Humana estudos de células-tronco embrionárias no laboratório Teitell são atualmente suportadas por um Instituto da Califórnia de Medicina Regenerativa (CIRM), as sementes conceder RS1-00313. Agradecemos ao Dr. Carla Koehler (UCLA) e membros do laboratório Koehler para fornecer conselhos e idéias nessas e em estudos adicionais.

Alta Resolução Eletroforese Gel Limpar Native (hrCNE) para Complex mitocondrial em Gel-ensaios de atividade Células estaminais embrionárias humanas (hESCs) foram mantidos em uma monocamada de ˠ irradiados ou mitomicina C fibroblastos tratados com embrionárias de camundongos (MEFs), depois passou para o crescimento em Matrigel por 5 dias em MEF-condicionado médio utilizando condições padrão. Para remover contaminantes MEFs, hESCs foram re-semeadas em Matrigel e cultivadas em MEF-condicionado meio de um adicional de 3 dias. Microscopia de imunofluorescência para marcadores de pluripotência Oct-4 e SSEA-4 foi usado para confirmar a falta de diferenciação CTEh. <ol><li> Lavar as células com PBS 1x quente, pH 7,4, seguido por tripsinização (1 ml de tripsina 1x por bem em uma placa de 6 poços) por 5 min. </li><li> Adicionar um volume igual de inibidor de tripsina frescos (1mg/ml em 1x PBS, pH 7,4). Células colheita e centrifugar a 200 g, 5 min, temperatura ambiente. </li><li> Descartar o sobrenadante e ressuspender as células em 0,8 peletizada - 1.7ml (baseado no tamanho do pellet celular) de gelo tampão de isolamento a frio mitocôndrias (83mm de sacarose; 6.6mM imidazol / HCl, pH 7,0) preparada na hora com Cocktail Inibidor 1 &#39;Protease. Incubar no gelo por 10 min. </li><li> Dounce células com um homogeneizador (~ 4-50 AVC). Mancha uma alíquota das células dounced com azul de tripano para verificar integridade de homogeneização utilizando um microscópio de luz. </li><li> Centrifugar a 20.000 g por 10 min a 4 ° C para obter um bruto mitocondrial pelota que também contém núcleos e fragmentos de célula maior. Decantar e desprezar o sobrenadante e pesar o precipitado bruto mitocondrial pellet. O pellet podem ser armazenadas a -80 ° C após congelamento em nitrogênio líquido instante se este é um ponto de parada. NOTA: centrifugação diferencial ou outros baseados em gradiente de procedimentos podem ser usados ​​para isolar e coletar uma fração de membrana pura mitocondrial. Ver ref. 4 para mais detalhes. Esta abordagem alternativa trará a atividade mitocondrial complexo por mg de proteína mitocondrial em vez de atividade complexa por mg de peso celular ou número de celular. A concentração de proteínas mitocondriais terá de ser determinada após a purificação para fazer esta comparação. Além disso, um buffer de isolamento diferentes podem ser necessários para esta abordagem. Para solubilização da fração de membrana pura mitocondrial, consulte a seguinte nota a etapa 6 abaixo. </li><li> Solubilizar o crude mitocondrial pellet no gelo por vórtex com gelo tampão de solubilização a frio (50 mM NaCl, 50 mM imidazol / HCl pH 7.0, 1mM EDTA, 2mM 6-aminohexanoic ácido). Ácido 6-aminohexanoic pode ser substituído com o Cocktail 1x Inibidor da Protease. Use 35μl de tampão de solubilização por 20mg de peso pelota. Adicionar 20μl de 10% w / v digitonina por 20mg de pellet de peso e misture sacudindo o tubo. Incubar por 50-10 min no gelo. Dodecil-bD-maltosídeo ou triton X-100 pode ser substituído por digitonina para solubilizar as proteínas. A escolha do detergente e sua quantidade pode afetar a formação de supercomplexes ou formas multimérica dos complexos mitocondriais. Para mais informações, consulte ref.1. NOTA: A quantidade de detergente necessária para solubilizar uma fração de membrana pura mitocondrial corresponde a uma relação peso / detergente de proteínas variando de 2-6g / g. A proporção ideal para solubilizar as membranas mitocondrial é 2,5 g / g de dodecil-bD-maltosídeo, 3g / g de triton X-100, e 6g / g para digitonina. </li><li> Centrifugar o pellet solubilizados a 100.000 g por 15 min a 4 ° C. Recolher o sobrenadante límpido. </li><li> Adicionar tampão de carregamento para um final de 5% de glicerol w / v e 0,01% w / v Ponceau S (use um 50% de glicerol w / v, 0,1% w / v carregamento Ponceau S solução estoque regulador). </li><li> Carga poços de gel com um volume que contém 20-40mg do crude mitocondrial pellet por pista. Use um gel de gradiente de acrilamida (4% -13) com 3,5% de empilhamento gel. NOTA: Gel de preparação e condições de eletroforese: Para a preparação de gel, use um acrilamida / bis-acrilamida (AA / bisAA) 3 mix da seguinte forma: 48g de acrilamida e 1,5 g de bisacrylamide (49,5% T, 3% C. Onde T é a concentração total de AA e bisAA e C é o percentual de reticulador (bisAA) para monômero total). Gel buffer (3 &#39;): 1,5 M de ácido 6-aminohexanoic; imidazol 75mm, pH 7,0 </li></ol><table style="padding-left: 60px;" border="0"><tbody><tr><td> Gel gradiente: </td><td> 4% </td><td> 13% </td><td> Empilhamento gel: </td><td> 3,5% </td></tr><tr><td> AA / bisAA misture 3 </td><td> 2 ml </td><td> 6,5 ml </td><td></td><td> 0,6 ml </td></tr><tr><td> Gel tampão 3 &#39; </td><td> 8,3 ml </td><td> 8,3 ml </td><td></td><td> 2,7 ml </td></tr><tr><td> Glicerina </td><td></td><td> 5 g </td><td></td><td></td></tr><tr><td> H 2 O </td><td> 14,7 ml </td><td> 5 ml </td><td></td><td> 4,7 ml </td></tr><tr><td> Volume total </td><td> 25 ml </td><td> 25 ml </td><td></td><td> 8 ml </td></tr><tr><td> APS 10% </td><td> 139 mL </td><td> 125 mL </td><td></td><td> 67 mL </td></tr><tr><td> Temed </td><td> 14 mL </td><td> 12,5 mL </td><td></td><td> 6,7 mL </td></tr></tbody></table> Buffer de ânodo: 25mM imidazol / HCl, pH 7,0 Tampão cátodo: tricine 50mm, 7.5mm imidazol / HCl, 0,02% w / v dodecil-bD-maltosídeo, 0,05% w / v desoxicolato, pH 7,0 Despeje e executar géis em uma sala fria (4-7 ° C). A tensão inicial usado é 100V. Quando a amostra entrou no gel de empilhamento, a tensão é elevada a 500V com a corrente limitada a 15mA (para 0,15 &#39;14&#39; 14 cm de gel). Eletroforese é interrompido após 3-4 h, quando a linha nítida de corante vermelho Ponceau S a abordagens frente gel. Alternativamente, um gel pode ser executado durante a noite com tensão constante de 70-100V. <ol><li> Em gel de ensaios de atividade. O tempo de incubação para cada ensaio depende da eficiência de solubilização de proteína e da quantidade de material carregado por bem. Complexos I, IV e V costumam gerar sinais mais fortes do que os complexos II e III. </li></ol> Complexo I (CI) Incubar a fatia de gel com CI buffer (5mM Tris-HCl, pH 7,4; 0.1mg/ml NADH; 2.5mg/ml NBT) em temperatura ambiente por várias horas. CI buffer: Adicionar por 100ml de 5mM Tris-HCl, pH 7.4: 0.01g NADH 0.25g NBT Corrigir o gel em metanol 50% e 10% de ácido acético por 15-45 min. O gel é preservada fixo em 10% de ácido acético. Complexo II (CII) Incubar a fatia de gel com CII buffer (20mM de sódio succinato; methasulfate fenazina 0,2 mM; 2.5mg/ml NBT; 5mM Tris-HCl pH 7,4) em temperatura ambiente por várias horas. CII buffer: Adicionar por 100ml de 5mM Tris-HCl, pH 7.4: Succinato de sódio 1M 200μl Pipete 80 methasulfate fenazina (PMS 250mm dissolvido em DMSO) 0.25g NBT Corrigir o gel como descrito para Complexo I Complexo III (CIII) Incubar a fatia de gel com CIII tampão (fosfato de sódio 50mM, pH 7,2; 0,05% 3,3 tetrahidrocloreto &#39;diaminobenzidina (DAB)) em temperatura ambiente por várias horas. CIII buffer: Adicionar por 100 ml de fosfato de sódio pH, 50mM 7.2: 50mg tetrahidrocloreto diaminobenzidina Corrigir o gel como descrito para Complexo I Complexo IV (CIV) Incubar a fatia de gel com CIV tampão (fosfato de sódio 50mM, pH 7,2; 0,05% 3,3 tetrahidrocloreto &#39;diaminobenzidina (DAB), o cavalo de 50 ìm coração citocromo c) em temperatura ambiente por várias horas. CIV buffer: Adicionar por 100 ml de fosfato de sódio pH, 50mM 7.2: 50mg tetrahidrocloreto diaminobenzidina Cavalo 0.1g coração citocromo c Corrigir o gel como descrito para Complexo I Complexo V (CV) Incubar a fatia de gel com CV tampão (Tris-base de 35mm, 270mm glicina, pH 8,3 a 25 ° C, 14mm MgSO 4, 0,2% w / v Pb (NO 3) 2, 8MM ATP) em temperatura ambiente por várias horas. CV buffer: 100 ml de solução por acrescentar: <table border="0"><tbody><tr><td> Tris-base </td><td> 0.424g </td></tr><tr><td> Glicina </td><td> 2.026g </td></tr><tr><td> MgSO 4 </td><td> 0.345g </td></tr><tr><td> Pb (NO 3) 2 </td><td> 0.29g </td></tr></tbody></table> Não há necessidade de ajustar o pH (deve ser 8.3) - não use ácido ou base. Filtro e adicionar <table border="0"><tbody><tr><td> ATP </td><td> 0.441g </td></tr></tbody></table> Corrigir o gel em metanol 50% por 30 min e transferência para a água.

<ol>
	<li>Wittig, I., Braun, H. -. P., Sch&#747;gger, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blue+native+PAGE.">Blue native PAGE.</a> Nature Protocols. 1, 418-428 (2006).</li><li>Wittig, I., Karas, M., Sch&#747;gger, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+Resolution+Clear+Native+Electrophoresis+for+In-gel+Functional+Assays+and+Fluorescence+Studies+of+Membrane+Protein+Complexes.++6.">High Resolution Clear Native Electrophoresis for In-gel Functional Assays and Fluorescence Studies of Membrane Protein Complexes. 6.</a> Molecular &amp; Cellular Proteomics. 6, 1215-1225 (2007).</li><li>Wittig, I., Carrozzo, R., Santorelli, F. M., Sch&#747;gger, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+assays+in+high-resolution+clear+native+gels+to+quantify+mitochondrial+complexes+in+human+biopsies+and+cell+lines.">Functional assays in high-resolution clear native gels to quantify mitochondrial complexes in human biopsies and cell lines.</a> Electrophoresis. 28, 3811-3820 (2007).</li><li>Castle, J. D., Coligan, J. E., Dunn, B. M., Speicher, D. W., Wingfield, P. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Purification+of+Organelles+from+Mammalian+Cells.">Purification of Organelles from Mammalian Cells.</a> Current Protocols in Protein Science. 4.2, 4.2.1-4.2.57 (2007).</li></ol>

Neste vídeo, temos descrito a extração de complexos de proteína mitocondrial de células estaminais embrionárias humanas, a sua separação por eletroforese em gel de alta resolução clara nativa (hrCNE), e posterior análise por gel em ensaios de atividade catalítica. hrCNE resolve complexos de proteína mitocondrial de membrana com uma resolução comparável à de eletroforese em gel azul nativa e é superior para os ensaios em gel atividade. Esta técnica pode ser empregada não apenas para quantificar respiratória mitocondrial ...

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		<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>0.5M EDTA</td>
<td>&nbsp;</td>
<td>Fisher Scientific</td>
<td>BP120-1</td>
<td>adjust pH to 8.0 with NaOH </td>
</tr>
<tr>
<td>1M NaCl</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>S3014-500MG</td>
<td>&nbsp;</td>
<tr>
<td>1M Sodium succinate</td>
<td>&nbsp;</td>
<td>Fisher Scientific </td>
<td>S413-500</td>
<td>&nbsp;</td>
<tr>
<td>0.1M Sodium phosphate buffer pH 7.2</td>
<td>&nbsp;</td>
<td>Fisher Scientific</td>
<td>BP332-1 and BP329-1</td>
<td>Mix 68.4 ml of 1M Na2HPO4 and 31.6 ml of 1M NaH2PO4 to prepare 0.1M sodium phosphate buffer with pH 7.2 at 25 C </td>
</tr>
<tr>
<td>1M Tricine, pH 7.0 (adjusted with NaOH)</td>
<td>&nbsp;</td>
<td>EMD</td>
<td>9010</td>
<td>store at 4 C </td>
</tr>
<tr>
<td>1M imidazole/HCl, pH 7.0</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>I-2399</td>
<td>store at 4 C</td>
</tr>
<tr>
<td>1M Tris-HCl, pH 7.4</td>
<td>&nbsp;</td>
<td>Fisher Scientific </td>
<td>BP153-1</td>
<td>&nbsp;</td>
<tr>
<td>20% (wt/vol) dodecyl-b-D-maltoside (DDM)</td>
<td>&nbsp;</td>
<td>Fluka</td>
<td>44205-500MG</td>
<td>Dissolved in water. Store 1 ml aliquots at &#x2013;20 C.</td>
</tr>
<tr>
<td>10% (wt/vol) digitonin (>50% purity, used without recrystallization)</td>
<td>&nbsp;</td>
<td>Fluka</td>
<td>37008-1G</td>
<td>Dissolved in water. Store 0.1&#x2013;1 ml aliquots at &#x2013;20 C. Should be warmed up to 95 C before use.</td>
</tr>
<tr>
<td>2M 6-aminohexanoic acid</td>
<td>&nbsp;</td>
<td>Fluka</td>
<td>07260-100G</td>
<td>store at 4 C</td>
</tr>
<tr>
<td>10x Ponceau S/glycerol stock solution</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>P-3504 and G6279-1L</td>
<td>0.1% Ponceau S, 50% glycerol, (wt/vol) in water.</td>
</tr>
<tr>
<td>10% w/v sodium deoxycholate</td>
<td>&nbsp;</td>
<td>Fluka </td>
<td>30970-25G</td>
<td>Dissolved in water. Must be protected from light. Adjust pH to 7.0 with HCl, filter and store at room temperature.</td>
</tr>
<tr>
<td>250 mM phenazine methasulfate (PMS)</td>
<td>&nbsp;</td>
<td>TCI America</td>
<td>P0083</td>
<td>Dissolved in DMSO and aliquoted. Store at &#x2013;20 C.</td>
</tr>
<tr>
<td>Nitro-blue tetrazolium (NBT)</td>
<td>&nbsp;</td>
<td>Amresco </td>
<td>0329-1G</td>
<td>&nbsp;</td>
<tr>
<td>3,3&#x2019;-diaminobenzidine tetrahydrochloride (DAB)</td>
<td>&nbsp;</td>
<td>TCI America </td>
<td>D0078</td>
<td>&nbsp;</td>
<tr>
<td>Pb(NO3)2</td>
<td>&nbsp;</td>
<td>Fisher Scientific </td>
<td>L62-100</td>
<td>&nbsp;</td>
<tr>
<td>MgSO4</td>
<td>&nbsp;</td>
<td>Fisher Scientific </td>
<td>BP213-1</td>
<td>&nbsp;</td>
<tr>
<td>Tris base </td>
<td>&nbsp;</td>
<td>Fisher Scientific </td>
<td>BP152-10</td>
<td>&nbsp;</td>
<tr>
<td>Glycine</td>
<td>&nbsp;</td>
<td>Fisher Scientific</td>
<td>G45-212</td>
<td>&nbsp;</td>
<tr>
<td>Adenosine 5&#x2019;-triphosphate disodium salt (ATP)</td>
<td>&nbsp;</td>
<td>Sigma </td>
<td>A2383-5G</td>
<td>Grade I, minimum 99%</td>
</tr>
<tr>
<td>beta-nicotineamide adenine dinucleotide (NADH) reduced form </td>
<td>&nbsp;</td>
<td>Sigma </td>
<td>N-8129</td>
<td>&nbsp;</td>
<tr>
<td>Cytochrome c From horse heart</td>
<td>&nbsp;</td>
<td>Sigma </td>
<td>C2506-250MG</td>
<td>&nbsp;</td>
<tr>
<td>Sucrose </td>
<td>&nbsp;</td>
<td>Fisher Scientific </td>
<td>BP220-212</td>
<td>&nbsp;</td>
<tr>
<td>100x protease inhibitor cocktail</td>
<td>&nbsp;</td>
<td>Sigma </td>
<td>P8340</td>
<td>Store at &#x2013; 20 C.</td>
</tr>
<tr>
<td>Dimethyl sulfoxide (DMSO)</td>
<td>&nbsp;</td>
<td>Fisher Scientific</td>
<td>D128-500</td>
<td>&nbsp;</td>
<tr>
<td>Trypan blue Stain 0.4%</td>
<td>&nbsp;</td>
<td>Gibco </td>
<td>15250-061</td>
<td>&nbsp;</td>
<tr>
<td>10x Trypsin (0.5%)</td>
<td>&nbsp;</td>
<td>Gibco </td>
<td>15400-054</td>
<td>&nbsp;</td>
<tr>
<td>Trypsin Inhibitor </td>
<td>&nbsp;</td>
<td>Gibco </td>
<td>17075-029</td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

probing for mitochondrial complex activity in human embryonic stem cells

As mitocôndrias são organelas citoplasmáticas que têm um papel fundamental no metabolismo celular ea homeostase, a regulação da rede de sinalização celular e morte celular programada. Mitocôndrias produzem ATP, regular o estado redox citoplasmático e Ca2 + equilíbrio, catabolizar ácidos gordos, sintetizar heme, nucleotídeos, hormônios esteróides, aminoácidos, e ajudar a montar ferro-enxofre em proteínas. Mitocôndria também têm um papel essencial na produção de calor. Mutações do genoma mitocondrial causar vários tipos de desordem humana. O acúmulo de mutações do mtDNA correlaciona-se com o envelhecimento e é suspeito de ter um papel importante no desenvolvimento do câncer. Devido ao seu papel de vital importância em todos os tipos de células, a função das mitocôndrias também deve ser crítico para as células-tronco. Avanços importantes foram feitos em nossa compreensão da viabilidade de células-tronco, proliferação e capacidade de diferenciação. Mas a atividade funcional das células-tronco, no estado de energia particular, a sua, não foi ainda estudado em detalhe. Quase nada se sabe sobre as propriedades mitocondrial de células estaminais embrionárias humanas (hESCs) e seus descendentes precursor diferenciadas. Uma maneira de compreender e avaliar o papel da mitocôndria na função CTEh e potencial de desenvolvimento é o de medir diretamente a atividade dos complexos respiratórios mitocondriais. Aqui, descrevemos de alta resolução de eletroforese em gel claro nativa e posterior visualização em gel atividade como um método para analisar os cinco complexos da cadeia respiratória de hESCs.

Watch this Scientific Journal Video about Probing for Mitochondrial Complex Activity in Human Embryonic Stem Cells at JoVE.com

Probing for Mitochondrial Complex Activity in Human Embryonic Stem Cells

Neste vídeo, vamos mostrar-lhe como os complexos da cadeia respiratória mitocondrial de células estaminais embrionárias humanas podem ser analisadas por ensaios de atividade em gel.

Sondagem para a Atividade Complexo mitocondrial em células estaminais embrionárias humanas

Mitochondria are cytoplasmic organelles that have a primary role in cellular metabolism and homeostasis, regulation of the cell signaling network, and ...

probing-for-mitochondrial-complex-activity-human-embryonic-stem

Research

JoVE Journal

Biology

14.2K visualizações.  University of California, Los Angeles. Neste vídeo, vamos mostrar-lhe como os complexos da cadeia respiratória mitocondrial de células estaminais embrionárias humanas podem ser analisadas por ensaios de atividade em gel.

Vídeo: Probing for Mitochondrial Complex Activity in Human 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

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 ...

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 ...

In vitro Labeling of Human Embryonic Stem Cells for Magnetic Resonance Imaging

Human embryonic stem cells (hESC) have demonstrated the ability to restore the injured myocardium. Magnetic resonance imaging (MRI) has emerged as one of the predominant imaging modalities to assess the restoration of the injured myocardium. Furthermore, ex-vivo labeling agents, such as iron-oxide nanoparticles, have been employed to track and localize the transplanted stem cells. However, this method does not monitor a fundamental cellular biology property regarding the viability of transplanted cells. It has been known that manganese chloride (MnCl2) enters the cells via voltage-gated calcium (Ca2+) channels when the cells are biologically active, and accumulates intracellularly to generate T1 shortening effect. Therefore, we suggest that manganese-guided MRI can be useful to monitor cell viability after the transplantation of hESC into the myocardium.
In this video, we will show how to label hESC with MnCl2 and how those cells can be clearly seen by using MRI in vitro. At the same time, biological activity of Ca2+-channels will be modulated utilizing both Ca2+-channel agonist and antagonist to evaluate concomitant signal changes.

In this video, we are showing how to label human embryonic stem cells (hESC) with manganese chloride (MnCl2) which can enter cells via voltage-gated calcium channels when the cells are biologically active. Additionally, we show the use of MnCl2 as cellular MRI contrast agent to determine the in vitro viability of hESC.

Na rotulagem in vitro de células estaminais embrionárias humanas para Ressonância Magnética

Human embryonic stem cells (hESC) have demonstrated the ability to restore the injured myocardium. Magnetic resonance imaging (MRI) has emerged as one of ...

Culture and Maintenance of Human Embryonic Stem Cells  

Human embryonic stem (hES) cells must be monitored and cared for in order to maintain healthy, undifferentiated cultures. At minimum, the cultures must be  fed  every day by performing a complete medium change to replenish lost nutrients and to keep the cultures free of unwanted differentiation factors. Although a small amount of differentiation is normal and expected in stem cell cultures, the culture should be routinely cleaned up by manually removing, or "picking" differentiated areas. Identifying and removing excess differentiation from hES cell cultures are essential techniques in the maintenance of a healthy population of cells.

Culture and Maintenance of Human Embryonic Stem Cells

This protocol demonstrates how to maintain healthy, undifferentiated human embryonic stem (ES) cells.

Cultura e Manutenção de células estaminais embrionárias humanas

Human embryonic stem (hES) cells must be monitored and cared for in order to maintain healthy, undifferentiated cultures. At minimum, the cultures must be ...

Chromosomal Spread Preparation of Human Embryonic Stem Cells for Karyotyping

Although human embryonic stem cells (hESC) have been shown to present a stable diploid karyotype 1, many studies have reported that depending on culture conditions they become prone to acquire chromosomal anomalies such as addition of whole or parts of chromosomes. Indeed, during long-term culture, karyotypic alterations are observed when enzymatic or chemical dissociation are used 2,3,4, while manual dissection of colonies for passaging retains a stable karyotype 5. Besides, changes in the environment such as the removal of feeder cells also seem to compromise the genetic integrity of hESC 3,6. Once chromosomal alterations could affect cellular physiology, the characterization of the genetic integrity of hESC in vitro is crucial considering hESC as an essential tool in embryogenesis studies and drug testing. Furthermore, for future therapeutic purposes chromosomal changes are a real concern as it is frequently associated to carcinogenesis.
Here we show a simple and useful method to obtain high quality chromosome spreads for subsequent analysis of chromosome set by G-banding, FISH, SKY or CGH techniques 7,8. We recommend checking the chromosomal status routinely with intervals of 5 passages in order to monitor the appearance of translocations and aneuploidies
Priscila Britto and Rafaela Sartore contributed equally to the paper.

Karyotyping is a simple and useful technique widely used for detecting genetic alterations. Here we describe a step by step protocol for chromosome spread preparation of human embryonic stem cells for monitoring the chromosomal status of these cells maintained in culture.

Preparação Spread cromossômica de células estaminais embrionárias humanas para Cariotipagem

Although human embryonic stem cells (hESC) have been shown to present a stable diploid karyotype 1, many studies have reported that depending on culture ...

Freezing and Thawing Human Embryonic Stem Cells

Since James Thomson et al developed a technique in 1998 to isolate and grow hES in culture, freezing cells for later use and thawing and expanding cells from a frozen stock have become important procedures performed in routine hES cell culture. Since hES cells are very sensitive to the stresses of freezing and thawing, special care must taken. Here we demonstrate the proper technique for rapidly thawing hES cells from liquid nitrogen stocks, plating them on mouse embryonic feeder cells, and slowly freezing them for long-term storage.

Since James Thomson et al developed a technique in 1998 to isolate and grow hES in culture, freezing cells for later use and thawing and expanding cells from a frozen stock have become important procedures performed in routine hES cell culture. Since hES cells are very sensitive to the stresses of freezing and thawing, special care must taken. Here we demonstrate the proper technique for rapidly thawing hES cells from liquid nitrogen stocks, plating them on mouse embryonic feeder cells, and slowly freezing them for long-term storage.

Congelamento e descongelamento, células estaminais embrionárias humanas

Since James Thomson et al developed a technique in 1998 to isolate and grow hES in culture, freezing cells for later use and thawing and expanding cells ...

Video Bioinformatics Analysis of Human Embryonic Stem Cell Colony Growth

Because video data are complex and are comprised of many images, mining information from video material is difficult to do without the aid of computer software.  Video bioinformatics is a powerful quantitative approach for extracting spatio-temporal data from video images using computer software to perform dating mining and analysis. In this article, we introduce a video bioinformatics method for quantifying the growth of human embryonic stem cells (hESC) by analyzing time-lapse videos collected in a Nikon BioStation CT incubator equipped with a camera for video imaging. In our experiments, hESC colonies that were attached to Matrigel were filmed for 48 hours in the BioStation CT.  To determine the rate of growth of these colonies, recipes were developed using CL-Quant software which enables users to extract various types of data from video images.  To accurately evaluate colony growth, three recipes were created. The first segmented the image into the colony and background, the second enhanced the image to define colonies throughout the video sequence accurately, and the third measured the number of pixels in the colony over time.  The three recipes were run in sequence on video data collected in a BioStation CT to analyze the rate of growth of individual hESC colonies over 48 hours. To verify the truthfulness of the CL-Quant recipes, the same data were analyzed manually using Adobe Photoshop software. When the data obtained using the CL-Quant recipes and Photoshop were compared, results were virtually identical, indicating the CL-Quant recipes were truthful. The method described here could be applied to any video data to measure growth rates of hESC or other cells that grow in colonies. In addition, other video bioinformatics recipes can be developed in the future for other cell processes such as migration, apoptosis, and cell adhesion.  

Video bioinformatics is the automated processing, analysis, understanding, and data mining of biological spatio-temporal data extracted from microscopic videos. The purpose of this article is to demonstrate a method for measuring human embryonic stem cell colony growth using a video bioinformatics method.

Vídeo Bioinformática Análise de Crescimento Humano embrionárias Colony Stem Cell

Because video data are complex and are comprised of many images, mining information from video material is difficult to do without the aid of computer ...

Differentiation of Embryonic Stem Cells into Oligodendrocyte Precursors

Oligodendrocytes are the myelinating cells of the central nervous system. For regenerative cell therapy in demyelinating diseases, there is significant interest in deriving a pure population of lineage-committed oligodendrocyte precursor cells (OPCs) for transplantation. OPCs are characterized by the activity of the transcription factor Olig2 and surface expression of a proteoglycan NG2. Using the GFP-Olig2 (G-Olig2) mouse embryonic stem cell (mESC) reporter line, we optimized conditions for the differentiation of mESCs into GFP+Olig2+NG2+ OPCs. In our protocol, we first describe the generation of embryoid bodies (EBs) from mESCs. Second, we describe treatment of mESC-derived EBs with small molecules: (1) retinoic acid (RA) and (2) a sonic hedgehog (Shh) agonist purmorphamine (Pur) under defined culture conditions to direct EB differentiation into the oligodendroglial lineage. By this approach, OPCs can be obtained with high efficiency (&gt;80%) in a time period of 30 days. Cells derived from mESCs in this protocol are phenotypically similar to OPCs derived from primary tissue culture. The mESC-derived OPCs do not show the spiking property described for a subpopulation of brain OPCs in situ. To study this electrophysiological property, we describe the generation of spiking mESC-derived OPCs by ectopically expressing NaV1.2 subunit. The spiking and nonspiking cells obtained from this protocol will help advance functional studies on the two subpopulations of OPCs.

We describe a small molecule-based protocol for differentiation of mouse embryonic stem cells into oligodendrocyte precursor cells (OPCs). This protocol generates Olig2+NG2+ OPCs with high efficiency by 30 days of differentiation. We also describe a method to generate "spiking" OPCs that can fire action potentials.

Diferenciação de células-tronco embrionárias em precursores oligodendroglial

Oligodendrocytes are the myelinating cells of the central nervous system. For regenerative cell therapy in demyelinating diseases, there is significant ...

Fate Mapping of Human Embryonic Stem Cells by Teratoma Formation

Human embryonic stem cells (hESCs) have an unlimited capacity for self-renewal, and the ability to differentiate into cells derived from all three embryonic germ layers (1). Directed differentiation of hESCs into specific cell types has generated much interest in the field of regenerative medicine (e.g., (2-5)), and methods for determining the in vivo fate of selected or manipulated hESCs are essential to this endeavor. We have adapted a highly efficient teratoma formation assay for this purpose. A small number of specifically selected hESCs is mixed with undifferentiated wild type hESCs and Phaseolus vulgaris lectin to form a cell pellet. This is grafted beneath the kidney capsule in an immunodeficient mouse. As few as 2.5 x 105 hESCs are needed to form a 16 cm3 teratoma within 8-12 weeks. The fate of the originally selected hESCs can then be determined by immunohistochemistry. This method provides a valuable tool for characterizing tissue-specific reagents for cell-based therapy.

Directed differentiation of hESCs into specific cells has generated much interest in regenerative medicine. We provide a concise, step-by-step protocol for determining the in vivo fate of selected hESCs that provides a valuable tool for characterizing tissue-specific reagents for cell-based therapy.