A., Kuehn, M., Evans, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Germ-line+transmission+of+genes+introduced+into+cultured+pluripotential+cells+by+retroviral+vector.">Germ-line transmission of genes introduced into cultured pluripotential cells by retroviral vector.</a> Nature. 323, 445-448 (1986).</li><li>Cherry, S. R., Biniszkiewicz, D., van Parijs, L., Baltimore, D., Jaenisch, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Retroviral+expression+in+embryonic+stem+cells+and+hematopoietic+stem+cells.">Retroviral expression in embryonic stem cells and hematopoietic stem cells.</a> Mol Cell Biol. 20, 7419-7426 (2000).</li><li>Pfeifer, A., Ikawa, M., Dayn, Y., Verma, I. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transgenesis+by+lentiviral+vectors:+lack+of+gene+silencing+in+mammalian+embryonic+stem+cells+and+preimplantation+embryos.">Transgenesis by lentiviral vectors: lack of gene silencing in mammalian embryonic stem cells and preimplantation embryos.</a> Proc Natl Acad Sci U S A. 99, 2140-2145 (2002).</li><li>Smith-Arica, J. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Infection+efficiency+of+human+and+mouse+embryonic+stem+cells+using+adenoviral+and+adeno-associated+viral+vectors.">Infection efficiency of human and mouse embryonic stem cells using adenoviral and adeno-associated viral vectors.</a> Cloning and stem cells. 5, 51-62 (2003).</li><li>Lakshmipathy, 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=Efficient+transfection+of+embryonic+and+adult+stem+cells.">Efficient transfection of embryonic and adult stem cells.</a> Stem Cells. 22, 531-543 (2004).</li><li>Cook, B. D., Liu, S., Evans, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Smad1+signaling+restricts+hematopoietic+potential+after+promoting+hemangioblast+commitment.">Smad1 signaling restricts hematopoietic potential after promoting hemangioblast commitment.</a> Blood. 117, 6489-6497 (2011).</li><li>Zafonte, B. T., 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=Smad1+expands+the+hemangioblast+population+within+a+limited+developmental+window.">Smad1 expands the hemangioblast population within a limited developmental window.</a> Blood. 109, 516-523 (2007).</li><li>Kyba, M., Perlingeiro, R. C., Daley, G. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=HoxB4+confers+definitive+lymphoid-myeloid+engraftment+potential+on+embryonic+stem+cell+and+yolk+sac+hematopoietic+progenitors.">HoxB4 confers definitive lymphoid-myeloid engraftment potential on embryonic stem cell and yolk sac hematopoietic progenitors.</a> Cell. 109, 29-37 (2002).</li><li>Galvin, K. E., Travis, E. D., Yee, D., Magnuson, T., Vivian, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nodal+signaling+regulates+the+bone+morphogenic+protein+pluripotency+pathway+in+mouse+embryonic+stem+cells.">Nodal signaling regulates the bone morphogenic protein pluripotency pathway in mouse embryonic stem cells.</a> J Biol Chem. 285, 19747-19756 (2010).</li><li>Ismailoglu, I., Yeamans, G., Daley, G. Q., Perlingeiro, R. C., Kyba, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mesodermal+patterning+activity+of+SCL.">Mesodermal patterning activity of SCL.</a> Exp Hematol. 36, 1593-1603 (2008).</li><li>Kyba, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enhanced+hematopoietic+differentiation+of+embryonic+stem+cells+conditionally+expressing+Stat5.">Enhanced hematopoietic differentiation of embryonic stem cells conditionally expressing Stat5.</a> Proc Natl Acad Sci U S A. 100, 11904-11910 (2003).</li><li>Cao, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MiR-23a+regulates+TGF-beta-induced+epithelial-mesenchymal+transition+by+targeting+E-cadherin+in+lung+cancer+cells.">MiR-23a regulates TGF-beta-induced epithelial-mesenchymal transition by targeting E-cadherin in lung cancer cells.</a> Int J Oncol. 41, 869-875 (2012).</li><li>Chan, M. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+basis+for+antagonism+between+PDGF+and+the+TGFbeta+family+of+signalling+pathways+by+control+of+miR-24+expression.">Molecular basis for antagonism between PDGF and the TGFbeta family of signalling pathways by control of miR-24 expression.</a> EMBO J. 29, 559-573 (2010).</li><li>Huang, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Upregulation+of+miR-23a+approximately+27a+approximately+24+decreases+transforming+growth+factor-beta-induced+tumor-suppressive+activities+in+human+hepatocellular+carcinoma+cells.">Upregulation of miR-23a approximately 27a approximately 24 decreases transforming growth factor-beta-induced tumor-suppressive activities in human hepatocellular carcinoma cells.</a> Int J Cancer. 123, (2008).</li><li>Min, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=TGF-beta-associated+miR-27a+inhibits+dendritic+cell-mediated+differentiation+of+Th1+and+Th17+cells+by+TAB3,+p38+MAPK,+MAP2K4+and+MAP2K7.">TGF-beta-associated miR-27a inhibits dendritic cell-mediated differentiation of Th1 and Th17 cells by TAB3, p38 MAPK, MAP2K4 and MAP2K7.</a> Genes Immun. 13, 621-631 (2012).</li><li>Mikkola, H. K., Fujiwara, Y., Schlaeger, T. M., Traver, D., Orkin, S. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expression+of+CD41+marks+the+initiation+of+definitive+hematopoiesis+in+the+mouse+embryo.">Expression of CD41 marks the initiation of definitive hematopoiesis in the mouse embryo.</a> Blood. 101, 508-516 (2003).</li><li>Mitjavila-Garcia, M. T., 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=Expression+of+CD41+on+hematopoietic+progenitors+derived+from+embryonic+hematopoietic+cells.">Expression of CD41 on hematopoietic progenitors derived from embryonic hematopoietic cells.</a> Development. 129, 2003-2013 (2002).</li><li>Warr, M. R., Pietras, E. M., Passegue, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanisms+controlling+hematopoietic+stem+cell+functions+during+normal+hematopoiesis+and+hematological+malignancies.+Wiley+interdisciplinary+reviews.">Mechanisms controlling hematopoietic stem cell functions during normal hematopoiesis and hematological malignancies. Wiley interdisciplinary reviews.</a> Systems biology and medicine. 3, 681-701 (2011).</li><li>Dahl, R., Ramirez-Bergeron, D. L., Rao, S., Simon, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spi-B+can+functionally+replace+PU.1+in+myeloid+but+not+lymphoid+development.">Spi-B can functionally replace PU.1 in myeloid but not lymphoid development.</a> Embo J. 21, 2220-2230 (2002).</li><li>Dahl, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+of+macrophage+and+neutrophil+cell+fates+by+the+PU.1:C/EBPalpha+ratio+and+granulocyte+colony-stimulating+factor.">Regulation of macrophage and neutrophil cell fates by the PU.1:C/EBPalpha ratio and granulocyte colony-stimulating factor.</a> Nat Immunol. 4, 1029-1036 (2003).</li></ol>

Os autores não têm interesses financeiros competitivos para divulgar.

Como discutido acima, os clones do CES por indução que expressam um gene de interesse pode ser gerada usando sistemas de doxiciclina, no entanto, a geração destas linhas é demorado e trabalhoso. Descrito no presente protocolo é um método de expressar um gene de interesse em suspensão de células individuais preparados a partir de derivados CES CEs. Estas células infectadas são então reformada em EBs por enforcamento queda para examinar diferenciação subseqüente. No exemplo (Figura 3), é m...

Murine embryonic stem cells (ESCs) are pluripotent, remaining undifferentiated and self-renewing in the presence of the cytokine Leukemia Inhibitory Factor (LIF)1. Upon withdrawal of LIF they will spontaneously differentiate into 3-dimensional (3D) structures called embryoid bodies (EBs)2. The 3D architecture allows for the development of the three germ layers ectoderm, endoderm, and mesoderm, which then later give rise to mature tissue types3. ESCs are an exceptional model for elucidating the molecular mechanisms of cellular differentiation, particularly the investigation of the development of early hematopoietic progenitor cells (HPCs)4. 
Gene expression in ESCs can be manipulated by several techniques that allow for the determination of a role for individual molecules in development. One of the most common techniques is to use homologous recombination to generate ESC lines, which lack a gene of interest5,6. There are also a number of techniques that have been used to overexpress genes. The first technique used to modify gene expression in ESCs was to infect them with recombinant retroviruses7,8. The gene of interest however is often silenced as the ESCs differentiate into progenitor and mature cell types. Use of lentiviruses has been successful in limiting the silencing of virally expressed genes9. Other viral vectors used for overexpression include adenovirus and adeno-associated virus10. In addition standard transfection techniques to stably introduce expression plasmids are widely used for ESC transgene expression11. One difficulty with these systems is that often expression of a specific gene has different effects depending on its temporal expression. For example, the Smad1 protein affects the development of hematopoietic cells differently during different stages of EB development12,13. 
This problem can be circumvented by the generation of ESCs that inducibly express a gene of interest. The most common system for inducibly expressing transgenes in ESCs uses the tetracycline resistance operon from E. Coli (Escherichia coli). Several different tetracycline systems have been developed. One of the more popular strategies was developed by Kyba and colleagues14. They generated an ESC line (Ainv15), which has the reverse tetracycline transactivator gene inserted into the constitutively active ROSA26 locus. A tetracycline response element (TRE), a downstream LoxP site (locus of X-over P1 from bacteriophage P1), and a promoterless neomycin cassette were introduced into the HPRT (Hypoxanthine-guanine phosphoribosyltransferase) locus on the X chromosome. Using a CRE recombination approach a gene of interest along with a eukaryotic promoter to drive the expression of the neomycin resistance gene can be inserted into the LoxP site. Correctly targeted ESCs are isolated by G418 selection. These targeted clones then must be tested for doxycycline (or tetracycline) inducible expression of the transgene. This approach has successfully generated ESC lines that inducibly express HoxB4, Stat5, SCL, and Smad714-17. However, generation of these inducible cell lines is time consuming. Described here is a method to disaggregate ESC-derived embryoid bodies (EBs) into single cell suspensions, retrovirally infect the cell suspensions at different days of development, and then reform the EBs by hanging drop. Downstream differentiation is later evaluated by flow cytometry. In this article an example of how miRNA expression in EB-derived cells effects hematopoietic differentiation is shown. This method is useful for investigating the role of genes after specific germ layer tissue is derived.

<table border="0" cellpadding="0" cellspacing="0" width="470">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:193px;">Reagent</td>
			<td style="width:144px;">Company</td>
			<td style="width:133px;">Catalog Number</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:193px;">DMEM</td>
			<td style="width:144px;">Sigma/ Aldrich</td>
			<td style="width:133px;">D5796</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:193px;">b-mercaptoethanol</td>
			<td style="width:144px;">Sigma/ Aldrich</td>
			<td style="width:133px;">M3148</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:193px;">FBS (ES Screened)</td>
			<td style="width:144px;">Hyclone</td>
			<td style="width:133px;">SH30070.03E</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:193px;">FBS (Defined)</td>
			<td style="width:144px;">Hyclone</td>
			<td style="width:133px;">SH30070.03</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:193px;">Non-Essential Amino Acids</td>
			<td style="width:144px;">Life Technologies</td>
			<td style="width:133px;">11140</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:193px;">L-Glutamine</td>
			<td style="width:144px;">Life Technologies</td>
			<td style="width:133px;">35050</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:193px;">Penn/Strep</td>
			<td style="width:144px;">Life Technologies</td>
			<td style="width:133px;">15070</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:193px;">Trypsin/EDTA</td>
			<td style="width:144px;">Life Technologies</td>
			<td style="width:133px;">25200</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:193px;">LIF ESGRO</td>
			<td style="width:144px;">Millipore</td>
			<td style="width:133px;">ESG1107</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:193px;">ACCUMAX</td>
			<td style="width:144px;">Millipore</td>
			<td style="width:133px;">SCR006</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:193px;">Trypsin/EDTA</td>
			<td style="width:144px;">Life Technologies</td>
			<td style="width:133px;">25200</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:193px;">Falcon Tissue Culture Plates 6-well</td>
			<td style="width:144px;">Fisher Scientific</td>
			<td style="width:133px;">08-772-1B</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:193px;">Falcon Non-treated Plates 6-well</td>
			<td style="width:144px;">Fisher Scientific</td>
			<td style="width:133px;">08-772-49</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:193px;">Falcon Petri dish 10cm</td>
			<td style="width:144px;">Fisher Scientific</td>
			<td style="width:133px;">08-757-100D</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:193px;">Falcon Petri dish 15cm</td>
			<td style="width:144px;">Fisher Scientific</td>
			<td style="width:133px;">08-757-148</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:193px;">Falcon Tube 5mls</td>
			<td style="width:144px;">Fisher Scientific</td>
			<td style="width:133px;">14-959-11A</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:193px;">Falcon Tube 5mls with Cell Strainer Cap</td>
			<td style="width:144px;">Fisher Scientific</td>
			<td style="width:133px;">08-771-23</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:193px;">White sterile resevoirs</td>
			<td style="width:144px;">U.S.A. Scientific</td>
			<td style="width:133px;">111-0700</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:193px;">Rat anti-mouse CD41 PE-conjugated</td>
			<td style="width:144px;">Biolegend</td>
			<td style="width:133px;">133906</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:193px;">Rat anti-mouse CD117 APC/CY7-conjugated</td>
			<td style="width:144px;">Biolegend</td>
			<td style="width:133px;">105826</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:193px;">RW4 ESCs</td>
			<td style="width:144px;">ATCC</td>
			<td>CRL-12418</td>
		</tr>
	</tbody>
</table>

retroviral infection of murine embryonic stem cell derived embryoid body cells for analysis of hematopoietic differentiation

Embryonic stem cells (ESCs) are an outstanding model for elucidating the molecular mechanisms of cellular differentiation. They are especially useful for investigating the development of early hematopoietic progenitor cells (HPCs). Gene expression in ESCs can be manipulated by several techniques that allow the role for individual molecules in development to be determined. One difficulty is that expression of specific genes often has different phenotypic effects dependent on their temporal expression. This problem can be circumvented by the generation of ESCs that inducibly express a gene of interest using technology such as the doxycycline-inducible transgene system. However, generation of these inducible cell lines is costly and time consuming. Described here is a method for disaggregating ESC-derived embryoid bodies (EBs) into single cell suspensions, retrovirally infecting the cell suspensions, and then reforming the EBs by hanging drop. Downstream differentiation is then evaluated by flow cytometry. Using this protocol, it was demonstrated that exogenous expression of a microRNA gene at the beginning of ESC differentiation blocks HPC generation. However, when expressed in EB derived cells after nascent mesoderm is produced, the microRNA gene enhances hematopoietic differentiation. This method is useful for investigating the role of genes after specific germ layer tissue is derived.

Nestes estudos gelatinizadas RW4 (derivado de 129X1 / SvJ rato tensão) CES foram utilizados. EB foram isolados em 3 dias de diferenciação. Para melhores resultados, os CEs deve ser de forma esférica e não aderentes (Figura 1A, B). Após spinoculation com vírus que co-expressam a GFP marcador fluorescente, juntamente com um gene de interesse, EB foram reformada pelo método de gota suspensa. EB foram reformados com sucesso a partir de suspensões de células preparadas a partir de 2,0, 2,5 e 3,0 di...

Watch this Scientific Journal Video about Retroviral Infection of Murine Embryonic Stem Cell Derived Embryoid Body Cells for Analysis of Hematopoietic Differentiation at JoVE.com

Retroviral Infection of Murine Embryonic Stem Cell Derived Embryoid Body Cells for Analysis of Hematopoietic Differentiation

Manipulating temporal gene expression in differentiating embryonic stem cells (ESCs) can be achieved using inducible gene systems. However, generation of these cell lines is costly and time consuming. This protocol achieves rapid expression of a transgene in differentiating ES-derived cells and subsequent analysis of downstream hematopoietic differentiation.

Retroviral Infecção murina Embryonic Stem Cell Derived Cells embrioides corpo de Análise da diferenciação hematopoética

Embryonic stem cells (ESCs) are an outstanding model for elucidating the molecular mechanisms of cellular differentiation. They are especially useful for ...

retroviral-infection-murine-embryonic-stem-cell-derived-embryoid-body

Research

JoVE Journal

Biology

8.4K visualizações.  Harper Cancer Research Institute. Manipulating temporal gene expression in differentiating embryonic stem cells (ESCs) can be achieved using inducible gene systems. However, generation of these cell lines is costly and time consuming. This protocol achieves rapid expression of a transgene in differentiating ES-derived cells and subsequent analysis of downstream hematopoietic differentiation. 