WorldWideScience

Sample records for progenitor lineage commitment

  1. Transcriptional Heterogeneity and Lineage Commitment in Myeloid Progenitors

    DEFF Research Database (Denmark)

    Paul, Franziska; Arkin, Ya'ara; Giladi, Amir

    2015-01-01

    Within the bone marrow, stem cells differentiate and give rise to diverse blood cell types and functions. Currently, hematopoietic progenitors are defined using surface markers combined with functional assays that are not directly linked with in vivo differentiation potential or gene regulatory m...

  2. IL-4/IL-13 Signaling Inhibits the Potential of Early Thymic Progenitors To Commit to the T Cell Lineage.

    Science.gov (United States)

    Barik, Subhasis; Miller, Mindy M; Cattin-Roy, Alexis N; Ukah, Tobechukwu K; Chen, Weirong; Zaghouani, Habib

    2017-10-15

    Early thymic progenitors (ETPs) are endowed with diverse potencies and can give rise to myeloid and lymphoid lineage progenitors. How the thymic environment guides ETP commitment and maturation toward a specific lineage remains obscure. We have previously shown that ETPs expressing the heteroreceptor (HR) comprising IL-4Rα and IL-13Rα1 give rise to myeloid cells but not T cells. In this article, we show that signaling through the HR inhibits ETP maturation to the T cell lineage but enacts commitment toward the myeloid cells. Indeed, HR + ETPs, but not HR - ETPs, exhibit activated STAT6 transcription factor, which parallels with downregulation of Notch1, a critical factor for T cell development. Meanwhile, the myeloid-specific transcription factor C/EBPα, usually under the control of Notch1, is upregulated. Furthermore, in vivo inhibition of STAT6 phosphorylation restores Notch1 expression in HR + ETPs, which regain T lineage potential. In addition, upon stimulation with IL-4 or IL-13, HR - ETPs expressing virally transduced HR also exhibit STAT6 phosphorylation and downregulation of Notch1, leading to inhibition of lymphoid, but not myeloid, lineage potential. These observations indicate that environmental cytokines play a role in conditioning ETP lineage choice, which would impact T cell development. Copyright © 2017 by The American Association of Immunologists, Inc.

  3. Mesenchymal progenitor cells for the osteogenic lineage.

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    Ono, Noriaki; Kronenberg, Henry M

    2015-09-01

    Mesenchymal progenitors of the osteogenic lineage provide the flexibility for bone to grow, maintain its function and homeostasis. Traditionally, colony-forming-unit fibroblasts (CFU-Fs) have been regarded as surrogates for mesenchymal progenitors; however, this definition cannot address the function of these progenitors in their native setting. Transgenic murine models including lineage-tracing technologies based on the cre-lox system have proven to be useful in delineating mesenchymal progenitors in their native environment. Although heterogeneity of cell populations of interest marked by a promoter-based approach complicates overall interpretation, an emerging complexity of mesenchymal progenitors has been revealed. Current literatures suggest two distinct types of bone progenitor cells; growth-associated mesenchymal progenitors contribute to explosive growth of bone in early life, whereas bone marrow mesenchymal progenitors contribute to the much slower remodeling process and response to injury that occurs mainly in adulthood. More detailed relationships of these progenitors need to be studied through further experimentation.

  4. Even Cancers Want Commitment: Lineage Identity and Medulloblastoma Formation

    Science.gov (United States)

    Eberhart, Charles G.

    2015-01-01

    In this issue of Cancer Cell, Yang et al. (2008) and Schüller et al. (2008) show that Hedgehog activation in either multipotent neural stem cells or developmentally restricted progenitors causes only medulloblastomas to form. These data suggest that some stem cell-derived tumors must commit to a specific lineage in order to grow. PMID:18691544

  5. Lack of the p42 form of C/EBPα leads to spontaneous immortalization and lineage infidelity of committed myeloid progenitors

    DEFF Research Database (Denmark)

    Schuster, Mikkel B; Frank, Anne-Katrine; Bagger, Frederik O

    2013-01-01

    transforming events. In this study, we use premalignant cells from a Cebpa mutant AML model, in which the LIC population resembles granulocyte-macrophage progenitors (GMPs), to show that premalignant GMPs undergo spontaneous immortalization with a high clonal frequency when cultured in vitro, suggesting...

  6. Luminal progenitors restrict their lineage potential during mammary gland development.

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    Rodilla, Veronica; Dasti, Alessandro; Huyghe, Mathilde; Lafkas, Daniel; Laurent, Cécile; Reyal, Fabien; Fre, Silvia

    2015-02-01

    The hierarchical relationships between stem cells and progenitors that guide mammary gland morphogenesis are still poorly defined. While multipotent basal stem cells have been found within the myoepithelial compartment, the in vivo lineage potential of luminal progenitors is unclear. Here we used the expression of the Notch1 receptor, previously implicated in mammary gland development and tumorigenesis, to elucidate the hierarchical organization of mammary stem/progenitor cells by lineage tracing. We found that Notch1 expression identifies multipotent stem cells in the embryonic mammary bud, which progressively restrict their lineage potential during mammary ductal morphogenesis to exclusively generate an ERαneg luminal lineage postnatally. Importantly, our results show that Notch1-labelled cells represent the alveolar progenitors that expand during pregnancy and survive multiple successive involutions. This study reveals that postnatal luminal epithelial cells derive from distinct self-sustained lineages that may represent the cells of origin of different breast cancer subtypes.

  7. Imaging retinal progenitor lineages in developing zebrafish embryos.

    Science.gov (United States)

    Jusuf, Patricia; Harris, William A; Poggi, Lucia

    2013-03-01

    In this protocol, we describe how to make and analyze four dimensional (4D) movies of retinal lineage in the zebrafish embryo in vivo. 4D consists of three spatial dimensions (3D) reconstructed from stacks of confocal planes plus one time dimension. Our imaging is performed on transgenic cells that express fluorescent proteins under the control of cell-specific promoters or on cells that transiently express such reporters in specific retinal cell progenitors. An important aspect of lineage tracing is the ability to follow individual cells as they undergo multiple cell divisions, final migration, and differentiation. This may mean many hours of 4D imaging, requiring that cells be kept healthy and maintained under conditions suitable for normal development. The longest movies we have made are ∼50 h. By analyzing these movies, we can see when a specific cell was born and who its sister was, allowing us to reconstruct its retinal lineages in vivo.

  8. Dendritic Cell Lineage Potential in Human Early Hematopoietic Progenitors

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    Julie Helft

    2017-07-01

    Full Text Available Conventional dendritic cells (cDCs are thought to descend from a DC precursor downstream of the common myeloid progenitor (CMP. However, a mouse lymphoid-primed multipotent progenitor has been shown to generate cDCs following a DC-specific developmental pathway independent of monocyte and granulocyte poiesis. Similarly, here we show that, in humans, a large fraction of multipotent lymphoid early progenitors (MLPs gives rise to cDCs, in particular the subset known as cDC1, identified by co-expression of DNGR-1 (CLEC9A and CD141 (BDCA-3. Single-cell analysis indicates that over one-third of MLPs have the potential to efficiently generate cDCs. cDC1s generated from CMPs or MLPs do not exhibit differences in transcriptome or phenotype. These results demonstrate an early imprinting of the cDC lineage in human hematopoiesis and highlight the plasticity of developmental pathways giving rise to human DCs.

  9. TLX activates MASH1 for induction of neuronal lineage commitment of adult hippocampal neuroprogenitors.

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    Elmi, Muna; Matsumoto, Yoshiki; Zeng, Zhao-jun; Lakshminarasimhan, Pavithra; Yang, Weiwen; Uemura, Akiyoshi; Nishikawa, Shin-ichi; Moshiri, Alicia; Tajima, Nobuyoshi; Agren, Hans; Funa, Keiko

    2010-10-01

    The orphan nuclear receptor TLX has been proposed to act as a repressor of cell cycle inhibitors to maintain the neural stem cells in an undifferentiated state, and prevents commitment into astrocyte lineages. However, little is known about the mechanism of TLX in neuronal lineage commitment and differentiation. A majority of adult rat hippocampus-derived progenitors (AHPs) cultured in the presence of FGF express a high level of TLX and a fraction of these cells also express the proneural gene MASH1. Upon FGF withdrawal, TLX rapidly decreased, while MASH1 was intensely expressed within 1h, decreasing gradually to disappear at 24h. Adenoviral transduction of TLX in AHP cells in the absence of FGF transiently increased cell proliferation, however, later resulted in neuronal differentiation by inducing MASH1, Neurogenin1, DCX, and MAP2ab. Furthermore, TLX directly targets and activates the MASH1 promoter through interaction with Sp1, recruiting co-activators whereas dismissing the co-repressor HDAC4. Conversely, silencing of TLX in AHPs decreased beta-III tubulin and DCX expression and promoted glial differentiation. Our results thus suggest that TLX not only acts as a repressor of cell cycle and glial differentiation but also activates neuronal lineage commitment in AHPs. Copyright 2010 Elsevier Inc. All rights reserved.

  10. Hydroxymethylation at Gene Regulatory Regions Directs Stem/Early Progenitor Cell Commitment during Erythropoiesis

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    Jozef Madzo

    2014-01-01

    Full Text Available Hematopoietic stem cell differentiation involves the silencing of self-renewal genes and induction of a specific transcriptional program. Identification of multiple covalent cytosine modifications raises the question of how these derivatized bases influence stem cell commitment. Using a replicative primary human hematopoietic stem/progenitor cell differentiation system, we demonstrate dynamic changes of 5-hydroxymethylcytosine (5-hmC during stem cell commitment and differentiation to the erythroid lineage. Genomic loci that maintain or gain 5-hmC density throughout erythroid differentiation contain binding sites for erythroid transcription factors and several factors not previously recognized as erythroid-specific factors. The functional importance of 5-hmC was demonstrated by impaired erythroid differentiation, with augmentation of myeloid potential, and disrupted 5-hmC patterning in leukemia patient-derived CD34+ stem/early progenitor cells with TET methylcytosine dioxygenase 2 (TET2 mutations. Thus, chemical conjugation and affinity purification of 5-hmC-enriched sequences followed by sequencing serve as resources for deciphering functional implications for gene expression during stem cell commitment and differentiation along a particular lineage.

  11. Lineage-related cytotoxicity and clonogenic profile of 1,4-benzoquinone-exposed hematopoietic stem and progenitor cells

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    Chow, Paik Wah [Biomedical Science Programme, School of Diagnostic & Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Abdul Muda Aziz, 50300 Kuala Lumpur, Wilayah Persekutuan (Malaysia); Toxicology Laboratory, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur (Malaysia); Abdul Hamid, Zariyantey, E-mail: zyantey@ukm.edu.my [Biomedical Science Programme, School of Diagnostic & Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Abdul Muda Aziz, 50300 Kuala Lumpur, Wilayah Persekutuan (Malaysia); Toxicology Laboratory, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur (Malaysia); Chan, Kok Meng [Environmental Health and Industrial Safety Programme, School of Diagnostic & Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Abdul Muda Aziz, 50300 Kuala Lumpur, Wilayah Persekutuan (Malaysia); Toxicology Laboratory, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur (Malaysia); Inayat-Hussain, Salmaan Hussain [Environmental Health and Industrial Safety Programme, School of Diagnostic & Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Abdul Muda Aziz, 50300 Kuala Lumpur, Wilayah Persekutuan (Malaysia); Rajab, Nor Fadilah [Biomedical Science Programme, School of Diagnostic & Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Abdul Muda Aziz, 50300 Kuala Lumpur, Wilayah Persekutuan (Malaysia); Toxicology Laboratory, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur (Malaysia)

    2015-04-01

    Hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) are sensitive targets for benzene-induced hematotoxicity and leukemogenesis. The impact of benzene exposure on the complex microenvironment of HSCs and HPCs remains elusive. This study aims to investigate the mechanism linking benzene exposure to targeting HSCs and HPCs using phenotypic and clonogenic analyses. Mouse bone marrow (BM) cells were exposed ex vivo to the benzene metabolite, 1,4-benzoquinone (1,4-BQ), for 24 h. Expression of cellular surface antigens for HSC (Sca-1), myeloid (Gr-1, CD11b), and lymphoid (CD45, CD3e) populations were confirmed by flow cytometry. The clonogenicity of cells was studied using the colony-forming unit (CFU) assay for multilineage (CFU-GM and CFU-GEMM) and single-lineage (CFU-E, BFU-E, CFU-G, and CFU-M) progenitors. 1,4-BQ demonstrated concentration-dependent cytotoxicity in mouse BM cells. The percentage of apoptotic cells increased (p < 0.05) following 1,4-BQ exposure. Exposure to 1,4-BQ showed no significant effect on CD3e{sup +} cells but reduced the total counts of Sca-1{sup +}, CD11b{sup +}, Gr-1{sup +}, and CD45{sup +} cells at 7 and 12 μM (p < 0.05). Furthermore, the CFU assay showed reduced (p < 0.05) clonogenicity in 1,4-BQ-treated cells. 1,4-BQ induced CFU-dependent cytotoxicity by significantly inhibiting colony growth for CFU-E, BFU-E, CFU-G, and CFU-M starting at a low concentration of exposure (5 μM); whereas for the CFU-GM and CFU-GEMM, the inhibition of colony growth was remarkable only at 7 and 12 μM of 1,4-BQ, respectively. Taken together, 1,4-BQ caused lineage-related cytotoxicity in mouse HPCs, demonstrating greater toxicity in single-lineage progenitors than in those of multi-lineage. - Highlights: • We examine 1,4-BQ toxicity targeting mouse hematopoietic cell lineages. • 1,4-BQ induces concentration-dependent cytotoxicity in bone marrow (BM) cells. • 1,4-BQ shows lineage-related toxicity on hematopoietic stem and

  12. Lineage-related cytotoxicity and clonogenic profile of 1,4-benzoquinone-exposed hematopoietic stem and progenitor cells

    International Nuclear Information System (INIS)

    Chow, Paik Wah; Abdul Hamid, Zariyantey; Chan, Kok Meng; Inayat-Hussain, Salmaan Hussain; Rajab, Nor Fadilah

    2015-01-01

    Hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) are sensitive targets for benzene-induced hematotoxicity and leukemogenesis. The impact of benzene exposure on the complex microenvironment of HSCs and HPCs remains elusive. This study aims to investigate the mechanism linking benzene exposure to targeting HSCs and HPCs using phenotypic and clonogenic analyses. Mouse bone marrow (BM) cells were exposed ex vivo to the benzene metabolite, 1,4-benzoquinone (1,4-BQ), for 24 h. Expression of cellular surface antigens for HSC (Sca-1), myeloid (Gr-1, CD11b), and lymphoid (CD45, CD3e) populations were confirmed by flow cytometry. The clonogenicity of cells was studied using the colony-forming unit (CFU) assay for multilineage (CFU-GM and CFU-GEMM) and single-lineage (CFU-E, BFU-E, CFU-G, and CFU-M) progenitors. 1,4-BQ demonstrated concentration-dependent cytotoxicity in mouse BM cells. The percentage of apoptotic cells increased (p < 0.05) following 1,4-BQ exposure. Exposure to 1,4-BQ showed no significant effect on CD3e + cells but reduced the total counts of Sca-1 + , CD11b + , Gr-1 + , and CD45 + cells at 7 and 12 μM (p < 0.05). Furthermore, the CFU assay showed reduced (p < 0.05) clonogenicity in 1,4-BQ-treated cells. 1,4-BQ induced CFU-dependent cytotoxicity by significantly inhibiting colony growth for CFU-E, BFU-E, CFU-G, and CFU-M starting at a low concentration of exposure (5 μM); whereas for the CFU-GM and CFU-GEMM, the inhibition of colony growth was remarkable only at 7 and 12 μM of 1,4-BQ, respectively. Taken together, 1,4-BQ caused lineage-related cytotoxicity in mouse HPCs, demonstrating greater toxicity in single-lineage progenitors than in those of multi-lineage. - Highlights: • We examine 1,4-BQ toxicity targeting mouse hematopoietic cell lineages. • 1,4-BQ induces concentration-dependent cytotoxicity in bone marrow (BM) cells. • 1,4-BQ shows lineage-related toxicity on hematopoietic stem and progenitors. • 1,4-BQ

  13. Developmental fate and lineage commitment of singled mouse blastomeres.

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    Lorthongpanich, Chanchao; Doris, Tham Puay Yoke; Limviphuvadh, Vachiranee; Knowles, Barbara B; Solter, Davor

    2012-10-01

    The inside-outside model has been invoked to explain cell-fate specification of the pre-implantation mammalian embryo. Here, we investigate whether cell-cell interaction can influence the fate specification of embryonic blastomeres by sequentially separating the blastomeres in two-cell stage mouse embryos and continuing separation after each cell division throughout pre-implantation development. This procedure eliminates information provided by cell-cell interaction and cell positioning. Gene expression profiles, polarity protein localization and functional tests of these separated blastomeres reveal that cell interactions, through cell position, influence the fate of the blastomere. Blastomeres, in the absence of cell contact and inner-outer positional information, have a unique pattern of gene expression that is characteristic of neither inner cell mass nor trophectoderm, but overall they have a tendency towards a 'trophectoderm-like' gene expression pattern and preferentially contribute to the trophectoderm lineage.

  14. Transcriptional regulation of lineage commitment--a stochastic model of cell fate decisions.

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    Jose Teles

    Full Text Available Molecular mechanisms employed by individual multipotent cells at the point of lineage commitment remain largely uncharacterized. Current paradigms span from instructive to noise-driven mechanisms. Of considerable interest is also whether commitment involves a limited set of genes or the entire transcriptional program, and to what extent gene expression configures multiple trajectories into commitment. Importantly, the transient nature of the commitment transition confounds the experimental capture of committing cells. We develop a computational framework that simulates stochastic commitment events, and affords mechanistic exploration of the fate transition. We use a combined modeling approach guided by gene expression classifier methods that infers a time-series of stochastic commitment events from experimental growth characteristics and gene expression profiling of individual hematopoietic cells captured immediately before and after commitment. We define putative regulators of commitment and probabilistic rules of transition through machine learning methods, and employ clustering and correlation analyses to interrogate gene regulatory interactions in multipotent cells. Against this background, we develop a Monte Carlo time-series stochastic model of transcription where the parameters governing promoter status, mRNA production and mRNA decay in multipotent cells are fitted to experimental static gene expression distributions. Monte Carlo time is converted to physical time using cell culture kinetic data. Probability of commitment in time is a function of gene expression as defined by a logistic regression model obtained from experimental single-cell expression data. Our approach should be applicable to similar differentiating systems where single cell data is available. Within our system, we identify robust model solutions for the multipotent population within physiologically reasonable values and explore model predictions with regard to

  15. Sonic hedgehog lineage in the mouse hypothalamus: from progenitor domains to hypothalamic regions

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    Alvarez-Bolado Gonzalo

    2012-01-01

    Full Text Available Abstract Background The hypothalamus is a brain region with essential functions for homeostasis and energy metabolism, and alterations of its development can contribute to pathological conditions in the adult, like hypertension, diabetes or obesity. However, due to the anatomical complexity of the hypothalamus, its development is not well understood. Sonic hedgehog (Shh is a key developmental regulator gene expressed in a dynamic pattern in hypothalamic progenitor cells. To obtain insight into hypothalamic organization, we used genetic inducible fate mapping (GIFM to map the lineages derived from Shh-expressing progenitor domains onto the four rostrocaudally arranged hypothalamic regions: preoptic, anterior, tuberal and mammillary. Results Shh-expressing progenitors labeled at an early stage (before embryonic day (E9.5 contribute neurons and astrocytes to a large caudal area including the mammillary and posterior tuberal regions as well as tanycytes (specialized median eminence glia. Progenitors labeled at later stages (after E9.5 give rise to neurons and astrocytes of the entire tuberal region and in particular the ventromedial nucleus, but not to cells in the mammillary region and median eminence. At this stage, an additional Shh-expressing domain appears in the preoptic area and contributes mostly astrocytes to the hypothalamus. Shh-expressing progenitors do not contribute to the anterior region at any stage. Finally, we show a gradual shift from neurogenesis to gliogenesis, so that progenitors expressing Shh after E12.5 generate almost exclusively hypothalamic astrocytes. Conclusions We define a fate map of the hypothalamus, based on the dynamic expression of Shh in the hypothalamic progenitor zones. We provide evidence that the large neurogenic Shh-expressing progenitor domains of the ventral diencephalon are continuous with those of the midbrain. We demonstrate that the four classical transverse zones of the hypothalamus have clearly

  16. Dynamics of lineage commitment revealed by single-cell transcriptomics of differentiating embryonic stem cells

    NARCIS (Netherlands)

    Semrau, Stefan; Goldmann, Johanna E; Soumillon, Magali; Mikkelsen, Tarjei S; Jaenisch, Rudolf; van Oudenaarden, Alexander

    2017-01-01

    Gene expression heterogeneity in the pluripotent state of mouse embryonic stem cells (mESCs) has been increasingly well-characterized. In contrast, exit from pluripotency and lineage commitment have not been studied systematically at the single-cell level. Here we measure the gene expression

  17. Polo-Like Kinase 2 is Dynamically Regulated to Coordinate Proliferation and Early Lineage Specification Downstream of Yes-Associated Protein 1 in Cardiac Progenitor Cells.

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    Mochizuki, Michika; Lorenz, Vera; Ivanek, Robert; Della Verde, Giacomo; Gaudiello, Emanuele; Marsano, Anna; Pfister, Otmar; Kuster, Gabriela M

    2017-10-24

    Recent studies suggest that adult cardiac progenitor cells (CPCs) can produce new cardiac cells. Such cell formation requires an intricate coordination of progenitor cell proliferation and commitment, but the molecular cues responsible for this regulation in CPCs are ill defined. Extracellular matrix components are important instructors of cell fate. Using laminin and fibronectin, we induced two slightly distinct CPC phenotypes differing in proliferation rate and commitment status and analyzed the early transcriptomic response to CPC adhesion (<2 hours). Ninety-four genes were differentially regulated on laminin versus fibronectin, consisting of mostly downregulated genes that were enriched for Yes-associated protein (YAP) conserved signature and TEA domain family member 1 (TEAD1)-related genes. This early gene regulation was preceded by the rapid cytosolic sequestration and degradation of YAP on laminin. Among the most strongly regulated genes was polo-like kinase 2 ( Plk2 ). Plk2 expression depended on YAP stability and was enhanced in CPCs transfected with a nuclear-targeted mutant YAP. Phenotypically, the early downregulation of Plk2 on laminin was succeeded by lower cell proliferation, enhanced lineage gene expression (24 hours), and facilitated differentiation (3 weeks) compared with fibronectin. Finally, overexpression of Plk2 enhanced CPC proliferation and knockdown of Plk2 induced the expression of lineage genes. Plk2 acts as coordinator of cell proliferation and early lineage commitment in CPCs. The rapid downregulation of Plk2 on YAP inactivation marks a switch towards enhanced commitment and facilitated differentiation. These findings link early gene regulation to cell fate and provide novel insights into how CPC proliferation and differentiation are orchestrated. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  18. Direct lineage reprogramming of mouse fibroblasts to functional midbrain dopaminergic neuronal progenitors

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    Han-Seop Kim

    2014-01-01

    Full Text Available The direct lineage reprogramming of somatic cells to other lineages by defined factors has led to innovative cell-fate-change approaches for providing patient-specific cells. Recent reports have demonstrated that four pluripotency factors (Oct4, Sox2, Klf4, and c-Myc are sufficient to directly reprogram fibroblasts to other specific cells, including induced neural stem cells (iNSCs. Here, we show that mouse fibroblasts can be directly reprogrammed into midbrain dopaminergic neuronal progenitors (DPs by temporal expression of the pluripotency factors and environment containing sonic hedgehog and fibroblast growth factor 8. Within thirteen days, self-renewing and functional induced DPs (iDPs were generated. Interestingly, the inhibition of both Jak and Gsk3β notably enhanced the iDP reprogramming efficiency. We confirmed the functionality of the iDPs by showing that the dopaminergic neurons generated from iDPs express midbrain markers, release dopamine, and show typical electrophysiological profiles. Our results demonstrate that the pluripotency factors-mediated direct reprogramming is an invaluable strategy for supplying functional and proliferating iDPs and may be useful for other neural progenitors required for disease modeling and cell therapies for neurodegenerative disorders.

  19. Connexin 32 and connexin 43 are involved in lineage restriction of hepatic progenitor cells to hepatocytes

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    Haiyun Pei

    2017-11-01

    Full Text Available Abstract Background Bi-potential hepatic progenitor cells can give rise to both hepatocytes and cholangiocytes, which is the last phase and critical juncture in terms of sequentially hepatic lineage restriction from any kind of stem cells. If their differentiation can be controlled, it might access to functional hepatocytes to develop pharmaceutical and biotechnology industries as well as cell therapies for end-stage liver diseases. Methods In this study, we investigated the influence of Cx32 and Cx43 on hepatocyte differentiation of WB-F344 cells by in vitro gain and loss of function analyses. An inhibitor of Cx32 was also used to make further clarification. To reveal p38 MAPK pathway is closely related to Cxs, rats with 70% partial hepatectomy were injected intraperitoneally with a p38 inhibitor, SB203580. Besides, the effects of p38 MAPK pathway on differentiation of hepatoblasts isolated from fetal rat livers were evaluated by addition of SB203580 in culture medium. Results In vitro gain and loss of function analyses showed overexpression of Connexin 32 and knockdown of Connexin 43 promoted hepatocytes differentiation from hepatic progenitor cells. In addition, in vitro and ex vivo research revealed inhibition of p38 mitogen-activated protein kinase pathway can improve hepatocytes differentiation correlating with upregulation of Connexin 32 expression and downregulation of Connexin 43 expression. Conclusions Here we demonstrate that Connexins play crucial roles in facilitating differentiation of hepatic progenitors. Our work further implicates that regulators of Connexins and their related pathways might provide new insights to improve lineage restriction of stem cells to mature hepatocytes.

  20. Towards consistent generation of pancreatic lineage progenitors from human pluripotent stem cells.

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    Rostovskaya, Maria; Bredenkamp, Nicholas; Smith, Austin

    2015-10-19

    Human pluripotent stem cells can in principle be used as a source of any differentiated cell type for disease modelling, drug screening, toxicology testing or cell replacement therapy. Type I diabetes is considered a major target for stem cell applications due to the shortage of primary human beta cells. Several protocols have been reported for generating pancreatic progenitors by in vitro differentiation of human pluripotent stem cells. Here we first assessed one of these protocols on a panel of pluripotent stem cell lines for capacity to engender glucose sensitive insulin-producing cells after engraftment in immunocompromised mice. We observed variable outcomes with only one cell line showing a low level of glucose response. We, therefore, undertook a systematic comparison of different methods for inducing definitive endoderm and subsequently pancreatic differentiation. Of several protocols tested, we identified a combined approach that robustly generated pancreatic progenitors in vitro from both embryo-derived and induced pluripotent stem cells. These findings suggest that, although there are intrinsic differences in lineage specification propensity between pluripotent stem cell lines, optimal differentiation procedures may consistently direct a substantial fraction of cells into pancreatic specification. © 2015 The Authors.

  1. Generation of polyhormonal and multipotent pancreatic progenitor lineages from human pluripotent stem cells.

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    Korytnikov, Roman; Nostro, Maria Cristina

    2016-05-15

    Generation of pancreatic β-cells from human pluripotent stem cells (hPSCs) has enormous importance in type 1 diabetes (T1D), as it is fundamental to a treatment strategy based on cellular therapeutics. Being able to generate β-cells, as well as other mature pancreatic cells, from human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs) will also enable the development of platforms that can be used for disease modeling and drug testing for a variety of pancreas-associated diseases, including cystic fibrosis. For this to occur, it is crucial to develop differentiation strategies that are robust and reproducible across cell lines and laboratories. In this article we describe two serum-free differentiation protocols designed to generate specific pancreatic lineages from hPSCs. Our approach employs a variety of cytokines and small molecules to mimic developmental pathways active during pancreatic organogenesis and allows for the in vitro generation of distinct pancreatic populations. The first protocol is designed to give rise to polyhormonal cells that have the potential to differentiate into glucagon-producing cells. The second protocol is geared to generate multipotent pancreatic progenitor cells, which harbor the potential to generate all pancreatic lineages including: monohormonal endocrine cells, acinar, and ductal cells. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Distinct epigenomic landscapes of pluripotent and lineage-committed human cells.

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    Hawkins, R David; Hon, Gary C; Lee, Leonard K; Ngo, Queminh; Lister, Ryan; Pelizzola, Mattia; Edsall, Lee E; Kuan, Samantha; Luu, Ying; Klugman, Sarit; Antosiewicz-Bourget, Jessica; Ye, Zhen; Espinoza, Celso; Agarwahl, Saurabh; Shen, Li; Ruotti, Victor; Wang, Wei; Stewart, Ron; Thomson, James A; Ecker, Joseph R; Ren, Bing

    2010-05-07

    Human embryonic stem cells (hESCs) share an identical genome with lineage-committed cells, yet possess the remarkable properties of self-renewal and pluripotency. The diverse cellular properties in different cells have been attributed to their distinct epigenomes, but how much epigenomes differ remains unclear. Here, we report that epigenomic landscapes in hESCs and lineage-committed cells are drastically different. By comparing the chromatin-modification profiles and DNA methylomes in hESCs and primary fibroblasts, we find that nearly one-third of the genome differs in chromatin structure. Most changes arise from dramatic redistributions of repressive H3K9me3 and H3K27me3 marks, which form blocks that significantly expand in fibroblasts. A large number of potential regulatory sequences also exhibit a high degree of dynamics in chromatin modifications and DNA methylation. Additionally, we observe novel, context-dependent relationships between DNA methylation and chromatin modifications. Our results provide new insights into epigenetic mechanisms underlying properties of pluripotency and cell fate commitment.

  3. Induction of multipotential hematopoietic progenitors from human pluripotent stem cells via re-specification of lineage-restricted precursors

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    Doulatov, Sergei; Vo, Linda T.; Chou, Stephanie S.; Kim, Peter G.; Arora, Natasha; Li, Hu; Hadland, Brandon K.; Bernstein, Irwin D.; Collins, James J.; Zon, Leonard I.; Daley, George Q.

    2013-01-01

    Summary Human pluripotent stem cells (hPSCs) represent a promising source of patient-specific cells for disease modeling, drug screens, and cellular therapies. However, the inability to derive engraftable human hematopoietic stem and progenitor (HSPCs) has limited their characterization to in vitro assays. We report a strategy to re-specify lineage-restricted CD34+CD45+ myeloid precursors derived from hPSCs into multilineage progenitors that can be expanded in vitro and engraft in vivo. HOXA9, ERG, and RORA conferred self-renewal and multilineage potential in vitro and maintained primitive CD34+CD38− cells. Screening cells via transplantation revealed that two additional factors, SOX4 and MYB, were required for engraftment. Progenitors specified with all five factors gave rise to reproducible short-term engraftment with myeloid and erythroid lineages. Erythroid precursors underwent hemoglobin switching in vivo, silencing embryonic and activating adult globin expression. Our combinatorial screening approach establishes a strategy for obtaining transcription factor-mediated engraftment of blood progenitors from human pluripotent cells. PMID:24094326

  4. Mechanical modulation of nascent stem cell lineage commitment in tissue engineering scaffolds.

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    Song, Min Jae; Dean, David; Knothe Tate, Melissa L

    2013-07-01

    Taking inspiration from tissue morphogenesis in utero, this study tests the concept of using tissue engineering scaffolds as delivery devices to modulate emergent structure-function relationships at early stages of tissue genesis. We report on the use of a combined computational fluid dynamics (CFD) modeling, advanced manufacturing methods, and experimental fluid mechanics (micro-piv and strain mapping) for the prospective design of tissue engineering scaffold geometries that deliver spatially resolved mechanical cues to stem cells seeded within. When subjected to a constant magnitude global flow regime, the local scaffold geometry dictates the magnitudes of mechanical stresses and strains experienced by a given cell, and in a spatially resolved fashion, similar to patterning during morphogenesis. In addition, early markers of mesenchymal stem cell lineage commitment relate significantly to the local mechanical environment of the cell. Finally, by plotting the range of stress-strain states for all data corresponding to nascent cell lineage commitment (95% CI), we begin to "map the mechanome", defining stress-strain states most conducive to targeted cell fates. In sum, we provide a library of reference mechanical cues that can be delivered to cells seeded on tissue engineering scaffolds to guide target tissue phenotypes in a temporally and spatially resolved manner. Knowledge of these effects allows for prospective scaffold design optimization using virtual models prior to prototyping and clinical implementation. Finally, this approach enables the development of next generation scaffolds cum delivery devices for genesis of complex tissues with heterogenous properties, e.g., organs, joints or interface tissues such as growth plates. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. SHIP1-expressing mesenchymal stem cells regulate hematopoietic stem cell homeostasis and lineage commitment during aging.

    Science.gov (United States)

    Iyer, Sonia; Brooks, Robert; Gumbleton, Matthew; Kerr, William G

    2015-05-01

    Hematopoietic stem cell (HSC) self-renewal and lineage choice are subject to intrinsic control. However, this intrinsic regulation is also impacted by external cues provided by niche cells. There are multiple cellular components that participate in HSC support with the mesenchymal stem cell (MSC) playing a pivotal role. We had previously identified a role for SH2 domain-containing inositol 5'-phosphatase-1 (SHIP1) in HSC niche function through analysis of mice with germline or induced SHIP1 deficiency. In this study, we show that the HSC compartment expands significantly when aged in a niche that contains SHIP1-deficient MSC; however, this expanded HSC compartment exhibits a strong bias toward myeloid differentiation. In addition, we show that SHIP1 prevents chronic G-CSF production by the aging MSC compartment. These findings demonstrate that intracellular signaling by SHIP1 in MSC is critical for the control of HSC output and lineage commitment during aging. These studies increase our understanding of how myeloid bias occurs in aging and thus could have implications for the development of myeloproliferative disease in aging.

  6. Loss of C/EBP alpha cell cycle control increases myeloid progenitor proliferation and transforms the neutrophil granulocyte lineage

    DEFF Research Database (Denmark)

    Porse, Bo T; Bryder, David; Theilgaard-Mönch, Kim

    2005-01-01

    dissociate the ability of C/EBP alpha to block cell cycle progression through E2F inhibition from its function as a transcriptional activator impair the in vivo development of the neutrophil granulocyte and adipose lineages. We now show that such mutations increase the capacity of bone marrow (BM) myeloid...... progenitors to proliferate, and predispose mice to a granulocytic myeloproliferative disorder and transformation of the myeloid compartment of the BM. Both of these phenotypes were transplantable into lethally irradiated recipients. BM transformation was characterized by a block in granulocyte differentiation...

  7. In vitro cultured progenitors and precursors of cardiac cell lineages from human normal and post-ischemic hearts

    Directory of Open Access Journals (Sweden)

    F Di Meglio

    2009-08-01

    Full Text Available The demonstration of the presence of dividing primitive cells in damaged hearts has sparked increased interest about myocardium regenerative processes. We examined the rate and the differentiation of in vitro cultured resident cardiac primitive cells obtained from pathological and normal human hearts in order to evaluate the activation of progenitors and precursors of cardiac cell lineages in post-ischemic human hearts. The precursors and progenitors of cardiomyocyte, smooth muscle and endothelial lineage were identified by immunocytochemistry and the expression of characteristic markers was studied by western blot and RT-PCR. The amount of proteins characteristic for cardiac cells (a-SA and MHC, VEGFR-2 and FVIII, SMA for the precursors of cardiomyocytes, endothelial and smooth muscle cells, respectively inclines toward an increase in both a-SA and MHC. The increased levels of FVIII and VEGFR2 are statistically significant, suggesting an important re-activation of neoangiogenesis. At the same time, the augmented expression of mRNA for Nkx 2.5, the trascriptional factor for cardiomyocyte differentiation, confirms the persistence of differentiative processes in terminally injured hearts. Our study would appear to confirm the activation of human heart regeneration potential in pathological conditions and the ability of its primitive cells to maintain their proliferative capability in vitro. The cardiac cell isolation method we used could be useful in the future for studying modifications to the microenvironment that positively influence cardiac primitive cell differentiation or inhibit, or retard, the pathological remodeling and functional degradation of the heart.

  8. Epigenetic Reprogramming of Lineage-Committed Human Mammary Epithelial Cells Requires DNMT3A and Loss of DOT1L

    Directory of Open Access Journals (Sweden)

    Jerrica L. Breindel

    2017-09-01

    Full Text Available Organogenesis and tissue development occur through sequential stepwise processes leading to increased lineage restriction and loss of pluripotency. An exception to this appears in the adult human breast, where rare variant epithelial cells exhibit pluripotency and multilineage differentiation potential when removed from the signals of their native microenvironment. This phenomenon provides a unique opportunity to study mechanisms that lead to cellular reprogramming and lineage plasticity in real time. Here, we show that primary human mammary epithelial cells (HMECs lose expression of differentiated mammary epithelial markers in a manner dependent on paracrine factors and epigenetic regulation. Furthermore, we demonstrate that HMEC reprogramming is dependent on gene silencing by the DNA methyltransferase DNMT3A and loss of histone transcriptional marks following downregulation of the methyltransferase DOT1L. These results demonstrate that lineage commitment in adult tissues is context dependent and highlight the plasticity of somatic cells when removed from their native tissue microenvironment.

  9. Trophic factors from adipose tissue-derived multi-lineage progenitor cells promote cytodifferentiation of periodontal ligament cells

    Energy Technology Data Exchange (ETDEWEB)

    Sawada, Keigo [Department of Periodontology, Osaka University Graduate School of Dentistry, Osaka (Japan); Takedachi, Masahide, E-mail: takedati@dent.osaka-u.ac.jp [Department of Periodontology, Osaka University Graduate School of Dentistry, Osaka (Japan); Yamamoto, Satomi; Morimoto, Chiaki; Ozasa, Masao; Iwayama, Tomoaki [Department of Periodontology, Osaka University Graduate School of Dentistry, Osaka (Japan); Lee, Chun Man [Medical Center for Translational Research, Osaka University Hospital, Osaka (Japan); Okura, Hanayuki; Matsuyama, Akifumi [Research on Disease Bioresources, Platform of Therapeutics for Rare Disease, National Institute of Biomedical Innovation, Osaka (Japan); Kitamura, Masahiro; Murakami, Shinya [Department of Periodontology, Osaka University Graduate School of Dentistry, Osaka (Japan)

    2015-08-14

    Stem and progenitor cells are currently being investigated for their applicability in cell-based therapy for periodontal tissue regeneration. We recently demonstrated that the transplantation of adipose tissue-derived multi-lineage progenitor cells (ADMPCs) enhances periodontal tissue regeneration in beagle dogs. However, the molecular mechanisms by which transplanted ADMPCs induce periodontal tissue regeneration remain to be elucidated. In this study, trophic factors released by ADMPCs were examined for their paracrine effects on human periodontal ligament cell (HPDL) function. ADMPC conditioned medium (ADMPC-CM) up-regulated osteoblastic gene expression, alkaline phosphatase activity and calcified nodule formation in HPDLs, but did not significantly affect their proliferative response. ADMPCs secreted a number of growth factors, including insulin-like growth factor binding protein 6 (IGFBP6), hepatocyte growth factor and vascular endothelial growth factor. Among these, IGFBP6 was most highly expressed. Interestingly, the positive effects of ADMPC-CM on HPDL differentiation were significantly suppressed by transfecting ADMPCs with IGFBP6 siRNA. Our results suggest that ADMPCs transplanted into a defect in periodontal tissue release trophic factors that can stimulate the differentiation of HPDLs to mineralized tissue-forming cells, such as osteoblasts and cementoblasts. IGFBP6 may play crucial roles in ADMPC-induced periodontal regeneration. - Highlights: • ADMPC-derived humoral factors stimulate cytodifferentiation of HPDLs. • ADMPCs secret growth factors including IGFBP6, VEGF and HGF. • IGFBP6 is involved in the promotion effect of ADMPC-CM on HPDL cytodifferentiation.

  10. Trophic factors from adipose tissue-derived multi-lineage progenitor cells promote cytodifferentiation of periodontal ligament cells

    International Nuclear Information System (INIS)

    Sawada, Keigo; Takedachi, Masahide; Yamamoto, Satomi; Morimoto, Chiaki; Ozasa, Masao; Iwayama, Tomoaki; Lee, Chun Man; Okura, Hanayuki; Matsuyama, Akifumi; Kitamura, Masahiro; Murakami, Shinya

    2015-01-01

    Stem and progenitor cells are currently being investigated for their applicability in cell-based therapy for periodontal tissue regeneration. We recently demonstrated that the transplantation of adipose tissue-derived multi-lineage progenitor cells (ADMPCs) enhances periodontal tissue regeneration in beagle dogs. However, the molecular mechanisms by which transplanted ADMPCs induce periodontal tissue regeneration remain to be elucidated. In this study, trophic factors released by ADMPCs were examined for their paracrine effects on human periodontal ligament cell (HPDL) function. ADMPC conditioned medium (ADMPC-CM) up-regulated osteoblastic gene expression, alkaline phosphatase activity and calcified nodule formation in HPDLs, but did not significantly affect their proliferative response. ADMPCs secreted a number of growth factors, including insulin-like growth factor binding protein 6 (IGFBP6), hepatocyte growth factor and vascular endothelial growth factor. Among these, IGFBP6 was most highly expressed. Interestingly, the positive effects of ADMPC-CM on HPDL differentiation were significantly suppressed by transfecting ADMPCs with IGFBP6 siRNA. Our results suggest that ADMPCs transplanted into a defect in periodontal tissue release trophic factors that can stimulate the differentiation of HPDLs to mineralized tissue-forming cells, such as osteoblasts and cementoblasts. IGFBP6 may play crucial roles in ADMPC-induced periodontal regeneration. - Highlights: • ADMPC-derived humoral factors stimulate cytodifferentiation of HPDLs. • ADMPCs secret growth factors including IGFBP6, VEGF and HGF. • IGFBP6 is involved in the promotion effect of ADMPC-CM on HPDL cytodifferentiation

  11. In Vivo Clonal Analysis Reveals Lineage-Restricted Progenitor Characteristics in Mammalian Kidney Development, Maintenance, and Regeneration

    Directory of Open Access Journals (Sweden)

    Yuval Rinkevich

    2014-05-01

    Full Text Available The mechanism and magnitude by which the mammalian kidney generates and maintains its proximal tubules, distal tubules, and collecting ducts remain controversial. Here, we use long-term in vivo genetic lineage tracing and clonal analysis of individual cells from kidneys undergoing development, maintenance, and regeneration. We show that the adult mammalian kidney undergoes continuous tubulogenesis via expansions of fate-restricted clones. Kidneys recovering from damage undergo tubulogenesis through expansions of clones with segment-specific borders, and renal spheres developing in vitro from individual cells maintain distinct, segment-specific fates. Analysis of mice derived by transfer of color-marked embryonic stem cells (ESCs into uncolored blastocysts demonstrates that nephrons are polyclonal, developing from expansions of singly fated clones. Finally, we show that adult renal clones are derived from Wnt-responsive precursors, and their tracing in vivo generates tubules that are segment specific. Collectively, these analyses demonstrate that fate-restricted precursors functioning as unipotent progenitors continuously maintain and self-preserve the mouse kidney throughout life.

  12. The TCR ligand-inducible expression of CD73 marks γδ lineage commitment and a metastable intermediate in effector specification

    DEFF Research Database (Denmark)

    Coffey, Francis; Lee, Sang-Yun; Buus, Terkild B

    2014-01-01

    Numerous studies indicate that γδ T cell receptor (γδTCR) expression alone does not reliably mark commitment of early thymic progenitors to the γδ fate. This raises the possibility that the γδTCR is unable to intrinsically specify fate and instead requires additional environmental factors, includ...

  13. Pathologic Stimulus Determines Lineage Commitment of Cardiac C-kit+ Cells.

    Science.gov (United States)

    Chen, Zhongming; Zhu, Wuqiang; Bender, Ingrid; Gong, Wuming; Kwak, Il-Youp; Yellamilli, Amritha; Hodges, Thomas J; Nemoto, Natsumi; Zhang, Jianyi; Garry, Daniel J; van Berlo, Jop H

    2017-12-12

    Although cardiac c-kit + cells are being tested in clinical trials, the circumstances that determine lineage differentiation of c-kit + cells in vivo are unknown. Recent findings suggest that endogenous cardiac c-kit + cells rarely contribute cardiomyocytes to the adult heart. We assessed whether various pathological stimuli differentially affect the eventual cell fates of c-kit + cells. We used single-cell sequencing and genetic lineage tracing of c-kit + cells to determine whether various pathological stimuli would result in different fates of c-kit + cells. Single-cell sequencing of cardiac CD45 - c-kit + cells showed innate heterogeneity, indicative of the existence of vascular and mesenchymal c-kit + cells in normal hearts. Cardiac pressure overload resulted in a modest increase in c-kit-derived cardiomyocytes, with significant increases in the numbers of endothelial cells and fibroblasts. Doxorubicin-induced acute cardiotoxicity did not increase c-kit-derived endothelial cell fates but instead induced cardiomyocyte differentiation. Mechanistically, doxorubicin-induced DNA damage in c-kit + cells resulted in expression of p53. Inhibition of p53 blocked cardiomyocyte differentiation in response to doxorubicin, whereas stabilization of p53 was sufficient to increase c-kit-derived cardiomyocyte differentiation. These results demonstrate that different pathological stimuli induce different cell fates of c-kit + cells in vivo. Although the overall rate of cardiomyocyte formation from c-kit + cells is still below clinically relevant levels, we show that p53 is central to the ability of c-kit + cells to adopt cardiomyocyte fates, which could lead to the development of strategies to preferentially generate cardiomyocytes from c-kit + cells. © 2017 American Heart Association, Inc.

  14. Mast cell repopulation of the peritoneal cavity: contribution of mast cell progenitors versus bone marrow derived committed mast cell precursors

    Directory of Open Access Journals (Sweden)

    Pastor Maria

    2010-06-01

    Full Text Available Abstract Background Mast cells have recently gained new importance as immunoregulatory cells that are involved in numerous pathological processes. One result of these processes is an increase in mast cell numbers at peripheral sites. This study was undertaken to determine the mast cell response in the peritoneal cavity and bone marrow during repopulation of the peritoneal cavity in rats. Results Two mast cell specific antibodies, mAb AA4 and mAb BGD6, were used to distinguish the committed mast cell precursor from more mature mast cells. The peritoneal cavity was depleted of mast cells using distilled water. Twelve hours after distilled water injection, very immature mast cells could be isolated from the blood and by 48 hours were present in the peritoneal cavity. At this same time the percentage of mast cells in mitosis increased fourfold. Mast cell depletion of the peritoneal cavity also reduced the total number of mast cells in the bone marrow, but increased the number of mast cell committed precursors. Conclusions In response to mast cell depletion of the peritoneal cavity, a mast cell progenitor is released into the circulation and participates in repopulation of the peritoneal cavity, while the committed mast cell precursor is retained in the bone marrow.

  15. Nano-hydroxyapatite modulates osteoblast lineage commitment by stimulation of DNA methylation and regulation of gene expression

    Science.gov (United States)

    Ha, Shin-Woo; Jang, Hae Lin; Nam, Ki Tae; Beck, George R.

    2015-01-01

    Hydroxyapatite (HA) is the primary structural component of the skeleton and dentition. Under biological conditions, HA does not occur spontaneously and therefore must be actively synthesized by mineralizing cells such as osteoblasts. The mechanism(s) by which HA is actively synthesized by cells and deposited to create a mineralized matrix are not fully understood and the consequences of mineralization on cell function are even less well understood. HA can be chemically synthesized (HAp) and is therefore currently being investigated as a promising therapeutic biomaterial for use as a functional scaffold and implant coating for skeletal repair and dental applications. Here we investigated the biological effects of nano-HAp (10×100 nm) on the lineage commitment and differentiation of bone forming osteoblasts. Exposure of early stage differentiating osteoblasts resulted in dramatic and sustained changes in gene expression, both increased and decreased, whereas later stage osteoblasts were much less responsive. Analysis of the promoter region one of the most responsive genes, alkaline phosphatase, identified the stimulation of DNA methylation following cell exposure to nano-HAp. Collectively, the results reveal the novel epigenetic regulation of cell function by nano-HAp which has significant implication on lineage determination as well as identifying a novel potential therapeutic use of nanomaterials. PMID:26141836

  16. Activation of GSK3β by Sirt2 is required for early lineage commitment of mouse embryonic stem cell.

    Directory of Open Access Journals (Sweden)

    Xiaoxing Si

    Full Text Available Sirt2, a member of the NAD(+-dependent protein deacetylase family, is increasingly recognized as a critical regulator of the cell cycle, cellular necrosis and cytoskeleton organization. However, its role in embryonic stem cells (ESCs remains unclear. Here we demonstrate that Sirt2 is up-regulated during RA (retinoic acid-induced and embryoid body (EB differentiation of mouse ESCs. Using lentivirus-mediated shRNA methods, we found that knockdown of Sirt2 compromises the differentiation of mouse ESCs into ectoderm while promoting mesoderm and endoderm differentiation. Knockdown of Sirt2 expression also leads to the activation of GSK3β through decreased phosphorylation of the serine at position 9 (Ser9 but not tyrosine at position 216 (Tyr216. Moreover, the constitutive activation of GSK3β during EB differentiation mimics the effect of Sirt2 knockdown, while down-regulation of GSK3β rescues the effect of Sirt2 knockdown on differentiation. In contrast to the effect on lineage differentiation, Sirt2 knockdown and GSK3β up-regulation do not change the self-renewal state of mouse ESCs. Overall, our report reveals a new function for Sirt2 in regulating the proper lineage commitment of mouse ESCs.

  17. ERK2 suppresses self-renewal capacity of embryonic stem cells, but is not required for multi-lineage commitment.

    Directory of Open Access Journals (Sweden)

    William B Hamilton

    Full Text Available Activation of the FGF-ERK pathway is necessary for naïve mouse embryonic stem (ES cells to exit self-renewal and commit to early differentiated lineages. Here we show that genetic ablation of Erk2, the predominant ERK isozyme expressed in ES cells, results in hyper-phosphorylation of ERK1, but an overall decrease in total ERK activity as judged by substrate phosphorylation and immediate-early gene (IEG induction. Normal induction of this subset of canonical ERK targets, as well as p90RSK phosphorylation, was rescued by transgenic expression of either ERK1 or ERK2 indicating a degree of functional redundancy. In contrast to previously published work, Erk2-null ES cells exhibited no detectable defect in lineage specification to any of the three germ layers when induced to differentiate in either embryoid bodies or in defined neural induction conditions. However, under self-renewing conditions Erk2-null ES cells express increased levels of the pluripotency-associated transcripts, Nanog and Tbx3, a decrease in Nanog-GFP heterogeneity, and exhibit enhanced self-renewal in colony forming assays. Transgenic add-back of ERK2 is capable of restoring normal pluripotent gene expression and self-renewal capacity. We show that ERK2 contributes to the destabilization of ES cell self-renewal by reducing expression of pluripotency genes, such as Nanog, but is not specifically required for the early stages of germ layer specification.

  18. Architectural protein subclasses shape 3-D organization of genomes during lineage commitment

    Science.gov (United States)

    Phillips-Cremins, Jennifer E.; Sauria, Michael E. G.; Sanyal, Amartya; Gerasimova, Tatiana I.; Lajoie, Bryan R.; Bell, Joshua S. K.; Ong, Chin-Tong; Hookway, Tracy A.; Guo, Changying; Sun, Yuhua; Bland, Michael J.; Wagstaff, William; Dalton, Stephen; McDevitt, Todd C.; Sen, Ranjan; Dekker, Job; Taylor, James; Corces, Victor G.

    2013-01-01

    Summary Understanding the topological configurations of chromatin may reveal valuable insights into how the genome and epigenome act in concert to control cell fate during development. Here we generate high-resolution architecture maps across seven genomic loci in embryonic stem cells and neural progenitor cells. We observe a hierarchy of 3-D interactions that undergo marked reorganization at the sub-Mb scale during differentiation. Distinct combinations of CTCF, Mediator, and cohesin show widespread enrichment in looping interactions at different length scales. CTCF/cohesin anchor long-range constitutive interactions that form the topological basis for invariant sub-domains. Conversely, Mediator/cohesin together with pioneer factors bridge shortrange enhancer-promoter interactions within and between larger sub-domains. Knockdown of Smc1 or Med12 in ES cells results in disruption of spatial architecture and down-regulation of genes found in cohesin-mediated interactions. We conclude that cell type-specific chromatin organization occurs at the sub-Mb scale and that architectural proteins shape the genome in hierarchical length scales. PMID:23706625

  19. Precommitment low-level Neurog3 expression defines a long-lived mitotic endocrine-biased progenitor pool that drives production of endocrine-committed cells

    Science.gov (United States)

    Bechard, Matthew E.; Bankaitis, Eric D.; Hipkens, Susan B.; Ustione, Alessandro; Piston, David W.; Yang, Yu-Ping; Magnuson, Mark A.; Wright, Christopher V.E.

    2016-01-01

    The current model for endocrine cell specification in the pancreas invokes high-level production of the transcription factor Neurogenin 3 (Neurog3) in Sox9+ bipotent epithelial cells as the trigger for endocrine commitment, cell cycle exit, and rapid delamination toward proto-islet clusters. This model posits a transient Neurog3 expression state and short epithelial residence period. We show, however, that a Neurog3TA.LO cell population, defined as Neurog3 transcriptionally active and Sox9+ and often containing nonimmunodetectable Neurog3 protein, has a relatively high mitotic index and prolonged epithelial residency. We propose that this endocrine-biased mitotic progenitor state is functionally separated from a pro-ductal pool and endows them with long-term capacity to make endocrine fate-directed progeny. A novel BAC transgenic Neurog3 reporter detected two types of mitotic behavior in Sox9+ Neurog3TA.LO progenitors, associated with progenitor pool maintenance or derivation of endocrine-committed Neurog3HI cells, respectively. Moreover, limiting Neurog3 expression dramatically increased the proportional representation of Sox9+ Neurog3TA.LO progenitors, with a doubling of its mitotic index relative to normal Neurog3 expression, suggesting that low Neurog3 expression is a defining feature of this cycling endocrine-biased state. We propose that Sox9+ Neurog3TA.LO endocrine-biased progenitors feed production of Neurog3HI endocrine-committed cells during pancreas organogenesis. PMID:27585590

  20. Fourier transform infrared microspectroscopy identifies early lineage commitment in differentiating human embryonic stem cells.

    Science.gov (United States)

    Heraud, Philip; Ng, Elizabeth S; Caine, Sally; Yu, Qing C; Hirst, Claire; Mayberry, Robyn; Bruce, Amanda; Wood, Bayden R; McNaughton, Don; Stanley, Edouard G; Elefanty, Andrew G

    2010-03-01

    Human ESCs (hESCs) are a valuable tool for the study of early human development and represent a source of normal differentiated cells for pharmaceutical and biotechnology applications and ultimately for cell replacement therapies. For all applications, it will be necessary to develop assays to validate the efficacy of hESC differentiation. We explored the capacity for FTIR spectroscopy, a technique that rapidly characterises cellular macromolecular composition, to discriminate mesendoderm or ectoderm committed cells from undifferentiated hESCs. Distinct infrared spectroscopic "signatures" readily distinguished hESCs from these early differentiated progeny, with bioinformatic models able to correctly classify over 97% of spectra. These data identify a role for FTIR spectroscopy as a new modality to complement conventional analyses of hESCs and their derivatives. FTIR spectroscopy has the potential to provide low-cost, automatable measurements for the quality control of stem and differentiated cells to be used in industry and regenerative medicine. Crown Copyright 2009. Published by Elsevier B.V. All rights reserved.

  1. Pax6 downregulation mediates abnormal lineage commitment of the ocular surface epithelium in aqueous-deficient dry eye disease.

    Directory of Open Access Journals (Sweden)

    Ying Ting Chen

    Full Text Available Keratinizing squamous metaplasia (SQM of the ocular surface is a blinding consequence of systemic autoimmune disease and there is no cure. Ocular SQM is traditionally viewed as an adaptive tissue response during chronic keratoconjunctivitis sicca (KCS that provokes pathological keratinization of the corneal epithelium and fibrosis of the corneal stroma. Recently, we established the autoimmune regulator-knockout (Aire KO mouse as a model of autoimmune KCS and identified an essential role for autoreactive CD4+ T cells in SQM pathogenesis. In subsequent studies, we noted the down-regulation of paired box gene 6 (Pax6 in both human patients with chronic KCS associated with Sjögren's syndrome and Aire KO mice. Pax6 encodes a pleiotropic transcription factor guiding eye morphogenesis during development. While the postnatal function of Pax6 is largely unknown, we hypothesized that its role in maintaining ocular surface homeostasis was disrupted in the inflamed eye and that loss of Pax6 played a functional role in the initiation and progression of SQM. Adoptive transfer of autoreactive T cells from Aire KO mice to immunodeficient recipients confirmed CD4+ T cells as the principal downstream effectors promoting Pax6 downregulation in Aire KO mice. CD4+ T cells required local signaling via Interleukin-1 receptor (IL-1R1 to provoke Pax6 loss, which prompted a switch from corneal-specific cytokeratin, CK12, to epidermal-specific CK10. The functional role of Pax6 loss in SQM pathogenesis was indicated by the reversal of SQM and restoration of ocular surface homeostasis following forced expression of Pax6 in corneal epithelial cells using adenovirus. Thus, tissue-restricted restoration of Pax6 prevented aberrant epidermal-lineage commitment suggesting adjuvant Pax6 gene therapy may represent a novel therapeutic approach to prevent SQM in patients with chronic inflammatory diseases of the ocular surface.

  2. Ascorbic acid alters cell fate commitment of human neural progenitors in a WNT/β-catenin/ROS signaling dependent manner.

    Science.gov (United States)

    Rharass, Tareck; Lantow, Margareta; Gbankoto, Adam; Weiss, Dieter G; Panáková, Daniela; Lucas, Stéphanie

    2017-10-16

    Improving the neuronal yield from in vitro cultivated neural progenitor cells (NPCs) is an essential challenge in transplantation therapy in neurological disorders. In this regard, Ascorbic acid (AA) is widely used to expand neurogenesis from NPCs in cultures although the mechanisms of its action remain unclear. Neurogenesis from NPCs is regulated by the redox-sensitive WNT/β-catenin signaling pathway. We therefore aimed to investigate how AA interacts with this pathway and potentiates neurogenesis. Effects of 200 μM AA were compared with the pro-neurogenic reagent and WNT/β-catenin signaling agonist lithium chloride (LiCl), and molecules with antioxidant activities i.e. N-acetyl-L-cysteine (NAC) and ruthenium red (RuR), in differentiating neural progenitor ReNcell VM cells. Cells were supplemented with reagents for two periods of treatment: a full period encompassing the whole differentiation process versus an early short period that is restricted to the cell fate commitment stage. Intracellular redox balance and reactive oxygen species (ROS) metabolism were examined by flow cytometry using redox and ROS sensors. Confocal microscopy was performed to assess cell viability, neuronal yield, and levels of two proteins: Nucleoredoxin (NXN) and the WNT/β-catenin signaling component Dishevelled 2 (DVL2). TUBB3 and MYC gene responses were evaluated by quantitative real-time PCR. DVL2-NXN complex dissociation was measured by fluorescence resonance energy transfer (FRET). In contrast to NAC which predictably exhibited an antioxidant effect, AA treatment enhanced ROS metabolism with no cytotoxic induction. Both drugs altered ROS levels only at the early stage of the differentiation as no changes were held beyond the neuronal fate commitment stage. FRET studies showed that AA treatment accelerated the redox-dependent release of the initial pool of DVL2 from its sequestration by NXN, while RuR treatment hampered the dissociation of the two proteins. Accordingly, AA

  3. High-content image informatics of the structural nuclear protein NuMA parses trajectories for stem/progenitor cell lineages and oncogenic transformation

    Energy Technology Data Exchange (ETDEWEB)

    Vega, Sebastián L. [Department of Chemical and Biochemical Engineering, Rutgers University, Piscataway, NJ (United States); Liu, Er; Arvind, Varun [Department of Biomedical Engineering, Rutgers University, Piscataway, NJ (United States); Bushman, Jared [Department of Chemistry and Chemical Biology, New Jersey Center for Biomaterials, Piscataway, NJ (United States); School of Pharmacy, University of Wyoming, Laramie, WY (United States); Sung, Hak-Joon [Department of Chemistry and Chemical Biology, New Jersey Center for Biomaterials, Piscataway, NJ (United States); Department of Biomedical Engineering, Vanderbilt University, Nashville, TN (United States); Becker, Matthew L. [Department of Polymer Science and Engineering, University of Akron, Akron, OH (United States); Lelièvre, Sophie [Department of Basic Medical Sciences, Purdue University, West Lafayette, IN (United States); Kohn, Joachim [Department of Chemistry and Chemical Biology, New Jersey Center for Biomaterials, Piscataway, NJ (United States); Vidi, Pierre-Alexandre, E-mail: pvidi@wakehealth.edu [Department of Cancer Biology, Wake Forest School of Medicine, Winston-Salem, NC (United States); Moghe, Prabhas V., E-mail: moghe@rutgers.edu [Department of Chemical and Biochemical Engineering, Rutgers University, Piscataway, NJ (United States); Department of Biomedical Engineering, Rutgers University, Piscataway, NJ (United States)

    2017-02-01

    Stem and progenitor cells that exhibit significant regenerative potential and critical roles in cancer initiation and progression remain difficult to characterize. Cell fates are determined by reciprocal signaling between the cell microenvironment and the nucleus; hence parameters derived from nuclear remodeling are ideal candidates for stem/progenitor cell characterization. Here we applied high-content, single cell analysis of nuclear shape and organization to examine stem and progenitor cells destined to distinct differentiation endpoints, yet undistinguishable by conventional methods. Nuclear descriptors defined through image informatics classified mesenchymal stem cells poised to either adipogenic or osteogenic differentiation, and oligodendrocyte precursors isolated from different regions of the brain and destined to distinct astrocyte subtypes. Nuclear descriptors also revealed early changes in stem cells after chemical oncogenesis, allowing the identification of a class of cancer-mitigating biomaterials. To capture the metrology of nuclear changes, we developed a simple and quantitative “imaging-derived” parsing index, which reflects the dynamic evolution of the high-dimensional space of nuclear organizational features. A comparative analysis of parsing outcomes via either nuclear shape or textural metrics of the nuclear structural protein NuMA indicates the nuclear shape alone is a weak phenotypic predictor. In contrast, variations in the NuMA organization parsed emergent cell phenotypes and discerned emergent stages of stem cell transformation, supporting a prognosticating role for this protein in the outcomes of nuclear functions. - Highlights: • High-content analysis of nuclear shape and organization classify stem and progenitor cells poised for distinct lineages. • Early oncogenic changes in mesenchymal stem cells (MSCs) are also detected with nuclear descriptors. • A new class of cancer-mitigating biomaterials was identified based on image

  4. High-content image informatics of the structural nuclear protein NuMA parses trajectories for stem/progenitor cell lineages and oncogenic transformation

    International Nuclear Information System (INIS)

    Vega, Sebastián L.; Liu, Er; Arvind, Varun; Bushman, Jared; Sung, Hak-Joon; Becker, Matthew L.; Lelièvre, Sophie; Kohn, Joachim; Vidi, Pierre-Alexandre; Moghe, Prabhas V.

    2017-01-01

    Stem and progenitor cells that exhibit significant regenerative potential and critical roles in cancer initiation and progression remain difficult to characterize. Cell fates are determined by reciprocal signaling between the cell microenvironment and the nucleus; hence parameters derived from nuclear remodeling are ideal candidates for stem/progenitor cell characterization. Here we applied high-content, single cell analysis of nuclear shape and organization to examine stem and progenitor cells destined to distinct differentiation endpoints, yet undistinguishable by conventional methods. Nuclear descriptors defined through image informatics classified mesenchymal stem cells poised to either adipogenic or osteogenic differentiation, and oligodendrocyte precursors isolated from different regions of the brain and destined to distinct astrocyte subtypes. Nuclear descriptors also revealed early changes in stem cells after chemical oncogenesis, allowing the identification of a class of cancer-mitigating biomaterials. To capture the metrology of nuclear changes, we developed a simple and quantitative “imaging-derived” parsing index, which reflects the dynamic evolution of the high-dimensional space of nuclear organizational features. A comparative analysis of parsing outcomes via either nuclear shape or textural metrics of the nuclear structural protein NuMA indicates the nuclear shape alone is a weak phenotypic predictor. In contrast, variations in the NuMA organization parsed emergent cell phenotypes and discerned emergent stages of stem cell transformation, supporting a prognosticating role for this protein in the outcomes of nuclear functions. - Highlights: • High-content analysis of nuclear shape and organization classify stem and progenitor cells poised for distinct lineages. • Early oncogenic changes in mesenchymal stem cells (MSCs) are also detected with nuclear descriptors. • A new class of cancer-mitigating biomaterials was identified based on image

  5. In vivo clonal analysis reveals lineage-restricted progenitor characteristics in mammalian kidney development, maintenance, and regeneration

    NARCIS (Netherlands)

    Rinkevich, Y.; Montoro, D.T.; Contreras-Trujillo, H.; Harari-Steinberg, O.; Newman, A.M.; Tsai, J.M.; Lim, X.; van Amerongen, R.; Bowman, A.; Januszyk, M.; Pleniceanu, O.; Nusse, R.; Longaker, M.T.; Weissman, I.L.; Dekel, B.

    2014-01-01

    The mechanism and magnitude by which the mammalian kidney generates and maintains its proximal tubules, distal tubules, and collecting ducts remain controversial. Here, we use long-term in vivo genetic lineage tracing and clonal analysis of individual cells from kidneys undergoing development,

  6. What happens in the thymus does not stay in the thymus: how T cells recycle the CD4+-CD8+ lineage commitment transcriptional circuitry to control their function

    Science.gov (United States)

    Vacchio, Melanie S.; Bosselut, Rémy

    2016-01-01

    MHC-restricted CD4+ and CD8+ T cell are at the core of most adaptive immune responses. Although these cells carry distinct functions, they arise from a common precursor during thymic differentiation, in a developmental sequence that matches CD4 and CD8 expression and functional potential with MHC restriction. While the transcriptional control of CD4+-CD8+ lineage choice in the thymus is now better understood, less was known about what maintains the CD4+- and CD8+-lineage integrity of mature T cells. In this review, we discuss the mechanisms that establish in the thymus, and maintain in post-thymic cells, the separation of these lineages. We focus on recent studies that address the mechanisms of epigenetic control of Cd4 expression and emphasize how maintaining a transcriptional circuitry nucleated around Thpok and Runx proteins, the key architects of CD4+-CD8+ lineage commitment in the thymus, is critical for CD4+ T cell helper functions. PMID:27260768

  7. Oscillatory fluid flow induces the osteogenic lineage commitment of mesenchymal stem cells: The effect of shear stress magnitude, frequency, and duration.

    Science.gov (United States)

    Stavenschi, Elena; Labour, Marie-Noelle; Hoey, David A

    2017-04-11

    A potent regulator of bone anabolism is physical loading. However, it is currently unclear whether physical stimuli such as fluid shear within the marrow cavity is sufficient to directly drive the osteogenic lineage commitment of resident mesenchymal stem cells (MSC). Therefore, the objective of the study is to employ a systematic analysis of oscillatory fluid flow (OFF) parameters predicted to occur in vivo on early MSC osteogenic responses and late stage lineage commitment. MSCs were exposed to OFF of 1Pa, 2Pa and 5Pa magnitudes at frequencies of 0.5Hz, 1Hz and 2Hz for 1h, 2h and 4h of stimulation. Our findings demonstrate that OFF elicits a positive osteogenic response in MSCs in a shear stress magnitude, frequency, and duration dependent manner that is gene specific. Based on the mRNA expression of osteogenic markers Cox2, Runx2 and Opn after short-term fluid flow stimulation, we identified that a regime of 2Pa shear magnitude and 2Hz frequency induces the most robust and reliable upregulation in osteogenic gene expression. Furthermore, long-term mechanical stimulation utilising this regime, elicits a significant increase in collagen and mineral deposition when compared to static control demonstrating that mechanical stimuli predicted within the marrow is sufficient to directly drive osteogenesis. Copyright © 2017. Published by Elsevier Ltd.

  8. Rat bone marrow progenitor cells transduced in situ by rSV40 vectors differentiate into multiple central nervous system cell lineages.

    Science.gov (United States)

    Louboutin, Jean-Pierre; Liu, Bianling; Reyes, Beverly A S; Van Bockstaele, Elisabeth J; Strayer, David S

    2006-12-01

    Using bone marrow-directed gene transfer, we tested whether bone marrow-derived cells may function as progenitors of central nervous system (CNS) cells in adult animals. SV40-derived gene delivery vectors were injected directly into femoral bone marrow, and we examined transgene expression in blood and brain for 0-16 months thereafter by immunostaining for FLAG epitope marker. An average of 5% of peripheral blood cells and 25% of femoral marrow cells were FLAG(+) throughout the study. CNS FLAG-expressing cells were mainly detected in the dentate gyrus (DG) and periventricular subependymal zone (PSZ). Although absent before 1 month and rare at 4 months, DG and PSZ FLAG(+) cells were abundant 16 months after bone marrow injection. Approximately 5% of DG cells expressed FLAG, including neurons (48.6%) and microglia (49.7%), and occasional astrocytes (1.6%), as determined by double immunostaining for FLAG and lineage markers. These data suggest that one or more populations of cells resident within adult bone marrow can migrate to the brain and differentiate into CNS-specific cells.

  9. Macrophages commit postnatal endothelium-derived progenitors to angiogenesis and restrict endothelial to mesenchymal transition during muscle regeneration.

    Science.gov (United States)

    Zordan, P; Rigamonti, E; Freudenberg, K; Conti, V; Azzoni, E; Rovere-Querini, P; Brunelli, S

    2014-01-30

    The damage of the skeletal muscle prompts a complex and coordinated response that involves the interactions of many different cell populations and promotes inflammation, vascular remodeling and finally muscle regeneration. Muscle disorders exist in which the irreversible loss of tissue integrity and function is linked to defective neo-angiogenesis with persistence of tissue necrosis and inflammation. Here we show that macrophages (MPs) are necessary for efficient vascular remodeling in the injured muscle. In particular, MPs sustain the differentiation of endothelial-derived progenitors to contribute to neo-capillary formation, by secreting pro-angiogenic growth factors. When phagocyte infiltration is compromised endothelial-derived progenitors undergo a significant endothelial to mesenchymal transition (EndoMT), possibly triggered by the activation of transforming growth factor-β/bone morphogenetic protein signaling, collagen accumulates and the muscle is replaced by fibrotic tissue. Our findings provide new insights in EndoMT in the adult skeletal muscle, and suggest that endothelial cells in the skeletal muscle may represent a new target for therapeutic intervention in fibrotic diseases.

  10. Progenitor Epithelium

    Science.gov (United States)

    Marty-Santos, Leilani

    2015-01-01

    Insulin-producing β cells within the vertebrate fetal pancreas acquire their fate in a step-wise manner. Whereas the intrinsic factors dictating the transcriptional or epigenetic status of pancreatic lineages have been intensely examined, less is known about cell–cell interactions that might constitute a niche for the developing β cell lineage. It is becoming increasingly clear that understanding and recapitulating these steps may instruct in vitro differentiation of embryonic stem cells and/or therapeutic regeneration. Indeed, directed differentiation techniques have improved since transitioning from 2D to 3D cultures, suggesting that the 3D microenvironment in which β cells are born is critical. However, to date, it remains unknown whether the changing architecture of the pancreatic epithelium impacts the fate of cells therein. An emerging challenge in the field is to elucidate how progenitors are allocated during key events, such as the stratification and subsequent resolution of the pre-pancreatic epithelium, as well as the formation of lumens and branches. Here, we assess the progenitor epithelium and examine how it might influence the emergence of pancreatic multipotent progenitors (MPCs), which give rise to β cells and other pancreatic lineages. PMID:26216134

  11. Nestin-positive mesenchymal stem cells favour the astroglial lineage in neural progenitors and stem cells by releasing active BMP4

    Directory of Open Access Journals (Sweden)

    Leprince Pierre

    2004-09-01

    Full Text Available Abstract Background Spontaneous repair is limited after CNS injury or degeneration because neurogenesis and axonal regrowth rarely occur in the adult brain. As a result, cell transplantation has raised much interest as potential treatment for patients with CNS lesions. Several types of cells have been considered as candidates for such cell transplantation and replacement therapies. Foetal brain tissue has already been shown to have significant effects in patients with Parkinson's disease. Clinical use of the foetal brain tissue is, however, limited by ethical and technical problems as it requires high numbers of grafted foetal cells and immunosuppression. Alternatively, several reports suggested that mesenchymal stem cells, isolated from adult bone marrow, are multipotent cells and could be used in autograft approach for replacement therapies. Results In this study, we addressed the question of the possible influence of mesenchymal stem cells on neural stem cell fate. We have previously reported that adult rat mesenchymal stem cells are able to express nestin in defined culture conditions (in the absence of serum and after 25 cell population doublings and we report here that nestin-positive (but not nestin-negative mesenchymal stem cells are able to favour the astroglial lineage in neural progenitors and stem cells cultivated from embryonic striatum. The increase of the number of GFAP-positive cells is associated with a significant decrease of the number of Tuj1- and O4-positive cells. Using quantitative RT-PCR, we demonstrate that mesenchymal stem cells express LIF, CNTF, BMP2 and BMP4 mRNAs, four cytokines known to play a role in astroglial fate decision. In this model, BMP4 is responsible for the astroglial stimulation and oligodendroglial inhibition, as 1 this cytokine is present in a biologically-active form only in nestin-positive mesenchymal stem cells conditioned medium and 2 anti-BMP4 antibodies inhibit the nestin-positive mesenchymal

  12. Defibrotide in combination with granulocyte colony-stimulating factor significantly enhances the mobilization of primitive and committed peripheral blood progenitor cells in mice.

    Science.gov (United States)

    Carlo-Stella, Carmelo; Di Nicola, Massimo; Magni, Michele; Longoni, Paolo; Milanesi, Marco; Stucchi, Claudio; Cleris, Loredana; Formelli, Franca; Gianni, Massimo A

    2002-11-01

    Defibrotide is a polydeoxyribonucleotide, which significantly reduces the expression of adhesion molecules on endothelial cells. We investigated the activity of Defibrotide alone or in combination with recombinant human granulocyte colony-stimulating factor (rhG-CSF) to mobilize peripheral blood progenitor cells (PBPCs) in BALB/c mice. A 5-day treatment with Defibrotide alone (1-15 mg/mouse/day) had no effect on WBC counts, frequencies and absolute numbers of total circulating colony-forming cells (CFCs), i.e., granulocyte-macrophage colony-forming units, erythroid burst-forming units, and multilineage colony-forming units. As compared with mock-injected mice, administration of rhG-CSF alone (5 micro g/mouse/day) for 5 days significantly (P Defibrotide (15 mg/mouse/day) and rhG-CSF significantly (P Defibrotide plus rhG-CSF resulted in a significant increase (P Defibrotide/rhG-CSF-mobilized mononuclear cells rescued 43% and 71% of recipient mice, respectively. Experiments of CFC homing performed in lethally irradiated or nonirradiated recipients showed that marrow homing of transplanted PBPCs was reduced by 3-fold in Defibrotide-treated animals as compared with mock-injected mice (P Defibrotide might be because of an effect on PBPC trafficking. In conclusion, our data demonstrate that Defibrotide synergizes with rhG-CSF and significantly increases the mobilization of a broad spectrum of PBPCs, including primitive and committed progenitor cells. These data might have relevant implications for autologous and allogeneic anticancer therapy in humans.

  13. The role of tumor suppressor p15Ink4b in the regulation of hematopoietic progenitor cell fate

    International Nuclear Information System (INIS)

    Humeniuk, R; Rosu-Myles, M; Fares, J; Koller, R; Bies, J; Wolff, L

    2013-01-01

    Epigenetic silencing of the tumor suppressor gene p15Ink4b (CDKN2B) is a frequent event in blood disorders like acute myeloid leukemia and myelodysplastic syndromes. The molecular function of p15Ink4b in hematopoietic differentiation still remains to be elucidated. Our previous study demonstrated that loss of p15Ink4b in mice results in skewing of the differentiation pattern of the common myeloid progenitor towards the myeloid lineage. Here, we investigated a function of p15Ink4b tumor suppressor gene in driving erythroid lineage commitment in hematopoietic progenitors. It was found that p15Ink4b is expressed more highly in committed megakaryocyte–erythroid progenitors than granulocyte–macrophage progenitors. More importantly, mice lacking p15Ink4b have lower numbers of primitive red cell progenitors and a severely impaired response to 5-fluorouracil- and phenylhydrazine-induced hematopoietic stress. Introduction of p15Ink4b into multipotential progenitors produced changes at the molecular level, including activation of mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK/ERK) signaling, increase GATA-1, erythropoietin receptor (EpoR) and decrease Pu1, GATA-2 expression. These changes rendered cells more permissive to erythroid commitment and less permissive to myeloid commitment, as demonstrated by an increase in early burst-forming unit-erythroid formation with concomitant decrease in myeloid colonies. Our results indicate that p15Ink4b functions in hematopoiesis, by maintaining proper lineage commitment of progenitors and assisting in rapid red blood cells replenishment following stress

  14. Defining the Minimal Factors Required for Erythropoiesis through Direct Lineage Conversion

    Directory of Open Access Journals (Sweden)

    Sandra Capellera-Garcia

    2016-06-01

    Full Text Available Erythroid cell commitment and differentiation proceed through activation of a lineage-restricted transcriptional network orchestrated by a group of well characterized genes. However, the minimal set of factors necessary for instructing red blood cell (RBC development remains undefined. We employed a screen for transcription factors allowing direct lineage reprograming from fibroblasts to induced erythroid progenitors/precursors (iEPs. We show that Gata1, Tal1, Lmo2, and c-Myc (GTLM can rapidly convert murine and human fibroblasts directly to iEPs. The transcriptional signature of murine iEPs resembled mainly that of primitive erythroid progenitors in the yolk sac, whereas addition of Klf1 or Myb to the GTLM cocktail resulted in iEPs with a more adult-type globin expression pattern. Our results demonstrate that direct lineage conversion is a suitable platform for defining and studying the core factors inducing the different waves of erythroid development.

  15. Mobilization of primitive and committed hematopoietic progenitors in nonhuman primates treated with defibrotide and recombinant human granulocyte colony-stimulating factor.

    Science.gov (United States)

    Carlo-Stella, Carmelo; Di Nicola, Massimo; Longoni, Paolo; Milani, Raffaella; Milanesi, Marco; Guidetti, Anna; Haanstra, Krista; Jonker, Margaret; Cleris, Loredana; Magni, Michele; Formelli, Franca; Gianni, Alesssandro M

    2004-01-01

    The aim of this study was to evaluate the capacity of defibrotide in enhancing cytokine-induced hematopoietic mobilization in rhesus monkeys. Animals received recombinant human granulocyte colony-stimulating factor (rhG-CSF, 100 microg/kg/day SC for 5 days) and, after a 4- to 6-week washout period, were remobilized with defibrotide (15 mg/kg/hour continuous intravenous for 5 days) plus rhG-CSF. Hematopoietic mobilization was evaluated by complete blood counts, differential counts, as well as frequency and absolute numbers of colony-forming cells (CFCs), high-proliferative potential CFCs (HPP-CFCs), and long-term culture-initiating cells (LTC-ICs). Compared to baseline values, rhG-CSF increased circulating CFCs, HPP-CFCs, and LTC-ICs by 158-, 125-, and 67-fold, respectively; the same figures for defibrotide/rhG-CSF were 299-, 1452-, and 295-fold, respectively. Defibrotide/rhG-CSF treatment compared to rhG-CSF alone increased CFCs, HPP-CFCs, and LTC-ICs by 1.4- (35,089 vs 25,825, pdefibrotide treatment associated with a 5-day rhG-CSF treatment. Compared to rhG-CSF, defibrotide/rhG-CSF increased the mobilization of CFCs, HPP-CFCs, and LTC-ICs by 2- (31,128 vs 15,527, pdefibrotide enhances rhG-CSF-elicited mobilization of primitive and committed progenitors; and 2) a 2-day defibrotide injection is as effective as a 5-day injection.

  16. Instruction of hematopoietic lineage choice by cytokine signaling

    Energy Technology Data Exchange (ETDEWEB)

    Endele, Max; Etzrodt, Martin; Schroeder, Timm, E-mail: timm.schroeder@bsse.ethz.ch

    2014-12-10

    Hematopoiesis is the cumulative consequence of finely tuned signaling pathways activated through extrinsic factors, such as local niche signals and systemic hematopoietic cytokines. Whether extrinsic factors actively instruct the lineage choice of hematopoietic stem and progenitor cells or are only selectively allowing survival and proliferation of already intrinsically lineage-committed cells has been debated over decades. Recent results demonstrated that cytokines can instruct lineage choice. However, the precise function of individual cytokine-triggered signaling molecules in inducing cellular events like proliferation, lineage choice, and differentiation remains largely elusive. Signal transduction pathways activated by different cytokine receptors are highly overlapping, but support the production of distinct hematopoietic lineages. Cellular context, signaling dynamics, and the crosstalk of different signaling pathways determine the cellular response of a given extrinsic signal. New tools to manipulate and continuously quantify signaling events at the single cell level are therefore required to thoroughly interrogate how dynamic signaling networks yield a specific cellular response. - Highlights: • Recent studies provided definite proof for lineage-instructive action of cytokines. • Signaling pathways involved in hematopoietic lineage instruction remain elusive. • New tools are emerging to quantitatively study dynamic signaling networks over time.

  17. High-content image informatics of the structural nuclear protein NuMA parses trajectories for stem/progenitor cell lineages and oncogenic transformation.

    Science.gov (United States)

    Vega, Sebastián L; Liu, Er; Arvind, Varun; Bushman, Jared; Sung, Hak-Joon; Becker, Matthew L; Lelièvre, Sophie; Kohn, Joachim; Vidi, Pierre-Alexandre; Moghe, Prabhas V

    2017-02-01

    Stem and progenitor cells that exhibit significant regenerative potential and critical roles in cancer initiation and progression remain difficult to characterize. Cell fates are determined by reciprocal signaling between the cell microenvironment and the nucleus; hence parameters derived from nuclear remodeling are ideal candidates for stem/progenitor cell characterization. Here we applied high-content, single cell analysis of nuclear shape and organization to examine stem and progenitor cells destined to distinct differentiation endpoints, yet undistinguishable by conventional methods. Nuclear descriptors defined through image informatics classified mesenchymal stem cells poised to either adipogenic or osteogenic differentiation, and oligodendrocyte precursors isolated from different regions of the brain and destined to distinct astrocyte subtypes. Nuclear descriptors also revealed early changes in stem cells after chemical oncogenesis, allowing the identification of a class of cancer-mitigating biomaterials. To capture the metrology of nuclear changes, we developed a simple and quantitative "imaging-derived" parsing index, which reflects the dynamic evolution of the high-dimensional space of nuclear organizational features. A comparative analysis of parsing outcomes via either nuclear shape or textural metrics of the nuclear structural protein NuMA indicates the nuclear shape alone is a weak phenotypic predictor. In contrast, variations in the NuMA organization parsed emergent cell phenotypes and discerned emergent stages of stem cell transformation, supporting a prognosticating role for this protein in the outcomes of nuclear functions. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Spatio-temporal Model of Endogenous ROS and Raft-Dependent WNT/Beta-Catenin Signaling Driving Cell Fate Commitment in Human Neural Progenitor Cells

    Science.gov (United States)

    Haack, Fiete; Lemcke, Heiko; Ewald, Roland; Rharass, Tareck; Uhrmacher, Adelinde M.

    2015-01-01

    Canonical WNT/β-catenin signaling is a central pathway in embryonic development, but it is also connected to a number of cancers and developmental disorders. Here we apply a combined in-vitro and in-silico approach to investigate the spatio-temporal regulation of WNT/β-catenin signaling during the early neural differentiation process of human neural progenitors cells (hNPCs), which form a new prospect for replacement therapies in the context of neurodegenerative diseases. Experimental measurements indicate a second signal mechanism, in addition to canonical WNT signaling, being involved in the regulation of nuclear β-catenin levels during the cell fate commitment phase of neural differentiation. We find that the biphasic activation of β-catenin signaling observed experimentally can only be explained through a model that combines Reactive Oxygen Species (ROS) and raft dependent WNT/β-catenin signaling. Accordingly after initiation of differentiation endogenous ROS activates DVL in a redox-dependent manner leading to a transient activation of down-stream β-catenin signaling, followed by continuous auto/paracrine WNT signaling, which crucially depends on lipid rafts. Our simulation studies further illustrate the elaborate spatio-temporal regulation of DVL, which, depending on its concentration and localization, may either act as direct inducer of the transient ROS/β-catenin signal or as amplifier during continuous auto-/parcrine WNT/β-catenin signaling. In addition we provide the first stochastic computational model of WNT/β-catenin signaling that combines membrane-related and intracellular processes, including lipid rafts/receptor dynamics as well as WNT- and ROS-dependent β-catenin activation. The model’s predictive ability is demonstrated under a wide range of varying conditions for in-vitro and in-silico reference data sets. Our in-silico approach is realized in a multi-level rule-based language, that facilitates the extension and modification of the

  19. Immunoliposome-mediated delivery of neomycin phosphotransferase for the lineage-specific selection of differentiated/committed stem cell progenies: potential advantages over transfection with marker genes, fluorescence-activated and magnetic affinity cell-sorting.

    Science.gov (United States)

    Heng, Boon Chin; Cao, Tong

    2005-01-01

    A major challenge in the therapeutic application of stem cells in regenerative medicine is the lineage-specific selection of their committed/differentiated progenies for transplantation. This is necessary to avoid engraftment of undesired lineages at the transplantation site, i.e. fibroblastic scar tissue, as well as to enhance the efficacy of transplantation therapy. Commonly used techniques for lineage-specific selection of committed/differentiated stem cell progenies include marker gene transfection, fluorescence-activated (FACS) and magnetic-affinity (MACS) cell-sorting. Nevertheless, these have their disadvantages for therapeutic applications. Marker gene transfection invariably leads to permanent genetic modification of stem cells, which in turn limits their use in human clinical therapy due to overwhelming ethical and safety concerns. FACS requires expensive instrumentation and highly-skilled personnel, and is unsuited for handling bulk quantities of cells that would almost certainly be required for transplantation therapy. MACS is a cheaper alternative, but the level of purity attained is also reduced. A possible novel approach that has yet to be investigated is immunoliposome-mediated delivery of neomycin phosphotranferase (NPT) for lineage-specific selection of stem cell progenies. This would avoid permanent genetic modification to the cell, unlike recombinant NPT expression linked to activation of specific promoter sequences. Moreover, it could potentially provide a much more practical and cost-effective alternative for handling bulk quantities of cells that would be required for transplantation therapy, as compared to FACS or MACS. As such, this alternative approach needs to be rigorously investigated, in view of its potentially useful applications in stem cell therapeutics.

  20. Changing patterns of radiosensitivity of hematopoietic progenitors from chronically irradiated dogs prone either to aplastic anemia or to myeloproliferative disease

    International Nuclear Information System (INIS)

    Seed, T.M.; Kaspar, L.V.

    1990-01-01

    Hematopoietic patterns have been assessed in chronic 60 Co gamma irradiated dogs during preclinical phases of evolving aplastic anemia (AA) or myeloproliferative disease (MPD), principally myeloid leukemia. The results support the concept that acquired radioresistance of vital granulocyte/monocyte lineage-committed hematopoietic progenitors is temporally, perhaps causally, linked to the processes mediating hematopoietic recovery and accommodation under chronic irradiation, and in turn to preclinical events of evolving MPD. In addition, the marked differential responses of progenitors to gamma and neutron irradiation in vitro might suggest differences in the nature of cellular lesions elicited by chronic gamma irradiation, in vivo. (author)

  1. Changing patterns of radiosensitivity of hematopoietic progenitors from chronically irradiated dogs prone either to aplastic anemia or to myeloproliferative disease

    Energy Technology Data Exchange (ETDEWEB)

    Seed, T.M.; Kaspar, L.V. (Oak Ridge National Lab., TN (USA))

    1990-01-01

    Hematopoietic patterns have been assessed in chronic {sup 60}Co gamma irradiated dogs during preclinical phases of evolving aplastic anemia (AA) or myeloproliferative disease (MPD), principally myeloid leukemia. The results support the concept that acquired radioresistance of vital granulocyte/monocyte lineage-committed hematopoietic progenitors is temporally, perhaps causally, linked to the processes mediating hematopoietic recovery and accommodation under chronic irradiation, and in turn to preclinical events of evolving MPD. In addition, the marked differential responses of progenitors to gamma and neutron irradiation in vitro might suggest differences in the nature of cellular lesions elicited by chronic gamma irradiation, in vivo. (author).

  2. SIRPA, VCAM1 and CD34 identify discrete lineages during early human cardiovascular development

    Directory of Open Access Journals (Sweden)

    Rhys J.P. Skelton

    2014-07-01

    Full Text Available The study of human cardiogenesis would benefit from a detailed cell lineage fate map akin to that established for the haematopoietic lineages. Here we sought to define cell lineage relationships based on the expression of NKX2-5 and the cell surface markers VCAM1, SIRPA and CD34 during human cardiovascular development. Expression of NKX2-5GFP was used to identify cardiac progenitors and cardiomyocytes generated during the differentiation of NKX2-5GFP/w human embryonic stem cells (hESCs. Cardiovascular cell lineages sub-fractionated on the basis of SIRPA, VCAM1 and CD34 expression were assayed for differentiation potential and gene expression. The NKX2-5posCD34pos population gave rise to endothelial cells that rapidly lost NKX2-5 expression in culture. Conversely, NKX2-5 expression was maintained in myocardial committed cells, which progressed from being NKX2-5posSIRPApos to NKX2-5posSIRPAposVCAM1pos. Up-regulation of VCAM1 was accompanied by the expression of myofilament markers and reduced clonal capacity, implying a restriction of cell fate potential. Combinatorial expression of NKX2-5, SIRPA, VCAM1 and CD34 can be used to define discrete stages of cardiovascular cell lineage differentiation. These markers identify specific stages of cardiomyocyte and endothelial lineage commitment and, thus provide a scaffold for establishing a fate map of early human cardiogenesis.

  3. The fps/fes proto-oncogene regulates hematopoietic lineage output.

    Science.gov (United States)

    Sangrar, Waheed; Gao, Yan; Zirngibl, Ralph A; Scott, Michelle L; Greer, Peter A

    2003-12-01

    The fps/fes proto-oncogene is abundantly expressed in myeloid cells, and the Fps/Fes cytoplasmic protein-tyrosine kinase is implicated in signaling downstream from hematopoietic cytokines, including interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF), and erythropoietin (EPO). Studies using leukemic cell lines have previously suggested that Fps/Fes contributes to granulomonocytic differentiation, and that it might play a more selective role in promoting survival and differentiation along the monocytic pathway. In this study we have used a genetic approach to explore the role of Fps/Fes in hematopoiesis. We used transgenic mice that tissue-specifically express a mutant human fps/fes transgene (fps(MF)) that was engineered to encode Fps/Fes kinase that is activated through N-terminal myristoylation (MFps). Hematopoietic function was assessed using lineage analysis, hematopoietic progenitor cell colony-forming assays, and biochemical approaches. fps(MF) transgenic mice displayed a skewed hematopoietic output reflected by increased numbers of circulating granulocytic and monocytic cells and a corresponding decrease in lymphoid cells. Bone marrow colony assays of progenitor cells revealed a significant increase in the number of both granulomonocytic and multi-lineage progenitors. A molecular analysis of signaling in mature monocytic cells showed that MFps promoted GM-CSF-induced STAT3, STAT5, and ERK1/2 activation. These observations support a role for Fps/Fes in signaling pathways that contribute to lineage determination at the level of multi-lineage hematopoietic progenitors as well as the more committed granulomonocytic progenitors.

  4. Induced pluripotent stem cell-derived cardiac progenitors differentiate to cardiomyocytes and form biosynthetic tissues.

    Directory of Open Access Journals (Sweden)

    Nicolas Christoforou

    Full Text Available The mammalian heart has little capacity to regenerate, and following injury the myocardium is replaced by non-contractile scar tissue. Consequently, increased wall stress and workload on the remaining myocardium leads to chamber dilation, dysfunction, and heart failure. Cell-based therapy with an autologous, epigenetically reprogrammed, and cardiac-committed progenitor cell source could potentially reverse this process by replacing the damaged myocardium with functional tissue. However, it is unclear whether cardiac progenitor cell-derived cardiomyocytes are capable of attaining levels of structural and functional maturity comparable to that of terminally-fated cardiomyocytes. Here, we first describe the derivation of mouse induced pluripotent stem (iPS cells, which once differentiated allow for the enrichment of Nkx2-5(+ cardiac progenitors, and the cardiomyocyte-specific expression of the red fluorescent protein. We show that the cardiac progenitors are multipotent and capable of differentiating into endothelial cells, smooth muscle cells and cardiomyocytes. Moreover, cardiac progenitor selection corresponds to cKit(+ cell enrichment, while cardiomyocyte cell-lineage commitment is concomitant with dual expression of either cKit/Flk1 or cKit/Sca-1. We proceed to show that the cardiac progenitor-derived cardiomyocytes are capable of forming electrically and mechanically coupled large-scale 2D cell cultures with mature electrophysiological properties. Finally, we examine the cell progenitors' ability to form electromechanically coherent macroscopic tissues, using a physiologically relevant 3D culture model and demonstrate that following long-term culture the cardiomyocytes align, and form robust electromechanical connections throughout the volume of the biosynthetic tissue construct. We conclude that the iPS cell-derived cardiac progenitors are a robust cell source for tissue engineering applications and a 3D culture platform for pharmacological

  5. Insulin antagonises pigment epithelium-derived factor (PEDF)-induced modulation of lineage commitment of myocytes and heterotrophic ossification.

    Science.gov (United States)

    Carnagarin, Revathy; Elahy, Mina; Dharmarajan, Arun M; Dass, Crispin R

    2017-12-16

    Extensive bone defects arising as a result of trauma, infection and tumour resection and other bone pathologies necessitates the identification of effective strategies in the form of tissue engineering, gene therapy and osteoinductive agents to enhance the bone repair process. PEDF is a multifunctional glycoprotein which plays an important role in regulating osteoblastic differentiation and bone formation. PEDF treatment of mice and human skeletal myocytes at physiological concentration inhibited myogenic differentiation and activated Erk1/2 MAPK- dependent osteogenic transdifferentiation of myocytes. In mice, insulin, a promoter of bone regeneration, attenuated PEDF-induced expression of osteogenic markers such as osteocalcin, alkaline phosphatase and mineralisation for bone formation in the muscle and surrounding adipose tissue. These results provide new insights into the molecular aspects of the antagonising effect of insulin on PEDF-dependent modulation of the differentiation commitment of musculoskeletal environment into osteogenesis, and suggest that PEDF may be developed as an effective clinical therapy for bone regeneration as its heterotopic ossification can be controlled via co-administration of insulin. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Bone marrow niche-inspired, multi-phase expansion of megakaryocytic progenitors with high polyploidization potential

    Science.gov (United States)

    Panuganti, Swapna; Papoutsakis, Eleftherios T.; Miller, William M.

    2010-01-01

    Background Megakaryopoiesis encompasses hematopoietic stem and progenitor cell (HSPC) commitment to the megakaryocytic cell (Mk) lineage, expansion of Mk progenitors and mature Mks, polyploidization, and platelet release. pH and pO2 increase from the endosteum to sinuses, and different cytokines are important for various stages of differentiation. We hypothesized that mimicking the changing conditions during Mk differentiation in the bone marrow would facilitate expansion of progenitors that could generate many high-ploidy Mks. Methods CD34+ HSPCs were cultured at pH 7.2 and 5% O2 with stem cell factor (SCF), thrombopoietin (Tpo), and all combinations of Interleukin (IL)-3, IL-6, IL-11, and Flt-3 ligand to promote Mk progenitor expansion. Cells cultured with selected cytokines were shifted to pH 7.4 and 20% O2 to generate mature Mks, and treated with nicotinamide to enhance polyploidization. Results Using Tpo+SCF+IL-3+IL-11, we obtained 3.5 CD34+CD41+ Mk progenitors per input HSPC, while increasing purity from 1% to 17%. Cytokine cocktails with IL-3 yielded more progenitors and mature Mks, although the purities were lower. Mk production was much greater at higher pH and pO2. Although fewer progenitors were present, shifting to 20% O2/pH 7.4 at day 5 (versus days 7 or 9) yielded the greatest mature Mk production, 14 per input HSPC. Nicotinamide more than doubled the percentage of high-ploidy Mks to 40%. Discussion We obtained extensive Mk progenitor expansion, while ensuring that the progenitors could produce high-ploidy Mks. We anticipate that subsequent optimization of cytokines for mature Mk production and delayed nicotinamide addition will greatly increase high-ploidy Mk production. PMID:20482285

  7. Bone marrow niche-inspired, multiphase expansion of megakaryocytic progenitors with high polyploidization potential.

    Science.gov (United States)

    Panuganti, Swapna; Papoutsakis, Eleftherios T; Miller, William M

    2010-10-01

    Megakaryopoiesis encompasses hematopoietic stem and progenitor cell (HSPC) commitment to the megakaryocytic cell (Mk) lineage, expansion of Mk progenitors and mature Mks, polyploidization and platelet release. pH and pO2 increase from the endosteum to sinuses, and different cytokines are important for various stages of differentiation. We hypothesized that mimicking the changing conditions during Mk differentiation in the bone marrow would facilitate expansion of progenitors that could generate many high-ploidy Mks. CD34+ HSPCs were cultured at pH 7.2 and 5% O2 with stem cell factor (SCF), thrombopoietin (Tpo) and all combinations of Interleukin (IL)-3, IL-6, IL-11 and Flt-3 ligand to promote Mk progenitor expansion. Cells cultured with selected cytokines were shifted to pH 7.4 and 20% O2 to generate mature Mks, and treated with nicotinamide (NIC) to enhance polyploidization. Using Tpo + SCF + IL-3 + IL-11, we obtained 3.5 CD34+ CD41+ Mk progenitors per input HSPC, while increasing purity from 1% to 17%. Cytokine cocktails with IL-3 yielded more progenitors and mature Mks, although the purities were lower. Mk production was much greater at higher pH and pO2. Although fewer progenitors were present, shifting to 20% O2 /pH 7.4 at day 5 (versus days 7 or 9) yielded the greatest mature Mk production, 14 per input HSPC. NIC more than doubled the percentage of high-ploidy Mks to 40%. We obtained extensive Mk progenitor expansion, while ensuring that the progenitors could produce high-ploidy Mks. We anticipate that subsequent optimization of cytokines for mature Mk production and delayed NIC addition will greatly increase high-ploidy Mk production.

  8. Growth Factor-Activated Stem Cell Circuits and Stromal Signals Cooperatively Accelerate Non-Integrated iPSC Reprogramming of Human Myeloid Progenitors

    Science.gov (United States)

    Park, Tea Soon; Huo, Jeffrey S.; Peters, Ann; Talbot, C. Conover; Verma, Karan; Zimmerlin, Ludovic; Kaplan, Ian M.; Zambidis, Elias T.

    2012-01-01

    Nonviral conversion of skin or blood cells into clinically useful human induced pluripotent stem cells (hiPSC) occurs in only rare fractions (∼0.001%–0.5%) of donor cells transfected with non-integrating reprogramming factors. Pluripotency induction of developmentally immature stem-progenitors is generally more efficient than differentiated somatic cell targets. However, the nature of augmented progenitor reprogramming remains obscure, and its potential has not been fully explored for improving the extremely slow pace of non-integrated reprogramming. Here, we report highly optimized four-factor reprogramming of lineage-committed cord blood (CB) myeloid progenitors with bulk efficiencies of ∼50% in purified episome-expressing cells. Lineage-committed CD33+CD45+CD34− myeloid cells and not primitive hematopoietic stem-progenitors were the main targets of a rapid and nearly complete non-integrated reprogramming. The efficient conversion of mature myeloid populations into NANOG+TRA-1-81+ hiPSC was mediated by synergies between hematopoietic growth factor (GF), stromal activation signals, and episomal Yamanaka factor expression. Using a modular bioinformatics approach, we demonstrated that efficient myeloid reprogramming correlated not to increased proliferation or endogenous Core factor expressions, but to poised expression of GF-activated transcriptional circuits that commonly regulate plasticity in both hematopoietic progenitors and embryonic stem cells (ESC). Factor-driven conversion of myeloid progenitors to a high-fidelity pluripotent state was further accelerated by soluble and contact-dependent stromal signals that included an implied and unexpected role for Toll receptor-NFκB signaling. These data provide a paradigm for understanding the augmented reprogramming capacity of somatic progenitors, and reveal that efficient induced pluripotency in other cell types may also require extrinsic activation of a molecular framework that commonly regulates self

  9. Lineage Switching in Acute Leukemias: A Consequence of Stem Cell Plasticity?

    Directory of Open Access Journals (Sweden)

    Elisa Dorantes-Acosta

    2012-01-01

    Full Text Available Acute leukemias are the most common cancer in childhood and characterized by the uncontrolled production of hematopoietic precursor cells of the lymphoid or myeloid series within the bone marrow. Even when a relatively high efficiency of therapeutic agents has increased the overall survival rates in the last years, factors such as cell lineage switching and the rise of mixed lineages at relapses often change the prognosis of the illness. During lineage switching, conversions from lymphoblastic leukemia to myeloid leukemia, or vice versa, are recorded. The central mechanisms involved in these phenomena remain undefined, but recent studies suggest that lineage commitment of plastic hematopoietic progenitors may be multidirectional and reversible upon specific signals provided by both intrinsic and environmental cues. In this paper, we focus on the current knowledge about cell heterogeneity and the lineage switch resulting from leukemic cells plasticity. A number of hypothetical mechanisms that may inspire changes in cell fate decisions are highlighted. Understanding the plasticity of leukemia initiating cells might be fundamental to unravel the pathogenesis of lineage switch in acute leukemias and will illuminate the importance of a flexible hematopoietic development.

  10. Phosphorylations of Serines 21/9 in Glycogen Synthase Kinase 3α/β Are Not Required for Cell Lineage Commitment or WNT Signaling in the Normal Mouse Intestine.

    Directory of Open Access Journals (Sweden)

    Fiona Hey

    Full Text Available The WNT signalling pathway controls many developmental processes and plays a key role in maintenance of intestine renewal and homeostasis. Glycogen Synthase Kinase 3 (GSK3 is an important component of the WNT pathway and is involved in regulating β-catenin stability and expression of WNT target genes. The mechanisms underpinning GSK3 regulation in this context are not completely understood, with some evidence suggesting this occurs through inhibitory N-terminal serine phosphorylation in a similar way to GSK3 inactivation in insulin signaling. To investigate this in a physiologically relevant context, we have analysed the intestinal phenotype of GSK3 knockin mice in which N-terminal serines 21/9 of GSK3α/β have been mutated to non-phosphorylatable alanine residues. We show that these knockin mutations have very little effect on overall intestinal integrity, cell lineage commitment, β-catenin localization or WNT target gene expression although a small increase in apoptosis at villi tips is observed. Our results provide in vivo evidence that GSK3 is regulated through mechanisms independent of N-terminal serine phosphorylation in order for β-catenin to be stabilised.

  11. Intracoronary artery transplantation of cardiomyoblast-like cells from human adipose tissue-derived multi-lineage progenitor cells improve left ventricular dysfunction and survival in a swine model of chronic myocardial infarction

    Energy Technology Data Exchange (ETDEWEB)

    Okura, Hanayuki [The Center for Medical Engineering and Informatics, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0879 (Japan); Department of Somatic Stem Cell Therapy and Health Policy, Institute of Biomedical Research and Innovation, Foundation for Biomedical Research and Innovation, 2-2 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Saga, Ayami; Soeda, Mayumi [Department of Somatic Stem Cell Therapy and Health Policy, Institute of Biomedical Research and Innovation, Foundation for Biomedical Research and Innovation, 2-2 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Miyagawa, Shigeru; Sawa, Yoshiki [Department of Surgery, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka 565-0879 (Japan); Daimon, Takashi [Division of Biostatistics, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663-8501 (Japan); Ichinose, Akihiro [Department of Plastic Surgery, Kobe University Hospital, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo (Japan); Matsuyama, Akifumi, E-mail: akifumi-matsuyama@umin.ac.jp [The Center for Medical Engineering and Informatics, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0879 (Japan); Department of Plastic Surgery, Kobe University Hospital, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo (Japan); RIKEN Program for Drug Discovery and Medical Technology Platforms, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045 (Japan)

    2012-09-07

    Highlights: Black-Right-Pointing-Pointer We administered human CLCs in a swine model of MI via intracoronary artery. Black-Right-Pointing-Pointer Histological studies demonstrated engraftment of hCLCs into the scarred myocardium. Black-Right-Pointing-Pointer Echocardiography showed rescue of cardiac function in the hCLCs transplanted swine. Black-Right-Pointing-Pointer Transplantation of hCLCs is an effective therapeutics for cardiac regeneration. -- Abstract: Transplantation of human cardiomyoblast-like cells (hCLCs) from human adipose tissue-derived multi-lineage progenitor cells improved left ventricular function and survival of rats with myocardial infarction. Here we examined the effect of intracoronary artery transplantation of human CLCs in a swine model of chronic heart failure. Twenty-four pigs underwent balloon-occlusion of the first diagonal branch followed by reperfusion, with a second balloon-occlusion of the left ascending coronary artery 1 week later followed by reperfusion. Four weeks after the second occlusion/reperfusion, 17 of the 18 surviving animals with severe chronic MI (ejection fraction <35% by echocardiography) were immunosuppressed then randomly assigned to receive either intracoronary artery transplantation of hCLCs hADMPCs or placebo lactic Ringer's solution with heparin. Intracoronary artery transplantation was followed by the distribution of DiI-stained hCLCs into the scarred myocardial milieu. Echocardiography at post-transplant days 4 and 8 weeks showed rescue and maintenance of cardiac function in the hCLCs transplanted group, but not in the control animals, indicating myocardial functional recovery by hCLCs intracoronary transplantation. At 8 week post-transplantation, 7 of 8 hCLCs transplanted animals were still alive compared with only 1 of the 5 control (p = 0.0147). Histological studies at week 12 post-transplantation demonstrated engraftment of the pre DiI-stained hCLCs into the scarred myocardium and their expression of

  12. Pioneer factors govern super-enhancer dynamics in stem cell plasticity and lineage choice

    Science.gov (United States)

    Adam, Rene C.; Yang, Hanseul; Rockowitz, Shira; Larsen, Samantha B.; Nikolova, Maria; Oristian, Daniel S.; Polak, Lisa; Kadaja, Meelis; Asare, Amma; Zheng, Deyou; Fuchs, Elaine

    2015-01-01

    Adult stem cells (SCs) reside in niches which balance self-renewal with lineage selection and progression during tissue homeostasis. Following injury, culture or transplantation, SCs outside their niche often display fate flexibility1-4. Here we show that super-enhancers5 underlie the identity, lineage commitment and plasticity of adult SCs in vivo. Using hair follicle (HF) as model, we map the global chromatin domains of HFSCs and their committed progenitors in their native microenvironments. We show that super-enhancers and their dense clusters (‘epicenters’) of transcription factor (TF) binding sites change upon lineage progression. New fate is acquired by decommissioning old and establishing new super-enhancers and/or epicenters, an auto-regulatory process that abates one master regulator subset while enhancing another. We further show that when outside their niche, either in vitro or in wound-repair, HFSCs dynamically remodel super-enhancers in response to changes in their microenvironment. Intriguingly, some key super-enhancers shift epicenters, enabling them to remain active and maintain a transitional state in an ever-changing transcriptional landscape. Finally, we identify SOX9 as a crucial chromatin rheostat of HFSC super-enhancers, and provide functional evidence that super-enhancers are dynamic, dense TF-binding platforms which are acutely sensitive to pioneer master regulators whose levels define not only spatial and temporal features of lineage-status, but also stemness, plasticity in transitional states and differentiation. PMID:25799994

  13. Competence of failed endocrine progenitors to give rise to acinar but not ductal cells is restricted to early pancreas development.

    Science.gov (United States)

    Beucher, Anthony; Martín, Mercè; Spenle, Caroline; Poulet, Martine; Collin, Caitlin; Gradwohl, Gérard

    2012-01-15

    During mouse pancreas development, the transient expression of Neurogenin3 (Neurog3) in uncommitted pancreas progenitors is required to determine endocrine destiny. However it has been reported that Neurog3-expressing cells can eventually adopt acinar or ductal fates and that Neurog3 levels were important to secure the islet destiny. It is not known whether the competence of Neurog3-induced cells to give rise to non-endocrine lineages is an intrinsic property of these progenitors or depends on pancreas developmental stage. Using temporal genetic labeling approaches we examined the dynamic of endocrine progenitor differentiation and explored the plasticity of Neurog3-induced cells throughout development. We found that Neurog3(+) progenitors develop into hormone-expressing cells in a fast process taking less then 10h. Furthermore, fate-mapping studies in heterozygote (Neurog3(CreERT/+)) and Neurog3-deficient (Neurog3(CreERT/CreERT)) embryos revealed that Neurog3-induced cells have different potential over time. At the early bud stage, failed endocrine progenitors can adopt acinar or ductal fate, whereas later in the branching pancreas they do not contribute to the acinar lineage but Neurog3-deficient cells eventually differentiate into duct cells. Thus these results provide evidence that the plasticity of Neurog3-induced cells becomes restricted during development. Furthermore these data suggest that during the secondary transition, endocrine progenitor cells arise from bipotent precursors already committed to the duct/endocrine lineages and not from domain of cells having distinct potentialities. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. Generation of Induced Progenitor-like Cells from Mature Epithelial Cells Using Interrupted Reprogramming

    Directory of Open Access Journals (Sweden)

    Li Guo

    2017-12-01

    Full Text Available Summary: A suitable source of progenitor cells is required to attenuate disease or affect cure. We present an “interrupted reprogramming” strategy to generate “induced progenitor-like (iPL cells” using carefully timed expression of induced pluripotent stem cell reprogramming factors (Oct4, Sox2, Klf4, and c-Myc; OSKM from non-proliferative Club cells. Interrupted reprogramming allowed controlled expansion yet preservation of lineage commitment. Under clonogenic conditions, iPL cells expanded and functioned as a bronchiolar progenitor-like population to generate mature Club cells, mucin-producing goblet cells, and cystic fibrosis transmembrane conductance regulator (CFTR-expressing ciliated epithelium. In vivo, iPL cells can repopulate CFTR-deficient epithelium. This interrupted reprogramming process could be metronomically applied to achieve controlled progenitor-like proliferation. By carefully controlling the duration of expression of OSKM, iPL cells do not become pluripotent, and they maintain their memory of origin and retain their ability to efficiently return to their original phenotype. A generic technique to produce highly specified populations may have significant implications for regenerative medicine. : In this article Waddell, Nagy, and colleagues present an “interrupted reprogramming” strategy to produce highly specified functional “induced progenitor-like cells” from mature quiescent cells. They propose that careful control of the duration of transient expression of iPSC reprogramming factors (OSKM allows controlled expansion yet preservation of parental lineage without traversing the pluripotent state. Keywords: generation of induced progenitor-like cells

  15. Role of Notch signaling in cell-fate determination of human mammary stem/progenitor cells

    International Nuclear Information System (INIS)

    Dontu, Gabriela; Jackson, Kyle W; McNicholas, Erin; Kawamura, Mari J; Abdallah, Wissam M; Wicha, Max S

    2004-01-01

    Notch signaling has been implicated in the regulation of cell-fate decisions such as self-renewal of adult stem cells and differentiation of progenitor cells along a particular lineage. Moreover, depending on the cellular and developmental context, the Notch pathway acts as a regulator of cell survival and cell proliferation. Abnormal expression of Notch receptors has been found in different types of epithelial metaplastic lesions and neoplastic lesions, suggesting that Notch may act as a proto-oncogene. The vertebrate Notch1 and Notch4 homologs are involved in normal development of the mammary gland, and mutated forms of these genes are associated with development of mouse mammary tumors. In order to determine the role of Notch signaling in mammary cell-fate determination, we have utilized a newly described in vitro system in which mammary stem/progenitor cells can be cultured in suspension as nonadherent 'mammospheres'. Notch signaling was activated using exogenous ligands, or was inhibited using previously characterized Notch signaling antagonists. Utilizing this system, we demonstrate that Notch signaling can act on mammary stem cells to promote self-renewal and on early progenitor cells to promote their proliferation, as demonstrated by a 10-fold increase in secondary mammosphere formation upon addition of a Notch-activating DSL peptide. In addition to acting on stem cells, Notch signaling is also able to act on multipotent progenitor cells, facilitating myoepithelial lineage-specific commitment and proliferation. Stimulation of this pathway also promotes branching morphogenesis in three-dimensional Matrigel cultures. These effects are completely inhibited by a Notch4 blocking antibody or a gamma secretase inhibitor that blocks Notch processing. In contrast to the effects of Notch signaling on mammary stem/progenitor cells, modulation of this pathway has no discernable effect on fully committed, differentiated, mammary epithelial cells. These studies

  16. Ascl1 (Mash1) lineage cells contribute to discrete cell populations in CNS architecture

    OpenAIRE

    Kim, Euiseok J.; Battiste, James; Nakagawa, Yasushi; Johnson, Jane E.

    2008-01-01

    Ascl1 (previously Mash1) is a bHLH transcription factor essential for neuronal differentiation and specification in the nervous system. Although it has been studied for its role in several neural lineages, the full complement of lineages arising from Ascl1 progenitor cells remains unknown. Using an inducible Cre-flox genetic fate mapping strategy, Ascl1 lineages were determined throughout the brain. Ascl1 is present in proliferating progenitor cells but these cells are actively differentiatin...

  17. A mex3 homolog is required for differentiation during planarian stem cell lineage development

    Science.gov (United States)

    Zhu, Shu Jun; Hallows, Stephanie E; Currie, Ko W; Xu, ChangJiang; Pearson, Bret J

    2015-01-01

    Neoblasts are adult stem cells (ASCs) in planarians that sustain cell replacement during homeostasis and regeneration of any missing tissue. While numerous studies have examined genes underlying neoblast pluripotency, molecular pathways driving postmitotic fates remain poorly defined. In this study, we used transcriptional profiling of irradiation-sensitive and irradiation-insensitive cell populations and RNA interference (RNAi) functional screening to uncover markers and regulators of postmitotic progeny. We identified 32 new markers distinguishing two main epithelial progenitor populations and a planarian homolog to the MEX3 RNA-binding protein (Smed-mex3-1) as a key regulator of lineage progression. mex3-1 was required for generating differentiated cells of multiple lineages, while restricting the size of the stem cell compartment. We also demonstrated the utility of using mex3-1(RNAi) animals to identify additional progenitor markers. These results identified mex3-1 as a cell fate regulator, broadly required for differentiation, and suggest that mex3-1 helps to mediate the balance between ASC self-renewal and commitment. DOI: http://dx.doi.org/10.7554/eLife.07025.001 PMID:26114597

  18. Expression and function of PML-RARA in the hematopoietic progenitor cells of Ctsg-PML-RARA mice.

    Directory of Open Access Journals (Sweden)

    Lukas D Wartman

    Full Text Available Because PML-RARA-induced acute promyelocytic leukemia (APL is a morphologically differentiated leukemia, many groups have speculated about whether its leukemic cell of origin is a committed myeloid precursor (e.g. a promyelocyte versus an hematopoietic stem/progenitor cell (HSPC. We originally targeted PML-RARA expression with CTSG regulatory elements, based on the early observation that this gene was maximally expressed in cells with promyelocyte morphology. Here, we show that both Ctsg, and PML-RARA targeted to the Ctsg locus (in Ctsg-PML-RARA mice, are expressed in the purified KLS cells of these mice (KLS = Kit(+Lin(-Sca(+, which are highly enriched for HSPCs, and this expression results in biological effects in multi-lineage competitive repopulation assays. Further, we demonstrate the transcriptional consequences of PML-RARA expression in Ctsg-PML-RARA mice in early myeloid development in other myeloid progenitor compartments [common myeloid progenitors (CMPs and granulocyte/monocyte progenitors (GMPs], which have a distinct gene expression signature compared to wild-type (WT mice. Although PML-RARA is indeed expressed at high levels in the promyelocytes of Ctsg-PML-RARA mice and alters the transcriptional signature of these cells, it does not induce their self-renewal. In sum, these results demonstrate that in the Ctsg-PML-RARA mouse model of APL, PML-RARA is expressed in and affects the function of multipotent progenitor cells. Finally, since PML/Pml is normally expressed in the HSPCs of both humans and mice, and since some human APL samples contain TCR rearrangements and express T lineage genes, we suggest that the very early hematopoietic expression of PML-RARA in this mouse model may closely mimic the physiologic expression pattern of PML-RARA in human APL patients.

  19. Individual differences in the radiosensitivity of hematopoietic progenitor cells detected in steady-state human peripheral blood

    International Nuclear Information System (INIS)

    Oriya, Asami; Takahashi, Kenji; Kashiwakura, Ikuo; Inanami, Osamu; Kuwabara, Mikinori; Miura, Toshiaki; Abe, Yoshinao

    2008-01-01

    The aim of this study is to evaluate the individual differences in radiosensitivity of lineage-committed myeloid hematopoietic progenitors, colony-forming cells (CFC), detected in steady-state human peripheral blood (PB). Mononuclear cells were prepared from the buffy-coat of 30 individuals PB, and were assayed for CFC by semi-solid culture supplemented with cytokines. X irradiation was performed in the range of 0.5-4 Gy at a dose rate of about 80 cGy/min. The mean number of hematopoietic progenitor cells is 5866±3408 in 1 ml of buffy-coat, suggesting that the erythroid progenitor cells are the major population. The total CFC radiosensitivity parameter D 0 and n value are 1.18±0.24 and 1.89±0.98, respectively. Using a linear regression analysis, a statistically significant correlation is observed between the D 0 value and the surviving fraction at 4 Gy (r=0.611 p 0 parameter and the level of antioxidants, plasma uric acid, plasma bilirubin, and intracellular glutathione. The present study demonstrates that there are large individual differences in the radiosensitivity of hematopoietic progenitor cells as detected in steady-state human PB. These differences demonstrate almost no correlation with plasma or intracellular antioxidants. The prediction of individual differences in radiosensitivity of CFC can only be measured by 4 Gy irradiation. (author)

  20. C/EBPα Is Required for Long-Term Self-Renewal and Lineage Priming of Hematopoietic Stem Cells and for the Maintenance of Epigenetic Configurations in Multipotent Progenitors

    DEFF Research Database (Denmark)

    Hasemann, Marie S; Lauridsen, Felicia K B; Waage, Johannes

    2014-01-01

    Transcription factors are key regulators of hematopoietic stem cells (HSCs) and act through their ability to bind DNA and impact on gene transcription. Their functions are interpreted in the complex landscape of chromatin, but current knowledge on how this is achieved is very limited. C...... as a priming factor at the HSC level where it actively promotes myeloid differentiation and counteracts lymphoid lineage choice. Taken together, our results show that C/EBPα is a key regulator of HSC biology, which influences the epigenetic landscape of HSCs in order to balance different cell fate options......./EBPα is an important transcriptional regulator of hematopoiesis, but its potential functions in HSCs have remained elusive. Here we report that C/EBPα serves to protect adult HSCs from apoptosis and to maintain their quiescent state. Consequently, deletion of Cebpa is associated with loss of self-renewal and HSC...

  1. Dedifferentiation of Human Primary Thyrocytes into Multilineage Progenitor Cells without Gene Introduction

    Science.gov (United States)

    Saenko, Vladimir; Suzuki, Masatoshi; Matsuse, Michiko; Ohtsuru, Akira; Kumagai, Atsushi; Uga, Tatsuya; Yano, Hiroshi; Nagayama, Yuji; Yamashita, Shunichi

    2011-01-01

    While identification and isolation of adult stem cells have potentially important implications, recent reports regarding dedifferentiation/reprogramming from differentiated cells have provided another clue to gain insight into source of tissue stem/progenitor cells. In this study, we developed a novel culture system to obtain dedifferentiated progenitor cells from normal human thyroid tissues. After enzymatic digestion, primary thyrocytes, expressing thyroglobulin, vimentin and cytokeratin-18, were cultured in a serum-free medium called SAGM. Although the vast majority of cells died, a small proportion (∼0.5%) survived and proliferated. During initial cell expansion, thyroglobulin/cytokeratin-18 expression was gradually declined in the proliferating cells. Moreover, sorted cells expressing thyroid peroxidase gave rise to proliferating clones in SAGM. These data suggest that those cells are derived from thyroid follicular cells or at least thyroid-committed cells. The SAGM-grown cells did not express any thyroid-specific genes. However, after four-week incubation with FBS and TSH, cytokeratin-18, thyroglobulin, TSH receptor, PAX8 and TTF1 expressions re-emerged. Moreover, surprisingly, the cells were capable of differentiating into neuronal or adipogenic lineage depending on differentiating conditions. In summary, we have developed a novel system to generate multilineage progenitor cells from normal human thyroid tissues. This seems to be achieved by dedifferentiation of thyroid follicular cells. The presently described culture system may be useful for regenerative medicine, but the primary importance will be as a tool to elucidate the mechanisms of thyroid diseases. PMID:21556376

  2. Myelo-erythroid commitment after burn injury is under β-adrenergic control via MafB regulation.

    Science.gov (United States)

    Hasan, Shirin; Johnson, Nicholas B; Mosier, Michael J; Shankar, Ravi; Conrad, Peggie; Szilagyi, Andrea; Gamelli, Richard L; Muthumalaiappan, Kuzhali

    2017-03-01

    Severely injured burn patients receive multiple blood transfusions for anemia of critical illness despite the adverse consequences. One limiting factor to consider alternate treatment strategies is the lack of a reliable test platform to study molecular mechanisms of impaired erythropoiesis. This study illustrates how conditions resulting in a high catecholamine microenvironment such as burns can instigate myelo-erythroid reprioritization influenced by β-adrenergic stimulation leading to anemia. In a mouse model of scald burn injury, we observed, along with a threefold increase in bone marrow LSK cells (lin neg Sca1 + cKit + ), that the myeloid shift is accompanied with a significant reduction in megakaryocyte erythrocyte progenitors (MEPs). β-Blocker administration (propranolol) for 6 days after burn, not only reduced the number of LSKs and MafB + cells in multipotent progenitors, but also influenced myelo-erythroid bifurcation by increasing the MEPs and reducing the granulocyte monocyte progenitors in the bone marrow of burn mice. Furthermore, similar results were observed in burn patients' peripheral blood mononuclear cell-derived ex vivo culture system, demonstrating that commitment stage of erythropoiesis is impaired in burn patients and intervention with propranolol (nonselective β1,2-adrenergic blocker) increases MEPs. Also, MafB + cells that were significantly increased following standard burn care could be mitigated when propranolol was administered to burn patients, establishing the mechanistic regulation of erythroid commitment by myeloid regulatory transcription factor MafB. Overall, results demonstrate that β-adrenergic blockers following burn injury can redirect the hematopoietic commitment toward erythroid lineage by lowering MafB expression in multipotent progenitors and be of potential therapeutic value to increase erythropoietin responsiveness in burn patients. Copyright © 2017 the American Physiological Society.

  3. Fuzzy Commitment

    Science.gov (United States)

    Juels, Ari

    The purpose of this chapter is to introduce fuzzy commitment, one of the earliest and simplest constructions geared toward cryptography over noisy data. The chapter also explores applications of fuzzy commitment to two problems in data security: (1) secure management of biometrics, with a focus on iriscodes, and (2) use of knowledge-based authentication (i.e., personal questions) for password recovery.

  4. Zinc finger protein 521 antagonizes early B-cell factor 1 and modulates the B-lymphoid differentiation of primary hematopoietic progenitors.

    Science.gov (United States)

    Mega, Tiziana; Lupia, Michela; Amodio, Nicola; Horton, Sarah J; Mesuraca, Maria; Pelaggi, Daniela; Agosti, Valter; Grieco, Michele; Chiarella, Emanuela; Spina, Raffaella; Moore, Malcolm A S; Schuringa, Jan Jacob; Bond, Heather M; Morrone, Giovanni

    2011-07-01

    Zinc finger protein 521 (EHZF/ZNF521) is a multi-functional transcription co-factor containing 30 zinc fingers and an amino-terminal motif that binds to the nucleosome remodelling and histone deacetylase (NuRD) complex. ZNF521 is believed to be a relevant player in the regulation of the homeostasis of the hematopoietic stem/progenitor cell compartment, however the underlying molecular mechanisms are still largely unknown. Here, we show that this protein plays an important role in the control of B-cell development by inhibiting the activity of early B-cell factor-1 (EBF1), a master factor in B-lineage specification. In particular, our data demonstrate that: (1) ZNF521 binds to EBF1 via its carboxyl-terminal portion and this interaction is required for EBF1 inhibition; (2) NuRD complex recruitment by ZNF521 is not essential for the inhibition of transactivation of EBF1-dependent promoters; (3) ZNF521 represses EBF1 target genes in a human B-lymphoid molecular context; and (4) RNAi-mediated silencing of ZNF521/Zfp521 in primary human and murine hematopoietic progenitors strongly enhances the generation of B-lymphocytes in vitro. Taken together, our data indicate that ZNF521 can antagonize B-cell development and lend support to the notion that it may contribute to conserve the multipotency of primitive lympho-myeloid progenitors by preventing or delaying their EBF1-driven commitment toward the B-cell lineage.

  5. Macrophages control vascular stem/progenitor cell plasticity through tumor necrosis factor-α-mediated nuclear factor-κB activation.

    Science.gov (United States)

    Wong, Mei Mei; Chen, Yikuan; Margariti, Andriani; Winkler, Bernhard; Campagnolo, Paola; Potter, Claire; Hu, Yanhua; Xu, Qingbo

    2014-03-01

    Vascular lineage differentiation of stem/progenitor cells can contribute to both tissue repair and exacerbation of vascular diseases such as in vein grafts. The role of macrophages in controlling vascular progenitor differentiation is largely unknown and may play an important role in graft development. This study aims to identify the role of macrophages in vascular stem/progenitor cell differentiation and thereafter elucidate the mechanisms that are involved in the macrophage- mediated process. We provide in vitro evidence that macrophages can induce endothelial cell (EC) differentiation of the stem/progenitor cells while simultaneously inhibiting their smooth muscle cell differentiation. Mechanistically, both effects were mediated by macrophage-derived tumor necrosis factor-α (TNF-α) via TNF-α receptor 1 and canonical nuclear factor-κB activation. Although the overexpression of p65 enhanced EC (or attenuated smooth muscle cell) differentiation, p65 or TNF-α receptor 1 knockdown using lentiviral short hairpin RNA inhibited EC (or rescued smooth muscle cell) differentiation in response to TNF-α. Furthermore, TNF-α-mediated EC differentiation was driven by direct binding of nuclear factor-κB (p65) to specific VE-cadherin promoter sequences. Subsequent experiments using an ex vivo decellularized vessel scaffold confirmed an increase in the number of ECs and reduction in smooth muscle cell marker expression in the presence of TNF-α. The lack of TNF-α in a knockout mouse model of vein graft decreased endothelialization and significantly increased thrombosis formation. Our study highlights the role of macrophages in directing vascular stem/progenitor cell lineage commitment through TNF-α-mediated TNF-α receptor 1 and nuclear factor-κB activation that is likely required for endothelial repair in vascular diseases such as vein graft.

  6. Ck2-Dependent Phosphorylation Is Required to Maintain Pax7 Protein Levels in Proliferating Muscle Progenitors.

    Directory of Open Access Journals (Sweden)

    Natalia González

    Full Text Available Skeletal muscle regeneration and long term maintenance is directly link to the balance between self-renewal and differentiation of resident adult stem cells known as satellite cells. In turn, satellite cell fate is influenced by a functional interaction between the transcription factor Pax7 and members of the MyoD family of muscle regulatory factors. Thus, changes in the Pax7-to-MyoD protein ratio may act as a molecular rheostat fine-tuning acquisition of lineage identity while preventing precocious terminal differentiation. Pax7 is expressed in quiescent and proliferating satellite cells, while its levels decrease sharply in differentiating progenitors Pax7 is maintained in cells (reacquiring quiescence. While the mechanisms regulating Pax7 levels based on differentiation status are not well understood, we have recently described that Pax7 levels are directly regulated by the ubiquitin-ligase Nedd4, thus promoting proteasome-dependent Pax7 degradation in differentiating satellite cells. Here we show that Pax7 levels are maintained in proliferating muscle progenitors by a mechanism involving casein kinase 2-dependent Pax7 phosphorylation at S201. Point mutations preventing S201 phosphorylation or casein kinase 2 inhibition result in decreased Pax7 protein in proliferating muscle progenitors. Accordingly, this correlates directly with increased Pax7 ubiquitination. Finally, Pax7 down regulation induced by casein kinase 2 inhibition results in precocious myogenic induction, indicating early commitment to terminal differentiation. These observations highlight the critical role of post translational regulation of Pax7 as a molecular switch controlling muscle progenitor fate.

  7. Identification and Characterization of Mouse Otic Sensory Lineage Genes

    Directory of Open Access Journals (Sweden)

    Byron H. Hartman

    2015-03-01

    Full Text Available Vertebrate embryogenesis gives rise to all cell types of an organism through the development of many unique lineages derived from the three primordial germ layers. The otic sensory lineage arises from the otic vesicle, a structure formed through invagination of placodal non-neural ectoderm. This developmental lineage possesses unique differentiation potential, giving rise to otic sensory cell populations including hair cells, supporting cells, and ganglion neurons of the auditory and vestibular organs. Here we present a systematic approach to identify transcriptional features that distinguish the otic sensory lineage (from early otic progenitors to otic sensory populations from other major lineages of vertebrate development. We used a microarray approach to analyze otic sensory lineage populations including microdissected otic vesicles (embryonic day 10.5 as well as isolated neonatal cochlear hair cells and supporting cells at postnatal day 3. Non-otic tissue samples including periotic tissues and whole embryos with otic regions removed were used as reference populations to evaluate otic specificity. Otic populations shared transcriptome-wide correlations in expression profiles that distinguish members of this lineage from non-otic populations. We further analyzed the microarray data using comparative and dimension reduction methods to identify individual genes that are specifically expressed in the otic sensory lineage. This analysis identified and ranked top otic sensory lineage-specific transcripts including Fbxo2, Col9a2, and Oc90, and additional novel otic lineage markers. To validate these results we performed expression analysis on select genes using immunohistochemistry and in situ hybridization. Fbxo2 showed the most striking pattern of specificity to the otic sensory lineage, including robust expression in the early otic vesicle and sustained expression in prosensory progenitors and auditory and vestibular hair cells and supporting

  8. Mouse prenatal platelet-forming lineages share a core transcriptional program but divergent dependence on MPL.

    Science.gov (United States)

    Potts, Kathryn S; Sargeant, Tobias J; Dawson, Caleb A; Josefsson, Emma C; Hilton, Douglas J; Alexander, Warren S; Taoudi, Samir

    2015-08-06

    The thrombopoietic environment of the neonate is established during prenatal life; therefore, a comprehensive understanding of platelet-forming cell development during embryogenesis is critical to understanding the etiology of early-onset thrombocytopenia. The recent discovery that the first platelet-forming cells of the conceptus are not megakaryocytes (MKs) but diploid platelet-forming cells (DPFCs) revealed a previously unappreciated complexity in thrombopoiesis. This raises important questions, including the following. When do conventional MKs appear? Do pathogenic genetic lesions of adult MKs affect DPFCs? What role does myeloproliferative leukemia virus (MPL), a key regulator of adult megakaryopoiesis, play in prenatal platelet-forming lineages? We performed a comprehensive study to determine the spatial and temporal appearance of prenatal platelet-forming lineages. We demonstrate that DPFCs originate in the yolk sac and then rapidly migrate to other extra- and intraembryonic tissues. Using gene disruption models of Gata1 and Nfe2, we demonstrate that perturbing essential adult MK genes causes an analogous phenotype in the early embryo before the onset of hematopoietic stem/progenitor cell-driven (definitive) hematopoiesis. Finally, we present the surprising finding that DPFC and MK commitment from their respective precursors is MPL independent in vivo but that completion of MK differentiation and establishment of the prenatal platelet mass is dependent on MPL expression. © 2015 by The American Society of Hematology.

  9. Feedback, Lineages and Self-Organizing Morphogenesis.

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    Sameeran Kunche

    2016-03-01

    Full Text Available Feedback regulation of cell lineage progression plays an important role in tissue size homeostasis, but whether such feedback also plays an important role in tissue morphogenesis has yet to be explored. Here we use mathematical modeling to show that a particular feedback architecture in which both positive and negative diffusible signals act on stem and/or progenitor cells leads to the appearance of bistable or bi-modal growth behaviors, ultrasensitivity to external growth cues, local growth-driven budding, self-sustaining elongation, and the triggering of self-organization in the form of lamellar fingers. Such behaviors arise not through regulation of cell cycle speeds, but through the control of stem or progenitor self-renewal. Even though the spatial patterns that arise in this setting are the result of interactions between diffusible factors with antagonistic effects, morphogenesis is not the consequence of Turing-type instabilities.

  10. Feedback, Lineages and Self-Organizing Morphogenesis

    Science.gov (United States)

    Calof, Anne L.; Lowengrub, John S.; Lander, Arthur D.

    2016-01-01

    Feedback regulation of cell lineage progression plays an important role in tissue size homeostasis, but whether such feedback also plays an important role in tissue morphogenesis has yet to be explored. Here we use mathematical modeling to show that a particular feedback architecture in which both positive and negative diffusible signals act on stem and/or progenitor cells leads to the appearance of bistable or bi-modal growth behaviors, ultrasensitivity to external growth cues, local growth-driven budding, self-sustaining elongation, and the triggering of self-organization in the form of lamellar fingers. Such behaviors arise not through regulation of cell cycle speeds, but through the control of stem or progenitor self-renewal. Even though the spatial patterns that arise in this setting are the result of interactions between diffusible factors with antagonistic effects, morphogenesis is not the consequence of Turing-type instabilities. PMID:26989903

  11. Stress, glucocorticoid hormones, and hippocampal neural progenitor cells: implications to mood disorders.

    Science.gov (United States)

    Kino, Tomoshige

    2015-01-01

    The hypothalamic-pituitary-adrenal (HPA) axis and its end-effectors glucocorticoid hormones play central roles in the adaptive response to numerous stressors that can be either internal or external. Thus, this system has a strong impact on the brain hippocampus and its major functions, such as cognition, memory as well as behavior, and mood. The hippocampal area of the adult brain contains neural stem cells or more committed neural progenitor cells, which retain throughout the human life the ability of self-renewal and to differentiate into multiple neural cell lineages, such as neurons, astrocytes, and oligodendrocytes. Importantly, these characteristic cells contribute significantly to the above-indicated functions of the hippocampus, while various stressors and glucocorticoids influence proliferation, differentiation, and fate of these cells. This review offers an overview of the current understanding on the interactions between the HPA axis/glucocorticoid stress-responsive system and hippocampal neural progenitor cells by focusing on the actions of glucocorticoids. Also addressed is a further discussion on the implications of such interactions to the pathophysiology of mood disorders.

  12. Vsx2 in the zebrafish retina: restricted lineages through derepression

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    Higashijima Shin-ichi

    2009-04-01

    Full Text Available Abstract Background The neurons in the vertebrate retina arise from multipotent retinal progenitor cells (RPCs. It is not clear, however, which progenitors are multipotent or why they are multipotent. Results In this study we show that the homeodomain transcription factor Vsx2 is initially expressed throughout the retinal epithelium, but later it is downregulated in all but a minor population of bipolar cells and all Müller glia. The Vsx2-negative daughters of Vsx2-positive RPCs divide and give rise to all other cell types in the retina. Vsx2 is a repressor whose targets include transcription factors such as Vsx1, which is expressed in the progenitors of distinct non-Vsx2 bipolars, and the basic helix-loop-helix transcription factor Ath5, which restricts the fate of progenitors to retinal ganglion cells, horizontal cells, amacrine cells and photoreceptors fates. Foxn4, expressed in the progenitors of amacrine and horizontal cells, is also negatively regulated by Vsx2. Conclusion Our data thus suggest Vsx2-positive RPCs are fully multipotent retinal progenitors and that when Vsx2 is downregulated, Vsx2-negative progenitors escape Vsx2 repression and so are able to express factors that restrict lineage potential.

  13. Polycomb enables primitive endoderm lineage priming in embryonic stem cells

    DEFF Research Database (Denmark)

    Illingworth, Robert S; Hölzenspies, Jurriaan J; Roske, Fabian V

    2016-01-01

    Mouse embryonic stem cells (ESCs), like the blastocyst from which they are derived, contain precursors of the epiblast (Epi) and primitive endoderm (PrEn) lineages. While transient in vivo, these precursor populations readily interconvert in vitro. We show that altered transcription is the driver...... polycomb with dynamic changes in transcription and stalled lineage commitment, allowing cells to explore alternative choices prior to a definitive decision....

  14. Reporter-Based Isolation of Developmental Myogenic Progenitors

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    Eyemen Kheir

    2018-04-01

    Full Text Available The formation and activity of mammalian tissues entail finely regulated processes, involving the concerted organization and interaction of multiple cell types. In recent years the prospective isolation of distinct progenitor and stem cell populations has become a powerful tool in the hands of developmental biologists and has rendered the investigation of their intrinsic properties possible. In this protocol, we describe how to purify progenitors with different lineage history and degree of differentiation from embryonic and fetal skeletal muscle by fluorescence-activated cell sorting (FACS. The approach takes advantage of a panel of murine strains expressing fluorescent reporter genes specifically in the myogenic progenitors. We provide a detailed description of the dissection procedures and of the enzymatic dissociation required to maximize the yield of mononucleated cells for subsequent FACS-based purification. The procedure takes ~6–7 h to complete and allows for the isolation and the subsequent molecular and phenotypic characterization of developmental myogenic progenitors.

  15. The influence of gender- and age-related differences in the radiosensitivity of hematopoietic progenitor cells detected in steady-state human peripheral blood

    International Nuclear Information System (INIS)

    Kato, Kengo; Kashiwakura, Ikuo; Kuwabara, Mikinori

    2011-01-01

    To investigate the importance of gender and aging on the individual radiosensitivity of lineage-committed myeloid hematopoietic stem/progenitor cells (HSPCs) detected in mononuclear cells (MNCs) of steady-state human peripheral blood (PB), the clonogenic survival of HPCs, including colony-forming unit-granulocyte macrophage; burst-forming unit-erythroid; colony-forming unit-granulocyte-erythroid-macrophage-megakaryocyte cells derived from MNCs exposed to 0.5 Gy and 2 Gy X-irradiation were estimated. MNCs were prepared from the buffy-coats of 59 healthy individual blood donors. The results showed that large individual differences exist in the number of HSPCs, as well as in the surviving fraction of cells. Furthermore, the number of progenitor cells strongly correlated with their surviving fraction, suggesting that the radiosensitivity of hematopoietic progenitor cells decreases with the number of cells in the 10 5 cells population. A statistically significant negative correlation was observed between the surviving fraction observed at a dose of 0.5 Gy and the age of an individual, however, none of these correlations were observed after 2 Gy irradiation. No statistically significant difference was observed in individual radiosensitivity between males and females at either radiation dose. The present results indicated a correlation between the individual responsiveness of HSPCs to ionizing irradiation, especially to low dose irradiation, and aging. (author)

  16. Lhx2 expression promotes self-renewal of a distinct multipotential hematopoietic progenitor cell in embryonic stem cell-derived embryoid bodies.

    Directory of Open Access Journals (Sweden)

    Lina Dahl

    Full Text Available The molecular mechanisms regulating the expansion of the hematopoietic system including hematopoietic stem cells (HSCs in the fetal liver during embryonic development are largely unknown. The LIM-homeobox gene Lhx2 is a candidate regulator of fetal hematopoiesis since it is expressed in the fetal liver and Lhx2(-/- mice die in utero due to severe anemia. Moreover, expression of Lhx2 in embryonic stem (ES cell-derived embryoid bodies (EBs can lead to the generation of HSC-like cell lines. To further define the role of this transcription factor in hematopoietic regulation, we generated ES cell lines that enabled tet-inducible expression of Lhx2. Using this approach we observed that Lhx2 expression synergises with specific signalling pathways, resulting in increased frequency of colony forming cells in developing EB cells. The increase in growth factor-responsive progenitor cells directly correlates to the efficiency in generating HSC-like cell lines, suggesting that Lhx2 expression induce self-renewal of a distinct multipotential hematopoietic progenitor cell in EBs. Signalling via the c-kit tyrosine kinase receptor and the gp130 signal transducer by IL-6 is necessary and sufficient for the Lhx2 induced self-renewal. While inducing self-renewal of multipotential progenitor cells, expression of Lhx2 inhibited proliferation of primitive erythroid precursor cells and interfered with early ES cell commitment, indicating striking lineage specificity of this effect.

  17. Amplification of neural stem cell proliferation by intermediate progenitor cells in Drosophila brain development

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    Bello Bruno C

    2008-02-01

    Full Text Available Abstract Background In the mammalian brain, neural stem cells divide asymmetrically and often amplify the number of progeny they generate via symmetrically dividing intermediate progenitors. Here we investigate whether specific neural stem cell-like neuroblasts in the brain of Drosophila might also amplify neuronal proliferation by generating symmetrically dividing intermediate progenitors. Results Cell lineage-tracing and genetic marker analysis show that remarkably large neuroblast lineages exist in the dorsomedial larval brain of Drosophila. These lineages are generated by brain neuroblasts that divide asymmetrically to self renew but, unlike other brain neuroblasts, do not segregate the differentiating cell fate determinant Prospero to their smaller daughter cells. These daughter cells continue to express neuroblast-specific molecular markers and divide repeatedly to produce neural progeny, demonstrating that they are proliferating intermediate progenitors. The proliferative divisions of these intermediate progenitors have novel cellular and molecular features; they are morphologically symmetrical, but molecularly asymmetrical in that key differentiating cell fate determinants are segregated into only one of the two daughter cells. Conclusion Our findings provide cellular and molecular evidence for a new mode of neurogenesis in the larval brain of Drosophila that involves the amplification of neuroblast proliferation through intermediate progenitors. This type of neurogenesis bears remarkable similarities to neurogenesis in the mammalian brain, where neural stem cells as primary progenitors amplify the number of progeny they generate through generation of secondary progenitors. This suggests that key aspects of neural stem cell biology might be conserved in brain development of insects and mammals.

  18. Genome-Nuclear Lamina Interactions Regulate Cardiac Stem Cell Lineage Restriction.

    Science.gov (United States)

    Poleshko, Andrey; Shah, Parisha P; Gupta, Mudit; Babu, Apoorva; Morley, Michael P; Manderfield, Lauren J; Ifkovits, Jamie L; Calderon, Damelys; Aghajanian, Haig; Sierra-Pagán, Javier E; Sun, Zheng; Wang, Qiaohong; Li, Li; Dubois, Nicole C; Morrisey, Edward E; Lazar, Mitchell A; Smith, Cheryl L; Epstein, Jonathan A; Jain, Rajan

    2017-10-19

    Progenitor cells differentiate into specialized cell types through coordinated expression of lineage-specific genes and modification of complex chromatin configurations. We demonstrate that a histone deacetylase (Hdac3) organizes heterochromatin at the nuclear lamina during cardiac progenitor lineage restriction. Specification of cardiomyocytes is associated with reorganization of peripheral heterochromatin, and independent of deacetylase activity, Hdac3 tethers peripheral heterochromatin containing lineage-relevant genes to the nuclear lamina. Deletion of Hdac3 in cardiac progenitor cells releases genomic regions from the nuclear periphery, leading to precocious cardiac gene expression and differentiation into cardiomyocytes; in contrast, restricting Hdac3 to the nuclear periphery rescues myogenesis in progenitors otherwise lacking Hdac3. Our results suggest that availability of genomic regions for activation by lineage-specific factors is regulated in part through dynamic chromatin-nuclear lamina interactions and that competence of a progenitor cell to respond to differentiation signals may depend upon coordinated movement of responding gene loci away from the nuclear periphery. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Radiosensitivity of human haematopoietic stem/progenitor cells

    International Nuclear Information System (INIS)

    Kato, Kengo; Kashiwakura, Ikuo; Omori, Atsuko

    2013-01-01

    The haematopoietic system is regenerative tissue with a high proliferative potential; therefore, haematopoietic stem cells (HSCs) are sensitive to extracellular oxidative stress caused by radiation and chemotherapeutic agents. An understanding of this issue can help predict haematopoietic recovery from radiation exposure as well as the extent of radiation damage to the haematopoietic system. In the present study, the radiosensitivity of human lineage-committed myeloid haematopoietic stem/progenitor cells (HSPCs), including colony-forming unit–granulocyte macrophage, burst-forming unit–erythroid and colony-forming unit–granulocyte–erythroid–macrophage–megakaryocyte cells, which are contained in adult individual peripheral blood (PB) and fetus/neonate placental/umbilical cord blood (CB), were studied. The PB of 59 healthy individual blood donors and the CB of 42 neonates were investigated in the present study. HSPCs prepared from PB and CB were exposed to 0.5 or 2 Gy x-irradiation. The results showed that large individual differences exist in the surviving fraction of cells. In the case of adult PB, a statistically significant negative correlation was observed between the surviving fraction observed at a dose of 0.5 Gy and the age of the blood donors; however, none of these correlations were observed after 2 Gy x-irradiation. In addition, seasonal and gender variation were observed in the surviving fraction of CB HSPCs. The present results suggest that there are large individual differences in the surviving fraction of HSPCs contained in both adult PB and fetus/neonate CB. In addition, some factors, including the gender, age and season of birth, affect the radiosensitivity of HSPCs, especially with a relatively low-dose exposure. (paper)

  20. The Cdk4-E2f1 pathway regulates early pancreas development by targeting Pdx1+ progenitors and Ngn3+ endocrine precursors

    Science.gov (United States)

    Kim, So Yoon; Rane, Sushil G.

    2011-01-01

    Cell division and cell differentiation are intricately regulated processes vital to organ development. Cyclin-dependent kinases (Cdks) are master regulators of the cell cycle that orchestrate the cell division and differentiation programs. Cdk1 is essential to drive cell division and is required for the first embryonic divisions, whereas Cdks 2, 4 and 6 are dispensable for organogenesis but vital for tissue-specific cell development. Here, we illustrate an important role for Cdk4 in regulating early pancreas development. Pancreatic development involves extensive morphogenesis, proliferation and differentiation of the epithelium to give rise to the distinct cell lineages of the adult pancreas. The cell cycle molecules that specify lineage commitment within the early pancreas are unknown. We show that Cdk4 and its downstream transcription factor E2f1 regulate mouse pancreas development prior to and during the secondary transition. Cdk4 deficiency reduces embryonic pancreas size owing to impaired mesenchyme development and fewer Pdx1+ pancreatic progenitor cells. Expression of activated Cdk4R24C kinase leads to increased Nkx2.2+ and Nkx6.1+ cells and a rise in the number and proliferation of Ngn3+ endocrine precursors, resulting in expansion of the β cell lineage. We show that E2f1 binds and activates the Ngn3 promoter to modulate Ngn3 expression levels in the embryonic pancreas in a Cdk4-dependent manner. These results suggest that Cdk4 promotes β cell development by directing E2f1-mediated activation of Ngn3 and increasing the pool of endocrine precursors, and identify Cdk4 as an important regulator of early pancreas development that modulates the proliferation potential of pancreatic progenitors and endocrine precursors. PMID:21490060

  1. Invited review: mesenchymal progenitor cells in intramuscular connective tissue development.

    Science.gov (United States)

    Miao, Z G; Zhang, L P; Fu, X; Yang, Q Y; Zhu, M J; Dodson, M V; Du, M

    2016-01-01

    The abundance and cross-linking of intramuscular connective tissue contributes to the background toughness of meat, and is thus undesirable. Connective tissue is mainly synthesized by intramuscular fibroblasts. Myocytes, adipocytes and fibroblasts are derived from a common pool of progenitor cells during the early embryonic development. It appears that multipotent mesenchymal stem cells first diverge into either myogenic or non-myogenic lineages; non-myogenic mesenchymal progenitors then develop into the stromal-vascular fraction of skeletal muscle wherein adipocytes, fibroblasts and derived mesenchymal progenitors reside. Because non-myogenic mesenchymal progenitors mainly undergo adipogenic or fibrogenic differentiation during muscle development, strengthening progenitor proliferation enhances the potential for both intramuscular adipogenesis and fibrogenesis, leading to the elevation of both marbling and connective tissue content in the resulting meat product. Furthermore, given the bipotent developmental potential of progenitor cells, enhancing their conversion to adipogenesis reduces fibrogenesis, which likely results in the overall improvement of marbling (more intramuscular adipocytes) and tenderness (less connective tissue) of meat. Fibrogenesis is mainly regulated by the transforming growth factor (TGF) β signaling pathway and its regulatory cascade. In addition, extracellular matrix, a part of the intramuscular connective tissue, provides a niche environment for regulating myogenic differentiation of satellite cells and muscle growth. Despite rapid progress, many questions remain in the role of extracellular matrix on muscle development, and factors determining the early differentiation of myogenic, adipogenic and fibrogenic cells, which warrant further studies.

  2. Competent for commitment: you've got to have heart!

    Science.gov (United States)

    Jain, Rajan; Epstein, Jonathan A

    2018-01-01

    The mature heart is composed primarily of four different cell types: cardiac myocytes, endothelium, smooth muscle, and fibroblasts. These cell types derive from pluripotent progenitors that become progressively restricted with regard to lineage potential, giving rise to multipotent cardiac progenitor cells and, ultimately, the differentiated cell types of the heart. Recent studies have begun to shed light on the defining characteristics of the intermediary cell types that exist transiently during this developmental process and the extrinsic and cell-autonomous factors that influence cardiac lineage decisions and cellular competence. This information will shape our understanding of congenital and adult cardiac disease and guide regenerative therapeutic approaches. In addition, cardiac progenitor specification can serve as a model for understanding basic mechanisms regulating the acquisition of cellular identity. In this review, we present the concept of "chromatin competence" that describes the potential for three-dimensional chromatin organization to function as the molecular underpinning of the ability of a progenitor cell to respond to inductive lineage cues and summarize recent studies advancing our understanding of cardiac cell specification, gene regulation, and chromatin organization and how they impact cardiac development. © 2018 Jain and Epstein; Published by Cold Spring Harbor Laboratory Press.

  3. Molecular dissection of prethymic progenitor entry into the T lymphocyte developmental pathway

    Energy Technology Data Exchange (ETDEWEB)

    Fung, Elizabeth-sharon [Los Alamos National Laboratory

    2008-01-01

    Notch signaling activates T lineage differentiation from hemopoietic progenitors, but relatively few regulators that initiate this program have been identified, e.g., GATA3 and T cell factor-I (TCF-1) (gene name Tcli). To identify additional regulators of T cell specification, a cDNA libnlrY from mouse Pro-T cells was screened for genes that are specifically up-regulated in intrathymic T cell precursors as compared with myeloid progenitors. Over 90 genes of interest were identified, and 35 of 44 tested were confirmed to be more highly expressed in T lineage precursors relative to precursors of B and/or myeloid lineage. To a remarkable extent, however, expression of these T lineage-enriched genes, including zinc finger transcription factor, helicase, and signaling adaptor genes, was also shared by stem cells (Lin{sup -}Sca-1{sup +}Kit{sup +}CD27{sup -}) and multipotent progenitors (Lin{sup -}Sca-l{sup +}Kit{sup +}CD27{sup +}), although down-regulated in other lineages. Thus, a major fraction of these early T lineage genes are a regulatory legacy from stem cells. The few genes sharply up-regulated between multipotent progenitors and Pro-T cell stages included those encoding transcription factors Bclllb, TCF-I (Tcli), and HEBalt, Notch target Deltexl, Deltex3L, Fkbp5, Eval, and Tmem13l. Like GATA3 and Deltexl, Bclllb, Fkbp5, and Eval were dependent on Notch/Delta signaling for induction in fetal liver precursors, but only BcIlI band HEBalt were up-regulated between the first two stages of intrathymic T cell development (double negative I and double negative 2) corresponding to T lineage specification. Bclllb was uniquely T lineage restricted and induced by NotchlDelta signaling specifically upon entry into the T lineage differentiation pathway.

  4. Lin- CD34hi CD117int/hi FcεRI+ cells in human blood constitute a rare population of mast cell progenitors.

    Science.gov (United States)

    Dahlin, Joakim S; Malinovschi, Andrei; Öhrvik, Helena; Sandelin, Martin; Janson, Christer; Alving, Kjell; Hallgren, Jenny

    2016-01-28

    Mast cells are rare tissue-resident immune cells that are involved in allergic reactions, and their numbers are increased in the lungs of asthmatics. Murine lung mast cells arise from committed bone marrow-derived progenitors that enter the blood circulation, migrate through the pulmonary endothelium, and mature in the tissue. In humans, mast cells can be cultured from multipotent CD34(+) progenitor cells. However, a population of distinct precursor cells that give rise to mast cells has remained undiscovered. To our knowledge, this is the first report of human lineage-negative (Lin(-)) CD34(hi) CD117(int/hi) FcεRI(+) progenitor cells, which represented only 0.0053% of the isolated blood cells in healthy individuals. These cells expressed integrin β7 and developed a mast cell-like phenotype, although with a slow cell division capacity in vitro. Isolated Lin(-) CD34(hi) CD117(int/hi) FcεRI(+) blood cells had an immature mast cell-like appearance and expressed high levels of many mast cell-related genes as compared with human blood basophils in whole-transcriptome microarray analyses. Furthermore, serglycin, tryptase, and carboxypeptidase A messenger RNA transcripts were detected by quantitative reverse transcription-polymerase chain reaction. Altogether, we propose that the Lin(-) CD34(hi) CD117(int/hi) FcεRI(+) blood cells are closely related to human tissue mast cells and likely constitute an immediate precursor population, which can give rise to predominantly mast cells. Furthermore, asthmatics with reduced lung function had a higher frequency of Lin(-) CD34(hi) CD117(int/hi) FcεRI(+) blood mast cell progenitors than asthmatics with normal lung function. © 2016 by The American Society of Hematology.

  5. Short-term, serum-free, static culture of cord blood-derived CD34+ cells: effects of FLT3-L and MIP-1alpha on in vitro expansion of hematopoietic progenitor cells.

    Science.gov (United States)

    Capmany, G; Querol, S; Cancelas, J A; García, J

    1999-08-01

    The use of ex vivo expanded cells has been suggested as a possible means to accelerate the speed of engraftment in cord blood (CB) transplantation. The aim of this study was to fix the optimal condition for the generation of committed progenitors without affecting the stem cell compartment. Analysis of the effects of FLT3-L and MIP-1alpha when combined with SCF, IL-3 and IL-6, in short-term (6 days), serum-free expansion cultures of CB-selected CD34+ cells. An important expansion was obtained that ranged between 8-15 times for CFU-GM, 21-51 times for the BFU-E/CFU-Mix population and 11 to 30 times for CD34+ cells assessed by flow cytometry. From the combinations tested, those in which FLT3-L was present had a significant increase in the expansion of committed progenitors, while the presence of MIP-1alpha had a detrimental effect on the generation of more differentiated cells. However, stem cell candidates assessed by week 5 CAFC assay could be maintained in culture when both MIP-1a and FLT3-L were present (up to 91% recovery). This culture system was also able to expand megakaryocytic precursors as determined by the co-expression of CD34 and CD61 antigens (45-70 times), in spite of the use of cytokines non-specific for the megakaryocytic lineage. The results obtained point to the combination of SCF, IL-3, IL-6, FLT3-L and MIP-1alpha as the best suited for a pre-clinical short-term serum-free static ex vivo expansion protocol of CB CD34+ cells, since it can generate large numbers of committed progenitor cells as well as maintaining week 5 CAFC.

  6. A comparative transcriptomic analysis of astrocytes differentiation from human neural progenitor cells.

    Science.gov (United States)

    Magistri, Marco; Khoury, Nathalie; Mazza, Emilia Maria Cristina; Velmeshev, Dmitry; Lee, Jae K; Bicciato, Silvio; Tsoulfas, Pantelis; Faghihi, Mohammad Ali

    2016-11-01

    Astrocytes are a morphologically and functionally heterogeneous population of cells that play critical roles in neurodevelopment and in the regulation of central nervous system homeostasis. Studies of human astrocytes have been hampered by the lack of specific molecular markers and by the difficulties associated with purifying and culturing astrocytes from adult human brains. Human neural progenitor cells (NPCs) with self-renewal and multipotent properties represent an appealing model system to gain insight into the developmental genetics and function of human astrocytes, but a comprehensive molecular characterization that confirms the validity of this cellular system is still missing. Here we used an unbiased transcriptomic analysis to characterize in vitro culture of human NPCs and to define the gene expression programs activated during the differentiation of these cells into astrocytes using FBS or the combination of CNTF and BMP4. Our results demonstrate that in vitro cultures of human NPCs isolated during the gliogenic phase of neurodevelopment mainly consist of radial glial cells (RGCs) and glia-restricted progenitor cells. In these cells the combination of CNTF and BMP4 activates the JAK/STAT and SMAD signaling cascades, leading to the inhibition of oligodendrocytes lineage commitment and activation of astrocytes differentiation. On the other hand, FBS-derived astrocytes have properties of reactive astrocytes. Our work suggests that in vitro culture of human NPCs represents a valuable cellular system to study human disorders characterized by impairment of astrocytes development and function. Our datasets represent an important resource for researchers studying human astrocytes development and might set the basis for the discovery of novel human-specific astrocyte markers. © 2016 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  7. Ascl1 (Mash1) lineage cells contribute to discrete cell populations in CNS architecture.

    Science.gov (United States)

    Kim, Euiseok J; Battiste, James; Nakagawa, Yasushi; Johnson, Jane E

    2008-08-01

    Ascl1 (previously Mash1) is a bHLH transcription factor essential for neuronal differentiation and specification in the nervous system. Although it has been studied for its role in several neural lineages, the full complement of lineages arising from Ascl1 progenitor cells remains unknown. Using an inducible Cre-flox genetic fate-mapping strategy, Ascl1 lineages were determined throughout the brain. Ascl1 is present in proliferating progenitor cells but these cells are actively differentiating as evidenced by rapid migration out of germinal zones. Ascl1 lineage cells contribute to distinct cell types in each major brain division: the forebrain including the cerebral cortex, olfactory bulb, hippocampus, striatum, hypothalamus, and thalamic nuclei, the midbrain including superior and inferior colliculi, and the hindbrain including Purkinje and deep cerebellar nuclei cells and cells in the trigeminal sensory system. Ascl1 progenitor cells at early stages in each CNS region preferentially become neurons, and at late stages they become oligodendrocytes. In conclusion, Ascl1-expressing progenitor cells in the brain give rise to multiple, but not all, neuronal subtypes and oligodendrocytes depending on the temporal and spatial context, consistent with a broad role in neural differentiation with some subtype specification.

  8. Enhancement of myocardial regeneration through genetic engineering of cardiac progenitor cells expressing Pim-1 kinase.

    Science.gov (United States)

    Fischer, Kimberlee M; Cottage, Christopher T; Wu, Weitao; Din, Shabana; Gude, Natalie A; Avitabile, Daniele; Quijada, Pearl; Collins, Brett L; Fransioli, Jenna; Sussman, Mark A

    2009-11-24

    Despite numerous studies demonstrating the efficacy of cellular adoptive transfer for therapeutic myocardial regeneration, problems remain for donated cells with regard to survival, persistence, engraftment, and long-term benefits. This study redresses these concerns by enhancing the regenerative potential of adoptively transferred cardiac progenitor cells (CPCs) via genetic engineering to overexpress Pim-1, a cardioprotective kinase that enhances cell survival and proliferation. Intramyocardial injections of CPCs overexpressing Pim-1 were given to infarcted female mice. Animals were monitored over 4, 12, and 32 weeks to assess cardiac function and engraftment of Pim-1 CPCs with echocardiography, in vivo hemodynamics, and confocal imagery. CPCs overexpressing Pim-1 showed increased proliferation and expression of markers consistent with cardiogenic lineage commitment after dexamethasone exposure in vitro. Animals that received CPCs overexpressing Pim-1 also produced greater levels of cellular engraftment, persistence, and functional improvement relative to control CPCs up to 32 weeks after delivery. Salutary effects include reduction of infarct size, greater number of c-kit(+) cells, and increased vasculature in the damaged region. Myocardial repair is significantly enhanced by genetic engineering of CPCs with Pim-1 kinase. Ex vivo gene delivery to enhance cellular survival, proliferation, and regeneration may overcome current limitations of stem cell-based therapeutic approaches.

  9. The differentiation of embryonic stem cells seeded on electrospun nanofibers into neural lineages.

    Science.gov (United States)

    Xie, Jingwei; Willerth, Stephanie M; Li, Xiaoran; Macewan, Matthew R; Rader, Allison; Sakiyama-Elbert, Shelly E; Xia, Younan

    2009-01-01

    Due to advances in stem cell biology, embryonic stem (ES) cells can be induced to differentiate into a particular mature cell lineage when cultured as embryoid bodies. Although transplantation of ES cells-derived neural progenitor cells has been demonstrated with some success for either spinal cord injury repair in small animal model, control of ES cell differentiation into complex, viable, higher ordered tissues is still challenging. Mouse ES cells have been induced to become neural progenitors by adding retinoic acid to embryoid body cultures for 4 days. In this study, we examine the use of electrospun biodegradable polymers as scaffolds not only for enhancing the differentiation of mouse ES cells into neural lineages but also for promoting and guiding the neurite outgrowth. A combination of electrospun fiber scaffolds and ES cells-derived neural progenitor cells could lead to the development of a better strategy for nerve injury repair.

  10. Cell lineage analysis of the mammalian female germline.

    Directory of Open Access Journals (Sweden)

    Yitzhak Reizel

    Full Text Available Fundamental aspects of embryonic and post-natal development, including maintenance of the mammalian female germline, are largely unknown. Here we employ a retrospective, phylogenetic-based method for reconstructing cell lineage trees utilizing somatic mutations accumulated in microsatellites, to study female germline dynamics in mice. Reconstructed cell lineage trees can be used to estimate lineage relationships between different cell types, as well as cell depth (number of cell divisions since the zygote. We show that, in the reconstructed mouse cell lineage trees, oocytes form clusters that are separate from hematopoietic and mesenchymal stem cells, both in young and old mice, indicating that these populations belong to distinct lineages. Furthermore, while cumulus cells sampled from different ovarian follicles are distinctly clustered on the reconstructed trees, oocytes from the left and right ovaries are not, suggesting a mixing of their progenitor pools. We also observed an increase in oocyte depth with mouse age, which can be explained either by depth-guided selection of oocytes for ovulation or by post-natal renewal. Overall, our study sheds light on substantial novel aspects of female germline preservation and development.

  11. Pancreas lineage allocation and specification are regulated by sphingosine-1-phosphate signalling

    Science.gov (United States)

    Serafimidis, Ioannis; Rodriguez-Aznar, Eva; Lesche, Mathias; Yoshioka, Kazuaki; Takuwa, Yoh; Dahl, Andreas; Pan, Duojia; Gavalas, Anthony

    2017-01-01

    During development, progenitor expansion, lineage allocation, and implementation of differentiation programs need to be tightly coordinated so that different cell types are generated in the correct numbers for appropriate tissue size and function. Pancreatic dysfunction results in some of the most debilitating and fatal diseases, including pancreatic cancer and diabetes. Several transcription factors regulating pancreas lineage specification have been identified, and Notch signalling has been implicated in lineage allocation, but it remains unclear how these processes are coordinated. Using a combination of genetic approaches, organotypic cultures of embryonic pancreata, and genomics, we found that sphingosine-1-phosphate (S1p), signalling through the G protein coupled receptor (GPCR) S1pr2, plays a key role in pancreas development linking lineage allocation and specification. S1pr2 signalling promotes progenitor survival as well as acinar and endocrine specification. S1pr2-mediated stabilisation of the yes-associated protein (YAP) is essential for endocrine specification, thus linking a regulator of progenitor growth with specification. YAP stabilisation and endocrine cell specification rely on Gαi subunits, revealing an unexpected specificity of selected GPCR intracellular signalling components. Finally, we found that S1pr2 signalling posttranscriptionally attenuates Notch signalling levels, thus regulating lineage allocation. Both S1pr2-mediated YAP stabilisation and Notch attenuation are necessary for the specification of the endocrine lineage. These findings identify S1p signalling as a novel key pathway coordinating cell survival, lineage allocation, and specification and linking these processes by regulating YAP levels and Notch signalling. Understanding lineage allocation and specification in the pancreas will shed light in the origins of pancreatic diseases and may suggest novel therapeutic approaches. PMID:28248965

  12. Postmarket Requirements and Commitments

    Data.gov (United States)

    U.S. Department of Health & Human Services — Provides information to the public on postmarket requirements and commitments. The phrase postmarket requirements and commitments refers to studies and clinical...

  13. Career Commitment in Nursing.

    Science.gov (United States)

    Gardner, Diane L.

    1992-01-01

    A longitudinal, repeated-measures descriptive survey used to measure career commitment and its relationship to turnover and work performance in 320 newly employed registered nurses at one hospital found that career commitment is not a stable phenomenon. The direct association between career commitment and turnover and with job performance is weak.…

  14. Small Business Commitment | NREL

    Science.gov (United States)

    Small Business Commitment Small Business Commitment Central to NREL's mission is our commitment to small business through a comprehensive and mature outreach program that combines proven techniques with the latest technology and best business practices. For More Information Contact Us Please email Rexann

  15. Practical Relativistic Bit Commitment

    NARCIS (Netherlands)

    Lunghi, T.; Kaniewski, J.; Bussières, F.; Houlmann, R.; Tomamichel, M.; Wehner, S.D.C.; Zbinden, H

    2015-01-01

    Bit commitment is a fundamental cryptographic primitive in which Alice wishes to commit a secret bit to Bob. Perfectly secure bit commitment between two mistrustful parties is impossible through an asynchronous exchange of quantum information. Perfect security is, however, possible when Alice and

  16. Omega 3 fatty acids reduce myeloid progenitor cell frequency in the bone marrow of mice and promote progenitor cell differentiation

    Directory of Open Access Journals (Sweden)

    Sollars Vincent E

    2009-03-01

    Full Text Available Abstract Background Omega 3 fatty acids have been found to inhibit proliferation, induce apoptosis, and promote differentiation in various cell types. The processes of cell survival, expansion, and differentiation are of key importance in the regulation of hematopoiesis. We investigated the role of omega 3 fatty acids in controlling the frequency of various myeloid progenitor cells in the bone marrow of mice. Increased progenitor cell frequency and blocked differentiation are characteristics of hematopoietic disorders of the myeloid lineage, such as myeloproliferative diseases and myeloid leukemias. Results We found that increasing the proportion of omega 3 fatty acids relative to the proportion of omega 6 fatty acids in the diet caused increased differentiation and reduced the frequency of myeloid progenitor cells in the bone marrow of mice. Furthermore, this had no adverse effect on peripheral white blood cell counts. Conclusion Our results indicate that omega 3 fatty acids impact hematopoietic differentiation by reducing myeloid progenitor cell frequency in the bone marrow and promoting progenitor cell differentiation. Further exploration of this discovery could lead to the use of omega 3 fatty acids as a therapeutic option for patients that have various disorders of hematopoiesis.

  17. Itga2b regulation at the onset of definitive hematopoiesis and commitment to differentiation.

    Directory of Open Access Journals (Sweden)

    Stephanie Dumon

    Full Text Available Product of the Itga2b gene, CD41 contributes to hematopoietic stem cell (HSC and megakaryocyte/platelet functions. CD41 expression marks the onset of definitive hematopoiesis in the embryo where it participates in regulating the numbers of multipotential progenitors. Key to platelet aggregation, CD41 expression also characterises their precursor, the megakaryocyte, and is specifically up regulated during megakaryopoiesis. Though phenotypically unique, megakaryocytes and HSC share numerous features, including key transcription factors, which could indicate common sub-regulatory networks. In these respects, Itga2b can serve as a paradigm to study features of both developmental-stage and HSC- versus megakaryocyte-specific regulations. By comparing different cellular contexts, we highlight a mechanism by which internal promoters participate in Itga2b regulation. A developmental process connects epigenetic regulation and promoter switching leading to CD41 expression in HSC. Interestingly, a similar process can be observed at the Mpl locus, which codes for another receptor that defines both HSC and megakaryocyte identities. Our study shows that Itga2b expression is controlled by lineage-specific networks and associates with H4K8ac in megakaryocyte or H3K27me3 in the multipotential hematopoietic cell line HPC7. Correlating with the decrease in H3K27me3 at the Itga2b Iocus, we find that following commitment to megakaryocyte differentiation, the H3K27 demethylase Jmjd3 up-regulation influences both Itga2b and Mpl expression.

  18. Nigral dopaminergic neuron replenishment in adult mice through VE-cadherin-expressing neural progenitor cells

    Directory of Open Access Journals (Sweden)

    Abir A Rahman

    2017-01-01

    Full Text Available The function of dopaminergic neurons in the substantia nigra is of central importance to the coordination of movement by the brain's basal ganglia circuitry. This is evidenced by the loss of these neurons, resulting in the cardinal motor deficits associated with Parkinson's disease. In order to fully understand the physiology of these key neurons and develop potential therapies for their loss, it is essential to determine if and how dopaminergic neurons are replenished in the adult brain. Recent work has presented evidence for adult neurogenesis of these neurons by Nestin+/Sox2– neural progenitor cells. We sought to further validate this finding and explore a potential atypical origin for these progenitor cells. Since neural progenitor cells have a proximal association with the vasculature of the brain and subsets of endothelial cells are Nestin+, we hypothesized that dopaminergic neural progenitors might share a common cell lineage. Therefore, we employed a VE-cadherin promoter-driven CREERT2:THlox/THlox transgenic mouse line to ablate the tyrosine hydroxylase gene from endothelial cells in adult animals. After 26 weeks, but not 13 weeks, following the genetic blockade of tyrosine hydroxylase expression in VE-cadherin+ cells, we observed a significant reduction in tyrosine hydroxylase+ neurons in the substantia nigra. The results from this genetic lineage tracing study suggest that dopaminergic neurons are replenished in adult mice by a VE-cadherin+ progenitor cell population potentially arising from an endothelial lineage.

  19. Developmental origin and lineage plasticity of endogenous cardiac stem cells

    Science.gov (United States)

    Santini, Maria Paola; Forte, Elvira; Harvey, Richard P.; Kovacic, Jason C.

    2016-01-01

    Over the past two decades, several populations of cardiac stem cells have been described in the adult mammalian heart. For the most part, however, their lineage origins and in vivo functions remain largely unexplored. This Review summarizes what is known about different populations of embryonic and adult cardiac stem cells, including KIT+, PDGFRα+, ISL1+ and SCA1+ cells, side population cells, cardiospheres and epicardial cells. We discuss their developmental origins and defining characteristics, and consider their possible contribution to heart organogenesis and regeneration. We also summarize the origin and plasticity of cardiac fibroblasts and circulating endothelial progenitor cells, and consider what role these cells have in contributing to cardiac repair. PMID:27095490

  20. Progenitors of white dwarfs

    International Nuclear Information System (INIS)

    Drilling, J.S.; Schoenberner, D.

    1985-01-01

    Direct observational evidence is presented which indicates that the immediate progenitors of white dwarfs are the central stars of planetary nebulae (approximately 70%), other post-AGB objects (approximately 30%), and post-HB objects not massive enough to climb the AGB (approximately 0.3%). The combined birth rate for these objects is in satisfactory agreement with the death rate of main-sequence stars and the birth rate of white dwarfs

  1. 3-dimensional examination of the adult mouse subventricular zone reveals lineage-specific microdomains.

    Science.gov (United States)

    Azim, Kasum; Fiorelli, Roberto; Zweifel, Stefan; Hurtado-Chong, Anahi; Yoshikawa, Kazuaki; Slomianka, Lutz; Raineteau, Olivier

    2012-01-01

    Recent studies suggest that the subventricular zone (SVZ) of the lateral ventricle is populated by heterogeneous populations of stem and progenitor cells that, depending on their exact location, are biased to acquire specific neuronal fates. This newly described heterogeneity of SVZ stem and progenitor cells underlines the necessity to develop methods for the accurate quantification of SVZ stem and progenitor subpopulations. In this study, we provide 3-dimensional topographical maps of slow cycling "stem" cells and progenitors based on their unique cell cycle properties. These maps revealed that both cell populations are present throughout the lateral ventricle wall as well as in discrete regions of the dorsal wall. Immunodetection of transcription factors expressed in defined progenitor populations further reveals that divergent lineages have clear regional enrichments in the rostro-caudal as well as in the dorso-ventral span of the lateral ventricle. Thus, progenitors expressing Tbr2 and Dlx2 were confined to dorsal and dorso-lateral regions of the lateral ventricle, respectively, while Mash1+ progenitors were more homogeneously distributed. All cell populations were enriched in the rostral-most region of the lateral ventricle. This diversity and uneven distribution greatly impede the accurate quantification of SVZ progenitor populations. This is illustrated by measuring the coefficient of error of estimates obtained by using increasing section sampling interval. Based on our empirical data, we provide such estimates for all progenitor populations investigated in this study. These can be used in future studies as guidelines to judge if the precision obtained with a sampling scheme is sufficient to detect statistically significant differences between experimental groups if a biological effect is present. Altogether, our study underlines the need to consider the SVZ of the lateral ventricle as a complex 3D structure and define methods to accurately assess neural

  2. 3-dimensional examination of the adult mouse subventricular zone reveals lineage-specific microdomains.

    Directory of Open Access Journals (Sweden)

    Kasum Azim

    Full Text Available Recent studies suggest that the subventricular zone (SVZ of the lateral ventricle is populated by heterogeneous populations of stem and progenitor cells that, depending on their exact location, are biased to acquire specific neuronal fates. This newly described heterogeneity of SVZ stem and progenitor cells underlines the necessity to develop methods for the accurate quantification of SVZ stem and progenitor subpopulations. In this study, we provide 3-dimensional topographical maps of slow cycling "stem" cells and progenitors based on their unique cell cycle properties. These maps revealed that both cell populations are present throughout the lateral ventricle wall as well as in discrete regions of the dorsal wall. Immunodetection of transcription factors expressed in defined progenitor populations further reveals that divergent lineages have clear regional enrichments in the rostro-caudal as well as in the dorso-ventral span of the lateral ventricle. Thus, progenitors expressing Tbr2 and Dlx2 were confined to dorsal and dorso-lateral regions of the lateral ventricle, respectively, while Mash1+ progenitors were more homogeneously distributed. All cell populations were enriched in the rostral-most region of the lateral ventricle. This diversity and uneven distribution greatly impede the accurate quantification of SVZ progenitor populations. This is illustrated by measuring the coefficient of error of estimates obtained by using increasing section sampling interval. Based on our empirical data, we provide such estimates for all progenitor populations investigated in this study. These can be used in future studies as guidelines to judge if the precision obtained with a sampling scheme is sufficient to detect statistically significant differences between experimental groups if a biological effect is present. Altogether, our study underlines the need to consider the SVZ of the lateral ventricle as a complex 3D structure and define methods to

  3. Functional Characterization of DNA Methylation in the Oligodendrocyte Lineage

    Directory of Open Access Journals (Sweden)

    Sarah Moyon

    2016-04-01

    Full Text Available Oligodendrocytes derive from progenitors (OPCs through the interplay of epigenomic and transcriptional events. By integrating high-resolution methylomics, RNA-sequencing, and multiple transgenic lines, this study defines the role of DNMT1 in developmental myelination. We detected hypermethylation of genes related to cell cycle and neurogenesis during differentiation of OPCs, yet genetic ablation of Dnmt1 resulted in inefficient OPC expansion and severe hypomyelination associated with ataxia and tremors in mice. This phenotype was not caused by lineage switch or massive apoptosis but was characterized by a profound defect of differentiation associated with changes in exon-skipping and intron-retention splicing events and by the activation of an endoplasmic reticulum stress response. Therefore, loss of Dnmt1 in OPCs is not sufficient to induce a lineage switch but acts as an important determinant of the coordination between RNA splicing and protein synthesis necessary for myelin formation.

  4. Multipotent embryonic isl1+ progenitor cells lead to cardiac, smooth muscle, and endothelial cell diversification.

    Science.gov (United States)

    Moretti, Alessandra; Caron, Leslie; Nakano, Atsushi; Lam, Jason T; Bernshausen, Alexandra; Chen, Yinhong; Qyang, Yibing; Bu, Lei; Sasaki, Mika; Martin-Puig, Silvia; Sun, Yunfu; Evans, Sylvia M; Laugwitz, Karl-Ludwig; Chien, Kenneth R

    2006-12-15

    Cardiogenesis requires the generation of endothelial, cardiac, and smooth muscle cells, thought to arise from distinct embryonic precursors. We use genetic fate-mapping studies to document that isl1(+) precursors from the second heart field can generate each of these diverse cardiovascular cell types in vivo. Utilizing embryonic stem (ES) cells, we clonally amplified a cellular hierarchy of isl1(+) cardiovascular progenitors, which resemble the developmental precursors in the embryonic heart. The transcriptional signature of isl1(+)/Nkx2.5(+)/flk1(+) defines a multipotent cardiovascular progenitor, which can give rise to cells of all three lineages. These studies document a developmental paradigm for cardiogenesis, where muscle and endothelial lineage diversification arises from a single cell-level decision of a multipotent isl1(+) cardiovascular progenitor cell (MICP). The discovery of ES cell-derived MICPs suggests a strategy for cardiovascular tissue regeneration via their isolation, renewal, and directed differentiation into specific mature cardiac, pacemaker, smooth muscle, and endothelial cell types.

  5. Identification of Different Classes of Luminal Progenitor Cells within Prostate Tumors

    Directory of Open Access Journals (Sweden)

    Supreet Agarwal

    2015-12-01

    Full Text Available Primary prostate cancer almost always has a luminal phenotype. However, little is known about the stem/progenitor properties of transformed cells within tumors. Using the aggressive Pten/Tp53-null mouse model of prostate cancer, we show that two classes of luminal progenitors exist within a tumor. Not only did tumors contain previously described multipotent progenitors, but also a major population of committed luminal progenitors. Luminal cells, sorted directly from tumors or grown as organoids, initiated tumors of adenocarcinoma or multilineage histological phenotypes, which is consistent with luminal and multipotent differentiation potentials, respectively. Moreover, using organoids we show that the ability of luminal-committed progenitors to self-renew is a tumor-specific property, absent in benign luminal cells. Finally, a significant fraction of luminal progenitors survived in vivo castration. In all, these data reveal two luminal tumor populations with different stem/progenitor cell capacities, providing insight into prostate cancer cells that initiate tumors and can influence treatment response.

  6. Pax7 lineage contributions to the mammalian neural crest.

    Directory of Open Access Journals (Sweden)

    Barbara Murdoch

    Full Text Available Neural crest cells are vertebrate-specific multipotent cells that contribute to a variety of tissues including the peripheral nervous system, melanocytes, and craniofacial bones and cartilage. Abnormal development of the neural crest is associated with several human maladies including cleft/lip palate, aggressive cancers such as melanoma and neuroblastoma, and rare syndromes, like Waardenburg syndrome, a complex disorder involving hearing loss and pigment defects. We previously identified the transcription factor Pax7 as an early marker, and required component for neural crest development in chick embryos. In mammals, Pax7 is also thought to play a role in neural crest development, yet the precise contribution of Pax7 progenitors to the neural crest lineage has not been determined.Here we use Cre/loxP technology in double transgenic mice to fate map the Pax7 lineage in neural crest derivates. We find that Pax7 descendants contribute to multiple tissues including the cranial, cardiac and trunk neural crest, which in the cranial cartilage form a distinct regional pattern. The Pax7 lineage, like the Pax3 lineage, is additionally detected in some non-neural crest tissues, including a subset of the epithelial cells in specific organs.These results demonstrate a previously unappreciated widespread distribution of Pax7 descendants within and beyond the neural crest. They shed light regarding the regionally distinct phenotypes observed in Pax3 and Pax7 mutants, and provide a unique perspective into the potential roles of Pax7 during disease and development.

  7. Lineage fate of ductular reactions in liver injury and carcinogenesis.

    Science.gov (United States)

    Jörs, Simone; Jeliazkova, Petia; Ringelhan, Marc; Thalhammer, Julian; Dürl, Stephanie; Ferrer, Jorge; Sander, Maike; Heikenwalder, Mathias; Schmid, Roland M; Siveke, Jens T; Geisler, Fabian

    2015-06-01

    Ductular reactions (DRs) are observed in virtually all forms of human liver disease; however, the histogenesis and function of DRs in liver injury are not entirely understood. It is widely believed that DRs contain bipotential liver progenitor cells (LPCs) that serve as an emergency cell pool to regenerate both cholangiocytes and hepatocytes and may eventually give rise to hepatocellular carcinoma (HCC). Here, we used a murine model that allows highly efficient and specific lineage labeling of the biliary compartment to analyze the histogenesis of DRs and their potential contribution to liver regeneration and carcinogenesis. In multiple experimental and genetic liver injury models, biliary cells were the predominant precursors of DRs but lacked substantial capacity to produce new hepatocytes, even when liver injuries were prolonged up to 12 months. Genetic modulation of NOTCH and/or WNT/β-catenin signaling within lineage-tagged DRs impaired DR expansion but failed to redirect DRs from biliary differentiation toward the hepatocyte lineage. Further, lineage-labeled DRs did not produce tumors in genetic and chemical HCC mouse models. In summary, we found no evidence in our system to support mouse biliary-derived DRs as an LPC pool to replenish hepatocytes in a quantitatively relevant way in injury or evidence that DRs give rise to HCCs.

  8. Competence of failed endocrine progenitors to give rise to acinar but not ductal cells is restricted to early pancreas development

    OpenAIRE

    Beucher, Anthony; Martín, Mercè; Spenle, Caroline; Poulet, Martine; Collin, Caitlin; Gradwohl, Gérard

    2011-01-01

    During mouse pancreas development, the transient expression of Neurogenin3 (Neurog3) in uncommitted pancreas progenitors is required to determine endocrine destiny. However it has been reported that Neurog3-expressing cells can eventually adopt acinar or ductal fates and that Neurog3 levels were important to secure the islet destiny. It is not known whether the competence of Neurog3-induced cells to give rise to non-endocrine lineages is an intrinsic property of these progenitors or depends o...

  9. Pancreatic β-cell regeneration: Facultative or dedicated progenitors?

    Science.gov (United States)

    Afelik, Solomon; Rovira, Meritxell

    2017-04-15

    The adult pancreas is only capable of limited regeneration. Unlike highly regenerative tissues such as the skin, intestinal crypts and hematopoietic system, no dedicated adult stem cells or stem cell niche have so far been identified within the adult pancreas. New β cells have been shown to form in the adult pancreas, in response to high physiological demand or experimental β-cell ablation, mostly by replication of existing β cells. The possibility that new β cells are formed from other sources is currently a point of major controversy. Under particular injury conditions, fully differentiated pancreatic duct and acinar cells have been shown to dedifferentiate into a progenitor-like state, however the extent, to which ductal, acinar or other endocrine cells contribute to restoring pancreatic β-cell mass remains to be resolved. In this review we focus on regenerative events in the pancreas with emphasis on the restoration of β-cell mass. We present an overview of regenerative responses noted within the different pancreatic lineages, following injury. We also highlight the intrinsic plasticity of the adult pancreas that allows for inter-conversion of fully differentiated pancreatic lineages through manipulation of few genes or growth factors. Taken together, evidence from a number of studies suggest that differentiated pancreatic lineages could act as facultative progenitor cells, but the extent to which these contribute to β-cell regeneration in vivo is still a matter of contention. Copyright © 2016. Published by Elsevier B.V.

  10. Direct contact with endoderm-like cells efficiently induces cardiac progenitors from mouse and human pluripotent stem cells.

    Directory of Open Access Journals (Sweden)

    Hideki Uosaki

    Full Text Available RATIONALE: Pluripotent stem cell-derived cardiac progenitor cells (CPCs have emerged as a powerful tool to study cardiogenesis in vitro and a potential cell source for cardiac regenerative medicine. However, available methods to induce CPCs are not efficient or require high-cost cytokines with extensive optimization due to cell line variations. OBJECTIVE: Based on our in-vivo observation that early endodermal cells maintain contact with nascent pre-cardiac mesoderm, we hypothesized that direct physical contact with endoderm promotes induction of CPCs from pluripotent cells. METHOD AND RESULT: To test the hypothesis, we cocultured mouse embryonic stem (ES cells with the endodermal cell line End2 by co-aggregation or End2-conditioned medium. Co-aggregation resulted in strong induction of Flk1(+ PDGFRa(+ CPCs in a dose-dependent manner, but the conditioned medium did not, indicating that direct contact is necessary for this process. To determine if direct contact with End2 cells also promotes the induction of committed cardiac progenitors, we utilized several mouse ES and induced pluripotent (iPS cell lines expressing fluorescent proteins under regulation of the CPC lineage markers Nkx2.5 or Isl1. In agreement with earlier data, co-aggregation with End2 cells potently induces both Nkx2.5(+ and Isl1(+ CPCs, leading to a sheet of beating cardiomyocytes. Furthermore, co-aggregation with End2 cells greatly promotes the induction of KDR(+ PDGFRa(+ CPCs from human ES cells. CONCLUSIONS: Our co-aggregation method provides an efficient, simple and cost-effective way to induce CPCs from mouse and human pluripotent cells.

  11. Masses of supernova progenitors

    International Nuclear Information System (INIS)

    Tinsley, B.M.

    1977-01-01

    The possible nature and masses of supernovae progenitors, and the bearing of empirical results on some unsolved theoretical problems concerning the origin of supernovae, are discussed. The author concentrates on two main questions: what is the lower mass limit for stars to die explosively and what stars initiate type I supernovae. The evidence considered includes local supernova rates, empirical estimates of msub(w) (the upper mass limit for death as a white dwarf), the distributions of supernovae among stellar populations in galaxies and the colors of supernova producing galaxies. (B.D.)

  12. Regulation of Murine Natural Killer Cell Commitment

    Directory of Open Access Journals (Sweden)

    Nicholas D Huntington

    2013-01-01

    Full Text Available NK cells can derive from the same precursors as B and T cells, however to achieve lineage specificity, several transcription factors need to be activated or annulled. While a few important transcription factors have identified for NK genesis the mechanisms of how this is achieved is far from resolved. Adding to the complexity of this, NK cells are found and potentially develop in diverse locations in vivo and it remains to be addressed if a common NK cell precursor seeds diverse niches and how transcription factors may differentially regulate NK cell commitment in distinct microenvironments. Here we will summarise some recent findings in NK cell commitment and discuss how a NK cell transcriptional network might be organised, while addressing some misconceptions and anomalies along the way.

  13. NADPH Oxidase 1 Modulates WNT and NOTCH1 Signaling To Control the Fate of Proliferative Progenitor Cells in the Colon▿

    Science.gov (United States)

    Coant, Nicolas; Ben Mkaddem, Sanae; Pedruzzi, Eric; Guichard, Cécile; Tréton, Xavier; Ducroc, Robert; Freund, Jean-Noel; Cazals-Hatem, Dominique; Bouhnik, Yoram; Woerther, Paul-Louis; Skurnik, David; Grodet, Alain; Fay, Michèle; Biard, Denis; Lesuffleur, Thécla; Deffert, Christine; Moreau, Richard; Groyer, André; Krause, Karl-Heinz; Daniel, Fanny; Ogier-Denis, Eric

    2010-01-01

    The homeostatic self-renewal of the colonic epithelium requires coordinated regulation of the canonical Wnt/β-catenin and Notch signaling pathways to control proliferation and lineage commitment of multipotent stem cells. However, the molecular mechanisms by which the Wnt/β-catenin and Notch1 pathways interplay in controlling cell proliferation and fate in the colon are poorly understood. Here we show that NADPH oxidase 1 (NOX1), a reactive oxygen species (ROS)-producing oxidase that is highly expressed in colonic epithelial cells, is a pivotal determinant of cell proliferation and fate that integrates Wnt/β-catenin and Notch1 signals. NOX1-deficient mice reveal a massive conversion of progenitor cells into postmitotic goblet cells at the cost of colonocytes due to the concerted repression of phosphatidylinositol 3-kinase (PI3K)/AKT/Wnt/β-catenin and Notch1 signaling. This conversion correlates with the following: (i) the redox-dependent activation of the dual phosphatase PTEN, causing the inactivation of the Wnt pathway effector β-catenin, and (ii) the downregulation of Notch1 signaling that provokes derepression of mouse atonal homolog 1 (Math1) expression. We conclude that NOX1 controls the balance between goblet and absorptive cell types in the colon by coordinately modulating PI3K/AKT/Wnt/β-catenin and Notch1 signaling. This finding provides the molecular basis for the role of NOX1 in cell proliferation and postmitotic differentiation. PMID:20351171

  14. M-CSF improves protection against bacterial and fungal infections after hematopoietic stem/progenitor cell transplantation

    Science.gov (United States)

    Sarrazin, Sandrine; Redelberger, David

    2016-01-01

    Myeloablative treatment preceding hematopoietic stem cell (HSC) and progenitor cell (HS/PC) transplantation results in severe myeloid cytopenia and susceptibility to infections in the lag period before hematopoietic recovery. We have previously shown that macrophage colony-stimulating factor (CSF-1; M-CSF) directly instructed myeloid commitment in HSCs. In this study, we tested whether this effect had therapeutic benefit in improving protection against pathogens after HS/PC transplantation. M-CSF treatment resulted in an increased production of mature myeloid donor cells and an increased survival of recipient mice infected with lethal doses of clinically relevant opportunistic pathogens, namely the bacteria Pseudomonas aeruginosa and the fungus Aspergillus fumigatus. M-CSF treatment during engraftment or after infection efficiently protected from these pathogens as early as 3 days after transplantation and was effective as a single dose. It was more efficient than granulocyte CSF (G-CSF), a common treatment of severe neutropenia, which showed no protective effect under the tested conditions. M-CSF treatment showed no adverse effect on long-term lineage contribution or stem cell activity and, unlike G-CSF, did not impede recovery of HS/PCs, thrombocyte numbers, or glucose metabolism. These results encourage potential clinical applications of M-CSF to prevent severe infections after HS/PC transplantation. PMID:27811055

  15. PRMT5 is essential for the maintenance of chondrogenic progenitor cells in the limb bud.

    Science.gov (United States)

    Norrie, Jacqueline L; Li, Qiang; Co, Swanie; Huang, Bau-Lin; Ding, Ding; Uy, Jann C; Ji, Zhicheng; Mackem, Susan; Bedford, Mark T; Galli, Antonella; Ji, Hongkai; Vokes, Steven A

    2016-12-15

    During embryonic development, undifferentiated progenitor cells balance the generation of additional progenitor cells with differentiation. Within the developing limb, cartilage cells differentiate from mesodermal progenitors in an ordered process that results in the specification of the correct number of appropriately sized skeletal elements. The internal pathways by which these cells maintain an undifferentiated state while preserving their capacity to differentiate is unknown. Here, we report that the arginine methyltransferase PRMT5 has a crucial role in maintaining progenitor cells. Mouse embryonic buds lacking PRMT5 have severely truncated bones with wispy digits lacking joints. This novel phenotype is caused by widespread cell death that includes mesodermal progenitor cells that have begun to precociously differentiate into cartilage cells. We propose that PRMT5 maintains progenitor cells through its regulation of Bmp4 Intriguingly, adult and embryonic stem cells also require PRMT5 for maintaining pluripotency, suggesting that similar mechanisms might regulate lineage-restricted progenitor cells during organogenesis. © 2016. Published by The Company of Biologists Ltd.

  16. Enrichment of rat oligodendrocyte progenitor cells by magnetic cell sorting

    Czech Academy of Sciences Publication Activity Database

    Čížková, D.; Čížek, M.; Nagyová, M.; Slovinská, L.; Novotná, I.; Jergová, S.; Radoňák, J.; Hlučilová, Jana; Vanický, I.

    2009-01-01

    Roč. 184, č. 1 (2009), s. 88-94 ISSN 0165-0270 R&D Projects: GA MŠk MEB0808108 Grant - others:Agentúra na podporu výskumu a vývoja(SK) APVV-51002105; Agentúra na podporu výskumu a vývoja(SK) APVV SK-CZ-0045-07 Institutional research plan: CEZ:AV0Z50450515 Keywords : Oligodendrocytes progenitors Lineage * Magnetic separation Subject RIV: FH - Neurology Impact factor: 2.295, year: 2009

  17. Commitment Without Marriage

    Science.gov (United States)

    Reczek, Corinne; Elliott, Sinikka; Umberson, Debra

    2011-01-01

    The majority of Americans will marry in their lifetimes, and for many, marriage symbolizes the transition into long-term commitment. However, many Americans cannot legally marry. This article analyzes in-depth interviews with gays and lesbians in long-term partnerships to examine union formation and commitment-making histories. Using a life course perspective that emphasizes historical and biographical contexts, the authors examine how couples conceptualize and form committed relationships despite being denied the right to marry. Although previous studies suggest that commitment ceremonies are a way to form same-sex unions, this study finds that because of their unique social, historical, and biographical relationship to marriage and ceremonies, long-term same-sex couples do not follow normative commitment-making trajectories. Instead, relationships can transition more ambiguously to committed formations without marriage, public ceremony, clear-cut act, or decision. Such an understanding of commitment making outside of marriage has implications for theorizing alternative forms of union making. PMID:21814298

  18. Malware Lineage in the Wild

    OpenAIRE

    Haq, Irfan Ul; Chica, Sergio; Caballero, Juan; Jha, Somesh

    2017-01-01

    Malware lineage studies the evolutionary relationships among malware and has important applications for malware analysis. A persistent limitation of prior malware lineage approaches is to consider every input sample a separate malware version. This is problematic since a majority of malware are packed and the packing process produces many polymorphic variants (i.e., executables with different file hash) of the same malware version. Thus, many samples correspond to the same malware version and...

  19. The combination of valproic acid and lithium delays hematopoietic stem/progenitor cell differentiation

    NARCIS (Netherlands)

    Walasek, Marta A.; Bystrykh, Leonid; van den Boom, Vincent; Olthof, Sandra; Ausema, Albertina; Ritsema, Martha; Huls, Gerwin; de Haan, Gerald; van Os, Ronald

    2012-01-01

    Despite increasing knowledge on the regulation of hematopoietic stem/progenitor cell (HSPC) self-renewal and differentiation, in vitro control of stem cell fate decisions has been difficult. The ability to inhibit HSPC commitment in culture may be of benefit to cell therapy protocols. Small

  20. Alzheimer's: From Caring to Commitment

    Science.gov (United States)

    ... Current Issue Past Issues Home Current issue contents Alzheimer's: From Caring to Commitment From Caring to Commitment ... Caring to Commitment During her sister’s battle with Alzheimer’s, Anne Murphy stayed by her side and continues ...

  1. Nonstimulated human uncommitted mesenchymal stem cells express cell markers of mesenchymal and neural lineages.

    Science.gov (United States)

    Minguell, José J; Fierro, Fernando A; Epuñan, María J; Erices, Alejandro A; Sierralta, Walter D

    2005-08-01

    Ex vivo cultures of human bone marrow-derived mesenchymal stem cells (MSCs) contain subsets of progenitors exhibiting dissimilar properties. One of these subsets comprises uncommitted progenitors displaying distinctive features, such as morphology, a quiescent condition, growth factor production, and restricted tissue biodistribution after transplantation. In this study, we assessed the competence of these cells to express, in the absence of differentiation stimuli, markers of mesoderm and ectodermic (neural) cell lineages. Fluorescence microscopy analysis showed a unique pattern of expression of osteogenic, chondrogenic, muscle, and neural markers. The depicted "molecular signature" of these early uncommitted progenitors, in the absence of differentiation stimuli, is consistent with their multipotentiality and plasticity as suggested by several in vitro and in vivo studies.

  2. Single cell lineage analysis of mouse embryonic stem cells at the exit from pluripotency

    Directory of Open Access Journals (Sweden)

    Jamie Trott

    2013-08-01

    Understanding how interactions between extracellular signalling pathways and transcription factor networks influence cellular decision making will be crucial for understanding mammalian embryogenesis and for generating specialised cell types in vitro. To this end, pluripotent mouse Embryonic Stem (mES cells have proven to be a useful model system. However, understanding how transcription factors and signalling pathways affect decisions made by individual cells is confounded by the fact that measurements are generally made on groups of cells, whilst individual mES cells differentiate at different rates and towards different lineages, even in conditions that favour a particular lineage. Here we have used single-cell measurements of transcription factor expression and Wnt/β-catenin signalling activity to investigate their effects on lineage commitment decisions made by individual cells. We find that pluripotent mES cells exhibit differing degrees of heterogeneity in their expression of important regulators from pluripotency, depending on the signalling environment to which they are exposed. As mES cells differentiate, downregulation of Nanog and Oct4 primes cells for neural commitment, whilst loss of Sox2 expression primes cells for primitive streak commitment. Furthermore, we find that Wnt signalling acts through Nanog to direct cells towards a primitive streak fate, but that transcriptionally active β-catenin is associated with both neural and primitive streak commitment. These observations confirm and extend previous suggestions that pluripotency genes influence lineage commitment and demonstrate how their dynamic expression affects the direction of lineage commitment, whilst illustrating two ways in which the Wnt signalling pathway acts on this network during cell fate assignment.

  3. The role of Six1 in muscle progenitor cells and the establishment of fast-twitch muscle fibres

    OpenAIRE

    Nord, Hanna

    2014-01-01

    Myogenesis is the process of skeletal muscle tissue formation where committed muscle progenitor cells differentiate into skeletal muscle fibres. Depending on the instructive cues the muscle progenitor cells receive they will differentiate into specific fibre types with different properties. The skeletal muscle fibres can be broadly classified as fast-twitch fibres or slow-twitch fibres, based on their contractile speed. However, subgroups of fast- and slow-twitch fibres with different metabol...

  4. Can pancreatic duct-derived progenitors be a source of islet regeneration?

    International Nuclear Information System (INIS)

    Xia, Bing; Zhan, Xiao-Rong; Yi, Ran; Yang, Baofeng

    2009-01-01

    The regenerative process of the pancreas is of interest because the main pathogenesis of diabetes mellitus is an inadequate number of insulin-producing β-cells. The functional mass of β-cells is decreased in type 1 diabetes, so replacing missing β-cells or triggering their regeneration may allow for improved type 1 diabetes treatment. Therefore, expansion of the β-cell mass from endogenous sources, either in vivo or in vitro, represents an area of increasing interest. The mechanism of islet regeneration remains poorly understood, but the identification of islet progenitor sources is critical for understanding β-cell regeneration. One potential source is the islet proper, via the dedifferentiation, proliferation, and redifferentiation of facultative progenitors residing within the islet. Neogenesis, or that the new pancreatic islets can derive from progenitor cells present within the ducts has been reported, but the existence and identity of the progenitor cells have been debated. In this review, we focus on pancreatic ductal cells, which are islet progenitors capable of differentiating into islet β-cells. Islet neogenesis, seen as budding of hormone-positive cells from the ductal epithelium, is considered to be one mechanism for normal islet growth after birth and in regeneration, and has suggested the presence of pancreatic stem cells. Numerous results support the neogenesis hypothesis, the evidence for the hypothesis in the adult comes primarily from morphological studies that have in common the production of damage to all or part of the pancreas, with consequent inflammation and repair. Although numerous studies support a ductal origin for new islets after birth, lineage-tracing experiments are considered the 'gold standard' of proof. Lineage-tracing experiments show that pancreatic duct cells act as progenitors, giving rise to new islets after birth and after injury. The identification of differentiated pancreatic ductal cells as an in vivo progenitor for

  5. Can pancreatic duct-derived progenitors be a source of islet regeneration?

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Bing [Department of Endocrinology, First Hospital of Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China); Zhan, Xiao-Rong, E-mail: xiaorongzhan@sina.com [Department of Endocrinology, First Hospital of Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China); Yi, Ran [Department of Endocrinology, First Hospital of Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China); Yang, Baofeng [Department of Pharmacology, State Key Laboratory of Biomedicine and Pharmacology, Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China)

    2009-06-12

    The regenerative process of the pancreas is of interest because the main pathogenesis of diabetes mellitus is an inadequate number of insulin-producing {beta}-cells. The functional mass of {beta}-cells is decreased in type 1 diabetes, so replacing missing {beta}-cells or triggering their regeneration may allow for improved type 1 diabetes treatment. Therefore, expansion of the {beta}-cell mass from endogenous sources, either in vivo or in vitro, represents an area of increasing interest. The mechanism of islet regeneration remains poorly understood, but the identification of islet progenitor sources is critical for understanding {beta}-cell regeneration. One potential source is the islet proper, via the dedifferentiation, proliferation, and redifferentiation of facultative progenitors residing within the islet. Neogenesis, or that the new pancreatic islets can derive from progenitor cells present within the ducts has been reported, but the existence and identity of the progenitor cells have been debated. In this review, we focus on pancreatic ductal cells, which are islet progenitors capable of differentiating into islet {beta}-cells. Islet neogenesis, seen as budding of hormone-positive cells from the ductal epithelium, is considered to be one mechanism for normal islet growth after birth and in regeneration, and has suggested the presence of pancreatic stem cells. Numerous results support the neogenesis hypothesis, the evidence for the hypothesis in the adult comes primarily from morphological studies that have in common the production of damage to all or part of the pancreas, with consequent inflammation and repair. Although numerous studies support a ductal origin for new islets after birth, lineage-tracing experiments are considered the 'gold standard' of proof. Lineage-tracing experiments show that pancreatic duct cells act as progenitors, giving rise to new islets after birth and after injury. The identification of differentiated pancreatic ductal

  6. Haematopoietic stem and progenitor cells from human pluripotent stem cells

    Science.gov (United States)

    Sugimura, Ryohichi; Jha, Deepak Kumar; Han, Areum; Soria-Valles, Clara; da Rocha, Edroaldo Lummertz; Lu, Yi-Fen; Goettel, Jeremy A.; Serrao, Erik; Rowe, R. Grant; Malleshaiah, Mohan; Wong, Irene; Sousa, Patricia; Zhu, Ted N.; Ditadi, Andrea; Keller, Gordon; Engelman, Alan N.; Snapper, Scott B.; Doulatov, Sergei; Daley, George Q.

    2018-01-01

    A variety of tissue lineages can be differentiated from pluripotent stem cells by mimicking embryonic development through stepwise exposure to morphogens, or by conversion of one differentiated cell type into another by enforced expression of master transcription factors. Here, to yield functional human haematopoietic stem cells, we perform morphogen-directed differentiation of human pluripotent stem cells into haemogenic endothelium followed by screening of 26 candidate haematopoietic stem-cell-specifying transcription factors for their capacity to promote multi-lineage haematopoietic engraftment in mouse hosts. We recover seven transcription factors (ERG, HOXA5, HOXA9, HOXA10, LCOR, RUNX1 and SPI1) that are sufficient to convert haemogenic endothelium into haematopoietic stem and progenitor cells that engraft myeloid, B and T cells in primary and secondary mouse recipients. Our combined approach of morphogen-driven differentiation and transcription-factor-mediated cell fate conversion produces haematopoietic stem and progenitor cells from pluripotent stem cells and holds promise for modelling haematopoietic disease in humanized mice and for therapeutic strategies in genetic blood disorders. PMID:28514439

  7. Notch3 marks clonogenic mammary luminal progenitor cells in vivo.

    Science.gov (United States)

    Lafkas, Daniel; Rodilla, Veronica; Huyghe, Mathilde; Mourao, Larissa; Kiaris, Hippokratis; Fre, Silvia

    2013-10-14

    The identity of mammary stem and progenitor cells remains poorly understood, mainly as a result of the lack of robust markers. The Notch signaling pathway has been implicated in mammary gland development as well as in tumorigenesis in this tissue. Elevated expression of the Notch3 receptor has been correlated to the highly aggressive "triple negative" human breast cancer. However, the specific cells expressing this Notch paralogue in the mammary gland remain unknown. Using a conditionally inducible Notch3-CreERT2(SAT) transgenic mouse, we genetically marked Notch3-expressing cells throughout mammary gland development and followed their lineage in vivo. We demonstrate that Notch3 is expressed in a highly clonogenic and transiently quiescent luminal progenitor population that gives rise to a ductal lineage. These cells are capable of surviving multiple successive pregnancies, suggesting a capacity to self-renew. Our results also uncover a role for the Notch3 receptor in restricting the proliferation and consequent clonal expansion of these cells.

  8. Development and molecular composition of the hepatic progenitor cell niche.

    Science.gov (United States)

    Vestentoft, Peter Siig

    2013-05-01

    End-stage liver diseases represent major health problems that are currently treated by liver transplantation. However, given the world-wide shortage of donor livers novel strategies are needed for therapeutic treatment. Adult stem cells have the ability to self-renew and differentiate into the more specialized cell types of a given organ and are found in tissues throughout the body. These cells, whose progeny are termed progenitor cells in human liver and oval cells in rodents, have the potential to treat patients through the generation of hepatic parenchymal cells, even from the patient's own tissue. Little is known regarding the nature of the hepatic progenitor cells. Though they are suggested to reside in the most distal part of the biliary tree, the canal of Hering, the lack of unique surface markers for these cells has hindered their isolation and characterization. Upon activation, they proliferate and form ductular structures, termed "ductular reactions", which radiate into the hepatic parenchyma. The ductular reactions contain activated progenitor cells that not only acquire a phenotype resembling that observed in developing liver but also display markers of differentiation shared with the cholangiocytic or hepatocytic lineages, the two parenchymal hepatic cell types. Interactions between the putative progenitor cells, the surrounding support cells and the extracellular matrix scaffold, all constituting the progenitor cell niche, are likely to be important for regulating progenitor cell activity and differentiation. Therefore, identifying novel progenitor cell markers and deciphering their microenvironment could facilitate clinical use. The aims of the present PhD thesis were to expand knowledge of the hepatic progenitor cell niche and characterize it both during development and in disease. Several animal models of hepatic injury are known to induce activation of the progenitor cells. In order to identify possible progenitor cell markers and niche components

  9. Human mammary progenitor cell fate decisions are products of interactions with combinatorial microenvironments

    Energy Technology Data Exchange (ETDEWEB)

    LaBarge, Mark A; Nelson, Celeste M; Villadsen, Rene; Fridriksdottir, Agla; Ruth, Jason R; Stampfer, Martha R; Petersen, Ole W; Bissell, Mina J

    2008-09-19

    In adult tissues, multi-potent progenitor cells are some of the most primitive members of the developmental hierarchies that maintain homeostasis. That progenitors and their more mature progeny share identical genomes, suggests that fate decisions are directed by interactions with extrinsic soluble factors, ECM, and other cells, as well as physical properties of the ECM. To understand regulation of fate decisions, therefore, would require a means of understanding carefully choreographed combinatorial interactions. Here we used microenvironment protein microarrays to functionally identify combinations of cell-extrinsic mammary gland proteins and ECM molecules that imposed specific cell fates on bipotent human mammary progenitor cells. Micropatterned cell culture surfaces were fabricated to distinguish between the instructive effects of cell-cell versus cell-ECM interactions, as well as constellations of signaling molecules; and these were used in conjunction with physiologically relevant 3 dimensional human breast cultures. Both immortalized and primary human breast progenitors were analyzed. We report on the functional ability of those proteins of the mammary gland that maintain quiescence, maintain the progenitor state, and guide progenitor differentiation towards myoepithelial and luminal lineages.

  10. Acute leukemias of ambiguous lineage.

    Science.gov (United States)

    Béné, Marie C; Porwit, Anna

    2012-02-01

    The 2008 edition of the WHO Classification of Tumors of Haematopoietic and Lymphoid Tissues recognizes a special category called "leukemias of ambiguous lineage." The vast majority of these rare leukemias are classified as mixed phenotype acute leukemia (MPAL), although acute undifferentiated leukemias and natural killer lymphoblastic leukemias are also included. The major immunophenotypic markers used by the WHO 2008 to determine the lineage for these proliferations are myeloperoxidase, CD19, and cytoplasmic CD3. However, extensive immunophenotyping is necessary to confirm that the cells indeed belong to 2 different lineages or coexpress differentiation antigens of more than 1 lineage. Specific subsets of MPAL are defined by chromosomal anomalies such as the t(9;22) Philadelphia chromosome BCR-ABL1 or involvement of the MLL gene on chromosome 11q23. Other MPAL are divided into B/myeloid NOS, T/myeloid NOS, B/T NOS, and B/T/myeloid NOS. MPAL are usually of dire prognosis, respond variably to chemotherapy of acute lymphoblastic or acute myeloblastic type, and benefit most from rapid allogeneic hematopoietic stem cell transplantation.

  11. The stream of precursors that colonizes the thymus proceeds selectively through the early T lineage precursor stage of T cell development

    Science.gov (United States)

    Benz, Claudia; Martins, Vera C.; Radtke, Freddy; Bleul, Conrad C.

    2008-01-01

    T cell development in the thymus depends on continuous colonization by hematopoietic precursors. Several distinct T cell precursors have been identified, but whether one or several independent precursor cell types maintain thymopoiesis is unclear. We have used thymus transplantation and an inducible lineage-tracing system to identify the intrathymic precursor cells among previously described thymus-homing progenitors that give rise to the T cell lineage in the thymus. Extrathymic precursors were not investigated in these studies. Both approaches show that the stream of T cell lineage precursor cells, when entering the thymus, selectively passes through the early T lineage precursor (ETP) stage. Immigrating precursor cells do not exhibit characteristics of double-negative (DN) 1c, DN1d, or DN1e stages, or of populations containing the common lymphoid precursor 2 (CLP-2) or the thymic equivalent of circulating T cell progenitors (CTPs). It remains possible that an unknown hematopoietic precursor cell or previously described extrathymic precursors with a CLP, CLP-2, or CTP phenotype feed into T cell development by circumventing known intrathymic T cell lineage progenitor cells. However, it is clear that of the known intrathymic precursors, only the ETP population contributes significant numbers of T lineage precursors to T cell development. PMID:18458114

  12. The Fold of Commitment

    DEFF Research Database (Denmark)

    Raastrup Kristensen, Anders; Pedersen, Michael

    2016-01-01

    This paper serves two purposes. First, a rereading of Douglas McGregor’s An uneasy look at performance appraisal serves to show how McGregor’s conceptualization of commitment as a question of integrating personal goals with organizational purpose has helped shape founding the modern understanding...

  13. Genetic Modification of Human Pancreatic Progenitor Cells Through Modified mRNA.

    Science.gov (United States)

    Lu, Song; Chow, Christie C; Zhou, Junwei; Leung, Po Sing; Tsui, Stephen K; Lui, Kathy O

    2016-01-01

    In this chapter, we describe a highly efficient genetic modification strategy for human pancreatic progenitor cells using modified mRNA-encoding GFP and Neurogenin-3. The properties of modified mRNA offer an invaluable platform to drive protein expression, which has broad applicability in pathway regulation, directed differentiation, and lineage specification. This approach can also be used to regulate expression of other pivotal transcription factors during pancreas development and might have potential therapeutic values in regenerative medicine.

  14. Employee organizational commitment

    Directory of Open Access Journals (Sweden)

    Radosavljević Života

    2017-01-01

    Full Text Available This paper shows the results of research on organizational commitment as a type of attitudes that show the identification level of employees with their organizations and their willingness to leave them. The research has been conducted with intention to determine the level of organizational commitment on the territory of Novi Sad, as well as to question whether there is a difference between certain categories of examinees for each commitment base. The research comprised 237 examinees employed in organizations on the territory of Novi Sad. Status of independent variables have gained: gender, years of working experience, educational level, working experience in one or more organizations and estimation of level of personal potentials utility. The questionnaire used is taken from the Greenberg and Baron's 'Behaviour in Organizations', p. 170, done according to set of questions by Meyer and Allen, in 1991. The data have been worked on by calculating arithmetic mean, and by application of Pearson Chi-square test. The results have shown that there is a below average level of organizational (AS=2.88, with the most intensive continual (AS=3.23, and the least intensive normative organizational dedication (AS=2.41. The gender of examinees does not represent relevant source of differences in the levels of each type of three mentioned commitment. Years of working experience and level of educational attainment represent a significant source of differences for continual (YWE: Pearson Chi-square = 30,38; df = 8; p = .000 (LEA: Pearson Chi-square = 7,381; df = 2; p = .05 and normative (YWE: Pearson Chi- square = 20,67; df = 8; p = .000 (LEA: Pearson Chi-square = 10,79; df = 2; p = .00 base of commitment. Work in one or more organizations has shown as a significant source of differences in the level of continual commitment (Pearson Chi-square = 7, 59; df = 2; p = .05. The level of affective commitment is statistically significantly related only to the estimation

  15. Radiation effect on oligodendroglial lineage cells of brain

    International Nuclear Information System (INIS)

    Yu Dahai; Tianye

    2009-01-01

    Radiotherapy is a important treatment method for primary and metastatic cancers in the brain. How-ever, a high dose of radiation always leads to the brain injury. A representative pathological manifest of the radiation-induced brain impairment is demyelination. Therefore oligodendrocytes, the myelin-forming cells in the central nervous system, have been focused more attention recently. Oligodendrocytes originate from the migratory, mitotic progenitors and mature progressively into postmitotic myelinating cells. Recent years, a series of studies have been initiated to address the role of oligodendrocyte lineage cells in radiation-induced neurotoxic processes. This article pays attention to these studies, aiming to explore mechanisms of the radiation-induced brain impairment. (authors)

  16. From controlled to committed.

    Science.gov (United States)

    Hess, J C

    1996-02-01

    Most of us agree that people are our most important resource. Yet we spend a minimal amount of time learning more about human behavior, communication, and how our attitudes and behavior impact employee performance. Instead we rely on traditional methods of negative reinforcement in an attempt to control our areas of responsibility. While these methods can render some short-term success, managers and organizations that succeed during these times of change and fierce competition will be those that take the time to understand and capture the power of a committed workforce. The committed workforce is energized, not simply compliant, as a result of having basic human needs for achievement satisfied, belonging to a group, and receiving recognition for its contributions. Committed workers typically describe the manager as one who has the ability to give them a great degree of control over their area of influence. We all know that we don't change our leadership style like we change clothes. Old habits die hard. it takes a personal commitment and lots of practice to rid outselves of habits and behavior that no longer serve our departments and facilities. This commitment, however, is crucial to survival. As managers, we must cope with increasing ambiguity and uncertainty in the workplace. To survive these challenges, we must improve our interpersonal skills and ability to successfully bring out the best in others. I believe that success will continue for managers who not only increase their knowledge and technical ability, but who also inspire their workers to move forward with a collective sense of enthusiasm and purpose.

  17. The isolation and in vitro expansion of hepatic Sca-1 progenitor cells

    International Nuclear Information System (INIS)

    Clayton, Elizabeth; Forbes, Stuart J.

    2009-01-01

    The intra-hepatic population of liver progenitor cells expands during liver injury when hepatocyte proliferation is inhibited. These cells can be purified by density gradient centrifugation and cultured. Separated by size only this population contains small cells of hematopoietic, epithelial and endothelial lineages and is thought to contain liver stem cells. The identity of liver stem cells remains unknown although there is some evidence that tissue Sca1 + CD45 - cells display progenitor cell characteristics. We identified both intra-hepatic and gall bladder Sca1 + cells following liver injury and expanded ex vivo Sca1 cells as part of heterogenous cell culture or as a purified population. We found significant difference between the proliferation of Sca-1 cells when plated on laminin or collagen I while proliferation of heterogenous population was not affected by the extracellular matrix indicating the necessity for culture of Sca1 + cells with laminin matrix or laminin producing cells in long term liver progenitor cell cultures.

  18. Neurogenesis in an early protostome relative: progenitor cells in the ventral nerve center of chaetognath hatchlings are arranged in a highly organized geometrical pattern.

    Science.gov (United States)

    Perez, Yvan; Rieger, Verena; Martin, Elise; Müller, Carsten H G; Harzsch, Steffen

    2013-05-01

    Emerging evidence suggests that Chaetognatha represent an evolutionary lineage that is the sister group to all other Protostomia thus promoting these animals as a pivotal model for our understanding of bilaterian evolutionary history. We have analyzed the proliferation of neuronal progenitor cells in the developing ventral nerve center (VNC) of Spadella cephaloptera hatchlings. To that end, for the first time in Chaetognatha, we performed in vivo incorporation experiments with the S-phase specific mitosis marker bromodeoxyuridine (BrdU). Our experiments provide evidence for a high level of mitotic activity in the VNC for ca. 3 days after hatching. Neurogenesis is carried by presumptive neuronal progenitor cells that cycle rapidly and most likely divide asymmetrically. These progenitors are arranged in a distinct grid-like geometrical pattern including about 35 transverse rows. Considering Chaetognaths to be an early offshoot of the protostome lineage we conclude that the presence of neuronal progenitor cells with asymmetric division seems to be a feature that is rooted deeply in the Metazoa. In the light of previous evidence indicating the presence of serially iterated peptidergic neurons with individual identities in the chaetognath VNC, we discuss if these neuronal progenitor cells give rise to distinct lineages. Furthermore, we evaluate the serially iterated arrangement of the progenitor cells in the light of evolution of segmentation. Copyright © 2013 Wiley Periodicals, Inc.

  19. A novel serum-free monolayer culture for orderly hematopoietic differentiation of human pluripotent cells via mesodermal progenitors.

    Directory of Open Access Journals (Sweden)

    Akira Niwa

    Full Text Available Elucidating the in vitro differentiation of human embryonic stem (ES and induced pluripotent stem (iPS cells is important for understanding both normal and pathological hematopoietic development in vivo. For this purpose, a robust and simple hematopoietic differentiation system that can faithfully trace in vivo hematopoiesis is necessary. In this study, we established a novel serum-free monolayer culture that can trace the in vivo hematopoietic pathway from ES/iPS cells to functional definitive blood cells via mesodermal progenitors. Stepwise tuning of exogenous cytokine cocktails induced the hematopoietic mesodermal progenitors via primitive streak cells. These progenitors were then differentiated into various cell lineages depending on the hematopoietic cytokines present. Moreover, single cell deposition assay revealed that common bipotential hemoangiogenic progenitors were induced in our culture. Our system provides a new, robust, and simple method for investigating the mechanisms of mesodermal and hematopoietic differentiation.

  20. Lgr5+ve Stem/Progenitor Cells Contribute to Nephron Formation during Kidney Development

    Directory of Open Access Journals (Sweden)

    Nick Barker

    2012-09-01

    Full Text Available Multipotent stem cells and their lineage-restricted progeny drive nephron formation within the developing kidney. Here, we document expression of the adult stem cell marker Lgr5 in the developing kidney and assess the stem/progenitor identity of Lgr5+ve cells via in vivo lineage tracing. The appearance and localization of Lgr5+ve cells coincided with that of the S-shaped body around embryonic day 14. Lgr5 expression remained restricted to cell clusters within developing nephrons in the cortex until postnatal day 7, when expression was permanently silenced. In vivo lineage tracing identified Lgr5 as a marker of a stem/progenitor population within nascent nephrons dedicated to generating the thick ascending limb of Henle’s loop and distal convoluted tubule. The Lgr5 surface marker and experimental models described here will be invaluable for deciphering the contribution of early nephron stem cells to developmental defects and for isolating human nephron progenitors as a prerequisite to evaluating their therapeutic potential.

  1. Meis1 regulates Foxn4 expression during retinal progenitor cell differentiation

    Directory of Open Access Journals (Sweden)

    Mohammed M. Islam

    2013-09-01

    The transcription factor forkhead box N4 (Foxn4 is a key regulator in a variety of biological processes during development. In particular, Foxn4 plays an essential role in the genesis of horizontal and amacrine neurons from neural progenitors in the vertebrate retina. Although the functions of Foxn4 have been well established, the transcriptional regulation of Foxn4 expression during progenitor cell differentiation remains unclear. Here, we report that an evolutionarily conserved 129 bp noncoding DNA fragment (Foxn4CR4.2 or CR4.2, located ∼26 kb upstream of Foxn4 transcription start site, functions as a cis-element for Foxn4 regulation. CR4.2 directs gene expression in Foxn4-positive cells, primarily in progenitors, differentiating horizontal and amacrine cells. We further determined that the gene regulatory activity of CR4.2 is modulated by Meis1 binding motif, which is bound and activated by Meis1 transcription factor. Deletion of the Meis1 binding motif or knockdown of Meis1 expression abolishes the gene regulatory activity of CR4.2. In addition, knockdown of Meis1 expression diminishes the endogenous Foxn4 expression and affects cell lineage development. Together, we demonstrate that CR4.2 and its interacting Meis1 transcription factor play important roles in regulating Foxn4 expression during early retinogenesis. These findings provide new insights into molecular mechanisms that govern gene regulation in retinal progenitors and specific cell lineage development.

  2. Msx2 alters the timing of retinal ganglion cells fate commitment and differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Shao-Yun, E-mail: jiangshaoyun@yahoo.com [School of Dentistry, Tianjin Medical University, 12 Qi Xiang Tai Street, Tianjin 300070 (China); Wang, Jian-Tao, E-mail: wangjiantao65@hotmail.com [Eye Center, Tianjin Medical University, 64 Tongan Road, Tianjin 300070 (China); Dohney Eye Institute, Keck School of Medicine, University of Southern California, 1355 San Pablo Street, DOH 314, Los Angeles, CA 90033 (United States)

    2010-05-14

    Timing of cell fate commitment determines distinct retinal cell types, which is believed to be controlled by a tightly coordinated regulatory program of proliferation, cell cycle exit and differentiation. Although homeobox protein Msx2 could induce apoptosis of optic vesicle, it is unclear whether Msx2 regulates differentiation and cell fate commitment of retinal progenitor cells (RPCs) to retinal ganglion cells (RGCs). In this study, we show that overexpression of Msx2 transiently suppressed the expression of Cyclin D1 and blocked cell proliferation. Meanwhile, overexpression of Msx2 delayed the expression of RGC-specific differentiation markers (Math5 and Brn3b), which showed that Msx2 could affect the timing of RGCs fate commitment and differentiation by delaying the timing of cell cycle exit of retinal progenitors. These results indicate Msx2 possesses dual regulatory functions in controlling cell cycle progression of retinal RPCs and timing of RGCs differentiation.

  3. Hemopoietic progenitor cell identification in fetal and adult blood Célula progenitora hamatopoética - identificação em sangue fetal e de adulto

    Directory of Open Access Journals (Sweden)

    Aixa Müller

    2008-06-01

    Full Text Available Hemopoietic progenitor cells give rise to all cellular elements of the blood and are of importance as a potential source of cells used for correction of various pathological conditions. The main objective of this study was to identify and quantitative hemopoietic progenitor cell in antenatal fetal blood, in cord blood at the time of delivery and in adult blood, using monoclonal antibodies to surface markers and flow cytometry. CD34+ cells, most of them probably representing progenitor cells, were detected in prenatal fetal blood as early as the 17th week of gestation. The proportion of these cells showed a tendency to decrease as the pregnancy progressed. Within the population of CD34+ cells, a relatively low proportion (less than 1% were negative for the surface marker CD33 or HLA-Dr, indicating a population of primitive stem cells, i.e., progenitor cells no committed to a specific lineage. On the contrary, another group coexpressed CD33 or HLA-Dr, being more mature progenitor cells already committed to differentiate along a specific lineage. The percentage of CD34+ obtained in blood of adult patients after mobilization with chemotherapeutic agents and growth factors showed an average value of 2.7± 3.1%. The percentage of CD34+ in the apheresis products of various patients varied from 0.58 to 1.48. In some cases the cells were reinfused in the patient with good results. Our findings are in agreement with previous studies suggesting that CD34+ stem cells is a heterogeneous population, with each subset having variable degree o commitment to differentiate toward a specific cell lineage.As células progenitoras hematopoéticas são as responsáveis pela produção de todos os elementos do sangue e são as potenciais fontes de células usadas para o tratamento de várias condições patológicas. O principal objetivo deste trabalho foi identificar e quantificar as células progenitoras hematopoiéticas no sangue fetal do período pré-natal, no

  4. Evolution of two distinct phylogenetic lineages of the emerging human pathogen Mycobacterium ulcerans

    Directory of Open Access Journals (Sweden)

    Portaels Francoise

    2007-09-01

    Full Text Available Abstract Background Comparative genomics has greatly improved our understanding of the evolution of pathogenic mycobacteria such as Mycobacterium tuberculosis. Here we have used data from a genome microarray analysis to explore insertion-deletion (InDel polymorphism among a diverse strain collection of Mycobacterium ulcerans, the causative agent of the devastating skin disease, Buruli ulcer. Detailed analysis of large sequence polymorphisms in twelve regions of difference (RDs, comprising irreversible genetic markers, enabled us to refine the phylogenetic succession within M. ulcerans, to define features of a hypothetical M. ulcerans most recent common ancestor and to confirm its origin from Mycobacterium marinum. Results M. ulcerans has evolved into five InDel haplotypes that separate into two distinct lineages: (i the "classical" lineage including the most pathogenic genotypes – those that come from Africa, Australia and South East Asia; and (ii an "ancestral" M. ulcerans lineage comprising strains from Asia (China/Japan, South America and Mexico. The ancestral lineage is genetically closer to the progenitor M. marinum in both RD composition and DNA sequence identity, whereas the classical lineage has undergone major genomic rearrangements. Conclusion Results of the InDel analysis are in complete accord with recent multi-locus sequence analysis and indicate that M. ulcerans has passed through at least two major evolutionary bottlenecks since divergence from M. marinum. The classical lineage shows more pronounced reductive evolution than the ancestral lineage, suggesting that there may be differences in the ecology between the two lineages. These findings improve the understanding of the adaptive evolution and virulence of M. ulcerans and pathogenic mycobacteria in general and will facilitate the development of new tools for improved diagnostics and molecular epidemiology.

  5. Sustainability Marketing Commitment

    DEFF Research Database (Denmark)

    Tollin, Karin; Bech Christensen, Lars

    2017-01-01

    sustainability in marketing, processes associated with sustainability marketing commitment, drivers of sustainability marketing at the functional level of marketing, and its organizational context. Using survey data from 269 managers in marketing, covering a broad range of industries in Sweden and Denmark, we...... took a structural modelling approach to examine construct relationships, mediation, and moderation effects. Overall, the findings show that marketing capabilities associated with the innovation of new products, services, and business models constitute a strong driver to leverage sustainability......Corporate sustainability is an important strategy and value orientation for marketing, but scarce research addresses the organizational drivers and barriers to including it in companies’ marketing strategies and processes. The purpose of this study is to determine levels of commitment to corporate...

  6. In vitro and in vivo assessment of direct effects of simulated solar and galactic cosmic radiation on human hematopoietic stem/progenitor cells.

    Science.gov (United States)

    Rodman, C; Almeida-Porada, G; George, S K; Moon, J; Soker, S; Pardee, T; Beaty, M; Guida, P; Sajuthi, S P; Langefeld, C D; Walker, S J; Wilson, P F; Porada, C D

    2017-06-01

    Future deep space missions to Mars and near-Earth asteroids will expose astronauts to chronic solar energetic particles (SEP) and galactic cosmic ray (GCR) radiation, and likely one or more solar particle events (SPEs). Given the inherent radiosensitivity of hematopoietic cells and short latency period of leukemias, space radiation-induced hematopoietic damage poses a particular threat to astronauts on extended missions. We show that exposing human hematopoietic stem/progenitor cells (HSC) to extended mission-relevant doses of accelerated high-energy protons and iron ions leads to the following: (1) introduces mutations that are frequently located within genes involved in hematopoiesis and are distinct from those induced by γ-radiation; (2) markedly reduces in vitro colony formation; (3) markedly alters engraftment and lineage commitment in vivo; and (4) leads to the development, in vivo, of what appears to be T-ALL. Sequential exposure to protons and iron ions (as typically occurs in deep space) proved far more deleterious to HSC genome integrity and function than either particle species alone. Our results represent a critical step for more accurately estimating risks to the human hematopoietic system from space radiation, identifying and better defining molecular mechanisms by which space radiation impairs hematopoiesis and induces leukemogenesis, as well as for developing appropriately targeted countermeasures.

  7. The transcriptional corepressor MTGR1 regulates intestinal secretory lineage allocation.

    Science.gov (United States)

    Parang, Bobak; Rosenblatt, Daniel; Williams, Amanda D; Washington, Mary K; Revetta, Frank; Short, Sarah P; Reddy, Vishruth K; Hunt, Aubrey; Shroyer, Noah F; Engel, Michael E; Hiebert, Scott W; Williams, Christopher S

    2015-03-01

    Notch signaling largely determines intestinal epithelial cell fate. High Notch activity drives progenitors toward absorptive enterocytes by repressing secretory differentiation programs, whereas low Notch permits secretory cell assignment. Myeloid translocation gene-related 1 (MTGR1) is a transcriptional corepressor in the myeloid translocation gene/Eight-Twenty-One family. Given that Mtgr1(-/-) mice have a dramatic reduction of intestinal epithelial secretory cells, we hypothesized that MTGR1 is a key repressor of Notch signaling. In support of this, transcriptome analysis of laser capture microdissected Mtgr1(-/-) intestinal crypts revealed Notch activation, and secretory markers Mucin2, Chromogranin A, and Growth factor-independent 1 (Gfi1) were down-regulated in Mtgr1(-/-) whole intestines and Mtgr1(-/-) enteroids. We demonstrate that MTGR1 is in a complex with Suppressor of Hairless Homolog, a key Notch effector, and represses Notch-induced Hairy/Enhancer of Split 1 activity. Moreover, pharmacologic Notch inhibition using a γ-secretase inhibitor (GSI) rescued the hyperproliferative baseline phenotype in the Mtgr1(-/-) intestine and increased production of goblet and enteroendocrine lineages in Mtgr1(-/-) mice. GSI increased Paneth cell production in wild-type mice but failed to do so in Mtgr1(-/-) mice. We determined that MTGR1 can interact with GFI1, a transcriptional corepressor required for Paneth cell differentiation, and repress GFI1 targets. Overall, the data suggest that MTGR1, a transcriptional corepressor well characterized in hematopoiesis, plays a critical role in intestinal lineage allocation. © FASEB.

  8. Lineage tracing of lamellocytes demonstrates Drosophila macrophage plasticity.

    Directory of Open Access Journals (Sweden)

    Martin Stofanko

    2010-11-01

    Full Text Available Leukocyte-like cells called hemocytes have key functions in Drosophila innate immunity. Three hemocyte types occur: plasmatocytes, crystal cells, and lamellocytes. In the absence of qimmune challenge, plasmatocytes are the predominant hemocyte type detected, while crystal cells and lamellocytes are rare. However, upon infestation by parasitic wasps, or in melanotic mutant strains, large numbers of lamellocytes differentiate and encapsulate material recognized as "non-self". Current models speculate that lamellocytes, plasmatocytes and crystal cells are distinct lineages that arise from a common prohemocyte progenitor. We show here that over-expression of the CoREST-interacting transcription factor Chn in plasmatocytes induces lamellocyte differentiation, both in circulation and in lymph glands. Lamellocyte increases are accompanied by the extinction of plasmatocyte markers suggesting that plasmatocytes are transformed into lamellocytes. Consistent with this, timed induction of Chn over-expression induces rapid lamellocyte differentiation within 18 hours. We detect double-positive intermediates between plasmatocytes and lamellocytes, and show that isolated plasmatocytes can be triggered to differentiate into lamellocytes in vitro, either in response to Chn over-expression, or following activation of the JAK/STAT pathway. Finally, we have marked plasmatocytes and show by lineage tracing that these differentiate into lamellocytes in response to the Drosophila parasite model Leptopilina boulardi. Taken together, our data suggest that lamellocytes arise from plasmatocytes and that plasmatocytes may be inherently plastic, possessing the ability to differentiate further into lamellocytes upon appropriate challenge.

  9. Possible promotion of neuronal differentiation in fetal rat brain neural progenitor cells after sustained exposure to static magnetism.

    Science.gov (United States)

    Nakamichi, Noritaka; Ishioka, Yukichi; Hirai, Takao; Ozawa, Shusuke; Tachibana, Masaki; Nakamura, Nobuhiro; Takarada, Takeshi; Yoneda, Yukio

    2009-08-15

    We have previously shown significant potentiation of Ca(2+) influx mediated by N-methyl-D-aspartate receptors, along with decreased microtubules-associated protein-2 (MAP2) expression, in hippocampal neurons cultured under static magnetism without cell death. In this study, we investigated the effects of static magnetism on the functionality of neural progenitor cells endowed to proliferate for self-replication and differentiate into neuronal, astroglial, and oligodendroglial lineages. Neural progenitor cells were isolated from embryonic rat neocortex and hippocampus, followed by culture under static magnetism at 100 mT and subsequent determination of the number of cells immunoreactive for a marker protein of particular progeny lineages. Static magnetism not only significantly decreased proliferation of neural progenitor cells without affecting cell viability, but also promoted differentiation into cells immunoreactive for MAP2 with a concomitant decrease in that for an astroglial marker, irrespective of the presence of differentiation inducers. In neural progenitors cultured under static magnetism, a significant increase was seen in mRNA expression of several activator-type proneural genes, such as Mash1, Math1, and Math3, together with decreased mRNA expression of the repressor type Hes5. These results suggest that sustained static magnetism could suppress proliferation for self-renewal and facilitate differentiation into neurons through promoted expression of activator-type proneural genes by progenitor cells in fetal rat brain.

  10. Patient-specific cardiovascular progenitor cells derived from integration-free induced pluripotent stem cells for vascular tissue regeneration.

    Science.gov (United States)

    Hu, Jiang; Wang, Yongyu; Jiao, Jiao; Liu, Zhongning; Zhao, Chao; Zhou, Zhou; Zhang, Zhanpeng; Forde, Kaitlynn; Wang, Lunchang; Wang, Jiangang; Baylink, David J; Zhang, Xiao-Bing; Gao, Shaorong; Yang, Bo; Chen, Y Eugene; Ma, Peter X

    2015-12-01

    Tissue-engineered blood vessels (TEBVs) are promising in regenerating a live vascular replacement. However, the vascular cell source is limited, and it is crucial to develop a scaffold that accommodates new type of vascular progenitor cells and facilitates in vivo lineage specification of the cells into functional vascular smooth muscle cells (VSMCs) to regenerate vascular tissue. In the present study, integration-free human induced pluripotent stem cells (hiPSCs) were established from patient peripheral blood mononuclear cells through episomal vector nucleofection of reprogramming factors. The established hiPSCs were then induced into mesoderm-originated cardiovascular progenitor cells (CVPCs) with a highly efficient directed lineage specification method. The derived CVPCs were demonstrated to be able to differentiate into functional VSMCs. Subcutaneous implantation of CVPCs seeded on macroporous nanofibrous poly(l-lactide) scaffolds led to in vivo VSMC lineage specification and matrix deposition inside the scaffolds. In summary, we established integration-free patient-specific hiPSCs from peripheral blood mononuclear cells, derived CVPCs through directed lineage specification, and developed an advanced scaffold for these progenitor cells to further differentiate in vivo into VSMCs and regenerate vascular tissue in a subcutaneous implantation model. This study has established an efficient patient-specific approach towards in vivo regeneration of vascular tissue. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Disturbances in the positioning, proliferation, and apoptosis of neural progenitors contribute to subcortical band heterotopia formation

    Science.gov (United States)

    Fitzgerald, MP; Covio, M; Lee, KS

    2011-01-01

    Cortical malformations are commonly associated with intractable epilepsy and other developmental disorders. Our studies utilize the tish rat, a spontaneously occurring genetic model of subcortical band heterotopia (SBH) associated with epilepsy, to evaluate the developmental events underlying SBH formation in the neocortex. Our results demonstrate that Pax6+ and Tbr2+ progenitors are mislocalized in tish+/− and tish−/− neocortex throughout neurogenesis. In addition, mislocalized tish−/− progenitors possess a longer cell cycle than wildtype or normally-positioned tish−/− progenitors, owing to a lengthened G2+M+G1 time. This mislocalization is not associated with adherens junction breakdown or loss of radial glial polarity in the ventricular zone, as assessed by immunohistochemistry against phalloidin (to identify F-actin), aPKC-λ, and Par3. However, vimentin immunohistochemistry indicates that the radial glial scaffold is disrupted in the region of the tish−/− heterotopia. Moreover, lineage tracing experiments using in utero electroporation in tish−/− neocortex demonstrate that mislocalized progenitors do not retain contact with the ventricular surface and that ventricular/subventricular zone progenitors produce neurons that migrate into both the heterotopia and cortical plate. Taken together, these findings define a series of developmental errors contributing to SBH formation that differs fundamentally from a primary error in neuronal migration. PMID:21145942

  12. Postnatal epithelium and mesenchyme stem/progenitor cells in bioengineered amelogenesis and dentinogenesis.

    Science.gov (United States)

    Jiang, Nan; Zhou, Jian; Chen, Mo; Schiff, Michael D; Lee, Chang H; Kong, Kimi; Embree, Mildred C; Zhou, Yanheng; Mao, Jeremy J

    2014-02-01

    Rodent incisors provide a classic model for studying epithelial-mesenchymal interactions in development. However, postnatal stem/progenitor cells in rodent incisors have not been exploited for tooth regeneration. Here, we characterized postnatal rat incisor epithelium and mesenchyme stem/progenitor cells and found that they formed enamel- and dentin-like tissues in vivo. Epithelium and mesenchyme cells were harvested separately from the apical region of postnatal 4-5 day rat incisors. Epithelial and mesenchymal phenotypes were confirmed by immunocytochemistry, CFU assay and/or multi-lineage differentiation. CK14+, Sox2+ and Lgr5+ epithelium stem cells from the cervical loop enhanced amelogenin and ameloblastin expression upon BMP4 or FGF3 stimulation, signifying their differentiation towards ameloblast-like cells, whereas mesenchyme stem/progenitor cells upon BMP4, BMP7 and Wnt3a treatment robustly expressed Dspp, a hallmark of odontoblastic differentiation. We then control-released microencapsulated BMP4, BMP7 and Wnt3a in transplants of epithelium and mesenchyme stem/progenitor cells in the renal capsule of athymic mice in vivo. Enamel and dentin-like tissues were generated in two integrated layers with specific expression of amelogenin and ameloblastin in the newly formed, de novo enamel-like tissue, and DSP in dentin-like tissue. These findings suggest that postnatal epithelium and mesenchyme stem/progenitor cells can be primed towards bioengineered tooth regeneration. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. CRX is a diagnostic marker of retinal and pineal lineage tumors.

    Directory of Open Access Journals (Sweden)

    Sandro Santagata

    2009-11-01

    Full Text Available CRX is a homeobox transcription factor whose expression and function is critical to maintain retinal and pineal lineage cells and their progenitors. To determine the biologic and diagnostic potential of CRX in human tumors of the retina and pineal, we examined its expression in multiple settings.Using situ hybridization and immunohistochemistry we show that Crx RNA and protein expression are exquisitely lineage restricted to retinal and pineal cells during normal mouse and human development. Gene expression profiling analysis of a wide range of human cancers and cancer cell lines also supports that CRX RNA is highly lineage restricted in cancer. Immunohistochemical analysis of 22 retinoblastomas and 13 pineal parenchymal tumors demonstrated strong expression of CRX in over 95% of these tumors. Importantly, CRX was not detected in the majority of tumors considered in the differential diagnosis of pineal region tumors (n = 78. The notable exception was medulloblastoma, 40% of which exhibited CRX expression in a heterogeneous pattern readily distinguished from that seen in retino-pineal tumors.These findings describe new potential roles for CRX in human cancers and highlight the general utility of lineage restricted transcription factors in cancer biology. They also identify CRX as a sensitive and specific clinical marker and a potential lineage dependent therapeutic target in retinoblastoma and pineoblastoma.

  14. Single cell cultures of Drosophila neuroectodermal and mesectodermal central nervous system progenitors reveal different degrees of developmental autonomy.

    Science.gov (United States)

    Lüer, Karin; Technau, Gerhard M

    2009-08-03

    The Drosophila embryonic central nervous system (CNS) develops from two sets of progenitor cells, neuroblasts and ventral midline progenitors, which behave differently in many respects. Neuroblasts derive from the neurogenic region of the ectoderm and form the lateral parts of the CNS. Ventral midline precursors are formed by two rows of mesectodermal cells and build the CNS midline. There is plenty of evidence that individual identities are conferred to precursor cells by positional information in the ectoderm. It is unclear, however, how far the precursors can maintain their identities and developmental properties in the absence of normal external signals. To separate the respective contributions of autonomous properties versus extrinsic signals during their further development, we isolated individual midline precursors and neuroectodermal precursors at the pre-mitotic gastrula stage, traced their development in vitro, and analyzed the characteristics of their lineages in comparison with those described for the embryo. Although individually cultured mesectodermal cells exhibit basic characteristics of CNS midline progenitors, the clones produced by these progenitors differ from their in situ counterparts with regard to cell numbers, expression of molecular markers, and the separation of neuronal and glial fate. In contrast, clones derived from individually cultured precursors taken from specific dorsoventral zones of the neuroectoderm develop striking similarities to the lineages of neuroblasts that normally delaminate from these zones and develop in situ. This in vitro analysis allows for the first time a comparison of the developmental capacities in situ and in vitro of individual neural precursors of defined spatial and temporal origin. The data reveal that cells isolated at the pre-mitotic and pre-delamination stage express characteristics of the progenitor type appropriate to their site of origin in the embryo. However, presumptive neuroblasts, once

  15. Single cell cultures of Drosophila neuroectodermal and mesectodermal central nervous system progenitors reveal different degrees of developmental autonomy

    Directory of Open Access Journals (Sweden)

    Technau Gerhard M

    2009-08-01

    Full Text Available Abstract Background The Drosophila embryonic central nervous system (CNS develops from two sets of progenitor cells, neuroblasts and ventral midline progenitors, which behave differently in many respects. Neuroblasts derive from the neurogenic region of the ectoderm and form the lateral parts of the CNS. Ventral midline precursors are formed by two rows of mesectodermal cells and build the CNS midline. There is plenty of evidence that individual identities are conferred to precursor cells by positional information in the ectoderm. It is unclear, however, how far the precursors can maintain their identities and developmental properties in the absence of normal external signals. Results To separate the respective contributions of autonomous properties versus extrinsic signals during their further development, we isolated individual midline precursors and neuroectodermal precursors at the pre-mitotic gastrula stage, traced their development in vitro, and analyzed the characteristics of their lineages in comparison with those described for the embryo. Although individually cultured mesectodermal cells exhibit basic characteristics of CNS midline progenitors, the clones produced by these progenitors differ from their in situ counterparts with regard to cell numbers, expression of molecular markers, and the separation of neuronal and glial fate. In contrast, clones derived from individually cultured precursors taken from specific dorsoventral zones of the neuroectoderm develop striking similarities to the lineages of neuroblasts that normally delaminate from these zones and develop in situ. Conclusion This in vitro analysis allows for the first time a comparison of the developmental capacities in situ and in vitro of individual neural precursors of defined spatial and temporal origin. The data reveal that cells isolated at the pre-mitotic and pre-delamination stage express characteristics of the progenitor type appropriate to their site of origin in

  16. Organizational commitment of military physicians.

    Science.gov (United States)

    Demir, Cesim; Sahin, Bayram; Teke, Kadir; Ucar, Muharrem; Kursun, Olcay

    2009-09-01

    An individual's loyalty or bond to his or her employing organization, referred to as organizational commitment, influences various organizational outcomes such as employee motivation, job satisfaction, performance, accomplishment of organizational goals, employee turnover, and absenteeism. Therefore, as in other sectors, employee commitment is crucial also in the healthcare market. This study investigates the effects of organizational factors and personal characteristics on organizational commitment of military physicians using structural equation modeling (SEM) on a self-report, cross-sectional survey that consisted of 635 physicians working in the 2 biggest military hospitals in Turkey. The results of this study indicate that professional commitment and organizational incentives contribute positively to organizational commitment, whereas conflict with organizational goals makes a significantly negative contribution to it. These results might help develop strategies to increase employee commitment, especially in healthcare organizations, because job-related factors have been found to possess greater impact on organizational commitment than personal characteristics.

  17. Dclk1 Defines Quiescent Pancreatic Progenitors that Promote Injury-Induced Regeneration and Tumorigenesis | Office of Cancer Genomics

    Science.gov (United States)

    The existence of adult pancreatic progenitor cells has been debated. While some favor the concept of facultative progenitors involved in homeostasis and repair, neither a location nor markers for such cells have been defined. Using genetic lineage tracing, we show that Doublecortin-like kinase-1 (Dclk1) labels a rare population of long-lived, quiescent pancreatic cells. In vitro, Dclk1+ cells proliferate readily and sustain pancreatic organoid growth. In vivo, Dclk1+ cells are necessary for pancreatic regeneration following injury and chronic inflammation.

  18. Concomitant multipotent and unipotent dental pulp progenitors and their respective contribution to mineralised tissue formation

    Directory of Open Access Journals (Sweden)

    S Dimitrova-Nakov

    2012-05-01

    Full Text Available Upon in vitro induction or in vivo implantation, the stem cells of the dental pulp display hallmarks of odontoblastic, osteogenic, adipogenic or neuronal cells. However, whether these phenotypes result from genuine multipotent cells or from coexistence of distinct progenitors is still an open question. Furthermore, determining whether a single cell-derived progenitor is capable of undergoing a differentiation cascade leading to tissue repair in situ is important for the development of cell therapy strategies. Three clonal pulp precursor cell lines (A4, C5, H8, established from embryonic ED18 first molars of mouse transgenic for a recombinant plasmid adeno-SV40, were induced to differentiate towards the odonto/osteogenic, chondrogenic or adipogenic programme. Expression of phenotypic markers of each lineage was evaluated by RT-PCR, histochemistry or immunocytochemistry. The clones were implanted into mandibular incisors or calvaria of adult mice. The A4 clone was capable of being recruited towards at least 3 mesodermal lineages in vitro and of contributing to dentin-like or bone formation, in vivo, thus behaving as a multipotent cell. In contrast, the C5 and H8 clones displayed a more restricted potential. Flow cytometric analysis revealed that isolated monopotent and multipotent clones could be distinguished by a differential expression of CD90. Altogether, isolation of these clonal lines allowed demonstrating the coexistence of multipotential and restricted-lineage progenitors in the mouse pulp. These cells may further permit unravelling specificities of the different types of pulp progenitors, hence facilitating the development of cell-based therapies of the dental pulp or other cranio-facial tissues.

  19. Mouse lung contains endothelial progenitors with high capacity to form blood and lymphatic vessels

    Directory of Open Access Journals (Sweden)

    Barleon Bernhard

    2010-07-01

    Full Text Available Abstract Background Postnatal endothelial progenitor cells (EPCs have been successfully isolated from whole bone marrow, blood and the walls of conduit vessels. They can, therefore, be classified into circulating and resident progenitor cells. The differentiation capacity of resident lung endothelial progenitor cells from mouse has not been evaluated. Results In an attempt to isolate differentiated mature endothelial cells from mouse lung we found that the lung contains EPCs with a high vasculogenic capacity and capability of de novo vasculogenesis for blood and lymph vessels. Mouse lung microvascular endothelial cells (MLMVECs were isolated by selection of CD31+ cells. Whereas the majority of the CD31+ cells did not divide, some scattered cells started to proliferate giving rise to large colonies (> 3000 cells/colony. These highly dividing cells possess the capacity to integrate into various types of vessels including blood and lymph vessels unveiling the existence of local microvascular endothelial progenitor cells (LMEPCs in adult mouse lung. EPCs could be amplified > passage 30 and still expressed panendothelial markers as well as the progenitor cell antigens, but not antigens for immune cells and hematopoietic stem cells. A high percentage of these cells are also positive for Lyve1, Prox1, podoplanin and VEGFR-3 indicating that a considerabe fraction of the cells are committed to develop lymphatic endothelium. Clonogenic highly proliferating cells from limiting dilution assays were also bipotent. Combined in vitro and in vivo spheroid and matrigel assays revealed that these EPCs exhibit vasculogenic capacity by forming functional blood and lymph vessels. Conclusion The lung contains large numbers of EPCs that display commitment for both types of vessels, suggesting that lung blood and lymphatic endothelial cells are derived from a single progenitor cell.

  20. Autoantigens targeted in scleroderma patients with vascular disease are enriched in endothelial lineage cells

    Science.gov (United States)

    McMahan, Zsuzsanna H.; Cottrell, Tricia R.; Wigley, Fredrick M.; Antiochos, Brendan; Zambidis, Elias T.; Park, Tea Soon; Halushka, Marc K.; Gutierrez-Alamillo, Laura; Cimbro, Raffaello; Rosen, Antony; Casciola-Rosen, Livia

    2016-01-01

    Objective Scleroderma patients with autoantibodies to centromere proteins (CENPs) and/or interferon-inducible protein 16 (IFI16) are at increased risk of severe vascular complications. We set out to define whether these autoantigens are enriched in cells of the vasculature. Methods Successive stages of embryoid bodies (EBs) as well as vascular progenitors were used to evaluate the expression of scleroderma autoantigens IFI16 and CENP by immunoblotting. CD31 was included to mark early blood vessels. IFI16 and CD31 expression were defined in skin paraffin sections from scleroderma patients and from healthy controls. IFI16 expression was determined by flow cytometry in circulating endothelial cells (CECs) and circulating progenitor cells (CPCs). Results Expression of CENP-A, IFI16 and CD31 was enriched in EBs at days 10 and 12 of differentiation, and particularly in cultures enriched in vascular progenitors (IFI16, CD31, CENPs A and-B). This pattern was distinct from that of comparator autoantigens. Immunohistochemical staining of skin paraffin sections showed enrichment of IFI16 in CD31-positive vascular endothelial cells in biopsies from scleroderma patients and normal controls. Flow cytometry analysis revealed IFI16 expression in CPCs, but minimal expression in CECs. Conclusion Expression of scleroderma autoantigens IFI16 and CENPs, which are associated with severe vascular disease, is increased in vascular progenitors and mature endothelial cells. High level, lineage-enriched expression of autoantigens may explain the striking association between clinical phenotypes and the immune targeting of specific autoantigens. PMID:27159521

  1. Bioreactor-induced mesenchymal progenitor cell differentiation and elastic fiber assembly in engineered vascular tissues.

    Science.gov (United States)

    Lin, Shigang; Mequanint, Kibret

    2017-09-01

    In vitro maturation of engineered vascular tissues (EVT) requires the appropriate incorporation of smooth muscle cells (SMC) and extracellular matrix (ECM) components similar to native arteries. To this end, the aim of the current study was to fabricate 4mm inner diameter vascular tissues using mesenchymal progenitor cells seeded into tubular scaffolds. A dual-pump bioreactor operating either in perfusion or pulsatile perfusion mode was used to generate physiological-like stimuli to promote progenitor cell differentiation, extracellular elastin production, and tissue maturation. Our data demonstrated that pulsatile forces and perfusion of 3D tubular constructs from both the lumenal and ablumenal sides with culture media significantly improved tissue assembly, effectively inducing mesenchymal progenitor cell differentiation to SMCs with contemporaneous elastin production. With bioreactor cultivation, progenitor cells differentiated toward smooth muscle lineage characterized by the expression of smooth muscle (SM)-specific markers smooth muscle alpha actin (SM-α-actin) and smooth muscle myosin heavy chain (SM-MHC). More importantly, pulsatile perfusion bioreactor cultivation enhanced the synthesis of tropoelastin and its extracellular cross-linking into elastic fiber compared with static culture controls. Taken together, the current study demonstrated progenitor cell differentiation and vascular tissue assembly, and provides insights into elastin synthesis and assembly to fibers. Incorporation of elastin into engineered vascular tissues represents a critical design goal for both mechanical and biological functions. In the present study, we seeded porous tubular scaffolds with multipotent mesenchymal progenitor cells and cultured in dual-pump pulsatile perfusion bioreactor. Physiological-like stimuli generated by bioreactor not only induced mesenchymal progenitor cell differentiation to vascular smooth muscle lineage but also actively promoted elastin synthesis and

  2. Roles of CDX2 and EOMES in human induced trophoblast progenitor cells

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ying, E-mail: ying.chen@hc.msu.edu [Department of Obstetrics, Gynecology and Reproductive Biology, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503 (United States); Wang, Kai [Department of Obstetrics, Gynecology and Reproductive Biology, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503 (United States); Gong, Yun Guo; Khoo, Sok Kean [Genomic Microarray Core Facility, Van Andel Research Institute, Grand Rapids, MI 49503 (United States); Leach, Richard, E-mail: Richard.Leach@hc.msu.edu [Department of Obstetrics, Gynecology and Reproductive Biology, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503 (United States); Department of Obstetrics, Gynecology and Women’s Health, Spectrum Health Medical Group, Grand Rapids, MI 49503 (United States)

    2013-02-08

    Highlights: ► CDX2 and EOMES play critical roles in human induced trophoblast progenitors (iTP). ► iTP cells directly transformed from fibroblasts. ► Differentiation of iTP cells into extravillous trophoblasts and syncytiotrophoblasts. -- Abstract: Abnormal trophoblast lineage proliferation and differentiation in early pregnancy have been associated with the pathogenesis of placenta diseases of pregnancy. However, there is still a gap in understanding the molecular mechanisms of early placental development due to the limited primary trophoblast cultures and fidelity of immortalized trophoblast lines. Trophoblasts stem (TS) cells, an in vitro model of trophectoderm that can differentiate into syncytiotrophoblasts and extravillous trophoblasts, can be an attractive tool for early pregnancy research. TS cells are well established in mouse but not in humans due to insufficient knowledge of which trophoblast lineage-specific transcription factors are involved in human trophectoderm (TE) proliferation and differentiation. Here, we applied induced pluripotent stem cell technique to investigate the human trophoblast lineage-specific transcription factors. We established human induced trophoblast progenitor (iTP) cells by direct reprogramming the fibroblasts with a pool of mouse trophoblast lineage-specific transcription factors consisting of CDX2, EOMES, and ELF5. The human iTP cells exhibit epithelial morphology and can be maintained in vitro for more than 2 months. Gene expression profile of these cells was tightly clustered with human trophectoderm but not with human neuron progenitor cells, mesenchymal stem cells, or endoderm cells. These cells are capable of differentiating into cells with an invasive capacity, suggesting extravillous trophoblasts. They also form multi-nucleated cells which secrete human chorionic gonadotropin and estradiol, consistent with a syncytiotrophoblast phenotype. Our results provide the evidence that transcription factors CDX2 and

  3. Identification and characterization of Xenopus tropicalis common progenitors of Sertoli and peritubular myoid cell lineages

    Czech Academy of Sciences Publication Activity Database

    Tlapáková, T.; Nguyen, T.M.X.; Vegrichtova, M.; Šídová, Monika; Strnadova, K.; Bláhová, M.; Krylov, V.

    2016-01-01

    Roč. 5, č. 9 (2016), s. 1275-1282 ISSN 2046-6390 R&D Projects: GA AV ČR LK21305; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:86652036 Keywords : Testicular somatic cells * Xenopus tropicalis * Migration potential Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.095, year: 2016

  4. The poster as modernist progenitor

    Directory of Open Access Journals (Sweden)

    Katherine Hauser

    2015-12-01

    Full Text Available Ruth E. Iskin’s The Poster: Art, Advertising. Design, and Collecting, 1860s-1900s positions the late-nineteenth-century advertising poster as the progenitor of valued modernist practices typically attached solely to photography and film. Modernist biases separating high art from mass culture account for scholars ignoring posters, however the poster ushered in an innovative reductive graphic style as well as pioneered the notion of multiple originals.

  5. PROGENITORS OF RECOMBINING SUPERNOVA REMNANTS

    Energy Technology Data Exchange (ETDEWEB)

    Moriya, Takashi J., E-mail: takashi.moriya@ipmu.jp [Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8583 (Japan)

    2012-05-01

    Usual supernova remnants have either ionizing plasma or plasma in collisional ionization equilibrium, i.e., the ionization temperature is lower than or equal to the electron temperature. However, the existence of recombining supernova remnants, i.e., supernova remnants with ionization temperature higher than the electron temperature, has been recently confirmed. One suggested way to have recombining plasma in a supernova remnant is to have a dense circumstellar medium at the time of the supernova explosion. If the circumstellar medium is dense enough, collisional ionization equilibrium can be established in the early stage of the evolution of the supernova remnant and subsequent adiabatic cooling, which occurs after the shock wave gets out of the dense circumstellar medium, makes the electron temperature lower than the ionization temperature. We study the circumstellar medium around several supernova progenitors and show which supernova progenitors can have a circumstellar medium dense enough to establish collisional ionization equilibrium soon after the explosion. We find that the circumstellar medium around red supergiants (especially massive ones) and the circumstellar medium dense enough to make Type IIn supernovae can establish collisional ionization equilibrium soon after the explosion and can evolve to become recombining supernova remnants. Wolf-Rayet stars and white dwarfs have the possibility to be recombining supernova remnants but the fraction is expected to be very small. As the occurrence rate of the explosions of red supergiants is much higher than that of Type IIn supernovae, the major progenitors of recombining supernova remnants are likely to be red supergiants.

  6. Nitric oxide synthase 2 is required for conversion of pro-fibrogenic inflammatory CD133(+) progenitors into F4/80(+) macrophages in experimental autoimmune myocarditis.

    Science.gov (United States)

    Blyszczuk, Przemyslaw; Berthonneche, Corrine; Behnke, Silvia; Glönkler, Marcel; Moch, Holger; Pedrazzini, Thierry; Lüscher, Thomas F; Eriksson, Urs; Kania, Gabriela

    2013-02-01

    Experimental autoimmune myocarditis (EAM) model mirrors important mechanisms of inflammatory dilated cardiomyopathy (iDCM). In EAM, inflammatory CD133(+) progenitors are a major cellular source of cardiac myofibroblasts in the post-inflammatory myocardium. We hypothesized that exogenous delivery of macrophage-colony-stimulating factor (M-CSF) can stimulate macrophage lineage differentiation of inflammatory progenitors and, therefore, prevent their naturally occurring myofibroblast fate in EAM. EAM was induced in wild-type (BALB/c) and nitric oxide synthase 2-deficient (Nos2(-/-)) mice and CD133(+) progenitors were isolated from inflamed hearts. In vitro, M-CSF converted inflammatory CD133(+) progenitors into nitric oxide-producing F4/80(+) macrophages and prevented transforming growth factor-β-mediated myofibroblast differentiation. Importantly, only a subset of heart-infiltrating CD133(+) progenitors expresses macrophage-specific antigen F4/80 in EAM. These CD133(+)/F4/80(hi) cells show impaired myofibrogenic potential compared with CD133(+)/F4/80(-) cells. M-CSF treatment of wild-type mice with EAM at the peak of disease markedly increased CD133(+)/F4/80(hi) cells in the myocardium, and CD133(+) progenitors isolated from M-CSF-treated mice failed to differentiate into myofibroblasts. In contrast, M-CSF was not effective in converting CD133(+) progenitors from inflamed hearts of Nos2(-/-) mice into macrophages, and M-CSF treatment did not result in increased CD133(+)/F4/80(hi) cell population in hearts of Nos2(-/-) mice. Accordingly, M-CSF prevented post-inflammatory fibrosis and left ventricular dysfunction in wild-type but not in Nos2(-/-) mice. Active and NOS2-dependent induction of macrophage lineage differentiation abrogates the myofibrogenic potential of heart-infiltrating CD133(+) progenitors. Modulating the in vivo differentiation fate of specific progenitors might become a novel approach for the treatment of inflammatory heart diseases.

  7. Lin28 sustains early renal progenitors and induces Wilms tumor

    Science.gov (United States)

    Urbach, Achia; Yermalovich, Alena; Zhang, Jin; Spina, Catherine S.; Zhu, Hao; Perez-Atayde, Antonio R.; Shukrun, Rachel; Charlton, Jocelyn; Sebire, Neil; Mifsud, William; Dekel, Benjamin; Pritchard-Jones, Kathy; Daley, George Q.

    2014-01-01

    Wilms Tumor, the most common pediatric kidney cancer, evolves from the failure of terminal differentiation of the embryonic kidney. Here we show that overexpression of the heterochronic regulator Lin28 during kidney development in mice markedly expands nephrogenic progenitors by blocking their final wave of differentiation, ultimately resulting in a pathology highly reminiscent of Wilms tumor. Using lineage-specific promoters to target Lin28 to specific cell types, we observed Wilms tumor only when Lin28 is aberrantly expressed in multiple derivatives of the intermediate mesoderm, implicating the cell of origin as a multipotential renal progenitor. We show that withdrawal of Lin28 expression reverts tumorigenesis and markedly expands the numbers of glomerulus-like structures and that tumor formation is suppressed by enforced expression of Let-7 microRNA. Finally, we demonstrate overexpression of the LIN28B paralog in a significant percentage of human Wilms tumor. Our data thus implicate the Lin28/Let-7 pathway in kidney development and tumorigenesis. PMID:24732380

  8. Cancer Progenitor Cells: The Result of an Epigenetic Event?

    Science.gov (United States)

    Lapinska, Karolina; Faria, Gabriela; McGonagle, Sandra; Macumber, Kate Morgan; Heerboth, Sarah; Sarkar, Sibaji

    2018-01-01

    The concept of cancer stem cells was proposed in the late 1990s. Although initially the idea seemed controversial, the existence of cancer stem cells is now well established. However, the process leading to the formation of cancer stem cells is still not clear and thus requires further research. This article discusses epigenetic events that possibly produce cancer progenitor cells from predisposed cells by the influence of their environment. Every somatic cell possesses an epigenetic signature in terms of histone modifications and DNA methylation, which are obtained during lineage-specific differentiation of pluripotent stem cells, which is specific to that particular tissue. We call this signature an epigenetic switch. The epigenetic switch is not fixed. Our epigenome alters with aging. However, depending on the predisposition of the cells of a particular tissue and their microenvironment, the balance of the switch (histone modifications and the DNA methylation) may be tilted to immortality in a few cells, which generates cancer progenitor cells. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  9. Work values and organizational commitment.

    Science.gov (United States)

    Kidron, A

    1978-06-01

    Dubin, Champoux and Porter (1975) found a strong relationship between central life interests of workers and their commitment to the organization. This paper extends their findings by investigating the relationship between work values, defined as the Protestant Ethic of the worker, and commitment to the organization. A distinction is made between moral and calculative commitment, and it is shown that work values are related more to moral than calculative involvement.

  10. Robust generation and expansion of skeletal muscle progenitors and myocytes from human pluripotent stem cells.

    Science.gov (United States)

    Shelton, Michael; Kocharyan, Avetik; Liu, Jun; Skerjanc, Ilona S; Stanford, William L

    2016-05-15

    Human pluripotent stem cells provide a developmental model to study early embryonic and tissue development, tease apart human disease processes, perform drug screens to identify potential molecular effectors of in situ regeneration, and provide a source for cell and tissue based transplantation. Highly efficient differentiation protocols have been established for many cell types and tissues; however, until very recently robust differentiation into skeletal muscle cells had not been possible unless driven by transgenic expression of master regulators of myogenesis. Nevertheless, several breakthrough protocols have been published in the past two years that efficiently generate cells of the skeletal muscle lineage from pluripotent stem cells. Here, we present an updated version of our recently described 50-day protocol in detail, whereby chemically defined media are used to drive and support muscle lineage development from initial CHIR99021-induced mesoderm through to PAX7-expressing skeletal muscle progenitors and mature skeletal myocytes. Furthermore, we report an optional method to passage and expand differentiating skeletal muscle progenitors approximately 3-fold every 2weeks using Collagenase IV and continued FGF2 supplementation. Both protocols have been optimized using a variety of human pluripotent stem cell lines including patient-derived induced pluripotent stem cells. Taken together, our differentiation and expansion protocols provide sufficient quantities of skeletal muscle progenitors and myocytes that could be used for a variety of studies. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  11. Multilineage Potential and Self-Renewal Define an Epithelial Progenitor Cell Population in the Adult Thymus

    Directory of Open Access Journals (Sweden)

    Kahlia Wong

    2014-08-01

    Full Text Available Thymic epithelial cells (TECs are critical for T cell development and self-tolerance but are gradually lost with age. The existence of thymic epithelial progenitors (TEPCs in the postnatal thymus has been inferred, but their identity has remained enigmatic. Here, we assessed the entire adult TEC compartment in order to reveal progenitor capacity is retained exclusively within a subset of immature thymic epithelium displaying several hallmark features of stem/progenitor function. These adult TEPCs generate mature cortical and medullary lineages in a stepwise fashion, including Aire+ TEC, within fetal thymus reaggregate grafts. Although relatively quiescent in vivo, adult TEPCs demonstrate significant in vitro colony formation and self-renewal. Importantly, 3D-cultured TEPCs retain their capacity to differentiate into cortical and medullary TEC lineages when returned to an in vivo thymic microenvironment. No other postnatal TEC subset exhibits this combination of properties. The characterization of adult TEPC will enable progress in understanding TEC biology in aging and regeneration.

  12. Light-sheet fluorescence imaging to localize cardiac lineage and protein distribution

    Science.gov (United States)

    Ding, Yichen; Lee, Juhyun; Ma, Jianguo; Sung, Kevin; Yokota, Tomohiro; Singh, Neha; Dooraghi, Mojdeh; Abiri, Parinaz; Wang, Yibin; Kulkarni, Rajan P.; Nakano, Atsushi; Nguyen, Thao P.; Fei, Peng; Hsiai, Tzung K.

    2017-02-01

    Light-sheet fluorescence microscopy (LSFM) serves to advance developmental research and regenerative medicine. Coupled with the paralleled advances in fluorescence-friendly tissue clearing technique, our cardiac LSFM enables dual-sided illumination to rapidly uncover the architecture of murine hearts over 10 by 10 by 10 mm3 in volume; thereby allowing for localizing progenitor differentiation to the cardiomyocyte lineage and AAV9-mediated expression of exogenous transmembrane potassium channels with high contrast and resolution. Without the steps of stitching image columns, pivoting the light-sheet and sectioning the heart mechanically, we establish a holistic strategy for 3-dimentional reconstruction of the “digital murine heart” to assess aberrant cardiac structures as well as the spatial distribution of the cardiac lineages in neonates and ion-channels in adults.

  13. 24 CFR 232.510 - Commitment and commitment fee.

    Science.gov (United States)

    2010-04-01

    ... HOUSING AND URBAN DEVELOPMENT MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER AUTHORITIES MORTGAGE INSURANCE FOR NURSING HOMES, INTERMEDIATE CARE FACILITIES, BOARD AND CARE HOMES, AND... of Fire Safety Equipment Fees and Charges § 232.510 Commitment and commitment fee. (a) Issuance of...

  14. NEURAL PROGENITORS, PATTERNING AND ECOLOGY IN NEOCORTICAL ORIGINS

    Directory of Open Access Journals (Sweden)

    Francisco eAboitiz

    2013-11-01

    Full Text Available The anatomical organization of the mammalian neocortex stands out among vertebrates for its laminar and columnar arrangement, featuring vertically oriented, excitatory pyramidal neurons. The evolutionary origin of this structure is discussed here in relation to the brain organization of other amniotes, i.e. the sauropsids (reptiles and birds. Specifically, we address the developmental modifications that had to take place to generate the neocortex, and to what extent these modifications were shared by other amniote lineages or can be considered unique to mammals. In this article, we propose a hypothesis that combines the control of proliferation in neural progenitor pools with the specification of regional morphogenetic gradients, yielding different anatomical results by virtue of the differential modulation of these processes in each lineage. Thus, there is a highly conserved genetic and developmental battery that becomes modulated in different directions according to specific selective pressures. In the case of early mammals, ecological conditions like nocturnal habits and reproductive strategies are considered to have played a key role in the selection of the particular brain patterning mechanisms that led to the origin of the neocortex.

  15. Human Urine-Derived Renal Progenitors for Personalized Modeling of Genetic Kidney Disorders.

    Science.gov (United States)

    Lazzeri, Elena; Ronconi, Elisa; Angelotti, Maria Lucia; Peired, Anna; Mazzinghi, Benedetta; Becherucci, Francesca; Conti, Sara; Sansavini, Giulia; Sisti, Alessandro; Ravaglia, Fiammetta; Lombardi, Duccio; Provenzano, Aldesia; Manonelles, Anna; Cruzado, Josep M; Giglio, Sabrina; Roperto, Rosa Maria; Materassi, Marco; Lasagni, Laura; Romagnani, Paola

    2015-08-01

    The critical role of genetic and epigenetic factors in the pathogenesis of kidney disorders is gradually becoming clear, and the need for disease models that recapitulate human kidney disorders in a personalized manner is paramount. In this study, we describe a method to select and amplify renal progenitor cultures from the urine of patients with kidney disorders. Urine-derived human renal progenitors exhibited phenotype and functional properties identical to those purified from kidney tissue, including the capacity to differentiate into tubular cells and podocytes, as demonstrated by confocal microscopy, Western blot analysis of podocyte-specific proteins, and scanning electron microscopy. Lineage tracing studies performed with conditional transgenic mice, in which podocytes are irreversibly tagged upon tamoxifen treatment (NPHS2.iCreER;mT/mG), that were subjected to doxorubicin nephropathy demonstrated that renal progenitors are the only urinary cell population that can be amplified in long-term culture. To validate the use of these cells for personalized modeling of kidney disorders, renal progenitors were obtained from (1) the urine of children with nephrotic syndrome and carrying potentially pathogenic mutations in genes encoding for podocyte proteins and (2) the urine of children without genetic alterations, as validated by next-generation sequencing. Renal progenitors obtained from patients carrying pathogenic mutations generated podocytes that exhibited an abnormal cytoskeleton structure and functional abnormalities compared with those obtained from patients with proteinuria but without genetic mutations. The results of this study demonstrate that urine-derived patient-specific renal progenitor cultures may be an innovative research tool for modeling of genetic kidney disorders. Copyright © 2015 by the American Society of Nephrology.

  16. Contexts as Shared Commitments

    Directory of Open Access Journals (Sweden)

    Manuel eGarcía-Carpintero

    2015-12-01

    Full Text Available Contemporary semantics assumes two different notions of context: one coming from Kaplan (1989, on which contexts are sets of predetermined parameters, and another originated in Stalnaker (1978, on which contexts are sets of propositions that are common ground. The latter is deservedly more popular, given its flexibility to account for context-dependent aspects of language beyond manifest indexicals, such as epistemic modals, predicates of taste, and so on and so forth; in fact, properly dealing with demonstratives (perhaps ultimately all indexicals requires that further flexibility. Even if we acknowledge Lewis (1980 point that, in a sense, Kaplanian contexts already include common ground contexts, it is better to be clear and explicit about what contexts constitutively are. Now, Stalnaker (1978, 2002, 2014 defines context-as-common-ground as a set of propositions, but recent work shows that this is not an accurate conception. The paper explains why, and provides an alternative. The main reason is that several phenomena (presuppositional treatments of pejoratives and predicates of taste, forces other than assertion require that the common ground includes non-doxastic attitudes such as appraisals, emotions, etc. Hence the common ground should not be taken to include merely contents (propositions, but those together with attitudes concerning them: shared commitments, as I will defend.

  17. Engineered Murine HSCs Reconstitute Multi-lineage Hematopoiesis and Adaptive Immunity

    Directory of Open Access Journals (Sweden)

    Yi-Fen Lu

    2016-12-01

    Full Text Available Hematopoietic stem cell (HSC transplantation is curative for malignant and genetic blood disorders, but is limited by donor availability and immune-mismatch. Deriving HSCs from patient-matched embryonic/induced-pluripotent stem cells (ESCs/iPSCs could address these limitations. Prior efforts in murine models exploited ectopic HoxB4 expression to drive self-renewal and enable multi-lineage reconstitution, yet fell short in delivering robust lymphoid engraftment. Here, by titrating exposure of HoxB4-ESC-HSC to Notch ligands, we report derivation of engineered HSCs that self-renew, repopulate multi-lineage hematopoiesis in primary and secondary engrafted mice, and endow adaptive immunity in immune-deficient recipients. Single-cell analysis shows that following engraftment in the bone marrow niche, these engineered HSCs further specify to a hybrid cell type, in which distinct gene regulatory networks of hematopoietic stem/progenitors and differentiated hematopoietic lineages are co-expressed. Our work demonstrates engineering of fully functional HSCs via modulation of genetic programs that govern self-renewal and lineage priming.

  18. Colon stem cell and crypt dynamics exposed by cell lineage reconstruction.

    Directory of Open Access Journals (Sweden)

    Yitzhak Reizel

    2011-07-01

    Full Text Available Stem cell dynamics in vivo are often being studied by lineage tracing methods. Our laboratory has previously developed a retrospective method for reconstructing cell lineage trees from somatic mutations accumulated in microsatellites. This method was applied here to explore different aspects of stem cell dynamics in the mouse colon without the use of stem cell markers. We first demonstrated the reliability of our method for the study of stem cells by confirming previously established facts, and then we addressed open questions. Our findings confirmed that colon crypts are monoclonal and that, throughout adulthood, the process of monoclonal conversion plays a major role in the maintenance of crypts. The absence of immortal strand mechanism in crypts stem cells was validated by the age-dependent accumulation of microsatellite mutations. In addition, we confirmed the positive correlation between physical and lineage proximity of crypts, by showing that the colon is separated into small domains that share a common ancestor. We gained new data demonstrating that colon epithelium is clustered separately from hematopoietic and other cell types, indicating that the colon is constituted of few progenitors and ruling out significant renewal of colonic epithelium from hematopoietic cells during adulthood. Overall, our study demonstrates the reliability of cell lineage reconstruction for the study of stem cell dynamics, and it further addresses open questions in colon stem cells. In addition, this method can be applied to study stem cell dynamics in other systems.

  19. Ezh2 represses the basal cell lineage during lung endoderm development.

    Science.gov (United States)

    Snitow, Melinda E; Li, Shanru; Morley, Michael P; Rathi, Komal; Lu, Min Min; Kadzik, Rachel S; Stewart, Kathleen M; Morrisey, Edward E

    2015-01-01

    The development of the lung epithelium is regulated in a stepwise fashion to generate numerous differentiated and stem cell lineages in the adult lung. How these different lineages are generated in a spatially and temporally restricted fashion remains poorly understood, although epigenetic regulation probably plays an important role. We show that the Polycomb repressive complex 2 component Ezh2 is highly expressed in early lung development but is gradually downregulated by late gestation. Deletion of Ezh2 in early lung endoderm progenitors leads to the ectopic and premature appearance of Trp63+ basal cells that extend the entire length of the airway. Loss of Ezh2 also leads to reduced secretory cell differentiation. In their place, morphologically similar cells develop that express a subset of basal cell genes, including keratin 5, but no longer express high levels of either Trp63 or of standard secretory cell markers. This suggests that Ezh2 regulates the phenotypic switch between basal cells and secretory cells. Together, these findings show that Ezh2 restricts the basal cell lineage during normal lung endoderm development to allow the proper patterning of epithelial lineages during lung formation. © 2015. Published by The Company of Biologists Ltd.

  20. Organizational Climate and Teacher Commitment

    Science.gov (United States)

    Douglas, Stephen Michael

    2010-01-01

    This study examined the relationship of school climate and teacher commitment in elementary schools in Alabama. A total of 67 elementary schools were surveyed and 1353 teachers voluntarily participated in the study. The instruments used in this study were the Organizational Climate Index (OCI) and the Organizational Commitment Questionnaire (OCQ).…

  1. Statistical secrecy and multibit commitments

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Pedersen, Torben P.; Pfitzmann, Birgit

    1998-01-01

    nothing about it. One definition is based on the L1-norm distance between probability distributions, the other on information theory. We prove that the two definitions are essentially equivalent. We also show that statistical counterparts of definitions of computational secrecy are essentially equivalent......We present and compare definitions of "statistically hiding" protocols, and we propose a novel statistically hiding commitment scheme. Informally, a protocol statistically hides a secret if a computationally unlimited adversary who conducts the protocol with the owner of the secret learns almost...... to our main definitions. Commitment schemes are an important cryptologic primitive. Their purpose is to commit one party to a certain value, while hiding this value from the other party until some later time. We present a statistically hiding commitment scheme allowing commitment to many bits...

  2. Expansion of Adult Human Pancreatic Tissue Yields Organoids Harboring Progenitor Cells with Endocrine Differentiation Potential

    Directory of Open Access Journals (Sweden)

    Cindy J.M. Loomans

    2018-03-01

    Full Text Available Summary: Generating an unlimited source of human insulin-producing cells is a prerequisite to advance β cell replacement therapy for diabetes. Here, we describe a 3D culture system that supports the expansion of adult human pancreatic tissue and the generation of a cell subpopulation with progenitor characteristics. These cells display high aldehyde dehydrogenase activity (ALDHhi, express pancreatic progenitors markers (PDX1, PTF1A, CPA1, and MYC, and can form new organoids in contrast to ALDHlo cells. Interestingly, gene expression profiling revealed that ALDHhi cells are closer to human fetal pancreatic tissue compared with adult pancreatic tissue. Endocrine lineage markers were detected upon in vitro differentiation. Engrafted organoids differentiated toward insulin-positive (INS+ cells, and circulating human C-peptide was detected upon glucose challenge 1 month after transplantation. Engrafted ALDHhi cells formed INS+ cells. We conclude that adult human pancreatic tissue has potential for expansion into 3D structures harboring progenitor cells with endocrine differentiation potential. : In the context of β cell replacement therapy for diabetes, de Koning and colleagues describe a 3D culture platform that supports ex vivo expansion of human pancreatic tissue as organoids. These organoids harbor a subpopulation of ALDHhi cells that display proliferative capacity and can differentiate to an endocrine fate. Keywords: pancreas, organoid, human, ALDH, endocrine differentiation, beta cells, insulin, progenitor, fetal, diabetes

  3. Effects of topography on the functional development of human neural progenitor cells.

    Science.gov (United States)

    Wu, Ze-Zhi; Kisaalita, William S; Wang, Lina; Zachman, Angela L; Zhao, Yiping; Hasneen, Kowser; Machacek, Dave; Stice, Steven L

    2010-07-01

    We have fabricated a topographical substrate with a packed polystyrene bead array for the development of cell-based assay systems targeting voltage-gated calcium channels (VGCCs). Human neural progenitor cells (H945RB.3) cultured on both flat and topographical substrates were analyzed in terms of morphological spreading, neuronal commitment, resting membrane potential (V(m)) establishment and VGCC function development. We found, by SEM imaging, that arrayed substrates, formed with both sub-micrometer (of 0.51 microm in mean diameter) and micrometer (of 1.98 microm in mean diameter) beads, were capable of promoting the spreading of the progenitor cells as compared with the flat polystyrene surfaces. With the micrometer beads, it was found that arrayed substrates facilitated the neural progenitor cells' maintenance of less negative V(m) values upon differentiation with bFGF starvation, which favored predominant neuronal commitment. Almost all the progenitor cells were responsive to 50 mM K(+) depolarization with an increase in [Ca(2+)](i) either before or upon differentiation, suggesting the expression of functional VGCCs. Compared to the flat polystyrene surfaces, microbead arrayed substrates facilitated the development of higher VGCC responsiveness by the progenitor cells upon differentiation. The enhancement of both VGCC responsiveness and cell spreading by arrays of micrometer beads was most significant on day 14 into differentiation, which was the latest time point of measurement in this study. This study thus rationalized the possibility for future substrate topography engineering to manipulate ion channel function and to meet the challenge of low VGCC responsiveness found in early drug discovery.

  4. Proinflammatory Mediators Enhance the Osteogenesis of Human Mesenchymal Stem Cells after Lineage Commitment

    NARCIS (Netherlands)

    Croes, Michiel; Oner, F Cumhur; Kruyt, Moyo C; Blokhuis, Taco J; Bastian, Okan; Dhert, Wouter J A|info:eu-repo/dai/nl/10261847X; Alblas, Jacqueline

    2015-01-01

    Several inflammatory processes underlie excessive bone formation, including chronic inflammation of the spine, acute infections, or periarticular ossifications after trauma. This suggests that local factors in these conditions have osteogenic properties. Mesenchymal stem cells (MSCs) and their

  5. Human natural killer cell committed thymocytes and their relation to the T cell lineage

    NARCIS (Netherlands)

    Sánchez, M. J.; Spits, H.; Lanier, L. L.; Phillips, J. H.

    1993-01-01

    Recent studies have demonstrated that mature natural killer (NK) cells can be grown from human triple negative (TN; CD3-, CD4-, CD8-) thymocytes, suggesting that a common NK/T cell precursor exists within the thymus that can give rise to both NK cells and T cells under appropriate conditions. In the

  6. Tracking differentiating neural progenitors in pluripotent cultures using microRNA-regulated lentiviral vectors.

    Science.gov (United States)

    Sachdeva, Rohit; Jönsson, Marie E; Nelander, Jenny; Kirkeby, Agnete; Guibentif, Carolina; Gentner, Bernhard; Naldini, Luigi; Björklund, Anders; Parmar, Malin; Jakobsson, Johan

    2010-06-22

    In this study, we have used a microRNA-regulated lentiviral reporter system to visualize and segregate differentiating neuronal cells in pluripotent cultures. Efficient suppression of transgene expression, specifically in undifferentiated pluripotent cells, was achieved by using a lentiviral vector expressing a fluorescent reporter gene regulated by microRNA-292. Using this strategy, it was possible to track progeny from murine ES, human ES cells, and induced pluripotent stem cells as they differentiated toward the neural lineage. In addition, this strategy was successfully used to FACS purify neuronal progenitors for molecular analysis and transplantation. FACS enrichment reduced tumor formation and increased survival of ES cell-derived neuronal progenitors after transplantation. The properties and versatility of the microRNA-regulated vectors allows broad use of these vectors in stem cell applications.

  7. Osteoblast Production by Reserved Progenitor Cells in Zebrafish Bone Regeneration and Maintenance.

    Science.gov (United States)

    Ando, Kazunori; Shibata, Eri; Hans, Stefan; Brand, Michael; Kawakami, Atsushi

    2017-12-04

    Mammals cannot re-form heavily damaged bones as in large fracture gaps, whereas zebrafish efficiently regenerate bones even after amputation of appendages. However, the source of osteoblasts that mediate appendage regeneration is controversial. Several studies in zebrafish have shown that osteoblasts are generated by dedifferentiation of existing osteoblasts at injured sites, but other observations suggest that de novo production of osteoblasts also occurs. In this study, we found from cell-lineage tracing and ablation experiments that a group of cells reserved in niches serves as osteoblast progenitor cells (OPCs) and has a significant role in fin ray regeneration. Besides regeneration, OPCs also supply osteoblasts for normal bone maintenance. We further showed that OPCs are derived from embryonic somites, as is the case with embryonic osteoblasts, and are replenished from mesenchymal precursors in adult zebrafish. Our findings reveal that reserved progenitors are a significant and complementary source of osteoblasts for zebrafish bone regeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Progenitor's Signatures in Type Ia Supernova Remnants

    NARCIS (Netherlands)

    Chiotellis, A.; Kosenko, D.; Schure, K.M.; Vink, J.

    2013-01-01

    The remnants of Type Ia supernovae (SNe Ia) can provide important clues about their progenitor histories. We discuss two well-observed supernova remnants (SNRs) that are believed to have resulted from SNe Ia, and use various tools to shed light on the possible progenitor histories. We find that

  9. Pulpal progenitors and dentin repair.

    Science.gov (United States)

    Harichane, Y; Hirata, A; Dimitrova-Nakov, S; Granja, I; Goldberg, A; Kellermann, O; Poliard, A

    2011-07-01

    Mesenchymal stem cells are present in the dental pulp. They have been shown to contribute to dentin-like tissue formation in vitro and to participate in bone repair after a mandibular lesion. However, their capacity to contribute efficiently to reparative dentin formation after pulp lesion has never been explored. After pulp exposure, we have identified proliferative cells within 3 zones. In the crown, zone I is near the cavity, and zone II corresponds to the isthmus between the mesial and central pulp. In the root, zone III, near the apex, at a distance from the inflammatory site, contains mitotic stromal cells which may represent a source of progenitor cells. Stem-cell-based strategies are promising treatments for tissue injury in dentistry. Our experiments focused on (1) location of stem cells induced to leave their quiescent state early after pulp injury and (2) implantation of pulp progenitors, a substitute for classic endodontic treatments, paving the way for pulp stem-cell-based therapies.

  10. Transplanting oligodendrocyte progenitors into the adult CNS

    International Nuclear Information System (INIS)

    Franklin, R.J.M.; Blakemore, W.F.; Cambridge Univ.

    1997-01-01

    This review covers a number of aspects of the behaviour of oligodendrocyte progenitors following transplantation into the adult CNS. First, an account is given of the ability of transplanted oligodendrocyte progenitors, grown in tissue culture in the presence of PDGF and bFGF, to extensively remyelinate focal areas of persistent demyelination. Secondly, we describe how transplanted clonal cell lines of oligodendrocyte progenitors will differentiate in to astrocytes as will oligodendrocytes following transplantation into pathological environments in which both oligodendrocytes and astrocytes are absent, thereby manifesting the bipotentially demonstrable in vitro but not during development. Finally, a series of studies examining the migratory behaviour of transplanted oligodendrocyte progenitors (modelled using the oligodendrocyte progenitor cell line CG4) are described. (author)

  11. Cord blood-derived macrophage-lineage cells rapidly stimulate osteoblastic maturation in mesenchymal stem cells in a glycoprotein-130 dependent manner.

    Directory of Open Access Journals (Sweden)

    Tania J Fernandes

    Full Text Available In bone, depletion of osteoclasts reduces bone formation in vivo, as does osteal macrophage depletion. How osteoclasts and macrophages promote the action of bone forming osteoblasts is, however, unclear. Since recruitment and differentiation of multi-potential stromal cells/mesenchymal stem cells (MSC generates new active osteoblasts, we investigated whether human osteoclasts and macrophages (generated from cord blood-derived hematopoietic progenitors induce osteoblastic maturation in adipose tissue-derived MSC. When treated with an osteogenic stimulus (ascorbate, dexamethasone and β-glycerophosphate these MSC form matrix-mineralising, alkaline phosphatase-expressing osteoblastic cells. Cord blood-derived progenitors were treated with macrophage colony stimulating factor (M-CSF to form immature proliferating macrophages, or with M-CSF plus receptor activator of NFκB ligand (RANKL to form osteoclasts; culture medium was conditioned for 3 days by these cells to study their production of osteoblastic factors. Both osteoclast- and macrophage-conditioned medium (CM greatly enhanced MSC osteoblastic differentiation in both the presence and absence of osteogenic medium, evident by increased alkaline phosphatase levels within 4 days and increased mineralisation within 14 days. These CM effects were completely ablated by antibodies blocking gp130 or oncostatin M (OSM, and OSM was detectable in both CM. Recombinant OSM very potently stimulated osteoblastic maturation of these MSC and enhanced bone morphogenetic protein-2 (BMP-2 actions on MSC. To determine the influence of macrophage activation on this OSM-dependent activity, CM was collected from macrophage populations treated with M-CSF plus IL-4 (to induce alternative activation or with GM-CSF, IFNγ and LPS to cause classical activation. CM from IL-4 treated macrophages stimulated osteoblastic maturation in MSC, while CM from classically-activated macrophages did not. Thus, macrophage-lineage cells

  12. Exploiting Heparan Sulfate Proteoglycans in Human Neurogenesis—Controlling Lineage Specification and Fate

    Directory of Open Access Journals (Sweden)

    Chieh Yu

    2017-10-01

    Full Text Available Unspecialized, self-renewing stem cells have extraordinary application to regenerative medicine due to their multilineage differentiation potential. Stem cell therapies through replenishing damaged or lost cells in the injured area is an attractive treatment of brain trauma and neurodegenerative neurological disorders. Several stem cell types have neurogenic potential including neural stem cells (NSCs, embryonic stem cells (ESCs, induced pluripotent stem cells (iPSCs, and mesenchymal stem cells (MSCs. Currently, effective use of these cells is limited by our lack of understanding and ability to direct lineage commitment and differentiation of neural lineages. Heparan sulfate proteoglycans (HSPGs are ubiquitous proteins within the stem cell microenvironment or niche and are found localized on the cell surface and in the extracellular matrix (ECM, where they interact with numerous signaling molecules. The glycosaminoglycan (GAG chains carried by HSPGs are heterogeneous carbohydrates comprised of repeating disaccharides with specific sulfation patterns that govern ligand interactions to numerous factors including the fibroblast growth factors (FGFs and wingless-type MMTV integration site family (Wnts. As such, HSPGs are plausible targets for guiding and controlling neural stem cell lineage fate. In this review, we provide an overview of HSPG family members syndecans and glypicans, and perlecan and their role in neurogenesis. We summarize the structural changes and subsequent functional implications of heparan sulfate as cells undergo neural lineage differentiation as well as outline the role of HSPG core protein expression throughout mammalian neural development and their function as cell receptors and co-receptors. Finally, we highlight suitable biomimetic approaches for exploiting the role of HSPGs in mammalian neurogenesis to control and tailor cell differentiation into specific lineages. An improved ability to control stem cell specific neural

  13. Cdc42 controls progenitor cell differentiation and beta-catenin turnover in skin

    DEFF Research Database (Denmark)

    Wu, Xunwei; Quondamatteo, Fabio; Lefever, Tine

    2006-01-01

    for differentiation of skin progenitor cells into HF lineage and that it regulates the turnover of beta-catenin. In the absence of Cdc42, degradation of beta-catenin was increased corresponding to a decreased phosphorylation of GSK3beta at Ser 9 and an increased phosphorylation of axin, which is known to be required...... for binding of beta-catenin to the degradation machinery. Cdc42-mediated regulation of beta-catenin turnover was completely dependent on PKCzeta, which associated with Cdc42, Par6, and Par3. These data suggest that Cdc42 regulation of beta-catenin turnover is important for terminal differentiation of HF...

  14. Sox1 marks an activated neural stem/progenitor cell in the hippocampus

    OpenAIRE

    Venere, Monica; Han, Young-Goo; Bell, Robert; Song, Jun S.; Alvarez-Buylla, Arturo; Blelloch, Robert

    2012-01-01

    The dentate gyrus of the hippocampus continues generating new neurons throughout life. These neurons originate from radial astrocytes within the subgranular zone (SGZ). Here, we find that Sox1, a member of the SoxB1 family of transcription factors, is expressed in a subset of radial astrocytes. Lineage tracing using Sox1-tTA;tetO-Cre;Rosa26 reporter mice shows that the Sox1-expressing cells represent an activated neural stem/progenitor population that gives rise to most if not all newly born ...

  15. Heritable and lineage-specific gene knockdown in zebrafish embryo.

    Directory of Open Access Journals (Sweden)

    Mei Dong

    Full Text Available BACKGROUND: Reduced expression of developmentally important genes and tumor suppressors due to haploinsufficiency or epigenetic suppression has been shown to contribute to the pathogenesis of various malignancies. However, methodology that allows spatio-temporally knockdown of gene expression in various model organisms such as zebrafish has not been well established, which largely limits the potential of zebrafish as a vertebrate model of human malignant disorders. PRINCIPAL FINDING: Here, we report that multiple copies of small hairpin RNA (shRNA are expressed from a single transcript that mimics the natural microRNA-30e precursor (mir-shRNA. The mir-shRNA, when microinjected into zebrafish embryos, induced an efficient knockdown of two developmentally essential genes chordin and alpha-catenin in a dose-controllable fashion. Furthermore, we designed a novel cassette vector to simultaneously express an intronic mir-shRNA and a chimeric red fluorescent protein driven by lineage-specific promoter, which efficiently reduced the expression of a chromosomally integrated reporter gene and an endogenously expressed gata-1 gene in the developing erythroid progenitors and hemangioblasts, respectively. SIGNIFICANCE: This methodology provides an invaluable tool to knockdown developmental important genes in a tissue-specific manner or to establish animal models, in which the gene dosage is critically important in the pathogenesis of human disorders. The strategy should be also applicable to other model organisms.

  16. β-catenin/Wnt signaling controls progenitor fate in the developing and regenerating zebrafish retina

    Directory of Open Access Journals (Sweden)

    Meyers Jason R

    2012-08-01

    Full Text Available Abstract Background The zebrafish retina maintains two populations of stem cells: first, the germinal zone or ciliary marginal zone (CMZ contains multipotent retinal progenitors that add cells to the retinal periphery as the fish continue to grow; second, radial glia (Müller cells occasionally divide asymmetrically to generate committed progenitors that differentiate into rod photoreceptors, which are added interstitially throughout the retina with growth. Retinal injury stimulates Müller glia to dedifferentiate, re-enter the cell cycle, and generate multipotent retinal progenitors similar to those in the CMZ to replace missing neurons. The specific signals that maintain these two distinct populations of endogenous retinal stem cells are not understood. Results We used genetic and pharmacological manipulation of the β-catenin/Wnt signaling pathway to show that it is required to maintain proliferation in the CMZ and that hyperstimulation of β-catenin/Wnt signaling inhibits normal retinal differentiation and expands the population of proliferative retinal progenitors. To test whether similar effects occur during regeneration, we developed a method for making rapid, selective photoreceptor ablations in larval zebrafish with intense light. We found that dephosphorylated β-catenin accumulates in Müller glia as they re-enter the cell cycle following injury, but not in Müller glia that remain quiescent. Activation of Wnt signaling is required for regenerative proliferation, and hyperstimulation results in loss of Müller glia from the INL as all proliferative cells move into the ONL. Conclusions β-catenin/Wnt signaling is thus required for the maintenance of retinal progenitors during both initial development and lesion-induced regeneration, and is sufficient to prevent differentiation of those progenitors and maintain them in a proliferative state. This suggests that the β-catenin/Wnt cascade is part of the shared molecular circuitry that

  17. Accumulation of multipotent progenitors with a basal differentiation bias during aging of human mammary epithelia

    DEFF Research Database (Denmark)

    Garbe, James C; Pepin, Francois; Pelissier, Fanny A

    2012-01-01

    of the cellular and molecular mechanisms that underlies these observations is lacking. In this study, we generated a large collection of normal human mammary epithelial cell strains from women ages 16 to 91 years, derived from primary tissues, to investigate the molecular changes that occur in aging breast cells....... We found that in finite lifespan cultured and uncultured epithelial cells, aging is associated with a reduction of myoepithelial cells and an increase in luminal cells that express keratin 14 and integrin-a6, a phenotype that is usually expressed exclusively in myoepithelial cells in women younger...... than 30 years. Changes to the luminal lineage resulted from age-dependent expansion of defective multipotent progenitors that gave rise to incompletely differentiated luminal or myoepithelial cells. The aging process therefore results in both a shift in the balance of luminal/myoepithelial lineages...

  18. The dimensionality of professional commitment

    OpenAIRE

    Jeffrey J. Bagraim

    2003-01-01

    This paper examines the dimensionality of professional commitment amongst a sample of 240 South African actuaries. Data were obtained, via a mailed questionnaire, from members of the South African Actuarial Society employed in the financial services industry. Statistical analysis conducted on the data showed that the 3-component model first proposed by Meyer, Allen and Smith (1993) is appropriate for understanding professional commitment amongst South African professionals. The analysis also ...

  19. Alcohol myopia and goal commitment

    OpenAIRE

    Sevincer, A. Timur; Oettingen, Gabriele

    2014-01-01

    According to alcohol myopia theory, acute alcohol consumption leads people to disproportionally focus on the salient rather than the peripheral aspects of a situation. We summarize various studies exploring how myopic processes resulting from acute alcohol intake affect goal commitment. After consuming alcohol student participants felt strongly committed to an important personal goal even though they had low expectations of successfully attaining the goal. However, once intoxicated participan...

  20. Combining G-CSF with a blockade of adhesion strongly improves the reconstitutive capacity of mobilized hematopoietic progenitor cells.

    Science.gov (United States)

    Christ, O; Kronenwett, R; Haas, R; Zöller, M

    2001-03-01

    Mobilization of hematopoietic progenitor cells is achieved mainly by application of growth factors and, more recently, by blockade of adhesion. In this report, we describe the advantages of a combined treatment with granulocyte colony-stimulating factor (G-CSF) and anti-VLA4 (CD49d)/anti-CD44 as compared to treatment with the individual components. Mobilization by intravenous injection of anti-CD44, anti-VLA4, or G-CSF was controlled in spleen and bone marrow with regard to frequencies of multipotential colony-forming unit (C-CFU), marrow repopulating ability, long-term reconstitution, recovery of myelopoiesis, and regain of immunocompetence. Mobilization by anti-CD44 had a strong effect on expansion of early progenitor cells in the bone marrow, while the recovery in the spleen was poor. In anti-CD49d-mobilized noncommitted and committed progenitors, progenitor expansion was less pronounced, but settlement in the spleen was quite efficient. Thus, anti-CD44 and anti-CD49d differently influenced mobilization. Accordingly, mobilization and recovery after transfer were improved by combining anti-CD44 with anti-CD49d treatment. Mobilization by G-CSF was most efficient with respect to recovery of progenitor cells in the spleen. However, when transferring G-CSF-mobilized cells, regain of immunocompetence was strongly delayed. This disadvantage could be overridden when progenitor cells were mobilized via blockade of adhesion and when expansion of these mobilized progenitor cells was supported by low-dose G-CSF only during the last 24 hours before transfer. Mobilization of pluripotent progenitor cells via antibody blockade of CD44 or CD49d or via G-CSF relies on distinct mechanisms. Therefore, the reconstitutive capacity of a transplant can be significantly improved by mobilization regimens combining antibody with low-dose G-CSF treatment.

  1. Alcohol myopia and goal commitment

    Directory of Open Access Journals (Sweden)

    A. Timur Sevincer

    2014-03-01

    Full Text Available According to alcohol-myopia theory, acute alcohol consumption leads people to disproportionally focus on the salient rather than the peripheral aspects of a situation. We summarize various studies exploring how myopic processes resulting from acute alcohol intake affect goal commitment. After consuming alcohol student participants felt strongly committed to an important personal goal even though they had low expectations of successfully attaining the goal. However, once intoxicated participants were sober again (i.e., not myopic anymore they failed to act on their goal commitment. In line with alcohol-myopia theory, strong goal commitment as a result of alcohol intake was mediated by intoxicated (vs. sober participants disproportionally focusing on the desirability rather than the feasibility of their goal. Further supporting alcohol-myopia theory, when the low feasibility of attaining a particular goal was experimentally made salient (either explicitly or implicitly by subliminal priming, intoxicated participants felt less committed than those who consumed a placebo. We discuss these effects of acute alcohol intake in the context of research on the effects of chronic alcohol consumption on goal commitment.

  2. New Lineage of Lassa Virus, Togo, 2016

    Science.gov (United States)

    Whitmer, Shannon L.M.; Strecker, Thomas; Cadar, Daniel; Dienes, Hans-Peter; Faber, Kelly; Patel, Ketan; Brown, Shelley M.; Davis, William G.; Klena, John D.; Rollin, Pierre E.; Schmidt-Chanasit, Jonas; Fichet-Calvet, Elisabeth; Noack, Bernd; Emmerich, Petra; Rieger, Toni; Wolff, Svenja; Fehling, Sarah Katharina; Eickmann, Markus; Mengel, Jan Philipp; Schultze, Tilman; Hain, Torsten; Ampofo, William; Bonney, Kofi; Aryeequaye, Juliana Naa Dedei; Ribner, Bruce; Varkey, Jay B.; Mehta, Aneesh K.; Lyon, G. Marshall; Kann, Gerrit; De Leuw, Philipp; Schuettfort, Gundolf; Stephan, Christoph; Wieland, Ulrike; Fries, Jochen W.U.; Kochanek, Matthias; Kraft, Colleen S.; Wolf, Timo; Nichol, Stuart T.; Becker, Stephan; Ströher, Ute

    2018-01-01

    We describe a strain of Lassa virus representing a putative new lineage that was isolated from a cluster of human infections with an epidemiologic link to Togo. This finding extends the known range of Lassa virus to Togo. PMID:29460758

  3. Portal inflammation during NAFLD is frequent and associated with the early phases of putative hepatic progenitor cell activation.

    Science.gov (United States)

    Carotti, Simone; Vespasiani-Gentilucci, Umberto; Perrone, Giuseppe; Picardi, Antonio; Morini, Sergio

    2015-11-01

    We investigated whether portal tract inflammation observed in non-alcoholic fatty liver disease (NAFLD) is associated with hepatic progenitor cell compartment activation, as thoroughly evaluated with different markers of the staminal lineage. Fifty-two patients with NAFLD were studied. NAFLD activity score, fibrosis and portal inflammation were histologically evaluated. Putative hepatic progenitor cells, intermediate hepatobiliary cells and bile ductules/interlobular bile ducts were evaluated by immunohistochemistry for cytokeratin (CK)-7, CK-19 and epithelial cell adhesion molecule (EpCAM), and a hepatic progenitor cell compartment score was derived. Hepatic stellate cell and myofibroblast activity was determined by immunohistochemistry for α-smooth muscle actin. Portal inflammation was absent in a minority of patients, mild in 40% of cases and more than mild in about half of patients, showing a strong correlation with fibrosis (r=0.76, pcells (r=0.48, pcells (r=0.6, pcell compartment activation were associated with portal inflammation by univariate analysis. In the multivariate model, the only variable independently associated with portal inflammation was hepatic progenitor cell compartment activation (OR 3.7, 95% CI 1.1 to 12.6). Portal inflammation is frequent during NAFLD and strongly associated with activation of putative hepatic progenitor cells since the first steps of their differentiation, portal myofibroblast activity and fibrosis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  4. Wnt inhibition promotes vascular specification of embryonic cardiac progenitors.

    Science.gov (United States)

    Reichman, David E; Park, Laura; Man, Limor; Redmond, David; Chao, Kenny; Harvey, Richard P; Taketo, Makoto M; Rosenwaks, Zev; James, Daylon

    2018-01-08

    Several studies have demonstrated a multiphasic role for Wnt signaling during embryonic cardiogenesis and developed protocols that enrich for cardiac derivatives during in vitro differentiation of human pluripotent stem cells (hPSCs). However, few studies have investigated the role of Wnt signaling in the specification of cardiac progenitor cells (CPCs) toward downstream fates. Using transgenic mice and hPSCs, we tracked endothelial cells (ECs) that originated from CPCs expressing NKX2.5. Analysis of EC-fated CPCs at discrete phenotypic milestones during hPSC differentiation identified reduced Wnt activity as a hallmark of EC specification, and the enforced activation or inhibition of Wnt reduced or increased, respectively, the degree of vascular commitment within the CPC population during both hPSC differentiation and mouse embryogenesis. Wnt5a, which has been shown to exert an inhibitory influence on Wnt signaling during cardiac development, was dynamically expressed during vascular commitment of hPSC-derived CPCs, and ectopic Wnt5a promoted vascular specification of hPSC-derived and mouse embryonic CPCs. © 2018. Published by The Company of Biologists Ltd.

  5. Lineage Selection and the Maintenance of Sex

    Science.gov (United States)

    de Vienne, Damien M.; Giraud, Tatiana; Gouyon, Pierre-Henri

    2013-01-01

    Sex predominates in eukaryotes, despite its short-term disadvantage when compared to asexuality. Myriad models have suggested that short-term advantages of sex may be sufficient to counterbalance its twofold costs. However, despite decades of experimental work seeking such evidence, no evolutionary mechanism has yet achieved broad recognition as explanation for the maintenance of sex. We explore here, through lineage-selection models, the conditions favouring the maintenance of sex. In the first model, we allowed the rate of transition to asexuality to evolve, to determine whether lineage selection favoured species with the strongest constraints preventing the loss of sex. In the second model, we simulated more explicitly the mechanisms underlying the higher extinction rates of asexual lineages than of their sexual counterparts. We linked extinction rates to the ecological and/or genetic features of lineages, thereby providing a formalisation of the only figure included in Darwin's “The origin of species”. Our results reinforce the view that the long-term advantages of sex and lineage selection may provide the most satisfactory explanations for the maintenance of sex in eukaryotes, which is still poorly recognized, and provide figures and a simulation website for training and educational purposes. Short-term benefits may play a role, but it is also essential to take into account the selection of lineages for a thorough understanding of the maintenance of sex. PMID:23825582

  6. PTEN Signaling in the Postnatal Perivascular Progenitor Niche Drives Medulloblastoma Formation.

    Science.gov (United States)

    Zhu, Guo; Rankin, Sherri L; Larson, Jon D; Zhu, Xiaoyan; Chow, Lionel M L; Qu, Chunxu; Zhang, Jinghui; Ellison, David W; Baker, Suzanne J

    2017-01-01

    Loss of the tumor suppressor gene PTEN exerts diverse outcomes on cancer in different developmental contexts. To gain insight into the effect of its loss on outcomes in the brain, we conditionally inactivated the murine Pten gene in neonatal neural stem/progenitor cells. Pten inactivation created an abnormal perivascular proliferative niche in the cerebellum that persisted in adult animals but did not progress to malignancy. Proliferating cells showed undifferentiated morphology and expressed the progenitor marker Nestin but not Math1, a marker of committed granule neuron progenitors. Codeletion of Pten and Trp53 resulted in fully penetrant medulloblastoma originating from the perivascular niche, which exhibited abnormal blood vessel networks and advanced neuronal differentiation of tumor cells. EdU pulse-chase experiments demonstrated a perivascular cancer stem cell population in Pten/Trp53 double mutant medulloblastomas. Genetic analyses revealed recurrent somatic inactivations of the tumor suppressor gene Ptch1 and a recapitulation of the sonic hedgehog subgroup of human medulloblastomas. Overall, our results showed that PTEN acts to prevent the proliferation of a progenitor niche in postnatal cerebellum predisposed to oncogenic induction of medulloblastoma. Cancer Res; 77(1); 123-33. ©2016 AACR. ©2016 American Association for Cancer Research.

  7. Splenomegaly, myeloid lineage expansion and increased osteoclastogenesis in osteogenesis imperfecta murine.

    Science.gov (United States)

    Matthews, Brya G; Roeder, Emilie; Wang, Xi; Aguila, Hector Leonardo; Lee, Sun-Kyeong; Grcevic, Danka; Kalajzic, Ivo

    2017-10-01

    Osteogenesis imperfecta (OI) is a disease caused by defects in type I collagen production that results in brittle bones. While the pathology is mainly caused by defects in the osteoblast lineage, there is also elevated bone resorption by osteoclasts resulting in high bone turnover in severe forms of the disease. Osteoclasts originate from hematopoietic myeloid cells, however changes in hematopoiesis have not been previously documented in OI. In this study, we evaluated hematopoietic lineage distribution and osteoclast progenitor cell frequency in bone marrow, spleen and peripheral blood of osteogenesis imperfecta murine (OIM) mice, a model of severe OI. We found splenomegaly in all ages examined, and expansion of myeloid lineage cells (CD11b + ) in bone marrow and spleen of 7-9week old male OIM animals. OIM spleens also showed an increased frequency of purified osteoclast progenitors. This phenotype is suggestive of chronic inflammation. Isolated osteoclast precursors from both spleen and bone marrow formed osteoclasts more rapidly than wild-type controls. We found that serum TNFα levels were increased in OIM, as was IL1α in OIM females. We targeted inflammation therapeutically by treating growing animals with murine TNFR2:Fc, a compound that blocks TNFα activity. Anti-TNFα treatment marginally decreased spleen mass in OIM females, but failed to reduce bone resorption, or improve bone parameters or fracture rate in OIM animals. We have demonstrated that OIM mice have changes in their hematopoietic system, and form osteoclasts more rapidly even in the absence of OI osteoblast signals, however therapy targeting TNFα did not improve disease parameters. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Characterization of vascular endothelial progenitor cells from chicken bone marrow

    Directory of Open Access Journals (Sweden)

    Bai Chunyu

    2012-05-01

    Full Text Available Abstract Background Endothelial progenitor cells (EPC are a type of stem cell used in the treatment of atherosclerosis, vascular injury and regeneration. At present, most of the EPCs studied are from human and mouse, whereas the study of poultry-derived EPCs has rarely been reported. In the present study, chicken bone marrow-derived EPCs were isolated and studied at the cellular level using immunofluorescence and RT-PCR. Results We found that the majority of chicken EPCs were spindle shaped. The growth-curves of chicken EPCs at passages (P 1, -5 and -9 were typically “S”-shaped. The viability of chicken EPCs, before and after cryopreservation was 92.2% and 81.1%, respectively. Thus, cryopreservation had no obvious effects on the viability of chicken EPCs. Dil-ac-LDL and FITC-UAE-1 uptake assays and immunofluorescent detection of the cell surface markers CD34, CD133, VEGFR-2 confirmed that the cells obtained in vitro were EPCs. Observation of endothelial-specific Weibel-Palade bodies using transmission electron microscopy further confirmed that the cells were of endothelial lineage. In addition, chicken EPCs differentiated into endothelial cells and smooth muscle cells upon induction with VEGF and PDGF-BB, respectively, suggesting that the chicken EPCs retained multipotency in vitro. Conclusions These results suggest that chicken EPCs not only have strong self-renewal capacity, but also the potential to differentiate into endothelial and smooth muscle cells. This research provides theoretical basis and experimental evidence for potential therapeutic application of endothelial progenitor cells in the treatment of atherosclerosis, vascular injury and diabetic complications.

  9. Lineage relationship of prostate cancer cell types based on gene expression

    Directory of Open Access Journals (Sweden)

    Ware Carol B

    2011-05-01

    Full Text Available Abstract Background Prostate tumor heterogeneity is a major factor in disease management. Heterogeneity could be due to multiple cancer cell types with distinct gene expression. Of clinical importance is the so-called cancer stem cell type. Cell type-specific transcriptomes are used to examine lineage relationship among cancer cell types and their expression similarity to normal cell types including stem/progenitor cells. Methods Transcriptomes were determined by Affymetrix DNA array analysis for the following cell types. Putative prostate progenitor cell populations were characterized and isolated by expression of the membrane transporter ABCG2. Stem cells were represented by embryonic stem and embryonal carcinoma cells. The cancer cell types were Gleason pattern 3 (glandular histomorphology and pattern 4 (aglandular sorted from primary tumors, cultured prostate cancer cell lines originally established from metastatic lesions, xenografts LuCaP 35 (adenocarcinoma phenotype and LuCaP 49 (neuroendocrine/small cell carcinoma grown in mice. No detectable gene expression differences were detected among serial passages of the LuCaP xenografts. Results Based on transcriptomes, the different cancer cell types could be clustered into a luminal-like grouping and a non-luminal-like (also not basal-like grouping. The non-luminal-like types showed expression more similar to that of stem/progenitor cells than the luminal-like types. However, none showed expression of stem cell genes known to maintain stemness. Conclusions Non-luminal-like types are all representatives of aggressive disease, and this could be attributed to the similarity in overall gene expression to stem and progenitor cell types.

  10. Culture conditions have an impact on the maturation of traceable, transplantable mouse embryonic stem cell-derived otic progenitor cells.

    Science.gov (United States)

    Abboud, Nesrine; Fontbonne, Arnaud; Watabe, Isabelle; Tonetto, Alain; Brezun, Jean Michel; Feron, François; Zine, Azel

    2017-09-01

    The generation of replacement inner ear hair cells (HCs) remains a challenge and stem cell therapy holds the potential for developing therapeutic solutions to hearing and balance disorders. Recent developments have made significant strides in producing mouse otic progenitors using cell culture techniques to initiate HC differentiation. However, no consensus has been reached as to efficiency and therefore current methods remain unsatisfactory. In order to address these issues, we compare the generation of otic and HC progenitors from embryonic stem (ES) cells in two cell culture systems: suspension vs. adherent conditions. In the present study, an ES cell line derived from an Atoh1-green fluorescent protein (GFP) transgenic mouse was used to track the generation of otic progenitors, initial HCs and to compare these two differentiation systems. We used a two-step short-term differentiation method involving an induction period of 5 days during which ES cells were cultured in the presence of Wnt/transforming growth factor TGF-β inhibitors and insulin-like growth factor IGF-1 to suppress mesoderm and reinforce presumptive ectoderm and otic lineages. The generated embryoid bodies were then differentiated in medium containing basic fibroblast growth factor (bFGF) for an additional 5 days using either suspension or adherent culture methods. Upon completion of differentiation, quantitative polymerase chain reaction analysis and immunostaining monitored the expression of otic/HC progenitor lineage markers. The results indicate that cells differentiated in suspension cultures produced cells expressing otic progenitor/HC markers at a higher efficiency compared with the production of these cell types within adherent cultures. Furthermore, we demonstrated that a fraction of these cells can incorporate into ototoxin-injured mouse postnatal cochlea explants and express MYO7A after transplantation. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons

  11. Transplantation of rat embryonic stem cell-derived retinal progenitor cells preserves the retinal structure and function in rat retinal degeneration.

    Science.gov (United States)

    Qu, Zepeng; Guan, Yuan; Cui, Lu; Song, Jian; Gu, Junjie; Zhao, Hanzhi; Xu, Lei; Lu, Lixia; Jin, Ying; Xu, Guo-Tong

    2015-11-09

    Degenerative retinal diseases like age-related macular degeneration (AMD) are the leading cause of blindness. Cell transplantation showed promising therapeutic effect for such diseases, and embryonic stem cell (ESC) is one of the sources of such donor cells. Here, we aimed to generate retinal progenitor cells (RPCs) from rat ESCs (rESCs) and to test their therapeutic effects in rat model. The rESCs (DA8-16) were cultured in N2B27 medium with 2i, and differentiated to two types of RPCs following the SFEBq method with modifications. For rESC-RPC1, the cells were switched to adherent culture at D10, while for rESC-RPC2, the suspension culture was maintained to D14. Both RPCs were harvested at D16. Primary RPCs were obtained from P1 SD rats, and some of them were labeled with EGFP by infection with lentivirus. To generate Rax::EGFP knock-in rESC lines, TALENs were engineered to facilitate homologous recombination in rESCs, which were cotransfected with the targeting vector and TALEN vectors. The differentiated cells were analyzed with live image, immunofluorescence staining, flow cytometric analysis, gene expression microarray, etc. RCS rats were used to mimic the degeneration of retina and test the therapeutic effects of subretinally transplanted donor cells. The structure and function of retina were examined. We established two protocols through which two types of rESC-derived RPCs were obtained and both contained committed retina lineage cells and some neural progenitor cells (NPCs). These rESC-derived RPCs survived in the host retinas of RCS rats and protected the retinal structure and function in early stage following the transplantation. However, the glia enriched rESC-RPC1 obtained through early and longer adherent culture only increased the b-wave amplitude at 4 weeks, while the longer suspension culture gave rise to evidently neuronal differentiation in rESC-RPC2 which significantly improved the visual function of RCS rats. We have successfully differentiated

  12. Promoted neuronal differentiation after activation of alpha4/beta2 nicotinic acetylcholine receptors in undifferentiated neural progenitors.

    Directory of Open Access Journals (Sweden)

    Takeshi Takarada

    defective of NMDA receptor subunit-1, nicotine was still effective in significantly inhibiting the proliferation. CONCLUSIONS/SIGNIFICANCE: Functional α4β2 nAChR subtype would be constitutively expressed to play a role in the mechanism underlying the determination of proliferation and subsequent differentiation fate into a neuronal lineage in association with preferential promotion of Math1 expression in undifferentiated neural progenitors of developing rodent neocortex independently of NMDA receptor activation.

  13. Differentiation of Equine Mesenchymal Stromal Cells into Cells of Neural Lineage: Potential for Clinical Applications

    Directory of Open Access Journals (Sweden)

    Claudia Cruz Villagrán

    2014-01-01

    Full Text Available Mesenchymal stromal cells (MSCs are able to differentiate into extramesodermal lineages, including neurons. Positive outcomes were obtained after transplantation of neurally induced MSCs in laboratory animals after nerve injury, but this is unknown in horses. Our objectives were to test the ability of equine MSCs to differentiate into cells of neural lineage in vitro, to assess differences in morphology and lineage-specific protein expression, and to investigate if horse age and cell passage number affected the ability to achieve differentiation. Bone marrow-derived MSCs were obtained from young and adult horses. Following demonstration of stemness, MSCs were neurally induced and microscopically assessed at different time points. Results showed that commercially available nitrogen-coated tissue culture plates supported proliferation and differentiation. Morphological changes were immediate and all the cells displayed a neural crest-like cell phenotype. Expression of neural progenitor proteins, was assessed via western blot or immunofluorescence. In our study, MSCs generated from young and middle-aged horses did not show differences in their ability to undergo differentiation. The effect of cell passage number, however, is inconsistent and further experiments are needed. Ongoing work is aimed at transdifferentiating these cells into Schwann cells for transplantation into a peripheral nerve injury model in horses.

  14. Telomerase Protects Werner Syndrome Lineage-Specific Stem Cells from Premature Aging

    Directory of Open Access Journals (Sweden)

    Hoi-Hung Cheung

    2014-04-01

    Full Text Available Werner syndrome (WS patients exhibit premature aging predominantly in mesenchyme-derived tissues, but not in neural lineages, a consequence of telomere dysfunction and accelerated senescence. The cause of this lineage-specific aging remains unknown. Here, we document that reprogramming of WS fibroblasts to pluripotency elongated telomere length and prevented telomere dysfunction. To obtain mechanistic insight into the origin of tissue-specific aging, we differentiated iPSCs to mesenchymal stem cells (MSCs and neural stem/progenitor cells (NPCs. We observed recurrence of premature senescence associated with accelerated telomere attrition and defective synthesis of the lagging strand telomeres in MSCs, but not in NPCs. We postulate this “aging” discrepancy is regulated by telomerase. Expression of hTERT or p53 knockdown ameliorated the accelerated aging phenotypein MSC, whereas inhibition of telomerase sensitized NPCs to DNA damage. Our findings unveil a role for telomerase in the protection of accelerated aging in a specific lineage of stem cells.

  15. Progenitor cells in pulmonary vascular remodeling

    Science.gov (United States)

    Yeager, Michael E.; Frid, Maria G.; Stenmark, Kurt R.

    2011-01-01

    Pulmonary hypertension is characterized by cellular and structural changes in the walls of pulmonary arteries. Intimal thickening and fibrosis, medial hypertrophy and fibroproliferative changes in the adventitia are commonly observed, as is the extension of smooth muscle into the previously non-muscularized vessels. A majority of these changes are associated with the enhanced presence of α-SM-actin+ cells and inflammatory cells. Atypical abundances of functionally distinct endothelial cells, particularly in the intima (plexiform lesions), and also in the perivascular regions, are also described. At present, neither the origin(s) of these cells nor the molecular mechanisms responsible for their accumulation, in any of the three compartments of the vessel wall, have been fully elucidated. The possibility that they arise from either resident vascular progenitors or bone marrow–derived progenitor cells is now well established. Resident vascular progenitor cells have been demonstrated to exist within the vessel wall, and in response to certain stimuli, to expand and express myofibroblastic, endothelial or even hematopoietic markers. Bone marrow–derived or circulating progenitor cells have also been shown to be recruited to sites of vascular injury and to assume both endothelial and SM-like phenotypes. Here, we review the data supporting the contributory role of vascular progenitors (including endothelial progenitor cells, smooth muscle progenitor cells, pericytes, and fibrocytes) in vascular remodeling. A more complete understanding of the processes by which progenitor cells modulate pulmonary vascular remodeling will undoubtedly herald a renaissance of therapies extending beyond the control of vascular tonicity and reduction of pulmonary artery pressure. PMID:22034593

  16. State commitment to public participation

    International Nuclear Information System (INIS)

    Baranski, S.C.; Serie, P.J.

    1989-01-01

    This paper discusses how New York's approach to developing a new low-level radioactive waste disposal facility demonstrates a commitment to responsibility for waste generated within its borders. There is a strong, legislated commitment to meeting federal milestones and starting from scratch to select a suitable site and disposal method. Equally strong is the state's commitment to meaningful public participation. A statewide program is underway, including public information and education and interactive techniques. The public participation program is fully integrated with the technical and policy activities of the New York State Low-Level Radioactive Waste Siting Commission at all levels. The program is designed to progressively tailor techniques and coverage to the steps in site and method selection, and will focus most intensively on the communities where four sites are selected for full characterization

  17. Notch signaling and progenitor/ductular reaction in steatohepatitis.

    Directory of Open Access Journals (Sweden)

    Carola M Morell

    Full Text Available Persistent hepatic progenitor cells (HPC activation resulting in ductular reaction (DR is responsible for pathologic liver repair in cholangiopathies. Also, HPC/DR expansion correlates with fibrosis in several chronic liver diseases, including steatohepatitis. Increasing evidence indicates Notch signaling as a key regulator of HPC/DR response in biliary and more in general liver injuries. Therefore, we aimed to investigate the role of Notch during HPC/DR activation in a mouse model of steatohepatitis.Steatohepatitis was generated using methionine-choline deficient (MCD diet. For hepatocyte lineage tracing, R26R-YFP mice were infected with AAV8-TBG-Cre.MCD diet promoted a strong HPC/DR response that progressively diffused in the lobule, and correlated with increased fibrosis and TGF-β1 expression. Notch signaling was unchanged in laser-capture microdissected HPC/DR, whereas Notch receptors were down regulated in hepatocytes. However, in-vivo lineage tracing experiments identified discrete hepatocytes showing Notch-1 activation and expressing (the Notch-dependent Sox9. Stimulation of AML-12 hepatocyte-cell line with immobilized Jag1 induced Sox9 and down-regulated albumin and BSEP expression. TGF-β1 treatment in primary hepatic stellate cells (HSC induced Jag1 expression. In MCD diet-fed mice, αSMA-positive HSC were localized around Sox9 expressing hepatocytes, suggesting that Notch activation in hepatocytes was promoted by TGF-β1 stimulated HSC. In-vivo Notch inhibition reduced HPC response and fibrosis progression.Our data suggest that Notch signaling is an important regulator of DR and that in steatohepatitis, hepatocytes exposed to Jag1-positive HSC, contribute to pathologic DR by undergoing Notch-mediated differentiation towards an HPC-like phenotype. Given the roles of Notch in fibrosis and liver cancer, these data suggest mesenchymal expression of Jag1 as an alternative therapeutic target.

  18. Marketing service relationships: the role of commitment

    NARCIS (Netherlands)

    Wetzels, M.G.M.; Ruyter, de J.C.; Birgelen, van M.

    1998-01-01

    As with all relationships, it is commonly agreed on that partners in business must have a high degree of commitment towards their relationship. If commitment is lacking, the relationship will soon come to an end. Affective commitment, that is commitment based on attraction between partners, is to be

  19. Pledges of Commitment and Cooperation in Partnerships

    Directory of Open Access Journals (Sweden)

    Lachlan Deer

    2016-01-01

    Full Text Available We use experimental methods to investigate whether pledges of commitment can improve cooperation in endogenously-formed partnerships facing a social dilemma. Treatments vary in terms of the individual’s: (1 opportunity to commit to their partner; (2 the cost of dissolving committed partnerships; and (3 the distribution of these dissolution costs between partners. Our findings show that pledges of commitment alone can increase cooperation and welfare in committed partnerships. The introduction of relatively large and equally split costs yields similar gains. In contrast, when costs to dissolve committed partnerships fall solely on the individual choosing to break up, pledges of commitment fail to improve cooperation and welfare.

  20. Effects of Substrate and Co-Culture on Neural Progenitor Cell Differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Erin Boote [Iowa State Univ., Ames, IA (United States)

    2008-01-01

    In recent years the study of stem and progenitor cells has moved to the forefront of research. Since the isolation of human hematopoietic stem cells in 1988 and the subsequent discovery of a self renewing population of multipotent cells in many tissues, many researchers have envisioned a better understanding of development and potential clinical usage in intractable diseases. Both these goals, however, depend on a solid understanding of the intracellular and extracellular forces that cause stem cells to differentiate to a specific cell fate. Many diseases of large scale cell loss have been suggested as candidates for stem cell based treatments. It is proposed that replacing the function of the damaged or defective cells by specific differentiation of stem or progenitor cells could treat the disease. Before cells can be directed to specific lineages, the mechanisms of differentiation must be better understood. Differentiation in vivo is an intensively complex system that is difficult to study. The goal of this research is to develop further understanding of the effects of soluble and extracellular matrix (ECM) cues on the differentiation of neural progenitor cells with the use of a simplified in vitro culture system. Specific research objectives are to study the differentiation of neural progenitor cells in response to astrocyte conditioned medium and protein substrate composition and concentration. In an effort to reveal the mechanism of the conditioned medium interaction, a test for the presence of a feedback loop between progenitor cells and astrocytes is presented along with an examination of conditioned medium storage temperature, which can reveal enzymatic dependencies. An examination of protein substrate composition and concentration will help to reveal the role of any ECM interactions on differentiation. This thesis is organized into a literature review covering recent advances in use of external modulators of differentiation such as surface coatings, co

  1. Constitutive expression of pluripotency-associated genes in mesodermal progenitor cells (MPCs.

    Directory of Open Access Journals (Sweden)

    Simone Pacini

    Full Text Available BACKGROUND: We recently characterized a progenitor of mesodermal lineage (MPCs from the human bone marrow of adults or umbilical cord blood. These cells are progenitors able to differentiate toward mesenchymal, endothelial and cardiomyogenic lineages. Here we present an extensive molecular characterization of MPCs, from bone marrow samples, including 39 genes involved in stem cell machinery, differentiation and cell cycle regulation. METHODOLOGY/PRINCIPAL FINDINGS: MPCs are cytofluorimetrically characterized and quantitative RT-PCR was performed to evaluate the gene expression profile, comparing it with MSCs and hESCs lines. Immunofluorescence and dot-blot analysis confirm qRT-PCR data. MPCs exhibit an increased expression of OCT4, NANOG, SALL4, FBX15, SPP1 and to a lesser extent c-MYC and KLF4, but lack LIN28 and SOX2. MPCs highly express SOX15. CONCLUSIONS/SIGNIFICANCE: MPCs express many pluripotency-associated genes and show a peculiar Oct-4 molecular circuit. Understanding this unique molecular mechanism could lead to identifying MPCs as feasible, long telomeres, target cells for reprogramming with no up-regulation of the p53 pathway. Furthermore MPCs are easily and inexpensively harvested from human bone marrow.

  2. Distinct roles of neuroepithelial-like and radial glia-like progenitor cells in cerebellar regeneration.

    Science.gov (United States)

    Kaslin, Jan; Kroehne, Volker; Ganz, Julia; Hans, Stefan; Brand, Michael

    2017-04-15

    Zebrafish can regenerate after brain injury, and the regenerative process is driven by resident stem cells. Stem cells are heterogeneous in the vertebrate brain, but the significance of having heterogeneous stem cells in regeneration is not understood. Limited availability of specific stem cells might impair the regeneration of particular cell lineages. We studied regeneration of the adult zebrafish cerebellum, which contains two major stem and progenitor cell types: ventricular zone and neuroepithelial cells. Using conditional lineage tracing we demonstrate that cerebellar regeneration depends on the availability of specific stem cells. Radial glia-like cells are thought to be the predominant stem cell type in homeostasis and after injury. However, we find that radial glia-like cells play a minor role in adult cerebellar neurogenesis and in recovery after injury. Instead, we find that neuroepithelial cells are the predominant stem cell type supporting cerebellar regeneration after injury. Zebrafish are able to regenerate many, but not all, cell types in the cerebellum, which emphasizes the need to understand the contribution of different adult neural stem and progenitor cell subtypes in the vertebrate central nervous system. © 2017. Published by The Company of Biologists Ltd.

  3. Pledges of commitment and cooperation in partnerships

    OpenAIRE

    Lachlan Deer; Ralph-C. Bayer

    2015-01-01

    We use experimental methods to investigate whether pledges of commitment can improve cooperation in endogenously-formed partnerships facing a social dilemma. Treatments vary in terms of the individual's: (1) opportunity to commit to their partner; (2) the cost of dissolving committed partnerships; and (3) the distribution of these dissolution costs between partners. Our findings show that pledges of commitment alone can increase cooperation and welfare in committed partnerships. The introduct...

  4. Determining Lineage Pathways from Cellular Barcoding Experiments

    Directory of Open Access Journals (Sweden)

    Leïla Perié

    2014-02-01

    Full Text Available Cellular barcoding and other single-cell lineage-tracing strategies form experimental methodologies for analysis of in vivo cell fate that have been instrumental in several significant recent discoveries. Due to the highly nonlinear nature of proliferation and differentiation, interrogation of the resulting data for evaluation of potential lineage pathways requires a new quantitative framework complete with appropriate statistical tests. Here, we develop such a framework, illustrating its utility by analyzing data from barcoded multipotent cells of the blood system. This application demonstrates that the data require additional paths beyond those found in the classical model, which leads us to propose that hematopoietic differentiation follows a loss of potential mechanism and to suggest further experiments to test this deduction. Our quantitative framework can evaluate the compatibility of lineage trees with barcoded data from any proliferating and differentiating cell system.

  5. Human induced pluripotent stem cells differentiation into oligodendrocyte progenitors and transplantation in a rat model of optic chiasm demyelination.

    Directory of Open Access Journals (Sweden)

    Alireza Pouya

    Full Text Available BACKGROUND: This study aims to differentiate human induced pluripotent stem cells (hiPSCs into oligodendrocyte precursors and assess their recovery potential in a demyelinated optic chiasm model in rats. METHODOLOGY/PRINCIPAL FINDINGS: We generated a cell population of oligodendrocyte progenitors from hiPSCs by using embryoid body formation in a defined medium supplemented with a combination of factors, positive selection and mechanical enrichment. Real-time polymerase chain reaction and immunofluorescence analyses showed that stage-specific markers, Olig2, Sox10, NG2, PDGFRα, O4, A2B5, GalC, and MBP were expressed following the differentiation procedure, and enrichment of the oligodendrocyte lineage. These results are comparable with the expression of stage-specific markers in human embryonic stem cell-derived oligodendrocyte lineage cells. Transplantation of hiPSC-derived oligodendrocyte progenitors into the lysolecithin-induced demyelinated optic chiasm of the rat model resulted in recovery from symptoms, and integration and differentiation into oligodendrocytes were detected by immunohistofluorescence staining against PLP and MBP, and measurements of the visual evoked potentials. CONCLUSIONS/SIGNIFICANCE: These results showed that oligodendrocyte progenitors generated efficiently from hiPSCs can be used in future biomedical studies once safety issues have been overcome.

  6. Pluripotent cell models of fanconi anemia identify the early pathological defect in human hemoangiogenic progenitors.

    Science.gov (United States)

    Suzuki, Naoya M; Niwa, Akira; Yabe, Miharu; Hira, Asuka; Okada, Chihiro; Amano, Naoki; Watanabe, Akira; Watanabe, Ken-Ichiro; Heike, Toshio; Takata, Minoru; Nakahata, Tatsutoshi; Saito, Megumu K

    2015-04-01

    Fanconi anemia (FA) is a disorder of genomic instability characterized by progressive bone marrow failure (BMF), developmental abnormalities, and an increased susceptibility to cancer. Although various consequences in hematopoietic stem/progenitor cells have been attributed to FA-BMF, the quest to identify the initial pathological event is still ongoing. To address this issue, we established induced pluripotent stem cells (iPSCs) from fibroblasts of six patients with FA and FANCA mutations. An improved reprogramming method yielded iPSC-like colonies from all patients, and iPSC clones were propagated from two patients. Quantitative evaluation of the differentiation ability demonstrated that the differentiation propensity toward the hematopoietic and endothelial lineages is already defective in early hemoangiogenic progenitors. The expression levels of critical transcription factors were significantly downregulated in these progenitors. These data indicate that the hematopoietic consequences in FA patients originate from the early hematopoietic stage and highlight the potential usefulness of iPSC technology for elucidating the pathogenesis of FA-BMF. ©AlphaMed Press.

  7. Generation of Oligodendrogenic Spinal Neural Progenitor Cells From Human Induced Pluripotent Stem Cells.

    Science.gov (United States)

    Khazaei, Mohamad; Ahuja, Christopher S; Fehlings, Michael G

    2017-08-14

    This unit describes protocols for the efficient generation of oligodendrogenic neural progenitor cells (o-NPCs) from human induced pluripotent stem cells (hiPSCs). Specifically, detailed methods are provided for the maintenance and differentiation of hiPSCs, human induced pluripotent stem cell-derived neural progenitor cells (hiPS-NPCs), and human induced pluripotent stem cell-oligodendrogenic neural progenitor cells (hiPSC-o-NPCs) with the final products being suitable for in vitro experimentation or in vivo transplantation. Throughout, cell exposure to growth factors and patterning morphogens has been optimized for both concentration and timing, based on the literature and empirical experience, resulting in a robust and highly efficient protocol. Using this derivation procedure, it is possible to obtain millions of oligodendrogenic-NPCs within 40 days of initial cell plating which is substantially shorter than other protocols for similar cell types. This protocol has also been optimized to use translationally relevant human iPSCs as the parent cell line. The resultant cells have been extensively characterized both in vitro and in vivo and express key markers of an oligodendrogenic lineage. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley and Sons, Inc.

  8. Clonal proliferation of multipotent stem/progenitor cells in the neonatal and adult salivary glands

    International Nuclear Information System (INIS)

    Kishi, Teruki; Takao, Tukasa; Fujita, Kiyohide; Taniguchi, Hideki

    2006-01-01

    Salivary gland stem/progenitor cells are thought to be present in intercalated ductal cells, but the fact is unclear. In this study, we sought to clarify if stem/progenitor cells are present in submandibular glands using colony assay, which is one of the stem cell assay methods. Using a low-density culture of submandibular gland cells of neonatal rats, we developed a novel culture system that promotes single cell colony formation. Average doubling time for the colony-forming cells was 24.7 (SD = ±7.02) h, indicating high proliferative potency. When epidermal growth factor (EGF) and hepatocyte growth factor (HGF) were added to the medium, the number of clonal colonies increased greater than those cultured without growth factors (13.2 ± 4.18 vs. 4.5 ± 1.73). The RT-PCR and immunostaining demonstrated expressing acinar, ductal, and myoepithelial cell lineage markers. This study demonstrated the presence of the salivary gland stem/progenitor cells that are highly proliferative and multipotent in salivary glands

  9. Fibronectin promotes differentiation of neural crest progenitors endowed with smooth muscle cell potential

    International Nuclear Information System (INIS)

    Costa-Silva, Bruno; Coelho da Costa, Meline; Melo, Fernanda Rosene; Neves, Cynara Mendes; Alvarez-Silva, Marcio; Calloni, Giordano Wosgrau; Trentin, Andrea Goncalves

    2009-01-01

    The neural crest (NC) is a model system used to investigate multipotency during vertebrate development. Environmental factors control NC cell fate decisions. Despite the well-known influence of extracellular matrix molecules in NC cell migration, the issue of whether they also influence NC cell differentiation has not been addressed at the single cell level. By analyzing mass and clonal cultures of mouse cephalic and quail trunk NC cells, we show for the first time that fibronectin (FN) promotes differentiation into the smooth muscle cell phenotype without affecting differentiation into glia, neurons, and melanocytes. Time course analysis indicated that the FN-induced effect was not related to massive cell death or proliferation of smooth muscle cells. Finally, by comparing clonal cultures of quail trunk NC cells grown on FN and collagen type IV (CLIV), we found that FN strongly increased both NC cell survival and the proportion of unipotent and oligopotent NC progenitors endowed with smooth muscle potential. In contrast, melanocytic progenitors were prominent in clonogenic NC cells grown on CLIV. Taken together, these results show that FN promotes NC cell differentiation along the smooth muscle lineage, and therefore plays an important role in fate decisions of NC progenitor cells

  10. β-Cell regeneration through the transdifferentiation of pancreatic cells: Pancreatic progenitor cells in the pancreas.

    Science.gov (United States)

    Kim, Hyo-Sup; Lee, Moon-Kyu

    2016-05-01

    Pancreatic progenitor cell research has been in the spotlight, as these cells have the potential to replace pancreatic β-cells for the treatment of type 1 and 2 diabetic patients with the absence or reduction of pancreatic β-cells. During the past few decades, the successful treatment of diabetes through transplantation of the whole pancreas or isolated islets has nearly been achieved. However, novel sources of pancreatic islets or insulin-producing cells are required to provide sufficient amounts of donor tissues. To overcome this limitation, the use of pancreatic progenitor cells is gaining more attention. In particular, pancreatic exocrine cells, such as duct epithelial cells and acinar cells, are attractive candidates for β-cell regeneration because of their differentiation potential and pancreatic lineage characteristics. It has been assumed that β-cell neogenesis from pancreatic progenitor cells could occur in pancreatic ducts in the postnatal stage. Several studies have shown that insulin-producing cells can arise in the duct tissue of the adult pancreas. Acinar cells also might have the potential to differentiate into insulin-producing cells. The present review summarizes recent progress in research on the transdifferentiation of pancreatic exocrine cells into insulin-producing cells, especially duct and acinar cells.

  11. Enteric nervous system specific deletion of Foxd3 disrupts glial cell differentiation and activates compensatory enteric progenitors.

    Science.gov (United States)

    Mundell, Nathan A; Plank, Jennifer L; LeGrone, Alison W; Frist, Audrey Y; Zhu, Lei; Shin, Myung K; Southard-Smith, E Michelle; Labosky, Patricia A

    2012-03-15

    The enteric nervous system (ENS) arises from the coordinated migration, expansion and differentiation of vagal and sacral neural crest progenitor cells. During development, vagal neural crest cells enter the foregut and migrate in a rostro-to-caudal direction, colonizing the entire gastrointestinal tract and generating the majority of the ENS. Sacral neural crest contributes to a subset of enteric ganglia in the hindgut, colonizing the colon in a caudal-to-rostral wave. During this process, enteric neural crest-derived progenitors (ENPs) self-renew and begin expressing markers of neural and glial lineages as they populate the intestine. Our earlier work demonstrated that the transcription factor Foxd3 is required early in neural crest-derived progenitors for self-renewal, multipotency and establishment of multiple neural crest-derived cells and structures including the ENS. Here, we describe Foxd3 expression within the fetal and postnatal intestine: Foxd3 was strongly expressed in ENPs as they colonize the gastrointestinal tract and was progressively restricted to enteric glial cells. Using a novel Ednrb-iCre transgene to delete Foxd3 after vagal neural crest cells migrate into the midgut, we demonstrated a late temporal requirement for Foxd3 during ENS development. Lineage labeling of Ednrb-iCre expressing cells in Foxd3 mutant embryos revealed a reduction of ENPs throughout the gut and loss of Ednrb-iCre lineage cells in the distal colon. Although mutant mice were viable, defects in patterning and distribution of ENPs were associated with reduced proliferation and severe reduction of glial cells derived from the Ednrb-iCre lineage. Analyses of ENS-lineage and differentiation in mutant embryos suggested activation of a compensatory population of Foxd3-positive ENPs that did not express the Ednrb-iCre transgene. Our findings highlight the crucial roles played by Foxd3 during ENS development including progenitor proliferation, neural patterning, and glial

  12. Quality Improvement with Trustee Commitment.

    Science.gov (United States)

    Chaffee, Ellen Earle; Seymour, Daniel

    1991-01-01

    Total Quality Management is a comprehensive system for developing organizationwide participation in planning for and implementing continuous improvement in critical processes. In colleges, trustees can be central to the success of the method through their commitment and the development of supportive policy and procedures. (MSE)

  13. Commitment Profiles and Employee Turnover

    Science.gov (United States)

    Stanley, Laura; Vandenberghe, Christian; Vandenberg, Robert; Bentein, Kathleen

    2013-01-01

    We examined how affective (AC), normative (NC), perceived sacrifice (PS), and few alternatives (FA) commitments combine to form profiles and determine turnover intention and turnover. We theorized that three mechanisms account for how profiles operate, i.e., the degree to which membership is internally regulated, the perceived desirability and…

  14. When a Patient Commits Suicide.

    Science.gov (United States)

    Marshall, Karol A.

    1980-01-01

    Suicide is a tragic and upsetting event which sometimes occurs when a person is in some form of therapy. This paper advocates a process after a patient commits suicide which allows for a thorough and orderly working through of the event by involved treatment personnel. (Author)

  15. Cheat Sensitive Quantum Bit Commitment

    OpenAIRE

    Hardy, Lucien; Kent, Adrian

    1999-01-01

    We define cheat sensitive cryptographic protocols between mistrustful parties as protocols which guarantee that, if either cheats, the other has some nonzero probability of detecting the cheating. We give an example of an unconditionally secure cheat sensitive non-relativistic bit commitment protocol which uses quantum information to implement a task which is classically impossible; we also describe a simple relativistic protocol.

  16. Cheat sensitive quantum bit commitment.

    Science.gov (United States)

    Hardy, Lucien; Kent, Adrian

    2004-04-16

    We define cheat sensitive cryptographic protocols between mistrustful parties as protocols which guarantee that, if either cheats, the other has some nonzero probability of detecting the cheating. We describe an unconditionally secure cheat sensitive nonrelativistic bit commitment protocol which uses quantum information to implement a task which is classically impossible; we also describe a simple relativistic protocol.

  17. Parenting--Challenge and Commitment

    Science.gov (United States)

    Luckey, Eleanore Braun

    1973-01-01

    This is a revised version of the National Council on Family Relations Presidential address delivered November 3, 1972, Portland Oregon. This address concerned the new constitution and reorganization of N.C.F.R. and a plea for reexamination of the membership's commitment to family issues. (JC)

  18. Idiosyncratic Deals and Organizational Commitment

    Science.gov (United States)

    Ng, Thomas W. H.; Feldman, Daniel C.

    2010-01-01

    This article examines the relationship between idiosyncratic deals and organizational commitment. In particular, it examines how two individual differences which reflect self-worth (core self-evaluations and age) moderate that relationship. We predicted that employees with feelings of high self-worth will expect and will feel entitled to these…

  19. Physical Education Teachers' Organizational Commitment

    Science.gov (United States)

    Demir, Hayri

    2013-01-01

    The aim of this study was to determine physical education teachers' organizational commitment levels. The sample consisted of 204 physical education teachers working in the city center of Konya in the 2011 to 2012 academic year. The respondents were randomly selected in this research. Data collected for this research by using the Scale for…

  20. Faculty Organizational Commitment and Citizenship

    Science.gov (United States)

    Lawrence, Janet; Ott, Molly; Bell, Alli

    2012-01-01

    Building on a theoretical framework that links characteristics of individuals and their work settings to organizational commitment (OC) and citizenship behavior, this study considers why faculty may be disengaging from institutional service. Analyses of survey data collected from a state system of higher education suggest that job characteristics,…

  1. 24-Hour Relativistic Bit Commitment.

    Science.gov (United States)

    Verbanis, Ephanielle; Martin, Anthony; Houlmann, Raphaël; Boso, Gianluca; Bussières, Félix; Zbinden, Hugo

    2016-09-30

    Bit commitment is a fundamental cryptographic primitive in which a party wishes to commit a secret bit to another party. Perfect security between mistrustful parties is unfortunately impossible to achieve through the asynchronous exchange of classical and quantum messages. Perfect security can nonetheless be achieved if each party splits into two agents exchanging classical information at times and locations satisfying strict relativistic constraints. A relativistic multiround protocol to achieve this was previously proposed and used to implement a 2-millisecond commitment time. Much longer durations were initially thought to be insecure, but recent theoretical progress showed that this is not so. In this Letter, we report on the implementation of a 24-hour bit commitment solely based on timed high-speed optical communication and fast data processing, with all agents located within the city of Geneva. This duration is more than 6 orders of magnitude longer than before, and we argue that it could be extended to one year and allow much more flexibility on the locations of the agents. Our implementation offers a practical and viable solution for use in applications such as digital signatures, secure voting and honesty-preserving auctions.

  2. Foetal stem cell derivation & characterization for osteogenic lineage

    Directory of Open Access Journals (Sweden)

    A Mangala Gowri

    2013-01-01

    Full Text Available Background & objectives: Mesencymal stem cells (MSCs derived from foetal tissues present a multipotent progenitor cell source for application in tissue engineering and regenerative medicine. The present study was carried out to derive foetal mesenchymal stem cells from ovine source and analyze their differentiation to osteogenic linage to serve as an animal model to predict human applications. Methods: Isolation and culture of sheep foetal bone marrow cells were done and uniform clonally derived MSC population was collected. The cells were characterized using cytochemical, immunophenotyping, biochemical and molecular analyses. The cells with defined characteristics were differentiated into osteogenic lineages and analysis for differentiated cell types was done. The cells were analyzed for cell surface marker expression and the gene expression in undifferentiated and differentiated osteoblast was checked by reverse transcriptase PCR (RT PCR analysis and confirmed by sequencing using genetic analyzer. Results: Ovine foetal samples were processed to obtain mononuclear (MNC cells which on culture showed spindle morphology, a characteristic oval body with the flattened ends. MSC population CD45 - /CD14 - was cultured by limiting dilution to arrive at uniform spindle morphology cells and colony forming units. The cells were shown to be positive for surface markers such as CD44, CD54, integrinβ1, and intracellular collagen type I/III and fibronectin. The osteogenically induced MSCs were analyzed for alkaline phosphatase (ALP activity and mineral deposition. The undifferentiated MSCs expressed RAB3B, candidate marker for stemness in MSCs. The osteogenically induced and uninduced MSCs expressed collagen type I and MMP13 gene in osteogenic induced cells. Interpretation & conclusions: The protocol for isolation of ovine foetal bone marrow derived MSCs was simple to perform, and the cultural method of obtaining pure spindle morphology cells was established

  3. Genetic manipulation of RPS5 gene expression modulates the initiation of commitment of MEL cells to erythroid maturation: Implications in understanding ribosomopathies.

    Science.gov (United States)

    Vizirianakis, Ioannis S; Papachristou, Eleni T; Andreadis, Panagiotis; Zopounidou, Elena; Matragkou, Christina N; Tsiftsoglou, Asterios S

    2015-07-01

    Impairment of ribosome biogenesis contributes to the molecular pathophysiology of ribosomopathies by deregulating cell-lineage specific proliferation, differentiation and apoptosis decisions of haematopoietic progenitor cells. Here, using pro-erythroblast-like murine erythroleukemia (MEL) cells, a model system of erythroid maturation, we aimed to investigate whether genetic manipulation of RPS5 expression affects the capacity of cells to grow and differentiate in culture. Parental MEL cells stably transfected with full length RPS5 cDNA in sense (MEL-C14 culture) or antisense (MEL-antisenseRPS5 culture) orientation, as well as MEL cells transiently transfected with siRNAs specific for RPS5 gene silencing (MEL-RPS5siRNA culture) were assessed for their ability to fully execute their erythroid maturation program in culture. The data obtained thus far indicate that: a) MEL-antisenseRPS5 exhibit a pronounced delay in the initiation of differentiation, as well as an impairment of commitment, since the continuous presence of the inducer in culture is required for the cells to fully execute their erythroid maturation program. b) RNAi-mediating silencing of RPS5 gene expression resulted in the inability of MEL cells to differentiate; however, when these cells were allowed to recapitulate normal RPS5 gene expression levels they regained their differentiation capacity by accumulating high proportion of erythroid mature cells. c) Interestingly the latter, is accompanied by morphological changes of cells and an impairment of their proliferation and apoptosis potential. Such data for the first time correlate the RPS5 gene expression levels with the differentiation capacity of MEL cells in vitro, a fact that might also have implications in understanding ribosomopathies.

  4. Disruption of Hox9,10,11 function results in cellular level lineage infidelity in the kidney.

    Science.gov (United States)

    Drake, Keri A; Adam, Mike; Mahoney, Robert; Potter, S Steven

    2018-04-20

    Hox genes are important regulators of development. The 39 mammalian Hox genes have considerable functional overlap, greatly confounding their study. In this report, we generated mice with multiple combinations of paralogous and flanking Abd-B Hox gene mutations to investigate functional redundancies in kidney development. The resulting mice developed a number of kidney abnormalities, including hypoplasia, agenesis, and severe cysts, with distinct Hox functions observed in early metanephric kidney formation and nephron progenitor maintenance. Most surprising, however, was that extensive removal of Hox shared function in these kidneys resulted in cellular level lineage infidelity. Strikingly, mutant nephron tubules consisted of intermixed cells with proximal tubule, loop of Henle, and collecting duct identities, with some single cells expressing markers associated with more than one nephron segment. These results indicate that Hox genes are required for proper lineage selection/maintenance and full repression of genes involved in cell fate restriction in the developing kidney.

  5. In vitro analysis of the oligodendrocyte lineage in mice during demyelination and remyelination

    International Nuclear Information System (INIS)

    Armstrong, R.; Friedrich, V.L. Jr.; Holmes, K.V.; Dubois-Dalcq, M.

    1990-01-01

    A demyelinating disease induced in C57B1/6N mice by intracranial injection of a coronavirus (murine hepatitis virus strain A59) is followed by functional recovery and efficient CNS myelin repair. To study the biological properties of the cells involved in this repair process, glial cells were isolated and cultured from spinal cords of these young adult mice during demyelination and remyelination. Using three-color immunofluorescence combined with [3H]thymidine autoradiography, we have analyzed the antigenic phenotype and mitotic potential of individual glial cells. We identified oligodendrocytes with an antibody to galactocerebroside, astrocytes with an antibody to glial fibrillary acidic protein, and oligodendrocyte-type 2 astrocyte (O-2A) progenitor cells with the O4 antibody. Cultures from demyelinated tissue differed in several ways from those of age-matched controls: first, the total number of O-2A lineage cells was strikingly increased; second, the O-2A population consisted of a higher proportion of O4-positive astrocytes and cells of mixed oligodendrocyte-astrocyte phenotype; and third, all the cell types within the O-2A lineage showed enhanced proliferation. This proliferation was not further enhanced by adding PDGF, basic fibroblast growth factor (bFGF), or insulin-like growth factor I (IGF-I) to the defined medium. However, bFGF and IGF-I seemed to influence the fate of O-2A lineage cells in cultures of demyelinated tissue. Basic FGF decreased the percentage of cells expressing galactocerebroside. In contrast, IGF-I increased the relative proportion of oligodendrocytes. Thus, O-2A lineage cells from adult mice display greater phenotypic plasticity and enhanced mitotic potential in response to an episode of demyelination. These properties may be linked to the efficient remyelination achieved in this demyelinating disease

  6. Regulation of Prostate Development and Benign Prostatic Hyperplasia by Autocrine Cholinergic Signaling via Maintaining the Epithelial Progenitor Cells in Proliferating Status

    Directory of Open Access Journals (Sweden)

    Naitao Wang

    2016-05-01

    Full Text Available Regulation of prostate epithelial progenitor cells is important in prostate development and prostate diseases. Our previous study demonstrated a function of autocrine cholinergic signaling (ACS in promoting prostate cancer growth and castration resistance. However, whether or not such ACS also plays a role in prostate development is unknown. Here, we report that ACS promoted the proliferation and inhibited the differentiation of prostate epithelial progenitor cells in organotypic cultures. These results were confirmed by ex vivo lineage tracing assays and in vivo renal capsule recombination assays. Moreover, we found that M3 cholinergic receptor (CHRM3 was upregulated in a large subset of benign prostatic hyperplasia (BPH tissues compared with normal tissues. Activation of CHRM3 also promoted the proliferation of BPH cells. Together, our findings identify a role of ACS in maintaining prostate epithelial progenitor cells in the proliferating state, and blockade of ACS may have clinical implications for the management of BPH.

  7. Stem Cell Lineages: Between Cell and Organism

    Directory of Open Access Journals (Sweden)

    Melinda Bonnie Fagan

    2017-01-01

    Full Text Available Ontologies of living things are increasingly grounded on the concepts and practices of current life science. Biological development is a process, undergone by living things, which begins with a single cell and (in an important class of cases ends with formation of a multicellular organism. The process of development is thus prima facie central for ideas about biological individuality and organismality. However, recent accounts of these concepts do not engage developmental biology. This paper aims to fill the gap, proposing the lineage view of stem cells as an ontological framework for conceptualizing organismal development. This account is grounded on experimental practices of stem cell research, with emphasis on new techniques for generating biological organization in vitro. On the lineage view, a stem cell is the starting point of a cell lineage with a specific organismal source, time-interval of existence, and ‘tree topology’ of branch-points linking the stem to developmental termini. The concept of ‘enkapsis’ accommodates the cell-organism relation within the lineage view; this hierarchical notion is further explicated by considering the methods and results of stem cell experiments. Results of this examination include a (partial characterization of stem cells’ developmental versatility, and the context-dependence of developmental processes involving stem cells.

  8. Diversity rankings among bacterial lineages in soil.

    Science.gov (United States)

    Youssef, Noha H; Elshahed, Mostafa S

    2009-03-01

    We used rarefaction curve analysis and diversity ordering-based approaches to rank the 11 most frequently encountered bacterial lineages in soil according to diversity in 5 previously reported 16S rRNA gene clone libraries derived from agricultural, undisturbed tall grass prairie and forest soils (n=26,140, 28 328, 31 818, 13 001 and 53 533). The Planctomycetes, Firmicutes and the delta-Proteobacteria were consistently ranked among the most diverse lineages in all data sets, whereas the Verrucomicrobia, Gemmatimonadetes and beta-Proteobacteria were consistently ranked among the least diverse. On the other hand, the rankings of alpha-Proteobacteria, Acidobacteria, Actinobacteria, Bacteroidetes and Chloroflexi varied widely in different soil clone libraries. In general, lineages exhibiting largest differences in diversity rankings also exhibited the largest difference in relative abundance in the data sets examined. Within these lineages, a positive correlation between relative abundance and diversity was observed within the Acidobacteria, Actinobacteria and Chloroflexi, and a negative diversity-abundance correlation was observed within the Bacteroidetes. The ecological and evolutionary implications of these results are discussed.

  9. Heterogeneity of limbal basal epithelial progenitor cells.

    Science.gov (United States)

    Hayashida, Yasutaka; Li, Wei; Chen, Ying-Ting; He, Hua; Chen, Szu-yu; Kheirkah, Ahmad; Zhu, Ying-Tien; Matsumoto, Yukihiro; Tseng, Scheffer C G

    2010-11-01

    Although corneal epithelial stem cells (SCs) are located at the limbus between the cornea and the conjunctiva, not all limbal basal epithelial cells are SCs. Using 2 dispase digestions to remove different amounts of limbal basal epithelial cells for cross-sections, flat mounts, and cytospin preparations, double immunostaining to pancytokeratins (PCK) and vimentin (Vim) identified 3 p63+ epithelial progenitors such as PCK-/Vim+, PCK/Vim, and PCK-/Vim+ and 1 p63+ mesenchymal cell, PCK-/Vim+. PCK-/Vim- progenitors had the smallest cell size were 10-20 times more enriched on collagen I-coated dishes in the 5-minute rapid adherent fraction that contained the highest percentage of p63+ cells but the lowest percentage of cytokeratin12+ cells, and gave rise to high Ki67 labeling and vivid clonal growth. In contrast, PCK+/Vim+ and PCK+/Vim- progenitors were found more in the slow-adherent fraction and yielded poor clonal growth. PCK/Vim progenitors and clusters of PCK-/Vim+ mesenchymal cells, which were neither melanocytes nor Langerhans cells, were located in the limbal basal region. Therefore, differential expression of PCK and Vim helps identify small PCK-/Vim- cells as the most likely candidate for SCs among a hierarchy of heterogeneous limbal basal progenitors, and their close association with PCK-/Vim+ presumed "niche" cells.

  10. Effects of extracellular matrix proteins on the growth of haematopoietic progenitor cells

    International Nuclear Information System (INIS)

    Celebi, Betuel; Pineault, Nicolas; Mantovani, Diego

    2011-01-01

    Umbilical cord blood (UCB) transplantation and haematological recovery are currently limited by the amount of haematopoietic progenitor cells (HPCs) present in each unit. HPCs and haematopoietic stem cells (HSCs) normally interact with cells and extracellular matrix (ECM) proteins present within the endosteal and vascular niches. Hence, we investigated whether coating of culture surfaces with ECM proteins normally present in the marrow microenvironment could benefit the ex vivo expansion of HPCs. Towards this, collagen types I and IV (COL I and IV), laminin (LN) and fibronectin (FN) were tested individually or as component of two ECM-mix complexes. Individually, ECM proteins had both common and unique properties on the growth and differentiation of UCB CD34+ cells; some ECM proteins favoured the differentiation of some lineages over that of others (e.g. FN for erythroids), some the expansion of HPCs (e.g. LN and megakaryocyte (MK) progenitor) while others had less effects. Next, two ECM-mix complexes were tested; the first one contained all four ECM proteins (4ECMp), while the second 'basement membrane-like structure' was without COL I (3ECMp). Removal of COL I led to strong reductions in cell growth and HPCs expansion. Interestingly, the 4ECMp-mix complex reproducibly increased CD34+ (1.3-fold) and CD41+ (1.2-fold) cell expansions at day 6 (P < 0.05) versus control, and induced greater myeloid progenitor expansion (P < 0.05) than 3ECMp. In conclusion, these results suggest that optimization of BM ECM protein complexes could provide a better environment for the ex vivo expansion of haematopoietic progenitors than individual ECM protein.

  11. Effects of extracellular matrix proteins on the growth of haematopoietic progenitor cells

    Energy Technology Data Exchange (ETDEWEB)

    Celebi, Betuel; Pineault, Nicolas [Hema-Quebec, Research and Development Department, Quebec City, G1V 5C3, PQ (Canada); Mantovani, Diego, E-mail: nicolas.pineault@hema-quebec.qc.ca [Laboratory for Biomaterials and Bioengineering, Department of Materials Engineering and University Hospital Research Center, Laval University, Quebec City, G1V 0A6, PQ (Canada)

    2011-10-15

    Umbilical cord blood (UCB) transplantation and haematological recovery are currently limited by the amount of haematopoietic progenitor cells (HPCs) present in each unit. HPCs and haematopoietic stem cells (HSCs) normally interact with cells and extracellular matrix (ECM) proteins present within the endosteal and vascular niches. Hence, we investigated whether coating of culture surfaces with ECM proteins normally present in the marrow microenvironment could benefit the ex vivo expansion of HPCs. Towards this, collagen types I and IV (COL I and IV), laminin (LN) and fibronectin (FN) were tested individually or as component of two ECM-mix complexes. Individually, ECM proteins had both common and unique properties on the growth and differentiation of UCB CD34+ cells; some ECM proteins favoured the differentiation of some lineages over that of others (e.g. FN for erythroids), some the expansion of HPCs (e.g. LN and megakaryocyte (MK) progenitor) while others had less effects. Next, two ECM-mix complexes were tested; the first one contained all four ECM proteins (4ECMp), while the second 'basement membrane-like structure' was without COL I (3ECMp). Removal of COL I led to strong reductions in cell growth and HPCs expansion. Interestingly, the 4ECMp-mix complex reproducibly increased CD34+ (1.3-fold) and CD41+ (1.2-fold) cell expansions at day 6 (P < 0.05) versus control, and induced greater myeloid progenitor expansion (P < 0.05) than 3ECMp. In conclusion, these results suggest that optimization of BM ECM protein complexes could provide a better environment for the ex vivo expansion of haematopoietic progenitors than individual ECM protein.

  12. Replacement of Lost Lgr5-Positive Stem Cells through Plasticity of Their Enterocyte-Lineage Daughters.

    Science.gov (United States)

    Tetteh, Paul W; Basak, Onur; Farin, Henner F; Wiebrands, Kay; Kretzschmar, Kai; Begthel, Harry; van den Born, Maaike; Korving, Jeroen; de Sauvage, Frederic; van Es, Johan H; van Oudenaarden, Alexander; Clevers, Hans

    2016-02-04

    Intestinal crypts display robust regeneration upon injury. The relatively rare secretory precursors can replace lost stem cells, but it is unknown if the abundant enterocyte progenitors that express the Alkaline phosphate intestinal (Alpi) gene also have this capacity. We created an Alpi-IRES-CreERT2 (Alpi(CreER)) knockin allele for lineage tracing. Marked clones consist entirely of enterocytes and are all lost from villus tips within days. Genetic fate-mapping of Alpi(+) cells before or during targeted ablation of Lgr5-expressing stem cells generated numerous long-lived crypt-villus "ribbons," indicative of dedifferentiation of enterocyte precursors into Lgr5(+) stems. By single-cell analysis of dedifferentiating enterocytes, we observed the generation of Paneth-like cells and proliferative stem cells. We conclude that the highly proliferative, short-lived enterocyte precursors serve as a large reservoir of potential stem cells during crypt regeneration. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Boards: Independent and Committed Directors?

    OpenAIRE

    Christophe Volonté

    2011-01-01

    Regulators, proxy advisors and shareholders are regularly calling for independent directors. However, at the same time, independent directors commonly engage in numerous outside activities potentially reducing their time and commitment with the particular firm. Using Tobin's Q as an approximation of market valuation and controlling for endogeneity, our empirical analysis reveals that neither is independence positively related to firm performance nor are outside activities negatively related t...

  14. Haemopoietic progenitor cells in human peripheral blood

    International Nuclear Information System (INIS)

    Zwaan, F.E.

    1980-01-01

    The purpose of the investigation reported is to purify haemopoietic progenitor cells from human peripheral blood using density gradient centrifugation in order to isolate a progenitor cell fraction without immunocompetent cells. The purification technique of peripheral blood flow colony forming unit culture (CFU-c) by means of density gradient centrifugation and a combined depletion of various rosettes is described. The results of several 'in vitro' characteristics of purified CFU-c suspensions and of the plasma clot diffusion chamber culture technique are presented. Irradiation studies revealed that for both human bone marrow and peripheral blood the CFU-c were less radioresistant than clusters. Elimination of monocytes (and granulocytes) from the test suspensions induced an alteration in radiosensitivity pararmeters. The results obtained with the different techniques are described by analysing peripheral progenitor cell activity in myeloproliferative disorders. (Auth.)

  15. The dimensionality of professional commitment

    Directory of Open Access Journals (Sweden)

    Jeffrey J. Bagraim

    2003-10-01

    Full Text Available This paper examines the dimensionality of professional commitment amongst a sample of 240 South African actuaries. Data were obtained, via a mailed questionnaire, from members of the South African Actuarial Society employed in the financial services industry. Statistical analysis conducted on the data showed that the 3-component model first proposed by Meyer, Allen and Smith (1993 is appropriate for understanding professional commitment amongst South African professionals. The analysis also showed that South African actuaries are highly committed to their profession. Opsomming Hierdie artikel ondersoek die dimensionaliteit van professionele toewyding by ‘n steekproef van 240 Suid-Afrikaanse aktuarisse. Die data is verkry deur ‘n posvraelys aan lede van die Suid-Afrikaanse Aktuariële Vereniging wat in die finansiële dienstesektor werksaam was. Statistiese ontledings wat uitgevoer is op die data dui aan dat die driekomponentmodel, aanvanklik voorgestel deur Meyer, Allen en Smith (1993, geskik is om professionele toewyding by Suid-Afrikaanse beroepslui te verstaan. Die ontleding dui verder aan dat Suid-Afrikaanse aktuarisse hoogs toegewyd is aan hulle professie.

  16. CLoNe is a new method to target single progenitors and study their progeny in mouse and chick.

    Science.gov (United States)

    García-Moreno, Fernando; Vasistha, Navneet A; Begbie, Jo; Molnár, Zoltán

    2014-04-01

    Cell lineage analysis enables us to address pivotal questions relating to: the embryonic origin of cells and sibling cell relationships in the adult body; the contribution of progenitors activated after trauma or disease; and the comparison across species in evolutionary biology. To address such fundamental questions, several techniques for clonal labelling have been developed, each with its shortcomings. Here, we report a novel method, CLoNe that is designed to work in all vertebrate species and tissues. CLoNe uses a cocktail of labelling, targeting and transposition vectors that enables targeting of specific subpopulations of progenitor types with a combination of fluorophores resulting in multifluorescence that describes multiple clones per specimen. Furthermore, transposition into the genome ensures the longevity of cell labelling. We demonstrate the robustness of this technique in mouse and chick forebrain development, and show evidence that CLoNe will be broadly applicable to study clonal relationships in different tissues and species.

  17. Affinity maturation in an HIV broadly neutralizing B-cell lineage through reorientation of variable domains.

    Science.gov (United States)

    Fera, Daniela; Schmidt, Aaron G; Haynes, Barton F; Gao, Feng; Liao, Hua-Xin; Kepler, Thomas B; Harrison, Stephen C

    2014-07-15

    Rapidly evolving pathogens, such as human immunodeficiency and influenza viruses, escape immune defenses provided by most vaccine-induced antibodies. Proposed strategies to elicit broadly neutralizing antibodies require a deeper understanding of antibody affinity maturation and evolution of the immune response to vaccination or infection. In HIV-infected individuals, viruses and B cells evolve together, creating a virus-antibody "arms race." Analysis of samples from an individual designated CH505 has illustrated the interplay between an antibody lineage, CH103, and autologous viruses at various time points. The CH103 antibodies, relatively broad in their neutralization spectrum, interact with the CD4 binding site of gp120, with a contact dominated by CDRH3. We show by analyzing structures of progenitor and intermediate antibodies and by correlating them with measurements of binding to various gp120s that there was a shift in the relative orientation of the light- and heavy-chain variable domains during evolution of the CH103 lineage. We further show that mutations leading to this conformational shift probably occurred in response to insertions in variable loop 5 (V5) of the HIV envelope. The shift displaced the tips of the light chain away from contact with V5, making room for the inserted residues, which had allowed escape from neutralization by the progenitor antibody. These results, which document the selective mechanism underlying this example of a virus-antibody arms race, illustrate the functional significance of affinity maturation by mutation outside the complementarity determining region surface of the antibody molecule.

  18. Job insecurity, organisational commitment and work engagement ...

    African Journals Online (AJOL)

    understanding the concept of job insecurity as represented by two core ... commitment as a unidimensional construct based on employees' emotional .... outcomes such as increased job satisfaction, organisational commitment, motivation.

  19. Antecedents and Consequences of Affective Commitment

    NARCIS (Netherlands)

    Bloemer, J.M.M.; Odekerken-Schröder, G.J.

    2003-01-01

    The primary objective of this study is to assess the impact of three psychological antecedents (position involvement, volitional choice and informational complexity) on affective commitment in a financial service setting. Furthermore, this study addresses the consequences of affective commitment on

  20. X Inactivation and Progenitor Cancer Cells

    Directory of Open Access Journals (Sweden)

    Ruben Agrelo

    2011-04-01

    Full Text Available In mammals, silencing of one of the two X chromosomes is necessary to achieve dosage compensation. The 17 kb non-coding RNA called Xist triggers X inactivation. Gene silencing by Xist can only be achieved in certain contexts such as in cells of the early embryo and in certain hematopoietic progenitors where silencing factors are present. Moreover, these epigenetic contexts are maintained in cancer progenitors in which SATB1 has been identified as a factor related to Xist-mediated chromosome silencing.

  1. How do different types of community commitment influence brand commitment? The mediation of brand attachment.

    Science.gov (United States)

    Zhang, Ning; Zhou, Zhi-min; Su, Chen-ting; Zhou, Nan

    2013-11-01

    Although previous research indicates that participation in a brand community may foster consumer loyalty to the brand in question, research has seldom examined the mediating effect of community commitment on brand commitment. Drawing from the typologies of organizational commitment, we divide community commitment into three components: continuance community commitment (continuance CC), affective community commitment (affective CC), and normative community commitment (normative CC). We then assess the mediating role of brand attachment in the relationship between these three components and brand commitment. We test the hypotheses using a sample of online mobile phone brand communities in China. The empirical results reveal that brand attachment exerts an indirect (but not mediated) effect on the relationship between continuance CC and brand commitment and on the relationship between normative CC and brand commitment. We also find that it exerts a partial mediating effect on the relationship between affective CC and brand commitment. The findings contribute to the branding literature and have important implications for brand community management.

  2. 24 CFR 203.7 - Commitment process.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Commitment process. 203.7 Section 203.7 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued... Insurance, and Commitments § 203.7 Commitment process. For single family mortgage programs that are not...

  3. Commitment among Arab Adolescents in Israel.

    Science.gov (United States)

    Ben-Ari, Adital Tirosh; Azaiza, Faisal

    1998-01-01

    Examines 662 Arab adolescents' commitments to their own self-development, family, Arab people, and village along with the order in which these commitments are structured. Reveals that the two prevalent patterns of adolescent commitment, individualistic and collectivistic, demonstrate the adolescents' struggle with these value systems and the…

  4. 24 CFR 200.47 - Firm commitments.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Firm commitments. 200.47 Section 200.47 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued... Eligibility Requirements for Existing Projects Commitment Applications § 200.47 Firm commitments. A valid firm...

  5. Building commitment in a sports class

    DEFF Research Database (Denmark)

    Olesen, Jesper; Nielsen, Jens Christian

    The literature has traditionally considered commitment as an individual characteristic or condition of the individual. This means that one is inclined to think that it is those who have commitment who have the opportunity to become excellent performers within their sport. But what if commitment...

  6. Organizational and Client Commitment among Contracted Employees

    Science.gov (United States)

    Coyle-Shapiro, Jacqueline A-M.; Morrow, Paula C.

    2006-01-01

    This study examines affective commitment to employing and client organizations among long-term contracted employees, a new and growing employment classification. Drawing on organizational commitment and social exchange literatures, we propose two categories of antecedents of employee commitment to client organizations. We tested our hypotheses…

  7. Cell lineage mapping of taste bud cells and keratinocytes in the mouse tongue and soft palate.

    Science.gov (United States)

    Okubo, Tadashi; Clark, Cheryl; Hogan, Brigid L M

    2009-02-01

    The epithelium of the mouse tongue and soft palate consists of at least three distinct epithelial cell populations: basal cells, keratinized cells organized into filiform and fungiform papillae, and taste receptor cells present in tight clusters known as taste buds in the fungiform and circumvallate papillae and soft palate. All three cell types develop from the simple epithelium of the embryonic tongue and palate, and are continually replaced in the adult by cell turnover. Previous studies using pulse-chase tritiated thymidine labeling in the adult mouse provided evidence for a high rate of cell turnover in the keratinocytes (5-7 days) and taste buds (10 days). However, little is known about the localization and phenotype of the long-term stem or progenitor cells that give rise to the mature taste bud cells and surrounding keratinocytes in these gustatory tissues. Here, we make use of a tamoxifen-inducible K14-CreER transgene and the ROSA26 LacZ reporter allele to lineage trace the mature keratinocytes and taste bud cells of the early postnatal and adult mouse tongue and soft palate. Our results support the hypothesis that both the pore keratinocytes and receptor cells of the taste bud are derived from a common K14(+)K5(+)Trp63(+)Sox2(+) population of bipotential progenitor cells located outside the taste bud. The results are also compatible with models in which the keratinocytes of the filiform and fungiform papillae are derived from basal progenitor cells localized at the base of these structures.

  8. Quercetin inhibits adipogenesis of muscle progenitor cells in vitro

    Directory of Open Access Journals (Sweden)

    Tomoko Funakoshi

    2018-03-01

    Full Text Available Muscle satellite cells are committed myogenic progenitors capable of contributing to myogenesis to maintain adult muscle mass and function. Several experiments have demonstrated that muscle satellite cells can differentiate into adipocytes in vitro, supporting the mesenchymal differentiation potential of these cells. Moreover, muscle satellite cells may be a source of ectopic muscle adipocytes, explaining the lipid accumulation often observed in aged skeletal muscle (sarcopenia and in muscles of patients` with diabetes. Quercetin, a polyphenol, is one of the most abundant flavonoids distributed in edible plants, such as onions and apples, and possesses antioxidant, anticancer, and anti-inflammatory properties. In this study, we examined whether quercetin inhibited the adipogenesis of muscle satellite cells in vitro with primary cells from rat limbs by culture in the presence of quercetin under adipogenic conditions. Morphological observations, Oil Red-O staining results, triglyceride content analysis, and quantitative reverse transcription polymerase chain reaction revealed that quercetin was capable of inhibiting the adipogenic induction of muscle satellite cells into adipocytes in a dose-dependent manner by suppressing the transcript levels of adipogenic markers, such as peroxisome proliferator-activated receptor-γ and fatty acid binding protein 4. Our results suggested that quercetin inhibited the adipogenesis of muscle satellite cells in vitro by suppressing the transcription of adipogenic markers. Keywords: Quercetin, Muscle satellite cell, Differentiation, Intramuscular lipid

  9. Bmi1 overexpression in the cerebellar granule cell lineage of mice affects cell proliferation and survival without initiating medulloblastoma formation

    Directory of Open Access Journals (Sweden)

    Hourinaz Behesti

    2013-01-01

    BMI1 is a potent inducer of neural stem cell self-renewal and neural progenitor cell proliferation during development and in adult tissue homeostasis. It is overexpressed in numerous human cancers – including medulloblastomas, in which its functional role is unclear. We generated transgenic mouse lines with targeted overexpression of Bmi1 in the cerebellar granule cell lineage, a cell type that has been shown to act as a cell of origin for medulloblastomas. Overexpression of Bmi1 in granule cell progenitors (GCPs led to a decrease in cerebellar size due to decreased GCP proliferation and repression of the expression of cyclin genes, whereas Bmi1 overexpression in postmitotic granule cells improved cell survival in response to stress by altering the expression of genes in the mitochondrial cell death pathway and of Myc and Lef-1. Although no medulloblastomas developed in ageing cohorts of transgenic mice, crosses with Trp53−/− mice resulted in a low incidence of medulloblastoma formation. Furthermore, analysis of a large collection of primary human medulloblastomas revealed that tumours with a BMI1high TP53low molecular profile are significantly enriched in Group 4 human medulloblastomas. Our data suggest that different levels and timing of Bmi1 overexpression yield distinct cellular outcomes within the same cellular lineage. Importantly, Bmi1 overexpression at the GCP stage does not induce tumour formation, suggesting that BMI1 overexpression in GCP-derived human medulloblastomas probably occurs during later stages of oncogenesis and might serve to enhance tumour cell survival.

  10. Targeting CD147 for T to NK Lineage Reprogramming and Tumor Therapy.

    Science.gov (United States)

    Geng, Jie-Jie; Tang, Juan; Yang, Xiang-Min; Chen, Ruo; Zhang, Yang; Zhang, Kui; Miao, Jin-Lin; Chen, Zhi-Nan; Zhu, Ping

    2017-06-01

    CD147 is highly expressed on the surface of numerous tumor cells to promote invasion and metastasis. Targeting these cells with CD147-specific antibodies has been validated as an effective approach for lung and liver cancer therapy. In the immune system, CD147 is recognized as a co-stimulatory receptor and impacts the outcome of thymic selection. Using T cell-specific deletion, we showed here that in thymus CD147 is indispensable for the stable αβ T cell lineage commitment: loss of CD147 biases both multipotent DN (double negative) and fully committed DP (double positive) cells into innate NK-like lineages. Mechanistically, CD147 deficiency results in impaired Wnt signaling and expression of BCL11b, a master transcription factor in determining T cell identity. In addition, functional blocking of CD147 by antibody phenocopies genetic deletion to enrich NK-like cells in the periphery. Furthermore, using a melanoma model and orthotopic liver cancer transplants, we showed that the augmentation of NK-like cells strongly associates with resistance against tumor growth upon CD147 suppression. Therefore, besides its original function in tumorigenesis, CD147 is also an effective surface target for immune modulation in tumor therapy. Copyright © 2017. Published by Elsevier B.V.

  11. Targeting CD147 for T to NK Lineage Reprogramming and Tumor Therapy

    Directory of Open Access Journals (Sweden)

    Jie-Jie Geng

    2017-06-01

    Full Text Available CD147 is highly expressed on the surface of numerous tumor cells to promote invasion and metastasis. Targeting these cells with CD147-specific antibodies has been validated as an effective approach for lung and liver cancer therapy. In the immune system, CD147 is recognized as a co-stimulatory receptor and impacts the outcome of thymic selection. Using T cell-specific deletion, we showed here that in thymus CD147 is indispensable for the stable αβ T cell lineage commitment: loss of CD147 biases both multipotent DN (double negative and fully committed DP (double positive cells into innate NK-like lineages. Mechanistically, CD147 deficiency results in impaired Wnt signaling and expression of BCL11b, a master transcription factor in determining T cell identity. In addition, functional blocking of CD147 by antibody phenocopies genetic deletion to enrich NK-like cells in the periphery. Furthermore, using a melanoma model and orthotopic liver cancer transplants, we showed that the augmentation of NK-like cells strongly associates with resistance against tumor growth upon CD147 suppression. Therefore, besides its original function in tumorigenesis, CD147 is also an effective surface target for immune modulation in tumor therapy.

  12. Cataclysmic Variables as Supernova Ia Progenitors

    Directory of Open Access Journals (Sweden)

    Stella Kafka

    2012-06-01

    Full Text Available Although the identification of the progenitors of type Ia supernovae (SNeIa remains controversial, it is generally accepted that they originate from binary star systems in which at least one component is a carbon-oxygen white dwarf (WD; those systems are grouped under the wide umbrella of cataclysmic variables. Current theories for SNeIa progenitors hold that, either via Roche lobe overflow of the companion or via a wind, the WD accumulates hydrogen or helium rich material which is then burned to C and O onto the WD’s surface. However, the specifics of this scenario are far from being understood or defined, allowing for a wealth of theories fighting for attention and a dearth of observations to support them. I discuss the latest attempts to identify and study those controversial SNeIa progenitors. I also introduce the most promising progenitor in hand and I present observational diagnostics that can reveal more members of the category.

  13. Cardiac Progenitor Cell Extraction from Human Auricles

    KAUST Repository

    Di Nardo, Paolo; Pagliari, Francesca

    2017-01-01

    by precursor cells mostly embedded into the heart apex and in the atria. We have shown that an elective region of progenitor cell embedding is represented by the auricles, non-contractile atria appendages that can be easily sampled without harming the patient

  14. Commitment to self-rewards

    DEFF Research Database (Denmark)

    Koch, Alexander; Nafziger, Julia

    People often overcome self-control problems by promising to reward themselves for accomplishing a task. Such strategies based on self-administered rewards however require the person to believe that she would indeed deny herself the reward if she should fail to achieve the desired outcome. Drawing...... on Koszegi and Rabin's (2006) model of endogenous reference point formation, we show how a rational forward-looking individual can achieve such internal commitment. But our results also demonstrate the limitations of self regulation based on self-rewards....

  15. Commitment to Self-Rewards

    OpenAIRE

    Koch, Alexander K.; Nafziger, Julia

    2009-01-01

    Self-administered rewards are ubiquitous. They serve as incentives for personal accomplish¬ments and are widely recommended as tools for overcoming self-control problems. However, it seems puzzling why self-rewards can work: the prospect of a reward has a motivating force only if the threat of self-denial of the reward after low performance is credible. We explain how a rational forward-looking individual may achieve commitment to self-rewards, by applying Köszegi and Rabin's (2006) model of ...

  16. Our Commitment to Bioenergy Sustainability

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-06-18

    The U.S. Department of Energy’s Bioenergy Technologies Office (BETO) is committed to developing the resources, technologies, and systems needed to support a thriving bioenergy industry that protects natural resources and ad- vances environmental, economic, and social benefits. BETO’s Sustainability Technology Area proactively identifies and addresses issues that affect the scale-up potential, public acceptance, and long-term viability of advanced bioenergy systems; as a result, the area is critical to achieving BETO’s overall goals.

  17. SUPERNOVA REMNANT PROGENITOR MASSES IN M31

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, Zachary G.; Williams, Benjamin F.; Dalcanton, Julianne J.; Gilbert, Karoline M.; Fouesneau, Morgan; Weisz, Daniel R. [Department of Astronomy, University of Washington Seattle, Box 351580, WA 98195 (United States); Murphy, Jeremiah W. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Dolphin, Andrew E., E-mail: zachjenn@uw.edu, E-mail: adolphin@raytheon.com [Raytheon, 1151 East Hermans Road, Tucson, AZ 85706 (United States)

    2012-12-10

    Using Hubble Space Telescope photometry, we age-date 59 supernova remnants (SNRs) in the spiral galaxy M31 and use these ages to estimate zero-age main-sequence masses (M{sub ZAMS}) for their progenitors. To accomplish this, we create color-magnitude diagrams (CMDs) and employ CMD fitting to measure the recent star formation history of the regions surrounding cataloged SNR sites. We identify any young coeval population that likely produced the progenitor star, then assign an age and uncertainty to that population. Application of stellar evolution models allows us to infer the M{sub ZAMS} from this age. Because our technique is not contingent on identification or precise location of the progenitor star, it can be applied to the location of any known SNRs. We identify significant young star formation around 53 of the 59 SNRs and assign progenitor masses to these, representing a factor of {approx}2 increase over currently measured progenitor masses. We consider the remaining six SNRs as either probable Type Ia candidates or the result of core-collapse progenitors that have escaped their birth sites. In general, the distribution of recovered progenitor masses is bottom-heavy, showing a paucity of the most massive stars. If we assume a single power-law distribution, dN/dM{proportional_to}M{sup {alpha}}, then we find a distribution that is steeper than a Salpeter initial mass function (IMF) ({alpha} = -2.35). In particular, we find values of {alpha} outside the range -2.7 {>=} {alpha} {>=} -4.4 to be inconsistent with our measured distribution at 95% confidence. If instead we assume a distribution that follows a Salpeter IMF up to some maximum mass, then we find that values of M{sub Max} > 26 are inconsistent with the measured distribution at 95% confidence. In either scenario, the data suggest that some fraction of massive stars may not explode. The result is preliminary and requires more SNRs and further analysis. In addition, we use our distribution to estimate a

  18. 2D and 3D Stem Cell Models of Primate Cortical Development Identify Species-Specific Differences in Progenitor Behavior Contributing to Brain Size.

    Science.gov (United States)

    Otani, Tomoki; Marchetto, Maria C; Gage, Fred H; Simons, Benjamin D; Livesey, Frederick J

    2016-04-07

    Variation in cerebral cortex size and complexity is thought to contribute to differences in cognitive ability between humans and other animals. Here we compare cortical progenitor cell output in humans and three nonhuman primates using directed differentiation of pluripotent stem cells (PSCs) in adherent two-dimensional (2D) and organoid three-dimensional (3D) culture systems. Clonal lineage analysis showed that primate cortical progenitors proliferate for a protracted period of time, during which they generate early-born neurons, in contrast to rodents, where this expansion phase largely ceases before neurogenesis begins. The extent of this additional cortical progenitor expansion differs among primates, leading to differences in the number of neurons generated by each progenitor cell. We found that this mechanism for controlling cortical size is regulated cell autonomously in culture, suggesting that primate cerebral cortex size is regulated at least in part at the level of individual cortical progenitor cell clonal output. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  19. Characterization of Hemagglutinin Negative Botulinum Progenitor Toxins

    Directory of Open Access Journals (Sweden)

    Suzanne R. Kalb

    2017-06-01

    Full Text Available Botulism is a disease involving intoxication with botulinum neurotoxins (BoNTs, toxic proteins produced by Clostridium botulinum and other clostridia. The 150 kDa neurotoxin is produced in conjunction with other proteins to form the botulinum progenitor toxin complex (PTC, alternating in size from 300 kDa to 500 kDa. These progenitor complexes can be classified into hemagglutinin positive or hemagglutinin negative, depending on the ability of some of the neurotoxin-associated proteins (NAPs to cause hemagglutination. The hemagglutinin positive progenitor toxin complex consists of BoNT, nontoxic non-hemagglutinin (NTNH, and three hemagglutinin proteins; HA-70, HA-33, and HA-17. Hemagglutinin negative progenitor toxin complexes contain BoNT and NTNH as the minimally functional PTC (M-PTC, but not the three hemagglutinin proteins. Interestingly, the genome of hemagglutinin negative progenitor toxin complexes comprises open reading frames (orfs which encode for three proteins, but the existence of these proteins has not yet been extensively demonstrated. In this work, we demonstrate that these three proteins exist and form part of the PTC for hemagglutinin negative complexes. Several hemagglutinin negative strains producing BoNT/A, /E, and /F were found to contain the three open reading frame proteins. Additionally, several BoNT/A-containing bivalent strains were examined, and NAPs from both genes, including the open reading frame proteins, were associated with BoNT/A. The open reading frame encoded proteins are more easily removed from the botulinum complex than the hemagglutinin proteins, but are present in several BoNT/A and /F toxin preparations. These are not easily removed from the BoNT/E complex, however, and are present even in commercially-available purified BoNT/E complex.

  20. Defining the cellular lineage hierarchy in the interfollicular epidermis of adult skin.

    Science.gov (United States)

    Sada, Aiko; Jacob, Fadi; Leung, Eva; Wang, Sherry; White, Brian S; Shalloway, David; Tumbar, Tudorita

    2016-06-01

    The interfollicular epidermis regenerates from heterogeneous basal skin cell populations that divide at different rates. It has previously been presumed that infrequently dividing basal cells known as label-retaining cells (LRCs) are stem cells, whereas non-LRCs are short-lived progenitors. Here we employ the H2B-GFP pulse-chase system in adult mouse skin and find that epidermal LRCs and non-LRCs are molecularly distinct and can be differentiated by Dlx1(CreER) and Slc1a3(CreER) genetic marking, respectively. Long-term lineage tracing and mathematical modelling of H2B-GFP dilution data show that LRCs and non-LRCs constitute two distinct stem cell populations with different patterns of proliferation, differentiation and upward cellular transport. During homeostasis, these populations are enriched in spatially distinct skin territories and can preferentially produce unique differentiated lineages. On wounding or selective killing, they can temporarily replenish each other's territory. These two discrete interfollicular stem cell populations are functionally interchangeable and intrinsically well adapted to thrive in distinct skin environments.

  1. AMPK governs lineage specification through Tfeb-dependent regulation of lysosomes.

    Science.gov (United States)

    Young, Nathan P; Kamireddy, Anwesh; Van Nostrand, Jeanine L; Eichner, Lillian J; Shokhirev, Maxim Nikolaievich; Dayn, Yelena; Shaw, Reuben J

    2016-03-01

    Faithful execution of developmental programs relies on the acquisition of unique cell identities from pluripotent progenitors, a process governed by combinatorial inputs from numerous signaling cascades that ultimately dictate lineage-specific transcriptional outputs. Despite growing evidence that metabolism is integrated with many molecular networks, how pathways that control energy homeostasis may affect cell fate decisions is largely unknown. Here, we show that AMP-activated protein kinase (AMPK), a central metabolic regulator, plays critical roles in lineage specification. Although AMPK-deficient embryonic stem cells (ESCs) were normal in the pluripotent state, these cells displayed profound defects upon differentiation, failing to generate chimeric embryos and preferentially adopting an ectodermal fate at the expense of the endoderm during embryoid body (EB) formation. AMPK(-/-) EBs exhibited reduced levels of Tfeb, a master transcriptional regulator of lysosomes, leading to diminished endolysosomal function. Remarkably, genetic loss of Tfeb also yielded endodermal defects, while AMPK-null ESCs overexpressing this transcription factor normalized their differential potential, revealing an intimate connection between Tfeb/lysosomes and germ layer specification. The compromised endolysosomal system resulting from AMPK or Tfeb inactivation blunted Wnt signaling, while up-regulating this pathway restored expression of endodermal markers. Collectively, these results uncover the AMPK pathway as a novel regulator of cell fate determination during differentiation. © 2016 Young et al.; Published by Cold Spring Harbor Laboratory Press.

  2. Macrophage colony-stimulating factor receptor marks and regulates a fetal myeloid-primed B-cell progenitor in mice.

    Science.gov (United States)

    Zriwil, Alya; Böiers, Charlotta; Wittmann, Lilian; Green, Joanna C A; Woll, Petter S; Jacobsen, Sten Eirik W; Sitnicka, Ewa

    2016-07-14

    Although it is well established that unique B-cell lineages develop through distinct regulatory mechanisms during embryonic development, much less is understood about the differences between embryonic and adult B-cell progenitor cells, likely to underpin the genetics and biology of infant and childhood PreB acute lymphoblastic leukemia (PreB-ALL), initiated by distinct leukemia-initiating translocations during embryonic development. Herein, we establish that a distinct subset of the earliest CD19(+) B-cell progenitors emerging in the E13.5 mouse fetal liver express the colony-stimulating factor-1 receptor (CSF1R), previously thought to be expressed, and play a lineage-restricted role in development of myeloid lineages, and macrophages in particular. These early embryonic CSF1R(+)CD19(+) ProB cells also express multiple other myeloid genes and, in line with this, possess residual myeloid as well as B-cell, but not T-cell lineage potential. Notably, these CSF1R(+) myeloid-primed ProB cells are uniquely present in a narrow window of embryonic fetal liver hematopoiesis and do not persist in adult bone marrow. Moreover, analysis of CSF1R-deficient mice establishes a distinct role of CSF1R in fetal B-lymphopoiesis. CSF1R(+) myeloid-primed embryonic ProB cells are relevant for infant and childhood PreB-ALLs, which frequently have a bi-phenotypic B-myeloid phenotype, and in which CSF1R-rearrangements have recently been reported. © 2016 by The American Society of Hematology.

  3. Cytokine-Regulated GADD45G Induces Differentiation and Lineage Selection in Hematopoietic Stem Cells

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    Frederic B. Thalheimer

    2014-07-01

    Full Text Available The balance of self-renewal and differentiation in long-term repopulating hematopoietic stem cells (LT-HSC must be strictly controlled to maintain blood homeostasis and to prevent leukemogenesis. Hematopoietic cytokines can induce differentiation in LT-HSCs; however, the molecular mechanism orchestrating this delicate balance requires further elucidation. We identified the tumor suppressor GADD45G as an instructor of LT-HSC differentiation under the control of differentiation-promoting cytokine receptor signaling. GADD45G immediately induces and accelerates differentiation in LT-HSCs and overrides the self-renewal program by specifically activating MAP3K4-mediated MAPK p38. Conversely, the absence of GADD45G enhances the self-renewal potential of LT-HSCs. Videomicroscopy-based tracking of single LT-HSCs revealed that, once GADD45G is expressed, the development of LT-HSCs into lineage-committed progeny occurred within 36 hr and uncovered a selective lineage choice with a severe reduction in megakaryocytic-erythroid cells. Here, we report an unrecognized role of GADD45G as a central molecular linker of extrinsic cytokine differentiation and lineage choice control in hematopoiesis.

  4. NOV/CCN3 impairs muscle cell commitment and differentiation

    International Nuclear Information System (INIS)

    Calhabeu, Frederico; Lafont, Jerome; Le Dreau, Gwenvael; Laurent, Maryvonne; Kazazian, Chantal; Schaeffer, Laurent; Martinerie, Cecile; Dubois, Catherine

    2006-01-01

    NOV (nephroblastoma overexpressed) is a member of a family of proteins which encodes secreted matrix-associated proteins. NOV is expressed during development in dermomyotome and limb buds, but its functions are still poorly defined. In order to understand the role of NOV in myogenic differentiation, C2C12 cells overexpressing NOV (C2-NOV) were generated. These cells failed to engage into myogenic differentiation, whereas they retained the ability to differentiate into osteoblasts. In differentiating conditions, C2-NOV cells remained proliferative, failed to express differentiation markers and lost their ability to form myotubes. Inhibition of differentiation by NOV was also observed with human primary muscle cells. Further examination of C2-NOV cells revealed a strong downregulation of the myogenic determination genes MyoD and Myf5 and of IGF-II expression. MyoD forced expression in C2-NOV was sufficient to restore differentiation and IGF-II induction whereas 10 -6 M insulin treatment had no effects. NOV therefore acts upstream of MyoD and does not affect IGF-II induction and signaling. HES1, a target of Notch, previously proposed to mediate NOV action, was not implicated in the inhibition of differentiation. We propose that NOV is a specific cell fate regulator in the myogenic lineage, acting negatively on key myogenic genes thus controlling the transition from progenitor cells to myoblasts

  5. Isoform-specific potentiation of stem and progenitor cell engraftment by AML1/RUNX1.

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    Shinobu Tsuzuki

    2007-05-01

    Full Text Available AML1/RUNX1 is the most frequently mutated gene in leukaemia and is central to the normal biology of hematopoietic stem and progenitor cells. However, the role of different AML1 isoforms within these primitive compartments is unclear. Here we investigate whether altering relative expression of AML1 isoforms impacts the balance between cell self-renewal and differentiation in vitro and in vivo.The human AML1a isoform encodes a truncated molecule with DNA-binding but no transactivation capacity. We used a retrovirus-based approach to transduce AML1a into primitive haematopoietic cells isolated from the mouse. We observed that enforced AML1a expression increased the competitive engraftment potential of murine long-term reconstituting stem cells with the proportion of AML1a-expressing cells increasing over time in both primary and secondary recipients. Furthermore, AML1a expression dramatically increased primitive and committed progenitor activity in engrafted animals as assessed by long-term culture, cobblestone formation, and colony assays. In contrast, expression of the full-length isoform AML1b abrogated engraftment potential. In vitro, AML1b promoted differentiation while AML1a promoted proliferation of progenitors capable of short-term lymphomyeloid engraftment. Consistent with these findings, the relative abundance of AML1a was highest in the primitive stem/progenitor compartment of human cord blood, and forced expression of AML1a in these cells enhanced maintenance of primitive potential both in vitro and in vivo.These data demonstrate that the "a" isoform of AML1 has the capacity to potentiate stem and progenitor cell engraftment, both of which are required for successful clinical transplantation. This activity is consistent with its expression pattern in both normal and leukaemic cells. Manipulating the balance of AML1 isoform expression may offer novel therapeutic strategies, exploitable in the contexts of leukaemia and also in cord blood

  6. Canada's commitment to nuclear technology

    International Nuclear Information System (INIS)

    Stewart, Murray J.

    1998-01-01

    This paper gives a broad update on all facets of the Canadian nuclear industry and demonstrates Canada's continuing commitment to nuclear technology. Canada has developed a global leadership position in nuclear technology for power generation, uranium production and isotope supply. This commitment is being further enhanced by successes in international markets with Candu technology, new uranium mine developments in our province of Saskatchewan, and expanding isotope capabilities including the construction of two new production reactors. Korea's economy is benefiting through collaboration with Canada's leading nuclear companies, both in Korea and Canada. These collaborations have the potential to expand considerably with the implementation of the Kyoto Framework Convention on Climate Change and the anticipated increased demand for new nuclear power generation installations in all major global markets. Much has been publicized about the situation surrounding Ontario Hydro Nuclear and its nuclear recovery program. This paper gives the background and highlights the actions within Ontario and Ontario Hydro designed to ensure the long term recovery of all twenty nuclear units in Ontario. The presentation at the conference will bring the audience completely up-to-date on recent events. (author)

  7. Origin of hemopoietic stromal progenitor cells in chimeras

    International Nuclear Information System (INIS)

    Chertkov, J.L.; Drize, N.J.; Gurevitch, O.A.; Samoylova, R.S.

    1985-01-01

    Intravenously injected bone marrow cells do not participate in the regeneration of hemopoietic stromal progenitors in irradiated mice, nor in the curetted parts of the recipient's marrow. The hemopoietic stromal progenitors in allogeneic chimeras are of recipient origin. The adherent cell layer (ACL) of long-term cultures of allogeneic chimera bone marrow contains only recipient hemopoietic stromal progenitors. However, in ectopic hemopoietic foci produced by marrow implantation under the renal capsule and repopulated by the recipient hemopoietic cells after irradiation and reconstitution by syngeneic hemopoietic cells, the stromal progenitors were of implant donor origin, as were stromal progenitors of the ACL in long-term cultures of hemopoietic cells from ectopic foci. Our results confirm that the stromal and hemopoietic progenitors differ in origin and that hemopoietic stromal progenitors are not transplantable by the intravenous route in mice

  8. The negative impact of Wnt signaling on megakaryocyte and primitive erythroid progenitors derived from human embryonic stem cells

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    Prasuna Paluru

    2014-03-01

    Full Text Available The Wnt gene family consists of structurally related genes encoding secreted signaling molecules that have been implicated in many developmental processes, including regulation of cell fate and patterning during embryogenesis. Previously, we found that Wnt signaling is required for primitive or yolk sac-derived-erythropoiesis using the murine embryonic stem cell (ESC system. Here, we examine the effect of Wnt signaling on the formation of early hematopoietic progenitors derived from human ESCs. The first hematopoietic progenitor cells in the human ESC system express the pan-hematopoietic marker CD41 and the erythrocyte marker, glycophorin A or CD235. We have developed a novel serum-free, feeder-free, adherent differentiation system that can efficiently generate large numbers of CD41 + CD235+ cells. We demonstrate that this cell population contains progenitors not just for primitive erythroid and megakaryocyte cells but for the myeloid lineage as well and term this population the primitive common myeloid progenitor (CMP. Treatment of mesoderm-specified cells with Wnt3a led to a loss of hematopoietic colony-forming ability while the inhibition of canonical Wnt signaling with DKK1 led to an increase in the number of primitive CMPs. Canonical Wnt signaling also inhibits the expansion and/or survival of primitive erythrocytes and megakaryocytes, but not myeloid cells, derived from this progenitor population. These findings are in contrast to the role of Wnt signaling during mouse ESC differentiation and demonstrate the importance of the human ESC system in studying species-specific differences in development.

  9. At the end of the line: independent overwater colonizations of the Solomon Islands by a hyperdiverse trans-Wallacean lizard lineage (Cyrtodactylus: Gekkota: Squamata)

    Science.gov (United States)

    Oliver, Paul M.; Travers, Scott L; Richmond, Jonathan Q.; Pikacha, Patrick; Fisher, Robert N.

    2018-01-01

    The islands of East Melanesia have generated key insights into speciation processes and community assembly. However, when and how these islands began to form, emerge and accumulate endemic taxa remains poorly understood. Here, we show that two divergent lineages within the world’s most diverse genus of geckos (Cyrtodactylus) occur in the Solomon Islands. One large-bodied species is nested within a radiation from far eastern New Guinea, with inferred colonization, spread and diversification since the late Miocene. In contrast, a newly sampled and relatively small species with a restricted distribution on Guadalcanal Island is a relict that diverged from extant congeners around the early to mid-Miocene. Similar Miocene divergences from extralimital relatives have been inferred for other endemic bird, bat and lizard lineages in East Melanesia. In contrast, across all lineages (including divergent relictual lineages), there is little evidence for endemic in situ diversification within East Melanesia predating the Pliocene (especially in the Solomon Islands). While some East Melanesian endemic lineages may have origins on progenitor islands during the Miocene or even earlier, current evidence suggests the in situ diversification and assembly of extant biological communities commenced around the end of the Miocene.

  10. Uncovering the mutation-fixation correlation in short lineages

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    Vallender Eric J

    2007-09-01

    Full Text Available Abstract Background We recently reported a highly unexpected positive correlation between the fixation probability of nonsynonymous mutations (estimated by ω and neutral mutation rate (estimated by Ks in mammalian lineages. However, this positive correlation was observed for lineages with relatively long divergence time such as the human-mouse lineage, and was not found for very short lineages such as the human-chimpanzee lineage. It was previously unclear how to interpret this discrepancy. It may indicate that the positive correlation between ω and Ks in long lineages is a false finding. Alternatively, it may reflect a biologically meaningful difference between various lineages. Finally, the lack of positive correlation in short lineages may be the result of methodological artifacts. Results Here we show that a strong positive correlation can indeed be seen in short lineages when a method was introduced to correct for the inherently high levels of stochastic noise in the use of Ks as an estimator of neutral mutation rate. Thus, the previously noted lack of positive correlation between ω and Ks in short lineages is due to stochastic noise in Ks that makes it a far less reliable estimator of neutral mutation rate in short lineages as compared to long lineages. Conclusion A positive correlation between ω and Ks can be observed in all mammalian lineages for which large amounts of sequence data are available, including very short lineages. It confirms the authenticity of this highly unexpected correlation, and argues that the correction likely applies broadly across all mammals and perhaps even non-mammalian species.

  11. Lineage specific recombination rates and microevolution in Listeria monocytogenes

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    Nightingale Kendra K

    2008-10-01

    Full Text Available Abstract Background The bacterium Listeria monocytogenes is a saprotroph as well as an opportunistic human foodborne pathogen, which has previously been shown to consist of at least two widespread lineages (termed lineages I and II and an uncommon lineage (lineage III. While some L. monocytogenes strains show evidence for considerable diversification by homologous recombination, our understanding of the contribution of recombination to L. monocytogenes evolution is still limited. We therefore used STRUCTURE and ClonalFrame, two programs that model the effect of recombination, to make inferences about the population structure and different aspects of the recombination process in L. monocytogenes. Analyses were performed using sequences for seven loci (including the house-keeping genes gap, prs, purM and ribC, the stress response gene sigB, and the virulence genes actA and inlA for 195 L. monocytogenes isolates. Results Sequence analyses with ClonalFrame and the Sawyer's test showed that recombination is more prevalent in lineage II than lineage I and is most frequent in two house-keeping genes (ribC and purM and the two virulence genes (actA and inlA. The relative occurrence of recombination versus point mutation is about six times higher in lineage II than in lineage I, which causes a higher genetic variability in lineage II. Unlike lineage I, lineage II represents a genetically heterogeneous population with a relatively high proportion (30% average of genetic material imported from external sources. Phylograms, constructed with correcting for recombination, as well as Tajima's D data suggest that both lineages I and II have suffered a population bottleneck. Conclusion Our study shows that evolutionary lineages within a single bacterial species can differ considerably in the relative contributions of recombination to genetic diversification. Accounting for recombination in phylogenetic studies is critical, and new evolutionary models that

  12. Assessment of benzene-induced hematotoxicity using a human-like hematopoietic lineage in NOD/Shi-scid/IL-2Rγnull mice.

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    Masayuki Takahashi

    Full Text Available Despite recent advancements, it is still difficult to evaluate in vivo responses to toxicants in humans. Development of a system that can mimic the in vivo responses of human cells will enable more accurate health risk assessments. A surrogate human hematopoietic lineage can be established in NOD/Shi-scid/IL-2Rγ(null (NOG mice by transplanting human hematopoietic stem/progenitor cells (Hu-NOG mice. Here, we first evaluated the toxic response of human-like hematopoietic lineage in NOG mice to a representative toxic agent, benzene. Flow cytometric analysis showed that benzene caused a significant decrease in the number of human hematopoietic stem/progenitor cells in the bone marrow and the number of human leukocytes in the peripheral blood and hematopoietic organs. Next, we established chimeric mice by transplanting C57BL/6 mouse-derived bone marrow cells into NOG mice (Mo-NOG mice. A comparison of the degree of benzene-induced hematotoxicity in donor-derived hematopoietic lineage cells within Mo-NOG mice indicated that the toxic response of Hu-NOG mice reflected interspecies differences in susceptibilities to benzene. Responses to the toxic effects of benzene were greater in lymphoid cells than in myeloid cells in Mo-NOG and Hu-NOG mice. These findings suggested that Hu-NOG mice may be a powerful in vivo tool for assessing hematotoxicity in humans, while accounting for interspecies differences.

  13. Experimental evidence showing that no mitotically active female germline progenitors exist in postnatal mouse ovaries.

    Science.gov (United States)

    Zhang, Hua; Zheng, Wenjing; Shen, Yan; Adhikari, Deepak; Ueno, Hiroo; Liu, Kui

    2012-07-31

    It has been generally accepted for more than half a century that, in most mammalian species, oocytes cannot renew themselves in postnatal or adult life, and that the number of oocytes is already fixed in fetal or neonatal ovaries. This assumption, however, has been challenged over the past decade. In this study, we have taken an endogenous genetic approach to this question and generated a multiple fluorescent Rosa26(rbw/+);Ddx4-Cre germline reporter mouse model for in vivo and in vitro tracing of the development of female germline cell lineage. Through live cell imaging and de novo folliculogenesis experiments, we show that the Ddx4-expressing cells from postnatal mouse ovaries did not enter mitosis, nor did they contribute to oocytes during de novo folliculogenesis. Our results provide evidence that supports the traditional view that no postnatal follicular renewal occurs in mammals, and no mitotically active Ddx4-expressing female germline progenitors exist in postnatal mouse ovaries.

  14. Development of Cortical GABAergic Neurons: Interplay of progenitor diversity and environmental factors on fate specification

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    Juliana Alves Brandão

    2015-04-01

    Full Text Available Cortical GABAergic interneurons constitute an extremely diverse population of cells organized in a well-defined topology of precisely interconnected cells. They play a crucial role regulating inhibitory-excitatory balance in brain circuits, gating sensory perception and regulating spike timing to brain oscillations during distinct behaviors. Dysfunctions in the establishment of proper inhibitory circuits have been associated to several brain disorders such as autism, epilepsy and schizophrenia. In the rodent adult cortex, inhibitory neurons are generated during the second gestational week from distinct progenitor lineages located in restricted domains of the ventral telencephalon. However, only recently, studies have revealed some of the mechanisms generating the heterogeneity of neuronal subtypes and their modes of integration in brain networks. Here we will discuss some the events involved in the production of cortical GABAergic neuron diversity with focus on the interaction between intrinsically driven genetic programs and environmental signals during development.

  15. Vitamin D receptor–retinoid X receptor heterodimer signaling regulates oligodendrocyte progenitor cell differentiation

    Science.gov (United States)

    de la Fuente, Alerie Guzman; Errea, Oihana; van Wijngaarden, Peter; Gonzalez, Ginez A.; Kerninon, Christophe; Jarjour, Andrew A.; Lewis, Hilary J.; Jones, Clare A.; Nait-Oumesmar, Brahim; Zhao, Chao; Huang, Jeffrey K.; ffrench-Constant, Charles

    2015-01-01

    The mechanisms regulating differentiation of oligodendrocyte (OLG) progenitor cells (OPCs) into mature OLGs are key to understanding myelination and remyelination. Signaling via the retinoid X receptor γ (RXR-γ) has been shown to be a positive regulator of OPC differentiation. However, the nuclear receptor (NR) binding partner of RXR-γ has not been established. In this study we show that RXR-γ binds to several NRs in OPCs and OLGs, one of which is vitamin D receptor (VDR). Using pharmacological and knockdown approaches we show that RXR–VDR signaling induces OPC differentiation and that VDR agonist vitamin D enhances OPC differentiation. We also show expression of VDR in OLG lineage cells in multiple sclerosis. Our data reveal a role for vitamin D in the regenerative component of demyelinating disease and identify a new target for remyelination medicines. PMID:26644513

  16. Pipeline for Tracking Neural Progenitor Cells

    DEFF Research Database (Denmark)

    Vestergaard, Jacob Schack; Dahl, Anders Lindbjerg; Holm, Peter

    2012-01-01

    Automated methods for neural stem cell lineage construction become increasingly important due to the large amount of data produced from time lapse imagery of in vitro cell growth experiments. Segmentation algorithms with the ability to adapt to the problem at hand and robust tracking methods play...... a key role in constructing these lineages. We present here a tracking pipeline based on learning a dictionary of discriminative image patches for segmentation and a graph formulation of the cell matching problem incorporating topology changes and acknowledging the fact that segmentation errors do occur...

  17. Beijing: a conference of commitments?

    Science.gov (United States)

    Davis, S

    1996-05-01

    The author of this article holds the view that the Declaration and Platform for Action at the UN Fourth World Conference on Women held in Beijing in 1995 was the product of the most highly participatory process ever organized under the auspices of the UN. The Declaration and Platform expressed the strongest views on gender equality, empowerment, and justice that governments have ever endorsed. These documents were the consolidation of gains made by women in previous UN conferences. The 135-page Platform can be used at all levels of decision making. Governments and international can be held accountable for its provisions. The Platform exposes the problems violence and exploitation against women and girls as well as the revelation that environmental destruction is due to an unsustainable pattern of consumption and production, particularly in developed countries. Conference participants included about 3000 nongovernmental groups (NGOs). The Women's Linkage Caucus and WEDO served to facilitate the advocacy process by providing briefings on text still under negotiation and providing on-line recommendations from the 1995 and 1994 Commission on the Status of Women preparatory committee meetings. A scoreboard that tracked government's commitment at the 1995 preparatory committee meetings was reinstated in Beijing. The information was conveyed on the Internet. The European Union is credited with diluting the language about government commitment to the Platform. Governments are still given responsibility for implementation, and the need for political will is stressed (paragraph 293). Paragraph 297 indicates the process for implementation of the Platform and coordination with NGOs. Although the Platform recognizes the importance of women's groups and other NGOs, the responsibility for implementation is still given to governments.

  18. Slug controls stem/progenitor cell growth dynamics during mammary gland morphogenesis.

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    Mayssa Nassour

    Full Text Available Morphogenesis results from the coordination of distinct cell signaling pathways controlling migration, differentiation, apoptosis, and proliferation, along stem/progenitor cell dynamics. To decipher this puzzle, we focused on epithelial-mesenchymal transition (EMT "master genes". EMT has emerged as a unifying concept, involving cell-cell adhesion, migration and apoptotic pathways. EMT also appears to mingle with stemness. However, very little is known on the physiological role and relevance of EMT master-genes. We addressed this question during mammary morphogenesis. Recently, a link between Slug/Snai2 and stemness has been described in mammary epithelial cells, but EMT master genes actual localization, role and targets during mammary gland morphogenesis are not known and we focused on this basic question.Using a Slug-lacZ transgenic model and immunolocalization, we located Slug in a distinct subpopulation covering about 10-20% basal cap and duct cells, mostly cycling cells, coexpressed with basal markers P-cadherin, CK5 and CD49f. During puberty, Slug-deficient mammary epithelium exhibited a delayed development after transplantation, contained less cycling cells, and overexpressed CK8/18, ER, GATA3 and BMI1 genes, linked to luminal lineage. Other EMT master genes were overexpressed, suggesting compensation mechanisms. Gain/loss-of-function in vitro experiments confirmed Slug control of mammary epithelial cell luminal differentiation and proliferation. In addition, they showed that Slug enhances specifically clonal mammosphere emergence and growth, cell motility, and represses apoptosis. Strikingly, Slug-deprived mammary epithelial cells lost their potential to generate secondary clonal mammospheres.We conclude that Slug pathway controls the growth dynamics of a subpopulation of cycling progenitor basal cells during mammary morphogenesis. Overall, our data better define a key mechanism coordinating cell lineage dynamics and morphogenesis, and

  19. Retinal and anterior eye compartments derive from a common progenitor pool in the avian optic cup

    Science.gov (United States)

    Venters, Sara J.; Cuenca, Paulina D.

    2011-01-01

    Purpose The optic cup is created through invagination of the optic vesicle. The morphogenetic rearrangement creates a double-layered cup, with a hinge (the Optic Cup Lip) where the epithelium bends back upon itself. Shortly after the optic cup forms, it is thought to be sub-divided into separate lineages: i) pigmented epithelium in the outer layer; ii) presumptive iris and ciliary body at the most anterior aspect of the inner layer; and iii) presumptive neural retina in the remainder of the inner layer. We test the native developmental potential of the anterior cup to determine if it normally contributes to the retina. Methods Vital dye and green fluorescent protein (GFP) expressing replication-incompetent retroviral vectors were used to label cells in the nascent optic cup and follow their direct progeny throughout development. Label was applied to either the optic cup lip (n=40), or to the domain just posterior to the lip (n=20). Retroviral labeling is a permanent lineage marker and enabled the analysis of advanced stages of development. Results Labeling within the optic cup gave rise to labeled progeny in the posterior optic cup that differentiated as neural retina (20 of 20). In contrast, labeling cells in the optic cup lip gave rise to progeny of labeled cells arrayed in a linear progression, from the lip into the neural retina (36 of 40). Label was retained in cells at the optic cup lip, regardless of age at examination. In older embryos, labeled progeny delaminated from the optic cup lip to differentiate as muscle of the pupillary margin. Conclusions The data show that the cells at the optic cup lip are a common progenitor population for pigmented epithelium, anterior eye tissues (ciliary body, iris, and pupillary muscle) and retinal neurons. The findings are supportive of an interpretation where the optic cup lip is a specialized niche containing a multipotent progenitor population. PMID:22219630

  20. THE AGES OF TYPE Ia SUPERNOVA PROGENITORS

    International Nuclear Information System (INIS)

    Brandt, Timothy D.; Aubourg, Eric; Strauss, Michael A.; Tojeiro, Rita; Heavens, Alan; Jimenez, Raul

    2010-01-01

    Using light curves and host galaxy spectra of 101 Type Ia supernovae (SNe Ia) with redshift z ∼ 2.4 Gyr. We find that each channel contributes roughly half of the Type Ia rate in our reference sample. We also construct the average spectra of high-stretch and low-stretch SN Ia host galaxies, and find that the difference of these spectra looks like a main-sequence B star with nebular emission lines indicative of star formation. This supports our finding that there are two populations of SNe Ia, and indicates that the progenitors of high-stretch supernovae are at the least associated with very recent star formation in the last few tens of Myr. Our results provide valuable constraints for models of Type Ia progenitors and may help improve the calibration of SNe Ia as standard candles.

  1. Interneuron progenitor transplantation to treat CNS dysfunction

    Directory of Open Access Journals (Sweden)

    Muhammad O Chohan

    2016-08-01

    Full Text Available Due to the inadequacy of endogenous repair mechanisms diseases of the nervous system remain a major challenge to scientists and clinicians. Stem cell based therapy is an exciting and viable strategy that has been shown to ameliorate or even reverse symptoms of CNS dysfunction in preclinical animal models. Of particular importance has been the use of GABAergic interneuron progenitors as a therapeutic strategy. Born in the neurogenic niches of the ventral telencephalon, interneuron progenitors retain their unique capacity to disperse, integrate and induce plasticity in adult host circuitries following transplantation. Here we discuss the potential of interneuron based transplantation strategies as it relates to CNS disease therapeutics. We also discuss mechanisms underlying their therapeutic efficacy and some of the challenges that face the field.

  2. Factors Affecting Organizational Commitment in Navy Corpsmen.

    Science.gov (United States)

    Booth-Kewley, Stephanie; Dell'Acqua, Renée G; Thomsen, Cynthia J

    2017-07-01

    Organizational commitment is a psychological state that has a strong impact on the likelihood that employees will remain with an organization. Among military personnel, organizational commitment is predictive of a number of important outcomes, including reenlistment intentions, job performance, morale, and perceived readiness. Because of the unique challenges and experiences associated with military service, it may be that organizational commitment is even more critical in the military than in civilian populations. Despite the essential role that they play in protecting the health of other service members, little is known about the factors that influence Navy Corpsmen's organizational commitment. This study investigated demographic and psychosocial factors that may be associated with organizational commitment among Corpsmen. Surveys of organizational commitment and possible demographic and psychosocial correlates of organizational commitment were completed by 1,597 male, active duty Navy Corpsmen attending Field Medical Training Battalion-West, Camp Pendleton, California. Bivariate correlations and hierarchical multiple regression analyses were used to determine significant predictors of organizational commitment. Of the 12 demographic and psychosocial factors examined, 6 factors emerged as significant predictors of organizational commitment in the final model: preservice motivation to be a Corpsman, positive perceptions of Corpsman training, confidence regarding promotions, occupational self-efficacy, social support for a Corpsman career, and lower depression. Importantly, a number of the factors that emerged as significant correlates of organizational commitment in this study are potentially modifiable. These factors include confidence regarding promotions, positive perceptions of Corpsman training, and occupational self-efficacy. It is recommended that military leaders and policy-makers take concrete steps to address these factors, thereby strengthening

  3. Neural Progenitors Adopt Specific Identities by Directly Repressing All Alternative Progenitor Transcriptional Programs.

    Science.gov (United States)

    Kutejova, Eva; Sasai, Noriaki; Shah, Ankita; Gouti, Mina; Briscoe, James

    2016-03-21

    In the vertebrate neural tube, a morphogen-induced transcriptional network produces multiple molecularly distinct progenitor domains, each generating different neuronal subtypes. Using an in vitro differentiation system, we defined gene expression signatures of distinct progenitor populations and identified direct gene-regulatory inputs corresponding to locations of specific transcription factor binding. Combined with targeted perturbations of the network, this revealed a mechanism in which a progenitor identity is installed by active repression of the entire transcriptional programs of other neural progenitor fates. In the ventral neural tube, sonic hedgehog (Shh) signaling, together with broadly expressed transcriptional activators, concurrently activates the gene expression programs of several domains. The specific outcome is selected by repressive input provided by Shh-induced transcription factors that act as the key nodes in the network, enabling progenitors to adopt a single definitive identity from several initially permitted options. Together, the data suggest design principles relevant to many developing tissues. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  4. Observational Investigations of the Progenitors of Supernovae

    Science.gov (United States)

    Lyman, J. D.

    2014-03-01

    Supernovae (SNe) are the spectacular deaths of stars and have shaped the universe we see today. Their far-reaching influence affects the chemical and dynamical evolution of galaxies, star formation, neutron star and black hole formation, and they are largely responsible for most of the heavy elements that make up the universe, including around 90 per cent of the reader. They also provide laboratories of nuclear and particle physics far beyond what we can construct on Earth and act as probes of extreme density and energy. This thesis presents new research into understanding the nature of the progenitor systems of various types of SNe, as well as presenting results that will allow their study to be more productive in the future, through use of automated pipelines and methods to increase the science value of discovered SNe. An environmental study of two peculiar types of transients ('Calcium-rich' and '2002cx-like'), which may not be true SNe, reveals extremely different ages of the exploding systems that will constrain the current theoretical effort into discovering the progenitor systems. The GRB-SN 120422A/2012bz is investigated and found to be an extremely luminous and energetic SN, even amongst the infamously bright GRB-SNe. A method is presented that allows an accurate reconstruction of the bolometric light curve of a core-collapse SN, which relies on only two optical filter observations - this will hugely reduce the observational cost of constructing bolometric light curves, a tool of great importance when hoping to constrain the nature of a SN explosion and hence its progenitor. Finally, this method is utilised to construct the largest bolometric CCSN bolometric light curve sample to date, and these are analytically modelled to reveal population statistics of the explosions, thus informing on the nature of the progenitors.

  5. Contrasting microsatellite diversity in the evolutionary lineages of Phytophthora lateralis.

    Science.gov (United States)

    Vettraino, AnnaMaria; Brasier, Clive M; Webber, Joan F; Hansen, Everett M; Green, Sarah; Robin, Cecile; Tomassini, Alessia; Bruni, Natalia; Vannini, Andrea

    2017-02-01

    Following recent discovery of Phytophthora lateralis on native Chamaecyparis obtusa in Taiwan, four phenotypically distinct lineages were discriminated: the Taiwan J (TWJ) and Taiwan K (TWK) in Taiwan, the Pacific Northwest (PNW) in North America and Europe and the UK in west Scotland. Across the four lineages, we analysed 88 isolates from multiple sites for microsatellite diversity. Twenty-one multilocus genotypes (MLGs) were resolved with high levels of diversity of the TWK and PNW lineages. No alleles were shared between the PNW and the Taiwanese lineages. TWK was heterozygous at three loci, whereas TWJ isolates were homozygous apart from one isolate, which exhibited a unique allele also present in the TWK lineage. PNW lineage was heterozygous at three loci. The evidence suggests its origin may be a yet unknown Asian source. North American and European PNW isolates shared all their alleles and also a dominant MLG, consistent with a previous proposal that this lineage is a recent introduction into Europe from North America. The UK lineage was monomorphic and homozygous at all loci. It shared its alleles with the PNW and the TWJ and TWK lineages, hence a possible origin in a recent hybridisation event between a Taiwan lineage and PNW cannot be ruled out. Copyright © 2016 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  6. Cytomegalovirus immune evasion of myeloid lineage cells.

    Science.gov (United States)

    Brinkmann, Melanie M; Dağ, Franziska; Hengel, Hartmut; Messerle, Martin; Kalinke, Ulrich; Čičin-Šain, Luka

    2015-06-01

    Cytomegalovirus (CMV) evades the immune system in many different ways, allowing the virus to grow and its progeny to spread in the face of an adverse environment. Mounting evidence about the antiviral role of myeloid immune cells has prompted the research of CMV immune evasion mechanisms targeting these cells. Several cells of the myeloid lineage, such as monocytes, dendritic cells and macrophages, play a role in viral control, but are also permissive for CMV and are naturally infected by it. Therefore, CMV evasion of myeloid cells involves mechanisms that qualitatively differ from the evasion of non-CMV-permissive immune cells of the lymphoid lineage. The evasion of myeloid cells includes effects in cis, where the virus modulates the immune signaling pathways within the infected myeloid cell, and those in trans, where the virus affects somatic cells targeted by cytokines released from myeloid cells. This review presents an overview of CMV strategies to modulate and evade the antiviral activity of myeloid cells in cis and in trans.

  7. Disaggregated Futures and Options Commitments of Traders

    Data.gov (United States)

    Commodity Futures Trading Commission — The Disaggregated Futures and Options Commitments of Traders dataset provides a breakdown of each week's open interest for agriculture, energy, metals, lumber, and...

  8. Family Commitment and Work Characteristics among Pharmacists.

    Science.gov (United States)

    Gubbins, Paul O; Ragland, Denise; Castleberry, Ashley N; Payakachat, Nalin

    2015-12-17

    Factors associated with family commitment among pharmacists in the south central U.S. are explored. In 2010, a cross-sectional mailed self-administered 70 item survey of 363 active licensed pharmacists was conducted. This analysis includes only 269 (74%) participants who reported being married. Outcome measures were family commitment (need for family commitment, spouse's family commitment), work-related characteristics (work challenge, stress, workload, flexibility of work schedule), and job and career satisfaction. Married participants' mean age was 48 (SD = 18) years; the male to female ratio was 1:1; 73% worked in retail settings and 199 (74%) completed the family commitment questions. Females reported a higher need for family commitment than males ( p = 0.02) but there was no significant difference in satisfaction with the commitment. Work challenge and work load were significantly associated with higher need for family commitment ( p work status, and practice setting. Higher work challenge was associated with higher career satisfaction. Higher job related stress was associated with lower job satisfaction. High work challenge and work load may negatively impact family function since married pharmacists would need higher family commitment from their counterparts. The impact of work-family interactions on pharmacy career satisfaction should be further investigated.

  9. Work engagement, organizational commitment, self efficacy and ...

    African Journals Online (AJOL)

    Information Impact: Journal of Information and Knowledge Management ... Work engagement, organizational commitment and self-efficacy will create a positive ... effective training, counseling, effective communication and leadership skills.

  10. Family Commitment and Work Characteristics among Pharmacists

    Directory of Open Access Journals (Sweden)

    Paul O. Gubbins

    2015-12-01

    Full Text Available Factors associated with family commitment among pharmacists in the south central U.S. are explored. In 2010, a cross-sectional mailed self-administered 70 item survey of 363 active licensed pharmacists was conducted. This analysis includes only 269 (74% participants who reported being married. Outcome measures were family commitment (need for family commitment, spouse’s family commitment, work-related characteristics (work challenge, stress, workload, flexibility of work schedule, and job and career satisfaction. Married participants’ mean age was 48 (SD = 18 years; the male to female ratio was 1:1; 73% worked in retail settings and 199 (74% completed the family commitment questions. Females reported a higher need for family commitment than males (p = 0.02 but there was no significant difference in satisfaction with the commitment. Work challenge and work load were significantly associated with higher need for family commitment (p < 0.01, when controlled for age, gender, number of dependents, work status, and practice setting. Higher work challenge was associated with higher career satisfaction. Higher job related stress was associated with lower job satisfaction. High work challenge and work load may negatively impact family function since married pharmacists would need higher family commitment from their counterparts. The impact of work-family interactions on pharmacy career satisfaction should be further investigated.

  11. Disaggregated Futures-Only Commitments of Traders

    Data.gov (United States)

    Commodity Futures Trading Commission — The Disaggregated Futures-Only Commitments of Traders dataset provides a breakdown of each week's open interest for agriculture, energy, metals, lumber, and...

  12. EVOLUTION OF PROGENITORS FOR ELECTRON CAPTURE SUPERNOVAE

    International Nuclear Information System (INIS)

    Takahashi, Koh; Umeda, Hideyuki; Yoshida, Takashi

    2013-01-01

    We provide progenitor models for electron capture supernovae (ECSNe) with detailed evolutionary calculation. We include minor electron capture nuclei using a large nuclear reaction network with updated reaction rates. For electron capture, the Coulomb correction of rates is treated and the contribution from neutron-rich isotopes is taken into account in each nuclear statistical equilibrium (NSE) composition. We calculate the evolution of the most massive super asymptotic giant branch stars and show that these stars undergo off-center carbon burning and form ONe cores at the center. These cores become heavier up to the critical mass of 1.367 M ☉ and keep contracting even after the initiation of O+Ne deflagration. Inclusion of minor electron capture nuclei causes convective URCA cooling during the contraction phase, but the effect on the progenitor evolution is small. On the other hand, electron capture by neutron-rich isotopes in the NSE region has a more significant effect. We discuss the uniqueness of the critical core mass for ECSNe and the effect of wind mass loss on the plausibility of our models for ECSN progenitors.

  13. All Hormone-Producing Cell Types of the Pituitary Intermediate and Anterior Lobes Derive From Prop1-Expressing Progenitors.

    Science.gov (United States)

    Davis, Shannon W; Keisler, Jessica L; Pérez-Millán, María I; Schade, Vanessa; Camper, Sally A

    2016-04-01

    Mutations in PROP1, the most common known cause of combined pituitary hormone deficiency in humans, can result in the progressive loss of all hormones of the pituitary anterior lobe. In mice, Prop1 mutations result in the failure to initiate transcription of Pou1f1 (also known as Pit1) and lack somatotropins, lactotropins, and thyrotropins. The basis for this species difference is unknown. We hypothesized that Prop1 is expressed in a progenitor cell that can develop into all anterior lobe cell types, and not just the somatotropes, thyrotropes, and lactotropes, which are collectively known as the PIT1 lineage. To test this idea, we produced a transgenic Prop1-cre mouse line and conducted lineage-tracing experiments of Prop1-expressing cells. The results reveal that all hormone-secreting cell types of both the anterior and intermediate lobes are descended from Prop1-expressing progenitors. The Prop1-cre mice also provide a valuable genetic reagent with a unique spatial and temporal expression for generating tissue-specific gene rearrangements early in pituitary gland development. We also determined that the minimal essential sequences for reliable Prop1 expression lie within 10 kilobases of the mouse gene and demonstrated that human PROP1 can substitute functionally for mouse Prop1. These studies enhance our understanding of the pathophysiology of disease in patients with PROP1 mutations.

  14. A single splice site mutation in human-specific ARHGAP11B causes basal progenitor amplification

    Science.gov (United States)

    Florio, Marta; Namba, Takashi; Pääbo, Svante; Hiller, Michael; Huttner, Wieland B.

    2016-01-01

    The gene ARHGAP11B promotes basal progenitor amplification and is implicated in neocortex expansion. It arose on the human evolutionary lineage by partial duplication of ARHGAP11A, which encodes a Rho guanosine triphosphatase–activating protein (RhoGAP). However, a lack of 55 nucleotides in ARHGAP11B mRNA leads to loss of RhoGAP activity by GAP domain truncation and addition of a human-specific carboxy-terminal amino acid sequence. We show that these 55 nucleotides are deleted by mRNA splicing due to a single C→G substitution that creates a novel splice donor site. We reconstructed an ancestral ARHGAP11B complementary DNA without this substitution. Ancestral ARHGAP11B exhibits RhoGAP activity but has no ability to increase basal progenitors during neocortex development. Hence, a single nucleotide substitution underlies the specific properties of ARHGAP11B that likely contributed to the evolutionary expansion of the human neocortex. PMID:27957544

  15. Feline Neural Progenitor Cells I: Long-Term Expansion under Defined Culture Conditions

    Directory of Open Access Journals (Sweden)

    Jing Yang

    2012-01-01

    Full Text Available Neural progenitor cells (NPCs of feline origin (cNPCs have demonstrated utility in transplantation experiments, yet are difficult to grow in culture beyond the 1 month time frame. Here we use an enriched, serum-free base medium (Ultraculture and report the successful long-term propagation of these cells. Primary cultures were derived from fetal brain tissue and passaged in DMEM/F12-based or Ultraculture-based proliferation media, both in the presence of EGF + bFGF. Cells in standard DMEM/F12-based medium ceased to proliferate by 1-month, whereas the cells in the Ultraculture-based medium continued to grow for at least 5 months (end of study with no evidence of senescence. The Ultraculture-based cultures expressed lower levels of progenitor and lineage-associated markers under proliferation conditions but retained multipotency as evidenced by the ability to differentiate into neurons and glia following growth factor removal in the presence of FBS. Importantly, later passage cNPCs did not develop chromosomal aberrations.

  16. Identification of Lgr5-Independent Spheroid-Generating Progenitors of the Mouse Fetal Intestinal Epithelium

    Directory of Open Access Journals (Sweden)

    Roxana C. Mustata

    2013-10-01

    Full Text Available Immortal spheroids were generated from fetal mouse intestine using the culture system initially developed to culture organoids from adult intestinal epithelium. Spheroid proportion progressively decreases from fetal to postnatal period, with a corresponding increase in production of organoids. Like organoids, spheroids show Wnt-dependent indefinite self-renewing properties but display a poorly differentiated phenotype reminiscent of incompletely caudalized progenitors. The spheroid transcriptome is strikingly different from that of adult intestinal stem cells, with minimal overlap of Wnt target gene expression. The receptor LGR4, but not LGR5, is essential for their growth. Trop2/Tacstd2 and Cnx43/Gja1, two markers highly enriched in spheroids, are expressed throughout the embryonic-day-14 intestinal epithelium. Comparison of in utero and neonatal lineage tracing using Cnx43-CreER and Lgr5-CreERT2 mice identified spheroid-generating cells as developmental progenitors involved in generation of the prenatal intestinal epithelium. Ex vivo, spheroid cells have the potential to differentiate into organoids, qualifying as a fetal type of intestinal stem cell.

  17. Recruitment of host's progenitor cells to sites of human amniotic fluid stem cells implantation.

    Science.gov (United States)

    Mirabella, Teodelinda; Poggi, Alessandro; Scaranari, Monica; Mogni, Massimo; Lituania, Mario; Baldo, Chiara; Cancedda, Ranieri; Gentili, Chiara

    2011-06-01

    The amniotic fluid is a new source of multipotent stem cells with a therapeutic potential for human diseases. Cultured at low cell density, human amniotic fluid stem cells (hAFSCs) were still able to generate colony-forming unit-fibroblast (CFU-F) after 60 doublings, thus confirming their staminal nature. Moreover, after extensive in vitro cell expansion hAFSCs maintained a stable karyotype. The expression of genes, such as SSEA-4, SOX2 and OCT3/4 was confirmed at early and later culture stage. Also, hAFSCs showed bright expression of mesenchymal lineage markers and immunoregulatory properties. hAFSCs, seeded onto hydroxyapatite scaffolds and subcutaneously implanted in nude mice, played a pivotal role in mounting a response resulting in the recruitment of host's progenitor cells forming tissues of mesodermal origin such as fat, muscle, fibrous tissue and immature bone. Implanted hAFSCs migrated from the scaffold to the skin overlying implant site but not to other organs. Given their in vivo: (i) recruitment of host progenitor cells, (ii) homing towards injured sites and (iii) multipotentiality in tissue repair, hAFSCs are a very appealing reserve of stem cells potentially useful for clinical application in regenerative medicine. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Long-Term Culture of Self-renewing Pancreatic Progenitors Derived from Human Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Jamie Trott

    2017-06-01

    Full Text Available Pluripotent stem cells have been proposed as an unlimited source of pancreatic β cells for studying and treating diabetes. However, the long, multi-step differentiation protocols used to generate functional β cells inevitably exhibit considerable variability, particularly when applied to pluripotent cells from diverse genetic backgrounds. We have developed culture conditions that support long-term self-renewal of human multipotent pancreatic progenitors, which are developmentally more proximal to the specialized cells of the adult pancreas. These cultured pancreatic progenitor (cPP cells express key pancreatic transcription factors, including PDX1 and SOX9, and exhibit transcriptomes closely related to their in vivo counterparts. Upon exposure to differentiation cues, cPP cells give rise to pancreatic endocrine, acinar, and ductal lineages, indicating multilineage potency. Furthermore, cPP cells generate insulin+ β-like cells in vitro and in vivo, suggesting that they offer a convenient alternative to pluripotent cells as a source of adult cell types for modeling pancreatic development and diabetes.

  19. Prolonged Expansion Induces Spontaneous Neural Progenitor Differentiation from Human Gingiva-Derived Mesenchymal Stem Cells.

    Science.gov (United States)

    Rajan, Thangavelu Soundara; Scionti, Domenico; Diomede, Francesca; Piattelli, Adriano; Bramanti, Placido; Mazzon, Emanuela; Trubiani, Oriana

    2017-12-01

    Neural crest-derived mesenchymal stem cells (MSCs) obtained from dental tissues received considerable interest in regenerative medicine, particularly in nerve regeneration owing to their embryonic origin and ease of harvest. Proliferation efficacy and differentiation capacity into diverse cell lineages propose dental MSCs as an in vitro tool for disease modeling. In this study, we investigated the spontaneous differentiation efficiency of dental MSCs obtained from human gingiva tissue (hGMSCs) into neural progenitor cells after extended passaging. At passage 41, the morphology of hGMSCs changed from typical fibroblast-like shape into sphere-shaped cells with extending processes. Next-generation transcriptomics sequencing showed increased expression of neural progenitor markers such as NES, MEIS2, and MEST. In addition, de novo expression of neural precursor genes, such as NRN1, PHOX2B, VANGL2, and NTRK3, was noticed in passage 41. Immunocytochemistry results showed suppression of neurogenesis repressors TP53 and p21, whereas Western blot results revealed the expression of neurotrophic factors BDNF and NT3 at passage 41. Our results showed the spontaneous efficacy of hGMSCs to differentiate into neural precursor cells over prolonged passages and that these cells may assist in producing novel in vitro disease models that are associated with neural development.

  20. Isolation and characterization of multipotent progenitor cells from the Bowman's capsule of adult human kidneys.

    Science.gov (United States)

    Sagrinati, Costanza; Netti, Giuseppe Stefano; Mazzinghi, Benedetta; Lazzeri, Elena; Liotta, Francesco; Frosali, Francesca; Ronconi, Elisa; Meini, Claudia; Gacci, Mauro; Squecco, Roberta; Carini, Marco; Gesualdo, Loreto; Francini, Fabio; Maggi, Enrico; Annunziato, Francesco; Lasagni, Laura; Serio, Mario; Romagnani, Sergio; Romagnani, Paola

    2006-09-01

    Regenerative medicine represents a critical clinical goal for patients with ESRD, but the identification of renal adult multipotent progenitor cells has remained elusive. It is demonstrated that in human adult kidneys, a subset of parietal epithelial cells (PEC) in the Bowman's capsule exhibit coexpression of the stem cell markers CD24 and CD133 and of the stem cell-specific transcription factors Oct-4 and BmI-1, in the absence of lineage-specific markers. This CD24+CD133+ PEC population, which could be purified from cultured capsulated glomeruli, revealed self-renewal potential and a high cloning efficiency. Under appropriate culture conditions, individual clones of CD24+CD133+ PEC could be induced to generate mature, functional, tubular cells with phenotypic features of proximal and/or distal tubules, osteogenic cells, adipocytes, and cells that exhibited phenotypic and functional features of neuronal cells. The injection of CD24+CD133+ PEC but not of CD24-CD133- renal cells into SCID mice that had acute renal failure resulted in the regeneration of tubular structures of different portions of the nephron. More important, treatment of acute renal failure with CD24+CD133+ PEC significantly ameliorated the morphologic and functional kidney damage. This study demonstrates the existence and provides the characterization of a population of resident multipotent progenitor cells in adult human glomeruli, potentially opening new avenues for the development of regenerative medicine in patients who have renal diseases.

  1. Committed, engaged e applied anthropology - Committed, engaged and applied anthropology

    Directory of Open Access Journals (Sweden)

    Antonio Luigi Palmisano

    2014-11-01

    Full Text Available Anthropology has become very popular over the past decades. We have witnessed a proliferation of anthropologists and anthropologies but the theoretical debate and the epistemological reflection of the discipline have come to a full stop. It seems that anthropology has reduced itself to a tekhne among many others, characterizing itself – according to the author – as «Atlantic anthropology», a protocolar anthropology in thrall to the dominating ideologies of the financial markets. The renewed discussion on the concepts of development and cooperation – concepts which have deeply marked the past three decades of social sciences and the current crystallization of anthropology – that is of contemporary economy, represents an opportunity to revivify and deepen the impact of anthropological theory. It is an epistemological and political impact with remarkable social and scientific consequences which is mostly detectable in one of the declinations of anthropology, i.e. applied anthropology, when and if intended as committed anthropology that founds its methodology and its way of being on fieldwork: a continuous dialogue with “alterity” in which the only thinkable “alienity” is represented by the tekhne and by the financial markets which support and promulgate it as omnipresent and almighty verbum.

  2. Collagen-Coated Polytetrafluoroethane Membrane Inserts Enhances Chondrogenic Differentiation of Human Cord Blood Multi-Lineage Progenitor Cells

    DEFF Research Database (Denmark)

    Munir, Samir; Søballe, Kjeld; Ulrich-Vinther, Michael

    culturing resulted in a multicellular layer tissue with formation of more cartilaginous tissue compared to micromass or CPP culture. In the membrane system MLPCs produced pellucid discs, 12 mm in diameter by 1 mm in thickness from 2x10^6 cells. The discs had hyaline-like cartilage extracellular matrix......Background: Articular chondrocytes and bone marrow-derived multipotent mesenchymal stromal cells (MSCs) are the favoured cells for cartilage tissue engineering. Umbilical cord blood has proven an alternative source of MSCs and moreover they may be more potent chondroprogenitor cells than bonemarrow...... with micromass or CPP cultures. Conclusions: In conclusion, we demonstrate that MLPCs possess’ chondrogenic potency, which increased when cultured scaffold-free on membrane inserts resulting in multicellular-layered hyaline-like cartilage tissue. Evaluating the effect of culturing pre-differentiated MLPCs on CPP...

  3. A scalable system for production of functional pancreatic progenitors from human embryonic stem cells.

    Directory of Open Access Journals (Sweden)

    Thomas C Schulz

    Full Text Available Development of a human embryonic stem cell (hESC-based therapy for type 1 diabetes will require the translation of proof-of-principle concepts into a scalable, controlled, and regulated cell manufacturing process. We have previously demonstrated that hESC can be directed to differentiate into pancreatic progenitors that mature into functional glucose-responsive, insulin-secreting cells in vivo. In this study we describe hESC expansion and banking methods and a suspension-based differentiation system, which together underpin an integrated scalable manufacturing process for producing pancreatic progenitors. This system has been optimized for the CyT49 cell line. Accordingly, qualified large-scale single-cell master and working cGMP cell banks of CyT49 have been generated to provide a virtually unlimited starting resource for manufacturing. Upon thaw from these banks, we expanded CyT49 for two weeks in an adherent culture format that achieves 50-100 fold expansion per week. Undifferentiated CyT49 were then aggregated into clusters in dynamic rotational suspension culture, followed by differentiation en masse for two weeks with a four-stage protocol. Numerous scaled differentiation runs generated reproducible and defined population compositions highly enriched for pancreatic cell lineages, as shown by examining mRNA expression at each stage of differentiation and flow cytometry of the final population. Islet-like tissue containing glucose-responsive, insulin-secreting cells was generated upon implantation into mice. By four- to five-months post-engraftment, mature neo-pancreatic tissue was sufficient to protect against streptozotocin (STZ-induced hyperglycemia. In summary, we have developed a tractable manufacturing process for the generation of functional pancreatic progenitors from hESC on a scale amenable to clinical entry.

  4. Tracking of adipose tissue-derived progenitor cells using two magnetic nanoparticle types

    Energy Technology Data Exchange (ETDEWEB)

    Kasten, Annika; Siegmund, Birte J. [Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, Rostock University Medical Center, Schillingallee 35 D-18057 Rostock (Germany); Grüttner, Cordula [Micromod Partikeltechnologie GmbH, Warnemünde, D-18115 Rostock (Germany); Kühn, Jens-Peter [Department of Radiology and Neuroradiology, Greifswald University Medical Center, D-17475 Greifswald (Germany); Frerich, Bernhard, E-mail: bernhard.frerich@med.uni-rostock.de [Department of Oral and Maxillofacial Surgery, Facial Plastic Surgery, Rostock University Medical Center, Schillingallee 35 D-18057 Rostock (Germany)

    2015-04-15

    Magnetic resonance imaging (MRI) is to be considered as an emerging detection technique for cell tracking experiments to evaluate the fate of transplanted progenitor cells and develop successful cell therapies for tissue engineering. Adipose tissue engineering using adipose tissue-derived progenitor cells has been advocated for the cure of soft tissue defects or for persistent soft tissue augmentation. Adipose tissue-derived progenitor cells were differentiated into the adipogenic lineage and labeled with two different types of magnetic iron oxide nanoparticles in varying concentrations which resulted in a concentration-dependent reduction of gene expression of adipogenic differentiation markers, adiponectin and fatty acid-binding protein 4 (FABP4), whereas the metabolic activity was not altered. As a result, only low nanoparticle concentrations for labeling were used for in vivo experiments. Cells were seeded onto collagen scaffolds and subcutaneously implanted into severe combined immunodeficient (SCID) mice. At 24 h as well as 28 days after implantation, MRI analyses were performed visualizing nanoparticle-labeled cells using T2-weighted sequences. The quantification of absolute volume of the scaffolds revealed a decrease of volume over time in all experimental groups. The distribution of nanoparticle-labeled cells within the scaffolds varied likewise over time. - Highlights: • Adipose tissue-derived stem cells (ASC) were labeled with magnetic iron oxide nanoparticles. • Nanoparticles influenced the adipogenic differentiation of ASC. • Labeled cells were seeded onto collagen scaffolds and implanted in SCID mice. • Nanoparticle-labeled cells were visualized in vivo using T2-weighted sequences. • Volume of collagen scaffolds was decreased over time after implantation.

  5. Tracking of adipose tissue-derived progenitor cells using two magnetic nanoparticle types

    International Nuclear Information System (INIS)

    Kasten, Annika; Siegmund, Birte J.; Grüttner, Cordula; Kühn, Jens-Peter; Frerich, Bernhard

    2015-01-01

    Magnetic resonance imaging (MRI) is to be considered as an emerging detection technique for cell tracking experiments to evaluate the fate of transplanted progenitor cells and develop successful cell therapies for tissue engineering. Adipose tissue engineering using adipose tissue-derived progenitor cells has been advocated for the cure of soft tissue defects or for persistent soft tissue augmentation. Adipose tissue-derived progenitor cells were differentiated into the adipogenic lineage and labeled with two different types of magnetic iron oxide nanoparticles in varying concentrations which resulted in a concentration-dependent reduction of gene expression of adipogenic differentiation markers, adiponectin and fatty acid-binding protein 4 (FABP4), whereas the metabolic activity was not altered. As a result, only low nanoparticle concentrations for labeling were used for in vivo experiments. Cells were seeded onto collagen scaffolds and subcutaneously implanted into severe combined immunodeficient (SCID) mice. At 24 h as well as 28 days after implantation, MRI analyses were performed visualizing nanoparticle-labeled cells using T2-weighted sequences. The quantification of absolute volume of the scaffolds revealed a decrease of volume over time in all experimental groups. The distribution of nanoparticle-labeled cells within the scaffolds varied likewise over time. - Highlights: • Adipose tissue-derived stem cells (ASC) were labeled with magnetic iron oxide nanoparticles. • Nanoparticles influenced the adipogenic differentiation of ASC. • Labeled cells were seeded onto collagen scaffolds and implanted in SCID mice. • Nanoparticle-labeled cells were visualized in vivo using T2-weighted sequences. • Volume of collagen scaffolds was decreased over time after implantation

  6. Lymphoid Progenitor Cells from Childhood Acute Lymphoblastic Leukemia Are Functionally Deficient and Express High Levels of the Transcriptional Repressor Gfi-1

    Directory of Open Access Journals (Sweden)

    Jessica Purizaca

    2013-01-01

    Full Text Available Acute lymphoblastic leukemia (ALL is the most frequent malignancy of childhood. Substantial progress on understanding the cell hierarchy within ALL bone marrow (BM has been recorded in the last few years, suggesting that both primitive cell fractions and committed lymphoid blasts with immature stem cell-like properties contain leukemia-initiating cells. Nevertheless, the biology of the early progenitors that initiate the lymphoid program remains elusive. The aim of the present study was to investigate the ability of lymphoid progenitors from B-cell precursor ALL BM to proliferate and undergo multilineage differentiation. By phenotype analyses, in vitro proliferation assays, and controlled culture systems, the lymphoid differentiation potentials were evaluated in BM primitive populations from B-cell precursor ALL pediatric patients. When compared to their normal counterparts, functional stem and progenitor cell contents were substantially reduced in ALL BM. Moreover, neither B nor NK or dendritic lymphoid-cell populations developed recurrently from highly purified ALL-lymphoid progenitors, and their proliferation and cell cycle status revealed limited proliferative capacity. Interestingly, a number of quiescence-associated transcription factors were elevated, including the transcriptional repressor Gfi-1, which was highly expressed in primitive CD34+ cells. Together, our findings reveal major functional defects in the primitive hematopoietic component of ALL BM. A possible contribution of high levels of Gfi-1 expression in the regulation of the stem/progenitor cell biology is suggested.

  7. Effects of Ethical Climate on Organizational Commitment, Professional Commitment, and Job Satisfaction of Auditor in Malaysia

    Directory of Open Access Journals (Sweden)

    Suhaiza Ismail

    2015-08-01

    Full Text Available The objective of this paper is to investigate the effect of the ethical climate on the organizational commitment, professional commitment and job satisfaction of Malaysian auditors. Using a survey questionnaire comprising instruments about the ethical climate, organizational commitment, professional commitment and job satisfaction, 263 usable responses were received. To achieve the objectives, mean scores, standard deviations, correlations and multiple regressions were performed. The study revealed that a significant positive influence of a caring ethical climate on professional and organizational commitment as well as job satisfaction existed. There was also a positive significant association between the law and code ethical climate and professional commitment. On the other hand, the study discovered that the instrumental ethical climate type had a significant negative relationship with organizational commitment and job satisfaction. A significant negative relationship was also revealed between the independent ethical climate type and organizational and professional commitment. A significant negative relationship between the rules ethical climate and job satisfaction was also discovered.

  8. Differentiation of retinal ganglion cells and photoreceptor precursors from mouse induced pluripotent stem cells carrying an Atoh7/Math5 lineage reporter.

    Directory of Open Access Journals (Sweden)

    Bin-Bin Xie

    Full Text Available The neural retina is a critical component of the visual system, which provides the majority of sensory input in humans. Various retinal degenerative diseases can result in the permanent loss of retinal neurons, especially the light-sensing photoreceptors and the centrally projecting retinal ganglion cells (RGCs. The replenishment of lost RGCs and the repair of optic nerve damage are particularly challenging, as both RGC specification and their subsequent axonal growth and projection involve complex and precise regulation. To explore the developmental potential of pluripotent stem cell-derived neural progenitors, we have established mouse iPS cells that allow cell lineage tracing of progenitors that have expressed Atoh7/Math5, a bHLH transcription factor required for RGC production. These Atoh7 lineage reporter iPS cells encode Cre to replace one copy of the endogenous Atoh7 gene and a Cre-dependent YFP reporter in the ROSA locus. In addition, they express pluripotent markers and are capable of generating teratomas in vivo. Under anterior neural induction and neurogenic conditions in vitro, the Atoh7-Cre/ROSA-YFP iPS cells differentiate into neurons that co-express various RGC markers and YFP, indicating that these neurons are derived from Atoh7-expressing progenitors. Consistent with previous in vivo cell lineage studies, the Atoh7-Cre/ROSA-YFP iPS cells also give rise to a subset of Crx-positive photoreceptor precursors. Furthermore, inhibition of Notch signaling in the iPSC cultures results in a significant increase of YFP-positive RGCs and photoreceptor precursors. Together, these results show that Atoh7-Cre/ROSA-YFP iPS cells can be used to monitor the development and survival of RGCs and photoreceptors from pluripotent stem cells.

  9. Putative oncogene Brachyury (T) is essential to specify cell fate but dispensable for notochord progenitor proliferation and EMT.

    Science.gov (United States)

    Zhu, Jianjian; Kwan, Kin Ming; Mackem, Susan

    2016-04-05

    The transcription factor Brachyury (T) gene is expressed throughout primary mesoderm (primitive streak and notochord) during early embryonic development and has been strongly implicated in the genesis of chordoma, a sarcoma of notochord cell origin. Additionally, T expression has been found in and proposed to play a role in promoting epithelial-mesenchymal transition (EMT) in various other types of human tumors. However, the role of T in normal mammalian notochord development and function is still not well-understood. We have generated an inducible knockdown model to efficiently and selectively deplete T from notochord in mouse embryos. In combination with genetic lineage tracing, we show that T function is essential for maintaining notochord cell fate and function. Progenitors adopt predominantly a neural fate in the absence of T, consistent with an origin from a common chordoneural progenitor. However, T function is dispensable for progenitor cell survival, proliferation, and EMT, which has implications for the therapeutic targeting of T in chordoma and other cancers.

  10. PlGF repairs myocardial ischemia through mechanisms of angiogenesis, cardioprotection and recruitment of myo-angiogenic competent marrow progenitors.

    Directory of Open Access Journals (Sweden)

    Hiroto Iwasaki

    Full Text Available Despite preclinical success in regenerating and revascularizing the infarcted heart using angiogenic growth factors or bone marrow (BM cells, recent clinical trials have revealed less benefit from these therapies than expected.We explored the therapeutic potential of myocardial gene therapy of placental growth factor (PlGF, a VEGF-related angiogenic growth factor, with progenitor-mobilizing activity.Myocardial PlGF gene therapy improves cardiac performance after myocardial infarction, by inducing cardiac repair and reparative myoangiogenesis, via upregulation of paracrine anti-apoptotic and angiogenic factors. In addition, PlGF therapy stimulated Sca-1(+/Lin(- (SL BM progenitor proliferation, enhanced their mobilization into peripheral blood, and promoted their recruitment into the peri-infarct borders. Moreover, PlGF enhanced endothelial progenitor colony formation of BM-derived SL cells, and induced a phenotypic switch of BM-SL cells, recruited in the infarct, to the endothelial, smooth muscle and cardiomyocyte lineage.Such pleiotropic effects of PlGF on cardiac repair and regeneration offer novel opportunities in the treatment of ischemic heart disease.

  11. Effects of Ethical Climate on Organizational Commitment, Professional Commitment, and Job Satisfaction of Auditor in Malaysia

    OpenAIRE

    Ismail, Suhaiza

    2015-01-01

    The objective of this paper is to investigate the effect of the ethical climate on the organizational commitment, professional commitment and job satisfaction of Malaysian auditors. Using a survey questionnaire comprising instruments about the ethical climate, organizational commitment, professional commitment and job satisfaction, 263 usable responses were received. To achieve the objectives, mean scores, standard deviations, correlations and multiple regressions were performed. The study re...

  12. Host-country policy – commitment or no-commitment: a theoretical analysis

    NARCIS (Netherlands)

    Mukherjee, A.

    2000-01-01

    This paper develops a model of foreign entry strategy and examines welfare of the host-country under two situations - (i) where host-country government commits to the tax policy, (ii) where host-country government does not commit to the tax policy. It turns out that under the non-committed

  13. Employee commitment and performance of manufacturing firms ...

    African Journals Online (AJOL)

    445) between job satisfaction and employee organizational commitment. Multiple regression revealed that pay and job promotion are the important elements that influence employee commitment. It is recommended that manufacturing organizations should emphasize pay and job promotion to enhance higher employee ...

  14. Making Commitments to Racial Justice Actionable

    Science.gov (United States)

    Diab, Rasha; Ferrel, Thomas; Godbee, Beth; Simpkins, Neil

    2013-01-01

    In this article, we articulate a framework for making our commitments to racial justice actionable, a framework that moves from narrating confessional accounts to articulating our commitments and then acting on them through both self-work and work-with-others, a dialectic possibility we identify and explore. We model a method for moving beyond…

  15. Sexually Violent Predators and Civil Commitment Laws

    Science.gov (United States)

    Beyer Kendall, Wanda D.; Cheung, Monit

    2004-01-01

    This article analyzes the civil commitment models for treating sexually violent predators (SVPs) and analyzes recent civil commitment laws. SVPs are commonly defined as sex offenders who are particularly predatory and repetitive in their sexually violent behavior. Data from policy literature, a survey to all states, and a review of law review…

  16. Understanding the Links between Work Commitment Constructs.

    Science.gov (United States)

    Hackett, Rick D.; Lapierre, Laurent M.; Hausdorf, Peter A.

    2001-01-01

    In a study of 852 nurses, work involvement (value of work in their lives) affected organizational and occupational commitment through its effect on job involvement. Job involvement indirectly affected intention to leave the organization or occupation. Work and job involvement and orgnanizational and occupational commitment were determined to be…

  17. 7 CFR 3550.70 - Conditional commitments.

    Science.gov (United States)

    2010-01-01

    ..., dealer-contractor, or seller must: (1) Have an adequate ownership interest in the property, as defined in... approval of an affirmative marketing plan. (b) Limitations. Conditional commitments for new or... as bad weather, materials shortages, or marketing difficulties. Conditional commitments may be...

  18. The Influence of Culture on Teacher Commitment

    Science.gov (United States)

    Abd Razak, Nordin; Darmawan, I. Gusti Ngurah; Keeves, John P.

    2010-01-01

    Culture is believed to be an important factor that influences various aspects of human life, such as behaviour, thinking, perceptions and attitudes. This article examines the similarities and differences in the influence of culture on teacher commitment in three types of Malaysian primary schools. Since commitment to teaching has rarely been…

  19. On Entry Deterrence and Imperfectly Observable Commitment

    DEFF Research Database (Denmark)

    Poulsen, Anders

    2001-01-01

    We analyse a simple entry-deterrence game, where a `Potential Intruder' only imperfectly observes the decision of an `Incumbent' to commit or to not commit to fight any entry by the Potential Intruder. Our game generalises the one studied in Bonanno (1992) by allowing for a richer information tec...

  20. Juvenile Court Commitment Rates: The National Picture.

    Science.gov (United States)

    Sosin, Michael

    There is less geographic variation in the commitment rate of juvenile offenders than is commonly assumed. Apparently, judges across the country develop a similar standard of what percentage of youths they face should be committed. This standard may be similar across the country because it represents broadly shared ideals. However, there is much…

  1. Education on the Internet: Anonymity vs. Commitment.

    Science.gov (United States)

    Dreyfus, Hubert L.

    1998-01-01

    Argues that learning a skill requires the kind of commitment which is undermined by the Press (the Public) and the Internet, citing Soren Kierkegaard's "The Present Age", and states that learning by apprenticeship is impossible in cyberspace. Includes: aesthetic sphere--commitment to the enjoyment of sheer information; ethical…

  2. The Behavioral Expression of Organizational Commitment.

    Science.gov (United States)

    Randall, Donna M.; And Others

    1990-01-01

    Explored within empirical study context complexity of organizational commitment construct and respondent-generated behavioral manifestations of job attitude among plant workers (N=156). Found each commitment dimension related differently to work outcomes and that none of the dimensions was able to predict absenteeism or tardiness. (Author/CM)

  3. The Thoc1 encoded ribonucleoprotein is required for myeloid progenitor cell homeostasis in the adult mouse.

    Science.gov (United States)

    Pitzonka, Laura; Ullas, Sumana; Chinnam, Meenalakshmi; Povinelli, Benjamin J; Fisher, Daniel T; Golding, Michelle; Appenheimer, Michelle M; Nemeth, Michael J; Evans, Sharon; Goodrich, David W

    2014-01-01

    Co-transcriptionally assembled ribonucleoprotein (RNP) complexes are critical for RNA processing and nuclear export. RNPs have been hypothesized to contribute to the regulation of coordinated gene expression, and defects in RNP biogenesis contribute to genome instability and disease. Despite the large number of RNPs and the importance of the molecular processes they mediate, the requirements for individual RNP complexes in mammalian development and tissue homeostasis are not well characterized. THO is an evolutionarily conserved, nuclear RNP complex that physically links nascent transcripts with the nuclear export apparatus. THO is essential for early mouse embryonic development, limiting characterization of the requirements for THO in adult tissues. To address this shortcoming, a mouse strain has been generated allowing inducible deletion of the Thoc1 gene which encodes an essential protein subunit of THO. Bone marrow reconstitution was used to generate mice in which Thoc1 deletion could be induced specifically in the hematopoietic system. We find that granulocyte macrophage progenitors have a cell autonomous requirement for Thoc1 to maintain cell growth and viability. Lymphoid lineages are not detectably affected by Thoc1 loss under the homeostatic conditions tested. Myeloid lineages may be more sensitive to Thoc1 loss due to their relatively high rate of proliferation and turnover.

  4. The Thoc1 encoded ribonucleoprotein is required for myeloid progenitor cell homeostasis in the adult mouse.

    Directory of Open Access Journals (Sweden)

    Laura Pitzonka

    Full Text Available Co-transcriptionally assembled ribonucleoprotein (RNP complexes are critical for RNA processing and nuclear export. RNPs have been hypothesized to contribute to the regulation of coordinated gene expression, and defects in RNP biogenesis contribute to genome instability and disease. Despite the large number of RNPs and the importance of the molecular processes they mediate, the requirements for individual RNP complexes in mammalian development and tissue homeostasis are not well characterized. THO is an evolutionarily conserved, nuclear RNP complex that physically links nascent transcripts with the nuclear export apparatus. THO is essential for early mouse embryonic development, limiting characterization of the requirements for THO in adult tissues. To address this shortcoming, a mouse strain has been generated allowing inducible deletion of the Thoc1 gene which encodes an essential protein subunit of THO. Bone marrow reconstitution was used to generate mice in which Thoc1 deletion could be induced specifically in the hematopoietic system. We find that granulocyte macrophage progenitors have a cell autonomous requirement for Thoc1 to maintain cell growth and viability. Lymphoid lineages are not detectably affected by Thoc1 loss under the homeostatic conditions tested. Myeloid lineages may be more sensitive to Thoc1 loss due to their relatively high rate of proliferation and turnover.

  5. Definitive hematopoietic stem/progenitor cells manifest distinct differentiation output in the zebrafish VDA and PBI.

    Science.gov (United States)

    Jin, Hao; Sood, Raman; Xu, Jin; Zhen, Fenghua; English, Milton A; Liu, P Paul; Wen, Zilong

    2009-02-01

    One unique feature of vertebrate definitive hematopoiesis is the ontogenic switching of hematopoietic stem cells from one anatomical compartment or niche to another. In mice, hematopoietic stem cells are believed to originate in the aorta-gonad-mesonephros (AGM), subsequently migrate to the fetal liver (FL) and finally colonize the bone marrow (BM). Yet, the differentiation potential of hematopoietic stem cells within early niches such as the AGM and FL remains incompletely defined. Here, we present in vivo analysis to delineate the differentiation potential of definitive hematopoietic stem/progenitor cells (HSPCs) in the zebrafish AGM and FL analogies, namely the ventral wall of dorsal aorta (VDA) and the posterior blood island (PBI), respectively. Cell fate mapping and analysis of zebrafish runx1(w84x) and vlad tepes (vlt(m651)) mutants revealed that HSPCs in the PBI gave rise to both erythroid and myeloid lineages. However, we surprisingly found that HSPCs in the VDA were not quiescent but were uniquely adapted to generate myeloid but not erythroid lineage cells. We further showed that such distinct differentiation output of HSPCs was, at least in part, ascribed to the different micro-environments present in these two niches. Our results highlight the importance of niche in shaping the differentiation output of developing HSPCs.

  6. Human Cardiac Progenitor Spheroids Exhibit Enhanced Engraftment Potential.

    Directory of Open Access Journals (Sweden)

    Francesca Oltolina

    Full Text Available A major obstacle to an effective myocardium stem cell therapy has always been the delivery and survival of implanted stem cells in the heart. Better engraftment can be achieved if cells are administered as cell aggregates, which maintain their extra-cellular matrix (ECM. We have generated spheroid aggregates in less than 24 h by seeding human cardiac progenitor cells (hCPCs onto methylcellulose hydrogel-coated microwells. Cells within spheroids maintained the expression of stemness/mesenchymal and ECM markers, growth factors and their cognate receptors, cardiac commitment factors, and metalloproteases, as detected by immunofluorescence, q-RT-PCR and immunoarray, and expressed a higher, but regulated, telomerase activity. Compared to cells in monolayers, 3D spheroids secreted also bFGF and showed MMP2 activity. When spheroids were seeded on culture plates, the cells quickly migrated, displaying an increased wound healing ability with or without pharmacological modulation, and reached confluence at a higher rate than cells from conventional monolayers. When spheroids were injected in the heart wall of healthy mice, some cells migrated from the spheroids, engrafted, and remained detectable for at least 1 week after transplantation, while, when the same amount of cells was injected as suspension, no cells were detectable three days after injection. Cells from spheroids displayed the same engraftment capability when they were injected in cardiotoxin-injured myocardium. Our study shows that spherical in vivo ready-to-implant scaffold-less aggregates of hCPCs able to engraft also in the hostile environment of an injured myocardium can be produced with an economic, easy and fast protocol.

  7. Organizational culture and organizational commitment: Serbian case

    Directory of Open Access Journals (Sweden)

    Mitić Siniša

    2016-01-01

    Full Text Available The paper presents the results of the impact of certain dimensions of organizational culture (Future Orientation, Power Distance, Human Orientation and Performance Orientation on organizational commitment in companies in Serbia. Through a survey, responses were obtained from a total of N = 400 middle managers from 129 companies. The results show a statistically significant correlation between the observed dimensions of organizational culture and organizational commitment dimensions. Also, there is a statistically significant predictive effect of certain dimensions of organizational culture on the dimensions of organizational commitment. The biggest influences on the dimensions of organizational commitment have dimensions Future Orientation - FO and Performance Orientation - PO. On the other hand, under the most affected dimension of organizational culture is the dimension of organizational commitment Organizational identification - OCM1.

  8. Protein profile of basal prostate epithelial progenitor cells--stage-specific embryonal antigen 4 expressing cells have enhanced regenerative potential in vivo.

    Science.gov (United States)

    Höfner, Thomas; Klein, Corinna; Eisen, Christian; Rigo-Watermeier, Teresa; Haferkamp, Axel; Sprick, Martin R

    2016-04-01

    The long-term propagation of basal prostate progenitor cells ex vivo has been very difficult in the past. The development of novel methods to expand prostate progenitor cells in vitro allows determining their cell surface phenotype in greater detail. Mouse (Lin(-)Sca-1(+) CD49f(+) Trop2(high)-phenotype) and human (Lin(-) CD49f(+) TROP2(high)) basal prostate progenitor cells were expanded in vitro. Human and mouse cells were screened using 242 anti-human or 176 antimouse monoclonal antibodies recognizing the cell surface protein profile. Quantitative expression was evaluated at the single-cell level using flow cytometry. Differentially expressed cell surface proteins were evaluated in conjunction with the known CD49f(+)/TROP2(high) phenotype of basal prostate progenitor cells and characterized by in vivo sandwich-transplantation experiments using nude mice. The phenotype of basal prostate progenitor cells was determined as CD9(+)/CD24(+)/CD29(+)/CD44(+)/CD47(+)/CD49f(+)/CD104(+)/CD147(+)/CD326(+)/Trop2(high) of mouse as well as human origin. Our analysis revealed several proteins, such as CD13, Syndecan-1 and stage-specific embryonal antigens (SSEAs), as being differentially expressed on murine and human CD49f(+) TROP2(+) basal prostate progenitor cells. Transplantation experiments suggest that CD49f(+) TROP2(high) SSEA-4(high) human prostate basal progenitor cells to be more potent to regenerate prostate tubules in vivo as compared with CD49f(+) TROP2(high) or CD49f(+) TROP2(high) SSEA-4(low) cells. Determination of the cell surface protein profile of functionally defined murine and human basal prostate progenitor cells reveals differentially expressed proteins that may change the potency and regenerative function of epithelial progenitor cells within the prostate. SSEA-4 is a candidate cell surface marker that putatively enables a more accurate identification of the basal PESC lineage. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by

  9. Intraocular Injection of ES Cell-Derived Neural Progenitors Improve Visual Function in Retinal Ganglion Cell-Depleted Mouse Models

    Directory of Open Access Journals (Sweden)

    Mundackal S. Divya

    2017-09-01

    Full Text Available Retinal ganglion cell (RGC transplantation is a promising strategy to restore visual function resulting from irreversible RGC degeneration occurring in glaucoma or inherited optic neuropathies. We previously demonstrated FGF2 induced differentiation of mouse embryonic stem cells (ESC to RGC lineage, capable of retinal ganglion cell layer (GCL integration upon transplantation. Here, we evaluated possible improvement of visual function by transplantation of ES cell derived neural progenitors in RGC depleted glaucoma mice models. ESC derived neural progenitors (ES-NP were transplanted into N-Methyl-D-Aspartate (NMDA injected, RGC-ablated mouse models and a pre-clinical glaucoma mouse model (DBA/2J having sustained higher intra ocular pressure (IOP. Visual acuity and functional integration was evaluated by behavioral experiments and immunohistochemistry, respectively. GFP-expressing ES-NPs transplanted in NMDA-injected RGC-depleted mice differentiated into RGC lineage and possibly integrating into GCL. An improvement in visual acuity was observed after 2 months of transplantation, when compared to the pre-transplantation values. Expression of c-Fos in the transplanted cells, upon light induction, further suggests functional integration into the host retinal circuitry. However, the transplanted cells did not send axonal projections into optic nerve. Transplantation experiments in DBA/2J mouse showed no significant improvement in visual functions, possibly due to both host and transplanted retinal cell death which could be due to an inherent high IOP. We showed that, ES NPs transplanted into the retina of RGC-ablated mouse models could survive, differentiate to RGC lineage, and possibly integrate into GCL to improve visual function. However, for the survival of transplanted cells in glaucoma, strategies to control the IOP are warranted.

  10. Yolk sac mesenchymal progenitor cells from New World mice (Necromys lasiurus with multipotent differential potential.

    Directory of Open Access Journals (Sweden)

    Phelipe Oliveira Favaron

    Full Text Available Fetal membranes are abundant, ethically acceptable and readily accessible sources of stem cells. In particular, the yolk sac is a source of cell lineages that do not express MHCs and are mainly free from immunological incompatibles when transferred to a recipient. Although data are available especially for hematopoietic stem cells in mice and human, whereas other cell types and species are dramatically underrepresented. Here we studied the nature and differentiation potential of yolk sac derived mesenchymal stem cells from a New World mouse, Necromys lasiurus. Explants from mid-gestation were cultured in DMEM-High glucose medium with 10% defined fetal bovine serum. The cells were characterized by standard methods including immunophenotyping by fluorescence and flow cytometry, growth and differentiation potential and tumorigenicity assays. The first adherent cells were observed after 7 days of cell culture and included small, elongated fibroblast-like cells (92.13% and large, round epithelial-like cells with centrally located nuclei (6.5%. Only the fibroblast-like cells survived the first passages. They were positive to markers for mesenchymal stem cells (Stro-1, CD90, CD105, CD73 and pluripotency (Oct3/4, Nanog as well as precursors of hematopoietic stem cells (CD117. In differentiation assays, they were classified as a multipotent lineage, because they differentiated into osteogenic, adipogenic, and chondrogenic lineages and, finally, they did not develop tumors. In conclusion, mesenchymal progenitor cells with multipotent differentiation potential and sufficient growth and proliferation abilities were able to be obtained from Necromys yolk sacs, therefore, we inferred that these cells may be promising for a wide range of applications in regenerative medicine.

  11. Blastema from rabbit ear contains progenitor cells comparable to marrow derived mesenchymal stem cells

    Directory of Open Access Journals (Sweden)

    Mohamadreza Baghaban Eslaminejad

    2012-09-01

    Full Text Available Rabbits have the capacity to regenerate holes in their ears by forming a blastema, a tissue that is made up of a group of undifferentiated cells. The purpose of the present study was to isolate and characterize blastema progenitor cells and compare them with marrow mesenchymal stem cells (MSCs. Five New Zealand white male rabbits were used in the present study. A 2-mm hole was created in the animal ears. After 4 days, the blastema ring formed in the periphery of the hole was removed and cultivated. The cells were expanded through several subcultures and compared with the MSCs derived from the marrow of same animal in terms of in vitro differentiation capacity, growth kinetics and culture requirements for optimal proliferation. The primary cultures from both cells tended to be heterogeneous. Fibroblastic cells became progressively dominant with advancing passages. Similar to MSCs blastema passaged-3 cells succeeded to differentiate into bone, cartilage and adipose cell lineages. Even lineage specific genes tended to express in higher level in blastema cells compared to MSCs (p < 0.05. Moreover blastema cells appeared more proliferative; producing more colonies (p < 0.05. While blastema cells showed extensive proliferation in 15% fetal bovine serum (FBS, MSCs displayed higher expansion rate at 10% FBS. In conclusion, blastema from rabbit ear contains a population of fibroblastic cells much similar in characteristic to bone marrow mesenchymal stem cells. However, the two cells were different in the level of lineage-specific gene expression, the growth curve characteristics and the culture requirements.

  12. Heparan Sulfate Proteoglycans as Drivers of Neural Progenitors Derived From Human Mesenchymal Stem Cells.

    Science.gov (United States)

    Okolicsanyi, Rachel K; Oikari, Lotta E; Yu, Chieh; Griffiths, Lyn R; Haupt, Larisa M

    2018-01-01

    Background: Due to their relative ease of isolation and their high ex vivo and in vitro expansive potential, human mesenchymal stem cells (hMSCs) are an attractive candidate for therapeutic applications in the treatment of brain injury and neurological diseases. Heparan sulfate proteoglycans (HSPGs) are a family of ubiquitous proteins involved in a number of vital cellular processes including proliferation and stem cell lineage differentiation. Methods: Following the determination that hMSCs maintain neural potential throughout extended in vitro expansion, we examined the role of HSPGs in mediating the neural potential of hMSCs. hMSCs cultured in basal conditions (undifferentiated monolayer cultures) were found to co-express neural markers and HSPGs throughout expansion with modulation of the in vitro niche through the addition of exogenous HS influencing cellular HSPG and neural marker expression. Results: Conversion of hMSCs into hMSC Induced Neurospheres (hMSC IN) identified distinctly localized HSPG staining within the spheres along with altered gene expression of HSPG core protein and biosynthetic enzymes when compared to undifferentiated hMSCs. Conclusion: Comparison of markers of pluripotency, neural self-renewal and neural lineage specification between hMSC IN, hMSC and human neural stem cell (hNSC H9) cultures suggest that in vitro generated hMSC IN may represent an intermediary neurogenic cell type, similar to a common neural progenitor cell. In addition, this data demonstrates HSPGs and their biosynthesis machinery, are associated with hMSC IN formation. The identification of specific HSPGs driving hMSC lineage-specification will likely provide new markers to allow better use of hMSCs in therapeutic applications and improve our understanding of human neurogenesis.

  13. Early de novo DNA methylation and prolonged demethylation in the muscle lineage.

    Science.gov (United States)

    Tsumagari, Koji; Baribault, Carl; Terragni, Jolyon; Varley, Katherine E; Gertz, Jason; Pradhan, Sirharsa; Badoo, Melody; Crain, Charlene M; Song, Lingyun; Crawford, Gregory E; Myers, Richard M; Lacey, Michelle; Ehrlich, Melanie

    2013-03-01

    Myogenic cell cultures derived from muscle biopsies are excellent models for human cell differentiation. We report the first comprehensive analysis of myogenesis-specific DNA hyper- and hypo-methylation throughout the genome for human muscle progenitor cells (both myoblasts and myotubes) and skeletal muscle tissue vs. 30 non-muscle samples using reduced representation bisulfite sequencing. We also focused on four genes with extensive hyper- or hypo-methylation in the muscle lineage (PAX3, TBX1, MYH7B/MIR499 and OBSCN) to compare DNA methylation, DNaseI hypersensitivity, histone modification, and CTCF binding profiles. We found that myogenic hypermethylation was strongly associated with homeobox or T-box genes and muscle hypomethylation with contractile fiber genes. Nonetheless, there was no simple relationship between differential gene expression and myogenic differential methylation, rather only for subsets of these genes, such as contractile fiber genes. Skeletal muscle retained ~30% of the hypomethylated sites but only ~3% of hypermethylated sites seen in myogenic progenitor cells. By enzymatic assays, skeletal muscle was 2-fold enriched globally in genomic 5-hydroxymethylcytosine (5-hmC) vs. myoblasts or myotubes and was the only sample type enriched in 5-hmC at tested myogenic hypermethylated sites in PAX3/CCDC140 andTBX1. TET1 and TET2 RNAs, which are involved in generation of 5-hmC and DNA demethylation, were strongly upregulated in myoblasts and myotubes. Our findings implicate de novo methylation predominantly before the myoblast stage and demethylation before and after the myotube stage in control of transcription and co-transcriptional RNA processing. They also suggest that, in muscle, TET1 or TET2 are involved in active demethylation and in formation of stable 5-hmC residues.

  14. To the Large Nucleolar Bodies in Apoptotic Leukaemic Granulocytic Progenitors without Further Differentiation. Are Large Nucleoli Always Present in Proliferating Cells?

    Science.gov (United States)

    Smetana, K; Kuželová, K; Zápotocký, M; Hrkal, Z

    2017-01-01

    Large nucleoli have generally been believed to be present in less differentiated and proliferating cells including the malignant ones. Such nucleoli have also been considered to be active in the biosynthetic process and major cell developmental activities. In contrast, after cytostatic treatment, apoptotic leukaemic progenitors still containing nuclei did not exhibit substantial reduction of the nucleolar size but displayed decreased nucleolar biosynthetic activity. The present study was undertaken to provide more information on the large nucleoli in spontaneously occurring apoptotic leukaemic progenitors without further differentiation. Leukaemic progenitors of established cell lineages originating from leukaemic patients represented a very convenient model for such study. Some of them exhibit morphological signs of the spontaneously occurring apoptotic process. Since such signs are expressed by nuclear and cytoplasmic morphological variability, the present study dealt with spontaneously occurring apoptotic progenitors with preserved nuclei characterized by heavy chromatin condensation and occasional fragmentation. Based of nucleolar body and nuclear maximal diameter measurements it seems to be clear that the nucleolar size in these cells was not substantially reduced, contrary to that of the nucleus. However, large nucleolar bodies in spontaneously occurring apoptotic cells were characterized by markedly reduced biosynthetic activity, as expressed by the decreased number of nucleolar transcription markers such as nucleolar fibrillar centres. In conclusion, large nucleoli may be present not only in proliferating, but also in spontaneously occurring apoptotic cells.

  15. Identification of a progenitor cell population destined to form fracture fibrocartilage callus in Dickkopf-related protein 3-green fluorescent protein reporter mice.

    Science.gov (United States)

    Mori, Yu; Adams, Douglas; Hagiwara, Yusuke; Yoshida, Ryu; Kamimura, Masayuki; Itoi, Eiji; Rowe, David W

    2016-11-01

    Fracture healing is a complex biological process involving the proliferation of mesenchymal progenitor cells, and chondrogenic, osteogenic, and angiogenic differentiation. The mechanisms underlying the proliferation and differentiation of mesenchymal progenitor cells remain unclear. Here, we demonstrate Dickkopf-related protein 3 (Dkk3) expression in periosteal cells using Dkk3-green fluorescent protein reporter mice. We found that proliferation of mesenchymal progenitor cells began in the periosteum, involving Dkk3-positive cell proliferation near the fracture site. In addition, Dkk3 was expressed in fibrocartilage cells together with smooth muscle α-actin and Col3.6 in the early phase of fracture healing as a cell marker of fibrocartilage cells. Dkk3 was not expressed in mature chondrogenic cells or osteogenic cells. Transient expression of Dkk3 disappeared in the late phase of fracture healing, except in the superficial periosteal area of fracture callus. The Dkk3 expression pattern differed in newly formed type IV collagen positive blood vessels and the related avascular tissue. This is the first report that shows Dkk3 expression in the periosteum at a resting state and in fibrocartilage cells during the fracture healing process, which was associated with smooth muscle α-actin and Col3.6 expression in mesenchymal progenitor cells. These fluorescent mesenchymal lineage cells may be useful for future studies to better understand fracture healing.

  16. The Impact of Trust on Organization Commitment

    Science.gov (United States)

    Robinson, Kimberly; Stinson, Thomas N. (Technical Monitor)

    2002-01-01

    As the global economy continues to spawn competitive forces, organizations have sought to become more competitive by cutting costs, eliminating non-value added work, and using more automation. Jobs have become broader and more flexible leading to a leaner workforce with higher-level knowledge and skills and more responsibility for day-to-day decisions. More than ever, organizations depend on employees as the innovators and designers of products and processes and as a source of strategic advantage. Therefore employee commitment among knowledge workers is needed to maintain organizational viability. It would seem that stronger relationships due to greater dependency, involvement, and investment would develop between employers and high-technology workers resulting in more committed employees. However, the opposite has been evidenced as key knowledge workers are changing jobs frequently. This may be due to a perceived lack of commitment by management to its employees. The notion of exchange may dominate the development of organizational commitment whereby an individual decides what to give a firm (commitment, extra effort, better performance, etc.) based on what the firm gives them (e.g., trust and security). It is the relationship between an employee's organizational commitment and the responding level of trust in the organization that is examined in this paper. An experiment is described that will seek to identify this relationship. Preliminary results are expected to show a positive relationship whereby employee commitment is positively correlated with organizational trust.

  17. The complexity of the calretinin-expressing progenitors in the human cerebral cortex

    Directory of Open Access Journals (Sweden)

    Nevena V Radonjic

    2014-08-01

    Full Text Available The complex structure and function of the cerebral cortex critically depend on the balance of excitation and inhibition provided by the pyramidal projection neurons and GABAergic interneurons, respectively. The calretinin-expressing (CalR+ cell is a subtype of GABAergic cortical interneurons that is more prevalent in humans than in rodents. In rodents, CalR+ interneurons originate in the caudal ganglionic eminence (CGE from Gsx2+ progenitors, but in humans it has been suggested that a subpopulation of CalR+ cells can also be generated in the cortical ventricular/subventricular zone (VZ/SVZ. The progenitors for cortically generated CalR+ subpopulation in primates are not yet characterized. Hence, the aim of this study was to identify patterns of expression of the transcription factors (TFs that commit cortical stem cells to the CalR fate, with a focus on Gsx2. First, we studied the expression of Gsx2 and its downstream effectors, Ascl1 and Sp8 in the cortical regions of the fetal human forebrain at midgestation. Next, we established that a subpopulation of cells expressing these TFs are proliferating in the cortical SVZ, and can be co-labeled with CalR. The presence and proliferation of Gsx2+ cells, not only in the ventral telencephalon (GE as previously reported, but also in the cerebral cortex suggests cortical origin of a subpopulation of CalR+ neurons in humans. In vitro treatment of human cortical progenitors with Sonic hedgehog (Shh, an important morphogen in the specification of interneurons, decreased levels of Ascl1 and Sp8 proteins, but did not affect Gsx2 levels. Taken together, our ex-vivo and in vitro results on human fetal brain suggest complex endogenous and exogenous regulation of TFs implied in the specification of different subtypes of CalR+ cortical interneurons.

  18. Transplantation of human embryonic stem cell-derived oligodendrocyte progenitors into rat spinal cord injuries does not cause harm.

    Science.gov (United States)

    Cloutier, Frank; Siegenthaler, Monica M; Nistor, Gabriel; Keirstead, Hans S

    2006-07-01

    Demyelination contributes to loss of function following spinal cord injury. We have shown previously that transplantation of human embryonic stem cell-derived oligodendrocyte progenitors into adult rat 200 kD contusive spinal cord injury sites enhances remyelination and promotes recovery of motor function. Previous studies using oligodendrocyte lineage cells have noted a correlation between the presence of demyelinating pathology and the survival and migration rate of the transplanted cells. The present study compared the survival and migration of human embryonic stem cell-derived oligodendrocyte progenitors injected 7 days after a 200 or 50 kD contusive spinal cord injury, as well as the locomotor outcome of transplantation. Our findings indicate that a 200 kD spinal cord injury induces extensive demyelination, whereas a 50 kD spinal cord injury induces no detectable demyelination. Cells transplanted into the 200 kD injury group survived, migrated, and resulted in robust remyelination, replicating our previous studies. In contrast, cells transplanted into the 50 kD injury group survived, exhibited limited migration, and failed to induce remyelination as demyelination in this injury group was absent. Animals that received a 50 kD injury displayed only a transient decline in locomotor function as a result of the injury. Importantly, human embryonic stem cell-derived oligodendrocyte progenitor transplants into the 50 kD injury group did not cause a further decline in locomotion. Our studies highlight the importance of a demyelinating pathology as a prerequisite for the function of transplanted myelinogenic cells. In addition, our results indicate that transplantation of human embryonic stem cell-derived oligodendrocyte progenitor cells into the injured spinal cord is not associated with a decline in locomotor function.

  19. Escalation of Commitment in the Surgical ICU.

    Science.gov (United States)

    Braxton, Carla C; Robinson, Celia N; Awad, Samir S

    2017-04-01

    Escalation of commitment is a business term that describes the continued investment of resources into a project even after there is objective evidence of the project's impending failure. Escalation of commitment may be a contributor to high healthcare costs associated with critically ill patients as it has been shown that, despite almost certain futility, most ICU costs are incurred in the last week of life. Our objective was to determine if escalation of commitment occurs in healthcare settings, specifically in the surgical ICU. We hypothesize that factors previously identified in business and organizational psychology literature including self-justification, accountability, sunk costs, and cognitive dissonance result in escalation of commitment behavior in the surgical ICU setting resulting in increased utilization of resources and cost. A descriptive case study that illustrates common ICU narratives in which escalation of commitment can occur. In addition, we describe factors that are thought to contribute to escalation of commitment behaviors. Escalation of commitment behavior was observed with self-justification, accountability, and cognitive dissonance accounting for the majority of the behavior. Unlike in business decisions, sunk costs was not as evident. In addition, modulating factors such as personality, individual experience, culture, and gender were identified as contributors to escalation of commitment. Escalation of commitment occurs in the surgical ICU, resulting in significant expenditure of resources despite a predicted and often known poor outcome. Recognition of this phenomenon may lead to actions aimed at more rational decision making and may contribute to lowering healthcare costs. Investigation of objective measures that can help aid decision making in the surgical ICU is warranted.

  20. Notch signaling activation in human embryonic stem cells is required for embryonic but not trophoblastic lineage commitment

    OpenAIRE

    Yu, Xiaobing; Zou, Jizhong; Ye, Zhaohui; Hammond, Holly; Chen, Guibin; Tokunaga, Akinori; Mali, Prashant; Li, Yue-Ming; Civin, Curt; Gaiano, Nicholas; Cheng, Linzhao

    2008-01-01

    The Notch signaling pathway plays important roles in cell fate determination during embryonic development and adult life. In this study, we focus on the role of Notch signaling in governing cell fate choices in human embryonic stem (hES) cells. Using genetic and pharmacological approaches, we achieved both blockade and conditional activation of Notch signaling in several hES cell lines. We report here that activation of Notch signaling is required for undifferentiated hES cells to form the pr...

  1. Probing altered hematopoietic progenitors of preleukemic dogs with JANUS fission neutrons

    International Nuclear Information System (INIS)

    Seed, T.M.; Kaspar, L.V.

    1990-01-01

    Toward the goal of developing basic insights to mechanisms of radiation leukemogenesis, the authors have developed a canine model that responds to protracted courses of low-daily-dose gamma irradiation with high incidences of myeloproliferative disease (MPD), principally myeloid leukemia. Using this model system, the authors have identified and partially characterized a four-phase preclinical sequence in the induction of MPD, including (1) suppression, (2) recovery, (3) accommodation, and (4) preleukemic transition. Further, they have identified within this sequence, a critical early hematopoietic target cell event that appears to promote progression of the initial preclinical phase to the second preclinical phase. This key target cell event is characterized by the acquisition of increased radioresistance to low-LET gamma rays by granulocyte/monocyte-committed progenitors (CFU-GM). In order to gain further insight into the basis of this critical event, the acquired survival responses of preleukemic progenitors have been probed in vitro with high-LET fission neutrons. 23 refs., 4 figs., 1 tab

  2. Macrophage/epithelium cross-talk regulates cell cycle progression and migration in pancreatic progenitors.

    Directory of Open Access Journals (Sweden)

    Kristin Mussar

    Full Text Available Macrophages populate the mesenchymal compartment of all organs during embryogenesis and have been shown to support tissue organogenesis and regeneration by regulating remodeling of the extracellular microenvironment. Whether this mesenchymal component can also dictate select developmental decisions in epithelia is unknown. Here, using the embryonic pancreatic epithelium as model system, we show that macrophages drive the epithelium to execute two developmentally important choices, i.e. the exit from cell cycle and the acquisition of a migratory phenotype. We demonstrate that these developmental decisions are effectively imparted by macrophages activated toward an M2 fetal-like functional state, and involve modulation of the adhesion receptor NCAM and an uncommon "paired-less" isoform of the transcription factor PAX6 in the epithelium. Over-expression of this PAX6 variant in pancreatic epithelia controls both cell motility and cell cycle progression in a gene-dosage dependent fashion. Importantly, induction of these phenotypes in embryonic pancreatic transplants by M2 macrophages in vivo is associated with an increased frequency of endocrine-committed cells emerging from ductal progenitor pools. These results identify M2 macrophages as key effectors capable of coordinating epithelial cell cycle withdrawal and cell migration, two events critical to pancreatic progenitors' delamination and progression toward their differentiated fates.

  3. Macrophage/epithelium cross-talk regulates cell cycle progression and migration in pancreatic progenitors.

    Science.gov (United States)

    Mussar, Kristin; Tucker, Andrew; McLennan, Linsey; Gearhart, Addie; Jimenez-Caliani, Antonio J; Cirulli, Vincenzo; Crisa, Laura

    2014-01-01

    Macrophages populate the mesenchymal compartment of all organs during embryogenesis and have been shown to support tissue organogenesis and regeneration by regulating remodeling of the extracellular microenvironment. Whether this mesenchymal component can also dictate select developmental decisions in epithelia is unknown. Here, using the embryonic pancreatic epithelium as model system, we show that macrophages drive the epithelium to execute two developmentally important choices, i.e. the exit from cell cycle and the acquisition of a migratory phenotype. We demonstrate that these developmental decisions are effectively imparted by macrophages activated toward an M2 fetal-like functional state, and involve modulation of the adhesion receptor NCAM and an uncommon "paired-less" isoform of the transcription factor PAX6 in the epithelium. Over-expression of this PAX6 variant in pancreatic epithelia controls both cell motility and cell cycle progression in a gene-dosage dependent fashion. Importantly, induction of these phenotypes in embryonic pancreatic transplants by M2 macrophages in vivo is associated with an increased frequency of endocrine-committed cells emerging from ductal progenitor pools. These results identify M2 macrophages as key effectors capable of coordinating epithelial cell cycle withdrawal and cell migration, two events critical to pancreatic progenitors' delamination and progression toward their differentiated fates.

  4. [Differences on geographic distribution of rabies virus lineages in China].

    Science.gov (United States)

    Wang, Q; Li, M L; Chen, Y; Wang, B; Tao, X Y; Zhu, W Y

    2018-04-10

    Objective: To study the lineages of rabies virus and the epidemic characteristics in different provincial populations of China, to provide information for the development of control and prevention measures in each respective provinces. Methods: Full length N and G genes and full-genome of epidemic strains of rabies virus collected in China were downloaded from GenBank and combined with newly sequenced strains by our lab. Each strain was classified under six lineages of China rabies by constructing phylogenetic trees based on the N or G sequences. Numbers of strains and lineages in each province were counted and compared. Results: Six lineages (China Ⅰ-Ⅵ) were prevalent in China, with 4 found in Yunnan and Hunan. In 6 provinces, including Henan and Fujian, 3 lineages were found. In 8 provinces, including Shanghai and Jiangxi, 2 lineages were found Only 1 lineage, were found in Beijing, Tianjin and other 12 provinces. the China Ⅰ, was the dominant one in 25 provinces. In recent years, China Ⅲ had been found in wild animals and spread over livestock in Inner Mongolia and Xinjiang areas. Qinghai and Tibet had been influenced by China Ⅳ, which also been found in wild animals of Inner Mongolia and Heilongjiang. Conclusion: There had been obvious differences in lineages and strain numbers of rabies virus identified in different provinces in China.

  5. Evidence of multiple divergent mitochondrial lineages within the ...

    African Journals Online (AJOL)

    On this basis, the mitochondrial cytochrome c oxidase subunit 1 (COI) was used to reconstruct the phylogeny of Bicoxidens and reveal divergent lineages within the genus. Maximum likelihood and Bayesian inference analyses recovered a paraphyletic Bicoxidens phylogram with divergent lineages present in three species ...

  6. A defined, feeder-free, serum-free system to generate in vitro hematopoietic progenitors and differentiated blood cells from hESCs and hiPSCs.

    Directory of Open Access Journals (Sweden)

    Giorgia Salvagiotto

    2011-03-01

    Full Text Available Human ESC and iPSC are an attractive source of cells of high quantity and purity to be used to elucidate early human development processes, for drug discovery, and in clinical cell therapy applications. To efficiently differentiate pluripotent cells into a pure population of hematopoietic progenitors we have developed a new 2-dimensional, defined and highly efficient protocol that avoids the use of feeder cells, serum or embryoid body formation. Here we showed that a single matrix protein in combination with growth factors and a hypoxic environment is sufficient to generate from pluripotent cells hematopoietic progenitors capable of differentiating further in mature cell types of different lineages of the blood system. We tested the differentiation method using hESCs and 9 iPSC lines generated from different tissues. These data indicate the robustness of the protocol providing a valuable tool for the generation of clinical-grade hematopoietic cells from pluripotent cells.

  7. Syncrude's commitment to Aboriginal development

    International Nuclear Information System (INIS)

    Loader, R. K.

    1999-01-01

    Syncrude's program designed to maintain good relations with Aboriginal communities in all areas where Syncrude operation impact upon Aboriginal peoples and their traditional ways of life are described. The program extends from employment through education to business and community development, the preservation of traditional lifestyles, and the protection of the environment. As examples, some 13 per cent of Syncrude's workforce is made up of Aboriginal people, at an average annual salary of $58,000. The company offers $ 2,000 each, specifically to Aboriginal persons, wanting to further their education particularly in disciplines related to oil sands. A five-year $ 500,000 program has been established by Syncrude at the University of Alberta specifically for Aboriginal people to pursue careers in engineering, medicine , education and business. Other career programs are also offered through Keyano College, Athabasca University and the Northern Alberta Development Council, and there is a strong commitment by the company to encouraging adults to go back to school and for kids to stay in school. Last year the company spent $ 54 million with Aboriginal-owned and operated businesses; the company also support several programs to foster the appreciation of Aboriginal culture not only in Alberta but throughout the country. Environment is the fifth and final element of the Aboriginal Development Program. It involves consultation and working with local communities on environmental matters involving issues ranging from land reclamation to emission reduction. Some six million dollars are spent annually on reclaiming land and reintroducing native animal and plant species wherever possible. An outstanding example of this is the Wood Bison Trail on 210 hectares of reclaimed land managed by the Fort McKay First Nations. It is readily acknowledged that dealing with Aboriginal concerns has not been an easy road to travel and that there are still many things to do. Nevertheless, there

  8. Collective dose commitments from nuclear power programmes

    International Nuclear Information System (INIS)

    Beninson, D.

    1977-01-01

    The concepts of collective dose and collective dose commitment are discussed, particularly regarding their use to compare the relative importance of the exposure from several radiation sources and to predict future annual doses from a continuing practice. The collective dose commitment contributions from occupational exposure and population exposure due to the different components of the nuclear power fuel cycle are evaluated. A special discussion is devoted to exposures delivered over a very long time by released radionuclides of long half-lives and to the use of the incomplete collective dose commitment. The maximum future annual ''per caput'' doses from present and projected nuclear power programmes are estimated

  9. Notch lineages and activity in intestinal stem cells determined by a new set of knock-in mice.

    Directory of Open Access Journals (Sweden)

    Silvia Fre

    Full Text Available The conserved role of Notch signaling in controlling intestinal cell fate specification and homeostasis has been extensively studied. Nevertheless, the precise identity of the cells in which Notch signaling is active and the role of different Notch receptor paralogues in the intestine remain ambiguous, due to the lack of reliable tools to investigate Notch expression and function in vivo. We generated a new series of transgenic mice that allowed us, by lineage analysis, to formally prove that Notch1 and Notch2 are specifically expressed in crypt stem cells. In addition, a novel Notch reporter mouse, Hes1-EmGFP(SAT, demonstrated exclusive Notch activity in crypt stem cells and absorptive progenitors. This roster of knock-in and reporter mice represents a valuable resource to functionally explore the Notch pathway in vivo in virtually all tissues.

  10. Low bone mass and changes in the osteocyte network in mice lacking autophagy in the osteoblast lineage.

    Science.gov (United States)

    Piemontese, Marilina; Onal, Melda; Xiong, Jinhu; Han, Li; Thostenson, Jeff D; Almeida, Maria; O'Brien, Charles A

    2016-04-11

    Autophagy maintains cell function and homeostasis by recycling intracellular components. This process is also required for morphological changes associated with maturation of some cell types. Osteoblasts are bone forming cells some of which become embedded in bone and differentiate into osteocytes. This transformation includes development of long cellular projections and a reduction in endoplasmic reticulum and mitochondria. We examined the role of autophagy in osteoblasts by deleting Atg7 using an Osterix1-Cre transgene, which causes recombination in osteoblast progenitors and their descendants. Mice lacking Atg7 in the entire osteoblast lineage had low bone mass and fractures associated with reduced numbers of osteoclasts and osteoblasts. Suppression of autophagy also reduced the amount of osteocyte cellular projections and led to retention of endoplasmic reticulum and mitochondria in osteocytes. These results demonstrate that autophagy in osteoblasts contributes to skeletal homeostasis and to the morphological changes associated with osteocyte formation.

  11. Retinal progenitor cell xenografts to the pig retina

    DEFF Research Database (Denmark)

    Warfvinge, Karin; Kiilgaard, Jens Folke; Lavik, Erin B

    2005-01-01

    To investigate the survival, integration, and differentiation of mouse retinal progenitor cells after transplantation to the subretinal space of adult pigs.......To investigate the survival, integration, and differentiation of mouse retinal progenitor cells after transplantation to the subretinal space of adult pigs....

  12. Ihh signaling is directly required for the osteoblast lineage in the endochondral skeleton.

    Science.gov (United States)

    Long, Fanxin; Chung, Ung-il; Ohba, Shinsuke; McMahon, Jill; Kronenberg, Henry M; McMahon, Andrew P

    2004-03-01

    Indian hedgehog (Ihh) is indispensable for development of the osteoblast lineage in the endochondral skeleton. In order to determine whether Ihh is directly required for osteoblast differentiation, we have genetically manipulated smoothened (Smo), which encodes a transmembrane protein that is essential for transducing all Hedgehog (Hh) signals. Removal of Smo from perichondrial cells by the Cre-LoxP approach prevents formation of a normal bone collar and also abolishes development of the primary spongiosa. Analysis of chimeric embryos composed of wild-type and Smo(n/n) cells indicates that Smo(n/n) cells fail to contribute to osteoblasts in either the bone collar or the primary spongiosa but generate ectopic chondrocytes. In order to assess whether Ihh is sufficient to induce bone formation in vivo, we have analyzed the bone collar in the long bones of embryos in which Ihh was artificially expressed in all chondrocytes by the UAS-GAL4 bigenic system. Although ectopic Ihh does not induce overt ossification along the entire cartilage anlage, it promotes progression of the bone collar toward the epiphysis, suggesting a synergistic effect between ectopic Ihh and endogenous factors such as the bone morphogenetic proteins (BMPs). In keeping with this model, Hh signaling is further found to be required in BMP-induced osteogenesis in cultures of a limb-bud cell line. Taken together, these results demonstrate that Ihh signaling is directly required for the osteoblast lineage in the developing long bones and that Ihh functions in conjunction with other factors such as BMPs to induce osteoblast differentiation. We suggest that Ihh acts in vivo on a potential progenitor cell to promote osteoblast and prevent chondrocyte differentiation.

  13. Notch-mediated post-translational control of Ngn3 protein stability regulates pancreatic patterning and cell fate commitment

    DEFF Research Database (Denmark)

    Qu, Xiaoling; Afelik, Solomon; Jensen, Jan Nygaard

    2013-01-01

    of ducts. On one hand, Ngn3 cell-intrinsically activates endocrine target genes; on the other, Ngn3 cell-extrinsically promotes lateral signaling via the Dll1>Notch>Hes1 pathway which substantially limits its ability to sustain endocrine formation. Prior to endocrine commitment, the Ngn3-mediated...... involves transcriptional repression as previously shown, but also incorporates a novel post-translational mechanism. In addition to its ability to promote endocrine fate, we provide evidence of a competing ability of Ngn3 in the patterning of multipotent progenitor cells in turn controlling the formation...

  14. OP9-Lhx2 stromal cells facilitate derivation of hematopoietic progenitors both in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Xiaoli Chen

    2015-09-01

    Full Text Available Generating engraftable hematopoietic stem cells (HSCs from pluripotent stem cells (PSCs is an ideal approach for obtaining induced HSCs for cell therapy. However, the path from PSCs to robustly induced HSCs (iHSCs in vitro remains elusive. We hypothesize that the modification of hematopoietic niche cells by transcription factors facilitates the derivation of induced HSCs from PSCs. The Lhx2 transcription factor is expressed in fetal liver stromal cells but not in fetal blood cells. Knocking out Lhx2 leads to a fetal hematopoietic defect in a cell non-autonomous role. In this study, we demonstrate that the ectopic expression of Lhx2 in OP9 cells (OP9-Lhx2 accelerates the hematopoietic differentiation of PSCs. OP9-Lhx2 significantly increased the yields of hematopoietic progenitor cells via co-culture with PSCs in vitro. Interestingly, the co-injection of OP9-Lhx2 and PSCs into immune deficient mice also increased the proportion of hematopoietic progenitors via the formation of teratomas. The transplantation of phenotypic HSCs from OP9-Lhx2 teratomas but not from the OP9 control supported a transient repopulating capability. The upregulation of Apln gene by Lhx2 is correlated to the hematopoietic commitment property of OP9-Lhx2. Furthermore, the enforced expression of Apln in OP9 cells significantly increased the hematopoietic differentiation of PSCs. These results indicate that OP9-Lhx2 is a good cell line for regeneration of hematopoietic progenitors both in vitro and in vivo.

  15. Selective uptake of boronophenylalanine by glioma stem/progenitor cells

    International Nuclear Information System (INIS)

    Sun, Ting; Zhou, Youxin; Xie, Xueshun; Chen, Guilin; Li, Bin; Wei, Yongxin; Chen, Jinming; Huang, Qiang; Du, Ziwei

    2012-01-01

    The success of boron neutron capture therapy (BNCT) depends on the amount of boron in cells and the tumor/blood and tumor/(normal tissue) boron concentration ratios. For the first time, measurements of boron uptake in both stem/progenitor and differentiated glioma cells were performed along with measurements of boron biodistribution in suitable animal models. In glioma stem/progenitor cells, the selective accumulation of boronophenylalanine (BPA) was lower, and retention of boron after BPA removal was longer than in differentiated glioma cells in vitro. However, boron biodistribution was not statistically significantly different in mice with xenografts. - Highlights: ► Uptake of BPA was analyzed in stem/progenitor and differentiated glioma cells. ► Selective accumulation of BPA was lower in glioma stem/progenitor cells. ► Retention of boron after BPA removal was longer in glioma stem/progenitor cells. ► Boron biodistribution was not statistically different in mice with xenografts.

  16. Ecotype diversification of an abundant Roseobacter lineage.

    Science.gov (United States)

    Sun, Ying; Zhang, Yao; Hollibaugh, James T; Luo, Haiwei

    2017-04-01

    The Roseobacter DC5-80-3 cluster (also known as the RCA clade) is among the most abundant bacterial lineages in temperate and polar oceans. Previous studies revealed two phylotypes within this cluster that are distinctly distributed in the Antarctic and other ocean provinces. Here, we report a nearly complete genome co-assembly of three closely related single cells co-occurring in the Antarctic, and compare it to the available genomes of the other phylotype from ocean regions where iron is more accessible but phosphorus and nitrogen are less. The Antarctic phylotype exclusively contains an operon structure consisting of a dicitrate transporter fecBCDE and an upstream regulator likely for iron uptake, whereas the other phylotype consistently carry a high-affinity phosphate pst transporter and the phoB-phoR regulatory system, a high-affinity ammonium amtB transporter, urea and taurine utilization systems. Moreover, the Antarctic phylotype uses proteorhodopsin to acquire light, whereas the other uses bacteriochlorophyll-a and the sulfur-oxidizing sox cluster for energy acquisition. This is potentially an iron-saving strategy for the Antarctic phylotype because only the latter two pathways have iron-requiring cytochromes. Therefore, the two DC5-80-3 phylotypes, while diverging by only 1.1% in their 16S rRNA genes, have evolved systematic differences in metabolism to support their distinct ecologies. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  17. Origin, lineage and function of cerebellar glia.

    Science.gov (United States)

    Buffo, Annalisa; Rossi, Ferdinando

    2013-10-01

    The glial cells of the cerebellum, and particularly astrocytes and oligodendrocytes, are characterized by a remarkable phenotypic variety, in which highly peculiar morphological features are associated with specific functional features, unique among the glial cells of the entire CNS. Here, we provide a critical report about the present knowledge of the development of cerebellar glia, including lineage relationships between cerebellar neurons, astrocytes and oligodendrocytes, the origins and the genesis of the repertoire of glial types, and the processes underlying their acquisition of mature morphological and functional traits. In parallel, we describe and discuss some fundamental roles played by specific categories of glial cells during cerebellar development. In particular, we propose that Bergmann glia exerts a crucial scaffolding activity that, together with the organizing function of Purkinje cells, is necessary to achieve the normal pattern of foliation and layering of the cerebellar cortex. Moreover, we discuss some of the functional tasks of cerebellar astrocytes and oligodendrocytes that are distinctive of cerebellar glia throughout the CNS. Notably, we report about the regulation of synaptic signalling in the molecular and granular layer mediated by Bergmann glia and parenchymal astrocytes, and the functional interaction between oligodendrocyte precursor cells and neurons. On the whole, this review provides an extensive overview of the available literature and some novel insights about the origin and differentiation of the variety of cerebellar glial cells and their function in the developing and mature cerebellum. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Cell lineage identification and stem cell culture in a porcine model for the study of intestinal epithelial regeneration.

    Directory of Open Access Journals (Sweden)

    Liara M Gonzalez

    Full Text Available Significant advances in intestinal stem cell biology have been made in murine models; however, anatomical and physiological differences between mice and humans limit mice as a translational model for stem cell based research. The pig has been an effective translational model, and represents a candidate species to study intestinal epithelial stem cell (IESC driven regeneration. The lack of validated reagents and epithelial culture methods is an obstacle to investigating IESC driven regeneration in a pig model. In this study, antibodies against Epithelial Adhesion Molecule 1 (EpCAM and Villin marked cells of epithelial origin. Antibodies against Proliferative Cell Nuclear Antigen (PCNA, Minichromosome Maintenance Complex 2 (MCM2, Bromodeoxyuridine (BrdU and phosphorylated Histone H3 (pH3 distinguished proliferating cells at various stages of the cell cycle. SOX9, localized to the stem/progenitor cells zone, while HOPX was restricted to the +4/'reserve' stem cell zone. Immunostaining also identified major differentiated lineages. Goblet cells were identified by Mucin 2 (MUC2; enteroendocrine cells by Chromogranin A (CGA, Gastrin and Somatostatin; and absorptive enterocytes by carbonic anhydrase II (CAII and sucrase isomaltase (SIM. Transmission electron microscopy demonstrated morphologic and sub-cellular characteristics of stem cell and differentiated intestinal epithelial cell types. Quantitative PCR gene expression analysis enabled identification of stem/progenitor cells, post mitotic cell lineages, and important growth and differentiation pathways. Additionally, a method for long-term culture of porcine crypts was developed. Biomarker characterization and development of IESC culture in the porcine model represents a foundation for translational studies of IESC-driven regeneration of the intestinal epithelium in physiology and disease.

  19. Green Suppliers Network Supply Chain Commitment Form

    Science.gov (United States)

    Online form to show your company desires to be a Green Suppliers Network supply chain. Expresses an intent to: commit to engage at least five suppliers to complete an assessment process within a 12-month period and more.

  20. Organisational commitment and responses to planned ...

    African Journals Online (AJOL)

    Southern African Business Review Volume 15 Number 3 2011 ... This type of change is said to address surface-level issues and avoids threats to deep- .... instrumentality, and commitment to the organisation based on moral attachment by.

  1. Identification of Determinants of Organizational Commitment and ...

    African Journals Online (AJOL)

    commitment. In this setting, factors such as the loyalty employees feel are based on a .... Organizational structure characteristics like size span of control, .... working environment (ii) Tools and equipment (iii) Working methods (iv) Security.

  2. JOB ANXIETY, ORGANIZATIONAL COMMITMENT AND JOB ...

    African Journals Online (AJOL)

    and work experience with job satisfaction. ... were more likely to perceive the appraisal as unfair and inappropriate (Desai and ... Working freedom, salary and fringe benefits are the major factors ..... Men, women and attitudinal commitment:.

  3. Work Engagement, Organizational Commitment, Self Efficacy and ...

    African Journals Online (AJOL)

    Work engagement, organizational commitment and self-efficacy will create a positive attitude in records ... counseling, effective communication and leadership skills. This study therefore ...... self-efficacy and self-esteem: Toward theoretical and ...

  4. Organisational Commitment, Job Satisfaction and Turnover ...

    African Journals Online (AJOL)

    This study investigated organisational commitment, job satisfaction and turnover intentions among records management personnel in Ondo State Civil Service, Akure, Nigeria. Simple random sampling technique was used to draw 240 subjects from a population size of 275 records management personnel.

  5. Gauging the Commitment of Clandestine Group Members

    National Research Council Canada - National Science Library

    Downs, Doneda D

    2006-01-01

    .... Until a few years ago, most research on individual commitment and organizational cohesion has been based primarily on questionnaires and open observations on groups that desire to be understood...

  6. Third age university, social and institucional commitment

    Directory of Open Access Journals (Sweden)

    Flora Moritz da Silva

    2017-12-01

    Full Text Available This article brings reflections on the social commitment of permanent education programs for the elderly, at the universities, in the face of their institutional commitment to the plans. It was possible to rescue the responsibility concepts, social commitment and identify the elderly in the university, within the federal legislation, through bibliographical and documentary research. There was a survey of permanent education programs with at least 20 years, in 2016. It was carried out for the elderly in the 63 Brazilian Federal, and Public Universities and 17 cases were found. Thus, nine Pro-Rectors of Extension and a Unit Director accepted to participate in interviews by Skype or telephone, in the second semester of 2016, fulfilling the objective of describing the university authorities’ vision on the type of institutional support for such programs’ operation. Although it is possible to realize their relevance to the environment and the university, the institutional commitment is still far short of what is necessary.

  7. EGF–FGF{sub 2} stimulates the proliferation and improves the neuronal commitment of mouse epidermal neural crest stem cells (EPI-NCSCs)

    Energy Technology Data Exchange (ETDEWEB)

    Bressan, Raul Bardini; Melo, Fernanda Rosene; Almeida, Patricia Alves; Bittencourt, Denise Avani; Visoni, Silvia; Jeremias, Talita Silva [Departamento de Biologia Celular, Embriologia e Genética, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Campus Universitário – Trindade, 88040-900 Florianópolis SC (Brazil); Costa, Ana Paula; Leal, Rodrigo Bainy [Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Campus Universitário – Trindade, 88040-900 Florianópolis SC (Brazil); Trentin, Andrea Gonçalves, E-mail: andrea.trentin@ufsc.br [Departamento de Biologia Celular, Embriologia e Genética, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Campus Universitário – Trindade, 88040-900 Florianópolis SC (Brazil)

    2014-09-10

    Epidermal neural crest stem cells (EPI-NCSCs), which reside in the bulge of hair follicles, are attractive candidates for several applications in cell therapy, drug screening and tissue engineering. As suggested remnants of the embryonic neural crest (NC) in an adult location, EPI-NCSCs are able to generate a wide variety of cell types and are readily accessible by a minimally invasive procedure. Since the combination of epidermal growth factor (EGF) and fibroblast growth factor type 2 (FGF{sub 2}) is mitogenic and promotes the neuronal commitment of various stem cell populations, we examined its effects in the proliferation and neuronal potential of mouse EPI-NCSCs. By using a recognized culture protocol of bulge whiskers follicles, we were able to isolate a population of EPI-NCSCs, characterized by the migratory potential, cell morphology and expression of phenotypic markers of NC cells. EPI-NCSCs expressed neuronal, glial and smooth muscle markers and exhibited the NC-like fibroblastic morphology. The treatment with the combination EGF and FGF{sub 2}, however, increased their proliferation rate and promoted the acquisition of a neuronal-like morphology accompanied by reorganization of neural cytoskeletal proteins βIII-tubulin and nestin, as well as upregulation of the pan neuronal marker βIII-tubulin and down regulation of the undifferentiated NC, glial and smooth muscle cell markers. Moreover, the treatment enhanced the response of EPI-NCSCs to neurogenic stimulation, as evidenced by induction of GAP43, and increased expression of Mash-1 in neuron-like cell, both neuronal-specific proteins. Together, the results suggest that the combination of EGF–FGF2 stimulates the proliferation and improves the neuronal potential of EPI-NCSCs similarly to embryonic NC cells, ES cells and neural progenitor/stem cells of the central nervous system and highlights the advantage of using EGF–FGF{sub 2} in neuronal differentiation protocols. - Highlights: • EPI

  8. EGF–FGF2 stimulates the proliferation and improves the neuronal commitment of mouse epidermal neural crest stem cells (EPI-NCSCs)

    International Nuclear Information System (INIS)

    Bressan, Raul Bardini; Melo, Fernanda Rosene; Almeida, Patricia Alves; Bittencourt, Denise Avani; Visoni, Silvia; Jeremias, Talita Silva; Costa, Ana Paula; Leal, Rodrigo Bainy; Trentin, Andrea Gonçalves

    2014-01-01

    Epidermal neural crest stem cells (EPI-NCSCs), which reside in the bulge of hair follicles, are attractive candidates for several applications in cell therapy, drug screening and tissue engineering. As suggested remnants of the embryonic neural crest (NC) in an adult location, EPI-NCSCs are able to generate a wide variety of cell types and are readily accessible by a minimally invasive procedure. Since the combination of epidermal growth factor (EGF) and fibroblast growth factor type 2 (FGF 2 ) is mitogenic and promotes the neuronal commitment of various stem cell populations, we examined its effects in the proliferation and neuronal potential of mouse EPI-NCSCs. By using a recognized culture protocol of bulge whiskers follicles, we were able to isolate a population of EPI-NCSCs, characterized by the migratory potential, cell morphology and expression of phenotypic markers of NC cells. EPI-NCSCs expressed neuronal, glial and smooth muscle markers and exhibited the NC-like fibroblastic morphology. The treatment with the combination EGF and FGF 2 , however, increased their proliferation rate and promoted the acquisition of a neuronal-like morphology accompanied by reorganization of neural cytoskeletal proteins βIII-tubulin and nestin, as well as upregulation of the pan neuronal marker βIII-tubulin and down regulation of the undifferentiated NC, glial and smooth muscle cell markers. Moreover, the treatment enhanced the response of EPI-NCSCs to neurogenic stimulation, as evidenced by induction of GAP43, and increased expression of Mash-1 in neuron-like cell, both neuronal-specific proteins. Together, the results suggest that the combination of EGF–FGF2 stimulates the proliferation and improves the neuronal potential of EPI-NCSCs similarly to embryonic NC cells, ES cells and neural progenitor/stem cells of the central nervous system and highlights the advantage of using EGF–FGF 2 in neuronal differentiation protocols. - Highlights: • EPI-NCSCs express

  9. Impairment of circulating endothelial progenitors in Down syndrome

    Directory of Open Access Journals (Sweden)

    Costa Valerio

    2010-09-01

    Full Text Available Abstract Background Pathological angiogenesis represents a critical issue in the progression of many diseases. Down syndrome is postulated to be a systemic anti-angiogenesis disease model, possibly due to increased expression of anti-angiogenic regulators on chromosome 21. The aim of our study was to elucidate some features of circulating endothelial progenitor cells in the context of this syndrome. Methods Circulating endothelial progenitors of Down syndrome affected individuals were isolated, in vitro cultured and analyzed by confocal and transmission electron microscopy. ELISA was performed to measure SDF-1α plasma levels in Down syndrome and euploid individuals. Moreover, qRT-PCR was used to quantify expression levels of CXCL12 gene and of its receptor in progenitor cells. The functional impairment of Down progenitors was evaluated through their susceptibility to hydroperoxide-induced oxidative stress with BODIPY assay and the major vulnerability to the infection with human pathogens. The differential expression of crucial genes in Down progenitor cells was evaluated by microarray analysis. Results We detected a marked decrease of progenitors' number in young Down individuals compared to euploid, cell size increase and some major detrimental morphological changes. Moreover, Down syndrome patients also exhibited decreased SDF-1α plasma levels and their progenitors had a reduced expression of SDF-1α encoding gene and of its membrane receptor. We further demonstrated that their progenitor cells are more susceptible to hydroperoxide-induced oxidative stress and infection with Bartonella henselae. Further, we observed that most of the differentially expressed genes belong to angiogenesis, immune response and inflammation pathways, and that infected progenitors with trisomy 21 have a more pronounced perturbation of immune response genes than infected euploid cells. Conclusions Our data provide evidences for a reduced number and altered

  10. Competency management: Balancing between commitment and control

    OpenAIRE

    Heinsman, Hanneke; de Hoogh, Annebel H. B.; Koopman, Paul L.; van Muijen, Jaap J.

    2006-01-01

    This study investigated the relationships between commitment and control approaches and the use of competency management by adopting the theory of planned behavior. Questionnaires were filled out by 43 human resource experts working in different organizations. We expected components of the theory of planned behavior to mediate the relationship between commitment and control approaches and the use of competency management (behavior). Regression analysis showed that perceived behavioral control...

  11. COMMITMENT A Psychological Tie and Moral Value

    Science.gov (United States)

    2017-04-01

    Research When I think of commitment, it is a feeling and an action with a strong moral component. However, as I began researching commitment it became...characteristics of “being committed” must be independent of behavior. One mechanism of doing this is through the analysis of bargaining and side bets .27...Becker uses Schelling’s example of bargaining to buy a house to explain side bets . In this scenario, you offer $16,000, but the seller counters with

  12. Quantum bit commitment with misaligned reference frames

    International Nuclear Information System (INIS)

    Harrow, Aram; Oliveira, Roberto; Terhal, Barbara M.

    2006-01-01

    Suppose that Alice and Bob define their coordinate axes differently, and the change of reference frame between them is given by a probability distribution μ over SO(3). We show that this uncertainty of reference frame is of no use for bit commitment when μ is uniformly distributed over a (sub)group of SO(3), but other choices of μ can give rise to a partially or even arbitrarily secure bit commitment

  13. Comparative Analysis of the Hematopoietic Progenitor Cells from Placenta, Cord Blood, and Fetal Liver, Based on Their Immunophenotype

    Directory of Open Access Journals (Sweden)

    Maria D. Kuchma

    2015-01-01

    Full Text Available We have investigated the characteristics of human hematopoietic progenitor cells (HPCs with the CD34+CD45lowSSClow phenotype from full-term placental tissue (FTPT as compared to cord blood (CB and fetal liver (FL cells. We demonstrated the presence of cell subpopulations at various stages of the differentiation with such immunophenotypes as CD34+/lowCD45low/-, CD34++CD45low/-, CD34+++CD45low/-, CD34+/lowCD45hi, and CD34++CD45hi in both first trimester placental tissue (FiTPT and FTPT which implies their higher phenotypic heterogeneity compared to CB. HPCs of the FTPT origin expressed the CD90 antigen at a higher level compared to its expression by the CB HPCs and the CD133 antigen expression being at the same level in both cases. The HPCs compartment of FTPT versus CB contained higher number of myeloid and erythroid committed cells but lower number of myeloid and lymphoid ones compared to FL HPCs. HPCs of the FTPT and CB origin possess similar potentials for the multilineage differentiation in vitro and similar ratios of myeloid and erythroid progenitors among the committed cells. This observation suggests that the active hematopoiesis occurs in the FTPT. We obtained viable HPCs from cryopreserved placental tissue fragments allowing us to develop procedures for banking and testing of placenta-derived HPCs for clinical use.

  14. Meaningful work, work engagement and organisational commitment

    Directory of Open Access Journals (Sweden)

    Madelyn Geldenhuys

    2014-03-01

    Research purpose: The aim of the study was to investigate the relationships amongst psychological meaningfulness, work engagement and organisational commitment and to test for a possible mediation effect of work engagement on the relationship between psychological meaningfulness and organisational commitment. Motivation for the study: Managers have to rethink ways of improving productivity and performance at work, due to the diverse, and in some instances escalating, needs of employees (e.g. financial support to uphold their interest in and enjoyment of working. Research approach, design and method: A quantitative approach was employed to gather the data for the study, utilising a cross-sectional survey design. The sample (n = 415 consisted of working employees from various companies and positions in Gauteng, South Africa. Main findings: The results confirmed a positive relationship between psychological meaningfulness, work engagement and organisational commitment. Further, psychological meaningfulness predicts work engagement, whilst psychological meaningfulness and work engagement predict organisational commitment. Practical/managerial implications: Employers identifying their employees’ commitment patterns and mapping out strategies for enhancing those that are relevant to organisational goals will yield positive work outcomes (e.g. employees who are creative, seek growth or challenges for themselves. Contribution/value-add: This study contributes to the literature through highlighting the impact that meaningful work has on sustaining employee commitment to the organisation.

  15. Commitment and Switching Intentions: Customers and Brands

    Directory of Open Access Journals (Sweden)

    Juliana Werneck Rodrigues

    2012-12-01

    Full Text Available This study aims to evaluate the relationship between a customer’s brand switching intentions and his commitment to a brand. Based on a literature review, constructs related to customer brand commitment were identified (affective and continuance commitment, trust, satisfaction, switching costs and alternative attractiveness and their roles in the formation of brand switching intentions hypothesized. Through a cross-sectional survey, a sample of 201 smartphone users was collected to test the proposed relationships. Data analysis was carried out via structural equations modeling, with direct effects of trust, satisfaction, switching costs and alternative attractiveness upon the different kinds of commitment being verified. Furthermore, both types of brand commitment (affective and continuance were found to negatively impact a customer’s intention to switch brands. Regarding enterprise customer strategies, the research findings suggest that, if firms are able to track customer brand commitment, they could use such knowledge to develop better relationship strategies, minimizing customer defection and further developing customer value to the company.

  16. A novel pathogenic aviadenovirus from red-bellied parrots (Poicephalus rufiventris) unveils deep recombination events among avian host lineages

    International Nuclear Information System (INIS)

    Das, Shubhagata; Fearnside, Kathleen; Sarker, Subir; Forwood, Jade K.; Raidal, Shane R.

    2017-01-01

    Competing roles of coevolution, selective pressure and recombination are an emerging interest in virus evolution. We report a novel aviadenovirus from captive red-bellied parrots (Poicephalus rufiventris) that uncovers evidence of deep recombination among aviadenoviruses. The sequence identity of the virus was most closely related to Turkey adenovirus D (42% similarity) and other adenoviruses in chickens, turkeys and pigeons. Sequencing and comparative analysis showed that the genome comprised 40,930 nucleotides containing 42 predicted open reading frames (ORFs) 19 of which had strong similarity with genes from other adenovirus species. The new genome unveiled a lineage that likely participated in deep recombination events across the genus Aviadenovirus accounting for an ancient evolutionary relationship. We hypothesize frequent host switch events and recombination among adenovirus progenitors in Galloanserae hosts caused the radiation of extant aviadenoviruses and the newly assembled Poicephalus adenovirus genome points to a potentially broader host range of these viruses among birds. - Highlights: •Shows how a single new genome can change overall phylogeny. •Reveals host switch events among adenovirus progenitors in Galloanserae hosts. •Points to a potentially broader host range of adenoviruses among birds and wildlife .

  17. A novel pathogenic aviadenovirus from red-bellied parrots (Poicephalus rufiventris) unveils deep recombination events among avian host lineages

    Energy Technology Data Exchange (ETDEWEB)

    Das, Shubhagata, E-mail: sdas@csu.edu.au [School of Animal and Veterinary Sciences, Faculty of Science, Charles Sturt University, New South Wales 2678 (Australia); Fearnside, Kathleen, E-mail: kathyfearnside@exemail.com.au [Hills District Veterinary Hospital, Unit 1, 276 New Line Road, Dural, NSW 2158 (Australia); Sarker, Subir, E-mail: S.Sarker@latrobe.edu.au [Department of Physiology, Anatomy and Microbiology, School of Life Sciences, La Trobe University, Melbourne, VIC 3086 (Australia); Forwood, Jade K., E-mail: jforwood@csu.edu.au [School of Biomedical Sciences, Faculty of Science, Charles Sturt University, Wagga Wagga, NSW 2650 (Australia); Raidal, Shane R., E-mail: shraidal@csu.edu.au [School of Animal and Veterinary Sciences, Faculty of Science, Charles Sturt University, New South Wales 2678 (Australia)

    2017-02-15

    Competing roles of coevolution, selective pressure and recombination are an emerging interest in virus evolution. We report a novel aviadenovirus from captive red-bellied parrots (Poicephalus rufiventris) that uncovers evidence of deep recombination among aviadenoviruses. The sequence identity of the virus was most closely related to Turkey adenovirus D (42% similarity) and other adenoviruses in chickens, turkeys and pigeons. Sequencing and comparative analysis showed that the genome comprised 40,930 nucleotides containing 42 predicted open reading frames (ORFs) 19 of which had strong similarity with genes from other adenovirus species. The new genome unveiled a lineage that likely participated in deep recombination events across the genus Aviadenovirus accounting for an ancient evolutionary relationship. We hypothesize frequent host switch events and recombination among adenovirus progenitors in Galloanserae hosts caused the radiation of extant aviadenoviruses and the newly assembled Poicephalus adenovirus genome points to a potentially broader host range of these viruses among birds. - Highlights: •Shows how a single new genome can change overall phylogeny. •Reveals host switch events among adenovirus progenitors in Galloanserae hosts. •Points to a potentially broader host range of adenoviruses among birds and wildlife .

  18. Lineage fusion in Galápagos giant tortoises.

    Science.gov (United States)

    Garrick, Ryan C; Benavides, Edgar; Russello, Michael A; Hyseni, Chaz; Edwards, Danielle L; Gibbs, James P; Tapia, Washington; Ciofi, Claudio; Caccone, Adalgisa

    2014-11-01

    Although many classic radiations on islands are thought to be the result of repeated lineage splitting, the role of past fusion is rarely known because during these events, purebreds are rapidly replaced by a swarm of admixed individuals. Here, we capture lineage fusion in action in a Galápagos giant tortoise species, Chelonoidis becki, from Wolf Volcano (Isabela Island). The long generation time of Galápagos tortoises and dense sampling (841 individuals) of genetic and demographic data were integral in detecting and characterizing this phenomenon. In C. becki, we identified two genetically distinct, morphologically cryptic lineages. Historical reconstructions show that they colonized Wolf Volcano from Santiago Island in two temporally separated events, the first estimated to have occurred ~199 000 years ago. Following arrival of the second wave of colonists, both lineages coexisted for approximately ~53 000 years. Within that time, they began fusing back together, as microsatellite data reveal widespread introgressive hybridization. Interestingly, greater mate selectivity seems to be exhibited by purebred females of one of the lineages. Forward-in-time simulations predict rapid extinction of the early arriving lineage. This study provides a rare example of reticulate evolution in action and underscores the power of population genetics for understanding the past, present and future consequences of evolutionary phenomena associated with lineage fusion. © 2014 John Wiley & Sons Ltd.

  19. Cell lineage branching as a strategy for proliferative control.

    Science.gov (United States)

    Buzi, Gentian; Lander, Arthur D; Khammash, Mustafa

    2015-02-19

    How tissue and organ sizes are specified is one of the great unsolved mysteries in biology. Experiments and mathematical modeling implicate feedback control of cell lineage progression, but a broad understanding of what lineage feedback accomplishes is lacking. By exploring the possible effects of various biologically relevant disturbances on the dynamic and steady state behaviors of stem cell lineages, we find that the simplest and most frequently studied form of lineage feedback - which we term renewal control - suffers from several serious drawbacks. These reflect fundamental performance limits dictated by universal conservation-type laws, and are independent of parameter choice. Here we show that introducing lineage branches can circumvent all such limitations, permitting effective attenuation of a wide range of perturbations. The type of feedback that achieves such performance - which we term fate control - involves promotion of lineage branching at the expense of both renewal and (primary) differentiation. We discuss the evidence that feedback of just this type occurs in vivo, and plays a role in tissue growth control. Regulated lineage branching is an effective strategy for dealing with disturbances in stem cell systems. The existence of this strategy provides a dynamics-based justification for feedback control of cell fate in vivo.

  20. [Identification of the Mycobacterium tuberculosis Beijing lineage in Ecuador].

    Science.gov (United States)

    Jiménez, Patricia; Calvopiña, Karina; Herrera, Diana; Rojas, Carlos; Pérez-Lago, Laura; Grijalva, Marcelo; Guna, Remedios; García-de Viedma, Darío

    2017-06-01

    Mycobacterium tuberculosis Beijing lineage isolates are considered to be especially virulent, transmissible and prone to acquire resistances. Beijing strains have been reported worldwide, but studies in Latin America are still scarce. The only multinational study performed in the region indicated a heterogeneous distribution for this lineage, which was absent in Chile, Colombia and Ecuador, although further studies found the lineage in Chile and Colombia. To search for the presence of the Beijing lineage in Ecuador, the only country in the region where it remains unreported. We obtained a convenience sample (2006-2012) from two hospitals covering different populations. The isolates were genotyped using 24-MIRU-VNTR. Lineages were assigned by comparing their patterns to those in the MIRU-VNTRplus platform. Isolates belonging to the Beijing lineage were confirmed by allele-specific PCR. We identified the first Beijing isolate in Ecuador in an unexpected epidemiological scenario: A patient was infected in the Andean region, in a population with low mobility and far from the borders of the neighboring countries where Beijing strains had been previously reported. This is the first report of the presence of the Beijing lineage in Ecuador in an unusual epidemiological context that deserves special attention.

  1. Stochastic differentiation into an osteoclast lineage from cloned macrophage-like cells

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Shin-Ichi, E-mail: shayashi@med.tottori-u.ac.jp [Division of Immunology, Department of Molecular and Cellular Biology, School of Life Science, Faculty of Medicine, Tottori University, 86 Nishi-Cho, Yonago, Tottori 683-8503 (Japan); Murata, Akihiko; Okuyama, Kazuki; Shimoda, Yuhki; Hikosaka, Mari [Division of Immunology, Department of Molecular and Cellular Biology, School of Life Science, Faculty of Medicine, Tottori University, 86 Nishi-Cho, Yonago, Tottori 683-8503 (Japan); Yasuda, Hisataka [Planning and Development, Bioindustry Division, Oriental Yeast Co., Ltd, Itabashi-Ku, Tokyo 174-8505 (Japan); Yoshino, Miya [Division of Immunology, Department of Molecular and Cellular Biology, School of Life Science, Faculty of Medicine, Tottori University, 86 Nishi-Cho, Yonago, Tottori 683-8503 (Japan)

    2012-11-16

    Highlights: Black-Right-Pointing-Pointer The frequency of C7 differentiation into osteoclast was low and constant. Black-Right-Pointing-Pointer Only extended C7 cell cultures exponentially increased osteoclast+ cultures. Black-Right-Pointing-Pointer C7 cell differentiation into committed osteoclast precursors is on 'autopilot'. Black-Right-Pointing-Pointer The system may maintain the stem cell self-renewal and differentiation. -- Abstract: Differentiation into osteoclasts is induced by a macrophage colony-stimulating factor and receptor activator of nuclear-factor {kappa}B ligand. The macrophage-like cell line, C7 has the potential to differentiate into osteoclasts when it is cultured with both factors for 6 days. Although C7 is an established cell line, the frequency of differentiation into this lineage was less than 10%, and the ratio was maintained at a constant level, even after repeated cloning. In this study, to increase the differentiation of C7 cells to osteoclasts, C7 derivative treatments with several activators and/or inhibitors were performed for 3 days prior to setting osteoclast induction analysis; however, a reagent to significantly up-regulate the frequency of differentiation was not found. Only extended cultures for osteoclastogenesis exponentially increased the frequency of osteoclast precursors. It is likely that C7 cell differentiation into committed osteoclast precursors is on 'autopilot' rather than requiring specific signals to drive this process.

  2. Stochastic differentiation into an osteoclast lineage from cloned macrophage-like cells

    International Nuclear Information System (INIS)

    Hayashi, Shin-Ichi; Murata, Akihiko; Okuyama, Kazuki; Shimoda, Yuhki; Hikosaka, Mari; Yasuda, Hisataka; Yoshino, Miya

    2012-01-01

    Highlights: ► The frequency of C7 differentiation into osteoclast was low and constant. ► Only extended C7 cell cultures exponentially increased osteoclast+ cultures. ► C7 cell differentiation into committed osteoclast precursors is on ‘autopilot’. ► The system may maintain the stem cell self-renewal and differentiation. -- Abstract: Differentiation into osteoclasts is induced by a macrophage colony-stimulating factor and receptor activator of nuclear-factor κB ligand. The macrophage-like cell line, C7 has the potential to differentiate into osteoclasts when it is cultured with both factors for 6 days. Although C7 is an established cell line, the frequency of differentiation into this lineage was less than 10%, and the ratio was maintained at a constant level, even after repeated cloning. In this study, to increase the differentiation of C7 cells to osteoclasts, C7 derivative treatments with several activators and/or inhibitors were performed for 3 days prior to setting osteoclast induction analysis; however, a reagent to significantly up-regulate the frequency of differentiation was not found. Only extended cultures for osteoclastogenesis exponentially increased the frequency of osteoclast precursors. It is likely that C7 cell differentiation into committed osteoclast precursors is on ‘autopilot’ rather than requiring specific signals to drive this process.

  3. Fast and scalable inference of multi-sample cancer lineages.

    KAUST Repository

    Popic, Victoria

    2015-05-06

    Somatic variants can be used as lineage markers for the phylogenetic reconstruction of cancer evolution. Since somatic phylogenetics is complicated by sample heterogeneity, novel specialized tree-building methods are required for cancer phylogeny reconstruction. We present LICHeE (Lineage Inference for Cancer Heterogeneity and Evolution), a novel method that automates the phylogenetic inference of cancer progression from multiple somatic samples. LICHeE uses variant allele frequencies of somatic single nucleotide variants obtained by deep sequencing to reconstruct multi-sample cell lineage trees and infer the subclonal composition of the samples. LICHeE is open source and available at http://viq854.github.io/lichee .

  4. Fast and scalable inference of multi-sample cancer lineages.

    KAUST Repository

    Popic, Victoria; Salari, Raheleh; Hajirasouliha, Iman; Kashef-Haghighi, Dorna; West, Robert B; Batzoglou, Serafim

    2015-01-01

    Somatic variants can be used as lineage markers for the phylogenetic reconstruction of cancer evolution. Since somatic phylogenetics is complicated by sample heterogeneity, novel specialized tree-building methods are required for cancer phylogeny reconstruction. We present LICHeE (Lineage Inference for Cancer Heterogeneity and Evolution), a novel method that automates the phylogenetic inference of cancer progression from multiple somatic samples. LICHeE uses variant allele frequencies of somatic single nucleotide variants obtained by deep sequencing to reconstruct multi-sample cell lineage trees and infer the subclonal composition of the samples. LICHeE is open source and available at http://viq854.github.io/lichee .

  5. PET imaging of adoptive progenitor cell therapies

    International Nuclear Information System (INIS)

    Gelovani, Juri G.

    2008-01-01

    The overall objective of this application is to develop novel technologies for non-invasive imaging of adoptive stem cell-based therapies with positron emission tomography (PET) that would be applicable to human patients. To achieve this objective, stem cells will be genetically labeled with a PET-reporter gene and repetitively imaged to assess their distribution, migration, differentiation, and persistence using a radiolabeled reporter probe. This new imaging technology will be tested in adoptive progenitor cell-based therapy models in animals, including: delivery pro-apoptotic genes to tumors, and T-cell reconstitution for immunostimulatory therapy during allogeneic bone marrow progenitor cell transplantation. Technical and Scientific Merits. Non-invasive whole body imaging would significantly aid in the development and clinical implementation of various adoptive progenitor cell-based therapies by providing the means for non-invasive monitoring of the fate of injected progenitor cells over a long period of observation. The proposed imaging approaches could help to address several questions related to stem cell migration and homing, their long-term viability, and their subsequent differentiation. The ability to image these processes non-invasively in 3D and repetitively over a long period of time is very important and will help the development and clinical application of various strategies to control and direct stem cell migration and differentiation. Approach to accomplish the work. Stem cells will be genetically with a reporter gene which will allow for repetitive non-invasive 'tracking' of the migration and localization of genetically labeled stem cells and their progeny. This is a radically new approach that is being developed for future human applications and should allow for a long term (many years) repetitive imaging of the fate of tissues that develop from the transplanted stem cells. Why the approach is appropriate. The novel approach to stem cell imaging

  6. Cardiac Progenitor Cell Extraction from Human Auricles

    KAUST Repository

    Di Nardo, Paolo

    2017-02-22

    For many years, myocardial tissue has been considered terminally differentiated and, thus, incapable of regenerating. Recent studies have shown, instead, that cardiomyocytes, at least in part, are slowly substituted by new cells originating by precursor cells mostly embedded into the heart apex and in the atria. We have shown that an elective region of progenitor cell embedding is represented by the auricles, non-contractile atria appendages that can be easily sampled without harming the patient. The protocol here reported describes how from auricles a population of multipotent, cardiogenic cells can be isolated, cultured, and differentiated. Further studies are needed to fully exploit this cell population, but, sampling auricles, it could be possible to treat cardiac patients using their own cells circumventing rejection or organ shortage limitations.

  7. PET imaging of adoptive progenitor cell therapies.

    Energy Technology Data Exchange (ETDEWEB)

    Gelovani, Juri G.

    2008-05-13

    Objectives. The overall objective of this application is to develop novel technologies for non-invasive imaging of adoptive stem cell-based therapies with positron emission tomography (PET) that would be applicable to human patients. To achieve this objective, stem cells will be genetically labeled with a PET-reporter gene and repetitively imaged to assess their distribution, migration, differentiation, and persistence using a radiolabeled reporter probe. This new imaging technology will be tested in adoptive progenitor cell-based therapy models in animals, including: delivery pro-apoptotic genes to tumors, and T-cell reconstitution for immunostimulatory therapy during allogeneic bone marrow progenitor cell transplantation. Technical and Scientific Merits. Non-invasive whole body imaging would significantly aid in the development and clinical implementation of various adoptive progenitor cell-based therapies by providing the means for non-invasive monitoring of the fate of injected progenitor cells over a long period of observation. The proposed imaging approaches could help to address several questions related to stem cell migration and homing, their long-term viability, and their subsequent differentiation. The ability to image these processes non-invasively in 3D and repetitively over a long period of time is very important and will help the development and clinical application of various strategies to control and direct stem cell migration and differentiation. Approach to accomplish the work. Stem cells will be genetically with a reporter gene which will allow for repetitive non-invasive “tracking” of the migration and localization of genetically labeled stem cells and their progeny. This is a radically new approach that is being developed for future human applications and should allow for a long term (many years) repetitive imaging of the fate of tissues that develop from the transplanted stem cells. Why the approach is appropriate. The novel approach to

  8. Positive selection on the nonhomologous end-joining factor Cernunnos-XLF in the human lineage

    Directory of Open Access Journals (Sweden)

    Jurka Jerzy

    2006-06-01

    Full Text Available Abstract Background Cernunnos-XLF is a nonhomologous end-joining factor that is mutated in patients with a rare immunodeficiency with microcephaly. Several other microcephaly-associated genes such as ASPM and microcephalin experienced recent adaptive evolution apparently linked to brain size expansion in humans. In this study we investigated whether Cernunnos-XLF experienced similar positive selection during human evolution. Results We obtained or reconstructed full-length coding sequences of chimpanzee, rhesus macaque, canine, and bovine Cernunnos-XLF orthologs from sequence databases and sequence trace archives. Comparison of coding sequences revealed an excess of nonsynonymous substitutions consistent with positive selection on Cernunnos-XLF in the human lineage. The hotspots of adaptive evolution are concentrated around a specific structural domain, whose analogue in the structurally similar XRCC4 protein is involved in binding of another nonhomologous end-joining factor, DNA ligase IV. Conclusion Cernunnos-XLF is a microcephaly-associated locus newly identified to be under adaptive evolution in humans, and possibly played a role in human brain expansion. We speculate that Cernunnos-XLF may have contributed to the increased number of brain cells in humans by efficient double strand break repair, which helps to prevent frequent apoptosis of neuronal progenitors and aids mitotic cell cycle progression. Reviewers This article was reviewed by Chris Ponting and Richard Emes (nominated by Chris Ponting, Kateryna Makova, Gáspár Jékely and Eugene V. Koonin.

  9. Neuropilin-2 genomic elements drive cre recombinase expression in primitive blood, vascular and neuronal lineages.

    Science.gov (United States)

    Wiszniak, Sophie; Scherer, Michaela; Ramshaw, Hayley; Schwarz, Quenten

    2015-11-01

    We have established a novel Cre mouse line, using genomic elements encompassing the Nrp2 locus, present within a bacterial artificial chromosome clone. By crossing this Cre driver line to R26R LacZ reporter mice, we have documented the temporal expression and lineage traced tissues in which Cre is expressed. Nrp2-Cre drives expression in primitive blood cells arising from the yolk sac, venous and lymphatic endothelial cells, peripheral sensory ganglia, and the lung bud. This mouse line will provide a new tool to researchers wishing to study the development of various tissues and organs in which this Cre driver is expressed, as well as allow tissue-specific knockout of genes of interest to study protein function. This work also presents the first evidence for expression of Nrp2 protein in a mesodermal progenitor with restricted hematopoietic potential, which will significantly advance the study of primitive erythropoiesis. genesis 53:709-717, 2015. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  10. Reduced Abd-B Hox function during kidney development results in lineage infidelity.

    Science.gov (United States)

    Magella, Bliss; Mahoney, Robert; Adam, Mike; Potter, S Steven

    2018-06-15

    Hox genes can function as key drivers of segment identity, with Hox mutations in Drosophila often resulting in dramatic homeotic transformations. In addition, however, they can serve other essential functions. In mammals, the study of Hox gene roles in development is complicated by the presence of four Hox clusters with a total of 39 genes showing extensive functional overlap. In this study, in order to better understand shared core Hox functions, we examined kidney development in mice with frameshift mutations of multiple Abd-B type Hox genes. The resulting phenotypes included dramatically reduced branching morphogenesis of the ureteric bud, premature depletion of nephron progenitors and abnormal development of the stromal compartment. Most unexpected, however, we also observed a cellular level lineage infidelity in nephron segments. Scattered cells within the proximal tubules, for example, expressed genes normally expressed only in collecting ducts. Multiple combinations of inappropriate nephron segment specific marker expression were found. In some cases, cells within a tubule showed incorrect identity, while in other cases cells showed ambiguous character, with simultaneous expression of genes associated with more than one nephron segment. These results give evidence that Hox genes have an overlapping core function at the cellular level in driving and/or maintaining correct differentiation decisions. Copyright © 2018 Elsevier Inc. All rights reserved.

  11. Cytokinetics and Regulation of Progenitor Cells

    Energy Technology Data Exchange (ETDEWEB)

    Lajtha, L. G. [Paterson Laboratories, Christie Hospital and Holt Radium Institute, Manchester (United Kingdom)

    1967-07-15

    Full text: In spite of great differences in the life-span of fully differentiated haemic cells, the cellular kinetics of their production appears to be similar. Recent evidence indicates a common ultimate stem cell for most of the cells in the peripheral blood. The various pathways of differentiation, however, result in transient dividing and differentiating cell populations which differ from each other not only in their specific biochemical processes but also in the manner of control and kinetic pattern of their proliferation. The population best understood is the erythroid progenitor series of cells, primarily because it has the greatest number of experimentally measurable parameters at the present. This will be discussed in detail and comparisons will be made with the myeloid and lymphoid progenitor populations. The fine structure of the bone-marrow stem cell population will be examined in particular, with regard to the suitability or otherwise of the current stem cell models to explain the kinetic pattern of all the peripheral blood elements after perturbations of their steady-state values. Four different assay methods of bone-marrow stem cells have been examined with regard to the kinetic pattern following perturbation of the steady-state system, e.g. by irradiation. Basically, the stem cell assays fall into two categories: those depending on grafting haemopoietic cells into suitably treated recipients, and those in which recovery of the population is allowed in the animal in which the perturbation was produced, without handling the cells. Evidence is accumulating which indicates that in the grafting techniques, a selective loss of stem cells may occur, . especially stem cells in cell cycle, hence in early stages of recovery of the population unduly low numerical values might be noted. In view of this observation, the concept of the colony-forming cell may have to be revised and instead the colony-forming property of the stem cell introduced. (author)

  12. A COMPREHENSIVE PROGENITOR MODEL FOR SNe Ia

    International Nuclear Information System (INIS)

    Meng, X.; Yang, W.

    2010-01-01

    Although the nature of the progenitor of Type Ia supernovae (SNe Ia) is still unclear, the single-degenerate (SD) channel for the progenitor is currently accepted, in which a carbon-oxygen white dwarf (CO WD) accretes hydrogen-rich material from its companion, increases its mass to the Chandrasekhar mass limit, and then explodes as an SN Ia. The companion may be a main sequence or a slightly evolved star (WD + MS), or a red giant star (WD + RG). Incorporating the effect of mass stripping and accretion-disk instability on the evolution of the WD binary, we carried out binary stellar evolution calculations for more than 1600 close WD binaries. As a result, the initial parameter spaces for SNe Ia are presented in an orbital period-secondary mass (log P i , M i 2 ) plane. We confirmed that in a WD + MS system, the initial companion leading to SNe Ia may have mass from 1 M sun to 5 M sun . The initial WD mass for SNe Ia from WD + MS channel is as low as 0.565 M sun , while the lowest WD mass from the WD + RG channel is 1.0 M sun . Adopting the above results, we studied the birth rate of SNe Ia via a binary population synthesis approach. We found that the Galactic SNe Ia birth rate from SD model is (2.55-2.9) x 10 -3 yr -1 (including WD + He star channel), which is slightly smaller than that from observation. If a single starburst is assumed, the distribution of the delay time of SNe Ia from the SD model may be a weak bimodality, where WD + He channel contributes to SNe Ia with delay time shorter than 10 8 yr and WD + RG channel to those with age longer than 6 Gyr.

  13. Cytokinetics and Regulation of Progenitor Cells

    International Nuclear Information System (INIS)

    Lajtha, L.G.

    1967-01-01

    Full text: In spite of great differences in the life-span of fully differentiated haemic cells, the cellular kinetics of their production appears to be similar. Recent evidence indicates a common ultimate stem cell for most of the cells in the peripheral blood. The various pathways of differentiation, however, result in transient dividing and differentiating cell populations which differ from each other not only in their specific biochemical processes but also in the manner of control and kinetic pattern of their proliferation. The population best understood is the erythroid progenitor series of cells, primarily because it has the greatest number of experimentally measurable parameters at the present. This will be discussed in detail and comparisons will be made with the myeloid and lymphoid progenitor populations. The fine structure of the bone-marrow stem cell population will be examined in particular, with regard to the suitability or otherwise of the current stem cell models to explain the kinetic pattern of all the peripheral blood elements after perturbations of their steady-state values. Four different assay methods of bone-marrow stem cells have been examined with regard to the kinetic pattern following perturbation of the steady-state system, e.g. by irradiation. Basically, the stem cell assays fall into two categories: those depending on grafting haemopoietic cells into suitably treated recipients, and those in which recovery of the population is allowed in the animal in which the perturbation was produced, without handling the cells. Evidence is accumulating which indicates that in the grafting techniques, a selective loss of stem cells may occur, . especially stem cells in cell cycle, hence in early stages of recovery of the population unduly low numerical values might be noted. In view of this observation, the concept of the colony-forming cell may have to be revised and instead the colony-forming property of the stem cell introduced. (author)

  14. THE PROGENITOR OF THE TYPE IIb SN 2008ax REVISITED

    Energy Technology Data Exchange (ETDEWEB)

    Folatelli, Gastón; Bersten, Melina C.; Benvenuto, Omar G. [Instituto de Astrofísica de La Plata (Argentina); Kuncarayakti, Hanindyo [Millennium Institute of Astrophysics (MAS), Casilla 36-D, Santiago (Chile); Maeda, Keiichi; Nomoto, Ken’ichi, E-mail: gaston@fcaglp.unlp.edu.ar [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan)

    2015-10-01

    Hubble Space Telescope observations of the site of the supernova (SN) SN 2008ax obtained in 2011 and 2013 reveal that the possible progenitor object detected in pre-explosion images was in fact multiple. Four point sources are resolved in the new, higher-resolution images. We identify one of the sources with the fading SN. The other three objects are consistent with single supergiant stars. We conclude that their light contaminated the previously identified progenitor candidate. After subtraction of these stars, the progenitor appears to be significantly fainter and bluer than previously measured. Post-explosion photometry at the SN location indicates that the progenitor object has disappeared. If single, the progenitor is compatible with a supergiant star of B to mid-A spectral type, while a Wolf–Rayet (W-R) star would be too luminous in the ultraviolet to account for the observations. Moreover, our hydrodynamical modeling shows that the pre-explosion mass was 4–5 M{sub ⊙} and the radius was 30–50 R{sub ⊙}, which is incompatible with a W-R progenitor. We present a possible interacting binary progenitor computed with our evolutionary models that reproduces all the observational evidence. A companion star as luminous as an O9–B0 main-sequence star may have remained after the explosion.

  15. Ionizing radiation induces apoptosis in hematopoietic stem and progenitor cells

    International Nuclear Information System (INIS)

    Meng, A.; Zhou, D.; Geiger, H.; Zant, G.V.

    2003-01-01

    The aims of this study was to determine if ionizing radiation (IR) induces apoptosis in hematopoietic stem (HSC) and progenitor cells. Lin-cells were isolated from mouse bone marrow (BM) and pretreated with vehicle or 100 μM z-VAD 1 h prior to exposure to 4 Gy IR. The apoptotic and/or necrotic responses of these cells to IR were analyzed by measuring the annexin V and/or 7-AAD staining in HSC and progenitor populations using flow cytometry, and hematopoietic function of these cells was determined by CAFC assay. Exposure of Lin-cells to IR selectively decreased the numbers of HSC and progenitors in association with an increase in apoptosis in a time-dependent manner. Pretreatment of Lin- cells with z-VAD significantly inhibited IR-induced apoptosis and the decrease in the numbers of HSC and progenitors. However, IR alone or in combination with z-VAD did not lead to a significant increase in necrotic cell death in either HSC or progenitors. In addition, pretreatment of BM cells with z-VAD significantly attenuated IR-induced reduction in the frequencies of day-7, -28 and -35 CAFC. Exposure of HSC and progenitors to IR induces apoptosis. The induction of HSC and progenitor apoptosis contributes to IR-induced suppression of their hematopoietic function

  16. THE PROGENITOR OF THE TYPE IIb SN 2008ax REVISITED

    International Nuclear Information System (INIS)

    Folatelli, Gastón; Bersten, Melina C.; Benvenuto, Omar G.; Kuncarayakti, Hanindyo; Maeda, Keiichi; Nomoto, Ken’ichi

    2015-01-01

    Hubble Space Telescope observations of the site of the supernova (SN) SN 2008ax obtained in 2011 and 2013 reveal that the possible progenitor object detected in pre-explosion images was in fact multiple. Four point sources are resolved in the new, higher-resolution images. We identify one of the sources with the fading SN. The other three objects are consistent with single supergiant stars. We conclude that their light contaminated the previously identified progenitor candidate. After subtraction of these stars, the progenitor appears to be significantly fainter and bluer than previously measured. Post-explosion photometry at the SN location indicates that the progenitor object has disappeared. If single, the progenitor is compatible with a supergiant star of B to mid-A spectral type, while a Wolf–Rayet (W-R) star would be too luminous in the ultraviolet to account for the observations. Moreover, our hydrodynamical modeling shows that the pre-explosion mass was 4–5 M ⊙ and the radius was 30–50 R ⊙ , which is incompatible with a W-R progenitor. We present a possible interacting binary progenitor computed with our evolutionary models that reproduces all the observational evidence. A companion star as luminous as an O9–B0 main-sequence star may have remained after the explosion

  17. Progenitor potential of nkx6.1-expressing cells throughout zebrafish life and during beta cell regeneration.

    Science.gov (United States)

    Ghaye, Aurélie P; Bergemann, David; Tarifeño-Saldivia, Estefania; Flasse, Lydie C; Von Berg, Virginie; Peers, Bernard; Voz, Marianne L; Manfroid, Isabelle

    2015-09-02

    In contrast to mammals, the zebrafish has the remarkable capacity to regenerate its pancreatic beta cells very efficiently. Understanding the mechanisms of regeneration in the zebrafish and the differences with mammals will be fundamental to discovering molecules able to stimulate the regeneration process in mammals. To identify the pancreatic cells able to give rise to new beta cells in the zebrafish, we generated new transgenic lines allowing the tracing of multipotent pancreatic progenitors and endocrine precursors. Using novel bacterial artificial chromosome transgenic nkx6.1 and ascl1b reporter lines, we established that nkx6.1-positive cells give rise to all the pancreatic cell types and ascl1b-positive cells give rise to all the endocrine cell types in the zebrafish embryo. These two genes are initially co-expressed in the pancreatic primordium and their domains segregate, not as a result of mutual repression, but through the opposite effects of Notch signaling, maintaining nkx6.1 expression while repressing ascl1b in progenitors. In the adult zebrafish, nkx6.1 expression persists exclusively in the ductal tree at the tip of which its expression coincides with Notch active signaling in centroacinar/terminal end duct cells. Tracing these cells reveals that they are able to differentiate into other ductal cells and into insulin-expressing cells in normal (non-diabetic) animals. This capacity of ductal cells to generate endocrine cells is supported by the detection of ascl1b in the nkx6.1:GFP ductal cell transcriptome. This transcriptome also reveals, besides actors of the Notch and Wnt pathways, several novel markers such as id2a. Finally, we show that beta cell ablation in the adult zebrafish triggers proliferation of ductal cells and their differentiation into insulin-expressing cells. We have shown that, in the zebrafish embryo, nkx6.1+ cells are bona fide multipotent pancreatic progenitors, while ascl1b+ cells represent committed endocrine precursors. In

  18. Lineage-Restricted Mammary Stem Cells Sustain the Development, Homeostasis, and Regeneration of the Estrogen Receptor Positive Lineage.

    Science.gov (United States)

    Van Keymeulen, Alexandra; Fioramonti, Marco; Centonze, Alessia; Bouvencourt, Gaëlle; Achouri, Younes; Blanpain, Cédric

    2017-08-15

    The mammary gland (MG) is composed of different cell lineages, including the basal and the luminal cells (LCs) that are maintained by distinct stem cell (SC) populations. LCs can be subdivided into estrogen receptor (ER) + and ER - cells. LCs act as the cancer cell of origin in different types of mammary tumors. It remains unclear whether the heterogeneity found in luminal-derived mammary tumors arises from a pre-existing heterogeneity within LCs. To investigate LC heterogeneity, we used lineage tracing to assess whether the ER + lineage is maintained by multipotent SCs or by lineage-restricted SCs. To this end, we generated doxycycline-inducible ER-rtTA mice that allowed us to perform genetic lineage tracing of ER + LCs and study their fate and long-term maintenance. Our results show that ER + cells are maintained by lineage-restricted SCs that exclusively contribute to the expansion of the ER + lineage during puberty and their maintenance during adult life. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  19. TOX sets the stage for innate lymphoid cells

    NARCIS (Netherlands)

    Spits, Hergen

    2015-01-01

    Like T cells and B cells, innate lymphoid cells (ILCs) develop from common lymphoid progenitors, but how commitment to the ILC lineage is regulated has remained unclear. The transcriptional regulator TOX is important in this process

  20. PAX7 Targets, CD54, Integrin α9β1, and SDC2, Allow Isolation of Human ESC/iPSC-Derived Myogenic Progenitors

    Directory of Open Access Journals (Sweden)

    Alessandro Magli

    2017-06-01

    Full Text Available Pluripotent stem (PS-cell-derived cell types hold promise for treating degenerative diseases. However, PS cell differentiation is intrinsically heterogeneous; therefore, clinical translation requires the development of practical methods for isolating progenitors from unwanted and potentially teratogenic cells. Muscle-regenerating progenitors can be derived through transient PAX7 expression. To better understand the biology, and to discover potential markers for these cells, here we investigate PAX7 genomic targets and transcriptional changes in human cells undergoing PAX7-mediated myogenic commitment. We identify CD54, integrin α9β1, and Syndecan2 (SDC2 as surface markers on PAX7-induced myogenic progenitors. We show that these markers allow for the isolation of myogenic progenitors using both fluorescent- and CGMP-compatible magnetic-based sorting technologies and that CD54+α9β1+SDC2+ cells contribute to long-term muscle regeneration in vivo. These findings represent a critical step toward enabling the translation of PS-cell-based therapies for muscle diseases.

  1. Mesoderm Lineage 3D Tissue Constructs Are Produced at Large-Scale in a 3D Stem Cell Bioprocess.

    Science.gov (United States)

    Cha, Jae Min; Mantalaris, Athanasios; Jung, Sunyoung; Ji, Yurim; Bang, Oh Young; Bae, Hojae

    2017-09-01

    Various studies have presented different approaches to direct pluripotent stem cell differentiation such as applying defined sets of exogenous biochemical signals and genetic/epigenetic modifications. Although differentiation to target lineages can be successfully regulated, such conventional methods are often complicated, laborious, and not cost-effective to be employed to the large-scale production of 3D stem cell-based tissue constructs. A 3D-culture platform that could realize the large-scale production of mesoderm lineage tissue constructs from embryonic stem cells (ESCs) is developed. ESCs are cultured using our previously established 3D-bioprocess platform which is amenable to mass-production of 3D ESC-based tissue constructs. Hepatocarcinoma cell line conditioned medium is introduced to the large-scale 3D culture to provide a specific biomolecular microenvironment to mimic in vivo mesoderm formation process. After 5 days of spontaneous differentiation period, the resulting 3D tissue constructs are composed of multipotent mesodermal progenitor cells verified by gene and molecular expression profiles. Subsequently the optimal time points to trigger terminal differentiation towards cardiomyogenesis or osteogenesis from the mesodermal tissue constructs is found. A simple and affordable 3D ESC-bioprocess that can reach the scalable production of mesoderm origin tissues with significantly improved correspondent tissue properties is demonstrated. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Neural induction from ES cells portrays default commitment but instructive maturation.

    Directory of Open Access Journals (Sweden)

    Nibedita Lenka

    Full Text Available The neural induction has remained a debatable issue pertaining to whether it is a mere default process or it involves precise instructive cues. We have chosen the embryonic stem (ES cell model to address this issue. In a devised monoculture strategy, the cell-cell interaction availed through optimum cell plating density could define the niche for the attainment of efficient in vitro neurogenesis from the ES cells. The medium plating density was found ideal in generating optimum number of progenitors and also yielded about 80% mature neurons in a serum free culture set up barring any exogenous inducers. We could also demarcate and quantify the neural stem cells/progenitors among the heterogeneous cell population of differentiating ES cells using nestin intron II driven EGFP expression as a tool. The one week post-plating was determined to be the critical time window for optimum neural progenitor generation from ES cells that helped us further in purifying these cells and in demonstrating their proliferation and multipotent differentiation potential. Seeding cells at varying densities, we could decipher an interesting paradoxical scenario that interlinked both commitment and maturation with the initial plating density having a vital influence on neuronal maturation but not specification and the secretory factors were apparently playing a key role during this process. Thus it was comprehended that, the neural specification was a default process independent of exogenous factors and cellular interaction. Conversely, a defined number of cells at the specification stage itself seemed critical to provide an auto-/paracrine means of signaling threshold for the maturation process to materialize.

  3. Induced adult stem (iAS) cells and induced transit amplifying progenitor (iTAP) cells-a possible alternative to induced pluripotent stem (iPS) cells?

    Science.gov (United States)

    Heng, Boon Chin; Richards, Mark; Ge, Zigang; Shu, Yimin

    2010-02-01

    The successful derivation of iPSC lines effectively demonstrates that it is possible to reset the 'developmental clock' of somatic cells all the way back to the initial embryonic state. Hence, it is plausible that this clock may instead be turned back half-way to a less immature developmental stage that is more directly applicable to clinical therapeutic applications or for in vitro pharmacology/toxicology screening assays. Such a suitable developmental state is postulated to be either the putative transit amplifying progenitor stage or adult stem cell stage. It is hypothetically possible to reprogram mature and terminally differentiated somatic cells back to the adult stem cell or transit amplifying progenitor stage, in a manner similar to the derivation of iPSC. It is proposed that the terminology 'Induced Adult Stem Cells' (iASC) or 'Induced Transit Amplifying Progenitor Cells' (iTAPC) be used to described such reprogrammed somatic cells. Of particular interest, is the possibility of resetting the developmental clock of mature differentiated somatic cells of the mesenchymal lineage, explanted from adipose tissue, bone marrow and cartilage. The putative adult stem cell sub-population from which these cells are derived, commonly referred to as 'mesenchymal stem cells', are highly versatile and hold much therapeutic promise in regenerative medicine, as attested to by numerous human clinical trials and animal studies. Perhaps it may be appropriate to term such reprogrammed cells as 'Induced Mesenchymal Stem Cells' (iMSC) or as 'Induced Mesenchumal Progenitor Cells' (iMPC). Given that cells from the same organ/tissue will share some commonalities in gene expression, we hypothesize that the generation of iASC or iTAPC would be more efficient as compared to iPSC generation, since a common epigenetic program must exist between the reprogrammed cells, adult stem cell or progenitor cell types and terminally differentiated cell types from the same organ/tissue.

  4. Does smoking cannabis affect work commitment?

    Science.gov (United States)

    Hyggen, Christer

    2012-07-01

      This study aimed to examine the associations between cannabis use and work commitment.   We used a 25-year panel survey initiated in 1985 with follow-ups in 1987, 1989, 1993, 2003 and 2010. Registered data from a range of public registers were matched with individual responses for the entire period.   The panel survey was a nation-wide study set in Norway.   A total of 1997 respondents born between 1965 and 1968 were included in the panel.   Work involvement scale (WIS) was used to assess work commitment. Involvement with cannabis was based on self-reported smoking of cannabis within the last 12 months and exposure to cannabis through friends. This information was categorized into 'abstaining', 'exposed', 'experimented' and 'involved'. Control measures included socio-economic background, mental health (HSCL-10), education, work satisfaction, unemployment, receipt of social assistance, consumption of alcohol, alcohol-related problems and use of other illicit drugs.   The level of work commitment was associated with involvement with cannabis. In 1993, when the respondents were in their mid-20s, those who were involved or had experimented with cannabis displayed lower levels of work commitment than those who were abstaining or merely exposed to cannabis through friends (P labour market experiences, mental health and family characteristics (P Norway the use of cannabis is associated with a reduction in work commitment among adults. © 2012 The Author, Addiction © 2012 Society for the Study of Addiction.

  5. Sympatric speciation: perfume preferences of orchid bee lineages.

    Science.gov (United States)

    Jackson, Duncan E

    2008-12-09

    Female attraction to an environmentally derived mating signal released by male orchid bees may be tightly linked to shared olfactory preferences of both sexes. A change in perfume preference may have led to divergence of two morphologically distinct lineages.

  6. Involvement of multiple cell lineages in atherogenesis | Ogeng'o ...

    African Journals Online (AJOL)

    Involvement of multiple cell lineages in atherogenesis. ... mast cells, dendritic cells, macrophages and immigrant cells usually found in blood, namely ... which influence inflammation, migration, proliferation and secretory activity of each other in ...

  7. Neural stem/progenitor cells are activated during tail regeneration in the leopard gecko (Eublepharis macularius).

    Science.gov (United States)

    Gilbert, E A B; Vickaryous, M K

    2018-02-01

    As for many lizards, the leopard gecko (Eublepharis macularius) can self-detach its tail to avoid predation and then regenerate a replacement. The replacement tail includes a regenerated spinal cord with a simple morphology: an ependymal layer surrounded by nerve tracts. We hypothesized that cells within the ependymal layer of the original spinal cord include populations of neural stem/progenitor cells (NSPCs) that contribute to the regenerated spinal cord. Prior to tail loss, we performed a bromodeoxyuridine pulse-chase experiment and found that a subset of ependymal layer cells (ELCs) were label-retaining after a 140-day chase period. Next, we conducted a detailed spatiotemporal characterization of these cells before, during, and after tail regeneration. Our findings show that SOX2, a hallmark protein of NSPCs, is constitutively expressed by virtually all ELCs before, during, and after regeneration. We also found that during regeneration, ELCs express an expanded panel of NSPC and lineage-restricted progenitor cell markers, including MSI-1, SOX9, and TUJ1. Using electron microscopy, we determined that multiciliated, uniciliated, and biciliated cells are present, although the latter was only observed in regenerated spinal cords. Our results demonstrate that cells within the ependymal layer of the original, regenerating and fully regenerate spinal cord represent a heterogeneous population. These include radial glia comparable to Type E and Type B cells, and a neuronal-like population of cerebrospinal fluid-contacting cells. We propose that spinal cord regeneration in geckos represents a truncation of the restorative trajectory observed in some urodeles and teleosts, resulting in the formation of a structurally distinct replacement. © 2017 Wiley Periodicals, Inc.

  8. New insights into the cellular makeup and progenitor potential of palatal connective tissues.

    Science.gov (United States)

    Pall, Emoke; Cenariu, Mihai; Kasaj, Adrian; Florea, Adrian; Soancă, Andrada; Roman, Alexandra; Georgiu, Carmen

    2017-12-01

    The present study investigated the regenerative potential of connective tissues harvested from two palatal areas widely used as donor sites for muco-gingival surgical approaches. Connective tissue grafts (CTGs) were obtained by de-epithelialisation of a free gingival graft (deCTG) and by a split flap approach from a previous donor site (reCTG). Two types of mesenchymal stem cell (MSCs) were isolated and were named de-epithelialised MSCs (deMSCs) and re-entry MSCs (reMSCs). The cells were characterised and cellular functionality was investigated. CTGs were evaluated using immunohistochemical and ultrastructural approaches. No significant differences were observed regarding the frequency of colony-forming unit- fibroblasts, migration potential, and population doubling time between the two cell lines (p > 0.05). Both cell lines showed positivity for CD105, CD73, CD90, and CD44 and negative expression for CD34/45, CD14, CD79a, and HLA-DR. MSCs from both cell lines successfully differentiated into osteogenic, adipogenic, and chondrogenic lineages. Cells expressing antigens characteristic of CD34+ stromal cells (CD34+, αSMA-, CD31-) were traced in both CTGs. Ultrastructural analysis highlighted the presence of putative progenitors, namely fibroblasts,-in the pericapillary regions and in remote regions of the lamina propria- and pericytes-surrounding the capillaries. This study provides supplementary arguments for the use of CTG grafts in clinical practice due to the presence of putative progenitor cell. However, results were inconclusive regarding clinical decision-making to determine optimal harvesting area. Prior harvesting in the donor area did not appear to alter the regenerative capabilities of the connective tissue. © 2017 Wiley Periodicals, Inc.

  9. Catalase inhibits ionizing radiation-induced apoptosis in hematopoietic stem and progenitor cells.

    Science.gov (United States)

    Xiao, Xia; Luo, Hongmei; Vanek, Kenneth N; LaRue, Amanda C; Schulte, Bradley A; Wang, Gavin Y

    2015-06-01

    Hematologic toxicity is a major cause of mortality in radiation emergency scenarios and a primary side effect concern in patients undergoing chemo-radiotherapy. Therefore, there is a critical need for the development of novel and more effective approaches to manage this side effect. Catalase is a potent antioxidant enzyme that coverts hydrogen peroxide into hydrogen and water. In this study, we evaluated the efficacy of catalase as a protectant against ionizing radiation (IR)-induced toxicity in hematopoietic stem and progenitor cells (HSPCs). The results revealed that catalase treatment markedly inhibits IR-induced apoptosis in murine hematopoietic stem cells and hematopoietic progenitor cells. Subsequent colony-forming cell and cobble-stone area-forming cell assays showed that catalase-treated HSPCs can not only survive irradiation-induced apoptosis but also have higher clonogenic capacity, compared with vehicle-treated cells. Moreover, transplantation of catalase-treated irradiated HSPCs results in high levels of multi-lineage and long-term engraftments, whereas vehicle-treated irradiated HSPCs exhibit very limited hematopoiesis reconstituting capacity. Mechanistically, catalase treatment attenuates IR-induced DNA double-strand breaks and inhibits reactive oxygen species. Unexpectedly, we found that the radioprotective effect of catalase is associated with activation of the signal transducer and activator of transcription 3 (STAT3) signaling pathway and pharmacological inhibition of STAT3 abolishes the protective activity of catalase, suggesting that catalase may protect HSPCs against IR-induced toxicity via promoting STAT3 activation. Collectively, these results demonstrate a previously unrecognized mechanism by which catalase inhibits IR-induced DNA damage and apoptosis in HSPCs.

  10. Improving the characterization of endothelial progenitor cell subsets by an optimized FACS protocol.

    Directory of Open Access Journals (Sweden)

    Karin Huizer

    Full Text Available The characterization of circulating endothelial progenitor cells (EPCs is fundamental to any study related to angiogenesis. Unfortunately, current literature lacks consistency in the definition of EPC subsets due to variations in isolation strategies and inconsistencies in the use of lineage markers. Here we address critical points in the identification of hematopoietic progenitor cells (HPCs, circulating endothelial cells (CECs, and culture-generated outgrowth endothelial cells (OECs from blood samples of healthy adults (AB and umbilical cord (UCB. Peripheral blood mononuclear cells (PBMCs were enriched using a Ficoll-based gradient followed by an optimized staining and gating strategy to enrich for the target cells. Sorted EPC populations were subjected to RT-PCR for tracing the expression of markers beyond the limits of cell surface-based immunophenotyping. Using CD34, CD133 and c-kit staining, combined with FSC and SSC, we succeeded in the accurate and reproducible identification of four HPC subgroups and found significant differences in the respective populations in AB vs. UCB. Co-expression analysis of endothelial markers on HPCs revealed a complex pattern characterized by various subpopulations. CECs were identified by using CD34, KDR, CD45, and additional endothelial markers, and were subdivided according to their apoptotic state and expression of c-kit. Comparison of UCB-CECs vs. AB-CECs revealed significant differences in CD34 and KDR levels. OECs were grown from PBMC-fractions We found that viable c-kit+ CECs are a candidate circulating precursor for CECs. RT-PCR to angiogenic factors and receptors revealed that all EPC subsets expressed angiogenesis-related molecules. Taken together, the improvements in immunophenotyping and gating strategies resulted in accurate identification and comparison of better defined cell populations in a single procedure.

  11. Influence of Teacher Empowerment on Teachers' Organizational Commitment, Professional Commitment and Organizational Citizenship Behavior in Schools

    Science.gov (United States)

    Bogler, Ronit; Somech, Anit

    2004-01-01

    The present study focuses on the relationship between teacher empowerment and teachers' organizational commitment, professional commitment (PC) and organizational citizenship behavior (OCB). It examines which subscales of teacher empowerment can best predict these outcomes. The data were collected through a questionnaire returned by a sample of…

  12. Perceived Sacrifice and Few Alternatives Commitments: The Motivational Underpinnings of Continuance Commitment's Subdimensions

    Science.gov (United States)

    Vandenberghe, Christian; Panaccio, Alexandra

    2012-01-01

    Using work on self-concepts and Conservation of Resources theory, the present research examined the motivational underpinnings of continuance commitment's subcomponents of perceived sacrifice and few alternatives. Study 1 (N=208) found job scope to be positively related to perceived sacrifice commitment, and negatively related to few alternatives…

  13. Romantic Relationship Commitment and Its Linkages with Commitment to Parents and Friends during Adolescence

    Science.gov (United States)

    De Goede, Irene H. A.; Branje, Susan; van Duin, Jet; VanderValk, Inge E.; Meeus, Wim

    2012-01-01

    This five-wave longitudinal study examines linkages between adolescents' perceptions of romantic relationship commitment and the development of adolescents' perceptions of commitment to parents and friends. A total of 218 early-to-middle adolescents (39.0 percent boys) and 185 middle-to-late adolescents (30.8 percent boys) participated.…

  14. Two Hemocyte Lineages Exist in Silkworm Larval Hematopoietic Organ

    OpenAIRE

    Nakahara, Yuichi; Kanamori, Yasushi; Kiuchi, Makoto; Kamimura, Manabu

    2010-01-01

    BACKGROUND: Insects have multiple hemocyte morphotypes with different functions as do vertebrates, however, their hematopoietic lineages are largely unexplored with the exception of Drosophila melanogaster. METHODOLOGY/PRINCIPAL FINDINGS: To study the hematopoietic lineage of the silkworm, Bombyx mori, we investigated in vivo and in vitro differentiation of hemocyte precursors in the hematopoietic organ (HPO) into the four mature hemocyte subsets, namely, plasmatocytes, granulocytes, oenocyto...

  15. Metabolic regulation of hematopoietic and leukemic stem/progenitor cells under homeostatic and stress conditions.

    Science.gov (United States)

    Karigane, Daiki; Takubo, Keiyo

    2017-07-01

    Hematopoietic stem cells (HSCs) exhibit multilineage differentiation and self-renewal activities that maintain the entire hematopoietic system during an organism's lifetime. These abilities are sustained by intrinsic transcriptional programs and extrinsic cues from the microenvironment or niche. Recent studies using metabolomics technologies reveal that metabolic regulation plays an essential role in HSC maintenance. Metabolic pathways provide energy and building blocks for other factors functioning at steady state and in stress. Here we review recent advances in our understanding of metabolic regulation in HSCs relevant to cell cycle quiescence, symmetric/asymmetric division, and proliferation following stress and lineage commitment, and discuss the therapeutic potential of targeting metabolic factors or pathways to treat hematological malignancies.

  16. Policy Uncertainty, Investment and Commitment Periods

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    Today's investment decisions in key sectors such as energy, forestry or transport have significant impacts on the levels of greenhouse gas (GHG) emissions over the coming decades. Given the economic and environmental long-term implications of capital investment and retirement, a climate mitigation regime should aim to encourage capital investment in climate-friendly technologies. Many factors affect technology choice and the timing of investment, including investor expectations about future prices and policies. Recent international discussions have focused on the importance of providing more certainty about future climate policy stringency. The design of commitment periods can play a role in creating this environment. This paper assesses how the length of commitment periods influences policy uncertainty and investment decisions. In particular, the paper analyses the relationship between commitment period length and near term investment decisions in climate friendly technology.

  17. Two hemocyte lineages exist in silkworm larval hematopoietic organ.

    Directory of Open Access Journals (Sweden)

    Yuichi Nakahara

    Full Text Available BACKGROUND: Insects have multiple hemocyte morphotypes with different functions as do vertebrates, however, their hematopoietic lineages are largely unexplored with the exception of Drosophila melanogaster. METHODOLOGY/PRINCIPAL FINDINGS: To study the hematopoietic lineage of the silkworm, Bombyx mori, we investigated in vivo and in vitro differentiation of hemocyte precursors in the hematopoietic organ (HPO into the four mature hemocyte subsets, namely, plasmatocytes, granulocytes, oenocytoids, and spherulocytes. Five days after implantation of enzymatically-dispersed HPO cells from a GFP-expressing transgenic line into the hemocoel of normal larvae, differentiation into plasmatocytes, granulocytes and oenocytoids, but not spherulocytes, was observed. When the HPO cells were cultured in vitro, plasmatocytes appeared rapidly, and oenocytoids possessing prophenol oxidase activity appeared several days later. HPO cells were also able to differentiate into a small number of granulocytes, but not into spherulocytes. When functionally mature plasmatocytes were cultured in vitro, oenocytoids were observed 10 days later. These results suggest that the hemocyte precursors in HPO first differentiate into plasmatocytes, which further change into oenocytoids. CONCLUSIONS/SIGNIFICANCE: From these results, we propose that B. mori hemocytes can be divided into two major lineages, a granulocyte lineage and a plasmatocyte-oenocytoid lineage. The origins of the spherulocytes could not be determined in this study. We construct a model for the hematopoietic lineages at the larval stage of B. mori.

  18. Two hemocyte lineages exist in silkworm larval hematopoietic organ.

    Science.gov (United States)

    Nakahara, Yuichi; Kanamori, Yasushi; Kiuchi, Makoto; Kamimura, Manabu

    2010-07-28

    Insects have multiple hemocyte morphotypes with different functions as do vertebrates, however, their hematopoietic lineages are largely unexplored with the exception of Drosophila melanogaster. To study the hematopoietic lineage of the silkworm, Bombyx mori, we investigated in vivo and in vitro differentiation of hemocyte precursors in the hematopoietic organ (HPO) into the four mature hemocyte subsets, namely, plasmatocytes, granulocytes, oenocytoids, and spherulocytes. Five days after implantation of enzymatically-dispersed HPO cells from a GFP-expressing transgenic line into the hemocoel of normal larvae, differentiation into plasmatocytes, granulocytes and oenocytoids, but not spherulocytes, was observed. When the HPO cells were cultured in vitro, plasmatocytes appeared rapidly, and oenocytoids possessing prophenol oxidase activity appeared several days later. HPO cells were also able to differentiate into a small number of granulocytes, but not into spherulocytes. When functionally mature plasmatocytes were cultured in vitro, oenocytoids were observed 10 days later. These results suggest that the hemocyte precursors in HPO first differentiate into plasmatocytes, which further change into oenocytoids. From these results, we propose that B. mori hemocytes can be divided into two major lineages, a granulocyte lineage and a plasmatocyte-oenocytoid lineage. The origins of the spherulocytes could not be determined in this study. We construct a model for the hematopoietic lineages at the larval stage of B. mori.

  19. Organizational identification and commitment: correlates of sense of belonging and affective commitment.

    Science.gov (United States)

    Dávila, Ma Celeste; Jiménez García, Gemma

    2012-03-01

    The general purpose of this work is to analyze the overlap between organizational identification and commitment. Specifically, our study focuses on the analysis of the differences and similarities between sense of belonging (a dimension of organizational identification) and affective commitment (a dimension of organizational commitment). In order to do this, we analyzed their discriminant validity and raised their relationship with variables that previous research had showed like precedent and subsequent variables of them: value congruence, perceived support, organizational citizenship behavior, and intention to continue in the organization. A total of 292 people at one organization completed surveys measuring the variables previously described. The results showed that sense of belonging and affective commitment are different concepts and they have different relationships with relation to precedent and subsequent variables. Affective commitment seems to be more useful than sense of belonging to predict organizational citizenship behavior aimed at the organization and intention to continue. Some practical implications are described.

  20. 28 CFR 522.11 - Civil contempt commitments.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Civil contempt commitments. 522.11..., CLASSIFICATION, AND TRANSFER ADMISSION TO INSTITUTION Civil Contempt of Court Commitments § 522.11 Civil contempt commitments. Inmates can come into Bureau custody for civil contempt commitments in two ways: (a) The U.S...

  1. Commitment Elements Reframed (Antecedents & Consequences) for Organizational Effectiveness

    Science.gov (United States)

    Fornes, Sandra L.; Rocco, Tonette S.

    2004-01-01

    The purpose of this paper is to identify theories of commitment in the workplace to develop a framework that helps the field create higher levels of commitment, productivity, and satisfaction. The paper is organized into five main sections: the method, commitment in the workplace, mapping workplace commitment, and the implications for HRD and…

  2. Intermediate Progenitor Cohorts Differentially Generate Cortical Layers and Require Tbr2 for Timely Acquisition of Neuronal Subtype Identity

    Directory of Open Access Journals (Sweden)

    Anca B. Mihalas

    2016-06-01

    Full Text Available Intermediate progenitors (IPs amplify the production of pyramidal neurons, but their role in selective genesis of cortical layers or neuronal subtypes remains unclear. Using genetic lineage tracing in mice, we find that IPs destined to produce upper cortical layers first appear early in corticogenesis, by embryonic day 11.5. During later corticogenesis, IP laminar fates are progressively limited to upper layers. We examined the role of Tbr2, an IP-specific transcription factor, in laminar fate regulation using Tbr2 conditional mutant mice. Upon Tbr2 inactivation, fewer neurons were produced by immediate differentiation and laminar fates were shifted upward. Genesis of subventricular mitoses was, however, not reduced in the context of a Tbr2-null cortex. Instead, neuronal and laminar differentiation were disrupted and delayed. Our findings indicate that upper-layer genesis depends on IPs from many stages of corticogenesis and that Tbr2 regulates the tempo of laminar fate implementation for all cortical layers.

  3. FGF signalling controls the specification of hair placode-derived SOX9 positive progenitors to Merkel cells.

    Science.gov (United States)

    Nguyen, Minh Binh; Cohen, Idan; Kumar, Vinod; Xu, Zijian; Bar, Carmit; Dauber-Decker, Katherine L; Tsai, Pai-Chi; Marangoni, Pauline; Klein, Ophir D; Hsu, Ya-Chieh; Chen, Ting; Mikkola, Marja L; Ezhkova, Elena

    2018-06-13

    Merkel cells are innervated mechanosensory cells responsible for light-touch sensations. In murine dorsal skin, Merkel cells are located in touch domes and found in the epidermis around primary hairs. While it has been shown that Merkel cells are skin epithelial cells, the progenitor cell population that gives rise to these cells is unknown. Here, we show that during embryogenesis, SOX9-positive (+) cells inside hair follicles, which were previously known to give rise to hair follicle stem cells (HFSCs) and cells of the hair follicle lineage, can also give rise to Merkel Cells. Interestingly, while SOX9 is critical for HFSC specification, it is dispensable for Merkel cell formation. Conversely, FGFR2 is required for Merkel cell formation but is dispensable for HFSCs. Together, our studies uncover SOX9(+) cells as precursors of Merkel cells and show the requirement for FGFR2-mediated epithelial signalling in Merkel cell specification.

  4. Endothelial progenitor cells in chronic obstructive pulmonary disease and emphysema

    Science.gov (United States)

    Tracy, Russell P.; Parikh, Megha A.; Hoffman, Eric A.; Shimbo, Daichi; Austin, John H. M.; Smith, Benjamin M.; Hueper, Katja; Vogel-Claussen, Jens; Lima, Joao; Gomes, Antoinette; Watson, Karol; Kawut, Steven; Barr, R. Graham

    2017-01-01

    Endothelial injury is implicated in the pathogenesis of COPD and emphysema; however the role of endothelial progenitor cells (EPCs), a marker of endothelial cell repair, and circulating endothelial cells (CECs), a marker of endothelial cell injury, in COPD and its subphenotypes is unresolved. We hypothesized that endothelial progenitor cell populations would be decreased in COPD and emphysema and that circulating endothelial cells would be increased. Associations with other subphenotypes were examined. The Multi-Ethnic Study of Atherosclerosis COPD Study recruited smokers with COPD and controls age 50–79 years without clinical cardiovascular disease. Endothelial progenitor cell populations (CD34+KDR+ and CD34+KDR+CD133+ cells) and circulating endothelial cells (CD45dimCD31+CD146+CD133-) were measured by flow cytometry. COPD was defined by standard spirometric criteria. Emphysema was assessed qualitatively and quantitatively on CT. Full pulmonary function testing and expiratory CTs were measured in a subset. Among 257 participants, both endothelial progenitor cell populations, and particularly CD34+KDR+ endothelial progenitor cells, were reduced in COPD. The CD34+KDR+CD133+ endothelial progenitor cells were associated inversely with emphysema extent. Both endothelial progenitor cell populations were associated inversely with extent of panlobular emphysema and positively with diffusing capacity. Circulating endothelial cells were not significantly altered in COPD but were inversely associated with pulmonary microvascular blood flow on MRI. There was no consistent association of endothelial progenitor cells or circulating endothelial cells with measures of gas trapping. These data provide evidence that endothelial repair is impaired in COPD and suggest that this pathological process is specific to emphysema. PMID:28291826

  5. Reciprocal upregulation of Notch signaling molecules in hematopoietic progenitor and mesenchymal stromal cells

    Directory of Open Access Journals (Sweden)

    Kikuchi Y

    2011-01-01

    Full Text Available Although mesenchymal stem cells (MSCs play pivotal supportive roles in hematopoiesis, how they interact with hematopoietic stem cells (HSCs is not well understood. We investigated the interaction between HSCs and surrogate MSCs (C3H10T1/2 stromal cells, focusing on the molecular events induced by cell contact of these bipartite populations. C3H10T1/2 is a mesenchymal stromal cell line that can be induced to differentiate into preadipocytes (A54 and myoblasts (M1601. The stromal cell derivatives were cocultured with murine HSCs (Lineage-Sca1+, and gene expression profiles in stromal cells and HSCs were compared before and after the coculture. HSCs gave rise to cobblestone areas only on A54 cells, with ninefold more progenitors than on M1601 or undifferentiated C3H10T1/2 cells. Microarray-based screening and a quantitative reverse transcriptase directed-polymerase chain reaction showed that the levels of Notch ligands (Jagged1 and Delta-like 3 were increased in A54 cells upon interaction with HSCs. On the other hand, the expression of Notch1 and Hes1 was upregulated in the HSCs cocultured with A54 cells. A transwell assay revealed that the reciprocal upregulation was dependent on cell-to-cell contact. The result suggested that in the hematopoietic niche, HSCs help MSCs to produce Notch ligands, and in turn, MSCs help HSCs to express Notch receptor. Such a reciprocal upregulation would reinforce the downstream signaling to determine the fate of hematopoietic cell lineage. Clarification of the initiating events on cell contact should lead to the identification of specific molecular targets to facilitate HSC engraftment in transplantation therapy.

  6. Biology and flow cytometry of proangiogenic hematopoietic progenitors cells.

    Science.gov (United States)

    Rose, Jonathan A; Erzurum, Serpil; Asosingh, Kewal

    2015-01-01

    During development, hematopoiesis and neovascularization are closely linked to each other via a common bipotent stem cell called the hemangioblast that gives rise to both hematopoietic cells and endothelial cells. In postnatal life, this functional connection between the vasculature and hematopoiesis is maintained by a subset of hematopoietic progenitor cells endowed with the capacity to differentiate into potent proangiogenic cells. These proangiogenic hematopoietic progenitors comprise a specific subset of bone marrow (BM)-derived cells that homes to sites of neovascularization and possess potent paracrine angiogenic activity. There is emerging evidence that this subpopulation of hematopoietic progenitors plays a critical role in vascular health and disease. Their angiogenic activity is distinct from putative "endothelial progenitor cells" that become structural cells of the endothelium by differentiation into endothelial cells. Proangiogenic hematopoietic progenitor cell research requires multidisciplinary expertise in flow cytometry, hematology, and vascular biology. This review provides a comprehensive overview of proangiogenic hematopoietic progenitor cell biology and flow cytometric methods to detect these cells in the peripheral blood circulation and BM. © 2014 International Society for Advancement of Cytometry.

  7. LINKING TYPE Ia SUPERNOVA PROGENITORS AND THEIR RESULTING EXPLOSIONS

    International Nuclear Information System (INIS)

    Foley, Ryan J.; Kirshner, Robert P.; Simon, Joshua D.; Burns, Christopher R.; Gal-Yam, Avishay; Hamuy, Mario; Morrell, Nidia I.; Phillips, Mark M.; Shields, Gregory A.; Sternberg, Assaf

    2012-01-01

    Comparing the ejecta velocities at maximum brightness and narrow circumstellar/interstellar Na D absorption line profiles of a sample of 23 Type Ia supernovae (SNe Ia), we determine that the properties of SN Ia progenitor systems and explosions are intimately connected. As demonstrated by Sternberg et al., half of all SNe Ia with detectable Na D absorption at the host-galaxy redshift in high-resolution spectroscopy have Na D line profiles with significant blueshifted absorption relative to the strongest absorption component, which indicates that a large fraction of SN Ia progenitor systems have strong outflows. In this study, we find that SNe Ia with blueshifted circumstellar/interstellar absorption systematically have higher ejecta velocities and redder colors at maximum brightness relative to the rest of the SN Ia population. This result is robust at a 98.9%-99.8% confidence level, providing the first link between the progenitor systems and properties of the explosion. This finding is further evidence that the outflow scenario is the correct interpretation of the blueshifted Na D absorption, adding additional confirmation that some SNe Ia are produced from a single-degenerate progenitor channel. An additional implication is that either SN Ia progenitor systems have highly asymmetric outflows that are also aligned with the SN explosion or SNe Ia come from a variety of progenitor systems where SNe Ia from systems with strong outflows tend to have more kinetic energy per unit mass than those from systems with weak or no outflows.

  8. Measuring Asian nurses' organizational commitment: a critical analysis of the psychometric properties of two organizational commitment instruments.

    Science.gov (United States)

    Liou, Shwu-Ru; Tsai, Hsiu-Min; Cheng, Ching-Yu

    2013-01-01

    To analyze and compare the psychometric properties and cultural attributes of the Organizational Commitment Questionnaire and the Organizational Commitment Scale to determine their appropriateness for measuring commitment of Asian nurses, the biggest portion of international nurses. The Organizational Commitment Questionnaire was cross-culturally cross-validated when compared with the Organizational Commitment Scale. Both instruments were not tested on Asian nurses. More studies are needed to validate the cultural properties of the Organizational Commitment Scale. Healthcare administrators can use culturally validated instruments, which concern cultural context, including languages and cultural values, to understand Asian nurses' organizational commitment and further lower turnover behavior among them. © 2013 Wiley Periodicals, Inc.

  9. Wnt signaling positively regulates endothelial cell fate specification in the Fli1a-positive progenitor population via Lef1.

    Science.gov (United States)

    Hübner, Kathleen; Grassme, Kathrin S; Rao, Jyoti; Wenke, Nina K; Zimmer, Cordula L; Korte, Laura; Mu Ller, Katja; Sumanas, Saulius; Greber, Boris; Herzog, Wiebke

    2017-10-01

    During vertebrate embryogenesis, vascular endothelial cells (ECs) and primitive erythrocytes become specified within close proximity in the posterior lateral plate mesoderm (LPM) from a common progenitor. However, the signaling cascades regulating the specification into either lineage remain largely elusive. Here, we analyze the contribution of β-catenin dependent Wnt signaling to EC and erythrocyte specification during zebrafish embryogenesis. We generated novel β-catenin dependent Wnt signaling reporters which, by using destabilized fluorophores (Venus-Pest, dGFP), specifically allow us to detect Wnt signaling responses in narrow time windows as well as in spatially restricted domains, defined by Cre recombinase expression (Tg(axin2 BAC :Venus-Pest) mu288 ; Tg(14TCF:loxP-STOP-loxP-dGFP) mu202 ). We therefore can detect β-catenin dependent Wnt signaling activity in a subset of the Fli1a-positive progenitor population. Additionally, we show that mesodermal Wnt3a-mediated signaling via the transcription factor Lef1 positively regulates EC specification (defined by kdrl expression) at the expense of primitive erythrocyte specification (defined by gata1 expression) in zebrafish embryos. Using mesoderm derived from human embryonic stem cells, we identified the same principle of Wnt signaling dependent EC specification in conjunction with auto-upregulation of LEF1. Our data indicate a novel role of β-catenin dependent Wnt signaling in regulating EC specification during vasculogenesis. Copyright © 2017. Published by Elsevier Inc.

  10. Trophoblast lineage cells derived from human induced pluripotent stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ying, E-mail: ying.chen@hc.msu.edu [Department of Obstetrics, Gynecology and Reproductive Biology, Michigan State University, 333 Bostwick NE, Grand Rapids, MI 49503 (United States); Wang, Kai; Chandramouli, Gadisetti V.R. [Department of Obstetrics, Gynecology and Reproductive Biology, Michigan State University, 333 Bostwick NE, Grand Rapids, MI 49503 (United States); Knott, Jason G. [Developmental Epigenetics Laboratory, Department of Animal Science, Michigan State University (United States); Leach, Richard, E-mail: Richard.leach@hc.msu.edu [Department of Obstetrics, Gynecology and Reproductive Biology, Michigan State University, 333 Bostwick NE, Grand Rapids, MI 49503 (United States); Department of Obstetrics, Gynecology and Women’s Health, Spectrum Health Medical Group (United States)

    2013-07-12

    Highlights: •Epithelial-like phenotype of trophoblast lineage cells derived from human iPS cells. •Trophoblast lineage cells derived from human iPS cells exhibit trophoblast function. •Trophoblasts from iPS cells provides a proof-of-concept in regenerative medicine. -- Abstract: Background: During implantation, the blastocyst trophectoderm attaches to the endometrial epithelium and continues to differentiate into all trophoblast subtypes, which are the major components of a placenta. Aberrant trophoblast proliferation and differentiation are associated with placental diseases. However, due to ethical and practical issues, there is almost no available cell or tissue source to study the molecular mechanism of human trophoblast differentiation, which further becomes a barrier to the study of the pathogenesis of trophoblast-associated diseases of pregnancy. In this study, our goal was to generate a proof-of-concept model for deriving trophoblast lineage cells from induced pluripotency stem (iPS) cells from human fibroblasts. In future studies the generation of trophoblast lineage cells from iPS cells established from patient’s placenta will be extremely useful for studying the pathogenesis of individual trophoblast-associated diseases and for drug testing. Methods and results: Combining iPS cell technology with BMP4 induction, we derived trophoblast lineage cells from human iPS cells. The gene expression profile of these trophoblast lineage cells was distinct from fibroblasts and iPS cells. These cells expressed markers of human trophoblasts. Furthermore, when these cells were differentiated they exhibited invasive capacity and placental hormone secretive capacity, suggesting extravillous trophoblasts and syncytiotrophoblasts. Conclusion: Trophoblast lineage cells can be successfully derived from human iPS cells, which provide a proof-of-concept tool to recapitulate pathogenesis of patient placental trophoblasts in vitro.

  11. Trophoblast lineage cells derived from human induced pluripotent stem cells

    International Nuclear Information System (INIS)

    Chen, Ying; Wang, Kai; Chandramouli, Gadisetti V.R.; Knott, Jason G.; Leach, Richard

    2013-01-01

    Highlights: •Epithelial-like phenotype of trophoblast lineage cells derived from human iPS cells. •Trophoblast lineage cells derived from human iPS cells exhibit trophoblast function. •Trophoblasts from iPS cells provides a proof-of-concept in regenerative medicine. -- Abstract: Background: During implantation, the blastocyst trophectoderm attaches to the endometrial epithelium and continues to differentiate into all trophoblast subtypes, which are the major components of a placenta. Aberrant trophoblast proliferation and differentiation are associated with placental diseases. However, due to ethical and practical issues, there is almost no available cell or tissue source to study the molecular mechanism of human trophoblast differentiation, which further becomes a barrier to the study of the pathogenesis of trophoblast-associated diseases of pregnancy. In this study, our goal was to generate a proof-of-concept model for deriving trophoblast lineage cells from induced pluripotency stem (iPS) cells from human fibroblasts. In future studies the generation of trophoblast lineage cells from iPS cells established from patient’s placenta will be extremely useful for studying the pathogenesis of individual trophoblast-associated diseases and for drug testing. Methods and results: Combining iPS cell technology with BMP4 induction, we derived trophoblast lineage cells from human iPS cells. The gene expression profile of these trophoblast lineage cells was distinct from fibroblasts and iPS cells. These cells expressed markers of human trophoblasts. Furthermore, when these cells were differentiated they exhibited invasive capacity and placental hormone secretive capacity, suggesting extravillous trophoblasts and syncytiotrophoblasts. Conclusion: Trophoblast lineage cells can be successfully derived from human iPS cells, which provide a proof-of-concept tool to recapitulate pathogenesis of patient placental trophoblasts in vitro

  12. Competency management : Balancing between commitment and control

    NARCIS (Netherlands)

    Heinsman, H.; Hoogh, de A.H.B.; Muijen, van J.J.; Koopman, P.L.

    2006-01-01

    This study investigated the relationships between commitment and control approaches and the use of competency management by adopting the theory of planned behavior. Questionnaires were filled out by 43 human resource experts working in different organizations. We expected components of the theory of

  13. New Commitment Options: Compatibility with Emissions Trading

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This paper considers different options for quantitative greenhouse gas emission commitments from the standpoint of their technical compatibility with emissions trading. These are dynamic targets, binding targets with price caps, non-binding targets, sector-wide targets/mechanisms, action targets, allowances and endowments, and long-term permits. This paper considers these options from the standpoint of their compatibility with emissions trading.

  14. Evolution of collective commitment during teamwork

    NARCIS (Netherlands)

    Dunin-Keplicz, B; Verbrugge, R

    In this paper we aim to describe dynamic aspects of social and collective attitudes in teams of agents involved in Cooperative Problem Solving (CPS). Particular attention is given to the strongest motivational attitude, collective commitment, and its evolution during team action. First, building on

  15. Reflections: The Worldwide Commitment to Educational Equality.

    Science.gov (United States)

    Meyer, John W.

    2001-01-01

    Comments on articles appearing in the 2001 theme issue of Sociology of Education. Considers the nature and impact of the widespread cultural commitment to educational equality. Discusses other aspects of education not emphasized in this issue, such as the implications of racial inequality, credentialism, and educational organization (CAJ)

  16. Race, Commitment to Deviance, and Spoiled Identity

    Science.gov (United States)

    Harris, Anthony R.

    1976-01-01

    Data generated by 234 young black and white inmates in 1971 challenge the assumption that spoiled identity is a necessary, socially invariant outcome of deviant commitment and self-definition. For blacks, the relationship between criminal self-typing and stability and esteem is negative but inconsequential; for whites, the relationship is negative…

  17. Sport commitment in adolescent soccer players

    Directory of Open Access Journals (Sweden)

    Noelia Belando Pedreño

    2016-03-01

    Full Text Available The aim of this study was to contribute to the postulates of the self-determination theory, the hierarchical model of intrinsic and extrinsic motivation by Vallerand, and social goals. A structural regression model was estimated to analyze the relations between social goals (responsibility and relationships, praise for autonomous behavior, satisfaction of the basic psychological needs and intrinsic motivation in commitment to sport. A sample of 264 young Spanish soccer players aged between 14 and 16 (M =14.74, SD =.77 participated in the study. Structural Equation Modeling results showed that the social responsibility goal, the social relationship goal and praise for autonomous behavior predicted perceived competence. Furthermore, the relationship goal also predicted the need for relatedness. Satisfaction of the basic psychological needs for competence and relatedness predicted intrinsic motivation. Intrinsic motivation positively predicted future commitment to sport. These results highlighted the importance of social goals, praise for autonomous behavior and psychological mediators in encouraging greater commitment in young soccer players. Future research should focus on the coach’s role in generating greater commitment to sport through the development of intervention methodologies based on social goals.

  18. Factors Predicting Faculty Commitment to the University.

    Science.gov (United States)

    Fjortoft, Nancy

    This paper examines the effect of faculty rank, satisfaction with salary, working conditions, institutional reputation, perceived influence on institutional policies, participation in meetings, and perceived governance on organizational commitment (at both the departmental and institutional level) using a representative sample of 4,925 faculty.…

  19. Predicting volunteer commitment in environmental stewardship programmes

    Science.gov (United States)

    Robert L. Ryan; Rachel Kaplan; Robert E. Grese

    2001-01-01

    The natural environment benefits greatly from the work of volunteers in environmental stewardship programmes. However, little is known about volunteers' motivations for continued participation in these programmes. This study looked at the relationship between volunteer commitment and motivation, as well as the effect that volunteering has on participants'...

  20. Children's Developing Commitments to Joint Goals

    Science.gov (United States)

    Hamann, Katharina; Warneken, Felix; Tomasello, Michael

    2012-01-01

    This study investigated young children's commitment to a joint goal by assessing whether peers in collaborative activities continue to collaborate until all received their rewards. Forty-eight 2.5- and 3.5-year-old children worked on an apparatus dyadically. One child got access to her reward early. For the partner to benefit as well, this child…

  1. Packaging of Sin Goods - Commitment or Exploitation?

    DEFF Research Database (Denmark)

    Nafziger, Julia

    to such self-control problems, and possibly exploit them, by offering different package sizes. In a competitive market, either one or three (small, medium and large) packages are offered. In contrast to common intuition, the large, and not the small package is a commitment device. The latter serves to exploit...

  2. Influencing Organizational Commitment through Office Redesign

    Science.gov (United States)

    Morrow, Paula C.; McElroy, James C.; Scheibe, Kevin P.

    2012-01-01

    Prior research on the effects of office redesign on work-related outcomes has been largely a theoretical and yielded mixed and conflicting findings. Expanding on individual reactions to office design changes as specified by social interference theory, we propose that office redesign affects organizational commitment and this relationship is…

  3. Organizational Commitment through Organizational Socialization Tactics

    Science.gov (United States)

    Filstad, Cathrine

    2011-01-01

    Purpose: The aim of this paper is to investigate how organizational socialization tactics affect newcomers' organizational commitment and learning processes. Design/methodology/approach: A survey was conducted using a measurement tool based on Van Maanen and Schein's theory on organizational socialization tactics and Kuvaas' measurement tools of…

  4. Fuzzy Array Approach to Unit Commitment

    DEFF Research Database (Denmark)

    Jantzen, Jan; Eliasson, Bo

    1996-01-01

    The paper investigates the unit commitment problem of Swedish power company Sydkraft as a constraint satisfaction problem. The power system is a simplified system with nuclear, thermal, and hydro generators as well as power interchange. In this paper we focus on soft constraints, for instance...

  5. Resistance, Justice, and Commitment to Change

    Science.gov (United States)

    Foster, Rex D.

    2010-01-01

    This research focused on individual responses to organizational change by exploring the relationships among individual resistance, organizational justice, and commitment to change following organizational change implementations in three organizations. To accomplish this, Web-based questionnaires were used to gather individual-level quantitative…

  6. Organizational Justice and Commitment in Interscholastic Sports

    Science.gov (United States)

    Whisenant, Warren

    2005-01-01

    The purpose of this study was to determine the effect of three organizational justice dimensions on the commitment of high school student athletes (N = 480) to continue playing a referent sport. The athletes were asked to complete an instrument designed to assess their perceived levels of justice displayed by their coaches in three justice…

  7. Non-linear Capital Taxation Without Commitment

    OpenAIRE

    Emmanuel Farhi; Christopher Sleet; Iván Werning; Sevin Yeltekin

    2012-01-01

    We study efficient non-linear taxation of labour and capital in a dynamic Mirrleesian model incorporating political economy constraints. Policies are chosen sequentially over time, without commitment. Our main result is that the marginal tax on capital income is progressive, in the sense that richer agents face higher marginal tax rates. Copyright , Oxford University Press.

  8. An Analysis of Organisational Commitment by Academic ...

    African Journals Online (AJOL)

    The aim of this study was to investigate organisational commitment in the era of the new psychological contract, or the psychological environment created by an economic down turn in Zimbabwe. The psychological contract that exists between employees and organisations is brittle due to many organisational changes ...

  9. From commitment to practice: the EU response

    Directory of Open Access Journals (Sweden)

    Joanne van Selm

    2012-06-01

    Full Text Available Events in North Africa in 2011 transformed the pattern of boat arrivals in Europe – significantly in terms of the motivations of those arriving but with smaller numbers than might have been anticipated. The EU’s response indicates that more is needed to translate a commitment to solidarity from limited aid and statements of principle into practical reality

  10. Affective Commitment among Student Affairs Professionals

    Science.gov (United States)

    Boehman, Joseph

    2007-01-01

    Student affairs professionals in the United States were surveyed to determine the predictive value of overall job satisfaction, organizational support, organizational politics, and work/nonwork interaction on affective organizational commitment. Results indicate that a supportive work environment leads to increased affective attachment to the…

  11. Personal factors affecting organizational commitment of records ...

    African Journals Online (AJOL)

    This study investigated personal factors affecting organizational commitment among records management personnel in the state universities in Nigeria. Simple cluster sampling with equal allocation method was used to select 180 records management personnel from the study population. A five item organizational ...

  12. Comparison of direct and indirect radiation effects on osteoclast formation from progenitor cells derived from different hemopoietic sources.

    Science.gov (United States)

    Scheven, B A; Wassenaar, A M; Kawilarang-de Haas, E W; Nijweide, P J

    1987-07-01

    Hemopoietic stem and progenitor cells from different sources differ in radiosensitivity. Recently, we have demonstrated that the multinucleated cell responsible for bone resorption and marrow cavity formation, the osteoclast, is in fact of hemopoietic lineage. In this investigation we have studied the radiosensitivity of osteoclast formation from two different hemopoietic tissues: fetal liver and adult bone marrow. Development of osteoclasts from hemopoietic progenitors was induced by coculture of hemopoietic cell populations with fetal mouse long bones depleted of their own osteoclast precursor pool. During culture, osteoclasts developed from the exogenous cell population and invaded the calcified hypertrophic cartilage of the long bone model, thereby giving rise to the formation of a primitive marrow cavity. To analyze the radiosensitivity of osteoclast formation, either the hemopoietic cells or the bone rudiments were irradiated before coculture. Fetal liver cells were found to be less radiosensitive than bone marrow cells. The D0, Dq values and extrapolation numbers were 1.69 Gy, 5.30 Gy, and 24.40 for fetal liver cells and 1.01 Gy, 1.85 Gy, and 6.02 for bone marrow cells. Irradiation of the (pre)osteoclast-free long bone rudiments instead of the hemopoietic sources resulted in a significant inhibition of osteoclast formation at doses of 4 Gy or more. This indirect effect appeared to be more prominent in the cocultures with fetal than with adult hemopoietic cells. Furthermore, radiation doses of 8.0-10.0 Gy indirectly affected the appearance of other cell types (e.g., granulocytes) in the newly formed but underdeveloped marrow cavity. The results indicate that osteoclast progenitors from different hemopoietic sources exhibit a distinct sensitivity to ionizing irradiation. Radiation injury to long bone rudiments disturbs the osteoclast-forming capacity as well as the hemopoietic microenvironment.

  13. Connective Tissue Growth Factor reporter mice label a subpopulation of mesenchymal progenitor cells that reside in the trabecular bone region.

    Science.gov (United States)

    Wang, Wen; Strecker, Sara; Liu, Yaling; Wang, Liping; Assanah, Fayekah; Smith, Spenser; Maye, Peter

    2015-02-01

    Few gene markers selectively identify mesenchymal progenitor cells inside the bone marrow. We have investigated a cell population located in the mouse bone marrow labeled by Connective Tissue Growth Factor reporter expression (CTGF-EGFP). Bone marrow flushed from CTGF reporter mice yielded an EGFP+ stromal cell population. Interestingly, the percentage of stromal cells retaining CTGF reporter expression decreased with age in vivo and was half the frequency in females compared to males. In culture, CTGF reporter expression and endogenous CTGF expression marked the same cell types as those labeled using Twist2-Cre and Osterix-Cre fate mapping approaches, which previously had been shown to identify mesenchymal progenitors in vitro. Consistent with this past work, sorted CTGF+ cells displayed an ability to differentiate into osteoblasts, chondrocytes, and adipocytes in vitro and into osteoblast, adipocyte, and stromal cell lineages after transplantation into a parietal bone defect. In vivo examination of CTGF reporter expression in bone tissue sections revealed that it marked cells highly localized to the trabecular bone region and was not expressed in the perichondrium or periosteum. Mesenchymal cells retaining high CTGF reporter expression were adjacent to, but distinct from mature osteoblasts lining bone surfaces and endothelial cells forming the vascular sinuses. Comparison of CTGF and Osterix reporter expression in bone tissue sections indicated an inverse correlation between the strength of CTGF expression and osteoblast maturation. Down-regulation of CTGF reporter expression also occurred during in vitro osteogenic differentiation. Collectively, our studies indicate that CTGF reporter mice selectively identify a subpopulation of bone marrow mesenchymal progenitor cells that reside in the trabecular bone region. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Single Lgr5- or Lgr6-expressing taste stem/progenitor cells generate taste bud cells ex vivo.

    Science.gov (United States)

    Ren, Wenwen; Lewandowski, Brian C; Watson, Jaime; Aihara, Eitaro; Iwatsuki, Ken; Bachmanov, Alexander A; Margolskee, Robert F; Jiang, Peihua

    2014-11-18

    Leucine-rich repeat-containing G protein-coupled receptor 5 (Lgr5) and its homologs (e.g., Lgr6) mark adult stem cells in multiple tissues. Recently, we and others have shown that Lgr5 marks adult taste stem/progenitor cells in posterior tongue. However, the regenerative potential of Lgr5-expressing (Lgr5(+)) cells and the identity of adult taste stem/progenitor cells that regenerate taste tissue in anterior tongue remain elusive. In the present work, we describe a culture system in which single isolated Lgr5(+) or Lgr6(+) cells from taste tissue can generate continuously expanding 3D structures ("organoids"). Many cells within these taste organoids were cycling and positive for proliferative cell markers, cytokeratin K5 and Sox2, and incorporated 5-bromo-2'-deoxyuridine. Importantly, mature taste receptor cells that express gustducin, carbonic anhydrase 4, taste receptor type 1 member 3, nucleoside triphosphate diphosphohydrolase-2, or cytokeratin K8 were present in the taste organoids. Using calcium imaging assays, we found that cells grown out from taste organoids derived from isolated Lgr5(+) cells were functional and responded to tastants in a dose-dependent manner. Genetic lineage tracing showed that Lgr6(+) cells gave rise to taste bud cells in taste papillae in both anterior and posterior tongue. RT-PCR data demonstrated that Lgr5 and Lgr6 may mark the same subset of taste stem/progenitor cells both anteriorly and posteriorly. Together, our data demonstrate that functional taste cells can be generated ex vivo from single Lgr5(+) or Lgr6(+) cells, validating the use of this model for the study of taste cell generation.

  15. Adipogenic placenta-derived mesenchymal stem cells are not lineage restricted by withdrawing extrinsic factors: developing a novel visual angle in stem cell biology.

    Science.gov (United States)

    Hu, C; Cao, H; Pan, X; Li, J; He, J; Pan, Q; Xin, J; Yu, X; Li, J; Wang, Y; Zhu, D; Li, L

    2016-03-17

    Current evidence implies that differentiated bone marrow mesenchymal stem cells (BMMSCs) can act as progenitor cells and transdifferentiate across lineage boundaries. However, whether this unrestricted lineage has specificities depending on the stem cell type is unknown. Placental-derived mesenchymal stem cells (PDMSCs), an easily accessible and less invasive source, are extremely useful materials in current stem cell therapies. No studies have comprehensively analyzed the transition in morphology, surface antigens, metabolism and multilineage potency of differentiated PDMSCs after their dedifferentiation. In this study, we showed that after withdrawing extrinsic factors, adipogenic PDMSCs reverted to a primitive cell population and retained stem cell characteristics. The mitochondrial network during differentiation and dedifferentiation may serve as a marker of absent or acquired pluripotency in various stem cell models. The new population proliferated faster than unmanipulated PDMSCs and could be differentiated into adipocytes, osteocytes and hepatocytes. The cell adhesion molecules (CAMs) signaling pathway and extracellular matrix (ECM) components modulate cell behavior and enable the cells to proliferate or differentiate during the differentiation, dedifferentiation and redifferentiation processes in our study. These observations indicate that the dedifferentiated PDMSCs are distinguishable from the original PDMSCs and may serve as a novel source in stem cell biology and cell-based therapeutic strategies. Furthermore, whether PDMSCs differentiated into other lineages can be dedifferentiated to a primitive cell population needs to be investigated.

  16. Drosophila type II neuroblast lineages keep Prospero levels low to generate large clones that contribute to the adult brain central complex

    Directory of Open Access Journals