PWD es apoyada por los Institutos Canadienses de Investigación en Salud de becas (CIHR) y una subvención CIHR a Gerald M. Kidder en la Universidad de Western. El autor también desea agradecer Julang Li de la Universidad de Guelph en busca de ayuda con el desarrollo del protocolo que aquí se presenta.

1. Medios Preparación <ol><li> Preparar los medios de comunicación 2-3 horas antes de su uso y el lugar con una tapa suelta en el cultivo celular incubadora donde el experimento se llevará a cabo. Los medios utilizados en el presente Protocolo: <ol><li> Preparar detener medio celular que consiste en DMEM/F12 suplementado con 1 x B27, 40 ng / ml de bFGF, y 20 ng / ml de EGF. </li><li> Preparar germen de medio de diferenciación celular que consiste en M199 suplementado con 0,05 UI de FSH, 0,03 UI de LH, 3 mg / ml de BSA, 5 l / ml de STI, 0,23 mM de piruvato sódico, 1 mg / ml de fetuina, y 1 ng / ml de EGF. Un medio de base que consiste de todos los aditivos pero omitiendo la FSH, LH y EGF se puede preparar y se almacenó a 4 ° C durante hasta una semana. </li></ol></li></ol> 2. Stem Cell Culture Preparación <ol><li> Aislar las células madre de crías de ratón recién nacido a lo descrito previamente 12. Utilizar las células madre en el paso 2-4 para la diferenciación in vitro de células germinales. La eficiencia de losFormación OLC está directamente relacionada con la calidad de las células madre de partida. Es mejor para iniciar la diferenciación tan pronto como la población parece limpio y saludable que es generalmente a alrededor de pasaje 2. Además el cultivo de la células madre pasado paso 2 afecta negativamente a la eficiencia de formación de OLC (resultados no publicados). </li><li> 48 horas antes de iniciar la diferenciación de sub-cultivo de las células madre. Retire todos los agregados de células esféricas suspendidas y medios gastados de la placa de cultivo, utilizando una pipeta serológica, y colóquelos en un tubo de 15 ml. Es importante sólo para recoger los agregados esféricos suspendidos de las células y las células no unidas a la parte inferior del plato que se están diferenciando de forma espontánea. </li><li> Sedimentar las células a 500 xg durante 5 min., Descartar el sobrenadante y resuspender en 500 l de medio de células madre recién calentado a 37 ° C. Pipetear suavemente los agregados de disociar en parte las células. No pipetear enérgicamente la células ya que esto reducirá la viabilidad celular. Lavar las células parcialmente disociadas en 9,5 ml de medio de células madre fresca precalentada en un archivo adjunto de 10 cm placa de cultivo celular bajo. </li><li> Volver a las células a un 37 ° C, 5% de CO 2 incubadora de cultivo celular durante 48 horas antes de la iniciación de la diferenciación. </li></ol> 3. Diferenciación OLC <ol><li> Con una pipeta serológica eliminar las células madre de la placa de cultivo y colocar en un tubo de 15 ml, dejar atrás las células unidas. Sedimentar las células a 500 xg y resuspender en 500 l de PBS estéril. Pipeta vigoroso de las células utilizando una amplia llevaban 1.000 l punta en grupos no mayores de 10 a 20 células. Periódicamente extraer una pequeña cantidad de células, durante la disociación, y comprobar bajo un microscopio de luz blanca para confirmar células agregadas son en grupos de 10-20 células individuales. En la disociación se reduce la viabilidad celular. </li><li> Añadir 9,5 ml de PBS a las células disociadas y agregue 15 l de esta suspensión celular a un hemocitómetro para el recuento celular. Sedimentar las células a 500 xg durante 5 min. </li><li> Vuelva a suspender las células a una concentración de 1.32X10 6 células / ml en medio de diferenciación. </li><li> Placa de las células mediante la adición de 500 l por pocillo en un fondo plano de 24 pocillos plato suspensión. </li><li> Coloque el plato bien 24 en una incubadora de cultivo celular a 37 ° C en 5% de CO 2 durante 48 horas. Retire 250 l de medio de cada pocillo y colocar en un tubo de 1,5 ml debidamente etiquetado. Añadir 250 l diferenciación medio fresco a cada pocillo. Centrifugar el medio gastado a 500 xg durante 5 min. y desechar el sobrenadante. Resuspender las células sedimentadas en medio de 50 l diferenciación fresca y volver a la cultura pocillo correspondiente en la placa de diferenciación. </li><li> Cada 48 horas cambia la mitad de la media hasta el día 12 de diferenciación. </li></ol>

<ol>
	<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. H., McLaren, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Primordial+germ+cells+in+the+mouse+embryo+during+gastrulation.">Primordial germ cells in the mouse embryo during gastrulation.</a> Development. 110, 521-528 (1990).</li><li>Hubner, K., Fuhrmann, G., 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=Derivation+of+oocytes+from+mouse+embryonic+stem+cells.">Derivation of oocytes from mouse embryonic stem cells.</a> Science. 300, 1251-1256 (2003).</li><li>Toyooka, Y., Tsunekawa, N., Akasu, R., Noce, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Embryonic+stem+cells+can+form+germ+cells+in+vitro.">Embryonic stem cells can form germ cells in vitro.</a> Proc. Natl. Acad. Sci. 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. W., Liu, 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=In+vitro+and+in+vivo+germ+line+potential+of+stem+cells+derived+from+newborn+mouse+skin.">In vitro and in vivo germ line potential of stem cells derived from newborn mouse skin.</a> PLoS One. 6, e20339 (2011).</li><li>Linher, K., Dyce, P., 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=Primordial+germ+cell-like+cells+differentiated+in+vitro+from+skin-derived+stem+cells.">Primordial germ cell-like cells differentiated in vitro from skin-derived stem cells.</a> PLoS One. 4, e8263 (2009).</li><li>Hayashi, K., Ogushi, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Offspring+from+Oocytes+Derived+from+in+Vitro+Primordial+Germ+Cell-Like+Cells+in+Mice.">Offspring from Oocytes Derived from in Vitro Primordial Germ Cell-Like Cells in Mice.</a> Science. , (2012).</li></ol>

No hay conflictos de interés declarado.

Hasta la fecha OLC funcionales no se han desarrollado completamente utilizando un ensayo in vitro. Recientemente, un estudio realizado por Hayashi et al. Fue capaz de producir descendencia de PGC-como las células formadas in vitro e in vivo transferido para el desarrollo adicional 14. A partir de células madre embrionarias o de células pluripotentes inducidas que fueron capaces de formar PGC como las células que, cuando se recuperaron después de trasplante in vivo<...

Durante la embriogénesis temprana, la gametogénesis se produce a través de una serie de etapas, incluyendo células germinales primordiales (PGC) de formación, la migración, y, finalmente, la colonización de las crestas gonadales. Durante este tiempo las CGP se someten a la proliferación y diferenciación en cada vez más gametos maduros 1. El hecho de que las CGP migran desde la base de la alantoides en el intestino posterior del embrión y, finalmente, a lo largo de la pared dorsal eventualmente colonizar las crestas gonadales los hace extremadamente difícil de estudiar 2. A pesar de los avances en el campo, los estudios que intentan comprender la formación de PGC y la diferenciación han sido impedidos por su limitado número, la ubicación y naturaleza migratoria 3,4. En los últimos años las células madre embrionarias se han demostrado tener el potencial para formar células germinales in vitro 5,6. Del mismo modo, varias células madre somáticas también se han demostrado tener el potencial para formar células germinales Folldebido en cultivo in vitro 7-11. Recientemente las células madre aisladas de la piel de ratones recién nacidos fueron diferenciadas in vitro en células germinales como y ovocitos en fase inicial 12. Durante la diferenciación del subconjunto de las células madre que expresan Oct4 aumentó y se formaron estructuras similares a los complejos cumulus-ovocito. Las células similares a los ovocitos (OLC) se pueden recoger a partir de las culturas y comparación con los ovocitos naturales. El uso de este método de cultivo OLC miden 40-45 micras se obtienen que expresan marcadores similares a los ovocitos como Gdf9b, VASA y DAZL. Hasta la fecha los OLC resultantes siguen siendo incapaces de madurar o ser fecundado 12. Aunque los OLC siguen siendo incapaz de funcionar el protocolo utilizado para formar estos OLC aún puede tener utilidad como un ensayo para estudiar la formación y el desarrollo de las células germinales en estadio anteriores dentro de un cerrado sistema in vitro. La publicación original discutir la formación de la OLC de locélulas madre matic utilizan piel porcina fetal como fuente de células madre 8. Ampliando este estudio las células PGC-como formados temprano durante la diferenciación inducida mostraron ser los precursores de la expresos tales marcadores PGC OLC y como OCT4, VASA, STELLA, C-KIT y DAZL 13. Este dato apoya el potencial de la utilización de este sistema para estudiar la formación de células germinales y diferenciación in vitro. El protocolo utilizado para formar OLC de piel de ratón recién nacido se demuestra en este artículo de vídeo. Este protocolo ofrece un modelo in vitro para estudiar el desarrollo de células germinales que puede proporcionar un medio para elucidar los factores importantes para su proliferación y diferenciación.

<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

El estudio de la formación de células germinales y diferenciación ha sido tradicionalmente muy difícil debido a los números bajos de células y su ubicación en lo profundo de embriones en desarrollo. La disponibilidad de un &quot;cerrado&quot; en el sistema basado en vitro podría resultar muy valiosa para nuestra comprensión de la gametogénesis. La formación de células similares a los ovocitos (OLC) a partir de células madre somáticas, aislados de la piel del ratón recién nacido, se ha demostrado y se puede visualizar en este protocolo video. Los OLC resultantes expresan diversos marcadores consistentes con ovocitos tales como Oct4, Vasa, Bmp15, y SCP3. Sin embargo, siguen siendo no pueden someterse a la maduración o la fertilización debido a un fallo para completar la meiosis. Este protocolo proporcionará un sistema que es útil para el estudio de la formación de fase temprana y la diferenciación de las células germinales en gametos más maduros. Durante la diferenciación temprana el número de células que expresan Oct4 (potenciales células de gérmenes similares) alcanza ~ 5%, sin embargo actualmente la formación de OLC sigue siendo relativamente ineficiente. El protocolo es relativamente sencillo, aunque se debe tener especial cuidado para asegurar la población de células de partida es saludable y en un paso temprano.

Inicialmente, las células se adhieren a la placa de fondo la cultura y se extienden. En 42-72 h en la diferenciación de células positivas Oct4 pequeñas suspendidas forman y proliferan (Figura 1A). Poco después de la visualización de estas células la mayoría desaparecerá y las células unidas se formará agregados de colonias densas en la parte inferior cultura. Después de unos pocos días estos agregados se separe de la superficie de cultivo. En algunos de estos agregados se puede observar una...

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

En los últimos años la formación de las células germinales que utilizan en los métodos de cultivo in vitro se ha demostrado usando varios tipos diferentes de células madre somáticas. En este artículo se presentará visualmente la diferenciación de las células madre derivadas de ratones recién nacidos a principios de células ovocitos similares.

La diferenciación de ratón recién nacido piel derivados de las células madre en células germinales-como<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 vistas.  The University of Western Ontario. En los últimos años la formación de las células germinales que utilizan en los métodos de cultivo in vitro se ha demostrado usando varios tipos diferentes de células madre somáticas. En este artículo se presentará visualmente la diferenciación de las células madre derivadas de ratones recién nacidos a principios de células ovocitos similares.

Video: 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.

En la diferenciación in vitro de la madre embrionarias de ratón (MES), las células con el método de gota

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 ...

Investigación

Biología

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.

La diferenciación de células madre embrionarias en los precursores de oligodendrocitos

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.

La reprogramación de células somáticas humanas en células madre pluripotentes inducidas (iPSCs) utilizando el vector retroviral con las buenas prácticas agrarias

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.

La diferenciación eficiente de las células madre embrionarias de ratón en neuronas motoras

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.

Generación de ratones derivados de células madre pluripotentes inducidas

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.

Inducción y Análisis de epitelial a mesenquimal de transición

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 Microinyección en pez cebra para modelar la lesión 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.

Una interfaz gráfica de usuario para el seguimiento asistido por software de la concentración de proteínas en protones dinámicos celulares

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 celular masiva inyección de células madre embrionarias conduce a mayores tasas 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.

Aislamiento, proliferación y diferenciación de células madre derivadas de tejido adiposo de macaco 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) ...