Con el apoyo de: USPHS subvención NS38500, Instituto Nacional de Trastornos Neurológicos y Apoplejía NIH, EE.UU., la Alianza de Tecnología Biomédica del Sureste de Wisconsin, Milwauke, WI, EE.UU.; Bryon Riesch Parálisis Foundation, Milwaukee, WI, EE.UU.; Fraternal Order of Eagles, Midwest capítulo , EE.UU.; Nacional de lesión medular Association, Capítulo de Milwaukee, EE.UU., el noreste de Inglaterra Instituto de Células Madre de la Universidad de Newcastle, Reino Unido.

La disección de las Ardenas de adultos folículos ratón bigote <ol><li> Utilizamos 10 semanas a 6 meses de edad los ratones. Ratones más jóvenes a menudo producen más células. La eutanasia de animales de ratón y sumergir todo en una mezcla 1:1 de betadine (solución de yodo) y peróxido de hidrógeno (disponible en farmacias) durante unos 3 minutos. </li><li> Squirt ratón entero, especialmente en la región facial, con un 75% de etanol, y llevar el ratón para microscopio de disección en la campana de flujo laminar. </li><li> Diseccionar las almohadillas bigotes, evitando cuidadosamente el corte en los bulbos pilosos, y la piscina en HBSS. </li><li> Diseccionar los folículos bigotes y una piscina en HBSS a temperatura ambiente. Para ello, la celebración de la piel junto al folículo del pelo con una pinza, a continuación, cortar alrededor de los folículos con las tijeras rectas. Penetran profundamente para evitar lesiones en los bulbos pilosos. </li><li> Levante folículo bigotes fuera de la almohadilla de los bigotes y puesto en la nueva placa con HBSS fresco. </li><li> Ras adiposo sueltos y tejido dérmico con chorros de tampón, hasta los folículos bigotes están limpios. Si es necesario, cortar los nervios a los folículos bigotes y eliminar el tejido adherente y los colores mediante el raspado repetido de HBSS. </li><li> Pin follilce pelo limpio en Sylgard de vidrio recubiertos de una placa de Petri con afiladas agujas de tungsteno, utilizando microforceps para la celebración en la parte de piel al lado del folículo. </li><li> Bigote de corte con un folículo longitudically MicroBlade. Evitar cortar demasiado profundamente, ya que esto dañará el bulto. Eliminar la sangre con chorros repetida de HBSS hasta desaparecido. Aparición de sangre es un buen indicio de que el corte fue bastante profundo. Si el corte longitudial no es lo suficientemente largo, que puede alargarse con micro tijeras dobladas. </li><li> Haga un corte transversal por encima del nivel del seno cavernoso y posteriormente un segundo corte transversal en el nivel en el seno del anillo, cerca de la piel. </li><li> Ahora podrá ver el bulto dentro de la cápsula. </li><li> Hazte con un final de la cápsula de colágeno con la pinza y poner en práctica el bulto con una aguja de tungsteno dobladas. Ahora verá la cápsula vacía y el bulto aislado. </li><li> Piscina aislados protuberancias en una placa de cultivo por separado en HBSS a temperatura ambiente. Asegúrese de que ningún otro tejido está contaminando los bultos agrupados. </li></ol> Cultura de explantes bulto <ol><li> Escudo 35 mm y placas de cultivo con el colágeno mediante la colocación de 50 l de colágeno y 10 l estéril 6% NaCl uno junto al otro. Mezclar bien con una pipeta de doble inclinación Pasteyr y empuje hacia el borde de la placa de cultivo. Incubar toda la noche en un desecador limpio, pero no deje que se seque. Antes de su uso, enjuague los platos con solución salina. </li><li> Preincubarlos colágeno recubiertas y se lava las placas de cultivo de aproximadamente 3 horas con medio de cultivo. El medio de cultivo consiste en un 85% de alfa-MEM modificado, el 10% de suero fetal bovino y 5% el día 11 de extracto de embrión de pollo. </li><li> Después de re-incubación, se elimina el medio de cultivo de las placas y añadir varios bultos con un medio tan poco como sea posible. Retire el exceso de medio de cultivo. </li><li> Incubar durante 1 hora, pero ya no, en la celda incubadora en una atmósfera húmeda con 10% de oxígeno y 5% de CO 2. </li><li> Después de 1 hora, añadir con cuidado 1,5 ml de medio de cultivo. Explantes de bombeo debe cumplir con el sustrato de colágeno. Reemplazar el 50% del medio de cultivo todos los días. </li><li> Dentro de 3 a 4 días, las células altamente migratorias emigrar de los explantes bulto. Tenga en cuenta su morfología estrellada, la movilidad, y la ausencia predominante de contactos célula-célula. En los próximos días, más células emigren, y emigró células proliferan rápidamente. </li><li> Quitar bulto 2 a 3 días después del inicio de EPI-NCSC emigración con una aguja de tungsteno afilada. Si los bultos se quedan más tiempo, tienden a aplanarse y hacen que sea imposible obtener puro EPI-NCSC culturas. </li><li> Importante: las células raras con una morfología aplanada, que se convierten a veces aparente durante varios días más tarde de EPI-NCSC, y que son menos móviles son EPI-NO NCSC, pero supuestas células madre epidérmicas / progenitores. Culturas que consta de estas células, o mezcla de culturas que contienen EPI-NCSC y la posible existencia de células madre epidérmicas / progenitores deben ser desechados. </li><li> Sugerencia: No mantener las células durante mucho tiempo en un medio de explante primario, ya que tienden a diferenciar rápidamente a alta densidad celular, supuestamente debido a autocrina / paracrina de señalización del factor de crecimiento. </li></ol>

<ol>
	<li>Sieber-Blum, M., Grim, M., YF, H. u., Szeder, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pluripotent+neural+crest+stem+cells+in+the+adult+hair+follicle.">Pluripotent neural crest stem cells in the adult hair follicle.</a> Dev. Dyn. 231, 258-269 (2004).</li><li>Sieber-Blum, M., Grim, M., Tuan, R., Grim, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+adult+hair+follicle+-+cradle+for+pluripotent+neural+crest+stem+cells.">The adult hair follicle - cradle for pluripotent neural crest stem cells.</a> Birth Defects Research (Part C). 72, 162-172 (2004).</li><li>Sieber-Blum, M., Schnell, L., Grim, M., Schneider, R., Schwab, M. E. <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+epidermal+neural+crest+stem+cell+(EPI-NCSC)+grafts+in+the+lesioned+spinal+cord.">Characterization of epidermal neural crest stem cell (EPI-NCSC) grafts in the lesioned spinal cord.</a> Pub. 32, 67-81 (2006).</li><li>Hu, Y. F., Zhang, Z. -. J., Sieber-Blum, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+epidermal+neural+crest+stem+cell+(EPI-NCSC)+molecular+signature.">An epidermal neural crest stem cell (EPI-NCSC) molecular signature.</a> Stem Cells. 24, 2692-2702 (2006).</li></ol>

En virtud de su capacidad migratoria, EPI-NCSC se puede aislar como una población de alta pureza de las células madre, que pueden ser expandidas in vitro. Como restos de embriones en un lugar para adultos, EPI-NCSC son candidatos potencialmente atractivo para el futuro de las terapias de reemplazo celular, ingeniería biomédica y / o la medicina regenerativa. Hemos probado EPI-NCSC en un modelo murino de lesión de la médula espinal, donde se muestran las características deseables. A través de perfiles de expresión génica por LongSA...

mouse epidermal neural crest stem cell (epi-ncsc) cultures

EPI-NCSC son los restos de la cresta neural embrionaria en un lugar para adultos, el bulto de los folículos pilosos. Son las células madre multipotenciales que tienen la propiedad fisiológica para generar una amplia gama de tipos de células diferenciadas, incluidas las neuronas, las células nerviosas de soporte, las células del músculo liso, el hueso / células del cartílago y los melanocitos. EPI-NCSC son fácilmente accesibles en el cuero cabelludo y puede ser aislada como una población muy pura de células madre. Este video ofrece un protocolo detallado para la preparación de ratón EPI-NCSC culturas de los folículos de los bigotes. La almohadilla de los bigotes de un ratón adulto se retira, y se diseca folículos bigotes. Los folículos son cortados longitudinalmente y transversalmente posteriormente por encima y por debajo de la región bulto. El bulto se retira de la cápsula de colágeno y se colocan en una placa de cultivo. EPI-NCSC comienzan a emigrar de los explantes bulto 3 a 4 días después.

Watch this Scientific Journal Video about Mouse Epidermal Neural Crest Stem Cell EPI-NCSC Cultures at JoVE.com

Mouse Epidermal Neural Crest Stem Cell EPI-NCSC Cultures

Aquí mostramos nuestro método para aislar la epidermis del ratón las células nerviosas troncales de la cresta (EPI-NCSC). Técnica consiste en micro-disección de folículos bigotes, aislar el bulto y placeing que en el cultivo de tejidos. EPI-NCSC comienzan a emigrar a partir de explantes bulto en el sustrato dentro de 3 a 4 días.

Ratón epidérmico de la cresta neural de células madre (EPI-NCSC) Culturas

EPI-NCSC are remnants of the embryonic neural crest in an adult location, the bulge of hair follicles. They are multipotent stem cells that have the ...

mouse-epidermal-neural-crest-stem-cell-epi-ncsc-cultures

Research

JoVE Journal

Biology

Mouse Epidermal Neural Crest Stem Cell (EPI-NCSC) Cultures

11.5K vistas.  Newcastle University. Aquí mostramos nuestro método para aislar la epidermis del ratón las células nerviosas troncales de la cresta (EPI-NCSC). Técnica consiste en micro-disección de folículos bigotes, aislar el bulto y placeing que en el cultivo de tejidos. EPI-NCSC comienzan a emigrar a partir de explantes bulto en el sustrato dentro de 3 a 4 días.

Video: Mouse Epidermal Neural Crest Stem Cell EPI-NCSC Cultures

Culture of Mouse Neural Stem Cell Precursors

Primary neural stem cell cultures are useful for studying the mechanisms underlying central nervous system development. Stem cell research will increase our understanding of the nervous system and may allow us to develop treatments for currently incurable brain diseases and injuries. In addition, stem cells should be used for stem cell research aimed at the detailed study of mechanisms of neural differentiation and transdifferentiation and the genetic and environmental signals that direct the specialization of the cells into particular cell types.  This video demonstrates a technique used to disaggregate cells from the embryonic day 12.5 mouse dorsal forebrain. The dissection procedure includes harvesting E12.5 mouse embryos from the uterus, removing the "skin" with fine dissecting forceps and finally isolating pieces of cerebral cortex. Following the dissection, the tissue is digested and mechanically dissociated. The resuspended dissociated cells are then cultured in "stem cell" media that favors growth of neural stem cells.

This video describes the method used for isolation of neuroprecursors from the developing cortex of embryonic mice. The procedure for removing embryos from the uterus, dissecting the cortical tissue, and digesting the isolated cerebral cortex is shown.

Cultura de ratón con células madre neurales Precursores

Primary neural stem cell cultures are useful for studying the mechanisms underlying central nervous system development. Stem cell research will increase ...

Investigación

Biología

Dissection of 6.5 dpc Mouse Embryos

Analysis of gene expression patterns during early stages of mammalian embryonic development can provide important clues about gene function, cell-cell interaction and signaling mechanisms that guide embryonic patterning. However, dissection of the mouse embryo from the decidua shortly after implantation can be a challenging procedure, and detailed step-by-step documentation of this process is lacking.

Here we demonstrate how post-implantation (6.5 dpc) embryos are isolated by first dissecting the uterus of a pregnant mouse (detection of the vaginal plug was designated day 0.5 poist coitum) and subsequently dissecting the embryo from maternal decidua. The dissection of Reichert's membrane is described as well as the removal of the ectoplacental cone.

Isolation of postimplantation-stage embryos allows one to study gene patterning and analyze cell-lineage decision making processes during embryonic development, but proper dissection of the early embryo can be challenging. This protocol describes a method for isolating early primitive-streak-stage embryos (~6.5 days post coitum [dpc]).

La disección de embriones de ratón 6,5 dpc

Analysis of gene expression patterns during early stages of mammalian embryonic development can provide important clues about gene function, cell-cell ...

Counting Human Neural Stem Cells

Knowledge of the exact number of viable cells in a given volume of a cell suspension is required for many routine tissue culture manipulations, such as plating cells for immunocytochemistry or for cell transfections. This protocol describes a straightforward and fast method for differentiating between live and dead cells and quantifying the cell concentration and total cell number using a hemacytometer. This procedure first requires detaching cells from a growth surface and resuspending them in media. Next, the cells are diluted in a solution of Trypan blue (ideally to a concentration that will give 20-50 cells per quadrant) and placed in the hemacytometer. Finally, averaging the counts of viable cells in several randomly selected quadrants, dividing the average by the volume of one 1 mm2 quadrant (0.1 &mu;l) and multiplying by the dilution factor gives the number of cells per l. Multiplying this cell concentration by the total volume in &mu;l gives the total cell number. This protocol describes counting human neural stem/precursor cells (hNSPCs), but can also be used for many other cell types.

Knowledge of the exact number of viable cells is required for many tissue culture manipulations. This protocol describes how to differentiate between live and dead cells and quantify cells using a hemacytometer. Although it describes counting human neural stem/precursor cells (hNSPCs), it can be used for other cell types.

Conteo de células madre neurales humanas

Knowledge of the exact number of viable cells in a given volume of a cell suspension is required for many routine tissue culture manipulations, such as ...

Immunocytochemistry: Human Neural Stem Cells

Immunocytochemistry is a very powerful and fairly straightforward method for determining the presence, subcellular localization, and relative abundance of an antigen of interest, most commonly a protein, in cultured cells. This protocol presents an easy-to-follow series of steps that will enable researchers to conserve primary and secondary antibodies while getting high quality, reproducible qualitative and quantitative data out of their staining. There are two aspects of this protocol that help to conserve the volume of antibody necessary for staining. For one, the cells are grown on small, circular coverslips that are placed in wells of a tissue culture plate. After fixation, the cells on coverslips can be removed from the wells of the plate. For antibody staining, the coverslip with cells is inverted onto a small drop of antibody solution on parafilm and is covered with a second piece of parafilm to prevent drying. Using this method, only ~25 &mu;l of antibody solution is needed for each coverslip (or sample) to be stained. This protocol describes immunostaining of human neural stem/precursor cells (hNSPCs), but can be used for many other cell types.

Immunocytochemistry is a powerful method to determine the presence, subcellular localization, and relative abundance of an antigen of interest in cultured cells. This protocol presents an easy-to-follow series of steps that will enable one to conserve antibodies and get the most out of one's staining.

Inmunocitoquímica: células madre neurales humanas

Immunocytochemistry is a very powerful and fairly straightforward method for determining the presence, subcellular localization, and relative abundance of ...

Assessing Neural Stem Cell Motility Using an Agarose Gel-based Microfluidic Device

While microfluidic technology is reaching a new level of maturity for macromolecular assays, cell-based assays are still at an infant stage1. This is largely due to the difficulty with which one can create a cell-compatible and steady microenvironment using conventional microfabrication techniques and materials. We address this problem via the introduction of a novel microfabrication material, agarose gel, as the base material for the microfluidic device. Agarose gel is highly malleable, and permeable to gas and nutrients necessary for cell survival, and thus an ideal material for cell-based assays. We have shown previously that agarose gel based devices have been successful in studying bacterial and neutrophil cell migration2. In this report, three parallel microfluidic channels are patterned in an agarose gel membrane of about 1mm thickness. Constant flows with media/buffer are maintained in the two side channels using a peristaltic pump. Cells are maintained in the center channel for observation. Since the nutrients and chemicals in the side channels are constantly diffusing from the side to center channel, the chemical environment of the center channel is easily controlled via the flow along the side channels. Using this device, we demonstrate that the movement of neural stem cells can be monitored optically with ease under various chemical conditions, and the experimental results show that the over expression of epidermal growth factor receptors (EGFR) enhances the motility of neural stem cells. Motility of neural stem cells is an important biomarker for assessing cells aggressiveness, thus tumorigenic factor3. Deciphering the mechanism underlying NSC motility will yield insight into both disorders of neural development and into brain cancer stem cell invasion.

We demonstrate that the over expression of epidermal growth factor receptors (EGFR) enhances the motility of neural stem cells(NSCs) using a novel agarose gel based microfluidic device. This technology can be readily adaptable to other mammalian cell systems where cell sources are scarce, such as human neural stem cells, and the turn around time is critical.

La evaluación de la motilidad de células madre neurales uso de un gel de agarosa al dispositivo basado en microfluídica

While microfluidic technology is reaching a new level of maturity for macromolecular assays, cell-based assays are still at an infant stage1. This is ...

Generation of Single-Cell Suspensions from Mouse Neural Tissue

Within the nervous system, hundreds of neuronal and glial cell types have been described. Each specific cell type in the brain or spinal cord has a repertoire of cell surface molecules, or molecular determinants, through which it can be identified and characterized. Currently, robust cell identification and separation technologies require single-cell preparations to be generated while simultaneously limiting cell death and destruction of characteristic surface protein. The gentleMACS Dissociator, when used in combination with trypsin or papain-based dissociation kits, can effectively and gently dissociate brain tissue while preserving antigen epitopes and limiting cell loss. Standardized preparation of single-cell suspensions is achieved using C Tubes and optimized, preset gentleMACS Programs. Once generated, single-cell suspensions can be treated with monoclonal conjugates like Anti-Prominin-1 MicroBeads, which identify neural progenitors, or purified further using Myelin Removal Beads.

Dissociating cells from specific tissue types requires specific parameters for tissue aggitation to obtain a high volume of viable, culturable cells. The Miltenyi gentleMACS Dissociator optimizes this task with a simple, practical protocol. In this publication the use of this apparatus on nerual tissue is explained.

Generación de un solo suspensiones de células de tejido de ratón Neural

Within the nervous system, hundreds of neuronal and glial cell types have been described. Each specific cell type in the brain or spinal cord has a ...

Preparation of Pooled Human Platelet Lysate (pHPL) as an Efficient Supplement for Animal Serum-Free Human Stem Cell Cultures

Platelet derived growth factors have been shown to stimulate cell proliferation efficiently in vivo1,2 and in vitro. This effect has been reported for mesenchymal stromal cells (MSCs), fibroblasts and endothelial colony-forming cells with platelets activated by thrombin3-5 or lysed by freeze/thaw cycles6-14 before the platelet releasate is added to the cell culture medium. The trophic effect of platelet derived growth factors has already been tested in several trials for tissue engineering and regenerative therapy.1,15-17 Varying efficiency is considered to be at least in part due to individually divergent concentrations of growth factors18,19 and a current lack of standardized protocols for platelet preparation.15,16 This protocol presents a practicable procedure to generate a pool of human platelet lysate (pHPL) derived from routinely produced platelet rich plasma (PRP) of forty to fifty single blood donations. By several freeze/thaw cycles the platelet membranes are damaged and growth factors are efficiently released into the plasma. Finally, the platelet fragments are removed by centrifugation to avoid extensive aggregate formation and deplete potential antigens. The implementation of pHPL into standard culture protocols represents a promising tool for further development of cell therapeutics propagated in an animal protein-free system.

Preparation of Pooled Human Platelet Lysate pHPL as an Efficient Supplement for Animal Serum-Free Human Stem Cell Cultures

Human platelet lysate is a rich source of growth factors and a potent supplement in cell culture. This protocol presents the process of preparing a large pool of human platelet lysate by starting from platelet rich plasma, performing several freeze-thaw cycles and depleting the platelet fragments.

Preparación de combinados lisado plaquetario humano (pHPL) como un suplemento eficaz de los animales libres de suero humano culturas de células madre

Platelet derived growth factors have been shown to stimulate cell proliferation efficiently in vivo1,2 and in vitro. This effect has been reported for ...

Live Imaging of Cell Motility and Actin Cytoskeleton of Individual Neurons and Neural Crest Cells in Zebrafish Embryos

The zebrafish is an ideal model for imaging cell behaviors during development in vivo. Zebrafish embryos are externally fertilized and thus easily accessible at all stages of development. Moreover, their optical clarity allows high resolution imaging of cell and molecular dynamics in the natural environment of the intact embryo. We are using a live imaging approach to analyze cell behaviors during neural crest cell migration and the outgrowth and guidance of neuronal axons.
Live imaging is particularly useful for understanding mechanisms that regulate cell motility processes. To visualize details of cell motility, such as protrusive activity and molecular dynamics, it is advantageous to label individual cells. In zebrafish, plasmid DNA injection yields a transient mosaic expression pattern and offers distinct benefits over other cell labeling methods. For example, transgenic lines often label entire cell populations and thus may obscure visualization of the fine protrusions (or changes in molecular distribution) in a single cell. In addition, injection of DNA at the one-cell stage is less invasive and more precise than dye injections at later stages.
Here we describe a method for labeling individual developing neurons or neural crest cells and imaging their behavior in vivo. We inject plasmid DNA into 1-cell stage embryos, which results in mosaic transgene expression. The vectors contain cell-specific promoters that drive expression of a gene of interest in a subset of sensory neurons or neural crest cells. We provide examples of cells labeled with membrane targeted GFP or with a biosensor probe that allows visualization of F-actin in living cells1.
Erica Andersen, Namrata Asuri, and Matthew Clay contributed equally to this work.

This protocol describes imaging of individual neurons or neural crest cells in living zebrafish embryos. This method is used to examine cellular behaviors and actin localization using fluorescence confocal time-lapse microscopy.

Imágenes en directo de la motilidad celular y citoesqueleto de actina de las neuronas individuales y las células de la cresta neural en embriones de pez cebra

The zebrafish is an ideal model for imaging cell behaviors during development in vivo. Zebrafish embryos are externally fertilized and thus easily ...

Rapid Fibroblast Removal from High Density Human Embryonic Stem Cell Cultures

Mouse embryonic fibroblasts (MEFs) were used to establish human embryonic stem cells (hESCs) cultures after blastocyst isolation1. This feeder system maintains hESCs from undergoing spontaneous differentiation during cell expansion. However, this co-culture method is labor intensive, requires highly trained personnel, and yields low hESC purity4. Many laboratories have attempted to minimize the number of feeder cells in hESC cultures (i.e. incorporating matrix-coated dishes or other feeder cell types5-8). These modified culture systems have shown some promise, but have not supplanted the standard method for culturing hESCs with mitomycin C-treated mouse embyronic fibroblasts in order to retard unwanted spontaneous differentiation of the hESC cultures. Therefore, the feeder cells used in hESC expansion should be removed during differentiation experiments. Although several techniques are available for purifying the hESC colonies (FACS, MACS, or use of drug resistant vectors) from feeders, these techniques are labor intensive, costly and/or destructive to the hESC. The aim of this project was to invent a method of purification that enables the harvesting of a purer population of hESCs. We have observed that in a confluent hESC culture, the MEF population can be removed using a simple and rapid aspiration of the MEF sheet. This removal is dependent on several factors, including lateral cell-to-cell binding of MEFs that have a lower binding affinity to the styrene culture dish, and the ability of the stem cell colonies to push the fibroblasts outward during the generation of their own "niche". The hESC were then examined for SSEA-4, Oct3/4 and Tra 1-81 expression up to 10 days after MEF removal to ensure maintenance of pluripotency. Moreover, hESC colonies were able to continue growing from into larger formations after MEF removal, providing an additional level of hESC expansion.

Despite ongoing efforts to transition cultures to feeder-free conditions, the derivation and culture of human embryonic stem cells (hESC) remain largely dependent on co-cultures with mouse embryonic feeders (MEFs). Here, we show a novel methodology for rapidly removing feeders from hESC cultures prior to experimentation.

La eliminación rápida de fibroblastos de alta densidad Humanos culturas de células madre embrionarias

Mouse embryonic fibroblasts (MEFs) were used to establish human embryonic stem cells (hESCs) cultures after blastocyst isolation1. This feeder system ...

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 ...