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Sample records for murine embryonal endothelial

  1. An in vitro embryotoxicity assay based on the disturbance of the differentiation of murine embryonic stem cells into endothelial cells. II. Testing of compounds.

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    Festag, Matthias; Viertel, Bruno; Steinberg, Pablo; Sehner, Claudia

    2007-12-01

    The embryonic stem cell test (EST) developed by Spielmann et al. [Spielmann, H., Pohl, I., Doering, B., Liebsch, M., Moldenhauer, F., 1997. The embryonic stem cell test, an in vitro embryotoxicity test using two permanent mouse cell lines: 3T3 fibroblasts and embryonic stem cells. In Vitro. Toxicol. 10, 119-127] is currently the most promising in vitro assay to predict the embryotoxic potential of compounds. In this assay the disturbance of the differentiation of embryonic stem (ES) cells into contracting cardiomyocytes by test compounds as well as the direct cytotoxicity of the test compounds on ES cells and 3T3 fibroblasts is analyzed. On the basis of these results and by applying a biostatistical prediction model (PM) [Genschow, E., Scholz, G., Brown, N., Piersma, A., Brady, M., Clemann, N., Huuskonen, H., Paillard, F., Bremer, S., Becker, K., Spielmann, H., 2000. Development of prediction models for three in vitro embryotoxicity tests in an ECVAM validation study. In Vitr. Mol. Toxicol. 13, 51-66; Genschow, E., Spielmann, H., Scholz, G., Pohl, I., Seiler, A., Clemann, N., Bremer, S., Becker, K., 2004. Validation of the embryonic stem cell test in the international ECVAM validation study on three in vitro embryotoxicity tests. Altern. Lab. Anim. 32, 209-244; Genschow, E., Spielmann, H., Scholz, G., Seiler, A., Brown, N., Piersma, A., Brady, M., Clemann, N., Huuskonen, H., Paillard, F., Bremer, S., Becker, K., 2002. The ECVAM international validation study on in vitro embryotoxicity tests: results of the definitive phase and evaluation of prediction models. European Centre for the Validation of Alternative Methods. Altern. Lab. Anim. 30, 151-176] test compounds can be classified as non-embryotoxic, weakly or strongly embryotoxic. In order to introduce a further endpoint into the EST, the disturbance of vasculogenesis and/or angiogenesis, a protocol to differentiate ES cells into endothelial cells, was established in the accompanying paper. PECAM-1 and VE

  2. Endothelial cells derived from human embryonic stem cells

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    Levenberg, Shulamit; Golub, Justin S.; Amit, Michal; Itskovitz-Eldor, Joseph; Langer, Robert

    2002-04-01

    Human embryonic stem cells have the potential to differentiate into various cell types and, thus, may be useful as a source of cells for transplantation or tissue engineering. We describe here the differentiation steps of human embryonic stem cells into endothelial cells forming vascular-like structures. The human embryonic-derived endothelial cells were isolated by using platelet endothelial cell-adhesion molecule-1 (PECAM1) antibodies, their behavior was characterized in vitro and in vivo, and their potential in tissue engineering was examined. We show that the isolated embryonic PECAM1+ cells, grown in culture, display characteristics similar to vessel endothelium. The cells express endothelial cell markers in a pattern similar to human umbilical vein endothelial cells, their junctions are correctly organized, and they have high metabolism of acetylated low-density lipoprotein. In addition, the cells are able to differentiate and form tube-like structures when cultured on matrigel. In vivo, when transplanted into SCID mice, the cells appeared to form microvessels containing mouse blood cells. With further studies, these cells could provide a source of human endothelial cells that could be beneficial for potential applications such as engineering new blood vessels, endothelial cell transplantation into the heart for myocardial regeneration, and induction of angiogenesis for treatment of regional ischemia.

  3. Use of murine embryonic stem cells in embryotoxicity assays: the embryonic stem cell test.

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    Seiler, Andrea E M; Buesen, Roland; Visan, Anke; Spielmann, Horst

    2006-01-01

    The embryonic stem cell test (EST) takes advantage of the potential of murine embryonic stem (ES) cells to differentiate in culture to test embryotoxicity in vitro. The EST represents a scientifically validated in vitro system for the classification of compounds according to their teratogenic potential based on the morphological analysis of beating cardiomyocytes in embryoid body outgrowths compared to cytotoxic effects on murine ES cells and differentiated 3T3 fibroblasts. Through a number of prevalidation and validation studies, the EST has been demonstrated to be a reliable alternative method for embryotoxicity testing based on the most important mechanisms in embryotoxicity-cytotoxicity and differentiation--as well as on differences in sensitivity between differentiated and embryonic tissues. Improvements of the EST protocol using flow cytometry analysis showed that differential expression of sarcomeric myosin heavy chain and alpha-actinin proteins quantified under the influence of a test compound is a useful marker for detecting potential teratogenicity. The in vitro embryotoxicity test described in this chapter is rapid, simple, and sensitive and can be usefully employed as a component of the risk/hazard assessment process.

  4. Endothelial pentraxin 3 contributes to murine ischemic acute kidney injury

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    Chen, Jianlin; Matzuk, Martin M.; Zhou, Xin J.; Lu, Christopher Y.

    2012-01-01

    Toll-like receptor 4 (TLR4), a receptor forDamage Associated Molecular Pattern Molecules and also the lipopolysaccharide receptor, is required for early endothelial activation leading to maximal inflammation and injury during murine ischemic acute kidney injury. DNA microarray analysis of ischemic kidneys from TLR4-sufficient and deficient mice showed that pentraxin 3 (PTX3) was upregulated only on the former while transgenic knockout of PTX3 ameliorated acute kidney injury. PTX3 was expressed predominantly on peritubular endothelia of the outer medulla of the kidney in control mice. Acute kidney injury increased PTX3 protein in the kidney and the plasma where it may be a biomarker of the injury. Stimulation by hydrogen peroxide, or the TLR4 ligands recombinant human High-Mobility Group protein B1 or lipopolysaccharide, induced PTX3 expression in the Mile Sven 1 endothelial cell line and in primary renal endothelial cells suggesting that endothelial PTX3 was induced by pathways involving TLR4 and reactive oxygen species. This increase was inhibited by conditional endothelial knockout of Myeloid differentiation primary response gene 88, a mediator of a TLR4 intracellular signaling pathway. Compared to wild type mice, PTX3 knockout mice had decreased endothelial expression of cell adhesion molecules at 4 hours of reperfusion possibly contributing to a decreased early maladaptive inflammation in the kidneys of knockout mice. At 24 hours of reperfusion, PTX3 knockout increased expression of endothelial adhesion molecules when regulatory and reparative leukocytes enter the kidney. Thus, endothelial PTX3 plays a pivotal role in the pathogenesis of ischemic acute kidney injury. PMID:22895517

  5. Vascular Endothelial Growth Factor from Embryonic Status to Cardiovascular Pathology

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    Mohsen Azimi-Nezhad

    2014-05-01

    Full Text Available Vascular endothelial growth factor (VEGF is a multifunctional cytokine with distinct functions in angiogenesis, lymphangiogenesis, vascular permeability, and hematopoiesis. VEGF is a highly conserved, disulfide-bonded dimeric glycoprotein of 34 to 45 kDa produced by several cell types including fibroblasts, neutrophils, endothelial cells, and peripheral blood mononuclear cells, particularly T lymphocytes and macrophages. Six VEGF isoforms are generated as a result of alternative splicing from a single VEGF gene, consisting of 121, 145, 165, 183, 189, or 206 amino acids. VEGF121, VEGF145, and VEGF165 are secreted whereas VEGF183, VEGF189, and VEGF206 are cell membrane-bound. VEGF145 has a key role during the vascularization of the human ovarian follicle and corpus luteum, in the placentation and embryonic periods, and in bone and wound healing, while VEGF165 is the most abundant and biologically active isoform. VEGF has been linked with a number of vascular pathologies including cardiovascular diseases such ischemic heart disease, heart failure, stroke, and diabetes and its related complications. In this review we aimed to present some important roles of VEGF in a number of clinical issues and indicate its involvement in several phenomena from the initial steps of the embryonic period to cardiovascular diseases.

  6. Angiogenic potential of endothelial progenitor cells and embryonic stem cells

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    Rae Peter C

    2011-05-01

    Full Text Available Abstract Background Endothelial progenitor cells (EPCs are implicated in a range of pathological conditions, suggesting a natural therapeutic role for EPCs in angiogenesis. However, current angiogenic therapies involving EPC transplantation are inefficient due to rejection of donor EPCs. One solution is to derive an expanded population of EPCs from stem cells in vitro, to be re-introduced as a therapeutic transplant. To demonstrate the therapeutic potential of EPCs we performed in vitro transplantation of EPCs into endothelial cell (EC tubules using a gel-based tubule formation assay. We also described the production of highly angiogenic EPC-comparable cells from pluripotent embryonic stem cells (ESCs by direct differentiation using EC-conditioned medium (ECCM. Results The effect on tubule complexity and longevity varied with transplantation quantity: significant effects were observed when tubules were transplanted with a quantity of EPCs equivalent to 50% of the number of ECs originally seeded on to the assay gel but not with 10% EPC transplantation. Gene expression of the endothelial markers VEGFR2, VE-cadherin and CD31, determined by qPCR, also changed dynamically during transplantation. ECCM-treated ESC-derived progenitor cells exhibited angiogenic potential, demonstrated by in vitro tubule formation, and endothelial-specific gene expression equivalent to natural EPCs. Conclusions We concluded the effect of EPCs is cumulative and beneficial, relying on upregulation of the angiogenic activity of transplanted cells combined with an increase in proliferative cell number to produce significant effects upon transplantation. Furthermore, EPCs derived from ESCs may be developed for use as a rapidly-expandable alternative for angiogenic transplantation therapy.

  7. Role of nitric oxide signaling in endothelial differentiation of embryonic stem cells.

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    Huang, Ngan F; Fleissner, Felix; Sun, John; Cooke, John P

    2010-10-01

    Signaling pathways that govern embryonic stem cell (ESCs) differentiation are not well characterized. Nitric oxide (NO) is a potent vasodilator that modulates other signaling pathways in part by activating soluble guanylyl cyclase (sGC) to produce cyclic guanosine monophosphate (cGMP). Because of its importance in endothelial cell (EC) growth in the adult, we hypothesized that NO may play a critical role in EC development. Accordingly, we assessed the role of NO in ESC differentiation into ECs. Murine ESCs differentiated in the presence of NO synthase (NOS) inhibitor NG-nitroarginine methyl ester (L-NAME) for up to 11 days were not significantly different from vehicle-treated cells in EC markers. However, by 14 days, L-NAME-treated cells manifested modest reduction in EC markers CD144, FLK1, and endothelial NOS. ESC-derived ECs generated in the presence of L-NAME exhibited reduced tube-like formation in Matrigel. To understand the discrepancy between early and late effects of L-NAME, we assessed the NOS machinery and observed low mRNA expression of NOS and sGC subunits in ESCs, compared to differentiating cells after 14 days. In response to NO donors or activation of NOS or sGC, cellular cGMP levels were undetectable in undifferentiated ESCs, at low levels on day 7, and robustly increased in day 14 cells. Production of cGMP upon NOS activation at day 14 was inhibited by L-NAME, confirming endogenous NO dependence. Our data suggest that NOS elements are present in ESCs but inactive until later stages of differentiation, during which period NOS inhibition reduces expression of EC markers and impairs angiogenic function.

  8. Characterization and comparison of embryonic stem cell-derived KDR+ cells with endothelial cells.

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    Sun, Xuan; Cheng, Lamei; Duan, Huaxin; Lin, Ge; Lu, Guangxiu

    2012-09-01

    Growing interest in utilizing endothelial cells (ECs) for therapeutic purposes has led to the exploration of human embryonic stem cells (hESCs) as a potential source for endothelial progenitors. In this study, ECs were induced from hESC lines and their biological characteristics were analyzed and compared with both cord blood endothelial progenitor cells (CBEPCs) and human umbilical vein endothelial cells (HUVECs) in vitro. The results showed that isolated embryonic KDR+ cells (EC-KDR+) display characteristics that were similar to CBEPCs and HUVECs. EC-KDR+, CBEPCs and HUVECs all expressed CD31 and CD144, incorporated DiI-Ac-LDL, bound UEA1 lectin, and were able to form tube-like structures on Matrigel. Compared with CBEPCs and HUVECs, the expression level of endothelial progenitor cell markers such as CD133 and KDR in EC-KDR+ was significantly higher, while the mature endothelial marker vWF was lowly expressed in EC-KDR+. In summary, the study showed that EC-KDR+ are primitive endothelial-like progenitors and might be a potential source for therapeutic vascular regeneration and tissue engineering.

  9. Parameters influencing derivation of embryonic stem cells from murine embryos.

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    Batlle-Morera, Laura; Smith, Austin; Nichols, Jennifer

    2008-12-01

    The derivation of ES cells is poorly understood and varies in efficiency between different strains of mice. We have investigated potential differences between embryos of permissive and recalcitrant strains during diapause and ES cell derivation. We found that in diapause embryos of the recalcitrant C57BL/6 and CBA strains, the epiblast failed to expand during the primary explant phase of ES cell derivation, whereas in the permissive 129 strain, it expanded dramatically. Epiblasts from the recalcitrant strains could be expanded by reducing Erk activation. Isolation of 129 epiblasts facilitated very efficient derivation of ES cell lines in serum- and feeder-free conditions, but reduction of Erk activity was required for derivation of ES cells from isolated C57BL/6 or CBA epiblasts. The results suggest that the discrepancy in ES cell derivation efficiency is not attributable merely to variable prodifferentiative effects of the extra-embryonic lineages but also to an intrinsic variability within the epiblast to maintain pluripotency.

  10. Functional endothelial cells derived from embryonic stem cells labeled with HIV transactivator peptide-conjugated superparamagnetic nanoparticles

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    GAO Bin; FU Wei-guo; DONG Zhi-hui; FANG Zheng-dong; LIU Zhen-jie; SI Yi; ZHANG Xiang-man; WANG Yu-qi

    2011-01-01

    Background The development of regenerative therapies using derivatives of embryonic stem (ES) cells would be facilitated by a non-invasive method to monitor transplanted cells in vivo,for example,magnetic resonance imaging of cells labeled with superparamagnetic iron oxide (SPIO) nanoparticles.Although ES cells have been labeled with SPIO particles,the potential adverse effects of the label have not been fully examined.The objective of this study was to determine whether SPIO labeling affects murine ES cell viability,proliferation,or ability to differentiate into functional endothelial cells (ECs).Methods Cross-linked iron oxide (CLIO,an SPIO) was conjugated with human immunodeficiency virus transactivator of transcription (HIV-Tat) peptides,and murine ES cells were labeled with either CLiO-Tat,CLIO,or HIV-Tat.After labeling,ES cells were cultured for 4 days and FIk-1+ ES cells identified and sorted by immunocytochemistry and fluorescence activated cell sorting (FACS).FIk-1+ cells were raplated on fibronectin-coated dishes,and ECs were obtained by culturing these for 4 weeks in endothelial cell growth medium supplemented with vascular endothelial growth factor (VEGF).ES cell viability was determined using trypan blue exclusion,and the proportion of SPIO+ cells was evaluated using Prussian blue staining and transmission electron microscopy.After differentiation,the behavior and phenotype of ECs were analyzed by reverse transcription-polymerase chain reaction,flow cytometry,immunocytochemistry,Dil-labeled acetylated low-density lipoprotein (AcLDL) uptake,and Matrigel tube formation assay.Results CLIO-Tat was a highly effective label for ES cells,with >96% of cells incorporating the particles,and it did not alter the viability of the labeled cells.ECs derived from CLIO-Tat+ ES cells were very similar to murine aortic ECs in their morphology,expression of endothelial cell markers,ability to form vascular-like channels,and scavenging of AcLDL from the culture medium

  11. The Hemogenic Competence of Endothelial Progenitors Is Restricted by Runx1 Silencing during Embryonic Development

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    Alexia Eliades

    2016-06-01

    Full Text Available It is now well-established that hematopoietic stem cells (HSCs and progenitor cells originate from a specialized subset of endothelium, termed hemogenic endothelium (HE, via an endothelial-to-hematopoietic transition. However, the molecular mechanisms determining which endothelial progenitors possess this hemogenic potential are currently unknown. Here, we investigated the changes in hemogenic potential in endothelial progenitors at the early stages of embryonic development. Using an ETV2::GFP reporter mouse to isolate emerging endothelial progenitors, we observed a dramatic decrease in hemogenic potential between embryonic day (E7.5 and E8.5. At the molecular level, Runx1 is expressed at much lower levels in E8.5 intra-embryonic progenitors, while Bmi1 expression is increased. Remarkably, the ectopic expression of Runx1 in these progenitors fully restores their hemogenic potential, as does the suppression of BMI1 function. Altogether, our data demonstrate that hemogenic competency in recently specified endothelial progenitors is restrained through the active silencing of Runx1 expression.

  12. Intracellular uptake of macromolecules by brain lymphatic endothelial cells during zebrafish embryonic development.

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    van Lessen, Max; Shibata-Germanos, Shannon; van Impel, Andreas; Hawkins, Thomas A; Rihel, Jason; Schulte-Merker, Stefan

    2017-05-12

    The lymphatic system controls fluid homeostasis and the clearance of macromolecules from interstitial compartments. In mammals brain lymphatics were only recently discovered, with significant implications for physiology and disease. We examined zebrafish for the presence of brain lymphatics and found loosely connected endothelial cells with lymphatic molecular signature covering parts of the brain without forming endothelial tubular structures. These brain lymphatic endothelial cells (BLECs) derive from venous endothelium, are distinct from macrophages, and are sensitive to loss of Vegfc. BLECs endocytose macromolecules in a selective manner, which can be blocked by injection of mannose receptor ligands. This first report on brain lymphatic endothelial cells in a vertebrate embryo identifies cells with unique features, including the uptake of macromolecules at a single cell level. Future studies will address whether this represents an uptake mechanism that is conserved in mammals and how these cells affect functions of the embryonic and adult brain.

  13. Hepatic differentiation of embryonic stem cells by murine fetal liver mesenchymal cells.

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    Ishii, Takamichi; Yasuchika, Kentaro; Ikai, Iwao

    2013-01-01

    Hepatocytes derived from embryonic stem cells (ESCs) are a potential cell source for regenerative medicine. However, it has been technically difficult to differentiate ESCs into mature hepatocytes because the definitive growth factors and molecular mechanisms governing hepatocyte differentiation have not yet been well defined. The CD45(-)CD49f(+/-)Thy1(+)gp38(+) mesenchymal cells that reside in murine fetal livers induce hepatic progenitor cells to differentiate into mature hepatocytes by direct cell-cell contact. Utilizing these cells, we employ a two-step procedure for hepatic maturation of ESCs: first, ESCs are differentiated into endodermal cells or hepatic progenitor cells, and second, ESC-derived endodermal cells are matured into functional hepatocytes by coculture with murine fetal liver mesenchymal cells. The ESC-derived hepatocyte-like cells possess hepatic functions, including ammonia removal activity, albumin secretion ability, glycogen synthesis and storage, and cytochrome P450 enzymatic activity.

  14. Fine mapping and functional activity of the adenosine deaminase origin in murine embryonic fibroblasts.

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    Sibani, Sahar; Rampakakis, Emmanouil; Di Paola, Domenic; Zannis-Hadjopoulos, Maria

    2008-06-01

    DNA replication initiates at origins within the genome. The late-firing murine adenosine deaminase (mAdA) origin is located within a 2 kb fragment of DNA, making it difficult to examine by realtime technology. In this study, fine mapping of the mAdA region by measuring the abundance of nascent strand DNA identified two origins, mAdA-1 and mAdA-C, located 397 bp apart from each other. Both origins conferred autonomous replication to plasmids transfected in murine embryonic fibroblasts (MEFs), and exhibited similar activities in vivo and in vitro. Furthermore, both were able to recruit the DNA replication initiator proteins Cdc6 and Ku in vitro, similar to other bona fide replication origins. When tested in a murine Ku80(-/-) cell line, both origins exhibited replication activities comparable to those observed in wildtype cells, as did the hypoxanthine-guanine phosphoribosyltransferase (HPRT) and c-myc origins. This contrasts with previously published studies using Ku80-deficient human cells lines and suggests differences in the mechanism of initiation of DNA replication between the murine and human systems.

  15. ERG is required for the differentiation of embryonic stem cells along the endothelial lineage

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    Le Bras Alexandra

    2009-12-01

    Full Text Available Abstract Background The molecular mechanisms that govern stem cell differentiation along the endothelial lineage remain largely unknown. Ets related gene (ERG has recently been shown to participate in the transcriptional regulation of a number of endothelial specific genes including VE-cadherin (CD144, endoglin, and von Willebrand's Factor (vWF. The specific role of the ETS factor ERG during endothelial differentiation has not been evaluated. Results ERG expression and function were evaluated during the differentiation of embryonic stem cells into embryoid bodies (EB. The results of our study demonstrate that ERG is first expressed in a subpopulation of vascular endothelial growth factor receptor 2 (VEGF-R2 expressing cells that also express VE-cadherin. During ES cell differentiation, ERG expression remains restricted to cells of the endothelial lineage that eventually coalesce into primitive vascular structures within embryoid bodies. ERG also exhibits an endothelial cell (EC-restricted pattern during embryogenesis. To further define the role of ERG during ES cell differentiation, we used a knockdown strategy to inhibit ERG expression. Delivery of three independent shRNA led to 70-85% reductions in ERG expression during ES cell differentiation compared to no change with control shRNA. ERG knockdown was associated with a marked reduction in the number of ECs, the expression of EC-restricted genes, and the formation of vascular structures. Conclusion The ETS factor ERG appears to be a critical regulator of EC differentiation.

  16. Different concentrations of kaempferol distinctly modulate murine embryonic stem cell function.

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    Correia, Marcelo; Rodrigues, Ana S; Perestrelo, Tânia; Pereira, Sandro L; Ribeiro, Marcelo F; Sousa, Maria I; Ramalho-Santos, João

    2016-01-01

    Kaempferol (3,4',5,7-tetrahydroxyflavone) is a natural flavonoid with several beneficial and protective effects. It has been demonstrated that kaempferol has anticancer properties, particularly due to its effects on proliferation, apoptosis and the cell cycle. However, possible effects on pluripotent embryonic stem cell function have not yet been addressed. Embryonic stem cells have the ability to self-renew and to differentiate into all three germ layers with potential applications in regenerative medicine and in vitro toxicology. We show that exposure of murine embryonic stem cells (mESC) to high concentrations of kaempferol (200 μM) leads to decreased cell numbers, although the resulting smaller cell colonies remain pluripotent. However, lower concentrations of this compound (20 μM) increase the expression of pluripotency markers in mESCs. Mitochondrial membrane potential and mitochondrial mass are not affected, but a dose-dependent increase in apoptosis takes place. Moreover, mESC differentiation is impaired by kaempferol, which was not related to apoptosis induction. Our results show that low concentrations of kaempferol can be beneficial for pluripotency, but inhibit proper differentiation of mESCs. Additionally, high concentrations induce apoptosis and increase mitochondrial reactive oxygen species (ROS).

  17. Reduced synaptic activity in neuronal networks derived from embryonic stem cells of murine Rett syndrome model.

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    Barth, Lydia; Sütterlin, Rosmarie; Nenniger, Markus; Vogt, Kaspar E

    2014-01-01

    Neurodevelopmental diseases such as the Rett syndrome (RTT) have received renewed attention, since the mechanisms involved may underlie a broad range of neuropsychiatric disorders such as schizophrenia and autism. In vertebrates early stages in the functional development of neurons and neuronal networks are difficult to study. Embryonic stem cell-derived neurons provide an easily accessible tool to investigate neuronal differentiation and early network formation. We used in vitro cultures of neurons derived from murine embryonic stem cells missing the methyl-CpG-binding protein 2 (MECP2) gene (MeCP2-/y) and from wild type cells of the corresponding background. Cultures were assessed using whole-cell patch-clamp electrophysiology and immunofluorescence. We studied the functional maturation of developing neurons and the activity of the synaptic connections they formed. Neurons exhibited minor differences in the developmental patterns for their intrinsic parameters, such as resting membrane potential and excitability; with the MeCP2-/y cells showing a slightly accelerated development, with shorter action potential half-widths at early stages. There was no difference in the early phase of synapse development, but as the cultures matured, significant deficits became apparent, particularly for inhibitory synaptic activity. MeCP2-/y embryonic stem cell-derived neuronal cultures show clear developmental deficits that match phenotypes observed in slice preparations and thus provide a compelling tool to further investigate the mechanisms behind RTT pathophysiology.

  18. Discovery and characterization of novel microRNAs during endothelial differentiation of human embryonic stem cells.

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    Yoo, Jung Ki; Kim, Jumi; Choi, Seong-Jun; Noh, Hye Min; Kwon, Young Do; Yoo, Hanna; Yi, Hyo Seon; Chung, Hyung Min; Kim, Jin Kyeoung

    2012-07-20

    MicroRNAs (miRNAs) are small RNAs that participate in the regulation of genes associated with the differentiation and proliferation. In this study, 5 novel miRNAs were identified from human mesenchymal stem cells and characterized using various analyses. To investigate the potential functions associated with the regulation of cell differentiation, the differences in miRNA expression were examined in undifferentiated and differentiated human embryonic stem (ES) cells using reverse transcription (RT)-PCR analysis. Specifically, 3 miRNAs exhibited decreased expression levels in human umbilical vein endothelial cells (HUVECs) and endothelial cells derived from human ES cells. Putative target genes related to differentiation or maturation of endothelial cells were predicted by seed sequences of 2 novel miRNAs and analyzed for their expression via miRNA-mediated regulation using a luciferase assay. In HUVECs, CDH5 gene expression was directly repressed by hsa-miR-6086. Similarly, hsa-miR-6087 significantly downregulated endoglin expression. Therefore, the roles of these 2 miRNAs may be to directly suppress their target genes, popularly known as endothelial cell markers. Taken together, our results demonstrate that several novel miRNAs perform critical roles in human endothelial cell development.

  19. Angiogenesis gene expression in murine endothelial cells during post-pneumonectomy lung growth

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    Konerding Moritz A

    2011-07-01

    Full Text Available Abstract Although blood vessel growth occurs readily in the systemic bronchial circulation, angiogenesis in the pulmonary circulation is rare. Compensatory lung growth after pneumonectomy is an experimental model with presumed alveolar capillary angiogenesis. To investigate the genes participating in murine neoalveolarization, we studied the expression of angiogenesis genes in lung endothelial cells. After left pneumonectomy, the remaining right lung was examined on days 3, 6, 14 and 21days after surgery and compared to both no surgery and sham thoracotomy controls. The lungs were enzymatically digested and CD31+ endothelial cells were isolated using flow cytometry cell sorting. The transcriptional profile of the CD31+ endothelial cells was assessed using quantitative real-time polymerase chain reaction (PCR arrays. Focusing on 84 angiogenesis-associated genes, we identified 22 genes with greater than 4-fold regulation and significantly enhanced transcription (p

  20. Low immunogenicity of endothelial derivatives from rat embryonic stem cell-like cells

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    Juliane Ladhoff; Michael Bader; Sabine Br(o)sel; Elke Effenberger; Dirk Westermann; Hans-Dieter Volk; Martina Seifert

    2009-01-01

    Embryonic stem cells (ESC) are suggested to be immune-privileged, but they carry the risk of uncontrolled expansion and malignancy. Upon differentiation they lose their tumor-forming capacity, but they become immunogenic by the expression of a normal set of MHC molecules. This immunogenicity might trigger rejection after application in regenerative therapies. In this study MHC expression of and immune responses to endothelial derivatives of rat embryonic stem cell-like cells (RESC) under inflammatory conditions were determined in comparison to primary rat aortic endothelial cells (ECs). Cellular as well as humoral allo-recognition was analyzed in vitro. In addition, immune reactions in vivo were assessed by allo-antibody production and determination of interferon-γ (IFNγ)-secreting allo-reactive T cells. RESC derivatives expressed low but significant levels of MHC class I, and no MHC class II. In response to IFNγ MHC class I expression was enhanced, while class II transactivator induction failed completely in these cells; MHC class II expression remained consistently absent. Functionally, the RESC derivatives showed a reduced allo-stimulatory capacity, protection against humoral allo-recognition in vitro and a slightly diminished susceptibility to cytotoxic T cell lysis. Furthermore, in vivo experiments demonstrated that these cells do not trigger host immune reactions, characterized by no allo-antibody production and no induction of allo-reactive memory T cells. Our results show that endothelial derivatives of RESC have a distinctive reduced immunogenic potency even under inflammatory conditions.

  1. Markers of murine embryonic and neural stem cells, neurons and astrocytes: reference points for developmental neurotoxicity testing

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    Developmental neurotoxicity (DNT) is a significant concern for environmental chemicals, as well as for food and drug constituents. The sensitivity of animal-based DNT models is unclear, and they are expensive and time consuming. Murine embryonic stem cells (mESC) recapitulate sev...

  2. Developmental MicroRNA Expression Profiling of Murine Embryonic Orofacial Tissue

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    Mukhopadhyay, Partha; Brock, Guy; Pihur, Vasyl; Webb, Cynthia; Pisano, M. Michele; Greene, Robert M.

    2011-01-01

    BACKGROUND Orofacial development is a multifaceted process involving precise, spatio-temporal expression of a panoply of genes. MicroRNAs (miRNAs), the largest family of noncoding RNAs involved in gene silencing, represent critical regulators of cell and tissue differentiation. MicroRNA gene expression profiling is an effective means of acquiring novel and valuable information regarding the expression and regulation of genes, under the control of miRNA, involved in mammalian orofacial development. METHODS To identify differentially expressed miRNAs during mammalian orofacial ontogenesis, miRNA expression profiles from gestation day (GD) -12, -13 and -14 murine orofacial tissue were compared utilizing miRXplore microarrays from Miltenyi Biotech. Quantitative real-time PCR was utilized for validation of gene expression changes. Cluster analysis of the microarray data was conducted with the clValid R package and the UPGMA clustering method. Functional relationships between selected miRNAs were investigated using Ingenuity Pathway Analysis. RESULTS Expression of over 26% of the 588 murine miRNA genes examined was detected in murine orofacial tissues from GD-12–GD-14. Among these expressed genes, several clusters were seen to be developmentally regulated. Differential expression of miRNAs within such clusters were shown to target genes encoding proteins involved in cell proliferation, cell adhesion, differentiation, apoptosis and epithelial-mesenchymal transformation, all processes critical for normal orofacial development. CONCLUSIONS Using miRNA microarray technology, unique gene expression signatures of hundreds of miRNAs in embryonic orofacial tissue were defined. Gene targeting and functional analysis revealed that the expression of numerous protein-encoding genes, crucial to normal orofacial ontogeny, may be regulated by specific miRNAs. PMID:20589883

  3. Induction of murine embryonic stem cell differentiation by medicinal plant extracts.

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    Reynertson, Kurt A; Charlson, Mary E; Gudas, Lorraine J

    2011-01-01

    Epidemiological evidence indicates that diets high in fruits and vegetables provide a measure of cancer chemoprevention due to phytochemical constituents. Natural products are a rich source of cancer chemotherapy drugs, and primarily target rapidly cycling tumor cells. Increasing evidence indicates that many cancers contain small populations of resistant, stem-like cells that have the capacity to regenerate tumors following chemotherapy and radiation, and have been linked to the initiation of metastases. Our goal is to discover natural product-based clinical or dietary interventions that selectively target cancer stem cells, inducing differentiation. We adapted an alkaline phosphatase (AP) stain to assay plant extracts for the capacity to induce differentiation in embryonic stem (ES) cells. AP is a characteristic marker of undifferentiated ES cells, and this represents a novel approach to screening medicinal plant extracts. Following a survey of approximately 100 fractions obtained from 12 species of ethnomedically utilized plants, we found fractions from 3 species that induced differentiation, decreasing AP and transcript levels of pluripotency markers (Nanog, Oct-4, Rex-1). These fractions affected proliferation of murine ES, and human embryonal, prostate, and breast carcinoma cells in a dose-dependent manner. Several phytochemical constituents were isolated; the antioxidant phytochemicals ellagic acid and gallic acid were shown to affect viability of cultured breast carcinoma cells. Copyright © 2010 Elsevier Inc. All rights reserved.

  4. Induction of murine embryonic stem cell differentiation by medicinal plant extracts

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    Reynertson, Kurt A. [Center for Complementary and Integrative Medicine, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065 (United States); Department of Pharmacology, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065 (United States); Charlson, Mary E. [Center for Complementary and Integrative Medicine, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065 (United States); Department of Medicine, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065 (United States); Gudas, Lorraine J., E-mail: ljgudas@med.cornell.edu [Center for Complementary and Integrative Medicine, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065 (United States); Department of Pharmacology, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065 (United States); Department of Medicine, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065 (United States)

    2011-01-01

    Epidemiological evidence indicates that diets high in fruits and vegetables provide a measure of cancer chemoprevention due to phytochemical constituents. Natural products are a rich source of cancer chemotherapy drugs, and primarily target rapidly cycling tumor cells. Increasing evidence indicates that many cancers contain small populations of resistant, stem-like cells that have the capacity to regenerate tumors following chemotherapy and radiation, and have been linked to the initiation of metastases. Our goal is to discover natural product-based clinical or dietary interventions that selectively target cancer stem cells, inducing differentiation. We adapted an alkaline phosphatase (AP) stain to assay plant extracts for the capacity to induce differentiation in embryonic stem (ES) cells. AP is a characteristic marker of undifferentiated ES cells, and this represents a novel approach to screening medicinal plant extracts. Following a survey of approximately 100 fractions obtained from 12 species of ethnomedically utilized plants, we found fractions from 3 species that induced differentiation, decreasing AP and transcript levels of pluripotency markers (Nanog, Oct-4, Rex-1). These fractions affected proliferation of murine ES, and human embryonal, prostate, and breast carcinoma cells in a dose-dependent manner. Several phytochemical constituents were isolated; the antioxidant phytochemicals ellagic acid and gallic acid were shown to affect viability of cultured breast carcinoma cells.

  5. In vitro direct osteogenesis of murine embryonic stem cells without embryoid body formation.

    Science.gov (United States)

    Hwang, Yu-Shik; Polak, Julia M; Mantalaris, Athanasios

    2008-10-01

    Embryonic stem cells (ESCs) posses the ability to self-renew and differentiate into a multitude of lineages, including the osteogenic lineage in vitro. Currently, most approaches have focused on embryonic body (EB)-mediated osteogenic differentiation, which relies on formation of all three germ layers resulting in limited yields and labour-intensive culture processes. Our study aimed at developing an efficient culture strategy resulting in the upregulated in vitro osteogenic differentiation of murine ESCs (mESCs), which completely avoided EB formation. Specifically, mESCs were cultured in HepG2 conditioned medium for 3 days and then directed into osteogenic differentiation for 21 days without prior EB formation. The mineralised bone nodules generated were characterized by Alizarin red S-staining, phenotypic alkaline phosphatase expression, time-course analysis of ALPase activity, the presence of type I collagen and osteopontin, and osteocalcin, cbfa-1/runx-2, and osterix gene expression. Our method of direct osteogenic differentiation of mESCs represents a novel and efficient approach that results in enhanced yields and could have significant applications in bone tissue engineering.

  6. Essential role of the TFIID subunit TAF4 in murine embryogenesis and embryonic stem cell differentiation.

    Science.gov (United States)

    Langer, Diana; Martianov, Igor; Alpern, Daniel; Rhinn, Muriel; Keime, Céline; Dollé, Pascal; Mengus, Gabrielle; Davidson, Irwin

    2016-03-30

    TAF4 (TATA-binding protein-associated factor 4) and its paralogue TAF4b are components of the TFIID core module. We inactivated the murine Taf4a gene to address Taf4 function during embryogenesis. Here we show that Taf4a(-/-) embryos survive until E9.5 where primary germ layers and many embryonic structures are identified showing Taf4 is dispensable for their specification. In contrast, Taf4 is required for correct patterning of the trunk and anterior structures, ventral morphogenesis and proper heart positioning. Overlapping expression of Taf4a and Taf4b during embryogenesis suggests their redundancy at early stages. In agreement with this, Taf4a(-/-) embryonic stem cells (ESCs) are viable and comprise Taf4b-containing TFIID. Nevertheless, Taf4a(-/-) ESCs do not complete differentiation into glutamatergic neurons and cardiomyocytes in vitro due to impaired preinitiation complex formation at the promoters of critical differentiation genes. We define an essential role of a core TFIID TAF in differentiation events during mammalian embryogenesis.

  7. Enhancement of oligodendrocyte differentiation from murine embryonic stem cells by an activator of gp130 signaling.

    Science.gov (United States)

    Zhang, Peilin; Chebath, Judith; Lonai, Peter; Revel, Michel

    2004-01-01

    Embryonic stem (ES) cells derived from the inner cell mass of blastocyst-stage embryos are a potential large scale source of oligodendrocytes and of their progenitors for transplantation into the central nervous system for the repair of demyelinating lesions. We found previously that interleukin-6 (IL-6) fused to its soluble receptor (IL-6R), a potent activator of the gp130 receptor, induces myelin gene expression in Schwann cells of embryonic dorsal root ganglia. Like leukemia inhibitory factor, IL-6R/IL-6 inhibits the differentiation of murine ES cells into embryoid bodies. In the present study, we show that this recombinant cytokine may be efficiently used to stimulate the differentiation of oligodendrocytes if added to ES cell-derived neural precursors. IL-6R/IL-6 leads to an increase in early chondroitin sulfate proteoglycan positive and late O4 positive progenitors and to a stimulation of maturation into O1 and myelin basic protein expressing oligodendrocytes. Expression of the genes for transcription factor genes Olig-1 and Sox10, which appear early in the oligodendrocyte lineage, was stimulated by IL-6R/IL-6 addition. We conclude that this cytokine can significantly enhance the derivation of oligodendrocytes from ES cells.

  8. Expanded CAG repeats in the murine Huntington's disease gene increases neuronal differentiation of embryonic and neural stem cells.

    Science.gov (United States)

    Lorincz, Matthew T; Zawistowski, Virginia A

    2009-01-01

    Huntington's disease is an uncommon autosomal dominant neurodegenerative disorder caused by expanded polyglutamine repeats. Increased neurogenesis was demonstrated recently in Huntington's disease post-mortem samples. In this manuscript, neuronally differentiated embryonic stem cells with expanded CAG repeats in the murine Huntington's disease homologue and neural progenitors isolated from the subventricular zone of an accurate mouse Huntington's disease were examined for increased neurogenesis. Embryonic stem cells with expanded CAG repeats in the murine Huntington's disease homologue were demonstrated to undergo facilitated differentiation first into neural progenitors, then into more mature neurons. Neural progenitor cells isolated from the subventricular zone of a Huntington's disease knock-in animal displayed increased production of neural progenitors and increased neurogenesis. These findings suggested that neuronally differentiating embryonic stem cells with expanded CAG repeats is a reasonable system to identify factors responsible for increased neurogenesis in Huntington's disease. Expression profiling analysis comparing neuronally differentiating embryonic stem cells with expanded CAG repeats to neuronally differentiating embryonic stem cells without expanded CAG repeats identified transcripts involved in development and transcriptional regulation as factors possibly mediating increased neurogenesis in response to expanded CAG repeats.

  9. Tissue engineering of blood vessels with endothelial cells differentiated from mouse embryonic stem cells

    Institute of Scientific and Technical Information of China (English)

    ZHEN XU; MIN XIONG SHEN; DONG ZHU MA; LI YING WANG; XI LIANG ZHA

    2003-01-01

    Endothelial cells (TEC3 cells) derived from mouse embryonic stem (ES) cells were used as seed cells to construct blood vessels. Tissue engineered blood vessels were made by seeding 8 × l06 smooth muscle cells (SMCs) obtained from rabbit arteries onto a sheet of nonwoven polyglycolic acid (PGA) fibers, which was used as a biodegradable polymer scaffold. After being cultured in DMEM medium for 7 days in vitro, SMCs grew well on the PGA fibers, and the cell-PGA sheet was then wrapped around a silicon tube, and implanted subcutaneously into nude mice. After 6~8 weeks, the silicon tube was replaced with another silicon tube in smaller diameter, and then the TEC3 cells (endothelial cells differentiated from mouse ES cells) were injected inside the engineered vessel tube as the test group. In the control group only culture medium was injected. Five days later, the engineered vessels were harvested for gross observation, histological and immunohistochemical analysis. The preliminary results demonstrated that the SMC-PGA construct could form a tubular structure in 6~8 weeks and PGA fibers were completely degraded. Histological and immunohistochemical analysis of the newly formed tissue revealed a typical blood vessel structure, including a lining of endothelial cells (ECs) on the lumimal surface and the presence of SMC and collagen in the wall. No EC lining was found in the tubes of control group. Therefore, the ECs differentiated from mouse ES cells can serve as seed cells for endothelium lining in tissue engineered blood vessels.

  10. Differentiation and selection of hepatocyte precursors in suspension spheroid culture of transgenic murine embryonic stem cells.

    Directory of Open Access Journals (Sweden)

    Elke Gabriel

    Full Text Available Embryonic stem cell-derived hepatocyte precursor cells represent a promising model for clinical transplantations to diseased livers, as well as for establishment of in vitro systems for drug metabolism and toxicology investigations. This study aimed to establish an in vitro culture system for scalable generation of hepatic progenitor cells. We used stable transgenic clones of murine embryonic stem cells possessing a reporter/selection vector, in which the enhanced green fluorescent protein- and puromycin N-acetyltransferase-coding genes are driven by a common alpha-fetoprotein gene promoter. This allowed for "live" monitoring and puromycin selection of the desired differentiating cell type possessing the activated alpha-fetoprotein gene. A rotary culture system was established, sequentially yielding initially partially selected hepatocyte lineage-committed cells, and finally, a highly purified cell population maintained as a dynamic suspension spheroid culture, which progressively developed the hepatic gene expression phenotype. The latter was confirmed by quantitative RT-PCR analysis, which showed a progressive up-regulation of hepatic genes during spheroid culture, indicating development of a mixed hepatocyte precursor-/fetal hepatocyte-like cell population. Adherent spheroids gave rise to advanced differentiated hepatocyte-like cells expressing hepatic proteins such as albumin, alpha-1-antitrypsin, cytokeratin 18, E-cadherin, and liver-specific organic anion transporter 1, as demonstrated by fluorescent immunostaining. A fraction of adherent cells was capable of glycogen storage and of reversible up-take of indocyanine green, demonstrating their hepatocyte-like functionality. Moreover, after transplantation of spheroids into the mouse liver, the spheroid-derived cells integrated into recipient. These results demonstrate that large-scale hepatocyte precursor-/hepatocyte-like cultures can be established for use in clinical trials, as well as in

  11. Beat Rate Variability in Murine Embryonic Stem Cell-Derived Cardiomyocytes: Effect of Antiarrhythmic Drugs

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    Julius Niehoff

    2016-02-01

    Full Text Available Background/Aims: Heart rate variability (HRV refers to the fluctuation of the time interval between consecutive heartbeats in humans. It has recently been discovered that cardiomyocytes derived from human embryonic and induced pluripotent stem cells show beat rate variability (BRV that is similar to the HRV in humans. In the present study, clinical aspects of HRV were transferred to an in vitro model. The aims of the study were to explore the BRV in murine embryonic stem cell (mESC-derived cardiomyocytes and to demonstrate the influence of antiarrhythmic drugs on BRV as has been shown in clinical trials previously. Methods: The Microelectrode Array (MEA technique was used to perform short-term recordings of extracellular field potentials (FPs of spontaneously beating cardiomyocytes derived from mESCs (D3 cell line, αPig-44. Offline analysis was focused on time domain and nonlinear methods. Results: The Poincaré-Plot analysis of measurements without pharmacological intervention revealed that three different shapes of scatter plots occurred most frequently. Comparable shapes have been described in clinical studies before. The antiarrhythmic drugs Ivabradine, Verapamil and Sotalol augmented BRV, whereas Flecainide decreased BRV parameters at low concentrations (SDSD 79.0 ± 8.7% of control at 10-9 M, p -5 M, p Conclusions: Spontaneously beating cardiomyocytes derived from mESCs showed BRV that appears to be similar to the HRV known from humans. Antiarrhythmic drugs affected BRV parameters similar to clinical observations. Therefore, our study demonstrates that this in vitro model can contribute to a better understanding of electrophysiological properties of mESC-derived cardiomyocytes and might serve as a valuable tool for drug safety screening.

  12. Expanded CAG repeats in the murine Huntington’s disease gene increases neuronal differentiation of embryonic and neural stem cells

    OpenAIRE

    Lorincz, Matthew T.; Zawistowski, Virginia A.

    2008-01-01

    Huntington’s disease is an uncommon autosomal dominant neurodegenerative disorder caused by expanded polyglutamine repeats. Increased neurogenesis was demonstrated recently in Huntington’s disease postmortem samples. In this manuscript, neuronally differentiated embryonic stem cells with expanded CAG repeats in the murine Huntington’s disease homologue and neural progenitors isolated from the subventricular zone of an accurate mouse Huntington’s disease were examined for increased neurogenesi...

  13. Differential Nucleosome Occupancies across Oct4-Sox2 Binding Sites in Murine Embryonic Stem Cells.

    Directory of Open Access Journals (Sweden)

    Amy Sebeson

    Full Text Available The binding sequence for any transcription factor can be found millions of times within a genome, yet only a small fraction of these sequences encode functional transcription factor binding sites. One of the reasons for this dichotomy is that many other factors, such as nucleosomes, compete for binding. To study how the competition between nucleosomes and transcription factors helps determine a functional transcription factor site from a predicted transcription factor site, we compared experimentally-generated in vitro nucleosome occupancy with in vivo nucleosome occupancy and transcription factor binding in murine embryonic stem cells. Using a solution hybridization enrichment technique, we generated a high-resolution nucleosome map from targeted regions of the genome containing predicted sites and functional sites of Oct4/Sox2 regulation. We found that at Pax6 and Nes, which are bivalently poised in stem cells, functional Oct4 and Sox2 sites show high amounts of in vivo nucleosome displacement compared to in vitro. Oct4 and Sox2, which are active, show no significant displacement of in vivo nucleosomes at functional sites, similar to nonfunctional Oct4/Sox2 binding. This study highlights a complex interplay between Oct4 and Sox2 transcription factors and nucleosomes among different target genes, which may result in distinct patterns of stem cell gene regulation.

  14. Differential Nucleosome Occupancies across Oct4-Sox2 Binding Sites in Murine Embryonic Stem Cells.

    Science.gov (United States)

    Sebeson, Amy; Xi, Liqun; Zhang, Quanwei; Sigmund, Audrey; Wang, Ji-Ping; Widom, Jonathan; Wang, Xiaozhong

    2015-01-01

    The binding sequence for any transcription factor can be found millions of times within a genome, yet only a small fraction of these sequences encode functional transcription factor binding sites. One of the reasons for this dichotomy is that many other factors, such as nucleosomes, compete for binding. To study how the competition between nucleosomes and transcription factors helps determine a functional transcription factor site from a predicted transcription factor site, we compared experimentally-generated in vitro nucleosome occupancy with in vivo nucleosome occupancy and transcription factor binding in murine embryonic stem cells. Using a solution hybridization enrichment technique, we generated a high-resolution nucleosome map from targeted regions of the genome containing predicted sites and functional sites of Oct4/Sox2 regulation. We found that at Pax6 and Nes, which are bivalently poised in stem cells, functional Oct4 and Sox2 sites show high amounts of in vivo nucleosome displacement compared to in vitro. Oct4 and Sox2, which are active, show no significant displacement of in vivo nucleosomes at functional sites, similar to nonfunctional Oct4/Sox2 binding. This study highlights a complex interplay between Oct4 and Sox2 transcription factors and nucleosomes among different target genes, which may result in distinct patterns of stem cell gene regulation.

  15. Involvement of PIKE in icariin induced cardiomyocyte differentiation from murine embryonic stem cells.

    Science.gov (United States)

    Zhou, Limin; Zheng, Bei; Tang, Leilei; Huang, Yujie; Zhu, Danyan

    2014-03-01

    Icariin (ICA) has demonstrated to induce cardiomyocyte differentiation from murine embryonic stem (ES) cells in vitro, however, the mechanisms have not been fully elucidated. In the present study, we investigated whether phosphatidylinositol 3-kinase enhancer (PIKE) was involved in ICA induced cardiomyocyte differentiation of ES cells. Small interfering RNA (siRNA) of PIKE was applied to investigate the role of PIKE in ICA induced cardiomyocyte differentiation. The cardiomyocytes derived from ES cells were verified using immunofluorescence. The expressions of Troponin T, PIKE, phosphatidylinositol 3-kinase (PI3K), and nuclear factor-kappaB (NF-kappaB) were detected by western blot. The change of reactive oxygen species (ROS) generation was estimated using the fluorescent dye 2', 7' - dichlorodihydrofluorescein diacetate. The results showed that PIKE expression increased during cardiomyocyte differentiation. ICA markedly enhanced PIKE and PI3K expression in a time-dependent manner. Knockdown of PIKE by siRNAs blocked the differentiation of ES cells into cardiomyocytes expressing alpha-actinin for cardiac sarcomeric structures. Moreover, reduced ROS generation and NF-kappaB nuclear translocation were responsible for the inhibitory effect of si-PIKE. In conclusion, PIKE was involved in ICA induced cardiomyocyte differentiation, and ROS generation and NF-kappaB nuclear translocation were associated with PIKE activation.

  16. An embryonic stage-specific enhancer within the murine β-globin locus mediates domain-wide histone hyperacetylation.

    Science.gov (United States)

    Fromm, George; Cadiz-Rivera, Brenda; de Vries, Christina; Getman, Michael; McGrath, Kathleen E; Kingsley, Paul D; Fields, Jennifer; Fiering, Steven; Bulger, Michael

    2011-05-12

    In mammalian nuclei, a select number of tissue-specific gene loci exhibit broadly distributed patterns of histone modifications, such as histone hyperacetylation, that are normally associated with active gene promoters. Previously, we characterized such hyperacetylated domains within mammalian β-globin gene loci, and determined that within the murine locus, neither the β-globin locus control region nor the gene promoters were required for domain formation. Here, we identify a developmentally specific erythroid enhancer, hypersensitive site-embryonic 1 (HS-E1), located within the embryonic β-globin domain in mouse, which is homologous to a region located downstream of the human embryonic ε-globin gene. This sequence exhibits nuclease hypersensitivity in primitive erythroid cells and acts as an enhancer in gain-of-function assays. Deletion of HS-E1 from the endogenous murine β-globin locus results in significant decrease in the expression of the embryonic β-globin genes and loss of the domain-wide pattern of histone hyperacetylation. The data suggest that HS-E1 is an enhancer that is uniquely required for β-like globin expression in primitive erythroid cells, and that it defines a novel class of enhancer that works in part by domain-wide modulation of chromatin structure.

  17. An embryonic stage–specific enhancer within the murine β-globin locus mediates domain-wide histone hyperacetylation

    Science.gov (United States)

    Fromm, George; Cadiz-Rivera, Brenda; de Vries, Christina; Getman, Michael; McGrath, Kathleen E.; Kingsley, Paul D.; Fields, Jennifer; Fiering, Steven

    2011-01-01

    In mammalian nuclei, a select number of tissue-specific gene loci exhibit broadly distributed patterns of histone modifications, such as histone hyperacetylation, that are normally associated with active gene promoters. Previously, we characterized such hyperacetylated domains within mammalian β-globin gene loci, and determined that within the murine locus, neither the β-globin locus control region nor the gene promoters were required for domain formation. Here, we identify a developmentally specific erythroid enhancer, hypersensitive site-embryonic 1 (HS-E1), located within the embryonic β-globin domain in mouse, which is homologous to a region located downstream of the human embryonic ϵ-globin gene. This sequence exhibits nuclease hypersensitivity in primitive erythroid cells and acts as an enhancer in gain-of-function assays. Deletion of HS-E1 from the endogenous murine β-globin locus results in significant decrease in the expression of the embryonic β-globin genes and loss of the domain-wide pattern of histone hyperacetylation. The data suggest that HS-E1 is an enhancer that is uniquely required for β-like globin expression in primitive erythroid cells, and that it defines a novel class of enhancer that works in part by domain-wide modulation of chromatin structure. PMID:21321362

  18. ISOBUTYRAMIDE ACTIVATES TRANSCRIPTION OF HUMAN FETAL γ- AND MURINE EMBRYONIC εy-GLOBIN GENES

    Institute of Scientific and Technical Information of China (English)

    张俊武; 张雪青; 陈平

    2001-01-01

    Objective. To examine the effect of isobutyramide synthesized in our laboratory on human and murine globingene expression and to test cell toxicity of the drug.Methods. ME L cells were transfected with the recombinant construct μLCRAγψβδβ3 and the stable transfor-mants were cultured in the medium with different concentrations of isobutyramide. The experimental mice and rab-bit were injected with different doses of isobutyramide. The globin mRNAs were analyzed by RNase protection as-say. The hematologdcal toxicity and electrolyte toxicity of the drug were tested.Results. An inducible and dose-dependent expression of the human γγ-, ββ- and mouse Aa-globin gene was ob-served in the transfected MEL cells. The induction of the human γ-globin gene is significant stronger than that ofthe ββ-globin gene. With 2.5 ~ 5 mmol/L isobutyramide, the induction of the human γ-globin gene is even moreeffective than that of mouse aa-globin gene. After a 15-day injection under the doses of 500 ~ 900mg * kg- 1 * d-1,the level of the mouse embryonic εy-globin mRNA could be significantly induced up to 3 ~ 4 fold of that of uninject-ed controls. The changes of hemoglobin(Hb), RBC, hematocrit(HCT), WBC, derived from mice injected withdifferent doses of isobutyramide at the interval of 24 hours for 2 ~4 weeks, were generally within the normalrange. In rabbits injected with isobutyramide in the same regiment for 2 weeks, the concentration of blood K+,Na +, C1- and CO.2 were all within normal range and serum ionic osmotic pressure remained stable as well.Conclusion. Our results suggested that isobutyramide is a weak inducer of cell differentiation, but it canselectively activate transcription of human γy-globin gene at a certain degree, and it can act on early stages of ery-throid progenitor differentiation in adult mice and activate transcription of embryonic εy-globin gene and have nohematological toxicity. Our results have further proved the potential value of

  19. Reconstitution of mammary epithelial morphogenesis by murine embryonic stem cells undergoing hematopoietic stem cell differentiation.

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    Shuxian Jiang

    Full Text Available BACKGROUND: Mammary stem cells are maintained within specific microenvironments and recruited throughout lifetime to reconstitute de novo the mammary gland. Mammary stem cells have been isolated through the identification of specific cell surface markers and in vivo transplantation into cleared mammary fat pads. Accumulating evidence showed that during the reformation of mammary stem cell niches by dispersed epithelial cells in the context of the intact epithelium-free mammary stroma, non-mammary epithelial cells may be sequestered and reprogrammed to perform mammary epithelial cell functions and to adopt mammary epithelial characteristics during reconstruction of mammary epithelium in regenerating mammary tissue in vivo. METHODOLOGY/PRINCIPAL FINDINGS: To examine whether other types of progenitor cells are able to contribute to mammary branching morphogenesis, we examined the potential of murine embryonic stem (mES cells, undergoing hematopoietic differentiation, to support mammary reconstitution in vivo. We observed that cells from day 14 embryoid bodies (EBs under hematopoietic differentiation condition, but not supernatants derived from these cells, when transplanted into denuded mammary fat pads, were able to contribute to both the luminal and myoepithelial lineages in branching ductal structures resembling the ductal-alveolar architecture of the mammary tree. No teratomas were observed when these cells were transplanted in vivo. CONCLUSIONS/SIGNIFICANCE: Our data provide evidence for the dominance of the tissue-specific mammary stem cell niche and its role in directing mES cells, undergoing hematopoietic differentiation, to reprogram into mammary epithelial cells and to promote mammary epithelial morphogenesis. These studies should also provide insights into regeneration of damaged mammary gland and the role of the mammary microenvironment in reprogramming cell fate.

  20. Differentiation of murine embryonic stem and induced pluripotent stem cells to renal lineage in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Morizane, Ryuji [Department of Internal Medicine, Keio University School of Medicine, Tokyo (Japan); Monkawa, Toshiaki, E-mail: monkawa@sc.itc.keio.ac.jp [Department of Internal Medicine, Keio University School of Medicine, Tokyo (Japan); Itoh, Hiroshi [Department of Internal Medicine, Keio University School of Medicine, Tokyo (Japan)

    2009-12-25

    Embryonic stem (ES) cells which have the unlimited proliferative capacity and extensive differentiation potency can be an attractive source for kidney regeneration therapies. Recent breakthroughs in the generation of induced pluripotent stem (iPS) cells have provided with another potential source for the artificially-generated kidney. The purpose of this study is to know how to differentiate mouse ES and iPS cells into renal lineage. We used iPS cells from mouse fibroblasts by transfection of four transcription factors, namely Oct4, Sox2, c-Myc and Klf4. Real-time PCR showed that renal lineage markers were expressed in both ES and iPS cells after the induction of differentiation. It also showed that a tubular specific marker, KSP progressively increased to day 18, although the differentiation of iPS cells was slower than ES cells. The results indicated that renal lineage cells can be differentiated from both murine ES and iPS cells. Several inducing factors were tested whether they influenced on cell differentiation. In ES cells, both of GDNF and BMP7 enhanced the differentiation to metanephric mesenchyme, and Activin enhanced the differentiation of ES cells to tubular cells. Activin also enhanced the differentiation of iPS cells to tubular cells, although the enhancement was lower than in ES cells. ES and iPS cells have a potential to differentiate to renal lineage cells, and they will be an attractive resource of kidney regeneration therapy. This differentiation is enhanced by Activin in both ES and iPS cells.

  1. Impact of stirred suspension bioreactor culture on the differentiation of murine embryonic stem cells into cardiomyocytes

    Science.gov (United States)

    2011-01-01

    Background Embryonic stem cells (ESCs) can proliferate endlessly and are able to differentiate into all cell lineages that make up the adult organism. Under particular in vitro culture conditions, ESCs can be expanded and induced to differentiate into cardiomyocytes in stirred suspension bioreactors (SSBs). However, in using these systems we must be cognizant of the mechanical forces acting upon the cells. The effect of mechanical forces and shear stress on ESC pluripotency and differentiation has yet to be clarified. The purpose of this study was to investigate the impact of the suspension culture environment on ESC pluripotency during cardiomyocyte differentiation. Results Murine D3-MHC-neor ESCs formed embyroid bodies (EBs) and differentiated into cardiomyocytes over 25 days in static culture and suspension bioreactors. G418 (Geneticin) was used in both systems from day 10 to enrich for cardiomyocytes by eliminating non-resistant, undifferentiated cells. Treatment of EBs with 1 mM ascorbic acid and 0.5% dimethyl sulfoxide from day 3 markedly increased the number of beating EBs, which displayed spontaneous and cadenced contractile beating on day 11 in the bioreactor. Our results showed that the bioreactor differentiated cells displayed the characteristics of fully functional cardiomyocytes. Remarkably, however, our results demonstrated that the bioreactor differentiated ESCs retained their ability to express pluripotency markers, to form ESC-like colonies, and to generate teratomas upon transplantation, whereas the cells differentiated in adherent culture lost these characteristics. Conclusions This study demonstrates that although cardiomyocyte differentiation can be achieved in stirred suspension bioreactors, the addition of medium enhancers is not adequate to force complete differentiation as fluid shear forces appear to maintain a subpopulation of cells in a transient pluripotent state. The development of successful ESC differentiation protocols within

  2. Impact of stirred suspension bioreactor culture on the differentiation of murine embryonic stem cells into cardiomyocytes

    Directory of Open Access Journals (Sweden)

    Shafa Mehdi

    2011-12-01

    Full Text Available Abstract Background Embryonic stem cells (ESCs can proliferate endlessly and are able to differentiate into all cell lineages that make up the adult organism. Under particular in vitro culture conditions, ESCs can be expanded and induced to differentiate into cardiomyocytes in stirred suspension bioreactors (SSBs. However, in using these systems we must be cognizant of the mechanical forces acting upon the cells. The effect of mechanical forces and shear stress on ESC pluripotency and differentiation has yet to be clarified. The purpose of this study was to investigate the impact of the suspension culture environment on ESC pluripotency during cardiomyocyte differentiation. Results Murine D3-MHC-neor ESCs formed embyroid bodies (EBs and differentiated into cardiomyocytes over 25 days in static culture and suspension bioreactors. G418 (Geneticin was used in both systems from day 10 to enrich for cardiomyocytes by eliminating non-resistant, undifferentiated cells. Treatment of EBs with 1 mM ascorbic acid and 0.5% dimethyl sulfoxide from day 3 markedly increased the number of beating EBs, which displayed spontaneous and cadenced contractile beating on day 11 in the bioreactor. Our results showed that the bioreactor differentiated cells displayed the characteristics of fully functional cardiomyocytes. Remarkably, however, our results demonstrated that the bioreactor differentiated ESCs retained their ability to express pluripotency markers, to form ESC-like colonies, and to generate teratomas upon transplantation, whereas the cells differentiated in adherent culture lost these characteristics. Conclusions This study demonstrates that although cardiomyocyte differentiation can be achieved in stirred suspension bioreactors, the addition of medium enhancers is not adequate to force complete differentiation as fluid shear forces appear to maintain a subpopulation of cells in a transient pluripotent state. The development of successful ESC

  3. Inhibition of Murine Pulmonary Microvascular Endothelial Cell Apoptosis Promotes Recovery of Barrier Function under Septic Conditions

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    Lefeng Wang

    2017-01-01

    Full Text Available Sepsis is characterized by injury of the pulmonary microvasculature and the pulmonary microvascular endothelial cells (PMVEC, leading to barrier dysfunction and acute respiratory distress syndrome (ARDS. Our recent work identified a strong correlation between PMVEC apoptosis and microvascular leak in septic mice in vivo, but the specific role of apoptosis in septic PMVEC barrier dysfunction remains unclear. Thus, we hypothesize that PMVEC apoptosis is likely required for PMVEC barrier dysfunction under septic conditions in vitro. Septic stimulation (mixture of tumour necrosis factor α, interleukin 1β, and interferon γ [cytomix] of isolated murine PMVEC resulted in a significant loss of barrier function as early as 4 h after stimulation, which persisted until 24 h. PMVEC apoptosis, as reflected by caspase activation, DNA fragmentation, and loss of membrane polarity, was first apparent at 8 h after cytomix. Pretreatment of PMVEC with the pan-caspase inhibitor Q-VD significantly decreased septic PMVEC apoptosis and was associated with reestablishment of PMVEC barrier function at 16 and 24 h after stimulation but had no effect on septic PMVEC barrier dysfunction over the first 8 h. Collectively, our data suggest that early septic murine PMVEC barrier dysfunction driven by proinflammatory cytokines is not mediated through apoptosis, but PMVEC apoptosis contributes to late septic PMVEC barrier dysfunction.

  4. Pathogen sensing pathways in human embryonic stem cell derived-endothelial cells: role of NOD1 receptors.

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    Daniel M Reed

    Full Text Available Human embryonic stem cell-derived endothelial cells (hESC-EC, as well as other stem cell derived endothelial cells, have a range of applications in cardiovascular research and disease treatment. Endothelial cells sense Gram-negative bacteria via the pattern recognition receptors (PRR Toll-like receptor (TLR-4 and nucleotide-binding oligomerisation domain-containing protein (NOD-1. These pathways are important in terms of sensing infection, but TLR4 is also associated with vascular inflammation and atherosclerosis. Here, we have compared TLR4 and NOD1 responses in hESC-EC with those of endothelial cells derived from other stem cells and with human umbilical vein endothelial cells (HUVEC. HUVEC, endothelial cells derived from blood progenitors (blood outgrowth endothelial cells; BOEC, and from induced pluripotent stem cells all displayed both a TLR4 and NOD1 response. However, hESC-EC had no TLR4 function, but did have functional NOD1 receptors. In vivo conditioning in nude rats did not confer TLR4 expression in hESC-EC. Despite having no TLR4 function, hESC-EC sensed Gram-negative bacteria, a response that was found to be mediated by NOD1 and the associated RIP2 signalling pathways. Thus, hESC-EC are TLR4 deficient but respond to bacteria via NOD1. This data suggests that hESC-EC may be protected from unwanted TLR4-mediated vascular inflammation, thus offering a potential therapeutic advantage.

  5. [Long-term subculture and biological characterization of the murine bone marrow endothelial cell line].

    Science.gov (United States)

    Huang, Chang; Zhu, Wen-Biao; Zhu, Hai-Ling; Wang, Bao-He; Wang, Qi-Ru

    2007-12-01

    The murine bone marrow endothelial cell line (mBMEC) has been maintained by means of subculture and cryopreservation for over 10 years since it was established in our laboratory. This study was aimed to newly identify biological characteristics of this cell line for further study. The cultured mBMEC cells were observed by inverted microscopy and transmission electron microscopy (TEM). PECAM-1 (CD31) and von Willebrand factor (vWF) were detected by immunofluorescent staining. The phagocytotic activity of the cells in culture was tested by using fluorescent acetylated low-density lipoprotein (Dil-Ac-LDL). The cell growth kinetics analysis and karyotype analysis were performed. The results showed that the adherent cells were mostly elliptical, rounded and spindle-shaped, and some of them connected to each other to form cord- and network-like arrangements in mBMEC cultures at subconfluence. The adherent cells grew up to confluence as a cobblestone-like monolayer. Several ultrastructural features of the endothelial cells could be observed in TEM sections of the cultured cells. More than 94% of mBMEC cells were positive for either CD31 or vWF. The phagocytotic ingestion of Dil-Ac-LDL occurred in 98.5% of cells. In normal culture conditions, the cells grew with a mean population doubling time of 54.6 hours and the maximal mitotic index was 38 per thousand in the rapid growth period. The colony yields were 4.33% to 7.40% depending on the plating density of cells. Karyotypes of all the cells were aneuploidy with a greater percentage of hyperdiploid. It is concluded that mBMEC cells retain the fundamental properties of endothelial cells, but the growth kinetics and biological behaviors are slightly different from those in the early days after the establishment of this cell line.

  6. Endothelial reconstitution by CD34+ progenitors derived from baboon embryonic stem cells.

    Science.gov (United States)

    Shi, Qiang; Schatten, Gerald; Hodara, Vida; Simerly, Calvin; VandeBerg, John L

    2013-02-01

    In this study, we used a large non-human primate model, the baboon, to establish a step-wise protocol to generate CD34+ endothelial progenitor cells (EPCs) from embryonic stem cells (ESCs) and to demonstrate their reparative effects. Baboon ESCs were sequentially differentiated from embryoid body cultures for 9 days and then were specified into EPCs by culturing them in monolayer for 12 days. The resulting EPCs expressed CD34, CXCR4 and UEA-1, but neither CD31 nor CD117. The EPCs were able to form intact lumen structures when seeded on Matrigel, took up Dil-LDL, and responded to TNF-α. Angioblasts specified in EGM-2 medium and ECGS medium had 6.41 ± 1.16% (n = 3) and 9.32 ± 3.73% CD34+ cells (n = 3). The efficiency of generating CD34+ EPCs did not differ significantly from ECGS to EGM-2 culture media, however, angioblasts specified in ECGS medium expressed a higher percentage of CD34+/CXCR4+ cells (3.49 ± 1.32%, n = 3) than those specified in EGM-2 medium (0.49 ± 0.52%, n = 3). To observe their reparative capacity, we purified CD34+ progenitors after specification by EGM-2 medium; inoculated fluorescently labelled CD34+ EPCs into an arterial segment denuded of endothelium in an ex vivo system. After 14 days of ex vivo culture, the grafted cells had attached and integrated to the denuded surface; in addition, they had matured further and expressed terminally differentiated endothelial markers including CD31 and CD146. In conclusion, we have proved that specified CD34+ EPCs are promising therapeutic agents for repairing damaged vasculature.

  7. The phosphatase PTP-PEST/PTPN12 regulates endothelial cell migration and adhesion, but not permeability, and controls vascular development and embryonic viability.

    Science.gov (United States)

    Souza, Cleiton Martins; Davidson, Dominique; Rhee, Inmoo; Gratton, Jean-Philippe; Davis, Elaine C; Veillette, André

    2012-12-14

    Protein-tyrosine phosphatase (PTP)-PEST (PTPN12) is ubiquitously expressed. It is essential for normal embryonic development and embryonic viability in mice. Herein we addressed the involvement of PTP-PEST in endothelial cell functions using a combination of genetic and biochemical approaches. By generating primary endothelial cells from an inducible PTP-PEST-deficient mouse, we found that PTP-PEST is not needed for endothelial cell differentiation and proliferation or for the control of endothelial cell permeability. Nevertheless, it is required for integrin-mediated adhesion and migration of endothelial cells. PTP-PEST-deficient endothelial cells displayed increased tyrosine phosphorylation of Cas, paxillin, and Pyk2, which were previously also implicated in integrin functions. By eliminating PTP-PEST in endothelial cells in vivo, we obtained evidence that expression of PTP-PEST in endothelial cells is required for normal vascular development and embryonic viability. Therefore, PTP-PEST is a key regulator of integrin-mediated functions in endothelial cells seemingly through its capacity to control Cas, paxillin, and Pyk2. This function explains at least in part the essential role of PTP-PEST in embryonic development and viability.

  8. Large-scale identification of microRNA targets in murine Dgcr8-deficient embryonic stem cell lines.

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    Matthew P A Davis

    Full Text Available Small RNAs such as microRNAs play important roles in embryonic stem cell maintenance and differentiation. A broad range of microRNAs is expressed in embryonic stem cells while only a fraction of their targets have been identified. We have performed large-scale identification of embryonic stem cell microRNA targets using a murine embryonic stem cell line deficient in the expression of Dgcr8. These cells are heavily depleted for microRNAs, allowing us to reintroduce specific microRNA duplexes and identify refined target sets. We used deep sequencing of small RNAs, mRNA expression profiling and bioinformatics analysis of microRNA seed matches in 3' UTRs to identify target transcripts. Consequently, we have identified a network of microRNAs that converge on the regulation of several important cellular pathways. Additionally, our experiments have revealed a novel candidate for Dgcr8-independent microRNA genesis and highlighted the challenges currently facing miRNA annotation.

  9. A boost of BMP4 accelerates the commitment of human embryonic stem cells to the endothelial lineage.

    Science.gov (United States)

    Goldman, Orit; Feraud, Olivier; Boyer-Di Ponio, Julie; Driancourt, Catherine; Clay, Denis; Le Bousse-Kerdiles, Marie-Caroline; Bennaceur-Griscelli, Annelise; Uzan, Georges

    2009-08-01

    Embryoid bodies (EBs) generated during differentiation of human embryonic stem cells (hESCs) contain vascular-like structures, suggesting that commitment of mesoderm progenitors into endothelial cells occurs spontaneously. We showed that bone morphogenetic protein 4 (BMP4), an inducer of mesoderm, accelerates the peak expression of CD133/kinase insert domain-containing receptor (KDR) and CD144/KDR. Because the CD133(+)KDR(+) population could represent endothelial progenitors, we sorted them at day 7 and cultured them in endothelial medium. These cells were, however, unable to differentiate into endothelial cells. Under standard conditions, the CD144(+)KDR(+) population represents up to 10% of the total cells at day 12. In culture, these cells, if sorted, give rise to a homogeneous population with a morphology typical of endothelial cells and express endothelial markers. These endothelial cells derived from the day 12 sorted population were functional, as assessed by different in vitro assays. When EBs were stimulated by BMP4, the CD144(+)KDR(+) peak was shifted to day 7. Most of these cells, however, were CD31(-), becoming CD31(+) in culture. They then expressed von Willebrand factor and were functional. This suggests that, initially, the BMP4-boosted day 7, CD144(+)KDR(+)CD31(-) population represents immature endothelial cells that differentiate into mature endothelial cells in culture. The expression of OCT3/4, a marker of immaturity for hESCs decreases during EB differentiation, decreasing faster following BMP4 induction. We also show that BMP4 inhibits the global expression of GATA2 and RUNX1, two transcription factors involved in hemangioblast formation, at day 7 and day 12.

  10. Histone Demethylases KDM4A and KDM4C Regulate Differentiation of Embryonic Stem Cells to Endothelial Cells

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    Liangtang Wu

    2015-07-01

    Full Text Available Understanding epigenetic mechanisms regulating embryonic stem cell (ESC differentiation to endothelial cells may lead to increased efficiency of generation of vessel wall endothelial cells needed for vascular engineering. Here we demonstrated that the histone demethylases KDM4A and KDM4C played an indispensable but independent role in mediating the expression of fetal liver kinase (Flk1 and VE-cadherin, respectively, and thereby the transition of mouse ESCs (mESCs to endothelial cells. KDM4A was shown to bind to histones associated with the Flk1 promoter and KDM4C to bind to histones associated with the VE-cadherin promoter. KDM4A and KDM4C were also both required for capillary tube formation and vasculogenesis in mice. We observed in zebrafish that KDM4A depletion induced more severe vasculogenesis defects than KDM4C depletion, reflecting the early involvement of KDM4A in specifying endothelial cell fate. These findings together demonstrate the essential role of KDM4A and KDM4C in orchestrating mESC differentiation to endothelial cells through the activation of Flk1 and VE-cadherin promoters, respectively.

  11. Increased endothelial cell-leukocyte interaction in murine schistosomiasis: possible priming of endothelial cells by the disease.

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    Suellen D S Oliveira

    Full Text Available BACKGROUND AND AIMS: Schistosomiasis is an intravascular parasitic disease associated with inflammation. Endothelial cells control leukocyte transmigration and vascular permeability being modulated by pro-inflammatory mediators. Recent data have shown that endothelial cells primed in vivo in the course of a disease keep the information in culture. Herein, we evaluated the impact of schistosomiasis on endothelial cell-regulated events in vivo and in vitro. METHODOLOGY AND PRINCIPAL FINDINGS: The experimental groups consisted of Schistosoma mansoni-infected and age-matched control mice. In vivo infection caused a marked influx of leukocytes and an increased protein leakage in the peritoneal cavity, characterizing an inflamed vascular and cellular profile. In vitro leukocyte-mesenteric endothelial cell adhesion was higher in cultured cells from infected mice as compared to controls, either in the basal condition or after treatment with the pro-inflammatory cytokine tumor necrosis factor (TNF. Nitric oxide (NO donation reduced leukocyte adhesion to endothelial cells from control and infected groups; however, in the later group the effect was more pronounced, probably due to a reduced NO production. Inhibition of control endothelial NO synthase (eNOS increased leukocyte adhesion to a level similar to the one observed in the infected group. Besides, the adhesion of control leukocytes to endothelial cells from infected animals is similar to the result of infected animals, confirming that schistosomiasis alters endothelial cells function. Furthermore, NO production as well as the expression of eNOS were reduced in cultured endothelial cells from infected animals. On the other hand, the expression of its repressor protein, namely caveolin-1, was similar in both control and infected groups. CONCLUSION/SIGNIFICANCE: Schistosomiasis increases vascular permeability and endothelial cell-leukocyte interaction in vivo and in vitro. These effects are partially

  12. T-cell intracellular antigen (TIA-proteins deficiency in murine embryonic fibroblasts alters cell cycle progression and induces autophagy.

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    Carmen Sánchez-Jiménez

    Full Text Available Mice lacking either T-cell intracellular antigen 1 (TIA1 or TIA1 related/like protein (TIAR/TIAL1 show high rates of embryonic lethality, suggesting a relevant role for these proteins during embryonic development. However, intrinsic molecular and cellular consequences of either TIA1 or TIAR deficiency remain poorly defined. By using genome-wide expression profiling approach, we demonstrate that either TIA1 or TIAR inactivation broadly alter normal development-associated signalling pathways in murine embryonic fibroblasts (MEF. Indeed, these analyses highlighted alterations of cytokine-cytokine and ECM-receptor interactions and Wnt, MAPK, TGF-beta dependent signalling pathways. Consistent with these results, TIA1 and TIAR knockout (KO MEF show reduced rates of cell proliferation, cell cycle progression delay and increased cell size. Furthermore, TIA-proteins deficiency also caused metabolic deficiencies, increased ROS levels and DNA damage, promoting a gentle rise of cell death. Concomitantly, high rates of autophagy were detected in both TIA1 and TIAR KO MEF with induction of the formation of autophagosomes, as evidenced by the up-regulation of the LC3B protein, and autolysosomes, measured by colocalization of LC3B and LAMP1, as a survival mechanism attempt. Taken together, these observations support that TIA proteins orchestrate a transcriptome programme to activate specific developmental decisions. This program is likely to contribute to mouse physiology starting at early stages of the embryonic development. TIA1/TIAR might function as cell sensors to maintain homeostasis and promote adaptation/survival responses to developmental stress.

  13. A preliminary study on the teratogenesis of dexamethasone and the preventive effect of vitamin B12 on murine embryonic palatal shelf fusion in vitro

    Institute of Scientific and Technical Information of China (English)

    Sheng-jun LU; Wei HE; Bing SHI; Tian MENG; Xiao-yu LI; Yu-rong LIU

    2008-01-01

    Excessive dexamethasone (Dex) administrated into pregnant mice during critical periods of palatal development can produce a high incidence of cleft palate. Its mechanisms remain unknown. Vitamin B12 has been shown to antagonize the tera-togenic effects of Dex, which, however, remains controversial. In this study, we investigated the effects of Dex and vitamin B,2 on murine embryonic palatal shelf fusion using organ culture of murine embryonic shelves. The explanted palatal shelves on embryonic day 14 (E14) were cultured for 24,48,72 or 96 h in different concentrations of Dex and/or vitamin B12. The palatal shelves were examined histologically for the morphological alterations on the medial edge epithelium (MEE) and fusion rates among different groups. It was found that the palatal shelves were not fused at 72 h or less of culture in Dex group, while they were completely fused in the control and vitamin B12-treated groups at 72 and 96 h, respectively. The MEE still existed and proliferated. In Dex+vitamin B12 group the palatal shelves were fused at each time point in a similar rate to controls. These results may suggest that Dex causes teratogenesis of murine embryonic palatal shelves and vitamin B12 prevents the teratogenic effect of Dex on palatogenesis on murine embryos in vitro.

  14. Maintenance and induction of murine embryonic stem cell differentiation using E-cadherin-Fc substrata without colony formation

    Institute of Scientific and Technical Information of China (English)

    Qing-Yuan MENG; Toshihiro AKAIKE

    2013-01-01

    Induced embryonic stem resources for the observation of the cell (ES) cells are expected to be promising cell behaviors in developmental biology as well as the implantation in cell treatments in human diseases. A recombinant E-cadherin substratum was developed as a cell recognizable substratum to maintain the ES cells' self-renewal and pluripotency at single cell level. Furthermore, the generation of various cell lineages in different germ layers, including hepatic or neural cells, was achieved on the chimeric protein layer precisely and effectively. The induction and isolation of specific cell population was carried out with the enhancing effect of other artificial extracellular matrices (ECMs) in enzyme-free process. The murine ES cell-derived cells showed highly morphological similarities and functional expressions to matured hepatocytes or neural progenitor cells.

  15. Maintenance and induction of murine embryonic stem cell differentiation using E-cadherin-Fc substrata without colony formation

    Science.gov (United States)

    Meng, Qing-Yuan; Akaike, Toshihiro

    2013-03-01

    Induced embryonic stem (ES) cells are expected to be promising cell resources for the observation of the cell behaviors in developmental biology as well as the implantation in cell treatments in human diseases. A recombinant E-cadherin substratum was developed as a cell recognizable substratum to maintain the ES cells' self-renewal and pluripotency at single cell level. Furthermore, the generation of various cell lineages in different germ layers, including hepatic or neural cells, was achieved on the chimeric protein layer precisely and effectively. The induction and isolation of specific cell population was carried out with the enhancing effect of other artificial extracellular matrices (ECMs) in enzyme-free process. The murine ES cell-derived cells showed highly morphological similarities and functional expressions to matured hepatocytes or neural progenitor cells.

  16. Differentiation of Human Embryonic Stem Cells to Endothelial Progenitor Cells on Laminins in Defined and Xeno-free Systems

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    Mien T.X. Nguyen

    2016-10-01

    Full Text Available A major hurdle for in vitro culturing of primary endothelial cells (ECs is that they readily dedifferentiate, hampering their use for therapeutic applications. Human embryonic stem cells (hESCs may provide an unlimited cell source; however, most current protocols deriving endothelial progenitor cells (EPCs from hESCs use direct differentiation approaches albeit on undefined matrices, yet final yields are insufficient. We developed a method to culture monolayer hESCs on stem cell niche laminin (LN LN511 or LN521 matrix. Here, we report a chemically defined, xeno-free protocol for differentiation of hESCs to EPCs using LN521 as the main culture substrate. We were able to generate ∼95% functional EPCs defined as VEGFR2+CD34+CD31+VE-Cadherin+. RNA-sequencing analyses of hESCs, EPCs, and primary human umbilical vein endothelial cells showed differentiation-related EC expression signatures, regarding basement membrane composition, cell-matrix interactions, and changes in endothelial lineage markers. Our results may facilitate production of stable ECs for the treatment of vascular diseases and in vitro cell modeling.

  17. Best practice for passaging murine embryonic enteric neuronal cell line before differentiation

    NARCIS (Netherlands)

    Rietdijk, Carmen D.; de Haan, Lydia; van Wezel, Richard J. A.; Garssen, Johan; Kraneveld, Aletta D.

    2016-01-01

    The enteric nervous system (ENS) is a complex network of neurons in the gut, regulating many local, vital functions of the gastro-intestinal tract. The ENS is also part of the bidirectional gut-brain axis. The murine immorto fetal enteric neuronal (IM-FEN) cell line was chosen as a model to study en

  18. Pure populations of murine macrophages from cultured embryonic stem cells. Application to studies of chemotaxis and apoptotic cell clearance.

    Science.gov (United States)

    Zhuang, Lihui; Pound, John D; Willems, Jorine J L P; Taylor, A Helen; Forrester, Lesley M; Gregory, Christopher D

    2012-11-30

    Embryonic stem cells provide a potentially convenient source of macrophages in the laboratory. Given the propensity of macrophages for plasticity in phenotype and function, standardised culture and differentiation protocols are required to ensure consistency in population output and activity in functional assays. Here we detail the development of an optimised culture protocol for the production of murine embryonic stem cell-derived macrophages (ESDM). This protocol provides improved yields of ESDM and we demonstrate that the cells are suitable for application to the study of macrophage responses to apoptotic cells. ESDM so produced were of higher purity than commonly used primary macrophage preparations and were functional in chemotaxis assays and in phagocytosis of apoptotic cells. Maturation of ESDM was found to be associated with reduced capacity for directed migration and increased capacity for phagocytic clearance of apoptotic cells. These results show ESDM to be functionally active in sequential phases of interaction with apoptotic cells and establish these macrophage populations as useful models for further study of molecular mechanisms underlying the recognition and removal of apoptotic cells. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Delayed Mesoderm and Erythroid Differentiation of Murine Embryonic Stem Cells in the Absence of the Transcriptional Regulator FUBP1

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    Josephine Wesely

    2017-01-01

    Full Text Available The transcriptional regulator far upstream binding protein 1 (FUBP1 is essential for fetal and adult hematopoietic stem cell (HSC self-renewal, and the constitutive absence of FUBP1 activity during early development leads to embryonic lethality in homozygous mutant mice. To investigate the role of FUBP1 in murine embryonic stem cells (ESCs and in particular during differentiation into hematopoietic lineages, we generated Fubp1 knockout (KO ESC clones using CRISPR/Cas9 technology. Although FUBP1 is expressed in undifferentiated ESCs and during spontaneous differentiation following aggregation into embryoid bodies (EBs, absence of FUBP1 did not affect ESC maintenance. Interestingly, we observed a delayed differentiation of FUBP1-deficient ESCs into the mesoderm germ layer, as indicated by impaired expression of several mesoderm markers including Brachyury at an early time point of ESC differentiation upon aggregation to EBs. Coculture experiments with OP9 cells in the presence of erythropoietin revealed a diminished differentiation capacity of Fubp1 KO ESCs into the erythroid lineage. Our data showed that FUBP1 is important for the onset of mesoderm differentiation and maturation of hematopoietic progenitor cells into the erythroid lineage, a finding that is supported by the phenotype of FUBP1-deficient mice.

  20. Human and murine very small embryonic-like cells represent multipotent tissue progenitors, in vitro and in vivo.

    Science.gov (United States)

    Havens, Aaron M; Sun, Hongli; Shiozawa, Yusuke; Jung, Younghun; Wang, Jingcheng; Mishra, Anjali; Jiang, Yajuan; O'Neill, David W; Krebsbach, Paul H; Rodgerson, Denis O; Taichman, Russell S

    2014-04-01

    The purpose of this study was to determine the lineage progression of human and murine very small embryonic-like (HuVSEL or MuVSEL) cells in vitro and in vivo. In vitro, HuVSEL and MuVSEL cells differentiated into cells of all three embryonic germ layers. HuVSEL cells produced robust mineralized tissue of human origin compared with controls in calvarial defects. Immunohistochemistry demonstrated that the HuVSEL cells gave rise to neurons, adipocytes, chondrocytes, and osteoblasts within the calvarial defects. MuVSEL cells were also able to differentiate into similar lineages. First round serial transplants of MuVSEL cells into irradiated osseous sites demonstrated that ∼60% of the cells maintained their VSEL cell phenotype while other cells differentiated into multiple tissues at 3 months. Secondary transplants did not identify donor VSEL cells, suggesting limited self renewal but did demonstrate VSEL cell derivatives in situ for up to 1 year. At no point were teratomas identified. These studies show that VSEL cells produce multiple cellular structures in vivo and in vitro and lay the foundation for future cell-based regenerative therapies for osseous, neural, and connective tissue disorders.

  1. Establishment of new murine embryonic stem cell lines for the generation of mouse models of human genetic diseases

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    M.A. Sukoyan

    2002-05-01

    Full Text Available Embryonic stem cells are totipotent cells derived from the inner cell mass of blastocysts. Recently, the development of appropriate culture conditions for the differentiation of these cells into specific cell types has permitted their use as potential therapeutic agents for several diseases. In addition, manipulation of their genome in vitro allows the creation of animal models of human genetic diseases and for the study of gene function in vivo. We report the establishment of new lines of murine embryonic stem cells from preimplantation stage embryos of 129/Sv mice. Most of these cells had a normal karyotype and an XY sex chromosome composition. The pluripotent properties of the cell lines obtained were analyzed on the basis of their alkaline phosphatase activity and their capacity to form complex embryoid bodies with rhythmically contracting cardiomyocytes. Two lines, USP-1 and USP-3, with the best in vitro characteristics of pluripotency were used in chimera-generating experiments. The capacity to contribute to the germ line was demonstrated by the USP-1 cell line. This cell line is currently being used to generate mouse models of human diseases.

  2. The CMV early enhancer/chicken beta actin (CAG) promoter can be used to drive transgene expression during the differentiation of murine embryonic stem cells into vascular progenitors

    DEFF Research Database (Denmark)

    Alexopoulou, Annika N; Couchman, John R; Whiteford, James

    2008-01-01

    . RESULTS: CCE mouse embryonic stem cells were differentiated on collagen type IV for 4-5 days, Flk1+ mesodermal cells were sorted and replated either on collagen type IV in the presence of VEGFA to give rise to endothelial cells and smooth muscle cells or in collagen type I gels for the formation...

  3. Red light, green light: Signals that control endothelial cell proliferation during embryonic vascular development

    Science.gov (United States)

    The proper regulation of endothelial cell proliferation is critical for vascular development in the embryo. VEGF-A and bFGF, which are important in the induction of mesodermal progenitors to form a capillary plexus, are also key mitogenic signals. Disruption in VEGF-A or bFGF decreases endothelial c...

  4. Pluripotency factors and Polycomb Group proteins repress aryl hydrocarbon receptor expression in murine embryonic stem cells

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    Chia-I Ko

    2014-01-01

    Full Text Available The aryl hydrocarbon receptor (AHR is a transcription factor and environmental sensor that regulates expression of genes involved in drug-metabolism and cell cycle regulation. Chromatin immunoprecipitation analyses, Ahr ablation in mice and studies with orthologous genes in invertebrates suggest that AHR may also play a significant role in embryonic development. To address this hypothesis, we studied the regulation of Ahr expression in mouse embryonic stem cells and their differentiated progeny. In ES cells, interactions between OCT3/4, NANOG, SOX2 and Polycomb Group proteins at the Ahr promoter repress AHR expression, which can also be repressed by ectopic expression of reprogramming factors in hepatoma cells. In ES cells, unproductive RNA polymerase II binds at the Ahr transcription start site and drives the synthesis of short abortive transcripts. Activation of Ahr expression during differentiation follows from reversal of repressive marks in Ahr promoter chromatin, release of pluripotency factors and PcG proteins, binding of Sp factors, establishment of histone marks of open chromatin, and engagement of active RNAPII to drive full-length RNA transcript elongation. Our results suggest that reversible Ahr repression in ES cells holds the gene poised for expression and allows for a quick switch to activation during embryonic development.

  5. Pluripotency factors and Polycomb Group proteins repress aryl hydrocarbon receptor expression in murine embryonic stem cells.

    Science.gov (United States)

    Ko, Chia-I; Wang, Qin; Fan, Yunxia; Xia, Ying; Puga, Alvaro

    2014-01-01

    The aryl hydrocarbon receptor (AHR) is a transcription factor and environmental sensor that regulates expression of genes involved in drug-metabolism and cell cycle regulation. Chromatin immunoprecipitation analyses, Ahr ablation in mice and studies with orthologous genes in invertebrates suggest that AHR may also play a significant role in embryonic development. To address this hypothesis, we studied the regulation of Ahr expression in mouse embryonic stem cells and their differentiated progeny. In ES cells, interactions between OCT3/4, NANOG, SOX2 and Polycomb Group proteins at the Ahr promoter repress AHR expression, which can also be repressed by ectopic expression of reprogramming factors in hepatoma cells. In ES cells, unproductive RNA polymerase II binds at the Ahr transcription start site and drives the synthesis of short abortive transcripts. Activation of Ahr expression during differentiation follows from reversal of repressive marks in Ahr promoter chromatin, release of pluripotency factors and PcG proteins, binding of Sp factors, establishment of histone marks of open chromatin, and engagement of active RNAPII to drive full-length RNA transcript elongation. Our results suggest that reversible Ahr repression in ES cells holds the gene poised for expression and allows for a quick switch to activation during embryonic development.

  6. Murine cerebrovascular cells as a cell culture model for cerebral amyloid angiopathy: isolation of smooth muscle and endothelial cells from mouse brain.

    Science.gov (United States)

    Gauthier, Sebastien A; Sahoo, Susmita; Jung, Sonia S; Levy, Efrat

    2012-01-01

    The use of murine cerebrovascular endothelial and smooth muscle cells has not been widely employed as a cell culture model for the investigation of cellular mechanisms involved in cerebral amyloid angiopathy (CAA). Difficulties in isolation and propagation of murine cerebrovascular cells and insufficient yields for molecular and cell culture studies have deterred investigators from using mice as a source for cerebrovascular cells in culture. Instead, cerebrovascular cells from larger mammals are preferred and several methods describing the isolation of endothelial and smooth muscle cells from human, canine, rat, and guinea pig have been published. In recent years, several transgenic mouse lines showing CAA pathology have been established; consequently murine cerebrovascular cells derived from these animals can serve as a key cellular model to study CAA. Here, we describe a procedure for isolating murine microvessels that yields healthy smooth muscle and endothelial cell populations and produce sufficient material for experimental purposes. Murine smooth muscle cells isolated using this protocol exhibit the classic "hill and valley" morphology and are immunoreactive for the smooth muscle cell marker α-actin. Endothelial cells display a "cobblestone" pattern phenotype and show the characteristic immunostaining for the von Willebrand factor and the factor VIII-related antigen. In addition, we describe methods designed to preserve these cells by storage in liquid nitrogen and reestablishing viable cell cultures. Finally, we compare our methods with protocols designed to isolate and maintain human cerebrovascular cell cultures.

  7. Reversal of endothelial progenitor cell dysfunction in patients with type 2 diabetes using a conditioned medium of human embryonic stem cell-derived endothelial cells.

    Science.gov (United States)

    Ho, Jenny C Y; Lai, Wing-Hon; Li, Ming-Fang; Au, Ka-Wing; Yip, Mei-Chu; Wong, Navy L Y; Ng, Ethel S K; Lam, Francis F Y; Siu, Chung-Wah; Tse, Hung-Fat

    2012-07-01

    The potential clinical application of bone marrow or peripheral blood-derived progenitor cells for cardiovascular regeneration in patients with diabetes mellitus (DM) is limited by their functional impairment. We sought to determine the mechanisms of impaired therapeutic efficacy of peripheral blood-derived progenitor cells in type 2 DM patients and evaluated the use of cell-free conditioned medium obtained from human embryonic stem cell-derived endothelial-like cells (ESC-ECs) to reverse their functional impairment. The angiogenic potential of late outgrowth endothelial cells (OECs) and cytokine profile of the conditional medium of proangiogenic cells (PACs) derived from peripheral blood-mononuclear cells of healthy control and DM patients and ESC-ECs was compared by in vitro tube formation assay and a multiplex bead-based immunoassay kit, respectively. The in vivo angiogenic potential of ESC-ECs derived conditioned medium in rescuing the functional impairment of PB-PACs in DM patients was investigated using a hindlimb ischemia model. Human ESC-ECs had similar functional and phenotypic characteristics as OECs in healthy controls. Cytokine profiling showed that vascular endothelial growth factor, stromal cell-derived factor 1 and placental growth factor were down-regulated in PACs from DM patients. Tube formation assay that revealed functional impairment of OECs from DM patients could be rescued by ESC-ECs conditioned medium. Administration of ESC-ECs conditioned medium restored the therapeutic efficacy of PB-PACs from DM patients in a mouse model of hindlimb ischemia. Our results showed that peripheral blood-derived progenitor cells from DM patients have impaired function because of defective secretion of angiogenic cytokines, which could be restored by supplementation of ESC-ECs conditioned medium. Copyright © 2012 John Wiley & Sons, Ltd.

  8. Maternal and embryonic control of uterine sphingolipid-metabolizing enzymes during murine embryo implantation.

    Science.gov (United States)

    Kaneko-Tarui, Tomoko; Zhang, Ling; Austin, Kathleen J; Henkes, Luiz E; Johnson, Joshua; Hansen, Thomas R; Pru, James K

    2007-10-01

    During early gestation in invasively implanting species, the uterine stromal compartment undergoes dramatic remodeling, defined by the differentiation of stromal fibroblast cells into decidual cells. Lipid signaling molecules from a number of pathways are well-established functional components of this decidualization reaction. Because of a correlation in the events that transpire in the uterus during early implantation with known functions of bioactive sphingolipid metabolites established from studies in other organ systems, we hypothesized that uterine sphingolipid metabolism would change during implantation. By a combination of Northern blot, Western blot, and immunohistochemical analyses, we establish that enzymes at each of the major catalytic steps in the sphingolipid cascade become transcriptionally up-regulated in the uterus during decidualization. Each of the enzymes analyzed was up-regulated from Days of Pregnancy (DOP) 4.5-7.5. When comparing embryo-induced decidualization (decidual) with mechanically induced decidualization (deciduomal), sphingomyelin phosphodiesterase 1 (Smpd1) mRNA and sphingosine kinase 1 (SPHK1) protein were shown to be dually regulated in the endometrium by both maternal and embryonic factors. As measured by the diacyl glycerol kinase assay, ceramide levels rose in parallel with Smpd1 gene expression, suggesting that elevated transcription of sphingolipid enzymes results in heightened catalytic activity of the pathway. Altogether, these findings place sphingolipids on a growing list of lipid signaling molecules that become increasingly present at the maternal-embryonic interface.

  9. Stress hormone epinephrine enhances adipogenesis in murine embryonic stem cells by up-regulating the neuropeptide Y system.

    Directory of Open Access Journals (Sweden)

    Ruijun Han

    Full Text Available Prenatal stress, psychologically and metabolically, increases the risk of obesity and diabetes in the progeny. However, the mechanisms of the pathogenesis remain unknown. In adult mice, stress activates NPY and its Y2R in a glucocorticoid-dependent manner in the abdominal fat. This increased adipogenesis and angiogenesis, leading to abdominal obesity and metabolic syndrome which were inhibited by intra-fat Y2R inactivation. To determine whether stress elevates NPY system and accelerates adipogenic potential of embryo, here we "stressed" murine embryonic stem cells (mESCs in vitro with epinephrine (EPI during their adipogenic differentiation. EPI was added during the commitment stage together with insulin, and followed by dexamethasone in the standard adipogenic differentiation medium. Undifferentiated embryonic bodies (EBs showed no detectable expression of NPY. EPI markedly up-regulated the expression NPY and the Y1R at the commitment stage, followed by increased Y2R mRNA at the late of the commitment stage and the differentiation stage. EPI significantly increased EB cells proliferation and expression of the preadipocyte marker Pref-1 at the commitment stage. EPI also accelerated and amplified adipogenic differentiation detected by increasing the adipocyte markers FABP4 and PPARγ mRNAs and Oil-red O-staining at the end of the differentiation stage. EPI-induced adipogenesis was completely prevented by antagonists of the NPY receptors (Y1R+Y2R+Y5R, indicating that it was mediated by the NPY system in mESC's. Taken together, these data suggest that stress may play an important role in programming ESCs for accelerated adipogenesis by altering the stress induced hormonal regulation of the NPY system.

  10. Vitrification by Ultra-fast Cooling at a Low Concentration of Cryoprotectants in a Quartz Microcapillary: A Study Using Murine Embryonic Stem Cells

    OpenAIRE

    He, Xiaoming; Park, Eric Y H; Fowler, Alex; Martin L. Yarmush; Toner, Mehmet

    2008-01-01

    Conventional cryopreservation protocols for slow-freezing or vitrification involve cell injury due to ice formation/cell dehydration or toxicity of high cryoprotectant (CPA) concentrations, respectively. In this study, we developed a novel cryopreservation technique to achieve ultra-fast cooling rates using a quartz microcapillary (QMC). The QMC enabled vitrification of murine embryonic stem (ES) cells using an intracellular cryoprotectant concentration in the range used for slowing freezing ...

  11. Vitrification by ultra-fast cooling at a low concentration of cryoprotectants in a quartz micro-capillary: a study using murine embryonic stem cells.

    Science.gov (United States)

    He, Xiaoming; Park, Eric Y H; Fowler, Alex; Yarmush, Martin L; Toner, Mehmet

    2008-06-01

    Conventional cryopreservation protocols for slow-freezing or vitrification involve cell injury due to ice formation/cell dehydration or toxicity of high cryoprotectant (CPA) concentrations, respectively. In this study, we developed a novel cryopreservation technique to achieve ultra-fast cooling rates using a quartz micro-capillary (QMC). The QMC enabled vitrification of murine embryonic stem (ES) cells using an intracellular cryoprotectant concentration in the range used for slowing freezing (1-2M). The cryoprotectants used included 2M 1,2-propanediol (PROH, cell membrane permeable) and 0.5M extracellular trehalose (cell membrane impermeable). More than 70% of the murine ES cells post-vitrification attached with respect to non-frozen control cells, and the proliferation rates of the two groups were similar. Preservation of undifferentiated properties of the pluripotent murine ES cells post-vitrification cryopreservation was verified using three different types of assays: the expression of transcription factor Oct-4, the presentation of the membrane surface glycoprotein SSEA-1, and the elevated expression of the intracellular enzyme alkaline phosphatase. These results indicate that vitrification at a low concentration (2M) of intracellular cryoprotectants is a viable and effective approach for the cryopreservation of murine embryonic stem cells.

  12. Differentiation of murine embryonic stem cells to thyrocytes requires insulin and insulin-like growth factor-1.

    Science.gov (United States)

    Arufe, Maria C; Lu, Min; Lin, Reigh-Yi

    2009-04-03

    The mechanisms controlling thyrocyte development during embryonic stem (ES) cell differentiation have only been partially elucidated, although previous studies have suggested the participation of thyroid stimulating hormone (TSH) in these processes. To further define the role of TSH in this context, we have studied a murine ES cell line in which green fluorescent protein (GFP) cDNA is targeted to the TSH receptor (TSHR) gene, linking the expression of GFP to the transcription of the endogenous TSHR gene. We demonstrate that, in the initial stages of embryoid body formation, activin A and TSH induce the differentiation of definitive endoderm and thyrocyte progenitors expressing Sox17, Foxa2, and TSHR. These thyrocyte progenitors are then converted into cellular aggregates that, in the presence of insulin and IGF-1, further differentiate into mature thyroglobulin-expressing thyrocytes. Our data suggest that, despite the fact that TSH is important for the induction and specification of thyrocytes from ES cells, insulin and IGF-1 are crucial for thyrocyte maturation. Our method provides a powerful in vitro differentiation model for studying the mechanisms of early thyrocyte lineage development.

  13. Limited gene expression variation in human embryonic stem cell and induced pluripotent stem cell-derived endothelial cells.

    Science.gov (United States)

    White, Mark P; Rufaihah, Abdul J; Liu, Lei; Ghebremariam, Yohannes T; Ivey, Kathryn N; Cooke, John P; Srivastava, Deepak

    2013-01-01

    Recent evidence suggests human embryonic stem cell (hESC) and induced pluripotent stem (iPS) cell lines have differences in their epigenetic marks and transcriptomes, yet the impact of these differences on subsequent terminally differentiated cells is less well understood. Comparison of purified, homogeneous populations of somatic cells derived from multiple independent human iPS and ES lines will be required to address this critical question. Here, we report a differentiation protocol based on embryonic development that consistently yields large numbers of endothelial cells (ECs) derived from multiple hESCs or iPS cells. Mesoderm differentiation of embryoid bodies was maximized, and defined growth factors were used to generate KDR(+) EC progenitors. Magnetic purification of a KDR(+) progenitor subpopulation resulted in an expanding, homogeneous pool of ECs that expressed EC markers and had functional properties of ECs. Comparison of the transcriptomes revealed limited gene expression variability between multiple lines of human iPS-derived ECs or between lines of ES- and iPS-derived ECs. These results demonstrate a method to generate large numbers of pure human EC progenitors and differentiated ECs from pluripotent stem cells and suggest individual lineages derived from human iPS cells may have significantly less variance than their pluripotent founders.

  14. A small molecule-based strategy for endothelial differentiation and three-dimensional morphogenesis from human embryonic stem cells.

    Science.gov (United States)

    Geng, Yijie; Feng, Bradley

    2016-07-01

    The emerging models of human embryonic stem cell (hESC) self-organizing organoids provide a valuable in vitro platform for studying self-organizing processes that presumably mimic in vivo human developmental events. Here we report that through a chemical screen, we identified two novel and structurally similar small molecules BIR1 and BIR2 which robustly induced the self-organization of a balloon-shaped three-dimensional structure when applied to two-dimensional adherent hESC cultures in the absence of growth factors. Gene expression analyses and functional assays demonstrated an endothelial identity of this balloon-like structure, while cell surface marker analyses revealed a VE-cadherin(+)CD31(+)CD34(+)KDR(+)CD43(-) putative endothelial progenitor population. Furthermore, molecular marker labeling and morphological examinations characterized several other distinct DiI-Ac-LDL(+) multi-cellular modules and a VEGFR3(+) sprouting structure in the balloon cultures that likely represented intermediate structures of balloon-formation.

  15. Notch-HES1 signaling axis controls hemato-endothelial fate decisions of human embryonic and induced pluripotent stem cells.

    Science.gov (United States)

    Lee, Jung Bok; Werbowetski-Ogilvie, Tamra E; Lee, Jong-Hee; McIntyre, Brendan A S; Schnerch, Angelique; Hong, Seok-Ho; Park, In-Hyun; Daley, George Q; Bernstein, Irwin D; Bhatia, Mickie

    2013-08-15

    Notch signaling regulates several cellular processes including cell fate decisions and proliferation in both invertebrates and mice. However, comparatively less is known about the role of Notch during early human development. Here, we examined the function of Notch signaling during hematopoietic lineage specification from human pluripotent stem cells of both embryonic and adult fibroblast origin. Using immobilized Notch ligands and small interfering RNA to Notch receptors we have demonstrated that Notch1, but not Notch2, activation induced hairy and enhancer of split 1 (HES1) expression and generation of committed hematopoietic progenitors. Using gain- and loss-of-function approaches, this was shown to be attributed to Notch-signaling regulation through HES1, which dictated cell fate decisions from bipotent precursors either to the endothelial or hematopoietic lineages at the clonal level. Our study reveals a previously unappreciated role for the Notch pathway during early human hematopoiesis, whereby Notch signaling via HES1 represents a toggle switch of hematopoietic vs endothelial fate specification.

  16. Human embryonic stem cell-derived endothelial cells as cellular delivery vehicles for treatment of metastatic breast cancer.

    Science.gov (United States)

    Su, Weijun; Wang, Lina; Zhou, Manqian; Liu, Ze; Hu, Shijun; Tong, Lingling; Liu, Yanhua; Fan, Yan; Kong, Deling; Zheng, Yizhou; Han, Zhongchao; Wu, Joseph C; Xiang, Rong; Li, Zongjin

    2013-01-01

    Endothelial progenitor cells (EPCs) have shown tropism towards primary tumors or metastases and are thus potential vehicles for targeting tumor therapy. However, the source of adult EPCs is limited, which highlights the need for a consistent and renewable source of endothelial cells for clinical applications. Here, we investigated the potential of human embryonic stem cell-derived endothelial cells (hESC-ECs) as cellular delivery vehicles for therapy of metastatic breast cancer. In order to provide an initial assessment of the therapeutic potency of hESC-ECs, we treated human breast cancer MDA-MB-231 cells with hESC-EC conditioned medium (EC-CM) in vitro. The results showed that hESC-ECs could suppress the Wnt/β-catenin signaling pathway and thereby inhibit the proliferation and migration of MDA-MB-231 cells. To track and evaluate the possibility of hESC-EC-employed therapy, we employed the bioluminescence imaging (BLI) technology. To study the therapeutic potential of hESC-ECs, we established lung metastasis models by intravenous injection of MDA-MB-231 cells labeled with firefly luciferase (Fluc) and green fluorescent protein (GFP) to NOD/SCID mice. In mice with lung metastases, we injected hESC-ECs armed with herpes simplex virus truncated thymidine kinase (HSV-ttk) intravenously on days 11, 16, 21, and 26 after MDA-MB-231 cell injection. The NOD/SCID mice were subsequently treated with ganciclovir (GCV), and the growth status of tumor was monitored by Fluc imaging. We found that MDA-MB-231 tumors were significantly inhibited by intravenously injected hESC-ECs. The tumor-suppressive effects of the hESC-ECs, by inhibiting Wnt/β-catenin signaling pathway and inducing tumor cell death through bystander effect in human metastatic breast cancer model, provide previously unexplored therapeutic modalities for cancer treatment.

  17. Vascular progenitor cells isolated from human embryonic stem cells give rise to endothelial and smooth muscle like cells and form vascular networks in vivo.

    Science.gov (United States)

    Ferreira, Lino S; Gerecht, Sharon; Shieh, Hester F; Watson, Nicki; Rupnick, Maria A; Dallabrida, Susan M; Vunjak-Novakovic, Gordana; Langer, Robert

    2007-08-03

    We report that human embryonic stem cells contain a population of vascular progenitor cells that have the ability to differentiate into endothelial-like and smooth muscle (SM)-like cells. Vascular progenitor cells were isolated from EBs grown in suspension for 10 days and were characterized by expression of the endothelial/hematopoietic marker CD34 (CD34+ cells). When these cells are subsequently cultured in EGM-2 (endothelial growth medium) supplemented with vascular endothelial growth factor-165 (50 ng/mL), they give rise to endothelial-like cells characterized by a cobblestone cell morphology, expression of endothelial markers (platelet endothelial cell-adhesion molecule-1, CD34, KDR/Flk-1, vascular endothelial cadherin, von Willebrand factor), incorporation of acetylated low-density lipoprotein, and formation of capillary-like structures when placed in Matrigel. In contrast, when CD34+ cells are cultured in EGM-2 supplemented with platelet-derived growth factor-BB (50 ng/mL), they give rise to SM-like cells characterized by spindle-shape morphology, expression of SM cell markers (alpha-SM actin, SM myosin heavy chain, calponin, caldesmon, SM alpha-22), and the ability to contract and relax in response to common pharmacological agents such as carbachol and atropine but rarely form capillary-like structures when placed in Matrigel. Implantation studies in nude mice show that both cell types contribute to the formation of human microvasculature. Some microvessels contained mouse blood cells, which indicates functional integration with host vasculature. Therefore, the vascular progenitors isolated from human embryonic stem cells using methods established in the present study could provide a means to examine the mechanisms of endothelial and SM cell development, and they could also provide a potential source of cells for vascular tissue engineering.

  18. An increase in telomere sister chromatid exchange in murine embryonic stem cells possessing critically shortened telomeres

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yisong [ORNL; Giannone, Richard J [ORNL; Wu, Jun [ORNL; Gomez, Marla V [ORNL; Liu, Yie [ORNL

    2005-01-01

    Telomerase deficiency leads to a progressive loss of telomeric DNA that eventually triggers cell apoptosis in human primary cells during prolonged growth in culture. Rare survivors can maintain telomere length through either activation of telomerase or recombination-based telomere lengthening, and thus proliferate indefinitely. We have explored the possibility that telomeres may be maintained through telomere sister chromatid exchange (T-SCE) in murine telomere reverse transcriptase-deficient (mTert -/-) splenocytes and ES cells. Because telomerase deficiency leads to gradual loss of telomeric DNA in mTert -/- splenocytes and ES cells and eventually to chromosomes with telomere signal-free ends (SFEs), we examined these cell types for evidence of sister chromatid exchange at telomeres, and observed an increase in T-SCEs only in a subset of mTert -/- splenocytes or ES cells that possessed multiple SFEs. Furthermore, T-SCEs were more often detected in ES cells than in splenocytes that harbored a similar frequency of SFEs. In mTert heterozygous (mTert +/-) ES cells or splenocytes, which are known to exhibit a decrease in average telomere length but no SFEs, no increase in T-SCE was observed. In addition to T-SCE, other genomic rearrangements (i.e., SCE) were also significantly increased in mTert -/- ES cells possessing critically short telomeres, but not in splenocytes. Our results suggest that animals and cell culture differ in their ability to carry out genomic rearrangements as a means of maintaining telomere integrity when telomeres become critically shortened.

  19. Innate immunity in an in vitro murine blastocyst model using embryonic and trophoblast stem cells.

    Science.gov (United States)

    Aikawa, Hiroaki; Tamai, Miho; Mitamura, Keisuke; Itmainati, Fakhria; Barber, Glen N; Tagawa, Yoh-ichi

    2014-03-01

    The immune system has two broad components-innate and adaptive immunity. Adaptive immunity becomes established only after the onset of hematopoiesis, whereas the innate immune system may be actively protecting organisms from microbial invasion much earlier in development. Here, we address the question of whether the innate immune system functions in the early-stage embryo, i.e., the blastocyst. The innate immune system was studied by using in vitro blastocyst models, e.g., embryonic stem (ES) and trophoblast stem (TS) cell cultures. The expression of Toll-like receptors (TLR)-2, -3, and -5 could be detected in both ES and TS cells. The expression of interferon (IFN)-β was induced by the addition of polyinosinic:polycytidylic acid [poly(I:C)] in TS cells, but not ES cells, although TLR-3 was expressed at the same level in both cell types. In turn, ES cells responded to IFN-β exposure by expressing IFN-induced anti-viral genes, e.g., RNA-dependent protein kinase and 2', 5'-oligoadenylate synthetase (OAS). Neither a reduction in ES cell proliferation nor cell death in these cultures was observed after IFN-β stimulation. Furthermore, OAS1a expression was induced in ES/TS co-cultures after poly(I:C) stimulation, but was not induced when either cell type was cultured alone. In conclusion, TS cells react to poly(I:C) stimulation by producing IFN-β, which induces IFN-inducible genes in ES cells. This observation suggests that the trophectoderm, the outer layer of the blastocyst, may respond to viral infection, and then induce anti-viral gene expression via IFN-β signaling to the blastocyst inner cell mass.

  20. Induction and selection of Sox17-expressing endoderm cells generated from murine embryonic stem cells.

    Science.gov (United States)

    Schroeder, Insa S; Sulzbacher, Sabine; Nolden, Tobias; Fuchs, Joerg; Czarnota, Judith; Meisterfeld, Ronny; Himmelbauer, Heinz; Wobus, Anna M

    2012-01-01

    Embryonic stem (ES) cells offer a valuable source for generating insulin-producing cells. However, current differentiation protocols often result in heterogeneous cell populations of various developmental stages. Here we show the activin A-induced differentiation of mouse ES cells carrying a homologous dsRed-IRES-puromycin knock-in within the Sox17 locus into the endoderm lineage. Sox17-expressing cells were selected by fluorescence-assisted cell sorting (FACS) and characterized at the transcript and protein level. Treatment of ES cells with high concentrations of activin A for 10 days resulted in up to 19% Sox17-positive cells selected by FACS. Isolated Sox17-positive cells were characterized by defini- tive endoderm-specific Sox17/Cxcr4/Foxa2 transcripts, but lacked pluripotency-associated Oct4 mRNA and protein. The Sox17-expressing cells showed downregulation of extraembryonic endoderm (Sox7, Afp, Sdf1)-, mesoderm (Foxf1, Meox1)- and ectoderm (Pax6, NeuroD6)-specific transcripts. The presence of Hnf4α, Hes1 and Pdx1 mRNA demonstrated the expression of primitive gut/foregut cell-specific markers. Ngn3, Nkx6.1 and Nkx2.2 transcripts in Sox17-positive cells were determined as properties of pancreatic endocrine progenitors. Immunocytochemistry of activin A-induced Sox17-positive embryoid bodies revealed coexpression of Cxcr4 and Foxa2. Moreover, the histochemical demonstration of E-cadherin-, Cxcr4-, Sox9-, Hnf1β- and Ngn3-positive epithelial-like structures underlined the potential of Sox17-positive cells to further differentiate into the pancreatic lineage. By reducing the heterogeneity of the ES cell progeny, Sox17-expressing cells are a suitable model to evaluate the effects of growth and differentiation factors and of culture conditions to delineate the differentiation process for the generation of pancreatic cells in vitro.

  1. Modeling insertional mutagenesis using gene length and expression in murine embryonic stem cells.

    Directory of Open Access Journals (Sweden)

    Alex S Nord

    Full Text Available BACKGROUND: High-throughput mutagenesis of the mammalian genome is a powerful means to facilitate analysis of gene function. Gene trapping in embryonic stem cells (ESCs is the most widely used form of insertional mutagenesis in mammals. However, the rules governing its efficiency are not fully understood, and the effects of vector design on the likelihood of gene-trapping events have not been tested on a genome-wide scale. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we used public gene-trap data to model gene-trap likelihood. Using the association of gene length and gene expression with gene-trap likelihood, we constructed spline-based regression models that characterize which genes are susceptible and which genes are resistant to gene-trapping techniques. We report results for three classes of gene-trap vectors, showing that both length and expression are significant determinants of trap likelihood for all vectors. Using our models, we also quantitatively identified hotspots of gene-trap activity, which represent loci where the high likelihood of vector insertion is controlled by factors other than length and expression. These formalized statistical models describe a high proportion of the variance in the likelihood of a gene being trapped by expression-dependent vectors and a lower, but still significant, proportion of the variance for vectors that are predicted to be independent of endogenous gene expression. CONCLUSIONS/SIGNIFICANCE: The findings of significant expression and length effects reported here further the understanding of the determinants of vector insertion. Results from this analysis can be applied to help identify other important determinants of this important biological phenomenon and could assist planning of large-scale mutagenesis efforts.

  2. Isolation and culture of neural crest cells from embryonic murine neural tube.

    Science.gov (United States)

    Pfaltzgraff, Elise R; Mundell, Nathan A; Labosky, Patricia A

    2012-06-02

    The embryonic neural crest (NC) is a multipotent progenitor population that originates at the dorsal aspect of the neural tube, undergoes an epithelial to mesenchymal transition (EMT) and migrates throughout the embryo, giving rise to diverse cell types. NC also has the unique ability to influence the differentiation and maturation of target organs. When explanted in vitro, NC progenitors undergo self-renewal, migrate and differentiate into a variety of tissue types including neurons, glia, smooth muscle cells, cartilage and bone. NC multipotency was first described from explants of the avian neural tube. In vitro isolation of NC cells facilitates the study of NC dynamics including proliferation, migration, and multipotency. Further work in the avian and rat systems demonstrated that explanted NC cells retain their NC potential when transplanted back into the embryo. Because these inherent cellular properties are preserved in explanted NC progenitors, the neural tube explant assay provides an attractive option for studying the NC in vitro. To attain a better understanding of the mammalian NC, many methods have been employed to isolate NC populations. NC-derived progenitors can be cultured from post-migratory locations in both the embryo and adult to study the dynamics of post-migratory NC progenitors, however isolation of NC progenitors as they emigrate from the neural tube provides optimal preservation of NC cell potential and migratory properties. Some protocols employ fluorescence activated cell sorting (FACS) to isolate a NC population enriched for particular progenitors. However, when starting with early stage embryos, cell numbers adequate for analyses are difficult to obtain with FACS, complicating the isolation of early NC populations from individual embryos. Here, we describe an approach that does not rely on FACS and results in an approximately 96% pure NC population based on a Wnt1-Cre activated lineage reporter. The method presented here is adapted from

  3. The housekeeping gene hypoxanthine guanine phosphoribosyltransferase (HPRT regulates multiple developmental and metabolic pathways of murine embryonic stem cell neuronal differentiation.

    Directory of Open Access Journals (Sweden)

    Tae Hyuk Kang

    Full Text Available The mechanisms by which mutations of the purinergic housekeeping gene hypoxanthine guanine phosphoribosyltransferase (HPRT cause the severe neurodevelopmental Lesch Nyhan Disease (LND are poorly understood. The best recognized neural consequences of HPRT deficiency are defective basal ganglia expression of the neurotransmitter dopamine (DA and aberrant DA neuronal function. We have reported that HPRT deficiency leads to dysregulated expression of multiple DA-related developmental functions and cellular signaling defects in a variety of HPRT-deficient cells, including human induced pluripotent stem (iPS cells. We now describe results of gene expression studies during neuronal differentiation of HPRT-deficient murine ESD3 embryonic stem cells and report that HPRT knockdown causes a marked switch from neuronal to glial gene expression and dysregulates expression of Sox2 and its regulator, genes vital for stem cell pluripotency and for the neuronal/glial cell fate decision. In addition, HPRT deficiency dysregulates many cellular functions controlling cell cycle and proliferation mechanisms, RNA metabolism, DNA replication and repair, replication stress, lysosome function, membrane trafficking, signaling pathway for platelet activation (SPPA multiple neurotransmission systems and sphingolipid, sulfur and glycan metabolism. We propose that the neural aberrations of HPRT deficiency result from combinatorial effects of these multi-system metabolic errors. Since some of these aberrations are also found in forms of Alzheimer's and Huntington's disease, we predict that some of these systems defects play similar neuropathogenic roles in diverse neurodevelopmental and neurodegenerative diseases in common and may therefore provide new experimental opportunities for clarifying pathogenesis and for devising new potential therapeutic targets in developmental and genetic disease.

  4. Differentiation of embryonic stem cells into endothelial cells%胚胎干细胞向内皮细胞分化

    Institute of Scientific and Technical Information of China (English)

    韩雷; 苗俊英; 苏乐

    2011-01-01

    Cardiovascular disease is one of the main causes of death worldwide. Vascular regeneration and cell therapy provide promising prospect for treating cardiovascular disease. Embryonic stem cells are now the main sources of endothelial cells and tissue engineering materials for cell therapy. In this paper, we reviewed the methods, signaling pathways and transcription factors during the process of embryonic stem cells differentiation into endothelial cells. It provides a systematic approach and theoretical guidance for studying differentiation of embryonic stem cells into vascular endothelial cells. Furthermore, it lays a theoretical basis for treating cardiovascular disease by using endothelial cells induced by embryonic stem cells.%心血管疾病是目前引起死亡的主要原因之一,血管再生和细胞治疗为治愈心血管疾病带来了希望.胚胎干细胞作为内皮细胞和组织工程材料的来源,为治疗心血管疾病提供了广泛的应用前景.本文详细讲解胚胎干细胞向内皮细胞定向诱导分化的方法、信号通路及相关的转录调控因子,为研究定向诱导胚胎干细胞向血管内皮细胞分化提供系统的方法和理论指导,同时为利用胚胎干细胞来源的内皮细胞治疗心血管疾病提供了理论基础.

  5. Hemato-endothelial differentiation from lentiviral-transduced human embryonic stem cells retains durable reporter gene expression under the control of ubiquitin promoter

    OpenAIRE

    Jiang, Hua; Lin, Xiaolong; FENG, YOUJI; Xie, Yi; Han, Jinlan; Zhang, Yueping; Wang, Zack Z.; Chen, Tong

    2010-01-01

    Human embryonic stem (hES) cells are able to give rise to a variety of cell lineages under specific culture condition. An effective strategy for stable genetic modification in hES cells may provide a powerful tool for study of human embryogenesis and cell-based therapies. However, gene silences are documented in hES cells. In current study, we investigated whether genes controlled under ubiquitin promoter are expressed during hematopoietic-endothelial differentiation in hES cells. Undifferent...

  6. Concentration dependent survival and neural differentiation of murine embryonic stem cells cultured on polyethylene glycol dimethacrylate hydrogels possessing a continuous concentration gradient of n-cadherin derived peptide His-Ala-Val-Asp-Lle.

    Science.gov (United States)

    Lim, Hyun Ju; Mosley, Matthew C; Kurosu, Yuki; Smith Callahan, Laura A

    2016-12-01

    N-cadherin cell-cell signaling plays a key role in the structure and function of the nervous system. However, few studies have incorporated bioactive signaling from n-cadherin into tissue engineering matrices. The present study uses a continuous gradient approach in polyethylene glycol dimethacrylate hydrogels to identify concentration dependent effects of n-cadherin peptide, His-Ala-Val-Asp-Lle (HAVDI), on murine embryonic stem cell survival and neural differentiation. The n-cadherin peptide was found to affect the expression of pluripotency marker, alkaline phosphatase, in murine embryonic stem cells cultured on n-cadherin peptide containing hydrogels in a concentration dependent manner. Increasing n-cadherin peptide concentrations in the hydrogels elicited a biphasic response in neurite extension length and mRNA expression of neural differentiation marker, neuron-specific class III β-tubulin, in murine embryonic stem cells cultured on the hydrogels. High concentrations of n-cadherin peptide in the hydrogels were found to increase the expression of apoptotic marker, caspase 3/7, in murine embryonic stem cells compared to that of murine embryonic stem cell cultures on hydrogels containing lower concentrations of n-cadherin peptide. Increasing the n-cadherin peptide concentration in the hydrogels facilitated greater survival of murine embryonic stem cells exposed to increasing oxidative stress caused by hydrogen peroxide exposure. The combinatorial approach presented in this work demonstrates concentration dependent effects of n-cadherin signaling on mouse embryonic stem cell behavior, underscoring the need for the greater use of systematic approaches in tissue engineering matrix design in order to understand and optimize bioactive signaling in the matrix for tissue formation.

  7. Promoters of the murine embryonic beta-like globin genes Ey and betah1 do not compete for interaction with the beta-globin locus control region.

    Science.gov (United States)

    Hu, Xiao; Bulger, Michael; Roach, Julia N; Eszterhas, Susan K; Olivier, Emmanuel; Bouhassira, Eric E; Groudine, Mark T; Fiering, Steven

    2003-02-04

    Mammalian beta-globin loci contain multiple beta-like genes that are expressed at different times during development. The murine beta-globin locus contains two genes expressed during the embryo stage, Ey and betah1, and two genes expressed at both the fetal and postnatal stages, beta-major and beta-minor. Studies of transgenic human beta-like globin loci in mice have suggested that expression of one gene at the locus will suppress expression of other genes at the locus. To test this hypothesis we produced mouse lines with deletions of either the Ey or betah1 promoter in the endogenous murine beta-globin locus. Promoter deletion eliminated expression of the mutant gene but did not affect expression of the remaining embryonic gene or the fetal-adult beta-globin genes on the mutant allele. These results demonstrate a lack of competitive effects between individual mouse embryonic beta-globin gene promoters and other genes in the locus. The implication of these findings for models of beta-globin gene expression are discussed.

  8. Efficient production of platelets from mouse embryonic stem cells by enforced expression of Gata2 in late hemogenic endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Kawaguchi, Manami [Stem Cell Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506 (Japan); Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510 (Japan); Kitajima, Kenji [Stem Cell Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506 (Japan); Kanokoda, Mai [Stem Cell Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506 (Japan); Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510 (Japan); Suzuki, Hidenori [Division of Morphological and Biomolecular Research, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo, 113-8602 (Japan); Miyashita, Kazuya; Nakajima, Marino [Stem Cell Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506 (Japan); Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510 (Japan); Nuriya, Hideko [Core Technology and Research Center, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506 (Japan); Kasahara, Kohji [Laboratory of Biomembrane, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506 (Japan); Hara, Takahiko, E-mail: hara-tk@igakuken.or.jp [Stem Cell Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506 (Japan); Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510 (Japan)

    2016-06-03

    Platelets are essential for blood circulation and coagulation. Previous study indicated that overexpression of Gata2 in differentiated mouse embryonic stem cells (ESCs) resulted in robust induction of megakaryocytes (Mks). To evaluate platelet production capacity of the Gata2-induced ESC-derived Mks, we generated iGata2-ESC line carrying the doxycycline-inducible Gata2 expression cassette. When doxycycline was added to day 5 hemogenic endothelial cells in the in vitro differentiation culture of iGata2-ESCs, c-Kit{sup −}Tie2{sup −}CD41{sup +} Mks were predominantly generated. These iGata2-ESC-derived Mks efficiently produced CD41{sup +}CD42b{sup +}CD61{sup +} platelets and adhered to fibrinogen-coated glass coverslips in response to thrombin stimulation. Transmission electron microscopy analysis demonstrated that the iGata2-ESC-derived platelets were discoid-shaped with α-granules and an open canalicular system, but were larger than peripheral blood platelets in size. These results demonstrated that an enforced expression of Gata2 in late HECs of differentiated ESCs efficiently promotes megakaryopoiesis followed by platelet production. This study provides valuable information for ex vivo platelet production from human pluripotent stem cells in future. -- Highlights: •Megakaryocytes are efficiently induced by Gata2 from ESC-derived day 5 HECs. •Gata2-induced ESC-derived megakaryocytes are c-Kit{sup −}Tie2{sup −}CD41{sup +}. •Gata2-induced ESC-derived megakaryocytes produce larger discoid-shaped platelets. •Gata2-induced ESC-derived platelets bind fibrinogen upon thrombin stimulation.

  9. Isolation and transplantation of corneal endothelial cell-like cells derived from in-vitro-differentiated human embryonic stem cells.

    Science.gov (United States)

    Zhang, Kai; Pang, Kunpeng; Wu, Xinyi

    2014-06-15

    The maintenance of corneal dehydration and transparency depends on barrier and pump functions of corneal endothelial cells (CECs). The human CECs have no proliferation capacity in vivo and the ability to divide in vitro under culture conditions is dramatically limited. Thus, the acquisition of massive cells analogous to normal human CECs is extremely necessary whether from the perspective of cellular basic research or from clinical applications. Here we report the derivation of CEC-like cells from human embryonic stem cells (hESCs) through the periocular mesenchymal precursor (POMP) phase. Using the transwell coculture system of hESCs with differentiated human corneal stromal cells, we induced hESCs to differentiate into POMPs. Then, CEC-like cells were derived from POMPs with lens epithelial cell-conditioned medium. Within 1 week, CEC-like cells that expressed the corneal endothelium (CE) differentiation marker N-cadherin and transcription factors FoxC1 and Pitx2 were detectable. Fluorescence-activated cell sorting (FACS)-based isolation of the N-cadherin/vimentin dual-positive population enriches for CEC-like cells. The isolated CEC-like cells were labeled with carboxyfluorescein diacetate, succinimidyl ester (CFDA SE) and seeded onto posterior acellular porcine corneal matrix lamellae to construct the CEC-like cell sheets. Pump function parameters of the CEC-like cell sheets approximated those of human donor corneas. Importantly, when the CEC-like cell sheets were transplanted into the eyes of rabbit CE dysfunction models, the corneal transparency was restored gradually. In conclusion, CEC-like cells derived from hESCs displayed characteristics of native human CECs. This renewable source of human CECs offers massive cells for further studies of human CEC biological characteristics and potential applications of replacement therapies as substitution for donor CECs in the future.

  10. Endothelial protein C receptor function in murine and human breast cancer development.

    Directory of Open Access Journals (Sweden)

    Florence Schaffner

    Full Text Available Several markers identify cancer stem cell-like populations, but little is known about the functional roles of stem cell surface receptors in tumor progression. Here, we show that the endothelial protein C receptor (EPCR, a stem cell marker in hematopoietic, neuronal and epithelial cells, is crucial for breast cancer growth in the orthotopic microenvironment of the mammary gland. Mice with a hypomorphic allele of EPCR show reduced tumor growth in the PyMT-model of spontaneous breast cancer development and deletion of EPCR in established PyMT tumor cells significantly attenuates transplanted tumor take and growth. We find expansion of EPCR(+ cancer stem cell-like populations in aggressive, mammary fat pad-enhanced human triple negative breast cancer cells. In this model, EPCR-expressing cells have markedly increased mammosphere- and tumor-cell initiating activity compared to another stable progenitor-like subpopulation present at comparable frequency. We show that receptor blocking antibodies to EPCR specifically attenuate in vivo tumor growth initiated by either EPCR(+ cells or the heterogenous mixture of EPCR(+ and EPCR(- cells. Furthermore, we have identified tumor associated macrophages as a major source for recognized ligands of EPCR, suggesting a novel mechanism by which cancer stem cell-like populations are regulated by innate immune cells in the tumor microenvironment.

  11. An abbreviated protocol for multilineage neural differentiation of murine embryonic stem cells and its perturbation by methyl mercury.

    NARCIS (Netherlands)

    Theunissen, P.T.; Schulpen, S.; van Dartel, D.A.M.; Hermsen, S.A.B.; van Schooten, F.J.; Piersma, A.H.

    2010-01-01

    Alternative assays are highly desirable to reduce the extensive experimental animal use in developmental toxicity testing. In the present study, we developed an improved test system for assessing neurodevelopmental toxicity using differentiating embryonic stem cells. We advanced previously establish

  12. An abbreviated protocol for multilineage neural differentiation of murine embryonic stem cells and its perturbation by methyl mercury.

    NARCIS (Netherlands)

    Theunissen, P.T.; Schulpen, S.; van Dartel, D.A.M.; Hermsen, S.A.B.; van Schooten, F.J.; Piersma, A.H.

    2010-01-01

    Alternative assays are highly desirable to reduce the extensive experimental animal use in developmental toxicity testing. In the present study, we developed an improved test system for assessing neurodevelopmental toxicity using differentiating embryonic stem cells. We advanced previously establish

  13. VEGF is deposited in the subepithelial matrix at the leading edge of branching airways and stimulates neovascularization in the murine embryonic lung.

    Science.gov (United States)

    Healy, A M; Morgenthau, L; Zhu, X; Farber, H W; Cardoso, W V

    2000-11-01

    We used whole lung cultures as a model to study blood vessel formation in vitro and to examine the role that epithelial-mesenchymal interactions play during embryonic pulmonary vascular development. Mouse lungs were isolated at embryonic day 11.5 (E11.5) and cultured for up to 4 days prior to blood vessel analysis. Platelet endothelial cell adhesion molecule-1 (PECAM/CD31) and thrombomodulin (TM/CD141) immunolocalization demonstrate that vascular development occurs in lung cultures. The vascular structures identified in lung cultures first appear as a loosely associated plexus of capillary-like structures that with time surround the airways. To investigate the potential role of vascular endothelial cell growth factor (VEGF) during pulmonary neovascularization, we immunolocalized VEGF in embryonic lungs. Our data demonstrate that VEGF is uniformly present in the airway epithelium and the subepithelial matrix of E11.5 lungs. At later time points, E13.5 and E15.5, VEGF is no longer detected in the proximal airways, but is restricted to the branching tips of airways in the distal lung. RT-PCR analysis reveals that VEGF(164) is the predominant isoform expressed in lung cultures. Grafting heparin-bound VEGF(164) beads onto lung explants locally stimulates a marked neovascular response within 48 hr in culture. Semi-quantitative RT-PCR reveals an 18% increase in PECAM mRNA in VEGF(164)-treated whole lung cultures as compared with untreated cultures. The restricted temporal and spatial expression of VEGF suggests that matrix-associated VEGF links airway branching with blood vessel formation by stimulating neovascularization at the leading edge of branching airways.

  14. Impaired function of bone marrow-derived endothelial progenitor cells in murine liver fibrosis.

    Science.gov (United States)

    Shirakura, Katsuya; Masuda, Haruchika; Kwon, Sang-Mo; Obi, Syotaro; Ito, Rie; Shizuno, Tomoko; Kurihara, Yusuke; Mine, Tetsuya; Asahara, Takayuki

    2011-01-01

    Liver fibrosis (LF) caused by chronic liver damage has been considered as an irreversible disease. As alternative therapy for liver transplantation, there are high expectations for regenerative medicine of the liver. Bone marrow (BM)- or peripheral blood-derived stem cells, including endothelial progenitor cells (EPCs), have recently been used to treat liver cirrhosis. We investigated the biology of BM-derived EPC in a mouse model of LF. C57BL/6J mice were subcutaneously injected with carbon tetrachloride (CCl(4)) every 3 days for 90 days. Sacrificed 2 days after final injection, whole blood (WB) was collected for isolation of mononuclear cells (MNCs) and biochemical examination. Assessments of EPC in the peripheral blood and BM were performed by flow cytometry and EPC colony-forming assay, respectively, using purified MNCs and BM c-KIT(+), Sca-1(+), and Lin(-) (KSL) cells. Liver tissues underwent histological analysis with hematoxylin/eosin/Azan staining, and spleens were excised and weighed. CCl(4)-treated mice exhibited histologically bridging fibrosis, pseudolobular formation, and splenomegaly, indicating successful induction of LF. The frequency of definitive EPC-colony-forming-units (CFU) as well as total EPC-CFU at the equivalent cell number of 500 BM-KSL cells decreased significantly (p changes in primitive EPC-CFU occurred in LF mice. The frequency of WB-MNCs of definitive EPC-CFU decreased significantly (p < 0.01) in LF mice compared with control mice. Together, these findings indicated the existence of impaired EPC function and differentiation in BM-derived EPCs in LF mice and might be related to clinical LF.

  15. Targeting formyl peptide receptor 2 reduces leukocyte-endothelial interactions in a murine model of stroke.

    Science.gov (United States)

    Smith, Helen K; Gil, Cristiane Damas; Oliani, Sonia M; Gavins, Felicity N E

    2015-05-01

    Ischemia/reperfusion (I/R) injury following stroke can worsen patient outcome through excess inflammation. This study investigated the pharmacologic potential of targeting an endogenous anti-inflammatory circuit via formyl peptide receptor (FPR) 2/lipoxin receptor (ALX) (Fpr2/3 in mouse) in global cerebral I/R. Mice (C57BL/6 and Fpr2/3(-/-)) were subjected to bilateral common carotid artery occlusion, followed by reperfusion and treatment with FPR agonists: AnxA1Ac2-26 [Annexin A1 mimetic peptide (Ac-AMVSEFLKQAWFIENEEQEYVQTVK), 2.5 μg/kg] and 15-epimer-lipoxin A4 (15-epi-LXA4; FPR2/ALX specific, 12.5 and 100 ng/kg). Leukocyte-endothelial (L-E) interactions in the cerebral microvasculature were then quantified in vivo using intravital fluorescence microscopy. 15-epi-LXA4 administration at the start of reperfusion reduced L-E interactions after 40 min (which was sustained at 2 h with high-dose 15-epi-LXA4) to levels seen in sham-operated animals. AnxA1Ac2-26 treatment decreased leukocyte adhesion at 40 min and all L-E interactions at 2 h (up to 95%). Combined treatment with AnxA1Ac2-26 plus FPR antagonists t-Boc-FLFLF (250 ng/kg) or WRW4 (FPR2/ALX selective, 1.4 μg/kg) abrogated the effects of AnxA1Ac2-26 fully at 40 min. Antagonists were less effective at 2 h, which we demonstrate is likely because of their impact on early L-E interactions. Our findings indicate that FPR2/ALX activity elicits considerable control over vascular inflammatory responses during cerebral I/R and, therefore, provide evidence that targeting FPR2/ALX may be beneficial for patients who suffered from stroke. © FASEB.

  16. Nuclear Magnetic Resonance Detects Phosphoinositide 3-Kinase/Akt-Independent Traits Common to Pluripotent Murine Embryonic Stem Cells and Their Malignant Counterparts

    Directory of Open Access Journals (Sweden)

    Hanna M. Romanska

    2009-12-01

    Full Text Available Pluripotent embryonic stem (ES cells, a potential source of somatic precursors for cell therapies, cause tumors after transplantation. Studies of mammalian carcinogenesis using nuclear magnetic resonance (NMR spectroscopy have revealed changes in the choline region, particularly increased phosphocholine (PCho content. High PCho levels in murine ES (mES cells have recently been attributed to cell pluripotency. The phosphoinositide 3-kinase (PI3K/Akt pathway has been implicated in tumor-like properties of mES cells. This study aimed to examine a potential link between the metabolic profile associated with choline metabolism of pluripotent mES cells and PI3K/Akt signaling. We used mES (ES-D3 and murine embryonal carcinoma cells (EC-F9 and compared the metabolic profiles of 1 pluripotent mES (ESD0, 2 differentiated mES (ESD14, and 3 pluripotent F9 cells. Involvement of the PI3K/Akt pathway was assessed using LY294002, a selective PI3K inhibitor. Metabolic profiles were characterized in the extracted polar fraction by 1H NMR spectroscopy. Similarities were found between the levels of choline phospholipid metabolites (PCho/total choline and PCho/glycerophosphocholine [GPCho] in ESD0 and F9 cell spectra and a greater-than five-fold decrease of the PCho/GPCho ratio associated with mES cell differentiation. LY294002 caused no significant change in relative PCho levels but led to a greater-than two-fold increase in PCho/GPCho ratios. These results suggest that the PCho/GPCho ratio is a metabolic trait shared by pluripotent and malignant cells and that PI3K does not underlie its development. It is likely that the signature identified here in a mouse model may be relevant for safe therapeutic applications of human ES cells.

  17. Desmin phosphorylation by Cdk1 is required for efficient separation of desmin intermediate filaments in mitosis and detected in murine embryonic/newborn muscle and human rhabdomyosarcoma tissues.

    Science.gov (United States)

    Makihara, Hiroyuki; Inaba, Hironori; Enomoto, Atsushi; Tanaka, Hiroki; Tomono, Yasuko; Ushida, Kaori; Goto, Mitsuo; Kurita, Kenichi; Nishida, Yoshihiro; Kasahara, Kousuke; Goto, Hidemasa; Inagaki, Masaki

    2016-09-23

    Desmin is a type III intermediate filament (IF) component protein expressed specifically in muscular cells. Desmin is phosphorylated by Aurora-B and Rho-kinase specifically at the cleavage furrow from anaphase to telophase. The disturbance of this phosphorylation results in the formation of unusual long bridge-like IF structures (IF-bridge) between two post-mitotic (daughter) cells. Here, we report that desmin also serves as an excellent substrate for the other type of mitotic kinase, Cdk1. Desmin phosphorylation by Cdk1 loses its ability to form IFs in vitro. We have identified Ser6, Ser27, and Ser31 on murine desmin as phosphorylation sites for Cdk1. Using a site- and phosphorylation-state-specific antibody for Ser31 on desmin, we have demonstrated that Cdk1 phosphorylates desmin in entire cytoplasm from prometaphase to metaphase. Desmin mutations at Cdk1 sites exhibit IF-bridge phenotype, the frequency of which is significantly increased by the addition of Aurora-B and Rho-kinase site mutations to Cdk1 site mutations. In addition, Cdk1-induced desmin phosphorylation is detected in mitotic muscular cells of murine embryonic/newborn muscles and human rhabdomyosarcoma specimens. Therefore, Cdk1-induced desmin phosphorylation is required for efficient separation of desmin-IFs and generally detected in muscular mitotic cells in vivo.

  18. Phosphoinositide 3-kinase alpha-dependent regulation of branching morphogenesis in murine embryonic lung: evidence for a role in determining morphogenic properties of FGF7.

    Science.gov (United States)

    Carter, Edward; Miron-Buchacra, Gabriela; Goldoni, Silvia; Danahay, Henry; Westwick, John; Watson, Malcolm L; Tosh, David; Ward, Stephen G

    2014-01-01

    Branching morphogenesis is a critical step in the development of many epithelial organs. The phosphoinositide-3-kinase (PI3K) pathway has been identified as a central component of this process but the precise role has not been fully established. Herein we sought to determine the role of PI3K in murine lung branching using a series of pharmacological inhibitors directed at this pathway. The pan-class I PI3K inhibitor ZSTK474 greatly enhanced the branching potential of whole murine lung explants as measured by an increase in the number of terminal branches compared with controls over 48 hours. This enhancement of branching was also observed following inhibition of the downstream signalling components of PI3K, Akt and mTOR. Isoform selective inhibitors of PI3K identified that the alpha isoform of PI3K is a key driver in branching morphogenesis. To determine if the effect of PI3K inhibition on branching was specific to the lung epithelium or secondary to an effect on the mesenchyme we assessed the impact of PI3K inhibition in cultures of mesenchyme-free lung epithelium. Isolated lung epithelium cultured with FGF7 formed large cyst-like structures, whereas co-culture with FGF7 and ZSTK474 induced the formation of defined branches with an intact lumen. Together these data suggest a novel role for PI3K in the branching program of the murine embryonic lung contradictory to that reported in other branching organs. Our observations also point towards PI3K acting as a morphogenic switch for FGF7 signalling.

  19. Hemato-endothelial differentiation from lentiviral-transduced human embryonic stem cells retains durable reporter gene expression under the control of ubiquitin promoter.

    Science.gov (United States)

    Jiang, Hua; Lin, Xiaolong; Feng, Youji; Xie, Yi; Han, Jinlan; Zhang, Yueping; Wang, Zack Z; Chen, Tong

    2010-01-01

    Human embryonic stem (hES) cells are able to give rise to a variety of cell lineages under specific culture condition. An effective strategy for stable genetic modification in hES cells may provide a powerful tool for study of human embryogenesis and cell-based therapies. However, gene silences are documented in hES cells. In current study, we investigated whether genes controlled under ubiquitin promoter are expressed during hematopoietic-endothelial differentiation in hES cells. Undifferentiated hES cells (H1) were transduced by lentivirus encoding green fluorescent protein (GFP) gene under ubiquitin promoter. GFP-expressing hES cells (GFP-H1) were established after several rounds of mechanical selection under fluorescence microscope. GFP gene was stably expressed in hES cells throughout prolonged (> 50 passages) cultivation, and in differentiated embryo body (EB) and teratoma. Hematopoietic and endothelial markers, including KDR (VEGFR2), CD34, CD31, Tie-2, GATA-1 and GATA-2, were expressed at similar levels during hES cell differentiation in parent hES cells and GFP-H1 hES cells. CD34(+) cells isolated from GFP-H1 hES cells were capable to generate hematopoietic colony-forming cells and tubular structure-forming cells. Differentiated GFP-EB formed vasculature structures in a semi-solid sprouting EB model. These results indicated that a transgene under ubiquitin promoter in lentiviral transduced hES cells retained its expression in undifferentiated hES cells and in hES-derived hematopoietic and endothelial cells. With the view of embryonic mesodermal developing events in humans, genetic modification of hES cells by lentiviral vectors provides a powerful tool for study of hematopoiesis and vasculogenesis.

  20. 人胚胎干细胞向内皮细胞的分化诱导%Induced differentiation of human embryonic stem cells into endothelial cells

    Institute of Scientific and Technical Information of China (English)

    时洋; 沈军生; 毋涛涛; 李小飞

    2016-01-01

    BACKGROUND:Human embryonic stem cels exhibit self-renewal and multi-differentiation potential, and can differentiate into endothelial cels under certaininduction conditions. OBJECTIVE:To explore induced conditions of the human embryonic stem cels differentiating into endothelial cels and to investigate the effect of vascular endothelial growth factors on theendothelial differentiation of human embryonic stem cels. METHODS:After resuscitation,passage40 human embryonic stem cel lines H9 weresubjected to suspension culture to prepare embryos, and after 5-day culture,these cels werecultured in attachment medium to differentiate into embryoid bodies,folowed by induction with50 µg/L vascular endothelial growth factors. Passage 2 and 15 embryonic stem cels after induced differentiation weretaken for Dil-Ac-LDL uptake test and immunohistochemical staining, respectively. RESULTS AND CONCLUSION:After 1-day culture, cord-like or polygonal monolayer cels around embryoid bodies showed bud-like andradialgrowth witharelative rapid speed merging into surrounding colonies; at 2-3 days, the number of suspension cels increased further, but the smal-round cels in the center began to die; at 5 days, embryoid bodies started to passage, and aggregated cels exhibited typical paving stone-like appearance. Moreover, some human embryonic cels after induced differentiation could actively takeupfluorescent labeled LDL,andred fluorescent particlesappeared.Additionaly, passage 15 embryonic stem cels after induced differentiation could express CD31 and FLK-1.These findings suggest that human embryonic stem cels induced by vascular endothelial growth factors can differentiate into endothelial cels.%背景:人胚胎干细胞是一类特殊的细胞,具有自我更新及多向分化潜力,在一定诱导条件下能够分化为内皮细胞。  目的:探讨人胚胎干细胞向内皮细胞分化的条件,研究血管内皮生长因子诱导人胚胎干细胞诱导分化为内皮细

  1. Delivery of differentiation factors by mesoporous silica particles assists advanced differentiation of transplanted murine embryonic stem cells

    DEFF Research Database (Denmark)

    Garcia-Bennett, Alfonso E; Kozhevnikova, Mariya; König, Niclas;

    2013-01-01

    Stem cell transplantation holds great hope for the replacement of damaged cells in the nervous system. However, poor long-term survival after transplantation and insufficiently robust differentiation of stem cells into specialized cell types in vivo remain major obstacles for clinical application...... neurotrophic factor and glial cell line-derived neurotrophic factor, respectively, with these particles enabled not only robust functional differentiation of motor neurons from transplanted embryonic stem cells but also their long-term survival in vivo. We propose that the delivery of growth factors...... by mesoporous nanoparticles is a potentially versatile and widely applicable strategy for efficient differentiation and functional integration of stem cell derivatives upon transplantation....

  2. Icariin promotes expression of PGC-1α, PPARα, and NRF-1 during cardiomyocyte differentiation of murine embryonic stem cells in vitro

    Institute of Scientific and Technical Information of China (English)

    Ling DING; Xing-guang LIANG; Dan-yan ZHU; Yi-jia LOU

    2007-01-01

    Aim: To investigate the effect of icariin on the expression of peroxisome proliferator-activated receptor γ coactivator- 1 alpha (PGC- 1 α), peroxisome proliferator-activated receptor alpha (PPARα), and nuclear respiratory factor 1 (NRF-1) on cardiomyocyte differentiation of murine embryonic stem (ES) cells in vitro.Methods: The cardiomyocytes derived from murine ES cells were verified by immunocytochemistry using confocal laser scanning microscopy. Cardiacspecific sarcomeric proteins (ie α-actinin, troponin T) were evaluated when embryoid bodies (EB) were treated with icariin or retinoid acid. The expression of PGC-1α, PPARα, and NRF-1 were analyzed using both semiquantitative RT-PCR and Western blotting in cardiomyocyte differentiation. The phosphorylation of the p38 mitogen-activated protein kinase (MAPK) was studied in the differentiation process, and its specific inhibitor SB203580 was employed to confirm the function of the p38 MAPK on icariin-induced cardiac differentiation. Results:The application of icariin significantly induced the cardiomyocyte differentiation of EB as indicated by the promoted expression of α-actinin and troponin T. The expression of PGC-1α, PPARα and NRF-1 increased coincidently in early differentiation and the increase was dose-dependently upregulated by icariin treatment.The phosphorylation of the p38 MAPK peaked on d 6 and decreased after d 8, andthe activation was further enhanced and prolonged when the EB were subjected to icariin, which was concurrent with the elevation of PGC-1α, PPARα, and NRF-1. Moreover, the inhibition of the p38 MAPK pathway by SB203580 efficiently abolished icariin-stimulated cardiomyocyte differentiation and resulted in the capture of the upregulation of PGC-lα, PPARα, and NRF-1. Conclusion: Taken together, icariin promoted the expression of PGC-1 α, PPARα, and NRF-1 during cardiomyocyte differentiation ofmurine ES cells in vitro and the effect was partly responsible for the activation of

  3. Transport of organic anions and cations in murine embryonic kidney development and in serially-reaggregated engineered kidneys.

    Science.gov (United States)

    Lawrence, Melanie L; Chang, C-Hong; Davies, Jamie A

    2015-03-13

    Recent advances in renal tissue engineering have shown that dissociated, early renogenic tissue from the developing embryo can self-assemble into morphologically accurate kidney-like organs arranged around a central collecting duct tree. In order for such self-assembled kidneys to be useful therapeutically or as models for drug screening, it is necessary to demonstrate that they are functional. One of the main functional characteristics of mature kidneys is transport of organic anions and cations into and out of the proximal tubule. Here, we show that the transport function of embryonic kidneys allowed to develop in culture follows a developmental time-course that is comparable to embryonic kidney development in vivo. We also demonstrate that serially-reaggregated engineered kidneys can transport organic anions and cations through specific uptake and efflux channels. These results support the physiological relevance of kidneys grown in culture, a commonly used model for kidney development and research, and suggest that serially-reaggregated kidneys self-assembled from separated cells have some functional characteristics of intact kidneys.

  4. Murine Wee1 Plays a Critical Role in Cell Cycle Regulation and Pre-Implantation Stages of Embryonic Development

    Directory of Open Access Journals (Sweden)

    Yohei Tominaga, Cuiling Li, Rui-Hong Wang, Chu-Xia Deng

    2006-01-01

    Full Text Available Wee1 kinase regulates the G2/M cell cycle checkpoint by phosphorylating and inactivating the mitotic cyclin-dependent kinase 1 (Cdk1. Loss of Wee1 in many systems, including yeast and drosophila, leads to premature mitotic entry. However, the developmental role of Wee1 in mammals remains unclear. In this study, we established Wee1 knockout mice by gene targeting. We found that Wee-/- embryos were defective in the G2/M cell cycle checkpoint induced by γ-irradiation and died of apoptosis before embryonic (E day 3.5. To study the function of Wee1 further, we have developed MEF cells in which Wee1 is disrupted by a tamoxifen inducible Cre-LoxP approach. We found that acute deletion of Wee1 resulted in profound growth defects and cell death. Wee1 deficient cells displayed chromosome aneuploidy and DNA damage as revealed by γ-H2AX foci formation and Chk2 activation. Further studies revealed a conserved mechanism of Wee1 in regulating mitotic entry and the G2/M checkpoint compared with other lower organisms. These data provide in vivo evidence that mammalian Wee1 plays a critical role in maintaining genome integrity and is essential for embryonic survival at the pre-implantation stage of mouse development.

  5. Expression of conserved signalling pathway genes during spontaneous vascular differentiation of R1 embryonic stem cells and in Py-4-1 endothelial cells

    Indian Academy of Sciences (India)

    Kavitha Siva; K Gokul; Maneesha S Inamdar

    2007-12-01

    Embryonic stem (ES) cells are an invaluable model for identifying subtle phenotypes as well as severe outcomes of perturbing gene function that may otherwise result in lethality. However, though ES cells of different origins are regarded as equally pluripotent, their in vitro differentiation potential varies, suggesting that their response to developmental signals is different. The R1 cell line is widely used for gene manipulation due to its good growth characteristics and highly efficient germline transmission. Hence, we analysed the expression of Notch, Wnt and Sonic Hedgehog (Shh) pathway genes during differentiation of R1 cells into early vascular lineages. Notch-, Wnt-and Shh-mediated signalling is important during embryonic development. Regulation of gene expression through these signalling molecules is a frequently used theme, resulting in context-dependent outcomes during development. Perturbing these pathways can result in severe and possibly lethal developmental phenotypes often due to primary cardiovascular defects. We report that during early spontaneous differentiation of R1 cells, Notch-1 and the Wnt target Brachyury are active whereas the Shh receptor is not detected. This expression pattern is similar to that seen in a mouse endothelial cell line. This temporal study of expression of genes representative of all three pathways in ES cell differentiation will aid in further analysis of cell signalling during vascular development.

  6. Implantation of mouse embryonic stem cell-derived cardiac progenitor cells preserves function of infarcted murine hearts.

    Directory of Open Access Journals (Sweden)

    Nicolas Christoforou

    Full Text Available Stem cell transplantation holds great promise for the treatment of myocardial infarction injury. We recently described the embryonic stem cell-derived cardiac progenitor cells (CPCs capable of differentiating into cardiomyocytes, vascular endothelium, and smooth muscle. In this study, we hypothesized that transplanted CPCs will preserve function of the infarcted heart by participating in both muscle replacement and neovascularization. Differentiated CPCs formed functional electromechanical junctions with cardiomyocytes in vitro and conducted action potentials over cm-scale distances. When transplanted into infarcted mouse hearts, CPCs engrafted long-term in the infarct zone and surrounding myocardium without causing teratomas or arrhythmias. The grafted cells differentiated into cross-striated cardiomyocytes forming gap junctions with the host cells, while also contributing to neovascularization. Serial echocardiography and pressure-volume catheterization demonstrated attenuated ventricular dilatation and preserved left ventricular fractional shortening, systolic and diastolic function. Our results demonstrate that CPCs can engraft, differentiate, and preserve the functional output of the infarcted heart.

  7. Impurity of stem cell graft by murine embryonic fibroblasts – implications for cell-based therapy of the central nervous system

    Directory of Open Access Journals (Sweden)

    Marek eMolcanyi

    2014-09-01

    Full Text Available Stem cells have been demonstrated to possess a therapeutic potential in experimental models of various central nervous system disorders, including stroke. The types of implanted cells appear to play a crucial role. Previously, groups of the stem cell network NRW implemented a feeder-based cell line within the scope of their projects, examining the implantation of stem cells after ischemic stroke and traumatic brain injury. Retrospective evaluation indicated the presence of spindle-shaped cells in several grafts implanted in injured animals, which indicated potential contamination by co-cultured feeder cells (murine embryonic fibroblasts – MEFs. Because feeder-based cell lines have been previously exposed to a justified criticism with regard to contamination by animal glycans, we aimed to evaluate the effects of stem cell/MEF co-transplantation. MEFs accounted for 5.33% ± 2.81 of all cells in the primary FACS-evaluated co-culture. Depending on the culture conditions and subsequent purification procedure, the MEF-fraction ranged from 0.9 to 9.9% of the cell suspensions in vitro. MEF survival and related formation of extracellular substances in vivo were observed after implantation into the uninjured rat brain. Impurity of the stem cell graft by MEFs interferes with translational strategies, which represents a threat to the potential recipient and may affect the graft microenvironment. The implications of these findings are critically discussed.

  8. Lipopolysaccharide-induced murine embryonic resorption involves changes in endocannabinoid profiling and alters progesterone secretion and inflammatory response by a CB1-mediated fashion.

    Science.gov (United States)

    Wolfson, Manuel L; Correa, Fernando; Leishman, Emma; Vercelli, Claudia; Cymeryng, Cora; Blanco, Julieta; Bradshaw, Heather B; Franchi, Ana María

    2015-08-15

    Genital tract infections are a common complication of human pregnancy that can result in miscarriage. We have previously shown that a lipopolysaccharide (LPS) induces embryonic resorption in a murine model of inflammatory miscarriage. This is accompanied by a dramatic decrease in systemic progesterone levels associated with a robust pro-inflammatory response that results in embryo resorption. Here, we tested the hypothesis that the endogenous cannabinoid system (eCS), through cannabinoid receptor 1 (CB1), plays a role in regulating progesterone levels and, therefore, the pro-inflammatory response. We show that LPS treatment in pregnant mice causes significant changes in the eCS ligands, which are reversed by progesterone treatment. We further show the CB1-KO mice maintain higher plasma progesterone levels after LPS treatment, which is associated with a feebler uterine inflammatory response and a significant drop in embryo resorption. These data suggest that manipulation of CB1 receptors and/or ligands is a potential therapeutic avenue to decrease infection-induced miscarriage.

  9. An effort to test the embryotoxicity of benzene, toluene, xylene, and formaldehyde to murine embryonic stem cells using airborne exposure technique.

    Science.gov (United States)

    Shen, Shuijie; Yuan, Lingmin; Zeng, Su

    2009-10-01

    Benzene, toluene, xylene, and formaldehyde are well-known indoor air pollutants, especially after house decoration. They are also common pollutants in the working places of the plastic industry, chemical industry, and leather industry. It has been reported that these pollutants cause people to be irritated, sick, experience a headache, and be dizzy. They also have the potential to induce asthma, aplastic anemia, and leukemia, even cause abortion or fetus malformation in humans. In this study, the airborne toxicity of benzene, toluene, xylene, and formaldehyde to murine embryonic stem cells (mES cells) were tested using airborne exposure technique to evaluate the mES cell airborne exposure model on embryotoxicity prediction. Briefly, mES cells were cultured on Transwell inserts and were exposed to an airborne surrounding of test chemicals in a chamber for 1 h at 37 degrees C. Cytotoxicity was determined using the MTT assay after further culture for 18 h at 37 degrees C in normal medium. The airborne IC(50) (50% inhibition concentration) of benzene, toluene, xylene, and formaldehyde derived from the fitted dose-response curves were 17,400 +/- 1290, 16,000 +/- 250, 4680 +/- 500, and 620 +/- 310 ppm, respectively. Formaldehyde was found to be the compound most toxic to mES cells compared to benzene homologues. The toxicity data had good correlation with the in vivo data. The results showed that the mES airborne exposure model may be used to predict embryotoxicity of volatile organic compounds.

  10. Limited Gene Expression Variation in Human Embryonic Stem Cell and Induced Pluripotent Stem Cell Derived Endothelial Cells

    OpenAIRE

    2013-01-01

    Recent evidence suggests human embryonic stem cell (hESC) and induced pluripotent stem (iPS) cell lines have differences in their epigenetic marks and transcriptomes, yet the impact of these differences on subsequent terminally differentiated cells is less well understood. Comparison of purified, homogeneous populations of somatic cells derived from multiple independent human iPS and ES lines will be required to address this critical question. Here, we report a differentiation protocol based ...

  11. Murine junctional adhesion molecules JAM-B and JAM-C mediate endothelial and stellate cell interactions during hepatic fibrosis.

    Science.gov (United States)

    Hintermann, Edith; Bayer, Monika; Ehser, Janine; Aurrand-Lions, Michel; Pfeilschifter, Josef M; Imhof, Beat A; Christen, Urs

    2016-07-03

    Classical junctional adhesion molecules JAM-A, JAM-B and JAM-C influence vascular permeability, cell polarity as well as leukocyte recruitment and immigration into inflamed tissue. As the vasculature becomes remodelled in chronically injured, fibrotic livers we aimed to determine distribution and role of junctional adhesion molecules during this pathological process. Therefore, livers of naïve or carbon tetrachloride-treated mice were analyzed by immunohistochemistry to localize all 3 classical junctional adhesion molecules. Hepatic stellate cells and endothelial cells were isolated and subjected to immunocytochemistry and flow cytometry to determine localization and functionality of JAM-B and JAM-C. Cells were further used to perform contractility and migration assays and to study endothelial tubulogenesis and pericytic coverage by hepatic stellate cells. We found that in healthy tissue, JAM-A was ubiquitously expressed whereas JAM-B and JAM-C were restricted to the vasculature. During fibrosis, JAM-B and JAM-C levels increased in endothelial cells and JAM-C was de novo generated in myofibroblastic hepatic stellate cells. Soluble JAM-C blocked contractility but increased motility in hepatic stellate cells. Furthermore, soluble JAM-C reduced endothelial tubulogenesis and endothelial cell/stellate cell interaction. Thus, during liver fibrogenesis, JAM-B and JAM-C expression increase on the vascular endothelium. More importantly, JAM-C appears on myofibroblastic hepatic stellate cells linking them as pericytes to JAM-B positive endothelial cells. This JAM-B/JAM-C mediated interaction between endothelial cells and stellate cells stabilizes vessel walls and may control the sinusoidal diameter. Increased hepatic stellate cell contraction mediated by JAM-C/JAM-C interaction may cause intrahepatic vasoconstriction, which is a major complication in liver cirrhosis.

  12. Fluorescence-Activated Cell Sorting of EGFP-Labeled Neural Crest Cells From Murine Embryonic Craniofacial Tissue

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    Saurabh Singh

    2005-01-01

    Full Text Available During the early stages of embryogenesis, pluripotent neural crest cells (NCC are known to migrate from the neural folds to populate multiple target sites in the embryo where they differentiate into various derivatives, including cartilage, bone, connective tissue, melanocytes, glia, and neurons of the peripheral nervous system. The ability to obtain pure NCC populations is essential to enable molecular analyses of neural crest induction, migration, and/or differentiation. Crossing Wnt1-Cre and Z/EG transgenic mouse lines resulted in offspring in which the Wnt1-Cre transgene activated permanent EGFP expression only in NCC. The present report demonstrates a flow cytometric method to sort and isolate populations of EGFP-labeled NCC. The identity of the sorted neural crest cells was confirmed by assaying expression of known marker genes by TaqMan Quantitative Real-Time Polymerase Chain Reaction (QRT-PCR. The molecular strategy described in this report provides a means to extract intact RNA from a pure population of NCC thus enabling analysis of gene expression in a defined population of embryonic precursor cells critical to development.

  13. Leucine-rich repeat kinase 2 modulates retinoic acid-induced neuronal differentiation of murine embryonic stem cells.

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    Cathrin Schulz

    Full Text Available BACKGROUND: Dominant mutations in the leucine-rich repeat kinase 2 (LRRK2 gene are the most prevalent cause of Parkinson's disease, however, little is known about the biological function of LRRK2 protein. LRRK2 is expressed in neural precursor cells suggesting a role in neurodevelopment. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, differential gene expression profiling revealed a faster silencing of pluripotency-associated genes, like Nanog, Oct4, and Lin28, during retinoic acid-induced neuronal differentiation of LRRK2-deficient mouse embryonic stem cells compared to wildtype cultures. By contrast, expression of neurotransmitter receptors and neurotransmitter release was increased in LRRK2+/- cultures indicating that LRRK2 promotes neuronal differentiation. Consistently, the number of neural progenitor cells was higher in the hippocampal dentate gyrus of adult LRRK2-deficient mice. Alterations in phosphorylation of the putative LRRK2 substrates, translation initiation factor 4E binding protein 1 and moesin, do not appear to be involved in altered differentiation, rather there is indirect evidence that a regulatory signaling network comprising retinoic acid receptors, let-7 miRNA and downstream target genes/mRNAs may be affected in LRRK2-deficient stem cells in culture. CONCLUSION/SIGNIFICANCE: Parkinson's disease-linked LRRK2 mutations that associated with enhanced kinase activity may affect retinoic acid receptor signaling during neurodevelopment and/or neuronal maintenance as has been shown in other mouse models of chronic neurodegenerative diseases.

  14. A Modified Murine Embryonic Stem Cell Test for Evaluating the Teratogenic Effects of Drugs on Early Embryogenesis.

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    Yu, Ruoxing; Miyamura, Norio; Okamoto-Uchida, Yoshimi; Arima, Norie; Ishigami-Yuasa, Mari; Kagechika, Hiroyuki; Nishina, Hiroshi

    2015-01-01

    Mammalian fetal development is easily disrupted by exogenous agents, making it essential to test new drug candidates for embryotoxicity and teratogenicity. To standardize the testing of drugs that might be used to treat pregnant women, the U.S. Food and Drug Administration (FDA) formulated special grade categories, labeled A, B, C, D and X, that define the level of risk associated with the use of a specific drug during pregnancy. Drugs in categories (Cat.) D and X are those with embryotoxic and/or teratogenic effects on humans and animals. However, which stages of pregnancy are affected by these agents and their molecular mechanisms are unknown. We describe here an embryonic stem cell test (EST) that classifies FDA pregnancy Cat.D and Cat.X drugs into 4 classes based on their differing effects on primitive streak formation. We show that ~84% of Cat.D and Cat.X drugs target this period of embryogenesis. Our results demonstrate that our modified EST can identify how a drug affects early embryogenesis, when it acts, and its molecular mechanism. Our test may thus be a useful addition to the drug safety testing armamentarium.

  15. A Modified Murine Embryonic Stem Cell Test for Evaluating the Teratogenic Effects of Drugs on Early Embryogenesis.

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    Ruoxing Yu

    Full Text Available Mammalian fetal development is easily disrupted by exogenous agents, making it essential to test new drug candidates for embryotoxicity and teratogenicity. To standardize the testing of drugs that might be used to treat pregnant women, the U.S. Food and Drug Administration (FDA formulated special grade categories, labeled A, B, C, D and X, that define the level of risk associated with the use of a specific drug during pregnancy. Drugs in categories (Cat. D and X are those with embryotoxic and/or teratogenic effects on humans and animals. However, which stages of pregnancy are affected by these agents and their molecular mechanisms are unknown. We describe here an embryonic stem cell test (EST that classifies FDA pregnancy Cat.D and Cat.X drugs into 4 classes based on their differing effects on primitive streak formation. We show that ~84% of Cat.D and Cat.X drugs target this period of embryogenesis. Our results demonstrate that our modified EST can identify how a drug affects early embryogenesis, when it acts, and its molecular mechanism. Our test may thus be a useful addition to the drug safety testing armamentarium.

  16. Embryonic stem cells derived from in vivo or in vitro-generated murine blastocysts display similar transcriptome and differentiation potential.

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    Rhodel K Simbulan

    Full Text Available The use of assisted reproductive technologies (ART such as in vitro fertilization (IVF has resulted in the birth of more than 5 million children. While children conceived by these technologies are generally healthy, there is conflicting evidence suggesting an increase in adult-onset complications like glucose intolerance and high blood pressure in IVF children. Animal models indicate similar potential risks. It remains unclear what molecular mechanisms may be operating during in vitro culture to predispose the embryo to these diseases. One of the limitations faced by investigators is the paucity of the material in the preimplantation embryo to test for molecular analysis. To address this problem, we generated mouse embryonic stem cells (mESC from blastocysts conceived after natural mating (mESCFB or after IVF, using optimal (KSOM + 5% O2; mESCKAA and suboptimal (Whitten's Medium, + 20% O2, mESCWM conditions. All three groups of embryos showed similar behavior during both derivation and differentiation into their respective mESC lines. Unsupervised hierarchical clustering of microarray data showed that blastocyst culture does not affect the transcriptome of derived mESCs. Transcriptomic changes previously observed in the inner cell mass (ICM of embryos derived in the same conditions were not present in mESCs, regardless of method of conception or culture medium, suggesting that mESC do not fully maintain a memory of the events occurring prior to their derivation. We conclude that the fertilization method or culture media used to generate blastocysts does not affect differentiation potential, morphology and transcriptome of mESCs.

  17. A murine specific expansion of the Rhox cluster involved in embryonic stem cell biology is under natural selection

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    Keebler Jon

    2006-08-01

    Full Text Available Abstract Background The rodent specific reproductive homeobox (Rhox gene cluster on the X chromosome has been reported to contain twelve homeobox-containing genes, Rhox1-12. Results We have identified a 40 kb genomic region within the Rhox cluster that is duplicated eight times in tandem resulting in the presence of eight paralogues of Rhox2 and Rhox3 and seven paralogues of Rhox4. Transcripts have been identified for the majority of these paralogues and all but three are predicted to produce full-length proteins with functional potential. We predict that there are a total of thirty-two Rhox genes at this genomic location, making it the most gene-rich homoeobox cluster identified in any species. From the 95% sequence similarity between the eight duplicated genomic regions and the synonymous substitution rate of the Rhox2, 3 and 4 paralogues we predict that the duplications occurred after divergence of mouse and rat and represent the youngest homoeobox cluster identified to date. Molecular evolutionary analysis reveals that this cluster is an actively evolving region with Rhox2 and 4 paralogues under diversifying selection and Rhox3 evolving neutrally. The biological importance of this duplication is emphasised by the identification of an important role for Rhox2 and Rhox4 in regulating the initial stages of embryonic stem (ES cell differentiation. Conclusion The gene rich Rhox cluster provides the mouse with significant biological novelty that we predict could provide a substrate for speciation. Moreover, this unique cluster may explain species differences in ES cell derivation and maintenance between mouse, rat and human.

  18. Expression and function of cannabinoid receptors CB1 and CB2 and their cognate cannabinoid ligands in murine embryonic stem cells.

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    Shuxian Jiang

    Full Text Available BACKGROUND: Characterization of intrinsic and extrinsic factors regulating the self-renewal/division and differentiation of stem cells is crucial in determining embryonic stem (ES cell fate. ES cells differentiate into multiple hematopoietic lineages during embryoid body (EB formation in vitro, which provides an experimental platform to define the molecular mechanisms controlling germ layer fate determination and tissue formation. METHODS AND FINDINGS: The cannabinoid receptor type 1 (CB1 and cannabinoid receptor type 2 (CB2 are members of the G-protein coupled receptor (GPCR family, that are activated by endogenous ligands, the endocannabinoids. CB1 receptor expression is abundant in brain while CB2 receptors are mostly expressed in hematopoietic cells. However, the expression and the precise roles of CB1 and CB2 and their cognate ligands in ES cells are not known. We observed significant induction of CB1 and CB2 cannabinoid receptors during the hematopoietic differentiation of murine ES (mES-derived embryoid bodies. Furthermore, mES cells as well as ES-derived embryoid bodies at days 7 and 14, expressed endocannabinoids, the ligands for both CB1 and CB2. The CB1 and CB2 antagonists (AM251 and AM630, respectively induced mES cell death, strongly suggesting that endocannabinoids are involved in the survival of mES cells. Treatment of mES cells with the exogenous cannabinoid ligand Delta(9-THC resulted in the increased hematopoietic differentiation of mES cells, while addition of AM251 or AM630 blocked embryoid body formation derived from the mES cells. In addition, cannabinoid agonists induced the chemotaxis of ES-derived embryoid bodies, which was specifically inhibited by the CB1 and CB2 antagonists. CONCLUSIONS: This work has not been addressed previously and yields new information on the function of cannabinoid receptors, CB1 and CB2, as components of a novel pathway regulating murine ES cell differentiation. This study provides insights

  19. Characterization of an in vitro differentiation assay for pancreatic-like cell development from murine embryonic stem cells: detailed gene expression analysis.

    Science.gov (United States)

    Chen, Chialin; Chai, Jing; Singh, Lipi; Kuo, Ching-Ying; Jin, Liang; Feng, Tao; Marzano, Scott; Galeni, Sheetal; Zhang, Nan; Iacovino, Michelina; Qin, Lihui; Hara, Manami; Stein, Roland; Bromberg, Jonathan S; Kyba, Michael; Ku, Hsun Teresa

    2011-08-01

    Embryonic stem (ES) cell technology may serve as a platform for the discovery of drugs to treat diseases such as diabetes. However, because of difficulties in establishing reliable ES cell differentiation methods and in creating cost-effective plating conditions for the high-throughput format, screening for molecules that regulate pancreatic beta cells and their immediate progenitors has been limited. A relatively simple and inexpensive differentiation protocol that allows efficient generation of insulin-expressing cells from murine ES cells was previously established in our laboratories. In this report, this system is characterized in greater detail to map developmental cell stages for future screening experiments. Our results show that sequential activation of multiple gene markers for undifferentiated ES cells, epiblast, definitive endoderm, foregut, and pancreatic lineages was found to follow the sequence of events that mimics pancreatic ontogeny. Cells that expressed enhanced green fluorescent protein, driven by pancreatic and duodenal homeobox 1 or insulin 1 promoter, correctly expressed known beta cell lineage markers. Overexpression of Sox17, an endoderm fate-determining transcription factor, at a very early stage of differentiation (days 2-3) enhanced pancreatic gene expression. Overexpression of neurogenin3, an endocrine progenitor cell marker, induced glucagon expression at stages when pancreatic and duodenal homeobox 1 message was present (days 10-16). Forced expression (between days 16 and 25) of MafA, a pancreatic maturation factor, resulted in enhanced expression of insulin genes, glucose transporter 2 and glucokinase, and glucose-responsive insulin secretion. Day 20 cells implanted in vivo resulted in pancreatic-like cells. Together, our differentiation assay recapitulates the proceedings and behaviors of pancreatic development and will be valuable for future screening of beta cell effectors.

  20. DNA oxidation as a potential molecular mechanism mediating drug-induced birth defects: phenytoin and structurally related teratogens initiate the formation of 8-hydroxy-2'-deoxyguanosine in vitro and in vivo in murine maternal hepatic and embryonic tissues.

    Science.gov (United States)

    Liu, L; Wells, P G

    1995-11-01

    A considerable number of teratogens, including the anticonvulsant drug phenytoin and structurally related drugs and environmental chemicals, may be bioactivated by peroxidases, such as prostaglandin H synthase (PHS) and lipoxygenases (LPOs), to a reactive free radical intermediate that initiates birth defects. However, the molecular targets of the reactive free radical intermediates mediating chemical teratogenesis, and hence the fundamental determinants of susceptibility, are poorly understood. In these studies, a teratogenic dose of phenytoin (65 mg/kg), when injected into pregnant CD-1 mice during organogenesis on gestational day 12, initiated the oxidation of DNA in maternal hepatic and embryonic nuclei, forming 8-hydroxy-2'-deoxyguanosine. Significant maternal and embryonic DNA oxidation occurred at 6 and 3 h, respectively, suggesting relative embryonic deficiencies in free radical-related cytoprotective enzymes, although the rates appeared similar. Maximal DNA oxidation in both maternal and embryonic tissues occurred at 6 h, presumably reflecting the balance of DNA oxidation and repair, the latter of which appeared similar in both tissues. Inhibition of phenytoin-initiated embryonic DNA oxidation by the free radical spin trapping agent alpha-phenyl-N-t-butylnitrone (41.5 mg/kg), and by acetylsalicylic acid (10 mg/kg), an inhibitor of the cyclooxygenase component of PHS, was consistent with the previously reported reduction by these inhibitors of phenytoin-initiated murine birth defects. In vitro studies using a horseradish peroxidase (0.5 mg/ml)-H2O2 (5.45 micrograms/ml) bioactivating system for drug-initiated oxidation of 2'-deoxyguanosine (3.74 mM), indicated that the potency of xenobiotic-initiated formation of 8-hydroxy-2'-deoxyguanosine for the structurally related drugs and metabolites phenytoin, 5-(p-hydroxyphenyl)-5-phenylhydantoin, trimethadione, dimethadione, l-mephenytoin, l-nirvanol, d-nirvanol (80 microM each), or thalidomide (64 micro

  1. Derivation of vascular endothelial cells from human embryonic stem cells under GMP-compliant conditions: towards clinical studies in ischaemic disease.

    Science.gov (United States)

    Kaupisch, A; Kennedy, L; Stelmanis, V; Tye, B; Kane, N M; Mountford, J C; Courtney, A; Baker, A H

    2012-10-01

    Revascularisation of ischaemic tissue remains an area of substantial unmet clinical need in cardiovascular disease. Strategies to induce therapeutic angiogenesis are therefore attractive. Our recent focus has been on human embryonic stem cell (hESC) strategies since hESC can be maintained in a pluripotent state or differentiated into any desired cell type, including endothelial cells (EC), under defined differentiation culture conditions. We recently published a protocol for non-good manufacturing practice (GMP) feeder- and serum-free hESC-EC-directed monolayer differentiation to vascular EC demonstrating the potential to generate hESC-derived EC in a GMP-compliant manner suitable for use in clinical trials. In this study we modified that laboratory protocol to GMP compliance. EC production was confirmed by flow cytometry, qRT-PCR and production of vascular structures in Matrigel®, yielding approximately 30 % mature VE-cadherin(+)/PECAM-1(+) cells using the GMP-compliant hESC line RC13. In conclusion, we have successfully demonstrated the production of vascular EC under GMP-compliant conditions suitable for clinical evaluation.

  2. Three-dimensional co-cultures of human endothelial cells and embryonic stem cell-derived pericytes inside a microfluidic device.

    Science.gov (United States)

    van der Meer, Andries D; Orlova, Valeria V; ten Dijke, Peter; van den Berg, Albert; Mummery, Christine L

    2013-09-21

    Organs-on-chips are microengineered in vitro tissue structures that can be used as platforms for physiological and pathological research. They provide tissue-like microenvironments in which different cell types can be co-cultured in a controlled manner to create synthetic organ mimics. Blood vessels are an integral part of all tissues in the human body. Development of vascular structures is therefore an important research topic for advancing the field of organs-on-chips since generated tissues will require a blood or nutrient supply. Here, we have engineered three-dimensional constructs of vascular tissue inside microchannels by injecting a mixture of human umbilical vein endothelial cells, human embryonic stem cell-derived pericytes (the precursors of vascular smooth muscle cells) and rat tail collagen I into a polydimethylsiloxane microfluidic channel with dimensions 500 μm × 120 μm × 1 cm (w × h × l). Over the course of 12 h, the cells organized themselves into a single long tube resembling a blood vessel that followed the contours of the channel. Detailed examination of tube morphology by confocal microscopy revealed a mature endothelial monolayer with complete PECAM-1 staining at cell-cell contacts and pericytes incorporated inside the tubular structures. We also demonstrated that tube formation was disrupted in the presence of a neutralizing antibody against transforming growth factor-beta (TGF-β). The TGF-β signaling pathway is essential for normal vascular development; deletion of any of its components in mouse development results in defective vasculogenesis and angiogenesis and mutations in humans have been linked to multiple vascular genetic diseases. In the engineered microvessels, inhibition of TGF-β signaling resulted in tubes with smaller diameters and higher tortuosity, highly reminiscent of the abnormal vessels observed in patients with one particular vascular disease known as hereditary hemorrhagic telangiectasia (HHT). In summary, we have

  3. Promoters of the murine embryonic β-like globin genes Ey and βh1 do not compete for interaction with the β-globin locus control region

    Science.gov (United States)

    Hu, Xiao; Bulger, Michael; Roach, Julia N.; Eszterhas, Susan K.; Olivier, Emmanuel; Bouhassira, Eric E.; Groudine, Mark T.; Fiering, Steven

    2003-01-01

    Mammalian β-globin loci contain multiple β-like genes that are expressed at different times during development. The murine β-globin locus contains two genes expressed during the embryo stage, Ey and βh1, and two genes expressed at both the fetal and postnatal stages, β-major and β-minor. Studies of transgenic human β-like globin loci in mice have suggested that expression of one gene at the locus will suppress expression of other genes at the locus. To test this hypothesis we produced mouse lines with deletions of either the Ey or βh1 promoter in the endogenous murine β-globin locus. Promoter deletion eliminated expression of the mutant gene but did not affect expression of the remaining embryonic gene or the fetal/adult β-globin genes on the mutant allele. These results demonstrate a lack of competitive effects between individual mouse embryonic β-globin gene promoters and other genes in the locus. The implication of these findings for models of β-globin gene expression are discussed. PMID:12525692

  4. Endothelial dysfunction is a potential contributor to multiple organ failure and mortality in aged mice subjected to septic shock: preclinical studies in a murine model of cecal ligation and puncture.

    Science.gov (United States)

    Coletta, Ciro; Módis, Katalin; Oláh, Gábor; Brunyánszki, Attila; Herzig, Daniela S; Sherwood, Edward R; Ungvári, Zoltán; Szabo, Csaba

    2014-09-16

    The goal of the current study was to investigate the effect of aging on the development of endothelial dysfunction in a murine model of sepsis, and to compare it with the effect of genetic deficiency of the endothelial isoform of nitric oxide synthase (eNOS). Cecal ligation and puncture (CLP) was used to induce sepsis in mice. Survival rates were monitored and plasma indices of organ function were measured. Ex vivo studies included the measurement of vascular function in thoracic aortic rings, assessment of oxidative stress/cellular injury in various organs and the measurement of mitochondrial function in isolated liver mitochondria. eNOS deficiency and aging both exacerbated the mortality of sepsis. Both eNOS-deficient and aged mice exhibited a higher degree of sepsis-associated multiple organ dysfunction syndrome (MODS), infiltration of tissues with mononuclear cells and oxidative stress. A high degree of sepsis-induced vascular oxidative damage and endothelial dysfunction (evidenced by functional assays and multiple plasma markers of endothelial dysfunction) was detected in aortae isolated from both eNOS(-/-) and aged mice. There was a significant worsening of sepsis-induced mitochondrial dysfunction, both in eNOS-deficient mice and in aged mice. Comparison of the surviving and non-surviving groups of animals indicated that the severity of endothelial dysfunction may be a predictor of mortality of mice subjected to CLP-induced sepsis. Based on the studies in eNOS mice, we conclude that the lack of endothelial nitric oxide production, on its own, may be sufficient to markedly exacerbate the severity of septic shock. Aging markedly worsens the degree of endothelial dysfunction in sepsis, yielding a significant worsening of the overall outcome. Thus, endothelial dysfunction may constitute an early predictor and independent contributor to sepsis-associated MODS and mortality in aged mice.

  5. Comparison of toxicity of benzene metabolite hydroquinone in hematopoietic stem cells derived from murine embryonic yolk sac and adult bone marrow.

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    Jie Zhu

    Full Text Available Benzene is an occupational toxicant and an environmental pollutant that potentially causes hematotoxicity and leukemia in exposed populations. Epidemiological studies suggest an association between an increased incidence of childhood leukemia and benzene exposure during the early stages of pregnancy. However, experimental evidence supporting the association is lacking at the present time. It is believed that benzene and its metabolites target hematopoietic stem cells (HSCs to cause toxicity and cancer in the hematopoietic system. In the current study, we compared the effects of hydroquinone (HQ, a major metabolite of benzene in humans and animals, on mouse embryonic yolk sac hematopoietic stem cells (YS-HSCs and adult bone marrow hematopoietic stem cells (BM-HSCs. YS-HSCs and BM-HSCs were isolated and enriched, and were exposed to HQ at increasing concentrations. HQ reduced the proliferation and the differentiation and colony formation, but increased the apoptosis of both YS-HSCs and BM-HSCs. However, the cytotoxic and apoptotic effects of HQ were more apparent and reduction of colony formation by HQ was more severe in YS-HSCs than in BM-HSCs. Differences in gene expression profiles were observed in HQ-treated YS-HSCs and BM-HSCs. Cyp4f18 was induced by HQ both in YS-HSCs and BM-HSCs, whereas DNA-PKcs was induced in BM-HSCs only. The results revealed differential effects of benzene metabolites on embryonic and adult HSCs. The study established an experimental system for comparison of the hematopoietic toxicity and leukemogenicity of benzene and metabolites during mouse embryonic development and adulthood.

  6. Soluble factors from bone marrow endothelial cells regulate differentiation and proliferation of hematopoietic and endothelial lineages and embryonic stem cells%骨髓内皮细胞来源的可溶性因子调节造血系、内皮系及胚胎干细胞的分化和增殖

    Institute of Scientific and Technical Information of China (English)

    王绮如; 阎琦

    2013-01-01

    We have established a bone marrow endothelial cell line.This review focuses on the elucidation and analysis of the effects of this bone marrow endothelial cell-conditioned medium (BMEC-CM) on the differentiation and proliferation of hematopoietic and endothelial progenitors as well as embryonic stem cells (ESCs).We will review that (1) BMEC-CM promotes proliferation and differentiation of hematopoietic lineage; (2) BMEC-CM promotes proliferation and differentiation of endothelial lineage; (3) BMECCM induces differentiation of hematopoietic stem cells/progenitors into endothelial progenitors; and (4) BMEC-CM induces differentiation of ESCs into hematopoietic cells and endothelial cells.We conclude that the soluble factors secreted by BMECs are able to support the proliferation and differentiation of hematopoietic and endothelium lineages.Moreover,these soluble factors induce hematopoietic cells to differentiate to endothelial cells,and induce ESCs to differentiate towards both endothelial cells and hematopoietic cells.Therefore,this work provides evidence that a close relationship involved in the development of hematopoietic and endothelial lineage.This disclosure will be beneficial for therapy strategy in the treatment of ischemic and tumor diseases,and improve our understanding of the relationship between hematopoietic and endothelial lineages.%本研究室建立了一支骨髓内皮细胞(bone marrow endothelial cell,BMEC)株.本文综述了这一内皮细胞株细胞的条件培养液(bone marrow endothelial cell-conditioned medium,BMEC-CM)对造血系、内皮系及胚胎干细胞的分化增殖的作用.(1)BMEC-CM促进造血系细胞的分化和增殖;(2) BMEC-CM促进内皮系细胞的分化和增殖;(3) BMEC-CM诱导造血干/祖细胞向内皮系细胞分化;(4) BMEC-CM诱导胚胎干细胞分化为造血细胞和内皮细胞.以上研究成果提示,骨髓内皮细胞分泌可溶性因子支持造血系及内皮系细胞的分化与增殖,促进造

  7. In vitro and in vivo study of pluripotency in intraspecific hybrid cells obtained by fusion of murine embryonic stem cells with splenocytes.

    Science.gov (United States)

    Matveeva, N M; Shilov, A G; Kaftanovskaya, E M; Maximovsky, L P; Zhelezova, A I; Golubitsa, A N; Bayborodin, S I; Fokina, M M; Serov, O L

    1998-06-01

    Hypoxanthine phosphoribosyltransferase-deficient (HPRT-) mouse embryonic stem (ES) cells, HM-1 cells (genotype XY), were fused with adult female DD/c mouse spleen cells. As a result, a set of HAT-resistant clones was isolated. Four hybrid clones most similar in morphology and growth characteristics to the HM-1 cells were studied in detail with respect to their pluripotency. Of these, three clones contained 41-43 chromosomes, and one clone was nearly tetraploid. All the clones had the XXY set of sex chromosomes and expressed the HPRT of the somatic partner only. The hybrid clones shared features with the HM-1 cells, indicating that they retained their pluripotent properties: (1) embryonic ECMA-7 antigen, not TROMA-1 antigen, was present in most cells; (2) the hybrid cells showed high activity of endogenous alkaline phosphatase (AP); (3) all the hybrid clones were able to form complex embryoid bodies containing derivatives of all the embryonic germinal layers; (4) the hybrid cells contained synchronously replicating X chromosomes, indicating that they were in an active state; and (5) a set of chimeric animals was generated by injecting hybrid cells into BALB/c and C57BL/6J mouse blastocysts. Evidence for chimerism was provided by the spotted coat derived from 129/Ola mice and identification of 129/Ola glucose phosphate isomerase (GPI) in many organs. Thus the results obtained demonstrated that the hybrid cells retain their high pluripotency level despite the close contact of the "pluripotent" HM-1 genome with the "somatic" spleen cell genome during hybrid cell formation and the presence of the "somatic" X chromosome during many cell generations. The presence of HPRT of the somatic partner in many organs and tissues, including the testes in chimeric animals, shows that the "somatic" X chromosome segregates weakly, if at all, during development of the chimeras. There were no individuals with the 129/Ola genotype among the more than 50 offspring from chimeric mice. The

  8. Directed Differentiation of Dopamine-Secreting Cells from Nurr1/GPX1 Expressing Murine Embryonic Stem Cells Cultured on Matrigel-Coated PCL Scaffolds.

    Science.gov (United States)

    Terraf, Panieh; Babaloo, Hamideh; Kouhsari, Shideh Montasser

    2017-03-01

    Parkinson's disease (PD) is a progressive neurological disorder characterized by a large number of motor and non-motor features and is known as the second most common neurodegenerative disorder after Alzheimer's disease. The hallmark pathology of PD is the damage and death of dopamine-producing neurons in the substantia-nigra of midbrain. Intrastriatal transplants of fetal mesencephalon derived DAergic neurons have provided proof-of-principle for the cell replacement strategy and have demonstrated reinnervation of the denervated striatum. However, ethical, technical, and practical limitations of deploying fetal DAergic neurons as the source for cell therapy in PD have ceased the spread of this procedure into clinical practice. Embryonic stem (ES) cells have emerged as a therapeutic alternative that can proliferate extensively and generate dopamine-producing neurons. To this extent and to surmount the obstacles related to embryonic neural cells, many investigations have focused on using pluripotent stem cells for the derivation of DAergic neurons. In the present study, a mouse embryonic stem (mES) R1 cell line was generated which could stably co-express Nurr1 (an essential transcription factor in DAergic neuron development) and GPX-1 (a neuroprotective enzyme against oxidative stress). The Nurr1/GPX-1-expressing ES cells (Nurr1/GPX-1-ES) were differentiated into DAergic-like cells via a three-dimensional culture environment consisting of Poly-ε-Caprolactone (PCL) nanofibrous scaffolds embedded by Matrigel (Mtg) in the presence of specific signaling molecules. DAergic neuron-specific genes were highly expressed in ES-derived DAergic neurons cultured and differentiated on PCL/Mtg scaffolds. Reverse-phase HPLC confirmed that the Nurr1/GPX-1-ES-cells differentiated on PCL/Mtg electrospun scaffolds could efficiently and exclusively secrete dopamine in response to stimulus. In conclusion, our results demonstrated that PCL/Matrigel nanofibrous scaffolds could efficiently

  9. The synergistic effect of beta-boswellic acid and Nurr1 overexpression on dopaminergic programming of antioxidant glutathione peroxidase-1-expressing murine embryonic stem cells.

    Science.gov (United States)

    Abasi, M; Massumi, M; Riazi, G; Amini, H

    2012-10-11

    Parkinson's disease (PD) is a neurodegenerative disorder in which the nigro-striatal dopaminergic (DAergic) neurons have been selectively lost. Due to side effects of levodopa, a dopamine precursor drug, recently cell replacement therapy for PD has been considered. Lack of sufficient amounts of, embryos and ethical problems regarding the use of dopamine-rich embryonic neural cells have limited the application of these cells for PD cell therapy. Therefore, many investigators have focused on using the pluripotent stem cells to generate DAergic neurons. This study is aimed first to establish a mouse embryonic stem (mES) cell line that can stably co-express Nurr1 (Nuclear receptor subfamily 4, group A, member 2) transcription factor in order to efficiently generate DAergic neurons, and glutathione peroxidase-1 (GPX-1) to protect the differentiated DAergic-like cells against oxidative stress. In addition to genetic engineering of ES cells, the effect of Beta-boswellic acid (BBA) on DAergic differentiation course of mES cells was sought in the present study. To that end, the feeder-independent CGR8 mouse embryonic stem cells were transduced by Nurr1- and GPX-1-harboring Lentiviruses and the generated Nurr1/GPX-1-expresssing ES clones were characterized and verified. Gene expression analyses demonstrated that BBA treatment and overexpression of Nurr1 has a synergistic effect on derivation of DAergic neurons from Nurr1/GPX-1-expressing ES cells. The differentiated cells could exclusively synthesize and secrete dopamine in response to stimuli. Overexpression of GPX-1 in genetically engineered Nurr1/GPX-1-ES cells increased the viability of these cells during their differentiation into CNS stem cells. In conclusion, the results demonstrated that Nurr1-overexpressing feeder-independent ES cells like the feeder-dependent ES cells, can be efficiently programmed into functional DAergic neurons and additional treatment of cells by BBA can even augment this efficiency. GPX-1

  10. CRISPR/Cas9-Mediated Genomic Deletion of the Beta-1, 4 N-acetylgalactosaminyltransferase 1 Gene in Murine P19 Embryonal Carcinoma Cells Results in Low Sensitivity to Botulinum Neurotoxin Type C.

    Directory of Open Access Journals (Sweden)

    Kentaro Tsukamoto

    Full Text Available Botulinum neurotoxins produced by Clostridium botulinum cause flaccid paralysis by inhibiting neurotransmitter release at peripheral nerve terminals. Previously, we found that neurons derived from the murine P19 embryonal carcinoma cell line exhibited high sensitivity to botulinum neurotoxin type C. In order to prove the utility of P19 cells for the study of the intracellular mechanism of botulinum neurotoxins, ganglioside-knockout neurons were generated by deletion of the gene encoding beta-1,4 N-acetylgalactosaminyltransferase 1 in P19 cells using the clustered regularly interspaced short palindromic repeats combined with Cas9 (CRISPR/Cas9 system. By using this system, knockout cells could be generated more easily than with previous methods. The sensitivity of the generated beta-1,4 N-acetylgalactosaminyltransferase 1-depleted P19 neurons to botulinum neurotoxin type C was decreased considerably, and the exogenous addition of the gangliosides GD1a, GD1b, and GT1b restored the susceptibility of P19 cells to botulinum neurotoxin type C. In particular, addition of a mixture of these three ganglioside more effectively recovered the sensitivity of knockout cells compared to independent addition of GD1a, GD1b, or GT1b. Consequently, the genome-edited P19 cells generated by the CRISPR/Cas9 system were useful for identifying and defining the intracellular molecules involved in the toxic action of botulinum neurotoxins.

  11. ­Glial and stem cell expression of murine Fibroblast Growth Factor Receptor 1 in the embryonic and perinatal nervous system

    Directory of Open Access Journals (Sweden)

    Jantzen C. Collette

    2017-06-01

    Full Text Available Background Fibroblast growth factors (FGFs and their receptors (FGFRs are involved in the development and function of multiple organs and organ systems, including the central nervous system (CNS. FGF signaling via FGFR1, one of the three FGFRs expressed in the CNS, stimulates proliferation of stem cells during prenatal and postnatal neurogenesis and participates in regulating cell-type ratios in many developing regions of the brain. Anomalies in FGFR1 signaling have been implicated in certain neuropsychiatric disorders. Fgfr1 expression has been shown, via in situ hybridization, to vary spatially and temporally throughout embryonic and postnatal development of the brain. However, in situ hybridization lacks sufficient resolution to identify which cell-types directly participate in FGF signaling. Furthermore, because antibodies raised against FGFR1 commonly cross-react with other members of the FGFR family, immunocytochemistry is not alone sufficient to accurately document Fgfr1 expression. Here, we elucidate the identity of Fgfr1 expressing cells in both the embryonic and perinatal mouse brain. Methods To do this, we utilized a tgFGFR1-EGFPGP338Gsat BAC line (tgFgfr1-EGFP+ obtained from the GENSAT project. The tgFgfr1-EGFP+ line expresses EGFP under the control of a Fgfr1 promoter, thereby causing cells endogenously expressing Fgfr1 to also present a positive GFP signal. Through simple immunostaining using GFP antibodies and cell-type specific antibodies, we were able to accurately determine the cell-type of Fgfr1 expressing cells. Results This technique revealed Fgfr1 expression in proliferative zones containing BLBP+ radial glial stem cells, such as the cortical and hippocampal ventricular zones, and cerebellar anlage of E14.5 mice, in addition to DCX+ neuroblasts. Furthermore, our data reveal Fgfr1 expression in proliferative zones containing BLBP+ cells of the anterior midline, hippocampus, cortex, hypothalamus, and cerebellum of P0.5 mice

  12. A co-culture model of the hippocampal neurogenic niche reveals differential effects of astrocytes, endothelial cells and pericytes on proliferation and differentiation of adult murine precursor cells

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    Fanny Ehret

    2015-11-01

    Full Text Available The niche concept of stem cell biology proposes a functional unit between the precursor cells and their local microenvironment, to which several cell types might contribute by cell–cell contacts, extracellular matrix, and humoral factors. We here established three co-culture models (with cell types separated by membrane for both adherent monolayers and neurospheres to address the potential influence of different niche cell types in the neurogenic zone of the adult hippocampus of mice. Astrocytes and endothelial cells enhanced precursor cell proliferation and neurosphere formation. Endothelial factors also led to a prolonged increase in proliferation after growth factor withdrawal, which otherwise induces differentiation. All niche cell types enhanced cell survival in monolayer cultures, endothelial cells also stimulated neuronal differentiation. A parallel trend elicited by astrocytes did not reach conventional statistical significance. Pericytes had variable effects here. We did not observe changes in differentiation in neurosphere co-cultures. In summary, our data indicate that in precursor cell culture protocols survival could be improved by adding as yet unknown factors physiologically contributed by astrocytes and endothelial cells. Our findings also underscore the complexity of the niche and the differential impact of factors from the different sources on distinct aspects of neuronal development. With the help of the models presented here, identification of these factors and their specific biological activity can now be initiated.

  13. Regulation of glycan structures in murine embryonic stem cells: combined transcript profiling of glycan-related genes and glycan structural analysis.

    Science.gov (United States)

    Nairn, Alison V; Aoki, Kazuhiro; dela Rosa, Mitche; Porterfield, Mindy; Lim, Jae-Min; Kulik, Michael; Pierce, J Michael; Wells, Lance; Dalton, Stephen; Tiemeyer, Michael; Moremen, Kelley W

    2012-11-02

    The abundance and structural diversity of glycans on glycoproteins and glycolipids are highly regulated and play important roles during vertebrate development. Because of the challenges associated with studying glycan regulation in vertebrate embryos, we have chosen to study mouse embryonic stem (ES) cells as they differentiate into embryoid bodies (EBs) or into extraembryonic endodermal (ExE) cells as a model for cellular differentiation. We profiled N- and O-glycan structures isolated from these cell populations and examined transcripts encoding the corresponding enzymatic machinery for glycan biosynthesis in an effort to probe the mechanisms that drive the regulation of glycan diversity. During differentiation from mouse ES cells to either EBs or ExE cells, general trends were detected. The predominance of high mannose N-glycans in ES cells shifted to an equal abundance of complex and high mannose structures, increased sialylation, and increased α-Gal termination in the differentiated cell populations. Whereas core 1 O-glycan structures predominated in all three cell populations, increased sialylation and increased core diversity characterized the O-glycans of both differentiated cell types. Increased polysialylation was also found in both differentiated cell types. Differences between the two differentiated cell types included greater sialylation of N-glycans in EBs, whereas α-Gal-capped structures were more prevalent in ExE cells. Changes in glycan structures generally, but not uniformly, correlated with alterations in transcript abundance for the corresponding biosynthetic enzymes, suggesting that transcriptional regulation contributes significantly to the regulation of glycan expression. Knowledge of glycan structural diversity and transcript regulation should provide greater understanding of the roles of protein glycosylation in vertebrate development.

  14. Time-dependence of cardiomyocyte differentiation disturbed by peroxisome proliferator-activated receptor a inhibitor GW6471 in murine embryonic stem cells in vitro

    Institute of Scientific and Technical Information of China (English)

    Ling DING; Xing-guang LIANG; Yi-jia LOU

    2007-01-01

    Aim: To investigate the possible roles of peroxisome proliferator-activated recep-tor α (PPARα) and the signal pathway regulating the transcription of PPARα in the cardiomyocyte differentiation course of marine embryonic stem (ES) cells in vitro. Methods: The expression of PPARa during cardiomyocyte differentiation was analyzed using both Western blotting and immunofluorescence. Cardiac specific genes and sarcomeric proteins were evaluated when embryoid bodies were challenged with PPARα specific inhibitor GW6471 at different time courses.The phosphorylation of p38 mitogen-activated protein kinase (MAPK) was stud-ied in the differentiation process, and its specific inhibitor SB203580 was em-ployed to study the function of p38 MAPK on cardiac differentiation and the expression of PPARα. Results: The expression of PPARα was observed to be at a low level in undifferentiated ES cells and markedly induced with the appearance of beating clusters. The inhibition of PPARa by its specific inhibitor GW6471 (1 x 10-5 mol/L) significantly prevented cardiomyocyte differentiation and resulted in the reduced expression of cardiac sarcomeric proteins (ie α-actinin, troponin-T) and specific genes (ie α-MHC, MLC2v) in a time-dependent manner. In the differ-entiation course, p-p38 MAPK was maintained at a high level from d 3 followed by a decrease from d 10. The inhibition of the p38 MAPK pathway by SB203580 between d 3 and d 7 efficiently prevented cardiomyocyte differentiation and re-sulted in the capture of the upregulation of PPARα. Conclusion: Taken together,these results showed a close association between PPARα and cardiomyocyte differentiation in vitro, and p38 MAPK was partly responsible for the regulation of PPARα.

  15. Palm tocotrienols decrease levels of pro-angiogenic markers in human umbilical vein endothelial cells (HUVEC) and murine mammary cancer cells.

    Science.gov (United States)

    Selvaduray, Kanga Rani; Radhakrishnan, Ammu K; Kutty, Methil Kannan; Nesaretnam, Kalanithi

    2012-01-01

    Anti-angiogenic therapy is widely being used to halt tumour angiogenesis. In this study, the anti-angiogenic activity of palm tocotrienol-rich fraction (TRF) and its individual components (γ- and δ-tocotrienol) were first investigated in vitro in human umbilical vein endothelial cells (HUVEC) and 4T1 mouse mammary cancer cells. Results showed reduced levels of Interkeukin (IL)-8 and IL-6, two pro-angiogenic cytokines in HUVEC treated with palm tocotrienols compared with α-tocopherol (α-T) and control cells (P < 0.05). The production of IL-8 and IL-6 was lowest in δ-tocotrienol (δ-T3)-treated cells followed by γ-tocotrienol (γ-T3) and TRF. There was significant (P < 0.05) reduction in IL-8 and vascular endothelial growth factor (VEGF) production in 4T1 cells treated with TRF or δ-T3. There was decreased expression of VEGF and its receptors; VEGF-R1 (fms-like tyrosine kinase, Flt-1) and VEGF-R2 (Kinase-insert-domain-containing receptor, KDR/Flk-2) in tumour tissues excised from mice supplemented with TRF were observed. There was also decreased expression of VEGF-R2 in lung tissues of mice supplemented with TRF. These observations correlate with the smaller tumour size recorded in the tocotrienol-treated mice. This study confirms previous observations that palm tocotrienols exhibit anti-angiogenic properties that may inhibit tumour progression.

  16. Tie-1-directed expression of Cre recombinase in endothelial cells of embryoid bodies and transgenic mice

    DEFF Research Database (Denmark)

    Gustafsson, E; Brakebusch, C; Hietanen, K

    2001-01-01

    the production and screening of multiple transgenic lines we used embryonic stem cell and embryoid body technology to identify recombinant embryonic stem cell clones with high, endothelial-specific Cre activity. One embryonic stem cell clone that showed high Cre activity in endothelial cells was used to generate...

  17. Enhanced inhibition of murine prostatic carcinoma growth by immunization with or administration of viable human umbilical vein endothelial cells and CRM197

    Directory of Open Access Journals (Sweden)

    Zhang Huiyong

    2011-02-01

    Full Text Available Vaccination with xenogeneic and syngeneic endothelial cells is effective for inhibiting tumor growth. Nontoxic diphtheria toxin (CRM197, as an immunogen or as a specific inhibitor of heparin-binding EGF-like growth factor, has shown promising antitumor activity. Therefore, immunization with or administration of viable human umbilical vein endothelial cells (HUVECs combined with CRM197 could have an enhanced antitumor effect. Six-week-old C57BL/6J male mice were vaccinated with viable HUVECs, 1 x 10(6 viable HUVECs combined with 100 μg CRM197, or 100 μg CRM197 alone by ip injections once a week for 4 consecutive weeks. RM-1 cells (5 x 10(5 were inoculated by sc injection as a preventive procedure. During the therapeutic procedure, 6-week-old male C57BL/6J mice were challenged with 1 x 10(5 RM-1 cells, then injected sc with 1 x 10(6 viable HUVECs, 1 x 10(6 viable HUVECs + 100 μg CRM197, and 100 μg CRM197 alone twice a week for 4 consecutive weeks. Tumor volume and life span were monitored. We also investigated the effects of immunization with HUVECs on the aortic arch wall and on wound healing. Vaccination with or administration of viable HUVECs+CRM197 enhanced the inhibition of RM-1 prostatic carcinoma by 24 and 29%, respectively, and prolonged the life span for 3 and 4 days, respectively, compared with those of only vaccination or administration with viable HUVECs of tumor-bearing C57BL/6J mice. Furthermore, HUVEC immunization caused some damage to the aortic arch wall but did not have remarkable effects on the rate of wound healing; the wounds healed in approximately 13 days. Treatment with CRM197 in combination with viable HUVECs resulted in a marked enhancement of the antitumor effect in the preventive or therapeutic treatment for prostatic carcinoma in vivo, suggesting a novel combination for anti-cancer therapy.

  18. Establishment of murine Smad5 double knockout ES cells and the studies on their properties

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Smad5 is an intracellular transducer of TGF-b signals. Targeteddisruption of murine Smad5 gene resulted in embryonic lethal. To study the function of Smad5 in organgenesis, we generated Smad5 double knockout ES cells by homologous recombination. We deleted the neo gene of the Smad5 targeted ES cells using Cre-LoxP system. Smad5 double knockout ES cells were obtained by transfecting the targeted ES cells using the same targeting construct. The results of chimeric study showed that Smad5 might play an important role during the development of heart and neural tube. Smad5 double knockout ES cells formed teratoma when injected subcutaneously into nude mice. They differentiated into several types of cells, including neural cells, muscle cells, chondrocytes, endothelial cells and glandaceous cells. Smad5 double knockout ES cells are useful for studying the function of Smad5 mediated TGF- b during the organgenesis and the in vitro differentiation of ES cells.

  19. Ultrasound Backscatter Microscopy Image-Guided Intraventricular Gene Delivery at Murine Embryonic Age 9.5 and 10.5 Produces Distinct Transgene Expression Patterns at the Adult Stage

    Directory of Open Access Journals (Sweden)

    Jiwon Jang

    2013-11-01

    Full Text Available In utero injection of a retroviral vector into the embryonic telencephalon aided by ultrasound backscatter microscopy permits introduction of a gene of interest at an early stage of development. In this study, we compared the tissue distribution of gene expression in adult mice injected with retroviral vectors at different embryonic ages in utero. Following ultrasound image-guided gene delivery (UIGD into the embryonic telencephalon, adult mice were subjected to whole-body luciferase imaging and immunohistochemical analysis at 6 weeks and 1 year postinjection. Luciferase activity was observed in a wide range of tissues in animals injected at embryonic age 9.5 (E9.5, whereas animals injected at E10.5 showed brain-localized reporter gene expression. These results suggest that mouse embryonic brain creates a closed and impermeable structure around E10. Therefore, by injecting a transgene before or after E10, transgene expression can be manipulated to be local or systemic. Our results also provide information that widens the applicability of UIGD beyond neuroscience studies.

  20. In vitro human embryonic stem cell hematopoiesis mimics MYB-independent yolk sac hematopoiesis.

    Science.gov (United States)

    Vanhee, Stijn; De Mulder, Katrien; Van Caeneghem, Yasmine; Verstichel, Greet; Van Roy, Nadine; Menten, Björn; Velghe, Imke; Philippé, Jan; De Bleser, Dominique; Lambrecht, Bart N; Taghon, Tom; Leclercq, Georges; Kerre, Tessa; Vandekerckhove, Bart

    2015-02-01

    Although hematopoietic precursor activity can be generated in vitro from human embryonic stem cells, there is no solid evidence for the appearance of multipotent, self-renewing and transplantable hematopoietic stem cells. This could be due to short half-life of hematopoietic stem cells in culture or, alternatively, human embryonic stem cell-initiated hematopoiesis may be hematopoietic stem cell-independent, similar to yolk sac hematopoiesis, generating multipotent progenitors with limited expansion capacity. Since a MYB was reported to be an excellent marker for hematopoietic stem cell-dependent hematopoiesis, we generated a MYB-eGFP reporter human embryonic stem cell line to study formation of hematopoietic progenitor cells in vitro. We found CD34(+) hemogenic endothelial cells rounding up and developing into CD43(+) hematopoietic cells without expression of MYB-eGFP. MYB-eGFP(+) cells appeared relatively late in embryoid body cultures as CD34(+)CD43(+)CD45(-/lo) cells. These MYB-eGFP(+) cells were CD33 positive, proliferated in IL-3 containing media and hematopoietic differentiation was restricted to the granulocytic lineage. In agreement with data obtained on murine Myb(-/-) embryonic stem cells, bright eGFP expression was observed in a subpopulation of cells, during directed myeloid differentiation, which again belonged to the granulocytic lineage. In contrast, CD14(+) macrophage cells were consistently eGFP(-) and were derived from eGFP-precursors only. In summary, no evidence was obtained for in vitro generation of MYB(+) hematopoietic stem cells during embryoid body cultures. The observed MYB expression appeared late in culture and was confined to the granulocytic lineage.

  1. Deregulation of Flk-1/vascular endothelial growth factor receptor-2 in fibroblast growth factor receptor-1-deficient vascular stem cell development.

    Science.gov (United States)

    Magnusson, Peetra; Rolny, Charlotte; Jakobsson, Lars; Wikner, Charlotte; Wu, Yan; Hicklin, Daniel J; Claesson-Welsh, Lena

    2004-03-15

    We have employed embryoid bodies derived from murine embryonal stem cells to study effects on vascular development induced by fibroblast growth factor (FGF)-2 and FGF receptor-1, in comparison to the established angiogenic factor vascular endothelial growth factor (VEGF)-A and its receptor VEGF receptor-2. Exogenous FGF-2 promoted formation of morphologically distinct, long slender vessels in the embryoid bodies, whereas VEGF-A-treated bodies displayed a compact plexus of capillaries. FGF-2 stimulation of embryonal stem cells under conditions where VEGF-A/VEGFR-2 function was blocked, led to formation of endothelial cell clusters, which failed to develop into vessels. FGFR-1(-/-) embryoid bodies responded to VEGF-A by establishment of the characteristic vascular plexus, but FGF-2 had no effect on vascular development in the absence of FGFR-1. The FGFR-1(-/-) embryoid bodies displayed considerably increased basal level of vessel formation, detected by immunohistochemical staining for platelet-endothelial cell adhesion molecule (PECAM)/CD31. This basal vascularization was blocked by neutralizing antibodies against VEGFR-2 or VEGF-A and biochemical analyses indicated changes in regulation of VEGFR-2 in the absence of FGFR-1 expression. We conclude that VEGF-A/VEGFR-2-dependent vessel formation occurs in the absence of FGF-2/FGFR-1, which, however, serve to modulate vascular development.

  2. Isolation, Characterization, and Transplantation of Cardiac Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Busadee Pratumvinit

    2013-01-01

    due to difficulties in isolation, cell heterogeneity, lack of specific markers to identify myocardial endothelial cells, and inadequate conditions to maintain long-term cultures. Herein, we developed a method for isolation, characterization, and expansion of cardiac endothelial cells applicable to study endothelial cell biology and clinical applications such as neoangiogenesis. First, we dissociated the cells from murine heart by mechanical disaggregation and enzymatic digestion. Then, we used flow cytometry coupled with specific markers to isolate endothelial cells from murine hearts. CD45+ cells were gated out to eliminate the hematopoietic cells. CD31+/Sca-1+ cells were isolated as endothelial cells. Cells isolated from atrium grew faster than those from ventricle. Cardiac endothelial cells maintain endothelial cell function such as vascular tube formation and acetylated-LDL uptake in vitro. Finally, cardiac endothelial cells formed microvessels in dorsal matrigel plug and engrafted in cardiac microvessels following intravenous and intra-arterial injections. In conclusion, our multicolor flow cytometry method is an effective method to analyze and purify endothelial cells from murine heart, which in turn can be ex vivo expanded to study the biology of endothelial cells or for clinical applications such as therapeutic angiogenesis.

  3. Murine Typhus

    Science.gov (United States)

    Dzul-Rosado, Karla R; Zavala Velázquez, Jorge Ernesto; Zavala-Castro, Jorge

    2012-01-01

    Rickettsia typhi: is an intracellular bacteria who causes murine typhus. His importance is reflected in the high frequency founding specific antibodies against Rickettsia typhi in several worldwide seroepidemiological studies, the seroprevalence ranging between 3-36%. Natural reservoirs of R. typhi are rats (some species belonging the Rattus Genus) and fleas (Xenopsylla cheopis) are his vector. This infection is associated with overcrowding, pollution and poor hygiene. Typically presents fever, headache, rash on trunk and extremities, in some cases may occur organ-specific complications, affecting liver, kidney, lung or brain. Initially the disease is very similar to other diseases, is very common to confuse the murine typhus with Dengue fever, therefore, ignorance of the disease is a factor related to complications or non-specific treatments for the resolution of this infection. This paper presents the most relevant information to consider about the rickettsiosis caused by Rickettsia typhi. PMID:24893060

  4. Endothelial cell promotion of early liver and pancreas development.

    Science.gov (United States)

    Freedman, Deborah A; Kashima, Yasushige; Zaret, Kenneth S

    2007-01-01

    Different steps of embryonic pancreas and liver development require inductive signals from endothelial cells. During liver development, interactions between newly specified hepatic endoderm cells and nascent endothelial cells are crucial for the endoderm's subsequent growth and morphogenesis into a liver bud. Reconstitution of endothelial cell stimulation of hepatic cell growth with embryonic tissue explants demonstrated that endothelial signalling occurs independent of the blood supply. During pancreas development, midgut endoderm interactions with aortic endothelial cells induce Ptf1a, a crucial pancreatic determinant. Endothelial cells also have a later effect on pancreas development, by promoting survival of the dorsal mesenchyme, which in turn produces factors supporting pancreatic endoderm. A major goal of our laboratory is to determine the endothelial-derived molecules involved in these inductive events. Our data show that cultured endothelial cells induce Ptf1a in dorsal endoderm explants lacking an endogenous vasculature. We are purifying endothelial cell line product(s) responsible for this effect. We are also identifying endothelial-responsive regulatory elements in genes such as Ptf1a by genetic mapping and chromatin-based assays. These latter approaches will allow us to track endothelial-responsive signal pathways from DNA targets within progenitor cells. The diversity of organogenic steps dependent upon endothelial cell signalling suggests that cross-regulation of tissue development with its vasculature is a general phenomenon.

  5. Transplantation of human neonatal foreskin stromal cells in ex vivo organotypic cultures of embryonic chick femurs

    DEFF Research Database (Denmark)

    Aldahmash, Abdullah; Vishnubalaji, Radhakrishnan

    2017-01-01

    NSSCs in ex vivo organotypic cultures of embryonic chick femurs. Isolated embryonic chick femurs (E10 and E11) were cultured for 10 days together with micro-mass cell pellets of hNSSCs, human umbilical vein endothelial cells (HUVEC) or a combination of the two cell types. Changes in femurs gross morphology...

  6. Defined MicroRNAs Induce Aspects of Maturation in Mouse and Human Embryonic-Stem-Cell-Derived Cardiomyocytes

    Directory of Open Access Journals (Sweden)

    Desy S. Lee

    2015-09-01

    Full Text Available Pluripotent-cell-derived cardiomyocytes have great potential for use in research and medicine, but limitations in their maturity currently constrain their usefulness. Here, we report a method for improving features of maturation in murine and human embryonic-stem-cell-derived cardiomyocytes (m/hESC-CMs. We found that coculturing m/hESC-CMs with endothelial cells improves their maturity and upregulates several microRNAs. Delivering four of these microRNAs, miR-125b-5p, miR-199a-5p, miR-221, and miR-222 (miR-combo, to m/hESC-CMs resulted in improved sarcomere alignment and calcium handling, a more negative resting membrane potential, and increased expression of cardiomyocyte maturation markers. Although this could not fully phenocopy all adult cardiomyocyte characteristics, these effects persisted for two months following delivery of miR-combo. A luciferase assay demonstrated that all four miRNAs target ErbB4, and siRNA knockdown of ErbB4 partially recapitulated the effects of miR-combo. In summary, a combination of miRNAs induced via endothelial coculture improved ESC-CM maturity, in part through suppression of ErbB4 signaling.

  7. Macropinocytosis is the Entry Mechanism of Amphotropic Murine Leukemia Virus

    DEFF Research Database (Denmark)

    Rasmussen, Izabela; Vilhardt, Frederik

    2015-01-01

    The entry mechanism of murine amphotropic retrovirus (A-MLV) has not been unambiguously determined. We show here that A-MLV does not internalize by caveolae or other pinocytic mechanism, but by macropinocytosis. Thus A-MLV infection of mouse embryonic fibroblasts deficient for caveolin or dynamin...

  8. Mechanically patterning the embryonic airway epithelium

    Science.gov (United States)

    Varner, Victor D.; Gleghorn, Jason P.; Miller, Erin; Radisky, Derek C.; Nelson, Celeste M.

    2015-01-01

    Collections of cells must be patterned spatially during embryonic development to generate the intricate architectures of mature tissues. In several cases, including the formation of the branched airways of the lung, reciprocal signaling between an epithelium and its surrounding mesenchyme helps generate these spatial patterns. Several molecular signals are thought to interact via reaction-diffusion kinetics to create distinct biochemical patterns, which act as molecular precursors to actual, physical patterns of biological structure and function. Here, however, we show that purely physical mechanisms can drive spatial patterning within embryonic epithelia. Specifically, we find that a growth-induced physical instability defines the relative locations of branches within the developing murine airway epithelium in the absence of mesenchyme. The dominant wavelength of this instability determines the branching pattern and is controlled by epithelial growth rates. These data suggest that physical mechanisms can create the biological patterns that underlie tissue morphogenesis in the embryo. PMID:26170292

  9. T-2毒素对小鼠胚胎干细胞线粒体功能的抑制作用%T-2 toxin inhibits mitochondrial function of differentiated murine embryonic stem cells

    Institute of Scientific and Technical Information of China (English)

    方海琴; 李利忠; 赵增明; 何俊; 赵君; 杨嵘; 耿雪; 彭双清

    2014-01-01

    目的:观察T-2毒素对小鼠胚胎干细胞(mESC)线粒体功能的毒性作用,探讨其胚胎毒性的可能作用靶点与作用机制。方法处于分化过程中的 mESC加入T-20.5μg·L-1分别作用24,72及120 h,同时设Trolox 200μmol·L-1预处理后30 min再加入T-2毒素0.5μg·L-1染毒72 h组。透射电子显微镜观察线粒体内结构;罗丹明123荧光探针法流式细胞术检测 mESC内线粒体膜电位,氧电极法检测线粒体呼吸速率,计算呼吸控制比,荧光素-荧光素酶发光法测定AT P合成酶活性。结果透射电镜观察可见,T-20.5μg·L-1作用72与120 h组 mESC内线粒体数量明显减少,结构变形,线粒体中少见或缺少完整的嵴,与正常对照组相比,mESC内线粒体呼吸控制比分别下降49.5%和55.1%(P<0.05),ATP合成酶活性分别下降84.9%和89.3%(P<0.05),mESC线粒体膜电位下降23.2%和35.2%(P<0.05)。Trolox预处理可以改善T-2毒素对上述线粒体功能指标的抑制作用。结论 T-2毒素可降低mESC的线粒体功能,进而抑制 mESC的分化能力,可能是其胚胎发育毒性的作用机制之一。%OBJECTIVE ToexplorethepossiblemechanismoractiontargetsofT-2toxinembryo toxicity by observing the effect of T-2 toxin on mitochondrial function of differentiated murine e mbryonic stemcells(mESCs).METHODS Duringdifferentiationat24,72and120h,ESCswereexposedto T-2 toxin 0.5 μg·L-1 .Meanwhile,mESCs were pre-treated with antioxidant Trolox (200 μmol·L-1 )for 30 min and exposed to T-2 toxin (0.5 μg·L-1 )for 72 h.The mitochondrial ultrasture of differentiated mESCs was observed under a transi mission electrical microscope (TEM).The differentiated ESC mito-chondrial function,including respiratory control ratio (RCR),ATP synthase activity and mitochondrial membranepotential(MMP),wasmeasuredat144hafterdifferentiation.RESULTS Significant decrease of the mitochondrial number

  10. Endothelial cell-driven regulation of CD9 or motility-related protein-1 expression in multiple myeloma cells within the murine 5T33MM model and myeloma patients

    DEFF Research Database (Denmark)

    De Bruyne, E; Levin Andersen, Thomas; De Raeve, H;

    2006-01-01

    The cell surface expression of CD9, a glycoprotein of the tetraspanin family influencing several processes including cell motility and metastasis, inversely correlates with progression in several solid tumors. In the present work, we studied the expression and role of CD9 in multiple myeloma (MM)...... interaction of the cells with BMEC and that CD9 is involved in transendothelial invasion, thus possibly mediating homing and/or spreading of the MM cells........ These findings were also confirmed by immunohistochemistry in MM patients. Neutralizing anti-CD9 antibodies inhibited transendothelial invasion of CD9-expressing human MM5.1 and murine 5T33MMvivo cells. In conclusion, we provide evidence that CD9 expression by the MM cells is upregulated in vivo by close...

  11. Research on Growth Behavior of Embryos for Bovine and Murine on Primary Murine Embryos Fibroblast Cell Feeder Layer

    Institute of Scientific and Technical Information of China (English)

    AN Li-long; XIAO Mei; FENG Xiu-Liang; DOU Zhong-ying; QIU Huai; YANG Qi; LEI An-min; YANG Chun-rong; GAO Zhi-min

    2002-01-01

    The difference in growth behavior between bovine embryos and murine embryos was studied on PMEF(primary murine embryos fibroblast)feeder layer. The results showed as follows: With embryos having attached, bovine embryonic trophoblast formed a transparent membranous structure covering on inner cell mass (ICM), however, murine embryonic trophoblast formed disc structure. Bovine embryos formed four kinds of ICM colonies with different morphology including the mass-like, the net-like, the stream-like and the mixture-like colonies. Compared with Murine ICM, the bovine ICM grew more fast. So, the bovine ICM was passaged at first after a culture of approximately 5 - 6 days in vitro, but murine ICM was passaged at first after an attachment of 3 - 4 days on PMEF feeder layer. The mixture colonies of bovine ICM differentiated very early, while the others differentiated very late. Most ICM-like mass of Bovine grew in a defined spot, but bovine ICMs like stream and ICMs like net proliferated fast and dispersed quickly. We found that the single blastomeres derived from late bovine morula and late murine morula formed sub-blastophere; moreover, the bovine ICM cell would differentiate rapidly if the trophoblast was removed.

  12. Efficient engineering of vascularized ectopic bone from human embryonic stem cell-derived mesenchymal stem cells.

    Science.gov (United States)

    Domev, Hagit; Amit, Michal; Laevsky, Ilana; Dar, Ayelet; Itskovitz-Eldor, Joseph

    2012-11-01

    Human mesenchymal stem cells (hMSCs) can be derived from various adult and fetal tissues. However, the quality of tissues for the isolation of adult and fetal hMSCs is donor dependent with a nonreproducible yield. In addition, tissue engineering and cell therapy require large-scale production of a pure population of lineage-restricted stem cells that can be easily induced to differentiate into a specific cell type. Therefore, human embryonic stem cells (hESCs) can provide an alternative, plentiful source for generation of reproducible hMSCs. We have developed efficient differentiation protocols for derivation of hMSCs from hESCs, including coculture with murine OP9 stromal cells and feeder layer-free system. Our protocols have resulted in the generation of up to 49% of hMSCs, which expressed CD105, CD90, CD29, and CD44. The hMSCs exhibited high adipogenic, chondrocytic, and osteogenic differentiation in vitro. The latter correlated with osteocalcin secretion and vascular endothelial growth factor (VEGF) production by the differentiating hMSCs. hMSC-derived osteoblasts further differentiated and formed ectopic bone in vivo, and induced the formation of blood vessels in Matrigel implants. Our protocol enables generation of a purified population of hESC-derived MSCs, with the potential of differentiating into several mesodermal lineages, and particularly into vasculogenesis-inducing osteoblasts, which can contribute to the development of bone repair protocols.

  13. The Preliminary Experimental Study of Induced Differentiation of Embryonic Stem Cells into Corneal Epithelial Cells

    Institute of Scientific and Technical Information of China (English)

    Ling Yu; Jian Ge; Zhichong Wang; Bing Huang; Keming Yu; Chongde Long; Xigu Chen

    2001-01-01

    Purpose:To study preliminarily induced differentiation of embryonic stem cells intocorneal epithelial cells in vitro.Methods: Murine embryonic stem cells were co-cultured with Rabbit limbal cornealepithelial cells in Transwell system to induce differentiation. Mophological andimmunohistochemical examination were implemented.Results: The induced cells from embryonic stem cells have an epithelial appearance.The cells formed a network and were confluent into film gradually after beingco-cultured with rabbit limbal corneal epithelial cells for 24 ~ 96 hours. The cells rangedmosaic structure and localized together with clear rim. Most of the cells showedpolygonal appearance. Transmission electron microscope showed lots of microvilli on thesurface of induced cells and tight junctions between them. These epithelial-like cellsexpressed the corneal epithelial cell specific marker cytokeratin3/cytokeratinl2.Conclusion: The potential mechanism of the differentiation of murine embryonic stemcells into corneal epithelial cells induced by limbal corneal epithelial cell-derivedinducing activity is to be further verified.

  14. Angiogenic and osteogenic regeneration in rats via calcium phosphate scaffold and endothelial cell co-culture with human bone marrow mesenchymal stem cells (MSCs), human umbilical cord MSCs, human induced pluripotent stem cell-derived MSCs and human embryonic stem cell-derived MSCs.

    Science.gov (United States)

    Chen, Wenchuan; Liu, Xian; Chen, Qianmin; Bao, Chongyun; Zhao, Liang; Zhu, Zhimin; Xu, Hockin H K

    2017-01-18

    Angiogenesis is a limiting factor in regenerating large bone defects. The objective of this study was to investigate angiogenic and osteogenic effects of co-culture on calcium phosphate cement (CPC) scaffold using human umbilical vein endothelial cells (hUVECs) and mesenchymal stem cells (MSCs) from different origins for the first time. hUVECs were co-cultured with four types of cell: human umbilical cord MSCs (hUCMSCs), human bone marrow MSCs (hBMSCs) and MSCs from induced pluripotent stem cells (hiPSC-MSCs) and embryonic stem cells (hESC-MSCs). Constructs were implanted in 8 mm cranial defects of rats for 12 weeks. CPC without cells served as control 1. CPC with hBMSCs served as control 2. Microcapillary-like structures were successfully formed on CPC in vitro in all four co-cultured groups. Microcapillary lengths increased with time (p cultured cells increased with time (p cultured groups were much greater than controls (p animal study. hUVECs co-cultured with hUCMSCs, hiPSC-MSCs and hESC-MSCs achieved new bone and vessel density similar to hUVECs co-cultured with hBMSCs (p > 0.1). Therefore, hUCMSCs, hiPSC-MSCs and hESC-MSCs could serve as alternative cell sources to hBMSCs, which require an invasive procedure to harvest. In conclusion, this study showed for the first time that co-cultures of hUVECs with hUCMSCs, hiPSC-MSCs, hESC-MSCs and hBMSCs delivered via CPC scaffold achieved excellent osteogenic and angiogenic capabilities in vivo. The novel co-culture constructs are promising for bone reconstruction with improved angiogenesis for craniofacial/orthopaedic applications. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  15. Development of Endothelial-Specific Single Inducible Lentiviral Vectors for Genetic Engineering of Endothelial Progenitor Cells.

    Science.gov (United States)

    Yang, Guanghua; Kramer, M Gabriela; Fernandez-Ruiz, Veronica; Kawa, Milosz P; Huang, Xin; Liu, Zhongmin; Prieto, Jesus; Qian, Cheng

    2015-11-27

    Endothelial progenitor cells (EPC) are able to migrate to tumor vasculature. These cells, if genetically modified, can be used as vehicles to deliver toxic material to, or express anticancer proteins in tumor. To test this hypothesis, we developed several single, endothelial-specific, and doxycycline-inducible self-inactivating (SIN) lentiviral vectors. Two distinct expression cassettes were inserted into a SIN-vector: one controlled by an endothelial lineage-specific, murine vascular endothelial cadherin (mVEcad) promoter for the expression of a transactivator, rtTA2S-M2; and the other driven by an inducible promoter, TREalb, for a firefly luciferase reporter gene. We compared the expression levels of luciferase in different vector constructs, containing either the same or opposite orientation with respect to the vector sequence. The results showed that the vector with these two expression cassettes placed in opposite directions was optimal, characterized by a robust induction of the transgene expression (17.7- to 73-fold) in the presence of doxycycline in several endothelial cell lines, but without leakiness when uninduced. In conclusion, an endothelial lineage-specific single inducible SIN lentiviral vector has been developed. Such a lentiviral vector can be used to endow endothelial progenitor cells with anti-tumor properties.

  16. Nitric Oxide Synthase-3 Promotes Embryonic Development of Atrioventricular Valves

    OpenAIRE

    Yin Liu; Xiangru Lu; Fu-Li Xiang; Man Lu; Qingping Feng

    2013-01-01

    Nitric oxide synthase-3 (NOS3) has recently been shown to promote endothelial-to-mesenchymal transition (EndMT) in the developing atrioventricular (AV) canal. The present study was aimed to investigate the role of NOS3 in embryonic development of AV valves. We hypothesized that NOS3 promotes embryonic development of AV valves via EndMT. To test this hypothesis, morphological and functional analysis of AV valves were performed in wild-type (WT) and NOS3(-/-) mice at postnatal day 0. Our data s...

  17. Type 1 and 3 inositol trisphosphate receptors are required for extra-embryonic vascular development.

    Science.gov (United States)

    Uchida, Keiko; Nakazawa, Maki; Yamagishi, Chihiro; Mikoshiba, Katsuhiko; Yamagishi, Hiroyuki

    2016-10-01

    The embryonic-maternal interface of the placental labyrinth, allantois, and yolk sac are vital during embryogenesis; however, the precise mechanism underlying the vascularization of these structures remains unknown. Herein we focus on the role of inositol 1,4,5-trisphosphate (IP3) receptors (IP3R), which are intracellular Ca(2+) release channels, in placentation. Double knockout (DKO) of type 1 and 3 IP3Rs (IP3R1 and IP3R3, respectively) in mice resulted in embryonic lethality around embryonic day (E) 11.5. Because IP3R1 and IP3R3 were co-expressed in endothelial cells in the labyrinth, allantois, and yolk sac, we investigated extra-embryonic vascular development in IP3R1- and IP3R3-DKO mice. The formation of chorionic plates and yolk sac vessels seemed dysregulated around the timing of the chorio-allantoic attachment, immediately followed by the disorganization of allantoic vessels, the decreased expression of the spongiotrophoblast cell marker Tpbpa and the growth retardation of the embryos in DKO mice. Fluorescent immunohistochemistry demonstrated downregulation of a vascular endothelial marker, CD31, in labyrinth embryonic vessels and poor elongation of extra-embryonic mesoderm into the labyrinth layer in DKO placenta, whereas the branching of the DKO chorionic trophoblast was initiated. In addition, allantoic and yolk sac vessels in extra-embryonic tissues were less remodeled in DKO mice. In vitro endothelial cord formation and migration activities of cultured vascular endothelial cells derived from human umbilical vein were downregulated under the inhibition of IP3R. Our results suggest that IP3R1 and IP3R3 are required for extra-embryonic vascularization in the placenta, allantois, and yolk sac. This is the first demonstration of the essential role of IP3/IP3Rs signaling in the development of the vasculature at the embryonic-maternal interface.

  18. 人主动脉-性腺-中肾区基质细胞诱导胚胎干细胞分化为造血干细胞及体内造血重建%Differentiation of murine embryonic stem cells into hematopoietic stem cells induced by stromal cells in human aorta-gonad-mesonephros region and hematopoietic reconstitution in vivo

    Institute of Scientific and Technical Information of China (English)

    蔡耘; 张绪超; 陈惠芹; 黄绍良

    2011-01-01

    BACKGROUND: Up to now it has been confirmed that under proper conditions of hematopoietic growth factors, feeder layers of stromal cells from hematopoietic niches and their conditioned media, embryonic stem cells (ESCs) can be induced into hematopoietic stem cells (HSCs). OBJECTIVE: To direct murine ESCs into HSCs in vitro by the support of human aorta-gonad-mesonephros (AGM) region stromal cells, and to compare the function of hematopoietic reconstitution in vivo by different routes of HSCs transplantation in mice. METHODS: Firstly, E14 murine ESCs were induced into embryoid body (EB). Then the cells from EB were further co-cultured with human AGM region stromal cells in Transwell non-contact system for 6 days. The induced EB cells were collected for Sca-1+c-Kit+ cells analysis by flow cytometry, checked for teratoma formation and transplanted to BALB/C female mice conditioned with lethal dose 60Co ?-ray irradiation. The recipient mice were divided into four groups at random, including intravenous injection group, bilateral tibia intra-bone marrow (IBM) injection group, irradiation control group and normal control group. The survival rates, reconstitution of hematopoietic and engraftment of donor cells of different groups were monitored. RESULTS AND CONCLUSION: Sca-1+c-Kit+ cells in EB cells after co-cultured with human AGM region stromal cells accounted for (13.12±1.30)%. Teratoma could be detected in NOD-SCID mice after subcutaneous injection of EB cells co-cultured with human AGM region stromal cells, while there was no teratoma in the mice after IBM injection of that cells. The recipients in intravenous injection group all died. The survival rate was 55.6% in IBM group, in which the peripheral blood cell count was near to the normal at day 21 after transplantation and Sry gene copies from donor could be detected. It suggested that feeder cells from human AGM region can induce directed differentiation of murine ESCs into HSCs which can reconstruct

  19. OK432优化的内皮细胞疫苗抗小鼠乳腺癌作用研究%Anti-tumor effects of OK432 optimized umbilical vein endothelial cell vaccine in murine breast cancer

    Institute of Scientific and Technical Information of China (English)

    徐茂磊; 周玲; 杨小平

    2014-01-01

    目的:探讨 OK432优化的人脐静脉内皮细胞( HU-VECs)疫苗对小鼠EAC乳腺癌的生长抑制作用。方法体外培养HUVECs,与佐剂OK432混合,制备HUVECs-OK432疫苗,以小鼠 EAC 乳腺癌皮下移植瘤模型考查 HUVECs-OK432疫苗的抗肿瘤效应,并通过ELISA、脾细胞增殖及细胞毒性T淋巴细胞( CTL)杀伤实验检测疫苗免疫后体液及细胞免疫应答水平。结果在预防性免疫中, HUVECs-OK432疫苗可以明显抑制EAC乳腺癌生长;HUVECs-OK432疫苗诱导小鼠产生了高滴度的特异性 HUVEC 抗体;HU-VECs-OK432疫苗能有效刺激免疫小鼠脾淋巴细胞的增殖;HUVECs-OK432组小鼠脾细胞诱导产生了明显的靶向HU-VEC细胞的CTL杀伤作用。结论 HUVECs-OK432疫苗可以有效诱导机体产生靶向HUVEC的特异性体液及细胞免疫应答,从而有效抑制了小鼠EAC乳腺癌的生长。%Aim To investigate the anti-EAC breast cancer effects of viable human umbilical vein endothe-lial cells ( HUVECs) vaccine. Methods Subconflu-ent HUVECs were mixed with OK432 to prepare HU-VECs-OK432 vaccine, and the anti-tumor efficacy of HUVECs-OK432 was investigated using a subcutaneous tumor model of EAC breast cancer. ELISA, splenic lymphocyte proliferation assay and cytotoxic T lympho-cytes ( CTL ) killing assay were adopted to detect the humoral and cellular immune responses after HUVECs-OK432 immunization. Results HUVECs-OK432 im-munization significantly inhibited the growth of EAC tumor in mice in the prophylactic procedures. High ti-ter of anti-HUVEC antibody was elicited by HUVECs-OK432 immunization. The proliferation activity of splenocytes from mice immunized with HUVECs-OK432 was significantly increased. T lymphocytes iso-lated from HUVECs-OK432-immunized mice were dose dependently killing HUVECs in vitro. Conclusion Strong humoral and cellular immune responses targeting HUVEC are elicited by HUVECs-OK432 immuniza-tion, which results in a significant inhibition on the growth

  20. CD13 and ROR2 Permit Isolation of Highly Enriched Cardiac Mesoderm from Differentiating Human Embryonic Stem Cells.

    Science.gov (United States)

    Skelton, Rhys J P; Brady, Bevin; Khoja, Suhail; Sahoo, Debashis; Engel, James; Arasaratnam, Deevina; Saleh, Kholoud K; Abilez, Oscar J; Zhao, Peng; Stanley, Edouard G; Elefanty, Andrew G; Kwon, Murray; Elliott, David A; Ardehali, Reza

    2016-01-12

    The generation of tissue-specific cell types from human embryonic stem cells (hESCs) is critical for the development of future stem cell-based regenerative therapies. Here, we identify CD13 and ROR2 as cell-surface markers capable of selecting early cardiac mesoderm emerging during hESC differentiation. We demonstrate that the CD13+/ROR2+ population encompasses pre-cardiac mesoderm, which efficiently differentiates to all major cardiovascular lineages. We determined the engraftment potential of CD13+/ROR2+ in small (murine) and large (porcine) animal models, and demonstrated that CD13+/ROR2+ progenitors have the capacity to differentiate toward cardiomyocytes, fibroblasts, smooth muscle, and endothelial cells in vivo. Collectively, our data show that CD13 and ROR2 identify a cardiac lineage precursor pool that is capable of successful engraftment into the porcine heart. These markers represent valuable tools for further dissection of early human cardiac differentiation, and will enable a detailed assessment of human pluripotent stem cell-derived cardiac lineage cells for potential clinical applications.

  1. CD13 and ROR2 Permit Isolation of Highly Enriched Cardiac Mesoderm from Differentiating Human Embryonic Stem Cells

    Directory of Open Access Journals (Sweden)

    Rhys J.P. Skelton

    2016-01-01

    Full Text Available The generation of tissue-specific cell types from human embryonic stem cells (hESCs is critical for the development of future stem cell-based regenerative therapies. Here, we identify CD13 and ROR2 as cell-surface markers capable of selecting early cardiac mesoderm emerging during hESC differentiation. We demonstrate that the CD13+/ROR2+ population encompasses pre-cardiac mesoderm, which efficiently differentiates to all major cardiovascular lineages. We determined the engraftment potential of CD13+/ROR2+ in small (murine and large (porcine animal models, and demonstrated that CD13+/ROR2+ progenitors have the capacity to differentiate toward cardiomyocytes, fibroblasts, smooth muscle, and endothelial cells in vivo. Collectively, our data show that CD13 and ROR2 identify a cardiac lineage precursor pool that is capable of successful engraftment into the porcine heart. These markers represent valuable tools for further dissection of early human cardiac differentiation, and will enable a detailed assessment of human pluripotent stem cell-derived cardiac lineage cells for potential clinical applications.

  2. Global phosphoproteome profiling reveals unanticipated networks responsive to cisplatin treatment of embryonic stem cells

    DEFF Research Database (Denmark)

    Pines, Alex; Kelstrup, Christian D; Vrouwe, Mischa G

    2011-01-01

    (stable isotope labeling by amino acids in cell culture)-labeled murine embryonic stem cells with the anticancer drug cisplatin. Network and pathway analyses indicated that processes related to the DNA damage response and cytoskeleton organization were significantly affected. Although the ATM (ataxia...

  3. Establishment of Murine Embryonic Stem Cell Line Carrying Enhanced Green Fluorescence Protein and its Differentiation into Cardiomyocyte-like Cells in vitro%建立绿色荧光蛋白标记的小鼠胚胎干细胞系及向心肌样细胞的分化

    Institute of Scientific and Technical Information of China (English)

    姜祖韵; 袁毅君; 陈良标; 陆永良; 姚行; 戴利成; 张铭

    2004-01-01

    The availability of EGFP ES cell D3 lines provided a tractable model to study cell differentiation and tissue generation in vivo and in vitro. Plasmid pEGFP N2 was introduced into the murine embryonic stem cell D3 by standard calcium phosphate precipitation. Transfected clones were screened out under the fluorescence microscope at the 488 nm emission light in the presence of G418. Strong fluorescent EGFP clones were singly picked out and further proliferated on a feeder layer of mitomycin-C treated mouse embryonic fibroblasts. One line of EGFP ES D3 cells subcultured twenty passages and still carried the EGFP DNA without the selecting pressure. It indicated that the gene might integrate into the ES genome or still dissociated in the cytoplasm. PCR analysis for EGFP DNA showed that undifferentiated EGFP ES cells at passage 8 and 18 carried the EGFP gene. Alkaline phosphatase staining,embryoid body and teratoma formation were performed to analyze the differentiation status and potential of the EGFP ES D3 cells. The cells derived from embryoid body were able to differentiate into beating cardiomyocytes with green fluorescence clearly observable under the confocal laser scanning microscopy. 30% ~ 40% of cells from embryoid bodies were capable to differentiate into cardiomyocyte-like cells, and it appeared lower than the non-transfected ES D3 cells, which could be 60% ~ 70% under the same conditions. The mechanism was currently unknown. Immunocytochemistry staining indicated that the contracting cells were cardiomyocytes based on the presence of cardiac specific molecular marker cTnT. Results showed that the stable EGFP positive ES cell line retained the typical characteristics of ES cells and possessed the pluripotential to differentiate into beating myocytes in vitro.The EGFP transfected cells stably yielding bright green fluorescence in real time and in situ rendered it was a powerful tool in cell transplantation and tissue engineering.%带有GFP基因的ES D3

  4. Compatibility of embryonic stem cells with biomaterials.

    Science.gov (United States)

    Handschel, Jörg; Berr, Karin; Depprich, Rita; Naujoks, Christian; Kübler, Norbert R; Meyer, Ulrich; Ommerborn, Michelle; Lammers, Lydia

    2009-05-01

    Periodontal bone defects and atrophy of the jaws in an aging population are of special concern. Tissue engineering using embryonic stem cells (ESCs) and biomaterials may offer new therapeutic options. The purpose of this study is to evaluate the compatibility of ESCs with biomaterials and the influence of biomaterials on the osteogenic gene expression profile.Therefore, ESCs are cultured with various biomaterials. The cytocompatibility of murine ESCs is measured regarding the proliferation of the cells on the materials by CyQUANT assay, the morphology by scanning electron microscopy, and the influence on the gene expression by real time PCR.The results show that insoluble collagenous bone matrix, followed by beta-tricalciumphosphate, is most suitable for bone tissue engineering regarding cell proliferation, and phenotype. The gene expression analysis indicates that biomaterials do influence the gene expression of ESCs.Our results provide new insight into the cytocompatibility of ESCs on different scaffolds.

  5. Transplantation of mammalian embryonic stem cells and their derivatives to avian embryos.

    Science.gov (United States)

    Goldstein, Ronald S

    2010-09-01

    Xenografting of normal and transformed mammalian tissues and cells to chick embryos has been performed for almost 100 years. Embryonic stem cells, derived more than 25 years ago from murine, and more than 10 years ago from human blastocysts, have transformed many fields of biological research. There is a growing body of studies combining these two widely-used experimental systems. This review surveys those reports in which murine or human embryonic stem cells, or differentiated derivatives of these pluripotent stem cells, were transplanted to embryonated chick eggs. Many of these studies have utilized the unique characteristics of both experimental models to obtain answers to developmental questions that are difficult or impossible to approach with xenografting to adult rodents or tissue culture-only techniques.

  6. Research on Isolation and Clone of Embryonic Stem Cell-Like in Bovine

    Institute of Scientific and Technical Information of China (English)

    AN Li-long; YANG Qi; XIAO Mei; FENG Xiu-Liang; YANG Chun-rong; LEI An-min; GAO Zhi-min; DOU Zhong-ying; QIU Huai

    2002-01-01

    Bovine embryonic stem cell would be invaluable for researching the aspect of animal cloning, production transgenic animal and discussion of gene function in vitro. With the object of establishing an effective culture system for isolation and clone of bovine pluripotent stem cell, we cultured bovine embryos and mouse embryos including morula blastula and hatached blastula and obtained animal ICM on Primary marine embryonic fibroblast (Primary murine embryonic fibroblast, PMEF) feeder layer with tissue medium(DMEM supplemented with 15ml/100ml NBS ,0.1μmol/L Na2SeO3, 0. 1mmol/L β-mercaptoethanol, 1 000ng/ml LIF,10 ng/ml IGF, 1mmol/L necessary amino acid and 1mmol/L L-glutamine), then, we obtained mouse ICM and bovine ICM. Moreover, we isolated and cloned the 6 passage bovine ES like cells(12 cell lines) and 9 passage marine ES like cells (52 cell lines) deriving from bovine ICM and murine ICM respectively on the feeder layer of PMEF by disaggregating ICM and ES cell clones of bovine and murine into smaller clumps through digesting with 0. 125g/100ml trypsin and 0.02g/100ml EDTA and scattering with a glass needle. The pluripotency of both murine and bovine ES like cells was identified with morphological character, histochemistry identification, karyotype analysis and differentiation of ES cells in vitro or in vivo. This result showed that bovine embryonic stem cell and murine embryonic stem cell had developmental pluripotency.

  7. Porcine embryonic stem cells

    DEFF Research Database (Denmark)

    Hall, Vanessa Jane

    2008-01-01

    The development of porcine embryonic stem cell lines (pESC) has received renewed interest given the advances being made in the production of immunocompatible transgenic pigs. However, difficulties are evident in the production of pESCs in-vitro. This may largely be attributable to differences...

  8. Efficient Differentiation of Embryonic Stem Cells into Neurons in Glial Cell-conditioned Medium under Attaching Conditions

    Institute of Scientific and Technical Information of China (English)

    Hai-Bin TIAN; Zeng-Liang BAI; Hong WANG; Jian-Quan CHEN; Guo-Xiang CHENG

    2005-01-01

    Embryonic stem (ES) cells can differentiate into neurons in vitro, which provides hope for the treatment of some neurodegenerative diseases through cell transplantation. However, it remains a challenge to efficiently induce ES cells to differentiate into neurons. Here, we show that murine ES cells can efficiently differentiate into neurons when cultured in glial cell- conditioned medium (GCM) under attaching conditions without the formation of embryoid bodies. In comparison with murine embryonic fibroblast-conditioned medium, we found that GCM has a positive effect on limiting the generation of non-neuronal cells, such as astrocytes. In addition, compared with suspension conditions, attaching conditions delay the differentiation process of ES cells.

  9. Quantum dot imaging for embryonic stem cells

    Directory of Open Access Journals (Sweden)

    Gambhir Sanjiv S

    2007-10-01

    Full Text Available Abstract Background Semiconductor quantum dots (QDs hold increasing potential for cellular imaging both in vitro and in vivo. In this report, we aimed to evaluate in vivo multiplex imaging of mouse embryonic stem (ES cells labeled with Qtracker delivered quantum dots (QDs. Results Murine embryonic stem (ES cells were labeled with six different QDs using Qtracker. ES cell viability, proliferation, and differentiation were not adversely affected by QDs compared with non-labeled control cells (P = NS. Afterward, labeled ES cells were injected subcutaneously onto the backs of athymic nude mice. These labeled ES cells could be imaged with good contrast with one single excitation wavelength. With the same excitation wavelength, the signal intensity, defined as (total signal-background/exposure time in millisecond was 11 ± 2 for cells labeled with QD 525, 12 ± 9 for QD 565, 176 ± 81 for QD 605, 176 ± 136 for QD 655, 167 ± 104 for QD 705, and 1,713 ± 482 for QD 800. Finally, we have shown that QD 800 offers greater fluorescent intensity than the other QDs tested. Conclusion In summary, this is the first demonstration of in vivo multiplex imaging of mouse ES cells labeled QDs. Upon further improvements, QDs will have a greater potential for tracking stem cells within deep tissues. These results provide a promising tool for imaging stem cell therapy non-invasively in vivo.

  10. An ES-Like pluripotent state in FGF-dependent murine iPS cells

    NARCIS (Netherlands)

    B. di Stefano (Bruno); C. Buecker (Christa); F. Ungaro (Federica); A. Prigione (Alessandro); H.H. Chen; M. Welling (Maaike); M. Eijpe (Maureen); G. Mostoslavsky (Gustavo); P. Tesar (Paul); J. Adjaye (James); N. Geijsen (Niels); V. Broccoli (Vania)

    2010-01-01

    textabstractRecent data demonstrates that stem cells can exist in two morphologically, molecularly and functionally distinct pluripotent states; a naïve LIF-dependent pluripotent state which is represented by murine embryonic stem cells (mESCs) and an FGFdependent primed pluripotent state represente

  11. A murine ESC-like state facilitates transgenesis and homologous recombination in human pluripotent stem cells

    NARCIS (Netherlands)

    C. Buecker (Christa); H.H. Chen; J.M. Polo (Jose); L. Daheron (Laurence); L. Bu (Lei); T.S. Barakat (Tahsin Stefan); P. Okwieka (Patricia); A. Porter (Andrew); J.H. Gribnau (Joost); K. Hochedlinger (Konrad); N. Geijsen (Niels)

    2010-01-01

    textabstractMurine pluripotent stem cells can exist in two functionally distinct states, LIF-dependent embryonic stem cells (ESCs) and bFGF-dependent epiblast stem cells (EpiSCs). However, human pluripotent cells so far seemed to assume only an epiblast-like state. Here we demonstrate that human iPS

  12. A Murine ESC-like State Facilitates Transgenesis and Homologous Recombination in Human Pluripotent Stem Cells

    NARCIS (Netherlands)

    Buecker, Christa; Chen, Hsu-Hsin; Polo, Jose Maria; Daheron, Laurence; Bu, Lei; Barakat, Tahsin Stefan; Okwieka, Patricia; Porter, Andrew; Gribnau, Joost; Hochedlinger, Konrad; Geijsen, Niels

    2010-01-01

    Murine pluripotent stem cells can exist in two functionally distinct states, LIF-dependent embryonic stem cells (ESCs) and bFGF-dependent epiblast stem cells (EpiSCs). However, human pluripotent cells so far seemed to assume only an epiblast-like state. Here we demonstrate that human iPSC reprogramm

  13. A murine ESC-like state facilitates transgenesis and homologous recombination in human pluripotent stem cells

    NARCIS (Netherlands)

    C. Buecker (Christa); H.H. Chen; J.M. Polo (Jose); L. Daheron (Laurence); L. Bu (Lei); T.S. Barakat (Tahsin Stefan); P. Okwieka (Patricia); A. Porter (Andrew); J.H. Gribnau (Joost); K. Hochedlinger (Konrad); N. Geijsen (Niels)

    2010-01-01

    textabstractMurine pluripotent stem cells can exist in two functionally distinct states, LIF-dependent embryonic stem cells (ESCs) and bFGF-dependent epiblast stem cells (EpiSCs). However, human pluripotent cells so far seemed to assume only an epiblast-like state. Here we demonstrate that human iPS

  14. A Murine ESC-like State Facilitates Transgenesis and Homologous Recombination in Human Pluripotent Stem Cells

    NARCIS (Netherlands)

    Buecker, Christa; Chen, Hsu-Hsin; Polo, Jose Maria; Daheron, Laurence; Bu, Lei; Barakat, Tahsin Stefan; Okwieka, Patricia; Porter, Andrew; Gribnau, Joost; Hochedlinger, Konrad; Geijsen, Niels

    2010-01-01

    Murine pluripotent stem cells can exist in two functionally distinct states, LIF-dependent embryonic stem cells (ESCs) and bFGF-dependent epiblast stem cells (EpiSCs). However, human pluripotent cells so far seemed to assume only an epiblast-like state. Here we demonstrate that human iPSC reprogramm

  15. Isotype specific immune responses in murine experimental toxocariasis

    Directory of Open Access Journals (Sweden)

    Cuéllar C

    2001-01-01

    Full Text Available In this work, a murine experimental model of toxocariasis has been developed in BALB/c, C57BL/10 and C3H murine strains orally inoculated with 4,000 Toxocara canis embryonated eggs, in order to investigate the isotype-specific immune responses against excretory-secretory antigens from larvae. T. canis specific IgG+M, IgM, IgG, IgA, IgG1, IgG2a and IgG3 were tested by ELISA. The dynamics of the specific immunoglobulins (IgG+IgM production showed a contrasting profile regarding the murine strain. Conversely to the results obtained with the IgM isotype, the IgG antibody class showed similar patterns to those obtained with IgG+IgM antibodies, only in the case of the BALB/c strain, being different and much higher than the obtained with IgG+IgM antibodies, when the C3H murine strain was used. The antibodies IgG+IgM tested in BALB/c and C57BL/10 were both of the IgM and IgG isotypes. Conversely, in the C3H strain only IgG specific antibody levels were detected. The IgG1 subclass responses showed a similar profile in the three murine strains studied, with high values in BALB/c, as in the case of the IgG responses.

  16. Establishment and characterization of two new human embryonic stem cell lines, SYSU-1 and SYSU-2

    Institute of Scientific and Technical Information of China (English)

    HUANG Guo; Andy Peng Xiang; LI Wei-qiang; CHEN Rui; CHEN Zhen-guang; ZHANG Xiu-ming; MAO Fu-xiang; HUANG Shao-liang; LI Shu-nong; Bruce T Lahn

    2007-01-01

    Background Human embryonic stem cells can propagate indefinitely in vitro and are able to differentiate into derivatives of all three embryonic germ layers. The excitement surrounding human embryonic stem cells lies largely in their potential to produce specialized cells that can be used for transplant therapies. However, further investigation requires additional cell lines with varying genetic background. Therefore, efforts to derive and establish more human embryonic stem cell lines are highly warranted.Methods Surplus embryos (blastocysts) from donors were used to isolate the inner cell mass by immunosurgery. All cells were cultured continuously on irradiated murine embryonic fibroblasts feed layer and likely human embryonic stem cell colonies were subsequently characterized by cell surface marker staining, karyotyping and teratoma formation.Results Two human embryonic stem cell lines (SYSU-1 and SYSU-2) were established from surplus embryos. The two lines express several pluripotency markers including alkaline phosphatase, SSEA- 4, Tra-1-60, Oct-4, Nanog and Rex-1.They remain in undifferentiated state with normal karyotype after prolonged passages and can form embryoid bodies in vitro and teratoma in vivo.Conclusion Two new human embryonic stem cell lines have been established from surplus embryos. They can be used to understand selfrenewal and differentiating mechanisms and provide more choices for regenerative medicine.

  17. [Vascular endothelial Barrier Function].

    Science.gov (United States)

    Ivanov, A N; Puchinyan, D M; Norkin, I A

    2015-01-01

    Endothelium is an important regulator of selective permeability of the vascular wall for different molecules and cells. This review summarizes current data on endothelial barrier function. Endothelial glycocalyx structure, its function and role in the molecular transport and leukocytes migration across the endothelial barrier are discussed. The mechanisms of transcellular transport of macromolecules and cell migration through endothelial cells are reviewed. Special section of this article addresses the structure and function of tight and adherens endothelial junction, as well as their importance for the regulation of paracellular transport across the endothelial barrier. Particular attention is paid to the signaling mechanism of endothelial barrier function regulation and the factors that influence on the vascular permeability.

  18. 小鼠胚胎干细胞条件培养基体外促进人角膜内皮细胞增殖的研究%Proliferation in vitro of human corneal endothelial cells promoted by mouse embryonic stem cell conditioned medium

    Institute of Scientific and Technical Information of China (English)

    鹿晓燕

    2016-01-01

    目的 观察小鼠胚胎干细胞条件培养基(mouse embryonic stem cells conditioned medium,ESC-CM)是否可以在体外促进人角膜内皮细胞(human corneal endothelial cells,HCECs)的增殖.方法 利用角膜内皮后弹力层组织块方法进行原代培养P0 HCECs.实验组使用含有25% ESC-CM的培养液进行培养,对照组使用普通角膜内皮细胞培养液(corneal endothelium medium,CEM)进行培养.倒置相差显微镜、反转录聚合酶链反应(reverse-transcription polymerase chain reaction,RT-PCR)鉴定HCECs;倒置相差显微镜观察细胞的形态及萌出时间;Western Blot、免疫组织化学法观察HCECs的泵相关功能蛋白(zona occludens protein-1,ZO-1)及Na+-K+-ATP酶的表达.Giemsa染色细胞克隆实验、免疫组织化学及流式细胞学检测Ki67阳性率的方法比较HCECs的增殖能力;流式细胞学方法检查细胞周期及细胞凋亡情况.Western Blot和免疫组织化学方法检测细胞周期负性调节蛋白P21的水平,初步探讨其可能的作用机制.结果 原代培养时,25% ESC-CM组培养的HCECs P2细胞爬出,细胞形态呈典型多角形结构.CEM在P2时细胞形态变大,失去了多角形结构.25% ESC-CM组和CEM组均表达ZO-1、Na+-K+-ATP酶.25% ESC-CM组的Ki67阳性率、克隆形成数量、进入到细胞周期S期和G2期的比例均高于CEM组(均为P<0.05).25% ESC-CM组的细胞凋亡数量和P21阳性率均低于CEM组(均为P<0.05).结论 25% ESC-CM组可显著促进HCECs增殖;其作用可能是通过抑制P21蛋白的表达和抑制细胞凋亡实现的,为HCECs体外大量扩增提供了一种新方法.

  19. 骨形成蛋白家族成员2、7对小鼠胚胎肝干细胞分化的体外研究%The effecf of bone morphogenetic proteins 2, 7 in inducing murine embryonic stem cells into hepatic cells in vitro

    Institute of Scientific and Technical Information of China (English)

    陈聪; 康权; 罗庆; 迭小红; 田雯

    2013-01-01

    目的 探讨骨形成蛋白2、7(BMP2、BMP7)对小鼠胚胎肝干细胞(HP14.5)定向诱导分化为肝细胞样细胞的影响.方法 将表达BMP2、BMP7、肝细胞生长因子(HGF)和绿色荧光蛋白(GFP)的重组腺病毒作为4个组分别感染HP14.5,诱导其分化,在病毒感染后的第1、4、7天通过检测荧光素酶报告基因读数,在第7天通过细胞免疫荧光染色,观察肝细胞标志物白蛋白(ALB)的表达情况;并在第4、7、10天通过PAS染色、尿素氮合成功能检测,观察诱导后HP14.5向肝细胞方向的分化成熟度.结果 BMP2组、HGF组荧光素酶读数较GFP对照组明显上升;免疫荧光染色显示,诱导7d后BMP2组、HGF组细胞质内表达肝细胞特有的ALB,而GFP对照组几乎无表达;糖原染色可见BMP2组、HGF组胞质存在紫红色颗粒,呈阳性反应;尿素合成功能检测显示BMP2组、HGF组培养液中尿素氮随时间而升高.BMP7组诱导后,细胞免疫荧光染色、荧光素酶活性、PAS染色和尿素合成检测均呈阴性或弱阳性反应.结论 BMP2具有一定的诱导HP14.5向成熟肝细胞分化的作用,并初步具备肝细胞的合成分泌功能,而BMP7对其无诱导作用.%Objective To explore the effect of recombinant adenovirus-mediated bone morphogenetic proteins 2, 7 (Adv-BMP2, Adv-BMP7) in inducing transformation of murine embryonic hepatic progenitor cells to mature hepatic-like cells. Methods HP14.5 cells were divided into 4 groups, and then infected by recombinant adenovirus expressing BMP2, BMP7, hepatocyte growth factor (HGF), and green fluorescent protein (GFP), respectively. For investigating the differential regulation of HP14.S cells, the luciferase report gene was detected at the 1st, 4th and 7th day post infection, the expression of hepatocyte marker albumin (ALB) was detected at the 7th day after infection by cellular immunofluorescence assay. The maturation and differentiation of HP14.S cells were examined by PAS staining

  20. Ets2 determines the inflammatory state of endothelial cells in advanced atherosclerotic lesions

    NARCIS (Netherlands)

    Cheng, C.Y.; Tempel, D.; den Dekker, W.K.; Haasdijk, R.; Chrifi, I.; Bos, F.L.; Wagtmans, K.; van de Kamp, E.H.; Blonden, L.; Biessen, E.A.; Moll, F.L.; Pasterkamp, G.; Serruys, P.W.; Schulte-Merker, S.; Duckers, H.J.

    2011-01-01

    RATIONALE: Neovascularization is required for embryonic development and plays a central role in diseases in adults. In atherosclerosis, the role of neovascularization remains to be elucidated. In a genome-wide microarray-screen of Flk1+ angioblasts during murine embryogenesis, the v-ets erythroblast

  1. Plasma treatment of biomaterials to direct the differentiation of embryonic stem cells

    Science.gov (United States)

    Hanley, Erik

    In this work, we explore how embryonic stem (ES) cell differentiation patterns are affected by surface interactions with plasma-processed materials. We hypothesize that mouse embryonic stem-cell exposure to certain plasma-polymerized tetraglyme surfaces will direct their differentiation into endothelial cells. R1 mouse embryonic stem (ES) cells were plated on surfaces onto which tetraglyme was deposited by plasma polymerization. In addition, tissue-treated polystyrene and control glass cover slips were also examined. Some samples were fixed three days after plating and immunofluorescence stained with platelet endothelial-cell adhesion molecule, while the others were fixed seven days after plating and immunofluorescence stained with von Willebrand Factor. Positive results seen by ES cell derivatives precociously expressing the vWF and PECAM genetic markers on the plasma-polymerized tetraglyme treated surfaces suggest that the plasma-polymerized surfaces direct differentiation of ES cells into endothelial cells. Research goals of this dissertation include: characterization of the material properties of the plasma-polymerized tetraglyme surfaces that induce directed differentiation of ES cells into endothelial cells, optimization of the plasma-polymerization process to maximize the number of endothelial cells derived from R1 ES cells, and biological experimentation to characterize properties of the mechanism of directed differentiation. A potential application of this work is in the design and construction of an artificial blood vessel. Current small-scale arterial substitutes have proved inadequate because of thrombogenicity and infection. Moreover, the lower blood flow velocities of smaller vessels pose a different set of design criteria and introduce new problems not encountered in large arterial substitutes. By utilizing a tissue engineering approach that incorporates embryonic stem cell-derived endothelial cells, the longevity of the prosthesis can be ensured.

  2. Compound-specific effects of diverse neurodevelopmental toxicants on global gene expression in the neural embryonic stem cell test (ESTn)

    NARCIS (Netherlands)

    Theunissen, P.T.; Robinson, J.F.; Pennings, J.L.A.; van Herwijnen, M.; Kleinjans, J.C.S.; Piersma, A.H.

    2012-01-01

    Alternative assays for developmental toxicity testing are needed to reduce animal use in regulatory toxicology. The in vitro murine neural embryonic stem cell test (ESTn) was designed as an alternative for neurodevelopmental toxicity testing. The integration of toxicogenomic-based approaches may fur

  3. [Endothelial cell adhesion molecules].

    Science.gov (United States)

    Ivanov, A N; Norkin, I A; Puchin'ian, D M; Shirokov, V Iu; Zhdanova, O Iu

    2014-01-01

    The review presents current data concerning the functional role of endothelial cell adhesion molecules belonging to different structural families: integrins, selectins, cadherins, and the immunoglobulin super-family. In this manuscript the regulatory mechanisms and factors of adhesion molecules expression and distribution on the surface of endothelial cells are discussed. The data presented reveal the importance of adhesion molecules in the regulation of structural and functional state of endothelial cells in normal conditions and in pathology. Particular attention is paid to the importance of these molecules in the processes of physiological and pathological angiogenesis, regulation of permeability of the endothelial barrier and cell transmigration.

  4. The Role of Runx1 in Embryonic Blood Cell Formation.

    Science.gov (United States)

    Yzaguirre, Amanda D; de Bruijn, Marella F T R; Speck, Nancy A

    2017-01-01

    The de novo generation of hematopoietic stem and progenitor cells (HSPC) occurs solely during embryogenesis from a population of epithelial cells called hemogenic endothelium (HE). During midgestation HE cells in multiple intra- and extraembryonic vascular beds leave the vessel wall as they transition into HSPCs in a process termed the endothelial to hematopoietic transition (EHT). Runx1 expression in HE cells orchestrates the transcriptional switch necessary for the transdifferentiation of endothelial cells into functional HSPCs. Runx1 is widely considered the master regulator of developmental hematopoiesis because it plays an essential function during specification of the hematopoietic lineage during embryogenesis. Here we review the role of Runx1 in embryonic HSPC formation, with a particular focus on its role in hemogenic endothelium.

  5. Endothelial Cells Stimulate Self-Renewal and Expand Neurogenesis of Neural Stem Cells

    Science.gov (United States)

    Shen, Qin; Goderie, Susan K.; Jin, Li; Karanth, Nithin; Sun, Yu; Abramova, Natalia; Vincent, Peter; Pumiglia, Kevin; Temple, Sally

    2004-05-01

    Neural stem cells are reported to lie in a vascular niche, but there is no direct evidence for a functional relationship between the stem cells and blood vessel component cells. We show that endothelial cells but not vascular smooth muscle cells release soluble factors that stimulate the self-renewal of neural stem cells, inhibit their differentiation, and enhance their neuron production. Both embryonic and adult neural stem cells respond, allowing extensive production of both projection neuron and interneuron types in vitro. Endothelial coculture stimulates neuroepithelial cell contact, activating Notch and Hes1 to promote self-renewal. These findings identify endothelial cells as a critical component of the neural stem cell niche.

  6. Matrix metalloproteinase 13 mediates nitric oxide activation of endothelial cell migration

    Science.gov (United States)

    López-Rivera, Esther; Lizarbe, Tania R.; Martínez-Moreno, Mónica; López-Novoa, José Miguel; Rodríguez-Barbero, Alicia; Rodrigo, José; Fernández, Ana Patricia; Álvarez-Barrientos, Alberto; Lamas, Santiago; Zaragoza, Carlos

    2005-01-01

    To explore the mechanisms by which NO elicits endothelial cell (EC) migration we used murine and bovine aortic ECs in an in vitro wound-healing model. We found that exogenous or endogenous NO stimulated EC migration. Moreover, migration was significantly delayed in ECs derived from endothelial NO synthase-deficient mice compared with WT murine aortic EC. To assess the contribution of matrix metalloproteinase (MMP)-13 to NO-mediated EC migration, we used RNA interference to silence MMP-13 expression in ECs. Migration was delayed in cells in which MMP-13 was silenced. In untreated cells MMP-13 was localized to caveolae, forming a complex with caveolin-1. Stimulation with NO disrupted this complex and significantly increased extracellular MMP-13 abundance, leading to collagen breakdown. Our findings show that MMP-13 is an important effector of NO-activated endothelial migration. PMID:15728377

  7. Stem cell-derived vascular endothelial cells and their potential application in regenerative medicine

    Science.gov (United States)

    Although a 'vascular stem cell' population has not been identified or generated, vascular endothelial and mural cells (smooth muscle cells and pericytes) can be derived from currently known pluripotent stem cell sources, including human embryonic stem cells and induced pluripotent stem cells. We rev...

  8. Nitric oxide synthase-3 promotes embryonic development of atrioventricular valves.

    Science.gov (United States)

    Liu, Yin; Lu, Xiangru; Xiang, Fu-Li; Lu, Man; Feng, Qingping

    2013-01-01

    Nitric oxide synthase-3 (NOS3) has recently been shown to promote endothelial-to-mesenchymal transition (EndMT) in the developing atrioventricular (AV) canal. The present study was aimed to investigate the role of NOS3 in embryonic development of AV valves. We hypothesized that NOS3 promotes embryonic development of AV valves via EndMT. To test this hypothesis, morphological and functional analysis of AV valves were performed in wild-type (WT) and NOS3(-/-) mice at postnatal day 0. Our data show that the overall size and length of mitral and tricuspid valves were decreased in NOS3(-/-) compared with WT mice. Echocardiographic assessment showed significant regurgitation of mitral and tricuspid valves during systole in NOS3(-/-) mice. These phenotypes were all rescued by cardiac specific NOS3 overexpression. To assess EndMT, immunostaining of Snail1 was performed in the embryonic heart. Both total mesenchymal and Snail1(+) cells in the AV cushion were decreased in NOS3(-/-) compared with WT mice at E10.5 and E12.5, which was completely restored by cardiac specific NOS3 overexpression. In cultured embryonic hearts, NOS3 promoted transforming growth factor (TGFβ), bone morphogenetic protein (BMP2) and Snail1expression through cGMP. Furthermore, mesenchymal cell formation and migration from cultured AV cushion explants were decreased in the NOS3(-/-) compared with WT mice. We conclude that NOS3 promotes AV valve formation during embryonic heart development and deficiency in NOS3 results in AV valve insufficiency.

  9. Nitric Oxide Synthase-3 Promotes Embryonic Development of Atrioventricular Valves

    Science.gov (United States)

    Liu, Yin; Lu, Xiangru; Xiang, Fu-Li; Lu, Man; Feng, Qingping

    2013-01-01

    Nitric oxide synthase-3 (NOS3) has recently been shown to promote endothelial-to-mesenchymal transition (EndMT) in the developing atrioventricular (AV) canal. The present study was aimed to investigate the role of NOS3 in embryonic development of AV valves. We hypothesized that NOS3 promotes embryonic development of AV valves via EndMT. To test this hypothesis, morphological and functional analysis of AV valves were performed in wild-type (WT) and NOS3−/− mice at postnatal day 0. Our data show that the overall size and length of mitral and tricuspid valves were decreased in NOS3−/− compared with WT mice. Echocardiographic assessment showed significant regurgitation of mitral and tricuspid valves during systole in NOS3−/− mice. These phenotypes were all rescued by cardiac specific NOS3 overexpression. To assess EndMT, immunostaining of Snail1 was performed in the embryonic heart. Both total mesenchymal and Snail1+ cells in the AV cushion were decreased in NOS3−/− compared with WT mice at E10.5 and E12.5, which was completely restored by cardiac specific NOS3 overexpression. In cultured embryonic hearts, NOS3 promoted transforming growth factor (TGFβ), bone morphogenetic protein (BMP2) and Snail1expression through cGMP. Furthermore, mesenchymal cell formation and migration from cultured AV cushion explants were decreased in the NOS3−/− compared with WT mice. We conclude that NOS3 promotes AV valve formation during embryonic heart development and deficiency in NOS3 results in AV valve insufficiency. PMID:24204893

  10. Nitric oxide synthase-3 promotes embryonic development of atrioventricular valves.

    Directory of Open Access Journals (Sweden)

    Yin Liu

    Full Text Available Nitric oxide synthase-3 (NOS3 has recently been shown to promote endothelial-to-mesenchymal transition (EndMT in the developing atrioventricular (AV canal. The present study was aimed to investigate the role of NOS3 in embryonic development of AV valves. We hypothesized that NOS3 promotes embryonic development of AV valves via EndMT. To test this hypothesis, morphological and functional analysis of AV valves were performed in wild-type (WT and NOS3(-/- mice at postnatal day 0. Our data show that the overall size and length of mitral and tricuspid valves were decreased in NOS3(-/- compared with WT mice. Echocardiographic assessment showed significant regurgitation of mitral and tricuspid valves during systole in NOS3(-/- mice. These phenotypes were all rescued by cardiac specific NOS3 overexpression. To assess EndMT, immunostaining of Snail1 was performed in the embryonic heart. Both total mesenchymal and Snail1(+ cells in the AV cushion were decreased in NOS3(-/- compared with WT mice at E10.5 and E12.5, which was completely restored by cardiac specific NOS3 overexpression. In cultured embryonic hearts, NOS3 promoted transforming growth factor (TGFβ, bone morphogenetic protein (BMP2 and Snail1expression through cGMP. Furthermore, mesenchymal cell formation and migration from cultured AV cushion explants were decreased in the NOS3(-/- compared with WT mice. We conclude that NOS3 promotes AV valve formation during embryonic heart development and deficiency in NOS3 results in AV valve insufficiency.

  11. 小鼠胚胎干细胞条件培养液培养的人角膜内皮细胞在脱细胞猪角膜基质上单层细胞片的构建%Formation of cell sheet on acellular porcine corneal stroma with human corneal endothelial cells cocultured by mouse embryonic stem cell conditioned medium

    Institute of Scientific and Technical Information of China (English)

    鹿晓燕; 王智崇

    2016-01-01

    Background Corneal transplantation faces a great challenge because of the shortage of corneal donors and difficulty of human corneal endothelial cells (HCECs) regeneration in vitro.So the study on tissue engineering cornea is still a main topic.Previous research showed that mouse embryonic stem cell conditioned medium (ESC-CM) improved the proliferative capacity of HCECs in vitro,and acellular porcine corneal stroma (APCS) was a good saffold material.However,whether HECEs cultured by mouse ESC-CM can form cell sheet in vitro were rarely studied.Objective This study was to investigate the potential that HCECs cultured by mouse ESC-CM form a monolayer cell sheet.Methods The supernatant of ESC-CM was collected after mouse ES-E14 cells were cultured,and the cultured medium was centrifuged and mixed with 75% human corneal endothelium medium (CEM)at a proportion of 1 ∶ 3 to prepare the 25% ESC-CM system.Primary cultures of HCECs were established from explants of corneal limbal with Descemet's membrane,and the cells were identified by using reverse-transcription PCR to determine the expressions of collagen Ⅷ (Col Ⅷ) mRNA and neuron-specific enolase (NSE) mRNA in the cells.APCS was prepared by decellularization with phospholipase A2 and bicarbonate solution,and the second generation of HCECs were inoculated on the sterilized APCS at a 800/mm2 density.The morphology of the cells was observed by hematoxylin-eosin staining under the phase-contrast microscope.The expressions of zona occludens protein-1 (ZO-1)and Na+-K+-ATPase in the cell sheet were detected by immunofluorescence staining.Results The second generation of HCECs cultured with 25% ESC-CM in vitro showed the hexagon in shape with positive expressions for Col Ⅷ mRNA and NSE mRNA.Decellularization APCS was transparent,and no corneal cells were seen,the structures of corneal collagenous fibres were regular.HCECs attached closely to APCS and formed monolayer sheet 7 days after culture on the APCS with the

  12. Embryonic Stem Cell Markers

    Directory of Open Access Journals (Sweden)

    Lan Ma

    2012-05-01

    Full Text Available Embryonic stem cell (ESC markers are molecules specifically expressed in ES cells. Understanding of the functions of these markers is critical for characterization and elucidation for the mechanism of ESC pluripotent maintenance and self-renewal, therefore helping to accelerate the clinical application of ES cells. Unfortunately, different cell types can share single or sometimes multiple markers; thus the main obstacle in the clinical application of ESC is to purify ES cells from other types of cells, especially tumor cells. Currently, the marker-based flow cytometry (FCM technique and magnetic cell sorting (MACS are the most effective cell isolating methods, and a detailed maker list will help to initially identify, as well as isolate ESCs using these methods. In the current review, we discuss a wide range of cell surface and generic molecular markers that are indicative of the undifferentiated ESCs. Other types of molecules, such as lectins and peptides, which bind to ESC via affinity and specificity, are also summarized. In addition, we review several markers that overlap with tumor stem cells (TSCs, which suggest that uncertainty still exists regarding the benefits of using these markers alone or in various combinations when identifying and isolating cells.

  13. Stromal cell-derived factor-1/CXCR4 signaling modifies the capillary-like organization of human embryonic stem cell-derived endothelium in vitro.

    Science.gov (United States)

    Chen, Tong; Bai, Hao; Shao, Ying; Arzigian, Melanie; Janzen, Viktor; Attar, Eyal; Xie, Yi; Scadden, David T; Wang, Zack Z

    2007-02-01

    The molecular mechanisms that regulate human blood vessel formation during early development are largely unknown. Here we used human ESCs (hESCs) as an in vitro model to explore early human vasculogenesis. We demonstrated that stromal cell-derived factor-1 (SDF-1) and CXCR4 were expressed concurrently with hESC-derived embryonic endothelial differentiation. Human ESC-derived embryonic endothelial cells underwent dose-dependent chemotaxis to SDF-1, which enhanced vascular network formation in Matrigel. Blocking of CXCR4 signaling abolished capillary-like structures induced by SDF-1. Inhibition of the SDF-1/CXCR4 signaling pathway by AMD3100, a CXCR4 antagonist, disrupted the endothelial sprouting outgrowth from human embryoid bodies, suggesting that the SDF-1/CXCR4 axis plays a critical role in regulating initial vessel formation, and may function as a morphogen during human embryonic vascular development.

  14. Endothelial RhoGEFs: A systematic analysis of their expression profiles in VEGF-stimulated and tumor endothelial cells.

    Science.gov (United States)

    Hernández-García, Ricardo; Iruela-Arispe, M Luisa; Reyes-Cruz, Guadalupe; Vázquez-Prado, José

    2015-11-01

    Rho guanine nucleotide exchange factors (RhoGEFs) integrate cell signaling inputs into morphological and functional responses. However, little is known about the endothelial repertoire of RhoGEFs and their regulation. Thus, we assessed the expression of 81 RhoGEFs (70 homologous to Dbl and 11 of the DOCK family) in endothelial cells. Further, in the case of DH-RhoGEFs, we also determined their responses to VEGF exposure in vitro and in the context of tumors. A phylogenetic analysis revealed the existence of four groups of DH-RhoGEFs and two of the DOCK family. Among them, we found that the most abundant endothelial RhoGEFs were: Tuba, FGD5, Farp1, ARHGEF17, TRIO, P-Rex1, ARHGEF15, ARHGEF11, ABR, Farp2, ARHGEF40, ALS, DOCK1, DOCK7 and DOCK6. Expression of RASGRF2 and PREX2 increased significantly in response to VEGF, but most other RhoGEFs were unaffected. Interestingly murine endothelial cells isolated from tumors showed that all four phylogenetic subgroups of DH-RhoGEFs were altered when compared to non-tumor endothelial cells. In summary, our results provide a detailed assessment of RhoGEFs expression profiles in the endothelium and set the basis to systematically address their regulation in vascular signaling.

  15. Endothelial cells regulate neural crest and second heart field morphogenesis.

    Science.gov (United States)

    Milgrom-Hoffman, Michal; Michailovici, Inbal; Ferrara, Napoleone; Zelzer, Elazar; Tzahor, Eldad

    2014-07-04

    Cardiac and craniofacial developmental programs are intricately linked during early embryogenesis, which is also reflected by a high frequency of birth defects affecting both regions. The molecular nature of the crosstalk between mesoderm and neural crest progenitors and the involvement of endothelial cells within the cardio-craniofacial field are largely unclear. Here we show in the mouse that genetic ablation of vascular endothelial growth factor receptor 2 (Flk1) in the mesoderm results in early embryonic lethality, severe deformation of the cardio-craniofacial field, lack of endothelial cells and a poorly formed vascular system. We provide evidence that endothelial cells are required for migration and survival of cranial neural crest cells and consequently for the deployment of second heart field progenitors into the cardiac outflow tract. Insights into the molecular mechanisms reveal marked reduction in Transforming growth factor beta 1 (Tgfb1) along with changes in the extracellular matrix (ECM) composition. Our collective findings in both mouse and avian models suggest that endothelial cells coordinate cardio-craniofacial morphogenesis, in part via a conserved signaling circuit regulating ECM remodeling by Tgfb1.

  16. Endothelial cells regulate neural crest and second heart field morphogenesis

    Directory of Open Access Journals (Sweden)

    Michal Milgrom-Hoffman

    2014-07-01

    Full Text Available Cardiac and craniofacial developmental programs are intricately linked during early embryogenesis, which is also reflected by a high frequency of birth defects affecting both regions. The molecular nature of the crosstalk between mesoderm and neural crest progenitors and the involvement of endothelial cells within the cardio–craniofacial field are largely unclear. Here we show in the mouse that genetic ablation of vascular endothelial growth factor receptor 2 (Flk1 in the mesoderm results in early embryonic lethality, severe deformation of the cardio–craniofacial field, lack of endothelial cells and a poorly formed vascular system. We provide evidence that endothelial cells are required for migration and survival of cranial neural crest cells and consequently for the deployment of second heart field progenitors into the cardiac outflow tract. Insights into the molecular mechanisms reveal marked reduction in Transforming growth factor beta 1 (Tgfb1 along with changes in the extracellular matrix (ECM composition. Our collective findings in both mouse and avian models suggest that endothelial cells coordinate cardio–craniofacial morphogenesis, in part via a conserved signaling circuit regulating ECM remodeling by Tgfb1.

  17. Derivation, propagation and differentiation of human embryonic stem cells.

    Science.gov (United States)

    Conley, Brock J; Young, Julia C; Trounson, Alan O; Mollard, Richard

    2004-04-01

    Embryonic stem (ES) cells are in vitro cultivated pluripotent cells derived from the inner cell mass (ICM) of the embryonic blastocyst. Attesting to their pluripotency, ES cells can be differentiated into representative derivatives of all three embryonic germ layers (endoderm, ectoderm and mesoderm) both in vitro and in vivo. Although mouse ES cells have been studied for many years, human ES cells have only more recently been derived and successfully propagated. Many biochemical differences and culture requirements between mouse and human ES cells have been described, yet despite these differences the study of murine ES cells has provided important insights into methodologies aimed at generating a greater and more in depth understanding of human ES cell biology. One common feature of both mouse and human ES cells is their capacity to undergo controlled differentiation into spheroid structures termed embryoid bodies (EBs). EBs recapitulate several aspects of early development, displaying regional-specific differentiation programs into derivatives of all three embryonic germ layers. For this reason, EB formation has been utilised as an initial step in a wide range of studies aimed at differentiating both mouse and human ES cells into a specific and desired cell type. Recent reports utilising specific growth factor combinations and cell-cell induction systems have provided alternative strategies for the directed differentiation of cells into a desired lineage. According to each one of these strategies, however, a relatively high cell lineage heterogeneity remains, necessitating subsequent purification steps including mechanical dissection, selective media or fluorescent or magnetic activated cell sorting (FACS and MACS, respectively). In the future, the ability to specifically direct differentiation of human ES cells at 100% efficiency into a desired lineage will allow us to fully explore the potential of these cells in the analysis of early human development, drug

  18. Integrin Based Isolation Enables Purification of Murine Lineage Committed Cardiomyocytes.

    Directory of Open Access Journals (Sweden)

    Laura Tarnawski

    Full Text Available In contrast to mature cardiomyocytes which have limited regenerative capacity, pluripotent stem cells represent a promising source for the generation of new cardiomyocytes. The tendency of pluripotent stem cells to form teratomas and the heterogeneity from various differentiation stages and cardiomyocyte cell sub-types, however, are major obstacles to overcome before this type of therapy could be applied in a clinical setting. Thus, the identification of extracellular markers for specific cardiomyocyte progenitors and mature subpopulations is of particular importance. The delineation of cardiomyocyte surface marker patterns not only serves as a means to derive homogeneous cell populations by FACS, but is also an essential tool to understand cardiac development. By using single-cell expression profiling in early mouse embryonic hearts, we found that a combination of integrin alpha-1, alpha-5, alpha-6 and N-cadherin enables isolation of lineage committed murine cardiomyocytes. Additionally, we were able to separate trabecular cardiomyocytes from solid ventricular myocardium and atrial murine cells. These cells exhibit expected subtype specific phenotype confirmed by electrophysiological analysis. We show that integrin expression can be used for the isolation of living, functional and lineage-specific murine cardiomyocytes.

  19. Embryonic death and the creation of human embryonic stem cells

    OpenAIRE

    Landry, Donald W.; Zucker, Howard A.

    2004-01-01

    The creation of human embryonic stem cells through the destruction of a human embryo pits the value of a potential therapeutic tool against that of an early human life. This contest of values has resulted in a polarized debate that neglects areas of common interest and perspective. We suggest that a common ground for pursuing research on human embryonic stem cells can be found by reconsidering the death of the human embryo and by applying to this research the ethical norms of essential organ ...

  20. Embryonic death and the creation of human embryonic stem cells.

    Science.gov (United States)

    Landry, Donald W; Zucker, Howard A

    2004-11-01

    The creation of human embryonic stem cells through the destruction of a human embryo pits the value of a potential therapeutic tool against that of an early human life. This contest of values has resulted in a polarized debate that neglects areas of common interest and perspective. We suggest that a common ground for pursuing research on human embryonic stem cells can be found by reconsidering the death of the human embryo and by applying to this research the ethical norms of essential organ donation.

  1. Cell cycle features of primate embryonic stem cells.

    Science.gov (United States)

    Fluckiger, Anne-Catherine; Marcy, Guillaume; Marchand, Mélanie; Négre, Didier; Cosset, François-Loïc; Mitalipov, Shoukhrat; Wolf, Don; Savatier, Pierre; Dehay, Colette

    2006-03-01

    Using flow cytometry measurements combined with quantitative analysis of cell cycle kinetics, we show that rhesus monkey embryonic stem cells (ESCs) are characterized by an extremely rapid transit through the G1 phase, which accounts for 15% of the total cell cycle duration. Monkey ESCs exhibit a non-phasic expression of cyclin E, which is detected during all phases of the cell cycle, and do not growth-arrest in G1 after gamma-irradiation, reflecting the absence of a G1 checkpoint. Serum deprivation or pharmacological inhibition of mitogen-activated protein kinase kinase (MEK) did not result in any alteration in the cell cycle distribution, indicating that ESC growth does not rely on mitogenic signals transduced by the Ras/Raf/MEK pathway. Taken together, these data indicate that rhesus monkey ESCs, like their murine counterparts, exhibit unusual cell cycle features in which cell cycle control mechanisms operating during the G1 phase are reduced or absent.

  2. Cloning of murine BRI3 gene and study on its function for inducing cell death

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    To understand the molecular mechanism of TNFα effects, the cDNA of murine BRI3 gene was cloned from the total RNA of murine brain endothelial cells (bEnd.3)treated with hTNFα by using the suppression subtractive hybridization (SSH) and the RT-PCR method. The fusion expression vector harbouring BRI3 gene and enhanced green fluorescence protein (EGFP) thus obtained were designated as pEGFP/I3. Then pEGFP/I3 was transiently transfected into L929 cells and the fusion protein EGFP/I3 was localized in cytoplasm. It is found that the expression of EGFP/I3 could induce cell death in L929 cells detected by TUNEL method and flow cytometry. And the overexpression of Bci-2 in L929 cells can block cell death induced by EGFP/I3, indicating that murine BRI3 gene might related to the TNFα mediated cytotoxicity.

  3. Microfluidic-based patterning of embryonic stem cells for in vitro development studies.

    Science.gov (United States)

    Suri, Shalu; Singh, Ankur; Nguyen, Anh H; Bratt-Leal, Andres M; McDevitt, Todd C; Lu, Hang

    2013-12-07

    In vitro recapitulation of mammalian embryogenesis and examination of the emerging behaviours of embryonic structures require both the means to engineer complexity and accurately assess phenotypes of multicellular aggregates. Current approaches to study multicellular populations in 3D configurations are limited by the inability to create complex (i.e. spatially heterogeneous) environments in a reproducible manner with high fidelity thus impeding the ability to engineer microenvironments and combinations of cells with similar complexity to that found during morphogenic processes such as development, remodelling and wound healing. Here, we develop a multicellular embryoid body (EB) fusion technique as a higher-throughput in vitro tool, compared to a manual assembly, to generate developmentally relevant embryonic patterns. We describe the physical principles of the EB fusion microfluidic device design; we demonstrate that >60 conjoined EBs can be generated overnight and emulate a development process analogous to mouse gastrulation during early embryogenesis. Using temporal delivery of bone morphogenic protein 4 (BMP4) to embryoid bodies, we recapitulate embryonic day 6.5 (E6.5) during mouse embryo development with induced mesoderm differentiation in murine embryonic stem cells leading to expression of Brachyury-T-green fluorescent protein (T-GFP), an indicator of primitive streak development and mesoderm differentiation during gastrulation. The proposed microfluidic approach could be used to manipulate hundreds or more of individual embryonic cell aggregates in a rapid fashion, thereby allowing controlled differentiation patterns in fused multicellular assemblies to generate complex yet spatially controlled microenvironments.

  4. Isolated tumor endothelial cells maintain specific character during long-term culture

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Kohei [Vascular Biology, Hokkaido University Graduate School of Dental Medicine, N13 W7, Kita-ku, Sapporo 060-8586 (Japan); Oral Pathology and Biology, Hokkaido University Graduate School of Dental Medicine, N13 W7, Kita-ku, Sapporo 060-8586 (Japan); Oral and Maxillofacial Surgery, Hokkaido University Graduate School of Dental Medicine, N13 W7, Kita-ku, Sapporo 060-8586 (Japan); Ohga, Noritaka [Vascular Biology, Hokkaido University Graduate School of Dental Medicine, N13 W7, Kita-ku, Sapporo 060-8586 (Japan); Hida, Yasuhiro [Surgical Oncology, Hokkaido University Graduate School of Medicine, N13 W7, Kita-ku, Sapporo 060-8586 (Japan); Muraki, Chikara [Oral Pathology and Biology, Hokkaido University Graduate School of Dental Medicine, N13 W7, Kita-ku, Sapporo 060-8586 (Japan); Oral and Maxillofacial Surgery, Hokkaido University Graduate School of Dental Medicine, N13 W7, Kita-ku, Sapporo 060-8586 (Japan); Tsuchiya, Kunihiko [Vascular Biology, Hokkaido University Graduate School of Dental Medicine, N13 W7, Kita-ku, Sapporo 060-8586 (Japan); Renal and Genitourinary Surgery, Hokkaido University Graduate School of Medicine, N13 W7, Kita-ku, Sapporo 060-8586 (Japan); Kurosu, Takuro [Vascular Biology, Hokkaido University Graduate School of Dental Medicine, N13 W7, Kita-ku, Sapporo 060-8586 (Japan); Oral Pathology and Biology, Hokkaido University Graduate School of Dental Medicine, N13 W7, Kita-ku, Sapporo 060-8586 (Japan); Oral and Maxillofacial Surgery, Hokkaido University Graduate School of Dental Medicine, N13 W7, Kita-ku, Sapporo 060-8586 (Japan); Akino, Tomoshige [Vascular Biology, Hokkaido University Graduate School of Dental Medicine, N13 W7, Kita-ku, Sapporo 060-8586 (Japan); Renal and Genitourinary Surgery, Hokkaido University Graduate School of Medicine, N13 W7, Kita-ku, Sapporo 060-8586 (Japan); Shih, Shou-Ching [Pathology, Beth Israel Deaconess Medical Center, 330 Brookline Ave, Boston, MA 02215 (United States); and others

    2010-04-16

    Tumor angiogenesis is necessary for solid tumor progression and metastasis. Increasing evidence indicates that tumor endothelial cells (TECs) are more relevant to the study of tumor angiogenesis than normal endothelial cells (NECs) because their morphologies and gene expression are different from NECs. However, it is challenging to isolate and culture large numbers of pure ECs from tumor tissue since the percentage of ECs is only about 1-2% and tumor cells and fibroblasts easily overgrow them. In addition, there has been concern that isolated TECs may lose their special phenotype once they are dissociated from tumor cells. In this study, we have successfully purified murine TECs from four different human tumor xenografts and NECs from murine dermal tissue. Isolated ECs expressed endothelial markers, such as CD31, VE-cadherin (CD144), and endoglin (CD105), for more than 3 months after isolation. TECs maintained tumor endothelial-specific markers, such as tumor endothelial marker 8 (TEM8) and aminopeptidase N (APN), as in tumor blood vessels in vivo. In addition, TECs were more proliferative and motile than NECs. TECs showed a higher response to VEGF and higher expression of VEGF receptors-1 and -2 than NECs did. Stem cell antigen-1 was up-regulated in all four TECs, suggesting that they have a kind of stemness. Cultured TECs maintain distinct biological differences from NECs as in vivo. In conclusion, it was suggested that TECs are relevant material for tumor angiogenesis research.

  5. Embryonal rhabdomyosarcoma of the cervix

    Directory of Open Access Journals (Sweden)

    Ocheke A

    2011-01-01

    Full Text Available Embryonal rhabdomyosarcoma (sarcoma botyroides of the cervix, which is rare, is described in a 16-year-old. The combined use of chemotherapy, radiotherapy and surgery has markedly improved survival in those with this condition. However, our patient did not benefit from this treatment modality due to late presentation and loss to follow-up.

  6. The 894G>T variant in the endothelial nitric oxide synthase gene and spina bifida risk

    NARCIS (Netherlands)

    Linden, I.J. van der; Heil, S.G.; Heijer, M. den; Blom, H.J.

    2007-01-01

    The 894G>T single nucleotide polymorphism (SNP) in the endothelial NOS (NOS3) gene, has recently been associated with embryonic spina bifida risk. In this study, a possible association between the NOS3 894G>T SNP and spina bifida risk in both mothers and children in a Dutch population was examined

  7. Qualitative and quantitative proteomic profiling of cripto(-/-) embryonic stem cells by means of accurate mass LC-MS analysis.

    Science.gov (United States)

    Chambery, Angela; Vissers, Johannes P C; Langridge, James I; Lonardo, Enza; Minchiotti, Gabriella; Ruvo, Menotti; Parente, Augusto

    2009-02-01

    Cripto is one of the key regulators of embryonic stem cells (ESCs) differentiation into cardiomyocites vs neuronal fate. Cripto(-/-) murine ESCs have been utilized to investigate the molecular mechanisms underlying early events of mammalian lineage differentiation. 2D/LC-MS/MS and a label-free LC-MS approaches were used to qualitatively and quantitatively profile the cripto(-/-) ESC proteome, providing an integral view of the alterations induced in stem cell functions by deleting the cripto gene.

  8. Induction of hematopoietic and endothelial cell program orchestrated by ETS transcription factor ER71/ETV2.

    Science.gov (United States)

    Liu, Fang; Li, Daofeng; Yu, Yik Yeung Lawrence; Kang, Inyoung; Cha, Min-Ji; Kim, Ju Young; Park, Changwon; Watson, Dennis K; Wang, Ting; Choi, Kyunghee

    2015-05-01

    The ETS factor ETV2 (aka ER71) is essential for the generation of the blood and vascular system, as ETV2 deficiency leads to a complete block in blood and endothelial cell formation and embryonic lethality in the mouse. However, the ETV2-mediated gene regulatory network and signaling governing hematopoietic and endothelial cell development are poorly understood. Here, we map ETV2 global binding sites and carry out in vitro differentiation of embryonic stem cells, and germ line and conditional knockout mouse studies to uncover mechanisms involved in the hemangiogenic fate commitment from mesoderm. We show that ETV2 binds to enhancers that specify hematopoietic and endothelial cell lineages. We find that the hemangiogenic progenitor population in the developing embryo can be identified as FLK1(high)PDGFRα(-). Notably, these hemangiogenic progenitors are exclusively sensitive to ETV2-dependent FLK1 signaling. Importantly, ETV2 turns on other Ets genes, thereby establishing an ETS hierarchy. Consequently, the hematopoietic and endothelial cell program initiated by ETV2 is maintained partly by other ETS factors through an ETS switching mechanism. These findings highlight the critical role that transient ETV2 expression plays in the regulation of hematopoietic and endothelial cell lineage specification and stability. © 2015 The Authors.

  9. Embryonic vasculogenesis and hematopoietic specification

    Science.gov (United States)

    Vasculogenesis is the process by which blood vessels are formed de novo. In mammals, vasculogenesis occurs in parallel with hematopoiesis, the formation of blood cells. Thus, it is debated whether vascular endothelial cells and blood cells are derived from a common progenitor. Whether or not this is...

  10. Redundant role of protein kinase C delta and epsilon during mouse embryonic development.

    Directory of Open Access Journals (Sweden)

    Sergio Carracedo

    Full Text Available Protein Kinase C delta and epsilon are mediators of important cellular events, such as cell proliferation, migration or apoptosis. The formation of blood vessels, i.e., vasculo- and angiogenesis, is a process where these isoforms have also been shown to participate. However, mice deficient in either Protein Kinase C delta or epsilon are viable and therefore their individual contribution to the formation of the vasculature appeared so far dispensable. In this study, we show that double null mutation of Protein Kinase C delta and epsilon causes embryonic lethality at approximately E9.5. At this stage, whole mount staining of the endothelial marker CD31 in double null embryos revealed defective blood vessel formation. Moreover, culture of double deficient mouse allantois showed impaired endothelial cell organization, and analyses of double deficient embryo sections showed dilated vessels, decreased endothelial-specific adherent junctions, and decreased contact of endothelial cells with mural cells. Protein kinase C delta and epsilon also appeared essential for vascular smooth muscle cell differentiation, since α-smooth muscle actin, a classical marker for vascular smooth muscle cells, was almost undetectable in double deficient embryonic aorta at E9.5. Subsequent qPCR analyses showed decreased VE-cadherin, Vegfr2, Cd31, Cdh2, Ets1, and Fli-1, among other angiogenesis related transcripts in double deficient embryos. Taken together, these data suggest for the first time an in vivo redundant role between members of the novel Protein Kinase C subfamily that allows for mutual compensation during mouse embryonic development, with vasculogenesis/angiogenesis as an obvious common function of these two Protein Kinase Cs. Protein Kinase C delta and epsilon might therefore be useful targets for inhibiting vasculo- and/or angiogenesis.

  11. Redundant role of protein kinase C delta and epsilon during mouse embryonic development.

    Science.gov (United States)

    Carracedo, Sergio; Sacher, Frank; Brandes, Gudrun; Braun, Ursula; Leitges, Michael

    2014-01-01

    Protein Kinase C delta and epsilon are mediators of important cellular events, such as cell proliferation, migration or apoptosis. The formation of blood vessels, i.e., vasculo- and angiogenesis, is a process where these isoforms have also been shown to participate. However, mice deficient in either Protein Kinase C delta or epsilon are viable and therefore their individual contribution to the formation of the vasculature appeared so far dispensable. In this study, we show that double null mutation of Protein Kinase C delta and epsilon causes embryonic lethality at approximately E9.5. At this stage, whole mount staining of the endothelial marker CD31 in double null embryos revealed defective blood vessel formation. Moreover, culture of double deficient mouse allantois showed impaired endothelial cell organization, and analyses of double deficient embryo sections showed dilated vessels, decreased endothelial-specific adherent junctions, and decreased contact of endothelial cells with mural cells. Protein kinase C delta and epsilon also appeared essential for vascular smooth muscle cell differentiation, since α-smooth muscle actin, a classical marker for vascular smooth muscle cells, was almost undetectable in double deficient embryonic aorta at E9.5. Subsequent qPCR analyses showed decreased VE-cadherin, Vegfr2, Cd31, Cdh2, Ets1, and Fli-1, among other angiogenesis related transcripts in double deficient embryos. Taken together, these data suggest for the first time an in vivo redundant role between members of the novel Protein Kinase C subfamily that allows for mutual compensation during mouse embryonic development, with vasculogenesis/angiogenesis as an obvious common function of these two Protein Kinase Cs. Protein Kinase C delta and epsilon might therefore be useful targets for inhibiting vasculo- and/or angiogenesis.

  12. Mecanotransduction and Endothelial Cells

    Institute of Scientific and Technical Information of China (English)

    S.MULLER; JF.; STOLTZ2

    2005-01-01

    1 IntroductionAtherosclerosis preferentially occurs in areas of complex blood flow where there are disturbed flow and low fluid shear stress, whereas laminar blood flow and high shear stress are atheroprotective~([1]). Reports of others and our studies suggest a steady laminar flow decreases some molecules and genes expression of vascular endothelial cells (EC) that may promote atherosclerosis, as well as it can differentially regulate production of many vasoactive factors at the level of gene expression an...

  13. Recovering endothelial function

    OpenAIRE

    Bryce Moncloa, Alfonso; Médico Cardiólogo, Académico Asociado de la Academia Nacional de Medicina, Presidente del Colegio Panamericano del Endotelio, Miembro del Comité Institucional de Investigaciones del Comité Ejecutivo de la Sociedad Latino Americana de Hipertensión Arterial y del Colegio Americano de Cardiología (ACC).; Morales Villegas, Enrique C.; Médico Internista y Cardiólogo, Fundador y Director del Centro de Investigación Cardiometabólica de Aguascalientes. México; Urquiaga Calderón, Juan; Médico Internista y Cardiólogo, Fundador y Director del Centro de Investigación Cardiometabólica de Aguascalientes. México; Larrauri Vigna, Cesar; Médico Cardiólogo, Miembro de la Sociedad Peruana de Cardiología, Sociedad Peruana de Hipertensión, Sociedad Peruana de Medicina Interna, Colegio Panamericano del Endotelio.

    2014-01-01

    Atherosclerosis starts early in life. The presence of risk factors like hypertension, smoking, dyslipidemia and diabetes as well as obesity and metabolic syndrome accelerates its progress. These factors generate endothelial dysfunction, oxidative stress and inflammation, with early appearance of foamy cells, fatty streaks and atheromatous plaques. These plaques are vulnerable to erosion and rupture, the so called atherothrombotic phenomenon, leading to acute vascular events like acute coronar...

  14. Identification of novel targets for antiangiogenic therapy by comparing the gene expressions of tumor and normal endothelial cells

    Science.gov (United States)

    Otsubo, Tsuguteru; Hida, Yasuhiro; Ohga, Noritaka; Sato, Hideshi; Kai, Toshihiro; Matsuki, Yasushi; Takasu, Hideo; Akiyama, Kosuke; Maishi, Nako; Kawamoto, Taisuke; Shinohara, Nobuo; Nonomura, Katsuya; Hida, Kyoko

    2014-01-01

    Targeting tumor angiogenesis is an established strategy for cancer therapy. Because angiogenesis is not limited to pathological conditions such as cancer, molecular markers that can distinguish between physiological and pathological angiogenesis are required to develop more effective and safer approaches for cancer treatment. To identify such molecules, we determined the gene expression profiles of murine tumor endothelial cells (mTEC) and murine normal endothelial cells using DNA microarray analysis followed by quantitative reverse transcription–polymerase chain reaction analysis. We identified 131 genes that were differentially upregulated in mTEC. Functional analysis using siRNA-mediated gene silencing revealed five novel tumor endothelial cell markers that were involved in the proliferation or migration of mTEC. The expression of DEF6 and TMEM176B was upregulated in tumor vessels of human renal cell carcinoma specimens, suggesting that they are potential targets for antiangiogenic intervention for renal cell carcinoma. Comparative gene expression analysis revealed molecular differences between tumor endothelial cells and normal endothelial cells and identified novel tumor endothelial cell markers that may be exploited to target tumor angiogenesis for cancer treatment. PMID:24602018

  15. Embryonic Heart Progenitors and Cardiogenesis

    Science.gov (United States)

    Brade, Thomas; Pane, Luna S.; Moretti, Alessandra; Chien, Kenneth R.; Laugwitz, Karl-Ludwig

    2013-01-01

    The mammalian heart is a highly specialized organ, comprised of many different cell types arising from distinct embryonic progenitor populations during cardiogenesis. Three precursor populations have been identified to contribute to different myocytic and nonmyocytic cell lineages of the heart: cardiogenic mesoderm cells (CMC), the proepicardium (PE), and cardiac neural crest cells (CNCCs). This review will focus on molecular cues necessary for proper induction, expansion, and lineage-specific differentiation of these progenitor populations during cardiac development in vivo. Moreover, we will briefly discuss how the knowledge gained on embryonic heart progenitor biology can be used to develop novel therapeutic strategies for the management of congenital heart disease as well as for improvement of cardiac function in ischemic heart disease. PMID:24086063

  16. The birth of embryonic pluripotency

    OpenAIRE

    Boroviak, Thorsten; Nichols, Jennifer

    2014-01-01

    This is the final published version. It first appeared at http://rstb.royalsocietypublishing.org/content/369/1657/20130541. Formation of a eutherian mammal requires concurrent establishment of embryonic and extraembryonic lineages. The functions of the trophectoderm and primitive endoderm are to enable implantation in the maternal uterus, axis specification and delivery of nutrients. The pluripotent epiblast represents the founding cell population of the embryo proper, which is...

  17. SIRT1 deficiency compromises mouse embryonic stem cell hematopoietic differentiation, and embryonic and adult hematopoiesis in the mouse

    Science.gov (United States)

    Ou, Xuan; Chae, Hee-Don; Wang, Rui-Hong; Shelley, William C.; Cooper, Scott; Taylor, Tammi; Kim, Young-June; Deng, Chu-Xia; Yoder, Mervin C.

    2011-01-01

    SIRT1 is a founding member of a sirtuin family of 7 proteins and histone deacetylases. It is involved in cellular resistance to stress, metabolism, differentiation, aging, and tumor suppression. SIRT1−/− mice demonstrate embryonic and postnatal development defects. We examined hematopoietic and endothelial cell differentiation of SIRT1−/− mouse embryonic stem cells (ESCs) in vitro, and hematopoietic progenitors in SIRT1+/++/−, and −/− mice. SIRT1−/− ESCs formed fewer mature blast cell colonies. Replated SIRT1−/− blast colony-forming cells demonstrated defective hematopoietic potential. Endothelial cell production was unaltered, but there were defects in formation of a primitive vascular network from SIRT1−/−-derived embryoid bodies. Development of primitive and definitive progenitors derived from SIRT1−/− ESCs were also delayed and/or defective. Differentiation delay/defects were associated with delayed capacity to switch off Oct4, Nanog and Fgf5 expression, decreased β-H1 globin, β-major globin, and Scl gene expression, and reduced activation of Erk1/2. Ectopic expression of SIRT1 rescued SIRT1−/− ESC differentiation deficiencies. SIRT1−/− yolk sacs manifested fewer primitive erythroid precursors. SIRT1−/− and SIRT1+/− adult marrow had decreased numbers and cycling of hematopoietic progenitors, effects more apparent at 5%, than at 20%, oxygen tension, and these progenitors survived less well in vitro under conditions of delayed growth factor addition. This suggests a role for SIRT1 in ESC differentiation and mouse hematopoiesis. PMID:20966168

  18. Zebrafish Caudal Haematopoietic Embryonic Stromal Tissue (CHEST) Cells Support Haematopoiesis

    Science.gov (United States)

    Wolf, Anja; Aggio, Julian; Campbell, Clyde; Wright, Francis; Marquez, Gabriel; Traver, David; Stachura, David L.

    2017-01-01

    Haematopoiesis is an essential process in early vertebrate development that occurs in different distinct spatial locations in the embryo that shift over time. These different sites have distinct functions: in some anatomical locations specific hematopoietic stem and progenitor cells (HSPCs) are generated de novo. In others, HSPCs expand. HSPCs differentiate and renew in other locations, ensuring homeostatic maintenance. These niches primarily control haematopoiesis through a combination of cell-to-cell signalling and cytokine secretion that elicit unique biological effects in progenitors. To understand the molecular signals generated by these niches, we report the generation of caudal hematopoietic embryonic stromal tissue (CHEST) cells from 72-hours post fertilization (hpf) caudal hematopoietic tissue (CHT), the site of embryonic HSPC expansion in fish. CHEST cells are a primary cell line with perivascular endothelial properties that expand hematopoietic cells in vitro. Morphological and transcript analysis of these cultures indicates lymphoid, myeloid, and erythroid differentiation, indicating that CHEST cells are a useful tool for identifying molecular signals critical for HSPC proliferation and differentiation in the zebrafish. These findings permit comparison with other temporally and spatially distinct haematopoietic-supportive zebrafish niches, as well as with mammalian haematopoietic-supportive cells to further the understanding of the evolution of the vertebrate hematopoietic system. PMID:28300168

  19. Differentiation of mouse embryonic stem cells and their hybrids during embryoid body formation

    Directory of Open Access Journals (Sweden)

    Josane Mittmann

    2002-01-01

    Full Text Available We studied the karyotypes of three hybrid clones of mouse embryonic stem cells and murine splenocytes (two having near diploid and one having near tetraploid chromosome numbers and the characteristics of their differentiation during the formation of embryoid bodies. The X chromosome originating from embryonic stem cells may be lost in hybrids with a near diploid chromosome number and reprogramming of the "somatic" X may occur. The morphological data we obtained using light and electron microscopy revealed a correlation between the karyotype constitution of hybrid cells and their differentiation during the formation of embryoid bodies. At the beginning of development, the embryoid bodies derived from hybrid cells already showed an advanced degree of differentiation. The production of significant quantities of cartilage was typical for hybrid cells with near tetraploid chromosome numbers. The hybrid cells showed restricted pluripotent capacity and were already committed when they started to differentiate into embryoid bodies.

  20. Endothelial RIG-I activation impairs endothelial function

    Energy Technology Data Exchange (ETDEWEB)

    Asdonk, Tobias, E-mail: tobias.asdonk@ukb.uni-bonn.de [Department of Medicine/Cardiology, University of Bonn, Sigmund-Freud-Str. 25, 53105 Bonn (Germany); Motz, Inga; Werner, Nikos [Department of Medicine/Cardiology, University of Bonn, Sigmund-Freud-Str. 25, 53105 Bonn (Germany); Coch, Christoph; Barchet, Winfried; Hartmann, Gunther [Institute for Clinical Chemistry and Clinical Pharmacology, University of Bonn, Sigmund-Freud-Str. 25, 53105 Bonn (Germany); Nickenig, Georg; Zimmer, Sebastian [Department of Medicine/Cardiology, University of Bonn, Sigmund-Freud-Str. 25, 53105 Bonn (Germany)

    2012-03-30

    Highlights: Black-Right-Pointing-Pointer RIG-I activation impairs endothelial function in vivo. Black-Right-Pointing-Pointer RIG-I activation alters HCAEC biology in vitro. Black-Right-Pointing-Pointer EPC function is affected by RIG-I stimulation in vitro. -- Abstract: Background: Endothelial dysfunction is a crucial part of the chronic inflammatory atherosclerotic process and is mediated by innate and acquired immune mechanisms. Recent studies suggest that pattern recognition receptors (PRR) specialized in immunorecognition of nucleic acids may play an important role in endothelial biology in a proatherogenic manner. Here, we analyzed the impact of endothelial retinoic acid inducible gene I (RIG-I) activation upon vascular endothelial biology. Methods and results: Wild type mice were injected intravenously with 32.5 {mu}g of the RIG-ligand 3pRNA (RNA with triphosphate at the 5 Prime end) or polyA control every other day for 7 days. In 3pRNA-treated mice, endothelium-depended vasodilation was significantly impaired, vascular oxidative stress significantly increased and circulating endothelial microparticle (EMP) numbers significantly elevated compared to controls. To gain further insight in RIG-I dependent endothelial biology, cultured human coronary endothelial cells (HCAEC) and endothelial progenitor cells (EPC) were stimulated in vitro with 3pRNA. Both cells types express RIG-I and react with receptor upregulation upon stimulation. Reactive oxygen species (ROS) formation is enhanced in both cell types, whereas apoptosis and proliferation is not significantly affected in HCAEC. Importantly, HCAEC release significant amounts of proinflammatory cytokines in response to RIG-I stimulation. Conclusion: This study shows that activation of the cytoplasmatic nucleic acid receptor RIG-I leads to endothelial dysfunction. RIG-I induced endothelial damage could therefore be an important pathway in atherogenesis.

  1. Generation of iPSC line epiHUVEC from human umbilical vein endothelial cells

    Directory of Open Access Journals (Sweden)

    Peggy Matz

    2015-11-01

    Full Text Available Human umbilical vein endothelial cells (HUVECs were used to generate the iPSC line epiHUVEC employing a combination of three episomal-based plasmids expressing OCT4, SOX2, NANOG, LIN28, c-MYC and KLF4. Pluripotency was confirmed both in vivo and in vitro. The transcriptome profile of epiHUVEC and the human embryonic stem cell line — H1 have a Pearson correlation of 0.899.

  2. Do Neural Cells Communicate with Endothelial Cells via Secretory Exosomes and Microvesicles?

    Directory of Open Access Journals (Sweden)

    Neil R. Smalheiser

    2009-01-01

    Full Text Available Neurons, glial, cells, and brain tumor cells tissues release small vesicles (secretory exosomes and microvesicles, which may represent a novel mechanism by which neuronal activity could influence angiogenesis within the embryonic and mature brain. If CNS-derived vesicles can enter the bloodstream as well, they may communicate with endothelial cells in the peripheral circulation and with cells concerned with immune surveillance.

  3. Epigallocatechin gallate inhibits endothelial exocytosis.

    Science.gov (United States)

    Yamakuchi, Munekazu; Bao, Clare; Ferlito, Marcella; Lowenstein, Charles J

    2008-07-01

    Consumption of green tea is associated with a decrease in cardiovascular mortality. The beneficial health effects of green tea are attributed in part to polyphenols, organic compounds found in tea that lower blood pressure, reduce body fat, decrease LDL cholesterol, and inhibit inflammation. We hypothesized that epigallocatechin gallate (EGCG), the most abundant polyphenol in tea, inhibits endothelial exocytosis, the initial step in leukocyte trafficking and vascular inflammation. To test this hypothesis, we treated human umbilical-vein endothelial cells with EGCG and other polyphenols, and then measured endothelial exocytosis. We found that EGCG decreases endothelial exocytosis in a concentration-dependent manner, with the effects most prominent after 4 h of treatment. Other catechin polyphenols had no effect on endothelial cells. By inhibiting endothelial exocytosis, EGCG decreases leukocyte adherence to endothelial cells. In searching for the mechanism by which EGCG affects endothelial cells, we found that EGCG increases Akt phosphorylation, eNOS phosphorylation, and nitric oxide (NO) production. NOS inhibition revealed that NO mediates the anti-inflammatory effects of EGCG. Our data suggest that polyphenols can decrease vascular inflammation by increasing the synthesis of NO, which blocks endothelial exocytosis.

  4. Gene expression profiling during murine tooth development

    Directory of Open Access Journals (Sweden)

    Maria A dos Santos silva Landin

    2012-07-01

    Full Text Available The aim of this study was to describe the expression of genes, including ameloblastin (Ambn, amelogenin X chromosome (Amelx and enamelin (Enam during early (pre-secretory tooth development. The expression of these genes has predominantly been studied at post-secretory stages. Deoxyoligonucleotide microarrays were used to study gene expression during development of the murine first molar tooth germ at 24h intervals, starting at the eleventh embryonic day (E11.5 and up to the seventh day after birth (P7. The profile search function of Spotfire software was used to select genes with similar expression profile as the enamel genes (Ambn, Amelx and Enam. Microarray results where validated using real-time Reverse Transcription-Polymerase Chain Reaction (real-time RT-PCR, and translated proteins identified by Western blotting. In situ localisation of the Ambn, Amelx and Enam mRNAs were monitored from E12.5 to E17.5 using deoxyoligonucleotide probes. Bioinformatics analysis was used to associate biological functions with differentially (p ≤0.05 expressed (DE genes.Microarray results showed a total of 4362 genes including Ambn, Amelx and Enam to be significant differentially expressed throughout the time-course. The expression of the three enamel genes was low at pre-natal stages (E11.5-P0 increasing after birth (P1-P7. Profile search lead to isolation of 87 genes with significantly similar expression to the three enamel proteins. The mRNAs expressed in dental epithelium and epithelium derived cells. Although expression of Ambn, Amelx and Enam were lower during early tooth development compared to secretory stages enamel proteins were detectable by Western blotting. Bioinformatic analysis associated the 87 genes with multiple biological functions. Around thirty-five genes were associated with fifteen transcription factors.

  5. Inhibition of Monocyte Adhesion to Brain-Derived Endothelial Cells by Dual Functional RNA Chimeras

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    Jing Hu

    2014-01-01

    Full Text Available Because adhesion of leukocytes to endothelial cells is the first step of vascular-neuronal inflammation, inhibition of adhesion and recruitment of leukocytes to vascular endothelial cells will have a beneficial effect on neuroinflammatory diseases. In this study, we used the pRNA of bacteriophage phi29 DNA packaging motor to construct a novel RNA nanoparticle for specific targeting to transferrin receptor (TfR on the murine brain-derived endothelial cells (bEND5 to deliver ICAM-1 siRNA. This RNA nanoparticle (FRS-NPs contained a FB4 aptamer targeting to TfR and a siRNA moiety for silencing the intercellular adhesion molecule-1 (ICAM-1. Our data indicated that this RNA nanoparticle was delivered into murine brain-derived endothelial cells. Furthermore, the siRNA was released from the FRS-NPs in the cells and knocked down ICAM-1 expression in the TNF-α–stimulated cells and in the cells under oxygen-glucose deprivation/reoxygenation (OGD/R condition. The functional end points of the study indicated that FRS-NPs significantly inhibited monocyte adhesion to the bEND5 cells induced by TNF-α and OGD/R. In conclusion, our approach using RNA nanotechnology for siRNA delivery could be potentially applied for inhibition of inflammation in ischemic stroke and other neuroinflammatory diseases, or diseases affecting endothelium of vasculature.

  6. Transcriptional interference among the murine beta-like globin genes.

    Science.gov (United States)

    Hu, Xiao; Eszterhas, Susan; Pallazzi, Nicolas; Bouhassira, Eric E; Fields, Jennifer; Tanabe, Osamu; Gerber, Scott A; Bulger, Michael; Engel, James Douglas; Groudine, Mark; Fiering, Steven

    2007-03-01

    Mammalian beta-globin loci contain multiple genes that are activated at different developmental stages. Studies have suggested that the transcription of one gene in a locus can influence the expression of the other locus genes. The prevalent model to explain this transcriptional interference is that all potentially active genes compete for locus control region (LCR) activity. To investigate the influence of transcription by the murine embryonic genes on transcription of the other beta-like genes, we generated mice with deletions of the promoter regions of Ey and betah1 and measured transcription of the remaining genes. Deletion of the Ey and betah1 promoters increased transcription of betamajor and betaminor 2-fold to 3-fold during primitive erythropoiesis. Deletion of Ey did not affect betah1 nor did deletion of betah1 affect Ey, but Ey deletion uniquely activated transcription from betah0, a beta-like globin gene immediately downstream of Ey. Protein analysis showed that betah0 encodes a translatable beta-like globin protein that can pair with alpha globin. The lack of transcriptional interference between Ey and betah1 and the gene-specific repression of betah0 did not support LCR competition among the embryonic genes and suggested that direct transcriptional interference from Ey suppressed betah0.

  7. Induction of initial steps of angiogenic differentiation and maturation of endothelial cells by pericytes in vitro and the role of collagen IV.

    Science.gov (United States)

    Zhou, Zhigang; Pausch, Friederike; Schlötzer-Schrehardt, Ursula; Brachvogel, Bent; Pöschl, Ernst

    2016-05-01

    Activation of endothelial cells and recruitment of mural cells define critical steps during the formation of stable vascular elements. Both events are reflected by cocultures of endothelial cells and isolated murine pericyte-like cells and define a versatile platform for the analysis of distinct steps during the angiogenic process in vitro. Isolated pericyte-like cells promote the survival of endothelial cells, induce the assembly of endothelial cells as well as establish direct contacts with forming endothelial alignments. More importantly, they also induce characteristic steps of maturation including the assembly of stable cell-cell junctions, deposition of basement membrane-like matrices and local formation of a central lumen. The presence of pericyte-like cells induces the secretion of extracellular matrices enriched in collagen IV by endothelial cells, which improves endothelial tube formation and provides the adhesive substrate for mural cell recruitment. Collagen-binding integrins contribute differentially to the process, with α1β1 involved in the adhesion of pericyte-like cells to collagen IV and α2β1 mainly involved in endothelial cord formation. These data indicate that pericyte-like cells are essential for the survival of endothelial cells, the efficient formation of endothelial alignments as well as initial steps of maturation of capillary-like structures.

  8. Nanomechanics and sodium permeability of endothelial surface layer modulated by hawthorn extract WS 1442.

    Directory of Open Access Journals (Sweden)

    Wladimir Peters

    Full Text Available The endothelial glycocalyx (eGC plays a pivotal role in the physiology of the vasculature. By binding plasma proteins, the eGC forms the endothelial surface layer (ESL which acts as an interface between bloodstream and endothelial cell surface. The functions of the eGC include mechanosensing of blood flow induced shear stress and thus flow dependent vasodilation. There are indications that levels of plasma sodium concentrations in the upper range of normal and beyond impair flow dependent regulation of blood pressure and may therefore increase the risk for hypertension. Substances, therefore, that prevent sodium induced endothelial dysfunction may be attractive for the treatment of cardiovascular disease. By means of combined atomic force-epifluorescence microscopy we studied the impact of the hawthorn (Crataegus spp. extract WS 1442, a herbal therapeutic with unknown mechanism of action, on the mechanics of the ESL of ex vivo murine aortae. Furthermore, we measured the impact of WS 1442 on the sodium permeability of endothelial EA.hy 926 cell monolayer. The data show that (i the ESL contributes by about 11% to the total endothelial barrier resistance for sodium and (ii WS 1442 strengthens the ESL resistance for sodium up to about 45%. This mechanism may explain some of the vasoprotective actions of this herbal therapeutic.

  9. In Vitro Endothelialization Test of Biomaterials Using Immortalized Endothelial Cells.

    Directory of Open Access Journals (Sweden)

    Ken Kono

    Full Text Available Functionalizing biomaterials with peptides or polymers that enhance recruitment of endothelial cells (ECs can reduce blood coagulation and thrombosis. To assess endothelialization of materials in vitro, primary ECs are generally used, although the characteristics of these cells vary among the donors and change with time in culture. Recently, primary cell lines immortalized by transduction of simian vacuolating virus 40 large T antigen or human telomerase reverse transcriptase have been developed. To determine whether immortalized ECs can substitute for primary ECs in material testing, we investigated endothelialization on biocompatible polymers using three lots of primary human umbilical vein endothelial cells (HUVEC and immortalized microvascular ECs, TIME-GFP. Attachment to and growth on polymer surfaces were comparable between cell types, but results were more consistent with TIME-GFP. Our findings indicate that TIME-GFP is more suitable for in vitro endothelialization testing of biomaterials.

  10. Epigenetic influence on embryonic development

    DEFF Research Database (Denmark)

    Donkin, Ida; Barrès, Romain; Pinborg, Anja

    2016-01-01

    The epigenome is sensitive to environmental changes and can sustainably alter gene expression, notably during embryonic development. New research indicates that epigenetic factors are heritable, which is why paternal lifestyle may affect fetal development and risk of disease. Children conceived...... by assisted reproduction technology (ART) have an increased risk of peri- and postnatal complications, and as specific ART protocols associate with specific risk profiles, the procedures themselves may cause epigenetic changes contributing to the altered outcomes of the 5,000 Danish children annually...

  11. Endothelial dysfunction: EDCF revisited

    Institute of Scientific and Technical Information of China (English)

    PAUL M Vanhoutte

    2008-01-01

    Endothelial cells can initiate contraction (constriction) of the vascular smooth muscle cells that surround them. Such endothelium-dependent, acute increases in contractile tone can be due to the withdrawal of the production of nitric oxide, to the production of vasoconstrictor peptides (angiotensin Ⅱ, endothelin-1), to the formation of oxygen-derived free radicals(superoxide anions) and/or the release of vasoconstrictor metabolites of arachidonic acid. The latter have been termed endothelium-derived contracting factor (EDCF) as they can contribute to moment-to-moment changes in contractile activity of the underlying vascular smooth muscle cells. To judge from animal experiments, EDCF-mediated responses are exacerbated when the production of nitric oxide is impaired as well as by aging, spontaneous hypertension and diabetes. To judge from human studies, they contribute to the blunting of endothelium-dependent vasodilatations in aged subjects and essential hypertensive patients. Since EDCF causes vasoconstriction by activation of the TP-receptors on the vascular smooth muscle cells, selective antagonists at these receptors prevent endothelium-dependent contractions, and curtail the endothelial dysfunction in hypertension and diabetes.

  12. The endothelial border to health

    DEFF Research Database (Denmark)

    Hansen, Nina Wærling; Hansen, Anker Jon; Sams, Anette

    2017-01-01

    The endothelial cell (EC) layer constitutes a barrier that controls movements of fluid, solutes and cells between blood and tissue. Further, the endothelial layer regulates vascular tone and directs local humoral and cellular inflammatory processes. The strategic position makes it an important...... for several endothelial dysfunctions. There is also mounting epidemiological evidence that dietary intake of refined sugars is important for the development of a number of diseases beyond obesity and type 2 diabetes. Various diseases involving inflammatory and immunological components are accelerated...... extracellular proteins form epitopes for potential specific antibody formation upon interactions with reducing sugars. This paper reviews the endothelial metabolism, biology, inflammatory processes, physical barrier functions, and summarizes evidence that although stochastic in nature, endothelial responses...

  13. Fbxw7 controls angiogenesis by regulating endothelial Notch activity.

    Directory of Open Access Journals (Sweden)

    Nanae Izumi

    Full Text Available Notch signaling controls fundamental aspects of angiogenic blood vessel growth including the selection of sprouting tip cells, endothelial proliferation and arterial differentiation. The E3 ubiquitin ligase Fbxw7 is part of the SCF protein complex responsible for the polyubiquitination and thereby proteasomal degradation of substrates such as Notch, c-Myc and c-Jun. Here, we show that Fbxw7 is a critical regulator of angiogenesis in the mouse retina and the zebrafish embryonic trunk, which we attribute to its role in the degradation of active Notch. Growth of retinal blood vessel was impaired and the Notch ligand Dll4, which is also a Notch target, upregulated in inducible and endothelial cell-specific Fbxw7(iECKO mutant mice. The stability of the cleaved and active Notch intracellular domain was increased after siRNA knockdown of the E3 ligase in cultured human endothelial cells. Injection of fbxw7 morpholinos interfered with the sprouting of zebrafish intersegmental vessels (ISVs. Arguing strongly that Notch and not other Fbxw7 substrates are primarily responsible for these phenotypes, the genetic inactivation of Notch pathway components reversed the impaired ISV growth in the zebrafish embryo as well as sprouting and proliferation in the mouse retina. Our findings establish that Fbxw7 is a potent positive regulator of angiogenesis that limits the activity of Notch in the endothelium of the growing vasculature.

  14. Murine inner cell mass-derived lineages depend on Sall4 function

    Science.gov (United States)

    Elling, Ulrich; Klasen, Christian; Eisenberger, Tobias; Anlag, Katrin; Treier, Mathias

    2006-01-01

    Sall4 is a mammalian Spalt transcription factor expressed by cells of the early embryo and germ cells, an expression pattern similar to that of both Oct4 and Sox2, which play essential roles during early murine development. We show that the activity of Sall4 is cell-autonomously required for the development of the epiblast and primitive endoderm from the inner cell mass. Furthermore, no embryonic or extraembryonic endoderm stem cell lines could be established from Sall4-deficient blastocysts. In contrast, neither the development of the trophoblast lineage nor the ability to generate trophoblast cell lines from murine blastocysts was impaired in the absence of Sall4. These data establish Sall4 as an essential transcription factor required for the early development of inner cell mass-derived cell lineages. PMID:17060609

  15. Hepatic Differentiation from Murine and Human iPS Cells Using Nanofiber Scaffolds.

    Science.gov (United States)

    Yamazoe, Taiji; Shiraki, Nobuaki; Kume, Shoen

    2016-01-01

    The induced pluripotent stem (iPS) cells of murine and human are capable to differentiate into any cell type of the body through recapitulating normal development, similarly as the embryonic stem (ES) cells. Lines of evidence support that both ES cells and iPS cells are induced to differentiate in vitro by sequential treatment of humoral cues such as growth factors and chemicals, combined with the use of certain microenvironments including extracellular matrices and scaffolds.Here, we describe the procedure to potentiate hepatic lineage cells differentiation from murine and human iPS cells, using growth factor cocktails and nanofiber scaffolds. Nanofiber scaffolds have a three-dimensional surface mimicking the fine structures of the basement membrane in vivo, allow the iPS cells to differentiate into the definitive endoderm and mature hepatocyte-like cells more efficiently than the two-dimensional conventional culture plates.

  16. Expression of vascular endothelial growth factor and its two receptors in normal human endometrium

    Institute of Scientific and Technical Information of China (English)

    王海燕; 陈贵安

    2003-01-01

    Objectives: We try to demonstrate the expression of vascular endothelial growthfactor (VEGF) and its receptors, flt-1 and KDR, in normal human emdometrium duringthe menstrual cycle.Methods: Immunohistochemical method was used to observe the expression ofVEGF and its two receptors in emdometrium throughout the normal menstrual cyclemeanwhile the isoforms of VEGF were also detected by Western blot analysis. The en-dothelial cells of micro-vessels were marked with Ⅷ factor antibody.Results: VEGF and its receptors existed in endometrial glandular, stromal and vas-cular endothelial cells of human endometrium. Their expressions were higher in the mid-secretory phase of menstrual cycle and highest at menstruation. VEGF121 and VEGF165were the predominant isoforms in normal human endometrium.Conclusion: The expression of VEGF and its two receptors showed cycle-dependentin human endometrium, probably involved in embryonic implantation and endometrialproliferation and differentiation.

  17. The Therapeutic Potential of Differentiated Lung Cells from Embryonic Stem Cells in Lung Diseases.

    Science.gov (United States)

    Mokhber Dezfouli, Mohammad Reza; Chaleshtori, Sirous Sadeghian; Dehghan, Mohammad Mehdi; Tavanaeimanesh, Hamid; Baharvand, Hossein; Tahamtani, Yaser

    2017-01-01

    Lung diseases cause great morbidity and mortality. The choice of effective medical treatment is limited and the number of lung diseases are difficult to treat with current treatments. The embryonic stem cells (ESCs) have the potential to differentiate into cell types of all three germinal layers, including lung epithelial cells. So they can be a potential source for new cell therapies for hereditary or acquired diseases of the airways and lungs. One method for treatment of lung diseases is cell therapy and the use of ESCs that can replace the damaged epithelial and endothelial cells. Progress using ESCs has developed slowly for lung regeneration because differentiation of lung cells from ESCs is more difficult as compared to differentiation of other cells. The review studies the therapeutic effects of differentiated lung cells from embryonic stem cells in lung diseases. There are few studies of differentiation of ESCs into a lineage of respiratory and then investigation of this cell in experimental model of lung diseases.

  18. Embryonic anti-aging niche.

    Science.gov (United States)

    Conboy, Irina M; Yousef, Hanadie; Conboy, Michael J

    2011-05-01

    Although functional organ stem cells persist in the old, tissue damage invariably overwhelms tissue repair, ultimately causing the demise of an organism. The poor performance of stem cells in an aged organ, such as skeletal muscle, is caused by the changes in regulatory pathways such as Notch, MAPK and TGF-β, where old differentiated tissue actually inhibits its own regeneration. This perspective analyzes the current literature on regulation of organ stem cells by their young versus old niches and suggests that determinants of healthy and prolonged life might be under a combinatorial control of cell cycle check point proteins and mitogens, which need to be tightly balanced in order to promote tissue regeneration without tumor formation. While responses of adult stem cells are regulated extrinsically and age-specifically, we put forward experimental evidence suggesting that embryonic cells have an intrinsic youthful barrier to aging and produce soluble pro-regenerative proteins that signal the MAPK pathway for rejuvenating myogenesis. Future identification of this activity will improve our understanding of embryonic versus adult regulation of tissue regeneration suggesting novel strategies for organ rejuvenation. Comprehensively, the current intersection of aging and stem cell science indicates that if the age-imposed decline in the regenerative capacity of stem cells was understood, the debilitating lack of organ maintenance in the old could be ameliorated and perhaps, even reversed.

  19. Vertebrate Embryonic Cleavage Pattern Determination.

    Science.gov (United States)

    Hasley, Andrew; Chavez, Shawn; Danilchik, Michael; Wühr, Martin; Pelegri, Francisco

    2017-01-01

    The pattern of the earliest cell divisions in a vertebrate embryo lays the groundwork for later developmental events such as gastrulation, organogenesis, and overall body plan establishment. Understanding these early cleavage patterns and the mechanisms that create them is thus crucial for the study of vertebrate development. This chapter describes the early cleavage stages for species representing ray-finned fish, amphibians, birds, reptiles, mammals, and proto-vertebrate ascidians and summarizes current understanding of the mechanisms that govern these patterns. The nearly universal influence of cell shape on orientation and positioning of spindles and cleavage furrows and the mechanisms that mediate this influence are discussed. We discuss in particular models of aster and spindle centering and orientation in large embryonic blastomeres that rely on asymmetric internal pulling forces generated by the cleavage furrow for the previous cell cycle. Also explored are mechanisms that integrate cell division given the limited supply of cellular building blocks in the egg and several-fold changes of cell size during early development, as well as cytoskeletal specializations specific to early blastomeres including processes leading to blastomere cohesion. Finally, we discuss evolutionary conclusions beginning to emerge from the contemporary analysis of the phylogenetic distributions of cleavage patterns. In sum, this chapter seeks to summarize our current understanding of vertebrate early embryonic cleavage patterns and their control and evolution.

  20. Embryonic Development: Chicken and Zebrafish

    Directory of Open Access Journals (Sweden)

    Veerle M. Darras

    2011-01-01

    Full Text Available Chicken and zebrafish are two model species regularly used to study the role of thyroid hormones in vertebrate development. Similar to mammals, chickens have one thyroid hormone receptor α (TRα and one TRβ gene, giving rise to three TR isoforms: TRα, TRβ2, and TRβ0, the latter with a very short amino-terminal domain. Zebrafish also have one TRβ gene, providing two TRβ1 variants. The zebrafish TRα gene has been duplicated, and at least three TRα isoforms are expressed: TRαA1-2 and TRαB are very similar, while TRαA1 has a longer carboxy-terminal ligand-binding domain. All these TR isoforms appear to be functional, ligand-binding receptors. As in other vertebrates, the different chicken and zebrafish TR isoforms have a divergent spatiotemporal expression pattern, suggesting that they also have distinct functions. Several isoforms are expressed from the very first stages of embryonic development and early chicken and zebrafish embryos respond to thyroid hormone treatment with changes in gene expression. Future studies in knockdown and mutant animals should allow us to link the different TR isoforms to specific processes in embryonic development.

  1. Differentiation of embryonic stem cells transfected by ibeB gene

    Institute of Scientific and Technical Information of China (English)

    SHANG Deshu; FANG Wengang; CHEN Yuhua

    2005-01-01

    We have previously identified an E. coli deter- minant, ibeB gene locus contributing to invasion of human brain microvascular endothelial cells. In the present study, we established embryonic stem (ES) cell lines overexpressing IbeB and found that exogenic ibeB gene could start-up expression of a neural stem cell specific marker, nestin, and give rise to polar changes. In analysis of IbeB location, it was found that GFP-IbeB fusion protein targeted at the ES cell nucleus. These data suggests that ibeB gene may play an important role in the regulation of nestin expression.

  2. ETS transcription factors in embryonic vascular development.

    Science.gov (United States)

    Craig, Michael P; Sumanas, Saulius

    2016-07-01

    At least thirteen ETS-domain transcription factors are expressed during embryonic hematopoietic or vascular development and potentially function in the formation and maintenance of the embryonic vasculature or blood lineages. This review summarizes our current understanding of the specific roles played by ETS factors in vasculogenesis and angiogenesis and the implications of functional redundancies between them.

  3. BMP2-SMAD signaling represses the proliferation of embryonic neural stem cells through YAP.

    Science.gov (United States)

    Yao, Minghui; Wang, Yadong; Zhang, Peng; Chen, Hong; Xu, Zhiheng; Jiao, Jianwei; Yuan, Zengqiang

    2014-09-03

    Previous studies have shown that the Hippo pathway effector yes-associated protein (YAP) plays an important role in maintaining stem cell proliferation. However, the precise molecular mechanism of YAP in regulating murine embryonic neural stem cells (NSCs) remains largely unknown. Here, we show that bone morphogenetic protein-2 (BMP2) treatment inhibited the proliferation of mouse embryonic NSCs, that YAP was critical for mouse NSC proliferation, and that BMP2 treatment-induced inhibition of mouse NSC proliferation was abrogated by YAP knockdown, indicating that the YAP protein mediates the inhibitory effect of BMP2 signaling. Additionally, we found that BMP2 treatment reduced YAP nuclear translocation, YAP-TEAD interaction, and YAP-mediated transactivation. BMP2 treatment inhibited YAP/TEAD-mediated Cyclin D1 (ccnd1) expression, and knockdown of ccnd1 abrogated the BMP2-mediated inhibition of mouse NSC proliferation. Mechanistically, we found that Smad1/4, effectors of BMP2 signaling, competed with YAP for the interaction with TAED1 and inhibited YAP's cotranscriptional activity. Our data reveal mechanistic cross talk between BMP2 signaling and the Hippo-YAP pathway in murine NSC proliferation, which may be exploited as a therapeutic target in neurodegenerative diseases and aging.

  4. Endothelial dysfunction in morbid obesity.

    Science.gov (United States)

    Mauricio, Maria Dolores; Aldasoro, Martin; Ortega, Joaquin; Vila, José María

    2013-01-01

    Morbid obesity is a chronic multifunctional disease characterized by an accumulation of fat. Epidemiological studies have shown that obesity is associated with cardiovascular and metabolic disorders. Endothelial dysfunction, as defined by an imbalance between relaxing and contractile endothelial factors, plays a central role in the pathogenesis of these cardiometabolic diseases. Diminished bioavailability of nitric oxide (NO) contributes to endothelial dysfunction and impairs endothelium- dependent vasodilatation. But this is not the only mechanism that drives to endothelial dysfunction. Obesity has been associated with a chronic inflammatory process, atherosclerosis, and oxidative stress. Moreover levels of asymmetrical dimethyl-L-arginine (ADMA), an endogenous inhibitor of endothelial nitric oxide synthase (eNOS), are elevated in obesity. On the other hand, increasing prostanoid-dependent vasoconstriction and decreasing vasodilator prostanoids also lead to endothelial dysfunction in obesity. Other mechanisms related to endothelin-1 (ET-1) or endothelium derived hyperpolarizing factor (EDHF) have been proposed. Bariatric surgery (BS) is a safe and effective means to achieve significant weight loss, but its use is limited only to patients with severe obesity including morbid obesity. BS also proved efficient in endothelial dysfunction reduction improving cardiovascular and metabolic comorbidities associated with morbid obesity such as diabetes, coronary artery disease, nonalcoholic fatty liver disease and cancer. This review will provide a brief overview of the mechanisms that link obesity with endothelial dysfunction, and how weight loss is a cornerstone treatment for cardiovascular comorbidities obesity-related. A better understanding of the mechanisms of obesity-induced endothelial dysfunction may help develop new therapeutic strategies to reduce cardiovascular morbidity and mortality.

  5. IL-1 beta and TGF beta 2 synergistically induce endothelial to mesenchymal transition in an NF kappa B-dependent manner

    NARCIS (Netherlands)

    Maleszewska, Monika; Moonen, Jan-Renier A. J.; Huijkman, Nicolette; van de Sluis, Bart; Krenning, Guido; Harmsen, Martin C.

    2013-01-01

    Endothelial to mesenchymal transition (EndMT) contributes to fibrotic diseases. The main inducer of EndMT is TGF beta signaling. TGF beta 2 is the dominant isoform in the physiological embryonic EndMT, but its role in the pathological EndMT in the context of inflammatory co-stimulation is not known.

  6. Pluripotent Embryonic Stem Cells Developed into Medulloepithelioma in Nude Mice Eyes

    Institute of Scientific and Technical Information of China (English)

    Yongping Li; Xiufeng Zhong; Jianhua Yan; Jianxian Lin; Song Tang; Xuan Wu; Shulong Li; Guanguang Feng; Yuzhen Yi

    2002-01-01

    Purpose: The pluripotent embryonic stem cells can differentiate into various kinds offormal tissues. There is no previous report on the differentiation of embryonic stem cellin the intraocular environment. In this paper, the authors tried to investigate theintraocular growth character of mice embryonic stem cells in nude mice.Methods: Murine embryonic stem cells were cultured and maintained in anundifferentiated state in vitro. They were transplanted into the right eyes of 20 nude miceby microinjection under operating microscope. Animal eye observation, light microscopeand immunohistochemical examinations were implemented.Results: Two to three days after transplantation, small pieces of gray-white materialcould be viewed in the vitreous cavity. Between the 15th and 20th day, the gray-whitemass grew into the anterior chamber in 4 nude mice eyes. Then, the mass at the anteriorchamber extended extraocularly. On the 30th day, a remarkable proptosis was observedin two of the four nude mice. In 6 to 45 days, the mice were executed for morphologicalexamination which showed the following typical structures: (1) Undifferentiated cellswith prominent nucleolius. (2) Flexner-Wintersteiner-like rosettes. (3) Medulloepithe-lioma-like structure: the cells were arranged in sheets, cords, tubes, and cysts. (4) Large,spindle-or astrocyte-like cells. (5) Cartilage-like structure. Immunohistochemically, mostof the cells were highly positive in NSE staining and a few cells were moderately positivein GFAP staining.Conclusions: Both animal eye findings and morphologic examinations certificated thatthe transplanted embryonic stem cells could grow in the eyes of nude mice anddifferentiate into intraocular medulloepithelioma.

  7. Characterization of microRNAs involved in embryonic stem cell states.

    Science.gov (United States)

    Stadler, Bradford; Ivanovska, Irena; Mehta, Kshama; Song, Sunny; Nelson, Angelique; Tan, Yunbing; Mathieu, Julie; Darby, Christopher; Blau, C Anthony; Ware, Carol; Peters, Garrick; Miller, Daniel G; Shen, Lanlan; Cleary, Michele A; Ruohola-Baker, Hannele

    2010-07-01

    Studies of embryonic stem cells (ESCs) reveal that these cell lines can be derived from differing stages of embryonic development. We analyzed common changes in the expression of microRNAs (miRNAs) and mRNAs in 9 different human ESC (hESC) lines during early commitment and further examined the expression of key ESCenriched miRNAs in earlier developmental states in several species. We show that several previously defined hESC-enriched miRNA groups (the miR-302, -17, and -515 families, and the miR-371-373 cluster) and several other hESC-enriched miRNAs are down-regulated rapidly in response to differentiation. We further found that mRNAs up-regulated upon differentiation are enriched in potential target sites for these hESC-enriched miRNAs. Interestingly, we also observed that the expression of ESC-enriched miRNAs bearing identical seed sequences changed dynamically while the cells transitioned through early embryonic states. In human and monkey ESCs, as well as human-induced pluripotent stem cells (iPSCs), the miR-371-373 cluster was consistently up-regulated, while the miR-302 family was mildly down-regulated when the cells were chemically treated to regress to an earlier developmental state. Similarly, miR-302b, but not mmu-miR-295, was expressed at higher levels in murine epiblast stem cells (mEpiSC) as compared with an earlier developmental state, mouse ESCs. These results raise the possibility that the relative expression of related miRNAs might serve as diagnostic indicators in defining the developmental state of embryonic cells and other stem cell lines, such as iPSCs. These data also raise the possibility that miRNAs bearing identical seed sequences could have specific functions during separable stages of early embryonic development.

  8. Mechanisms of embryonic stomach development.

    Science.gov (United States)

    McCracken, Kyle W; Wells, James M

    2017-06-01

    The stomach is a digestive organ that has important roles in human physiology and pathophysiology. The developmental origin of the stomach is the embryonic foregut, which also gives rise a number of other structures. There are several signaling pathways and transcription factors that are known to regulate stomach development at different stages, including foregut patterning, stomach specification, and gastric regionalization. These developmental events have important implications in later homeostasis and disease in the adult stomach. Here we will review the literature that has shaped our current understanding of the molecular mechanisms that coordinate gastric organogenesis. Further we will discuss how developmental paradigms have guided recent efforts to differentiate stomach tissue from pluripotent stem cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Human embryonic stem cells handbook

    Directory of Open Access Journals (Sweden)

    Carlo Alberto Redi

    2013-03-01

    Full Text Available After the Nobel prize in physiology or medicine was awarded jointly to Sir John Gurdon and Shinya Yamanaka for the discovery that mature cells can be reprogrammed to become pluripotent it became imperative to write down the review for a book entirely devoted to human embryonic stem cells (hES, those cells that are a urgent need for researchers, those cells that rekindle the ethical debates and finally, last but not least, those cells whose study paved the way to obtain induced pluripotent stem cells by the OSKC’s Yamanaka method (the OSKC acronim refers, for those not familiar with the topic, to the four stemness genes used to transfect somatic fibroblasts: Oct4, Sox2, Klf4 and c-Myc....

  10. Murine gamma interferon fails to inhibit Toxoplasma gondii growth in murine fibroblasts.

    Science.gov (United States)

    Schwartzman, J D; Gonias, S L; Pfefferkorn, E R

    1990-01-01

    Although treatment of human macrophages or fibroblasts with human gamma interferon results in the inhibition of intracellular Toxoplasma gondii, murine gamma interferon stimulated only murine macrophages, not murine fibroblasts, to inhibit T. gondii. This species difference may be important in understanding the control of acute and chronic toxoplasmosis. PMID:2106497

  11. Inhibitory Phosphorylation of Separase Is Essential for Genome Stability and Viability of Murine Embryonic Germ Cells

    Science.gov (United States)

    Huang, Xingxu; Andreu-Vieyra, Claudia V; York, J. Philippe; Hatcher, Rashieda; Lu, Tao; Matzuk, Martin M; Zhang, Pumin

    2008-01-01

    Activity of separase, a cysteine protease that cleaves sister chromatid cohesin at the onset of anaphase, is tightly regulated to ensure faithful chromosome segregation and genome stability. Two mechanisms negatively regulate separase: inhibition by securin and phosphorylation on serine 1121. To gauge the physiological significance of the inhibitory phosphorylation, we created a mouse strain in which Ser1121 was mutated to Ala (S1121A). Here we report that this S1121A point mutation causes infertility in mice. We show that germ cells in the mutants are depleted during development. We further demonstrate that S1121A causes chromosome misalignment during proliferation of the postmigratory primordial germ cells, resulting in mitotic arrest, aneuploidy, and eventual cell death. Our results indicate that inhibitory phosphorylation of separase plays a critical role in the maintenance of sister chromatid cohesion and genome stability in proliferating postmigratory primordial germ cells. PMID:18232736

  12. Inhibitory phosphorylation of separase is essential for genome stability and viability of murine embryonic germ cells.

    Directory of Open Access Journals (Sweden)

    Xingxu Huang

    2008-01-01

    Full Text Available Activity of separase, a cysteine protease that cleaves sister chromatid cohesin at the onset of anaphase, is tightly regulated to ensure faithful chromosome segregation and genome stability. Two mechanisms negatively regulate separase: inhibition by securin and phosphorylation on serine 1121. To gauge the physiological significance of the inhibitory phosphorylation, we created a mouse strain in which Ser1121 was mutated to Ala (S1121A. Here we report that this S1121A point mutation causes infertility in mice. We show that germ cells in the mutants are depleted during development. We further demonstrate that S1121A causes chromosome misalignment during proliferation of the postmigratory primordial germ cells, resulting in mitotic arrest, aneuploidy, and eventual cell death. Our results indicate that inhibitory phosphorylation of separase plays a critical role in the maintenance of sister chromatid cohesion and genome stability in proliferating postmigratory primordial germ cells.

  13. TCDD AND EGF AFFECT MAPK PATHWAY ACTIVATION IN MURINE EMBRYONIC PALATE

    Science.gov (United States)

    Palatal fusion occurs on GD 14-15 in the mouse, accompanied by a decrease in EGF receptor (EGFR) at the medial edge of the palatal shelves. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induces cleft palate and maintains EGF and EGF receptor (EGFR) expression levels in the medial ed...

  14. Embryonic stem cells remain highly pluripotent following long term expansion as aggregates in suspension bioreactors.

    Science.gov (United States)

    zur Nieden, Nicole I; Cormier, Jaymi T; Rancourt, Derrick E; Kallos, Michael S

    2007-05-01

    Increasing attention has been drawn towards pluripotent embryonic stem cells (ESCs) and their potential use as the primary material in various tissue engineering applications. Successful clinical implementation of this technology would require a quality controlled reproducible culture system for the expansion of the cells to be used in the generation of functional tissues. Recently, we showed that suspension bioreactors could be used in the regulated large-scale expansion of highly pluripotent murine ESCs. The current study illustrates that these bioreactor protocols can be adapted for long term culture and that murine ESC cultures remain highly undifferentiated, when serially passaged in suspension bioreactors for extended periods. Flow cytometry analysis and gene expression profiles of several pluripotency markers, in addition to colony and embryoid body (EB) formation tests were conducted at the start and end of the experiment and all showed that the ESC cultures remained highly undifferentiated over extended culture time in suspension. In vivo teratoma formation and in vitro differentiation into neural, cardiomyocyte, osteoblast and chondrocyte lineages, performed at the end of the long term culture, further supported the presence of functional and undifferentiated ESCs in the expanded population. Overall, this system enables the controlled expansion of highly pluripotent murine ESC populations.

  15. Expression and Function of the Homeostatic Molecule Del-1 in Endothelial Cells and the Periodontal Tissue

    Directory of Open Access Journals (Sweden)

    Jieun Shin

    2013-01-01

    Full Text Available Developmental endothelial locus-1 (Del-1 is an endothelial cell-secreted protein that limits the recruitment of neutrophils by antagonizing the interaction between the LFA-1 integrin on neutrophils and the intercellular adhesion molecule (ICAM-1 on endothelial cells. Mice with genetic or age-associated Del-1 deficiency exhibit increased neutrophil infiltration in the periodontium resulting in inflammatory bone loss. Here we investigated additional novel mechanisms whereby Del-1 could interfere with neutrophil recruitment and inflammation. Treatment of human endothelial cells with Del-1 did not affect the expression of endothelial molecules involved in the leukocyte adhesion cascade (ICAM-1, VCAM-1, and E-selectin. Moreover, genetic or age-associated Del-1 deficiency did not significantly alter the expression of these adhesion molecules in the murine periodontium, further ruling out altered adhesion molecule expression as a mechanism whereby Del-1 regulates leukocyte recruitment. Strikingly, Del-1 inhibited ICAM-1-dependent chemokine release (CXCL2, CCL3 by neutrophils. Therefore, Del-1 could potentially suppress the amplification of inflammatory cell recruitment mediated through chemokine release by infiltrating neutrophils. Interestingly, Del-1 was itself regulated by inflammatory stimuli, which generally exerted opposite effects on adhesion molecule expression. The reciprocal regulation between Del-1 and inflammation may contribute to optimally balance the protective and the potentially harmful effects of inflammatory cell recruitment.

  16. Internalization of targeted quantum dots by brain capillary endothelial cells in vivo.

    Science.gov (United States)

    Paris-Robidas, Sarah; Brouard, Danny; Emond, Vincent; Parent, Martin; Calon, Frédéric

    2016-04-01

    Receptors located on brain capillary endothelial cells forming the blood-brain barrier are the target of most brain drug delivery approaches. Yet, direct subcellular evidence of vectorized transport of nanoformulations into the brain is lacking. To resolve this question, quantum dots were conjugated to monoclonal antibodies (Ri7) targeting the murine transferrin receptor. Specific transferrin receptor-mediated endocytosis of Ri7-quantum dots was first confirmed in N2A and bEnd5 cells. After intravenous injection in mice, Ri7-quantum dots exhibited a fourfold higher volume of distribution in brain tissues, compared to controls. Immunofluorescence analysis showed that Ri7-quantum dots were sequestered throughout the cerebral vasculature 30 min, 1 h, and 4 h post injection, with a decline of signal intensity after 24 h. Transmission electron microscopic studies confirmed that Ri7-quantum dots were massively internalized by brain capillary endothelial cells, averaging 37 ± 4 Ri7-quantum dots/cell 1 h after injection. Most quantum dots within brain capillary endothelial cells were observed in small vesicles (58%), with a smaller proportion detected in tubular structures or in multivesicular bodies. Parenchymal penetration of Ri7-quantum dots was extremely low and comparable to control IgG. Our results show that systemically administered Ri7-quantum dots complexes undergo extensive endocytosis by brain capillary endothelial cells and open the door for novel therapeutic approaches based on brain endothelial cell drug delivery.

  17. Human embryonic stem cell derivation and directed differentiation.

    Science.gov (United States)

    Trounson, A

    2005-01-01

    Human embryonic stem cells (hESCs) are produced from normal, chromosomally aneuploid and mutant human embryos, which are available from in vitro fertilisation (IVF) for infertility or preimplantation diagnosis. These hESC lines are an important resource for functional genomics, drug screening and eventually cell and gene therapy. The methods for deriving hESCs are well established and repeatable, and are relatively successful, with a ratio of 1:10 to 1:2 hESC lines established to embryos used. hESCs can be formed from morula and blastocyst-stage embryos and from isolated inner cell mass cell (ICM) clusters. The hESCs can be formed and maintained on mouse or human somatic cells in serum-free conditions, and for several passages in cell-free cultures. The hESCs can be transfected with DNA constructs. Their gene expression profiles are being described and immunological characteristics determined. They may be grown indefinitely in culture while maintaining their original karyotype but this must be confirmed from time to time. hESCs spontaneously differentiate in the absence of the appropriate cell feeder layer, when overgrown in culture and when isolated from the ESC colony. All three major embryonic lineages are produced in differentiating attachment cultures and in unattached embryoid bodies. Cell progenitors of interest can be identified by markers, expression of reporter genes and characteristic morphology, and the culture thereafter enriched for further culture to more mature cell types. The most advanced directed differentiation pathways have been developed for neural cells and cardiac muscle cells, but many other cell types including haematopoietic progenitors, endothelial cells, lung alveoli, keratinocytes, pigmented retinal epithelium, neural crest cells and motor neurones, hepatic progenitors and cells that have some markers of gut tissue and pancreatic cells have been produced. The prospects for regenerative medicine are significant and there is much

  18. Embryonic stem cell research: an ethical problem

    OpenAIRE

    Рамазанова, А.

    2014-01-01

    Embryonic stem cells offer hope for new therapies, but their use and research entail an ethical problem, which does not have a certain solution. Therefore, we can ask: What exactly are the ethical arguments? Why are they so tricky to resolve?Embryonic stem cell research poses a moral dilemma. It forces us to choose between two moral principles: The duty to prevent or alleviate suffering The duty to respect the value of human life To obtain embryonic stem cells, the early embryo has to be dest...

  19. Role of microglia in embryonic neurogenesis

    Science.gov (United States)

    Tong, Chih Kong

    2016-01-01

    Microglia begin colonizing the developing brain as early as embryonic day 9, prior to the emergence of neurons and other glia. Their ontogeny is also distinct from other central nervous system cells, as they derive from yolk sac hematopoietic progenitors and not neural progenitors. In this review, we feature these unique characteristics of microglia and assess the spatiotemporal similarities between microglia colonization of the central nervous system and embryonic neurogenesis. We also infer to existing evidence for microglia function from embryonic through to postnatal neurodevelopment to postulate roles for microglia in neurogenesis. PMID:27555616

  20. Differentiation of Embryonic Stem Cells into Neurons and Retina—like Structure in Nude Mice

    Institute of Scientific and Technical Information of China (English)

    LiYP; GeJ

    1999-01-01

    Purpose:To investigate the intraocular growth and biological characteristics of mice embryonic stem cells in nude mice.Methods:Murine embryonic stem cells(D3 cell line)were cultured and maintained in an undifferentiated state in vitro,then transplanted into the anterior chamber of nude mice.Mophological and immunohistochemical examinations were implemented.Results:Two to three days after transplantation,yellow-white floating granules,sheets and masses were seen inside the anterior chamber and vitreous cavity,and enlarged gradually,14-20days later,the mice were executed.Morphological examination showed that there were undifferentiated cells and some round or polygonal differentiated cells in anterior chamber and vitreous cavity.The morphology of these differentiated cells were similar to that of the retina.The cells were highly positive in NSE staining.Conclusion:The tranplanted embryonic stem cells cold grow in the eyes of nude mice with tendency to differentiate into neurons and retina-like structure.

  1. Evaluation of biological effects of intermediate frequency magnetic field on differentiation of embryonic stem cell

    Directory of Open Access Journals (Sweden)

    Sachiko Yoshie

    2016-01-01

    Full Text Available The embryotoxic effect of intermediate frequency (IF magnetic field (MF was evaluated using murine embryonic stem (ES cells and fibroblast cells based on the embryonic stem cell test (EST. The cells were exposed to 21 kHz IF–MF up to magnetic flux density of 3.9 mT during the cell proliferation process (7 days or the cell differentiation process (10 days during which an embryonic body differentiated into myocardial cells. As a result, there was no significant difference in the cell proliferation between sham- and IF–MF-exposed cells for both ES and fibroblast cells. Similarly, the ratio of the number of ES-derived cell aggregates differentiated to myocardial cells to total number of cell aggregates was not changed by IF–MF exposure. In addition, the expressions of a cardiomyocytes-specific gene, Myl2, and an early developmental gene, Hba-x, in the exposed cell aggregate were not altered. Since the magnetic flux density adopted in this study is much higher than that generated by an inverter of the electrical railway, an induction heating (IH cooktop, etc. in our daily lives, these results suggested that IF–MF in which the public is exposed to in general living environment would not have embryotoxic effect.

  2. Targeting NCK-Mediated Endothelial Cell Front-Rear Polarity Inhibits Neo-Vascularization

    Science.gov (United States)

    Dubrac, Alexandre; Genet, Gael; Ola, Roxana; Zhang, Feng; Pibouin-Fragner, Laurence; Han, Jinah; Zhang, Jiasheng; Thomas, Jean-Léon; Chedotal, Alain; Schwartz, Martin A.; Eichmann, Anne

    2015-01-01

    Background Sprouting angiogenesis is a key process driving blood vessel growth in ischemic tissues and an important drug target in a number of diseases, including wet macular degeneration and wound healing. Endothelial cells forming the sprout must develop front-rear polarity to allow sprout extension. The adaptor proteins Nck1 and 2 are known regulators of cytoskeletal dynamics and polarity, but their function in angiogenesis is poorly understood. Here we show that the Nck adaptors are required for endothelial cell front-rear polarity and migration downstream of the angiogenic growth factors VEGF-A and Slit2. Methods and Results Mice carrying inducible, endothelial-specific Nck1/2 deletions fail to develop front-rear polarized vessel sprouts and exhibit severe angiogenesis defects in the postnatal retina and during embryonic development. Inactivation of NCK1 and 2 inhibits polarity by preventing Cdc42 and Pak2 activation by VEGF-A and Slit2. Mechanistically, NCK binding to ROBO1 is required for both Slit2 and VEGF induced front-rear polarity. Selective inhibition of polarized endothelial cell migration by targeting Nck1/2 prevents hypersprouting induced by Notch or Bmp signaling inhibition, as well as pathological ocular neovascularization and wound healing. Conclusions These data reveal a novel signal integration mechanism involving NCK1/2, ROBO1/2 and VEGFR2 that controls endothelial cell front-rear polarity during sprouting angiogenesis. PMID:26659946

  3. Foxn1 is essential for vascularization of the murine thymus anlage.

    Science.gov (United States)

    Mori, Kazuya; Itoi, Manami; Tsukamoto, Noriyuki; Amagai, Takashi

    2010-01-01

    We addressed whether vascularization of the thymus anlage depends on Foxn1 expression. In the thymus anlagen of wild-type mice, CD31(+) endothelial cells are initially observed between epithelial cells on embryonic day (Ed)12.5 and form luminal structure on Ed13. VEGF are produced in epithelial cells and mesenchymal cells which invaginate in the epithelial region of the anlagen on Ed13. However, in the nude thymus anlagen, neither CD31(+) cells nor VEGF producing mesenchymal cells is detected in the epithelial region. The present results indicate that Foxn1 dependent epithelial development is essential for vascularization of the thymus anlagen.

  4. Radial keratotomy associated endothelial degeneration

    Directory of Open Access Journals (Sweden)

    Moshirfar M

    2012-02-01

    Full Text Available Majid Moshirfar, Andrew Ollerton, Rodmehr T Semnani, Maylon HsuJohn A Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT, USAPurpose: To describe the presentation and clinical course of eyes with a history of radial keratotomy (RK and varying degrees of endothelial degeneration.Methods: Retrospective case series were used.Results: Thirteen eyes (seven patients were identified with clinical findings of significant guttata and a prior history of RK. The mean age of presentation for cornea evaluation was 54.3 years (range: 38–72 years, averaging 18.7 years (range: 11–33 years after RK. The presentation of guttata varied in degree from moderate to severe. Best corrected visual acuity (BCVA ranged from 20/25 to 20/80. All patients had a history of bilateral RK, except one patient who did not develop any guttata in the eye without prior RK. No patients reported a family history of Fuch’s Dystrophy. One patient underwent a penetrating keratoplasty in one eye and a Descemet’s stripping automated endothelial keratoplasty (DSAEK in the other eye.Conclusions: RK may induce a spectrum of endothelial degeneration. In elderly patients, the findings of guttata may signify comorbid Fuch’s dystrophy in which RK incisions could potentially hasten endothelial decomposition. In these select patients with stable cornea topography and prior RK, DSAEK may successfully treat RK endothelial degeneration.Keywords: radial keratotomy, RK, Descemet’s stripping automated endothelial keratoplasty, DSAEK, guttata, endothelial degeneration, Fuch’s dystrophy

  5. Cortical network from human embryonic stem cells

    OpenAIRE

    2010-01-01

    Abstract The connection of embryonic stem cell technology and developmental biology provides valuable tools to decipher the mechanisms underlying human brain development and diseases, especially among neuronal populations, that are not readily available in primary cultures. It is obviously the case of neurons forming the human cerebral cortex. In the images that are presented, the neurons were generated in vitro from human embryonic stem cells via forebrain-like progenitors. Maintained in cul...

  6. C1-Inhibitor Decreases the Release of Vasculitis-Like Chemotactic Endothelial Microvesicles.

    Science.gov (United States)

    Mossberg, Maria; Ståhl, Anne-Lie; Kahn, Robin; Kristoffersson, Ann-Charlotte; Tati, Ramesh; Heijl, Caroline; Segelmark, Mårten; Leeb-Lundberg, L M Fredrik; Karpman, Diana

    2017-08-01

    The kinin system is activated during vasculitis and may contribute to chronic inflammation. C1-inhibitor is the main inhibitor of the kinin system. In this study, we investigated the presence of the kinin B1 receptor on endothelial microvesicles and its contribution to the inflammatory process. Compared with controls (n=15), patients with acute vasculitis (n=12) had markedly higher levels of circulating endothelial microvesicles, identified by flow cytometry analysis, and significantly more microvesicles that were positive for the kinin B1 receptor (Pmicrovesicles from wild-type cells, B1 receptor-positive microvesicles derived from transfected human embryonic kidney cells induced a significant neutrophil chemotactic effect, and a B1 receptor antagonist blocked this effect. Likewise, patient plasma induced neutrophil chemotaxis, an effect decreased by reduction of microvesicle levels and by blocking the B1 receptor. We used a perfusion system to study the effect of patient plasma (n=6) and control plasma (n=6) on the release of microvesicles from glomerular endothelial cells. Patient samples induced the release of significantly more B1 receptor-positive endothelial microvesicles than control samples, an effect abrogated by reduction of the microvesicles in the perfused samples. Perfusion of C1-inhibitor-depleted plasma over glomerular endothelial cells promoted excessive release of B1 receptor-positive endothelial microvesicles compared with normal plasma, an effect significantly decreased by addition of C1-inhibitor or B1 receptor-antagonist. Thus, B1 receptor-positive endothelial microvesicles may contribute to chronic inflammation by inducing neutrophil chemotaxis, and the reduction of these microvesicles by C1-inhibitor should be explored as a potential treatment for neutrophil-induced inflammation. Copyright © 2017 by the American Society of Nephrology.

  7. Hyperglycemic switch from mitochondrial nitric oxide to superoxide production in endothelial cells.

    Science.gov (United States)

    Brodsky, Sergey V; Gao, Shujuan; Li, Hong; Goligorsky, Michael S

    2002-11-01

    The accumulated ultrastructural and biochemical evidence is highly suggestive of the existence of mitochondrial nitric oxide (NO) synthase (mtNOS), where local production of NO regulates the electron transport along the respiratory chain. Here, the functional competence of mtNOS in situ in a living cell was examined using an intravital fluorescent NO indicator, 4,5-diaminofluorescein, employing a new procedure for loading it into the mitochondria to demonstrate local NO generation in undisrupted endothelial cells and in isolated mitochondria as well as in human embryonic kidney cells stably expressing endothelial NOS. With the use of this approach, we showed that endothelial cells incubated in the presence of high concentration of D-glucose (but not L-glucose) are characterized by the reduced NO synthetic function of mitochondria despite the unaltered abundance of the enzyme. In parallel, mitochondrial generation of superoxide was augmented in endothelial cells incubated in the presence of a high concentration of D-glucose. Both the NO generation and superoxide production in hyperglycemic environment could be restored to control levels by treating cells with a cell-permeable superoxide dismutase mimetic. In addition, enhanced mitochondrial superoxide production could be suppressed with an inhibitor of NOS in stimulated endothelial cells. In conclusion, the data 1) provide direct evidence of mitochondrial NO production in endothelial cells, 2) demonstrate its suppression and enhanced superoxide generation in hyperglycemic environment, and 3) provide evidence that "uncoupled" mtNOS represents an important source of superoxide anions in endothelial cells incubated in high glucose-containing medium.

  8. Murine fertilized ovum, blastomere and morula cells lacking SP phenotype

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In the field of stem cell research, SP (side population) phenotype is used to define the property that cells maintain a high efflux capability for some fluorescent dye, such as Hoechst 33342. Recently, many researches proposed that SP phenotype is a phenotype shared by some stem cells and some progenitor cells, and that SP phenotype is regarded as a candidate purification marker for stem cells. In this research, murine fertilized ova (including conjugate and single nucleus fertilized ova), 2-cell stage and 8-cell stage blastomeres, morulas and blastocysts were isolated and directly stained by Hoechst 33342 dye. The results show that fertilized ovum, blastomere and morula cells do not demonstrate any ability to efflux the dye. However, the inner cell mass (ICM) cells of blastocyst exhibit SP phenotype, which is consistent with the result of embryonic stem cells (ESCs) in vitro. These results indicate that the SP phenotype of ICM-derived ESCs is an intrinsic property and independent of the culture condition in vitro, and that SP phenotype is one of the characteristics of at least some pluripotent stem cells, but is not shared by totipotent stem cells. In addition, the result that the SP phenotype of ICM cells disappeared when the inhibitor verapamil was added into medium implies that the SP phenotype is directly associated with ABCG2. These results suggest that not all the stem cells demonstrate SP phenotype, and that SP phenotype might act as a purification marker for partial stem cells such as some pluripotent embryonic stem cells and multipotent adult stem cells, but not for all stem cells exampled by the totipotent stem cells in the very early stage of mouse embryos.

  9. Nuclear localization of Annexin A7 during murine brain development

    Directory of Open Access Journals (Sweden)

    Noegel Angelika A

    2005-04-01

    Full Text Available Abstract Background Annexin A7 is a member of the annexin protein family, which is characterized by its ability to interact with phospholipids in the presence of Ca2+-ions and which is thought to function in Ca2+-homeostasis. Results from mutant mice showed altered Ca2+-wave propagation in astrocytes. As the appearance and distribution of Annexin A7 during brain development has not been investigated so far, we focused on the distribution of Annexin A7 protein during mouse embryogenesis in the developing central nervous system and in the adult mouse brain. Results Annexin A7 is expressed in cells of the developing brain where a change in its subcellular localization from cytoplasm to nucleus was observed. In the adult CNS, the subcellular distribution of Annexin A7 depends on the cell type. By immunohistochemistry analysis Annexin A7 was detected in the cytosol of undifferentiated cells at embryonic days E5–E8. At E11–E15 the protein is still present in the cytosol of cells predominantly located in the ventricular germinative zone surrounding the lateral ventricle. Later on, at embryonic day E16, Annexin A7 in cells of the intermediate and marginal zone of the neopallium translocates to the nucleus. Neuronal cells of all areas in the adult brain present Annexin A7 in the nucleus, whereas glial fibrillary acidic protein (GFAP-positive astrocytes exhibit both, a cytoplasmic and nuclear staining. The presence of nuclear Annexin A7 was confirmed by extraction of the nucleoplasm from isolated nuclei obtained from neuronal and astroglial cell lines. Conclusion We have demonstrated a translocation of Annexin A7 to nuclei of cells in early murine brain development and the presence of Annexin A7 in nuclei of neuronal cells in the adult animal. The role of Annexin A7 in nuclei of differentiating and mature neuronal cells remains elusive.

  10. Tetranectin is a novel marker for myogenesis during embryonic development, muscle regeneration, and muscle cell differentiation in vitro

    DEFF Research Database (Denmark)

    Wewer, U M; Iba, K; Durkin, M E

    1998-01-01

    cells in dystrophic mdx mice. Murine C2C12 myogenic cells and pluripotent embryonic stem cells can undergo muscle cell differentiation in vitro. Tetranectin is not expressed in the undifferentiated myogenic cells, but during the progression of muscle differentiation, tetranectin mRNA is induced......Tetranectin, a plasminogen-binding protein with a C-type lectin domain, is found in both serum and the extracellular matrix. In the present study we report that tetranectin is closely associated with myogenesis during embryonic development, skeletal muscle regeneration, and muscle cell...... differentiation in vitro. We find that tetranectin expression coincides with muscle differentiation and maturation in the second half of gestation and further that tetranectin is enriched at the myotendinous and myofascial junctions. The tetranectin immunostaining declines after birth and no immunostaining...

  11. Radial keratotomy associated endothelial degeneration.

    Science.gov (United States)

    Moshirfar, Majid; Ollerton, Andrew; Semnani, Rodmehr T; Hsu, Maylon

    2012-01-01

    To describe the presentation and clinical course of eyes with a history of radial keratotomy (RK) and varying degrees of endothelial degeneration. Retrospective case series were used. Thirteen eyes (seven patients) were identified with clinical findings of significant guttata and a prior history of RK. The mean age of presentation for cornea evaluation was 54.3 years (range: 38-72 years), averaging 18.7 years (range: 11-33 years) after RK. The presentation of guttata varied in degree from moderate to severe. Best corrected visual acuity (BCVA) ranged from 20/25 to 20/80. All patients had a history of bilateral RK, except one patient who did not develop any guttata in the eye without prior RK. No patients reported a family history of Fuch's Dystrophy. One patient underwent a penetrating keratoplasty in one eye and a Descemet's stripping automated endothelial keratoplasty (DSAEK) in the other eye. RK may induce a spectrum of endothelial degeneration. In elderly patients, the findings of guttata may signify comorbid Fuch's dystrophy in which RK incisions could potentially hasten endothelial decomposition. In these select patients with stable cornea topography and prior RK, DSAEK may successfully treat RK endothelial degeneration.

  12. Mapping the global mRNA transcriptome during development of the murine first molar

    Directory of Open Access Journals (Sweden)

    Maria A. eLandin

    2015-02-01

    Full Text Available The main objective of this study was to map global gene expression in order to provide information about the populations of mRNA species participating in murine tooth development at 24 h intervals, starting at the eleventh embryonic day (E11.5 up to the seventh post-natal day (P7. The levels of RNA species expressed during murine tooth development were mesured using a total of 58 deoxyoligonucleotide microarrays. Microarray data was validated using real-time RT-PCR. Differentially expressed genes (p<0.05 were subjected to bioinformatic analysis to identify cellular activities significantly associated with these genes. Using ANOVA the microarray data yielded 4362 genes as being differentially expressed from the elleventh embryonic day (E11.5 up to seven days post-natal (P7, 1921 of these being genes without known functions. The remaining 2441 genes were subjected to further statistical analysis using a supervised procedure.Bioinformatic analysis results for each time-point studied suggests that the main molecular functions associated with genes expressed at the early pre-natal stages (E12.5-E18.5 studied were cell cycle progression, cell morphology, lipid metabolism, cellular growth, proliferation, senescence and apoptosis, whereas most genes expressed at post-natal and secretory stages (P0- P7 were significantly associated with regulation of cell migration, biosynthesis, differentiation, oxidative stress, polarization and cell death. Differentially expressed genes (DE not described earlier during murine tooth development; Inositol 1, 4, 5-triphosphate receptor 3 (Itpr3, metallothionein 1(Mt1, cyclin-dependent kinase 4 (Cdk4, cathepsin D (Ctsd, keratin complex 2, basic, gene 6a (Krt2-6a, cofilin 1, non-muscle (Cfl1, cyclin 2 (Ccnd2, were verified by real-time RT-PCR.

  13. Endothelial keratoplasty: evolution and horizons

    Directory of Open Access Journals (Sweden)

    Gustavo Teixeira Grottone

    2012-12-01

    Full Text Available Endothelial keratoplasty has been adopted by corneal surgeons worldwide as an alternative to penetrating keratoplasty (PK in the treatment of corneal endothelial disorders. Since the first surgeries in 1998, different surgical techniques have been used to replace the diseased endothelium. Compared with penetrating keratoplasty, all these techniques may provide faster and better visual rehabilitation with minimal change in refractive power of the transplanted cornea, minimal induced astigmatism, elimination of suture-induced complications and late wound dehiscence, and a reduced demand for postoperative care. Translational research involving cell-based therapy is the next step in work on endothelial keratoplasty. The present review updates information on comparisons among different techniques and predicts the direction of future treatment.

  14. Genetics of corneal endothelial dystrophies

    Indian Academy of Sciences (India)

    Chitra Kannabiran

    2009-12-01

    The corneal endothelium maintains the level of hydration in the cornea. Dysfunction of the endothelium results in excess accumulation of water in the corneal stroma, leading to swelling of the stroma and loss of transparency. There are four different corneal endothelial dystrophies that are hereditary, progressive, non-inflammatory disorders involving dysfunction of the corneal endothelium. Each of the endothelial dystrophies is genetically heterogeneous with different modes of transmission and/or different genes involved in each subtype. Genes responsible for disease have been identified for only a subset of corneal endothelial dystrophies. Knowledge of genes involved and their function in the corneal endothelium can aid understanding the pathogenesis of the disorder as well as reveal pathways that are important for normal functioning of the endothelium.

  15. Understanding high endothelial venules: Lessons for cancer immunology.

    Science.gov (United States)

    Ager, Ann; May, Michael J

    2015-06-01

    High endothelial venules (HEVs) are blood vessels especially adapted for lymphocyte trafficking which are normally found in secondary lymphoid organs such as lymph nodes (LN) and Peyer's patches. It has long been known that HEVs develop in non-lymphoid organs during chronic inflammation driven by autoimmunity, infection or allografts. More recently, HEVs have been observed in solid, vascularized tumors and their presence correlated with reduced tumor size and improved patient outcome. It is proposed that newly formed HEV promote antitumor immunity by recruiting naive lymphocytes into the tumor, thus allowing the local generation of cancerous tissue-destroying lymphocytes. Understanding how HEVs develop and function are therefore important to unravel their role in human cancers. In LN, HEVs develop during embryonic and early post-natal life and are actively maintained by the LN microenvironment. Systemic blockade of lymphotoxin-β receptor leads to HEV de-differentiation, but the LN components that induce HEV differentiation have remained elusive. Recent elegant studies using gene-targeted mice have demonstrated clearly that triggering the lymphotoxin-β receptor in endothelial cells (EC) induces the differentiation of HEV and that CD11c(+) dendritic cells play a crucial role in this process. It will be important to determine whether lymphotoxin-β receptor-dependent signaling in EC drives the development of HEV during tumorigenesis and which cells have HEV-inducer properties. This may reveal therapeutic approaches to promote HEV neogenesis and determine the impact of newly formed HEV on tumor immunity.

  16. Mapping the stem cell state: eight novel human embryonic stem and embryonal carcinoma cell antibodies

    DEFF Research Database (Denmark)

    Wright, A; Andrews, N; Bardsley, K

    2011-01-01

    The antigenic profile of human embryonic stem (ES) and embryonal carcinoma (EC) cells has served as a key element of their characterization, with a common panel of surface and intracellular markers now widely used. Such markers have been used to identify cells within the 'undifferentiated state...

  17. Plasma membrane proteomics of human embryonic stem cells and human embryonal carcinoma cells.

    NARCIS (Netherlands)

    Dormeyer, W.; van Hoof, D.; Braam, S.R.; Heck, A.J.R.; Mummery, C.L.; Krijgsveld, J.

    2008-01-01

    Human embryonic stem cells (hESCs) are of immense interest in regenerative medicine as they can self-renew indefinitely and can give rise to any adult cell type. Human embryonal carcinoma cells (hECCs) are the malignant counterparts of hESCs found in testis tumors. hESCs that have acquired chromosom

  18. A Novel Molecular and Functional Stemness Signature Assessing Human Cord Blood-Derived Endothelial Progenitor Cell Immaturity.

    Directory of Open Access Journals (Sweden)

    Oriane Guillevic

    Full Text Available Endothelial Colony Forming Cells (ECFCs, a distinct population of Endothelial Progenitor Cells (EPCs progeny, display phenotypic and functional characteristics of endothelial cells while retaining features of stem/progenitor cells. Cord blood-derived ECFCs (CB-ECFCs have a high clonogenic and proliferative potentials and they can acquire different endothelial phenotypes, this requiring some plasticity. These properties provide angiogenic and vascular repair capabilities to CB-ECFCs for ischemic cell therapies. However, the degree of immaturity retained by EPCs is still confused and poorly defined. Consequently, to better characterize CB-ECFC stemness, we quantified their clonogenic potential and demonstrated that they were reprogrammed into induced pluripotent stem cells (iPSCs more efficiently and rapidly than adult endothelial cells. Moreover, we analyzed the transcriptional profile of a broad gene panel known to be related to stem cells. We showed that, unlike mature endothelial cells, CB-ECFCs expressed genes involved in the maintenance of embryonic stem cell properties such as DNMT3B, GDF3 or SOX2. Thus, these results provide further evidence and tools to appreciate EPC-derived cell stemness. Moreover this novel stem cell transcriptional signature of ECFCs could help better characterizing and ranging EPCs according to their immaturity profile.

  19. A human ESC model for MLL-AF4 leukemic fusion gene reveals an impaired early hematopoietic-endothelial specification

    Institute of Scientific and Technical Information of China (English)

    Clara Bueno; Agustin F Femández; Mario F Fraga; Inmaculada Moreno-Gimeno; Deborah Burks; Maria del Carmen Plaza-Calonge; Juan C Rodríguez-Manzaneque; Pablo Menendez; Rosa Montes; Gustavo J Melen; Verónica Ramos-Mejia; Pedro J Real; Verónica Ayllón; Laura Sanchez; Gertrudis Ligero; Iván Gutierrez-Aranda

    2012-01-01

    The MLL-AF4 fusion gene is a hallmark genomic aberration in high-risk acute lymphoblastic leukemia in inants.Although it is well established that MLL-AF4 arises prenatally during human development,its effects on hematopoieric development in utero remain unexplored.We have created a human-specific cellular system to study early hemato-endothelial development in MLL-AF4-expressing human embryonic stem cells (hESCs).Functional studies,clonal analysis and gene expression profiling reveal that expression of MLL-AF4 in hESCs has a phenotypic,functional and gene expression impact.MLL-AF4 acts as a global transcriptional activator and a positive regulator of homeobox gene expression in hESCs.Functionally,MLL-AF4 enhances the specification of hemogenic precursors from hESCs but strongly impairs further hematopoietic commitment in favor of an endothelial cell fate.MLL-AF4 hESCs are transcriptionally primed to differentiate towards hemogenic precursors prone to endothelial maturation,as reflected by the marked upregulation of master genes associated to vascular-endothelial functions and early hematopoiesis.Furthermore,we report that MLL-AF4 expression is not sufficient to transform hESC-derived hematopoietic cells.This work illustrates how hESCs may provide unique insights into human development and further our understanding of how leukemic fusion genes,known to arise prenatally,regulate human embryonic hematopoietic specification.

  20. Flow cytometry of murine spermatocytes.

    Science.gov (United States)

    Gaysinskaya, Valeriya; Bortvin, Alex

    2015-04-01

    Protocols for purification of murine male germ cells by FACS based on Hoechst 33342 (Ho342) dye staining have been reported and optimized. However, the protocols are often challenging to follow, partly due to difficulties related to sample preparation, instrument parameters, data display, and selection strategies. In addition, troubleshooting of flow cytometry experiments usually requires some fluency in technical principles and instrument specifications and settings. This unit describes setup and procedures for analysis and sorting of male meiotic prophase I (MPI) cells and other germ cells. Included are procedures that guide data acquisition, display, gating, and back-gating critical for optimal data visualization and cell sorting. Additionally, a flow cytometry analysis of spermatogenesis-defective testis is provided to illustrate the applicability of the technique to the characterization and purification of cells from mutant testis.

  1. Murine models of ulcerative colitis.

    Science.gov (United States)

    Flynn, Christopher; Levine, Joel; Rosenberg, Daniel W

    2003-06-01

    Ulcerative colitis (UC) is an inflammatory bowel disease of unknown etiology limited to the large intestine. The disease is prevalent in industrial societies and is associated with specific ethnic populations. A number of murine models, each focused on distinct aspects of the disease process, were developed over the past 20 years to further our understanding of the pathogenesis of UC. These models have been and remain our best resource for the study of the disorder as a result of their homology to human UC and the ease in which they can be manipulated and examined. This review examines and distills what has been leamed from these models and how this information is related back to human UC.

  2. Cell interactions between hematopoietic and stromal cells in the embryonic chick bone marrow.

    Science.gov (United States)

    Sorrell, J M; Weiss, L

    1980-05-01

    Light microscopic, scanning electron microscopic, and transmission electron microscopic studies of the early developmental stages of chick embryonic bone marrow disclose characteristic associations of the first hematopoietic cells with stromal cells. The first hematopoietic cells, large basophilic cells that we have termed presumptive stem cells, segregate into erythropoietic and granulopoietic regions. Intravascular erythropoietic cells associate with sinusoidal endothelial cells, while granulopoietic cells associate with extravascular reticular cells. Extensive, intimate contacts between erythroid and endothelial cells are maintained, in part, by marginal arrays of microtubules, which promote a flattening of the adherent erythroid cell surface. In addition, cell surface components of opposing cells, visualized by ruthenium red staining, appear to merge and possibly to interact. Granulopoietic cells establish intimate but less extensive associations with reticular cells through cell-surface interactions. Stationary granuloid cells appear to be held in place by small, thin processes emanating from the sheet-like reticular cells. Granuloid cells are capable of moving within the extravascular region, using reticular cell surfaces as a substrate. Intimate associations also occur among granulopoietic cells, the significance of which is unclear. Thus, sinusoidal endothelial cells and reticular cells comprise the critical non-hematopoietic or stromal elements of avian bone marrow, where they have a putative role in segregating presumptive stem cells into erythrocyteic and granulocytic compartments. They serve as an architectual, and possibly regulatory, framework on which hematopoiesis occurs.

  3. Murine model of TB meningitis.

    Science.gov (United States)

    Gupta, Umesh Datta; Abbas, Ali; Kashyap, Raj Pal Singh; Gupta, Pushpa

    2016-12-01

    Central nervous system (CNS) infections caused by Mycobacterium tuberculosis (MTB) are the most severe forms of extrapulmonary TB (EPTB) due to high levels of mortality and neurological morbidity. Limited studies are available on CNS-TB animal-model development, despite the steady rise in cerebral-TB cases in India over the past decade. This study describes the development of a murine model of CNS-TB using a clinical strain (C3) isolated from the cerebrospinal fluid (CSF) of CNS-TB patients. Groups of mice were infected intravenously with an MTB C3 strain isolated from the CSF of CNS-TB patients in order to mimic the dynamics of actual infection. Brain and lung tissue were evaluated for bacterial burden, as well as histopathology and surrogate markers of TB infection at 30- and 50-days post-infection. Mice infected intravenously with MTB C3 strains showed progressive development of CNS disease, with high bacillary burden in the lungs during the initial stage (30days), which eventually disseminated to the brain at a later stage (50days). All C3-infected mice showed elevated levels of mycobacterial antigens and antibodies, as well as increased T cell adenosine deaminase activity in brain homogenates, which explicitly correlated with mycobacterial load in the brain and chronic brain pathology. High mortality rates (60%) were associated with mice infected with the C3 strain as compared to those of controls. Our findings demonstrated the design of a novel murine model of CNS-TB using a C3 strain and that replicated events of EPTB dissemination. This model will promote efforts to understand the pathogenesis CNS-TB infection for development of improved therapeutic interventions in the future. Copyright © 2016.

  4. Uncoupled embryonic and extra-embryonic tissues compromise blastocyst development after somatic cell nuclear transfer.

    Directory of Open Access Journals (Sweden)

    Séverine A Degrelle

    Full Text Available Somatic cell nuclear transfer (SCNT is the most efficient cell reprogramming technique available, especially when working with bovine species. Although SCNT blastocysts performed equally well or better than controls in the weeks following embryo transfer at Day 7, elongation and gastrulation defects were observed prior to implantation. To understand the developmental implications of embryonic/extra-embryonic interactions, the morphological and molecular features of elongating and gastrulating tissues were analysed. At Day 18, 30 SCNT conceptuses were compared to 20 controls (AI and IVP: 10 conceptuses each; one-half of the SCNT conceptuses appeared normal while the other half showed signs of atypical elongation and gastrulation. SCNT was also associated with a high incidence of discordance in embryonic and extra-embryonic patterns, as evidenced by morphological and molecular "uncoupling". Elongation appeared to be secondarily affected; only 3 of 30 conceptuses had abnormally elongated shapes and there were very few differences in gene expression when they were compared to the controls. However, some of these differences could be linked to defects in microvilli formation or extracellular matrix composition and could thus impact extra-embryonic functions. In contrast to elongation, gastrulation stages included embryonic defects that likely affected the hypoblast, the epiblast, or the early stages of their differentiation. When taking into account SCNT conceptus somatic origin, i.e. the reprogramming efficiency of each bovine ear fibroblast (Low: 0029, Med: 7711, High: 5538, we found that embryonic abnormalities or severe embryonic/extra-embryonic uncoupling were more tightly correlated to embryo loss at implantation than were elongation defects. Alternatively, extra-embryonic differences between SCNT and control conceptuses at Day 18 were related to molecular plasticity (high efficiency/high plasticity and subsequent pregnancy loss. Finally

  5. Generation of a conditional knockout of murine glucocerebrosidase: utility for the study of Gaucher disease.

    Science.gov (United States)

    Sinclair, Graham B; Jevon, Gareth; Colobong, Karen E; Randall, Derrick R; Choy, Francis Y M; Clarke, Lorne A

    2007-02-01

    Gaucher disease is a disorder of sphingolipid metabolism resulting from an inherited deficiency of the lysosomal hydrolase glucocerebrosidase. Affected individuals present with a spectrum of clinical symptoms ranging from hepatosplenomegaly, haematological abnormalities, and bone pain in type 1 disease, to severe neurodegeneration and premature death in types 2 and 3 disease. Although the basic biochemical defect is well characterized, there remains a poor understanding of the underlying pathophysiology of disease. In vitro studies suggest that macrophage glucocerebroside storage leads to tissue dysfunction through complex mechanisms involving altered intracellular calcium homeostasis and apoptosis. In order to study the pathogenic roles of these complex interactions, a viable animal model for Gaucher disease is needed. The complexity of this single gene disorder has been emphasized by the varied results of previous murine Gaucher models, ranging from perinatal lethality to phenotypically and biochemically asymptomatic animals. Recognizing the need to modulate the biochemical phenotype in mice to produce a relevant model, we have created a murine strain with key exons of the glucocerebrosidase gene flanked by loxP sites. We show that expression of Cre-recombinase in cells of hematopoietic and endothelial origin results in deficiency of glucocerebrosidase in the liver, spleen, bone marrow, and peripheral white cells. Glucocerebroside storage in this model leads to progressive splenomegaly with Gaucher cell infiltration and modest storage in the liver by 26 weeks of age. These results indicate the utility of this loxP GBA targeted murine strain for understanding the complex pathophysiology of Gaucher disease.

  6. Fatty acid extracts from Lucilia sericata larvae promote murine cutaneous wound healing by angiogenic activity

    Directory of Open Access Journals (Sweden)

    Zhang Jianing

    2010-03-01

    Full Text Available Abstract Background fatty acids are considered to be effective components to promote wound healing and Lucilia sericata larvae are applied clinically to treat intractable wounds. We aimed to investigat the effect of fatty acid extracts from dried Lucilia sericata larvae on murine cutaneuous wound healing as well as angiogenesis. Results On day 7 and 10 after murine acute excision wounds creation, the percent wound contraction of fatty acid extracts group was higher than that of vaseline group. On day 3, 7 and 10 after wounds creation, the wound healing quality of fatty acid extracts group was better than that of vaseline group on terms of granulation formation and collagen organization. On day 3 after wounds creation, the micro vessel density and vascular endothelial growth factor expression of fatty acid extracts group were higher than that of vaseline group. Component analysis of the fatty acid extracts by gas chromatography-mass spectrometry showed there were 10 kinds of fatty acids in total and the ratio of saturated fatty acid, monounsaturated fatty acid and polyunsaturated fatty acid (PUFA was: 20.57%:60.32%:19.11%. Conclusions Fatty acid extracts from dried Lucilia sericata larvae, four fifths of which are unsaturated fatty acids, can promote murine cutaneous wound healing probably resulting from the powerful angiogenic activity of the extracts.

  7. Endothelial cell adhesion and growth within a bioassay chamber using microstamped ECM proteins

    Science.gov (United States)

    Rubenstein, David A.; Frame, Mary D.

    2011-06-01

    Our goal was to evaluate microvascular endothelial cell growth on microstamped patterns of extracellular matrix proteins (ECM). A combination of photo- and soft-lithography was used to make features ˜100 μm deep and 150μm wide. Polydimethylsiloxane imprints of features produced positive molds used to stamp collagen I, IV, laminin and fibronectin onto cleaned hydrophilic or hydrophobic glass coverslips. Human dermal microvascular endothelial cells were seeded at an initial density of 800 cells cm-2, and cultured for three days. Explanted murine aortas, serving as an initial source for autologous endothelial cells, were perfused at 240 μL min-1 for 1 day. Cell morphology was also quantified on both the non-patterned glass and within the microstamped patterns. Viability was high (>90%) on all microstamped proteins, regardless of glass hydrophobicity. Viability was reduced on bare hydrophobic glass. Cell density was 4 or 8 fold higher on microstamped ECM proteins compared with hydrophilic or hydrophobic glass, respectively. Confluence was approached more rapidly on microstamped proteins. Thus, rapid concentrated growth of endothelial cells was markedly enhanced within microstamped ECM patterns on hydrophilic and hydrophobic glass.

  8. Graft stability after endothelial keratoplasty

    Directory of Open Access Journals (Sweden)

    Jovanović Vesna

    2015-01-01

    Full Text Available Bacground/Aim. Techniques for replacing the corneal endothelium have been improved. The host-graft interface is the key to graft adhesion and visual recovery. The aim of this study was to establish graft stability after Descemet stripping with endothelial keratoplasty (DSEK, compare it to the graft stability after endothelial keratoplasty with the intact posterior corneal layers (nDSEK in the rabbit cornea, and to investigate the nature of wound healing. Methods. Adult white rabbits (n = 20 were divided in two experimental groups: ten rabbits underwent monocular DSEK, and ten rabbits underwent endothelial keratoplasty without Descemet stripping (nDSEK. On the second postoperative day a horizontal dislocation of the graft was tried using the Lindstrom roller in each animal. Corneas were processed for the light microscopy study. Results. Rolling the Lindstrom instrument over the corneal surface did not cause horizontal dislocation in any of the operated eyes. In the DSEK group light microscopy revealed the lack of inflammation and fibrosis at the clearly distinctive donor-recipient interface (DRI. Retrocorneal membrane was found in two eyes. In nDSEK group, the host Descemet` s membrane (DM was intact without endothelial cells, with good graft apposition, without inflammation, fibrosis, or retrocorneal membrane. Conclusion. This study suggests that there is no difference in graft stability in DSEK compared to nDSEK in rabbit corneas. Wounds healed at DRI by hypocellular scarring only in both experimental groups.

  9. Human Embryonic Stem Cells Form Functional Thyroid Follicles

    Science.gov (United States)

    Latif, Rauf; Davies, Terry F.

    2015-01-01

    Objective: The molecular events that lead to human thyroid cell speciation remain incompletely characterized. It has been shown that overexpression of the regulatory transcription factors Pax8 and Nkx2-1 (ttf-1) directs murine embryonic stem (mES) cells to differentiate into thyroid follicular cells by initiating a transcriptional regulatory network. Such cells subsequently organized into three-dimensional follicular structures in the presence of extracellular matrix. In the current study, human embryonic stem (hES) cells were studied with the aim of recapitulating this scenario and producing functional human thyroid cell lines. Methods: Reporter gene tagged pEZ-lentiviral vectors were used to express human PAX8-eGFP and NKX2-1-mCherry in the H9 hES cell line followed by differentiation into thyroid cells directed by Activin A and thyrotropin (TSH). Results: Both transcription factors were expressed efficiently in hES cells expressing either PAX8, NKX2-1, or in combination in the hES cells, which had low endogenous expression of these transcription factors. Further differentiation of the double transfected cells showed the expression of thyroid-specific genes, including thyroglobulin (TG), thyroid peroxidase (TPO), the sodium/iodide symporter (NIS), and the TSH receptor (TSHR) as assessed by reverse transcription polymerase chain reaction and immunostaining. Most notably, the Activin/TSH-induced differentiation approach resulted in thyroid follicle formation and abundant TG protein expression within the follicular lumens. On stimulation with TSH, these hES-derived follicles were also capable of dose-dependent cAMP generation and radioiodine uptake, indicating functional thyroid epithelial cells. Conclusion: The induced expression of PAX8 and NKX2-1 in hES cells was followed by differentiation into thyroid epithelial cells and their commitment to form functional three-dimensional neo-follicular structures. The data provide proof of principal that hES cells can be

  10. PRDM6 is enriched in vascular precursors during development and inhibits endothelial cell proliferation, survival, and differentiation.

    Science.gov (United States)

    Wu, Yaxu; Ferguson, James E; Wang, Hong; Kelley, Rusty; Ren, Rongqin; McDonough, Holly; Meeker, James; Charles, Peter C; Wang, Hengbin; Patterson, Cam

    2008-01-01

    The mechanisms that regulate the differentiation program of multipotential stem cells remain poorly understood. In order to define the cues that delineate endothelial commitment from precursors, we screened for candidate regulatory genes in differentiating mouse embryoid bodies. We found that the PR/SET domain protein, PRDM6, is enriched in flk1(+) hematovascular precursor cells using a microarray-based approach. As determined by 5' RACE, full-length PRDM6 protein contains a PR domain and four Krüppel-like zinc fingers. In situ hybridization in mouse embryos demonstrates staining of the primitive streak, allantois, heart, outflow tract, paraaortic splanchnopleura (P-Sp)/aorto-gonadal-mesonephric (AGM) region and yolk sac, all sites known to be enriched in vascular precursor cells. PRDM6 is also detected in embryonic and adult-derived endothelial cell lines. PRDM6 is co-localized with histone H4 and methylates H4-K20 (but not H3) in vitro and in vivo, which is consistent with the known participation of PR domains in histone methyltransferase activity. Overexpression of PRDM6 in mouse embryonic endothelial cells induces apoptosis by activating caspase-3 and inducing G1 arrest. PRDM6 inhibits cell proliferation as determined by BrdU incorporation in endothelial cells, but not in rat aortic smooth muscle cells. Overexpression of PRDM6 also results in reduced tube formation in cultured endothelial cells grown in Matrigel. Taken together, our data indicate that PRDM6 is expressed by vascular precursors, has differential effects in endothelial cells and smooth muscle cells, and may play a role in vascular precursor differentiation and survival by modulating local chromatin-remodeling activity within hematovascular subpopulations during development.

  11. Endothelial dysfunction in diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Hadi AR Hadi

    2008-01-01

    Full Text Available Hadi AR Hadi, Jassim Al SuwaidiDepartment of Cardiology and Cardiovascular Surgery, Hamad General Hospital – Hamad Medical Corporation, Doha, State of Qatar; Department of Cardioscience, Sheikh Khalifa Medical City, Abu Dhabi, UAEAbstract: Diabetes mellitus is associated with an increased risk of cardiovascular disease, even in the presence of intensive glycemic control. Substantial clinical and experimental evidence suggest that both diabetes and insulin resistance cause a combination of endothelial dysfunctions, which may diminish the anti-atherogenic role of the vascular endothelium. Both insulin resistance and endothelial dysfunction appear to precede the development of overt hyperglycemia in patients with type 2 diabetes. Therefore, in patients with diabetes or insulin resistance, endothelial dysfunction may be a critical early target for preventing atherosclerosis and cardiovascular disease. Microalbuminuria is now considered to be an atherosclerotic risk factor and predicts future cardiovascular disease risk in diabetic patients, in elderly patients, as well as in the general population. It has been implicated as an independent risk factor for cardiovascular disease and premature cardiovascular mortality for patients with type 1 and type 2 diabetes mellitus, as well as for patients with essential hypertension. A complete biochemical understanding of the mechanisms by which hyperglycemia causes vascular functional and structural changes associated with the diabetic milieu still eludes us. In recent years, the numerous biochemical and metabolic pathways postulated to have a causal role in the pathogenesis of diabetic vascular disease have been distilled into several unifying hypotheses. The role of chronic hyperglycemia in the development of diabetic microvascular complications and in neuropathy has been clearly established. However, the biochemical or cellular links between elevated blood glucose levels, and the vascular lesions remain

  12. Membrane configuration optimization for a murine in vitro blood-brain barrier model.

    Science.gov (United States)

    Wuest, Diane M; Wing, Allison M; Lee, Kelvin H

    2013-01-30

    A powerful experimental tool used to study the dynamic functions of the blood-brain barrier (BBB) is an in vitro cellular based system utilizing cell culture inserts in multi-well plates. Currently, usage of divergent model configurations without explanation of selected variable set points renders data comparisons difficult and limits widespread understanding. This work presents for the first time in literature a comprehensive screening study to optimize membrane configuration, with aims to unveil influential membrane effects on the ability of cerebral endothelial cells to form a tight monolayer. First, primary murine brain endothelial cells and astrocytes were co-cultured in contact and non-contact orientations on membranes of pore diameter sizes ranging from 0.4 μm to 8.0 μm, and the non-contact orientation and smallest pore diameter size were shown to support a significantly tighter monolayer formation. Then, membranes made from polyethylene terephthalate (PET) and polycarbonate (PC) purchased from three different commercial sources were compared, and PET membranes purchased from two manufacturers facilitated a significantly tighter monolayer formation. Models were characterized by transendothelial electrical resistance (TEER), sodium fluorescein permeability, and immunocytochemical labeling of tight junction proteins. Finally, a murine brain endothelial cell line, bEnd.3, was grown on the different membranes, and similar results were obtained with respect to optimal membrane configuration selection. The results and methodology presented here on high throughput 24-well plate inserts can be translated to other BBB systems to advance model understanding. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Scaffolding for Three-Dimensional Embryonic Vasculogenesis

    Science.gov (United States)

    Kraehenbuehl, Thomas P.; Aday, Sezin; Ferreira, Lino S.

    Biomaterial scaffolds have great potential to support efficient vascular differentiation of embryonic stem cells. Vascular cell fate-specific biochemical and biophysical cues have been identified and incorporated into three-dimensional (3D) biomaterials to efficiently direct embryonic vasculogenesis. The resulting vascular-like tissue can be used for regenerative medicine applications, further elucidation of biophysical and biochemical cues governing vasculogenesis, and drug discovery. In this chapter, we give an overview on the following: (1) developmental cues for directed differentiation of human embryonic stem cells (hESCs) into vascular cells, (2) 3D vascular differentiation in embryoid bodies (EBs), (3) preparation of 3D scaffolds for the vascular differentiation of hESCs, and (4) the most significant studies combining scaffolding and hESCs for development of vascular-like tissue.

  14. Derivation of Traceable and Transplantable Photoreceptors from Mouse Embryonic Stem Cells

    Directory of Open Access Journals (Sweden)

    Sarah Decembrini

    2014-06-01

    Full Text Available Retinal degenerative diseases resulting in the loss of photoreceptors are one of the major causes of blindness. Photoreceptor replacement therapy is a promising treatment because the transplantation of retina-derived photoreceptors can be applied now to different murine retinopathies to restore visual function. To have an unlimited source of photoreceptors, we derived a transgenic embryonic stem cell (ESC line in which the Crx-GFP transgene is expressed in photoreceptors and assessed the capacity of a 3D culture protocol to produce integration-competent photoreceptors. This culture system allows the production of a large number of photoreceptors recapitulating the in vivo development. After transplantation, integrated cells showed the typical morphology of mature rods bearing external segments and ribbon synapses. We conclude that a 3D protocol coupled with ESCs provides a safe and renewable source of photoreceptors displaying a development and transplantation competence comparable to photoreceptors from age-matched retinas.

  15. Quantitative glycomics monitoring of induced pluripotent- and embryonic stem cells during neuronal differentiation

    Directory of Open Access Journals (Sweden)

    Michiyo Terashima

    2014-11-01

    Full Text Available Alterations in the structure of cell surface glycoforms occurring during the stages of stem cell differentiation remain unclear. We describe a rapid glycoblotting-based cellular glycomics method for quantitatively evaluating changes in glycoform expression and structure during neuronal differentiation of murine induced pluripotent stem cells (iPSCs and embryonic stem cells (ESCs. Our results show that changes in the expression of cellular N-glycans are comparable during the differentiation of iPSCs and ESCs. The expression of bisect-type N-glycans was significantly up-regulated in neurons that differentiated from both iPSCs and ESCs. From a glycobiological standpoint, iPSCs are an alternative neural cell source in addition to ESCs.

  16. Generation of embryoid bodies from mouse embryonic stem cells cultured on STO feeder cells.

    Science.gov (United States)

    Zhou, Qing-Jun; Shao, Jian-Zhong; Xiang, Li-Xin; Hu, Ruo-Zhen; Lu, Yong-Liang; Yao, Hang; Dai, Li-Cheng

    2005-09-01

    Embryoid bodies, which are similar to post-implantation egg-cylinder stage embryos, provide a model for the study of embryo development and stem cell differentiation. We describe here a novel method for generating embryoid bodies from murine embryonic stem (ES) cells cultured on the STO feeder layer. The ES cells grew into compact aggregates in the first 3 days of coculture, then became simple embryoid bodies (EBs) possessing primitive endoderm on the outer layer. They finally turned into cystic embryoid bodies after being transferred to Petri dishes for 1-3 days. Evaluation of the EBs in terms of morphology and differentiating potential indicates that they were typical in structure and could generate cells derived from the three germ layers. The results show that embryoid bodies can form not only in suspension culture but also directly from ES cells cultured on the STO feeder layer.

  17. Combinatory action of VEGFR2 and MAP kinase pathways maintains endothelial-cell integrity

    Institute of Scientific and Technical Information of China (English)

    Hanbing Zhong; Danyang Wang; Nan Wang; Yesenia Rios; Haigen Huang; Song Li; Xinrong Wu; Shuo Lin

    2011-01-01

    Blood vessels normally maintain stereotyped lumen diameters and their stable structures are crucial for vascular function. However, very little is known about the molecular mechanisms controlling the maintenance of vessel diameters and the integrity of endothelial cells. We investigated this issue in zebrafish embryos by a chemical genetics approach. Small molecule libraries were screened using live Tg(kdrl:GRCFP)zn1 transgenic embryos in which endothelial cells are specifically labeled with GFP. By analyzing the effects of compounds on the morphology and function of embryonic blood vessels after lumen formation, PP1, a putative Src kinase inhibitor, was identified as capable of specifically reducing vascular lumen size by interrupting endothelial-cell integrity. The inhibitory effect is not due to Src or general VEGF signaling inhibition because another Src inhibitor and Src morpholino as well as several VEGFR inhibitors failed to produce a similar phenotype. After profiling a panel of 22 representative mammalian kinases and surveying published data, we selected a few possible new candidates. Combinational analysis of these candidate kinase inhibitors established that PP1 induced endothelial collapse by inhibiting both the VEGFR2 and MAP kinase pathways. More importantly, combinatory use of two clinically approved drugs Dasatinib and Sunitinib produced the same phenotype. This is the first study to elucidate the pathways controlling maintenance of endothelial integrity using a chemical genetics approach, indicating that endothelial integrity is controlled by the combined action of the VEGFR2 and MAP kinase pathways. Our results also suggest the possible side effect of the combination of two anticancer drugs on the circulatory system.

  18. Embryonic Stem Cells: Isolation, Characterization and Culture

    Science.gov (United States)

    Amit, Michal; Itskovitz-Eldor, Joseph

    Embryonic stem cells are pluripotent cells isolated from the mammalian blastocyst. Traditionally, these cells have been derived and cultured with mouse embryonic fibroblast (MEF) supportive layers, which allow their continuous growth in an undifferentiated state. However, for any future industrial or clinical application hESCs should be cultured in reproducible, defined, and xeno-free culture system, where exposure to animal pathogens is prevented. From their derivation in 1998 the methods for culturing hESCs were significantly improved. This chapter wills discuss hESC characterization and the basic methods for their derivation and maintenance.

  19. Endothelial dysfunction: a comprehensive appraisal

    Directory of Open Access Journals (Sweden)

    Vilariño Jorge O

    2006-02-01

    Full Text Available Abstract The endothelium is a thin monocelular layer that covers all the inner surface of the blood vessels, separating the circulating blood from the tissues. It is not an inactive organ, quite the opposite. It works as a receptor-efector organ and responds to each physical or chemical stimulus with the release of the correct substance with which it may maintain vasomotor balance and vascular-tissue homeostasis. It has the property of producing, independently, both agonistic and antagonistic substances that help to keep homeostasis and its function is not only autocrine, but also paracrine and endocrine. In this way it modulates the vascular smooth muscle cells producing relaxation or contraction, and therefore vasodilatation or vasoconstriction. The endothelium regulating homeostasis by controlling the production of prothrombotic and antithrombotic components, and fibrynolitics and antifibrynolitics. Also intervenes in cell proliferation and migration, in leukocyte adhesion and activation and in immunological and inflammatory processes. Cardiovascular risk factors cause oxidative stress that alters the endothelial cells capacity and leads to the so called endothelial "dysfunction" reducing its capacity to maintain homeostasis and leads to the development of pathological inflammatory processes and vascular disease. There are different techniques to evaluate the endothelium functional capacity, that depend on the amount of NO produced and the vasodilatation effect. The percentage of vasodilatation with respect to the basal value represents the endothelial functional capacity. Taking into account that shear stress is one of the most important stimulants for the synthesis and release of NO, the non-invasive technique most often used is the transient flow-modulate "endothelium-dependent" post-ischemic vasodilatation, performed on conductance arteries such as the brachial, radial or femoral arteries. This vasodilatation is compared with the

  20. Embryonic adaptations and nutrition in the viviparous teleost Clinus ...

    African Journals Online (AJOL)

    extensive embryonic adaptations for the uptake of nutrients secreted by the ... and in most cases a hypertrophied embryonic gut plays a role in nutrient absorption ..... Cellular surface projections in C. dorsalis are virtually confined to the ...

  1. Embryonic stem cells: testing the germ-cell theory.

    Science.gov (United States)

    Hochedlinger, Konrad

    2011-10-25

    The exact cellular origin of embryonic stem cells remains elusive. Now a new study provides compelling evidence that embryonic stem cells, established under conventional culture conditions, originate from a transient germ-cell state.

  2. The production and directed differentiation of human embryonic stem cells.

    Science.gov (United States)

    Trounson, Alan

    2006-04-01

    Human embryonic stem cells (hESCs) are being rapidly produced from chromosomally euploid, aneuploid, and mutant human embryos that are available from in vitro fertilization clinics treating patients for infertility or preimplantation genetic diagnosis. These hESC lines are an important resource for functional genomics, drug screening, and, perhaps eventually, cell and gene therapy. The methods for deriving hESCs are well established and repeatable and are relatively successful with a ratio of 1:10 to 1:2 new hESC lines produced from 4- to 8-d-old morula and blastocysts and from isolated inner cell mass cell clusters of human blastocysts. The hESCs can be formed and maintained on human somatic cells in humanized serum-free culture conditions and for several passages in cell-free culture systems. The hESCs can be transfected with DNA constructs. Their gene expression profiles are being described and immunological characteristics determined. They may be grown indefinitely in vitro while maintaining their original karyotype and epigenetic status, but this needs to be confirmed from time to time in long-term cultures. hESCs spontaneously differentiate in the absence of the appropriate cell feeder layer, when overgrown in culture and when isolated from the ESC colony. All three major embryonic lineages are produced in differentiating flat attachment cultures and unattached embryoid bodies. Cell progenitors of interest can be identified by markers, expression of reporter genes, and characteristic morphology, and the cells thereafter enriched for progenitor types and further culture to more mature cell types. Directed differentiation systems are well developed for ectodermal pathways that result in neural and glial cells and the mesendodermal pathway for cardiac muscle cells and many other cell types including hematopoietic progenitors and endothelial cells. Directed differentiation into endoderm has been more difficult to achieve, perhaps because of the lack of markers of

  3. Post-transcriptional control of Amblyomin-X on secretion of vascular endothelial growth factor and expression of adhesion molecules in endothelial cells.

    Science.gov (United States)

    Drewes, C C; Dias, R Y; Branco, V G; Cavalcante, M F; Souza, J G; Abdalla, D S P; Chudzinski-Tavassi, A M; Farsky, S H P

    2015-07-01

    Angiogenesis is a pivotal process of homeostasis and tissue repair, but it also favours neovascularisation syndromes and cancer nutrition. The chemical mediation of angiogenesis is complex, involving a balance between serine proteases and their inhibitors. We addressed the mechanisms of action of a Kunitz serine protease inhibitor (KPI) on spontaneous angiogenesis, using Amblyomin-X, a KPI designed from the cDNA library of the Amblyomma cajennense tick. Amblyomin-X treatment (10-1000 ng/10 μL; each 48 h; 3 times) reduced the number of vessels in the subcutaneous dorsal tissue of male Swiss mice, as measured by intravital microscopy, haematoxylin-eosin staining, and PECAM-1 immunofluorescence labeling. Incubation of Amblyomin-X with t-End endothelial cells, a murine endothelial microvascular lineage, did not alter cell proliferation, cell-cycle phases, necrosis and apoptosis, and the production of nitric oxide and prostaglandin E2. Nevertheless, Amblyomin-X treatment reduced t-End migration and adhesion to Matrigel(®), and inhibited the VEGF-A secretion and VCAM-1 and β3 integrin expressions by posttranscriptional pathways. Together, data herein outline novel posttranscriptional mechanisms of KPIs on endothelial cells during angiogenesis and point out the possible application of Amblyomin-X as a local inhibitor to undesired neovascularisation process.

  4. Highly efficient differentiation of neural precursors from human embryonic stem cells and benefits of transplantation after ischemic stroke in mice.

    Science.gov (United States)

    Drury-Stewart, Danielle; Song, Mingke; Mohamad, Osama; Guo, Ying; Gu, Xiaohuan; Chen, Dongdong; Wei, Ling

    2013-08-08

    Ischemic stroke is a leading cause of death and disability, but treatment options are severely limited. Cell therapy offers an attractive strategy for regenerating lost tissues and enhancing the endogenous healing process. In this study, we investigated the use of human embryonic stem cell-derived neural precursors as a cell therapy in a murine stroke model. Neural precursors were derived from human embryonic stem cells by using a fully adherent SMAD inhibition protocol employing small molecules. The efficiency of neural induction and the ability of these cells to further differentiate into neurons were assessed by using immunocytochemistry. Whole-cell patch-clamp recording was used to demonstrate the electrophysiological activity of human embryonic stem cell-derived neurons. Neural precursors were transplanted into the core and penumbra regions of a focal ischemic stroke in the barrel cortex of mice. Animals received injections of bromodeoxyuridine to track regeneration. Neural differentiation of the transplanted cells and regenerative markers were measured by using immunohistochemistry. The adhesive removal test was used to determine functional improvement after stroke and intervention. After 11 days of neural induction by using the small-molecule protocol, over 95% of human embryonic stem-derived cells expressed at least one neural marker. Further in vitro differentiation yielded cells that stained for mature neuronal markers and exhibited high-amplitude, repetitive action potentials in response to depolarization. Neuronal differentiation also occurred after transplantation into the ischemic cortex. A greater level of bromodeoxyuridine co-localization with neurons was observed in the penumbra region of animals receiving cell transplantation. Transplantation also improved sensory recovery in transplant animals over that in control animals. Human embryonic stem cell-derived neural precursors derived by using a highly efficient small-molecule SMAD inhibition

  5. Interactions of primary neuroepithelial progenitor and brain endothelial cells: distinct effect on neural progenitor maintenance and differentiation by soluble factors and direct contact

    Institute of Scientific and Technical Information of China (English)

    Miguel A Gama Sosa; Rita De Gasperi; Anne B Rocher; Gissel M Perez; Keila Simons; Daniel E Cruz; Patrick R Hof; Gregory A Elder

    2007-01-01

    Neurovascular interactions are crucial for the normal development of the central nervous system. To study such interactions in primary cultures, we developed a procedure to simultaneously isolate neural progenitor and endothelial cell fractions from embryonic mouse brains. Depending on the culture conditions endothelial cells were found to favor maintenance of the neuroprogenitor phenotype through the production of soluble factors, or to promote neuronal differentiation of neural progenitors through direct contact. These apparently opposing effects could reflect differential cellular interactions needed for the proper development of the brain.

  6. Circulating endothelial progenitor cells do not contribute to regeneration of endothelium after murine arterial injury

    DEFF Research Database (Denmark)

    Hagensen, Mette; Raarup, Merete Krog; Mortensen, Martin Bødtker

    2012-01-01

    (GFP) in ECs. We found that the endothelium regenerated with GFP(+) ECs as a function of time, evolving from the anastomosis sites towards the centre of the transplant. A migration front of ECs at Day 7 was verified by scanning electron microscopy and by bright-field microscopy using recipient TIE2-lacZ...

  7. Apoptosis in irradiated murine tumors.

    Science.gov (United States)

    Stephens, L C; Ang, K K; Schultheiss, T E; Milas, L; Meyn, R E

    1991-09-01

    Early radiation responses of transplantable murine ovarian (OCaI) and hepatocellular (HCaI) carcinomas were examined at 6, 24, 48, 96, and 144 h after single photon doses of 25, 35, or 45 Gy. Previous studies using tumor growth delay and tumor radiocurability assays had shown OCaI tumors to be relatively radiosensitive and HCaI tumors to be radioresistant. At 6 h, approximately 20% of nuclei in OCaI tumors showed aberrations characteristic of cell death by apoptosis. This contrasted to an incidence of 3% in HCaI tumors. Mitotic activity was eliminated in OCaI tumors but was only transiently suppressed in HCaI tumors. At 24-96 h, OCaI tumors continued to display apoptosis and progressive necrosis, whereas HCaI tumors responded by exhibiting marked pleomorphism. Factors other than mitotic activity may influence tumor radiosensitivity, and one of these may be susceptibility to induction of apoptosis (programmed cell death), because this was a prominent early radiation response by the radiosensitive OCaI tumors.

  8. Transcriptome Landscapes of Mammalian Embryonic Cells

    NARCIS (Netherlands)

    Brinkhof, B.

    2015-01-01

    This thesis describes research on gene expression profiles from different embryonic stages and cell types to identify genes involved in pluripotency or differentiation in bovine and porcine cells. The results are compared with data from other mammals. RNA expression profiles of morula and blastocyst

  9. Epigenetic control of embryonic stem cell fate

    DEFF Research Database (Denmark)

    Christophersen, Nicolaj Strøyer; Helin, Kristian

    2010-01-01

    Embryonic stem (ES) cells are derived from the inner cell mass of the preimplantation embryo and are pluripotent, as they are able to differentiate into all cell types of the adult organism. Once established, the pluripotent ES cells can be maintained under defined culture conditions, but can also...

  10. Transcriptome Landscapes of Mammalian Embryonic Cells

    NARCIS (Netherlands)

    Brinkhof, B.

    2015-01-01

    This thesis describes research on gene expression profiles from different embryonic stages and cell types to identify genes involved in pluripotency or differentiation in bovine and porcine cells. The results are compared with data from other mammals. RNA expression profiles of morula and blastocyst

  11. Autophagy in human embryonic stem cells.

    Directory of Open Access Journals (Sweden)

    Thien Tra

    Full Text Available Autophagy (macroautophagy is a degradative process that involves the sequestration of cytosolic material including organelles into double membrane vesicles termed autophagosomes for delivery to the lysosome. Autophagy is essential for preimplantation development of mouse embryos and cavitation of embryoid bodies. The precise roles of autophagy during early human embryonic development, remain however largely uncharacterized. Since human embryonic stem cells constitute a unique model system to study early human embryogenesis we investigated the occurrence of autophagy in human embryonic stem cells. We have, using lentiviral transduction, established multiple human embryonic stem cell lines that stably express GFP-LC3, a fluorescent marker for the autophagosome. Each cell line displays both a normal karyotype and pluripotency as indicated by the presence of cell types representative of the three germlayers in derived teratomas. GFP expression and labelling of autophagosomes is retained after differentiation. Baseline levels of autophagy detected in cultured undifferentiated hESC were increased or decreased in the presence of rapamycin and wortmannin, respectively. Interestingly, autophagy was upregulated in hESCs induced to undergo differentiation by treatment with type I TGF-beta receptor inhibitor SB431542 or removal of MEF secreted maintenance factors. In conclusion we have established hESCs capable of reporting macroautophagy and identify a novel link between autophagy and early differentiation events in hESC.

  12. Skeletal tissue engineering using embryonic stem cells

    NARCIS (Netherlands)

    Jukes, Jojanneke Maria

    2009-01-01

    Tissue engineering aims at repairing or replacing damaged or diseased tissue. In this thesis, we investigated the potential of embryonic stem cells (ESCs) for cartilage tissue engineering. After differentiation of mouse and human ESCs into the chondrogenic and osteogenic lineage had been established

  13. Physiopathology of human embryonic implantation: clinical incidences.

    Directory of Open Access Journals (Sweden)

    Pauline Demailly

    2010-01-01

    Full Text Available Embryo implantation consists of a series of events promoting the invasion of the endometrium and then the uterine arterial system by the extra-embryonic trophoblast. In order for this semi-heterologous implantation to succeed, the endometrium has to first undergo a number of structural and biochemical changes (decidualization. The decidua's various constituents subsequently play a role in the embryonic implantation. The third step is the transformation of the uterine vascular system and the growth of the placenta, which will provide the foetoplacental unit with nutrients. Several physiopathological aspects will be discussed: 1 the implantation window, regulated by maternal and embryonic hormonal secretions and thus influenced by any defects in the latter: dysharmonic luteal phase, 21-hydroxylase block, abnormal integrin expression, 2 the successive trophoblast invasions of uterine vessels which, when defective, lead to early embryo loss or late-onset vascular pathologies, as preeclampsia, 3 the pregnancy's immunological equilibrium, with a spontaneously tolerated semi-allogeneic implant, 4 the impact of pro-coagulant factors (thrombophilia on the pregnancy's progression, 5 the environment of the uterus, ranging from hydrosalpinx to uterine contractions. In summary, the least anatomical or physiological perturbation can interfere with human embryonic implantation - a very particular phenomenon and a true biological paradox.

  14. Oligonucleotide and Parylene Surface Coating of Polystyrene and ePTFE for Improved Endothelial Cell Attachment and Hemocompatibility

    Directory of Open Access Journals (Sweden)

    Martina Schleicher

    2012-01-01

    Full Text Available In vivo self-endothelialization by endothelial cell adhesion on cardiovascular implants is highly desirable. DNA-oligonucleotides are an intriguing coating material with nonimmunogenic characteristics and the feasibility of easy and rapid chemical fabrication. The objective of this study was the creation of cell adhesive DNA-oligonucleotide coatings on vascular implant surfaces. DNA-oligonucleotides immobilized by adsorption on parylene (poly(monoaminomethyl-para-xylene coated polystyrene and ePTFE were resistant to high shear stress (9.5 N/m2 and human blood serum for up to 96 h. Adhesion of murine endothelial progenitor cells, HUVECs and endothelial cells from human adult saphenous veins as well as viability over a period of 14 days of HUVECs on oligonucleotide coated samples under dynamic culture conditions was significantly enhanced (P<0.05. Oligonucleotide-coated surfaces revealed low thrombogenicity and excellent hemocompatibility after incubation with human blood. These properties suggest the suitability of immobilization of DNA-oligonucleotides for biofunctionalization of blood vessel substitutes for improved in vivo endothelialization.

  15. Challenges in pediatric endothelial keratoplasty

    Directory of Open Access Journals (Sweden)

    Vikas Mittal

    2014-01-01

    Full Text Available We performed endothelial keratoplasty (EK in three eyes of two siblings (2.5 years, male and 3.5 years, female with congenital hereditary endothelial dystrophy (CHED and report the intraoperative and postoperative difficulties. Repeated iris prolapse, apprehension of crystalline lens touch due to positive vitreous pressure, and need for frequent air injections to attach the graft were intraoperative challenges in all three eyes. These were addressed by use of Sheet′s glide instead of Busin′s glide during graft insertion and suturing of main and side ports before air injection. One eye had graft dislocation on second postoperative day due to eye rubbing by the child. Graft was repositioned with air and a venting incision was created. Postoperative examination required repeated general anesthesia. Corneal edema resolved completely in all three eyes. Present case series highlights the possible intraoperative and postoperative challenges and their solutions in pediatric EK for CHED.

  16. Detection of tissue-specific effects by methotrexate on differentiating mouse embryonic stem cells.

    Science.gov (United States)

    Pellizzer, Cristian; Bello, Ezia; Adler, Sarah; Hartung, Thomas; Bremer, Susanne

    2004-10-01

    Pluripotent embryonic stem (ES) cells offer a unique possibility to monitor the differentiation of several cell types in vitro. This study attempts to identify marker genes during in vitro cell differentiation of murine ES cells and allow a prediction of chemical effects on cell differentiation of specific target tissues. The study focused on the expression pattern of key genes involved in cardiomyocyte and osteoblast differentiation: Oct-4, Brachyury, Nkx2.5, alpha myosin heavy chain, Cbfa1, and Osteocalcin. Methotrexate was selected due to its well-characterized teratogenic effects. Several in vivo studies have demonstrated the specific interactions of methotrexate with bone formation whereas the cardiovascular system is not specifically affected after exposure to low concentration. The capability of murine ES cells to differentiate in vitro into cardiomyocytes as well as into osteoblasts have been used to demonstrate the target cell specificity in vitro, at non-cytotoxic concentration. Exposure of differentiating ES cells did not result in any gene profile modification of the selected cardiomyocyte specific genes, whereas the expression of osteoblast specific key genes, Cbfa1 and Osteocalcin, decreased. At the latter stages of skeletal differentiation we observed a 30% decrease in gene expression for Cbfa1 and a 60% decrease for Osteocalcin, with reference to the control. Early marker genes for undifferentiated cells and mesodermal cells were not modified after methotrexate treatment. These results show the possibility to integrate specific in vitro tests for teratogenicity in a test strategy for developmental toxicity. 2004 Wiley-Liss, Inc.

  17. Differentiation of neurons from neural precursors generated in floating spheres from embryonic stem cells

    Directory of Open Access Journals (Sweden)

    Forrester Jeff

    2009-09-01

    Full Text Available Abstract Background Neural differentiation of embryonic stem (ES cells is usually achieved by induction of ectoderm in embryoid bodies followed by the enrichment of neuronal progenitors using a variety of factors. Obtaining reproducible percentages of neural cells is difficult and the methods are time consuming. Results Neural progenitors were produced from murine ES cells by a combination of nonadherent conditions and serum starvation. Conversion to neural progenitors was accompanied by downregulation of Oct4 and NANOG and increased expression of nestin. ES cells containing a GFP gene under the control of the Sox1 regulatory regions became fluorescent upon differentiation to neural progenitors, and ES cells with a tau-GFP fusion protein became fluorescent upon further differentiation to neurons. Neurons produced from these cells upregulated mature neuronal markers, or differentiated to glial and oligodendrocyte fates. The neurons gave rise to action potentials that could be recorded after application of fixed currents. Conclusion Neural progenitors were produced from murine ES cells by a novel method that induced neuroectoderm cells by a combination of nonadherent conditions and serum starvation, in contrast to the embryoid body method in which neuroectoderm cells must be selected after formation of all three germ layers.

  18. Polyphenols in preventing endothelial dysfunction

    Directory of Open Access Journals (Sweden)

    Sylwia Biegańska-Hensoldt

    2017-03-01

    Full Text Available One of the main causes of mortality in developed countries is atherosclerosis. The pathogenesis of atherosclerosis is associated with endothelial dysfunction. Consumption of food rich in natural antioxidants including polyphenols significantly improves endothelial cells functions.Polyphenols have a beneficial effect on the human body and play an important part in protecting the cardiovascular system. Polyphenols present in food have antioxidant, anti-inflammatory, antihypertensive, antithrombotic and antiproliferative properties. Catechins cause an increase in the activity of endothelial nitric oxide synthase (eNOS and increased production of nitric oxide (NO and decrease in blood pressure. Catechins also reduce platelet adhesion, lower the concentration of C-reactive protein and tumor necrosis factor alpha and interleukin-6. Resveratrol inhibits NADPH oxidase expression, increases the expression of eNOS and NO production as well as decreases the expression of proinflammatory cytokines, and also lowers the concentration of the soluble forms of adhesion molecules – sICAM-1 and sVCAM-1 in blood. Quercetin reduces the blood level of low density lipoprotein cholesterol, lowers blood pressure, reduces the concentration of C-reactive protein and F2-isoprostane level. Curcumin has antagonistic activity to homocysteine. Curcumin increases the expression of eNOS and reduces oxidative DNA damage in rat cardiomyocytes. Numerous attempts are taken for improving the bioavailability of polyphenols in order to increase their use in the body.

  19. Promotion of embryonic cortico-cerebral neuronogenesis by miR-124

    Directory of Open Access Journals (Sweden)

    Mallamaci Antonello

    2009-11-01

    Full Text Available Abstract Background Glutamatergic neurons of the murine cerebral cortex are generated within periventricular proliferative layers of the embryonic pallium, directly from apical precursors or indirectly via their basal progenies. Cortical neuronogenesis is the result of different morphogenetic subroutines, including precursor proliferation and death, changes in histogenetic potencies, and post-mitotic neuronal differentiation. Control of these processes is extremely complex, involving numerous polypeptide-encoding genes. Moreover, many so-called 'non-coding genes' are also expressed in the developing cortex. Currently, their implication in corticogenesis is the subject of intensive functional studies. A subset of them encodes microRNAs (miRNAs, a class of small RNAs with complex biogenesis that regulate gene expression at multiple levels and modulate histogenetic progression and are implicated in refinement of positional information. Among the cortical miRNAs, miR-124 has been consistently shown to promote neuronogenesis progression in a variety of experimental contexts. Some aspects of its activity, however, are still controversial, and some have to be clarified. An in depth in vivo characterization of its function in the embryonic mammalian cortex is still missing. Results By integrating locked nucleic acid (LNA-oligo in situ hybridization, electroporation of stage-specific reporters and immunofluorescence, we reconstructed the cortico-cerebral miR-124 expression pattern during direct neuronogenesis from apical precursors and indirect neuronogenesis via basal progenitors. The miR-124 expression profile in the developing embryonic cortex includes an abrupt upregulation in apical precursors undergoing direct neuronogenesis as well as a two-step upregulation in basal progenitors during indirect neuronogenesis. Differential post-transcriptional processing seems to contribute to this pattern. Moreover, we investigated the role of miR-124 in

  20. A novel SALL4/OCT4 transcriptional feedback network for pluripotency of embryonic stem cells.

    Directory of Open Access Journals (Sweden)

    Jianchang Yang

    Full Text Available BACKGROUND: SALL4 is a member of the SALL gene family that encodes a group of putative developmental transcription factors. Murine Sall4 plays a critical role in maintaining embryonic stem cell (ES cell pluripotency and self-renewal. We have shown that Sall4 activates Oct4 and is a master regulator in murine ES cells. Other SALL gene members, especially Sall1 and Sall3 are expressed in both murine and human ES cells, and deletions of these two genes in mice lead to perinatal death due to developmental defects. To date, little is known about the molecular mechanisms controlling the regulation of expressions of SALL4 or other SALL gene family members. METHODOLOGY/PRINCIPAL FINDINGS: This report describes a novel SALL4/OCT4 regulator feedback loop in ES cells in balancing the proper expression dosage of SALL4 and OCT4 for the maintenance of ESC stem cell properties. While we have observed that a positive feedback relationship is present between SALL4 and OCT4, the strong self-repression of SALL4 seems to be the "break" for this loop. In addition, we have shown that SALL4 can repress the promoters of other SALL family members, such as SALL1 and SALL3, which competes with the activation of these two genes by OCT4. CONCLUSIONS/SIGNIFICANCE: Our findings, when taken together, indicate that SALL4 is a master regulator that controls its own expression and the expression of OCT4. SALL4 and OCT4 work antagonistically to balance the expressions of other SALL gene family members. This novel SALL4/OCT4 transcription regulation feedback loop should provide more insight into the mechanism of governing the "stemness" of ES cells.

  1. Loss of p53 Ser18 and Atm results in embryonic lethality without cooperation in tumorigenesis.

    Directory of Open Access Journals (Sweden)

    Heather L Armata

    Full Text Available Phosphorylation at murine Serine 18 (human Serine 15 is a critical regulatory process for the tumor suppressor function of p53. p53Ser18 residue is a substrate for ataxia-telangiectasia mutated (ATM and ATM-related (ATR protein kinases. Studies of mice with a germ-line mutation that replaces Ser18 with Ala (p53(S18A mice have demonstrated that loss of phosphorylation of p53Ser18 leads to the development of tumors, including lymphomas, fibrosarcomas, leukemia and leiomyosarcomas. The predominant lymphoma is B-cell lymphoma, which is in contrast to the lymphomas observed in Atm(-/- animals. This observation and the fact that multiple kinases phosphorylate p53Ser18 suggest Atm-independent tumor suppressive functions of p53Ser18. Therefore, in order to examine p53Ser18 function in relationship to ATM, we analyzed the lifespan and tumorigenesis of mice with combined mutations in p53Ser18 and Atm. Surprisingly, we observed no cooperation in survival and tumorigenesis in compound p53(S18A and Atm(-/- animals. However, we observed embryonic lethality in the compound mutant animals. In addition, the homozygous p53Ser18 mutant allele impacted the weight of Atm(-/- animals. These studies examine the genetic interaction of p53Ser18 and Atm in vivo. Furthermore, these studies demonstrate a role of p53Ser18 in regulating embryonic survival and motor coordination.

  2. Early embryonic failure: Expression and imprinted status of candidate genes on human chromosome 21

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, L.S.; Bennett, P.R.; Moore, G.E. [Queen Charlotte`s and Chelsea Hospital, London (United Kingdom)

    1994-09-01

    Two cases of maternal uniparental (hetero)disomy for human chromosome 21 (mUPD21) have been identified in a systematic search for UPD in 23 cases of early embryonic failure (EEF). Bi-parental origin of the other chromosome pairs was confirmed using specific VNTR probes or dinucleotide repeat analysis. Both maternally and paternally derived isochromosomes 21q have previously been identified in two individuals with normal phenotypes. Full UPD21 has a different mechanism of origin than uniparental isochromosome 21q and its effect on imprinted genes and phenotypic outcome will therefore not necessarily be the same. EEF associated with mUPD21 suggests that developmentally important genes on HSA 21 may be imprinted such that they are only expressed from either the maternally or paternally derived alleles. We have searched for monoallelic expression of candidate genes on HSA 21 in human pregnancy (CBS, IFNAR, COL6A1) using intragenic DNA polymorphisms. These genes were chosen either because their murine homologues lie in imprinted regions or because they are potentially important in embryogenesis. Once imprinted candidate genes have been identified, their methylation status and expression in normal, early embryonic failure and uniparental disomy 21 pregnancies will be studied. At the same time, a larger number of cases of EEF are being examined to further investigate the incidence of UPD21 in this group.

  3. Differentiation of mouse embryonic stem cells into endoderm without embryoid body formation.

    Directory of Open Access Journals (Sweden)

    Peter T W Kim

    Full Text Available Pluripotent embryonic stem cells hold a great promise as an unlimited source of tissue for treatment of chronic diseases such as Type 1 diabetes. Herein, we describe a protocol using all-trans-retinoic acid, basic fibroblast growth factor and dibutyryl cAMP (DBcAMP in the absence of embryoid body formation, for differentiation of murine embryonic stem cells into definitive endoderm that may serve as pancreatic precursors. The produced cells were analyzed by quantitative PCR, immunohistochemistry and static insulin release assay for markers of trilaminar embryo, and pancreas. Differentiated cells displayed increased Sox17 and Foxa2 expression consistent with definitive endoderm production. There was minimal production of Sox7, an extraembryonic endoderm marker, and Oct4, a marker of pluripotency. There was minimal mesoderm or neuroectoderm formation based on expression levels of the markers brachyury and Sox1, respectively. Various assays revealed that the cell clusters generated by this protocol express markers of the pancreatic lineage including insulin I, insulin II, C-peptide, PDX-1, carboxypeptidase E, pan-cytokeratin, amylase, glucagon, PAX6, Ngn3 and Nkx6.1. This protocol using all-trans-retinoic acid, DBcAMP, in the absence of embryoid bodies, generated cells that have features of definitive endoderm that may serve as pancreatic endocrine precursors.

  4. Embryonic stem-like cells derived from in vitro produced bovine blastocysts

    Directory of Open Access Journals (Sweden)

    Erika Regina Leal de Freitas

    2011-06-01

    Full Text Available The aim of this work was to study the derivation of bovine embryonic stem-like (ES-like cells from the inner cell mass (ICM of in vitro produced blastocysts. The ICMs were mechanically isolated and six out of seventeen (35% ICMs could attach to a monolayer of murine embryonic fibroblasts (MEF. Ten days after, primary outgrowths were mechanically dissected into several small clumps and transferred to a new MEF layer. Cells were further propagated and passaged by physical dissociation over a 60 days period. The pluripotency of the bovine ES-like cells was confirmed by RT-PCR of Oct-4 and STAT-3 gene markers. The colonies were weakly stained for alkaline phosphatase and the mesoderm and endoderm differentiation gene markers such as GATA-4 and Flk-1, respectively, were not expressed. Embryoid bodies were spontaneously formed at the seventh passage. Results showed that bovine ES-like cells could be obtained and passaged by mechanical procedures from the fresh in vitro produced blastocysts.

  5. Fate of D3 mouse embryonic stem cells exposed to X-rays or carbon ions.

    Science.gov (United States)

    Luft, S; Pignalosa, D; Nasonova, E; Arrizabalaga, O; Helm, A; Durante, M; Ritter, S

    2014-01-15

    The risk of radiation exposure during embryonic development is still a major problem in radiotoxicology. In this study we investigated the response of the murine embryonic stem cell (mESC) line D3 to two radiation qualities: sparsely ionizing X-rays and densely ionizing carbon ions. We analyzed clonogenic cell survival, proliferation, induction of chromosome aberrations as well as the capability of cells to differentiate to beating cardiomyocytes up to 3 days after exposure. Our results show that, for all endpoints investigated, carbon ions are more effective than X-rays at the same radiation dose. Additionally, in long term studies (≥8 days post-irradiation) chromosomal damage and the pluripotency state were investigated. These studies reveal that pluripotency markers are present in the progeny of cells surviving the exposure to both radiation types. However, only in the progeny of X-ray exposed cells the aberration frequency was comparable to that of the control population, while the progeny of carbon ion irradiated cells harbored significantly more aberrations than the control, generally translocations. We conclude that cells surviving the radiation exposure maintain pluripotency but may carry stable chromosomal rearrangements after densely ionizing radiation.

  6. Simvastatin impairs murine melanoma growth

    Directory of Open Access Journals (Sweden)

    Barros Francisco E

    2010-12-01

    Full Text Available Abstract Background Statins induces cell cycle arrest, apoptosis, reduction of angiogenic factors, inhibition of the endothelial growth factor, impairing tissue adhesion and attenuation of the resistance mechanisms. The aim of this study was evaluate the anti-tumoral activity of simvastatin in a B16F10 melanoma-mouse model. Methods Melanoma cells were treated with different concentrations of simvastatin and assessed by viability methods. Melanoma cells (5 × 104 were implanted in two month old C57Bl6/J mice. Around 7 days after cells injection, the oral treatments were started with simvastatin (5 mg/kg/day, p.o.. Tumor size, hematological and biochemical analyses were evaluated. Results Simvastatin at a concentration of 0.8 μM, 1.2 μM and 1.6 μM had toxic effect. Concentration of 1.6 μM induced a massive death in the first 24 h of incubation. Simvastatin at 0.8 μM induces early cell cycle arrest in G0/G1, followed by increase of hypodiploidy. Tumor size were evaluated and the difference of treated group and control, after ten days, demonstrates that simvastatin inhibited the tumor expansion in 68%. Conclusion Simvastatin at 1.6 μM, presented cytototoxicity after 72 h of treatment, with an intense death. In vivo, simvastatin being potentially useful as an antiproliferative drug, with an impairment of growth after ten days.

  7. Signaling by Retinoic Acid in Embryonic and Adult Hematopoiesis

    Directory of Open Access Journals (Sweden)

    Elena Cano

    2014-03-01

    Full Text Available Embryonic and adult hematopoiesis are both finely regulated by a number of signaling mechanisms. In the mammalian embryo, short-term and long-term hematopoietic stem cells (HSC arise from a subset of endothelial cells which constitute the hemogenic endothelium. These HSC expand and give rise to all the lineages of blood cells in the fetal liver, first, and in the bone marrow from the end of the gestation and throughout the adult life. The retinoic acid (RA signaling system, acting through the family of nuclear retinoic acid receptors (RARs and RXRs, is involved in multiple steps of the hematopoietic development, and also in the regulation of the differentiation of some myeloid lineages in adults. In humans, the importance of this RA-mediated control is dramatically illustrated by the pathogeny of acute promyelocytic leukemia, a disease produced by a chromosomal rearrangement fusing the RARa gene with other genes. The aberrant fusion protein is able to bind to RARα target gene promoters to actively suppress gene transcription. Lack of function of RARα leads to a failure in the differentiation of promyelocytic progenitors. In this review we have collected the available information about all the phases of the hematopoietic process in which RA signaling is involved, being essential for steps such as the emergence of HSC from the hemogenic endothelium, or modulating processes such as the adult granulopoiesis. A better knowledge of the RA-mediated signaling mechanisms can contribute to the knowledge of the origin of many pathologies of the hematopoietic system and can provide new clinical avenues for their treatment.

  8. m-Calpain is required for preimplantation embryonic development in mice

    Directory of Open Access Journals (Sweden)

    Williams Karen

    2006-01-01

    Full Text Available Abstract Background μ-calpain and m-calpain are ubiquitously expressed proteases implicated in cellular migration, cell cycle progression, degenerative processes and cell death. These heterodimeric enzymes are composed of distinct catalytic subunits, encoded by Capn1 (μ-calpain or Capn2 (m-calpain, and a common regulatory subunit encoded by Capn4. Disruption of the mouse Capn4 gene abolished both μ-calpain and m-calpain activity, and resulted in embryonic lethality, thereby suggesting essential roles for one or both of these enzymes during mammalian embryogenesis. Disruption of the Capn1 gene produced viable, fertile mice implying that either m-calpain could compensate for the loss of μ-calpain, or that the loss of m-calpain was responsible for death of Capn4-/- mice. Results To distinguish between the alternatives described above, we deleted an essential coding region in the mouse Capn2 gene in embryonic stems cells and transmitted this mutant allele through the mouse germline. Breeding of heterozygous animals failed to produce homozygous mutant live offspring or implanted embryos. A nested PCR genotyping protocol was established, and homozygous preimplantation mutant embryos were detected at the morula but not at the blastocyts stage. Conclusion We conclude that homozygous disruption of the Capn2 gene results in pre-implantation embryonic lethality between the morula and blastocyst stage. This establishes that μ-calpain and m-calpain have distinct functions, and that m-calpain is vital for development of the preimplantation murine embryo.

  9. Stage-specific histone modification profiles reveal global transitions in the Xenopus embryonic epigenome.

    Directory of Open Access Journals (Sweden)

    Tobias D Schneider

    Full Text Available Vertebrate embryos are derived from a transitory pool of pluripotent cells. By the process of embryonic induction, these precursor cells are assigned to specific fates and differentiation programs. Histone post-translational modifications are thought to play a key role in the establishment and maintenance of stable gene expression patterns underlying these processes. While on gene level histone modifications are known to change during differentiation, very little is known about the quantitative fluctuations in bulk histone modifications during development. To investigate this issue we analysed histones isolated from four different developmental stages of Xenopus laevis by mass spectrometry. In toto, we quantified 59 modification states on core histones H3 and H4 from blastula to tadpole stages. During this developmental period, we observed in general an increase in the unmodified states, and a shift from histone modifications associated with transcriptional activity to transcriptionally repressive histone marks. We also compared these naturally occurring patterns with the histone modifications of murine ES cells, detecting large differences in the methylation patterns of histone H3 lysines 27 and 36 between pluripotent ES cells and pluripotent cells from Xenopus blastulae. By combining all detected modification transitions we could cluster their patterns according to their embryonic origin, defining specific histone modification profiles (HMPs for each developmental stage. To our knowledge, this data set represents the first compendium of covalent histone modifications and their quantitative flux during normogenesis in a vertebrate model organism. The HMPs indicate a stepwise maturation of the embryonic epigenome, which may be causal to the progressing restriction of cellular potency during development.

  10. A1 demonstrates restricted tissue distribution during embryonic development and functions to protect against cell death.

    Science.gov (United States)

    Carrió, R.; López-Hoyos, M.; Jimeno, J.; Benedict, M. A.; Merino, R.; Benito, A.; Fernández-Luna, J. L.; Núñez, G.; García-Porrero, J. A.; Merino, J.

    1996-01-01

    Members of the bcl-2 gene family are essential regulators of cell survival in a wide range of biological processes. A1, a member of the family, is known to be expressed in certain adult tissues. However, the precise tissue distribution and function of A1 remains poorly understood. We show here that A1 is expressed in multiple tissues during murine embryonic development. In the embryo, A1 was detected first at embryonic day 11.5 in liver, brain, and limbs. At day 13.5 of gestation, A1 expression was observed in the central nervous system, liver, perichondrium, and digital zones of developing limbs in a pattern different from that of bcl-X. In the central nervous system of 15.5-day embryos, A1 was expressed at high levels in the ventricular zone and cortical plate of brain cortex. Significantly, the interdigital zones of limbs and the intermediate region of the developing brain cortex, two sites associated with extensive cell death, were devoid of A1 and bcl-X. The expression of A1 was retained in many adult tissues. To assess the ability of A1 to modulate cell death, stable transfectants expressing different amounts of A1 protein were generated in K562 cells. Expression of A1 was associated with retardation of apoptotic cell death induced by actinomycin D and cycloheximide as well as by okadaic acid. Confocal microscopy showed that the A1 protein was localized to the cytoplasm in a pattern similar to that of Bcl-2. These results demonstrate that the expression of A1 is wider than previously reported in adult tissues. Furthermore, its distribution in multiple tissues of the embryo suggests that A1 plays a role in the regulation of physiological cell death during embryonic development. Images Figure 1 Figure 2 Figure 3 Figure 5 PMID:8952545

  11. [Endothelial dysfunction in hypertension--clinical implications].

    Science.gov (United States)

    Kosmala, Wojciech

    2002-04-01

    Endothelial cells produce both vasodilatating compounds as nitric oxide, prostacycline, endothelial derived hyperpolarising factor and counteracting substances known as endothelial derived contracting factors: endothelin, tromboxan A2, prostaglandin H2, free oxygen radicals. Natural balance between both groups affects blood perfusion of various tissues and constitutes important element in blood pressure control. More and more attention is paid to endothelial dysfunction in patogenesis of hypertension. In a number of studies endothelial dysfunction in hypertensive patients was found out as decreased release of nitric oxide or increased production of endothelin. Principle mechanism of impaired function of endothelium in hypertension seems to be decreased production and increased degradation of nitric oxide mainly due to free oxygen radicals. Favorable effects in improvement of endothelial function were achieved by using ACE inhibitors, AT1 receptor blockers and calcium channel antagonists.

  12. Bone marrow-derived cells are recruited by the melanoma tumor with endothelial cells contributing to tumor vasculature.

    Science.gov (United States)

    Bonfim-Silva, R; Souza, L E B; Melo, F U F; Oliveira, V C; Magalhães, D A R; Oliveira, H F; Covas, D T; Fontes, A M

    2017-01-01

    Tumor expansion is dependent on neovascularization, a process that requires sustained new vessel formation. Although the critical role of angiogenesis by endothelial sprouting in this process, controversy still prevails on whether angiogenesis involving bone marrow-derived endothelial cells, does contribute to this process. This study aims to evaluate the recruitment of bone marrow-derived cells by the melanoma tumor, including endothelial cells, and if they contribute to angiogenesis. A chimeric mouse model of GFP bone marrow was used to induce melanoma tumors derived from murine B16-F10 cell line. These tumors were evaluated for the presence of myeloid cells (CD11b), T lymphocytes (CD3, CD4 and CD8) and endothelial cells (VEGFR2 and CD31) derived from bone marrow. Mice transplanted with GFP+ cells showed significant bone marrow chimerism (90.9 ± 0.87 %) when compared to the GFP transgenic mice (90.66 ± 2.1 %, p = 0.83) demonstrating successful engraftment of donor bone marrow stem/progenitor cells. Analysis of the murine melanoma tumor showed the presence of donor cells in the tumors (3.5 ± 1.7 %) and interestingly, these cells represent endothelial cells (CD31+ cells; 11.5 ± 6.85 %) and myeloid cells (CD11b+ cells; 80 ± 21 %), but also tumor-infiltrating lymphocytes (CD8+ T cells, 13.31 ± 0.2 %; CD4+ T-cells, 2.1 ± 1.2 %). Examination of the tumor endothelium by confocal microscopy suggests the presence of donor CD31+/GFP+ cells in the wall of some blood vessels. This study demonstrates that bone marrow-derived cells are recruited by the murine melanoma tumor, with myeloid cells and CD4 and CD8 T lymphocytes migrating as antitumor immune response, and endothelial cells participating of the tumor blood vessels formation.

  13. Resveratrol: A Multifunctional Compound Improving Endothelial Function

    OpenAIRE

    Li, Huige; Förstermann, Ulrich

    2009-01-01

    The red wine polyphenol resveratrol boosts endothelium-dependent and -independent vasorelaxations. The improvement of endothelial function by resveratrol is largely attributable to nitric oxide (NO) derived from endothelial NO synthase (eNOS). By stimulating eNOS expression, eNOS phosphorylation and eNOS deacetylation, resveratrol enhances endothelial NO production. By upregulating antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase) and suppressing the expression a...

  14. Resveratrol: A Multifunctional Compound Improving Endothelial Function

    OpenAIRE

    Li, Huige; Förstermann, Ulrich

    2009-01-01

    The red wine polyphenol resveratrol boosts endothelium-dependent and -independent vasorelaxations. The improvement of endothelial function by resveratrol is largely attributable to nitric oxide (NO) derived from endothelial NO synthase (eNOS). By stimulating eNOS expression, eNOS phosphorylation and eNOS deacetylation, resveratrol enhances endothelial NO production. By upregulating antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase) and suppressing the expression a...

  15. EXPRESSION OF PLURIPOTENCY MARKERS IN REPROGRAMMING WITH TRANSPOSON SYSTEM MURINE FIBROBLASTS

    Directory of Open Access Journals (Sweden)

    S. V. Malysheva

    2013-10-01

    Full Text Available The search for effective and safe methods to generate induced pluripotent stem cells is especially urgent. In the paper murine embryonic fibro blasts were reprogrammed towards actively proliferating colonies with typical induced pluripotent stem cells morphology by means of Sleeping beauty transposon-based vector system. The obtained clones were checked for the expression of various pluripotency markers: alkaline phosphatase, Oct4 and Sox2 genes, SSEA-1 expression in various clones was evaluated. Also the reactivation of endogenous pluripotency factors Nanog and Rex1 was indicated. The data obtained is analyzed and compared to the established pluripotent stem cell line. It is shown that somatic cells are reprogrammed towards pluripotency by means of Sleeping beauty transposon system. Therefore, the system is a new perspective biotechnological tool to generate pluripotent cells.

  16. Phenotypic correction of murine hemophilia A using an iPS cell-based therapy.

    Science.gov (United States)

    Xu, Dan; Alipio, Zaida; Fink, Louis M; Adcock, Dorothy M; Yang, Jianchang; Ward, David C; Ma, Yupo

    2009-01-20

    Hemophilia A is caused by mutations within the Factor VIII (FVIII) gene that lead to depleted protein production and inefficient blood clotting. Several attempts at gene therapy have failed for various reasons-including immune rejection. The recent generation of induced pluripotent stem (iPS) cells from somatic cells by the ectopic expression of 3 transcription factors, Oct4, Sox2, and Klf4, provides a means of circumventing the immune rejection barrier. To date, iPS cells appear to be indistinguishable from ES cells and thus provide tremendous therapeutic potential. Here we prepared murine iPS cells from tail-tip fibroblasts and differentiated them to both endothelial cells and endothelial progenitor cells by using the embryoid body differentiation method. These iPS cells express major ES cell markers such as Oct4, Nanog, SSEA-1, alkaline phosphatase, and SALL4. Endothelial/endothelial progenitor cells derived from iPS cells expressed cell-specific markers such as CD31, CD34, and Flk1 and secreted FVIII protein. These iPS-derived cells were injected directly into the liver of irradiated hemophilia A mice. At various times after transplantation (7-90 days) hemophilia A mice and their control mice counterparts were challenged by a tail-clip bleeding assay. Nontransplanted hemophilia A mice died within a few hours, whereas transplanted mice survived for more than 3 months. Plasma FVIII levels increased in transplanted hemophilia A mice during this period to 8% to 12% of wild type and corrected the hemophilia A phenotype. Our studies provide additional evidence that iPS cell therapy may be able to treat human monogenetic disorders in the future.

  17. Histology atlas of the developing mouse hepatobiliary system with emphasis on embryonic days 9.5-18.5.

    Science.gov (United States)

    Crawford, Laura Wilding; Foley, Julie F; Elmore, Susan A

    2010-10-01

    Animal model phenotyping, in utero exposure toxicity studies, and investigation into causes of embryonic, fetal, or perinatal deaths have required pathologists to recognize and diagnose developmental disorders in spontaneous and engineered mouse models of disease. In mammals, the liver is the main site of hematopoiesis during fetal development, has endocrine and exocrine functions important for maintaining homeostasis in fetal and adult life; and performs other functions including waste detoxification, production and removal of glucose, glycogen storage, triglyceride and fatty acid processing, and serum protein production. Due to its role in many critical functions, alterations in the size, morphology, or function(s) of the liver often lead to embryonic lethality. Many publications and websites describe individual aspects of hepatobiliary development at defined stages. However, no single resource provides a detailed histological evaluation of H&E-stained sections of the developing murine liver and biliary systems using high-magnification and high-resolution color images. The work herein provides a histology atlas of hepatobiliary development between embryonic days 9.5-18.5. Although the focus of this work is normal hepatobiliary development, common defects in liver development are also described as a reference for pathologists who may be asked to phenotype mice with congenital, inherited, or treatment-related hepatobiliary defects. Authors' note: All digital images can be viewed online at https://niehsimagesepl-inc.com with the username "ToxPathLiver" and the password "embryolivers."

  18. Human Cytomegalovirus and Human Umbilical Vein Endothelial Cells: Restriction of Primary Isolation to Blood Samples and Susceptibilities of Clinical Isolates from Other Sources to Adaptation

    OpenAIRE

    2002-01-01

    In immunocompromised patients with disseminated infection, human cytomegalovirus (HCMV) is widespread in the microvascular endothelium of multiple organs. Human umbilical vein endothelial cells (HUVEC) were used in parallel to human embryonic lung fibroblasts (HELF) to recover HCMV from blood samples of immunocompromised patients. Using the shell vial technique, comparable median numbers of p72-positive HUVEC and HELF cells were found with the 26 HCMV-positive buffy coat samples out of 150 ex...

  19. Patterns of late embryonic and fetal mortality and association with several factors in sheep.

    Science.gov (United States)

    Dixon, A B; Knights, M; Winkler, J L; Marsh, D J; Pate, J L; Wilson, M E; Dailey, R A; Seidel, G; Inskeep, E K

    2007-05-01

    Embryonic and fetal mortality reduce lambing rates and litter sizes, thus contributing to economic losses in the sheep industry. In the current study, the timing of late embryonic and fetal loss in ewes and the factors with which these losses were associated were examined. Ewes lambing and lambs born were compared with pregnancy diagnosis and counts of embryos by ultrasonography near d 25, 45, 65, or 85 of gestation. Approximately 19.9% of the ewes experienced late embryonic loss, fetal loss, or both; and 21.2% of the embryos or fetuses were lost from d 25 to term. Potential offspring were lost throughout gestation; 3.7% of embryos from d 25 to 45, 4.3% of fetuses from d 45 to 65, 3.3% from d 65 to 85, and 11.5% from d 85 to parturition; thus, approximately 3 to 4% of the potential offspring were lost for each 20-d period of pregnancy beyond d 25. A greater proportion of ewes lost one (36.7%) rather than all (20.5% single; 3.8% multiple) embryos or fetuses. The patterns of loss were similar in ewes mated during the anestrous season and the transitional period and did not vary with service period within breeding season or method of synchronization of estrus. Late embryonic or fetal losses were not related to the temperature-humidity index. Maternal serum collected near d 25, 45, 65, or 85 of gestation was assayed for concentrations of progesterone, estradiol-17beta , and vascular endothelial growth factor (VEGF). The proportions of embryos or fetuses lost were associated with breed type (P < 0.05), as were concentrations of progesterone (P < 0.01), estradiol (P < 0.05), and VEGF (P < 0.01). The relationships of loss or retention of pregnancy to hormonal variables at the 4 stages studied were limited. Complete and partial losses increased rapidly as maternal progesterone at d 25 decreased below 2 ng/mL (P < 0.05). Survival of fetuses within a litter from d 25 to 65 was greater for ewes with medium concentrations of VEGF near d 25 and from d 65 to parturition was

  20. A role for smoothened during murine lens and cornea development.

    Directory of Open Access Journals (Sweden)

    Janet J Y Choi

    Full Text Available Various studies suggest that Hedgehog (Hh signalling plays roles in human and zebrafish ocular development. Recent studies (Kerr et al., Invest Ophthalmol Vis Sci. 2012; 53, 3316-30 showed that conditionally activating Hh signals promotes murine lens epithelial cell proliferation and disrupts fibre differentiation. In this study we examined the expression of the Hh pathway and the requirement for the Smoothened gene in murine lens development. Expression of Hh pathway components in developing lens was examined by RT-PCR, immunofluorescence and in situ hybridisation. The requirement of Smo in lens development was determined by conditional loss-of-function mutations, using LeCre and MLR10 Cre transgenic mice. The phenotype of mutant mice was examined by immunofluorescence for various markers of cell cycle, lens and cornea differentiation. Hh pathway components (Ptch1, Smo, Gli2, Gli3 were detected in lens epithelium from E12.5. Gli2 was particularly localised to mitotic nuclei and, at E13.5, Gli3 exhibited a shift from cytosol to nucleus, suggesting distinct roles for these transcription factors. Conditional deletion of Smo, from ∼E12.5 (MLR10 Cre did not affect ocular development, whereas deletion from ∼E9.5 (LeCre resulted in lens and corneal defects from E14.5. Mutant lenses were smaller and showed normal expression of p57Kip2, c-Maf, E-cadherin and Pax6, reduced expression of FoxE3 and Ptch1 and decreased nuclear Hes1. There was normal G1-S phase but decreased G2-M phase transition at E16.5 and epithelial cell death from E14.5-E16.5. Mutant corneas were thicker due to aberrant migration of Nrp2+ cells from the extraocular mesenchyme, resulting in delayed corneal endothelial but normal epithelial differentiation. These results indicate the Hh pathway is required during a discrete period (E9.5-E12.5 in lens development to regulate lens epithelial cell proliferation, survival and FoxE3 expression. Defective corneal development occurs

  1. Progress with nonhuman primate embryonic stem cells.

    Science.gov (United States)

    Wolf, Don P; Kuo, Hung-Chih; Pau, K-Y Francis; Lester, Linda

    2004-12-01

    Embryonic stem cells hold potential in the fields of regenerative medicine, developmental biology, tissue regeneration, disease pathogenicity, and drug discovery. Embryonic stem (ES) cell lines are now available in primates, including man, rhesus, and cynomologous monkeys. Monkey ES cells serve as invaluable clinically relevant models for studies that can't be conducted in humans because of practical or ethical limitations, or in rodents because of differences in physiology and anatomy. Here, we review the current status of nonhuman primate research with ES cells, beginning with a description of their isolation, characterization, and availability. Substantial limitations still plague the use of primate ES cells, such as their required growth on feeder layers, poor cloning efficiency, and restricted availability. The ability to produce homogenous populations of both undifferentiated as well as differentiated phenotypes is an important challenge, and genetic approaches to achieving these objectives are discussed. Finally, safety, efficiency, and feasibility issues relating to the transplantation of ES-derived cells are considered.

  2. Properties and applications of embryonic stem cells

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Mouse embryonic stem (ES) cells are pluripotent cells derived from the early embryo and can be propagated stably in undifferentiated state in vitro. They retain the ability to differentiate into all cell types found in the embryonic and adult body in vivo, and can be induced to differentiate into many cell types under appropriate culture conditions in vitro. Using these properties, people have set up various differentiated systems of many cell types and tissues in vitro. Through analysis of these systems, one can identify novel bioactive factors and reveal mechanisms of cell differentiation and organogenesis. ES cell-derived differentiated cells can also be applied to cell transplantation therapy. In addition, we summarized the features and potential applications of human ES cells.

  3. Cytokine signalling in embryonic stem cells

    DEFF Research Database (Denmark)

    Kristensen, David Møbjerg; Kalisz, Mark; Nielsen, Jens Høiriis

    2006-01-01

    Cytokines play a central role in maintaining self-renewal in mouse embryonic stem (ES) cells through a member of the interleukin-6 type cytokine family termed leukemia inhibitory factor (LIF). LIF activates the JAK-STAT3 pathway through the class I cytokine receptor gp130, which forms a trimeric...... pathways seem to converge on c-myc as a common target to promote self-renewal. Whereas LIF does not seem to stimulate self-renewal in human embryonic stem cells it cannot be excluded that other cytokines are involved. The pleiotropic actions of the increasing number of cytokines and receptors signalling...... via JAKs, STATs and SOCS exhibit considerable redundancy, compensation and plasticity in stem cells in accordance with the view that stem cells are governed by quantitative variations in strength and duration of signalling events known from other cell types rather than qualitatively different stem...

  4. OCT guided microinjections for mouse embryonic research

    Science.gov (United States)

    Larin, Kirill V.; Syed, Saba H.; Coughlin, Andrew J.; Wang, Shang; West, Jennifer L.; Dickinson, Mary E.; Larina, Irina V.

    2013-02-01

    Optical coherence tomography (OCT) is gaining popularity as live imaging tool for embryonic research in animal models. Recently we have demonstrated that OCT can be used for live imaging of cultured early mouse embryos (E7.5-E10) as well as later stage mouse embryos in utero (E12.5 to the end of gestation). Targeted delivery of signaling molecules, drugs, and cells is a powerful approach to study normal and abnormal development, and image guidance is highly important for such manipulations. Here we demonstrate that OCT can be used to guide microinjections of gold nanoshell suspensions in live mouse embryos. This approach can potentially be used for variety of applications such as guided injections of contrast agents, signaling molecules, pharmacological agents, cell transplantation and extraction, as well as other image-guided micromanipulations. Our studies also reveal novel potential for gold nanoshells in embryonic research.

  5. Circulating Endothelial Cells and Endothelial Progenitor Cells in Pediatric Sepsis.

    Science.gov (United States)

    Zahran, Asmaa Mohamad; Elsayh, Khalid Ibrahim; Mohamad, Ismail Lotfy; Hassan, Gamal Mohamad; Abdou, Madleen Adel A

    2016-03-01

    The aim of the study was to measure the number of circulating endothelial cells (CECs) and circulating endothelial progenitor cells (CEPs) in pediatric patients with sepsis and correlating it with the severity of the disease and its outcome. The study included 19 children with sepsis, 26 with complicated sepsis, and 30 healthy controls. The patients were investigated within 48 hours of pediatric intensive care unit admission together with flow cytometric detection of CECs and CEPs. The levels of both CECs and CEPs were significantly higher in patient with sepsis and complicated sepsis than the controls. The levels of CECs were higher in patients with complicated sepsis, whereas the levels of CEPs were lower in patients with complicated sepsis. Comparing the survival and nonsurvival septic patients, the levels of CEPs were significantly higher in the survival than in nonsurvival patients, whereas the levels of CECs were significantly lower in the survival than in nonsurvival patients. Serum albumin was higher in survival than in nonsurvival patients. Estimation of CECs and CEPs and their correlation with other parameters such as serum albumen could add important information regarding prognosis in septic pediatric patients.

  6. Current Progress with Primate Embryonic Stem Cells

    OpenAIRE

    Byrne, James A.; Mitalipov, Shoukhrat M.; Wolf, Don P

    2006-01-01

    Embryonic stem cells (ESCs) can proliferate indefinitely, maintain an undifferentiated pluripotent state and differentiate into any cell type. Differentiation of ESCs into various specific cell-types may be able to cure or alleviate the symptoms of various degenerative diseases. Unresolved issues regarding maintaining function, possible apoptosis and tumor formation in vivo mean a prudent approach should be taken towards advancing ESCs into human clinical trials. Rhesus macaques provide the i...

  7. Temporal regulation of embryonic M-phases.

    Directory of Open Access Journals (Sweden)

    Franck Chesnel

    2008-02-01

    Full Text Available Temporal regulation of M-phases of the cell cycle requires precise molecular mechanisms that differ among different cells. This variable regulation is particularly clear during embryonic divisions. The first embryonic mitosis in the mouse lasts twice as long as the second one. In other species studied so far (C. elegans, Sphaerechinus granularis, Xenopus laevis, the first mitosis is also longer than the second, yet the prolongation is less pronounced than in the mouse. We have found recently that the mechanisms prolonging the first embryonic M-phase differ in the mouse and in Xenopus embryos. In the mouse, the metaphase of the first mitosis is specifically prolonged by the unknown mechanism acting similarly to the CSF present in oocytes arrested in the second meiotic division. In Xenopus, higher levels of cyclins B participate in the M-phase prolongation, however, without any cell cycle arrest. In Xenopus embryo cell-free extracts, the inactivation of the major M-phase factor, MPF, depends directly on dissociation of cyclin B from CDK1 subunit and not on cyclin B degradation as was thought before. In search for other mitotic proteins behaving in a similar way as cyclins B we made two complementary proteomic screens dedicated to identifying proteins ubiquitinated and degraded by the proteasome upon the first embryonic mitosis in Xenopus laevis. The first screen yielded 175 proteins. To validate our strategy we are verifying now which of them are really ubiquitinated. In the second one, we identified 9 novel proteins potentially degraded via the proteasome. Among them, TCTP (Translationally Controlled Tumor Protein, a 23-kDa protein, was shown to be partially degraded during mitosis (as well as during meiotic exit. We characterized the expression and the role of this protein in Xenopus, mouse and human somatic cells, Xenopus and mouse oocytes and embryos. TCTP is a mitotic spindle protein positively regulating cellular proliferation. Analysis of

  8. Temporal regulation of embryonic M-phases.

    Science.gov (United States)

    Kubiak, Jacek Z; Bazile, Franck; Pascal, Aude; Richard-Parpaillon, Laurent; Polanski, Zbigniew; Ciemerych, Maria A; Chesnel, Franck

    2008-01-01

    Temporal regulation of M-phases of the cell cycle requires precise molecular mechanisms that differ among different cells. This variable regulation is particularly clear during embryonic divisions. The first embryonic mitosis in the mouse lasts twice as long as the second one. In other species studied so far (C. elegans, Sphaerechinus granularis, Xenopus laevis), the first mitosis is also longer than the second, yet the prolongation is less pronounced than in the mouse. We have found recently that the mechanisms prolonging the first embryonic M-phase differ in the mouse and in Xenopus embryos. In the mouse, the metaphase of the first mitosis is specifically prolonged by the unknown mechanism acting similarly to the CSF present in oocytes arrested in the second meiotic division. In Xenopus, higher levels of cyclins B participate in the M-phase prolongation, however, without any cell cycle arrest. In Xenopus embryo cell-free extracts, the inactivation of the major M-phase factor, MPF, depends directly on dissociation of cyclin B from CDK1 subunit and not on cyclin B degradation as was thought before. In search for other mitotic proteins behaving in a similar way as cyclins B we made two complementary proteomic screens dedicated to identifying proteins ubiquitinated and degraded by the proteasome upon the first embryonic mitosis in Xenopus laevis. The first screen yielded 175 proteins. To validate our strategy we are verifying now which of them are really ubiquitinated. In the second one, we identified 9 novel proteins potentially degraded via the proteasome. Among them, TCTP (Translationally Controlled Tumor Protein), a 23-kDa protein, was shown to be partially degraded during mitosis (as well as during meiotic exit). We characterized the expression and the role of this protein in Xenopus, mouse and human somatic cells, Xenopus and mouse oocytes and embryos. TCTP is a mitotic spindle protein positively regulating cellular proliferation. Analysis of other candidates

  9. Hedgehog Signalling in the Embryonic Mouse Thymus

    OpenAIRE

    Barbarulo, Alessandro; Lau, Ching-In; Mengrelis, Konstantinos; Ross, Susan; Solanki, Anisha; Saldaña, José Ignacio; Crompton, Tessa

    2016-01-01

    T cells develop in the thymus, which provides an essential environment for T cell fate\\ud specification, and for the differentiation of multipotent progenitor cells into major histocompatibility\\ud complex (MHC)-restricted, non-autoreactive T cells. Here we review the role of the Hedgehog\\ud signalling pathway in T cell development, thymic epithelial cell (TEC) development, and\\ud thymocyte–TEC cross-talk in the embryonic mouse thymus during the last week of gestation.\\ud

  10. Embryonic stem cell factors and pancreatic cancer.

    Science.gov (United States)

    Herreros-Villanueva, Marta; Bujanda, Luis; Billadeau, Daniel D; Zhang, Jin-San

    2014-03-07

    Pancreatic ductal adenocarcinoma (PDAC), the most common type of pancreatic tumor, is a highly aggressive human cancer with the lowest five-year survival rate of any human maligancy primarily due to its early- metastasis and lack of response to chemotherapy and radiation. Recent research suggests that PDAC cells comprise a hierarchy of tumor cells that develop around a population of cancer stem cells (CSCs), a small and distinct population of cancer cells that mediates tumoregenesis, metastasis and resistance to standard treatments. Thus, CSCs could be a target for more effective treatment options. Interestingly, pancreatic CSCs are subject to regulation by some of key embryonic stem cell (ESC) transctiption factors abberently expressed in PDAC, such as SOX2, OCT4 and NANOG. ESC transcription factors are important DNA-binding proteins present in both embryonic and adult somatic cells. The critical role of these factors in reprogramming processes makes them essential not only for embryonic development but also tumorigenesis. Here we provide an overview of stem cell transcription factors, particularly SOX2, OCT4, and NANOG, on their expression and function in pancreatic cancer. In contrast to embryonic stem cells, in which OCT4 and SOX2 are tightly regulated and physically interact to regulate a wide spectrum of target genes, de novo SOX2 expression alone in pancreatic cancer cells is sufficient to promote self-renewal, de-differentiation and imparting stemness characteristics via impacting specific cell cycle regulatory genes and epithelial-mesnechymal transtion driver genes. Thus, targeting ESC factors, particularly SOX2, could be a worthy strategy for pancreatic cancer therapy.

  11. Directed hepatic differentiation from embryonic stem cells

    OpenAIRE

    Chen, Xuesong; Zeng, Fanyi

    2011-01-01

    The liver is the largest internal organ in mammals, and is important for the maintenance of normal physiological functions of other tissues and organs. Hepatitis, cirrhosis, liver cancer and other chronic liver diseases are serious threats to human health, and these problems are compounded by a scarcity of liver donors for transplantation therapies. Directed differentiation of embryonic stem cells to liver cells is a promising strategy for obtaining hepatocytes that can be used for cell trans...

  12. Embryonic stem cell differentiation: A chromatin perspective

    OpenAIRE

    Rasmussen Theodore P

    2003-01-01

    Abstract Embryonic stem (ES) cells hold immense promise for the treatment of human degenerative disease. Because ES cells are pluripotent, they can be directed to differentiate into a number of alternative cell-types with potential therapeutic value. Such attempts at "rationally-directed ES cell differentiation" constitute attempts to recapitulate aspects of normal development in vitro. All differentiated cells retain identical DNA content, yet gene expression varies widely from cell-type to ...

  13. A microscopic view on the renal endothelial glycocalyx

    NARCIS (Netherlands)

    Dane, M.J.; Berg, B.M. van den; Lee, D.H.; Boels, M.G.; Tiemeier, G.L.; Avramut, M.C.; Zonneveld, A.J. van; Vlag, J. van der; Vink, H.; Rabelink, T.J.

    2015-01-01

    Endothelial cells perform key homeostatic functions such as regulating blood flow, permeability, and aiding immune surveillance for pathogens. While endothelial activation serves normal physiological adaptation, maladaptation of these endothelial functions has been identified as an important effecto

  14. A trade-off between embryonic development rate and immune function of avian offspring is concealed by embryonic temperature

    Science.gov (United States)

    Martin, Thomas E.; Arriero, Elena; Majewska, Ania

    2011-01-01

    Long embryonic periods are assumed to reflect slower intrinsic development that are thought to trade off to allow enhanced physiological systems, such as immune function. Yet, the relatively rare studies of this trade-off in avian offspring have not found the expected trade-off. Theory and tests have not taken into account the strong extrinsic effects of temperature on embryonic periods of birds. Here, we show that length of the embryonic period did not explain variation in two measures of immune function when temperature was ignored, based on studies of 34 Passerine species in tropical Venezuela (23 species) and north temperate Arizona (11 species). Variation in immune function was explained when embryonic periods were corrected for average embryonic temperature, in order to better estimate intrinsic rates of development. Immune function of offspring trades off with intrinsic rates of embryonic development once the extrinsic effects of embryonic temperatures are taken into account.

  15. [Heart tissue from embryonic stem cells].

    Science.gov (United States)

    Zimmermann, W-H

    2008-09-01

    Embryonic stem cells can give rise to all somatic cells, making them an attractive cell source for tissue engineering applications. The propensity of cells to form tissue-like structures in a culture dish has been well documented. We and others made use of this intrinsic property to generate bioartificial heart muscle. First proof-of-concept studies involved immature heart cells mainly from fetal chicken, neonatal rats and mice. They eventually provided evidence that force-generating heart muscle can be engineered in vitro. Recently, the focus shifted to the application of stem cells to eventually enable the generation of human heart muscle and reach following long-term goals: (1) development of a simplified in vitro model of heart muscle development; (2) generation of a human test-bed for drug screening and development; (3) allocation of surrogate heart tissue to myocardial repair applications. This overview will provide the background for cell-based myocardial repair, introduce the main myocardial tissue engineering concepts, discuss the use of embryonic and non-embryonic stem cells, and lays out the potential direct and indirect therapeutic use of human tissue engineered myocardium.

  16. Embryonic mortality in buffalo naturally mated

    Directory of Open Access Journals (Sweden)

    G. Campanile

    2010-02-01

    Full Text Available The aim of this work was to evaluate the incidence of embryonic mortality in three different period of year in buffaloes naturally mated. The trial was carried out in a buffalo farm located in Caserta province between 2000-2006. In this period were registered natural insemination on 200 buffaloes. Pregnancy diagnosis was carried out on Day 30, confirmed on Day 45 and every 15th days until 90 days after natural mating. Buffaloes that were pregnant on Day 30 but not on Day 45 or Day 90 were considered to have undergone embryonic (EM or fetal mortality (FM respectively. EM and FM were 8.8% and 13.4% respectively throughout the experimental period. A high incidence (P<0.01 of FM was found in the transitional period (December-March than in other months of the year. The incidence of embryonic mortality was significantly (P<0.01 higher between 28-60 days of gestation and lower after 71 day of gestation. The higher fetal mortality found in this study could be due the lower serum levels of progesterone normally found in transitional period in buffalo cows.

  17. Embryonic development of Pelteobagrus fulvidraco (Richardson, 1846)

    Institute of Scientific and Technical Information of China (English)

    WANG Weimin; Khalid ABBAS; YAN Ansheng

    2006-01-01

    For production enhancement and procedure upgrade, the developmental phases of laboratory-reared eggs of catfish Pelteobagrus fulvidraco were investigated. Twenty mature females and 10 males were collected from Dadongmen wholesale fisheries market in Wuhan City on May 8, 2003. Zygotes were stripped from mature fish after hormone-induced ovulation, fertilized, and incubated through whole embryonic development. The fertilized eggs were stocked in density of 100 eggs/L in white square tanks of 10 L. Incubation water was dechlorinated tap water with continuous aeration. The tanks were lit directly with 60 W fluorescent bulbs with a 12 light: 12 dark photoperiod. Water temperature, dissolved oxygen and pH were 29.0±0.5℃, 6.7±0.4 mg/L and 7.4±0.2, respectively. The results showed that the eggs of P. fulvidraco were yellow, sticky and contained much yolk. The mean diameter of fertilized eggs was 2.03 mm. At the water temperature of 29.0±0.5 ℃, the ontogenesis spent about33 h after fertilization.From fertilization to hatching, the embryonic development can be divided into 30-40 phases, which varies in the emphasis and direction of development. The detailed embryonic movement was also described.

  18. Informing tendon tissue engineering with embryonic development

    Science.gov (United States)

    Glass, Zachary A.; Schiele, Nathan R.; Kuo, Catherine K.

    2014-01-01

    Tendon is a strong connective tissue that transduces muscle-generated forces into skeletal motion. In fulfilling this role, tendons are subjected to repeated mechanical loading and high stress, which may result in injury. Tissue engineering with stem cells offers the potential to replace injured/damaged tissue with healthy, new living tissue. Critical to tendon tissue engineering is the induction and guidance of stem cells towards the tendon phenotype. Typical strategies have relied on adult tissue homeostatic and healing factors to influence stem cell differentiation, but have yet to achieve tissue regeneration. A novel paradigm is to use embryonic developmental factors as cues to promote tendon regeneration. Embryonic tendon progenitor cell differentiation in vivo is regulated by a combination of mechanical and chemical factors. We propose that these cues will guide stem cells to recapitulate critical aspects of tenogenesis and effectively direct the cells to differentiate and regenerate new tendon. Here, we review recent efforts to identify mechanical and chemical factors of embryonic tendon development to guide stem/progenitor cell differentiation toward new tendon formation, and discuss the role this work may have in the future of tendon tissue engineering. PMID:24484642

  19. Informing tendon tissue engineering with embryonic development.

    Science.gov (United States)

    Glass, Zachary A; Schiele, Nathan R; Kuo, Catherine K

    2014-06-27

    Tendon is a strong connective tissue that transduces muscle-generated forces into skeletal motion. In fulfilling this role, tendons are subjected to repeated mechanical loading and high stress, which may result in injury. Tissue engineering with stem cells offers the potential to replace injured/damaged tissue with healthy, new living tissue. Critical to tendon tissue engineering is the induction and guidance of stem cells towards the tendon phenotype. Typical strategies have relied on adult tissue homeostatic and healing factors to influence stem cell differentiation, but have yet to achieve tissue regeneration. A novel paradigm is to use embryonic developmental factors as cues to promote tendon regeneration. Embryonic tendon progenitor cell differentiation in vivo is regulated by a combination of mechanical and chemical factors. We propose that these cues will guide stem cells to recapitulate critical aspects of tenogenesis and effectively direct the cells to differentiate and regenerate new tendon. Here, we review recent efforts to identify mechanical and chemical factors of embryonic tendon development to guide stem/progenitor cell differentiation toward new tendon formation, and discuss the role this work may have in the future of tendon tissue engineering.

  20. Identification and Expression Analysis of Zebrafish (Danio rerio E-Selectin during Embryonic Development

    Directory of Open Access Journals (Sweden)

    Guijin Sun

    2015-10-01

    Full Text Available In this study, we cloned the full-length cDNA of E-selectin of zebrafish (Danio rerio, analyzed its expression pattern and preliminarily explored its biological function. Zebrafish E-selectin cDNA is 3146 bp and encodes a putative 871 amino acid protein. All structural domains involved in E-selectin function are conserved in the putative protein. Whole-mount in situ hybridization of zebrafish at 24 and 48 h post-fertilization (hpf revealed E-selectin expression mainly in vascular/endothelial progenitor cells in the posterior trunk and blood cells in the intermediate cell mass and posterior cardinal vein regions. Real-time quantitative RT-PCR analysis detected E-selectin expression at 0.2, 24 and 48 hpf and significantly decreased from 48 to 72 hpf. The expression of E-selectin, tumor necrosis factor-α and interleukin-1β was significantly upregulated at 22 to 72 h after induction with bacterial lipopolysaccharide. Thus, the structure of E-selectin protein is highly conserved among species, and E-selectin may be involved in embryonic development and essential for hematopoiesis and angiogenesis during embryonic development in zebrafish. Furthermore, we provide the first evidence of inflammatory mediators inducing E-selectin expression in non-mammalian vertebrates, which suggests that zebrafish E-selectin may be involved in inflammation and probably has similar biological function to mammalian E-selectin.

  1. Role of Vitamin A/Retinoic Acid in Regulation of Embryonic and Adult Hematopoiesis

    Science.gov (United States)

    Cañete, Ana; Cano, Elena; Muñoz-Chápuli, Ramón; Carmona, Rita

    2017-01-01

    Vitamin A is an essential micronutrient throughout life. Its physiologically active metabolite retinoic acid (RA), acting through nuclear retinoic acid receptors (RARs), is a potent regulator of patterning during embryonic development, as well as being necessary for adult tissue homeostasis. Vitamin A deficiency during pregnancy increases risk of maternal night blindness and anemia and may be a cause of congenital malformations. Childhood Vitamin A deficiency can cause xerophthalmia, lower resistance to infection and increased risk of mortality. RA signaling appears to be essential for expression of genes involved in developmental hematopoiesis, regulating the endothelial/blood cells balance in the yolk sac, promoting the hemogenic program in the aorta-gonad-mesonephros area and stimulating eryrthropoiesis in fetal liver by activating the expression of erythropoietin. In adults, RA signaling regulates differentiation of granulocytes and enhances erythropoiesis. Vitamin A may facilitate iron absorption and metabolism to prevent anemia and plays a key role in mucosal immune responses, modulating the function of regulatory T cells. Furthermore, defective RA/RARα signaling is involved in the pathogenesis of acute promyelocytic leukemia due to a failure in differentiation of promyelocytes. This review focuses on the different roles played by vitamin A/RA signaling in physiological and pathological mouse hematopoiesis duddurring both, embryonic and adult life, and the consequences of vitamin A deficiency for the blood system. PMID:28230720

  2. Effect of VEGF on Neural Differentiation of Human Embryonic Stem Cells in vitro

    Institute of Scientific and Technical Information of China (English)

    Shujie JIAO; Huifang XU; Jie XU; Yanqiang ZHAN; Suming ZHANG

    2009-01-01

    The effects of vascular endothelial growth factor (VEGF) on neural differentiation of human embryonic stem cells (hESCs) in vitro and the possible mechanism were observed. The hESCs lines,TJMU1 and TJMU2, were established and stored by our laboratory, hESCs differentiated into neuronal cells through embryonic body formation. In this induction process, hESCs were divided into three groups: group A, routine induction; group B, routine induction+10 ng/mL VEGF; group C, routine in-duction+10 ng/mL VEGF+10 ng/mL VEGFR2/Fc. OCT4, Nestin and GFAP in each group were de-tected by RT-PCR, and the cells expressing Nestin and GFAP were counted by immunofluorescence.The percentage of Nestin positive cells in group B was significantly higher than in groups A and C,while the percentage of GFAP positive cells in group B was significantly lower than in groups A and C (P0.05). It was concluded that VEGF, via VEGFR2, stimulated the neural differentiation of hESCs in vitro.

  3. Role of Vitamin A/Retinoic Acid in Regulation of Embryonic and Adult Hematopoiesis

    Directory of Open Access Journals (Sweden)

    Ana Cañete

    2017-02-01

    Full Text Available Vitamin A is an essential micronutrient throughout life. Its physiologically active metabolite retinoic acid (RA, acting through nuclear retinoic acid receptors (RARs, is a potent regulator of patterning during embryonic development, as well as being necessary for adult tissue homeostasis. Vitamin A deficiency during pregnancy increases risk of maternal night blindness and anemia and may be a cause of congenital malformations. Childhood Vitamin A deficiency can cause xerophthalmia, lower resistance to infection and increased risk of mortality. RA signaling appears to be essential for expression of genes involved in developmental hematopoiesis, regulating the endothelial/blood cells balance in the yolk sac, promoting the hemogenic program in the aorta-gonad-mesonephros area and stimulating eryrthropoiesis in fetal liver by activating the expression of erythropoietin. In adults, RA signaling regulates differentiation of granulocytes and enhances erythropoiesis. Vitamin A may facilitate iron absorption and metabolism to prevent anemia and plays a key role in mucosal immune responses, modulating the function of regulatory T cells. Furthermore, defective RA/RARα signaling is involved in the pathogenesis of acute promyelocytic leukemia due to a failure in differentiation of promyelocytes. This review focuses on the different roles played by vitamin A/RA signaling in physiological and pathological mouse hematopoiesis duddurring both, embryonic and adult life, and the consequences of vitamin A deficiency for the blood system.

  4. Ethanol disrupts the formation of hypochord and dorsal aorta during the development of embryonic zebrafish

    Institute of Scientific and Technical Information of China (English)

    QIAN Linxi; WANG Yuexiang; JIANG Qiu; ZHONG Tao; SONG Houyan

    2005-01-01

    Exposure to ethanol during human embryonic period has severe teratogenic effects on the cardiovascular system. In our study, we demonstrated that ethanol of gradient concentrations can interfere with the establishment of circulatory system in embryonic zebrafish. The effective concentration to cause 50% malformations (EC50) was 182.5 mmol/L. The ethanol pulse exposure experiment displayed that dome stage during embryogenesis is the sensitive time window to ethanol. It is found that 400 mmol/L ethanol pulse exposure can induce circulatory defects in 43% treated embryos. We ruled out the possibility that ethanol can interfere with the process of hematopoiesis in zebrafish. By employing in situ hybridization with endothelial biomarker (Flk-1), we revealed that ethanol disrupts the establishment of trunk axial vasculature, but has no effect on cranial vessels. Combined with the results of semi-thin histological sections, the in situ hybridization experiments with arterial and venous biomarkers (ephrinB2, ephB4) suggested that ethanol mainly interrupts the development of dorsal aorta while has little effect on axial vein. Further study indicated the negative influence of ethanol on the development of hypochord in zebrafish. The consequent lack of vasculogenic factors including Radar and Ang-1 partly explains the defects in formation and integrity of dorsal aorta. These results provide important clues to the study of adverse effects of ethanol on the cardiovascular development in human fetus.

  5. Lumican reduces tumor growth via induction of fas-mediated endothelial cell apoptosis.

    Science.gov (United States)

    Williams, Kent E; Fulford, Logan A; Albig, Allan R

    2010-11-18

    Matrikines are important components of tumor microenvironments that integrate communication between extracellular matricies and membrane-bound receptors thereby regulating cellular behaviors. One such matrikine that is differentially expressed in cancer microenvironments is the extracellular matrix protein lumican; however its precise role in cancer remains ambiguous. To study the effects of lumican on cancer cells, we created lumican-overexpressing cell lines from murine fibrosarcoma (MCA102) and pancreatic adenocarcinoma (Pan02) cells. Lumican overexpression in Pan02 cells increased invasiveness, decreased soft agar colony size, and increased proliferation. Conversely in MCA102 cells, lumican decreased invasiveness, increased soft agar colony size, but did not influence proliferation. In contrast to these pleiotropic in vitro results, lumican overexpression within the in vivo tumor microenvironment produced uniformly smaller tumors. Importantly, reduced tumor size was correlated with reduced vascular density. Consistent with lumican's proposed anti-angiogenic activity, lumican increased endothelial cell apoptosis. Importantly, lumican was previously shown to influence Fas expression and our results show that lumican enhanced Fas mediated endothelial cell apoptosis although we were unable to detect any difference in Fas or Fas ligand expression between lumican-overexpressing and control cells. Interestingly, lumican had no effect on MCA102 apoptosis, suggesting that the observed reduction in tumor size is specifically due to endothelial cell apoptosis rather than a direct effect on the cancerous cells themselves. Therefore, this study is the first to demonstrate a causal relationship between tumor reduction and lumican's effect on angiogenesis as opposed to an effect on the cancerous cells themselves.

  6. Effect of photobiomodulation on endothelial cell exposed to Bothrops jararaca venom.

    Science.gov (United States)

    Franco, Ana Tereza Barufi; Silva, Luciana Miato Gonçalves; Costa, Marcília Silva; Zamuner, Silvia Fernanda; Vieira, Rodolfo Paula; de Fatima Pereira Teixeira, Catarina; Zamuner, Stella Regina

    2016-07-01

    Bleeding is a common feature in envenoming caused by Bothrops snake venom due to extensive damage to capillaries and venules, producing alterations in capillary endothelial cell morphology. It has been demonstrated, in vivo, that photobiomodulation (PBM) decreases hemorrhage after venom inoculation; however, the mechanism is unknown. Thus, the objective was to investigate the effects of PBM on a murine endothelial cell line (tEnd) exposed to Bothrops jararaca venom (BjV). Cells were exposed to BjV and irradiated once with either 660- or 780-nm wavelength laser light at energy densities of 4 and 5 J/cm(2), respectively, and irradiation time of 10 s. Cell integrity was analyzed by crystal violet and cell viability/mitochondrial metabolism by MTT assay. The release of lactic dehydrogenase (LDH) was quantified as a measure of cell damage. In addition, cytokine IL1-β levels were measured in the supernatant. PBM at 660 and 780 nm wavelength was able to increase cellular viability and decrease the release of LDH and the loss of cellular integrity. In addition, the concentration of pro-inflammatory cytokine IL1-β was reduced after PBM by both wavelengths. The data reported herein indicates that irradiation with red or near-infrared laser resulted in protection on endothelial cells after exposure to Bothrops venom and could be, at least in part, a reasonable explanation by the beneficial effects of PBM inhibiting the local effects induced by Bothrops venoms, in vivo.

  7. Bone morphogenetic protein receptor II regulates pulmonary artery endothelial cell barrier function.

    Science.gov (United States)

    Burton, Victoria J; Ciuclan, Loredana I; Holmes, Alan M; Rodman, David M; Walker, Christoph; Budd, David C

    2011-01-06

    Mutations in bone morphogenetic protein receptor II (BMPR-II) underlie most heritable cases of pulmonary arterial hypertension (PAH). However, less than half the individuals who harbor mutations develop the disease. Interestingly, heterozygous null BMPR-II mice fail to develop PAH unless an additional inflammatory insult is applied, suggesting that BMPR-II plays a fundamental role in dampening inflammatory signals in the pulmonary vasculature. Using static- and flow-based in vitro systems, we demonstrate that BMPR-II maintains the barrier function of the pulmonary artery endothelial monolayer suppressing leukocyte transmigration. Similar findings were also observed in vivo using a murine model with loss of endothelial BMPR-II expression. In vitro, the enhanced transmigration of leukocytes after tumor necrosis factor α or transforming growth factor β1 stimulation was CXCR2 dependent. Our data define how loss of BMPR-II in the endothelial layer of the pulmonary vasculature could lead to a heightened susceptibility to inflammation by promoting the extravasation of leukocytes into the pulmonary artery wall. We speculate that this may be a key mechanism involved in the initiation of the disease in heritable PAH that results from defects in BMPR-II expression.

  8. C-peptide protects against hyperglycemic memory and vascular endothelial cell apoptosis.

    Science.gov (United States)

    Bhatt, Mahendra Prasad; Lee, Yeon-Ju; Jung, Se-Hui; Kim, Yong Ho; Hwang, Jong Yun; Han, Eun-Taek; Park, Won Sun; Hong, Seok-Ho; Kim, Young-Myeong; Ha, Kwon-Soo

    2016-10-01

    C-peptide exerts protective effects against diabetic complications; however, its role in inhibiting hyperglycemic memory (HGM) has not been elucidated. We investigated the beneficial effect of C-peptide on HGM-induced vascular damage in vitro and in vivo using human umbilical vein endothelial cells and diabetic mice. HGM induced apoptosis by persistent generation of intracellular ROS and sustained formation of ONOO(-) and nitrotyrosine. These HGM-induced intracellular events were normalized by treatment with C-peptide, but not insulin, in endothelial cells. C-peptide also inhibited persistent upregulation of p53 and activation of mitochondrial adaptor p66(shc) after glucose normalization. Further, C-peptide replacement therapy prevented persistent generation of ROS and ONOO(-) in the aorta of diabetic mice whose glucose levels were normalized by the administration of insulin. C-peptide, but not insulin, also prevented HGM-induced endothelial apoptosis in the murine diabetic aorta. This study highlights a promising role for C-peptide in preventing HGM-induced intracellular events and diabetic vascular damage.

  9. Impaired endothelial shear stress induces podosome assembly via VEGF up-regulation.

    Science.gov (United States)

    Fey, Theres; Schubert, Kai Michael; Schneider, Holger; Fein, Evelyn; Kleinert, Eike; Pohl, Ulrich; Dendorfer, Andreas

    2016-08-01

    Podosomes are dynamic cytoskeletal membrane structures with local adhesive and proteolytic activity. They are critically involved in angiogenesis and vascular adaptive growth. Here, we studied in HUVECs and murine small vessels whether shear stress controls podosome assembly and local proteolytic activity. Podosomes were characterized by immunohistochemistry, and their proteolytic activity was assessed as degradation imprints in fluorescent gelatin that was used as growth substrate. Compared with controls (10 dyn/cm(2)), the number of podosomes formed per time was doubled when cells were exposed to low shear stress (0.3 dyn/cm(2)) or even increased 5-fold under static conditions. This was a result of an enhanced expression of VEGF after reduction of shear stress. Consequently, enhanced podosome formation could be prevented by a VEGF receptor antagonist as well by interruption of VEGF signaling via inhibition of PI3K, Src, or p38. Increase of podosome assembly went along with significantly augmented cell motility. In vivo experiments in mouse arteries confirmed increased endothelial podosome numbers when shear stress was abolished by vessel occlusion. We conclude that shear stress, by reducing VEGF release, inhibits podosome assembly. Hence, endothelial cell-mediated matrix proteolysis and migratory activity are inhibited, thereby stabilizing the structure of the vessel wall.-Fey, T., Schubert, K. M., Schneider, H., Fein, E., Kleinert, E., Pohl, U., Dendorfer, A. Impaired endothelial shear stress induces podosome assembly via VEGF up-regulation.

  10. Elastogenic protein expression of a highly elastic murine spinal ligament: the ligamentum flavum.

    Directory of Open Access Journals (Sweden)

    Jeffrey P Brown

    Full Text Available Spinal ligaments, such as the ligamentum flavum (LF, are prone to degeneration and iatrogenic injury that can lead to back pain and nerve dysfunction. Repair and regeneration strategies for these tissues are lacking, perhaps due to limited understanding of spinal ligament formation, the elaboration of its elastic fibers, maturation and homeostasis. Using immunohistochemistry and histology, we investigated murine LF elastogenesis and tissue formation from embryonic to mature postnatal stages. We characterized the spatiotemporal distribution of the key elastogenic proteins tropoelastin, fibrillin-1, fibulin-4 and lysyl oxidase. We found that elastogenesis begins in utero with the microfibril constituent fibrillin-1 staining intensely just before birth. Elastic fibers were first detected histologically at postnatal day (P 7, the earliest stage at which tropoelastin and fibulin-4 stained intensely. From P7 to P28, elastic fibers grew in diameter and became straighter along the axis. The growth of elastic fibers coincided with intense staining of tropoelastin and fibulin-4 staining, possibly supporting a chaperone role for fibulin-4. These expression patterns correlated with reported skeletal and behavioral changes during murine development. This immunohistochemical characterization of elastogenesis of the LF will be useful for future studies investigating mechanisms for elastogenesis and developing new strategies for treatment or regeneration of spinal ligaments and other highly elastic tissues.

  11. Murine "cardiospheres" are not a source of stem cells with cardiomyogenic potential

    DEFF Research Database (Denmark)

    Andersen, Ditte Caroline; Andersen, Peter; Schneider, Mikael;

    2009-01-01

    in vitro culture, fluorescence-activated cell sorting, and immunofluorescence, we demonstrate that these CSs are generated by cellular aggregation of GATA-4(+)/collagen I(+)/alpha-smooth muscle actin (SMA)(+)/CD45(-) cells rather than by clonal cell growth. In contrast, we found that the previously...... proposed CS-forming cells, dubbed phase bright cells, were GATA-4(-)/collagen I(-)/alpha-SMA(-)/CD45(+) and unable to form CSs by themselves. Phenotypically, the CS cells largely resembled fibroblasts, and they lacked cardiomyogenic as well as endothelial differentiation potential. Our data imply...... that the murine CS model is unsuitable as a source of CSCs with cardiomyogenic potential, a result that is in contrast to previously published data. We therefore suggest, that human CSs should be further characterized with respect to phenotype and differentiation potential before initiating human trials....

  12. Overview of very small embryonic-like stem cells (VSELs) and methodology of their identification and isolation by flow cytometric methods.

    Science.gov (United States)

    Zuba-Surma, Ewa K; Ratajczak, Mariusz Z

    2010-01-01

    The protocols presented here describe the procedures employed to identify and isolate very small embryonic-like stem cells (VSELs) using flow cytometric technologies including fluorescence-activated cell sorting (FACS). We describe the recommended steps in detail for their successful identification and isolation from adult tissues. These protocols were initially established to isolate such cells from murine bone marrow (BM) and human cord blood (CB) and may also be employed to isolate these primitive cells from other adult organs and embryonic tissues. Here, we focus on some critical parameters/key points required for the successful identification and purification of these rare cells by employing classical flow cytometry. In the last part of this unit, we also discuss a novel flow cytometric tool, ImageStream, an imaging flow cytometer, which allows better identification and morphological analysis of sorted cells.

  13. MiR-24 is required for hematopoietic differentiation of mouse embryonic stem cells.

    Directory of Open Access Journals (Sweden)

    Lynn Roy

    2015-01-01

    Full Text Available Overexpression of miRNA, miR-24, in mouse hematopoietic progenitors increases monocytic/ granulocytic differentiation and inhibits B cell development. To determine if endogenous miR-24 is required for hematopoiesis, we antagonized miR-24 in mouse embryonic stem cells (ESCs and performed in vitro differentiations. Suppression of miR-24 resulted in an inability to produce blood and hematopoietic progenitors (HPCs from ESCs. The phenotype is not a general defect in mesoderm production since we observe production of nascent mesoderm as well as mesoderm derived cardiac muscle and endothelial cells. Results from blast colony forming cell (BL-CFC assays demonstrate that miR-24 is not required for generation of the hemangioblast, the mesoderm progenitor that gives rise to blood and endothelial cells. However, expression of the transcription factors Runx1 and Scl is greatly reduced, suggesting an impaired ability of the hemangioblast to differentiate. Lastly, we observed that known miR-24 target, Trib3, is upregulated in the miR-24 antagonized embryoid bodies (EBs. Overexpression of Trib3 alone in ESCs was able to decrease HPC production, though not as great as seen with miR-24 knockdown. These results demonstrate an essential role for miR-24 in the hematopoietic differentiation of ESCs. Although many miRNAs have been implicated in regulation of hematopoiesis, this is the first miRNA observed to be required for the specification of mammalian blood progenitors from early mesoderm.

  14. Abcg2-Labeled Cells Contribute to Different Cell Populations in the Embryonic and Adult Heart

    Science.gov (United States)

    Doyle, Michelle J.; Maher, Travis J.; Li, Qinglu; Garry, Mary G.; Sorrentino, Brian P.

    2016-01-01

    ATP-binding cassette transporter subfamily G member 2 (Abcg2)-expressing cardiac-side population cells have been identified in the developing and adult heart, although the role they play in mammalian heart growth and regeneration remains unclear. In this study, we use genetic lineage tracing to follow the cell fate of Abcg2-expressing cells in the embryonic and adult heart. During cardiac embryogenesis, the Abcg2 lineage gives rise to multiple cardiovascular cell types, including cardiomyocytes, endothelial cells, and vascular smooth muscle cells. This capacity for Abcg2-expressing cells to contribute to cardiomyocytes decreases rapidly during the postnatal period. We further tested the role of the Abcg2 lineage following myocardial injury. One month following ischemia reperfusion injury, Abcg2-expressing cells contributed significantly to the endothelial cell lineage, however, there was no contribution to regenerated cardiomyocytes. Furthermore, consistent with previous results showing that Abcg2 plays an important cytoprotective role during oxidative stress, we show an increase in Abcg2 labeling of the vasculature, a decrease in the scar area, and a moderate improvement in cardiac function following myocardial injury. We have uncovered a difference in the capacity of Abcg2-expressing cells to generate the cardiovascular lineages during embryogenesis, postnatal growth, and cardiac regeneration. PMID:26573225

  15. Human but not murine toll-like receptor 2 discriminates between tri-palmitoylated and tri-lauroylated peptides.

    Science.gov (United States)

    Grabiec, Alina; Meng, Guangxun; Fichte, Sylvia; Bessler, Wolfgang; Wagner, Hermann; Kirschning, Carsten J

    2004-11-12

    Toll-like receptors (TLRs) mediate activation of the immune system upon challenge with microbial agonists, components of disintegrating cells of the body, or metabolic intermediates of lipidic nature. Comparison of murine (m) and human (h) TLR2 primary sequences revealed 65% of identical residues within the extracellular domains in contrast to 84% in the intracellular domains. Comparative analysis of TLR2-driven cell activation by various TLR2 agonists showed that the tri-lauroylated lipopeptide analog (Lau(3)CSK(4)) is recognized efficiently through mTLR2 but not hTLR2. Genetically complemented human embryonic kidney 293 cells and murine TLR2(-/-) embryonic fibroblasts, as well as human and murine macrophage cells, were used for this analysis. In contrast to cellular activation, which depended on blockable access of the TLR2-ligand to TLR2, cellular uptake of Lau(3)CSK(4) and tri-palmitoylated peptide (P(3)CSK(4)) was independent of TLR2. A low-conserved region spanning from leucine-rich repeat (LRR) motif 7 to 10 was found to control TLR2 species-specific cell activation. Exchange of mLRR8 for hLRR8 in mTLR2 abrogated mTLR2-typical cell activation upon cellular challenge with Lau(3)CSK(4) but not P(3)CSK(4), implicating mLRR8 as a central element of Lau(3)CSK(4) recognition. The point mutation L112P within LRR3 abrogated hTLR2-dependent recognition of lipopeptides but merely attenuated mTLR2 function, whereas deletion of the N-terminal third of each LRR-rich domain (LRRs 1 to 7) had the opposite effect on P(3)CSK(4) recognition. Despite similar domain structure of both TLR2 molecules, species-specific properties thus exist. Our results imply distinct susceptibilities of humans and mice to challenge with specific TLR2 ligands.

  16. Vascular endothelial dysfunction and pharmacological treatment

    Institute of Scientific and Technical Information of China (English)

    Jin; Bo; Su

    2015-01-01

    The endothelium exerts multiple actions involving regulation of vascular permeability and tone, coagulation and fibrinolysis, inflammatory and immunological reactions and cell growth. Alterations of one or more such actions may cause vascular endothelial dysfunction. Different risk factors such as hypercholesterolemia, homocystinemia, hyperglycemia, hypertension, smo-king, inflammation, and aging contribute to the development of endothelial dysfunction. Mechanisms underlying endothelial dysfunction are multiple, including impaired endothelium-derived vasodilators, enhanced endothelium-derived vasoconstrictors, over production of reactive oxygen species and reactive nitrogen species, activation of inflammatory and immune reactions, and imbalance of coagulation and fibrinolysis. Endothelial dysfunction occurs in many cardiovascular diseases, which involves different mechanisms, depending on specific risk factors affecting the disease. Among these mechanisms, a reduction in nitric oxide(NO) bioavailability plays a central role in the development of endothelial dysfunction because NO exerts diverse physiological actions, including vasodilation, anti-inflammation, antiplatelet, antiproliferation and antimigration. Experimental and clinical studies have demonstrated that a variety of currently used or investigational drugs, such as angiotensin-converting enzyme inhibitors, angiotensin AT1 receptors blockers, angiotensin-(1-7), antioxidants, beta-blockers, calcium channel blockers, endothelial NO synthase enhancers, phosphodiesterase 5 inhibitors, sphingosine-1-phosphate and statins, exert endothelial protective effects. Due to the difference in mechanisms of action, these drugs need to be used according to specific mechanisms underlying endothelial dysfunction of the disease.

  17. PPAR Gamma and Angiogenesis: Endothelial Cells Perspective

    Directory of Open Access Journals (Sweden)

    Jerzy Kotlinowski

    2016-01-01

    Full Text Available We summarize the current knowledge concerning PPARγ function in angiogenesis. We discuss the mechanisms of action for PPARγ and its role in vasculature development and homeostasis, focusing on endothelial cells, endothelial progenitor cells, and bone marrow-derived proangiogenic cells.

  18. Endothelial dysfunction after non-cardiac surgery

    DEFF Research Database (Denmark)

    Søndergaard, E S; Fonnes, S; Gögenur, I

    2015-01-01

    BACKGROUND: More than 50% of patients with increased troponin levels after non-cardiac surgery have an impaired endothelial function pre-operatively. Non-invasive markers of endothelial function have been developed for the assessment of endothelial dysfunction. The aim of this paper was to system......BACKGROUND: More than 50% of patients with increased troponin levels after non-cardiac surgery have an impaired endothelial function pre-operatively. Non-invasive markers of endothelial function have been developed for the assessment of endothelial dysfunction. The aim of this paper...... was to systematically review the literature to evaluate the association between non-cardiac surgery and non-invasive markers of endothelial function. METHODS: A systematic search was conducted in MEDLINE, EMBASE and Cochrane Library Database according to the PRISMA guidelines. Endothelial dysfunction was described only...... with non-invasive measurements done both pre- and post-operatively and published in English. All types of non-cardiac surgery and both men and women of all ages were included. RESULTS: We found 1722 eligible studies in our search, and of these, five studies fulfilled our inclusion and exclusion criteria...

  19. Cloning and expression of murine immune interferon cDNA.

    OpenAIRE

    1983-01-01

    The murine immune interferon (IFN-gamma) gene was cloned and expressed under control of the simian virus 40 early promoter in the monkey COS-1 cell line. A protein is secreted from these cells having the biological, antigenic, and biochemical characteristics of natural murine IFN-gamma. Cloned murine IFN-gamma cDNAs were obtained by using RNA from both mitogen-induced murine spleens and the transfected COS cells, and both code for identical proteins. The mature murine IFN-gamma encoded is 136...

  20. Vascular endothelial growth factor enhances macrophage clearance of apoptotic cells

    Science.gov (United States)

    Dalal, Samay; Horstmann, Sarah A.; Richens, Tiffany R.; Tanaka, Takeshi; Doe, Jenna M.; Boe, Darren M.; Voelkel, Norbert F.; Taraseviciene-Stewart, Laimute; Janssen, William J.; Lee, Chun G.; Elias, Jack A.; Bratton, Donna; Tuder, Rubin M.; Henson, Peter M.; Vandivier, R. William

    2012-01-01

    Efficient clearance of apoptotic cells from the lung by alveolar macrophages is important for the maintenance of tissue structure and function. Lung tissue from humans with emphysema contains increased numbers of apoptotic cells and decreased levels of vascular endothelial growth factor (VEGF). Mice treated with VEGF receptor inhibitors have increased numbers of apoptotic cells and develop emphysema. We hypothesized that VEGF regulates apoptotic cell clearance by alveolar macrophages (AM) via its interaction with VEGF receptor 1 (VEGF R1). Our data show that the uptake of apoptotic cells by murine AMs and human monocyte-derived macrophages is inhibited by depletion of VEGF and that VEGF activates Rac1. Antibody blockade or pharmacological inhibition of VEGF R1 activity also decreased apoptotic cell uptake ex vivo. Conversely, overexpression of VEGF significantly enhanced apoptotic cell uptake by AMs in vivo. These results indicate that VEGF serves a positive regulatory role via its interaction with VEGF R1 to activate Rac1 and enhance AM apoptotic cell clearance. PMID:22307908

  1. Uncovering the post-embryonic functions of gametophytic- and embryonic-lethal genes.

    Science.gov (United States)

    Candela, Héctor; Pérez-Pérez, José Manuel; Micol, José Luis

    2011-06-01

    An estimated 500-1 000 Arabidopsis (Arabidopsis thaliana) genes mutate to embryonic lethality. In addition, several hundred mutations have been identified that cause gametophytic lethality. Thus, a significant fraction of the ∼25,000 protein-coding genes in Arabidopsis are indispensable to the early stages of the diploid phase or to the haploid gametophytic phase. The expression patterns of many of these genes indicate that they also act later in development but, because the mutants die at such early stages, conventional methods limit the study of their roles in adult diploid plants. Here, we describe the toolset that allows researchers to assess the post-embryonic functions of plant genes for which only gametophytic- and embryonic-lethal alleles have been isolated. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Structure of the murine Thy-1 gene

    NARCIS (Netherlands)

    V. Giguere; K-I. Isobe; F.G. Grosveld (Frank)

    1985-01-01

    textabstractWe have cloned the murine Thy-1.1 (AKR) and Thy-1.2 (Balb/c) genes. The complete exon/intron structure and the nucleotide sequence of the Thy-1.2 gene was determined. The gene contains four exons and three intervening sequences. The complete transcriptional unit gives rise to a tissue an

  3. Reemergence of Murine Typhus in the US

    Centers for Disease Control (CDC) Podcasts

    2015-04-21

    Dr. Lucas Blanton discusses the Reemergence of Murine Typhus in Galveston Texas in 2013.  Created: 4/21/2015 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 4/27/2015.

  4. Quantitative and qualitative in vitro analysis of the stem cell potential of hematopoietic cells purified from murine skeletal muscle

    Institute of Scientific and Technical Information of China (English)

    Celine Haond; Fran(c)oise Farace; Martine Guillier; Yann Lécluse; Frederic Mazurier; William Vainchenker; Ali G Turhan

    2007-01-01

    The murine skeletal muscle contains hematopoietic stem cells, but this potential has so far not been studied quantitatively or qualitatively in vitro. To quantity the hematopoietic stem cell potential, we have used highly purified SP/CD45+ cells in long-term culture initiating cell (LTC-IC) assays. The SP/CD45+ cell population purified from murine muscle was found to have significant stem cell activity with an LTC-IC frequency of 1/640. Single-cell-sorted SP/CD45+ cells from muscle exhibited robust proliferative activity in vitro at day 16 (380-fold amplification), especially after culture with OP-9 layers that also support embryonic stem cells. Amplified cell populations originating from single cells exhibited multilineage differentiation ability with evidence of myeloid, lymphoid and NK cell markers. Thus, our results demonstrate that hematopoietic stem cells that can be quantified by LTC-IC assays exist in the murine skeletal muscle and show also for the first time, at the single-cell level, that these cells exhibit multilineage differentiation ability and major proliferative potential.

  5. Human embryonic and fetal mesenchymal stem cells differentiate toward three different cardiac lineages in contrast to their adult counterparts.

    Science.gov (United States)

    Ramkisoensing, Arti A; Pijnappels, Daniël A; Askar, Saïd F A; Passier, Robert; Swildens, Jim; Goumans, Marie José; Schutte, Cindy I; de Vries, Antoine A F; Scherjon, Sicco; Mummery, Christine L; Schalij, Martin J; Atsma, Douwe E

    2011-01-01

    Mesenchymal stem cells (MSCs) show unexplained differences in differentiation potential. In this study, differentiation of human (h) MSCs derived from embryonic, fetal and adult sources toward cardiomyocytes, endothelial and smooth muscle cells was investigated. Labeled hMSCs derived from embryonic stem cells (hESC-MSCs), fetal umbilical cord, bone marrow, amniotic membrane and adult bone marrow and adipose tissue were co-cultured with neonatal rat cardiomyocytes (nrCMCs) or cardiac fibroblasts (nrCFBs) for 10 days, and also cultured under angiogenic conditions. Cardiomyogenesis was assessed by human-specific immunocytological analysis, whole-cell current-clamp recordings, human-specific qRT-PCR and optical mapping. After co-culture with nrCMCs, significantly more hESC-MSCs than fetal hMSCs stained positive for α-actinin, whereas adult hMSCs stained negative. Furthermore, functional cardiomyogenic differentiation, based on action potential recordings, was shown to occur, but not in adult hMSCs. Of all sources, hESC-MSCs expressed most cardiac-specific genes. hESC-MSCs and fetal hMSCs contained significantly higher basal levels of connexin43 than adult hMSCs and co-culture with nrCMCs increased expression. After co-culture with nrCFBs, hESC-MSCs and fetal hMSCs did not express α-actinin and connexin43 expression was decreased. Conduction velocity (CV) in co-cultures of nrCMCs and hESC-MSCs was significantly higher than in co-cultures with fetal or adult hMSCs. In angiogenesis bioassays, only hESC-MSCs and fetal hMSCs were able to form capillary-like structures, which stained for smooth muscle and endothelial cell markers.Human embryonic and fetal MSCs differentiate toward three different cardiac lineages, in contrast to adult MSCs. Cardiomyogenesis is determined by stimuli from the cellular microenvironment, where connexin43 may play an important role.

  6. Endothelial Dysfunction in Renal Failure: Current Update.

    Science.gov (United States)

    Radenkovic, Miroslav; Stojanovic, Marko; Prostran, Milica

    2016-01-01

    Endothelial dysfunction is principally characterized by impaired endothelium- dependent transduction mechanisms related to vascular relaxation, as an outcome of decreased release of endothelium-derived relaxing factors, mainly nitric oxide, as well as augmented oxidative stress, increased inflammation and predominance of vascular action produced by endothelium-derived contracting factors. Current data strongly suggest that pathological development of different types of kidney impairment with further progression to renal failure includes notable vascular changes associated with endothelial dysfunction. In accordance, this scientific field represents an advancing area of investigation, involving different biomarkers of endothelial dysfunction linked to renal impairment, as well as clinical findings with new information that can provide a more comprehensive understanding of the role of endothelial dysfunction in kidney disease. With regards to quoted facts, the aim of this article was to review the latest data related to endothelial dysfunction and renal failure by selection of relevant articles released from 2010 to 2015.

  7. A Bmp Reporter Transgene Mouse Embryonic Stem Cell Model as a Tool to Identify and Characterize Chemical Teratogens.

    Science.gov (United States)

    Kugler, Josephine; Tharmann, Julian; Chuva de Sousa Lopes, Susana M; Kemler, Rolf; Luch, Andreas; Oelgeschläger, Michael

    2015-08-01

    Embryonic stem cells (ESCs) were first isolated from mouse embryos more than 30 years ago. They have proven invaluable not only in generating genetically modified mice that allow for analysis of gene function in tissue development and homeostasis but also as models for genetic disease. In addition, ESCs in vitro are finding inroads in pharmaceutical and toxicological testing, including the identification of teratogenic compounds. Here, we describe the use of a bone morphogenetic protein (Bmp)-reporter ESC line, isolated from a well-characterized transgenic mouse line, as a new tool for the identification of chemical teratogens. The Bmp-mediated expression of the green fluorescent protein enabled the quantification of dose- and time-dependent effects of valproic acid as well as retinoic acid. Significant effects were detectable at concentrations that were comparable to the ones observed in the classical embryonic stem cell test, despite the fact that the reporter gene is expressed in distinct cell types, including endothelial and endodermal cells. Thus these cells provide a valuable new tool for the identification and characterization of relevant mechanisms of embryonic toxicity.

  8. Multilineage differentiation of rhesus monkey embryonic stem cells in three-dimensional culture systems

    Science.gov (United States)

    Chen, Silvia S.; Revoltella, Roberto P.; Papini, Sandra; Michelini, Monica; Fitzgerald, Wendy; Zimmerberg, Joshua; Margolis, Leonid

    2003-01-01

    In the course of normal embryogenesis, embryonic stem (ES) cells differentiate along different lineages in the context of complex three-dimensional (3D) tissue structures. In order to study this phenomenon in vitro under controlled conditions, 3D culture systems are necessary. Here, we studied in vitro differentiation of rhesus monkey ES cells in 3D collagen matrixes (collagen gels and porous collagen sponges). Differentiation of ES cells in these 3D systems was different from that in monolayers. ES cells differentiated in collagen matrixes into neural, epithelial, and endothelial lineages. The abilities of ES cells to form various structures in two chemically similar but topologically different matrixes were different. In particular, in collagen gels ES cells formed gland-like circular structures, whereas in collagen sponges ES cells were scattered through the matrix or formed aggregates. Soluble factors produced by feeder cells or added to the culture medium facilitated ES cell differentiation into particular lineages. Coculture with fibroblasts in collagen gel facilitated ES cell differentiation into cells of a neural lineage expressing nestin, neural cell adhesion molecule, and class III beta-tubulin. In collagen sponges, keratinocytes facilitated ES cell differentiation into cells of an endothelial lineage expressing factor VIII. Exogenous granulocyte-macrophage colony-stimulating factor further enhanced endothelial differentiation. Thus, both soluble factors and the type of extracellular matrix seem to be critical in directing differentiation of ES cells and the formation of tissue-like structures. Three-dimensional culture systems are a valuable tool for studying the mechanisms of these phenomena.

  9. Identification of RSK and TTK as Modulators of Blood Vessel Morphogenesis Using an Embryonic Stem Cell-Based Vascular Differentiation Assay

    Directory of Open Access Journals (Sweden)

    Lamis Hammoud

    2016-10-01

    Full Text Available Blood vessels are formed through vasculogenesis, followed by remodeling of the endothelial network through angiogenesis. Many events that occur during embryonic vascular development are recapitulated during adult neoangiogenesis, which is critical to tumor growth and metastasis. Current antiangiogenic tumor therapies, based largely on targeting the vascular endothelial growth factor pathway, show limited clinical benefits, thus necessitating the discovery of alternative targets. Here we report the development of a robust embryonic stem cell-based vascular differentiation assay amenable to small-molecule screens to identify novel modulators of angiogenesis. In this context, RSK and TTK were identified as angiogenic modulators. Inhibition of these pathways inhibited angiogenesis in embryoid bodies and human umbilical vein endothelial cells. Furthermore, inhibition of RSK and TTK reduced tumor growth, vascular density, and improved survival in an in vivo Lewis lung carcinoma mouse model. Our study suggests that RSK and TTK are potential targets for antiangiogenic therapy, and provides an assay system for further pathway screens.

  10. Synchronization of endothelial Dll4-Notch dynamics switch blood vessels from branching to expansion

    Science.gov (United States)

    Ubezio, Benedetta; Blanco, Raquel Agudo; Geudens, Ilse; Stanchi, Fabio; Mathivet, Thomas; Jones, Martin L; Ragab, Anan; Bentley, Katie; Gerhardt, Holger

    2016-01-01

    Formation of a regularly branched blood vessel network is crucial in development and physiology. Here we show that the expression of the Notch ligand Dll4 fluctuates in individual endothelial cells within sprouting vessels in the mouse retina in vivo and in correlation with dynamic cell movement in mouse embryonic stem cell-derived sprouting assays. We also find that sprout elongation and branching associates with a highly differential phase pattern of Dll4 between endothelial cells. Stimulation with pathologically high levels of Vegf, or overexpression of Dll4, leads to Notch dependent synchronization of Dll4 fluctuations within clusters, both in vitro and in vivo. Our results demonstrate that the Vegf-Dll4/Notch feedback system normally operates to generate heterogeneity between endothelial cells driving branching, whilst synchronization drives vessel expansion. We propose that this sensitive phase transition in the behaviour of the Vegf-Dll4/Notch feedback loop underlies the morphogen function of Vegfa in vascular patterning. DOI: http://dx.doi.org/10.7554/eLife.12167.001 PMID:27074663

  11. [Microglial cells and development of the embryonic central nervous system].

    Science.gov (United States)

    Legendre, Pascal; Le Corronc, Hervé

    2014-02-01

    Microglia cells are the macrophages of the central nervous system with a crucial function in the homeostasis of the adult brain. However, recent studies showed that microglial cells may also have important functions during early embryonic central nervous system development. In this review we summarize recent works on the extra embryonic origin of microglia, their progenitor niche, the pattern of their invasion of the embryonic central nervous system and on interactions between embryonic microglia and their local environment during invasion. We describe microglial functions during development of embryonic neuronal networks, including their roles in neurogenesis, in angiogenesis and developmental cell death. These recent discoveries open a new field of research on the functions of neural-microglial interactions during the development of the embryonic central nervous system.

  12. Rapamycin Inhibits ALDH Activity, Resistance to Oxidative Stress, and Metastatic Potential in Murine Osteosarcoma Cells

    Directory of Open Access Journals (Sweden)

    Xiaodong Mu

    2013-01-01

    Full Text Available Osteosarcoma (OS is the most common primary malignancy of bone. Mortality is determined by the presence of metastatic disease, but little is known regarding the biochemical events that drive metastases. Two murine OS cell lines, K7M2 and K12, are related but differ significantly in their metastatic potentials: K7M2 is highly metastatic whereas K12 displays much less metastatic potential. Using this experimental system, the mammalian target of rapamycin (mTOR pathway has been implicated in OS metastasis. We also discovered that aldehyde dehydrogenase (ALDH, a stem cell marker activity is higher in K7M2 cells than K12 cells. Rapamycin treatment reduces the expression and enzymatic activity of ALDH in K7M2 cells. ALDH inhibition renders these cells more susceptible to apoptotic death when exposed to oxidative stress. Furthermore, rapamycin treatment reduces bone morphogenetic protein-2 (BMP2 and vascular endothelial growth factor (VEGF gene expression and inhibits K7M2 proliferation, migration, and invasion in vitro. Inhibition of ALDH with disulfiram correlated with decreased mTOR expression and activity. In conclusion, we provide evidence for interaction between mTOR activity, ALDH activity, and metastatic potential in murine OS cells. Our work suggests that mTOR and ALDH are therapeutic targets for the treatment and prevention of OS metastasis.

  13. Cross-species transcriptional network analysis defines shared inflammatory responses in murine and human lupus nephritis.

    Science.gov (United States)

    Berthier, Celine C; Bethunaickan, Ramalingam; Gonzalez-Rivera, Tania; Nair, Viji; Ramanujam, Meera; Zhang, Weijia; Bottinger, Erwin P; Segerer, Stephan; Lindenmeyer, Maja; Cohen, Clemens D; Davidson, Anne; Kretzler, Matthias

    2012-07-15

    Lupus nephritis (LN) is a serious manifestation of systemic lupus erythematosus. Therapeutic studies in mouse LN models do not always predict outcomes of human therapeutic trials, raising concerns about the human relevance of these preclinical models. In this study, we used an unbiased transcriptional network approach to define, in molecular terms, similarities and differences among three lupus models and human LN. Genome-wide gene-expression networks were generated using natural language processing and automated promoter analysis and compared across species via suboptimal graph matching. The three murine models and human LN share both common and unique features. The 20 commonly shared network nodes reflect the key pathologic processes of immune cell infiltration/activation, endothelial cell activation/injury, and tissue remodeling/fibrosis, with macrophage/dendritic cell activation as a dominant cross-species shared transcriptional pathway. The unique nodes reflect differences in numbers and types of infiltrating cells and degree of remodeling among the three mouse strains. To define mononuclear phagocyte-derived pathways in human LN, gene sets activated in isolated NZB/W renal mononuclear cells were compared with human LN kidney profiles. A tissue compartment-specific macrophage-activation pattern was seen, with NF-κB1 and PPARγ as major regulatory nodes in the tubulointerstitial and glomerular networks, respectively. Our study defines which pathologic processes in murine models of LN recapitulate the key transcriptional processes active in human LN and suggests that there are functional differences between mononuclear phagocytes infiltrating different renal microenvironments.

  14. Inhibition of endocytosis exacerbates TNF-α-induced endothelial dysfunction via enhanced JNK and p38 activation.

    Science.gov (United States)

    Choi, Hyehun; Nguyen, Hong N; Lamb, Fred S

    2014-04-15

    Tumor necrosis factor-α (TNF-α) is a pro-inflammatory cytokine that causes endothelial dysfunction. Endocytosis of TNF-α receptors (TNFR) precedes endosomal reactive oxygen species (ROS) production, which is required for NF-κB activation in vascular smooth muscle cells. It is unknown how endocytosis of TNFRs impacts signaling in endothelial cells. We hypothesized that TNF-α-induced endothelial dysfunction is induced by both endosomal and cell surface events, including NF-κB and mitogen-activated protein kinases (MAPKs) activation, and endocytosis of the TNFR modifies signaling. Mesenteric artery segments from C57BL/6 mice were treated with TNF-α (10 ng/ml) for 22 h in tissue culture, with or without signaling inhibitors (dynasore for endocytosis, SP600125 for JNK, SB203580 for p38, U0126 for ERK), and vascular function was assessed. Endothelium-dependent relaxation to acetylcholine (ACh) was impaired by TNF-α, and dynasore exacerbated this, whereas JNK or p38 inhibition prevented these effects. In cultured endothelial cells from murine mesenteric arteries, dynasore potentiated JNK and p38 but not ERK phosphorylation and promoted cell death. NF-κB activation by TNF-α was decreased by dynasore. JNK inhibition dramatically increased both the magnitude and duration of TNF-α-induced NF-κB activation and potentiated intercellular adhesion molecule-1 (ICAM-1) activation. Dynasore still inhibited NF-κB activation in the presence of SP600125. Thus TNF-α-induced endothelial dysfunction is both JNK and p38 dependent. Endocytosis modulates the balance of NF-κB and MAPK signaling, and inhibition of NF-κB activation by JNK limits this pro-proliferative signal, which may contribute to endothelial cell death in response to TNF-α.

  15. Selective Deletion of Leptin Signaling in Endothelial Cells Enhances Neointima Formation and Phenocopies the Vascular Effects of Diet-Induced Obesity in Mice.

    Science.gov (United States)

    Hubert, Astrid; Bochenek, Magdalena L; Schütz, Eva; Gogiraju, Rajinikanth; Münzel, Thomas; Schäfer, Katrin

    2017-09-01

    Obesity is associated with elevated circulating leptin levels and hypothalamic leptin resistance. Leptin receptors (LepRs) are expressed on endothelial cells, and leptin promotes neointima formation in a receptor-dependent manner. Our aim was to examine the importance of endothelial LepR (End.LepR) signaling during vascular remodeling and to determine whether the cardiovascular consequences of obesity are because of hyperleptinemia or endothelial leptin resistance. Mice with loxP-flanked LepR alleles were mated with mice expressing Cre recombinase controlled by the inducible endothelial receptor tyrosine kinase promoter. Obesity was induced with high-fat diet. Neointima formation was examined after chemical carotid artery injury. Morphometric quantification revealed significantly greater intimal hyperplasia, neointimal cellularity, and proliferation in End.LepR knockout mice, and similar findings were obtained in obese, hyperleptinemic End.LepR wild-type animals. Analysis of primary endothelial cells confirmed abrogated signal transducer and activator of transcription-3 phosphorylation in response to leptin in LepR knockout and obese LepR wild-type mice. Quantitative PCR, ELISA, and immunofluorescence analyses revealed increased expression and release of endothelin-1 in End.LepR-deficient and LepR-resistant cells, and ET receptor A/B antagonists abrogated their paracrine effects on murine aortic smooth muscle cell proliferation. Reduced expression of peroxisome proliferator-activated receptor-γ and increased nuclear activator protein-1 staining was observed in End.LepR-deficient and LepR-resistant cells, and peroxisome proliferator-activated receptor-γ antagonization increased endothelial endothelin-1 expression. Our findings suggest that intact endothelial leptin signaling limits neointima formation and that obesity represents a state of endothelial leptin resistance. These observations and the identification of endothelin-1 as soluble mediator of the

  16. Tumor necrosis factor-{alpha} enhanced fusions between oral squamous cell carcinoma cells and endothelial cells via VCAM-1/VLA-4 pathway

    Energy Technology Data Exchange (ETDEWEB)

    Song, Kai; Zhu, Fei; Zhang, Han-zhong [The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST), Key Laboratory for Oral Biomedicine Ministry of Education, Wuhan University, Wuhan (China); Shang, Zheng-jun, E-mail: shangzhengjun@hotmail.com [The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST), Key Laboratory for Oral Biomedicine Ministry of Education, Wuhan University, Wuhan (China); First Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Wuhan University, Wuhan (China)

    2012-08-15

    Fusion between cancer cells and host cells, including endothelial cells, may strongly modulate the biological behavior of tumors. However, no one is sure about the driving factors and underlying mechanism involved in such fusion. We hypothesized in this study that inflammation, one of the main characteristics in tumor microenvironment, serves as a prominent catalyst for fusion events. Our results showed that oral cancer cells can fuse spontaneously with endothelial cells in co-culture and inflammatory cytokine tumor necrosis factor-{alpha} (TNF-{alpha}) increased fusion of human umbilical vein endothelium cells and oral cancer cells by up to 3-fold in vitro. Additionally, human oral squamous cell carcinoma cell lines and 35 out of 50 (70%) oral squamous carcinoma specimens express VLA-4, an integrin, previously implicated in fusions between human peripheral blood CD34-positive cells and murine cardiomyocytes. Expression of VCAM-1, a ligand for VLA-4, was evident on vascular endothelium of oral squamous cell carcinoma. Moreover, immunocytochemistry and flow cytometry analysis revealed that expression of VCAM-1 increased obviously in TNF-{alpha}-stimulated endothelial cells. Anti-VLA-4 or anti-VCAM-1 treatment can decrease significantly cancer-endothelial adhesion and block such fusion. Collectively, our results suggested that TNF-{alpha} could enhance cancer-endothelial cell adhesion and fusion through VCAM-1/VLA-4 pathway. This study provides insights into regulatory mechanism of cancer-endothelial cell fusion, and has important implications for the development of novel therapeutic strategies for prevention of metastasis. -- Highlights: Black-Right-Pointing-Pointer Spontaneous oral cancer-endothelial cell fusion. Black-Right-Pointing-Pointer TNF-{alpha} enhanced cell fusions. Black-Right-Pointing-Pointer VCAM-1/VLA-4 expressed in oral cancer. Black-Right-Pointing-Pointer TNF-{alpha} increased expression of VCAM-1 on endothelial cells. Black

  17. Femtosecond laser cutting of endothelial grafts: comparison of endothelial and epithelial applanation.

    Science.gov (United States)

    Bernard, Aurélien; He, Zhiguo; Gauthier, Anne Sophie; Trone, Marie Caroline; Baubeau, Emmanuel; Forest, Fabien; Dumollard, Jean Marc; Peocʼh, Michel; Thuret, Gilles; Gain, Philippe

    2015-02-01

    Stromal surface quality of endothelial lamellae cut for endothelial keratoplasty with a femtosecond laser (FSL) with epithelial applanation remains disappointing. Applanation of the endothelial side of the cornea, mounted inverted on an artificial chamber, has therefore been proposed to improve cut quality. We compared lamellar quality after FSL cutting using epithelial versus endothelial applanation. Lamellae were cut with an FSL from organ-cultured corneas. After randomization, 7 were cut with epithelial applanation and 7 with endothelial applanation. Lamellae of 50-, 75-, and 100-μm thickness were targeted. Thickness was measured by optical coherence tomography before and immediately after cutting. Viable endothelial cell density was quantified immediately after cutting using triple labeling with Hoechst/ethidium/calcein-AM coupled with image analysis with ImageJ. The stromal surface was evaluated by 9 masked observers using semiquantitative scoring of scanning electronic microscopy images. Histology of 2 samples was also analyzed before lamellar detachment. Precision (difference in target/actual thickness) and thickness regularity [coefficient of variation (CV) of 10 measurements] were significantly better with endothelial applanation (precision: 18 μm; range, 10-30; CV: 11%; range, 8-12) than with epithelial applanation (precision: 84 μm; range, 54-107; P = 0.002; CV: 24%; range, 13-47; P = 0.001). Endothelial applanation provided thinner lamellae. However, viable endothelial cell density was significantly lower after endothelial applanation (1183 cells/mm2; range, 787-1725 versus 1688 cells/mm2; range, 1288-2025; P = 0.018). FSL cutting of endothelial lamellae using endothelial applanation provides thinner more regular grafts with more predictable thickness than with conventional epithelial applanation but strongly reduces the pool of viable endothelial cells.

  18. Primary “Botryoid” Embryonal Rhabdomyosarcoma in Mesentery

    Directory of Open Access Journals (Sweden)

    Kiran AGARWAL

    2011-01-01

    Full Text Available Rhabdomyosarcoma is a soft tissue neoplasm arising from primitive embryonal mesenchyma. Embryonal rhabdomyosarcoma mostly affects children younger than 10 years of age, but it also occurs in adolescents and young adults. Pleomorphic rhabdomyosarcoma is a rare variant that almost always arises in adults older than 45 years of age. Mesentery is a rare site for botyroid embryonal rhabdomyosarcoma and on extensive search we found only one case of a botryoid rhabdomyosarcoma in a child of 2 years. We report a rare case of botyroid embryonal rhabdomyosarcoma occurring in the mesentery of a 30 year old female.

  19. Relationship between Intrauterine Bacterial Infection and Early Embryonic Developmental Arrest

    Institute of Scientific and Technical Information of China (English)

    Shao-Fei Yan; Xin-Yan Liu; Yun-Fei Cheng; Zhi-Yi Li; Jie Ou; Wei Wang; Feng-Qin Li

    2016-01-01

    Background:Early embryonic developmental arrest is the most commonly understudied adverse outcome of pregnancy.The relevance of intrauterine infection to spontaneous embryonic death is rarely studied and remains unclear.This study aimed to investigate the relationship between intrauterine bacterial infection and early embryonic developmental arrest.Methods:Embryonic chorion tissue and uterine swabs for bacterial detection were obtained from 33 patients who underwent artificial abortion (control group) and from 45 patients who displayed early embryonic developmental arrest (trial group).Results:Intrauterine bacterial infection was discovered in both groups.The infection rate was 24.44% (11/45) in the early embryonic developmental arrest group and 9.09% (3/33) in the artificial abortion group.Classification analysis revealed that the highest detection rate for Micrococcus luteus in the early embryonic developmental arrest group was 13.33% (6/45),and none was detected in the artificial abortion group.M.luteus infection was significantly different between the groups (P < 0.05 as shown by Fisher's exact test).In addition,no correlation was found between intrauterine bacterial infection and history of early embryonic developmental arrest.Conclusions:M.luteus infection is related to early embryonic developmental arrest and might be one of its causative factors.

  20. Resveratrol and Endothelial Nitric Oxide

    Directory of Open Access Journals (Sweden)

    Ning Xia

    2014-10-01

    Full Text Available Nitric oxide (NO derived from the endothelial NO synthase (eNOS has antihypertensive, antithrombotic, anti-atherosclerotic and antiobesogenic properties. Resveratrol is a polyphenol phytoalexin with multiple cardiovascular and metabolic effects. Part of the beneficial effects of resveratrol are mediated by eNOS. Resveratrol stimulates NO production from eNOS by a number of mechanisms, including upregulation of eNOS expression, stimulation of eNOS enzymatic activity and reversal of eNOS uncoupling. In addition, by reducing oxidative stress, resveratrol prevents oxidative NO inactivation by superoxide thereby enhancing NO bioavailability. Molecular pathways underlying these effects of resveratrol involve SIRT1, AMPK, Nrf2 and estrogen receptors.

  1. Embryonic stem cells in pig and cattle

    DEFF Research Database (Denmark)

    Maddox-Hyttel, Poul; Wolf, Xenia Asbæk; Rasmussen, Mikkel Aabech

    2007-01-01

    transmission in chimaeras has never been obtained. Due to this incomplete characterization of the cell lines, the expression embryonic stem (ES)-like cells is presently used in pig and cattle. The ICM or epiblast can be isolated from the blastocyst by whole blastocyst culture, mechanical isolation...... will be available over the coming years. However, in order to reach this goal further systematic research is needed. Such cell lines hold promises for developing adequate models for human ES cell therapy and they may open for new avenues for the production of genetically modified animals as the ES cells ahve...

  2. Biobanking human embryonic stem cell lines

    DEFF Research Database (Denmark)

    Holm, Søren

    2016-01-01

    Stem cell banks curating and distributing human embryonic stem cells have been established in a number of countries and by a number of private institutions. This paper identifies and critically discusses a number of arguments that are used to justify the importance of such banks in policy...... are curiously absent from the particular stem cell banking policy discourse. This to some extent artificially isolates this discourse from the broader discussions about the flows of reproductive materials and tissues in modern society, and such isolation may lead to the interests of important actors being...

  3. Segmental patterning of the vertebrate embryonic axis.

    Science.gov (United States)

    Dequéant, Mary-Lee; Pourquié, Olivier

    2008-05-01

    The body axis of vertebrates is composed of a serial repetition of similar anatomical modules that are called segments or metameres. This particular mode of organization is especially conspicuous at the level of the periodic arrangement of vertebrae in the spine. The segmental pattern is established during embryogenesis when the somites--the embryonic segments of vertebrates--are rhythmically produced from the paraxial mesoderm. This process involves the segmentation clock, which is a travelling oscillator that interacts with a maturation wave called the wavefront to produce the periodic series of somites. Here, we review our current understanding of the segmentation process in vertebrates.

  4. Embryonic Stem Cell Research: A Policy Analysis.

    Science.gov (United States)

    Warren, Hermine

    Many health care issues generate minimal passion, promoting benign commentary and support from the various stakeholders involved. Stem cell research does not fall into this category, and on the contrary, embryonic stem cell (ESC) research has continued to foster controversy and emotion. Since 1998, which marked the first successful laboratory isolation of ESCs, this research continues to ignite moral, ethical, and legal debate over its efficacy. The focus of this policy analysis is to introduce the issues, examine and address the various perspectives that surround ESC research, and present policy options and/or solutions that may be used to successfully create a policy consensus regarding this much debated topic.

  5. A PROSPECTIVE, OBSERVATIONAL STUDY OF SOLUBLE FLT-1 AND VASCULAR ENDOTHELIAL GROWTH FACTOR IN SEPSIS

    Science.gov (United States)

    Shapiro, Nathan I.; Yano, Kiichiro; Okada, Hitomi; Fischer, Christopher; Howell, Michael; Spokes, Katherine C.; Ngo, Long; Angus, Derek C.; Aird, William C.

    2012-01-01

    Prior murine and human studies suggest that vascular endothelial growth factor (VEGF) contributes to endothelial cell activation and severity of illness in sepsis. Furthermore, circulating levels of soluble VEGF receptor 1 (sFLT) levels were found to increase as part of the early response to sepsis in mice. The objective of the study was to evaluate the blood levels of free VEGF-A and sFLT in patients presenting to the emergency department (ED) with suspected infection and to assess the relationship of these levels with severity of illness and inflammation. It was a prospective, observational study initiated in the ED of an urban, tertiary care, university hospital. Inclusion criteria were (1) ED patients aged 18 years or older and (2) clinical suspicion of infection. Eighty-three patients were enrolled in the study. The major findings were that (1) the mean VEGF and sFLT levels were increasingly higher across the following groups: noninfected control patients, infected patients without shock, and septic shock patients; (2) initial and 24-h VEGF levels had a significant correlation with the presence of septic shock at 24 h; (3) initial and 24-h sFLT levels correlated with Acute Physiology Age Chronic Health Evaluation II and Sepsis-related Organ Failure Assessment scores initially and at 24 h; and (4) VEGF and sFLT levels correlated with inflammatory cascade activation. This is the first report of sFLT as a potential new marker of severity in patients with sepsis. Vascular endothelial cell growth factor and its signaling axis are important in the endothelial cell response to sepsis, and further elucidation of these mechanisms may lead to advances in future diagnostic and therapeutic opportunities. PMID:18598002

  6. Cyclooxygenase-2 inhibition blocks M2 macrophage differentiation and suppresses metastasis in murine breast cancer model.

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    Yi-Rang Na

    Full Text Available Tumor cells are often associated with abundant macrophages that resemble the alternatively activated M2 subset. Tumor-associated macrophages (TAMs inhibit anti-tumor immune responses and promote metastasis. Cyclooxygenase-2 (COX-2 inhibition is known to prevent breast cancer metastasis. This study hypothesized that COX-2 inhibition affects TAM characteristics potentially relevant to tumor cell metastasis. We found that the specific COX-2 inhibitor, etodolac, inhibited human M2 macrophage differentiation, as determined by decreased CD14 and CD163 expressions and increased TNFα production. Several key metastasis-related mediators, such as vascular endothelial growth factor-A, vascular endothelial growth factor-C, and matrix metalloproteinase-9, were inhibited in the presence of etodolac as compared to untreated M2 macrophages. Murine bone marrow derived M2 macrophages also showed enhanced surface MHCII IA/IE and CD80, CD86 expressions together with enhanced TNFα expressions with etodolac treatment during differentiation. Using a BALB/c breast cancer model, we found that etodolac significantly reduced lung metastasis, possibly due to macrophages expressing increased IA/IE and TNFα, but decreased M2 macrophage-related genes expressions (Ym1, TGFβ. In conclusion, COX-2 inhibition caused loss of the M2 macrophage characteristics of TAMs and may assist prevention of breast cancer metastasis.

  7. Physiological hydrostatic pressure protects endothelial monolayer integrity.

    Science.gov (United States)

    Müller-Marschhausen, K; Waschke, J; Drenckhahn, D

    2008-01-01

    Endothelial monolayer integrity is required to maintain endothelial barrier functions and has found to be impaired in several disorders like inflammatory edema, allergic shock, or artherosclerosis. Under physiologic conditions in vivo, endothelial cells are exposed to mechanical forces such as hydrostatic pressure, shear stress, and cyclic stretch. However, insight into the effects of hydrostatic pressure on endothelial cell biology is very limited at present. Therefore, in this study, we tested the hypothesis that physiological hydrostatic pressure protects endothelial monolayer integrity in vitro. We investigated the protective efficacy of hydrostatic pressure in microvascular myocardial endothelial (MyEnd) cells and macrovascular pulmonary artery endothelial cells (PAECs) by the application of selected pharmacological agents known to alter monolayer integrity in the absence or presence of hydrostatic pressure. In both endothelial cell lines, extracellular Ca(2+) depletion by EGTA was followed by a loss of vascular-endothelial cadherin (VE-caherin) immunostaining at cell junctions. However, hydrostatic pressure (15 cmH(2)O) blocked this effect of EGTA. Similarly, cytochalasin D-induced actin depolymerization and intercellular gap formation and cell detachment in response to the Ca(2+)/calmodulin antagonist trifluperazine (TFP) as well as thrombin-induced cell dissociation were also reduced by hydrostatic pressure. Moreover, hydrostatic pressure significantly reduced the loss of VE-cadherin-mediated adhesion in response to EGTA, cytochalasin D, and TFP in MyEnd cells as determined by laser tweezer trapping using VE-cadherin-coated microbeads. In caveolin-1-deficient MyEnd cells, which lack caveolae, hydrostatic pressure did not protect monolayer integrity compromised by EGTA, indicating that caveolae-dependent mechanisms are involved in hydrostatic pressure sensing and signaling.

  8. Role of precoating in artificial vessel endothelialization

    Institute of Scientific and Technical Information of China (English)

    肖乐; 时德

    2004-01-01

    @@ As the progress of vascular surgery, artificial vessels have become the substitute for large and middle diameter vessels but have not for small diameter ones owing to thrombogenesis and occlusion within a short period of time after being applied.Artificial vessel endothelialization is one of the ideal methods to resolve such issue and has been improved continuously since Herring1 in 1978 put forward this term in the first time and utilized vascular endothelial cells (ECs) harvested from living animals to perform the test of artificial vessel endothelialization.

  9. Microvascular endothelial cells of the corpus luteum

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    Spanel-Borowski Katherina

    2003-11-01

    Full Text Available Abstract The cyclic nature of the capillary bed in the corpus luteum offers a unique experimental model to examine the life cycle of endothelial cells, involving discrete physiologically regulated steps of angiogenesis, blood vessel maturation and blood vessel regression. The granulosa cells and theca cells of the developing antral follicle and the steroidogenic cells of the corpus luteum produce and respond to angiogenic factors and vasoactive peptides. Following ovulation the neovascularization during the early stages of corpus luteum development has been compared to the rapid angiogenesis observed during tumor formation. On the other end of the spectrum, the microvascular endothelial cells are the first cells to undergo apoptosis at the onset of corpus luteum regression. Important insights on the morphology and function of luteal endothelial cells have been gained from a combination of in vitro and in vivo studies on endothelial cells. Endothelial cells communicate with cells comprising the functional unit of the corpus luteum, i.e., other vascular cells, steroidogenic cells, and immune cells. This review is designed to provide an overview of the types of endothelial cells present in the corpus luteum and their involvement in corpus luteum development and regression. Available evidence indicates that microvascular endothelial cells of the corpus luteum are not alike, and may differ during the process of angiogenesis and angioregression. The contributions of vasoactive peptides generated by the luteal endothelin-1 and the renin-angiotensin systems are discussed in context with the function of endothelial cells during corpus luteum formation and regression. The ability of two cytokines, tumor necrosis factor alpha and interferon gamma, are evaluated as paracrine mediators of endothelial cell function during angioregression. Finally, chemokines are discussed as a vital endothelial cell secretory products that contribute to the recruitment of

  10. Adenoviral-mediated correction of methylmalonyl-CoA mutase deficiency in murine fibroblasts and human hepatocytes

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    Korson Mark

    2007-04-01

    Full Text Available Abstract Background Methylmalonic acidemia (MMA, a common organic aciduria, is caused by deficiency of the mitochondrial localized, 5'deoxyadenosylcobalamin dependent enzyme, methylmalonyl-CoA mutase (MUT. Liver transplantation in the absence of gross hepatic dysfunction provides supportive therapy and metabolic stability in severely affected patients, which invites the concept of using cell and gene delivery as future treatments for this condition. Methods To assess the effectiveness of gene delivery to restore the defective metabolism in this disorder, adenoviral correction experiments were performed using murine Mut embryonic fibroblasts and primary human methylmalonyl-CoA mutase deficient hepatocytes derived from a patient who harbored two early truncating mutations, E224X and R228X, in the MUT gene. Enzymatic and expression studies were used to assess the extent of functional correction. Results Primary hepatocytes, isolated from the native liver after removal subsequent to a combined liver-kidney transplantation procedure, or Mut murine fibroblasts were infected with a second generation recombinant adenoviral vector that expressed the murine methylmalonyl-CoA mutase as well as eGFP from distinct promoters. After transduction, [1-14C] propionate macromolecular incorporation studies and Western analysis demonstrated complete correction of the enzymatic defect in both cell types. Viral reconstitution of enzymatic expression in the human methylmalonyl-CoA mutase deficient hepatocytes exceeded that seen in fibroblasts or control hepatocytes. Conclusion These experiments provide proof of principle for viral correction in methylmalonic acidemia and suggest that hepatocyte-directed gene delivery will be an effective therapeutic treatment strategy in both murine models and in human patients. Primary hepatocytes from a liver that was unsuitable for transplantation provided an important resource for these studies.

  11. CMTM3 (CKLF-Like Marvel Transmembrane Domain 3) Mediates Angiogenesis by Regulating Cell Surface Availability of VE-Cadherin in Endothelial Adherens Junctions.

    Science.gov (United States)

    Chrifi, Ihsan; Louzao-Martinez, Laura; Brandt, Maarten; van Dijk, Christian G M; Burgisser, Petra; Zhu, Changbin; Kros, Johan M; Duncker, Dirk J; Cheng, Caroline

    2017-06-01

    Decrease in VE-cadherin adherens junctions reduces vascular stability, whereas disruption of adherens junctions is a requirement for neovessel sprouting during angiogenesis. Endocytosis plays a key role in regulating junctional strength by altering bioavailability of cell surface proteins, including VE-cadherin. Identification of new mediators of endothelial endocytosis could enhance our understanding of angiogenesis. Here, we assessed the function of CMTM3 (CKLF-like MARVEL transmembrane domain 3), which we have previously identified as highly expressed in Flk1(+) endothelial progenitor cells during embryonic development. Using a 3-dimensional coculture of human umbilical vein endothelial cells-GFP (green fluorescent protein) and pericytes-RFP (red fluorescent protein), we demonstrated that siRNA-mediated CMTM3 silencing in human umbilical vein endothelial cells impairs angiogenesis. In vivo CMTM3 inhibition by morpholino injection in developing zebrafish larvae confirmed that CMTM3 expression is required for vascular sprouting. CMTM3 knockdown in human umbilical vein endothelial cells does not affect proliferation or migration. Intracellular staining demonstrated that CMTM3 colocalizes with early endosome markers EEA1 (early endosome marker 1) and Clathrin(+) vesicles and with cytosolic VE-cadherin in human umbilical vein endothelial cells. Adenovirus-mediated CMTM3 overexpression enhances endothelial endocytosis, shown by an increase in Clathrin(+), EEA1(+), Rab11(+), Rab5(+), and Rab7(+) vesicles. CMTM3 overexpression enhances, whereas CMTM3 knockdown decreases internalization of cell surface VE-cadherin in vitro. CMTM3 promotes loss of endothelial barrier function in thrombin-induced responses, shown by transendothelial electric resistance measurements in vitro. In this study, we have identified a new regulatory function for CMTM3 in angiogenesis. CMTM3 is involved in VE-cadherin turnover and is a regulator of the cell surface pool of VE-cadherin. Therefore

  12. Chromosomal Aneuploidies and Early Embryonic Developmental Arrest

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    Maria Maurer

    2015-07-01

    Full Text Available Background: Selecting the best embryo for transfer, with the highest chance of achieving a vital pregnancy, is a major goal in current in vitro fertilization (IVF technology. The high rate of embryonic developmental arrest during IVF treatment is one of the limitations in achieving this goal. Chromosomal abnormalities are possibly linked with chromosomal arrest and selection against abnormal fertilization products. The objective of this study was to evaluate the frequency and type of chromosomal abnormalities in preimplantation embryos with developmental arrest. Materials and Methods: This cohort study included blastomeres of embryos with early developmental arrest that were biopsied and analyzed by fluorescence in-situ hybridization (FISH with probes for chromosomes 13, 16, 18, 21 and 22. Forty-five couples undergoing IVF treatment were included, and 119 arrested embryos were biopsied. All probes were obtained from the Kinderwunsch Zentrum, Linz, Austria, between August 2009 and August 2011. Results: Of these embryos, 31.6% were normal for all chromosomes tested, and 68.4% were abnormal. Eleven embryos were uniformly aneuploid, 20 were polyploid, 3 were haploid, 11 displayed mosaicism and 22 embryos exhibited chaotic chromosomal complement. Conclusion: Nearly 70% of arrested embryos exhibit chromosomal errors, making chromosomal abnormalities a major cause of embryonic arrest and may be a further explanation for the high developmental failure rates during culture of the embryos in the IVF setting.

  13. Embryonic stem cells: from markers to market.

    Science.gov (United States)

    Deb, Kaushik Dilip; Jayaprakash, Anitha Devi; Sharma, Vijay; Totey, Satish

    2008-02-01

    ABSTRACT Embryonic stem cells are considered the mother of all kinds of tissues and cells and it is envisioned as the holy grail of regenerative medicine. However, their use in cell replacement therapies (CRT) has so far been limited and their potentials are yet to be fully realized. The use of human embryonic stem cells (hESC) involves many safety issues pertaining to culture conditions and epigenetic changes. The role and importance of an epigenomic signature in derivation and maintenance of hESC are discussed. We provide a list of important epigenetic markers, which should be studied for evaluation of safety in hESC-based cell replacement therapies. These genes also need to be screened to determine an epigenetic signature for pluripotency in the hESCs. Finally a comprehensive list of all known stemness signature genes and the marker genes for different germ line lineages are presented. This review aims at summing up most of the intriguing molecules that can play a role in the maintenance of pluripotency and can help in determining hESC differentiation to various lineages. Extensive understanding of these markers will eventually help the researchers to transform the hESC research from bench to the bedside. The use of hESCs in CRTs is still in its infancy; much effort is warranted to turn them into the much dreamed about magic wand of regenerative medicine.

  14. Dynamics and Mechanics of Zebrafish Embryonic Tissues.

    Science.gov (United States)

    Schoetz, Eva-Maria; Burdine, R. D.; Steinberg, M. S.; Heisenberg, C.-P.; Foty, R. A.; Julicher, F.

    2008-03-01

    In early zebrafish embryonic development, complex flows of cell populations occur, which ultimately lead to the spatial organization of the three germ layers: Ectoderm, mesoderm and endoderm. Here, we study the material properties of these germ layer tissues which are important for their dynamics and spatial organization in the embryo. In general, tissues can be classified as inherently active complex fluids. However, here we present examples of observed tissue behavior, which can be described satisfactorily in terms of passive visco-elastic fluids. We determined the material properties of the germ layer tissues quantitatively and found that differences in their properties influence tissue interaction. Specifically, quantitative differences in tissue surface tension result in tissue immiscibility and cell sorting behavior analogous to that of ordinary immiscible liquids. Surface tensions were measured with a tissue surface tensiometer. Furthermore, by tracking individual cells in the developing zebrafish embryo, we found differences in the migratory behavior of the different tissue types, which are, to some extent, governed by their mechanical properties. Finally, we generated a 3D velocity flow profile describing the tissue movements during zebrafish embryonic organizer development.

  15. Disseminated Cerebrospinal Embryonal Tumor in the Adult

    Science.gov (United States)

    Armocida, Daniele; Caporlingua, Federico; Lapadula, Gennaro; Elefante, Grazia Maria; Antonelli, Manila; Salvati, Maurizio

    2016-01-01

    Introduction. According to the 2016 World Health Organization classification of Tumors of the Central Nervous System, the term Primitive Neuroectodermal Tumor has been replaced by the term Embryonal Tumor (ET). We present a case of disseminated cerebrospinal ET presenting in an adult patient. Illustrative Case. A 49-year-old male presenting with low back pain, dysuria, and hypoesthesia of the lower extremities referred to our emergency department. Brain and whole spine contrast-enhanced MRI documented a diffusively disseminated heterogeneous neoplasm with intradural extra- and intramedullary involvement of the cervicothoracic tract and cauda equina. A primary biopsy of the lumbosacral localization was performed through L5 bilateral laminectomy. Histologic diagnosis was Embryonal Tumor Not Otherwise Specified. The patient underwent chemotherapy with postoperative adjuvant alternating Vincristine-Doxorubicin-Ifosfamide (VAI) and Ifosfamide-Etoposide (IE). Discussion. Spinal ETs are exceedingly rare especially when presenting in the adult patient. Neurosurgical and oncologic management is still unclear. When feasible, surgical removal should always be performed to obtain a histologic diagnosis. Postoperative adjuvant therapy might entail both chemo- and radiotherapy; however a consensus on this matter is still lacking. PMID:27818821

  16. Organotypic slice culture of embryonic brain tissue.

    Science.gov (United States)

    Daza, Ray A M; Englund, Chris; Hevner, Robert F

    2007-12-01

    INTRODUCTIONThis protocol describes how to dissect, assemble, and cultivate mouse embryonic (E) brain tissue from age E11.5 to E18.5 (days) for organotypic slice culture. These preparations can be used for a variety of assays and studies including coculture of different brain regions, cell migration assays, axon guidance assays, and DNA electroporation experiments. During electroporation, an electric current is applied to the surface of a specific target area of the brain slice in order to open holes in the plasma membrane and introduce a plasmid of coding DNA. The floating slice-on-membrane construct helps to preserve the structural integrity of the brain slices, while maintaining easy experimental access and optimal viability. Experiments can be monitored in living slices (e.g., with confocal imaging), and further studies can be completed using slices that have been fixed and cryosectioned at the end of the experiment. Any region of embryonic brain or spinal tissue can be used in this protocol.

  17. Embryonic stem cell differentiation: a chromatin perspective.

    Science.gov (United States)

    Rasmussen, Theodore P

    2003-11-13

    Embryonic stem (ES) cells hold immense promise for the treatment of human degenerative disease. Because ES cells are pluripotent, they can be directed to differentiate into a number of alternative cell-types with potential therapeutic value. Such attempts at "rationally-directed ES cell differentiation" constitute attempts to recapitulate aspects of normal development in vitro. All differentiated cells retain identical DNA content, yet gene expression varies widely from cell-type to cell-type. Therefore, a potent epigenetic system has evolved to coordinate and maintain tissue-specific patterns of gene expression. Recent advances show that mechanisms that govern epigenetic regulation of gene expression are rooted in the details of chromatin dynamics. As embryonic cells differentiate, certain genes are activated while others are silenced. These activation and silencing events are exquisitely coordinated with the allocation of cell lineages. Remodeling of the chromatin of developmentally-regulated genes occurs in conjunction with lineage commitment. Oocytes, early embryos, and ES cells contain potent chromatin-remodeling activities, an observation that suggests that chromatin dynamics may be especially important for early lineage decisions. Chromatin dynamics are also involved in the differentiation of adult stem cells, where the assembly of specialized chromatin upon tissue-specific genes has been studied in fine detail. The next few years will likely yield striking advances in the understanding of stem cell differentiation and developmental biology from the perspective of chromatin dynamics.

  18. Embryonic stem cell differentiation: A chromatin perspective

    Directory of Open Access Journals (Sweden)

    Rasmussen Theodore P

    2003-11-01

    Full Text Available Abstract Embryonic stem (ES cells hold immense promise for the treatment of human degenerative disease. Because ES cells are pluripotent, they can be directed to differentiate into a number of alternative cell-types with potential therapeutic value. Such attempts at "rationally-directed ES cell differentiation" constitute attempts to recapitulate aspects of normal development in vitro. All differentiated cells retain identical DNA content, yet gene expression varies widely from cell-type to cell-type. Therefore, a potent epigenetic system has evolved to coordinate and maintain tissue-specific patterns of gene expression. Recent advances show that mechanisms that govern epigenetic regulation of gene expression are rooted in the details of chromatin dynamics. As embryonic cells differentiate, certain genes are activated while others are silenced. These activation and silencing events are exquisitely coordinated with the allocation of cell lineages. Remodeling of the chromatin of developmentally-regulated genes occurs in conjunction with lineage commitment. Oocytes, early embryos, and ES cells contain potent chromatin-remodeling activities, an observation that suggests that chromatin dynamics may be especially important for early lineage decisions. Chromatin dynamics are also involved in the differentiation of adult stem cells, where the assembly of specialized chromatin upon tissue-specific genes has been studied in fine detail. The next few years will likely yield striking advances in the understanding of stem cell differentiation and developmental biology from the perspective of chromatin dynamics.

  19. Mechanical signaling coordinates the embryonic heart

    Science.gov (United States)

    Chiou, Kevin; Rocks, Jason; Prosser, Benjamin; Discher, Dennis; Liu, Andrea

    The heart is an active material which relies on robust signaling mechanisms between cells in order to produce well-timed, coordinated beats. Heart tissue is composed primarily of active heart muscle cells (cardiomyocytes) embedded in a passive extracellular matrix. During a heartbeat, cardiomyocyte contractions are coordinated across the heart to form a wavefront that propagates through the tissue to pump blood. In the adult heart, this contractile wave is coordinated via intercellular electrical signaling.Here we present theoretical and experimental evidence for mechanical coordination of embryonic heartbeats. We model cardiomyocytes as mechanically excitable Eshelby inclusions embedded in an overdamped elastic-fluid biphasic medium. For physiological parameters, this model replicates recent experimental measurements of the contractile wavefront which are not captured by electrical signaling models. We additionally challenge our model by pharmacologically blocking gap junctions, inhibiting electrical signaling between myocytes. We find that while adult hearts stop beating almost immediately after gap junctions are blocked, embryonic hearts continue beating even at significantly higher concentrations, providing strong support for a mechanical signaling mechanism.

  20. Advances in Murine Models of Diabetic Nephropathy

    Science.gov (United States)

    Kong, Li-li; Wu, Hao; Cui, Wen-peng; Zhou, Wen-hua; Luo, Ping; Sun, Jing; Yuan, Hang; Miao, Li-ning

    2013-01-01

    Diabetic nephropathy (DN) is one of the microvascular complications of both type 1 and type 2 diabetes, which is also associated with a poor life expectancy of diabetic patients. However, the pathogenesis of DN is still unclear. Thus, it is of great use to establish appropriate animal models of DN for doing research on pathogenesis and developing novel therapeutic strategies. Although a large number of murine models of DN including artificially induced, spontaneous, and genetically engineered (knockout and transgenic) animal models have been developed, none of them develops renal changes sufficiently reflecting those seen in humans. Here we review the identified murine models of DN from the aspects of genetic background, type of diabetes, method of induction, gene deficiency, animal age and gender, kidney histopathology, and phenotypic alterations in the hope of enhancing our comprehension of genetic susceptibility and molecular mechanisms responsible for this disease and providing new clues as to how to choose appropriate animal models of DN. PMID:23844375

  1. Murine Typhus: Clinical and epidemiological aspects

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    Gaspar Peniche Lara

    2012-06-01

    Full Text Available Rickettsia typhi is an intracellular bacteria who causes murine typhus. His importance is reflected in the high frequency founding specific antibodies against R. typhi in several worldwide seroepidemiological studies, the seroprevalence ranging between 3-36%. Natural reservoirs of Rickettsia typhi are rats (some species belonging the Rattus Genus and fleas (Xenopsylla cheopis are his vector. This infection is associated with overcrowding, pollution and poor hygiene. Typically presents fever, headache, rash on trunk and extremities, in some cases may occur organ-specific complications, affecting liver, kidney, lung or brain. Initially the disease is very similar to other diseases, is very common to confuse the murine typhus with Dengue fever, therefore, ignorance of the disease is a factor related to complications or non-specific treatments for the resolution of this infection. This paper presents the most relevant information to consider about the rickettsiosis caused by Rickettsia typhi.

  2. Advances in Murine Models of Diabetic Nephropathy

    Directory of Open Access Journals (Sweden)

    Li-li Kong

    2013-01-01

    Full Text Available Diabetic nephropathy (DN is one of the microvascular complications of both type 1 and type 2 diabetes, which is also associated with a poor life expectancy of diabetic patients. However, the pathogenesis of DN is still unclear. Thus, it is of great use to establish appropriate animal models of DN for doing research on pathogenesis and developing novel therapeutic strategies. Although a large number of murine models of DN including artificially induced, spontaneous, and genetically engineered (knockout and transgenic animal models have been developed, none of them develops renal changes sufficiently reflecting those seen in humans. Here we review the identified murine models of DN from the aspects of genetic background, type of diabetes, method of induction, gene deficiency, animal age and gender, kidney histopathology, and phenotypic alterations in the hope of enhancing our comprehension of genetic susceptibility and molecular mechanisms responsible for this disease and providing new clues as to how to choose appropriate animal models of DN.

  3. Immunodetection of Murine Lymphotoxins in Eukaryotic Cells.

    Science.gov (United States)

    Boitchenko, Veronika E.; Korobko, Vyacheslav G.; Prassolov, Vladimir S.; Kravchenko, Vladimir V.; Kuimov, Alexander N.; Turetskaya, Regina L.; Kuprash, Dmitry V.; Nedospasov, Sergei A.

    2000-10-01

    Lymphotoxins alpha and beta (LTalpha and LTbeta) are members of tumor necrosis factor superfamily. LT heterotrimers exist on the surface of lymphocytes and signal through LTbeta receptor while soluble LTalpha homotrimer can signal through TNF receptors p55 and p75. LT-, as well as TNF-mediated signaling are important for the organogenesis and maintenance of microarchitecture of secondary lymphoid organs in mice and has been implicated in the mechanism of certain inflammatory syndromes in humans. In this study we describe the generation of eukaryotic expression plasmids encoding murine LTalpha and LTbeta genes and a prokaryotic expression construct for murine LTalpha. Using recombinant proteins expressed by these vectors as tools for antisera selection, we produced and characterized several polyclonal antibodies capable of detecting LT proteins in eukaryotic cells.

  4. Association of Kidney Tissue Barrier Disrupture and Renal Dysfunction in Resuscitated Murine Septic Shock.

    Science.gov (United States)

    Stenzel, Tatjana; Weidgang, Clair; Wagner, Katja; Wagner, Florian; Gröger, Michael; Weber, Sandra; Stahl, Bettina; Wachter, Ulrich; Vogt, Josef; Calzia, Enrico; Denk, Stephanie; Georgieff, Michael; Huber-Lang, Markus; Radermacher, Peter; McCook, Oscar

    2016-10-01

    Septic shock-related kidney failure is characterized by almost normal morphological appearance upon pathological examination. Endothelial barrier disrupture has been suggested to be of crucial importance for septic shock-induced organ dysfunction. Therefore, in murine resuscitated cecal ligation and puncture (CLP)-induced septic shock, we tested the hypothesis whether there is a direct relationship between the kidney endothelial barrier injury and renal dysfunction. Anesthetized mice underwent CLP, and 15 h later, were anesthetized again and surgically instrumented for a 5-h period of intensive care comprising lung-protective mechanical ventilation, fluid resuscitation, continuous i.v. norepinephrine to maintain target hemodynamics, and measurement of creatinine clearance (CrCl). Animals were stratified according to low or high CrCl. Nitrotyrosine formation, expression of the inducible isoform of the nitric oxide synthase, and blood cytokine (tumor necrosis factor, interleukin-6, interleukin-10) and chemokine (monocyte chemoattractant protein-1, keratinocyte-derived chemokine) levels were significantly higher in animals with low CrCl. When plotted against CrCl and neutrophil gelatinase-associated lipocalin levels, extravascular albumin accumulation, and tissue expression of the vascular endothelial growth factor and angiopoietin-1 showed significant mathematical relationships related to kidney (dys)function. Preservation of the constitutive expression of the hydrogen sulfide producing enzyme cystathione-γ-lyase was associated with maintenance of organ function. The direct quantitative relation between microvascular leakage and kidney (dys)function may provide a missing link between near-normal tissue morphology and septic shock-related renal failure, thus further highlighting the important role of vascular integrity in septic shock-related renal failure.

  5. Amyloid β induces adhesion of erythrocytes to endothelial cells and affects endothelial viability and functionality.

    Science.gov (United States)

    Nakagawa, Kiyotaka; Kiko, Takehiro; Kuriwada, Satoko; Miyazawa, Taiki; Kimura, Fumiko; Miyazawa, Teruo

    2011-01-01

    It has been suggested that amyloid β-peptide (Aβ) might mediate the adhesion of erythrocytes to the endothelium which could disrupt the properties of endothelial cells. We provide evidence here that Aβ actually induced the binding of erythrocytes to endothelial cells and decreased endothelial viability, perhaps by the generation of oxidative and inflammatory stress. These changes are likely to contribute to the pathogenesis of Alzheimer's disease.

  6. Cone inputs to murine striate cortex

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    Gouras Peter

    2008-11-01

    Full Text Available Abstract Background We have recorded responses from single neurons in murine visual cortex to determine the effectiveness of the input from the two murine cone photoreceptor mechanisms and whether there is any unique selectivity for cone inputs at this higher region of the visual system that would support the possibility of colour vision in mice. Each eye was stimulated by diffuse light, either 370 (strong stimulus for the ultra-violet (UV cone opsin or 505 nm (exclusively stimulating the middle wavelength sensitive (M cone opsin, obtained from light emitting diodes (LEDs in the presence of a strong adapting light that suppressed the responses of rods. Results Single cells responded to these diffuse stimuli in all areas of striate cortex. Two types of responsive cells were encountered. One type (135/323 – 42% had little to no spontaneous activity and responded at either the on and/or the off phase of the light stimulus with a few impulses often of relatively large amplitude. A second type (166/323 – 51% had spontaneous activity and responded tonically to light stimuli with impulses often of small amplitude. Most of the cells responded similarly to both spectral stimuli. A few (18/323 – 6% responded strongly or exclusively to one or the other spectral stimulus and rarely in a spectrally opponent manner. Conclusion Most cells in murine striate cortex receive excitatory inputs from both UV- and M-cones. A small fraction shows either strong selectivity for one or the other cone mechanism and occasionally cone opponent responses. Cells that could underlie chromatic contrast detection are present but extremely rare in murine striate cortex.

  7. Murine models of human wound healing.

    Science.gov (United States)

    Chen, Jerry S; Longaker, Michael T; Gurtner, Geoffrey C

    2013-01-01

    In vivo wound healing experiments remain the most predictive models for studying human wound healing, allowing an accurate representation of the complete wound healing environment including various cell types, environmental cues, and paracrine interactions. Small animals are economical, easy to maintain, and allow researchers to take advantage of the numerous transgenic strains that have been developed to investigate the specific mechanisms involved in wound healing and regeneration. Here we describe three reproducible murine wound healing models that recapitulate the human wound healing process.

  8. Stiffness of polyelectrolyte multilayer film influences endothelial function of endothelial cell monolayer.

    Science.gov (United States)

    Chang, Hao; Zhang, He; Hu, Mi; Chen, Jia-Yan; Li, Bo-Chao; Ren, Ke-Feng; Martins, M Cristina L; Barbosa, Mário A; Ji, Jian

    2017-01-01

    Endothelialization has proved to be critical for maintaining long-term success of implantable vascular devices. The formation of monolayer of endothelial cells (ECs) on the implant surfaces is one of the most important factors for the endothelialization. However, endothelial function of regenerated EC monolayer, which plays a much more important role in preventing the complications of post-implantation, has not received enough attention. Here, a vascular endothelial growth factor (VEGF)-incorporated poly(l-lysine)/hyaluronan (PLL/HA) polyelectrolyte multilayer film was fabricated. Through varying the crosslinking degree, stiffness of the film was manipulated, offering either soft or stiff film. We demonstrated that ECs were able to adhere and proliferate on both soft and stiff films, subsequently forming an integrated EC monolayer. Furthermore, endothelial functions were evaluated by characterizing EC monolayer integrity, expression of genes correlated with the endothelial functions, and nitric oxide production. It demonstrated that EC monolayer on the soft film displayed higher endothelial function compared to that on the stiff film. Our study highlights the influence of substrate stiffness on endothelial function, which offers a new criterion for surface design of vascular implants. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Asiaticoside Inhibits TNF-α-Induced Endothelial Hyperpermeability of Human Aortic Endothelial Cells.

    Science.gov (United States)

    Fong, Lai Yen; Ng, Chin Theng; Zakaria, Zainul Amiruddin; Baharuldin, Mohamad Taufik Hidayat; Arifah, Abdul Kadir; Hakim, Muhammad Nazrul; Zuraini, Ahmad

    2015-10-01

    The increase in endothelial permeability often promotes edema formation in various pathological conditions. Tumor necrosis factor-alpha (TNF-α), a pro-atherogenic cytokine, impairs endothelial barrier function and causes endothelial dysfunction in early stage of atherosclerosis. Asiaticoside, one of the triterpenoids derived from Centella asiatica, is known to possess antiinflammatory activity. In order to examine the role of asiaticoside in preserving the endothelial barrier, we assessed its effects on endothelial hyperpermeability and disruption of actin filaments evoked by TNF-α in human aortic endothelial cells (HAEC). TNF-α caused an increase in endothelial permeability to fluorescein isothiocyanate (FITC)-dextran. Asiaticoside pretreatment significantly suppressed TNF-α-induced increased permeability. Asiaticoside also prevented TNF-α-induced actin redistribution by suppressing stress fiber formation. However, the increased F to G actin ratio stimulated by TNF-α was not changed by asiaticoside. Cytochalasin D, an actin depolymerizing agent, was used to correlate the anti-hyperpermeability effect of asiaticoside with actin cytoskeleton. Surprisingly, asiaticoside failed to prevent cytochalasin D-induced increased permeability. These results suggest that asiaticoside protects against the disruption of endothelial barrier and actin rearrangement triggered by TNF-α without a significant change in total actin pool. However, asiaticoside seems to work by other mechanisms to maintain the integrity of endothelial barrier rather than stabilizing the F-actin organization.

  10. Leukocytes Breach Endothelial Barriers by Insertion of Nuclear Lobes and Disassembly of Endothelial Actin Filaments

    Directory of Open Access Journals (Sweden)

    Sagi Barzilai

    2017-01-01

    Full Text Available The endothelial cytoskeleton is a barrier for leukocyte transendothelial migration (TEM. Mononuclear and polymorphonuclear leukocytes generate gaps of similar micron-scale size when squeezing through inflamed endothelial barriers in vitro and in vivo. To elucidate how leukocytes squeeze through these barriers, we co-tracked the endothelial actin filaments and leukocyte nuclei in real time. Nuclear squeezing involved either preexistent or de novo-generated lobes inserted into the leukocyte lamellipodia. Leukocyte nuclei reversibly bent the endothelial actin stress fibers. Surprisingly, formation of both paracellular gaps and transcellular pores by squeezing leukocytes did not require Rho kinase or myosin II-mediated endothelial contractility. Electron-microscopic analysis suggested that nuclear squeezing displaced without condensing the endothelial actin filaments. Blocking endothelial actin turnover abolished leukocyte nuclear squeezing, whereas increasing actin filament density did not. We propose that leukocyte nuclei must disassemble the thin endothelial actin filaments interlaced between endothelial stress fibers in order to complete TEM.

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  5. Endothelial progenitor cells in cardiovascular diseases

    Institute of Scientific and Technical Information of China (English)

    Poay; Sian; Sabrina; Lee; Kian; Keong; Poh

    2014-01-01

    Endothelial dysfunction has been associated with the development of atherosclerosis and cardiovascular diseases. Adult endothelial progenitor cells(EPCs) are derived from hematopoietic stem cells and are capable of forming new blood vessels through a process of vas-culogenesis. There are studies which report correlations between circulating EPCs and cardiovascular risk fac-tors. There are also studies on how pharmacotherapies may influence levels of circulating EPCs. In this review, we discuss the potential role of endothelial progenitor cells as both diagnostic and prognostic biomarkers. In addition, we look at the interaction between cardio-vascular pharmacotherapies and endothelial progenitor cells. We also discuss how EPCs can be used directly and indirectly as a therapeutic agent. Finally, we evalu-ate the challenges facing EPC research and how these may be overcome.

  6. Spontaneous cyclic embryonic movements in humans and guinea pigs

    NARCIS (Netherlands)

    Felt, Renee H. M.; Mulder, Eduard J. H.; Luchinger, Annemarie B.; van Kan, Colette M.; Taverne, Marcel A. M.; de Vries, J. I. P.

    2012-01-01

    Motility assessment before birth can be used to evaluate the integrity of the nervous system. Sideways bending (SB) of head and/or rump, the earliest embryonic motility in both humans and guinea pigs, can be visualized sonographically. We know from other species that early embryonic motility is cycl

  7. Influx mechanisms in the embryonic and adult rat choroid plexus

    DEFF Research Database (Denmark)

    Saunders, Norman R; Dziegielewska, Katarzyna M; Møllgård, Kjeld

    2015-01-01

    The transcriptome of embryonic and adult rat lateral ventricular choroid plexus, using a combination of RNA-Sequencing and microarray data, was analyzed by functional groups of influx transporters, particularly solute carrier (SLC) transporters. RNA-Seq was performed at embryonic day (E) 15 and a...

  8. Sox2 in Embryonic Stem Cells and Lung Development

    NARCIS (Netherlands)

    C.G. Pardo (Cristina Gontan)

    2009-01-01

    markdownabstract__Abstract__ Sox2 is a fascinating transcription factor with multiple roles during embryonic development. In early embryonic development, Sox2 is one of the key transcription factors in the maintenance of the pluripotent status of the cells of the inner cell mass (ICM). Sox2 is also

  9. Pathways in pluripotency and differentiation of embryonic cells

    NARCIS (Netherlands)

    du Puy, L.

    2010-01-01

    Pluripotency - the potential to differentiate into derivatives of the three embryonic germ layers endoderm, ectoderm and mesoderm - is the main characteristic of embryonic stem (ES) cells. ES cells are derived from the inner cell mass (ICM) of a pre-implantation blastocyst and can self-renew

  10. The mechanical consequences of mineralization in embryonic bone.

    NARCIS (Netherlands)

    Tanck, E.J.M.; Donkelaar, C.C. van; Jepsen, K.J.; Goldstein, S.A.; Weinans, H.; Burger, E.H.; Huiskes, R.

    2004-01-01

    The purpose of this study was to examine the effect of mineralization on the mechanical properties of embryonic bone rudiments. For this purpose, four-point bending experiments were performed on unmineralized and mineralized embryonic mouse ribs at 16 and 17 days of gestational age. Young's modulus

  11. Pathways in pluripotency and differentiation of embryonic cells

    NARCIS (Netherlands)

    du Puy, L.

    2010-01-01

    Pluripotency - the potential to differentiate into derivatives of the three embryonic germ layers endoderm, ectoderm and mesoderm - is the main characteristic of embryonic stem (ES) cells. ES cells are derived from the inner cell mass (ICM) of a pre-implantation blastocyst and can self-renew indefin

  12. Meeting embryonic requirements of broilers throughout incubation: a review

    NARCIS (Netherlands)

    Molenaar, R.; Reijrink, I.A.M.; Meijerhof, R.; Brand, van den H.

    2010-01-01

    During incubation of chicken embryos, environmental conditions, such as temperature, relative humidity, and CO2 concentration, must be controlled to meet embryonic requirements that change during the different phases of embryonic development. In the current review, the effects of embryo temperature,

  13. A New Model to Perform Electrophysiological Studies in the Early Embryonic Mouse Heart

    Directory of Open Access Journals (Sweden)

    Anna Kornblum

    2013-07-01

    Full Text Available Background: The first electrocardiograms (ECGs have been recorded with a capillary electrometer in the late 19th century by John Burdon Sanderson and Augustus Waller. In 1903 Willem Einthoven used the much more sensitive string galvanometer and was awarded Nobel Price in Medicine for this discovery. Though the physical principles of that era are still in use, there have been many advances but also challenges in cardiac electrophysiology over the last decades. One challenge is to record electrocardiograms of rather small animals such as mice and even smaller organisms such as their embryos. As mice belong to the most routinely used laboratory animals it is important to better understand their physiology and specific diseases. We therefore aimed to study whether it is feasible to measure electrical activities of embryonic mouse hearts. Methods and Results: For our studies we used substrate-integrated Microelectrode Arrays combined with newly developed stimulation electrodes to perform electrophysiological studies in these hearts. The system enabled us to perform ECG-like recordings with atrio-ventricular (anterograde and ventriculo-atrial (retrograde stimulation. The functional separation of atria and ventricles, indicated by a stable atrio-ventricular conduction time, occurred clearly earlier than the morphological separation. Electrical stimulation induced a reversible prolongation of the anterograde and retrograde conduction up to atrio-ventricular conduction blocks at higher frequencies. Conclusion: These results yield new insight into functional aspects of murine cardiac development, and may help as a new diagnostic tool to uncover the functional and electrophysiological background of embryonic cardiac phenotypes of genetically altered mice.

  14. Reproducible culture and differentiation of mouse embryonic stem cells using an automated microwell platform.

    Science.gov (United States)

    Hussain, Waqar; Moens, Nathalie; Veraitch, Farlan S; Hernandez, Diana; Mason, Chris; Lye, Gary J

    2013-08-15

    The use of embryonic stem cells (ESCs) and their progeny in high throughput drug discovery and regenerative medicine will require production at scale of well characterized cells at an appropriate level of purity. The adoption of automated bioprocessing techniques offers the possibility to overcome the lack of consistency and high failure rates seen with current manual protocols. To build the case for increased use of automation this work addresses the key question: "can an automated system match the quality of a highly skilled and experienced person working manually?" To answer this we first describe an integrated automation platform designed for the 'hands-free' culture and differentiation of ESCs in microwell formats. Next we outline a framework for the systematic investigation and optimization of key bioprocess variables for the rapid establishment of validatable Standard Operating Procedures (SOPs). Finally the experimental comparison between manual and automated bioprocessing is exemplified by expansion of the murine Oct-4-GiP ESC line over eight sequential passages with their subsequent directed differentiation into neural precursors. Our results show that ESCs can be effectively maintained and differentiated in a highly reproducible manner by the automated system described. Statistical analysis of the results for cell growth over single and multiple passages shows up to a 3-fold improvement in the consistency of cell growth kinetics with automated passaging. The quality of the cells produced was evaluated using a panel of biological markers including cell growth rate and viability, nutrient and metabolite profiles, changes in gene expression and immunocytochemistry. Automated processing of the ESCs had no measurable negative effect on either their pluripotency or their ability to differentiate into the three embryonic germ layers. Equally important is that over a 6-month period of culture without antibiotics in the medium, we have not had any cases of

  15. Effects of oxaliplatin and oleic acid Gc-protein-derived macrophage-activating factor on murine and human microglia.

    Science.gov (United States)

    Branca, Jacopo J V; Morucci, Gabriele; Malentacchi, Francesca; Gelmini, Stefania; Ruggiero, Marco; Pacini, Stefania

    2015-09-01

    The biological properties and characteristics of microglia in rodents have been widely described, but little is known about these features in human microglia. Several murine microglial cell lines are used to investigate neurodegenerative and neuroinflammatory conditions; however, the extrapolation of the results to human conditions is frequently met with criticism because of the possibility of species-specific differences. This study compares the effects of oxaliplatin and of oleic acid Gc-protein-derived macrophage-activating factor (OA-GcMAF) on two microglial cell lines, murine BV-2 cells and human C13NJ cells. Cell viability, cAMP levels, microglial activation, and vascular endothelial growth factor (VEGF) expression were evaluated. Our data demonstrate that oxaliplatin induced a significant decrease in cell viability in BV-2 and in C13NJ cells and that this effect was not reversed with OA-GcMAF treatment. The signal transduction pathway involving cAMP/VEGF was activated after treatment with oxaliplatin and/or OA-GcMAF in both cell lines. OA-GcMAF induced a significant increase in microglia activation, as evidenced by the expression of the B7-2 protein, in BV-2 as well as in C13NJ cells that was not associated with a concomitant increase in cell number. Furthermore, the effects of oxaliplatin and OA-GcMAF on coculture morphology and apoptosis were evaluated. Oxaliplatin-induced cell damage and apoptosis were nearly completely reversed by OA-GcMAF treatment in both BV-2/SH-SY5Y and C13NJ/SH-SY5Y cocultures. Our data show that murine and human microglia share common signal transduction pathways and activation mechanisms, suggesting that the murine BV-2 cell line may represent an excellent model for studying human microglia.

  16. [Endothelial dysfunction in pathogenesis of duodenal ulcer].

    Science.gov (United States)

    Oparin, A G; Oparin, A A

    2002-01-01

    It is shown that in patients with ulcer associated with Helicobacter pylori (HP) there is a close correlation between the severity of the lesion of gastroduodenal protective mucous barrier and that of endothelial dysfunction manifesting in elevated level of endothelin-1, serum levels of TBK-active products, inhibition of blood flow and narrowing of the celiac trunk. The correlation becomes stronger with expanding contamination of gastroduodenal mucosa with HP. Thus, HP may participate in breaking the protective mucous barrier in endothelial dysfunction.

  17. Normal corneal endothelial cell density in Nigerians

    Directory of Open Access Journals (Sweden)

    Ewete T

    2016-03-01

    Full Text Available Temitope Ewete,1 Efeoghene Uchenna Ani,2 Adegboyega Sunday Alabi1 1MeCure Eye Center, Lagos, 2Department of Ophthalmology, University of Port Harcourt, Port Harcourt, Nigeria Aim: The aim of the study was to describe the corneal endothelial cell density of adults at the MeCure Eye Center and to determine the relationship between age, sex, and corneal endothelial cell density. Methods: This study was a retrospective study looking at those records of individuals who had undergone specular microscopy or corneal endothelial cell count measurement at the MeCure Eye Center. Results: The endothelial cell characteristics of 359 healthy eyes of 201 volunteers were studied. The mean corneal endothelial cell density (MCD was 2,610.26±371.87 cells/mm2 (range, 1,484–3,571 cells/mm2. The MCD decreased from 2,860.70 cells/mm2 in the 20–30-year age group to 2,493.06 cells/mm2 in the >70-year age group, and there was a statistically significant relationship between age and MCD with a P-value of <0.001. There was no statistically significant correlation between sex and corneal endothelial cell density (P=0.45. Conclusion: This study shows that endothelial cell density in Nigerian eyes is less than that reported in the Japanese, American, and Chinese eyes, and is comparable to that seen in Indian and Malaysian eyes. Keywords: corneal, endothelial cell density, Nigerian

  18. Endothelial dysfunction and inflammation in asymptomatic proteinuria

    OpenAIRE

    Paisley, K.E.; Beaman, M; Tooke, J. E.; Mohamed-Ali, V; Lowe, G. D. O.; Shore, A C

    2003-01-01

    Background. Proteinuria is associated with vascular risk and a systemic increase in vascular permeability. Endothelial dysfunction occurs early in atherosclerosis and modulates vascular permeability. Vascular risk and chronic inflammation are associated. This study investigates whether the increased vascular permeability in proteinuria reflects systemic endothelial dysfunction and chronic inflammation. Methods. Twenty-one patients with asymptomatic proteinuria (1.29 g/24 h; range 0.18 to 3.17...

  19. Mesenchymal stem cells exhibit firm adhesion, crawling, spreading and transmigration across aortic endothelial cells: effects of chemokines and shear.

    Directory of Open Access Journals (Sweden)

    Giselle Chamberlain

    Full Text Available Mesenchymal stem cells (MSCs have anti-inflammatory and immunosuppressive properties and may be useful in the therapy of diseases such as arteriosclerosis. MSCs have some ability to traffic into inflamed tissues, however to exploit this therapeutically their migratory mechanisms need to be elucidated. This study examines the interaction of murine MSCs (mMSCs with, and their migration across, murine aortic endothelial cells (MAECs, and the effects of chemokines and shear stress. The interaction of mMSCs with MAECs was examined under physiological flow conditions. mMSCs showed lack of interaction with MAECs under continuous flow. However, when the flow was stopped (for 10 min and then started, mMSCs adhered and crawled on the endothelial surface, extending fine microvillous processes (filopodia. They then spread extending pseudopodia in multiple directions. CXCL9 significantly enhanced the percentage of mMSCs adhering, crawling and spreading and shear forces markedly stimulated crawling and spreading. CXCL9, CXCL16, CCL20 and CCL25 significantly enhanced transendothelial migration across MAECs. The transmigrated mMSCs had down-regulated receptors CXCR3, CXCR6, CCR6 and CCR9. This study furthers the knowledge of MSC transendothelial migration and the effects of chemokines and shear stress which is of relevance to inflammatory diseases such as arteriosclerosis.

  20. 4D embryonic cardiography using gated optical coherence tomography

    Science.gov (United States)

    Jenkins, M. W.; Rothenberg, F.; Roy, D.; Nikolski, V. P.; Hu, Z.; Watanabe, M.; Wilson, D. L.; Efimov, I. R.; Rollins, A. M.

    2006-01-01

    Simultaneous imaging of very early embryonic heart structure and function has technical limitations of spatial and temporal resolution. We have developed a gated technique using optical coherence tomography (OCT) that can rapidly image beating embryonic hearts in four-dimensions (4D), at high spatial resolution (10-15 μm), and with a depth penetration of 1.5 - 2.0 mm that is suitable for the study of early embryonic hearts. We acquired data from paced, excised, embryonic chicken and mouse hearts using gated sampling and employed image processing techniques to visualize the hearts in 4D and measure physiologic parameters such as cardiac volume, ejection fraction, and wall thickness. This technique is being developed to longitudinally investigate the physiology of intact embryonic hearts and events that lead to congenital heart defects.

  1. Human embryonic stem cell lines derived from the Chinese population

    Institute of Scientific and Technical Information of China (English)

    Zhen Fu FANG; Fan JIN; Hui GAI; Ying CHEN; Li WU; Ai Lian LIU; Bin CHEN; Hui Zhen SHENG

    2005-01-01

    Six human embryonic stem cell lines were established from surplus blastocysts. The cell lines expressed alkaline phosphatase and molecules typical of primate embryonic stem cells, including Oct-4, Nanog, TDGF1, Sox2, EBAF,Thy-1, FGF4, Rex-1, SSEA-3, SSEA-4, TRA-1-60 and TRA-1-81. Five of the six lines formed embryoid bodies that expressed markers of a variety of cell types; four of them formed teratomas with tissue types representative of all three embryonic germ layers. These human embryonic stem cells are capable of producing clones of undifferentiated morphology, and one of them was propagated to become a subline. Human embryonic stem cell lines from the Chinese population should facilitate stem cell research and may be valuable in studies of population genetics and ecology.

  2. Ultrasound assessment of endothelial function in children

    Directory of Open Access Journals (Sweden)

    Mikko J Järvisalo

    2005-10-01

    Full Text Available Mikko J Järvisalo1,2, Olli T Raitakari21Department of Internal Medicine, Satakunta Central Hospital, Pori, Finland; 2Department of Clinical Physiology, Turku University Hospital, Turku, FinlandAbstract: Although the clinical complications of atherosclerosis arise from developed lesions in old age, the atherosclerotic disease is a lifelong process with roots in childhood. Endothelial dysfunction is currently considered an early stage in the pathogenesis of atherosclerosis, which precedes the formation of structural atherosclerotic changes. Improvements in noninvasive imaging modalities, mainly in ultrasound imaging, have made it possible to assess the endothelial health of asymptomatic children with or without cardiovascular risk factors. By using noninvasive ultrasound for endothelial function, important insights have been gained into the early stages of atherosclerosis and the effects of cardiovascular risk factors on vasculature in childhood. The ultrasound test of endothelial function is affordable, available, and safe and may be considered a potent aid in clinical risk stratification of children at high risk for subsequent clinical atherosclerosis in adulthood. At present, this methodology serves only research purposes, as many issues including reproducibility and normal values for healthy children need to be solved before clinical use can be considered. In adults, however, recent studies have shown that attenuated endothelial function predicts the occurrence of future cardiovascular events.Keywords: atherosclerosis, endothelial dysfunction, ultrasound imaging, childhood vasculature

  3. Endothelial Dysfunction in Chronic Inflammatory Diseases

    Directory of Open Access Journals (Sweden)

    Curtis M. Steyers

    2014-06-01

    Full Text Available Chronic inflammatory diseases are associated with accelerated atherosclerosis and increased risk of cardiovascular diseases (CVD. As the pathogenesis of atherosclerosis is increasingly recognized as an inflammatory process, similarities between atherosclerosis and systemic inflammatory diseases such as rheumatoid arthritis, inflammatory bowel diseases, lupus, psoriasis, spondyloarthritis and others have become a topic of interest. Endothelial dysfunction represents a key step in the initiation and maintenance of atherosclerosis and may serve as a marker for future risk of cardiovascular events. Patients with chronic inflammatory diseases manifest endothelial dysfunction, often early in the course of the disease. Therefore, mechanisms linking systemic inflammatory diseases and atherosclerosis may be best understood at the level of the endothelium. Multiple factors, including circulating inflammatory cytokines, TNF-α (tumor necrosis factor-α, reactive oxygen species, oxidized LDL (low density lipoprotein, autoantibodies and traditional risk factors directly and indirectly activate endothelial cells, leading to impaired vascular relaxation, increased leukocyte adhesion, increased endothelial permeability and generation of a pro-thrombotic state. Pharmacologic agents directed against TNF-α-mediated inflammation may decrease the risk of endothelial dysfunction and cardiovascular disease in these patients. Understanding the precise mechanisms driving endothelial dysfunction in patients with systemic inflammatory diseases may help elucidate the pathogenesis of atherosclerosis in the general population.

  4. Tumor and endothelial cell-derived microvesicles carry distinct CEACAMs and influence T-cell behavior.

    Directory of Open Access Journals (Sweden)

    Harrison T Muturi

    Full Text Available Normal and malignant cells release a variety of different vesicles into their extracellular environment. The most prominent vesicles are the microvesicles (MVs, 100-1000 nm in diameter, which are shed of the plasma membrane, and the exosomes (70-120 nm in diameter, derivates of the endosomal system. MVs have been associated with intercellular communication processes and transport numerous proteins, lipids and RNAs. As essential component of immune-escape mechanisms tumor-derived MVs suppress immune responses. Additionally, tumor-derived MVs have been found to promote metastasis, tumor-stroma interactions and angiogenesis. Since members of the carcinoembryonic antigen related cell adhesion molecule (CEACAM-family have been associated with similar processes, we studied the distribution and function of CEACAMs in MV fractions of different human epithelial tumor cells and of human and murine endothelial cells. Here we demonstrate that in association to their cell surface phenotype, MVs released from different human epithelial tumor cells contain CEACAM1, CEACAM5 and CEACAM6, while human and murine endothelial cells were positive for CEACAM1 only. Furthermore, MVs derived from CEACAM1 transfected CHO cells carried CEACAM1. In terms of their secretion kinetics, we show that MVs are permanently released in low doses, which are extensively increased upon cellular starvation stress. Although CEACAM1 did not transmit signals into MVs it served as ligand for CEACAM expressing cell types. We gained evidence that CEACAM1-positive MVs significantly increase the CD3 and CD3/CD28-induced T-cell proliferation. All together, our data demonstrate that MV-bound forms of CEACAMs play important roles in intercellular communication processes, which can modulate immune response, tumor progression, metastasis and angiogenesis.

  5. Microvesicles Derived from Indoxyl Sulfate Treated Endothelial Cells Induce Endothelial Progenitor Cells Dysfunction.

    Science.gov (United States)

    Carmona, Andres; Guerrero, Fatima; Buendia, Paula; Obrero, Teresa; Aljama, Pedro; Carracedo, Julia

    2017-01-01

    Cardiovascular disease is a major cause of mortality in chronic kidney disease patients. Indoxyl sulfate (IS) is a typical protein-bound uremic toxin that cannot be effectively cleared by conventional dialysis. Increased IS is associated with the progression of chronic kidney disease and development of cardiovascular disease. After endothelial activation by IS, cells release endothelial microvesicles (EMV) that can induce endothelial dysfunction. We developed an in vitro model of endothelial damage mediated by IS to evaluate the functional effect of EMV on the endothelial repair process developed by endothelial progenitor cells (EPCs). EMV derived from IS-treated endothelial cells were isolated by ultracentrifugation and characterized for miRNAs content. The effects of EMV on healthy EPCs in culture were studied. We observed that IS activates endothelial cells and the generated microvesicles (IsEMV) can modulate the classic endothelial roles of progenitor cells as colony forming units and form new vessels in vitro. Moreover, 23 miRNAs were contained in IsEMV including four (miR-181a-5p, miR-4454, miR-150-5p, and hsa-let-7i-5p) that were upregulated in IsEMV compared with control endothelial microvesicles. Other authors have found that miR-181a-5p, miR-4454, and miR-150-5p are involved in promoting inflammation, apoptosis, and cellular senescence. Interestingly, we observed an increase in NFκB and p53, and a decrease in IκBα in EPCs treated with IsEMV. Our data suggest that IS is capable of inducing endothelial vesiculation with different membrane characteristics, miRNAs and other molecules, which makes maintaining of vascular homeostasis of EPCs not fully functional. These specific characteristics of EMV could be used as novel biomarkers for diagnosis and prognosis of vascular disease.

  6. Current progress with primate embryonic stem cells.

    Science.gov (United States)

    Byrne, James A; Mitalipov, Shoukhrat M; Wolf, Don P

    2006-05-01

    Embryonic stem cells (ESCs) can proliferate indefinitely, maintain an undifferentiated pluripotent state and differentiate into any cell type. Differentiation of ESCs into various specific cell-types may be able to cure or alleviate the symptoms of various degenerative diseases. Unresolved issues regarding maintaining function, possible apoptosis and tumor formation in vivo mean a prudent approach should be taken towards advancing ESCs into human clinical trials. Rhesus macaques provide the ideal model organism for testing the feasibility, efficacy and safety of ESC based therapies and significant numbers of primate ESC lines are now available. In this review, we will summarize progress in evaluating the genetic and epigenetic integrity of primate ESCs, examine their current use in pre-clinical trials and discuss the potential of producing ESC-derived cell populations that are genetically identical (isogenic) to the host by somatic cell nuclear transfer.

  7. Human embryonic stem cells and patent protection

    Directory of Open Access Journals (Sweden)

    Radovanović Sanja M.

    2015-01-01

    Full Text Available Given the importance of biotechnological research in modern diagnostics and therapeutics, on the one hand, and stimulative function of a patent, on the other hand, this work deals with the question of the possibility of pa-tent protection of human embryonic stem cells. Taking into account that this is a biotechnological invention, the key question that this paper highlights is the interpretation of the provisions of their patentability. Namely, thanks to the advanced methods of isolation, purification and preparation for implementation, modern patent systems do not exclude a priori living organisms from patent protection. Therefore, the analysis of representative administrative decisions or court rulings sought to define the criteria that would be applied in order to give patent protection to a certain biotechnological invention (stem cells while others do not.

  8. Human embryonic stem cells: preclinical perspectives

    Directory of Open Access Journals (Sweden)

    Sarda Kanchan

    2008-01-01

    Full Text Available Abstract Human embryonic stem cells (hESCs have been extensively discussed in public and scientific communities for their potential in treating diseases and injuries. However, not much has been achieved in turning them into safe therapeutic agents. The hurdles in transforming hESCs to therapies start right with the way these cells are derived and maintained in the laboratory, and goes up-to clinical complications related to need for patient specific cell lines, gender specific aspects, age of the cells, and several post transplantation uncertainties. The different types of cells derived through directed differentiation of hESC and used successfully in animal disease and injury models are described briefly. This review gives a brief outlook on the present and the future of hESC based therapies, and talks about the technological advances required for a safe transition from laboratory to clinic.

  9. Human embryonic stem cells for neuronal repair.

    Science.gov (United States)

    Ben-Hur, Tamir

    2006-02-01

    Human embryonic stem cells may serve as a potentially endeless source of transplantable cells to treat various neurologic disorders. Accumulating data have shown the therapeutic value of various neural precursor cell types in experimental models of neurologic diseases. Tailoring cell therapy for specific disorders requires the generation of cells that are committed to specific neural lineages. To this end, protocols were recently developed for the derivation of dopaminergic neurons, spinal motor neurons and oligodendrocytes from hESC. These protocols recapitulate normal development in culture conditions. However, a novel concept emerging from these studies is that the beneficial effect of transplanted stem cells is not only via cell replacement in damaged host tissue, but also by trophic and protective effects, as well as by an immunomodulatory effect that down-regulates detrimental brain inflammation.

  10. Constitutive knockout of Surf1 is associated with high embryonic lethality, mitochondrial disease and cytochrome c oxidase deficiency in mice.

    Science.gov (United States)

    Agostino, Alessandro; Invernizzi, Federica; Tiveron, Cecilia; Fagiolari, Gigliola; Prelle, Alessandro; Lamantea, Eleonora; Giavazzi, Alessio; Battaglia, Giorgio; Tatangelo, Laura; Tiranti, Valeria; Zeviani, Massimo

    2003-02-15

    We report here the creation of a constitutive knockout mouse for SURF1, a gene encoding one of the assembly proteins involved in the formation of cytochrome c oxidase (COX). Loss-of-function mutations of SURF1 cause Leigh syndrome associated with an isolated and generalized COX deficiency in humans. The murine phenotype is characterized by the following hallmarks: (1) high post-implantation embryonic lethality, affecting approximately 90% of the Surf1(-/-) individuals; (2) early-onset mortality of post-natal individuals; (3) highly significant deficit in muscle strength and motor performance; (4) profound and isolated defect of COX activity in skeletal muscle and liver, and, to a lesser extent, heart and brain; (5) morphological abnormalities of skeletal muscle, characterized by reduced histochemical reaction to COX and mitochondrial proliferation; (6) no obvious abnormalities in brain morphology, reflecting the virtual absence of overt neurological symptoms. These results indicate a function for murine Surf1 protein (Surf1p) specifically related to COX and recapitulate, at least in part, the human phenotype. This is the first mammalian model for a nuclear disease gene of a human mitochondrial disorder. Our model constitutes a useful tool to investigate the function of Surf1p, help understand the pathogenesis of Surf1p deficiency in vivo, and evaluate the efficacy of treatment.

  11. Functional analysis of Scr during embryonic and post-embryonic development in the cockroach, Periplaneta americana.

    Science.gov (United States)

    Hrycaj, Steven; Chesebro, John; Popadić, Aleksandar

    2010-05-01

    The cockroach, Periplaneta americana represents a basal insect lineage that undergoes the ancestral hemimetabolous mode of development. Here, we examine the embryonic and post-embryonic functions of the hox gene Scr in Periplaneta as a way of better understanding the roles of this gene in the evolution of insect body plans. During embryogenesis, Scr function is strictly limited to the head with no role in the prothorax. This indicates that the ancestral embryonic function of Scr was likely restricted to the head, and that the posterior expansion of expression in the T1 legs may have preceded any apparent gain of function during evolution. In addition, Scr plays a pivotal role in the formation of the dorsal ridge, a structure that separates the head and thorax in all insects. This is evidenced by the presence of a supernumerary segment that occurs between the labial and T1 segments of RNAiScr first nymphs and is attributed to an alteration in engrailed (en) expression. The fact that similar Scr phenotypes are observed in Tribolium but not in Drosophila or Oncopeltus reveals the presence of lineage-specific variation in the genetic architecture that controls the formation of the dorsal ridge. In direct contrast to the embryonic roles, Scr has no function in the head region during post-embryogenesis in Periplaneta, and instead, strictly acts to provide identity to the T1 segment. Furthermore, the strongest Periplaneta RNAiScr phenotypes develop ectopic wing-like tissue that originates from the posterior region of the prothoracic segment. This finding provides a novel insight into the current debate on the morphological origin of insect wings.

  12. Integrative analysis of the mouse embryonic transcriptome.

    Science.gov (United States)

    Singh, Amar V; Knudsen, Kenneth B; Knudsen, Thomas B

    2007-04-10

    Monitoring global gene expression provides insight into how genes and regulatory signals work together to guide embryo development. The fields of developmental biology and teratology are now confronted with the need for automated access to a reference library of gene-expression signatures that benchmark programmed (genetic) and adaptive (environmental) regulation of the embryonic transcriptome. Such a library must be constructed from highly-distributed microarray data. Birth Defects Systems Manager (BDSM), an open access knowledge management system, provides custom software to mine public microarray data focused on developmental health and disease. The present study describes tools for seamless data integration in the BDSM library (MetaSample, MetaChip, CIAeasy) using the QueryBDSM module. A field test of the prototype was run using published microarray data series derived from a variety of laboratories, experiments, microarray platforms, organ systems, and developmental stages. The datasets focused on several developing systems in the mouse embryo, including preimplantation stages, heart and nerve development, testis and ovary development, and craniofacial development. Using BDSM data integration tools, a gene-expression signature for 346 genes was resolved that accurately classified samples by organ system and developmental sequence. The module builds a potential for the BDSM approach to decipher a large number developmental processes through comparative bioinformatics analysis of embryological systems at-risk for specific defects, using multiple scenarios to define the range of probabilities leading from molecular phenotype to clinical phenotype. We conclude that an integrative analysis of global gene-expression of the developing embryo can form the foundation for constructing a reference library of signaling pathways and networks for normal and abnormal regulation of the embryonic transcriptome. These tools are available free of charge from the web-site http

  13. Metabolic properties of chicken embryonic stem cells

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Cellular energy metabolism correlates with cell fate,but the metabolic properties of chicken embryonic stem (chES) cells are poorly understood.Using a previously established chES cell model and electron microscopy (EM),we found that undifferentiated chES cells stored glycogen.Additionally,undifferentiated chES cells expressed lower levels of glucose transporter 1 (GLUT1) and phosphofructokinase (PFK) mRNAs but higher levels of hexokinase 1 (HK1) and glycogen synthase (GYS) mRNAs compared with control primary chicken embryonic fibroblast (CEF) cells,suggesting that chES cells direct glucose flux towards the glycogenic pathway.Moreover,we demonstrated that undifferentiated chES cells block gluconeogenic outflow and impede the accumulation of glucose-6-phosphate (G6P) from this pathway,as evidenced by the barely detectable levels of pyruvate carboxylase (PCX) and mitochondrial phosphoenolpyruvate carboxykinase (PCK2) mRNAs.Additionally,cell death occurred in undifferentiated chES cells as shown by Hoechst 33342 and propidium iodide (PI) double staining,but it could be rescued by exogenous G6P.However,we found that differentiated chES cells decreased the glycogen reserve through the use of PAS staining.Moreover,differentiated chES cells expressed higher levels of GLUT1,HK1 and PFK mRNAs,while the level of GYS mRNA remained similar in control CEF cells.These data indicate that undifferentiated chES cells continue to synthesize glycogen from glucose at the expense of G6P,while differentiated chES cells have a decreased glycogen reserve,which suggests that the amount of glycogen is indicative of the chES cell state.

  14. Human embryonic stem cells and microenvironment

    Directory of Open Access Journals (Sweden)

    Banu İskender

    2014-09-01

    Full Text Available Human embryonic stem cells (hESCs possess a great potential in the field of regenerative medicine by their virtue of pluripotent potential with indefinite proliferation capabilities. They can self renew themselves and differentiate into three embryonic germ layers. Although they are conventionally grown on mitotically inactivated mouse feeder cells, there are in vitro culture systems utilizing feeder cells of human origin in order to prevent cross-species contamination. Recently established in vitro culture systems suggested that direct interaction with feeder cells is not necessary but rather attachment to a substrate is required to ensure long-term, efficient hESC culture in vitro. This substrate is usually composed of a mixture of extracellular matrix components representing in vivo natural niche. In hESC biology, the mechanism of interaction of hESCs with extracellular matrix molecules remained insufficiently explored area of research due to their transient nature of interaction with the in vivo niche. However, an in vitro culture system established using extracellular matrix molecules may provide a safer alternative to culture systems with feeder cells while paving the way to Good Manufacturing Practice-GMP production of hESCs for therapeutic purposes. Therefore, it is essential to study the interaction of extracellular matrix molecules with hESCs in order to standardize in vitro culture systems for large-scale production of hESCs in a less labor-intensive way. This would not only provide valuable information regarding the mechanisms that control pluripotency but also serve to dissect the molecular signaling pathways of directed differentiation for prospective therapeutic applications in the future. J Clin Exp Invest 2014; 5 (3: 486-495

  15. Intestinal lineage commitment of embryonic stem cells.

    Science.gov (United States)

    Cao, Li; Gibson, Jason D; Miyamoto, Shingo; Sail, Vibhavari; Verma, Rajeev; Rosenberg, Daniel W; Nelson, Craig E; Giardina, Charles

    2011-01-01

    Generating lineage-committed intestinal stem cells from embryonic stem cells (ESCs) could provide a tractable experimental system for understanding intestinal differentiation pathways and may ultimately provide cells for regenerating damaged intestinal tissue. We tested a two-step differentiation procedure in which ESCs were first cultured with activin A to favor formation of definitive endoderm, and then treated with fibroblast-conditioned medium with or without Wnt3A. The definitive endoderm expressed a number of genes associated with gut-tube development through mouse embryonic day 8.5 (Sox17, Foxa2, and Gata4 expressed and Id2 silent). The intestinal stem cell marker Lgr5 gene was also activated in the endodermal cells, whereas the Msi1, Ephb2, and Dcamkl1 intestinal stem cell markers were not. Exposure of the endoderm to fibroblast-conditioned medium with Wnt3A resulted in the activation of Id2, the remaining intestinal stem cell markers and the later gut markers Cdx2, Fabp2, and Muc2. Interestingly, genes associated with distal gut-associated mesoderm (Foxf2, Hlx, and Hoxd8) were also simulated by Wnt3A. The two-step differentiation protocol generated gut bodies with crypt-like structures that included regions of Lgr5-expressing proliferating cells and regions of cell differentiation. These gut bodies also had a smooth muscle component and some underwent peristaltic movement. The ability of the definitive endoderm to differentiate into intestinal epithelium was supported by the vivo engraftment of these cells into mouse colonic mucosa. These findings demonstrate that definitive endoderm derived from ESCs can carry out intestinal cell differentiation pathways and may provide cells to restore damaged intestinal tissue.

  16. Embryonic environment and transgenerational effects in quail.

    Science.gov (United States)

    Leroux, Sophie; Gourichon, David; Leterrier, Christine; Labrune, Yann; Coustham, Vincent; Rivière, Sandrine; Zerjal, Tatiana; Coville, Jean-Luc; Morisson, Mireille; Minvielle, Francis; Pitel, Frédérique

    2017-01-26

    Environmental exposures, for instance to chemicals, are known to impact plant and animal phenotypes on the long term, sometimes across several generations. Such transgenerational phenotypes were shown to be promoted by epigenetic alterations such as DNA methylation, an epigenetic mark involved in the regulation of gene expression. However, it is yet unknown whether transgenerational epigenetic inheritance of altered phenotypes exists in birds. The purpose of this study was to develop an avian model to investigate whether changes to the embryonic environment had a transgenerational effect that could alter the phenotypes of third-generation offspring. Given its impact on the mammalian epigenome and the reproductive system in birds, genistein was used as an environment stressor. We compared several third-generation phenotypes of two quail "epilines", which were obtained from genistein-injected eggs (Epi+) or from untreated eggs (Epi-) from the same founders. A "mirrored" crossing strategy was used to minimize between-line genetic variability by maintaining similar ancestor contributions across generations in each line. Three generations after genistein treatment, a significant difference in the sexual maturity of the females, which, after three generations, could not be attributed to direct maternal effects, was observed between the lines, with Epi+ females starting to lay eggs later. Adult body weight was significantly affected by genistein treatment applied in a previous generation, and a significant interaction between line and sex was observed for body weight at 3 weeks. Behavioral traits, such as evaluating the birds' reaction to social isolation, were also significantly affected by genistein treatment. Yet, global methylation analyses revealed no significant difference between the epilines. These findings demonstrate that embryonic environment affects the phenotype of offspring three generations later in quail. While one cannot rule out the existence of some

  17. TAL-1/SCL and its partners E47 and LMO2 up-regulate VE-cadherin expression in endothelial cells.

    Science.gov (United States)

    Deleuze, Virginie; Chalhoub, Elias; El-Hajj, Rawan; Dohet, Christiane; Le Clech, Mikaël; Couraud, Pierre-Olivier; Huber, Philippe; Mathieu, Danièle

    2007-04-01

    The basic helix-loop-helix TAL-1/SCL essential for hematopoietic development is also required during vascular development for embryonic angiogenesis. We reported that TAL-1 acts positively on postnatal angiogenesis by stimulating endothelial morphogenesis. Here, we investigated the functional consequences of TAL-1 silencing in human primary endothelial cells. We found that TAL-1 knockdown caused the inhibition of in vitro tubulomorphogenesis, which was associated with a dramatic reduction in vascular endothelial cadherin (VE-cadherin) at intercellular junctions. Consistently, silencing of TAL-1 as well as of its cofactors E47 and LMO2 down-regulated VE-cadherin at both the mRNA and the protein level. Endogenous VE-cadherin transcription could be activated in nonendothelial HEK-293 cells by the sole concomitant ectopic expression of TAL-1, E47, and LMO2. Transient transfections in human primary endothelial cells derived from umbilical vein (HUVECs) demonstrated that VE-cadherin promoter activity was dependent on the integrity of a specialized E-box associated with a GATA motif and was maximal with the coexpression of the different components of the TAL-1 complex. Finally, chromatin immunoprecipitation assays showed that TAL-1 and its cofactors occupied the VE-cadherin promoter in HUVECs. Together, these data identify VE-cadherin as a bona fide target gene of the TAL-1 complex in the endothelial lineage, providing a first clue to TAL-1 function in angiogenesis.

  18. Cell adhesion and sorting in embryoid bodies derived from N- or E-cadherin deficient murine embryonic stem cells

    Directory of Open Access Journals (Sweden)

    Robert Moore

    2014-01-01

    The primitive endoderm epithelial structure in mouse blastocysts forms following cell differentiation and subsequent sorting, and this two-step process can be reproduced in vitro using an embryoid body model. We found that in the chimeric embryoid bodies consisting of paired wildtype and E-cadherin null ES cells, the wildtype sorted to the center and were enveloped by the less adhesive E-cadherin null cells, in accord with Steinberg's hypothesis. However, wildtype and N-cadherin null ES cells intermixed and did not segregate, a situation that may be explained by Albert Harris' modified principle, which incorporates the unique properties of living cells. Furthermore, in chimeric embryoid bodies composed of N-cadherin and E-cadherin null ES cells, the two weakly interacting cell types segregated but did not envelop one another. Lastly, the most consistent and striking observation was that differentiated cells sorted to the surface and formed an enveloping layer, regardless of the relative cell adhesive affinity of any cell combination, supporting the hypothesis that the ability of the differentiated cells to establish apical polarity is the determining factor in surface sorting and positioning.

  19. Altered expression of heat shock proteins in embryonal carcinoma and mouse early embryonic cells.

    Science.gov (United States)

    Morange, M; Diu, A; Bensaude, O; Babinet, C

    1984-04-01

    In a previous paper, we have shown that in the absence of stress, mouse embryonal carcinoma cells, like mouse early embryo multipotent cells, synthesize high levels of 89- and 70-kilodalton heat shock proteins (HSP)(O. Bensaude and M. Morange, EMBO J. 2:173-177, 1983). We report here the pattern of proteins synthesized after a short period of hyperthermia in various mouse embryonal carcinoma cell lines and early mouse embryo cells. Among the various cell lines tested, two of them, PCC4-Aza R1 and PCC7-S-1009, showed an unusual response in that stimulation of HSP synthesis was not observed in these cells after hyperthermia. However, inducibility of 68- and 105-kilodalton HSP can be restored in PCC7-S-1009 cells after in vitro differentiation triggered by retinoic acid. Similarly, in the early mouse embryo, hyperthermia does not induce the synthesis of nonconstitutive HSP at the eight-cell stage, but induction of the 68-kilodalton HSP does occur at the blastocyst stage. Such a transition in the expression of HSP has already been described for Drosophila melanogaster and sea urchin embryos and recently for mouse embryos. It may be a general property of early embryonic cells.

  20. Vascular endothelial growth factor co-ordinates proper development of lung epithelium and vasculature.

    Science.gov (United States)

    Zhao, Liqing; Wang, Ke; Ferrara, Napoleone; Vu, Thiennu H

    2005-07-01

    The vasculature forms an intrinsic functional component of the lung and its development must be tightly regulated and coordinated with lung epithelial morphogenesis. Vascular endothelial growth factor (VEGF) and its receptors are highly expressed in a complementary pattern in the lungs during embryonic development. VEGF is expressed by epithelium and the receptors in the surrounding mesenchyme. To determine the function of VEGF in lung formation, we inhibited its activity using a soluble receptor in lung renal capsule grafts. Inhibition of VEGF results in inhibition of vascular development and significant alteration in epithelial development. Epithelial proliferation is inhibited, sacculation is impaired, and the epithelium undergoes apoptosis. Interestingly, when VEGF is attenuated, epithelial differentiation still proceeds, as shown by acquisition of both proximal and distal markers. These data show that VEGF co-ordinates epithelial and vascular development. It is required for the development of the lung vasculature and the vasculature is necessary for epithelial proliferation and morphogenesis, but not for cell differentiation.

  1. Vascular Endothelial Growth Factor Receptor 3 Controls Neural Stem Cell Activation in Mice and Humans

    Directory of Open Access Journals (Sweden)

    Jinah Han

    2015-02-01

    Full Text Available Neural stem cells (NSCs continuously produce new neurons within the adult mammalian hippocampus. NSCs are typically quiescent but activated to self-renew or differentiate into neural progenitor cells. The molecular mechanisms of NSC activation remain poorly understood. Here, we show that adult hippocampal NSCs express vascular endothelial growth factor receptor (VEGFR 3 and its ligand VEGF-C, which activates quiescent NSCs to enter the cell cycle and generate progenitor cells. Hippocampal NSC activation and neurogenesis are impaired by conditional deletion of Vegfr3 in NSCs. Functionally, this is associated with compromised NSC activation in response to VEGF-C and physical activity. In NSCs derived from human embryonic stem cells (hESCs, VEGF-C/VEGFR3 mediates intracellular activation of AKT and ERK pathways that control cell fate and proliferation. These findings identify VEGF-C/VEGFR3 signaling as a specific regulator of NSC activation and neurogenesis in mammals.

  2. Effects of vascular endothelial growth factor on angiogenesis of the endothelial cells isolated from cavernous malformations

    Institute of Scientific and Technical Information of China (English)

    TAN YuZhen; ZHAO Yao; WANG HaiJie; ZHOU LiangFu; MAO Ying; LIU Rui; SHU Jia; WANG YongFei

    2008-01-01

    Human cerebral cavernous malformation (CM) is a common vascular malformation of the central nervous system. We have investigated the biological characteristics of CM endothelial cells and the cellular and molecular mechanisms of CM angiogenesis to offer new insights into exploring effective measures for treatment of this disease. The endothelial cells were isolated from CM tissue masses dissected during operation and expanded in vitro. Expression of VEGFR-1 and VEGFR-2 was examined with immunocytochemical staining. Proliferation, migration and tube formation of CM endothelial cells were determined using MTT, wounding and transmigration assays, and three-dimensional collagen type Ⅰ gel respectively. The endothelial cells were successfully isolated from the tissue specimens of 25 CMs dissected without dipolar electrocoagulation. The cells show the general characteristics of the vascular endothelial cells. Expression of VEGFR-1 and VEGFR-2 on the cells is higher than that on the normal cerebral microvascular endothelial cells. After treatment with VEGF, numbers of the proliferated and migrated cells, the maximal distance of cell migration and the length and area of capillary-like struc-tures formed in the three-dimensional collagen gel increase significantly. These results demonstrate that expression of VEGFR-1 and VEGFR-2 on CM endothelial cells is up-regulated. By binding to re-ceptors, VEGF may activate the downstream signaling pathways and promote proliferation, migration and tube formation of CM endothelial cells. VEGF/VEGFR signaling pathways play important regulating roles in CM angiogenesis.

  3. Reduced Ang2 expression in aging endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Hohensinner, P.J., E-mail: philipp.hohensinner@meduniwien.ac.at [Department of Internal Medicine II, Medical University of Vienna, Vienna (Austria); Ebenbauer, B. [Department of Internal Medicine II, Medical University of Vienna, Vienna (Austria); Ludwig Boltzmann Cluster for Cardiovascular Research, Vienna (Austria); Kaun, C.; Maurer, G. [Department of Internal Medicine II, Medical University of Vienna, Vienna (Austria); Huber, K. [Ludwig Boltzmann Cluster for Cardiovascular Research, Vienna (Austria); 3rd Medical Department, Wilhelminenhospital, Vienna (Austria); Sigmund Freud University, Medical Faculty, Vienna (Austria); Wojta, J. [Department of Internal Medicine II, Medical University of Vienna, Vienna (Austria); Ludwig Boltzmann Cluster for Cardiovascular Research, Vienna (Austria); Core Facilities, Medical University of Vienna, Vienna (Austria)

    2016-06-03

    Aging endothelial cells are characterized by increased cell size, reduced telomere length and increased expression of proinflammatory cytokines. In addition, we describe here that aging reduces the migratory distance of endothelial cells. Furthermore, we observe an increase of the quiescence protein Ang1 and a decrease of the endothelial activation protein Ang2 upon aging. Supplementing Ang2 to aged endothelial cells restored their migratory capacity. We conclude that aging shifts the balance of the Ang1/Ang2 network favouring a quiescent state. Activation of endothelial cells in aging might be necessary to enhance wound healing capacities. -- Highlights: •Endothelial cells display signs of aging before reaching proliferative senescence. •Aging endothelial cells express more angiopoietin 1 and less angiopoietin 2 than young endothelial cells. •Migratory capacity is reduced in aging endothelial cells.

  4. Caffeine acts via A1 adenosine receptors to disrupt embryonic cardiac function.

    Directory of Open Access Journals (Sweden)

    Daniela L Buscariollo

    Full Text Available BACKGROUND: Evidence suggests that adenosine acts via cardiac A1 adenosine receptors (A1ARs to protect embryos against hypoxia. During embryogenesis, A1ARs are the dominant regulator of heart rate, and A1AR activation reduces heart rate. Adenosine action is inhibited by caffeine, which is widely consumed during pregnancy. In this study, we tested the hypothesis that caffeine influences developing embryos by altering cardiac function. METHODOLOGY/PRINCIPAL FINDINGS: Effects of caffeine and adenosine receptor-selective antagonists on heart rate were studied in vitro using whole murine embryos at E9.5 and isolated hearts at E12.5. Embryos were examined in room air (21% O(2 or hypoxic (2% O(2 conditions. Hypoxia decreased heart rates of E9.5 embryos by 15.8% and in E12.5 isolated hearts by 27.1%. In room air, caffeine (200 µM had no effect on E9.5 heart rates; however, caffeine increased heart rates at E12.5 by 37.7%. Caffeine abolished hypoxia-mediated bradycardia at E9.5 and blunted hypoxia-mediated bradycardia at E12.5. Real-time PCR analysis of RNA from isolated E9.5 and E12.5 hearts showed that A1AR and A2aAR genes were expressed at both ages. Treatment with adenosine receptor-selective antagonists revealed that SCH-58261 (A2aAR-specific antagonist had no affects on heart function, whereas DPCPX (A1AR-specific antagonist had effects similar to caffeine treatment at E9.5 and E12.5. At E12.5, embryonic hearts lacking A1AR expression (A1AR-/- had elevated heart rates compared to A1AR+/- littermates, A1AR-/- heart rates failed to decrease to levels comparable to those of controls. Caffeine did not significantly affect heart rates of A1AR-/- embryos. CONCLUSIONS/SIGNIFICANCE: These data show that caffeine alters embryonic cardiac function and disrupts the normal cardiac response to hypoxia through blockade of A1AR action. Our results raise concern for caffeine exposure during embryogenesis, particularly in pregnancies with increased risk of

  5. Protection of Coronary Endothelial Function during Cardiac Surgery: Potential of Targeting Endothelial Ion Channels in Cardioprotection

    Directory of Open Access Journals (Sweden)

    Qin Yang

    2014-01-01

    Full Text Available Vascular endothelium plays a critical role in the control of blood flow by producing vasoactive factors to regulate vascular tone. Ion channels, in particular, K+ channels and Ca2+-permeable channels in endothelial cells, are essential to the production and function of endothelium-derived vasoactive factors. Impairment of coronary endothelial function occurs in open heart surgery that may result in reduction of coronary blood flow and thus in an inadequate myocardial perfusion. Hyperkalemic exposure and concurrent ischemia-reperfusion during cardioplegic intervention compromise NO and EDHF-mediated function and the impairment involves alterations of K+ channels, that is, KATP and KCa, and Ca2+-permeable TRP channels in endothelial cells. Pharmacological modulation of these channels during ischemia-reperfusion and hyperkalemic exposure show promising results on the preservation of NO and EDHF-mediated endothelial function, which suggests the potential of targeting endothelial K+ and TRP channels for myocardial protection during cardiac surgery.

  6. Metabolic activation capacity by primary hepatocytes expands the applicability of the embryonic stem cell test as alternative to experimental animal testing.

    Science.gov (United States)

    Hettwer, Michael; Reis-Fernandes, Marcos A; Iken, Marcus; Ott, Michael; Steinberg, Pablo; Nau, Heinz

    2010-08-01

    The murine embryonic stem cell test (EST) represents a validated alternative method for in vivo embryotoxicity testing. In the present study, primary hepatocytes were combined with the EST by a preincubation approach to improve its predictivity on bioactivation caused teratogenicity. As substances the well-known proteratogens cyclophosphamide (CPA) and valpromide (VPD) were used. The embryotoxic potential of CPA was detected by a strong decrease of the resulting ID(50)-concentration (50% inhibition of ES cell differentiation) after incubation with murine hepatocytes. Interspecies variation in metabolism was detected by testing VPD. After incubation of VPD with murine hepatocytes no inhibition of ES cell differentiation was observed, since hardly any teratogenic VPD metabolites were formed. In contrast, with human hepatocytes a significant conversion of VPD into the teratogen valproic acid (VPA) was observed. In summary we developed a co-culture approach for embryotoxicity testing, whereby the test compounds were incubated with hepatocytes and the supernatant was added to the ES cell culture to obtain a dose dependency of the preincubated test substances. Copyright 2010 Elsevier Inc. All rights reserved.

  7. Growth-promoting effects of different fractions of extra-embryonic coelomic fluid on embryonic development.

    Science.gov (United States)

    Karabulut, A K; Layfield, R; Pratten, M K