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Sample records for early intermediate progenitors

  1. An intermediate level of BMP signaling directly specifies cranial neural crest progenitor cells in zebrafish.

    PubMed

    Schumacher, Jennifer A; Hashiguchi, Megumi; Nguyen, Vu H; Mullins, Mary C

    2011-01-01

    The specification of the neural crest progenitor cell (NCPC) population in the early vertebrate embryo requires an elaborate network of signaling pathways, one of which is the Bone Morphogenetic Protein (BMP) pathway. Based on alterations in neural crest gene expression in zebrafish BMP pathway component mutants, we previously proposed a model in which the gastrula BMP morphogen gradient establishes an intermediate level of BMP activity establishing the future NCPC domain. Here, we tested this model and show that an intermediate level of BMP signaling acts directly to specify the NCPC. We quantified the effects of reducing BMP signaling on the number of neural crest cells and show that neural crest cells are significantly increased when BMP signaling is reduced and that this increase is not due to an increase in cell proliferation. In contrast, when BMP signaling is eliminated, NCPC fail to be specified. We modulated BMP signaling levels in BMP pathway mutants with expanded or no NCPCs to demonstrate that an intermediate level of BMP signaling specifies the NCPC. We further investigated the ability of Smad5 to act in a graded fashion by injecting smad5 antisense morpholinos and show that increasing doses first expand the NCPCs and then cause a loss of NCPCs, consistent with Smad5 acting directly in neural crest progenitor specification. Using Western blot analysis, we show that P-Smad5 levels are dose-dependently reduced in smad5 morphants, consistent with an intermediate level of BMP signaling acting through Smad5 to specify the neural crest progenitors. Finally, we performed chimeric analysis to demonstrate for the first time that BMP signal reception is required directly by NCPCs for their specification. Together these results add substantial evidence to a model in which graded BMP signaling acts as a morphogen to pattern the ectoderm, with an intermediate level acting in neural crest specification.

  2. Transcriptional regulation of intermediate progenitor cell generation during hippocampal development

    PubMed Central

    Harris, Lachlan; Zalucki, Oressia; Gobius, Ilan; McDonald, Hannah; Osinki, Jason; Harvey, Tracey J.; Essebier, Alexandra; Vidovic, Diana; Gladwyn-Ng, Ivan; Burne, Thomas H.; Heng, Julian I.; Richards, Linda J.; Gronostajski, Richard M.

    2016-01-01

    During forebrain development, radial glia generate neurons through the production of intermediate progenitor cells (IPCs). The production of IPCs is a central tenet underlying the generation of the appropriate number of cortical neurons, but the transcriptional logic underpinning this process remains poorly defined. Here, we examined IPC production using mice lacking the transcription factor nuclear factor I/X (Nfix). We show that Nfix deficiency delays IPC production and prolongs the neurogenic window, resulting in an increased number of neurons in the postnatal forebrain. Loss of additional Nfi alleles (Nfib) resulted in a severe delay in IPC generation while, conversely, overexpression of NFIX led to precocious IPC generation. Mechanistically, analyses of microarray and ChIP-seq datasets, coupled with the investigation of spindle orientation during radial glial cell division, revealed that NFIX promotes the generation of IPCs via the transcriptional upregulation of inscuteable (Insc). These data thereby provide novel insights into the mechanisms controlling the timely transition of radial glia into IPCs during forebrain development. PMID:27965439

  3. WDR62 Regulates Early Neural and Glial Progenitor Specification of Human Pluripotent Stem Cells

    PubMed Central

    Alshawaf, Abdullah J.; Antonic, Ana; Skafidas, Efstratios

    2017-01-01

    Mutations in WD40-repeat protein 62 (WDR62) are commonly associated with primary microcephaly and other developmental cortical malformations. We used human pluripotent stem cells (hPSC) to examine WDR62 function during human neural differentiation and model early stages of human corticogenesis. Neurospheres lacking WDR62 expression showed decreased expression of intermediate progenitor marker, TBR2, and also glial marker, S100β. In contrast, inhibition of c-Jun N-terminal kinase (JNK) signalling during hPSC neural differentiation induced upregulation of WDR62 with a corresponding increase in neural and glial progenitor markers, PAX6 and EAAT1, respectively. These findings may signify a role of WDR62 in specifying intermediate neural and glial progenitors during human pluripotent stem cell differentiation. PMID:28690640

  4. Brain tumor specifies intermediate progenitor cell identity by attenuating β-catenin/Armadillo activity

    PubMed Central

    Komori, Hideyuki; Xiao, Qi; McCartney, Brooke M.; Lee, Cheng-Yu

    2014-01-01

    During asymmetric stem cell division, both the daughter stem cell and the presumptive intermediate progenitor cell inherit cytoplasm from their parental stem cell. Thus, proper specification of intermediate progenitor cell identity requires an efficient mechanism to rapidly extinguish the activity of self-renewal factors, but the mechanisms remain unknown in most stem cell lineages. During asymmetric division of a type II neural stem cell (neuroblast) in the Drosophila larval brain, the Brain tumor (Brat) protein segregates unequally into the immature intermediate neural progenitor (INP), where it specifies INP identity by attenuating the function of the self-renewal factor Klumpfuss (Klu), but the mechanisms are not understood. Here, we report that Brat specifies INP identity through its N-terminal B-boxes via a novel mechanism that is independent of asymmetric protein segregation. Brat-mediated specification of INP identity is critically dependent on the function of the Wnt destruction complex, which attenuates the activity of β-catenin/Armadillo (Arm) in immature INPs. Aberrantly increasing Arm activity in immature INPs further exacerbates the defects in the specification of INP identity and enhances the supernumerary neuroblast mutant phenotype in brat mutant brains. By contrast, reducing Arm activity in immature INPs suppresses supernumerary neuroblast formation in brat mutant brains. Finally, reducing Arm activity also strongly suppresses supernumerary neuroblasts induced by overexpression of klu. Thus, the Brat-dependent mechanism extinguishes the function of the self-renewal factor Klu in the presumptive intermediate progenitor cell by attenuating Arm activity, balancing stem cell maintenance and progenitor cell specification. PMID:24257623

  5. Discovery, Progenitor and Early Evolution of a Stripped Envelope Supernova iPTF13bvn

    NASA Astrophysics Data System (ADS)

    Cao, Yi; Kasliwal, Mansi M.; Arcavi, Iair; Horesh, Assaf; Hancock, Paul; Valenti, Stefano; Cenko, S. Bradley; Kulkarni, S. R.; Gal-Yam, Avishay; Gorbikov, Evgeny; Ofek, Eran O.; Sand, David; Yaron, Ofer; Graham, Melissa; Silverman, Jeffrey M.; Wheeler, J. Craig; Marion, G. H.; Walker, Emma S.; Mazzali, Paolo; Howell, D. Andrew; Li, K. L.; Kong, A. K. H.; Bloom, Joshua S.; Nugent, Peter E.; Surace, Jason; Masci, Frank; Carpenter, John; Degenaar, Nathalie; Gelino, Christopher R.

    2013-09-01

    The intermediate Palomar Transient Factory reports our discovery of a young supernova, iPTF13bvn, in the nearby galaxy, NGC 5806 (22.5 Mpc). Our spectral sequence in the optical and infrared suggests a Type Ib classification. We identify a blue progenitor candidate in deep pre-explosion imaging within a 2σ error circle of 80 mas (8.7 pc). The candidate has an MB luminosity of -5.52 ± 0.39 mag and a B - I color of 0.25 ± 0.25 mag. If confirmed by future observations, this would be the first direct detection for a progenitor of a Type Ib. Fitting a power law to the early light curve, we find an extrapolated explosion date around 0.6 days before our first detection. We see no evidence of shock cooling. The pre-explosion detection limits constrain the radius of the progenitor to be smaller than a few solar radii. iPTF13bvn is also detected in centimeter and millimeter wavelengths. Fitting a synchrotron self-absorption model to our radio data, we find a mass-loading parameter of 1.3×1012 g cm-1. Assuming a wind velocity of 103 km s-1, we derive a progenitor mass-loss rate of 3 × 10-5 M ⊙ yr-1. Our observations, taken as a whole, are consistent with a Wolf-Rayet progenitor of the supernova iPTF13bvn.

  6. Early patterning and specification of cardiac progenitors in gastrulating mesoderm

    PubMed Central

    Devine, W Patrick; Wythe, Joshua D; George, Matthew; Koshiba-Takeuchi, Kazuko; Bruneau, Benoit G

    2014-01-01

    Mammalian heart development requires precise allocation of cardiac progenitors. The existence of a multipotent progenitor for all anatomic and cellular components of the heart has been predicted but its identity and contribution to the two cardiac progenitor ‘fields’ has remained undefined. Here we show, using clonal genetic fate mapping, that Mesp1+ cells in gastrulating mesoderm are rapidly specified into committed cardiac precursors fated for distinct anatomic regions of the heart. We identify Smarcd3 as a marker of early specified cardiac precursors and identify within these precursors a compartment boundary at the future junction of the left and right ventricles that arises prior to morphogenesis. Our studies define the timing and hierarchy of cardiac progenitor specification and demonstrate that the cellular and anatomical fate of mesoderm-derived cardiac cells is specified very early. These findings will be important to understand the basis of congenital heart defects and to derive cardiac regeneration strategies. DOI: http://dx.doi.org/10.7554/eLife.03848.001 PMID:25296024

  7. GATA-3 is required for early T lineage progenitor development

    PubMed Central

    Hosoya, Tomonori; Kuroha, Takashi; Moriguchi, Takashi; Cummings, Dustin; Maillard, Ivan; Lim, Kim-Chew

    2009-01-01

    Most T lymphocytes appear to arise from very rare early T lineage progenitors (ETPs) in the thymus, but the transcriptional programs that specify ETP generation are not completely known. The transcription factor GATA-3 is required for the development of T lymphocytes at multiple late differentiation steps as well as for the development of thymic natural killer cells. However, a role for GATA-3 before the double-negative (DN) 3 stage of T cell development has to date been obscured both by the developmental heterogeneity of DN1 thymocytes and the paucity of ETPs. We provide multiple lines of in vivo evidence through the analysis of T cell development in Gata3 hypomorphic mutant embryos, in irradiated mice reconstituted with Gata3 mutant hematopoietic cells, and in mice conditionally ablated for the Gata3 gene to show that GATA-3 is required for ETP generation. We further show that Gata3 loss does not affect hematopoietic stem cells or multipotent hematopoietic progenitors. Finally, we demonstrate that Gata3 mutant lymphoid progenitors exhibit neither increased apoptosis nor diminished cell-cycle progression. Thus, GATA-3 is required for the cell-autonomous development of the earliest characterized thymic T cell progenitors. PMID:19934022

  8. Generation of an expandable intermediate mesoderm restricted progenitor cell line from human pluripotent stem cells

    PubMed Central

    Kumar, Nathan; Richter, Jenna; Cutts, Josh; Bush, Kevin T; Trujillo, Cleber; Nigam, Sanjay K; Gaasterland, Terry; Brafman, David; Willert, Karl

    2015-01-01

    The field of tissue engineering entered a new era with the development of human pluripotent stem cells (hPSCs), which are capable of unlimited expansion whilst retaining the potential to differentiate into all mature cell populations. However, these cells harbor significant risks, including tumor formation upon transplantation. One way to mitigate this risk is to develop expandable progenitor cell populations with restricted differentiation potential. Here, we used a cellular microarray technology to identify a defined and optimized culture condition that supports the derivation and propagation of a cell population with mesodermal properties. This cell population, referred to as intermediate mesodermal progenitor (IMP) cells, is capable of unlimited expansion, lacks tumor formation potential, and, upon appropriate stimulation, readily acquires properties of a sub-population of kidney cells. Interestingly, IMP cells fail to differentiate into other mesodermally-derived tissues, including blood and heart, suggesting that these cells are restricted to an intermediate mesodermal fate. DOI: http://dx.doi.org/10.7554/eLife.08413.001 PMID:26554899

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

    PubMed Central

    Keisler, Jessica L.; Pérez-Millán, María I.; Schade, Vanessa; Camper, Sally A.

    2016-01-01

    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. PMID:26812162

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

    PubMed

    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.

  11. Epigenetic Marks Define the Lineage and Differentiation Potential of Two Distinct Neural Crest-Derived Intermediate Odontogenic Progenitor Populations

    PubMed Central

    Gopinathan, Gokul; Kolokythas, Antonia

    2013-01-01

    Epigenetic mechanisms, such as histone modifications, play an active role in the differentiation and lineage commitment of mesenchymal stem cells. In the present study, epigenetic states and differentiation profiles of two odontogenic neural crest-derived intermediate progenitor populations were compared: dental pulp (DP) and dental follicle (DF). ChIP on chip assays revealed substantial H3K27me3-mediated repression of odontoblast lineage genes DSPP and dentin matrix protein 1 (DMP1) in DF cells, but not in DP cells. Mineralization inductive conditions caused steep increases of mineralization and patterning gene expression levels in DP cells when compared to DF cells. In contrast, mineralization induction resulted in a highly dynamic histone modification response in DF cells, while there was only a subdued effect in DP cells. Both DF and DP progenitors featured H3K4me3-active marks on the promoters of early mineralization genes RUNX2, MSX2, and DLX5, while OSX, IBSP, and BGLAP promoters were enriched for H3K9me3 or H3K27me3. Compared to DF cells, DP cells expressed higher levels of three pluripotency-associated genes, OCT4, NANOG, and SOX2. Finally, gene ontology comparison of bivalent marks unique for DP and DF cells highlighted cell–cell attachment genes in DP cells and neurogenesis genes in DF cells. In conclusion, the present study indicates that the DF intermediate odontogenic neural crest lineage is distinguished from its DP counterpart by epigenetic repression of DSPP and DMP1 genes and through dynamic histone enrichment responses to mineralization induction. Findings presented here highlight the crucial role of epigenetic regulatory mechanisms in the terminal differentiation of odontogenic neural crest lineages. PMID:23379639

  12. Lin28 sustains early renal progenitors and induces Wilms tumor

    PubMed Central

    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

  13. Archival Investigation of Outburst Sites and Progenitors of Extragalactic Intermediate-Luminosity Mid-IR Transients

    NASA Astrophysics Data System (ADS)

    Bond, Howard

    2017-08-01

    Our team is using Spitzer in a long-term search for extragalactic mid-infrared (MIR) variable stars and transients-the SPIRITS project (SPitzer InfraRed Intensive Transients Survey). In this first exploration of luminous astrophysical transients in the infrared, we have discovered a puzzling new class. We call them SPRITEs: eSPecially Red Intermediate-luminosity Transient Events. They have maximum MIR luminosities between supernovae and classical novae, but are not detected in the optical to deep limits. To date, we have discovered more than 50 SPRITEs in galaxies out to 17 Mpc. In this Archival Research proposal, we request support in order to investigate the pre-eruption sites in HST images of some 3 dozen SPRITEs discovered to date, and an additional 2 dozen that we are likely to find until the end of Spitzer observing in late 2018. Our aims are (1) characterize the pre-outburst environments at HST resolution in the visible and near-IR, to understand the stellar populations, stellar ages and masses, and interstellar medium at the outburst sites; (2) search for progenitors; (3) help prepare the way for a better understanding of the nature of extragalactic IR transients that will be investigated by JWST.

  14. The Drosophila Sp8 transcription factor Buttonhead prevents premature differentiation of intermediate neural progenitors

    PubMed Central

    Xie, Yonggang; Li, Xiaosu; Zhang, Xian; Mei, Shaolin; Li, Hongyu; Urso, Andreacarola; Zhu, Sijun

    2014-01-01

    Intermediate neural progenitor cells (INPs) need to avoid differentiation and cell cycle exit while maintaining restricted developmental potential, but mechanisms preventing differentiation and cell cycle exit of INPs are not well understood. In this study, we report that the Drosophila homolog of mammalian Sp8 transcription factor Buttonhead (Btd) prevents premature differentiation and cell cycle exit of INPs in Drosophila larval type II neuroblast (NB) lineages. We show that the loss of Btd leads to elimination of mature INPs due to premature differentiation of INPs into terminally dividing ganglion mother cells. We provide evidence to demonstrate that Btd prevents the premature differentiation by suppressing the expression of the homeodomain protein Prospero in immature INPs. We further show that Btd functions cooperatively with the Ets transcription factor Pointed P1 to promote the generation of INPs. Thus, our work reveals a critical mechanism that prevents premature differentiation and cell cycle exit of Drosophila INPs. DOI: http://dx.doi.org/10.7554/eLife.03596.001 PMID:25285448

  15. Intermediate progenitors are increased by lengthening of the cell cycle through calcium signaling and p53 expression in human neural progenitors

    PubMed Central

    García-García, Elisa; Pino-Barrio, María José; López-Medina, Laura; Martínez-Serrano, Alberto

    2012-01-01

    During development, neurons can be generated directly from a multipotent progenitor or indirectly through an intermediate progenitor (IP). This last mode of division amplifies the progeny of neurons. The mechanisms governing the generation and behavior of IPs are not well understood. In this work, we demonstrate that the lengthening of the cell cycle enhances the generation of neurons in a human neural progenitor cell system in vitro and also the generation and expansion of IPs. These IPs are insulinoma-associated 1 (Insm1)+/BTG family member 2 (Btg2)−, which suggests an increase in a self-amplifying IP population. Later the cultures express neurogenin 2 (Ngn2) and become neurogenic. The signaling responsible for this cell cycle modulation is investigated. It is found that the release of calcium from the endoplasmic reticulum to the cytosol in response to B cell lymphoma-extra large overexpression or ATP addition lengths the cell cycle and increases the number of IPs and, in turn, the final neuron outcome. Moreover, data suggest that the p53–p21 pathway is responsible for the changes in cell cycle. In agreement with this, increased p53 levels are necessary for a calcium-induced increase in neurons. Our findings contribute to understand how calcium signaling can modulate cell cycle length during neurogenesis. PMID:22323293

  16. Protein Tyrosine Phosphatase PRL2 Mediates Notch and Kit Signals in Early T Cell Progenitors.

    PubMed

    Kobayashi, Michihiro; Nabinger, Sarah C; Bai, Yunpeng; Yoshimoto, Momoko; Gao, Rui; Chen, Sisi; Yao, Chonghua; Dong, Yuanshu; Zhang, Lujuan; Rodriguez, Sonia; Yashiro-Ohtani, Yumi; Pear, Warren S; Carlesso, Nadia; Yoder, Mervin C; Kapur, Reuben; Kaplan, Mark H; Daniel Lacorazza, Hugo; Zhang, Zhong-Yin; Liu, Yan

    2017-04-01

    The molecular pathways regulating lymphoid priming, fate, and development of multipotent bone marrow hematopoietic stem and progenitor cells (HSPCs) that continuously feed thymic progenitors remain largely unknown. While Notch signal is indispensable for T cell specification and differentiation, the downstream effectors are not well understood. PRL2, a protein tyrosine phosphatase that regulates hematopoietic stem cell proliferation and self-renewal, is highly expressed in murine thymocyte progenitors. Here we demonstrate that protein tyrosine phosphatase PRL2 and receptor tyrosine kinase c-Kit are critical downstream targets and effectors of the canonical Notch/RBPJ pathway in early T cell progenitors. While PRL2 deficiency resulted in moderate defects of thymopoiesis in the steady state, de novo generation of T cells from Prl2 null hematopoietic stem cells was significantly reduced following transplantation. Prl2 null HSPCs also showed impaired T cell differentiation in vitro. We found that Notch/RBPJ signaling upregulated PRL2 as well as c-Kit expression in T cell progenitors. Further, PRL2 sustains Notch-mediated c-Kit expression and enhances stem cell factor/c-Kit signaling in T cell progenitors, promoting effective DN1-DN2 transition. Thus, we have identified a critical role for PRL2 phosphatase in mediating Notch and c-Kit signals in early T cell progenitors. Stem Cells 2017;35:1053-1064. © 2016 AlphaMed Press.

  17. Identifying the progenitors of present-day early-type galaxies in observational surveys: correcting `progenitor bias' using the Horizon-AGN simulation

    NASA Astrophysics Data System (ADS)

    Martin, G.; Kaviraj, S.; Devriendt, J. E. G.; Dubois, Y.; Pichon, C.; Laigle, C.

    2018-03-01

    As endpoints of the hierarchical mass-assembly process, the stellar populations of local early-type galaxies encode the assembly history of galaxies over cosmic time. We use Horizon-AGN, a cosmological hydrodynamical simulation, to study the merger histories of local early-type galaxies and track how the morphological mix of their progenitors evolves over time. We provide a framework for alleviating `progenitor bias' - the bias that occurs if one uses only early-type galaxies to study the progenitor population. Early types attain their final morphology at relatively early epochs - by z ˜ 1, around 60 per cent of today's early types have had their last significant merger. At all redshifts, the majority of mergers have one late-type progenitor, with late-late mergers dominating at z > 1.5 and early-early mergers becoming significant only at z < 0.5. Progenitor bias is severe at all but the lowest redshifts - e.g. at z ˜ 0.6, less than 50 per cent of the stellar mass in today's early types is actually in progenitors with early-type morphology, while, at z ˜ 2, studying only early types misses almost all (80 per cent) of the stellar mass that eventually ends up in local early-type systems. At high redshift, almost all massive late-type galaxies, regardless of their local environment or star formation rate, are progenitors of local early-type galaxies, as are lower mass (M⋆ < 1010.5 M_{⊙}) late-types as long as they reside in high-density environments. In this new era of large observational surveys (e.g. LSST, JWST), this study provides a framework for studying how today's early-type galaxies have been built up over cosmic time.

  18. Investigation of early molybdopterin biosynthetic intermediates

    SciTech Connect

    Wuebbens, M.M.; Rajagopalan, K.V.

    1991-03-11

    Little information is available regarding the early steps in the biosynthetic pathway of molybdopterin (MPT). In order to explore these early reactions, and in particular to investigate the origin of the ring and side chain carbons of MPT, a metabolic approach employing the incorporation of {sup 14}C label was chosen. This method was facilitated by the recent purification and characterization of desulfomolybdopterin 2{prime},4{prime}-cyclic phosphate, the precursor which is converted directly to active molybdopterin in Escherichia coli by the addition of vicinal sulfurs to the side chain. This labile precursor readily oxidizes to Compound Z, a stable 6-alkyl pterin which retainsmore » all of the carbon atoms present in molybdopterin. Compound Z, rather than molybdopterin itself was chosen as the end product for labeling due to its overproduction in some MPT-deficient strains, as well as its stability and ease of purification. The authors report here the isolation of {sup 14}C-labelled Compound Z from E.coli chlN cells cultured in minimal media supplemented with U-{sup 14}C guanosine. Successive cleavage of the side chain carbons by permanganate treatment and UV light produced a decrease in the specific radioactivity of the resulting pterins. These data indicate that the early portion of the molybdopterin biosynthetic pathway may be similar to that of the bioactive pterins folate and biopterin, both of which are derived from guanosine triphosphate.« less

  19. KDR (VEGFR2) identifies a conserved human and murine hepatic progenitor and instructs early liver development

    PubMed Central

    Goldman, Orit; Han, Songyan; Sourrisseau, Marion; Dziedzic, Noelle; Hamou, Wissam; Corneo, Barbara; D’Souza, Sunita; Sato, Thomas; Kotton, Darrell N.; Bissig, Karl-Dimiter; Kalir, Tamara; Jacobs, Adam; Evans, Todd; Evans, Matthew J.; Gouon-Evans, Valerie

    2013-01-01

    SUMMARY Understanding the fetal hepatic niche is essential for optimizing the generation of functional hepatocyte-like (hepatic) cells from human embryonic stem cells (hESCs). Here, we show that KDR (VEGFR2), previously assumed to be mostly restricted to mesodermal lineages, marks a hESC-derived hepatic progenitor. hESC-derived endoderm cells do not express KDR, but when cultured in media supporting hepatic differentiation, generate KDR+ hepatic progenitors and KDR- hepatic cells. KDR+ progenitors require active KDR signaling both to instruct their own differentiation into hepatic cells, and to support non-cell-autonomously the functional maturation of co-cultured KDR- hepatic cells. Analysis of human fetal livers suggests that similar progenitors are present in human livers. Lineage tracing in mice provides in vivo evidence of a KDR+ hepatic progenitor for fetal hepatoblasts and subsequently adult hepatocytes and cholangiocytes. Altogether, our findings reveal that KDR is a conserved marker for endoderm-derived hepatic progenitors, and a functional receptor instructing early liver development. PMID:23746980

  20. WT1 controls antagonistic FGF and BMP-pSMAD pathways in early renal progenitors.

    PubMed

    Motamedi, Fariba Jian; Badro, Danielle A; Clarkson, Michael; Lecca, M Rita; Bradford, Stephen T; Buske, Fabian A; Saar, Kathrin; Hübner, Norbert; Brändli, André W; Schedl, Andreas

    2014-07-17

    Kidney organogenesis requires the tight control of proliferation, differentiation and apoptosis of renal progenitor cells. How the balance between these cellular decisions is achieved remains elusive. The Wilms' tumour suppressor Wt1 is required for progenitor survival, but the molecular cause for renal agenesis in mutants is poorly understood. Here we demonstrate that lack of Wt1 abolishes fibroblast growth factor (FGF) and induces BMP/pSMAD signalling within the metanephric mesenchyme. Addition of recombinant FGFs or inhibition of pSMAD signalling rescues progenitor cell apoptosis induced by the loss of Wt1. We further show that recombinant BMP4, but not BMP7, induces an apoptotic response within the early kidney that can be suppressed by simultaneous addition of FGFs. These data reveal a hitherto unknown sensitivity of early renal progenitors to pSMAD signalling, establishes FGF and pSMAD signalling as antagonistic forces in early kidney development and places WT1 as a key regulator of pro-survival FGF signalling pathway genes.

  1. Monoamine Oxidases Regulate Telencephalic Neural Progenitors in Late Embryonic and Early Postnatal Development

    PubMed Central

    Cheng, Aiwu; Scott, Anna L.; Ladenheim, Bruce; Chen, Kevin; Ouyang, Xin; Lathia, Justin D.; Mughal, Mohamed; Cadet, Jean Lud; Mattson, Mark P.; Shih, Jean C.

    2010-01-01

    Monoamine neurotransmitters play major roles in regulating a range of brain functions in adults and increasing evidence suggests roles for monoamines in brain development. Here we show that mice lacking the monoamine metabolic enzymes MAO A and MAO B (MAO AB-deficient mice) exhibit diminished proliferation of neural stem cells (NSC) in the developing telencephalon beginning in late gestation [embryonic day (E) 17.5], a deficit that persists in neonatal and adult mice. These mice showed significantly increased monoamine levels and anxiety-like behaviors as adults. Assessments of markers of intermediate progenitor cells (IPC) and mitosis showed that NSC in the subventricular zone (SVZ), but not in the ventricular zone, are reduced in MAO AB-deficient mice. A developmental time course of monoamines in frontal cortical tissues revealed increased serotonin levels as early as E14.5, and a further large increase was found between E17.5 and postnatal day 2. Administration of an inhibitor of serotonin synthesis (parachlorophenylalanine) between E14.5 and E19.5 restored the IPC numbers and SVZ thickness, suggesting the role of serotonin in the suppression of IPC proliferation. Studies of neurosphere cultures prepared from the telencephalon at different embryonic and postnatal ages showed that serotonin stimulates proliferation in wild-type, but not in MAO AB-deficient, NSC. Together, these results suggest that a MAO-dependent long-lasting alteration in the proliferation capacity of NSC occurs late in embryonic development and is mediated by serotonin. Our findings reveal novel roles for MAOs and serotonin in the regulation of IPC proliferation in the developing brain. PMID:20702706

  2. A Population of Progenitor Cells in the Basal and Intermediate Layers of the Murine Bladder Urothelium Contributes to Urothelial Development and Regeneration

    PubMed Central

    Colopy, Sara A.; Bjorling, Dale E.; Mulligan, William A.; Bushman, Wade

    2014-01-01

    Background Homeostatic maintenance and repair of the bladder urothelium has been attributed to proliferation of keratin 5-expressing basal cells (K5-BC) with subsequent differentiation into superficial cells. Recent evidence, however, suggests that the intermediate cell layer harbors a population of progenitor cells. We use label-retaining cell (LRC) methodology in conjunction with a clinically relevant model of uropathogenic Escherichia coli (UPEC)-induced injury to characterize urothelial ontogeny during development and in response to diffuse urothelial injury. Results In the developing urothelium, proliferating cells were dispersed throughout the K5-BC and intermediate cells layers, becoming progressively concentrated in the K5-BC layer with age. When 5-bromo-2-deoxyuridine (BrdU) was administered during urothelial development, LRCs in the adult were found within the K5-BC, intermediate, and superficial cell layers, the location dependent upon time of labeling. UPEC inoculation resulted in loss of the superficial cell layer followed by robust proliferation of K5-BCs and intermediate cells. LRCs within the K5-BC and intermediate cell layers proliferated in response to injury. Conclusions Urothelial development and regeneration following injury relies on proliferation of K5-BC and intermediate cells. The existence and proliferation of LRCs within both the K5-BC and intermediate cell layers suggests the presence of two populations of urothelial progenitor cells. PMID:24796293

  3. Supernova 2012ec: identification of the progenitor and early monitoring with PESSTO

    NASA Astrophysics Data System (ADS)

    Maund, J. R.; Fraser, M.; Smartt, S. J.; Botticella, M. T.; Barbarino, C.; Childress, M.; Gal-Yam, A.; Inserra, C.; Pignata, G.; Reichart, D.; Schmidt, B.; Sollerman, J.; Taddia, F.; Tomasella, L.; Valenti, S.; Yaron, O.

    2013-04-01

    We present the identification of the progenitor of the Type IIP SN 2012ec in archival pre-explosion Hubble Space Telescope Wide Field Planetary Camera 2 (WFPC2) and Advanced Camera for Surveys Wide Field Channel F814W images. The properties of the progenitor are further constrained by non-detections in pre-explosion WFPC2 F450W and F606W images. We report a series of early photometric and spectroscopic observations of SN 2012ec. The r'-band light curve shows a plateau with M_{r^' }}=-17.0. The early spectrum is similar to the Type IIP SN 1999em, with the expansion velocity measured at Hα absorption minimum of -11 700 km s-1 (at 1 d post-discovery). The photometric and spectroscopic evolution of SN 2012ec shows it to be a Type IIP SN, discovered only a few days post-explosion (<6 d). We derive a luminosity for the progenitor, in comparison with MARCS model spectral energy distributions, of log {L/L}_{⊙} = 5.15± 0.19, from which we infer an initial mass range of 14-22 M⊙. This is the first SN with an identified progenitor to be followed by the Public ESO Spectroscopic Survey of Transient Objects (PESSTO).

  4. Shear stress upregulates regeneration-related immediate early genes in liver progenitors in 3D ECM-like microenvironments.

    PubMed

    Nishii, Kenichiro; Brodin, Erik; Renshaw, Taylor; Weesner, Rachael; Moran, Emma; Soker, Shay; Sparks, Jessica L

    2018-05-01

    The role of fluid stresses in activating the hepatic stem/progenitor cell regenerative response is not well understood. This study hypothesized that immediate early genes (IEGs) with known links to liver regeneration will be upregulated in liver progenitor cells (LPCs) exposed to in vitro shear stresses on the order of those produced from elevated interstitial flow after partial hepatectomy. The objectives were: (1) to develop a shear flow chamber for application of fluid stress to LPCs in 3D culture; and (2) to determine the effects of fluid stress on IEG expression in LPCs. Two hours of shear stress exposure at ∼4 dyn/cm 2 was applied to LPCs embedded individually or as 3D spheroids within a hyaluronic acid/collagen I hydrogel. Results were compared against static controls. Quantitative reverse transcriptase polymerase chain reaction was used to evaluate the effect of experimental treatments on gene expression. Twenty-nine genes were analyzed, including IEGs and other genes linked to liver regeneration. Four IEGs (CFOS, IP10, MKP1, ALB) and three other regeneration-related genes (WNT, VEGF, EpCAM) were significantly upregulated in LPCs in response to fluid mechanical stress. LPCs maintained an early to intermediate stage of differentiation in spheroid culture in the absence of the hydrogel, and addition of the gel initiated cholangiocyte differentiation programs which were abrogated by the onset of flow. Collectively the flow-upregulated genes fit the pattern of an LPC-mediated proliferative/regenerative response. These results suggest that fluid stresses are potentially important regulators of the LPC-mediated regeneration response in liver. © 2017 Wiley Periodicals, Inc.

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

    PubMed

    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.

  6. Immunohistochemical Markers of Neural Progenitor Cells in the Early Embryonic Human Cerebral Cortex

    PubMed Central

    Vinci, L.; Ravarino, A.; Fanos, V.; Naccarato, A.G.; Senes, G.; Gerosa, C.; Bevilacqua, G.; Faa, G.; Ambu, R.

    2016-01-01

    The development of the human central nervous system represents a delicate moment of embryogenesis. The purpose of this study was to analyze the expression of multiple immunohistochemical markers in the stem/progenitor cells in the human cerebral cortex during the early phases of development. To this end, samples from cerebral cortex were obtained from 4 human embryos of 11 weeks of gestation. Each sample was formalin-fixed, paraffin embedded and immunostained with several markers including GFAP, WT1, Nestin, Vimentin, CD117, S100B, Sox2, PAX2, PAX5, Tβ4, Neurofilament, CD44, CD133, Synaptophysin and Cyclin D1. Our study shows the ability of the different immunohistochemical markers to evidence different zones of the developing human cerebral cortex, allowing the identification of the multiple stages of differentiation of neuronal and glial precursors. Three important markers of radial glial cells are evidenced in this early gestational age: Vimentin, Nestin and WT1. Sox2 was expressed by the stem/progenitor cells of the ventricular zone, whereas the postmitotic neurons of the cortical plate were immunostained by PAX2 and NSE. Future studies are needed to test other important stem/progenitor cells markers and to better analyze differences in the immunohistochemical expression of these markers during gestation. PMID:26972711

  7. Early Blue Excess from the Type Ia Supernova 2017cbv and Implications for Its Progenitor

    NASA Astrophysics Data System (ADS)

    Hosseinzadeh, Griffin; Sand, David J.; Valenti, Stefano; Brown, Peter; Howell, D. Andrew; McCully, Curtis; Kasen, Daniel; Arcavi, Iair; Azalee Bostroem, K.; Tartaglia, Leonardo; Hsiao, Eric Y.; Davis, Scott; Shahbandeh, Melissa; Stritzinger, Maximilian D.

    2017-08-01

    We present very early, high-cadence photometric observations of the nearby Type Ia SN 2017cbv. The light curve is unique in that it has a blue bump during the first five days of observations in the U, B, and g bands, which is clearly resolved given our photometric cadence of 5.7 hr during that time span. We model the light curve as the combination of early shocking of the supernova ejecta against a nondegenerate companion star plus a standard SN Ia component. Our best-fit model suggests the presence of a subgiant star 56 R ⊙ from the exploding white dwarf, although this number is highly model-dependent. While this model matches the optical light curve well, it overpredicts the observed flux in the ultraviolet bands. This may indicate that the shock is not a blackbody, perhaps because of line blanketing in the UV. Alternatively, it could point to another physical explanation for the optical blue bump, such as interaction with circumstellar material or an unusual nickel distribution. Early optical spectra of SN 2017cbv show strong carbon (C II λ6580) absorption up through day -13 with respect to maximum light, suggesting that the progenitor system contains a significant amount of unburned material. These early results on SN 2017cbv illustrate the power of early discovery and intense follow-up of nearby supernovae to resolve standing questions about the progenitor systems and explosion mechanisms of SNe Ia.

  8. Early Blue Excess from the Type Ia Supernova 2017cbv and Implications for Its Progenitor

    SciTech Connect

    Hosseinzadeh, Griffin; Howell, D. Andrew; McCully, Curtis

    We present very early, high-cadence photometric observations of the nearby Type Ia SN 2017cbv. The light curve is unique in that it has a blue bump during the first five days of observations in the U , B , and g bands, which is clearly resolved given our photometric cadence of 5.7 hr during that time span. We model the light curve as the combination of early shocking of the supernova ejecta against a nondegenerate companion star plus a standard SN Ia component. Our best-fit model suggests the presence of a subgiant star 56 R {sub ☉} from the explodingmore » white dwarf, although this number is highly model-dependent. While this model matches the optical light curve well, it overpredicts the observed flux in the ultraviolet bands. This may indicate that the shock is not a blackbody, perhaps because of line blanketing in the UV. Alternatively, it could point to another physical explanation for the optical blue bump, such as interaction with circumstellar material or an unusual nickel distribution. Early optical spectra of SN 2017cbv show strong carbon (C ii λ 6580) absorption up through day −13 with respect to maximum light, suggesting that the progenitor system contains a significant amount of unburned material. These early results on SN 2017cbv illustrate the power of early discovery and intense follow-up of nearby supernovae to resolve standing questions about the progenitor systems and explosion mechanisms of SNe Ia.« less

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

    PubMed

    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, p<0.001). Portal inflammation correlated with CK-7-counted putative hepatic progenitor cells (r=0.48, p<0.001), intermediate hepatobiliary cells (r=0.6, p<0.001) and bile ductules/interlobular bile ducts (r=0.6, p<0.001), and with the activity of myofibroblasts (r=0.5, p<0.001). Correlations were confirmed when elements were counted by immunostaining for CK-19 and EpCAM. Lobular inflammation, ballooning, myofibroblast activity and hepatic progenitor cell 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

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

    PubMed Central

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

    2011-01-01

    SUMMARY 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 (Neurog3CreERT/+) and Neurog3-deficient (Neurog3CreERT/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 single bipotent progenitor already committed to the duct/endocrine lineages and not from domain of cells having both potentialities. PMID:22056785

  11. Decursin inhibits vasculogenesis in early tumor progression by suppression of endothelial progenitor cell differentiation and function.

    PubMed

    Jung, Seok Yun; Choi, Jin Hwa; Kwon, Sang-Mo; Masuda, Haruchika; Asahara, Takayuki; Lee, You-Mie

    2012-05-01

    Endothelial progenitor cells (EPCs) contribute to the tumor vasculature during tumor progression. Decursin isolated from the herb Angelica gigas is known to possess potent anti-inflammatory activities. Recently, we reported that decursin is a novel candidate for an angiogenesis inhibitor [Jung et al., 2009]. In this study, we investigated whether decursin regulates EPC differentiation and function to inhibit tumor vasculogenesis. We isolated AC133+ cells from human cord blood and decursin significantly decreased the number of EPC colony forming units of human cord blood-derived AC133+ cells that produce functional EPC progenies. Decursin dose-dependently decreased the cell number of EPC committing cells as demonstrated by EPC expansion studies. Decursin inhibited EPC differentiation from progenitor cells into spindle-shaped EPC colonies. Additionally, decursin inhibited proliferation and migration of early EPCs isolated from mouse bone marrow. Furthermore, decursin suppressed expression of angiopoietin-2, angiopoietin receptor Tie-2, Flk-1 (vascular endothelial growth factor receptor-2), and endothelial nitric oxide synthase in mouse BM derived EPCs in a dose-dependent manner. Decursin suppressed tube formation ability of EPCs in collaboration with HUVEC. Decursin (4 mg/kg) inhibited tumor-induced mobilization of circulating EPCs (CD34 + /VEGFR-2+ cells) from bone marrow and early incorporation of Dil-Ac-LDL-labeled or green fluorescent protein (GFP)+ EPCs into neovessels of xenograft Lewis lung carcinoma tumors in wild-type- or bone-marrow-transplanted mice. Accordingly, decursin attenuated EPC-derived endothelial cells in neovessels of Lewis lung carcinoma tumor masses grown in mice. Together, decursin likely affects EPC differentiation and function, thereby inhibiting tumor vasculogenesis in early tumorigenesis. Copyright © 2012 Wiley Periodicals, Inc.

  12. FGF-2 signal promotes proliferation of cerebellar progenitor cells and their oligodendrocytic differentiation at early postnatal stage

    SciTech Connect

    Naruse, Masae; Shibasaki, Koji; Ishizaki, Yasuki, E-mail: yasukiishizaki@gunma-u.ac.jp

    The origins and developmental regulation of cerebellar oligodendrocytes are largely unknown, although some hypotheses of embryonic origins have been suggested. Neural stem cells exist in the white matter of postnatal cerebellum, but it is unclear whether these neural stem cells generate oligodendrocytes at postnatal stages. We previously showed that cerebellar progenitor cells, including neural stem cells, widely express CD44 at around postnatal day 3. In the present study, we showed that CD44-positive cells prepared from the postnatal day 3 cerebellum gave rise to neurospheres, while CD44-negative cells prepared from the same cerebellum did not. These neurospheres differentiated mainly into oligodendrocytesmore » and astrocytes, suggesting that CD44-positive neural stem/progenitor cells might generate oligodendrocytes in postnatal cerebellum. We cultured CD44-positive cells from the postnatal day 3 cerebellum in the presence of signaling molecules known as mitogens or inductive differentiation factors for oligodendrocyte progenitor cells. Of these, only FGF-2 promoted survival and proliferation of CD44-positive cells, and these cells differentiated into O4+ oligodendrocytes. Furthermore, we examined the effect of FGF-2 on cerebellar oligodendrocyte development ex vivo. FGF-2 enhanced proliferation of oligodendrocyte progenitor cells and increased the number of O4+ and CC1+ oligodendrocytes in slice cultures. These results suggest that CD44-positive cells might be a source of cerebellar oligodendrocytes and that FGF-2 plays important roles in their development at an early postnatal stage. - Highlights: • CD44 is expressed in cerebellar neural stem/progenitor cells at postnatal day 3 (P3). • FGF-2 promoted proliferation of CD44-positive progenitor cells from P3 cerebellum. • FGF-2 promoted oligodendrocytic differentiation of CD44-positive progenitor cells. • FGF-2 increased the number of oligodendrocytes in P3 cerebellar slice culture.« less

  13. Early molecular events during retinoic acid induced differentiation of neuromesodermal progenitors

    PubMed Central

    Cunningham, Thomas J.; Colas, Alexandre

    2016-01-01

    ABSTRACT Bipotent neuromesodermal progenitors (NMPs) residing in the caudal epiblast drive coordinated body axis extension by generating both posterior neuroectoderm and presomitic mesoderm. Retinoic acid (RA) is required for body axis extension, however the early molecular response to RA signaling is poorly defined, as is its relationship to NMP biology. As endogenous RA is first seen near the time when NMPs appear, we used WNT/FGF agonists to differentiate embryonic stem cells to NMPs which were then treated with a short 2-h pulse of 25 nM RA or 1 µM RA followed by RNA-seq transcriptome analysis. Differential expression analysis of this dataset indicated that treatment with 25 nM RA, but not 1 µM RA, provided physiologically relevant findings. The 25 nM RA dataset yielded a cohort of previously known caudal RA target genes including Fgf8 (repressed) and Sox2 (activated), plus novel early RA signaling targets with nearby conserved RA response elements. Importantly, validation of top-ranked genes in vivo using RA-deficient Raldh2−/− embryos identified novel examples of RA activation (Nkx1-2, Zfp503, Zfp703, Gbx2, Fgf15, Nt5e) or RA repression (Id1) of genes expressed in the NMP niche or progeny. These findings provide evidence for early instructive and permissive roles of RA in controlling differentiation of NMPs to neural and mesodermal lineages. PMID:27793834

  14. FGF/EGF signaling regulates the renewal of early nephron progenitors during embryonic development.

    PubMed

    Brown, Aaron C; Adams, Derek; de Caestecker, Mark; Yang, Xuehui; Friesel, Robert; Oxburgh, Leif

    2011-12-01

    Recent studies indicate that nephron progenitor cells of the embryonic kidney are arranged in a series of compartments of an increasing state of differentiation. The earliest progenitor compartment, distinguished by expression of CITED1, possesses greater capacity for renewal and differentiation than later compartments. Signaling events governing progression of nephron progenitor cells through stages of increasing differentiation are poorly understood, and their elucidation will provide key insights into normal and dysregulated nephrogenesis, as well as into regenerative processes that follow kidney injury. In this study, we found that the mouse CITED1(+) progenitor compartment is maintained in response to receptor tyrosine kinase (RTK) ligands that activate both FGF and EGF receptors. This RTK signaling function is dependent on RAS and PI3K signaling but not ERK. In vivo, RAS inactivation by expression of sprouty 1 (Spry1) in CITED1(+) nephron progenitors results in loss of characteristic molecular marker expression and in increased death of progenitor cells. Lineage tracing shows that surviving Spry1-expressing progenitor cells are impaired in their subsequent epithelial differentiation, infrequently contributing to epithelial structures. These findings demonstrate that the survival and developmental potential of cells in the earliest embryonic nephron progenitor cell compartment are dependent on FGF/EGF signaling through RAS.

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

    PubMed

    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.

  16. Genome evolution of intermediate wheatgrass as revealed by EST-SSR markers developed from its three progenitor diploid species

    USDA-ARS?s Scientific Manuscript database

    Intermediate wheatgrass [Thinopyrum intermedium (Host) Barkworth & D.R. Dewey], a segmental autoallohexaploid (2n=6x=42), is not only an important forage crop but also a valuable gene reservoir for wheat (Triticum aestivum L.) improvement. Throughout the scientific literature, there continues to be...

  17. Identification of early fumonisin biosynthetic intermediates by inactivation of the FUM6 gene in Fusarium verticillioides

    USDA-ARS?s Scientific Manuscript database

    Fumonisins are polyketide mycotoxins produced by the maize pathogen Fusarium verticillioides and are associated with multiple human and animal diseases. A fumonisin biosynthetic pathway has been proposed, but structures of early pathway intermediates have not been demonstrated. The F. verticillioide...

  18. Early dust formation and a massive progenitor for SN 2011ja?

    NASA Astrophysics Data System (ADS)

    Andrews, J. E.; Krafton, Kelsie M.; Clayton, Geoffrey C.; Montiel, E.; Wesson, R.; Sugerman, Ben E. K.; Barlow, M. J.; Matsuura, M.; Drass, H.

    2016-04-01

    SN 2011ja was a bright (I = -18.3) Type II supernova occurring in the nearby edge on spiral galaxy NGC 4945. Flat-topped and multipeaked H α and H β spectral emission lines appear between 64 and 84 d post-explosion, indicating interaction with a disc-like circumstellar medium inclined ˜45° from edge-on. After day 84, an increase in the H- and K-band flux along with heavy attenuation of the red wing of the emission lines are strong indications of early dust formation, likely located in the cool dense shell created between the forward shock of the SN ejecta and the reverse shock created as the ejecta plows into the existing circumstellar material. Radiative transfer modelling reveals both ≈1 × 10-5 M⊙ of pre-existing dust located ˜1016.7 cm away and up to ≈6 × 10-4 M⊙ of newly formed dust. Spectral observations after 1.5 yr reveal the possibility that the fading SN is located within a young (3-6 Myr) massive stellar cluster, which when combined with tentative 56Ni mass estimates of 0.2 M⊙ may indicate a massive (≥25 M⊙) progenitor for SN 2011ja.

  19. Functional interleukin-33 receptors are expressed in early progenitor stages of allergy-related granulocytes.

    PubMed

    Tsuzuki, Hirofumi; Arinobu, Yojiro; Miyawaki, Kohta; Takaki, Ayako; Ota, Shun-Ichiro; Ota, Yuri; Mitoma, Hiroki; Akahoshi, Mitsuteru; Mori, Yasuo; Iwasaki, Hiromi; Niiro, Hiroaki; Tsukamoto, Hiroshi; Akashi, Koichi

    2017-01-01

    Interleukin-33 (IL-33) induces T helper type 2 (Th2) cytokine production and eosinophilia independently of acquired immunity, leading to innate immunity-mediated allergic inflammation. Allergy-related innate myeloid cells such as eosinophils, basophils and mast cells express the IL-33 receptor (IL-33R), but it is still unknown how IL-33 regulates allergic inflammation involving these cells and their progenitors. Here, we revealed that the functional IL-33R was expressed on eosinophil progenitors (EoPs), basophil progenitors (BaPs) and mast cell progenitors (MCPs). In the presence of IL-33, these progenitors did not expand, but produced a high amount of Th2 and pro-inflammatory cytokines such as IL-9, IL-13, IL-1β and IL-6. The amount of cytokines produced by these progenitors was greater than that by mature cells. In vivo, IL-33 stimulated the expansion of EoPs, but it was dependent upon the elevated serum IL-5 that is presumably derived from type 2 innate lymphoid cells that express functional IL-33R. These data collectively suggest that EoPs, BaPs and MCPs are not only the sources of allergy-related granulocytes, but can also be sources of allergy-related cytokines in IL-33-induced inflammation. Because such progenitors can differentiate into mature granulocytes at the site of inflammation, they are potential therapeutic targets in IL-33-related allergic diseases. © 2016 John Wiley & Sons Ltd.

  20. Reduced survival in patients with early-stage non-small-cell lung cancer is associated with high pleural endothelial progenitor cell levels.

    PubMed

    Pirro, Matteo; Cagini, Lucio; Mannarino, Massimo R; Andolfi, Marco; Potenza, Rossella; Paciullo, Francesco; Bianconi, Vanessa; Frangione, Maria Rosaria; Bagaglia, Francesco; Puma, Francesco; Mannarino, Elmo

    2016-12-01

    Endothelial progenitor cells are capable of contributing to neovascularization in tumours. In patients with either malignant or transudative pleural effusion, we tested the presence of pleural endothelial progenitor cells. We also measured the number of endothelial progenitor cells in post-surgery pleural drainage of either patients with early non-small-cell lung cancer or control patients with benign lung disease undergoing pulmonary resection. The prospective influence of post-surgery pleural-drainage endothelial progenitor cells on cancer recurrence/survival was investigated. Pleural endothelial progenitor cell levels were quantified by fluorescence-activated cell sorting analysis in pleural effusion of 15 patients with late-stage non-small-cell lung cancer with pleural involvement and in 15 control patients with congestive heart failure. Also, pleural-drainage endothelial progenitor cells were measured in pleural-drainage fluid 48 h after surgery in 64 patients with early-stage non-small-cell lung cancer and 20 benign lung disease patients undergoing pulmonary resection. Cancer recurrence and survival was evaluated in patients with high pleural-drainage endothelial progenitor cell levels. The number of pleural endothelial progenitor cells was higher in non-small-cell lung cancer pleural effusion than in transudative pleural effusion. Also, pleural-drainage endothelial progenitor cell levels were higher in patients with non-small-cell lung cancer than in patients with benign lung disease undergoing pulmonary resection (P < 0.05). Non-small-cell lung cancer patients with high pleural-drainage endothelial progenitor cell levels had a significantly 4.9 higher rate of cancer recurrence/death than patients with lower pleural-drainage endothelial progenitor cell levels, irrespective of confounders. Endothelial progenitor cells are present in the pleural effusion and are higher in patients with late-stage non-small-cell lung cancer with pleural involvement than in

  1. Fos Promotes Early Stage Teno-Lineage Differentiation of Tendon Stem/Progenitor Cells in Tendon.

    PubMed

    Chen, Jialin; Zhang, Erchen; Zhang, Wei; Liu, Zeyu; Lu, Ping; Zhu, Ting; Yin, Zi; Backman, Ludvig J; Liu, Huanhuan; Chen, Xiao; Ouyang, Hongwei

    2017-11-01

    Stem cells have been widely used in tendon tissue engineering. The lack of refined and controlled differentiation strategy hampers the tendon repair and regeneration. This study aimed to find new effective differentiation factors for stepwise tenogenic differentiation. By microarray screening, the transcript factor Fos was found to be expressed in significantly higher amounts in postnatal Achilles tendon tissue derived from 1 day as compared with 7-days-old rats. It was further confirmed that expression of Fos decreased with time in postnatal rat Achilles tendon, which was accompanied with the decreased expression of multiply tendon markers. The expression of Fos also declined during regular in vitro cell culture, which corresponded to the loss of tendon phenotype. In a cell-sheet and a three-dimensional cell culture model, the expression of Fos was upregulated as compared with in regular cell culture, together with the recovery of tendon phenotype. In addition, significant higher expression of tendon markers was found in Fos-overexpressed tendon stem/progenitor cells (TSPCs), and Fos knock-down gave opposite results. In situ rat tendon repair experiments found more normal tendon-like tissue formed and higher tendon markers expression at 4 weeks postimplantation of Fos-overexpressed TSPCs derived nonscaffold engineering tendon (cell-sheet), as compared with the control group. This study identifies Fos as a new marker and functional driver in the early stage teno-lineage differentiation of tendon, which paves the way for effective stepwise tendon differentiation and future tendon regeneration. Stem Cells Translational Medicine 2017;6:2009-2019. © 2017 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

  2. THE INTERMEDIATE LUMINOSITY OPTICAL TRANSIENT SN 2010DA: THE PROGENITOR, ERUPTION, AND AFTERMATH OF A PECULIAR SUPERGIANT HIGH-MASS X-RAY BINARY

    SciTech Connect

    Villar, V. A.; Berger, E.; Blanchard, P. K.

    We present optical spectroscopy, ultraviolet-to-infrared imaging, and X-ray observations of the intermediate luminosity optical transient (ILOT) SN 2010da in NGC 300 ( d = 1.86 Mpc) spanning from −6 to +6 years relative to the time of outburst in 2010. Based on the light-curve and multi-epoch spectral energy distributions of SN 2010da, we conclude that the progenitor of SN 2010da is a ≈10–12 M {sub ⊙} yellow supergiant possibly transitioning into a blue-loop phase. During outburst, SN 2010da had a peak absolute magnitude of M {sub bol} ≲ −10.4 mag, dimmer than other ILOTs and supernova impostors. We detect multi-componentmore » hydrogen Balmer, Paschen, and Ca ii emission lines in our high-resolution spectra, which indicate a dusty and complex circumstellar environment. Since the 2010 eruption, the star has brightened by a factor of ≈5 and remains highly variable in the optical. Furthermore, we detect SN 2010da in archival Swift and Chandra observations as an ultraluminous X-ray source ( L {sub X} ≈ 6 × 10{sup 39} erg s{sup −1}). We additionally attribute He ii 4686 Å and coronal Fe emission lines in addition to a steady X-ray luminosity of ≈10{sup 37} erg s{sup −1} to the presence of a compact companion.« less

  3. The Intermediate Luminosity Optical Transient SN 2010da: The Progenitor, Eruption, and Aftermath of a Peculiar Supergiant High-mass X-Ray Binary

    NASA Astrophysics Data System (ADS)

    Villar, V. A.; Berger, E.; Chornock, R.; Margutti, R.; Laskar, T.; Brown, P. J.; Blanchard, P. K.; Czekala, I.; Lunnan, R.; Reynolds, M. T.

    2016-10-01

    We present optical spectroscopy, ultraviolet-to-infrared imaging, and X-ray observations of the intermediate luminosity optical transient (ILOT) SN 2010da in NGC 300 (d = 1.86 Mpc) spanning from -6 to +6 years relative to the time of outburst in 2010. Based on the light-curve and multi-epoch spectral energy distributions of SN 2010da, we conclude that the progenitor of SN 2010da is a ≈10-12 M ⊙ yellow supergiant possibly transitioning into a blue-loop phase. During outburst, SN 2010da had a peak absolute magnitude of M bol ≲ -10.4 mag, dimmer than other ILOTs and supernova impostors. We detect multi-component hydrogen Balmer, Paschen, and Ca II emission lines in our high-resolution spectra, which indicate a dusty and complex circumstellar environment. Since the 2010 eruption, the star has brightened by a factor of ≈5 and remains highly variable in the optical. Furthermore, we detect SN 2010da in archival Swift and Chandra observations as an ultraluminous X-ray source (L X ≈ 6 × 1039 erg s-1). We additionally attribute He II 4686 Å and coronal Fe emission lines in addition to a steady X-ray luminosity of ≈1037 erg s-1 to the presence of a compact companion.

  4. A Walk through TRIDEC's intermediate Tsunami Early Warning System

    NASA Astrophysics Data System (ADS)

    Hammitzsch, M.; Reißland, S.; Lendholt, M.

    2012-04-01

    The management of natural crises is an important application field of the technology developed in the project Collaborative, Complex, and Critical Decision-Support in Evolving Crises (TRIDEC), co-funded by the European Commission in its Seventh Framework Programme. TRIDEC is based on the development of the German Indonesian Tsunami Early Warning System (GITEWS) and the Distant Early Warning System (DEWS) providing a service platform for both sensor integration and warning dissemination. In TRIDEC new developments in Information and Communication Technology (ICT) are used to extend the existing platform realising a component-based technology framework for building distributed tsunami warning systems for deployment, e.g. in the North-eastern Atlantic, the Mediterranean and Connected Seas (NEAM) region. The TRIDEC system will be implemented in three phases, each with a demonstrator. Successively, the demonstrators are addressing challenges, such as the design and implementation of a robust and scalable service infrastructure supporting the integration and utilisation of existing resources with accelerated generation of large volumes of data. These include sensor systems, geo-information repositories, simulation tools and data fusion tools. In addition to conventional sensors also unconventional sensors and sensor networks play an important role in TRIDEC. The system version presented is based on service-oriented architecture (SOA) concepts and on relevant standards of the Open Geospatial Consortium (OGC), the World Wide Web Consortium (W3C) and the Organization for the Advancement of Structured Information Standards (OASIS). In this way the system continuously gathers, processes and displays events and data coming from open sensor platforms to enable operators to quickly decide whether an early warning is necessary and to send personalized warning messages to the authorities and the population at large through a wide range of communication channels. The system

  5. Exercise training improves in vivo endothelial repair capacity of early endothelial progenitor cells in subjects with metabolic syndrome.

    PubMed

    Sonnenschein, Kristina; Horváth, Tibor; Mueller, Maja; Markowski, Andrea; Siegmund, Tina; Jacob, Christian; Drexler, Helmut; Landmesser, Ulf

    2011-06-01

    Endothelial dysfunction and injury are considered to contribute considerably to the development and progression of atherosclerosis. It has been suggested that intense exercise training can increase the number and angiogenic properties of early endothelial progenitor cells (EPCs). However, whether exercise training stimulates the capacity of early EPCs to promote repair of endothelial damage and potential underlying mechanisms remain to be determined. The present study was designed to evaluate the effects of moderate exercise training on in vivo endothelial repair capacity of early EPCs, and their nitric oxide and superoxide production as characterized by electron spin resonance spectroscopy analysis in subjects with metabolic syndrome. Twenty-four subjects with metabolic syndrome were randomized to an 8 weeks exercise training or a control group. Superoxide production and nitric oxide (NO) availability of early EPCs were characterized by using electron spin resonance (ESR) spectroscopy analysis. In vivo endothelial repair capacity of EPCs was examined by transplantation into nude mice with defined carotid endothelial injury. Endothelium-dependent, flow-mediated vasodilation was analysed using high-resolution ultrasound. Importantly, exercise training resulted in a substantially improved in vivo endothelial repair capacity of early EPCs (24.0 vs 12.7%; p < 0.05) and improved endothelium-dependent vasodilation. Nitric oxide production of EPCs was substantially increased after exercise training, but not in the control group. Moreover, exercise training reduced superoxide production of EPCs, which was not observed in the control group. The present study suggests for the first time that moderate exercise training increases nitric oxide production of early endothelial progenitor cells and reduces their superoxide production. Importantly, this is associated with a marked beneficial effect on the in vivo endothelial repair capacity of early EPCs in subjects with

  6. CD34(+) Liver Cancer Stem Cells Were Formed by Fusion of Hepatobiliary Stem/Progenitor Cells with Hematopoietic Precursor-Derived Myeloid Intermediates.

    PubMed

    Zeng, Changjun; Zhang, Yanling; Park, Su Cheol; Eun, Jong Ryeol; Nguyen, Ngoc Tue; Tschudy-Seney, Benjamin; Jung, Yong Jin; Theise, Neil D; Zern, Mark A; Duan, Yuyou

    2015-11-01

    A large number of cancer stem cells (CSCs) were identified and characterized; however, the origins and formation of CSCs remain elusive. In this study, we examined the origination of the newly identified CD34(+) liver CSC (LCSC). We found that CD34(+) LCSC coexpressed liver stem cell and myelomonocytic cell markers, showing a mixed phenotype, a combination of hepatobiliary stem/progenitor cells (HSPCs) and myelomonocytic cells. Moreover, human xenografts produced by CD34(+) LCSCs and the parental cells, which CD34(+) LCSC was isolated from, coexpressed liver cancer and myelomonocytic markers, also demonstrating mixed phenotypes. The xenografts and the parental cells secreted albumin demonstrating their hepatocyte origin and also expressed cytokines [interleukin (IL)-1b, IL-6, IL-12A, IL-18, tumor necrosis factor-alpha (TNF-α), and CSF1] and chemokines (IL-8, CCL2, and CCL5). Expression of these cytokines and chemokines responded to the stimuli [interferon-γ (INF-γ), IL-4, and lipopolysaccharide (LPS)]. Furthermore, human xenografts and the parental cells phagocytized Escherichia coli. CD34(+) LCSC coexpressed CD45, demonstrating that its origin appears to be from a hematopoietic precursor. The percentage of cells positive for OV6, CD34, and CD31, presenting the markers of HSPC, hematopoietic, and myelomonocytic cells, increased under treatment of CD34(+) LCSC with a drug. Cytogenetic analysis showed that CD34(+) LCSC contained a greater number of chromosomes. HBV DNA integrations and mutations in CD34(+) LCSC and the parental cells were identical to those in the literature or the database. Thus, these results demonstrated that CD34(+) LCSCs were formed by fusion of HSPC with CD34(+) hematopoietic precursor-derived myeloid intermediates; it appears that this is the first report that human CSCs have been formed by the fusion. Therefore, it represents a significant step toward better understanding of the formation of human CSC and the diverse origins of liver

  7. Progenitors of Secondary Crest Myofibroblasts are Developmentally Committed in Early Lung Mesoderm

    PubMed Central

    Li, Changgong; Li, Min; Li, Sha; Xing, Yiming; Yang, Chang-Yo; Li, Aimin; Borok, Zea; De Langhe, Stijn; Minoo, Parviz

    2015-01-01

    Development of the mammalian lung is predicated on cross-communications between two highly interactive tissues, the endodermally-derived epithelium and the mesodermally-derived pulmonary mesenchyme. While much attention has been paid the lung epithelium, the pulmonary mesenchyme, partly due to lack of specific tractable markers remains under-investigated. The lung mesenchyme is derived from the lateral plate mesoderm and is the principal recipient of Hedgehog (Hh) signaling, a morphogenetic network that regulates multiple aspects of embryonic development. Using the Hh-responsive Gli1-creERT2 mouse line, we identified the mesodermal targets of Hh signaling at various time points during embryonic and postnatal lung development. Cell lineage analysis showed these cells serve as progenitors to contribute to multiple lineages of mesodermally-derived differentiated cell types that include parenchymal or interstitial myofibroblasts, parabronchial and perivascular smooth muscle as well as rare populations of cells within the mesothelium. Most importantly, Gli1-creERT2 identified the progenitors of secondary crest myofibroblasts, a hitherto intractable cell type that plays a key role in alveolar formation, a vital process about which little is currently known. Transcriptome analysis of Hh-targeted progenitor cells transitioning from the pseudoglandular to the saccular phase of lung development revealed important modulations of key signaling pathways. Amongst these, there was significant down-regulation of canonical WNT signaling. Ectopic stabilization of β-Catenin via inactivation of Apc by Gli1-creERT2 expanded the Hh-targeted progenitor pools, which caused the formation of fibroblastic masses within the lung parenchyma. The Gli1-creERT2 mouse line represents a novel tool in the analysis of mesenchymal cell biology and alveolar formation during lung development. PMID:25448080

  8. Single-cell RNA sequencing reveals developmental heterogeneity among early lymphoid progenitors.

    PubMed

    Alberti-Servera, Llucia; von Muenchow, Lilly; Tsapogas, Panagiotis; Capoferri, Giuseppina; Eschbach, Katja; Beisel, Christian; Ceredig, Rhodri; Ivanek, Robert; Rolink, Antonius

    2017-12-15

    Single-cell RNA sequencing is a powerful technology for assessing heterogeneity within defined cell populations. Here, we describe the heterogeneity of a B220 + CD117 int CD19 - NK1.1 - uncommitted hematopoietic progenitor having combined lymphoid and myeloid potential. Phenotypic and functional assays revealed four subpopulations within the progenitor with distinct lineage developmental potentials. Among them, the Ly6D + SiglecH - CD11c - fraction was lymphoid-restricted exhibiting strong B-cell potential, whereas the Ly6D - SiglecH - CD11c - fraction showed mixed lympho-myeloid potential. Single-cell RNA sequencing of these subsets revealed that the latter population comprised a mixture of cells with distinct lymphoid and myeloid transcriptional signatures and identified a subgroup as the potential precursor of Ly6D + SiglecH - CD11c - Subsequent functional assays confirmed that B220 + CD117 int CD19 - NK1.1 - single cells are, with rare exceptions, not bipotent for lymphoid and myeloid lineages. A B-cell priming gradient was observed within the Ly6D + SiglecH - CD11c - subset and we propose a herein newly identified subgroup as the direct precursor of the first B-cell committed stage. Therefore, the apparent multipotency of B220 + CD117 int CD19 - NK1.1 - progenitors results from underlying heterogeneity at the single-cell level and highlights the validity of single-cell transcriptomics for resolving cellular heterogeneity and developmental relationships among hematopoietic progenitors. © 2017 The Authors.

  9. The scaffold protein Nde1 safeguards the brain genome during S phase of early neural progenitor differentiation

    PubMed Central

    Houlihan, Shauna L; Feng, Yuanyi

    2014-01-01

    Successfully completing the S phase of each cell cycle ensures genome integrity. Impediment of DNA replication can lead to DNA damage and genomic disorders. In this study, we show a novel function for NDE1, whose mutations cause brain developmental disorders, in safeguarding the genome through S phase during early steps of neural progenitor fate restrictive differentiation. Nde1 mutant neural progenitors showed catastrophic DNA double strand breaks concurrent with the DNA replication. This evoked DNA damage responses, led to the activation of p53-dependent apoptosis, and resulted in the reduction of neurons in cortical layer II/III. We discovered a nuclear pool of Nde1, identified the interaction of Nde1 with cohesin and its associated chromatin remodeler, and showed that stalled DNA replication in Nde1 mutants specifically occurred in mid-late S phase at heterochromatin domains. These findings suggest that NDE1-mediated heterochromatin replication is indispensible for neuronal differentiation, and that the loss of NDE1 function may lead to genomic neurological disorders. DOI: http://dx.doi.org/10.7554/eLife.03297.001 PMID:25245017

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

    PubMed

    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.

  11. Early loss of Crebbp confers malignant stem cell properties on lymphoid progenitors.

    PubMed

    Horton, Sarah J; Giotopoulos, George; Yun, Haiyang; Vohra, Shabana; Sheppard, Olivia; Bashford-Rogers, Rachael; Rashid, Mamunur; Clipson, Alexandra; Chan, Wai-In; Sasca, Daniel; Yiangou, Loukia; Osaki, Hikari; Basheer, Faisal; Gallipoli, Paolo; Burrows, Natalie; Erdem, Ayşegül; Sybirna, Anastasiya; Foerster, Sarah; Zhao, Wanfeng; Sustic, Tonci; Petrunkina Harrison, Anna; Laurenti, Elisa; Okosun, Jessica; Hodson, Daniel; Wright, Penny; Smith, Ken G; Maxwell, Patrick; Fitzgibbon, Jude; Du, Ming Q; Adams, David J; Huntly, Brian J P

    2017-09-01

    Loss-of-function mutations of cyclic-AMP response element binding protein, binding protein (CREBBP) are prevalent in lymphoid malignancies. However, the tumour suppressor functions of CREBBP remain unclear. We demonstrate that loss of Crebbp in murine haematopoietic stem and progenitor cells (HSPCs) leads to increased development of B-cell lymphomas. This is preceded by accumulation of hyperproliferative lymphoid progenitors with a defective DNA damage response (DDR) due to a failure to acetylate p53. We identify a premalignant lymphoma stem cell population with decreased H3K27ac, which undergoes transcriptional and genetic evolution due to the altered DDR, resulting in lymphomagenesis. Importantly, when Crebbp is lost later in lymphopoiesis, cellular abnormalities are lost and tumour generation is attenuated. We also document that CREBBP mutations may occur in HSPCs from patients with CREBBP-mutated lymphoma. These data suggest that earlier loss of Crebbp is advantageous for lymphoid transformation and inform the cellular origins and subsequent evolution of lymphoid malignancies.

  12. Cuprizone decreases intermediate and late-stage progenitor cells in hippocampal neurogenesis of rats in a framework of 28-day oral dose toxicity study

    SciTech Connect

    Abe, Hajime; Tanaka, Takeshi; Kimura, Masayuki

    2015-09-15

    Developmental exposure to cuprizone (CPZ), a demyelinating agent, impairs intermediate-stage neurogenesis in the hippocampal dentate gyrus of rat offspring. To investigate the possibility of alterations in adult neurogenesis following postpubertal exposure to CPZ in a framework of general toxicity studies, CPZ was orally administered to 5-week-old male rats at 0, 120, or 600 mg/kg body weight/day for 28 days. In the subgranular zone (SGZ), 600 mg/kg CPZ increased the number of cleaved caspase-3{sup +} apoptotic cells. At ≥ 120 mg/kg, the number of SGZ cells immunoreactive for TBR2, doublecortin, or PCNA was decreased, while that for SOX2 was increased. Inmore » the granule cell layer, CPZ at ≥ 120 mg/kg decreased the number of postmitotic granule cells immunoreactive for NEUN, CHRNA7, ARC or FOS. In the dentate hilus, CPZ at ≥ 120 mg/kg decreased phosphorylated TRKB{sup +} interneurons, although the number of reelin{sup +} interneurons was unchanged. At 600 mg/kg, mRNA levels of Bdnf and Chrna7 were decreased, while those of Casp4, Casp12 and Trib3 were increased in the dentate gyrus. These data suggest that CPZ in a scheme of 28-day toxicity study causes endoplasmic reticulum stress-mediated apoptosis of granule cell lineages, resulting in aberrations of intermediate neurogenesis and late-stage neurogenesis and following suppression of immediate early gene-mediated neuronal plasticity. Suppression of BDNF signals to interneurons caused by decreased cholinergic signaling may play a role in these effects of CPZ. The effects of postpubertal CPZ on neurogenesis were similar to those observed with developmental exposure, except for the lack of reelin response, which may contribute to a greater decrease in SGZ cells. - Highlights: • Effect of 28-day CPZ exposure on hippocampal neurogenesis was examined in rats. • CPZ suppressed intermediate neurogenesis and late-stage neurogenesis in the dentate gyrus. • CPZ suppressed BDNF signals to interneurons by

  13. Sall4-Gli3 system in early limb progenitors is essential for the development of limb skeletal elements.

    PubMed

    Akiyama, Ryutaro; Kawakami, Hiroko; Wong, Julia; Oishi, Isao; Nishinakamura, Ryuichi; Kawakami, Yasuhiko

    2015-04-21

    Limb skeletal elements originate from the limb progenitor cells, which undergo expansion and patterning to develop each skeletal element. Posterior-distal skeletal elements, such as the ulna/fibula and posterior digits develop in a Sonic hedgehog (Shh)-dependent manner. However, it is poorly understood how anterior-proximal elements, such as the humerus/femur, the radius/tibia and the anterior digits, are developed. Here we show that the zinc finger factors Sall4 and Gli3 cooperate for proper development of the anterior-proximal skeletal elements and also function upstream of Shh-dependent posterior skeletal element development. Conditional inactivation of Sall4 in the mesoderm before limb outgrowth caused severe defects in the anterior-proximal skeletal elements in the hindlimb. We found that Gli3 expression is reduced in Sall4 mutant hindlimbs, but not in forelimbs. This reduction caused posteriorization of nascent hindlimb buds, which is correlated with a loss of anterior digits. In proximal development, Sall4 integrates Gli3 and the Plzf-Hox system, in addition to proliferative expansion of cells in the mesenchymal core of nascent hindlimb buds. Whereas forelimbs developed normally in Sall4 mutants, further genetic analysis identified that the Sall4-Gli3 system is a common regulator of the early limb progenitor cells in both forelimbs and hindlimbs. The Sall4-Gli3 system also functions upstream of the Shh-expressing ZPA and the Fgf8-expressing AER in fore- and hindlimbs. Therefore, our study identified a critical role of the Sall4-Gli3 system at the early steps of limb development for proper development of the appendicular skeletal elements.

  14. Classification of Rhinoentomophthoromycosis into Atypical, Early, Intermediate, and Late Disease: A Proposal

    PubMed Central

    Blumentrath, Christian G.; Grobusch, Martin P.; Matsiégui, Pierre-Blaise; Pahlke, Friedrich; Zoleko-Manego, Rella; Nzenze-Aféne, Solange; Mabicka, Barthélemy; Sanguinetti, Maurizio; Kremsner, Peter G.; Schaumburg, Frieder

    2015-01-01

    Background Rhinoentomophthoromycosis, or rhino-facial conidiobolomycosis, is a rare, grossly disfiguring disease due to an infection with entomophthoralean fungi. We report a case of rhinoentomophthoromycosis from Gabon and suggest a staging system, which provides information on the prognosis and duration of antifungal therapy. Methods We present a case of rhinoentomophthoromycosis including the histopathology, mycology, and course of disease. For the suggested staging system, all cases on confirmed rhinoentomophthoromycosis published in the literature without language restriction were eligible. Exclusion criteria were missing data on (i) duration of disease before correct diagnosis, (ii) outcome, and (iii) confirmation of entomophthoralean fungus infection by histopathology and/or mycology. We classified cases into atypical (orbital cellulitis, severe pain, fever, dissemination), early, intermediate, and late disease based on the duration of symptoms before diagnosis. The outcome was evaluated for each stage of disease. Findings The literature search of the Medpilot database was conducted on January 13, 2014, (updated on January 18, 2015). The search yielded 8,333 results including 198 cases from 117 papers; of these, 145 met our inclusion criteria and were included in the final analysis. Median duration of treatment was 4, 3, 4, and 5 months in atypical, early, intermediate, and late disease, respectively. Cure rates were clearly associated with stage of disease and were 57%, 100%, 82%, and 43% in atypical, early, intermediate, and late disease, respectively. Conclusion We suggest a clinical staging system that underlines the benefit of early case detection and may guide the duration of antifungal treatment. The scientific value of this classification is its capacity to structure and harmonize the clinical and research approach towards rhinoentomophthoromycosis. PMID:26426120

  15. Isolation and characterization of progenitor cells from surgically created - early healing alveolar defects in humans. A preliminary study.

    PubMed

    Sant'Ana, Adriana Campos Passanezi; Damante, Carla Andreotti; Martinez, Maria Alejandra Frias; Valdivia, Maria Alejandra Medina; Karam, Paula Stefânia Hage; de Oliveira, Flavia Amadeu; de Oliveira, Rodrigo Cardoso; Gasparoto, Thais Helena; Campanelli, Ana Paula; Zangrando, Mariana Schutzer Ragghianti; de Rezende, Maria Lúcia Rubo; Greghi, Sebastião Luiz Aguiar; Passanezi, Euloir

    2018-05-30

    The granulation tissue (GT) present in surgically-created early healing sockets has been considered as a possible source of osteoprogenitor cells for periodontal regeneration, as demonstrated in animal studies. However, the in vitro osteogenic properties of tissue removed from human surgically-created early healing alveolar defects (SC-EHAD) remains to be established, being that the aim of this study. Surgical defects were created in the edentulous ridge of two systemically healthy adults. The healing tissue present in these defects was removed 21 days later for the establishment of primary culture. The in vitro characteristics of the cultured cells were determined by Armelin method, MTT assay, immunohistochemistry, alkaline phosphatase (ALP) activity, mineralization assay and flow cytometry for detection of stem cells/osteoprogenitor cell markers. Cells were able to adhere to the plastic and assumed spindle-shaped morphology at earlier passages, changing to a cuboidal one with increasing passages. Differences in the proliferation rate were observed with increasing passages, suggesting osteogenic differentiation. ALP and mineralization activities were detected in conventional and osteogenic medium. Fresh samples of SC-EHAD tissue exhibited CD34 - and CD45 - phenotypes. Cells at later passages (14 th ) exhibited CD34 - , CD45 - , CD105 - , CD166 - and collagen type I + phenotype. Tissue removed from SC-EHAD is a possible source of progenitor cells. This article is protected by copyright. All rights reserved. © 2018 American Academy of Periodontology.

  16. Intermediate-term forecasting of aftershocks from an early aftershock sequence: Bayesian and ensemble forecasting approaches

    NASA Astrophysics Data System (ADS)

    Omi, Takahiro; Ogata, Yosihiko; Hirata, Yoshito; Aihara, Kazuyuki

    2015-04-01

    Because aftershock occurrences can cause significant seismic risks for a considerable time after the main shock, prospective forecasting of the intermediate-term aftershock activity as soon as possible is important. The epidemic-type aftershock sequence (ETAS) model with the maximum likelihood estimate effectively reproduces general aftershock activity including secondary or higher-order aftershocks and can be employed for the forecasting. However, because we cannot always expect the accurate parameter estimation from incomplete early aftershock data where many events are missing, such forecasting using only a single estimated parameter set (plug-in forecasting) can frequently perform poorly. Therefore, we here propose Bayesian forecasting that combines the forecasts by the ETAS model with various probable parameter sets given the data. By conducting forecasting tests of 1 month period aftershocks based on the first 1 day data after the main shock as an example of the early intermediate-term forecasting, we show that the Bayesian forecasting performs better than the plug-in forecasting on average in terms of the log-likelihood score. Furthermore, to improve forecasting of large aftershocks, we apply a nonparametric (NP) model using magnitude data during the learning period and compare its forecasting performance with that of the Gutenberg-Richter (G-R) formula. We show that the NP forecast performs better than the G-R formula in some cases but worse in other cases. Therefore, robust forecasting can be obtained by employing an ensemble forecast that combines the two complementary forecasts. Our proposed method is useful for a stable unbiased intermediate-term assessment of aftershock probabilities.

  17. Early and intermediate age-related macular degeneration: update and clinical review.

    PubMed

    García-Layana, Alfredo; Cabrera-López, Francisco; García-Arumí, José; Arias-Barquet, Lluís; Ruiz-Moreno, José M

    2017-01-01

    Age-related macular degeneration (AMD) is the leading cause of irreversible central vision loss in developed countries. With the aging of population, AMD will become globally an increasingly important and prevalent disease worldwide. It is a complex disease whose etiology is associated with both genetic and environmental risk factors. An extensive decline in the quality of life and progressive need of daily living assistance resulting from AMD among those most severely affected highlights the essential role of preventive strategies, particularly advising patients to quit smoking. In addition, maintaining a healthy diet, controlling other risk factors (such as hypertension, obesity, and atherosclerosis), and the use of nutritional supplements (antioxidants) are recommendable. Genetic testing may be especially important in patients with a family history of AMD. Recently, unifying criteria for the clinical classification of AMD, defining no apparent aging changes; normal aging changes; and early, intermediate, and late AMD stages, are of value in predicting AMD risk of progression and in establishing recommendations for the diagnosis, therapeutic approach, and follow-up of patients. The present review is focused on early and intermediate AMD and presents a description of the clinical characteristics and ophthalmological findings for these stages, together with algorithms for the diagnosis and management of patients, which are easily applicable in daily clinical practice.

  18. Early and intermediate age-related macular degeneration: update and clinical review

    PubMed Central

    García-Layana, Alfredo; Cabrera-López, Francisco; García-Arumí, José; Arias-Barquet, Lluís; Ruiz-Moreno, José M

    2017-01-01

    Age-related macular degeneration (AMD) is the leading cause of irreversible central vision loss in developed countries. With the aging of population, AMD will become globally an increasingly important and prevalent disease worldwide. It is a complex disease whose etiology is associated with both genetic and environmental risk factors. An extensive decline in the quality of life and progressive need of daily living assistance resulting from AMD among those most severely affected highlights the essential role of preventive strategies, particularly advising patients to quit smoking. In addition, maintaining a healthy diet, controlling other risk factors (such as hypertension, obesity, and atherosclerosis), and the use of nutritional supplements (antioxidants) are recommendable. Genetic testing may be especially important in patients with a family history of AMD. Recently, unifying criteria for the clinical classification of AMD, defining no apparent aging changes; normal aging changes; and early, intermediate, and late AMD stages, are of value in predicting AMD risk of progression and in establishing recommendations for the diagnosis, therapeutic approach, and follow-up of patients. The present review is focused on early and intermediate AMD and presents a description of the clinical characteristics and ophthalmological findings for these stages, together with algorithms for the diagnosis and management of patients, which are easily applicable in daily clinical practice. PMID:29042759

  19. The Progenitor Dependence of Core-collapse Supernovae from Three-dimensional Simulations with Progenitor Models of 12–40 M ⊙

    NASA Astrophysics Data System (ADS)

    Ott, Christian D.; Roberts, Luke F.; da Silva Schneider, André; Fedrow, Joseph M.; Haas, Roland; Schnetter, Erik

    2018-03-01

    We present a first study of the progenitor star dependence of the three-dimensional (3D) neutrino mechanism of core-collapse supernovae. We employ full 3D general-relativistic multi-group neutrino radiation-hydrodynamics and simulate the postbounce evolutions of progenitors with zero-age main sequence masses of 12, 15, 20, 27, and 40 M ⊙. All progenitors, with the exception of the 12 M ⊙ star, experience shock runaway by the end of their simulations. In most cases, a strongly asymmetric explosion will result. We find three qualitatively distinct evolutions that suggest a complex dependence of explosion dynamics on progenitor density structure, neutrino heating, and 3D flow. (1) Progenitors with massive cores, shallow density profiles, and high post-core-bounce accretion rates experience very strong neutrino heating and neutrino-driven turbulent convection, leading to early shock runaway. Accretion continues at a high rate, likely leading to black hole formation. (2) Intermediate progenitors experience neutrino-driven, turbulence-aided explosions triggered by the arrival of density discontinuities at the shock. These occur typically at the silicon/silicon–oxygen shell boundary. (3) Progenitors with small cores and density profiles without strong discontinuities experience shock recession and develop the 3D standing-accretion shock instability (SASI). Shock runaway ensues late, once declining accretion rate, SASI, and neutrino-driven convection create favorable conditions. These differences in explosion times and dynamics result in a non-monotonic relationship between progenitor and compact remnant mass.

  20. Live Imaging at the Onset of Cortical Neurogenesis Reveals Differential Appearance of the Neuronal Phenotype in Apical versus Basal Progenitor Progeny

    PubMed Central

    Attardo, Alessio; Calegari, Federico; Haubensak, Wulf; Wilsch-Bräuninger, Michaela; Huttner, Wieland B.

    2008-01-01

    The neurons of the mammalian brain are generated by progenitors dividing either at the apical surface of the ventricular zone (neuroepithelial and radial glial cells, collectively referred to as apical progenitors) or at its basal side (basal progenitors, also called intermediate progenitors). For apical progenitors, the orientation of the cleavage plane relative to their apical-basal axis is thought to be of critical importance for the fate of the daughter cells. For basal progenitors, the relationship between cell polarity, cleavage plane orientation and the fate of daughter cells is unknown. Here, we have investigated these issues at the very onset of cortical neurogenesis. To directly observe the generation of neurons from apical and basal progenitors, we established a novel transgenic mouse line in which membrane GFP is expressed from the beta-III-tubulin promoter, an early pan-neuronal marker, and crossed this line with a previously described knock-in line in which nuclear GFP is expressed from the Tis21 promoter, a pan-neurogenic progenitor marker. Mitotic Tis21-positive basal progenitors nearly always divided symmetrically, generating two neurons, but, in contrast to symmetrically dividing apical progenitors, lacked apical-basal polarity and showed a nearly randomized cleavage plane orientation. Moreover, the appearance of beta-III-tubulin–driven GFP fluorescence in basal progenitor-derived neurons, in contrast to that in apical progenitor-derived neurons, was so rapid that it suggested the initiation of the neuronal phenotype already in the progenitor. Our observations imply that (i) the loss of apical-basal polarity restricts neuronal progenitors to the symmetric mode of cell division, and that (ii) basal progenitors initiate the expression of neuronal phenotype already before mitosis, in contrast to apical progenitors. PMID:18545663

  1. Role of Lactobacillus Species in the Intermediate Vaginal Flora in Early Pregnancy: A Retrospective Cohort Study

    PubMed Central

    Farr, Alex; Kiss, Herbert; Hagmann, Michael; Machal, Susanne; Holzer, Iris; Kueronya, Verena; Husslein, Peter Wolf; Petricevic, Ljubomir

    2015-01-01

    intermediate vaginal flora in early pregnancy. PMID:26658473

  2. Role of Lactobacillus Species in the Intermediate Vaginal Flora in Early Pregnancy: A Retrospective Cohort Study.

    PubMed

    Farr, Alex; Kiss, Herbert; Hagmann, Michael; Machal, Susanne; Holzer, Iris; Kueronya, Verena; Husslein, Peter Wolf; Petricevic, Ljubomir

    2015-01-01

    Poor obstetrical outcomes are associated with imbalances in the vaginal flora. The present study evaluated the role of vaginal Lactobacillus species in women with intermediate vaginal flora with regard to obstetrical outcomes. We retrospectively analysed data from all women with singleton pregnancies who had undergone routine screening for asymptomatic vaginal infections at our tertiary referral centre between 2005 and 2014. Vaginal smears were Gram-stained and classified according to the Nugent scoring system as normal flora (score 0-3), intermediate vaginal flora (4-6), or bacterial vaginosis (7-10). Only women with intermediate vaginal flora were investigated. Women with a Nugent score of 4 were categorised into those with and without Lactobacilli. Follow-up smears were obtained 4-6 weeks after the initial smears. Descriptive data analysis, the Welch's t-test, the Fisher's exact test, and multiple regression analysis with adjustment for confounders were performed. Gestational age at delivery and birth weight were the outcome measures. At antenatal screening, 529/8421 women presented with intermediate vaginal flora. Amongst these, 349/529 (66%) had a Nugent score of 4, 94/529 (17.8%) a Nugent score of 5, and 86/529 (16.2%) a Nugent score of 6. Amongst those with a Nugent score of 4, 232/349 (66.5%) women were in the Lactobacilli group and 117/349 (33.5%) in the Non-Lactobacilli group. The preterm delivery rate was significantly lower in the Lactobacilli than in the Non-Lactobacilli group (OR 0.34, CI 0.21-0.55; p<0.001). Mean birth weight was 2979 ± 842 g and 2388 ± 1155 g in the study groups, respectively (MD 564.12, CI 346.23-781.92; p<0.001). On follow-up smears, bacterial vaginosis rates were 9% in the Lactobacilli and 7.8% in the Non-Lactobacilli group. The absence of vaginal Lactobacillus species and any bacterial colonisation increases the risks of preterm delivery and low birth weight in women with intermediate vaginal flora in early pregnancy.

  3. Thermal components in the early X-ray afterglows of GRBs: likely cocoon emission and constraints on the progenitors

    NASA Astrophysics Data System (ADS)

    Valan, Vlasta; Larsson, Josefin; Ahlgren, Björn

    2018-02-01

    The early X-ray afterglows of gamma-ray bursts (GRBs) are usually well described by absorbed power laws. However, in some cases, additional thermal components have been identified. The origin of this emission is debated, with proposed explanations including supernova shock breakout, emission from a cocoon surrounding the jet, as well as emission from the jet itself. A larger sample of detections is needed in order to place constraints on these different models. Here, we present a time-resolved spectral analysis of 74 GRBs observed by Swift X-ray Telescope in a search for thermal components. We report six detections in our sample, and also confirm an additional three cases that were previously reported in the literature. The majority of these bursts have a narrow range of blackbody radii around ˜2 × 1012 cm, despite having a large range of luminosities (Lpeak ˜ 1047-1051 erg s-1). This points to an origin connected to the progenitor stars, and we suggest that emission from a cocoon breaking out from a thick wind may explain the observations. For two of the bursts in the sample, an explanation in terms of late prompt emission from the jet is instead more likely. We also find that these thermal components are preferentially detected when the X-ray luminosity is low, which suggests that they may be hidden by bright afterglows in the majority of GRBs.

  4. The loss of the kinases SadA and SadB results in early neuronal apoptosis and a reduced number of progenitors.

    PubMed

    Dhumale, Pratibha; Menon, Sindhu; Chiang, Joanna; Püschel, Andreas W

    2018-01-01

    The neurons that form the mammalian neocortex originate from progenitor cells in the ventricular (VZ) and subventricular zone (SVZ). Newborn neurons are multipolar but become bipolar during their migration from the germinal layers to the cortical plate (CP) by forming a leading process and an axon that extends in the intermediate zone (IZ). Once they settle in the CP, neurons assume a highly polarized morphology with a single axon and multiple dendrites. The AMPK-related kinases SadA and SadB are intrinsic factors that are essential for axon formation during neuronal development downstream of Lkb1. The knockout of both genes encoding Sad kinases (Sada and Sadb) results not only in a loss of axons but also a decrease in the size of the cortical plate. The defect in axon formation has been linked to a function of Sad kinases in the regulation of microtubule binding proteins. However, the causes for the reduced size of the cortical plate in the Sada-/-;Sadb-/- knockout remain to be analyzed in detail. Here we show that neuronal cell death is increased and the number of neural progenitors is decreased in the Sada-/-;Sadb-/- CP. The reduced number of progenitors is a non-cell autonomous defect since they do not express Sad kinases. These defects are restricted to the neocortex while the hippocampus remains unaffected.

  5. Caudal migration and proliferation of renal progenitors regulates early nephron segment size in zebrafish.

    PubMed

    Naylor, Richard W; Dodd, Rachel C; Davidson, Alan J

    2016-10-19

    The nephron is the functional unit of the kidney and is divided into distinct proximal and distal segments. The factors determining nephron segment size are not fully understood. In zebrafish, the embryonic kidney has long been thought to differentiate in situ into two proximal tubule segments and two distal tubule segments (distal early; DE, and distal late; DL) with little involvement of cell movement. Here, we overturn this notion by performing lineage-labelling experiments that reveal extensive caudal movement of the proximal and DE segments and a concomitant compaction of the DL segment as it fuses with the cloaca. Laser-mediated severing of the tubule, such that the DE and DL are disconnected or that the DL and cloaca do not fuse, results in a reduction in tubule cell proliferation and significantly shortens the DE segment while the caudal movement of the DL is unaffected. These results suggest that the DL mechanically pulls the more proximal segments, thereby driving both their caudal extension and their proliferation. Together, these data provide new insights into early nephron morphogenesis and demonstrate the importance of cell movement and proliferation in determining initial nephron segment size.

  6. Structure of GroEL in Complex with an Early Folding Intermediate of Alanine Glyoxylate Aminotransferase*

    PubMed Central

    Albert, Armando; Yunta, Cristina; Arranz, Rocío; Peña, Álvaro; Salido, Eduardo; Valpuesta, José María; Martín-Benito, Jaime

    2010-01-01

    Primary hyperoxaluria type 1 is a rare autosomal recessive disease caused by mutations in the alanine glyoxylate aminotransferase gene (AGXT). We have previously shown that P11L and I340M polymorphisms together with I244T mutation (AGXT-LTM) represent a conformational disease that could be amenable to pharmacological intervention. Thus, the study of the folding mechanism of AGXT is crucial to understand the molecular basis of the disease. Here, we provide biochemical and structural data showing that AGXT-LTM is able to form non-native folding intermediates. The three-dimensional structure of a complex between the bacterial chaperonin GroEL and a folding intermediate of AGXT-LTM mutant has been solved by cryoelectron microscopy. The electron density map shows the protein substrate in a non-native extended conformation that crosses the GroEL central cavity. Addition of ATP to the complex induces conformational changes on the chaperonin and the internalization of the protein substrate into the folding cavity. The structure provides a three-dimensional picture of an in vivo early ATP-dependent step of the folding reaction cycle of the chaperonin and supports a GroEL functional model in which the chaperonin promotes folding of the AGXT-LTM mutant protein through forced unfolding mechanism. PMID:20056599

  7. Structure of GroEL in complex with an early folding intermediate of alanine glyoxylate aminotransferase.

    PubMed

    Albert, Armando; Yunta, Cristina; Arranz, Rocío; Peña, Alvaro; Salido, Eduardo; Valpuesta, José María; Martín-Benito, Jaime

    2010-02-26

    Primary hyperoxaluria type 1 is a rare autosomal recessive disease caused by mutations in the alanine glyoxylate aminotransferase gene (AGXT). We have previously shown that P11L and I340M polymorphisms together with I244T mutation (AGXT-LTM) represent a conformational disease that could be amenable to pharmacological intervention. Thus, the study of the folding mechanism of AGXT is crucial to understand the molecular basis of the disease. Here, we provide biochemical and structural data showing that AGXT-LTM is able to form non-native folding intermediates. The three-dimensional structure of a complex between the bacterial chaperonin GroEL and a folding intermediate of AGXT-LTM mutant has been solved by cryoelectron microscopy. The electron density map shows the protein substrate in a non-native extended conformation that crosses the GroEL central cavity. Addition of ATP to the complex induces conformational changes on the chaperonin and the internalization of the protein substrate into the folding cavity. The structure provides a three-dimensional picture of an in vivo early ATP-dependent step of the folding reaction cycle of the chaperonin and supports a GroEL functional model in which the chaperonin promotes folding of the AGXT-LTM mutant protein through forced unfolding mechanism.

  8. Morphological and proteomic analysis of early stage of osteoblast differentiation in osteoblastic progenitor cells

    SciTech Connect

    Hong, Dun; Orthopedic Department, Taizhou Hospital, Wenzhou Medical College, Linhai, Zhejiang 317000; Chen, Hai-Xiao, E-mail: Hxchen-1@163.net

    Bone remodeling relies on a dynamic balance between bone formation and resorption, mediated by osteoblasts and osteoclasts, respectively. Under certain stimuli, osteoprogenitor cells may differentiate into premature osteoblasts and further into mature osteoblasts. This process is marked by increased alkaline phosphatase (ALP) activity and mineralized nodule formation. In this study, we induced osteoblast differentiation in mouse osteoprogenitor MC3T3-E1 cells and divided the process into three stages. In the first stage (day 3), the MC3T3-E1 cell under osteoblast differentiation did not express ALP or deposit a mineralized nodule. In the second stage, the MC3T3-E1 cell expressed ALP but did not formmore » a mineralized nodule. In the third stage, the MC3T3-E1 cell had ALP activity and formed mineralized nodules. In the present study, we focused on morphological and proteomic changes of MC3T3-E1 cells in the early stage of osteoblast differentiation - a period when premature osteoblasts transform into mature osteoblasts. We found that mean cell area and mean stress fiber density were increased in this stage due to enhanced cell spreading and decreased cell proliferation. We further analyzed the proteins in the signaling pathway of regulation of the cytoskeleton using a proteomic approach and found upregulation of IQGAP1, gelsolin, moesin, radixin, and Cfl1. After analyzing the focal adhesion signaling pathway, we found the upregulation of FLNA, LAMA1, LAMA5, COL1A1, COL3A1, COL4A6, and COL5A2 as well as the downregulation of COL4A1, COL4A2, and COL4A4. In conclusion, the signaling pathway of regulation of the cytoskeleton and focal adhesion play critical roles in regulating cell spreading and actin skeleton formation in the early stage of osteoblast differentiation.« less

  9. Early-time spectra of supernovae and their precursor winds. The luminous blue variable/yellow hypergiant progenitor of SN 2013cu

    NASA Astrophysics Data System (ADS)

    Groh, Jose H.

    2014-12-01

    We present the first quantitative spectroscopic modeling of an early-time supernova (SN) that interacts with its progenitor wind. Using the radiative transfer code CMFGEN, we investigate the recently reported 15.5 h post-explosion spectrum of the type IIb SN 2013cu. We are able to directly measure the chemical abundances of a SN progenitor and find a relatively H-rich wind, with H and He abundances (by mass) of X = 0.46 ± 0.2 and Y = 0.52 ± 0.2, respectively. The wind is enhanced in N and depleted in C relative to solar values (mass fractions of 8.2 × 10-3 and 1.0 × 10-5, respectively). We obtain that a slow, dense wind or circumstellar medium surrounds the precursor at the pre-SN stage, with a wind terminal velocity vwind ≲ 100 km s-1 and mass-loss rate of Ṁ ≃ 3 × 10-3 (vwind/ 100 km s-1) M⊙ yr-1. These values are lower than previous analytical estimates, although Ṁ/υ∞ is consistent with previous work. We also compute a CMFGEN model to constrain the progenitor spectral type; the high Ṁ and low vwind imply that the star had an effective temperature of ≃ 8000 K immediately before the SN explosion. Our models suggest that the progenitor was either an unstable luminous blue variable or a yellow hypergiant undergoing an eruptive phase, and rule out a Wolf-Rayet star. We classify the post-explosion spectra at 15.5 h as XWN5(h) and advocate for the use of the prefix "X" (eXplosion) to avoid confusion between post-explosion, non-stellar spectra, and those of massive stars. We show that the XWN spectrum results from the ionization of the progenitor wind after the SN, and that the progenitor spectral type is significantly different from the early post-explosion spectral type owing to the huge differences in the ionization structure before and after the SN event. We find the following temporal evolution: LBV/YHG → XWN5(h) → SN IIb. Future early-time spectroscopy in the UV will further constrain the properties of SN precursors, such as their

  10. Optimal Timing for Elective Early Primary Repair of Tetralogy of Fallot: Analysis of Intermediate Term Outcomes.

    PubMed

    Cunningham, Michael E A; Donofrio, Mary T; Peer, Syed Murfad; Zurakowski, David; Jonas, Richard A; Sinha, Pranava

    2017-03-01

    We have previously demonstrated that early primary repair of tetralogy of Fallot with pulmonary stenosis (TOF) can be safely performed without increase in hospital resource utilization or compromise to surgical technical performance scores (TPS). We sought to identify the optimal timing for elective early primary repair of TOF with respect to intermediate-term reintervention. Retrospective review of all patients with TOF undergoing elective primary repair between September 2004 and December 2013 was performed. Patients were stratified into reintervention group or no reintervention group. Multivariable Cox regression analysis identified independent predictors of reintervention. Youden's J-index in receiver operating characteristic analysis identified optimal age cutoff predictive of reintervention. Kaplan-Meier analysis with the log-rank test compared reintervention rates stratified by age and TPS. A total of 129 patients with median (interquartile range) age and weight of 78 days (56 to 111) and 5 kg (4.1 to 5.7), respectively, underwent primary repair. After a median (interquartile range) follow-up of 2.3 years (0.1 to 4.6), 18 patients (14%) required a total of 22 reinterventions. Youden's J-index revealed significantly lower risk of intermediate-term reintervention when repaired after 55 days of age (8% for >55 days old versus 31% for ≤55 days of age). Multivariable Cox regression identified age 55 days and younger (hazard ratio [HR] 4.5, 95% confidence interval [CI] 1.6 to 12.8, p = 0.004), valve sparing repair (HR 15.3, 95% CI 1.8 to 128.5, p < 0.001), residual right ventricular outflow tract (RVOT) gradient (HR 1.11, 95% CI 1.1 to 1.2, p < 0.001), and inadequate TPS (HR 21.5, 95% CI 7.4 to 63, p < 0.001) as independent predictors of overall intermediate-term reintervention. Elective repair in patients greater than 55 days of age, irrespective of size of the patient, can be safely performed without any increase in reintervention rates. Both residual peak

  11. Interleukin-6 inhibits early differentiation of ATDC5 chondrogenic progenitor cells.

    PubMed

    Nakajima, Shoko; Naruto, Takuya; Miyamae, Takako; Imagawa, Tomoyuki; Mori, Masaaki; Nishimaki, Shigeru; Yokota, Shumpei

    2009-08-01

    Interleukin (IL)-6 is a causative agent of systemic juvenile idiopathic arthritis (sJIA), a chronic inflammatory disease complicated with severe growth impairment. Recent trials of anti-IL-6 receptor monoclonal antibody, tocilizumab, indicated that tocilizumab blocks IL-6/IL-6 receptor-mediated inflammation, and induces catch-up growth in children with sJIA. This study evaluates the effects of IL-6 on chondrogenesis by ATDC5 cells, a clonal murine chondrogenic cell line that provides an excellent model for studying endochondral ossification at growth plate. ATDC5 cells were examined for the expression of IL-6 receptor and gp130 by fluorescence-activated cell sorting analysis. Recombinant murine IL-6 was added to ATDC5 cultures to observe cell differentiation, using a quantitative RT-PCR for the chondrogenic differentiation markers type II collagen, aggrecan, and type X collagen. To block IL-6, the anti-mouse IL-6 receptor monoclonal antibody MR16-1 was added. As a result, the cells expressed IL-6 receptor and gp130. The expression of chondrogenic differentiation marker gene was reduced by IL-6, but this was abrogated by MR16-1. We conclude that IL-6 inhibits early chondrogenesis of ATDC5 cells suggesting that IL-6 may affect committed stem cells at a cellular level during chondrogenic differentiation of growth plate chondrocytes, and that IL-6 may be a cellular-level factor in growth impairment in sJIA.

  12. Mesenchymal progenitor cells for the osteogenic lineage.

    PubMed

    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.

  13. Gene–Environment Interactions and Intermediate Phenotypes: Early Trauma and Depression

    PubMed Central

    Hornung, Orla P.; Heim, Christine M.

    2013-01-01

    This review focuses on current research developments in the study of gene by early life stress (ELS) interactions and depression. ELS refers to aversive experiences during childhood and adolescence such as sexual, physical or emotional abuse, emotional or physical neglect as well as parental loss. Previous research has focused on investigating and characterizing the specific role of ELS within the pathogenesis of depression and linking these findings to neurobiological changes of the brain, especially the stress response system. The latest findings highlight the role of genetic factors that increase vulnerability or, likewise, promote resilience to depression after childhood trauma. Considering intermediate phenotypes has further increased our understanding of the complex relationship between early trauma and depression. Recent findings with regard to epigenetic changes resulting from adverse environmental events during childhood promote current endeavors to identify specific target areas for prevention and treatment schemes regarding the long-term impact of ELS. Taken together, the latest research findings have underscored the essential role of genotypes and epigenetic processes within the development of depression after childhood trauma, thereby building the basis for future research and clinical interventions. PMID:24596569

  14. Visual Function Metrics in Early and Intermediate Dry Age-related Macular Degeneration for Use as Clinical Trial Endpoints.

    PubMed

    Cocce, Kimberly J; Stinnett, Sandra S; Luhmann, Ulrich F O; Vajzovic, Lejla; Horne, Anupama; Schuman, Stefanie G; Toth, Cynthia A; Cousins, Scott W; Lad, Eleonora M

    2018-05-01

    To evaluate and quantify visual function metrics to be used as endpoints of age-related macular degeneration (AMD) stages and visual acuity (VA) loss in patients with early and intermediate AMD. Cross-sectional analysis of baseline data from a prospective study. One hundred and one patients were enrolled at Duke Eye Center: 80 patients with early AMD (Age-Related Eye Disease Study [AREDS] stage 2 [n = 33] and intermediate stage 3 [n = 47]) and 21 age-matched, normal controls. A dilated retinal examination, macular pigment optical density measurements, and several functional assessments (best-corrected visual acuity, macular integrity assessment mesopic microperimety, dark adaptometry, low-luminance visual acuity [LLVA] [standard using a log 2.0 neutral density filter and computerized method], and cone contrast test [CCT]) were performed. Low-luminance deficit (LLD) was defined as the difference in numbers of letters read at standard vs low luminance. Group comparisons were performed to evaluate differences between the control and the early and intermediate AMD groups using 2-sided significance tests. Functional measures that significantly distinguished between normal and intermediate AMD were standard and computerized (0.5 cd/m 2 ) LLVA, percent reduced threshold and average threshold on microperimetry, CCTs, and rod intercept on dark adaptation (P < .05). The intermediate group demonstrated deficits in microperimetry reduced threshhold, computerized LLD2, and dark adaptation (P < .05) relative to early AMD. Our study suggests that LLVA, microperimetry, CCT, and dark adaptation may serve as functional measures differentiating early-to-intermediate stages of dry AMD. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Evidence for close side-chain packing in an early protein folding intermediate previously assumed to be a molten globule

    PubMed Central

    Rosen, Laura E.; Connell, Katelyn B.; Marqusee, Susan

    2014-01-01

    The molten globule, a conformational ensemble with significant secondary structure but only loosely packed tertiary structure, has been suggested to be a ubiquitous intermediate in protein folding. However, it is difficult to assess the tertiary packing of transiently populated species to evaluate this hypothesis. Escherichia coli RNase H is known to populate an intermediate before the rate-limiting barrier to folding that has long been thought to be a molten globule. We investigated this hypothesis by making mimics of the intermediate that are the ground-state conformation at equilibrium, using two approaches: a truncation to generate a fragment mimic of the intermediate, and selective destabilization of the native state using point mutations. Spectroscopic characterization and the response of the mimics to further mutation are consistent with studies on the transient kinetic intermediate, indicating that they model the early intermediate. Both mimics fold cooperatively and exhibit NMR spectra indicative of a closely packed conformation, in contrast to the hypothesis of molten tertiary packing. This result is important for understanding the nature of the subsequent rate-limiting barrier to folding and has implications for the assumption that many other proteins populate molten globule folding intermediates. PMID:25258414

  16. Evidence for close side-chain packing in an early protein folding intermediate previously assumed to be a molten globule.

    PubMed

    Rosen, Laura E; Connell, Katelyn B; Marqusee, Susan

    2014-10-14

    The molten globule, a conformational ensemble with significant secondary structure but only loosely packed tertiary structure, has been suggested to be a ubiquitous intermediate in protein folding. However, it is difficult to assess the tertiary packing of transiently populated species to evaluate this hypothesis. Escherichia coli RNase H is known to populate an intermediate before the rate-limiting barrier to folding that has long been thought to be a molten globule. We investigated this hypothesis by making mimics of the intermediate that are the ground-state conformation at equilibrium, using two approaches: a truncation to generate a fragment mimic of the intermediate, and selective destabilization of the native state using point mutations. Spectroscopic characterization and the response of the mimics to further mutation are consistent with studies on the transient kinetic intermediate, indicating that they model the early intermediate. Both mimics fold cooperatively and exhibit NMR spectra indicative of a closely packed conformation, in contrast to the hypothesis of molten tertiary packing. This result is important for understanding the nature of the subsequent rate-limiting barrier to folding and has implications for the assumption that many other proteins populate molten globule folding intermediates.

  17. Very early reaction intermediates detected by microsecond time scale kinetics of cytochrome cd1-catalyzed reduction of nitrite.

    PubMed

    Sam, Katharine A; Strampraad, Marc J F; de Vries, Simon; Ferguson, Stuart J

    2008-10-10

    Paracoccus pantotrophus cytochrome cd(1) is a nitrite reductase found in the periplasm of many denitrifying bacteria. It catalyzes the reduction of nitrite to nitric oxide during the denitrification part of the biological nitrogen cycle. Previous studies of early millisecond intermediates in the nitrite reduction reaction have shown, by comparison with pH 7.0, that at the optimum pH, approximately pH 6, the earliest intermediates were lost in the dead time of the instrument. Access to early time points (approximately 100 micros) through use of an ultra-rapid mixing device has identified a spectroscopically novel intermediate, assigned as the Michaelis complex, formed from reaction of fully reduced enzyme with nitrite. Spectroscopic observation of the subsequent transformation of this species has provided data that demand reappraisal of the general belief that the two subunits of the enzyme function independently.

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

    PubMed

    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.

  19. Demonstration of early functional compromise of bone marrow derived hematopoietic progenitor cells during bovine neonatal pancytopenia through in vitro culture of bone marrow biopsies.

    PubMed

    Laming, Eleanor; Melzi, Eleonora; Scholes, Sandra F E; Connelly, Maira; Bell, Charlotte R; Ballingall, Keith T; Dagleish, Mark P; Rocchi, Mara S; Willoughby, Kim

    2012-10-30

    Bovine neonatal pancytopenia (BNP) is a syndrome characterised by thrombocytopenia associated with marked bone marrow destruction in calves, widely reported since 2007 in several European countries and since 2011 in New Zealand. The disease is epidemiologically associated with the use of an inactivated bovine virus diarrhoea (BVD) vaccine and is currently considered to be caused by absorption of colostral antibody produced by some vaccinated cows ("BNP dams"). Alloantibodies capable of binding to the leukocyte surface have been detected in BNP dams and antibodies recognising bovine MHC class I and β-2-microglobulin have been detected in vaccinated cattle. In this study, calves were challenged with pooled colostrum collected from BNP dams or from non-BNP dams and their bone marrow hematopoietic progenitor cells (HPC) cultured in vitro from sternal biopsies taken at 24 hours and 6 days post-challenge. Clonogenic assay demonstrated that CFU-GEMM (colony forming unit-granulocyte/erythroid/macrophage/megakaryocyte; pluripotential progenitor cell) colony development was compromised from HPCs harvested as early as 24 hour post-challenge. By 6 days post challenge, HPCs harvested from challenged calves failed to develop CFU-E (erythroid) colonies and the development of both CFU-GEMM and CFU-GM (granulocyte/macrophage) was markedly reduced. This study suggests that the bone marrow pathology and clinical signs associated with BNP are related to an insult which compromises the pluripotential progenitor cell within the first 24 hours of life but that this does not initially include all cell types.

  20. Chloroplast precursor proteins compete to form early import intermediates in isolated pea chloroplasts.

    PubMed

    Row, P E; Gray, J C

    2001-01-01

    In order to ascertain whether there is one site for the import of precursor proteins into chloroplasts or whether different precursor proteins are imported via different import machineries, chloroplasts were incubated with large quantities of the precursor of the 33 kDa subunit of the oxygen-evolving complex (pOE33) or the precursor of the light-harvesting chlorophyll a/b-binding protein (pLHCP) and tested for their ability to import a wide range of other chloroplast precursor proteins. Both pOE33 and pLHCP competed for import into chloroplasts with precursors of the stromally-targeted small subunit of Rubisco (pSSu), ferredoxin NADP(+) reductase (pFNR) and porphobilinogen deaminase; the thylakoid membrane proteins LHCP and the Rieske iron-sulphur protein (pRieske protein); ferrochelatase and the gamma subunit of the ATP synthase (which are both associated with the thylakoid membrane); the thylakoid lumenal protein plastocyanin and the phosphate translocator, an integral membrane protein of the inner envelope. The concentrations of pOE33 or pLHCP required to cause half-maximal inhibition of import ranged between 0.2 and 4.9 microM. These results indicate that all of these proteins are imported into the chloroplast by a common import machinery. Incubation of chloroplasts with pOE33 inhibited the formation of early import intermediates of pSSu, pFNR and pRieske protein.

  1. Heparan sulfates and the decrease of N-glycans promote early adipogenic differentiation rather than myogenesis of murine myogenic progenitor cells.

    PubMed

    Grassot, Vincent; Bouchatal, Amel; Da Silva, Anne; Chantepie, Sandrine; Papy-Garcia, Dulce; Maftah, Abderrahman; Gallet, Paul-François; Petit, Jean-Michel

    In vitro, extracted muscle satellite cells, called myogenic progenitor cells, can differentiate either in myotubes or preadipocytes, depending on environmental factors and the medium. Transcriptomic analyses on glycosylation genes during satellite cells differentiation into myotubes showed that 31 genes present a significant variation of expression at the early stages of murine myogenic progenitor cells (MPC) differentiation. In the present study, we analyzed the expression of 383 glycosylation related genes during murine MPC differentiation into preadipocytes and compared the data to those previously obtained during their differentiation into myotubes. Fifty-six glycosylation related genes are specifically modified in their expression during early adipogenesis. The variations correspond mainly to: a decrease of N-glycans, and of alpha (2,3) and (2,6) linked sialic acids, and to a high level of heparan sulfates. A high amount of TGF-β1 in extracellular media during early adipogenesis was also observed. It seems that the increases of heparan sulfates and TGF-β1 favor pre-adipogenic differentition of MPC and possibly prevent their myogenic differentiation. Copyright © 2016 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

  2. Associations of personal and family preeclampsia history with the risk of early-, intermediate- and late-onset preeclampsia.

    PubMed

    Boyd, Heather A; Tahir, Hassaan; Wohlfahrt, Jan; Melbye, Mads

    2013-12-01

    Preeclampsia encompasses multiple conditions of varying severity. We examined the recurrence and familial aggregation of preeclampsia by timing of onset, which is a marker for severity. We ascertained personal and family histories of preeclampsia for women who delivered live singletons in Denmark in 1978-2008 (almost 1.4 million pregnancies). Using log-linear binomial regression, we estimated risk ratios for the associations between personal and family histories of preeclampsia and the risk of early-onset (before 34 weeks of gestation, which is typically the most severe), intermediate-onset (at 34-36 weeks of gestation), and late-onset (after 36 weeks of gestation) preeclampsia. Previous early-, intermediate-, or late-onset preeclampsia increased the risk of recurrent preeclampsia with the same timing of onset 25.2 times (95% confidence interval (CI): 21.8, 29.1), 19.7 times (95% CI: 17.0, 22.8), and 10.3 times (95% CI: 9.85, 10.9), respectively, compared with having no such history. Preeclampsia in a woman's family was associated with a 24%-163% increase in preeclampsia risk, with the strongest associations for early- and intermediate-onset preeclampsia in female relatives. Preeclampsia in the man's family did not affect a woman's risk of early-onset preeclampsia and was only weakly associated with her risks of intermediate- and late-onset preeclampsia. Early-onset preeclampsia appears to have the largest genetic component, whereas environmental factors likely contribute most to late-onset preeclampsia. The role of paternal genes in the etiology of preeclampsia appears to be limited.

  3. Extended flow cytometry characterization of normal bone marrow progenitor cells by simultaneous detection of aldehyde dehydrogenase and early hematopoietic antigens: implication for erythroid differentiation studies

    PubMed Central

    Mirabelli, Peppino; Di Noto, Rosa; Lo Pardo, Catia; Morabito, Paolo; Abate, Giovanna; Gorrese, Marisa; Raia, Maddalena; Pascariello, Caterina; Scalia, Giulia; Gemei, Marica; Mariotti, Elisabetta; Del Vecchio, Luigi

    2008-01-01

    Background Aldehyde dehydrogenase (ALDH) is a cytosolic enzyme highly expressed in hematopoietic precursors from cord blood and granulocyte-colony stimulating factor mobilized peripheral blood, as well as in bone marrow from patients with acute myeloblastic leukemia. As regards human normal bone marrow, detailed characterization of ALDH+ cells has been addressed by one single study (Gentry et al, 2007). The goal of our work was to provide new information about the dissection of normal bone marrow progenitor cells based upon the simultaneous detection by flow cytometry of ALDH and early hematopoietic antigens, with particular attention to the expression of ALDH on erythroid precursors. To this aim, we used three kinds of approach: i) multidimensional analytical flow cytometry, detecting ALDH and early hematopoietic antigens in normal bone marrow; ii) fluorescence activated cell sorting of distinct subpopulations of progenitor cells, followed by in vitro induction of erythroid differentiation; iii) detection of ALDH+ cellular subsets in bone marrow from pure red cell aplasia patients. Results In normal bone marrow, we identified three populations of cells, namely ALDH+CD34+, ALDH-CD34+ and ALDH+CD34- (median percentages were 0.52, 0.53 and 0.57, respectively). As compared to ALDH-CD34+ cells, ALDH+CD34+ cells expressed the phenotypic profile of primitive hematopoietic progenitor cells, with brighter expression of CD117 and CD133, accompanied by lower display of CD38 and CD45RA. Of interest, ALDH+CD34- population disclosed a straightforward erythroid commitment, on the basis of three orders of evidences. First of all, ALDH+CD34- cells showed a CD71bright, CD105+, CD45- phenotype. Secondly, induction of differentiation experiments evidenced a clear-cut expression of glycophorin A (CD235a). Finally, ALDH+CD34- precursors were not detectable in patients with pure red cell aplasia (PRCA). Conclusion Our study, comparing surface antigen expression of ALDH+/CD34+, ALDH

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

    PubMed Central

    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

  5. Progenitor Epithelium

    PubMed Central

    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

  6. UMG Lenti: Novel Lentiviral Vectors for Efficient Transgene- and Reporter Gene Expression in Human Early Hematopoietic Progenitors

    PubMed Central

    Chiarella, Emanuela; Carrà, Giovanna; Scicchitano, Stefania; Codispoti, Bruna; Mega, Tiziana; Lupia, Michela; Pelaggi, Daniela; Marafioti, Maria G.; Aloisio, Annamaria; Giordano, Marco; Nappo, Giovanna; Spoleti, Cristina B.; Grillone, Teresa; Giovannone, Emilia D.; Spina, Raffaella; Bernaudo, Francesca; Moore, Malcolm A. S.; Bond, Heather M.; Mesuraca, Maria; Morrone, Giovanni

    2014-01-01

    Lentiviral vectors are widely used to investigate the biological properties of regulatory proteins and/or of leukaemia-associated oncogenes by stably enforcing their expression in hematopoietic stem and progenitor cells. In these studies it is critical to be able to monitor and/or sort the infected cells, typically via fluorescent proteins encoded by the modified viral genome. The most popular strategy to ensure co-expression of transgene and reporter gene is to insert between these cDNAs an IRES element, thus generating bi-cistronic mRNAs whose transcription is driven by a single promoter. However, while the product of the gene located upstream of the IRES is generally abundantly expressed, the translation of the downstream cDNA (typically encoding the reporter protein) is often inconsistent, which hinders the detection and the isolation of transduced cells. To overcome these limitations, we developed novel lentiviral dual-promoter vectors (named UMG-LV5 and –LV6) where transgene expression is driven by the potent UBC promoter and that of the reporter protein, EGFP, by the minimal regulatory element of the WASP gene. These vectors, harboring two distinct transgenes, were tested in a variety of human haematopoietic cell lines as well as in primary human CD34+ cells in comparison with the FUIGW vector that contains the expression cassette UBC-transgene-IRES-EGFP. In these experiments both UMG-LV5 and UMG–LV6 yielded moderately lower transgene expression than FUIGW, but dramatically higher levels of EGFP, thereby allowing the easy distinction between transduced and non-transduced cells. An additional construct was produced, in which the cDNA encoding the reporter protein is upstream, and the transgene downstream of the IRES sequence. This vector, named UMG-LV11, proved able to promote abundant expression of both transgene product and EGFP in all cells tested. The UMG-LVs represent therefore useful vectors for gene transfer-based studies in hematopoietic stem and

  7. UMG Lenti: novel lentiviral vectors for efficient transgene- and reporter gene expression in human early hematopoietic progenitors.

    PubMed

    Chiarella, Emanuela; Carrà, Giovanna; Scicchitano, Stefania; Codispoti, Bruna; Mega, Tiziana; Lupia, Michela; Pelaggi, Daniela; Marafioti, Maria G; Aloisio, Annamaria; Giordano, Marco; Nappo, Giovanna; Spoleti, Cristina B; Grillone, Teresa; Giovannone, Emilia D; Spina, Raffaella; Bernaudo, Francesca; Moore, Malcolm A S; Bond, Heather M; Mesuraca, Maria; Morrone, Giovanni

    2014-01-01

    Lentiviral vectors are widely used to investigate the biological properties of regulatory proteins and/or of leukaemia-associated oncogenes by stably enforcing their expression in hematopoietic stem and progenitor cells. In these studies it is critical to be able to monitor and/or sort the infected cells, typically via fluorescent proteins encoded by the modified viral genome. The most popular strategy to ensure co-expression of transgene and reporter gene is to insert between these cDNAs an IRES element, thus generating bi-cistronic mRNAs whose transcription is driven by a single promoter. However, while the product of the gene located upstream of the IRES is generally abundantly expressed, the translation of the downstream cDNA (typically encoding the reporter protein) is often inconsistent, which hinders the detection and the isolation of transduced cells. To overcome these limitations, we developed novel lentiviral dual-promoter vectors (named UMG-LV5 and -LV6) where transgene expression is driven by the potent UBC promoter and that of the reporter protein, EGFP, by the minimal regulatory element of the WASP gene. These vectors, harboring two distinct transgenes, were tested in a variety of human haematopoietic cell lines as well as in primary human CD34+ cells in comparison with the FUIGW vector that contains the expression cassette UBC-transgene-IRES-EGFP. In these experiments both UMG-LV5 and UMG-LV6 yielded moderately lower transgene expression than FUIGW, but dramatically higher levels of EGFP, thereby allowing the easy distinction between transduced and non-transduced cells. An additional construct was produced, in which the cDNA encoding the reporter protein is upstream, and the transgene downstream of the IRES sequence. This vector, named UMG-LV11, proved able to promote abundant expression of both transgene product and EGFP in all cells tested. The UMG-LVs represent therefore useful vectors for gene transfer-based studies in hematopoietic stem and

  8. Galactic rings revisited. II. Dark gaps and the locations of resonances in early-to-intermediate-type disc galaxies

    NASA Astrophysics Data System (ADS)

    Buta, Ronald J.

    2017-10-01

    Dark gaps are commonly seen in early-to-intermediate-type barred galaxies having inner and outer rings or related features. In this paper, the morphologies of 54 barred and oval ringed galaxies have been examined with the goal of determining what the dark gaps are telling us about the structure and evolution of barred galaxies. The analysis is based mainly on galaxies selected from the Galaxy Zoo 2 data base and the Catalogue of Southern Ringed Galaxies. The dark gaps between inner and outer rings are of interest because of their likely association with the L4 and L5 Lagrangian points that would be present in the gravitational potential of a bar or oval. Since the points are theoretically expected to lie very close to the corotation resonance (CR) of the bar pattern, the gaps provide the possibility of locating corotation in some galaxies simply by measuring the radius rgp of the gap region and setting rCR=rgp. With the additional assumption of generally flat rotation curves, the locations of other resonances can be predicted and compared with observed morphological features. It is shown that this `gap method' provides remarkably consistent interpretations of the morphology of early-to-intermediate-type barred galaxies. The paper also brings attention to cases where the dark gaps lie inside an inner ring, rather than between inner and outer rings. These may have a different origin compared to the inner/outer ring gaps.

  9. Early spatiotemporal-specific changes in intermediate signals are predictive of cytotoxic sensitivity to TNFα and co-treatments

    PubMed Central

    Loo, Lit-Hsin; Bougen-Zhukov, Nicola Michelle; Tan, Wei-Ling Cecilia

    2017-01-01

    Signaling pathways can generate different cellular responses to the same cytotoxic agents. Current quantitative models for predicting these differential responses are usually based on large numbers of intracellular gene products or signals at different levels of signaling cascades. Here, we report a study to predict cellular sensitivity to tumor necrosis factor alpha (TNFα) using high-throughput cellular imaging and machine-learning methods. We measured and compared 1170 protein phosphorylation events in a panel of human lung cancer cell lines based on different signals, subcellular regions, and time points within one hour of TNFα treatment. We found that two spatiotemporal-specific changes in an intermediate signaling protein, p90 ribosomal S6 kinase (RSK), are sufficient to predict the TNFα sensitivity of these cell lines. Our models could also predict the combined effects of TNFα and other kinase inhibitors, many of which are not known to target RSK directly. Therefore, early spatiotemporal-specific changes in intermediate signals are sufficient to represent the complex cellular responses to these perturbations. Our study provides a general framework for the development of rapid, signaling-based cytotoxicity screens that may be used to predict cellular sensitivity to a cytotoxic agent, or identify co-treatments that may sensitize or desensitize cells to the agent. PMID:28272488

  10. Early spatiotemporal-specific changes in intermediate signals are predictive of cytotoxic sensitivity to TNFα and co-treatments

    NASA Astrophysics Data System (ADS)

    Loo, Lit-Hsin; Bougen-Zhukov, Nicola Michelle; Tan, Wei-Ling Cecilia

    2017-03-01

    Signaling pathways can generate different cellular responses to the same cytotoxic agents. Current quantitative models for predicting these differential responses are usually based on large numbers of intracellular gene products or signals at different levels of signaling cascades. Here, we report a study to predict cellular sensitivity to tumor necrosis factor alpha (TNFα) using high-throughput cellular imaging and machine-learning methods. We measured and compared 1170 protein phosphorylation events in a panel of human lung cancer cell lines based on different signals, subcellular regions, and time points within one hour of TNFα treatment. We found that two spatiotemporal-specific changes in an intermediate signaling protein, p90 ribosomal S6 kinase (RSK), are sufficient to predict the TNFα sensitivity of these cell lines. Our models could also predict the combined effects of TNFα and other kinase inhibitors, many of which are not known to target RSK directly. Therefore, early spatiotemporal-specific changes in intermediate signals are sufficient to represent the complex cellular responses to these perturbations. Our study provides a general framework for the development of rapid, signaling-based cytotoxicity screens that may be used to predict cellular sensitivity to a cytotoxic agent, or identify co-treatments that may sensitize or desensitize cells to the agent.

  11. Successful In Vitro Expansion and Differentiation of Cord Blood Derived CD34+ Cells into Early Endothelial Progenitor Cells Reveals Highly Differential Gene Expression

    PubMed Central

    Topcic, Denijal; Haviv, Izhak; Merivirta, Ruusu-Maaria; Agrotis, Alexander; Leitner, Ephraem; Jowett, Jeremy B.; Bode, Christoph; Lappas, Martha; Peter, Karlheinz

    2011-01-01

    Endothelial progenitor cells (EPCs) can be purified from peripheral blood, bone marrow or cord blood and are typically defined by a limited number of cell surface markers and a few functional tests. A detailed in vitro characterization is often restricted by the low cell numbers of circulating EPCs. Therefore in vitro culturing and expansion methods are applied, which allow at least distinguishing two different types of EPCs, early and late EPCs. Herein, we describe an in vitro culture technique with the aim to generate high numbers of phenotypically, functionally and genetically defined early EPCs from human cord blood. Characterization of EPCs was done by flow cytometry, immunofluorescence microscopy, colony forming unit (CFU) assay and endothelial tube formation assay. There was an average 48-fold increase in EPC numbers. EPCs expressed VEGFR-2, CD144, CD18, and CD61, and were positive for acetylated LDL uptake and ulex lectin binding. The cells stimulated endothelial tube formation only in co-cultures with mature endothelial cells and formed CFUs. Microarray analysis revealed highly up-regulated genes, including LL-37 (CAMP), PDK4, and alpha-2-macroglobulin. In addition, genes known to be associated with cardioprotective (GDF15) or pro-angiogenic (galectin-3) properties were also significantly up-regulated after a 72 h differentiation period on fibronectin. We present a novel method that allows to generate high numbers of phenotypically, functionally and genetically characterized early EPCs. Furthermore, we identified several genes newly linked to EPC differentiation, among them LL-37 (CAMP) was the most up-regulated gene. PMID:21858032

  12. Interactions of non-detergent sulfobetaines with early folding intermediates facilitate in vitro protein renaturation.

    PubMed

    Vuillard, L; Rabilloud, T; Goldberg, M E

    1998-08-15

    Non-detergent sulfobetaines (NDSB) are a family of solubilizing and stabilizing agents for proteins. In a previous study [Goldberg, M. E., Expert-Bezancon, N., Vuillard, L. & Rabilloud, T. (1996) Folding & Design 1, 21-27] we showed that the amount of active protein recovered in in vitro folding experiments could be significantly increased by some NDSBS. In this work we investigated the mechanisms by which these molecules facilitate protein renaturation. Stopped-flow and manual-mixing fluorescence and enzyme activity measurements were used to compare the kinetics of protein folding in the presence and absence of N-phenyl-methyl-N,N-dimethylammonium-propane-sulfonate (NDSB 256). Hen lysozyme and the beta2 subunit of Escherichia coli tryptophan synthase were chosen as model systems since their folding pathways had been previously investigated in detail. It is shown that, massive aggregation of tryptophan synthase occurs within less than 2.5 s after dilution in the renaturation buffer, but can be prevented by NDSB 256; only very early folding phases (such as the formation of a loosely packed hydrophobic core able to bind 8-anilino-1-naphthalenesulphonic acid, and the initial burying of tryptophan 177) are significantly altered by NDSB 256; none of the later phases is affected. Furthermore, NDSB 256 did not significantly affect any of the kinetic phases observed during the refolding of denatured lysozyme retaining intact disulphide bonds. This shows that NDSB 256 only interferes with very early steps in the folding process and acts by limiting the abortive interactions that could lead to the formation of inactive aggregates.

  13. Large-scale generation of human iPSC-derived neural stem cells/early neural progenitor cells and their neuronal differentiation.

    PubMed

    D'Aiuto, Leonardo; Zhi, Yun; Kumar Das, Dhanjit; Wilcox, Madeleine R; Johnson, Jon W; McClain, Lora; MacDonald, Matthew L; Di Maio, Roberto; Schurdak, Mark E; Piazza, Paolo; Viggiano, Luigi; Sweet, Robert; Kinchington, Paul R; Bhattacharjee, Ayantika G; Yolken, Robert; Nimgaonka, Vishwajit L; Nimgaonkar, Vishwajit L

    2014-01-01

    Induced pluripotent stem cell (iPSC)-based technologies offer an unprecedented opportunity to perform high-throughput screening of novel drugs for neurological and neurodegenerative diseases. Such screenings require a robust and scalable method for generating large numbers of mature, differentiated neuronal cells. Currently available methods based on differentiation of embryoid bodies (EBs) or directed differentiation of adherent culture systems are either expensive or are not scalable. We developed a protocol for large-scale generation of neuronal stem cells (NSCs)/early neural progenitor cells (eNPCs) and their differentiation into neurons. Our scalable protocol allows robust and cost-effective generation of NSCs/eNPCs from iPSCs. Following culture in neurobasal medium supplemented with B27 and BDNF, NSCs/eNPCs differentiate predominantly into vesicular glutamate transporter 1 (VGLUT1) positive neurons. Targeted mass spectrometry analysis demonstrates that iPSC-derived neurons express ligand-gated channels and other synaptic proteins and whole-cell patch-clamp experiments indicate that these channels are functional. The robust and cost-effective differentiation protocol described here for large-scale generation of NSCs/eNPCs and their differentiation into neurons paves the way for automated high-throughput screening of drugs for neurological and neurodegenerative diseases.

  14. Gauss-Bonnet cosmology unifying late and early-time acceleration eras with intermediate eras

    NASA Astrophysics Data System (ADS)

    Oikonomou, V. K.

    2016-07-01

    In this paper we demonstrate that with vacuum F(G) gravity it is possible to describe the unification of late and early-time acceleration eras with the radiation and matter domination era. The Hubble rate of the unified evolution contains two mild singularities, so called Type IV singularities, and the evolution itself has some appealing features, such as the existence of a deceleration-acceleration transition at late times. We also address quantitatively a fundamental question related to modified gravity models description of cosmological evolution: Is it possible for all modified gravity descriptions of our Universe evolution, to produce a nearly scale invariant spectrum of primordial curvature perturbations? As we demonstrate, the answer for the F(G) description is no, since the resulting power spectrum is not scale invariant, in contrast to the F(R) description studied in the literature. Therefore, although the cosmological evolution can be realized in the context of vacuum F(G) gravity, the evolution is not compatible with the observational data, in contrast to the F(R) gravity description of the same cosmological evolution.

  15. Loss of Citron Kinase Affects a Subset of Progenitor Cells That Alters Late but Not Early Neurogenesis in the Developing Rat Retina

    PubMed Central

    Karunakaran, Devi Krishna Priya; Chhaya, Nisarg; Lemoine, Christopher; Congdon, Sean; Black, Amye; Kanadia, Rahul

    2015-01-01

    Purpose. To understand how loss of citron kinase (CitK) affects retinal progenitor cells (RPCs) in the developing rat retina. Methods. We compared knockout (KO) and wild-type (WT) retinae by immunohistochemistry. The TdT-mediated dUTP terminal nick-end labeling (TUNEL) assay was performed to determine cell death. Pulse-chase experiments using 5-ethynyl-2’-deoxyuridine (EdU) were carried out to interrogate RPC behavior and in turn neurogenesis. Results. Reverse transcription–polymerase chain reaction analysis showed that CitK was expressed at embryonic day (E)12 and was turned off at approximately postnatal day (P)4. Immunohistochemistry showed CitK being localized as puncta at the apical end of the outer neuroblastic layer (ONBL). Analyses during embryonic development showed that the KO retina was of comparable size to that of WT until E13. However, by E14, there was a reduction in the number of S-phase RPCs with a concomitant increase in TUNEL+ cells in the KO retina. Moreover, early neurogenesis, as reflected by retinal ganglion cell production, was not affected. Postnatal analysis of the retina showed that ONBL in the KO retina was reduced to half the size of that in WT and showed further degeneration. Immunohistochemistry revealed absence of Islet1+ bipolar cells at P2, which was further confirmed by EdU pulse-chase experiments. The CitK KO retinae underwent complete degeneration by P14. Conclusions. Our study showed that CitK is not required for a subset of RPCs before E14, but is necessary for RPC survival post E14. This in turn results in normal early embryonic neurogenesis, but severely compromised later embryonic and postnatal neurogenesis. PMID:25593024

  16. The effect of gender on early and intermediate results of endovascular aneurysm repair.

    PubMed

    Nordness, Paul J; Carter, Glen; Tonnessen, Britt; Charles Sternbergh, W; Money, Samuel R

    2003-11-01

    Results of endovascular aneurysm repair (EVAR) may be gender dependent. Between September 1997 and September 2001, 118 AneuRx aortic grafts were placed for aneurysmal disease. During this period, 17 females and 101 males were treated with this device. A prospective database was maintained and supplemented with retrospectively gathered information to evaluate early and mid-term end points. A total of 113 devices were deployed in 118 attempts. Length of procedure was greater for females (3.3 +/- 1.75 vs. 2.3 +/- 0.8 hr, p = 0.05) and they were more likely to have significant arterial dissections (12% vs. 1%, p = 0.05). The mortality rates at 1 month were 12% for females and 0% for males ( p = 0.02); the complication rates at 1 month were 41% for females and 15% for males ( p = 0.02). Although technical success was not significantly different between the sexes, assisted primary technical success (requiring endovascular assistance) and assisted secondary technical success (requiring open surgical assistance) were significantly different (71% vs. 96%, p = 0.003; and 76% vs. 98%, p = 0.004, respectively). Clinical success at 1 month was 59% for females and 84% for males ( p = 0.02). This difference was also significant when assessing 1-month assisted primary clinical success (59% vs. 90%, p = 0.003) and assisted secondary clinical success as well (71% vs. 96%, p = 0.003). Clinical success and assisted primary clinical success were not different at 6- or 12-month intervals, however, assisted secondary clinical successes differed at both time intervals (56% vs. 83%, p = 0.02; and 56% vs. 81%, p = 0.05, respectively). As-yet undetermined factors appear to predispose females to complications and technical difficulties in the short term. Endovascular and open procedures required to achieve ongoing clinical success in the following months appear to favor males to a greater degree than females.

  17. Enhancer and Transcription Factor Dynamics during Myeloid Differentiation Reveal an Early Differentiation Block in Cebpa null Progenitors.

    PubMed

    Pundhir, Sachin; Bratt Lauridsen, Felicia Kathrine; Schuster, Mikkel Bruhn; Jakobsen, Janus Schou; Ge, Ying; Schoof, Erwin Marten; Rapin, Nicolas; Waage, Johannes; Hasemann, Marie Sigurd; Porse, Bo Torben

    2018-05-29

    Transcription factors PU.1 and CEBPA are required for the proper coordination of enhancer activity during granulocytic-monocytic (GM) lineage differentiation to form myeloid cells. However, precisely how these factors control the chronology of enhancer establishment during differentiation is not known. Through integrated analyses of enhancer dynamics, transcription factor binding, and proximal gene expression during successive stages of murine GM-lineage differentiation, we unravel the distinct kinetics by which PU.1 and CEBPA coordinate GM enhancer activity. We find no evidence of a pioneering function of PU.1 during late GM-lineage differentiation. Instead, we delineate a set of enhancers that gain accessibility in a CEBPA-dependent manner, suggesting a pioneering function of CEBPA. Analyses of Cebpa null bone marrow demonstrate that CEBPA controls PU.1 levels and, unexpectedly, that the loss of CEBPA results in an early differentiation block. Taken together, our data provide insights into how PU.1 and CEBPA functionally interact to drive GM-lineage differentiation. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  18. The synergistic effects of saxagliptin and metformin on CD34+ endothelial progenitor cells in early type 2 diabetes patients: a randomized clinical trial.

    PubMed

    Dore, Fiona J; Domingues, Cleyton C; Ahmadi, Neeki; Kundu, Nabanita; Kropotova, Yana; Houston, Sara; Rouphael, Carol; Mammadova, Aytan; Witkin, Linda; Khiyami, Anamil; Amdur, Richard L; Sen, Sabyasachi

    2018-05-03

    Type 2 diabetes is associated with endothelial dysfunction leading to cardiovascular disease. CD34+ endothelial Progenitor Cells (EPCs) are responsible for endothelial repair and neo-angiogenesis and can be used as a cardiovascular disease risk biomarker. This study investigated whether the addition of saxagliptin, a DPP-IV inhibitor, to metformin, may reduce cardiovascular disease risk in addition to improving glycemic control in Type 2 diabetes patients. In 12 week, double-blind, randomized placebo-controlled trial, 42 subjects already taking metformin 1-2 grams/day were randomized to placebo or saxagliptin 5 mg. Subjects aged 40-70 years with diabetes for < 10 years, with no known cardiovascular disease, BMI 25-39.9, HbA1C 6-9% were included. We evaluated EPCs number, function, surface markers and gene expression, in addition to arterial stiffness, blood biochemistries, resting energy expenditure, and body composition parameters. A mixed model regression to examine saxagliptin vs placebo, accounting for within-subject autocorrelation, was done with SAS (p < 0.05). Although there was no significant increase in CD34+ cell number, CD31+ cells percentage increased. Saxagliptin increased migration (in response to SDF1α) with a trend of higher colony formation count. MNCs cytometry showed higher percentage of CXCR4 double positivity for both CD34 and CD31 positive cells, indicating a functional improvement. Gene expression analysis showed an upregulation in CD34+ cells for antioxidant SOD1 (p < 0.05) and a downregulation in CD34- cells for IL-6 (p < 0.01). For arterial stiffness, both augmentation index and systolic blood pressure measures went down in saxagliptin subjects (p < 0.05). Saxagliptin, in combination with metformin, can help improve endothelial dysfunction in early diabetes before macrovascular complications appear. Trial registration Trial is registered under clinicaltrials.gov, NCT02024477.

  19. Early accelerated senescence of circulating endothelial progenitor cells in premature coronary artery disease patients in a developing country - a case control study.

    PubMed

    Vemparala, Kranthi; Roy, Ambuj; Bahl, Vinay Kumar; Prabhakaran, Dorairaj; Nath, Neera; Sinha, Subrata; Nandi, Pradipta; Pandey, Ravindra Mohan; Reddy, Kolli Srinath; Manhapra, Ajay; Lakshmy, Ramakrishnan

    2013-11-19

    The decreased number and senescence of circulating endothelial progenitor cells (EPCs) are considered markers of vascular senescence associated with aging, atherosclerosis, and coronary artery disease (CAD) in elderly. In this study, we explore the role of vascular senescence in premature CAD (PCAD) in a developing country by comparing the numerical status and senescence of circulating EPCs in PCAD patients to controls. EPCs were measured by flow cytometry in 57 patients with angiographically documented CAD, and 57 controls without evidence of CAD, recruited from random patients ≤ 50 years of age at All India Institute of Medical Sciences. EPC senescence as determined by telomere length (EPC-TL) and telomerase activity (EPC-TA) was studied by real time polymerase chain reaction (q PCR) and PCR- ELISA respectively. The number of EPCs (0.18% Vs. 0.039% of total WBCs, p < 0.0001), and EPC-TL (3.83 Vs. 5.10 kb/genome, p = 0.009) were markedly lower in PCAD patients compared to controls. These differences persisted after adjustment for age, sex, BMI, smoking and medications. EPC-TA was reduced in PCAD patients, but was statistically significant only after adjustment for confounding factors (1.81 Vs. 2.20 IU/cell, unadjusted p = 0.057, adjusted p = 0.044). We observed an association between increased vascular cell senescence with PCAD in a sample of young patients from India. This suggests that early accelerated vascular cell senescence may play an important mechanistic role in CAD epidemic in developing countries like India where PCAD burden is markedly higher compared to developed countries.

  20. THE VERY EARLY LIGHT CURVE OF SN 2015F IN NGC 2442: A POSSIBLE DETECTION OF SHOCK-HEATED COOLING EMISSION AND CONSTRAINTS ON SN Ia PROGENITOR SYSTEM

    SciTech Connect

    Im, Myungshin; Choi, Changsu; Kim, Jae-Woo

    2015-11-15

    The main progenitor candidates of Type Ia supernovae (SNe Ia) are white dwarfs in binary systems where the companion star is another white dwarf (double degenerate (DD) system) or a less-evolved, non-degenerate star with R{sub *} ≳ 0.1 R{sub ⊙} (single degenerate system). However, no direct observational evidence exists to tell us which progenitor system is more common. Recent studies suggest that the light curve of a supernova shortly after its explosion can be used to set a limit on the progenitor size, R{sub *}. Here, we report high-cadence monitoring observations of SN 2015F, a normal SN Ia in themore » galaxy NGC 2442, starting about 84 days before the first light time. Using our daily cadence data, we capture the emergence of the radioactively powered light curve; more importantly, with >97.4% confidence, we detect possible dim precursor emission that appears roughly 1.5 days before the rise of the radioactively powered emission. The signal is consistent with theoretical expectations for a progenitor system involving a companion star with R{sub *} ≃ 0.1–1 R{sub ⊙} or a prompt explosion of a DD system, but is inconsistent with the typically invoked size of a white dwarf progenitor of R{sub *} ∼ 0.01 R{sub ⊙}. Upper limits on the precursor emission also constrain the progenitor size to be R{sub *} ≲ 0.1 R{sub ⊙} with a companion star size of R{sub *} ≲ 1.0 R{sub ⊙}, excluding a very large companion star in the progenitor system. Additionally, we find that the distance to SN 2015F is 23.9 ± 0.4 Mpc.« less

  1. Trepanation in South-Central Peru during the early late intermediate period (ca. AD 1000-1250).

    PubMed

    Kurin, Danielle S

    2013-12-01

    This study evaluates trepanations from five well-contextualized prehistoric sites in the south-central highlands of Andahuaylas, Peru. The emergence of trepanation in this region coincides with the collapse of the Wari Empire, ca. ad 1000. Thirty-two individuals from Andahuaylas, AMS radiocarbon dated to the early Late Intermediate Period (ca. ad 1000-1250), were found to have 45 total trepanations. Various surgical techniques were being employed concurrently throughout the region. Scraping trepanations evinced the highest survival rate; circular grooving, drilling and boring, and linear cutting were far less successful. Evidence of perioperative procedures like hair shaving, poultice application, and possible cranioplasty use aimed to ensure the survival of a trepanation recipient. Postmortem trepanations, also present in Andahuaylas, were likely executed on corpses as a means of better understanding cranial anatomy and improving techniques. Similarities in trepanation patterns throughout the region attest to common motivations to engage in surgery. Although moderate physical head trauma seems to be the impetus for intervention in many cases of trepanation, other motivations included physiological and possibly psychosomatic factors. Nevertheless, treatment was not for everyone. In Andahuaylas, trepanations were withheld from subadults, females, and those individuals who practiced cranial modification. Copyright © 2013 Wiley Periodicals, Inc.

  2. A rare case of os odontoideum from an Early Intermediate period tomb at the Huacas de Moche, Peru.

    PubMed

    Titelbaum, A R; Castillo, S Uceda

    2015-12-01

    Os odontoideum is an uncommon vertebral anomaly where there is a smoothly corticated ossicle independent from a shortened odontoid peg. An example of os odontoideum was observed in an Early Intermediate period skeleton excavated from the Huacas de Moche (Moche IV, AD 400-700), Peru. The affected individual is a middle adult male who presents additional minor developmental anomalies of the axial skeleton. This individual was interred with a middle adult female who also has developmental anomalies of the axial skeleton, including block cervical vertebra (Klippel-Feil). Os odontoideum is infrequently reported in the medical literature and there continues to be debate about whether it is acquired or congenital. Unlike clinical cases, archaeological cases present an opportunity to examine the entirety of the skeleton. In the present case, there does not appear to be macroscopic or radiographic evidence for a healed fracture, and since the individual has multiple minor axial developmental anomalies, a congenital etiology is plausible. This case is the first to be described from the archaeological context of South America and one of few paleopathological examples worldwide. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Extended main sequence turnoffs in intermediate-age star clusters: a correlation between turnoff width and early escape velocity

    SciTech Connect

    Goudfrooij, Paul; Kozhurina-Platais, Vera; Kalirai, Jason S.

    2014-12-10

    We present a color-magnitude diagram analysis of deep Hubble Space Telescope imaging of a mass-limited sample of 18 intermediate-age (1-2 Gyr old) star clusters in the Magellanic Clouds, including eight clusters for which new data were obtained. We find that all star clusters in our sample feature extended main-sequence turnoff (eMSTO) regions that are wider than can be accounted for by a simple stellar population (including unresolved binary stars). FWHM widths of the MSTOs indicate age spreads of 200-550 Myr. We evaluate the dynamical evolution of clusters with and without initial mass segregation. Our main results are (1) the fractionmore » of red clump (RC) stars in secondary RCs in eMSTO clusters scales with the fraction of MSTO stars having pseudo-ages of ≲1.35 Gyr; (2) the width of the pseudo-age distributions of eMSTO clusters is correlated with their central escape velocity v {sub esc}, both currently and at an age of 10 Myr. We find that these two results are unlikely to be reproduced by the effects of interactive binary stars or a range of stellar rotation velocities. We therefore argue that the eMSTO phenomenon is mainly caused by extended star formation within the clusters; and (3) we find that v {sub esc} ≥ 15 km s{sup –1} out to ages of at least 100 Myr for all clusters featuring eMSTOs, and v {sub esc} ≤ 12 km s{sup –1} at all ages for two lower-mass clusters in the same age range that do not show eMSTOs. We argue that eMSTOs only occur for clusters whose early escape velocities are higher than the wind velocities of stars that provide material from which second-generation stars can form. The threshold of 12-15 km s{sup –1} is consistent with wind velocities of intermediate-mass asymptotic giant branch stars and massive binary stars in the literature.« less

  4. Early Exposure to Intermediate-Frequency Magnetic Fields Alters Brain Biomarkers without Histopathological Changes in Adult Mice

    PubMed Central

    Win-Shwe, Tin-Tin; Ohtani, Shin; Ushiyama, Akira; Kunugita, Naoki

    2015-01-01

    Recently we have reported that intermediate-frequency magnetic field (IF-MF) exposure transiently altered the mRNA expression levels of memory function-related genes in the hippocampi of adult male mice. However, the effects of IF-MF exposure during brain development on neurological biomarkers have not yet been clarified. In the present study, we investigated the effect of IF-MF exposure during development on neurological and immunological markers in the mouse hippocampus in 3- and 7-week-old male mice. Pregnant C57BL/6J mice were exposed to IF-MF (21 kHz, 3.8 mT) for one hour per day from organogenesis period day 7 to 17. At adolescence, some IF-MF-exposed mice were further divided into exposure, recovery, and sham-exposure groups. The adolescent-exposure groups were exposed again to IF-MF from postnatal day 27 to 48. The expression of mRNA in the hippocampi was examined using a real-time RT-PCR method, and microglia activation was examined by immunohistochemical analysis. The expression levels of NR1 and NR2B as well as transcription factors (CaMKIV, CREB1), inflammatory mediators (COX2, IL-1 β,TNF-α), and the oxidative stress marker heme-oxygenase (HO)-1 were significantly increased in the IF-MF-exposed mice, compared with the control group, in the 7-week-old mice, but not in the 3-week-old mice. Microglia activation was not different between the control and other groups. This study provides the first evidence that early exposure to IF-MF reversibly affects the NMDA receptor, its related signaling pathways, and inflammatory mediators in the hippocampus of young adult mice; these changes are transient and recover after termination of exposure without histopathological changes. PMID:25913185

  5. Hospital at home for chronic obstructive pulmonary disease: an integrated hospital and community based generic intermediate care service for prevention and early discharge.

    PubMed

    Davison, A G; Monaghan, M; Brown, D; Eraut, C D; O'Brien, A; Paul, K; Townsend, J; Elston, C; Ward, L; Steeples, S; Cubitt, L

    2006-01-01

    Recent randomized controlled studies have reported success for hospital at home for prevention and early discharge of chronic obstructive pulmonary disease (COPD) patients using hospital based respiratory nurse specialists. This observational study reports results using an integrated hospital and community based generic intermediate care service. The length of care, readmission within 60 days and death within 60 days in the early discharge (9.37 days, 21.1%, 7%) and the prevention of admission (five to six days, 34.1%, 3.8%) are similar to previous studies. We suggest that this generic community model of service may allow hospital at home services for COPD to be introduced in more areas.

  6. Intermediate treatments

    Treesearch

    John R. Jones; Wayne D. Shepperd

    1985-01-01

    Intermediate treatments are those applied after a new stand is successfully established and before the final harvest. These include not only intermediate cuttings - primarily thinning - but also fertilization, irrigation, and protection of the stand from damaging agents.

  7. Impaired Endothelial Repair Capacity of Early Endothelial Progenitor Cells in Hypertensive Patients With Primary Hyperaldosteronemia: Role of 5,6,7,8-Tetrahydrobiopterin Oxidation and Endothelial Nitric Oxide Synthase Uncoupling.

    PubMed

    Chen, Long; Ding, Mei-Lin; Wu, Fang; He, Wen; Li, Jin; Zhang, Xiao-Yu; Xie, Wen-Li; Duan, Sheng-Zhong; Xia, Wen-Hao; Tao, Jun

    2016-02-01

    Although hyperaldosteronemia exerts detrimental impacts on vascular endothelium in addition to elevating blood pressure, the effects and molecular mechanisms of hyperaldosteronemia on early endothelial progenitor cell (EPC)-mediated endothelial repair after arterial damage are yet to be determined. The aim of this study was to investigate the endothelial repair capacity of early EPCs from hypertensive patients with primary hyperaldosteronemia (PHA). In vivo endothelial repair capacity of early EPCs from PHAs (n=20), age- and blood pressure-matched essential hypertension patients (n=20), and age-matched healthy subjects (n=20) was evaluated by transplantation into a nude mouse carotid endothelial denudation model. Endothelial function was evaluated by flow-mediated dilation of brachial artery in human subjects. In vivo endothelial repair capacity of early EPCs and flow-mediated dilation were impaired both in PHAs and in essential hypertension patients when compared with age-matched healthy subjects; however, the early EPC in vivo endothelial repair capacity and flow-mediated dilation of PHAs were impaired more severely than essential hypertension patients. Oral spironolactone improved early EPC in vivo endothelial repair capacity and flow-mediated dilation of PHAs. Increased oxidative stress, oxidative 5,6,7,8-tetrahydrobiopterin degradation, endothelial nitric oxide synthase uncoupling and decreased nitric oxide production were found in early EPCs from PHAs. Nicotinamide adenine dinucleotide phosphate oxidase subunit p47(phox) knockdown or 5,6,7,8-tetrahydrobiopterin supplementation attenuated endothelial nitric oxide synthase uncoupling and enhanced in vivo endothelial repair capacity of early EPCs from PHAs. In conclusion, PHAs exhibited more impaired endothelial repair capacity of early EPCs than did essential hypertension patients independent of blood pressure, which was associated with mineralocorticoid receptor-dependent oxidative stress and subsequently 5

  8. Early versus delayed invasive strategy for intermediate- and high-risk acute coronary syndromes managed without P2Y12 receptor inhibitor pretreatment: Design and rationale of the EARLY randomized trial.

    PubMed

    Lemesle, Gilles; Laine, Marc; Pankert, Mathieu; Puymirat, Etienne; Cuisset, Thomas; Boueri, Ziad; Maillard, Luc; Armero, Sébastien; Cayla, Guillaume; Bali, Laurent; Motreff, Pascal; Peyre, Jean-Pascal; Paganelli, Franck; Kerbaul, François; Roch, Antoine; Michelet, Pierre; Baumstarck, Karine; Bonello, Laurent

    2018-01-01

    According to recent literature, pretreatment with a P2Y 12 ADP receptor antagonist before coronary angiography appears no longer suitable in non-ST-segment elevation acute coronary syndrome (NSTE-ACS) due to an unfavorable risk-benefit ratio. Optimal delay of the invasive strategy in this specific context is unknown. We hypothesize that without P2Y 12 ADP receptor antagonist pretreatment, a very early invasive strategy may be beneficial. The EARLY trial (Early or Delayed Revascularization for Intermediate- and High-Risk Non-ST-Segment Elevation Acute Coronary Syndromes?) is a prospective, multicenter, randomized, controlled, open-label, 2-parallel-group study that plans to enroll 740 patients. Patients are eligible if the diagnosis of intermediate- or high-risk NSTE-ACS is made and an invasive strategy intended. Patients are randomized in a 1:1 ratio. In the control group, a delayed strategy is adopted, with the coronary angiography taking place between 12 and 72 hours after randomization. In the experimental group, a very early invasive strategy is performed within 2 hours. A loading dose of a P2Y 12 ADP receptor antagonist is given at the time of intervention in both groups. Recruitment began in September 2016 (n = 558 patients as of October 2017). The primary endpoint is the composite of cardiovascular death and recurrent ischemic events at 1 month. The EARLY trial aims to demonstrate the superiority of a very early invasive strategy compared with a delayed strategy in intermediate- and high-risk NSTE-ACS patients managed without P2Y 12 ADP receptor antagonist pretreatment. © 2018 Wiley Periodicals, Inc.

  9. Association of 70-Gene Signature Assay Findings With Physicians' Treatment Guidance for Patients With Early Breast Cancer Classified as Intermediate Risk by the 21-Gene Assay.

    PubMed

    Tsai, Michaela; Lo, Shelly; Audeh, William; Qamar, Rubina; Budway, Raye; Levine, Ellis; Whitworth, Pat; Mavromatis, Blanche; Zon, Robin; Oldham, Dwight; Untch, Sarah; Treece, Tina; Blumencranz, Lisa; Soliman, Hatem

    2018-01-11

    Among patients who undergo the 21-gene assay (21-GA), 39% to 67% receive an intermediate risk result and may receive ambiguous treatment guidance. The 70-gene signature assay (70-GS) may be associated with physicians' treatment decisions in this population with early breast cancer. To determine whether 70-GS findings are associated with physicians' decisions about adjuvant treatment and confidence in their recommendations and to evaluate the dichotomous (high- vs low-risk) and continuous distribution of 70-GS indices among this group of patients with intermediate risk. The Prospective Study of MammaPrint in Breast Cancer Patients With an Intermediate Recurrence Score (PROMIS trial) was an impact study conducted from May 20, 2012, through December 31, 2015, that enrolled 840 patients with early-stage breast cancer and a 21-gene assay recurrence score of 18 to 30. Patients were treated in 58 US institutions. The 70-GS result was given to physicians before adjuvant treatment. Change in physician treatment decision before vs after receiving the 70-GS result. With a treatment change of greater than 20%, the odds ratio (OR) was applied. Among the 840 patients who underwent 70-GS classification (mean age, 59 years; range, 27-93 years), 374 (44.5%) had a low-risk and 466 (55.5%) had a high-risk result. The distribution of 70-GS indices did not correlate with recurrence score within the 21-GA intermediate range, with 70-GS low- and high-risk patients observed at every recurrence score. A significant change in adjuvant treatment was associated with receiving the 70-GS classifications with an OR of 0.64 (95% CI, 0.50-0.82; McNemar test, P < .001) for all patients. Among the low-risk patients, 108 of 374 (28.9%) had chemotherapy removed from their treatment recommendation; among the high-risk patients, 171 of 466 (36.7%) had chemotherapy added. Results of the 70-GS were associated with the physician's adjuvant treatment recommendation; 409 high-risk patients (87.8%) were

  10. Evaluation of oral keratinocyte progenitor and T-lymphocite cells response during early healing after augmentation of keratinized gingiva with a 3D collagen matrix - a pilot study.

    PubMed

    Rusu, Darian; Calenic, Bogdan; Greabu, Maria; Kralev, Alexander; Boariu, Marius; Bojin, Florina; Anghel, Simona; Paunescu, Virgil; Vela, Octavia; Calniceanu, Horia; Stratul, Stefan-Ioan

    2016-07-07

    The aim of the present study is to analyze the behavior of selected populations of oral keratinocytes and T-lymphocytes, responsible for re-constructing and maintaining the oral epithelial tissue architecture, following augmentation of the keratinized oral mucosa using a 3D-collagen matrix. Different groups of oral keratinocytes were isolated from biopsies harvested from 3 patients before the surgical procedure, as well as 7 and 14 days after the augmentation procedure. T-lymphocytes were isolated from peripheral blood at same timepoints. Keratinocytes were characterized for stem and differentiation markers, such as p63, cytokeratin 10 and 14, and in vitro parameters, such as cell viability, cell size and colony-forming efficiency. T-lymphocytes were analyzed for viability and the expression of various cluster of differentiation markers. The methods included magnetic separation of cell populations, immunofluorescence, flow cytometry, and histology of oral biopsies. Both at 7 and 14 days, the majority of cells that repopulate the matrix were actively proliferating/progenitor oral keratinocytes with the phenotype integrin alfa6beta4 + CD71+. These cells display in vitro characteristics similar to the progenitor cells analyzed before the matrix placement. T-lymphocytes expressed CD8 and CD69 markers, while CD25 was absent. The study shows that two weeks after the collagen membrane placement, the healing process appeared to be histologically complete, with no abnormal immune response induced by the matrix, however, with a higher than usual content of active proliferating cells, the majority of keratinocytes being characterized as transit amplifying cells.

  11. Pediatric Early Warning Systems aid in triage to intermediate versus intensive care for pediatric oncology patients in resource-limited hospitals.

    PubMed

    Agulnik, Asya; Nadkarni, Anisha; Mora Robles, Lupe Nataly; Soberanis Vasquez, Dora Judith; Mack, Ricardo; Antillon-Klussmann, Federico; Rodriguez-Galindo, Carlos

    2018-04-10

    Pediatric oncology patients hospitalized in resource-limited settings are at high risk for clinical deterioration resulting in mortality. Intermediate care units (IMCUs) provide a cost-effective alternative to pediatric intensive care units (PICUs). Inappropriate IMCU triage, however, can lead to poor outcomes and suboptimal resource utilization. In this study, we sought to characterize patients with clinical deterioration requiring unplanned transfer to the IMCU in a resource-limited pediatric oncology hospital. Patients requiring subsequent early PICU transfer had longer PICU length of stay. PEWS results prior to IMCU transfer were higher in patients requiring early PICU transfer, suggesting PEWS can aid in triage between IMCU and PICU care. © 2018 Wiley Periodicals, Inc.

  12. PDL Progenitor-Mediated PDL Recovery Contributes to Orthodontic Relapse.

    PubMed

    Feng, L; Yang, R; Liu, D; Wang, X; Song, Y; Cao, H; He, D; Gan, Y; Kou, X; Zhou, Y

    2016-08-01

    Periodontal ligament (PDL) is subjected to mechanical force during physiologic activities. PDL stem /: progenitor cells are the main mesenchymal stem cells in PDL. However, how PDL progenitors participate in PDL homeostasis upon and after mechanical force is largely unknown. In this study, force-triggered orthodontic tooth movement and the following relapse were used as models to demonstrate the response of PDL progenitors and their role in PDL remodeling upon and after mechanical force. Upon orthodontic force, PDL collagen on the compression side significantly degraded, showing a broken and disorganized pattern. After force withdrawal, the degraded PDL collagen recovered during the early stage of relapse. Correspondingly, increased CD90(+) PDL progenitors with suppressed expression of type I collagen (Col-I) were observed upon orthodontic force, whereas these cells accumulated at the degradation regions and regained Col-I expression after force withdrawal during early relapse. Our results further showed that compressive force altered cell morphology and repressed collagen expression in cultured PDL progenitors, which both recovered after force withdrawal. Force withdrawal-induced recovery of collagen expression in cultured PDL progenitors could be regulated by transforming growth factor-β (TGF-β), a key molecule for tissue homeostasis and extracellular matrix remodeling. More interesting, inhibiting the regained Col-I expression in CD90(+) PDL progenitors by blocking TGF-β interrupted PDL collagen recovery and partially inhibited the early relapse. These data suggest that PDL progenitors can respond to mechanical force and may process intrinsic stability to recover to original status after force withdrawal. PDL progenitors with intrinsic stability are required for PDL recovery and consequently contribute to early orthodontic relapse, which can be regulated by TGF-β signaling. © International & American Associations for Dental Research 2016.

  13. Role of distal arginine in early sensing intermediates in the heme domain of the oxygen sensor FixL.

    PubMed

    Jasaitis, Audrius; Hola, Klara; Bouzhir-Sima, Latifa; Lambry, Jean-Christophe; Balland, Veronique; Vos, Marten H; Liebl, Ursula

    2006-05-16

    FixL is a bacterial heme-based oxygen sensor, in which release of oxygen from the sensing PAS domain leads to activation of an associated kinase domain. Static structural studies have suggested an important role of the conserved residue arginine 220 in signal transmission at the level of the heme domain. To assess the role of this residue in the dynamics and properties of the initial intermediates in ligand release, we have investigated the effects of R220X (X = I, Q, E, H, or A) mutations in the FixLH heme domain on the dynamics and spectral properties of the heme upon photolysis of O(2), NO, and CO using femtosecond transient absorption spectroscopy. Comparison of transient spectra for CO and NO dissociation with steady-state spectra indicated less strain on the heme in the ligand dissociation species for all mutants compared to the wild type (WT). For CO and NO, the kinetics were similar to those of the wild type, with the exception of (1) a relatively low yield of picosecond NO rebinding to R220A, presumably related to the increase in the free volume of the heme pocket, and (2) substantial pH-dependent picosecond to nanosecond rebinding of CO to R220H, related to formation of a hydrogen bond between CO and histidine 220. Upon excitation of the complex bound with the physiological sensor ligand O(2), a 5-8 ps decay phase and a nondecaying (>4 ns) phase were observed for WT and all mutants. The strong distortion of the spectrum associated with the decay phase in WT is substantially diminished in all mutant proteins, indicating an R220-induced role of the heme in the primary intermediate in signal transmission. Furthermore, the yield of dissociated oxygen after this phase ( approximately 10% in WT) is increased in all mutants, up to almost unity in R220A, indicating a key role of R220 in caging the oxygen near the heme through hydrogen bonding. Molecular dynamics simulations corroborate these findings and suggest motions of O(2) and arginine 220 away from the heme

  14. Prognostic Value of Transthoracic Doppler Echocardiography Coronary Flow Velocity Reserve in Patients with Nonculprit Stenosis of Intermediate Severity Early after Primary Percutaneous Coronary Intervention.

    PubMed

    Tesic, Milorad; Djordjevic-Dikic, Ana; Giga, Vojislav; Stepanovic, Jelena; Dobric, Milan; Jovanovic, Ivana; Petrovic, Marija; Mehmedbegovic, Zlatko; Milasinovic, Dejan; Dedovic, Vladimir; Zivkovic, Milorad; Juricic, Stefan; Orlic, Dejan; Stojkovic, Sinisa; Vukcevic, Vladan; Stankovic, Goran; Nedeljkovic, Milan; Ostojic, Miodrag; Beleslin, Branko

    2018-04-03

    Treatment of nonculprit coronary stenosis during primary percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction may be beneficial, but the mode and timing of the intervention are still controversial. The aim of this study was to examine the significance and prognostic value of preserved coronary flow velocity reserve (CFVR) in patients with nonculprit intermediate stenosis early after primary percutaneous coronary intervention. Two hundred thirty patients with remaining intermediate (50%-70%) stenosis of non-infarct-related arteries, in whom CFVR was performed within 7 days after primary percutaneous coronary intervention, were prospectively enrolled. Twenty patients with reduced CFVR and positive results on stress echocardiography or impaired fractional flow reserve underwent revascularization and were not included in further analysis. The final study population of 210 patients (mean age, 58 ± 10 years; 162 men) was divided into two groups on the basis of CFVR: group 1, CFVR > 2 (n = 174), and group 2, CFVR ≤ 2 (n = 36). Cardiac death, nonfatal myocardial infarction, and revascularization of the evaluated vessel were considered adverse events. Mean follow-up duration was 47 ± 16 months. Mean CFVR for the whole group was 2.36 ± 0.40. There were six adverse events (3.4%) related to the nonculprit coronary artery in group 1, including one cardiac death, one ST-segment elevation myocardial infarction, and four revascularizations. In group 2, there were 30 adverse events (83.3%, P < .001 vs group 1), including two cardiac deaths, two ST-segment elevation myocardial infarctions, and 26 revascularizations. In patients with CFVR > 2 of the intermediate nonculprit coronary lesion, deferral of revascularization is safe and associated with excellent long-term clinical outcomes. Copyright © 2018 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

  15. SOX2 expression levels distinguish between neural progenitor populations of the developing dorsal telencephalon.

    PubMed

    Hutton, Scott R; Pevny, Larysa H

    2011-04-01

    The HMG-Box transcription factor SOX2 is expressed in neural progenitor populations throughout the developing and adult central nervous system and is necessary to maintain their progenitor identity. However, it is unclear whether SOX2 levels are uniformly expressed across all neural progenitor populations. In the developing dorsal telencephalon, two distinct populations of neural progenitors, radial glia and intermediate progenitor cells, are responsible for generating a majority of excitatory neurons found in the adult neocortex. Here we demonstrate, using both cellular and molecular analyses, that SOX2 is differentially expressed between radial glial and intermediate progenitor populations. Moreover, utilizing a SOX2(EGFP) mouse line, we show that this differential expression can be used to prospectively isolate distinct, viable populations of radial glia and intermediate cells for in vitro analysis. Given the limited repertoire of cell-surface markers currently available for neural progenitor cells, this provides an invaluable tool for prospectively identifying and isolating distinct classes of neural progenitor cells from the central nervous system. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. TOX3 regulates neural progenitor identity.

    PubMed

    Sahu, Sanjeeb Kumar; Fritz, Alina; Tiwari, Neha; Kovacs, Zsuzsa; Pouya, Alireza; Wüllner, Verena; Bora, Pablo; Schacht, Teresa; Baumgart, Jan; Peron, Sophie; Berninger, Benedikt; Tiwari, Vijay K; Methner, Axel

    2016-07-01

    The human genomic locus for the transcription factor TOX3 has been implicated in susceptibility to restless legs syndrome and breast cancer in genome-wide association studies, but the physiological role of TOX3 remains largely unknown. We found Tox3 to be predominantly expressed in the developing mouse brain with a peak at embryonic day E14 where it co-localizes with the neural stem and progenitor markers Nestin and Sox2 in radial glia of the ventricular zone and intermediate progenitors of the subventricular zone. Tox3 is also expressed in neural progenitor cells obtained from the ganglionic eminence of E15 mice that express Nestin, and it specifically binds the Nestin promoter in chromatin immunoprecipitation assays. In line with this, over-expression of Tox3 increased Nestin promoter activity, which was cooperatively enhanced by treatment with the stem cell self-renewal promoting Notch ligand Jagged and repressed by pharmacological inhibition of Notch signaling. Knockdown of Tox3 in the subventricular zone of E12.5 mouse embryos by in utero electroporation of Tox3 shRNA revealed a reduced Nestin expression and decreased proliferation at E14 and a reduced migration to the cortical plate in E16 embryos in electroporated cells. Together, these results argue for a role of Tox3 in the development of the nervous system. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Delayed Rectifier and A-Type Potassium Channels Associated with Kv 2.1 and Kv 4.3 Expression in Embryonic Rat Neural Progenitor Cells

    PubMed Central

    Smith, Dean O.; Rosenheimer, Julie L.; Kalil, Ronald E.

    2008-01-01

    Background Because of the importance of voltage-activated K+ channels during embryonic development and in cell proliferation, we present here the first description of these channels in E15 rat embryonic neural progenitor cells derived from the subventricular zone (SVZ). Activation, inactivation, and single-channel conductance properties of recorded progenitor cells were compared with those obtained by others when these Kv gene products were expressed in oocytes. Methodology/Principal Findings Neural progenitor cells derived from the subventricular zone of E15 embryonic rats were cultured under conditions that did not promote differentiation. Immunocytochemical and Western blot assays for nestin expression indicated that almost all of the cells available for recording expressed this intermediate filament protein, which is generally accepted as a marker for uncommitted embryonic neural progenitor cells. However, a very small numbers of the cells expressed GFAP, a marker for astrocytes, O4, a marker for immature oligodendrocytes, and βIII-tubulin, a marker for neurons. Using immunocytochemistry and Western blots, we detected consistently the expression of Kv2.1, and 4.3. In whole-cell mode, we recorded two outward currents, a delayed rectifier and an A-type current. Conclusions/Significance We conclude that Kv2.1, and 4.3 are expressed in E15 SVZ neural progenitor cells, and we propose that they may be associated with the delayed-rectifier and the A-type currents, respectively, that we recorded. These results demonstrate the early expression of delayed rectifier and A-type K+ currents and channels in embryonic neural progenitor cells prior to the differentiation of these cells. PMID:18270591

  18. Delayed rectifier and A-type potassium channels associated with Kv 2.1 and Kv 4.3 expression in embryonic rat neural progenitor cells.

    PubMed

    Smith, Dean O; Rosenheimer, Julie L; Kalil, Ronald E

    2008-02-13

    Because of the importance of voltage-activated K(+) channels during embryonic development and in cell proliferation, we present here the first description of these channels in E15 rat embryonic neural progenitor cells derived from the subventricular zone (SVZ). Activation, inactivation, and single-channel conductance properties of recorded progenitor cells were compared with those obtained by others when these Kv gene products were expressed in oocytes. Neural progenitor cells derived from the subventricular zone of E15 embryonic rats were cultured under conditions that did not promote differentiation. Immunocytochemical and Western blot assays for nestin expression indicated that almost all of the cells available for recording expressed this intermediate filament protein, which is generally accepted as a marker for uncommitted embryonic neural progenitor cells. However, a very small numbers of the cells expressed GFAP, a marker for astrocytes, O4, a marker for immature oligodendrocytes, and betaIII-tubulin, a marker for neurons. Using immunocytochemistry and Western blots, we detected consistently the expression of Kv2.1, and 4.3. In whole-cell mode, we recorded two outward currents, a delayed rectifier and an A-type current. We conclude that Kv2.1, and 4.3 are expressed in E15 SVZ neural progenitor cells, and we propose that they may be associated with the delayed-rectifier and the A-type currents, respectively, that we recorded. These results demonstrate the early expression of delayed rectifier and A-type K(+) currents and channels in embryonic neural progenitor cells prior to the differentiation of these cells.

  19. A Walk through TRIDEC's intermediate Tsunami Early Warning System for the Turkish and Portuguese NEAMWave12 exercise tsunami scenarios

    NASA Astrophysics Data System (ADS)

    Hammitzsch, Martin; Lendholt, Matthias; Reißland, Sven; Schulz, Jana

    2013-04-01

    the ICG/NEAMTWS NEAMWave12 exercise for the Turkish and Portuguese tsunami exercise scenarios. Impressions gained with the standards compliant TRIDEC system during the exercise will be reported. The system version presented is based on event-driven architecture (EDA) and service-oriented architecture (SOA) concepts and is making use of relevant standards of the Open Geospatial Consortium (OGC), the World Wide Web Consortium (W3C) and the Organization for the Advancement of Structured Information Standards (OASIS). In this way the system continuously gathers, processes and displays events and data coming from open sensor platforms to enable operators to quickly decide whether an early warning is necessary and to send personalized warning messages to the authorities and the population at large through a wide range of communication channels. The system integrates OGC Sensor Web Enablement (SWE) compliant sensor systems for the rapid detection of hazardous events, like earthquakes, sea level anomalies, ocean floor occurrences, and ground displacements. Using OGC Web Map Service (WMS) and Web Feature Service (WFS) spatial data are utilized to depict the situation picture. The integration of a simulation system to identify affected areas is considered using the OGC Web Processing Service (WPS). Warning messages are compiled and transmitted in the OASIS Common Alerting Protocol (CAP) together with addressing information defined via the OASIS Emergency Data Exchange Language - Distribution Element (EDXL-DE). This demonstration is linked with the talk 'Experiences with TRIDEC's Crisis Management Demonstrator in the Turkish NEAMWave12 exercise tsunami scenario' (EGU2013-2833) given in the session "Architecture of Future Tsunami Warning Systems" (NH5.6).

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

    PubMed

    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.

  1. Hematopoietic progenitor migration to the adult thymus

    PubMed Central

    Zlotoff, Daniel A.; Bhandoola, Avinash

    2010-01-01

    While most hematopoietic lineages develop in the bone marrow (BM), T cells uniquely complete their development in the specialized environment of the thymus. Hematopoietic stem cells with long-term self-renewal capacity are not present in the thymus. As a result, continuous T cell development requires that BM-derived progenitors be imported into the thymus throughout adult life. The process of thymic homing begins with the mobilization of progenitors out of the bone marrow, continues with their circulation in the bloodstream, and concludes with their settling in the thymus. This review will discuss each of these steps as they occur in the unirradiated and post-irradiation scenarios, focusing on the molecular mechanisms of regulation. Improved knowledge about these early steps in T cell generation may accelerate the development of new therapeutic options in patients with impaired T cell number or function. PMID:21251013

  2. Earmuff restricts progenitor cell potential by attenuating the competence to respond to self-renewal factors.

    PubMed

    Janssens, Derek H; Komori, Hideyuki; Grbac, Daniel; Chen, Keng; Koe, Chwee Tat; Wang, Hongyan; Lee, Cheng-Yu

    2014-03-01

    Despite expressing stem cell self-renewal factors, intermediate progenitor cells possess restricted developmental potential, which allows them to give rise exclusively to differentiated progeny rather than stem cell progeny. Failure to restrict the developmental potential can allow intermediate progenitor cells to revert into aberrant stem cells that might contribute to tumorigenesis. Insight into stable restriction of the developmental potential in intermediate progenitor cells could improve our understanding of the development and growth of tumors, but the mechanisms involved remain largely unknown. Intermediate neural progenitors (INPs), generated by type II neural stem cells (neuroblasts) in fly larval brains, provide an in vivo model for investigating the mechanisms that stably restrict the developmental potential of intermediate progenitor cells. Here, we report that the transcriptional repressor protein Earmuff (Erm) functions temporally after Brain tumor (Brat) and Numb to restrict the developmental potential of uncommitted (immature) INPs. Consistently, endogenous Erm is detected in immature INPs but undetectable in INPs. Erm-dependent restriction of the developmental potential in immature INPs leads to attenuated competence to respond to all known neuroblast self-renewal factors in INPs. We also identified that the BAP chromatin-remodeling complex probably functions cooperatively with Erm to restrict the developmental potential of immature INPs. Together, these data led us to conclude that the Erm-BAP-dependent mechanism stably restricts the developmental potential of immature INPs by attenuating their genomic responses to stem cell self-renewal factors. We propose that restriction of developmental potential by the Erm-BAP-dependent mechanism functionally distinguishes intermediate progenitor cells from stem cells, ensuring the generation of differentiated cells and preventing the formation of progenitor cell-derived tumor-initiating stem cells.

  3. The young and bright Type Ia supernova ASASSN-14lp: Discovery, early-time observations, first-light time, distance to NGC 4666, and progenitor constraints

    DOE PAGES

    Shappee, B. J.; Piro, A. L.; Holoien, T. W. -S.; ...

    2016-07-27

    On 2014 December 9.61, the All-sky Automated Survey for SuperNovae (ASAS-SN or "Assassin") discovered ASASSN-14lp just ~2 days after first light using a global array of 14 cm diameter telescopes. ASASSN-14lp went on to become a bright supernova (V = 11.94 mag), second only to SN 2014J for the year. We present prediscovery photometry (with a detection less than a day after first light) and ultraviolet through near-infrared photometric and spectroscopic data covering the rise and fall of ASASSN-14lp for more than 100 days. We find that ASASSN-14lp had a broad light curve (more » $${\\rm{\\Delta }}{m}_{15}(B)=0.80\\pm 0.05$$), a B-band maximum at 2457015.82 ± 0.03, a rise time of $${16.94}_{-0.10}^{+0.11}$$ days, and moderate host-galaxy extinction ($$E{(B-V)}_{\\mathrm{host}}=0.33\\pm 0.06$$). Using ASASSN-14lp, we derive a distance modulus for NGC 4666 of $$\\mu =30.8\\pm 0.2$$, corresponding to a distance of 14.7 ± 1.5 Mpc. However, adding ASASSN-14lp to the calibrating sample of Type Ia supernovae still requires an independent distance to the host galaxy. Lastly, using our early-time photometric and spectroscopic observations, we rule out red giant secondaries and, assuming a favorable viewing angle and explosion time, any nondegenerate companion larger than 0.34 $${R}_{\\odot }$$.« less

  4. Development of the expressed Ig CDR-H3 repertoire is marked by focusing of constraints in length, amino acid use, and charge that are first established in early B cell progenitors.

    PubMed

    Ivanov, Ivaylo I; Schelonka, Robert L; Zhuang, Yingxin; Gartland, G Larry; Zemlin, Michael; Schroeder, Harry W

    2005-06-15

    To gain insight into the mechanisms that regulate the development of the H chain CDR3 (CDR-H3), we used the scheme of Hardy to sort mouse bone marrow B lineage cells into progenitor, immature, and mature B cell fractions, and then performed sequence analysis on V(H)7183-containing Cmu transcripts. The essential architecture of the CDR-H3 repertoire observed in the mature B cell fraction F was already established in the early pre-B cell fraction C. These architectural features include V(H) gene segment use preference, D(H) family usage, J(H) rank order, predicted structures of the CDR-H3 base and loop, and the amino acid composition and average hydrophobicity of the CDR-H3 loop. With development, the repertoire was focused by eliminating outliers to what appears to be a preferred repertoire in terms of length, amino acid composition, and average hydrophobicity. Unlike humans, the average length of CDR-H3 increased during development. The majority of this increase came from enhanced preservation of J(H) sequence. This was associated with an increase in the prevalence of tyrosine. With an accompanying increase in glycine, a shift in hydrophobicity was observed in the CDR-H3 loop from near neutral in fraction C (-0.08 +/- 0.03) to mild hydrophilic in fraction F (-0.17 +/- 0.02). Fundamental constraints on the sequence and structure of CDR-H3 are thus established before surface IgM expression.

  5. Role of C/EBPβ-LAP and C/EBPβ-LIP in early adipogenic differentiation of human white adipose-derived progenitors and at later stages in immature adipocytes.

    PubMed

    Lechner, Stefan; Mitterberger, Maria C; Mattesich, Monika; Zwerschke, Werner

    2013-01-01

    We investigated the role of the major isoforms of CCAAT enhancer binding protein β (C/EBPβ), C/EBPβ-LAP and C/EBPβ-LIP, in adipogenesis of human white adipose-derived stromal/progenitor cells (ASC). C/EBPβ gene expression was transiently induced early in adipogenesis. At later stages, in immature adipocytes, the C/EBPβ mRNA and protein levels declined. The C/EBPβ-LIP protein steady-state level decreased considerably stronger than the C/EBPβ-LAP level and the C/EBPβ-LIP half-life was significantly shorter than the C/EBPβ-LAP half-life. The turn-over of both C/EBPβ-isoforms was regulated by ubiquitin/proteasome-dependent degradation. These data suggest that the protein stability of the C/EBPβ-isoforms is differentially regulated in the course of adipogenesis and in immature adipocytes. Constitutive overexpression of C/EBPβ-LIP had antiadipogenic activity in human ASC. C/EBPβ-LAP, which promotes adipogenesis in mouse 3T3-L1 preadipocytes by directly activating expression of the adipogenic keyregulator PPARγ2, induced the expression of PPARγ2 and of the adipocyte differentiation gene product FABP4 in confluent ASC in the absence of adipogenic hormones. At later stages after hormone cocktail-induced adipogenesis, in immature adipocytes, constitutive overexpression of C/EBPβ-LAP led to reduced expression of PPARγ2 and FABP4, C/EBPα expression was downregulated and the expression of the adipocyte differentiation gene products adiponectin and leptin was impaired. These findings suggest that constitutive overexpression of C/EBPβ-LAP induces adipogenesis in human ASC and negatively regulates the expression of adipogenic regulators and certain adipocyte differentiation gene products in immature adipocytes. We conclude the regulation of both C/EBPβ gene expression and C/EBPβ-LIP and C/EBPβ-LAP protein turn-over plays an important role for the expression of adipogenic regulators and/or adipocyte differentiation genes in early adipogenic differentiation of

  6. Retinoid signaling in progenitors controls specification and regeneration of the urothelium.

    PubMed

    Gandhi, Devangini; Molotkov, Andrei; Batourina, Ekatherina; Schneider, Kerry; Dan, Hanbin; Reiley, Maia; Laufer, Ed; Metzger, Daniel; Liang, Fengxia; Liao, Yi; Sun, Tung-Tien; Aronow, Bruce; Rosen, Roni; Mauney, Josh; Adam, Rosalyn; Rosselot, Carolina; Van Batavia, Jason; McMahon, Andrew; McMahon, Jill; Guo, Jin-Jin; Mendelsohn, Cathy

    2013-09-16

    The urothelium is a multilayered epithelium that serves as a barrier between the urinary tract and blood, preventing the exchange of water and toxic substances. It consists of superficial cells specialized for synthesis and transport of uroplakins that assemble into a tough apical plaque, one or more layers of intermediate cells, and keratin 5-expressing basal cells (K5-BCs), which are considered to be progenitors in the urothelium and other specialized epithelia. Fate mapping, however, reveals that intermediate cells rather than K5-BCs are progenitors in the adult regenerating urothelium, that P cells, a transient population, are progenitors in the embryo, and that retinoids are critical in P cells and intermediate cells, respectively, for their specification during development and regeneration. These observations have important implications for tissue engineering and repair and, ultimately, may lead to treatments that prevent loss of the urothelial barrier, a major cause of voiding dysfunction and bladder pain syndrome. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. HIV-1 infection depletes human CD34+CD38- hematopoietic progenitor cells via pDC-dependent mechanisms.

    PubMed

    Li, Guangming; Zhao, Juanjuan; Cheng, Liang; Jiang, Qi; Kan, Sheng; Qin, Enqiang; Tu, Bo; Zhang, Xin; Zhang, Liguo; Su, Lishan; Zhang, Zheng

    2017-07-01

    Chronic human immunodeficiency virus-1 (HIV-1) infection in patients leads to multi-lineage hematopoietic abnormalities or pancytopenia. The deficiency in hematopoietic progenitor cells (HPCs) induced by HIV-1 infection has been proposed, but the relevant mechanisms are poorly understood. We report here that both human CD34+CD38- early and CD34+CD38+ intermediate HPCs were maintained in the bone marrow (BM) of humanized mice. Chronic HIV-1 infection preferentially depleted CD34+CD38- early HPCs in the BM and reduced their proliferation potential in vivo in both HIV-1-infected patients and humanized mice, while CD34+CD38+ intermediate HSCs were relatively unaffected. Strikingly, depletion of plasmacytoid dendritic cells (pDCs) prevented human CD34+CD38- early HPCs from HIV-1 infection-induced depletion and functional impairment and restored the gene expression profile of purified CD34+ HPCs in humanized mice. These findings suggest that pDCs contribute to the early hematopoietic suppression induced by chronic HIV-1 infection and provide a novel therapeutic target for the hematopoiesis suppression in HIV-1 patients.

  8. Intermediate filament protein nestin is expressed in developing meninges.

    PubMed

    Yay, A; Ozdamar, S; Canoz, O; Baran, M; Tucer, B; Sonmez, M F

    2014-01-01

    Nestin is a type VI intermediate filament protein known as a marker for progenitor cells that can be mostly found in tissues during the embryonic and fetal periods. In our study, we aimed to determine the expression of nestin in meninges covering the brain tissue at different developmental stages and in the new born. In this study 10 human fetuses in different development stages between developmental weeks 9-34 and a newborn brain tissue were used. Fetuses in paraffin section were stained with H+E and nestin immunohistochemical staining protocol was performed. In this study, in the human meninges intense nestin expression was detected as early as in the 9th week of development. Intensity of this expression gradually decreased in later stages of development and nestin expression still persisted in a small population of newborn meningeal cells. In the present study, nestin positive cells gradually diminished in the developing and maturing meninges during the fetal period. This probably depends on initiation of a decrease in nestin expression and replacement with other tissue-specific intermediate filaments while the differentiation process continues. These differences can make significant contributions to the investigation and diagnosis of various pathological disorders (Tab. 1, Fig. 3, Ref. 36).

  9. Haploinsufficiency for the Six2 gene increases nephron progenitor proliferation promoting branching and nephron number.

    PubMed

    Combes, Alexander N; Wilson, Sean; Phipson, Belinda; Binnie, Brandon B; Ju, Adler; Lawlor, Kynan T; Cebrian, Cristina; Walton, Sarah L; Smyth, Ian M; Moritz, Karen M; Kopan, Raphael; Oshlack, Alicia; Little, Melissa H

    2018-03-01

    The regulation of final nephron number in the kidney is poorly understood. Cessation of nephron formation occurs when the self-renewing nephron progenitor population commits to differentiation. Transcription factors within this progenitor population, such as SIX2, are assumed to control expression of genes promoting self-renewal such that homozygous Six2 deletion results in premature commitment and an early halt to kidney development. In contrast, Six2 heterozygotes were assumed to be unaffected. Using quantitative morphometry, we found a paradoxical 18% increase in ureteric branching and final nephron number in Six2 heterozygotes, despite evidence for reduced levels of SIX2 protein and transcript. This was accompanied by a clear shift in nephron progenitor identity with a distinct subset of downregulated progenitor genes such as Cited1 and Meox1 while other genes were unaffected. The net result was an increase in nephron progenitor proliferation, as assessed by elevated EdU (5-ethynyl-2'-deoxyuridine) labeling, an increase in MYC protein, and transcriptional upregulation of MYC target genes. Heterozygosity for Six2 on an Fgf20-/- background resulted in premature differentiation of the progenitor population, confirming that progenitor regulation is compromised in Six2 heterozygotes. Overall, our studies reveal a unique dose response of nephron progenitors to the level of SIX2 protein in which the role of SIX2 in progenitor proliferation versus self-renewal is separable. Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  10. Circulating hematopoietic progenitor cells in patients affected by Chornobyl accident.

    PubMed

    Bilko, N M; Dyagil, I S; Russu, I Z; Bilko, D I

    2016-12-01

    High radiation sensitivity of stem cells and their ability to accumulate sublethal radiation damage provides the basis for investigation of hematopoietic progenitors using in vivo culture methodology. Unique samples of peripheral blood and bone marrow were derived from the patients affected by Chornobyl accident during liquidation campaign. To investigate functional activity of circulating hematopoietic progenitor cells from peripheral blood and bone marrow of cleanup workers in early and remote periods after the accident at Chornobyl nuclear power plant (CNPP). The assessment of the functional activity of circulating hematopoietic progenitor cells was performed in samples of peripheral blood and bone marrow of 46 cleanup workers, who were treated in the National Scientific Center for Radiation Medicine of the Academy of Medical Sciences of Ukraine alongside with 35 non radiated patients, who served as a control. Work was performed by culturing peripheral blood and bone marrow mononuclear cells in the original gel diffusion capsules, implanted into the peritoneal cavity of CBA mice. It was shown that hematopoietic progenitor cells could be identified in the peripheral blood of liquidators of CNPP accident. At the same time the number of functionally active progenitor cells of the bone marrow was significantly decreased and during the next 10 years after the accident, counts of circulating progenitor cells in the peripheral blood as well as functionally active hematopoietic cells in bone marrow returned to normal levels. It was shown that hematopoietic progenitor cells are detected not only in the bone marrow but also in the peripheral blood of liquidators as a consequence of radiation exposure associated with CNPP accident. This article is a part of a Special Issue entitled "The Chornobyl Nuclear Accident: Thirty Years After".

  11. Hematopoietic progenitors express neural genes

    PubMed Central

    Goolsby, James; Marty, Marie C.; Heletz, Dafna; Chiappelli, Joshua; Tashko, Gerti; Yarnell, Deborah; Fishman, Paul S.; Dhib-Jalbut, Suhayl; Bever, Christopher T.; Pessac, Bernard; Trisler, David

    2003-01-01

    Bone marrow, or cells selected from bone marrow, were reported recently to give rise to cells with a neural phenotype after in vitro treatment with neural-inducing factors or after delivery into the brain. However, we showed previously that untreated bone marrow cells express products of the neural myelin basic protein gene, and we demonstrate here that a subset of ex vivo bone marrow cells expresses the neurogenic transcription factor Pax-6 as well as neuronal genes encoding neurofilament H, NeuN (neuronal nuclear protein), HuC/HuD (Hu-antigen C/Hu-antigen D), and GAD65 (glutamic acid decarboxylase 65), as well as the oligodendroglial gene encoding CNPase (2′,3′ cyclic nucleotide 3′-phosphohydrolase). In contrast, astroglial glial fibrillary acidic protein (GFAP) was not detected. These cells also were CD34+, a marker of hematopoietic stem cells. Cultures of these highly proliferative CD34+ cells, derived from adult mouse bone marrow, uniformly displayed a phenotype comparable with that of hematopoietic progenitor cells (CD45+, CD34+, Sca-1+, AA4.1+, cKit+, GATA-2+, and LMO-2+). The neuronal and oligodendroglial genes expressed in ex vivo bone marrow also were expressed in all cultured CD34+ cells, and GFAP was not observed. After CD34+ cell transplantation into adult brain, neuronal or oligodendroglial markers segregated into distinct nonoverlapping cell populations, whereas astroglial GFAP appeared, in the absence of other neural markers, in a separate set of implanted cells. Thus, neuronal and oligodendroglial gene products are present in a subset of bone marrow cells, and the expression of these genes can be regulated in brain. The fact that these CD34+ cells also express transcription factors (Rex-1 and Oct-4) that are found in early development elicits the hypothesis that they may be pluripotent embryonic-like stem cells. PMID:14634211

  12. Embryonic Heart Progenitors and Cardiogenesis

    PubMed Central

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

    2013-01-01

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

  13. In vitro culture of stress erythroid progenitors identifies distinct progenitor populations and analogous human progenitors.

    PubMed

    Xiang, Jie; Wu, Dai-Chen; Chen, Yuanting; Paulson, Robert F

    2015-03-12

    Tissue hypoxia induces a systemic response designed to increase oxygen delivery to tissues. One component of this response is increased erythropoiesis. Steady-state erythropoiesis is primarily homeostatic, producing new erythrocytes to replace old erythrocytes removed from circulation by the spleen. In response to anemia, the situation is different. New erythrocytes must be rapidly made to increase hemoglobin levels. At these times, stress erythropoiesis predominates. Stress erythropoiesis is best characterized in the mouse, where it is extramedullary and utilizes progenitors and signals that are distinct from steady-state erythropoiesis. In this report, we use an in vitro culture system that recapitulates the in vivo development of stress erythroid progenitors. We identify cell-surface markers that delineate a series of stress erythroid progenitors with increasing maturity. In addition, we use this in vitro culture system to expand human stress erythroid progenitor cells that express analogous cell-surface markers. Consistent with previous suggestions that human stress erythropoiesis is similar to fetal erythropoiesis, we demonstrate that human stress erythroid progenitors express fetal hemoglobin upon differentiation. These data demonstrate that similar to murine bone marrow, human bone marrow contains cells that can generate BMP4-dependent stress erythroid burst-forming units when cultured under stress erythropoiesis conditions. © 2015 by The American Society of Hematology.

  14. Signatures of progenitors of Type Ia supernovae

    NASA Astrophysics Data System (ADS)

    Hoeflich, P.; Chakraborty, S.; Comaskey, W.; Fisher, A.; Hristov, B.; Collins, D.; Diamond, T. R.; Dragulin, P.; Hsiao, E. Y.; Sadler, B.

    Thermonuclear Supernovae (SNe Ia) are one of the building blocks of modern cosmology and laboratories for the explosion physics of White Dwarf star/s (WD) in close binary systems. The second star may be a WD (double degenerate systems, DD), or a non-degenerated star (SD) with a main sequence star, red giant or a helium star as companion \\citep{branch95,nomoto03,wang2012}. Light curves and spectra of the explosion look similar because a 'stellar amnesia' \\citep{h06}. Basic nuclear physics determines the progenitor structure and the explosion physics, breaking the link between progenitor evolution, and the explosion, resulting in three main classes of explosion scenarios: a) dynamical merging of two WD and a heating on time scales of seconds \\citep{webbink84,isern11}, b) surface helium detonations on top of a WD which ignite the central C/O by a detonation wave traveling inwards \\citep{n82,hk96,Kromer2010}; c) compressional heating in an accreting WD approaching the Chandrasekar mass on time of up to 108 years which may originated from SD and DD systems \\citep{WI73,Piersanti2004}. Simulations of the explosions depend on the inital conditions at the onset of the explosions, namely the mass and angular momentum of the WD(s). For all scenarios, diversity in SNe Ia must be expected because the WD originates from a range of Main Sequence masses (MMS < 8 M_⊙) and metallicities Z. Moreover, there is growing evidence that magnetic fields B may have to be added to the 'mix'. Only with recent advances in observations ranging from X-ray to radio, high precision spectroscopy, polarimetry and photometry and in the time-domain astronomy we obtain constraints for progenitor, on the explosion scenarios and links emerge between the progenitors and their environment with LCs and spectral signatures needed for high precision cosmology. It is too early to give final answers but we present our personal view. We will give some examples from the theory point of view and discuss

  15. Acquisition of granule neuron precursor identity is a critical determinant of progenitor cell competence to form Hedgehog-induced medulloblastoma

    PubMed Central

    Schüller, Ulrich; Heine, Vivi M.; Mao, Junhao; Kho, Alvin T.; Dillon, Allison K.; Han, Young-Goo; Huillard, Emmanuelle; Sun, Tao; Ligon, Azra H.; Qian, Ying; Ma, Qiufu; Alvarez-Buylla, Arturo; McMahon, Andrew P.; Rowitch, David H.; Ligon, Keith L.

    2008-01-01

    Origins of the brain tumor, medulloblastoma, from stem cells or restricted progenitor cells are unclear. To investigate this, we activated oncogenic Hedgehog (Hh) signaling in multipotent and lineage-restricted CNS progenitors. We observed that normal unipotent cerebellar granule neuron precursors (CGNP) derive from hGFAP+ and Olig2+ RL progenitors. Hh activation in a spectrum of early and late stage CNS progenitors generated similar medulloblastomas, but not other brain cancers, indicating that acquisition of CGNP identity is essential for tumorigenesis. We show in human and mouse medulloblastoma that cells expressing the glia-associated markers Gfap and Olig2 are neoplastic and that they retain features of embryonic-type granule lineage progenitors. Thus, oncogenic Hh signaling promotes medulloblastoma from lineage-restricted granule cell progenitors. PMID:18691547

  16. Molecular characterization of the major membrane skeletal protein in the ciliate Tetrahymena pyriformis suggests n-plication of an early evolutionary intermediate filament protein subdomain.

    PubMed

    Bouchard, P; Chomilier, J; Ravet, V; Mornon, J P; Viguès, B

    2001-01-01

    Epiplasmin C is the major protein component of the membrane skeleton in the ciliate Tetrahymena pyriformis. Cloning and analysis of the gene encoding epiplasmin C showed this protein to be a previously unrecognized protein. In particular, epiplasmin C was shown to lack the canonical features of already known epiplasmic proteins in ciliates and flagellates. By means of hydrophobic cluster analysis (HCA), it has been shown that epiplasmin C is constituted of a repeat of 25 domains of 40 residues each. These domains are related and can be grouped in two families called types I and types II. Connections between types I and types II present rules that can be evidenced in the sequence itself, thus enforcing the validity of the splitting of the domains. Using these repeated domains as queries, significant structural similarities were demonstrated with an extra six heptads shared by nuclear lamins and invertebrate cytoplasmic intermediate filament proteins and deleted in the cytoplasmic intermediate filament protein lineage at the protostome-deuterostome branching in the eukaryotic phylogenetic tree.

  17. STK-1, the human homolog of Flk-2/Flt-3, is selectively expressed in CD34+ human bone marrow cells and is involved in the proliferation of early progenitor/stem cells.

    PubMed Central

    Small, D; Levenstein, M; Kim, E; Carow, C; Amin, S; Rockwell, P; Witte, L; Burrow, C; Ratajczak, M Z; Gewirtz, A M

    1994-01-01

    We cloned the cDNA for stem cell tyrosine kinase 1 (STK-1), the human homolog of murine Flk-2/Flt-3, from a CD34+ hematopoietic stem cell-enriched library and investigated its expression in subsets of normal human bone marrow. The cDNA encodes a protein of 993 aa with 85% identity and 92% similarity to Flk-2/Flt-3. STK-1 is a member of the type III receptor tyrosine kinase family that includes KIT (steel factor receptor), FMS (colony-stimulating factor 1R), and platelet-derived growth factor receptor. STK-1 expression in human blood and marrow is restricted to CD34+ cells, a population greatly enriched for stem/progenitor cells. Anti-STK-1 antiserum recognizes polypeptides of 160 and 130 kDa in several STK-1-expressing cell lines and in 3T3 cells transfected with a STK-1 expression vector. Antisense oligonucleotides directed against STK-1 sequences inhibited hematopoietic colony formation, most strongly in long-term bone marrow cultures. These data suggest that STK-1 may function as a growth factor receptor on hematopoietic stem and/or progenitor cells. Images Fig. 2 Fig. 3 Fig. 4 PMID:7507245

  18. On the Progenitor of Binary Neutron Star Merger GW170817

    NASA Astrophysics Data System (ADS)

    Abbott, B. P.; Abbott, R.; Abbott, T. D.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Adya, V. B.; Affeldt, C.; Afrough, M.; Agarwal, B.; Agathos, M.; Agatsuma, K.; Aggarwal, N.; Aguiar, O. D.; Aiello, L.; Ain, A.; Ajith, P.; Allen, B.; Allen, G.; Allocca, A.; Altin, P. A.; Amato, A.; Ananyeva, A.; Anderson, S. B.; Anderson, W. G.; Angelova, S. V.; Antier, S.; Appert, S.; Arai, K.; Araya, M. C.; Areeda, J. S.; Arnaud, N.; Arun, K. G.; Ascenzi, S.; Ashton, G.; Ast, M.; Aston, S. M.; Astone, P.; Atallah, D. V.; Aufmuth, P.; Aulbert, C.; AultONeal, K.; Austin, C.; Avila-Alvarez, A.; Babak, S.; Bacon, P.; Bader, M. K. M.; Bae, S.; Baker, P. T.; Baldaccini, F.; Ballardin, G.; Ballmer, S. W.; Banagiri, S.; Barayoga, J. C.; Barclay, S. E.; Barish, B. C.; Barker, D.; Barkett, K.; Barone, F.; Barr, B.; Barsotti, L.; Barsuglia, M.; Barta, D.; Bartlett, J.; Bartos, I.; Bassiri, R.; Basti, A.; Batch, J. C.; Bawaj, M.; Bayley, J. C.; Bazzan, M.; Bécsy, B.; Beer, C.; Bejger, M.; Belahcene, I.; Bell, A. S.; Berger, B. K.; Bergmann, G.; Bero, J. J.; Berry, C. P. L.; Bersanetti, D.; Bertolini, A.; Betzwieser, J.; Bhagwat, S.; Bhandare, R.; Bilenko, I. A.; Billingsley, G.; Billman, C. R.; Birch, J.; Birney, R.; Birnholtz, O.; Biscans, S.; Biscoveanu, S.; Bisht, A.; Bitossi, M.; Biwer, C.; Bizouard, M. A.; Blackburn, J. K.; Blackman, J.; Blair, C. D.; Blair, D. G.; Blair, R. M.; Bloemen, S.; Bock, O.; Bode, N.; Boer, M.; Bogaert, G.; Bohe, A.; Bondu, F.; Bonilla, E.; Bonnand, R.; Boom, B. A.; Bork, R.; Boschi, V.; Bose, S.; Bossie, K.; Bouffanais, Y.; Bozzi, A.; Bradaschia, C.; Brady, P. R.; Branchesi, M.; Brau, J. E.; Briant, T.; Brillet, A.; Brinkmann, M.; Brisson, V.; Brockill, P.; Broida, J. E.; Brooks, A. F.; Brown, D. D.; Brunett, S.; Buchanan, C. C.; Buikema, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Buskulic, D.; Buy, C.; Byer, R. L.; Cabero, M.; Cadonati, L.; Cagnoli, G.; Cahillane, C.; Calderón Bustillo, J.; Callister, T. A.; Calloni, E.; Camp, J. B.; Canepa, M.; Canizares, P.; Cannon, K. C.; Cao, H.; Cao, J.; Capano, C. D.; Capocasa, E.; Carbognani, F.; Caride, S.; Carney, M. F.; Casanueva Diaz, J.; Casentini, C.; Caudill, S.; Cavaglià, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C. B.; Cerdá-Durán, P.; Cerretani, G.; Cesarini, E.; Chamberlin, S. J.; Chan, M.; Chao, S.; Charlton, P.; Chase, E.; Chassande-Mottin, E.; Chatterjee, D.; Cheeseboro, B. D.; Chen, H. Y.; Chen, X.; Chen, Y.; Cheng, H.-P.; Chia, H.; Chincarini, A.; Chiummo, A.; Chmiel, T.; Cho, H. S.; Cho, M.; Chow, J. H.; Christensen, N.; Chu, Q.; Chua, A. J. K.; Chua, S.; Chung, A. K. W.; Chung, S.; Ciani, G.; Ciolfi, R.; Cirelli, C. E.; Cirone, A.; Clara, F.; Clark, J. A.; Clearwater, P.; Cleva, F.; Cocchieri, C.; Coccia, E.; Cohadon, P.-F.; Cohen, D.; Colla, A.; Collette, C. G.; Cominsky, L. R.; Constancio, M., Jr.; Conti, L.; Cooper, S. J.; Corban, P.; Corbitt, T. R.; Cordero-Carrión, I.; Corley, K. R.; Corsi, A.; Cortese, S.; Costa, C. A.; Coughlin, M. W.; Coughlin, S. B.; Coulon, J.-P.; Countryman, S. T.; Couvares, P.; Covas, P. B.; Cowan, E. E.; Coward, D. M.; Cowart, M. J.; Coyne, D. C.; Coyne, R.; Creighton, J. D. E.; Creighton, T. D.; Cripe, J.; Crowder, S. G.; Cullen, T. J.; Cumming, A.; Cunningham, L.; Cuoco, E.; Dal Canton, T.; Dálya, G.; Danilishin, S. L.; D'Antonio, S.; Danzmann, K.; Dasgupta, A.; Da Silva Costa, C. F.; Dattilo, V.; Dave, I.; Davier, M.; Davis, D.; Daw, E. J.; Day, B.; De, S.; DeBra, D.; Degallaix, J.; De Laurentis, M.; Deléglise, S.; Del Pozzo, W.; Demos, N.; Denker, T.; Dent, T.; De Pietri, R.; Dergachev, V.; De Rosa, R.; DeRosa, R. T.; De Rossi, C.; DeSalvo, R.; de Varona, O.; Devenson, J.; Dhurandhar, S.; Díaz, M. C.; Di Fiore, L.; Di Giovanni, M.; Di Girolamo, T.; Di Lieto, A.; Di Pace, S.; Di Palma, I.; Di Renzo, F.; Doctor, Z.; Dolique, V.; Donovan, F.; Dooley, K. L.; Doravari, S.; Dorrington, I.; Douglas, R.; Dovale Álvarez, M.; Downes, T. P.; Drago, M.; Dreissigacker, C.; Driggers, J. C.; Du, Z.; Ducrot, M.; Dupej, P.; Dwyer, S. E.; Edo, T. B.; Edwards, M. C.; Effler, A.; Eggenstein, H.-B.; Ehrens, P.; Eichholz, J.; Eikenberry, S. S.; Eisenstein, R. A.; Essick, R. C.; Estevez, D.; Etienne, Z. B.; Etzel, T.; Evans, M.; Evans, T. M.; Factourovich, M.; Fafone, V.; Fair, H.; Fairhurst, S.; Fan, X.; Farinon, S.; Farr, B.; Farr, W. M.; Fauchon-Jones, E. J.; Favata, M.; Fays, M.; Fee, C.; Fehrmann, H.; Feicht, J.; Fejer, M. M.; Fernandez-Galiana, A.; Ferrante, I.; Ferreira, E. C.; Ferrini, F.; Fidecaro, F.; Finstad, D.; Fiori, I.; Fiorucci, D.; Fishbach, M.; Fisher, R. P.; Fitz-Axen, M.; Flaminio, R.; Fletcher, M.; Fong, H.; Font, J. A.; Forsyth, P. W. F.; Forsyth, S. S.; Fournier, J.-D.; Frasca, S.; Frasconi, F.; Frei, Z.; Freise, A.; Frey, R.; Frey, V.; Fries, E. M.; Fritschel, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Gabbard, H.; Gadre, B. U.; Gaebel, S. M.; Gair, J. R.; Gammaitoni, L.; Ganija, M. R.; Gaonkar, S. G.; Garcia-Quiros, C.; Garufi, F.; Gateley, B.; Gaudio, S.; Gaur, G.; Gayathri, V.; Gehrels, N.; Gemme, G.; Genin, E.; Gennai, A.; George, D.; George, J.; Gergely, L.; Germain, V.; Ghonge, S.; Ghosh, Abhirup; Ghosh, Archisman; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gill, K.; Glover, L.; Goetz, E.; Goetz, R.; Gomes, S.; Goncharov, B.; Gonzalez Castro, J. M.; Gopakumar, A.; Gorodetsky, M. L.; Gossan, S. E.; Gosselin, M.; Gouaty, R.; Grado, A.; Graef, C.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Greco, G.; Green, A. C.; Gretarsson, E. M.; Groot, P.; Grote, H.; Grunewald, S.; Gruning, P.; Guidi, G. M.; Guo, X.; Gupta, A.; Gupta, M. K.; Gushwa, K. E.; Gustafson, E. K.; Gustafson, R.; Halim, O.; Hall, B. R.; Hall, E. D.; Hamilton, E. Z.; Hammond, G.; Haney, M.; Hanke, M. M.; Hanks, J.; Hanna, C.; Hannam, M. D.; Hannuksela, O. A.; Hanson, J.; Hardwick, T.; Harms, J.; Harry, G. M.; Harry, I. W.; Hart, M. J.; Haster, C.-J.; Haughian, K.; Healy, J.; Heidmann, A.; Heintze, M. C.; Heitmann, H.; Hello, P.; Hemming, G.; Hendry, M.; Heng, I. S.; Hennig, J.; Heptonstall, A. W.; Heurs, M.; Hild, S.; Hinderer, T.; Hoak, D.; Hofman, D.; Holgado, A. M.; Holt, K.; Holz, D. E.; Hopkins, P.; Horst, C.; Hough, J.; Houston, E. A.; Howell, E. J.; Hreibi, A.; Hu, Y. M.; Huerta, E. A.; Huet, D.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh-Dinh, T.; Indik, N.; Inta, R.; Intini, G.; Isa, H. N.; Isac, J.-M.; Isi, M.; Iyer, B. R.; Izumi, K.; Jacqmin, T.; Jani, K.; Jaranowski, P.; Jawahar, S.; Jiménez-Forteza, F.; Johnson, W. W.; Jones, D. I.; Jones, R.; Jonker, R. J. G.; Ju, L.; Junker, J.; Kalaghatgi, C. V.; Kalogera, V.; Kamai, B.; Kandhasamy, S.; Kang, G.; Kanner, J. B.; Kapadia, S. J.; Karki, S.; Karvinen, K. S.; Kasprzack, M.; Katolik, M.; Katsavounidis, E.; Katzman, W.; Kaufer, S.; Kawabe, K.; Kéfélian, F.; Keitel, D.; Kemball, A. J.; Kennedy, R.; Kent, C.; Key, J. S.; Khalili, F. Y.; Khan, I.; Khan, S.; Khan, Z.; Khazanov, E. A.; Kijbunchoo, N.; Kim, Chunglee; Kim, J. C.; Kim, K.; Kim, W.; Kim, W. S.; Kim, Y.-M.; Kimball, C.; Kimbrell, S. J.; King, E. J.; King, P. J.; Kinley-Hanlon, M.; Kirchhoff, R.; Kissel, J. S.; Kleybolte, L.; Klimenko, S.; Knowles, T. D.; Koch, P.; Koehlenbeck, S. M.; Koley, S.; Kondrashov, V.; Kontos, A.; Korobko, M.; Korth, W. Z.; Kowalska, I.; Kozak, D. B.; Krämer, C.; Kringel, V.; Królak, A.; Kuehn, G.; Kumar, P.; Kumar, R.; Kumar, S.; Kuo, L.; Kutynia, A.; Kwang, S.; Lackey, B. D.; Lai, K. H.; Landry, M.; Lang, R. N.; Lange, J.; Lantz, B.; Lanza, R. K.; Larson, S. L.; Lartaux-Vollard, A.; Lasky, P. D.; Laxen, M.; Lazzarini, A.; Lazzaro, C.; Leaci, P.; Leavey, S.; Lee, C. H.; Lee, H. K.; Lee, H. M.; Lee, H. W.; Lee, K.; Lehmann, J.; Lenon, A.; Leonardi, M.; Leroy, N.; Letendre, N.; Levin, Y.; Li, T. G. F.; Linker, S. D.; Littenberg, T. B.; Liu, J.; Lo, R. K. L.; Lockerbie, N. A.; London, L. T.; Lord, J. E.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lough, J. D.; Lousto, C. O.; Lovelace, G.; Lück, H.; Lumaca, D.; Lundgren, A. P.; Lynch, R.; Ma, Y.; Macas, R.; Macfoy, S.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Magaña Hernandez, I.; Magaña-Sandoval, F.; Magaña Zertuche, L.; Magee, R. M.; Majorana, E.; Maksimovic, I.; Man, N.; Mandic, V.; Mangano, V.; Mansell, G. L.; Manske, M.; Mantovani, M.; Marchesoni, F.; Marion, F.; Márka, S.; Márka, Z.; Markakis, C.; Markosyan, A. S.; Markowitz, A.; Maros, E.; Marquina, A.; Martelli, F.; Martellini, L.; Martin, I. W.; Martin, R. M.; Martynov, D. V.; Mason, K.; Massera, E.; Masserot, A.; Massinger, T. J.; Masso-Reid, M.; Mastrogiovanni, S.; Matas, A.; Matichard, F.; Matone, L.; Mavalvala, N.; Mazumder, N.; McCarthy, R.; McClelland, D. E.; McCormick, S.; McCuller, L.; McGuire, S. C.; McIntyre, G.; McIver, J.; McManus, D. J.; McNeill, L.; McRae, T.; McWilliams, S. T.; Meacher, D.; Meadors, G. D.; Mehmet, M.; Meidam, J.; Mejuto-Villa, E.; Melatos, A.; Mendell, G.; Mercer, R. A.; Merilh, E. L.; Merzougui, M.; Meshkov, S.; Messenger, C.; Messick, C.; Metzdorff, R.; Meyers, P. M.; Miao, H.; Michel, C.; Middleton, H.; Mikhailov, E. E.; Milano, L.; Miller, A. L.; Miller, B. B.; Miller, J.; Millhouse, M.; Milovich-Goff, M. C.; Minazzoli, O.; Minenkov, Y.; Ming, J.; Mishra, C.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Moffa, D.; Moggi, A.; Mogushi, K.; Mohan, M.; Mohapatra, S. R. P.; Montani, M.; Moore, C. J.; Moraru, D.; Moreno, G.; Morriss, S. R.; Mours, B.; Mow-Lowry, C. M.; Mueller, G.; Muir, A. W.; Mukherjee, Arunava; Mukherjee, D.; Mukherjee, S.; Mukund, N.; Mullavey, A.; Munch, J.; Muñiz, E. A.; Muratore, M.; Murray, P. G.; Napier, K.; Nardecchia, I.; Naticchioni, L.; Nayak, R. K.; Neilson, J.; Nelemans, G.; Nelson, T. J. N.; Nery, M.; Neunzert, A.; Nevin, L.; Newport, J. M.; Newton, G.; Ng, K. K. Y.; Nguyen, T. T.; Nichols, D.; Nielsen, A. B.; Nissanke, S.; Nitz, A.; Noack, A.; Nocera, F.; Nolting, D.; North, C.; Nuttall, L. K.; Oberling, J.; O'Dea, G. D.; Ogin, G. H.; Oh, J. J.; Oh, S. H.; Ohme, F.; Okada, M. A.; Oliver, M.; Oppermann, P.; Oram, Richard J.; O'Reilly, B.; Ormiston, R.; Ortega, L. F.; O'Shaughnessy, R.; Ossokine, S.; Ottaway, D. J.; Overmier, H.; Owen, B. J.; Pace, A. E.; Page, J.; Page, M. A.; Pai, A.; Pai, S. A.; Palamos, J. R.; Palashov, O.; Palomba, C.; Pal-Singh, A.; Pan, Howard; Pan, Huang-Wei; Pang, B.; Pang, P. T. H.; Pankow, C.; Pannarale, F.; Pant, B. C.; Paoletti, F.; Paoli, A.; Papa, M. A.; Parida, A.; Parker, W.; Pascucci, D.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patil, M.; Patricelli, B.; Pearlstone, B. L.; Pedraza, M.; Pedurand, R.; Pekowsky, L.; Pele, A.; Penn, S.; Perez, C. J.; Perreca, A.; Perri, L. M.; Pfeiffer, H. P.; Phelps, M.; Piccinni, O. J.; Pichot, M.; Piergiovanni, F.; Pierro, V.; Pillant, G.; Pinard, L.; Pinto, I. M.; Pirello, M.; Pitkin, M.; Poe, M.; Poggiani, R.; Popolizio, P.; Porter, E. K.; Post, A.; Powell, J.; Prasad, J.; Pratt, J. W. W.; Pratten, G.; Predoi, V.; Prestegard, T.; Prijatelj, M.; Principe, M.; Privitera, S.; Prodi, G. A.; Prokhorov, L. G.; Puncken, O.; Punturo, M.; Puppo, P.; Pürrer, M.; Qi, H.; Quetschke, V.; Quintero, E. A.; Quitzow-James, R.; Rabeling, D. S.; Radkins, H.; Raffai, P.; Raja, S.; Rajan, C.; Rajbhandari, B.; Rakhmanov, M.; Ramirez, K. E.; Ramos-Buades, A.; Rapagnani, P.; Raymond, V.; Razzano, M.; Read, J.; Regimbau, T.; Rei, L.; Reid, S.; Reitze, D. H.; Ren, W.; Reyes, S. D.; Ricci, F.; Ricker, P. M.; Rieger, S.; Riles, K.; Rizzo, M.; Robertson, N. A.; Robie, R.; Robinet, F.; Rocchi, A.; Rolland, L.; Rollins, J. G.; Roma, V. J.; Romano, R.; Romel, C. L.; Romie, J. H.; Rosińska, D.; Ross, M. P.; Rowan, S.; Rüdiger, A.; Ruggi, P.; Rutins, G.; Ryan, K.; Sachdev, S.; Sadecki, T.; Sadeghian, L.; Sakellariadou, M.; Salconi, L.; Saleem, M.; Salemi, F.; Samajdar, A.; Sammut, L.; Sampson, L. M.; Sanchez, E. J.; Sanchez, L. E.; Sanchis-Gual, N.; Sandberg, V.; Sanders, J. R.; Sassolas, B.; Sathyaprakash, B. S.; Sauter, O.; Savage, R. L.; Sawadsky, A.; Schale, P.; Scheel, M.; Scheuer, J.; Schmidt, J.; Schmidt, P.; Schnabel, R.; Schofield, R. M. S.; Schönbeck, A.; Schreiber, E.; Schuette, D.; Schulte, B. W.; Schutz, B. F.; Schwalbe, S. G.; Scott, J.; Scott, S. M.; Seidel, E.; Sellers, D.; Sengupta, A. S.; Sentenac, D.; Sequino, V.; Sergeev, A.; Shaddock, D. A.; Shaffer, T. J.; Shah, A. A.; Shahriar, M. S.; Shaner, M. B.; Shao, L.; Shapiro, B.; Shawhan, P.; Sheperd, A.; Shoemaker, D. H.; Shoemaker, D. M.; Siellez, K.; Siemens, X.; Sieniawska, M.; Sigg, D.; Silva, A. D.; Singer, L. P.; Singh, A.; Singhal, A.; Sintes, A. M.; Slagmolen, B. J. J.; Smith, B.; Smith, J. R.; Smith, R. J. E.; Somala, S.; Son, E. J.; Sonnenberg, J. A.; Sorazu, B.; Sorrentino, F.; Souradeep, T.; Spencer, A. P.; Srivastava, A. K.; Staats, K.; Staley, A.; Steinke, M.; Steinlechner, J.; Steinlechner, S.; Steinmeyer, D.; Stevenson, S. P.; Stone, R.; Stops, D. J.; Strain, K. A.; Stratta, G.; Strigin, S. E.; Strunk, A.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sun, L.; Sunil, S.; Suresh, J.; Sutton, P. J.; Swinkels, B. L.; Szczepańczyk, M. J.; Tacca, M.; Tait, S. C.; Talbot, C.; Talukder, D.; Tanner, D. B.; Tápai, M.; Taracchini, A.; Tasson, J. D.; Taylor, J. A.; Taylor, R.; Tewari, S. V.; Theeg, T.; Thies, F.; Thomas, E. G.; Thomas, M.; Thomas, P.; Thorne, K. A.; Thrane, E.; Tiwari, S.; Tiwari, V.; Tokmakov, K. V.; Toland, K.; Tonelli, M.; Tornasi, Z.; Torres-Forné, A.; Torrie, C. I.; Töyrä, D.; Travasso, F.; Traylor, G.; Trinastic, J.; Tringali, M. C.; Trozzo, L.; Tsang, K. W.; Tse, M.; Tso, R.; Tsukada, L.; Tsuna, D.; Tuyenbayev, D.; Ueno, K.; Ugolini, D.; Unnikrishnan, C. S.; Urban, A. L.; Usman, S. A.; Vahlbruch, H.; Vajente, G.; Valdes, G.; van Bakel, N.; van Beuzekom, M.; van den Brand, J. F. J.; Van Den Broeck, C.; Vander-Hyde, D. C.; van der Schaaf, L.; van Heijningen, J. V.; van Veggel, A. A.; Vardaro, M.; Varma, V.; Vass, S.; Vasúth, M.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P. J.; Venkateswara, K.; Venugopalan, G.; Verkindt, D.; Vetrano, F.; Viceré, A.; Viets, A. D.; Vinciguerra, S.; Vine, D. J.; Vinet, J.-Y.; Vitale, S.; Vo, T.; Vocca, H.; Vorvick, C.; Vyatchanin, S. P.; Wade, A. R.; Wade, L. E.; Wade, M.; Walet, R.; Walker, M.; Wallace, L.; Walsh, S.; Wang, G.; Wang, H.; Wang, J. Z.; Wang, W. H.; Wang, Y. F.; Ward, R. L.; Warner, J.; Was, M.; Watchi, J.; Weaver, B.; Wei, L.-W.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Wen, L.; Wessel, E. K.; Weßels, P.; Westerweck, J.; Westphal, T.; Wette, K.; Whelan, J. T.; Whiting, B. F.; Whittle, C.; Wilken, D.; Williams, D.; Williams, R. D.; Williamson, A. R.; Willis, J. L.; Willke, B.; Wimmer, M. H.; Winkler, W.; Wipf, C. C.; Wittel, H.; Woan, G.; Woehler, J.; Wofford, J.; Wong, K. W. K.; Worden, J.; Wright, J. L.; Wu, D. S.; Wysocki, D. M.; Xiao, S.; Yamamoto, H.; Yancey, C. C.; Yang, L.; Yap, M. J.; Yazback, M.; Yu, Hang; Yu, Haocun; Yvert, M.; Zadrożny, A.; Zanolin, M.; Zelenova, T.; Zendri, J.-P.; Zevin, M.; Zhang, L.; Zhang, M.; Zhang, T.; Zhang, Y.-H.; Zhao, C.; Zhou, M.; Zhou, Z.; Zhu, S. J.; Zhu, X. J.; Zucker, M. E.; Zweizig, J.; (LIGO Scientific Collaboration; Virgo Collaboration

    2017-12-01

    On 2017 August 17 the merger of two compact objects with masses consistent with two neutron stars was discovered through gravitational-wave (GW170817), gamma-ray (GRB 170817A), and optical (SSS17a/AT 2017gfo) observations. The optical source was associated with the early-type galaxy NGC 4993 at a distance of just ˜40 Mpc, consistent with the gravitational-wave measurement, and the merger was localized to be at a projected distance of ˜2 kpc away from the galaxy’s center. We use this minimal set of facts and the mass posteriors of the two neutron stars to derive the first constraints on the progenitor of GW170817 at the time of the second supernova (SN). We generate simulated progenitor populations and follow the three-dimensional kinematic evolution from binary neutron star (BNS) birth to the merger time, accounting for pre-SN galactic motion, for considerably different input distributions of the progenitor mass, pre-SN semimajor axis, and SN-kick velocity. Though not considerably tight, we find these constraints to be comparable to those for Galactic BNS progenitors. The derived constraints are very strongly influenced by the requirement of keeping the binary bound after the second SN and having the merger occur relatively close to the center of the galaxy. These constraints are insensitive to the galaxy’s star formation history, provided the stellar populations are older than 1 Gyr.

  19. Retinoid-signaling in progenitors controls specification and regeneration of the urothelium

    PubMed Central

    Reiley, Maia; Laufer, Ed; Metzger, Daniel; Liang, Fengxia; Liao, Yi; Sun, Tung-Tien; Aronow, Bruce; Rosen, Roni; Mauney, Josh; Adam, Rosalyn; Rosselot, Carolina; Van Batavia, Jason; McMahon, Andrew; McMahon, Jill; Guo, Jin-Jin; Mendelsohn, Cathy

    2013-01-01

    The urothelium is a stratified epithelium that prevents exchange of water and toxic substances between the urinary tract and blood. It is composed of Keratin-5-expressing-basal-cells (K5-BCs), intermediate cells and superficial cells specialized for synthesis and transport of uroplakins that assemble into the apical barrier. K5-BCs are considered to be a progenitor cell type in the urothelium and other stratified epithelia. Fate mapping studies however, reveal that P-cells, a transient population, are urothelial progenitors in the embryo, intermediate cells are superficial cell progenitors in the adult regenerating urothelium, and K5-BCs are a distinct lineage. Our studies indicate that retinoids, potent regulators of ES cells and other progenitors, are also required in P-cells and intermediate cells for their specification. These observations have important implications for tissue engineering and repair, and ultimately, may lead to treatments that prevent loss of the urothelial barrier, a major cause of voiding dysfunction and bladder pain syndrome. PMID:23993789

  20. EFFECT OF TRICHLOROETHYLENE ON DNA METHYLATION AND EXPRESSION OF EARLY-INTERMEDIATE PROTOONCOGENES IN THE LIVER OF B6C3F1 MICE. (R825384)

    EPA Science Inventory

    Trichloroethylene (TCE) is a multimedia environmental pollution that is carcinogenic in mouse liver. The ability of TCE to modulate DNA methylation and the expression of immediate-early protooncogenes was evaluated. Female B6C3F1 mice were administered 1000 mg/kg TCE by gavage 5 ...

  1. Expansion and differentiation of neural progenitors derived from the human adult enteric nervous system.

    PubMed

    Metzger, Marco; Bareiss, Petra M; Danker, Timm; Wagner, Silvia; Hennenlotter, Joerg; Guenther, Elke; Obermayr, Florian; Stenzl, Arnulf; Koenigsrainer, Alfred; Skutella, Thomas; Just, Lothar

    2009-12-01

    Neural stem and progenitor cells from the enteric nervous system have been proposed for use in cell-based therapies against specific neurogastrointestinal disorders. Recently, enteric neural progenitors were generated from human neonatal and early postnatal (until 5 years after birth) gastrointestinal tract tissues. We investigated the proliferation and differentiation of enteric nervous system progenitors isolated from human adult gastrointestinal tract. Human enteric spheroids were generated from adult small and large intestine tissues and then expanded and differentiated, depending on the applied cell culture conditions. For implantation studies, spheres were grafted into fetal slice cultures and embryonic aganglionic hindgut explants from mice. Differentiating enteric neural progenitors were characterized by 5-bromo-2-deoxyuridine labeling, in situ hybridization, immunocytochemistry, quantitative real-time polymerase chain reaction, and electrophysiological studies. The yield of human neurosphere-like bodies was increased by culture in conditional medium derived from fetal mouse enteric progenitors. We were able to generate proliferating enterospheres from adult human small or large intestine tissues; these enterospheres could be subcultured and maintained for several weeks in vitro. Spheroid-derived cells could be differentiated into a variety of neuronal subtypes and glial cells with characteristics of the enteric nervous system. Experiments involving implantation into organotypic intestinal cultures showed the differentiation capacity of neural progenitors in a 3-dimensional environment. It is feasible to isolate and expand enteric progenitor cells from human adult tissue. These findings offer new strategies for enteric stem cell research and future cell-based therapies.

  2. PTF12os and iPTF13bvn: Two stripped-envelope supernovae from low-mass progenitors in NGC 5806

    DOE PAGES

    Fremling, C.; Sollerman, J.; Taddia, F.; ...

    2016-09-22

    Context. In this paper, we investigate two stripped-envelope supernovae (SNe) discovered in the nearby galaxy NGC 5806 by the (intermediate) Palomar Transient Factory [(i)PTF]. These SNe, designated PTF12os/SN 2012P and iPTF13bvn, exploded within ~520 days of one another at a similar distance from the host-galaxy center. We classify PTF12os as a Type IIb SN based on our spectral sequence; iPTF13bvn has previously been classified as Type Ib having a likely progenitor with zero age main sequence (ZAMS) mass below ~17 M ⊙. Because of the shared and nearby host, we are presented with a unique opportunity to compare these twomore » SNe. Aims. Our main objective is to constrain the explosion parameters of iPTF12os and iPTF13bvn, and to put constraints on the SN progenitors. We also aim to spatially map the metallicity in the host galaxy, and to investigate the presence of hydrogen in early-time spectra of both SNe. Methods. We present comprehensive datasets collected on PTF12os and iPTF13bvn, and introduce a new automatic reference-subtraction photometry pipeline (FPipe) currently in use by the iPTF. We perform a detailed study of the light curves (LCs) and spectral evolution of the SNe. The bolometric LCs are modeled using the hydrodynamical code hyde. We analyze early spectra of both SNe to investigate the presence of hydrogen; for iPTF13bvn we also investigate the regions of the Paschen lines in infrared spectra. We perform spectral line analysis of helium and iron lines to map the ejecta structure of both SNe. We use nebular models and late-time spectroscopy to constrain the ZAMS mass of the progenitors. We also perform image registration of ground-based images of PTF12os to archival HST images of NGC 5806 to identify a potential progenitor candidate. Results. We find that our nebular spectroscopy of iPTF13bvn remains consistent with a low-mass progenitor, likely having a ZAMS mass of ~12M ⊙. Our late-time spectroscopy of PTF12os is consistent with a ZAMS mass

  3. A morphological intermediate between eosimiiform and simiiform primates from the late middle Eocene of Tunisia: Macroevolutionary and paleobiogeographic implications of early anthropoids.

    PubMed

    Marivaux, Laurent; Essid, El Mabrouk; Marzougui, Wissem; Khayati Ammar, Hayet; Adnet, Sylvain; Marandat, Bernard; Merzeraud, Gilles; Ramdarshan, Anusha; Tabuce, Rodolphe; Vianey-Liaud, Monique; Yans, Johan

    2014-07-01

    Although advanced anthropoid primates (i.e., Simiiformes) are recorded at the end of the Eocene in North Africa (Proteopithecidae, Parapithecidae, and Oligopithecidae), the origin and emergence of this group has so far remained undocumented. The question as to whether these primates are the result of a monophyletic radiation of endemic anthropoids in Africa, or several Asian clades colonizing Africa, is a current focus of paleoprimatology. In this article, we report the discovery of a new anthropoid from Djebel el Kébar in central Tunisia, dating from the late middle Eocene (Bartonian). This taxon, Amamria tunisiensis, new genus and species, currently known by only one isolated upper molar, is among the most ancient anthropoids to be recorded in Africa thus far. Amamria displays a suite of dental features that are primarily observed in Eosimiiformes (stem Anthropoidea). However, it is not allocated to any known family of that group (i.e., Asian Eosimiidae and Afro-Asian Afrotarsiidae) inasmuch as it develops some dental traits that are unknown among eosimiiforms, but can be found in African simiiform anthropoids such as proteopithecids and oligopithecids. With such a mosaic of dental traits, Amamria appears to be a structural intermediate, and as such it could occupy a key position, close to the root of the African simiiforms. Given its antiquity and its apparent pivotal position, the possibility exists that Amamria could have evolved in Africa from Asian eosimiiform or Asian "proto"-simiiform ancestors, which would have entered Africa sometime during the middle Eocene. Amamria could then represent one of the earliest offshoots of the African simiiform radiation. This view would then be rather in favor of the hypothesis of a monophyletic radiation of endemic simiiform anthropoids in Africa. Finally, these new data suggest that there must have been at least two Asian anthropoid colonizers of Africa: the afrotarsiids and the ancestor of Amamria. © 2014 Wiley

  4. Move to improve: the feasibility of using an early mobility protocol to increase ambulation in the intensive and intermediate care settings.

    PubMed

    Drolet, Anne; DeJuilio, Patti; Harkless, Sherri; Henricks, Sherry; Kamin, Elizabeth; Leddy, Elizabeth A; Lloyd, Joanna M; Waters, Carissa; Williams, Sarah

    2013-02-01

    Prolonged bed rest in hospitalized patients leads to deconditioning, impaired mobility, and the potential for longer hospital stays. The purpose of this study was to determine the effectiveness of a nurse-driven mobility protocol to increase the percentage of patients ambulating during the first 72 hours of their hospital stay. A quasi-experimental design was used before and after intervention in a 16-bed adult medical/surgical intensive care unit (ICU) and a 26-bed adult intermediate care unit (IMCU) at a large community hospital. A multidisciplinary team developed and implemented a mobility order set with an embedded algorithm to guide nursing assessment of mobility potential. Based on the assessments, the protocol empowers the nurse to consult physical therapists or occupational therapists when appropriate. Daily ambulation status reports were reviewed each morning to determine each patient's activity level. Retrospective and prospective chart reviews were performed to evaluate the effectiveness of the protocol for patients 18 years of age and older who were hospitalized 72 hours or longer. In the 3 months prior to implementation of the Move to Improve project, 6.2% (12 of 193) of the ICU patients and 15.5% (54 of 349) of the IMCU patients ambulated during the first 72 hours of their hospitalization. During the 6 months following implementation, those rates rose to 20.2% (86 of 426) and 71.8% (257 of 358), respectively. The study was carried out at only one center. The initial experience with a nurse-driven mobility protocol suggests that the rate of patient ambulation in an adult ICU and IMCU during the first 72 hours of a hospital stay can be increased.

  5. Early treatment of imported falciparum malaria in the intermediate and intensive care unit setting: an 8-year single-center retrospective study.

    PubMed

    Schwake, Lukas; Streit, Judith Pamela; Edler, Lutz; Encke, Jens; Stremmel, Wolfgang; Junghanss, Thomas

    2008-01-01

    Imported falciparum malaria is characterized by a broad spectrum of potentially life-threatening complications that may arise even after initiation of appropriate antimalarial drug therapy. Hence, at Heidelberg University Hospital, all patients with newly diagnosed falciparum malaria are initially treated in the intermediate care unit (IMC) or intensive care unit (ICU). The present study was undertaken to evaluate critically the benefit of this strategy, which includes daily consultation with senior specialists in tropical medicine. We conducted a retrospective cohort study at the 14-bed combined IMC/ICU of a 1,685-bed university hospital. A cohort of 122 patients with imported falciparum malaria admitted from 1 January 1996 to 31 December 2003 was included. Thirty-four patients (27.9%) developed complications, defined according to the current World Health Organization classification. Most patients (80.3%) studied did not take the recommended chemoprophylaxis against malaria. The majority of patients (89.3% [n = 109]) could be adequately treated in the IMC. Life-threatening complications requiring ICU support occurred in 13 patients (10.7%). All complications were successfully managed. Fifty-five patients (45.1%) fulfilling recently published criteria for outpatient treatment had an excellent therapeutic response and did not require ICU support. This retrospective evaluation demonstrated favourable therapeutic results in hospitalized patients with imported falciparum malaria. Both initial treatment in the medical IMC/ICU and close collaboration between intensivists and specialists in tropical medicine may improve disease outcome among affected patients. Prospective studies are needed to confirm these preliminary findings.

  6. The Oligodendrocyte Progenitor Response to Demyelination

    DTIC Science & Technology

    2006-01-01

    DATE 2006 2. REPORT TYPE 3. DATES COVERED 00-00-2006 to 00-00-2006 4. TITLE AND SUBTITLE The Oligodendrocyte Progenitor Response to Demyelination...material in the thesis manuscript entitled: “The Oligodendrocyte Progenitor Response to Demyelination” is appropriately acknowledged and, beyond... oligodendrocyte progenitor (OP) amplification prior to remyelination. Myelin transcription factor 1 (Myt1) influences OP proliferation, differentiation, and

  7. Sympathetic activity and early mobilization in patients in intensive and intermediate care with severe brain injuries: a preliminary prospective randomized study.

    PubMed

    Rocca, A; Pignat, J-M; Berney, L; Jöhr, J; Van de Ville, D; Daniel, R T; Levivier, M; Hirt, L; Luft, A R; Grouzmann, E; Diserens, K

    2016-09-13

    Patients who experience severe brain injuries are at risk of secondary brain damage, because of delayed vasospasm and edema. Traditionally, many of these patients are kept on prolonged bed rest in order to maintain adequate cerebral blood flow, especially in the case of subarachnoid hemorrhage. On the other hand, prolonged bed rest carries important morbidity. There may be a clinical benefit in early mobilization and our hypothesis is that early gradual mobilization is safe in these patients. The aim of this study was to observe and quantify the changes in sympathetic activity, mainly related to stress, and blood pressure in gradual postural changes by the verticalization robot (Erigo®) and after training by a lower body ergometer (MOTOmed-letto®), after prolonged bed rest of minimum 7 days. Thirty patients with severe neurological injuries were randomized into 3 groups with different protocols of mobilization: Standard, MOTOmed-letto® or Erigo® protocol. We measured plasma catecholamines, metanephrines and blood pressure before, during and after mobilization. Blood pressure does not show any significant difference between the 3 groups. The analysis of the catecholamines suggests a significant increase in catecholamine production during Standard mobilization with physiotherapists and with MOTOmed-letto® and no changes with Erigo®. This preliminary prospective randomized study shows that the mobilization of patients with severe brain injuries by means of Erigo® does not increase the production of catecholamines. It means that Erigo® is a well-tolerated method of mobilization and can be considered a safe system of early mobilization of these patients. Further studies are required to validate our conclusions. The study was registered in the ISRCTN registry with the trial registration number ISRCTN56402432 . Date of registration: 08.03.2016. Retrospectively registered.

  8. Transcriptional diversity during lineage commitment of human blood progenitors.

    PubMed

    Chen, Lu; Kostadima, Myrto; Martens, Joost H A; Canu, Giovanni; Garcia, Sara P; Turro, Ernest; Downes, Kate; Macaulay, Iain C; Bielczyk-Maczynska, Ewa; Coe, Sophia; Farrow, Samantha; Poudel, Pawan; Burden, Frances; Jansen, Sjoert B G; Astle, William J; Attwood, Antony; Bariana, Tadbir; de Bono, Bernard; Breschi, Alessandra; Chambers, John C; Consortium, Bridge; Choudry, Fizzah A; Clarke, Laura; Coupland, Paul; van der Ent, Martijn; Erber, Wendy N; Jansen, Joop H; Favier, Rémi; Fenech, Matthew E; Foad, Nicola; Freson, Kathleen; van Geet, Chris; Gomez, Keith; Guigo, Roderic; Hampshire, Daniel; Kelly, Anne M; Kerstens, Hindrik H D; Kooner, Jaspal S; Laffan, Michael; Lentaigne, Claire; Labalette, Charlotte; Martin, Tiphaine; Meacham, Stuart; Mumford, Andrew; Nürnberg, Sylvia; Palumbo, Emilio; van der Reijden, Bert A; Richardson, David; Sammut, Stephen J; Slodkowicz, Greg; Tamuri, Asif U; Vasquez, Louella; Voss, Katrin; Watt, Stephen; Westbury, Sarah; Flicek, Paul; Loos, Remco; Goldman, Nick; Bertone, Paul; Read, Randy J; Richardson, Sylvia; Cvejic, Ana; Soranzo, Nicole; Ouwehand, Willem H; Stunnenberg, Hendrik G; Frontini, Mattia; Rendon, Augusto

    2014-09-26

    Blood cells derive from hematopoietic stem cells through stepwise fating events. To characterize gene expression programs driving lineage choice, we sequenced RNA from eight primary human hematopoietic progenitor populations representing the major myeloid commitment stages and the main lymphoid stage. We identified extensive cell type-specific expression changes: 6711 genes and 10,724 transcripts, enriched in non-protein-coding elements at early stages of differentiation. In addition, we found 7881 novel splice junctions and 2301 differentially used alternative splicing events, enriched in genes involved in regulatory processes. We demonstrated experimentally cell-specific isoform usage, identifying nuclear factor I/B (NFIB) as a regulator of megakaryocyte maturation-the platelet precursor. Our data highlight the complexity of fating events in closely related progenitor populations, the understanding of which is essential for the advancement of transplantation and regenerative medicine. Copyright © 2014, American Association for the Advancement of Science.

  9. Imparting regenerative capacity to limbs by progenitor cell transplantation

    PubMed Central

    Lin, Gufa; Chen, Ying; Slack, Jonathan M.W.

    2012-01-01

    Summary The frog Xenopus can normally regenerate its limbs at early developmental stages but loses the ability during metamorphosis. This behavior provides a potential gain-of-function model for measures that can enhance limb regeneration. Here we show that frog limbs can be caused to form multidigit regenerates after receiving transplants of larval limb progenitor cells. It is necessary to activate Wnt/β -catenin signaling in the cells, and to add Sonic hedgehog, FGF10 and thymosin β4. These factors promote survival and growth of the grafted cells and also provide pattern information. The eventual regenerates are not composed solely of donor tissue; the host cells also make a substantial contribution despite their lack of regeneration-competence. Cells from adult frog legs or from regenerating tadpole tails do not promote limb regeneration, demonstrating the necessity for limb progenitor cells. These findings have obvious implications for the development of a technology to promote limb regeneration in mammals. PMID:23273877

  10. Nonlinear Y-Like Receptive Fields in the Early Visual Cortex: An Intermediate Stage for Building Cue-Invariant Receptive Fields from Subcortical Y Cells.

    PubMed

    Gharat, Amol; Baker, Curtis L

    2017-01-25

    Many of the neurons in early visual cortex are selective for the orientation of boundaries defined by first-order cues (luminance) as well as second-order cues (contrast, texture). The neural circuit mechanism underlying this selectivity is still unclear, but some studies have proposed that it emerges from spatial nonlinearities of subcortical Y cells. To understand how inputs from the Y-cell pathway might be pooled to generate cue-invariant receptive fields, we recorded visual responses from single neurons in cat Area 18 using linear multielectrode arrays. We measured responses to drifting and contrast-reversing luminance gratings as well as contrast modulation gratings. We found that a large fraction of these neurons have nonoriented responses to gratings, similar to those of subcortical Y cells: they respond at the second harmonic (F2) to high-spatial frequency contrast-reversing gratings and at the first harmonic (F1) to low-spatial frequency drifting gratings ("Y-cell signature"). For a given neuron, spatial frequency tuning for linear (F1) and nonlinear (F2) responses is quite distinct, similar to orientation-selective cue-invariant neurons. Also, these neurons respond to contrast modulation gratings with selectivity for the carrier (texture) spatial frequency and, in some cases, orientation. Their receptive field properties suggest that they could serve as building blocks for orientation-selective cue-invariant neurons. We propose a circuit model that combines ON- and OFF-center cortical Y-like cells in an unbalanced push-pull manner to generate orientation-selective, cue-invariant receptive fields. A significant fraction of neurons in early visual cortex have specialized receptive fields that allow them to selectively respond to the orientation of boundaries that are invariant to the cue (luminance, contrast, texture, motion) that defines them. However, the neural mechanism to construct such versatile receptive fields remains unclear. Using multielectrode

  11. Detection of early and single infections of Schistosoma japonicum in the intermediate host snail, Oncomelania hupensis, by PCR and loop-mediated isothermal amplification (LAMP) assay.

    PubMed

    Kumagai, Takashi; Furushima-Shimogawara, Rieko; Ohmae, Hiroshi; Wang, Tian-Ping; Lu, Shaohong; Chen, Rui; Wen, Liyong; Ohta, Nobuo

    2010-09-01

    Polymerase chain reaction (PCR) with the specific primer set amplifying 28S ribosomal DNA (rDNA) of Schistosoma japonicum was able to detect genomic DNA of S. japonicum, but not S. mansoni, at 100 fg. This procedure enabled us to detect the DNA from a single miracidium and a snail infected with one miracidium at just 1 day after infection. We compared these results with those from loop-mediated isothermal amplification (LAMP) targeting 28S rDNA and found similar results. The LAMP could amplify the specific DNA from a group of 100 normal snails mixed with one infected snail A PCR screening of infected snails from endemic regions in Anhui Province revealed schistosomal DNA even in snails found negative by microscopy. PCR and LAMP show promise for monitoring the early infection rate in snails, and they may be useful for predicting the risk of infection in the endemic places.

  12. Functional Traits Differ between Cereal Crop Progenitors and Other Wild Grasses Gathered in the Neolithic Fertile Crescent

    PubMed Central

    Cunniff, Jennifer; Wilkinson, Sarah; Charles, Michael; Jones, Glynis; Rees, Mark; Osborne, Colin P.

    2014-01-01

    The reasons why some plant species were selected as crops and others were abandoned during the Neolithic emergence of agriculture are poorly understood. We tested the hypothesis that the traits of Fertile Crescent crop progenitors were advantageous in the fertile, disturbed habitats surrounding early settlements and in cultivated fields. We screened functional traits related to competition and disturbance in a group of grass species that were increasingly exploited by early plant gatherers, and that were later domesticated (crop progenitors); and in a set of grass species for which there is archaeological evidence of gathering, but which were never domesticated (wild species). We hypothesised that crop progenitors would have greater seed mass, growth rate, height and yield than wild species, as these traits are indicative of greater competitive ability, and that crop progenitors would be more resilient to defoliation. Our results show that crop progenitors have larger seed mass than wild species, germinate faster and have greater seedling size. Increased seed size is weakly but positively correlated with a higher growth rate, which is primarily driven by greater biomass assimilation per unit leaf area. Crop progenitors also tend to have a taller stature, greater grain yield and higher resilience to defoliation. Collectively, the data are consistent with the hypothesis that adaptations to competition and disturbance gave crop progenitors a selective advantage in the areas surrounding early human settlements and in cultivated environments, leading to their adoption as crops through processes of unconscious selection. PMID:24489941

  13. Narrowing the gap: early and intermediate outcomes after percutaneous coronary intervention and coronary artery bypass graft procedures in California, 1997 to 2006.

    PubMed

    Carey, Joseph S; Danielsen, Beate; Milliken, Jeffrey; Li, Zhongmin; Stabile, Bruce E

    2009-11-01

    Percutaneous coronary intervention is increasingly used to treat multivessel coronary artery disease. Coronary artery bypass graft procedures have decreased, and as a result, percutaneous coronary intervention has increased. The overall impact of this treatment shift is uncertain. We examined the in-hospital mortality and complication rates for these procedures in California using a combined risk model. The confidential dataset of the Office of Statewide Health Planning and Development patient discharge database was queried for 1997 to 2006. A risk model was developed using International Classification of Diseases, Ninth Revision, Clinical Modification procedures and diagnostic codes from the combined pool of isolated coronary artery bypass graft and percutaneous coronary intervention procedures performed during 2005 and 2006. In-hospital mortality was corrected for "same-day" transfers to another health care institution. Early failure rate was defined as in-hospital mortality rate plus reintervention for another percutaneous coronary intervention or cardiac surgery procedure within 90 days. Coronary artery bypass graft volume decreased from 28,495 (1997) to 15,520 (2006), whereas percutaneous coronary intervention volume increased from 38,098 to 53,703. Risk-adjusted mortality rate decreased from 4.7% to 2.1% for coronary artery bypass graft procedures and from 3.4% to 1.9% for percutaneous coronary intervention. Expected mortality rate increased for both procedures. Early failure rate decreased from 13.1% to 8.0% for percutaneous coronary intervention and from 6.5% to 5.4% for coronary artery bypass graft. For the years 2004 and 2005, the risk of recurrent myocardial infarction or need for coronary artery bypass graft during the first postoperative year was 12% for percutaneous coronary intervention and 6% for coronary artery bypass grafts. This study shows that as volume shifted from coronary artery bypass grafts to percutaneous coronary intervention, expected

  14. Derivation and characterization of hepatic progenitor cells from human embryonic stem cells.

    PubMed

    Zhao, Dongxin; Chen, Song; Cai, Jun; Guo, Yushan; Song, Zhihua; Che, Jie; Liu, Chun; Wu, Chen; Ding, Mingxiao; Deng, Hongkui

    2009-07-31

    The derivation of hepatic progenitor cells from human embryonic stem (hES) cells is of value both in the study of early human liver organogenesis and in the creation of an unlimited source of donor cells for hepatocyte transplantation therapy. Here, we report for the first time the generation of hepatic progenitor cells derived from hES cells. Hepatic endoderm cells were generated by activating FGF and BMP pathways and were then purified by fluorescence activated cell sorting using a newly identified surface marker, N-cadherin. After co-culture with STO feeder cells, these purified hepatic endoderm cells yielded hepatic progenitor colonies, which possessed the proliferation potential to be cultured for an extended period of more than 100 days. With extensive expansion, they co-expressed the hepatic marker AFP and the biliary lineage marker KRT7 and maintained bipotential differentiation capacity. They were able to differentiate into hepatocyte-like cells, which expressed ALB and AAT, and into cholangiocyte-like cells, which formed duct-like cyst structures, expressed KRT19 and KRT7, and acquired epithelial polarity. In conclusion, this is the first report of the generation of proliferative and bipotential hepatic progenitor cells from hES cells. These hES cell-derived hepatic progenitor cells could be effectively used as an in vitro model for studying the mechanisms of hepatic stem/progenitor cell origin, self-renewal and differentiation.

  15. Mutually exclusive signaling signatures define the hepatic and pancreatic progenitor cell lineage divergence

    PubMed Central

    Rodríguez-Seguel, Elisa; Mah, Nancy; Naumann, Heike; Pongrac, Igor M.; Cerdá-Esteban, Nuria; Fontaine, Jean-Fred; Wang, Yongbo; Chen, Wei; Andrade-Navarro, Miguel A.; Spagnoli, Francesca M.

    2013-01-01

    Understanding how distinct cell types arise from multipotent progenitor cells is a major quest in stem cell biology. The liver and pancreas share many aspects of their early development and possibly originate from a common progenitor. However, how liver and pancreas cells diverge from a common endoderm progenitor population and adopt specific fates remains elusive. Using RNA sequencing (RNA-seq), we defined the molecular identity of liver and pancreas progenitors that were isolated from the mouse embryo at two time points, spanning the period when the lineage decision is made. The integration of temporal and spatial gene expression profiles unveiled mutually exclusive signaling signatures in hepatic and pancreatic progenitors. Importantly, we identified the noncanonical Wnt pathway as a potential developmental regulator of this fate decision and capable of inducing the pancreas program in endoderm and liver cells. Our study offers an unprecedented view of gene expression programs in liver and pancreas progenitors and forms the basis for formulating lineage-reprogramming strategies to convert adult hepatic cells into pancreatic cells. PMID:24013505

  16. Temporally Distinct Six2-Positive Second Heart Field Progenitors Regulate Mammalian Heart Development and Disease.

    PubMed

    Zhou, Zhengfang; Wang, Jingying; Guo, Chaoshe; Chang, Weiting; Zhuang, Jian; Zhu, Ping; Li, Xue

    2017-01-24

    The embryonic process of forming a complex structure such as the heart remains poorly understood. Here, we show that Six2 marks a dynamic subset of second heart field progenitors. Six2-positive (Six2 + ) progenitors are rapidly recruited and assigned, and their descendants are allocated successively to regions of the heart from the right ventricle (RV) to the pulmonary trunk. Global ablation of Six2 + progenitors resulted in RV hypoplasia and pulmonary atresia. An early stage-specific ablation of a small subset of Six2 + progenitors did not cause any apparent structural defect at birth but rather resulted in adult-onset cardiac hypertrophy and dysfunction. Furthermore, Six2 expression depends in part on Shh signaling, and Shh deletion resulted in severe deficiency of Six2 + progenitors. Collectively, these findings unveil the chronological features of cardiogenesis, in which the mammalian heart is built sequentially by temporally distinct populations of cardiac progenitors, and provide insights into late-onset congenital heart disease. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  17. APC sets the Wnt tone necessary for cerebral cortical progenitor development.

    PubMed

    Nakagawa, Naoki; Li, Jingjun; Yabuno-Nakagawa, Keiko; Eom, Tae-Yeon; Cowles, Martis; Mapp, Tavien; Taylor, Robin; Anton, E S

    2017-08-15

    Adenomatous polyposis coli (APC) regulates the activity of β-catenin, an integral component of Wnt signaling. However, the selective role of the APC-β-catenin pathway in cerebral cortical development is unknown. Here we genetically dissected the relative contributions of APC-regulated β-catenin signaling in cortical progenitor development, a necessary early step in cerebral cortical formation. Radial progenitor-specific inactivation of the APC-β-catenin pathway indicates that the maintenance of appropriate β-catenin-mediated Wnt tone is necessary for the orderly differentiation of cortical progenitors and the resultant formation of the cerebral cortex. APC deletion deregulates β-catenin, leads to high Wnt tone, and disrupts Notch1 signaling and primary cilium maintenance necessary for radial progenitor functions. β-Catenin deregulation directly disrupts cilium maintenance and signaling via Tulp3, essential for intraflagellar transport of ciliary signaling receptors. Surprisingly, deletion of β-catenin or inhibition of β-catenin activity in APC-null progenitors rescues the APC-null phenotype. These results reveal that APC-regulated β-catenin activity in cortical progenitors sets the appropriate Wnt tone necessary for normal cerebral cortical development. © 2017 Nakagawa et al.; Published by Cold Spring Harbor Laboratory Press.

  18. APC sets the Wnt tone necessary for cerebral cortical progenitor development

    PubMed Central

    Nakagawa, Naoki; Li, Jingjun; Yabuno-Nakagawa, Keiko; Eom, Tae-Yeon; Cowles, Martis; Mapp, Tavien; Taylor, Robin; Anton, E.S.

    2017-01-01

    Adenomatous polyposis coli (APC) regulates the activity of β-catenin, an integral component of Wnt signaling. However, the selective role of the APC–β-catenin pathway in cerebral cortical development is unknown. Here we genetically dissected the relative contributions of APC-regulated β-catenin signaling in cortical progenitor development, a necessary early step in cerebral cortical formation. Radial progenitor-specific inactivation of the APC–β-catenin pathway indicates that the maintenance of appropriate β-catenin-mediated Wnt tone is necessary for the orderly differentiation of cortical progenitors and the resultant formation of the cerebral cortex. APC deletion deregulates β-catenin, leads to high Wnt tone, and disrupts Notch1 signaling and primary cilium maintenance necessary for radial progenitor functions. β-Catenin deregulation directly disrupts cilium maintenance and signaling via Tulp3, essential for intraflagellar transport of ciliary signaling receptors. Surprisingly, deletion of β-catenin or inhibition of β-catenin activity in APC-null progenitors rescues the APC-null phenotype. These results reveal that APC-regulated β-catenin activity in cortical progenitors sets the appropriate Wnt tone necessary for normal cerebral cortical development. PMID:28916710

  19. Planck intermediate results. VII. Statistical properties of infrared and radio extragalactic sources from the Planck Early Release Compact Source Catalogue at frequencies between 100 and 857 GHz

    NASA Astrophysics Data System (ADS)

    Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Argüeso, F.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Balbi, A.; Banday, A. J.; Barreiro, R. B.; Battaner, E.; Benabed, K.; Benoît, A.; Bernard, J.-P.; Bersanelli, M.; Bethermin, M.; Bhatia, R.; Bonaldi, A.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Burigana, C.; Cabella, P.; Cardoso, J.-F.; Catalano, A.; Cayón, L.; Chamballu, A.; Chary, R.-R.; Chen, X.; Chiang, L.-Y.; Christensen, P. R.; Clements, D. L.; Colafrancesco, S.; Colombi, S.; Colombo, L. P. L.; Coulais, A.; Crill, B. P.; Cuttaia, F.; Danese, L.; Davis, R. J.; de Bernardis, P.; de Gasperis, G.; de Zotti, G.; Delabrouille, J.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Dörl, U.; Douspis, M.; Dupac, X.; Efstathiou, G.; Enßlin, T. A.; Eriksen, H. K.; Finelli, F.; Forni, O.; Fosalba, P.; Frailis, M.; Franceschi, E.; Galeotta, S.; Ganga, K.; Giard, M.; Giardino, G.; Giraud-Héraud, Y.; González-Nuevo, J.; Górski, K. M.; Gregorio, A.; Gruppuso, A.; Hansen, F. K.; Harrison, D.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Jaffe, T. R.; Jaffe, A. H.; Jagemann, T.; Jones, W. C.; Juvela, M.; Keihänen, E.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Knox, L.; Kunz, M.; Kurinsky, N.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Lawrence, C. R.; Leonardi, R.; Lilje, P. B.; López-Caniego, M.; Macías-Pérez, J. F.; Maino, D.; Mandolesi, N.; Maris, M.; Marshall, D. J.; Martínez-González, E.; Masi, S.; Massardi, M.; Matarrese, S.; Mazzotta, P.; Melchiorri, A.; Mendes, L.; Mennella, A.; Mitra, S.; Miville-Deschènes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; Osborne, S.; Pajot, F.; Paladini, R.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G. W.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Reach, W. T.; Rebolo, R.; Reinecke, M.; Renault, C.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rowan-Robinson, M.; Rubiño-Martín, J. A.; Rusholme, B.; Sajina, A.; Sandri, M.; Savini, G.; Scott, D.; Smoot, G. F.; Starck, J.-L.; Sudiwala, R.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Türler, M.; Valenziano, L.; Van Tent, B.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L. A.; Wandelt, B. D.; White, M.; Yvon, D.; Zacchei, A.; Zonca, A.

    2013-02-01

    We make use of the Planck all-sky survey to derive number counts and spectral indices of extragalactic sources - infrared and radio sources - from the Planck Early Release Compact Source Catalogue (ERCSC) at 100 to 857 GHz (3 mm to 350 μm). Three zones (deep, medium and shallow) of approximately homogeneous coverage are used to permit a clean and controlled correction for incompleteness, which was explicitly not done for the ERCSC, as it was aimed at providing lists of sources to be followed up. Our sample, prior to the 80% completeness cut, contains between 217 sources at 100 GHz and 1058 sources at 857 GHz over about 12 800 to 16 550 deg2 (31 to 40% of the sky). After the 80% completeness cut, between 122 and 452 and sources remain, with flux densities above 0.3 and 1.9 Jy at 100 and 857 GHz. The sample so defined can be used for statistical analysis. Using the multi-frequency coverage of the Planck High Frequency Instrument, all the sources have been classified as either dust-dominated (infrared galaxies) or synchrotron-dominated (radio galaxies) on the basis of their spectral energy distributions (SED). Our sample is thus complete, flux-limited and color-selected to differentiate between the two populations. We find an approximately equal number of synchrotron and dusty sources between 217 and 353 GHz; at 353 GHz or higher (or 217 GHz and lower) frequencies, the number is dominated by dusty (synchrotron) sources, as expected. For most of the sources, the spectral indices are also derived. We provide for the first time counts of bright sources from 353 to 857 GHz and the contributions from dusty and synchrotron sources at all HFI frequencies in the key spectral range where these spectra are crossing. The observed counts are in the Euclidean regime. The number counts are compared to previously published data (from earlier Planck results, Herschel, BLAST, SCUBA, LABOCA, SPT, and ACT) and models taking into account both radio or infrared galaxies, and covering a

  20. Characterization of Reversibly Immortalized Calvarial Mesenchymal Progenitor Cells.

    PubMed

    Shenaq, Deana S; Teven, Chad M; Seitz, Iris A; Rastegar, Farbod; Greives, Matthew R; He, Tong-Chuan; Reid, Russell R

    2015-06-01

    Bone morphogenetic proteins (BMPs) play a sentinel role in osteoblastic differentiation, and their implementation into clinical practice can revolutionize cranial reconstruction. Preliminary data suggest a therapeutic role of adenoviral gene delivery of BMPs in murine calvarial defect healing. Poor transgene expression inherent in direct adenoviral therapy prompted investigation of cell-based strategies. To isolate and immortalize calvarial cells as a potential progenitor source for osseous tissue engineering. Cells were isolated from murine skulls, cultured, and transduced with a retroviral vector bearing the loxP-flanked SV40 large T antigen. Immortalized calvarial cells (iCALs) were evaluated via light microscopy, immunohistochemistry, and flow cytometry to determine whether the immortalization process altered cell morphology or progenitor cell profile. Immortalized calvarial cells were then infected with adenoviral vectors encoding BMP-2 or GFP and assessed for early and late stages of osteogenic differentiation. Immortalization of calvarial cells did not alter cell morphology as demonstrated by phase contrast microscopy. Mesenchymal progenitor cell markers CD166, CD73, CD44, and CD105 were detected at varying levels in both primary cells and iCALs. Significant elevations in alkaline phosphatase activity, osteocalcin mRNA transcription, and matrix mineralization were detected in BMP-2 treated iCALs compared with GFP-treated cells. Gross and histological analyses revealed ectopic bone production from treated cells compared with controls in an in vivo stem cell implantation assay. We have established an immortalized osteoprogenitor cell line from juvenile calvarial cells that retain a progenitor cell phenotype and can successfully undergo osteogenic differentiation upon BMP-2 stimulation. These cells provide a valuable platform to investigate the molecular mechanisms underlying intramembranous bone formation and to screen for factors/small molecules that can

  1. Efficacy and Safety of Human Retinal Progenitor Cells

    PubMed Central

    Semo, Ma'ayan; Haamedi, Nasrin; Stevanato, Lara; Carter, David; Brooke, Gary; Young, Michael; Coffey, Peter; Sinden, John; Patel, Sara; Vugler, Anthony

    2016-01-01

    Purpose We assessed the long-term efficacy and safety of human retinal progenitor cells (hRPC) using established rodent models. Methods Efficacy of hRPC was tested initially in Royal College of Surgeons (RCS) dystrophic rats immunosuppressed with cyclosporine/dexamethasone. Due to adverse effects of dexamethasone, this drug was omitted from a subsequent dose-ranging study, where different hRPC doses were tested for their ability to preserve visual function (measured by optokinetic head tracking) and retinal structure in RCS rats at 3 to 6 months after grafting. Safety of hRPC was assessed by subretinal transplantation into wild type (WT) rats and NIH-III nude mice, with analysis at 3 to 6 and 9 months after grafting, respectively. Results The optimal dose of hRPC for preserving visual function/retinal structure in dystrophic rats was 50,000 to 100,000 cells. Human retinal progenitor cells integrated/survived in dystrophic and WT rat retina up to 6 months after grafting and expressed nestin, vimentin, GFAP, and βIII tubulin. Vision and retinal structure remained normal in WT rats injected with hRPC and there was no evidence of tumors. A comparison between dexamethasone-treated and untreated dystrophic rats at 3 months after grafting revealed an unexpected reduction in the baseline visual acuity of dexamethasone-treated animals. Conclusions Human retinal progenitor cells appear safe and efficacious in the preclinical models used here. Translational Relevance Human retinal progenitor cells could be deployed during early stages of retinal degeneration or in regions of intact retina, without adverse effects on visual function. The ability of dexamethasone to reduce baseline visual acuity in RCS dystrophic rats has important implications for the interpretation of preclinical and clinical cell transplant studies. PMID:27486556

  2. Red supergiants as supernova progenitors

    NASA Astrophysics Data System (ADS)

    Davies, Ben

    2017-09-01

    It is now well-established from pre-explosion imaging that red supergiants (RSGs) are the direct progenitors of Type-IIP supernovae. These images have been used to infer the physical properties of the exploding stars, yielding some surprising results. In particular, the differences between the observed and predicted mass spectrum has provided a challenge to our view of stellar evolutionary theory. However, turning what is typically a small number of pre-explosion photometric points into the physical quantities of stellar luminosity and mass requires a number of assumptions about the spectral appearance of RSGs, as well as their evolution in the last few years of life. Here I will review what we know about RSGs, with a few recent updates on how they look and how their appearance changes as they approach supernova. This article is part of the themed issue 'Bridging the gap: from massive stars to supernovae'.

  3. Red supergiants as supernova progenitors.

    PubMed

    Davies, Ben

    2017-10-28

    It is now well-established from pre-explosion imaging that red supergiants (RSGs) are the direct progenitors of Type-IIP supernovae. These images have been used to infer the physical properties of the exploding stars, yielding some surprising results. In particular, the differences between the observed and predicted mass spectrum has provided a challenge to our view of stellar evolutionary theory. However, turning what is typically a small number of pre-explosion photometric points into the physical quantities of stellar luminosity and mass requires a number of assumptions about the spectral appearance of RSGs, as well as their evolution in the last few years of life. Here I will review what we know about RSGs, with a few recent updates on how they look and how their appearance changes as they approach supernova.This article is part of the themed issue 'Bridging the gap: from massive stars to supernovae'. © 2017 The Author(s).

  4. Fibroblast growth factor receptor-Frs2α signaling is critical for nephron progenitors.

    PubMed

    Di Giovanni, Valeria; Walker, Kenneth A; Bushnell, Daniel; Schaefer, Caitlin; Sims-Lucas, Sunder; Puri, Pawan; Bates, Carlton M

    2015-04-01

    Previous studies using transgenic Pax3cre mice have revealed roles for fibroblast growth factor receptors (Fgfrs) and Fgfr substrate 2α (Frs2α) signaling in early metanephric mesenchyme patterning and in ureteric morphogenesis. The role of Fgfr/Frs2α signaling in nephron progenitors is unknown. Thus, we generated mouse models using BAC transgenic Six2EGFPcre (Six2cre) mediated deletion of Fgfrs and/or Frs2α in nephron progenitors. Six2cre mediated deletion of Fgfr1 or Fgfr2 alone led to no obvious kidney defects. Six2creFgfr1(flox/flox)Fgfr2(flox/flox) (Fgfr1/2(NP-/-)) mice generate a discernable kidney; however, they develop nephron progenitor depletion starting at embryonic day 12.5 (E12.5) and later demonstrate severe cystic dysplasia. To determine the role of Frs2α signaling downstream of Fgfr2 in Fgfr1/2(NP-/-) mice, we generated Six2cre(,)Fgfr1(flox/flox)Fgfr2(LR/LR) (Fgfr1(NP-/-)Fgfr2(LR/LR)) mice that have point mutations in the Frs2α binding site of Fgfr2. Like Fgfr1/2(NP-/-) mice, Fgfr1(NP-/-)Fgfr2(LR/LR) develop nephron progenitor depletion, but it does not start until E14.5 and older mice have less severe cystic dysplasia than Fgfr1/2(NP-/-) To determine the role of Frs2α alone in nephron progenitors, we generated Six2creFrs2'A(flox/flox) (Frs2a(NP-/-)) mice. Frs2a(NP-/-)mice also develop nephron progenitor depletion and renal cysts, although these occurred later and were less severe than in the other Six2cre mutant mice. The nephron progenitor loss in all Six2cre mutant lines was associated with decreased Cited1 expression and increased apoptosis versus controls. FAC-sorted nephron progenitors in Six2cre Frs2'A(flox/flox) mice demonstrated evidence of increased Notch activity versus controls, which likely drives the progenitor defects. Thus, Fgfr1 and Fgfr2 have synergistic roles in maintaining nephron progenitors; furthermore, Fgfr signaling in nephron progenitors appears to be mediated predominantly by Frs2α. Copyright © 2015 Elsevier Inc

  5. Human hematopoietic progenitors express erythropoietin.

    PubMed

    Stopka, T; Zivny, J H; Stopkova, P; Prchal, J F; Prchal, J T

    1998-05-15

    Erythropoietin (EPO) is a factor essential for erythroid cell proliferation, differentiation, and survival. The production of EPO by the kidneys in response to hypoxia and anemia is well documented. To determine whether EPO is also produced by hematopoietic cells, we analyzed the expression of EPO in normal human hematopoietic progenitors and in their progeny. Undifferentiated CD34(+)lin- hematopoietic progenitors do not have detectable EPO mRNA. Differentiating CD34(+) cells that are stimulated with recombinant human EPO in serum-free liquid cultures express both EPO and EPO receptor (EPOR). Because CD34(+) cells represent a heterogeneous cell population, we analyzed individual burst-forming units-erythroid (BFU-E) and nonerythroid colony-forming unit-granulocyte-macrophage colonies for EPO mRNA. Only BFU-E colonies were positive for EPO mRNA. Lysates from pooled BFU-E colonies stained positively for EPO by immunoblotting. To further confirm the intrinsic nature of erythroid EPO, we replaced extrinsic EPO in erythroid colony cultures with EPO-mimicking peptide (EMP). We show EPO expression in the EMP-stimulated BFU-Es at both mRNA and protein levels. Stimulation of bone marrow mononuclear cells (BMMCs) with EMP upregulated EPO expression. Furthermore, we found EPO and EPOR mRNAs as well as EPO protein in K562 cells, a human erythroleukemia cell line. Stimulation of K562 cells with EMP upregulated EPO expression. We suggest that EPO of erythroid origin may have a role in the regulation of erythropoiesis.

  6. The progenitors of stripped-envelope supernovae

    NASA Astrophysics Data System (ADS)

    Elias-Rosa, N.

    2013-05-01

    The type Ib/c SNe are those explosions which come from massive star populations, but lack hydrogen and helium. These have been proposed to originate in the explosions of massive Wolf-Rayet stars, and we should easily be able to detect the very luminous, young progenitors if they exist. However, there has not been any detection of progenitors so far. I present the study of two extinguished Type Ic SNe 2003jg and 2004cc. In both cases there is no clear evidence of a direct detection of their progenitors in deep pre-explosion images. Upper limits derived by inserting artificial stars of known brightness at random positions around the progenitor positions (M_v>-8.8 and M_v>-9 magnitudes for the progenitors of SN 2003jg and SN 2004cc, respectively) are brighter than those expected for a massive WC (Wolf-Rayet, carbon-rich) or WO (Wolf-Rayet, oxygen-rich) (e.g., approximately between -3 and -6 in the LMC). Therefore, this is perhaps further evidence that the most massive stars may give rise to black-holes forming SNe, or it is an undetected, compact massive star hidden by a thick dust lane. However the extinction toward these SNe is currently one of the largest known. Even if these results do not directly reveal the nature of the type Ic SN progenitors, they can help to characterize the dusty environment which surrounded the progenitor of the stripped-envelope CC-SNe.

  7. The extracellular matrix controls gap junction protein expression and function in postnatal hippocampal neural progenitor cells

    PubMed Central

    Imbeault, Sophie; Gauvin, Lianne G; Toeg, Hadi D; Pettit, Alexandra; Sorbara, Catherine D; Migahed, Lamiaa; DesRoches, Rebecca; Menzies, A Sheila; Nishii, Kiyomasa; Paul, David L; Simon, Alexander M; Bennett, Steffany AL

    2009-01-01

    Background Gap junction protein and extracellular matrix signalling systems act in concert to influence developmental specification of neural stem and progenitor cells. It is not known how these two signalling systems interact. Here, we examined the role of ECM components in regulating connexin expression and function in postnatal hippocampal progenitor cells. Results We found that Cx26, Cx29, Cx30, Cx37, Cx40, Cx43, Cx45, and Cx47 mRNA and protein but only Cx32 and Cx36 mRNA are detected in distinct neural progenitor cell populations cultured in the absence of exogenous ECM. Multipotential Type 1 cells express Cx26, Cx30, and Cx43 protein. Their Type 2a progeny but not Type 2b and 3 neuronally committed progenitor cells additionally express Cx37, Cx40, and Cx45. Cx29 and Cx47 protein is detected in early oligodendrocyte progenitors and mature oligodendrocytes respectively. Engagement with a laminin substrate markedly increases Cx26 protein expression, decreases Cx40, Cx43, Cx45, and Cx47 protein expression, and alters subcellular localization of Cx30. These changes are associated with decreased neurogenesis. Further, laminin elicits the appearance of Cx32 protein in early oligodendrocyte progenitors and Cx36 protein in immature neurons. These changes impact upon functional connexin-mediated hemichannel activity but not gap junctional intercellular communication. Conclusion Together, these findings demonstrate a new role for extracellular matrix-cell interaction, specifically laminin, in the regulation of intrinsic connexin expression and function in postnatal neural progenitor cells. PMID:19236721

  8. Differential Subcellular Localization of the Glucocorticoid Receptor in Distinct Neural Stem and Progenitor Populations of the Mouse Telencephalon In Vivo

    PubMed Central

    Tsiarli, Maria A.; Monaghan, A. Paula; DeFranco, Donald B.

    2013-01-01

    Glucocorticoids are given to pregnant women at risk for premature delivery to promote lung maturation. Despite reports of detrimental effects of glucocorticoids on telencephalic neural stem/progenitor cells (NSPCs), the regional and cellular expression of the glucocorticoid receptor (GR) in various NSPC populations in the intact brain has not been thoroughly assessed. Therefore in this study we performed a detailed analysis of GR protein expression in the developing mouse ventral and dorsal telencephalon in vivo. At embryonic day 11.5 (E11.5), the majority of Pax6-positive radial glial cells (RGCs) and Tbr2-positive intermediate progenitor cells (IPCs) expressed nuclear GR, while a small number of RGCs on the apical ventricular zone (aVZ), expressed cytoplasmic GR. However, on E13.5, the latter population of RGCs increased in size, whereas abventricular NSPCs and especially neurons of the cortical plate, expressed nuclear GR. In IPCs, GR was always nuclear. A similar expression profile was observed throughout the ventral telencephalon, hippocampus and olfactory bulb, with NSPCs of the aVZ primarily expressing cytoplasmic GR, while abventricular NSPCs and mature cells primarily expressed nuclear GR. Close to birth, nuclear GR accumulated within specific cortical areas such as layer V, the subplate and CA1 area of the hippocampus. In summary, our data show that GR protein is present in early NSPCs of the dorsal and ventral telencephalon at E11.5 and primarily occupies the nucleus. Moreover, our study suggests that the subcellular localization of the receptor may be subjected to region and neurodevelopmental stage-specific regulation. PMID:23751362

  9. Differential subcellular localization of the glucocorticoid receptor in distinct neural stem and progenitor populations of the mouse telencephalon in vivo.

    PubMed

    Tsiarli, Maria A; Paula Monaghan, A; Defranco, Donald B

    2013-07-26

    Glucocorticoids are given to pregnant women at risk for premature delivery to promote lung maturation. Despite reports of detrimental effects of glucocorticoids on telencephalic neural stem/progenitor cells (NSPCs), the regional and cellular expressions of the glucocorticoid receptor (GR) in various NSPC populations in the intact brain have not been thoroughly assessed. Therefore in this study we performed a detailed analysis of GR protein expression in the developing mouse ventral and dorsal telencephalon in vivo. At embryonic day 11.5 (E11.5), the majority of Pax6-positive radial glial cells (RGCs) and Tbr2-positive intermediate progenitor cells (IPCs) expressed nuclear GR, while a small number of RGCs on the apical ventricular zone (aVZ), expressed cytoplasmic GR. However, on E13.5, the latter population of RGCs increased in size, whereas abventricular NSPCs and especially neurons of the cortical plate, expressed nuclear GR. In IPCs, GR was always nuclear. A similar expression profile was observed throughout the ventral telencephalon, hippocampus and olfactory bulb, with NSPCs of the aVZ primarily expressing cytoplasmic GR, while abventricular NSPCs and mature cells primarily expressed nuclear GR. Close to birth, nuclear GR accumulated within specific cortical areas such as layer V, the subplate and CA1 area of the hippocampus. In summary, our data show that GR protein is present in early NSPCs of the dorsal and ventral telencephalon at E11.5 and primarily occupies the nucleus. Moreover, our study suggests that the subcellular localization of the receptor may be subjected to region and neurodevelopmental stage-specific regulation. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Identification, characterization and isolation of a common progenitor for osteoclasts, macrophages and dendritic cells from murine bone marrow and periphery

    PubMed Central

    Jacome-Galarza, Christian E.; Lee, Sun-Kyeong; Lorenzo, Joseph A.; LeonardoAguila, Hector

    2012-01-01

    Osteoclasts are specialized bone resorbing cells that derive from monocyte precursors. We have identified three populations of cells with high osteoclastogenic potential in murine bone marrow, which expressed the phenotype: B220−CD3−CD11b−/low CD115+ and either CD117hi, CD117intermediate or CD117low. We have evaluated these populations for their ability to also generate macrophages and dendritic cells. At a single cell level, the population expressing higher CD117 levels was able to generate bone-resorbing osteoclasts, phagocytic macrophages and antigen-presenting dendritic cells in vitro with efficiencies of over 90 percent, indicating that there exists a common developmental pathway for these cell types. Cells with osteoclastogenic potential also exist in blood and peripheral hematopoietic organs. Their functional meaning and/or their relationship with bone marrow progenitors is not well established. Hence, we characterized murine peripheral cell populations for their ability to form osteoclasts, macrophages and dendritic cells in vitro. The spleen and peripheral blood monocyte progenitors share phenotypic markers with bone marrow progenitors, but differ in their expression of CD11b, which was low in bone marrow but high in periphery. We propose that circulating monocyte progenitors are derived from a common bone marrow osteoclasts/macrophage/dendritic cell progenitor (OcMDC), which we have now characterized at a clonal level. However, the lineage relationship between the bone marrow and peripheral monocyte progenitors has yet to be defined. PMID:23165930

  11. Eya1 Interacts with Six2 and Myc to Regulate Expansion of the Nephron Progenitor Pool during Nephrogenesis

    PubMed Central

    Xu, Jinshu; Wong, Elaine Y.M.; Cheng, Chunming; Li, Jun; Sharkar, Mohammad T.K.; Xu, Chelsea Y.; Chen, Binglai; Sun, Jianbo; Jing, Dongzhu; Xu, Pin-Xian

    2014-01-01

    SUMMARY Self-renewal and proliferation of nephron progenitor cells and the decision to initiate nephrogenesis are crucial events directing kidney development. Despite recent advancements in defining lineage and regulators for the progenitors, fundamental questions about mechanisms driving expansion of the progenitors remain unanswered. Here we show that Eya1 interacts with Six2 and Myc to control self-renewing cell activity. Cell fate tracing reveals a developmental restriction of the Eya1+ population within the intermediate mesoderm to nephron-forming cell fates and a common origin shared between caudal mesonephric and metanephric nephrons. Conditional inactivation of Eya1 leads to loss of Six2 expression and premature epithelialization of the progenitors. Six2 mediates translocation of Eya1 to the nucleus, where Eya1 uses its threonine phosphatase activity to control Myc phosphorylation/dephosphorylation and function in the progenitor cells. Our results reveal a functional link between Eya1, Six2, and Myc in driving the expansion and maintenance of the multipotent progenitors during nephrogenesis. PMID:25458011

  12. Eya1 interacts with Six2 and Myc to regulate expansion of the nephron progenitor pool during nephrogenesis.

    PubMed

    Xu, Jinshu; Wong, Elaine Y M; Cheng, Chunming; Li, Jun; Sharkar, Mohammad T K; Xu, Chelsea Y; Chen, Binglai; Sun, Jianbo; Jing, Dongzhu; Xu, Pin-Xian

    2014-11-24

    Self-renewal and proliferation of nephron progenitor cells and the decision to initiate nephrogenesis are crucial events directing kidney development. Despite recent advancements in defining lineage and regulators for the progenitors, fundamental questions about mechanisms driving expansion of the progenitors remain unanswered. Here we show that Eya1 interacts with Six2 and Myc to control self-renewing cell activity. Cell fate tracing reveals a developmental restriction of the Eya1(+) population within the intermediate mesoderm to nephron-forming cell fates and a common origin shared between caudal mesonephric and metanephric nephrons. Conditional inactivation of Eya1 leads to loss of Six2 expression and premature epithelialization of the progenitors. Six2 mediates translocation of Eya1 to the nucleus, where Eya1 uses its threonine phosphatase activity to control Myc phosphorylation/dephosphorylation and function in the progenitor cells. Our results reveal a functional link between Eya1, Six2, and Myc in driving the expansion and maintenance of the multipotent progenitors during nephrogenesis. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Nucleostemin rejuvenates cardiac progenitor cells and antagonizes myocardial aging.

    PubMed

    Hariharan, Nirmala; Quijada, Pearl; Mohsin, Sadia; Joyo, Anya; Samse, Kaitlen; Monsanto, Megan; De La Torre, Andrea; Avitabile, Daniele; Ormachea, Lucia; McGregor, Michael J; Tsai, Emily J; Sussman, Mark A

    2015-01-20

    Functional decline in stem cell-mediated regeneration contributes to aging associated with cellular senescence in c-kit+ cardiac progenitor cells (CPCs). Clinical implementation of CPC-based therapy in elderly patients would benefit tremendously from understanding molecular characteristics of senescence to antagonize aging. Nucleostemin (NS) is a nucleolar protein regulating stem cell proliferation and pluripotency. This study sought to demonstrate that NS preserves characteristics associated with "stemness" in CPCs and antagonizes myocardial senescence and aging. CPCs isolated from human fetal (fetal human cardiac progenitor cell [FhCPC]) and adult failing (adult human cardiac progenitor cell [AhCPC]) hearts, as well as young (young cardiac progenitor cell [YCPC]) and old mice (old cardiac progenitor cell [OCPC]), were studied for senescence characteristics and NS expression. Heterozygous knockout mice with 1 functional allele of NS (NS+/-) were used to demonstrate that NS preserves myocardial structure and function and slows characteristics of aging. NS expression is decreased in AhCPCs relative to FhCPCs, correlating with lowered proliferation potential and shortened telomere length. AhCPC characteristics resemble those of OCPCs, which have a phenotype induced by NS silencing, resulting in cell flattening, senescence, multinucleated cells, decreased S-phase progression, diminished expression of stemness markers, and up-regulation of p53 and p16. CPC senescence resulting from NS loss is partially p53 dependent and is rescued by concurrent silencing of p53. Mechanistically, NS induction correlates with Pim-1 kinase-mediated stabilization of c-Myc. Engineering OCPCs and AhCPCs to overexpress NS decreases senescent and multinucleated cells, restores morphology, and antagonizes senescence, thereby preserving phenotypic properties of "stemness." Early cardiac aging with a decline in cardiac function, an increase in senescence markers p53 and p16, telomere attrition

  14. Observational properties of massive black hole binary progenitors

    NASA Astrophysics Data System (ADS)

    Hainich, R.; Oskinova, L. M.; Shenar, T.; Marchant, P.; Eldridge, J. J.; Sander, A. A. C.; Hamann, W.-R.; Langer, N.; Todt, H.

    2018-01-01

    Context. The first directly detected gravitational waves (GW 150914) were emitted by two coalescing black holes (BHs) with masses of ≈ 36 M⊙ and ≈ 29 M⊙. Several scenarios have been proposed to put this detection into an astrophysical context. The evolution of an isolated massive binary system is among commonly considered models. Aims: Various groups have performed detailed binary-evolution calculations that lead to BH merger events. However, the question remains open as to whether binary systems with the predicted properties really exist. The aim of this paper is to help observers to close this gap by providing spectral characteristics of massive binary BH progenitors during a phase where at least one of the companions is still non-degenerate. Methods: Stellar evolution models predict fundamental stellar parameters. Using these as input for our stellar atmosphere code (Potsdam Wolf-Rayet), we compute a set of models for selected evolutionary stages of massive merging BH progenitors at different metallicities. Results: The synthetic spectra obtained from our atmosphere calculations reveal that progenitors of massive BH merger events start their lives as O2-3V stars that evolve to early-type blue supergiants before they undergo core-collapse during the Wolf-Rayet phase. When the primary has collapsed, the remaining system will appear as a wind-fed high-mass X-ray binary. Based on our atmosphere models, we provide feedback parameters, broad band magnitudes, and spectral templates that should help to identify such binaries in the future. Conclusions: While the predicted parameter space for massive BH binary progenitors is partly realized in nature, none of the known massive binaries match our synthetic spectra of massive BH binary progenitors exactly. Comparisons of empirically determined mass-loss rates with those assumed by evolution calculations reveal significant differences. The consideration of the empirical mass-loss rates in evolution calculations will

  15. Transfection of Murine and Human Hematopoietic Progenitors with Rearranged Immunoglobulin Genes

    DTIC Science & Technology

    1991-01-01

    fluorouracil (SFU) to eliminate most cycling progenitors. Previous studies have shown that 5FU -treatment enriches for one early progenitor with high...Table I shows a time course of SCA-I positive cell expression various times post- 5FU treatment. Table 1 clearly shows that 5FU treatment can increase...the percentage of SCA-l-positive cells to 6-7% by day 7 post- 5FU treatment. The level of SCA-I expression falls to approximately 1% of total nucleated

  16. The Type IIb Supernova 2013df and its Cool Supergiant Progenitor

    NASA Technical Reports Server (NTRS)

    VanDyk, Schuyler D.; Zeng, Weikang; Fox, Ori D.; Cenko, S. Bradley; Clubb, Kelsey I.; Filippenko, Alexei; Foley, Ryan J.; Miller, Adam A.; Smith, Nathan; Kelly, Patrick L.; hide

    2014-01-01

    We have obtained early-time photometry and spectroscopy of supernova (SN) 2013df in NGC 4414. The SN is clearly of Type II b, with notable similarities to SN 1993J. From its luminosity at secondary maximum light, it appears that less Ni-56 (is approximately less than 0.06M) was synthesized in the SN 2013df explosion than was the case for the SNe II b 1993J, 2008ax, and 2011dh. Based on a comparison of the light curves, the SN 2013df progenitor must have been more extended in radius prior to explosion than the progenitor of SN 1993J. The total extinction for SN 2013dfis estimated to be A(sub V) = 0.30 mag. The metallicity at the SN location is likely to be solar. We have conducted Hubble Space Telescope(HST) Target of Opportunity observations of the SN with the Wide Field Camera 3, and from a precise comparison of these new observations to archival HST observations of the host galaxy obtained 14 yr prior to explosion, we have identified the progenitor of SN 2013df to be a yellow supergiant, somewhat hotter than a red supergiant progenitor for a normal Type II-Plateau SN. From its observed spectral energy distribution, assuming that the light is dominated by one star, the progenitor had effective temperature T(sub eff) = 4250+/-100 K and a bolometric luminosity L(sub bol) =10(exp 4.94+/-0.06) Solar Luminosity. This leads to an effective radius Reff = 545+/-65 Solar Radius. The star likely had an initial mass in the range of 13-17Solar Mass; however, if it was a member of an interacting binary system, detailed modeling of the system is required to estimate this mass more accurately. The progenitor star of SN 2013df appears to have been relatively similar to the progenitor of SN 1993J.

  17. Lack of Diaph3 relaxes the spindle checkpoint causing the loss of neural progenitors

    PubMed Central

    Damiani, Devid; Goffinet, André M.; Alberts, Arthur; Tissir, Fadel

    2016-01-01

    The diaphanous homologue Diaph3 (aka mDia2) is a major regulator of actin cytoskeleton. Loss of Diaph3 has been constantly associated with cytokinesis failure ascribed to impaired accumulation of actin in the cleavage furrow. Here we report that Diaph3 is required before cell fission, to ensure the accurate segregation of chromosomes. Inactivation of the Diaph3 gene causes a massive loss of cortical progenitor cells, with subsequent depletion of intermediate progenitors and neurons, and results in microcephaly. In embryonic brain extracts, Diaph3 co-immunoprecipitates with BubR1, a key regulator of the spindle assembly checkpoint (SAC). Diaph3-deficient cortical progenitors have decreased levels of BubR1 and fail to properly activate the SAC. Hence, they bypass mitotic arrest and embark on anaphase in spite of incorrect chromosome segregation, generating aneuploidy. Our data identify Diaph3 as a major guard of cortical progenitors, unravel novel functions of Diaphanous formins and add insights into the pathobiology of microcephaly. PMID:27848932

  18. Functional Definition of Progenitors Versus Mature Endothelial Cells Reveals Key SoxF-Dependent Differentiation Process.

    PubMed

    Patel, Jatin; Seppanen, Elke J; Rodero, Mathieu P; Wong, Ho Yi; Donovan, Prudence; Neufeld, Zoltan; Fisk, Nicholas M; Francois, Mathias; Khosrotehrani, Kiarash

    2017-02-21

    During adult life, blood vessel formation is thought to occur via angiogenic processes involving branching from existing vessels. An alternate proposal suggests that neovessels form from endothelial progenitors able to assemble the intimal layers. We here aimed to define vessel-resident endothelial progenitors in vivo in a variety of tissues in physiological and pathological situations such as normal aorta, lungs, and wound healing, tumors, and placenta, as well. Based on protein expression levels of common endothelial markers using flow cytometry, 3 subpopulations of endothelial cells could be identified among VE-Cadherin+ and CD45- cells. Lineage tracing by using Cdh5cre ERt2 /Rosa-YFP reporter strategy demonstrated that the CD31-/loVEGFR2lo/intracellular endothelial population was indeed an endovascular progenitor (EVP) of an intermediate CD31intVEGFR2lo/intracellular transit amplifying (TA) and a definitive differentiated (D) CD31hiVEGFR2hi/extracellular population. EVP cells arose from vascular-resident beds that could not be transferred by bone marrow transplantation. Furthermore, EVP displayed progenitor-like status with a high proportion of cells in a quiescent cell cycle phase as assessed in wounds, tumors, and aorta. Only EVP cells and not TA and D cells had self-renewal capacity as demonstrated by colony-forming capacity in limiting dilution and by transplantation in Matrigel plugs in recipient mice. RNA sequencing revealed prominent gene expression differences between EVP and D cells. In particular, EVP cells highly expressed genes related to progenitor function including Sox9 , Il33 , Egfr , and Pdfgrα. Conversely, D cells highly expressed genes related to differentiated endothelium including Ets1&2 , Gata2 , Cd31 , Vwf , and Notch . The RNA sequencing also pointed to an essential role of the Sox18 transcription factor. The role of SOX18 in the differentiation process was validated by using lineage-tracing experiments based on S ox18Cre ERt2 /Rosa

  19. Circulating endothelial progenitor cells and cardiovascular outcomes.

    PubMed

    Werner, Nikos; Kosiol, Sonja; Schiegl, Tobias; Ahlers, Patrick; Walenta, Katrin; Link, Andreas; Böhm, Michael; Nickenig, Georg

    2005-09-08

    Endothelial progenitor cells derived from bone marrow are believed to support the integrity of the vascular endothelium. The number and function of endothelial progenitor cells correlate inversely with cardiovascular risk factors, but the prognostic value associated with circulating endothelial progenitor cells has not been defined. The number of endothelial progenitor cells positive for CD34 and kinase insert domain receptor (KDR) was determined with the use of flow cytometry in 519 patients with coronary artery disease as confirmed on angiography. After 12 months, we evaluated the association between baseline levels of endothelial progenitor cells and death from cardiovascular causes, the occurrence of a first major cardiovascular event (myocardial infarction, hospitalization, revascularization, or death from cardiovascular causes), revascularization, hospitalization, and death from all causes. A total of 43 participants died, 23 from cardiovascular causes. A first major cardiovascular event occurred in 214 patients. The cumulative event-free survival rate increased stepwise across three increasing baseline levels of endothelial progenitor cells in an analysis of death from cardiovascular causes, a first major cardiovascular event, revascularization, and hospitalization. After adjustment for age, sex, vascular risk factors, and other relevant variables, increased levels of endothelial progenitor cells were associated with a reduced risk of death from cardiovascular causes (hazard ratio, 0.31; 95 percent confidence interval, 0.16 to 0.63; P=0.001), a first major cardiovascular event (hazard ratio, 0.74; 95 percent confidence interval, 0.62 to 0.89; P=0.002), revascularization (hazard ratio, 0.77; 95 percent confidence interval, 0.62 to 0.95; P=0.02), and hospitalization (hazard ratio, 0.76; 95 percent confidence interval, 0.63 to 0.94; P=0.01). Endothelial progenitor-cell levels were not predictive of myocardial infarction or of death from all causes. The level of

  20. [Therapy of intermediate uveitis].

    PubMed

    Doycheva, D; Deuter, C; Zierhut, M

    2014-12-01

    Intermediate uveitis is a form of intraocular inflammation in which the vitreous body is the major site of inflammation. Intermediate uveitis is primarily treated medicinally and systemic corticosteroids are the mainstay of therapy. When recurrence of uveitis or side effects occur during corticosteroid therapy an immunosuppressive treatment is required. Cyclosporine A is the only immunosuppressive agent that is approved for therapy of uveitis in Germany; however, other immunosuppressive drugs have also been shown to be effective and well-tolerated in patients with intermediate uveitis. In severe therapy-refractory cases when conventional immunosuppressive therapy has failed, biologics can be used. In patients with unilateral uveitis or when the systemic therapy is contraindicated because of side effects, an intravitreal steroid treatment can be carried out. In certain cases a vitrectomy may be used.

  1. Sources of Hematopoietic Stem and Progenitor Cells and Methods to Optimize Yields for Clinical Cell Therapy.

    PubMed

    Panch, Sandhya R; Szymanski, James; Savani, Bipin N; Stroncek, David F

    2017-08-01

    Bone marrow (BM) aspirates, mobilized peripheral blood, and umbilical cord blood (UCB) have developed as graft sources for hematopoietic stem and progenitor cells (HSPCs) for stem cell transplantation and other cellular therapeutics. Individualized techniques are necessary to enhance graft HSPC yields and cell quality from each graft source. BM aspirates yield adequate CD34 + cells but can result in relative delays in engraftment. Granulocyte colony-stimulating factor (G-CSF)-primed BM HSPCs may facilitate faster engraftment while minimizing graft-versus-host disease in certain patient subsets. The levels of circulating HSPCs are enhanced using mobilizing agents, such as G-CSF and/or plerixafor, which act via the stromal cell-derived factor 1/C-X-C chemokine receptor type 4 axis. Alternate niche pathway mediators, including very late antigen-4/vascular cell adhesion molecule-1, heparan sulfate proteoglycans, parathyroid hormone, and coagulation cascade intermediates, may offer promising alternatives for graft enhancement. UCB grafts have been expanded ex vivo with cytokines, notch-ligand, or mesenchymal stromal cells, and most studies demonstrated greater quantities of CD34 + cells ex vivo and improved short-term engraftment. No significant changes were observed in long-term repopulating potential or in patient survival. Early phase clinical trials using nicotinamide and StemReginin1 may offer improved short- and long-term repopulating ability. Breakthroughs in genome editing and stem cell reprogramming technologies may hasten the generation of pooled, third-party HSPC grafts. This review elucidates past, present, and potential future approaches to HSPC graft optimization. Published by Elsevier Inc.

  2. A single-cell resolution map of mouse hematopoietic stem and progenitor cell differentiation.

    PubMed

    Nestorowa, Sonia; Hamey, Fiona K; Pijuan Sala, Blanca; Diamanti, Evangelia; Shepherd, Mairi; Laurenti, Elisa; Wilson, Nicola K; Kent, David G; Göttgens, Berthold

    2016-08-25

    Maintenance of the blood system requires balanced cell fate decisions by hematopoietic stem and progenitor cells (HSPCs). Because cell fate choices are executed at the individual cell level, new single-cell profiling technologies offer exciting possibilities for mapping the dynamic molecular changes underlying HSPC differentiation. Here, we have used single-cell RNA sequencing to profile more than 1600 single HSPCs, and deep sequencing has enabled detection of an average of 6558 protein-coding genes per cell. Index sorting, in combination with broad sorting gates, allowed us to retrospectively assign cells to 12 commonly sorted HSPC phenotypes while also capturing intermediate cells typically excluded by conventional gating. We further show that independently generated single-cell data sets can be projected onto the single-cell resolution expression map to directly compare data from multiple groups and to build and refine new hypotheses. Reconstruction of differentiation trajectories reveals dynamic expression changes associated with early lymphoid, erythroid, and granulocyte-macrophage differentiation. The latter two trajectories were characterized by common upregulation of cell cycle and oxidative phosphorylation transcriptional programs. By using external spike-in controls, we estimate absolute messenger RNA (mRNA) levels per cell, showing for the first time that despite a general reduction in total mRNA, a subset of genes shows higher expression levels in immature stem cells consistent with active maintenance of the stem-cell state. Finally, we report the development of an intuitive Web interface as a new community resource to permit visualization of gene expression in HSPCs at single-cell resolution for any gene of choice. © 2016 by The American Society of Hematology.

  3. Compensatory Response by Late Embryonic Tubular Epithelium to the Reduction in Pancreatic Progenitors

    PubMed Central

    Nishimura, Wataru; Kapoor, Archana; El Khattabi, Ilham; Jin, Wanzhu; Yasuda, Kazuki; Bonner-Weir, Susan; Sharma, Arun

    2015-01-01

    Early in pancreatic development, epithelial cells of pancreatic buds function as primary multipotent progenitor cells (1°MPC) that specify all three pancreatic cell lineages, i.e., endocrine, acinar and duct. Bipotent "Trunk" progenitors derived from 1°MPC are implicated in directly regulating the specification of endocrine progenitors. It is unclear if this specification process is initiated in the 1°MPC where some 1°MPC become competent for later specification of endocrine progenitors. Previously we reported that in Pdx1 tTA/+ ;tetO MafA (bigenic) mice inducing expression of transcription factor MafA in Pdx1-expressing (Pdx1+) cells throughout embryonic development inhibited the proliferation and differentiation of 1°MPC cells, resulting in reduced pancreatic mass and endocrine cells by embryonic day (E) 17.5. Induction of the transgene only until E12.5 in Pdx1+ 1°MPC was sufficient for this inhibition of endocrine cells and pancreatic mass at E17.5. However, by birth (P0), as we now report, such bigenic pups had significantly increased pancreatic and endocrine volumes with endocrine clusters containing all pancreatic endocrine cell types. The increase in endocrine cells resulted from a higher proliferation of tubular epithelial cells expressing the progenitor marker Glut2 in E17.5 bigenic embryos and increased number of Neurog3-expressing cells at E19.5. A BrdU-labeling study demonstrated that inhibiting proliferation of 1°MPC by forced MafA-expression did not lead to retention of those progenitors in E17.5 tubular epithelium. Our data suggest that the forced MafA expression in the 1°MPC inhibits their competency to specify endocrine progenitors only until E17.5, and after that compensatory proliferation of tubular epithelium gives rise to a distinct pool of endocrine progenitors. Thus, these bigenic mice provide a novel way to characterize the competency of 1°MPC for their ability to specify endocrine progenitors, a critical limitation in our

  4. Neuropeptides: Developmental Signals in Placode Progenitor Formation

    PubMed Central

    Lleras-Forero, Laura; Tambalo, Monica; Christophorou, Nicolas; Chambers, David; Houart, Corinne; Streit, Andrea

    2013-01-01

    Summary Few families of signaling factors have been implicated in the control of development. Here, we identify the neuropeptides nociceptin and somatostatin, a neurotransmitter and neuroendocrine hormone, as a class of developmental signals in both chick and zebrafish. We show that signals from the anterior mesendoderm are required for the formation of anterior placode progenitors, with one of the signals being somatostatin. Somatostatin controls ectodermal expression of nociceptin, and both peptides regulate Pax6 in lens and olfactory progenitors. Consequently, loss of somatostatin and nociceptin signaling leads to severe reduction of lens formation. Our findings not only uncover these neuropeptides as developmental signals but also identify a long-sought-after mechanism that initiates Pax6 in placode progenitors and may explain the ancient evolutionary origin of neuropeptides, predating a complex nervous system. PMID:23906067

  5. Perturbed hematopoietic stem and progenitor cell hierarchy in myelodysplastic syndromes patients with monosomy 7 as the sole cytogenetic abnormality.

    PubMed

    Dimitriou, Marios; Woll, Petter S; Mortera-Blanco, Teresa; Karimi, Mohsen; Wedge, David C; Doolittle, Helen; Douagi, Iyadh; Papaemmanuil, Elli; Jacobsen, Sten Eirik W; Hellström-Lindberg, Eva

    2016-11-08

    The stem and progenitor cell compartments in low- and intermediate-risk myelodysplastic syndromes (MDS) have recently been described, and shown to be highly conserved when compared to those in acute myeloid leukemia (AML). Much less is known about the characteristics of the hematopoietic hierarchy of subgroups of MDS with a high risk of transforming to AML. Immunophenotypic analysis of immature stem and progenitor cell compartments from patients with an isolated loss of the entire chromosome 7 (isolated -7), an independent high-risk genetic event in MDS, showed expansion and dominance of the malignant -7 clone in the granulocyte and macrophage progenitors (GMP), and other CD45RA+ progenitor compartments, and a significant reduction of the LIN-CD34+CD38low/-CD90+CD45RA- hematopoietic stem cell (HSC) compartment, highly reminiscent of what is typically seen in AML, and distinct from low-risk MDS. Established functional in vitro and in vivo stem cell assays showed a poor readout for -7 MDS patients irrespective of marrow blast counts. Moreover, while the -7 clone dominated at all stages of GM differentiation, the -7 clone had a competitive disadvantage in erythroid differentiation. In azacitidine-treated -7 MDS patients with a clinical response, the decreased clonal involvement in mononuclear bone marrow cells was not accompanied by a parallel reduced clonal involvement in the dominant CD45RA+ progenitor populations, suggesting a selective azacitidine-resistance of these distinct -7 progenitor compartments. Our data demonstrate, in a subgroup of high risk MDS with monosomy 7, that the perturbed stem and progenitor cell compartments resemble more that of AML than low-risk MDS.

  6. INTERMEDIATE READINGS IN TAGALOG.

    ERIC Educational Resources Information Center

    BOWEN, J. DONALD, ED.

    THE SECOND IN A SERIES OF TEXTS DESIGNED TO HELP THE STUDENT ACHIEVE AN UNDERSTANDING OF FILIPINO CULTURE AND ACQUIRE ENOUGH PROFICIENCY IN TAGALOG TO COMMUNICATE EASILY AND MEANINGFULLY, THESE INTERMEDIATE READINGS ARE COORDINATED WITH THE EDITOR'S "BEGINNING TAGALOG" (ED 014 696). INCLUDED IN PART I ARE READINGS WRITTEN ESPECIALLY FOR THIS TEXT…

  7. SPACE: Intermediate Level Modules.

    ERIC Educational Resources Information Center

    Indiana State Dept. of Education, Indianapolis. Center for School Improvement and Performance.

    These modules were developed to assist teachers at the intermediate level to move away from extensive skill practice and toward more meaningful interdisciplinary learning. This packet, to be used by teachers in the summer Extended Learning Program, provides detailed thematic lesson plans matched to the Indiana Curriculum Proficiency Guide. The…

  8. Endothelial progenitor cells--an evolving story.

    PubMed

    Pearson, Jeremy D

    2010-05-01

    The first description of endothelial progenitor cells (EPC) in 1997 led rapidly to substantial changes in our understanding of angiogenesis, and within 5 years to the first clinical studies in humans using bone marrow derived EPC to enhance coronary neovascularisation and cardiac function after myocardial ischemia. However, to improve the success of this therapy a clearer understanding of the biology of EPC is needed. This article summarises recent data indicating that most EPC are not, in fact, endothelial progenitors but can be better described as angiogenic monocytes, and explores the implications this has for their future therapeutic use. Copyright 2009 Elsevier Inc. All rights reserved.

  9. On the progenitors of Type Ia supernovae

    NASA Astrophysics Data System (ADS)

    Livio, Mario; Mazzali, Paolo

    2018-03-01

    We review all the models proposed for the progenitor systems of Type Ia supernovae and discuss the strengths and weaknesses of each scenario when confronted with observations. We show that all scenarios encounter at least a few serious difficulties, if taken to represent a comprehensive model for the progenitors of all Type Ia supernovae (SNe Ia). Consequently, we tentatively conclude that there is probably more than one channel leading SNe Ia. While the single-degenerate scenario (in which a single white dwarf accretes mass from a normal stellar companion) has been studied in some detail, the other scenarios will need a similar level of scrutiny before any firm conclusions can be drawn.

  10. Changes in the frequencies of human hematopoietic stem and progenitor cells with age and site

    PubMed Central

    Farrell, TL; McGuire, TR; Bilek, L; Brusnahan, SK; Jackson, JD; Lane, JT; Garvin, KL; O'Kane, BJ; Berger, AM; Tuljapurkar, SR; Kessinger, MA; Sharp, JG

    2013-01-01

    This study enumerated CD45hi/CD34+ and CD45hi/CD133+ human hematopoietic stem cells (HSC) and granulocyte-monocyte colony forming (GM-CFC) progenitor cells in blood and trochanteric and femoral bone marrow in 233 individuals. Stem cell frequencies were determined by multi-parameter flow cytometry employing an internal control to determine the intrinsic variance of the assays. Progenitor cell frequency was determined using a standard colony assay technique. The frequency of outliers from undetermined methodological causes was highest for blood but less than 5% for all values. The frequency of CD45hi/CD133+ cells correlated highly with the frequency of CD45hi/CD34+ cells in trochanteric and femoral bone marrow. The frequency of these HSC populations in trochanteric and femoral bone marrow rose significantly with age. In contrast, there was no significant trend of either of these cell populations with age in the blood. Trochanteric marrow GM-CFC progenitor cells showed no significant trends with age, but femoral marrow GM-CFC trended downward with age, potentially because of the reported conversion of red marrow at this site to fat with age. Hematopoietic stem and progenitor cells exhibited changes in frequencies with age that differed between blood and bone marrow. We previously reported that side population (SP) multipotential HSC, that include the precursors of CD45hi/CD133+ and CD45hi/CD34+, decline with age. Potentially the increases in stem cell frequencies in the intermediate compartment between SP and GM progenitor cells observed in this study represent a compensatory increase for the loss of more potent members of the HSC hierarchy. PMID:24246745

  11. Extramedullary Myelopoiesis in Malaria Depends on Mobilization of Myeloid-Restricted Progenitors by IFN-γ Induced Chemokines

    PubMed Central

    Belyaev, Nikolai N.; Biró, Judit; Langhorne, Jean; Potocnik, Alexandre J.

    2013-01-01

    Resolution of a variety of acute bacterial and parasitic infections critically relies on the stimulation of myelopoiesis leading in cases to extramedullary hematopoiesis. Here, we report the isolation of the earliest myeloid-restricted progenitors in acute infection with the rodent malaria parasite, Plasmodium chabaudi. The rapid disappearance of these infection-induced myeloid progenitors from the bone marrow (BM) equated with contraction of the functional myeloid potential in that organ. The loss of BM myelopoiesis was not affected by the complete genetic inactivation of toll-like receptor signaling. De-activation of IFN-γ signaling completely abrogated the contraction of BM myeloid progenitors. Radiation chimeras of Ifngr1-null and control BM revealed that IFN-γ signaling in an irradiation-resistant stromal compartment was crucial for the loss of early myeloid progenitors. Systemic IFN-γ triggered the secretion of C-C motif ligand chemokines CCL2 and CCL7 leading to the egress of early, myeloid-committed progenitors from the bone marrow mediated by their common receptor CCR2. The mobilization of myeloid progenitors initiated extramedullary myelopoiesis in the spleen in a CCR2-dependent manner resulting in augmented myelopoiesis during acute malaria. Consistent with the lack of splenic myelopoiesis in the absence of CCR2 we observed a significant persistence of parasitemia in malaria infected CCR2-deficient hosts. Our findings reveal how the activated immune system mobilizes early myeloid progenitors out of the BM thereby transiently establishing myelopoiesis in the spleen in order to contain and resolve the infection locally. PMID:23762028

  12. Prenatal stress delays inhibitory neuron progenitor migration in the developing neocortex

    PubMed Central

    Stevens, Hanna E.; Su, Tina; Yanagawa, Yuchio; Vaccarino, Flora M.

    2012-01-01

    Summary Prenatal stress has been widely demonstrated to have links with behavioral problems in clinical populations and animal models, however, few investigations have examined the immediate developmental events that are affected by prenatal stress. Here, we utilize GAD67GFP transgenic mice in which GABAergic progenitors express green fluorescent protein (GFP) to examine the impact of prenatal stress on the development of these precursors to inhibitory neurons. Pregnant female mice were exposed to restraint stress three times daily from embryonic day 12 (E12) onwards. Their offspring demonstrated changes in the distribution of GFP-positive (GFP+) GABAergic progenitors in the telencephalon as early as E13 and persisting until postnatal day 0. Changes in distribution reflected alterations in tangential migration and radial integration of GFP+ cells into the developing cortical plate. Fate mapping of GAD67GFP+progenitors with bromodeoxyuridine injected at E13 demonstrated a significant increase of these cells at P0 in anterior white matter. An overall decrease in GAD67GFP+ progenitors at P0 in medial frontal cortex could not be attributed to a reduction in cell proliferation. Significant changes in dlx2, nkx2.1 and their downstream target erbb4, transcription factors which regulate interneuron migration, were found within the prenatally-stressed developing forebrain, while no differences were seen in mash1, a determinant of interneuron fate, bdnf, a maturation factor for GABAergic cells or fgf2, an early growth/differentiation factor. These results demonstrate that early disruption in GABAergic progenitor migration caused by prenatal stress may be responsible for neuronal defects in disorders with GABAergic abnormalities like schizophrenia. PMID:22910687

  13. SN Ia archaeology: Searching for the relics of progenitors past

    NASA Astrophysics Data System (ADS)

    Woods, Tyrone E.; Gilfanov, Marat; Clocchiatti, Alejandro; Rest, Armin

    2016-06-01

    Despite the critical role that SNe Ia play in the chemical enrichment of the Universe and their great importance in measuring cosmological distances, we still don't know for certain how they arise. In the canonical form of the ``single-degenerate'' scenario, a white dwarf grows through the nuclear burning of matter accreted at its surface from some companion star. This renders it a hot, luminous object (a supersoft X-ray source or SSS, 10^5-10^6K, 10^{38} erg/s) for up to a million years prior to explosion. Past efforts to directly detect the progenitors of very recent, nearby SNe Ia in archival soft X-ray images have produced only upper limits, and are only constraining assuming progenitors with much higher temperatures than known SSSs. In this talk, I will outline an alternative approach: given that such objects should be strong sources of ionizing radiation, one may instead search the environment surrounding nearby SN Ia remnants for interstellar matter ionized by the progenitor. Such fossil nebulae should extend out to tens of parsecs and linger for roughly the recombination timescale in the ISM, of order 10,000 — 100,000 years. Progress on this front has been hampered by the failure to detect nebulae surrounding most known SSSs using 1m class telescopes in the early 1990s. I will present new benchmark calculations for the emission-line nebulae expected to surround such objects, demonstrating that previous non-detections are entirely consistent with the low ISM densities expected in the vicinity of most SN Ia progenitors (Woods & Gilfanov, 2016). Modern large optical telescopes are now well able to reach the required limiting surface brightness needed to find such faint emission. With this in mind, I will introduce our new narrow-band survey for fossil nebulae surrounding young Magellanic SN Ia remnants and SSSs, already underway using the Magellan Baade telescope (PI: Alejandro Clocchiatti). In addition to opening a new era of SN Ia archaeology, I will show

  14. Metallicity gradient of the thick disc progenitor at high redshift

    NASA Astrophysics Data System (ADS)

    Kawata, Daisuke; Allende Prieto, Carlos; Brook, Chris B.; Casagrande, Luca; Ciucă, Ioana; Gibson, Brad K.; Grand, Robert J. J.; Hayden, Michael R.; Hunt, Jason A. S.

    2018-01-01

    We have developed a novel Markov Chain Monte Carlo chemical 'painting' technique to explore possible radial and vertical metallicity gradients for the thick disc progenitor. In our analysis, we match an N-body simulation to the data from the Apache Point Observatory Galactic Evolution Experiment survey. We assume that the thick disc has a constant scaleheight and has completed its formation at an early epoch, after which time radial mixing of its stars has taken place. Under these assumptions, we find that the initial radial metallicity gradient of the thick disc progenitor should not be negative, but either flat or even positive, to explain the current negative vertical metallicity gradient of the thick disc. Our study suggests that the thick disc was built-up in an inside-out and upside-down fashion, and older, smaller and thicker populations are more metal poor. In this case, star-forming discs at different epochs of the thick disc formation are allowed to have different radial metallicity gradients, including a negative one, which helps to explain a variety of slopes observed in high-redshift disc galaxies. This scenario helps to explain the positive slope of the metallicity-rotation velocity relation observed for the Galactic thick disc. On the other hand, radial mixing flattens the slope of an existing gradient.

  15. A Wolf-Rayet-Like Progenitor of SN 2013cu from Spectral Observations of a Stellar Wind

    NASA Technical Reports Server (NTRS)

    Gal-Yam, Avishay; Arcavi, I.; Ofek, E. O.; Ben-Ami, S.; Cenko, S. B.; Kasliwal, M. M.; Cao, Y.; Yaron, O.; Tal, D.; Silverman, J. M.; hide

    2014-01-01

    The explosive fate of massive Wolf-Rayet stars (WRSs) is a key open question in stellar physics. An appealing option is that hydrogen- deficient WRSs are the progenitors of some hydrogen-poor supernova explosions of types IIb, Ib and Ic. A blue object, having luminosity and colours consistent with those of some WRSs, has recently been identified in pre-explosion images at the location of a supernova of type Ib, but has not yet been conclusively determined to have been the progenitor. Similar work has so far only resulted in non-detections. Comparison of early photometric observations of type Ic supernovae with theoretical models suggests that the progenitor stars had radii of less than 10(exp 12) centimetres, as expected for some WRSs. The signature of WRSs, their emission line spectra, cannot be probed by such studies. Here we report the detection of strong emission lines in a spectrum of type IIb supernova 2013cu (iPTF13ast) obtained approximately 15.5 hours after explosion (by 'flash spectroscopy', which captures the effects of the supernova explosion shock breakout flash on material surrounding the progenitor star).We identify Wolf-Rayet-like wind signatures, suggesting a progenitor of the WN(h) subclass (those WRSs with winds dominated by helium and nitrogen, with traces of hydrogen). The extent of this dense wind may indicate increased mass loss from the progenitor shortly before its explosion, consistent with recent theoretical predictions.

  16. A Wolf-Rayet-like progenitor of SN 2013cu from spectral observations of a stellar wind.

    PubMed

    Gal-Yam, Avishay; Arcavi, I; Ofek, E O; Ben-Ami, S; Cenko, S B; Kasliwal, M M; Cao, Y; Yaron, O; Tal, D; Silverman, J M; Horesh, A; De Cia, A; Taddia, F; Sollerman, J; Perley, D; Vreeswijk, P M; Kulkarni, S R; Nugent, P E; Filippenko, A V; Wheeler, J C

    2014-05-22

    The explosive fate of massive Wolf-Rayet stars (WRSs) is a key open question in stellar physics. An appealing option is that hydrogen-deficient WRSs are the progenitors of some hydrogen-poor supernova explosions of types IIb, Ib and Ic (ref. 2). A blue object, having luminosity and colours consistent with those of some WRSs, has recently been identified in pre-explosion images at the location of a supernova of type Ib (ref. 3), but has not yet been conclusively determined to have been the progenitor. Similar work has so far only resulted in non-detections. Comparison of early photometric observations of type Ic supernovae with theoretical models suggests that the progenitor stars had radii of less than 10(12) centimetres, as expected for some WRSs. The signature of WRSs, their emission line spectra, cannot be probed by such studies. Here we report the detection of strong emission lines in a spectrum of type IIb supernova 2013cu (iPTF13ast) obtained approximately 15.5 hours after explosion (by 'flash spectroscopy', which captures the effects of the supernova explosion shock breakout flash on material surrounding the progenitor star). We identify Wolf-Rayet-like wind signatures, suggesting a progenitor of the WN(h) subclass (those WRSs with winds dominated by helium and nitrogen, with traces of hydrogen). The extent of this dense wind may indicate increased mass loss from the progenitor shortly before its explosion, consistent with recent theoretical predictions.

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

    PubMed

    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.

  18. Targeting human oligodendrocyte progenitors for myelin repair☆

    PubMed Central

    Dietz, Karen C.; Polanco, Jessie J.; Pol, Suyog U.; Sim, Fraser J.

    2017-01-01

    Oligodendrocyte development has been studied for several decades, and has served as a model system for both neurodevelopmental and stem/progenitor cell biology. Until recently, the vast majority of studies have been conducted in lower species, especially those focused on rodent development and remyelination. In humans, the process of myelination requires the generation of vastly more myelinating glia, occurring over a period of years rather than weeks. Furthermore, as evidenced by the presence of chronic demyelination in a variety of human neurologic diseases, it appears likely that the mechanisms that regulate development and become dysfunctional in disease may be, in key ways, divergent across species. Improvements in isolation techniques, applied to primary human neural and oligodendrocyte progenitors from both fetal and adult brain, as well as advancements in the derivation of defined progenitors from human pluripotent stem cells, have begun to reveal the extent of both species-conserved signaling pathways and potential key differences at cellular and molecular levels. In this article, we will review the commonalities and differences in myelin development between rodents and man, describing the approaches used to study human oligodendrocyte differentiation and myelination, as well as heterogeneity within targetable progenitor pools, and discuss the advances made in determining which conserved pathways may be both modeled in rodents and translate into viable therapeutic strategies to promote myelin repair. PMID:27001544

  19. Obstructive sleep apnea and endothelial progenitor cells.

    PubMed

    Wang, Qing; Wu, Qi; Feng, Jing; Sun, Xin

    2013-10-18

    Obstructive sleep apnea (OSA) occurs in 4% of middle-aged men and 2% of middle-aged women in the general population, and the prevalence is even higher in specific patient groups. OSA is an independent risk factor for a variety of cardiovascular diseases. Endothelial injury could be the pivotal determinant in the development of cardiovascular pathology in OSA. Endothelial damage ultimately represents a dynamic balance between the magnitude of injury and the capacity for repair. Bone marrow-derived endothelial progenitor cells (EPCs) within adult peripheral blood present a possible means of vascular maintenance that could home to sites of injury and restore endothelial integrity and normal function. We summarized pathogenetic mechanisms of OSA and searched for available studies on numbers and functions of EPCs in patients with OSA to explore the potential links between the numbers and functions of EPCs and OSA. In particular, we tried to elucidate the molecular mechanisms of the effects of OSA on EPCs. Intermittent hypoxia cycles and sleep fragmentation are major pathophysiologic characters of OSA. Intermittent hypoxia acts as a trigger of oxidative stress, systemic inflammation, and sympathetic activation. Sleep fragmentation is associated with a burst of sympathetic activation and systemic inflammation. In most studies, a reduction in circulating EPCs has emerged. The possible mechanisms underlying the decrease in the number or function of EPCs include prolonged inflammation response, oxidative stress, increased sympathetic activation, physiological adaptive responses of tissue to hypoxia, reduced EPC mobilization, EPC apoptosis, and functional impairment in untreated OSA. Continuous positive airway pressure (CPAP) therapy for OSA affects the mobilization, apoptosis, and function of EPCs through preventing intermittent hypoxia episodes, improving sleep quality, and reducing systemic inflammation, oxidative stress levels, and sympathetic overactivation. To improve

  20. GFP's Mechanical Intermediate States

    PubMed Central

    Saeger, John; Hytönen, Vesa P.; Klotzsch, Enrico; Vogel, Viola

    2012-01-01

    Green fluorescent protein (GFP) mutants have become the most widely used fluorescence markers in the life sciences, and although they are becoming increasingly popular as mechanical force or strain probes, there is little direct information on how their fluorescence changes when mechanically stretched. Here we derive high-resolution structural models of the mechanical intermediate states of stretched GFP using steered molecular dynamics (SMD) simulations. These structures were used to produce mutants of EGFP and EYFP that mimic GFP's different mechanical intermediates. A spectroscopic analysis revealed that a population of EGFP molecules with a missing N-terminal α-helix was significantly dimmed, while the fluorescence lifetime characteristic of the anionic chromophore state remained unaffected. This suggests a mechanism how N-terminal deletions can switch the protonation state of the chromophore, and how the fluorescence of GFP molecules in response to mechanical disturbance might be turned off. PMID:23118864

  1. The Intermediate Neutrino Program

    SciTech Connect

    Adams, C.; Alonso, J. R.; Ankowski, A. M.

    2017-04-03

    The US neutrino community gathered at the Workshop on the Intermediate Neutrino Program (WINP) at Brookhaven National Laboratory February 4-6, 2015 to explore opportunities in neutrino physics over the next five to ten years. Scientists from particle, astroparticle and nuclear physics participated in the workshop. The workshop examined promising opportunities for neutrino physics in the intermediate term, including possible new small to mid-scale experiments, US contributions to large experiments, upgrades to existing experiments, R&D plans and theory. The workshop was organized into two sets of parallel working group sessions, divided by physics topics and technology. Physics working groups covered topicsmore » on Sterile Neutrinos, Neutrino Mixing, Neutrino Interactions, Neutrino Properties and Astrophysical Neutrinos. Technology sessions were organized into Theory, Short-Baseline Accelerator Neutrinos, Reactor Neutrinos, Detector R&D and Source, Cyclotron and Meson Decay at Rest sessions.This report summarizes discussion and conclusions from the workshop.« less

  2. Intermediate water recovery system

    NASA Technical Reports Server (NTRS)

    Deckman, G.; Anderson, A. R. (Editor)

    1973-01-01

    A water recovery system for collecting, storing, and processing urine, wash water, and humidity condensates from a crew of three aboard a spacecraft is described. The results of a 30-day test performed on a breadboard system are presented. The intermediate water recovery system produced clear, sterile, water with a 96.4 percent recovery rate from the processed urine. Recommendations for improving the system are included.

  3. Apoptosis and proliferation of oligodendrocyte progenitor cells in the irradiated rodent spinal cord

    SciTech Connect

    Atkinson, Shelley L.; Li Yuqing; Wong, C. Shun

    2005-06-01

    Purpose: Oligodendrocytes undergo early apoptosis after irradiation. The aim of this study was to determine the relationship between oligodendroglial apoptosis and proliferation of oligodendrocyte progenitor cells (OPC) in the irradiated central nervous system. Methods and Materials: Adult rats and p53 transgenic mice were given single doses of 2 Gy, 8 Gy, or 22 Gy to the cervical spinal cord. Apoptosis was assessed using TUNEL (Tdt-mediated dUTP terminal nick-end labeling) staining or by examining nuclear morphology. Oligodendrocyte progenitor cells were identified with an NG2 antibody or by in situ hybridization for platelet-derived growth factor receptor {alpha}. Proliferation of OPC was assessedmore » by in vivo bromodeoxyuridine (BrdU) labeling and subsequent immunohistochemistry. Because radiation-induced apoptosis of oligodendroglial cells is p53 dependent, p53 transgenic mice were used to study the relationship between apoptosis and cell proliferation. Results: Oligodendrocyte progenitor cells underwent apoptosis within 24 h of irradiation in the rat. That did not result in a change in OPC density at 24 h. Oligodendrocyte progenitor cell density was significantly reduced by 2-4 weeks, but showed recovery by 6 weeks after irradiation. An increase in BrdU-labeled cells was observed at 2 weeks after 8 Gy or 22 Gy, and proliferating cells in the rat spinal cord were immunoreactive for NG2. The mouse spinal cord showed a similar early cell proliferation after irradiation. No difference was observed in the proliferation response in the spinal cord of p53 -/- mice compared with wild type animals. Conclusions: Oligodendroglial cells undergo early apoptosis and OPC undergo early proliferation after ionizing radiation. However, apoptosis is not likely to be the trigger for early proliferation of OPC in the irradiated central nervous system.« less

  4. Chondrosarcoma: A Rare Misfortune in Aging Human Cartilage? The Role of Stem and Progenitor Cells in Proliferation, Malignant Degeneration and Therapeutic Resistance

    PubMed Central

    Boehme, Karen A.; Schleicher, Sabine B.; Rolauffs, Bernd

    2018-01-01

    Unlike other malignant bone tumors including osteosarcomas and Ewing sarcomas with a peak incidence in adolescents and young adults, conventional and dedifferentiated chondrosarcomas mainly affect people in the 4th to 7th decade of life. To date, the cell type of chondrosarcoma origin is not clearly defined. However, it seems that mesenchymal stem and progenitor cells (MSPC) in the bone marrow facing a pro-proliferative as well as predominantly chondrogenic differentiation milieu, as is implicated in early stage osteoarthritis (OA) at that age, are the source of chondrosarcoma genesis. But how can MSPC become malignant? Indeed, only one person in 1,000,000 will develop a chondrosarcoma, whereas the incidence of OA is a thousandfold higher. This means a rare coincidence of factors allowing escape from senescence and apoptosis together with induction of angiogenesis and migration is needed to generate a chondrosarcoma. At early stages, chondrosarcomas are still assumed to be an intermediate type of tumor which rarely metastasizes. Unfortunately, advanced stages show a pronounced resistance both against chemo- and radiation-therapy and frequently metastasize. In this review, we elucidate signaling pathways involved in the genesis and therapeutic resistance of chondrosarcomas with a focus on MSPC compared to signaling in articular cartilage (AC). PMID:29361725

  5. Panchromatic Observations of SN2011dh Point to a Compact Progenitor Star

    NASA Technical Reports Server (NTRS)

    Soderberg, A. M.; Margutti, R.; Zauerer, B. A.; Krauss, M.; Katz, B.; Chomiuk, L.; Dittmann, J. A.; Nakar, E.; Sakamoto, T.; Kawai, N.; hide

    2011-01-01

    We report the discovery and detailed monitoring of X-ray emission associated with the Type IIb SN2011dh using data from the Swift and Chandra satellites, placing it among the best studied X-ray supernovae to date. We further present millimeter and radio data obtained with the SMA, CARMA, and EVLA during the first three weeks after explosion. Combining these observations with early optical photometry, we show that the panchromatic dataset is well-described by non-thermal synchrotron emission (radio/mm) with inverse Compton scattering (X-ray) of a thermal population of optical photons. We derive the properties of the shockwave and the circumstellar environment and find a time-averaged shock velocity of v approximately equals 0.1c and a progenitor mass loss rate of M-dot approximately equals 6 X 10 (exp 5) Solar M/ yr (wind velocity, v(sub w) = 1000 km/s). We show that these properties are consistent with the sub-class of Type IIb supernovae characterized by compact progenitors (Type cIIb) and dissimilar from those with extended progenitors (Type eIIb). Furthermore, we consider the early optical emission in the context of a cooling envelope model to estimate a progenitor radius of R(sub star) approximately equals 10(exp 11) cm, in line with the expectations for a Type cIIb supernova. Together, these diagnostics suggest that the putative yellow supergiant progenitor star identified in archival HST observations is instead a binary companion or unrelated to the supernova. Finally, we searched for the high energy shock breakout pulse using X-ray and gamma-ray observations obtained during the purported explosion date range. Based on the compact radius of the progenitor, we estimate that the shock breakout pulse was detectable with current instruments but likely missed due to their limited temporal/ spatial coverage. Future all-sky missions will regularly detect shock breakout emission from compact SN progenitors enabling prompt follow-up observations of the shockwave with

  6. Hepatocyte growth factor induces proliferation and differentiation of multipotent and erythroid hemopoietic progenitors.

    PubMed

    Galimi, F; Bagnara, G P; Bonsi, L; Cottone, E; Follenzi, A; Simeone, A; Comoglio, P M

    1994-12-01

    Hepatocyte growth factor (HGF) is a mesenchymal derived growth factor known to induce proliferation and "scattering" of epithelial and endothelial cells. Its receptor is the tyrosine kinase encoded by the c-MET protooncogene. Here we show that highly purified recombinant HGF stimulates hemopoietic progenitors to form colonies in vitro. In the presence of erythropoietin, picomolar concentrations of HGF induced the formation of erythroid burst-forming unit colonies from CD34-positive cells purified from human bone marrow, peripheral blood, or umbilical cord blood. The growth stimulatory activity was restricted to the erythroid lineage. HGF also stimulated the formation of multipotent CFU-GEMM colonies. This effect is synergized by stem cell factor, the ligand of the tyrosine kinase receptor encoded by the c-KIT protooncogene, which is active on early hemopoietic progenitors. By flow cytometry analysis, the receptor for HGF was found to be expressed on the cell surface in a fraction of CD34+ progenitors. Moreover, in situ hybridization experiments showed that HGF receptor mRNA is highly expressed in embryonic erythroid cells (megaloblasts). HGF mRNA was also found to be produced in the embryonal liver. These data show that HGF plays a direct role in the control of proliferation and differentiation of erythroid progenitors, and they suggest that it may be one of the long-sought mediators of paracrine interactions between stromal and hemopoietic cells within the hemopoietic microenvironment.

  7. Pigmentation Is Associated with Stemness Hierarchy of Progenitor Cells Within Cultured Limbal Epithelial Cells.

    PubMed

    Liu, Lei; Nielsen, Frederik Mølgaard; Emmersen, Jeppe; Bath, Chris; Hjortdal, Jesper Østergaard; Riis, Simone; Fink, Trine; Pennisi, Cristian Pablo; Zachar, Vladimir

    2018-05-20

    Ex-vivo cultured human limbal epithelial stem/progenitor cells (hLESCs) are the main source for regenerative therapy of limbal stem cell deficiency (LSCD), which is worldwide one of the major causes of corneal blindness. Despite many stemness-associated markers have been identified within the limbal niche, the phenotype of the earliest hLESCs has not been hitherto identified. We sought to confirm or refute the use of tumor protein p63 (p63) and ATP binding cassette subfamily B member 5 (ABCB5) as surrogate markers for hLESCs early within the limbal differentiation hierarchy. Based on a robust fluorescence-activated cell sorting (FACS) and subsequent RNA isolation protocol, a comprehensive transcriptomic profile was obtained from four subpopulations of cultured hLESCs. The subpopulations were defined by co-expression of two putative stem/progenitor markers, the p63 and ABCB5, and the corneal differentiation marker cytokeratin 3 (CK3). A comparative transcriptomic analysis yielded novel data that indicated association between pigmentation and differentiation, with the p63 positive populations being the most pigmented and immature of the progenitors. In contrast, ABCB5, either alone or in co-expression patterns, identified more committed progenitor cells with less pigmentation. In conclusion, p63 is superior to ABCB5 as a marker for stemness. This article is protected by copyright. All rights reserved. © 2018 AlphaMed Press.

  8. CLUES to the past: Local Group progenitors amongst high-redshift Lyman break galaxies

    NASA Astrophysics Data System (ADS)

    Dayal, Pratika; Libeskind, Noam I.; Dunlop, James S.

    2013-06-01

    We use state-of-the-art numerical simulations to explore the observability and the expected physical properties of the progenitors of the Local Group galaxies at z ≃ 6-8, within 1 billion years of the big bang. We find that the most massive progenitors of the Milky Way (MW) and Andromeda (M31) at z ≃ 6 and 7 are predicted to have absolute ultraviolet (UV) continuum magnitudes MUV ≃ -17 to -18, suggesting that their analogues lie close to the detection limits of the deepest near-infrared (IR) surveys conducted to date [i.e. Hubble Space Telescope Wide Field Camera 3/IR Ultra Deep Field (UDF)12]. This in turn confirms that the majority of currently known z ≃ 6-8 galaxies are expected to be the seeds of present-day galaxies which are more massive than L* spirals. We also discuss the properties of the Local Group progenitors at these early epochs, extending down to absolute magnitudes MUV ≃ -13. The most massive MW/M31 progenitors at z ≃ 7 have stellar masses M* ≃ 107.5-8 M⊙, stellar metallicities Z* ˜ 3-6 per cent Z⊙, and predicted observed UV continuum slopes β ≃ -2.4 to -2.5.

  9. Nutraceutical augmentation of circulating endothelial progenitor cells and hematopoietic stem cells in human subjects.

    PubMed

    Mikirova, Nina A; Jackson, James A; Hunninghake, Ron; Kenyon, Julian; Chan, Kyle W H; Swindlehurst, Cathy A; Minev, Boris; Patel, Amit N; Murphy, Michael P; Smith, Leonard; Ramos, Famela; Ichim, Thomas E; Riordan, Neil H

    2010-04-08

    The medical significance of circulating endothelial or hematopoietic progenitors is becoming increasing recognized. While therapeutic augmentation of circulating progenitor cells using G-CSF has resulted in promising preclinical and early clinical data for several degenerative conditions, this approach is limited by cost and inability to perform chronic administration. Stem-Kine is a food supplement that was previously reported to augment circulating EPC in a pilot study. Here we report a trial in 18 healthy volunteers administered Stem-Kine twice daily for a 2 week period. Significant increases in circulating CD133 and CD34 cells were observed at days 1, 2, 7, and 14 subsequent to initiation of administration, which correlated with increased hematopoietic progenitors as detected by the HALO assay. Augmentation of EPC numbers in circulation was detected by KDR-1/CD34 staining and colony forming assays. These data suggest Stem-Kine supplementation may be useful as a stimulator of reparative processes associated with mobilization of hematopoietic and endothelial progenitors.

  10. Tmem88a mediates GATA-dependent specification of cardiomyocyte progenitors by restricting WNT signaling

    PubMed Central

    Novikov, Natasha; Evans, Todd

    2013-01-01

    Biphasic control of WNT signaling is essential during cardiogenesis, but how the pathway switches from promoting cardiac mesoderm to restricting cardiomyocyte progenitor fate is unknown. We identified genes expressed in lateral mesoderm that are dysregulated in zebrafish when both gata5 and gata6 are depleted, causing a block to cardiomyocyte specification. This screen identified tmem88a, which is expressed in the early cardiac progenitor field and was previously implicated in WNT modulation by overexpression studies. Depletion of tmem88a results in a profound cardiomyopathy, secondary to impaired cardiomyocyte specification. In tmem88a morphants, activation of the WNT pathway exacerbates the cardiomyocyte deficiency, whereas WNT inhibition rescues progenitor cells and cardiogenesis. We conclude that specification of cardiac fate downstream of gata5/6 involves activation of the tmem88a gene to constrain WNT signaling and expand the number of cardiac progenitors. Tmem88a is a novel component of the regulatory mechanism controlling the second phase of biphasic WNT activity essential for embryonic cardiogenesis. PMID:23903195

  11. Evaluating the progenitor cells of ovarian cancer: analysis of current animal models.

    PubMed

    King, Shelby M; Burdette, Joanna E

    2011-07-01

    Serous ovarian cancer is one of the most lethal gynecological malignancies. Progress on effective diagnostics and therapeutics for this disease are hampered by ambiguity as to the cellular origins of this histotype of ovarian cancer, as well as limited suitable animal models to analyze early stages of disease. In this report, we will review current animal models with respect to the two proposed progenitor cells for serous ovarian cancer, the ovarian surface epithelium and the fallopian tube epithelium.

  12. A luminous, blue progenitor system for the type Iax supernova 2012Z

    NASA Astrophysics Data System (ADS)

    McCully, Curtis; Jha, Saurabh W.; Foley, Ryan J.; Bildsten, Lars; Fong, Wen-Fai; Kirshner, Robert P.; Marion, G. H.; Riess, Adam G.; Stritzinger, Maximilian D.

    2014-08-01

    Type Iax supernovae are stellar explosions that are spectroscopically similar to some type Ia supernovae at the time of maximum light emission, except with lower ejecta velocities. They are also distinguished by lower luminosities. At late times, their spectroscopic properties diverge from those of other supernovae, but their composition (dominated by iron-group and intermediate-mass elements) suggests a physical connection to normal type Ia supernovae. Supernovae of type Iax are not rare; they occur at a rate between 5 and 30 per cent of the normal type Ia rate. The leading models for type Iax supernovae are thermonuclear explosions of accreting carbon-oxygen white dwarfs that do not completely unbind the star, implying that they are `less successful' versions of normal type Ia supernovae, where complete stellar disruption is observed. Here we report the detection of the luminous, blue progenitor system of the type Iax SN 2012Z in deep pre-explosion imaging. The progenitor system's luminosity, colours, environment and similarity to the progenitor of the Galactic helium nova V445 Puppis suggest that SN 2012Z was the explosion of a white dwarf accreting material from a helium-star companion. Observations over the next few years, after SN 2012Z has faded, will either confirm this hypothesis or perhaps show that this supernova was actually the explosive death of a massive star.

  13. A luminous, blue progenitor system for the type Iax supernova 2012Z.

    PubMed

    McCully, Curtis; Jha, Saurabh W; Foley, Ryan J; Bildsten, Lars; Fong, Wen-fai; Kirshner, Robert P; Marion, G H; Riess, Adam G; Stritzinger, Maximilian D

    2014-08-07

    Type Iax supernovae are stellar explosions that are spectroscopically similar to some type Ia supernovae at the time of maximum light emission, except with lower ejecta velocities. They are also distinguished by lower luminosities. At late times, their spectroscopic properties diverge from those of other supernovae, but their composition (dominated by iron-group and intermediate-mass elements) suggests a physical connection to normal type Ia supernovae. Supernovae of type Iax are not rare; they occur at a rate between 5 and 30 per cent of the normal type Ia rate. The leading models for type Iax supernovae are thermonuclear explosions of accreting carbon-oxygen white dwarfs that do not completely unbind the star, implying that they are 'less successful' versions of normal type Ia supernovae, where complete stellar disruption is observed. Here we report the detection of the luminous, blue progenitor system of the type Iax SN 2012Z in deep pre-explosion imaging. The progenitor system's luminosity, colours, environment and similarity to the progenitor of the Galactic helium nova V445 Puppis suggest that SN 2012Z was the explosion of a white dwarf accreting material from a helium-star companion. Observations over the next few years, after SN 2012Z has faded, will either confirm this hypothesis or perhaps show that this supernova was actually the explosive death of a massive star.

  14. Feedback control of growth, differentiation, and morphogenesis of pancreatic endocrine progenitors in an epithelial plexus niche

    PubMed Central

    Bankaitis, Eric D.; Bechard, Matthew E.; Wright, Christopher V.E.

    2015-01-01

    In the mammalian pancreas, endocrine cells undergo lineage allocation upon emergence from a bipotent duct/endocrine progenitor pool, which resides in the “trunk epithelium.” Major questions remain regarding how niche environments are organized within this epithelium to coordinate endocrine differentiation with programs of epithelial growth, maturation, and morphogenesis. We used EdU pulse-chase and tissue-reconstruction approaches to analyze how endocrine progenitors and their differentiating progeny are assembled within the trunk as it undergoes remodeling from an irregular plexus of tubules to form the eventual mature, branched ductal arbor. The bulk of endocrine progenitors is maintained in an epithelial “plexus state,” which is a transient intermediate during epithelial maturation within which endocrine cell differentiation is continually robust and surprisingly long-lived. Within the plexus, local feedback effects derived from the differentiating and delaminating endocrine cells nonautonomously regulate the flux of endocrine cell birth as well as proliferative growth of the bipotent cell population using Notch-dependent and Notch-independent influences, respectively. These feedback effects in turn maintain the plexus state to ensure prolonged allocation of endocrine cells late into gestation. These findings begin to define a niche-like environment guiding the genesis of the endocrine pancreas and advance current models for how differentiation is coordinated with the growth and morphogenesis of the developing pancreatic epithelium. PMID:26494792

  15. Sox2 acts in a dose-dependent fashion to regulate proliferation of cortical progenitors.

    PubMed

    Hagey, Daniel W; Muhr, Jonas

    2014-12-11

    Organ formation and maintenance depends on slowly self-renewing stem cells that supply an intermediate population of rapidly dividing progenitors, but how this proliferative hierarchy is regulated is unknown. By performing genome-wide single-cell and functional analyses in the cortex, we demonstrate that reduced Sox2 expression is a key regulatory signature of the transition between stem cells and rapidly dividing progenitors. In stem cells, Sox2 is expressed at high levels, which enables its repression of proproliferative genes, of which Cyclin D1 is the most potent target. Sox2 confers this function through binding to low-affinity motifs, which facilitate the recruitment of Gro/Tle corepressors in synergy with Tcf/Lef proteins. Upon differentiation, proneural factors reduce Sox2 expression, which derepresses Cyclin D1 and promotes proliferation. Our results show how concentration-dependent Sox2 occupancy of DNA motifs of varying affinities translates into recruitment of repressive complexes, which regulate the proliferative dynamics of neural stem and progenitor cells. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  16. Noninvasive Imaging of Administered Progenitor Cells

    SciTech Connect

    Steven R Bergmann, M.D., Ph.D.

    The objective of this research grant was to develop an approach for labeling progenitor cells, specifically those that we had identified as being able to replace ischemic heart cells, so that the distribution could be followed non-invasively. In addition, the research was aimed at determining whether administration of progenitor cells resulted in improved myocardial perfusion and function. The efficiency and toxicity of radiolabeling of progenitor cells was to be evaluated. For the proposed clinical protocol, subjects with end-stage ischemic coronary artery disease were to undergo a screening cardiac positron emission tomography (PET) scan using N-13 ammonia to delineate myocardial perfusionmore » and function. If they qualified based on their PET scan, they would undergo an in-hospital protocol whereby CD34+ cells were stimulated by the administration of granulocytes-colony stimulating factor (G-CSF). CD34+ cells would then be isolated by apharesis, and labeled with indium-111 oxine. Cells were to be re-infused and subjects were to undergo single photon emission computed tomography (SPECT) scanning to evaluate uptake and distribution of labeled progenitor cells. Three months after administration of progenitor cells, a cardiac PET scan was to be repeated to evaluate changes in myocardial perfusion and/or function. Indium oxine is a radiopharmaceutical for labeling of autologous lymphocytes. Indium-111 (In-111) decays by electron capture with a t{sub ½} of 67.2 hours (2.8 days). Indium forms a saturated complex that is neutral, lipid soluble, and permeates the cell membrane. Within the cell, the indium-oxyquinolone complex labels via indium intracellular chelation. Following leukocyte labeling, ~77% of the In-111 is incorporated in the cell pellet. The presence of red cells and /or plasma reduces the labeling efficacy. Therefore, the product needed to be washed to eliminate plasma proteins. This repeated washing can damage cells. The CD34 selected product was a

  17. l-Arginine is a Radioprotector for Hematopoietic Progenitor Cells

    PubMed Central

    Pearce, Linda L.; Zheng, Xichen; Martinez-Bosch, Sandra; Kerr, Patrick P.; Khlangwiset, Pornsri; Epperly, Michael W.; Fink, Mitchell P.; Greenberger, Joel S.; Peterson, Jim

    2012-01-01

    l-Arginine is shown to protect hematopoietic progenitor (32D cl 3) cells from death due to exposure to γ radiation (137Cs). Some of the other intermediates in the urea cycle, namely ornithine and citrulline, plus urea itself, were not found to have any significant impact on cell survival after irradiation. Intriguingly, supplementation of irradiated cells with l-arginine results in decreased production of peroxynitrite, suggesting that suppression of superoxide generation by nitric oxide synthase in one or more microenvironments is an important factor in the observed radioprotection. The absence of any radioprotective effect of l-arginine in cells at 3% oxygen also confirms the involvement of one or more oxygen-derived species. Knockdown experiments with nitric oxide synthase (NOS) siRNAs in cells and NOS knockout animals confirm that the observed radioprotection is associated with nNOS (NOS-1). l-Arginine also ameliorates the transient inhibition of the electron-transport chain complex I that occurs within 30 min of completing the dose (10 Gy) and that appears to be a functional marker for postirradiation mitochondrial oxidant production. PMID:22175298

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

    PubMed

    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.

  19. Molecular Mechanisms of Stem/Progenitor Cell Maintenance in the Adrenal Cortex

    PubMed Central

    Lerario, Antonio Marcondes; Finco, Isabella; LaPensee, Christopher; Hammer, Gary Douglas

    2017-01-01

    The adrenal cortex is characterized by three histologically and functionally distinct zones: the outermost zona glomerulosa (zG), the intermediate zona fasciculata, and the innermost zona reticularis. Important aspects of the physiology and maintenance of the adrenocortical stem/progenitor cells have emerged in the last few years. Studies have shown that the adrenocortical cells descend from a pool of progenitors that are localized in the subcapsular region of the zG. These cells continually undergo a process of centripetal displacement and differentiation, which is orchestrated by several paracrine and endocrine cues, including the pituitary-derived adrenocorticotrophic hormone, and angiotensin II. However, while several roles of the endocrine axes on adrenocortical function are well established, the mechanisms coordinating the maintenance of an undifferentiated progenitor cell pool with self-renewal capacity are poorly understood. Local factors, such as the composition of the extracellular matrix (ECM) with embedded signaling molecules, and the activity of major paracrine effectors, including ligands of the sonic hedgehog and Wnt signaling pathways, are thought to play a major role. Particularly, the composition of the ECM, which exhibits substantial differences within each of the three histologically distinct concentric zones, has been shown to influence the differentiation status of adrenocortical cells. New data from other organ systems and different experimental paradigms strongly support the conclusion that the interactions of ECM components with cell-surface receptors and secreted factors are key determinants of cell fate. In this review, we summarize established and emerging data on the paracrine and autocrine regulatory loops that regulate the biology of the progenitor cell niche and propose a role for bioengineered ECM models in further elucidating this biology in the adrenal. PMID:28386245

  20. Endothelial cells are not required for specification of respiratory progenitors

    PubMed Central

    Havrilak, Jamie A.; Melton, Kristin R.; Shannon, John M.

    2017-01-01

    Crosstalk between mesenchymal and epithelial cells influences organogenesis in multiple tissues, such as lung, pancreas, liver, and the nervous system. Lung mesenchyme comprises multiple cell types, however, and precise identification of the mesenchymal cell type(s) that drives early events in lung development remains unknown. Endothelial cells have been shown to be required for some aspects of lung epithelial patterning, lung stem cell differentiation, and regeneration after injury. Furthermore, endothelial cells are involved in early liver and pancreas development. From these observations we hypothesized that endothelial cells might also be required for early specification of the respiratory field and subsequent lung bud initiation. We first blocked VEGF signaling in E8.5 cultured foreguts with small molecule VEGFR inhibitors and found that lung specification and bud formation were unaltered. However, when we examined E9.5 mouse embryos carrying a mutation in the VEGFR Flk-1, which do not develop endothelial cells, we found that respiratory progenitor specification was impeded. Because the E9.5 embryos were substantially smaller than control littermates, suggesting the possibility of developmental delay, we isolated and cultured foreguts from mutant and control embryos on E8.5, when no size differences were apparent. We found that both specification of the respiratory field and lung bud formation occurred in mutant and control explants. These observations were unaffected by the presence or absence of serum. We also observed that hepatic specification and initiation occurred in the absence of endothelial cells, and that expansion of the liver epithelium in culture did not differ between mutant and control explants. Consistent with previously published results, we also found that pancreatic buds were not maintained in cultured foreguts when endothelial cells were absent. Our observations support the conclusion that endothelial cells are not required for early

  1. Prognostic value of circulating VEGFR2+ bone marrow-derived progenitor cells in patients with advanced cancer.

    PubMed

    Massard, Christophe; Borget, Isabelle; Le Deley, Marie Cécile; Taylor, Melissa; Gomez-Roca, Carlos; Soria, Jean Charles; Farace, Françoise

    2012-06-01

    We hypothesised that host-related markers, possibly reflecting tumour aggressiveness, such as circulating endothelial cells (CEC) and circulating VEGFR2(+) bone marrow-derived (BMD) progenitor cells, could have prognostic value in patients with advanced cancer enrolled in early anticancer drug development trials. Baseline CECs (CD45(-)CD31(+)CD146(+)7AAD(-) cells) and circulating VEGFR2(+)-BMD progenitor cells (defined as CD45(dim)CD34(+)VEGFR2(+)7AAD(-) cells) were measured by flow-cytometry in 71 and 58 patients included in phase 1 trials testing novel anti-vascular or anti-angiogenic agents. Correlations between levels of CECs, circulating VEGFR2(+)-BMD progenitor cells, clinical and biological prognostic factors (i.e. the Royal Marsden Hospital (RMH) score), and overall survival (OS) were studied. The median value of CECs was 12 CEC/ml (range 0-154/ml). The median level of VEGFR2(+)-BMD progenitor cells was 1.3% (range 0-32.5%) of circulating BMD-CD34(+) progenitors. While OS was not correlated with CEC levels, it was significantly worse in patients with high VEGFR2(+)-BMD progenitor levels (>1%) (median OS 9.0 versus 17.0 months), and with a RMH prognostic score >0 (median OS 9.0 versus 24.2 months). The prognostic value of VEGFR2(+)-BMD progenitor levels remained significant (hazard ratio (HR) = 2.3, 95% confidence interval (CI), 1.1-4.6, p = 0.02) after multivariate analysis. A composite VEGFR2(+)-BMD progenitor level/RHM score ≥ 2 was significantly associated with an increased risk of death compared to scores of 0 or 1 (median OS 9.0 versus 18.4 months, HR = 2.6 (95%CI, 1.2-5.8, p = 0.02)). High circulating VEGFR2(+)-BMD progenitor levels are associated with poor prognostics and when combined to classical clinical and biological parameters could provide a new tool for patient selection in early anticancer drug trials. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

    PubMed

    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.

  3. Creatine supports propagation and promotes neuronal differentiation of inner ear progenitor cells.

    PubMed

    Di Santo, Stefano; Mina, Amir; Ducray, Angélique; Widmer, Hans R; Senn, Pascal

    2014-05-07

    Long-term propagation of inner ear-derived progenitor/stem cells beyond the third generation and differentiation into inner ear cell types has been shown to be feasible, but challenging. We investigated whether the known neuroprotective guanidine compound creatine (Cr) promotes propagation of inner ear progenitor/stem cells as mitogen-expanded neurosphere cultures judged from the formation of spheres over passages. In addition, we studied whether Cr alone or in combination with brain-derived neurotrophic factor (BDNF) promotes neuronal differentiation of inner ear progenitors. For this purpose, early postnatal rat spiral ganglia, utricle, and organ of Corti-derived progenitors were grown as floating spheres in the absence (controls) or presence of Cr (5 mM) from passage 3 onward. Similarly, dissociated sphere-derived cultures were differentiated for 14 days in the presence or absence of Cr (5 mM) and spiral ganglia sphere-derived cultures in a combination of Cr with the neurotrophin BDNF (50 ng/ml). We found that the cumulative total number of spheres over all passages was significantly higher after Cr supplementation as compared with controls in all the three inner ear cultures. In contrast, sphere sizes were not affected by the administration of Cr. Administration of Cr during differentiation of spiral ganglia cells resulted in a significantly higher density of β-III-tubulin-positive cells compared with controls, whereas densities of myosin VIIa-positive cells in cultures of utricle and organ of Corti were not affected by the treatment. Importantly, a combination of Cr with the neurotrophin BDNF resulted in further significantly increased densities of β-III-tubulin-positive cells in cultures of spiral ganglia cells as compared with single treatments. In sum, Cr promoted continuing propagation of rat inner ear-derived progenitor cells and supported specifically in combination with BDNF the differentiation of neuronal cell types from spiral ganglion

  4. Germinal zones in the developing cerebral cortex of ferret: ontogeny, cell cycle kinetics, and diversity of progenitors.

    PubMed

    Reillo, Isabel; Borrell, Víctor

    2012-09-01

    Expansion and folding of the cerebral cortex are landmark features of mammalian brain evolution. This is recapitulated during embryonic development, and specialized progenitor cell populations known as intermediate radial glia cells (IRGCs) are believed to play central roles. Because developmental mechanisms involved in cortical expansion and folding are likely conserved across phylogeny, it is crucial to identify features specific for gyrencephaly from those unique to primate brain development. Here, we studied multiple features of cortical development in ferret, a gyrencephalic carnivore, in comparison with primates. Analyzing the combinatorial expression of transcription factors, cytoskeletal proteins, and cell cycle parameters, we identified a combination of traits that distinguish in ferret similar germinal layers as in primates. Transcription factor analysis indicated that inner subventricular zone (ISVZ) and outer subventricular zone (OSVZ) may contain an identical mixture of progenitor cell subpopulations in ferret. However, we found that these layers emerge at different time points, differ in IRGC abundance, and progenitors have different cell cycle kinetics and self-renewal dynamics. Thus, ISVZ and OSVZ are likely distinguished by genetic differences regulating progenitor cell behavior and dynamics. Our findings demonstrate that some, but not all, features of primate cortical development are shared by the ferret, suggesting a conserved role in the evolutionary emergence of gyrencephaly.

  5. The Vagal Nerve Stimulates Activation of the Hepatic Progenitor Cell Compartment via Muscarinic Acetylcholine Receptor Type 3

    PubMed Central

    Cassiman, David; Libbrecht, Louis; Sinelli, Nicoletta; Desmet, Valeer; Denef, Carl; Roskams, Tania

    2002-01-01

    In the rat the hepatic branch of the nervus vagus stimulates proliferation of hepatocytes after partial hepatectomy and growth of bile duct epithelial cells after bile duct ligation. We studied the effect of hepatic vagotomy on the activation of the hepatic progenitor cell compartment in human and rat liver. The number of hepatic progenitor cells and atypical reactive ductular cells in transplanted (denervated) human livers with hepatitis was significantly lower than in innervated matched control livers and the number of oval cells in vagotomized rat livers with galactosamine hepatitis was significantly lower than in livers of sham-operated rats with galactosamine hepatitis. The expression of muscarinic acetylcholine receptors (M1-M5 receptor) was studied by immunohistochemistry and reverse transcriptase-polymerase chain reaction. In human liver, immunoreactivity for M3 receptor was observed in hepatic progenitor cells, atypical reactive ductules, intermediate hepatocyte-like cells, and bile duct epithelial cells. mRNA for the M1-M3 and the M5 receptor, but not the M4 receptor, was detected in human liver homogenates. In conclusion, the hepatic vagus branch stimulates activation of the hepatic progenitor cell compartment in diseased liver, most likely through binding of acetylcholine to the M3 receptor expressed on these cells. These findings may be of clinical importance for patients with a transplant liver. PMID:12163377

  6. Effect of hyperglycemia on the number of CD117+ progenitor cells and their differentiation toward endothelial progenitor cells in young and old ages.

    PubMed

    Pierpaoli, Elisa; Moresi, Raffaella; Orlando, Fiorenza; Malavolta, Marco; Provinciali, Mauro

    2016-10-01

    Dysfunction of endothelial progenitor cells (EPCs) has been reported either in aging or diabetes, though the influence of an "old" environment on numerical and functional changes of diabetes associated EPCs is not known. We evaluated the effect of both aging and early stage of streptozotocin-induced diabetes on the number of bone marrow-derived CD117 + progenitor cells, and on their differentiation in vitro toward EPCs. The phenotype of progenitor cells and the uptake of acetylated-low density lipoprotein (Ac-LDL) were evaluated after cell culture in VEGF, FGF-1, and IGF-1 supplemented medium. Hyperglycemia similarly reduced the number of CD117 + cells both in young and old mice. CD117 + cells from young mice differentiated better than those from old animals "in vitro", with a greater reduction of CD117 + cells and an higher increase of CD184 + VEGFR-2 + cells. In diabetic mice, in vitro CD117 + cells differentiation was significantly reduced in young animals. Diabetes did not impact on the scarce differentiation of CD117 + cells from old mice. Hyperglycemia reduced the uptake of acLDL by EPCs greatly in young than in old mice. These findings indicate that part of the EPCs functional alterations induced by hyperglicemia in young mice are observed in normal aged mice. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  7. Progenitors of low-luminosity Type II-Plateau supernovae

    NASA Astrophysics Data System (ADS)

    Lisakov, Sergey M.; Dessart, Luc; Hillier, D. John; Waldman, Roni; Livne, Eli

    2018-01-01

    The progenitors of low-luminosity Type II-Plateau supernovae (SNe II-P) are believed to be red supergiant (RSG) stars, but there is much disparity in the literature concerning their mass at core collapse and therefore on the main sequence. Here, we model the SN radiation arising from the low-energy explosion of RSG stars of 12, 25 and 27 M⊙ on the main sequence and formed through single star evolution. Despite the narrow range in ejecta kinetic energy (2.5-4.2 × 1050 erg) in our model set, the SN observables from our three models are significantly distinct, reflecting the differences in progenitor structure (e.g. surface radius, H-rich envelope mass and He-core mass). Our higher mass RSG stars give rise to Type II SNe that tend to have bluer colours at early times, a shorter photospheric phase, and a faster declining V-band light curve (LC) more typical of Type II-linear SNe, in conflict with the LC plateau observed for low-luminosity SNe II. The complete fallback of the CO core in the low-energy explosions of our high-mass RSG stars prevents the ejection of any 56Ni (nor any core O or Si), in contrast to low-luminosity SNe II-P, which eject at least 0.001 M⊙ of 56Ni. In contrast to observations, Type II SN models from higher mass RSGs tend to show an H α absorption that remains broad at late times (due to a larger velocity at the base of the H-rich envelope). In agreement with the analyses of pre-explosion photometry, we conclude that low-luminosity SNe II-P likely arise from low-mass rather than high-mass RSG stars.

  8. Progressive Recruitment of Mesenchymal Progenitors Reveals a Time-Dependent Process of Cell Fate Acquisition in Mouse and Human Nephrogenesis.

    PubMed

    Lindström, Nils O; De Sena Brandine, Guilherme; Tran, Tracy; Ransick, Andrew; Suh, Gio; Guo, Jinjin; Kim, Albert D; Parvez, Riana K; Ruffins, Seth W; Rutledge, Elisabeth A; Thornton, Matthew E; Grubbs, Brendan; McMahon, Jill A; Smith, Andrew D; McMahon, Andrew P

    2018-06-04

    Mammalian nephrons arise from a limited nephron progenitor pool through a reiterative inductive process extending over days (mouse) or weeks (human) of kidney development. Here, we present evidence that human nephron patterning reflects a time-dependent process of recruitment of mesenchymal progenitors into an epithelial nephron precursor. Progressive recruitment predicted from high-resolution image analysis and three-dimensional reconstruction of human nephrogenesis was confirmed through direct visualization and cell fate analysis of mouse kidney organ cultures. Single-cell RNA sequencing of the human nephrogenic niche provided molecular insights into these early patterning processes and predicted developmental trajectories adopted by nephron progenitor cells in forming segment-specific domains of the human nephron. The temporal-recruitment model for nephron polarity and patterning suggested by direct analysis of human kidney development provides a framework for integrating signaling pathways driving mammalian nephrogenesis. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. Transfusion Support for ABO-Incompatible Progenitor Cell Transplantation

    PubMed Central

    Kopko, Patricia M.

    2016-01-01

    Summary ABO-incompatible transplants comprise up to 50% of allogeneic progenitor cell transplants. Major, minor and bidirectional ABO-incompatible transplants each have unique complications that can occur, including hemolysis at the time of progenitor cell infusion, hemolysis during donor engraftment, passenger lymphocyte syndrome, delayed red blood cell engraftment, and pure red cell aplasia. Appropriate transfusion support during the different phases of the allogeneic progenitor cell transplant process is an important part of ABO-incompatible transplantation. PMID:27022318

  10. Interleukin-7-induced Stat-5 acts in synergy with Flt-3 signaling to stimulate expansion of hematopoietic progenitor cells.

    PubMed

    Åhsberg, Josefine; Tsapogas, Panagiotis; Qian, Hong; Zetterblad, Jenny; Zandi, Sasan; Månsson, Robert; Jönsson, Jan-Ingvar; Sigvardsson, Mikael

    2010-11-19

    The development of lymphoid cells from bone marrow progenitors is dictated by interplay between internal cues such as transcription factors and external signals like the cytokines Flt-3 ligand and Il-7. These proteins are both of large importance for normal lymphoid development; however, it is unclear if they act in direct synergy to expand a transient Il-7R(+)Flt-3(+) population or if the collaboration is created through sequential activities. We report here that Flt-3L and Il-7 synergistically stimulated the expansion of primary Il-7R(+)Flt-3(+) progenitor cells and a hematopoietic progenitor cell line ectopically expressing the receptors. The stimulation resulted in a reduced expression of pro-apoptotic genes and also mediated survival of primary progenitor cells in vitro. However, functional analysis of single cells suggested that the anti-apoptotic effect was additive indicating that the synergy observed mainly depends on stimulation of proliferation. Analysis of downstream signaling events suggested that although Il-7 induced Stat-5 phosphorylation, Flt-3L caused activation of the ERK and AKT signaling pathways. Flt-3L could also drive proliferation in synergy with ectopically expressed constitutively active Stat-5. This synergy could be inhibited with either receptor tyrosine kinase or MAPK inhibitors suggesting that Flt-3L and Il-7 act in synergy by activation of independent signaling pathways to expand early hematopoietic progenitors.

  11. Nuclear Orphan Receptor TLX Induces Oct-3/4 for the Survival and Maintenance of Adult Hippocampal Progenitors upon Hypoxia*

    PubMed Central

    Chavali, Pavithra Lakshminarasimhan; Saini, Ravi Kanth Rao; Matsumoto, Yoshiki; Ågren, Hans; Funa, Keiko

    2011-01-01

    Hypoxia promotes neural stem cell proliferation, the mechanism of which is poorly understood. Here, we have identified the nuclear orphan receptor TLX as a mediator for proliferation and pluripotency of neural progenitors upon hypoxia. We found an enhanced early protein expression of TLX under hypoxia potentiating sustained proliferation of neural progenitors. Moreover, TLX induction upon hypoxia in differentiating conditions leads to proliferation and a stem cell-like phenotype, along with coexpression of neural stem cell markers. Following hypoxia, TLX is recruited to the Oct-3/4 proximal promoter, augmenting the gene transcription and promoting progenitor proliferation and pluripotency. Knockdown of Oct-3/4 significantly reduced TLX-mediated proliferation, highlighting their interdependence in regulating the progenitor pool. Additionally, TLX synergizes with basic FGF to sustain cell viability upon hypoxia, since the knockdown of TLX along with the withdrawal of growth factor results in cell death. This can be attributed to the activation of Akt signaling pathway by TLX, the depletion of which results in reduced proliferation of progenitor cells. Cumulatively, the data presented here demonstrate a new role for TLX in neural stem cell proliferation and pluripotency upon hypoxia. PMID:21135096

  12. Nuclear orphan receptor TLX induces Oct-3/4 for the survival and maintenance of adult hippocampal progenitors upon hypoxia.

    PubMed

    Chavali, Pavithra Lakshminarasimhan; Saini, Ravi Kanth Rao; Matsumoto, Yoshiki; Ågren, Hans; Funa, Keiko

    2011-03-18

    Hypoxia promotes neural stem cell proliferation, the mechanism of which is poorly understood. Here, we have identified the nuclear orphan receptor TLX as a mediator for proliferation and pluripotency of neural progenitors upon hypoxia. We found an enhanced early protein expression of TLX under hypoxia potentiating sustained proliferation of neural progenitors. Moreover, TLX induction upon hypoxia in differentiating conditions leads to proliferation and a stem cell-like phenotype, along with coexpression of neural stem cell markers. Following hypoxia, TLX is recruited to the Oct-3/4 proximal promoter, augmenting the gene transcription and promoting progenitor proliferation and pluripotency. Knockdown of Oct-3/4 significantly reduced TLX-mediated proliferation, highlighting their interdependence in regulating the progenitor pool. Additionally, TLX synergizes with basic FGF to sustain cell viability upon hypoxia, since the knockdown of TLX along with the withdrawal of growth factor results in cell death. This can be attributed to the activation of Akt signaling pathway by TLX, the depletion of which results in reduced proliferation of progenitor cells. Cumulatively, the data presented here demonstrate a new role for TLX in neural stem cell proliferation and pluripotency upon hypoxia.

  13. Identification of Three Molecular and Functional Subtypes in Canine Hemangiosarcoma through Gene Expression Profiling and Progenitor Cell Characterization

    PubMed Central

    Gorden, Brandi H.; Kim, Jong-Hyuk; Sarver, Aaron L.; Frantz, Aric M.; Breen, Matthew; Lindblad-Toh, Kerstin; O'Brien, Timothy D.; Sharkey, Leslie C.; Modiano, Jaime F.; Dickerson, Erin B.

    2015-01-01

    Canine hemangiosarcomas have been ascribed to an endothelial origin based on histologic appearance; however, recent findings suggest that these tumors may arise instead from hematopoietic progenitor cells. To clarify this ontogenetic dilemma, we used genome-wide expression profiling of primary hemangiosarcomas and identified three distinct tumor subtypes associated with angiogenesis (group 1), inflammation (group 2), and adipogenesis (group 3). Based on these findings, we hypothesized that a common progenitor may differentiate into the three tumor subtypes observed in our gene profiling experiment. To investigate this possibility, we cultured hemangiosarcoma cell lines under normal and sphere-forming culture conditions to enrich for tumor cell progenitors. Cells from sphere-forming cultures displayed a robust self-renewal capacity and exhibited genotypic, phenotypic, and functional properties consistent with each of the three molecular subtypes seen in primary tumors, including expression of endothelial progenitor cell (CD133 and CD34) and endothelial cell (CD105, CD146, and αvβ3 integrin) markers, expression of early hematopoietic (CD133, CD117, and CD34) and myeloid (CD115 and CD14) differentiation markers in parallel with increased phagocytic capacity, and acquisition of adipogenic potential. Collectively, these results suggest that canine hemangiosarcomas arise from multipotent progenitors that differentiate into distinct subtypes. Improved understanding of the mechanisms that determine the molecular and phenotypic differentiation of tumor cells in vivo could change paradigms regarding the origin and progression of endothelial sarcomas. PMID:24525151

  14. Identification of three molecular and functional subtypes in canine hemangiosarcoma through gene expression profiling and progenitor cell characterization.

    PubMed

    Gorden, Brandi H; Kim, Jong-Hyuk; Sarver, Aaron L; Frantz, Aric M; Breen, Matthew; Lindblad-Toh, Kerstin; O'Brien, Timothy D; Sharkey, Leslie C; Modiano, Jaime F; Dickerson, Erin B

    2014-04-01

    Canine hemangiosarcomas have been ascribed to an endothelial origin based on histologic appearance; however, recent findings suggest that these tumors may arise instead from hematopoietic progenitor cells. To clarify this ontogenetic dilemma, we used genome-wide expression profiling of primary hemangiosarcomas and identified three distinct tumor subtypes associated with angiogenesis (group 1), inflammation (group 2), and adipogenesis (group 3). Based on these findings, we hypothesized that a common progenitor may differentiate into the three tumor subtypes observed in our gene profiling experiment. To investigate this possibility, we cultured hemangiosarcoma cell lines under normal and sphere-forming culture conditions to enrich for tumor cell progenitors. Cells from sphere-forming cultures displayed a robust self-renewal capacity and exhibited genotypic, phenotypic, and functional properties consistent with each of the three molecular subtypes seen in primary tumors, including expression of endothelial progenitor cell (CD133 and CD34) and endothelial cell (CD105, CD146, and αvβ3 integrin) markers, expression of early hematopoietic (CD133, CD117, and CD34) and myeloid (CD115 and CD14) differentiation markers in parallel with increased phagocytic capacity, and acquisition of adipogenic potential. Collectively, these results suggest that canine hemangiosarcomas arise from multipotent progenitors that differentiate into distinct subtypes. Improved understanding of the mechanisms that determine the molecular and phenotypic differentiation of tumor cells in vivo could change paradigms regarding the origin and progression of endothelial sarcomas. Copyright © 2014 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  15. Progenitor cell dose determines the pace and completeness of engraftment in a xenograft model for cord blood transplantation

    PubMed Central

    Liu, Congxiao; Chen, Benny J.; DeOliveira, Divinomar; Sempowski, Gregory D.; Chao, Nelson J.

    2010-01-01

    Two critical concerns in clinical cord blood transplantation are the initial time to engraftment and the subsequent restoration of immune function. These studies measured the impact of progenitor cell dose on both the pace and strength of hematopoietic reconstitution by transplanting nonobese diabetic/severe combined immunodeficiency/interleukin-2 receptor-gamma–null (NSγ) mice with lineage-depleted aldehyde dehydrogenase-bright CD34+ human cord blood progenitors. The progress of each transplant was monitored over an extended time course by repeatedly analyzing the peripheral blood for human hematopoietic cells. In vivo human hematopoietic development was complete. After long-term transplantation assays (≥ 19 weeks), human T-cell development was documented within multiple tissues in 16 of 32 NSγ mice. Human T-cell differentiation was active within NSγ thymuses, as documented by the presence of CD4+ CD8+ T-cell progenitors as well as T-cell receptor excision circles. It is important to note that although myeloid and B-cell engraftment was detected as early as 4 weeks after transplantation, human T-cell development was exclusively late onset. High progenitor cell doses were associated with a robust human hematopoietic chimerism that accelerated both initial time to engraftment and subsequent T-cell development. At lower progenitor cell doses, the chimerism was weak and the human hematopoietic lineage development was frequently incomplete. PMID:20833978

  16. Distinct roles for the 5' and 3' untranslated regions in the degradation and accumulation of chloroplast tufA mRNA: identification of an early intermediate in the in vivo degradation pathway.

    PubMed

    Zicker, Alicia A; Kadakia, Crystal S; Herrin, David L

    2007-03-01

    Elongation factor Tu in Chlamydomonas reinhardtii is a chloroplast-encoded gene (tufA) whose 1.7-kb mRNA has a relatively short half-life. In the presence of chloramphenicol (CAP), which freezes translating chloroplast ribosomes, a 1.5-kb tufA RNA becomes prominent. Rifampicin-chase analysis indicates that the 1.5-kb RNA is a degradation intermediate, and mapping studies show that it is missing 176-180 nucleotides from the 5' end of tufA. The 5' terminus of the intermediate maps to a section of the untranslated region (UTR) predicted to be highly structured and to encode a small ORF. The intermediate could be detected in older cultures in the absence of CAP, indicating that it is not an artifact of drug treatment. Also, it did not overaccumulate in the chloroplast ribosome-deficient mutant, ac20 cr1, indicating its stabilization is specific to elongation-arrested ribosomes. To determine if the 5' UTR of tufA is destabilizing, the corresponding region of the atpA-aadA-rbcL gene was replaced with the tufA sequence, and introduced into the chloroplast genome; the 3' UTR was also substituted for comparison. Analysis of these transformants showed that the transcripts containing the tufA 3'-UTR accumulate to significantly lower levels. Data from constructs based on the vital reporter, Renilla luciferase, confirmed the importance of the tufA 3'-UTR in determining RNA levels, and suggested that the 5' UTR of tufA affects translation efficiency. These data indicate that the in vivo degradation of tufA mRNA begins in the 5' UTR, and is promoted by translation. The data also suggest, however, that the level of the mature RNA is determined more by the 3' UTR than the 5' UTR.

  17. Identification of distinct telencephalic progenitor pools for neuronal diversity in the amygdala

    PubMed Central

    Hirata, Tsutomu; Li, Peijun; Lanuza, Guillermo M.; Cocas, Laura A.; Huntsman, Molly M.; Corbin, Joshua G.

    2009-01-01

    Development of the amygdala, a central structure of the limbic system, remains poorly understood. Using mouse as a model, our studies reveal that two spatially distinct and early specified telencephalic progenitor pools marked by the homeodomain transcription factor Dbx1 are major sources of neuronal cell diversity in the mature amygdala. We find that Dbx1+ cells of the ventral pallium (VP) generate excitatory neurons of the basolateral complex and cortical amygdala nuclei. Moreover, Dbx1-derived cells comprise a novel migratory stream that emanates from the preoptic area (POA), a ventral telencephalic domain adjacent to the diencephalic border. The Dbx1+ POA-derived population migrates specifically to the amygdala, and as defined by both immunochemical and electrophysiological criteria, generates a unique subclass of inhibitory neurons in the medial amygdala nucleus. Thus, this POA-derived population represents a novel progenitor pool dedicated to the limbic system. PMID:19136974

  18. Identification of distinct telencephalic progenitor pools for neuronal diversity in the amygdala.

    PubMed

    Hirata, Tsutomu; Li, Peijun; Lanuza, Guillermo M; Cocas, Laura A; Huntsman, Molly M; Corbin, Joshua G

    2009-02-01

    The development of the amygdala, a central structure of the limbic system, remains poorly understood. We found that two spatially distinct and early-specified telencephalic progenitor pools marked by the homeodomain transcription factor Dbx1 are major sources of neuronal cell diversity in the mature mouse amygdala. We found that Dbx1-positive cells of the ventral pallium generate the excitatory neurons of the basolateral complex and cortical amygdala nuclei. Moreover, Dbx1-derived cells comprise a previously unknown migratory stream that emanates from the preoptic area (POA), a ventral telencephalic domain adjacent to the diencephalic border. The Dbx1-positive, POA-derived population migrated specifically to the amygdala and, as defined by both immunochemical and electrophysiological criteria, generated a unique subclass of inhibitory neurons in the medial amygdala nucleus. Thus, this POA-derived population represents a previously unknown progenitor pool dedicated to the limbic system.

  19. CONSTRAINING THE SPIN-DOWN TIMESCALE OF THE WHITE DWARF PROGENITORS OF TYPE Ia SUPERNOVAE

    SciTech Connect

    Meng, Xiangcun; Podsiadlowski, Philipp, E-mail: xiangcunmeng@hotmail.com

    2013-12-01

    Justham and Di Stefano et al. proposed that the white dwarf progenitor of a Type Ia supernova (SN Ia) may have to spin down before it can explode. As the white dwarf spin-down timescale is not well known theoretically, here we try to constrain it empirically (within the framework of this spin-down model) for progenitor systems that contain a giant donor and for which circumbinary material has been detected after the explosion: we obtain an upper limit of a few 10{sup 7}yr. Based on the study of Di Stefano and Kilic, this means that it is too early to rulemore » out the existence of a surviving companion in SNR 0509–67.5.« less

  20. IL-7Rα and E47: independent pathways required for development of multipotent lymphoid progenitors

    PubMed Central

    Kee, Barbara L.; Bain, Gretchen; Murre, Cornelis

    2002-01-01

    Mice that lack the transcription factors encoded by the E2A gene or the receptor for interleukin 7 (IL-7R) have severe overlapping defects in lymphocyte development. Here, we show that E2A proteins are required for the survival of early T-lineage cells; however, they function through a pathway that is distinct from the survival pathway initiated by IL-7R signaling. While E2A proteins are required to suppress caspase 3 activation, ectopic expression of the anti-apoptotic protein Bcl-2 is not sufficient to overcome the lymphopoietic defects observed in the absence of E2A. Remarkably, mice that lack both IL-7Rα and E47 display a synergistic decrease in the number of T-cell, NK-cell and multipotent progenitors in the thymus, indicating that these distinct survival pathways converge to promote the development of multipotent lymphoid progenitors. PMID:11782430

  1. Requirement for Pdx1 in specification of latent endocrine progenitors in zebrafish

    PubMed Central

    2011-01-01

    Background Insulin-producing beta cells emerge during pancreas development in two sequential waves. Recently described later-forming beta cells in zebrafish show high similarity to second wave mammalian beta cells in developmental capacity. Loss-of-function studies in mouse and zebrafish demonstrated that the homeobox transcription factors Pdx1 and Hb9 are both critical for pancreas and beta cell development and discrete stage-specific requirements for these genes have been uncovered. Previously, exocrine and endocrine cell recovery was shown to follow loss of pdx1 in zebrafish, but the progenitor cells and molecular mechanisms responsible have not been clearly defined. In addition, interactions of pdx1 and hb9 in beta cell formation have not been addressed. Results To learn more about endocrine progenitor specification, we examined beta cell formation following morpholino-mediated depletion of pdx1 and hb9. We find that after early beta cell reduction, recovery occurs following loss of either pdx1 or hb9 function. Unexpectedly, simultaneous knockdown of both hb9 and pdx1 leads to virtually complete and persistent beta cell deficiency. We used a NeuroD:EGFP transgenic line to examine endocrine cell behavior in vivo and developed a novel live-imaging technique to document emergence and migration of late-forming endocrine precursors in real time. Our data show that Notch-responsive progenitors for late-arising endocrine cells are predominantly post mitotic and depend on pdx1. By contrast, early-arising endocrine cells are specified and differentiate independent of pdx1. Conclusions The nearly complete beta cell deficiency after combined loss of hb9 and pdx1 suggests functional cooperation, which we clarify as distinct roles in early and late endocrine cell formation. A novel imaging approach permitted visualization of the emergence of late endocrine cells within developing embryos for the first time. We demonstrate a pdx1-dependent progenitor population essential for

  2. Analysis of gene expression and Ig transcription in PU.1/Spi-B-deficient progenitor B cell lines.

    PubMed

    Schweitzer, Brock L; DeKoter, Rodney P

    2004-01-01

    A number of presumptive target genes for the Ets-family transcription factor PU.1 have been identified in the B cell lineage. However, the precise function of PU.1 in B cells has not been studied because targeted null mutation of the PU.1 gene results in a block to lymphomyeloid development at an early developmental stage. In this study, we take advantage of recently developed PU.1(-/-)Spi-B(-/-) IL-7 and stromal cell-dependent progenitor B (pro-B) cell lines to analyze the function of PU.1 and Spi-B in B cell development. We show that contrary to previously published expectations, PU.1 and/or Spi-B are not required for Ig H chain (IgH) gene transcription in pro-B cells. In fact, PU.1(-/-)Spi-B(-/-) pro-B cells have increased levels of IgH transcription compared with wild-type pro-B cells. In addition, high levels of Igkappa transcription are induced after IL-7 withdrawal of wild-type or PU.1(-/-)Spi-B(-/-) pro-B cells. In contrast, we found that Iglambda transcription is reduced in PU.1(-/-)Spi-B(-/-) pro-B cells relative to wild-type pro-B cells after IL-7 withdrawal. These results suggest that Iglambda, but not IgH or Igkappa, transcription, is dependent on PU.1 and/or Spi-B. The PU.1(-/-)Spi-B(-/-) pro-B cells have other phenotypic changes relative to wild-type pro-B cells including increased proliferation, increased CD25 expression, decreased c-Kit expression, and decreased RAG-1 expression. Taken together, our observations suggest that reduction of PU.1 and/or Spi-B activity in pro-B cells promotes their differentiation to a stage intermediate between late pro-B cells and large pre-B cells.

  3. Morphine Modulates Adult Neurogenesis and Contextual Memory by Impeding the Maturation of Neural Progenitors.

    PubMed

    Zhang, Yue; Xu, Chi; Zheng, Hui; Loh, Horace H; Law, Ping-Yee

    2016-01-01

    The regulation of adult neurogenesis by opiates has been implicated in modulating different addiction cycles. At which neurogenesis stage opiates exert their action remains unresolved. We attempt to define the temporal window of morphine's inhibition effect on adult neurogenesis by using the POMC-EGFP mouse model, in which newborn granular cells (GCs) can be visualized between days 3-28 post-mitotic. The POMC-EGFP mice were trained under the 3-chambers conditioned place preference (CPP) paradigm with either saline or morphine. We observed after 4 days of CPP training with saline, the number of EGFP-labeled newborn GCs in sub-granular zone (SGZ) hippocampus significantly increased compared to mice injected with saline in their homecage. CPP training with morphine significantly decreased the number of EGFP-labeled GCs, whereas no significant difference in the number of EGFP-labeled GCs was observed with the homecage mice injected with the same dose of morphine. Using cell-type selective markers, we observed that morphine reduced the number of late stage progenitors and immature neurons such as Doublecortin (DCX) and βIII Tubulin (TuJ1) positive cells in the SGZ but did not reduce the number of early progenitors such as Nestin, SOX2, or neurogenic differentiation-1 (NeuroD1) positive cells. Analysis of co-localization between different cell markers shows that morphine reduced the number of adult-born GCs by interfering with differentiation of early progenitors, but not by inducing apoptosis. In addition, when NeuroD1 was over-expressed in DG by stereotaxic injection of lentivirus, it rescued the loss of immature neurons and prolonged the extinction of morphine-trained CPP. These results suggest that under the condition of CPP training paradigm, morphine affects the transition of neural progenitor/stem cells to immature neurons via a mechanism involving NeuroD1.

  4. Intermediate BL Lac objects

    NASA Astrophysics Data System (ADS)

    Bondi, M.; Marchã, M. J. M.; Dallacasa, D.; Stanghellini, C.

    2001-08-01

    The 200-mJy sample, defined by Marchã et al., contains about 60 nearby, northern, flat-spectrum radio sources. In particular, the sample has proved effective at finding nearby radio-selected BL Lac objects with radio luminosities comparable to those of X-ray-selected objects, and low-luminosity flat-spectrum weak emission-line radio galaxies (WLRGs). The 200-mJy sample contains 23 BL Lac objects (including 6 BL Lac candidates) and 19 WLRGs. We will refer to these subsamples as the 200-mJy BL Lac sample and the 200-mJy WLRG sample, respectively. We have started a systematic analysis of the morphological pc-scale properties of the 200-mJy radio sources using VLBI observations. This paper presents VLBI observations at 5 and 1.6GHz of 14 BL Lac objects and WLRGs selected from the 200-mJy sample. The pc-scale morphology of these objects is briefly discussed. We derive the radio beaming parameters of the 200-mJy BL Lac objects and WLRGs and compare them with those of other BL Lac samples and with a sample of FR I radio galaxies. The overall broad-band radio, optical and X-ray properties of the 200-mJy BL Lac sample are discussed and compared with those of other BL Lac samples, radio- and X-ray-selected. We find that the 200-mJy BL Lac objects fill the gap between HBL and LBL objects in the colour-colour plot, and have intermediate αXOX as expected in the spectral energy distribution unification scenario. Finally, we briefly discuss the role of the WLRGs.

  5. Pump-dump-probe and pump-repump-probe ultrafast spectroscopy resolves cross section of an early ground state intermediate and stimulated emission in the photoreactions of the Pr ground state of the cyanobacterial phytochrome Cph1.

    PubMed

    Fitzpatrick, Ann E; Lincoln, Craig N; van Wilderen, Luuk J G W; van Thor, Jasper J

    2012-01-26

    The primary photoreactions of the red absorbing ground state (Pr) of the cyanobacterial phytochrome Cph1 from Synechocystis PCC 6803 involve C15═C16 Z-E photoisomerization of its phycocyanobilin chromophore. The first observable product intermediate in pump-probe measurements of the photocycle, "Lumi-R", is formed with picosecond kinetics and involves excited state decay reactions that have 3 and 14 ps time constants. Here, we have studied the photochemical formation of the Lumi-R intermediate using multipulse picosecond visible spectroscopy. Pump-dump-probe (PDP) and pump-repump-probe (PRP) experiments were carried out by employing two femtosecond visible pulses with 1, 14, and 160 ps delays, together with a broadband dispersive visible probe. The time delays between the two excitation pulses have been selected to allow interaction with the dominant (3 and 14 ps) kinetic phases of Lumi-R formation. The frequency dependence of the PDP and PRP amplitudes was investigated at 620, 640, 660, and 680 nm, covering excited state absorption (λ(max) = 620 nm), ground state absorption (λ(max) = 660 nm), and stimulated emission (λ(max) = 680 nm) cross sections. Experimental double difference transient absorbance signals (ΔΔOD), from the PDP and PRP measurements, required corrections to remove contributions from ground state repumping. The sensitivity of the resulting ΔΔOD signals was systematically investigated for possible connectivity schemes and photochemical parameters. When applying a homogeneous (sequentially decaying) connectivity scheme in both the 3 and 14 ps kinetic phases, evidence for repumping of an intermediate that has an electronic ground state configuration (GSI) is taken from the dump-induced S1 formation with 620, 640, and 660 nm wavelengths and 1 and 14 ps repump delays. Evidence for repumping a GSI is also seen, for the same excitation wavelengths, when imposing a target connectivity scheme proposed in the literature for the 1 ps repump delay. In

  6. Welding. Performance Objectives. Intermediate Course.

    ERIC Educational Resources Information Center

    Vincent, Kenneth

    Several intermediate performance objectives and corresponding criterion measures are listed for each of nine terminal objectives for an intermediate welding course. The materials were developed for a 36-week (3 hours daily) course designed to prepare the student for employment in the field of welding. Electric welding and specialized (TIG & MIG)…

  7. Masonry. Performance Objectives. Intermediate Course.

    ERIC Educational Resources Information Center

    Thompson, Moses

    Several intermediate performance objectives and corresponding criterion measures are listed for each of 13 terminal objectives for an intermediate masonry course. These materials, developed for a two-semester (3 hours daily) course, are designed to provide the student with the skills and knowledge necessary for entry level employment in the field…

  8. Identification, Characterization, and Utilization of Adult Meniscal Progenitor Cells

    DTIC Science & Technology

    2016-09-01

    development of knee osteoarthritis (OA). New treatments centered on the stem/progenitor cell population resident within the adult meniscus will be key to...cells, progenitor cells, meniscus healing, meniscus repair, osteoarthritis 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER...common underlying cause of post- traumatic osteoarthritis . This is particularly striking in young, healthy individuals such as military personnel

  9. Predicting the nature of supernova progenitors

    NASA Astrophysics Data System (ADS)

    Groh, Jose H.

    2017-09-01

    Stars more massive than about 8 solar masses end their lives as a supernova (SN), an event of fundamental importance Universe-wide. The physical properties of massive stars before the SN event are very uncertain, both from theoretical and observational perspectives. In this article, I briefly review recent efforts to predict the nature of stars before death, in particular, by performing coupled stellar evolution and atmosphere modelling of single stars in the pre-SN stage. These models are able to predict the high-resolution spectrum and broadband photometry, which can then be directly compared with the observations of core-collapse SN progenitors. The predictions for the spectral types of massive stars before death can be surprising. Depending on the initial mass and rotation, single star models indicate that massive stars die as red supergiants, yellow hypergiants, luminous blue variables and Wolf-Rayet stars of the WN and WO subtypes. I finish by assessing the detectability of SN Ibc progenitors. This article is part of the themed issue 'Bridging the gap: from massive stars to supernovae'.

  10. The progenitors of supernovae Type Ia

    NASA Astrophysics Data System (ADS)

    Toonen, Silvia

    2014-09-01

    Despite the significance of Type Ia supernovae (SNeIa) in many fields in astrophysics, SNeIa lack a theoretical explanation. SNeIa are generally thought to be thermonuclear explosions of carbon/oxygen (CO) white dwarfs (WDs). The canonical scenarios involve white dwarfs reaching the Chandrasekhar mass, either by accretion from a non-degenerate companion (single-degenerate channel, SD) or by a merger of two CO WDs (double-degenerate channel, DD). The study of SNeIa progenitors is a very active field of research for binary population synthesis (BPS) studies. The strength of the BPS approach is to study the effect of uncertainties in binary evolution on the macroscopic properties of a binary population, in order to constrain binary evolutionary processes. I will discuss the expected SNeIa rate from the BPS approach and the uncertainties in their progenitor evolution, and compare with current observations. I will also discuss the results of the POPCORN project in which four BPS codes were compared to better understand the differences in the predicted SNeIa rate of the SD channel. The goal of this project is to investigate whether differences in the simulated populations are due to numerical effects or whether they can be explained by differences in the input physics. I will show which assumptions in BPS codes affect the results most and hence should be studied in more detail.

  11. Predicting the nature of supernova progenitors.

    PubMed

    Groh, Jose H

    2017-10-28

    Stars more massive than about 8 solar masses end their lives as a supernova (SN), an event of fundamental importance Universe-wide. The physical properties of massive stars before the SN event are very uncertain, both from theoretical and observational perspectives. In this article, I briefly review recent efforts to predict the nature of stars before death, in particular, by performing coupled stellar evolution and atmosphere modelling of single stars in the pre-SN stage. These models are able to predict the high-resolution spectrum and broadband photometry, which can then be directly compared with the observations of core-collapse SN progenitors. The predictions for the spectral types of massive stars before death can be surprising. Depending on the initial mass and rotation, single star models indicate that massive stars die as red supergiants, yellow hypergiants, luminous blue variables and Wolf-Rayet stars of the WN and WO subtypes. I finish by assessing the detectability of SN Ibc progenitors.This article is part of the themed issue 'Bridging the gap: from massive stars to supernovae'. © 2017 The Author(s).

  12. Neutrino emission from nearby supernova progenitors

    NASA Astrophysics Data System (ADS)

    Yoshida, Takashi; Takahashi, Koh; Umeda, Hideyuki

    2016-05-01

    Neutrinos have an important role for energy loss process during advanced evolution of massive stars. Although the luminosity and average energy of neutrinos during the Si burning are much smaller than those of supernova neutrinos, these neutrinos are expected to be detected by the liquid scintillation neutrino detector KamLAND if a supernova explosion occurs at the distance of ~100 parsec. We investigate the neutrino emission from massive stars during advanced evolution. We calculate the evolution of the energy spectra of neutrinos produced through electron-positron pair-annihilation in the supernova progenitors with the initial mass of 12, 15, and 20 M ⊙ during the Si burning and core-collapse stages. The neutrino emission rate increases from ~ 1050 s-1 to ~ 1052 s-1. The average energy of electron-antineutrinos is about 1.25 MeV during the Si burning and gradually increases until the core-collapse. For one week before the supernova explosion, the KamLAND detector is expected to observe 12-24 and 6-13 v¯e events in the normal and inverted mass hierarchies, respectively, if a supernova explosion of a 12-20 M ⊙ star occurs at the distance of 200 parsec, corresponding to the distance to Betelgeuse. Observations of neutrinos from SN progenitors have a possibility to constrain the core structure and the evolution just before the core collapse of massive stars.

  13. Identification and isolation of adult liver stem/progenitor cells.

    PubMed

    Tanaka, Minoru; Miyajima, Atsushi

    2012-01-01

    Hepatoblasts are considered to be liver stem/progenitor cells in the fetus because they propagate and differentiate into two types of liver epithelial cells, hepatocytes and cholangiocytes. In adults, oval cells that emerge in severely injured liver are considered facultative hepatic stem/progenitor cells. However, the nature of oval cells has remained unclear for long time due to the lack of a method to isolate them. It has also been unclear whether liver stem/progenitor cells exist in normal adult liver. Recently, we and others have successfully identified oval cells and adult liver stem/progenitor cells. Here, we describe the identification and isolation of mouse liver stem/progenitor cells by utilizing antibodies against specific cell surface marker molecules.

  14. Lgr5(+ve) stem/progenitor cells contribute to nephron formation during kidney development.

    PubMed

    Barker, Nick; Rookmaaker, Maarten B; Kujala, Pekka; Ng, Annie; Leushacke, Marc; Snippert, Hugo; van de Wetering, Marc; Tan, Shawna; Van Es, Johan H; Huch, Meritxell; Poulsom, Richard; Verhaar, Marianne C; Peters, Peter J; Clevers, Hans

    2012-09-27

    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. Copyright © 2012 The Authors. Published by Elsevier Inc. All rights reserved.

  15. Postembryonic Nephrogenesis and Persistence of Six2-Expressing Nephron Progenitor Cells in the Reptilian Kidney.

    PubMed

    Camarata, Troy; Howard, Alexis; Elsey, Ruth M; Raza, Sarah; O'Connor, Alice; Beatty, Brian; Conrad, Jack; Solounias, Nikos; Chow, Priscilla; Mukta, Saima; Vasilyev, Aleksandr

    2016-01-01

    New nephron formation (nephrogenesis) ceases in mammals around birth and is completely absent in adults. In contrast, postembryonic nephrogenesis is well documented in the mesonephric kidneys of fishes and amphibians. The transient mesonephros in reptiles (including birds) and mammals is replaced by the metanephros during embryogenesis. Thus, one may speculate that postembryonic nephrogenesis is restricted to the mesonephric kidney. Previous reports have suggested the metanephros of non-avian reptiles (hereafter reptiles) may continually form nephrons throughout life. We investigated the presence of adult nephrogenesis in reptiles by examining adult kidneys from several species including Trachemys scripta, Chrysemys picta, Boa constrictor, Tupinambis tegu, Anolis carolinensis, and Alligator mississipiensis among others. We found that all major reptilian groups (Testudines, Crocodylia, and Squamates) showed the presence of adult nephrogenesis. The total amount of nephrogenesis varied greatly between species with turtles displaying the highest density of nephrogenesis. In contrast, we were unable to detect adult nephrogenesis in monotremes, and in the iguanid A. carolinensis. Nephron progenitor cells express the transcription factor Six2, which in mammals, becomes downregulated as the progenitor cell population is exhausted and nephrogenesis ends. Using the alligator as a model, we were able to detect Six2-positive cap mesenchyme cells in the adult kidney, which spatially correlated with areas of nephrogenesis. These results suggest that the metanephric kidney of reptiles has maintained the ability to continually grow new nephrons during postembryonic life, a process lost early in mammalian evolution, likely due to the persistence of a Six2-expressing progenitor cell population.

  16. Molecular and Functional Characterization of Lymphoid Progenitor Subsets Reveals a Bipartite Architecture of Human Lymphopoiesis.

    PubMed

    Alhaj Hussen, Kutaiba; Vu Manh, Thien-Phong; Guimiot, Fabien; Nelson, Elisabeth; Chabaane, Emna; Delord, Marc; Barbier, Maxime; Berthault, Claire; Dulphy, Nicolas; Alberdi, Antonio José; Burlen-Defranoux, Odile; Socié, Gerard; Bories, Jean Christophe; Larghero, Jerôme; Vanneaux, Valérie; Verhoeyen, Els; Wirth, Thierry; Dalod, Marc; Gluckman, Jean Claude; Cumano, Ana; Canque, Bruno

    2017-10-17

    The classical model of hematopoiesis established in the mouse postulates that lymphoid cells originate from a founder population of common lymphoid progenitors. Here, using a modeling approach in humanized mice, we showed that human lymphoid development stemmed from distinct populations of CD127 - and CD127 + early lymphoid progenitors (ELPs). Combining molecular analyses with in vitro and in vivo functional assays, we demonstrated that CD127 - and CD127 + ELPs emerged independently from lympho-mono-dendritic progenitors, responded differently to Notch1 signals, underwent divergent modes of lineage restriction, and displayed both common and specific differentiation potentials. Whereas CD127 - ELPs comprised precursors of T cells, marginal zone B cells, and natural killer (NK) and innate lymphoid cells (ILCs), CD127 + ELPs supported production of all NK cell, ILC, and B cell populations but lacked T potential. On the basis of these results, we propose a "two-family" model of human lymphoid development that differs from the prevailing model of hematopoiesis. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    PubMed

    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.

  18. Pdx-1 and Ptf1a concurrently determine fate specification of pancreatic multipotent progenitor cells

    PubMed Central

    Burlison, Jared S.; Long, Qiaoming; Fujitani, Yoshio; Wright, Christopher V.E.; Magnuson, Mark A.

    2008-01-01

    The pancreas is derived from a pool of multipotent progenitor cells (MPCs) that co-express Pdx-1 and Ptf1a. To more precisely define how the individual and combined loss of Pdx-1 and Ptf1a affects pancreatic MPC specification and differentiation we derived and studied mice bearing a novel Ptf1aYFP allele. While the expression of Pdx-1 and Ptf1a in pancreatic MPCs coincides between E9.5–12.5 the developmental phenotypes of Pdx-1 null and Pdx-1; Ptf1a double null mice are indistinguishable, and an early pancreatic bud is formed in both cases. This finding indicates that Pdx-1 is required in the foregut endoderm prior to Ptf1a for pancreatic MPC specification. We also found that Ptf1a is neither required for specification of Ngn3-positive endocrine progenitors nor differentiation of mature β-cells. In the absence of Pdx-1 Ngn3-positive cells were not observed after E9.5. Thus, in contrast to the deletion of Ptf1a, the loss of Pdx-1 precludes the sustained Ngn3-based derivation of endocrine progenitors from pancreatic MPCs. Taken together, these studies indicate that Pdx-1 and Ptf1a have distinct but interdependent functions during pancreatic MPC specification. PMID:18294628

  19. Pdx-1 and Ptf1a concurrently determine fate specification of pancreatic multipotent progenitor cells.

    PubMed

    Burlison, Jared S; Long, Qiaoming; Fujitani, Yoshio; Wright, Christopher V E; Magnuson, Mark A

    2008-04-01

    The pancreas is derived from a pool of multipotent progenitor cells (MPCs) that co-express Pdx-1 and Ptf1a. To more precisely define how the individual and combined loss of Pdx-1 and Ptf1a affects pancreatic MPC specification and differentiation we derived and studied mice bearing a novel Ptf1a(YFP) allele. While the expression of Pdx-1 and Ptf1a in pancreatic MPCs coincides between E9.5 and 12.5 the developmental phenotypes of Pdx-1 null and Pdx-1; Ptf1a double null mice are indistinguishable, and an early pancreatic bud is formed in both cases. This finding indicates that Pdx-1 is required in the foregut endoderm prior to Ptf1a for pancreatic MPC specification. We also found that Ptf1a is neither required for specification of Ngn3-positive endocrine progenitors nor differentiation of mature beta-cells. In the absence of Pdx-1 Ngn3-positive cells were not observed after E9.5. Thus, in contrast to the deletion of Ptf1a, the loss of Pdx-1 precludes the sustained Ngn3-based derivation of endocrine progenitors from pancreatic MPCs. Taken together, these studies indicate that Pdx-1 and Ptf1a have distinct but interdependent functions during pancreatic MPC specification.

  20. The history of the dark and luminous side of Milky Way-like progenitors

    NASA Astrophysics Data System (ADS)

    Graziani, L.; de Bennassuti, M.; Schneider, R.; Kawata, D.; Salvadori, S.

    2017-07-01

    Here we investigate the evolution of a Milky Way (MW)-like galaxy with the aim of predicting the properties of its progenitors all the way from z ∼ 20 to z = 0. We apply gamesh to a high-resolution N-body simulation following the formation of a MW-type halo and we investigate its properties at z ∼ 0 and its progenitors in 0 < z < 4. Our model predicts the observed galaxy main sequence, the mass-metallicity and the Fundamental Plane of metallicity relations in 0 < z < 4. It also reproduces the stellar mass evolution of candidate MW progenitors in 0 ≲ z ≲ 2.5, although the star formation rate and gas fraction of the simulated galaxies follow a shallower redshift dependence. We find that while the MW star formation and chemical enrichment are dominated by the contribution of galaxies hosted in Lyman α cooling haloes, at z > 6 the contribution of star-forming minihaloes is comparable to the star formation rate along the MW merger tree. These systems might then provide an important contribution in the early phases of reionization. A large number of minihaloes with old stellar populations, possibly Population III stars, are dragged into the MW or survive in the Local Group. At low redshift dynamical effects, such as halo mergers, tidal stripping and halo disruption redistribute the baryonic properties among halo families. These results are critically discussed in light of future improvements including a more sophisticated treatment of radiative feedback and inhomogeneous metal enrichment.

  1. Characteristics of hepatic stem/progenitor cells in the fetal and adult liver.

    PubMed

    Koike, Hiroyuki; Taniguchi, Hideki

    2012-11-01

    The liver is an essential organ that maintains vital activity through its numerous important functions. It has a unique capability of fully regenerating after injury. Regulating a balance between self-renewal and differentiation of hepatic stem cells that are resources for functional mature liver cells is required for maintenance of tissue homeostasis. This review describes the characteristics of hepatic stem/progenitor cells and the regulatory mechanism of their self-renewal and differentiation capacity. In liver organogenesis, undifferentiated hepatic stem/progenitor cells expand their pool by repeated self-renewal in the early stage of liver development and then differentiate into two different types of cell lineage, namely hepatocytes and cholangiocytes. Liver development is regulated by expression of stem cell transcription factors in a complex multistep process. Recent studies suggest that stem cells are maintained by integrative regulation of gene expression patterns related to self-renewal and differentiation by epigenetic mechanisms such as histone modification and DNA methylation. Analysis of the proper regulatory mechanism of hepatic stem/progenitor cells is important for regenerative medicine that utilizes hepatic stem cells and for preventing liver cancer through clarification of the carcinogenetic mechanism involved in stem cell system failure.

  2. An insulin signaling feedback loop regulates pancreas progenitor cell differentiation during islet development and regeneration

    PubMed Central

    Ye, Lihua; Robertson, Morgan A.; Mastracci, Teresa L.; Anderson, Ryan M.

    2016-01-01

    As one of the key nutrient sensors, insulin signaling plays an important role in integrating environmental energy cues with organism growth. In adult organisms, relative insufficiency of insulin signaling induces compensatory expansion of insulin-secreting pancreatic beta (β) cells. However, little is known about how insulin signaling feedback might influence neogenesis of β cells during embryonic development. Using genetic approaches and a unique cell transplantation system in developing zebrafish, we have uncovered a novel role for insulin signaling in the negative regulation of pancreatic progenitor cell differentiation. Blocking insulin signaling in the pancreatic progenitors hastened the expression of the essential β cell genes insulin and pdx1, and promoted β cell fate at the expense of alpha cell fate. In addition, loss of insulin signaling promoted β cell regeneration and destabilization of alpha cell character. These data indicate that insulin signaling constitutes a tunable mechanism for β cell compensatory plasticity during early development. Moreover, using a novel blastomere-to-larva transplantation strategy, we found that loss of insulin signaling in endoderm-committed blastomeres drove their differentiation into β cells. Furthermore, the extent of this differentiation was dependent on the function of the β cell mass in the host. Altogether, our results indicate that modulation of insulin signaling will be crucial for the development of β cell restoration therapies for diabetics; further clarification of the mechanisms of insulin signaling in β cell progenitors will reveal therapeutic targets for both in vivo and in vitro β cell generation. PMID:26658317

  3. Postembryonic Nephrogenesis and Persistence of Six2-Expressing Nephron Progenitor Cells in the Reptilian Kidney

    PubMed Central

    Camarata, Troy; Howard, Alexis; Elsey, Ruth M.; Raza, Sarah; O’Connor, Alice; Beatty, Brian; Conrad, Jack; Solounias, Nikos; Chow, Priscilla; Mukta, Saima; Vasilyev, Aleksandr

    2016-01-01

    New nephron formation (nephrogenesis) ceases in mammals around birth and is completely absent in adults. In contrast, postembryonic nephrogenesis is well documented in the mesonephric kidneys of fishes and amphibians. The transient mesonephros in reptiles (including birds) and mammals is replaced by the metanephros during embryogenesis. Thus, one may speculate that postembryonic nephrogenesis is restricted to the mesonephric kidney. Previous reports have suggested the metanephros of non-avian reptiles (hereafter reptiles) may continually form nephrons throughout life. We investigated the presence of adult nephrogenesis in reptiles by examining adult kidneys from several species including Trachemys scripta, Chrysemys picta, Boa constrictor, Tupinambis tegu, Anolis carolinensis, and Alligator mississipiensis among others. We found that all major reptilian groups (Testudines, Crocodylia, and Squamates) showed the presence of adult nephrogenesis. The total amount of nephrogenesis varied greatly between species with turtles displaying the highest density of nephrogenesis. In contrast, we were unable to detect adult nephrogenesis in monotremes, and in the iguanid A. carolinensis. Nephron progenitor cells express the transcription factor Six2, which in mammals, becomes downregulated as the progenitor cell population is exhausted and nephrogenesis ends. Using the alligator as a model, we were able to detect Six2-positive cap mesenchyme cells in the adult kidney, which spatially correlated with areas of nephrogenesis. These results suggest that the metanephric kidney of reptiles has maintained the ability to continually grow new nephrons during postembryonic life, a process lost early in mammalian evolution, likely due to the persistence of a Six2-expressing progenitor cell population. PMID:27144443

  4. Pleiotrophin enhances PDGFB-induced gliomagenesis through increased proliferation of neural progenitor cells

    PubMed Central

    Zhang, Lei; Laaniste, Liisi; Jiang, Yiwen; Alafuzoff, Irina; Uhrbom, Lene; Dimberg, Anna

    2016-01-01

    Pleiotrophin (PTN) augments tumor growth by increasing proliferation of tumor cells and promoting vascular abnormalization, but its role in early gliomagenesis has not been evaluated. Through analysis of publically available datasets, we demonstrate that increased PTN mRNA expression is associated with amplification of chromosome 7, identified as one of the earliest steps in glioblastoma development. To elucidate the role of PTN in tumor initiation we employed the RCAS/tv-a model that allows glioma induction by RCAS-virus mediated expression of oncogenes in neural progenitor cells. Intracranial injection of RCAS-PTN did not induce glioma formation when administrated alone, but significantly enhanced RCAS-platelet derived growth factor (PDGF)B-induced gliomagenesis. PTN co-treatment augmented PDGFB-induced Akt activation in neural progenitor cells in vitro, and enhanced neural sphere size associated with increased proliferation. Our data indicates that PTN expression is associated with chromosome 7 gain, and that PTN enhances PDGFB-induced gliomagenesis by stimulating proliferation of neural progenitor cells. PMID:27806344

  5. Pleiotrophin enhances PDGFB-induced gliomagenesis through increased proliferation of neural progenitor cells.

    PubMed

    Zhang, Lei; Laaniste, Liisi; Jiang, Yiwen; Alafuzoff, Irina; Uhrbom, Lene; Dimberg, Anna

    2016-12-06

    Pleiotrophin (PTN) augments tumor growth by increasing proliferation of tumor cells and promoting vascular abnormalization, but its role in early gliomagenesis has not been evaluated. Through analysis of publically available datasets, we demonstrate that increased PTN mRNA expression is associated with amplification of chromosome 7, identified as one of the earliest steps in glioblastoma development. To elucidate the role of PTN in tumor initiation we employed the RCAS/tv-a model that allows glioma induction by RCAS-virus mediated expression of oncogenes in neural progenitor cells. Intracranial injection of RCAS-PTN did not induce glioma formation when administrated alone, but significantly enhanced RCAS-platelet derived growth factor (PDGF)B-induced gliomagenesis. PTN co-treatment augmented PDGFB-induced Akt activation in neural progenitor cells in vitro, and enhanced neural sphere size associated with increased proliferation. Our data indicates that PTN expression is associated with chromosome 7 gain, and that PTN enhances PDGFB-induced gliomagenesis by stimulating proliferation of neural progenitor cells.

  6. MYCN Promotes the Expansion of Phox2B-Positive Neuronal Progenitors to Drive Neuroblastoma Development

    PubMed Central

    Alam, Goleeta; Cui, Hongjuan; Shi, Huilin; Yang, Liqun; Ding, Jane; Mao, Ling; Maltese, William A.; Ding, Han-Fei

    2009-01-01

    Amplification of the oncogene MYCN is a tumorigenic event in the development of a subset of neuroblastomas that commonly consist of undifferentiated or poorly differentiated neuroblasts with unfavorable clinical outcome. The cellular origin of these neuroblasts is unknown. Additionally, the cellular functions and target cells of MYCN in neuroblastoma development remain undefined. Here we examine the cell types that drive neuroblastoma development in TH-MYCN transgenic mice, an animal model of the human disease. Neuroblastoma development in these mice begins with hyperplastic lesions in early postnatal sympathetic ganglia. We show that both hyperplasia and primary tumors are composed predominantly of highly proliferative Phox2B+ neuronal progenitors. MYCN induces the expansion of these progenitors by both promoting their proliferation and preventing their differentiation. We further identify a minor population of undifferentiated nestin+ cells in both hyperplastic lesions and primary tumors that may serve as precursors of Phox2B+ neuronal progenitors. These findings establish the identity of neuroblasts that characterize the tumor phenotype and suggest a cellular pathway by which MYCN can promote neuroblastoma development. PMID:19608868

  7. Cotransplantation of ex vivo expanded progenitors with nonexpanded cord blood cells improves platelet recovery.

    PubMed

    Émond, Hélène; Boyer, Lucie; Roy, Denis-Claude; Pineault, Nicolas

    2012-11-20

    Umbilical cord blood (UCB) transplantation is associated with prolonged periods of cytopenia. Ex vivo expansion of hematopoietic stem and progenitor cells (HSPCs) is currently investigated as a mean to accelerate hematological recovery. Contrary to neutrophils, platelet recovery remains problematic. For this reason, we have developed a culture protocol promoting the expansion of megakaryocyte (Mk) progenitors. The objective of this work was to determine whether the expanded (E) UCB HSPCs could accelerate platelet recovery in vivo using a murine HSPC transplantation model. The thrombopoietic activity of UCB and mobilized peripheral blood CD34(+) cells expanded under mild hyperthermia (MH, ie, 39°C) with the optimized megakaryocyte progenitor cocktail (OMPC) diverged significantly from the nonexpanded (NE) cells of origin; E cells provided rapid platelet release, while NE cells strongly contributed to platelet production past 10 days of transplantation. Consequently, the complementary of both cell sources was investigated. Cotransplantation of NE with E UCB cells significantly improved the recovery of human platelets (hPLTs) in vivo due to their complementary and synergistic thrombopoietic activities. Moreover, short-term human bone marrow (BM) reconstitution was also improved. Finally, we show that early hPLT release is dependent on Mk-primed cells and that E cells do not act as accessory cells, but have a more active role. In conclusion, hPLT recovery and short-term BM engraftment can be efficiently improved by the cotransplantation of Mk-primed UCB cells with NE HSPCs in a murine transplantation model.

  8. Recent progress on normal and malignant pancreatic stem/progenitor cell research: therapeutic implications for the treatment of type 1 or 2 diabetes mellitus and aggressive pancreatic cancer

    PubMed Central

    Mimeault, M; Batra, S K

    2010-01-01

    Recent progress on pancreatic stem/progenitor cell research has revealed that the putative multipotent pancreatic stem/progenitor cells and/or more committed beta cell precursors may persist in the pancreatic gland in adult life. The presence of immature pancreatic cells with stem cell-like properties offers the possibility of stimulating their in vivo expansion and differentiation or to use their ex vivo expanded progenies for beta cell replacement-based therapies for type 1 or 2 diabetes mellitus in humans. In addition, the transplantation of either insulin-producing beta cells derived from embryonic, fetal and other tissue-resident adult stem/progenitor cells or genetically modified adult stem/progenitor cells may also constitute alternative promising therapies for treating diabetic patients. The genetic and/or epigenetic alterations in putative pancreatic adult stem/progenitor cells and/or their early progenies may, however, contribute to their acquisition of a dysfunctional behaviour as well as their malignant transformation into pancreatic cancer stem/progenitor cells. More particularly, the activation of distinct tumorigenic signalling cascades, including the hedgehog, epidermal growth factor–epidermal growth factor receptor (EGF–EGFR) system, wingless ligand (Wnt)/β-catenin and/or stromal cell-derived factor-1 (SDF-1)–CXC chemokine receptor 4 (CXCR4) pathways may play a major role in the sustained growth, survival, metastasis and/or drug resistance of pancreatic cancer stem/progenitor cells and their further differentiated progenies. The combination of drugs that target the oncogenic elements in pancreatic cancer stem/progenitor cells and their microenvironment, with the conventional chemotherapeutic regimens, could represent promising therapeutic strategies. These novel targeted therapies should lead to the development of more effective treatments of locally advanced and metastatic pancreatic cancers, which remain incurable with current therapies

  9. iPTF15dtg: a double-peaked Type Ic supernova from a massive progenitor

    DOE PAGES

    Taddia, Francesco; Fremling, C.; Sollerman, J.; ...

    2016-08-04

    Type Ic supernovae (SNe Ic) arise from the core-collapse of H- (and He-) poor stars, which could either be single Wolf-Rayet (WR) stars or lower-mass stars stripped of their envelope by a companion. Their light curves are radioactively powered and usually show a fast rise to peak (~10-15 d), without any early (in the first few days) emission bumps (with the exception of broad-lined SNe Ic) as sometimes seen for other types of stripped-envelope SNe (e.g., Type IIb SN 1993J and Type Ib SN 2008D). Here, we have studied iPTF15dtg, a spectroscopically normal SN Ic with an early excess inmore » the optical light curves followed by a long (~30 d) rise to the main peak. It is the first spectroscopically-normal double-peaked SN Ic to be observed. Our aim is to determine the properties of this explosion and of its progenitor star. Methods. Optical photometry and spectroscopy of iPTF15dtg was obtained with multiple telescopes. The resulting light curves and spectral sequence are analyzed and modeled with hydrodynamical and analytical models, with particular focus on the early emission. iPTF15dtg is a slow rising SN Ic, similar to SN 2011bm. Hydrodynamical modeling of the bolometric properties reveals a large ejecta mass (~10 M ⊙) and strong 56Ni mixing. The luminous early emission can be reproduced if we account for the presence of an extended (≳500 R ⊙), low-mass (≳0.045 M ⊙) envelope around the progenitor star. Alternative scenarios for the early peak, such as the interaction with a companion, a shock-breakout (SBO) cooling tail from the progenitor surface, or a magnetar-driven SBO are not favored. In conclusion, the large ejecta mass and the presence of H- and He-free extended material around the star suggest that the progenitor of iPTF15dtg was a massive (≳35 M ⊙) WR star that experienced strong mass loss.« less

  10. CD44-mediated hyaluronan binding marks proliferating hematopoietic progenitor cells and promotes bone marrow engraftment

    PubMed Central

    Lee-Sayer, Sally S. M.; Dougan, Meghan N.; Cooper, Jesse; Sanderson, Leslie; Dosanjh, Manisha; Maxwell, Christopher A.

    2018-01-01

    CD44 is a widely expressed cell adhesion molecule that binds to the extracellular matrix component, hyaluronan. However, this interaction is not constitutive in most immune cells at steady state, as the ability of CD44 to engage hyaluronan is highly regulated. While activated T cells and macrophages gain the ability to bind hyaluronan by CD44, the status in other immune cells is less studied. Here we found a percentage of murine eosinophils, natural killer and natural killer T cells were capable of interacting with hyaluronan at steady state. To further investigate the consequences of hyaluronan binding by CD44 in the hematopoietic system, point mutations of CD44 that either cannot bind hyaluronan (LOF-CD44) or have an increased affinity for hyaluronan (GOF-CD44) were expressed in CD44-deficient bone marrow. Competitive bone marrow reconstitution of irradiated mice revealed an early preference for GOF-CD44 over WT-CD44 expressing cells, and for WT-CD44 over LOF-CD44 expressing cells, in the hematopoietic progenitor cell compartment. The advantage of the hyaluronan-binding cells was observed in the hematopoietic stem and progenitor populations, and was maintained throughout the immune system. Hematopoietic stem cells bound minimal hyaluronan at steady state, and this was increased when the cells were induced to proliferate whereas multipotent progenitors had an increased ability to bind hyaluronan at steady state. In vitro, the addition of hyaluronan promoted their proliferation. Thus, proliferating hematopoietic progenitors bind hyaluronan, and hyaluronan binding cells have a striking competitive advantage in bone marrow engraftment. PMID:29684048

  11. Light Echoes and the Progenitor of SN 2016adj in Cen A

    NASA Astrophysics Data System (ADS)

    Sugerman, Ben

    2015-10-01

    Supernova (SN) 2016adj is the fifth closest SN to be discovered during the lifetime of HST. This event offers us a rich variety of rare and unique opportunities, including: (1) identifying the progenitor; (2) mapping the three-dimensional structure and chemical composition of the progenitor's circumstellar and the host galaxy's interstellar environments; (3) testing models of stellar mass loss and high-mass stellar evolution; and (4) measuring the distance to the host galaxy, Cen A. The progenitor field of the SN has been observed from the near-UV to the near-IR with WFC3, which will immediately allow us to accomplish the first science goal by identifying the progenitor (or establishing its upper limits) once a new image with the SN present is taken. Preliminary analyses of early-time spectra of SN 2016adj indicate its light is being extinguished by at least A(V)=2-4 magnitudes, meaning it is buried deep within the dust lane of Cen A. Echoes of the SN light off of this dust will allow us to produce high-resolution, three-dimensional maps of the structure and composition of the dust in and around the line-of-sight to the SN, which we will use (as explained in this proposal) to accomplish science goals (2)-(4) listed above. Please note that since echoes pass through a given point in space only once, data are permanently lost for each epoch that is not observed. While we will propose for continued observations in the Cycle 24 call for proposals, most of the science we propose cannot be achieved if the observations in this proposal are not taken before Cycle 24 begins.

  12. Light Echoes and the Progenitor of SN 2016adj in Cen A

    NASA Astrophysics Data System (ADS)

    Sugerman, Ben; Lawrence, Stephen

    2016-02-01

    The Type Ib/IIb supernova (SN) 2016adj is the fifth closest SN to be discovered during the lifetime of HST. This event offers us a rich variety of rare and unique opportunities, including: (1) identifying the progenitor; (2) mapping the three-dimensional structure and chemical composition of the progenitor's circumstellar and the host galaxy's interstellar environments; and (3) testing models of stellar mass loss and high-mass stellar evolution. The progenitor field of the SN has been observed from the near-UV to the mid-IR with HST and Spitzer, which will immediately allow us to accomplish the first science goal by identifying the progenitor (or establishing its upper limits) once new image with the SN present are taken with both observatories. Preliminary analyses of early-time spectra of SN 2016adj indicate its light is being extinguished by at least A(V)=2-4 magnitudes, meaning it is buried deep within the dust lane of Cen A. Echoes of the SN light off of this dust will allow us to produce high-resolution, three-dimensional maps of the structure and composition of the dust in and around the line-of-sight to the SN, which we will use to accomplish science goals (2)-(3) listed above. In particular, we will directly test the hypothesis that Type Ib/IIb SNe come not from very-high mass stars but from only moderately-massive stars that lost their envelopes to close binary companions. Please note that since echoes pass through a given point in space only once, data are permanently lost for each epoch that is not observed. While we will propose for continued observations in the Cycle 13 call for proposals, most of the science we propose cannot be achieved if the observations in this proposal are not taken before Cycle 13 begins.

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

    SciTech Connect

    Fung, Elizabeth-sharon

    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, expressionmore » 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.« less

  14. Sox2+ progenitors in sharks link taste development with the evolution of regenerative teeth from denticles

    PubMed Central

    Martin, Kyle J.; Rasch, Liam J.; Cooper, Rory L.; Johanson, Zerina; Fraser, Gareth J.

    2016-01-01

    Teeth and denticles belong to a specialized class of mineralizing epithelial appendages called odontodes. Although homology of oral teeth in jawed vertebrates is well supported, the evolutionary origin of teeth and their relationship with other odontode types is less clear. We compared the cellular and molecular mechanisms directing development of teeth and skin denticles in sharks, where both odontode types are retained. We show that teeth and denticles are deeply homologous developmental modules with equivalent underlying odontode gene regulatory networks (GRNs). Notably, the expression of the epithelial progenitor and stem cell marker sex-determining region Y-related box 2 (sox2) was tooth-specific and this correlates with notable differences in odontode regenerative ability. Whereas shark teeth retain the ancestral gnathostome character of continuous successional regeneration, new denticles arise only asynchronously with growth or after wounding. Sox2+ putative stem cells associated with the shark dental lamina (DL) emerge from a field of epithelial progenitors shared with anteriormost taste buds, before establishing within slow-cycling cell niches at the (i) superficial taste/tooth junction (T/TJ), and (ii) deep successional lamina (SL) where tooth regeneration initiates. Furthermore, during regeneration, cells from the superficial T/TJ migrate into the SL and contribute to new teeth, demonstrating persistent contribution of taste-associated progenitors to tooth regeneration in vivo. This data suggests a trajectory for tooth evolution involving cooption of the odontode GRN from nonregenerating denticles by sox2+ progenitors native to the oral taste epithelium, facilitating the evolution of a novel regenerative module of odontodes in the mouth of early jawed vertebrates: the teeth. PMID:27930309

  15. Requirement for Foxd3 in Maintenance of Neural Crest Progenitors

    PubMed Central

    Teng, Lu; Mundell, Nathan A.; Frist, Audrey Y.; Wang, Qiaohong; Labosky, Patricia A.

    2008-01-01

    Summary Understanding the molecular mechanisms of stem cell maintenance is critical for the ultimate goal of manipulating stem cells for treatment of disease. Foxd3 is required early in mouse embryogenesis; Foxd3−/− embryos fail around the time of implantation, cells of the inner cell mass cannot be maintained in vitro, and blastocyst-derived stem cell lines cannot be established. Here, we report that Foxd3 is required for maintenance of the multipotent mammalian neural crest. Using tissue specific deletion of Foxd3 in the neural crest, we show that Foxd3flox/−; Wnt1-Cre mice die perinatally with a catastrophic loss of neural crest-derived structures. Cranial neural crest tissues are either missing or severely reduced in size, the peripheral nervous system consists of reduced dorsal root ganglia and cranial nerves, and the entire gastrointestinal tract is devoid of neural crest derivatives. These results demonstrate a global role for this transcriptional repressor in all aspects of neural crest maintenance along the anterior-posterior axis, and establish an unprecedented molecular link between multiple divergent progenitor lineages of the mammalian embryo. PMID:18367558

  16. Characterization of human pancreatic progenitor cells.

    PubMed

    Noguchi, Hirofumi; Naziruddin, Bashoo; Jackson, Andrew; Shimoda, Masayuki; Ikemoto, Tetsuya; Fujita, Yasutaka; Chujo, Daisuke; Takita, Morihito; Kobayashi, Naoya; Onaca, Nicholas; Hayashi, Shuji; Levy, Marlon F; Matsumoto, Shinichi

    2010-01-01

    β-Cell replacement therapy via islet transplantation is an effective treatment for diabetes mellitus, but its widespread use is severely limited by the shortage of donor organs. Because pancreatic stem/progenitor cells are abundantly available in the pancreas of these patients and in donor organs, the cells could become a useful target for β-cell replacement therapy. We previously established a mouse pancreatic stem cell line without genetic manipulation. In this study, we used the techniques to identify and isolate human pancreatic stem/progenitor cells. The cells from a duct-rich population were cultured in 23 kinds of culture media, based on media for mouse pancreatic stem cells or for human embryonic stem cells. The cells in serum-free media formed "cobblestone" morphologies, similar to a mouse pancreatic stem cell line. On the other hand, the cells in serum-containing medium and the medium for human embryonic stem cells formed "fibroblast-like" morphologies. The cells divided actively until day 30, and the population doubling level (PDL) was 6-10. However, the cells stopped dividing after 30 days in any culture conditions. During the cultures, the nucleus/cytoplasm (N/C) ratio decreased, suggesting that the cells entered senescence. Exendin-4 treatment and transduction of PDX-1 and NeuroD proteins by protein transduction technology into the cells induced insulin and pancreas-related gene expression. Although the duplications of these cells were limited, this approach could provide a potential new source of insulin-producing cells for transplantation.

  17. Thyroid hormone accelerates the differentiation of adult hippocampal progenitors.

    PubMed

    Kapoor, R; Desouza, L A; Nanavaty, I N; Kernie, S G; Vaidya, V A

    2012-09-01

    Disrupted thyroid hormone function evokes severe physiological consequences in the immature brain. In adulthood, although clinical reports document an effect of thyroid hormone status on mood and cognition, the molecular and cellular changes underlying these behavioural effects are poorly understood. More recently, the subtle effects of thyroid hormone on structural plasticity in the mature brain, in particular on adult hippocampal neurogenesis, have come to be appreciated. However, the specific stages of adult hippocampal progenitor development that are sensitive to thyroid hormone are not defined. Using nestin-green fluorescent protein reporter mice, we demonstrate that thyroid hormone mediates its effects on hippocampal neurogenesis by influencing Type 2b and Type 3 progenitors, although it does not alter proliferation of either the Type 1 quiescent progenitor or the Type 2a amplifying neural progenitor. Thyroid hormone increases the number of doublecortin (DCX)-positive Type 3 progenitors, and accelerates neuronal differentiation into both DCX-positive immature neurones and neuronal nuclei-positive granule cell neurones. Furthermore, we show that this increase in neuronal differentiation is accompanied by a significant induction of specific transcription factors involved in hippocampal progenitor differentiation. In vitro studies using the neurosphere assay support a direct effect of thyroid hormone on progenitor development because neurospheres treated with thyroid hormone are shifted to a more differentiated state. Taken together, our results indicate that thyroid hormone mediates its neurogenic effects via targeting Type 2b and Type 3 hippocampal progenitors, and suggests a role for proneural transcription factors in contributing to the effects of thyroid hormone on neuronal differentiation of adult hippocampal progenitors. © 2012 The Authors. Journal of Neuroendocrinology © 2012 British Society for Neuroendocrinology.

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

    SciTech Connect

    Chen, Ying, E-mail: ying.chen@hc.msu.edu; Wang, Kai; Gong, Yun Guo

    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, canmore » 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

  19. Exposure to ultrafine particles, intracellular production of reactive oxygen species in leukocytes and altered levels of endothelial progenitor cells.

    PubMed

    Jantzen, Kim; Møller, Peter; Karottki, Dorina Gabriela; Olsen, Yulia; Bekö, Gabriel; Clausen, Geo; Hersoug, Lars-Georg; Loft, Steffen

    2016-06-01

    Exposure to particles in the fine and ultrafine size range has been linked to induction of low-grade systemic inflammation, oxidative stress and development of cardiovascular diseases. Declining levels of endothelial progenitor cells within systemic circulation have likewise been linked to progression of cardiovascular diseases. The objective was to determine if exposure to fine and ultrafine particles from indoor and outdoor sources, assessed by personal and residential indoor monitoring, is associated with altered levels of endothelial progenitor cells, and whether such effects are related to leukocyte-mediated oxidative stress. The study utilized a cross sectional design performed in 58 study participants from a larger cohort. Levels of circulating endothelial progenitor cells, defined as either late (CD34(+)KDR(+) cells) or early (CD34(+)CD133(+)KDR(+) cells) subsets were measured using polychromatic flow cytometry. We additionally measured production of reactive oxygen species in leukocyte subsets (lymphocytes, monocytes and granulocytes) by flow cytometry using intracellular 2',7'-dichlorofluoroscein. The measurements encompassed both basal levels of reactive oxygen species production and capacity for reactive oxygen species production for each leukocyte subset. We found that the late endothelial progenitor subset was negatively associated with levels of ultrafine particles measured within the participant residences and with reactive oxygen species production capacity in lymphocytes. Additionally, the early endothelial progenitor cell levels were positively associated with a personalised measure of ultrafine particle exposure and negatively associated with both basal and capacity for reactive oxygen species production in lymphocytes and granulocytes, respectively. Our results indicate that exposure to fine and ultrafine particles derived from indoor sources may have adverse effects on human vascular health. Copyright © 2016 The Authors. Published by Elsevier

  20. Identification of oocyte progenitor cells in the zebrafish ovary.

    PubMed

    Draper, Bruce W

    2012-01-01

    Zebrafish breed year round and females are capable of producing thousands of eggs during their lifetime. This amazing fecundity is due to the fact that the adult ovary, contains premeiotic oocyte progenitor cells, called oogonia, which produce a continuous supply of new oocytes throughout adult life. Oocyte progenitor cells can be easily identified based on their expression of Vasa, and their characteristic nuclear morphology. Thus, the zebrafish ovary provides a unique and powerful system to study the genetic regulation of oocyte production in a vertebrate animal. A method is presented here for identifying oocyte progenitor cells in the zebrafish ovary using whole-mount confocal immunofluorescence that is simple and accurate.

  1. Immunocytochemical characterisation of neural stem-progenitor cells from green terror cichlid Aequidens rivulatus.

    PubMed

    Wen, C M; Chen, M M; Nan, F H; Wang, C S

    2017-01-01

    In this study, cultures of neural stem-progenitor cells (NSPC) from the brain of green terror cichlid Aequidens rivulatus were established and various NSPCs were demonstrated using immunocytochemistry. All of the NSPCs expressed brain lipid-binding protein, dopamine- and cAMP-regulated neuronal phosphoprotein 32 (DARPP-32), oligodendrocyte transcription factor 2, paired box 6 and sex determining region Y-box 2. The intensity and localisation of these proteins, however, varied among the different NSPCs. Despite being intermediate cells, NSPCs can be divided into radial glial cells, oligodendrocyte progenitor cells (OPC) and neuroblasts by expressing the astrocyte marker glial fibrillary acidic protein (GFAP), OPC marker A2B5 and neuronal markers, including acetyl-tubulin, βIII-tubulin, microtubule-associated protein 2 and neurofilament protein. Nevertheless, astrocytes were polymorphic and were the most dominant cells in the NSPC cultures. By using Matrigel, radial glia exhibiting a long GFAP + or DARPP-32 + fibre and neurons exhibiting a significant acetyl-tubulin + process were obtained. The results confirmed that NSPCs obtained from A. rivulatus brains can proliferate and differentiate into neurons in vitro. Clonal culture can be useful for further studying the distinct NSPCs. © 2016 The Fisheries Society of the British Isles.

  2. Concurrent generation of functional smooth muscle and endothelial cells via a vascular progenitor.

    PubMed

    Marchand, Melanie; Anderson, Erica K; Phadnis, Smruti M; Longaker, Michael T; Cooke, John P; Chen, Bertha; Reijo Pera, Renee A

    2014-01-01

    Smooth muscle cells (SMCs) and endothelial cells (ECs) are typically derived separately, with low efficiencies, from human pluripotent stem cells (hPSCs). The concurrent generation of these cell types might lead to potential applications in regenerative medicine to model, elucidate, and eventually treat vascular diseases. Here we report a robust two-step protocol that can be used to simultaneously generate large numbers of functional SMCs and ECs from a common proliferative vascular progenitor population via a two-dimensional culture system. We show here that coculturing hPSCs with OP9 cells in media supplemented with vascular endothelial growth factor, basic fibroblast growth factor, and bone morphogenetic protein 4 yields a higher percentage of CD31(+)CD34(+) cells on day 8 of differentiation. Upon exposure to endothelial differentiation media and SM differentiation media, these vascular progenitors were able to differentiate and mature into functional endothelial cells and smooth muscle cells, respectively. Furthermore, we were able to expand the intermediate population more than a billion fold to generate sufficient numbers of ECs and SMCs in parallel for potential therapeutic transplantations.

  3. SOX2 is sequentially required for progenitor proliferation and lineage specification in the developing pituitary

    PubMed Central

    Goldsmith, Sam

    2016-01-01

    Sox2 mutations are associated with pituitary hormone deficiencies and the protein is required for pituitary progenitor proliferation, but its function has not been well characterized in this context. SOX2 is known to activate expression of Six6, encoding a homeodomain transcription factor, in the ventral diencephalon. Here, we find that the same relationship likely exists in the pituitary. Moreover, because Six6 deletion is associated with a similar phenotype as described here for loss of Sox2, Six6 appears to be an essential downstream target of SOX2 in the gland. We also uncover a second role for SOX2. Whereas cell differentiation is reduced in Sox2 mutants, some endocrine cells are generated, such as POMC-positive cells in the intermediate lobe. However, loss of SOX2 here results in complete downregulation of the melanotroph pioneer factor PAX7, and subsequently a switch of identity from melanotrophs to ectopic corticotrophs. Rescuing proliferation by ablating the cell cycle negative regulator p27 (also known as Cdkn1b) in Sox2 mutants does not restore melanotroph emergence. Therefore, SOX2 has two independent roles during pituitary morphogenesis; firstly, promotion of progenitor proliferation, and subsequently, acquisition of melanotroph identity. PMID:27226320

  4. GHF-1-promoter-targeted immortalization of a somatotropic progenitor cell results in dwarfism in transgenic mice.

    PubMed

    Lew, D; Brady, H; Klausing, K; Yaginuma, K; Theill, L E; Stauber, C; Karin, M; Mellon, P L

    1993-04-01

    During pituitary development, the homeo domain protein GHF-1 is required for generation of somatotropes and lactotropes and for growth hormone (GH) and prolactin (PRL) gene expression. GHF-1 mRNA is detectable several days before the emergence of GH- or PRL-expressing cells, suggesting the existence of a somatotropic progenitor cell in which GHF-1 transcription is first activated. We have immortalized this cell type by using the GHF-1 regulatory region to target SV40 T-antigen (Tag) tumorigenesis in transgenic mice. The GHF-Tag transgene caused developmental entrapment of somatotropic progenitor cells that express GHF-1 but not GH or PRL, resulting in dwarfism. Immortalized cell lines derived from a transgenic pituitary tumor maintain the characteristics of the somato/lactotropic progenitor in that they express GHF-1 mRNA and protein yet fail to activate GH or PRL transcription. Using these cells, we identified an enhancer that activates GHF-1 transcription at this early stage of development yet is inactive in cells representing later developmental stages of the somatotropic lineage or in other cell types. These experiments not only demonstrate the potential for immortalization of developmental progenitor cells using the regulatory regions from cell type-specific transcription factor genes but illustrate the power of such model systems in the study of developmental control.

  5. Identification of a novel putative pancreatic stem/progenitor cell marker DCAMKL-1 in normal mouse pancreas.

    PubMed

    May, Randal; Sureban, Sripathi M; Lightfoot, Stan A; Hoskins, Aimee B; Brackett, Daniel J; Postier, Russell G; Ramanujam, Rama; Rao, Chinthalapally V; Wyche, James H; Anant, Shrikant; Houchen, Courtney W

    2010-08-01

    Stem cells are critical in maintaining adult homeostasis and have been proposed to be the origin of many solid tumors, including pancreatic cancer. Here we demonstrate the expression patterns of the putative intestinal stem cell marker DCAMKL-1 in the pancreas of uninjured C57BL/6 mice compared with other pancreatic stem/progenitor cell markers. We then determined the viability of isolated pancreatic stem/progenitor cells in isotransplantation assays following DCAMKL-1 antibody-based cell sorting. Sorted cells were grown in suspension culture and injected into the flanks of athymic nude mice. Here we report that DCAMKL-1 is expressed in the main pancreatic duct epithelia and islets, but not within acinar cells. Coexpression was observed with somatostatin, NGN3, and nestin, but not glucagon or insulin. Isolated DCAMKL-1+ cells formed spheroids in suspension culture and induced nodule formation in isotransplantation assays. Analysis of nodules demonstrated markers of early pancreatic development (PDX-1), glandular epithelium (cytokeratin-14 and Ep-CAM), and isletlike structures (somatostatin and secretin). These data taken together suggest that DCAMKL-1 is a novel putative stem/progenitor marker, can be used to isolate normal pancreatic stem/progenitors, and potentially regenerates pancreatic tissues. This may represent a novel tool for regenerative medicine and a target for anti-stem cell-based therapeutics in pancreatic cancer.

  6. Identification of a novel putative pancreatic stem/progenitor cell marker DCAMKL-1 in normal mouse pancreas

    PubMed Central

    May, Randal; Sureban, Sripathi M.; Lightfoot, Stan A.; Hoskins, Aimee B.; Brackett, Daniel J.; Postier, Russell G.; Ramanujam, Rama; Rao, Chinthalapally V.; Wyche, James H.; Anant, Shrikant

    2010-01-01

    Stem cells are critical in maintaining adult homeostasis and have been proposed to be the origin of many solid tumors, including pancreatic cancer. Here we demonstrate the expression patterns of the putative intestinal stem cell marker DCAMKL-1 in the pancreas of uninjured C57BL/6 mice compared with other pancreatic stem/progenitor cell markers. We then determined the viability of isolated pancreatic stem/progenitor cells in isotransplantation assays following DCAMKL-1 antibody-based cell sorting. Sorted cells were grown in suspension culture and injected into the flanks of athymic nude mice. Here we report that DCAMKL-1 is expressed in the main pancreatic duct epithelia and islets, but not within acinar cells. Coexpression was observed with somatostatin, NGN3, and nestin, but not glucagon or insulin. Isolated DCAMKL-1+ cells formed spheroids in suspension culture and induced nodule formation in isotransplantation assays. Analysis of nodules demonstrated markers of early pancreatic development (PDX-1), glandular epithelium (cytokeratin-14 and Ep-CAM), and isletlike structures (somatostatin and secretin). These data taken together suggest that DCAMKL-1 is a novel putative stem/progenitor marker, can be used to isolate normal pancreatic stem/progenitors, and potentially regenerates pancreatic tissues. This may represent a novel tool for regenerative medicine and a target for anti-stem cell-based therapeutics in pancreatic cancer. PMID:20522640

  7. Luminal Progenitors Restrict Their Lineage Potential during Mammary Gland Development

    PubMed Central

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

    2015-01-01

    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. PMID:25688859

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

    PubMed

    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.

  9. Reporter-Based Isolation of Developmental Myogenic Progenitors

    PubMed Central

    Kheir, Eyemen; Cusella, Gabriella; Messina, Graziella; Cossu, Giulio; Biressi, Stefano

    2018-01-01

    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. PMID:29674978

  10. Endothelial progenitor cells in chronic obstructive pulmonary disease and emphysema

    PubMed Central

    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

  11. Identification, Characterization, and Utilization of Adult Meniscal Progenitor Cells

    DTIC Science & Technology

    2015-09-01

    pluripotent stem cells for osteoarthritis drug screening . Arthritis Rheumatol. 66, 3062–3072. Xia, Y., Zheng, S., Bidthanapally, A., 2008. Depth-dependent...the development of knee osteoarthritis (OA). New treatments centered on the stem /progenitor cell population resident within the adult meniscus will be...biology to develop a profile of repair cells in the adult meniscus, track meniscal stem /progenitor cell (MSPC) behavior within meniscus as function of

  12. Identification, Characterization, and Utilization of Adult Meniscal Progenitor Cells

    DTIC Science & Technology

    2015-09-01

    the development of knee osteoarthritis (OA). New treatments centered on the stem/progenitor cell population resident within the adult meniscus will be...cells, stem cells, progenitor cells, meniscus healing, meniscus repair, osteoarthritis 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT...changes that occur after injury. As a result, meniscal injuries are a common underlying cause of post-traumatic osteoarthritis . This is particularly

  13. Ultra-stripped supernovae: progenitors and fate

    NASA Astrophysics Data System (ADS)

    Tauris, Thomas M.; Langer, Norbert; Podsiadlowski, Philipp

    2015-08-01

    The explosion of ultra-stripped stars in close binaries can lead to ejecta masses <0.1 M⊙ and may explain some of the recent discoveries of weak and fast optical transients. In Tauris et al., it was demonstrated that helium star companions to neutron stars (NSs) may experience mass transfer and evolve into naked ˜1.5 M⊙ metal cores, barely above the Chandrasekhar mass limit. Here, we elaborate on this work and present a systematic investigation of the progenitor evolution leading to ultra-stripped supernovae (SNe). In particular, we examine the binary parameter space leading to electron-capture (EC SNe) and iron core-collapse SNe (Fe CCSNe), respectively, and determine the amount of helium ejected with applications to their observational classification as Type Ib or Type Ic. We mainly evolve systems where the SN progenitors are helium star donors of initial mass MHe = 2.5-3.5 M⊙ in tight binaries with orbital periods of Porb = 0.06-2.0 d, and hosting an accreting NS, but we also discuss the evolution of wider systems and of both more massive and lighter - as well as single - helium stars. In some cases, we are able to follow the evolution until the onset of silicon burning, just a few days prior to the SN explosion. We find that ultra-stripped SNe are possible for both EC SNe and Fe CCSNe. EC SNe only occur for MHe = 2.60-2.95 M⊙ depending on Porb. The general outcome, however, is an Fe CCSN above this mass interval and an ONeMg or CO white dwarf for smaller masses. For the exploding stars, the amount of helium ejected is correlated with Porb - the tightest systems even having donors being stripped down to envelopes of less than 0.01 M⊙. We estimate the rise time of ultra-stripped SNe to be in the range 12 h-8 d, and light-curve decay times between 1 and 50 d. A number of fitting formulae for our models are provided with applications to population synthesis. Ultra-stripped SNe may produce NSs in the mass range 1.10-1.80 M⊙ and are highly relevant for

  14. Biology and flow cytometry of proangiogenic hematopoietic progenitors cells.

    PubMed

    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.

  15. Muscle: a source of progenitor cells for bone fracture healing.

    PubMed

    Henrotin, Yves

    2011-12-22

    Bone repair failure is a major complication of open fracture, leading to non-union of broken bone extremities and movement at the fracture site. This results in a serious disability for patients. The role played by the periosteum and bone marrow progenitors in bone repair is now well documented. In contrast, limited information is available on the role played by myogenic progenitor cells in bone repair. In a recent article published in BMC Musculoskeletal Disorders, Liu et al. compared the presence of myogenic progenitor (MyoD lineage cells) in closed and open fractures. They showed that myogenic progenitors are present in open, but not closed fractures, suggesting that muscle satellite cells may colonize the fracture site in the absence of intact periosteum. Interestingly, these progenitors sequentially expressed a chondrogenic and, thereafter, an osteoblastic phenotype, suggestive of a functional role in the repair process. This finding opens up new perspectives for the research of orthopedic surgical methods, which could maximize myogenic progenitor access and mobilization to augment bone repair. Please see related article: http://www.biomedcentral.com/1471-2474/12/288.

  16. ZFOURGE/CANDELS: On the Evolution of M* Galaxy Progenitors from z = 3 to 0.5

    NASA Astrophysics Data System (ADS)

    Papovich, C.; Labbé, I.; Quadri, R.; Tilvi, V.; Behroozi, P.; Bell, E. F.; Glazebrook, K.; Spitler, L.; Straatman, C. M. S.; Tran, K.-V.; Cowley, M.; Davé, R.; Dekel, A.; Dickinson, M.; Ferguson, H. C.; Finkelstein, S. L.; Gawiser, E.; Inami, H.; Faber, S. M.; Kacprzak, G. G.; Kawinwanichakij, L.; Kocevski, D.; Koekemoer, A.; Koo, D. C.; Kurczynski, P.; Lotz, J. M.; Lu, Y.; Lucas, R. A.; McIntosh, D.; Mehrtens, N.; Mobasher, B.; Monson, A.; Morrison, G.; Nanayakkara, T.; Persson, S. E.; Salmon, B.; Simons, R.; Tomczak, A.; van Dokkum, P.; Weiner, B.; Willner, S. P.

    2015-04-01

    Galaxies with stellar masses near M* contain the majority of stellar mass in the universe, and are therefore of special interest in the study of galaxy evolution. The Milky Way (MW) and Andromeda (M31) have present-day stellar masses near M*, at 5 × 1010 M ⊙ (defined here to be MW-mass) and 1011 M ⊙ (defined to be M31-mass). We study the typical progenitors of these galaxies using the FOURSTAR Galaxy Evolution Survey (ZFOURGE). ZFOURGE is a deep medium-band near-IR imaging survey, which is sensitive to the progenitors of these galaxies out to z ~ 3. We use abundance-matching techniques to identify the main progenitors of these galaxies at higher redshifts. We measure the evolution in the stellar mass, rest-frame colors, morphologies, far-IR luminosities, and star formation rates, combining our deep multiwavelength imaging with near-IR Hubble Space Telescope imaging from Cosmic Near-IR Deep Extragalactic Legacy Survey (CANDELS), and Spitzer and Herschel far-IR imaging from Great Observatories Origins Deep Survey-Herschel and CANDELS-Herschel. The typical MW-mass and M31-mass progenitors passed through the same evolution stages, evolving from blue, star-forming disk galaxies at the earliest stages to redder dust-obscured IR-luminous galaxies in intermediate stages and to red, more quiescent galaxies at their latest stages. The progenitors of the MW-mass galaxies reached each evolutionary stage at later times (lower redshifts) and with stellar masses that are a factor of two to three lower than the progenitors of the M31-mass galaxies. The process driving this evolution, including the suppression of star formation in present-day M* galaxies, requires an evolving stellar-mass/halo-mass ratio and/or evolving halo-mass threshold for quiescent galaxies. The effective size and SFRs imply that the baryonic cold-gas fractions drop as galaxies evolve from high redshift to z ~ 0 and are strongly anticorrelated with an increase in the Sérsic index. Therefore, the growth

  17. p53 Enables metabolic fitness and self-renewal of nephron progenitor cells.

    PubMed

    Li, Yuwen; Liu, Jiao; Li, Wencheng; Brown, Aaron; Baddoo, Melody; Li, Marilyn; Carroll, Thomas; Oxburgh, Leif; Feng, Yumei; Saifudeen, Zubaida

    2015-04-01

    Contrary to its classic role in restraining cell proliferation, we demonstrate here a divergent function of p53 in the maintenance of self-renewal of the nephron progenitor pool in the embryonic mouse kidney. Nephron endowment is regulated by progenitor availability and differentiation potential. Conditional deletion of p53 in nephron progenitor cells (Six2Cre(+);p53(fl/fl)) induces progressive depletion of Cited1(+)/Six2(+) self-renewing progenitors and loss of cap mesenchyme (CM) integrity. The Six2(p53-null) CM is disorganized, with interspersed stromal cells and an absence of a distinct CM-epithelia and CM-stroma interface. Impaired cell adhesion and epithelialization are indicated by decreased E-cadherin and NCAM expression and by ineffective differentiation in response to Wnt induction. The Six2Cre(+);p53(fl/fl) cap has 30% fewer Six2(GFP(+)) cells. Apoptotic index is unchanged, whereas proliferation index is significantly reduced in accordance with cell cycle analysis showing disproportionately fewer Six2Cre(+);p53(fl/fl) cells in the S and G2/M phases compared with Six2Cre(+);p53(+/+) cells. Mutant kidneys are hypoplastic with fewer generations of nascent nephrons. A significant increase in mean arterial pressure is observed in early adulthood in both germline and conditional Six2(p53-null) mice, linking p53-mediated defects in kidney development to hypertension. RNA-Seq analyses of FACS-isolated wild-type and Six2(GFP(+)) CM cells revealed that the top downregulated genes in Six2Cre(+);p53(fl/fl) CM belong to glucose metabolism and adhesion and/or migration pathways. Mutant cells exhibit a ∼ 50% decrease in ATP levels and a 30% decrease in levels of reactive oxygen species, indicating energy metabolism dysfunction. In summary, our data indicate a novel role for p53 in enabling the metabolic fitness and self-renewal of nephron progenitors. © 2015. Published by The Company of Biologists Ltd.

  18. Intermediate tax sanctions: an overview.

    PubMed

    Peregrine, M W

    1997-07-01

    New federal tax law applies intermediate tax sanctions when tax-exempt organizations enter into so-called excess benefit transactions with corporate insiders. The sanctions take the form of a two-tiered penalty excise tax, which is assessed not on the tax-exempt organization itself but on the insider who receives the excess benefit and the organizational managers and board members who knowingly participate in an improper transaction. The intermediate tax sanctions, therefore, present tax-planning challenges for tax-exempt hospitals and integrated delivery systems as well as for 501(c)(4) HMOs. Forthcoming treasury regulations are expected to add clarity to the new law.

  19. Metabotropic glutamate receptor 5 responses dictate differentiation of neural progenitors to NMDA-responsive cells in fragile X syndrome.

    PubMed

    Achuta, Venkat Swaroop; Grym, Heli; Putkonen, Noora; Louhivuori, Verna; Kärkkäinen, Virve; Koistinaho, Jari; Roybon, Laurent; Castrén, Maija L

    2017-04-01

    Disrupted metabotropic glutamate receptor 5 (mGluR5) signaling is implicated in many neuropsychiatric disorders, including autism spectrum disorder, found in fragile X syndrome (FXS). Here we report that intracellular calcium responses to the group I mGluR agonist (S)-3,5-dihydroxyphenylglycine (DHPG) are augmented, and calcium-dependent mGluR5-mediated mechanisms alter the differentiation of neural progenitors in neurospheres derived from human induced pluripotent FXS stem cells and the brains of mouse model of FXS. Treatment with the mGluR5 antagonist 2-methyl-6-(phenylethynyl)-pyridine (MPEP) prevents an abnormal clustering of DHPG-responsive cells that are responsive to activation of ionotropic receptors in mouse FXS neurospheres. MPEP also corrects morphological defects of differentiated cells and enhanced migration of neuron-like cells in mouse FXS neurospheres. Unlike in mouse neurospheres, MPEP increases the differentiation of DHPG-responsive radial glial cells as well as the subpopulation of cells responsive to both DHPG and activation of ionotropic receptors in human neurospheres. However, MPEP normalizes the FXS-specific increase in the differentiation of cells responsive only to N-methyl-d-aspartate (NMDA) present in human neurospheres. Exposure to MPEP prevents the accumulation of intermediate basal progenitors in embryonic FXS mouse brain suggesting that rescue effects of GluR5 antagonist are progenitor type-dependent and species-specific differences of basal progenitors may modify effects of MPEP on the cortical development. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 419-437, 2017. © 2016 Wiley Periodicals, Inc.

  20. Role of liver progenitors in liver regeneration

    PubMed Central

    Best, Jan; Manka, Paul; Syn, Wing-Kin; Dollé, Laurent; van Grunsven, Leo A.

    2015-01-01

    During massive liver injury and hepatocyte loss, the intrinsic regenerative capacity of the liver by replication of resident hepatocytes is overwhelmed. Treatment of this condition depends on the cause of liver injury, though in many cases liver transplantation (LT) remains the only curative option. LT for end stage chronic and acute liver diseases is hampered by shortage of donor organs and requires immunosuppression. Hepatocyte transplantation is limited by yet unresolved technical difficulties. Since currently no treatment is available to facilitate liver regeneration directly, therapies involving the use of resident liver stem or progenitor cells (LPCs) or non-liver stem cells are coming to fore. LPCs are quiescent in the healthy liver, but may be activated under conditions where the regenerative capacity of mature hepatocytes is severely impaired. Non-liver stem cells include embryonic stem cells (ES cells) and mesenchymal stem cells (MSCs). In the first section, we aim to provide an overview of the role of putative cytokines, growth factors, mitogens and hormones in regulating LPC response and briefly discuss the prognostic value of the LPC response in clinical practice. In the latter section, we will highlight the role of other (non-liver) stem cells in transplantation and discuss advantages and disadvantages of ES cells, induced pluripotent stem cells (iPS), as well as MSCs. PMID:25713804

  1. Stromalized microreactor supports murine hematopoietic progenitor enrichment.

    PubMed

    Khong, Danika; Li, Matthew; Singleton, Amy; Chin, Ling-Yee; Parekkadan, Biju

    2018-01-20

    There is an emerging need to process, expand, and even genetically engineer hematopoietic stem and progenitor cells (HSPCs) prior to administration for blood reconstitution therapy. A closed-system and automated solution for ex vivo HSC processing can improve adoption and standardize processing techniques. Here, we report a recirculating flow bioreactor where HSCs are stabilized and enriched for short-term processing by indirect fibroblast feeder coculture. Mouse 3 T3 fibroblasts were seeded on the extraluminal membrane surface of a hollow fiber micro-bioreactor and were found to support HSPC cell number compared to unsupported BMCs. CFSE analysis indicates that 3 T3-support was essential for the enhanced intrinsic cell cycling of HSPCs. This enhanced support was specific to the HSPC population with little to no effect seen with the Lineage positive and Lineage negative cells. Together, these data suggest that stromal-seeded hollow fiber micro-reactors represent a platform to screening various conditions that support the expansion and bioprocessing of HSPCs ex vivo.

  2. Endothelial Progenitor Cells and Kidney Diseases.

    PubMed

    Ozkok, Abdullah; Yildiz, Alaattin

    2018-05-10

    Endothelial progenitor cells (EPC) are bone marrow derived or tissue-resident cells that play major roles in the maintenance of vascular integrity and repair of endothelial damage. Although EPCs may be capable of directly engrafting and regenerating the endothelium, the most important effects of EPCs seem to be depended on paracrine effects. In recent studies, specific microvesicles and mRNAs have been found to mediate the pro-angiogenic and regenerative effects of EPCs on endothelium. EPC counts have important prognostic implications in cardiovascular diseases (CVD). Uremia and inflammation are associated with lower EPC counts which probably contribute to increased CVD risks in patients with chronic kidney disease. Beneficial effects of the EPC therapies have been shown in studies performed on different models of CVD and kidney diseases such as acute and chronic kidney diseases and glomerulonephritis. However, lack of a clear definition and specific marker of EPCs is the most important problem causing difficulties in interpretation of the results of the studies investigating EPCs. © 2018 The Author(s). Published by S. Karger AG, Basel.

  3. Role of liver progenitors in liver regeneration.

    PubMed

    Best, Jan; Manka, Paul; Syn, Wing-Kin; Dollé, Laurent; van Grunsven, Leo A; Canbay, Ali

    2015-02-01

    During massive liver injury and hepatocyte loss, the intrinsic regenerative capacity of the liver by replication of resident hepatocytes is overwhelmed. Treatment of this condition depends on the cause of liver injury, though in many cases liver transplantation (LT) remains the only curative option. LT for end stage chronic and acute liver diseases is hampered by shortage of donor organs and requires immunosuppression. Hepatocyte transplantation is limited by yet unresolved technical difficulties. Since currently no treatment is available to facilitate liver regeneration directly, therapies involving the use of resident liver stem or progenitor cells (LPCs) or non-liver stem cells are coming to fore. LPCs are quiescent in the healthy liver, but may be activated under conditions where the regenerative capacity of mature hepatocytes is severely impaired. Non-liver stem cells include embryonic stem cells (ES cells) and mesenchymal stem cells (MSCs). In the first section, we aim to provide an overview of the role of putative cytokines, growth factors, mitogens and hormones in regulating LPC response and briefly discuss the prognostic value of the LPC response in clinical practice. In the latter section, we will highlight the role of other (non-liver) stem cells in transplantation and discuss advantages and disadvantages of ES cells, induced pluripotent stem cells (iPS), as well as MSCs.

  4. TWEAK induces liver progenitor cell proliferation

    PubMed Central

    Jakubowski, Aniela; Ambrose, Christine; Parr, Michael; Lincecum, John M.; Wang, Monica Z.; Zheng, Timothy S.; Browning, Beth; Michaelson, Jennifer S.; Baestcher, Manfred; Wang, Bruce; Bissell, D. Montgomery; Burkly, Linda C.

    2005-01-01

    Progenitor (“oval”) cell expansion accompanies many forms of liver injury, including alcohol toxicity and submassive parenchymal necrosis as well as experimental injury models featuring blocked hepatocyte replication. Oval cells can potentially become either hepatocytes or biliary epithelial cells and may be critical to liver regeneration, particularly when hepatocyte replication is impaired. The regulation of oval cell proliferation is incompletely understood. Herein we present evidence that a TNF family member called TWEAK (TNF-like weak inducer of apoptosis) stimulates oval cell proliferation in mouse liver through its receptor Fn14. TWEAK has no effect on mature hepatocytes and thus appears to be selective for oval cells. Transgenic mice overexpressing TWEAK in hepatocytes exhibit periportal oval cell hyperplasia. A similar phenotype was obtained in adult wild-type mice, but not Fn14-null mice, by administering TWEAK-expressing adenovirus. Oval cell expansion induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) was significantly reduced in Fn14-null mice as well as in adult wild-type mice with a blocking anti-TWEAK mAb. Importantly, TWEAK stimulated the proliferation of an oval cell culture model. Finally, we show increased Fn14 expression in chronic hepatitis C and other human liver diseases relative to its expression in normal liver, which suggests a role for the TWEAK/Fn14 pathway in human liver injury. We conclude that TWEAK has a selective mitogenic effect for liver oval cells that distinguishes it from other previously described growth factors. PMID:16110324

  5. Possible Progenitor of Special Supernova Type Detected

    NASA Astrophysics Data System (ADS)

    2008-04-01

    caused by material being pulled off a companion star onto the white dwarf, fusion of this material on the surface of the star should heat the star and produce a strong source of X-radiation prior to the explosion. Once the supernova explosion occurs, the white dwarf is expected to be completely destroyed and then would be undetectable in X-rays. In the merger scenario, the intensity of X-ray emission prior to the explosion is expected to be much weaker. Based on the detection of a fairly strong X-ray source at approximately the position of SN 2007on 4 years before the explosion, Voss and Nelemans conclude that the data support the scenario where matter is pulled off a companion star. The small number of X-ray sources in the field implies that there is only a small chance of an unrelated source being so close by coincidence. Also, the X-ray source has similar properties to those expected for fusion on a white dwarf, unlike most X-ray sources in the sky. However, in follow-up studies, Voss, Nelemans and colleagues Gijs Roelofs (Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass.) and Cees Bassa (McGill University, Canada) used higher-quality optical images to better determine the supernova's position. This work, which is not yet published, shows a small, but significant difference in the measured positions of the supernova and the X-ray source, suggesting the source may not be the progenitor. Follow-up Chandra observations hint that the X-ray object has disappeared, but further observations are needed to finally decide whether the source was the progenitor or not. The team is also applying this new method to other supernovas and has high hopes that they will eventually succeed in identifying the elusive cause of at least some of these explosions. "We're very excited about opening up a new way of studying supernovas, even though we're not sure that we've seen this particular stellar bomb before it exploded," said Gijs Roelofs. "We're very confident that we

  6. Loss of the tumor suppressor p15Ink4b enhances myeloid progenitor formation from common myeloid progenitors.

    PubMed

    Rosu-Myles, Michael; Taylor, Barbara J; Wolff, Linda

    2007-03-01

    The tumor suppressor p15Ink4b (Ink4b) is a cell-cycle inhibitor that is inactivated in a high percentage of acute myeloid leukemia and myeloid dysplasia syndrome cases. Despite this, the role of Ink4b in hematopoiesis remains unclear. Here we examined the role of Ink4b in blood cell formation using Ink4b-deficient (Ink4b(-/-)) mice. We compared the bone marrow (BM) of Ink4b(-/-) and wild-type mice using flow cytometric, colony-forming unit and competitive repopulating assays (CRA). The proliferation, differentiation, self-renewal, and apoptosis of progenitor cells were further compared by in vitro and in vivo methods. BM from Ink4b(-/-) mice contained increased numbers of granulocyte-monocyte progenitors and Gr-1(+) cells and showed a competitive advantage over wild-type cells in myeloid cell formation by CRA. Ink4b(-/-) progenitors did not demonstrate increased proliferation, self-renewing potential, or reduced apoptosis. Instead, Ink4b(-/-) common myeloid progenitors (CMPs) showed increased myeloid progenitor formation concomitant with reduced erythroid potential. This work establishes a role for Ink4b in regulating the differentiation of CMPs and indicates that loss of Ink4b enhances the formation of myeloid progenitors.

  7. Supernovae with two peaks in the optical light curve and the signature of progenitors with low-mass extended envelopes

    SciTech Connect

    Nakar, Ehud; Piro, Anthony L.

    2014-06-20

    Early observations of supernova light curves are powerful tools for shedding light on the pre-explosion structures of their progenitors and their mass-loss histories just prior to explosion. Some core-collapse supernovae that are detected during the first days after the explosion prominently show two peaks in the optical bands, including the R and I bands, where the first peak appears to be powered by the cooling of shocked surface material and the second peak is clearly powered by radioactive decay. Such light curves have been explored in detail theoretically for SN 1993J and 2011dh, where it was found that they maymore » be explained by progenitors with extended, low-mass envelopes. Here, we generalize these results. We first explore whether any double-peaked light curve of this type can be generated by a progenitor with a 'standard' density profile, such as a red supergiant or a Wolf-Rayet star. We show that a standard progenitor (1) cannot produce a double-peaked light curve in the R and I bands and (2) cannot exhibit a fast drop in the bolometric luminosity as is seen after the first peak. We then explore the signature of a progenitor with a compact core surrounded by extended, low-mass material. This may be a hydrostatic low-mass envelope or material ejected just prior to the explosion. We show that it naturally produces both of these features. We use this result to provide simple formulae to estimate (1) the mass of the extended material from the time of the first peak, (2) the extended material radius from the luminosity of the first peak, and (3) an upper limit on the core radius from the luminosity minimum between the two peaks.« less

  8. 8-Oxoguanine DNA glycosylase 1 (ogg1) maintains the function of cardiac progenitor cells during heart formation in zebrafish

    SciTech Connect

    Yan, Lifeng; Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 210029; Zhou, Yong

    Genomic damage may devastate the potential of progenitor cells and consequently impair early organogenesis. We found that ogg1, a key enzyme initiating the base-excision repair, was enriched in the embryonic heart in zebrafish. So far, little is known about DNA repair in cardiogenesis. Here, we addressed the critical role of ogg1 in cardiogenesis for the first time. ogg1 mainly expressed in the anterior lateral plate mesoderm (ALPM), the primary heart tube, and subsequently the embryonic myocardium by in situ hybridisation. Loss of ogg1 resulted in severe cardiac morphogenesis and functional abnormalities, including the short heart length, arrhythmia, decreased cardiomyocytes andmore » nkx2.5{sup +} cardiac progenitor cells. Moreover, the increased apoptosis and repressed proliferation of progenitor cells caused by ogg1 deficiency might contribute to the heart phenotype. The microarray analysis showed that the expression of genes involved in embryonic heart tube morphogenesis and heart structure were significantly changed due to the lack of ogg1. Among those, foxh1 is an important partner of ogg1 in the cardiac development in response to DNA damage. Our work demonstrates the requirement of ogg1 in cardiac progenitors and heart development in zebrafish. These findings may be helpful for understanding the aetiology of congenital cardiac deficits. - Highlights: • A key DNA repair enzyme ogg1 is expressed in the embryonic heart in zebrafish. • We found that ogg1 is essential for normal cardiac morphogenesis in zebrafish. • The production of embryonic cardiomyocytes requires appropriate ogg1 expression. • Ogg1 critically regulated proliferation of cardiac progenitor cells in zebrafish. • foxh1 is a partner of ogg1 in the cardiac development in response to DNA damage.« less

  9. Material Voices: Intermediality and Autism

    ERIC Educational Resources Information Center

    Trimingham, Melissa; Shaughnessy, Nicola

    2016-01-01

    Autism continues to be regarded enigmatically; a community that is difficult to access due to perceived disruptions of interpersonal connectedness. Through detailed observations of two children participating in the Arts and Humanities Research Council funded project "Imagining Autism: Drama, Performance and Intermediality as Interventions for…

  10. Cestina pro Pokrocile (Intermediate Czech).

    ERIC Educational Resources Information Center

    Kabat, Grazyna; And Others

    The textbook in intermediate Czech is designed for second-year students of the language and those who already have a basic knowledge of Czech grammar and vocabulary. It is appropriate for use in a traditional college language classroom, the business community, or a government language school. It can be covered in a year-long conventional…

  11. Intermediality and the Child Performer

    ERIC Educational Resources Information Center

    Budd, Natasha

    2016-01-01

    This report details examples of praxis in the creation and presentation of "Joy Fear and Poetry": an intermedial theatre performance in which children aged 7-12 years generated aesthetic gestures using a range of new media forms. The impetus for the work's development was a desire to make an intervention into habituated patterns of…

  12. AIDS Elementary/Intermediate Curriculum.

    ERIC Educational Resources Information Center

    Kellogg, Nancy Rader

    This Acquired Immune Deficiency Syndrome (AIDS) Curriculum was developed for intermediate elementary (5th, 6th, and 7th grade) students. It is an integrated unit that encompasses health, science, social studies, math, and language arts. The curriculum is comprised of nine class activities designed to meet the following objectives: (1) to determine…

  13. The Bicoid Class Homeodomain Factors ceh-36/OTX and unc-30/PITX Cooperate in C. elegans Embryonic Progenitor Cells to Regulate Robust Development

    PubMed Central

    Walton, Travis; Preston, Elicia; Nair, Gautham; Zacharias, Amanda L.; Raj, Arjun; Murray, John Isaac

    2015-01-01

    While many transcriptional regulators of pluripotent and terminally differentiated states have been identified, regulation of intermediate progenitor states is less well understood. Previous high throughput cellular resolution expression studies identified dozens of transcription factors with lineage-specific expression patterns in C. elegans embryos that could regulate progenitor identity. In this study we identified a broad embryonic role for the C. elegans OTX transcription factor ceh-36, which was previously shown to be required for the terminal specification of four neurons. ceh-36 is expressed in progenitors of over 30% of embryonic cells, yet is not required for embryonic viability. Quantitative phenotyping by computational analysis of time-lapse movies of ceh-36 mutant embryos identified cell cycle or cell migration defects in over 100 of these cells, but most defects were low-penetrance, suggesting redundancy. Expression of ceh-36 partially overlaps with that of the PITX transcription factor unc-30. unc-30 single mutants are viable but loss of both ceh-36 and unc-30 causes 100% lethality, and double mutants have significantly higher frequencies of cellular developmental defects in the cells where their expression normally overlaps. These factors are also required for robust expression of the downstream developmental regulator mls-2/HMX. This work provides the first example of genetic redundancy between the related yet evolutionarily distant OTX and PITX families of bicoid class homeodomain factors and demonstrates the power of quantitative developmental phenotyping in C. elegans to identify developmental regulators acting in progenitor cells. PMID:25738873

  14. EVIDENCE FOR A COMPACT WOLF-RAYET PROGENITOR FOR THE TYPE Ic SUPERNOVA PTF 10vgv

    SciTech Connect

    Corsi, A.; Ofek, E. O.; Gal-Yam, A.

    We present the discovery of PTF 10vgv, a Type Ic supernova (SN) detected by the Palomar Transient Factory, using the Palomar 48 inch telescope (P48). R-band observations of the PTF 10vgv field with P48 probe the SN emission from its very early phases (about two weeks before R-band maximum) and set limits on its flux in the week prior to the discovery. Our sensitive upper limits and early detections constrain the post-shock-breakout luminosity of this event. Via comparison to numerical (analytical) models, we derive an upper-limit of R {approx}< 4.5 R{sub Sun} (R {approx}< 1 R{sub Sun }) on themore » radius of the progenitor star, a direct indication in favor of a compact Wolf-Rayet star. Applying a similar analysis to the historical observations of SN 1994I yields R {approx}< 1/4 R{sub Sun} for the progenitor radius of this SN.« less

  15. Physics of intermediate shocks: A review

    NASA Technical Reports Server (NTRS)

    Karimabadi, H.

    1995-01-01

    Intermediate shocks (ISs) lead to a transition from super-Alfvenic to sub-Alfvenic flow and are different from slow and fast shocks in that an IS rotates the component of the magnetic field tangent to the shock plane by 180 deg. Another peculiarity of ISs is that for the same upstream conditions an IS can have two different downstream states. There also exist a second class of ISs which rotate the magnetic field by an angle other than 180 deg. Due to their noncoplanar nature they cannot be time-stationary and are referred to as time-dependent intermediate shocks (TDIS). The existence of ISs has been the subject of much controversy over the years. Early studies questioned the physical reality of ISs. However, the studies of ISs found a new impetus when C.C. Wu showed that ISs do exist and are stable within the resistive MHD framework. In this paper, after a brief historical overview of the subject, we will review the latest developments in the study of ISs. In particular, we will address the questions of stability and structure of ISs and the relationship between ISs and other discontinuities. One of the recent developments has been the finding that ISs can be unsteady, reforming in time. Details of this process will be discussed. Finally, we examine the effect of anisotropy on the resolutions and discuss the relevance of ISs to the observed field rotations at the Earth's magnetopause.

  16. Submillimeter Galaxies as Progenitors of Compact Quiescent Galaxies

    NASA Technical Reports Server (NTRS)

    Toft, S.; Smolcic, V.; Magnelli, B.; Karim, A.; Zirm, A.; Michalowski, M.; Capak, P.; Sheth, K.; Schawinski, K.; Krogager, J.-K.; hide

    2014-01-01

    Three billion years after the big bang (at redshift z = 2), half of the most massive galaxies were already old, quiescent systems with little to no residual star formation and extremely compact with stellar mass densities at least an order of magnitude larger than in low-redshift ellipticals, their descendants. Little is known about how they formed, but their evolved, dense stellar populations suggest formation within intense, compact starbursts 1-2 Gyr earlier (at 3 < z < 6). Simulations show that gas-rich major mergers can give rise to such starbursts, which produce dense remnants. Submillimeter-selected galaxies (SMGs) are prime examples of intense, gas-rich starbursts.With a new, representative spectroscopic sample of compact, quiescent galaxies at z = 2 and a statistically well-understood sample of SMGs, we show that z = 3-6 SMGs are consistent with being the progenitors of z = 2 quiescent galaxies, matching their formation redshifts and their distributions of sizes, stellar masses, and internal velocities. Assuming an evolutionary connection, their space densities also match if the mean duty cycle of SMG starbursts is 42(sup+40) -29 Myr (consistent with independent estimates), which indicates that the bulk of stars in these massive galaxies were formed in a major, early surge of star formation. These results suggest a coherent picture of the formation history of the most massive galaxies in the universe, from their initial burst of violent star formation through their appearance as high stellar-density galaxy cores and to their ultimate fate as giant ellipticals.

  17. Submillimeter Galaxies as Progenitors of Compact Quiescent Galaxies

    NASA Astrophysics Data System (ADS)

    Toft, S.; Smolčić, V.; Magnelli, B.; Karim, A.; Zirm, A.; Michalowski, M.; Capak, P.; Sheth, K.; Schawinski, K.; Krogager, J.-K.; Wuyts, S.; Sanders, D.; Man, A. W. S.; Lutz, D.; Staguhn, J.; Berta, S.; Mccracken, H.; Krpan, J.; Riechers, D.

    2014-02-01

    Three billion years after the big bang (at redshift z = 2), half of the most massive galaxies were already old, quiescent systems with little to no residual star formation and extremely compact with stellar mass densities at least an order of magnitude larger than in low-redshift ellipticals, their descendants. Little is known about how they formed, but their evolved, dense stellar populations suggest formation within intense, compact starbursts 1-2 Gyr earlier (at 3 < z < 6). Simulations show that gas-rich major mergers can give rise to such starbursts, which produce dense remnants. Submillimeter-selected galaxies (SMGs) are prime examples of intense, gas-rich starbursts. With a new, representative spectroscopic sample of compact, quiescent galaxies at z = 2 and a statistically well-understood sample of SMGs, we show that z = 3-6 SMGs are consistent with being the progenitors of z = 2 quiescent galaxies, matching their formation redshifts and their distributions of sizes, stellar masses, and internal velocities. Assuming an evolutionary connection, their space densities also match if the mean duty cycle of SMG starbursts is 42^{+40}_{-29} Myr (consistent with independent estimates), which indicates that the bulk of stars in these massive galaxies were formed in a major, early surge of star formation. These results suggest a coherent picture of the formation history of the most massive galaxies in the universe, from their initial burst of violent star formation through their appearance as high stellar-density galaxy cores and to their ultimate fate as giant ellipticals.

  18. Sub-mm galaxies as progenitors of compact quiescent galaxies

    NASA Astrophysics Data System (ADS)

    Toft, Sune

    2015-08-01

    Three billion years after the big bang (at redshift z=2), half of the most massive galaxies were already old, quiescent systems with little to no residual star formation and extremely compact with stellar mass densities at least an order of magnitude larger than in low redshift ellipticals, their descendants. Little is known about how they formed, but their evolved, dense stellar populations suggest formation within intense, compact starbursts 1-2 Gyr earlier (at 3 < z < 6). Simulations show that gas-rich major mergers can give rise to such starbursts which produce dense remnants. Sub-millimetre selected galaxies (SMGs) are prime examples of intense, gas-rich, starbursts. With a new, mass-complete spectroscopic sample of compact quiescent galaxies at z=2 and a statistically well-understood sample of SMGs, we show that z = 3 -6 SMGs are consistent with being the progenitors of z = 2 quiescent galaxies, matching their formation redshifts and their distributions of sizes, stellar masses and internal velocities. Assuming an evolutionary connection, their space densities also match if the mean duty cycle of SMG starbursts is 42 (+40/-29) Myr (consistent with independent estimates), indicating that the bulk of stars in these massive galaxies were formed in a major, early surge of star-formation. These results suggests a coherent picture of the formation history of the most massive galaxies in the universe, from their initial burst of violent star-formation through their appearance as high stellardensity galaxy cores and to their ultimate fate as giant ellipticals.If time permits i will show novel, spatially resolved spectroscopic observations of the inner regions (r2, allowing for strong new constraints on their formation and evolutionary path

  19. Sun Ginseng Protects Endothelial Progenitor Cells From Senescence Associated Apoptosis

    PubMed Central

    Im, Wooseok; Chung, Jin-Young; Bhan, Jaejun; Lim, Jiyeon; Lee, Soon-Tae; Chu, Kon; Kim, Manho

    2012-01-01

    Endothelial progenitor cells (EPC) are a population of cells that circulate in the blood stream. They play a role in angiogenesis and, therefore, can be prognostic markers of vascular repair. Ginsenoside Rg3 prevents endothelial cell apoptosis through the inhibition of the mitochondrial caspase pathway. It also affects estrogen activity, which reduces EPC senescence. Sun ginseng (SG), which is heat-processed ginseng, has a high content of ginsenosides. The purpose of this study was to investigate the protective effects of SG on senescence-associated apoptosis in EPCs. In order to isolate EPCs, mononuclear cells of human blood buffy coats were cultured and characterized by their uptake of acetylated low-density lipoprotein (acLDL) and their binding of Ulex europaeus agglutinin I (ulex-lectin). Flow cytometry with annexin-V staining was performed in order to assess early and late apoptosis. Senescence was determined by β-galactosidase (β-gal) staining. Staining with 4′-6-Diamidino-2-phenylindole verified that most adherent cells (93±2.7%) were acLDL-positive and ulex-lectin-positive. The percentage of β-gal-positive EPCs was decreased from 93.8±2.0% to 62.5±3.6% by SG treatment. A fluorescence-activated cell sorter (FACS) analysis showed that 4.9% of EPCs were late apoptotic in controls. Sun ginseng decreased the apoptotic cell population by 39% in the late stage of apoptosis from control baseline levels. In conclusion, these results show antisenescent and antiapoptotic effects of SG in human-derived EPCs, indicating that SG can enhance EPC-mediated repair mechanisms. PMID:23717107

  20. Nucleostemin Rejuvenates Cardiac Progenitor Cells and Antagonizes Myocardial Aging

    PubMed Central

    Hariharan, Nirmala; Quijada, Pearl; Mohsin, Sadia; Joyo, Anya; Samse, Kaitlen; Monsanto, Megan; De La Torre, Andrea; Avitabile, Daniele; Ormachea, Lucia; McGregor, Michael J.; Tsai, Emily J; Sussman, Mark A.

    2015-01-01

    BACKGROUND Functional decline in stem cell-mediated regeneration contributes to aging associated with cellular senescence in c-kit+ cardiac progenitor cells (CPCs). Clinical implementation of CPC-based therapy with elderly patients would benefit tremendously from understanding molecular characteristics of senescence to antagonize aging. Nucleostemin (NS) is a nucleolar protein regulating stem cell proliferation and pluripotency. OBJECTIVES The goal is to demonstrate that NS preserves characteristics associated with “stemness” in CPCs and antagonizes myocardial senescence and aging. METHODS CPCs isolated from human fetal (FhCPC) and adult failing (AhCPC) hearts, as well as young (YCPC) and old mice (OCPC), were studied for senescence characteristics and NS expression. Heterozygous knockout mice with one functional allele of NS (NS+/−) were used to demonstrate that NS preserves myocardial structure and function and slows characteristics of aging. RESULTS NS expression is decreased in AhCPCs relative to FhCPC, correlating with lowered proliferation potential and shortened telomere length. AhCPC characteristics resemble OCPCs, which have a phenotype induced by NS silencing, resulting in cell flattening, senescence, multinucleated cells, decreased S phase progression, diminished expression of stemness markers and up-regulation of p53 and p16. CPC senescence resulting from NS loss is partially p53 dependent and is rescued by concurrent silencing of p53. Mechanistically, NS induction correlates with Pim-1 kinase-mediated stabilization of c-Myc. Engineering OCPCs and AhCPCs to overexpress NS decreases senescent and multinucleated cells, restores morphology, and antagonizes senescence, thereby preserving phenotypic properties of “stemness.” Early cardiac aging with decline in cardiac function, increase in senescence markers p53 and p16, telomere attrition, and accompanied CPC exhaustion is evident in NS+/− mice. CONCLUSIONS Youthful properties and antagonism of

  1. Neuronal expression of pathological tau accelerates oligodendrocyte progenitor cell differentiation

    PubMed Central

    Ossola, Bernardino; Zhao, Chao; Compston, Alastair; Pluchino, Stefano; Franklin, Robin J. M.

    2015-01-01

    Oligodendrocyte progenitor cell (OPC) differentiation is an important therapeutic target to promote remyelination in multiple sclerosis (MS). We previously reported hyperphosphorylated and aggregated microtubule‐associated protein tau in MS lesions, suggesting its involvement in axonal degeneration. However, the influence of pathological tau‐induced axonal damage on the potential for remyelination is unknown. Therefore, we investigated OPC differentiation in human P301S tau (P301S‐htau) transgenic mice, both in vitro and in vivo following focal demyelination. In 2‐month‐old P301S‐htau mice, which show hyperphosphorylated tau in neurons, we found atrophic axons in the spinal cord in the absence of prominent axonal degeneration. These signs of early axonal damage were associated with microgliosis and an upregulation of IL‐1β and TNFα. Following in vivo focal white matter demyelination we found that OPCs differentiated more efficiently in P301S‐htau mice than wild type (Wt) mice. We also found an increased level of myelin basic protein within the lesions, which however did not translate into increased remyelination due to higher susceptibility of P301S‐htau axons to demyelination‐induced degeneration compared to Wt axons. In vitro experiments confirmed higher differentiation capacity of OPCs from P301S‐htau mice compared with Wt mice‐derived OPCs. Because the OPCs from P301S‐htau mice do not ectopically express the transgene, and when isolated from newborn mice behave like Wt mice‐derived OPCs, we infer that their enhanced differentiation capacity must have been acquired through microenvironmental priming. Our data suggest the intriguing concept that damaged axons may signal to OPCs and promote their differentiation in the attempt at rescue by remyelination. GLIA 2016;64:457–471 PMID:26576485

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

    PubMed

    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.

  3. Sox2 in the dermal papilla niche controls hair growth by fine-tuning Bmp signaling in differentiating hair shaft progenitors

    PubMed Central

    Clavel, Carlos; Grisanti, Laura; Zemla, Roland; Rezza, Amelie; Barros, Rita; Sennett, Rachel; Mazloom, Amin; Chung, Chi-Yeh; Cai, Xiaoqiang; Cai, Chen-Leng; Pevny, Larysa; Nicolis, Silvia; Ma’ayan, Avi; Rendl, Michael

    2012-01-01

    SUMMARY How dermal papilla (DP) niche cells regulate hair follicle progenitors to control hair growth remains unclear. Using Tbx18Cre to target embryonic DP precursors, we ablate the transcription factor Sox2 early and efficiently, resulting in diminished hair shaft outgrowth. We find that DP niche expression of Sox2 controls the migration rate of differentiating hair shaft progenitors. Transcriptional profiling of Sox2 null DPs reveals increased Bmp6 and decreased Bmp inhibitor Sostdc1, a direct Sox2 transcriptional target. Subsequently, we identify upregulated Bmp signaling in knockout hair shaft progenitors and demonstrate that Bmps inhibit cell migration, an effect that can be attenuated by Sostdc1. A shorter and Sox2-negative hair type lacks Sostdc1 in the DP and shows reduced migration and increased Bmp activity of hair shaft progenitors. Collectively, our data identify Sox2 as a key regulator of hair growth that controls progenitor migration by fine-tuning Bmp-mediated mesenchymal-epithelial crosstalk. PMID:23153495

  4. Supervising Remote Humanoids Across Intermediate Time Delay

    NASA Technical Reports Server (NTRS)

    Hambuchen, Kimberly; Bluethmann, William; Goza, Michael; Ambrose, Robert; Rabe, Kenneth; Allan, Mark

    2006-01-01

    The President's Vision for Space Exploration, laid out in 2004, relies heavily upon robotic exploration of the lunar surface in early phases of the program. Prior to the arrival of astronauts on the lunar surface, these robots will be required to be controlled across space and time, posing a considerable challenge for traditional telepresence techniques. Because time delays will be measured in seconds, not minutes as is the case for Mars Exploration, uploading the plan for a day seems excessive. An approach for controlling humanoids under intermediate time delay is presented. This approach uses software running within a ground control cockpit to predict an immersed robot supervisor's motions which the remote humanoid autonomously executes. Initial results are presented.

  5. Intermediate dose of imatinib in combination with chemotherapy followed by allogeneic stem cell transplantation improves early outcome in paediatric Philadelphia chromosome-positive acute lymphoblastic leukaemia (ALL): results of the Spanish Cooperative Group SHOP studies ALL-94, ALL-99 and ALL-2005.

    PubMed

    Rives, Susana; Estella, Jesús; Gómez, Pedro; López-Duarte, Mónica; de Miguel, Purificación García; Verdeguer, Amparo; Moreno, Maria José; Vivanco, José Luis; Couselo, José Miguel; Fernández-Delgado, Rafael; Maldonado, Marisol; Tasso, María; López-Ibor, Blanca; Lendínez, Francisco; López-Almaraz, Ricardo; Uriz, Javier; Melo, Montserrat; Fernández-Teijeiro, Ana; Rodríguez, Isidoro; Badell, Isabel

    2011-09-01

    Philadelphia-chromosome acute lymphoblastic leukaemia (Ph+ ALL) is a subgroup of ALL with very high risk of treatment failure. We report here the results of the Sociedad Española de Hematología y Oncología Pediátricas (SEHOP/SHOP) in paediatric Ph+ ALL treated with intermediate-dose imatinib concurrent with intensive chemotherapy. The toxicities and outcome of these patients were compared with historical controls not receiving imatinib. Patients with Ph+ ALL aged 1-18years were enrolled in three consecutive ALL/SHOP trials (SHOP-94/SHOP-99/SHOP-2005). In the SHOP-2005 trial, imatinib (260mg/m(2) per day) was given on day-15 of induction. Allogeneic haematopoietic stem-cell transplantation (HSCT) from a matched related or unrelated donor was scheduled in first complete remission (CR1). Forty-three patients were evaluable (22 boys, median age 6·8years, range, 1·2-15). Sixteen received imatinib whereas 27 received similar chemotherapy without imatinib. Seventeen of 27 and 15 of 16 patients in the non-imatinib and imatinib cohort, respectively, underwent HSCT in CR1. With a median follow-up of 109 and 39months for the non-imatinib and imatinib cohorts, the 3-year event-free survival (EFS) was 29·6% and 78·7%, respectively (P=0·01). These results show that, compared to historical controls, intermediate dose of imatinib given concomitantly with chemotherapy and followed by allogeneic HSCT markedly improved early EFS in paediatric Ph+ ALL. © 2011 Blackwell Publishing Ltd.

  6. A cross-correlation search for intermediate-duration gravitational waves from GRB magnetars

    NASA Astrophysics Data System (ADS)

    Coyne, Robert

    2015-04-01

    Since the discovery of the afterglow in 1997, the progress made in our understanding of gamma-ray bursts (GRBs) has been spectacular. Yet a direct proof of GRB progenitors is still missing. In the last few years, evidence for a long-lived and sustained central engine in GRBs has mounted. This has called attention to the so-called millisecond-magnetar model, which proposes that a highly magnetized, rapidly-rotating neutron star may exist at the heart of some of these events. The advent of advanced gravitational wave detectors such as LIGO and Virgo may enable us to probe directly, for the first time, the nature of GRB progenitors and their byproducts. In this context, we describe a novel application of a generalized cross-correlation technique optimized for the detection of long-duration gravitational wave signals that may be associated with bar-like deformations of GRB magnetars. The detection of these signals would allow us to answer some of the most intriguing questions on the nature of GRB progenitors, and serve as a starting point for a new class of intermediate-duration gravitational wave searches.

  7. Inhibition of cyclooxygenase (COX)-2 affects endothelial progenitor cell proliferation

    SciTech Connect

    Colleselli, Daniela; Bijuklic, Klaudija; Mosheimer, Birgit A.

    2006-09-10

    Growing evidence indicates that inducible cyclooxygenase-2 (COX-2) is involved in the pathogenesis of inflammatory disorders and various types of cancer. Endothelial progenitor cells recruited from the bone marrow have been shown to be involved in the formation of new vessels in malignancies and discussed for being a key point in tumour progression and metastasis. However, until now, nothing is known about an interaction between COX and endothelial progenitor cells (EPC). Expression of COX-1 and COX-2 was detected by semiquantitative RT-PCR and Western blot. Proliferation kinetics, cell cycle distribution and rate of apoptosis were analysed by MTT test and FACS analysis.more » Further analyses revealed an implication of Akt phosphorylation and caspase-3 activation. Both COX-1 and COX-2 expression can be found in bone-marrow-derived endothelial progenitor cells in vitro. COX-2 inhibition leads to a significant reduction in proliferation of endothelial progenitor cells by an increase in apoptosis and cell cycle arrest. COX-2 inhibition leads further to an increased cleavage of caspase-3 protein and inversely to inhibition of Akt activation. Highly proliferating endothelial progenitor cells can be targeted by selective COX-2 inhibition in vitro. These results indicate that upcoming therapy strategies in cancer patients targeting COX-2 may be effective in inhibiting tumour vasculogenesis as well as angiogenic processes.« less

  8. Renal blood flow and oxygenation drive nephron progenitor differentiation.

    PubMed

    Rymer, Christopher; Paredes, Jose; Halt, Kimmo; Schaefer, Caitlin; Wiersch, John; Zhang, Guangfeng; Potoka, Douglas; Vainio, Seppo; Gittes, George K; Bates, Carlton M; Sims-Lucas, Sunder

    2014-08-01

    During kidney development, the vasculature develops via both angiogenesis (branching from major vessels) and vasculogenesis (de novo vessel formation). The formation and perfusion of renal blood vessels are vastly understudied. In the present study, we investigated the regulatory role of renal blood flow and O2 concentration on nephron progenitor differentiation during ontogeny. To elucidate the presence of blood flow, ultrasound-guided intracardiac microinjection was performed, and FITC-tagged tomato lectin was perfused through the embryo. Kidneys were costained for the vasculature, ureteric epithelium, nephron progenitors, and nephron structures. We also analyzed nephron differentiation in normoxia compared with hypoxia. At embryonic day 13.5 (E13.5), the major vascular branches were perfused; however, smaller-caliber peripheral vessels remained unperfused. By E15.5, peripheral vessels started to be perfused as well as glomeruli. While the interior kidney vessels were perfused, the peripheral vessels (nephrogenic zone) remained unperfused. Directly adjacent and internal to the nephrogenic zone, we found differentiated nephron structures surrounded and infiltrated by perfused vessels. Furthermore, we determined that at low O2 concentration, little nephron progenitor differentiation was observed; at higher O2 concentrations, more differentiation of the nephron progenitors was induced. The formation of the developing renal vessels occurs before the onset of blood flow. Furthermore, renal blood flow and oxygenation are critical for nephron progenitor differentiation. Copyright © 2014 the American Physiological Society.

  9. Direct Reprogramming of Mouse Fibroblasts into Functional Skeletal Muscle Progenitors.

    PubMed

    Bar-Nur, Ori; Gerli, Mattia F M; Di Stefano, Bruno; Almada, Albert E; Galvin, Amy; Coffey, Amy; Huebner, Aaron J; Feige, Peter; Verheul, Cassandra; Cheung, Priscilla; Payzin-Dogru, Duygu; Paisant, Sylvain; Anselmo, Anthony; Sadreyev, Ruslan I; Ott, Harald C; Tajbakhsh, Shahragim; Rudnicki, Michael A; Wagers, Amy J; Hochedlinger, Konrad

    2018-05-08

    Skeletal muscle harbors quiescent stem cells termed satellite cells and proliferative progenitors termed myoblasts, which play pivotal roles during muscle regeneration. However, current technology does not allow permanent capture of these cell populations in vitro. Here, we show that ectopic expression of the myogenic transcription factor MyoD, combined with exposure to small molecules, reprograms mouse fibroblasts into expandable induced myogenic progenitor cells (iMPCs). iMPCs express key skeletal muscle stem and progenitor cell markers including Pax7 and Myf5 and give rise to dystrophin-expressing myofibers upon transplantation in vivo. Notably, a subset of transplanted iMPCs maintain Pax7 expression and sustain serial regenerative responses. Similar to satellite cells, iMPCs originate from Pax7 + cells and require Pax7 itself for maintenance. Finally, we show that myogenic progenitor cell lines can be established from muscle tissue following small-molecule exposure alone. This study thus reports on a robust approach to derive expandable myogenic stem/progenitor-like cells from multiple cell types. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  10. Vascular wall progenitor cells in health and disease.

    PubMed

    Psaltis, Peter J; Simari, Robert D

    2015-04-10

    The vasculature plays an indispensible role in organ development and maintenance of tissue homeostasis, such that disturbances to it impact greatly on developmental and postnatal health. Although cell turnover in healthy blood vessels is low, it increases considerably under pathological conditions. The principle sources for this phenomenon have long been considered to be the recruitment of cells from the peripheral circulation and the re-entry of mature cells in the vessel wall back into cell cycle. However, recent discoveries have also uncovered the presence of a range of multipotent and lineage-restricted progenitor cells in the mural layers of postnatal blood vessels, possessing high proliferative capacity and potential to generate endothelial, smooth muscle, hematopoietic or mesenchymal cell progeny. In particular, the tunica adventitia has emerged as a progenitor-rich compartment with niche-like characteristics that support and regulate vascular wall progenitor cells. Preliminary data indicate the involvement of some of these vascular wall progenitor cells in vascular disease states, adding weight to the notion that the adventitia is integral to vascular wall pathogenesis, and raising potential implications for clinical therapies. This review discusses the current body of evidence for the existence of vascular wall progenitor cell subpopulations from development to adulthood and addresses the gains made and significant challenges that lie ahead in trying to accurately delineate their identities, origins, regulatory pathways, and relevance to normal vascular structure and function, as well as disease. © 2015 American Heart Association, Inc.

  11. Strategies to reverse endothelial progenitor cell dysfunction in diabetes.

    PubMed

    Petrelli, Alessandra; Di Fenza, Raffaele; Carvello, Michele; Gatti, Francesca; Secchi, Antonio; Fiorina, Paolo

    2012-01-01

    Bone-marrow-derived cells-mediated postnatal vasculogenesis has been reported as the main responsible for the regulation of vascular homeostasis in adults. Since their discovery, endothelial progenitor cells have been depicted as mediators of postnatal vasculogenesis for their peculiar phenotype (partially staminal and partially endothelial), their ability to differentiate in endothelial cell line and to be incorporated into the vessels wall during ischemia/damage. Diabetes mellitus, a condition characterized by cardiovascular disease, nephropathy, and micro- and macroangiopathy, showed a dysfunction of endothelial progenitor cells. Herein, we review the mechanisms involved in diabetes-related dysfunction of endothelial progenitor cells, highlighting how hyperglycemia affects the different steps of endothelial progenitor cells lifetime (i.e., bone marrow mobilization, trafficking into the bloodstream, differentiation in endothelial cells, and homing in damaged tissues/organs). Finally, we review preclinical and clinical strategies that aim to revert diabetes-induced dysfunction of endothelial progenitor cells as a means of finding new strategies to prevent diabetic complications.

  12. NFIX Regulates Neural Progenitor Cell Differentiation During Hippocampal Morphogenesis

    PubMed Central

    Heng, Yee Hsieh Evelyn; McLeay, Robert C.; Harvey, Tracey J.; Smith, Aaron G.; Barry, Guy; Cato, Kathleen; Plachez, Céline; Little, Erica; Mason, Sharon; Dixon, Chantelle; Gronostajski, Richard M.; Bailey, Timothy L.; Richards, Linda J.; Piper, Michael

    2014-01-01

    Neural progenitor cells have the ability to give rise to neurons and glia in the embryonic, postnatal and adult brain. During development, the program regulating whether these cells divide and self-renew or exit the cell cycle and differentiate is tightly controlled, and imbalances to the normal trajectory of this process can lead to severe functional consequences. However, our understanding of the molecular regulation of these fundamental events remains limited. Moreover, processes underpinning development of the postnatal neurogenic niches within the cortex remain poorly defined. Here, we demonstrate that Nuclear factor one X (NFIX) is expressed by neural progenitor cells within the embryonic hippocampus, and that progenitor cell differentiation is delayed within Nfix−/− mice. Moreover, we reveal that the morphology of the dentate gyrus in postnatal Nfix−/− mice is abnormal, with fewer subgranular zone neural progenitor cells being generated in the absence of this transcription factor. Mechanistically, we demonstrate that the progenitor cell maintenance factor Sry-related HMG box 9 (SOX9) is upregulated in the hippocampus of Nfix−/− mice and demonstrate that NFIX can repress Sox9 promoter-driven transcription. Collectively, our findings demonstrate that NFIX plays a central role in hippocampal morphogenesis, regulating the formation of neuronal and glial populations within this structure. PMID:23042739

  13. Mechanics of vimentin intermediate filaments

    NASA Technical Reports Server (NTRS)

    Wang, Ning; Stamenovic, Dimitrijie

    2002-01-01

    It is increasingly evident that the cytoskeleton of living cells plays important roles in mechanical and biological functions of the cells. Here we focus on the contribution of intermediate filaments (IFs) to the mechanical behaviors of living cells. Vimentin, a major structural component of IFs in many cell types, is shown to play an important role in vital mechanical and biological functions such as cell contractility, migration, stiffness, stiffening, and proliferation.

  14. Parathyroid Hormone Regulates the Distribution and Osteoclastogenic Potential of Hematopoietic Progenitors in the Bone Marrow

    PubMed Central

    Jacome-Galarza, Christian E; Lee, Sun-Kyeong; Lorenzo, Joseph A; Aguila, Hector Leonardo

    2011-01-01

    Parathyroid hormone (PTH) increases both the number of osteoclast in bone and the number of early hematopoietic stem cells (HSCs) in bone marrow. We previously characterized the phenotype of multiple populations of bone marrow cells with in vitro osteoclastogenic potential in mice. Here we examined whether intermittent administration of PTH influences these osteoclast progenitor (OCP) populations. C57BL/6 mice were treated with daily injections of bPTH(1–34) (80 μg/kg/day) for 7 or 14 days. We found that PTH caused a significant increase in the percentage of TN/CD115+CD117high and TN/CD115+CD117int cells ( p <.05) in bone marrow on day 7. In contrast, PTH decreased the absolute number of TN/CD115+CD117low cells by 39% on day 7 ( p <.05). On day 14, there was no effect of PTH on osteoclast progenitor distribution in vivo. However, PTH treatment for 7 and 14 days did increase receptor activator of NF-κB ligand (RANKL)– and macrophage colony-stimulating factor (M-CSF)–stimulated in vitro osteoclastogenesis and bone resorption in TN/CD115+ cells. In the periphery, 14 days of treatment increased the percentage and absolute numbers of HSCs (Lin−CD117+Sca-1+) in the spleen ( p <.05). These data correlated with an increase in the percent and absolute numbers of HSCs in bone marrow on day 14 ( p <.05). Interestingly, the effects on hematopoietic progenitors do not depend on osteoclast resorption activity. These results suggest that in vivo PTH treatment increased in vitro osteoclastogenesis and resorption without altering the number of osteoclast precursors. This implies that in vivo PTH induces sustained changes, possibly through an epigenetic mechanism, in the in vitro responsiveness of the cells to M-CSF and RANKL. PMID:21611963

  15. Cannabinoid receptor signaling in progenitor/stem cell proliferation and differentiation.

    PubMed

    Galve-Roperh, Ismael; Chiurchiù, Valerio; Díaz-Alonso, Javier; Bari, Monica; Guzmán, Manuel; Maccarrone, Mauro

    2013-10-01

    Cannabinoids, the active components of cannabis (Cannabis sativa) extracts, have attracted the attention of human civilizations for centuries, much earlier than the discovery and characterization of their substrate of action, the endocannabinoid system (ECS). The latter is an ensemble of endogenous lipids, their receptors [in particular type-1 (CB1) and type-2 (CB2) cannabinoid receptors] and metabolic enzymes. Cannabinoid signaling regulates cell proliferation, differentiation and survival, with different outcomes depending on the molecular targets and cellular context involved. Cannabinoid receptors are expressed and functional from the very early developmental stages, when they regulate embryonic and trophoblast stem cell survival and differentiation, and thus may affect the formation of manifold adult specialized tissues derived from the three different germ layers (ectoderm, mesoderm and endoderm). In the ectoderm-derived nervous system, both CB1 and CB2 receptors are present in neural progenitor/stem cells and control their self-renewal, proliferation and differentiation. CB1 and CB2 show opposite patterns of expression, the former increasing and the latter decreasing along neuronal differentiation. Recently, endocannabinoid (eCB) signaling has also been shown to regulate proliferation and differentiation of mesoderm-derived hematopoietic and mesenchymal stem cells, with a key role in determining the formation of several cell types in peripheral tissues, including blood cells, adipocytes, osteoblasts/osteoclasts and epithelial cells. Here, we will review these new findings, which unveil the involvement of eCB signaling in the regulation of progenitor/stem cell fate in the nervous system and in the periphery. The developmental regulation of cannabinoid receptor expression and cellular/subcellular localization, together with their role in progenitor/stem cell biology, may have important implications in human health and disease. Copyright © 2013 Elsevier Ltd

  16. Very late antigen-5 facilitates stromal progenitor cell differentiation into myofibroblast.

    PubMed

    Sen, Namita; Weingarten, Mark; Peter, Yakov

    2014-11-01

    Fibrotic disease is associated with abrogated stromal cell proliferation and activity. The precise identity of the cells that drive fibrosis remains obscure, in part because of a lack of information on their lineage development. To investigate the role of an early stromal progenitor cell (SPC) on the fibrotic process, we selected for, and monitored the stages of, fibroblast development from a previously reported free-floating anchorage-independent cell (AIC) progenitor population. Our findings demonstrate that organotypic pulmonary, cardiac, and renal fibroblast commitment follows a two-step process of attachment and remodeling in culture. Cell differentiation was confirmed by the inability of SPCs to revert to the free-floating state and functional mesenchymal stem/stromal cell (MSC) differentiation into osteoblast, adipocyte, chondrocyte, and fibroblastic lineages. The myofibroblastic phenotype was reflected by actin stress-fiber formation, α-smooth muscle production, and a greater than threefold increase in proliferative activity compared with that of the progenitors. SPC-derived pulmonary myofibroblasts demonstrated a more than 300-fold increase in fibronectin-1 (Fn1), collagen, type 1, α1, integrin α-5 (Itga5), and integrin β-1 (Itgb1) transcript levels. Very late antigen-5 (ITGA5/ITGB1) protein cluster formations were also prevalent on the differentiated cells. Normalized SPC-derived myofibroblast expression patterns reflected those of primary cultured lung myofibroblasts. Intratracheal implantation of pulmonary AICs into recipient mouse lungs resulted in donor cell FN1 production and evidence of epithelial derivation. SPC derivation into stromal tissue in vitro and in vivo and the observation that MSC and fibroblast lineages share a common ancestor could potentially lead to personalized antifibrotic therapies. ©AlphaMed Press.

  17. Progenitor Masses for Every Nearby Historic Core-Collapse Supernova

    NASA Astrophysics Data System (ADS)

    Williams, Benjamin

    2016-10-01

    Some of the most energetic explosions in the Universe are the core-collapse supernovae (CCSNe) that arise from the death of massive stars. They herald the birth of neutron stars and black holes, are prodigious emitters of neutrinos and gravitational waves, influence galactic hydrodynamics, trigger further star formation, and are a major site for nucleosynthesis, yet even the most basic elements of CCSN theory are poorly constrained by observations. Specifically, there are too few observations to constrain the progenitor mass distribution and fewer observations still to constrain the mapping between progenitor mass and explosion type (e.g. IIP IIL, IIb, Ib/c, etc.). Combining previous measurements with 9 proposed HST pointings covering 13 historic CCSNe, we plan to obtain progenitor mass measurements for all cataloged historic CCSNe within 8 Mpc, optimizing observational mass constraints for CCSN theory.

  18. Advances in hepatic stem/progenitor cell biology

    PubMed Central

    Verhulst, Stefaan; Best, Jan; van Grunsven, Leo A.; Dollé, Laurent

    2015-01-01

    The liver is famous for its strong regenerative capacity, employing different modes of regeneration according to type and extent of injury. Mature liver cells are able to proliferate in order to replace the damaged tissue allowing the recovery of the parenchymal function. In more severe scenarios hepatocytes are believed to arise also from a facultative liver progenitor cell compartment. In human, severe acute liver failure and liver cirrhosis are also both important clinical targets in which regeneration is impaired, where the role of this stem cell compartment seems more convincing. In animal models, the current state of ambiguity regarding the identity and role of liver progenitor cells in liver physiology dampens the enthusiasm for the potential use of these cells in regenerative medicine. The aim of this review is to give the basics of liver progenitor cell biology and discuss recent results vis-à-vis their identity and contribution to liver regeneration. PMID:26600740

  19. Ex-companions of Supernovae Progenitors

    NASA Astrophysics Data System (ADS)

    Xue, Zinchao

    Supernovae (SNe) are titanic explosions that end the life of stars. Fast expanding ejecta can create brightness that is comparable to the entire luminosity of the host galaxy for weeks. Eventually, the ejecta run into the ambient medium, creating the so-called supernova remnant (SNR) that fades away in 10,000 years. SNe come from two completely different mechanisms. The Type Ia SNe (SNIa) are powered by thermonuclear runaway when a white dwarf (WD) in a binary system accretes enough mass from a companion star. The Core Collapse supernovae (CCSNe) are massive stars that run out of fuel at the end of their lives and collapse. The basic scenario for SNIa is well established, but the type of the binary system containing the WD is the long-debated 'Type Ia Progenitor Problem'. (1) Searching for an ex-companion within a SNIa SNR would directly solve this problem as a binary system including two WDs should leave nothing behind, while others should leave a non-degenerate star near the site of the explosion. One of the results from this thesis is the determination of the explosion site of Tycho's SN (SN 1572). From this, I reject popular ex-companion candidates, e.g. Tycho star 'G' and a few other ones as they are too far away from the explosion site I determined. (2) Another attempt to address this problem is carried out by studying a rare kind of Type Ia SNe. Detailed photometric and spectral analysis indicates that ASASSN-14dc resembles features from the so-called SN Ia-CSM, in which, a SNIa explodes inside of dense Hydrogen-rich Circumstellar Material (CSM). The origin of the CSM brings serious questions to the traditional views of SNIa formation as none of them can comfortably explain the derived mass and distribution of the CSM. A recent realization of a particular model might solve a lot of puzzles around this rare class of SNIa. (3) CCSNe are known to be massive stars that rapidly evolve off the main sequence and soon explode. Nearly 80% of such stars have one or

  20. Progenitors of Core-Collapse Supernovae

    NASA Astrophysics Data System (ADS)

    Hirschi, R.; Arnett, D.; Cristini, A.; Georgy, C.; Meakin, C.; Walkington, I.

    2017-02-01

    Massive stars have a strong impact on their surroundings, in particular when they produce a core-collapse supernova at the end of their evolution. In these proceedings, we review the general evolution of massive stars and their properties at collapse as well as the transition between massive and intermediate-mass stars. We also summarise the effects of metallicity and rotation. We then discuss some of the major uncertainties in the modelling of massive stars, with a particular emphasis on the treatment of convection in 1D stellar evolution codes. Finally, we present new 3D hydrodynamic simulations of convection in carbon burning and list key points to take from 3D hydrodynamic studies for the development of new prescriptions for convective boundary mixing in 1D stellar evolution codes.

  1. Stem and progenitor cells: the premature desertion of rigorous definitions.

    PubMed

    Seaberg, Raewyn M; van der Kooy, Derek

    2003-03-01

    A current disturbing trend in stem cell biology is the abandonment of rigorous definitions of stem and progenitor cells in favor of more ambiguous, all-encompassing concepts. However, recent studies suggest that there are consistent, functional differences in the biology of these two cell types. Admittedly, it can be difficult to harmonize the in vivo and in vitro functional differences between stem and progenitor cells. Nonetheless, these distinctions between cell types should be emphasized rather than ignored, as they can be used to test specific hypotheses in neural stem cell biology.

  2. Regulation of Mammary Progenitor Cells by p53 and Parity

    DTIC Science & Technology

    2011-01-01

    quantitative PCR system (Stratagene). To knockdown Notch1 in TM40A cells, siRNA (s70698 and s70700) were purchased from Ambion. s70698 siRNA sense sequence: 5...hours after transfect ion and real-tim e quantitative P CR was used to confirm the knockdown efficiency. Results Label and chase progenitor cells...cells contained 0.8% o f DsRed positiv e (DsR +) progenitor cells (Fig. 1B). The mammosphere-forming capacity of DsR+ cells is 3.8-fold greater

  3. Endothelial progenitor cells in active rheumatoid arthritis: effects of tumour necrosis factor and glucocorticoid therapy

    PubMed Central

    Grisar, Johannes; Aletaha, Daniel; Steiner, Carl W; Kapral, Theresa; Steiner, Sabine; Säemann, Marcus; Schwarzinger, Ilse; Buranyi, Barbara; Steiner, Günter; Smolen, Josef S

    2007-01-01

    Objectives To study the effects of short‐term intermediate dose glucocorticoid (GC) therapy in patients with active rheumatoid arthritis (RA) on circulating endothelial progenitor cells (EPC), which are known to influence cardiovascular risk, and to elucidate mechanisms potentially responsible for the reduction of EPCs in patients with active RA. Methods EPCs were quantified in 29 patients with active RA by flow cytometry, colony forming unit (CFU) and circulating angiogenic cell (CAC) assays before and after 7 days of intermediate dose GC therapy. CFU from patients with RA and from healthy referents (HR) were cultured in vitro in the absence or presence of dexamethasone (Dex) and/or TNF. Results After 1 week of GC therapy, EPC increased from 0.026 (SD 0.003)% to 0.053 (SD 0.010)% (p<0.01), and from 12 (SD 4) to 27 (SD 7) CFU/well (p<0.02); CAC also increased from 7 (SD 2) to 29 (SD 8) cells/high power field (p<0.05). In parallel, disease activity decreased significantly after GC treatment. TNF serum levels also decreased from 36 (SD 10) to 14 (SD 6) pg/ml (p<0.0001). Addition of Dex to the RA CFU led to a significant increase of mean CFU counts, whereas addition of TNF induced a decrease of CFU. Conclusions Our data indicate that TNF may be at least partly responsible for the reduction of EPC seen in patients with RA. Intermediate doses of GCs for a short period of time, apart from reducing disease activity, significantly increase circulating EPC. PMID:17293363

  4. Potential early intermediates in anaerobic benzoate degradation by Rhodopseudomonas palustris.

    PubMed Central

    Gibson, K J; Gibson, J

    1992-01-01

    Alkali-treated extracts of Rhodopseudomonas palustris growing photosynthetically on benzoate were examined by gas chromatography/mass spectrometry for partially reduced benzoate derivatives. Two cyclic dienes, cyclohexa-2,5-diene-1-carboxylate and cyclohexa-1,4-diene-1-carboxylate, were detected. Either compound supported cell growth as effectively as benzoate. These results suggest that these cyclohexadienecarboxylates, probably as their coenzyme A esters, are the initial reduction products formed during anaerobic benzoate metabolism by R. palustris. PMID:1610191

  5. Pluripotent stem cell-derived radial glia-like cells as stable intermediate for efficient generation of human oligodendrocytes.

    PubMed

    Gorris, Raphaela; Fischer, Julia; Erwes, Kim Lina; Kesavan, Jaideep; Peterson, Daniel A; Alexander, Michael; Nöthen, Markus M; Peitz, Michael; Quandel, Tamara; Karus, Michael; Brüstle, Oliver

    2015-12-01

    Neural precursor cells (NPCs) derived from human pluripotent stem cells (hPSCs) represent an attractive tool for the in vitro generation of various neural cell types. However, the developmentally early NPCs emerging during hPSC differentiation typically show a strong propensity for neuronal differentiation, with more limited potential for generating astrocytes and, in particular, for generating oligodendrocytes. This phenomenon corresponds well to the consecutive and protracted generation of neurons and GLIA during normal human development. To obtain a more gliogenic NPC type, we combined growth factor-mediated expansion with pre-exposure to the differentiation-inducing agent retinoic acid and subsequent immunoisolation of CD133-positive cells. This protocol yields an adherent and self-renewing population of hindbrain/spinal cord radial glia (RG)-like neural precursor cells (RGL-NPCs) expressing typical neural stem cell markers such as nestin, ASCL1, SOX2, and PAX6 as well as RG markers BLBP, GLAST, vimentin, and GFAP. While RGL-NPCs maintain the ability for tripotential differentiation into neurons, astrocytes, and oligodendrocytes, they exhibit greatly enhanced propensity for oligodendrocyte generation. Under defined differentiation conditions promoting the expression of the major oligodendrocyte fate-determinants OLIG1/2, NKX6.2, NKX2.2, and SOX10, RGL-NPCs efficiently convert into NG2-positive oligodendroglial progenitor cells (OPCs) and are subsequently capable of in vivo myelination. Representing a stable intermediate between PSCs and OPCs, RGL-NPCs expedite the generation of PSC-derived oligodendrocytes with O4-, 4860-, and myelin basic protein (MBP)-positive cells that already appear within 7 weeks following growth factor withdrawal-induced differentiation. Thus, RGL-NPCs may serve as robust tool for time-efficient generation of human oligodendrocytes from embryonic and induced pluripotent stem cells. © 2015 Wiley Periodicals, Inc.

  6. Isolation and expansion of functionally-competent cardiac progenitor cells directly from heart biopsies

    PubMed Central

    Davis, Darryl R; Kizana, Eddy; Terrovitis, John; Barth, Andreas S.; Zhang, Yiqiang; Smith, Rachel Ruckdeschel; Miake, Junichiro; Marbán, Eduardo

    2010-01-01

    The adult heart contains reservoirs of progenitor cells that express embryonic and stem cell-related antigens. While these antigenically-purified cells are promising candidates for autologous cell therapy, clinical application is hampered by their limited abundance and tedious isolation methods. Methods that involve an intermediate cardiosphere-forming step have proven successful and are being tested clinically, but it is unclear whether the cardiosphere step is necessary. Accordingly, we investigated the molecular profile and functional benefit of cells that spontaneously emigrate from cardiac tissue in primary culture. Adult Wistar-Kyoto rat hearts were minced, digested and cultured as separate anatomical regions. Loosely-adherent cells that surround the plated tissue were harvested weekly for a total of five harvests. Genetic lineage tracing demonstrated that a small proportion of the direct outgrowth from cardiac samples originates from myocardial cells. This outgrowth contains sub-populations of cells expressing embryonic (SSEA-1) and stem cell-related antigens (c-Kit, abcg2) that varied with time in culture but not with the cardiac chamber of origin. This direct outgrowth, and its expanded progeny, underwent marked in vitro angiogenic/cardiogenic differentiation and cytokine secretion (IGF-1, VGEF). In vivo effects included long-term functional benefits as gauged by MRI following cell injection in a rat model of myocardial infarction. Outgrowth cells afforded equivalent functional benefits to cardiosphere-derived cells, which require more processing steps to manufacture. These results provide the basis for a simplified and efficient process to generate autologous cardiac progenitor cells (and mesenchymal supporting cells) to augment clinically-relevant approaches for myocardial repair. PMID:20211627

  7. Role of Intermediate Filaments in Vesicular Traffic.

    PubMed

    Margiotta, Azzurra; Bucci, Cecilia

    2016-04-25

    Intermediate filaments are an important component of the cellular cytoskeleton. The first established role attributed to intermediate filaments was the mechanical support to cells. However, it is now clear that intermediate filaments have many different roles affecting a variety of other biological functions, such as the organization of microtubules and microfilaments, the regulation of nuclear structure and activity, the control of cell cycle and the regulation of signal transduction pathways. Furthermore, a number of intermediate filament proteins have been involved in the acquisition of tumorigenic properties. Over the last years, a strong involvement of intermediate filament proteins in the regulation of several aspects of intracellular trafficking has strongly emerged. Here, we review the functions of intermediate filaments proteins focusing mainly on the recent knowledge gained from the discovery that intermediate filaments associate with key proteins of the vesicular membrane transport machinery. In particular, we analyze the current understanding of the contribution of intermediate filaments to the endocytic pathway.

  8. Gα13 Mediates a Signal That Is Essential for Proliferation and Survival of Thymocyte Progenitors

    PubMed Central

    McNeil Coffield, V.; Helms, Whitney S.; Jiang, Qi; Su, Lishan

    2004-01-01

    G protein signaling via the Gα12 family (Gα12 and Gα13) has not been well studied in T cells. To investigate whether Gα12 and Gα13 are involved in thymopoiesis, we expressed the regulator of G protein signaling domain of p115RhoGEF to inhibit Gα12 and Gα13 during thymopoiesis. Fetal thymus organ cultures seeded with p115ΔDH-expressing progenitor cells showed impaired thymopoiesis with a block at the CD4−CD8−CD44−CD25+ (DN3) stage. Using Gα13 or Gα12 minigenes, we demonstrated that Gα13, but not Gα12, is required for thymopoiesis. T progenitor cells expressing p115ΔDH showed reduced proliferation and increased cell death. T cell receptor stimulation of the fetal thymus organ cultures did not rescue the block. Overexpression of the antiapoptotic gene Bcl2 rescued the defect in DN3 cells and partially rescued T cell development. Therefore, Gα13-mediated signaling is necessary in early thymocyte proliferation and survival. PMID:15534370

  9. Identification of Regulatory Elements That Control PPARγ Expression in Adipocyte Progenitors

    PubMed Central

    Chou, Wen-Ling; Galmozzi, Andrea; Partida, David; Kwan, Kevin; Yeung, Hui; Su, Andrew I.; Saez, Enrique

    2013-01-01

    Adipose tissue renewal and obesity-driven expansion of fat cell number are dependent on proliferation and differentiation of adipose progenitors that reside in the vasculature that develops in coordination with adipose depots. The transcriptional events that regulate commitment of progenitors to the adipose lineage are poorly understood. Because expression of the nuclear receptor PPARγ defines the adipose lineage, isolation of elements that control PPARγ expression in adipose precursors may lead to discovery of transcriptional regulators of early adipocyte determination. Here, we describe the identification and validation in transgenic mice of 5 highly conserved non-coding sequences from the PPARγ locus that can drive expression of a reporter gene in a manner that recapitulates the tissue-specific pattern of PPARγ expression. Surprisingly, these 5 elements appear to control PPARγ expression in adipocyte precursors that are associated with the vasculature of adipose depots, but not in mature adipocytes. Characterization of these five PPARγ regulatory sequences may enable isolation of the transcription factors that bind these cis elements and provide insight into the molecular regulation of adipose tissue expansion in normal and pathological states. PMID:24009687

  10. Vascular pattern of the dentate gyrus is regulated by neural progenitors.

    PubMed

    Pombero, Ana; Garcia-Lopez, Raquel; Estirado, Alicia; Martinez, Salvador

    2018-05-01

    Neurogenesis is a vital process that begins during early embryonic development and continues until adulthood, though in the latter case, it is restricted to the subventricular zone and the subgranular zone of the dentate gyrus (DG). In particular, the DG's neurogenic properties are structurally and functionally unique, which may be related to its singular vascular pattern. Neurogenesis and angiogenesis share molecular signals and act synergistically, supporting the concept of a neurogenic niche as a functional unit between neural precursors cells and their environment, in which the blood vessels play an important role. Whereas it is well known that vascular development controls neural proliferation in the embryonary and in the adult brain, by releasing neurotrophic factors; the potential influence of neural cells on vascular components during angiogenesis is largely unknown. We have demonstrated that the reduction of neural progenitors leads to a significant impairment of vascular development. Since VEGF is a potential regulator in the neurogenesis-angiogenesis crosstalk, we were interested in assessing the possible role of this molecule in the hippocampal neurovascular development. Our results showed that VEGF is the molecule involved in the regulation of vascular development by neural progenitor cells in the DG.

  11. FGFR3 regulates brain size by controlling progenitor cell proliferation and apoptosis during embryonic development.

    PubMed

    Inglis-Broadgate, Suzanne L; Thomson, Rachel E; Pellicano, Francesca; Tartaglia, Michael A; Pontikis, Charlie C; Cooper, Jonathan D; Iwata, Tomoko

    2005-03-01

    Mice with the K644E kinase domain mutation in fibroblast growth factor receptor 3 (Fgfr3) (EIIa;Fgfr3(+/K644E)) exhibited a marked enlargement of the brain. The brain size was increased as early as E11.5, not secondary to the possible effect of Fgfr3 activity in the skeleton. Furthermore, the mutant brains showed a dramatic increase in cortical thickness, a phenotype opposite to that in FGF2 knockout mice. Despite this increased thickness, cortical layer formation was largely unaffected and no cortical folding was observed during embryonic days 11.5-18.5 (E11.5-E18.5). Measurement of cortical thickness revealed an increase of 38.1% in the EIIa;Fgfr3(+/K644E) mice at E14.5 and the advanced appearance of the cortical plate was frequently observed at this stage. Unbiased stereological analysis revealed that the volume of the ventricular zone (VZ) was increased by more than two fold in the EIIa;Fgfr3(+/K644E) mutants at E14.5. A relatively mild increase in progenitor cell proliferation and a profound decrease in developmental apoptosis during E11.5-E14.5 most likely accounts for the dramatic increase in total telecephalic cell number. Taken together, our data suggest a novel function of Fgfr3 in controlling the development of the cortex, by regulating proliferation and apoptosis of cortical progenitors.

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

    PubMed

    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.

  13. Histone deacetylases 1 and 2 regulate the transcriptional programs of nephron progenitors and renal vesicles.

    PubMed

    Liu, Hongbing; Chen, Shaowei; Yao, Xiao; Li, Yuwen; Chen, Chao-Hui; Liu, Jiao; Saifudeen, Zubaida; El-Dahr, Samir S

    2018-05-18

    Nephron progenitor cells (NPCs) are Six2-positive metanephric mesenchyme cells, which undergo self-renewal and differentiation to give rise to nephrons until the end of nephrogenesis. Histone deacetylases (HDACs) are a group of epigenetic regulators that control cell fate, but their role in balancing NPC renewal and differentiation is unknown. Here, we report that NPC-specific deletion of Hdac1 and Hdac2 genes in mice results in early postnatal lethality owing to renal hypodysplasia and loss of NPCs. HDAC1/2 interact with the NPC renewal regulators Six2, Osr1 and Sall1, and are co-bound along with Six2 on the Six2 enhancer. Although the mutant NPCs differentiate into renal vesicles (RVs), Hdac1/2 mutant kidneys lack nascent nephrons or mature glomeruli, a phenocopy of Lhx1 mutants. Transcriptional profiling and network analysis identified disrupted expression of Lhx1 and its downstream genes, Dll1 and Hnf1a/4a , as key mediators of the renal phenotype. Finally, although HDAC1/2-deficient NPCs and RVs overexpress hyperacetylated p53, Trp53 deletion failed to rescue the renal dysgenesis. We conclude that the epigenetic regulators HDAC1 and HDAC2 control nephrogenesis via interactions with the transcriptional programs of nephron progenitors and renal vesicles. © 2018. Published by The Company of Biologists Ltd.

  14. Progenitor cells are mobilized by acute psychological stress but not beta-adrenergic receptor agonist infusion

    PubMed Central

    Riddell, Natalie E.; Burns, Victoria E.; Wallace, Graham R.; Edwards, Kate M.; Drayson, Mark; Redwine, Laura S.; Hong, Suzi; Bui, Jack D.; Fischer, Johannes C.; Mills, Paul J.; Bosch, Jos A.

    2015-01-01

    Objectives Stimuli that activate the sympathetic nervous system, such as acute psychological stress, rapidly invoke a robust mobilization of lymphocytes into the circulation. Experimental animal studies suggest that bone marrow-derived progenitor cells (PCs) also mobilize in response to sympathetic stimulation. Here we tested the effects of acute psychological stress and brief pharmacological β-adrenergic (βAR) stimulation on peripheral PC numbers in humans. Methods In two studies, we investigated PC mobilization in response to an acute speech task (n=26) and βAR-agonist (isoproterenol) infusion (n=20). A subset of 8 participants also underwent the infusion protocol with concomitant administration of the βAR-antagonist propranolol. Flow cytometry was used to enumerate lymphocyte subsets, total progenitor cells, total haematopoietic stem cells (HSC), early HSC (multi-lineage potential), late HSC (lineage committed), and endothelial PCs (EPCs). Results Both psychological stress and βAR-agonist infusion caused the expected mobilization of total monocytes and lymphocytes and CD8+ T lymphocytes. Psychological stress also induced a modest, but significant, increase in total PCs, HSCs, and EPC numbers in peripheral blood. However, infusion of a βAR-agonist did not result in a significant change in circulating PCs. Conclusion PCs are rapidly mobilized by psychological stress via mechanisms independent of βAR-stimulation, although the findings do not exclude βAR-stimulation as a possible cofactor. Considering the clinical and physiological relevance, further research into the mechanisms involved in stress-induced PC mobilization seems warranted. PMID:25747743

  15. Cdx and T Brachyury Co-activate Growth Signaling in the Embryonic Axial Progenitor Niche.

    PubMed

    Amin, Shilu; Neijts, Roel; Simmini, Salvatore; van Rooijen, Carina; Tan, Sander C; Kester, Lennart; van Oudenaarden, Alexander; Creyghton, Menno P; Deschamps, Jacqueline

    2016-12-20

    In vertebrate embryos, anterior tissues are generated early, followed by the other axial structures that emerge sequentially from a posterior growth zone. The genetic network driving posterior axial elongation in mice, and its disturbance in mutants with posterior truncation, is not yet fully understood. Here, we show that the combined expression of Cdx2 and T Brachyury is essential to establish the core signature of posterior axial progenitors. Cdx2 and T Brachyury are required for extension of a similar trunk portion of the axis. Simultaneous loss of function of these two genes disrupts axial elongation to a much greater extent than each single mutation alone. We identify and validate common targets for Cdx2 and T Brachyury in vivo, including Wnt and Fgf pathway components active in the axial progenitor niche. Our data demonstrate that integration of the Cdx/Hox and T Brachyury transcriptional networks controls differential axial growth during vertebrate trunk elongation. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  16. The Impact of Juvenile Coxsackievirus Infection on Cardiac Progenitor Cells and Postnatal Heart Development

    PubMed Central

    Sin, Jon; Puccini, Jenna M.; Huang, Chengqun; Konstandin, Mathias H.; Gilbert, Paul E.; Sussman, Mark A.; Gottlieb, Roberta A.; Feuer, Ralph

    2014-01-01

    Coxsackievirus B (CVB) is an enterovirus that most commonly causes a self-limited febrile illness in infants, but cases of severe infection can manifest in acute myocarditis. Chronic consequences of mild CVB infection are unknown, though there is an epidemiologic association between early subclinical infections and late heart failure, raising the possibility of subtle damage leading to late-onset dysfunction, or chronic ongoing injury due to inflammatory reactions during latent infection. Here we describe a mouse model of juvenile infection with a subclinical dose of coxsackievirus B3 (CVB3) which showed no evident symptoms, either immediately following infection or in adult mice. However following physiological or pharmacologically-induced cardiac stress, juvenile-infected adult mice underwent cardiac hypertrophy and dilation indicative of progression to heart failure. Evaluation of the vasculature in the hearts of adult mice subjected to cardiac stress showed a compensatory increase in CD31+ blood vessel formation, although this effect was suppressed in juvenile-infected mice. Moreover, CVB3 efficiently infected juvenile c-kit+ cells, and cardiac progenitor cell numbers were reduced in the hearts of juvenile-infected adult mice. These results suggest that the exhausted cardiac progenitor cell pool following juvenile CVB3 infection may impair the heart's ability to increase capillary density to adapt to increased load. PMID:25079373

  17. Intermediate sanctions for healthcare organizations.

    PubMed

    Samuels, David G; Shoretz, Morris

    2002-09-01

    Intermediate sanctions legislation requires that tax-exempt providers take steps to ensure that their senior staff members are compensated at fair-market value. A first-time violation could subject an individual to an excise tax of 25 percent of the compensation amount deemed to be excess benefit. Failure to correct the violation could subject the individual to an excise tax of 200 percent of the excess benefit. Tax-exempt organizations may invoke a rebuttable presumption of reasonableness that compensation levels are appropriate. Tax-exempt providers should refer to IRS guidance regarding steps to ensuring compliance.

  18. Osteocalcin expression by circulating endothelial progenitor cells in patients with coronary atherosclerosis.

    PubMed

    Gössl, Mario; Mödder, Ulrike I; Atkinson, Elizabeth J; Lerman, Amir; Khosla, Sundeep

    2008-10-14

    This study was designed to test whether patients with coronary atherosclerosis have increases in circulating endothelial progenitor cells (EPCs) expressing an osteogenic phenotype. Increasing evidence indicates a link between bone and the vasculature, and bone marrow and circulating osteogenic cells have been identified by staining for the osteoblastic marker, osteocalcin (OCN). Endothelial progenitor cells contribute to vascular repair, but repair of vascular injury may result in calcification. Using cell surface markers (CD34, CD133, kinase insert domain receptor [KDR]) to identify EPCs, we examined whether patients with coronary atherosclerosis had increases in the percentage of EPCs expressing OCN. We studied 72 patients undergoing invasive coronary assessment: control patients (normal coronary arteries and no endothelial dysfunction, n = 21) versus 2 groups with coronary atherosclerosis-early coronary atherosclerosis (normal coronary arteries but with endothelial dysfunction, n = 22) and late coronary atherosclerosis (severe, multivessel coronary artery disease, n = 29). Peripheral blood mononuclear cells were analyzed using flow cytometry. Compared with control patients, patients with early or late coronary atherosclerosis had significant increases (approximately 2-fold) in the percentage of CD34+/KDR+ and CD34+/CD133+/KDR+ cells costaining for OCN. Even larger increases were noted in the early and late coronary atherosclerosis patients in the percentage of CD34+/CD133-/KDR+ cells costaining for OCN (5- and 2-fold, p < 0.001 and 0.05, respectively). A higher percentage of EPCs express OCN in patients with coronary atherosclerosis compared with subjects with normal endothelial function and no structural coronary artery disease. These findings have potential implications for the mechanisms of vascular calcification and for the development of novel markers for coronary atherosclerosis.

  19. Lineage mapping and characterization of the native progenitor population in cellular allograft.

    PubMed

    Neman, Josh; Duenas, Vincent; Kowolik, Claudia; Hambrecht, Amanda; Chen, Mike; Jandial, Rahul

    2013-02-01

    Osteocalcin; and (3) enzyme-linked immunosorbent assays (ELISA) for BMP-2, Osteocalcin, RANKL, Osteoprotegrin, and Osteocalcin. Clonal analysis of cells from cellular allograft was performed utilizing advance lentivirus lineage mapping techniques and massive parallel sequencing. Alizarin Red, Alcian Blue, and Oil red O staining assessed tripotential differentiation capacity. Serial trypsinization of allograft cellular bone matrix yielded approximately 1×105 cells per mL with viability greater than 90%. Cells expressed a panel of 84 MSC-associated genes in a pattern similar to but not identical to pure MSCs; specifically, 59 of 84 genes showed less than a 2.5-fold change in both cell types. Protein analysis showed that cellular allograft -derived cells maintained in nondifferentiation media expressed the early osteo-progenitor markers BMP-2, SMADs, and Runx2. Corresponding flow cytometry data for MSC markers revealed the presence of Stro-1 (49%), CD44 (99%), CD90 (42%), and CD146 (97%). Lineage mapping indicated that 62% of clones persisted and generated progeny through 10 passages, strongly suggesting the presence of bona fide stem cells. Passage 10 clones also exhibited tri-lineage differentiation capacity into osteogenic (Alizarin Red with H&E counterstain), chondrogenic (Alcian Blue), and adipogenic (Oil red O). Cells that did not proliferate through 10 passages presumably differentiated along an osteo-progenitor lineage. These data indicate that cellular allograft (Osteocel Plus) contains a heterogeneous population of cells with most cells demonstrating the capacity for extensive self-renewal and multipotential differentiation, which are hallmarks of stem cells. Whether stem cell-enriched allografts function comparably to autograft will require further studies, and their efficacy in facilitating arthrodesis will depend on randomized clinical studies. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Intermediality: Bridge to Critical Media Literacy.

    ERIC Educational Resources Information Center

    Pailliotet, Ann Watts; Semali, Ladislaus; Rodenberg, Rita K.; Giles, Jackie K.; Macaul, Sherry L.

    2000-01-01

    Defines "intermediality" as the ability to critically read and write with and across varied symbol systems. Relates it to critical media literacy. Offers rationales for teaching critical media literacy in general, and intermedial instruction in particular. Identifies seven guiding intermedial elements: theory, texts, processes, contexts,…

  1. Type Ia supernovae: explosions and progenitors

    NASA Astrophysics Data System (ADS)

    Kerzendorf, Wolfgang Eitel

    2011-08-01

    that they somehow need to acquire mass if they are to explode as SN Ia. Currently there are two major scenarios for this mass acquisition. In the favoured single degenerate scenario the white dwarf accretes matter from a companion star which is much younger in its evolutionary state. The less favoured double degenerate scenario sees the merger of two white dwarfs (with a total combined mass of more than 1.38 Msun). This thesis has tried to answer the question about the mass acquisition in two ways. First the single degenerate scenario predicts a surviving companion post-explosion. We undertook an observational campaign to find this companion in two ancient supernovae (SN 1572 and SN 1006). Secondly, we have extended an existing code to extract the elemental and energy yields of SNe Ia spectra by automating spectra fitting to specific SNe Ia. This type of analysis, in turn, help diagnose to which of the two major progenitor scenarios is right.

  2. Intermediate-Mass Black Holes

    NASA Astrophysics Data System (ADS)

    Miller, M. Coleman; Colbert, E. J. M.

    2004-01-01

    The mathematical simplicity of black holes, combined with their links to some of the most energetic events in the universe, means that black holes are key objects for fundamental physics and astrophysics. Until recently, it was generally believed that black holes in nature appear in two broad mass ranges: stellar-mass (M~3 20 M⊙), which are produced by the core collapse of massive stars, and supermassive (M~106 1010 M⊙), which are found in the centers of galaxies and are produced by a still uncertain combination of processes. In the last few years, however, evidence has accumulated for an intermediate-mass class of black holes, with M~102 104 M⊙. If such objects exist they have important implications for the dynamics of stellar clusters, the formation of supermassive black holes, and the production and detection of gravitational waves. We review the evidence for intermediate-mass black holes and discuss future observational and theoretical work that will help clarify numerous outstanding questions about these objects.

  3. Intermediate-Mass Black Holes

    NASA Astrophysics Data System (ADS)

    Coleman Miller, M.; Colbert, E. J. M.

    The mathematical simplicity of black holes, combined with their links to some of the most energetic events in the universe, means that black holes are key objects for fundamental physics and astrophysics. Until recently, it was generally believed that black holes in nature appear in two broad mass ranges: stellar-mass (M~3-20 M⊙), which are produced by the core collapse of massive stars, and supermassive (M~106-1010 M⊙), which are found in the centers of galaxies and are produced by a still uncertain combination of processes. In the last few years, however, evidence has accumulated for an intermediate-mass class of black holes, with M~102-104 M⊙. If such objects exist they have important implications for the dynamics of stellar clusters, the formation of supermassive black holes, and the production and detection of gravitational waves. We review the evidence for intermediate-mass black holes and discuss future observational and theoretical work that will help clarify numerous outstanding questions about these objects.

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

    PubMed Central

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

    2016-01-01

    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. PMID:27006501

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

    PubMed

    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.

  6. Hmga2 regulates self-renewal of retinal progenitors.

    PubMed

    Parameswaran, Sowmya; Xia, Xiaohuan; Hegde, Ganapati; Ahmad, Iqbal

    2014-11-01

    In vertebrate retina, histogenesis occurs over an extended period. To sustain the temporal generation of diverse cell types, retinal progenitor cells (RPCs) must self-renew. However, self-renewal and regulation of RPCs remain poorly understood. Here, we demonstrate that cell-extrinsic factors coordinate with the epigenetic regulator high-mobility group AT-hook 2 (Hmga2) to regulate self-renewal of late retinal progenitor cells (RPCs). We observed that a small subset of RPCs was capable of clonal propagation and retained multipotentiality of parents in the presence of endothelial cells (ECs), known self-renewal regulators in various stem cell niches. The self-renewing effects, also observed in vivo, involve multiple intercellular signaling pathways, engaging Hmga2. As progenitors exhaust during retinal development, expression of Hmga2 progressively decreases. Analyses of Hmga2-expression perturbation, in vitro and in vivo, revealed that Hmga2 functionally helps to mediate cell-extrinsic influences on late-retinal progenitor self-renewal. Our results provide a framework for integrating the diverse intercellular influences elicited by epigenetic regulators for self-renewal in a dynamic stem cell niche: the developing vertebrate retina. © 2014. Published by The Company of Biologists Ltd.

  7. Using Strong Gravitational Lensing to Identify Fossil Group Progenitors

    NASA Astrophysics Data System (ADS)

    Johnson, Lucas E.; Irwin, Jimmy A.; White, Raymond E., III; Wong, Ka-Wah; Maksym, W. Peter; Dupke, Renato A.; Miller, Eric D.; Carrasco, Eleazar R.

    2018-04-01

    Fossil galaxy systems are classically thought to be the end result of galaxy group/cluster evolution, as galaxies experiencing dynamical friction sink to the center of the group potential and merge into a single, giant elliptical that dominates the rest of the members in both mass and luminosity. Most fossil systems discovered lie within z < 0.2, which leads to the question, what were these systems’ progenitors? Such progenitors are expected to have imminent or ongoing major merging near the brightest group galaxy that, when concluded, will meet the fossil criteria within the look forward time. Since strong gravitational lensing preferentially selects groups merging along the line of sight, or systems with a high mass concentration like fossil systems, we searched the CASSOWARY survey of strong-lensing events with the goal of determining whether lensing systems have any predisposition to being fossil systems or progenitors. We find that ∼13% of lensing groups are identified as traditional fossils while only ∼3% of nonlensing control groups are. We also find that ∼23% of lensing systems are traditional fossil progenitors compared to ∼17% for the control sample. Our findings show that strong-lensing systems are more likely to be fossil/pre-fossil systems than comparable nonlensing systems. Cumulative galaxy luminosity functions of the lensing and nonlensing groups also indicate a possible, fundamental difference between strong-lensing and nonlensing systems’ galaxy populations, with lensing systems housing a greater number of bright galaxies even in the outskirts of groups.

  8. Intersections of lung progenitor cells, lung disease and lung cancer.

    PubMed

    Kim, Carla F

    2017-06-30

    The use of stem cell biology approaches to study adult lung progenitor cells and lung cancer has brought a variety of new techniques to the field of lung biology and has elucidated new pathways that may be therapeutic targets in lung cancer. Recent results have begun to identify the ways in which different cell populations interact to regulate progenitor activity, and this has implications for the interventions that are possible in cancer and in a variety of lung diseases. Today's better understanding of the mechanisms that regulate lung progenitor cell self-renewal and differentiation, including understanding how multiple epigenetic factors affect lung injury repair, holds the promise for future better treatments for lung cancer and for optimising the response to therapy in lung cancer. Working between platforms in sophisticated organoid culture techniques, genetically engineered mouse models of injury and cancer, and human cell lines and specimens, lung progenitor cell studies can begin with basic biology, progress to translational research and finally lead to the beginnings of clinical trials. Copyright ©ERS 2017.

  9. Mass ejection in failed supernovae: variation with stellar progenitor

    NASA Astrophysics Data System (ADS)

    Fernández, Rodrigo; Quataert, Eliot; Kashiyama, Kazumi; Coughlin, Eric R.

    2018-05-01

    We study the ejection of mass during stellar core-collapse when the stalled shock does not revive and a black hole forms. Neutrino emission during the protoneutron star phase causes a decrease in the gravitational mass of the core, resulting in an outward going sound pulse that steepens into a shock as it travels out through the star. We explore the properties of this mass ejection mechanism over a range of stellar progenitors using spherically symmetric, time-dependent hydrodynamic simulations that treat neutrino mass-loss parametrically and follow the shock propagation over the entire star. We find that all types of stellar progenitor can eject mass through this mechanism. The ejected mass is a decreasing function of the surface gravity of the star, ranging from several M⊙ for red supergiants to ˜0.1 M⊙ for blue supergiants and ˜10-3 M⊙ for Wolf-Rayet stars. We find that the final shock energy at the surface is a decreasing function of the core-compactness, and is ≲ 1047-1048 erg in all cases. In progenitors with a sufficiently large envelope, high core-compactness, or a combination of both, the sound pulse fails to unbind mass. Successful mass ejection is accompanied by significant fallback accretion that can last from hours to years. We predict the properties of shock breakout and thermal plateau emission produced by the ejection of the outer envelope of blue supergiant and Wolf-Rayet progenitors in otherwise failed supernovae.

  10. Characterization of Botulinum Progenitor Toxins by Mass Spectrometry

    DTIC Science & Technology

    2005-08-01

    and proteases by NTNH to HA-33 assistance in binding to and translocating progenitor toxin(s) through alimentary epithelial barriers (11, 12, 24...performed using peak list files generated by MassLynx (v3.5) and the following parameters: the National Center for Biotechnology Information

  11. Increased Cardiac Myocyte Progenitors in Failing Human Hearts

    PubMed Central

    Kubo, Hajime; Jaleel, Naser; Kumarapeli, Asangi; Berretta, Remus M.; Bratinov, George; Shan, Xiaoyin; Wang, Hongmei; Houser, Steven R.; Margulies, Kenneth B.

    2009-01-01

    Background Increasing evidence, derived mainly from animal models, supports the existence of endogenous cardiac renewal and repair mechanisms in adult mammalian hearts that could contribute to normal homeostasis and the responses to pathological insults. Methods and Results Translating these results, we isolated small c-kit+ cells from 36 of 37 human hearts using primary cell isolation techniques and magnetic cell sorting techniques. The abundance of these cardiac progenitor cells was increased nearly 4-fold in patients with heart failure requiring transplantation compared with nonfailing controls. Polychromatic flow cytometry of primary cell isolates (<30 μm) without antecedent c-kit enrichment confirmed the increased abundance of c-kit+ cells in failing hearts and demonstrated frequent coexpression of CD45 in these cells. Immunocytochemical characterization of freshly isolated, c-kit–enriched human cardiac progenitor cells confirmed frequent coexpression of c-kit and CD45. Primary cardiac progenitor cells formed new human cardiac myocytes at a relatively high frequency after coculture with neonatal rat ventricular myocytes. These contracting new cardiac myocytes exhibited an immature phenotype and frequent electric coupling with the rat myocytes that induced their myogenic differentiation. Conclusions Despite the increased abundance and cardiac myogenic capacity of cardiac progenitor cells in failing human hearts, the need to replace these organs via transplantation implies that adverse features of the local myocardial environment overwhelm endogenous cardiac repair capacity. Developing strategies to improve the success of endogenous cardiac regenerative processes may permit therapeutic myocardial repair without cell delivery per se. PMID:18645055

  12. Myogenic progenitors contribute to open but not closed fracture repair.

    PubMed

    Liu, Renjing; Birke, Oliver; Morse, Alyson; Peacock, Lauren; Mikulec, Kathy; Little, David G; Schindeler, Aaron

    2011-12-22

    Bone repair is dependent on the presence of osteocompetent progenitors that are able to differentiate and generate new bone. Muscle is found in close association with orthopaedic injury, however its capacity to make a cellular contribution to bone repair remains ambiguous. We hypothesized that myogenic cells of the MyoD-lineage are able to contribute to bone repair. We employed a MyoD-Cre+:Z/AP+ conditional reporter mouse in which all cells of the MyoD-lineage are permanently labeled with a human alkaline phosphatase (hAP) reporter. We tracked the contribution of MyoD-lineage cells in mouse models of tibial bone healing. In the absence of musculoskeletal trauma, MyoD-expressing cells are limited to skeletal muscle and the presence of reporter-positive cells in non-muscle tissues is negligible. In a closed tibial fracture model, there was no significant contribution of hAP+ cells to the healing callus. In contrast, open tibial fractures featuring periosteal stripping and muscle fenestration had up to 50% of hAP+ cells detected in the open fracture callus. At early stages of repair, many hAP+ cells exhibited a chondrocyte morphology, with lesser numbers of osteoblast-like hAP+ cells present at the later stages. Serial sections stained for hAP and type II and type I collagen showed that MyoD-lineage cells were surrounded by cartilaginous or bony matrix, suggestive of a functional role in the repair process. To exclude the prospect that osteoprogenitors spontaneously express MyoD during bone repair, we created a metaphyseal drill hole defect in the tibia. No hAP+ staining was observed in this model suggesting that the expression of MyoD is not a normal event for endogenous osteoprogenitors. These data document for the first time that muscle cells can play a significant secondary role in bone repair and this knowledge may lead to important translational applications in orthopaedic surgery. Please see related article: http://www.biomedcentral.com/1741-7015/9/136.

  13. The direct identification of core-collapse supernova progenitors.

    PubMed

    Van Dyk, Schuyler D

    2017-10-28

    To place core-collapse supernovae (SNe) in context with the evolution of massive stars, it is necessary to determine their stellar origins. I describe the direct identification of SN progenitors in existing pre-explosion images, particularly those obtained through serendipitous imaging of nearby galaxies by the Hubble Space Telescope I comment on specific cases representing the various core-collapse SN types. Establishing the astrometric coincidence of a SN with its putative progenitor is relatively straightforward. One merely needs a comparably high-resolution image of the SN itself and its stellar environment to perform this matching. The interpretation of these results, though, is far more complicated and fraught with larger uncertainties, including assumptions of the distance to and the extinction of the SN, as well as the metallicity of the SN environment. Furthermore, existing theoretical stellar evolutionary tracks exhibit significant variations one from the next. Nonetheless, it appears fairly certain that Type II-P (plateau) SNe arise from massive stars in the red supergiant phase. Many of the known cases are associated with subluminous Type II-P events. The progenitors of Type II-L (linear) SNe are less established. Among the stripped-envelope SNe, there are now a number of examples of cool, but not red, supergiants (presumably in binaries) as Type IIb progenitors. We appear now finally to have an identified progenitor of a Type Ib SN, but no known example yet for a Type Ic. The connection has been made between some Type IIn SNe and progenitor stars in a luminous blue variable phase, but that link is still thin, based on direct identifications. Finally, I also describe the need to revisit the SN site, long after the SN has faded, to confirm the progenitor identification through the star's disappearance and potentially to detect a putative binary companion that may have survived the explosion.This article is part of the themed issue 'Bridging the gap: from

  14. A population of relic intermediate-mass black holes in the halo of the Milky Way

    SciTech Connect

    Rashkov, Valery; Madau, Piero

    If 'seed' central black holes were common in the subgalactic building blocks that merged to form present-day massive galaxies, then relic intermediate-mass black holes (IMBHs) should be present in the Galactic bulge and halo. We use a particle tagging technique to dynamically populate the N-body Via Lactea II high-resolution simulation with black holes, and assess the size, properties, and detectability of the leftover population. The method assigns a black hole to the most tightly bound central particle of each subhalo at infall according to an extrapolation of the M {sub BH}-σ{sub *} relation, and self-consistently follows the accretion and disruptionmore » of Milky Way progenitor dwarfs and their holes in a cosmological 'live' host from high redshift to today. We show that, depending on the minimum stellar velocity dispersion, σ {sub m}, below which central black holes are assumed to be increasingly rare, as many as ∼2000 (σ {sub m} = 3 km s{sup –1}) or as few as ∼70 (σ {sub m} = 12 km s{sup –1}) IMBHs may be left wandering in the halo of the Milky Way today. The fraction of IMBHs forced from their hosts by gravitational recoil is ≲ 20%. We identify two main Galactic subpopulations, 'naked' IMBHs, whose host subhalos were totally destroyed after infall, and 'clothed' IMBHs residing in dark matter satellites that survived tidal stripping. Naked IMBHs typically constitute 40%-50% of the total and are more centrally concentrated. We show that, in the σ {sub m} = 12 km s{sup –1} scenario, the clusters of tightly bound stars that should accompany naked IMBHs would be fainter than m{sub V} = 16 mag, spatially resolvable, and have proper motions of 0.1-10 mas yr{sup –1}. Their detection may provide an observational tool to constrain the formation history of massive black holes in the early universe.« less

  15. [Coronary disease extension determines mobilization of endothelial progenitor cells and cytokines after a first myocardial infarction with ST elevation].

    PubMed

    Jiménez-Navarro, Manuel F; González, Francisco Jesús; Caballero-Borrego, Juan; Marchal, Juan Antonio; Rodríguez-Losada, Noela; Carrillo, Esmeralda; García-Pinilla, José Manuel; Hernández-García, José M; Pérez-González, Rita; Ramírez, Gemma; Aránega, Antonia; de Teresa Galván, Eduardo

    2011-12-01

    Multivessel coronary disease is still a postinfarction prognostic marker despite new forms of reperfusion, such as primary angioplasty. The aim of this study was to determine the time sequence of various sets of endothelial progenitor cells and angiogenic cytokines (vascular endothelial growth factor, hepatocyte growth factor) according to the degree of extension of the postinfarction coronary disease. We studied the release kinetics in 32 patients admitted for a first myocardial infarction with ST elevation, grouped according to whether they had single or multivessel disease, and 26 controls. The patients had a higher number of endothelial progenitor cells and angiogenic cytokines than the controls at all 3 measurements (admission, day 3, and day 7) of the following subsets: CD34, CD34+CD133+, CD34+KDR+, and CD34+CD133+KDR+CD45+(weak); this latter was higher on day 7. The levels of these cell subsets were all higher in the patients with single-vessel disease and at all 3 measurements. The vascular endothelial growth factor levels were raised during the first week and the hepatocyte growth factor showed an early peak on admission for infarction. No significant differences were seen in the cytokines according to coronary disease extension. Although the release kinetics of different subsets of endothelial progenitor cells in patients with a first acute myocardial infarction with ST elevation was similar in those with single vessel disease to those with multivessel disease, the number of circulating endothelial progenitor cells was greater in the patients with single vessel disease. The vascular endothelial growth factor levels were raised during the first postinfarction week and the hepatocyte growth factor were higher on admission. Copyright © 2011 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

  16. Observations of Core-Collapse Supernovae with Candidate Progenitor Identifications.

    NASA Astrophysics Data System (ADS)

    Elias-Rosa, Nancy; van Dyk, Schuyler D.

    2010-02-01

    Supernovae (SNe) have a profound effect on galaxies. They are clearly very important events deserving of intense study. Yet, even with nearly 4000 historical SNe, we know relatively little about the stars which give rise to these powerful explosions. The main limitation has been the lack of spatial resolution in pre-SN imaging data. However, since 1999 our team has been at the vanguard of directly identifying the progenitor stars of Core-Collapse (CC-) SNe in Hubble Space Telescope (HST) images. From this exciting new line of study, the emerging trend from a growing number of detections for Type II-Plateau SNe is that their progenitors appear to be relatively low mass (8-20 M_⊙) red supergiants, although more cases are needed. The nature of the progenitors of Type Ib/c SNe, a subset of which are associated with the amazing gamma-ray bursts, remains ambiguous. In HST Cycle 17 we are expecting to trigger our ToO observations using ACS/HRC (GO-11575) on 4 nearby (within 17 Mpc) CC-SNe, to determine the identities of the progenitors. It is conceivable that at least half of these will be discovered in the southern hemisphere. To fully characterize the progenitor star, we require detailed light curves and spectral evolution for the SNe, starting soon after discovery, to estimate the reddening to the SNe, characterize the overall luminosity and obtain a better understanding of the physics of the event. Therefore, to support the HST work, we are requesting up to 2 ToO triggers during semester 2010A, where we will monitor the SNe in BVRI with ANDICAM, and the 300 l/mm grating with the Goodman.

  17. [Stem and progenitor cells in biostructure of blood vessel walls].

    PubMed

    Korta, Krzysztof; Kupczyk, Piotr; Skóra, Jan; Pupka, Artur; Zejler, Paweł; Hołysz, Marcin; Gajda, Mariusz; Nowakowska, Beata; Barć, Piotr; Dorobisz, Andrzej T; Dawiskiba, Tomasz; Szyber, Piotr; Bar, Julia

    2013-09-18

    Development of vascular and hematopoietic systems during organogenesis occurs at the same time. During vasculogenesis, a small part of cells does not undergo complete differentiation but stays on this level, "anchored" in tissue structures described as stem cell niches. The presence of blood vessels within tissue stem cell niches is typical and led to identification of niches and ensures that they are functioning. The three-layer biostructure of vessel walls for artery and vein, tunica: intima, media and adventitia, for a long time was defined as a mechanical barrier between vessel light and the local tissue environment. Recent findings from vascular biology studies indicate that vessel walls are dynamic biostructures, which are equipped with stem and progenitor cells, described as vascular wall-resident stem cells/progenitor cells (VW-SC/PC). Distinct zones for vessel wall harbor heterogeneous subpopulations of VW-SC/PC, which are described as "subendothelial or vasculogenic zones". Recent evidence from in vitro and in vivo studies show that prenatal activity of stem and progenitor cells is not only limited to organogenesis but also exists in postnatal life, where it is responsible for vessel wall homeostasis, remodeling and regeneration. It is believed that VW-SC/PC could be engaged in progression of vascular disorders and development of neointima. We would like to summarize current knowledge about mesenchymal and progenitor stem cell phenotype with special attention to distribution and biological properties of VW-SC/PC in biostructures of intima, media and adventitia niches. It is postulated that in the near future, niches for VW-SC/PC could be a good source of stem and progenitor cells, especially in the context of vessel tissue bioengineering as a new alternative to traditional revascularization therapies.

  18. Hoxd11 specifies a program of metanephric kidney development within the intermediate mesoderm of the mouse embryo.

    PubMed

    Mugford, Joshua W; Sipilä, Petra; Kobayashi, Akio; Behringer, Richard R; McMahon, Andrew P

    2008-07-15

    The mammalian kidney consists of an array of tubules connected to a ductal system that collectively function to control water/salt balance and to remove waste from the organisms' circulatory system. During mammalian embryogenesis, three kidney structures form within the intermediate mesoderm. The two most anterior structures, the pronephros and the mesonephros, are transitory and largely non-functional, while the most posterior, the metanephros, persists as the adult kidney. We have explored the mechanisms underlying regional specific differentiation of the kidney forming mesoderm. Previous studies have shown a requirement for Hox11 paralogs (Hoxa11, Hoxc11 and Hoxd11) in metanephric development. Mice lacking all Hox11 activity fail to form metanephric kidney structures. We demonstrate that the Hox11 paralog expression is restricted in the intermediate mesoderm to the posterior, metanephric level. When Hoxd11 is ectopically activated in the anterior mesonephros, we observe a partial transformation to a metanephric program of development. Anterior Hoxd11(+) cells activate Six2, a transcription factor required for the maintenance of metanephric tubule progenitors. Additionally, Hoxd11(+) mesonephric tubules exhibit an altered morphology and activate several metanephric specific markers normally confined to distal portions of the functional nephron. Collectively, our data support a model where Hox11 paralogs specify a metanephric developmental program in responsive intermediate mesoderm. This program maintains tubule forming progenitors and instructs a metanephric specific pattern of nephron differentiation.

  19. Premyogenic progenitors derived from human pluripotent stem cells expand in floating culture and differentiate into transplantable myogenic progenitors.

    PubMed

    Sakai-Takemura, Fusako; Narita, Asako; Masuda, Satoru; Wakamatsu, Toshifumi; Watanabe, Nobuharu; Nishiyama, Takashi; Nogami, Ken'ichiro; Blanc, Matthias; Takeda, Shin'ichi; Miyagoe-Suzuki, Yuko

    2018-04-26

    Human induced pluripotent stem cells (hiPSCs) are a potential source for cell therapy of Duchenne muscular dystrophy. To reliably obtain skeletal muscle progenitors from hiPSCs, we treated hiPS cells with a Wnt activator, CHIR-99021 and a BMP receptor inhibitor, LDN-193189, and then induced skeletal muscle cells using a previously reported sphere-based culture. This protocol greatly improved sphere formation efficiency and stably induced the differentiation of myogenic cells from hiPS cells generated from both healthy donors and a patient with congenital myasthenic syndrome. hiPSC-derived myogenic progenitors were enriched in the CD57(-) CD108(-) CD271(+) ERBB3(+) cell fraction, and their differentiation was greatly promoted by TGF-β inhibitors. TGF-β inhibitors down-regulated the NFIX transcription factor, and NFIX short hairpin RNA (shRNA) improved the differentiation of iPS cell-derived myogenic progenitors. These results suggest that NFIX inhibited differentiation of myogenic progenitors. hiPSC-derived myogenic cells differentiated into myofibers in muscles of NSG-mdx 4Cv mice after direct transplantation. Our results indicate that our new muscle induction protocol is useful for cell therapy of muscular dystrophies.

  20. Conversion of immortal liver progenitor cells into pancreatic endocrine progenitor cells by persistent expression of Pdx-1.

    PubMed

    Jin, Cai-Xia; Li, Wen-Lin; Xu, Fang; Geng, Zhen H; He, Zhi-Ying; Su, Juan; Tao, Xin-Rong; Ding, Xiao-Yan; Wang, Xin; Hu, Yi-Ping

    2008-05-01

    The conversion of expandable liver progenitor cells into pancreatic beta cells would provide a renewable cell source for diabetes cell therapy. Previously, we reported the establishment of liver epithelial progenitor cells (LEPCs). In this work, LEPCs were modified into EGFP/Pdx-1 LEPCs, cells with stable expression of both Pdx-1 and EGFP. Unlike previous work, with persistent expression of Pdx-1, EGFP/Pdx-1 LEPCs acquired the phenotype of pancreatic endocrine progenitor cells rather than giving rise to insulin-producing cells directly. EGFP/Pdx-1 LEPCs proliferated vigorously and expressed the crucial transcription factors involved in beta cell development, including Ngn3, NeuroD, Nkx2.2, Nkx6.1, Pax4, Pax6, Isl1, MafA and endogenous Pdx-1, but did not secrete insulin. When cultured in high glucose/low serum medium supplemented with cytokines, EGFP/Pdx-1 LEPCs stopped proliferating and gave rise to functional beta cells without any evidence of exocrine or other islet cell lineage differentiation. When transplanted into diabetic SCID mice, EGFP/Pdx-1 LEPCs ameliorated hyperglycemia by secreting insulin in a glucose regulated manner. Considering the limited availability of beta cells, we propose that our experiments will provide a framework for utilizing the immortal liver progenitor cells as a renewable cell source for the generation of functional pancreatic beta cells.

  1. Identification, emergence and mobilization of circulating endothelial cells or progenitors in the embryo.

    PubMed

    Pardanaud, Luc; Eichmann, Anne

    2006-07-01

    Using quail-chick parabiosis and QH1 monoclonal antibody analysis, we have identified circulating endothelial cells and/or progenitors in the embryo. These cells were already present early in ontogeny, before the third embryonic day. Under normal conditions, they integrated into most tissues but remained scarce. When experimental angiogenic responses were induced by wounding or grafts onto the chorioallantoic membrane, circulating endothelial cells were rapidly mobilized and selectively integrated sites of neoangiogenesis. Their mobilization was not dependent on the presence of the bone marrow as it was effective before its differentiation. Surprisingly, mobilization was not effective during sprouting angiogenesis following VEGF treatment of chorioallantoic membrane. Thus, embryonic circulating endothelial cells were efficiently mobilized during the establishment of an initial vascular supply to ischemic tissues following wounding or grafting, but were not involved during classical sprouting angiogenesis.

  2. Heterogeneity and Fgf dependence of adult neural progenitors in the zebrafish telencephalon.

    PubMed

    Ganz, Julia; Kaslin, Jan; Hochmann, Sarah; Freudenreich, Dorian; Brand, Michael

    2010-08-15

    Adult telencephalic neurogenesis is a conserved trait of all vertebrates studied. It has been investigated in detail in rodents, but very little is known about the composition of neurogenic niches and the cellular nature of progenitors in nonmammalian vertebrates. To understand the components of the progenitor zones in the adult zebrafish telencephalon and the link between glial characteristics and progenitor state, we examined whether canonical glial markers are colocalized with proliferation markers. In the adult zebrafish telencephalon, we identify heterogeneous progenitors that reside in two distinct glial domains. We find that the glial composition of the progenitor zone is linked to its proliferative behavior. Analyzing both fast-cycling proliferating cells as well as slowly cycling progenitors, we find four distinct progenitor types characterized by differential expression of glial markers. Importantly, a significant proportion of progenitors do not display typical radial glia characteristics. By blocking or activating Fgf signaling by misexpression of a dominant negative Fgf-receptor 1 or Fgf8a, respectively, we find that ventral and dorsal progenitors in the telencephalon also differ in their requirement for Fgf signaling. Together with data on the expression of Fgf signaling components in the ventricular zone of the telencephalon, this suggests that Fgf signaling directly regulates proliferation of specific subsets of adult telencephalic progenitors in vivo. Taken together our results show that adult neural progenitor cells are heterogeneous with their respect to distribution into two distinct glial domains and their dependence upon Fgf signaling as a proliferative cue in the zebrafish telencephalon.

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

    PubMed Central

    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

    2016-01-01

    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. PMID:27827819

  4. β-Catenin Signaling Biases Multipotent Lingual Epithelial Progenitors to Differentiate and Acquire Specific Taste Cell Fates

    PubMed Central

    Gaillard, Dany; Xu, Mingang; Liu, Fei; Millar, Sarah E.; Barlow, Linda A.

    2015-01-01

    Continuous taste bud cell renewal is essential to maintain taste function in adults; however, the molecular mechanisms that regulate taste cell turnover are unknown. Using inducible Cre-lox technology, we show that activation of β-catenin signaling in multipotent lingual epithelial progenitors outside of taste buds diverts daughter cells from a general epithelial to a taste bud fate. Moreover, while taste buds comprise 3 morphological types, β-catenin activation drives overproduction of primarily glial-like Type I taste cells in both anterior fungiform (FF) and posterior circumvallate (CV) taste buds, with a small increase in Type II receptor cells for sweet, bitter and umami, but does not alter Type III sour detector cells. Beta-catenin activation in post-mitotic taste bud precursors likewise regulates cell differentiation; forced activation of β-catenin in these Shh+ cells promotes Type I cell fate in both FF and CV taste buds, but likely does so non-cell autonomously. Our data are consistent with a model where β-catenin signaling levels within lingual epithelial progenitors dictate cell fate prior to or during entry of new cells into taste buds; high signaling induces Type I cells, intermediate levels drive Type II cell differentiation, while low levels may drive differentiation of Type III cells. PMID:26020789

  5. β-Catenin Signaling Biases Multipotent Lingual Epithelial Progenitors to Differentiate and Acquire Specific Taste Cell Fates.

    PubMed

    Gaillard, Dany; Xu, Mingang; Liu, Fei; Millar, Sarah E; Barlow, Linda A

    2015-05-01

    Continuous taste bud cell renewal is essential to maintain taste function in adults; however, the molecular mechanisms that regulate taste cell turnover are unknown. Using inducible Cre-lox technology, we show that activation of β-catenin signaling in multipotent lingual epithelial progenitors outside of taste buds diverts daughter cells from a general epithelial to a taste bud fate. Moreover, while taste buds comprise 3 morphological types, β-catenin activation drives overproduction of primarily glial-like Type I taste cells in both anterior fungiform (FF) and posterior circumvallate (CV) taste buds, with a small increase in Type II receptor cells for sweet, bitter and umami, but does not alter Type III sour detector cells. Beta-catenin activation in post-mitotic taste bud precursors likewise regulates cell differentiation; forced activation of β-catenin in these Shh+ cells promotes Type I cell fate in both FF and CV taste buds, but likely does so non-cell autonomously. Our data are consistent with a model where β-catenin signaling levels within lingual epithelial progenitors dictate cell fate prior to or during entry of new cells into taste buds; high signaling induces Type I cells, intermediate levels drive Type II cell differentiation, while low levels may drive differentiation of Type III cells.

  6. Deletion of Pten Expands Lung Epithelial Progenitor Pools and Confers Resistance to Airway Injury

    PubMed Central

    Tiozzo, Caterina; De Langhe, Stijn; Yu, Mingke; Londhe, Vedang A.; Carraro, Gianni; Li, Min; Li, Changgong; Xing, Yiming; Anderson, Stewart; Borok, Zea; Bellusci, Saverio; Minoo, Parviz

    2009-01-01

    Rationale: Pten is a tumor-suppressor gene involved in stem cell homeostasis and tumorigenesis. In mouse, Pten expression is ubiquitous and begins as early as 7 days of gestation. Pten−/− mouse embryos die early during gestation indicating a critical role for Pten in embryonic development. Objectives: To test the role of Pten in lung development and injury. Methods: We conditionally deleted Pten throughout the lung epithelium by crossing Ptenflox/flox with Nkx2.1-cre driver mice. The resulting PtenNkx2.1-cre mutants were analyzed for lung defects and response to injury. Measurements and Main Results: PtenNkx2.1-cre embryonic lungs showed airway epithelial hyperplasia with no branching abnormalities. In adult mice, PtenNkx2.1-cre lungs exhibit increased progenitor cell pools composed of basal cells in the trachea, CGRP/CC10 double-positive neuroendocrine cells in the bronchi, and CC10/SPC double-positive cells at the bronchioalveolar duct junctions. Pten deletion affected differentiation of various lung epithelial cell lineages, with a decreased number of terminally differentiated cells. Over time, PtenNxk2.1-cre epithelial cells residing in the bronchioalveolar duct junctions underwent proliferation and formed uniform masses, supporting the concept that the cells residing in this distal niche may also be the source of procarcinogenic stem cells. Finally, increased progenitor cells in all the lung compartments conferred an overall selective advantage to naphthalene injury compared with wild-type control mice. Conclusions: Pten has a pivotal role in lung stem cell homeostasis, cell differentiation, and consequently resistance to lung injury. PMID:19574443

  7. Parity induces differentiation and reduces Wnt/Notch signaling ratio and proliferation potential of basal stem/progenitor cells isolated from mouse mammary epithelium

    PubMed Central

    2013-01-01

    Introduction Early pregnancy has a strong protective effect against breast cancer in humans and rodents, but the underlying mechanism is unknown. Because breast cancers are thought to arise from specific cell subpopulations of mammary epithelia, we studied the effect of parity on the transcriptome and the differentiation/proliferation potential of specific luminal and basal mammary cells in mice. Methods Mammary epithelial cell subpopulations (luminal Sca1-, luminal Sca1+, basal stem/progenitor, and basal myoepithelial cells) were isolated by flow cytometry from parous and age-matched virgin mice and examined by using a combination of unbiased genomics, bioinformatics, in vitro colony formation, and in vivo limiting dilution transplantation assays. Specific findings were further investigated with immunohistochemistry in entire glands of parous and age-matched virgin mice. Results Transcriptome analysis revealed an upregulation of differentiation genes and a marked decrease in the Wnt/Notch signaling ratio in basal stem/progenitor cells of parous mice. Separate bioinformatics analyses showed reduced activity for the canonical Wnt transcription factor LEF1/TCF7 and increased activity for the Wnt repressor TCF3. This finding was specific for basal stem/progenitor cells and was associated with downregulation of potentially carcinogenic pathways and a reduction in the proliferation potential of this cell subpopulation in vitro and in vivo. As a possible mechanism for decreased Wnt signaling in basal stem/progenitor cells, we found a more than threefold reduction in the expression of the secreted Wnt ligand Wnt4 in total mammary cells from parous mice, which corresponded to a similar decrease in the proportion of Wnt4-secreting and estrogen/progesterone receptor-positive cells. Because recombinant Wnt4 rescued the proliferation defect of basal stem/progenitor cells in vitro, reduced Wnt4 secretion appears to be causally related to parity-induced alterations of basal stem/progenitor

  8. Pax6 Exerts Regional Control of Cortical Progenitor Proliferation via Direct Repression of Cdk6 and Hypophosphorylation of pRb

    PubMed Central

    Mi, Da; Carr, Catherine B.; Georgala, Petrina A.; Huang, Yu-Ting; Manuel, Martine N.; Jeanes, Emily; Niisato, Emi; Sansom, Stephen N.; Livesey, Frederick J.; Theil, Thomas; Hasenpusch-Theil, Kerstin; Simpson, T. Ian; Mason, John O.; Price, David J.

    2013-01-01

    Summary The mechanisms by which early spatiotemporal expression patterns of transcription factors such as Pax6 regulate cortical progenitors in a region-specific manner are poorly understood. Pax6 is expressed in a gradient across the developing cortex and is essential for normal corticogenesis. We found that constitutive or conditional loss of Pax6 increases cortical progenitor proliferation by amounts that vary regionally with normal Pax6 levels. We compared the gene expression profiles of equivalent Pax6-expressing progenitors isolated from Pax6+/+ and Pax6−/− cortices and identified many negatively regulated cell-cycle genes, including Cyclins and Cdks. Biochemical assays indicated that Pax6 directly represses Cdk6 expression. Cyclin/Cdk repression inhibits retinoblastoma protein (pRb) phosphorylation, thereby limiting the transcription of genes that directly promote the mechanics of the cell cycle, and we found that Pax6 inhibits pRb phosphorylation and represses genes involved in DNA replication. Our results indicate that Pax6’s modulation of cortical progenitor cell cycles is regional and direct. PMID:23622063

  9. Identification of a progenitor cell population destined to form fracture fibrocartilage callus in Dickkopf-related protein 3-green fluorescent protein reporter mice.

    PubMed

    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.

  10. Fail-Safe Therapy by Gamma-Ray Irradiation Against Tumor Formation by Human-Induced Pluripotent Stem Cell-Derived Neural Progenitors.

    PubMed

    Katsukawa, Mitsuko; Nakajima, Yusuke; Fukumoto, Akiko; Doi, Daisuke; Takahashi, Jun

    2016-06-01

    Cell replacement therapy holds great promise for Parkinson's disease (PD), but residual undifferentiated cells and immature neural progenitors in the therapy may cause tumor formation. Although cell sorting could effectively exclude these proliferative cells, from the viewpoint of clinical application, there exists no adequate coping strategy in the case of their contamination. In this study, we analyzed a component of proliferative cells in the grafts of human-induced pluripotent stem cell-derived neural progenitors and investigated the effect of radiation therapy on tumor formation. In our differentiating protocol, analyses of neural progenitors (day 19) revealed that the proliferating cells expressed early neural markers (SOX1, PAX6) or a dopaminergic neuron progenitor marker (FOXA2). When grafted into the rat striatum, these immature neurons gradually became postmitotic in the brain, and the rosette structures disappeared at 14 weeks. However, at 4-8 weeks, the SOX1(+)PAX6(+) cells formed rosette structures in the grafts, suggesting their tumorigenic potential. Therefore, to develop a fail-safe therapy against tumor formation, we investigated the effect of radiation therapy. At 4 weeks posttransplantation, when KI67(+) cells comprised the highest ratio, radiation therapy with (137)Cs Gammacell Exactor for tumor-bearing immunodeficient rats showed a significant decrease in graft volume and percentage of SOX1(+)KI67(+) cells in the graft, thus demonstrating the preventive effect of gamma-ray irradiation against tumorigenicity. These results give us critical criteria for the safety of future cell replacement therapy for PD.

  11. Single progenitor model for GW150914 and GW170104

    NASA Astrophysics Data System (ADS)

    D'Orazio, Daniel J.; Loeb, Abraham

    2018-04-01

    The merger of stellar-mass black holes (BHs) is not expected to generate detectable electromagnetic (EM) emission. However, the gravitational wave (GW) events GW150914 and GW170104, detected by the Laser Interferometer Gravitational Wave Observatory to be the result of merging, ˜60 M⊙ binary black holes (BBHs), each have claimed coincident gamma-ray emission. Motivated by the intriguing possibility of an EM counterpart to BBH mergers, we construct a model that can reproduce the observed EM and GW signals for GW150914- and GW170104-like events, from a single-star progenitor. Following Loeb [Astrophys. J. Lett. 819, L21 (2016), 10.3847/2041-8205/819/2/L21], we envision a massive, rapidly rotating star within which a rotating-bar instability fractures the core into two overdensities that fragment into clumps which merge to form BHs in a tight binary with arbitrary spin-orbit alignment. Once formed, the BBH inspirals due to gas and gravitational-wave drag until tidal forces trigger strong feeding of the BHs with the surrounding stellar-density gas about 10 sec before merger. The resulting giga-Eddington accretion peak launches a jet that breaks out of the progenitor star and drives a powerful outflow that clears the gas from the orbit of the binary within 1 sec, preserving the vacuum GW waveform in the Laser Interferometer Gravitational Wave Observatory band. The single-progenitor scenario predicts the existence of variability of the gamma-ray burst, modulated at the ˜0.2 sec chirping period of the BBH due to relativistic Doppler boost. The jet breakout should be accompanied by a low-luminosity supernova. Finally, because the BBHs of the single-progenitor model do not exist at large separations, they will not be detectable in the low-frequency gravitational-wave band of the Laser Interferometer Space Antenna. Hence, the single-progenitor BBHs will be unambiguously discernible from BBHs formed through alternate, double-progenitor evolution scenarios.

  12. Search for Type Ia supernova progenitors in open star clusters

    NASA Astrophysics Data System (ADS)

    Chakraborty, Subho

    2013-12-01

    Though Type Ia supernovae (henceforth SNae) are a primary tool in refining our understanding of cosmology and dark energy, controversies still abound regarding what the progenitors of these SNae are. The two main classes of possible Type Ia SN progenitors are: (1) the single-degenerate model, where a white dwarf (the remnant of a Sun-like star that has completed its life cycle) gravitationally accretes material from a close companion star, and (2) the double-degenerate model, involving the merger of two white dwarfs. In either case, the resulting SN explosion looks the same superficially. But some of the details of the SNae, perhaps including details critical to understanding dark energy, may depend sensitively on what the progenitors are. The goal of this thesis was to search for radial velocity variations in two candidate double degenerate systems. Firstly, I determined if either of these systems were bona fide double degenerates. I used the well-tested method of searching for radial velocity variations due to orbital motion as determined by changing Doppler shifts in their optical spectra. These data were obtained from time-series spectra of both candidate systems over several hours at the world's largest ground based optical telescope, the Keck Observatory in Hawaii. Secondly, I tested whether each confirmed binary system is of sufficient mass and sufficiently short orbital period to be progenitors of a future Type Ia SN. Binary white dwarfs that will merge to form Type IaSNae over a Hubble time have orbital periods less than six hours, which are easily detectable with these data. Type Ia SN progenitors must also have a mass near or above the Chandrasekhar limit of ~1.44 solar masses; the total mass of these systems can also be determined from our data. If one or both of these candidate systems had met both these criteria, the white dwarfs would have been the first definitive examples of the double degenerate class of Type Ia progenitors. This result, which we

  13. Protein vivisection reveals elusive intermediates in folding

    PubMed Central

    Zheng, Zhongzhou; Sosnick, Tobin R.

    2010-01-01

    Although most folding intermediates escape detection, their characterization is crucial to the elucidation of folding mechanisms. Here we outline a powerful strategy to populate partially unfolded intermediates: A buried aliphatic residue is substituted with a charged residue (e.g., Leu→Glu−) to destabilize and unfold a specific region of the protein. We apply this strategy to Ubiquitin, reversibly trapping a folding intermediate in which the β5 strand is unfolded. The intermediate refolds to a native-like structure upon charge neutralization under mildly acidic conditions. Characterization of the trapped intermediate using NMR and hydrogen exchange methods identifies a second folding intermediate and reveals the order and free energies of the two major folding events on the native side of the rate-limiting step. This general strategy may be combined with other methods and have broad applications in the study of protein folding and other reactions that require trapping of high energy states. PMID:20144618

  14. Electron microscopic analysis of rotavirus assembly-replication intermediates

    SciTech Connect

    Boudreaux, Crystal E.; Kelly, Deborah F.; McDonald, Sarah M., E-mail: mcdonaldsa@vtc.vt.edu

    2015-03-15

    Rotaviruses (RVs) replicate their segmented, double-stranded RNA genomes in tandem with early virion assembly. In this study, we sought to gain insight into the ultrastructure of RV assembly-replication intermediates (RIs) using transmission electron microscopy (EM). Specifically, we examined a replicase-competent, subcellular fraction that contains all known RV RIs. Three never-before-seen complexes were visualized in this fraction. Using in vitro reconstitution, we showed that ~15-nm doughnut-shaped proteins in strings were nonstructural protein 2 (NSP2) bound to viral RNA transcripts. Moreover, using immunoaffinity-capture EM, we revealed that ~20-nm pebble-shaped complexes contain the viral RNA polymerase (VP1) and RNA capping enzyme (VP3). Finally,more » using a gel purification method, we demonstrated that ~30–70-nm electron-dense, particle-shaped complexes represent replicase-competent core RIs, containing VP1, VP3, and NSP2 as well as capsid proteins VP2 and VP6. The results of this study raise new questions about the interactions among viral proteins and RNA during the concerted assembly–replicase process. - Highlights: • Rotaviruses replicate their genomes in tandem with early virion assembly. • Little is known about rotavirus assembly-replication intermediates. • Assembly-replication intermediates were imaged using electron microscopy.« less

  15. Intermediates and the folding of proteins L and G

    SciTech Connect

    Brown, Scott; Head-Gordon, Teresa

    We use a minimalist protein model, in combination with a sequence design strategy, to determine differences in primary structure for proteins L and G that are responsible for the two proteins folding through distinctly different folding mechanisms. We find that the folding of proteins L and G are consistent with a nucleation-condensation mechanism, each of which is described as helix-assisted {beta}-1 and {beta}-2 hairpin formation, respectively. We determine that the model for protein G exhibits an early intermediate that precedes the rate-limiting barrier of folding and which draws together misaligned secondary structure elements that are stabilized by hydrophobic core contactsmore » involving the third {beta}-strand, and presages the later transition state in which the correct strand alignment of these same secondary structure elements is restored. Finally the validity of the targeted intermediate ensemble for protein G was analyzed by fitting the kinetic data to a two-step first order reversible reaction, proving that protein G folding involves an on-pathway early intermediate, and should be populated and therefore observable by experiment.« less

  16. Intermediates and the folding of proteins L and G

    PubMed Central

    Brown, Scott; Head-Gordon, Teresa

    2004-01-01

    We use a minimalist protein model, in combination with a sequence design strategy, to determine differences in primary structure for proteins L and G, which are responsible for the two proteins folding through distinctly different folding mechanisms. We find that the folding of proteins L and G are consistent with a nucleation-condensation mechanism, each of which is described as helix-assisted β-1 and β-2 hairpin formation, respectively. We determine that the model for protein G exhibits an early intermediate that precedes the rate-limiting barrier of folding, and which draws together misaligned secondary structure elements that are stabilized by hydrophobic core contacts involving the third β-strand, and presages the later transition state in which the correct strand alignment of these same secondary structure elements is restored. Finally, the validity of the targeted intermediate ensemble for protein G was analyzed by fitting the kinetic data to a two-step first-order reversible reaction, proving that protein G folding involves an on-pathway early intermediate, and should be populated and therefore observable by experiment. PMID:15044729

  17. Experiments in intermediate energy physics

    SciTech Connect

    Dehnhard, D.

    Research in experimental nuclear physics was done from 1979 to 2002 primarily at intermediate energy facilities that provide pion, proton, and kaon beams. Particularly successful has been the work at the Los Alamos Meson Physics Facility (LAMPF) on unraveling the neutron and proton contributions to nuclear ground state and transition densities. This work was done on a wide variety of nuclei and with great detail on the carbon, oxygen, and helium isotopes. Some of the investigations involved the use of polarized targets which allowed the extraction of information on the spin-dependent part of the triangle-nucleon interaction. At the Indiana Universitymore » Cyclotron Facility (IUCF) we studied proton-induced charge exchange reactions with results of importance to astrophysics and the nuclear few-body problem. During the first few years, the analysis of heavy-ion nucleus scattering data that had been taken prior to 1979 was completed. During the last few years we created hypernuclei by use of a kaon beam at Brookhaven National Laboratory (BNL) and an electron beam at Jefferson Laboratory (JLab). The data taken at BNL for a study of the non-mesonic weak decay of the A particle in a nucleus are still under analysis by our collaborators. The work at JLab resulted in the best resolution hypernuclear spectra measured thus far with magnetic spectrometers.« less

  18. Is black-hole ringdown a memory of its progenitor?

    PubMed

    Kamaretsos, Ioannis; Hannam, Mark; Sathyaprakash, B S

    2012-10-05

    We perform an extensive numerical study of coalescing black-hole binaries to understand the gravitational-wave spectrum of quasinormal modes excited in the merged black hole. Remarkably, we find that the masses and spins of the progenitor are clearly encoded in the mode spectrum of the ringdown signal. Some of the mode amplitudes carry the signature of the binary's mass ratio, while others depend critically on the spins. Simulations of precessing binaries suggest that our results carry over to generic systems. Using Bayesian inference, we demonstrate that it is possible to accurately measure the mass ratio and a proper combination of spins even when the binary is itself invisible to a detector. Using a mapping of the binary masses and spins to the final black-hole spin allows us to further extract the spin components of the progenitor. Our results could have tremendous implications for gravitational astronomy by facilitating novel tests of general relativity using merging black holes.

  19. EVLA Constraints on the Progenitors of Supernovae Type Ia

    NASA Astrophysics Data System (ADS)

    Chomiuk, Laura; Soderberg, A. M.; Chevalier, R.; Badenes, C.; Fransson, C.

    2011-01-01

    While Type Ia supernovae are used increasingly as cosmological probes to trace the expansion history of the Universe, the nature of their progenitors remains enshrouded in mystery. In the favored model for these explosions, a white dwarf accretes material from a hydrogen-rich donor star (e.g. red giant). A necessary implication of this model is the production of weak radio emission as the SN blastwave plows through the wind of the donor star. Previous radio searches for this signal have been unsuccessful, largely attributed to the fact that the expected emission lay just beyond the VLA sensitivity. Here we present recent results from our EVLA program, which utilizes the increased sensitivity to search for the expected signal from SNe Ia. The non-detection of radio emission with the EVLA would indicate double-degenerate progenitor systems (binary white dwarf) or require serious modifications to the single-degenerate model.

  20. Differentiation of Inflammation-Responsive Astrocytes from Glial Progenitors Generated from Human Induced Pluripotent Stem Cells.

    PubMed

    Santos, Renata; Vadodaria, Krishna C; Jaeger, Baptiste N; Mei, Arianna; Lefcochilos-Fogelquist, Sabrina; Mendes, Ana P D; Erikson, Galina; Shokhirev, Maxim; Randolph-Moore, Lynne; Fredlender, Callie; Dave, Sonia; Oefner, Ruth; Fitzpatrick, Conor; Pena, Monique; Barron, Jerika J; Ku, Manching; Denli, Ahmet M; Kerman, Bilal E; Charnay, Patrick; Kelsoe, John R; Marchetto, Maria C; Gage, Fred H

    2017-06-06

    Astrocyte dysfunction and neuroinflammation are detrimental features in multiple pathologies of the CNS. Therefore, the development of methods that produce functional human astrocytes represents an advance in the study of neurological diseases. Here we report an efficient method for inflammation-responsive astrocyte generation from induced pluripotent stem cells (iPSCs) and embryonic stem cells. This protocol uses an intermediate glial progenitor stage and generates functional astrocytes that show levels of glutamate uptake and calcium activation comparable with those observed in human primary astrocytes. Stimulation of stem cell-derived astrocytes with interleukin-1β or tumor necrosis factor α elicits a strong and rapid pro-inflammatory response. RNA-sequencing transcriptome profiling confirmed that similar gene expression changes occurred in iPSC-derived and primary astrocytes upon stimulation with interleukin-1β. This protocol represents an important tool for modeling in-a-dish neurological diseases with an inflammatory component, allowing for the investigation of the role of diseased astrocytes in neuronal degeneration. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  1. ECSIT links TLR and BMP signaling in FOP connective tissue progenitor cells.

    PubMed

    Wang, Haitao; Behrens, Edward M; Pignolo, Robert J; Kaplan, Frederick S

    2018-04-01

    Clinical and laboratory observations strongly suggest that the innate immune system induces flare-ups in the setting of dysregulated bone morphogenetic protein (BMP) signaling in fibrodysplasia ossificans progressiva (FOP). In order to investigate the signaling substrates of this hypothesis, we examined toll-like receptor (TLR) activation and bone morphogenetic protein (BMP) signaling in connective tissue progenitor cells (CTPCs) from FOP patients and unaffected individuals. We found that inflammatory stimuli broadly activate TLR expression in FOP CTPCs and that TLR3/TLR4 signaling amplifies BMP pathway signaling through both ligand dependent and independent mechanisms. Importantly, Evolutionarily Conserved Signaling Intermediate in the Toll Pathway (ECSIT) integrates TLR injury signaling with dysregulated BMP pathway signaling in FOP CTPCs. These findings provide novel insight into the cell autonomous integration of injury signals from the innate immune system with dysregulated response signals from the BMP signaling pathway and provide new exploratory targets for therapeutic approaches to blocking the induction and amplification of FOP lesions. Copyright © 2018 Elsevier Inc. All rights reserved.

  2. A Pan-Carina Young Stellar Object Catalog: Intermediate-mass Young Stellar Objects in the Carina Nebula Identified Via Mid-infrared Excess Emission

    NASA Astrophysics Data System (ADS)

    Povich, Matthew S.; Smith, Nathan; Majewski, Steven R.; Getman, Konstantin V.; Townsley, Leisa K.; Babler, Brian L.; Broos, Patrick S.; Indebetouw, Rémy; Meade, Marilyn R.; Robitaille, Thomas P.; Stassun, Keivan G.; Whitney, Barbara A.; Yonekura, Yoshinori; Fukui, Yasuo

    2011-05-01

    We present a catalog of 1439 young stellar objects (YSOs) spanning the 1.42 deg2 field surveyed by the Chandra Carina Complex Project (CCCP), which includes the major ionizing clusters and the most active sites of ongoing star formation within the Great Nebula in Carina. Candidate YSOs were identified via infrared (IR) excess emission from dusty circumstellar disks and envelopes, using data from the Spitzer Space Telescope (the Vela-Carina survey) and the Two-Micron All Sky Survey. We model the 1-24 μm IR spectral energy distributions of the YSOs to constrain physical properties. Our Pan-Carina YSO Catalog (PCYC) is dominated by intermediate-mass (2 M sun < m <~ 10 M sun) objects with disks, including Herbig Ae/Be stars and their less evolved progenitors. The PCYC provides a valuable complementary data set to the CCCP X-ray source catalogs, identifying 1029 YSOs in Carina with no X-ray detection. We also catalog 410 YSOs with X-ray counterparts, including 62 candidate protostars. Candidate protostars with X-ray detections tend to be more evolved than those without. In most cases, X-ray emission apparently originating from intermediate-mass, disk-dominated YSOs is consistent with the presence of low-mass companions, but we also find that X-ray emission correlates with cooler stellar photospheres and higher disk masses. We suggest that intermediate-mass YSOs produce X-rays during their early pre-main-sequence evolution, perhaps driven by magnetic dynamo activity during the convective atmosphere phase, but this emission dies off as the stars approach the main sequence. Extrapolating over the stellar initial mass function scaled to the PCYC population, we predict a total population of >2 × 104 YSOs and a present-day star formation rate (SFR) of >0.008 M sun yr-1. The global SFR in the Carina Nebula, averaged over the past ~5 Myr, has been approximately constant.

  3. On the Progenitor System of V392 Persei

    NASA Astrophysics Data System (ADS)

    Darnley, M. J.; Starrfield, S.

    2018-05-01

    A discussion regarding the progenitor system of the nova and dwarf nova system V392 Persei using archival data from 2MASS and WISE. We find that the system is unlikely to contain a luminous red giant donor (i.e. a symbiotic system), but cannot exclude the presence of a lower luminosity red giant or a sub-giant donor. The similarity of the SED of the quiescent V392 Per to that of GK Persei is noted.

  4. Declining lymphoid progenitor fitness promotes aging-associated leukemogenesis.

    PubMed

    Henry, Curtis J; Marusyk, Andriy; Zaberezhnyy, Vadym; Adane, Biniam; DeGregori, James

    2010-12-14

    Aging is associated with the functional decline of cells, tissues, and organs. At the same time, age is the single most important prognostic factor in the development of most human cancers, including chronic myelogenous and acute lymphoblastic leukemias initiated by Bcr-Abl oncogenic translocations. Prevailing paradigms attribute the association between aging and cancers to the accumulation of oncogenic mutations over time, because the accrual of oncogenic events is thought to be the rate-limiting step in initiation and progression of cancers. Conversely, aging-associated functional decline caused by both cell-autonomous and non-cell-autonomous mechanisms is likely to reduce the fitness of stem and progenitor cell populations. This reduction in fitness should be conducive for increased selection of oncogenic mutations that can at least partially alleviate fitness defects, thereby promoting the initiation of cancers. We tested this hypothesis using mouse hematopoietic models. Our studies indicate that the dramatic decline in the fitness of aged B-lymphopoiesis coincides with altered receptor-associated kinase signaling. We further show that Bcr-Abl provides a much greater competitive advantage to old B-lymphoid progenitors compared with young progenitors, coinciding with restored kinase signaling pathways, and that this enhanced competitive advantage translates into increased promotion of Bcr-Abl-driven leukemias. Moreover, impairing IL-7-mediated signaling is sufficient to promote selection for Bcr-Abl-expressing B progenitors. These studies support an unappreciated causative link between aging and cancer: increased selection of oncogenic mutations as a result of age-dependent alterations of the fitness landscape.

  5. Circulating endothelial progenitor cells in obese children and adolescents.

    PubMed

    Pires, António; Martins, Paula; Paiva, Artur; Pereira, Ana Margarida; Marques, Margarida; Castela, Eduardo; Sena, Cristina; Seiça, Raquel

    2015-01-01

    This study aimed to investigate the relationship between circulating endothelial progenitor cell count and endothelial activation in a pediatric population with obesity. Observational and transversal study, including 120 children and adolescents with primary obesity of both sexes, aged 6-17 years, who were recruited at this Cardiovascular Risk Clinic. The control group was made up of 41 children and adolescents with normal body mass index. The variables analyzed were: age, gender, body mass index, systolic and diastolic blood pressure, high-sensitivity C-reactive protein, lipid profile, leptin, adiponectin, homeostasis model assessment-insulin resistance, monocyte chemoattractant protein-1, E-selectin, asymmetric dimethylarginine and circulating progenitor endothelial cell count. Insulin resistance was correlated to asymmetric dimethylarginine (ρ=0.340; p=0.003), which was directly, but weakly correlated to E-selectin (ρ=0.252; p=0.046). High sensitivity C-reactive protein was not found to be correlated to markers of endothelial activation. Systolic blood pressure was directly correlated to body mass index (ρ=0.471; p<0.001) and the homeostasis model assessment-insulin resistance (ρ=0.230; p=0.012), and inversely correlated to adiponectin (ρ=-0.331; p<0.001) and high-density lipoprotein cholesterol (ρ=-0.319; p<0.001). Circulating endothelial progenitor cell count was directly, but weakly correlated, to body mass index (r=0.211; p=0.016), leptin (ρ=0.245; p=0.006), triglyceride levels (r=0.241; p=0.031), and E-selectin (ρ=0.297; p=0.004). Circulating endothelial progenitor cell count is elevated in obese children and adolescents with evidence of endothelial activation, suggesting that, during infancy, endothelial repairing mechanisms are present in the context of endothelial activation. Copyright © 2015 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  6. Constraints on the Progenitor System of SN 2016gkg from a Comprehensive Statistical Analysis

    NASA Astrophysics Data System (ADS)

    Sravan, Niharika; Marchant, Pablo; Kalogera, Vassiliki; Margutti, Raffaella

    2018-01-01

    Type IIb supernovae (SNe) present a unique opportunity for understanding the progenitors of stripped-envelope SNe because the stellar progenitor of several SNe IIb have been identified in pre-explosion images. In this paper, we use Bayesian inference and a large grid of non-rotating solar-metallicity single and binary stellar models to derive the associated probability distributions of single and binary progenitors of the SN IIb 2016gkg using existing observational constraints. We find that potential binary star progenitors have smaller pre-SN hydrogen-envelope and helium-core masses than potential single-star progenitors typically by 0.1 M ⊙ and 2 M ⊙, respectively. We find that, a binary companion, if present, is a main-sequence or red-giant star. Apart from this, we do not find strong constraints on the nature of the companion star. We demonstrate that the range of progenitor helium-core mass inferred from observations could help improve constraints on the progenitor. We find that the probability that the progenitor of SN 2016gkg was a binary is 22% when we use constraints only on the progenitor luminosity and effective temperature. Imposing the range of pre-SN progenitor hydrogen-envelope mass and radius inferred from SN light curves, the probability that the progenitor is a binary increases to 44%. However, there is no clear preference for a binary progenitor. This is in contrast to binaries being the currently favored formation channel for SNe IIb. Our analysis demonstrates the importance of statistical inference methods to constrain progenitor channels.

  7. Endothelial Progenitor Cells as Shuttle of Anticancer Agents.

    PubMed

    Laurenzana, Anna; Margheri, Francesca; Chillà, Anastasia; Biagioni, Alessio; Margheri, Giancarlo; Calorini, Lido; Fibbi, Gabriella; Del Rosso, Mario

    2016-10-01

    Cell therapies are treatments in which stem or progenitor cells are stimulated to differentiate into specialized cells able to home to and repair damaged tissues. After their discovery, endothelial progenitor cells (EPCs) stimulated worldwide interest as possible vehicles to perform autologous cell therapy of tumors. Taking into account the tumor-homing properties of EPCs, two different approaches to control cancer progression have been pursued by combining cell-based therapy with gene therapy or with nanomedicine. The first approach is based on the possibility of engineering EPCs to express different transgenes, and the second is based on the capacity of EPCs to take up nanomaterials. Here we review the most important progress covering the following issues: the characterization of bona fide endothelial progenitor cells, their role in tumor vascularization and metastasis, and preclinical data about their use in cell-based tumor therapy, considering antiangiogenic, suicide, immune-stimulating, and oncolytic virus gene therapy. The mixed approach of EPC cell therapy and nanomedicine is discussed in terms of plasmonic-dependent thermoablation and molecular imaging.

  8. Epigenome profiling and editing of neocortical progenitor cells during development.

    PubMed

    Albert, Mareike; Kalebic, Nereo; Florio, Marta; Lakshmanaperumal, Naharajan; Haffner, Christiane; Brandl, Holger; Henry, Ian; Huttner, Wieland B

    2017-09-01

    The generation of neocortical neurons from neural progenitor cells (NPCs) is primarily controlled by transcription factors binding to DNA in the context of chromatin. To understand the complex layer of regulation that orchestrates different NPC types from the same DNA sequence, epigenome maps with cell type resolution are required. Here, we present genomewide histone methylation maps for distinct neural cell populations in the developing mouse neocortex. Using different chromatin features, we identify potential novel regulators of cortical NPCs. Moreover, we identify extensive H3K27me3 changes between NPC subtypes coinciding with major developmental and cell biological transitions. Interestingly, we detect dynamic H3K27me3 changes on promoters of several crucial transcription factors, including the basal progenitor regulator Eomes We use catalytically inactive Cas9 fused with the histone methyltransferase Ezh2 to edit H3K27me3 at the Eomes locus in vivo , which results in reduced Tbr2 expression and lower basal progenitor abundance, underscoring the relevance of dynamic H3K27me3 changes during neocortex development. Taken together, we provide a rich resource of neocortical histone methylation data and outline an approach to investigate its contribution to the regulation of selected genes during neocortical development. © 2017 The Authors.

  9. Towards the therapeutic use of vascular smooth muscle progenitor cells.

    PubMed

    Merkulova-Rainon, Tatyana; Broquères-You, Dong; Kubis, Nathalie; Silvestre, Jean-Sébastien; Lévy, Bernard I

    2012-07-15

    Recent advances in the development of alternative proangiogenic and revascularization processes, including recombinant protein delivery, gene therapy, and cell therapy, hold the promise of greater efficacy in the management of cardiovascular disease in the coming years. In particular, vascular progenitor cell-based strategies have emerged as an efficient treatment approach to promote vessel formation and repair and to improve tissue perfusion. During the past decade, considerable progress has been achieved in understanding therapeutic properties of endothelial progenitor cells, while the therapeutic potential of vascular smooth muscle progenitor cells (SMPC) has only recently been explored; the number of the circulating SMPC being correlated with cardiovascular health. Several endogenous SMPC populations with varying phenotypes have been identified and characterized in the peripheral blood, bone marrow, and vascular wall. While the phenotypic entity of vascular SMPC is not fully defined and remains an evolving area of research, SMPC are increasingly recognized to play a special role in cardiovascular biology. In this review, we describe the current approaches used to define vascular SMPC. We further summarize the data on phenotype and functional properties of SMPC from various sources in adults. Finally, we discuss the role of SMPC in cardiovascular disease, including the contribution of SMPC to intimal proliferation, angiogenesis, and atherosclerotic plaque instability as well as the benefits resulting from the therapeutic use of SMPC.

  10. The supply of choline is important for fetal progenitor cells

    PubMed Central

    Zeisel, Steven H.

    2011-01-01

    Fetal progenitor cells proliferate, migrate, differentiate and undergo apoptosis at specific times during fetal development. Choline is needed by these cells for membrane synthesis and for methylation. There is growing evidence that this nutrient also modulates epigenetic regulation of gene expression in both neuronal and endothelial progenitor cells, thereby modifying brain development. It is likely that these mechanisms explain why, in rodent models, maternal dietary intake of choline influences both angiogenesis and neurogenesis in fetal hippocampus, and results in life-long changes in memory function. This also may explain why women eating diets low in choline have a greater risk of having a baby with a birth defect. Choline is mainly found in foods that contain fat and cholesterol, and intake of such foods has diminished in response dietary advice from nutritionists and physicians. Forty years ago, diets commonly contained choline-rich foods but now women in the USA tend to eat diets low in choline content. Premenopausal women normally may require less choline in their diet than do men and postmenopausal women, because estrogen induces the gene for the enzyme catalyzing endogenous biosynthesis of the choline-containing phospholipid phosphatidylcholine. However, many women have a single nucleotide polymorphism (SNP) that blocks the induction of endogenous biosynthesis, thereby making them require more dietary choline. When these women eat diets low in choline, the supply of this nutrient to the fetus is likely to be inadequate, and may perturb progenitor cell proliferation, migration, differentiation and apoptosis. PMID:21693194

  11. No hot and luminous progenitor for Tycho's supernova

    NASA Astrophysics Data System (ADS)

    Woods, T. E.; Ghavamian, P.; Badenes, C.; Gilfanov, M.

    2017-11-01

    Type Ia supernovae have proven vital to our understanding of cosmology, both as standard candles and for their role in galactic chemical evolution; however, their origin remains uncertain. The canonical accretion model implies a hot and luminous progenitor that would ionize the surrounding gas out to a radius of 10-100 pc for 100,000 years after the explosion. Here, we report stringent upper limits on the temperature and luminosity of the progenitor of Tycho's supernova (SN 1572), determined using the remnant itself as a probe of its environment. Hot, luminous progenitors that would have produced a greater hydrogen ionization fraction than that measured at the radius of the present remnant ( 3 pc) can thus be excluded. This conclusively rules out steadily nuclear-burning white dwarfs (supersoft X-ray sources), as well as disk emission from a Chandrasekhar-mass white dwarf accreting approximately greater than 10-8 M⊙ yr-1 (recurrent novae; M⊙ is equal to one solar mass). The lack of a surrounding Strömgren sphere is consistent with the merger of a double white dwarf binary, although other more exotic scenarios may be possible.

  12. Lead exposure delays the differentiation of oligodendroglial progenitors in vitro.

    PubMed

    Deng, W; McKinnon, R D; Poretz, R D

    2001-08-01

    Lead (Pb) is an environmental neurotoxicant that can cause hypo- and demyelination. Oligodendrocytes (OLs), the myelin-forming cells in the central nervous system, may be a possible target for Pb toxicity. The present study describes the effect of Pb on the maturation of rat OL progenitor (OP) cells and the developmental expression of myelin-specific galactolipids. Dose-response studies showed that OP cultures were more sensitive to Pb than mature OLs. Pb delayed the differentiation of OL progenitors, as demonstrated by cell morphology and immunostaining with a panel of stage-specific differentiation markers. Pb given prior to and during differentiation caused a decrease in the biosynthesis of galactolipids in both undifferentiated and differentiated OLs, as detected by metabolic radiolabeling with 3H-D-galactose. While the ratios of galacto/gluco-cerebrosides, hydroxy fatty acid/nonhydroxy fatty acid galactolipids, and galactocerebrosides/sulfatides increased in control cultures during cell differentiation, Pb treatment prevented these changes. The results suggest that chronic Pb exposure may impact brain development by interfering with the timely developmental maturation of OL progenitors. Copyright 2001 Academic Press.

  13. Oligodendrocytes and Progenitors Become Progressively Depleted within Chronically Demyelinated Lesions

    PubMed Central

    Mason, Jeffrey L.; Toews, Arrel; Hostettler, Janell D.; Morell, Pierre; Suzuki, Kinuko; Goldman, James E.; Matsushima, Glenn K.

    2004-01-01

    To understand mechanisms that may underlie the progression of a demyelinated lesion to a chronic state, we have used the cuprizone model of chronic demyelination. In this study, we investigated the fate of oligodendrocytes during the progression of a demyelinating lesion to a chronic state and determined whether transplanted adult oligodendrocyte progenitors could remyelinate the chronically demyelinated axons. Although there is rapid regeneration of the oligodendrocyte population following an acute lesion, most of these newly regenerated cells undergo apoptosis if mice remain on a cuprizone diet. Furthermore, the oligodendrocyte progenitors also become progressively depleted within the lesion, which appears to contribute to the chronic demyelination. Interestingly, even if the mice are returned to a normal diet following 12 weeks of exposure to cuprizone, remyelination and oligodendrocyte regeneration does not occur. However, if adult O4+ progenitors are transplanted into the chronically demyelinated lesion of mice treated with cuprizone for 12 weeks, mature oligodendrocyte regeneration and remyelination occurs after the mice are returned to a normal diet. Thus, the formation of chronically demyelinated lesions induced by cuprizone appears to be the result of oligodendrocyte depletion within the lesion and not due to the inability of the chronically demyelinated axons to be remyelinated. PMID:15111314

  14. Centroacinar Cells Are Progenitors That Contribute to Endocrine Pancreas Regeneration

    PubMed Central

    Delaspre, Fabien; Beer, Rebecca L.; Rovira, Meritxell; Huang, Wei; Wang, Guangliang; Gee, Stephen; Vitery, Maria del Carmen; Wheelan, Sarah J.

    2015-01-01

    Diabetes is associated with a paucity of insulin-producing β-cells. With the goal of finding therapeutic routes to treat diabetes, we aim to find molecular and cellular mechanisms involved in β-cell neogenesis and regeneration. To facilitate discovery of such mechanisms, we use a vertebrate organism where pancreatic cells readily regenerate. The larval zebrafish pancreas contains Notch-responsive progenitors that during development give rise to adult ductal, endocrine, and centroacinar cells (CACs). Adult CACs are also Notch responsive and are morphologically similar to their larval predecessors. To test our hypothesis that adult CACs are also progenitors, we took two complementary approaches: 1) We established the transcriptome for adult CACs. Using gene ontology, transgenic lines, and in situ hybridization, we found that the CAC transcriptome is enriched for progenitor markers. 2) Using lineage tracing, we demonstrated that CACs do form new endocrine cells after β-cell ablation or partial pancreatectomy. We concluded that CACs and their larval predecessors are the same cell type and represent an opportune model to study both β-cell neogenesis and β-cell regeneration. Furthermore, we show that in cftr loss-of-function mutants, there is a deficiency of larval CACs, providing a possible explanation for pancreatic complications associated with cystic fibrosis. PMID:26153247

  15. Reprogramming mouse fibroblasts into engraftable myeloerythroid and lymphoid progenitors

    PubMed Central

    Cheng, Hui; Ang, Heather Yin-Kuan; A. EL Farran, Chadi; Li, Pin; Fang, Hai Tong; Liu, Tong Ming; Kong, Say Li; Chin, Michael Lingzi; Ling, Wei Yin; Lim, Edwin Kok Hao; Li, Hu; Huber, Tara; Loh, Kyle M.; Loh, Yuin-Han; Lim, Bing

    2016-01-01

    Recent efforts have attempted to convert non-blood cells into hematopoietic stem cells (HSCs) with the goal of generating blood lineages de novo. Here we show that hematopoietic transcription factors Scl, Lmo2, Runx1 and Bmi1 can convert a developmentally distant lineage (fibroblasts) into ‘induced hematopoietic progenitors' (iHPs). Functionally, iHPs generate acetylcholinesterase+ megakaryocytes and phagocytic myeloid cells in vitro and can also engraft immunodeficient mice, generating myeloerythoid and B-lymphoid cells for up to 4 months in vivo. Molecularly, iHPs transcriptionally resemble native Kit+ hematopoietic progenitors. Mechanistically, reprogramming factor Lmo2 implements a hematopoietic programme in fibroblasts by rapidly binding to and upregulating the Hhex and Gfi1 genes within days. Moreover the reprogramming transcription factors also require extracellular BMP and MEK signalling to cooperatively effectuate reprogramming. Thus, the transcription factors that orchestrate embryonic hematopoiesis can artificially reconstitute this programme in developmentally distant fibroblasts, converting them into engraftable blood progenitors. PMID:27869129

  16. Morphological and functional aspects of progenitors perturbed in cortical malformations

    PubMed Central

    Bizzotto, Sara; Francis, Fiona

    2015-01-01

    In this review, we discuss molecular and cellular mechanisms important for the function of neuronal progenitors during development, revealed by their perturbation in different cortical malformations. We focus on a class of neuronal progenitors, radial glial cells (RGCs), which are renowned for their unique morphological and behavioral characteristics, constituting a key element during the development of the mammalian cerebral cortex. We describe how the particular morphology of these cells is related to their roles in the orchestration of cortical development and their influence on other progenitor types and post-mitotic neurons. Important for disease mechanisms, we overview what is currently known about RGC cellular components, cytoskeletal mechanisms, signaling pathways and cell cycle characteristics, focusing on how defects lead to abnormal development and cortical malformation phenotypes. The multiple recent entry points from human genetics and animal models are contributing to our understanding of this important cell type. Combining data from phenotypes in the mouse reveals molecules which potentially act in common pathways. Going beyond this, we discuss future directions that may provide new data in this expanding area. PMID:25729350

  17. Progenitor cell domains in the developing and adult pancreas

    PubMed Central

    Kopp, Janel L; Dubois, Claire L; Hao, Ergeng; Thorel, Fabrizio; Herrera, Pedro L

    2011-01-01

    Unlike organs with defined stem cell compartments, such as the intestine, the pancreas has limited capacity to regenerate. The question of whether the adult pancreas harbors facultative stem/progenitor cells has been a prime subject of debate. Cumulative evidence from recent genetic lineage tracing studies, in which specific cell populations were marked and traced in adult mice, suggests that endocrine and acinar cells are no longer generated from progenitors in the adult pancreas. These studies further indicate that adult pancreatic ductal cells are not a source for endocrine cells following pancreatic injury, as previously suggested. Our own studies have shown that adult ductal cells reinitiate expression of some endocrine progenitor markers, including Ngn3, after injury by partial duct ligation (PDL), but that these cells do not undergo endocrine cell differentiation. Here, we present additional evidence that endocrine cells do not arise from ducts following β-cell ablation by streptozotocin or by a diphtheria toxin-expressing transgene or when β-cell ablation is combined with PDL. In this review, we discuss findings from recent lineage tracing studies of embryonic and adult pancreatic ductal cells. Based upon the combined evidence from these studies, we propose that multipotency is associated with a specific transcriptional signature. PMID:21558806

  18. NOTCH signaling in skeletal progenitors is critical for fracture repair

    PubMed Central

    Wang, Cuicui; Inzana, Jason A.; Mirando, Anthony J.; Liu, Zhaoyang; Shen, Jie; O’Keefe, Regis J.; Awad, Hani A.; Hilton, Matthew J.

    2016-01-01

    Fracture nonunions develop in 10%–20% of patients with fractures, resulting in prolonged disability. Current data suggest that bone union during fracture repair is achieved via proliferation and differentiation of skeletal progenitors within periosteal and soft tissues surrounding bone, while bone marrow stromal/stem cells (BMSCs) and other skeletal progenitors may also contribute. The NOTCH signaling pathway is a critical maintenance factor for BMSCs during skeletal development, although the precise role for NOTCH and the requisite nature of BMSCs following fracture is unknown. Here, we evaluated whether NOTCH and/or BMSCs are required for fracture repair by performing nonstabilized and stabilized fractures on NOTCH-deficient mice with targeted deletion of RBPjk in skeletal progenitors, maturing osteoblasts, and committed chondrocytes. We determined that removal of NOTCH signaling in BMSCs and subsequent depletion of this population result in fracture nonunion, as the fracture repair process was normal in animals harboring either osteoblast- or chondrocyte-specific deletion of RBPjk. Together, this work provides a genetic model of a fracture nonunion and demonstrates the requirement for NOTCH and BMSCs in fracture repair, irrespective of fracture stability and vascularity. PMID:26950423

  19. Probing massive stars around gamma-ray burst progenitors

    NASA Astrophysics Data System (ADS)

    Lu, Wenbin; Kumar, Pawan; Smoot, George F.

    2015-10-01

    Long gamma-ray bursts (GRBs) are produced by ultra-relativistic jets launched from core collapse of massive stars. Most massive stars form in binaries and/or in star clusters, which means that there may be a significant external photon field (EPF) around the GRB progenitor. We calculate the inverse-Compton scattering of EPF by the hot electrons in the GRB jet. Three possible cases of EPF are considered: the progenitor is (I) in a massive binary system, (II) surrounded by a Wolf-Rayet-star wind and (III) in a dense star cluster. Typical luminosities of 1046-1050 erg s-1 in the 1-100 GeV band are expected, depending on the stellar luminosity, binary separation (I), wind mass-loss rate (II), stellar number density (III), etc. We calculate the light curve and spectrum in each case, taking fully into account the equal-arrival time surfaces and possible pair-production absorption with the prompt γ-rays. Observations can put constraints on the existence of such EPFs (and hence on the nature of GRB progenitors) and on the radius where the jet internal dissipation process accelerates electrons.

  20. Chlorpyrifos induces oxidative stress in oligodendrocyte progenitor cells.

    PubMed

    Saulsbury, Marilyn D; Heyliger, Simone O; Wang, Kaiyu; Johnson, Deadre J

    2009-05-02

    There are increasing concerns regarding the relative safety of chlorpyrifos (CPF) to various facets of the environment. Although published works suggest that CPF is relatively safe in adult animals, recent evidence indicates that juveniles, both animals and humans, may be more sensitive to CPF toxicity than adults. In young animals, CPF is neurotoxic and mechanistically interferes with cellular replication and cellular differentiation, which culminates in the alteration of synaptic neurotransmission in neurons. However, the effects of CPF on glial cells are not fully elucidated. Here we report that chlorpyrifos is toxic to oligodendrocyte progenitors. In addition, CPF produced dose-dependent increases in 2',7'-dichlorodihydrofluorescein diacetate (H(2)DCF-DA) and dihydroethidium (DHE) fluorescence intensities relative to the vehicle control. Moreover, CPF toxicity is associated with nuclear condensation and elevation of caspase 3/7 activity and Heme oxygenase-1 mRNA expression. Pan-caspase inhibitor QVDOPh and cholinergic receptor antagonists' atropine and mecamylamine failed to protect oligodendrocyte progenitors from CPF-induced injury. Finally, glutathione (GSH) depletion enhanced CPF-induced toxicity whereas nitric oxide synthetase inhibitor L-NAME partially protected progenitors and the non-specific antioxidant vitamin E (alpha-tocopherol) completely spared cells from injury. Collectively, this data suggests that CPF induced toxicity is independent of cholinergic stimulation and is most likely caused by the induction of oxidative stress.

  1. Reversing resistance to vascular-disrupting agents by blocking late mobilization of circulating endothelial progenitor cells.

    PubMed

    Taylor, Melissa; Billiot, Fanny; Marty, Virginie; Rouffiac, Valérie; Cohen, Patrick; Tournay, Elodie; Opolon, Paule; Louache, Fawzia; Vassal, Gilles; Laplace-Builhé, Corinne; Vielh, Philippe; Soria, Jean-Charles; Farace, Françoise

    2012-05-01

    The prevailing concept is that immediate mobilization of bone marrow-derived circulating endothelial progenitor cells (CEP) is a key mechanism mediating tumor resistance to vascular-disrupting agents (VDA). Here, we show that administration of VDA to tumor-bearing mice induces 2 distinct peaks in CEPs: an early, unspecific CEP efflux followed by a late yet more dramatic tumor-specific CEP burst that infiltrates tumors and is recruited to vessels. Combination with antiangiogenic drugs could not disrupt the early peak but completely abrogated the late VDA-induced CEP burst, blunted bone marrow-derived cell recruitment to tumors, and resulted in striking antitumor efficacy, indicating that the late CEP burst might be crucial to tumor recovery after VDA therapy. CEP and circulating endothelial cell kinetics in VDA-treated patients with cancer were remarkably consistent with our preclinical data. These findings expand the current understanding of vasculogenic "rebounds" that may be targeted to improve VDA-based strategies. Our findings suggest that resistance to VDA therapy may be strongly mediated by late, rather than early, tumor-specific recruitment of CEPs, the suppression of which resulted in increased VDA-mediated antitumor efficacy. VDA-based therapy might thus be significantly enhanced by combination strategies targeting late CEP mobilization. © 2012 AACR

  2. Notch Signaling in Postnatal Pituitary Expansion: Proliferation, Progenitors, and Cell Specification

    PubMed Central

    Nantie, Leah B.; Himes, Ashley D.; Getz, Dan R.

    2014-01-01

    Mutations in PROP1 account for up to half of the cases of combined pituitary hormone deficiency that result from known causes. Despite this, few signaling molecules and pathways that influence PROP1 expression have been identified. Notch signaling has been linked to Prop1 expression, but the developmental periods during which Notch signaling influences Prop1 and overall pituitary development remain unclear. To test the requirement for Notch signaling in establishing the normal pituitary hormone milieu, we generated mice with early embryonic conditional loss of Notch2 (conditional knockout) and examined the consequences of chemical Notch inhibition during early postnatal pituitary maturation. We show that loss of Notch2 has little influence on early embryonic pituitary proliferation but is crucial for postnatal progenitor maintenance and proliferation. In addition, we show that Notch signaling is necessary embryonically and postnatally for Prop1 expression and robust Pit1 lineage hormone cell expansion, as well as repression of the corticotrope lineage. Taken together, our studies identify temporal and cell type–specific roles for Notch signaling and highlight the importance of this pathway throughout pituitary development. PMID:24673559

  3. Neighbor of Punc E 11: expression pattern of the new hepatic stem/progenitor cell marker during murine liver development.

    PubMed

    Schievenbusch, Stephanie; Sauer, Elisabeth; Curth, Harald-Morten; Schulte, Sigrid; Demir, Münevver; Toex, Ulrich; Goeser, Tobias; Nierhoff, Dirk

    2012-09-20

    We have previously identified Neighbor of Punc E 11 (Nope) as a specific cell surface marker of stem/progenitor cells in the murine fetal liver that is also expressed in hepatocellular carcinoma. Here, we focus on the differential expression pattern of Nope during murine fetal and postnatal liver development as well as in a normal and regenerating adult liver including oval cell activation. In the fetal liver, Nope shows a constantly high expression level and is a useful surface marker for the identification of Dlk, E-cadherin, and CD133-positive hepatoblasts by flow cytometry. Postnatally, Nope expression declines rapidly and remains barely detectable in the adult liver as shown by quantitative real-time reverse-transcriptase polymerase chain reaction and western blot analyses. Immunohistochemically, costainings for Nope- and epithelial-specific markers (E-cadherin), markers of early hepatoblasts (alpha-fetoprotein), and biliary marker proteins (CK19) demonstrate that Nope is initially expressed on bipotent hepatoblasts and persists thereafter on commited hepatocytic as well as cholangiocytic progenitor cells during late fetal liver development. Postnatally, Nope loses its circular expression pattern and is specifically directed to the sinusoidal membrane of early hepatocytes. While Nope is only weakly expressed on cholangiocytes in the normal adult liver, activated stem/progenitor (oval) cells clearly coexpress Nope together with the common markers A6, EpCAM, and CD24 in the 3,5-diethoxycarbonyl-1,4-dihydrocollidine mouse model. In conclusion, Nope should be most useful in future research to define the differentiation stage of hepatic-specified cells of various sources and is a promising candidate to identify and isolate hepatic stem cells from the adult liver.

  4. DKK1 mediated inhibition of Wnt signaling in postnatal mice leads to loss of TEC progenitors and thymic degeneration.

    PubMed

    Osada, Masako; Jardine, Logan; Misir, Ruth; Andl, Thomas; Millar, Sarah E; Pezzano, Mark

    2010-02-08

    Thymic epithelial cell (TEC) microenvironments are essential for the recruitment of T cell precursors from the bone marrow, as well as the subsequent expansion and selection of thymocytes resulting in a mature self-tolerant T cell repertoire. The molecular mechanisms, which control both the initial development and subsequent maintenance of these critical microenvironments, are poorly defined. Wnt signaling has been shown to be important to the development of several epithelial tissues and organs. Regulation of Wnt signaling has also been shown to impact both early thymocyte and thymic epithelial development. However, early blocks in thymic organogenesis or death of the mice have prevented analysis of a role of canonical Wnt signaling in the maintenance of TECs in the postnatal thymus. Here we demonstrate that tetracycline-regulated expression of the canonical Wnt inhibitor DKK1 in TECs localized in both the cortex and medulla of adult mice, results in rapid thymic degeneration characterized by a loss of DeltaNP63(+) Foxn1(+) and Aire(+) TECs, loss of K5K8DP TECs thought to represent or contain an immature TEC progenitor, decreased TEC proliferation and the development of cystic structures, similar to an aged thymus. Removal of DKK1 from DKK1-involuted mice results in full recovery, suggesting that canonical Wnt signaling is required for the differentiation or proliferation of TEC populations needed for maintenance of properly organized adult thymic epithelial microenvironments. Taken together, the results of this study demonstrate that canonical Wnt signaling within TECs is required for the maintenance of epithelial microenvironments in the postnatal thymus, possibly through effects on TEC progenitor/stem cell populations. Downstream targets of Wnt signaling, which are responsible for maintenance of these TEC progenitors may provide useful targets for therapies aimed at counteracting age associated thymic involution or the premature thymic degeneration associated

  5. [The advance in synthetic biology: towards a microbe-derived paclitaxel intermediates].

    PubMed

    Wang, Wei; Yang, Yan; Zheng, Xiao-Dong; Huang, Shu-Qiong; Guo, Lei; Kong, Jian-Qiang; Cheng, Ke-Di

    2013-02-01

    The synthetic biology matures to promote the heterologous biosynthesis of the well-known drug paclitaxel that is one of the most important and active chemotherapeutic agents for the first-line clinical treatment of cancer. This review focuses on the construction and regulation of the biosynthetic pathway of paclitaxel intermediates in both Escherichia coli and Saccharomyces cerevisiae. In particular, the review also features the early efforts to design and overproduce taxadiene and the bottleneck of scale fermentation for producing the intermediates.

  6. Ex-vivo expansion of hematopoietic progenitor cells: preliminary results in breast cancer.

    PubMed

    McNiece, I; Jones, R; Cagnoni, P; Bearman, S; Nieto, Y; Shpall, E J

    1999-04-01

    Ex-vivo expanded progenitor cells have been proposed as a source of cells to support high-dose chemotherapy and to decrease or eliminate the period of neutropenia following transplantation. To date, no clinical studies using ex vivo expanded cells, have demonstrated any decrease in the time to neutrophil or platelet recovery, although a number of clinical studies have been performed using a variety of growth factor cocktails and culture conditions. Over the past 6 years we have developed a static culture system that results in optimal expansion of myeloid progenitor cells. We have initiated a clinical study to evaluate this culture system in breast cancer patients receiving peripheral blood progenitor cells (PBPC) to support high-dose chemotherapy. CD34 selected cells were cultured for 10 days in 800 ml of defined media (Amgen Inc.) containing 100 ng/ml each of rhSCF, rhG-CSF and rhMGDF in 1L teflon bags (American Fluoroseal) at 20,000 to 50,000 cells per ml. After culture the cells were washed with 3 volumes of PBS to remove all media and growth factors and reinfused on day 0 of transplant followed by daily administration of rhG-CSF. On day +1 the patients received an unexpanded PBPC product to ensure the durability of the graft. Patients transplanted with expanded PBPC cells recovered neutrophil counts (ANC > 500/microl) as early as day 4 post transplant with a median of 6 days (range 4 to 14 days). In comparison, our historical control group of patients (N=175) had a median time to neutrophil engraftment of 9 days (range 7 to 24 days). A second cohort of patients were transplanted with expanded cells alone and a similar rapid engraftment was obtained. The first patients are now over 70 days post transplant with durable engraftment. No effect on platelet recovery has been observed in any patients to date. These data demonstrate that PBPC expanded under the conditions defined can significantly shorten the time to engraftment of neutrophils.

  7. The Massive Progenitor of the Type II-linear Supernova 2009kr

    NASA Astrophysics Data System (ADS)

    Elias-Rosa, Nancy; Van Dyk, Schuyler D.; Li, Weidong; Miller, Adam A.; Silverman, Jeffrey M.; Ganeshalingam, Mohan; Boden, Andrew F.; Kasliwal, Mansi M.; Vinkó, József; Cuillandre, Jean-Charles; Filippenko, Alexei V.; Steele, Thea N.; Bloom, Joshua S.; Griffith, Christopher V.; Kleiser, Io K. W.; Foley, Ryan J.

    2010-05-01

    We present early-time photometric and spectroscopic observations of supernova (SN) 2009kr in NGC 1832. We find that its properties to date support its classification as Type II-linear (SN II-L), a relatively rare subclass of core-collapse supernovae (SNe). We have also identified a candidate for the SN progenitor star through comparison of pre-explosion, archival images taken with WFPC2 on board the Hubble Space Telescope with SN images obtained using adaptive optics plus NIRC2 on the 10 m Keck-II telescope. Although the host galaxy's substantial distance (~26 Mpc) results in large uncertainties in the relative astrometry, we find that if this candidate is indeed the progenitor, it is a highly luminous (M 0 V = -7.8 mag) yellow supergiant with initial mass ~18-24 M sun. This would be the first time that an SN II-L progenitor has been directly identified. Its mass may be a bridge between the upper initial mass limit for the more common Type II-plateau SNe and the inferred initial mass estimate for one Type II-narrow SN. Based in part on observations made with the NASA/ESA Hubble Space Telescope (HST), obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under NASA contract NAS 05-26555; the 6.5 m Magellan Clay Telescope located at Las Campanas Observatory, Chile; various telescopes at Lick Observatory; the 1.3 m PAIRITEL on Mt. Hopkins; the SMARTS Consortium 1.3 m telescope located at Cerro Tololo Inter-American Observatory (CTIO), Chile; the 3.6 m Canada-France-Hawaii Telescope (CFHT), which is operated by the National Research Council of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii; and the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA, with

  8. Marine Engine Mechanics. Performance Objectives. Intermediate Course.

    ERIC Educational Resources Information Center

    Jones, Marion

    Several intermediate performance objectives and corresponding criterion measures are presented for each of ten terminal objectives for a two-semester course (3 hours daily). This 540-hour intermediate course includes advanced troubleshooting techniques on outboard marine engines, inboard-outboard marine engines, inboard marine engines, boat…

  9. Diesel Mechanics. Performance Objectives. Intermediate Course.

    ERIC Educational Resources Information Center

    Tidwell, Joseph

    Several intermediate performance objectives and corresponding criterion measures are listed for each of six terminal objectives for an intermediate diesel mechanics course (two semesters, 3 hours daily) designed for high school students who upon completion would be ready for an on-the-job training experience in diesel service and repair. Through…

  10. Radio and Television Servicing. Intermediate Course.

    ERIC Educational Resources Information Center

    Campbell, Guy; And Others

    Several intermediate performance objectives and corresponding criterion measures are listed for each of 32 terminal objectives for an intermediate (second year) radio/TV servicing course. This 1-year course (3 hours daily) was designed to provide the student with the basic skills and knowledges necessary for entry level employment in the Radio/TV…

  11. Business Machine Maintenance. Performance Objectives. Intermediate Course.

    ERIC Educational Resources Information Center

    McMinn, Robert

    Several intermediate performance objectives and corresponding criterion measures are listed for each of 28 terminal objectives presented in this guide for an intermediate business machine maintenance course at the secondary level. (For the basic course guide see CE 010 949.) Titles of the 28 terminal objective sections are Career Opportunities,…

  12. Gasoline Engine Mechanics. Performance Objectives. Intermediate Course.

    ERIC Educational Resources Information Center

    Jones, Marion

    Several intermediate performance objectives and corresponding criterion measures are listed for each of six terminal objectives presented in this curriculum guide for an intermediate gasoline engine mechanics course at the secondary level. (For the beginning course guide see CE 010 947.) The materials were developed for a two-semester (2 hour…

  13. Automotive Body Repair. Performance Objectives. Intermediate Course.

    ERIC Educational Resources Information Center

    Lang, Thomas

    Several intermediate performance objectives and corresponding criterion measures are listed for each of 10 terminal objectives for an intermediate automotive body repair and refinishing course. The materials were developed for a two-semester (3 hours daily) course for specialized classrooms, shop, and practical experiences designed to enable the…

  14. Appliance Services. Intermediate Course. Career Education.

    ERIC Educational Resources Information Center

    Killough, Joseph

    Several intermediate performance objectives and corresponding criterion measures are listed for each of 16 terminal objectives for an intermediate appliance repair course. The materials were developed for a 36-week course (3 hours daily) covering the areas of refrigeration, maintenance, repair, and troubleshooting of refrigerators and air…

  15. Air Conditioning. Performance Objectives. Intermediate Course.

    ERIC Educational Resources Information Center

    Long, William

    Several intermediate performance objectives and corresponding criterion measures are listed for each of seven terminal objectives for an intermediate air conditioning course. The titles of the seven terminal objectives are Refrigeration Cycle, Job Requirement Skills, Air Conditioning, Trouble Shooting, Performance Test, Shop Management, and S.I.E.…

  16. 19 CFR 122.84 - Intermediate airport.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Intermediate airport. 122.84 Section 122.84... Intermediate airport. (a) Application. The provisions of this section apply at any U.S. airport to which an... aircraft arrives at the next airport, the aircraft commander or agent shall make entry by filing the: (1...

  17. 19 CFR 122.84 - Intermediate airport.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Intermediate airport. 122.84 Section 122.84... Intermediate airport. (a) Application. The provisions of this section apply at any U.S. airport to which an... aircraft arrives at the next airport, the aircraft commander or agent shall make entry by filing the: (1...

  18. 19 CFR 122.84 - Intermediate airport.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Intermediate airport. 122.84 Section 122.84... Intermediate airport. (a) Application. The provisions of this section apply at any U.S. airport to which an... aircraft arrives at the next airport, the aircraft commander or agent shall make entry by filing the: (1...

  19. 19 CFR 122.84 - Intermediate airport.