PWD é apoiado por um Canadian Institutes of Health Research comunhão (CIHR) e uma bolsa CIHR para Gerald M. Kidder na Universidade Ocidental. O autor também gostaria de reconhecer Julang Li, da Universidade de Guelph para obter ajuda com o desenvolvimento do protocolo apresentado aqui.

1. Preparação de Mídia <ol><li> Prepare a mídia de 2-3 horas antes do uso e lugar com uma tampa solta na cultura de células incubadora onde o experimento será ocorrendo. Meios utilizados no presente protocolo: <ol><li> Prepare a haste meio celular que consiste em DMEM/F12 suplementado com 1 x B27, 40 ng / ml de bFGF, e 20 ng / ml de EGF. </li><li> Prepara meio de diferenciação das células germinativas que consiste em M199 suplementado com 0,05 UI de FSH, LH 0,03 UI, 3 mg / ml de BSA, 5 ul / ml ITS, 0,23 mM de piruvato de sódio, 1 mg / ml de fetuina e 1 ng / ml de EGF. Um meio de base consistindo de todos os aditivos, mas omitindo a FSH, LH e EGF podem ser preparadas e armazenadas a 4 ° C durante até uma semana. </li></ol></li></ol> 2. Preparação de células-tronco Cultura <ol><li> Isolar células-tronco de filhotes recém-nascidos de rato, como descrito anteriormente 12. Utilizar células-tronco no trecho 2-4 na diferenciação de células germinativas in vitro. A eficiênciaFormação OLC está directamente relacionada com a qualidade das células estaminais iniciais. É melhor iniciar a diferenciação assim como a população aparece limpo e saudável, que é geralmente de cerca de passagem 2. Além disso a cultura de células-tronco passado passagem 2 afeta negativamente a eficiência de formação OLC (resultados não publicados). </li><li> 48 h antes do início da diferenciação sub-cultura das células estaminais. Remova todos os agregados suspensos esféricas celulares e mídia passou da placa de cultura, com uma pipeta sorológica, e coloque em um tubo de 15 ml. É importante recolher apenas os agregados esféricos em suspensão de células e as células não ligadas à parte inferior da cápsula que são espontaneamente diferenciador. </li><li> Agregar as células a 500 xg durante 5 min., Rejeitar o sobrenadante e ressuspender em 500 ul de meio de células estaminais fresco aquecido a 37 ° C. Pipeta suavemente os agregados para se dissociam parcialmente as células. Não pipetar agressivamente o celulars como isso vai reduzir a viabilidade das células. Lave as células parcialmente dissociadas em 9,5 ml de meio de células-tronco pré-aquecido fresco em um anexo de 10 centímetros prato baixa cultura de células. </li><li> Retorno as células a 37 ° C, 5% de CO 2 incubadora de cultura de células durante 48 horas antes do início da diferenciação. </li></ol> 3. Diferenciação OLC <ol><li> Usando uma pipeta sorológica remover as células-tronco a partir da placa de cultura e colocar em um tubo de 15 ml, deixar para trás as células anexados. Agregar as células a 500 xg e ressuspender em 500 ul de PBS estéril. Pipeta vigorosa as células usando uma ampla suportou 1.000 ponta mL em pedaços não maiores que 10-20 células. Periodicamente, remover uma pequena quantidade de células, durante a dissociação, e vá sob um microscópio de luz branca para confirmar as células estão em agregados aglomerados de 10-20 células individuais. Mais de dissociação irá resultar na redução da viabilidade das células. </li><li> Adicionar 9,5 ml de PBS às células dissociadas e adicionar 15 ul desta suspensão de células com um hemocitómetro para contagem das células. Agregar as células a 500 xg durante 5 min. </li><li> Re-suspender as células a uma concentração de 1.32X10 6 células / ml em meio de diferenciação. </li><li> Placa as células por adição de 500 ul por cavidade em um fundo plano de 24 poços prato suspensão. </li><li> Colocar o bem prato 24 numa incubadora de cultura de células a 37 ° C em 5% de CO 2 durante 48 horas. Remover 250 mL meio de cada poço e colocar em um tubo ml correspondentemente rotulado 1.5. Adicionar 250 ul de meio de diferenciação fresco a cada poço. Centrifuga-se o meio consumido a 500 xg durante 5 min. e descartar o sobrenadante. Ressuspender as células peletizadas em 50 ul de meio de diferenciação fresco e retornar para a cultura correspondente poço na placa de diferenciação. </li><li> Cada 48 horas mudar metade do médio até ao dia 12 de diferenciação. </li></ol>

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	<li>van den Hurk, R., Zhao, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Formation+of+mammalian+oocytes+and+their+growth,+differentiation+and+maturation+within+ovarian+follicles.">Formation of mammalian oocytes and their growth, differentiation and maturation within ovarian follicles.</a> Theriogenology. 63, 1717-1751 (2005).</li><li>Molyneaux, K. A., Stallock, J., Schaible, K., Wylie, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Time-lapse+analysis+of+living+mouse+germ+cell+migration.">Time-lapse analysis of living mouse germ cell migration.</a> Dev. Biol. 240, 488-498 (2001).</li><li>Lawson, K. A., Hage, W. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clonal+analysis+of+the+origin+of+primordial+germ+cells+in+the+mouse.">Clonal analysis of the origin of primordial germ cells in the mouse.</a> Ciba Found Symp. 182, 68-91 (1994).</li><li>Ginsburg, M., Snow, M. 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U.S.A. 100, 11457-11462 (2003).</li><li>Wang, L., Cao, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oocyte-like+Cells+Induced+from+Mouse+Spermatogonial+Stem+Cells.">Oocyte-like Cells Induced from Mouse Spermatogonial Stem Cells.</a> Cell Biosci. 2, 27 (2012).</li><li>Dyce, P. W., Wen, L., Li, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vitro+germline+potential+of+stem+cells+derived+from+fetal+porcine+skin.">In vitro germline potential of stem cells derived from fetal porcine skin.</a> Nat. Cell Biol. 8, 384-390 (2006).</li><li>Danner, S., Kajahn, J., Geismann, C., Klink, E., Kruse, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Derivation+of+oocyte-like+cells+from+a+clonal+pancreatic+stem+cell+line.">Derivation of oocyte-like cells from a clonal pancreatic stem cell line.</a> Mol. Hum. Reprod. 13, 11-20 (2007).</li><li>Cheng, X., Chen, S., Yu, X., Zheng, P., Wang, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=BMP15+gene+is+activated+during+human+amniotic+fluid+stem+cell+differentiation+into+oocyte-like+cells.">BMP15 gene is activated during human amniotic fluid stem cell differentiation into oocyte-like cells.</a> DNA Cell Biol. 31, 1198-1204 (2012).</li><li>Song, S. H., Kumar, B. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+porcine+multipotent+stem/stromal+cells+derived+from+skin,+adipose,+and+ovarian+tissues+and+their+differentiation+in+vitro+into+putative+oocyte-like+cells.">Characterization of porcine multipotent stem/stromal cells derived from skin, adipose, and ovarian tissues and their differentiation in vitro into putative oocyte-like cells.</a> Stem Cells Dev. 20, 1359-1370 (2011).</li><li>Dyce, P. 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Não há conflitos de interesse declarados.

Até à data OLCS funcionais não têm sido completamente desenvolvida usando um ensaio in vitro. Recentemente, um estudo realizado por Hayashi et al. Foi capaz de produzir descendência de PGC-como células formadas in vitro e in vivo, transferido para o desenvolvimento adicional 14. Começando com células-tronco embrionárias ou células pluripotentes induzidas foram capazes de formar PGC como células que, quando recuperado após transplante in vivo foi capaz d...

Durante a embriogénese precoce, gametogénese ocorre através de uma série de fases, incluindo células germinativas primordiais (PGC), a formação, a migração, e, finalmente, a colonização das cristas das gónadas. Durante este tempo, PGCs sofrer proliferação e diferenciação em cada vez mais maduras gametas 1. O facto de PGCs migrar a partir da base do alantóide no intestino posterior do embrião e, finalmente, ao longo da parede dorsal, eventualmente colonizar as cristas das gónadas que os torna extremamente difíceis de estudar 2. Apesar dos avanços na área, estudos que tentam compreender a formação e diferenciação PGC foram impedidos pelo seu número limitado, localização e natureza migratória 3,4. Nos últimos anos, as células estaminais embrionárias demonstraram ter o potencial para formar células germinativas, in vitro 5,6. Da mesma forma, várias células estaminais somáticas também demonstraram ter o potencial para formar células germinativas exerdevido cultivo in vitro 7-11. Recentemente células-tronco isoladas a partir da pele do rato recém-nascido foram diferenciadas in vitro em células de germes como e ovócitos em estágio inicial 12. Durante a diferenciação do subconjunto das células estaminais que expressam Oct4 aumentada e estruturas que se assemelham complexos cumulus-oócitos foram formados. Os ovócitos do tipo células (OLCS) podem ser colhidos a partir das culturas e comparados com oócitos naturais. Usando este método de medição cultura OLCS 40-45 mM são obtidos que os marcadores semelhantes expresso para oócitos como Gdf9b, VASA e DAZL. Até à data, os OLCS resultantes permanecem incapaz de ser fertilizado ou amadurecer 12. Embora os OLCS permanecem incapazes de funcionar o protocolo utilizado para formar estas OLCS ainda pode ter utilidade como um ensaio para o estudo da formação e desenvolvimento de células germinativas fase anterior num sistema in vitro fechado. A publicação original discutir a formação de OLCS de tãoAs células estaminais matic utilizada pele de porco fetal como fonte de células-tronco 8. Expandindo que o estudo das células, como PGC-formados cedo durante a diferenciação induzida mostraram ser os precursores da OLCS e expressar tais marcadores PGC como OCT4, VASA, STELLA, C-KIT, e DAZL 13. Estes dados apoiam a possibilidade de se utilizar este sistema para estudar a formação de células de gérmen e diferenciação in vitro. O protocolo utilizado para formar OLCS pele de rato recém-nascido será demonstrado neste artigo de vídeo. Este protocolo apresenta um modelo in vitro para estudar o desenvolvimento de células germinativas, que podem fornecer um meio para elucidar factores importantes para a sua proliferação e diferenciação.

<table border="1">
		<tbody>
		 <tr>
			<td>Name of Reagent/Material</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		 </tr>
		 <tr>
			<td>DMEM/F12</td>
			<td>Invitrogen</td>
			<td>12500</td>
			<td></td>
		 </tr>
		 <tr>
			<td>B27</td>
			<td>Invitrogen</td>
			<td>17504044</td>
			<td></td>
		 </tr>
		 <tr>
			<td>EGF</td>
			<td>Invitrogen</td>
			<td>PHG0311</td>
			<td></td>
		 </tr>
		 <tr>
			<td>bFGF</td>
			<td>Invitrogen</td>
			<td>PHG0266</td>
			<td></td>
		 </tr>
		 <tr>
			<td>ITS</td>
			<td>Invitrogen</td>
			<td>41400-045</td>
			<td></td>
		 </tr>
		 <tr>
			<td>BSA</td>
			<td>Sigma</td>
			<td>A-6003</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Sodium Pyruvate</td>
			<td>Invitrogen</td>
			<td>11360-070</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Fetuin</td>
			<td>Sigma</td>
			<td>F3385</td>
			<td></td>
		 </tr>
		 <tr>
			<td>FSH</td>
			<td>Sioux Biochemicals</td>
			<td>915</td>
			<td></td>
		 </tr>
		 <tr>
			<td>LH</td>
			<td>Sioux Biochemicals</td>
			<td>925</td>
			<td></td>
		 </tr>
		 <tr>
			<td>M199</td>
			<td>Invitrogen</td>
			<td>31100-035</td>
			<td></td>
		 </tr>
		 <tr>
			<td>24 well plates</td>
			<td>Nunc</td>
			<td>144530</td>
			<td></td>
		 </tr>
		 <tr>
			<td>10 cm dishes</td>
			<td>VWR</td>
			<td>25384-088</td>
			<td></td>
		 </tr>
		 <tr>
			<td>15 ml tubes</td>
			<td>BD</td>
			<td>352095</td>
			<td></td>
		 </tr>
		</tbody>
 </table>

differentiation of newborn mouse skin derived stem cells into germ-like cells in vitro

Estudar a formação de células germinativas e diferenciação tem sido tradicionalmente muito difícil devido ao número de células de baixa e sua localização no fundo de embriões em desenvolvimento. A disponibilidade de uma &quot;fechada&quot; no sistema baseado em vitro pode se mostrar valiosa para a nossa compreensão de gametogênese. A formação de ovócitos-como células (OLCS) a partir de células-tronco somáticas, isoladas a partir da pele do rato recém-nascido, tem sido demonstrada e pode ser visualizado neste protocolo vídeo. Os OLCS resultantes expressam diversos marcadores consistentes com oócitos como Oct4 Vasa, BMP15, e Scp3. No entanto, continuam a ser incapazes de sofrer maturação ou fertilização, devido a uma falha de completar a meiose. Este protocolo irá proporcionar um sistema que seja útil para estudar a formação de fase precoce e de diferenciação das células germinativas em gametas mais maduros. Durante a diferenciação precoce, o número de células que expressam Oct4 (potenciais células germinativas e similares) atinge a 5%, no entanto o momento de formação de OLCS permanece relativamente ineficiente. O protocolo é relativamente simples que devem ser tomados cuidados especiais para assegurar a população de células de partida é saudável e em uma passagem antecipada.

Inicialmente as células anexar à cultura prato fundo e se espalhar. Às 42-72 horas em diferenciação suspensos oct4 células positivas pequenas formam e proliferam (Figura 1A). Pouco depois da visualização destas células a maioria vão desaparecer e as células ligadas irá formar agregados de colónias densas na parte inferior da cultura. Após alguns dias, estes agregados irá separar da superfície da cultura. Em alguns destes agregados de uma grande célula pode ser observado (Figura ...

Watch this Scientific Journal Video about Differentiation of Newborn Mouse Skin Derived Stem Cells into Germ-like Cells In vitro at JoVE.com

Differentiation of Newborn Mouse Skin Derived Stem Cells into Germ-like Cells In vitro

Nos últimos anos, a formação de células germinativas, utilizando métodos de cultura in vitro tem sido demonstrada utilizando vários tipos diferentes de células estaminais somáticas. Este artigo irá apresentar visualmente a diferenciação de células-tronco derivadas de células de rato recém-nascidos oócito-como iniciais.

Diferenciação de camundongos neonatos pele derivadas de células-tronco em células germinativas semelhantes<em&gt; In vitro</em

Studying  germ cell formation and differentiation has traditionally been very difficult  due to low cell numbers and their location deep within developing ...

differentiation-newborn-mouse-skin-derived-stem-cells-into-germ-like

Research

JoVE Journal

Biology

Differentiation of Newborn Mouse Skin Derived Stem Cells into Germ-like Cells In vitro

9.2K visualizações.  The University of Western Ontario. Nos últimos anos, a formação de células germinativas, utilizando métodos de cultura in vitro tem sido demonstrada utilizando vários tipos diferentes de células estaminais somáticas. Este artigo irá apresentar visualmente a diferenciação de células-tronco derivadas de células de rato recém-nascidos oócito-como iniciais.

Vídeo: Differentiation of Newborn Mouse Skin Derived Stem Cells into Germ-like Cells In vitro

In vitro Differentiation of Mouse Embryonic Stem (mES) Cells Using the Hanging Drop Method

Stem cells have the remarkable potential to develop into many different cell types. When a stem cell divides, each new cell has the potential to either remain a stem cell or become another type of cell with a more specialized function, This promising of science is leading scientists to investigate the possibility of cell-based therapies to treat disease.

When culture in suspension without antidifferentiation factors, embryonic stem cells spontaneously differentiate and form three-dimensional multicellular aggregates. These cell aggregates are called embryoid bodies(EB). Hanging drop culture is a widely used EB formation induction method. The rounded bottom of hanging drop allows the aggregation of ES cells which can provide mES cells a good environment for forming EBs. The number of ES cells aggregatied in a hanging drop can be controlled by varying the number of cells in the initial cell suspension to be hung as a drop from the lid of Petri dish. Using this method we can reproducibly form homogeneous EBs from a predetermined number of ES cells. 

In vitro Differentiation of Mouse Embryonic Stem mES Cells Using the Hanging Drop Method

This video demonstrates how to conduct in vitro differentiation of mouse embryonic stem cells to embryoid bodies using the hanging drop method.

Na diferenciação in vitro de rato-tronco embrionárias (MES) células usando o método da gota de suspensão

Stem cells have the remarkable potential to develop into many different cell types. When a stem cell divides, each new cell has the potential to either ...

Biologia

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 ...

Reprogramming Human Somatic Cells into Induced Pluripotent Stem Cells (iPSCs) Using Retroviral Vector with GFP

Human embryonic stem cells (hESCs) are pluripotent and an invaluable cellular sources for in vitro disease modeling and regenerative medicine1. It has been previously shown that human somatic cells can be reprogrammed to pluripotency by ectopic expression of four transcription factors (Oct4, Sox2, Klf4 and Myc) and become induced pluripotent stem cells (iPSCs)2-4 . Like hESCs, human iPSCs are pluripotent and a potential source for autologous cells. Here we describe the protocol to reprogram human fibroblast cells with the four reprogramming factors cloned into GFP-containing retroviral backbone4. Using the following protocol, we generate human iPSCs in 3-4 weeks under human ESC culture condition. Human iPSC colonies closely resemble hESCs in morphology and display the loss of GFP fluorescence as a result of retroviral transgene silencing. iPSC colonies isolated mechanically under a fluorescence microscope behave in a similar fashion as hESCs. In these cells, we detect the expression of multiple pluripotency genes and surface markers.

Reprogramming Human Somatic Cells into Induced Pluripotent Stem Cells iPSCs Using Retroviral Vector with GFP

A method to generate human induced pluripotent stem cells (iPSCs) via retrovirus-mediated ectopic expression of OCT4, SOX2, KLF4 and MYC is described. A practical way to identify human iPSC colonies based on GFP expression is also discussed.

Reprogramação de células somáticas humanas em células tronco pluripotentes induzidas (iPSCs) usando vetor retroviral com GFP

Human embryonic stem cells (hESCs) are pluripotent and an invaluable cellular sources for in vitro disease modeling and regenerative medicine1. It has ...

Efficient Differentiation of Mouse Embryonic Stem Cells into Motor Neurons

Direct differentiation of embryonic stem (ES) cells into functional motor neurons represents a promising resource to study disease mechanisms, to screen new drug compounds, and to develop new therapies for motor neuron diseases such as spinal muscular atrophy (SMA) and amyotrophic lateral sclerosis (ALS). Many current protocols use a combination of retinoic acid (RA) and sonic hedgehog (Shh) to differentiate mouse embryonic stem (mES) cells into motor neurons1-4. However, the differentiation efficiency of mES cells into motor neurons has only met with moderate success. We have developed a two-step differentiation protocol5 that significantly improves the differentiation efficiency compared with currently established protocols. The first step is to enhance the neuralization process by adding Noggin and fibroblast growth factors (FGFs). Noggin is a bone morphogenetic protein (BMP) antagonist and is implicated in neural induction according to the default model of neurogenesis and results in the formation of anterior neural patterning6. FGF signaling acts synergistically with Noggin in inducing neural tissue formation by promoting a posterior neural identity7-9. In this step, mES cells were primed with Noggin, bFGF, and FGF-8 for two days to promote differentiation towards neural lineages. The second step is to induce motor neuron specification. Noggin/FGFs exposed mES cells were incubated with RA and a Shh agonist, Smoothened agonist (SAG), for another 5 days to facilitate motor neuron generation. To monitor the differentiation of mESs into motor neurons, we used an ES cell line derived from a transgenic mouse expressing eGFP under the control of the motor neuron specific promoter Hb91. Using this robust protocol, we achieved 51&plusmn;0.8% of differentiation efficiency (n = 3; p &lt; 0.01, Student's t-test)5. Results from immunofluorescent staining showed that GFP+ cells express the motor neuron specific markers, Islet-1 and choline acetyltransferase (ChAT). Our two-step differentiation protocol provides an efficient way to differentiate mES cells into spinal motor neurons.

We developed a new protocol to improve efficiency of in vitro differentiation of mouse embryonic stem cells into motor neurons. The differentiated ES cells acquired motor neurons features as evidenced by expression of neuronal and motor neuron markers using immunohistochemical techniques.

Diferenciação eficiente de células-tronco embrionárias em neurônios motores

Direct differentiation of embryonic stem (ES) cells into functional  motor neurons represents a promising resource to study disease mechanisms, to  screen ...

Generation of Mice Derived from Induced Pluripotent Stem Cells

The production of induced pluripotent stem cells (iPSCs) from somatic cells provides a means to create valuable tools for basic research and may also produce a source of patient-matched cells for regenerative therapies. iPSCs may be generated using multiple protocols and derived from multiple cell sources. Once generated, iPSCs are tested using a variety of assays including immunostaining for pluripotency markers, generation of three germ layers in embryoid bodies and teratomas, comparisons of gene expression with embryonic stem cells (ESCs) and production of chimeric mice with or without germline contribution2. Importantly, iPSC lines that pass these tests still vary in their capacity to produce different differentiated cell types2. This has made it difficult to establish which iPSC derivation protocols, donor cell sources or selection methods are most useful for different applications.
The most stringent test of whether a stem cell line has sufficient developmental potential to generate all tissues required for survival of an organism (termed full pluripotency) is tetraploid embryo complementation (TEC)3-5. Technically, TEC involves electrofusion of two-cell embryos to generate tetraploid (4n) one-cell embryos that can be cultured in vitro to the blastocyst stage6. Diploid (2n) pluripotent stem cells (e.g. ESCs or iPSCs) are then injected into the blastocoel cavity of the tetraploid blastocyst and transferred to a recipient female for gestation (see Figure 1). The tetraploid component of the complemented embryo contributes almost exclusively to the extraembryonic tissues (placenta, yolk sac), whereas the diploid cells constitute the embryo proper, resulting in a fetus derived entirely from the injected stem cell line.
Recently, we reported the derivation of iPSC lines that reproducibly generate adult mice via TEC1. These iPSC lines give rise to viable pups with efficiencies of 5-13%, which is comparable to ESCs3,4,7 and higher than that reported for most other iPSC lines8-12. These reports show that direct reprogramming can produce fully pluripotent iPSCs that match ESCs in their developmental potential and efficiency of generating pups in TEC tests. At present, it is not clear what distinguishes between fully pluripotent iPSCs and less potent lines13-15. Nor is it clear which reprogramming methods will produce these lines with the highest efficiency. Here we describe one method that produces fully pluripotent iPSCs and "all- iPSC" mice, which may be helpful for investigators wishing to compare the pluripotency of iPSC lines or establish the equivalence of different reprogramming methods.

Generating induced pluripotent stem cell (iPSC) lines produces lines of differing developmental potential even when they pass standard tests for pluripotency. Here we describe a protocol to produce mice derived entirely from iPSCs, which defines the iPSC lines as possessing full pluripotency1.

Geração de camundongos derivadas de células-tronco pluripotentes induzidas

The production of induced pluripotent stem cells (iPSCs) from somatic cells provides a means to create valuable tools for basic research and may also ...

Induction and Analysis of Epithelial to Mesenchymal Transition

Epithelial to mesenchymal transition (EMT) is essential for proper morphogenesis during development. Misregulation of this process has been implicated as a key event in fibrosis and the progression of carcinomas to a metastatic state. Understanding the processes that underlie EMT is imperative for the early diagnosis and clinical control of these disease states. Reliable induction of EMT in vitro is a useful tool for drug discovery as well as to identify common gene expression signatures for diagnostic purposes. Here we demonstrate a straightforward method for the induction of EMT in a variety of cell types. Methods for the analysis of cells pre- and post-EMT induction by immunocytochemistry are also included. Additionally, we demonstrate the effectiveness of this method through antibody-based array analysis and migration/invasion assays.

A straightforward method is described for the induction of epithelial to mesenchymal transition (EMT) in a variety of cell types. Methods for the analysis of cells in EMT states by immunocytochemistry are included.

Indução e Análise de epitelial para mesenquimal Transição

Epithelial  to mesenchymal transition (EMT) is essential for proper morphogenesis during  development. Misregulation of this  process has been implicated ...

Nephrotoxin Microinjection in Zebrafish to Model Acute Kidney Injury

The kidneys are susceptible to harm from exposure to chemicals they filter from the bloodstream. This can lead to organ injury associated with a rapid decline in renal function and development of the clinical syndrome known as acute kidney injury (AKI). Pharmacological agents used to treat medical circumstances ranging from bacterial infection to cancer, when administered individually or in combination with other drugs, can initiate AKI. Zebrafish are a useful animal model to study the chemical effects on renal function in vivo, as they form an embryonic kidney comprised of nephron functional units that are conserved with higher vertebrates, including humans. Further, zebrafish can be utilized to perform genetic and chemical screens, which provide opportunities to elucidate the cellular and molecular facets of AKI and develop therapeutic strategies such as the identification of nephroprotective molecules. Here, we demonstrate how microinjection into the zebrafish embryo can be utilized as a paradigm for nephrotoxin studies.

Renal injuries incurred from nephrotoxins, which include drugs ranging from antibiotics to chemotherapeutics, can result in complex disorders whose pathogenesis remains incompletely understood. This protocol demonstrates how zebrafish can be used for disease modeling of these conditions, which can be applied to the identification of renoprotective measures.

Nefrotoxina microinjeção no peixe-zebra ao modelo de lesão renal aguda

The kidneys are susceptible to harm from exposure to chemicals they filter from the bloodstream. This can lead to organ injury associated with a rapid ...

A Graphical User Interface for Software-assisted Tracking of Protein Concentration in Dynamic Cellular Protrusions

Filopodia are dynamic, finger-like cellular protrusions associated with migration and cell-cell communication. In order to better understand the complex signaling mechanisms underlying filopodial initiation, elongation and subsequent stabilization or retraction, it is crucial to determine the spatio-temporal protein activity in these dynamic structures. To analyze protein function in filopodia, we recently developed a semi-automated tracking algorithm that adapts to filopodial shape-changes, thus allowing parallel analysis of protrusion dynamics and relative protein concentration along the whole filopodial length. Here, we present a detailed step-by-step protocol for optimized cell handling, image acquisition and software analysis. We further provide instructions for the use of optional features during image analysis and data representation, as well as troubleshooting guidelines for all critical steps along the way. Finally, we also include a comparison of the described image analysis software with other programs available for filopodia quantification. Together, the presented protocol provides a framework for accurate analysis of protein dynamics in filopodial protrusions using image analysis software.

We present a software solution for semi-automated tracking of relative protein concentration along the length of dynamic cellular protrusions.

Uma interface de usuário gráfica para rastreamento assistido por software da concentração de proteínas em protrusões celulares dinâmicas

Filopodia are dynamic, finger-like cellular protrusions associated with migration and cell-cell communication. In order to better understand the complex ...

Trans-inner Cell Mass Injection of Embryonic Stem Cells Leads to Higher Chimerism Rates

In an effort to increase efficiency in the creation of genetically modified mice via ES Cell methodologies, we present an adaptation to the current blastocyst injection protocol. Here we report that a simple rotation of the embryo, and injection through Trans-Inner cell mass (TICM) increased the percentage of chimeric mice from 31% to 50%, with no additional equipment or further specialized training. 26 different inbred clones, and 35 total clones were injected over a period of 9 months. There was no significant difference in either pregnancy rate or recovery rate of embryos between traditional injection techniques and TICM. Therefore, without any major alteration in the injection process and a simple positioning of the blastocyst and injecting through the ICM, releasing the ES cells into the blastocoel cavity can potentially improve the quantity of chimeric production and subsequent germline transmission.

Here we present a protocol to increase chimera production without the use of new equipment. A simple orientation change of the embryo for injection can increase the number of embryos produced, and potentially reduce the timeline to germline transmission.

Trans-interno pilha injeção maciça de células-tronco embrionárias leva a taxas mais elevadas de quimerismo

In an effort to increase efficiency in the creation of genetically modified mice via ES Cell methodologies, we present an adaptation to the current ...

Isolation, Proliferation and Differentiation of Rhesus Macaque Adipose-Derived Stem Cells

Adipose tissue provides a rich and accessible source of multipotent stem cells, which are able to self-renew. These adipose-derived stem cells (ADSCs) provide a consistent ex vivo cellular system that are functionally like that of in vivo adipocytes. Use of ADSCs in biomedical research allows for cellular investigation of adipose tissue metabolic regulation and function. ADSC differentiation is necessary for adequate adipocyte expansion, and suboptimal differentiation is a major mechanism of adipose dysfunction. Understanding changes in ADSC differentiation is crucial to understanding the development of metabolic dysfunction and disease. The protocols described in this manuscript, when followed, will yield mature adipocytes that can be used for several in vitro functional tests to assess ADSC metabolic function, including but not limited to assays measuring glucose uptake, lipolysis, lipogenesis, and secretion. Rhesus macaques (Macaca mulatta) are physiologically, anatomically, and evolutionarily similar to humans and as such, their tissues and cells have been used extensively in biomedical research and for development of treatments. Here, we describe ADSC isolation using fresh subcutaneous and omental adipose tissue obtained from 4&#8211;9-year old rhesus macaques. Adipose tissue samples are enzymatically digested in collagenase followed by filtration and centrifugation to isolate ADSCs from the stromal vascular fraction. Isolated ADSCs are proliferated in stromal media followed by approximately 14&#8211;21 days of differentiation using a cocktail of 0.5 &#956;g/mL dexamethasone, 0.5 mM isobutyl methylxanthine, and 50 &#956;M indomethacin in stromal media. Mature adipocytes are observed at approximately 14 days of differentiation. In this manuscript, we describe protocols for ADSC isolation, proliferation, and differentiation in vitro. Although, we have focused on ADSCs from rhesus macaque adipose tissue, these protocols can be utilized for adipose tissue obtained from other animals with minimal adjustments.

In this article, we describe isolation of rhesus macaque derived adipose-derived stem cells (ADSCs) using an enzymatic tissue digestion protocol. Next, we describe ADSC proliferation which includes cell detachment, counting and plating. Lastly, ADSC differentiation is described using specific adipogenic inducing agents. Additionally, we describe staining techniques to confirm differentiation.

Isolamento, Proliferação e Diferenciação de Células-Tronco Derivadas de Adiposos de Macacos Rhesus

Adipose tissue provides a rich and accessible source of multipotent stem cells, which are able to self-renew. These adipose-derived stem cells (ADSCs) ...