262. Towards derivation of primordial germ cells from murine embryonic stem cells

2005 ◽  
Vol 17 (9) ◽  
pp. 106
Author(s):  
J. C. Young ◽  
V. L. Dias ◽  
M. Holland ◽  
K. L. Loveland
Keyword(s):  
Culture Media ◽  
Es Cells ◽  
Primordial Germ Cells ◽  
Primordial Germ Cell ◽  
Embryonic Stem ◽  
Embryoid Bodies ◽  
Lineage Specification ◽  
Signalling Molecules

The process of primordial germ cell (PGC) specification begins at the earliest stages of murine embryogenesis. The mechanisms underlying this process are the strong instructive cues generated by the extra-embryonic ectoderm, which, via ligand-receptor signalling in the visceral endoderm, activate pathways in the proximal epiblast to induce the PGC phenotype. We have subjected murine embryonic stem (ES) cells to similar cues in order to drive PGC lineage specification in vitro. ES cells were differentiated as aggregates (embryoid bodies (EBs)), a process that is thought to recapitulate the early stages of embryogenesis by providing an environment conducive to the spontaneous emergence of multiple cell lineages. To date, we have shown that EBs can also support the spontaneous emergence of cells expressing PGC markers. Expression analysis was performed on EBs from 1 to 30 days in culture. PGC markers, including nanog, dazl, fragilis, stella and SSEA1, are expressed in undifferentiated ES cells, but rapidly become undetectable in EBs as the constituent ES cells undergo differentiation. The spontaneous emergence of cells expressing these markers occurred only following long-term EB culture. This indicates a lag in the signalling normally required for PGC specification. In vivo, the lack of BMP4, its receptor (ALK-2) or downstream signalling molecules (Smad 1 and 5), results in the absence of PGCs in embryos. Therefore, in order to enhance PGC specification in our in vitro system, we have added BMP4 into the culture media. Under these conditions, the emergence of cells expressing PGC markers occurs at both an apparently higher efficiency and in a shorter time period. This suggests that BMP4 response pathways are present within the EB context and, when activated, can direct PGC specification. Thus, by recapitulating an in vivo physical and biochemical environment, we are able to direct PGC lineage specification in vitro.

scholarly journals Development of Mouse Embryonic Stem (ES) Cells: IV Differentiation to Mature T and B Lymphocytes after Implantation of Embryoid Bodies Into Nude Mice

1995 ◽  
Vol 4 (2) ◽  
pp. 79-84 ◽  
Author(s):  
Una Chen ◽  
Hoyan Mok
Keyword(s):  
T Cells ◽  
B Cells ◽  
Nude Mice ◽  
Fetal Liver ◽  
Es Cells ◽  
Embryonic Stem ◽  
Embryoid Bodies ◽  
Lymphoid Cells

Mouse embryonic stem (ES) cells in culture can differentiate into late stages of many lineage-committed precursor cells. Under appropriate organ-culture conditions, ES cels differentiate into lymphoidlike cells at a stage equivalent to lymphoid cells found in fetal liver. These hematopoietic precursors are located in cup-shaped structures found in some embryoid bodies; we called such embryoid bodies “ES fetuses.” In this study, we have followed the maturation of hematopoietic cells after implantation of ES fetuses into nude mice for 3 weeks. ES-cell-derived lymphoid cells-pre-B cells, mature B cells, and mature T cells were found in all lymphoid organs. Interestingly, there was also an increase of T cells of host origin. Because native nude mouse lack thymus, these T cells might be educated by thymuslike epithelium generated from ES fetuses. Practical applications of this combinedin vitroandin vivosystem are discussed.

scholarly journals In vivo and in vitro differentiation of male germ cells in the mouse

Reproduction ◽  
2004 ◽  
Vol 128 (2) ◽  
pp. 147-152 ◽  
Author(s):  
Orly Lacham-Kaplan
Keyword(s):  
Stem Cells ◽  
Germ Cell ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Embryonic Stem ◽  
Embryoid Bodies ◽  
Cellular Interactions ◽  
Germ Cell Differentiation

Primordial germ cells appear in the embryo at about day 7 after coitum. They proliferate and migrate towards the genital ridge. Once there, they undergo differentiation into germ stem cells, known as ‘A spermatogonia’. These cells are the foundation of spermatogenesis. A spermatogonia commit to spermatogenesis, stay undifferentiated or degenerate. The differentiation of primordial germ cells to migratory, postmigratory and germ stem cells is dependent on gene expression and cellular interactions. Some of the genes that play a crucial role in germ cell differentiation are Steel, c-Kit, VASA, DAZL, fragilis, miwi, mili, mil1 and mil2. Their expression is stage specific, therefore allowing solid identification of germ cells at different developmental phases. In addition to the expression of these genes, other markers associated with germ cell development are nonspecific alkaline phosphatase activity, the stage specific embryonic antigen, the transcription factor Oct3/4 and β1- and α6-integrins. Commitment of cells to primordial germ cells and to A spermatogonia is also dependent on induction by the bone morphogenetic protein (BMP)-4. With this knowledge, researchers were able to isolate germ stem cells from embryonic stem cell-derived embryoid bodies, and drive these into gametes either in vivo or in vitro. Although no viable embryos were obtained from these gametes, the prospects are that this goal is not too far from being accomplished.

scholarly journals Generation of embryonic stem cell lines from mouse blastocysts developed in vivo and in vitro: relation to Oct-4 expression

Reproduction ◽  
2006 ◽  
Vol 132 (1) ◽  
pp. 59-66 ◽  
Author(s):  
S Tielens ◽  
B Verhasselt ◽  
J Liu ◽  
M Dhont ◽  
J Van Der Elst ◽  
...  
Keyword(s):  
Cell Lines ◽  
Inner Cell Mass ◽  
Es Cells ◽  
Cell Mass ◽  
Embryonic Stem ◽  
Embryoid Bodies ◽  
Differentiation Potential ◽  
Stem Cell Lines

Embryonic stem (ES) cells are the source of all embryonic germ layer tissues. Oct-4 is essential for their pluripotency. Sincein vitroculture may influence Oct-4 expression, we investigated to what extent blastocysts culturedin vitrofrom the zygote stage are capable of expressing Oct-4 and generating ES cell lines. We comparedin vivowithin vitroderived blastocysts from B6D2 mice with regard to Oct-4 expression in inner cell mass (ICM) outgrowths and blastocysts. ES cells were characterized by immunostaining for alkaline phosphatase (ALP), stage-specific embryonic antigen-1 (SSEA-1) and Oct-4. Embryoid bodies were made to evaluate the ES cells’ differentiation potential. ICM outgrowths were immunostained for Oct-4 after 6 days in culture. A quantitative real-time PCR assay was performed on individual blastocysts. Of thein vitroderived blastocysts, 17% gave rise to ES cells vs 38% of thein vivoblastocysts. Six-day old outgrowths fromin vivodeveloped blastocysts expressed Oct-4 in 55% of the cases vs 31% of thein vitroderived blastocysts. The amount of Oct-4 mRNA was significantly higher for freshly collectedin vivoblastocysts compared toin vitrocultured blastocysts.In vitrocultured mouse blastocysts retain the capacity to express Oct-4 and to generate ES cells, be it to a lower level thanin vivoblastocysts.

scholarly journals Induction of Pluripotency in Adult Equine Fibroblasts without c-MYC

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Khodadad Khodadadi ◽  
Huseyin Sumer ◽  
Maryam Pashaiasl ◽  
Susan Lim ◽  
Mark Williamson ◽  
...  
Keyword(s):  
Cell Lines ◽  
Es Cells ◽  
Embryonic Stem ◽  
Histochemical Staining ◽  
Chromosome Count ◽  
Embryoid Bodies ◽  
Retroviral Transduction

Despite tremendous efforts on isolation of pluripotent equine embryonic stem (ES) cells, to date there are few reports about successful isolation of ESCs and no report ofin vivodifferentiation of this important companion species. We report the induction of pluripotency in adult equine fibroblasts via retroviral transduction with three transcription factors usingOCT4, SOX2, andKLF4in the absence of c-MYC. The cell lines were maintained beyond 27 passages (more than 11 months) and characterized. The equine iPS (EiPS) cells stained positive for alkaline phosphatase by histochemical staining and expressed OCT4, NANOG, SSEA1, and SSEA4. Gene expression analysis of the cells showed the expression ofOCT4, SOX2 NANOG, andSTAT3. The cell lines retained a euploid chromosome count of 64 after long-term culture cryopreservation. The EiPS demonstrated differentiation capacity for the three embryonic germ layers bothin vitroby embryoid bodies (EBs) formation andin vivoby teratoma formation. In conclusion, we report the derivation of iPS cells from equine adult fibroblasts and long-term maintenance using either of the three reprogramming factors.

Brachyury - a gene affecting mouse gastrulation and early organogenesis

Development ◽  
1992 ◽  
Vol 116 (Supplement) ◽  
pp. 157-165 ◽  
Author(s):  
R. S. P. Beddington ◽  
P. Rashbass ◽  
V. Wilson
Keyword(s):  
Es Cells ◽  
Embryonic Stem ◽  
Primitive Streak ◽  
Coat Colour ◽  
Es Cell ◽  
Wild Type ◽  
Mesoderm Cell ◽  
Rostrocaudal Axis

Mouse embryos that are homozygous for the Brachyury (T) deletion die at mid-gestation. They have prominent defects in the notochord, the allantois and the primitive streak. Expression of the T gene commences at the onset of gastrulation and is restricted to the primitive streak, mesoderm emerging from the streak, the head process and the notochord. Genetic evidence has suggested that there may be an increasing demand for T gene function along the rostrocaudal axis. Experiments reported here indicate that this may not be the case. Instead, the gradient in severity of the T defect may be caused by defective mesoderm cell movements, which result in a progressive accumulation of mesoderm cells near the primitive streak. Embryonic stem (ES) cells which are homozygous for the T deletion have been isolated and their differentiation in vitro and in vivo compared with that of heterozygous and wild-type ES cell lines. In +/+ ↔ T/T ES cell chimeras the Brachyury phenotype is not rescued by the presence of wild-type cells and high level chimeras show most of the features characteristic of intact T/T mutants. A few offspring from blastocysts injected with T/T ES cells have been born, several of which had greatly reduced or abnormal tails. However, little or no ES cell contribution was detectable in these animals, either as coat colour pigmentation or by isozyme analysis. Inspection of potential +/+ ↔ T/T ES cell chimeras on the 11th or 12th day of gestation, stages later than that at which intact T/T mutants die, revealed the presence of chimeras with caudal defects. These chimeras displayed a gradient of ES cell colonisation along the rostrocaudal axis with increased colonisation of caudal regions. In addition, the extent of chimerism in ectodermal tissues (which do not invaginate during gastrulation) tended to be higher than that in mesodermal tissues (which are derived from cells invaginating through the primitive streak). These results suggest that nascent mesoderm cells lacking the T gene are compromised in their ability to move away from the primitive streak. This indicates that one function of the T genemay be to regulate cell adhesion or cell motility properties in mesoderm cells. Wild-type cells in +/+ ↔ T/T chimeras appear to move normally to populate trunk and head mesoderm, suggesting that the reduced motility in T/T cells is a cell autonomous defect

Biophysical stimulation for in vitro engineering of functional cardiac tissues

2017 ◽  
Vol 131 (13) ◽  
pp. 1393-1404 ◽  
Author(s):  
Anastasia Korolj ◽  
Erika Yan Wang ◽  
Robert A. Civitarese ◽  
Milica Radisic
Keyword(s):  
Cardiac Tissue ◽  
Culture Media ◽  
Culture Conditions ◽  
Lineage Specification ◽  
Cardiac Tissues ◽  
Cardiac Lineage ◽  
And Function ◽  
Tissue Models

Engineering functional cardiac tissues remains an ongoing significant challenge due to the complexity of the native environment. However, our growing understanding of key parameters of the in vivo cardiac microenvironment and our ability to replicate those parameters in vitro are resulting in the development of increasingly sophisticated models of engineered cardiac tissues (ECT). This review examines some of the most relevant parameters that may be applied in culture leading to higher fidelity cardiac tissue models. These include the biochemical composition of culture media and cardiac lineage specification, co-culture conditions, electrical and mechanical stimulation, and the application of hydrogels, various biomaterials, and scaffolds. The review will also summarize some of the recent functional human tissue models that have been developed for in vivo and in vitro applications. Ultimately, the creation of sophisticated ECT that replicate native structure and function will be instrumental in advancing cell-based therapeutics and in providing advanced models for drug discovery and testing.

scholarly journals Generation and Characterization of Smac/DIABLO-Deficient Mice

2002 ◽  
Vol 22 (10) ◽  
pp. 3509-3517 ◽  
Author(s):  
Hitoshi Okada ◽  
Woong-Kyung Suh ◽  
Jianping Jin ◽  
Minna Woo ◽  
Chunying Du ◽  
...  
Keyword(s):  
Physiological Function ◽  
Es Cells ◽  
Embryonic Stem ◽  
Caspase Activation ◽  
Proapoptotic Protein ◽  
Apoptosis Proteins ◽  
Deficient Mice

ABSTRACT The mitochondrial proapoptotic protein Smac/DIABLO has recently been shown to potentiate apoptosis by counteracting the antiapoptotic function of the inhibitor of apoptosis proteins (IAPs). In response to apoptotic stimuli, Smac is released into the cytosol and promotes caspase activation by binding to IAPs, thereby blocking their function. These observations have suggested that Smac is a new regulator of apoptosis. To better understand the physiological function of Smac in normal cells, we generated Smac-deficient (Smac−/− ) mice by using homologous recombination in embryonic stem (ES) cells. Smac−/− mice were viable, grew, and matured normally and did not show any histological abnormalities. Although the cleavage in vitro of procaspase-3 was inhibited in lysates of Smac−/− cells, all types of cultured Smac−/− cells tested responded normally to all apoptotic stimuli applied. There were also no detectable differences in Fas-mediated apoptosis in the liver in vivo. Our data strongly suggest the existence of a redundant molecule or molecules capable of compensating for a loss of Smac function.

Abstract 1457: IGFBP-4-Mediated Wnt Inhibition is Required for Cardiac Myogenesis

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Weidong Zhu ◽  
Ichiro Shiojima ◽  
Li Zhi ◽  
Hiroyuki Ikeda ◽  
Masashi Yoshida ◽  
...  
Keyword(s):  
Growth Factor ◽  
Wnt Signaling ◽  
Heart Diseases ◽  
Es Cells ◽  
Embryonic Stem ◽  
Cardiomyocyte Differentiation ◽  
Canonical Wnt Signaling ◽  
Canonical Wnt

Insulin-like growth factor-binding proteins (IGFBPs) bind to and modulate the actions of insulin-like growth factors (IGFs). Although some of the effects of IGFBPs appear to be independent of IGFs, the precise mechanisms of IGF-independent actions of IGFBPs are largely unknown. In this study we demonstrate that IGFBP-4 is a novel cardiogenic growth factor. IGFBP-4 enhanced cardiomyocyte differentiation of P19CL6 embryonal carcinoma cells and embryonic stem (ES) cells in vitro. Conversely, siRNA-mediated knockdown of IGFBP-4 in P19CL6 cells or ES cells attenuated cardiomyocyte differentiation, and morpholino-mediated knockdown of IGFBP-4 in Xenopus embryos resulted in severe cardiac defects and complete absence of the heart in extreme cases. We also demonstrate that the cardiogenic effect of IGFBP-4 was independent of its IGF-binding activity but was mediated by the inhibitory effect on canonical Wnt signaling. IGFBP-4 physically interacted with a Wnt receptor Frizzled 8 (Frz8) and a Wnt co-receptor low-density lipoprotein receptor-related protein 6 (LRP6), and inhibited the binding of Wnt3A to Frz8 and LRP6. Moreover, the cardiogenic defects induced by IGFBP-4 knockdown both in vitro and in vivo was rescued by simultaneous inhibition of canonical Wnt signaling. Thus, IGFBP-4 is an inhibitor of the canonical Wnt signaling, and Wnt inhibition by IGFBP-4 is required for cardiogenesis. The present study provides a molecular link between IGF signaling and Wnt signaling, and suggests that IGFBP-4 may be a novel therapeutic target for heart diseases.

Altered imprinted gene methylation and expression in completely ES cell-derived mouse fetuses: association with aberrant phenotypes

Development ◽  
1998 ◽  
Vol 125 (12) ◽  
pp. 2273-2282 ◽  
Author(s):  
W. Dean ◽  
L. Bowden ◽  
A. Aitchison ◽  
J. Klose ◽  
T. Moore ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Es Cells ◽  
Embryonic Stem ◽  
Upstream Region ◽  
Imprinted Genes ◽  
Epigenetic Alterations ◽  
Es Cell ◽  
Biallelic Expression

In vitro manipulation of preimplantation mammalian embryos can influence differentiation and growth at later stages of development. In the mouse, culture of embryonic stem (ES) cells affects their totipotency and may give rise to fetal abnormalities. To investigate whether this is associated with epigenetic alterations in imprinted genes, we analysed two maternally expressed genes (Igf2r, H19) and two paternally expressed genes (Igf2, U2af1-rs1) in ES cells and in completely ES cell-derived fetuses. Altered allelic methylation patterns were detected in all four genes, and these were consistently associated with allelic changes in gene expression. All the methylation changes that had arisen in the ES cells persisted on in vivo differentiation to fetal stages. Alterations included loss of methylation with biallelic expression of U2af1-rs1, maternal methylation and predominantly maternal expression of Igf2, and biallelic methylation and expression of Igf2r. In many of the ES fetuses, the levels of H19 expression were strongly reduced, and this biallelic repression was associated with biallellic methylation of the H19 upstream region. Surprisingly, biallelic H19 repression was not associated with equal levels of Igf2 expression from both parental chromosomes, but rather with a strong activation of the maternal Igf2 allele. ES fetuses derived from two of the four ES lines appeared developmentally compromised, with polyhydramnios, poor mandible development and interstitial bleeding and, in chimeric fetuses, the degree of chimerism correlated with increased fetal mass. Our study establishes a model for how early embryonic epigenetic alterations in imprinted genes persist to later developmental stages, and are associated with aberrant phenotypes.

The active migration of Drosophila primordial germ cells

Development ◽  
1995 ◽  
Vol 121 (11) ◽  
pp. 3495-3503 ◽  
Author(s):  
M.K. Jaglarz ◽  
K.R. Howard
Keyword(s):  
Primary Culture ◽  
Germ Cells ◽  
Actin Polymerization ◽  
Primordial Germ Cells ◽  
Primordial Germ Cell ◽  
Cell Polarization ◽  
Germ Cell Migration ◽  
Oriented Movement

We describe our analysis of primordial germ cell migration in Drosophila wild-type and mutant embryos using high resolution microscopy and primary culture in vitro. During migratory events the germ cells form transient interactions with each other and surrounding somatic cells. Both in vivo and in vitro they extend pseudopodia and the accompanying changes in the cytoskeleton suggest that actin polymerization drives these movements. These cellular events occur from the end of the blastoderm stage and are regulated by environmental cues. We show that the vital transepithelial migration allowing exit from the gut primordium and passage into the interior of the embryo is facilitated by changes in the structure of this epithelium. Migrating germ cells extend processes in different directions. This phenomenon also occurs in primary culture where the cells move in an unoriented fashion at substratum concentration-dependent rates. In vivo this migration is oriented leading germ cells to the gonadal mesoderm. We suggest that this guidance involves stabilization of states of an intrinsic cellular oscillator resulting in cell polarization and oriented movement.

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