Los autores agradecen a Andrea Axtell, Satoshi Itoh, MD, Velotta Jeff, MD, Hoyt Grant, Robert C. Robbins, MD, Yu Jin, MD, Tim Doyle, PhD, y el Stanford pequeño núcleo de imágenes de animales para la asistencia técnica. Los autores también agradecen AM Bickford, Inc. para el apoyo del equipo de veterinarios. Esta investigación fue financiada por becas de investigación de los Institutos Nacionales de Salud (R01 HL-75774, R01 CA098303, R21 HL085743, 1K12 HL087746), el tabaco de California las enfermedades relacionadas con el Programa de Investigación de la Universidad de California (15IT-0257 y 0169-1514RT) , y el Instituto de Medicina Regenerativa de California (RS1-00183). NH es apoyado por una beca de la Asociación Americana del Corazón. puede Heart Association.

1. Diferenciación de los CES murino en células endoteliales <ol><li> El protocolo para la diferenciación de los CES en las células endoteliales se describe en otro lugar y no es el objetivo de este protocolo 2,3. En pocas palabras, las células pueden diferenciarse, y las células que son positivas para los marcadores endoteliales como el CD31 o caderina del endotelio vascular (VE-cadherina) se purifican por clasificación celular activado por fluorescencia (FACS). </li></ol> 2. La construcción de la fusión de genes reportero doble y transducción de lentivirales <ol><li> Bioluminiscencia puede ser usado para rastrear las células que son modificadas para expresar los genes indicadores, tales como luciferasa de luciérnaga (fluctuaciones). Para esta aplicación, las células contienen fluctuaciones y aumento de proteína verde fluorescente (eGFP) gen de fusión bajo el control de un promotor de la ubiquitina interna. Con el fin de modificar las células, el vector transgénico lentiviral que contiene la clave optimizado elementos genéticos para cumplir con los criterios de bioseguridad, así como una mayor eficiencia de transducción, UFP-FG vector desarrollado en nuestro laboratorio que lleva el gen de fusión fluc-eGFP reportero se puede utilizar para estable transducción de las células después de la diferenciación. Esta construcción de fusión permite que tanto la bioluminiscencia y el seguimiento de la fluorescencia de las células trasplantadas. El procedimiento para la generación de partículas del virus, la transducción y la producción de células marcadas que los genes que expresan reportero se describe en otro 4. </li></ol> 3. El trasplante de células derivadas de CES endotelial a las extremidades inferiores isquémicas <ol><li> Iniciar el procedimiento mediante la elaboración de un ratón que ha sido objeto de isquemia miembro posterior para el trasplante de células. Para ello, coloque el ratón en la cámara de inducción de la anestesia que contiene un 1-3% de isoflurano en oxígeno al 100%, con un caudal de 1L/min. </li><li> Deja el ratón en la cámara de inducción hasta que no responde a los estímulos externos. A continuación, retire el animal de la cámara de inducción. </li><li> Luego, coloque el animal en decúbito supino en la mesa de operaciones y conectarlo a un flujo continuo de 1-3% isoflurano en oxígeno al 100%, con un caudal de 1L/min. </li><li> Limpie la piel de las extremidades inferiores con tres alterna matorrales Betadine y alcohol. </li><li> Una vez que se limpia la piel, obtener millón ESC derivados de las células endoteliales en 30 l de tampón fosfato salino (PBS). La carga de estas células en una aguja de calibre 28. </li><li> Cuando las células están listas, levante suavemente y extender las extremidades inferiores para visualizar mejor la ubicación de los músculos gemelos. Mientras se extiende la pierna, insertar la aguja en la piel en el músculo subyacente. Tenga cuidado de no acercarse a los huesos. Suave y lentamente se inyecta la mezcla de 30 l de células en el gemelo. Para la inyección intramuscular, 30 l está cerca de los límites de volumen que se puede inyectar. Por lo tanto, de calibre 28 jeringas de insulina son preferidos porque, según nuestra experiencia, que eliminan la pérdida de volumen en agujas de jeringas. </li><li> Después de la inyección, vuelva el ratón hacia la jaula de recuperación y controlar de forma continua hasta que despierto. Que el animal pueda recuperarse durante varias horas y luego proceder con la de imágenes de bioluminiscencia in vivo de las células trasplantadas. </li></ol> 4. Bioluminiscencia de imágenes de ESC derivados células endoteliales in vivo <ol><li> El trasplantado células derivadas de CES endothelials fueron modificados para expresar tanto la fluctuaciones y el gen de fusión EGFP bajo el control de un promotor de la ubiquitina interna. Por lo tanto, la bioluminiscencia puede ser usado para rastrear las células dentro de la extremidad posterior isquémica. </li><li> Para comenzar este paso, a su vez en el sistema de imágenes de bioluminiscencia y el software de adquisición de imágenes de vida. A continuación, inicializar el sistema de adquisición y especificar las dimensiones del campo de visión. </li><li> Luego, coloque papel negro mate en la caja de imagen para absorber las emisiones de fondo. </li><li> Una vez que el cuadro de imagen esté listo, coloque el ratón en la cámara de inducción de la anestesia que contiene un 1-3% isoflurano en oxígeno en la salida de 1L/min. Deja el ratón en la cámara de inducción hasta que no responde a los estímulos externos. A continuación, retire el animal de la cámara de inducción. </li><li> Quitar el pelo de ambas extremidades posteriores utilizando una máquina de afeitar eléctrica cuando sea necesario. </li><li> Inyectar 10 L de D-luciferina por gramo de peso corporal en el peritoneo. El D-luciferina se prepara con antelación en las soluciones de filtrado de valores de 15 mg / ml en PBS. </li><li> Una vez que la luciferina se inyecta, el lugar del animal en la caja de imágenes sobre el papel negro en posición supina, conectado a un flujo continuo de isoflurano. </li><li> La colocación de animales en la caja de imagen y la conexión con el isoflurano. </li><li> Comienzan a adquirir las imágenes de 10 a 60 segundos con el fin de determinar un tiempo de exposición óptimo para que la imagen no está saturado. Si la imagen se satura, reducir el tiempo de exposición. Si la señal de bioluminiscencia es muy débil, aumentar el tiempo de exposición. </li><li> Usíng el tiempo de exposición óptimo, continuar adquiriendo imágenes cada 1-3 minutos hasta que la señal llega al máximo y luego se desvanece. Cuando la adquisición se haya completado, guarde el archivo. </li><li> Para analizar los datos, seleccionar las regiones de interés (ROI) que cubren el sitio de la inyección. Como control negativo, un retorno de la inversión similar puede ser seleccionado para la pierna que no funciona. Usando el software, medir la radiación total, que se expresa en unidades de fotones / segundo / cm 2 / estereorradián (p / s / cm 2 / sr), para el rendimiento de la inversión para cada punto de tiempo. El valor máximo debe ser utilizado en los datos finales. Los datos también pueden ser exportados a Excel para su uso futuro. </li><li> Una vez que todos los datos adquiridos, devolver el animal a la jaula de recuperación y seguimiento continuo hasta que la despierta animal. </li><li> Repita este procedimiento para realizar un seguimiento de las células a través del tiempo. </li><li> En un momento de tiempo deseado, el animal puede ser sacrificado para la evaluación de la función del tejido. </li></ol> 5. Resultados representante <img src="/files/ftp_upload/old/1034_2009_1_22_4/figure 1.png" alt="Figura 1" width="600" height="600" /> Una imagen de bioluminiscencia representante de las células trasplantadas en la extremidad posterior izquierda isquémica se muestra en la Figura 1. Durante la adquisición de la bioluminiscencia, la intensidad aumentará con el tiempo, y el valor máximo obtenido durante el transcurso del tiempo debe ser reportado como el valor final.

<ol>
	<li>Niiyama, H., Huang, N. F., Rollins, M., Cooke, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Murine+model+of+hindlimb+ischemia.">Murine model of hindlimb ischemia.</a> JoVE. , (2008).</li><li>Levenberg, S., Golub, J. S., Amit, M., Itsakovitz-Eldor, J., Langer, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endothelial+cells+derived+from+human+embryonic+stem+cells.">Endothelial cells derived from human embryonic stem cells.</a> Proc. Natl. Acad. Sci. U.S.A. 99, 4391-4396 (2002).</li><li>Yamashita, J., Itoh, H., Hirashima, M., Ogawa, M., Nishikawa, S., Yurugi, T., Naito, M., Nakao, K., Nishikawa, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Flk1-positive+cells+derived+from+embryonic+stem+cells+serve+as+vascular+progenitors.">Flk1-positive cells derived from embryonic stem cells serve as vascular progenitors.</a> Nature. 408, 926-926 (2000).</li><li>De, A., Yaghoubi, S. S., Gambhir, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Applications+of+lentiviral+vectors+in+noninvasive+molecular+imaging.">Applications of lentiviral vectors in noninvasive molecular imaging.</a> Methods Mol Biol. 433, 177-202 (2008).</li><li>Niiyama, H., Kai, H., Yamamoto, T., Shimada, T., Sasaki, K., Murohara, T., Egashira, K., Imaizumi, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Roles+of+endogenous+monocyte+chemoattractant+protein-1+in+ischemia-induced+neovascularization.">Roles of endogenous monocyte chemoattractant protein-1 in ischemia-induced neovascularization.</a> J. Am. Coll. Cardiol. 44, 661-666 (2004).</li><li>Cook, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+anatomy+of+the+laboratory+mouse.">The anatomy of the laboratory mouse.</a> , (1976).</li><li>Contag, P. R., Olomu, I. N., Stevenson, D. K., Contag, C. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bioluminescent+indicators+in+living+mammals.">Bioluminescent indicators in living mammals.</a> Nature Med. 4, 245-247 (1998).</li><li>Ray, P., De, A., Min, J. J., Tsien, R. Y., Gambhir, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+tri-fusion+multimodality+reporter+gene+expression+in+living+subjects.">Imaging tri-fusion multimodality reporter gene expression in living subjects.</a> Cancer Res. 64, 1323-1330 (2004).</li><li>Huang, N. F., Lee, R. J., Li, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemical+and+physical+regulation+of+stem+cells+and+progenitor+cells:+potential+for+cardiovascular+tissue+engineering.">Chemical and physical regulation of stem cells and progenitor cells: potential for cardiovascular tissue engineering.</a> Tissue Eng. 13, 1809-1823 (2007).</li><li>Cao, F., Lin, S., Xie, X., Ray, P., Patel, M., Zhang, X., Drukker, M., Dylla, S. J., Connolly, A. J., Chen, X., Weissman, I. L., Gambhir, S. S., Wu, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+visualization+of+embryonic+stem+cell+survival,+proliferation,+and+migration+after+cardiac+delivery.">In vivo visualization of embryonic stem cell survival, proliferation, and migration after cardiac delivery.</a> Circulation. 113, 1005-1114 (2006).</li><li>Wilson, K., Yu, J., Lee, A., Wu, J. C. <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+bioluminescence+reporter+gene+imaging+of+human+embryonic+stem+cells.">In vitro and in vivo bioluminescence reporter gene imaging of human embryonic stem cells.</a> J Vis Exp. , (2008).</li></ol>

CES es una fuente de células prometedoras para el tratamiento de la isquemia tisular, debido a su plasticidad de diferenciación y su capacidad de dar lugar a linajes de células que comprende las tres capas germinales, incluyendo las células endoteliales. Para superar los problemas éticos asociados con la CES, células madre pluripotentes inducidas (CMPi) puede ser una madre pluripotentes alternativa fuente de células que supera las preocupaciones éticas. Además de los CES, las células madre adultas, como las células progenitoras e...

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">	
		
		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Surgical tools</td>
<td>Tool</td>
<td>Fine Science Tools</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Syringe needle</td>
<td>Tool</td>
<td>BD</td>
<td>&nbsp;</td>
<td>28G insulin syringe is preferred</td>
</tr>
<tr>
<td>Phosphate Buffered Saline </td>
<td>Reagent</td>
<td>Invitrogen</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>D-luciferin</td>
<td>Reagent</td>
<td>Biosynth International, Inc</td>
<td>&nbsp;</td>
<td>Prepare D-luciferin in advance into filtered stock solutions of 15 mg/mL in PBS</td>
</tr>
<tr>
<td>IVIS 200 Bioluminescence imaging system and acquisition software </td>
<td>Equipment</td>
<td>Xenogen Corporation</td>
<td>&nbsp;</td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

embryonic stem cell-derived endothelial cells for treatment of hindlimb ischemia

Enfermedad arterial periférica (PAD) se debe a un estrechamiento de las arterias periféricas que irrigan sangre oxigenada y nutrientes a las piernas y los pies, esta patología provoca síntomas como la claudicación intermitente (dolor al caminar), dolorosas úlceras isquémicas, o incluso gangrena del miembro en peligro. Se cree generalmente que el endotelio vascular, una monocapa de células endoteliales, que invierte la superficie luminal de los vasos sanguíneos y linfáticos, juega un papel dominante en la homeostasis vascular y la regeneración vascular. Como resultado, las células madre basado en la regeneración del endotelio puede ser un enfoque prometedor para el tratamiento de PAD. En este vídeo, se demuestra el trasplante de células madre embrionarias (ESC)-derivados de las células endoteliales para el tratamiento de la isquemia hindimb unilateral como un modelo de PAD, seguido por el seguimiento no invasivo de homing de las células y la supervivencia de imágenes de bioluminiscencia. Los materiales y procedimientos específicos para la entrega de la celda y las imágenes se describen. Este protocolo sigue a otra publicación en la descripción de la inducción de isquemia extremidades inferiores por Niiyama et al 1.

Watch this Scientific Journal Video about Embryonic Stem Cell-Derived Endothelial Cells for Treatment of Hindlimb Ischemia at JoVE.com

Embryonic Stem Cell-Derived Endothelial Cells for Treatment of Hindlimb Ischemia

El procedimiento quirúrgico para el suministro de células madre embrionarias derivadas de las células endoteliales de las extremidades inferiores isquémicas se demuestra, con no invasiva de seguimiento por imágenes de bioluminiscencia.

Células madre embrionarias-las células endoteliales derivadas de tratamiento de la isquemia Miembro Posterior

Peripheral arterial disease (PAD) results from narrowing of the peripheral arteries that supply oxygenated blood and nutrients to the legs and feet, This ...

embryonic-stem-cell-derived-endothelial-cells-for-treatment-hindlimb

Research

JoVE Journal

Biology

11.7K vistas.  Stanford University. El procedimiento quirúrgico para el suministro de células madre embrionarias derivadas de las células endoteliales de las extremidades inferiores isquémicas se demuestra, con no invasiva de seguimiento por imágenes de bioluminiscencia.

Video: Embryonic Stem Cell-Derived Endothelial Cells for Treatment of Hindlimb Ischemia

Propagation of Human Embryonic Stem (ES) Cells

Propagation of Human Embryonic Stem ES Cells

Propagación de la madre embrionarias humanas (ES) Células

Investigación

Biología

Derivation of Hematopoietic Stem Cells from Murine Embryonic Stem Cells

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

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

Derivación de células madre hematopoyéticas de células madre embrionarias murinas

A stem cell is defined as a cell with the capacity to both self-renew and generate multiple differentiated progeny.  Embryonic stem cells (ESC) are ...

Derivation of Human Embryonic Stem Cells by Immunosurgery

The ability of human embryonic stem cells to self-renew and differentiate into all cell types of 
the body suggests that they hold great promise for both medical applications and as a research 
tool for addressing fundamental questions in development and disease. Here, we provide a 
concise, step-by-step protocol for the derivation of human embryonic stem cells from embryos 
by immunosurgical isolation of the inner cell mass. 


The ability of human embryonic stem cells to self-renew and differentiate into all cell types of 
the body suggests that they hold great promise for both medical applications and as a research 
tool for addressing fundamental questions in development and disease. Here, we provide a 
concise, step-by-step protocol for the derivation of human embryonic stem cells from embryos 
by immunosurgical isolation of the inner cell mass.

Derivación de células estaminales embrionarias humanas por Immunosurgery

The ability of human embryonic stem cells to self-renew and differentiate into all cell types of 
the body suggests that they hold great promise for both ...

Probing for Mitochondrial Complex Activity in Human Embryonic Stem Cells

Mitochondria are cytoplasmic organelles that have a primary role in cellular metabolism and homeostasis, regulation of the cell signaling network, and programmed cell death. Mitochondria produce ATP, regulate the cytoplasmic redox state and Ca2+ balance, catabolize fatty acids, synthesize heme, nucleotides, steroid hormones, amino acids, and help assemble iron-sulfur clusters in proteins. Mitochondria also have an essential role in heat production. Mutations of the mitochondrial genome cause several types of human disorder. The accumulation of mtDNA mutations correlates with aging and is suspected to have an important role in the development of cancer. Due to their vitally important role in all cell types, the function of mitochondria must also be critical for stem cells. Key advances have been made in our understanding of stem cell viability, proliferation, and differentiation capacity. But the functional activity of stem cells, in particular their energy status, was not yet been studied in detail. Almost nothing is known about the mitochondrial properties of human embryonic stem cells (hESCs) and their differentiated precursor progeny. One way to understand and evaluate the role of mitochondria in hESC function and developmental potential is to directly measure the activity of mitochondrial respiratory complexes. Here, we describe high resolution clear native gel electrophoresis and subsequent in gel activity visualization as a method for analyzing the five respiratory chain complexes of hESCs.

In this video, we will show you how the mitochondrial respiratory chain complexes of human embryonic stem cells can be analyzed using in gel activity assays.

Sondeo de la actividad mitocondrial complejo en células estaminales embrionarias humanas

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

Chromatin Immunoprecipitation from Human Embryonic Stem Cells

The functional and structural complexity of the myriad of cells in metazoan organisms arises from a small number of stem cells. Stem cells are characterized by two fundamental properties: self-renewal and multipotency that allows a stem cell to differentiate into virtually any cell type 1. The progression stem cell to differentiated cell is characterized by loss of multipotency, structural and morphological changes and the hierarchic activity of transcription factors and signaling molecules, whose activities establish and maintain cell-type specific gene expression patterns. At the molecular level, cell differentiation involves dynamic changes of the structure and composition of chromatin and the detection of those dynamic changes can provide valuable insights into the functional features of stem cells and the cell differentiation process 2,3. Chromatin is a highly compacted DNA-protein complex that forms when cells package chromosomal DNA with proteins, mainly histones 4. Stemcellness and cell differentiation has been correlated with the presence of specific arrays of regulatory proteins such as epigenetic factors, histone variants, and transcription factors 2,3,5.
 Chromatin immunoprecipitation (ChIP) provides a valuable method to monitor the presence of RNA, proteins, and protein modifications in chromatin 6,7. The comparison of chromatin from different cell types can elucidate dynamic changes in protein-chromatin associations that occur during cell differentiation.
Chromatin immunoprecipitation involves the purification of in vivo cross-linked chromatin. The isolated chromatin is reduced to smaller fragments by enzymatic digestion or mechanical force. Chromatin fragments are precipitated using specific antibodies to target proteins or protein and DNA modifications. The precipitated DNA or RNA is purified and used as a template for PCR or DNA microarray based assays. Prerequisites for a successful ChIP are high quality antibodies to the desired antigen and the availability of chromatin from control cells that do not express the target molecule. ChIP can correlate the presence of proteins, protein and RNA modifications, and RNA with specific target DNA, and depending on the choice of outread tool, detects the association of target molecules at specific target genes or in the context of an entire genome. The comparison of the distribution of proteins in the chromatin of differentiating cells can elucidate the dynamic changes of chromatin composition that coincide with the progression of cells along a cell lineage.

The differentiation of ESC coincides with cell-type specific changes in the structure and composition of chromatin. The detection of those changes provides valuable insights into the mechanisms that define stemcellness and cell differentiation. Chromatin immunoprecipitation (ChIP) represents a valuable method to dissect the molecular mechanisms underlying stem cell differentiation.

Inmunoprecipitación de la cromatina de células estaminales embrionarias humanas

The functional and structural complexity of the myriad of cells in metazoan organisms arises from a small number of stem cells. Stem cells are ...

Murine Model of Hindlimb Ischemia 

In the United States, peripheral arterial disease (PAD) affects about 10 million individuals, and is also prevalent worldwide. Medical therapies for symptomatic relief are limited. Surgical or endovascular interventions are useful for some individuals, but long-term results are often disappointing. As a result, there is a need for developing new therapies to treat PAD. The murine hindlimb ischemia preparation is a model of PAD, and is useful for testing new therapies. When compared to other models of tissue ischemia such as coronary or cerebral artery ligation, femoral artery ligation provides for a simpler model of ischemic tissue. Other advantages of this model are the ease of access to the femoral artery and low mortality rate. 
In this video, we demonstrate the methodology for the murine model of unilateral hindimb ischemia. The specific materials and procedures for creating and evaluating the model will be described, including the assessment of limb perfusion by laser Doppler imaging. This protocol can also be utilized for the transplantation and non-invasive tracking of cells, which is demonstrated by Huang et al.1.

Murine Model of Hindlimb Ischemia

The surgical procedure for induction of unilateral hindlimb ischemia is demonstrated, with confirmation of ischemia by laser Doppler perfusion imaging.

Modelo murino de isquemia Miembro Posterior

In the United States, peripheral arterial disease (PAD) affects about 10 million individuals, and is also prevalent worldwide.  Medical therapies for ...

Chromosomal Spread Preparation of Human Embryonic Stem Cells for Karyotyping

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

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

Preparación Extienda los cromosomas de las células estaminales embrionarias para cariotipo

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

Isolation and Derivation of Mouse Embryonic Germinal Cells

The ability of embryonic germinal cells (EG) to differentiate into primordial germinal cells (PGCs) and later into gametes during early developmental stages is a perfect model to address our hypothesis about cancer and infertility. This protocol shows how to isolate primordial germinal cells from developing gonads in 10.5-11.5 days post coitum (dpc) mouse embryos.  Developing gonadal ridges from mouse embryos (C57BL6J) were dissociated by mechanical disruption with collagenase, then plated in a mouse embryo fibroblast feeder layer (MEF-CF1) that was previously mitotically inactivated with mitomycin C in the presence of knockout media and supplemented with Leukemia Inhibitor Factor (LIF), basic Fibroblast Growth Factor (bFGF), and Stem Cell Factor (SCF).  Using these optimized methods for PCG identification, isolation, and establishment of culture conditions permits long term cultures of EG cells for more than 40 days.  The embryonic germinal cell lines showed embryonic phenotype and expression of common used markers of the pluripotent state.  Isolation and derivation of germinal cells in culture provide a tool to understand their development in vitro and offer the opportunity to monitor cumulative damage at genetic and epigenetic levels after exposure to oxidative stress.

The ability of embryonic germinal cells to differentiate into primordial germinal cells during early development stages is a perfect model to address our hypothesis about cancer and infertility. This protocol shows how to isolate primordial germinal cells from developing gonads in 10.5-11.5 days post coitum mouse embryos.

El aislamiento y la derivación de células embrionarias de ratón Germinal

The ability of embryonic germinal cells (EG) to differentiate into primordial germinal cells (PGCs) and later into gametes during early developmental ...

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 ...

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 ...