scholarly journals Citrinin induces apoptosis via a mitochondria-dependent pathway and inhibition of survival signals in embryonic stem cells, and causes developmental injury in blastocysts

2007 ◽  
Vol 404 (2) ◽  
pp. 317-326 ◽  
Author(s):  
Wen-Hsiung Chan

The mycotoxin CTN (citrinin), a natural contaminant in foodstuffs and animal feeds, has cytotoxic and genotoxic effects on various mammalian cells. CTN is known to cause cell injury, including apoptosis, but the precise regulatory mechanisms of CTN action, particularly in stem cells and embryos, are currently unclear. In the present paper, I report that CTN has cytotoxic effects on mouse embryonic stem cells and blastocysts, and is associated with defects in their subsequent development, both in vitro and in vivo. Experiments in embryonic stem cells (ESC-B5) showed that CTN induces apoptosis via ROS (reactive oxygen species) generation, increased Bax/Bcl-2 ratio, loss of MMP (mitochondrial membrane potential), induction of cytochrome c release, and activation of caspase 3. In this model, CTN triggers cell death via inactivation of the HSP90 [a 90 kDa isoform of the HSP (heat-shock protein) family proteins]/multichaperone complex and subsequent degradation of Ras and Raf-1, further inhibiting anti-apoptotic processes, such as the Ras→ERK (extracellular-signal-regulated kinase) signal transduction pathway. In addition, CTN causes early developmental injury in mouse ESCs and blastocysts in vitro. Lastly, using an in vivo mouse model, I show that consumption of drinking water containing 10 μM CTN results in blastocyst apoptosis and early embryonic developmental injury. Collectively, these findings show for the first time that CTN induces ROS and mitochondria-dependent apoptotic processes, inhibits Ras→ERK survival signalling via inactivation of the HSP90/multichaperone complex, and causes developmental injury in vivo.

2015 ◽  
Vol 13 (1) ◽  
pp. 720-730 ◽  
Author(s):  
LIPING OU ◽  
LIAOQIONG FANG ◽  
HEJING TANG ◽  
HAI QIAO ◽  
XIAOMEI ZHANG ◽  
...  

2010 ◽  
Vol 88 (3) ◽  
pp. 479-490 ◽  
Author(s):  
Guoliang Meng ◽  
Shiying Liu ◽  
Xiangyun Li ◽  
Roman Krawetz ◽  
Derrick E. Rancourt

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.


2007 ◽  
Vol 19 (1) ◽  
pp. 231
Author(s):  
S. Wang ◽  
X. Tang ◽  
Y. Niu ◽  
H. Chen ◽  
T. Li ◽  
...  

The rabbit, as a laboratory animal model, has several advantages in the study of human physiological disorders. In this study, stable putative pluripotent rabbit embryonic stem cells (rESCs) were derived from in vivo-fertilized and in vitro-cultured blastocysts. The rabbit ICMs were obtained by 0.05% trypsin–0.008% EDTA treatment and mechanical separation; the ES-like cell colonies seen several days later. ICM-derived outgrowths which were treated with 5 mg/mL-1 dispase, followed by 0.05% trypsin–0.008% EDTA, were mechanically disaggregated into small clumps and reseeded on MEFs. The putative ES cell lines maintained expression of pluripotent cells markers and normal XY karyotype for long periods of culture (>1 month). The putative rESCs expressed alkaline phosphatase, transcription factor Oct-4, stage-specific embryonic antigens (SSEA-1, SSEA-3, and SSEA-4), and tumor-related antigens (TRA-1-60 and TRA-1-81). The morphological characteristics of the putative ESCs are closer to those of human ESCs; their high speed of proliferation, however, is closer to that of mouse ESCs. Putative rabbit ESCs were induced to differentiate into many cell types including trophoblast cells, similar to primate ESCs, in vitro, and formed teratomas with derivatives of the 3 major germ layers in vivo when injected into SCID mice. Using RT-PCR measurement, but with some differences in ligands and inhibitors, and comparing with human and mouse ESCs, the putative rabbit ESCs expressed similar genes related to pluripotency (Oct-4, Nanog, SOX2, and UTF-1) and similar genes of FGF, WNT, and TGF signaling pathways related to the proliferation and self-renewal. Our further research work showed that TGF beta and FGF pathways cooperate to maintain pluripotency of rabbit ESCs similar to those of human ES cells.


2004 ◽  
Vol 10 (9-10) ◽  
pp. 1518-1525 ◽  
Author(s):  
Robert C. Bielby ◽  
Aldo R. Boccaccini ◽  
Julia M. Polak ◽  
Lee D.K. Buttery

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1527-1527
Author(s):  
Frank Timmermans ◽  
Imke Velghe ◽  
Lieve Van Walleghem ◽  
Magda De Smedt ◽  
Stefanie Van Coppernolle ◽  
...  

Abstract Background: Human embryonic stem cells (hESC) are derived from early stage blastocysts and are characterized by the ability to both self-renew and to generate differentiated functional cell types. One of the major challenges in the field of hESC research, is to set up a culture system that drives hESC down a particular lineage fate. To date, studies reporting hematopoietic development have not provided evidence on the differentiation capacity of hESC into T lineage cells in vitro. Material and Methods: hESC line H1 (National Institutes of Health [NIH] code: WA01), Wisconson, Madison, USA) was used (Passage 30–60) in all experiments. The hESC line was kept in an undifferentiated state on MEFs as previously described. OP9 cells and OP9 cells that express high levels of the Notch ligand Delta-like 1 (OP9-DLL1, a gift from J. C. Zuniga-Pflücker, University of Toronto, Canada) were cultured as previously described in MEM-α with 20 % FCS. Results: Our data show that T cells can be generated in vitro from hESC in a robust and highly reproducible manner using the sequential exposure of hESC to the murine OP9 cell line and OP9-DLL1. On OP9 stromal layers, a CD34highCD43dim hematopoietic precursor population is generated that is confined to vascular-like structures, reminiscent of blood islands that emerge during in vivo embryonic development. This precursor population becomes T lineage committed when exposed to OP9-DLL1 monolayers, passing sequentially through a CD34+CD7+ phenotype, a CD4+CD8+ double positive intermediate stage and eventually differentiates into a mature T cells. Polyclonal T cells are generated, cell receptor (TCR) alpha-beta and TCRgamma-delta which are functional based on proliferative capacity and production of cytokines after TCR crosslinking. Conclusion: We show that mature and functional T cells can be generated from hESC using well defined in vitro conditions. This protocol in combination with the recently described induced pluripotent cells may find clinical applicability in tumor immunology.


2012 ◽  
Vol 48 (3) ◽  
pp. 165-174 ◽  
Author(s):  
Marlen Keil ◽  
Antje Siegert ◽  
Klaus Eckert ◽  
Jörg Gerlach ◽  
Wolfram Haider ◽  
...  

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