Dr Hay foi apoiado por uma bolsa RCUK, o Dr. West foi apoiado pelo Departamento de Cirurgia, Dr. Medine foi apoiado por uma subvenção do Fundo Núcleo BHF, o Sr. Baltasar Lucendo-Villarin foi apoiado por um PhD MRC Studenship. Dr. Zhou foi apoiado por uma bolsa do governo chinês.

<ol>
	<li>Asgari, S., Pournasr, B., Salekdeh, G. H., Ghodsizadeh, A., Ott, M., Baharvand, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Induced+pluripotent+stem+cells:+a+new+era+for+hepatology.">Induced pluripotent stem cells: a new era for hepatology.</a> J. Hepatol. 53, 738-751 (2010).</li><li>Hay, D. C., Pernagallo, S., Diaz-Mochon, J. J., Medine, C. N., Greenhough, S., Hannoun, Z., Schrader, J., Black, J. R., Fletcher, J., Dalgetty, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Unbiased+Screening+of+Polymer+Libraries+to+Define+Novel+Substrates+for+Functional+Hepatocytes+with+Inducible+Drug+Metabolism.">Unbiased Screening of Polymer Libraries to Define Novel Substrates for Functional Hepatocytes with Inducible Drug Metabolism.</a> Stem Cell Research. 6, 92-101 (2011).</li><li>Payne, C. M., Samuel, K., Pryde, A., King, J., Brownstein, D., Schrader, J., Medine, C. N., Forbes, S. J., Iredale, J. P., Newsome, P. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Persistence+of+Functional+Hepatocyte+Like+Cells+in+Immune+Compromised+Mice.">Persistence of Functional Hepatocyte Like Cells in Immune Compromised Mice.</a> Liver International. 31, 254-262 (2011).</li><li>Greenhough, S., Medine, C., Hay, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pluripotent+Stem+Cell+Derived+Hepatocyte+Like+Cells+and+their+Potential+in+Toxicity+Screening.">Pluripotent Stem Cell Derived Hepatocyte Like Cells and their Potential in Toxicity Screening.</a> Toxicology. 278, 250-255 (2010).</li><li>Medine, C. N., Greenhough, S., Hay, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Role+of+Stem+Cell+Derived+Hepatic+Endoderm+in+Human+Drug+Discovery.">The Role of Stem Cell Derived Hepatic Endoderm in Human Drug Discovery.</a> Biochemical Society Transactions. 38, 1033-1036 (2010).</li><li>Hannoun, Z., Fletcher, J., Greenhough, S., Medine, C. N., Samuel, K., Sharma, R., Pryde, A., Black, J. R., Ross, J. A., Wilmut, I., Iredale, J. P., Hay, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Comparison+between+Conditioned+Media+and+Serum+Free+Media+in+Human+Embryonic+Stem+Cell+Culture+and+Differentiation.">The Comparison between Conditioned Media and Serum Free Media in Human Embryonic Stem Cell Culture and Differentiation.</a> Cellular Reprogramming. 12, 133-140 (2010).</li><li>Dalgetty, D. M., Medine, C., Iredale, J. P., Hay, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Progress+and+Future+Challenges+in+Stem+Cell-Derived+Liver+Technologies.">Progress and Future Challenges in Stem Cell-Derived Liver Technologies.</a> American Journal of Physiology - Gastrointestinal and Liver Physiology. 297, 241-248 (2009).</li><li>Hay, D. C., Fletcher, J., Payne, C., Terrace, J. D., Gallagher, R. C. J., Snoeys, J., Black, J., Wojtacha, D., Samuel, K., Hannoun, Z., Pryde, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Highly+Efficient+Differentiation+of+hESCs+to+Functional+Hepatic+Endoderm+Requires+ActivinA+and+Wnt3a+Signalling.">Highly Efficient Differentiation of hESCs to Functional Hepatic Endoderm Requires ActivinA and Wnt3a Signalling.</a> Proceedings of the National Academy of Sciences. 105, 12301-12306 (2008).</li><li>Fletcher, J., Cui, W., Samuels, K., Black, J. R., Currie, I. S., Terrace, J. D., Payne, C., Filippi, C., Newsome, P., Forbes, S. J., Ross, J. A., Iredale, J. P., Hay, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Inhibitory+Role+of+Stromal+Cell+Mesenchyme+on+Human+Embryonic+Stem+Cell+Hepatocyte+Differentiation+is+Overcome+by+Wnt3a+Treatment.">The Inhibitory Role of Stromal Cell Mesenchyme on Human Embryonic Stem Cell Hepatocyte Differentiation is Overcome by Wnt3a Treatment.</a> Cloning and Stem Cells. 10, 331-340 (2008).</li></ol>

Não há conflitos de interesse declarados.

Nós desenvolvemos um modelo simples, homogêneo e altamente reprodutível in vitro para gerar níveis escalável de HLCS humana. Nosso modelo foi validado por uma série de laboratórios colaboradores externos. Rotineiramente caracterizar HLCS com células-tronco derivadas usando a nossa caixa de ferramentas na casa de marcadores específicos de desenvolvimento e testes funcionais do fígado (a maioria dos quais estão disponíveis comercialmente). As fases críticas em nosso processo são: a manutenção da p...

Placas de revestimento Matrigel e frascos <ol><li> Matrigel (10 mL, BD Biosciences, UK); armazenar a -20 ° C. </li><li> KO-DMEM (500 mL, Gibco, Invitrogen, UK); armazenar a 4 ° C. </li><li> Placas de cultura de tecido (6 assim, 12 bem, Corning, UK) </li><li> Frasco de cultura de tecidos (25 cm2 ventiladas, Corning, UK) </li></ol> Manutenção CTEh <ol><li> Rato médio de fibroblastos embrionários condicionado (MEF-CM) (100 mL, R &amp; D Systems, EUA); armazenar a -20 ° C. </li><li> BSA solução (50 mL, Sigma Aldrich, UK); armazenar a 4 ° C. </li><li> Fator de crescimento básico de fibroblastos humanos (100 mg, Peprotech, EUA); armazenar a -20 ° C. </li></ol> HESCs Passaging com colagenase <ol><li> Bem confluentes ou frasco de hESCs. </li><li> Matrigel poços revestidos ou frascos conforme o caso. </li><li> Fosfato salina tamponada (-MgCl 2, CaCl-2) (500 mL, Gibco, Invitrogen, UK); armazenar à temperatura ambiente. </li><li> Colagenase IV (1 g, Gibco, InvitrOgen, UK); armazenar a 4 ° C. </li><li> Rato médio de fibroblastos embrionários condicionado (MEF-CM) (100 mL, R &amp; D Systems, EUA). </li><li> Fator de crescimento básico de fibroblastos humanos (100 mg, Peprotech, EUA). </li></ol> Diferenciação de hESCs a endoderme hepática <ol><li> RPMI 1640 (500 mL, Gibco, Invitrogen, UK); armazenar a 4 ° C. </li><li> Suplemento B27 (10 mL, Gibco, Invitrogen, UK); armazenar a -20 ° C. </li><li> Ativina A (2 mg, Peprotech, EUA); armazenar a -20 ° C. </li><li> Recombinante Wnt3a mouse (2 mg, R &amp; D Systems, EUA); armazenar a -20 ° C. </li><li> KO-DMEM (500 mL, Gibco, Invitrogen, UK); armazenar a 4 ° C. </li><li> KO-SR (500 mL, Gibco, Invitrogen, UK); armazenar a -20 ° C. </li><li> Não-aminoácidos essenciais (100 mL, Gibco, Invitrogen, UK); armazenar a 4 ° C. </li><li> β-mercaptoetanol (10 mL, Gibco, Invitrogen, UK); armazenar a 4 ° C. </li><li> DMSO (Sigma Aldrich, UK); armazenar à temperatura ambiente </li><li> Leibovitz L-15 meio de cultura (500 mL, Sigmuma Aldrich, UK); armazenar a 4 ° C. </li><li> Triptose fosfato de caldo de carne (100 mL, Sigma Aldrich, UK); armazenar a 4 ° C. </li><li> Fetal de soro bovino, inactivado pelo calor (500 mL, Gibco, Invitrogen, UK); armazenar a -20 ° C. </li><li> Armazenar a -20 ° C.; hidrocortisona 21 hemissuccinato (100 mg, Sigma Aldrich, UK) </li><li> Insulina (pâncreas bovino) (100 mg, Sigma Aldrich, UK); armazenar a -20 ° C. </li><li> L-Glutamina (100 mL, Gibco, Invitrogen, UK); armazenar a -20 ° C. </li><li> O ácido ascórbico (25 g, Sigma Aldrich, UK); armazenar a -20 ° C. </li><li> Humana HGF (10 mg, Peprotech, EUA); armazenar a -20 ° C. </li><li> Recombinante humana Oncostatina M (OSM) (50 mg, R &amp; D Systems, EUA); armazenar a -20 ° C. </li><li> Seringa de unidade orientado filtro de 0,22 mM (Millipore, UK) </li></ol> Caracterização da CTEh endoderma hepática derivada Imunocoloração <ol><li> Tampão fosfato salino (-MgCl 2, CaCl-2) (500 mL, Gibco, Invitrogen, UK); store à temperatura ambiente. </li><li> PBST, PBS feita com 0,1% de Tween 20 (Sigma-Aldrich, UK). </li><li> Paraformaldeído (PFA) (Sigma-Aldrich, UK) é composto, em PBS, armazenar -20 ° C. </li><li> Glicerol (Sigma-Aldrich, UK), armazenar em temperatura ambiente. </li><li> Tris Base (Sigma-Aldrich, UK), armazenar em temperatura ambiente. </li><li> Etanol </li><li> Soro (ABD Serotech, UK), armazenar a -20 ° C. </li><li> Anticorpo secundário, fluoróforos Alexa (Molecular Probes, Invitrogen, UK). </li><li> MOWIOL 4-88 (Polysciences Inc, EUA) é composta de Tris HCL e glicerol como por instruções dos fabricantes. DAPI (Pierce, Thermo Fisher Scientific, UK) é adicionado à solução MOWIOL na diluição de 1:1000. </li></ol><table border="1"><tbody><tr><td colspan="2"> Anticorpos primários </td><td></td><td></td></tr><tr><td> * Antígeno </td><td> Tipo </td><td> Fornecedor </td><td> Diluição </td></tr><tr><td> ALB </td><td> Monoclonal de camundongo </td><td> Sigma Aldrich </td><td> 05/0100 </td></tr><tr><td> E-caderina </td><td> Monoclonal de camundongo </td><td> Millipore </td><td> 1 / 100 </td></tr><tr><td> α-fetoproteína </td><td> Monoclonal de camundongo </td><td> Sigma </td><td> 1 / 500 </td></tr><tr><td> SSEA-4 FITC </td><td> Monoclonal de camundongo </td><td> Biolegend </td><td> 1 / 100 </td></tr><tr><td> IgG </td><td> Monoclonal de camundongo </td><td> DAKO </td><td> 1 / 500 </td></tr><tr><td colspan="2"> Anticorpos secundários </td><td></td><td></td></tr><tr><td> Anti-camundongo conjugado FITC </td><td> Cabra Monoclonal </td><td> Invitrogen </td><td> 1 / 400 </td></tr></tbody></table> Tabela 2. Os anticorpos utilizados para CTEh imunocoloração derivados hepática endoderme, as concentrações utilizadas, a espécie desenvolveu e as empresas que são comprados a partir de. Análise funcional do endoderma hepática e normalização (por mg de proteína) <ol><li> p4-GLO CYP3A4, CYP1A2, Kits e luminômetro (Promega, EUA). </li><li value="1"> Branco flat bottom 96 placa de ensaio bem (BD Biosciences, UK). </li><li> BCA Assay Kit (Pierce, Thermo Fisher Scientific, UK). </li><li> 96 placa transparente de ensaio bem (IWAKI, UK) </li></ol>

robust generation of hepatocyte-like cells from human embryonic stem cell populations

Apesar dos progressos na modelagem de toxicidade dos medicamentos humanos, muitos compostos falhar durante os ensaios clínicos devido a efeitos colaterais imprevisíveis. O custo de estudos clínicos são substanciais, por isso, é essencial que mais telas de toxicologia preditiva são desenvolvidos e implantados no início do desenvolvimento de drogas (Greenhough et al 2010). Hepatócitos humanos representam o modelo atual do ouro padrão para avaliar a toxicidade dos medicamentos, mas são um recurso limitado que exibem função variável. Portanto, o uso de linhagens de células imortalizadas e modelos de tecido animal são rotineiramente empregados devido à sua abundância. Enquanto ambas as fontes são informativos, eles são limitados pela função pobres, a variabilidade das espécies e / ou instabilidade na cultura (Dalgetty et al 2009). Células-tronco pluripotentes (PSC) são uma importante fonte alternativa de hepatócitos humanos como células (HLCS) (Medine et al 2010). PSCs são capazes de auto-renovação e diferenciação de todos os tipos de células somáticas encontrada no adulto e, portanto, representamuma fonte potencialmente inesgotável de células diferenciadas. Temos desenvolvido um procedimento que é simples, altamente eficiente, passível de automação e rendimento funcional HLCS humano (Hay et al 2008; Fletcher et al 2008; Hannoun et al 2010; Payne et al 2011 e Hay et al 2011). Acreditamos que nossa tecnologia irá levar à produção escalonável de HLCS para descoberta de drogas, modelagem de doença, a construção de extra-corpórea dispositivos e, possivelmente, terapias celulares transplante base.

Watch this Scientific Journal Video about Robust Generation of Hepatocyte-like Cells from Human Embryonic Stem Cell Populations at JoVE.com

Robust Generation of Hepatocyte-like Cells from Human Embryonic Stem Cell Populations

Este artigo incidirá sobre a geração de endoderme hepática humana de populações humanas de células-tronco embrionárias.

Geração robusto de Hepatócito-like Células de populações humanas células-tronco embrionárias

Despite progress in modelling human drug toxicity, many compounds fail during clinical trials due to unpredicted side effects. The cost of clinical ...

robust-generation-hepatocyte-like-cells-from-human-embryonic-stem

Research

JoVE Journal

Biology

47.7K visualizações.  University of Edinburgh. Este artigo incidirá sobre a geração de endoderme hepática humana de populações humanas de células-tronco embrionárias.

Vídeo: Robust Generation of Hepatocyte-like Cells from Human Embryonic Stem Cell Populations

Propagation of Human Embryonic Stem (ES) Cells

Propagation of Human Embryonic Stem ES Cells

Propagação de-tronco embrionárias humanas (ES) Células

Biologia

Derivation of Hematopoietic Stem Cells from Murine Embryonic Stem Cells

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 derived from the blastocyst of the early embryo and are pluripotent in differentiative ability.  Their vast differentiative potential has made them the focus of much research centered on deducing how to coax them to generate clinically useful cell types.  The successful derivation of hematopoietic stem cells (HSC) from mouse ESC has recently been accomplished and can be visualized in this video protocol.  HSC, arguably the most clinically exploited cell population, are used to treat a myriad of hematopoietic malignancies and disorders.  However, many patients that might benefit from HSC therapy lack access to suitable donors.  ESC could provide an alternative source of HSC for these patients.  The following protocol establishes a baseline from which ESC-HSC can be studied and inform efforts to isolate HSC from human ESC.  In this protocol, ESC are differentiated as embryoid bodies (EBs) for 6 days in commercially available serum pre-screened for optimal hematopoietic differentiation.  EBs are then dissociated and infected with retroviral HoxB4.  Infected EB-derived cells are plated on OP9 stroma, a bone marrow stromal cell line derived from the calvaria of  M-CSF-/- mice, and co-cultured in the presence of hematopoiesis promoting cytokines for ten days.  During this co-culture, the infected cells expand greatly, resulting in the generation a heterogeneous pool of 100s of millions of cells.  These cells can then be used to rescue and reconstitute lethally irradiated mice.

This protocol details the derivation of transplantable hematopoietic stem cells from mouse embryonic stem cells (ESC) and their subsequent injection into lethally irradiated recipient mice. Briefly, ESC are differentiated as embryoid bodies, which are then infected with retroviral HoxB4 and co-cultured with OP9 stromal cells and hematopoietic cytokines.

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 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 ...

Generation of Human CD40-activated B cells

CD40-activated B cells (CD40-B cells) have been identified as an alternative source of immuno-stimulatory antigen-presenting cells (APC) for cancer immunotherapy 1-3. Compared to Dendritic cells (DCs), the best characterized APC, CD40-B cells have several distinct biological and technical properties. Similar to DCs, B cells show an increased expression of MHC and co-stimulatory molecules (Fig.1b), exhibit a strong migratory capacity and present antigen presentation efficiently to T cells, after stimulation with interleukin-4 and CD40 ligand (CD40L). However, in contrast to immature or mature DCs, CD40-B cells express the full lymph node homing triad consisting of CD62L, CCR7/CXCR4, and leukocyte function antigen-1 (LFA1, CD11a/CD18), necessary for homing to secondary lymphoid organs (Fig.1a) 3. CD40-B cells can be generated without difficulties from very small amounts of peripheral blood which can be further expanded in vitro to very large amounts of highly-pure CD40-B cells (&gt;109 cells per patient) from healthy donors as well as cancer patients (Fig.1c,d) 1,4. 
In this protocol we demonstrate how to obtain fully activated CD40-B cells from human PBMC. Key molecules for the cell culture are CD40 ligand, interleukin-4 (IL-4) and cyclosporin A (CsA), which are replenished in a 3-4 day culture cycle. For laboratory purposes CD40-stimulation is provided by NIH/3T3 cells expressing recombinant human CD40 ligand (tCD40L NIH/3T3) 5. To avoid contamination with non-transfected cells, expression of the human CD40 ligand on the transfectants has to be checked regularly (Fig.2). 
After 14 days CD40-B cell cultures consist of more than 95% pure B cells and an expansion of CD40-B cells over 65 days is frequently possible without any loss of function 1, 4. CD40-B cells efficiently take up, process and present antigens to T cells 6. They do not only prime na&#970;ve, but also expand memory T cells 7,8. CD40-activated B cells can be used to study B-cell activation, differentiation and function. Moreover, they represent a promising tool for therapeutic or preventive vaccination against tumors 9.

In this video we present the ex vivo generation and expansion of human CD40-activated B cells (CD40-B) from peripheral blood mononuclear cells (PBMC) by stimulation with CD40 ligand and interleukin-4.

Geração de humanos CD40-activated células B

CD40-activated B cells (CD40-B cells) have been identified as an alternative source of immuno-stimulatory antigen-presenting cells (APC) for cancer ...

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.

Mapeamento de destino de células estaminais embrionárias humanas por formação de teratomas

Human embryonic stem cells (hESCs) have an unlimited capacity for self-renewal, and the ability to differentiate into cells derived from all three ...

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