scholarly journals Effects of extracellular matrices and lectin Dolichos biflorus agglutinin on cell adhesion and self-renewal of bovine gonocytes cultured in vitro

2014 ◽  
Vol 26 (2) ◽  
pp. 268 ◽  
Author(s):  
Sung-Min Kim ◽  
Mayako Fujihara ◽  
Mahesh Sahare ◽  
Naojiro Minami ◽  
Masayasu Yamada ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Germ Cell ◽  
Mammalian Species ◽  
Embryonic Stem ◽  
Specific Gene ◽  
Self Renewal ◽  
Dolichos Biflorus ◽  
Dolichos Biflorus Agglutinin ◽  
Essential Components

Surface molecules of primitive male germ cells, gonocytes, are essential components for regulating cell adhesion and maintaining self-renewal in mammalian species. In domestic animals, the stage-specific glycan epitope α-N-acetylgalactosamine (GalNAc) is recognised by the lectin Dolichos biflorus agglutinin (DBA) and is found on the surface of gonocytes and spermatogonia. Gonocytes from bovine testis formed mouse embryonic stem-like cell colonies on plates that had been coated with DBA or extracellular matrix (ECM) components, such as gelatin (GN), laminin (LN) and poly-L-lysine (PLL). The number of colonies on the DBA-coated plate was significantly higher than that on the GN-, LN- and PLL-coated plates. Pretreating gonocytes with DBA to neutralise the terminal GalNAc residues strongly suppressed colony formation. Furthermore, expression of a germ cell-specific gene and pluripotency-related transcription factors was increased considerably on the DBA-coated plates. These results suggest that the GalNAc residues on gonocytes can recognise precoated DBA on plates and the resulting GalNAc–DBA complexes support germ cell and stem cell potentials of gonocytes in vitro. These glycan complexes, through the GalNAc epitope, may provide a suitable microenvironment for the adhesion and cell proliferation of gonocytes in culture.

scholarly journals Resf1 supports embryonic stem cell self-renewal and effective germline entry

2021 ◽  
Author(s):  
Matus Vojtek ◽  
Ian Chambers
Keyword(s):  
Stem Cells ◽  
Germ Cell ◽  
Germ Line ◽  
Primordial Germ Cell ◽  
Embryonic Stem ◽  
Cell Specification ◽  
Self Renewal ◽  
Downstream Target ◽  
Germ Cell Specification

Retroelement silencing factor 1 (Resf1) interacts with the key regulators of mouse embryonic stem cells (ESCs) Oct4 and Nanog, and its absence results in sterility of mice. However, the function of Resf1 in ESCs and germ line specification is poorly understood. In this study, we used Resf1 knockout cell lines to determine the requirements of RESF1 for ESCs self-renewal and for in vitro specification of ESCs into primordial germ cell-like cells (PGCLCs). We found that deletion of Resf1 in ESCs cultured in serum and LIF reduces self-renewal potential whereas episomal expression of RESF1 has a modest positive effect on ESC self-renewal. In addition, RESF1 is not required for the capacity of NANOG and its downstream target ESRRB to drive self-renewal in the absence of LIF. However, Resf1 deletion reduces efficiency of PGCLC differentiation in vitro. These results identify Resf1 as a novel player in the regulation of pluripotent stem cells and germ cell specification.

scholarly journals Loss of Resf1 reduces the efficiency of embryonic stem cell self-renewal and germline entry

2021 ◽  
Vol 4 (12) ◽  
pp. e202101190
Author(s):  
Matúš Vojtek ◽  
Ian Chambers
Keyword(s):  
Stem Cells ◽  
Germ Cell ◽  
Primordial Germ Cell ◽  
Embryonic Stem ◽  
Cell Specification ◽  
Self Renewal ◽  
Downstream Target ◽  
Germ Cell Specification ◽  
Positive Effect

Retroelement silencing factor 1 (RESF1) interacts with the key regulators of mouse embryonic stem cells (ESCs) OCT4 and NANOG, and its absence results in sterility of mice. However, the function of RESF1 in ESCs and germline specification is poorly understood. In this study, we used Resf1 knockout cell lines to determine the requirements of RESF1 for ESC self-renewal and for in vitro specification of ESCs into primordial germ cell-like cells (PGCLCs). We found that deletion of Resf1 in ESCs cultured in serum and LIF reduces self-renewal potential, whereas episomal expression of RESF1 has a modest positive effect on ESC self-renewal. In addition, RESF1 is not required for the capacity of NANOG and its downstream target ESRRB to drive self-renewal in the absence of LIF. However, Resf1 deletion reduces the efficiency of PGCLC differentiation in vitro. These results identify Resf1 as a novel player in the regulation of pluripotent stem cells and germ cell specification.

scholarly journals Oxygen tension modulates the mitochondrial genetic bottleneck and influences the segregation of a heteroplasmic mtDNA variant in vitro

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Mikael G. Pezet ◽  
Aurora Gomez-Duran ◽  
Florian Klimm ◽  
Juvid Aryaman ◽  
Stephen Burr ◽  
...  
Keyword(s):  
Germ Cell ◽  
Oxygen Tension ◽  
Germ Line ◽  
Embryonic Stem ◽  
Mitochondrial Diseases ◽  
Genetic Bottleneck ◽  
Cellular Mechanisms ◽  
Germ Cell Specification ◽  
Vitro Model

AbstractMost humans carry a mixed population of mitochondrial DNA (mtDNA heteroplasmy) affecting ~1–2% of molecules, but rapid percentage shifts occur over one generation leading to severe mitochondrial diseases. A decrease in the amount of mtDNA within the developing female germ line appears to play a role, but other sub-cellular mechanisms have been implicated. Establishing an in vitro model of early mammalian germ cell development from embryonic stem cells, here we show that the reduction of mtDNA content is modulated by oxygen and reaches a nadir immediately before germ cell specification. The observed genetic bottleneck was accompanied by a decrease in mtDNA replicating foci and the segregation of heteroplasmy, which were both abolished at higher oxygen levels. Thus, differences in oxygen tension occurring during early development likely modulate the amount of mtDNA, facilitating mtDNA segregation and contributing to tissue-specific mutation loads.

scholarly journals RALYL increases hepatocellular carcinoma stemness by sustaining the mRNA stability of TGF-β2

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xia Wang ◽  
Jin Wang ◽  
Yu-Man Tsui ◽  
Chaoran Shi ◽  
Ying Wang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mrna Stability ◽  
Rna Binding ◽  
Embryonic Stem ◽  
Molecular Characteristics ◽  
Specific Gene ◽  
Functional Studies ◽  
Poor Differentiation ◽  
Development In Vitro

AbstractGrowing evidences suggest that cancer stem cells exhibit many molecular characteristics and phenotypes similar to their ancestral progenitor cells. In the present study, human embryonic stem cells are induced to differentiate into hepatocytes along hepatic lineages to mimic liver development in vitro. A liver progenitor specific gene, RALY RNA binding protein like (RALYL), is identified. RALYL expression is associated with poor prognosis, poor differentiation, and metastasis in clinical HCC patients. Functional studies reveal that RALYL could promote HCC tumorigenicity, self-renewal, chemoresistance, and metastasis. Moreover, molecular mechanism studies show that RALYL could upregulate TGF-β2 mRNA stability by decreasing N6-methyladenosine (m6A) modification. TGF-β signaling and the subsequent PI3K/AKT and STAT3 pathways, upregulated by RALYL, contribute to the enhancement of HCC stemness. Collectively, RALYL is a liver progenitor specific gene and regulates HCC stemness by sustaining TGF-β2 mRNA stability. These findings may inspire precise therapeutic strategies for HCC.

scholarly journals The dyskerin ribonucleoprotein complex as an OCT4/SOX2 coactivator in embryonic stem cells

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Yick W Fong ◽  
Jaclyn J Ho ◽  
Carla Inouye ◽  
Robert Tjian
Keyword(s):  
Stem Cell ◽  
Es Cells ◽  
Embryonic Stem ◽  
In Vitro Transcription ◽  
Specific Gene ◽  
Transcriptional Level ◽  
Ips Cell ◽  
Ribonucleoprotein Complex ◽  
Transcription System

Acquisition of pluripotency is driven largely at the transcriptional level by activators OCT4, SOX2, and NANOG that must in turn cooperate with diverse coactivators to execute stem cell-specific gene expression programs. Using a biochemically defined in vitro transcription system that mediates OCT4/SOX2 and coactivator-dependent transcription of the Nanog gene, we report the purification and identification of the dyskerin (DKC1) ribonucleoprotein complex as an OCT4/SOX2 coactivator whose activity appears to be modulated by a subset of associated small nucleolar RNAs (snoRNAs). The DKC1 complex occupies enhancers and regulates the expression of key pluripotency genes critical for self-renewal in embryonic stem (ES) cells. Depletion of DKC1 in fibroblasts significantly decreased the efficiency of induced pluripotent stem (iPS) cell generation. This study thus reveals an unanticipated transcriptional role of the DKC1 complex in stem cell maintenance and somatic cell reprogramming.

scholarly journals Maturation of Embryonic Stem Cells Into Endothelial Cells in an In Vitro Model of Vasculogenesis

Blood ◽  
1999 ◽  
Vol 93 (4) ◽  
pp. 1253-1263 ◽  
Author(s):  
Masanori Hirashima ◽  
Hiroshi Kataoka ◽  
Satomi Nishikawa ◽  
Norihisa Matsuyoshi ◽  
Shin-Ichi Nishikawa
Keyword(s):  
Cell Adhesion ◽  
Endothelial Cell ◽  
Growth Factor ◽  
Culture System ◽  
Molecular Mechanisms ◽  
Es Cells ◽  
Embryonic Stem ◽  
Vascular Endothelial ◽  
Cell Cell

A primitive vascular plexus is formed through coordinated regulation of differentiation, proliferation, migration, and cell-cell adhesion of endothelial cell (EC) progenitors. In this study, a culture system was devised to investigate the behavior of purified EC progenitors in vitro. Because Flk-1+ cells derived from ES cells did not initially express other EC markers, they were sorted and used as EC progenitors. Their in vitro differentiation into ECs, via vascular endothelial-cadherin (VE-cadherin)+ platelet-endothelial cell adhesion molecule-1 (PECAM-1)+ CD34−to VE-cadherin+ PECAM-1+CD34+ stage, occurred without exogenous factors, whereas their proliferation, particularly at low cell density, required OP9 feeder cells. On OP9 feeder layer, EC progenitors gave rise to sheet-like clusters of Flk-1+ cells, with VE-cadherin concentrated at the cell-cell junction. The growth was suppressed by Flt-1-IgG1 chimeric protein and dependent on vascular endothelial growth factor (VEGF) but not placenta growth factor (PIGF). Further addition of VEGF resulted in cell dispersion, indicating the role of VEGF in the migration of ECs as well as their proliferation. Cell-cell adhesion of ECs in this culture system was mediated by VE-cadherin. Thus, the culture system described here is useful in dissecting the cellular events of EC progenitors that occur during vasculogenesis and in investigating the molecular mechanisms underlying these processes.

scholarly journals POGZ controls embryonic stem cell self-renewal and pluripotency by association with esBAF and HP1

2021 ◽  
Author(s):  
Xiaoyun Sun ◽  
Linxi Cheng ◽  
Yuhua Sun
Keyword(s):  
Cell Fate ◽  
Neurodevelopmental Disorders ◽  
Embryonic Stem ◽  
Autism Spectrum ◽  
Specific Gene ◽  
Open Chromatin ◽  
Cell Fate Determination ◽  
Chromatin Remodeler ◽  
Self Renewal ◽  
Fate Determination

AbstractPOGZ, which encodes a multi-domain transcription factor, has been found frequently mutated in neurodevelopmental disorders, particularly autism spectrum disorder (ASD) and intellectual disability (ID). However, little is known about its function in ESC self-renewal and pluripotency, cell fate determination as well as in transcriptional regulation. Here, using embryonic stem cells (ESCs) as model, we show that POGZ plays key roles in the maintenance of ESC and cell fate determination by association with the SWI-SNW chromatin remodeler complex and heterochromatin protein 1 (HP1) proteins. POGZ is essential for the maintenance of ESC undifferentiated state, and loss of POGZ leads to ESC differentiation, likely by up-regulation of primitive endoderm and mesoderm lineage genes and by down-regulation of pluripotency-related genes. Mechanistically, POGZ may control ESC-specific gene expression by association with chromatin remodeler complex esBAF and HP1s, and they can form a PBH triplex. POGZ functions primarily to maintain an open chromatin, as loss of POGZ leads to a reduced chromatin accessibility. Regulation of chromatin under control of POGZ depends on esBAF complex. POGZ is extensively co-localized with OCT4/NANOG genome wide. Taken together, we propose that POGZ is a pluripotency-associated factor, and its absence in ESCs causes failure to maintain a proper ESC-specific chromatin state and transcriptional circuitry of pluripotency, which eventually leads to ESC self-renewal and pluripotency defects. Our work provides important insights into the role of POGZ in ESC self-renewal and pluripotency as well as regulation of transcription, which will be useful for understanding the etiology of neurodevelopmental disorders by POGZ mutation.

207 ESTABILSHMENT OF CYNOMOLGUS MONKEY EMBRYONIC STEM CELL LINES AND CONFIRMATION OF THE POSSIBILITY FOR GERMINAL COMPETENCY

2006 ◽  
Vol 18 (2) ◽  
pp. 211
Author(s):  
T. Teramura ◽  
N. Kawata ◽  
N. Fujinami ◽  
M. Takenoshita ◽  
N. Sagawa ◽  
...  
Keyword(s):  
Germ Cell ◽  
Cell Lines ◽  
Cynomolgus Monkey ◽  
Primordial Germ Cell ◽  
Cell Formation ◽  
Embryonic Stem ◽  
Alp Activity ◽  
Weak Expression ◽  
Germ Cell Formation

Embryonic stem cells (ESCs) of nonhuman primate are important tools for human gametogenesis research. Generally, ESCs, embryos, and fetuses of nonhuman primates are similar to these of human. Recently, germ cell formation of mouse ESCs in vitro has been reported. In this study, we established new cynomolgus monkey ES (cyES) lines and determined germinal competency by assessing expression of mRNA markers. CyES lines were established using blastocysts produced by intracytoplasmic sperm injection (ICSI). For inducing super-ovulation, females were treated with 25 IU/kg pregnant mare serum gonadotropin (PMSG) once a day for 9 days, followed by 400 IU/kg hCG. Oocytes were collected 40 h after injection of hCG. After sperm injection, embryos were cultured in mCMRL medium to the blastocyst stage. For ES line establishment, inner cell masses (ICMs) were isolated by immunosurgery. ESC colonies emerged at about 10 days after ICM plating; three cyES cell lines were successfully obtained (3/11; 27.3%). We characterized these lines by immunocytochemistry for Oct-3/4, SSEA-3, and SSEA-4, which are diagnostic markers for primate ESCs, and by assay for alkaline phosphatase (ALP) activity. All cell lines expressed Oct-3/4, SSEA-4 and ALP activity. The previously reported SSEA-3 weak expression in cyES cells was not observed. These lines differentiated spontaneously when they were replaced in non-adherent culture (embryoid body: EB) or injected into SCID mice subcutaneously. To assess germ cell competency in vitro, we analyzed for the presence of vasa mRNA which shows a restricted expression pattern to germ cell formation, and DMC1 and SYCP1 which show specific existence on synaptonema complex in meiosis. Detection of these germ cell markers was performed by RT-PCR with total cDNA from ESCs and EBs. Nanog mRNA was detected only in ESCs. Oct-4 was detected in gonadal tissue of both sexes, ESCs, and EBs. Vasa was expressed in testis, but not in ESCs or somatic cells. Interestingly, we recognized weak expression of Vasa in Day 12-16 EBs. DMC1 and SYCP1 as meiosis markers were not detected. Because Oct-4 and Vasa mRNA are transcribed simultaneously, similar to that in the early part of gametogenesis such as the latter period of primordial germ cell (PGC) migration, PGC formation in cynomolgus EBs could occurr as in some cases of mouse or human EBs previously reported. Although detailed properties such as the functions of these Vasa-positive cells have not been confirmed, these results demonstrate that cyES cells obtained in the current study might contribute to putative germ cells in vitro by differentiating to EBs. This study was supported by a Grant-in-Aid for the 21st Century COE Program of the Japan Mext and by a grant for the Wakayama Prefecture Collaboration of Regional Entities for the Advancement of Technology Excellence of the JST.

154 MOLECULAR CHARACTERIZATION OF CAT PRIMORDIAL GERM CELLS

2016 ◽  
Vol 28 (2) ◽  
pp. 207
Author(s):  
J. Galiguis ◽  
C. E. Pope ◽  
C. Dumas ◽  
G. Wang ◽  
R. A. MacLean ◽  
...  
Keyword(s):  
Stem Cells ◽  
Germ Cell ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Primordial Germ Cell ◽  
Embryonic Stem ◽  
Transcript Abundance ◽  
Domestic Cat ◽  
Sample Type

As precursors to germline stem cells and gametes, there are many potential applications for primordial germ cells (PGC). Primordial germ cell-like cells have been generated from mouse embryonic stem cells and induced pluripotent stem cells, which subsequently were used to produce functional spermatozoa, oocytes, and healthy offspring (Hayashi et al. 2012 Science 338(6109), 971–975). Applying this approach to generate sperm and oocytes of endangered species is an appealing prospect. Detection of molecular markers associated with PGC is essential to optimizing the process of PGC induction. In the current study, in vitro-derived domestic cat embryos were assessed at various developmental stages to characterise the expression of markers related to the specification process of cat PGC. In vivo-matured, IVF oocytes were cultured until Days 7, 9, and 12 post-insemination. Then, embryos were assessed by RT-qPCR to determine relative transcript abundance of the pluripotency markers NANOG, POU5F1, and SOX2; the epiblast marker DNMT3B; the primitive endoderm marker GATA4; the PGC marker PRDM14; and the germ cell marker VASA; RPS19 was used as the internal reference gene. To validate the qPCR results, fibroblasts served as the negative control cells, whereas spermatogonial stem cells (SSC) served as the positive control cells for GATA4, PRDM14, and VASA. Total mRNA were isolated using the Cells-to-cDNA™ II Kit (Ambion/Thermo Fisher Scientific, Waltham, MA, USA) from either pools of 2 to 6 embryos or ~25 000 fibroblasts/SSC. A minimum of 2 biological replicates for each sample type was analysed, with transcript abundance detected in 2 technical replicates by SYBR Green chemistry. Student’s t-tests were performed on the ΔCts for statistical analysis. PRDM14, specific to the germ cell lineage, was detected as early as Day 7, suggesting the presence of PGC precursor cells. Compared with their levels at Day 7, PRDM14 expression was 0.34-fold lower in SSC (P < 0.05), whereas expression of VASA and GATA4 were 1964-fold and 144-fold higher, respectively (P < 0.05). This seems to emphasise the relative importance of PRDM14 in pre-germ cell stages. In general, all genes analysed were up-regulated from Day 7 to Day 9. This up-regulation was statistically significant for SOX2 and GATA4 (P < 0.05). Relative to that at Day 9, all transcripts were relatively less abundant at Day 12 (P < 0.05 for NANOG, POU5F1, SOX2, DNMT3B, and PRDM14). The data suggest that PGC specification takes place near Day 9, with peak specification activity concluding by Day 12. Although much needs be explored about PGC specification in the cat before applying induction and in vitro germ cell production techniques, these findings represent the first step towards a new potential strategy for preserving endangered and threatened felids.

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