PWD est soutenu par une bourse des Instituts de recherche en santé du Canada (IRSC) et une subvention des IRSC pour Gerald M. Kidder à l&#39;Université Western. L&#39;auteur tient également à remercier Julang Li de l&#39;Université de Guelph pour aider à l&#39;élaboration du protocole présenté ici.

1. Médias Préparation <ol><li> Préparer les médias 2-3 heures à l&#39;avance de l&#39;usage et du lieu avec un bouchon dévissé dans l&#39;incubateur de culture cellulaire où l&#39;expérience aura lieu. Médias utilisés dans le présent protocole: <ol><li> Préparer un milieu de cellules souches constitué de DMEM/F12 supplémenté avec 1 x B27, 40 ng / ml de bFGF, et 20 ng / ml d&#39;EGF. </li><li> Préparer milieu de différenciation des cellules germinales composé de M199 additionné de 0,05 UI de FSH, 0,03 UI LH, 3 mg / ml de BSA, 5 pl / ml ITS, 0,23 mM de pyruvate de sodium, 1 mg / ml Fetuin et 1 ng / ml d&#39;EGF. Un support de base constitué de tous les additifs, mais en omettant la FSH, LH et FEM peut être préparé et conservé à 4 ° C pendant une semaine. </li></ol></li></ol> 2. Culture cellulaire Préparation souches <ol><li> Isoler les cellules souches de nouveau-nés de souris comme décrit précédemment 12. Utiliser les cellules souches au passage 2-4 dans la différenciation des cellules germinales in vitro. L&#39;efficacité de l&#39;Formation OLC est directement liée à la qualité des cellules souches de départ. Il est préférable de commencer la différenciation dès que la population semble propre et sain qui est généralement aux alentours de passage 2. En outre la culture des cellules souches passage passé 2 affecte négativement l&#39;efficacité de la formation OLC (résultats non publiés). </li><li> 48 h avant d&#39;initier la différenciation de sous-culture les cellules souches. Retirez tous les agrégats sphériques suspendus cellulaires et les médias usés provenant de la boîte de culture, à l&#39;aide d&#39;une pipette sérologique, et les placer dans un tube de 15 ml. Il est important de ne recueillir que les agrégats sphériques suspendus de cellules et non les cellules attachées au fond du plat qui sont spontanément de différenciation. </li><li> Pellet les cellules à 500 xg pendant 5 min., Jeter le surnageant et remettre en suspension dans 500 ul de milieu de cellules souches frais chauffé à 37 ° C. Pipette doucement les agrégats de dissocier partiellement les cellules. Ne pas agressive pipette la cellules que cela va réduire la viabilité cellulaire. Laver les cellules partiellement dissociés dans 9,5 ml de milieu de cellules souches pré-chauffé frais sur une attache 10 cm boîte de culture bas de la cellule. </li><li> Remettre les cellules à 37 ° C, 5% de CO 2 incubateur de culture cellulaire pendant 48 heures avant le début de la différenciation. </li></ol> 3. Différenciation OLC <ol><li> Avec une pipette sérologique enlever les cellules souches provenant de la boîte de culture et le placer dans un tube de 15 ml, laisser derrière les cellules attachées. Pellet les cellules à 500 xg et remettre en suspension dans 500 pi de PBS stérile. Pipette vigoureuse des cellules en utilisant un large portaient 1.000 pointe ul en amas pas plus grandes que les cellules 10-20. Périodiquement, démonter une petite quantité de cellules, au cours de la dissociation, et vérifiez sous un microscope à lumière blanche pour confirmer cellules agrégées sont en touffes de 10-20 cellules individuelles. Au cours de dissociation va entraîner une diminution de la viabilité cellulaire. </li><li> Ajouter 9,5 ml de PBS aux cellules dissociées et ajouter 15 l de cette suspension cellulaire à un hémocytomètre pour le comptage des cellules. Pellet les cellules à 500 xg pendant 5 min. </li><li> Remettre en suspension les cellules à une concentration de 1.32x10 6 cellules / ml dans le milieu de différenciation. </li><li> Plaque les cellules en ajoutant 500 ul par puits dans un fond plat 24 plat de suspension bien. </li><li> Placer le plat à 24 puits dans un incubateur de culture de cellules à 37 ° C dans 5% de CO 2 pendant 48 heures. Retirer 250 pi de milieu de chaque puits et placer dans un tube de 1,5 ml étiqueté en conséquence. Ajouter 250 pi de milieu de différenciation frais à chaque puits. Centrifugeuse à moyen passé à 500 g pendant 5 min. et jeter le surnageant. Reprendre les cellules sédimentées dans 50 pi de milieu de différenciation frais et revenir à la culture correspondant bien sur la plaque de différenciation. </li><li> Chaque 48 h changer la moitié de la moyenne à 12 jours de différenciation. </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>

Aucun conflit d&#39;intérêt déclaré.

À ce jour LCE fonctionnelles n&#39;ont pas été développé en utilisant un tout essai in vitro. Récemment, une étude réalisée par Hayashi et al. Était capable de produire une descendance de PGC-comme les cellules formées in vitro et in vivo transféré pour le développement 14. A partir de cellules souches embryonnaires ou des cellules pluripotentes induites, ils ont pu former PGC comme des cellules qui, une fois récupérée à la suite transplantation in viv...

Au cours de l&#39;embryogenèse précoce, gamétogénèse se produit à travers une série d&#39;étapes, y compris cellule primordiale de germe (PGC) formation, la migration, et enfin la colonisation des crêtes génitales. Pendant ce temps PGC subissent la prolifération et la différenciation en gamètes de plus en plus matures 1. Le fait que les PGC migrent à partir de la base de l&#39;allantoïde dans l&#39;intestin postérieur de l&#39;embryon et, enfin, le long de la paroi dorsale finalement coloniser les crêtes génitales qui les rend extrêmement difficiles à étudier 2. Malgré les progrès réalisés dans le domaine, les études qui tentent de comprendre la formation PGC et différenciation ont été entravés par leur nombre limité, l&#39;emplacement et la nature migratoire de 3,4. Ces dernières années, les cellules souches embryonnaires ont été montré pour avoir le potentiel pour former des cellules germinales in vitro 5,6. De même, plusieurs cellules souches somatiques ont également été montrés pour avoir le potentiel pour former des cellules germinales Follen raison de culture in vitro 7-11. Récemment cellules souches isolées à partir de peau de souris nouveau-né ont été différenciées in vitro en cellules germinales et des ovocytes comme un stade précoce 12. Au cours de la différenciation du sous-ensemble des cellules souches exprimant Oct4 augmentée et des structures ressemblant à des complexes cumulus-ovocytes ont été formés. L&#39;ovocyte-comme les cellules (LCE) peuvent être ramassés par les cultures et comparés aux ovocytes naturelles. En utilisant cette méthode de mesure culture LCO 40-45 um sont obtenus qui expriment des marqueurs similaires à ovocytes comme Gdf9b, VASA, et DAZL. À ce jour, les LCO résultant demeurent incapables de mûrir ou être fécondé 12. Bien que les LCO restent incapables de fonctionner le protocole utilisé pour former ces LCO peut encore avoir une utilité comme un test pour étudier la formation et le développement des cellules germinales de stade plus précoce dans un système in vitro fermé. La publication originale discuter de la formation de LCO de manièrecellules souches matiques utilisés peau de porc foetal comme source de cellules souches 8. Développant cette étude, les cellules PGC-comme formées très tôt au cours de la différenciation induite ont été montrés à être les précurseurs de la LCE et d&#39;exprimer de tels marqueurs PGC comme OCT4, VASA, STELLA, C-KIT, et DAZL 13. Ces données confirment le potentiel de l&#39;utilisation de ce système pour étudier la formation des cellules germinales et la différenciation in vitro. Le protocole utilisé pour former LCE du nouveau-né peau de la souris sera démontré dans cet article de la vidéo. Ce protocole offre un modèle in vitro pour étudier le développement des cellules germinales qui peuvent fournir un moyen d&#39;élucider les facteurs importants pour leur prolifération et la différenciation in.

<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

Étude de la formation des cellules germinales et la différenciation a toujours été très difficile en raison du faible nombre de cellules et de leur localisation profonde dans les embryons en développement. La disponibilité d&#39;un «fermé» dans le système de base vitro pourrait s&#39;avérer précieuse pour notre compréhension de la gamétogenèse. La formation d&#39;ovocytes-comme les cellules (LCO) à partir de cellules souches somatiques, isolés à partir de peau de souris nouveau-né, a été démontrée et peut être visualisé dans ce protocole vidéo. Les LCE résultant expriment différents marqueurs compatibles avec les ovocytes comme Oct4, Vasa, BMP15, et SCP3. Toutefois, ils demeurent incapables de se soumettre à la maturation ou la fertilisation en raison d&#39;un défaut de terminer la méiose. Ce protocole fournira un système qui est utile pour l&#39;étude de la formation à un stade précoce et la différenciation des cellules germinales en gamètes matures. Au cours de la différenciation précoce du nombre de cellules exprimant Oct4 (cellules germinales potentielles comme) atteint environ 5%, mais a le formation de LCO reste relativement inefficace. Le protocole est relativement simple si des précautions particulières doivent être prises pour assurer la population de la cellule de départ est en bonne santé et à un passage précoce.

Initialement, les cellules se fixent au fond de la boîte de culture et étalées. À 42-72 h dans la différenciation des cellules en suspension OCT4 positifs petit formulaire et prolifèrent (Figure 1A). Peu de temps après la visualisation de ces cellules la majorité disparaît et les cellules attachées va former des agrégats de colonies denses au fond de la culture. Après quelques jours, ces agrégats se détacher de la surface de culture. Dans certains de ces agrégats une grande cellule peut ?...

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

Au cours des dernières années, la formation de cellules germinales en utilisant des méthodes de culture in vitro a été démontrée en utilisant différents types de cellules souches somatiques. Cet article va présenter visuellement la différenciation des cellules souches dérivées de souris nouveau-nés aux cellules ovocyte comme au début.

Différenciation de la peau de souris nouveau-nés des cellules souches dérivées dans les cellules germinales comme<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 vues.  The University of Western Ontario. Au cours des dernières années, la formation de cellules germinales en utilisant des méthodes de culture in vitro a été démontrée en utilisant différents types de cellules souches somatiques. Cet article va présenter visuellement la différenciation des cellules souches dérivées de souris nouveau-nés aux cellules ovocyte comme au début.

Vidéo: 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.

Différenciation in vitro de souris embryonnaires souches (MES) Cellules utilisant la méthode de goutte suspendue

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 ...

Recherche

Biologie

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 différenciation des cellules souches embryonnaires en précurseurs d&#39;oligodendrocytes

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.

Reprogrammation des cellules somatiques humaines dans cellules souches pluripotentes induites (CISP) Utilisation vecteur rétroviral avec la GFP

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

Efficient Differentiation of Mouse Embryonic Stem Cells into Motor Neurons

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

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

Différenciation efficace des cellules souches embryonnaires de souris dans les neurones moteurs

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.

Génération de souris dérivées de cellules souches pluripotentes induites

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.

Induction et analyse des épithéliale à mésenchymateuses transition

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.

Néphrotoxine microinjection dans Zebrafish au Modèle lésion rénale aiguë

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.

Une interface utilisateur graphique pour le suivi assisté par logiciel de la concentration de protéines dans les protrusions cellulaires dynamiques

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-intérieur cellulaire massive Injection de cellules souches embryonnaires conduit à des taux plus élevés de chimérisme

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.

Isolement, prolifération et différenciation des cellules souches adipeuses dérivées du macaque rhésus

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