Diferenciação de células-tronco embrionárias <ol><li> Coletar um frasco perto confluentes de células-tronco embrionárias (ESC), através de tratamento com tripsina ESC. </li><li> Ressuspender as células em 5 mL de mídia Diferenciação e transferir para um T25 não-revestido de gelatina. Incubar a 37 ° C por 45 minutos. Recuperar o sobrenadante e coletar células através de centrifugação. Nota: fibroblastos de rato embrionárias (MEFs) das culturas ESC anexar prontamente aos T25 não-revestido de gelatina e, portanto, estão esgotados a partir da cultura durante esta etapa de galvanização. Se você não é o seu cultivo em MEFs ESC, você pode pular a placa pré-. </li><li> Ressuspender MEF-esgotados ESC na mídia Diferenciação em 333.333 mL cells/50. Esta concentração resulta em 100 mL ESC/15. </li><li> Usando multi-canal de pipetador, placa ESC a 100 mL cells/15 queda em 15 cm 2 placas de petri. Com uma pipeta de 8 canais, você deve ser capaz de caber aproximadamente 18-22 fileiras de gotas por placa (cerca de 5 ml por placa). Nota: Para este protocolo, 2-5 15 cm 2 pratos de gotas será mais do que suficiente e deve render 2-5 x 10 6 de seis dias EB células derivadas. </li><li> Suavemente virar placas para inverter gotas. Incubar a 37 ° C 5% CO 2 por 48 horas. </li><li> Piscina cai rodando suavemente placas e transferir para tubo de 15 mL cônico. Enxaguar pratos com 4-6 mL de PBS e adicionar à mesma 15 mL cônico. Nota: Você pode piscina até cinco placas de gota em suspensão. O EBS vai crescer à medida que continuam a diferenciar e se eles são muito concentrados tendem a formar grumos grandes. </li><li> Permitir EBs agrupados para resolver pela força da gravidade (cerca de 10 minutos). Aspirar o sobrenadante sem perturbar EBs. Delicadamente ressuspender em 10 mL de mídia Diferenciação e transferência a 10 cm da placa de petri não-aderente. </li><li> Colocar a placa de petri na placa shaker a 50 rpm e incubar a 37 ° C 5% CO 2. </li><li> 24 horas depois (dia quatro de diferenciação), placas de turbulência para se concentrar EBs no centro da placa de Petri. Cuidadosamente troca de 50% dos meios de comunicação (5 mL) com 5 mL de mídia Diferenciação fresco. Retorno placa para incubadora por mais dois dias. </li></ol> EB dissociação e infecção com MSCV-HoxB4-IRES-GFP <ol><li> No dia seis de diferenciação, a transferência de EBs a 15 mL do tubo cônico. Deixa-se repousar por gravidade. </li><li> Aspirar mídia e ressuspender em 10 mL PBS. Permitir EBs para reassentar pela gravidade. Aspirar PBS. </li><li> Adicionar 250 mL mix enzima dissociação e 1 mL de PBS. Incubar em banho-maria 37 ° C por 20 minutos, ocasionalmente turbilhão tubo para misturar enzimas e EBs. </li><li> Adicionar 8 mL da enzima livre de buffer de dissociação. </li><li> Triturar a mistura usando pipeta de 5 ml até EBs são totalmente dissociados (cerca de 10 vezes; pipetagem excessiva aumentará a morte dentro do EB derivados preparação celular). <ol><li> Mistura será nublado com células como dissociar EBs. </li><li> Colocando a ponteira contra a parte inferior do tubo cônico durante a trituração vai criar uma força de cisalhamento que vai facilitar muito a dissociação. </li></ol></li><li> Coletar células através de centrifugação. </li><li> Ressuspender EB células derivadas em 5 mL de IMDM 10% e contagem usando trypan exclusão azul Nota: Entre quatro dias e seis dias de diferenciação, EBs cavitar o que resulta em uma grande quantidade de apoptose e death.Thus celular, no sexto dia, mais de 30% da EB células derivadas pode manchar com azul de tripano. </li><li> Ressuspender as células EB-derivados de 100.000 células / 2 mL de 10% IMDM + sobrenadante viral de tal forma que um MOI de 5-10 é achieved.Add sulfato de protamina para uma concentração final de 8 mg / mL. Nota: Prepare o suficiente EB / mix sobrenadante viral ao prato quatro chapas 6-bem (assumindo que 2 mL / poço). </li><li> Placa de 2 mL EB / mix sobrenadante viral por poço de quatro 6 placas bem pré-revestida com OP9 células do estroma (veja abaixo). </li><li> Centrífuga placas a 2500 rpm em temperatura ambiente por 90 minutos. Transferência de placas para incubadora a 37 ° C 5% CO 2. </li><li> 4-6 horas mais tarde, a colheita sobrenadante a partir de chapas e recolher as células potencial remanescente em suspensão através de centrifugação. </li><li> Ressuspender pellet (pode ser pequeno) em 48 mL IMDM 10% + citocinas. Dispense 2 mL / poço de ressuspensão de original de quatro bem-6 placas em que a infecção foi realizada e sobrenadante foi coletado. Nota: Sempre prepare 10% IMDM + citocinas fresco no tempo de uso. </li><li> Incubar as placas a 37 ° C 5% CO 2 por sete dias. Colônias deve ser aparente por dia após a infecção e quatro grandes e bem formado por sete dias. A expansão robusta deve render 40-60 colônias / bem no dia sete. </li><li> No sétimo dia pós-infecção, coletar e piscina todas as células (incluindo OP9 estroma) de todos os poços por tratamento com tripsina. Nota: NÃO descartar sobrenadante ou PBS lava empregados durante tripsina treatment.At neste ponto da cultura, algumas colônias podem ser apenas vagamente aderente e existem muitas células flutuar livrementing em suspension.Collect e piscina todos os lava e sobrenadante para garantir que nenhum células potencialmente valiosos são descartados. </li><li> Ressuspender as células em 8 mL IMDM fresca a 10% + citocinas. Distribuir 2 ml / frasco em quatro frascos T75. Adicionar um adicional de 13 mls citocinas + 10% IMDM em cada balão. Incubar a 37 ° C 5% CO 2 por três dias (um total de dez dias após a infecção). </li></ol> Cultura e chapeamento de OP9 estroma <ol><li> Manter OP9 estroma de acordo com protocolos padrão em 20% a-MEM. OP9 células vão alterar as propriedades quando cultivadas a confluência. Sempre dividido em 80% confluência em não mais de 1:03 dividido. </li><li> 24 horas antes da infecção do dia seis EB células derivadas com MSCV-HoxB4-IRES-GFP, placa OP9 25.000 células / poço de quatro bem-6 placas em 20% ao MEM. </li></ol> Fracionamento de recolha e transplante <ol><li> Coletar células expandidas em OP9 estroma de 10 dias através de tratamento com tripsina. Contagem de células. Nota: NÃO descartar sobrenadante ou PBS lava empregadas durante o tratamento de tripsina. Neste ponto, na cultura, algumas colônias podem ser apenas vagamente aderente e existem muitas células flutuando no suspension.Collect e piscina todos os lava e sobrenadante para garantir que nenhum células potencialmente valiosos são descartados. Nota: Uma boa expansão deve render entre 40-50 x 10 6 células / placa 6-bem original infectado, para um total de 160-200 x 10 6 células. </li><li> Células podem ser fracionados através da selecção do grânulo magnético ou FACS acordo com técnicas padronizadas neste ponto no protocolo. </li><li> Para o transplante, as células entregar via retro-orbital ou injeção veia da cauda para Rag-2/gc destinatários deficiente (pesando entre 15-22 gramas) submetido a uma dose fracionada de 9,25 Gy de radiação 2,5 horas. além. Nota: É importante que o peso dos animais cair entre 15-22 gramas no momento da irradiação. Se eles são maiores do que 22 gramas, 9,25 gy não será uma dose suficiente de radiação para garantir a ablação apropriado e células não podem mediar resgate de irradiação letal e / ou enxertar o compartimento hematopoiético. Se o transplante animais de maior porte, a dose de irradiação adequada deve ser determinada experimentalmente. </li><li> A dose mínima de 2-5 x 10 6 células / animal é necessário para garantir resgate de irradiação letal. Se fracionar as células, injetar 2-5 x 10 6 células equivalentes (por exemplo, se a população de interesse representa 10% do pool de células não fracionada, injetar 2-5 x 10 5 células / animal). Nota: Se injetar&gt; 2 x 10 6 células, SEMPRE injetar via veia da cauda para evitar a formação de teratomas em órbita, o que pode resultar quando os números elevados de células são entregues retro-orbital. </li><li> Manter Rag-2 - / - / gc - / - destinatários deficiente em gaiolas autoclavado. Dependendo da &quot;limpeza&quot; do estabelecimento animal, pós-transplante animais podem exigir a administração de água acidificada ou Trimethiprim-Sulfasoxazole (Septra) para a 5 semanas seguintes de radiação letal. </li><li> Esperar&gt; GFP 90% + ES-derivados de leucócitos no sangue periférico em três semanas pós-transplante. Enxerto deve ser multi-linhagem, embora os linfócitos são conhecidos por silêncio retroviral HoxB4-IRES-GFP. </li></ol>

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<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">	
		
		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>C57Bl/6 Rag-2/gamma-c deficient mice</td>
<td>Animal</td>
<td>Taconic Farm</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Plate shaker</td>
<td>Tool</td>
<td>VWR</td>
<td>33998-360</td>
<td>Orbital Shaker by Ikaworks</td>
</tr>
<tr>
<td>Multi-channel pipettor</td>
<td>Tool</td>
<td>VWR</td>
<td>15000-174</td>
<td>ePet by BioHit</td>
</tr>
<tr>
<td>ES trypsin</td>
<td>Reagent</td>
<td>Invitrogen</td>
<td>15090-046</td>
<td>0.25% Trypsin in PBS</td>
</tr>
<tr>
<td>Standard trypsin</td>
<td>Reagent</td>
<td>Invtrogen</td>
<td>25300-062</td>
<td>0.05% Trypsin-EDTA</td>
</tr>
<tr>
<td>PBS</td>
<td>Buffer</td>
<td>Invitrogen</td>
<td>20012-027</td>
<td>&nbsp;</td>
<tr>
<td>Enzyme-free dissociation buffer</td>
<td>Buffer</td>
<td>Invitrogen</td>
<td>13151-014</td>
<td>&nbsp;</td>
<tr>
<td>Dissociation enzyme mix</td>
<td>Buffer</td>
<td>Invitrogen</td>
<td>17104-019</td>
<td>500 mg Collagenase IV</td>
</tr>
<tr>
<td>Hyaluronidase</td>
<td>Reagent</td>
<td>Sigma</td>
<td>H2126</td>
<td>freeze in 500 uL aliquots and avoid repeated freezing and thawing.</td>
</tr>
<tr>
<td>DNAse</td>
<td>Reagent</td>
<td>Sigma</td>
<td>D4527</td>
<td>&nbsp;</td>
<tr>
<td>DMEM</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>10-017CV</td>
<td>&nbsp;</td>
<tr>
<td>Protamine sulfate</td>
<td>Reagent</td>
<td>Sigma</td>
<td>P3369</td>
<td>8 ug/mL</td>
</tr>
<tr>
<td>EB differentiation media</td>
<td>medium</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>Please view recipe on attached Protocol.doc</td>
</tr>
<tr>
<td>10% IMDM</td>
<td>medium</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>Please view recipe on attached Protocol.doc</td>
</tr>
<tr>
<td>10% IMDM+cytokines</td>
<td>medium</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>Please view recipe on attached Protocol.doc</td>
</tr>
<tr>
<td>20% anti-MEM</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>Please view recipe on attached Protocol.doc</td>
</tr>		</tbody>
		</table>
		</div>

derivation of hematopoietic stem cells from murine embryonic stem cells

Uma célula-tronco é definida como uma célula com capacidade para tanto se auto-renovar e gerar descendência diferenciada múltiplas. Células-tronco embrionárias (ESC) são derivadas do blastocisto do embrião e são pluripotentes na capacidade differentiative. Seu potencial differentiative vasta fez-lhes o foco de muita pesquisa centrada na deduzir como persuadi-los para gerar tipos de células clinicamente útil. A derivação bem-sucedida de células-tronco hematopoiéticas (HSC) de rato ESC foi recentemente realizado e pode ser visualizado neste protocolo de vídeo. HSC, sem dúvida, a população de células clinicamente mais explorados, são usados ​​para tratar uma miríade de malignidades hematopoiéticas e distúrbios. No entanto, muitos pacientes que poderiam se beneficiar da terapia HSC não tem acesso a doadores compatíveis. ESC poderiam fornecer uma fonte alternativa de HSC para estes pacientes. O protocolo a seguir estabelece uma linha de base a partir da qual ESC-HSC podem ser estudados e informar os esforços para isolar HSC da ESC humana. Neste protocolo, ESC são diferenciados como corpos embrióides (EBs) por 6 dias disponíveis comercialmente soro pré-selecionados para a diferenciação ótima hematopoiéticas. EBs são, então, dissociado e infectados com HoxB4 retroviral. Infectados EB células derivadas são semeadas em OP9 estroma, uma linhagem de células de medula óssea estromal derivado da calvária de /-M-CSF - ratos, e co-cultivados na presença de hematopoiese promover citocinas por dez dias. Durante este co-cultura, as células infectadas expandir muito, resultando na geração de uma piscina heterogêneo de 100s de milhões de células. Estas células podem então ser usados ​​para resgatar e reconstituir camundongos letalmente irradiados.

Watch this Scientific Journal Video about Derivation of Hematopoietic Stem Cells from Murine Embryonic Stem Cells at JoVE.com

Derivation of Hematopoietic Stem Cells from Murine Embryonic Stem Cells

Este protocolo detalhes a derivação de células-tronco hematopoéticas para transplante de células-tronco embrionárias de rato (ESC) e sua posterior injeção em camundongos letalmente irradiados destinatário. Brevemente, ESC são diferenciados como corpos embrióides, que depois são infectadas com HoxB4 retroviral e co-cultivados com células do estroma OP9 e citocinas hematopoiéticas.

Derivação de Células-Tronco Hematopoéticas murino de Células-Tronco Embrionárias

A stem cell is defined as a cell with the capacity to both self-renew and generate multiple differentiated progeny.  Embryonic stem cells (ESC) are ...

derivation-hematopoietic-stem-cells-from-murine-embryonic-stem

Research

JoVE Journal

Biology

13.2K visualizações.  Harvard Medical School. Este protocolo detalhes a derivação de células-tronco hematopoéticas para transplante de células-tronco embrionárias de rato (ESC) e sua posterior injeção em camundongos letalmente irradiados destinatário. Brevemente, ESC são diferenciados como corpos embrióides, que depois são infectadas com HoxB4 retroviral e co-cultivados com células do estroma OP9 e citocinas hematopoiéticas.

Vídeo: Derivation of Hematopoietic Stem Cells from Murine Embryonic Stem Cells

Propagation of Human Embryonic Stem (ES) Cells

Propagation of Human Embryonic Stem ES Cells

Propagação de-tronco embrionárias humanas (ES) Células

Biologia

Isolation and Transplantation of Hematopoietic Stem Cells (HSCs)

Isolation and Transplantation of Hematopoietic Stem Cells HSCs

Isolamento e Transplante de Células-Tronco Hematopoéticas (HSCs)

Derivation of Human Embryonic Stem Cells by Immunosurgery

The ability of human embryonic stem cells to self-renew and differentiate into all cell types of 
the body suggests that they hold great promise for both medical applications and as a research 
tool for addressing fundamental questions in development and disease. Here, we provide a 
concise, step-by-step protocol for the derivation of human embryonic stem cells from embryos 
by immunosurgical isolation of the inner cell mass. 


The ability of human embryonic stem cells to self-renew and differentiate into all cell types of 
the body suggests that they hold great promise for both medical applications and as a research 
tool for addressing fundamental questions in development and disease. Here, we provide a 
concise, step-by-step protocol for the derivation of human embryonic stem cells from embryos 
by immunosurgical isolation of the inner cell mass.

Derivação de células estaminais embrionárias humanas por Immunosurgery

The ability of human embryonic stem cells to self-renew and differentiate into all cell types of 
the body suggests that they hold great promise for both ...

Isolation and Analysis of Hematopoietic Stem Cells from the Placenta

Hematopoietic stem cells (HSCs) have the ability to self-renew and generate all cell types of the blood lineages throughout the lifetime of an individual. All HSCs emerge during embryonic development, after which their pool size is maintained by self-renewing cell divisions. Identifying the anatomical origin of HSCs and the critical developmental events regulating the process of HSC development has been complicated as many anatomical sites participate during fetal hematopoiesis. Recently, we identified the placenta as a major hematopoietic organ where HSCs are generated and expanded in unique microenvironmental niches (Gekas, et al 2005, Rhodes, et al 2008). Consequently, the placenta is an important source of HSCs during their emergence and initial expansion.
In this article, we show dissection techniques for the isolation of murine placenta from E10.5 and E12.5 embryos, corresponding to the developmental stages of initiation of HSCs and the peak in the size of the HSC pool in the placenta, respectively. In addition, we present an optimized protocol for enzymatic and mechanical dissociation of placental tissue into single-cell suspension for use in flow cytometry or functional assays. We have found that use of collagenase for single-cell suspension of placenta gives sufficient yields of HSCs. An important factor affecting HSC yield from the placenta is the degree of mechanical dissociation prior to, and duration of, enzymatic treatment.
We also provide a protocol for the preparation of fixed-frozen placental tissue sections for the visualization of developing HSCs by immunohistochemistry in their precise cellular niches. As hematopoietic specific antigens are not preserved during preparation of paraffin embedded sections, we routinely use fixed frozen sections for localizing placental HSCs and progenitors.

We have identified the placenta as a major hematopoietic organ during development. We found that hematopoietic stem cells (HSCs) are both generated and expanded in the placenta in unique microenvironmental niches. Here, we describe experimental techniques required for isolation and visualization of HSCs in the mouse placenta.

Isolamento e Análise de Células-Tronco Hematopoéticas da Placenta

Hematopoietic stem cells (HSCs) have the ability to self-renew and generate all cell types of the blood lineages throughout the lifetime of an individual. ...

Chromatin Immunoprecipitation from Human Embryonic Stem Cells

The functional and structural complexity of the myriad of cells in metazoan organisms arises from a small number of stem cells. Stem cells are characterized by two fundamental properties: self-renewal and multipotency that allows a stem cell to differentiate into virtually any cell type 1. The progression stem cell to differentiated cell is characterized by loss of multipotency, structural and morphological changes and the hierarchic activity of transcription factors and signaling molecules, whose activities establish and maintain cell-type specific gene expression patterns. At the molecular level, cell differentiation involves dynamic changes of the structure and composition of chromatin and the detection of those dynamic changes can provide valuable insights into the functional features of stem cells and the cell differentiation process 2,3. Chromatin is a highly compacted DNA-protein complex that forms when cells package chromosomal DNA with proteins, mainly histones 4. Stemcellness and cell differentiation has been correlated with the presence of specific arrays of regulatory proteins such as epigenetic factors, histone variants, and transcription factors 2,3,5.
 Chromatin immunoprecipitation (ChIP) provides a valuable method to monitor the presence of RNA, proteins, and protein modifications in chromatin 6,7. The comparison of chromatin from different cell types can elucidate dynamic changes in protein-chromatin associations that occur during cell differentiation.
Chromatin immunoprecipitation involves the purification of in vivo cross-linked chromatin. The isolated chromatin is reduced to smaller fragments by enzymatic digestion or mechanical force. Chromatin fragments are precipitated using specific antibodies to target proteins or protein and DNA modifications. The precipitated DNA or RNA is purified and used as a template for PCR or DNA microarray based assays. Prerequisites for a successful ChIP are high quality antibodies to the desired antigen and the availability of chromatin from control cells that do not express the target molecule. ChIP can correlate the presence of proteins, protein and RNA modifications, and RNA with specific target DNA, and depending on the choice of outread tool, detects the association of target molecules at specific target genes or in the context of an entire genome. The comparison of the distribution of proteins in the chromatin of differentiating cells can elucidate the dynamic changes of chromatin composition that coincide with the progression of cells along a cell lineage.

The differentiation of ESC coincides with cell-type specific changes in the structure and composition of chromatin. The detection of those changes provides valuable insights into the mechanisms that define stemcellness and cell differentiation. Chromatin immunoprecipitation (ChIP) represents a valuable method to dissect the molecular mechanisms underlying stem cell differentiation.

Cromatina imunoprecipitação de células estaminais embrionárias humanas

The functional and structural complexity of the myriad of cells in metazoan organisms arises from a small number of stem cells. Stem cells are ...

Isolation of Early Hematopoietic Stem Cells from Murine Yolk Sac and AGM

In the mouse embryo, early hematopoiesis occurs simultaneously in multiple organs, which includes the yolk sac and aorta-gonad-mesonephros region. These regions are crucial in establishing the blood system in the embryos and leads to the eventual movement of stem cells into the fetal liver and then development of adult stem cells in the bonemarrow. Early hematopoietic stem cells can be isolated from these organs through microdissection of the embryo followed by flow cytometric sorting to obtain a more pure population. It remains unclear how these stem cell populations contribute to the fetal and adult stem cell pool.   Also, our lab investigates how early stem cells functionally differ from fetal and adult hematopoietic stem cells. Furthermore, our lab sorts different populations of hematopoietic stem cells and test their functional role in the context of a variety of genetic models. In this video, we demonstrate the micro-dissection procedure we commonly use and also show the results of a typical FACS plotfter isolating these rare populations, it is possible to perform a variety of functional assays including: colony assays and bone marrow transplants. 



This video shows how to micro-dissect the yolk sac and aorta-gonad-mesonephros region from embryos and use flow cytometry to sort hematopoietic stem cells.

Isolamento de Células-Tronco Hematopoéticas início de murino saco vitelino e AGM

In the mouse embryo, early hematopoiesis occurs simultaneously in multiple organs, which includes the yolk sac and aorta-gonad-mesonephros region. These ...

Isolation and Derivation of Mouse Embryonic Germinal Cells

The ability of embryonic germinal cells (EG) to differentiate into primordial germinal cells (PGCs) and later into gametes during early developmental stages is a perfect model to address our hypothesis about cancer and infertility. This protocol shows how to isolate primordial germinal cells from developing gonads in 10.5-11.5 days post coitum (dpc) mouse embryos.  Developing gonadal ridges from mouse embryos (C57BL6J) were dissociated by mechanical disruption with collagenase, then plated in a mouse embryo fibroblast feeder layer (MEF-CF1) that was previously mitotically inactivated with mitomycin C in the presence of knockout media and supplemented with Leukemia Inhibitor Factor (LIF), basic Fibroblast Growth Factor (bFGF), and Stem Cell Factor (SCF).  Using these optimized methods for PCG identification, isolation, and establishment of culture conditions permits long term cultures of EG cells for more than 40 days.  The embryonic germinal cell lines showed embryonic phenotype and expression of common used markers of the pluripotent state.  Isolation and derivation of germinal cells in culture provide a tool to understand their development in vitro and offer the opportunity to monitor cumulative damage at genetic and epigenetic levels after exposure to oxidative stress.

The ability of embryonic germinal cells to differentiate into primordial germinal cells during early development stages is a perfect model to address our hypothesis about cancer and infertility. This protocol shows how to isolate primordial germinal cells from developing gonads in 10.5-11.5 days post coitum mouse embryos.

Isolamento e derivação de células embrionárias de rato Germinal

The ability of embryonic germinal cells (EG) to differentiate into primordial germinal cells (PGCs) and later into gametes during early developmental ...

Derivation of Mouse Trophoblast Stem Cells from Blastocysts

Specification of the trophectoderm is one of the earliest differentiation events of mammalian development. The trophoblast lineage derived from the trophectoderm mediates implantation and generates the fetal part of the placenta. As a result, the development of this lineage is essential for embryo survival. Derivation of trophoblast stem (TS) cells from mouse blastocysts was first described by Tanaka et al. 1998. The ability of TS cells to preserve the trophoblast specific property and their expression of stage- and cell type-specific markers after proper stimulation provides a valuable model system to investigate trophoblast lineage development whereby recapitulating early placentation events. Furthermore, trophoblast cells are one of the few somatic cell types undergoing natural genome amplification. Although the molecular pathways underlying trophoblast polyploidization have begun to unravel, the physiological role and advantage of trophoblast genome amplification remains largely elusive. The development of diploid stem cells into polyploid trophoblast cells in culture makes this ex vivo system an excellent tool for elucidating the regulatory mechanism of genome replication and instability in health and disease. Here we describe a protocol based on previous reports with modification published in Chiu et al. 2008.

In this video, we demonstrate the isolation of mouse blastocysts and the derivation of trophoblast stem cells from blastocysts. We also describe conditions for maintenance of the stem cell property as well as induction of differentiation in culture.

Derivação de células-tronco do rato trofoblasto de blastocistos

Specification of the trophectoderm is one of the earliest differentiation events of mammalian development. The trophoblast lineage derived from the ...

Efficient Derivation of Human Cardiac Precursors and Cardiomyocytes from Pluripotent Human Embryonic Stem Cells with Small Molecule Induction

To date, the lack of a suitable human cardiac cell source has been the major setback in regenerating the human myocardium, either by cell-based transplantation or by cardiac tissue engineering1-3. Cardiomyocytes become terminally-differentiated soon after birth and lose their ability to proliferate. There is no evidence that stem/progenitor cells derived from other sources, such as the bone marrow or the cord blood, are able to give rise to the contractile heart muscle cells following transplantation into the heart1-3. The need to regenerate or repair the damaged heart muscle has not been met by adult stem cell therapy, either endogenous or via cell delivery1-3. The genetically stable human embryonic stem cells (hESCs) have unlimited expansion ability and unrestricted plasticity, proffering a pluripotent reservoir for in vitro derivation of large supplies of human somatic cells that are restricted to the lineage in need of repair and regeneration4,5. Due to the prevalence of cardiovascular disease worldwide and acute shortage of donor organs, there is intense interest in developing hESC-based therapies as an alternative approach. However, how to channel the wide differentiation potential of pluripotent hESCs efficiently and predictably to a desired phenotype has been a major challenge for both developmental study and clinical translation. Conventional approaches rely on multi-lineage inclination of pluripotent cells through spontaneous germ layer differentiation, resulting in inefficient and uncontrollable lineage-commitment that is often followed by phenotypic heterogeneity and instability, hence, a high risk of tumorigenicity6-8 (see a schematic in Fig. 1A). In addition, undefined foreign/animal biological supplements and/or feeders that have typically been used for the isolation, expansion, and differentiation of hESCs may make direct use of such cell-specialized grafts in patients problematic9-11. To overcome these obstacles, we have resolved the elements of a defined culture system necessary and sufficient for sustaining the epiblast pluripotence of hESCs, serving as a platform for de novo derivation of clinically-suitable hESCs and effectively directing such hESCs uniformly towards clinically-relevant lineages by small molecules12 (see a schematic in Fig. 1B). After screening a variety of small molecules and growth factors, we found that such defined conditions rendered nicotinamide (NAM) sufficient to induce the specification of cardiomesoderm direct from pluripotent hESCs that further progressed to cardioblasts that generated human beating cardiomyocytes with high efficiency (Fig. 2). We defined conditions for induction of cardioblasts direct from pluripotent hESCs without an intervening multi-lineage embryoid body stage, enabling well-controlled efficient derivation of a large supply of human cardiac cells across the spectrum of developmental stages for cell-based therapeutics.

We have established a protocol for induction of cardioblasts direct from pluripotent human embryonic stem cells maintained under defined conditions with small molecules, which enables derivation of a large supply of human cardiac progenitors and functional cardiomyocytes for cardiovascular repair.

Derivação eficiente dos recursos humanos Precursores cardíaca e Cardiomyocytes pluripotentes a partir de células estaminais embrionárias humanas com a indução de moléculas pequenas

To date, the lack of a suitable human cardiac cell source has been the major setback in regenerating the human myocardium, either by cell-based ...

Phenotypic Analysis and Isolation of Murine Hematopoietic Stem Cells and Lineage-committed Progenitors

The bone marrow is the principal site where HSCs and more mature blood cells lineage progenitors reside and differentiate in an adult organism. HSCs constitute a minute cell population of pluripotent cells capable of generating all blood cell lineages for a life-time1. The molecular dissection of HSCs homeostasis in the bone marrow has important implications in hematopoiesis, oncology and regenerative medicine. We describe the labeling protocol with fluorescent antibodies and the electronic gating procedure in flow cytometry to score hematopoietic progenitor subsets and HSCs distribution in individual mice (Fig. 1). In addition, we describe a method to extensively enrich hematopoietic progenitors as well as long-term (LT) and short term (ST) reconstituting HSCs from pooled bone marrow cell suspensions by magnetic enrichment of cells expressing c-Kit. The resulting cell preparation can be used to sort selected subsets for in vitro and in vivo functional studies (Fig. 2).
Both trabecular osteoblasts2,3 and sinusoidal endothelium4 constitute functional niches supporting HSCs in the bone marrow. Several mechanisms in the osteoblastic niche, including a subset of N-cadherin+ osteoblasts3 and interaction of the receptor tyrosine kinase Tie2 expressed in HSCs with its ligand angiopoietin-15 concur in determining HSCs quiescence. "Hibernation" in the bone marrow is crucial to protect HSCs from replication and eventual exhaustion upon excessive cycling activity6. Exogenous stimuli acting on cells of the innate immune system such as Toll-like receptor ligands7 and interferon-&alpha;6 can also induce proliferation and differentiation of HSCs into lineage committed progenitors. Recently, a population of dormant mouse HSCs within the lin- c-Kit+ Sca-1+ CD150+ CD48- CD34- population has been described8. Sorting of cells based on CD34 expression from the hematopoietic progenitors-enriched cell suspension as described here allows the isolation of both quiescent self-renewing LT-HSCs and ST-HSCs9. A similar procedure based on depletion of lineage positive cells and sorting of LT-HSC with CD48 and Flk2 antibodies has been previously described10. In the present report we provide a protocol for the phenotypic characterization and ex vivo cell cycle analysis of hematopoietic progenitors, which can be useful for monitoring hematopoiesis in different physiological and pathological conditions. Moreover, we describe a FACS sorting procedure for HSCs, which can be used to define factors and mechanisms regulating their self-renewal, expansion and differentiation in cell biology and signal transduction assays as well as for transplantation.

A method to analyse the distribution of bone marrow hematopoietic progenitors in flow cytometry as well as to efficiently isolate highly purified hematopoietic stem cells (HSCs) is described. The isolation procedure is essentially based on magnetic enrichment of c-Kit+ cells and cell sorting to purify HSCs for cellular and molecular studies.

Análise fenotípica e Isolamento de Células-Tronco Hematopoéticas Murino e Lineage comprometidos Progenitores

The bone marrow is the principal site where HSCs and more mature blood cells lineage progenitors reside and differentiate in an adult organism. HSCs ...