391 A COMPARATIVE GENE EXPRESSION ANALYSIS BETWEEN SHEEP EARLY EMBRYONIC DEVELOPMENT AND PUTATIVE EMBRYONIC STEM CELLS

2010 ◽  
Vol 22 (1) ◽  
pp. 352
Author(s):  
B. M. Murray ◽  
S. Schmoelzl ◽  
N. M. Andronicos ◽  
J. R. Hill ◽  
P. J. Verma ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Embryonic Stem Cells ◽  
In Vitro Culture ◽  
Culture Media ◽  
Embryonic Stem ◽  
Oct4 Expression ◽  
Pluripotency Markers

The optimization of culture media to support the isolation of embryonic stem cells relies on methods to monitor whether the pluripotent state of the cultured cells has been maintained. We developed a panel of gene expression assays that allowed us to correlate molecular measures of pluripotency or lineage differentiation with a developmental time course. By conducting quantitative PCR analysis of sheep embryos over Day 6.5 to 24 and sheep inner cell mass (ICM) cells cultured over 25 days, we tested whether culture media designed to inhibit differentiation are able to maintain sheep ICM cells in a pluripotent state. Briefly, embryos were collected from Merino ewes (n = 50, 3 years) at Day 6.5, 12, 16, 20, and 24 post-AI. Embryos were collected from the dissected uterine tracts of slaughtered ewes, excluding Day 6.5 blastocysts, which were surgically recovered from superovulated ewes. For the in vitro culture, Day 6.5 ICM cells were isolated by immunosurgery and cultured on mitomycin-C-treated mouse embryonic fibroblasts in an inhibitor-based medium (3i, based on Ying Q-L et al. 2008 Nature 453, 519-523). Real-time PCR assays for pluripotency (OCT4, SOX2, NANOG) and differentiation (ectodermal: FGF5, PAX6; endodermal: GATA4, GATA6, Somatostatin; mesodermal: BMP4, Connexin40) of sheep candidate genes were conducted on cDNA prepared from these samples and normalized against the reference genes RPL19 and RPS26. In in vivo embryos, pluripotency markers OCT4, SOX2, and NANOG all decreased between Day 6.5 and Day 20, although OCT4 expression spiked around Day 16. More interestingly, pluripotency expression decreased during in vitro culture, with NANOG expression completely lost by passage 2 at Day 11 and OCT4 expression at an equivalent Day 24 embryo basal level by Day 14. The endodermal markers GATA6 and GATA4 decreased between Day 6.5 and Day 12, respectively, although in vitro GATA4 was only expressed once at Day 7. In vivo FGF5 and both PAX6 and Somatostatin displayed a delayed onset, increasing expression from Day 16 and 20, respectively, whereas the ectodermal markers were already expressed by Day 7 in vitro. Both mesodermal markers Connexin40 and BMP4 presented minor fold changes in both data sets. In conclusion, this study has verified the primer sets and described a sheep in vivo embryo gene expression profile comprising both pluripotent and differentiation candidates. Furthermore, the decrease of pluripotency markers together with the appearance of differentiation markers during in vitro culture of ICM cells suggest that culturing ICM cells in 3i media is not sufficient to maintain a sheep-specific pluripotent population of cells. Therefore, future studies will be aimed at manipulating the current in vitro system to focus on maintaining pluripotent genes such as NANOG and OCT4 in culture.

134. DIFFERENTIATION OF HUMAN EMBRYONIC STEM CELLS TO MULLERIAN TISSUE

2010 ◽  
Vol 22 (9) ◽  
pp. 52
Author(s):  
L. Ye ◽  
R. Mayberry ◽  
E. Stanley ◽  
A. Elefanty ◽  
C. Gargett
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Human Embryonic Stem Cells ◽  
Embryonic Stem ◽  
Mullerian Duct ◽  
Human Uterus ◽  
Müllerian Duct

The human uterus develops from the distal Mullerian Duct, a derivative of the mesoderm germ layer. Unlike other mammalian species (eg. mouse) the endometrium of the human uterus develops prenatally during gestation. Little is known about the developmental process involved. A better understanding of human endometrial development may shed light on the mechanisms involved in endometrial regeneration and pathogenesis of adult proliferative endometrial diseases. Mouse neonatal uterine mesenchyme (mNUM) is inductive and can maintain the phenotype of normal adult human endometrial epithelial cells [1]. Both adult human endometrial stroma and neonatal mouse endometrial mesenchyme secrete growth factors of the TGF-beta family including BMPs which have been shown to play an important role in differentiation of human embryonic stem cells (HESC) [2, 3]. Hypothesis: mNUM will direct differentiation of HESC to form Mullerian Duct-like epithelium. Aim: to investigate the role of mNUM in differentiating HESC in vitro and in vivo using A tissue recombination technique. Method: Embryoid bodies (EB) were formed from GFP labelled HESC (ENVY) and GFP-MIXL1 HESC reporter line [4, 5] and recombined with 2 × 0.5 mm pieces of day 1 epithelial cell-free mNUM. Recombinant tissues were either harvested for gene expression analysis or grafted under the kidney capsule of NOD/SCID mice. Results: We found by qRT-PCR that mNUM induces HESC to form mesendoderm/mesoderm progenitors in vitro, obligate intermediates of the developing Mullerian Duct. After further incubation in vivo under the guidance of mNUM, HESC differentiated to form duct-like structures comprising mesoepithelial cells that co-expressed several key developmental proteins of the Mullerian Duct including Emx2, Pax2, Hoxa10, CA125, and also intermediate filament markers such as CK8/18, Vimentin (n = 8). Conclusion: Our study demonstrated for the first time that mNUM can direct HESC to form a mesodermally derived epithelium that is Mullerian Duct-like, providing a novel model for studying human uterine development. (1) Kurita T, et al., The activation function-1 domain of estrogen receptor alpha in uterine stromal cells is required for mouse but not human uterine epithelial response to estrogen. Differentiation, 2005. 73(6): 313–22.(2) Hu J, Gray CA, Spencer TE, Gene expression profiling of neonatal mouse uterine development. Biol Reprod, 2004. 70(6): 1870–6.(3) Stoikos CJ, et al., A distinct cohort of the TGFbeta superfamily members expressed in human endometrium regulate decidualization. Hum Reprod, 2008. 23(6): 1447–56.(4) Davis R, et al., Targeting a GFP reporter gene to the MIXL1 locus of human embryonic stem cells identifies human primitive streak-like cells and enables isolation of primitive hematopoietic precursors. Blood, 2008. 111(4): 1876–84.(5) Costa M, et al., The hESC line Envy expresses high levels of GFP in all differentiated progeny. Nat Methods, 2005. 2(4): 259–60.

383 IDENTIFICATION OF PLURIPOTENCY MARKERS IN SWINE EMBRYOS

2010 ◽  
Vol 22 (1) ◽  
pp. 348
Author(s):  
F. R. O. de Barros ◽  
M. D. Goissis ◽  
M. G. Marques ◽  
M. I. Giassetti ◽  
F. F. Paula-Lopes ◽  
...  
Keyword(s):  
Stem Cells ◽  
In Vitro Culture ◽  
Genetic Manipulation ◽  
Embryonic Stem ◽  
Culture Conditions ◽  
Rabbit Serum ◽  
Embryonic Fibroblasts ◽  
Pluripotency Markers

Embryonic stem cells (ESC) are a useful tool for studying embryonic development, cell differentiation, and genetic manipulation. Moreover, these cells can be applied in cell-based therapies and in vitro organogenesis. The research conducted with human ESC has generated many ethical, moral, and religious considerations by scientists and laymen alike. Therefore, an animal model such as the pig (Sus scrofa) is valuable in overcoming such hurdles because this species holds physiologic parameters similar to humans. In spite of the great biomedical potential of ESC, many difficulties have been faced in maintaining these cells in a pluripotent state in vitro. For this reason, studies to elucidate the mechanisms of in vitro maintenance of undifferentiated ESC are needed to improve the culture of these cells. The objectives of this study were (1) to isolate ESC from in vitro- and in vivo-produced swine blastocysts; (2) to compare 2 in vitro culture conditions to maintain isolated inner cell masses (ICM), murine embryonic fibroblasts (MEF), or Matrigel; and (3) to identify and to compare the expression of the pluripotency markers Nanog, Sox2, and FoxD3 at ESC and in vitro- and in vivo-produced swine blastocysts. In this manner, swine blastocysts were obtained by in vitro maturation and fertilization of oocytes from ovaries collected in abattoirs. Embryos were in vitro cultured for 7 days until blastocyst stage. In addition, in vivo-produced blastocysts were obtained by superovulation followed by AI of gilts (150 days of age). Embryos were collected by post-mortem uterus flushing 5 days after ovulation. In vitro- and in vivo-produced blastocysts were submitted to immunosurgery to isolate the ICM. Briefly, zona pellucida was digested with pronase solution, and embryos were incubated with anti-swine rabbit serum to remove trophoectoderm cells and with guinea-pig complement serum. Resultant ICM (14 and 66 ICM from in vitro- and in vivo-produced blastocysts, respectively) were cultured in stem cells media (GMEM added by 15% FCS, 0.1 mM β-mercaptoethanol, 1% nonessential amino acids, and 4 ng mL-1 of basic fibroblast growth factor) over monolayer of irradiated mouse embryonic fibroblasts (MEF) or Matrigel for 3 weeks. No difference was observed between the in vitro culture conditions (MEF and Matrigel) on isolated ICM adhesion. In addition, no difference was verified between in vitro- and in vivo-produced blastocysts on adhesion of cultured ICM. However, no swine ESC was obtained. Gene expression analysis was performed only with whole in vitro- and in vivo-produced blastocysts. Results showed that Nanog and Sox2 were less expressed in in vitro-produced blastocysts. However, the expression of FoxD3, demonstrated in this study for the first time, was similar between groups. Because no ESC lineage was obtained in swine until now, we believe this species has different requirements compared with murine and human. Therefore, more studies are necessary to establish protocols to isolate porcine ESC. Acknowledgments are given to FAPESP (processes 06/58507-0 and 07/51732-0).

scholarly journals Polycomb enables primitive endoderm lineage priming in embryonic stem cells

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Robert S Illingworth ◽  
Jurriaan J Hölzenspies ◽  
Fabian V Roske ◽  
Wendy A Bickmore ◽  
Joshua M Brickman
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Embryonic Stem ◽  
Developmental Trajectory ◽  
Primitive Endoderm ◽  
Dynamic Changes ◽  
Lineage Priming

Mouse embryonic stem cells (ESCs), like the blastocyst from which they are derived, contain precursors of the epiblast (Epi) and primitive endoderm (PrEn) lineages. While transient in vivo, these precursor populations readily interconvert in vitro. We show that altered transcription is the driver of these coordinated changes, known as lineage priming, in a process that exploits novel polycomb activities. We find that intragenic levels of the polycomb mark H3K27me3 anti-correlate with changes in transcription, irrespective of the gene’s developmental trajectory or identity as a polycomb target. In contrast, promoter proximal H3K27me3 is markedly higher for PrEn priming genes. Consequently, depletion of this modification stimulates the degree to which ESCs are primed towards PrEn when challenged to differentiate, but has little effect on gene expression in self-renewing ESC culture. These observations link polycomb with dynamic changes in transcription and stalled lineage commitment, allowing cells to explore alternative choices prior to a definitive decision.

scholarly journals In Vitro Corticogenesis from Embryonic Stem Cells Recapitulates the In Vivo Epigenetic Control of Imprinted Gene Expression

2016 ◽  
pp. bhw102 ◽  
Author(s):  
Tristan Bouschet ◽  
Emeric Dubois ◽  
Christelle Reynès ◽  
Satya K. Kota ◽  
Stéphanie Rialle ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Embryonic Stem ◽  
Imprinted Gene ◽  
Epigenetic Control

scholarly journals Dickkopf Wnt signaling pathway inhibitor 1 regulates the differentiation of mouse embryonic stem cells in vitro and in vivo

2015 ◽  
Vol 13 (1) ◽  
pp. 720-730 ◽  
Author(s):  
LIPING OU ◽  
LIAOQIONG FANG ◽  
HEJING TANG ◽  
HAI QIAO ◽  
XIAOMEI ZHANG ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Wnt Signaling ◽  
Signaling Pathway ◽  
Wnt Signaling Pathway ◽  
Embryonic Stem ◽  
Mouse Embryonic Stem Cells

Derivation of human embryonic stem cell lines after blastocyst microsurgery

2010 ◽  
Vol 88 (3) ◽  
pp. 479-490 ◽  
Author(s):  
Guoliang Meng ◽  
Shiying Liu ◽  
Xiangyun Li ◽  
Roman Krawetz ◽  
Derrick E. Rancourt
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Cell Lines ◽  
Clinical Medicine ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Embryonic Stem ◽  
Hesc Lines

Embryonic stem cells (ESCs) are derived from the inner cell mass (ICM) of the blastocyst. Because of their ability to differentiate into a variety of cell types, human embryonic stem cells (hESCs) provide an unlimited source of cells for clinical medicine and have begun to be used in clinical trials. Presently, although several hundred hESC lines are available in the word, only few have been widely used in basic and applied research. More and more hESC lines with differing genetic backgrounds are required for establishing a bank of hESCs. Here, we report the first Canadian hESC lines to be generated from cryopreserved embryos and we discuss how we navigated through the Canadian regulatory process. The cryopreserved human zygotes used in this study were cultured to the blastocyst stage, and used to isolate ICM via microsurgery. Unlike previous microsurgery methods, which use specialized glass or steel needles, our method conveniently uses syringe needles for the isolation of ICM and subsequent hESC lines. ICM were cultured on MEF feeders in medium containing FBS or serum replacer (SR). Resulting outgrowths were isolated, cut into several cell clumps, and transferred onto fresh feeders. After more than 30 passages, the two hESC lines established using this method exhibited normal morphology, karyotype, and growth rate. Moreover, they stained positively for a variety of pluripotency markers and could be differentiated both in vitro and in vivo. Both cell lines could be maintained under a variety of culture conditions, including xeno-free conditions we have previously described. We suggest that this microsurgical approach may be conducive to deriving xeno-free hESC lines when outgrown on xeno-free human foreskin fibroblast feeders.

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